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CLAIM OF PRIORITY [0001] This application claims priority to provisional U.S. Patent Application No. 61/254,473, filed Oct. 23, 2009, which is incorporated by reference in its entirety. TECHNICAL FIELD [0002] This invention relates to biotemplated inorganic materials. BACKGROUND [0003] Hydrogen is a useful energy source in fuel cells and batteries. Because it is difficult to obtain hydrogen from a gas source, it can be desirable to obtain it from a liquid source. Liquid fuels can also provide higher energy densities than gaseous fuels. A catalyst may be used to obtain hydrogen from a liquid source such as ethanol. Catalysts should be relatively inexpensive, highly active and stable. Efficiency and stability of catalysts are affected by surface area, physical isolation and fixation of metals, the presence of active materials near the surface of the 3-D structure, and sintering stability, among other factors. SUMMARY [0004] Metal oxides represent a very large class of materials useful in a variety of applications including electronics, optics, ceramics, and catalysts. Many applications that are dependent upon the surface area of the material or size of the crystallite domain can be further enhanced through the use of the nanoparticle form of metal oxides. As such, metal oxide nanoparticles have garnered much research interest over the past few decades, both in novel applications and new synthesis methods. [0005] In general, size control is desirable in nanoparticle synthesis, and small, monodisperse nanoparticles can be especially useful. Reaction conditions are preferably safe and environmentally friendly (e.g., limiting the quantity of organic solvents and hazard reagents), use readily available and inexpensive starting materials, and can prepare a variety of materials under similar reaction conditions. [0006] The efficiency of catalytic materials is influenced by both the chemical nature of the material, and its physical form. For example, in heterogeneous catalysis (e.g., where a solid phase catalysis is exposed to gas and/or liquid phase reactants), a high specific surface can be preferred. Thermal stability is desirable as well. [0007] In one aspect, a catalytic material suitable for high-temperature heterogeneous catalysis includes nanoporous metal oxide nanoparticles. The nanoporous metal oxide nanoparticles can include a nanostructure. The nanostructure can further include a transition metal. [0008] The metal oxide can include a manganese oxide, a magnesium oxide, an aluminum oxide, a silicon oxide, a zinc oxide, a copper oxide, a nickel oxide, a cobalt oxide, an iron oxide, a titanium oxide, yttrium oxide, a zirconium oxide, a niobium oxide, a ruthenium oxide, a rhodium oxide, a palladium oxide, a silver oxide, an indium oxide, a tin oxide, an lanthanum oxide, an iridium oxide, a platinum oxide, a gold oxide, a cerium oxide, a neodymium oxide, a praseodymium oxide, an erbium oxide, a dysprosium oxide, a terbium oxide, a samarium oxide, a lutetium oxide, a gadolinium oxide, a ytterbium oxide, a europium oxide, a holmium oxide, a scandium oxide, or a combination thereof. In one embodiment, the nanoporous metal oxide nanoparticles include ceria. [0009] A measured X-ray diffraction pattern of the nanoporous metal oxide nanoparticles can be substantially unchanged after 60 hours at 400° C. The nanoporous metal oxide nanoparticles can have a BET surface area of greater than 150 m 2 /g. The nanoporous metal oxide nanoparticles can be substantially free of pores having a width greater than 20 nm. [0010] In another aspect, a method of producing a metal oxide nanoparticle includes contacting an aqueous solution of a metal salt with an oxidant. The oxidant can include hydrogen peroxide. The aqueous solution can include two or more different metal salts. The method can include selecting nanoparticle-forming conditions to form nanoparticles having a predetermined size. The predetermined size can be in the range of 0.5 nm to 250 nm, for example, in the range of 1 nm to 100 nm. [0011] The method can include forming a nanoparticle including a mixed metal oxide having the formula M 1 x M 2 (1-x) O y , wherein M 1 is a first metal, M 2 is a second metal, x represents the mole fraction of M 1 of total metal in the metal oxide, and y is such that the bulk metal oxide is charge-neutral. The mixed metal oxide can include oxygen vacancies. [0012] The aqueous solution can include a virus particle having an affinity for an oxide of the metal in the aqueous solution. The virus particle can be an M13 bacteriophage. [0013] In another aspect, a method of making supported catalytic material includes contacting a ceramic support with a virus particle to form a supported virus conjugate, the virus particle having a first surface moiety having affinity for the ceramic support and a second surface moiety having an affinity for a catalytic material; and forming a plurality of catalyst nanoparticles at the surface of the virus particle. [0014] The ceramic support can include silica, α-alumina, β-alumina, γ-alumina, rutile titania, austentite titania, ceria, zirconia, manganese oxide, manganese phosphate, manganese carbonate, zinc oxide, or a combination thereof. Forming the plurality of catalyst nanoparticles can include contacting the supported virus conjugate an aqueous solution of a metal salt with an oxidant. The oxidant can include hydrogen peroxide. The aqueous solution can include two or more different metal salts. [0015] The method can include selecting nanoparticle-forming conditions to form nanoparticles having a predetermined size. The predetermined size is in the range of 0.5 nm to 250 nm, for example, in the range of 1 nm to 100 nm. [0016] The method can include forming a nanoparticle including a mixed metal oxide having the formula M 1 x M 2 (1-x) O y , wherein M 1 is a first metal, M 2 is a second metal, x represents the mole fraction of M 1 of total metal in the metal oxide, and y is such that the bulk metal oxide is charge-neutral. The mixed metal oxide can include oxygen vacancies. [0017] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a schematic depiction of a viral-templated catalyst. [0019] FIG. 2A is a TEM image of CeO 2 nanoparticles produced in the absence of phage particles. [0020] FIG. 2B is a TEM image of a CeO 2 nanoparticles produced in the presence of phage particles. [0021] FIG. 3 is a graph illustrating the coarsening behavior at 500° C. of nanoparticles compared to nanowires templated with phage. [0022] FIGS. 4A-B are graphs illustrating the pore size distribution of CeO 2 nanoparticles prepared under different conditions. [0023] FIG. 5 is an XRD measurement of 5% Ni-1% Rh on CeO 2 nanowires after 60 hours of heat treatment at 400° C. [0024] FIG. 6 is a schematic depiction of a test reactor to monitor catalysis. [0025] FIGS. 7A-7B are graphs depicting the composition of gases produced in a catalytic reactor under varying conditions. [0026] FIG. 8 is a schematic depiction of a virus-templated, supported material. [0027] FIGS. 9A-9C are graphs depicting product output of different catalyst systems over time. FIGS. 9D-9E are X-ray diffraction patterns of different catalyst systems after use. DETAILED DESCRIPTION [0028] Catalysts for producing hydrogen, such as transition metal and/or noble metal catalysts, can be prepared by a number of methods. Frequently, the catalyst materials include catalyst particles (e.g., transition metal and/or noble metal particles) and a support. Flame hydrolysis involves hydrolyzing a metal chloride precursor, such as silicon tetrachloride, in a hydrogen/oxygen flame. The hydrogen burns and reacts with oxygen, producing very finely dispersed water molecules in the vapor phase, which then react with the metal chloride to form the corresponding metal oxide nanoparticle and hydrochloric acid. This method is often limited by the availability of a precursor which decomposes upon contact with water. [0029] Another method of catalysis preparation is aerogel synthesis. An aerogel is formed when a liquid solvent in a solid-liquid mixture becomes supercritical and then changes phase to a vapor, exchanging with the environment without any rapid volume changes which might damage the microstructure of the catalyst support. The remaining solid maintains a high level of network connectivity without collapsing and is desirable for its high surface area and porosity. [0030] A mesoporous material may be more interesting as a catalyst than a solid material. Organic functionalization during particle formation can produce the desired pore distribution. The initial particles are formed with organic molecules such as tetraethoxysilane (TEOS) embedded into the structure at room temperature. Subsequent heat treatments drive off the organic molecules, leaving a solid with pores in it defined by the missing organic molecules. A micelle can also be used in this method of catalyst preparation. [0031] Colloidal syntheses are broadly described as syntheses wherein a solid is precipitated from a solvent-soluble precursor into a solvent-insoluble solid nanoparticle mixture. Metallic clusters are formed by reducing metal ions in solution with an agent such as hydrogen or sodium borohydride. The reduced metal ions become zero-valent, losing their electrostatic repulsion, and are able to nucleate nanoparticles of the neutral metallic material. Colloidal syntheses are related to other methods such as the usage of microemulsions, metal complex decomposition, gas phase synthesis, high-gravity reactive precipitation and electrochemical synthesis. [0032] Microwave-assisted synthesis depends on the ability of the material to change local charge configuration and lose energy when this happens. This sort of synthesis can include the production of nanolayer carbide and nitrides on the surface of metal catalysts or the fluidization of metal along with carbon black in argon. [0033] A catalyst can also be synthesized by dendrimer-metal precursor methods. A dendrimer can perform as a nanoreactor, allowing the polymer to grow in a tree-like fashion. The steric hindrance of adjacent chains eventually cause the dendrimer to fold back on itself into a single molecule, where the inside of the dendrimer sphere can be made to attract metal ions in solution. Reduction of the metal-dendrimer complex causes the complex to collapse, forming a nanoparticle inside the dendrimer. The entire dendrimer-metal nanocomposite is deposited onto a porous support and the dendrimer is then removed by either heat treatment of chemical means. [0034] The catalyst particle distribution on a support has significant impact on the final properties of the catalyst. Incipient wetness impregnation or dry impregnation can be used to control the catalyst distribution. Adding an amount of solvent very close to the total pore volume of the support allows all of the solvent to be rapidly taken up into the support. Soaking in the precursor that is dissolved in the same solvent results in a diffusion-limited spread of catalyst material into the support, which causes the catalyst particles to be primarily located at the surface of the support. Drying is also a major influence in the catalyst particle distribution, wherein a constant drying rate results in most of the dissolved precursor forming catalyst species on the external surface of the support. In a second stage called the “first falling-rate period” the rate of drying steadily decreases in a roughly linear fashion, resulting in the dissolved catalyst depositing internal to the support. The “second falling-rate period” where the drying rate falls more gradually until the moisture content is eventually zero, the catalyst particles are deposited at the center of the support. [0035] Ceria (CeO 2 ) is a ceramic with excellent redox properties, and is a common catalyst support used in a variety of reactions. In particular, ceria supported noble metals promote the production of hydrogen from ethanol. Specifically, this reaction is given by [0000] C 2 H 5 OH+2H 2 O+½O 2 →2CO 2 +5H 2 [0000] See, for example, G. A. Deluga, J. R. Salge, L. D. S. Science 2004, 303, 993, which is incorporated by reference in its entirety. [0036] The activity of CeO 2 in assisting catalysis is heavily dependent upon the type, size and distribution of oxygen vacancies in the CeO 2 fluorite crystal structure. The vacancies can help in the efficiency for reversible oxygen release, which can allow for the formation of more stable states of catalytically active metals adsorbed to the surface. See, for example, F. Esch, S. Fabris, L. Z. Science 2005, 309, 752; and A. Trovarelli, Ed.; Catalysis by Ceria and Related Materials ; Imperial College Press: 2002, each of which is incorporated by reference in its entirety. Much work has been focused on what material is used in conjunction with CeO 2 in an effort to eliminate CO and acetaldehyde byproducts, increase efficiency, and decrease operating temperature of the reaction in addition to improving the properties of the CeO 2 co-catalyst to enhance catalysis and simplify synthesis. See, for example, J. Kugai, V. Subramani, C. S. Journal of Catalysis 2006, 238, 430-440; S. Deshpande, S. Patil, S. K. Applied Physics Letters 2005, 87, 133113; F. Zhang, P. Wang, J. K. Surface Science 2004, 563, 74-82; J. R. Salge, G. A. Deluga, L. D. S. Journal of Catalysis 2005, 235, 69-78; C. Zerva, C. J. P. Applied Catalysis B: Environmental 2006, 67, 105-112; H. Idriss, Platinum Metals Rev 2004, 48, 105-115; P.-Y. Sheng, A. Yee, G. A. B. Journal of Catalysis 2002, 208, 393-403; S. J. Morrison, P. Y. Sheng, A. Y. Prepr. Pap .- Am. Chem. Soc., Div. Petr. Chem. 2006, 51, 26; J. Kugai, S. Velu, C. S. Catalysis Letters 2005, 101, 255; M. Fuchs, B. Jenewein, S. P. Applied Catalysis A: General 2005, 294, 279-289; Y. Hirta, A. Harada, X. W. Ceramics International 2005, 31, 1007-1013; P. Dutta, S. Pal, M. S. S. American Chemical Society 2006; M. Romeo, K. Bak, J. E. F. Surface and Interface Analysis 1992, 20, 508-512; D. R. Mullins, S. H. Overbury, D. R. H. Surface Science 1998, 409, 307-319; T. Masui, K. Fujiware, K. M. Chem. Mater. 1997, 9, 2197-2204; M. Hirano, E. K. J. Am. Ceram. Soc. 1996, 79, 777-780; X. Yu, F. Li, X. Y. J. Am. Ceram. Soc. 1999, 83, 964; P. Chen, I. C. J. Am. Ceram. Soc. 1992, 76, 1577-1583; T. Sato, T. Katakura, S. Y. Solid State Ionics 2004, 172, 377-382; A. S. Bodke, S. S. Bharadwaj, L. D. S. Journal of Catalysis 1998, 179, 138-149; and M. Yamashita, S. Yoshida, Y. F. Journal of Materials Science 2001, 37, 683-687, each of which is incorporated by reference in its entirety. [0037] A bimetallic Ni—Rh/CeO 2 catalyst can produce less CO and cost less than a similar Rh/CeO 2 catalyst. Nickel is a less expensive metal and has a d-orbital very similar in shape to that of rhodium. Therefore, it can facilitate similar reactions, while producing less acetaldehyde than Pt, Pd, Ru or Au. See, for example, J. Kugai, V. Subramani, C. S. Journal of Catalysis 2006, 238, 430-440; and J. Kugai, S. Velu, C. S. Catalysis Letters 2005, 101, 255, each of which is incorporated by reference in its entirety. Kugai found that for reactions taking place around 375° C., nickel itself only achieved 40% conversion of ethanol while 10% Ni and 1% Rh achieved over 92% conversion. Rhodium can improve catalyst performance. See, for example, J. Kugai, V. Subramani, C. S. Journal of Catalysis 2006, 238, 430-440; and J. Kugai, S. Velu, C. S. Catalysis Letters 2005, 101, 255, each of which is incorporated by reference in its entirety. [0038] Synthesis for CeO 2 nanocrystals can by accomplished in a variety of ways, such as solid-state reactions, hydrothermal syntheses, homogenous precipitation or two-phase syntheses. See, for example, T. Masui, K. Fujiware, K. M. Chem. Mater. 1997, 9, 2197-2204; M. Hirano, E. K. J. Am. Ceram. Soc. 1996, 79, 777-780; X. Yu, F. Li, X. Y. J. Am. Ceram. Soc. 1999, 83, 964; P. Chen, I. C. J. Am. Ceram. Soc. 1992, 76, 1577-1583; T. Sato, T. Katakura, S. Y. Solid State Ionics 2004, 172, 377-382; and M. Yamashita, S. Yoshida, Y. F. Journal of Materials Science 2001, 37, 683-687, each of which is incorporated by reference in its entirety. The most common commercial method of CeO 2 nanocrystal synthesis is wet impregnation, where an existing CeO 2 foam is impregnated with rhodium precursors and calcined to produce nanoparticles attached to the CeO 2 surface. Another method of nanoparticle synthesis is a biocompatible synthesis based on homogeneous precipitation. See, for example, T. Sato, T. Katakura, S. Y. Solid State Ionics 2004, 172, 377-382; and M. Yamashita, S. Yoshida, Y. F. Journal of Materials Science 2001, 37, 683-687, each of which is incorporated by reference in its entirety. [0039] A wide variety of metal oxide nanoparticles can be synthesized from aqueous solution using hydrogen peroxide as an etchant to prevent particle growth during hydrolysis under basic conditions. The starting materials can include a metal salt, e.g., a metal chloride or metal nitrate. Increased amounts of hydrogen peroxide can decrease particle size. In many cases, the metal oxide was formed immediately with a nanocrystallite size ranging from 1 nm to several tens of nanometers. After synthesis, the particles were dried and heat treated to investigate phase changes and particle growth after calcination. [0040] The reaction produces high quality nanoparticles using hydrogen peroxide concentrations higher than reported in M. Yamashita, S. Yoshida, Y. F. Journal of Materials Science 2001, 37, 683-687, which is incorporated by reference in its entirety. For example, the mole ratio of H 2 O 2 to metal can be, for example, in the range of 0.001 to 100, in the range of 0.01 to 10, or in the range of 0.1 to 10. [0041] A mixed metal oxide can have the formula M 1 i M 2 j O x . M 1 and M 2 can each independently be a metal, or in some cases, a semi-metal such as silicon. For example, M 1 and M 2 can each independently be magnesium, aluminum, silicon, scandium, titanium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, ruthenium, rhodium, palladium, silver, indium, tin, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, ytterbium, lutetium, iridium, platinum, gold, or another metal. [0042] In general, the values of i, j, and x are non-negative. In some instances, the value of i, j, or x can be an integer. In some cases, the sum of i and j can be an integer, and the sum of x and y can be an integer. For example, a mixed metal oxide can have the formula M 1 i M 2 i-1 O. In this formula, the sum of i and j is 1, and the value of x is 1. [0043] The metal oxide can include, but is not limited to, a manganese oxide (e.g., MnO x ), a magnesium oxide (e.g., MgO), an aluminum oxide (e.g., Al 2 O 3 ), a silicon oxide (e.g., SiO x ), a zinc oxide (e.g., ZnO), a copper oxide (e.g., CuO or Cu/CuO), a nickel oxide (e.g., NiO or Ni/NiO), a cobalt oxide (e.g., CO 3 O 4 or Co/Co 3 O 4 ), an iron oxide (e.g., Fe 2 O 3 as hematite or maghemite, or Fe 3 O 4 as magnetite), a titanium oxide, yttrium oxide, a zirconium oxide, a niobium oxide, a ruthenium oxide, a rhodium oxide, a palladium oxide, a silver oxide, an indium oxide, a tin oxide, an lanthanum oxide, an iridium oxide, a platinum oxide, a gold oxide, a cerium oxide, a neodymium oxide, a praseodymium oxide, an erbium oxide, a dysprosium oxide, a terbium oxide, a samarium oxide, a lutetium oxide, a gadolinium oxide, a ytterbium oxide, a europium oxide, a holmium oxide, a scandium oxide, or a combination thereof. [0044] The nanostructure of the Ni—Rh/CeO 2 system can have a substantial effect on the final product quality. Preferably, the nanostructure of the catalyst has rhodium atoms (e.g., a majority of all rhodium atoms) near a CeO 2 oxygen vacancy, rhodium atoms at the surface of the structure (and therefore accessible to reactants), a high surface area/volume ratio; and rhodium atoms physically isolated from other rhodium atoms. These structural features can enhance the specific activity of the catalyst. See, for example, J. R. Salge, G. A. Deluga, L. D. S. Journal of Catalysis 2005, 235, 69-78, which is incorporated by reference in its entirety. [0045] M13 bacteriophage can serve as a template for nanoparticle growth. See, for example, Ki Tae Nam, Dong-Wan Kim, P. J. Y. Science 2006, 312, 885, which is incorporated by reference in its entirety. Protein engineering techniques (e.g., phage display) can produce a virus that has a protein coat with binding affinity for a desired target material, e.g., an inorganic material such as a metal or a metal oxide. The protein coat protein can have a metal binding motif, which, for example, can be a negatively charged motif, e.g., tetraglutamate or a peptide with a binding affinity to a metal. For example, the motif can be a 12-amino acid peptide with a high affinity for Au. In one example, engineered M13 virus particles allowed control of the assembly of nanowires of CO 3 O 4 with a small percentage of Au dopant. Id. [0046] While M13 bacteriophage can have a major coat protein with a motif that binds specific metals, the motif can also block binding of other metals. For example, tetraglutamate can interact with various metal ions but blocks interaction with Au due to electrostatic repulsion. See, for example, Ki Tae Nam, Dong-Wan Kim, P. J. Y. Science 2006, 312, 885, which is incorporated by reference in its entirety. M13 bacteriophage with a major coat protein specific to CeO 2 and a small percentage of peptides specific for rhodium alone can serve as a template for CeO 2 nanowire can be created with a spatially interspersed rhodium nanocrystals. FIG. 1 depicts a nanostructure exhibiting desirable properties. The virus with randomly expressed proteins capable of nucleating either CeO 2 or rhodium metal are grown first, and then subsequently exposed to precursors of CeO 2 and rhodium to produce a protein templated catalyst. [0047] The nanostructured system increases the fraction of rhodium atoms that are touching a Ce atom, increasing the probability that a rhodium-CeO 2 vacancy will occur and reducing the amount of inactive rhodium. They can reduce the amount of rhodium that is required for the system, thereby decreasing cost. Next, the M13 bacteriophage acts as a scaffold with a thin layer (e.g., a monolayer) of nanocrystals at the surface, allowing the majority of rhodium atoms to be near the surface and a very small amount of rhodium atoms to be trapped. This can further reduce the amount of rhodium needed for the system since the inactive rhodium is decreased. Third, the resultant nanorod can have a high surface area to volume ratio. The final pore size distribution may also have a substantial impact on the final product distribution and catalyst activity. Finally, the random locations of the metal-binding motifs on the M13 viral coat can favor physical separation of adjacent rhodium nanocrystals compared to that given by wet impregnation or co-precipitation. When physically separated, rhodium nanocrystals are unlikely to sinter together due to hotspots during catalysis. The physical separation can be enhanced by the 1-D nature of a nanowire. [0048] In general, smaller ceria nanoparticles can be preferable, due to their high surface area to volume ratio and oxygen vacancy concentration. The oxygen vacancy concentration coupled with the inherently high oxygen diffusion rate in the fluorite structure of ceria creates an excellent surface for absorbing and releasing oxygen as needed to support redox catalysts. See J. Kugai, V. Subramani, C. S. Journal of Catalysis 2006, 238, 430-440; S. Deshpande, S. Patil, S. K. Applied Physics Letters 2005, 87, 133113; F. Zhang, P. Wang, J. K. Surface Science 2004, 563, 74-82. C. Zerva, C. J. P. Applied Catalysis B: Environmental 2006, 67, 105-112; F. Esch, S. Fabris, L. Z. Science 2005, 309, 752; A. Trovarelli, Ed.; Catalysis by Ceria and Related Materials ; Imperial College Press: 2002; Q. Fu, H. Saltsburg, M. F.-S. Science 2003, 301, 935; and Z. Liu, S. Jenkins, D. K. Physical Review Letters 2005, 94, 196102, each of which is incorporated by reference in its entirety. Smaller particles can have a higher activation energy to sintering which explains why it appears to have a large temperature response, suggesting that for different operating temperatures, different initial sized nanoparticles can provide a high long-term stability. Forming the nanowires with a thin coat can limit the sintering to occur in two dimensions. This can result in resistance to particle coarsening, which in most systems, can cause a gradual degradation of the catalyst. [0049] M13 bacteriophage can be engineered to bind to different materials at different sites, by introducing different affinity motifs in the major and minor coat proteins. FIG. 8 illustrates a composite material 10 include a ceramic support 20 . Bacteriophage particles 30 are bound to the surface of support 20 by coat proteins 40 selected to have affinity for ceramic material of support 20 . Catalytic metal oxide nanoparticles 50 are bound to virus particles 30 by coat proteins selected to have affinity for the metal oxide. Composite material 10 provides a large quantity (e.g., a high surface area) of catalytic metal oxide nanoparticles 50 . Because the nanoparticles are bound to support 20 , the composite material can be handled more conveniently, for example in preparing a catalytic reactor. Example 1 [0050] Previously, an E4 strain of M13 phage that expresses four glutamic acids (EEEE) on the surface of the major coat was developed. See, for example, Ki Tae Nam, Dong-Wan Kim, P. J. Y. Science 2006, 312, 885, which is incorporated by reference in its entirety. The E4 strain typically mutates to an E3 strain which includes AEEE instead of EEEE after a few amplications. To form CeO 2 nanowires on an E3 phage, the E3 phage with a metal-binding motif on a coat protein is amplified to a concentration of ˜10 14 mL −1 . 500 μL of CeCl 3 was incubated for 10 minutes with 100 μL of the E3 phage with between 10 5 and 10 12 total phage particles added from the amplified solution. 50 μL of NaOH simultaneously with 1 μL 0.3 wt % H 2 O 2 was added to the mixture and immediately vortexed. The resultant nanowires were put on a TEM grid for imaging. FIG. 2A shows a TEM image of the system with no virus. FIG. 2B shows a TEM image of CeO 2 nanowires produced with 10 12 phage particles in solution. In several places, the phage can be identified by the thin hollow while line (indicated by arrows) showing the core of the phage where no CeO 2 is present. [0051] The addition of phage to the CeO 2 synthesis resulted in highly enhanced thermal stability wherein the nanowires of CeO 2 have essentially identical nanocrystallinity before and after 60 hours of heat treatment at 400° C. FIG. 3 shows the difference in coarsening behavior, as measured by X-ray diffraction, at 500° C. sintering conditions between nanoparticles and nanowires templated with phage as a function of phage concentration. The addition of phage also suppresses growth from the 8 th order behavior seen in nanoparticles alone to growth orders higher than 20 in 500° C. sintering conditions. Example 2 [0052] Rh—Ni/CeO 2 nanoparticles were formed by co-precipitating RhCl 3 , NiCl 2 and CeCl 3 using NaOH and H 2 O 2 as pH modifier and oxidizer, respectively, to form Rh 2 O 3 , NiO and CeO 2 , which are the catalytically active phases of each material. A solution containing 1% RhCl 3 , 5% NiCl 2 and 94% CeCl 3 (percent of total metal ions) was made and precipitated by adding NaOH and H 2 O 2 in the same way as was done for the CeO 2 nanoparticles in Example 1, at a 10×H 2 O 2 concentration (i.e., 10-fold more concentrated than reported in Yamashita and Yoshita). The solution was dried in the air and then heat treated at 200° C. Nanoparticles of Rh 2 O 3 were formed after heat treatment at 400° C. The nanoparticles were approximately 4.0 nm and were black. Similarly, nanoparticles of NiO were formed after heat treatment at 400° C. The nanoparticles were approximately 9.6 nm and went from a bluish-green powder to a dark black after heat treatment. [0053] To verify that the ratio of metal atoms in the final particles was roughly the same as the ratio of the precursor mixture, TEM images of a final dried nanoparticle sample made with 5% RhCl 3 and 95% CeCl 3 were recorded. Energy dispersive spectroscopy showed that 88% Ce, 5% Rh, and 7% Cl, which is approximately in line with the input precursors. The nanoparticle powder had an average crystalline diameter of about 3.0 nm as measured by X-ray diffraction, and a BET surface area of 152 m 2 /g with a pore volume of 0.113 cm 3 /g. [0054] Nanowires were then formed by simple co-precipitation by using a solution with 1% RhCl 3 , 5% NiCl 2 and 94% CeCl 3 . E3 phage was added to get an concentration of 10 11 phage particles per mL with 100 mM total concentration of metal salt precursors. The resulting nanowire powder had an average crystallite size of 3.5 nm, and a BET surface area of 180 m 2 /g with a pore volume of 0.121 cm 3 /g. FIG. 4A shows the pore distribution calculated using a density functional theory model of the CeO 2 nanoparticles formed in the absence of virus particles. FIG. 4B show the pore distribution the CeO 2 nanowires formed by co-precipitation with E3. The nanowire powder had an average crystalline size of 3.5 nm, and a BET surface area of 180 m 2 /g with a pore volume of 0.121 cm 3 /g. The nanoparticles have less total area contained in the pores while the nanowires also have a narrower pore size. [0055] FIG. 5 shows that after the nanowire powder was heat treated at 400° C. for 60 hours, the average change in nanocrystal size was less than 0.3 nm and no precipitation of minor phases was observed. In the nanoparticle sample, however, there was precipitation. This suggests good integration of rhodium and nickel into the nanowire structure, as opposed to discrete clusters of rhodium and nickel separate from the nanowires. [0056] The nanowires and nanoparticles were then tested for catalytic activity in converting ethanol to hydrogen and CO 2 . FIG. 6 shows a schematic overview of the test reactor. After the system was calibrated with water, ethanol, and different gases, air was flowed through the FTIR system 10 without ethanol or water being injected into the manifold 7 at each temperature. Then, the liquid water tank 2 with flow controller 4 and liquid ethanol tank 3 with flow controller 5 allowed water and ethanol, respectively to be heated in heating manifold 7 . Gas calibrations were also done with gas flow controller 6 . All tubing 9 is 316 stainless steel and in most places wrapped with heat rope and layers of insulation to prevent condensation of water inside the tubing. The catalyst powders were heated from the outside by use of tube furnace 8 . The powders were held on a filter in tube furnace 8 . A set of dual miniature solenoid valves 11 were allowed to sample the output stream after passing though the FTIR. Hydrogen sensor 12 is attached to a computer for measurements. Finally, CO 2 , CH 4 , CO, CH 3 COH and H 2 concentrations were calculated and normalized so that they sum 100% to account for fluctuations in water concentrations. [0057] FIGS. 7A and 7B provide a comparison of gas output composition as a function of temperature for co-precipitated nanoparticles ( FIG. 7A ) and for nanowires templated on E3 ( FIG. 7B ). Total flow rate was 10.882 mmol/min, and the amount of catalyst in both cases was 500 mg (˜2.905 mmol assuming CeO 2 ), for a GHSV of 32.7 hr −1 . Example 3 [0058] Ni—Rh@CeO2 was formed by using the oxidation and hydrolysis of CeCl 3 with RhCl 3 and NiCl 2 in aqueous solution. Water (120 mL) was either used as-is or by diluting E3M13 phage (AEEE expressed on the pVIII major coat protein) to a concentration of approximately 10 12 /mL by adding ˜10-100 μL of phage solution at a spectroscopically measured approximate concentration of ˜10 15 /mL. The diluted phage or phage-free water was mixed for 30 min in a 500 mL Ehrlenmyer flask at room temperature to ensure good dispersion. For comparison of different phage concentrations, the concentrated phage was decreased in concentration serially by factors of 10 to achieve an internally accurate phage ratio. [0059] After mixing, 30 mL of 1 M metal chloride solution containing RhCl 3 (anhydrous, 99.9% Alfa Aesar), NiCl 2 (anhydrous, 98% Alfa Aesar), and CeCl 3 (heptahydrate, 99% Acros Organics) in a 1:10:89 molar ratio (RhCl 3 /NiCl 2 /CeCl 3 ) was added to either diluted M13 phage or phage-free water and allowed to equilibrate over 30 min at room temperature at 650 rpm. [0060] After equilibration, nanoparticles were nucleated by the rapid addition of a mixture of 30 mL of 3 M NaOH (99%, Mallinckrodt Chemicals) and 60 μL of 30 wt % H 2 O 2 (29.0-32.0% Reagent ACS, VWR). Immediately after addition, the solution turned dark brown-red and solids formed with gas evolution. The solution was stirred at 650 rpm for 30 min to allow the reaction to go to completion. After completion, the suspension was precipitated using centrifugation and the supernatant discarded. The precipitate was redissolved in water to wash residual NaCl and NaOH from the powder and recentrifuged for a total of three washings. After washing, the precipitate was set out at room temperature in a Petri dish in air until dry. After drying, the powders were finely ground and heat treated at 400° C. for 2 h until the final powder was produced. TGA on similar samples show that 350° C. was a sufficiently high temperature to remove nearly all of the carbon from the sample. [0000] Catalyst powders were loaded in an unpacked layer in a 316 stainless steel chamber (Swagelok Part SS-4F-05 In-Line Particulate Filter) where the filter element was replaced with a 12 mm fine porosity fritted borosilicate disk (ChemGlass Part CG-201-05) to a typical depth of ˜5 mm in the case of 1000 mg samples. In the case of very small samples (100 mg), a thin layer was placed on the borosilicate disk by gently tapping the catalyst chamber until the disk was no longer visible. The disk was replaced after each test, and the gashourly space velocity (GHSV) was changed by using varying amounts of catalyst powder while keeping the absolute flow rate constant to eliminate variations due to reactor activity or pressure changes due to increased flow rate. The GHSV was estimated by using an assumed catalyst density of 1 g/mL, and the gas volume was converted to a standard volume at 298 K and 1 atm. [0061] The entire catalyst chamber was heated to the desired reaction temperature using a tube furnace (HTF55122A 1-Zone 1200° C. furnace with CC58114COMA-1 Digital Controller, Thermo Fisher Scientific). The preheating chamber was made out of 1 in. diameter 316 stainless steel tubing with custom machined Swagelok fittings to allow for the fuel injector (16 lb/h disc high-Z fuel injector, Racetronix Model 621040) to inject liquid directly into the preheating chamber. The fuel injector temperature was measured using a thermocouple on the Swagelok fitting and heated with heat tape (McMASTER-CARR Part 4550T12) wrapped around the preheating chamber outside of the furnace controlled using a temperature controller (Omega CNI3233-C24) to 120° C. [0062] The air mass flow controller in all experiments was set at 14 mL/min (2.94 mL/min O 2 ), argon flow controller was set at approximately 100 mL/min, and ethanol was injected with the fuel injector using a 1.157 ms pulse every 2 s at 50 psi and 24 VDC. This pulse length was equivalent to 2.91 μL per pulse based on fuel injector calibrations done by injecting known pulse lengths and counting the number of pulses required to inject 10 mL of liquid. The total molar ratio at STP for these amounts is 1.7:1:10:11 (air/EtOH/water/argon) with a total flow rate of roughly 200 mL/min. [0063] The internal temperature of the preheating chamber was monitored using a temperature probe placed just above the catalyst bed with a temperature controller (Omega CNI3233-C24), and the temperature of the input gas was typically close to the temperature of the furnace. The preheating chamber had two ⅛ in. Swagelok fittings to allow for argon and air to be added to the mixture using a mass flow controller (Alicat MC-1 SLPM-D/5 M 0-1 SLPM) for the air and a manual flow controller for the argon backflow gas. [0064] Below the reactor bed, the gas mixture was allowed to equilibrate in a 150 mL double-ended 316 stainless steel sample cylinder (Swagelok Part 316 L-50DF4-150) placed inside the furnace to prevent condensation. This volume represents a time to equilibration of roughly 7.5 min assuming approximately 10 times the replacement time to fully equilibrate at a new composition. The output gas was carried through a 0.5 μm 316 stainless steel filter (Swagelok Part SS-4FWS-05) to the GC via ⅛ in. 316 stainless steel tubing sheathed in ¼ in. copper tubing wrapped with high-temperature heat rope (McMASTERCARR Part 3641K26) and using a temperature controller (Omega CNI3233-C24) set to 120° C. to prevent condensation. The tubing entered the GC through a valve with a 250 μL sample loop held at 150° C. after passing through another 0.5 μm 316 stainless steel filter (Swagelok Part SS-2F-05) to prevent clogs in the GC valves. The equilibrated composition was fed continuously through an Agilent 7890A gas chromatograph, where the sample loop was switched onto the column every 35 min. [0065] The sample was measured by the GC initially configured to Agilent Configuration 7890-0047, which meets ASTM D3612 A specifications, with modified inlet temperature to avoid water condensation (150° C.) and lengthened total run time to avoid overlap with any present higher molecular weight hydrocarbons. This configuration uses an argon background with a flame ionization detector (FID) and a nickel methanizing catalyst for the detection of hydrocarbons, CO 2 , and CO, and a thermal conductivity detector (TCD) for the detection of H 2 , O 2 , N 2 , and H 2 O. [0066] The results were calibrated using custom mixed gas calibrations provided by Airgas. Hydrogen was calibrated to 6.063% H 2 in argon, and 10 samples had a standard deviation of 0.051%. Carbon monoxide was calibrated to 9.568% CO in N 2 , and 10 samples had a standard deviation of 0.023%. Methane was calibrated to 20.000% CH 4 in N 2 , and 10 samples had a standard deviation of 0.035%. CO 2 , O 2 , and N 2 were calibrated using dry air. Water was calibrated by using a target 1:1 ratio injected and vaporized in the reactor with air for 10 measurements with the total sum of products forced to 100%. This closed to a water amount of 47.85% with a standard deviation of 0.76% over 10 samples. Ethanol and acetaldehyde were calibrated by mixing with water to a known molar ratio and calibrating by liquid injection of the diluted sample and comparison to the water amount measured to avoid any homogeneous decomposition arising from flow through the reactor. Sample amounts were calculated from calibrations by measuring the area of the peaks and comparing to the areas of peaks at the calibration composition. [0067] Bar graphs showing product distribution and activity were made by scaling the product distribution such that the total height is the total ethanol conversion while the internal product distribution is represented by the relative size of each component. Error bars were calculated by using the standard deviation of each scaled component amount over the 36 measurements, scaled proportionally by the amount each component is scaled. For each component, this error is estimated as [0000] σ A total =√{square root over ((σ A F ) 2 +(σ F A ) 2 )}{square root over ((σ A F ) 2 +(σ F A ) 2 )} [0000] where A is the fraction of total products for component A, σ A is the standard deviation in the fraction of total products for component A over the 36 measurements, F is the total ethanol conversion percent, and σ F is the standard deviation of the ethanol conversion percent over the 36 measurements. [0068] Homogeneous decomposition was measured by injecting a 1:10 ethanol/water mixture into the reactor with no catalyst present. At 300° C., homogeneous decomposition showed 18.5% conversion of ethanol to acetaldehyde estimated as the ratio of measured acetaldehyde to the sum of the measured acetaldehyde and measured ethanol. Essentially no H 2 or CH 4 were measured. Catalysis is likely taking place in the tubing, which contains nickel, and on the stainless steel filter elements, so by placing the catalyst powder as early as possible in the flow path, subsequent dehydrogenation is limited. [0069] XRD crystallite sizes were determined by using the in situ furnace attachment for the PANalytical X'Pert PRO diffractometer with the X'Celerator detector and a Cu Kα source. Spectra were analyzed using Jade software, and the peak width was used to calculate average nanocrystallite size by fitting each peak to a Pearson-VH curve with no skewness. [0070] TEM images were taken using a JEOL 2010 electron microscope at 200 keV. EDS was done using a GATAN detector in STEM mode on a JEOL 2010F with a field emission gun. BET data were collected using the Micromeritics ASAP 2020, and pore size distributions were estimated by using Micromeritics DFT Plus software with the original density functional theory model, with N 2 at 77 K on carbon with slit pores. [0071] Overall conversion was calculated as the ratio of ethanol consumed to ethanol injected, estimated using the amount of nitrogen detected as an internal standard along with the known molar ratio of nitrogen to ethanol at the inlet. The ratio of N 2 to ethanol at the inlet is 1.33:1 based on the total flow rate of air and ethanol, so the conversion is calculated as [0000] conv   % = 1 - [ EtOH ] [ N 2 ] / 1.33 [0000] where [EtOH] is the measured molar amount of ethanol in the output stream and [N 2 ] is the measured molar amount of nitrogen in the output stream. [0072] Composition was calculated as the ratio of a given product to the total sum of products including only CO 2 , H 2 , CO, CH 4 , and acetaldehyde [0000] X   % = [ X ] ∑ i  [ i ] [0000] where X % is the calculated fraction for product X, and [X] is the molar amount of product X. The fractions were then scaled down by [0000] X %= X %×Conv % [0000] for easier display in a stacked bar chart. Water was consumed during this reaction, so the molar ratio of hydrogen to carbon could vary depending on the amount of steam reforming that occurred. In experiments, the actual measured H/C ratio varied quite a bit, from as low as ˜3:1 at low temperatures to ˜6:1 at high temperatures. [0073] Gas chromatography was used to take 36 samples over 21 h at temperatures ranging from 200 to 400° C. using 1000 mg of either M13-templated or untemplated catalyst (˜12,000 h −1 GHSV). In both cases, complete conversion occurred at 300° C. with approximately 60% H 2 , less than 0.5% CO, and no acetaldehyde in the product distribution. The best results in literature under similar conditions used Rh—Ni@CeO 2 and Co@CeO 2 catalysts with 90%+ethanol conversion, but with 8-10% CO and 2-7% acetaldehyde in the product distribution, making the new catalysts preferable for use in fuel cells, where CO can act as a poison. See, e.g., Kugai, J.; et al. J. Catal. 2006, 238, 430-440; Kugai, J.; et al. Catal. Lett. 2005, 101, 255; and Llorca, J.; et al. J. Catal. 2002, 209, 306-317, each of which is incorporated by reference in its entirety. The untemplated and M13-templated catalyst showed similar product distributions under these conditions. [0074] Increasing the GHSV from 12,000 to 36,000 h −1 at 300° C. by decreasing the amount of catalyst at the same input flow rate resulted in some decrease in activity accompanied by more CO and acetaldehyde with less CH 4 , but ethanol conversion remained above 95%. Both catalysts showed similar product distributions. Samples without rhodium were also tested. In the nickel-only samples, the activity of the 10% Ni@CeO 2 catalyst was particularly notable in that nickel alone on CeO 2 achieved 100% ethanol conversion with an excellent product distribution, outperforming the mixed rhodium-nickel catalysts at 400° C. primarily due to the decrease in the amount of methane seen (8 to 2%) in the product distribution. Performance dropped off quickly as temperature was decreased, demonstrating that the rhodium was necessary for low temperature conversion. Conversion over the nickel only catalyst was steady over 20 h. The nickel-only catalyst performed more poorly when templated onto M13 than when left untemplated. This decreased performance suggested that impurities remaining from the biological material were contaminating the catalyst and reducing activity. For example, residual carbon, sulfur, phosphorus, or other biologically common elements may reduce the activity of the supported catalyst. This deactivation was not seen in the catalyst made with added rhodium. [0075] In order to investigate the long-term thermal stability, catalysts were also tested at 450° C. and 120,000 h −1 GHSV by decreasing the amount of catalyst to 100 mg. Under these conditions, M13-templated catalysts showed near complete conversion (99-100% ethanol conversion) and steady performance over 52 h with 70% H 2 and about 5% CH 4 , 3% CO, and 1% acetaldehyde in the product stream. At similar flow rates and temperatures, Rh—Ni@CeO 2 catalysts reported in literature showed complete conversion, but with 50% H 2 and 19% CH 4 , while Co@CeO 2 catalysts produced 70% H 2 , 9% CO, and 2% acetaldehyde. See, e.g., Kugai, J.; et al. J. Catal. 2006, 238, 430-440; Kugai, J.; et al. Catal. Lett. 2005, 101, 255; and Llorca, J.; et al. J. Catal. 2002, 209, 306-317; Wang, H. et al. Catal. Today 2007, 129, 305-312, each of which is incorporated by reference in its entirety. [0076] M13-templated catalyst showed improved thermal stability compared to untemplated catalyst through a combination of resistance to surface deactivation on rhodium and less phase segregation. While M13-templated catalyst showed steady output over a 52 h measurement, untemplated catalyst showed decreased conversion over time, as shown in FIGS. 9A-9C ((a) With M13 templating, total conversion dropped by only 1% over 52 h; (b) Untemplated catalyst showed total conversion dropping by 4% and decreased hydrogen in the product fraction over 52 h. (c) Faster deactivation is seen in a second 52 h test of untemplated catalyst after regeneration under air for 1 h, with total conversion dropping by 10%.). The decreased conversion was partially recovered by exposing the catalyst to air for a short time, indicating a surface deactivation most likely caused by carbon buildup. However, a second 52 h measurement of the reactivated untemplated catalyst showed more rapid deactivation, indicating that the degradation of the catalyst was also caused by long-term effects. Nanowires were not tested a second time as they did not show noticeable deactivation over the first test. [0077] XRD of the catalyst samples put on stream for stability tests shows that, in both cases, impurity phases begin to appear ( FIGS. 9D-9E ; (d) XRD of M13-templated catalyst after 52 h on stream. Peaks for NiO, Rh 2 O 3 , and CeO 2 were seen. (e) XRD of untemplated catalyst after two 52 h measurements with 1 h of regeneration under air. CeO 2 and NaCl peaks are seen, accompanied by Ni—Rh oxides. The double peak at 30° is characteristic of NiRh 2 O 4 .). In the case of M13-templated catalyst, small NiO and Rh 2 O 3 peaks were seen after a 52 h measurement at 450° C. and 120,000 h −1 GHSV. In the case of the untemplated sample, while NiO and Rh 2 O 3 may be forming, a double peak at 30° suggested the formation of more complex mixed oxides such as NiRh 2 O 4 after two 52 h measurements at 450° C. and 120,000 h −1 GHSV. On the basis of XRD peak broadening, the characteristic size of the NiO phases in the templated catalyst after 52 h on stream was ˜14 nm, while the Rh 2 O 3 phases were ˜37 nm. In the untemplated sample after 105 h, the NiRh 2 O 4 phase showed a characteristic size of ˜52 nm. The more complex mixed nickel rhodium oxide phase was not seen in the M13-templated catalyst, suggesting that the extent to which nickel oxide and rhodium oxides mixed to form mixed nickel rhodium oxides may play a role in the permanent deactivation of the catalyst over time. [0078] To determine what role chlorine played in the catalytic activity of this system, 1% Rh/10% Ni@CeO 2 was formed using cerium, rhodium, and nickel nitrate precursors. These particles performed poorly at 200° C. compared to the particles synthesized from chloride precursors. While untemplated 1% Rh/10% Ni@CeO 2 nanoparticles made from chloride precursors were still fairly active at 200° C. with 73% ethanol conversion, 1% Rh/10% Ni@CeO2 catalysts made from nitrates only showed 45% ethanol conversion. The poor performance of the catalysts made using only nitrates suggested that the chlorine ions are playing a role in the activity. [0079] Other embodiments are within the scope of the following claims.

A method of making a metal oxide nanoparticle comprising contacting an aqueous solution of a metal salt with an oxidant. The method is safe, environmentally benign, and uses readily available precursors. The size of the nanoparticles, which can be as small as 1 nm or smaller, can be controlled by selecting appropriate conditions. The method is compatible with biologically derived scaffolds, such as virus particles chosen to bind a desired material. The resulting nanoparticles can be porous and provide advantageous properties as a catalyst.

FIELD OF THE INVENTION This invention relates to the method of making a needlework graph and more specifically to the method of graphing by the average person, who is not skilled in the art of graphing, of a specific colored design desired to be reproduced by needlework on canvas or fabric. BACKGROUND OF THE INVENTION It is known to provide needlework graphs to be used for the needlework reproduction on canvas or fabric of the design shown on the graph. The closest known prior art graphs comprise sheets of smooth-surfaced transparent plastic printed with intersecting lines and arranged to define spaces that are either square, rectangular, or another shape, depending on the type of needlework to be used in reproducing the selected design. The spaces in the graph correspond to the stitches in the canvas or fabric on which the design will be reproduced. The design is formed on the graph by coloring the spaces in the graph with appropriate colors to form the intended design, and the design is reproduced on canvas, for example, by locating stitches in the canvas that correspond to the overlying spaces in the graph and crossing those stitches with yarn of the same color as the corresponding spaces in the graph. The said graph of the prior art is completed by a user placing a selected printed sheet of the smooth-surfaced transparent plastic over a specific colored design and coloring the spaces overlying each color in the selected design with correspondingly colored felt-tipped markers of the type commonly known as MAGIC MARKER felt tip pens. Difficulty has been experienced in matching the colors on the selected design with colors of so-called MAGIC MARKER felt tip pens because of the wide discrepancy between the infinite variety of colors on designs to be selected and the limited number of colors available when selecting MAGIC MARKER felt tip pens. Other objections to the use of MAGIC MARKER felt tip pens to complete the said prior art graphs are that the liquid-based MAGIC MARKER felt tip pens sometimes smear in use; and the MAGIC MARKER felt tip pens dry out and become unusable after a period of time. The users of the prior art printed sheets of smooth-surfaced transparent plastic are limited to the use of MAGIC MARKER felt tip pens for coloring the spaces on said smooth-surfaced sheets because neither colored pencils or anything else will stick to the smooth-surfaced plastic sheets. SUMMARY OF THE INVENTION It is a primary object of this invention to provide a method of making a graph for needlework that enables an average person interested in reproducing a specific colored design by needlework, for which there is no existing graph, to quickly and easily graph the colored design for reproduction by such needlework as cross stitch, needlepoint, quilting, smocking, duplicate stitch, or knitting. According to this invention, a plurality of intersecting lines are printed, without a design, on a transparent plastic sheet, having a matte finish on one surface, with different sizes of squares, rectangles, etc. that give a spread of sizes to form transparent foundations for the finished graphs. The type of plastic on which the patterns of intersecting lines are printed is preferably sheets of plastic known in the engineering trade as TELEDYNE POST Style #18×4 drafting film. In use, the person desiring to make a needlework graph of a colored design first selects a transparent foundation appropriately printed as described above for the definition of detail to be used in reproducing the design. The appropriate transparent foundation is placed over the colored design to be reproduced, and colored pencils are then used to copy the underlying design onto the overlying spaces on the superposed transparent foundation. That completes the graph and the graph is then used in the conventional manner to reproduce the design by needlework on canvas or fabric. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sheet of prior art TELEDYNE POST Style #18×4 drafting film; FIG. 2 is a greatly enlarged sectional view taken substantially along the line 2--2 in FIG. 1, showing the matte finish on one surface of the prior art drafting film; FIGS. 3, 4, and 5 are top plan views of the prior art drafting film shown in FIGS. 1 and 2, after being printed to form a transparent foundation for a needlepoint graph, a duplicate stitch graph, and a cross stitch graph, respectively; FIG. 6 is a plan view of a colored design to be reproduced by needlework, the hatching illustrating different colors in the specific design; FIG. 7 is an exploded perspective view of the transparent foundation shown in FIG. 5 superposed over the colored design shown in FIG. 6, and illustrating the completion of the graph by the tracing with colored pencils of colors on the transparent foundation corresponding to the subjacent colors in the design of FIG. 6; and FIG. 8 is a plan view of a reproduction by cross stitch of the design of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION Referring more specifically to the drawings, the numeral 10 broadly designates a sheet of prior art tracing film known in the engineering trade as TELEDYNE POST Style #18×4 drafting film. It is a coated, matte polyester product. The film base is a crystalized, aligned polyester (polyethylene terphthalate) film. The crystallization and alignment enhances the dimensional stability over ordinary film products, such as packaging films. The coating on the film is comprised of silica (silicon dioxide) dispersed in an acrylic (polymethyl methacrylate) resin. The silica provides a matte surface for drafting, plotting, coating, coloring, etc. The acrylic resin binder is hard, and one of the more light stable, discoloration resistant materials available. The matte surface on the film 10 is indicated at 11 in FIG. 2. According to the invention, the prior art tracing film 10 is printed with a plurality of intersecting lines 12 to form a transparent foundation 13 for making a needlework graph (FIGS. 3, 4, and 5). In FIG. 3, the intersecting lines 12 form diagonally extending rows of ellipses 14 for making a needlepoint graph; in FIG. 4, the intersecting lines 12 form rectangles 15 for making a duplicate stitch graph; and in FIG. 5, the intersecting lines 12 form squares 16 for making a cross stitch graph. The sheets of film 10 are preferably cut to a desired size, such as 8.5×11 inches. The transparent foundations 13 are printed in different sizes for the convenience of the user in making graphs for needlework having the desired definition of detail. FIG. 6 shows an example of a specific colored design to be reproduced by needlework. It is a floral design, broadly indicated at 20, on wallpaper 21. The floral design 20 is hatched to indicate the colors in the design. The stem 22 and the leaf 23 are green; the leaf 24 is brown; the leaf 25 and the bud 26 are red; and the foliage 27 is blue. FIG. 7 shows the transparent foundation 13 of FIG. 5 positioned in superposed relation to the design 20 to graph the design by using water color pens, chemical colored pens, or colored pencils 30 to copy the colors in the design onto the matte surface 11 of the foundation 13. The use of colored pencils to copy the colors in the design on the matte surface 11 of the foundation 13 is preferable because colored pencils are readily available in at least one hundred and twenty (120) different colors and shades of color, making it relatively easy to match the colors in the design. Another advantage of using colored pencils is that it is easier to erase and wash off the marks made by colored pencils than the marks made by other types of markers. A brown colored pencil 30 is shown being used to color those spaces on the transparent foundation that overlie the brown leaf 24. A green colored pencil has already been used to color the spaces in the transparent foundation that cover the stem 22 and leaf 23. The graph of the colored design 20 will be completed by using a red colored pencil to color the spaces overlying the leaf 25 and bud 26, and a blue colored pencil to color those squares in the transparent foundation 13 that overlie the foliage 27. The graphed design 31 will be used in the conventional manner to reproduce the design 20 by cross stitch 32 on canvas 33, as shown on the leaves 23 and 24 in FIG. 8. There is thus provided a novel method for an average person who is not skilled in graphing to graph a colored design for reproduction by needlework. Although specific terms have been employed in describing the invention, they have been used in a generic and descriptive sense only and not for the purpose of limitation.

This invention provides a graphing system that enables an average person interested in reproducing a colored design by needlework, for which there is no existing graph, to quickly and easily graph the colored design for reproduction by such needlework as cross stitch, needlepoint, quilting, smocking, duplicate stitch, or knitting.

CROSS REFERENCE TO RELATED APPLICATIONS This application is the National Phase of International Application PCT/EP2004/052765 filed Nov. 3, 2004 which designated the U.S. and which claims priority to European (EP) Pat. App. No. 03256951.9 filed Nov. 4, 2003. The noted applications are incorporated herein by reference. TECHNICAL FIELD The present invention relates to curable compositions containing at least two components; each component contains materials (generally monomers/oligomers/polymers) that react with materials in the other component to form a cured resin. For simplicity, such compositions will be referred to as “two component” systems, since there will generally be only two components, but it will be understood that more than two components can be used and the “two component” should be understood accordingly. When the two components are mixed, they form a resin that cures; the curing time will depend on many factors e.g. the nature of the curable materials and the ambient temperature. Examples of 2-component resins include epoxy/amine; epoxy/acrylic/amine and isocyanate/polyol systems and also hybrid systems such as epoxy/isocyanate-polyol/amines; epoxy/anhydride; and cyclocarbonate/epoxy/amine systems. Such materials are used in a wide variety of fields, for example adhesives, modelling pastes, coatings, sealants, putties, mastics, stopping compounds, caulking materials, encapsulants and surface coatings such as paints. BACKGROUND ART Two-part components are widely used in many industries for many purposes, including: 1) Model making: Within the automotive, aerospace, rail, wind turbines energy fields and marine industries there is a need to produce dimensionally accurate master models, particularly of large format. These models are used by engineers for the conceptual design of the individual components utilised in the final product. More and more, such models are tested for technical and functional use, thus requiring technical material properties. U.S. Pat. Nos. 5,707,477 and 5,773,047 describe a method for making prepreg parts for use in the aerospace industry where pliable solid patties prepared from syntactic epoxy material are hand-applied to a block made by stacking successive layers of aluminium honeycomb core. The entire resulting structure is then heated to effect cure of the patties. However, this approach is again labour intensive, in that it involves hand application of the pliable solid patties to the honeycomb core. It also requires heating of the entire structure in order to cure the applied patties. The resulting models are also of relatively high density. WO02/20261 describes a method of making models by making a sub-structure, applying a foamed mixed two-component resin (epoxy/amine or isocyanate/polyol systems) to the substructure to form a continuous layer, curing the resin and machining or hand cutting the cured resin to shape. This method is referred to as “net size casting” using a “seamless modelling paste” (SMP). The paste includes a thixotropic agent to increase the thixotropy of the paste after mixing and dispensing onto the substructure to ensure that the paste does not sag during curing. Amines are given as examples of suitable thixotropic agents. 2) Adhesives In the aerospace, auto, rail, structural and other industries, two-part adhesives are widely used, e.g. in wind turbine blade bonding and to bond other structures. Thixotropic and gap filling adhesives are of special interest for successful bonding of large structures in order to achieve even, stress-free bonding, without flow out at the edges of the structures being bonded. Thixotropic high strength adhesives are also useful if they can be dispensed as ‘ropes’ onto vertical or slanting surfaces to adhere protective barrier panelling, e.g. on the sides of liquid gas tanks or fuel carriers 3) Component manufacture Two-part curable resins are also used to form heavy electrical mouldings. Of especial interest are flowable thermosetting compositions which can mix very well, set and cure evenly in the casings of large transformers. 4) Paints and coatings Two-part curable resins are also used to form paints, e.g. automotive paints, and coatings and mouldings. The above are given as examples of the use of two-component curable resins but the list is by no means exhaustive. It is important that the individual components are flowable so that they can readily be mixed, especially when using machines that both mix and dispense the mixed composition. This sets certain limits on the viscosities that can be utilised and, in turn, sets limits on fillers and thixotropic agents that can be used, ultimately setting limits on the final properties that can be reached. In many applications there is a need for the two-component composition to have a high viscosity shortly after mixing to provide a resistance to slump, i.e. a change in shape once the mixed composition has been placed in a desired location. The degree of non-slumping required can even be that of retaining almost exactly the shape and dimensions achieved by extruding the compositions through a shaped orifice. This non-slump texture is frequently obtained by dispersing a thixotropic agent such as a hydrophilic fumed silica in one of the components to blends, provided sufficient thixotropic agent is used, that generally retain their shape and non-slump properties until they are gelled and cured. A thixotropic composition can be defined as a composition whose viscosity under shear is lower than under no shear. However, adding agents to increase the viscosity after mixing generally requires the individual components to also have high viscosities, even though they are thixotropic to a degree and hence have lower viscosities under shear than under no shear. The high viscosities of the components leads to difficulty in mixing the components together especially when mixing is achieved automatically during the dispensing of the mixture, leading to poor mixing of the components and hence a reduction in the properties of the cured resin. This is especially true when using platelet nanofillers that increase the viscosity of compositions substantially, even at low loadings if highly dispersed. Nanoparticles Nanoparticles are particles of nanosize i.e. having at least one dimension on nanometer scale. They can be derived of naturally occuring- or synthetized-clay minerals, hence the name of nanoclays. Clays are generally phyllosilicates such as of the smectite group, for example a bentonite, montmorillonite, hectorite, saponite or the like. The surface of the clay can be modified to become organophilic hence the name of organoclays. The inorganic exchangeable cations which occurs in natural or synthetic clay mineral are replaced by organic cations comprising sufficient carbon atoms to render the surface of the cation-exchanged clay hydrophobic and organophilic. For example U.S. Pat. No. 4,810,734 discloses phyllosilicates which can be treated with a quaternary or other ammonium salt of a primary, secondary or tertiary organic amine in the presence of a dispersing medium. Nanoclays are often plate-like materials also called platelets. Platelets have 2 dimensions higher than the third one, they have a planar extent and a thickness. Fibers have one dimension higher than the 2 others, no planar extent but a high length. Researchers have concentrated on four nanoclays as potential nanoscale particles (nanoparticles): a) hydrotalcite, b) octasilicate, c) mica fluoride and d) montmorillonite. The first two have limitations both from a physical and a cost standpoint. The last two are used in commercial nanocomposites. Mica fluoride is a synthetic silicate, montmorillonite (MMT) is a natural one. The theoretical formula for montmorillonite is: M + y (Al 2-y Mg y )(Si 4 )O 10 (OH) 2 *n H 2 O Ionic phyllosilicates have a sheet structure. At the Angstrom scale, they form platelets, which can be 0.3 preferably 0.7 to 1 nm thick and several hundred nanometers (about 100-1000 nm) long and wide. As a result, individual sheets may have aspect ratios (Length/Thickness, L/T) varying from 200-1000 or even higher and, after purification, the majority of the platelets have aspect ratios in the 200-400 range. In other words, these sheets usually measure approximately 200×1 nm (L×T). These platelets are stacked into primary particles and these primary particles are stacked together to form aggregates (usually about 10-30 μm in size). The silicate layers form stacks with a gap in between them called the “interlayer” or “gallery”. Isomorphic substitution within the layers (Mg 2+ replaces Al 3+ ) generates negative charges that are counterbalanced by alkali or alkaline earth cations situated in the interlayer. Such clays are not necessarily compatible with polymers since, due to their small size, surface interactions such as hydrogen bonding become magnified. Thus, the ability to disperse the clays within some resins is limited and at the beginning, only hydrophilic polymers (e.g. PVA) were compatible with the clays because silicate clays are naturally hydrophilic. But, it was found that the inorganic cations situated in the interlayer can be substituted by other cations. Cationic exchange with large cationic surfactants such as alkyl ammonium-ions, increases the spacing between the layers and reduces the surface energy of the filler. Therefore, these modified clays (organoclays) are more compatible with polymers and form polymer-layered silicate nanocomposites. Various companies (e.g. Southern Clays (of 1212 Church Street, Gonzales, Tex. USA 8629), Süd Chemie, Nanocor, etc.) provide a whole series of both modified and natural nano clays, which are montmorillonites. Apart from montmorillonites, hectorites and saponites are the most commonly used layered silicates. A nanocomposite is a dispersion, often a near-molecular blend, of resin molecules and nanoscale particles. Nanocomposites can be formed in one of the following three ways: a) melt blending synthesis, b) solvent based synthesis and c) in-situ polymerization, as is known in the art. There are three structurally different types of nanocomposites: 1) intercalated (individual monomers and polymers are sandwiched between silicate layers) 2) exfoliated (a “sea” of polymer with “rafts” of silicate), and 3) end-tethered (a whole silicate or a single layer of a silicate is attached to the end of a polymer chain). There has been immense activity in the use of nano clay composites in recent years, for use in polyolefins, methacrylates (e.g. PMMA), polyamides, bio-polymers, polyurethanes, phenols, polycarbonates, to achieve benefits and claims have been made for increase in strength, flame retardency, barrier protection and high temperature resistance. U.S. Pat. No. 6,579,927 details the formation of a nanomaterial where the clay material is homogeneously distributed throughout the polymeric matrix. The resultant nanocomposites could be moulded via injection moulding or extrusion processes. Example 16 of the patent FR 1,452,942 discloses a two-parts epoxy adhesive composition whose hardener part contains silica, hardener, carbon an silica aerogel whereas the resin part contains epoxy resin, bisphenol A and ammonium bentonite. U.S. Pat. No. 6,197,849 details the preparation of organophilic phyllosilicates by treating naturally occurring or synthetic phyllosilicates with a salt of a quaternary or other cyclic amidine based compound. The patents covers polymeric systems, preferably epoxy resins, polyurethane and rubbers containing such organophilic phyllosilicates. The organophilic phyllosilicates may be added either to the resin or else to the hardener. EP 0 267 341 A1 discloses a resin composition comprising smectite organoclays of improved dispersibility. In an example, the organoclay is incorporated into component A of a two-Pack Epoxy enamel. EP 1 209 189 A1 discloses polymer foams containing nanoclay described as nanosized clay of plate-like form, dispersed therein. For example, clay platelet CLOISITE® 10A is dispersed in the polyol part of a polyurethane foam. An article entitled “Polyurethane nanocomposites Containing Laminated Anisotropic Nanoparticles Derived from Organophilic Layered Silicates” by Carsten Zilg, published in Advanced materials, VCH, Verlagsgesellschaft, Weinheim, D E, vol. 11, No.1 07 Jan. 1999, pages 49-52, discloses a polyurethane nanocomposite material prepared from a polyol dispersion containing ion-exchanged organophilic fluoromica and an isocyanate component. The incorporation of nano clay materials into polymer matrices, to enjoy the above-mentioned benefits, is not straight forward, however. The highly anisotropic nature and large surface area of nano clays can give problems in processing of polymers, particularly where 2 component reactive systems are envisaged. High loadings of the nano clay can result in unacceptably high viscosities, yet high viscosity is what is sought to achieve anti-slump characteristics in reactive systems. A problem underlying the present invention is to develop two component systems where the components individually are of reasonably low viscosity for ease of processing, particularly for machine dispensed materials, yet which develop high viscosity when the components are mixed together to form a resin that is undergoing curing. None of the above mentioned prior art documents provide a clue to solve that problem. We have found that such a property can be achieved from particular blends of platelet additives, e.g. nano clays, and preferably other fillers, for two component reactive systems, combined with distribution of the nano clay material between the two components. Unexpectedly, exceptional non-slump characteristics are achieved indicating a synergism between the blended platelet additives and the curable resin matrix, over and beyond simple addition effects. A general problem underlying the present invention is to provide a two component composition containing platelet nanofillers that can more readily be mixed, even at high nanofiller loadings. Another aspect of a problem underlying the present invention is to provide a two component composition that, when mixed, has good anti-slumping properties and therefore has a high viscosity at rest while at the same time the individual components have a relatively low viscosity to ensure good mixing. It has now been found that two-component compositions with platelet nanofillers present in both components (or in at least two components for a multi-component composition) are easier to mix. In addition, it has been found that the mixed composition can have unexpectedly higher viscosities than the individual components have. This opens the way to making curable two part compositions having, when the components are mixed, high viscosities (and hence good anti-slump properties) from components that have relatively low viscosities, allowing them to be readily mixed. This invention therefore unexpectedly extends considerably the capability to use modern thixotropes synergistically within the application process, such that both the requirements for mixing and applying the mixed components and for the final cured product can be expanded SUMMARY OF THE INVENTION One aspect of the invention relates to a composition comprising at least two separate reactive components that when mixed together form a reactive resin that undergoes curing, wherein: at least two of the separate reactive components each includes a filler having a platelet structure (“platelet filler”) dispersed in the component. This permits to obtain a mixture whose viscosity is higher than the viscosity of each of the two separate components. In another aspect of the invention, the composition comprising at least two separate reactive components that when mixed together form a reactive resin that undergoes curing, is characterised in that the viscosity of the mixture is higher than the viscosity of each of the two separate components. Another aspect of this invention relates to a composition comprising at least two reactive components that when mixed together form a reactive resin that undergoes curing, wherein the components, or at least two of the components if there are three or more components, include a filler having a platelet structure, the platelets having a thickness 5 microns or less, preferably less than 1 μm, more preferably less than 25 Å(˜2.5 nm), especially less than 10 Å (˜1 nm), and most preferably between 4-8 Å (˜0.5-0.8 nm), and an aspect ratio (length/thickness) higher than 10, more preferably higher than 50 and most preferably higher than 100 or a mixture thereof. The platelets are preferably separable from each other under shear within the composition. The present invention also provides a method of mixing the reactive components of the composition defined in the preceding paragraph. DETAILED DESCRIPTION OF THE INVENTION The presence of the platelet in the components can provide an additional advantage of improving surface char formation and flame retardancy of the cured resin. The nanoscale platelet filler may be in the form of a nanocomposite, which is a dispersion of such a filler in a polymer or resin. The filler may be mica or glass flakes or a clay, e.g. a natural or modified montmorillonite. The nanoscale platelet filler should, as specified above, be present in at least two of the reactive components. Preferably no one component should contain more than 80% by weight of the platelet filler content of the final cured resin since that would generally increase the viscosity of that component to an unacceptably high level. More preferably, the maximum loading of the platelet filler in any one component is 75%, e.g. 60% by weight or less of the total platelet filler content of the final cured resin. Each component preferably includes 0.5 to 10% by weight of the platelet filler, more preferably 1 to 7%, e.g. 2 to 4%. The nanoscale platelet filler may be surface treated, e.g. with amines, surfactants, reactive materials, (e.g. silanes or siloxanes) to make them compatible with the other ingredients of the component it is incorporated in. Especially preferred are platelet fillers treated with alkyl quaternary ammonium ions that are retained on their surface. Such fillers are commercially available, e.g. Garamite 1958 obtainable from Southern Clay Products Inc. It has been found that the viscosity of curable compositions formed by mixing two reactive components together can be substantially increased as compared to the viscosities of the individual components especially if, in addition to the platelet filler, minerals, e.g. calcium carbonate, aluminium trihydrate, talc and silicas, which interact with the platelet fillers are incorporated into one or more, and preferably each, of the components. Especially preferred are (a) platelet fillers that have been subject to ion exchange, e.g. to incorporate ammonium ions such as alkyl quaternary ammonium ions, and (b) minerals such as talc, calcium carbonate and silicas that interact with the ammonium-containing platelet filler. Typical densities of the cured resin containing mineral filler alone will be ˜1 to 3 g/cc. Additional thixotropes may also be added in the form of a silica gel, which preferably contains various siloxane and silanol groups. It is not required to use the same nanoscale platelet filler in the various components and different platelet materials could be used. However, for sake of simplicity and ensured compatibility, the platelet filler is preferably the same in each of the two reactive components. In addition, mixes of platelet materials could be incorporated into any of the components. The two reactive components may be chosen from the components of any thermosetting resin. The two reactive components preferably belong to one of the following reactive systems: Epoxy/Amine Epoxy/Acrylic/Amine Isocyanate/Polyol Alternative hybrid systems may be used, e.g.: epoxy/isocyanate-polyol/amines Epoxy/Anhydride Cyclocarbonate/epoxy/amine The components may be foamable to reduce the weight of the cured resin by incorporating a foaming agent in one or more of the components and/or by frothing the mixed resin by mechanical stirring and/or blowing gas, e.g. air, into it. The foaming agent is preferably thermal- or radiation-activated to produce gas bubbles to expand the matrix of the resin. The molecular weight and functionality of the monomer/oligomer/polymer content of the components should be chosen to give appropriate properties, e.g. densities, in the final cured resin. A range of different molecular weights may be used. Other fillers may be incorporated into the components such as: minerals e.g. talc, calcium carbonate, silicas. Typical densities of the cured resin containing mineraly filler alone will be. ˜1 to 3 g/cc microballoons, which are glass or polymeric hollow spheres, and can be used to achieve a cured resin having a lower density, e.g. ˜0.4 to 0.9 g/cc. Air or gas can be introduced into the resin being cured either by foaming agents or by mechanically frothing. The components may be mixed manually or mechanically, e.g. using a planetary mixer, but it is preferred to mix the components by static mixing, i.e. dispensing the components from separate component cartridges into a common conduit, where the components are mixed as they pass through the conduit; static blades in the conduits may assist in the mixing process. The viscosities of the separate components (preferably measured at a frequency of 0.01593 Hz under the conditions discussed later in connection with the specific Examples) are preferably less than 300,000 Pa·s (i.e. 300 kPa s); the viscosity of the resin immediately after thorough mixing of the components preferably exceeds 500,000 Pa·s. The resin formed by mixing of the components may be cured at room temperature, which will generally be the case for large structures e.g. aerodynamic wings, wind turbine blades etc, or at elevated temperatures to accelerate the curing, depending on the resin components. The cured resin may be formed to a desired shape, e.g. to form a model, by machine, e.g. using a CAD-controlled machine tool or by hand and the resin may also be trimmed. The cured resin may be in any desired form or shape, e.g. a coating or paint covering, an adhesive deposit (as a film, powder, rope or a three dimensional structure or coherent insert), a paste or putty, or a board that can be subsequently machined. Even when slump is not an especial problem in a given application, e.g. in the formation of an adhesive deposit joining two parts, the high viscosity of the resin as it is curing may well be advantageous, e.g. to keep it in place, especially when applied to vertical or slanted surfaces or the underside of a substrate. The platelet filler may be a modified or unmodified nanoclay or a nanocomposite; such fillers have already been described above. A nanocomposite is a dispersion, often a near-molecular blend, of polymer or curable resin molecules and nanoscale particles. Nanocomposites can be formed, as is known in the art, in one of the following three ways: a) melt blending synthesis, b) solvent based synthesis and c) in-situ polymerization, as is known in the art. There are three structurally different types of nanocomposites: 1) intercalated (individual monomers and polymers are sandwiched between silicate layers) 2) exfoliated (a “sea” of polymer with “rafts” of silicate), and 3) end-tethered (a whole silicate or a single layer of a silicate is attached to the end of a polymer chain). It is important that the platelet filler should be compatible with the compositions of the resin components so that the filler will disperse as individual platelets or a thin stack of platelets in the components. The compatibility can be achieved by a suitable choice of the filler and in particular, in the case of clay compositions, the nature of the surface groups on the particles of clay materials; surface groups can be incorporated by means of an ion exchange process, which can result in the addition of, for example, ammonium quaternary ions to the surface of the platelet clays. A particular clay of interest that can be used with a broad range of two component compositions is Garamite® for example Garamite® 1958 or Garamite® 1210. Garamite® are Theological additives that are blend of minerals which have been organically modified. It is preferably used in an amount of 1 to 5% in epoxy systems. Garamite 1958 is preferred. It is a modified nanoclay and has alkyl quaternary ammonium ions on the surface of a basic bentonite clay structure. The organically modified silicate Garamite 1958 is commercially available and is used as a Theological additive in numerous polymer systems such as epoxies and unsaturated polyesters. The addition of Garamite 1958 has been observed to increase the thixotropy of polymer systems and reduce the tendency for sag. This Theological additive can be used as an alternative to other thixotropic agents such as fumed silica. Another particular clay of interest that can be used with a broad range of two component compositions are Cloisite® additives which consist of organically modified nanometer scale, layered magnesium aluminium silicate platelets of montmorillonite type. The silicate platelets that Cloisite® are derived from are 1 nanometer thick and 40 to 150 nanometer across. Specific examples are Cloisite® 93A and Cloisite® 25A. Surface of Cloisite® 93A has been modified by M2HT; methyl, dihydrogenated Tallow ammonium N+(H)(HT) 2CH3 where HT is Hydrogenated Tallow (approx. 65% C18, 30% C16, 5% C14) with anion:HSO4 − . Surface of Cloisite® 25A has been modified by 2MHTL8; dimethyl, dihydrogenatedtallow, 2-ethylhexyl quaternary ammonium with anion methylsulfate. The Cloisite® additives are exfoliated preferably until the individual platelets no longer exhibit an XRD deflection indicating that the platelets are at least 7 nm apart. After exfoliation into primary platelets the platelets are distributed. As shown in the subsequent examples, the presence of platelet fillers, e.g. Garamite 1958, within the reactive components of a two part resin composition results in the formation of relatively low viscosity pastes possessing a cream like consistency. It has been found surprisingly that when the two components of the two part resin composition both contain this rheological agent and are mixed together in varying proportion (such as 1:1 and 2:1) to form a resin undergoing curing, the resin has an unexpected and significant relatively high viscosity. This phenomenon imparts an advantageous degree of slump resistance. In one embodiment, one of the reactive components preferable comprises an epoxy resin and the other component includes a hardener for the epoxy resin, e.g. a polyamine or a polyol, or poly-anhydride, or polycyclocarbonate, or hybrids thereof. The epoxy resin may consist of one or more epoxy resins that are themselves liquid or may be a liquid mixture of one or more solid epoxy resins with one or more liquid epoxy resins or may be one or more solid epoxy resins dissolved in a diluent; diluents are conventionally used in epoxy resin compositions and are well-known. The epoxy resin may be a polyglycidyl ether of a polyhydric alcohol such as 1,4-butanediol or 1,3-propanediol or, preferably, a polyglycidyl ether of a polyhydric phenol, for example a bisphenol such as bis(4-hydroxyphenyl)methane (bisphenol F) or 2,2-bis-(4-hydroxyphenyl)propane (bisphenol A) or a novolak formed from formaldehyde and a phenol such as phenol itself or a cresol, or a mixture of two or more such polyglycidyl ethers. Polyglycidyl ethers of bisphenol A are especially preferred. The epoxy resin, particularly where it comprises a solid epoxy resin, may contain one or more epoxy-functional diluents, usually monoepoxides, or non-epoxide diluents, such as the monoepoxide and non-epoxide diluents conventionally used in curable epoxy resin compositions. Examples of amines suitable for use as the amine hardener include those aliphatic, cycloaliphatic, aromatic, araliphatic and heterocyclic amines known as hardeners for epoxy resins, including: alkylenediamines such as ethylenediamine or butane- 1,4-diamine; polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine or tripropylenetetramine; N-hydroxyalkyl derivatives of polyalkylene polyamines such as N-(hydroxyethyl)diethylenetriamine or mon-N-2-hydroxypropyl derivative of triethylenetetramine; polyoxyalkylenepolyamines such as polyoxyethylene- and polyoxypropylene-diamines and triamines; N,N-dialkylalkylenediamines such as N,N-dimethylpropane-1,3-diamine or N,N-diethylpropane-1,3-diamine; cycloaliphatic amines having an amino or aminoalkyl group attached to the ring, such as 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine); aromatic amines such as bis(4-aminophenyl)methane or bis(4-aminophenyl)sulphone; amine-terminated adducts of epoxy resins with aliphatic, cycloaliphatic or araliphatic amines as hereinbefore described; N-aminoalkyl-piperazines such as N-(2-aminoethyl)piperazine or N-(3-aminopropyl)piperazine; and polyaminoamides, for example reaction products of polyalkylenepolyamines such as those hereinbefore mentioned with polymerised unsaturated fatty acids, e.g. polymerised vegetable oil acids such as dimerised or trimerised linoleic or ricinoleic acids; or a mixture of two or more of such amines. Aliphatic and cycloaliphatic amine hardeners are usually preferred, including N-hydroxyalkyl derivatives of polyalkylene polyamines, particularly a mono-N-2-hydroxypropyl derivative of triethylenetetramine, and mixtures thereof with polyaminoamide reaction products of polyalkylenepolyamines and polymerised vegetable oil acids and the amine functional reaction products of amines and epoxy group containing compounds. The amount of amine hardener is preferably such as to provide from about 0.75 to 1.25 amino hydrogen equivalents per 1,2-epoxide equivalent of the epoxy resin (1). The hardener may have a dendrimeric structure (e.g. with functional amine, hydroxy or acidic reactive groups). The components may also contain minor amounts of accelerators (e.g. tertiary amines, etc) and latent hardeners (e.g. dicyanamide, or boron—amine complexes) and additives conventionally used in the particular application, such as diluents, fillers (such as calcium carbonate), fibers, pigments, dyes, fire retardants, antifoaming agents, wetting agents and polymeric toughening agents. Preferably, the paste additionally includes molecular sieves, which function as moisture scavengers, and are well known to those skilled in the art, examples being zeolites with open-network structures. Preferably, the paste also includes surfactants or antifoaming agents such as a silicone surfactant like Dabco DC 197 Surfactant, available from Air Products, though other products are commercially available and well known to those skilled in the art. It has also been found that the addition of calcium stearate improves the machinability of the cured material and so its addition is also advantageous. These auxiliary materials may be conveniently added with any or all of the components. Techniques for mechanically mixing the components of a curable two-part curable resin, e.g. modelling pastes, and dispensing the mixed resin are known in the art, e.g. by using Tartler Nodopox machinery. The bulk density of the resulting cured articles is usually 0.8 to 1.3 g/cm 3 , although this will depend on the weight of any filler used, as discussed above. Conveniently, separate tanks are filled with the two components, e.g. resin and hardener. The application of low pressure to the tanks facilitates pumping of the materials. Preferably, pumps deliver the components from the tanks to a mixing block where they are mixed. The residence time in the mixing block, the speed of mechanical stirring and the length of the hose attached to the chamber influence the homogeneity of the mixture. The present invention can be used to make a seamless model free of bond lines; typical steps in making such models are: 1. providing a substructure having an exposed outer surface, 2. applying a modelling paste to the outer surface of the substructure in the form of a continuous layer, 3. curing the continuous layer of applied modelling paste, and 4. machining said cured layer of modelling paste to the desired contour. Cure of the curable resin can be effected in accordance with conventional practice in the particular application. In general, the composition can be allowed to gel (set) at ambient temperature or heated moderately in accordance with conventional practice to accelerate setting. Subsequently, completion of cure may be effected at ambient temperature, moderately elevated temperature or higher temperature as required. Typically, room temperature cure is preferred. This process is particularly useful for producing model and moulds (direct tooling) within the wind/marine/aerospace/rail and auto industries. This type of physical thixotrope enables storage stable pre-mixed components to be produced. Previous chemical thixotrope, for example the system described in U.S. Pat. No. 6,077,886, suffers from a reduction in the mixed thixotrope over time (chemical thixotropic systems tend to slowly react with time and lead to loss of thixotropy) This physical thixotrope allows stable fabrication of large models and moulds (direct tooling) required within the marine/wind turbine/aerospace/rail and auto industries. EXAMPLES The materials of Table 1 are referred to in the following description: TABLE 1 Raw Materials Raw Material Description of Material Supplier Araldite GY 260 Bisphenol A epoxy resin Huntsman Group Vantico Limited Araldite GY 281 Bisphenol F epoxy resin Huntsman Group Vantico Limited IP 262 Isophorone diamine/ Huntsman Group Trimethylhexa- Vantico Limited methylenediamine adduct IP 271 Isophorone diamine/ Huntsman Group Jeffamine D 230 adduct Vantico Limited Dioctyl adipate Di (2-ethylhexyl)adipate Petrochem UK Ltd Araldite DY H/BD Diglycidylether of 1.6 Huntsman Group hexenediol Vantico Limited Apyral 22/33 Aluminium hydroxide Nabaltec Sphericel 110 P8 Borosilicate glass Potters industries Q Cel 5028 Silicic acid, sodium salt, Potters industries boric acid sodium salt, siloxane Creta fine N 100 Calcium carbonate Needham Minerals Limited Coathylene TB 2957 Ethylene-acrylate-acrylic Dupont Polymer acid copolymer Powders SA Calofort S Stearate coated calcium Omya UK carbonate Jeffamine D 230 Polyoxypropylenediamine Huntsman Ruetasolv DI Diisopropyl naphthalene Rutgers Kureha isomers Solvents GmbH Accelerator 399 Triethanolamine, Huntsman piperazine, aminoethylpiperazine Aerosil R202 Silicones and siloxanes, Degussa AG dimethyl-reaction products with silica Aerosil R 8200 Silanamine, hydrolysis Degussa AG products with silica Bentone SD-2 Organic derivative of a Elementis montmorillinite clay Specialties PJ 755 Titanium dioxide/black PJ Colours Ltd iron oxide Garamite 1958 Alkyl quaternary Southern Clay ammonium clay Products Inc Tetraethylene Tetraethylene pentamine Dow Chemical pentamine (TEPA) Company Ltd Aradur 140 Polyamidoimidazoline Huntsman Group Vantico Limited Cloisite 25 Å Modified nanoclay Rockwood Additives Closite 93 Å Modified nanoclay Rockwood Additives Suprasec 2211 isocyanate compound Huntsman Polyurethanes Additive Tl Monofunctional isocyanate Bayer Plc compound Byk 054 Foam destroying polymers Byk Chemie Airflo CC China Clay WBB Devon Clays Ltd Polyol PP50 Ethoxylated Perstorp AB pentaerythritol Poly G85-29 Polyether polyol Arch Chemicals HXA6 Solid glass beads Sovitec France SA 1,4 Butanediol 1,4 Butanediol Albion Chemical Distribution Baylith L powder Molecular sieve Bayer Plc None of the fillers used in the formulations stated in Tables 2-4 and 7-8 have undergone any specific drying procedure before being utilized in the manufacture of these specific constituents. Experimental Procedure In this specification, all percentage values are percentages by weight. Formulations 1 to 3 A general process was used for the manufacture of a first formulation (Formulation 1) of a two-part composition, comprising an epoxy resin component and a hardener component The epoxy resin component is formed in a disperser type mixer as follows: 1. Charge GY 260 (39.520%), GY 281(11.530 %), Aradlite DY HB/D (1.980%), Dioctyl adipate (3.460%), Calofort S (5.930%), Apyral 22 (6.120%) and Sphericel 110 P8 (19.3%) into the disperser type mixer together with usual additives such as surfactants, antifoam agents and pigments(1.28%). Start the mixer at a sufficient speed in order to wet out the powders sufficiently. 2. Aerosil R 8200 (1.986%) and Coathylene TB 2957 (5.930%) are then added and mixture mixed for a sufficient period of time to achieve an even dispersion. A vacuum is then applied and the formulation dispersed at high speed in order to achieve a homogeneous suspension. Garamite 1958 (2.960%) is then added, a vacuum applied and the mixture dispersed at high speed at a temperature in excess of 50° C. for a period of 20 minutes in order to achieve a homogeneous mixture The same general process was adopted for the manufacture of the reactive resin components in Formulations 2, 4 and 5 described below. The general process for the manufacture of hardener component of Formulation 1 in a disperser type mixer was as follows: 1. IP 262 (42.0%), Ruetasolv DI (3.0%), Apyral 22 (21.8%), Sphericel 110 P8 (23.0%) into the disperser type mixer together with usual additives such as surfactants and antifoam agents (1.9%). Start the mixer at a sufficient speed in order to wet out the powders sufficiently. A vacuum is then applied and the formulation dispersed at high speed in order to achieve a homogeneous suspension 2. Coathylene TB 2957 (5.8%) and Garamite 1958 (2.5%) were then added, a vacuum applied and the mixture dispersed at high speed at a temperature in excess of 50° C. for a period of 20 minutes in order to achieve a homogeneous mixture This general procedure was also adopted in the manufacture of the reactive hardener component in Formulations 2, 4 and 5. The general procedure for the manufacture of the reactive resin component in Formulation 3 in a planetary type mixer was as follows: 1. Charge Araldite GY260 (46.0%), Araldite GY 281 (6.0%), Araldite DY H/BD (3.76%), Dioctyl adipate (2.0%), Apyral 22 (11.48%) Cretafine N100 (10.8%), Q Cel 5028 (14.9%) and other minor ingredients such as surfactants, antifoam agents and pigments (2.3%) into a planetary type mixer. Start the mixer at a sufficient speed in order to wet out the powders sufficiently. Apply a vacuum and mix at a sufficient speed to in order to obtain a homogeneous mixture. 2. Charge Garamite 1958 (2.76%) and start the mixer at a sufficient mix in order disperse this material evenly within the mixture. Apply a vacuum and mix this formulation at sufficient speed at a temperature above 30° C. for a period time in excess of 15 minutes. The general procedure for the manufacture of the reactive hardener component in Formulation 3 in a planetary type mixer was as follows: 1. Charge Jeffamine D 230 ( 38%), Accelerator 399 (0.5%), Ruetasolv DI (4.0%), Cretafine N100 (22.50%), Apyral 22 (14.0%), Q Cel 5028 (14.7%) and other minor ingredients (0.3%) into a planetary type mixer. Start the mixer at a sufficient speed in order to wet out the powders sufficiently. Apply a vacuum and mix at a sufficient speed to in order to obtain a homogeneous mixture. 2. Charge Aerosil R 8200 (2.0%) and Garamite 1958 (4.0%) and then start the mixer at a sufficient mix in order to disperse this material evenly within the mixture. Apply a vacuum and mix this formulation at sufficient speed at a temperature above 40° C. for a period time in excess of 15 minutes. Table 2 shows the compositions of the two components of Formulations 1 to 3: TABLE 2 Formulation 1 Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 39.520 IP 262 Adduct 42.000 Araldite GY 281 11.530 Sphericel 110 P8 23.000 Dioctyl Adipate 3.460 Apyral 22 21.800 Araldite DY H/BD 1.980 Coathylene TB 2957 5.800 Apyral 22 6.120 Ruetasolv DI 3.000 Sphericel 110 P8 19.30 Garamite 1958 2.500 Coathylene TB 2957 5.930 Additives 1.900 Calofort S 5.930 Garamite 1958 2.960 Aerosil R 8200 1.986 Additives 1.284 TABLE 3 Formulation 2 Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 40.000 IP 271 Adduct 39.000 Araldite GY 281 10.000 Sphericel 110 P8 15.000 Dioctyl Adipate 3.500 Apyral 22 23.248 Araldite DY H/BD 2.000 Coathylene TB 2957 6.000 Apyral 22 10.000 Ruetasolv DI 4.000 Sphericel 110 P8 14.800 Garamite 1958 2.000 Coathylene TB 2957 6.500 Calofort S 8.600 Calofort S 6.000 Other minor 2.152 Garamite 1958 2.500 ingredients Aerosil R 8200 2.000 Other minor 2.700 ingredients TABLE 4 Formulation 3 Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 46.000 Jeffamine D 230 38.000 Araldite GY 281 6.000 Accelerator 399 0.500 Dioctyl Adipate 2.000 Apyral 22 14.000 Araldite DY H/BD 3.760 Cretafine N 100 22.500 Apyral 22 11.480 Q Cel 5028 14.700 Q Cel 5028 14.900 Ruetasolv DI 4.000 Cretafine N 100 10.800 Aerosil R 8200 2.000 Garamite 1958 2.760 Garamite 1958 4.000 Other minor 2.300 Other minor 0.300 ingredients ingredients Evaluation of Formulations The pastes are evaluated as follows. 1. The slump resistance of the paste is measured immediately after mixing and prior to curing The curing takes place immediately on mixing and is not delayed. The thixotropic nature of the paste is immediately observed whilst being dispensed. The paste was dispensed utilising Tarder Nodopox machinery at a thickness of 10-50 mm horizontally onto a vertical surface. This method allows evaluation of the degree of sag visually at different application thicknesses. The thickness of the strips of paste are measured using a ruler. If the shape of the strips starts to distort and move down the vertical surface onto which they are applied then the material is effectively slumping. Table 6 gives values of slump resistance measured. 2. The density is measured at 23° C. in accordance with ISO 1183. 3. The viscosities (i.e. dynamic viscosities) of the individual components of the reactive resin and the hardener and the mixture of the two were measured at 25° C. using a TA Instruments Rheometer AR 2000. An internal test method is used to measure the viscosity at a frequency of 0.01593 Hz, geometry 2 cm diameter serrated plate (formulations 1-5, 21-23). In the case of formulations 6-20 a 2 cm diameter 2° cone and plate geometry was used. The shear rate was then increased in a continuous ramp from 1 Hz to 50 Hz over a period of one minute. 4. Linear shrinkage is measured by dispensing the mixed paste from the Tartler Nodopx into a mould with the dimensions of 1000×60×40 mm. The degree of shrinkage is recorded after 7 days curing at room temperature. 5. The Shore D hardness is measured on the cured samples in accordance with ISO 868. Table 5 shows the viscosity values of the components and the mixed resin of Formulations 1 to 3; where more than one value was taken, the range of the measured values is shown in Table 5: The below mentioned viscosities are expressed in Pa·s units. Viscosity can also be expressed in kPa or in cP units, with 1 kPa s=1 cP=1000 Pa s. To make it clear, the viscosity value of, for example, the reactive resin component of Formulation 1 is 135,000 Pa s which means 135 000 Pa s and corresponds to 135 kPa s and to 135 cP. In the below examples, when the viscosity value contains a significant centime part it shall be mentioned for example as 56.08 Pa s. TABLE 5 Viscosity measurements of individual and mixed components Formulation 1 Formulation 2 Formulation 3 Viscosity @ Viscosity @ Viscosity @ 0.01593 Hz 0.01593 Hz 0.01593 Hz (Pa · S) (Pa · S) (Pa · S) Reactive resin 135,000  56,500-106,100 3,074-7,890 component Reactive 12,830 27,000-49,850 17,490 hardener component Mixed 301,800 338,000-342,000 235,500-265,000 components As clearly seen, the viscosity of the mixed resin is substantially greater than that of either of the component parts. Table 6 sets out the physical properties of thixotropic seamless modelling pastes of Formulations 1 to 3 TABLE 6 Physical properties of thixotropic seamless modelling pastes Physical Properties Formulation 1 Formulation 2 Formulation 3 Density 1.2/1.17 1.24/1.25 0.88/0.87 Consistency Thixotropic Thixotropic Thixotropic paste paste paste Slump resistance >40 mm 40 mm 30 mm Cracks None None None Shore D Hardness 75 78 75-77 (Fully cured) Linear shrinkage 1 mm 0.5 mm 1 mm 1000 mm length, 40 mm thickness Comparative Formulations 4 and 5 Formulations 4 and 5, which are comparable to Formulations 1 to 3, were made but one did not include the platelet filler (Garamite) in the epoxy resin component and Formulation 5 did not include the platelet filler (Garamite) in either component. Tables 7 and 8 set out the compositions of these Formulations: TABLE 7 Formulation 4 (no platelet filler in epoxy resin component) Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 42.000 IP 262 Adduct 42.000 Araldite GY 281 10.500 Sphericel 110 P8 23.000 Dioctyl Adipate 3.500 Apyral 22 21.800 Araldite DY H/BD 2.800 Coathylene TB 2957 5.800 Snowcal 40 9.670 Ruetasolv DI 3.000 Sphericel 110 P8 11.600 Garamite 1958 2.500 Coathylene TB 2957 5.830 Other minor 1.9% Calofort S 5.000 ingredients Bentone SD-2 2.500 Aerosil R 8200 2.000 Aerosil R 202 3.500 Other minor 1.1 ingredients TABLE 8 Formulation 5 (no platelet filler in either component) Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 42.000 IP 262 Adduct 46.000 Araldite GY 281 10.500 Sphericel 110 P8 14.000 Dioctyl Adipate 3.500 Apyral 33 12.200 Araldite DY H/BD 2.800 Coathylene TB 2957 4.000 Snowcal 40 9.660 Airflo CC 9.000 Sphericel 110 P8 10.600 Aerosil R 202 4.000 Coathylene TB 2957 5.000 Aerosil R 8200 4.500 Calofort S 5.000 Ruetasolv DI 5.6 Bentone SD-2 3.000 Other minor 1.2 Aerosil R 8200 2.500 ingredients Aerosil R 202 4.300 Other minor 1.14 ingredients Table 9 shows the viscosity values of the components and the mixed resin of Formulations 4 and 5; where more than one value was taken, the range of the measured values is shown in Table 9 TABLE 9 Viscosity measurements of Formulations 4 and 5 stored at room temperature Formulation 4 Formulation 5 Viscosity @ Viscosity @ 0.01593 Hz (Pa · S) 0.01593 Hz (Pa · S) Reactive resin 313,500-315,700 553,100-582,600 component Reactive hardener 14,980-25,220 2,951-5,974 component Mixed components  38,880-197,700 113,100-205,600 Table 9 shows a drop in viscosity on mixing. Table 9 clearly shows that the increased viscosity values shown in Table 5 are not due to partial curing of the Formulations. Table 10 shows the physical properties of Formulations 4 and 5 following mixing: TABLE 10 Physical properties Physical Properties Formulation 4 Formulation 5 Density 1.26/1.17 1.24/nd Consistency Thixotropic Thixotropic paste paste Slump resistance >30 mm 40 mm Cracks None None Shore D Hardness 75 n/d (Fully cured) Linear shrinkage 1 mm n/d 1000 mm length, 40 mm thickness This effect of heightened thixotropy when combining the individual reactive resin and reactive hardener component is only noted when Garamite 1958 (alkyl quaternary ammonium clay) is present in both components (see Formulation 4 where only one of these components i.e. the hardener contains Garamite). In Formulation 4, the reactive epoxy resin component contains two silica based thixotropes possessing various siloxane and silanol groups on the surface. A third Theological agent (Bentone SD-2) is also present and is classified as an organic derivative of a montmorillonite clay When combined using the standard mixing and dispersing method the resultant paste does not exhibited a viscosity significantly higher than that of both individual components. Formulation 4 is similar in nature to Formulation 1. The slump resistance in Formulation 4 is lower than that Formulation 1 which concurs with a lower mixed viscosity. In the case of Formulation 5, the reactive epoxy resin component again contains two silica based thixotropes possessing various siloxane and silanol groups on the surface along with an organic derivative of a montmorillonite clay (Bentone SD-2). The hardener constituent contains only two silica based thixotropes and hence no clay based thixotrope was present in this component. The reactive epoxy resin component used in Formulation 5 had a higher viscosity than the reactive epoxy resin component used in Formulation 4. However, when combined with the hardener component, Formulation 5 shows a reduction in the viscosity of the mixed system in relation to that of the individual reactive resin component of 60%. Formulation 5 is therefore another example where the absence of a particular type of clay material in both the reactive resin and hardener components does not initiate an increase in viscosity of the mixed system in relation to the viscosity of the individual reactive components. Formulations 6 to 14 Formulations 6 to 14 are adhesive compositions. As set out in Table 11, Formulations 6 to 8, each contained a component of a two-part curable resin, i.e. either a resin (Araldite GY260) or a hardener for the resin (Aradur 140 or TEPA). Component Formulations 9 to 14 also contained an alkyl quaternary ammonium clay (Garamite 1958). Formulations 6 to 14 were prepared by mixing the raw materials by hand at room temperature under ambient conditions until a homogeneous composition was obtained. Each resin composition was made in an amount of approximately 100 g and each hardener composition in an amount of approximately 50 g. TABLE 11 Chemical composition Component Quantity of Formulation Quantity of Quantity of Quantity of Garamite No GY 260 (%) Aradur 140 (%) TEPA (%) 1958 (%) 6 100 7 100 8 100 9 98 2 10 98 2 11 98 2 12 96 4 13 96 4 14 96 4 The viscosity of Component Formulations 6 to 14 was measured using the procedures outlined above using a shear frequency of 4 Hz and the results are set out in Table 12. TABLE 12 Viscosity of individual and mixed component formulations Component Formulation No Viscosity at 4 Hz (Pa · s) 6 12.13 7 21.05 8 0.18 9 16.79 10 24.19 11 0.21 12 25.93 13 37.77 14 0.55 Component Formulations 6 to 14 were mixed together by hand in the proportions set out in Table 13 to form curable compositions containing one resin Component Formulation (6, 9 or 12) and one hardener Component Formulation (7, 8, 10, 11, 13 or 14). The viscosity of each curable composition was measured immediately after mixing using the procedures outlined above but with a shear frequency of 4 Hz and the results are set out in Table 13. TABLE 13 Ratio of Resin Component Formulation (6, 9 or 12) Viscosity of to Hardener Component Formulation mixed components Formulation (7, 8, 10, 11, 13 or 14) at 4 Hz (Pa · s) 6 + 7 100:65 14.15 6 + 8 100:14 4.351  9 + 10 100:65 21.23  9 + 11 100:14 6.114 12 + 13 100:65 37.29 12 + 14 100:14 16.61 Component Formulations 15 to 20 As set out in Table 14, Component Formulations 15 to 20 each contained a component of a two-part curable resin, i.e. either a resin (Araldite GY260) or a hardener for the resin (Aradur 140 or TEPA). All Component Formulations also contained an alkyl quaternary ammonium clay (Garamite 1958) and fillers (Apyral 22, Calofort S and Sphericel 110 P8) TABLE 14 Quantity (%) Component Formulation No 15 16 17 18 19 20 Tetraethylene pentamine 67.2 65.2 Aradur 140 67.2 65.2 Araldite GY 260 67.2 65.2 Garamite 1958 2 4 2 4 2 4 Apyral 22 10 10 10 10 10 10 Calofort S 6 6 6 6 6 6 Sphericel 110 P8 14.8 14.8 14.8 14.8 14.8 14.8 The viscosities of the individual component formulations and mixtures of the formulations, as set out in Table 15 were measure using the procedure set out above at a shear frequency of 4 Hz. TABLE 15 Viscosity of individual and mixed components Ratio of Resin Component Formulation (19 or 20) to Hardener Viscosity at Formulation Component Formulation (15 to 18) 4 Hz (Pa · s) 15 2.975 16 13.94 17 53.37 18 80.66 19 42.38 20 51.05 19 + 15 100:14 16.51 19 + 17 100:14 61.76 20 + 16 100:65 41.19 20 + 18 100:65 124.7 The introduction of clay in the form of Garamite 1958 (concentration of 2 to 4%) into the reactive resin (formulation 6) and hardener components (formulation 7 and 8) increased the viscosity of these individual components (see Table 12). This would be expected due to the platelet like structure of the clay. Similarly, the viscosity of the reactive resin and hardener components containing nanoclay was higher than the viscosity of the mixed reactive resin and hardener constituents without nanoclays (see formulation 6+7 and 6+8 compared with 9+10 and 9+11 in Table 13). The use of nanoclay and additional fillers that interact with the nanoclay (Apyral 22, Calofort S and Sphericel 110 P8), increases the viscosity of the individual resin and hardener components (Table 15, Formulation 15-20) compared to the corresponding formulations without the additional fillers, i.e. containing, as fillers, solely the clay constituent (Table 12 formulations 9-14). However, the viscosity of a mixture of the resin and hardener components that each contain both nanoclay and the additional fillers showed an unexpected increase as compared to the viscosity recorded for individual resin and hardener components, see the combination of (a) formulations 17 and 19 and (b) formulations 18 and 20 (Table 15). This is principally the same effect observed for formulations 1, 2 and 3. Formulation 21 (Epoxy-amine Resin with Cloisite® Platelets) Experimental Procedure General Process for the manufacture of formulation 21 resin component using a disperser and planetary type mixer 1. Charge Araldite GY260 (46.0%), Araldite GY 281 (6.0%), Araldite DY HIBD (3.76%), Dioctyl adipate (2.0%) into container. Disperse using a Disparmat for five minutes at 1000 min −1 . Charge Apyral 22 (11.48%) Cretafine N100 (10.8%), Q Cel 5028 (14.9%), Cloisite 25 Å (2.76%) and other minor ingredients (2.3%) into a container and disperse for 15 minutes @ 2000 min −1 . 2. Mix was then transferred to a planetary type mixer. A vacuum was applied and mixed at sufficient speed at 50° C. for twenty minutes to in order to obtain a homogeneous mixture. General procedure for the manufacture of the reactive hardener component in formulation 21 using a disperser and planetary type mixer 1. Charge Jeffamine D 230 (37.53%), Accelerator 399 (0.49 %) and Ruetasolv DI (3.95%) into a container. Disperse using a Disparmat for five minutes at 1000 min −1 . Charge Cretafine N100 (22.21%), Apyral 22 (13.83%), Q Cel 5028 (14.55%), Cloisite 25 Å (3.95%) and other minor ingredients (0.3%) into a container and disperse for 15 minutes @ 2000 min −1 . 2. Mix was then transferred to a planetary type mixer. A. vacuum was applied and mixed at sufficient speed at 50° C. for twenty minutes to in order to obtain a homogeneous mixture. Formulation 22 The sane experimental procedure was used to produce Formulation 22 TABLE 16 Formulation 21 Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 46.0 Jeffamine D230 37.53 Araldite GY 281 6.0 Accelerator 399 0.49 Dioctyl Adipate 2.0 Apyral 22 13.83 Araldite DY H/BD 3.76 Cretafine N100 22.21 Apyral 22 11.48 Q Cel 5028 14.55 Cretafine N 100 10.8 Ruetasolv DI 3.95 Q Cel 5028 14.90 Aerosil R8200 1.7 Cloisite 25 Å 2.76 Cloisite 25 Å 3.95 PJ 755 2.0 Aerosil R202 1.49 Byk 065 0.3 Byk 065 0.3 TABLE 17 Formulation 22 Quantity Quantity Resin Composition (%) wt Hardener Composition (%) wt Araldite GY 260 46.0 Jeffamine D230 37.53 Araldite GY 281 6.0 Accelerator 399 0.49 Dioctyl Adipate 2.0 Apyral 22 13.83 Araldite DY H/BD 3.76 Cretafine N100 22.21 Apyral 22 11.48 Q Cel 5028 14.55 Cretafine N 100 10.8 Ruetasolv DI 3.95 Q Cel 5028 14.90 Aerosil R8200 1.7 Cloisite 25 Å 2.76 Cloisite 93 Å 3.95 PJ 755 2.0 Aerosil R202 1.49 Byk 065 0.3 Byk 065 0.3 TABLE 18 Viscosity measurement Formulation 21 Formulation 22 Viscosity @ Viscosity @ 0.01593 Hz (Pa · S) 0.01593 Hz (Pa · S) Reactive resin 3,455 56.08 component Reactive hardener 566.1 359.1 component Mixed components 4040 1072 Formulation 23 (Polyurethane Example) Experimental Procedure General Process for the manufacture of formulation 23 isocyanate component using a planetary type mixer 1. Charge Suprasec 2211(78.6%) and Additive TI (1%) into a container. Disperse under vacuum for twenty minutes. 2. Charge Airflo CC (9.06%), Cretafine N100 (7.780%), Garamite 1958 (3.0%) and other minor ingredients (0.3%) into the container and mix for sixty minutes under vacuum at 80° C. Allow to cool to room temperature and transfer to storage jars General procedure for the manufacture of the polyol component in formulation 23 using a disperser and planetary type mixer 1. Charge Polyol PP50 (36.0%), Poly G85-29 (2.0%), 1,4 Butanediol (8.0%) and Ruetasolv DI into a container. Disperse under vacuum for twenty minutes. 2. Charge Cretafine N100 (16.5%), Airilo CC (12.0%), HXA6 (12.0%) and, Garamite 1958 (3.95%) into a container and mix for 60 minutes under vacuum at 80° C. 3. The mix was allowed to cool to room temperature and Baylith L (5.0%) charged into the vessel. A vacuum was applied and mixed at sufficient speed for twenty minutes to in order to obtain a homogeneous mixture. TABLE 19 Formulation 23 Isocyanate Quantity Quantity Composition (%) wt Polyol Composition (%) wt Suprasec 2211 78.86 Polyol PP50 36.0 Additive TI 1.0 Poly G85-29 2.0 Garamite 1958 3.0 1,4 Butanediol 8.0 Byk 054 0.3 Aerosil R 8200 1.0 Airflo CC 9.06 Garamite 1958 2.5 Cretafine N100 7.780 HXA6 12.0 Ruetasolv DI 5.0 Airflo CC 12.0 Cretafine N100 16.5 Baylith L Powder 5.0 TABLE 20 Viscosity measurement for formulation 23 Formulation 23 Viscosity @ 0.01593 Hz (Pa · S) Reactive resin component 248.4 Reactive hardener component 522.8 Mixed components 1375

A two component reactive composition is described. Each component, before they are mixed together, contains a filler having thin platelet structure, e.g. a nanoclay, and a further filler that interacts with the platelets. The individual components can have a filler loading that makes them flowable and therefore the components can readily be mixed together for ready dispensing. When the components are mixed thoroughly together, the resulting resin may have a viscosity higher than that of the individual components. The loading of the filler is preferably chosen so that the resulting blended resin is capable of being applied on to a vertical surface without experiencing significant slump. The viscosity of the mixed material can be up to 5 to 10 times or more than that of the individual components before mixing. The composition can be used in adhesives, modelling pastes, coatings, sealants, putties, mastics, stopping compounds, caulking materials, encapsulants and surface coatings, e.g. paints.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a competitive game of skill requiring an increasingly high degree of hand-eye coordination, and more particularly to such game where any number of a plurality of balls are in action at any one time, being received and returned by a pair of opponents. 2. Prior Art Heretofore competitive ball and paddle games have been proposed. For example, hockey type games are proposed in U.S. Pat. Nos. 3,785,648 and 4,261,568, and a croquet game apparatus is disclosed in U.S. Pat. No. 5,029,863. These games are played on a horizontal surface. U.S. Pat. No. 4,343,470 discloses a ball rolling game including an inclined ramp centered over a divided catching field with divisions of the field into which the balls fall having various point values. Further, U.S. Pat. No. 3,907,294 discloses a competitive projectile game having a totally enclosed inclined playing surface wherein a single reboundable ball is launched toward and rebounded from a flexible rebound barrier toward an opposing player using a block like paddle. SUMMARY OF THE INVENTION The skill game includes paddle members used to maneuver any desired number of a plurality of reboundable balls from one opponent toward another opponent with the playing surface being inclined toward adjacent play stations at a lower open end of the surface. Each opponent has one set of up to four or more balls, depending on the desired level of difficulty, and any number of balls may be sequentially launched upon the playing surface and simultaneously played. Play begins when one or both opponents launch a first ball and ceases when either opponent allows a ball to escape the playing surface. DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of the game of the present invention showing two balls in play upon a playing surface of the game. FIG. 2 is a cross sectional side view through the game of FIG. 1 and shows one ball captured within a blind pouch at a lower end of the game. FIG. 3 is an enlarged perspective view of one paddle of the game. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in greater detail, there is illustrated therein the competitive skill game of the present invention generally identified by the reference numeral 10 . As shown, the game 10 includes an inclined rectangular playing surface 12 which is framed along two elongate sides 14 and an upper end 16 which intersects both sides 14 by an upstanding wall 18 . An unframed lower end 20 is open and is divided into two playing stations 22 by means of a centered dividing wall 24 which extends from open end 20 substantially over half way across the surface 12 toward the upper end 16 . At each corner 26 defined at each intersection of the upper end 16 with the sides 14 , an upstanding barrier 28 is provided which angles across the corner 26 at approximately 45° to the corner 26 . Depending from and fixed to the unframed lower end 20 and extending thereacross is a blind pouch 30 which descends a short distance from the end 20 and then folds back upwardly and outwardly over itself to a predetermined level above the playing surface 12 and is further fixed to free ends 32 of the upstanding wall 18 and centered dividing wall 24 aligned along open end 20 . Each opponent is provided with a paddle 34 , a number of balls 36 designated for a particular level of difficulty, and a glove 38 for protecting an opponent's playing hand. It is preferable to use the glove 38 because the balls 36 are weighty, being similar in weight and size to croquet balls, and further because play is close to the playing surface 12 , with the glove 38 protecting the opponent's hand from contact scrapes. The paddles 34 are themselves rather weighty and are shaped to resemble miniature bowling pins, with a larger ball engaging base 40 extending into a narrower graspable neck portion 42 . If desired, the neck portion 42 may be covered with a frictional strip 44 for secure gripping and may further include a strap 46 fixed along the neck portion 42 , with the glove 38 sliding between the neck portion 42 and the strap 46 for enhanced grasping security, as best illustrated in FIG. 3 . In play, as shown is FIG. 1, either one or both opponents begin the game by launching a ball 36 toward upper end 16 from one playing station 22 in a manner to rebound the ball 36 toward the opponent's playing station 22 . Thus, upstanding wall 18 acts not only to contain the balls 36 upon the playing surface 12 but serves as a primary barrier against which launched balls 36 may be rebounded. Further, each corner barrier 28 may also be used for ball 36 rebound, and is positioned to create an angulation to the rebound path, as shown in FIG. 1, in phantom. Because the playing surface 12 is downwardly inclined toward the playing stations 22 , as best illustrated is FIG. 2, a ball 36 in play will not lose speed as it rebounds toward the playing station 22 to which it is directed and, if launched with sufficient force, will even gain speed after rebounding, as it rolls downwardly, adding a further dimension of challenge to play of the game 10 . It will be understood that anywhere from one to eight (or more) balls 36 may be in play at any given time, based on the desired level of difficulty, with balls 36 being added or launched as either opponent may choose. Play continues as long as all balls 36 launched remain on the playing surface 12 . If a ball 36 escapes the playing surface 12 , it drops and is collected into the blind pouch 30 , as shown. Because of the weightiness of the balls 36 , and the speed at which they travel, the pouch 30 has been configured as described above to assure that a ball 36 does not contact the body of an opponent standing along the end 20 . To allow for ease of removal of the balls 36 from pouch 30 , attachment thereof to the aligned free ends of wall 18 and divider 24 is created using deformable member 48 such as a spring or heavy section of elastic. It will be understood that the deformable member 48 should be elevated above the playing surface 12 sufficiently to assure that a ball 36 cannot escape thereover, as best illustrated in FIG. 2 . It will be seen further that each play station 22 of the playing surface 12 may be provided with a foul line 50 , if desired, which defines an area beyond which paddle 34 engagement of the ball 36 by an opponent is not allowed. The foul line 50 is particularly useful in creating an “equalization” of play in an instance where an adult is competing with a child, so that the adult cannot have an advantage of extended reach over that of the child. As described above, the skill game 10 of the present invention has a number of advantages, some of which have been described above and other of which are inherent on the invention. Also, modifications may be proposed to the skill game 10 without departing from the teachings herein. Accordingly, the scope of the invention should only be limited as necessitated by the accompanying claims.

The competitive skill game includes a playing surface upon which any number of a plurality reboundable balls are launched toward and away from a barrier, toward an opponent who attempts a return through use of a paddle, the number of balls in simultaneous play being determined by the desired degree of difficulty for the game.

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus having a plurality of interchangeable activity centers, such as puzzles, games, or moving parts, for promoting child activity or for use as a therapy tool. BACKGROUND OF THE INVENTION [0002] Parents today have a great variety of toys they can purchase for their children. One of the factors parents may consider when deciding what toy to buy is how long their children may play with the toy before losing interest in it. Another factor parents may consider is whether the toy will help in the development of their children's motor skills or learning ability. Recognizing the importance parents place on these factors, toy manufacturers are constantly working to develop new toys that are either fun to play with or help in childhood development, or both. [0003] However, since every child has his own unique combination of physical and mental development, personality, and interests, he is prone to quickly lose interest in any one toy for a variety of reasons. For instance, some children may have less fun with a toy once they understand how it works. As its operation or outcome becomes routine or well understood, the toy no longer presents a challenge or holds excitement for the child. One example of this tapering of interest is with puzzles. Once a child understands the “secret” of a puzzle and has mastered its solution (i.e., the child is both capable of understanding the secret and also has developed sufficient motor skills to perform tasks associated with the secret), the level of continued interest in the toy can drop significantly. [0004] Conversely, some toys may have features that are too complicated for a child, and therefore also may not be as fun, educational, or helpful in child development. With each unsuccessful attempt to make a toy work, frustration levels may build until some children ultimately give up trying to play with the toy. Similarly, there may be an aspect or feature of a toy that frightens a child. Thus, some children may not enjoy or maintain interest in a toy because of an aspect or feature that is not well-matched to the child's interests, capabilities, or sensitivity. [0005] In many cases there are several aspects of a toy that are well-matched to a child's interests and capabilities, while only a small portion or element may be too difficult, complex, or perhaps frightening. For instance, a toy having an element or feature requiring a certain level of fine motor skills may not be interesting to a child who has not yet developed the necessary skills to competently manipulate its parts. Similarly, a toy having a feature requiring memorization of a series of steps before proceeding may present too much of a challenge for some children. Unfortunately, once a child loses interest in a toy it is difficult to generate renewed interest in it later on, even though the child may have subsequently developed the skills needed to enjoy its more difficult or complicated features. SUMMARY OF THE INVENTION [0006] The present invention allows for a device (such as a child's toy or a therapy aid) to be custom-tailored to a user's interests and capabilities by utilizing interchangeable activity centers having a variety of themes, complexity, or content. A parent, therapist, or other person can select and combine activity centers according to a user's interests or developmental needs. [0007] One embodiment of the present invention relates to a first plurality of activity centers having a variety of themes, complexity, or content. The activity centers have front and rear surfaces and at least one contact surface. In addition, a base unit may be used to join two or more of the activity centers together. As needed, a parent, physician, user, or other person may later substitute, remove, or rearrange any or a subset of the activity centers. [0008] Without being bound to a particular theory, it is believed, that the ability to make adjustments to the collection of activity centers allows for better enjoyment of the toy or therapy device and better development by the user. In one embodiment, the activity centers are directed toward developing gross motor skills. Some activity centers may be made of a plurality of subcomponents or objects that can be selectively disassembled and reassembled. In some instances a predetermined sequence of manipulations of the objects or components is required in order to successfully disassemble or reassemble the parts. In an exemplary embodiment, an activity board having multiple objects or components also has a removable cover. Removal of the cover, however, may also require a predetermined sequence of steps, such as by first removing a second object associated with the activity center. [0009] The activity centers may be arranged and connected in several different ways. In one embodiment, the activity centers are arranged in a grid to form an activity board. Alternatively, the activity centers may be arranged in a stack where the front surfaces face in a common direction in a manner similar to a traditional book or magazine layout. In yet another embodiment, the activity centers may be connected in an accordion fashion where the connected activity centers may be connected side by side in a linear fashion. When folded in a zig zag or accordion manner, the front surfaces of the connected activity centers will alternate in the directions they face. [0010] The connecting surfaces of the activity centers may have magnetic material, metallic material, a hook and loop configuration, Velcro, ball and socket, notch and groove, or other suitable ways for selectively connecting activity centers together. [0011] In other embodiments of the invention, one or more of the activity centers may have a lockable cover panel. For instance, the cover panel further includes at least part of a latch, a combination lock, a chain lock, a deadbolt lock, or a sliding rod lock. In some embodiments, the content of one or more activity centers is directed toward reading development. [0012] In other embodiments, the plurality of connected activity centers forms a story. As the need or desire to change the story arises, one or more activity centers from a second plurality of activity centers may replace one or more of the first plurality of activity centers to change the content. [0013] The present invention also may be useful as an occupational therapy tool. In one embodiment, a first plurality of activity centers having a variety of themes, complexity, or content is once again provided. The activity centers may have two or more contact surfaces and may be joined together in a variety of ways. [0014] These and other advantages of the present invention will be clarified in the Detailed Description of the Invention taken together with the attached drawings in which like reference numerals represent like elements throughout. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 illustrates an embodiment of an activity center of the present invention where the activity center involves an assembly of objects; [0016] FIG. 2 illustrates the embodiment of FIG. 1 where the objects of the activity center are disassembled; [0017] FIG. 3 illustrates another embodiment of an activity center of the present invention where the activity center involves a puzzle involving a sequence of movements; [0018] FIG. 4 illustrates a variation of the embodiment of FIG. 3 where the sequence of movements involved translating an object across a surface of the activity center; [0019] FIG. 5 illustrates an embodiment of an activity center of the present invention where the activity center involves a rotatable and sliding lock; [0020] FIG. 6 is another embodiment of the invention where the activity center involves a puzzle involving a sequence of movements in order to unlock a cover; [0021] FIG. 7 is an embodiment of the present invention where an activity center has a sliding lock; [0022] FIG. 8 illustrates an embodiment of the present invention where an activity center has a plurality of interconnected gears that may be rotated by a user; [0023] FIG. 9 is an embodiment of the present invention where a spring-loaded cover is connected to an activity center; [0024] FIG. 10 is an embodiment of the present invention where an activity center has a plurality of latches for locking a cover in a closed position; [0025] FIG. 11 is an embodiment of the present invention where a cover is held in a closed position against an activity center with a spring-loaded magnet; [0026] FIG. 12 illustrates an embodiment of the present invention where an activity center is unlocked by manipulating one or more slideable objects; [0027] FIG. 13 illustrates embodiments of the present invention using a strap and lock to hold a cover in a closed position; [0028] FIG. 14 is an embodiment of the present invention where an activity center has multiple objects nested within each other; [0029] FIG. 15 is a variation of the embodiment of FIG. 14 where the objects are assembled according to a predetermined orientation or sequence; [0030] FIG. 16 illustrates an embodiment of an activity center of the present invention where the activity involves learning numbers; [0031] FIG. 17 illustrates an embodiment of an activity center of the present invention where the activity involves solving mathematical equations; [0032] FIG. 18 illustrates an embodiment of an activity center of the present invention where a plurality of activity centers form a story; [0033] FIG. 19 shows an embodiment where activity centers are connected along alternating sides or edges; and [0034] FIG. 20 shows an embodiment where activity centers are connected in a grid-pattern. DETAILED DESCRIPTION OF THE INVENTION [0035] As discussed above, the present invention uses interchangeable activity centers having a variety of themes, complexity, or content. Parents, therapists, users, or other persons can select, combine, and arrange two or more activity centers according to the user's interests and capabilities at that time. As the user develops greater skills or begins to lose interest, one or more of the activity centers may be removed, rearranged or substituted for one or more other activity centers. In this manner, a parent, therapist, or other person may maintain or renew interest in the toy or therapy device and continuously custom-tailor it for the user's changing interests, capabilities, or physical or mental development. [0036] Activity centers may be designed to serve particular interests of a user, to help in certain types of development, or to serve as an occupational therapy tool. For instance, an activity center may have one or more puzzles that require manual operation in order to open a window or screen on the center. Opening the window or screen may in turn reveal an image, provide access to a chamber within the activity center, play a sound or turn on a light when opened, or do another similar activity. In other words, a reward of some type may or may not be provided for solving the puzzle on the activity center. In another embodiment, the activity center may be formed of a plurality of objects that can be assembled or disassembled when properly arranged, or alternatively when arranged according to a particular sequence. [0037] Many different types of puzzles may be provided on activity centers. For instance, each activity center may be an individual toy having a button, switch, latch, door, or similar device that a user may enjoy playing. One example of a puzzle illustrated in FIGS. 1 and 2 is an activity center 20 having multiple objects or components 22 that can be assembled and disassembled. As illustrated, disassembly of the activity center 20 may involve removing the objects 22 in a particular sequence, such as by first removing the star-shaped object 24 before other objects can be removed from the activity center. Once the star-shaped object 24 is removed, a cover panel 26 may then be removed from the activity center 20 by sliding it in a predetermined direction. Removal of the cover panel 26 may then reveal additional objects 22 inside the activity center 20 that also may be removed, or alternatively may allow viewing of an image or hearing of a sound, or may reward the user in some other way. [0038] In is contemplated that the activity (game, puzzle, challenge, task, etc.) of an activity center may be attached to the center. However, in an exemplary embodiment, the activity is integrated into the center, i.e. the activity is built into the center. While the components and objects of the activity center may be disassembled and removed from the center during use, it should be understood that the components and objects become integrated into the center when the center is in an assembled state prior to and after a user plays with the activity center. [0039] Other puzzles may be directed toward manipulating an object or feature of an object associated with an activity center according to a predetermined sequence. FIG. 3 , for example, illustrates an activity center 20 having a cover 26 with a rotatable dial 28 on its face. When the dial 28 is properly manipulated according to a predefined sequence of steps, the cover 26 can be opened to reveal the contents of the activity center 20 . In this embodiment, the dial 28 may first be rotated to a first position, whereupon it may be pulled outward or pressed inward a predefined distance. Once the dial 28 is moved inward or outward, it may again be rotated until it reaches a second position and moved inward or outward once again. These steps may be repeated until eventually the dial 28 reaches a final position where the cover 26 is unlocked and may be opened to reveal the contents of the activity center 20 . As shown, the cover panel 26 may be rotatably connected to the activity center 20 along one side. [0040] While the combination of rotation and inward or outward displacement described above is illustrative, it should be understood that other sequences and types of movement or manipulation of objects also could be used. One example of a variation is illustrated in FIG. 4 , where a dial 28 may be configured on an activity center 20 such that when it is rotated to a first position it can be translated from one location on the activity center 20 to another location. For example, once the dial 28 is in a first position, it may be capable of being slid to a second location or position through a channel or other translational throughway 30 formed in a portion of the activity center, such as the cover 26 . This can be achieved, for instance, by configuring the dial 28 to have parallel edges that can be aligned to slideably engage with a channel or throughway 30 in the activity center 20 . [0041] Other types of puzzles or locks of varying complexity and operation also may be provided on an activity center. For example, a cover 26 may be selectably locked to an activity center 20 with a rotatable and slidable lock 34 as illustrated in FIG. 5 , while FIG. 6 shows a chain lock 36 where one end of the chain 38 is directly or indirectly connected to a cover panel 26 and a second end of the chain 40 can be slideably engaged with a recess and channel 42 formed on the activity center 20 . FIG. 7 shows another variation of a puzzle or lock on an activity center 20 . The puzzle or lock uses a sliding bar or rod 44 that can be moved from a first, locked position to a second, unlocked position. [0042] Some puzzles or toys, such as illustrated in FIG. 8 , may involve rotating one or more gears 46 that can be rotated or turned by a user. In an exemplary embodiment, a plurality of gears 46 are provided so that rotation of one gear causes one or more other gears to also rotate. The gears 46 may have different diameter sizes so that they have different rates of angular rotation. In these embodiments, the activity center may be configured with a transparent or translucent window that allows a user to witness the interaction of two or more gears 46 while also protecting a user from being pinched or otherwise hurt by the rotating gear teeth. [0043] As mentioned above, a child or other user who succeeds at solving the puzzle or lock may be rewarded in many ways for their effort. In one embodiment shown in FIG. 9 , solving the puzzle or lock causes the cover panel 26 to rapidly spring open. One way this can be accomplished is to provide spring-loaded hinges 50 . FIG. 9 also shows that one or more latches 52 may be used to selectively lock the cover 26 to the activity center 20 . As shown, two or more sides or edges of the cover 26 may be configured with latches 52 . Operation of the latches can be similar to operation of window locking devices. A raised, curved surface of a pivoted or rotatable first component of the latch 52 can be selectively engaged with a channel or recess in a second component of the latch 52 . One component is connected to a surface of the activity center while the other component is connected to the cover 26 . In this manner, when the two components are engaged they prevent the cover 26 from being opened. FIG. 9 shows three edges of the cover 26 being configured with latches 52 . [0044] It should be understood that some or all of the features, components or configurations of one embodiment may be used in combination with or as a substitute for one or more features, components or configurations of another embodiment. In FIG. 10 , for instance, the activity center 20 has three sliding locks 34 in a configuration similar to that of FIG. 9 . Skilled artisans would appreciate that many other combinations and substitutions are possible without departing from the spirit and scope of the invention. [0045] In another embodiment, illustrated in FIG. 11 , the lock or latch may be spring loaded so that an edge or side of the cover 26 rapidly moves away from the activity center 20 . In yet another embodiment, other edges or surfaces of the activity center 20 may be compressed so that they apply a rapid opening force on the cover 26 when it is unlocked and released. The activity center 20 may be configured to also play a sound or song (or provide some other reward or stimulus) upon rapid opening of the cover 26 . [0046] Another variation of a puzzle is illustrated in FIG. 12 . In this embodiment, one or more interior panels or bars 58 may be moved from a first, locking position to a second, unlocked position. As shown in FIG. 12 , the cover 26 of the activity center 20 may be unlocked once the interior panels or bars 58 are properly arranged. If a more complex puzzle is desired using the features of this embodiment, the movement or positioning of the interior panels or bars 58 may require a proper sequence in order to successfully unlock the activity center 20 . In another alternative, movement of interior bars 58 may involve both translational movement as well as rotational movement. Even more complex puzzles may involve repositioning the interior panels or bars in a predetermined sequence. [0047] FIG. 13 shows that one or more straps 60 may be used to lock the activity center 20 . For example, a webbing or strap 60 may extend across two or more surfaces of the activity center 20 . One end 62 of the strap 60 may be connected to a cover 26 while the second end 64 may be connected to the activity center 20 , the cover 26 or to another webbing or strap 60 . Locking and release of the strap 60 may be accomplished by providing a locking clip. The locking clip may operate in any suitable manner, and may involve a variety of ways of releasing or unlocking, some being relatively easy while others being significantly more complex. [0048] Another type of puzzle that may be provided in an activity center is the use of one or more objects nested inside another object. Turning to FIGS. 14 and 15 , for example, the interior space of an activity center 20 may have an object inside it. In turn, this object may have a space or recess formed therein where another object is located. Thus, FIG. 14 shows that one puzzle that may be provided by an activity center 20 may be as simple as a box 66 within a box 68 . A more complex variation of this type of puzzle is illustrated in FIG. 15 , which shows that the rearrangement of objects may require a particular orientation and sequence of assembly. The activity center may also include latches, locks, gears, boxes in boxes, and runners 70 , or similar device, for sliding boxes into and out of other boxes. [0049] Some puzzles may be directed toward learning to identify numbers or to applying numbers in mathematics, others may involve moving or positioning one or more physical elements or combining structural elements together in a particular way, while others may be directed toward learning geometric shapes. In addition, puzzles also may involve language learning, such as identifying letters or phonetic symbols or sounds, forming words or sentences, applying grammatical rules, or learning other language building blocks. [0050] One example of a mathematical puzzle, illustrated in FIG. 16 , may be to associate an ordering of numbers or symbols with one or more buttons, dials or indicators 72 on the cover 26 or other surface of the activity center. One number or symbol 74 may be associated with each button so that a user pressing the buttons in the correct order will unlock a window or screen formed in the center or otherwise be rewarded for correctly identifying the ordering. The ordering may be sequential, such as numbers ordered from high to low or from low to high, or may be a predefined ordering. The ordering also may be changeable over time, such as by the parent, therapist, or user. Furthermore, the length of the sequence may vary from simple identification of a single number or symbol (i.e. asking the user to find the number “three”) to a more complex ordering of multiple numbers or symbols. [0051] Another example of a mathematical puzzle may be for the activity center to provide one or more mathematical equations and provide a corresponding correct answer among a plurality of choices. This embodiment is shown in FIG. 17 . Once again, a child or other user may be rewarded in some manner for correctly solving the mathematical equation. In one embodiment, shown in FIG. 17 , the input to the mathematical equation may be varied so that the user can be exposed to and learn to solve a variety of numerical combinations instead of simply memorizing the answer to one equation. As shown in FIG. 17 , one example of how this may be accomplished would be to provide a plurality of dials 76 that may be turned to designate different numerical inputs or mathematical functions. One skilled in the art having the benefit of this disclosure would appreciate that many other types of mathematical puzzles may be provided on an activity center. For instance, rather than using a mechanical combination or button, the activity center 20 may have one or more displays (or similarly audio outputs) that allow display of different numbers, values, or mathematical functions. [0052] Another example of a puzzle may be an exercise that involves a user using their motor skills to accomplish a task. For instance, a puzzle may involve moving, rotating, orienting, connecting, or removing one or more components from another component of a puzzle. For example, an activity center may have a keyhole and a key associated with it. Placement of the key in the keyhole and, optionally, rotation of the key may then unlock a window so that the user may open a window or screen, as described above, or otherwise be rewarded in some manner. In one embodiment, rotation of the key in the keyhole may cause the activity center to provide an audible reward, such as by creating one or more audible clicks as it is rotated or by playing a one or more musical notes. [0053] Other activity centers may involve placing objects having a predefined shape into receptacles on the center having a corresponding shape. For instance, the objects may have geometric shapes, such as triangles, squares, circles, stars, rectangles, parallelograms, or the like, and the center may have receptacles corresponding to the geometric shape. Alternatively, the objects may be combined together like a jigsaw puzzle to create an image. [0054] Activity centers also may be arranged to form all or part of a story. For instance, a center may introduce a character, story line, or concept in a way that allows for combinations with a plurality of other centers. As the story develops, different centers may be combined or rearranged so that the story can have different outcomes. For example, one center may end with a character getting a surprise that is revealed on a subsequent center. The subsequent center may be selected from a variety of different types of centers describing different types of surprises, such as birthday presents, a family member or friend visiting them, or the like. [0055] In another example, two or more centers may be interchanged with each other in a story to focus on one of a variety of related concepts. For example, the story may discuss colors, shapes, games, or the like that can be varied to maintain a reader's interest or to increase their exposure to related concepts in a familiar format. Thus, a story may have one or more centers describing the color red that may be interchanged with one or more centers describing the color blue, or centers describing triangles may be replaced by centers describing circles, squares, or other shapes. One or more centers also may focus on alphanumeric characters that can be arranged to spell words, names, addresses, phone numbers, or the like. Similarly, a plurality of centers may illustrate phonetic sounds that can be used and arranged in different ways to help learn to read and pronounce words, and a plurality of centers may illustrate words that can be arranged to form different sentences. [0056] As shown in FIG. 18 , a plurality of activity centers 20 on a related subject also may be provided to allow for variation in the level of difficulty of complexity of the topic. For instance, some puzzles may be targeted toward developing gross motor skills, while more complex ones may involve fine motor skills and the performance of a series of steps. An activity center having a puzzle on it may be replaced by an activity center having a similar, but more complex puzzle. For example, an activity center having a puzzle involving turning a dial to a number may be replaced with a center requiring a dial having a two-number combination sequence. Likewise, some story centers may introduce more complex concepts or use more challenging words for a related concept. As a user becomes more capable of understanding more complex topics, a familiar story line may be expanded to introduce them. [0057] The manner in which activity centers may be combined can be accomplished in several different ways. For instance, a plurality of centers may be connected along a common side or edge so that the centers can be stacked on top of each other and opened or explored in a manner similar to pages in a book. For example, a connecting side of an activity center may be configured with a hooked material on one side and looped material on the other so that as the centers are stacked so that the hooks and loops hold the centers together on a common side like a book. The connecting side of the activity centers may be flexible, hinged, or be configured with a living hinge so that a user may flip from one center to another more easily. In another embodiment, portions of the surface or edges of activity centers 20 may be magnetic. In yet another embodiment, edges or surfaces of two or more activity centers may be configured to enable them to be joined to form a hinge. As discussed elsewhere, the joining of a plurality of activity centers may be more easily facilitated through use of a base unit that connects or supports each of the activity centers. [0058] Activity centers may be of any shape or configuration. The activity centers may be generally cube shaped, prism shaped, rectangular solid shaped, triangle shaped, circular or disc shaped, sphere shaped, or any other polyhedron shape. In an exemplary embodiment, the activity centers are cubes or rectangular solids (a three dimensional object with a rectangular cross section). When activity centers are to be joined together to form an activity board, at least two centers may include edges that are compatible for joining or mating. For example, two cube shaped centers may be connected together by two similar contact surfaces. Similarly, a cube shaped center may be connected to a triangle shaped center. All the activity centers of an activity board may have the same shape or configuration. [0059] The activity centers 20 also may be connected on alternating, opposing sides as illustrated in FIG. 19 . This arrangement may permit the activity centers to be arranged side by side along a surface, such as a floor or table top. If the connecting sides are configured to be flexible as described above, then the centers may be folded back and forth over each other so that they are more compact. The centers also may be configured so that they can connect with more than two other centers, such as arrangement according to a grid, as shown in FIG. 20 . Such an arrangement or grid of activity centers forms an activity board 80 . An activity board may tell a story or provide for mathematics, music, spelling, or reading. FIGS. 18-20 are examples of activity boards. [0060] Connection of one activity center 20 to another may be accomplished in several different ways. For example, two activity centers 20 may be joined by abutting side edges or surfaces of the activity centers. As discussed above, activity centers 20 also may be joined by overlapping at least a portion of the upper or rear surfaces of an activity center 20 with at least part of a front or rear surface of a second activity center 20 . As mentioned above, at least part of an edge or surface of an activity center may be formed of magnetic material. The use of magnetic material also may be beneficial for attaching activity centers to other metallic surfaces, such as a refrigerator door. [0061] In another embodiment, the centers are not directly connected to each other, but instead are connected to a base unit. The base unit is sized to receive a plurality of activity centers and display them in a desired manner. For example, a base unit may form a portion of a spine of a book where two or more activity centers are stacked upon each other so that each center is analogous to a page of a book. When the activity centers are intended to be arranged in a grid-like pattern, the base unit may be a frame having a recess in which the activity centers reside. When the centers are arranged in a grid-like order with a base unit, the result of the collection of activity boards forms an activity board. [0062] One benefit of the present invention is that an activity center may be sold separately and then combined with others. This allows each activity center to be provided at a lower cost than a full replacement of a toy, book, or game. It also allows for greater flexibility in custom-tailoring the arrangement of activity centers to suit a user's interests or developmental capabilities. Moreover, a plurality of activity centers discussing particular themes or concepts may also be sold for use with other activity centers. For example, a package of activity centers may be created for colors, animal sounds, phonetic symbols, beginning reading words, introductions to numbers, mathematics, and the like. [0063] Similarly, it may be possible to buy add-on or replacement centers that correspond to a story. As shown in FIG. 18 , this would allow a story of familiar characters liked by a child or other reader to have a variety of story lines. Likewise, substitute activity centers may be provided with progressively more complex mathematics topics. For example, one activity center in a set may be directed simply toward learning to recognize numbers, while another center in the set may be directed toward addition of single-digit numbers. Other add-on or replacement centers may be directed toward gradually increasing the level of manual dexterity required in order to interact with the activity center. Thus, puzzle packs may have a variety of easy to more complex puzzles or locks, and word packs may gradually introduce new words to a reader's vocabulary. [0064] It is also contemplated that the present invention may include a timing device associated with the puzzles, games, or moving parts of the activity centers. The timing device may include an audible or visual means for indicating when time is up. A parent, teacher, or other person may set the timing device for a specific period of time in which the user is expected to complete the task or tasks of one or more activity centers. The timing device may provide for more advanced skills development of the user. [0065] The various features of the invention have been described primarily in relation to a toy for education or entertainment. However, it will be appreciated that any of the features, such as the base unit and interchangeable activity centers, can be used on a therapy treatment device for users of all ages. Moreover, the features described are not limited to use only with the devices described herein. Thus, while the embodiments and variations described herein are illustrative of the invention, skilled artisans having the benefit of this disclosure would recognize many additional variations and modifications that do not depart from the scope of the invention. For example, a plurality of activity centers may be arranged or combined to form a game board on which players may play a game together. Using the concepts discussed above to this example, a skilled artisan would understand that one or more of the activity centers forming the game board may be interchangeable with other activity centers, thereby allowing the play of the game to be varied by the players.

The present invention provides interchangeable activity centers having a variety of themes, complexity, or content. Parents, teachers, therapists, or others can select, combine, and arrange two or more activity centers according to a user's interests and capabilities at that time. As the user develops greater skills or begins to lose interest, one or more of the activity centers may be removed, rearranged, or substituted for one or more other activity centers. This may lead to longer interest in the device and better correlate its subject matter with information or materials needed for further development.

BACKGROUND OF THE INVENTION This invention relates to the field of electrical power generation, more particularly to the field of power generation using compressed gas storage wherein turbulent gas flow is used to provide more energy efficient storage of compressed gas by reducing the energy gradient inherent to viscous flow. In the field of electrical power generation, electricity is produced in a variety of ways. Where major demands for electricity exist in a metropolis or other community, large baseload electrical generation facilities are used to generate the electricity. These baseload facilities are often large installations, such as nuclear power plants or coal powered electric plants, costing millions of dollars to construct and being relatively permanent once constructed. Although planning and forecasting go into selecting a site for such a baseload facility, unforeseeable changes in demographics and demand for electricity occur. Such changes can render a baseload facility distant from where the facility's power is needed most. Furthermore, due to safety concerns and political obstacles, it may not be feasible to locate a baseload facility close to a dense urban area or industrial area needing electricity the most. This is especially true when the baseload facility is a nuclear power plant. Also, if a city has a power failure, it may have to transmit power in from a neighboring city. Thus, in a power shortage emergency, the electricity transmitted in to alleviate the problem originates from a baseload facility far from the power failure. Significant line losses occur from this long-distance transmission of power. The power industry has approached this problem by transforming the voltage of electricity generated by the baseload facility to high voltages, and transmitting the high voltage electricity along transmission lines to where the power is needed. In this way, a baseload facility may be located in a suitable location and the power transmitted across the countryside to its ultimate use. High voltages are used in transmission since they result in less wasted energy in the form of line loss than do lower voltage transmissions of the same wattage. However, line losses do occur at the higher voltages, leading to a decay of transmission efficiency over long distances. In order to step up or increase the dropped voltage during transmission, it is often required that the transmission lines be routed to connect with other baseload facilities which will step up the voltage. Such routing may be less than optimal since the step up baseload facility may be located away from the most direct path between the transmitting baseload facility and the end use of the power. Such limitations in power generation and transmission facilities often become most evident during peak demand periods of the day. These peak demands for electricity typically occur during business hours in business and industrial areas of a community; but the peak demand can shift to outlying residential areas in the evening hours. When electricity demand peaks, the strain on the electrical power system can be great, even leading to blackouts or brownouts. Also, peak demand periods can cause overall system voltage and current drops. These drops can lead to decreased operating efficiency of equipment, such as electric motors and computers designed to operate at a fixed voltage. Other problems from these drops include a need for increased size of protective equipment in the transmission and distribution network, increased transformer KVA ratings, and increased magnetism effects within the transmission conductor. In addition to shifting peaking demands for electricity, a community may grow, increasing the total demand for electricity. Again, the effects of such demand are greatest during peak demand hours. A community could be faced with the dilemma of choosing between restricting community growth, or constructing additional costly baseload power facilities. The latter would require additional power generation facilities to increase baseload capacity, and additional power transmission facilities to increase transmission load carrying capacity. The present invention affords a community the option of avoiding the capital expense of constructing additional baseload power plants and/or constructing large transmission capacity power lines. Prior approaches use various means for electrical power generation during peak electricity demand periods known as compressed air energy storage, or CAES systems. One such means is disclosed by U.S. Pat. No. 4,275,310 to Summers and Longardner, showing a peak power generation process in which steam turbines drive air compressors which compress air to be stored in underground geological formations. During peak electricity demand periods, the compressed air is used to drive turbines which turn electric generators. U.S. Pat. No. 4,237,692 to Ahrens and Kartsounes discloses a compressed air energy system for electrical power generation. The compressed gas is stored in one of the "four types of underground reservoirs that are suitable for the storage of compressed air. They are: depleted petroleum fields, aquifers, mined rock cavities, and solution-mined salt cavities." Ahrens, Col. 2, lines 1-4. Other systems are disclosed in U.S. Pat. Nos. 3,597,621, 3,988,897, and 4,443,707. In the field of compressed gas storage, various arrangements of nesting tanks in parallel arrangement have been used in non-CAES related applications. One such arrangement is illustrated in Hill, U.S. Pat. No. 3,847,173. However, typical gas storage systems lead to energy inefficiencies. When a compressed gas is being pumped into the storage tank, it encounters resident gas in the tank. Resident gas, a relatively still body of gas already in the tank, acts somewhat like a wall, against which newly entering compressed gas is recompressed. Likewise, the resident gas is recompressed. This recompression inside the storage tank causes localized temperature rises in the gas due to the work of recompression done on the gases. Such temperature rises cause a higher temperature differential between the gas and the surrounding environment, thus causing greater heat loss to the surrounding environment. This heat energy loss leads to energy inefficiencies in the overall gas compression and storage system. The prior system, as seen in Hobson, U.S. Pat. No. 4,150,547, has indirectly addressed this problem by surrounding the gas storage vessel with thermal insulation in order to slow the heat transfer to the surrounding environment. The present invention improves the efficiency of gas compression and storage systems by reducing heat loss to the surrounding environment. Heat loss is reduced by reducing localized temperature rises in the gas storage tanks. This is achieved by introducing a turbulent flow of gas through the storage tanks during the time the tanks are being filled. This turbulent flow is achieved by bleeding or circulating a portion of the compressed gas out of the tank while the tank is being filled. The result is a turbulent flow of gas through the tank during filling which mixes gas in the tank. This mixing of gas causes heat of recompression and other heat energy to be more evenly distributed throughout the tank. Although the net heat energy in the tank remains approximately the same due to the circulating, localized temperature rises, or hotspots, are reduced or eliminated. As such, localized regions of heat transfer to the surounding environment are reduced, thus decreasing energy loss from the system. Furthermore, heat exchangers may be used to cool the circulating gas during filling of the tanks. Under certain conditions, savings in lost energy are greater when the gas is not stored for long time periods. Over long time periods, assuming the environment surrounding the storage tank is cooler than the compressed gas, heat energy will be lost to the environment. This is true even if turbulent flow in the tank evenly distributes the heat energy in the tank. However, evenly distributed heat energy will lead to a lower temperature differential with the environment at localized hot spots. A lower temperature differential will result in a slower rate of heat loss to the environment. Thus, the present invention is especially suitable to take advantage of this slowed rate of heat loss. The present invention has particularly good application in the area of compressed air energy systems used for peak period electrical energy generation where storage periods are typically less than twenty-four hours. The compressed gas removed from the tank during filling is either circulated to the compressor train or bled for use elsewhere. When the gas is circulated, it is injected back into the compressor train which originally compressed the gas for storage. Typically, such circulated gas is injected into a low or intermediate pressure compressor stage in a multi-stage compressor train. The circulated gas is then further compressed in a higher pressure stage of the multi-staged compressor and then pumped back into the tank. The present invention may, instead of circulating compressed gas back to the compressor train which originally compressed the gas, use the compressed gas elsewhere in another device requiring compressed gas. When the gas is bled for use elsewhere, the gas is employed in a means other than the original compressor train. Typically, this use is to drive a turbine engine or to be further compressed in a second compressor train distinct from the original compressor train. Furthermore, when such gas is used to drive a turbine engine, such turbine engine may be used to drive the original compressor train. Turbulent gas flow through the gas storage vessel is enhanced when the storage vessel comprises a plurality of elongated needle tanks connected in series, through which the compressed gas flows along a flow path. The gas is circulated or bled at the end of the flow path in the series of needle bottles. Another advantage of the present invention is that it provides an arrangement to reduce the dynamic shock on a gas storage system when highly compressed gas is introduced into the system. The shock created by introducing gases at pressures higher than residual pressure in the system at 2000 p.s.i. and greater can stress the joints, valves, and other parts of a compressed gas storage system. The present invention can help to relieve such stress on the system, prolonging system integrity. Although the series arranged tanks may be used in any variety of applications needing a supply of compressed gas, a preferred use of the present invention is to employ it in compressed air energy storage systems. Such systems can be used to supplement electrical power generation, especially during peak electric demand periods of the day. The present invention is an advance over the prior art in that it provides for increased power generation to boost a system's peak load capacity without having to increase the baseload capacity of the baseload electrical power generation facility and without having to increase the transmission load capacity of the transmission lines. The present invention also provides means for stepping up voltage to eliminate line loss occurring during power transmission. These and other advantages are accomplished by locating satellite power facilities on an electrical power grid and apart from a baseload facility. By selectively locating the satellite power facility near an area of peak electricity demand and by coordinating operation of the baseload facility and the satellite power facility in synchronization with the cycles of peak and non-peak electricity demand, the present invention can meet increases in peak electricity demand. Energy can be generated in the form of electricity, transmitted to the satellite power stations at non-peak electricity demand periods, such as the middle of the night, stored as potential energy at the satellite power stations in the form of compressed air in large needle tanks independent of geological formations, converted from compressed air back into electrical energy using a turbine engine driving a generator, and then distributed to electricity consumers closer to the satellite power station. In this way, energy can be transported or transmitted to outlying areas during the night when demand is low and the transmission lines have surplus load capacity. Also, many baseload facilities perform at optimal efficiency when they are operating close to capacity. Since many of the baseload facilities are not operated close to capacity during low demand periods, during such periods the opportunity to enjoy this optimal efficiency is lost. This is especially true of nuclear power plants. In the present invention, the satellite power facilities increase the demand for electricity during the night hours. Thus, during night operations (non-peak demand periods), since output is increased, greater efficiencies in operating the baseload facility are realized. The result is that the system begins the next peak period with efficiently generated surplus energy. Furthermore, the energy is already distributed across the grid network, ready and located to be utilized. Another advantage of the present invention is that electrical energy may be dispatched upon demand to offset peak loads that may spike the system, such as gas turbine starting packages, electric electrode furnaces or system outages due to apparatus failure. Another advantage of the present invention is that it may be used to replace or supplement power normally provided by equipment which is off-line for maintenance, repair or replacement. Another advantage of the present invention is that the satellite power facilities are much easier to locate in a given area than a baseload facility or a geologically dependent CAES system. Also, the satellite power facilities are virtually pollution free, pose no danger of nuclear meltdown and can occupy much less space than a baseload facility. Thus, it is easier to selectively deploy a satellite power facility near a high electricity demand area to boost peak power during peak demand periods. Also, due to the present invention's independence from geological formations, it is technologically feasible to locate a satellite facility almost anywhere. The benefits of the present invention are best realized when the geographic distance between baseload facility and satellite power facility is greater than about twenty statute miles. However, benefits of the present invention may also be realized using shorter distances. In addition to locating the satellite power facilities along a grid network of a community, satellite power stations may be located along a series of electrical transmission lines. As described above, surplus electrical energy generated during low demand periods can be used to recharge the compressed air storage tanks at the satellite power facility. During high or peak demand periods, the compressed air is used to generate secondary electrical energy. This energy is used to step up the voltage which is being transmitted along lines from a baseload facility. The primary electrical energy generated by the baseload facility is partially dissipated during transmission due to impedance in the transmission lines and equipment. Thus, the present invention boosts or steps up the dropped voltage and lagging current. This power factor management is especially useful where transmission distances are long, even reaching distances of twenty, fifty or even several hundred miles. By locating the satellite facility along the transmission lines where the current is lagging the voltage, the impedance in the line is reduced by using a synchronous alternator at the satellite facility to reduce or eliminate the lag. This results in the downsizing of apparatus and/or improving upon the efficiency of existing apparatus and lines, such as transformers, protective equipment, protective relays, capacitors, and electric motors. This allows transmission (and also distribution) voltages to be maintained without relying on transmission inter-ties or load shedding techniques. Also, when the current is out of phase with the voltage, this lag causes undue magnetism around the transmission lines. By reducing or eliminating this lag, the present invention reduces the adverse environmental effects caused by the magnetism. The present invention also provides a convenient means for conversion of alternating current to direct current or vice-versa. By using an alternating current motor to drive the air compressor, and by using a direct current generator, the CAES system of the present invention may be used to convert AC power to DC power. Conversely, the present invention may employ a direct current motor and an alternating current generator to convert DC power to AC power. SUMMARY OF THE INVENTION A compressed gas storage system according to one embodiment of the present invention comprising a gas storage circuit having means for storing compressed gas in the circuit and having an inlet through which the circuit is filled with gas; a first compressor located along the circuit and adpated and arranged to circulate compressed gas around the circuit. Accordingly, an object of the present invention is to provide an improved compressed gas system and method. These and other related objects and advantages of the present invention will be apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a satellite facility of the present invention. FIG. 2 is a partial schematic diagram of an alternative embodiment of a satellite facility of the present invention. FIG. 3 is a flow diagram of a viscous compressible fluid along a longitudinal cutaway of a cylindrical container along line 3--3 of FIG. 4. FIG. 4 is a flow diagram of a viscous compressible fluid along a cross-sectional cutaway of a cylindrical container along line 4--4 of FIG. 3. FIG. 5 is a schematic diagram of a second alternative embodiment of a satellite facility of the present invention. FIG. 6 is an aerial perspective view (not to scale) of one embodiment of the present invention. FIG. 7 is an aerial perspective view (not to scale) of an alternative embodiment of the present invention. FIG. 8 is a partial side view showing a typical underground storage tank and fittings of the present invention. FIG. 9 is a partial side sectional view of a typical storage tank of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Referring to FIG. 1, gas storage system 10 includes storage tanks 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h, 11i, 11j, 11k, 11m, 11n, 11p, 11q and 11r. Although the embodiment in FIG. 1 illustrates a gas storage system 10 having 16 storage tanks, the present invention may employ more or less storage tanks. The storage tanks are nested in four sets of four tanks. A set of tanks comprising tanks 11a-d are interconnected in series by tank connection lines 12a, 12b and 12c. This set of tanks and tank connection lines is in parallel with other sets of tanks and lines in series, such as tanks 11i, 11j, 11k, 11m, and lines 12g, 12h, and 12i. The other sets of tanks are connected in series by tank connection lines 12d, 12e, 12f, 12j, 12k and 12m. In the preferred embodiment, the tanks are large, measuring approximately 4 feet in cross sectional diameter and 40 to 1000 feet long, depending on site and design considerations. The tanks are constructed of a composite wrap martinsite steel produced by the Inland Steel Company, having headquarters in Chicago, Illinois. The composite wrap tanks are made in accordance with the disclosures in U.S. Pat. No. 3,880,195 to Goodrich and U.S. Pat. No. 3,378,360 to McFarland, both of which are hereby expressly incorporated by reference. The martinsite wrapping is 0.060 inches thick and 1.60 inches wide. The tanks are capped tubes, the caps being welded in place with a martinsite wrap along the seam (see FIG. 9). Gas to be stored enters the intake filter 13 and is typically air at ambient conditions. After the gas to be compressed enters the intake filter, it passes through the intake line 14 into the initial compression stage 15. The initial compression stage 15 is part of the overall compressor train also made up of the first compression stage 16, the second compression stage 17, the drive motor 18 and the drive shaft 19. The drive motor 18 in the preferred embodiment is an electric motor powered by electric power grid 20. However, drive motor 18 could comprise any means for delivering mechanical energy to be used by a compressor train including a steam turbine engine, a gas turbine engine, an internal combustion engine, or any equivalence thereto. In the initial compressor stage 15, there are compressors 21a, 21b, 21c and 21d. Each of these individual compressors 21a-d make the initial compression stage 15 a multi-stage compressor train in and of itself. First compression stage 16 includes compressors 21e and 21f. Compressors 21e and 21f make first compression stage 16 a multi-stage compressor train in and of itself. Second compression stage 17 includes compressors 21g and 21h and also make second compression stage 17 a multi-stage compressor train in and of itself. Compressors 21a-h typically are dynamic compressors, such as those manufactured by Ingersoll-Rand Corporation, and are coupled with drive shaft 19, which delivers rotary power from the drive motor. Compressors 21a-f are interconnected in series by interstage connector lines 22a, 22b, 22c, 22d and 22e, which couple the gas discharge of each compressor with the gas intake of the next compressor. Compressor 21f is connected to the second compression stage 17 in series by interstage connector line 22f, which branches in parallel to final compressor feed lines 23a and 23b. Final compressor feed lines 23a and 23b supply gas to compressors 21g and 21h, respectively. Thus, a gas to be compressed enters in the intake filter 13 to be compressed to progressively higher degrees of compression through a series of gas compressors 21a-h . Note that, although in the embodiment shown in FIG. 1, drive shaft 19 drives each of the compressors 21a-h, it is not essential to this invention that the compressors be driven by any singular drive motor 18 or drive shaft 19. Drive shaft 19 may be geared in different ratios (not shown) to couple the rotary action from the various compressors. Compressed gas flows out of compressors 21g and 21h through the second stage gas discharge lines 24a and 24b and into the injection line 25. Line 25 has heat exchanger 25a located therein to remove heat energy from the compressed gas coming out of the compressor train. Coolant supply line 25c provides a liquid coolant, water in the preferred embodiment, to the heat exchanger. The heat exchanger also acts to remove heat caused by recompression of gas in the storage tanks while they are being filled. This acts to cool the gas in storage, requiring less work to compress a given mass of gas into the tanks. The coolant is heated from the heat energy of the gas and then returned in the return line 25b to a heat removing device, such as absorption chiller 101, which uses the heat energy from return line 25b to provide refrigeration for use elsewhere. The absorption chiller is optional, but is believed to improve the performance of the present invention. This absorption chiller is commercially available from manufacturers, such as Trane air conditioning division of the Trane Company of La Crosse, Wis. This refrigeration may be used to pre-cool and dehumidify incoming gas in intake line 14, as well as to inter-cool compressed gas flowing through interstage connector lines 22a-f. This precooling and intercooling with chillant from an absorption chiller occurs using heat exchangers, such as heat exchanger 25a, along the lines 14 and 22a-f. Use of such absorption chiller is also disclosed in my pending U.S. Patent application Ser. No. 915,791, and is hereby incorporated by reference. The chillant system includes the absorption chiller, as well as chillant supply lines 103 and 105, and chillant return lines 107 and 109. The supply and return lines supply, in parallel, a flow of water coolant to pre-cooler 111, and to inter-coolers 113, 115, 117, 119, 121 and 123. Alternatively, cooling from an evaporative cooling source, such as a cooling tower, may be provided. The pre-cooler and inter-coolers are heat exchangers, similar to heat exchanger 25a, and cool the gas flow through the system. Parallel supply and return branches (as shown in FIG. 1) connect these heat exchangers with the coolant supply and return lines. Compressed gas from the injection line 25 flows into the compressed gas storage system 10 for storage. Typically, such gas is stored during low electricity demand periods to later be used during high electricity demand periods. Pressure in the injection line 25 can reach 2,000 p.s.i. and higher, and enter the compressed gas storage system at a temperature ranging from 60° F. to 150° F., with an optimum temperature believed to be about 85° F. As the compressed gas travels through injection line 25, valves 26a and 26b are open to allow the compressed gas to flow through inlet lines 27a, 27b, 27c and 27d. The compressed gas flows from inlet line 27a into gas storage tank 11n through inlet 28a. Compressed gas flows from inlet line 27b into gas storage tank 11e through inlet 28b. Compressed gas flows from inlet line 27c into tank 11i through inlet 28c. Compressed gas flows from inlet line 27d into tank 11a through inlet 28d. As discussed above, FIG. 1 illustrates four sets of four tanks nested together and connected in series. The set consisting of tanks 11a-d are used to describe the flow of compressed gas through a series of tanks. The description of flow through tanks 11a-d is substantially the same as in the other three sets of four tanks 11e-h. 11i-m and 11n-r and is not repeated for each set of tanks. Rather the description of flow through tanks 11a-d is incorporated as applying to the other three sets of four tanks. In tank 11a, the compressed gas enters at inlet 28d. Tank outlet 29a is an opening through which the compressed air entering through inlet 28d may exit tank 11a. Thus, the compressed gas flows through tank 11a along a flow path (not shown). This flow is turbulent in nature, causing a mixing of the gases in tank 11a. Note however, the flow rate through outlet 29a is less than the flow rate through inlet 28d. Thus, a pressure differential or pressure gradient is developed between inlet line 27d and tank connection line 12a. Furthermore, due to the flow rate differential between inlet 28d and outlet 29a, compressed gas accumulates in tank 11a, thus filling it with compressed gas. After leaving outlet 29a, the compressed gas passes through tank connection line 12a and through inlet 28e into tank 11b. Again, turbulent flow of the gas through tank 11b is achieved. Again, also, there is a pressure differential between tank connection line 12a and tank connection line 12b. The gas continues to flow in series through outlet 29b into tank connection line 12b and into tank 11c by way of inlet 28f. The gas flows through tank 11c through outlet 29c into tank connection line 12c. Expansion valve 30a is located along tank connection line 12c to restrict the flow of compressed gas through tank connection line 12c. Note that expansion valves 30b, 30c and 30d perform similar functions along their respective tank connection lines. Expansion valves 30a-d include orifices to restrict the flow of compressed gas through the tank connection lines. These orifices are typically fixed. Typically, the orifices are standard off-the-shelf fixed orifices such as ones available from Fisher & Porter Company of Warminster, Pennsylvania. Note that in the preferred embodiment, the orifices are of decreasing size along the flow path of the compressed gas through the series of tanks, helping to create a pressure gradient along the series of tanks. Furthermore, expansion valves, such as 30a, and/or orifices may be located along any of the several tank connection lines 12a-m and may include flow meters and/or pressure meters. The compressed gas flows from tank connection line 12c through inlet 28g into tank 11d. After turbulent flow through tank 11d, the gas exits at outlet 29d into gas exit line 31a. Note that in the series of tanks 11a, 11b, 11c, and 11d, tank 11a constitutes an intake tank and tank 11d constitutes a discharge tank. Tanks, such as tank 11a are, in the preferred embodiment, elongated needle tanks. Due to the tanks elongation, they have longitudinal ends opposite of each other, such as the ends of tank 11a shown near inlet 28d and outlet 29a. Gas exit lines 31b, 31c and 31d perform substantially the same function as gas exit line 31a. The gas in gas exit line 31a combines with the gas in gas exit line 31d and passes through exit valve 32a. Note that gas exit valve 32b performs substantially the same function as gas exit valve 32a, that is, to provide a valve to shut off or restrict flow exiting from the gas exit lines 31a-d. The gas flowing through exit valves 32a and 32b flows into the compressed gas return line 33. Check valve 34 is located along compressed gas return line 33 and check valve 34 is oriented so as to allow the flow of compressed gas away from the compressed gas storage system 10, but not to allow a flow of compressed gas toward the compressed gas storage system. The gas in the compressed gas return line flows into the circulation valve 35. In the embodiment shown in FIG. 1, the circulation valve 35 is a three-way valve allowing a flow of compressed gas to be shut off, or to flow from compressed gas return line 33 into the circulation line 36, or to allow gas flow from the compressed gas return line into the turbine train line 37. The compressed gas flowing in the circulation line 36 is at a lower pressure than the compressed gas flowing in the compressed gas supply line 25 due to the pressure drop gradient across the series of tanks, tank connection lines, and orifices in the compressed gas storage system. Three-way valve 49 is opened to allow the compressed gas in the circulation line 36 to enter the first compression stage 16. Circulation line 36 is coupled with the interstage connector line 22e. The three-way valve 49, in this mode, prevents compressed gas from flowing into secondary line 50. In this way, the compressed gas in circulation line may be combined with compressed gas traveling in series along compressors 21a-h at a point in the compressor series having a comparable pressure to the gas pressure in the circulation line. Thus, reverse flow in the circulation line 36 is reduced or eliminated by the positive pressure head. The compressed gas from the circulation line, which combines with the gas in interstage connector line 22e, is further compressed in compressors 21f, and 21h or 21g. From that point, the compressed gas resumes the previously disclosed circuit in the compressed gas storage system. This circulating circuit between the compressor train (initial compression stage 15, first compression stage 16, and second compression stage 17) and the compressed gas storage system 10 creates a dynamic cycle of flowing compressed gas while compressed gas is being filled in the gas storage tanks 11a-r. In the inventor's best mode, it is believed that the disclosed system performs optimally when the ratios of mass flow rates between the compressed gas supply line 25 and the compressed gas return line 33 is approximately 10:1 during initial stages of filling the storage tanks, and progressively moves to approximately 100:1 during the final stages of filling. Alternatively to flowing the compressed gas in to interstage connection line 22e, the compressed gas may be routed into interstage connection line 22f by way of secondary circulation line 51 by opening valve 52. In this way, the compressed gas may be circulated into a higher pressure compression stage as the pressure in compressed gas storage system 10 increases above the pressure in interstage connection line 22e. Similarly, gas recirculated from the storage means can be routed through secondary circulation lines 131, 133, 135 or 137, respectively, as the pressure in storage means increases during filling. Each of these four optional lines includes a valve, similar to valve 52, to allow progressive opening and closing of the secondary circulation lines as the pressure in the storage means increases. Also, the compressor train may be by-passed by routing the compressed gas through secondary line 50 by closing off the portion of line 36 downstream of valve 49 and opening a flow path to line 50. In this way, compressed gas is communicated directly back to compressed gas storage system 10, by-passing the compressor train. This allows the gas storage system to achieve pressure equilibrium more rapidly. Note that in FIG. 1, the arrows in the compressed gas flowlines indicate the direction of compressed gas flow during operation of the system of the present invention. An alternative summary of the gas flow cycle is as follows. After compressed gas flows through compressors 21a-e, the gas enters a circuit. The circuit is a series of compressors, lines, valves and tanks, around which some or all of the compressed gas will flow during filling of the circuit. The circuit is filled with compressed gas at an inlet formed by the junction of interstage connector line 22e and circulation line 36. The circuit continues into compressor 21f, and then around through lines 22f, 23a, 23b, compressors 21h and 21g, lines 24a, 24b, 25, gas storage system 10, line 33, valves 34, 35 and 36, and then back to line 36. The portion of the circuit within gas storage system 10 follows the pattern described above, with several subcircuits in parallel with each other as defined by the four paths through the four sets of four tanks. Heat exchanger 25a serves to cool gas flowing through the circuit, removing heat due to compression in the compressor train and due to recompression in the tanks. The circuit may be routed through line 51 by opening valves 49 and 52 accordingly. Such rerouting of the circuit is done as the pressure in the gas storage system increases. Earlier in the filling cycle, lines 131, 133, 135 and 137 may be progressively opened and closed as the pressure in the system increases. In addition to or alternatively to allowing the compressed gas to flow through circulation line 36, the compressed gas may be flowed through the circulation valve 35 to the turbine train line 37. The compressed gas flows from turbine train line 37 into turbo-expander 38 which converts the potential energy in the compressed gas into rotary mechanical energy by expanding the compressed gas across turbine blades (not shown). The compressed gas then flows through the interturbine connector line 39 and into combustion chamber 40. The compressed gas is mixed with combustible fuel from fuel tank 41 in the combustion chamber 40 where it is combusted. The fuel is delivered from fuel tank 41 through fuel line 42 having fuel valve 43 to regulate fuel flow. The fuel is typically natural gas or other fuels, such as JP-4 jet fuel. The combusted fuel and compressed gas in the combustion chamber 40 drives the combustion turbine 44, creating further rotary mechanical energy. The combustion turbine is preferably a 501-T3B gas turbine engine offered by Allison Gas Turbine Operations Division of General Motors Corporation, of Indianapolis, Ind. Drive shaft 45 is driven by both the turbo-expander 38 and combustion turbine 44. Drive shaft 45 may be geared in different ratios (not shown) to couple the rotary action from turbo-expander 38 and combustion turbine 44. Drive shaft 45 in turn drives electromagnetic generator 46 which generates electricity transmitted across electrical power grid 47. Exhaust gases from the combustion turbine 44 are discharged to the atmosphere through the exhaust discharge 48, or routed to chiller 101 for producing refrigeration. This refrigeration may be stored as ice or a chilled water sink to augment the management of refrigerant during the operation of the system. The generation is typically operated at peak electrical power demand periods to supplement energy requirements. Referring now to FIG. 2, an alternative embodiment of a portion of the present invention is shown. The storage system 210 is a best mode alternative layout to storage system 10 shown in FIG. 1; and is considered the best made for such storage system. Most notably, gas storage tanks 211a-j are in axial alignment with a corresponding gas storage tank. This is primarily to offset mechanical stresses and strains in the tanks and the lines connecting the tanks due to forces acting on and in the tanks. This axial alignment will help to reduce manifold forces from damaging the gas storage system. For example, tank 211a is axially aligned and oppositely disposed from tank 211f. Likewise, tank 211b is opposite of tank 211g and so forth. Compressed gas is provided to the gas storage system from injection line 25 and travels through valve 226 into injection lines 227 and 231. The gas flow rate through lines 231 and 227 are substantially equal and in opposite directions. Note that tanks 211a-e have a tank length 233, and tanks 211f-j have a tank length 229. Tank lengths 233 and 229 are substantially equal, thus giving symmetric and equal pipe and tank lengths across which flow induced friction will result. Since the lengths are substantially equal, the frictional forces are substantially equal. Since the forces are substantially equal and in an opposite direction, they will effectively offset each other. Gas flows from line 227 into tank 211j. Note that backflow is prevented in line 227 by check valve 234a. Likewise, check valve 234b prevents backflow towards injection line 25. Compressed gas flows from tank 211j into lines 235 and 239 and then into either or both of lines 241 and 243. From line 241, the compressed gas flows into tank 211i and into line 245. Line 245 contains orifice 247a, which is a standard off-the-shelf orifice, and/or flow meter substantially similar to expansion valve and/or orifice 30a shown in FIG. 1. The gas then flows into tank 211h and then into lines 251 and 255. Next, the gas flows into either or both of lines 257 and 259, gas from line 257 flowing into tank 211g. Gas is communicated from tank 211g to tank 211f through line 261. Line 261 includes orifice 247b which is substantially similar to orifices 247a, 247c and 247d. Compressed gas then exits tank 211f through line 265 and into line 269. The compressed gas in line 269 flows through valve 232 when such valve is open and exits the gas storage system 210 at which point line 269 becomes compressed gas return line 33, as shown in FIG. 1 The flow path of compressed gas through tanks 211f-j is essentially the mirror image of the flow path of gas through tanks 211a-e. The description of the flow path through tanks 211a-e is not repeated, other than to state that the compressed gas flows through lines 231, 237, 239, 243 and/or 241, 249, 253, 255, 259 and/or 257, 263, 267, 269, and through tanks 211a-e, and through orifices 247c and 247d, as shown by the flow arrows in FIG. 2. The manifold forces which potentially cause damage in the piping and manifolds and tanks of the present invention primarily originate from several sources, such as viscosity strains, forces due to momentum change, forces due to friction, and forces due to air pressure. By axially aligning the tanks and lines as illustrated in FIG. 2, eccentricity is minimized in the tank and line structures, reducing the bending stresses in such equipment. Instead, for example, lines 241 and 243 are in axial tension during portions of the compressed gas filling phase of the present invention, due to the symmetric and axial alignment of tanks 211d and 211i. Similarly, lines 253 and 251 are axially aligned and positioned to exert compressional forces offsetting one another. Referring now to FIGS. 3 and 4, theoretical flow diagrams of viscous compressible fluids are shown. FIG. 3 illustrates a typical cross-section along a gas storage tank, such as tank 11a. FIG. 4 shows a cross-section as seen as line 4--4 of FIG. 3. In FIG. 3, the flow direction is indicated by the "FLOW" arrow, with a datum pressure of P a . The parabolic profile seen in FIG. 3 between P b and P c corresponds to the pressure gradient existing in a dynamic flow state across the diameter of the storage tank 311. Outer laminar layer 312 is adjacent to tank 311 and is the laminar layer in which the friction, due to laminar adhesion, is the greatest. Conversely, the centerline flow in tank 311 is the theoretical area of lowest friction. As seen in the point indicated S=0, the centerline flow has a shearing stress of 0 at the centerline of flow. The shearing stress increases closer to the wall of tank 311 until the point of maximum shear, S=Max, is reached at the tank wall. FIG. 4 illustrates annular laminar zones, such as laminar layer 312. As one moves from the center of tank 311 radially outwards along the tank radius T, the stress gets greater, as seen by incremental stress dY. Shear stress increases along shear gradient Y. Along the interior of tank 311 at the very boundary layer, the compressed gas remains essentially fixed by adhesion. The present invention introduces turbulence in tank 311, thus disrupting the laminar flow as depicted in FIGS. 3 and 4. Referring now to FIG. 5, tanks 511a and 511b are elongated needle tanks connected in a circuit 599, which includes the tanks and lines 531, 527b, 525d, 527a and 512. Compressor 521a, which is driven by motor 518a and drive shaft 519a, is connected in series on circuit 599. Compressor 521a acts as a circulatory pump, circulating compressed gas in the circuit 599. This creates the turbulent flow necessary to reduce hotspots from occurring in tanks 511a and 511b due to recompression. Compressed air is introduced into circuit 599 through injection line 525, which is coupled with tank 511b at inlet 528a. Ambient air enters intake filter 513 and flows through line 514 into gas compressor 521. Gas compressor 521 is driven by motor 518 and drive shaft 519. Gas compressor 521 increases the pressure of the gas to flow through injector line 525. Valve 526 enables the operator to close injection line 525 to prevent backflow escape of compressed air out of the circuit 599 during storage phases. When compressed gas is to be used, valve 535 is opened, allowing the compressed gas in the circuit 599 to flow through compressed gas return line 533 to be used in compressed gas device 538. Most typically, compressed gas device 538 consists of a turbo expander used to generate electrical power. However, compressed gas may also be used for pneumatic tools, gas turbines, or any other use of compressed gas. Heat energy is removed from circuit 599 through heat exchanger 525a. The head exchanger surrounds line 525d with a coolant supplied from coolant supply line 525c. The coolant is typically water, which removes heat in the heat exchanger, and then flows through coolant return line 525b to a cooling device (not shown). Heat exchanger 525a and compressor 521a are typically operated simultaneously with the operation of compressor 521. In this way, the temperature of the compressed gas in the circuit 599 may be lowered during the filling phase of the circuit. Once the circuit, including tanks 511a and 511b, is sufficiently filled with compressed gas at the desired temperature and pressure, compressors 521 and 521a are shut down, valves 526 and 535 are closed, and the coolant is no longer circulated through heat exchanger 525a. In this storage mode, compressed gas is on hand to be used in the compressed gas consumption device 538. Tank 511a has inlet 528a and outlet 529a. Tank 511b has inlets 528a and 528c, and outlets 529b and 529c. These inlets and outlets communicate the tanks with the corresponding gas lines seen in FIG. 5. Referring now to FIG. 6, like FIG. 7, FIG. 6 is a perspective diagrammatic illustration of the present invention drawn to illustrate the spacial interrelationships of the various aspects of the present invention. FIG. 6 is not drawn to scale. FIG. 6 shows an arrangement in which baseload electrical generation facility 612 is connected to electricity consumer 618 by way of transmission lines, such as transmission wires 614. Baseload electrical generation facility 612 can comprise a coal powered electric plant, a nuclear power plant having a nuclear reactor, a hydroelectric generation facility or any other facility suitable for producing large quantities of electrical energy for consumption. The baseload electrical generation facility is located a distance apart from electricity consumer 618, both of which are located on geographic area 611. This distance may be as small as a few miles, or as large as several hundred miles, even crossing state lines. Remote power facility 613, as shown, is a simplified illustration of the system as disclosed in FIGS. 1, 2 or 5 in its environment of preferred use. Facility 613 is located between baseload electrical generation facility 612 and electricity consumer 618 along the transmission wires. The satellite power facility is electrically conductively connected to the transmission wires at the satellite-transmission interface 629. The transmission wires 614 are typically strung along transmission towers, such as transmission tower 615, but may also be strung in underground conduits or other means of traversing distances (not shown). The satellite transmission interface is the junction of conductive wires from the satellite power facility to the transmission wires. This involves transforming secondary electrical energy generated at the satellite power facility to a higher voltage using transformers (not shown). In the term "secondary electrical energy", the adjective "secondary" indicates that its source of origin is from a satellite power facility. The satellite power facility has an electric motor 620, which drives an air compressor 621 by way of a drive shaft 622. Compressed air is pumped from air compressors 621 and 621a into air storage tanks 623 for storage. Air from air tanks 623 is combined with fuel from fuel tank 624. This compressed air and fuel mixture is combusted in a combustion chamber (not shown) in turbine engine 630, which drives electromagnetic generator 627. Turbine engine 630 has a combustion chamber within it and turbine engine 630 is interchangeable with a system, as disclosed in FIG. 7, having combustion chamber 25 and turbine 26 separate. Either embodiment will work with the present invention. Flow of compresed gas from air compressor 621 to air storage tanks 623 is regulated by valve 628. Valve 628 may be subsequently opened to allow flow of compressed gas from air storage tanks 623 into turbine engine 630. The satellite facility is typically operated by powering the electric motor 620 with primary electrical energy from baseload electrical generation facility 612 during low electricity demand periods, thus filling air storage tanks 623 with economically produced compressed air. In the present invention, the adjective "primary" being used to indicate the source of origin of such electricity is from the baseload facility. Secondary electrical energy is generated by electromagnetic generator 627 during high electricity demand periods in which electricity consumer 618 has a high or even peak demand for electrical energy. Satellite power facility 613 is used to boost or step up or increase voltage in the primary electrical energy transmitted from the baseload electrical generation facility 612 to the electricity 618 during these high demand periods. The transmission wires are electrically conductively connected to the baseload electrical generation facility 612 at the baseload-transmission interface 631. The electricity consumer 618 is electrically conductively connected to the transmission wires by distribution means, such as distribution wires 616 and distribution towers 617, which make up an electrical power distribution means. The satellite-transmission interface 629 joins the satellite facility with the transmission wires and is located between the baseload-transmission interface and the distribution wires 616. By so arranging the satellite power facility 613, the present invention can be used to boost transmission of electrical energy across the transmission wires. The satellite transmission facility 613 acts somewhat like a pumping station of electricity, boosting the voltage of primary electrical energy transmitted from the baseload electrical generation facility 612. During generation at the baseload electrical generation facility 612, the electrical energy is transformed by a transformer (not shown) to a higher transmission voltage, which occurs at the generation transmission interface 631. Higher voltages are used because of their greater efficiency and lower line losses during transmission. However, line losses still occur between the baseload-transmission interface 631 and the satellite-transmission 629. These line losses are due to lost energy due to impedance in the transmission lines, as well as energy diverted for other electricity consumers (not shown) located between the baseload-transmission interface and the satellite-transmission interface 629. Due to these line losses, electricity consumer 618 may not get its full complement of electrical energy, especially during peak demand periods. Thus, satellite facility 613 acts to boost or step up the voltage and lagging current of the electrical energy being transmitted in the transmission wires. The electromagnetic generator 627 is typically a synchronous alternator which is used to boost the voltage of the primary electricity which is being transmitted. In this way, the voltage and current are put in phase, reducing line loss and magnetism in the power lines. Referring to FIG. 7, there is a geographic area 711 upon which the present invention is located. FIG. 7 shows a perspective diagrammatic view of the system of the present invention deployed across a geographic area. FIG. 7 is illustrative and not drawn to scale, but rather is intended to convey general spacial interrelationships involved in the present invention. Baseload electrical generation facility 712 is a facility for the production of electrical energy to be used across geographic area 711. Satellite power facilities 713a, 713b, and 713c, as shown, are simplified illustrations of a system as disclosed in FIGS. 1, 2 or 5. These satellite facilities are geographically distinct from baseload electrical generation facility 712. The geographic distance between baseload electrical generation of facility 712 and, for example, satellite power facility 713a can be as little as a few statute miles or as great as several hundred miles. The baseload electrical generation facility is connected by an electrically conductive transmission system to the satellite power facilities such as satellite power facilities 713a, 713b, and 713c. The transmission system include transmission wires, such as 714a, 714b, 714c, 714d and 714e. Such transmission wires 714a-e are strung between transmission towers, such as transmission towers 715a, 715b, 715c, 715d, and 715e. Typically, such transmission towers are the large steel framed towers commonly seen stretching along the countryside and the transmission wires 714a-e are the high tension or high power lines carried by the transmission towers. Note also, that transmission wires such as 714a-e may also be strung underground in conduits or other systems for traversing distances. The transmission wires 714a-e and the transmission towers 715a-e provide a conduit for transmitting electrical energy across a distance, thus interconnecting a source of electrical power such as a baseload electrical generation facility with a facility needing electrical energy. Also attached to the transmission system, is a system for distributing electrical power to its end users. Included in this system are distribution wires 716a, 716b, 716c, and 716d, and distribution towers, such as 717a, 717b, and 717c. Typically, the distribution system also includes electrical transformers (not shown) and/or electrical substations (not shown) for stepping down the voltage of the electricity transmitted along the transmission wires 714a-e. The electricity is distributed by the distribution system to electricity consumers, such as 718a, 718b, 718c, and 718d. Such electricity consumers can include, but are not limited to, residential homes, industrial factories, offices, street lights, buildings, and any other facility or device consuming electricity. When electricity consumers, such as 718a-d are clustered in a geographically proximate arrangement, and/or have a higher than average demand for electrical power, a high electricity demand area 719 exits. This typically may occur in a densely populated area having high electricity consumption, as well as industrial areas using large quantities of electricity for their operation. The satellite power facilities, such as 713a-c, include in the preferred embodiment an electric motor 720 coupled to an air compressor 721, typically by a drive shaft 722. Compressor 721a (like compressor 621a in FIG. 6) circulates compressed air around the air storage circuit. Electricity from the baseload electrical generation facility 712 is transmitted to satellite power facility 713a and used to power electric motor 720 which in turn drives air compressor 721. Air is compressed in the air compressor which fills air storage tanks 723 with compressed air. Electric motor 720 is powered by such primary electrical energy during low demand periods or off-peak periods of electrical demand. Typically, these periods occur during the late night and early morning hours when electrical consumption is at a minimum. During these low electrical demand periods, since the supply of electricity is relatively large and the demand for electricity is relatively small, the cost of primary electrical energy generated during these low demand periods is relatively low. As such, electric motor 720 at satellite power facility 713a is operated relatively inexpensively during these low demand periods. Consequently, the compressed air that is stored in the air storage tanks 723 is generated at a relatively inexpensive cost. The baseload electrical generation facilities of the present invention are intended to run at near optimal efficiency power generation level, typically within the range of 70% to 90% of rated capacity factor. Peak demand periods are defined as those time periods during which the baseload facility operating at optimal efficiency cannot generate enough power to meet demand. Non-peak demand periods are defined as those time periods which are not peak demand periods. During high electrical power demand periods, compressed air from the air storage tanks is used to generate electricity to meet the high demand. Compressed air from the air storage tanks is combined with fuel from fuel tank 724. The combination of compressed air and fuel is injected into combustion chamber 725. The compressed air fuel mixture is combusted in the combustion chamber and discharged into the turbine 726. The turbine 726 drives electromagnetic generator 727 which generates secondary electrical energy which is transmitted into and across conductors, such as distribution wire 716a and transmission wire 714e. The fuel to be used in the best mode is believed to be natural gas. However, fuel such as JP-4 and other jet fuels and other combustible fuels are acceptable in the present invention. Secondary electrical energy generated in electromagnetic generator 727 is typically generated during high electrical demand periods. Typically, these high demand periods occur during normal business hours during the daytime, but may occur at different times depending on the geographic location and nature of the electricity consumers, such as electricity consumers 18a-d. For example, a high electrical demand period may occur in a business district or industrial area during business hours, such as 8 A.M. to 5 P.M., but then shifts to outlying residential areas as people go from work to their homes in the evenings. Electrical demand in industrial areas may likewise vary or may remain relatively constant if the industrial facility is operated 24 hours a day. Not only does electrical demand shift as a function of geography and time on a daily cycle, but also on a weekly and seasonal cycle. Typically, electrical demand in business and industrial areas is greater during the week than on weekends. Also, electrical demand may be high in hot, summer months to power air conditioning units and high in cold, winter months to power heating units. Note also, that valve 728 may be opened and closed to allow compressed air to flow from the air compressor to air storage tanks during the air compression phase occurring at low demand periods. Valve 728 also can be opened to allow compressed air to flow from air storage tanks 723 to combustion chamber 725 during secondary electrical energy generation phases occurring at high demand periods. Facilities, such as transmission towers 715a-e and transmission wires 714a-e, distribution towers 717a-c and distribution wires, 716a-d make up an electrical grid network. The electrical grid network services a city or community and its various electricity consumers, such as electricity consumers 718a-d. The electrical grid network interconnects electricity consumers with sources of electrical energy, such as baseload electrical generation facility 712 and satellite power facility 713a. Note finally, that at the baseload electrical generation facility 712, the primary electrical energy generated there is typically transformed to a higher voltage for transmission across the transmission wires. This stepping up of voltage typically occurs in electrical transformers (not shown) at a substation (not shown). The present invention may include a control system (not shown in drawings) for scheduling generation of secondary electrical energy and for scheduling compressing of air into the tanks. This control system monitors parameters, such as electricity consumption in given areas, power output of the baseload facility, lines losses, air pressures, and air temperature. The system includes a computer linked to these various parameters by communication lines and analog-digital data input devices. The computer processes the data and provides data output as well as sends control signals to digital-analog devices to activate turbines, motors, compressors, absorption chillers, and valves. Referring now to FIG. 8, storage tank 811 is shown below ground surface 800. FIG. 8 shows a partial detailing of the tank and piping scheme to be used and is substantially similar to tank 11n shown on FIG. 1, and is typical of all tanks of the preferred embodiment. The tank includes tank tube 851 and caps 850 and 850a. Compressed gas is supplied from injection line 825 and flows into line 827a. Line 827a includes isolation valve 826, control valve 826a, safety relief escape 826b, and pressure gauge 826c, and is partially embedded in sand and/or gravel 899. The gas in line 827a flows into tank 811 and or line 827b, which is substantially similar to line 27b of FIG. 1. The gas causes a turbulent flow into the tank and a portion of the gas exits the tank into line 812 and through orifice 830, which is substantially similar to orifice 30d of FIG. 1. The gas continues through a series of tanks and lines (not shown) and then flows into line 833 which is substantially similar to line 33 of FIG. 1. The tanks are surrounded by sand and drainage tiles on a slope and are positioned below the tanks to facilitate drainage. Cathodic protection is afforded using prepackaged magnesium anodes. Note that tanks and lines are to be installed at least 12" away from other underground structures not associated with the line or tank. Referring now to FIG. 9 the structure of forming the preferred high strength, light weight tanks is shown. Cap 950 is partially shown coupled to steel tank tube 951 by gas tungsten arc weld 952. Seam 957 is filled by the weld and reinforced on the outside of tank 911 by field wrapped martinsite steel. The martinsite field wrap includes side wraps 954 and 955, and outer wrap 956, all of which are circumferentially wrapped around the tank tube and the cap. Martinsite wrap 953 is preferably shop wrapped in accordance with U.S. Pat. Nos. 3,880,195 and 3,378,360 as previously incorporated by reference. The preferred wrap is Martinsite M-220 tensile wrap, with a pitch wrap of 0.060"×1.60". The total thickness of the tank wall (tube and wrap) and the wrap thickness are a linear function of the design pressure of the tank. For a 48" diameter storage tank with a storage pressure of 1600 psig, the wrap should be not less than about 0.15 inches and the total thickness of the tank wall should be not less than about 0.4 inches where 60 ksi yield stress steel is used for the tank tube. For a 48" diameter storage tank with a design pressure of about 2800 psig, the wrap should be not less than about 0.233 inches and the total thickness of the tank wall should be not less than about 0.7 inches where 60 ksi steel is used for the tank tube. Sections of tank tubes may be coupled in the field using substantially similar field wrapping. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

A system and method of selectively deployed and utilized compressed air energy storage satellite facilities within an electrical power grid network. The satellite facilities are independent of geological formations and provide means for increasing the load carrying capacity of an electrical power system without increasing the size of the baseload electrical power generation facility or of the power transmission lines. A portion of the compressed gas is circulated back through a compressor located in a gas flow circuit, causing turbulent flow in a series of tanks, thus slowing heat energy loss to the environment. A heat exchanger located in the circuit of gas flow cools the gas while it is being stored, thus reducing the work needed to compress a given mass of gas into the tanks. The system and method utilizes low cost electrical energy produced by a baseload facility during non-peak periods and converts such electricity into potential energy in the form of compressed air. The compressed air is deployed in outlying areas, away from the baseload facility, to provide ready electrical energy during peak demand periods from a location closer to the peak electrical demand consumer. The system and method may also be utilized to boost dropped and/or lagging voltage and/or current to reduce line loss during electrical power transmission.

CROSS REFERENCE TO A RELATED APPLICATION This application is a division of U.S. Ser. No. 10/684,779 filed Oct. 14, 2003 presently “allowed ” and pending issue. BACKGROUND OF THE INVENTION During mechanical injection of meat products, pickling solution is injected into the meat through a multitude of hollow needles, which are repeatedly inserted into the meat to achieve a predetermined percentage addition of solution. Excess solution is collected in a tray beneath the product for use after filtration to remove meat particles. Currently available filter systems usually consist of a wedge wire drum, which rotates slowly. The recovered solution runs over the outside of the drum causing liquids to pass between the wires into a tank while the solid particles are scraped off the outside of the drum as it rotates. The solution is then filtered through static filter screens before being pumped back to the needles. Often some solution is transferred with the meat particles still in the solution. Furthermore, when filtration is not completely effective in removing particles from the injection pickle solution, the particles end up in the pickle solution that returns to the needles. This particle matter in the solution can cause clogging which has an adverse effect on the percentage injection rate. In addition, filters, particularly static screens, are prone to becoming clogged by the particles remaining in the solution. This causes the need for repeated cleaning to reduce pump starvation, loss in injection pressure, and injection percentage variation. Cleaning of static filters without cleaning the whole system can allow solid matter to pass through the filter and clog the system further down stream. Thus, it is a primary object of the present invention to provide a filtering system for the filtering of injector fluids that improves upon the state of the art. Another object of the present invention is to provide a filter system that uses the height of flutes on an auger to retain fluid while still transporting solid materials to the end of the filter. A further object of the present invention is to provide a filtering system that allows a fluid surface of liquid to be continually strained of foam. Yet a further object of the present invention is to improve the effectiveness of a filtration system. A further object of the present invention is to provide a filtration system that can be used in filtration applications other than in injection of meat products. And still yet a further object of the present invention is to provide a filter that can be back-flushed while the machine is running. These and other objects, feature, or advantages of the present invention will be apparent from the specification and claims. SUMMARY OF THE INVENTION The present invention provides a filtering system that has a filter tank and a first rotary filter consisting of a filtering cylinder with an internal auger. In the application of the invention, both the filtering cylinder and the internal auger rotate together. The filter system further comprises a substantially enclosed second rotary filter that receives solid particles filtered from the first rotary filter. A scraper then removes the solid particles from the outside surface of the secondary filter and a pipe takes the filtered liquid from the inside of the secondary filter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a meat injection machine. FIG. 2 is a side view of the filtration system of the meat injection machine. FIG. 3 is a sectional view of the filtering system of the meat injection machine taken from line 4 — 4 of FIG. 2 . FIG. 4 shows an enlarged side view of the filter system of the meat injection machine showing the scraper. DESCRIPTION OF THE PREFERRED EMBODIMENT The term fluid, pickle fluid, and liquid are used interchangeably throughout this disclosure and all represent the liquid portion of a liquid and solid suspension. Solid, solid particles, solid material, and meat particles are also used interchangeably throughout this disclosure and represent the solid portion within the liquid of the solid suspension. The terms pickle injection, injector fluid, pickle solution, and suspension are used interchangeably throughout this disclosure and all represent a liquid and solid suspension or mixture. As can be seen in FIG. 1 , the filtration system of the current invention can be found in meat injection machine 10 . Generally the filter system has a first rotary filter 12 , a second rotary filter 14 , a tank 16 , and a pump 18 that receives the filtered pickle injection from the tank 16 and transports the pickle injection to the injector needles 20 . The injector needles 20 are protected by head cover 22 and inject meat product 24 with the filtered pickle injection. FIGS. 2–4 show the filtering system of the meat injection machine 10 . The filtering system has a chute 26 that brings an unfiltered pickle solution into the first rotary filter 12 . The first rotary filter 12 consists of a wedge wire wound cylinder 28 having an auger 30 . The auger 30 is attached to an end plate 31 that has a central opening 33 that allows the chute 26 to protrude there through and bayonet slots 32 receive the auger 30 so that the auger 30 fits snuggly within the cylinder 12 and can rotate therewith. Cylinder 28 and auger 30 rotate together and are releasably attached by the quick-release bayonet connection. Preferably cylinder 28 has a wedge shaped wire with a flat edge on the inside and a uniform gap between wires of 0.5 mm (0.02 inches). For different applications, wires of different sizes and dimensions are used. For example, for optimizing the filtration process the gap between wires is varied. In another application the cylinder 28 is made of material that has holes instead of wedged wire. Also, auger 30 is made with a uniform pitch spiral or a variable pitch depending on the application. Auger 30 also has flutes (not shown in drawings) that are able to retain fluid while still transporting solid material to the end of the cylinder 28 , and can be of a height that varies along its length to optimize the filtration of liquid through the filtering cylinder 28 or of a uniform height along its length. The Auger can also have uniform pitch along its length or variable pitch along its length to optimize the filtration of liquid through the filtering cylinder. A gear 34 is fixed to the second end 35 of first rotary filter 12 and is meshed with a pinion wheel 36 on shaft 38 which is connected to the motor 40 on the meat injection machine 10 . In operation the motor rotates the shaft 38 of pinion 36 causing the gear 34 to rotate. The secondary filter 14 is comprised of a wedge wire wound cylinder 42 having an outer surface 45 , a plate 44 that is part of the sidewall of the tank 16 at one end, and a gear 43 at the opposite end that form an interior chamber 53 that is partially submerged in tank 16 . Gear 43 is operably connected to pinion wheel 36 so that the pinion wheel 36 operatively rotates both the first rotary filter 12 and the second rotary filter 14 . Operably attached to the tank 16 is a scraper 48 used to clean the cylinder 42 . Scraper 48 can be a mechanical blade or an air knife. Also attached to the tank 16 is a container 50 for receiving material removed from cylinder 42 . A pipe 52 extends outwardly from the plate 44 and is in communication with the interior chamber 53 of the secondary filter 14 . The pipe 52 provides an outlet for the filtered liquid in the interior chamber 53 of the secondary filter 14 . Pipe 52 is operably connected to the pump 18 to transport filtered liquid from the interior chamber 53 of the secondary filter 14 to the injection needles 20 . In operation, a pickle fluid having meat particles falls from chute 26 into cylinder 28 . Liquid passes through the gaps between the wires of cylinder 28 and drains into tank 16 , while the solid particles are transported along the length of cylinder 28 by the rotating auger 30 . In one embodiment the auger 30 and filtering cylinder 28 are rotated at different speeds. The solid particles with some excess liquid then falls from the second end 35 of the cylinder 28 onto the outer surface 45 of the second rotary filter 14 . As the cylinder 42 rotates, solid particles collect on the wedge wire and are transported to the scraper 48 where the solid particles are deposited into container 50 . As pump 18 draws liquid via pipe 52 from the interior chamber 53 of secondary rotating filter 14 it generates a negative pressure in interior chamber 53 . This draws fluid from tank 16 into interior chamber 53 through cylinder 42 . Any remaining solids in this fluid are deposited on the outer surface 45 of rotating cylinder 42 , which transports them to scraper 48 as it rotates. Any foam (protein and fat) floating on the surface of fluid in tank 16 is lifted off as cylinder 42 rotates and it too is transported to scraper 48 which removes it and deposits it into container 50 . Then pipe 52 transports the filtered liquid from the interior chamber 53 of the cylinder 42 to the injection needles 20 . As the pipe 52 transports filtered liquid from the interior chamber 53 of cylinder 42 extra unfiltered liquid is introduced to the tank 16 via the first rotary cylinder 12 , replenishing the fluid lost in the system. In one application the filters are backwashed during the operation of the filtering system. To backwash the first rotary filter 12 , an air knife is installed close to the first rotary filter 12 . Similarly, the second rotary filter 14 may be backwashed by placing a nozzle within the second rotary filter. Fluid is pumped at high pressure at the interior of the second rotary filter 14 to back flush it and force particles that may be clogging it back into the tank 16 . Thus, a filtering system for the filtering of injector fluids that improves upon the state of the art is disclosed. The filtering system eliminates the need for static filters by using two rotating cylindrical filters. The system also creates a whirlpool effect that allows foam to be continually strained from the surface of the liquid in the tank. This system may be used in a meat pickling process or any other process wherein solid particles are to be filtered out of a liquid. Furthermore, the filters in this system may be back-flushed while the machine in operation. It will be appreciated by those skilled in the art that other various modifications could be made to the device without the parting from the spirit in scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered thereby.

A filtering system used on a meat injection machine that injects pickling into meat products. The filter consists of a tank and a first and second rotary filter. The first rotary filter uses a wedge wire wound cylinder and augers having flutes that rotate to catch and push away solid particles toward the second filter. The second filter then uses more wedge wire in a whirlpool effect to ensure all solid materials and foam are in the outside of the filter. Injector fluid is then taken from the center of the inside volume of the second filter to be used in injection needles.

CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2010-004389 filed on Jan. 12, 2010, the entire contents of which are incorporated herein by reference. FIELD The embodiments discussed herein are related to an apparatus and a method for managing a network system. BACKGROUND Hitherto, when an error occurs in a large-scale system having many components, locating its cause has been desirable. It is desirable that a matrix of correlations between components of a system is created, and when an error occurs, the cause is located with reference to the matrix. However, the technology in the past that creates a matrix of correlations for each system may desire recreation of a matrix every time its system configuration changes. In a system immediately after changed, less error information is available. Thus, locating a cause of an error may not be available if any with reference to the matrix. When identifying a cause with reference to the matrix is not available, an operator may be desirable to manually classify the trouble and as a result increase its man-hours. With the increases in scale of systems, an environment of a virtualized system, what is called a cloud environment has been increasingly used. One of advantages of a virtualized system is that its system configuration may be dynamically changed without influences on its services. Thus, the technology allowing support for location of a cause of an error if occurs even after the system configuration is changed is particularly desirable upon trouble investigation in the virtual environment. In this way, it is desirable for technologies in the past to provide a sufficient support for trouble investigation in a large-scale system or virtual environment, and the implementation of a technology for supporting trouble investigation has been a desired goal. SUMMARY According to an aspect of an embodiment, an apparatus for managing a network system including a plurality of components, the apparatus includes a memory that stores component type data of each component of the plurality of components, component relation data including relation information indicating a pair of components related to each other in the network system and error history data including error information of respective error components in the plurality of components, and a processor that executes a procedure including extracting a pair of component type data as a relation class candidate on the basis of the component type data of a pair of error components indicated by the error information in the error history data, the pair of error components being indicated by the relation information. The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram of a network management supporting system according to a first embodiment; FIG. 2 is an explanatory diagram regarding the use of relation classes among different systems; FIG. 3 is a schematic configuration diagram of a network management supporting system according to a second embodiment; FIG. 4 is a schematic configuration diagram of a trouble investigation system that investigates a failure occurring in a network; FIG. 5 is an explanatory diagram of an example of the configuration of a network; FIG. 6 is an explanatory diagram regarding the superimposition of investigation-range-limited trees; FIG. 7 is an explanatory diagram of a concrete example of configuration information; FIG. 8 is an explanatory diagram of a concrete example of an error history; FIG. 9 is an explanatory diagram regarding combinations of components extracted by a classification unit; FIG. 10 is a diagram of a relation class candidate list generated by the classification unit; FIG. 11 is a diagram illustrating the types of CIs serving as sources and targets of determined relation classes; FIG. 12 is an explanatory diagram of relations and relation classes to apply; FIG. 13 is an explanatory diagram of configuration information after the relation classes are applied; FIG. 14 is an explanatory diagram regarding a concrete example of failure handling information; FIG. 15 is a diagram of a concrete example of investigation details generated by an investigation detail generating unit; FIG. 16 is an explanatory diagram of a concrete example of error detection information; FIG. 17 is an explanatory diagram describing a failure information database (DB) and attenuation levels; FIG. 18 is an explanatory diagram of investigation-range-limited trees generated by an investigation range limiting unit; FIG. 19 is a flowchart describing generation of a relation class; and FIG. 20 is a flowchart describing generation of investigation details. DESCRIPTION OF EMBODIMENTS Embodiments of a network management supporting system, a network management supporting apparatus, a network management supporting method, and a program disclosed in the subject application will be described in detail below with reference to the drawings. The embodiments do not limit the disclosed art. FIG. 1 is a schematic configuration diagram of a network management supporting system according to a first embodiment. A network management supporting system 60 illustrated in FIG. 1 includes a classification unit 61 , an aggregation unit 62 , and a relation class determining unit 63 . The network management supporting system 60 is configured with a computer system including a processor and a memory. The classification unit 61 , an aggregation unit 62 , and a relation class determining unit 63 are realized by causing the processor to execute a managing operation program. The failure managing operation program may be recorded in a computer readable non-transitory medium such as a semiconductor memory, a hard disk, a flexible disk (FD), a CD-ROM, an MO and a DVD. The classification unit 61 refers to configuration information 21 indicating relations provided among the components of a network, and an error history 51 that is history information of errors occurring in the components, and extracts a combination of two components where errors are occurring and which have a relation. For the extracted combination of components, the classification unit 61 classifies the type of a component serving as a source of the combination and the type of a component serving as a target of the combination as candidates for a relation class indicating the relationship between components where an error is propagating. The configuration information 21 and error history 51 are stored in a memory of the network management supporting system 60 . The memory includes not only a semiconductor memory but also a storage medium such as an electromagnetic tape, a hard disk, a FD, a CD-ROM, an MO and a DVD. Moreover, the configuration information 21 and error history 51 are stored in a plurality of memories of the network management supporting system 60 . The aggregation unit 62 aggregates the results of classifications performed by the classification unit 61 . Then, the aggregation unit 62 obtains the number of appearances of each candidate for a relation class. Based on the results of aggregation performed by the aggregation unit 62 , the relation class determining unit 63 determines, among the candidates for a relation class, a relation class to be used in estimating a point causing an error that occurs in the network. The relation class determined in this manner indicates the propagating direction of an error between the components. Thus, when an error occurs in components of a network, the point where a failure causing the error has occurred may be estimated by tracking a relation class from the components in which the error is occurring. As described above, the network management supporting system according to the first embodiment can support trouble investigation in a system by generating a relation class that is abstraction of the propagating direction of an error based on the types of components of a network, from configuration information of the network and error history information. Narrowing down the possible points of a failure using a relation class does not depend on the configuration of a network system and is thus highly versatile. Therefore, such a technique is applicable to a newly configured network system and even to a network system having a changed configuration. Trouble investigation in a large-scale network system or a virtual environment may be supported by narrowing down the possible points of a failure. FIG. 2 is an explanatory diagram regarding the use of relation classes among different systems. As illustrated in FIG. 2 , relation classes are generated, from systems i_ 1 to i_n, as advance preparations. The relation classes may be used when a failure occurs in other systems o_ 1 to o_m to estimate the point where the failure has occurred in the systems o_ 1 to o_m. The classification unit 61 , the aggregation unit 62 , and the relation class determining unit 63 may be arranged in a dispersed manner over the network system. Alternatively, a network management supporting apparatus including the classification unit 61 , the aggregation unit 62 , and the relation class determining unit 63 that are arranged in a single housing may be implemented. FIG. 3 is a schematic configuration diagram of a network management supporting system according to a second embodiment. The network management supporting system illustrated in FIG. 2 includes a network management information generating apparatus 70 , a failure point estimating apparatus 30 , a configuration management database (CMDB) 31 , and a failure information database (DB) 32 . The failure point estimating apparatus 30 is configured with a computer system including a processor and a memory. The relation class applying unit 11 , an investigation range limiting unit 12 , and a failure position candidate estimating unit 13 are realized by causing the processor to execute a failure position estimation program. The CMDB 31 holds the configuration information 21 which is information indicating relationships among the components of a network. The failure information DB 32 is a database that holds the error history 51 indicating the history of errors that have occurred in the past and a history of relations tracked when errors have occurred in the past. The failure information DB 32 holds, as an example of a history of relations tracked when errors have occurred in the past, operation path history information 27 and failure handling information 28 . The operation path history information 27 is information indicating a path of relations tracked for specifying the point of a failure causing an error that has occurred in the past. The failure handling information 28 includes path information from the component in which an error has been detected to the component specified as the cause of the error. The network management information generating apparatus 70 includes the classification unit 61 , the aggregation unit 62 , the relation class determining unit 63 , a relation class applying unit 64 , and an investigation detail generating unit 65 . The classification unit 61 refers to the configuration information 21 held in the CMDB 31 and the error history 51 held in the failure information DB 32 , and extracts a combination of two components where errors are occurring and which have a relation. For the extracted combination of components, the classification unit 61 classifies the type of a component serving as a source of the combination and the type of a component serving as a target of the combination as candidates for a relation class indicating the relationship between components where an error is propagating. The aggregation unit 62 aggregates the results of classifications performed by the classification unit 61 . Then, the aggregation unit 62 obtains the number of appearances of each candidate for a relation class. Based on the results of aggregation performed by the aggregation unit 62 , the relation class determining unit 63 determines, among the candidates for a relation class, a relation class (relation classes) 23 to be used in estimating a point causing an error that occurs in the network, and outputs the relation class (relation classes) 23 to the failure point estimating apparatus 30 . The relation class applying unit 64 performs abstraction by applying a relation class (relation classes) to the configuration information 21 held in the CMDB 31 . The investigation detail generating unit 65 generates investigation details to be associated with a relation class (relation classes) that may be tracked for the type of error. Specifically, the investigation detail generating unit 65 refers to the failure handling information 28 , which is a handling history for specifying the path from a component in which an error has occurred to a component in which a failure causing the error has occurred, applies a relation class (relation classes) to the path indicated in the handling history, and thus obtains the result as investigation details 24 . The investigation detail generating unit 65 outputs the generated investigation details 24 to the failure point estimating apparatus 30 . The failure point estimating apparatus 30 includes a relation class applying unit 11 , an investigation range limiting unit 12 , and a failure occurrence point candidate estimating unit 13 . The failure point estimating apparatus 30 uses the relation class (relation classes) 23 , the investigation details 24 , and error detection information 25 . The error detection information 25 is information obtained as a result of detection of a component having an error and the type of the error among the components of a network system. The relation class (relation classes) 23 , the investigation details 24 and the error detection information 25 is stored in a storage unit of the failure point estimating apparatus 30 . The relation class applying unit 11 refers to the configuration information 21 and the relation class (relation classes) 23 to apply the relation class (relation classes) to the relationship between components included in the configuration information 21 . The investigation range limiting unit 12 refers to the relation class (relation classes) 23 , the investigation details 24 , the error detection information 25 , and the failure information DB 32 to obtain, as an investigation-range-limited tree, components and a relation (relations) tracked in accordance with the investigation details 24 for each component having an error. The failure occurrence point candidate estimating unit 13 superimposes investigation-range-limited trees as an example of an investigation range, obtained for the individual components having errors and estimates candidates for the point where a failure causing the errors has occurred. FIG. 4 is a schematic configuration diagram of a trouble investigation system that investigates a failure occurring in a network. A trouble investigation system 40 illustrated in FIG. 4 has an error detecting unit 41 , a failure point estimating unit 42 , a failure cause specifying unit 43 , and a handling unit 44 . The failure point estimating apparatus 30 illustrated in FIG. 3 functions as the failure point estimating unit 42 . The error detecting unit 41 is a processor that detects an error occurring in a component of a network and notifies the failure point estimating unit 42 of the detected error. The failure point estimating apparatus 30 functioning as the failure point estimating unit 42 uses the information provided in the notification as the error detection information 25 . The failure point estimating apparatus 30 functioning as the failure point estimating unit 42 estimates candidates for the point where the failure causing the error has occurred and outputs the candidates to the error cause specifying unit 43 . The error cause specifying unit 43 uses the output from the failure point estimating unit 42 to specify the cause of the error. The handling unit 44 handles the specified point so as to overcome the error that has occurred. FIG. 5 is an explanatory diagram of an example of the configuration of a network. The network illustrated in FIG. 5 includes configuration items (CIs) pm 11 to pm 13 , CIs va 01 to va 03 , CIs vb 01 to vb 03 , a CI Ta, and a CI Tb as components. The network illustrated in FIG. 5 is a virtual network including the CIs pm 11 to pm 13 as physical machines, the CIs va 01 to va 03 and the CIs vb 01 to vb 03 as virtual machines, and the CIs Ta and Tb as services. Each of the CIs may be one computer, or plural CIs may operate on one computer. Each of the CIs is given identification information uniquely defined in the network and may operate as an individual component. Information for identifying a CI is called an “instance”. A relation is defined between CIs. This relation between the CIs is called a “relation”. A direction is defined for a relation, and the origin of the relation is called a “source (src)” and the destination of the relation is called a “target (tgt)” or a “destination (dst)”. In the network illustrated in FIG. 5 , relations rel 01 to rel 24 are defined. The relation rel 01 has the CI va 01 as its source and the CI pm 11 as its target. The relation rel 02 has the CI pm 11 as its source and the CI va 01 as its target. The relation rel 03 has the CI pm 11 as its source and the CI vb 01 as its target. The relation rel 04 has the CI vb 01 as its source and the CI pm 11 as its target. The relation rel 05 has the CI va 02 as its source and the CI pm 12 as its target. The relation rel 06 has the CI pm 12 as its source and the CI va 02 as its target. The relation rel 07 has the CI pm 12 as its source and the CI vb 02 as its target. The relation rel 08 has the CI vb 02 as its source and the CI pm 12 as its target. The relation rel 09 has the CI va 03 as its source and the CI pm 13 as its target. The relation rel 10 has the CI pm 13 as its source and the CI va 03 as its target. The relation rel 11 has the CI pm 13 as its source and the CI vb 03 as its target. The relation rel 12 has the CI vb 03 as its source and the CI pm 13 as its target. The relation rel 13 has the CI va 01 as its source and CI Ta as its target. The relation rel 14 has the CI va 02 as its source and the CI Ta as its target. The relation rel 15 has the CI va 03 as its source and the CI Ta as its target. The relation rel 16 has the CI vb 01 as its source and the CI Tb as its target. The relation rel 17 has the CI vb 02 as its source and the CI Tb as its target. The relation rel 18 has the CI vb 03 as its source and the CI Tb as its target. The relation rel 19 has the CI va 02 as its source and the CI va 01 as its target. The relation rel 20 has the CI va 03 as its source and the CI va 02 as its target. The relation rel 21 has the CI vb 02 as its source and the CI vb 01 as its target. The relation rel 22 has the CI vb 03 as its source and the CI vb 02 as its target. The relation rel 23 has the CI va 01 as its source and the CI Ta as its target. The relation rel 24 has the CI vb 01 as its source and the CI Tb as its target. In the network, the CI Ta and the CI Tb are accessed by clients (not illustrated) and provide certain services to the clients. The CI va 01 , which is a virtual machine, is responsible for a web layer of a service provided by the CI Ta. The CI va 02 , which is a virtual machine, is responsible for an application layer of a service provided by the CI Ta. The CI va 03 , which is a virtual machine, is responsible for a database layer of a service provided by the CI Ta. Similarly, the CI vb 01 , which is a virtual machine, is responsible for a web layer of a service provided by the CI Tb. The CI vb 02 , which is a virtual machine, is responsible for an application layer of a service provided by the CI Tb. The CI vb 03 , which is a virtual machine, is responsible for a database layer of a service provided by the CI Tb. The CI va 01 and the CI vb 01 , which are virtual machines responsible for a web layer, use the CI pm 11 , which is a physical machine. The CI va 02 and the CI vb 02 , which are virtual machines responsible for an application layer, use the CI pm 12 , which is a physical machine. The CI va 03 and the CI vb 03 , which are virtual machines responsible for a database layer, use the CI pm 13 , which is a physical machine. When an error occurs in this network, the failure point estimating apparatus 30 generates investigation-range-limited trees by tracking relations from the CIs in which the error has been detected, superimposes the investigation-range-limited trees, and estimates candidates for the point where a failure causing the error has occurred. FIG. 6 is an explanatory diagram regarding the superimposition of investigation-range-limited trees. FIG. 6 illustrates an example of the case in which an error has been detected in the CI Ta, the CI va 01 , and the CI pm 11 . The failure point estimating apparatus 30 generates an investigation-range-limited tree A 01 by tracking relations from the CI Ta. The investigation-range-limited tree A 01 has a root in the CI Ta and the CI va 01 to va 03 as nodes connecting to the CI Ta. The investigation-range-limited tree A 01 further has the CI pm 11 as a node connecting to the CI va 01 and the CI pm 12 as a node connecting to the CI va 02 . Here, the investigation-range-limited tree A 01 does not include the CI pm 13 . This is because an excessive increase in size of the investigation-range-limited trees may be prevented by limiting the range of relations to be tracked for generating the investigation-range-limited trees. The range of relations to be tracked for generating investigation-range-limited trees may be limited by defining its hop values and attenuation levels. The hop values and attenuation levels will be described later. The failure point estimating apparatus 30 generates an investigation-range-limited tree A 02 by tracking relations from the CI va 01 . The investigation-range-limited tree A 02 has a root in the CI va 01 and the CI pm 11 as a node connecting to the CI va 01 . The failure point estimating apparatus 30 generates an investigation-range-limited tree A 03 by tracking relations from the CI pmn 11 . In the example illustrated in FIG. 5 , no relations may be tracked from the CI pmn 11 , and the investigation-range-limited tree A 03 only has the CI pm 11 . The failure point estimating apparatus 30 superimposes the investigation-range-limited trees A 01 to A 03 and estimates the CI pmn 11 with maximum superimposition as a candidate for the point where the failure has occurred. FIG. 7 is an explanatory diagram of a concrete example of the configuration information 21 . The configuration information 21 illustrated in FIG. 7 has a Cis tag that defines CIs and a Relations tag that defines relations within a cmdb tag. The Cis tag contains descriptions of ids and types of CIs. The example illustrated in FIG. 7 includes the CIs pmn 11 to pm 13 , the CI va 01 , and the CI Tb within the Cis tag. The CIs pmn 11 to pm 13 are each associated with “PM” indicating that its type is a physical machine. Similarly, the CI va 01 is associated with “VA” indicating that its type is a virtual machine. The CI Tb is associated with “Service” indicating that its type is a service. The example illustrated in FIG. 7 has relations rel 01 , rel 02 , and rel 24 within the Relations tag. The relation rel 01 has the va 01 as its source src and the pm 11 as dst corresponding to the target and is associated with “vm-pm” as a type indicating a combination of the types of the source and target. The relation rel 02 has the pmn 11 as its source src and the va 01 as dst corresponding to the target and is associated with “pm-vm” as a type indicating a combination of the types of the source and target. The relation rel 24 has the vb 01 as its source src and the Tb as dst corresponding to the target and is associated with “tenant-vm” as a type indicating a combination of the types of the source and target. FIG. 8 is an explanatory diagram of a concrete example of the error history 51 . The error history 51 has items including an error id, occurrence time, detected point, and error details. The error id is information to be used in identifying an entry of the error history 51 . The occurrence time indicates the time at which an error has occurred. The detected point has identification information of a CI in which an error has occurred and information indicating the type of the CI. The error details indicate the details of an error that has occurred. In the example illustrated in FIG. 8 , an entry having 01 as an error id indicates that on Jul. 1, 2009, 00:01:30, a ping timeout error has occurred at the instance pm 11 whose CI type is PM. Similarly, an entry having 02 as an error id indicates that on Jul. 1, 2009, 00:01:40, a ping timeout error has occurred at the instance va 01 whose CI type is VM. An entry having 03 as an error id indicates that on Jul. 1, 2009, 00:02:00, a service error has occurred at the instance Ta whose CI type is Svc. FIG. 9 is an explanatory diagram regarding combinations of components extracted by the classification unit 61 . The classification unit 61 selects two errors from the error history 51 . When a relation has been set in components having the selected two errors, a component having an error whose occurrence time is earlier is regarded as a component serving as the propagation source of an error, and a component having an error whose occurrence time is later is regarded as a component serving as the propagation destination of the error. The classification unit 61 checks, for example, combinations of all errors indicated in the error history 51 to determine whether a relation has been set in two combined components having errors. Alternatively, the classification unit 61 may check combinations of two errors whose occurrence times have a difference that is less than or equal to a certain time to determine whether a relation has been set in two components having the errors. In the example illustrated in FIG. 9 , with regard to a relation between two extracted components, correlations among the type of a CI serving as the propagation source, the type of an error that has occurred, the type of a CI serving as the propagation destination of an error, the type of an error that has occurred, the direction of the relation, and the propagating direction of the error are illustrated. In the relation rel 02 , a CI serving as the propagation source is PM, and its error type is ping timeout; and a CI serving as the propagation destination is VM, and its error type is ping timeout. The direction of the relation rel 02 is from the propagation source to the propagation direction. That is, it is indicated that, after a ping timeout occurs in the CI whose type is PM, which is the source of the relation rel 02 , a ping timeout occurs in the CI whose type is VM, which is the target of the relation rel 02 . In the relation rel 06 , a CI serving as the propagation source is PM, and its error type is ping timeout; and a CI serving as the propagation destination is VM, and its error type is ping timeout. The direction of the relation rel 06 is from the propagation source to the propagation direction. That is, it is indicated that, after a ping timeout occurs in the CI whose type is PM, which is the source of the relation rel 06 , a ping timeout occurs in the CI whose type is VM, which is the target of the relation rel 06 . In the relation rel 13 , a CI serving as the propagation source is VM, and its error type is ping timeout; and a CI serving as the propagation destination is Svc, and its error type is service error. The direction of the relation rel 13 is from the propagation source to the propagation direction. That is, it is indicated that, after a ping timeout occurs in the CI whose type is VM, which is the source of the relation rel 13 , a ping timeout occurs in the CI whose type is Svc, which is the target of the relation rel 13 . In the relation rel 01 , a CI serving as the propagation source is VM, and its error type is ping timeout; and a CI serving as the propagation destination is PM, and its error type is ping timeout. The direction of the relation rel 01 is from the propagation destination to the propagation source. That is, it is indicated that, after a ping timeout occurs in the CI whose type is PM, which is the target of the relation rel 01 , a ping timeout occurs in the CI whose type is VM, which is the source of the relation rel 01 . The classification unit 61 performs abstraction of an extracted relation using the type of a CI serving as the propagation source, the type of its error, the type of a CI serving as the propagation destination, the type of its error, and the direction of the relation, and classifies the result as a candidate for a relation class. In the example illustrated in FIG. 9 , the relation rel 02 and the relation rel 06 are common in all of the following: the type of a CI serving as the propagation source, the type of its error, the type of a CI serving as the propagation destination, the type of its error, and the direction of the relation. The classification unit 61 generates a candidate c 01 for a relation class from information indicated in the relation rel 02 and the relation rel 06 . Therefore, the candidate c 01 for a relation class is such that the type of a CI serving as the propagation source is PM, the type of its error is ping timeout, the type of a CI serving as the propagation destination is VM, the type of its error is ping timeout, and the direction of the relation is from the propagation source to the propagation destination. FIG. 10 is a diagram of a concrete example of a relation class candidate list generated by the classification unit 61 . In the example illustrated in FIG. 10 , in addition to the above-described candidate 01 for a relation class, candidates c 02 to c 05 are illustrated. The candidate c 02 for a relation class is such that the type of a CI serving as the propagation source is VM, the type of its error is ping timeout, the type of a CI serving as the propagation destination is Svc, the type of its error is app error, and the direction of the relation is from the propagation source to the propagation destination. The candidate c 03 for a relation class is such that the type of a CI serving as the propagation source is VM, the type of its error is cpu overload, the type of a CI serving as the propagation destination is Svc, the type of its error is slowdown, and the direction of the relation is from the propagation source to the propagation destination. The candidate c 04 for a relation class is such that the type of a CI serving as the propagation source is VM, the type of its error is cpu overload, the type of a CI serving as the propagation destination is VM, the type of its error is app slowdown, and the direction of the relation is from the propagation source to the propagation destination. The candidate c 05 for a relation class is such that the type of a CI serving as the propagation source is VM, the type of its error is request burst, the type of a CI serving as the propagation destination is PM, the type of its error is nw overload, and the direction of the relation is from the propagation destination to the propagation source. The aggregation unit 62 obtains the number of appearances of each of the candidates c 01 to c 05 for a relation class. In the example illustrated in FIG. 10 , the number of appearances of the candidate c 01 for a relation class is 10 ; the number of appearances of the candidate c 02 for a relation class is 8 ; the number of appearances of the candidate c 03 for a relation class is 7 ; the number of appearances of the candidate c 04 for a relation class is 5 ; and the number of appearances of the candidate c 05 for a relation class is 5 . The relation class determining unit 63 determines a candidate for a relation class whose number of appearances is greater than or equal to a threshold as a relation class. For example, when a threshold of the number of appearances in the example illustrated in FIG. 10 is 5 , among the candidates c 01 to c 05 for a relation class, all are determined as relation classes c 01 to c 05 . FIG. 11 is a diagram illustrating the types of CIs serving as sources and targets of the determined relation classes. In the relation class c 01 , the type of a CI serving as a source is PM, and the type of a CI serving as a target is VM. In the relation class c 02 , the type of a CI serving as a source is VM, and the type of a CI serving as a target is Svc. In the relation class c 03 , the type of a CI serving as a source is VM, and the type of a CI serving as a target is Svc. In the relation class c 04 , the type of a CI serving as a source is VM, and the type of a CI serving as a target is VM. In the relation class c 05 , the type of a CI serving as a source is VM, and the type of a CI serving as a target is PM. The relation class applying unit 64 applies the relation classes based on the types of CIs serving as the sources and targets of the individual relations indicated in the configuration information 21 . FIG. 12 is an explanatory diagram of relations and relation classes to apply. In the example illustrated in FIG. 12 , the relation class c 05 is applied to the relations rel 01 and rel 04 . The relation class c 01 is applied to the relations rel 02 and rel 03 . The relation class c 04 is applied to the relations rel 19 and rel 20 . Both the relation classes c 02 and c 03 are applied to the relations rel 23 and rel 24 . For the individual relations, the relation class applying unit 64 adds the applied relation classes to the configuration information 21 . FIG. 13 is an explanatory diagram of configuration information after the relation classes are applied. Relation classes are added to the relations in addition to the configuration information illustrated in FIG. 7 . More specifically, a description, class=“c 05 ”, indicating the relation class of the relation rel 01 is added. A description, class=“c 01 ”, indicating the relation class of the relation rel 02 is added. A description, class=“c 02 , c 03 ”, indicating the relation classes of the relation rel 24 is added. FIG. 14 is an explanatory diagram regarding a concrete example of the failure handling information 28 . The failure handling information 28 indicates that the cause of a service error occurring in the CI Ta is a failure in the CI pm 12 , that the path from the CI Ta to the CI pm 12 includes the relations rel 14 and rel 06 , and the details of handling the failure. Similarly, the failure handling information 28 indicates that the cause of a service error occurring in the CI Tb is a failure in the CI vb 02 , that the path from the CI Tb to the CI bv 02 includes the relation rel 17 , and the details of handling the failure. The investigation detail generating unit 65 refers to the failure handling information 28 and generates the investigation details 24 . Specifically, the investigation detail generating unit 65 applies a relation class (relation classes) to a path indicated in the failure handling information 28 , and, among items of information indicated in the failure handling information 28 , performs abstraction of a CI having an error by replacing that CI with a CI type and abstraction of a CI serving as the point of a failure causing the error by replacing that CI with a CI type. FIG. 15 illustrates a concrete example of the investigation details 24 generated by the investigation detail generating unit 65 . In the example illustrated in FIG. 15 , the type of a CI where an error has occurred is Svc, and the type of a point where a failure causing the error has occurred is PM or VM. The relation classes of paths used to perform sorting when the type of a point where a failure causing the error has occurred is PM are c 02 +c 03 to c 01 . The relation classes of paths used to perform sorting when the type of a point where a failure causing the error has occurred is VM are c 02 +c 03 . With reference to the investigation details 24 , if a service error occurs in a CI whose type is Svc, it is indicated that PM or VM may be the cause of the error. In addition, when the cause is PM, it is indicated that a CI causing the error may be reached by tracking relations whose relation classes are c 02 and c 03 and then tracking a relation whose relation class is c 01 . Similarly, when the cause is VM, it is indicated that a CI causing the error may be reached by tracking relations whose relation classes are c 02 and c 03 . FIG. 16 is an explanatory diagram of a concrete example of the error detection information 25 . The error detection information 25 has a CI in which an error has occurred and the type of symptom of the error that has occurred. In the example illustrated in FIG. 16 , it is indicated that a service error has occurred in the CI Ta. FIG. 17 is an explanatory diagram illustrating the failure information DB 32 and attenuation levels. The failure information DB 32 has the operation path history information 27 and the failure handling information 28 . The operation path history information 27 describes that, when a service error occurs in the CI Ta, the point of a failure is investigated by tracking the relation rel 13 and the relation rel 02 in a first operation 01 - 1 , and by tracking the relation rel 14 and the relation rel 06 in the next operation 01 - 2 . The operation path history information 27 describes that, when a service error occurs in the CI Tb, the point of a failure is investigated by tracking the relation rel 17 in operation 02 - 1 . The operation may include manual investigation performed by an operator or a tracking operation performed in the past by the failure point estimating apparatus 30 . The failure handling information 28 indicates, as has been described above, that the cause of the service error occurring in the CI Ta is the failure in the CI pm 12 , that the paths from the CI Ta to the CI pm 12 are the relations rel 14 and rel 06 , and the details of the handling of the failure. In the same manner, the failure handling information 28 describes that the cause of the service error occurring in the CI Tb is the failure in the CI vb 02 , that the path from the CI Tb to the CI vb 02 is the relation rel 17 , and the details of the handling of the failure. The investigation range limiting unit 12 uses the failure information DB 32 to determine the range of relations to be tracked for generating investigation-range-limited trees. The failure point estimating apparatus 30 predetermines a certain hop value and decrements the hop value every time a relation is tracked. Then, the failure location estimating apparatus 30 tracks relations within the range where the hop value becomes less than or equal to 0 and generates investigation-range-limited trees. A value subtracted from the hop value when a relation is tracked is referred to as an “attenuation level”. The investigation range limiting unit 12 defines a lower attenuation level for a relation registered in the failure information DB 32 . By changing the attenuation level with reference to the histories, investigation-range-limited trees can be obtained which predominantly track the range investigated in the past and/or the vicinity of the failure having caused an error in the past. With reference to FIG. 17 , the calculation of an attenuation level for a service error in the Ta will be described. The investigation range limiting unit 12 counts the relations registered in the operation path history information 27 and the failure handling information 28 for a service error in the Ta. The operation path history information 27 and the failure handling information 28 have one appearance of the relation rel 02 , two appearances of the relation rel 06 , one appearance of the relation rel 13 , and two appearances of the relation rel 14 . The numbers of appearances of the other relations are zero. The investigation range limiting unit 12 obtains an importance level by adding 1 to the number of appearances of each relation. As a result, the relation rel 02 has the importance level 2 ; the relation rel 06 has the importance level 3 ; the relation rel 13 has the importance level 2 ; the relation rel 14 has the importance level 3 ; and the other relations have the importance level 1 . The investigation range limiting unit 12 defines the attenuation levels of the other relations, that is, relations that are not registered with corresponding errors in the failure information DB 32 , as α, and the value obtained by dividing α by an importance level as the attenuation level of each of the relations. As a result, the relation rel 02 has the attenuation level α/ 2 ; the relation rel 06 has the attenuation level α/ 3 ; the relation rel 13 has the attenuation level α/ 2 ; and the relation rel 14 has the attenuation level α/ 3 . FIG. 18 is an explanatory diagram of investigation-range-limited trees generated by the investigation range limiting unit 12 . The investigation range limiting unit 12 generates an investigation-range-limited tree for each detected error. In the example illustrated in FIG. 18 , the investigation range limiting unit 12 generates an investigation-range-limited tree tree 1 for a performance error detected in the CI pm 12 and generates an investigation-range-limited tree tree 2 for a delay detected in the CI va 01 . The investigation-range-limited tree tree 1 has a root in the CI pm 12 and the CI va 02 and the CI vb 02 as nodes connecting to the root. The investigation-range-limited tree tree 2 has a root in the CI va 01 and the CI va 02 and the CI pm 12 as nodes connecting to the root. The investigation-range-limited tree tree 2 further has the CI pm 12 and the CI va 03 as nodes connecting to the CI va 02 . The investigation-range-limited tree tree 2 has the CI vb 02 as a node connecting to the CI pm 12 and the CI pm 13 as a node connecting to the CI va 03 . In addition, the investigation-range-limited tree tree 2 has the CI vb 01 as a node connecting to the CI pm 11 and the CI vb 02 as a node connecting to the CI vb 01 . FIG. 19 is a flowchart describing generation of a relation class. The classification unit 61 in the network management information generating apparatus 70 extracts a combination of two errors from the error history 51 held in the failure information DB 32 (S 101 ). The classification unit 61 refers to the configuration information 21 held in the CMDB 31 , and, for the extracted two errors, checks for the presence of a relation between CIs having the errors (S 102 ). When there is a relation (YES in S 103 ), the classification unit 61 extracts this relation as a candidate for a relation class (S 104 ). After S 104 or when there is no relation (NO in S 103 ), the classification unit 61 determines whether all combinations of errors have been checked (S 105 ). When there remains a combination of errors that have not been checked (NO in S 105 ), the classification unit 61 returns to step S 101 . When all combinations of errors have been checked (YES in S 105 ), the aggregation unit 62 aggregates the candidates for a relation class (S 106 ). As a result of the aggregation, the relation class determining unit 63 extracts a relation class candidate(s) whose number of appearances is a certain number or greater (S 107 ), and outputs the extracted relation class candidate(s) (S 108 ). The process is terminated. FIG. 20 is a flowchart describing generation of investigation details. The investigation detail generating unit 65 in the network management information generating apparatus 70 extracts the failure handling information 28 from the failure information DB 32 (S 201 ). The investigation detail generating unit 65 performs abstraction of a CI in which an error has occurred and a CI causing the error, which are indicated in the failure handling information 28 , based on the types of the CIs (S 202 ). The investigation detail generating unit 65 performs abstraction of a relation included in a sorting path, which is indicated in the failure handling information 28 , based on a relation class, and registers the result as investigation details (S 203 ). The investigation detail generating unit 65 determines whether all errors indicated in the failure handling information 28 have been processed (S 204 ). When there remains an error that has not been processed (NO in S 204 ), the investigation detail generating unit 65 returns to step S 202 . When all the errors have been processed (YES in S 204 ), the investigation detail generating unit 65 outputs the investigation details (S 205 ). The process is terminated. As has been described above, the network management supporting system, the network management supporting apparatus, and the network management supporting method according to the second embodiment generate a relation class that is abstraction of the propagating direction of an error, based on the types of components, from configuration information of a network and error history information. In addition, the disclosed system, apparatus, and method classify the relation between components of the system into a relation class, and, when an error occurs, based on relation classes, narrows down the range in which a failure causing the error has occurred by tracking the components. Narrowing down the possible points of a failure by using relation classes in this manner does not depend on the configuration of the network system and is thus highly versatile. Therefore, such a technique is applicable to a newly constructed network system or even to a network system having a changed configuration. Even for trouble investigation in a large-scale network system or a virtual environment, the disclosed art may support the trouble investigation by narrowing down the possible points of a failure. More specifically, the disclosed art is applicable to a virtual network including, as components, physical machines, virtual machines, and services. By applying relation classes to an error handling history in the past, the range to be tracked when an error occurs may be obtained as an investigation range. In this way, propagation of the error may be tracked without depending on the actual configuration, and the point of a failure may be estimated. The system, apparatus, and method disclosed in the embodiments are only examples, and the configurations and operations may be changed properly for implementation. For example, the apparatus disclosed in the second embodiment may have the relation class applying unit 11 , the investigation range limiting unit 12 , and the failure point candidate estimating unit 13 distributed over a network system and may be implemented as a failure point estimation system. The network management information generating apparatus 70 , the failure point estimating apparatus 30 , the CMDB 31 , and the failure information DB 32 may be implemented as an apparatus including these elements enclosed in a single housing. The CMDB 31 and the failure information DB 32 may be shared with other apparatuses or systems. The processes on the flowcharts disclosed in the second embodiment may be added and/or deleted, or the order of the processes may be changed properly. All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the embodiment and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a illustrating of the superiority and inferiority of the embodiment. Although the embodiment of the present invention has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

An apparatus for managing a network system including a plurality of components, the apparatus includes a memory that stores component type data of each component of the plurality of components, component relation data including relation information indicating a pair of components related to each other in the network system and error history data including error information of respective error components in the plurality of components. The apparatus includes a processor that executes a procedure including extracting a pair of component type data as a relation class candidate on the basis of the component type data of a pair of error components indicated by the error information in the error history data, the pair of error components being indicated by the relation information.

BACKGROUND OF THE INVENTION A wide variety of rigid metal prostheses, such as bone plates, intramedullary rods and femoral nails, are used in the fixation of bone fractures. A potential problem associated with the use of rigid bone prostheses for fracture fixation is referred to in the art as stress-shielding. As bone remodeling takes place in the region of the fracture, stresses exerted on the healing bone are carried primarily by the prosthesis rather than by the bone in the fracture region. This stress-shielding can be the cause of significant bone resorption, with consequent reduction of strength of the bone in the region of the healed fracture. Shielding of bending stresses from bone undergoing remodeling is believed to be particularly deleterious. See Bradley, G. W. et al., "Effects of Flexural Rigidity of Plates on Bone Healing", Jour. Bone and Joint Surg., Vol. 61-A, No. 6, pp. 866-872 (September 1979) and Woo, S. L-Y et al., "A Comparison of Cortical Bone Atrophy Secondary to Fixation with Plates with Large Differences in Bending Stiffness", Jour. Bone and Joint Surg., Vol. 58-A, No. 2, pp. 190-195 (March 1976). The use of bone prostheses made of materials that are substantially less rigid than conventional surgical implant alloys has been proposed in order to alleviate problems arising from stress-shielding. One class of materials of reduced rigidity consists of non-absorbable synthetic polymers reinforced with inorganic fibers. However, the use of such materials sacrifices the excellent initial stabilization provided by a rigid prosthesis, which insures the maintenance of a proper alignment of bone segments during the early stages of healing. U.S. Pat. No. 2,987,062 discloses an orthopedic bone fracture clamp adapted to be wrapped around a fractured bone. The clamp comprises two metallic bands directly connected at one pair of ends and joined by a link of absorbable catgut at the other pair of ends. The assembly of bands and absorbable link is placed under tension so as to hold the fractured bone together. After implantation of the assembly in the patient the link begins to be absorbed. Eventually the link fails and the clamping pressure on the bone is terminated, thereby, according to the patent, obviating the deleterious effects of continued pressure on the bone and eliminating the need for a second surgical operation to remove the clamp. However, the clamping pressure applied to the healing bone would not tend to decrease gradually or progressively with time after implantation. Instead, it would tend to drop in one full step at the moment of failure of the link from near the initial clamping pressure to zero. The use of a bone plate having a rigidity that gradually decreases with time after implantation has been proposed by Parsons, J. R. et al., "A Variable Stiffness, Absorbable Bone Plate", presented at the Fifth Annual Meeting of the Society for Biomaterials, Clemson, South Carolina, April 28-May 1, 1979. The bone plate proposed by Parsons et al. is made of a material consisting of continuous carbon fibers embedded in a resorbable matrix of polylactic acid polymer. However, the initial rigidity of this plate is only 20% to 50% that of conventional stainless steel bone plates, and the rigidity decreases by only 10% after six weeks of implantation. Also, the carbon fibers are dispersed throughout the tissue of the patient after absorption of the polylactic acid matrix. SUMMARY OF THE INVENTION A novel bone prosthesis for use in healing a bone fracture has now been invented comprising a strong, rigid, biologically non-absorbable structural member and a biologically absorbable element adapted to be held under compression against said structural member when said prosthesis is secured to said bone, so that stress is transmitted from said bone through said element to said structural member, whereby the stress transmitted to said prosthesis gradually decreases with time during the healing of said bone as said element is absorbed. The structural member is preferably made of metal, but may also be made of a ceramic, carbonaceous or other material. The biologically absorbable element is preferably made of a synthetic polymeric material, such as a hydroxymethacrylate polymer, a polypeptide, polyglycolic acid, polylactic acid or a copolymer of polyglycolic acid and polylactic acid, but may also be made of, e.g., a ceramic material such as hydroxyapatite or tricalcium phosphate or a naturally-occurring polymeric material. The structural member of the novel prosthesis of the invention may be, e.g., a bone plate, intramedullary rod or hip nail. The effective overall rigidity of the prosthesis, as experienced by the healing bone, varies progressively with time after implantation, with stresses transmitted through the healing bone being gradually shifted from the prosthesis to the bone in the fracture region. The rate of decline of said effective rigidity as a function of time can be controlled by proper choice of the material (chemical composition, porosity, molecular weight, degree of crystallinity, monomeric ratio in copolymer, etc.) used for the biologically absorbable element. A prosthesis of the invention may be designed in such a manner that its effective overall rigidity varies progressively after implantation from almost that of the rigid structural member to zero, with the probability of having to perform a subsequent surgical operation to remove the non-absorbable portion of the prosthesis being substantially lower than when said portion is implanted alone. DETAILED DESCRIPTION OF THE INVENTION The invention will be described in detail with reference to certain preferred embodiments thereof. Reference to these embodiments does not limit the scope of the invention, which is limited only by the scope of the claims. In the drawings: FIG. 1 is a front sectional view of a first embodiment of the invention, a bone plate provided with a continuous biologically absorbable coating; FIG. 2 is a front sectional view of a second embodiment of the invention, a bone plate provided with a plurality of biologically absorbable spacers; FIG. 3 is a front sectional view of a third embodiment of the invention, a bone plate provided with a plurality of biologically absorbable washers; FIG. 4 is a front sectional view of a fourth embodiment of the invention, a bone plate provided with a plurality of biologically absorbable gaskets and non-absorbable sleeves; FIG. 5 is a front sectional view of a fifth embodiment of the invention, an intramedullary rod provided with a continuous biologically absorbable coating; and FIG. 6 is sectional view taken along line 6--6 of FIG. 5. FIG. 1 is a front sectional view of a first embodiment of the invention, bone prosthesis 1, secured to bone fragments 8 and 9 so as to effect the healing of a fracture between said bone fragments represented by fracture line F. Prosthesis 1 comprises a metallic structural member 2 and a biologically absorbable element 3. Structural member 2 is a conventional bone plate. Prosthesis 1 is secured to the bone by means of a plurality of conventional metallic bone screws 4 to 7 fitted through a plurality of circular apertures in member 2. Structural member 2 and bone screws 4 to 7 are made of a strong, rigid, biologically non-absorbable surgical implant alloy such as the cobalt-chromium-molybdenum alloy manufactured and sold under the trademark Vitallium (Howmedica, Inc.; New York, New York) or 316L stainless steel. Element 3 is a biologically absorbable continuous coating molded to the bottom face of member 2 and having the same length and width as said face. Element 3 is typically from about 0.1 mm. to about 1 mm. in thickness. The absorbable coating is provided with a plurality of circular bone screw apertures coinciding with those in member 2. Element 3 is made of a synthetic polymeric material, preferably polyglycolic acid, polylactic acid or a polyglycolic acid:polylactic acid copolymer. As can be seen in FIG. 1, elements 3 is held under compression between structural member 2 and bone fragments 8 and 9 when prosthesis 1 is secured to said fragments by means of bone screws 4 to 7. The face of element 3 held adjacent to the bone fragments may be textured to allow for access of blood to the bone. Immediately after implantation, virtually all of the stresses transmitted between bone fragments 8 and 9 are transmitted through element 3 and carried by member 2, since they cannot be transmitted across the fracture line F. The rigidity of prosthesis 1 experienced by the bone fragments immediately after fixation is almost that of a conventional rigid metallic bone plate. As time passes after implantation, two phenomena occur simultaneously. First, the fracture between fragments 8 and 9 begins to heal, thus reducing the need for stress-shielding. Second, element 3 is gradually absorbed by the bodily fluids and is thus gradually weakened. As these two phenomena occur, the pathway of stress transmission between bone fragments 8 and 9 is gradually shifted so that with passing time progressively more stress is transmitted directly through the healing bone in the region of original fracture line F and progressively less stress is transmitted through prosthesis 1. Finally, as the absorption of element 3 nears completion, virtually all of the stresses are carried by the healed bone itself; the probability of having to perform a subsequent surgical operation to remove the non-absorbable portion of the prosthesis is substantially lower than when said portion is implanted by itself without element 3. Alternate designs for biologically absorbable elements for use with structural member 2 and screws 4 to 7 are shown in FIGS. 2, 3 and 4. In FIG. 2, the continuous coating 3 of FIG. 1 has been replaced by a plurality of discrete, generally rectangular biologically absorbable spacers 11 to 13 molded to the bottom face of structural member 2. The width of said spacers, i.e. the dimension extending perpendicularly to the plane of FIG. 2, is the same as the width of the bottom face of member 2. In FIG. 3, the continuous coating 3 of FIG. 1 has been replaced by a plurality of biologically absorbable washers 21 to 24 for screws 4 to 7. Washers 21 to 24 are not molded to structural member 2, and are separable therefrom when the prosthesis of FIG. 3 is not in use. In FIG. 4, the continuous coating 3 of FIG. 1 has been replaced by a plurality of biologically absorbable gaskets 31 to 34 for screws 4 to 7. Additionally, the prosthesis contains a plurality of non-absorbable polymeric, e.g. polyethylene, sleeves 41 to 44 located within the bone screw apertures of structural member 2 to prevent fretting of bone screws 4 to 7 against member 2. Gaskets 31 to 34 and sleeves 41 to 44 are separable from member 2 when the prosthesis of FIG. 4 is not in use. FIG. 5 is a front sectional view of a fifth embodiment of the invention, bone prosthesis 101, which has been driven into the medullary canal 110 of a fractured bone so as to effect the healing of a fracture, represented by fracture line L, between bone fragments 108 and 109. Prosthesis 101 comprises a metallic structural member 102, which is a conventional intramedullary rod, and a biologically absorbable element 103, which is a continuous coating molded to the exterior surface of member 102. As can be seen in FIG. 6, both member 102 and element 103 are circular in transverse cross-section, subtending an angle of about 270°. Structural member 102 is made of a strong, rigid, biologically non-absorbable surgical implant alloy such as the cobalt-chromium-molybdenum alloy manufactured and sold under the trademark Vitallium (Howmedica, Inc.; New York, New York). Element 103 is made of a synthetic polymeric material, preferably polyglycolic acid, polylactic acid or a polyglycolic acid:polylactic acid copolymer. As can be seen in FIGS. 5 and 6, element 103 is held under compression between structural member 102 and bone fragments 108 and 109 when prosthesis 101 is driven into the medullary canal of the fractured bone. As bone healing and absorption of element 103 occur simultaneously after implantation, stress transmission is gradually shifted from prosthesis 101 to the bone in the region of original fracture line L in an analogous manner as described above with regard to the prostheses of FIGS. 1 to 4. Again, the probability of having to perform a subsequent surgical operation to remove structural member 102 is substantially reduced.

A novel bone prosthesis for use in healing a bone fracture is disclosed comprising a strong, rigid non-absorbable structural member and a biologically absorbable element held in use under compression against the structural member. Use of the novel prosthesis combines an excellent initial stabilization of the fixed fracture with a gradual shifting of stress-bearing from the prosthesis to the bone in the fracture region as the fracture heals. Thus, problems associated with stress-shielding during healing are alleviated. The structural member may be, e.g., a bone plate, intramedullary rod or hip nail.

FIELD OF THE INVENTION [0001] The present invention relates generally to tools, methods and systems for constructing cast structures including walls, ceilings, columns and beams, and more specifically to tools, methods and systems for accurate construction of multilayer cast structures. BACKGROUND OF THE INVENTION [0002] There are many methods and systems of constructing walls in the construction industry. Some methods involve the connection of pre-fabricated walls. Other methods involve time-consuming for laying of brick walls. [0003] Cast structures, e.g., walls, can be constructed by placing two spaced apart panels in parallel to each other, affixing said panels in their positions by means of suitable support means, pouring unhardened concrete into the space between said panels and allowing the concrete to cure. The panels may be either removed or remain in their place, and in the latter case, they may be designed to serve useful functions, such as thermal insulation. The resultant wall may be coated with plaster and/or stone. [0004] IL 124209 describes a building method using a plurality of framework elements for engaging and retaining vertical plates, and at least one sheet of rigid foamed insulation. [0005] US 2001/0027631 describes the construction of a concrete structure, using two opposed longitudinally-extending side panels, with a web member partially disposed within each of said panels, and connectors placed between the side panels for connecting the web members to each other. [0006] US 2004/0035073 discloses a three-dimensional construction module supported by mesh layers oriented transversally and longitudinally. [0007] One prior art method of constructing a standard cast wall, which may be plaster and/or stone coated and thermally insulated, requires many stages. This general methodology is prevalent in Israel and in the Middle East, in forming outer walls which have at least one outer layer of “Jerusalem limestone”. These many stages, performed by several different professional workmen, include: formwork preparation, metal reinforcement preparation, concrete casting, form dismantling, scafolds erection, waterproofing, applying thermal insulation, supporting the external coating stones by anchoring metal nets, stones cutting, stone drilling, stone laying, cementing the spaces between the stones, wall-face planarization, scaffolds dismantling, exterior wall cleaning, interior wall cleaning, thermal insulation preparation, (building an additional thin insulation brick wall while placing thermal insulation panels in between the two walls, perimeter construction, interior side plastering (with 3 plaster layers), perimeter dismantling, wall cleaning, and finally, costume-made window and door manufacturing and assembling. This is a stone-coated wall on an external side and plaster-coated on an internal side. Other kinds of walls may be coated on both sides homogeneously either by plaster or by stones, or might be partially or fully uncoated. This type of wall construction is physically very difficult and requires a major logistic effort prior to, during and after the construction process. Not only is this current methodology time-consuming, but is also very expensive. For instance, it requires the transfer of all the large construction equipment, such as plywood, heavy metal forms, large and heavy metal nets, to the construction site using big trucks and heavy duty cranes. [0008] In addition to wall construction, prior art method of construction of a standard cast ceiling, which may be plaster coated and possibly thermally insolated, requires many stages as well. These stages, also performed by several different professional workmen, include: formwork preparation, metal reinforcement, concrete casting, form dismantling, ceiling face planarization, scaffolds erection, interior side plastering with 3 layers plaster, scaffolds dismantling, and finally cleaning. [0009] Furthermore, prior art method of constructing columns and beams requires many stages as well, similar to those performed in building walls and ceilings. In other words, the cast structures, traditionally built in many stages, might be vertical (e.g., walls, and columns), horizontal (e.g., ceilings and beams), or diagonal (e.g., staircases and inclined elements). The multiple stage production of all these structures bears similar disadvantages. Moreover, current construction methods create a lot of dust, ground material and lead to both airborne and solid pollution. SUMMARY OF THE INVENTION [0010] The invention relates to the production of cast structures which are uncoated, single-sided coated (e.g., a ceiling and an existing wall stone coating) and multiple-sided coated (e.g. walls, columns and beams), for example, a prevalent double-sided coated wall with an internal face and an external face that are coated with plaster and stones, respectively. The casting process is based on a unique method for setting up a support frame and affixing two spaced apart typically parallel boards which constitute the desired final coatings. The other contents of the wall (e.g., reinforcement rods, thermal insulation panel, service conduits and sealants) can be disposed between the two said boards and the concrete is finally poured into the space between the boards. Following the hardening of the concrete, a cast structure is formed, which is optionally reinforced, thermally insulated and sealed, with the desired coatings provided on its outer surfaces. [0011] Thus, board coatings, such as plaster coatings, which are traditionally applied on the hardened concrete upon completion of the casting stage, serve, according to the invention, in place of conventional formwork assembled at the pre-casting stage. [0012] The method, which involves the use of special connectors and construction elements for supporting, assembling and holding the boards, can also be applied for producing single-sided coated or uncoated cast structure, in which case at least one of the boards used is a temporary board (e.g., a plywood board). Following the concrete hardening, the temporary board or boards are removed to obtain an uncoated or one-sided coated cast structure. [0013] Accordingly, the term “board”, as used herein, is meant to include any permanently or temporarily used (planar or curved) board. The term “coating board”, as used herein, is meant to include any permanently used board for coating the cast structure, e.g., a plaster board, a cement board and a board made of stones. The term “temporary board”, as used herein, is meant to include any temporarily used board, e.g., a plywood board (preferably coated with formica), a plastic board and a metal sheet. [0014] As noted above, a first aspect of the invention relates to a device useful in the production of the cast structures, and more specifically, a device for supporting, assembling and affixing two essentially parallel, spaced apart boards in place relative to each other at the stage prior to concrete pouring. [0015] Accordingly, the invention provides a connector for a pair of opposed, spaced apart boards, said connector comprising two opposing ends and an elongate spacer extending therebetween, having at least one substantially horizontal locator member aligned perpendicular to the longitudinal axis of said elongate spacer, said horizontal locator being preferably in the form of a loop, and at least one substantially vertical locator member, extending from said spacer substantially perpendicularly to both the longitudinal axis of said spacer and to said horizontal locator member, said vertical locator being preferably in the form of a pair of cresses or a loop, wherein each of the two opposing ends of said connector is independently selected from the group consisting of: a. an end suitable for engaging coating boards other than stones board (for simplicity this end is referred to herein as a “plaster head”), said plaster head comprising a plate designed for back supporting said coating board, said plate having a rear side facing said elongate spacer and a front side from which coupling means are longitudinally extended, said means being preferably in the form of a conic head screw, wherein a groove and an expandable rim are preferably positioned between said front side and said coupling means, such that altering the position of said coupling means (e.g. screwdriving said screw) results in the expansion of said rim, b. an end suitable for engaging a stones board (for simplicity this end is referred to herein as a “stone head”), said stone head being preferably wider than said elongate spacer and having an upper face and a lower face, with at least one pin extending vertically from both faces of said end, such that said pin is substantially parallel to the vertical locator (e.g., the pair of cresses), wherein said pin preferably has sharp ends capable of being inserted into corresponding holes in the engaged stones, c. an end suitable for engaging a temporary board, (for simplicity this end is referred to herein as a “concrete head”), said concrete head preferably being thicker than said elongate spacer and having coupling means (e.g., a screw) extending longitudinally therefrom. [0019] The length of said elongate spacer of said connector, which is preferably made of plastic, is in the range from to 2000 mm (more preferably from 150 to 250 mm) corresponds to the thickness of the cast structure. [0020] The diameter of the horizontal loop and similarly, the distance between the pair of cresses extending vertically from the elongate spacer is from 5 to 100 mm, preferably from 10 to 30 mm. Accordingly, the horizontal loop and the pair of cresses can serve as locator for reinforcement rods, which are intended to be threaded therein. [0021] Regarding the plaster head, the useful function served by the expansion of the rim, positioned near the outer surface of the coating board, is that its diameter becomes substantially larger than the diameter of the coating board's hole, thus locking said coating board to said cast structure. [0022] Regarding the stone head, the diameter of the vertical pin provided at the stone head, which pin is typically made of steel, is from 2 to 15 mm (preferably 3 to 5 mm), and it extends by 5 to 50 mm (typically 10-15 mm) from the upper and lower faces of said stone head. The diameter of the plaster head and the concrete head is from 5 to 50 mm (preferably from 8 to 12 mm). [0023] As noted above, the connectors are used for affixing two essentially parallel, spaced apart boards in place relative to each other, defining a space between the boards, into which concrete is to be poured. The connectors, which are provided with a plaster head or a concrete head, are held to the respective boards (e.g., coating boards such as plaster or cement board, and temporary boards such as plywood boards) by means of a plate element (for simplicity this plate referred to herein as a “connector holder”). The plate, which is typically planar and preferably rectangular in shape, is attached to the outer side of the board (the side which is not facing the concrete receiving-space), thereby back supporting the board. The connector holder, e.g., the plate, has a hole similar to that of a keyhole shape, said hole being preferably centrally located in said plate, said hole comprising a first region with a first diameter and a second region with a second diameter, with the first diameter being smaller than the diameter of the head of the coupling member (e.g., the screw) provided in the plaster head or in the concrete head, said first region being preferably provided with reinforcement bend at its margin, and wherein the second diameter being larger than the diameter of the head of said coupling members designed for quick engaging and disengaging said coupling member of said plaster head and concrete head of said connectors. [0024] The dimensions of said connector holder, which is preferably in the form of a thin rectangular metal sheet, are 50-500 mm by 50-700 mm (preferably 100-300 mm by 100-300 mm), and thickness of about 0.1 to 10 mm (preferably 1 to 3 mm). Regarding the substantially centrally located hole of said plate, the diameter of its first region is from 3-25 mm (preferably 4-12 mm) and the diameter of its second region is from 6-60 mm (preferably 10-30 mm). A kit comprising the connector and the connector holder forms another aspect of the invention. [0025] Another aspect of the invention relates to another kind of device useful in the production of a cast structure, and more specifically, a device for producing a coated ceiling, which is coated by a coating board such as plaster board or stones board. Accordingly, the invention provides a connector ( 480 , 490 ) for supporting said coating board, said connector comprising two opposing ends and an elongate spacer extending therebetween ( 481 ), wherein one end ( 482 ), designed to be anchored in the ceiling's concrete, is larger than said elongate spacer, and another end consisting of a plaster head or a stone head described above. [0026] Another aspect of the invention relates to another kind of device useful in stone coating an existing wall. Accordingly, the invention provides a connector ( 4100 ) comprising two opposing ends and an elongate spacer extending therebetween ( 4102 ), wherein one end ( 4101 ) consisting of said stone head and another end ( 4103 ) consisting of a “C-clamp” head ( 4106 ) in the form of a ring with a “V” shape opening in the perimeter of said ring ( 4105 ), designed to be clamped on the net anchored to said existing wall. [0027] Another aspect of the invention relates to another kind of device useful in the production of a cast structure, and more specifically, a device for supporting, assembling and affixing two adjacent stones boards typically none co-planar and often orthogonal to one another (for simplicity this connector is referred to herein as “stone corner connector”). Said stone corner connector (SCC) comprises a body and two pins, where said body, having upper and lower faces, comprises two ends and an elongate spacer extending therebetween, where each of the two connector's ends has a pin extending substantially perpendicularly from its faces and essentially parallel to one another, each pin optionally has sharp ends capable of being inserted into corresponding holes in the engaged stones, said elongate spacer has a cress extending substantially upward and an essentially horizontal loop extending laterally, and finally, said body has at least one hole for an engaging element used to engage it to a support frame. [0028] The length of said stone corner connector, typically made of polymeric material such as plastic, is between 20 and 1000 mm (typically 50 to 300 mm), the thickness of said connector, is between 1 and 100 mm (typically 5 to 30 mm), the diameter of each pin, which pin is typically made of steel, and the diameter of said cress is from 2 to 15 mm (preferably 3 to 5 mm), and they extend by 5 to 50 mm (typically 10 to 15 mm) from their faces, and the diameter of the horizontal loop is from 1 to 100 mm, preferably from 2 to 30 mm. Accordingly, the essentially horizontal loop and the essentially vertical cress can serve as locators for reinforcement rod and rim, respectively, which are intended to be threaded therein. [0029] A further aspect of the invention relates to a method for producing cast structures, comprising: a. assembling at least a pair of opposed, substantially parallel and spaced apart (planar or curved) boards, wherein each board is selected from the group consisting of coating boards and temporary boards, thus defining a filler-receiving-space between the inner faces of said pair of boards, wherein said assembling comprises affixing said pair of boards in place relative to one another by connecting them by means of connectors and holding said connectors by means of connector holders in the form of plates placed on the outer face of each said board, preferably forming an array consisting of rows and columns of said connectors in said filler-receiving-space, wherein each connector comprises an elongate spacer having at least one substantially horizontal locator member aligned perpendicular to the longitudinal axis of said elongate spacer, said horizontal locator being preferably in the form of a loop, such that said loop is normally horizontally aligned in the filler-receiving-space between said pair of boards, and at least one substantially vertical locator member, extending upwardly from said spacer substantially perpendicular to both the longitudinal axis of said spacer and to said horizontal locator member, said vertical locator being preferably in the form of a pair of cresses or a loop, such that said pair of cresses or loop is essentially parallel to said boards, b. optionally threading horizontal and vertical reinforcement rods through said horizontally and vertically aligned locators of said array of connectors, respectively; c. optionally disposing in said filler-receiving-space additional contents (e.g., insulation panel, service conduits and sealants) of said structure, d. pouring filler into the concrete receiving space, and allowing the filler to cure, e. Optionally removing said connector holders, and when temporary board is used, then removing said connector holders, said temporary board and said coupling members of the corresponding concrete head of each said connector. [0035] Preferably, the step of assembling the boards is preceded by affixing a vertical support frame, comprising vertical and, when necessary, diagonal profiles (e.g., right-angle profiles), mutually connected and optionally anchored to the floor. The method, set out above, may further comprise the step of disposing any additional contents of said cast structure (e.g., thermal insulation panels, service conduits and sealants) in the space between the pair of boards prior to filler addition. [0036] There is also provided, according to one embodiment of the present invention, a coated wall comprising: a. At least one pair of spaced apart, typically parallel, boards, wherein at least one board constitutes the desired final coating board made of e.g. plaster board, stones board or cement board, b. A plurality of substantially horizontal connectors placed between said pair of boards and affixing said boards in place relative to one another, wherein each of said horizontal connectors comprises a pair of elements (locators) for positioning reinforcement rods (e.g. metal rods), said locators being oriented in planes which are perpendicular to one another, said connectors being preferably in the form described in detail above; c. Optionally, reinforcement rods (e.g. metal rods) disposed between said boards forming a grid structure held in place by means of said connectors; d. Optionally, sealant and/or other contents of said wall (e.g. insulation panels and service conduits) being placed between said boards, e. Optionally, filler adapted to be poured into the gap between said boards and to set therein. [0042] In those cases where an opening of any shape needs to be provided in the cast structure, e.g. a rectangular window, then the invention further comprises assembling a frame of boards (e.g. marble stones), each being orthogonal to said coating boards and covering the thickness of the cast structure and a lintel, and casting a beam (preferably with reinforcement rods) on top of them, and when necessary, establishing an access for filler beneath the opening (e.g. the window) using at least one pipe serving as a funnel in order to fill the entire space beneath said opening by said filler. [0043] Another aspect of the invention relates to a method for producing suspended (planar or curved) cast structures, (e.g., a ceiling and/or a beam) comprising: a. affixing a substantially horizontal support frame (planar or curved), according to the shape of the desired cast structure, b. placing on said support frame a (planar or curved) coating board, c. engaging essentially vertically to said board a plurality of connectors and connector holders described above to said coating board, d. affixing an additional typically vertical support frame, when side coating is required (e.g., in a coated beam), similar to that used for walls, and tangent to said structure, and engaging typically horizontally a plurality of connectors and connector holders when required, e. optionally disposing one or more components selected from the group consisting of reinforcement rods and nets, insulated panel, bricks and service conduits of said suspended cast structure, and f. Pouring filler, and after hardening, optionally removing said support frame, and said connector holders and screwdriving the engaging elements. [0050] Another aspect of the invention relates to a method of applying a stone coating on an existing wall, comprising: a. anchoring to said wall a net, preferably in the form of a grid of metal rods, b. assembling a stones board using stone net connectors by means of clipping the net heads of said connectors onto said net, and maintaining filler-receiving-space between said wall and said stones board, and c. Pouring filler in said filler-receiving-space. [0054] Another aspect of the invention relates to a kit of elements useful as support frames in the production of the cast structures set forth above, including erected structures (e.g., walls and columns) and suspended structures (e.g., ceilings and beams), said kit comprising: a. a right-angled profile element ( 530 ) in the form of a metal sheet which is bent along its length at an essentially right angle, wherein each of the two parts which are perpendicular to one another has a series of holes ( 531 ) along its length, wherein said holes are preferably evenly spaced; b. a set of longitudinal hollow profiles, each in the form of rectangular parallelepiped in which two opposed lateral edges are open, (for simplicity referred to herein as “hollow profiles”), wherein each individual profile has a cross section which is dimensionally different from the cross section of other profiles in the set, such that said set is capable of being arranged in a first arrangement in which the individual profiles are entirely inserted one inside the other when said set needs to be relocated, shipped and stored, and in a second arrangement in which the profiles are partially inserted one inside the other, when said set is in use; c. A profile gripping element 520 (for simplicity referred to herein as a “profile gripper”) for engaging the connector described above to said right-angle profile ( 530 ), said profile gripper comprising a first planar member and in connection therewith at an essentially right angle thereto a second member consisting of two parallel thin plates, said first member comprising an aperture which is preferably located at proximity to the intersection of said first member and one of said thin plates, wherein said parallel plates are spaced apart such that the gap therebetween corresponds to the thickness of a perforated part of said right-angled profile element ( 530 ) said aperature is a hole similar to that of a keyhole shape, comprising two kinds of holes, where one kind is circular and larger than the head of the connector's engaging element (e.g. the connector's screw), such hole is desiged for quick engaging and disengaging said coupling means of said plaster head and concrete head of said connector, and a second kind of holes, one above and one beneath the first kind of hole, such holes are elongate and smaller than said head of said coupling element (e.g. connector's screw head), such second kind of holes are designed for enabling gripping said right-angle profile either from its right side of from its left side, while having the weight of said profile gripper assisting and ensuring its locking effect to the engaging element; d. a wedge insertable in the gap formed between a pair of said profiles, when said profiles are in said second arrangement, said wedge being positioned between the inner face of the lower base of the wider profile and the outer face of the lower base of the narrower profile, thereby attaching the upper bases of said profiles to one another; and e. a flexible cable, preferably having two solid, (e.g. T-shaped), heads at its ends, such that each heads is capable of being inserted through a hole of said right-angle profiles and cancatinate each two adjacent profiles by essentially two typical spaced apart cable spacers, thus typically evenly spacing apart said profiles when used, and keeping them both cancatinated and stocked together when orderly relocated, shipped and stored. [0060] The right-angle profile, which is preferably made of a metal sheet, is 10-10000 mm by 10-100 mm (preferably 300-5000 mm by 30-60 mm); [0061] Said profile gripper is typically made of sheetmetal, and the dimensions of each of its members is 20-200 mm by 20-200 mm (preferably 30-100 mm by 30-100 mm); [0062] The set of said hollow profiles, typically rectangular metal, of dimensions 10-200 mm by 10-200 mm (preferably 20-100 mm by 20-100 m); [0063] The wedge is typically made of 8-100 mm by 8-100 mm by 8-100 mm steel; [0064] The cable, typically made of steel, is 20-200 mm long and 0.5-10 mm (usually 1-3 mm) thick. [0065] Another aspect of the invention relates to a method for using said support frame kit for establishing support systems for the construction of cast structures by: 1. assembling the coating boards for erected structures (e.g., walls and columns) which is usually preceded by affixing a series of spaced apart (e.g. by 120 cm) vertical support profiles, comprising of vertical and, when necessary, diagonal right-angle profiles, mutually connected and preferably anchored to the floor, said cast structure is usually fastened to said vertical support profiles by means of the profile grippers; and, 2. assembling the coating boards for suspended structures (e.g., ceilings and beams), which is usually preceded by establishing essentially a horizontal support frame including: a. disposing hollow profiles (serving as support frame beams), typically parallel to one another and spaced apart (e.g., by 1 meter), on top of standard construction jacks, e.g. narrower profiles partially inserted into wider ones, where each set of overlapping parts are optionally commonly supported by a jack, and where a wedge is inserted between them at their bottom faces in order to insure that their upper parts are mutually attached to one another, or alternatively, supporting said narrower hollow profile by a jack near said overlapping regions and having the wider profile suspended on the narrower one, b. disposing right-angle profiles on top of said hollow profiles, spaced apart (e.g., by 10 cm) by at least two typically identical cable spacers connecting each two adjacent profiles, and having said profiles oriented, for example at a v-shape (for maximizing the support area of the coating board disposed on top of them), said right-angle profile partially overlaps longitudinally an adjacent one extended longitudinally, where each pair of overlapping parts are supported by a hollow profile. [0070] Another aspect of the invention relates to a method of using said support frame kit for supporting wall-to-ceiling connection, which includes the following steps used, for instance, for stone-plaster wall when connected to plaster coated ceiling: a. connecting horizontally a right-angle profile to said vertical profiles such that one part of this profile is essentially parallel to said stones board while its perpendicular counterpart is perpendicular to said stones board and pointing away from it (for simplicity this horizontal profile is referred to as a “profile rail”), said profile rail is positioned slightly above the top aspect of the ceiling while leaving an opening space between said profile rail and said ceiling's coating plaster board, such opening is left for enabling reinforcement rods and concrete to pass from the ceiling onto the wall, while previously, said vertical profiles are covered by solid sleeves (pipes) at the height of the ceiling, along its thickness, to protect said vertical profiles from being locked by the ceiling's fresh concrete, b. adding an additional row of stones on top of the wall's stones board (for simplicity this row of stones is referred to as a “stone rail”), such stone rail is destined to both prevent the fresh ceiling's concrete from spilling over the wall, and ultimately coat the side of the ceiling, c. Connecting said profile rail to said stone rail using stone-plaster connectors together with profile grippers for gripping said profile rail to withstand the weight of the ceiling's fresh concrete. [0074] Another aspect of the invention relates to a method of using the support frame kit for supporting wall-to-wall connections, which includes the support of each of the two sides of the wall-to-wall right-angle connection, for instance, by said right-angle profile, and fastening them either by metal wires, or by plaster-plaster connector, for instance, or in some cases, e.g. when stone-plaster walls are mutually connected, then stone corner connector (SCC) can be used for the external stone corner, while the internal corner can be supported by the regular connectors, including their corresponding connector holders, provided that these connectors are located close enough to the edge of the internal corner and a narrow connector holder 510 a is used. [0075] In summary, the present invention deals with an ergonomic strategy and a system of connectors and a kit of elements which enable the performance of all the construction stages of cast structures in one consolidated stage by one single specialist. It is designed to be performed substantially quicker than the prevalent construction methods while saving a lot of human motion and energy. The entire assembling process, according to the invention, can be performed from one side of the cast structure, e.g. the inner side of a building, and it creates almost no residues of construction material. It enables the precise fitting of the openings in a cast structure to the previously manufactured lintels of windows, doors and trellises and not visa versa, thus avoiding the need for custom made production of each window, door and trellises for each opening. The final result of this method is a constructed (planar or curved) unit having the same basic components of the one obtained by the prevalent construction methods, having the advantage of most said coating boards being dis-assembelable and re-assemblable for possible future changes. The construction process here is substantially less time consuming and with less pollution and less manpower—particularly professional expensive one. Therefore, it involves considerably lower costs compare to that of the prevalent construction methods. BRIEF DESCRIPTION OF THE FIGURES [0076] In the drawings: [0077] FIGS. 1A-1B show perspective front and rear views of a double-sided stone-plaster wall, in accordance with some embodiments of the present invention; [0078] FIGS. 2A-2B show perspective front and rear views of various categories of walls and ceilings, in accordance with some embodiments of the present invention; [0079] FIGS. 3A-3B show perspective front and rear views of a multi-sided columns and beams, in accordance with some embodiments of the present invention; [0080] FIG. 4 shows perspective views of various connectors for constructing cast structures, in accordance with some embodiments of the present invention; [0081] FIG. 5 shows construction elements for constructing cast structures, in accordance with some embodiments of the present invention; [0082] FIG. 6 is a simplified flow chart of a method for constructing a double-sided stone-plaster coated wall; in accordance with some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0083] The current invention concerns a construction method of cast structures such as walls, ceilings, columns and beams, including devices therefore. More specifically, the invention employs ergonomic strategy for fast and efficient construction of cast structures, using appropriate connectors and tools. These structures are coated with a plaster board and/or stones, or partially or fully uncoated. They optionally include reinforcement grids of horizontal and vertical metal rods, thermal insulation panels, sealants, service conduits and apertures for windows and/or doors. They are typically supported by support frames comprise of vertical, diagonal and, if required, horizontal profiles. [0084] The construction method, according to the invention, is aimed at producing various categories of walls, ceilings, columns and beams as described below: a. stone-plaster wall—a stone coated wall typically on the outside and plaster board typically on the inside, b. plaster-plaster wall—a plaster coated wall on both sides, c. stone-stone wall—a stone-coated wall on both sides, d. stone-concrete wall—a stone-coated wall on one side whereas the other side is uncoated, e. plaster-concrete wall—a plaster coated wall on one side whereas the other side is uncoated, f. concrete-concrete wall—fully uncoated wall, g. plaster coated ceiling, h. stone coated ceiling, i. Partially or fully uncoated ceiling. [0094] Reference is now made to FIGS. 1A-1B , which show perspective front and rear views of the double-sided stone-plaster wall 100 , in accordance with some embodiments of the present invention. Wall 100 comprises an internal surface 130 and an external surface 140 . Usually, the external surface may be exposed to the environment, and the internal surface is, in some cases, within a building. [0095] External surface 140 is coated with stones 101 and the internal surface comprises, for example, a plaster board 102 . The wall may be vertically supported by one or more support frames 103 . Disposed between surfaces 140 and 130 , there may optionally be a thermal insulation panel 106 , which may be attached to plaster board 102 . In addition, stone-plaster connectors (SPC) 107 , together with connector holders 108 , provide connection and support for the plaster board surface and the stone surface. Additionally, profile grippers 109 grip on vertical profiles 150 of the support frames to attach them to the plaster surface. The stone-plaster connectors, connector holders, and grippers 109 are described in more detail herein below in FIGS. 4 and 5 . Each row of stone-plaster connectors creates, with their pairs of vertical cresses 104 , a pair of “virtual horizontal canals” 118 through which horizontal metal rods 110 may be disposed. Additionally, each vertical column of stone-plaster connectors creates, by vertical alignment of their loops 105 , a pair of “virtual vertical tunnels” 119 , for the positioning of the vertical rods 111 . In other words, the cresses and the loops of the stone-plaster connectors serve as locators for the metal grids 160 . [0096] Each hole 112 in plaster board 102 is typically 10 mm in diameter, which is slightly larger than the diameter of the plaster head 412 , which is typically 9 mm (see FIG. 4 ). Each hole 113 in a thermal insulation panel 106 coincides with its corresponding hole 112 in the plaster board. However, the diameter of holes 113 is much larger, e.g. 40 mm, than that of holes 112 . This is designed as such in order to enable concrete 170 , or other hardener, upon pouring thereof between the two surfaces 140 and 130 , to penetrate holes 113 so that they create short horizontal columns to back-support the plaster board after the concrete hardens. The horizontal distances between holes 112 are usually identical, and the vertical distances between these holes are usually identical. Pins 115 of the stone-plaster connectors may be disposed, for example between a floor and 101 , or between two vertically adjacent stones. Service conduits 116 , include, but are not limited to conduits for water, sewage, drains, electrical and communication wires and gas. These conduits are disposed between the stone and plaster surfaces. The conduits may optionally be inserted in the thermal insulation panel 106 so that they are more easily removed, added or relocated in the future after the wall has been completed. Spaces 114 may exist between any adjacent stones and may be of around 1 cm. Metal wires 120 can optionally be inserted into additional stone holes and wrapped around horizontal rods 110 to enhance the stone anchoring effect to the concrete. Sealant 121 is typically spreaded or sprayed on the back of stones 101 and in spaces 114 to prevent any penetration of humidity into the wall. [0097] Reference is now made to FIGS. 2A-2B , which show perspective front and rear views of walls 200 and ceilings 280 and 290 , in accordance with some embodiments of the present invention. [0098] Double-sided stone-stone wall 210 includes an external stone surface 211 and an internal stone surface 212 . This wall is similar to the stone-plaster wall, described in FIG. 1 , except that the internal plaster surface 102 ( FIG. 1 ) is replaced here by the stone surface 212 , and that the stone-plaster connectors 107 are replaced here by the stone-stone connectors 213 , described in further detail herein below in FIG. 4 , connector 430 . [0099] Double-sided stone-concrete wall 220 comprises an external stone surface 221 and internal removable plywood 222 . This wall is also similar to the stone-plaster wall, described in FIG. 1 , except that the internal plaster surface 102 ( FIG. 1 ) is replaced here by removable plywood 222 , and therefore the stone-plaster connectors 107 ( FIG. 1 ) are replaced here by stone-concrete connectors 223 , described in further detail herein below in FIG. 4 , connector 460 . [0100] Double-sided stone-plaster walls 230 are similar to stone-plaster wall 100 ( FIG. 1 ) and therefore connectors 233 of these walls are similar to stone-plaster connectors 107 , described in further detail herein below in FIG. 4 , connector 410 . [0101] Walls 230 contain window/door aperture 234 , in accordance with some embodiments of the present invention. It has a window frame lintel 239 . The “lips” of the window aperture include right-angle stones 235 , located along the sides of the window frame, and long flat stones 236 and 237 below and above it, respectively. At the internal side of wall 230 at least one concrete feeding hole and funnel 239 b is used in the plaster board beneath the window frame through which the concrete is poured below the window. In wide apertures of windows or doors, the upper side of lintel 239 and/or stone 237 might bend, or even break, due to the weight of the fresh concrete. In order to avoid such phenomena, pouring the concrete above the window aperture is done in two stages as follows. First, a thin concrete layer (e.g. 10-15 cm) is poured above the aperture and on metal reinforcement rods 258 a to create beam 258 , which is named here an “eye braw”. This is done after the part of each right-angle stone 235 , coming into the window aperture, is supported firmly from beneath it. And second, after the “eye brow” hardens, the rest of the concrete above the window is poured. It should be noted that, prior to pouring the concrete of the “eye brawn”, thin sheet metal spacers 239 a are placed between lintel 239 and stones 235 , 236 and 237 . This makes lintel 239 removable after the concrete hardens by, first, removing spacers 239 a , and then removing lintel 239 . However, if spacers 235 , 236 and 237 would not be used, then lintel 239 might be locked and not removable after the concrete hardens. [0102] Double-sided plaster-plaster wall 240 comprises an external plaster surface 241 and internal plaster surface 242 . Again, this wall is similar to the stone-plaster wall, described in FIG. 1 , except that the external stone surface 101 ( FIG. 1 ) is replaced here by the plaster board surface 241 , and hence stone-plaster connectors 107 are replaced here by plaster-plaster connectors 243 , described in further detail herein below in FIG. 4 , connector 420 . [0103] Double-sided plaster-concrete wall 250 includes external removable plywood 251 and an internal plaster board surface 252 . This wall is similar to the stone-plaster wall, described in FIG. 1 , except that the external stone surface 101 ( FIG. 1 ) is replaced here by the removable plywood board 251 , and that the stone-plaster connectors 107 are replace here by plaster-concrete connectors 253 , described in further detail herein below in FIG. 4 , connector 450 . [0104] Double-sided concrete-concrete wall 260 includes external removable plywood 261 and also internal removable plywood 262 . This wall is, again, similar to the stone-plaster wall, described in FIG. 1 , except that both external stone surface 101 and internal plaster surface 102 are replaced here by removable plywood boards 261 and 262 , respectively, and therefore stone-plaster connectors 107 are also replace here by concrete-concrete connectors 263 , described in further detail herein below in FIG. 4 connector 440 . [0105] The connections between walls 200 include two types of corners: internal corners 215 , 224 , 245 and 254 , and external corners 214 , 225 , 224 and 255 . Frequently, connections between walls are supported here by a profile at the internal corner, and another profile at the external corner, which are fastened to one another by a connector and/or a wire (see, for instance, 227 and 257 , respectively). In some cases, internal corners can be supported by the regular connectors, appearing at the connected walls, provided that the connectors are located close enough to the edge of the internal corner (e.g. corner 215 ). In other cases, external stone corner can be supported by external stone corner connector 228 , described in further detail herein below in FIG. 4 , connector 4120 . [0106] Wall 270 is an existing wall, which is supposed to be coated by coating stones 272 . Stone anchoring net 271 is anchored to wall 270 by bolts 274 and discs 275 . Wedge 276 is used to help level the net in the desired plain, typically but not necessarily, vertical. Stones 272 are anchored to net 271 using stone-net connectors 273 , similar to that described in further detail herein below in FIG. 4 , connector 4100 . [0107] Reference is now made to ceilings 280 and 290 in FIGS. 2A-2B , in accordance with some embodiments of the present invention. Ceilings 280 and 290 sit on a pergola assembly comprising of jacks 231 , profile beams 232 a and 232 b and profiles 284 , including wedges 232 c and cable spacers 232 e . Jacks 231 are standard jacks used in the field of construction, where their heights are adjustable. Profile beams 232 a and 232 b are typically hollowed rectangular profiles. They are similar in dimensions while one can be inserted inside the other. For instance, profile beams 232 a and 232 b can be of 60×30 and 50×25 mm hollowed rectangular profiles, respectively, with wall thickness of around 1.5 mm. Thus, profile beam 232 b can be entered into profile beam 232 a while wedge 232 c is inserted in between them to compensate for the few millimeter difference in their width to assure that their top aspects reach similar height. Note that beneath the overlapping parts of each pair of beams (and wedge 232 c ) jack 231 is placed for reaching maximal strength at the support area. Wedge 232 c has hole 232 d for anchoring cables to laterally support beams 232 a and 232 b , typically anchored to the floor or to a neighboring beam. Safety pin can also be used to connect between each pair of neighboring profile beams. [0108] Typically, profiles 284 are placed orthogonally on top of profile beams 232 a and 232 b . Profiles 284 are typically equally spaced, e.g. 15 cm apart from one another, and each one of them is oriented at a “v-shape”, in order to have a large interface and support for the plaster board placed on top of them. Thin cable spacers 232 e , which have solid stoppers 232 f at their ends, are used for two purposes as follows: a. fast and easy laying out and folding them on top of the profile beams, b. Fastening them at their “v-shape” position while maintaining them equally spaced. [0111] Note that the overlapping part of each neighboring profiles 284 must be supported by a profile beam in order to avoid possible collapse. [0112] The selection of such profiles is done because of a number of reasons as described bellow: a. Both kinds of profiles are easily overlappable and adjustable to the necessary length and width of the constructed ceiling. b. They are easily laid out and folded. c. At their folded and packed positions they are extremely compact and easily moved and/or shipped either inside the construction site or between construction sites. d. They occupy minimal storage space, in comparison with most of the heavy duty forms and woods traditionally used. [0117] Plaster coated ceiling 280 is viewed here as a sort of horizontal wall, where its bottom face is viewed here as the internal aspect of this “wall”. In this view, its internal plaster board surface 281 serves as, sort of, lining, and therefore it is similar to internal plaster board surface 102 of stone-plaster wall, described in FIG. 1 , except that stone-plaster connectors 107 are replaced here by plaster-ceiling connectors 283 , described in further detail herein below in FIG. 4 , connector 480 . Just like stone-plaster wall 100 ( FIG. 1 ), supported by profiles 103 , optionally thermally insolated by thermal insulation board 106 , and its connectors are held by connector holders, also here, ceiling 280 is supported by profiles 284 , optionally thermally insolated by thermal insulation board 282 , and plaster-ceiling connectors 283 are held by either connector holders or profile gripper at the ceiling's bottom (not seen), described herein below in FIG. 2A . And also the ceiling support arrangement of jacks 231 , profile beams 232 a and 232 b and profiles 284 is depicted in detail in FIG. 2A as well. Note that edges 281 a of the two adjacent plaster boards are supported by the same profile, and they are also sealed by tape 281 b in order to prevent fresh concrete leakage. Bricks 285 are often placed on ceilings, where spaces 286 in between them form the beams and the ribs of the ceiling. Just like in stone-plaster wall 100 ( FIG. 1 ), service conduits 287 include, but are not limited to, conduits for electric and/or communication wires. These conduits are disposed above plaster boards 281 and possibly inside groove 282 a of thermal insulation board 282 , so that they are more easily removed, added or relocated in the future after the ceiling has been completed. [0118] Stone coated ceiling 290 is also viewed here as a, sort of, horizontal wall, where its bottom is the internal aspect (or lining) of this “wall”. In this light, again, internal plaster surface 102 in FIG. 1 is replaced here by stone surface 291 , except that stone-plaster connectors 107 are replaced here by stone-ceiling connectors 293 , described in further detail herein below in FIG. 4 , connector 490 . Note that the stone-net connector 292 can also be used, particularly when an anchoring net is placed on top of stone surface 291 . [0119] Walls 200 contain wall-ceiling connection preparation 264 at the tops of them, in accordance with some embodiments of the present invention. Beyond the tops of walls 200 , at their external surfaces, an additional row of stones 269 , or plaster boards 243 (or plywood), called external ceiling rail, is assembled. This external rail is connected to (internal) profile rail 265 by any appropriate connectors (according to the kind of the connected wall) and profile grippers 266 , which grip on profile rail 265 . Each vertical profile of the support frame is protected from the ceiling's concrete by solid sleeve 267 . After the ceiling's concrete hardens, each sleeve 267 forms a vertical hole in the ceiling. This hole serves as a passage for lifting support frames (and possibly additional items) for the construction of the next floor, without having to put apart the support frame. Note that there is opening 268 beneath each profile rail 265 since there is no plaster board, plywood or stones against external ceiling rail 269 . The role of this opening is to enable the placement of the ceiling's concrete and metal reinforcement rods, coming from the internal side of the wall, to be on top of the connected walls. [0120] Reference is now made to FIGS. 3A-3B , which show perspective front and rear views of a multi-sided, columns and beams, in accordance with some embodiments of the present invention; [0121] Reference is now made to plaster coated column 340 and stone coated column 330 in FIGS. 3A-3B , in accordance with some embodiments of the present invention. Columns are viewed here as narrow walls. Therefore, unlike walls 200 described in FIGS. 2A-2B , which are supported at one side only, columns need to be supported at more than one side. Thus, support frames may appear at more than one side and/or their corners as well. [0122] FIGS. 3A-3B show perspective front and rear views of plaster coated column 340 . It is supported vertically by support frame 347 , and when necessary, additional support frames 354 might be added, together with profile grippers 355 , described in further detail herein below in FIG. 5 , element 520 . Here, plaster-plaster connectors (PPC) 342 , connector holders 343 and profile grippers 355 are used to connect plaster boards 341 in the same manner as they are used to connect the plaster surfaces of plaster-plaster wall 240 in FIGS. 2A-2B . Reference numeral 345 represents the metal reinforcement rods, which are assembled vertically, and reference numeral 335 represents the metal reinforcement rims, which are assembled horizontally. Note that plaster-plaster connectors 342 might also connect pairs of vertical profiles, which can also be located at corners, diagonal to one another. [0123] FIGS. 3A-3B also show perspective front and rear views of stone coated column 330 . This column is also supported vertically by support frame 337 and, when necessary, additional support frames 365 might be added, together with profile grippers 317 . Here, every two adjacent stones 331 are mutually connected by stone corner connector 332 , similar to connector 4120 described in FIG. 4 . Here, stone-stone connectors (SSC) 333 can be added and used in the same manner as they are used to connect the stone surfaces of stone-stone wall 210 in FIGS. 2A-2B . Also here, reference numeral 334 represents the metal reinforcement rods, assembled vertically, and reference numeral 335 represents the metal reinforcement rims, assembled horizontally. Finally, note that the support frames can be fastened to the stone connectors (either 332 or 333 ) by screw 332 a , and/or wire 332 b and/or profile grippers 317 . [0124] Reference is now made to plaster coated beam 350 and stone coated beam 360 in FIGS. 3A-3B , in accordance with some embodiments of the present invention. Beams are viewed and treated here as hybrid structures of both ceilings and walls. Therefore, on the one hand, they are supported by jacks and profiles from the bottom, as ceilings 280 and 290 in FIGS. 2A-2B . And, on the other hand, they are also supported by support frames 347 and 365 , similar to walls 200 in FIGS. 2A-2B . More specifically, in plaster coated beam 350 , the lateral plaster surfaces 351 are connected to one another by plaster-plaster connectors 352 , and connector holders 353 , similar to those of plaster-plaster wall 240 in FIGS. 2A-2B , And, in its bottom plaster board, plaster-ceiling connectors (not seen) are used, similar to those used in plaster coated ceiling 280 in FIGS. 2A-2B . Similarly, in stone coated beam 360 , lateral stone surfaces 361 are connected to one another by stone-stone connectors 361 , similar to stone-stone wall 210 in FIGS. 2A-2B . And, in its bottom stones, stone-ceiling connectors (not seen) are used, similar to those used in stone coated ceiling 290 in FIGS. 2A-2B . Finally, when necessary, the top aspect of beams 350 and 360 are coated right after the concrete is poured. Note that beam 350 can be converted to partially or fully uncoated beam if its plaster boards are removed. [0125] Turning now to FIG. 4 , there can be seen various construction connectors for constructing cast structures such as walls, ceilings, columns and beams, in accordance with some embodiments of the present invention. [0126] FIG. 4 shows a perspective view of a stone-plaster connector (SPC) 410 , similar or identical to stone-plaster connector 107 ( FIG. 1 ), typically made of a polymeric material. Such material, typically made of a special cross linked high density polyethylene, is used to withstand high mechanical loads for many years at extreme environmental conditions such as plus/minus 110 degrees centigrade. Connector 410 is constructed and configured to which fastens stone 101 and plaster board 102 to the concrete 170 inside wall 100 ( FIG. 1 ). The connector includes three parts: a stone head 411 , a plaster head 412 , and a body 413 . The stone head 411 includes a relatively thick part 414 , of around 1 cm in thickness, for bearing the weight of stone(s) 101 and for serving as a spacer between stones, and a sharp pin 415 which is inserted into the stone holes for fastening the stones to the concrete of the wall. Each sharp end of the pin is designed primarily to serve as a guide to ease the insertion of the pin into the stone hole—especially into an aperture 180 (not shown) located at a lower surface of stone 101 ( FIG. 1 ), which are invisible during the assembling process. The plaster head 412 includes a screw 416 , having a conic head 402 for fastening the plaster board to the wall, and an end plate 417 for supporting the plaster board from a rear side. The diameter of both the plaster head 412 and that of the screw head is slightly smaller, e.g. 9 mm, than the diameter of the hole in the plaster board, e.g. 10 mm. When the screw is driven into the connector 410 , its conic head expands the connector's lips 403 to around 13 mm, which become larger than the diameter of the plaster board aperture hole (10 mm), and this tightens the plaster board to the concrete cast in the wall. The connector's body 413 includes two pairs of vertical cresses 418 , or more or less, if required, which are configured in parallel to pin 415 , and a couple of horizontal loops 419 (or more or less, as required), which are orthogonal to pin 415 . The pairs of cresses are constructed and configured to aid the placing in position of horizontal metal reinforcement rods 110 there between ( FIG. 1 ) in such a way such that a row of parallel connectors create a pair of “virtual horizontal canals” 118 between cresses 418 , as is seen in FIG. 1 , for the placement of the horizontal metal rods. [0127] Similarly, two loops 419 are designed for positioning the vertical rods 111 so as to form a vertical column of loops thereby creating a couple of “virtual vertical tunnels” 119 , disposed to receive the vertical metal rods. In other words, the cresses and loops avoid the need to tie the rods for forming metal grids 160 [0128] FIG. 4 also shows a perspective view of plaster-plaster connector (PPC) 420 , similar or identical to plaster-plaster connector 243 ( FIGS. 2A-2B ). It connects two plaster boards, such as plaster boards 241 and 242 , to the concrete of plaster-plaster wall 240 , seen in FIGS. 2A-2B . Plaster-plaster connector 420 is similar to stone-plaster connector 410 , except that the stone head is replaced here by the plaster head. [0129] FIG. 4 shows also a perspective view of stone-stone connector (SSC) 430 , similar or identical to stone-stone connector 213 (seen in FIG. 2A ). It connects two stone surfaces, such as stone surfaces 211 and 212 , from both sides of the concrete of stone-stone wall 210 (seen in FIGS. 2A-2B ). Stone-stone connector 430 is similar to stone-plaster connector 410 (in FIG. 4 ), except that its plaster head 412 is replaced here by a stone head, with screw 436 added to it for fastening the connector to a support frame using profile gripper 520 (seen in FIG. 5 ). [0130] FIG. 4 shows a perspective view of concrete-concrete connector 440 , similar or identical to concrete-concrete connector 263 (seen in FIGS. 2A-2B ). It connects two thin removable boards, such as removable boards 261 and 262 (typically made of 4 mm thickness plywood, a plastic board or thin sheet metal) to the concrete of wall 260 (seen in FIGS. 2A-2B ) in a similar way as stone-plaster connector 107 connects stones 101 to plaster board 102 , where connector holder 108 is used (see FIG. 1 ). However here, the thin removable boards are destined to be removed soon after the concrete hardens, and hence the concrete remains exposed. The diameter of concrete head 443 (typically 13 mm) is greater than the diameter of the holes (typically 10 mm) of the removable board. It is designed as such in order to back support the removable board. [0131] FIG. 4 also shows a perspective view of plaster-concrete connector 450 , similar or identical to plaster-concrete connector 253 (seen in FIGS. 2A-2B ). It connects a plaster board to a thin removable board, for instance plaster board 252 to removable board 251 in plaster-concrete wall 250 (seen in FIGS. 2A-2B ). Plaster-concrete connector 450 is similar to stone-plaster connector 410 , except that the stone head of connector 410 is replaced here by the concrete head. [0132] FIG. 4 shows also a perspective view of stone-concrete connector 460 , similar or identical to stone-concrete connector 223 (seen in FIGS. 2A-2B ). It connects a removable board to a stone surface such as removable board 222 to stone surface 221 of stone-concrete wall 220 (seen in FIGS. 2A-2B ). Also here, Stone concrete-connector 460 is similar to stone-plaster connector 410 , except that the plaster head is replaced here by the concrete head. [0133] FIG. 4 shows a perspective view of an adaptable connector 470 . The components of connector 470 are concatenated by screws 471 , 473 and 475 . Adaptable connector 470 is often used for various circumstances where the distance varies between the stone plane and the plaster board plane (or the concrete plane). While the two heads here of the connector resemble the stone head and the plaster head of stone-plaster connector 410 , depicted in FIG. 4 , it is meant to depict here all the permutations of all the 3 various heads (e.g. stone, plaster and concrete), described in FIG. 4 . [0134] FIG. 4 shows a perspective view of plaster-ceiling connector 480 , similar or identical to plaster-ceiling connector 283 (seen in FIGS. 2A-2B ). It connects plaster board 282 ( FIGS. 2A-2B ) to ceiling 280 in the same manner as stone-plaster connector 107 connects plaster board 102 to the concrete of wall 100 ( FIG. 1 ). [0135] FIG. 4 shows a perspective view of stone-ceiling connector 490 , similar or identical to stone-ceiling connector 293 (seen in FIGS. 2A-2B ). It connects stones 291 ( FIGS. 2A-2B ) to ceiling 290 in the same manner as stone-plaster connector 107 connects stones 101 to the concrete of wall 100 ( FIG. 1 ). [0136] FIG. 4 shows a perspective view of stone-net connector 4100 , similar or identical to stone-net connector 273 (seen in FIGS. 2A-2B ). It is used for stone coating an existing wall (or ceiling) such as wall 270 described in FIG. 2B . Stone-net connector 273 , typically made of a polymeric material such as plastic, is constructed and configured to which fastens stones 272 to stone anchoring net 271 depicted in FIG. 2B . Stone-net connector 4100 includes 3 parts: stone head 4101 , net head 4103 , and body 4102 . Stone head 491 is similar or identical to stone head 411 of stone-plaster connector (SPC) 410 , depicted in FIG. 4 . Net head 4103 is a ring with a “V” shape opening 4105 to enable clipping the connector to the net's wire, which has similar or identical diameter to that of the net's head hole 4106 of the connector. [0137] FIG. 4 also shows a perspective view of wedge 4110 , similar or identical to wedge 276 depicted in FIG. 2B . Wedge 4110 , typically made of a polymeric material (such as plastic), is used to guarantee that the stone anchoring net 271 is constantly vertical or uniformly inclined in the desired orientation. The circular grooves 4111 have similar or identical radius as that of the wires of stone anchoring net 271 , depicted in FIG. 2B . Wedge 4110 is essentially an adaptable spacer between the anchoring net and the existing wall. [0138] FIG. 4 shows a perspective view of a stone corner connector (SCC) 4120 , similar or identical to stone-corner connector 228 , described in FIGS. 2A-2B . Stone-corner connector, typically made of a polymeric material such as plastic, connects two adjacent stone surfaces 211 and 221 of wall 220 , usually at a corner, as described in FIGS. 2A-2B . It is also often used at corners of stone coated columns, such as stone corner connector 332 , of stone coated column 330 , described in FIGS. 3A-3B . The connector includes a thick body 4123 of around 1 cm thickness, which also serves as a spacer between stones. It typically comprises of two (typically metal) sharp pins 4125 , which are inserted into the stone's apertures (not shown) for fastening the stones to each other. The sharpness of each pin is usually designed to serve as a guide to ease the insertion of the vertical pin into the aperture (not shown), especially those located at a lower surface of the assembled stone (which are invisible during the assembling process). Screw 4126 is designed to fasten the stones surface to a support frame using a profile gripper. The other holes, such as 4124 and 4127 are designed to provide additional possibilities for fastening the connector to supporting profiles. Cress 4128 is designed to guide and hold a horizontal metal rim, such as rim 335 in column 330 , depicted in FIGS. 3A-3B . Loop 4129 is designed to guide and hold a vertical metal rod, such as rod s 334 , seen in FIGS. 3A-3B . In other words, the cress and loop avoid the need of tying the metal reinforcement rods and rims to each other, as in prior art systems. [0139] Reference is now made to FIG. 5 , which shows various construction elements 510 , 510 a , 520 , 530 and 540 for constructing cast structures such as: walls, ceilings, columns and beams, in accordance with some embodiments of the present invention. [0140] FIG. 5 shows a front view of connector holder 510 . It is typically a rectangular plate, often made of metal. Typical dimensions may be, for example, 20 by 15 cm. In one embodiment, it is made of a sheet metal, and comprises reinforcement support bends or elements 511 . This design enables the connector holder to be as light as possible, yet provides significant mechanical strength. [0141] The connector holder comprises of hole 512 of roughly keyhole shape. The hole includes a narrow part of around 5 mm, to hold the neck of the connector's screw 416 , described in further detail in FIG. 4 , and a wide part, of around 12 mm for quick and easy insertion and receiving of the screw head. Usually, the hole is placed essentially in the center of the plate. However, in some circumstances it is located close to the edge of the plate, e.g. in cases where it needs to be positioned at the edge of the wall. Connector holder 510 a serves as an example for edge connector holder. An example of its usage can be seen in the bottom row of connector holders of wall 100 (seen in FIG. 1B ). [0142] FIG. 5 also shows a perspective view of a profile gripper 520 . This plate, typically made of a sheet metal, includes two mutually perpendicular parts, resembling a book end. Part 524 is flat and has a hole 522 of a keyhole shape, similar to or identical to hole 512 , except that hole 522 has two, as apposed to one, narrow parts. The narrow parts of the hole are designed to hold the screw of a connector at its neck, and the wide part of the hole serves as a passage for a quick and easy insertion of the head of the screw. Part 521 includes bending of about 180 degrees and it is designed to grip on the profile as depicted in assembly 540 . The two narrow parts allow gripping a profile at its either side. [0143] FIG. 5 shows also a perspective view of profile 530 , typically made of sheet metal, which is long and bent longitudinally at a right angle with equally spaced holes 531 along its length. It is often used for forming support frames to vertically support cast structures as seen in FIGS. 1-3 . It is also used for creating a profile ceiling rail 265 as described in FIGS. 2A-2B , as well as support for ceiling (e.g., profiles 284 in FIG. 2A ). [0144] Finally, FIG. 5 shows assembly 540 , comprising of connector 541 , connector holder 510 and profile gripper 520 , which are assembled together with profile 530 , to make sturdy assembly 540 . Holes 512 of the connector holder and holes 522 of the profile gripper coincide, and through them the screws of the various connectors, shown in FIG. 4 are inserted. The gripping format of the profile gripper is designed as such in order to accommodate various widths of stone. While in stone-plaster wall 100 ( FIG. 1 ), for instance, both the connector holder and the profile gripper are used together, in stone-stone wall 210 ( FIGS. 2A-2B ), for instance, only profile gripper 520 is used (without connector holder 510 ). [0145] FIG. 6 is a simplified flow chart 1000 of a method for constructing a double-sided stone-plaster coated wall 100 described in FIG. 1 ; in accordance with some embodiments of the present invention. [0146] In a first assembling step 1002 , a plaster board is positioned. Prior to this step, the following optional steps may be performed onsite: Determining Stone's Positions: [0000] a. Numbering stones 101 upon their arrival to the construction site, b. Determining their locations on the wall. In step 1002 , the internal plaster surface is positioned by: a. drilling plaster board 102 , b. attaching to it a support frame 103 , using a stone-plaster connector (SPC) 107 , connector holder 108 and profile gripper 109 , described in further detail in FIGS. 4-5 , respectively, and anchoring support frame 103 to the floor, c. optionally attaching thermal insulation panel 106 to plaster board 102 , while puncturing it to create holes 113 , using plaster board 102 as a model, and then enlarging holes 113 by a drilling cup, d. attaching additional support frames to plaster board 102 using stone-plaster connectors, connector holders and profile grippers, and anchoring them to the floor as well, e. assembling the lowest row of stone-plaster connectors 107 to plaster board 102 , using connector holders 108 , while the sharp ends of the pins of the stone-plaster connectors 115 are vertical, In a second assembling step 1004 , a row of stones is assembled opposite to the plaster surface. This step may entail, for example, the following sub-steps: a. Drilling each stone 101 of the first row, b. Optionally applying sealant to the surfaces forming the gaps between neighboring stones, c. Positioning each stone against plaster board 102 and insulation panel 106 , while inserting pins 115 of the lowest row of stone-plaster connectors into the holes located at the bottom of each, and d. Optionally applying sealant on the back of the stones row. [0158] In a third assembling step 1006 , horizontal reinforcing rods 110 are assembled between the two boards assembled in the previous two steps, respectively. Step 1006 comprises the following typical sub-steps: a. placing a horizontal metal rod 110 at each of the two “horizontal canals” 118 , created by the row of stone-plaster connectors 107 , b. assembling an additional row of stone-plaster connectors 107 to plaster board 102 , using connector holders 108 , and inserting their pins into the upper holes of the row of stones, c. Placing additional horizontal metal rod 110 at each of the two “horizontal canals” 118 . [0162] In a checking step 1007 , the height of the wall is examined as to whether or not it reaches the desired height. If the height hasn't reached the desired one, then we proceed to the additional checking step 1009 . In checking step 1009 , the height of the row to be assembled is compared to the plaster board height. If it is less than the plaster board height, then steps 1004 , 1006 and 1007 are repeated. The following sub-steps may then be performed: a. drilling an additional row of stones and placing it on top of the previously assembled one, b. assembling an additional row of stone-plaster connectors 107 to plaster board 102 , using connector holders 108 , and inserting their pins into the upper holes of the row of stones, c. placing an additional horizontal metal rod 110 at each of the two “horizontal canals” 118 , d. optionally adding any required service conduits, e. Cementing spaces 114 between any neighboring stones, including adding adhesive sealant in spaces 114 . [0168] These sub-steps are repeated until the height of the row to be assembled exceeds the height of plaster board 107 . If it does, then step 1002 is added to the assembling process. [0169] This iterative process takes place repeatedly while adding rows of plaster boards and insulation panels at the internal side of the wall, and rows of stones at the external side of it, and placing horizontal metal rods and service conduits in between them, until the desired height of the wall is finally reached. Then, vertical reinforcement rods 111 are threaded through “vertical tunnels” 119 , created by the vertically aligned loops of stone-plaster connectors 107 , to obtain metal reinforcement grids 160 . At the end of this assembling process, a hollowed wall is obtained, which is supported vertically by a row of support frames and is composed of layers: plaster board layer, insulation panel layer, internal metal grid layer, external metal grid layer, and a stones board layer. [0170] In a filling step 1010 , the final form of the wall is produced by: a. pouring concrete 170 into the wall, while using vibration, and waiting for it to harden, b. dismantling the profile grippers, the support frames, and the connector holders, and c. Driving the screws of the stone-plaster connectors into the plaster board. [0174] The stone-plaster connectors remain in the wall forever to fasten both the plaster boards and the stone to the cast wall. [0175] At this stage, a stone coated wall on the outside and plaster coated on the inside, is obtained, which is optionally thermally insulated. The internal aspect of the wall is ready for painting while the external aspect is fully completed. [0176] Although FIG. 1 shows a flat wall, this method includes rounded walls as well. In the latter cases, both the plaster board and the connector holders need to be rounded in the necessary curvature and sufficiently short and appropriate stones need to be used. Note that in such cases the distances between the stone holes and those of the plaster board are different. [0177] It should be understood that many permutations and variations on this method are possible and are deemed to be within the scope of this invention. Preferred Construction Methods and Procedures for Cast Structures Construction of Stone-Plaster Wall [0178] The construction of stone-plaster wall, in accordance with the present invention, is described in further detail in FIG. 1 and FIG. 6 . FIG. 1 describes the components of the wall, including the connectors and elements used to successfully assemble the wall. FIG. 6 , however, describes a flowchart, which describes step-by-step the sequential procedure of carrying out the mission of assembling and building a stone-plaster wall. Construction of Plaster-Plaster Wall [0179] The construction method of a plaster-plaster wall, according to the invention, as described in wall 240 in FIG. 2 , is performed similar to that of a stone-plaster wall, and it includes the following typical steps: 1. establishing internal plaster surface 242 as described in the stone-plaster wall construction, using plaster-plaster connectors (PPC) 243 , described in further detail in FIG. 4 connector 420 , instead of SPC 107 (in FIG. 1 ), 2. establishing the external plaster surface 241 in a similar manner, and adding horizontal metal reinforcement rods and any required service conduits, 3. assembling the rest of the wall by adding additional plaster boards, Plaster-plaster connectors, metal rods and service conduits, 4. The final construction of the wall is performed as in the stone-plaster wall. 5. Although FIG. 2 shows a flat wall, this method includes rounded walls as well. In the latter cases, the plaster boards, the metal rods and the connector holders can be rounded in the necessary curvatures. Note that in such walls the horizontal distances between neighboring holes in one plaster surface are different from those of the other surface. Construction of Stone-Stone Wall [0185] The construction method of a stone-stone wall, according to the invention, as described in FIG. 2 in wall 410 , is performed similar to that of the stone-plaster wall, and it includes the following typical steps: 1. determining stones' positions, using the computer program, 2. positioning the first drilled internal row of stones 212 on top of a row of stone-stone connectors (SSC) 413 , described in FIG. 4 connector 430 , while the sharp ends of the connectors' pins are inserted into the holes, located at the bottom of the stones, and the external pins are positioned at the external front of this wall, 3. similarly, connecting the external stone row 411 to stone-stone connectors 413 , and then placing a pair of horizontal metal rods on top of stone-stone connectors 413 , and connecting to them vertical support frames, using profile grippers, 4. assembling the rest of the wall by adding rows, stone-stone connectors, horizontal metal rods, service conduits, and, at the end, threading vertical metal rods, 5. The final construction of the wall is performed as in the stone-plaster wall. 6. Although FIG. 2 shows a flat wall, this method includes rounded walls, provided that sufficiently short and appropriate stones are used, and the appropriate distances between stone holes are determined. Construction of Partially or Fully Uncoated Wall [0192] The partially and fully uncoated walls include 3 types of walls as follows (see FIGS. 2A-2B ): a. stone-concrete (concrete means uncoated) wall (e.g., wall 220 ), b. plaster-concrete wall (e.g., wall 250 ), and c. concrete-concrete wall (e.g., wall 260 ) [0196] The construction method of a stone-concrete wall, according to the invention, is performed similar to that of a stone-plaster wall, except that here stone-concrete connector 223 , depicted in FIG. 4 connector 460 , is used. [0197] In this case, the plaster board is typically a thin plywood, plastic board or sheet metal, which is removed together with the connectors' screws that fasten it, after the concrete hardens. [0198] The construction method of a plaster-concrete wall, according to the invention, is performed similar to that of a stone-plaster wall, except that here plaster-concrete connector 453 , described in further detail in FIG. 4 connector 450 , is used. In this case, the stone plane is replaced here by a thin plywood board, a plastic board or a sheet metal, which is removed, together with the connectors' screws that fasten it, after the concrete hardens. [0199] The construction method of a concrete-concrete wall, according to the invention, is performed similar to that of a plaster-plaster wall, except that here, concrete-concrete connector 463 , described in further detail in FIG. 4 connector 440 , is used. In this case, the plaster boards on both sides of the wall are typically thin plywood, plastic board or sheet metal, which are both removed, together with the screws of the connectors, after the concrete hardens. [0000] Construction of Wall with Window/Door 1. assembling the wall as described in the stone-plaster wall 230 in FIGS. 2A-2B construction, until the height of the window base is reached, 2. establishing the internal plaster boards at the window level, 3. drilling the stones and assembling them using stone-plaster connectors (SPC) 233 , connector holders and, when necessary, profile grippers, 4. drilling and assembling the right-angle stones 235 at the sides of the window frame lintel 239 , 5. when the top of the window frame lintel is reached, a drilled stone 237 is assembled, and two or more metal rods 258 a are placed on top of it, together with a thin layer of concrete, e.g. 10 cm, to strengthen stone 237 together with it's neighboring stone 235 for withstanding the weight of the poured concrete above it in the future, 6. Building the rest of the wall as described in the stone-plaster wall construction. 7. When a door frame lintel is used, then the door frame lintel is positioned on the floor, and the assembling procedure is the same. 8. When plaster-plaster, or concrete-concrete, or plaster-concrete wall is built with window/door aperture, then long marble stones are added to the sides of the window/door aperture in order to fully frame the lintel by stones. Construction of Ceiling [0208] The construction method of plaster or stone coated ceiling, in accordance with some embodiments of the present invention, is described herein below. [0209] The construction process of plaster coated ceiling 280 , described in FIGS. 2A-2B , includes the following typical steps: 1. Positioning jacks 231 , profiles beams 232 and right-angle profiles 284 , 2. Drilling plaster boards 281 , positioning them above profiles 284 while their connection 281 a is on top of single profile 284 , and taping connection 281 a by tape 281 b, 3. if necessary, placing thermal insulation boards 282 above plaster boards 281 and creating large holes 287 c , using drilled plaster boards 281 as a model, 4. When necessary, adding bricks 285 , metal reinforcement rods and service conduits 287 , 5. Typically connecting ceiling-plaster connectors 283 , together with connector holders at the bottom (not seen), 6. Pouring concrete with vibration, 7. After the concrete hardens, removing the connector holders and tightening the screws of ceiling-plaster connectors 283 , and 8. Removing jacks 231 , profile beams 232 and right-angle profiles 284 . [0218] The construction process of stone coated ceiling 290 is similar to that of plaster coated ceiling 280 , except that here, coating stones 291 are used. The stones are drilled and assembled in a similar way as stones 101 in FIG. 1 are drilled and assembled. Also here, ceiling-stone connectors 293 are used, in stead of ceiling-plaster connectors 283 , together with connector holders (or maybe profile grippers). Note that here, when removing the connector holders, the screws of connectors 293 are removed as well. Wall-Ceiling Connection [0219] Wall-ceiling connection requires that the metal rods and the poured concrete of the ceiling would be on top of the wall as a one complete continuum. It is also required that this concrete would not be spilled externally beyond the wall. Therefore, an additional row of stones needs to be assembled beyond the height of the wall, which serves as a “peripheral stone rail” for preventing the concrete of the ceiling, when poured, from being spilled. This is performed in the following typical steps (see FIGS. 2A-2B ): 1. threading a short solid sleeve 267 through each vertical profile of the support frames, to protect it from the concrete, 2. assembling horizontal “ceiling profile rail” 265 to each vertical profile, 3. connecting the “ceiling stone rail” to the “peripheral profile rail” 243 , using both stone-plaster connectors (SPC) and profile grippers 266 , 4. If a plaster-plaster wall is built, then the same method is used, except that, instead of a “ceiling stone rail”, the external plaster board is used together with plaster-plaster connectors (PPC). Stone Coating of an Existing Wall [0224] In order to coat wall 270 by stones 272 (see FIG. 2B ), stone anchoring net 271 is first anchored to wall 270 , using bolts 274 and discs 275 . Wedges 276 are used to help level net 271 . Then, stones 272 are drilled and assembled on the wall in a similar way as assembling the stones in wall 100 , described in FIG. 1 , except that here, stone-net connectors 273 are used. Note that typically here the concrete is poured between stones 272 and wall 270 after assembling fewer rows of stones (e.g. one or two) and not necessarily after reaching the top of the wall. Also note that once net 271 is positioned at the required orientation (typically vertical), stone-net connectors 273 make sure that all stones 272 are mutually co-planar as desired. Construction of Plaster Coated Column [0225] The construction method of a plaster coated column, according to the invention, as described in FIGS. 3A-3B , includes the following typical steps: 1. Cutting and drilling all plaster boards 341 , 2. positioning the plaster boards, except one, and attaching them to support frames 347 using plaster-plaster connectors (PPC) 342 , connector holders 343 , and, when necessary, profile grippers, and anchoring the support frames to the floor, 3. fastening reinforcement metal rods 345 and metal rims 345 a to the plaster-plaster connectors through the sides of the column where the plaster board hasn't been assembled, and then assembling this missing plaster board, using connector holders 343 , 4. Pouring concrete and, after it hardens, dismantling the supporting elements as described in the construction of a stone-plaster wall. 5. For wider columns, more than one column of plaster-plaster connectors needs to be assembled. 6. Although FIGS. 3A-3B shows a rectangular column, this method includes columns of various polygons. It also includes circular and elliptic forms. In the latter cases, the plaster boards, the metal rims and the connector holders should be rounded in the necessary curvature. Construction of Stone Coated Column [0232] The construction method of a stone coated column, according to the invention, as described in FIGS. 3A-3B , includes the following typical steps: 1. cutting stone 331 to the proper sizes and drilling them, 2. assembling the bottom stone frame using stone corner connectors (SCC) 332 , described in further detail in FIG. 4 connector 4120 , and fastening it to the support frames, using profile grippers, when necessary, then placing each metal reinforcement rim 335 on top of the SCCs, such that each cress of the SCCs (see FIG. 4 connector 4120 ) is located inside the rim, 3. repeating step 2 iteratively while filling the spaces between stones with cement and adhesive sealant, until the height of the column is reached, 4. threading each vertical reinforcement rod 334 through the loops of SCCs 332 , 5. pouring concrete, and after in hardens, dismantling the support frames, 6. Although FIGS. 3A-3B shows a rectangular column, this method includes columns of various polygons and circular and elliptic forms, provided that the proper stone shapes are used. Construction of Partially or Fully Uncoated Column [0239] The construction of partially or fully uncoated column requires the replacement of the plaster boards (or stones) of the desired uncoated sides by plywood boards and, correspondingly, using the appropriate connectors that have concrete heads at the desirable uncoated sides of the column. Finally, pouring the concrete in the same manner as previously described, and after it hardens, removing the plywood boards to obtain uncoated sides of the column as desired. Construction of Beams [0240] The construction process of a plaster coated beam, in accordance with the embodiment of the present invention, is performed in the following steps (see FIGS. 3A-3B ): 1. Erecting jacks, placing profile beams on top of them, and positioning right-angle profiles in the appropriate configuration, using the same principles described in ceiling 280 , described in FIGS. 2A-2B , 2. drilling the bottom plaster board, placing it on top of the right-angle profiles, and adding plaster-ceiling connectors, together with their connector holders, 3. erecting profile frames 355 , similar to that when building wall 100 in FIG. 1 , 4. assembling drilled plaster boards 351 , using plaster-plaster connectors 352 in a similar manner as assembling plaster-plaster wall, and adding the metal reinforcement rods, 5. pouring the concrete, and adding additional boards on top of the beam, if necessary, 6. After the concrete hardens, removing the support frames, the connector holders, the jacks, and the profiles, and screwing the screws of the various connectors into the plaster boards. [0247] The construction process of a stone coated beam, in accordance with the embodiment of the present invention, is performed in a similar way as the plaster coated beam is done. However, coating stones as apposed to, plaster boards are used. And, of course, the bottom stones are drilled and assembled in a similar manner as stone coated ceiling 290 (described in FIGS. 2A-2B ), together with stone-ceiling connectors. The side stones are drilled and assembled in a similar manner as stone-stone wall 210 is built (see FIGS. 2A-2B ). Abbreviations [0000] SPC—stone-plaster connector PPC—plaster-plaster connector SSC—stone-stone connector SCC—stone corner connector

The invention relates to a method for producing cast structures, and a set of connectors for connecting a pair of opposed, spaced apart boards which are useful in said method. A kit of elements useful as support frames in the production of the cast structures is also provided.

BACKGROUND OF THE INVENTION The present invention relates to an electrophotographic copying apparatus, and more particularly to a mechanism for withdrawing a copy paper transporting unit from the body proper of a copying apparatus. Generally, a copying apparatus developed in recent years is so constructed that at least a part of the apparatus which is constituted by various elements, such as copy paper transporting means, developing means and cleaning means, is made into a unit for withdrawal from the body proper thereof so as to make inspection of the apparatus, replacement of the photosensitive member or removal of jammed copy paper simple. One example of such a copying apparatus is shown in U.S. Pat. No. 4,017,169 in which a copy paper transporting unit combined with a corona transfer station is mounted for lateral withdrawal from the interior of the copying apparatus in a direction perpendicular to the feeding direction of the copy paper. However, the problem with this unit is that if copy paper is jammed at a position in which one end of the paper is nipped by a pair of feeding rollers and the other end of the paper extends into the unit, the paper may be torn since the unit is withdrawn in a direction perpendicular to the feeding direction of the copy paper. Further problems with this unit are that the mechanisms for releasing the unit from, and for locking the unit with, the copying apparatus are relatively complicated, and their operations are quite troublesome. Japanese Unexamined Patent Application SHO No. 53-12335 published on Feb. 3, 1978 discloses an image transfer type copying apparatus with a copy paper transporting unit constructed so as to be able to be withdrawn in the feeding direction of the copy paper. Such unit extends from a feeding station, including a paper feeding roller, to an image transfer station or all the way to the paper discharging end. However, in this apparatus, if copy paper is jammed in the vicinity of the feeding roller, the paper cassette, containing a stack of copy paper, must at first be removed in order to extract the jammed paper, since the unit itself includes the feeding roller as well as the cassette. SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a copy paper transporting unit for use in an electrophotographic copying apparatus, which is free of the aforementiond drawbacks and which permits easy inspection of the apparatus and removal of jammed copy paper. Another object of the present invention is to provide an improved mechanism for withdrawing a copy paper transporting unit from the body proper or interior of a copying apparatus. Still another object of the present invention is to provide a copy paper transporting unit with simple releasing and locking mechanisms so as to enable easy operation in withdrawing the unit. These and other objects of the present invention are achieved by providing a copy paper transporting unit which extends from the front of the feeding rollers to the discharge end of a copying apparatus, which unit can be withdrawn in the feeding direction of the copy paper and has a mechanism which includes at least a first locking member at the side of the body proper of the apparatus, a second locking member on the unit side for engagement with said first locking member, and releasing means for releasing the locking engagement of said first and second locking members. For a fuller understanding of the nature and objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general cross-sectional view of an electrophotographic copying apparatus which incorporates the copy paper transporting unit of the present invention; FIGS. 2A and 2B are side views of a mechanism for locking and releasing the copy paper transporting unit in a copying apparatus, in which FIG. 2A shows the locked condition and FIG. 2B shows the released condition of the mechanism; FIG. 3 is an exploded perspective view of a locking mechanism for the copy paper transporting unit of the present invention; FIG. 4 is a cross-sectional view showing the relation among the copy paper transporting unit, handle and slide rails; FIG. 5 is a side view of a locking mechanism according to another embodiment of the present invention; and FIG. 6 is a perspective view showing details of the locking mechanism of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, there is shown in image transfer type copying apparatus 1 incorporating a copy paper transporting unit A according to an embodiment of the present invention. An original document to be copied is placed on a transparent glass plate 2a of an original table 2 and is exposed and projected successively onto a photosensitive drum 10 by an optical scanning means including an exposure lamp 3, a first reflecting mirror 4, a second reflecting mirror 5, a projection lens 6 and first and second fixed mirrors 7 and 8. As is well known in the art, first reflecting mirror 4 together with lamp 3 are moved parallel to the original document at twice the speed of second reflecting mirror 5 so as to scan the image of the original and project it onto photosensitive drum 10 through lens 6 and fixed mirrors 7 and 8. Disposed around the photosensitive drum 10 in the direction of rotation thereof are corona charging means 11 for uniformly charging the surface of photosensitive drum 10, a developing means 12 including a magnetic developing roller 13 for developing an electrostatic latent image formed on drum 10, a corona transfer charging means 14 for transferring the developed image onto copy paper, a corona strip charging means 21 for aiding separation of the copy paper from drum 10, a stripping pawl 15 for separating the copy paper from the drum 10, and a cleaning means 16 for removing residual toner from drum 10. Stacks of sheets of copy paper of different sizes are stored in first and second paper cassettes 18a and 18b from which the sheets are adapted to be fed, one by one, by first and second feeding rollers 19a and 19b. Each of these feeding rollers 19a and 19b rests on the topmost sheet of copy paper and is driven intermittently at a speed just sufficient to feed the copy paper to succeeding transporting rollers 20a and 20b. Copy paper is then fed between drum 10 and corona transfer charging means 14 where the developed image is successively transferred onto the copy paper, which is then transported onto an endless transporting belt 22 rotatably supported by a plurality of drive rollers. From here, the copy paper, with the toner image thereon, is further transported to a fixing means 23 having a pair of heating rollers 24a and 24b. As the copy paper is fed between rollers 24a and 24b, the toner image is fused thereon, and the paper is finally discharged out of the apparatus onto a paper receiving tray 26 by a pair of discharging rollers 25. Generally, a copy paper fed by feeding roller 19a or 19b along a feeding path leading to the discharging end of the apparatus most often becomes jammed in one of the following areas. The first area is the paper feeding section I in the vicinity of first or second feeding roller 19a or 19b. Paper jamming at this section is most often caused by misfeeding of the topmost sheet of copy paper by feeding roller 19a or 19b. More specifically, two or more sheets of paper may be fed simultaneously, or paper may be fed obliquely, thereby causing jamming at this section. The second area where jamming often occurs is in the area of the image transfer section II, and this is primarily caused by failure of the copy paper to separate from the surface of photosensitive drum 10. Finally, the third area of jamming is the fixing section III, where heating rollers 24a and 24b are provided. In section III, copy paper often curls around heating roller 24b due to relatively strong adherence of toner on the paper. In the present invention, a jammed copy paper at any of said areas may easily be removed by arranging the feeding path for the copy paper so that it is into a unit which can be withdrawn from the interior of the body proper of the copying apparatus in the feeding direction of the copy paper. More specifically, the feeding path leading from in front of feeding rollers 19a and 19b (i.e., excluding these rollers 19a and 19b) to the discharging end where paper receiving tray 26 is provided, is structured into a copy paper transporting unit A as indicated by one of the broken lines in FIG. 1. This unit A can be withdrawn in the right-hand direction as view in FIG. 1 so that a jammed paper may easily be removed. This also permits easy inspection of the copying apparatus as well as replacement of photosensitive drum 10. The mechanism for withdrawing this copy paper transporting unit A will now be explained with reference to FIGS. 2A through 4. The unit A is withdrawn in the feeding direction of the copy paper along a pair of slide rails 27, one being provided on each side of body proper 60 of the copying apparatus, one side of each rail being on the body 60 and the other being on the unit A itself. As can be best seen in FIGS. 2A, 2B and 3, a paper feeding unit 28 is formed adjacent one end of copy paper transporting unit A and includes spaced opposed side frames 29 which hold first paper cassette 18a and first feeding roller 19a therebetween. The numeral 36 designates a stack of sheets of copy paper stored in the cassette. At the front ends of both of these side frames 29, there is formed an indent 30 into which fits a positioning shaft 38. Also, at the lower part of the front end of each side frame 29, there is provided a first locking member 31 having an engaging notch 32. The lower leading end of each member 31 has an inclined face 33. This first locking member 31 is pivotable about an axis 31a and is normally urged downwardly by a spring 34, with its movement being restricted by a first stop 35. The copy paper transporting unit A includes a pair of side frames 37 extending substantially the length of unit A. As has been mentioned, one side of each slide rail 27 is fixed on frame 37 and cooperates with the other side of slide rail 27 which is fixed on the body proper of the copying apparatus. The positioning shaft 38 briefly described above is fixedly provided between side frames 37 at one end thereof for engagement with indent 30 in each side frame 29. Also provided between side frames 37 is a locking shaft 40 which is rotatably supported and projects outwardly from one of the side frames 37. On this projecting end of locking shaft 40 there is mounted a locking lever 39, with the end thereof toward the paper feeding unit 28 being urged upwardly by a tension spring 43 and the other end being connected to one end of a chain 45. A second stop 48 projecting from side frame 37 restricts the counter-clockwise rotation of locking lever 39. A pair of locking arms 42, each having a second locking member 41, are fixedly attached on the locking shaft 40 in positions between side frames 37 but close to the inner faces of frames 37. As can be seen, the rotation of locking shaft 40 will cause locking lever 39 and locking arms 42 to rotate therewith. Cooperating with chain 45, which has one end fixed to the locking lever 39, is a first sprocket 44 rotatably supported on side frame 37 at a position close to locking lever 39. At the far right end of unit A as viewed in FIGS. 2A and 2B, a second sprocket 47, with which chain 45 is meshed, is rotatably mounted on a handle shaft 46a extending through body proper 60. The outer end of this shaft 46a carries a manually rotatable handle 46 for rotating second sprocket 47. Chain 45 extends from locking lever 39 and meshes with first and second sprockets 44 and 47, and the other end of chain 45 is fixed to a retaining member 45a fixed on side frame 37. Normally the copy paper transporting unit A is in the locked position in the copying apparatus as shown in FIG. 2A. More specifically, positioning shaft 38 of unit A is fully engaged in indents 30 in side frames 29 of feeding unit 28. Similarly, second locking members 41 of locking arms 42 are respectively engaged in engaging notches 32 of first locking members 31 provided on side frames 29. This locked position is maintained by the upward urging force of tension spring 43 connected to locking lever 39. If for some reason, such as for removal of jammed copy paper, the copy paper transporting unit A is to be withdrawn from the interior of the copying apparatus, handle 46 is manually rotated in the clockwise direction as shown in FIG. 2B. The rotation of handle 46 causes second sprocket 47 to rotate therewith so as to drive chain 45 to the right, and the movement of chain 45 rotates locking lever 39, together with locking shaft 40, in the counter-clockwise direction, against the force of tension spring 43, until the rotation of locking lever 39 is restricted by second stop 48. Thus, the engagement of second locking members 41 with the engaging notches 32 of first locking members 31 is released. As handle 46 is further rotated, sprocket 47 drives chain 45 to the right, pulling unit A with it, and positioning shaft 38 disengages from indents 30. As rotation of handle 46 is continued, unit A is moved further to the right so as to be withdrawn from the interior of the copying apparatus. It is to be noted that about 70-80% of the full length of unit A is withdrawn from the interior of the apparatus in its fully withdrawn position. With the unit A withdrawn from the interior of the apparatus, jammed copy paper may be removed. It should be noted that the unit A itself is so designed that its interior is accessible from the top and front of the unit at various areas. To reposition the unit A, it is only required to rotate handle 46 in the counter-clockwise direction, or even to just push the unit A itself to the left. As the unit A slides back, second locking members 41 of locking arms 42 contact inclined faces 33 of first locking members 31 so as to pivot the latter upward against the urging force of springs 34, and as the unit A is moved further to the left, second locking members 41 engage engaging notches 32 of first locking members 31. At this time, positioning shaft 38 locks into indents 30 simultaneously so that the unit A is fully locked in the apparatus. Reference will now be made to FIGS. 5 and 6, showing another embodiment of a mechanism for the copy paper transporting unit A in accordance with the present invention. It should be noted that like parts will be designated by the same numerals as above, and modified parts will be designated by primed numerals. As shown in FIGS. 5 and 6, side frames 29 of feeding unit 28 are designed to have indents 30 as well as first locking members 31'. Each locking member 31' is shaped so as to project from the end of side frame 29 and has an engaging notch 32 and an inclined face portion 33 at its leading end. On the rotatably supported locking shaft 40 running between and through side frames 37 of copy paper transporting unit A, there is rotatably provided a pair of locking arms 42a and 42b, each having a second locking member 41 engagable with engaging notches 32 of first locking members 31'. Adjacent each of locking arms 42a and 42b are stop members 51a and 51b fixedly provided on shaft 40 with each retaining one end of springs 50a and 50b. The other end of each spring 50a and 50b is engaged with a respective one of the locking arms 42a and 42b so as to urge these locking arms in the counter-clockwise direction. It should be realized that locking arms 42a and 42b are rotatably supported on shaft 40, whereas stop members 51a and 51b are fixedly attached on shaft 40. For this purpose, the lower portions of locking arms 42a and 42b have projecting portions 42c which contact stop members 51a and 51b when the locking arms 42a and 42b are at the positions on shaft 40 as shown in FIG. 6. A locking lever 39' is provided at the end of locking shaft 40, fixed thereto by a screw. This locking lever 39' is urged upwardly by a tension spring 43 and carries one end of chain 45. The other end of chain 45 is fixed to retaining member 45a provided at the right end of side frame 37, and chain 45 is guided around roller 42 and meshes with sprocket 47. By the use of roller 52 instead of sprocket 44, as well as by disposing chain 45 to run beneath roller 52, the unit A can be withdrawn further from the interior of the copying apparatus than in the case of the first embodiment, i.e. that shown in FIGS. 2A and 2B. This is apparent since the limit to which the unit A can be withdrawn in the first embodiment is where sprocket 44 contacts sprocket 47. To release the copy paper transporting unit A from the locked position shown in FIG. 5, handle 46 is rotated clockwise thereby causing locking lever 39' to be pulled downwardly against the tension of spring 43. By this action, locking shaft 40 is rotated, causing second locking members 41 of locking arms 42a and 42b to disengage from engaging notches 32 of first locking members 31'. With this, positioning shaft 38 also disengages from indents 30, and as handle 46 is further rotated, the unit A is moved by cooperation of chain 45, roller 52 and sprocket 47. When the unit A is to be repositioned fully back into the interior of the apparatus, handle 46 is rotated counter-clockwise, or unit A is merely pushed, and as the unit A is moved, second locking members 41 of locking arms 42a and 42b first come into contact with inclined faces 33 of first locking members 31' and slide therealong against the urging forces of springs 50a and 50b, and with further movement of unit A, second locking members 41 come into engagement with engaging notches 32 of first locking members 31'. At this time, positioning shaft 38 also fits into indents 30 so that the unit is fully locked in the apparatus. While preferred embodiments of the present invention have been described, it is apparent that numerous alterations, additions and omissions may be made without departing from the spirit of the invention. For example, the sprocket 47 may be driven by a motor so that copy paper transporting unit A can be withdrawn from and moved back into the apparatus automatically.

Electrophotographic copying apparatus comprising a body proper and a copy paper transporting unit which can be slidably withdrawn from the body proper in the feeding direction of the copy paper. The transporting unit houses the entire path of the copy paper, thus permitting easy removal of jammed paper from the apparatus upon withdrawal of the transporting unit from the body proper.

[0001] This application is a continuation-in-part of PCT/IL02/00711 filed Aug. 28, 2002. FIELD OF THE INVENTION [0002] The present invention relates to a mandrel and to a tool for tensioning elastic sleeves such as dust boots, bellows seals and the like, to ease their mounting around mechanical joints and connections, and further relates to a method of using such a device. BACKGROUND OF THE INVENTION [0003] There are many elastic products used in mechanical devices, for covering and protecting joints. A widespread example of such an elastic product is the flexible boot used for enclosing and protecting the point of connection between the driveshaft and the ball joint in automobiles, but there are many other bellows seals, dust boots and the like used for similar purposes in a wide range of industrial and domestic machinery. [0004] Installation and removal of bellows seals and dust boots around a joint, such as in a ball joint, without dismantling the joint, is not easy. One method commonly used for achieving this, is to turn the dust boot inside-out around a widening cone, and then back, outside-in, as it is mounted over the ball joint. This method is time-consuming, tiring for the mechanic and requires expertise. Furthermore, lubricating substances are often required to overcome friction when mounting the boot onto the widening cone, and this makes installation and removal a dirtying occupation. [0005] It is to provide a fast, easy to use tool for facilitating the installation and removal of bellows seals, dust boots and the like, known hereinafter as flexible boots, around joints and other components, that the present invention is directed. [0006] Numerous devices and apparatus have been described in which expansion pins, fingers or levers are mounted to a base and can be made to converge and diverge enabling them to stretch and mount O-rings, rubber tires and elastic sleeve ends. [0007] DE 199 26 617 describes an expansion device for attaching rubber caps to drive links. The device has expansion pins held loosely in holes around the planar outer edge of a flange and a rigid anchoring mechanism to converge the pins. The pins converge and diverge by shifting their angle in the holes. [0008] U.S. Pat. No. 3,605,239 discloses a bulky apparatus for installing resilient seals, such as O-rings. The apparatus includes thin elongated fingers whose base ends are coiled into springs and fixedly retained in a stressed position by a rigid retaining ring. The apparatus is unsuitable for positioning rubber boots over automobile drive shafts, and cannot be hand held. U.S. Pat. No. 2,574,195 describes a bulky apparatus with pivoting fingers for mounting tires onto the rim of wheels. The pivoting of the fingers, however, is restricted by slots in a work support. [0009] GB 1,033,508 discloses an apparatus for positioning a circumferential end of a tube, whose other end is sealed, over a wider body. The apparatus has curved levers with hooked ends pivotally connected to the planar circumference of a ring and extending beyond the perimeter of the ring. The levers cannot extend into the full interior of a tube and therefore cannot be used to mount tubular structures over objects such as mechanical joints. [0010] Japanese patent publication JP 01064735 discloses an apparatus for a similar purpose as that of this invention. However, the structure of the apparatus is completely different. According to this patent, the spokes or fingers can pivot radially only a short distance because their pivot points are close to their centers not at the terminal ends. Therefore, they cannot converge to a cone shape, which limits the type of rubber boots that can be applied with this apparatus. Moreover, the present invention provides a closing device to maintain the spokes normally in a converged (cone shaped) state, and to return the spokes from an expanded state to converged state when a piston is withdrawn from the spokes. SUMMARY OF THE INVENTION [0011] It is an aim of the present invention to provide a tool for facilitating the installation and removal of expandable sleeves such as flexible boots to and from their position around driveshafts, joints and the like, particularly on automobiles. [0012] It is another aim of the present invention to provide such a tool that is easy to use. [0013] It is a further aim of the present invention to provide such a tool that requires no special training to become proficient in its use. [0014] It is yet another aim of the present invention to provide such a tool hat requires little physical exertion on the part of the operator to operate the tool. [0015] It is still a further aim of the present invention to provide such a tool that does not require the use of grease or lubricants to maneuver and position flexible boots. [0016] A further object of the invention is to provide a method of installing and removing expandable sleeves, such as flexible boots, to and from their position external to driveshafts, joints and the like. [0017] In a first aspect of the present invention, there is provided a mandrel for expanding elastic sleeves for easy mounting over and removal from mechanical joints, comprising a base section having a perimeter with an opening therein and a plurality of spokes; each spoke being movably arranged with respect of the base section, such that the mandrel can alternate between a closed state and an open state; such that in the closed state, the plurality of spokes converge at their far ends to form a cone shape and each spoke forms a first angle with the base section, and in the open state, the plurality of spokes move in the opposite direction to assume a second angle with the base section that is substantially larger than the first angle, characterized in that, the base section comprises a crenellated rim with slots between adjacent crenellations, [0018] the plurality of spokes are pivotally mounted at their base ends in the slots between adjacent crenellations of the rim by pins whereby the spokes can pivot only radially to a closed cone position and to an open expanded position, respectively, with respect of the perimeter of the base section, and [0019] a separate closing device is provided to exert a force that serves as a piston returning means for returning a piston from a forward position to a backward position, and for maintaining the mandrel in a closed state. [0020] The closing device is preferably made of rubber and is preferably also a guard element circumscribing the base element and covering at least a section of each of the spokes to protect the pivotal joints and to limit the second open angle of the pivotal spokes. This guard element is resilient, such that it is expanded when the mandrel is in the open position and contracts when the mandrel is in the closed position, urging the spokes to converge. [0021] Alternatively, the closing device may be a plurality of springs, which may be used alone or in combination with a rubber guard element. [0022] Typically, the mandrel will have 3 to 12 spokes equidistantly spaced around the perimeter of the base element. [0023] Preferably, the spokes are detachable from the base section. [0024] The invention further comprises a tool for mounting boots, bellows and seals in automobiles is handheld and comprises a mandrel as described hereinbefore and a drive mechanism for opening the mandrel by pivoting the spokes from a first closed angle to the second open angle and for allowing the spokes to converge from the second angle to the first angle. [0025] The apparatus for opening the mandrel is preferably a piston that reciprocates between a forward position and a backward position, and preferably, there is further provided a driving apparatus for driving the piston, that will typically comprise elements selected from worms, gears, levers, pneumatic apparatus and hydraulic apparatus. [0026] Where hydraulically or pneumatically driven, the driving apparatus comprises a fluid flow regulator attachable to a compressor. [0027] This regulator may comprise an upper chamber having a fluid outlet that is connectable to a connector; a lower chamber having a fluid inlet connectable to the compressor; a conduit having a non-return valve therein, connecting said lower chamber to said upper chamber, enabling fluid to flow from the compressor to the connector; an isolation valve for isolating the upper chamber from the lower chamber, and a release valve for venting the upper chamber. [0028] The non-return valve described above may include a sphere in the conduit, such that when the isolation valve is in an open state, fluid freely flows pas past the sphere, and when isolation valve is in a closed state, the sphere is wedged into the conduit, blocking fluid flow. [0029] The release valve may comprise a hole through the wall of the regulator, and a tapering peg that blocks the hole, such that pressure by an operator on the peg allows air to escape from the upper chamber through the hole. [0030] In another aspect, the invention also relates to a method for expanding elastic sleeves and mounting same over a mechanical joint comprising the steps of: [0031] I. providing: [0032] a) a mandrel, comprising: [0033] 1) a base section defining a perimeter with an opening therein and comprising a crenellated rim with slots between adjacent crenellations, [0034] 2) a plurality of spokes pivotally mounted in slots between adjacent crenellations of the rim by pins whereby the spokes can pivot radially to a closed cone position and to an open expanded position, respectively, with respect of the base section, and [0035] 3) a separate closing device exerting tension on the spokes to maintain the mandrel normally in a closed position, and [0036] b) drive mechanism for driving a piston in contact with the spokes to reciprocate between a forward position and a backward position for opening the mandrel and causing the spokes to move from a first converged angle to a second open angle; [0037] II. sliding a flexible elastic sleeve over the plurality of spokes of the mandrel when they are in their converged position; [0038] III. extending the piston of the drive apparatus forward to urge the spokes to pivotally diverge radially outward, thereby expanding the elastic sleeve and providing an enlarged inner sleeve cavity; [0039] IV. placing the mandrel with the diverged spokes supporting the expanded sleeve over a mechanical joint so that the joint lies within the enlarged inner sleeve cavity, [0040] V. retracting the piston, whereby the closing device urges the spokes to converge, allowing the elastic sleeve to contract over and around the mechanical joint, and withdrawing the mandrel, leaving the joint enveloped by the sleeve. [0041] A particular method for expanding elastic sleeves and mounting same over mechanical joints (typically including a driveshaft) comprises the steps of: [0042] (a) providing: [0043] (i) a mandrel comprising a base section with an opening therethrough mounted on a cylinder having a crenellated rim and a plurality of substantially rigid spokes having base ends and far ends, the base ends being pivotally attached by pivotal joints to the base section, around its perimeter within slots between adjacent crenellations, such that the spokes can pivot to converge to a first closed position, forming a cone shape, and can pivot to a second open position; [0044] (ii) a closing device associated with the mandrel for urging the plurality of spokes to a closed position comprising a resilient guard element surrounding at least a portion of each of the plurality of spokes, to protect the pivotal joints, keep the spokes closed when the mandrel is in an inoperative position, and to restrict the degree of divergence of the spokes when in the open position, and [0045] (iii) a piston for reciprocation through the base section between a forward position and a backward position, such that when the piston is moved forward it urges the spokes apart and the mandrel assumes an open position, and when the piston is moved backward, the resilient guard element urges the spokes to reassume a closed position, [0046] (iv) a driving apparatus for driving the piston, which is typically a pneumatic apparatus or a hydraulic apparatus, [0047] (b) closing the mandrel by bringing spokes into their convergent position; [0048] (c) sliding a flexible elastic sleeve over the plurality of spokes of the mandrel; [0049] (d) urging the spokes to pivotally diverge outward thereby expanding the elastic sleeve and providing an enlarged inner sleeve cavity; [0050] (e) placing the diverged spokes with expanded sleeve over the mechanical joint, so that the mechanical joint lies within the enlarged inner sleeve cavity; [0051] (f) pivotally converging the spokes by retracting the piston, thereby allowing the sleeve to contract over and around the mechanical joint, and [0052] (g) withdrawing the mandrel, leaving the joint enveloped by the sleeve. [0053] Another method for fixing a flexible boot over the head of and around a driveshaft comprises the steps of: [0054] (a) Providing: [0055] (i) a mandrel and drive mechanism as hereinbefore defined, and [0056] (ii) a compressor with a fluid flow regulator, said regulator comprising an upper chamber having a fluid outlet that is connected to a connector; a lower chamber having a fluid inlet connected to the compressor; a conduit having a non-return valve therein, connecting said lower chamber to said upper chamber, enabling fluid to flow from the compressor to the connector; an isolation valve for isolating the upper chamber from the lower chamber, and a release valve for venting the upper chamber; [0057] (b) Sliding a flexible boot over the cone formed from the closed pivoted spokes of the mandrel; [0058] (c) Opening the isolation valve of the regulator, allowing fluid to enter the fluid intake of the lower chamber of the regulator from the compressor, from whence the fluid is forced through the non-return valve, into the upper chamber of the regulator and thence through the connector, to the cylinder of the boot slider, forcing the piston from its backwards position into its forward position, forcing the mandrel to assume the open state, and stretching the flexible boot in so doing; [0059] (d) Inserting the head of the driveshaft through the opened mandrel and flexible boot stretched therearound, and [0060] (e) Venting fluid from the upper chamber of the regulator via the release valve, thus allowing the piston to return to its backward position in the cylinder under influence of the closer, thus allowing the pivoting spokes of the mandrel to converge, and the mandrel to assume its closed state, releasing the flexible boot into its correct position. [0061] The fluid flow regulator for connecting the tool to a compressor, comprises: [0062] (i) an upper chamber having an outlet therefrom that is connectable to said tool; [0063] (ii) a lower chamber having an inlet thereto that is connectable to said compressor; [0064] (iii) a conduit connecting said lower chamber to said upper chamber, allowing fluid to flow therethrough, from said compressor to said upper chamber; said conduit having (iv) a non-return valve therein; [0065] (v) an isolation valve for isolating the upper chamber from the lower chamber, and [0066] (vi) a release valve for venting the upper chamber. [0067] The non-return valve may comprise a sphere in the conduit, such that when isolation valve is in an open state, compressed fluid freely flows past the sphere, but when isolation valve is in a closed state, the sphere is wedged into the conduit, blocking it. [0068] The release valve may comprise a tapering peg that blocks a hole through a wall of the regulator; said hole connecting said conduit to outside of said regulator, such that pressure by an operator on the peg, allows fluid to escape from said upper chamber through said hole. [0069] The term “flexible boot” is used hereinafter, to imply dust boots, cv boots, bellows, seals, sleeves, washers and all other similar elastic or rubber components of mechanical apparatus, that require stretching for installing and removing over the components and connections that they are designed to protect. BRIEF DESCRIPTION OF THE DRAWINGS [0070] The present invention will be further understood and appreciated from the following detailed description taken in conjunction with the drawings in which: [0071] [0071]FIG. 1 is an exploded isometric projection of a first embodiment of the present invention in the open position; [0072] [0072]FIG. 2 is an exploded cross-sectional view of the embodiment of FIG. 1; [0073] [0073]FIG. 3 is an isometric projection of the assembled embodiment of FIG. 1 in the closed position; [0074] [0074]FIG. 4 is an isometric projection of the assembled embodiment of FIG. 1 in the open position; [0075] [0075]FIG. 5 is closed isometric projection of FIG. 3 with a dust boot positioned over the closed spokes of the mandrel; [0076] [0076]FIG. 6 is a cut-away isometric projection of FIG. 4 with a dust boot positioned over the open spokes of the mandrel, and a driveshaft positioned within receptacle of the piston; [0077] [0077]FIG. 7 is an exploded isometric projection of a second embodiment of the present invention; [0078] [0078]FIG. 8 is a schematic cross-sectional view of a regulator for connecting the device of FIGS. 1 to 6 to a compressor; [0079] [0079]FIG. 9 is an exploded isometric projection view of the regulator shown in FIG. 8; and [0080] [0080]FIG. 10 is a flow chart showing how a flexible boot can be correctly positioned using a pneumatic boot slider in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION [0081] FIGS. 1 to 6 show a preferred embodiment of the present invention, known hereinafter as a boot slider. The same parts are annotated by the same reference numbers in all diagrams, but to best appreciate the construction, reference is first made to FIGS. 1 and 2 showing the parts and construction of the boot slider 10 in expanded, isometric projection and cross-sectional view respectively. Thus referring to FIGS. 1 and 2, there is shown, a preferred embodiment of the boot slider 10 consisting of a mandrel 12 that is formed from a plurality of spokes 14 , each having a hole 16 therethrough, near the base ends 15 thereof. There is also shown a base 18 in the form of an annulus having a crenellated rim 19 , allowing the affixation of each pivoting spoke 14 , within a slot 23 between adjacent crenellations, by a pin 21 (FIG 3 ). Fitting over and around the crenellated rim 19 of the base 18 , there is provided a resilient guard element 20 , illustrated herein as an annular ring 5 with a truncated conical extension 7 covering at least a portion of the spokes 14 that prevents the plurality of spokes from pivoting outwards from the base and urge them to converge to a cone shape. The base 18 is affixed into the expanded mouth 22 of a cylinder 24 , within which there is provided a piston 26 that can reciprocate between a forward position and a backward position within the cylinder 24 . The mouth of the piston 26 widens into a receptacle 28 . Extending outwards from the piston 26 , around the base of the receptacle 28 there is provided a flange 30 . Below the piston flange 30 , to provide sealing between piston 26 and cylinder 24 , there is provided a gasket 32 . Also provided, there is at least one closing device 34 that serves as a piston returning means, for returning the piston from its forward position to its backwards position. As illustrated herein, the closing device 34 may be a plurality of springs that fit around the outside of the receptacle 28 and within the base 18 , such that when piston 26 is in its forward position, the closing device 34 exerts a force on the piston flange 30 , that tends to drive the piston backwards. Affixed to the base of the cylinder 24 , there is shown a connector 38 , allowing the boot slider 10 to be connected, via an appropriate regulator, to a source of compressed air or a fluid, for pneumatic or hydraulic operation. [0082] The guard element 20 may be made of a resilient material such as rubber for example. Other parts will generally be made of metal/alloy, such as steel, but alternatively, could be fabricated from other materials such as an engineering plastic. [0083] Referring now to FIGS. 3 and 4, showing the assembled boot slider 10 with guard element 20 removed for clarity. The mandrel 12 can assume two states: a closed state (FIG. 3), and an open state (FIG. 4). In the closed state (FIG. 3), the piston 26 is in its backwards position, and the spokes 14 of the mandrel 12 are pivoted inwards, so that they converge towards each other, each spoke 14 situated at an acute angle with the base 18 , and the mandrel 12 having a conical or frustoconical shape. [0084] In the open state (FIG. 4), the piston 26 is in its forwards position, and the spokes 14 of the mandrel 12 are forced open, so that each spoke 14 is situated at a larger angle with the base 18 than in the closed state and the spokes 14 of the mandrel 12 are less convergent than in the closed state. As illustrated herein, in the open state, the spokes 14 lie perpendicular to the base 18 , the mandrel 12 assuming an essentially cylindrical shape. [0085] It will be appreciated however, that the terms “open” and “closed” are relative, with the degree of opening being a function of the length of the spokes, the height of the guard element and the size and shape of the base, and the degree of opening and closing desired are application specific. The spokes of the mandrel in the open state may converge at a shallower angle to the convergency of the closed state. Alternatively, they may lie parallel to each other, or they may diverge, the mandrel assuming a reversed frustoconical shape thereby. [0086] Referring now to FIG. 5, the boot slider 10 is shown in its closed state with a conical flexible boot 50 placed over the conical converging spokes 14 of the mandrel 12 . Driving the piston forwards within its cylinder, forces the spokes 14 to open up radially, and the mandrel 12 assumes its open state, shown in FIG. 6, with the stretched flexible boot 50 pulled into a cylindrical shape. Due to the wide mouthed receptacle 28 at the end of the piston 26 , the bulbous head 62 of a large driveshaft 60 can be accommodated within the receptacle 28 . [0087] It will now be apparent that the boot slider 10 allows a flexible boot 50 to be stretched open, so that a driveshaft 60 can be passed therethrough, facilitating the correct positioning of the flexible boot 50 around a joint with ease. [0088] Having disclosed the device shown herein, it will be appreciated that the basic design of the boot slider illustrated herein, is subject to many modifications. The sleeve and pivoting shafts may be co-engineered to allow the shafts to “close” and “open” to other angles, wider or narrower than the angles illustrated in FIGS. 2 and 4, for example. Furthermore, although FIG. 6 shows a flexible boot being positioned over a driveshaft, the boot slider disclosed herein is readily adaptable to other applications requiring the stretching and positioning of a flexible boot or similar elastomeric or rubbery sleeve for protecting or covering other machine parts. [0089] A plurality of spokes are required to provide the mandrel of the boot slider for tensioning flexible boots. In the embodiment shown herein in FIGS. 1 to 5 , eight spokes 12 are shown. For most applications, the exact number is not critical. [0090] With reference to FIG. 7, there is shown a second embodiment wherein, the spokes 114 of the mandrel 112 are not directly connected to the base 118 of the boot stretcher 100 , but fit into arm guides 115 . Being detachable, the number of spokes can be varied for different applications. Minimally, as shown herein, 2 spokes are required, but for most applications, a larger number is preferable. The crenellated base 118 as illustrated, can accommodate up to 8 spokes. Other bases may be fabricated to accommodate other numbers. Furthermore, the guard element 120 comprises a truncated cone section 7 integral with an annular ring section 5 for covering the crenellated base 18 and is manufactured from an elastic material, such as rubber, and is designed to resist deformation to the extent that, in addition to resisting the spokes 114 of the mandrel 112 from opening to too large an angle, the guard element 120 further serves as a closing device, causing the spokes 14 to converge and the mandrel to assume its closed state when the extending force on the piston 126 is relieved. No further closing device is required, and the base 118 may be rigidly attached to the expanded mouth 122 of the cylinder 124 , by a screw-thread, for example. This lack of additional, separate closing device is in contradistinction to the additional closing device 34 distinct from the guard element 120 , that is a requirement of the first embodiment described hereinabove, and illustrated as a plurality of springs in FIGS. 1 and 2. [0091] It will be appreciated, that the operating force for forcing the piston forwards within the cylinder to open the pivoting shafts, may conveniently be applied by a variety of driving systems, including mechanical means, such as a worm, which may be motorized or hand-operated. Alternatively, the forward urging force may be applied by a class one lever, such as a pincer/plier type of apparatus including a pair of handles arranged to pivot around an axis below the piston. Mechanical means may also include gear systems and other elements as known in the art. [0092] For convenience and ease of use however, in workshops having suitable auxiliary equipment, a driving system utilizing hydraulic pressure or pneumatic pressure may be used. [0093] Referring now to FIG. 8, there is shown, in schematic cross-section view, a regulator 70 for connecting the boot slider 10 to an air compressor (not shown), it being appreciated that car workshops are generally fitted up with air compressors. The regulator 70 has two chambers connected by a conduit 82 containing a non-return valve and a release valve 85 a lower chamber 72 having an air intake 74 thereto, for connecting to the compressor, and an upper chamber 76 having an air outlet 78 therefrom, that connects to the air connector 38 of the boot slider 10 (see FIGS. 1-5). As illustrated herein, the regulator 70 is coupled to the air connector 38 using a screw threaded fitting 75 , but any other suitable coupling means known in the art, such as an appropriate quick-fit mechanism may be used. [0094] The first chamber 72 is connected to the second chamber 76 via a non-return valve, illustrated herein as a unidirectional ball valve 80 , consisting of a sphere 81 in the conduit 82 . The ball valve 80 allows air to flow through the regulator 70 from the compressor to the boot slider, but not back again. Also provided there is a middle part 92 that serves as an isolating valve, that enables isolation of the upper chamber 76 from the lower chamber 72 by it being rotated, and an air release valve 85 that allows compressed air from the upper chamber 76 to be vented, releasing the pressure in the upper chamber. [0095] [0095]FIG. 9 shows the components required to manufacture an exemplary regulator of this type for connecting the boot slider to a source of compressed air, wherein the regulator comprises a bottom part 90 , a middle part 92 and an upper part 94 that interlock together, gaskets 96 being provided between the parts to provide air-tight sealing. Also shown is the release valve 85 . Of note in the novel regulator illustrated, the release valve 85 sits in the same conduit as the ball valve 80 . The ball valve consists of a sphere 81 that sits in the conduit 82 between the bottom part 90 and middle part 92 , allowing air to flow therethrough when the regulator 70 is in the open position. Rotating the regulator into the closed position causes the sphere 81 to be tightly wedged into the conduit 82 , thereby closing off the conduit 82 and isolating the upper chamber 76 from the lower chamber 72 . The release valve 85 consists of a tapering peg 86 , typically having a somewhat frustoconical geometry that fits into a hole 87 connecting the conduit 82 to the outside of the regulator 70 . Air pressure within the upper chamber 76 keeps the tapering peg 86 pushed outwards, and tightly rammed against the wall of the hole 87 . When the regulator 70 is in the closed position however, with the middle part 92 being rotated, causing the sphere 81 to be blockingly wedged into the conduit 82 , the tapering peg 86 may be pushed inwards by the operator, allowing air trapped in the upper chamber 76 to be vented through the hole 87 to the outside, and thereby releasing the pressure on the cylinder, allowing it to move backwards within the piston, and thereby allowing the mandrel to reassume its closed state. [0096] The compressed air flow regulator described hereinabove thus serves to regulate the mechanical means for opening the mandrel, moving the array of spokes thereof, from their closed position to their open position. This, together with the closing means, generally a resilient device that resists deformation, such as a spring, that moves the array of spokes from their open position to their closed position, provide a system for opening and closing the mandrel. [0097] Hydraulic systems similar in function to the pneumatic system described above may be used instead. [0098] Referring now to the flow diagram of FIG. 10, and referring back to FIGS. 1-6, to operate the boot slider 10 pneumatically, the following steps are required: [0099] (Step 1) A flexible boot is slid over the cone formed from the closed pivoted shafts of the boot slider (FIG. 5). [0100] (Step 2) The isolation valve of the regulator is opened, allowing compressed air to enter the upper chamber of the regulator from the compressor, and thence through the connector, to the cylinder of the boot slider. The compressed air entering the boot slider forces the piston from its backwards position into its forward position, forcing the spokes 14 of the mandrel 12 to assume the open position (FIG. 4), stretching the flexible boot 50 in so doing. [0101] (Step 3) The head 62 of the driveshaft 60 may now be inserted through the opened mandrel 12 and flexible boot 50 stretched therearound, into the wide mouthed receptacle 28 at the end of the piston 26 . [0102] (Step 4) Closing the isolation valve, thus isolating upper chamber of regulator from the lower chamber thereof. [0103] (Step 5) Venting air from the upper chamber of the regulator via the release valve, thus allowing the piston 26 to return to its backward position in the cylinder 24 under influence of the closing means 34 . [0104] This allows the pivoting spokes 14 of the mandrel 12 to converge, and the mandrel 12 to assume its closed state, releasing the flexible boot 50 into its correct position. [0105] It will be appreciated of course, that in alternative embodiments, the system for opening and closing the mandrel may be configured in many diverse ways which, though structurally different, are, nevertheless functionally equivalent. Thus the closing means may be a piston with an appropriate driving system, whether mechanically, hydraulically or pneumatically driven, and the opening means may be a resilient member that resists deformation and acts as a counter to the closing means. [0106] Additionally, the novel regulator illustrated in FIGS. 8 and 9 may, perhaps with minor alterations, be applied to allow the pneumatic operation of other power tools. [0107] It will be appreciated therefore, that the invention is not limited to what has been described hereinabove merely by way of example. Rather, the invention is limited solely by the claims which follow, wherein the word comprise and variations thereof, such as comprises, comprising and the like, imply that the specified components or steps are included, but not generally to the exclusion of other components or steps.

A tool for expanding flexible rubber boots such as cv boots, bellows and seals for easy mounting over and removal from mechanical joints including a mandrel having a base section with a perimeter having an opening and a plurality of spokes, each spoke being movably arranged with respect of the base section, to move from a first converged angle to a second open angle, and from a second open angle to a converged first angle, opening and closing the mandrel. The base section includes a crenellated rim with slots between adjacent crenellations, and the plurality of spokes are pivotally mounted in the slots between adjacent crenellations of the rim by pins, whereby the spokes can only pivot radially from a closed position to an open position with respect of the base section, and vice versa. A closing device exerts tension on the spokes to maintain the mandrel normally in a closed position and when the mandrel is opened by a drive mechanism in contact with the spokes, the device will urge the mandrel to close as the drive mechanism is retracted from the spokes.

This application is a continuation of prior U.S. application Ser. No. 595,958, filed Apr. 2, 1984, now abandoned. BACKGROUND OF THE INVENTION The present invention relates to motor driven rotary cultivating devices having particular utility for front-end earth working. More specifically, the invention relates to the manner of supporting and interconnecting support wheels and drag bar to ensure that the wheels and drag bar move simultaneously between a working position and a transport position and to the location and orientation of the drag bar in its working position allowing it, in the preferred embodiment, to extend slightly rearward at an angle to the vertical providing a self-cleaning feature. Pivotally mounted drag bars for use in controlling the cultivating or tilling functions of a walk-behind device are well known. Moreover, drag bars whose position is controlled by the adjustment of wheel position are also disclosed in prior art. U.S. Pat. No. 4,164,983 issued to Hoch on Aug. 21, 1979 discloses a walk-behind tiller with singularly mounted drag stake and wheels which patent is representative of the type of device here under consideration. Specifically, this Hoch patent discloses the use of a pivotable over center wheel mounting arrangement, which arrangement controls the position of the drag bar. The arrangement is adjustable for movement between two positions, an extreme forward position for establishing a transport condition and an extreme rearward position for establishing a working position. The patent also discloses the use of a bracket which constitutes the sole means for interconnecting and attaching the wheels and drag stake to the frame. SUMMARY OF THE INVENTION Accordingly it is a principal object of the present invention to provide an improved manner of interconnecting separately mounted support wheels and drag stake in a motor driven rotary cultivating device. Another object of the invention is to provide a motor driven rotary cultivating device with a pair of separately mounted support wheels and drag stake interconnected by means of a sliding collar bar attached to the wheel axle such that the drag stake enters the ground rearwardly of the wheel axle. Another object is to provide such a device having a pair of wheels and drag stake mounted separately relative to the main chassis and such that the wheels are easily moveable between a forward transport position and a rearward working position and the drag stake is easily moveable between a raised transport position and a lowered working position. Yet another object is to provide a device with a sliding collar bar for interconnecting the support wheels and drag stake which vastly simplifies the mounting construction as found in prior art by making the structural arrangement of the drag stake and wheel assembly more compact and efficient. Yet another object is to provide a device having a drag stake which is constructed and mounted in a manner permitting vertical adjustment thereof. A more specific object is to provide a device having a drag stake as described in the preceding objects with the drag stake inclined slightly rearwardly and downwardly toward its lower earth engaging end to provide a self-cleaning feature. A better understanding of the objects, advantages, features, properties and relations of the invention will be obtained from the following detailed description and accompanying drawings which set forth an illustrative embodiment and are indicative of the various ways in which the principles of the invention are employed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partly broken away, of a motor driven rotary cultivator constructed in accordance with the present invention and showing the respective transport positions of the wheels and drag stake in solid lines and showing the respective working positions of the wheels and drag stake in broken lines. FIG. 2 is an enlarged side view of certain elements of the cultivator of FIG. 1 illustrating the respective working positions of the wheels and drag stake. DESCRIPTION OF THE PREFERRED EMBODIMENT A general description of the invention will be made first in connection with FIG. 1. The cultivating device, indicated in its entirety by reference numeral 10, includes a main chassis 12 defined by a pair of channel members, only one shown at 14, having inner flanges (not shown) on opposite sides of and bolted, as at 18, to a chain case 20 which inclines downwardly and forwardly relative to the chassis 12. Mounted on chassis 12 is an internal combustion engine 30 having an engine output shaft 32. Arranged downward to the front of the engine shaft 32 is a shaft 34 which is located in the upper end of chain case 20, and provided for transferring the rotation of engine shaft 32 to shaft 34 is a drive belt 36, which is disposed about a small pulley 38 fixed to engine shaft 32 and a larger pulley 40 fixed to shaft 34. Journalled in the lower end of chain case 20 is a tine drive shaft 42 to which a plurality of tines or blades 44 are affixed. Rotation of shaft 34 is transferred to tine shaft 42 by means of a chain and drive mechanism (not shown) of conventional construction. As appears in solid lines in FIG. 1, a support wheel assembly 100 and a drag stake 120 are disposed in their respective forward transport position. Drag stake 120 is fixed to a rear end portion of chassis 12 by means of a mounting bracket 70. Specifically, bracket 70 comprises opposed plates, only one shown at 71, each having first portions spaced apart and respectively embracing a rearward portion of chassis 12 and being secured thereto by means of two bolts, as at 74, which extend through aligned sets of holes provided in the rear portion of the chassis 12 and plates 71. Bracket plates 71 are provided with a further set of holes such as at 66 which align with a set of holes 68 located in drag stake 120 to position drag stake 120 to a desired depth in the earth. Drag stake 120 is positioned at a desired depth by inserting a locking device 67, such as a hitch pin, washer and hairpin, into the aligned set of holes in bracket plates 71 and the drag stake opening 68. A third set of holes 60 is located in the lower forward section of bracket plates 71 which hold a lock device 62. Lock device 62, shown here as a hitch pin, washer and hairpin assembly, secures wheel axle 22 in either the forward transport position or the rearward working position and must be removed to allow wheel assembly 100 to pivot from one position to the other. Wheel assembly 100 includes a pair of legs, only one shown at 124, embracing outer surfaces of channel members 14, a pair of wheels, only one shown at 128, mounted for rotation about wheel axis 22 and a sliding collar bar 140 joined at the central portion of the wheel axle 22 by weldments. Legs 124 embrace channel members 14 at a hitch pin assembly 130 which defines an axis about which wheel assembly 100 may be swung from a forward position disposing wheel assembly 100 and drag stake 120 in respective transport positions, as shown in solid lines in FIG. 1, to a rearward position disposing wheel assembly 100 and drag stake 120 in their respective working position, as illustrated in broken lines in FIG. 1. A more detailed description of the structure and operation of the motor driven rotary device will now be made with reference to FIG. 2 which illustrates the same components as in FIG. 1 but on an enlarged scale. As appears in FIG. 2, support wheel assembly 200 and drag stake 220 are disposed in their respective working positions. Wheel assembly 200 is attached to chassis 112 by means of a hitch pin assembly 230. Specifically, hitch pin assembly 230 comprises a rod 232 which extends through axially aligned sets of holes provided in channel members 114, two flat washers 117 located on the outer surfaces of the legs 224, and hair pin 238 which passes through a hole located in the rod 232. Hitch pin assembly 230 is located at the rear of chassis 112 and defines an axis about which wheel assembly 200 may be swung from a forward position disposing wheel assembly 200 and drag stake 220 in respective transport positions, to a rearward position disposing wheel assembly 200 and drag stake 220 in respective working positions. Wheel assembly 200 includes two metal legs (such as at 224 extending from opposite channel members such as at 114) attached to wheel axle 122 by weldments, not shown, and a pair of wheels 228 rotatably mounted to axle 122. Metal legs 224 extend downward from channel members 114 and 116 from hitch pin assembly connections such as at 230. A sliding collar bar 240 projects centrally from weldments behind wheel axle 122 to enclose drag stake 220 within a narrow rectangular groove. Sliding collar bar 240 guides drag stake 220 into either the transport position or working position when wheel assembly 200 is shifted about pivot 230 such as by removing locking device 162. The interconnecting of drag stage 220 and wheel assembly 200 permits drag stake 220 and wheel assembly 200 to be moved into the desired positions simultaneously without the removal or adjustment of separate nuts and pins. Drag stake 220 comprises an elongate flat bar 223 having a series of holes 168 provided within the upper portion thereof and having a lower end 221 adapted to penetrate the ground. Drag stake 220 is attached to the rear portion of chassis 112 by means of a bracket 170 which is affixed to the rear end portion of chassis 112 by bolts, as at 174. Drag stake 220 projects centrally between closely spaced portions of a pair of bracket plates (only one shown at 171) with those portions having cooperating parts fixed together through a first opening 106, by which lock member 167 in the illustrated form of a hitch pin, washer and hairpin respectively, pass. Lock member 167 also forms the means for confining drag stake 220 between plates 171. First opening 166 provided in plates 171 registers with a selected one of stake holes 168 and lock member 167 through opening 106 and is received in selected hole 168 and secured into position to hold stake 220 in a selected position in an angle slightly inclined to the vertical for entering the ground to a desired depth when stake 220 is in its working position. The inclined angle of stake 220 relative to the vertical allows stake 220 to be self-cleaning. The angle of the stake is such that upon engaging the earth in its working position, the soil is pushed around the stake edges. No accumulation of soil occurs. Another opening 160 is provided in plates 171 such that lock device 162, shown here as a hitch pin, washer and hairpin assembly, may be inserted to hold wheel axle 122 in either of the transport or working positions. When in the transport position, lock device 162 must be removed from plates 171 to allow the wheel assembly 200 to pivot about hitch pin assembly 230 into the working position. The necessity of reinserting lock device 162 to fix wheel assembly 200 in the working position is dependent upon operator preference and the working conditions. However, lock device 162 can be reinserted to hold wheel axle 122 in the rearward working position and prevent axle 122 from swinging into forward transport position. Lock device 162 can be used to hold wheel axle 122 in the forward transport position when wheel assembly 200 is so disposed. Referring once again to FIG. 1, a hole (not shown) is provided for in the top of bracket 70 into which lock device 62 may be inserted. With lock device 62 out of opening 60, wheel assembly 120 can be swung between forward transport position and rearward working position to compensate for varying working conditions by lifting the backend of device 10 off the ground and in a flicking motion of the handle bars 50 alternate wheel assembly 100 between the two positions. As illustrated in FIG. 1, the motor driven rotary device 10 includes a rearwardly projecting handle 50 including a pair of legs, such as the one shown at 52, attached by bolts 54 to chassis channel members 14. The operation of the motor driven rotary device is as follows. With wheels 100 and drag stake 120, through interconnection of sliding collar bar 140, being disposed in its forward position, shown in solid lines in FIG. 1, and with the power transmission between pulleys 32 and 34 being interrupted, power driven rotary device 10 is ready to be transported since drag stake 120 and wheels 100 are then respectively in their raised and forward transport position. Transporting of the power driven rotary device is accomplished by pivoting device 10 back on wheels 100, by pressing downward on handles 50 and then by pushing or pulling the device to a desired work site. The power driven rotary device is then readied for operation by removing lock pin 62. Rotary driven power device is then pushed forward by use of handles 50 which causes wheel assembly 100 to pivot backwards at hitch pin 130, wherein wheel assembly 100 and drag stake 120 are in their rearward working position, as illustrated in broken lines in FIG. 1. Drive belt 36 is then tensioned by means not shown to establish a driving relationship between engine 30 and tines 44. If drag stake 120 has not penetrated the ground to the extent that wheels 128 rest upon the ground, the operator may effect such result by adjusting the vertical position of stake 120. Drag stake lock pin 67 is then replaced in its proper location. Lock pin 62 may be replaced in bracket opening 60 if necessary. To again ready power driven rotary device for transport, the operator needs only remove lock pin 62 (if necessary). Wheel assembly 100 is then free to pivot about hitch pin 130 and the operator can easily place the device in its transport position by pulling on handles 50 toward himself. Once in its transport position, wheel assembly 100 and axle 122 are held in place by reinserting lock pin 62. As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of this invention.

The support wheels and drag stake of a motor driven cultivating device are connected to the main frame of the device by independent mounting brackets at a location rearward of the tines. The support wheels and drag bar are interconnected by a sliding collar-bar which is rigidly attached to the axle of the wheels, thereby allowing for the simultaneous pivoting of drag stake and support wheels between a forward transport position, wherein the drag stake is in an inactive elevated position, and a rearward working position, wherein the drag stake is disposed at an angle off of the vertical for engaging the earth and retarding the forward progress of the device.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation application of U.S. patent application Ser. No. 13/550,282 entitled “RADIOPHARMACEUTICAL CZT SENSOR AND APPARATUS” filed on Jul. 16, 2012; which claims priority to U.S. Provisional Patent Application No. 61/508,402 entitled “RADIOPHARMACEUTICAL CZT SENSOR AND APPARATUS” filed on Jul. 15, 2011; and U.S. Provisional Patent Application No. 61/508,294 entitled “SYSTEMS, METHODS, AND DEVICES FOR PRODUCING, MANUFACTURING, AND CONTROL OF RADIOPHARMACEUTICALS-FULL” filed on Jul. 15, 2011. The entirety of each of U.S. Provisional Application Nos. 61/508,402 and 61/508,294 are incorporated by reference herein. BACKGROUND [0002] I. Field [0003] Aspects of the present invention relate generally to gamma ray sensors, and more particularly to methods and devices for detecting radioisotope concentration, activity and volume using gamma ray detection with cadmium zinc telluride (CZT) solid state detectors. [0004] II. Background [0005] Diagnostic techniques in nuclear medicine generally use radioactive tracers which emit gamma rays from within the body. These tracers are generally short-lived isotopes linked to chemical compounds which permit specific physiological processes to be studied. These compounds, which incorporate radionuclides, are known as radiopharmaceuticals, and can be given by injection, inhalation or orally. One type of diagnostic technique includes detecting single photons by a gamma-ray sensitive camera which can view organs from many different angles. The camera builds an image from the points from which radiation is emitted, and the image is electronically enhanced and viewed by a physician on a monitor for indications of abnormal conditions. [0006] A more recent development is Positron Emission Tomography (PET), which is a more precise and sophisticated technique using isotopes produced in a cyclotron, where protons are introduced into the nucleus resulting in a deficiency of neutrons (i.e., becoming proton rich). [0007] The nucleus of a radioisotope usually becomes stable by emitting an alpha and/or beta particle (or a positron). These particles may be accompanied by the emission of energy in the form of electromagnetic radiation known as gamma rays. This process is known as radioactive decay. [0008] A positron-emitting radionuclide is introduced into the body of a patient, usually by injection, and accumulates in the target tissue. As the radionuclide decays, a positron is emitted, and the emitted positron combines with a nearby electron in the target tissue, resulting in the simultaneous emission of two identifiable gamma rays in opposite directions, each having an energy of 511 keV. These gamma rays are conventionally detected by a PET camera, and provide a very precise indication of their origin. PET's most important clinical role is typically in oncology, with fluorine-18 (F-18) as the tracer, since F-18 has proven to be the most accurate non-invasive method of detecting and evaluating most cancers. Fluorine-18 (F-18) is one of several positron emitters (including also, Carbon-11, Nitrogen-13, and Oxygen-15) that are produced in a cyclotron and are used in PET for studying brain physiology and pathology, in particular for localizing epileptic focus, and in dementia, psychiatry and neuropharmacology studies. These positron emitters also have a significant role in cardiology. F-18 in FDG (fluorodeoxyglucose) has become very important in detection of cancers and the monitoring of progress in cancer treatment, using PET. A radioactive product such as F-18 in FDG is a specific example of a radiopharmaceutical. [0009] F-18 has a half-life of approximately 110 minutes, which is beneficial in that it does not pose a long-term environmental and/or health hazard. For example, after 24 hours, the radioactivity level is approximately 0.01% of the product when freshly produced in a cyclotron. However, transport time from the production source to clinical use should be minimized to retain a maximum potency for accurate diagnostic value. [0010] Whereas PET cameras are effective in imaging uptake of F-18 present in administered FDG, PET cameras are generally too large and ineffective in production settings where characterization of the source product, and not physiological response, is the goal. There is a need, therefore, for a method and apparatus to timely calibrate the radioactivity of a sample at the production source and time of production or packaging for delivery so that the level of radioactivity is predictably known at the time of use. SUMMARY [0011] The following presents a simplified summary of one or more aspects of a method and apparatus for detecting radioisotope concentration, activity and sample volume. [0012] In one example aspect of the invention, a gamma ray detector may include a gamma ray detecting rod elongated in one direction to a specified length, and a gamma ray shield encapsulating the rod, the shield having an opening opposite an end of the elongated rod to admit gamma rays substantially parallel to the long axis of the elongated rod, wherein the long axis of the rod and the opening are directed toward a volume of gamma ray emitting material observable by the detector on the basis of the length of the elongated rod and the opening in the gamma ray shield. [0013] In another example aspect of the disclosure, an apparatus for detecting a volume concentration and activity of a radionuclide content in a container includes a container of known dimensions for receiving the radionuclide. A first gamma ray detector is arranged below the container with respect to gravity and directed toward the container. A second gamma ray detector is arranged above the container with respect to gravity and opposite the first gamma ray detector, and directed toward the container. Detection circuitry and a processor are coupled to the first and second gamma ray detectors, wherein the processor is configured to measure radiation intensity received at the first and second gamma ray detectors and determine a level of content of radionuclide in the container on the basis of the radiation detected by the first and second gamma ray detectors. [0014] To the accomplishment of the foregoing and related ends, the one or more example aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. These aspects are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the described aspects are intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS [0015] These and other sample aspects of the invention will be described in the detailed description that follow, and in the accompanying drawings, wherein: [0016] FIG. 1 is a conceptual illustration of a gamma ray collimated detector in accordance with various aspects of the invention; [0017] FIG. 2 is a conceptual side illustration of the detector of FIG. 1 , in accordance with various aspects of the invention; [0018] FIG. 3 is a conceptual circuit diagram for measuring gamma rays with the detector of FIGS. 1 and 2 , in accordance with various aspects of the invention; [0019] FIG. 4 is a conceptual illustration of an apparatus for measuring concentration, activity and content volume of a radiopharmaceutical using the detector and circuitry of FIGS. 1-3 in accordance with various aspects of the invention; [0020] FIG. 5 presents a conceptual processing system for measuring the content volume of the radiopharmaceutical in the apparatus of FIG. 4 , in accordance with various aspects of the invention; [0021] FIG. 6 presents a flowchart of the functions of components of a flexible programmable gate array (FPGA) of the processing system of FIG. 5 , in accordance with various aspects of the invention; [0022] FIG. 7 is a plot of gamma ray activity in counts per second (cps) of a top detector and a bottom detector of the apparatus in FIG. 3 as a container between the two detectors is filled, in accordance with various aspects of the invention; [0023] FIG. 8 is a logarithmic plot of the ratio of counts in the top detector to the bottom detector as a function of fill level in the container of the apparatus of FIG. 3 , in accordance with various aspects of the invention; [0024] FIG. 9 presents an exemplary system diagram of various hardware components and other features, for use in networking the apparatus for measuring concentration, activity and content volume, in accordance with various aspects of the invention; and [0025] FIG. 10 is a block diagram of various exemplary system components for providing communications with and between various components of the apparatus for measuring concentration, activity and content volume, in accordance with various aspects of the invention. [0026] In accordance with common practice, some of the drawings may be simplified for clarity. Thus, the drawings may not depict all of the components of a given apparatus (e.g., device) or method. Finally, like reference numerals may be used to denote like features throughout the specification and figures. DETAILED DESCRIPTION [0027] Various aspects of methods and apparatus are described more fully hereinafter with reference to the accompanying drawings. These methods and devices may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of these methods and apparatus to those skilled in the art. Based on the descriptions herein teachings herein one skilled in the art should appreciate that that the scope of the disclosure is intended to cover any aspect of the methods and apparatus disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of a claim. [0028] In a radiopharmaceutical production facility, a cyclotron may be used to prepare a bolus of a material containing a radioisotope of interest which is delivered to a synthesis system. The radioisotope may emit one or more kinds of radiation, including electrons, positrons, gamma rays/x-rays, protons, neutrons, alpha particles, and other possible nuclear ejecta. In one example, a radioisotope, when added to other materials to be administered to a subject, may emit a positron, which then annihilates with an electron, for example, in human tissue, to produce gamma rays. [0029] Aspects of the current invention describe a gamma ray detector and methods of measuring the activity, concentration, and volume of a liquid radionuclide as it fills or is drained from a container. In the production of radiopharmaceuticals, the radionuclide may be introduced into a molecular vehicle by chemical synthesis to produce the radiopharmaceutical. Various dosage, concentration, activity and volume requirements for differing medical applications may generally result in splitting, dilution and redistribution of the radioisotope for the production of the various radiopharmaceuticals, wherein a sensor monitors the various production processes. [0030] FIG. 1 shows a schematic illustration of a gamma ray collimated detector 100 . According to various aspects, the sensor 100 may include a cadmium zinc telluride (CdZnTe, or CZT) element 110 . However, other solid state materials such as, e.g., other solid state materials, currently available or yet to be discovered may be used. CZT is a direct bandgap semiconductor and can operate in a direct-conversion (e.g., photoconductive) mode at room temperature, unlike some other materials (particularly germanium) which may require cooling, in some cases, to liquid nitrogen temperature. Advantages of CZT over germanium or other detectors include a high sensitivity for x-rays and gamma-rays that is due to the high atomic numbers and masses of Cd and Te relative to atomic numbers and masses of other detector materials currently in use, and better energy resolution than scintillator detectors. A gamma ray (photon) traversing a CZT element 110 liberates electron-hole pairs in its path. In operation and according to various aspects, a bias voltage applied across electrodes 115 (not shown in FIG. 1 ) and 116 on the surface of the element 110 (both shown in a side view in FIG. 2 ) causes charge to be swept to the electrodes 115 , 116 on the surface of the CZT (electrons toward an anode, holes toward a cathode). According to various aspects, wires 125 and 126 may connect electrodes 115 and 116 , respectively, to a source of the applied voltage. [0031] According to various aspects, the sensor 100 can function accurately as a spectroscopic gamma energy sensor, particularly when the element 110 is CZT. However, geometric aspects may be considered. In conventional use of CZT as a gamma ray detector, the CZT element 110 may be a thin platelet, sometimes arranged in multiples to form arrays for imaging, generally perpendicularly to the source of gamma ray emission. Therefore, gamma rays of differing energies all traverse a detector element of substantially the same thickness. While absorption of the gamma ray may generally be less than 100% efficient, higher energy gamma rays may liberate more electron-hole pairs than lower energy gamma rays, producing a pulse of greater height. The spectrum and intensity of gamma ray energies may thus be spectroscopically determined by counting the number of pulses generated corresponding to different pulse heights. [0032] According to various aspects, because higher energy photons may travel a greater distance in the CZT rod 110 before complete absorption, it is advantageous for the CZT rod 110 to be greater in length in a direction longitudinally (i.e., a long axis) intersecting a known source volume of radionuclide being measured. Gamma rays incident on the CZT rod off or transverse to the long axis may not be fully absorbed, and thus, the CZT rod may not be as sensitive a detector of such gamma rays as a result. Thus, according to various aspects, elongating the CZT rod in one direction introduces a degree of collimation and directional sensitivity along the extended direction. [0033] According to various aspects, the absorption coefficient for 511 keV gamma ray absorption in CZT is μ=0.0153 cm 2 /gm. The absorption probability as a function of μ, density ρ (=5.78 gm/cm 3 ) and penetration distance h is p(μ, h)=1−e −μph . [0034] Therefore, the ratio of absorption in a 10 mm length of CZT to a 1 mm length is [0000] P  ( μ , 10   mm ) P  ( μ , 1   mm ) ∼ 9.613 . [0000] That is, the directional sensitivity for gamma ray detection of CZT at 511 keV along the 10 mm length of the detector is nearly 10 times greater than in the 1 mm thick transverse direction. [0035] Referring to FIGS. 1 and 2 , according to various aspects, the sensor may be a CZT rod 110 as described above, encased in a shielded case 105 (e.g., tungsten) with an aperture 120 open and directed toward a vial or other container containing a radiopharmaceutical sample to expose to the CZT rod 110 along the long dimension of the rod 110 , while shielding the CZT rod 110 from gamma rays incident laterally to the long dimension of the rod 110 , e.g., from directions other than along the longitudinal dimension. According to various aspects, the combination of shielding, aperture and extended length of the CZT detector in the direction of gamma ray emission from a portion of the radiopharmaceutical sample provides a substantial directional “virtual” collimation of the CZT detector's sensitivity to gamma rays incident from a volume of the radiopharmaceutical that is defined by the collimation and the size (e.g., diameter) of the radiopharmaceutical container and the collimation of the acceptance aperture 120 of the detector 100 . According to various aspects, on the basis that the volume of the radiopharmaceutical that is “observable,” or detectable, by the sensor 100 is constant from measurement to measurement, the concentration and activity of the radionuclide can be determined, after calibration. [0036] FIG. 3 shows a conceptual circuit diagram for measuring gamma rays with the detector 100 . According to various aspects, a charge amplifier 130 coupled to the electrodes 115 and 116 amplifies the charge. According to various aspects, a pulse generator 140 converts the sensed charge to a pulse, where the pulse height is proportional to the energy of the gamma ray. A counting circuit 150 may determine the number of pulses as a function of energy. [0037] FIG. 4 is a conceptual illustration of an apparatus 400 for measuring concentration, activity and content volume in a container 415 containing a radionuclide such as F-18 in solution, or a radiopharmaceutical such as F-18 in FDG, using the detector 100 and circuitry of FIGS. 1-3 . According to various aspects, the container 415 may have known dimensions, and therefore is known to be able to hold a specified maximum volume of the radionuclide in a liquid form. In operation, according to various aspects, a first detector 100 - b may be located opposite a bottom face 425 - b of the container 415 . Similarly, according to various aspects, a second detector 100 - t may be located opposite a top face 425 - t of the container, and is similarly configured to detect gamma radiation from the container 415 . According to various aspects, the two detectors 100 - b , 100 - t may be similar or substantially the same. According to various aspects, the two detectors may be identical. Both of the detectors 100 - t and 100 - b is coupled to a differential measurement processing system 450 , shown in greater detail in FIG. 5 . [0038] FIG. 5 is a block diagram describing the differential processing system 450 coupled to the two detectors, 100 - t , 100 - b , according to various aspects. The processing system 450 may include a high voltage supply 452 to provide the bias voltage that operates each of the detectors 100 - t , 100 - b . Charge output from the detectors 100 - t and 100 - b are separately input (optionally) to signal conditioning circuitry 452 if noise filtering or DC offset correction, or other artifact removal is warranted. Alternatively, the signals from the detectors 100 - t , 100 - b may be directly input to a dual channel analog-to-digital converter (ADC) 456 for processing in digital format by a customized chip, such as a flexible programmable gate array (FPGA) 458 . The function of the FPGA 458 will be discussed further below. Output of the FPGA 458 includes at least computed values for the activity sensed by each of the detectors 100 - t , 100 - b and the volume of radionuclide in liquid accumulated in the container 415 . The output of the FPGA 458 may be communicated to a computing platform, such as a personal computer (PC) 460 , or other computing controller for purposes of controlling such processes as filling or emptying the container 415 and identifying parameters associated with the pharmaceutical content for documentation (e.g., date, activity, volume content, labeling, etc.). [0039] The processing system 450 may be distributed across a network to facilitate, for example, efficient use of computing resources to serve a plurality of detectors 100 and containers 415 . The division of the processing system 450 across the network may be selected at any of several points. For example, one or more access nodes (not shown) and network links (not shown) may be placed between the dual channel analog-to-digital converter (ADC) 456 and the FPGA 458 , in which case the FPGA 458 and the computing platform PC 460 may be remotely located across the network. Alternatively, the access nodes and network links may be located between the FPGA 458 and the PC 460 . It should be understood that other network linking arrangements between the detectors 100 and computing and control resources may be configured. The PC 460 may also be a network configured computing resource, which may also be distributed across one or more networks. For example, the computing resource PC 460 may include a server, memory, and other accessories, also located remotely from each other across the one or more networks to provide the operational control of the plurality of detectors 100 coupled to respective containers 415 . [0040] FIG. 6 is a flowchart 600 describing the functions of components of the FPGA 458 . Digitized data from each channel (i.e., top and bottom) of the ADC 456 is input to respective counters for pulse counting (process block 602 ). In conjunction with a clocking signal from a timing source (not shown) the pulse counts per unit of time (e.g., seconds) are converted to respective count rates (process block 604 ). [0041] The count rates are then linearized (in process block 606 for each respective detector 100 - t , 100 - b ). The linearization process may include statistical or calibration-based correction, for example, when the count rate becomes so high that pulses may overlap, an effect referred to as “pile up.” [0042] The measured count rate, as counted by the detector and associated electronics, may become lower than the true count rate at high count rates. This is caused by effects in the bias circuitry, crystal, and the electronics. In the bias circuitry and crystal, a high photon flux can cause a shift in the spectral response (as a decreased photopeak to background ratio) which can cause undercounting. Also, the pulse width (governed by the crystal and preamplifier characteristics) along with the pulse counting electronics can have an impact on linearity. At high count rates, pulses can pile up and double or triple pulses may be combined and counted as one instead of two or three separate pulses respectively. This is exacerbated when the pulse width is increased or the counting electronics is too slow to count fast pulse rates (long retrigger times, etc.). [0043] To linearize the count rate, a nonlinearity calibration is performed, along with implementing a look-up table or nonlinearity correction equation. To perform calibration, a high activity sample (e.g., having a maximum expected activity) is placed in front of each sensor and allowed to decay. Data is then collected over several half-lives until the count rate is low (i.e., in the linear range where no pulse pile up occurs). Curve fitting is then performed (e.g., polynomial, Lambert-W, etc.) to describe the relationship between true count rate and the measured count rate. Once established, the curve for each sensor (detector and electronics) can be used in a look-up table or equation-based correction to linearize measurements made. [0044] Accordingly, a correction may be applied on a calibration basis to correct for an undercounting of pulses due to pulse overlap. If a background count has been detected (such as, for example, before the container is filled), a command may be issued for each detector rate to read the background rate (in process blocks 608 - t , 608 - b , whether from a look-up table, a previous reading from the detectors prior to filling the container, etc.). The background rates are subtracted (in process blocks 610 - t and 610 - b ) from the respective linearized count rates. [0045] The ratio of the resulting “adjusted” counting rates is computed (in process block 612 ) and the logarithm of the ratio is computed (in process block 613 ) which, as it happens is approximately linear in proportion to the fill level of the container 415 . In one embodiment, the log ratio measurement may be referred to a lookup table to compute the fill volume of the container (as in process block 614 ). The fill volume depends on a known value of the shape, cross-section and height of the container 415 . The adjusted count rate for each detector is compared with the computed volume to determine the lookup activity (in process blocks 616 - t and 616 - b ) for each respective detector 100 - t , 100 - b . The outputs to the PC 460 include the top activity level, bottom activity level, and container volume. [0046] FIG. 7 is a plot of gamma ray activity in counts per second (cps) of the top detector 425 - t and the bottom detector 425 - b of the apparatus in FIG. 3 as a container between the two detectors is filled, according to various aspects. Because the two detectors 425 - t and 425 - b may be placed opposite each other, they both interrogate substantially a same volume element. When the container 430 is nearly empty, both detectors register substantially zero counts, apart from background counts, however the ratio asymptotically approaches zero, and the logarithmic ratio becomes large negative. When the container 430 is full, both detectors 425 - t , 425 - b interrogate substantially the same volume, and therefore register equal counts. Therefore, the ratio between the counts of both detectors 425 - t and 425 - b is equal to one, and the logarithmic value of the ratio is thus 0. According to various aspects, FIG. 8 is a logarithmic plot of the ratio of counts of the top detector 425 - t to the counts of the bottom detector 425 - b as a function of fill level in the container 430 of the apparatus 400 . For intermediate levels of fill, the log ratio is approximately linear, and the linearized logarithmic measure of the count ratio may be used to determine the fill volume of the entire container, because it may be assumed that the dimensions and shape of the container 430 is defined (e.g., a cylinder of known constant cross-section area and height). With the fill volume and activity thus determined, the concentration of the radionuclide can be determined. [0047] According to various aspects, FIG. 9 presents an exemplary system diagram of various hardware components and other features, for use in networking the apparatus for measuring concentration, activity and content volume, in accordance with an aspect of the present invention. Computer system 900 may include a communications interface 924 . Communications interface 924 allows software and data to be transferred between computer system 900 and external devices. Examples of communications interface 924 may include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. Software and data transferred via communications interface 924 are in the form of signals 928 , which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface 924 . These signals 928 are provided to communications interface 924 via a communications path (e.g., channel) 926 . This path 926 carries signals 928 and may be implemented using wire or cable, fiber optics, a telephone line, a cellular link, a radio frequency (RF) link and/or other communications channels. In this document, the terms “computer program medium” and “computer usable medium” are used to refer generally to media such as a removable storage drive 980 , a hard disk installed in hard disk drive 970 , and signals 928 . These computer program products provide software to the computer system 900 . The invention is directed to such computer program products. [0048] Computer programs (also referred to as computer control logic) are stored in main memory 908 and/or secondary memory 910 . Computer programs may also be received via communications interface 924 . Such computer programs, when executed, enable the computer system 900 to perform the features of the present invention, as discussed herein. In particular, the computer programs, when executed, enable the processor 910 to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system 900 . [0049] In an aspect where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 900 using removable storage drive 914 , hard drive 912 , or communications interface 920 . The control logic (software), when executed by the processor 904 , causes the processor 904 to perform the functions of the invention as described herein. In another aspect, the invention is implemented primarily in hardware using, for example, hardware components, such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). [0050] In yet another aspect, the invention is implemented using a combination of both hardware and software. [0051] FIG. 10 is a block diagram of various exemplary system components for providing communications with and between various components of the apparatus for measuring concentration, activity and content volume, in accordance with an aspect of the present invention. FIG. 10 shows a communication system 1000 usable in accordance with the present invention. The communication system 1000 includes one or more accessors 1060 , 1062 (also referred to interchangeably herein as one or more “users”) and one or more terminals 1042 , 1066 . In one aspect, data for use in accordance with the present invention is, for example, input and/or accessed by accessors 1060 , 1064 via terminals 1042 , 1066 , such as personal computers (PCs), minicomputers, mainframe computers, microcomputers, telephonic devices, or wireless devices, such as personal digital assistants (“PDAs”) or a hand-held wireless devices coupled to a server 1043 , such as a PC, minicomputer, mainframe computer, microcomputer, or other device having a processor and a repository for data and/or connection to a repository for data, via, for example, a network 1044 , such as the Internet or an intranet, and couplings 1045 , 1046 , 1064 . The couplings 1045 , 1046 , 1064 include, for example, wired, wireless, or fiber optic links. In another aspect, the method and system of the present invention operate in a stand-alone environment, such as on a single terminal. [0052] The previous description is provided to enable any person skilled in the art to fully understand the full scope of the disclosure. Modifications to the various configurations disclosed herein will be readily apparent to those skilled in the art. Thus, the claims are not intended to be limited to the various aspects of the disclosure described herein, but is to be accorded the full scope consistent with the language of claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A claim that recites at least one of a combination of elements (e.g., “at least one of A, B, or C”) refers to one or more of the recited elements (e.g., A, or B, or C, or any combination thereof). All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” [0053] While aspects of this invention have been described in conjunction with the example features outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example aspects of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and thereof. Therefore, aspects of the invention are intended to embrace all known or later-developed alternatives, modifications, variations, improvements, and/or substantial equivalents.

A gamma ray detector includes a gamma ray detecting rod elongated along a longitudinal axis, wherein gamma ray detection is enhanced along the longitudinal axis, and a gamma ray shield encapsulating the rod, the shield having an aperture at an end of the detecting rod along the longitudinal axis to admit gamma rays substantially parallel to the longitudinal axis of the elongated detecting rod, wherein gamma ray detection is enhanced along the longitudinal axis and aperture to substantially collimate the sensitivity of the gamma ray detector along the combined aperture and longitudinal axis of the detecting rod.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation application of International Application PCT/JP2012/058738 filed on Mar. 30, 2012 and designated the U.S., the entire contents of which are incorporated herein by reference. FIELD [0002] The disclosures herein generally relate to a wireless communication apparatus. BACKGROUND [0003] A wireless apparatus built in a cellular phone or the like includes a wireless unit (also called a “radio frequency (RF) unit”) and a baseband processing apparatus. The interface between the wireless unit and the baseband processing apparatus is configured with lines including an analog signal line and a digital or analog control line. [0004] In recent years, an RFIC (RF Integrated Circuit) included in a wireless unit can be made from a CMOS (Complementary Metal-Oxide Semiconductor) circuit. The RFIC can include an analog-digital converter (ADC) and a digital-analog converter (DAC). [0005] Following this, an interface has been standardized for digital signal connection between an RFIC and a digital IC for baseband processing. The interface standardized for digital signal connection between an RFIC and a digital IC includes “DigRF”. [0006] Version 3 of the DigRF standard (DigRF v3) is for an LVDS transmission frequency of about 300 MHz, and a DigRF packet does not include an error determination bit. Therefore, according to Version 3 of the DigRF standard, if an error occurs in a DigRF packet, retransmission control is not executed. [0007] In contrast to DigRF v3, Version 4 of the DigRF standard (DigRF v4) is for an LVDS transmission frequency of about 1 GHz, and an error determination bit is provided in a DigRF packet. Therefore, in DigRF v4, error detection is executed for data between an RFIC and a baseband processing apparatus, and if an error is detected, retransmission control is executed for the data (see, for example, Patent Document 1). For example, when data is transmitted from an RFIC to a baseband processing apparatus, the baseband processing apparatus executes error detection in the data from the RFIC. If detecting an error in the data from the RFIC, the baseband processing apparatus makes a retransmission-request of the data to the RFIC. In response to receiving the retransmission-request of the data, the RFIC transmits the data again to the baseband processing apparatus. RELATED-ART DOCUMENTS Patent Documents [0000] [Patent Document 1] Japanese Laid-open Patent Publication No. 2010-268395 Non-Patent Document [0000] [Non-Patent Document 1] 3GPP TS25.211 V11.0.0, “5.3.2 Dedicated downlink physical channels”, 2011-12 [0010] When a retransmission process of data is executed in data transmission from a wireless unit to a baseband processing apparatus as described above, timing for the baseband processing apparatus to start a baseband process is delayed for time required for the retransmission process. Consequently, a process in the baseband processing apparatus cannot be completed within the time specified in the 3GPP (3rd Generation Partnership Project) specification, and, for example, there are cases where a delay occurs for timing of transmission power control. [0011] The 3GPP specification specifies that a user terminal (also called “user equipment (UE)”) receives a wireless signal, for example, a dedicated physical channel (DPCH) from a base station (see, for example, Non-Patent Document 1). It is specified that such a user terminal demodulates a pilot symbol included in the DPCH, and calculates an SIR (Signal-to-Interference Ratio). It is also specified that such a user terminal maps information about power control based on reception power, into a dedicated physical control channel (DPCCH). [0012] For a downlink DPCH, a delay offset of 296 chips at maximum is generated during a soft handover (SHO). Therefore, considering the maximum delay of the DPCH, the user terminal has to transmit an uplink DPCCH having the information about power control based on the received power mapped, at a timing of 216 chips after the reception of the pilot symbol. [0013] However, when a retransmission process of data is executed at the DigRF interface between the wireless unit and the baseband processing apparatus in the wireless terminal, the baseband processing apparatus waits for the retransmission of a DigRF packet. Therefore, if the user terminal cannot transmit the uplink DPCCH having the information about power control based on the received power mapped, at a timing of 216 chips after the reception of the pilot symbol, the user terminal is forced to wait for a next transmission timing to transmit the uplink DPCCH having the information about power control based on the received power mapped. [0014] Therefore, if a retransmission process is executed for data at a connection interface between elements in a wireless terminal, and if a required process is not completed within a process time specified in the 3GPP specification, transmission power control may be delayed in the downlink direction. SUMMARY [0015] According to at least an embodiment of the present invention, a wireless apparatus includes a wireless unit to convert a wireless signal received by an antenna into a baseband signal; and a baseband processing apparatus to receive a packet corresponding to the baseband signal via a communication line connected with the wireless unit, to detect an error in a transmission process of the packet via the communication line, to obtain the baseband signal based on packets other than the packet in which the error is detected, to generate transmission power information used for downlink transmission power control based on the obtained baseband signal, to transmit the baseband signal having the generated transmission power information reflected to the wireless unit via the communication line, and to have the wireless unit execute wireless transmission of a wireless signal corresponding to the baseband signal having the transmission power information reflected. [0016] The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed. BRIEF DESCRIPTION OF DRAWINGS [0017] FIG. 1 illustrates a wireless apparatus according to an embodiment of the present invention; [0018] FIG. 2A is a functional block diagram of a wireless apparatus according to an embodiment of the present invention; [0019] FIG. 2B is a functional block diagram of a wireless apparatus according to an embodiment of the present invention; [0020] FIG. 3 illustrates an example of a DigRF packet; [0021] FIG. 4 illustrates an example of a process for specifying a range of pilot symbols used for calculating a transmission TPC bit; [0022] FIG. 5 illustrates an example of a process for calculating an SIR; [0023] FIG. 6 illustrates an example of a process for calculating an SIR; [0024] FIG. 7 is a timing chart of transmission power control according to an embodiment of the present invention; [0025] FIG. 8 is a flowchart of a process for calculating an SIR according to an embodiment of the present invention; [0026] FIG. 9A is a flowchart of operations of a wireless apparatus according to an embodiment of the present invention; [0027] FIG. 9B is a flowchart of operations of a wireless apparatus according to an embodiment of the present invention; and [0028] FIG. 10 is a timing chart of an example of transmission power control. DESCRIPTION OF EMBODIMENTS [0029] In the following, embodiments of the present invention will be described with reference to the drawings. Note that elements having the same functions across the drawings are assigned the same numerical codes, and their description may not be repeated. [0030] <Wireless Apparatus 100 > [0031] FIG. 1 illustrates a wireless apparatus 100 according to an embodiment of the present invention. FIG. 1 mainly illustrates an example of a hardware configuration. The wireless apparatus 100 is built in a user terminal, for example. [0032] The user terminal may be any terminal appropriate for wireless communication, which includes a cellular phone, an information terminal, a personal digital assistant, a portable personal computer, and a smart phone, but it is not limited to these. The wireless apparatus 100 may also be built in an image forming apparatus or a household electric appliance. [0033] In the present embodiment, the wireless apparatus 100 is described for a case where wireless access is executed in accordance with WCDMA (Wideband Code Division Multiple Access), but it may be executed in accordance with another method such as LTE (Long Term Evolution) or LTE-Advanced. [0034] In the present embodiment, the wireless apparatus 100 is described for a case where the SIR is used as reception quality, but other indicators may be used. [0035] The wireless apparatus 100 includes an RFIC 200 and a baseband processing apparatus 300 . The RFIC 200 and the baseband processing apparatus 300 may be implemented in semiconductor integrated circuits, respectively. The baseband processing apparatus 300 can be manufactured as a semiconductor integrated circuit by converting a program written in a circuit design language into circuit information by a compiler. [0036] The RFIC 200 receives a wireless signal from another wireless apparatus, and inputs the wireless signal into the baseband processing apparatus 300 . Also, the RFIC 200 converts the signal from the baseband processing apparatus 300 into a wireless signal, and transmits the wireless signal to the other wireless apparatus. The other wireless apparatus includes a wireless base station. [0037] The baseband processing apparatus 300 is connected with the RFIC 200 . For example, the baseband processing apparatus 300 and the RFIC 200 are connected with each other by an interface using digital signal based connection. The interface includes “DigRF”. The baseband processing apparatus 300 executes a baseband process for the digital signal from the RFIC 200 . Also, the baseband processing apparatus 300 inputs the digital signal to be transmitted, into the RFIC 200 . [0038] The baseband processing apparatus 300 includes a DSP (Digital Signal Processor) 3002 , a CPU (Central Processing Unit) 3004 , a memory 3006 , and hardware 3008 . [0039] The DSP 3002 executes baseband signal processing based on instructions from the CPU 3004 . The DSP 3002 generates data to be transmitted to the other wireless apparatus based on instructions from the CPU 3004 , and executes control for inputting the data into the RFIC 200 . [0040] The CPU 3004 is connected with the DSP 3002 . The CPU 3004 has the DSP 3002 execute digital signal processing based on software such as built-in firmware and a program stored in the memory 3006 . [0041] The memory 3006 is connected with the CPU 3004 . The memory 3006 stores the program executed by the DSP 3002 and the CPU 3004 . [0042] The hardware 3008 is connected with the DSP 3002 . The hardware 3008 executes a modulation process, an encoding process, a demodulation process, and various calculations. [0043] FIGS. 2A-2B are functional block diagrams of the wireless apparatus 100 according to the present embodiment. [0044] The wireless apparatus 100 includes the RFIC 200 and the baseband processing apparatus 300 . FIG. 2A mainly illustrates the RFIC 200 in the present embodiment. FIG. 2B mainly illustrates the baseband processing apparatus 300 in the present embodiment. [0045] The RFIC 200 executes reception/transmission of a wireless signal with the other wireless apparatus via an antenna. [0046] The baseband processing apparatus 300 is connected with the RFIC 200 via digital communication paths (RxPath and TxPath). The baseband processing apparatus 300 executes a baseband process for a DigRF-packeted signal from the RFIC 200 . Also, the baseband processing apparatus 300 inputs DigRF-packeted data into the RFIC 200 . [0047] <RFIC 200 > [0048] The RFIC 200 includes an RxADC 202 , a TxDAC 204 , and a DigRF control unit 206 . The DigRF control unit 206 includes a retransmission control unit 208 , a retransmission control unit 210 , an LVDS (Low Voltage Differential Signaling) driver 212 , and an LVDS receiver 214 . [0049] The RxADC 202 receives a wireless signal from the other wireless apparatus via the antenna, and converts the wireless signal into a digital signal. The RxADC 202 inputs the digital signal into the retransmission control unit 208 . Note that other circuit elements (not illustrated) may be inserted between the antenna and the RxADC 202 , and between the RxADC 202 and the DigRF control unit 206 . [0050] The retransmission control unit 208 is connected with the RxADC 202 . The retransmission control unit 208 executes buffering for the digital signal from the RxADC 202 . The retransmission control unit 208 inputs the digital signal from the RxADC 202 to the LVDS driver 212 . Also, if receiving a retransmission-request signal as input from the retransmission control unit 210 , the retransmission control unit 208 inputs a digital signal corresponding to the retransmission-request among the buffered digital signals, into the LVDS driver 212 . [0051] The LVDS driver 212 is connected with the retransmission control unit 208 . The LVDS driver 212 generates a DigRF packet of the digital signal from the retransmission control unit 208 . The LVDS driver 212 executes a LVDS drive process for the DigRF-packeted signal (referred to as a “DigRF packet” below). Namely, the LVDS driver 212 outputs the DigRF packet to the baseband processing apparatus 300 via the RxPath. [0052] The LVDS receiver 214 receives a transmission signal or a retransmission-request signal from the baseband processing apparatus 300 , and inputs it into the retransmission control unit 210 . [0053] The retransmission control unit 210 is connected with the LVDS receiver 214 and the retransmission control unit 208 . The retransmission control unit 210 inputs a transmission signal from the LVDS receiver 214 into the TxDAC 204 . Also, the retransmission control unit 210 inputs a retransmission-request signal from the LVDS receiver 214 into the retransmission control unit 208 . [0054] The TxDAC 204 is connected with the retransmission control unit 210 . The TxDAC 204 converts the transmission signal from the retransmission control unit 210 into an analog signal. The TxDAC 204 converts the transmission signal having been converted into the analog signal, into a wireless signal, and transmits the wireless signal to the other wireless apparatus via the antenna. Note that other circuit elements (not illustrated) may be inserted between the antenna and the TxDAC 204 , and between the TxDAC 204 and the DigRF control unit 206 . [0055] <Baseband Processor 300 > [0056] The baseband processing apparatus 300 includes a DigRF control unit 302 , a pilot symbol range specification unit 316 , a despreading unit 318 , a CPICH demodulation unit 320 , and an SIR calculation unit 322 . [0057] The baseband processing apparatus 300 also includes a DPCH demodulation unit 324 , a data decoding unit 326 , a TFCI (Transport Format Combination Indicator) bit determination unit 328 , and a reception TPC bit determination unit 330 . [0058] The baseband processing apparatus 300 also includes an SIR calculation unit 332 , a transmission TPC bit determination unit 334 , an encoding unit 336 , a modulation unit 338 , a transmission power calculation unit 340 , and a transmission unit 342 . [0059] The DigRF control unit 302 includes an LVDS receiver 304 , a retransmission control unit 306 , an error symbol part determination unit 308 , a buffer 310 , an LVDS driver 312 , and a retransmission control unit 314 . [0060] The error symbol part determination unit 308 , the pilot symbol range specification unit 316 , the TFCI bit determination unit 328 , and the reception TPC bit determination unit 330 are executed by the CPU 3004 based on the program stored in the memory 3006 . Alternatively, the error symbol part determination unit 308 , the pilot symbol range specification unit 316 , the TFCI bit determination unit 328 , and the reception TPC bit determination unit 330 may be executed by the CPU 3004 based on the firmware stored in an internal memory of the CPU 3004 . [0061] The retransmission control unit 306 and 314 , the despreading unit 318 , and the transmission unit 342 are executed by the DSP 3002 . [0062] The LVDS receiver 304 , the buffer 310 , the LVDS driver 312 , the CPICH demodulation unit 320 , the SIR calculation unit 322 , the DPCH demodulation unit 324 , and the data decoding unit 326 are executed by the hardware 3008 . Also, the SIR calculation unit 332 , the transmission TPC bit determination unit 334 , the encoding unit 336 , the modulation unit 338 , and the transmission power calculation unit 340 are executed by the hardware 3008 . [0063] The LVDS receiver 304 is connected with the LVDS driver 212 . The LVDS receiver 304 receives a DigRF packet from the RFIC 200 via the RxPath. The LVDS receiver 304 inputs the DigRF packet from the RFIC 200 into the retransmission control unit 306 . [0064] The retransmission control unit 306 is connected with the LVDS receiver 304 . The retransmission control unit 306 detects a data error in the DigRF packet from the LVDS receiver 304 . [0065] FIG. 3 illustrates an example of a DigRF packet. [0066] The DigRF packet includes a header, a payload, and an error detection code. [0067] The header includes information representing a data type, information representing a frame number, and information representing a frame length. [0068] The payload includes one or more symbols. In the example illustrated in FIG. 3 , the payload includes 16 symbols. In the example illustrated in FIG. 3 , the payload includes eight chips denoted as chip # 1 to chip # 8 . Namely, one chip includes two symbols. One chip includes two pieces of I data (I channel (ch)) and two pieces of Q data (Q channel (ch)). An I ch and a Q ch are represented with eight bits, respectively. One packet includes eight chips, and one chip includes two I channels and two Q channels. [0069] The error detection code is used for determining whether an error is included in data included in the payload. The error detection code includes, for example, a cyclic redundancy check (CRC) code. [0070] The retransmission control unit 306 makes a retransmission-request to the retransmission control unit 314 if an error is detected in data included in a DigRF packet. If an error is detected in data included in a DigRF packet, the retransmission control unit 306 inputs information representing the DigRF packet in which the error is detected (referred to as “error DigRF packet information” below) into the error symbol part determination unit 308 . Specifically, if an error is detected in data included in a DigRF packet, the retransmission control unit 306 inputs the information representing the frame number included in the header of the DigRF packet in which the error is detected, into the error symbol part determination unit 308 . [0071] Also, the retransmission control unit 306 stores the DigRF packet in the buffer 310 , and inputs the DigRF packet into the SIR calculation unit 332 . [0072] Also, if the DigRF packet from the LVDS receiver 304 is a retransmission packet, the retransmission control unit 306 replaces a DigRF packet stored in the buffer 310 with the retransmission DigRF packet. The retransmission control unit 306 executes control for inputting the DigRF packet stored in the buffer 310 into the despreading unit 318 . [0073] The retransmission control unit 314 is connected with the retransmission control unit 306 . The retransmission control unit 314 inputs a transmission signal from the transmission unit 342 to the LVDS driver 312 . Also, in response to a retransmission-request from the retransmission control unit 306 , the retransmission control unit 314 inputs the retransmission-request signal into the LVDS driver 312 . [0074] The LVDS driver 312 is connected with the retransmission control unit 314 and the LVDS receiver 214 . The LVDS driver 312 generates a DigRF packet of the retransmission-request signal from the retransmission control unit 314 . The LVDS driver 312 inputs the DigRF-packeted retransmission-request signal into the RFIC 200 . [0075] Also, the LVDS driver 312 generates a DigRF packet of the transmission signal from the retransmission control unit 314 . The LVDS driver 312 inputs the DigRF-packeted transmission signal into the RFIC 200 . [0076] The despreading unit 318 is connected with the buffer 310 . The despreading unit 318 applies despreading to the DigRF packet from the buffer 310 . The despreading unit 318 separates the DigRF packet having despreading applied into channels. Specifically, the despreading unit 318 separates the DigRF packet having despreading applied into a common pilot channel (CPICH) and a dedicated physical channel (DPCH). The despreading unit 318 inputs the CPICH into the CPICH demodulation unit 320 . Also, the despreading unit 318 inputs the DPCH into the DPCH demodulation unit 320 . Moreover, the despreading unit 318 inputs a transmission timing signal into the transmission unit 342 . [0077] The CPICH demodulation unit 320 is connected with the despreading unit 318 . The CPICH demodulation unit 320 demodulates the CPICH from the despreading unit 318 . The CPICH demodulation unit 320 inputs the demodulated CPICH into the SIR calculation unit 322 . [0078] The SIR calculation unit 322 is connected with the CPICH demodulation unit 320 . The SIR calculation unit 322 calculates an SIR based on the demodulated CPICH from the CPICH demodulation unit 320 . [0079] The DPCH demodulation unit 324 is connected with the despreading unit 318 . The DPCH demodulation unit 324 demodulates the DPCH from the despreading unit 318 . The DPCH demodulation unit 324 inputs the demodulated DPCH into the data decoding unit 326 , the TFCI bit determination unit 328 , and the reception TPC bit determination unit 330 . [0080] The data decoding unit 326 is connected with the DPCH demodulation unit 324 . The data decoding unit 326 decodes the demodulated DPCH from the DPCH demodulation unit 324 . [0081] The TFCI bit determination unit 328 is connected with the DPCH demodulation unit 324 . The TFCI bit determination unit 328 determines a TFCI bit based on the demodulated DPCH from the DPCH demodulation unit 324 . [0082] The reception TPC bit determination unit 330 is connected with the DPCH demodulation unit 324 . The reception TPC bit determination unit 330 determines whether the TPC bit included in the demodulated DPCH from the DPCH demodulation unit 324 indicates an up or a down. The reception TPC bit determination unit 330 inputs information representing whether the TPC bit included in the demodulated DPCH from the DPCH demodulation unit 324 indicates an up or a down (referred to as “reception TPC bit information” below), into the transmission power calculation unit 340 . [0083] The transmission power calculation unit 340 is connected with the reception TPC bit determination unit 330 . The transmission power calculation unit 340 calculates transmission power of the DPCCH and DPDCH based on the reception TPC bit information from the reception TPC bit determination unit 330 . The transmission power calculation unit 340 inputs information representing the calculation result of the transmission power of the DPCCH and DPDCH, into the transmission unit 342 . [0084] The error symbol part determination unit 308 is connected with the retransmission control unit 306 . The error symbol part determination unit 308 determines an error symbol location based on the error DigRF packet information from the retransmission control unit 306 . The error symbol part determination unit 308 inputs information representing the error symbol location (referred to as “error symbol information” below) into the pilot symbol range specification unit 316 . [0085] The pilot symbol range specification unit 316 is connected with the error symbol part determination unit 308 . The pilot symbol range specification unit 31 specifies a range of pilot symbols used for calculating a TPC bit to be transmitted to the other wireless apparatus based on the error symbol information from the error symbol part determination unit 308 . [0086] The pilot symbol range specification unit 316 inputs information representing the range of pilot symbols used for calculating a TPC bit to be transmitted to the other wireless apparatus (referred to as “pilot symbol range information” below) into the SIR calculation unit 332 . [0087] FIG. 4 illustrates a process executed by the pilot symbol range specification unit 316 . FIG. 4 illustrates a table including multiple DigRF packets where each record stores whether an error is detected in each of the packets. The table is used for obtaining a range of pilot symbols used for calculating a TPC bit to be transmitted to the other wireless apparatus (referred to as a “transmission TPC bit” below). [0088] The pilot symbol range specification unit 316 in the present embodiment provides the table where the address of a DigRF packet is associated with the error symbol information and the pilot symbol range information. [0089] The pilot symbol range specification unit 316 specifies the pilot symbol range with multiple DigRF packets as a unit. The pilot symbol range specification unit 316 specifies pilot symbols included in DigRF packets other than the DigRF packet that includes the error symbol specified by the error symbol information, as the pilot symbol range information. [0090] The pilot symbol range specification unit 316 in the embodiment specifies the pilot symbol range by the unit of 32 DigRF packets. The pilot symbol range specification unit 316 identifies the DigRF packet that includes an error symbol based on the error symbol information from the error symbol part determination unit 308 . In the example illustrated in FIG. 4 , the pilot symbol range specification unit 316 identifies a DigRF packet whose DigRF packet address is “18”. The pilot symbol range specification unit 316 identifies DigRF packets other than the packet whose DigRF packet address is “18”. The pilot symbol range specification unit 316 specifies DigRF packets other than the packet whose DigRF packet address is “18”, as the pilot symbol range information. Specifically, the pilot symbol range specification unit 316 specifies the DigRF packets whose DigRF packet addresses are 0-17 and 19-31, as the pilot symbol range information. [0091] After having specified the pilot symbol range information, the pilot symbol range specification unit 316 executes the same process for the next 32 DigRF packets. [0092] The SIR calculation unit 332 is connected with the pilot symbol range specification unit 316 and the retransmission control unit 306 . The SIR calculation unit 332 calculates an SIR based on the DigRF packet from the retransmission control unit 306 and the pilot symbol range information from the pilot symbol range specification unit 316 . Specifically, the SIR calculation unit 332 calculates likelihood for eight chips included in the DigRF packet by taking a quarter chip as one sample. The SIR calculation unit 332 calculates the likelihood for pilot symbols specified by the pilot symbol range information. The SIR calculation unit 332 sums the calculation results of the likelihood, and outputs the average value as the SIR. [0093] <Case where an Error is Not Detected in DigRF Packet> [0094] FIG. 5 illustrates an SIR calculation process when an error is not detected in a DigRF packet. If an error is not detected in the DigRF packet, the retransmission control unit 306 does not input error DigRF packet information into the error symbol part determination unit 308 . Alternatively, if an error is not detected in the DigRF packet, the retransmission control unit 306 may input information representing that an error is not detected, into the error symbol part determination unit 308 . [0095] Moreover, the error symbol part determination unit 308 does not input error symbol information into the pilot symbol range specification unit 316 . Alternatively, the error symbol part determination unit 308 may input information representing that an error is not detected, into the pilot symbol range specification unit 316 . Therefore, the pilot symbol range specification unit 316 does not input pilot symbol range information into the SIR calculation unit 332 . Alternatively, the pilot symbol range specification unit 316 may input information specifying the entire range as the pilot symbol range information, into the SIR calculation unit 332 . In this case, the SIR calculation unit 332 calculates the SIR based on the DigRF packet from the retransmission control unit 306 . Specifically, the SIR calculation unit 332 calculates likelihood for 256 chips included in the DigRF packet by taking a quarter chip as one sample. The SIR calculation unit 332 sums the calculation results of the likelihood, and takes the average to calculate the SIR used for calculating a transmission TPC bit. [0096] <Case where an Error is Detected in DigRF Packet> [0097] FIG. 6 illustrates an SIR calculation process when an error is detected in a DigRF packet. If an error is detected in the DigRF packet, the retransmission control unit 306 inputs the error DigRF packet information into the error symbol part determination unit 308 . [0098] The error symbol part determination unit 308 determines an error symbol location based on the error DigRF packet information from the retransmission control unit 306 . The error symbol part determination unit 308 inputs the error symbol information into the pilot symbol range specification unit 316 . [0099] The pilot symbol range specification unit 31 specifies a range of pilot symbols used for calculating a transmission TPC bit based on the error symbol information from the error symbol part determination unit 308 . Specifically, as illustrated in FIG. 6 , the pilot symbol range specification unit 316 identifies a DigRF packet that includes a symbol designated by the error symbol location specified in the error symbol information. The pilot symbol range specification unit 316 sets the range of the pilot symbols included in DigRF packets other than the identified DigRF packet, as the range of the pilot symbols used for calculating a transmission TPC bit. The pilot symbol range specification unit 316 inputs the pilot symbol range information into the SIR calculation unit 332 . [0100] The SIR calculation unit 332 calculates an SIR based on the DigRF packet from the retransmission control unit 306 and the pilot symbol range information from the pilot symbol range specification unit 316 . Specifically, the SIR calculation unit 332 calculates likelihood for eight chips included in the DigRF packet by taking a quarter chip as one sample. The SIR calculation unit 332 calculates the likelihood for the pilot symbols specified by the pilot symbol range information. For example, if an error is detected in the DigRF packet, the SIR calculation unit 332 calculates the likelihood for 248 chips, which is obtained by subtracting eight chips from 256 chips included in 32 DigRF packets, by taking a quarter chip as one sample. The SIR calculation unit 332 sums the calculation results of the likelihood, and outputs the average value as the SIR. If there are a small number of DigRF packets in which errors are detected, it is assumed the influence on the SIR is tolerable even if the likelihood is calculated based on DigRF packets other than the DigRF packet. [0101] The transmission TPC bit determination unit 334 is connected with the SIR calculation unit 332 . The transmission TPC bit determination unit 334 calculates a transmission TPC bit based on the SIR from the SIR calculation unit 332 . For example, the transmission TPC bit determination unit 334 may calculate a transmission TPC bit so that the SIR from the SIR calculation unit 332 becomes a predetermined SIR. The transmission TPC bit determination unit 334 inputs the transmission TPC bit into the encoding unit 336 . [0102] The encoding unit 336 is connected with the transmission TPC bit determination unit 334 . The encoding unit 336 encodes the transmission TPC bit from the transmission TPC bit determination unit 334 . The encoding unit 336 inputs the encoded transmission TPC bit (referred to as the “encoded transmission TPC bit” below) into the modulation unit 338 . [0103] The modulation unit 338 is connected with the encoding unit 336 . The modulation unit 338 modulates the encoded transmission TPC bit from the encoding unit 336 . The modulation unit 338 inputs the modulated encoded transmission TPC bit into the transmission unit 342 . [0104] The transmission unit 342 is connected with the modulation unit 338 and the transmission power calculation unit 340 . The transmission unit 342 executes a process for transmitting the modulated encoded transmission TPC bit from the modulation unit 338 based on information about a calculation result of transmission power from the transmission power calculation unit 340 . When executing the process for transmitting the encoded transmission TPC bit, the transmission unit 342 controls transmission timing following a transmission timing signal from the despreading unit 318 . [0105] <Transmission Power Control Process> [0106] FIG. 7 is a timing chart of a transmission power control process in the wireless apparatus 100 according to the present embodiment. In FIG. 7 , a state is illustrated as an example where a delay offset of a maximum of 296 chips is generated by a soft handover (SHO). [0107] The 3GPP specifies that an SIR is calculated after receiving a downlink DPCH, by demodulating a pilot symbol that is mapped in the tenth symbol of the DPCH. [0108] The 3GPP also specifies that a transmission TPC bit is mapped in a TPC included in an uplink DPCCH that comes at timing of 512 chips after the reception of the pilot symbol. [0109] The downlink DPCH generates the delay offset of the maximum of 296 chips during the soft handover. Considering the delay offset of the DPCH, the uplink DPCCH having the transmission TPC bit mapped needs to be transmitted at a timing of 216 chips (512 chips−296 chips) after the reception of the pilot symbol. [0110] The RFIC 200 receives the downlink DPCH 700 , and generates a DigRF packet. The RFIC 200 transmits the DigRF packet to the baseband processing apparatus 300 ( 702 ). Note that if an error is detected in the DigRF packet, the baseband processing apparatus 300 executes a retransmission control process of the data. However, the baseband processing apparatus 300 calculates a transmission TPC bit without waiting for the arrival of the retransmission data by the retransmission control. [0111] The baseband processing apparatus 300 determines the error symbol location of the DigRF packet ( 704 ). Next, the baseband processing apparatus 300 calculates the transmission TPC bit based on chips included in DigRF packets other than the DigRF packet including the error symbol, and executes the process for transmitting the transmission TPC bit ( 706 ). Specifically, the baseband processing apparatus 300 maps the transmission TPC bit into the uplink DPCCH. [0112] The baseband processing apparatus 300 transmits the uplink DPCCH having the transmission TPC bit mapped to the RFIC 200 ( 708 ). [0113] The RFIC 200 transmits the uplink DPCCH from the baseband processing apparatus 300 . [0114] By calculating the transmission TPC bit without waiting for the arrival of the retransmission data by the retransmission control, the wireless apparatus 100 can transmit the uplink DPCCH having the transmission TPC bit mapped, at a timing of 216 chips after the reception of the pilot. Therefore, even if an error is detected in the packet from the RFIC 200 , the baseband processing apparatus 300 in the wireless apparatus 100 can transmit the uplink DPCCH having the transmission TPC bit mapped, at the timing of 216 chips after the reception of the pilot. Therefore, a delay time can be shortened for transmission power control for the wireless apparatus 100 by the other wireless apparatus, especially by a base station. [0115] <SIR Calculation Process> [0116] FIG. 8 is a flowchart of a process for calculating an SIR according to the present embodiment. FIG. 8 mainly illustrates a process executed by the error symbol part determination unit 308 , the pilot symbol range specification unit 316 , and the SIR calculation unit 332 . [0117] At Step S 804 , the SIR calculation unit 332 receives a DigRF packet from the retransmission control unit 306 . [0118] At Step S 806 , the SIR calculation unit 332 counts the number of DigRF packets from the retransmission control unit 306 . [0119] At Step S 808 , the error symbol part determination unit 308 determines whether an error is detected in the DigRF packet based on error DigRF packet information from the retransmission control unit 306 . [0120] At Step S 810 , if it is determined at Step S 808 that an error is detected in the DigRF packet, the pilot symbol range specification unit 316 counts the number of DigRF packets in which errors are detected. Specifically, the pilot symbol range specification unit 316 sets “1” to a part corresponding to the DigRF packet in which an error is detected in the table illustrated in FIG. 4 for counting the number of DigRF packets in which errors are detected. [0121] At Step S 812 , if it is determined at Step S 808 that an error is not detected in the DigRF packet, the following steps are executed. Namely, the pilot symbol range specification unit 316 sets “0” to the part corresponding to the DigRF packet in which an error is not detected in the table illustrated in FIG. 4 . After that, the pilot symbol range specification unit 316 determines whether the number of DigRF packets reach 32. The pilot symbol range specification unit 316 may determine whether the number of chips reach 256 . [0122] The following is also executed in Step S 812 after setting “1” to the part corresponding to the DigRF packet in which the error is detected. Namely, the pilot symbol range specification unit 316 determines whether the number of DigRF packets reach 32. The pilot symbol range specification unit 316 may determine whether the number of chips reach 256. [0123] At Step S 814 , if it is determined at Step S 812 that the number of DigRF packets reach 32, the SIR calculation unit 332 calculates an SIR. The SIR calculation unit 332 calculates likelihood based on the pilot symbols in the range specified by the pilot symbol range information, by taking a quarter chip as one sample. The SIR calculation unit 332 sums the calculation results of the likelihood. Namely, the SIR calculation unit 332 sums the likelihood calculated for chips included in DigRF packets other than the DigRF packet that includes the symbol in which an error is detected. [0124] If it is determined at Step S 812 that the number of DigRF packets does not reach 32, the process goes back to Step S 804 . [0125] At Step S 816 , the SIR calculation unit 332 executes an averaging process of the SIR. Namely, the SIR calculation unit 332 obtains the number of samples by excluding DigRF packets in which errors are detected, from the 32 DigRF packets. The SIR calculation unit 332 executes the averaging process of the SIR by dividing the total value of the likelihood by the number of samples. [0126] <Operations of Wireless Apparatus 100 > [0127] FIGS. 9A-9B illustrate operations of the wireless apparatus 100 according to the present embodiment. [0128] The wireless apparatus 100 operates in accordance with DigRF v4. [0129] At Step S 902 , the RFIC 200 receives a wireless signal from the other wireless apparatus. Namely, the retransmission control unit 208 receives IQ data as input from the RxADC 202 . [0130] At Step S 904 , the retransmission control unit 208 executes buffering of the IQ data, and inputs the IQ data to the LVDS driver 212 . [0131] At Step S 906 , the LVDS driver 212 generates a DigRF packet of the IQ data from the retransmission control unit 208 . The LVDS driver 212 outputs the DigRF packet to the LVDS receiver 304 . [0132] At Step S 908 , the LVDS receiver 304 receives the DigRF packet from the RFIC 200 . The LVDS receiver 304 inputs the DigRF packet from the RFIC 200 into the retransmission control unit 306 . [0133] At Step S 910 , the retransmission control unit 306 determines whether a data error is detected in the DigRF packet from the LVDS receiver 304 . [0134] At Step S 912 , if a data error is detected in the DigRF packet from the LVDS receiver 304 at Step S 910 , the error symbol part determination unit 308 determines the symbol in which the error is detected. The error symbol part determination unit 308 inputs the error symbol information into the pilot symbol range specification unit 316 . [0135] At Step S 914 , the pilot symbol range specification unit 316 specifies the range of pilot symbols used for calculating the transmission TPC bit based on the error symbol information from the error symbol part determination unit 308 . The pilot symbol range specification unit 316 inputs the pilot symbol range information into the SIR calculation unit 332 . [0136] At Step S 916 , the SIR calculation unit 332 executes an SIR calculation process. [0137] At Step S 918 , the transmission TPC bit determination unit 334 calculates the transmission TPC bit based on the SIR calculated by the SIR calculation unit 332 . [0138] At Step S 920 , the modulation unit 338 executes a modulation process of the IQ data to be transmitted. [0139] At Step S 922 , the transmission unit 342 transmits the transmission TPC bit calculated by the transmission TPC bit determination unit 334 and the IQ data modulated at Step S 920 . [0140] At Step S 924 , the retransmission control unit 314 makes a retransmission-request of the DigRF packet. [0141] At Step S 926 , the LVDS driver 312 generates a DigRF packet of the retransmission-request signal from the retransmission control unit 314 . The LVDS driver 312 transmits the DigRF-packeted retransmission-request signal to the RFIC 200 . [0142] At Step S 928 , the LVDS receiver 214 receives the DigRF-packeted retransmission-request signal from the LVDS driver 312 . The LVDS receiver 214 inputs the retransmission-request signal into the retransmission control unit 210 . [0143] At Step S 930 , the retransmission control unit 210 makes a retransmission-request to the retransmission control unit 208 based on the retransmission-request signal from the LVDS receiver 214 . In response to the retransmission-request from the retransmission control unit 210 , the retransmission control unit 208 inputs the IQ data to be retransmitted into the LVDS driver 212 . [0144] At Step S 932 , the LVDS driver 212 generates a DigRF packet of the IQ data from the retransmission control unit 208 for retransmission. The LVDS driver 212 outputs the DigRF packet to the LVDS receiver 304 . [0145] At Step S 934 , the LVDS receiver 304 receives the DigRF packet from the RFIC 200 . The LVDS receiver 304 inputs the DigRF packet from the RFIC 200 into the buffer 310 via the retransmission control unit 306 . [0146] At Step S 936 , the buffer 310 replaces IQ data among the stored IQ data that corresponds to the IQ data retransmitted from the retransmission control unit 306 . Namely, the buffer 310 updates the IQ data among the stored IQ data that corresponds to the IQ data retransmitted from the retransmission control unit 306 . The buffer 310 inputs the stored IQ data into the despreading unit 318 . [0147] At Step S 938 , the despreading unit 318 executes a despreading process for the IQ data from the buffer 310 . [0148] At Step S 940 , the CPICH demodulation unit 320 demodulates the CPICH. Also, at Step S 940 , the DPCH demodulation unit 320 demodulates the DPCH. [0149] At Step S 942 , the LVDS driver 312 generates a DigRF packet of the IQ data transmitted from the transmission unit 342 . The LVDS driver 312 transmits the DigRF-packeted IQ data to the LVDS receiver 214 . [0150] At Step S 944 , the LVDS receiver 214 receives the DigRF packet from the baseband processing apparatus 300 . The LVDS receiver 214 converts the DigRF packet from the baseband processing apparatus 300 into IQ data. The LVDS receiver 214 inputs the IQ data into the TxDAC 204 via the retransmission control unit 210 . [0151] At Step S 946 , the TxDAC 204 transmits the IQ data from the LVDS receiver 214 . [0152] By the operations of the wireless apparatus 100 in the present embodiment illustrated in FIGS. 9A-9B , the transmission TPC bit is calculated without waiting for the arrival of the retransmission data by the retransmission control. Therefore, the wireless apparatus 100 can shorten time for transmitting the uplink DPCCH having the transmission TPC bit mapped after the reception of a pilot. [0153] FIG. 10 illustrates an example where an SIR is calculated after waiting for retransmission of a DigRF packet if an error is detected in the DigRF packet from the RFIC. [0154] In FIG. 10 , similarly to FIG. 7 , a state is illustrated as an example where a delay offset of a maximum of 296 chips is generated by a soft handover. [0155] The RFIC receives a downlink DPCH 1000 , and generates a DigRF packet. The RFIC transmits the DigRF packet to the baseband processing apparatus ( 1002 ). Note that if an error is detected in the DigRF packet, the baseband processing apparatus makes a retransmission-request of the data. In response to the retransmission-request from the baseband processing apparatus, the DigRF packet corresponding to the retransmission-request is retransmitted from the RFIC. Namely, the retransmission control is executed for the DigRF packet. Therefore, the box 1002 includes transfer time and retransmission time. [0156] The baseband processing apparatus transmits the transmission TPC bit ( 1004 ). Specifically, the baseband processing apparatus calculates an SIR based on DigRF packets including the retransmitted DigRF packet, and calculates the transmission TPC bit. The baseband processing apparatus generates an uplink DPCCH including the transmission TPC bit. There are cases where time of 216 chips passes after the reception of the pilot at this moment. Although the 3GPP specifies that the transmission TPC bit is mapped into a TPC included in an uplink DPCCH at timing of 512 chips after the reception of the pilot symbol, it is too late. [0157] The baseband processing apparatus generates a DigRF packet of the uplink DPCCH including the transmission TPC bit, and transfers it to the RFIC. The RFIC transmits the uplink DPCCH including the transmission TPC bit ( 1010 ). In this case, the transmission TPC bit is mapped into a next slot. [0158] In the transmission power control process illustrated in FIG. 7 , the retransmitted DigRF packet is not used for calculating the transmission TPC bit. Therefore, time can be shortened for retransmission of the DigRF packet for the process of calculating the transmission TPC bit after the reception of the pilot. [0159] According to the present embodiment, if an error is detected in a DigRF packet from the RFIC 200 , the uplink DPCCH having the transmission TPC bit mapped can be transmitted at a timing of 216 chips after the reception of the pilot. Namely, time can be shortened for transmission of the uplink DPCCH having the transmission TPC bit mapped after the reception of the pilot. [0160] According to the present embodiment, in the wireless apparatus in accordance with DigRF v4, if an error is detected in a DigRF packet from the RFIC, the baseband processing apparatus calculates an SIR based on DigRF packets other than the DigRF packet. [0161] The baseband processing apparatus calculates the transmission TPC bit based on the SIR calculated based on DigRF packets other than the DigRF packet in which an error is detected. In this way, a process for calculating the transmission TPC bit is not influenced even if a retransmission process of a DigRF packet is executed. Namely, it is possible to shorten delay of transmission power control caused by delay of transmission of the transmission TPC bit. [0162] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

A wireless apparatus includes a wireless unit to convert a wireless signal received by an antenna into a baseband signal; and a baseband processing apparatus to receive a packet corresponding to the baseband signal via a communication line connected with the wireless unit, to detect an error in a transmission process of the packet via the communication line, to obtain the baseband signal based on packets other than the packet in which the error is detected, to generate transmission power information used for downlink transmission power control based on the obtained baseband signal, to transmit the baseband signal having the generated transmission power information reflected to the wireless unit via the communication line, and to have the wireless unit execute wireless transmission of a wireless signal corresponding to the baseband signal having the transmission power information reflected.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor memory device, and in particular, relates to a design for facilitating a test of a semiconductor memory device in which input and output of a plurality of data at the same address are allowed. 2. Description of the Related Art In recent years, semiconductor integrated circuit devices have been integrated to a higher extent, and in particular, the capacities of semiconductor memory devices have been significantly increased. This increase of the capacities, however, have caused the following disadvantages. In an 8-bit computer, data of 8 bits can be simultaneously handled, and a unit of data stored in a memory is generally 8 bits. Such memory device may be formed, using semiconductor memories each having a capacity of 16 mega (M) bits per one chip, as shown in FIG. 1. Referring to FIG. 1, a memory includes eight 16-Mbit semiconductor memory chips 212a-212h. One bit is stored at the same address of each of the memory chips 212a-212h, and data of 8 bits stored in the same address is handled as one byte. Thus, in a write operation, the same address in each of the memory chips 212a-212h is designated, and each bit in one byte is written in the corresponding memory chip. In a read operation, the same address in each of the memory chips 212a-212h is designated for reading one bit, whereby data of 1 byte is formed. In the memory thus constructed, addresses up to 16 Mbits are available in each memory chip. The semiconductor memory chip, in which different addresses are allocated to the respective bits in a 16 Mbit memory region, has been referred to as "16 Mbits×1" (or "16×1") structure memory. The memory in FIG. 1 using the eight memory chips of 16×1 structure can store the data of 16 Mbytes. However, such large capacity of one structure may cause a following disadvantage. If the memory capacity of a computer is insufficient, additional memories must be used. If the computer has used the memory of the structure shown in FIG. 1, eight memories each having the capacity of 16 Mbits must be added. Thus, the storage capacity of 16 Mbytes is additionally used. Eight semiconductor memory chips each having the capacity of 16 Mbits are used for this purpose. However, it is seldom required to add such large memory at a time. The addition of the many and large memory chips at one time is expensive. For example, in personal computers, if a memory consists of semiconductor chips of large capacities, a disadvantage may be caused relating to handling of the memories. In order to overcome the foregoing disadvantage, there has been proposed a method in which a storage capacity of one memory chip is unchanged, but a memory region of the one memory chip is divided into a plurality of memory sections (also referred to as "memory blocks"). Each memory block has addresses independent from those of the other memory blocks, and multiple data are stored at the same address in one chip. Referring to FIG. 2, description will be made on a semiconductor memory chip in which each memory region of 16 Mbits is divided into four memory blocks each having a capacity of 4 Mbits (this structure is referred to as "4 Mbits×4" structure or "4×4" structure). A semiconductor memory chip 214a includes memory blocks 216a, 218a, 220a and 222a each having a storage capacity of 4 Mbits. Each memory block stores one bit of data at one address. This memory chip 214a stores 4 bits at the same address. Similarly, the semiconductor memory chip 214b of 4×4 structure includes four memory blocks 216b (not shown), 218b, 220b and 222b. The memory chip 214b can store data of 4 bits at the same address. By using the combination of the two semiconductor memory chips 214a and 214b, data of 8 bits can be stored at and read from the same address. If two semiconductor memory chips each having the 4×4 structure are used, input and output of data of 1 byte is allowed. Consequently, two semiconductor memory chips each having a capacity of 16 Mbits can achieve a function similar to that of the memory shown in FIG. 1. The semiconductor memory chip having the 4×4 structure shown in FIG. 2 has an advantage that the storage capacity of a minimum unit can be reduced while using the semiconductor memory chip of a large capacity. In an example shown in FIG. 2, a function similar to that of the memory in FIG. 1 is achieved, and also the storage capacity is 4 Mbytes, i.e., a quarter of that (16 Mbytes) of the memory in FIG. 1. By reducing the unit of the storage capacity of the minimum structure, the unit of the storage capacity for addition can be significantly reduced, compared with that of the structure shown in FIG. 1. This enables a specific design of configuration of the memory, and facilitates the change of configuration. Particularly, if a main stream of computers changes from the current 16 bit computers to 32 bit computers, the unit of data handled in one time changes from 16 bits to 32 bits. If the memory of the configuration shown in FIG. 1 were used, the minimum unit of the memory would be 64 Mbytes (16 Mbits×32=2 Mbytes×32), which would be almost unnecessary for personal users. Also such memories are excessively expensive, and thus may be unavailable for the personal users in some cases. In such case, the memory chip shown in FIG. 2 can be expected to fully satisfy demand of such users. FIG. 3 is a block diagram showing a semiconductor memory chip having a structure similar to the semiconductor memory chip 214a of the 4 Mbits×4 structure, and specifically, showing a 1 Mbit semiconductor memory chip 230 of a 256 kilobit (Kbit)×4 structure. Referring to FIG. 3, the semiconductor memory chip 230 have pins 48, 50, 52, 66 which receive an external column address strobe (CAS) signal, a row address strobe (RAS) signal, a write control (WE) signal and an output enable (OE) signal, respectively. The semiconductor memory chip 230 also has address signal input pins 32 receiving an address signal (A 0 -A 8 ) of 9 bits, a power supply pin receiving a supply voltage Vcc, a ground pin receiving a ground potential Vss, four input/output pins (DO 1 -DO 4 ) 62 for transmitting data, and a no-connection pin (NC pin) 234. The semiconductor memory chip 230 is provided with a memory cell array 42 divided into four memory blocks 42a-42d. Each of the memory blocks 42a-42d has a storage capacity of 2 3 ×2 9 =256 Kbits. Thus, the memory cell 29 array 42 has a storage capacity of 1 Mbit as a whole. The semiconductor memory chip 230 further includes a row and column address buffer 34 connected to the address signal input pins 32, row and column decoders 36 and 38 connected to the row and column address buffer 34, and sense amplifiers 40 connected to the column decoder 38 and the memory cell array 42, as well as a data input buffer 44 and a data output buffer 46 connected between the sense amplifiers 40 and the input/output pins 62. CAS signal pin 48 and RAS signal pin 50 are connected to a clock signal generating circuit 232. The clock signal generating circuit 232 serves to apply a clock signal for determining an operation cycle of the semiconductor memory chip 230 to the row and column address buffer 34, row decoder 36, column decoder 38, sense amplifiers 40 and data output buffer 46. An AND circuit 56 is connected to the clock signal generating circuit 232 and the WE signal pin 52. The WE signal is applied to one of the inputs of the AND circuit 56 after being inverted. The AND circuit 56 is synchronized with the clock signal applied from the clock signal generating circuit 232 to apply the signal formed by inversion of the WE signal to the data input buffer 44 and data output buffer 46. The OE signal is applied to the data output buffer 46. The semiconductor memory chip 230 of the 256 Kbits×4 structure in the prior art shown in FIG. 3 operates as follows. The external row address signal is applied to the address signal input pins 32. The row and column address buffer 34 temporarily stores it and then applies the same to the row decoder 36. The row decoder 36 decodes the row address signal and selects corresponding one word line in each of the memory cell blocks 42a-42d. Then, the address signal input pins 32 receive the externally applied column address signal. The row and column address buffer 34 temporarily stores it and then applies the same to the column decoder 38. The column decoder 38 selects the corresponding bit line in each of the memory cell blocks 42a-42d by means of the sense amplifiers 40. In the data write operation, data of 4 bits are supplied through the I/O pins 62 to the data input buffer 44. The memory blocks 42a-42d each receive the 1 bit of the data through the sense amplifiers 40. In each of the memory blocks 42a-42d, the data of 1 bit is written into the memory cell located at the crossing of the selected word line and selected bit line. In the read operation, the memory cells are selected similarly to the foregoing write operation. In each of the memory blocks 42a-42d, 1 bit of the data is read from the memory cell located at the crossing of the selected word line and the selected bit line. The 4 bits thus read are applied through the sense amplifiers 40 to the data output buffer 46 and are temporarily stored therein. The data output buffer 46 externally supplies the data of 4 bits through the I/O pins 62 in response to the OE signal. Whether the semiconductor memory chip 230 of the 256 Kbits×4 structure operates normally or not can be determined in the following manner, using a dedicated tester. First, the tester is connected to the I/O pins 62, and predetermined data is written into each of the memory blocks 42a-42d. One bit of the data written in each memory block, i.e., 4 bits in total, is read from the same address in each memory block, and each data of 4 bits thus read is applied to the tester through the I/O pins 62. The tester compares the received 4-bit signal with the original data written at the address from which the received 4 bits are read. If all the bits coincide with each other, the tester determines as normal. If there is noncoincidence of at least one bit, it determines as abnormal, in which case the semiconductor memory chip is dealt with as unacceptable. The semiconductor memory device, which has the memory cell array divided into the multiple memory blocks as described above, has such a disadvantage that it requires many pins for the input and output of data, compared with the memory handling the whole memory cells as one address space. On the other hand, it has such an advantage that, since it allows simultaneous testing of all the memory blocks, it requires less time for testing the memory cell array, compared with the semiconductor memory chip having the memory cell array not divided into memory blocks and having an equal storage capacity. However, if the memory cell array were divided into more memory blocks in order to reduce the test time, the number of required I/O pins would also increase. This would also increase the number of pins in the tester, resulting in increase of cost of a hardware of the tester. SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide a semiconductor memory device, in which a memory region is divided into a plurality of memory sections capable of storing a plurality of data at the same address, and a test time can be reduced without increasing the number of pins. It is another object of the invention to provide a semiconductor memory device, in which a memory region is divided into a plurality of memory sections capable of storing a plurality of data at the same address, and a data input/output pin is used as an input pin for comparison data for reducing a test time while suppressing increase of the number of pins. It is still another object of the invention to provide a semiconductor memory device, in which a memory region is divided into a plurality of memory sections capable of storing a plurality of data at the same address, and a no-connection pin is used for reducing a test time without increasing the number of pins. It is yet another object of the invention to provide a semiconductor memory device, in which a memory region is divided into a plurality of memory sections capable of storing a plurality of data at the same address, and an existing input/output pin is used for reducing a test time without increasing the number of pins. It is further another object of the invention to provide a semiconductor memory device, in which a memory region is divided into a plurality of memory sections capable of storing a plurality of data at the same address, and an input/output pin to be used for another purpose is used for reducing a test time without increasing the number of pins. A semiconductor memory device according to the invention includes a circuit for supplying a mode designating signal having one of first and second values which are different from each other, a memory cell array including a plurality of memory sections, a selecting circuit for selecting the same address in each memory section for reading and writing data, a plurality of input/output pins, each of which is provided correspondingly to one of the memory sections for transmitting the data read and written by the selecting circuit, and a plurality of comparing circuits, which are arranged between the selecting circuit and the plurality of input/output pins and each are provided correspondingly to one of the memory sections, each comparing circuit being responsive to the second value of the mode designating signal to compare the data read from each memory section with data supplied through the corresponding input/output pin. In the semiconductor memory device, the data applied through the input/output pins is written by the selecting circuit at the same address in the plurality of memory sections in the memory cell array. The data read by the selecting circuit from the same address in the plurality of memory sections is likewise supplied through the input/output pins. The plurality of input/output pins, which are provided for the data read and written by the selecting circuit, also receive the data for comparison when the mode designating signal goes to the second value. The comparing circuit compares the data for comparison and the data read from the each memory section. Since the input/output pins, which are provided for the input and output of the data to and from the selecting circuit, can be also used for the input of the data for comparison, it is not necessary to additionally provide dedicated pins for the data of comparison, and thus increase of the number of the input/output pins can be prevented. Preferably, the semiconductor memory device further includes a coincidence detecting circuit, which is connected to an output of each comparing circuit for detecting whether or not all the data read from the respective memory sections coincide with the data supplied through the corresponding input/output pins. In this semiconductor memory device, the coincidence detecting circuit detects whether or not all the data read from the respective memory sections coincide with the corresponding data for comparison. Based on an output of the coincidence detecting circuit, it can be determined whether all the data stored at the same address in the respective memory sections have the correct values or not. Since the above comparison for the plurality of memory sections in the memory cell array can be carried out simultaneously, inspection of the stored data in the memory cell array can be carried out in a shorter time, compared with the conventional memory cell array having an equal storage capacity. More preferably, the semiconductor memory device includes a no-connection input/output pin, which is not used in an ordinary operation and is connected to an output of the coincidence detecting circuit. In this semiconductor memory device, the output of the coincidence detecting signal can be supplied through the no-connection or unused input/output pin, and thus can be determined without additionally providing a dedicated input/output pin. The no-connection pin can be effectively used, suppressing the increase of the number of pins in the semiconductor memory device. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows structure of a memory for an 8-bit computer using eight semiconductor memory chips each having a 16 Mbits×1 structure; FIG. 2 shows structure of a memory for an 8-bit computer using two semiconductor memory chips each having a 4 Mbits×4 structure; FIG. 3 is a block diagram of a semiconductor memory chip in the prior art; FIG. 4 is a block diagram of a semiconductor memory chip of a 256 Kbits×4 structure of an embodiment of the invention; FIG. 5 is a specific block diagram of a memory cell array; FIG. 6 is a block diagram of a test mode control circuit; FIG. 7 is a block diagram of a test mode circuit; FIG. 8 is a block diagram of a switch circuit; FIG. 9 is a block diagram of a data comparator; FIG. 10 is a block diagram of a superposing logic; FIG. 11 is a timing chart showing an ordinary write operation; FIG. 12 is a timing chart showing an ordinary read operation; FIG. 13 is a timing chart showing a test mode; FIG. 14 is a timing chart showing a test read operation; FIG. 15 is a block diagram of a semiconductor memory chip of a second embodiment of the invention; FIG. 16 is a block diagram of a test mode circuit of the second embodiment; FIG. 17 is a block diagram of a semiconductor memory chip of a third embodiment of the invention; FIG. 18 is a block diagram of a test mode circuit of the third embodiment; FIG. 19 is a block diagram of a latch circuit; and FIG. 20 is a block diagram of a latch circuit of another embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENT Semiconductor memories of several embodiments of the invention will be described hereinafter with reference to the drawings. In the embodiments described below, a memory cell array is divided into four memory blocks, but the number of the memory blocks is not restricted to four. FIG. 4 is a block diagram of a semiconductor memory chip 30 of a first embodiment of the invention. The semiconductor memory chip 30 includes pins 48, 50, 52, 66 for receiving CAS signals, RAS signals, WE signals and OE signals, respectively, and further includes address signal input pins 32 for receiving an address signal (A 0 -A 8 ) of 9 bits, I/O pins (DO 1 , DO 2 , DO 3 and DO 4 ) 62 for transmission of data, a power supply pin and a ground pin. The semiconductor memory chip 30 further has an error flag output pin 64 for supplying an error flag signal indicative of a result of test of a memory cell array cell, which will be described later. The error flag output pin 64 is the same as the NC pin 234 shown in FIG. 3. Referring to FIG. 4, the semiconductor memory chip 30 is provided with a memory cell 42 divided into four memory blocks 42a-42d. Referring to FIG. 5, each of the memory blocks 42a-42d of the memory cell 42 includes a plurality of word lines WL formed in a lateral direction, and a plurality of bit lines BL formed perpendicular to the word lines WL. A memory cell MC storing data of 1 bit is formed at each crossing of the word line WL and bit line BL. In this embodiment, each of the memory blocks 42a-42d includes 256K memory cells MC. Therefore, the memory cell array 42 has a storage capacity of 256 Kbits×4=1 Mbits. Referring to FIG. 4 again, the semiconductor memory chip 30 includes a row and column address buffer 34 which is connected to address signal input pins 32 for temporarily storing an externally supplied address signal, a row decoder 36 which decodes a row address signal supplied from the row and column address buffer 34 for selecting a predetermined word line WL in each of the memory blocks 42a-42d, a column decoder 38 which decodes a column address signal supplied from the row and column address buffer 34 for selecting a predetermined bit line BL in each of the memory blocks 42a-42d, sense amplifiers 40 for amplifying and reading data supplied from the selected memory cells in the memory blocks 42a-42d to the corresponding bit lines BL, a data output buffer 46, which is connected to the sense amplifiers 40 and OE pin 66 for temporarily storing the data of 4 bits supplied from the sense amplifiers 40, and a data input buffer 44, which is connected to the sense amplifiers 40 for temporarily storing the data of 4 bits to be written into the memory cell array 42. Between the I/O pins 62 and the data buffers 44 and 46, there is provided a test mode circuit 60, which is different from the semiconductor memory chip 230 in the prior art shown in FIG. 3, forming a feature of the invention. The output of the test mode circuit 60 is connected to the error flag output pin 64. The test mode circuit 60 will be described in detail later. The CAS pin 48 and RAS pin 50 are connected to a clock signal generating circuit 54, which supplies a clock signal to the row and column address buffer 34, row decoder 36, column decoder 38, sense amplifiers 40 and data output buffer 46 for deciding an operation cycle of the semiconductor memory chip 30. The WE pin 52 is connected to one input of an AND circuit 56, of which other input is connected to the clock signal generating circuit 54. The AND circuit 56 applies its output to the data input buffer 44 and data output buffer 46. The WE signal is applied to the AND circuit 56 after being inverted. The semiconductor memory chip 30 further includes a test mode control circuit 58, which is connected to the clock signal generating circuit 54, output of the AND circuit 56 and OE pin 66. The test mode control circuit 58 generates a test control signal 98 for changing internal connection of the test mode circuit 60 in accordance with the operational mode. Referring to FIG. 6, the test mode control circuit 58 receives the RAS signal, CAS signal, WE signal and OE signal. It also receives a PON signal, which is maintained at a low level (will be referred to as "L-level") for a predetermined time after power-on of the semiconductor memory chip 30 and then attains a high level (will be referred to as "H-level"). The clock signal generating circuit 54 shown in FIG. 4 applies a clock signal (not shown) to the test mode control circuit 58. Referring to FIG. 6, the test mode control circuit 58 includes an NOR circuit 80 having one input receiving the CAS signal and the other input receiving the WE signal, an inverter 82 having an input connected to an output of the NOR circuit 80, a latch circuit 84 receiving the RAS signal and an output signal of the inverter 82, an inverter 86 having an input receiving the RAS signal, a NAND circuit 88 having inputs connected to outputs of the inverter 86 and latch circuit 84, a latch circuit 90 receiving an output of the NAND circuit 88 and the PON signal, an inverter 94 having an input receiving OE signal, a NAND circuit 92 having inputs connected to outputs of the latch circuit 90 and inverter 94, and an inverter 96 having an input connected to an output of the NAND circuit 92. The latch circuits 84 and 90 are constructed as shown in FIG. 6. Referring to FIG. 7, the test mode circuit 60 includes four 1-bit test mode circuits 112, 114, 116 and 118, and a superposing logic 120 for superposing signals indicative of test results, which are supplied by the 1-bit test mode circuits 112, 114, 116 and 118, and applying the error flag signal 150 to the error flag output pin 64. The four 1-bit test mode circuits 112, 114, 116 and 118 have the same structures. For example, the 1-bit test mode circuit 112 includes a switch circuit 122 and a data comparator 130. The switch circuit 122 connects or disconnects the data input buffer 44 and data output buffer 46 to and from the I/O pin DO 1 in response to the test control signal 98. The data comparator 130 compares the data supplied from the data output buffer 46 with an expected value applied from a tester through the I/O pin DO 1 , and supplies the result of comparison to the superposing logic 120. The "expected value" is a value of the data, assuming that the data is correctly read from the corresponding address in each memory block. Since predetermined data has been written in each memory cell in an earlier stage of the test, the data thus written may be used as the expected value. Similarly to the 1-bit test mode circuit 112, the 1-bit test mode circuit 114 includes a switch circuit 124 and a data comparator 134. The 1-bit test mode circuit 116 includes a switch circuit 126 and a data comparator 136. The 1-bit test mode circuit 118 includes a switch circuit 128 and a data comparator 138. The switch circuits 124, 126 and 128 have structures similar to that of the switch circuit 122 except for that they are connected to different pins and comparators. The data comparators 132, 134 and 136 have structures similar to that of the data comparator 130. Therefore, they will not be detailed hereinafter. Referring to FIG. 8, the switch circuit 122 includes an inverter 142 for inverting the test control signal 98, and a transfer gate 144 which operates in response to the test control signal 98 and an output of the inverter 142. The transfer gate 144 has one input connected to the I/O pin DO 1 and the other input connected to the data input buffer 44 and data output buffer 46. Both terminals of the transfer gate 144 are connected to the data comparator 130. Referring to FIG. 9, the data comparator 130 includes an exclusive OR (will be referred to hereinafter as "EXOR") circuit 146 having one input connected to one of two terminals of the switch circuit 122, which is connected to the data input buffer 44 and data output buffer 46, and the other input connected to the I/O pin DO 1 of the switch circuit 122. An output of the EXOR circuit 146 is connected to the error signal superposing logic 120. Referring to FIG. 10, the superposing logic 120 includes an OR circuit 148 having four inputs connected to outputs of the data comparators 130, 132, 134 and 136, respectively. An output of the OR circuit 148 is connected to the error flag output pin 64. A signal supplied by the OR circuit is the error flag signal 150. Referring to FIGS. 4-10, the semiconductor memory chip 30 of this embodiment operates as follows. Now, operations for (1) ordinary write, (2) ordinary read, (3) test mode setting and (4) test read will be described below. (1) Ordinary Write Operation In the ordinary write operation, the respective signals shown in FIG. 6 and signals (A)-(H) supplied to or from the respective circuits change as shown in FIG. 11. After the power-on of the semiconductor memory chip 30, the PON signal maintains the L-level for a predetermined time, and then attains the H-level as shown in FIG. 11 (e). In response to the change of the PON signal to the L-level, the latch circuit 90 shown in FIG. 6 is reset and generates the output at the L-level as shown in FIG. 11 (j). Even after the signals RAS, CAS, WE and OE change as shown in FIG. 11 (a)-(d), the signal supplied to the latch circuit 90 is fixed at the H-level as shown in FIG. 11 (i). Therefore, the output of the latch circuit 90 is maintained at the L-level as shown in FIG. 11 (j), and the test control signal supplied from the test mode control circuit 58 is always maintained at the L-level as shown in FIG. 11 (m). Referring to FIG. 8, since the test control signal 98 is fixed at the L-level, the transfer gate 144 connects the data input buffer 44 and data output buffer 46 to the I/O pin DO 1 . In the ordinary write operation, the data to be written is supplied through the I/O pin DO 1 to the data input buffer 44, and is temporarily stored therein. Other switch circuits 124, 126 and 128 in FIG. 7 operate similarly. In this operation, as shown in FIG. 7, the four I/O pins DO 1 -DO 4 each supply 1 bit, i.e., 4 bits in total, to the data input buffer 44. The data input buffer 44 in FIG. 4 temporarily stores the 4 bits, and then supplies them to the sense amplifier 40. Referring to FIG. 4, the address signal input pins 32 receive the row address signal of 9 bits (A 0 -A 8 ). The row and column address buffer 34 temporarily stores the row address signal, and applies the same to the row decoder 36. The row decoder 36 decodes the applied row address signal, and selects corresponding one word line WL in each of the memory blocks 42a-42d. Then, the address signal input pins 32 receive the column address (A 0 -A 8 ). The row and column address buffer 34 temporarily stores the column address signal, and applies the same to the column decoder 38. The column decoder 38 decodes the column address signal, and selects the corresponding one bit line BL in each of the memory blocks 42a-42d through the sense amplifier 40. Thereby, the memory cells MC (see FIG. 5) at the same address in the memory blocks 42a-42d are selected. Respective one bit of the data of 4 bits stored in the data input buffer 44 is written into each selected memory cell MC. (2) Ordinary Read Operation FIG. 12 is a timing chart showing waveforms of respective portions of the test mode control circuit 58 in the ordinary read operation. The timing chart shown in FIG. 12 is substantially the same to the timing chart in the ordinary write operation shown in FIG. 11, except for FIG. 12 (k). Therefore, as shown in FIG. 12 (m), the test control signal 98 supplied from the test mode control circuit 58 shown in FIG. 6 is fixed at the L-level. Referring to FIG. 4 again, the address signal input pins 32 first receive the row address signal (A 0 -A 8 ). The row and column address buffer 34 temporarily stores the row address signal, and applies the same to the row decoder 36. The row decoder 36 decodes the row address signal, and selects corresponding one word line WL in each of the memory blocks 42a-42d. Then, the address signal input pins 32 receive the column address (A 0 -A 8 ). The row and column address buffer 34 temporarily stores the column address signal, and applies the same to the column decoder 38. The column decoder 38 decodes the column address signal, and selects the corresponding one bit line BL in each of the memory blocks 42a-42d through the sense amplifier 40. Thereby, the memory cells MC (see FIG. 5) at the same address, which is designated by the row address signal and column address signal, in the memory blocks 42a-42d are selected. The sense amplifier 40 reads the data from the selected memory cells MC through the bit lines BL, and applies the same to the data output buffer 46. One bit is read from one memory block. Therefore, 4 bits are read from the whole memory cell array 42 and are stored in the data output buffer 46. Referring to FIG. 8, since the test control signal 98 is fixed at the L-level, as described before, the transfer gate 144 is closed. The data output buffer 46 is connected to the I/O pin DO 1 . Referring to FIG. 7, the other switches 124, 126 and 128 are likewise closed. The data output buffer 46 is connected to the I/O pins DO 1 -DO 4 . Therefore, respective one bit of the data at the same address in each of the memory cells 42a-42d is supplied through each of the I/O pins DO 1 -DO 4 . (3) Test Mode Setting Operation When the semiconductor memory chip 30 in FIG. 4 is set at the test mode, respective signals in the test mode control circuit 58 have waveforms shown in FIG. 13. The test mode control circuit 58 in this embodiment is changed to the test mode when the respective RAS, CAS and WE signals which are externally applied attain a WCBR (Write CAS Before RAS) timing. Therefore, the test can be carried out by applying these signals at the timing shown in FIG. 13. Referring to FIG. 13, in the WCBR timing, the CAS and WE signals shown in FIG. 13 (b) and (c) are applied before the input of the RAS signal shown in FIG. 10 (a). In the test mode setting, OE signal may have any value. In accordance with the change of the RAS, CAS and WE signals shown in FIG. 13 (a)-(c), the latch circuit 90 in FIG. 6 latches the data at the level as shown in FIG. 11 (d), and the output of the latch circuit 90 is fixed at the H-level. As a result, the test control signal 98 supplied from the test mode control circuit 58 changes depending on the OE signal. (4) Test Read Operation FIG. 14 shows a timing chart of signals of various portions of the test mode control circuit 58 shown in FIG. 6 in the test read operation. As shown in FIGS. 14 (b) and (d), the OE signal changes at the same timing as the CAS signal. Thereby, the test control signal 98 supplied from the test mode control circuit 58 shown in FIG. 6 is kept at the H-level while the OE signal is maintained at the L-level, and otherwise is maintained at the L-level. Referring to FIG. 8, when the test control signal 98 is maintained at the L-level, the data output buffer 46 is connected to the I/O pin DO 1 . When the test control signal 98 attains the H-level, the transfer gate 144 opens, so that the data output buffer 46 is disconnected from the I/O pin DO 1 . Referring to FIG. 7, each of the switch circuits 124, 126 and 128 operates similarly to the switch circuit 122. It is assumed that the memory cell array 42 stores predetermined data previously written by the ordinary write operation. In the test read operation, one bit of data is read from the same address of each of the memory blocks 42a-42d by the operation similar to the operation in the ordinary read cycle, and is stored in the data output buffer 46. The data of 4 bits stored in the data output buffer 46 is applied to the 1-bit test mode circuits 112, 114, 116 and 118 in FIG. 7, respectively, each receiving one bit. Also the tester supplies data indicative of the respected values of the data to be read from the respective memory blocks through the corresponding I/O pins DO 1 -DO 4 in FIG. 7. For example, in the 1-bit test mode circuit 112 shown in FIG. 7, the switch circuit 122 is opened by the test control signal 98. Therefore, one bit, which is read, e.g., from the memory block 42a and applied by the data output buffer 46, and the expected value applied from the I/O pin DO 1 are applied to the data comparator 130. Referring to FIG. 9, the EXOR circuit 146 in the data comparator 130 supplies the signal at the L-level to the error signal superposing logic 120 if one bit supplied from the data output buffer 46 is coincident with the expected value applied from the I/O pin DO 1 . And otherwise the data comparator 130 applies the signal at the H-level to the error signal superposing logic 120. Referring to FIG. 7 again, the other comparators 132, 134 and 136 operate in a similar manner. The data comparator 132 supplies the signal at the L-level to the error signal superposing logic 120 when one bit supplied from the memory block 42b is coincident with the expected value applied from the I/O pin DO 2 , and otherwise applies the signal at the H-level to the error signal superposing logic 120. The data comparator 134 supplies the signal at the L-level to the error signal superposing logic 120 when one bit supplied from the memory block 42c is coincident with the expected value applied from the I/O pin DO 3 , and otherwise applies the signal at the H-level to the error signal superposing logic 120. The data comparator 136 supplies the signal at the L-level to the error signal superposing logic 120 when one bit supplied from the memory block 42d is coincident with the expected value applied from the I/O pin DO 4 , and otherwise applies the signal at the H-level to the error signal superposing logic 120. Referring to FIG. 10, the OR circuit 148 in the superposing logic 120 supplies the signal at the L-level to the error flag output pin 64 when all the signals applied from the data comparators 130, 132, 134 and 136 are at the L-level. The superposing logic 120 supplies the signal at the H-level to the error flag output pin 64 when at least one of them is at the H-level. Therefore, the signal supplied to the error flag output pin 63 attains the H-level when the data of 4 bits read from the memory blocks 42a-42d includes at least one bit different from the expected value. This signal 150 is referred to as an error flag signal. Referring to FIG. 4, when the error flag output pin 64 formed of an I/O pin which has not conventionally been used supplies the error flag signal at the L-level, all the 4 bits at the address which is being tested are confirmed to be correct values. If the error flag signal 150 is at the H-level, the 4 bits of the data which is being tested are found to include at least one error. Therefore, whether the memory cell array 42 contains a defect or not can be determined by observing the value of the error flag signal 150. In the semiconductor memory chip 30 in this embodiment, an NC pin, which has not conventionally been used, is used as the output pin for the error flag signal. Therefore, it is not necessary to additionally provide a pin dedicated to output of the error flag, and thus increase of the number of pins can be prevented. Since 4 bits of the memory cell array can be simultaneously tested, the time for the test of the memory cell array can be reduced, compared with the memory chip of the 1 Mbit×1 structure. It is not necessary to individually determine the defectiveness of each bit of the memory cell array, but it is necessary only to determine whether four bits are correct as a whole or include a defective bit(s). Therefore, only one error flag output pin is required, and thus increase of the number of pins can be suppressed. FIG. 15 is a block diagram of a semiconductor memory chip 160 of a 256 Kbits×4 structure of a second embodiment of the invention. The semiconductor memory chip 160 shown in FIG. 15 differs from the semiconductor memory chip 30 shown in FIG. 4 in that it includes, instead of the test mode circuit 60 in FIG. 4, an internal circuit used for the ordinary operation carried out in the semiconductor memory chip 160, an I/O pin 164 provided for the internal circuit, and a test mode circuit 162 which is connected to the I/O pins 62, data input buffer 44 and data output buffer 46. The test mode circuit 162 is controlled by the test mode control circuit 58 for supplying the error flag signal through the I/O pin 164 in the test operation. Referring to FIGS. 15 and 4, the same parts and portions bear the same reference numerals and names. They have the same functions. Therefore, they will not be detailed herein. Referring to FIG. 16, the test mode circuit 162 differs from the test mode circuit 60 shown in FIG. 7 in that it further includes a selector 166, which has one input connected to the output of the superposing logic 120 and the other input connected to the internal circuit (not shown). The selector 166 is controlled by the test control signal 98 to selectively connect the output of the superposing logic 120 or the output of the internal circuit to the I/O pin 164. In FIGS. 16 and 7, the same parts and portions bear the same reference numerals and names. They have the same functions, and therefore will not be described hereinafter. The semiconductor memory chip 160 and the test mode circuit 162 in the second embodiment operate as follows. In the ordinary read and write operations, the test control signal 98 is fixed at the L-level, as described before. All the switch circuits 122, 124, 126 and 128 are closed. Therefore, the I/O pins DO 1 -DO 4 are connected to the data input buffer 44 and data output buffer 46. Referring to FIG. 17, the selector 166 selects the output of the internal circuit to be connected to the I/O pin 164. In the ordinary write operation, the I/O pins DO 1 -DO 4 receive the data to be written into the memory cell array 42. In the ordinary read operation, the data read from the memory cell array 42 is externally supplied from the I/O pins DO 1 -DO 4 . The internal circuit (not shown) transmits signals to and from external circuits through the I/O pin 164. In the test mode, the test control signal 98 alternately attains the H-level and L-level at a predetermined timing. When the test control signal 98 is at the L-level, each of the switch circuits 122-128 is closed, similarly to the ordinary read and write operations. When the test control signal 98 attains the H-level, all the switch circuits 122, 124, 126 and 128 are closed. The selector 166 connects the output of the superposing logic 120 to the I/O pin 164. Referring to FIG. 16, the data comparator 130, e.g., in the 1-bit test mode circuit 112 compares one bit read from the memory block 42a with the expected value of one bit supplied through the I/O pin DO 1 , as already stated with reference to FIG. 7. When they are coincident with each other, the data comparator 130 applies the signal at the L-level to the superposing logic 120, and otherwise applies the signal at the H-level to the superposing logic 120. The other data comparators 132, 134 and 136 each carries out the similar operation in connection with 1 bit read from the corresponding memory block 42b, 42c or 42d, and apply the results of comparison to the superposing logic 120. As stated before, the superposing logic 120 applies to the I/O pin 164 through the selector 166 the error flag signal, which is at the H-level when at least one of the comparison results by the data comparators 130, 132, 134 and 136 indicates noncoincidence, and is at the L-level when all of them indicate coincidence. Therefore, by inspecting the value of the error flag signal appearing at the I/O pin 164, it is possible to determine whether all the data read from the same address in the memory blocks 42a-42d are correct or not. In the semiconductor memory chip of the second embodiment, the I/O pin, which is used for the internal circuit in the ordinary operation, is used for supplying the data flag signal therethrough in the test operation. Therefore, it is not necessary to provide a pin dedicated to output of the error flag signal, and thus pins do not increase in number. Since 4 bits of data in the memory cell array can be tested simultaneously, the time for the test can be reduced. The semiconductor memory chips of the first and second embodiments have a following advantage in connection with the test of a plurality of semiconductor memory chips. In the test of the plurality of semiconductor memory chips, generally it is not necessary to use different data as the test data to be written into the memory cell arrays. Therefore, the same test data can be written at the same address in all the semiconductor memory chips under test. When the data at the same address are to be tested, the same data can be applied as the expected value to each I/O pin of the plurality of semiconductor memory chips. Thus, a single tester can be used, and the data of 4 bits supplied from the tester can be divided and applied to the respective semiconductor memory chips. One error flag signal is obtained in connection with each semiconductor memory chip. The tester requires only one pin per one semiconductor memory chip for receiving the signal. The read data may be supplied into the tester through the I/O pin for comparing it with the expected value by the tester itself, in departure from the embodiments in which the comparison is carried out by the semiconductor memory chip. In this case, the number of pins required in the tester increases proportionally to the number of the conventional semiconductor memory chips to be tested and the number of pins of the conventional semiconductor memory chip. According to the semiconductor memory chips of the foregoing embodiments of the invention, however, a plurality of semiconductor memory chips can be readily tested in a short time without significantly increasing the number of pins of the tester. FIG. 17 is a block diagram of a semiconductor memory chip 180 of a third embodiment of the invention. The semiconductor memory chip 180 shown in FIG. 17 differs from the semiconductor memory chip 130 of the first embodiment shown in FIG. 4 in that it includes a test mode circuit 182, instead of the test mode circuit 60 for supplying the error flag signal to the error flag I/O pin 64 in FIG. 4. In the operation cycles for reading and comparing data in the test mode, the test mode circuit 182 temporarily holds the comparison result, e.g., in the latch circuit, and supplies the same through one of the I/O pins 62 (e.g., I/O pin DO 1 ) in the next operation cycle. In FIGS. 17 and 4, the same parts and portions bear the same reference numerals and names. They have the same functions, and thus will not be described herein. FIG. 18 is a block diagram of the test mode circuit 182 shown in FIG. 17. The test mode circuit 182 shown in FIG. 18 differs from the test mode circuit 60 shown in FIG. 17 in that it includes a latch circuit 184 and a selector 186. The latch circuit 184 has an input connected to the output of the superposing logic 120, and latches the error flag signal 150 in response to a latch signal 188 which is applied thereto with a predetermined relationship with respect to a timing of output of the error flag signal 150 from the superposing logic 120. The selector 186 is responsive to the clock signal to select either the terminal of the switch circuit 122 or the output of the latch circuit 184 to connect the same to the I/O pin DO 1 . In FIGS. 18 and 7, the same parts and portions bear the same reference numerals and names. They have the same functions, and thus will not be described herein. FIG. 19 is a circuit block diagram of an example of the latch circuit 184. Referring to FIG. 19, the latch circuit 184 includes an inverter 192 for inverting the latch signal 188, a transfer gate 194 operated by the latch signal 188 and an output of the inverter 192, and a latch which receives the error flag signal 150 through the transfer gate 194 and is formed of inverters 196 and 198. An output of the inverter 198 and an input of the inverter 196 are connected to the transfer gate 194. An output of the inverter 196 and an input of the inverter 198 are connected together, and a potential at this connected portion forms the error flag signal 190. The test mode circuit 182 shown in FIG. 18 operates as follows. In the ordinary read operation or ordinary write operation, the test control signal 98 is fixed at the L-level. The selector 186 connects the switch circuit 122 to the I/O pin DO 1 . Therefore, the data input buffer 44 and the data output buffer 46 are connected to the I/O pins DO 1 -DO 4 in the same fashion as that in the ordinary read operation and ordinary write operation of the test mode circuit 60 shown in FIG. 7, and the operation is carried out in the same manner. In the test mode operation, the test control signal 98 alternately attains the H-level and L-level at a predetermined timing. When the test control signal 98 is at the L-level, the connection of test mode circuit 182 is as described before. When the test control signal 98 attains the H-level, the connection of the test mode circuit 182 changes as follows. In a first operation cycle, the selector 186 connects the switch circuit 122 and the I/O pin DO 1 . The switch circuit 122 is open. Thus, the data comparator 130 receives 1 bit read from the memory block 42a and the expected value applied from the I/O pin DO 1 . The data comparator 130 applies the signal indicative of the result of comparison, i.e., the signal at the L-level indicative of coincidence or the signal at the H-level indicative of noncoincidence, to the superposing logic 120. The other comparators 132, 134 and 136 operate similarly with respect to the data read from the memory blocks 42b, 42c and 42d and the expected values. Each signal indicative of the comparison result is applied to the superposing logic 120. The superposing logic 120 superposes these four signals, and supplies to the latch circuit 184 the error flag signal 150, which is at the L-level when all the input signals are at the L-level, and otherwise is at the H-level. The latch circuit 184 temporarily holds the error flag signal 150 in response to the latch signal 188, and applies the same to the selector 186. In the subsequent operation cycle in the test mode, the selector 186 connects the output of the latch circuit 184 and the I/O pin DO 1 . Therefore, the error flag signal 150 supplied by the superposing logic 120 is sent through the I/O pin DO 1 . The tester applies the expected value to each of the I/O pins DO 1 -DO 4 at the first operation cycle in the test mode, and reads the error flag signal 150 from the I/O pin DO 1 at the next operation cycle. By inspecting the value of the error flag signal 150, it is possible to determine whether all the data at the address in question in the memory blocks 42a-42d are correct or not. In the semiconductor memory chip of the third embodiment, the I/O pins are also used as the pins for supplying the error flag signals. Although the operation time for the test is slightly longer than those of the first and second embodiments, the pin dedicated to the output of the error flag signal is not required. Therefore, the number of the pins does not increase. FIG. 20 is a block diagram of another example of the latch circuit 184. Referring to FIG. 20, the latch circuit 184 includes a field effect transistor 200 and a capacitor 202. The latch signal 188 is applied to a gate of the field effect transistor 200. When the field effect transistor 200 is turned on in response to the latch signal 188, the error flag signal 150 is applied to the capacitor 202. When the field effect transistor 200 is turned off, a charge corresponding to the error flag signal remains in the capacitor 202. A potential of a junction between the field effect transistor 200 and the capacitor 202 forms an error flag signal 190 supplied therefrom. Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.

A semiconductor memory device capable of storing a plurality of bits at the same address and of reducing a test time without increasing the number of pins includes comparing circuits located between a plurality of memory cell blocks from which data at the same address is read, and an input/output pin used in ordinary operations for reading and writing data. The comparing circuits serve to detect coincidence and non coincidence of the data from the memory cell blocks and the pin. Preferably, there is provided a logic for superposing outputs of the comparing circuits. An error flag signal supplied from the superposing logic is transmitted through a no-connection pin, thereby reducing the number of pins.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 62/084,744 filed on Nov. 26, 2014. The disclosure of this application, along with any other United States patents and United States patent Publications identified in this specification, are hereby incorporated by reference. FIELD OF USE The present disclosure generally relates to an electrical stimulator and, more particularly, a mobile, electrical stimulator system for peripheral electrical stimulation. BACKGROUND Neurostimulation and brain stimulation can provide functional and/or therapeutic outcomes. While existing systems and methods provide benefits to individuals requiring neurostimulation, many quality of life issues still remain. For example, existing systems are performed solely in a clinical setting under the supervision of a clinician limiting the applicable uses and the time available for stimulation. Furthermore, the controllers utilized in these clinical settings, by today's standards, are relatively large and awkward to manipulate and transport. There exist both external and implantable devices for providing neurostimulation in diverse therapeutic and functional restoration indications. These neurostimulators are able to provide treatment therapy to individual portions of the body. The operation of these devices typically includes use of an electrode placed either on the external surface of the skin and/or a surgically implanted electrode. In the case of external neurostimulators, surface electrodes and/or percutaneous lead(s) having one or more electrodes are used to deliver electrical stimulation to select portion(s) of the patient's body. For example, transcutaneous electrical nerve stimulation (“TENS”) is delivered through electrodes placed on the skin surface, but has not achieved widespread use due to discomfort of the therapy, muscle fatigue, and the limited efficacy. TENS is similar to electrical muscle stimulation, although the latter is intended for stimulating muscles rather than nerves. Several clinical and technical issues associated with surface electrical stimulation have prevented it from becoming a widely accepted treatment method. First, stimulation of cutaneous pain receptors cannot be avoided resulting in stimulation-induced pain that limits patient tolerance and compliance. Second, electrical stimulation is delivered at a relatively high frequency to prevent stimulation-induced pain, which leads to early onset of muscle fatigue. Third, it is difficult to stimulate deep nerves with surface electrodes without stimulating overlying, more superficial nerves resulting in unwanted stimulation. Further still, clinical skill and intensive patient training is required to place surface electrodes reliably on a daily basis and adjust stimulation parameters to provide optimal treatment. The required daily maintenance and adjustment of a surface electrical stimulation system is a major burden on both patient and caregiver. A number of previous systems for spinal cord stimulation (e.g., at the dorsal root ganglion) and/or other deep tissue stimulation require surgical implantation of electrodes and/or other devices for delivering the therapy. These therapies necessarily incur the cost and medical risks associated with invasive surgical procedures, and they may restrict the mobility of the patient, both in terms of the surgical procedure itself and, in some cases, in the post-operative activities an ambulatory patient may wish to engage in while in his or her home environment. Moreover, many previous stimulation systems require complex engagement systems to operatively attach a lead with a stimulator. These systems often require separate tools to operatively attach the lead with the stimulator, require more than one person to accomplish, or are difficult to operatively attach. Often a connector is utilized to operatively attach the lead with the stimulator. These connectors are often uncomfortable for the patient to wear, require significant dexterity from the clinician to attach and/or require additional tools to attach. U.S. Pat. Nos. 6,845,271 and 8,249,713 describe methods of treating shoulder dysfunction by way of percutaneous, electrical stimulation. Specific, asynchronous stimulation profiles are delivered via a plurality of spiral or helix wire electrodes with terminal barbs inserted into the targeted muscles. The electrodes may be inserted by a hypodermic needle or surgical procedure. U.S. Pat. No. 7,376,467 discloses a neuromuscular stimulation assembly including a steerable introducer defining an interior lumen that shields the electrode from contact with tissue during insertion. Electrodes suitable for this assembly may be transcutaneous or percutaneous. The assembly includes a carrier, adhesively held to the patient, having an electronics pod for generating the desired electrical current patterns and an optional power input bay to enable changing the batteries for the assembly. Electrical connections between the electrodes and the power source are established via troughs that are integrally formed on the pod. U.S. Pat. No. 8,463,383 contemplates neurostimulation assemblies for short-term therapy or diagnostic testing via a fine wire electrode. The assembly includes a carrier and an optionally removable electronics pod associated with that carrier. The pod generates the stimulating pulses and includes user interface components. A power source and optional memory unit are contained within the assembly and, more specifically, possibly within the return electrode itself. U.S. Pat. Nos. 8,626,302 and 8,954,153 and United States Patent Publication 2013/0238066 disclose methods of alleviating pain via percutaneous and/or peripheral nerve electrical stimulation. As with other methods noted above, a hypodermic needle and lumen combination may deliver the lead. Various stimulation parameters are disclosed therein. U.S. Pat. No. 8,700,177 describes a system and method involving the use of an adhesive patch with a mounting structure directly mated to an electrical stimulation device. A percutaneous electrode is electrically coupled to the stimulation device. The device has a low profile and may be controlled wirelessly or by way of a plugged connection. A rechargeable battery powers the device, which may be inductively charged. SUMMARY A compact, mobile system for peripheral electrical nerve stimulation is disclosed. This system allows for the targeted delivery of stimulation while bypassing cutaneous pain receptors and without the need for open or invasive surgical procedures. The system allows for a relatively wide range of possible pulse profiles, while reducing the risk of muscle fatigue and minimizing the need for patients to rely on skilled personnel to maintain or monitor the system. One particularly relevant aspect of the system is that it includes one or more “breakaway” connections to ensure that the electrode and/or lead does not become dislodged in the event of inadvertent or unwanted forces being applied to the lead or its connections, e.g., application of a predefined force causes the patient cable (or lead) to break away from the stimulator. These breakaway connections may fully disconnect and/or simply reduce the tension of the connections to ensure that the electrode is unaffected. Further, the system can provide an alert to the user in the event of disconnection or reduction in tension so that the user can confirm the system is still in operational. These features, whether considered singly or in combination, prevent the user from being confined to a clinician's office (or other restricted movement/access areas) during the treatment and, instead, allow the user to engage in everyday activities. The system is easier to use for the patient and allows the clinician to affix it to the patient. The system does not require tools to operatively attach the lead with the stimulator. Further still the system may allow a clinician to only use a single hand to operatively connect the system together. Another aspect of the system is that it may be lightweight, has a generally low profile and is adaptable. In particular, after the electrode is positioned within the body, the combination of the adhesive bandage, the lead connector and the patient cable may allow the user to adjustably position the stimulator pod in a convenient position on his or her body. The lead connector and other system elements may be augmented to accommodate multiple electrodes, thereby enabling coordinated therapies across regions of the body. The system elements may be wirelessly connected to minimize physical connections and maximize user comfort. Additionally, the stimulator pod and controller pod may be further augmented through use of a programmer unit during the treatment, so that the clinician or even the user can directly control the process. As noted above, the breakaway feature may permit disconnection of the patient cable from the stimulator pod when a predefined force is applied. The system on the body may maintain sufficient attachment force between the lead and stimulator pod to remain operatively connected during a wide range of patient activities during which therapy may be needed. At the same time, the system may be able to disconnect the patient cable from the stimulator pod safely and/or comfortably without damaging and/or displacing the system and/or any of its components (e.g. lead, connectors, stimulator, pad, etc.) and/or without injuring or causing pain or discomfort to the patient. In other words, the system permits the connection between the patient cable and stimulator pod to remain mechanically and electrically connected when desired but also may enable safe disconnection when necessary (such as mechanically and/or electrically). This may also enable a patient to reconnect without clinician support (enables patient to safely resume therapy without having to return to clinician to have a lead, system, or other system component repaired, replaced, reprogrammed, and/or repositioned). In addition to protecting the lead connector (and the attached percutaneous lead) from accidental forces on the patient cable from catching or snagging on clothing, handled objects, or objects in the environment. Specific embodiments of the present teachings may include any combination of the following features: a helical, wire electrode, carried within an introducer (e.g., a disposable hypodermic needle or sheath); an adhesive patch at least partially securing a proximal end of the electrode protruding from the body; a lead connector, fixed to the proximal end of the electrode; a patient cable detachably connected to the lead connector, a stimulator pod, including a power source and a return electrode, detachably connected to the patient cable and forming an electrical connection between the pod and the electrode to deliver therapeutic stimulation; a controller pod in communication with the stimulator pod; a programmer unit in communication in the controller pod and/or stimulator pod wherein the programmer unit selectively delivers instructions to inform the therapeutic stimulation; wherein the electrode, the lead connector, patient cable and stimulator pod form a series of detachable connections having tension and, in response to a disconnection force, at least one of the following occurs: the tension is temporarily reduced and the patient cable detaches from the lead connector; wherein at least one of the detachable connections is established by way of at least one selected from: a magnet and a releasable, spring-loaded connection, a connector having a predefined holding strength; wherein the programmer unit communicates with the controller pod by way of a wireless connection; wherein the needle includes at least one test stimulation electrodes, controlled by the controller pod to aid in the positioning of the electrode; wherein the needle includes at least one test stimulation electrodes, controlled by at least one of the controller pod and the programmer pod to aid in the positioning of the electrode; wherein the lead connector is bifurcated to enable connection of a plurality of electrodes; wherein the patient cable comprises a plurality of segments in which each segment is detachably connected; wherein a plurality of stimulator pods may be provided in combination with a plurality of electrodes and wherein the controller pod coordinates stimulation among the stimulator pods; wherein the stimulator pods communicate wirelessly with the controller pod; wherein the lead connection further comprises a mechanical connector that receives and holds the proximal end while maintaining an electrical connection between the electrode and the patient cable; wherein the mechanical connector releasably and resettably moves in response to the force; wherein the lead connector mechanically secures the lead and electrically connects to it in response to a force applied by the user, wherein the mechanical connector comprises a rotating element; wherein the mechanical connector comprises a funnel that may have a controllably collapsible segment and wherein the proximal end of the lead received through said funnel and said controllably collapsible segment engages a portion of the electrode close to the proximal end; wherein the rotating element of the lead connector is electrically connected to the lead and to the series of detachable connections ending at the stimulator pod; wherein at least one of the stimulator pod and the controller pod provide a user alert when a predetermined amount of force is applied, e.g., an amount to dislodge the patient cable; wherein the user alert includes at least one of the following: a visual cue and an auditory cue; wherein the magnet comprises at least one insert molded neodymium magnet; wherein the magnet is shielded to reduce unintended magnetic fields and concentrate or focus the filed between the two ends of the breakaway mechanism; wherein the tension is reduced to a predetermined level and, upon the force exceeding the predetermined level, the patient cable detaches; wherein the predetermined level is less than or equal to a fraction (e.g., one half, 90%, 80%, 70% etc.) of a force required to change position of the lead connector on the body; wherein at least one end of the patient cable includes a connection member that is mated to a corresponding connection member on at least one of the lead connector and the stimulator pod; and wherein there may be a plurality of mated connection members and each set of mated members has a unique shape to avoid improper connections. A percutaneous electrical stimulator system may include an electrode percutaneously insertable into a patient, an adhesive bandage at least partially securing a proximal end of the electrode protruding from the patient, a lead connector, fixed to the proximal end of the electrode, a patient cable detachably connected to the lead connector, and a stimulator connected to the patient cable and forming an electrical connection between the stimulator and the electrode to deliver therapeutic stimulation. The percutaneous electrical stimulator system describe above: wherein the electrode, the lead connector and the patient cable form a series of detachable connections having tension and, in response to a disconnection force, at least one of the following occurs: the tension is temporarily reduced and the patient cable detaches. wherein at least one of the detachable connections is established by way of at least one selected from: a magnet and a releasable, spring-loaded connection, a mechanical connection. wherein a portion of the series of detachable connections is engaged via a rotating element, said rotating element adjusting the tension in response to the disconnection force. further comprising a controller in communication with the stimulator. wherein the stimulator communicates wirelessly with the controller. further comprising a programmer unit in communication with the controller wherein the programmer unit selectively delivers instructions to inform the therapeutic stimulation. wherein the programmer unit communicates with the controller by way of a wireless connection. wherein at least one of the stimulator and the controller provide a user alert when the response to the force occurs. wherein the user alert includes at least one of the following: a visual cue, tactile cue and an auditory cue. further comprising a programmer unit in communication with the stimulator, wherein the programmer unit selectively delivers instructions to inform the therapeutic stimulation. wherein the lead connector is plurally split to enable connection of a plurality of electrodes. wherein the patient cable comprises a plurality of segments in which each segment is detachably connected. wherein a plurality of stimulators are provided in combination with a plurality of electrodes and wherein the controller coordinates stimulation among the stimulator. wherein the stimulators communicate wirelessly with the controller. wherein the lead connection further comprises a mechanical connector that receives and holds the proximal end while maintaining an electrical connection between the electrode and the patient cable. wherein the mechanical connector releasably and resettably moves in response to the disconnection force. wherein the mechanical connector comprises a rotating element. wherein the mechanical connector comprises a funnel with a controllably collapsible segment and wherein the proximal end received through said funnel and said controllably collapsible segment engages a portion of the electrode proximate to the proximal end. wherein the magnet comprises at least one insert molded magnet formed from at least one of neodymium, samarium cobalt, alnico, and ferrite. wherein the magnet is shielded to reduce unintended magnetic fields and/or to concentrate intended magnetic fields from the magnet. wherein the tension is reduced to a predetermined level and, upon the disconnection force exceeding the predetermined level, the patient cable detaches. wherein the predetermined level is less than or equal to a percentage of force required to change position of the electrode within the patient. wherein at least one end of the patient cable includes a connection member that is mated to a corresponding connection member on at least one of the lead connector and the stimulator. wherein there are a plurality of mated connection members and each set of mated members has a unique shape to avoid improper connections. A percutaneous electrical stimulator system may include an electrode percutaneously insertable into a patient, a lead extending from the electrode, a lead connector, fixed to the lead, a patient cable detachably connected to the lead connector, and a stimulator connected to the patient cable and forming an electrical connection between the stimulator and the electrode to deliver therapeutic stimulation. The percutaneous electrical stimulator system describe above: wherein the lead is a helical wire lead with the electrode integrally formed at an end thereof. A percutaneous electrical stimulator system may include a wire electrode percutaneously insertable into a patient, the electrode having a proximal end extending from the patient when inserted therein, a lead connector, fixed to the proximal end of the electrode, a patient cable detachably connected to the lead connector, a stimulator connected to the patient cable and forming an electrical connection between stimulator and the electrode to deliver therapeutic stimulation. The percutaneous electrical stimulator system describe above: further comprising a controller in communication with the stimulator wherein the electrode, lead connector and patient cable form a series of detachable connections having tension and, in response to a disconnection force, at least one of the following occurs: the tension is temporarily reduced and the patient cable detaches. wherein at least one of the detachable connections is established by way of at least one selected from: a magnet and a releasable, spring-loaded connection. wherein the electrode is covered by an electrical insulation except at a distal end thereof. wherein the mechanical connector comprises a rotating element providing motion and force to cut or pierce the electrical insulation and to mechanically secure the lead. These and other features and advantages of the present teachings are set forth in the following specification, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings, in which: FIG. 1 is a schematic representation of one embodiment of the present teachings. FIGS. 2A and 2B illustrate selected components in one embodiment of the present teachings. FIGS. 3A, 3B and 3C are diagrammatic representations of the lead connector used in various embodiments of the present teachings. FIGS. 4A and 4B diagrammatically illustrate potential mating connections for the magnets and other detachable connections. FIG. 5 diagrammatically illustrates a spring-loaded and/or magnetic connection that can be used in the detachable connections. FIG. 6 is a perspective view of an embodiment of an adhesive bandage of the present teachings. FIG. 7 is a perspective view of an embodiment of an adhesive bandage of the present teachings attached to a patient. FIG. 8 is a perspective view of the adhesive bandage being removed from the patient. FIG. 9 is a perspective view of the patient with a lead inserted at an insertion site with the lead connector attached to the lead and adhesive bandage removed. FIG. 10 is a perspective view of the adhesive bandage being attached to a patient. FIG. 11 is a perspective view of the lead connector operatively attached with the stimulator pod through the patient cable with the adhesive bandage attached to the patient. FIG. 12 are schematic views of embodiments of a lead connector. FIG. 13 are schematic views of embodiments of a lead connector with lead storage mechanism. FIG. 14 are schematic views of embodiments of a lead connector with lead storage mechanism. FIG. 15 are schematic views of embodiments of a lead connector. FIG. 16 are schematic views of embodiments of a lead connector. FIG. 17 are schematic views of embodiments of a lead connector with a storage device. FIG. 18 are schematic view of embodiments of the lead connector and stimulator pod with patient cables with breakaway mechanisms. FIG. 19 are graphical representations of stimulation intensity with amplitude and pulse duration. FIG. 20 is a perspective view of embodiments of an IDC. FIG. 21 is a perspective view of embodiments of an IDC. FIG. 22 is a cross-sectional view of a portion of a breakaway mechanism. FIG. 23 is a cross-sectional view of a portion of a breakaway mechanism. FIG. 24 is a cross-sectional view of a breakaway mechanism. FIG. 25 is a cross-sectional view of a portion of a breakaway mechanism. DETAILED DESCRIPTION Reference will now be made in detail to exemplary embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the present teachings. Moreover, features of the various embodiments may be combined or altered in any combination without departing from the scope of the present teachings. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the present teachings. As noted above, previous neurostimulation and neuromodulation systems have inherent weaknesses. For example, these weaknesses may include difficulty using the stimulator while it is mounted on difficult to reach position of the body, a position on the body that is subject to frequent movement, including, without limitation the patient's arm, back, leg, head, shoulder, etc. Further, it may be difficult for a clinician to couple the stimulator with the lead, including, without limitation a fine-wire lead and may be difficult for the clinician to work with the system while on the patient body. Further still another weaknesses may include inherent difficulty with operating the system while it is adhered to the body, a complex user interface, difficulty replacing bandages without fear of dislodging the electrode, and discomfort due to system size and shape. Certain embodiments of the present teachings overcome these weaknesses and provide additional advantages, as will be recognized by persons of skill in this field. FIG. 1 schematically illustrates components of one embodiment of the invention. The percutaneous stimulation system 10 may include an electrode, such as a fine-wire electrode 18 . The electrode 18 may be initially introduced to the body by way of a hypodermic needle (not shown) or any other method of insertion. The present teachings are not limited to a specified type of insertion method or apparatus. Any appropriate system may be utilized without departing from the present teachings. The electrode 18 may include a lead 20 extending therefrom such as a micro-lead, fine-wire lead or simply lead. The lead 20 may possess a generally small diameter in comparison to previous systems, with optimal sizes of less than 1.0 mm and, more preferably, less than 0.6 mm. Further, the electrode 18 and/or lead 20 may have a generally coiled or helical structure, rather than a smooth cylinder. However, the present teachings are not limited to this structure. Any appropriate configuration may be utilized without departing from the present teachings. For the sake of clarity, the term “proximal” in the context of this application typically refers to the end of the electrode that is not inserted into the body and “distal” typically refers to the electrode end that is inserted into the body near the nerves. Depending upon the manufacture of the electrode structure, this proximal end may be wrapped in an insulating or protective coating or wrap. To the extent electrical connections must be made with the proximal end, the components at issue will allow for the removal of such coating(s)/wrap(s). After the electrode 18 is positioned within the body 12 at a desired therapeutic location, the proximal end of the electrode may be covered by an adhesive bandage 22 and attached to a lead connector 30 . The adhesive bandage 22 may have an adhesive to at least partially cover and, in some instances, guide the proximal end toward the lead connector 30 . The adhesive bandage 22 may take any number of shapes, including, without limitation the shape depicted in FIG. 2A , and the adhesive may be selectively applied to portions of the periphery to better ensure that the proximal end is not inadvertently ensnared when making the necessary connections within the system 10 . The adhesive bandage 22 may be made of any appropriate thin film material, such as polyethylene, and with one or more optional absorbent pads and/or non-adhesive removal tabs. The adhesive bandage 22 may also be carried on a disposable backing that may release the adhesive bandage 22 immediately prior to its application on the body 12 . Embodiments of the adhesive bandage 22 are shown in FIGS. 6-11 . The adhesive bandage 22 may eliminate the need for a separate tape to secure the lead connector 30 . The adhesive bandage 22 may be an integral system component that may generally protect the lead 20 exit site by managing exposure to potential contaminants (e.g., water, dirt, pathogens, virus, bacteria, etc.), thus helping to prevent infection of the site. The adhesive bandage 22 may further generally protect the lead 20 and more specifically the electrode 18 from accidental dislodgement caused by snagging (e.g., on a body part, clothing or furnishings). The adhesive bandage 22 may also generally secure the lead connector 30 to the patient's skin to isolate the lead 20 from forces applied to the lead connector 30 , such as during system 10 maintenance and daily activities of living. The adhesive bandage 22 may be a covering bandage that integrates with the lead connector 30 to allow the user to easily and consistently remove and replace the adhesive bandage 22 without fear of inadvertently pulling the lead 20 and/or electrode 18 . The adhesive bandage 22 may include a film body 42 and skin adhesive 44 that ensures that adhesion to skin will be appropriate for use on human skin. The film body 42 may be of any appropriate material, including, without limitation a clear polyethylene or any other material that generally protects a wound and discourages infection. The adhesive bandage 22 may be of any appropriate shape, including, without limitation a generally elliptical shape. The skin adhesive 44 may be applied along the perimeter such that the lead 20 is not exposed to any skin adhesive 44 . The skin adhesive may 44 may have the appropriate amount of tackiness to generally prevent inadvertent release from the skin. The skin adhesive 44 may extend generally around the perimeter of the film body 42 of the adhesive bandage 22 . This may create a seal to generally prevent contaminants from entering anywhere around the entire perimeter. Further, this may make the adhesive bandage 22 easier to remove so that it does not stick to the lead 20 upon removal. The adhesive bandage 22 may include a cutout section 48 over the lead connector 30 that may eliminate gaps in the seal and allows the user to use a finger to hold the lead connector 30 firmly against the skin during replacement of the adhesive bandage 22 . As noted above, the lead connector 30 and adhesive bandage 22 may be contoured to fit together—this may result in a better seal. The adhesive bandage 22 may include a removal tab 56 . A patient and/or clinician can put his or her finger over the bandage portion 52 and lead connector 30 to generally prevent the lead 20 and electrode 18 from pulling from the skin. This may be particularly useful in difficult to reach positions on the patients body and on body parts with frequent movement, e.g., legs, arms, back, head, etc. The film body 42 of the adhesive bandage 22 may include a generally see-through, translucent, clear, etc. body with a bandage portion 52 . The bandage portion 52 may include an absorbent pad configured to generally absorb any fluid exiting the lead insertion site, e.g., any kind of liquid (including, without limitation, blood) that may ooze from the lead insertion site will be absorbed into the bandage portion 52 . The size of the bandage portion 52 may still allow the patient and/or clinician to view the area around the lead exit site to determine the existence of any infections. Having the clear film body 42 further allows the patient and/or clinician to view the lead exit site. The adhesive bandage 22 may help keep fluid from obstructing a view of the skin to help identify if any infections are present on the patient. Further, the proximal end of the electrode 18 or lead 20 may be received by and coupled to the lead connector 30 . The lead 20 is fed into the lead connector 30 via a slot 62 , funnel 71 or other guide, as generally depicted by the arrows in FIGS. 3A and 3B . Once the lead 20 is received, coupling may occur compressively by collapsing a portion of the structure, using a screw, a sliding plate, a lever, friction fit, bayonet, magnet, gripping tabs or other physical means that allow a user to couple the pieces with only one hand. Upon collapse or compression, the lead connector 30 may be fixed to the proximal end of the electrode 18 or lead 20 . In some embodiments, the lead connector 30 may include gripping teeth, blades or other implements that enhance an interference or friction to securely grip the lead 20 . In some cases, the element connecting the lead connector 30 to the electrode 18 may also serve to remove unwanted insulation or coatings from the surface of the proximal end of the electrode 18 , thereby improving both the mechanical and electrical contact established by lead connector 30 . The lead connector 30 may fix the lead 20 in a manner that involves only one hand, by either the clinician or the user. The present teachings may include designs to facilitate the use of the lead 20 and electrode 18 for testing, a non-limiting example being the lead connector 30 that may electrically and operatively connect the proximal end of the lead 20 to an external stimulator pod 40 via a wire, such as a patient cable 50 , quickly and effectively. The patient cable 50 may be of any appropriate configuration and may provide a strong/stable mechanical and/or electrical connection. This configuration may reduce the duration of the procedure to install on the patient. Being able to easily remove the lead connector 30 also may reduce the procedure time. A non-limiting example may include a lead connector 30 having a funnel end 71 such that an end of the lead 20 can easily be inserted into the funnel 71 . The funnel 71 may guide the lead 20 into the lead connector area, where teeth, loops, or surfaces that are spring-loaded may be manipulated by the user via levers or buttons to clamp onto and create an electrical connection with the lead 20 . This lead connector 30 may have a wire and plug attached with allows for connection with an external stimulator. The funnel 71 may make it easier to guide a small lead therein. The funnel 71 may guide the proximal end of the lead towards an area where mechanical and electrical connection with the electrode may be formed, for example by an internal clip actuated by an external control (e.g., a button, lever, or other means of controlling a connection). An exemplary embodiment of the lead connector with a funnel end 71 is shown in FIG. 3C . The funnel 71 may ease insertion of the proximal end of the lead (arrow pointing where lead end would be inserted). The lead connector 30 may include a button 73 located on a top portion of the lead connector 30 , which is a non-limiting example of a mechanism by which the actual connection to the lead (internal, not shown) may be made/controlled. The patient cable 50 may be attached to the lead connector 50 in any appropriate manner and may allow for easy connection to the other components such as the simulator pod 40 . The lead connector 30 may eliminate the need for a separate tool. It may allow a one-handed mechanism for the clinician and/or patient, including, without limitation it may include a push mechanism. The lead connector 30 may be of any appropriate configuration. By way of a non-limiting example, the lead connector 30 may include plastic unit (e.g., manufactured by insert molding) with an insulation displacement connector (IDC) mechanism that strips the insulation from the lead 20 in order to make electrical contact. The lead 20 may be placed in a slot 62 with a contact strip with micro-structured barbs that hold the lead 20 in place until the IDC mechanism is implemented with a one-handed push mechanism. The lead connector 30 may also be employed for each detachment from (e.g., magnet, spring or other mechanism) and re-attachment. On the side of the lead connector 30 a breakaway mechanism 54 may be utilized. The breakaway mechanism 54 may include a connector that allows for quick detachment and easy re-attachment (e.g., magnet or spring-loaded mechanism). However, the present teachings are not limited to this configuration. The breakaway mechanism 54 may be operatively attached with the patient cable 50 , i.e., the portion of the lead 20 between the lead insertion site and the stimulator pod 40 . This may enable mechanical and/or electrical connection between the lead 20 and patient cable 50 and/or stimulator pod 40 . The breakaway mechanism 54 may be of any appropriate configuration that applies a predetermined force between a connection point or connection points between the lead connector 30 and patient cable 50 , between portions of the patient cables 50 and/or between the patient cable 50 and stimulator pod 40 . The breakaway mechanism 54 may be configured such that when a predetermined force is applied to the patient cable 50 it becomes dislodged from either of the lead connector 30 , another portion of the patient cable 50 and/or the stimulator pod 40 . The breakaway mechanism 54 may comprise a mechanical connection, electrical connection, a magnetic connection or any combination of such (a detachable and re-attachable connection), including, without limitation a hook and loop system similar to Velcro. These may operatively interact to provide a predetermined holding force so that when an amount of force exceeding this predetermined holding force the breakaway connector 54 releases. The present teachings are not limited to a specific configuration. The breakaway mechanism 54 may use insert molded Neodymium magnets by way of a non-limiting example. In other embodiments, a different permanent magnet may be utilized, such as a Samarium Cobalt, Alnico, Ceramic, Ferrite, or other rare earth magnets. In addition or in the alternative, a spring-loaded (or any biasing member) conductive pin (including, without limitation a gold, gold plated, metallic, or any other conductive material pin) connector may be located on the patient cable 50 and a mating conductive element configured to operatively engage with the conductive pin may be located on the lead connector 30 body. The conductive pin may be formed of any conductive material, including, without limitation being a generally flat gold plated contact. The conductive pin may be of any configuration and may adjust position relative to the mating conductive element. This may provide the predetermined holding force noted above. The present teachings, however, are not limited to this configuration. Any configuration of biasing member may be utilized to apply a predetermined force between the lead connector 30 and patient cable 50 (or in the alternative or in addition between portions of the patient cable 50 and/or between the patient cable 50 and stimulator pod 40 ). The lead connector 30 may eliminate the need for a separate tool—it may utilize a one-handed push mechanism. Further still, the lead connector 30 may include the breakaway mechanism 54 of any appropriate embodiment between the patient cable 50 and/or between the patient cable 50 and the stimulator pod 54 . Further still, any number of breakaway mechanism 54 may be utilized, e.g., one, two, three, etc. Each such breakaway mechanism 54 may be positioned on a different portion of the system, e.g., on the lead connector 30 , on the patient cable 50 (any number may be utilized) and/or on the stimulator pod 40 . Multiple breakaway mechanism 54 may be utilized to ensure that the break away occurs regardless of where the force is applied. The lead connector 30 may be configured to enable the adhesive bandage 22 to remain secure during use (e.g. locking out water and/or contaminants) while also enabling safe and easy removal. The lead connector 30 and adhesive bandage 22 may configured to allow change, application, and/or re-application of the adhesive bandage 22 while minimizing risk of displacing or dislodging the lead 20 , lead connector 30 , and/or any other system components. The lead connector 30 may mate with the adhesive bandage 22 to eliminate the need for multiple tapes and minimize the fear of lead dislodgement while performing bandage replacement. Further, the overall system may have a lower profile, including, by way of a non-limiting example having a 30% lower profile. For example, the lead connector 30 may have a low profile that may help reduce the likelihood of a patient “snagging” or inadvertently catching the lead connector 30 on an item. Having the low profile may reduce the chance of this occurring. The lead connector 30 may have a profile that when attached with the patient may extend from the patient slightly more, even with, or slightly below the adhesive bandage 22 . Additionally or alternatively, the connector 30 may have a rotating element, such as a knob, dial, spool or post. The rotating element may engage the lead 20 , mechanically and/or electrically, in order to assist in adjusting the tension of the detachable connection (e.g., the breakaway mechanism 54 ) having tension formed by the electrode 18 , the lead connector 30 and the patient cable 50 . The rotating element may include a predetermined tension release or recoil mechanism that responds to a disconnection force by releasing excess lead that is wound around the element. In the same manner, the lead connector 30 may accomplish this tension release by slider or other movement that need not be rotational in nature. As with the detachable aspects of the patient cable 50 connections, the tension release may occur at a force that is less than or equal to one-half the force required to dislodge or move the electrode 18 from its initial position. The lead connector 30 may be bifurcated or split into multiple divisions to receive a plurality of electrodes 20 . For example, multiple slots or funnels can connect multiple electrodes to a single stimulator pod 40 (or a plurality of stimulator pods 40 ) to enable therapeutic stimulation to be provided to separate parts of the body. In other embodiments, the connection between the lead connector 30 and patient cable 50 may be detachable—this detachability may be of any appropriate configuration, including, without limitation the break away mechanism 54 . The detachability may include, without limitation, magnets, such as insert molded neodymium magnets, that may be formed on the lead connector 50 and one or both ends of the patient cable 50 (if on both ends, the stimulator pod 40 would also have a detachable connection as described herein). Depending on the manufacturing process, the magnets, and how the magnets are fitted together, may allow for differentiating the points of connections. For example, the lead connector 30 may have a stepped connection port that fits with a correspondingly stepped connection on one of the patient cable, as illustrated in FIG. 4A . Alternatively, a circular magnet may sit on the top of the connector lead, also shown in FIG. 4B . A slight indentation or groove or other releasable force fitting could be provided to allow for the experience of a “snap-in” feel. In other embodiments, any mating shapes may be utilized such that the patient or clinician may insert one portion into another or otherwise engage the two components together—see for example FIG. 5 . Further, the present teachings are not limited to the shape and size of magnets shown and disclosed. Any appropriate shape or sized magnet may be utilized in these embodiments. The shape and size of the magnets may be the same, mating shape, or different shapes. Further, the breakaway mechanism 54 may not utilize magnets but may include mechanical connections of any type, shape and/or size that release from one another upon application of a specific amount of force. Regardless of configuration, the breakaway mechanism 54 may reduce the risk that force on the patient cable 50 is transferred to the lead 20 or more specifically to the electrode 18 inserted into the patient. The configuration may allow for easy attaching and easy re-attachment. In addition to or in place of magnets, a biasing fitting may be utilized—such as a spring-loaded member. The fitting is described generically so that it may be employed on any of the components, although particular utility is expected at the connection between the lead connector 30 and the patient cable 50 . End A has an inverted Y shape that mates with a corresponding shaped end B. Additional shapes, prongs or members may be included. The outermost arms C move, such as in a spring-loaded or magnetic fashion, to receive and release end A (single ended arrows indicate a preferred range of motion). Ends A and B may be fitted in the plane parallel to the double arrow and/or they may be dropped or snapped into place and then released in a direction that is different than, preferably including perpendicular to, the direction of release. In some embodiments, the break away mechanism 54 may be configured such that neither the stimulator pod 40 not the lead 20 (or more specifically the electrode 18 ) are displaced if unwanted force is applied to them or their connection(s). For example, the connection between the patient cable 50 and the stimulator pod 40 may be detachable upon application of a predetermined force. The predetermined force may be calculated to generally prevent movement of the electrode 18 once placed in the appropriate position within the patient. Alternatively, or in addition, the patient cable 50 may itself be detachable (e.g. in the middle so that it actually is a plurality of patient cables, e.g., 2 or more). The patient cable 50 may be detachable at any point between the lead 20 and the stimulator pod 40 , e.g., patient cable 50 may disconnect at either end. Further still, the predetermined detachable portion may be between the patient cable 50 and stimulator pod 40 , along any portion of the length of the patient cable 50 . For example, two or more patient cables 50 may be selectively attached at a detachment point to disconnect upon application of the predetermined force. Further, while the present disclosure notes that the portions are detachable, they may also be attachable. This may allow the system to serve as a failsafe mechanism to prevent damage and/or injury to the system, components, and/or the patient. The detachable portion may comprise the breakaway mechanism 54 described above or any other kind of appropriate detachable member. In addition to just safely detaching, the circuitry in any of the patient cable 50 , lead connector 30 , and/or stimulator pod 40 may prevent delivery of unwanted stimulation in the event of a disconnection during stimulation, such as when multiple leads and/or patient cables may be utilized. By way of a non-limiting example, the patient cable 50 may be a “smart cable” that has components in addition to a path for electrical conduction that minimizes the risk of the patient experiencing unwanted stimulation (e.g., minimizes or eliminates the potential for the patient to experience a shock) when the patient cable 50 is disconnected unexpectedly during use. For example, the patient cable 50 may, when disconnected from either of the lead connector 30 and/or the stimulator pod 40 prevent further stimulation. All of the above-mentioned connections rely on mated parts. In order to avoid improper installation, each of the mated pairs could be given a unique shape. Sensors or other circuitry may be employed at the connections points to better enhance the user alert feature described herein. Such sensors or circuitry could be inherent to the electrical signal delivering the stimulation, or separate signals could be established. The patient cable 50 may mechanically and/or electrically connect the lead connector 30 and controller pod 40 . Any durable, flexible material may be used for the patient cable 50 . Patient cable 50 may also deliver power to and/or from the connected elements, or independent power supplies may be provided. The power supply for the system 10 , and particular the stimulator pod 40 and controller pod 60 may be disposable or rechargeable, and any number of batteries or other power devices (e.g., capacitors, fuel cells, etc.) may be incorporated, depending upon the form factor and power requirements of the system. In the event a plurality of patient cables 50 is used to establish a connection between the electrode/lead connector 30 and the stimulator pod 40 , each segment of the patient cable 50 may rely on the quick release connections described above. In this manner, the risk of unintended force (e.g., snagging on clothing) repositioning or dislodging the electrode 18 is further minimized, particularly if the stimulator pod 40 cannot be placed proximate to the lead connector 30 . Utilizing a plurality of segments in the patient cable 50 also improves the overall adaptability of the system. The housing and/or materials selected for the lead connector 30 should be consistent with its design and purpose. At least portions of the lead connector 30 will be constructed from sufficiently conductive material to carry electrical pulses and signals from the stimulator pod 40 (such as via patient cable 50 ). Magnetic shielding may be selectively employed to minimize the creation of unwanted magnetic fields. In an embodiment depicted in FIG. 2A , the lead connector 30 may be attached to the body 12 . This attachment may be made by way of adhesives, straps or other means. In one embodiment, at least a portion of the lead connector 30 is engaged by the adhesive bandage 22 . The lead connector 30 may be sufficiently lightweight and/or located in sufficient proximity to other system components that are affixed to the body 12 , so that the lead connector 30 may simply move freely as part of the detachable connection having tension formed by the electrode 18 , the lead connector 30 and the patient cable 50 . As shown in FIG. 6 , a temporary tape strip 61 may be utilized to hold the lead connector 30 in place so as to operatively attach the break away mechanism 54 . The temporary tape strip 61 may not be utilized in some embodiments. The stimulator pod 40 may contain a programmable memory unit and circuitry necessary to deliver the therapeutic stimulation inherent to system 10 . Further, the stimulator pod 40 may be designed to eliminate the need for a separate return electrode. The stimulator pod 40 may also contain a graphical user interface to communicate with the user. The stimulator pod 40 may include an LED or other visual indicia to communicate actions, errors or other pertinent information about the operation of the system. The stimulator pod 40 may also allow for user and/or clinician adjustments to the operation of the system. Further still, the stimulator pod 40 may communicate with a controller unit, either via a physical or wireless connection. Cables, wires, Bluetooth and other wireless technologies are all expressly contemplated. In some embodiments, the controller pod 60 may either have or not have a user interface integrated with it and/or remote (e.g. wireless such as Bluetooth). The present teachings are not limited to any such configuration. The controller pod 60 may provide a more extensive graphical user interface, and it may be the primary means of initiating and altering the therapy, however, the present teachings are not limited to such. As with the stimulator pod 40 , controller pod 60 may communicate via physical wires/cables or wirelessly with the stimulator pod 40 (or pods, if multiple pods are included in the system) and the optional programmer unit 70 , described below. The controller pod 60 may be relatively larger than the stimulator pod 40 , although wireless connectivity may allow the user to carry the controller pod 60 in clothing and/or generally at a convenient distance and location in comparison to the electrode 18 and stimulator pod 40 . While the stimulator pod 40 and controller pod 60 may both have a low profile and lightweight features, the programmer unit 70 may be a fully capable computer that can transmit detailed therapeutic instructions/regimens, error logs, usage logs and/or other information generated by the system 10 . In some embodiments, the programmer unit 70 may remain in possession of the clinician, insofar as it enables a wider range of therapies, and the mobile and portable aspects of the other components in system 10 are inherent only to the user. The programmer unit 70 may communicate with the stimulator pod 40 directly or indirectly via the controller pod 60 . By way of example rather than limitation, the system 10 is expected to have particular utility in the treatment of post-stroke shoulder pain by way of percutaneous stimulation via a fine-wire lead in the deltoid muscle to stimulate branches of the axillary nerve. The therapy is delivered for a period of time, after which the lead is removed using gentle traction. The duration of daily therapy may range between 1 and 12 hours, with 6 hours as a preferred duration. The daily therapy may be administered over a period of days, weeks or even months, with 30 days anticipated to have the most benefit. The stimulation pulses and parameters may be varied, but the preferred range is less than 25 Hz, with some therapies particularly effective in the range bounded by separate lower and upper limits selected from: 1, 5, 10, 12, 15, 18 and 20, although other limits are contemplated. The amplitude is preferably centered at 20 mA, although any value between up to 50 mA or more may be useful. The pulse durations last anywhere from 5 microseconds to 200 microseconds or more, with minimal average pulse duration of 32 μs (range: 5 μs-75 μs); optimal average pulse duration of 70 μs (range: 10 μs-150 μs); and maximum tolerable average pulse duration of 114 μs (range: 25 μs-200 μs). Notably, tests have shown that electrical stimulation according to the system 10 for this purpose has both short term and long-term benefits that are not fully realized by the alternative treatment methods noted above. While post stroke shoulder pain application is described above, the present teachings are not limited to any specific treatment or indication. It may apply to any kind of treatment, including, without limitation post-surgical pain patients or any type of pain patients, especially chronic pain patients (e.g. neuropathic pain, headache, and/or back pain patients). Additional embodiments of a percutaneous stimulation system according the present teachings are described below. In the descriptions, all of the details and components may not be fully described or shown. Rather, the main features or components are described and, in some instances, differences with the above-described embodiment may be pointed out. Moreover, it should be appreciated that these additional embodiments may include elements or components utilized in the above-described embodiment although not shown or described. Thus, the descriptions of these additional embodiments are merely exemplary and not all-inclusive nor exclusive. Moreover, it should be appreciated that the features, components, elements and functionalities of the various embodiments may be combined or altered to achieve a desired percutaneous stimulation system without departing from the spirit and scope of the present invention. A lead connector 130 may be designed to couple to the percutaneous lead easily. In a non-limiting example, the lead may be inserted through an aperture 131 in the lead connector, and the lead may go through partially or completely through the aperture 131 . The aperture 131 may include a funnel shape where the lead is inserted to enable easy insertion into the aperture—See FIG. 12 . In another non-limiting example, the lead may be placed into a slot or channel in the lead connector 130 . In another non-limiting example, the lead connector may be composed of two or more components with the lead placed between and/or within the components, and the components may be secured together (e.g., slid together, snapped in place, twisted/screwed onto one another, etc.) to couple to the lead. In some embodiments, the lead connector 130 may enable easy one-handed insertion and coupling of the lead to the system while remaining mechanically and electrically secure and prevents the patient from decoupling the lead (or electrode) intentionally or unintentionally. The lead may be coupled to the lead connector electrically and mechanically. The mechanism by which the lead may be coupled mechanically to the lead connector 130 may be separate or the same as the mechanism by which the lead is coupled electrically to the lead connector 130 . The user may couple the lead to the lead connector 130 using a component including, but not limited to, a knob, button, switch, or dial. The lead connector 130 may be decoupled from the lead, and may allow the lead to be reconnected to the lead connector 130 at a different point along the lead (e.g., closer to or farther away from the stimulating portion of the lead or electrode). In a non-limiting example, the lead connector 130 may include a lock to prevent the patient from disconnecting the lead. The lock may be opened using, for example (but not limited to), a key, a tool (e.g., torque wrench), a code (e.g., combination) or without a tool. In another non-limiting example, the lead connector 130 may minimize or eliminate damages or changes to the lead's structure, enabling the lead to remain sufficiently intact to generally reduce the risk of the lead fracturing or breaking and enable current flow through the entire lead. A lead connector 230 may include a lead storage mechanism 233 to store a lead 220 (e.g., while the lead is coupled to the lead connector 230 ). This mechanism may reduce the excess length of lead 220 between the lead connector 230 and the point from which the lead 220 exits the body. This may reduce the risk of the lead 220 being caught on an object and being pulled and/or breaking. If the lead 220 is caught, for example, on an external object or from a body part, then the excess lead 220 stored on the mechanism may be released rather than dislodging or moving the lead 220 from the tissue, fracturing the lead 220 (inside or outside the body), and/or pulling the lead 220 out and decoupling from the lead connector 230 . In a non-limiting example, the mechanism 233 may be a spool around which the lead 220 is wound, either manually or automatically (e.g., using a spring). In another non-limiting example, the mechanism 233 may be located on the outside of the lead connector 230 or within the lead connector 230 —See FIGS. 13 and 14 . In addition, the lead connector 230 may be padded on one or more sides to provide comfort while wearing the lead connector 230 . A lead connector 330 may be designed to couple to the stimulator pod 40 easily, and may enable connection using a single hand. In a non-limiting example, the lead connector 330 may be connected to the stimulator pod 40 via a patient cable 350 . In a non-limiting example, the patient cable 350 may connect to the lead connector 330 through a connection 357 , such as by way of a non-limiting example a magnetic connection. It should be understood, however, that while a magnetic connection is described, the connection maybe any mechanical connection in addition to or alternatively to the magnetic connection. The connection 357 may be oriented at various angles with respect to the surface of the skin. In a non-limiting example, the connection 357 is oriented generally perpendicular to the skin. In another non-limiting example, the connection 357 is generally parallel to the surface of the skin. In yet another embodiment, the connection 357 may be easy for the user to make (e.g., does not require great dexterity, may be connected even without looking at the connectors) and strong enough to prevent inadvertent disconnection (e.g., due to common body movements or small forces, etc.) while disconnecting when subjected to stronger forces that may dislodge the lead (e.g., from external objects or body parts pulling or tugging on the lead connector or stimulator attached to the lead connector). The connection 357 may prevent the lead 320 from dislodging or fracturing by disconnecting the lead connector 330 and cable when the patient cable 350 is pulled rather than transmitting the force along the lead 320 —See FIGS. 15 and 16 . In some embodiments, the connector 357 may include two portions a positive 357 a and negative 357 b portion of a magnet that attract to one another at a predetermine force. It should be understood that the positive portion may be on either side 357 a or 357 b and the negative portion may be on either side 357 a and 357 b . Further still one portion may be a magnet ( 357 a or 357 b ) and the other side may be a material attracted by the magnet ( 357 a or 357 b ). In a non-limiting example, the magnetic connectors 330 may be structured such that the surrounding magnetic field is reduced and avoids interfering with objects placed near the magnetic connectors (e.g., credit cards, cell phones). Further still, the lead 320 may connect directly to the stimulator pod 40 (i.e., lead connector may be built into or integrally with the stimulator pod). The stimulator pod may be placed directly over or adjacent to the lead exit site to protect the exit site. There may be a clear window through which the lead exit site can be monitored for safety (e.g., infections, irritation). In another non-limiting example, the patient cable 450 may connect to the lead connector 430 using a jack 457 b and plug 457 a , and the jack 457 b may be located on the patient cable 450 and oriented at an angle (such as 90 degrees) to the patient cable 450 . This jack 457 b may be connected to the plug 457 a on the lead connector 430 using a downward force, enabling connection using a single hand. The very small distances between the magnetic armature of the plug 457 a and the permanent magnet structure of the lead connector 430 means that the residual field outside the lead connector 430 is very small—see FIG. 16 . As shown in FIG. 17 , a patient cable 550 may attach to the stimulator and stored or organized (e.g., wound, coiled, wrapped around) to reduce the length of the patient cable 550 (or lead 520 ) that may become caught, for example, on an external object or a body part. In a non-limiting example, the excess patient cable 550 may be stored in a storage device 551 attached to the cable 550 , on the lead connector 530 , and/or on the stimulator pod 540 . In a non-limiting example, the storage device 551 is a spool around which the patient cable 550 may be wound manually or automatically (e.g., via a spring). In an embodiment, the patient cable 550 may be coiled or wound around a spool on the stimulator pod 540 , and forces on the patient cable 550 cause the patient cable 550 to be uncoiled from the spool rather than disconnect from the stimulator pod 540 , transmit the force to the lead connector 530 , and/or patient cable 550 —See FIG. 17 . The stimulation system may contain patient cable that attach to the stimulator pod available in multiple lengths. In a non-limiting example, the patient cable with the shortest length that enables connection between the stimulator pod and the lead connector may be selected to reduce the risk of the patient cable catching on an object or body part and disconnecting the system, dislodge the lead, and/or fracture the lead. As shown in FIG. 18 , two or more patient cable 650 may be used to connect the stimulator pod 640 to the lead connector 630 . The use of more than one patient cable 650 to connect to the stimulator pod 640 may enable more control of the total length of cabling between the lead connector 630 and stimulator pod 640 (e.g., compared to the use of a single cable with a fixed length). In a non-limiting example, each individual patient cable 650 may be short (e.g., <1-2 inches), which may enable more precise control over the total length of the multiple cables connected together. In another non-limiting example, patient cables 650 may be available in different lengths. In a non-limiting example, multiple patient cable 650 may be connected together, and the minimum number of cables are used to connect the lead connector 630 to the stimulator pod 640 to minimize the total length of cable, thus reducing the risk of the cables catching or snagging (e.g., on an external object or a body part)—See FIG. 17 . Each of the patient cables 650 may be attached utilizing a breakaway mechanism 654 of any configuration, such as that described above. Each patient cable 650 may include a breakaway mechanism 654 attached to each end thereof. The breakaway mechanism 654 may connect to one another and/or the lead connector 630 and/or the stimulator pod 640 such that they remain connected upon applicable of a predetermined force. If the force applied exceeds this predetermined force any of or a plurality of the breakaway connectors 654 may become disconnected. This prevents the electrode from moving from within the patient. The breakaway connectors 654 may also be easy to attach once they have become disconnected. The breakaway connector 654 may utilize magnets, bayonet attachment, biasing force, friction fit, etc. to connect together. Any appropriate configuration may be utilized. In some embodiments, the stimulator pod may enable coordinated stimulation across two or more stimulator pods. In the alternative or in addition, the controller pod and/or programmer unit may enable coordinated stimulation across two or more stimulator pods. Coordinated stimulation may enable stimulation across multiple stimulator pods to start and stop in a coordinated manner to avoid asynchronous activation of muscle on opposite sides of the body (e.g., the back or torso), which may cause loss of balance or discomfort. Control over stimulation across multiple stimulator pods may also prevent synchronized stimulation, for example, to avoid activation of opposing muscles (e.g., biceps and triceps), which may cause discomfort. In a non-limiting example, one of the stimulator pods, controller pod and/or programmer unit may communicate with other stimulator pods directly. In another non-limiting example, each stimulator pods may be connected to a central controlling unit, which may be another stimulator pod or may be a non-stimulating control unit. In a non-limiting example, communication among stimulator pods and/or control units (controller pod or programmer unit) may be wireless (e.g., via Bluetooth, WI-Fi) or wired (e.g., cables). The stimulator pod may provide simple programming of stimulation intensity by controlling stimulation amplitude and pulse duration with a single programmable parameter for intensity. Stimulation intensity is determined by multiple parameters, including (but not limited to) stimulation amplitude and pulse duration. For example, stimulation intensity may be increased by increasing stimulation amplitude, pulse duration, or a combination of the two. Controlling multiple parameters such as stimulation amplitude and pulse duration using a single parameter may reduce the complexity of the procedure to program stimulation parameters by reducing the number of parameters that can be changed from 2 or more to 1. As a non-limiting example, the minimum of the stimulation intensity parameter (e.g., 0) may set the stimulation amplitude and pulse duration to their lowest values (e.g., 0.2 mA and 10 microseconds). As another non-limiting example, increasing the stimulation intensity parameter may change the stimulation amplitude, the pulse duration, or both. In yet another embodiment, increasing the stimulation intensity parameter from the minimum value may first increase the stimulation amplitude while keeping the pulse duration at a minimum until the maximum value of the stimulation amplitude (e.g., 20-30 mA) is reached. Then, continuing to increase the stimulation intensity parameter may keep the stimulation amplitude fixed at the maximum value while increasing the pulse duration until the maximum value of the pulse duration is reached. In these embodiments, stimulation intensity is simple to program and may be increased while keeping pulse duration as low as possible. This keeps the stimulation charge required to activate nerve fibers as low as possible and increases the ability to selectivity stimulation large diameter fibers over small diameter fibers. In another non-limiting example, increasing the stimulation intensity parameter from the minimum value may first increase the stimulation amplitude while keeping stimulation amplitude at a minimum. Then, continuing to increase the stimulation intensity parameter beyond the maximum value of pulse duration (e.g., 200 microseconds) may keep the pulse duration fixed at the maximum value while increasing the amplitude until the maximum value of the stimulation amplitude is reached. In this example, stimulation intensity increases while keeping stimulation amplitude as low as possible, which keeps the power consumption of the pulse as low as possible for a given charge per pulse. Left column of FIG. 19 is the first example given, keeping pulse duration low. The right column of FIG. 19 is the second example, keeping stimulation amplitude low. In another non-limiting example, a lead connector may be attached to the lead prior to or after insertion of an introducer system, enabling stimulation through the lead tip during the lead placement procedure. In one embodiment, the connector may be attached to the lead by dropping the lead into a slot or hole on the block and closing a flap which implements an insulation displacement connection (e.g., cutting through the insulative material aside to form a connection with the conductive lead wire). This lead connector may improve the speed and ease of lead connection because it can be attached without the use of tools (e.g., no wire cutters, scissors, and screwdrivers). For example, in this embodiment, the lead may be placed into a slot in a lead connector block and secured using a lockable, reversible one-handed mechanism to displace the insulation on the lead body. The insulation displacement mechanism inside the lead connector may also cut the lead distal to the electrical connection. Once the connection has been made and the excess lead is trimmed, a lock (e.g., sliding, twisting, button press) may ensure that the flap on the block cannot be reopened accidentally. This feature prevents loss of connection between the lead connector and lead, which would result in loss of therapeutic benefit. The lead connector may mate with another lead connector (e.g., patient cable or plug to the stimulator pod) to complete the circuit from the stimulator pod to the lead tip electrode. In one embodiment, the connection between the two lead connectors may be magnetic. In this case, the shape of the lead connectors will prevent improper alignment of the lead connector (e.g., lead connectors that only fit together in one orientation). The magnetic connection may be used for both temporary and permanent stimulation delivery (e.g., during lead placement procedure or during patient's home use of the therapy). After obtaining proper lead placement location, the lead connector block may be removed and replaced following removal of the introducer system needle(s) and sheath(s). In one embodiment, the connection may be deactivated by pressing or sliding open the slot that contains the lead. In this example, the lead connector block may be removed or cut off prior to removal of the introducer and then quickly re-attached to a more proximal location on the lead. Following removal of the introducer, the lead may be placed in the slot and connected with a one-touch mechanism (e.g., pressing, sliding) and then the lead connector may be attached to the stimulator cable. The magnetic connection may act as a quick-release connection that will prevent accidental lead (or electrode) dislodgement due to a pulled lead and/or patient cable. Instead of transferring force to the lead exit site and lead, any forces on the patient cable will be discharged due to the breaking of the magnetic connection between the patient cable and lead connector block. If desired by the clinician, a permanent connection may be made by locking the two-connector pieces together using a press button lock (or any other suitable lock). In addition to mating with the lead connector block, in another embodiment, the magnetic cable connector for the stimulator pod may also mate with an identical version of the lead connector block, which is connected to the test stimulator via a cable. In another embodiment, the magnetic cable connector originating from the stimulator pod may be bifurcated to connect with multiple lead connector blocks (e.g., to enable stimulation of two leads with one stimulator). A battery-operated, body-worn stimulator pod may generate electrical current that may be administered via the lead and/or introducer. In one embodiment, the stimulator pod is a small pod (e.g., with rounded contours and of minimal profile height) that is worn on the body via a gel patch electrode that serves as the return electrode and is connected with two snaps that also provide electrical connection. In one embodiment, the stimulating pod has a minimal user interfaces (e.g., a press button start/stop, LED lights and a speaker or buzzer) to provide critical feedback to the patient. For example, the lights may blink or light up (e.g., different colors or different flashing patterns) if the battery is low or if there is a problem with stimulation. This important feedback will alert the patient or clinician to address any issues, such as battery failure, gel pad detachment, or open connection. In the non-limiting example with a magnetic lead connector, it is important that the stimulator pod produces an alert if the quick-release cable is accidentally dislodged without the patient's knowledge. Additionally, lead errors that cause stimulation to stop due to, for example, high electrode impedance issues (e.g., due to lost connection between skin and return electrode), and can impact therapy usage time and therapeutic benefit received by the patient and the audible or visible alert of the stimulating pod prevents this. Further, in one embodiment, the stimulator memory will generate an activity log for documenting usage of the stimulator and errors during therapy. The stimulator log may include a list of errors that occurred, along with timestamps of the time that errors occurred, a history of usage time, including amplitude and stimulation parameter settings used. These features are important to ensure that patients are able to effectively use the stimulation and that clinicians can effectively monitor their stimulation usage. Exemplary embodiments of the IDC are depicted in FIGS. 20 and 21 . An IDC 705 shown in FIG. 20 may include a drawer type mechanism or disc 708 that is insertable into the body of the IDC 705 and removable therefrom. A slot 710 of any appropriate shape and size to firmly hold or engage the lead 720 may be positioned within the disc 708 . A user may push the disc 708 to rotate such and move the lead 720 fully inside the IDC 705 . The IDC may be integral with or attached to the lead connector. Barbs (not shown) may be included in the interior of the IDC 705 if necessary to remove insulation from the lead 720 to expose the underlying wire. In another embodiment shown in FIG. 21 , an IDC 805 may have a generally cylindrical shape. The IDC may include an aperture, slot or opening 807 into which the lead 820 may be inserted. The IDC may include an actuating lever to rotate the IDC until the lead 720 is fully inside the IDC. Barbs (not shown) may be included in the interior of the IDC 805 if necessary to remove insulation from the lead 820 to expose the underlying wire. An additional embodiment of a breakaway mechanism 954 is shown in FIGS. 22-25 . In FIG. 22 , a portion of the breakaway mechanism 954 is shown as a receptacle portion 956 . The receptacle portion 956 may include a magnet 958 of any appropriate embodiment that includes a contact point 959 . The receptacle portion 956 may include an iron magnetic stator 960 , which may act as a pathway keeper. FIG. 23 depicts a mating portion of the breakaway mechanism 954 , which is a plug 962 . The plug 962 may include an iron magnetic keeper path 964 and a contact 966 . The patient cable 950 may be operatively attached with the plug 962 . As shown in FIG. 24 , the breakaway mechanism 954 may include a spring loaded plunger mechanism 974 . The plunger mechanism 974 utilizes a pair of biasing member 977 that may push plungers 975 toward each other as the plug 962 is inserted into the receptacle 956 . This may secure the breakaway mechanism 954 together. The force utilized to keep the breakaway mechanism 954 together is defined such that any amount of force applied to the system that exceeds such force will cause the plug 962 to separate from the receptacle 956 , e.g., if there is a force applied to the patient cable 950 because it snags on something. This will generally protect the system. In particular, it generally prevents the lead and/or electrode from becoming disengaged or moved from their intended position. Although the embodiments of the present teachings have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present teachings are not to be limited to just the embodiments disclosed, but that the present teachings described herein is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter.

Neurostimulation assemblies, systems, and methods make possible the providing of short-term therapy or diagnostic testing by providing electrical connections between muscles and/or nerves inside the body and stimulus generators and/or recording instruments mounted on the surface of the skin or carried outside the body. The assembly affords maximum patient mobility and comfort through differentiated components having minimal profiles and connected by way of detachable and adjustable connections.

RELATED APPLICATIONS [0001] This is a divisional application of U.S. application Ser. No. 12/812,615 and claims rights under 35 USC §119(e) from U.S. Application Ser. No, 61/113,377 filed Nov. 11, 2008, the contents of which are incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention relates to optical multiplexers and demultiplexers and more particularly to a compact optical multiplexer/demultiplexer for multiplexing and demultiplexing beams of light having different wavelengths or frequencies. BACKGROUND OF THE INVENTION [0003] There is a common problem in telecommunications in which optical fibers have multiple communications channels embedded in it in terms of different colors of light which are transmitting different streams of information. One of the problems is to split out these channels so that they can be separately processed, for instance to adjust intensity, polarization and dispersion or color spread. [0004] It is also often important in optical communications to be able to modify each of the individual wavelengths of light differently and then be able to combine the processed channels so as to recombine them back into a single fiber. Thus, it is important to break out from a single fiber the individual spatial components, to process them and to inject them back into a single fiber. [0005] While the telecommunications problem described above is important, it is also important to be able to use such a multiplexer for instance to be able to generate high energy laser beams. Presently fiber lasers exist which can produce hundreds of watts of light within an individual glass fiber. Unfortunately, these intensity levels are not enough for some military and industrial applications. The problem then becomes how to be able to utilize fiber lasers and to provide a combined output to be able to dramatically increase the energy delivered by the system. [0006] There is also a problem with respect to infrared laser countermeasure devices it which laser beams modulated to countermeasure for instance an incoming missile, require a considerable amount of energy on target to be able to robustly provide the countermeasuring function. [0007] One type of laser used in infrared, countermeasures is the so-called quantum cascade or semiconductor laser. It is highly desirable for these applications to achieve higher laser powers in a low-divergence beam. It is therefore important to be able to augment or combine semiconductor laser outputs to provide for instance a 10 watt modulated beam on target. [0008] Up to this juncture, there has been no effective way to combine the outputs of fiber lasers or semiconductor lasers to be able to significantly increase the power emitted in a laser beam. [0009] Moreover, it is important in the military context to be able to provide the power amplification modules in a sufficiently small form, to be able to be for instance carried by a missile, carried in a DIRCM head on the belly of an aircraft, or to provide small enough packaging to be able to be readily used in any applications where space is at a premium. [0010] By way of further background, optical multiplexer/demultiplexers are optical instruments that separate out the wavelength spectral components contained in a single input light source. Operated in reverse, the same instrument combines multiple light sources of single color light into a single output beam. In other terminology, a optical multiplexer/demultiplexer demultiplexes the wavelengths in the forward direction and multiplexes the several beams in the reverse direction. In the field of fiber optics communication, for example, the communication bandwidth of a single fiber has been greatly increased using wavelength division multiplexing, or WDM, techniques. Similarly, the measurement and control the properties of individual wavelengths propagating in the fiber, which is critical to the performance and operation of these WDM systems, is performed by demultiplexing the wavelengths into individual control channels. [0011] Grating based optical multiplexer/demultiplexers are generally made up of five functional components; an input point source or linear slit, a collimating optic, the grating, an imaging optic, and one or more receiving components in the output image. When operated as a multiplexer, the one or more receiving components are replaced by narrowband light sources and the input source is replaced by a single receiving component. [0012] Light emerging from the input source is collimated by the collimating optic so that a planar wavefront impinges on the (plane) grating. The grating breaks the single input beam up into multiple beams, with each wavelength propagating in a unique direction. The imaging optic collects these diffracted beams and focuses them into spots at an output plane, where each spot corresponds to a wavelength in the source. The spot corresponding to any single wavelength has finite size, said size primarily being a function of the optical system and the grating. Operated as a multiplexer, the multiple narrowband sources (fiber laser outputs, for example) are positioned in the “output” plane at positions that correspond to their central wavelengths. The imaging optic now functions as a collimator, bringing the multiple wavelength collimated beams together on the grating, impinging on the grating at a angle determined by the location of the source in the output plane. The grating redirects each beam through a unique angle, which angle ideally brings each beam to be coaxial with all the other beams. Finally the collimating optic brings all the parallel collimated beams into a common focal spot at which is located a receiving element. [0013] One object of the present invention is to simplify the optical configuration of optical multiplexer/demultiplexers by reducing the number of independent optical elements needed. It is another object of this invention to provide a physically large output spectral field while maintaining a compact, easy to package form factor. Yet another object of this invention is to provide a optical multiplexer/demultiplexer using a grating in a near-Littrow configuration. [0014] In an alternative configuration, it is an object of this invention to provide improved spectral resolution using only spherical reflective optics. [0015] In another configuration, it is an object of this invention to provide wavelength multiplexer in which multiple independent light sources can be combined into a single coincident output beam. [0016] In yet another configuration it is an object of this invention to provide a region of space in which individual spectral components from the source are physically accessible. [0017] A further object of this configuration is to enable the manipulation or filtering of individual spectral components. [0018] Yet another object of this invention is to recombine filtered spectral components back into a single beam similar in form to the source. [0019] It is a still further object of the subject invention to provide a compact optical multiplexer/demultiplexer for use as a multiplexer/demultiplexer in a telecommunications mode and to be able to combine laser beams of different wavelengths or frequencies to provide highly intense laser beams. SUMMARY OF INVENTION [0020] The present invention relates to an apparatus and method for spectrally multiplexing and demultiplexing beams of light. More specifically the invention relates to multiplexing or demultiplexing beams of light of different wavelengths or frequencies from multiple light sources, typically fiber lasers. This permits various applications both in telecommunications and in combining laser outputs having different frequencies to provide a high energy combined beam both as a weapon and for countermeasure purposes. [0021] In his invention, compact optical multiplexer/demultiplexer is created using two spherical, reflective optical elements in combination with a diffraction grating operating in a near Littrow configuration to permit light to come in and go out from a common input direction. The telecentricity of the optical design in the conjugate space to the input fiber also permits use of parallel optical fibers to input and output light as opposed to orienting individual fibers in different directions depending on wavelength or frequency in one embodiment, a source of light such as an optical fiber is placed at the focus of a collimator. The collimator collimates the light and directs it to the grating. The dispersed light from the grating is collected by the imaging optics and focused into the output plane. [0022] The pair of reflective optical elements is used as both the collimator and the imaging optics for the optical multiplexer/demultiplexer and results in a compact design making the focal length minimized over a single lens system for instance involving a 3+ foot round-trip optical path within a compact 6×8 inch optical footprint. One reflector is a multisection device having a parabolic collimator surface at its outer edge to collimate light towards a grating. Next to the collimator is a reflective object on the multisection deflector to reflect refracted light from the grating to an imaging optic. Light from this imaging optic is reflected by another section of the multisection reflector to an output plane. Thus what is provided is a optical multiplexer/demultiplexer with only two reflective elements. [0023] The two elements operating as the imager act as a telephoto lens, viz., have a physical back focal distance shorter than the optical focal length. A third, refractive element, located near the source, can optionally be added to change the input F-number and provide partial compensation for residual spherical aberrations in the optical system. The output of the optical multiplexer/demultiplexer is a continuous distribution of light in which the spectral distribution of energy in the source is mapped into spatial location. [0024] Note that although this invention has application for multiplexing as well as demultiplexing light beams, for clarity and brevity the names for the optical elements throughout this specification will relate to the demultiplexing application. The collimator is the only optical element between the source and the grating but the imaging optics comprise two elements—a region of the collimator and a second reflective optic. [0025] In another configuration the optical multiplexer/demultiplexer apparatus can be configured to multiplex multiple narrowband fiber sources positioned in the output plane at precise locations determined by their wavelengths. [0026] In a third configuration, the optical multiplexer/demultiplexer can be used to demultiplex (separate), manipulate individually, and multiplex (recombine) into one beam the various spectral components in the source. In this application the distributed image at the output of the optical multiplexer/demultiplexer is directed through a multi-channel filtering (or manipulating) element. The filtered light is then redirected back into the optical multiplexer/demultiplexer, each spectral component generally parallel to itself, so that the optical multiplexer/demultiplexer, acting in reverse, now recombines the disparate spectral components into a single beam. The single beam is formed in the input plane, displaced laterally from the input aperture. BRIEF DESCRIPTION OF THE DRAWINGS [0027] These and other features of the subject invention will be better understood in connection with the Detailed Description, in conjunction with the Drawings, of which: [0028] FIG. 1 shows a prior art optical multiplexer/demultiplexer in the Ebert-Fastie configuration; [0029] FIG. 2 shows a prior art optical multiplexer/demultiplexer in the Czerny-Turner configuration; [0030] FIGS. 3A , 3 B, and 3 C show applications of the compact optical multiplexer/demultiplexer functioning either as a multiplexer for fiber lasers to provide a high power collimated beam, to combine the modulated outputs of semiconductor milliwatt lasers to provide a modulated high power infrared countermeasure beam and to provide a multiplexer/demultiplexer module for correcting the individual color channels in a single fiber input beam to process the individual color channels and to output corrected color channels ported to a single output fiber; [0031] FIGS. 4A and 4B are schematic diagrams of a demultiplexer embodiment of the invention as laid out in the x-y plane, with 4 B showing details of the entrance aperture region; [0032] FIG. 5 schematically shows two means for injecting light into the optical multiplexer/demultiplexer of FIG. 4A ; [0033] FIG. 6 is an optical design diagram of a preferred embodiment of the demultiplexer of FIG. 4A showing the parallel focused multispectral beams impinging on the output plane to establish telecentricity; [0034] FIG. 7 is the optical design diagram of an alternative embodiment of the demultiplexer of FIG. 4A showing a segmented reflective optical element having a parabolic section for collimating light onto the grating and aspheric focusing elements; [0035] FIG. 8 is a perspective view of a preferred demultiplexer embodiment of the optical multiplexer/demultiplexer; [0036] FIG. 9 is a diagrammatic illustration of the spherical surface configuration of the reflective element of FIG. 8 ; [0037] FIG. 10 illustrates how the optical elements may be provided above and below a plane to permit light exiting or entering the device to be conveniently physically displaced so that exiting light can be processed and injected back into the subject multiplexer/demultiplexer; [0038] FIG. 11 is a schematic view of the arrangement of optical elements to permit the operation of FIG. 10 by locating these elements in the region around the input aperture of the optical multiplexer/demultiplexer function as a demultiplexer in a plane containing the z-axis in which the optical elements can be configured to permit optical processing such that multispectral light at the output plane an be processed and injected back into the subject optical multiplexer/demultiplexer; [0039] FIG. 12 presents a schematic view of the subject optical multiplexer/demultiplexer operating as a multiplexer; and, [0040] FIG. 13 is a schematic drawing of a multi-fiber v-block used to inject multispectral light into the multiplexer of FIG. 12 . DETAILED DESCRIPTION [0041] As will be discussed, a spectrometer operating at Littrow will spread out the various wavelengths in a much shorter distance as compared with conventional non Littrow spectrometers. While one can go far enough away from a grating to establish sufficient color separation, the length of the device is prohibitive in many applications. Optics associated with such gratings are said to have a focal length dependant on color separation often in excess of one meter. A key advantage to the subject multiplexer/demultiplexer operating at Littrow is that the color separation is so great, the effective focal length can be reduced substantially to inches, making the subject multiplexer/demultiplexer device exceptionally compact. [0042] Operation at Littrow refers to the directions of the collimated beams of the grating and the general direction of the diffracted light being equal. To the extent that these directions are nearly the same establishes the greater dispersion angle and the ability to make the device compact. [0043] More specifically, the importance of the Littrow configuration is that it is the entire purpose of the diffraction grating to split colors of light into different output angles. If all the light comes in one direction, and if all the colors come in collimated with a single angle of incidence, the grating will split them into a rainbow in which each color comes off at a different angle. The degree of angular spread between the beams coming off of the grating creates dispersion. In general, to minimize the size and expense of optical multiplexer/demultiplexers, one seeks as maximize the dispersion of the diffraction grating in the utilized geometry. [0044] If one uses a diffraction grating at Littrow with the diffracted angle equal to the indident angle, one also maximizes the dispersion of light. The spread is greatest if one is running near a Littrow configuration. Generally in order to get the beams in and out of the grating with multiple colors one must to a certain extent move to a near-Littrow configuration. [0045] Several different collimating/imaging optic configurations have been developed over the years to maximize performance while optimizing other figures of merit. For example, the Ebert-Fastie configuration shown in FIG. 1 uses a single spherical mirror 10 as both collimator and imager, optimizing cost. Here a diverging beam through an entrance slit 12 is collimated by minor 10 onto grating 16 . The diffracted light from grating 16 is focused by mirror 10 out through exit slit 14 . This configuration is a non Littrow configuration and suffers from significant optical aberrations because the single optic must be used significantly off-axis. [0046] It is noted that in the prior art device of FIG. 1 , a common mirror 10 has a spherical surface in which light which is effectively a point source or a line source, is diverging and is required to be collimated effectively by that minor. A spherical mirror does not collimate a beam well. One therefore needs a parabolic mirror for a single mirror to give a very high quality collimated beam. [0047] Referring to FIG. 2 , a Czemy-Turner configuration is shown which spherical mirror 10 of FIG. 1 is broken up into two separate mirrors, a collimator mirror 18 and a imaging mirror 20 which again provides a non-Littrow configuration. The choice of the shape of these mirrors is optimized so that one can optimize the collimating mirror to give a high quality collimated beam incident on grating 16 . On the other hand imaging mirror 20 collimates the beam from the grating out through exit slit 14 , with the two mirrors being oriented in the right directions to give the best performance out of the two elements. [0048] While there is a certain amount of performance that one can achieve out of these two elements, the optical multiplexer/demultiplexer formed thereby is exceedingly large due to the non-Littrow operation. [0049] Note, the Czerny-Turner configuration shown in FIG. 2 uses two independent spherical optics for the collimator and imager. This configuration is more expensive but has lower aberrations. Optical Multiplexer/Demultiplexer Applications [0050] Referring now to FIGS. 3A , 3 B and 3 C, shown are a number of applications for the subject optical multiplexer/demultiplexer operating either as an optical multiplexer or a combined optical demultiplexer and multiplexer. [0051] it is the purpose of the subject optical multiplexer/demultiplexer, to multiplex or combine laser inputs of a number of colors, frequencies or wavelengths and combine them into an output beam in which the energy in the output beam is, to a first approximation, the sum of the energies in the input beams. What the subject optical multiplexer/demultiplexer is able to accomplish is to be able to provide high or low power collimated output beams than that achievable with individual lasers that do not provide an adequate laser power for a given application. [0052] Nowhere is this more important than the utilization of fiber lasers which in general are capable of high output powers of hundreds of watts, or higher. It is important to be able to combine the outputs of these lasers and sum them in a way to produce a much higher output collimated beam. [0053] To this end and as shown in FIG. 3A , a number of fiber lasers 30 , each operating at a different color or frequency have their beams 32 applied to an optical multiplexing device 34 , the purpose of which is to take the separately colored laser beams and combine them into a collimated high energy beam 36 which is redirected for instance by a mirror 38 to an aiming head 40 which aims the beam 42 towards a target 44 to be able to destroy the target or at least a portion thereof. The wavelengths of the individual lasers are chosen appropriately to allow the optical multiplexing device 34 to combine them into a coboresighted output beam. [0054] It will be appreciated that there is a limit to the power output of a single fiber laser, and while these fiber lasers are efficient providers of collimated light, it is important to have methods to provide for the high intensity beams required in certain military applications. [0055] Referring to FIG. 3B it is also possible in an infrared countermeasure system to provide semiconductor milliwatt lasers 50 which are modulated by an optical modulation 52 to provide modulated differently colored beams 54 towards the same type of optical multiplexer that is shown by reference character 34 in FIG. 3A . [0056] Here, the output is a modulated collimated beam 56 which is directed by a directed infrared countermeasure (DIRCM) head 58 towards a target 60 , with the modulated radiation causing the seeker in the missile head of missile 60 to direct the missile away from its intended target as illustrated by dotted arrow 62 . [0057] The above shows a system by which lasers of different colors can have their outputs combined to provide a collimated beam which is highly intense and is the sum of the output powers of the input lasers. [0058] Referring now to FIG. 3C , the subject optical multiplexer/demultiplexer may be utilized as both a multiplexer and a demultiplexer without alteration of its optical components. Here an optical multiplexer/demultiplexer 64 is provided to take an input beam 66 constituting the output from a single fiber carrying different colored channels. [0059] It is the purpose of the optical demultiplexer in one mode is to couple a number of demultiplexed beams 68 to a beam processing unit 70 , the purpose of which is to alter the characteristics of the individual beams to correct for intensity, polarization and dispersion or color spread. Such processors are known and include for instance the processors described in published US Patent Applications 2003/0067641 and 2002/0176645, incorporated herein by reference. The corrected or processed beams 72 comprising beams of different frequencies are redirected by mirrors 74 , 76 , 78 and 80 back into the self-same optical device, namely optical multiplexer/demultiplexer 64 . [0060] Using the same optical elements and configuration, the corrected beams, each of a different color, are combined by the multiplexer action of multiplexer/demultiplexer 64 such that they are recombined into a single collimated be 82 which may be coupled to a single optical fiber, with the characteristics of the individual beams corrected. [0061] Thus as can be seen, the subject optical multiplexer/demultiplexer can be utilized in applications where beams of multiple colors are to be combined, and wherein beams having information carried in multiple colors may be separated out for processing, followed by multiplexing back into a single beam. [0062] As to the optical multiplexer/demultiplexer design, and referring to FIG. 4A , a optical multiplexer/demultiplexer 80 has essentially two reflective elements 90 and 92 . [0063] Reflective element 90 collimates the diverging light from fiber 100 , with a portion 200 of reflective element 90 directing the collimated beam towards a grating 300 . [0064] Grating 300 disperses the incident beam and returns the diffracted beam as illustrated at 140 to a reflective surface 310 of reflector 90 . [0065] As will be described, the narrow angle α between the input and output beams to and from the grating is what makes the system near-Littrow, since the collimated incoming beam 130 incident in one direction is almost in the same direction as the outgoing dispersion 140 . [0066] The diffracted energy from grating 300 is focused by a combination of reflective surfaces 310 , 320 , and 330 , which focuses the energy onto a focal plane 420 at focal point 410 . [0067] The result is that the overall focal length of the device itself is kept quite short as mentioned above. Also important is the fact that the system operates in a near Littrow configuration. Additionally, the image space chief rays for the various input wavelengths are parallel, a characteristic commonly referred to as telecentricity. The optical system formed by reflective elements 90 and 92 must be properly designed with respect to the spectrally dispersed beam diffracted by grating 300 to support the telecentricity condition. [0068] In a typical nontelecentric optical system, the image space chief rays for separate wavelength channels would not be parallel, greatly complicating coupling of these focused beams into individual fibers. For example a telecentric optical system allows the individual output fibers to be aligned in parallel in a v-groove assembly which captures all of the fibers in parallel tracks. In addition, parallel optical processing of the individual spectral channels by common optical processors typically requires the individual spectral channels to be optically parallel. [0069] Thus not only does the subject system separate the beams out spatially, it also produces parallel beams at the output to greatly simplify detection and processing. [0070] Since the system described above for the optical multiplexer/demultiplexer is near-Littrow, the spectral dispersion of incoming light is magnified, thereby to provide significant spatial separation on the focal plane for the various colors of light involved. Demultiplexer Configuration [0071] Referring again, to FIG. 4A , this shows a schematic diagram of the compact optical multiplexer/demultiplexer 80 in the x-y plane, i.e., the plane containing the optical axes of the various optical elements, in the region of the entrance aperture. The z, or vertical, axis is pointed up out of the plane of the figure. When operated as a demultiplexer, light enters the instrument at the entrance aperture 100 . The entrance aperture can be a physical stop or slit but, typically, the entrance aperture is simply the location in space from which the optical multiplexer/demultiplexer optics have been designed to accept light. Preferably, multispectral light 115 is injected at the entrance aperture 100 by a cleaved or lensed optical fiber 110 , wherein the core 112 of the fiber represents an unresolved, or point, source to the opticalmultiplexer/demultiplexer optics. Typically, the fiber core is between 5 and 20 microns in diameter. In a typical optical communications application, the wavelength spectrum of the input, multispectral light 115 spans one or more of the so called C or L bands (typically 1525-1565 nm and 1570-1610 nm respectively). [0072] FIG. 5 shows two alternative means for injecting light 115 into optical multiplexer/demultiplexer 80 . One alternative means uses an extra focusing lens 111 to form the point source in the entrance aperture 100 ; while the second alternative uses a simple back-illuminated pinhole 114 . In yet another alternative the entrance aperture is generally slit shaped, with the narrow dimension of the slit being comparable to the pinhole or fiber core 112 . The long dimension of the slit is oriented parallel to the z-axis of the device illustrated in FIG. 4A . [0073] As is well known, light emerging from the core of a cleaved optical fiber is generally radiated into a large angled cone. Capturing all the light in such a cone is typically difficult to accomplish. Thus, as shown in inset FIG. 48 , an interface optic 120 is preferably included in close proximity to input fiber 110 as a means to increase the optical efficiency of the instrument. In one embodiment, interface optic 120 is a positive power, refractive lens. If the tip of the fiber is located within one focal distance of this lens, the light emerging from the exit face of the lens will be a less broad cone. The gap between fiber 110 and interface optic 120 may contain air or epoxy. For the preferred implementation of optical multiplexer/demultiplexer 80 , the source fiber radiates light 115 into a cone of numerical aperture (NA) of approximately 0.01 at the 1/e2 intensity and exits interface optic 120 with an NA of approximately 0.022. It will be appreciated that the details of the optical design of this interface optic depend heavily on the choice of input fiber, desired instrument performance and size, and so forth; and that many specific designs for this optic are possible without deviating from the intent of this invention. [0074] Returning again to FIG. 4A , the light exiting interface optic 120 expands in a narrow cone 118 as it propagates toward reflector 90 that serves as primary optic 800 . Primary optic 800 is a positive power reflective optic. Preferably, for ease of manufacture, the concave, focusing surface of primary optic 800 is substantially a portion of a sphere. Alternatively the focusing surface of primary optic 800 can be a portion of an asphere, as is understood in the field of optical design. The cone of light is directed such that it bypasses a secondary optic 850 and impinges on a small portion 200 of primary optic 800 . Portion 200 functions as the collimator for the optical multiplexer/demultiplexer. In the preferred configuration shown in FIG. 4A collimator portion 200 is located at one edge of primary optic 800 . [0075] Note, the distance between the plane input aperture 100 and primary optic 800 , as measured along the optic's optical as is substantially the effective focal length of primary optic 800 . Light cone 118 is thus substantially collimated by primary optic 800 . Additionally, input aperture 100 is located substantially on the optical axis of prim optic 800 . However, in other configurations the entrance aperture 100 can be above or below the plane of FIG. 4A . Upon reflection from collimator portion 200 , the light propagates generally parallel to the optical axis of primary optic 800 , as collimated beam 130 , until it reaches the plane diffraction grating 300 . The grating is located by standard optical ray tracing methods to intercept collimated beam 130 . This position will vary relative to primary optic 800 as a function of the selected location for input aperture 100 . [0076] Grating 300 is selected from industry standard designs and can be directly ruled, replicated in epoxy, or made holographically. Preferably, grating 300 is designed to operate in the wavelength band of interest in the so-called Littrow configuration. [0077] The salient characteristic of a Littrow grating, as shown in FIG. 4A , is that the first useful diffracted order propagates generally back toward the direction from which the input beam comes. A preferred form of grating 300 is the echelle grating, in which a coarse-pitched grating is used at a high grating order to achieve large angular dispersion. The demultiplexed outputs for all wavelengths of interest are preferably diffracted from the grating 300 in the same grating diffraction order, with the diffraction grating grooves blazed to maximize diffracted throughput into the utilized diffraction order. An alternative embodiment utilizes high-order echelle gratings with each of a number of discrete demultiplexed wavelengths diffracted into a different diffraction order, all having maximum grating efficiency for a single grating blaze angle. [0078] Grating 300 diffracts beam 130 generally in the backwards direction, with each of the different wavelengths in beam 130 each being diffracted at its specific angle according to the well-known grating equation. The central wavelength in beam 130 , when diffracted, becomes collimated return beam 140 . In the preferred embodiment, grating 300 is designed according to well-understood principles to operate in a near-Littrow configuration such that collimated return beam 140 propagates back to primary optic 800 at an angle α relative to beam 130 . In the preferred embodiment, angle α is less than 10 degrees and typically equal to 4 degrees. As is shown in FIG. 4A , angle α is designed to return beam 140 to primary optic 800 closer to the optical axis than beam 130 . That is, beam 140 is coming from larger field angle than beam 130 , relative to primary optic 800 . [0079] Beam 140 impinges on primary optic 800 in region 310 , slightly displaced from region 200 . Note, regions 200 and 310 are depicted as non-overlapping for clarity, but may overlap by approximately 50%. [0080] After reflecting from region 310 on primary optic 800 , the diffracted light is converted from collimated beam 140 to converging beam 150 . Left undisturbed, beam 150 would come to a focus in essentially the same plane as input aperture 100 , but displaced downward in FIG. 4A by the effect of angle α. It will be understood by one skilled in the art that beam 150 , while referred to in the singular when it represents the beam formed by a single wavelength from the original spectrum of the input light, the single wavelength to be substantially at the center of the operating wavelength band of optical multiplexer/demultiplexer 80 , is actually is meant to indicate the continuum of beams propagating in the optical multiplexer/demultiplexer, each wavelength in the source having been uniquely directed by the dispersive nature of grating 300 . Each additional wavelength in the source has its own converging cone leaving region 310 , with each cone coming to focus in a common output plane 420 , thereby forming a dispersed spectrum in that plane. [0081] In optical multiplexer/demultiplexer 80 , the one or more beams 150 do not propagate directly to focus. Instead, they are reflected from secondary optic 850 and again by primary optic 800 . The converging beams impinge on secondary optic 850 in a small region near its edge, indicated by region 320 , and then impinge on primary optic 800 in region 330 . Together the three regions 310 , 320 , and 330 form a long focal length telephoto imaging system that focuses the collimated beam(s) from the grating into a continuous intensity distribution 410 at output plane 420 . This represents the spectral content of input light 115 . Thus, the invention has demultiplexed a multiple wavelength input beam. In the preferred implementation, the imaging system has an effective focal length of 180 mm and forms an f/23 cone at the distribution 410 . [0082] When the optical multiplexer/demultiplexer is used as a demultiplexer, the imaging system formed by primary optic 800 and secondary optic 850 forms a magnified image 410 of the spectrum on the sensitive surface of a detector 400 , which has been located in the output plane 420 . The detector is preferably selected to respond to the wavelength band of interest. Typically, detector 400 is an array detector composed of multiple independently readable detector elements, although film and spectroscopic plates may also be used. Preferably, the magnification of the imaging system is designed such that the element-to-element spacing in the preferred detector produces the desired spectral sampling. A refractive field lens may be added in proximity to the detector plane to flatten the image field and, if desired, to adjust the telecentricity of the spectrograph. [0083] In an alternative configuration, a relay magnification optical system can be located after image 410 to adjust the size of image 410 to match the desired spectral sampling with the element-to-element spacing in the preferred detector. The use of such an image magnification-matching relay is well known in the art. [0084] Returning to FIG. 4A , the preferred optical design for the telephoto imaging system comprising regions 310 , 320 , and 330 has a back focal length (essentially the distance at which the spectrum 410 is formed) of 17 mm. Since the back focal length is shorter than the effective focal length (180 mm), the imaging system is a telephoto design, providing high magnification in a compact package. [0085] Functionally, the collimator and imaging system optics for this demultiplexer are formed from three independent elements corresponding to regions 200 / 310 , 320 , and 330 . These three elements, each of which is an eccentric pupil subaperture of a larger parent optical element, must be mounted and aligned relative to each other to form the collimator and imaging systems described above. Preferably, the collimator and imaging system are assembled from the two full-width elements themselves, i.e. primary optic 800 and secondary optic 850 . Each of these patent optics is a section of a centered spherical mirror with a diameter determined by the off-axis locations of regions 200 and 320 (for optic 800 and 850 respectively). The manner in which these elements are sectioned are described below. Since these two optical elements are centered, they can be easily mounted and aligned using simple techniques that are well-known in the industry and will be described below as well. [0086] The optical design parameters for the preferred embodiment of the multiplexer/demultiplexer have been determined using commercial optical design software. Table I is the optical design diagram showing the preferred embodiment with the corresponding optical design listing (“the lens prescriptions”). It will be noted by those of skill in the optical design art that the entire system comprises two powered elements, these being reflective spherical optical elements. [0000] TABLE I Lens Prescription for 1547 nm Wavelength, NA 0.02 input RDY THI OBJ: INFINITY 3.457700 STO: INFINITY 0.000000  2: INFINITY 0.000000  3: INFINITY 118.654508  XDE: 0.000000 YDE: −69.149831  ZDE: 0.000000 REV ADE: 11.514052  BDE: 0.000000 CDE: 0.000000  4: −439.64270   −123.285456   REFL SLB: “M1”  5: −251.80151   123.285456  REFL SLB: “M2” XDE: 0.000000 YDE: 7.425031 ZDE: 0.000000 DAR ADE: −4.676107  BDE: 0.000000 CDE: 0.000000  6: −439.64270   0.000000 REFL SLB: “M3”  7: INFINITY 0.000000 XDE: 0.000000 YDE: −36.860825  ZDE: 0.000000 REV ADE: 4.012577 BDE: 0.000000 CDE: 0.000000  8: INFINITY −169.251359   XDE: 0.000000 YDE: 36.770465  ZDE: 0.000000 REV ADE: −4.012577  BDE: 0.000000 CDE: 0.000000  9: INFINITY 166.672006  REFL SLB: “GRT” GRT: GRO: −22.000000  GRS: 0.018986 GRX: 0.000000 GRY: 1.000000 GRZ: 0.000000 XDE: 0.000000 YDE: 48.643024  ZDE: 0.000000 DAR ADE: 63.577583  BDE: 0.000000 CDE: 0.000000 10: −439.64270   −217.650880   REFL SLB: “COL” IMG: INFINITY 0.000000 XDE: 0.000000 YDE: 13.729200  ZDE: −0.000000 DAR ADE: 11.828300  BDE: 0.000000 CDE: 0.000000 [0087] As mentioned above and referring now to FIG. 6 , it is a feature of the subject invention that the optics involved provide a telescope having telecentricity. As can be seen, spherical reflector 90 collimates light from a point source onto grating 300 which diffracts the multispectral light as illustrated at 802 back towards spherical reflector 90 . From there a portion of spherical reflector 90 focuses the incident light onto a reflective element 320 which in turn continues the focusing action and realms the light to another portion of spherical reflector 90 , with each of the different colored beams spatially separated. [0088] These spatially separated beams on spherical reflector 90 are again focused to output plane 420 such that individual beams of light 808 of different colors impinge On Output plane 420 from the same direction. The arrival of these differently colored beams of light in parallel permit detection by detectors 400 or coupling of the light into respective optical fibers positioned at plane 420 such that the centerlines of these fibers are also parallel one to the other and can therefore line up with the corresponding beams. This alignment is made simple due to the parallelism of beams 808 which can be matched to the parallelism of the optical fibers. This permits the use of the v-channel positioning block of FIG. 13 . [0089] Referring to FIG. 7 , in certain circumstances a higher performance system may be desired. In such circumstance the design performance limitations of a two element pure spherical system may be improved by removing one or both of those constraints (viz., two element constraint and spherical only constraint). FIG. 7 is the optical design diagram for an embodiment freed from those constraints in which the individual optical surfaces may be a mixture of spherical, conic, or aspheric surfaces, here respectively a parabolic section 810 , an aspheric section 812 , an aspheric surface 814 for element 850 , and an aspheric section 816 . What is shown here is a segmented mirror configuration for primary optic 800 . [0090] As shown in FIG. 8 , all components of optical multiplexer/demultiplexer 80 are assembled as a compact package, mounted on a unitary base structure 1000 for stability. Each component is preferably mounted using pre-determined reference points, typically miniature dowel pins. Analyses have shown that system performance will not be degraded when said alignment reference points are positioned to within 0.001-0.002 inches, a tolerance well within standard practice in optical assembly technology. Preferably the structure is athermalized. For example, base structure 1000 is preferably manufactured from Zerodur®, a well known substrate material, although fused silica and ULE® glass are acceptable alternatives. Additionally, kinematic or quasi-kinematic mounting configurations are preferred. [0091] Referring to FIG. 9 , a perspective view of the instrument shows that primary optic 800 and secondary optic 850 preferably implemented as rectangular sections 801 cut from parent optical elements 802 and 804 . The thickness, T, of the elements is equal to the clear aperture required for beam 118 when it reaches primary optic 800 plus additional margin for manufacturing, alignment and mounting considerations, as is typically done in optics manufacture. Alternative manufacturing approaches, such as optical replication, injection molding, or diamond turning are anticipated by the inventors. Spectral Manipulator Configuration [0092] Another application for the invention is to permit individual and unique manipulation, or filtering, of the various spectral components that make up the light emitted from the source. For example, one might warn to equalize the optical energy across the visible spectrum in the light emitted by a blackbody source of known emission temperature. A second preferred configuration of the invention is used for this application. For filtering, the optical multiplexer/demultiplexer is used in a double pass mode. That is, the light is injected into the optical multiplexer/demultiplexer in the input plane, is dispersed passing through the instrument, and is formed into a continuous spectrally dispersed display in output plane 420 as before. However, detector 400 is replaced by other elements that firstly manipulate each component of the spectrum individually and secondly return the light into the optical multiplexer/demultiplexer instrument for a second pass. During this reverse, second pass, the previously spectrally dispersed light is recombined by the aforementioned grating element into a single beam and is refocused into an output point by the optical multiplexer/demultiplexer optics. [0093] The modifications to the invention to accommodate this double pass operation are described with reference to FIGS. 10 and 11 . [0094] In an optical multiplexer/demultiplexer configuration, it is desirable to use a single optical multiplexer/demultiplexer 80 to spatially demultiplex the spectral components or channels of an input signal for some form of optical processing, and to subsequently multiplex the processed light signals back into a single output beam. [0095] FIG. 11 presents a geometry for the demultiplexed region after the optics in which multiple sequential Spectral Manipulating Elements (SMEs) can be inserted and the light retroreflected appropriately such that the optical multiplexer/demultiplexer 80 will properly multiplex the signals. The retroreflection path illustrated in FIG. 11 , when combined with the optical multiplexer/demultiplexer 80 illustrated in FIG. 4A , directs the multiplexed processed output out of the multiplexer/demultiplexer. [0096] As shown in FIG. 10 , the optical multiplexer/demultiplexer 80 of FIG. 4A may be modified to direct the output beam through an exit aperture 105 and output fiber 110 a spatially separated from the entrance aperture 100 . FIG. 10 is a view of optical multiplexer/demultiplexer 80 in the plane of cut A-A in FIG. 4A in the region of the entrance and exit aperture. In this second preferred configuration, entrance aperture 100 is offset out of the plane of 106 FIG. 4A below plane 106 . That is, the aperture is displaced in the z-axis direction below plane 106 . Exit aperture 105 exists above plane 106 to capture the processed beam. Note, the entrance aperture is shown offset in the negative z-direction below the plane of FIG. 4A ) although a positive offset is equally preferred. The offset entrance aperture 100 is matched symmetrically by an exit aperture 105 positioned above plane 106 , in the z-direction. Multispectral light is introduced into optical multiplexer/demultiplexer 80 as in the prior configuration, shown in FIG. 4A , as expanding cone 118 . The propagation of this light through the instrument proceeds as in the prior configuration and exits optical multiplexer/demultiplexer 80 as beam 118 a. [0097] FIG. 11 shows the additional elements in the region near output plane 420 required to implement the processing of the dispersed beams from the optical multiplexer/demultiplexer and to allow the spatially separated input and output apertures of FIG. 10 . Detector 400 of FIG. 4A is replaced by the combination of one or more spectral manipulation elements (SME) 430 , 432 , and two broad band reflective surfaces 440 , 442 . Preferably, surfaces 440 , 442 are high reflection optical coatings deposited on optical substrates viz., front surface mirrors) as is well known in the art, where said coatings have been optimized for reflecting the operational wavelength band of the invention. [0098] As will be appreciated, FIG. 11 is a view of optical multiplexer/demultiplexer 80 in the region of cut B-B in FIG. 4A . Reflective surfaces 440 and 442 are positioned such that the normals to their respective surfaces are each in the plane formed by the central ray of beam 150 and the z-axis. Additionally, the reflective surfaces 440 , 442 are held at a right angle to each other. As is well known in the field of optics, surfaces held in this orientation retroreflect light beams in the plane in which the mirrors are folded. For beams propagating with a component out of aforementioned plane, the in-plane component is retroreflected and the out-of-plane component will be reflected as if the mirror pair were a single mirror (Lea, the angle of reflection equals the angle of incidence). [0099] As shown, first reflective surface 440 is located in front of image plane 420 by displacement distance, D, 153 and oriented at substantially 45 degrees to the direction of propagation of beam 150 , with its reflective side facing beam 150 . First reflective surface 440 is generally located such that the central ray of beam 150 intercepts surface 440 substantially at its center. Second reflective surface 442 is located at substantially 90 degrees to first surface 440 and also facing the beam 150 and located such that the central ray of beam 150 intercepts its surface substantially at its center. Displacement distance D is substantially equal to one-half the distance between surface 440 and surface 442 , as measured along the central ray of beam 150 . In this configuration, output plane 420 a , the plane containing the optical axes of the optical components, is substantially parallel to beam 150 and located midway between surfaces 440 and 442 . [0100] Preferably, light converging toward output plane 420 first passes through SME 430 , whose function will be described below. Note that beam 150 is traveling above (z-positive) the plane 420 a containing the optical axes of the optical components. The beam is above the axis near output plane 420 because input aperture 100 is located below said plane, as was described above. Similarly, beams 150 would be below this plane had the input aperture been place above the plane. [0101] Beam 150 impinges on surface 440 and is reflected downwards (e.g., generally along a direction parallel to the z-axis) toward surface 442 . Output plane 420 a is formed mid-way between surfaces 440 and 442 , in accordance with the said selection of displacement distance 153 . The forward pass of this double pass configuration is complete when beam 150 reaches its focused condition in output plane 420 a , wherein a continuous spectral distribution is formed. [0102] As the light passes through focus in output plane 420 a it re-expands in defocusing beams 150 a as it begins its second pass through the optical multiplexer/demultiplexer 80 . The spectral distribution in output plane 420 a now serves as the source for the optical multiplexer/demultiplexer. Emerging from output plane 420 a (i.e. plane 106 of FIG. 10 ) beams 150 a impinge on reflective surface 442 and are reflected into a plane substantially parallel to, but displaced in the negative z-direction from the plane containing beam(s) 150 , with the said displacement being substantially equal to the aforementioned positive displacement of beams 150 . The redirected beams are pointed generally back to primary optic 800 and appear to be emerging from a spectral distribution in output plane 420 c . The beams diverging from output plane 420 c toward primary optic 800 preferably pass first through SME 432 , whose function will be described below. [0103] Beams 150 a propagate generally back to primary optic 800 until they reach region 330 . From region 330 backwards-propagating beams 150 a generally retrace the paths taken by forward-propagating beams 150 . Beams 150 a are generally slightly displaced from their corresponding beams in beams 150 , the displacement being in accordance with well understood optical ray tracing analyses and having no significance to the effect of the various optics in optical multiplexer/demultiplexer 80 . [0104] When beams 150 a reach region 310 they become substantially collimated beams 140 a . Beams 140 a are in direct correspondence with forward propagating beams 140 . Beams 140 a impinge on grating 300 at angles of incidence corresponding to their wavelengths and thus, are rediffracted by grating 300 into a common propagating direction where they are collectively considered a single beam, beam 130 a . Beam 130 a propagates to region 200 of primary optic 800 where it is focused toward exit aperture 105 as beam 118 a . At the exit aperture, the focused beam 118 a is typically coupled into an optical fiber and out of the optical multiplexer/demultiplexer 80 . [0105] The function of the double pass configuration just discussed is to provide a physical space in which one or more spectral manipulation devices can operate on the various spectral components in the original optical signal independently. That is, if the optical signal traveling in the input optical fiber is composed of light at two distinct wavelengths, say 1540 TIM and 1550 nm, it is the purpose of this invention to allow one optical adjustment to be applied to the 1540 nm light and a separate and independent adjustment to be applied to the 1550 nm light. For example, it may be desirable to attenuate the 1550 nm light by 10% without affecting the 1540 nm light in order to equalize the optical power in the two wavelengths. [0106] In FIG. 11 , the preferred configuration, in which two SMEs are installed, is illustrated. Alternatively, a single SME could be used alone, positioned in the location of either SMF 430 or 432 or in the output plane 420 located between the reflective elements 440 , 442 . A further alternative configuration would permit three SME's to be used, with one SME in plane 420 and one each corresponding to SMF 430 and 432 . [0107] Preferably, the SME's are located close to output plane 420 , said plane being the location at which the various spectral components are most distinct. However, exact positioning in this plane is not required since the spectral manipulation performed by the SME's are always of finite spectral resolution themselves and, typically, are slowly varying with wavelength. The manipulation performed by a SME 430 may be continuous with spatial position (said spatial position corresponding to different wavelengths) or spatially discrete. A physically large example of the former is a variable neutral density filter, such as Newport Research model 50G02AV.2 while an example of the latter could be a Dichroic Filter Array as produced by Ocean Optics Inc. of Dunedin, Fla. using technology under license of U.S. Pat. No. 5,711,889, Methodology to make optical filter arrays. Any of a large variety of SMEs may be used in the invention, and different numbers and types of SMEs may be mixed and matched in the invention while remaining within the intent of invention, which is to make a physically accessible region available in which individualized manipulation of the spectral components is possible. Multiplexer Configuration [0108] Referring to FIG. 12 , the multiplexer configuration is shown, here a third configuration for optical multiplexer/demultiplexer 80 is to reverse the functions of the input and output planes to create a means of multiplexing several individual light sources into a single, combined beam. The optical system for the multiplexer configuration, shown in FIG. 12 , except for the elements in the input and output planes, is unchanged from the demultiplexer configuration shown in FIG. 4A . Former output plane 420 is, in this configuration, the location for one or more light sources, typically narrowband fiber lasers 510 , held in a fiber positioning block 500 . Bach laser 510 is tuned to a unique wavelength within the dispersive range of grating 300 . The source may alternatively be a semiconductor laser array with individual laser facets tuned to the appropriate laser wavelength. Former input plane 100 , typically, is just a reference location through with the multiplexed beam will pass at focus. [0109] For one preferred embodiment, grating 300 is operates at the 22 nd order in a near-Littrow configuration and, with the 2 mirror optical design, the angular dispersion of the grating is converted into a physical dispersion of 100 GHz/millimeter at output plane 420 . Output plane 420 is approximately 50 millimeters wide, so the multiplexing range of this embodiment is approximately 5000 GHz. [0110] In a multiplexer, it is desirable to precisely overlap each of the input beams to obtain high output beam quality. To achieve said precision overlap, each input source is positioned precisely in former output plane 420 . In a preferred embodiment as shown in FIG. 13 , each source is an optical fiber 510 mounted in a v-channel 520 in positioning block 500 , with the location of the v-channel for each fiber having been calculated specifically for the wavelength to which the source is tuned and the specific grating 300 and optical elements in the system. [0111] Each fiber in positioning block 500 emits a cone of light 150 . It will be understood that only one cone is illustrated for clarity but in operation there will be multiple, nearly parallel cones of light being emitted simultaneously. As illustrated in FIG. 12 , the light in cone 150 propagates “backwards” through the optical multiplexer/demultiplexer, reflecting sequentially from region 330 , region 320 , region 310 , grating 300 , and region 200 before coming to focus in plane 100 . At former input aperture 100 all of the cones of light that are emitted from block 500 are substantially overlapped to form a single output beam. An alternative embodiment takes advantage of the fact that the input laser beams are overlapped and coboresighted into a high quality collimated beam after diffracting from grating 300 . This beam may be used as the free-space collimated output of the multiplexer if the grating 300 is oriented at an appropriate angle α such that the output beam clears optical element 800 . [0112] A preferred form of grating 300 is the echelle grating, in which a coarse-pitched grating is used at a high grating order to achieve large angular dispersion. The multiplexed outputs for all, wavelengths of interest are preferably diffracted by the grating 300 into the same grating diffraction order, with the diffraction grating grooves blazed to maximize diffracted throughput into the utilized diffraction order. An alternative embodiment utilizes high-order echelle gratings with each of a number of discrete multiplexed wavelengths diffracted into a different diffraction order, all having maximum grating efficiency for a single grating blaze angle. Accordingly, in this alternative embodiment, all multiplexed wavelengths emerge into a common angular direction; each wavelength being diffracted at or near the peak efficiency of the blaze function for that discrete wavelength and diffracted order. The peak of the blaze function repeats with diffracted order and in this embodiment, each wavelength uses a different diffracted order. So, wavelength separations can be chosen such as to align with the peak diffraction efficiency of subsequent diffracted orders. For example, an echelle grating can be created such that the order separation corresponds to approximately 100 GHz in frequency or 0.8 nm in wavelength in the 1.5 micrometer wavelength region. Such a grating would provide peak diffraction efficiency at each discrete wavelength in the diffraction order in which it is used, sending all wavelengths into a common output angular direction. Another embodiment of grating 300 would be a multilayer dielectric interference grating, allowing high power laser output. [0113] While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications or additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.

An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

BACKGROUND OF THE INVENTION The present invention relates to a headlight in particular for providing a high beam and a low beam in a vehicle, which has a reflector, a light source, and an adjusting device for adjusting the light source relative to the reflector between a position for the low beam and a position for the high beam. Such a headlight is disclosed for example in the German patent document DE 44 35 507 A1. In this reference the light source is movable in direction of the optical axis of the reflector and also vertically to the optical axis of the reflector. For performing the movement oriented vertically to the optical axis, the light source is turnable about an axis arranged perpendicular to the optical axis of the headlight. An electric motor is connected with the light source at a distance from the axis and turns the light source about the axis. For converting the rotary movement of the electric motor into the turning movement of the light source, it is proposed in this reference to use a thread, a transmission, a coulisse guide or a cam disk, etc. With the corresponding control of the electric motor the light source is moved to the position for the low beam or to the position for the high beam. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a headlight for the low beam and the high beam in a vehicle, which has a simple construction and provides a high operational safety. In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a headlight in which the adjusting device is provided with holding means which produces a holding force for fixing the light source in one of the two positions. The light source is not held by the adjusting device in both positions for the low beam and the high beam as in the prior art, but instead the holding device is provided for fixing at least one of the two positions. Thereby, it is possible, without high structural expenses to increase the operational safety of the total headlight. It is especially advantageous when the light source in the position for the high beam is fixed by the holding device. If there are some interferences in the position for the high beam and the like, then it is possible independently from the adjusting device to move back the light source from the position for the high beam to the position for the low beam. This is achieved in that the holding force is no longer produced by the holding device and thereby the light source is automatically moved from the position for the high beam to the position for the low beam. In particular, it is possible in the event of failure of the adjusting device, to move the light source back to the position for the low beam. In accordance with a further advantageous embodiment of the present invention, the holding device is formed as a coil or the like. Thereby the desired holding force can be produced electromagnetically by corresponding electrical control of the coil. With the corresponding arrangement of the coil, the holding force can act directly on the light source or on the metallic support of the light source. In an advantageous embodiment of the invention, a force which counteracts the holding force of the holding device is provided for acting on the light source. This counteracting force acts so that the light source, for example in the event of interference, in each case can move back from the position for the high beam to the position for the low beam. In this headlight, the position for the low beam represents a basic position, to which the light source always returns in the event of a failure or a similar disturbances. In a further advantageous embodiment of the present invention, a spring or the like is used for producing the counteracting force. This provides for a special and simple construction for producing the force which counteracts the holding force of the holding device. In accordance with another advantageous feature of the present invention, the means are provided for displacing the light source to the position which is fixed by the holding device. With this means, the light source also is moved from the position for the low beam to the position for the high beam. In the position for the high beam, the light source is fixed by the holding device. By means of the spring, the light source is again moved back from the position for the high beam to the position for the low beam. In a further embodiment of the invention, a cam or the like which is driven by the electric motor is used for displacement of the light source. It forms an especially simple structural element for moving the light source in direction toward the position fixed by the holding device. When the light source reaches the position for the high beam, it is fixed there by the holding device. The cam can move it to an initial position, so that the light source is again freely movable, and when needed can be moved back by means of the spring to the position for the low beam. This process can be repeated anytime, and the whole process is controlled by controlling of the electric motor of the cam and the controlling of the holding device. In a further preferable embodiment of the invention, the holding device and the means for displacing the light source in direction to the position fixed by the holding device are controllable by the user-standard operation of the low beam and the high beam. In the initial position, the light source is located in the position for the low beam. If a user wants to switch to the high beam, the light source is moved by the cam in direction toward the holding device. There the light source is fixed by the holding device in the position for the high beam. This can be provided by a corresponding electrical control, for example the coil. The cam moves back as mentioned above, again to its initial position. If a user wants to switch to the low beam, the holding device is deactivated. As a result, the light source is moved by the spring to the position for the low beam. The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, 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 The single FIGURE of the drawings is a view schematically showing an example of a headlight in accordance with the present invention, and in particular its part which is associated with a displacement of a light source inside the headlight. DESCRIPTION OF PREFERRED EMBODIMENTS A headlight in accordance with the present invention has a part which is provided in a vehicle for producing a low beam and a high beam and is shown in the drawings. The headlight has a reflector and a light source. The light source is reciprocatingly movable between a position for the low beam and a position for the high beam. For this purpose, an adjusting device 1 is provided as shown in the drawing. The adjusting device has an electric motor 2 which is provided with a screw transmission 3 or the like. The screw transmission 3 is coupled with a turnable control element 4 so that a rotary movement of the screw transmission 3 is converted into a rotary movement of the control element 4 . The control element 4 has a projecting cam 5 . A switch 6 is associated with the control element 4 . The control element 4 with the cam 5 is formed so that it can act on a substantially L-shaped holding member 7 . For this purpose, one leg of the holding member 7 abuts against a periphery of the control element 4 and thereby against a periphery of the cam 5 . The holding member 7 is supported so that it is reciprocatable in a direction 8 . A stationary abutment 9 is associated with the holding member 7 . A spring 10 is arranged between the abutment 9 and the holding member 7 so as to press the holding member 7 in direction 8 toward the control element 4 . In particular, the leg of the holding member 7 which does not abut against the control element 4 supports the spring 10 so that the other leg, as mentioned above, always abuts in particular against the periphery of the cam 5 . A coil 11 is arranged at the side of the holding member 7 which faces away from the control element 4 . The coil 11 is dimensioned so that it can hold the holding member 7 against the force of the spring 10 . The electric motor 2 , the switch 6 and the coil 11 are connected with an electrical control device, in particular with a microprocessor. Several operating elements are connected with the control device, so that an operator with the use of the operating elements can switch the vehicle from the low beam to the high beam. The holding member 7 is coupled with the light source, so that a displacement of the holding member 7 in direction 8 results also in the displacement of the light source. In an initial condition, the control element 4 and the holding member 7 are located in a position shown in a broken line. This position corresponds to the position for the low beam. The light source is located also in the position for the low beam. If a user wants to switch the vehicle to the high beam, it sets the electric motor in operation by the control device. As a result, the control element 4 with the cam 5 is moved from the position shown in a broken line to the position shown in a solid line. During this rotary movement, the holding member 7 is simultaneously displaced by the cam 5 in the direction 8 . This means that the holding member is moved in direction toward the coil 11 . In the position shown in the drawings, the light source is coupled with the holding member 7 which is the position for the high beam. This position is recognized by the switch 6 . As a result, the control device controls the coil 11 so that the holding member 7 is held by the coil 11 in the position shown in the solid line. The holding member 7 and thereby the light source are held by the coil 11 in the position for the high beam. Simultaneously, the control device controls the electric motor 2 in dependence on the switch, 6 so that either the control element is turned with the cam 5 to the position shown in a broken line, or the control element 4 is turned further with a cam 5 to the position which is opposite to the position shown in the broken line. In the first case the electric motor 2 changes the polarity by the control device, while in the second case the electric motor 2 operates further without changes. In general, a condition is produced, in which the control element with the cam 5 is located either in the position shown in the broken line or in the opposite position. The electric motor 2 is turned off. The holding member 7 is located in the position shown in the solid line and held by the coil 11 in this position. For this purpose, the corresponding required current flows through the coil 11 . The described position corresponds, as mentioned above, to the position of the high beam of the headlight. If the user of the vehicle wants to switch from the high beam to the low beam, it is only necessary that the control device turns off the current through the coil 11 . Thereby the holding member 7 is no longer held by the coil 11 . The force produced by the spring 10 results in that the holding member 7 is moved back in direction to the control element 4 . The holding member 7 is therefore moved to the position shown in the broken line, which corresponds to the position for the low beam. Instead of the cam 5 , also a cam disk or a similar element can be utilized. It is also possible to form the holding member 7 symmetrically. Also, it is possible to arrange the control element 4 rotatably so that a polarity change of the electric motor 2 is not necessary. It is also possible to dispense with the switch 6 . In this case the required switching of the motor 2 can be performed in that the coil 11 is provided with a switch or a similar sensor. In some cases it is also possible to use the current through the coil 11 for the determination. Furthermore, it is possible to provide the coil 11 with means for a return coupling. The return coupling ensures that the holding member 7 and thereby the light source reaches the position for the high beam. While the invention has been illustrated and described as embodied in headlight for low beam and high beam of a vehicle, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

A headlight for a low beam and a high beam in a vehicle has a reflector, a light source, an adjusting device operative for displacing the light source relative to the reflector between a position for a low beam and a position for a high beam, the adjusting device including holding means which produce a holding force for fixing the light source in one of the two positions.

FIELD OF THE INVENTION The present invention relates to an apparatus and a method for measuring and analysing/detecting different types of rotor and stator faults in induction motors and asynchronous motors. BACKGROUND ART Electric motors have a wide field of application. In industrial production, for example, electric motors are used to drive pumps, conveyor belts, overhead cranes, fans, etc. An electric motor, adapted for use in a specific application, offers the user many advantages, mainly owing to its long life and limited need for maintenance. One basic requirement for a long electric motor life is that the rotor in the electric motor does not have any faults or defects. Common types of rotor faults are, for example, breaks or cracks/fractures in a rotor bar, excessively high resistance in welded or soldered joints in the rotor, excessively large air cavities (as a result of the casting of the rotor) and rotor offset in air gaps relatively to the stator. Common types of stator faults are, for example, insulation faults between the turns of a winding, insulation faults between windings in the same phase, insulation faults between windings in different phases, insulation faults between windings and earth/motor casing, contaminated windings (i.e. impurities such as moisture, dust, or insulation charred due to overheating), an open turn of a winding in a delta-connected motor as well as contact problems between the winding ends and external connections. When measuring electric three-phase motors, it is common to measure current fundamental components during operation and to compare measurement data from the three phases. Usually, special sensors are used in these measurements to obtain measurement data. Measuring methods carried out during operation are sensitive to disturbances in the power grid, i.e. fundamentals generated by other machines (for example switched power supply units, fluorescent tube fittings, etc.) that are connected to the same power grid. These disturbances cause erroneous measuring results and may even make measurements on the electric motor impossible. When measuring stators according to prior art, a powerful surge voltage with high energy content is supplied to the motor, following which the exponentially decaying response obtained is analysed to identify possible faults in the stator. This measuring method has many disadvantages: it is a destructive method that may initiate or accelerate/bring to completion incipient insulation failures; it requires time-consuming and complex calculations and interpretations/analyses; it causes problems of pulse propagation in the winding due to L and C effects; it requires bulky and heavy equipment associated with transport/installation problems; and it is an expensive method. SUMMARY OF THE INVENTION One object of the present invention is to provide a method for safe checking of electric motors. More specifically, a method when checking an electric motor, which comprises stator windings and a rotor arranged along a rotation axis, is provided, the method comprising measuring a physical quantity of the stator winding while the rotor is being rotated about the rotation axis, thereby obtaining periodic measuring data concerning the physical quantity. The method comprises collecting measuring data concerning at least two periods of the periodic measuring data, comparing the symmetry between at least the fundamentals of two or more half-cycles of the collected measuring data and generating a signal, which indicates the symmetrical relation between at least the fundamentals of two or more half-cycles of the collected measuring data. A measuring device according to the present invention measures the current (I), impedance (Z) or inductance (L) of a stator winding in real time while the position of the rotor relatively to the stator is being changed in fixed steps or by continuous rotation. In addition, the apparatus displays the resulting relationship/waveform on a graphic screen in real time. The relationship can be considered to be the measure of how the relative inductance between the rotor and stator varies. In the majority of all three-phase asynchronous motors, there is a sinusoidal relationship between the rotor position (X) and the value of I, Z or L on the stator (Y). This pattern includes a fundamental that is periodic/cyclic and symmetric about the x-axis in each phase. Certain harmonic components and/or disturbances may also be superposed on the periodic fundamental. Moreover, the number of cycles/periods per turn depends on the number of poles of the motor. Although the relationship is not always purely sinusoidal depending on, for example, stator windings having different structures and positions in relation to one another, it is always characterised in that it is cyclic and symmetric about the x-axis if the rotor is intact. Furthermore, the waveforms mentioned above are analysed with regard to symmetry/uniformity within one or more (and between two) periods/cycles, and to determine if any deviation is greater or smaller than predetermined criteria for rotor faults. All common types of rotor faults are reflected in some kind of effect on the symmetry/uniformity of the waveform that is normal for the motor type. Common types of rotor faults are, for example: a) breaks or cracks/fractures in a rotor bar, b) excessively high resistance in welded or soldered joints in the rotor, c) excessively large air cavities (following the casting of the rotor), d) rotor offset in air gaps relatively to the stator. Furthermore, a method when checking an electric motor, which comprises two or more stator windings, is provided, the method comprising measuring a physical quantity of the stator windings, thereby obtaining measuring data concerning the physical quantity. The method comprises comparing measuring data concerning the physical quantity, which measuring data have been measured for at least two stator windings, and generating a first signal, which indicates the relation between the measuring data measured for the at least two stator windings. Moreover, a representation of the generated first signal is displayed on a screen, the representation of the generated first signal being displayed in the form of three or more graphic figures disposed side by side. A difference between the measuring data obtained can be illustrated on the screen as a deviation of at least one of the graphic figures from an otherwise straight line comprising two or more graphic figures. According to the method, a user may select at least one graphic symbol, numeric measuring data for the at least one graphic symbol being shown on the screen. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described hereinafter with reference to the accompanying drawings, which show an embodiment of the invention as a non-limiting example. FIG. 1 is a block diagram of a preferred embodiment of a measuring device according to the present invention. FIG. 2 is a flow chart of a measuring method according to an embodiment of the present invention. FIG. 3 illustrates half cycles SY( 1 ) to SY( 4 ) used for determining the symmetry factors S 1 to S 3 . FIG. 4 is a schematic illustration of a pattern representing vertically arranged groups of quantities related to different phases. DETAILED DESCRIPTION Referring to the block diagram in FIG. 1 , a preferred embodiment of a measuring device 13 according to the present invention will be described. The measuring device 13 comprises a control unit 1 , which preferably comprise: a CPU 1 a , a program memory 1 b , a data memory 1 c , an A/D converter 1 d , a voltage reference 1 e , a first timer (A) 1 f , a second timer (B) 1 g and a hardware multiplier 1 h. The measuring device 13 comprises a screen 2 , which is connected to the control unit 1 . The measuring device 13 comprises a waveform generator 3 connected to the control unit, which preferably comprises: a D/A converter 3 a , a reconstruction filter 3 b and a power amplifier 3 c. The measuring device 13 comprises measuring amplifiers 4 in two channels, which preferably comprise: adjustable amplifiers 4 a , rectifiers 4 b , zero detectors 4 c and level shifters 4 d. The measuring device 13 comprises a switching unit 5 for providing inputs and outputs to a test object 10 . The switching unit, which is connected to an input of the measuring amplifier 4 , preferably comprises relays 5 a and analogue multiplexers 5 b. Furthermore, the measuring device 13 comprises a reference measuring resistor 6 , which is connected between the switching unit 5 and an input of the measuring amplifier 4 . A high-voltage generator 7 is connected between the test object 10 and the control unit 1 for testing the insulation resistance of the test object 10 . The high-voltage generator preferably produces a voltage on its output in the range of 500 V-1 kV. The measuring device 13 comprises a power supply device 8 , which preferably comprises one or more batteries 8 a , battery charging device 8 c , one or more voltage regulators 8 c and an LCD biasing generator. Moreover, the measuring device preferably comprises one or more analogue inputs 9 A and digital inputs 9 B. The control unit 1 monitors and controls the screen 2 , the waveform generator 3 , the measuring amplifiers 4 , the switching unit 5 , the reference measuring resistor 6 , the high-voltage generator 7 and the power supply device 8 , in accordance with program instructions stored in the memory 1 b , and records and calculates output data according to given program instructions, the result being illustrated on the screen 2 . More specifically, the control unit 1 controls the waveform generator 3 to generate a DC signal or a sinusoidal signal, whose frequency is preferably in the range of 25-800 Hz and whose voltage is preferably 1 V rms. The generated voltage is applied to the test object 10 via power amplifiers 3 c and the switching unit 5 . The current thus generated causes a voltage across the measuring resistor 6 , the measuring amplifier 4 being controlled to measure the voltage across the measuring resistor 6 and the test object, respectively. A first input of a first zero-crossing detector 4 c is connected to the output of the waveform generator 3 . The output represents the phase displacement of the voltage across the test object 10 . A second zero-crossing detector 4 c is connected to the output of the amplifier 4 a whish is adjustable to match the measuring resistor 6 , and its output signal represents the phase displacement of the current through the test object 10 . The above connection allows the current (I) trough the test object 10 to be calculated. It also allows the impedance (Z), inductance (L) and resistance (R) to be calculated. When measuring and calculating R in connection with an insulation test, the high-voltage generator 7 is used instead of the waveform generator 3 . The phase angle Fi is also measured. The program instructions required by the control unit 1 to carry out the above measurements/calculations are stored in the memory 1 b. A rotor test according to the present invention can be effected in two alternative ways. According to alternative 1 , a constant rotor speed is maintained to match the sweep time for viewing and calculation. According to alternative 2 , the shaft position is included in the measurement by means of an angle sensor 11 and a digital input 9 b , thereby connecting the measurement value with the rotor position. More specifically, in a rotor test according to alternative 1 the rotor position influences the measured value of the current (I), the impedance (Z), the inductance (L) and the phase angle (Fi) in the stator windings. The measured values vary between min/max, symmetrically in proportion to the position of the rotor relatively to the stator. By measuring I, Z, L and Fi in the stator winding during rotation and calculating this symmetry any rotor unbalance present will be detected. Provided that the collection of measuring data is linear over time and that the rotor is rotated at a constant speed adapted to the measuring data acquisition rate, the result is a graphic geometric representation for calculating and illustrating the measured values on the screen 2 . In a rotor test according to alternative 3 , in which an angle sensor 11 is connected to the shaft, the measured value is connected with the rotor position, the position thereby being the controlling factor in the horizontal direction. Referring to the flow chart in FIG. 2 (Sheets 1 and 2 ), a preferred measuring method according to the present invention will be described. In the first step 200 , the waveform generator 3 is started, thereby generating a measuring signal 25-800 Hz, 1 V rms, and connected via power amplifier 3 c and switching unit 5 to the test object 10 and the measuring resistor 6 optionally via connector terminals (indicated by X in FIG. 2 ). More specifically, the waveform generator 3 is started by starting the timer (B) 1 g and uploading a value corresponding to a sampling time t 1 . When the timer has counted down to zero, an interrupt is generated which causes the CPU 1 a to retrieve/look up the value of sample no. 1 in a table stored in the program memory 1 b , the value being supplied to the D/A-converter 3 a . At the same time, the timer (B) 1 g is restarted and reloaded with the value of t 1 . This process is repeated in connection with/after each interrupt of timer (B) 1 g by retrieving the next sample in the program memory 1 b and supplying it to the D/A-converter 3 a , thereby generating a series of discreet voltage levels representing the desired waveform plus the sampling frequency 1/t 1 . This signal is then sent to a low-pass/reconstruction filter 3 b , the function of which is to filter out the sampling frequency and any non-desirable frequency components, so that only the desired waveform remains. Before the waveform can be applied to the test object 10 impedance matching has to be effected. This takes place in the power amplifier 3 c from which the waveform is relayed to the test object 10 via relays in the switching unit 5 . In step 201 , the voltage across the test object 10 and the measuring resistor 6 , respectively, is registered in the measuring amplifier 4 (autorange). This is effected by the CPU 1 a setting the relays 5 a and multiplexors 5 b in the switching unit 5 so that the voltage across respectively the test object 10 and the measuring resistor 6 , which are connected in series, is switched to a respective adjustable amplifier 4 a , 4 b . The CPU sets the amplifiers 4 a , 4 b to the lowest amplifying level. The signals are then sent to rectifiers 4 c in which they are subjected to full-wave rectification, following which they are each supplied to a level shifter 4 e , which adapts the levels to the A/D converter 1 d . In this amplifying and switching state, the CPU 1 a starts the A/D converter 1 d , which together with the voltage reference 1 e via a software-based peak value detector type 1 , which will be described in more detail below, returns the peak voltage of both signals. Using these peak values, the CPU 1 a selects/calculates an optimal amplifying level for the adjustable amplifier of each channel and applies them. In these new amplifying states, the CPU 1 a again starts the A/D converter 1 d , which together with the voltage reference 1 e via a software-based peak value detector type 1 , returns the peak voltage of both signals. Using these peak values, the CPU 1 a verifies that the optimal amplifying state for the adjustable amplifier of each channel has been obtained. If this is not the case, i.e. if any one channel is overdriven the CPU 1 a may reduce the amplifying level by one step and apply the same. Alternatively, the signal across the measuring resistor can be so low that the CPU interprets this as if no test object were connected. Preferably, the maximum amplitude of the waveform generator 3 is also known. The input of the first zero-crossing detector is connected to the output of the waveform generator 3 . The output signal can be said to represent the phase displacement of the voltage across the test object 10 . The second zero-crossing detector is connected to the output of the adjustable amplifier adapted for the measuring resistor 6 and its output signal represents the phase displacement of the current through the test object 10 . Step 202 comprises measuring I, Z or L. The method of measurement used is method a or b, as described below, or a combination thereof. In measuring method a), a software-based peak value detector type 1 is used, i.e. the detector uses a back-up signal related to the zero crossings of the measuring signal to determine the peak value of the measuring signal. In measuring method b), a software-base peak value detector type 2 is used, which means measuring without a back-up signal. Both measurements are time-synchronised with the waveform, which thus forms the time base of the whole measuring sequence (1 measuring cycle=1 waveform period). Step 203 comprises initialising registration/memorizing of minimum and maximum values of I, Z and/or L. Step 204 comprises carrying out a software-based peak value detection type 3 without a back-up signal to detect a number of min/max cycles in the waveform resulting from the rotor signature envelope. A peak value detector type 3 is based on essentially the same software algorithm as a type 2 , but differs in terms of the indata and waveform processed. The indata for a peak value detector type 3 is the measurement result from one or more measuring cycle, i.e. output data from a peak value detector type 1 or type 2 (1 test cycle=1 waveform generator period; 1 measurement result=the result of one or more averaging test cycles). The waveform measured, on the basis of which the min/max values are obtained, is the rotor signature envelope, which is of sinusoidal or other shape, which appears from the envelope after a sufficiently large number of collected measurement results. Step 205 comprises updating the counter with regard to the number of min/max cycles. Step 206 comprises determining if the number of min/max cycles<16. If this is the case, the routine returns to step 202 . If not, the routine continues with step 207 . Step 207 comprises calculating the Y-mean based on the measured min/max values. This step also comprises initialising and/or setting to zero specific variables, for example dx=1, SY( 1 )=0, SY( 2 )=0, SY( 3 )=0 and SY( 4 )=0, the significations of which are shown in FIG. 3 . Step 208 comprises starting the main measurement loop of the rotor test, wherein I, Z and/or L is measured according to measuring method a) or b) or a combination thereof. The time between two x (the time when the test result from one or more test cycles is ready, each test cycle having been sampled and A/D converted) is a multiple of 1 test cycle (i.e. one waveform period). Step 209 comprises scaling I, Z and/or L to y(x). Step 210 comprises plotting y(x) on the display 2 to allow visual checking of waveforms. Step 211 comprises executing a software-based zero-crossing detection to obtain information regarding where the measuring data crosses the x axis. Step 212 comprises determining if zero_cross=1 or 2 according to the graph in FIG. 3 . If zero_cross=1 or 2, the routine proceeds with step 213 , if not the routine proceeds with step 214 . Step 213 comprises adding the current measurement value y(x) to the correct range of values and increasing dx, i.e.: dx++ if y(x)>y_mean SY( 3 )=SY( 3 )+y(x) if y(x)<y_mean SY( 4 )=SY( 4 )+y(x) Step 214 comprises checking if zero_cross=3. If this is the case, the routine proceeds with step 215 . If not, the routine proceeds with step 221 . Step 215 comprises determining the symmetry factors S 1 , S 2 , S 3 and increasing dx, i.e.: dx++ S ⁢ ⁢ 1 =   SY ⁡ ( 3 )  -  SY ⁡ ( 4 )   K ⁢ ⁢ 1 ⁢ ⁢ 100 ⁢ ⁢ K ⁢ ⁢ 2 dx S ⁢ ⁢ 2 =   SY ⁡ ( 3 )  -  SY ⁡ ( 1 )   K ⁢ ⁢ 1 ⁢ ⁢ 100 ⁢ ⁢ K ⁢ ⁢ 2 dx S ⁢ ⁢ 3 =   SY ⁡ ( 3 )  -  SY ⁡ ( 2 )   K ⁢ ⁢ 1 ⁢ ⁢ 100 ⁢ ⁢ K ⁢ ⁢ 2 dx S 1 is a measure/comparison of the symmetry between the half-cycles 3 and 4 in the current cycle. S 2 is a measure/comparison of the symmetry between the half-cycle 3 in the current cycle and the “negative” half-cycle 2 in the immediately preceding cycle stored. S 3 is a measure/comparison of the symmetry between the half-cycle 3 in the current cycle and the “negative” half-cycle 2 in the immediately preceding cycle stored. K 1 and K 2 are constant form factors and K 2 /dx is a compensating factor for different rotation speeds where dx=the number of x from zero crossing 1 to 3 . Step 216 comprises selecting the symmetry factor S 1 , S 2 or S 3 having the largest value, i.e.: if S 2 >S 1 S 1 =S 2 if S 3 >S 1 S 1 =S 3 Step 217 comprises displaying the result of the largest value S 1 on the screen 2 . Step 218 comprises determining if S 1 is larger or smaller than 5. It also comprises updating counters for rotor_ok and rotor_fault, i.e.: if S 1 >5 rotor_fault++ rotor_ok=0 if S 1 <5 rotor_ok++ Step 219 comprises saving the latest period as: SY( 1 )=SY( 3 ) SY( 2 )=SY( 4 ) Step 220 comprises initialising and/or setting to zero specific variables for a new period, for example: dx=1, SY( 3 )=0, SY( 4 )=0. Step 221 comprises increasing x. In this connection, xmax and rotor_fault and rotor_ok counters are checked, i.e.: x++ if x>xmax_display x=0 if rotor_ok >=8 print<5 beep if rotor_fault>=16 print>5 beep In step 222 , the routine returns to step 208 , and the main measurement loop restarts. In the following, an example of a stator measurement according to the present invention will be described. The measuring lines of the apparatus are connected to a delta or Y coupled motor with three phase connections, referred to below as A, B, C, and a connection to earth/motor casing (GND). Measurements of all quantities are effected between connections A-B, B-C and C-A, at all measuring frequencies f 1 , f 2 , f 3 . . . fn, except the insulation resistance which is measured between A-GND with a test voltage of 500 V or 1000 V. The main object of the tests/measurements is preferably not to study the absolute measurement values as such, but rather to study the resulting patterns and symmetry deviations caused by the different faults. In doubtful cases, the rotor should be rotated 90 degrees and the measurement carried out once more. The apparatus starts by an automatic change-over of measurement inputs for the purpose of measuring any interference voltage level (Uemi) possibly induced in the motor due to external interference fields, if any. If the level is too high, it is displayed on the screen of the apparatus, thereby allowing the user to take different measures in an attempt to reduce the interference level, for example grounding the test object to earth, etc. Thus, the ability of the apparatus to determine excessive interference voltage levels (Uemi) is a highly advantageous feature, since an excessive interference voltage level causes erroneous measurement results. If the interference level is sufficiently low, the apparatus proceeds, preferably automatically, by measuring and/or calculating the following quantities: Resistance (R), which is used to detect breakage in connectors or windings, loose connections, contact resistance and direct short circuits. Impedance (Z) and Inductance (L), which are used in combination to detect the presence of different impurities in the windings. These may be, for example, in the form of dust, moisture or charred insulation (due to overheating), which all cause small changes in the capacitance of the winding being measured. In most cases, the capacitance increases, which causes a reduction of the impedance Z. Moreover, the capacitive reactance will have a greater influence on the impedance (Ohm's law), since the test signal applied has low amplitude and the capacitance value therefore is even more dominant. In the case of insulation charred due to overheating, the capacitance may instead decrease, thereby causing the impedance to increase in one or more phases. Of all the measurement quantities, the inductance L is the one least likely to change due to a fault in the stator. Owing to this “inertia” the measurement results for L can be used as a form of reference or base line for comparison with changes in Z. However, depending on the motor type the values of L and Z will unfortunately vary to different degrees between the phases. The reason for this variation is that the effect of the rotor position on the relative inductance between the rotor and the stator may be different in each phase. One important feature in a motor without any other faults is that, despite these variations, the values and deviations of Z and L will still essentially follow one another in parallel in each phase. One important conclusion that can be drawn from the above reasoning is that the non-desirable effect of the rotor position on the phase balance in the values of Z and L is eliminated by studying the combined relationship. It follows from the above that if the pattern shows that Z and L are not parallel because of an increase or decrease in Z in one or more phases, this is an indication of a probable contamination in one or more stator windings. If, however, Z follows the other measurands but L deviates, this indicates some kind of rotor fault and the need for a special rotor test to be carried out for the purpose of a closer analysis. Phase angle (Fi) and IF or ZF, which are used in combination or separately to detect different insulation faults in stator windings. When a fault occurs in a winding, the effective capacitance in the complete circuit is changed. This capacitance change will directly affect the delay of the current relatively to the voltage, the common result being an increase of the capacitance and a decrease of Fi in the relevant phase. As the fault gets worse, it will start affecting adjacent phases. Usually, this occurs when the fault is located in one winding or between windings in the same phase. A very slight change in capacitance in the circuit can be detected and thus allows detection of faults in individual turns. A second method uses a relationship between two currents or impedances at two frequencies, fn and 2 fn=(frequency doubling). When the frequency is doubled small changes in capacitance between individual turns or between phases will be enhanced and cause a change of IF in at least one phase (see calculation of IF and ZF below). The combination of phase angle Fi and IF allows the detection of most types of faults. Normal values for IF should be in the range of −15% to −50%. Insulation resistance (INS), which is used to detect any insulation faults between windings and earth/motor casing. Below is an example of calculations of relative measurands according to the present invention. Noise voltage level (Uemi): The measurement result is presented as the absolute mean in mV or as the noise signal/useful signal ratio in dB.=20 log(Uemi/Usig). Resistance (R): R_A, R_BC and R_CA is presented as the absolute resistance in the range of 0.00 mΩ-999Ω or as R deviation between phases expressed in % and calculated according to the following: R_dev1=abs((R_AB−R_BC/R_AB)*100) R_dev2=abs((R_BC−R_CA/R_BC)*100) R_dev3=abs((R_CA−R_AB/R_CA)*100) Phase angle (Fi): is the phase shift between the current and the voltage in the range of 0-90.0 degrees. Fi difference between the phases expressed in degrees at measuring frequency=fn is calculated according to the following: Fi_diff1_fn=abs(Fi_AB_fn−Fi_BC_fn) Fi_diff2_fn=abs(Fi_BC_fn−Fi_CA_fn) Fi_diff3_fn=abs(Fi_CA_fn−Fi_AB_fn) Impedance (Z): Z deviation between phases expressed in % at measuring frequency=fn is calculated according to the following: Z_dev1_fn=abs((Z_AB_fn−Z_BC_fn/Z_AB_fn)*100) Z_dev2_fn=abs((Z_BC_fn−Z_CA_fn/Z_BC_fn)*100) Z_dev3_fn=abs((Z_CA_fn−Z_AB_fn/Z_CA_fn)*100) Inductance (L): L deviation between phases expressed in % at measuring frequency=fn is calculated according to the following: L_dev1_fn=abs((L_AB_fn−L_BC_fn/L_AB_fn)*100) L_dev2_fn=abs((L_BC_fn−L_CA_fn/L_BC_fn)*100) L_dev3_fn=abs((L_CA_fn−L_AB_fn/L_CA_fn)*100) IF and ZF: The results of IF and ZF are equivalent to one another but calculated slightly differently. To calculate IF or ZF, values of the current I or the impedance Z at two measuring frequencies, fn and 2fn, are used. The functions IF and ZF are expressed in %, from 0 to −50%, and calculated according to the following: IF_AB_fn=((I_AB — 2fn−I_AB_fn)/I_AB_fn)*100 IF_BC_fn=((I_BC — 2fn−I_BC_fn)/I_BC_fn)*100 IF_CA_fn=((I_CA — 2fn−I_CA_fn)/I_CA_fn)*100 ZF_AB_fn=((Z_AB_fn−Z_AB — 2fn)/Z_AB — 2fn)*100 ZF_BC_fn=((Z_BC_fn−Z_BC — 2fn)/Z_BC — 2fn)*100 ZF_CA_fn=((Z_CA_fn−Z_CA — 2fn)/Z_CA — 2fn)*100 IF and ZF differences between the phases at measuring frequency=fn are calculated according to the following: IF_diff1_fn=abs(IF_AB_fn−IF_BC_fn) IF_diff2_fn=abs(IF_BC_fn−IF_CA_fn) IF_diff3_fn=abs(IF_CA_fn−IF_AB_fn) ZF_diff1_fn=abs(ZF_AB_fn−ZF_BC_fn) ZF_diff2_fn=abs(ZF_BC_fn−ZF_CA_fn) ZF_diff3_fn=abs(ZF_CA_fn−ZF_AB_fn) Insulation resistance (INS): The measurement results are presented as the absolute insulation resistance in the range of 0.00 MΩ-500 MΩ. Following automatically effected measurements and calculations of measurands according to the above, the operator is presented with two options: The first is to manually study the values presented in graphic or numeric form. Graphic illustration of the calculated deviations and differences between the three phases is obtained by means of a specially designed system in which each deviation or difference is represented by a graphic symbol that changes both position and appearance depending on the extent of the deviations or differences, thus allowing the operator to instantly see the relationships between the phases and, at the same time, also read the rounded-off values in the same symbol position. Referring to FIG. 4 , each quantity is presented in vertically arranged groups of three, for example (R_dev1, R_dev2, R_dev3). To see the numeric values, the operator can press OK when the cursor is below the selected quantity group. In the left group in FIG. 4 , the differences between the phases for the selected one of the quantities outlined above is less than 1%, which means that the symbol on the screen are disposed along a vertical line. In the middle group, the value of the quantity deviates for the bottom phase 1-2%, which is illustrated as an offset of the symbol to the left or to the right depending on the sign of the deviation. In the right group, the value of the quantity deviates for the lowest phase 2-3%, which is illustrated by the symbol being located at the side of the vertical line. The value of the quantity measured for the top phase deviates more than 5%, which is illustrated by the symbol being drawn using thinner or broken lines. The percentages given above may, of course, vary depending on the kind of quantity to be measured and the intended test object. The second option is to have the apparatus interpret and analyse, in its software or hardware, the results according to a previously given set of rules and relationships according to the following: If Fi,IF,Z,L are OK and R_dev >3-5=>Check wiring technique, otherwise possible contact fault or open turn in delta-connected motor. If Fi_diff_fn >1 and IF_diff_fn >2=>Insulation fault between turns of the same winding. If Fi_diff_fn >1 and IF_diff_fn <2=>Insulation fault between windings in the same phase. If Fi_diff_fn <1 and IF_diff_fn >2=>Insulation faults between windings in different phases. If any IF_diff_fn >5=>Indicates serious short circuit. If INS<1.5-5 MΩ=>Insulation fault between windings and earth/motor casing. If Z and L are parallel=> Windings are not contaminated. If Z and L are not parallel=>Windings are contaminated. If Z follows R, Fi, and IF but L deviates>3=>Possible rotor fault, rotor test to be carried out.

An apparatus for testing an electric motor is described. The motor comprises stator windings and a rotor arranged along a rotation axis. The apparatus is adapted to measure a physical quantity of the stator winding while the rotor is being rotated about the rotation axis, whereby periodic measuring data concerning the physical quantity are obtained. The apparatus is adapted to collect measuring data concerning at least two periods of the periodic measuring data, to compare the symmetry between at least the fundamentals of two or more half-cycles of the collected data and to generate a signal that indicates the symmetrical relation between at least the fundamentals of two or more half-cycles of the collected measuring data.

CROSS REFERENCE TO PRIOR APPLICATIONS This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2013/070378, filed on Sep. 30, 2013 and which claims benefit to European Patent Application No. 12006822.6, filed on Oct. 1, 2012, and to European Patent Application No. 13003616.3, filed on Jul. 18, 2013. The International Application was published in English on Apr. 10, 2014 as WO 2014/053455 A1 under PCT Article 21(2). FIELD The present invention relates to a versatile, highly efficient process for the preparation of mono- and bisacylphosphanes, as well as for their corresponding oxides or sulfides. The present invention further relates to novel photoinitiators obtainable by said process. BACKGROUND Photoinitiators, in particular mono- and bisacylphosphane oxides, bearing further functionalized substituents, have attracted significant commercial attention since photoinitiators which are tunable with respect to the wavelength at which photoinduced cleavage occurs or which are linkable to other additives, such as sensitizers, stabilizers or surface active agents in order to avoid migration e.g., in food packaging, are highly desirable. Many approaches to achieve these goals have been published during the last decade. EP 1 135 399 A describes a process for the preparation of mono- and bisacylphosphanes and their respective oxides and sulfides the process comprising the steps of reacting substituted monohalophosphanes or dihalophosphanes with an alkali metal or a combination of magnesium and lithium, where appropriate in the presence of a catalyst, further reacting the resulting metallated phosphanes with carboxylic acid halides, and finally oxidizing the resulting mono- or bisacylphosphanes with sulfur or oxygen transferring oxidants. WO05/014605A describes the preparation of bisacylphosphanes via a process comprising the steps of first reacting monohalophosphanes or dihalophosphanes with an alkali metal in a solvent in the presence of a proton source, and then reacting the phosphanes obtained thereby with carboxylic acid halides. WO2006/056541A describes a process for the preparation of bisacylphosphanes, the process comprising the steps of reducing elemental phosphorous or phosphorous trihalides P(Hal) 3 with sodium to obtain sodium phosphide Na 3 P, then adding sterically bulky alcohols to obtain sodium phosphide NaPH 2 , reacting said sodium phosphide with two equivalents of an carboxylic acid halide to obtain sodium bisacylphosphides, and finally reacting said sodium bisacylphosphides with electrophilic agents to obtain bisacylphosphanes. WO2006/074983A describes a process for the preparation of bisacylphosphanes by first catalytically reducing monochloro- or dichlorophosphines with hydrogen at a temperature of from 20 to 200° C. under pressure in the presence of a tertiary aliphatic amine or an aromatic amine in an aprotic solvent to obtain the corresponding halogen-free phosphanes, and subsequently reacting said phosphanes with carboxylic acid halides to obtain mono- or bisacylphosphanes. However, for the variation of the non-acyl substituent(s) at the phosphorous atom the aforementioned processes either require the initial employment of an organic mono- or dihalophosphane already bearing such substituent(s) in a first reduction or metallation step, which significantly diminishes the variability of possible substitution patterns, or if e.g., sodium phosphides NaPH 2 are employed, the use of electrophilic compounds bearing a reactive halogen functionality at the substituent to be introduced, which renders such processes commercially less attractive. SUMMARY An aspect of the present invention is to provide an efficient and versatile process to prepare functionalized mono- or bisacylphosphanes an well as their respective oxides and sulfides. In an embodiment, the present invention provides a process for the preparation of compounds of formula (I): wherein, n is an integer, for example, an integer from 1 to 6, for example, 1, 2, 3 or 4, for example, 1 or 2, m is 1 or 2, R 1 , if n is 1 is a substituent of formula (IIa), —C (1) R 6 2 —C (2) H(Z)(R 7 )  (IIa) wherein, (1) and (2) indicate the numeration of the carbon atom, whereby C (1) is bound to the central phosphorous atom depicted in formula (I), and Z is a substituent selected from the group consisting of —CN, —NO 2 , —(CO)H, —(CO)R 8 , —(CO)OH, —(CO)OR 8 , —(CO)NH 2 , —(CO)NH(R 8 ), —(CO)N(R 8 ) 2 , —(SO 2 )R 8 , —(PO)(R 8 ) 2 , —(PO)(OR 8 ) 2 , —(PO)(OR 8 )(R 8 ) or heteroaryl R 6 and R 7 each substituent independently is hydrogen, Z or R 8 and R 8 independently of further substituents R 8 which may be present in the substituent of formula (IIa) is alkyl, alkenyl or aryl or two substituents R 8 irrespective of whether they are both part of a substituent Z or belong to different substituents selected from Z, R 6 and R 7 together are alkanediyl or alkenediyl or alternatively, where two substituents —(CO)R 8 are present within the substituent of formulae (IIa), are together —O— or —NR 4 —, whereby the alkyl, alkenyl, aryl, alkanediyl and alkenediyl substituents are either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —S—, —SO 2 —, —SO—, —SO 2 NR 4 —, NR 4 SO 2 —, —NR 4 —, —CO—, —O(CO)—, (CO)O—, —O(CO)O—, —NR 4 (CO)NR 4 —, NR 4 (CO)—, —(CO)NR 4 —, —NR 4 (CO)O—, —O(CO)NR 4 —, —Si(R 5 ) 2 —, —OSi(R 5 ) 2 —, —OSi(R 5 ) 2 O—, —Si(R 5 ) 2 O—, and either not, additionally or alternatively either once, twice or more than twice interrupted by bivalent residues selected from the group consisting of heterocyclo-diyl, and aryldiyl, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: oxo, hydroxy, halogen, cyano, azido, C 6 -C 14 -aryl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio, —SO 3 M, —COOM, PO 3 M 2 , —PO(N(R 5 ) 2 ) 2 , PO(OR 5 ) 2 , —SO 2 N(R 4 ) 2 , —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —COR 4 , —OCOR 4 , —NR 4 (CO)R 5 , —(CO)OR 4 , —NR 4 (CO)N(R 4 ) 2 , —Si(OR 5 ) y (R 5 ) 3-y , —OSi(OR 5 ) y (R 5 ) 3-y with y=1, 2 or 3, and, for example, also —N(R 4 ) 3 + An − , or or R 1 , if n is 1, is a substituent of formulae (IIb), (IIc) or (IId) —C (1) R 6 2 —N(R 8 ) 2   (IIb) —C (1) R 6 2 —NH(R 8 )  (IIc) —(C (1) ═O)—NHR 8   (IId) wherein, (1) indicates the carbon atom bound to the central phosphorous atom depicted in formula (I) and R 1 , if n is >1, in particular 2 to 6, for example, 2, 3 or 4 or, in another embodiment, 2, is a substituent of formula (IIe) or (IIf) R*[C (2) HR 9 —C (1) (R 9 ) 2 —] n   (IIe) R**[NH—(C (1) ═O)—] n   (IIf) whereby in formula (IIe), R* is either a divalent substituent selected from the group consisting of —CO— and —SO 2 — (for n=2), or a n-valent substituent selected from the group consisting of heteroaryl-n-yl and R 10 (-Het-(C═O)—) n , wherein Het independently is either O or NR 4 and R 10 is alkane-n-yl, alkene-n-yl, or aryl-n-yl, and wherein the carbonyl carbons are bound to the C (2) carbon atoms, whereby the aforementioned alkane-n-yl and alkene-n-yl substituents of R 10 are either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —CO—, —O(CO)—, —(CO)O—, NR 4 (CO)—, —(CO)NR 4 — and, either not, additionally or alternatively either once, twice or more than twice interrupted by aryldiyl, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: hydroxy, C 1 -C 8 -alkoxy, —COOM, —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —COR 4 , —OCOR 4 , —NR 4 (CO)R 5 , —(CO)OR 4 , (1) and (2) indicate the numeration of the carbon atom whereby each of the n C (1) carbon atoms is bonded to the central phosphorous atom depicted in formula (I) via the bond “—” shown on the right side of the bracket and R 9 independently of each other are hydrogen, alkyl, alkenyl or aryl or two substituents R 9 irrespective of whether they are both bound to C (2) or not are together alkanediyl or alkenediyl, whereby the aforementioned alkyl, alkenyl, alkane-n-yl and alkene-n-yl substituents of R 9 are either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —S—, —SO 2 —, —SO—, —SO 2 NR 4 —, NR 4 SO 2 —, —NR 4 —, —CO—, —O(CO)—, (CO)O—, —O(CO)O—, —NR 4 (CO)NR 4 —, NR 4 (CO)—, —(CO)NR 4 —, —NR 4 (CO)O—, —O(CO)NR 4 —, —Si(R 5 ) 2 —, —OSi(R 5 ) 2 —, —OSi(R 5 ) 2 O—, —Si(R 5 ) 2 O—, and, either not, additionally or alternatively either once, twice or more than twice interrupted by bivalent residues selected from the group consisting of heterocyclo-diyl, and aryldiyl, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: oxo, hydroxy, halogen, cyano, azido, C 6 -C 14 -aryl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio, —SO 3 M, —COOM, PO 3 M 2 , —PO(N(R 5 ) 2 ) 2 , PO(OR 5 ) 2 , —SO 2 N(R 4 ) 2 , —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —COR 4 , —OCOR 4 , —NR 4 (CO)R 5 , —(CO)OR 4 , —NR 4 (CO)N(R 4 ) 2 , —Si(OR 5 ) y (R 5 ) 3-y , —OSi(OR 5 ) y (R 5 ) 3-y with y=1, 2 or 3 and, for example, also —N(R 4 ) 3 + An − , and whereby in formula (IIf) R** is a n-valent substituent selected from the group consisting of alkane-n-yl, alkene-n-yl and aryl-n-yl wherby R** is bound to the nitrogen atoms, whereby the aforementioned alkane-n-yl and alkene-n-yl substituents are either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —CO—, —O(CO)—, —(CO)O—, —NR 4 (CO)—, —NR 4 (CO)O—, —NR 4 (CO) NR 4 —, —(CO)NR 4 — or isocyanurate, oxadiazintrione, uretdione, biuret or allophanate groups and, either not, additionally or alternatively either once, twice or more than twice interrupted by aryldiyl, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: hydroxy, —NCO, C 1 -C 8 -alkoxy, —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —COR 4 , —OCOR 4 , —NR 4 (CO)R 5 , —(CO)OR 4 , (1) indicates the numeration of the carbon atom whereby each of the n C (1) carbon atoms is bonded to the central phosphorous atom depicted in formula (I) via the bond “—” shown on the right side of the bracket, and R 2 and R 3 , are independently of each other aryl or heterocyclyl, alkyl or alkenyl whereby the aforementioned alkyl and alkenyl substituents of R 2 and R 3 are either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —CO—, —OCO—, —O(CO)O—, NR 4 (CO)—, —NR 4 (CO)O—, O(CO)NR 4 —, —NR 4 (CO)NR 4 —, and, either not, additionally or alternatively either once, twice or more than twice interrupted by bivalent residues selected from the group consisting of heterocyclo-diyl, and aryldiyl, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: oxo, hydroxyl, halogen, cyano, C 6 -C 14 -aryl; heterocyclyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio, —COOM, —SO 3 M, —PO 3 M 2 , —SO 2 N(R 4 ) 2 , —NR 4 SO 2 R 5 , —N(R 4 ) 2 —, —N + (R 4 ) 3 An − , —CO 2 N(R 4 ) 2 , —COR 4 —, —OCOR 5 , —O(CO)OR 5 , NR 4 (CO)R 4 , —NR 4 (CO)OR 4 , O(CO)N(R 4 ) 2 , —NR 4 (CO)N(R 4 ) 2 , whereby in all formulae where used, R 4 is independently selected from the group consisting of hydrogen, C 1 -C 8 -alkyl, C 6 -C 14 -aryl, and heterocyclyl or N(R 4 ) 2 as a whole is a N-containing heterocycle, R 5 is independently selected from the group consisting of C 1 -C 8 -alkyl, C 6 -C 14 -aryl, and heterocyclyl or N(R 5 ) 2 as a whole is a N-containing heterocycle, M is hydrogen, or 1/q equivalent of an q-valent metal ion or is an ammonium ion or a guanidinium ion or a primary, secondary, tertiary or quarternary organic ammonium ion, in particular those of formula [N(C 1 -C 18 -alkyl) s H t ] + , wherein s is 1, 2 or 3 and t is (4-s), and An − is 1/p equivalent of a p-valent anion, the process comprising at least the step of reacting compounds of formula (III) if n is 1 with compounds of formulae (IVa), (IVb), (IVc) or (IVd), R 6 2 C (1) ═C (2) (Z)(R 7 )  (IVa) R 6 2 C (1) ═N + (R 8 ) 2 An −   (IVb) R 6 2 C (1) ═NR 8   (IVc) R 8 —NCO  (IVd), if n is >1, with compounds of formulae (IVe) or (IVf), R*[R 9 C (2) ═C (1) (R 9 ) 2 ] n   (IVe) R**[NCO] n   (IVf), wherein in formulae (III) and (IVa) to (IVf), (1), (2), R 2 , R 3 , R 6 , R 7 , R 8 , R 9 , R*, R**, n, m, An − and Z have the same meaning as described for formulae (I) and (IIa) to (IIf) above, and wherein in formula (II), M 2 is hydrogen, or 1/q equivalent of an q-valent metal ion or is an ammonium ion or a heterocycylium cation, a guanidinium ion or a primary, secondary, tertiary or quarternary organic ammonium ion, in particular those of formula [N(C 1 -C 18 -alkyl) s H t ] + , wherein s is 1, 2 or 3 and t is (4-s), and whereby the reaction if M 2 is hydrogen is carried out in the presence of a base. DETAILED DESCRIPTION In an embodiment, where M 2 is 1/q equivalent of an q-valent metal ion or a quarternary organic ammonium ion or a heterocyclylium cation, an acid, an acid with a pKa of 5 or less at 25° C. measured in water or an aqueous reference system can, for example, be added after the reaction to protonate the intermediates. The compounds of formula (I) may be further functionalized by standard operations such as alkylations, nucleophilic substitutions, protonations with acids, deprotonations with bases, optionally followed by ion exchange and the like in order to obtain other compounds of formula (I). Further details are given in the examples. The scope of the present invention encompasses all combinations of substituent definitions, parameters and illustrations set forth above and below, either in general or within areas of examples or embodiments, with one another, i.e., also any combinations between the particular areas. Whenever used herein the terms “including”, “e.g.”, “such as” and “like” are meant in the sense of “including but without being limited to” or “for example without limitation”, respectively. As used herein, and unless specifically stated otherwise, aryl denotes carbocyclic aromatic substituents, whereby said carbocyclic, aromatic substituents are unsubstituted or substituted by up to five identical or different substituents per cycle. The substituents can, for example, be selected from the group consisting of fluorine, bromine, chlorine, iodine, nitro, cyano, formyl or protected formyl, hydroxyl or protected hydroxyl, C 1 -C 8 -alkyl, C 1 -C 8 -haloalkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -haloalkoxy, C 6 -C 14 -aryl, in particular phenyl and naphthyl, di(C 1 -C 8 -alkyl)amino, (C 1 -C 8 -alkyl)amino, CO(C 1 -C 8 -alkyl), OCO(C 1 -C 8 -alkyl), NHCO(C 1 -C 8 -alkyl), N(C 1 -C 8 -alkyl)CO(C 1 -C 8 -alkyl), CO(C 6 -C 14 -aryl), OCO(C 6 -C 14 -aryl), NHCO(C 6 -C 14 -aryl), N(C 1 -C 8 -alkyl)CO(C 6 -C 14 -aryl), COO—(C 1 -C 8 -alkyl), COO—(C 6 -C 14 -aryl), CON(C 1 -C 8 -alkyl) 2 or CONH(C 1 -C 8 -alkyl), CO 2 M, CONH 2 , SO 2 NH 2 , SO 2 N(C 1 -C 8 -alkyl) 2 , SO 3 M, and PO 3 M 2 . In an embodiment of the present invention, the carbocyclic, aromatic substituents can, for example, be unsubstituted or substituted by up to three identical or different substituents per cycle selected from the group consisting of fluorine, chlorine, cyano, C 1 -C 8 -alkyl, C 1 -C 8 -haloalkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -haloalkoxy, C 6 -C 14 -aryl, in particular phenyl. In an embodiment of present invention, the carbocyclic, aromatic substituents can, for example, be unsubstituted or substituted by up to three identical or different substituents per cycle selected from the group consisting of fluorine, C 1 -C 8 -alkyl, C 1 -C 8 -perfluoroalkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -perfluoroalkoxy, and phenyl. The definitions given above, including areas within examples, also apply analogously to aryldiyl and aryl-n-yl substituents. Aryl substituents can, for example, be C 6 -C 14 -aryl substituents, for example, phenyl, naphthyl, phenanthrenyl and anthracenyl. The term C 6 -C 14 indicates that the number of carbon atoms of the respective carbocyclic, aromatic ring system is from 6 to 14. The possible and examples of substitution patterns mentioned above are likewise applicable. As used herein and unless specifically stated otherwise, heterocyclyl denotes heterocyclic aliphatic, aromatic or mixed aliphatic and aromatic substituents in which no, one, two or three skeleton atoms per cycle, but at least one skeleton atom in the entire cyclic system is a heteroatom selected from the group consisting of nitrogen, sulphur and oxygen which are unsubstituted or substituted by up to five identical or different substituents per cycle, whereby the substituents are selected from the same group as given above for carbocyclic aromatic substituents including the areas of examples. Heterocyclyl-substituents and heteroaryl-substituents respectively, can, for example, be pyridinyl, oxazolyl, thiophen-yl, benzofuranyl, benzothiophen-yl, dibenzofuranyl, dibenzothiophenyl, furanyl, indolyl, pyridazinyl, pyrazinyl, imidazolyl, pyrimidinyl and quinolinyl, either unsubstituted or substituted with one, two or three substituents selected from the group consisting of fluorine, C 1 -C 8 -alkyl, C 1 -C 8 -perfluoroalkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -perfluoroalkoxy, and phenyl. The definitions given above, including their example areas, also apply analogously to heterocyclylium and heteroarylium cations and the bivalent heterocyclo-diyl and heteroaryldiyl substituents. Heterocyclylium cations can, for example, be N—(C 1 -C 8 -alkyl)imidazolium or pyridinium cations. As used herein, and unless specifically stated otherwise, protected formyl is a formyl substituent which is protected by conversion to an aminal, acetal or a mixed aminal acetal, whereby the aminals, acetals and mixed aminal acetals are either acyclic or cyclic. Protected formyl is, for example, 1,1-(2,4-dioxycyclopentanediyl). As used herein, and unless specifically stated otherwise, protected hydroxyl is a hydroxyl radical which is protected by conversion to a ketal, acetal or a mixed aminal acetal, whereby the aminals, acetals and mixed aminal acetals are either acyclic or cyclic. A specific example of protected hydroxyl is tetrahydropyranyl (O-THP). As used herein, and unless specifically stated otherwise, alkyl, alkanediyl, alkenyl, alkenediyl, alkane-n-yl and alkene-n-yl are straight-chained, cyclic either in part or as a whole, branched or unbranched. The term C 1 -C 18 -alkyl indicates that the straight-chained, cyclic either in part or as a whole, branched or unbranched alkyl substituent contains from 1 to 18 carbon atoms excluding the carbon atoms of optionally present substituents to the C 1 -C 18 -alkyl substituent. The same analogously applies to alkanediyl, alkenyl, alkenediyl, alkane-n-yl and alkene-n-yl and further substituents having an indicated number of carbon atoms. For the avoidance of doubt, the term alkenyl denotes a substituent comprising at least one carbon-carbon double bond, irrespective of its location within the straight-chained, cyclic either in part or as a whole, branched or unbranched substituent. Specific examples of C 1 -C 4 -alkyl are methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl. Additional examples for C 1 -C 8 -alkyl are n-pentyl, cyclohexyl, n-hexyl, n-heptyl, n-octyl, isooctyl. Additional examples for C 1 -C 18 -alkyl are norbornyl, adamantyl, n-decyl, n-dodecyl, n-hexadecyl, n-octadecyl. Specific examples of C 1 -C 8 -alkanediyl-substituents are methylene, 1,1-ethylene, 1,2-ethylene, 1,1-propylene, 1,2-propylene, 1,3-propylene, 1,1-butylene, 1,2-butylene, 2,3-butylene and 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,1-cyclohexylene, 1,4-cyclohexylene, 1,2-cyclohexylene and 1,8-octylene. Specific examples of C 1 -C 4 -alkoxy-substituents are methoxy, ethoxy, isopropoxy, n-propoxy, n-butoxy and tert-butoxy. An additional example for C 1 -C 8 -alkoxy is cyclohexyloxy. Specific examples of C 2 -C 18 -alkenyl and C 2 -C 8 -alkenyl-substituents are allyl, 3-propenyl and buten-2-yl. As used above, C 1 -C 8 -haloalkyl and C 1 -C 8 -haloalkoxy are C 1 -C 8 -alkyl and C 1 -C 8 -alkoxy substituents which are once, more than once or fully substituted by halogen atoms. Substituents which are fully substituted by fluorine are referred to as C 1 -C 8 -perfluoroalkyl and C 1 -C 8 -perfluoroalkoxy, respectively. Specific examples of C 1 -C 8 -haloalkyl-substituents are trifluoromethyl, 2,2,2-trifluoroethyl, chloromethyl, fluoromethyl, bromomethyl, 2-bromoethyl, 2-chloroethyl, nonafluorobutyl and n-perfluorooctyl. The process according to the present invention requires employment of compounds of formula (III). Such compounds may be prepared in any manner known per se, for example, by the steps of: A) contacting elemental phosphorous with a alkali or alkaline earth metal optionally in the presence of a catalyst or an activator in a solvent to obtain metal phosphides M 3 3 P, wherein M 3 is an alkali or ½ equivalent of an alkaline earth metal, whereby the phosphides are usually present in a polymeric form and are therefore occasionally referred to as pholyphosphides, B) optionally adding a proton source, optionally in the presence of a catalyst or an activator to obtain metal dihydrogen phosphides M 3 PH 2 which may depending on the proton source exist as complexes, C) reacting said dihydrogenphosphides with either, two equivalents of acid halides of formula (VI) to obtain compounds of formula (III) wherein m is 2, or first with one equivalent of acid halide of formula (VI), and subsequently with one equivalent of formula (VII) LG-R 3   (VII) or vice versa, to obtain compounds of formula (III) wherein m is 1, and to the extent M 3 differs from M 2 further reaction with either metal salts of formula (VIII), M 2 Hal q   (VIII), wherein q denotes the valence of the metal ion M 2 , or acids of formula (IX) HAn  (IX), wherein An is 1/p equivalent of a p-valent anion, whereby in formulae (III), (IV), (V), (VI), (VII) and (VIII), R 2 , R 3 , m and M 2 have the same meaning given above for formula (I), and LG denotes a leaving group, for example, chlorine, bromine or iodine or C 1 -C 8 -alkylsulfonyloxy. Alternatively, compounds of formula (III) with m=1 are prepared, for example, by the step of contacting phosphines H 2 PR 3 , with one equivalent of acid halide of formula (VI) in the presence of two equivalents of a base or by contacting phosphides M 3 HPR 3 , with one equivalent of acid halide of formula (VI) and to the extent M 3 differs from M 2 further reaction with either metal salts of formula (VIII), whereby in formulae (III), (IV), (V), (VI), (VII) and (VIII) R 2 , R 3 , m and M 2 have the same meaning given above for formula (I) and LG denotes a leaving group, for example, chlorine, bromine or iodine or C 1 -C 8 -alkylsulfonyloxy. For the avoidance of doubt, compounds of formula (III) as depicted above shall also encompass their isomers of formulae (IIIa), (IIIb) and (IIIc) which are typically present and observable in solution and solid state: Formula (III) as depicted above shall also encompass dimers, trimers and higher aggregated complexes as well as solvate complexes or other compounds, wherein the Metal is complexed of the compounds depicted therein, and the isomers of formulae (IIIa), (IIIb) and (IIIc) which are typically present and observable in solution and solid state. In an embodiment of the present invention, in compounds of formulae (IVa) and (I), with R 1 being a substituent of formula (IIa) n is 1 and m is 1 or 2, for example, 2 and Z is a substituent selected from the group consisting of —CN, —(CO)R 8 , —(CO)OR 8 , —(CO)N(R 8 ) 2 , —(SO 2 )R 8 , —(PO)(R 8 ) 2 , —(PO)(OR 8 ) 2 , —(PO)(OR 8 )(R 8 ), or 2-pyridyl R 6 and R 7 independently of each other, are hydrogen, Z or R 8 , and R 8 independently of further substituents R 8 which may be present in the substituent of formula (IIa) is C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl or C 6 -C 14 -aryl or two substituents R 8 irrespective of whether they are both part of a substituent Z or belong to different substituents selected from Z, R 6 and R 7 together are C 1 -C 4 -alkanediyl or C 2 -C 4 -alkenediyl, or alternatively, where two substituents —(CO)R 8 are present within the substituent of formulas (IIa), are together —O— or —NR 4 —, whereby the C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkanediyl and C 2 -C 4 -alkenediyl substituents are either not, or once interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —CO—, —O(CO)—, (CO)O— or —O(CO)O—, and, either not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: oxo, hydroxy, halogen, cyano, C 6 -C 14 -aryl, C 1 -C 4 -alkyl, C 1 -C 4 -alkoxy, C 2 -C 4 -alkenyl, PO(OR 5 ) 2 , —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —Si(OR 5 ) y (R 5 ) 3-y , —OSi(OR 5 ) y (R 5 ) 3-y with y=1, 2 or 3, and, for example, also —N(R 4 ) 3 + An − . In an embodiment of the present invention, in compounds of formulae (IVa) and (I), with R 1 being a substituent of formula (IIa), n is 1 and m is 1 or 2, for example, 2, and Z is a substituent selected from the group consisting of —CN, —(CO)R 8 , —(CO)OR 8 , —(CO)N(R 8 ) 2 , —(SO 2 )R 8 , —(PO)(R 8 ) 2 , —(PO)(OR 8 ) 2 , or 2-pyridyl, R 6 is hydrogen, R 7 is hydrogen, Z or R 8 , and R 8 independently of further substituents R 8 which may be present in the substituent of formula (IIa) is C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl or two substituents R 8 irrespective of whether they are both part of a substituent Z or belong to different substituents selected from Z, R 6 and R 7 together are C 1 -C 4 -alkanediyl or C 2 -C 4 -alkenediyl or alternatively, where two substituents —(CO)R 8 are present within the substituent of formulas (IIa), are together —O— or —NR 4 —, whereby the C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkanediyl and C 2 -C 4 -alkenediyl substituents are either not, or once interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —CO— and, either not, additionally or alternatively once, twice or more than twice substituted by substituents selected from the group consisting of: oxo, hydroxy, C 1 -C 4 -alkoxy, C 2 -C 4 -alkenyl, PO(OR 5 ) 2 , —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —Si(OR 5 ) y (R 5 ) 3-y , —OSi(OR 5 ) y (R 5 ) 3-y with y=1, 2 or 3, and, for example, also —N(R 4 ) 3 + An − , In an embodiment of the present invention, in compounds of formulae (IVa) and (I), with R 1 being a substituent of formula (IIa) n is 1 and m is 1 or 2, for example, 2, and Z is a substituent selected from the group consisting of —CN, —(CO)OR 8 , —(SO 2 )R 8 , —(PO)(R 8 ) 2 , —(PO)(OR 8 ) 2 , or 2-pyridyl, R 6 is hydrogen, R 7 is hydrogen, Z or Methyl, and R 8 independently of further substituents R 8 which may be present in the substituent of formula (IIa) is C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, or two substituents R 8 irrespective of whether they are both part of a substituent Z, or belong to different substituents selected from Z, R 6 and R 7 together are C 1 -C 4 -alkanediyl or C 2 -C 4 -alkenediyl, or alternatively, where two substituents —(CO)R 8 are present within the substituent of formulas (IIa), are together —O— or —NR 4 —, whereby the C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkanediyl and C 2 -C 4 -alkenediyl substituents are either not or once interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, and, either not, additionally, or alternatively once, twice or more than twice substituted by substituents selected from the group consisting of: hydroxy, C 1 -C 4 -alkoxy, C 2 -C 4 -alkenyl, PO(OR 5 ) 2 , —N(R 4 ) 2 , —CO 2 N(R 5 ) 2 , —Si(OR 5 ) y (R 5 ) 3-y , —OSi(OR 5 ) y (R 5 ) 3-y with y=1, 2 or 3, and, for example, also —N(R 4 ) 3 + An − , In an embodiment of the present invention, the following compounds of formulae (IVa) are used: C 1 -C 8 -alkyl esters of acrylic acid or methacrylic acid whereby C 1 -C 8 -alkyl is unsubstituted or substituted according to the substitution pattern described above, for example, methyl-, ethyl-, n-butyl-, iso-butyl, tert.-butyl-, 2-ethylhexyl- and 2-hydroxyethyl acrylate, isobornyl acrylate, 3-(acryloyloxy) propyltrimethoxy-silane, 2-acryloxyethyltrimethylammoniumchloride, α-unsaturated sulfones such as phenylvinyl sulfone, α-unsaturated lactones such as α-methylene-γ-butyrolactone, α-unsaturated C 1 -C 8 -alkyl phosphonates compounds such as diethyl vinylphosphonate, aromatic compounds such as 2- and 4-vinylpyridine, nitriles such as acrylonitrile, C 1 -C 8 -alkyl esters of other unsaturated acids such as crotonic acid, maleic acid, fumaric acid, itaconic acid and cinnamic acid whereby C 1 -C 8 -alkyl is unsubstituted or substituted according to the substitution pattern described above, anhydrides of maleic acid and itaconic acid, and the respective compounds of formula (I) are those obtainable by the respective reaction of compounds of formula (IVa) with compounds of formula (III). In an embodiment of the present invention, the following compounds of formulae (IVa) are used: Itaconic anhydride, maleimide, acrylonitrile, α-methylene-γ-butyrolactone, phenyl vinyl sulfone, diethyl vinylphosphonate, methylacrylate, 3-(acryloyloxy)propyltrimethoxy-silane, dimethyl itaconate, vinyl acrylate, 2-vinylpyridine, 2-acrylamido-2-hydroxymethyl-1,3-propanediol. In an embodiment of the present invention, compounds of formulae (IVb) and (I), with R 1 being a substituent of formula (IIb) R 6 is hydrogen, R 8 is C 1 -C 8 -alkyl; and An− is a halide. An example of a compound of formula (IVb) is N,N-dimethylmethyleneiminium chloride. In an embodiment of the present invention, compounds (IVc) and (I), with R 1 being a substituent of formula (IIc) R 6 is C 1 -C 8 -alkyl or C 6 -C 14 -aryl and R 8 is C 1 -C 8 -alkyl or C 6 -C 14 -aryl. In an embodiment of the present invention, compounds of formulae (IVd) and (I), with R 1 being a substituent of formula (IId) R 8 , is C 1 -C 8 -alkyl, C 2 -C 8 -alkyl or C 6 -C 14 -aryl. An example of a compound of formula (IVd) is cyclohexylisocyanate. In an embodiment of the present invention, in compounds of formulae (IVe) and (I), with R 1 being a substituent of formula (IIe) n is 2 and m is 1 or 2, for example, 2, and R* is —CO— or —SO 2 —, for example, —SO 2 —, and R 9 independently of each other are hydrogen, C 1 -C 8 -alkyl, or two substituents R 9 irrespective of whether they are both bound to C (2) or not are together C 2 -C 8 -alkanediyl, for example, all substituents R 9 are hydrogen. One specific compound of formula (IVe) is divinylsulfone. In an embodiment of the present invention, in compounds of formulae (I), with R 1 being a substituent of formula (IIa) or (IIe) m is 1 or 2, for example, 2, and R* is a substituent of formula (VIa) or (VIb) or (VIc) or (VId) or (VIe) wherein, in formula (VIa) n is 1, 2, 3 or 4, in formula (VIb) n is 1, 2 or 3, in formula (VIc) and VI(d) n is 1 or 2, in formula (VIe) n is 1, and wherein, n of the substituents R 11 are —C (1) H 2 —C (2) HR 15 —(C═O)— wherein (1) indicates the numeration of the carbon atom whereby each of the n C (1) carbon atoms is bound to the central phosphorous atom depicted in formula (I) and R 11 is bound to X at the carbonyl carbon and wherein R 15 is hydrogen or methyl, and the remainder substituents R 11 , if any, are either hydrogen or C (1) H 2 ═C (2) HR 15 —(C═O)—, each X is independently selected from the group consisting of —OCH 2 —CH 2 —, —OCH(CH 3 )—CH 2 —, —OCH 2 —CH(CH 3 )—, —OCH 2 —C(CH 3 ) 2 —, —O—C(CH 3 ) 2 —CH 2 —, and u, v, w and z are independently selected from 0 or an integer from 1 to 20, for example, 0 or an integer from 1 to 10, for example, zero or an integer from 1 to 5. In an embodiment of the present invention, u, v, w and z are all 0, zz is selected from an integer of from 1 to 100, for example, an integer of from 2 to 100, for example, an integer of from 3 to 20, R 12 and R 13 are independently selected from the group consisting of hydrogen or C 6 -C 14 -aryl or C 1 -C 18 -alkyl, R 14 is C 2 -C 18 -alkane-diyl or X 2 wherein X 2 is independently selected from the group consisting of —CHR 16 —CH 2 —(O—CHR 16 —CH 2 —) f —O—(CHR 16 CH 2 )—, —CH 2 —CHR 16 —(O—CH 2 —CHR 16 —) f —O—(CHR 16 CH 2 )—, with f being 0 or an integer of 1 to 20 and R 16 being methyl or hydrogen, R 30 is selected from the group consisting of hydrogen or C 6 -C 14 -aryl or C 1 -C 18 -alkyl, for example, hydrogen, methyl, ethyl, n-propyl, isopropyl, tert.-butyl and phenyl. Compounds of formulae (VIa) to (VIe) may be obtained by reacting the compounds of formulae (VIIa) to (VIIe) with compounds of formula (III): wherein, the substituents R 17 are each independently, for example, identically selected from the group consisting of hydrogen or C (1) H 2 ═C (2) HR 15 —(C═O)—. Specific compounds of formula (VIIa) are mono-, di-, tri- or tetraacrylated or -methacrylated pentaerythrol or mixtures thereof or their ethoxylated or propoxylated or mixed ethoxylated and propoxylated analogoues. Specific compounds of formula (VIIb) are mono-, di- or tri-acrylated or -methacrylated trimethylolpropane or mono-, di- or tri-acrylated or -methacrylated glycerol or mixtures thereof or their ethoxylated or propoxylated or mixed ethoxylated and propoxylated analogoues. Further examples include 1,3-propanedioldiacrylate and 1,3-butanedioldiacrylate. Specific compounds of formula (VIIc) are, 1,3-butanedioldiacrylate, 1,5-pentanedioldiacrylate, 1,6-hexanedioldiacrylate, glyceroldi- or -triacrylate, di- or polyacrylates of sugar alcohols such as sorbitol, mannitol, diglycerol, threitol, erythrol polyethylenglycols, epoxy(meth)acrylates, urethane(meth)acrylates, and polycarbonate(meth)acrylates. Specific compounds of formula (VIId) are 1,2-propanedioldiacrylate, 1,4-butanedioldiacrylate, 1,5-pentanedioldiacrylate, 1,6-hexanedioldiacrylate, mono, di- or polyacrylates of sugar alcohols such as sorbitol, mannitol, diglycerol, threitol, erythrol polyethylenglycols. Specific compounds of formula (VIIe) are acrylic or methacrylic esters of monomethyl or monoethylethers of polyethylene glycols or polypropylene glycols wherein zz is an integer of 2 to 100, for example, 3 to 20. Compounds of formulae (VIa) to (VId) are particularly useful as multifunctional photoinitiators having highly valuable crosslinking and bonding capabilities which were not known before. Compounds of formulae (VIa) to (VId) where at least one of u, v, z, and y is not zero and those compounds of formula (VIe) are particularly useful as photoinitiators having (in addition thereto) high efficiency as well as good emulsifying capabilities which allows to use them as photoinitiators in emulsion polymerizations with superior performance. In an embodiment of the present invention, in compounds of formulae (I) and (III), m is 1 or 2, for example, 2, and R 2 is C 6 -C 14 -aryl or heterocyclyl, or is C 1 -C 18 -alkyl or C 2 -C 18 -alkenyl which is either not, once, twice or more than twice interrupted by non-successive functional groups selected from the group consisting of: —O—, —NR 4 —, —N + (R 4 ) 2 An − -, —CO—, NR 4 (CO)—, —NR 4 (CO)O—, (CO)NR 4 —, and which is not, additionally or alternatively either once, twice or more than twice substituted by substituents selected from the group consisting of: halogen, cyano, C 6 -C 14 -aryl; heterocyclyl, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio, C 2 -C 8 -alkenyl, C 4 -C 15 -arylalkyl, —COOM, SO 2 N(R 3 ) 2 —, N(R 4 ) 2 —, —N + (R 4 ) 3 An − , —CO 2 N(R 4 ) 2 , whereby R 4 is independently selected from the group consisting hydrogen, C 1 -C 8 -alkyl, C 6 -C 14 -aryl, C 7 -C 15 -arylalkyl and heterocyclyl or N(R 4 ) 2 as a whole is a N-containing heterocycle or N + (R 4 ) 2 An − and N + (R 4 ) 3 An − as a whole is or contains a cationic N-containing heterocycle with a counteranion, R 5 is independently selected from the group consisting C 1 -C 8 -alkyl, C 6 -C 14 -aryl, C 7 -C 15 -arylalkyl and heterocyclyl or N(R 5 ) 2 as a whole is a N-containing heterocycle or N + (R 5 ) 2 An − and N + (R 5 ) 3 An − as a whole is or contains a cationic N-containing heterocycle with a counteranion, M is hydrogen, lithium, sodium, potassium, one half equivalent of calcium, zinc or iron (II), or one third equivalent of aluminium (III) or is an ammonium ion or a primary, secondary, tertiary or quarternary organic ammonium ion, and An − is 1/p equivalent of an p-valent anion. In an embodiment of the present invention, in compounds of formulae (I) and (III), m is 2, R 2 is C 6 -C 14 -aryl, for example, mesityl or 2,6-dimethoxyphenyl. In an embodiment of the present invention, in compounds of formula (I), M 2 is hydrogen or sodium. The process is typically carried out by adding the compounds of formulae (IVa) to (IVf) either neat or dissolved or suspended in a solvent to a neat compound of formula (III) or a solution or suspension thereof and, where M 2 is hydrogen, the base. A reaction mixture is thereby formed. The process is alternatively carried out by adding the compound of formula (III) either neat or dissolved or suspended in a solvent and, where M 2 is hydrogen, the base to a neat compound of formula (IVa) to (IVf) or a solution or suspension thereof. A reaction mixture is thereby formed. The reaction time is typically in the range of from 5 min to 24 hours, for example, 30 min to 12 hours. Suitable solvents are those which do not or virtually not react under formation of new covalent bonds with the compounds of formulae (III) and (IVa) to (IVf) employed in the reaction. Such solvents include: aromatic solvents such as benzene, toluene and the isomeric xylenes, ethers such as diethylether, methyl tert.butyl ether, tetrahydrofurane, dioxane, dimethoxyethane, diethoxyethan and higher glycolethers, C 1 -C 8 mono-, di- or trialcohols or ether alcohols such as methanol, ethanol, n-propanol, isopropanol, glycerol, glycol, 1,4-butanediol, diethyleneglycol or triethyleneglycol, amides such as dimethylformamide, sulfones such as tetraethylensulfone, esters such as ethylacetate, and water, or mixtures of the aforementioned solvents. It is quite surprising that the reaction can be carried out in water since this allows the process to be performed in an environmentally-friendly manner. The amount of solvent is not critical and is only limited by commercial aspects, since they must be removed if the compounds shall finally be isolated. The amount of solvent is typically chosen so that the final product is completely soluble in the organic solvent. To facilitate the reaction mixing energy is introduced into the reaction mixture, e.g., by standard agitators stirrers and/or by static mixing elements. Even though not necessary, mixing can also be supported by using high force dispersion devices such as, for example, ultrasound sonotrodes or high pressure homogenizers. The process may either be performed batchwise or continuously. A typical reaction temperature range to carry out the process is from −30° C. to 120° C., for example, from −10 to 80° C., and for example, from 0 to 40° C. It is evident to those skilled in the art, that where the desired reaction temperature is above the boiling point at 1013 hPa of the solvent employed, the reaction is carried out under sufficient pressure. A typical reaction pressure range to carry out the process can, for example, be from 50 hPa to 10 MPa, for example, from 500 hPa to 1 MPa, and for example, from 800 hPa to 1.2 MPa. The reaction can, for example, be carried out under ambient pressure. During the reaction compounds of formula (I) are formed. If M 2 is 1/q equivalent of an q-valent metal ion or a quarternary organic ammonium ion or a heterocyclylium cation salts of compounds of formula (I) are formed which are also covered by the present invention. In this case an acid is added after the reaction to obtain compounds of formula (I). Suitable acids are those having a pKa of 7 or less, for example, 5 or less, for example, 2 or less at 25° C. measured in water. Examples of suitable acids include hydrogen chloride in diethylether, sulphuric acid, carboxylic acids such as formic acid and acetic acid. If M 2 is hydrogen the reaction is carried out in the presence of base. Where in addition to compounds of formula (III) where M 2 is hydrogen further compounds of formula (III) are used where M 2 is not hydrogen, the latter compounds can serve as a base without the necessity to add other bases The amount of base is not critical and might be in the range of from 0.0001 to 100 mol equivalents with respect to the compounds of formula (III), for example, in the range of from 0.001 to 10 mol equivalents, for example, in the range of from 0.05 to 1 mol equivalents, for example, in the range of from 0.05 to 0.5 mol equivalents. Suitable bases include Ammonia, primary, secondary or tertiary amines such as triethylamine, triethanolamine and DBN, N-heteroaromatic compounds such as unsubstituted or substituted pyridines or chinolines, alcoholates such as lithium-, sodium- and potassium-methoxide, -ethoxide and -tert. butoxide, amides such as lithium-diisoproylamide, hydroxides such as lithium, sodium and potassium hydroxide and carbonates such as lithium, sodium and potassium carbonate. The carbonates and hydroxides can, for example, be employed when water is used as solvent. In an embodiment of the present invention, the bases are removed after reaction from the reaction mixture by adding an acid, for example, those acids as defined above, and removing the salts formed thereby by sedimentation and decanting, filtration or centrifugation. The molar ratio of compounds of formula (IVa) to (IVe) to those of formula (III) depends on the integer n, i.e. the number of acylphosphino groups to be finally present in compounds of formula (I). Typically from 0.8 to 1.2 mol of compounds of formula (III) are employed per acylphosphino group to be introduced, for example, 0.9 to 1.0 mol. Most of the compounds obtained by the reaction according to the present invention are novel. One further aspect of the present invention therefore relates to the novel compounds of formula (I) with compounds: tert.-butyl 3-(bis(2,4,6-dimethoxybenzoyl)phosphino)propanoate, 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanitrile, and 2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl-diethylphosphonate, being excluded since they have previously been described in WO 2006/056541. The substitution pattern disclosed above for compounds of formula (I) also applies here. Specific examples include: 3-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-dihydrofuran-2,5-dione, 3-(bis(2,4,6-trimethylbenzoyl)phosphino)pyrrolidine-2,5-dione, 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanenitrile, 3-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-dihydrofuran-2(3H)-one, di-(2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-sulfone, ((bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-phenyl-sulfone, Diethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethylphosphonate, methyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate, 3-(trimethoxysilyl)propyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate, dimethyl 2-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)succinate, vinyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate, N,N-methylene-(bis-(bis(2,4,6-trimethylbenzoyl)phosphino)propanamide), 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-pyridine, (bis(2,4,6-trimethylbenzoyl)phosphoryl)-N-cyclohexylformamide, N-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-N,N-dimethylamine, N-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-N,N,N-trimethylammonium triflate, 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoic acid 2-(2-ethoxyethoxy)ethylester, bis-(3-[2-(2-ethoxyethoxy)ethoxycarbonyl]-propyl-(2,4,6-trimethylbenzoyl)-phosphine, trimethylolpropane tris-[3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate], trimethylolpropane monoacrylate bis-[3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate], trimethylolpropane bisacrylate mono-[3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate], dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)fumarate, dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)maleate, and 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoyl-oxyethyltrimethylammonium chloride. Compounds or formula (I) are particularly useful as precursor materials for compounds of formula (V) wherein, R 1 , R 2 , R 3 , n and m have the same meaning as described for formula (I) above including the same example areas, and X is oxygen or sulphur, for example, oxygen. Most of the compounds of formula (V) are also novel. An aspect of the present invention therefore relates to said compounds of formula (V) with compounds: tert.-butyl 3-(bis(2,4,6-dimethoxybenzoyl)phosphoryl)propanoate, 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanitrile, and 2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl-diethylphosphonate, being excluded since they were previously described in WO 2006/056541. The example substitution pattern disclosed above for compounds of formula (I) applies analogously. Specific examples include: 3-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)-dihydrofuran-2,5-dione, 2-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)succinic acid, 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)pyrrolidine-2,5-dione, 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanenitrile, 3-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)-dihydrofuran-2(3H)-one, di-(2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-sulfone, ((bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-phenyl-sulfone, diethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethylphosphonate, methyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate, 3-(trimethoxysilyl)propyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate, dimethyl 2-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)succinate, vinyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate, N,N-methylene-bis-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanamide), 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-pyridine, 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)-N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)propanamide, (bis(2,4,6-trimethylbenzoyl)phosphoryl)-N-cyclohexylformamide, methyl 3-(phenyl(2,4,6-trimethylbenzoyl)phosphoryl)propanoate, 2-(2-(phenyl-(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-pyridine, di-(2-(phenyl-(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-sulfone, 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoic acid 2-(2-ethoxyethoxy) ethylester, bis-(3-[2-(2-ethoxyethoxy)ethoxycarbonyl]-propyl-(2,4,6-trimethylbenzoyl)-phosphine oxide, trimethylolpropane tris-[3-(bis(2,4,6.trimethylbenzoyl)phosphoryl) propanoate], trimethylolpropane monoacrylate bis-[3-(bis(2,4,6.trimethylbenzoyl)phosphoryl) propanoate], trimethylolpropane bisacrylate mono-[3-(bis(2,4,6.trimethylbenzoyl)-phosphoryl) propanoate], dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)fumarate, dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)maleate, and 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoyl-oxyethyltrimethylammonium chloride. Compounds of formula (V) may be obtained by reaction of compounds of formula (I) with an oxidizing agent to obtain compounds of formula (V), where X is oxygen or a sulfidizing agent to obtain compounds of formula (V), where X is sulphur in a manner well known to those skilled in the art and as e.g., described in WO 2006/056541. Suitable oxidizing agents are: hydrogen peroxide, which can, for example, be employed as aqueous solution, e.g., with 30 wt.-%, organic peroxides such as tert-butylhydroperoxide; oxygen e.g., in the form of air, or sodium hypochlorite. Suitable sulfidizing agents are: elemental sulphur or organic polysulfides. In an embodiment of the present invention, the oxidation or suldidation is carried out in the same reaction media as the process for the preparation of compounds of formula (I), i.e., as a one-pot-reaction. An advantage of the process according to the present invention is that it allows the efficient and high-yielding synthesis of compounds of formulae (I) and (V) with a mild, variety of functional groups which are not easily available via known routes. Compounds of formula (V) are particularly useful as photoinitiators. An aspect of the present invention therefore relates to a photoinitiated polymerization process, in particular, for the polymerization of polymerizable monomers wherein compounds of formula (V) are employed. Such processes are particularly useful for the preparation of polymer nanoparticles, coatings, adhesives, inks and painting materials. The present invention therefore further relates to polymer nanoparticles, coatings, adhesives, inks and painting materials obtainable by such process. The present invention is further illustrated by the examples without being limited thereby. EXAMPLES I Preparation of Precursor Materials 1) Preparation of Sodium bis(mesitoyl)phosphide In a 100 mL thick-walled Schlenk flask equipped with a teflon screw cap, sodium (1.73 g, 0.075 mmol, 3 eq.) and red phosphorus (0.78 g, 0.025 mmol, 1 eq.) were put together under inert conditions. A glass covered magnetic stirrer was added and 20 mL of ammonia were condensed into the flask, by cooling with dry ice/acetone to −78° C. Subsequently, dimethoxyethane (dme) (20 mL) was added and the flask was closed and warmed up to room temperature. After 90 min. stirring at room temperature, a change in color from blue to dark yellow was observed and after another 30 min., the color became intensively yellow. The pressure in the reaction vessel was 7 to 8 bar. The reaction mixture was cooled down to −40° C. The Schlenk flask, which had now a pressure of 1 bar, was opened and tert-butanol (3.71 g, 0.05 mol, 2 eq.) was added. The reaction mixture was warmed up to room temperature over a period of two hours. Finally, the solvent was completely removed in vacuo at room temperature. The remaining oil was dissolved in dme (40 mL). Mesitoyl chloride (9.15 g, 0.05 mol, 2 eq.) was added dropwise. i): Isolation of the product under dry conditions: The reaction mixture was stirred for one hour at room temperature, the precipitate of sodium chloride was removed by filtration, and the solvent was evaporated in vacuo. The pure microcrystalline product can be obtained by dissolving the sodium bis(mesitoyl)phosphide in dme and precipitation with n-hexane (Yield: 5.89 g, 67.7%). ii). Working up with degassed water: The reaction mixture was mixed with 100 mL degassed, distilled water. After stirring, the solution until the sodium chloride was completely dissolved, the reaction mixture was extracted three times with 50 mL of toluene. After removing the toluene in vacuo, the pure product remains. It can contain small amounts of water, which can be completely removed by azeotropic distillation with toluene. The product is dissolved in toluene and the solvent is removed in vacuo afterwards again. This procedure must be repeated two or three times. The yield is the same as for procedure a). m.p.: 208° C. (Decomposition). 31 P NMR (101.25 MHz): δ=84.1 ppm (br.). 2) Preparation of bis(mesitoyl)phosphane (HP(COMes) 2 ) The phosphane was obtained by adding an equimolar amount of hydrochloric acid in ether (2 M) to the compound obtained according to Example 1, filtering off the resulting sodium chloride, and evaporating the solvent in vacuo. 3) Preparation of sodium-mesitoylphenylphosphide The phosphane PhPH 2 was prepared according to the procedure described by Grutzmacher et al. CHIMIA 2008, 62, No. 1/2. A solution of PhPH 2 (0.38 mL, 3.46 mmol) and NaO t Bu (0.67 g, 6.92 mmol, 2 eq.) in toluene (10 mL) was prepared in a 50 mL Schlenk flask under an argon atmosphere. Subsequently, mesitoyl chloride (0.58 mL, 3.46 mmol, 1 eq.) was added dropwise to the solution at 0° C. The reaction mixture was allowed to warm to room temperature and stirred for 2 h, the precipitate of sodium chloride was removed by filtration and the solvent was removed in vacuo to yield a pale yellow solid (0.79 g, 2.84 mmol, 82%). 31 P{ 1 H} NMR (101.3 MHz, C 6 D 6 , 298 K): δ=49.8 ((E)-isomer), 83.1 ((Z)-isomer) ppm. II Preparation of Acylphosphanes and Their Oxides General Method for the Preparation of Acylphosphanes Starting from Phosphines and Phosphides A solution of the phosphane or phosphide and optionally triethylamine in either dimethoxyethane (dme) or tetrahydrofurane (thf) was prepared in a 50 mL Schlenk flask under an inert atmosphere of argon (first solution). Subsequently, a solution of a compound selected from those of formulae (IVa) to (IVe) in dme or thf or the neat compound (hereinafter collectively referred to as second solution) was slowly added. After stirring for twelve hours at room temperature, a 2M solution of hydrochloric acid in diethylether was added in an equimolar amount to neutralize the triethylamine. The reaction mixture was stirred for another hour at room temperature, before the solvent was removed under reduced pressure. The solid residue was dissolved in toluene and the insoluble precipitate of triethylamine hydrochloride was separated by filtration. The solution volume was reduced in vacuo to half of its volume and layered with half of the remaining volume of hexane. The obtained crystalline solid was collected and dried under high vacuum for twelve hours. General Method for the Preparation of Acylphosphane Oxides The oxidant was added to a solution of the acylphosphane in toluene and the reaction mixture vigorously stirred at room temperature for twelve hours under an inert atmosphere (argon) and exclusion of light in a 50 mL Schlenk flask. The solvent was thereafter removed under reduced pressure. The resulting product was recrystallized from a polar solvent layered with a non polar solvent and storage at −15° under exclusion of light. The precipitate was collected by filtration and dried under vacuum for twelve hours. 4a) 3-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-dihydrofuran-2,5-dione First solution: HP(COMes) 2 (3 g, 9.19 mmol) and triethylamine (0.92 mmol) in dme (20 mL) Second solution: itaconic anhydride (1.03 g, 9.19 mmol) in dme (10 mL) Amount of toluene: 40 Ml Yield: 3.87 g, 96% th. 31 P{ 1 H} NMR (121.5 MHz, C 6 D 6 , 298 K): δ=48.7 ppm 4b) 3-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)-dihydrofuran-2,5-dione Acylphosphane: 1.019 g (2.32 mmol) of compound obtained according to Example 4a Amount of toluene: 15 ml Oxidant: tert-butyl hydroperoxide (0.465 mL, 1.1 eq., 2.56 mmol, 5.5M in decane) Recrystallization: from 7 mL toluene layered with hexane (2 mL) Yield: 0.85 g, 81% th. 31 P{ 1 H} NMR (81 MHz, C 6 D 6 , 298 K): δ=22.5 ppm 4c) 2-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)succinic acid Acylphosphane: 1.58 g (3.60 mmol) of compound obtained according to Example 4a Amount of toluene: 20 ml Oxidant: aqueous hydrogen peroxide (0.82 mL, 2.2 eq., 7.93 mmol, 30%) Recrystallization: from 35 mL diethyl ether layered with hexane (2 mL) Yield: 1.53 g, 90% th. 31 P{ 1 H} NMR (121.5 MHz, C 6 D 6 , 298 K): δ=24.0 ppm 5a) 3-(bis(2,4,6-trimethylbenzoyl)phosphino)pyrrolidine-2,5-dione First solution: HP(COMes) 2 (0.5 g, 1.53 mmol) and triethylamine (0.15 mmol) in dme (3 mL) Second solution: maleimide (149 mg, 1.53 mmol) in dme (2 mL) Amount of toluene: 20 mL Yield: 0.63 g, 97% th. 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=71.7 ppm 5b) 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)pyrrolidine-2,5-dione Acylphosphane: 500 mg (1.18 mmol) of compound obtained according to Example 5a Amount of toluene: 10 ml Oxidant: tert-butyl hydroperoxide (0.24 mL, 1.1 eq., 1.30 mmol, 5.5M in decane) Recrystallization: none, but washing with hexane (3×7 mL) Yield: 0.475 g, 92% th. 31 P{ 1 H} NMR (202.5 MHz, d8-thf, 298 K): δ=25.2 ppm 6a) 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanenitrile First solution: HP(COMes) 2 (0.5 g, 1.53 mmol) and triethylamine (0.15 mmol) in dme (5 mL) Second solution: neat acrylonitrile (0.1 mL, 1.53 mmol) Amount of toluene: 7 mL Yield: 0.57 g, 99% th. 31 P NMR (162 MHz, d8-thf, 298 K): δ=49.9 ppm (t, 2 J PH =11.91 Hz) 6b) 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanenitrile Acylphosphane: 418 mg (1.10 mmol) of compound obtained according to Example 6a Amount of toluene: 5 ml Oxidant: aqueous hydrogen peroxide (0.13 mL, 1.1 eq., 1.21 mmol, 30%) Recrystallization: from 10 mL toluene layered with hexane (5 mL) Yield: 0.37 g, 85% th. 31 P{ 1 H} NMR (202.5 MHz, C 6 D 6 , 298 K): δ=23.3 ppm 7a) 3-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-dihydrofuran-2(3H)-one First solution: HP(COMes) 2 (3 g, 9.19 mmol) and triethylamine (0.92 mmol) in dme (30 mL) Second solution: neat α-methylene-γ-butyrolactone (0.805 mL, 9.19 mmol) Amount of toluene: 40 mL Yield: 3.71 g, 95% th. 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=49.1 ppm 7b) 3-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)-dihydrofuran-2(3H)-one Acylphosphane: 1.118 g (2.63 mmol) of compound obtained according to Example 7a Amount of toluene: 10 ml Oxidant: tert-butyl hydroperoxide (0.53 mL, 1.1 eq., 2.90 mmol, 5.5M in decane) Recrystallization: from 4 mL toluene layered with hexane (3 mL) Yield: 0.95 g, 82% th. 31 P{ 1 H} NMR (202.5 MHz, C 6 D 6 , 298 K): δ=25.6 ppm 8a) di-(2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-sulfone First solution: HP(COMes) 2 (1.455 g, 4.46 mmol) and triethylamine (0.45 mmol) in dme (15 mL) Second solution: neat divinylsulfone (0.223 mL, 2.23 mmol) Amount of toluene: 40 mL Yield: 3.4 g, 99% th. 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=53.3 ppm 8b) di-(2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-sulfone Acylphosphane: 1.257 g (1.63 mmol) of compound obtained according to Example 8a Amount of toluene: 15 ml Oxidant: aqueous hydrogen peroxide (0.37 mL, 2.2 eq., 3.59 mmol, 30%) Recrystallization: none, but washing with hexane (3×7 mL) Yield: 1.25 g, 96% th. 31 P{ 1 H} NMR (162 MHz, C 6 D 6 , 298 K): δ=23.0 ppm 9a) ((bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-phenyl-sulfone First solution: HP(COMes) 2 (0.5 g, 1.53 mmol) and triethylamine (0.15 mmol) in dme (3 mL) Second solution: phenyl vinyl sulfone (258 mg, 1.53 mmol) in dme (2 mL) Amount of toluene: 20 mL Yield: 0.71 g, 94% th. 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=50.0 ppm 9b) ((bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-phenyl-sulfone Acylphosphane: 0.31 g (0.63 mmol) of compound obtained according to Example 9a Amount of toluene: 5 ml Oxidant: aqueous hydrogen peroxide (0.071 mL, 2.2 eq., 0.69 mmol, 30%) Recrystallization: none, but washing with hexane (3×5 mL) Yield: 0.29 g, 90% th. 31 P{ 1 H} NMR (202.5 MHz, C 6 D 6 , 298 K): δ=22.9 ppm 10a) Diethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethylphosphonate First solution: HP(COMes) 2 (1.03 g, 3.16 mmol) and triethylamine (0.32 mmol) in dme (10 mL) Second solution: neat diethyl vinylphosphonate (0.485 mL, 3.16 mmol) Amount of toluene: 40 mL Yield: 1.38 g, 89% th., yellow oil 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=30.6 ppm (d, J PP =55.35 Hz), 57.05 ppm (d, J PP =55.35 Hz) 10b) Diethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethylphosphonate Acylphosphane: 0.89 g (1.81 mmol) of compound obtained according to Example 10a Amount of toluene: 10 ml Oxidant: aqueous hydrogen peroxide (0.21 mL, 2.2 eq., 2.00 mmol, 30%) Recrystallization: none, but washing with hexane (3×7 mL) Yield: 90% th. 31 P{ 1 H} NMR (80 MHz, toluene, 298 K): δ=24.44 ppm (d, J PP =57.6 Hz), 29.18 ppm (d, J PP =57.6 Hz) 11a) methyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate First solution: HP(COMes) 2 (514 mg, 1.57 mmol) and triethylamine (0.16 mmol) in dme (5 mL) Second solution: neat methylacrylate (0.142 mL, 1.57 mmol) Note: Reaction was carried out at 40° C. for twelve hours Amount of toluene: 6 mL Yield: 0.63 g, 98% th. 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=50.5 ppm 11b) methyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate Acylphosphane: 0.33 g (0.79 mmol) of compound obtained according to Example 11a Amount of toluene: 5 ml Oxidant: tert-butyl hydroperoxide (0.16 mL, 1.1 eq., 0.87 mmol, 5.5M in decane) Recrystallization: from 7 mL toluene layered with hexane (2 mL) Yield: 0.32 g, 95% th., yellow oil after additional, final washing with 3×5 mL hexane and drying 31 P{ 1 H} NMR (202.5 MHz, C 6 D 6 , 298 K): δ=26.5 ppm 12a) 3-(trimethoxysilyl)propyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate First solution: HP(COMes) 2 (3 g, 9.19 mmol) and triethylamine (0.92 mmol) in dme (30 mL) Second solution: neat 3-(acryloyloxy)propyltrimethoxy-silane (2.032 mL, 9.19 mmol) Note: Reaction was carried out at 60° C. for twelve hours Amount of toluene: 6 mL Yield: 4.79 g, 93% th., yellow oil after additional, final washing with 3×7 mL hexane and drying 31 P NMR (121.5 MHz, d8-thf, 298 K): δ=52.1 ppm (t, 2 J PH =11.48 Hz) 12b) 3-(trimethoxysilyl)propyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate Acylphosphane: 2.67 g (4.76 mmol) of compound obtained according to Example 12a Amount of toluene: 20 ml Oxidant: aqueous hydrogen peroxide (0.54 mL, 2.2 eq., 5.24 mmol, 30%) Recrystallization: none, but washing with hexane (3×8 mL) Yield: 87% th. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 , 298 K): δ=25.8 ppm 13a) dimethyl 2-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)succinate First solution: HP(COMes) 2 (3 g, 9.19 mmol) and triethylamine (0.92 mmol) in dme (20 mL) Second solution: dimethyl itaconate (1.454 g, 9.19 mmol) in dme (10 mL) Note: Reaction was carried out at 60° C. for twelve hours Amount of toluene: 40 mL Yield: 4.19 g, 94% th., yellow oil after additional, final washing with 3×7 mL hexane and drying 31 P{ 1 H} NMR (162 MHz, d8-thf, 298 K): δ=49.4 ppm 13b) dimethyl 2-((bis(2,4,6-trimethylbenzoyl)phosphoryl)methyl)succinate Acylphosphane: 3.72 g (0.77 mmol) of compound obtained according to Example 13a Amount of toluene: 25 ml Oxidant: aqueous hydrogen peroxide (0.87 mL, 2.2 eq., 0.85 mmol, 30%) Recrystallization: none, but washing with hexane (3×7 mL) Yield: 97% th. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 , 298 K): δ=25.5 ppm 14a) Vinyl 3-(bis(2,4,6-trimethylbenzoyl)phosphino)propanoate First solution: HP(COMes) 2 (2 g, 6.13 mmol) and triethylamine (0.61 mmol) in dme (20 mL) Second solution: neat vinyl acrylate (0.64 mL, 6.13 mmol) Amount of toluene: 30 mL Yield: 2.55 g, 98% th. 31 P{ 1 H} NMR (121.5 MHz, C 6 D 6 , 298 K): δ=51.9 ppm 14b) Vinyl 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate Acylphosphane: 3.72 g (0.77 mmol) of compound obtained according to Example 13a Amount of toluene: 25 ml Oxidant: oxygen dried over phosphorous pentoxide was slowly passed through the stirred solution Recrystallization: from toluene (3 mL) layered with hexane (1 mL) Yield: 88% th. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 , 298 K): δ=24.8 ppm 15a) N,N-methylene-(bis-(bis(2,4,6-trimethylbenzoyl)phosphino)propanamide) First solution: HP(COMes) 2 (2.87 g, 8.78 mmol) and triethylamine (0.88 mmol) in dme (30 mL) Second solution: neat N,N-methylene-bis-acrylamide (0.690 g, 0.5 eq., 4.39 mmol) Note: Reaction was carried out at 50° C. for twelve hours Amount of toluene: 60 mL Yield: 3.484 g, 99% th., yellow solid after additional, final washing with 3×8 mL hexane and drying 31 P{ 1 H} NMR (121.5 MHz, d8-thf, 298 K): δ=50.5 ppm, 50.7 ppm 15b) N,N-methylene-bis-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanamide) Acylphosphane: 2.98 g (3.70 mmol) of compound obtained according to Example 15a Amount of toluene: 15 ml Oxidant: aqueous hydrogen peroxide (0.84 mL, 2.2 eq., 8.14 mmol, 30%) Recrystallization: none, but washing with hexane (3×10 mL) Yield: 2.55 g, 82% th. 31 P{ 1 H} NMR (202.5 MHz, CDCl 3 , 298 K): δ=26.8 ppm 16a) 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-pyridine First solution: HP(COMes) 2 (3.15 g, 9.64 mmol) in dme (30 mL) Note: Triethylamine was not added since vinylpyridine itself serves as a base Second solution: neat 2-vinylpyridine (1.04 mL, 9.64 mmol) Note: Reaction was carried out at 50° C. for twelve hours Amount of toluene: 60 mL Yield: 3.83 g, 92% th., yellow solid after additional, final washing with 3×5 mL hexane and drying 31 P{ 1 H} NMR (202.5 MHz, dme, 298 K): δ=52.44 ppm 16b) 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-pyridine A 50 mL Schlenk flask was charged with HP(COMes) 2 (0.76 g, 2.33 mmol), which was suspended in H 2 O (10 mL) under an argon atmosphere. Subsequently, neat 2-vinylpyridine (0.25 mL, 1 eq., 2.33 mmol) was added to the solution. The reaction mixture was allowed to stir at room temperature for 12 h. The formation of the addition product 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphino)ethyl)-pyridine was confirmed by 31 P-NMR spectroscopy (δ=50.1 ppm). The solution was adjusted to a pH-value of 7 by adding NH 4 Cl (76 mg, 0.61 eq., 1.42 mmol). Furthermore, aqueous H 2 O 2 was added to the solution. After a reaction time of 12 h at room temperature, the reaction mixture was treated extracted with dichloromethane (2×5 mL). The organic phases were combined, dried over NaSO 4 and the solvent was removed in vacuo to yield a yellow solid (0.87 g, 1.98 mmol, 85%). 31 P{ 1 H} NMR (101.3 MHz, D 2 O, 298 K): δ=24.4 ppm. 16c) 2-(2-(bis(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-pyridine Acylphosphane: 339 mg (0.79 mmol) of compound obtained according to Example 16a Amount of toluene: none, solvent employed instead: dme (5 ml) Oxidant: tert-butyl hydroperoxide (0.16 mL, 1.1 eq., 0.86 mmol, 5.5M in decane) Recrystallization: none, but washed with hexane (3×5 mL) Yield: 0.34 g, 97% th. 31 P{ 1 H} NMR (101.3 MHz, C 6 D 6 , 298 K): δ=27.1 ppm 17) 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)-N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)propanamide First solution: HP(COMes) 2 (500 mg, 1.53 mmol) and triethylamine (0.15 mmol) in dme (5 mL) Second solution: neat 2-acrylamido-2-hydroxymethyl-1,3-propanediol (268 mg, 1.53 mmol) Note: Reaction was carried out at 50° C. for twentyfour hours Amount of toluene: 15 mL Yield: not determined, toluene solution was directly employed for oxidation Oxidant: aqueous hydrogen peroxide (0.17 mL, 1.1 eq., 1.68 mmol, 30%) Recrystallization: none, but washed with hexane (3×3 mL) Yield: 0.68 g, 86% th. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 , 298 K): δ=26.1 and 25.9 ppm 18) (bis(2,4,6-trimethylbenzoyl)phosphoryl)-N-cyclohexylformamide First solution: HP(COMes) 2 (1.098 g, 3.36 mmol) and triethylamine (0.17 mmol) in dme (8 mL) Second solution: neat degassed cyclohexyl isocyanate (0.43 mL, 3.36 mmol) Note: Reaction was carried out at room temperature for two hours Amount of toluene: 10 mL Yield: not determined, toluene solution was directly employed for oxidation Oxidant: tert-butyl hydroperoxide (0.35 mL, 1.1 eq., 3.6 mmol, 5.5M in decane) Recrystallization: none Yield: 1.43 g, 91% th. 31 P{ 1 H} NMR (202.5 MHz, d8-thf, 298 K): δ=0.1 ppm 19a) N-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-N,N-dimethylamine First solution: NaP(COMes) 2 (434 mg, 1.12 mmol) in thf (5 mL) Second solution: N,N-dimethylmethyleneiminium chloride (105 mg, 1.12 mmol) in thf (1 mL, suspension) Amount of toluene: 20 mL, Sodium chloride was separated by filtration Yield: 372 mg, 87% th., yellow solid after additional, final washing with 3×1 mL hexane and drying 31 P{ 1 H} NMR (162 MHz, thf, 298 K): δ=39.6 ppm 19b) N-((bis(2,4,6-trimethylbenzoyl)phosphino)methyl)-N,N,N-trimethylammonium triflate A 20 mL Schlenk flask was charged with the phosphine obtained according to Example 19a) (151 mg, 0.39 mmol), which was dissolved in thf (4 mL). Subsequently, methyl triflate (45.3 μL, 0.39 mmol) in thf (5 mL) was added dropwise to the stirred solution. After a reaction time of 2 h at rt, the solvent was removed under reduced pressure. The solid residue was dissolved in an ethanol (5 mL) acetonitrile (2 mL) mixture. Subsequently, oxygen was slowly passed through the stirred solution at room temperature for 1 h. The solvent was removed in vacuo and the pale yellow solid obtained was recrystallised from dichloromethane. The product was dried under high vacuum for twelve hours to yield 196 mg (0.35 mmol, 89% th.). 31 P{ 1 H} NMR (101.3 MHz, CDCl 3 , 298 K): δ=10.3 ppm 20) methyl 3-(phenyl(2,4,6-trimethylbenzoyl)phosphoryl)propanoate A solution of NaPPh(COMes) (30 mg, 0.11 mmol) prepared according to Example 3 in dme (0.5 mL) was prepared in an NMR-tube. Subsequently, a diethyl ether solution of hydrochloric acid (65 μL, 0.13 mmol, 1.2 eq., 2M) was added. After mixing, the solution was concentrated under reduced pressure. The white solid residue of HPPh(COMes) was dissolved in dme (0.5 mL). A 31 P-NMR spectrum was recorded to observe the chemical shifts for the enol and keto form of HPPh(COMes) δ=49.90 ppm (s) and δ=−20.11 ppm (d, J PH =235 Hz) respectively. Methyl acrylate (19.5 μL, 0.22 mmol, 2 eq.) and triethylamine (5 μL, 0.04 mmol, 33 mol-%) were added to the solution, which was then warmed to 60° C. for twelve hours. Product formation was confirmed by 31 P-NMR spectroscopy δ=11.12 ppm (101.3 MHz, dme, 298 K). Finally, aqueous hydrogen peroxide (17 μL, 0.16 mmol, 1.5 eq., 30%) was added to the solution and mixed for one hour. The desired product was obtained, which could be confirmed by 31 P-NMR spectroscopy. 31 P{ 1 H} NMR (202.5 MHz, dme, 298 K): δ=27.9 ppm 21) 2-(2-(phenyl-(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-pyridine A solution of NaPPh(COMes) (30 mg, 0.11 mmol) prepared according to Example 3 in dme (0.5 mL) was prepared in an NMR-tube. Subsequently, a diethyl ether solution of hydrochloric acid (65 μL, 0.13 mmol, 1.2 eq., 2M) was added. After mixing, the solution was concentrated under reduced pressure. The white solid residue of HPPh(COMes) was dissolved in dme (0.5 mL). A 31 P-NMR spectrum was recorded to observe the chemical shifts for the enol and keto form of HPPh(COMes) δ=49.90 ppm (s) and δ=−20.11 ppm (d, J PH =235 Hz) respectively. 2-Vinylpyridine (23 μL, 0.22 mmol, 2 eq.) and was added to the solution, which was then warmed to 60° C. for twelve hours. Product formation was confirmed by 31 P-NMR spectroscopy δ=14.65 ppm (202.5 MHz, dme, 298 K). Finally, aqueous hydrogen peroxide (17 μL, 0.16 mmol, 1.5 eq., 30%) was added to the solution and mixed for one hour. The desired product was obtained, which could be confirmed by 31 P-NMR spectroscopy. 31 P{ 1 H} NMR (202.5 MHz, dme, 298 K): δ=29.4 ppm. 22) di-(2-(phenyl-(2,4,6-trimethylbenzoyl)phosphoryl)ethyl)-sulfone A solution of NaPPh(COMes) (30 mg, 0.11 mmol) prepared according to Example 3) in dme (0.5 mL) was prepared in an NMR-tube. Subsequently, a diethyl ether solution of hydrochloric acid (65 μL, 0.13 mmol, 1.2 eq., 2M) was added. After mixing, the solution was concentrated under reduced pressure. The white solid residue of HPPh(COMes) was dissolved in dme (0.5 mL). A 31 P-NMR spectrum was recorded to observe the chemical shifts for the enol and keto form of HPPh(COMes) δ=49.90 ppm (s) and δ=−20.11 ppm (d, J PH =235 Hz) respectively. Divinyl sulfone (5.4 μL, 0.06 mmol, 0.5 eq.) and was added to the solution, which was then warmed to 60° C. for twelve hours. Product formation was confirmed by 31 P-NMR spectroscopy δ=11.66 ppm (202.5 MHz, dme, 298 K). Finally, aqueous hydrogen peroxide (17 μL, 0.16 mmol, 1.5 eq., 30%) was added to the solution and mixed for one hour. The desired product was obtained, which could be confirmed by 31 P-NMR spectroscopy. 31 P NMR (202.5 MHz, dme, 298 K): δ=26.4 ppm. 23) 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoic acid 2-(2-ethoxyethoxy)ethylester Bis(mesitoyl)phosphane (HP(COMes) 2 , 3.916 g, 12 mmol) was dissolved in dme (40 ml) under argon and 2-(2-ethoxyethoxy) ethyl acrylate (2.259 g, 12 mmol, 1 eq.) and NEt 3 (0.17 ml, 1.2 mmol, 10%) was added. The reaction mixture was stirred at room temperature for 12 h before HCl was added (2M in diethyl ether, 0.6 mL, 1.2 mmol, 0.1 eq.) dropwise at 0° C. The mixture was stirred for 30 min. and then dme was removed under reduced pressure. The residue was dissolved in toluene (20 mL) and the precipitated triethylamine hydrochloride was removed by filtration. Subsequently, aqueous hydrogen peroxide (30%, 0.8 mL, 2.2 eq.) was added under exclusion of light over a period of 15 minutes at 0° C. Subsequently, the reaction mixture was stirred for 6 h. The resulting yellow solution was concentrated and dissolved in 20 mL THF and dried over Na 2 SO 4 . After filtration, the solvent was removed under vacuum for 12 h to yield 5.437 g (10.25 mmol, 85.4%) of a yellow oil. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 ) δ[ppm]=25.09. 24) Bis-(3-[2-(2-ethoxyethoxy)ethoxycarbonyl]-propyl-(2,4,6-trimethylbenzoyl)-phosphine oxide Red phosphorous (P 4 , 0.248 g, 2 mmol) and naphthalene (0.104 g, 0.8 mmol, 0.1 eq.) were suspended in 10 ml dme. Freshly cut sodium pieces (Na, 0.552 g, 24 mmol, 3 eq.) were subsequently added to the suspension. The mixture was stirred for 12 hours, t BuOH (1.61 ml, 16 mmol, 2 eq.) in 5 ml dme was then added dropwise to the mixture at 0° C. The resulting black suspension was stirred for an additional 2 hours. Subsequently, mesityl(ethylcarboxylate) (1.78 mL, 8.8 mmol, 1.1 eq.) was added and reacted at 60° C. for 16 h to give Na[HP—CO(Mes)]. To this yellow suspension, HCl (2M in diethyl ether, 12 mL, 24 mmol, 3 eq.) was added dropwise at 0° C. and the reaction mixture was stirred for 30 min. Subsequently, the solvent and all volatiles were removed under reduced pressure. The residue was again dissolved in dme (10 ml) and 2-(2-ethoxyethoxy) ethyl acrylate (3.0 ml, 16 mmol, 2 eq.) and 1,5-diazabicyclo-[4,3,0]-non-5-ene (DBN, 0.1 ml, 0.8 mmol, 10%) were added at 0° C. The mixture was warmed to room temperature and stirred for 1 h. Then HCl (2M in Diethyl ether, 0.4 mL, 0.8 mmol, 0.1 eq.) was added dropwise at 0° C. and the mixture stirred for 30 min before dme and all volatiles were removed under reduced pressure. The residue was dissolved in toluene (25 mL) and the precipitated salts were removed by filtration. Subsequently, aqueous hydrogen peroxide (30%, 1.9 mL, 2.3 eq.) was added under exclusion of light over a period of 15 minutes at 0° C. and the mixture stirred for 1 h. The resulting yellowish solution was concentrated and dissolved in 50 mL dichloromethane and dried over Mg 2 SO 4 . After filtration the solvent was removed and the residue dried for 12 h under vacuum to yield 3.679 g (6.43 mmol, 80.3%) of a slightly yellow oil. 31 P{ 1 H} NMR (121.5 MHz, CDCl 3 ) δ[ppm]=38.5. 25a) trimethylolpropane tris-[3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoate] A solution of HP(COMes) 2 (3.031 g, 9.29 mmol, 3 eq.) and NEt 3 (94 μL, 0.93 mmol, 0.3 eq.) in dme (30 ml) was prepared in a 100 ml Schlenk flask. After the addition of trimethylolpropane triacrylate (0.834 mL, 3.10 mmol, 1 eq.), the solution was stirred at room temperature for 12 h. A solution of HCl in diethyl ether (0.5 ml, 0.93 mmol, 0.3 eq.) and the reaction mixture stirred for 1 h at room temperature. The solvent was removed under vacuum, toluene (15 ml) was added and the precipitate of triethylammonium chloride was separated by filtration. After the addition of aqueous hydrogen peroxide (3.2 mL, 30.66 mmol, 3.3 eq., 30 wt.-%) at 0° C., the reaction mixture was stirred at room temperature for 12 h. The solvent was removed in vacuo, the residual solid was dissolved in diethyl ether (50 mL) and dried over NaSO 4 . After filtration, the solvent was removed under reduced pressure to obtain a yellow solid (3.531 g, 2.70 mmol, 87%, M=1309.39 g/mol). 31 P{ 1 H} NMR (121.49 MHz, C 6 D 6 , 298 K): δ=26.62 ppm; UV/VIS λ [nm]=240 (sh.), 291, 362, 394; IR ν [cm −1 ]=; ESI MS [M+NH 4 ] + m/z=1340.5753, meas. 1340.5735; m.p. 79° C. 25b) A mixture of trimethylolpropane tris-[3-(bis(2,4,6-trimethylbenzoyl)-phosphoryl)-propanoate], trimethylolpropane monoacrylate-bis-[3-(bis(2,4,6-trimethylbenzoyl)-phosphoryl)-propanoate] and trimethylolpropane bisacrylate-mono-[3-(bis(2,4,6-trimethylbenzoyl)-phosphoryl)-propanoate] A solution of HP(COMes) 2 (150 mg, 0.460 mmol, 1.5 eq.) and NEt 3 (7 μL, 0.05 mmol, 0.15 eq.) in 1,2-dimethoxyethane (dme, 1.5 ml) was prepared in a 100 ml Schlenk flask. After the addition of trimethylolpropane triacrylate (82 μL, 0.306 mmol, 1 eq.), the solution was stirred at room temperature for 12 h. A solution of HCl in diethyl ether (25 μl, 0.05 mmol, 0.15 eq.) and the reaction mixture stirred for 1 h at room temperature. The solvent was removed under vacuum, toluene (1.5 ml) was added and the precipitate of triethylammonium chloride was separated by filtration. The solvent was removed in vacuo, the residual solid was dissolved in dme (3 mL) and dry air was passed through the solution for 20 min before stirring the solution for 3 h at room temperature. After removal of the solvent under reduced pressure the yellow solid residue was dried under high vacuum for 2 h to obtain the desired product mixture (243 mg, 93%). 31 P NMR (101.3 MHz, thf, 298 K): δ=25.22, 25.26, 25.38 ppm. 26) Dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)fumarate and dimethyl 2-(bis(2,4,6-trimethylbenzoyl)phosphino)maleate In an NMR tube HP(COMes) 2 (21 mg, 0.064 mmol, 1 eq.) was dissolved in dme (0.5 mL). Triethylamine (1 μL, 11 mol-%) and dimethyl acetylene dicarboxylate (7.9 μL, 0.064 mmol, 1 eq.) were added to the solution. After mixing for 30 min a 31 P NMR spectrum was recorded. 31 P NMR (121.49 MHz, dme, 298 K) δ[ppm]=56.93 (d, 3 J PH(cis) =21.87 Hz) and 59.72 (d, 3 J PH(trans) =14.58 Hz) 27) 3-(bis(2,4,6-trimethylbenzoyl)phosphoryl)propanoyl-oxyethyltrimethylammonium chloride In a 100 mL Schlenk flask HP(COMes) 2 (1.19 g, 3.65 mmol, 1 eq.) was suspended in degassed, destilled water (10 mL). NEt 3 (50 μL, 0.365 mmol, 0.1 eq.) followed by 2-acryloxyethyltrimethylammonium chloride (1 mL, 3.65 mmol, 1 eq., 80 wt.-% in water) was added to the suspension. The flask was first kept in a ultra-sound bath at 40° C. for 2 h. Subsequently, the reaction mixture was allowed to stir at room temperature for 12 h. Aqueous concentrated hydrochloric acid (33 μL, 0.1 eq., 37 wt.-%) was added to adjust the pH to around 5 to 6. After the addition of aq. hydrogen peroxide (0.38 mL, 3.65 mmol, 1 eq., 30 wt.-%) at 0° C., the reaction mixture was stirred at room temperature for 12 h. The obtained yellow precipitate was collected by filtration and dried under high vacuum for 4 h (first fraction, 0.359 g, 18%). The remaining solution was concentrated in vacuo and the residual solid was recrystallised from ethanol. A yellow solid was obtained (second fraction, 1.17 g, 60%, M=536.04 g/mol). Total yield: 78%. 31 P{ 1 H} NMR (101.3 MHz, H 2 O, 298K): 25.33 ppm. Examples 28 to 31: Emulsion Polymerisations and Bulk Polymerisations Bulk Polymerisations (BP) A solution of the photoinitiator (PI) (0.1 mol-%) in the monomer (styrene (S), vinyl acetate (VA)) was prepared in a degas sed quartz tube sealed with a septum. The sample was irradiated with UV light under vigorous stirring for 1.5 h at room temperature. The obtained polymers were washed with methanol and dried under high vacuum for 1 h. Emulsion Polymerisations (EP) In a quartz tube sealed with septum 12 mL degassed SDS solution (1.7 weight-%) and the (PI 0.14 mol-%) were mixed. Subsequently, the monomer was added and the suspension was stirred vigorously for 15 min. The sample was irradiated with UV light for 1.5 h, before precipitating the polymer with methanol. UV irradiation was carried out for all examples 28 to 31 with a mercury vapour pressure lamp (Heraeus TQ 150, 150 W) inside a quartz dip tube, which was immersed into a temperature controlled solvent bath. Results: PI according M (PI) V (monomer) Yield Example to Example [mg] Monomer [mL] [%] 28 (EP) 7a 10.8 S 2 74.7 29 (EP) 4c 11.4 S 2 84.7 30 (BP) 5b 14.5 VA 3 63.6 31 (BP) 8b 26.9 VA 3 77.6 The polymer of Example 29 was not soluble in chloroform of DMF and could therefore not be characterised by size exclusion chromatography (SEC). Examples 32 to 34: Emulsion Polymerisations The given amount of photoinitiator was mixed with degas sed, distilled water (10 mL for the surfactant free emulsion polymerization, SFEP) or SDS-solution (2 mL, 10 wt-%) and styrene (1 ml) in a 15 mL glass vial. The obtained suspension was stirred vigorously for 15 min prior to irradiation. The mixture was subsequently irradiated with blue LED light for 1.5 h whilst stirring, to yield a polystyrene dispersion in water. Irradiation experiments with blue LED light were performed in the cavity of an aluminium cylinder (d=12 cm, h=25 cm) fitted with a 5 m self-adhesive LED strip (λ max =465 nm, 60 LEDs per meter) connected to a power-supply unit. Results: PI according to M (PI) Example Example [mg] Result: 32 (SDS) 18 11.2 White polystyrene latex (1.23 wt.-%) 33 (SDS) 19b 11.5 White polystyrene latex (1.49 wt.-% 34 (SFEP) 23 149   White polystyrene latex, (16.4 wt.-%) DLS: Z av = 127 nm, PDI = 0.19 DLS = Dynamic Light Scattering, PDI = Polydispersity Index Examples 35 to 39: Bulk Polymerisations The photoinitiator (PI) was dissolved in the monomer (n-butylacrylate, BA or 1,6-hexandioldiacrylate, HDDA) and the solution was transferred to a round glass dish such that the bottom of the dish was covered by the liquid. The mixture was subsequently irradiated from above at room temperature with a mercury vapour pressure lamp (Heraeus TQ 150, 150 W) inside a quartz dip tube, which was immersed into a temperature controlled solvent bath for 1.5 h (Example 39: 2 h). Results: PI according to Monomer V (M) Example Example M (PI) [mg] M [mL] Polymer Characterisation 35 25a 42 BA 1.5 gel like colourless polymer, (2.5 wt-%) swellable in thf 36 14b   19.7 BA 1.5 gel like colourless polymer, (1.76 wt-%)  insoluble in thf 37 15b 42 BA 1.5 gel like colourless polymer, (2.5 wt-%) swellable in thf 38 25b 42 BA 1.5 rubber like, colourless (2.5 wt-%) polymer, insoluble in thf 39 25a 30 HDDA 5 Solid,brittle, colourless (0.59 wt-%)  polymer, insoluble in thf Examples 40 and 41: Solution Polymerisations A solution of the monomer (1.5 mL) and the photoinitiator (PI) in the solvent was prepared in a 15 mL glass vial sealed with a septum, under an argon atmosphere. The solution was irradiated with blue LED light as described for examples 32 to 34 for 2 hours (ex. 40) or 1.5 hours (ex. 41) whilst stirring. Results: PI according Polymer Ex- to M (PI) Monomer V(M) Character- ample Example [mg] M [mL] Solvent isation 40 23 42 BA 1.5 dme gel like (2.5 wt-%) (2 ml) colourless polymer 41 27 42 AETMACL 2.3 water water (2.5 wt-%) (5 ml) soluble polymer AETMACL: 2-acryloxy-ethyltri-methyl-ammonium chloride (80% in H 2 O) The present invention is not limited to embodiments described herein; reference should be had to the appended claims.

The present invention provides a process for the preparation of mono- and bisacylphosphanes based on formula (I): as well as for their corresponding oxides or sulfides. The present invention further relates to photoinitiators obtainable by said process.

BACKGROUND OF THE INVENTION The present invention relates to a booster circuit used for a flash memory or the like. Generally, to write/erase data in/from a flash memory, channel hot electrons or a tunnel current is used. For this purpose, a high voltage is required because a high electric field must be applied to the gate. Conventionally, a terminal for supplying a high external voltage is arranged independently of the power supply terminal. In recent years, however, a single power supply is used to simplify the external power supply circuit. The power supply voltage to be supplied is conventionally often 5 V, though it is lowering to 2 or 3 V to reduce the power consumption or increase the operation speed. The memory chip incorporates a booster circuit for generating a voltage higher than the externally supplied power supply voltage, and recently, the boosting ratio need be higher than the conventional one. FIG. 16 shows a booster circuit disclosed in Japanese Patent Laid-Open No. 9-8229 (to be referred to as prior art 1 hereinafter). This booster circuit comprises diodes D1 to D5, capacitors CP1 to CP4, a capacitive load CL, and driving circuits DV1 and DV2. Referring to FIG. 16, a circuit constituted by, e.g., the diode D2 and the capacitor CP2 is called a pump circuit PC. The booster circuit shown in FIG. 16 has four pump circuits PC. Nodes between the diodes D1 to D4 and the one-terminal sides of the capacitors CP1 to CP4 are represented by N1 to N4, respectively; a node between the diode D5 and the load capacitor CL, NL; and nodes between the capacitors CP1 and CP2 and the output terminals of the driving circuits DV1 and DV2, N181 and N182, respectively. Connection in the booster circuit shown in FIG. 16 will be described next. The anode side of the diode D1 is connected to the power supply, and the cathode side is connected to the capacitor CP1 through the node N1 to form the first pump circuit. The anode side of the diode D2 is connected to the node N1, and the cathode side is connected to the capacitor CP2 through the node N2 to constitute the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third and fourth pump circuits respectively constituted by the diodes D3 and D4 and the capacitors CP3 and CP4 are connected in series. The other terminal of each of the odd-numbered capacitors CP1 and CP3 counted from the first pump circuit is connected to the driving node N181. The other terminal of each of the even-numbered capacitors CP2 and CP4 counted from the first pump circuit is connected to the driving node N182. A two-phase clock signal φ181 and a clock φ182 as the inverted signal of the clock φ181, which have timings as shown in FIGS. 17A and 17B, are supplied to the outputs, i.e., the driving nodes N181 and N182 of the driving circuits DV1 and DV2, respectively. The driving nodes N181 and N182 for the capacitors CP1 and CP3 and the capacitors CP2 and CP4 are alternately driven in opposite phases, thereby outputting a high voltage from an output terminal Voz. In the arrangement shown in FIG. 16, a voltage five times higher than a power supply voltage Vcc is obtained. Note that the capacitor CP is called a pump capacitance. The operation of this circuit will be described next in more detail with reference to FIGS. 16, 17A, and 17B. For the descriptive convenience, assume that the circuit is constituted by two pump circuits, the load capacitor CL is connected to the node N3, the power supply voltage Vcc is 4 V, the capacitors CP1 and CP2 have the same capacitance value as that of the load capacitor CL, the threshold value of the diodes D1 to D3 is 0 V, and low and high levels of the clocks φ181 and φ182 are 0 V and 4 V, respectively. In the initial state at time T180, the driving nodes N181 and N182 are at 0 V, and the nodes N1, N2, and NL are at 4 V because the power supply voltage Vcc is supplied through the diodes D1 to D3. As a result, the output voltage Voz is also 4 V. At time T181, the clock φ181 rises to set the driving node N181 at 4 V. The voltage at the node N1 temporarily changes from 4 V to 8 V and immediately stabilizes at 5.3 V because charges flow to the nodes N2 and NL through the diodes D2 and D3. This is because charges accumulated in the capacitor CP1 are distributed to the capacitor CP2 and the load capacitor CL. The clock φ182 does not change, and the driving node N182 also maintains 0 V. At time T182, the clock φ181 falls to set the driving node N181 at 0 V. Charges stored on the N181 side of the capacitor CP1, which correspond to 4 V, are removed through the driving circuit DV1. Simultaneously, the voltage on the node N1 side of the capacitor CP1 lowers from 5.3 V to 1.3 V and then rises to 4 V because of supply of the power supply voltage Vcc through the diode D1. Letting C (F) be the electrostatic capacitance of the capacitor CP1, the loss charge amount due to this discharge is given by C×Vcc (coulomb). On the other hand, the clock φ182 rises to set the driving node N182 at 4 V. The voltage on the node N2 side of the capacitor CP2 temporarily becomes 9.3 V because 4 V is added to 5.3 V. However, since the diode D3 is turned on to transfer charges to the load capacitor CL, the node N2 side stabilizes at 7.3 V, and the output voltage Voz also becomes 7.3 V. At time T183, the clock φ181 rises again to repeat the same operation as at time T181. On the other hand, when the clock φ182 falls, the driving node N182 is set at 0 V, and charges stored on the driving node N182 side of the capacitor CP2 are removed through the driving circuit DV2. Letting C (F) be the electrostatic capacitance of the capacitor CP2, the loss charge amount due to this discharge is given by C×Vcc (coulomb). This boost operation is repeated, and the output terminal Voz finally converges to 12 V. Since discharge is performed twice in one period, the loss charge amount for one period is C×Vcc×2 (coulomb). Since Vcc is 4 V, the loss charge amount is 8C (coulomb). In prior art 1, letting Z be the number of pump circuits, the boost voltage is generally given by (Z+1)×Vcc, and the loss charge amount is given by Z×C×Vcc (coulomb). Therefore, the loss charge amount per unit boost ratio is represented by {Z/(Z+1)}×C×Vcc (coulomb). FIG. 18 shows another conventional booster circuit (to be referred to as second prior art hereinafter) disclosed in "1996 Symposium on VLSI Circuits Digest of Technical Papers", pp. 110-111. FIG. 18 shows the circuit in mode 2. This booster circuit is of a full-wave rectification type and aims at increasing the current amount to be output from the booster circuit and reducing the power consumption by recycling some removed charges. The booster circuit of prior art 2 comprises PMOS transistors M1 and M4, NMOS transistors M2, M3, M5, M6, M7, and M8, drivers DV201 and DV202 for inverting an input signal and outputting the inverted signal, diodes D201 and D202, and capacitors C201 to C204. Nodes between the transistors M1 and M2, between the transistors M2 and M3, between the transistors M5 and M7, and between the transistors M6 and M8 are represented by N201, N202, N203 and N205, respectively. The connection relationship in the circuit of prior art 2 shown in FIG. 18 will be described. A clock φ201 is connected to the gate of the transistor M2 and to the gate of the transistor M4 through the driver DV202. A clock φ202 is connected to the gate of the transistor M3 and to the gate of the transistor M1 through the driver DV201. The source of the transistor M1 is connected to a power supply Vcc while the drain is connected to the drains of the transistors M2 and M4 and the capacitor C201 at the node N201. The source of the transistor M3 is connected to ground GND while the drain is connected to the sources of the transistors M2 and M4 and the capacitor C202 at the node N202. Each of the nodes N203 and N204, i.e., the other terminal of each of the capacitors C201 and C202, is connected to the source of the corresponding one of the transistors M5 and M6 and the drain of the corresponding one of the transistors M7 and M8. The drains of the transistors M5 and M6 and the anodes of the diodes D201 and D202 are connected to the power supply Vcc. The cathode of the diode D201 is connected to the gates of the transistors M5 and M8 and the capacitor C203. The cathode of the diode D202 is connected to the gates of the transistors M6 and M7 and the capacitor C204. The other terminal of each of the capacitors C203 and C204 is connected to the corresponding one of clocks φ203 and φ204. The sources of the transistors M7 and M8 are connected to a load capacitor CL at a node NL. The operation of prior art 2 will be described next with reference to the timing charts of FIGS. 19A to 19H. For the descriptive convenience, in FIGS. 19A to 19H, assume that the power supply voltage Vcc is 4 V, and the capacitors C201 and C202 have the same capacitance value C (F) as that of the load capacitor CL. In addition, the threshold value of the transistors M1 to M8 is 0 V, and low and high levels of the clocks φ201 to φ204 are 0 V and 4 V, respectively. The clocks φ201 to φ204 have the same frequency. The clock signals φ201 and φ202 have a phase difference corresponding to 1/2 the period, and so do the clock signals φ203 and φ204. The clock signals φ203 and φ204 go high when a predetermined time has elapsed after the clock signals φ201 and φ202 change to high level, respectively, and then simultaneously go low. At transient time T200, assume that the node N201 is at 4 V (Vcc), the node N202 is at 0 V (GND), the node N203 is at about 5 V (Vpp), and the node N204 at 4 V (Vcc). At time T201, since the clock signal φ201 goes high while the clock signal φ202 is at low level, the outputs from the driver DV201 and DV202 are at high and low levels, respectively. At this time, the transistors M1 and M3 are turned off, and the transistors M2 and M4 are turned on. Consequently, charges corresponding to 4 V which are stored on the node N201 side of the capacitor C201 move, through the transistors M2 and M4, to the node N202 side of the capacitor C202 which is being discharged to 0 V, so both the nodes N201 and N202 are set at 2 V (1/2×Vcc). On the other hand, charges corresponding to 5 V (Vpp) which are stored on the node N203 side of the capacitor C201 decrease by 2 V to 3 V (Vpp-1/2×Vcc). Charges corresponding to 2 V are added to the node N204 side of the capacitor C202 which is being charged to 4 V, so the node N204 is set at 6 V (3/2×Vcc). At time T202, the clock signal φ203 goes high while the clock signal φ201 is at high level and the clock signal φ202 is at low level. The transistors M5 and M8 are turned on. As a result, the charges corresponding to 6 V (3/2×Vcc), which are stored on the node N204 side of the capacitor C202, are distributed to the load capacitor CL through the transistor M8, and the voltage converges to 5.5 V (Vpp). The node N203 side of the capacitor C201, which is being discharged to 3 V (Vpp-1/2×Vcc), is charged to 4 V, i.e., the power supply voltage Vcc through the transistor M5. After this, the clocks φ201 and φ203 go low, and the transistors M2, M4, M5, and M8 are turned off. The voltage at each node is kept unchanged. At time T203, the clock signal φ202 goes high, and the outputs from the drivers DV201 and DV202 are set at low and high levels, respectively. At this time, the transistors M1 and M3 are turned on, and the transistors M2 and M4 are turned off. The node N201 side of the capacitor C201 is charged to the power supply voltage Vcc of 4 V through the transistor M1. The node N202 side of the capacitor C202, which is being charged to 2 V, is set at GND, i.e., 0 V through the transistor M3. On the node N203 side of the capacitor C201, which is being charged to 4 V, charges corresponding to 2 V are added to set the node N203 at 6 V (3/2×Vcc). On the node N204 side of the capacitor C202, which is being discharged to 5.5 V (Vpp), charges corresponding to 2 V are removed to set the node N204 at 3.5 V (Vpp-1/2×Vcc). At time T204, the clock φ204 goes high while the clocks φ201 and φ202 are set at low and high levels, respectively, so the transistors M6 and M7 are turned on. As a result, charges corresponding to 6 V (3/2×Vcc), which are stored on the node N203 side of the capacitor C201, move to the load capacitor CL through the transistor M7 and the node NL, so the voltage converges to 5.75 V (Vpp). The node N204 side of the capacitor C202, which is being discharged to 3.5 V, is charged to the power supply voltage of 4 V through the transistor M6. After this, the clocks φ202 and φ204 go low, and the transistors M1, M3, M6, and M7 are turned off. The voltage at each node is held. By repeating this operation, the load capacitor CL is gradually charged to a higher voltage, and the output voltage Vpp finally converges to 6 V. In the booster circuit of prior art 2, charges corresponding to the power supply voltage Vcc, which are stored in the capacitor C201, are distributed to the capacitor C202 through the transistors M2 and M4, and charges corresponding to 1/2×Vcc are stored in the capacitor C202. These charges are removed to the ground GND in response to the next clock. In this case, the loss charge amount for one period is C×Vcc/2 (coulomb). When Vcc is 4 V, the loss charge amount is 2C (coulomb). The loss charge amount per unit boost ratio is given by 1/3×C×Vcc (coulomb). In the above-described booster circuit of prior art 1, the charge/discharge amount of the capacitor CP by switching is large, and charges corresponding to C×Vcc (coulomb) are lost per capacitor CP in one clock period. When four capacitors are arranged as in prior art 1, the loss becomes C×Vcc×4 (coulomb). This loss increases as the boost ratio of the booster circuit becomes high. Therefore, the power consumption of the circuit undesirably increases. In the booster circuit of prior art 2, the pump circuit is connected to allow a bidirectional operation such that the boost operation is performed twice in one clock period, thereby increasing the current capacitance. In addition, since the transistors M2 and M4 are arranged, charges stored in the capacitor C201 are not grounded but used to charge the capacitor C202, and then the capacitor C202 is discharged. With this arrangement, the loss charge amount can be reduced, and consequently, the power consumption of the booster circuit can be decreased. In the booster circuit of prior art 2, however, the voltage at the driving nodes N201 and N202 changes only by Vcc/2. Charges corresponding to only Vcc/2 can contribute to the boost operation, so no high voltage can be obtained. Therefore, the booster circuit of prior art 2 cannot be used for a write/erase in/from a flash memory because the voltage is too low, although it can be used as a write voltage for a memory cell of a DRAM. In addition, the node N201 of the capacitor C201 must be switched between 0 V and 4 V by the transistors M1 and M2. The node N203 must be driven by the transistors M5 and M8 with a gate voltage of 2×Vcc, i.e., 8 V by using the capacitor C203 and the diode D201 to decrease the ON resistance of the transistors M5 and M8, and be switched at a voltage higher than the power supply voltage. In this circuit arrangement, the number of devices increases, resulting in a complex circuit arrangement. Furthermore, prior art 2 does not disclose an arrangement for realizing a boost ratio of 3 or more. As one arrangement for realizing a boost ratio of 3 or more, a plurality of booster circuits of prior art 2 are prepared, and the output from an output terminal OUT of a preceding stage is supplied to the power supply terminal Vcc of the next stage. However, since the voltage becomes high toward the last stage, the breakdown voltage of a transistor M or diode D to be used must be increased. This increases the size of each device, although the number of devices per stage is large to already result in a large chip size. SUMMARY OF THE INVENTION It is the first object of the present invention to provide a booster circuit which reduces the loss charge amount due to discharge and decreases the power consumption even at a high boost ratio. It is the second object of the present invention to provide a booster circuit capable of realizing a high boost ratio with a simple circuit having a small number of devices while reducing the loss charge amount due to discharge. In order to achieve the above objects, according to the present invention, there is provided a booster circuit comprising a first pump circuit having a first rectifying device, the first rectifying device having one terminal to which a voltage is supplied and the other terminal connected to a first capacitor through a first connection point, a second pump circuit having a second rectifying device, the second rectifying device having one terminal connected to the first connection point and the other terminal connected to a second capacitor through a second connection point, a node driving circuit for outputting a driving signal to a driving node on an opposite side of the connection point of each of the capacitors, switch means connected to the driving nodes of the capacitors, and control means for driving the switch means to control a potential of each of the capacitors, wherein the voltage supplied to the first capacitor is boosted, and the boosted voltage is output through the first and second connection points. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a booster circuit according to the first embodiment of the present invention; FIGS. 2A to 2F are timing charts showing the operation of the booster circuit; FIG. 3 is a circuit diagram showing the first arrangement of a node driving circuit used in the booster circuit; FIGS. 4A to 4G are timing charts showing the operation of the node driving circuit shown in FIG. 3; FIG. 5 is a circuit diagram showing the second arrangement of the node driving circuit; FIGS. 6A to 6I are timing charts showing the operation of the node driving circuit shown in FIG. 5; FIG. 7 is a circuit diagram showing a booster circuit according to the second embodiment; FIG. 8 is a circuit diagram showing a booster circuit according to the third embodiment; FIG. 9 is a circuit diagram showing a booster circuit according to the fourth embodiment; FIG. 10 is a circuit diagram showing a booster circuit according to the fifth embodiment; FIG. 11 is a circuit diagram showing a booster circuit according to the sixth embodiment; FIG. 12 is a circuit diagram showing a booster circuit according to the seventh embodiment; FIGS. 13A to 13D are timing charts showing the operations of various portions of the circuit shown in FIG. 12; FIG. 14 is a circuit diagram showing a booster circuit according to the eighth embodiment; FIG. 15 is a block diagram showing a booster circuit according to the ninth embodiment; FIG. 16 is a circuit diagram showing a conventional booster circuit; FIGS. 17A and 17B are timing charts showing the operations of various portions of the circuit shown in FIG. 16; FIG. 18 is a circuit diagram showing another conventional booster circuit; and FIGS. 19A to 19H are timing charts showing the operations of various portions of the circuit shown in FIG. 18. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIGS. 1 to 4G. FIG. 1 shows a booster circuit according to the first embodiment of the present invention. Referring to FIG. 1, reference numeral 10 denotes a node driving circuit for generating clock signals CK1 and CK2 to drive driving nodes n1 and n2. Reference symbols D1 to D3 denote diodes; CP1 and CP2, capacitors; CL, a load capacitor; and TSW1, a switch opened/closed by a control signal P0. A pump circuit PC is constituted by a diode and a capacitor. The booster circuit shown in FIG. 1 uses two pump circuits. Reference symbol N1 denotes a node corresponding to the connection point between the diode D1 and the capacitor CP1; N2, a node corresponding to the connection point between the diode D2 and the capacitor CP2; and n1 and n2, driving nodes between the capacitor CP1 and the node driving circuit 10 and between the capacitor CP2 and the node driving circuit 10. Connection in the booster circuit shown in FIG. 1 will be described next. The anode of the diode D1 is connected to a power supply Vcc while the cathode is connected to the capacitor CP1 and the diode D2 through the node N1. The cathode of the diode D2 is connected to the capacitor CP2 and the diode D3 through the node N2. The cathode of the diode D3 is connected to the load capacitor CL through a node NL. The outputs CK1 and CK2 from the node driving circuit 10 are connected to the capacitors CP1 and CP2 through the driving nodes n1 and n2, respectively. The opening and closing terminals of the switch TSW1 are connected to the driving nodes n1 and n2, respectively. The control signal P0 for controlling opening/closing is input to the control terminal of the switch TSW1. FIGS. 2A to 2F are timing charts showing the operation timings of various portions of the booster circuit shown in FIG. 1. The operation of this circuit will be described in detail with reference to FIGS. 1 and 2A to 2F. For the descriptive convenience, assume that the power supply voltage Vcc is 4 V, the capacitors CP1 and CP2 have the same capacitance value C (F) as that of the load capacitor CL, the threshold value of the diodes D1 to D3 is 0 V, and the low and high levels of the clocks CK1 and CK2 are 0 V and 4 V, respectively. The clocks CK1 and CK2 have the same frequency and a phase difference corresponding to 1/2 the period. The high- or low-level period is equal to or shorter than 1/4 the period. When the clocks CK1 and CK2 change from high level to low level or from low -Level to high level, the driving nodes n1 and n2 are set in a floating state (FIGS. 2A and 2B). The control signal P0 has a frequency twice that of the clocks CK1 and CK2 and is set at high level when the clocks CK1 and CK2 are in the floating state. The high-level period of the control signal P0 does not overlap the high- or low-level period of the clocks CK1 and CK2 (FIG. 2C). At time T0, the clocks CK1 and CK2 are at 0 V. The nodes N1 and N2 and an output voltage Voa are at 4 V because the diodes D1 to D3 are turned on to supply the power supply voltage to the capacitors CP1, CP2, and CL. Therefore, the output voltage Voa is 4 V. At time T1, when the clock CK1 rises to 4 V, the node N1 which is charged to 4 V in the initial state temporarily changes to 8 V because 4 V of the clock CK1 is added. Immediately after this, charges move to the side of the nodes N2 and NL through the diodes D2 and D3, and charges corresponding to 4 V added to the capacitor CP1 are distributed to the capacitors CP2 and CL, so the node N1 stabilizes at 5.3 V (FIG. 2D). Immediately before time T2, charges corresponding to 4 V are stored on the driving node n1 side of the capacitor CP1, and charges corresponding to 0 V are stored on the driving node n2 side of the capacitor CP2. At time T2, the control signal P0 goes high to close the switch TSW1. Charges corresponding to 4 V, which are stored in the capacitor CP1, move to the driving node n2 side of the capacitor CP2 through the switch TSW1, so both the driving nodes n1 and n2 are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. In response to this, charges corresponding to 2 V are removed from 5.3 V at the node N1, so the node N1 is set at a lower voltage of 3.3 V. However, the node N1 is charged by the power supply Vcc through the diode D1, so the voltage stabilizes at the Vcc level of 4 V (FIG. 2D). The voltage at the node N2 rises from 5.3 V to 7.3 V and then stabilizes at 6.3 V because charges in the capacitor CP2 are distributed to the load capacitor CL through the diode D3 (FIG. 2E). Therefore, the output voltage Voa also becomes 6.3 V (FIG. 2F). Since the node N1 is at 4 V, charge transfer to the capacitor CP1 side is inhibited by the diode D2. At time T3, the clock CK1 is set at 0 V. Charges corresponding to 2 V on the node n1 side of the capacitor CP1 are removed through the CK1 terminal, so the voltage at the node N1 lowers from 4 V to 2 V. Immediately after this, the node N1 is charged by the power supply Vcc through the diode D1, so the voltage stabilizes at the Vcc level of 4 V (FIG. 2D). When the clock CK2 is set at 4 V, the driving node n2 is charged from 2 V to 4 V, and the voltage at the node N2 rises from 6.3 V to 8.3 V. These charges are distributed to the load capacitor CL through the diode D3 and the node NL, and the voltage at the node N2 stabilizes at 7.3 V (FIG. 2E). Therefore, the output voltage Voa also becomes 7.3 V (FIG. 2F). Immediately before time T4, charges corresponding to 0 V are stored at the driving node n1, and charges corresponding to 4 V are stored at the driving node n2. At time T4, the driving nodes n1 and n2 are electrically connected to move charges corresponding to 4 V at the driving node n2 to the driving node n1 side. Therefore, both the driving nodes n1 and n2 are set at 2 V. Charges corresponding to 2 V are added to the node N1 at 4 V, so the voltage at the node N1 increases to 6 V and then stabilizes at 5.7 V because the charges are distributed to the capacitor CP2 through the diode D2 (FIG. 2D). Since the voltage at the driving node n2 changes from 4 V to 2 V, the voltage at the node N2 lowers from 7.3 V to 5.3 V and then stabilizes at 5.7 V because the charges are distributed from the capacitor CP1, as described above (FIG. 2E). Since the node NL is at 7.3 V, charge transfer to the load capacitor CL side is inhibited by the diode D3, so the voltage of 7.3 V is maintained (FIG. 2F). In the periods from time T5 to time T8 and from time T9 to time T12, the same operation as that from time T1 to time T4 is repeated. However, generation of charge movement to each node depends on the potential relationship between the nodes N1, N2, and NL. With such a periodical operation, charges are sequentially accumulated in the load capacitor CL. Finally, the output voltage Voa becomes 12 V. That is, a voltage three times higher than the power supply voltage Vcc can be obtained using the two pump circuits. In addition, the period when the driving nodes n1 and n2 are electrically connected is set while the outputs from the node driving circuit 10, i.e., the clocks CK1 and CK2 are being inverted. With this arrangement, 1/2 the charges removed from the capacitor CP can be recycled as charges to be stored. For this reason, the power consumption of the booster circuit in obtaining a high voltage can be reduced. In the first embodiment, charges corresponding to C×Vcc/2 (coulomb) are lost for each capacitor CP in one period. This embodiment employs the two-stage structure, and the operation is performed twice in one period. For this reason, charges corresponding to Vcc×C (coulomb) can be saved. In this embodiment, letting G be the number of pump circuits, the boost voltage is generally given by (G+1) x Vcc, and the loss charge amount for one period is given by G×C×Vcc/2 (coulomb). Therefore, the loss charge amount per unit boost ratio is given by {G/2(G+1)}×C×Vcc (coulomb). In comparison to prior art 1 in which the loss charge amount for one period is 2×C×Vcc (coulomb), 50% of the charges can be saved in this embodiment. In addition, in this embodiment, the loss charge amount for one period is twice higher than that of prior art 2, although a voltage twice or more higher can be obtained, and the loss charge amount per boost ratio is equal to that of prior art 2. Furthermore, since the output switching transistors M7 and M8, the gate voltage boosting diodes D201 and D202, and the capacitors C203 and C204 can be omitted, the circuit arrangement is simplified, and the number of devices can be decreased. The period of the clocks CK1 and CK2 can be set to be four or more times the time constant necessary until charges in the capacitors CP1 and CP2 are transferred through the diodes D1 to D3 and converge to a desired level. The period when the control signal P0 of the switch TSW1 is at high level can be set to be equal to or longer than the time constant necessary until charges in the capacitors CP1 and CP2 are transferred through the switch TSW1 and converge to a desired level. FIG. 3 shows the first arrangement of the node driving circuit 10. The node driving circuit 10 is constituted by a CMOS driver. In FIG. 3, the node driving circuit 10 has transistors MOS2 to MOS5. The transistors MOS2 and MOS4 are PMOS transistors, and the remaining transistors are NMOS transistors. Encircled transistors in FIG. 3 are PMOS transistors, and the remaining transistors are NMOS transistors. In FIG. 3, Vcc indicates the power supply voltage; and P0 to P4, control signals to be supplied to the gates of the transistors. The clocks CK1 and CK2 correspond to the output signals from the node driving circuit 10. FIGS. 4A to 4G show the timing charts. Referring to FIG. 3, the sources of the PMOS transistors MOS2 and MOS4 are connected to the power supply Vcc while the gates are connected to the signals P1 and P3, and the drains are connected to the driving nodes n1 and n2. The drains of the NMOS transistors MOS3 and MOS5 are connected to the driving nodes n1 and n2 while the gates are connected to the signals P2 and P4, and the sources are connected to the ground GND. The drain and source of the NMOS transistor MOS1 are connected between the driving nodes n1 and n2 as a switch TSW3. The control signal P0 for ON/OFF-controlling the switch TSW3 is connected to the gate of the transistor MOS1. The operation of the node driving circuit 10 will be described in detail with reference to FIGS. 3 and 4A to 4G. As shown in FIGS. 4B to 4E, the control signals P1 to P4 have the same frequency and repeat the input timings to the corresponding transistors at a period from time T1 to time T4. The signals P1 and P4 have opposite phases, and so do the signals P2 and P3. In addition, the signals P1 and P2 have opposite phases and a phase difference corresponds to 1/2 the period, and so do the signals P3 and P4. The period when the signal P1 or P3 is at low level or while the signal P2 or P4 is at high level is set to be equal to or shorter than 1/4 one period. This period is set such that charge/discharge to/from the capacitor CP is properly performed. As shown in FIG. 4A, the control signal P0 goes high twice in a period, and one high-level period is equal to or shorter than 1/4 one period. When conditions for setting the signals P1 and P3 at high level and the signals P2 and P4 at low level are satisfied, the control signal P0 goes high. When the signal P0 is at high level, the signals P1 and P3 cannot go low or the signals P2 and P4 cannot go high. At time T0 in the initial state, both the clocks CK1 and CK2 are at low level. At time T1, since the signals P1 and P2 are at low level, and the signals P3 and P4 are at high level (FIGS. 4A to 4E), the transistors MOS2 and MOS5 are turned on, and the transistors MOS3 and MOS4 are turned off. The clock CK1 goes high, and the clock CK2 goes low (FIGS. 4F and 4G). After time T1, even when the signals P1 and P2 are inverted to high level, and the signals P3 and P4 are inverted to low level, the discharge amounts of the clocks CK1 and CK2 are small. The clock CK1 maintains high level, and the clock CK2 maintains low level. This state will be referred to as a floating output state hereinafter. At time T2, the control signal P0 goes high (FIG. 4A). The transistor MOS1 is turned on to move charges between the driving nodes n1 and n2. Both the driving nodes n1 and n2 are set at an intermediate potential between them (FIGS. 4F and 4G). This intermediate potential will be referred to as a Vcc/2 level hereinafter. However, when the capacitors CP1 and CP2 have different capacitance values, or stored charge amounts are different, the driving nodes n1 and n2 are not always set at Vcc/2 (V). In this state, even when the control signal P0 is set at low level to turn off the transistor MOS1, the level at the driving nodes n1 and n2 is kept unchanged because of the floating output state. At time T3, since the signals P1 and P2 are at high level, and the signals P3 and P4 are at low level (FIGS. 4A to 4E), the transistors MOS3 and MOS4 are turned on, and the transistors MOS2 and MOS5 are turned off. The clock CK1 goes low, and the clock CK2 goes high (FIGS. 4F and 4G). After time T3, even when the signals P1 and P2 are inverted to high level, and the signals P3 and P4 are inverted to low level, the discharge amounts of the clocks CK1 and CK2 are small. The clock CK1 maintains low level, and the clock CK2 maintains high level (floating output state). At time T4, the control signal P0 goes high (FIG. 4A). Charges move between the driving nodes n1 and n2, and the potential at the driving nodes n1 and n2 is set at Vcc/2 level (FIGS. 4F and 4G). In this state, even when the control signal P0 is set at low level to turn off the transistor MOS1, the levels of the clocks CK1 and CK2 are kept; unchanged (floating output state). From time T5, the operation from time T1 to time T4 is repeated. FIG. 5 shows the second arrangement of the node driving circuit 10. In FIG. 5, two circuits called clocked inverters respectively constituted by transistors MOS12 to MOS15 and transistors MOS16 to MOS19 are used, and connection/disconnection between the outputs from these circuits is controlled by a transistor MOS11. The transistor MOS11 corresponds to the transistor MOS1 in FIG. 3. Referring to FIG. 5, the gates and drains of the PMOS transistors MOS13 and MOS17 are commonly connected, and so do the NMOS transistors MOS14 and MOS18 to constitute a CMOS inverter. The outputs from the CMOS inverter are connected to the nodes n1 and n2, respectively. The sources of the PMOS transistors MS012 and MOS16 are connected to the power supply Vcc while the gates are connected to control signals P11 and P13, and the drains are connected to the CMOS inverters, respectively. The drains of the NMOS transistors MOS15 and MOS19 are connected to the CMOS inverters while the gates are connected to control signals P12 and P14, respectively, and the sources are connected to the ground GND. The drain and source of the NMOS transistor MOS11 are connected between the driving nodes n1 and n2 as a switch TSW5. A control signal P10 for ON/OFF-controlling the switch TSW5 is connected to the gate of the transistor MOS11. FIGS. 6A to 6G show the timings of the control signals P10 to P16 supplied to the node driving circuit shown in FIG. 5. The signals P15 and P16 have the same frequency and opposite phases. The high-level period corresponds to 1/2 the period (FIGS. 6F and 6G). One clock of the signals P15 and P16 is set as one period. The signals P11 and P13 have the same frequency and go low twice in one period (FIGS. 6B and 6D). The signals P12 and P14 have the same frequency and an amplitude opposite to that of the signals P11 and P13 and go high twice in one period (FIGS. 6C and 6E). The control signal P10 goes high before and after the signals P15 and P16 are inverted, i.e. goes high twice in one period. The high-level period of the signals P11 and P13 or the low-level period of the signals P12 and P14 includes the high-level period of the control signal P10 and long. In this period, the outputs from the node driving circuit 10 are set in the floating state. The high-level period of the control signal P10 does not overlap the low-level period of the signals P11 and P13 and the high-level period of the signals P12 and P14. The operations of the node driving circuit and the switch TSW5 in FIG. 5 will be described next with reference to the timing charts of FIGS. 6A to 6I. At time T1, since the signals P11, P13, and P15 are at low level, and the signals P12, P14, and P16 are at high level, the transistors MOS12, MOS13, MOS15, MOS16, MOS18, and MOS19 are turned on, and the transistors MOS14 and MOS17 are turned off. For this reason, the clock CK1 goes high, and the clock CK2 goes low. At the end of time T1, when the signals P11 and P13 go high, and the signals P12 and P14 go low, the transistors MOS12, MOS15, MOS16, and MOS19 are turned off. Although the floating output state is set, the levels of the clocks CK1 and CK2 are kept unchanged. At time T2, the signal P10 goes high. When the transistor MOS11 constituting the switch TSW5 is turned on, the nodes n1 and n2 are electrically connected, so the clocks CK1 and CK2 are set at the Vcc/2 level. At the end of time T2, even when the signal P10 goes low, the levels of the clocks CK1 and CK2 are kept unchanged because of the floating output state. At time T3, since the signals P11, P13, and P16 are at low level, and the signals P12, P14, and P15 are at high level, the transistors MOS12, MOS14, MOS15, MOS16, MOS17, and MOS19 are turned on, and the transistors MOS13 and MOS18 are turned off. For this reason, the clock CK1 goes low, and the clock CK2 goes high. At the end of time T3, when the signals P11 and P13 go high, and the signals P12 and P14 go low, the transistors MOS12, MOS15, MOS16, and MOS19 are turned off. Although the floating output state is set, the levels of the clocks CK1 and CK2 are kept unchanged. At time T4, the signal P10 goes high. The transistor MOS11 constituting the switch TSW5 is turned on to electrically connect the nodes n1 and n2, so the clocks CK1 and CK2 are set at the Vcc/2 level. At the end of time T4, even when the signal P10 goes low, the levels of the clocks CK1 and CK2 are kept unchanged because of the floating output state. From time T5, the operation from time T1 to time T4 is repeated. In FIGS. 5 and 6A to 6I, as the first modification, the control signals P11 and P12 may be used as the control signals P13 and P14, respectively. In addition, the inverted signal of the control signal P15 may be used as the control signal P16. Furthermore, the AND of the control signal P11 and the inverted signal of the control signal P12 may be used as the control signal P10. As the second modification, the inverted signals of the control signals P11, P13, and P15 may be used as the control signals P12, P14, and P16, respectively. In addition, the control signal P11 may be used as the control signal P10. As the third modification, the control signal P12 may be the control signal P14 or the inverted signal of the control signal P11. The control signal P11 may be used as the control signal P13, and the inverted signal of the control signal P15 may be used as the control signal P16. In addition, the control signal P11 may be used as the control signal P10. FIG. 7 shows a booster circuit of the second embodiment. An even number of, i.e., four pump circuits PC each constituted by a diode D and a capacitor CP are connected. The driving nodes of odd-numbered pump circuits, i.e., in FIG. 7, the driving node of a pump circuit constituted by a diode D1 and a capacitor CP1 and that of a pump circuit constituted by a diode D3 and a capacitor CP3 are connected at a driving node n71. The driving nodes of even-numbered pump circuits, i.e., in FIG. 7, the driving node of a pump circuit constituted by a diode D2 and a capacitor CP2 and that of a pump circuit constituted by a diode D4 and a capacitor CP4 are connected at a driving node n72. The driving nodes 71 and 72 are connected to the two terminals of a switch TSW71. Opening/closing of the switch TSW71 is controlled by a clock φ2. This clock φ2 corresponds to the above-described control signal P0 or P10. A node driving circuit 10 is constituted by drivers DT1 and DT2 and has the same internal arrangement as that shown in FIG. 5. The timing charts of this node driving circuit are the same as those of FIGS. 6A to 6I. A signal φ1 corresponds to the signal P11 in FIG. 6B, and a signal φ corresponds to the signal P15 in FIG. 6F. The connection relationship in the booster circuit shown in FIG. 7 will be described. The anode side of the diode D1 is connected to a power supply Vcc while the cathode side is connected to the capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of the diode D2 is connected to the node N1 while the cathode side is connected to the capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third and fourth pump circuits respectively constituted by the diodes D3 and D4 and the capacitors CP3 and CP4 are connected in series. The other end of each of the odd-numbered capacitors CP1 and CP3 counted from the first pump circuit is connected to the driving node n71. The other end of each of the even-numbered capacitors CP2 and CP4 counted from the first pump circuit is connected to the driving node n72. The driving nodes n71 and n72 are connected by the switch TSW71. The clock φ2 is applied to the gate of the switch TSW71. The driving nodes n71 and n72 are connected to the outputs from the drivers DT1 and DT2 of the node driving circuit 10 and driven by clocks CK1 and CK2 output from the drivers DT1 and DT2. The operation of the booster circuit shown in FIG. 7 will be described next with reference to the timing charts of FIGS. 6A to 6I. For the descriptive convenience, assume that the power supply voltage Vcc is 4 V, the capacitors CP1 to CP4 have the same capacitance value as that of a load capacitor CL, the threshold value of the diodes D1 to D5 is 0 V, and the low and high levels of the clocks CK1 and CK2 are 0 V and 4 V, respectively, as in FIG. 1. The frequency of the clocks CK1 and CK2 and the phase difference therebetween are the same as those shown in FIGS. 6H and 6I. When the clock CK1 or CK2 changes from high level to low level or from low level to high level, the driving nodes n71 and n72 are set in a floating state by the signals φ1 and φ1 (bar) (the inverted signal of φ will be referred to as φ hereinafter). The control signal φ2 has a frequency twice higher than that of the clocks CK1 and CK2 and goes high when the clocks CK1 and CK2 are set in the floating state. The high-level period of the control signal φ2 does not overlap the high- and low-level periods of the clocks CK1 and CK2. The operation at transient times T5 to T8 will be described below. At time T5 in FIGS. 6A to 6I, the clock CK1 of the node driving circuit 10 goes high (4 V), and the clock CK2 does low (0 V). When the clock CK1 changes to 4 V, the voltage at the driving node n71 changes from 2 V to 4 V. This voltage difference of 2 V is added to nodes N1 and N3. If the potential at the node N1 is higher than that at the node N2, or if the potential at the node N3 is higher than that at a node N4, charges at the node N1 or N3 immediately move to the node N2 or the nodes N4 and NL side. As a result, charges corresponding to 2 V added to the capacitors CP1 and CP3 are distributed to the capacitors CP2, CP4, and CL, thus boosting an output voltage Vob. When the clock CK2 changes to 0 V, the voltage at the driving node n72 lowers from 2 V to 0 V. The voltage difference of 2 V is subtracted from the nodes N2 and N4. If the potential at the node N2 is lower than that at the preceding node N1 or if the potential at the node N4 is lower than that at the preceding node N3, charges are immediately transferred from the node N1 or N3 to boost the voltage. The charges corresponding to 2 V, which are stored in the capacitors CP2 and CP4, are removed through the driver DT2. The loss charge amount is C×Vcc/2×2, i.e., C×Vcc. At time T6, when the switch TSW71 is closed, charges on the driving node n71 side of the capacitors CP1 and CP3 move to the driving node n72 side of the capacitors CP2 and CP4 through the switch TSW71, so the driving nodes n71 and n72 are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Accordingly, the voltage at the nodes N1 and N3 lowers because of removal of charges corresponding to 2 V. However, since the nodes N1 and N3 are charged by the power supply Vcc or capacitors at the preceding stages through the diodes D1 and D3, the voltage at the node N1 and N3 does not become lower than 4 V. The voltage at the nodes N2 and N4 increases and then stabilizes at a predetermined level because charges in the capacitor CP2 are distributed to the node N3 side, and charges in the capacitor CP4 are distributed to the load capacitor CL, so the voltage stabilizes at a predetermined level. Therefore, the output voltage Vob is also set at a predetermined level and maintains this voltage by the load capacitor CL. At time T7, when the clock CK1 is set at 0 V, charges on the driving nodes n71 and n72 sides of the capacitors CP1 and CP3, which correspond to 2 V, are removed through the driver DT1, so the voltage at the node N1 and N3 lowers by 2 V. However, the nodes N1 and N3 are charged from the power supply Vcc and the capacitors at the preceding stages through the diodes DI and D3, so the voltage does not become lower than 4 V. n , On the other hand, when the clock CK2 is set at 4 V, the driving node n72 is charged from 2 V to 4 V, so the voltage at the nodes N2 and N4 rises. If the voltage is higher than the potential at the subsequent stage, charges at the node N2 are distributed to the node N3 side, and charges at the node N4 are distributed to the load capacitor CL on the node NL side through the diode D5, so the voltage stabilizes at a predetermined level. Therefore, the output voltage Vob is also set at the predetermined level and maintains this level by the load capacitor CL. Charges stored in the capacitors CP1 and CP3, which correspond to 2 V, are removed through the driver DT2, so the loss charge amount is C×Vcc/2×2, i.e., C×Vcc. At time T8, the driving nodes n71 and n72 are electrically connected by the switch TSW71. Charges at the driving node n72, which correspond to 4 V, move to the driving node n71 side, so both the driving nodes n71 and n72 are set at 2 V. The voltage at the nodes N1 and N3 rises by 2 V. If the voltage is higher than the voltage at the subsequent nodes N2 and N4, charges move to the node N4 and NL sides, and the voltage stabilizes at a predetermined level. Since the voltage at the driving node n72 changes from 4 V to 2 V, the voltage level at the nodes N2 and N4 lowers by 2 V. However, if the voltage is lower than that at the subsequent nodes N1 and N3, charges are distributed from the capacitors CP1 and CP3, as described above, so the voltage level increases. As described above, the voltage at the nodes N2 to N4 and the output voltage Vob at the node NL rise in accordance with the operation from time T5 to time T8. The reverse flow of charges at the nodes N2 to N4 and NL to the pump circuit sides at the preceding stages is inhibited by the diodes D2 to D5, respectively, and the high voltage is held. From time T9, the same operation as that from time T5 to time T8 is repeated, and finally, a voltage five times higher than the power supply voltage Vcc can be obtained at the node NL. In the booster circuit shown in FIG. 7, by controlling the voltage at the driving nodes n71 and n72 by the outputs from the drivers DT1 and DT2 in the node driving circuit 10, respectively, a voltage five times higher than the power supply voltage Vcc can be obtained as the output voltage Vob. That is, letting m be the number of pump circuits, a voltage (m+1) times higher than the power supply voltage can be obtained. When the switch TSW71 is closed to electrically connect the driving nodes n71 and n72, charges in the capacitors CP1 and CP3 or charges in the capacitors CP2 and CP4 are transferred to the other side before discharge, so the loss charge amount due to discharge can be halved. In this embodiment, the loss charge amount for one period is 2×C×Vcc (coulomb). FIG. 8 shows a booster circuit of the third embodiment. In the booster circuit shown in FIG. 8, an odd number of pump circuits are connected, and in this example, five pump circuits are connected. With this arrangement, a voltage six times higher than a power supply voltage Vcc can be obtained as an output voltage Voc. In the booster circuit shown in FIG. 8, the driving nodes of odd-numbered pump circuits and those of subsequent even-numbered pump circuits are connected by two switches TSW81 and TSW82. In addition, drivers (tristate inverters) DT1 to DT5 for driving driving nodes n81 to n85 are independently arranged for the corresponding driving nodes. The connection relationship in the booster circuit shown in FIG. 8 will be described. The anode side of a diode D1 is connected to the power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third, fourth, and fifth pump circuits respectively constituted by the diodes D3, D4, and D5 and the capacitors CP3, CP4, and CP5 are connected in series. The other terminal of each of the capacitors CP1 to CP5 of the pump circuits is connected to a corresponding one of the driving nodes n81 to n85. The driving nodes n81 and n83 each connected to the other terminal of a corresponding one of the odd-numbered capacitors CP1 and CP3 counted from the first pump circuit and the driving nodes n82 and n84 each connected to the other terminal of a corresponding one of the even-numbered capacitors CP2 and CP4 counted from the first pump circuit are connected to the terminals of the switches TSW81 and TSW82, respectively. A clock φ2 is applied to the gates of the switches TSW81 and TSW82. The driving nodes n81 to n84 connected to the first to fourth pump circuits are connected to the outputs of the drivers DT1 to DT4 in a node driving circuit 10, respectively, and driven by a clock CK1 or CK2 independently output from the drivers DT1 to DT4. The driving node n85 connected to the capacitor CP5 of the fifth pump circuit is connected to the driver DT5 in the node driving circuit 10 and driven by the clock CK1 output from the driver DT5. The operation of the booster circuit shown in FIG. 8 will be described next with reference to the timing charts of FIGS. 6A to 6I. For the descriptive convenience, conditions such as the voltages of the circuits, the capacitances of the capacitors, and the clock timings are assumed to be the same as those in FIG. 7. The operation at transient times T5 to T8 will be described below. At time T6 in FIGS. 6A to 6I, when the clock CK1 is set at 4 V, the driving nodes n81 and n83 change from 2 V to 4 V, and the voltage at the driving node n85 changes from 0 V to 4 V. A voltage corresponding to this voltage difference is added to the nodes N1, N3, and N5. If the potential at the nodes N1, N3, and N5 is higher than that at the subsequent nodes, charges immediately move to the subsequent node sides. As a result, charges added to the capacitors CP1, CP3, and CP5 are distributed to the capacitors CP2, CP4, and CL, so the output voltage Voc is boosted. When the clock CK2 is set at 0 V, the driving nodes n82 and n84 change from 2 V to 0 V, and this voltage difference of 2 V is subtracted from the voltage at the nodes N2 and N4. If the potential at the nodes N2 and N4 is lower than that at the preceding nodes, charges are immediately transferred from the preceding capacitors to boost the voltage. Since charges stored in the capacitors CP2 and CP4, which correspond to 2 V, are removed through the drivers DT2 and DT4, respectively, the loss charge amount is C×Vcc/2×2, i.e., C×Vcc. At time T6, when the switches TSW81 and TSW82 are closed, charges in the capacitors CP1 and CP3 move to the driving nodes n82 and n84 sides of the capacitors CP2 and CP4, respectively, to set the driving nodes n82 and n84 at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Accordingly, the voltage at the nodes N1 and N3 lowers by 2 V. When the voltage is lower than the power supply voltage or voltage at the preceding nodes, the nodes N1 and N3 are charged from the power supply Vcc or the preceding stages, so the voltage does not become lower than 4 V. The voltage at the nodes N2 and N4 rises and then stabilizes at a predetermined level because charges in the capacitor CP2 are distributed to the node N3 side, and charges in the capacitor CP4 are distributed to the capacitors CP5 and CL side. At time T7, the clock CK1 is set at 0 V. Charges on the driving nodes n81 and n83 sides of the capacitors CP1 and CP3 are removed through the drivers DT1 and DT3, respectively, so the voltage at the nodes N1 and N3 lowers by 2 V. Charges on the driving node n85 side of the capacitor CP5 are removed through the driver DT5, so the voltage at the node N5 lowers by 4 V. When the voltage at the nodes N1, N3, and N5 is lower than the voltage at the preceding stages, charges are immediately transferred from the power supply Vcc or the preceding stages, so the voltage does not become lower than the Vcc level of 4 V. When the clock CK2 is set at 4 V, the driving nodes n82 and n84 of the capacitors CP2 and CP4 are charged from 2 V to 4 V, and the voltage level at the nodes N2 and N4 rises. However, charges at the node N2 are distributed to the node N3 side, and charges at the node N4 are distributed to the nodes N5 and NL side, so the voltage stabilizes at a predetermined level. Charges stored in the capacitors CP1 and CP3, which correspond to 2 V, are removed through the drivers DT1 and DT3, respectively. Charges stored in the capacitor CP5, which correspond to 4 V, are removed through the driver DT5. The loss charge amount is C×Vcc/2×2+C×Vcc, i.e., 2×C×Vcc (coulomb). At time T8, the switches TSW81 and TSW82 are turned on to set the respective driving nodes at 2 V. Charges corresponding to 2 V are stored at the nodes N1 and N3. Accordingly, the voltage at these nodes increases and then stabilizes at a predetermined level because charges are distributed to the node N2 side and the nodes N4 and N5 side. At this time, the voltage level at the nodes N2 and N4 lowers by 2 V. However, as described above, when the voltage is lower than that at the preceding stages, charges are distributed from the capacitors CP1 and CP3 to increase the voltage. As described above, the voltage at the nodes N2 to N5 and the output voltage Vob at the node NL rise in accordance with the operation from time T5 to time T8. The reverse flow of charges at the nodes N2 to N5 and NL to the preceding pump circuit sides is inhibited by the diodes D2 to D6, respectively, and the high voltage is held. The same operation from time T5 to time T8 is repeated from time T9. By applying the clock voltage to the boosted voltage held by the operation from time T5 to time T8, a voltage six times higher than the power supply voltage Vcc can be finally obtained from the node NL. In this arrangement as well, the same operation as that of the booster circuit shown in FIG. 7 is performed. The loss charge amount for one period due to discharge is 3×C×Vcc (coulomb). In the absence of the switches TSW81 and TSW82, the loss charge amount is 5×C×Vcc (coulomb). In this embodiment, the loss charge amount can be reduced to 60%. Generally, letting K be the number of pump circuits, and assuming that only one pump circuit does not recycle charges, the loss charge amount for one period is given by (K+1)/2×C×Vcc (coulomb). As compared to a case wherein charges are not recycled, the loss can be reduced to (k+1)/2K. In addition, since the output lines of the node driving circuit 10 need not be led, noise can be reduced. Simultaneously, since excess wiring lines can be omitted, the circuit layout can be easily designed. Furthermore, since the charge/discharge path between capacitors CP can be shortened using the two switches TSW, the high-level period of the signal φ2 can be shortened. In addition, as compared to an arrangement using one switch, a smaller-size transistor can be used. FIG. 9 shows a booster circuit of the fourth embodiment. In the booster circuit shown in FIG. 9, five (odd number) pump circuits are connected, like FIG. 8. Therefore, a voltage six times higher than a power supply voltage Vcc can be obtained as an output voltage Vod. In this booster circuit, the driving nodes of even-numbered pump circuits and those of subsequent odd-numbered pump circuits are connected by two switches TSW91 and TSW92. In addition, drivers DT1 to DT5 for driving driving nodes n91 to n95 are independently arranged for corresponding driving nodes. The connection relationship in the booster circuit shown in FIG. 9 will be described. The anode side of a diode D1 is connected to the power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third, fourth, and fifth pump circuits respectively constituted by the diodes D3, D4, and D5 and the capacitors CP3, CP4, and CP5 are connected in series. The other terminal of each of the capacitors CP1 to CP5 of the pump circuits is connected to a corresponding one of the driving nodes n91 to n95. The driving nodes n92 and n94 each connected to the other terminal of a corresponding one of the even-numbered capacitors CP2 and CP4 counted from the first pump circuit and the driving nodes n93 and n95 each connected to the other terminal of a corresponding one of the odd-numbered capacitors CP3 and CP5 counted from the first pump circuit are connected through switches TSW91 and TSW92, respectively. A clock φ2 is applied to the gates of the switches TSW91 and TSW92. The driving node n91 to n95 respectively connected to the first to fifth pump circuits are connected to the outputs of the drivers DT1 to DT5 in a node driving circuit 10. Each of the drivers DT1, DT3, and DT5 independently outputs a signal corresponding to a clock CK1 shown in FIG. 6H. Each of the drivers DT2 and DT4 independently outputs a signal corresponding to a clock CK2 shown in FIG. 6I. The operation of the booster circuit shown in FIG. 9 will be described next with reference to the timing charts of FIGS. 6A to 6I. For the descriptive convenience, conditions such as the voltages of the circuits, the capacitances of the capacitors, and the clock timings are assumed to be the same as those in FIG. 7. The operation at transient times T5 to T8 will be described below. At time T5 in FIGS. 6A to 6I, the clock CK1 of the node driving circuit 10 is set at 4 V. A voltage of 2 V is added to nodes N3 and N5, and a voltage of 4 V is added to the node N1, so the voltage rises. When the potential at the subsequent stages is lower, charges flow to the subsequent stages, so charges added to the capacitors CP1, CP3, and CP5 are distributed to the capacitors CP2, CP4, and CL. On the other hand, when the clock CK2 is set at 0 V, charges stored in the capacitors CP2 and CP4, which correspond to 2 V, are removed through the drivers DT2 and DT4, respectively. The loss charge amount at this time is C×Vcc/2×2, i.e., C×Vcc (coulomb). According to this discharge, a voltage of 2 V is subtracted from the voltage at the nodes N2 and N4. When the potential at the preceding stages is higher, charges are distributed from the preceding stages to the capacitors CP2 and CP4. At time T6, when the switches TSW91 and TSW92 are closed, charges in the capacitors CP3 and CP5 move to the sides of the driving nodes n92 and n94 of the capacitors CP2 and CP4, so all the driving nodes n92 to n95 are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. The voltage at the nodes N2 and N4 rises by 2 V, and the voltage at the nodes N3 and N5 lowers by 2 V. When the voltage is lower than that at the preceding stages, the nodes are charged from the power supply Vcc or the preceding stages through diodes D, so the voltage does not become lower than 4 V. At time T7, when the clock CK1 is set at 0 V, charges on the sides of the driving nodes n93 and n95 of the capacitors CP3 and CP5, which correspond to 2 V, are removed through the drivers DT3 and DT5, respectively, so the voltage at the nodes N3 and N5 lowers by 2 V. In addition, charges corresponding to 4 V are removed from the driving node n91 through the driver DT1, so the voltage at the node N1 lowers by 4 V. On the other hand, when the clock CK2 is set at 4 V, the driving nodes of the capacitors CP2 and CP4 are charged from 2 V to 4 V, so the voltage level at the nodes N2 and N4 rises. When the voltage at the nodes is lower than the voltage at the preceding stages, charges are distributed from the preceding stages to the subsequent stages, so the voltage stabilizes at a predetermined level. Therefore, the output voltage Vod is also set at the predetermined level and maintains this level by the load capacitor CL. The loss charge amount at this time is 2×C×Vcc (coulomb). At time T8, when the switches TSW91 and TSW92 are turned on, all the driving nodes are set at 2 V. Charges corresponding to 2 V are stored at the nodes N3 and N5. The voltage increases and then stabilizes at a predetermined level because the charges are distributed to the node N4 side and the node NL side. No charges are lost at this time. As described above, the voltage at the nodes N1 to N5 and the output voltage Vod at the node NL rise in accordance with the operation from time T5 to time T8. The reverse flow of charges at the nodes N1 to N5 and NL to the pump circuit sides at the preceding stages is inhibited by the diodes D1 to D6, respectively, and the high voltage is held. The same operation from time T5 to time T8 is repeated from time T9. By applying the clock voltage to the boosted voltage held by the operation from time T5 to time T8, a voltage six times higher than the power supply voltage Vcc can be finally obtained from the node NL. In the booster circuit shown in FIG. 9, the loss charge amount can be reduced to 60%, and since excess wiring lines can be omitted, the circuit layout can be easily designed, like the circuit shown in FIG. 8. Furthermore, since the charge/discharge path between capacitors CP can be shortened using the two transistors TSW, the high-level period of the signal φ2 can be shortened. In addition, as compared to an arrangement using one switch, a smaller-size transistor can be used. FIG. 10 shows a booster circuit of the fifth embodiment. In the booster circuit shown in FIG. 10, five (odd number) pump circuits are connected, as in FIG. 9. Therefore, a voltage six times higher than a power supply voltage Vcc can be obtained as an output voltage Voe. In this booster circuit, the driving nodes of pump circuits are connected by four switches TSW101 and TSW104. In addition, drivers DT1 to DT5 for driving the driving nodes are independently arranged for corresponding driving nodes. The connection relationship in the booster circuit shown in FIG. 10 will be described. The anode side of a diode D1 is connected to the power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third, fourth, and fifth pump circuits respectively constituted by the diodes D3, D4, and D5 and the capacitors CP3, CP4, and CP5 are connected in series. The other terminal of each of the capacitors CP1 to CP5 of the pump circuits is connected to a corresponding one of the driving nodes n101 to n105. The driving nodes n101 to n105 are connected through switches TSW101 to TSW104. A clock φ2 is commonly applied to the gates of the switches TSW101 to TSW104. Each of the drivers DT1, DT3, and DT5 independently outputs a signal corresponding to a clock CK1 shown in FIG. 6H, and each of the drivers DT2 and DT4 independently outputs a signal corresponding to a clock CK2 shown in FIG. 6I to drive the driving nodes n101 to n105, respectively. The operation of the booster circuit shown in FIG. 10 will be described next with reference to the timing charts of FIGS. 6A to 6I. For the descriptive convenience, conditions such as the voltages of the circuits, the capacitances of the capacitors, and the clock timings are assumed to be the same as those in FIG. 7. The operation at transient times T5 to T8 will be described below. At time T5 in FIGS. 6A to 6I, when the clock CK1 of the node driving circuit 10 is set at 4 V, the voltage at the driving nodes n101, n103, and n105 rises from 1.6 V to 4 V. On the other hand, when the clock CK2 is set at 0 V, the voltage at the nodes n102 and n104 lowers from 1.6 V to 0 V. Accordingly, the voltage at the nodes N1, N3, and N5 rises by 2.4 V, and the voltages at the nodes N2 and N4 lowers by 1.6 V. If the voltage is lower than the voltage at the preceding stages, charges are immediately supplied from the power supply Vcc or the nodes at the preceding stages, so the voltage stabilizes at a predetermined level. Charges stored in the capacitors CP2 and CP4, which correspond to 1.6 V, i.e., 2/5×Vcc are removed through the drivers DT2 and DT4. The loss charge amount is C×(2/5×Vcc)×2, i.e., 4/5×C×V (coulomb). At time T6, when the switches TSW101 to TSW104 are closed, charges on the sides of the driving nodes n101, n103, and n105 of the capacitors CP1, CP3, and CP5 move to the sides of the driving nodes n102 and n104 of the capacitors CP2 and CP4 through the switches TSW101 to TSW104, so all the driving nodes n101 to n105 are set at 2.4 V, i.e., 3/5×Vcc. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Accordingly, the voltage at the nodes N1, N3, and N5 lowers by 2.4 V, and the voltage at the nodes N2 and N4 rises by 2.4 V. Charges are transferred from the preceding stage to the subsequent stages in a similar manner, so the voltage stabilizes at a predetermined level. At time T7, when the clock CK1 is set at 0 V, charges on the driving node sides of the capacitors CP1, CP3, and CP5, which correspond to 2.4 V, i.e., 3/5×Vcc are removed through the drivers DT1, DT3, and DT5, so the voltage at the nodes N1, N3, and N5 lowers by 2.4 V. On the other hand, when the clock CK2 is set at 4 V, the driving nodes n102 and n104 of the capacitors CP2 and CP4 are charged from 2.4 V to 4 V, so the voltage level at the node N2 and N4 rises by 1.6 V. In this case as well, charge transfer occurs, and the voltage stabilizes at a predetermined level. Therefore, the output voltage Voe also increases and maintains its level by a load capacitor CL. The loss charge amount due to discharge is C×(3/5×Vcc)×3, i.e., 9/5×C×Vcc (coulomb). At time T8, when the switches TSW101 to TSW104 are turned on, charges stored in three capacitors, which correspond to 4 V, are distributed to five capacitors. All the driving nodes are set at 1.6 V, i.e., 4/5×Vcc. The voltage at the nodes N1, N3, and N5 increases by 1.6 V, and the voltage at the nodes N2 and N4 lowers by 2.4 V. However, since charges are distributed, the voltage stabilizes at a predetermined level. As described above, the voltage at the nodes N2 to N5 and the output voltage Vod at a node NL rise in accordance with the operation from time T5 to time T8. The reverse flow of charges at the nodes N2 to N5 and NL to the preceding pump circuit sides is inhibited by the diodes D2 to D6, respectively, and the high voltage is held. The same operation from time T5 to time T8 is repeated from time T9. By applying the clock voltage to the boosted voltage held by the operation from time T5 to time T8, a voltage six times higher than the power supply voltage Vcc can be finally obtained from the node NL. In the booster circuit shown in FIG. 10, the loss charge amount for one period is (4/5+9/5)×C×Vcc, i.e., 13/5×C×Vcc (coulomb). In the absence of the switches TSW101 to TSW104, the loss charge amount is 5×C×Vcc (coulomb). In this embodiment, the loss charge amount can be reduced to 52%. Generally, when an odd number L of pump circuits are used, and charges in each pump circuit are commonly recycled, the loss charge amount for one period is given by (L 2 +1)/2L×C×Vcc (coulomb). As compared to a case wherein charges are not recycled, the loss can be reduced to (L 2 +1)/2L 2 . In this embodiment, even when an odd number of pump circuits are used, charges of each stage can be recycled by arranging switches between the driving nodes, so the increase in power consumption of the circuit can be further suppressed. In addition, since the length of the interconnection for connecting the driving nodes and the switches is minimized, noise can be prevented, and the circuit layout can be easily designed. FIG. 11 shows a booster circuit of the sixth embodiment. In the booster circuit shown in FIG. 11, five (odd number) pump circuits are connected, as in FIG. 9. One terminal of each of switches TSW is connected to a corresponding one of the driving nodes of the pump circuits, and the other terminal of each of the switches is commonly connected. The connection relationship in the booster circuit shown in FIG. 11 will be described. The anode side of a diode D1 is connected to a power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third, fourth, and fifth pump circuits respectively constituted by the diodes D3, D4, and D5 and the capacitors CP3, CP4, and CP5 are connected in series. The other terminal of each of the capacitors CP1 to CP5 of the pump circuits is connected to a corresponding one of driving nodes n111 to n115. One terminal of each of switches TSW111 to TSW115 is connected to a corresponding one of the driving nodes n111 to n115, and the other terminal of each of the switches TSW111 to TSW115 is commonly connected. A clock φ2 is commonly applied to the gates of the switches TSW111 to TSW115. Each of the driving nodes n111 to n115 is connected to the output of a corresponding one of drivers DT1 to DT5 in a node driving circuit 10. each of the drivers DT1, DT3, and DT5 outputs a signal corresponding to a clock CK1 shown in FIG. 6H to drive the driving nodes n111, n113, and n115. Each of the drivers DT2 and DT4 outputs a signal corresponding to a clock CK2 shown in FIG. 6I to drive the driving nodes n112 and n114. The operation of the booster circuit shown in FIG. 11 will be described next with reference to the timing charts of FIGS. 6A to 6T. For the descriptive convenience, conditions such as the voltages of the circuits, the capacitances of the capacitors, and the clock timings are assumed to be the same as those in FIG. 7. The operation at transient times T5 to T8 will be described below. At time T5, when the clock CK1 of the node driving circuit 10 is set at 4 V, the voltage at the driving nodes n111, n113, and n115 changes from 1.6 V to 4 V. Since a voltage of 2.4 Vis added to the nodes N1, N3, and N5, the voltage rises. On the other hand, when the clock CK2 is set at 0 V, the voltage at the nodes n112 and n114 changes from 1.6 V to 0 V, so the voltage at the nodes N2 and N4 lowers by 1.6 V. When the voltage at the nodes is lower than that at the preceding stages, charges immediately move from the power supply Vcc or the capacitors at the preceding stages. The voltage converges to a predetermined level. Charges stored on the sides of the driving nodes n112 and n114 of the capacitors CP2 and CP4, which correspond to 1.6 V, i.e, 2/5×Vcc are removed through the drivers DT2 and DT4. The loss charge amount is C×(2/5×Vcc)×2, i.e., 4/5×C×Vcc (coulomb). At time T6, when the switches TSW111 to TSW115 are closed, charges in the capacitors CP1, CP3, and CP5 move to the sides of the driving nodes n112 and n114 of the capacitors CP2 and CP4 through the switches TSW111 to TSW115, so all the driving nodes n111 to n115 are set at 2.4 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. The voltage at the nodes N1, N3, and N5 lowers by 1.6 V, and the voltage at the nodes N2 and N4 rises by 2.4 V. When the voltage at the subsequent stages is lower, charges move, and the voltage converges to a predetermined level. At time T7, when the clock CK1 is set at 0 V, charges on the driving node sides of the capacitors CP1, CP3, and CP5, which correspond to 2.4 V, are removed through the drivers DT1, DT3, and DT5, so the voltage at the nodes N1, N3, and N5 lowers by 2.4 V. On the other hand, when the clock CK2 is set at 4 V, the driving nodes of the capacitors CP2 and CP4 are charged from 2.4 V to 4 V, so the voltage level at the nodes N2 and N4 rises by 1.6 V. After this, when the voltage at the subsequent stages is lower, charges move, and the voltage converges to a predetermined level. Therefore, an output voltage Vof also increases and maintains this level by a load capacitor CL. The loss charge amount due to discharge is C×(3/5×Vcc)×3, i.e., 9/5×C×Vcc (coulomb). At time T8, when the switches TSW111 to TSW115 are turned on, charges stored on the sides of the driving nodes n112 and n114 of the capacitors CP2 and CP4, which correspond to 4 V, are distributed to the capacitors CP1 to CP5, so all the driving nodes n111 to n115 are set at 1.6 V. Charges corresponding to 1.6 V are stored at the nodes N1, N3, and N5 to increase the voltage. The voltage at the nodes N2 and N4 lowers by 2.4 V. However, when the voltage at the subsequent stages is lower, charges are distributed, and the voltage stabilizes at a predetermined level. As described above, the output voltage Vof rises in accordance with the operation from time T5 to time T8, and the boosted voltage is held by the load capacitor CL. The same operation from time T5 to time T8 is repeated from time T9. By applying the clock voltage to the boosted voltage already held at the nodes N2 to N4 and NL by the operation from time T5 to time T8, a voltage six times higher than the power supply voltage Vcc can be finally obtained. In the booster circuit shown in FIG. 11, the loss charge amount for one period is (4/5+9/5)×C×Vcc, i.e., 13/5×C×Vcc (coulomb), as in the booster circuit shown in FIG. 10. In the absence of the switches TSW111 to TSW115, the loss charge amount is 5×C×Vcc (coulomb). In this embodiment, the loss charge amount can be reduced to 52%. Each of the drivers DT1 to DT5 of the circuit shown in FIG. 11 also has a function of temporarily setting the output terminal in a floating state when the output level is to be switched. When the output terminal is set in the floating state, the switches TSW111 to TSW115 are turned on to short-circuit the output terminals of the drivers DT1 to DT5. Since charges removed from the capacitors CP can be recycled as charges to be stored, the power consumption can be decreased, and charge transfer between the capacitors CP can be more quickly performed than in the circuit of the fifth embodiment shown in FIG. 10. In addition, since the amount of charges flowing to one switch TSW (transistor) becomes small, the transistor size can be decreased. Furthermore, since the switches TSW can be arranged independently of the arrangement of the pump circuits, the degree of freedom in designing the mask layout increases, and this arrangement can be effectively applied to an odd number of pump circuits. FIG. 12 shows a booster circuit of the seventh embodiment. FIGS. 13A to 13D show the operation timings of various portions of the circuit. In the booster circuit shown in FIG. 12, four (even number) pump circuits are connected. One of driving nodes is charged with a power supply voltage, and these charges are used to drive the other driving node. The connection relationship in the booster circuit shown in FIG. 12 will be described. The anode side of a diode D1 is connected to a power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third and fourth pump circuits respectively constituted by the diodes D3 and D4 and the capacitors CP3 and CP4 are connected in series. The other terminal of each of the capacitors CP1 and CP3 at the odd-numbered stages counted from the first pump circuit is connected to a driving node n121. The other terminal of each of the capacitors CP2 and CP4 at the even-numbered stages counted from the first pump circuit is connected to a driving node n122. The two terminals of a switch TSW121 are connected to the driving nodes n121 and n122. A clock φ122 is applied to the control terminal of the switch TSW121. A node driving circuit 10 is constituted by a PMOS transistor MOS31 and an NMOS transistor MOS32. The source of the transistor MOS31 is connected to the power supply Vcc, the drain is connected to the driving node n121, and the gate is connected to a control signal φ121. The drain of the transistor MOS32 is connected to the driving node n122, the source is connected to ground GND, and the gate is connected to a control signal φ121. The operation of the booster circuit shown in FIG. 12 will be described next with reference to the timing charts of FIGS. 13A to 13D. For the descriptive convenience, conditions such as the voltages of the circuits and the capacitances of the capacitors are assumed to be the same as those in FIG. 7. In FIGS. 13A to 13D, the control signals φ121 and φ121 have the same frequency and opposite phases. The control signal φ122 has the same frequency as that of the control signal φ121 and goes high when the control signal φ121 is at low level and the control signal φ121 is at high level. At time T130 in FIGS. 13A to 13D, the control signals φ121 and φ121 are at low and high levels, respectively (FIGS. 13A and 13B). Therefore, both the transistors MOS31 and MOS32 are turned off, and the driving nodes n121 and n122 are set at an intermediate potential of 2 V. When the control signal φ122 goes low (FIG. 13C), the switch TSW121 is turned off. At time T131, the control signals φ121 and φ121 go high and low, respectively (FIGS. 13A and 13B). Both the transistors MOS31 and MOS32 are turned on, the driving node n121 is set at 4 V, and the driving node n122 is set at 0 V. A voltage of 2 V is added to the nodes N1 and N3, and a voltage of 2 V is subtracted from the nodes N2 and N4. When the voltage at the subsequent stages is lower, charges at the nodes N1 to N4 immediately move to the subsequent node sides to increase an output voltage Vog. This voltage is held by a load capacitor CL. In this state, even when the control signals φ121 and φ121 are set at low and high levels, respectively, to turn off the drivers, the voltage level at the driving nodes n121 and n122 is maintained. At this time, charges of C×Vcc (coulomb) are lost, as will be described later. At time T132, when the control signal p122 goes high, the switch TSW121 is closed. Charges on the driving node n121 side of the capacitors CP1 and CP3 move to the driving node n122 side through the switch TSW121, so both the driving nodes n121 and n122 are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Since charges corresponding to 2 V are removed, the voltage at the nodes N1 and N3 lowers, and the voltage at the nodes N2 and N4 rises by 2 V. When the voltage at the subsequent stages is lower, each node is charged from the power supply Vcc or the preceding stage through the diode, so the voltage stabilizes at a voltage equal to or higher than the Vcc level of 4 V. Therefore, the output voltage Vog also increases and maintains this voltage by the load capacitor CL. Even when the control signal φ122 is set at low level to turn off the switch TSW121, the voltage level at the driving nodes n121 and n122 is held. At time T133 of the next period, when the control signals φ1 and φ1 are set at high and low levels, respectively, to turn on the transistors, the driving nodes n121 is set at 4 V, and the driving node n122 is set at 0 V. Charges stored in the capacitors CP2 and CP4, which correspond to 2 V, are removed through the transistor MOS32. The loss charge amount is C×Vcc/2×2, i.e., C×Vcc (coulomb). In this embodiment, discharge is performed once in a period. Therefore, the loss charge amount for one period is also C×Vcc (coulomb). Let J be the number of pump circuits, and when one driving node is charged to the power supply voltage to boost the voltage, and then these charges are moved to the other driving node and recycled, the loss charge amount for one period is given by (J/2)×C×Vcc/2, i.e., J×C×Vcc/4 (coulomb). Since the boosted voltage is given by (J+1)×Vcc/2, the loss charge amount per unit boost ratio is given by {J/2(J+1)}×C ×Vcc (coulomb). In this embodiment, an output voltage 2.5 times higher than the power supply voltage can be obtained with a simple node driving circuit constituted by two transistors. In addition, the loss charge amount per unit boost ratio can be halved as compared to prior art 1. FIG. 14 shows a booster circuit of the eighth embodiment. The circuit shown in FIG. 14 is a modification of the booster circuit shown in FIG. 12. Four (even number) pump circuits are connected, two sets of node driving circuits shown in FIG. 12 are arranged, and switches are inserted between driving nodes. The connection relationship in the booster circuit shown in FIG. 14 will be described. The anode side of a diode D1 is connected to a power supply Vcc while the cathode side is connected to a capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to a capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, a plurality of pump circuits, i.e., the third and fourth pump circuits respectively constituted by the diodes D3 and D4 and the capacitors CP3 and CP4 are connected in series. The other terminal of each of the capacitors CP1 to CP4 is connected to a corresponding one of driving nodes n141 to n144. The drains of PMOS transistors MOS31 and MOS33 are connected to the driving nodes n141 and n143, respectively, the sources are connected to the power supply Vcc, and the gates are connected to a control signal φ121 shown in FIG. 13B. The drains of NMOS transistors MOS32 and MOS34 are connected to the driving nodes n142 and n144, respectively, the sources are connected to ground GND, and the gates are connected to a control signal φ121 shown in FIG. 13A. The driving nodes n141 and n142 are connected by a switch TSW141, and the driving nodes n143 and n144 are connected by a switch TSW142. When the switches and drivers are controlled by control signals generated at timings shown in FIGS. 13A to 13C, the potential at each driving node can be changed, as shown in FIG. 13D. The driving nodes n141 and n143 correspond to the driving node n121, and the driving nodes n142 and n144 correspond to the driving node n122. The operation of the booster circuit shown in FIG. 14 will be described next with reference to the timing charts of FIGS. 13A to 13D. For the descriptive convenience, conditions such as the voltages of the circuits and the capacitances of the capacitors are assumed to be the same as those in FIGS. 7 and 13A to 13D. At time T130 in FIGS. 13A to 13D, since the control signals φ121 and φ121 are at low and high levels, respectively (FIGS. 13A and 13B), the drivers are turned off, and the driving nodes n141 to n144 are set at an intermediate potential of 2 V. When the control signal φ122 goes low (FIG. 13C), the switches TSW141 and TSW142 are turned off. At time T131, when the control signals φ121 and φ121 go high and low, respectively (FIGS. 13A and 13B), the transistors MOS31 to MOS34 are turned on. The driving nodes n141 and n143 are set at 4 V, and the driving nodes n142 and n144 are set at 0 V. A voltage of 2 V is added to the nodes N1 and N3, so the voltage level at the nodes N1 and N3 lowers by 2 V. When the voltage at the nodes of the preceding stages is higher, charges immediately move to the subsequent stages to boost an output voltage Voh, and this voltage is held by a load capacitor CL. In this state, even when the control signals φ121 and φ121 are set at low and high levels, respectively, to turn off the transistors and set the driving nodes in a floating state, this voltage level is maintained. The loss charge amount at this time is the same as that in FIG. 12, i.e., C×Vcc (coulomb). At time T132, when the control signal φ122 goes high to close the switches TSW141 and TSW142, charges in the capacitors CP1 and CP3 move to the sides of the driving nodes n142 and n144 through the switches TSW141 and TSW142, so the driving nodes are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Since charges corresponding to 2 V are removed, the voltage at the nodes N1 and N3 lowers, and the voltage at the nodes N2 and N4 increases by 2 V. When the voltage at the nodes of the preceding stages is higher, charges immediately move to the subsequent stages to boost the output voltage Voh, and this voltage is held by the load capacitor CL. Even when the control signal φ122 is set at low level to turn off the switches TSW141 and TSW142, the voltage levels at the driving nodes is maintained. From time T133 of the next period, the operation from time T131 to time T132 is repeated, and finally, a voltage 2.5 times higher than the power supply voltage Vcc is obtained as the output voltage Voh. In this embodiment, when the transistors MOS32 and MOS34 are turned on, the driving nodes n142 and n144 are set at 0 V. Charges stored in the capacitors CP2 and CP4, which correspond to 2 V, are removed through the transistors MOS32 and MOS34, respectively. For this reason, the loss charge amount is C×Vcc/2×2, i.e., C×Vcc (coulomb). In this embodiment, since discharge is performed once in a period, the loss charge amount for one period is also C×Vcc (coulomb). As described above, like the circuit shown in FIG. 12, a high output voltage can be obtained while maintaining a low power consumption. In addition, since two switches are used, the switches can be arranged close to the capacitors, and the length of the interconnection for connecting them can be minimized. Therefore, noise can be suppressed, and the area required for interconnection can be reduced. FIG. 15 shows a booster circuit of the ninth embodiment. Two structures each having three pump circuits connected in series are connected in parallel. Capacitors CP1, CP2, and CP3 recycle charges together with capacitors CP4, CP5, and CP6, respectively. Each of node driving circuits 11 to 13 outputs signals corresponding to clocks CK1 and CK2 shown in FIGS. 4F and 4G or FIGS. 6H and 6I, as in the first embodiment. The connection relationship in the booster circuit shown in FIG. 15 will be described. The anode side of a diode D1 is connected to a power supply Vcc while the cathode side is connected to the capacitor CP1 through a node N1, thereby constituting the first pump circuit. The anode side of a diode D2 is connected to the node N1 while the cathode side is connected to the capacitor CP2 through a node N2, thereby constituting the second pump circuit. In a similar manner, the third pump circuit constituted by a diode D3 and the capacitor CP3 is connected in series. On the other hand, the anode side of a diode D5 is connected to the power supply Vcc while the cathode side is connected to the capacitor CP1 through a node N4, thereby constituting the fourth pump circuit. The anode side of a diode D6 is connected to the node N4 while the cathode side is connected to the capacitor CP5 through a node N5, thereby constituting the fifth pump circuit. In a similar manner, the sixth pump circuit constituted by a diode D7 and the capacitor CP6 is connected in series. The other terminal of each of the capacitors CP1 to CP3 of the first to third pump circuits is connected to a corresponding one of driving nodes n151 to n153. The other terminal of each of the capacitors CP4 to CP6 of the fourth to sixth pump circuits is connected to a corresponding one of driving nodes n154 to n155. Each of the node driving circuits 11 to 13 is constituted by a circuit shown in FIG. 3 or 5 and has terminals for outputting the two signals CK1 and CK2. One output terminal of each of the node driving circuits 11 to 13 is connected to a corresponding one of the driving nodes n151, n155, and n153 to output a signal corresponding to the clock CK1. The other output terminal of each of the node driving circuits 11 to 13 is connected to a corresponding one of the driving nodes n154, n152, and n156 to output a signal corresponding to the clock CK2. The driving nodes n151 and n154 are connected by a switch TSW151. The driving nodes n152 and n155 are connected by a switch TSW152. The driving nodes n153 and n156 are connected by a switch TSW153. The clocks CK1 and CK2 in opposite phases are supplied to the driving nodes of the same stages of the parallelly connected pump circuits, e.g., the driving nodes n151 and n154 of the same stage. The operation of the circuit shown in FIG. 15 will be described next with reference to FIG. 2. The operation at transient times T5 to T8 will be described below. At time T5, when the clock CK1 rises to 4 V, a voltage of 2 V is added to the nodes N1, N5, and N3 to boost the voltage. When the clock CK2 falls to 0 V, a voltage of 2 V is subtracted from the nodes N4, N2, and N6 to lower the voltage. If the voltage at the subsequent stages is lower, charges immediately flow to the nodes at the next stages through the diodes to boost the output voltage. The reverse flow of this boosted voltage is inhibited by the diodes D4 and D8, so an output voltage Voi is held by a load capacitor CL. Charges stored on the sides of the driving nodes n154, n152, and n156 of the capacitors CP4, CP2, and CP6 are removed through the node driving circuits 11 to 13. Therefore, the loss charge amount is C×Vcc/2×3, i.e., 3/2×C×Vcc (coulomb). At time T6, when a control signal P0 goes high to close the switches TSW151 to TSW153, charges in the capacitors CP1, CP5, and CP3 move to the sides of the capacitors CP4, CP2, and CP6 through the switches TSW151 to TSW153, respectively. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. Accordingly, the voltage at the nodes N1, N5, and N3 lowers by 2 V, and the voltage at the nodes N4, N2, and N6 increases by 2 V. When the voltage at the subsequent stages is lower, charges immediately move to the nodes of the next stages through the diodes, so the voltage converges to a predetermined value. At time T7, when the clock CK1 is set at 0 V, and the clock CK2 is set at 4 V, the driving nodes n151, n155, and n153 are discharged from 2 V to 0 V, and the driving nodes n154, n152, and n156 are charged from 2 V to 4 V. The voltage at the nodes N1, N5, and N3 lowers by 2 V, and the voltage at the nodes N4, N2, and N6 rises by 2 V. However, when the voltage at the subsequent stages is lower, charges immediately flow from the power supply Vcc or the capacitors at the preceding stages to the nodes of the next stages through the diodes, so the voltage converges to a predetermined level. This boosted voltage is held by the load capacitor CL. Charges stored on the sides of the driving nodes n151, n155, and n153 of the capacitors CP1, CP5, and CP3 are removed through the node driving circuits 11 to 13, respectively. Therefore, the loss charge amount is C×Vcc/2×3, i.e., 3/2×C×Vcc (coulomb). At time T8, when the control signal P0 goes high to close the switches TSW151 to TSW153, charges in the capacitors CP4, CP2, and CP6 move to the sides of the capacitors CP1, CP5, and CP3 through the switches TSW151 to TSW153, respectively, so the driving nodes are set at 2 V. At this time, only charge movement occurs, and no charge loss, i.e., no power consumption is generated. The voltage at the nodes N1, N5, and N3 rises by 2 V, and the voltage at the nodes N4, N2, and N6 lowers by 2 V. When the voltage at the subsequent stages is lower, charges flow to the nodes of the next stages through the diodes, so the voltage converges to a predetermined level. From time T9, the operation from time T5 to time T8 is repeated to sequentially store charges in the load capacitor CL, so a high voltage of 16 V can be obtained. In this embodiment, structures each having three pump circuits connected in series are connected in parallel such that charges are recycles between the capacitors CP1 and CP4, between the capacitors CP2 and CP5, and between the capacitors CP3 and CP6. With this arrangement, charges flowing through the diodes D1 to D4 can be stored in the load capacitor CL in the first half of one period, and subsequently, charges flowing through the diodes D5 to D8 can be stored in the load capacitor CL in the second half of one period. Since the output voltage Voi is output twice in one period, a high voltage of 16 V can be obtained with a high current supply capability. In this embodiment, three node driving circuits are used. However, the driving nodes n151, n155, and n153 may be commonly connected, and the driving nodes n154, n152, and n156 may be commonly connected such that they can be driven by one node driving circuit. The switches TSW151 to TSW153 can also be integrated. In this embodiment, the driving nodes at the same stage of the parallelly connected pump circuits are connected by one of the switches TSW151 to TSW153. However, the present invention is not limited to this, and the switch can be arranged between any driving nodes as far as clocks in opposite phases are supplied to the driving nodes. For this reason, the degree of freedom in mask layout can be improved. In the first to ninth embodiments, the transistor switch TSW is constituted by a transistor. However, the present invention is not limited to this, and any switch, e.g., a transfer gate, can be used as far as it can be electrically opened/closed. As has been described above, according to the present invention, the booster circuit has the first pump circuit to which the power supply voltage is supplied, and the second pump circuit connected to the first pump circuit. To boost the power supply voltage, the node driving circuit outputs a driving signal to the capacitors of the pump circuits to charge the capacitors, and the charges are transferred to the other capacitor by a switch means. Therefore, the power consumption of the circuit can be reduced even when the boost ratio is increased. When the driving signal from the node driving circuit to the first and second capacitors represents a floating state, the control means controls the switch means to connect the driving nodes of the first and second capacitors. Since charges removed from the capacitor of the first pump circuit can be recycled as charges to be stored in the capacitor of the second pump circuit, a high-voltage generation circuit can be realized while halving the power consumption. In a plurality of stages of pump circuits including the first pump circuit and having a plurality of second pump circuits, the driving nodes of odd-numbered pump circuits counted from the first pump circuit are connected to each other, and the driving nodes of even-numbered pump circuits are connected to each other. With this arrangement, the power consumption of the circuit can be reduced even when the boost ratio is increased. In a plurality of pump circuits including the first pump circuit and having a plurality of second pump circuits, the driving nodes of two pump circuits are sequentially connected by a switch means, and opening/closing of the switch means is commonly controlled. With this arrangement, the length of wiring lines for connecting the capacitors and switches can be minimized. Therefore, noise can be suppressed, and the area necessary for interconnection can be reduced. In addition, the layout of the circuit can be easily designed. In a plurality of pump circuits having a plurality of second pump circuits and including the first pump circuit, a switch means is connected to each driving node, and opening/closing of the switch means is commonly controlled. Therefore, when a high voltage is to be generated, the number of input/output lines of each portion can be decreased, and consequently, the layout of the circuit can be easily designed. A plurality of pump circuit groups each comprising a plurality of pump circuits having a plurality of second pump circuits and including the first pump circuit are connected in parallel. The output voltage of each pump circuit group is obtained twice in one period. With this arrangement, a high voltage can be generated with a high current supply capability, and simultaneously, a circuit with a low power consumption can be realized.

The present invention relates to a booster circuit which uses multiple pump circuits to provide high voltages. The pump circuits are provided with an input voltage Vcc and are generally each made up of a diode and a capacitor. A node driving circuit provides driving signals to driving nodes and thereby to the pump circuits. The driving nodes are connected by a charge transfer switch which is selectively activated so as to allow charge that would otherwise be lost to ground to be conserved for inclusion in the final high-output voltage.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to German Application No. DE 20 2007 014 852.6 filed on Oct. 24, 2007 and German Application No. DE 10 2007 014 426.3 filed on Mar. 22, 2007, the contents of both of which are incorporated in their entirety herein by reference. BACKGROUND [0002] The present invention relates to devices for injecting, infusing, administering, delivering or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to a setting mechanism for preparing or setting a quantity or dose of a substance to be administered from an injection device, such as insulin for example. [0003] Injection devices for administering set or selected doses of a substance from a supply chamber or from an ampoule inserted in the injection device are known from the prior art. To set the exact quantity or dose of the substance contained in the injection device representing the quantity of substance that will be dispensed during an injection, the quantity of substance to be dispensed may be set by an adjusting element, which can be operated by a user and is usually a rotatable adjustable element. A set amount usually depends on the degree of the rotating movement, in other words the rotation angle of the adjusting element provided on the injection device. This being the case, the adjusting element can be rotated about the longitudinal axis of the injection device and, depending on the design of the injection device, the adjusting element is pushed or moved out of the injection device in the axial or longitudinal direction and screwed out for example, or alternatively is not pushed in the axial direction. [0004] A stop is usually provided to indicate a maximum dose or set a maximum dose, whereby a cam of an element connected to the adjusting element projecting radially outwardly is rotated onto a stop projecting radially inwardly which is not able to move during the setting movement and restricts the maximum dose. Turning the adjusting element any further would cause the mutually abutting stops or lugs to break or be deformed in the fully fitted state, for example. SUMMARY [0005] An object of the present invention is to provide an improved setting mechanism for setting or selecting a quantity of a substance to be dispensed from an injection device by which a maximum possible setting quantity can be predefined. [0006] In one embodiment, the present invention comprises a setting mechanism for setting or selecting a quantity of a substance to be dispensed from an injection device, the mechanism comprising a dose setting element and an adjusting element which can be operated by a user, wherein the adjusting element is operably coupled to the dose setting element, the mechanism further comprising an overstrain lock between the dose setting element and the adjusting element. [0007] In some preferred embodiments, in accordance with the present invention an adjusting mechanism for adjusting, selecting or setting a quantity or dose of substance to be dispensed from an injection device has a dose setting element which is able to slide and/or rotate relative to the injection device and which can be moved and/or rotated relative to the injection device, for example about the longitudinal axis of the injection device. The dose setting element is coupled with the injection device so that the quantity of the substance to be dispensed from the injection device is set depending on the angle of rotation, for example the number of rotations, of a dose setting sleeve serving as a dose setting element, which is rotated starting from a defined zero or initial state during the dose setting operation. This being the case, as the quantity of substance to be dispensed is higher or larger, the more or the further the dose setting element is rotated. [0008] In most known injection devices with a setting feature, there is a proportional relationship between the rotation of the dose setting element and the quantity of substance to be dispensed. The dose setting element may be designed so that it is pushed in the axial direction of the injection device during an adjusting movement or rotation and is turned out or screwed out, for example, and the axial offset of the dose setting element relative to the injection device during a dose setting or adjusting operation determines the plunger stroke or distance traveled by a displaceable stopper in an ampoule, for example, thereby determining the quantity of substance to be dispensed. The dose setting element is coupled with an adjusting element, which can be operated by a user in such a way that an adjusting movement or rotation of the adjusting element within a pre-definable dose setting range, starting from a zero position to a rotation position corresponding to less than a maximum dose, is transmitted to the dose setting element, for example. [0009] In accordance with the present invention, an overstrain lock is provided between the dose setting element and the adjusting element, which prevents or reduces transmission of a force or the transmission of a movement from an adjusting element operated by the user to the dose setting element if the dose setting element should not be rotated any further, for example because a maximum dose has been set. In some embodiments, a cam of the dose setting element lies against or abuts a stop which remains stationary in the injection device during the setting operation and is provided for restricting the dose which can be set, for example, and prevents any further rotation of the dose setting element. [0010] In some exemplary embodiments, the dose setting element may be provided in the form of a dose setting sleeve which is cylindrical in shape or has a sleeve-shaped or cylindrical region and extends into the injection device. The adjusting element may be provided in the form of a dose setting ring, which has a ring-shaped or disc-shaped element, connected to a sleeve-shaped projection which may be pushed into a sleeve-shaped region of the dose setting element. [0011] In one embodiment, the adjusting element, in other words the dose setting ring, can be rotated relative to the dose setting element when a relative force or a torque between the adjusting element and the dose setting element exceeds a minimum value predefined by the structural design. A rotating movement of the adjusting element can be transmitted to the dose setting element if the relative force or torque between the dose setting element and adjusting element is below the maximum force or maximum torque predefined by the structural design, which is preferably lower than the retaining force or a maximum torque still permitting transmission by which the dose setting element is retained in the injection device in a position turned out to the maximum so that it is prevented from turning further. When the adjusting element is rotated by an angle of 390° for example, this rotating movement of the adjusting element is transmitted to the dose setting element so that the dose setting element is also rotated by 390°. It is not until a predefined restriction occurs due to the structural design that the dose setting element is retained by this restriction and further rotation of the dose setting element is prevented, as a result of which the coupling between the dose setting element and the adjusting element is released if the adjusting element is rotated any further and a rotation of the adjusting element can no longer be transmitted to the dose setting element, and the dose setting element and the adjusting element are coupled with one another by a positive fit so that they do not release from one another, even though a rotating movement can no longer be transmitted. In the event of a subsequent adjusting movement or an attempt to increase the set dose, therefore, the adjusting mechanism or the injection device can not be damaged. [0012] In some embodiments, the coupling between the dose setting element and the adjusting element may be achieved on the basis of an elastic material in the region of the coupling to establish a positive connection between the dose setting element and adjusting element. The positive connection still permits a relative movement between the dose setting element and the adjusting element which lies in a direction that does not correspond to the setting direction. If the setting direction is a direction of rotation, in other words is in a circumferential direction or motion, the coupling of the dose setting element with the adjusting element may be designed so that the adjusting element can be pushed in a direction that is different from the setting direction, in other words in an axial direction of the dose setting element or adjusting element, along an axis constituting a mid-axis of the rotation or setting movement. To this end, a surface may be provided on the dose setting element and/or adjusting element which extends at an angle by reference to the setting direction or axial direction of the dose setting element or adjusting element. The surface may be designed as a conically tapering element or annular cut-out of a cone surface. If an elastic material is used in the region of the coupling or contact surface between the dose setting element and the adjusting element, this will permit a relative movement due to a deformation of the elastic material which, in the absence of the external force which led to this relative movement, will result in an automatic backward or reverse movement of the adjusting element on or in the dose setting element. [0013] In one embodiment, an annular snapper bead or raised area may be provided on one of the elements which engages in a snapper groove of the other element. For example, a snapper bead may be on a cylindrically shaped projection of or associated with the dose setting element, which locates in a snapper groove extending circumferentially around the internal face of the dose setting element. This being the case, the snapper bead and/or the snapper groove may have a conical region. [0014] In some preferred embodiments, at least one and possibly several locking catch and/or co-operating catch elements may be provided in the circumferentially extending direction on the contact surface or contact region between the dose setting element and the adjusting element. The contact region between the dose setting element and the adjusting element on which these elements may be disposed may be a top region or end region of the dose setting element which comes into contact with a button or the disc-shaped region of the adjusting element. The locking or catch elements and co-operating elements have a mutually corresponding geometry. For example, triangular projecting catch cams may be provided on one element, which are able to engage in corresponding triangular recesses on the other element and which can be disengaged by a movement of the adjusting element out of the dose setting element while the dose setting element is being held and the adjusting element continues to be operated or rotated to enable the adjusting element to rotate relative to the dose setting element. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1A is a plan view of an embodiment of an injection device in accordance with the present invention in one operational position; [0016] FIG. 1B is a sectional view taken along line A-A of FIG. 1A ; [0017] FIG. 2A shows the injection device illustrated in FIG. 1A in a charged position with the adjusting and dose setting elements rotated outwardly; [0018] FIG. 2B is a sectional view along line B-B of FIG. 2A ; [0019] FIG. 3 is a sectional view along line C-C of FIG. 2A ; [0020] FIGS. 4A , B and C show a perspective view, side view and a sectional view of the dose setting element; [0021] FIGS. 5A , B and C show a perspective view, a plan view and a side view of the adjusting element; [0022] FIG. 6 is a perspective view of a portion of one embodiment of an injection device in accordance with the present invention; and [0023] FIG. 7 is an exploded perspective, including details drawn thereform, showing an embodiment of a dose selection ring with four snapper arms able to move inwardly and outwardly, each of which has catch elements pointing radially inwardly and outwardly. DETAILED DESCRIPTION [0024] With regard to fastening, mounting, attaching or connecting components of the present invention, unless specifically described as otherwise, conventional mechanical fasteners and methods may be used. Other appropriate fastening or attachment methods include adhesives, welding and soldering, the latter particularly with regard to the electrical system of the invention, if any. In embodiments with electrical features or components, suitable electrical components and circuitry, wires, wireless components, chips, boards, microprocessors, inputs, outputs, displays, control components, etc. may be used. Generally, unless otherwise indicated, the materials for making the invention and/or its components may be selected from appropriate materials such as metal, metallic alloys, ceramics, plastics, etc. [0025] FIG. 1B shows a view of the injection device 3 in cross-section along line A-A indicated in FIG. 1A , in which the dose setting sleeve 1 serving as the dose setting element, which is coupled with the dose setting ring 2 fitted on it or in it so that it can not rotate, is pushed in. The injection device 3 is therefore in an initial position. [0026] For details of the structure and the way in which a dose setting mechanism and an injection device or pen with such a dose setting mechanism inserted in it operates, reference may be made to patent specification DE 10 2005 044 096 A1, which is included in the teaching of the present application by way of reference. [0027] If the dose setting sleeve 1 , which has a thread on its external face engaging in an internal thread 3 d of the injection device 3 or a part (guiding sleeve) fixedly joined to the housing, is screwed out by a rotating movement of the dose setting ring 2 coupled with the dose setting sleeve 1 , the injection device 3 is in a charged position as illustrated in FIG. 2A . [0028] As may be seen from the view in cross-section illustrated in FIG. 2B , the dose selection ring 4 has a display on its external face with numbers applied to it, so that the size of a set dose can be read through a viewing window 3 a provided in the housing of the injection device 3 . [0029] The dose selection ring 4 can be rotated relative to the injection device 3 or housing of the injection device 3 so that the stop 4 a of the dose setting ring 4 pointing radially inwardly is turned as a function of the rotating movement of the dose selection ring 4 to fix the maximum dose based on the position of rotation of the stop 4 a . The adjusted position of rotation of the dose selection ring 4 may be locked by a lock mechanism when the dose setting sleeve 1 is pulled out of the injection device by a small amount. [0030] Provided on the internal circumference of the housing extending in the axial direction are grooves along which the catch elements mounted on snapper or resilient arms of the dose selection ring 4 and pointing radially outwardly are able to move, thereby generating a clicking noise. [0031] As may be seen from FIG. 3 , the dose setting sleeve 1 is mounted or positioned inside the dose selection ring 4 . During the adjusting operation, the dose setting sleeve 1 is moved backward or rearwardly in the axial direction and moved or rotated out of the injection device. [0032] FIG. 6 is a perspective view of an embodiment of an injection device in accordance with the present invention, and FIG. 7 is an exploded perspective view, including a view of a middle and/or front region of the dose setting sleeve 1 . A circumferentially extending groove 1 f is provided in which the catch elements of the dose selection ring 4 pointing radially inwardly lie in the position illustrated in FIG. 1 . The resilient arms of the dose selection ring 4 are therefore able to flex radially inwardly at a transition from one axially extending groove of the housing to the next one, which is what enables the rotating movement of the dose selection ring 4 while simultaneously generating clicking noises. [0033] When, having primed a dose set by the dose selection ring 4 , the dose setting sleeve 1 is pulled out of the injection device and hence out of the dose selection ring, the radially extending groove 1 f of the dose setting sleeve 1 no longer lies in the region of the snapper arms of the dose selection ring 4 and the catch elements pointing radially outwardly are therefore no longer able to flex inwardly and couple the dose selection ring with the injection device to prevent it from rotating due to an engagement in the radially extending inner grooves of the injection device. [0034] By the dose selection ring 4 , the dose to be dispensed can be set inside the injection device 3 and when the dose setting sleeve 1 is fitted, a cam or a lug 1 c of the dose setting sleeve 1 projecting radially outwardly is turned onto the stop 4 a of the dose selection ring 4 projecting radially inwardly, as may be seen from FIG. 3 . If the dose setting sleeve 1 were rotated further, the mutually abutting stops or lugs 1 c and 4 a of the dose setting sleeve 1 and the dose selection ring 4 respectively could break or be deformed in the fully attached state. [0035] However, since the user does not operate the dose setting sleeve 1 directly and instead operates the dose setting ring 2 coupled with the dose setting sleeve 1 , which can be snap-fitted onto the dose setting sleeve 1 for example, the stops 1 c and 4 a are prevented from breaking or deforming. [0036] During a setting operation, the dose setting ring 2 is operated by a user, for example held. The ring has a snapper bead 2 a extending around its circumference which snaps into a snapper groove 1 a on the internal face of the dose setting sleeve 1 . Projecting in the axial direction of the injection device or pen 3 , triangular catch cams 2 c are provided extending circumferentially around the dose setting ring 2 , which latch in corresponding catch grooves 1 d in the proximal external circumferential face of the dose setting sleeve 1 . When the dose setting ring 2 is rotated further, even though the dose setting sleeve 1 lies with its cam 1 c against the inner cam 4 a of the dose selection ring 4 , the catch cams 2 c of the dose setting ring 2 are released from the catch grooves 1 d of the dose setting sleeve 1 and rotated by one position. As this happens, the ramp or a surface on the snapper bead 2 a of the dose setting sleeve 2 causes a biasing movement of the dose setting ring 2 into the dose setting sleeve 1 so that, following a further movement of the triangular catch cams 2 c of the dose setting ring 2 , the catch cams 2 c are able to latch in the catch grooves 1 d of the dose setting sleeve 1 again in the next position. [0037] This results in an overstrain lock, i.e. the dose setting sleeve 1 can no longer be over-rotated relative to the dose selection ring 2 and the stops 1 c and 4 a can no longer be deformed or broken. [0038] It is of advantage if the biasing action of the dose setting ring 2 is set so that the triangular catch cams 2 c of the dose setting ring 2 can be more easily released from the catch grooves 1 d of the dose setting sleeve 1 , i.e. with a lighter force, than a force which would be necessary to deform or break the stops 1 c and 4 a of the dose setting sleeve 1 and the dose selection ring 4 . [0039] FIG. 4 a shows a perspective view of the dose setting sleeve 1 with the snapper groove 1 a in the internal face extending in the circumferential direction, in which the snapper bead 2 a of the dose setting ring 2 engages. Extending around the circumference of its axial boundary surface, the dose setting sleeve 1 has several triangular recesses 1 d pointing in the axial direction, in which the catch cams 2 c of the dose setting ring 2 illustrated in FIG. 5A are able to engage. [0040] As may be seen from FIG. 5C , the snapper bead 2 a has an oblique or conical region 2 c , which is able to lie against the conical region 1 e of the snapper groove 1 a illustrated in FIG. 4A . The snapper bead 2 a and/or the dose setting sleeve 1 in the region of the snapper groove 1 a are made from an elastic material to permit an outward movement of the dose setting ring 2 . The movement is sufficient so that the anti-rotation coupling established by the catch cams 2 c and the catch grooves 1 d can be at least temporarily released. [0041] Embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed. The embodiments were chosen and described to provide the best illustration of the principles of the invention and the practical application thereof, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.

A setting mechanism for setting or selecting a quantity of a substance to be dispensed from an injection device, the mechanism including a dose setting element and an adjusting element which can be operated by a user, wherein the adjusting element is operably coupled to the dose setting element and an overstrain lock is provided between the dose setting element and the adjusting element.

GOVERNMENT RIGHTS The United States Government has the rights in this invention pursuant to Contract No. DE-AC03-76SF00098 between the United States Department of Energy and the University of California. BACKGROUND OF THE INVENTION The invention relates generally to LED lighting systems and more particularly to security lighting systems with LEDs. As LED technology progresses, LEDs will be used for many lighting applications. White light LEDs are still in their infancy and questions regarding their color rendering and lifetime need to be resolved before wide scale commercial adoption. Colored LEDs, however, are a proven technology, and as outputs continue to increase, colored lighting opportunities will be further enabled. Exit signs and traffic signals are examples of colored lighting markets that have seen widespread commercial success by LEDs and soon may be dominated if not monopolized by LEDs. Security lighting, particularly in outdoor environments, is a lighting application of great interest. LEDs are not the ideal choice because white light is generally needed and only colored LEDs are generally available. Incandescent lights can be used but consume much more energy. Thus a security lighting system with the advantageous features of both LEDs and incandescent lamps without their limitations is highly desired. SUMMARY OF THE INVENTION The invention is a dual Led and incandescent security lighting system that uses a hybrid approach to LED illumination. It combines an ambient LED illuminator with a standard incandescent lamp on a motion control sensor. The LED portion will activate with the onset of darkness (daylight control) and typically remain on during the course of the night (“always on”). The LED illumination, typically amber, is sufficient to provide low to moderate level lighting coverage to the wall and ground area adjacent to and under the fixture. The incandescent lamp is integrated with a motion control circuit and sensor. When movement in the field of view is detected (after darkness), the incandescent lamp is switched-on, providing an increased level of illumination to the area. Instead of an “always on” LED illuminator, the LEDs may also be switched off when the incandescent lamp is switched on. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a dual LED/incandescent security lighting system of the invention. FIG. 2 shows a variation of the dual LED/incandescent security lighting system of FIG. 1 . FIGS. 3-5 show other embodiments of the dual LED/incandescent security lighting system of the invention. FIG. 6 shows another embodiment of the dual LED/incandescent security lighting system of the invention with a separate LED drop unit. FIG. 7 is a block diagram of a control system for the dual LED/incandescent lighting system of the invention. DETAILED DESCRIPTION OF THE INVENTION The invention may be Implemented in a number of different embodiments. The following are illustrative but not limiting. As shown in FIG. 1 , hybrid LED/incandescent light fixture 10 combines an LED array 12 and an incandescent lamp (A-lamp) 14 in a single housing 16 . The incandescent source or lamp 14 screws into a standard socket 15 and is held in a horizontal position. The LED array 12 is placed facing down from the top 22 of the housing 16 , near the front edge, and extending forward substantially beyond A-lamp 14 . The top 22 of housing 16 not only supports the LED array 12 but also provides a heatsink for the LED array 12 and provides a physical shield to prevent light from either the LED array 12 or A-lamp 14 from traveling upwards into the night sky. Housing 16 is attached to a wall mount/power supply unit 17 , which is attached to wall 20 and electrically connected to a power source, typically standard electrical wiring from a power line. Socket 15 and LED array 12 are electrically connected to unit 17 for power. A motion detector 18 is mounted below housing 16 (or elsewhere) and is also electrically connected to unit 17 for power. The control system for fixture 10 is contained in unit 17 . Also forming a part of housing 16 , extending down from top 22 and surrounding or enclosing LED array 12 and A-lamp 14 , is a diffuser or lens 19 , which typically is a diffuser but also may be a clear lens. The front part 23 of diffuser/lens 19 is typically tapered inwardly from top to bottom. LED array 12 includes a plurality of LEDs 21 . The LEDs are typically amber or yellow in color, but may be other colors or even white. A-lamp 14 may be replaced by a halogen lamp, or compact fluorescent lamp, or other lamp. Diffuser/lens 19 allows the light from LED array 12 and from A-lamp 14 to pass to the local environment, generally illuminating the area around fixture 10 . Diffuser/lens 19 is typically formed of flat or roughened panes of clear or translucent glass or plastic. In operation, a sensor detects the occurrence of darkness and turns on the LED array 12 . After that, whenever motion sensor 18 detects motion in the vicinity of fixture 10 , the A-lamp 14 is switched on, and remains on for a preset time. LED array 12 may remain on when A-lamp 14 is on, or it may shut off to conserve energy and to prevent color shadows. The construction of the fixture 10 is such that the light output is directed down, mitigating light pollution issues. This fixture is intended as a replacement fixture: it either replaces a porch light in a retrofit application, or is used in new construction as an alternative to another porch light. FIG. 2 shows a dual LED/incandescent fixture which is very similar to fixture 10 of FIG. 1 except for the position of LED array 12 relative to A-lamp 14 . In fixture 11 , LED array 12 is recessed into housing 16 so that it is over A-lamp 14 . Most of the light from LED array 12 , then passes through A-lamp 14 , which acts as a diffuser, so lens 19 is then typically clear. The remaining components are the same as in FIG. 1 . FIG. 3 shows an alternate embodiment of the invention with the incandescent lamp 14 in a lamp down orientation. The LEDs 21 are mounted in a ring around the base of the A-lamp 14 . Dual LED/incandescent fixture 25 incorporates many of the same components as fixtures 10 , 11 but in a different arrangement. Fixture 25 hangs down from a wall or overhang 20 . Power supply/wall mount unit 17 is attached under wall 20 and contains the electrical connections to the power source and the control system. Socket 15 , into which A-lamp 14 screws, is mounted under and electrically connected to unit 17 . LEDs 21 are mounted on and electrically connected to unit 17 , forming an array 12 . Motion sensor 18 is integrated into unit 17 . Diffuser/lens 19 extends down from unit 17 and encloses and surrounds LEDs 21 and A-lamp 14 . FIG. 4 shows another embodiment of the invention that is intended as a screw-in retrofit. In the dual fixture 30 , the LEDs 21 and associated electronics are integrated into a screw-in A-lamp type base 32 . This base 32 then receives a standard A-lamp, 14 in A-lamp socket 33 . Base 32 screws into a standard socket in a wall which is connected to electrical power, e.g. in a standard porch light fixture. A-lamp 14 and LEDs 21 are thereby electrically connected to a power source. A light guide or cover lens 34 that attaches to the base 32 may be necessary to control the light distribution, as well as mitigate direct glare from the LEDs 21 . LEDs 21 are arranged in an array 12 around the edge of base 32 and are aligned with an input section 35 of light guide/lens 34 . In an alternate embodiment shown in FIG. 5 , dual LED/incandescent system 40 separates the LED lighting component from the incandescent lighting fixture. There are separate side-by-side fixtures, LED fixture 42 and A-lamp fixture 44 . A-lamp fixture 44 is essentially a standard porch light fixture. LED fixture 42 attaches to wall 20 , e.g. at an outdoor junction box. An array 12 of LEDs 21 is mounted in LED fixture 42 , facing downward, and enclosed or surrounded by a diffuser/lens 43 . LED fixture 42 is built to receive an A-lamp fixture 44 on its front surface, as shown by arrows 45 . A-lamp fixture 44 includes a downward facing incandescent lamp 14 , which screws into electrical socket 15 . A diffuser/lens 46 encloses and surrounds A-lamp 14 . The electronics, including the motion sensor, are typically mounted in LED fixture 42 . Another embodiment of the invention, shown in FIG. 6 , also separates the LED light component from the incandescent fixture. But instead of having the LED, motion sensor, and control electronics in the same box, dual LED/incandescent system 50 has an LED “drop”unit 52 under the main incandescent unit control box 54 . Control box 54 is configured to mount onto a wall. The front surface is configured to receive a standard “porch light” type fixture 55 (similar to fixture 44 in FIG. 5 ). Control box 54 typically contains the LED driver circuit, the motion control circuit, and the daylight sensing circuit. Drop unit 52 contains the LEDs and the motion-sensor, which operates through motion sensor window 53 . Drop unit 52 is connected to main unit 54 by drop arm 56 . The drop arm could have an adjustable length, and could be set by the end user according to the particular installation environment. This “drop” feature accomplishes several things. It lowers the LED emitters, reducing the problem of direct glare from the LEDs and increasing the illuminance on the ground below the fixture. It allows the motion sensor unit, also incorporated into the drop unit, to clear the porch light fixture and see the appropriate field of view for proper motion sensing operation. It also separates the heat generating LEDs from the rest of the unit, keeping this heat away from the control electronics. FIG. 7 illustrates a control system 60 for the dual LED/incandescent lighting system of the invention. A detector 61 detects the onset of darkness and actuates a switch 62 which turns on LED array 63 . During darkness, when motion sensor 64 detects motion, its output signal is combined with the output signal from detector 61 , e.g. in AND gate 65 , to actuate a second switch 66 to turn on A-lamp 67 . Once A-lamp 67 is turned on, a timer 68 which is also actuated by switch 66 may be used to turn off A-lamp 67 after a preset and selectable period of time. Switch 66 , when turned on, may also turn off switch 62 to shut off the LED array 63 when A-lamp 67 is on. This type of hybrid approach to LED illumination has the following advantages and benefits. 1) The LED source (one or more LEDs in an array) consumes a relatively small amount of power compared to the incandescent source, yielding substantial energy savings without a loss in functionality. 2) The LED source provides ambient illumination to the area, eliminating the “all-or-nothing” effect of traditional motion sensor fixtures. 3) The LED source will have a very long lifetime, ensuring at least some illumination to the control area when the incandescent lamp fails. 4) With colored LED sources, the motion activated incandescent lamp will provide a color change when triggered, increasing the conspicuousness of the motion activation and increasing the security benefit of the trigger. 5) With colored LED sources, different nighttime aesthetics can be achieved. 6) The combination of the LED source(s) and the incandescent source yields the best dollars per lumen ratio for the target applications. The number of (expensive) LEDs is kept to a minimum while, at the same time, the incandescent lamp provides a high lumen output for good visibility when the application area is occupied. Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.

A dual LED and incandescent security lighting system uses a hybrid approach to LED illumination. It combines an ambient LED illuminator with a standard incandescent lamp on a motion control sensor. The LED illuminator will activate with the onset of darkness (daylight control) and typically remain on during the course of the night (“always on”). The LED illumination, typically amber, is sufficient to provide low to moderate level lighting coverage to the wall and ground area adjacent to and under the fixture. The incandescent lamp is integrated with a motion control circuit and sensor. When movement in the field of view is detected (after darkness), the incandescent lamp is switched on, providing an increased level of illumination to the area. Instead of an “always on” LED illuminator, the LEDs may also be switched off when the incandescent lamp is switched on.

CROSS-REFERENCE TO RELATED APPLICATIONS Background Relational database query processing has been optimized for a traditional processing model that assumes a set of tightly-coupled, very fast central processors and a very large (on the order of 100 Terabytes), but relatively slow disk system, which has sufficient capacity to store all of the needed tables. A virtualized memory, including terabytes of main memory, between the processor and the disk system helps avoid costly disk I/O operations. However, the fast central processors and large disk systems are expensive and consume large amounts of power (on the order of 10 kW). New lower cost and lower power processing models are available, partly because the cost per bit of main memory such as DRAM has dropped substantially. One such model is a cluster having a large number of processing units, each including a low-speed processor, modest amounts of main memory compared to the amount of storage in a disk system, and no persistent storage by which the main memory is virtually extended. In this model, a cluster may have as many as 1000 processing units. The large number of processing units in a cluster has very high aggregate computing power and memory, if each of the processing units can be properly utilized. This potentially high performance makes a cluster attractive for query processing, but the disk-based model poses problems when the query processing is moved to in-memory database processing. BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the embodiments and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: FIG. 1 depicts an example process for carrying out an embodiment; FIG. 2 depicts an example process for encoding a relation; FIG. 3 depicts an example process for selecting auxiliary structures; FIG. 4 depicts an example process for determining the cost and benefit of an auxiliary structure; FIG. 5 depicts an example process for performing run-time encoding during query processing; and FIG. 6 depicts an example system setting. DETAILED DESCRIPTION Overview An embodiment adapts the disk-based query processing to in-memory database query processing, which requires that the amount of memory and the compute and memory bandwidth used be minimized, while maintaining performance. To minimize memory and bandwidths, data structures on which the queries operate are adapted to the size of the memory. To maintain performance, an optimal set of auxiliary data structures is kept in memory. In an embodiment depicted in FIG. 1 , the system selects encodings in step 10 for columns in a relation to adapt the relation to the size of the memory. The cost of the encoding based on query operations in the query workload determines the encoding selections. In the embodiment, maintaining performance is accomplished by selecting auxiliary structures in step 12 based on the amount of memory and the benefit for each auxiliary structure. Actual encoding of the selected encodings proceeds in real time in step 14 while the system processes queries in memory. A system of locks assures that the real time encoding does not substantially interfere with the query processing. Detailed Description Candidate Encoding FIG. 2 depicts an example process for encoding a column in a relation. In step 202 , the computer system determines the candidate encodings for a given column C j . The computer system examines one or more candidate encodings for each column based on data stored in the column. The computer system considers the average length of the data in the column in bytes, the number of distinct data values in the column, and an average run length of data values in the column to select among possible encodings, such as dictionary encodings, run-length encodings, native integer encodings, scaled-decimal encodings, frame of reference encodings, string compression encodings, and bit maps. Each type of encoding is suitable for a particular type of data. For example, run length encoding is suited to columns that have long lengths of repetitious data, because such encoding can make a substantial reduction in the amount of memory the column uses. Frame of reference encodings are especially suited to numeric columns. LZ (Lempel-Ziv) compression is especially suited for string columns. Native integer encodings are best for arithmetic and numerical aggregates, and sorting operations. Native fixed length integer encodings are well-suited to cases in which filters are involved. Bit maps are especially well-suited to low cardinality columns. Dictionary encodings are a good choice when grouping operations are present. Cost The computer system determines the cost of each candidate encoding E k in step 204 , after determining candidate encodings for a given column C j , in step 202 . In an embodiment, the cost reflects a given representative query workload, where the workload is characterized by types of operations, such as projections, groupings, and sorting operations, described in more detail below. In particular, for each given column C j , statistics are gathered for each type of operation O i and for all queries (∀Q m ) in the workload, where the statistics include the average number of rows processed R[C j , O i ], the fraction of query processing time (or estimated cost) taken by the operation on the column F[C j , O i ], and the average selectivity for filters on the column S[C j , O i ]. The cost is computed from these statistics according to the following function: (a) if the fraction of query processing time F [C j , O i ] is small or zero (meaning that the column is not used in the queries), then the cost is just the amount of memory used; and (b) if the fraction of query processing time F[C j , O i ] is not small, then compute the cost according to a particular cost formula for each candidate encoding E k . In one embodiment, the cost formula is: Σ o Cost[C j ,O i ]=Σ o (Cost basic [C j ,O i ]·AveLength E i ·R[C j ,O i ]·F[C j ,O i ]),  (1) where the cost is computed over all operations, where Cost basic [C j , O i ] is the basic cost of the query determined by running pre-designed pieces of code that approximate each query operation, AveLength E k is the average length per row of the column's value for a particular encoding E k , and where R[C j , O i ] and F[C j , O i ] are the statistics stated above. Thus, for a given average number of rows R[C j , O i ] and fraction F[C j , O i ], the cost is higher if the AveLength E i is larger. The system selects the encoding having the minimum memory or minimum cost, after the cost is determined. Types of Operations For Workload Statistics As mentioned above, the cost of each candidate encoding in one embodiment is based on operations found in a representative query workload. The types of operations considered in such a workload include at least filter, standard operators and functions, projection, grouping, and sorting operations. Filter operations includes relational comparison operator such as “=”, “<”, “>” on the value of the column or the value of applying a function/operator on the column. Standard operators and functions include arithmetic operators such as “+” and “−”, string operations such as concatenation, “upper”, “substr”, as well as aggregation functions like “sum.” Projection operations involve decoding the data representation (decompressing) to get the value in the original representation for that data type, e.g., text for strings. Grouping operations involve gathering all rows that have the same value for the group-by-column(s). Such operations typically involve the calculation of a hash function and probing of a hash table. Sorting operations include sorting a relation or sub-relations by a set of columns. Auxiliary Structures Many query processes benefit from auxiliary structures, which speed up the processing of the query. Such structures include B-Trees, sorted representations, bit maps, bloom filters, and indexes. B-Trees benefit columns that are frequently filtered with highly selective range predicates. The benefit of a B-Tree is even higher if the column is frequently the subject of a sort operation. Sorted representations are arrays in which entries are (column-value, row-id) pairs sorted by column value. Columns that are frequently the subject of a sort operation benefit from sorted representations. Bitmap structures are very useful for low-cardinality columns that are frequently filtered using equality conditions. The column has one bitmap for each distinct value and each bit map has as many bits are there are rows. For each row, the corresponding bit indicates whether the column's value in that row is the value of that the bitmap represents. Bloom filter structures, in which hash functions map a set element to a bit array, are useful for filter operations having equality predicates. A bloom filter that represents a summary of the data values in a chunk can be used to skip a chunk if the given value is not present in the chunk (as indicated by a bit not present in the bloom filter). Given a certain quantity of available memory, it is desirable to choose a set of auxiliary structures that provides the most benefit at the least cost to in-memory database query operations, specifically, operations on columns. Therefore, the system chooses in step 302 of FIG. 3 columns that can benefit from auxiliary structures based on the types of operations on the column. For example, if a column has highly selective filter operations or a high frequency of sort operations, then a B-Tree index structure may provide a performance boost. Selecting a column that can benefit from an auxiliary structure is based on tunable threshold values to maintain control over the number of candidate auxiliary structures to be considered for the column. For a given column and for each candidate structure in a set of auxiliary structures, an embodiment of the system determines, in step 304 , a measure of the benefit B i that the candidate structure can provide to the given column and the cost, which is the amount of memory M i that the candidate auxiliary structure uses. The embodiment then decides, in step 306 , on the subset of auxiliary structures that provide the most benefit for the available memory. To help determine the cost of an auxiliary structure, available memory is divided into a number L of equal-sized chunks. Thus, the amount M i of memory needed for an auxiliary structure has a range of 1 to L chunks, meaning the structure can occupy one chunk or the entire amount of available memory. The actual number of chunks needed for an auxiliary structure depends on the length of the column as well as the type of auxiliary structure. The benefit B i of an auxiliary structure i is a sum, over all applicable operations, of a product of an estimate of the improvement per row that the auxiliary structure provides for each applicable operation, the number of rows for the operation on that column R[C j , O i ], and the query cost fraction F[C j , O i ]. Thus, the benefit of a particular structure is B i =Σ o (improvement·R[C j ,O i ]·F[C j ,O i ]).  (2) Given a set of benefits B={B 1 . . . B N } for each candidate auxiliary structure and a set of costs M={M 1 . . . M N }, in terms of memory needed, for each candidate structure, where N is the total number of candidate structures, the system computes the optimal set. Specifically, the system computes a function ƒ (B, M) whose output is a pair of sets T and S, where T includes benefit data for every combination of N auxiliary structures and L memory sizes, and S includes entries that identify the particular auxiliary structures that provide the benefit for the corresponding entry in T. The final item in T is the optimal benefit and the final item in S indicates the structures that provide the optimal benefit. In one embodiment, the function ƒ (M, B) is the one depicted in FIG. 4 . In that function, the sets S(L, N), T(L, N) are implemented, respectively, as two dimensional arrays S(i, j), T(i, j) where i=[0 . . . L] and j=[0 . . . N]. In step 402 , the T and S arrays are initialized by setting ∀j.T (0,j)=0 and ∀i.T (i, 0)=0 and by clearing bits ∀j.S(0,j) and ∀i.S(i, 0). Two loops, one with j=1 . . . N and i=1 . . . L are initialized in steps 404 , 406 . The outer loop, j, steps through the number of possible denormalizations and the inner loop i, steps though the sizes of memory up to the maximum size L. Thus, the outer loop selects a denormalization and the inner loop examines the cost and benefit of the selected denormalization for each memory size. In step 408 , the function performs a test on M[j] and on T(i−M[j],j−1). If M[j]>i  (3) then the number of memory chunks for the jth denormalization is greater than the current size of the memory. If T ( i,j− 1)> T ( −M[j],j− 1)+ B[j]   (4) then the benefit of the previous denormalization is greater than the current one. In either case there is no added benefit, so the function carries forward the current benefit and previous set of denormalizations by copying the previous benefit to the current benefit in step 410 and the previous set of denormalizations providing the previous benefit to the current set in step 412 , as depicted below. T ( i,j )= T ( i,j− 1)  (5) S ( i,j )= S ( i,j− 1)  (6) Otherwise, in steps 414 and 415 , the function updates T ( i,j )= T ( −M[j],j− 1)+ B[j]   (7) S ( i,j )={Set the jth bit in S ( i−M[j],j− 1)},  (8) the current benefit amount T (i,j) and the current set S(i,j) of denormalizations providing that benefit. When the function completes, the array entry T(L, N) has the maximum benefit for the given memory size L and the array entry S has the set of denormalizations providing that benefit. As an example, suppose that a particular auxiliary structure at j=1 has a benefit of 5 and uses 7 chunks of memory. When the cost is too large (7>[1 . . . 6]), the previous column to be copied to the current column. When the cost is not too large (7≯[ 8 . . . L]), then T is updated with the benefit 5, and S has its bitmap updated to indicate that structure j provided the benefit. Each succeeding row in T is updated with the benefit 5 and each bit map is updated in S, until the final row in the column is reached. Runtime Encoding The system encodes, in real-time, each candidate column C j with the encoding selected for the column. This means that while the system is processing in-coming queries it is also encoding columns in relations that may be the subject of an in-coming query. To get the encoding process and the query processing to cooperate with each other, memory is partitioned into a set of chunks, query processing operates serially over the chunks, and each type of processing obtains a lock to operate on one of the chunks, as depicted in FIG. 5 . When query processing reaches a particular chunk in step 504 , it obtains a shared lock on the chunk in step 506 and processes the queries in the chunk in step 508 , after which in step 510 it releases the lock. When the encoding process reaches on a chunk as in step 516 , it obtains an exclusive lock on the chunk in step 518 . If query processing has obtained a shared lock on a particular chunk, then if the encoding process reaches the same chunk as in step 516 , it must wait for the shared lock to be released, as in step 510 . If the encoding process has obtained an exclusive lock on a particular chunk as in step 518 , then if the query processing reaches the same chunk as in step 504 , it must wait for the exclusive lock to be released as in step 522 . Though the arrangement may limit performance of the query processing, it allows the encoding to proceed so that gains from the encoding can be realized. System Setting According to one embodiment, the techniques described herein are implemented by one or more special-purpose computing devices. The special-purpose computing devices may be hard-wired to perform the techniques, or may include digital electronic devices such as one or more application-specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs) that are persistently programmed to perform the techniques, or may include one or more general purpose hardware processors programmed to perform the techniques pursuant to program instructions in firmware, memory, other storage, or a combination. Such special-purpose computing devices may also combine custom hard-wired logic, ASICs, or FPGAs with custom programming to accomplish the techniques. The special-purpose computing devices may be desktop computer systems, portable computer systems, handheld devices, networking devices or any other device that incorporates hard-wired and/or program logic to implement the techniques. For example, FIG. 6 is a block diagram that depicts a computer system 600 upon which an embodiment may be implemented. Computer system 600 includes a bus 602 or other communication mechanism for communicating information, and a hardware processor 604 coupled with bus 2902 for processing information. Hardware processor 604 may be, for example, a general-purpose microprocessor. Computer system 600 also includes a main memory 606 , such as a random access memory (RAM) or other dynamic storage device, coupled to bus 602 for storing information and instructions to be executed by processor 604 . Main memory 606 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 604 . Such instructions, when stored in non-transitory storage media accessible to processor 604 , convert computer system 600 into a special-purpose machine that is customized to perform the operations specified in the instructions. Computer system 600 further includes a read only memory (ROM) 608 or other static storage device coupled to bus 602 for storing static information and instructions for processor 604 . A storage device 610 , such as a magnetic disk or optical disk, is provided and coupled to bus 2902 for storing information and instructions. Computer system 600 may be coupled via bus 602 to a display 612 , such as a cathode ray tube (CRT), for displaying information to a computer user. An input device 614 , including alphanumeric and other keys, is coupled to bus 602 for communicating information and command selections to processor 604 . Another type of user input device is cursor control 616 , such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 604 and for controlling cursor movement on display 612 . This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane. Computer system 600 may implement the techniques described herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware and/or program logic which in combination with the computer system causes or programs computer system 600 to be a special-purpose machine. According to one embodiment, the techniques herein are performed by computer system 600 in response to processor 604 executing one or more sequences of one or more instructions contained in main memory 606 . Such instructions may be read into main memory 606 from another storage medium, such as storage device 610 . Execution of the sequences of instructions contained in main memory 606 causes processor 604 to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. The term “storage media” as used herein refers to any non-transitory media that store data and/or instructions that cause a machine to operation in a specific fashion. Such storage media may comprise non-volatile media and/or volatile media. Non-volatile media includes, for example, optical or magnetic disks, such as storage device 610 . Volatile media includes dynamic memory, such as main memory 606 . Common forms of storage media include, for example, a floppy disk, a flexible disk, hard disk, solid state drive, magnetic tape, or any other magnetic data storage medium, a CD-ROM, any other optical data storage medium, any physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, NVRAM, any other memory chip or cartridge. Storage media is distinct from but may be used in conjunction with transmission media. Transmission media participates in transferring information between storage media. For example, transmission media includes coaxial cables, copper wire and fiber optics, including the wires that comprise bus 602 . Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications. Various forms of media may be involved in carrying one or more sequences of one or more instructions to processor 604 for execution. For example, the instructions may initially be carried on a magnetic disk or solid-state drive of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system 600 can receive the data on the telephone line and use an infra-red transmitter to convert the data to an infra-red signal. An infra-red detector can receive the data carried in the infra-red signal and appropriate circuitry can place the data on bus 602 . Bus 602 carries the data to main memory 606 , from which processor 604 retrieves and executes the instructions. The instructions received by main memory 606 may optionally be stored on storage device 610 either before or after execution by processor 604 . Computer system 600 also includes a communication interface 618 coupled to bus 602 . Communication interface 618 provides a two-way data communication coupling to a network link 620 that is connected to a local network 622 . For example, communication interface 618 may be an integrated services digital network (ISDN) card, cable modem, satellite modem, or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 618 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface 618 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information. Network link 620 typically provides data communication through one or more networks to other data devices. For example, network link 620 may provide a connection through local network 622 to a host computer 624 or to data equipment operated by an Internet Service Provider (ISP) 626 . ISP 626 in turn provides data communication services through the world wide packet data communication network now commonly referred to as the “Internet” 628 . Local network 622 and Internet 628 both use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on network link 620 and through communication interface 618 , which carry the digital data to and from computer system 600 , are example forms of transmission media. Computer system 600 can send messages and receive data, including program code, through the network(s), network link 620 and communication interface 618 . In the Internet example, a server 630 might transmit a requested code for an application program through Internet 628 , ISP 626 , local network 622 and communication interface 618 . The received code may be executed by processor 604 as it is received, and/or stored in storage device 610 , or other non-volatile storage for later execution. In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the embodiments, and what is intended by the applicants to be the scope of embodiments, is the literal and equivalent scope of the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction.

A method for providing optimized data representation of relations for in-memory database query processing is disclosed. The method seeks to optimize the use of the available memory by encoding relations on which the in-memory database query processing is performed and by employing auxiliary structures to maintain performance. Relations are encoded based on data patterns in one or more attribute-columns of the relation and the encoding that is selected is suited to a particular type of data in the column. Members of a set of auxiliary structures are selected based on the benefit the structure can provide and the cost of the structure in terms of the amount of memory used. Encoding of the relations is performed in real-time while query processing occurs, using locks to eliminate conflicts between the query processing and encoding.

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2008-148737, which was filed on Jun. 6, 2008, the entire disclosure of which is hereby incorporated by reference. TECHNICAL FIELD [0002] The present invention relates to an underwater detection device that transmits a frequency-modulated transmission pulse signal, receives a signal reflected from a target object, and carries out a pulse compression process of the received signal, and more particularly, to an underwater detection device having a configuration to remove range side lobes produced in association with the pulse compression. BACKGROUND [0003] For fishfinders that is one type of underwater detection devices, increasing in detection distance is demanded to detect a shoal of fish at a deeper location. In order to increase the detection distance, generally, a transmission pulse length is simply lengthened. However, if the transmission pulse length is lengthened, an echo reflected from a target object will also be longer, and the axial resolving power will be reduced. Thus, a method of increasing the axial resolving power may be adopted in which a transmission pulse is frequency-modulated, and a received echo signal and a replica waveform of the transmitted signal is correlation-processed to perform a pulse compression of the received signal. An underwater detection device that performs such a pulse compression process is disclosed in JP2005-249398 (A). [0004] However, in the underwater detection device that performs the pulse compression process, as shown in FIG. 10 , false images referred to as “range side lobes” appear at positions before and after a main lobe, that shows a position of a detection target object, of a pulse-compressed signal. [0005] When the range side lobes appear, especially due to a seabed, the false images may be mistakenly viewed by an operator as a target object, such as a school of small fish. In addition, an image of a shoal of fish located near the seabed may be difficult to view and a seabed depth may mistakenly be determined. SUMMARY [0006] The present invention provides an underwater detection device that suppresses range side lobes due to a seabed to clearly display a detection image of near the seabed. [0007] According to an aspect of the invention, an underwater detection device includes a transceiver module for transmitting underwater an ultrasonic pulse signal that is frequency-modulated and receiving an echo signal corresponding to the transmitted signal, a pulse compression module for pulse-compressing the signal received by the transceiver module and outputting a signal pulse-compressed, a suppression range determining module for determining a suppression range where a range side lobe suppression process is performed for the pulse-compressed signal, an echo determining module for determining whether the data of the pulse-compressed signal at each depth corresponding to a range side lobe, a suppression value determining module for determining a suppression value for the data of the pulse-compressed signal at each depth, a suppression conducting module for performing a calculation to suppress the range side lobe based on the suppression value for the data determined to be data of the pulse-compressed signal corresponding to the range side lobe by the echo determining module among a plurality of data of the pulse-compressed signals that fall into the suppression range, and a display processing module for generating a signal for display based on the signal outputted from the suppression conducting module to display a generated signal as detected information. [0008] According to the aspect of the present invention, the underwater detection device can be realized in which the range side lobes due to the seabed is suppressed and the detection image of near the seabed is clearly displayed. [0009] The suppression range determining module may include a forward peak-hold module that selects, for each depth, data with the largest signal strength among data of the pulse-compressed signals falling into a depth range from the depth concerned to a depth deeper by a predetermined depth, and outputs the selected data as a forward peak-hold value of the depth concerned, and a rearward peak-hold module that selects, for each depth, data with the largest signal strength among data of the pulse-compressed signals falling into a depth range from the depth concerned to a depth shallower by the predetermined depth, and outputs the selected data as a rearward peak-hold value of the depth concerned. The suppression range determining module may determine a depth range where the forward peak-hold value is greater than a first predetermined threshold and the rearward peak-hold value is less than the first predetermined threshold, as the suppression range. [0010] When a value obtained by dividing the forward peak-hold value by the data of the pulse-compressed signal at the same depth is greater than a second predetermined threshold, the echo determining module may determine the data concerned to be data corresponding to a range side lobe. [0011] The suppression value determining module may determine the suppression value based on a suppression offset value defined with a first average value derived based on data of the pulse-compressed signal within the suppression range and a second average value derived based on data of the pulse-compressed signal outside the suppression range but within a predetermined depth range, and a suppression function that is a function simulating a shape of a range side lobe. [0012] According to another aspect of the invention, a ship may be equipped with any one of the underwater detection devices described above. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which the like reference numerals indicate like elements and in which: [0014] FIG. 1 is a block diagram of a fishfinder according to an embodiments of the present invention; [0015] FIG. 2 is a block diagram showing a configuration example of a range side lobe suppression module; [0016] FIG. 3 is a block diagram showing a configuration example of a suppression range determining module; [0017] FIG. 4 is a block diagram showing a configuration example of an echo determining module; [0018] FIG. 5 is a block diagram showing a configuration example of a suppression value determining module; [0019] FIG. 6 is a waveform chart for illustrating a signal processing in the suppression range determining module; [0020] FIG. 7 is a waveform chart for illustrating a signal processing in the echo determining module; [0021] FIG. 8 is a waveform chart for illustrating a signal processing in the suppression value determining module; [0022] FIG. 9 is a waveform chart for illustrating a signal processing in a suppression conducting module; and [0023] FIG. 10 is a waveform chart for illustrating range side lobes produced in association with a pulse compression. DETAILED DESCRIPTION [0024] An embodiment in which the present invention is applied to a fishfinder is explained referring to the appended drawings. [0025] FIG. 1 is a block diagram of the fishfinder according to this embodiment. As shown in FIG. 1 , a transducer 1 typically provided at the bottom of a ship is driven by an electric signal supplied from a transmission module 3 via a trap circuit 2 to transmit an ultrasonic pulse signal to underwater and receive an echo reflected and returned from an underwater target object. The transducer 1 then outputs the received signal to an amplifier 4 via the trap circuit 2 . [0026] The amplifier 4 amplifies the received signal, and the A/D converter 5 samples the amplified signal and converts it into a digital signal. A pulse compression module 6 performs a cross correlation process with the digital signal from the A/D converter 5 and a replica waveform of the transmission pulse signal, and then outputs the pulse-compressed signal. A detection module 7 detects the pulse-compressed signal. A range side lobe suppression module 8 performs a process to suppress range side lobes for the detected pulse-compressed signal as described below. A display processing module 9 generates a signal for display based on the pulse-compressed signal from the range side lobe suppression module 8 the range side lobes of which are suppressed, and then displays an underwater image on a display thereof. [0027] FIG. 2 shows a particular configuration example of the range side lobe suppression module 8 . Here, the detected pulse-compressed signal inputted into the range side lobe suppression module 8 is SIGin [n] (n=0 to (N−1)) and N is a data number obtained by one transmission and reception. [0028] In FIG. 2 , a suppression range determining module 10 determines a range where range side lobes of the pulse-compressed signal are suppressed. An echo determining module 11 determines whether data of the pulse-compressed signal at each depth is echo data from a detection target object or data corresponding to a range side lobe. A suppression value determining module 12 determines a suppression value to be used when performing an operation to suppress the range side lobe for data of the pulse-compressed signal at each depth. [0029] A suppression value verifying module 13 verifies whether the suppression value determined by the suppression value determining module 12 is an appropriate value. A suppression ON/OFF module 14 determines whether the suppression process of the range side lobe is to be performed for the data at each depth based on the output result of the suppression range determining module 10 , the output result of the echo determining module 11 , and the verified result of the suppression value verifying module 13 . A suppression conducting module 15 performs a suppression operation of the range side lobe by giving a predetermined calculation with the suppression value determined by the suppression value determining module 12 for the data of the pulse-compressed signal at each depth based on the determination result of the suppression ON/OFF module 14 . [0030] FIG. 3 shows a configuration example of the suppression range determining module 10 . In FIG. 3 , a forward peak-hold module 16 selects data which is the largest in signal strength from the data of the pulse-compressed signals falling into a depth range from each depth concerned to a predetermined deeper depth, respectively, and outputs the selected data as a forward peak-hold value of the depth concerned. Specifically, a forward peak-hold value MPH_F [n] (hereinafter, abbreviated as, “forward PH value”) may be generated using the following Equation (1): [0000] MPH — F[n ]=max( SIGin[n+ 1, n+k ])  (1) [0000] In Equation (1), max(SIGin [n+1,n+k]) represents data with the maximum signal strength among the pulse-compressed signal data from SIGin [n+1] to SIGin [n+k]. The value k is a data number corresponding to the above-described predetermined depth, and it may be desirable to be a number substantially corresponding to a length of the transmission pulse. [0031] A rearward peak-hold module 17 selects data which is the largest in signal strength from the data of the pulse-compressed signals falling into a depth range from each depth concerned to a predetermined shallower depth, respectively, and outputs the selected data as a rearward peak-hold value of the depth concerned. Specifically, the rearward peak-hold value MPH_B [n] (hereinafter, abbreviated as a “rearward PH value”) may be generated by the following Equation (2): [0000] MPH — B[n ]=max( SIGin[n−k+ 1 ,n ])  (2) [0032] The suppression range setting module 18 sets a suppression range to a range where the forward PH value exceeds a predetermined threshold (first threshold) and the rearward PH value does not exceed the threshold. [0033] FIG. 6 shows a particular example in which the forward PH value and the rearward PH value are calculated for the detected pulse-compressed signal and the suppression range is set based on the threshold. In FIG. 6 , the first threshold is set to 120 dB, and a solid line represents the pulse-compressed signal, a dashed dotted line represents the forward PH value, and a two dotted line represents the rearward PH value. [0034] Alternatively, the suppression range determining module 10 may have a configuration in which a pulse-compressed signal is compared with a predetermined threshold, and a range from a position at which the pulse-compressed signal exceeds the threshold to a position shallower by the transmission pulse length is set to be the suppression range. Further, the suppression range determining module 10 may have a configuration in which a range from a seabed position derived by a known seabed detecting method to a position shallower by the transmission pulse length is set to be the suppression range. [0035] FIG. 4 shows a configuration example of the echo determining module 11 . A forward peak-hold module 19 has the same function as the forward peak-hold module 16 of FIG. 3 . The forward peak-hold modules 16 and 19 may also be configured as a single common module having both functions. A division module 20 divides the data MPH_F [n] of the forward PH value at each depth by the value SIGin [n] of the pulse-compressed signal at the depth concerned. A comparison module 21 compares the output result of the division module 20 with a predetermined threshold (second threshold). The comparison module 21 determines the data to be an echo from the detection target object when the output value is less than the second threshold, and determines the data concerned to be data corresponding to a range side lobe when the output value is greater than the second threshold. [0036] FIG. 7 shows a waveform chart of each signal in the echo determining module 11 for the same received data as FIG. 6 . In FIG. 7 , a graph with a dotted line represents a signal generated in the division module 20 . In FIG. 7 , the second threshold is set to approximately 50 dB, and data in ranges other than an echo from a shoal of fish at a seabed is determined to be suppressed. [0037] FIG. 5 shows a configuration example of the suppression value determining module 12 . A suppression offset value calculating module 22 divides an average value derived from a plurality of data within the suppression range (“first average value”) by an average value calculated from data in a predetermined depth range other than the suppression range (“second average value”). The second average value may be calculated from data, for example, in a depth range from a starting position of the suppression range (e.g., an end portion on the shallower side of the suppression range) to a position shallower by the transmission pulse length. The suppression offset value calculating module 22 then outputs the division result as a suppression offset value. It may be desirable to exclude data greater than a predetermined level in the calculation of the first average value and the second average value. [0038] A suppression value calculating module 23 stores in advance a function simulating a standard range side lobe shape that may be obtained by experiments as a suppression function. The suppression value calculating module 23 calculates a suppression value for each data based on a function produced multiplying the suppression function by the suppression offset value calculated by the suppression offset value calculating module 22 . [0039] FIG. 8 shows the calculated results of the first average value, the second average value, the suppression offset value, and the suppression value by the suppression value determining module 12 for the same received data as FIG. 6 . [0040] The suppression value verifying module 13 verifies whether the suppression value determined by the suppression value determining module 12 is an appropriate value. Specifically, the suppression value verifying module 13 verifies whether or not a suppression value which increases range side lobes in the calculation by the suppression conducting module 15 (division of each data by the suppression value) is an inappropriate suppression value (less than 1). [0041] Based on the respective output results from the suppression range determining module 10 , the echo determining module 11 , and the suppression value verifying module 13 , the suppression ON/OFF module 14 determines the suppression process for the data concerned to be performed, when the data falls into the suppression range and corresponds to the range side lobe and when an appropriate suppression value is calculated for the data concerned. [0042] A suppression conducting module 15 performs a division of the data to be suppressed by the suppression value based on the determination result of the suppression ON/OFF module 14 , and outputs it to the display processing module 9 . The suppression conducting module 15 otherwise outputs data not to be suppressed to the display processing module 9 without performing the division. [0043] FIG. 9 is a waveform chart resulting from the range side lobe suppression process performed in the suppression conducting module 15 for the same received data as FIG. 6 . It can be seen that sections that fall into the range side lobes, due to the seabed, are suppressed without the echo signal from the target object near the seabed being weakened. [0044] As described above, although the fishfinder was described as an example, the present invention may also be applied to other underwater detection devices, such as scanning sonar, PPI sonar, etc. In the above embodiment, the intended application is at sea; however, any water application may be possible within the scope of the invention. [0045] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative sense rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued. [0046] Moreover in this document, relational terms such as first and second, top and bottom, 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 relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” “contains,” “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a,” “has . . . a,” “includes . . . a,” “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially,” “essentially,” “approximately,” “approximately” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

An underwater detection device includes a transceiver module for transmitting underwater an ultrasonic pulse signal that is frequency-modulated and receiving an echo signal corresponding to the transmitted signal, a pulse compression module for pulse-compressing the signal received by the transceiver module and outputting a signal pulse-compressed, a suppression range determining module for determining a suppression range where a range side lobe suppression process is performed for the pulse-compressed signal, an echo determining module for determining whether the data of the pulse-compressed signal at each depth corresponding to a range side lobe, a suppression value determining module for determining a suppression value for the data of the pulse-compressed signal at each depth, a suppression conducting module for performing a calculation to suppress the range side lobe based on the suppression value for the data determined to be data of the pulse-compressed signal corresponding to the range side lobe by the echo determining module among a plurality of data of the pulse-compressed signals that fall into the suppression range, and a display processing module for generating a signal for display based on the signal outputted from the suppression conducting module to display a generated signal as detected information.

This application is a division of application Ser. No. 200,676, filed May 31, 1988, U.S. Pat. No. 5,002,851. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to selected methylol-substituted trihydroxybenzophenones as novel compositions of matter. The present invention relates to selected phenolic resins containing at least one unit which is a condensation product of the selected methylol-substituted trihydroxbenzophenones and selected phenolic monomers. Furthermore, the present invention relates to light-sensitive compositions useful as positive-working photoresist compositions, particularly, those containing these phenolic resins and o-quinonediazide photosensitizers. Still further, the present invention also relates to substrates coated with these light-sensitive compositions as well as the process of coating, imaging and developing these light-sensitive mixtures on these substrates. 2. Description of Related Art Photoresist compositions are used in microlithographic processes for making miniaturized electronic components such as in the fabrication of integrated circuits and printed wiring board circuitry. Generally, in these processes, a thin coating or film of a photoresist composition is first applied to a substrate material, such as silicon wafers used for making integrated circuits or aluminum or copper plates of printed wiring boards. The coated substrate is then baked to evaporate any solvent in the photoresist composition and to fix the coating onto the substrate. The baked coated surface of the substrate is next subjected to an image-wise exposure of radiation. This radiation exposure causes a chemical transformation in the exposed areas of the coated surface. Visible light, ultraviolet (UV) light, electron beam and X-ray radiant energy are radiation types commonly used today in microlithographic processes. After this image-wise exposure, the coated substrate is treated with a developer solution to dissolve and remove either the radiation-exposed or the unexposed areas of the coated surface of the substrate. There are two types of photoresist compositions--negative-working and positive-working. When negative-working photoresist compositions are exposed image-wise to radiation, the areas of the resist composition exposed to the radiation become less soluble to a developer solution (e.g. a cross-linking reaction occurs) while the unexposed areas of the photoresist coating remain relatively soluble to a developing solution. Thus, treatment of an exposed negative-working resist with a developer solution causes removal of the non-exposed areas of the resist coating and the creation of a negative image in the photoresist coating, and thereby uncovering a desired portion of the underlying substrate surface on which the photoresist composition was deposited. On the other hand, when positive-working photoresist compositions are exposed image-wise to radiation, those areas of the resist composition exposed to the radiation become more soluble to the developer solution (e.g. a rearrangement reaction occurs) while those areas not exposed remain relatively insoluble to the developer solution. Thus, treatment of an exposed positive-working resist with the developer solution causes removal of the exposed areas of the resist coating and the creation of a positive image in the photoresist coating. Again, a desired portion of the underlying substrate surface is uncovered. After this development operation, the now partially unprotected substrate may be treated with a substrate-etchant solution or plasma gases and the like. This etchant solution or plasma gases etch the portion of the substrate where the photoresist coating was removed during development. The areas of the substrate where the photoresist coating still remains are protected and, thus, an etched pattern is created in the substrate material which corresponds to the photomask used for the image-wise exposure of the radiation. Later, the remaining areas of the photoresist coating may be removed during a stripping operation, leaving a clean etched substrate surface. In some instances, it is desirable to heat treat the remaining resist layer after the development step and before the etching step to increase its adhesion to the underlying substrate and its resistance to etching solutions. Positive-working photoresist compositions are currently favored over negative-working resists because the former generally have better resolution capabilities and pattern transfer characteristics. Photoresist resolution is defined as the smallest feature which the resist composition can transfer from the photomask to the substrate with a high degree of image edge acuity after exposure and development. In many manufacturing applications today, resist resolution on the order of one micron or less are necessary. In addition, it is generally desirable that the developed photoresist wall profiles be near vertical relative to the substrate. Such demarcations between developed and undeveloped areas of the resist coating translate into accurate pattern transfer of the mask image onto the substrate. One drawback with positive-working photoresists known heretofore is their limited resistance to thermal image deformation. This limitation is becoming an increasing problem because modern processing techniques in semiconductor manufacture (e.g. plasma etching, ion bombardment) require photoresist images which have higher image deformation temperatures (e.g. 150° C.-200° C.) Past efforts to increase thermal stability (e.g. increased molecular weight of the resin) generally caused significant decrease in other desirable properties (e.g. decreased photospeed, diminished adhesion, or reduced contrast, poorer developer dissolution rates), or combinations thereof]. Accordingly, there is a need for improved positive-working photoresist formulations which produce images that are resistant to thermal deformation at temperatures of about 150° to 200° C. while maintaining the other desired properties (e.g. developer dissolution rates) at suitable levels. The present invention is believed to be an answer to that need. SUMMARY OF THE INVENTION Accordingly, the present invention is directed to selected methylol-substituted trihydroxybenzophenones of the formula (I): ##STR3## Moreover the present invention is directed to a phenolic novolak resin comprising at least one unit of formula (II): ##STR4## wherein R and R 1 are individually selected from hydrogen, a lower alkyl group having 1 to 4 carbon atoms and a lower alkoxy having 1 to 4 carbon atoms and said unit or units of formula (II) are made by condensing the methylol-substituted trihydroxybenzophenone of formula (I) with selected phenolic monomer units of formula (III): ##STR5## wherein R and R 1 are defined above. Moreover, the present invention is directed to a light-sensitive composition useful as a positive photoresist comprising an admixture of o-quinonediazide compound and binder resin comprising at least one unit of the formula (II), above; the amount of said o-quinonediazide compound or compounds being about 5% to about 40% by weight and the amount of said binder resin being about 60% to 95% by weight, based on the total solid content of said light-sensitive composition. Still further, the present invention also encompasses the process of coating substrates with these light-sensitive compositions and then imaging and developing these coated substrates. Also further, the present invention encompasses said coated substrates (both before and after imaging) as novel articles of manufacture. DETAILED DESCRIPTION The selected methylol-substituted trihydroxybenzophenones of formula (I) are made by reacting the corresponding trihydroxybenzophenone with formaldehyde under alkaline pH conditions. This reaction is illustrated below in reaction equation (A) wherein the trihydroxybenzophenone is 2,3,4-trihydroxybenzophenone and the alkali employed is NaOH and 5-methylol-2,3,4-trihydroxybenzophenone is made: ##STR6## It should be noted that when 2,3,4-trihydroxybenzophenone is employed as the reactant, the reaction occurs almost completely at the 5-position of the trihydroxyphenyl ring. Other isomeric reactions are insignificant. The reason for the selectivity of this particular reaction is the relative electronic activation of the 5-position by the hydroxyl groups on the ring; however, the present invention is not to be limited to any particular reactants or process limitation for this particular type of reaction. In making the class of compounds of the present invention, the precursors are preferably reacted at about a 1:1 mole ratio. The preferred reaction temperature is about 40°-50° C. for about 2.5 hours or less at atmospheric pressure. Excess reaction time may cause undesirable polymerization of the intended product. This reaction preferably occurs at an alkaline pH of greater than 7. The pH may be controlled by the addition of specific amounts of alkaline compounds (e.g. NaOH, KOH, Na 2 CO 3 and the like). The intended product may be recovered from the reaction mixture by mixing the reaction mixture with acidified water and thus precipitating the product in solid form. The phenolic resins containing one or more units of formula (II) above are preferably made by reacting the methylol-substituted trihydroxybenzophenone of formula (I), above, and the selected phenolic monomers having units of formula (III) with formaldehyde under usual novolak-making conditions. Generally, this reaction occurs in the presence of an acid catalyst. Suitable acid catalysts include those commonly employed in acid condensation-type reactions such as HCl, H 3 PO 4 , H 2 SO 4 , oxalic acid, maleic acid, maleic anhydride and organic sulfonic acids (e.g. p-toluene sulfonic acid). The most preferred acid catalyst is oxalic acid. Generally, it is also preferred to carry out the condensation reaction of compounds of formulae (I) with (III) either simultaneously or after the novolak polymerization in the presence of an aqueous medium or an organic solvent. Suitable organic solvents include ethanol, tetrahydrofuran, cellosolve acetate, 1-methoxy-2-propanol and 2-ethoxy ethanol. Preferred solvents are water-soluble solvents such as ethanol, 1-methoxy-2-propanol and 2-ethoxy ethanol. The mole ratio of the methylol-substituted trihydroxybenzophenone to the total of the other phenolic compounds (preferably, a combination of meta- and para-cresols) is generally from about 0.1:99.9 to 20:80; more preferably, about 5:95 to about 10:90. The methylolated trihydroxybenzophenone of formula (I) predominantly reacts in the para-position on the phenolic molecules as illustrated in formula (III), above. For example, this trihydroxybenzophenone compound will predominantly react with phenol or ortho- or meta-cresol, but less favorably with para-substituted phenolic molecules. The thus prepared novolaks containing the units of formula (II), above, have showed greater dissolution rates in aqueous alkaline developers than corresponding novolaks prepared without these units. Furthermore, light-sensitive compositions prepared with novolaks containing these units of formula (II) also showed good thermal stability due to their higher molecular weight and high resolution images. It is also believed that the presence of the units of formula (II) in the novolak resin significantly reduce the degree of branching of the novolak and provide unhindered hydroxyl (OH) groups for improved solubility properties and chemical reactivity. In making the present class of resins, the precursors, namely, the trihydroxybenzophenones of formula (I) and the phenolic monomers (most preferably, a mixture of meta- and para-cresols) are preferably placed in a reaction vessel with formaldehyde. The reaction mixture usually also contains an acid catalyst and solvent as noted above. The mixture is then preferably heated to a temperature in the range from about 60° C. to about 120° C., more preferably from about 65° C. to about 95° C., for both the novolak-forming condensation polymerization reaction and the separate phenolic resin-trihydroxybenzophenone condensation reaction to occur. If an aqueous medium is used instead of an organic solvent, the reaction temperature is usually maintained at reflux, e.g. about 95° C. to 110° C. The reaction time will depend on the specific reactants used and the ratio of formaldehyde to phenolic monomers. The mole ratio of formaldehyde to total phenolic moieties is generally less than about 1:1. Reaction times from 3 to 20 hours are generally suitable. Alternatively, the trihydroxybenzophenones of formula (I) may be first reacted to the phenolic monomers of formula (III) without the presence of formaldehyde. In such cases, the condensation product of formula (II) is made and such condensation products may then be reacted with formaldehyde along with other phenolic monomers to make the novolak resins of the present invention. The most preferred methylol-substituted trihydroxybenzophenone is 5-methylol-2,3,4-trihydroxybenzophenone as shown above in formula (A). The most preferred phenolic monomers is a mixture of meta-cresol and para-cresol having a mole ratio ranging from about 70:30 to about 30:70, respectively. Branched and unbranched novolak resins made from this mixture of meta- and para-cresols will thus include the following types of repeated phenolic units: (1) units of formula (II) above; (2) meta-cresol units of the formula (IV), (IVA) and (IVB): ##STR7## and para-cresol units of formula (V): ##STR8## Regardless of the presence or absence of the further units of formulae (IV) and (V), the resins of the present invention preferably have a molecular weight of from about 500 to about 25,000, more preferably from about 750 to about 20,000. The preferred resins have from about 0.1% to about 30%, more preferably about 5% to 10% by moles of the units of formula (II). The above-discussed resins of the present invention may be mixed with photoactive compounds to make light-sensitive mixtures which are useful as positive acting photoresists. The preferred class of photoactive compounds (sometimes called light sensitizers) is o-quinonediazide compounds particularly esters derived from polyhydric phenols, alkylpolyhydroxyphenones, aryl-polyhydroxyphenones, and the like which can contain up to six or more sites for esterification. The most preferred o-quinonediazide esters are derived from 2-diazo-1,2-dihydro-1-oxo-naphthlene-4-sulfonic acid and 2-diazo-1,2-dihydro-1-oxo-naphthalene-5-sulfonic acid. Specific examples include resorcinol 1,2-naphthoquinonediazide-4-sulfonic acid esters; pyrogallol 1,2-naphthoquinonediazide-5-sulfonic acid esters, 1,2-quinonediazidesulfonic acid esters of (poly)hydroxyphenyl alkyl ketones or (poly)hydroxyphenyl aryl ketones such as 2,4-dihydroxyphenyl propyl ketone 1,2-benzoquinonediazide-4-sulfonic acid esters, 2,4,dihydroxyphenyl hexyl ketone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,4-dihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4-trihydroxyphenyl hexyl ketone, 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,4,6-trihydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,4,6-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,2',4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxy-benzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,2',3,4',6'-pentahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters and 2,3,3',4,4',5'-hexahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters; 1,2-quinonediazidesulfonic acid esters of bis[(poly)hydroxyphenyl]alkanes such as bis(p-hydroxyphenyl)methane 1,2-naphthoquinonediazide-4-sulfonic acid esters, bis(2,4-dihydroxyphenyl)methane 1,2-naphthoquinone-diazide-5-sulfonic acid esters, bis(2,3,4-trihydroxy-phenyl)methane 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,2-bis(p-hydroxyphenyl)propane 1,2-naphthoquinonediazide-4-sulfonic acid esters, 2,2-bis(2,4-dihydroxyphenyl)propane 1,2-naphthoquinonediazide-5-sulfonic acid esters and 2,2-bis(2,3,4-trihydroxyphenyl)propane 1,2-naphthoquinonediazide-5-sulfonic acid esters. Besides the 1,2-quinonediazide compounds exemplified above, there can also be used the 1,2-quinonediazide compounds described in J. Kosar, "Light-Sensitive Systems", 339-352 (1965), John Wiley & Sons (New York) or in S. DeForest, "Photoresist", 50, (1975), MacGraw-Hill, Inc. (New York). In addition, these materials may be used in combinations of two or more. Further, mixtures of substances formed when less than all esterification sites present on a particular polyhydric phenol, alkyl-polyhydroxyphenone, aryl-polyhydroxyphenone and the like have combined with o-quinonediazides may be effectively utilized in positive acting photoresists. Of all the 1,2-quinonediazide compounds mentioned above, 1,2-naphthoquinonediazide-5-sulfonic acid di-, tri-, tetra-, penta- and hexa-esters of polyhydroxy compounds having at least 2 hydroxyl groups, i.e. about 2 to 6 hydroxyl groups, are most preferred. Among these most preferred 1,2-naphthoquinone-5-diazide compounds are 2,3,4-trihydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters, and 2,2',4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-5-sulfonic acid esters. These 1,2-quinonediazide compounds may be used alone or in combination of two or more. The proportion of the light sensitizer compound in the light-sensitive mixture may preferably range from about 5 to about 40%, more preferably from about 10 to about 25% by weight of the non-volatile (e.g. non-solvent) content of the light-sensitive mixture. The proportion of total binder resin of this present invention in the light-sensitive mixture may preferably range from about 60 to about 95%, more preferably, from about 75 to 90% of the non-volatile (e.g. excluding solvents) content of the light-sensitive mixture. These light-sensitive mixtures may also contain conventional photoresist composition ingredients such as other resins, solvents, actinic and contrast dyes, anti-striation agents, plasticizers, speed enhancers, and the like. These additional ingredients may be added to the binder resin and sensitizer solution before the solution is coated onto the substrate. Other binder resins may also be added beside the resins of the present invention mentioned above. Examples include phenolic-formaldehyde resins, cresol-formaldehyde resins, phenol-cresol-formaldehyde resins and polyvinylphenol resins commonly used in the photoresist art. If other binder resins are present, they will replace a portion of the binder resins of the present invention. Thus, the total amount of the binder resin in the light-sensitive composition will be from about 60% to about 95% by weight of the total non-volatile solids content of the light-sensitive composition. The resins and sensitizers may be dissolved in a solvent or solvents to facilitate their application to the substrate. Examples of suitable solvents include methoxyacetoxy propane, ethyl cellosolve acetate, n-butyl acetate, xylene, ethyl lactate, propylene glycol alkyl ether acetates, or mixtures thereof and the like. The preferred amount of solvent may be from about 50% to about 500%, or higher, by weight, more preferably, from about 100% to about 400% by weight, based on combined resin and sensitizer weight. Actinic dyes help provide increase resolution on highly reflective surfaces by inhibiting back scattering of light off the substrate. This back scattering causes the undesirable effect of optical notching, especially on a substrate topography. Examples of actinic dyes include those that absorb light energy at approximately 400-460 nm [e.g. Fat Brown B (C.I. No. 12010); Fat Brown RR (C.I. No. 11285); 2-hydroxy-1,4-naphthoquinone (C.I. No. 75480) and Quinoline Yellow A (C.I. No. 47000)] and those that absorb light energy at approximately 300-340 nm [e.g. 2,5-diphenyloxazole (PPO-Chem. Abs. Reg. No. 92-71-7) and 2-(4-biphenyl)-6-phenyl-benzoxazole (PBBO-Chem. Abs. Reg. No. 17064-47-0)]. The amount of actinic dyes may be up to ten percent weight levels, based on the combined weight of resin and sensitizer. Contrast dyes enhance the visibility of the developed images and facilitate pattern alignment during manufacturing. Examples of contrast dye additives that may be used together with the light-sensitive mixtures of the present invention include Solvent Red 24 (C.I. No. 26105), Basic Fuchsin (C.I. 42514), Oil Blue N (C.I. No. 61555) and Calco Red A (C.I. No. 26125) up to ten percent weight levels, based on the combined weight of resin and sensitizer. Anti-striation agents level out the photoresist coating or film to a uniform thickness. Anti-striation agents may be used up to five percent weight levels, based on the combined weight of resin and sensitizer. One suitable class of anti-striation agents is non-ionic silicon-modified polymers. Non-ionic surfactants may also be used for this purpose, including, for example, nonylphenoxy poly(ethyleneoxy) ethanol; octylphenoxy (ethyleneoxy) ethanol; and dinonyl phenoxy poly(ethyleneoxy) ethanol. Plasticizers improve the coating and adhesion properties of the photoresist composition and better allow for the application of a thin coating or film of photoresist which is smooth and of uniform thickness onto the substrate. Plasticizers which may be used include, for example, phosphoric acid tri-(B-chloroethyl)-ester; stearic acid; dicamphor; polypropylene; acetal resins; phenoxy resins; and alkyl resins up to ten percent weight levels, based on the combined weight of resin and sensitizer. Speed enhancers tend to increase the solubility of the photoresist coating in both the exposed and unexposed areas, and thus, they are used in applications where speed of development is the overriding consideration even though some degree of contrast may be sacrificed, i.e. in positive resists while the exposed areas of the photoresist coating will be dissolved more quickly by the developer, the speed enhancers will also cause a larger loss of photoresist coating from the unexposed areas. Speed enhancers that may be used include, for example, picric acid, nicotinic acid or nitrocinnamic acid at weight levels of up to 20 percent, based on the combined weight of resin and sensitizer. The prepared light-sensitive resist mixture, can be applied to a substrate by any conventional method used in the photoresist art, including dipping, spraying, whirling and spin coating. When spin coating, for example, the resist mixture can be adjusted as to the percentage of solids content in order to provide a coating of the desired thickness given the type of spinning equipment and spin speed utilized and the amount of time allowed for the spinning process. Suitable substrates include silicon, aluminum or polymeric resins, silicon dioxide, doped silicon dioxide, silicon resins, gallium arsenide, silicon nitride, tantalum, copper, polysilicon, ceramics and aluminum/copper mixtures. The photoresist coatings produced by the above described procedure are particularly suitable for application to thermally grown silicon/silicon dioxide-coated wafers such as are utilized in the production of microprocessors and other miniaturized integrated circuit components. An aluminum/aluminum oxide wafer can be used as well. The substrate may also comprise various polymeric resins especially transparent polymers such as polyesters and polyolefins. After the resist solution is coated onto the substrate, the coated substrate is baked at approximately 70° C. to 125° C. until substantially all the solvent has evaporated and only a uniform light-sensitive coating remains on the substrate. The coated substrate can then be exposed to radiation, especially ultraviolet radiation, in any desired exposure pattern, produced by use of suitable masks, negatives, stencils, templates, and the like. Conventional imaging process or apparatus currently used in processing photoresist-coated substrates may be employed with the present invention. In some instances, a post-exposure bake at a temperature about 10° C. higher than the soft bake temperature is used to enhance image quality and resolution. The exposed resist-coated substrates are next developed in an aqueous alkaline developing solution. This solution is preferably agitated, for example, by nitrogen gas agitation. Examples of aqueous alkaline developers include aqueous solutions of tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, ethanolamine, choline, sodium phosphates, sodium carbonate, sodium metasilicate, and the like. The preferred developers for this invention are aqueous solutions of either alkali metal hydroxides, phosphates or silicates, or mixtures thereof, or tetramethylammonium hydroxide. Alternative development techniques such as spray development or puddle development, or combinations thereof, may also be used. The substrates are allowed to remain in the developer until all of the resist coating has dissolved from the exposed areas. Normally, development times from about 10 seconds to about 3 minutes are employed. After selective dissolution of the coated wafers in the developing solution, they are preferably subjected to a deionized water rinse to fully remove the developer or any remaining undesired portions of the coating and to stop further development. This rinsing operation (which is part of the development process) may be followed by blow drying with filtered air to remove excess water. A post-development heat treatment or bake may then be employed to increase the coating's adhesion and chemical resistance to etching solutions and other substances. The post-development heat treatment can comprise the baking of the coating and substrate below the coating's thermal deformation temperature. In industrial applications, particularly in the manufacture of microcircuitry units on silicon/silicon dioxide-type substrates, the developed substrates may then be treated with a buffered, hydrofluoric acid etching solution or plasma gas etch. The resist compositions of the present invention are believed to be resistant to a wide variety of acid etching solutions or plasma gases and provide effective protection for the resist-coated areas of the substrate. Later, the remaining areas of the photoresist coating may be removed from the etched substrate surface by conventional photoresist stripping operations. The present invention is further described in detail by means of the following Examples. All parts and percentages are by weight unless explicitly stated otherwise. EXAMPLE 1 Synthesis of 5-Methylol-2,3,4-trihydroxybenzophenone Employing 2.5 Hours Reaction Time at 40°-47° C. 2,3,4-Trihydroxybenzophenone [300 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, a thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [208 gm 98% by weight NaOH dissolved in 1 liter of distilled water (5.1 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly. A slight exotherm was observed causing the solution temperature to rise to ˜48° C. An aqueous 36.5% by weight formaldehyde solution [123.3 gm (1.5 moles)] was then added dropwise through the addition funnel at a controlled rate so not to cause the reaction temperature to exceed 50° C. Half the formaldehyde solution was added rapidly in five minutes and the second half over a total of 80 minutes. After addition, the reaction was allowed to proceed for an additional 80 minutes before it was acidified with a dilute 37% aqueous hydrochloric acid solution by weight [513 gm (5.2 moles HCl)]. The change in the pH of the solution to a neutral or slightly acidic was associated with a change in its color to a yellowish orange. The reaction solution was transferred to a larger container filled with 3 liters of distilled water under vigorous agitation. The reaction solution was dripped slowly into the agitated water over 30 minutes duration. A light solid precipitate was formed. The solid product was filtered out and dried in a vacuum oven at 50° C. for about 20 hours to remove substantially all water in the product. The dried product weighed 306.5 gm which represented a 90.7% yield based on a theoretical yield of 338 gm. The structure of the above titled compound was confirmed by infrared spectral analysis and by proton NMR. The observed NMR ratio of the aliphatic hydrogens to the aromatic hydrogens was 0.296. Compared with the theoretical ratio value of 0.33 for this compound the product purity is 87.99 by moles. High pressure liquid chromatography detected the presence of approximately 7% by weight of trihydroxybenzophenone starting material indicating that this was the major impurity. EXAMPLE 2 Synthesis of 5-Methylol-2,3,4-trihydroxybenzophenone Employing 2 Hours Reaction Time at 40°-45° C. 2,3,4-Trihydroxybenzophenone [300 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [208 gm 98% by weight NaOH dissolved in 1 liter of distilled water (5.1 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly. A slight exotherm was observed causing the solution temperature to rise to ˜45° C. An aqueous 36.5% by weight formaldehyde solution [123.3 gm (1.5 moles)] was then added dropwise through the addition funnel at a controlled rate so not to cause the reaction temperature to exceed 50° C. Half the formaldehyde solution was added over a period of 70 minutes and the second half over a period of 110 minutes. The reaction solution was poured into a larger container filled with 3 liters of distilled water under vigorous agitation. The reaction mixture was acidified with a dilute 37% aqueous hydrochloric acid solution by weight [513 gm (5.2 moles HCl)]. The change in the pH of the solution to a neutral or slightly acidic was associated with the precipitation of the product in the form of a yellowish orange solid particle. The product was filtered out of solution and reslurried in fresh distilled water three times to wash off trace acid as detected by the neutral pH of the last water wash. The product was dried in a vacuum oven at 50° C. for 24 hours to remove substantially all water. The dried product weighed 320 gm which represented a 94.7% yield based on a theoretical yield of 338 gm. The structure of the above titled compound was confirmed by infrared spectral analysis and by proton NMR. The observed NMR ratio of the aliphatic hydrogens to the aromatic hydrogens was 0.265. Compared with the theoretical ratio value of 0.33 for this compound the product purity is 80.3 moles. High pressure liquid chromatography detected the presence of 8.8% by weight of the trihydroxybenzophenone starting material indicating that this was the major impurity. COMPARISON 1 Synthesis of 5-Methylol-2,3,4-Trihydroxybenzophenone Employing 26 Hours Reaction Time And An Excess Of Formaldehyde 2,3,4-Trihydroxybenzophenone [200 gm (1.3 moles)] was added to a 3 liter, three neck flask equipped with mechanical agitation, thermometer, a condenser and an addition funnel. An aqueous solution of sodium hydroxide [106.5 gm 98% by weight NaOH dissolved in 690 gm of distilled water (2.6 moles NaOH)] was added slowly to the flask. A dark aqueous solution of the trihydroxybenzophenone was formed rapidly. A slight exotherm was observed causing the solution temperature to raise to ˜42° C. An aqueous 36.5% by weight formaldehyde solution [147 gm (1.79 moles)] was added dropwise through the addition funnel in two parts. The first portion of the formaldehyde solution [86 gm (1.05 moles)] was added over a period of 85 minutes. The reaction was then allowed to continue for 22 hours at 40°-42° C. before adding the section portion of the remaining formaldehyde solution [61 gm (0.74 moles)] over a period of 70 minutes. Approximately 70 minutes later the reaction solution was poured into a larger container filled with 3.3 liters of distilled water under vigorous agitation. The reaction mixture was acidified with glacial acetic acid solution (156 gm) added over a 2 hour period at 28° C. The change in the solution acidity to a pH of 4 associated with the precipitation of the product in the form of a yellowish orange solid particle. The product was filtered out of solution and dried in a vacuum oven at 50° C. for 24 hours to remove substantially all water. The dried product weighed 199.4 gm which represented a 88.25% yield based on a theoretical yield of 226 gm. The structure of the above titled compound was not confirmed by proton NMR analysis. The theoretical NMR ratio of the aliphatic hydrogens to the aromatic hydrogens for this compound is 0.33. The observed NMR ratio of the product of this reaction was 0.08 suggesting a low purity mixture. It is postulated that further condensation of the desired product into higher oligmers may have formed under this extended reaction time and at this higher formaldehyde level. EXAMPLE 3 Mixed Cresol Novolak Synthesis Containing 10 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone A mixture of m-cresol [248.28 gm (2.3 moles)], p-cresol [165.5 gm (1.53 moles)], a 37.8% aqueous solution of formaldehyde [228 gm (2.86 moles)] and oxalic acid dihydrate [1 gm (0.0081 moles)] was charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical strirrer, a water cooled condenser, a thermometer, an addition funnel, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to 60° C. before the addition of the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 was started [100 gm dissolved in 285 ml methanol/methoxy-acetoxypropane (about 0.38 moles). This solution was added to the reaction mixture through the addition funnel over a period of 1.5 hours at a temperature range of 100°-83° C. The reaction was allowed to continue at reflux temperature for another 1.5 hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 190° C. as the water and formaldehyde were removed. At this point 335.5 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 2 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 235° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for one hour and 40 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. 420 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 142.5°-143° C. determined by the ring and ball method, ASTM No. 06.03. EXAMPLE 4 Mixed Cresol Novolak Synthesis Containing 5 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone A mixture of m-cresol [135.6 gm (1.25 moles)], p-cresol [90.6 gm (0.84 moles)], a 37.7% aqueous solution of formaldehyde [46.6 gm (0.586 moles)], oxalic acid dihydrate [1 gm (0.0081 moles)] and the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 [30 gm (about 0.13 moles)] were charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to reflux (99°-100° C.) and was allowed to react for three hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 175° C. as the water and formaldehyde were removed. At this point 93 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 50 minutes. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 215° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum, however, it was necessary to hold full vacuum for 25 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. A total of 65 gm of unreacted cresols was collected in the receiving flask at the end of the vacuum distillation. 216 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 156° C. determined by the ring and ball method, ASTM No. 06.03. EXAMPLE 5 Mixed Cresol Novolak Synthesis Containing 7 Mole Percent Of 5-Methylol-2,3,4-Trihydroxybenzophenone A mixture of m-cresol [126 gm (1.17 moles)], p-cresol [84 gm (0.78 moles)], a 36.5% aqueous solution of formaldehyde [121.5 gm (1.483 moles)], oxalic acid dihydrate [1 gm (0.0081 moles)] and the 5-methylol-2,3,4-trihydroxybenzophenone product of Example 1 [40 gm (about 0.13 moles)] were charged into a resin flask. The 1000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to reflux (98° C.) and was allowed to react for three hours before starting atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 200° C. as the water and formaldehyde were removed. The duration of the atmospheric distillation was 1.5 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 227° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for 45 minutes to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. 218 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 160° C. determined by the ring and ball method, ASTM No. 06.03. COMPARISON 2 Mixed Cresol Novolak Synthesis With No 5-Methylol-2,3,4-Trihydroxybenzophenone Added A mixture of m-cresol [607.2 gm (5.62 moles)], p-cresol [404.8 gm (3.75 moles)], a 37.75% aqueous solution of formaldehyde [557 gm (7.03 moles)] and oxalic acid dihydrate 2 gm (0.016Z moles)] was charged into a resin flask. The 2000 ml capacity resin flask used for this reaction was equipped with a mechanical stirrer, a water cooled condenser, a thermometer, an addition funnel, a nitrogen inlet valve and an adequate heating/cooling capacity. The reaction solution was heated up to (100° C.) and was allowed to react at this reflux temperature for four hours before starting the atmospheric distillation. The condenser was adjusted from the reflux vertical position to the horizontal distillation tilted position and a receiving flask was installed at its end. The reaction temperature was raised up to 180° C. as the water and unreacted formaldehyde were removed. At this point 448.5 gm of aqueous distillate was collected in the receiving flask. The duration of the atmospheric distillation was about 2.5 hours. Vacuum was applied gradually to remove unreacted cresols. The maximum temperature allowed during the vacuum distillation was 235° C. at 2 mm/Hg of pressure. Most of the residual unreacted cresols were removed rapidly before applying full vacuum. It was necessary to hold full vacuum for 1.5 hours to insure the removal of essentially all unreacted cresol monomers. Nitrogen gas was used to equalize the pressure inside the flask and to avoid the oxidation of the molten novolak. The novolak was poured into an aluminum tray under an atmosphere of nitrogen and was cooled to room temperature. 838 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 157.5°-157° C. determined by the ring and ball method, ASTM No. 06.03. COMPARISON 3 Mixed Cresol Novolak Synthesis With No 5-Methylol-2,3,4-Trihydroxybenzophenone Added This reaction was carried out in a 500 gallon reactor using a similar cresol mixture as in the above examples (60% m-cresol:40% p-cresol). The formaldehyde molar ratio to cresols was 0.62. The total reaction time employed in this process was 18 hours. In addition, the total duration of the atmospheric distillation was approximately six hours and the vacuum distillation about four hours. The novolak was dissolved in ethyl cellosolve acetate to form a 31.88% solution. This novolak was isolated in the dry solid form by distilling off the solvent from the solution (1887 gm solution) under vacuum at temperatures not exceeding 160° C. in a similar manner to that described above. 710 gm of solid novolak was collected containing less than 0.5% cresol monomers by weight. The softening point of the novolak was 135°-138° C. determined by the ring and ball method, ASTM No. 06.03. Table I below provides dissolution times, softening points and relative average molecular weight data of the novolaks prepared in Examples 3, 4, 5 and Comparisons 2 and 3. The data in Table I shows that 5-methylol-2,3,4-trihydroxybenzophenone-containing novolaks exhibit greater solubilities in aqueous alkaline solutions than the comparison mixed cresol novolaks having similar average molecular weights and softening points. In particular, Example 3 has a faster dissolution time than Comparison 3 and Examples 4 and 5 have a faster dissolution times than Comparison 2. The dissolution times were measured for dry one micron thick novolak coatings required to completely dissolve in an aqueous alkaline solution (HPRD-419 developer sold by Olin Hunt Specialty Products, Inc. of West Paterson, N.J.). Such coatings were prepared from novolak solutions in ethyl cellosolve acetate at approximately 25% solids content by means of spin coating. Silicon or silicon dioxide wafers were used as the coating substrates. The spin speeds employed using a Headway spinner were adjusted between 3000 to 6000 RPM to provide equal one micron coatings for all the novolak solutions according to variations in their solution viscosity as a function of their average molecular weights. The coatings were dried in a Blue M hot air circulating oven at 100°-105° C. for thirty minutes. The average molecular weights (MW) and average molecular number (MN) of these novolaks were measured by gel permination chromatography (GPC) under the following conditions: Column Set: 500, 100, 10,000, 100 and 40 Angstroms Solvent: Tetrahydrofuran Detector: Refractive Index Flow Rate: 1.5 ml/min. Injection Volume: 300 ml Calibration: Polystyrene standards TABLE I______________________________________NovolakExample Molecularor Dissolution Softening WeightComparison Time, Sec. Point MW MN______________________________________Example 3 5 143 3163 342Example 4 68 156 19949 738Example 5 20 160 16252 922Comparison 2 260 157 16630 478Comparison 3 10 138 not determined______________________________________ EXAMPLE 6 Preparation of Resist Solution Novolak prepared according to Example 3 (56 gm) was dissolved in an appropriate solvent (144 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours. A portion of this solution (158.6 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 11.375 gm of the photoactive compound and an additional solvent (27.9 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids. The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone. The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 180 ml resist solution was obtained. EXAMPLE 7 Preparation of Resist Solution Novolak prepared according to Example 4 (56 gm) was dissolved in an appropriate solvent (144 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours. A portion of this solution (150 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 10.65 gm of the photoactive compound and an additional solvent (33.7 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids. The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone. The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 175 ml resist solution was obtained. EXAMPLE 8 Preparation of Resist Solution Novolak prepared according to Example 5 (30 gm) was dissolved in an appropriate solvent (70 gm ethyl lactate) in a 200 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours. A portion of this solution (85 gm) was transferred into a 200 ml size cylindrical amber-colored glass bottle. To this solution 6.375 gm of the photoactive compound and an additional solvent (26.68 gm ethyl lactate) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids. The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone. The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 100 ml resist solution was obtained. COMPARISON 4 Preparation of Resist Solution Novolak prepared according to Comparison 2 (98 gm) was dissolved in an appropriate solvent (252 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours. A portion of this solution (300 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 21.52 gm of the photoactive compound and an additional solvent (67.37 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids. The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone. The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 380 ml resist solution was obtained. COMPARISON 5 Preparation of Resist Solution Novolak prepared according to Comparison 3 (98 gm) was dissolved in an appropriate solvent (252 gm methoxyacetoxypropane) in a 400 ml cylindrical bottle rolled on a high-speed roller for approximately 20 hours. A portion of this solution (300 gm) was transferred into a 400 ml size cylindrical amber-colored glass bottle. To this solution 21.52 gm of the photoactive compound and an additional solvent (46.9 gm methoxyacetoxypropane) were added. The bottle was rolled on a high-speed roller for 12 hours at room temperature to dissolve all solids. The photoactive sensitizer was prepared by reacting 2,3,4-trihydroxybenzophenone with naphthoquinone (1,2)-diazide-5-sulphonyl chloride in a 1:2 molar ratio. The sensitizer resulting from this reaction is a mixture of the sulphono mono-, di- and triesters with trihydroxybenzophenone as well as some unesterified trihydroxybenzophenone. The resulting resist solution was subsequently filtered through a 0.2 um pore-size filter using a millipore microfiltration system (100 ml barrel and a 47 mm disk were used). The filtration was conducted in a nitrogen environment under a pressure of 30 pounds per square inch. Approximately 350 ml resist solution was obtained. PHOTORESIST PROCESSING Coating of Photoresist Composition onto a Substrate Photoresist solutions prepared in Examples 6, 7, 8 and Comparison 4 and 5 were spin-coated with a spinner manufactured by Headway Research Inc. (Garland, Tex.) onto a thermally grown silicon/silicon dioxide-coated wafers of 10 cm (four inches) in diameter and 5000 angstroms in oxide thickness. Uniform coatings, after drying, of approximately 1.2 micron in thickness were obtained at spinning velocities ranging from 4,000 to 7,000 RPM for 30 seconds. In order to obtain approximately identical film thicknesses with all resist solutions, adjustments in the employed spin speed were necessary because of the variations in resist viscosities. Table II below provides the relationship between coating film thickness and spin speed for all the resist samples. TABLE II______________________________________Resin Spin Speed Film DryingComposition × 1000 RPM Thickness Condition______________________________________Example 6 4.0 1.23 100/105° C. 5.0 1.08 30' ovenExample 7 6.5 1.21 100/105° C. 30' ovenExample 8 4.0 1.35 100/105° C. 5.0 1.21 30' oven 7.0 1.02 30' oven 4.0 1.44 110/118° C. 5.0 1.31 50" Hot PlateComparison 4 7.0 1.22 100/105° C. 30' ovenComparison 5 5.0 1.21 100/105° C. 30' oven______________________________________ The coated wafers were baked either in an air circulating convection Blue M oven for 30 minutes at 100°-105° C. or on a hot plate for 50 seconds at a temperature range from 110° to 118° C. The dry film thicknesses were measured with a Sloan Dektak II surface profilometer unit. EXPOSURE OF COATED SUBSTRATES A Perkin-Elmer projection aligner model 340 Micralign was used to provide adequate UV exposures of the above photoresist coated substrates. The spectral output of this instrument covers the range from 310 to 436 nanometers. The light intensity is monitored internally in the instrument. The scan time was varied in order to provide different exposure energies from which the resist sensitivity was determined. A Hunt resolution chromium mask containing groups of lines and spaces, isolated lines and isolated spaces varying in dimensions with minimum features of 1.25 microns. The developed resist features were equal in their dimensions to mask features at the optimum exposure energy. An Ultratech step and repeat 1:1 projection unit, model Ultratech 1000 with a 0.31 numerical aperture was used. This exposure tool provides a narrow spectral output of the G and H Hg lines (436-405 nm). The instrument produces high light intensity and short exposure times measured in milliseconds and controlled accurately by the instrument sensors and the shutter mechanism. Variable exposure energies were used to determine optimum resist exposure energies required to reproduce mask features. The mask used contained groups of lines and spaces, isolated lines and spaces varying in their dimensions with a minimum feature size of 0.75 microns. At optimum exposures the exposed resist image is completely removed by an optimum developer and the image dimension is equal to the corresponding mask image dimension. Optimum developers can be different for each resist formulation. Such developers were determined by obtaining the maximum development contrast between the exposed and the unexposed resist areas where no resist film loss was detected in the unexposed resist areas. Using the above noted mask featuring a group of equal lines and spaces allowed a quick determination of optimum resist exposure energy by microscopic examination of the developed resist images. The accuracy of determining the optimum exposure by this method is within ±5 mJ/Cm 2 . DEVELOPMENT OF EXPOSED RESIST COATED SUBSTRATES A one minute immersion development process was used to develop exposed resist coatings. Two types of developers were employed, a metal containing sodium based developer and a tetramethylammonium hydroxide based, metal ion free developer at different concentrations adjusted for each resist system. The optimum developer concentration selected for each resist provided the minimum unexposed film thickness loss of the resist coating while maximizing its development rate in the exposed areas, thus obtaining the highest development contrast for each system. The developers used and resist sensitivities are presented in Table III. IMMERSION DEVELOPMENT PROCESS The resist coated wafers produced and exposed according to the preceding discussions were placed on circular Teflon boats and immersed in two liter Teflon containers filled with the appropriate developer (shown in Table III) for the duration of one minute. Agitation during the development was provided by means of nitrogen bubbling distributed evenly throughout the tank. Upon removal the wafers were rinsed in distilled water for one minute and blown dry under a stream of nitrogen gas. Table III below provides the developers employed in processing resist samples of Examples 6, 7, 8 and Comparisons 4 and 5 as well as the resulting resist sensitivities. Waycoat Positive LSI Developer ("LSI") sold by Olin Hunt Specialty Products is a metal ion containing developer and was used diluted with distilled water as indicated in Table III. The metal ion free developer Waycoat MIF Developer ("MIF") is also sold by Olin Hunt Specialty Products, was used diluted with distilled water at the concentrations indicated in Table III below. TABLE III______________________________________ Developer Resist Concentration SensitivityResist % LSI % MIF mJ/Cm.sup.2______________________________________Example 6 20 87-94Example 7 28 260 39.5 155 50 117 62 78 70 47-60Example 8 42 150 30 230 32 170Comparison 4 70 93 39 155Comparison 5 33 58 25.5 71______________________________________ RESIST IMAGE QUALITY & THERMAL DEFORMATION MEASUREMENTS A. Image Quality The quality of resist images were examined after development and prior to the hard baking step. Optical microscopic examination as well as electron scan microscopy were used. The qualitative evaluation of resist images was based on the sharpness of the upper edges of resist lines and spaces, the steepness of their profiles and the smoothness of the resist image surfaces. The slope of the vertical line connecting the top edge of the resist image with its bottom edge was used to quantitatively describe the steepness of the side wall profile. In general, low molecular weight novolaks produce better quality resist images. This was also true for the resist systems of this invention. However, resist image quality compared at both low and high molecular weight based novolaks showed better results with novolak systems of this invention over those made with corresponding comparison novolak. This comparison is provided in Tables IV and V below. TABLE 1V______________________________________Low Molecular Weight Novolak Based Resist Systems IMAGE QUALITY Slope Definition ofResist Angle Top Edge Surface______________________________________Example 6 89-90° Very Sharp SmoothComparison 5 85-89° Sharp Smooth______________________________________ TABLE V______________________________________High Molecular Weight Novolak Based Resist Systems IMAGE QUALITY Slope Definition ofResist Angle Top Edge Surface______________________________________Example 7Mild developers 85° Sharp Smooth(39.5%, 50%and 62% LSI)Aggresive 85° Poor Roughdeveloper poor(70% LSI)Example 8Mild developers 85-89° Very Sharp Smooth(42% LSI and30% MIF)Comparison 4Mild developers 85° Poor Smooth(39.5%, 50% poorand 62% LSI)Aggressive 85° Poor Roughdeveloper poor(70% LSI)______________________________________ B. THERMAL DEFORMATION The developed resist images were hard baked in a convection, air circulating Blue M oven at 130° C. for 30 minutes after which the resist images were examined for distortion and thermal flow. This examination was carried out by means of optical microscopy and scan electron microscopy. An additional 30 minutes hard bake at 150° C. was applied only to resist images showing no thermal deformation or flow after the first 130° C. hard bake. The resist thermal image deformation was described by the rounding of the image top edges and the decrease in its profile steepness. These observations were more pronounced at the edges of large resist areas than small lines. Resist systems based on the novolaks of this invention exhibited better resistance to thermal flow than the comparison system as shown in Table VI below. TABLE VI______________________________________ Thermal Image Deformation 130° C. 150° C. Edge Decreased Edge DecreasedRESIST Rounding Slope Rounding Slope______________________________________Example 7 No Slight Yes YesExample 8 No No No YesComparison 4 Yes Yes Yes Yes______________________________________

A methylol-substituted trihydroxybenzophenone of the formula (I): ##STR1## This methylol-substituted trihydroxybenzophenone may be reacted with selected phenolic monomers during or after the formation of a phenolic novolak resin thereby said resin having at least one unit of formula (II): ##STR2## wherein R and R 1 are individually selected from hydrogen, a lower alkyl group having 1 to 4 carbon atoms or a lower alkoxy group having 1 to 4 carbon atoms.

BACKGROUND OF THE INVENTION 1. Field of the Invention The field of invention relates to map holder apparatus, and more particularly pertains to a new and improved wrist mounted map holder apparatus arranged for ease of observation by an individual. 2. Description of the Prior Art Map holders of various types are utilized throughout the prior art, as well as other portable desk-type structure arranged for support of maps. An example is set forth in U.S. Pat. No. 4,415,106 to Connell wherein a map holder includes a support body, with a thin flexible map holder mounted about an individual's limb, including a strap member mounted to the support for visual observation by an individual. U.S. Pat. No. 4,103,809 to Frost, et al. sets forth a pilot's knee pad wherein a strap mounts a desk structure of rigid construction to an individual's knee for use by pilots and the like supporting a writing pad and the like thereon. U.S. Pat. No. 3,821,936 to Morse sets forth a knee pad, wherein a rigid member includes a pivotally mounted rear plate for reception of an individual's leg therewithin. U.S. Pat. No. 4,071,174 to Weiner sets forth a map holder for use with an automotive vehicle, wherein the map holder mounts an articulated linkage for securement to a dashboard, with an overlying magnification lens including a slot for adjustment of the lens relative to an underlying map structure. As such, it may be appreciated that there continues to be a need for a new and improved wrist mounted map holder apparatus as set forth by the instant invention which addresses both the problems of ease of use as well as effectiveness in construction and in this respect, the present invention substantially fulfills this need. SUMMARY OF THE INVENTION In view of the foregoing disadvantages inherent in the known types of map holder apparatus now present in the prior art, the present invention provides a wrist mounted map holder apparatus wherein the same is arranged for securement to an individual's limb for ease of visual observation of a map mounted therewithin. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved wrist mounted map holder apparatus which has all the advantages of the prior art map holder apparatus and none of the disadvantages. To attain this, the present invention provides an elastomeric sleeve, including a transparent pocket, receiving a map therewithin for ease of visual observation by an individual engaged in vehicular transport for example. The invention further includes support apparatus for mounting a magnifying lens and illumination structure for effecting illumination of the map mounted within the holder. My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. It is therefore an object of the present invention to provide a new and improved wrist mounted map holder apparatus which has all the advantages of the prior art map holder apparatus and none of the disadvantages. It is another object of the present invention to provide a new and improved wrist mount map holder apparatus which may be easily and efficiently manufactured and marketed. It is a further object of the present invention to provide a new and improved wrist mounted map holder apparatus which is of a durable and reliable construction. An even further object of the present invention is to provide a new and improved wrist mounted map holder apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such wrist mounted map holder apparatus economically available to the buying public. Still yet another object of the present invention is to provide a new and improved wrist mounted map holder apparatus which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith. These together with other objects of the invention, along with 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 the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: FIG. 1 is an isometric illustration of a prior art map holder structure. FIG. 2 is an isometric illustration of a further prior art map holder structure. FIG. 3 is an isometric illustration of the invention. FIG. 4 is an isometric illustration of a support bar utilized by the invention. FIG. 5 is an enlarged isometric illustration of the support bar and associated supporting strap structure. FIG. 6 is an orthographic view, taken along the lines 6--6 of FIG. 5 in the direction indicated by the arrows. FIG. 7 is an isometric illustration of the magnification lens structure mounted to the support bar. FIG. 8 is an orthographic view, taken in elevation, of the illumination structure utilized by the invention. FIG. 9 is an isometric illustration of the invention in an assembled configuration. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to the drawings, and in particular to FIGS. 1 to 9 thereof, a new and improved wrist mounted map holder apparatus embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described. FIG. 1 illustrates a prior art map holder structure, as set forth in U.S. Pat. No. 4,103,809, wherein a map member is mounted in a flexible manner utilizing straps for securement of the map about a body portion. The prior art structure, as illustrated in FIG. 2, and as set forth in U.S. Pat. No. 4,415,106, is arranged for mounting about an aviator's leg mounting the rigid support plate and note papers thereon. More specifically, the wrist mounted map holder apparatus 10 of the instant invention essentially comprises an elastomeric cylindrical sleeve 11 arranged for securement about a limb portion of an individual, wherein the sleeve includes a transparent pocket 12 fixedly mounted to an exterior surface of the sleeve 11, with the pocket including entrance slot 13 at a forward end of the pocket for directing a map within the pocket structure and permitting its visibility therethrough for ease of viewing. A rigid support bar 14 is provided, with an axial length substantially equal to that defined by the sleeve 11, including a first strap and a second strap 15 and 16 respectively mounted adjacent opposed end portions of the support bar 14, with the first strap including respective first and second hook and loop fastener patches 15a and 15b respectively arranged for securement together, with the second strap 16 including third and fourth respective hook and loop fastener patches 16a and 16b arranged for securement together for mounting the first and second straps 15 and 16 about the sleeve 11, in a manner as illustrated in FIG. 9. The rigid support bar 14 includes a respective first and second support bar groove 17 and 18 formed within respective top and bottom surfaces of the support bar 14 (see FIGS. 5 and 6 for example), wherein the grooves are coextensive with the support bar and are arranged in a parallel relationship relative to one another. A first generally "C" shaped mounting bracket 19 is provided, including first and second bracket ribs 20 and 21 respectively, wherein the first and second ribs 20 and 21 are arranged for sliding reception within respective first and second grooves 17 and 18. A flexible first goose neck support 22 is mounted to the first bracket 19 and includes a magnification lens frame 24 fixedly mounted at an upper terminal end thereof, with the frame 24 including a magnification lens 23 fixedly mounted within the frame 24 to provide ease of visibility of a map mounted within the pocket 12. It should be further noted that the support bar 14 includes a strap slot 25 arranged for each of the straps 15 and 16 for slidably receiving each strap of the first and second straps therethrough for positioning the support bar as required about the sleeve 11. A second "C" shaped mounting bracket 26 is provided wherein the second bracket 26 includes respective third and fourth bracket ribs 27 and 28 also arranged for reception within a respective first and second groove 17 and 18 in a sliding frictional relationship. A battery housing 29 is fixedly mounted to a central web of the second bracket 26, wherein the battery housing 29 includes a switch operative through batteries 31 to effect illumination of an illumination bulb 33 mounted at an upper terminal end of a second flexible goose neck support 32 in electrical communication with the batteries 31 and switch 30. A reflector shield 34 is mounted about the illumination bulb 33 to direct illumination downwardly onto the pocket 12. In this manner, simultaneous illumination and magnification of a map mounted within the pocket 12 is available to an individual. As to the manner of usage and operation of the instant invention, the same should be apparent from the above disclosure, and accordingly no further discussion relative to the manner of usage and operation of the instant invention shall be provided. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

An elastomeric sleeve, including a transparent pocket, receives a map therewithin for ease of visual observation by an individual engaged in vehicular transport for example. The invention further includes support apparatus for mounting a magnifying lens and illumination structure for effecting illumination of the map mounted within the holder.

REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application Serial No. 60/013,350 filed Mar. 13, 1996, and U.S. Provisional Application Serial No. 60/009,180 filed Dec. 22, 1995 BACKGROUND The biological significance of the Ras oncogene, and the role of both Ras and the enzyme known as farnesyl protein transferase in the conversion of normal cells to cancer cells, are described in PCT International Publication Nos. WO95/00497 and WO95/10516. Each of those publications also describes a distinct class of compounds which inhibit the activity of the enzyme farnesyl protein transferase, and thereby the farnesylation of the Ras protein. PCT International Publication No. WO95/10516 relates to tricyclic amide and urea compounds of the general formula (1.0) ##STR2## and their use in a method for inhibiting Ras function and the abnormal growth of cells. A number of sub-generic classes of compounds of formula (1.0) are described, which include compounds of the formulae (5.0c), (5.1c) and (5.2a) ##STR3## as well as the 11-R-isomer and 11-S-isomers of compounds (5.0c) and (5.1c). A number of specific compounds within each such sub-genus are also described therein, as is the biological activity of those compounds. SUMMARY OF THE INVENTION The present invention provides novel tricyclic amide compounds selected from the group consisting of: ##STR4## or pharmaceutically acceptable salts thereof. Optical rotation of the compounds ((+)- or (-)-) are measured in methanol or ethanol at 25° C. This invention includes the above compounds in the amorphous state or in the cyrstalline state. Thus, compounds of this invention include compounds selected from the group consisting of: Compounds 1.0, 2.0, 3.0, 5.0, 6.0, 7.0, 7.0A, 8.0, 8.0A, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, and 17.0, or pharmaceutically acceptable salts thereof, wherein said compounds are as defined above. Compounds of this invention also include compounds selected from the group consisting of: Compounds 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0, 25.0, 26.0, 27.0, 28.0, 29.0, 30.0, 31.0, 32.0, 33.0, 34.0, 35.0, 36.0, 37.0, 38.0, 39.0, 40.0, and 41.0, or pharmaceutically acceptable salts thereof, and wherein said compounds are as defined above. Compounds of this invention also include compounds selected from the group consisting of: (+)-enantiomer Compounds 70.0, 71.0, 72.0, 73.0, 74.0, 75.0, 76.0, 77.0, 78.0, 79.0 and 80.0, or pharmaceutically acceptable salts thereof, and wherein said compounds are as defined above. Also, compounds of this invention include compounds selected from the group consisting of: Compounds 42.0, 43.0, 44.0, 45.0, 46.0, 47.0, 48.0, 49.0, 50.0, 51.0, 52.0, 53.0, 54.0, 55.0, 56.0, 57.0, 58.0, 59.0, 60.0, 61.0, 62.0, 63.0, 64.0, 65.0, 66.0, 67.0, 68.0 and 69.0, or pharmaceutically acceptable salts thereof, wherein said compounds are as defined above. Preferred compounds include the 3,7,8-trihalo compounds having a (-)-optical rotation. For example, Compounds 22.0, 23.0, 25.0 and 27.0. Preferred compounds also include the 3,8,10-trihalo compounds having a (+)-optical rotation. For example, Compounds 29.0, 31.0, 32.0, 34.0, 36.0, 37.0, 39.0 and 41.0. Preferred compounds also include the 3,10-dihalo compounds having a (+)-optical rotation. for example, Compound 20.0. Preferred compounds also include the 3,7-dibromo-8-chloro compounds having S stereochemistry at the C-11 position. For example, Compounds 50.0, 53.0, 55.0 and 57.0. Preferred compounds also include the 3,10-dibromo-8-chlorocompounds having R stereochemistry at the C-11 position. For example, Compounds 62.0, 64.0, 66.0 and 68.0. Preferred compounds also include Compounds 16.0, 17.0, 39.0, 40.0, 41.0, 68.0 and 69.0. More preferred compounds are Compounds 16.0, 39.0, 40.0, 68.0 and 69.0. Most preferred compounds are Compounds 16.0, 39.0 and 68.0. Even more preferred is Compound 39.0 or 68.0. Those skilled in the art will appreciate that the tricyclic ring system is numbered: ##STR5## Those skilled in the art will also appreciate that the S and R stereochemistry at the C-11 bond are: ##STR6## Inhibition of farnesyl protein transferase by the tricyclic compounds of this invention has not been reported previously. Thus, this invention provides a method for inhibiting farnesyl protein transferase using tricyclic compounds of this invention which: (i) potently inhibit farnesyl protein transferase, but not geranylgeranyl protein transferase I, in vitro; (ii) block the phenotypic change induced by a form of transforming Ras which is a farnesyl acceptor but not by a form of transforming Ras engineered to be a geranylgeranyl acceptor; (iii) block intracellular processing of Ras which is a farnesyl acceptor but not of Ras engineered to be a geranylgeranyl acceptor; and (iv) block abnormal cell growth in culture induced by transforming Ras. The compounds of this invention have been demonstrated to have anti-tumor activity in animal models. This invention provides a method for inhibiting the abnormal growth of cells, including transformed cells, by administering an effective amount of a compound of this invention. Abnormal growth of cells refers to cell growth independent of normal regulatory mechanisms (e.g., loss of contact inhibition). This includes the abnormal growth of: (1) tumor cells (tumors) expressing an activated Ras oncogene; (2) tumor cells in which the Ras protein is activated as a result of oncogenic mutation in another gene; and (3) benign and malignant cells of other proliferative diseases in which aberrant Ras activation occurs. This invention also provides a method for inhibiting tumor growth by administering an effective amount of the tricyclic compounds, described herein, to a mammal (e.g., a human) in need of such treatment. In particular, this invention provides a method for inhibiting the growth of tumors expressing an activated Ras oncogene by the administration of an effective amount of the above described compounds. Examples of tumors which may be inhibited include, but are not limited to, lung cancer (e.g., lung adenocarcinoma), pancreatic cancers (e.g., pancreatic carcinoma such as, for example, exocrine pancreatic carcinoma), colon cancers (e.g., colorectal carcinomas, such as, for example, colon adenocarcinoma and colon adenoma), myeloid leukemias (for example, acute myelogenous leukemia (AML)), thyroid follicular cancer, myelodysplastic syndrome (MDS), bladder carcinoma, epidermal carcinoma, breast cancers and prostate cancers. It is believed that this invention also provides a method for inhibiting proliferative diseases, both benign and malignant, wherein Ras proteins are aberrantly activated as a result of oncogenic mutation in other genes--i.e., the Ras gene itself is not activated by mutation to an oncogenic form--with said inhibition being accomplished by the administration of an effective amount of the tricyclic compounds described herein, to a mammal (e.g., a human) in need of such treatment. For example, the benign proliferative disorder neurofibromatosis, or tumors in which Ras is activated due to mutation or overexpression of tyrosine kinase oncogenes (e.g., neu, src, abl, lck, and fyn), may be inhibited by the tricyclic compounds described herein. The compounds of this invention inhibit farnesyl protein transferase and the farnesylation of the oncogene protein Ras. This invention further provides a method of inhibiting ras farnesyl protein transferase, in mammals, especially humans, by the administration of an effective amount of the tricyclic compounds described above. The administration of the compounds of this invention to patients, to inhibit farnesyl protein transferase, is useful in the treatment of the cancers described above. The tricyclic compounds useful in the methods of this invention inhibit the abnormal growth of cells. Without wishing to be bound by theory, it is believed that these compounds may function through the inhibition of G-protein function, such as ras p21, by blocking G-protein isoprenylation, thus making them useful in the treatment of proliferative diseases such as tumor growth and cancer. Without wishing to be bound by theory, it is believed that these compounds inhibit ras farnesyl protein transferase, and thus show antiproliferative activity against ras transformed cells. DETAILED DESCRIPTION OF THE INVENTION As used herein, the following terms are used as defined below unless otherwise indicated: M + -represents the molecular ion of the molecule in the mass spectrum; MH + -represents the molecular ion plus hydrogen of the molecule in the mass spectrum; Pyridyl N-oxides are herein represented by the group ##STR7## The following solvents and reagents are referred to herein by the abbreviations indicated: tetrahydrofuran (THF); ethanol (EtOH); methanol (MeOH); acetic acid (HOAc or AcOH); ethyl acetate (EtOAc); N,N-dimethylformamide (DMF); trifluoroacetic acid (TFA); trifluoroacetic anhydride (TFAA); 1-hydroxy-benzotriazole (HOBT); m-chloroperbenzoic acid (MCPBA); triethylamine (Et 3 N); diethyl ether (Et 2 O); ethyl chloroformate (ClCO 2 Et); 1-(3-dimethylaminopropyl)-3-ethyl carbodiimde hydrochloride (DEC); diisobutylaluminum hydride (DIBAL); isopropanol (iPrOH); dimethylsulfoxide (DMSO) Certain compounds of the present invention may exist in different isomeric forms (e.g., enantiomers or diastereoisomers) including atropisomers (i.e., compounds wherein the 7-membered ring is in a fixed conformation such that the 11-carbon atom is positioned above or below the plane of the fused beznene rings due to the presence of a 10-bromo substituent). The invention contemplates all such isomers both in pure form and in admixture, including racemic mixtures. Enol forms are also included. Certain basic tricyclic compounds also form pharmaceutically acceptable salts, e.g., acid addition salts. For example, the pyrido-nitrogen atoms may form salts with strong acids. Examples of suitable acids for salt formation are hydrochloric, sulfuric, phosphoric, acetic, citric, oxalic, malonic, salicylic, malic, fumaric, succinic, ascorbic, maleic, methanesulfonic and other mineral and carboxylic acids well known to those in the art. The salts are prepared by contacting the free base form with a sufficient amount of the desired acid to produce a salt in the conventional manner. The free base forms may be regenerated by treating the salt with a suitable dilute aqueous base solution such as dilute aqueous NaOH, potassium carbonate, ammonia and sodium bicarbonate. The free base forms differ from their respective salt forms somewhat in certain physical properties, such as solubility in polar solvents, but the acid and base salts are otherwise equivalent to their respective free base forms for purposes of the invention. All such salts are intended to be pharmaceutically acceptable salts within the scope of the invention and all are considered equivalent to the free forms of the corresponding compounds for purposes of the invention. The compounds of the present invention can be prepared by the procedures described below. The compound of Example 10 is obtained in the cyrstalline state. Those skilled in the art will appreciate that compounds obtained in the amorphous state can be obtained in the cyrstalline state by cyrstallizing the amorphous materials from solvents or solvent mixtures such as acetone, diethyl ether, ethyl acetate, ethanol, 2-propanol, tert-butyl ether, water and the like according to procedures well known in the art. Those skilled in the art will also appreciate that the racemic mixture of Compound 7.0A can be made according to the procedures described below. For Example, the intermediate of Preparative Example 6 can be used to prepare Compound 7.0A. PREPARATIVE EXAMPLE 1 ##STR8## Combine 10 g (60.5 mmol) of ethyl 4-pyridylacetate and 120 mL of dry CH 2 Cl 12 at -20° C., add 10.45 g (60.5 mmol) of MCPBA and stir at -20° C. for 1 hour and then at 25° C. for 67 hours. Add an additional 3.48 g (20.2 mmoles) of MCPBA and stir at 25° C. for 24 hours. Dilute with CH 2 Cl 2 and wash with saturated NaHCO 3 (aqueous) and then water. Dry over MgSO 4 , concentrate in vacuo to a residue, and chromatograph (silica gel, 2%-5.5% (10% NH 4 OH in MeOH)/CH 2 Cl 2 )to give 8.12 g of the product compound. Mass Spec.: MH + =182.15 ##STR9## Combine 3.5 g (19.3 mmol) of the product of Step A, 17.5 mL of EtOH and 96.6 mL of 10% NaOH (aqueous) and heat the mixture at 67° C. for 2 hours. Add 2N HC1 (aqueous) to adjust to pH=2.37 and concentrate in vacuo to a residue. Add 200 mL of dry EtOH, filter through celite® and wash the filter cake with dry EtOH (2×50 ml). Concentrate the combined filtrates in vacuo to give 2.43 g of the title compound. PREPARATIVE EXAMPLE 2 ##STR10## The title compound is prepared via the process disclosed in PCT International Publication No. WO95110516, U.S. Pat. No. 5,719,148. PREPARATIVE EXAMPLE 3 ##STR11## Combine 14.95 g (39 mmol) of 8-chloro-11-(1-ethoxy-carbonyl-4-piperidinyl)-11H-benzo 5,6!cyclohepta 1,2-b!pyridine and 150 mL of CH 2 Cl 2 , then add 13.07 g (42.9 mmol) of (nBu) 4 NNO 3 and cool the mixture to 0° C. Slowly add (dropwise) a solution of 6.09 mL (42.9 mmol) of TFAA in 20 mL of CH 2 Cl 2 over 1.5 hours. Keep the mixture at 0° C. overnight, then wash successively with saturated NaHCO 3 (aqueous), water and brine. Dry the organic solution over Na 2 SO 4 , concentrate in vacuo to a residue and chromatograph the residue (silica gel, EtOAc/hexane gradient) to give 4.32 g and 1.90 g of the two product compounds 3A(i) and 3A(ii), respectively. Mass Spec. for compound 3A(i): MH + =428.2. Mass Spec. for compound 3A(ii): MH + =428.3. ##STR12## Combine 22.0 g (51.4 mmol) of the product 3A(i) from Step A, 150 mL of 85% EtOH (aqueous), 25.85 g (0.463 mole) of Fe powder and 2.42 g (21.8 mmol) of CaCl 2 , and heat at reflux overnight. Add 12.4 g (0.222 mole) of Fe powder and 1.2 g (10.8 mmol) of CaCl 2 and heat at reflux for 2 hours. Add another 12.4 g (0.222 mole) of Fe powder and 1.2 g (10.8 mmol) of CaCl 2 and heat at reflux for 2 hours more. Filter the hot mixture through celite®, wash the celite® with 50 mL of hot EtOH and concentrate the filtrate in vacuo to a residue. Add 100 mL of anhydrous EtOH, concentrate to a residue and chromatograph the residue (silica gel, MeOH/CH 2 Cl 2 gradient) to give 16.47 g of the product compound. MH + =398. ##STR13## Combine 16.47 g (41.4 mmol) of the product from Step B, and 150 mL of 48% HBr (aqueous) and cool to -3° C. Slowly add (dropwise) 18 mL of bromine, then slowly add (dropwise) a solution of 8.55 g (0.124 mole) of NaNO 2 in 85 mL of water. Stir for 45 minutes at -3° to 0° C., then adjust to pH=10 by adding 50% NaOH (aqueous). Extract with EtOAc, wash the extracts with brine and dry the extracts over Na 2 SO 4 . Concentrate to a residue and chromatograph (silica gel, EtOAc/hexane gradient) to give 10.6 g and 3.28 g of the two product compounds 3C(i) and 3C(ii), respectively. Mass Spec. for compound 3C(i): MH + =461.2. Mass Spec. for compound 3C(ii): MH + =539. ##STR14## Hydrolyze the product 3C(i) of Step C by dissolving in concentrated HCl and heating to about 100° C. for 16 hours. Cool the mixture, then neutralize with 1M NaOH (aqueous). Extract with CH 2 Cl 2 , dry the extracts over MgSO 4 , filter and concentrate in vacuo to the title compound. Mass Spec.: MH + =466.9. PREPARATIVE EXAMPLE 4 ##STR15## Combine 25.86 g (55.9 mmol) of 4-(8-chloro-3-bromo-5,6-dihydro-11H-benzo 5,6!cyclohepta 1,2-b!pyridin-11-ylidene)- 1 -piperidine-1-carboxylic acid ethyl ester and 250 mL of concentrated H 2 SO 4 at -5° C., then add 4.8 g (56.4 mmol) of NaNO 3 and stir for 2 hours. Pour the mixture into 600 g of ice and basify with concentrated NH 4 OH (aqueous). Filter the mixture, wash with 300 mL of water, then extract with 500 mL of CH 2 Cl 2 . Wash the extract with 200 mL of water, dry over MgSO4, then filter and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 10% EtOAc/CH 2 Cl 2 ) to give 24.4 g (86% yield) of the product. m.p.=165°-167° C., Mass Spec.: MH + =506 (CI). Elemental analysis: calculated-C, 52.13; H, 4.17; N, 8.29 found-C, 52.18; H, 4.51; N, 8.16. ##STR16## Combine 20 g (40.5 mmol) of the product of Step A and 200 mL of concentrated H 2 SO 4 at 20° C., then cool the mixture to 0° C. Add 7.12 g (24.89 mmol) of 1,3-dibromo-5,5-dimethyl-hydantoin to the mixture and stir for 3 hours at 20° C. Cool to 0° C., add an additional 1.0 g (3.5 mmol) of the dibromohydantoin and stir at 20° C. for 2 hours. Pour the mixture into 400 g of ice, basify with concentrated NH 4 OH (aqueous) at 0° C., and collect the resulting solid by filtration. Wash the solid with 300 mL of water, slurry in 200 mL of acetone and filter to provide 19.79 g (85.6% yield) of the product. m.p.=236°-237° C., Mass Spec.: MH + =584 (CI). Elemental analysis: calculated-C, 45.11; H, 3.44; N, 7.17 found-C, 44.95; H, 3.57; N, 7.16. ##STR17## Combine 25 g (447 mmol) of Fe filings, 10 g (90 mmol) of CaCl 2 and a suspension of 20 g (34.19 mmol) of the product of Step B in 700 mL of 90:10 EtOH/water at 50° C. Heat the mixture at reflux overnight, filter through Celite® and wash the filter cake with 2×200 mL of hot EtOH. Combine the filtrate and washes, and concentrate in vacuo to a residue. Extract the residue with 600 mL of CH 2 Cl 2 , wash with 300 mL of water and dry over MgSO4. Filter and concentrate in vacuo to a residue, then chromatograph (silica gel, 30% EtOAc/CH 2 Cl 2 ) to give 11.4 g (60% yield) of the product. m.p.=211°-212° C., Mass Spec.: MH + =554 (CI). Elemental analysis: calculated-C, 47.55; H, 3.99; N, 7.56 found-C, 47.45; H, 4.31; N, 7.49. ##STR18## Slowly add (in portions) 20 g (35.9 mmol) of the product of Step C to a solution of 8 g (116 mmol) of NaNO 2 in 120 mL of concentrated HCl (aqueous) at -10° C. Stir the resulting mixture at 0° C. for 2 hours, then slowly add (dropwise) 150 mL (1.44 mole) of 50% H 3 PO 2 at 0° C. over a 1 hour period. Stir at 0° C. for 3 hours, then pour into 600 g of ice and basify with concentrated NH 4 OH (aqueous). Extract with 2×300 mL of CH 2 Cl 2 , dry the extracts over MgSO 4 , then filter and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 25% EtOAc/hexanes) to give 13.67 g (70% yield) of the product. m.p.=163°-165° C., Mass Spec.: MH + =539 (CI). Elemental analysis: calculated-C, 48.97; H, 4.05; N, 5.22found-C, 48.86; H, 3.91; N, 5.18. ##STR19## Combine 6.8 g (12.59 mmol) of the product of Step D and 100 mL of concentrated HCl (aqueous) and stir at 85° C. overnight. Cool the mixture, pour it into 300 g of ice and basify with concentrated NH 4 OH (aqueous). Extract with 2×300 mL of CH 2 Cl 2 , then dry the extracts over MgSO 4 . Filter, concentrate in vacuo to a residue, then chromatograph (silica gel, 10% MeOH/EtOAc+2% NH4OH (aqueous)) to give 5.4 g (92% yield) of the title compound. m.p.=172°-174° C., Mass Spec.: MH + =467. Elemental analysis: calculated-C, 48.69; H, 3.65; N, 5.97found-C, 48.83; H, 3.80; N, 5.97. PREPARATIVE EXAMPLE 5 ##STR20## Hydrolyze 2.42 g of 4-(8-chloro-3-bromo-5,6-dihydro-11H-benzo 5,6!cyclohepta 1,2-b!pyridin-11-ylidene)-1-piperidine-1-carboxylic acid ethyl ester via substantially the same procedure as described in Preparative Example 3, Step D, to give 1.39 g (69% yield) of the product. MH + =389. ##STR21## Combine 1 g (2.48 mmol) of the product of Step A and 25 mL of dry toluene, add 2.5 mL of 1M DIBAL in toluene and heat the mixture at reflux. After 0.5 hours, add another 2.5 mL of 1M DIBAL in toluene and heat at reflux for 1 hour. (The reaction is monitored by TLC using 50% MeOH/CH 2 Cl 2 +NH 4 OH (aqueous).) Cool the mixture to room temperature, add 50 mL of 1N HCl (aqueous) and stir for 5 min. Add 100 mL of 1N NaOH (aqueous), then extract with EtOAc (3×150 mL). Dry the extracts over MgSO4, filter and concentrate in vacuo to give 1.1 g of the title compound. MH + =391. PREPARATIVE EXAMPLE 6 ##STR22## Combine 16.6 g (0.03 mole) of the product of Preparative Example 4, Step D, with a 3:1 solution of CH 3 CN and water (212.65 mL CH 3 CN and 70.8 mL of water) and stir the resulting slurry overnight at room temperature. Add 32.833 g (0.153 mole) of NaIO 4 and then 0.31 g (2.30 mmol) of RuO 2 and stir at room temperature (the addition of RuO 2 is accompanied by an exothermic reaction and the temperature climbs from 20° to 30° C.). Stir the mixture for 1.3 hrs. (temperature returned to 25° C. after about 30 min.), then filter to remove the solids and wash the solids with CH 2 Cl 2 . Concentrate the filtrate in vacuo to a residue and dissolve the residue in CH2Cl 2 . Filter to remove insoluble solids and wash the solids with CH 2 Cl 2 . Wash the filtrate with water, concentrate to a volume of about 200 mL and wash with bleach, then with water. Extract with 6N HCl (aqueous). Cool the aqueous extract to 0° C. and slowly add 50% NaOH (aqueous) to adjust to pH=4 while keeping the temperature <30° C. Extract twice with CH 2 Cl 2 , dry over MgSO 4 and concentrate in vacuo to a residue. Slurry the residue in 20 mL of EtOH and cool to 0° C. Collect the resulting solids by filtration and dry the solids in vacuo to give 7.95 g of the product. 1 H NMR (CDCl 3 , 200 MHz): 8.7 (s, 1H); 7.85 (m, 6H); 7.5 (d, 2H); 3.45 (m, 2H); 3.15 (m, 2H). ##STR23## Combine 21.58 g (53.75 mmol) of the product of Step A and 500 mL of an anhydrous 1:1 mixture of EtOH and toluene, add 1.43 g (37.8 mmol) of NaBH 4 and heat the mixture at reflux for 10 min. Cool the mixture to 0° C., add 100 mL of water, then adjust to pH≈=4-5 with 1M HCl (aqueous) while keeping the temperature <10° C. Add 250 mL of EtOAc and separate the layers. Wash the organic layer with brine (3×50 mL) then dry over Na 2 SO 4 . Concentrate in vacuo to a residue (24.01 g) and chromatograph the residue (silica gel, 30% hexane/CH 2 Cl 2 ) to give the product. Impure fractions were purified by rechromatography. A total of 18.57 g of the product was obtained. 1 H NMR (DMSO-d 6 , 400 MHz): 8.5 (s, 1H); 7.9 (s, 1H); 7.5 (d of d, 2H); 6.2 (s, 1H); 6.1 (s, 1H); 3.5 (m, 1H); 3.4 (m, 1H); 3.2 (m, 2H). ##STR24## Combine 18.57 g (46.02 mmol) of the product of Step B and 500 mL of CHCl 3 , then add 6.70 mL (91.2 mmol) of SOCl 2 , and stir the mixture at room temperature for 4 hrs. Add a solution of 35.6 g (0.413 mole) of piperazine in 800 mL of THF over a period of 5 min. and stir the mixture for 1 hr. at room temperature. Heat the mixture at reflux overnight, then cool to room temperature and dilute the mixture with 1 L of CH 2 Cl 2 . Wash with water (5×200 mL), and extract the aqueous wash with CHCl 3 (3×100 mL). Combine all of the organic solutions, wash with brine (3×200 mL) and dry over MgSO 4 . Concentrate in vacuo to a residue and chromatograph (silica gel, gradient of 5%, 7.5%, 10% MeOH/CH 2 Cl 2 +NH 4 OH) to give 18.49 g of the title compound as a racemic mixture. ##STR25## The racemic title compound of Step C is separated by preparative chiral chromatography (Chiralpack AD, 5 cm×50 cm column, flow rate 100 mL/min., 20% iPrOH/hexane+0.2% diethylamine), to give 9.14 g of the (+)-enantiomer and 9.30 g of the (-)-enantiomer. Physical chemical data for (+)-enantiomer: m.p.=74.5°-77.5° C.; Mass Spec. MH + =471.9; α! D 25 =+97.4° (8.48 mg/2mL MeOH). Physical chemical data for (-)-enantiomer: m.p.=82.90°-84.5° C.; Mass Spec. MH + =471.8; α! D 25 =-97.4° (8.32 mg/2mL MeOH). PREPARATIVE EXAMPLE 7 ##STR26## Combine 15 g (38.5 mmol) of 4-(8-chloro-3-bromo-5,6-dihydro-11H-benzo 5,6!cyclohepta 1,2-b!pyridin-11-ylidene)-1-piperidine-1-carboxylic acid ethyl ester and 150 mL of concentrated H 2 SO 4 at -5° C., then add 3.89 g (38.5 mmol) of KNO 3 and stir for 4 hours. Pour the mixture into 3 L of ice and basify with 50% NaOH (aqueous). Extract with CH 2 Cl 2 , dry over MgSO 4 , then filter and concentrate in vacuo to a residue. Recrystallize the residue from acetone to give 6.69 g of the product. 1 H NMR (CDCl 3 , 200 MHz): 8.5 (s, 1H); 7.75 (s, 1H); 7.6 (s, 1H); 7.35 (s, 1H); 4.15 (q, 2H); 3.8 (m, 2H); 3.5-3.1 (m, 4H); 3.0-2.8 (m, 2H); 2.6-2.2 (m, 4H); 1.25 (t, 3H). MH + =506. ##STR27## Combine 6.69 g (13.1 mmol) of the product of Step A and 100 mL of 85% EtOH/water, then add 0.66 g (5.9 mmol) of CaCl 2 and 6.56 g (117.9 mmol) of Fe and heat the mixture at reflux overnight. Filter the hot reaction mixture through Celite® and rinse the filter cake with hot EtOH. Concentrate the filtrate in vacuo to give 7.72 g of the product. Mass Spec.: MH + =476.0. ##STR28## Combine 7.70 g of the product of Step B and 35 mL of HOAc, then add 45 mL of a solution of Br 2 in HOAc and stir the mixture at room temperature overnight. Add 300 mL of 1N NaOH (aqueous), then 75 mL of 50% NaOH (aqueous) and extract with EtOAc. Dry the extract over MgSO 4 and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 20%-30% EtOAc/hexane) to give 3.47 g of the product (along with another 1.28 g of partially purified product). Mass Spec.: MH + =554. 1 H NMR (CDCl 3 , 300 MHz): 8.5 (s, 1H); 7.5 (s, 1H); 7.15 (s, 1H); 4.5 (s, 2H); 4.15 (m, 3H); 3.8 (br s, 2H); 3.4-3.1 (m, 4H); 9-2.75 (m, 1H); 2.7-2.5 (m, 2H); 2.4-2.2 (m, 2H); 1.25 (m, 3H). ##STR29## Combine 0.557 g (5.4 mmol) of t-butylnitrite and 3 mL of DMF, and heat the mixture at 60°-70° C. Slowly add (dropwise) a mixture of 2.00 g (3.6 mmol) of the product of Step C and 4 mL of DMF, then cool the mixture to room temperature. Add another 0.64 mL of t-butylnitrite at 40° C. and reheat the mixture to 60°-70° C. for 0.5 hrs. Cool to room temperature and pour the mixture into 150 mL of water. Extract with CH 2 Cl 2 , dry the extract over MgSO 4 and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 10%-20% EtOAc/hexane) to give 0.74 g of the product. Mass Spec.: MH + =539.0. 1 H NMR (CDCl3, 200 MHz): 8.52 (s, 1H); 7.5 (d, 2H); 7.2 (s, 1H); 4.15 (q, 2H); 3.9-3.7 (m, 2H); 3.5-3.1 (m, 4H); 3.0-2.5 (m, 2H); 2.4-2.2 (m, 2H); 2.1-1.9 (m, 2H); 1.26 (t, 3H). ##STR30## Combine 0.70 g (1.4 mmol) of the product of Step D and 8 mL of concentrated HCl (aqueous) and heat the mixture at reflux overnight. Add 30 mL of 1N NaOH (aqueous), then 5 mL of 50% NaOH (aqueous) and extract with CH 2 Cl 2 . Dry the extract over MgSO 4 and concentrate in vacuo to give 0.59 g of the title compound. Mass Spec.: MH + =467. m.p.=123.9°-124.2° C. PREPARATIVE EXAMPLE 8 ##STR31## Prepare a solution of 8.1 g of the title compound from Preparative Example 7 in toluene and add 17.3 mL of a 1M solution of DIBAL in toluene. Heat the mixture at reflux and slowly add (dropwise) another 21 mL of 1M DIBAL/toluene solution over a period of 40 min. Cool the reaction mixture to about 0° C. and add 700 mL of 1M HCl (aqueous). Separate and discard the organic phase. Wash the aqueous phase with CH 2 Cl 2 , discard the extract, then basify the aqueous phase by adding 50% NaOH (aqueous). Extract with CH 2 Cl 2 , dry the extract over MgSO 4 and concentrate in vacuo to give 7.30 g of the title compound, which is a racemic mixture of enantiomers. MH + =469. ##STR32## The racemic title compound of Step A is separated by preparative chiral chromatography (Chiralpack AD, 5 cm×50 cm column, using 20% iPrOH/hexane+0.2% diethylamine), to give the (+)-enantiomer and the (-)-enantiomer of the title compound. Physical chemical data for (+)-enantiomer: m.p.=148.8° C.; Mass Spec. MH + =469; α! D 25 =+65.6° (12.93mg/2mL MeOH). Physical chemical data for (-)-enantiomer: m.p.=112° C.; Mass Spec. MH + =469; α! D 25 =-65.2° (3.65mg/2mL MeOH). PREPARATIVE EXAMPLE 9 ##STR33## Combine 40.0 g (0.124 mole) of the starting ketone and 200 mL of H 2 SO 4 and cool to 0° C. Slowly add 13.78 g (0.136 mole) of KNO 3 over a period of 1.5 hrs., then warm to room temperature and stir overnight. Work up the reaction using substantially the same procedure as described for Preparative Example 4, Step A. Chromatograph (silica gel, 20%, 30%, 40%, 50% EtOAc/hexane, then 100% EtOAc) to give 28 g of the 9-nitro product, along with a smaller quantity of the 7-nitro product and 19 g of a mixture of the 7-nitro and 9-nitro compounds. MH + (9-nitro)=367. ##STR34## React 28 g (76.2 mmol) of the 9-nitro product of Step A, 400 mL of 85% EtOH/water, 3.8 g (34.3 mmol) of CaCl 2 and 38.28 g (0.685 mole) of Fe using substantially the same procedure as described for Preparative Example 4, Step C, to give 24 g of the product. MH + =337. ##STR35## Combine 13 g (38.5 mmol) of the product of Step B, 140 mL of HOAc and slowly add a solution of 2.95 mL (57.8 mmol) of Br 2 in 10 mL of HOAc over a period of 20 min. Stir the reaction mixture at room temperature, then concentrate in vacuo to a residue. Add CH 2 Cl 2 and water, then adjust to pH=8-9 with 50% NaOH (aqueous). Wash the organic phase with water, then brine and dry over Na 2 SO 4 . Concentrate in vacuo to give 11.3 g of the product. 1 H NMR (200 MHZ, CDCl 3 ): 8.73 (d, 1H); 7.74 (d, 1H); 7.14 (s, 1H); 4.63 (s, 2H); 3.23-3.15 (m, 2H); and 3.07-2.98 (m, 2H). ##STR36## Cool 100 mL of concentrated HCl (aqueous) to 0° C., then add 5.61 g (81.4 mmol) of NaNO 2 and stir for 10 min. Slowly add (in portions) 11.3 g (27.1 mmol) of the product of Step C and stir the mixture at 0°-3° C. for 2.25 hrs. Slowly add (dropwise) 180 mL of 50% H 3 PO 2 (aqueous) and allow the mixture to stand at 0° C. overnight. Slowly add (dropwise) 150 mL of 50% NaOH over 30 min., to adjust to pH=9, then extract with CH 2 Cl 2 . Wash the extract with water, then brine and dry over Na 2 SO 4 . Concentrate in vacuo to a residue and chromatograph (silica gel, 2% EtOAc/CH 2 Cl 2 ) to give 8.6 g of the product. MH + =399.9. 1 H NMR (200 MHZ, CDCl 3 ): 8.75 (d, 1H); 7.77 (d, 1H); 7.56 (d, 1H); 7.21 (d, 1H); and 3.3-3.0 (m, 4H). ##STR37## Combine 8.6 g (21.4 mmol) of the product of Step D and 300 mL of MeOH and cool to 0°-2° C. Add 1.21 g (32.1 mmol) of NaBH 4 and stir the mixture at ˜0° C. for 1 hr. Add another 0.121 g (3.21 mmol) of NaBH 4 , stir for 2 hr. at 0° C., then let stand overnight at 0° C. Concentrate in vacuo to a residue then partition the residue between CH 2 Cl 2 and water. Separate the organic phase and concentrate in vacuo (50° C.) to give 8.2 g of the product. 1 H NMR (200 MHZ, CDCl 3 ): 8.44 (d, 1H); 7.63 (d, 1H); 7.47 (d, 1H); 7.17 (d, 1H); 6.56 (d, 1H); 4.17-4.0 (m, 1H); 7.39 (d, 1H); 3.46-3.3 (m, 1H); 3.05-2.74 (m, 2H). ##STR38## Combine 8.2 g (20.3 mmol) of the product of Step E and 160 mL of CH 2 Cl 2 , cool to 0° C., then slowly add (dropwise) 14.8 mL (203 mmol) of SOCl 2 over a 30 min. period. Warm the mixture to room temperature and stir for 4.5 hrs., then concentrate in vacuo to a residue, add CH 2 Cl 2 and wash with 1N NaOH (aqueous) then brine and dry over Na 2 SO 4 . Concentrate in vacuo to a residue, then add dry THF and 8.7 g (101 mmol) of piperazine and stir at room temperature overnight. Concentrate in vacuo to a residue, add CH 2 Cl 2 , and wash with 0.25N NaOH (aqueous), water, then brine. Dry over Na 2 SO 4 and concentrate in vacuo to give 9.46 g of the crude product. Chromatograph (silica gel, 5% MeOH/CH 2 Cl 2 +NH 3 ) to give,3.59 g of the title compound, as a racemate. 1 H NMR (CDCl 3 , 200 MHz): 8.43 (d, 1H); 7.55 (d, 1H); 7.45 (d, 1H); 7.11 (d, 1H); 5.31 (s, 1H); 4.86-4.65 (m, 1H); 3.57-3.40 (m, 1H); 2.98-2.55 (m, 6H); 2.45-2.20 (m, 5H). MH + =470. ##STR39## The racemic title compound from Step F (5.7 g) is chromatographed as described for Preparative Example 6, Step D, using 30% iPrOH/hexane+0.2% diethylamine, to give 2.88 g of the R-(+)-enantiomer and 2.77 g of the S-(-)-enantiomer of the title compound. Physical chemical data for the R-(+)-enantiomer: Mass Spec. MH + =470; α! D 25 =+12.1° (10.9 mg/2mL MeOH). Physical chemical data for the S-(-)-enantiomer: Mass Spec. MH += 470; α! D 25 =-13.2° (11.51 mg/2mL MeOH). PREPARATIVE EXAMPLE 10 ##STR40## Combine 13 g (33.3 mmol) of the title compound from Preparative Example 4, Step D, and 300 mL of toluene at 20° C., then add 32.5 mL (32.5 mmol) of a 1M solution of DIBAL in toluene. Heat the mixture at reflux for 1 hr., cool to 20° C., add another 32.5 mL of 1M DIBAL solution and heat at reflux for 1 hr. Cool the mixture to 20° C. and pour it into a mixture of 400 g of ice, 500 mL of EtOAc and 300 mL of 10% NaOH (aqueous). Extract the aqueous layer with CH 2 Cl 2 (3×200 mL), dry the organic layers over MgSO 4 , then concentrate in vacuo to a residue. Chromatograph (silica gel, 12% MeOH/CH 2 Cl 2 +4% NH 4 OH) to give 10.4 g of the title compound as a racemate. Mass Spec.: MH + =469 (FAB). partial 1H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 7.57 (s, 1H); 7.27 (d, 1H); 7.06 (d, 1H); 3.95 (d, 1H). ##STR41## The racemic title compound of Step A is separated by preparative chiral chromatography (Chiralpack AD, 5 cm×50 cm column, using 5% iPrOH/hexane+0.2% diethylamine), to give the (+)-enantiomer and the (-)-enantiomer of the title compound. Physical chemical data for (+)-enantiomer: Mass Spec. MH + =469 (FABS); α! D 25 =+43.5° (c=0.402, EtOH); partial 1 H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 7.57 (s, 1H); 7.27 (d, 1H); 7.05 (d, 1H); 3.95 (d, 1H). Physical chemical data for (-)-enantiomer: Mass Spec. MH + =469 (FAB); α! D 25 =-41.80 (c=0.328 EtOH); partial 1 H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 7.57 (s, 1H); 7.27 (d, 1H); 7.05 (d, 1H); 3.95 (d, 1H). PREPARATIVE EXAMPLE 11 ##STR42## Treat 4-(8-chloro-3-bromo-5,6-dihydro-11H-benzo 5,6!cyclohepta 1,2-b!pyridin-11-ylidene)-1-piperidine-1-carboxylic acid ethyl ester via substantially the same procedure as described in Preparative Example 6, Steps A-D, to give as the product of Step C, the racemic title compound, and as the products of Step D the R-(+)-enantiomer and S-(-)-enantiomer of the title compound. Physical chemical data for the R-(+)-enantiomer: 13 C NMR (CDCl 3 ): 155.8 (C); 146.4 (CH); 140.5 (CH); 140.2 (C); 136.2 (C); 135.3 (C); 133.4 (C); 132.0 (CH); 129.9 (CH); 125.6 (CH); 119.3 (C); 79.1 (CH); 52.3 (CH 2 ); 52.3 (CH 2 ); 45.6 (CH 2 ); 45.6 (CH 2 ); 30.0 (CH 2 ); 29.8 (CH 2 ). α! D 25 =+25.80 (8.46 mg/2 mL MeOH). Physical chemical data for the S-(-)-enantiomer: 13 C NMR (CDCl 3 ): 155.9 (C); 146.4 (CH); 140.5 (CH); 140.2 (C); 136.2 (C); 135.3 (C); 133.3 (C); 132.0 (CH); 129.9 (CH); 125.5 (CH); 119.2 (C); 79.1 (CH); 52.5 (CH 2 ); 52.5 (CH 2 ); 45.7 (CH 2 ); 45.7 (CH 2 ); 30.0 (CH 2 ); 29.8 (CH 2 ). α! D 25 =-27.9° (8.90 mg/2 mL MeOH). EXAMPLE 1 ##STR43## Dissolve 1.160 g (2.98 mmol) of the title compound from Preparative Example 3 in 20 mL of DMF, stir at room temperature, and add 0.3914 g (3.87 mmol) of 4-methyl-morpholine, 0.7418 g (3.87 mmol) of DEC, 0.5229 g (3.87 mmol) of HOBT, and 0.8795 g (3.87 mmol) of 1-N-t-butoxycarbonyl-piperidinyl-4-acetic acid. Stir the mixture at room temperature for 2 days, then concentrate in vacuo to a residue and partition the residue between CH 2 Cl 2 and water. Wash the organic phase successively with saturated NaHCO 3 (aqueous), 10% NaH 2 PO 4 (aqueous) and brine. Dry the organic phase over MgSO 4 , filter and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 2% MeOH/CH 2 Cl 2 +NH 3 ) to give 1.72 g of the product. m.p.=94.0°-94.5° C., Mass Spec.: MH + =614. Elemental analysis: calculated-C, 60.54; H, 6.06; N, 6.83 found- C, 59.93; H, 6.62; N, 7.45. ##STR44## Combine 1.67 g (2.7 mmol) of the product of Step A and 20 mL of CH 2 Cl 2 and stir at 0° C. Add 20 mL of TFA, stir the mixture for 2 hours, then basify the mixture with 1N NaOH (aqueous). Extract with CH 2 Cl 2 , dry the organic phase over MgSO 4 , filter and concentrate in vacuo to give 1.16 g of the product. m.p.=140.2°-140.8° C., Mass Spec.: MH + =514. ##STR45## Combine 0.50 g of the product of Step B, 20 mL of CH 2 Cl 2 and 4.5 equivalents of (CH 3 ) 3 SiNCO and stir at room temperature for 3 hours. Extract the mixture with saturated NaHCO3 (aqueous) and dry the organic phase over MgSO 4 . Filter and concentrate in vacuo to give 0.8 g of the crude product. Chromatograph the crude product (silica gel, 5% MeOH/CH 2 Cl 2 +NH 3 ) to give 0.26 g of the product. m.p.=170.2°-170.5° C., Mass Spec.: MH + =557. EXAMPLE 2 ##STR46## Combine 0.5 g (1.06 mmol) of the title compound of Preparative Example 4, 0.4 g (2.61 mmol) of the title compound of Preparative Example 1, 5 mL of dry DMF, and 0.5 mL (4.53 mmol) of 4-methylmorpholine, at 0° C., then add 0.6 g (3.12 mmol) of DEC and 0.4 g (2.96 mmol) of HOBT and stir the mixture overnight at 20° C. Concentrate in vacuo to a residue and extract the residue with CH 2 Cl 2 (2×50 mL). Wash the extracts with 25 mL of water, dry over MgSO 4 , then concentrate in vacuo to a residue and chromatograph (silica gel, 10% MeOH/EtOAc+2% NH 4 OH (aqueous)) to give 0.6 g (93.7% yield) of the title compound. Mass Spec.: MH + =602 (FABS); partial 1 H NMR (CDCl 3 , 300 MHz): 8.48 (s, 1H); 8.16 (d, 2H); 7.61 (s, 1H); 7.29 (m, 1H); 7.18 (d, 2H); 7.04 (d, 1H); 3.71 (s, 2H). Elemental analysis: calculated-C, 48.81; H, 4.10; N, 6.57 found-C, 49.10; H, 3.79; N, 6.74. EXAMPLE 3 ##STR47## Dissolve 5.9 g (9.78 mmol) of the title compound of Example 2 in 300 mL of 1:5 CH 2 Cl 2 /EtOAc at 0° C. Slowly add (dropwise) 3 mL of 4N HCl (aqueous) and stir the mixture at 0° C. for 5 min. Add 200 mL of Et 2 O, collect the resulting solids by filtration and wash the solids with 50 mL of Et 2 O. Dry the solids at 20° C. and 0.2 mm Hg to give 5.9 g (96% yield) of the title compound. Mass Spec.: MH + =602 (FAB). partial 1 H NMR (DMSO-d 6 , 300 MHz): δ 8.66 (d, 2H); 8.51 (s, 1H); 7.95 (s, 1H); 7.67 (d, 2H); 7.47 (m, 1H); 7.15 (m, 1H); 3.99 (s, 2H). Elemental analysis: calculated-C, 48.77; H, 3.62; N, 6.56 found-C, 48.34; H, 3.95; N, 6.84. EXAMPLE 4 ##STR48## Combine 0.501 g (1.28 mmol) of the title compound of Preparative Example 5 and 20 mL of dry DMF, then add 0.405 g (1.664 mmol) of 1-N-t-butoxycarbonylpiperidinyl-4-acetic acid, 0.319 g (1.664 mmol) of DEC, 0.225 g (1.664 mmol) of HOBT, and 0.168 g (1.664 mmol) of 4-methylmorpholine and stir the mixture at room temperature overnight. Concentrate the mixture in vacuo to a residue, then partition the residue between 150 mL of CH 2 Cl 2 and 150 mL of saturated NaHCO 3 (aqueous). Extract the aqueous phase with another 150 mL of CH 2 Cl 2 . Dry the organic phase over MgSO4, and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 500 mL hexane, 1 L of 1% MeOH/CH 2 Cl 2 +0.1% NH 4 OH (aqueous), then 1 L of 2% MeOH/CH 2 Cl 2 +0.1% NH 4 OH (aqueous)) to give 0.575 g of the product. m.p.=115°-125° C.; Mass Spec.: MH + =616. ##STR49## Combine 0.555 g (0.9 mmol) of the product of Step A and 15 mL of CH 2 Cl 2 and cool the mixture to 0° C. Add 15 mL of TFA and stir at 0° C. for 2 hours. Concentrate in vacuo at 40°-45° C. to a residue, then partition the residue between 150 mL of CH 2 Cl 2 and 100 mL of saturated NaHCO 3 (aqueous). Extract the aqueous layer with 100 mL of CH 2 Cl 2 , combine the extracts and dry over MgSO 4 . Concentrate in vacuo to give 0.47 g of the product. m.p.=140°-150° C.; Mass Spec.: MH + =516. ##STR50## Combine 0.449 g (0.87 mmol) of the product of Step B, 20 mL of CH 2 Cl 2 and 0.501 g (0.59 mmol) of (CH 3 ) 3 SiNCO and stir at room temperature overnight. Add 50-75 mL of saturated NaHCO 3 (aqueous) and stir for 0.5 hours. Dilute with CH 2 Cl 2 , separate the layers and extract the aqueous layer with 2×100 mL of CH 2 Cl 2 . Dry the combined CH2Cl 2 extracts over MgSO 4 and concentrate in vacuo to a residue. Chromatograph the residue (silica gel, 500 mL CH 2 Cl 2 ; 1 L of 1% MeOH/CH 2 Cl 2 +0.1% NH 4 OH; 1 L of 2% MeOH/CH 2 Cl 2 +0.2% NH 4 OH; then with 3% MeOH/CH 2 Cl 2 +0.3% NH 4 OH) to give 0.33 g of the title compound. m.p.=145°-155° C.; Mass Spec.: MH + =559. EXAMPLE 5 ##STR51## Combine 3.0 g (6.36 mmol) of the (-)-enantiomer of the title compound from Preparative Example 6, Step D, and 70 mL of dry DMF. Add 3.84 mL (34.94 mmol) of N-methylmorpholine, 3.28 g (17.11 mmol) of DEC, 2.23 g (16.52 mmol) of HOBT and 2.09 (13.55 mmol) of 4-pyridylacetic acid N-oxide from Preparative Example 1 and stir the mixture at room temperature overnight. Concentrate in vacuo to remove the DMF, add 100 mL of saturated NaHCO 3 (aqueous) and 10 mL of CH 2 Cl 2 and stir for 15 min. Extract the mixture with CH 2 Cl 2 (2×500 mL), dry the extracts over MgSO 4 and concentrate in vacuo to a residue. Chromatograph the residue (500 g reverse phase C18 silica, gradient of 75%, 80%, then 85% MeOH/water+0.1% HOAc). Concentrate the desired fractions in vacuo to remove MeOH and add 50 mL of 1M NaOH (aqueous). Stir for 15 min., then extract with CH 2 Cl 2 (2×500 mL). Dry the extract over MgSO 4 and concentrate in vacuo to give 3.4 g of the title compound. m.p.=148.9°-150.5° C.; α! D 25 =-56.37° (9.4 mg/2 mL MeOH); Mass Spec. MH + =605. The title compound of Example 5 can also be isolated as its HCl salt by treating a solution of the product in HCl and CH 2 Cl 2 at room temperature, followed by concentration in vacuo to give the HCl salt. α! D 25 =-31.90° (4.80 mg/2 mL MeOH+1 mL of water). Using the (+)-enantiomer of the product of Preparative Example 6 and following essentially the same procedure as described above for Example 5, the analogous (+)-enantiomer (Example 5A), i.e., the enantiomer of the title compound of Example 5, is prepared. m.p.=149.0°-150.5° C.; Mass Spec.: MH + =605; α! D 25 =+67.1° (7.0 mg/2mL MeOH). The title compound of Example 5A can also be isolated as its HCl salt as described above for Example 5. m.p.=152.9° C. (dec.); α! D 25 =+41.7° (2 mL MeOH+1 mL of water). Using the racemic title compound of Preparative Example 6, Step C, and following essentially the same procedure as described above for Example 5, the racemate (Example 5B), is prepared. m.p.=84.3°-85.6° C.; Mass Spec.: MH + =607. EXAMPLE 6 ##STR52## Combine 3.21 g (6.80 mmol) of the (-)-enantiomer product of Preparative Example 6 and 150 mL of anhydrous DMF. Add 2.15 g (8.8 mmol) of 1-N-t-butoxycarbonylpiperidinyl-4-acetic acid, 1.69 g (8.8 mmol) of DEC, 1.19 g (8.8 mmol) of HOBT and 0.97 mL (8.8 mmol) of N-methylmorpholine and stir the mixture at room temperature overnight. Concentrate in vacuo to remove the DMF and add 50 mL of saturated NaHCO 3 (aqueous). Extract with CH 2 Cl 2 (2×250 mL), wash the extracts with 50 mL of brine and dry over MgSO 4 . Concentrate in vacuo to a residue and chromatograph (silica gel, 2% MeOH/CH 2 Cl 2 +10% NH 4 OH) to give 4.75 g of the product. m.p.=75.7°-78.5° C.; Mass Spec.: MH + =695; α! D 25 =-5.5° (6.6 mg/2 mL MeOH). ##STR53## Combine 4.70 g (6.74 mmol) of the product of Step A and 30 mL of MeOH, then add 50 mL of 10% H 2 SO 4 /dioxane in 10 mL aliquots over a 1 hr. period. Pour the mixture into 50 mL of water and add 15 mL of 50% NaOH (aqueous) to adjust to pH≈10-11. Filter to remove the resulting solids and extract the filtrate with CH 2 Cl 2 (2×250 mL). Concentrate the aqueous layer in vacuo to remove the MeOH and extract again with 250 mL of CH 2 Cl 2 . Dry the combined extracts over MgSO 4 and concentrate in vacuo to give the product. m.p.=128.1°-131.5° C.; Mass Spec.: MH + =595; α! D 25 =-6.02° (9.3 mg/2 mL MeOH). ##STR54## Combine 3.64 g (5.58 mmol) of the product of Step B and 30 mL of CH 2 Cl 2 , then add 6.29 mL (44.64 mmol) of (CH 3 ) 3 SiNCO and stir the mixture for 2 days at room temperature. Add 25 mL of NaHCO 3 (aqueous), then extract with CH 2 Cl 2 (2×250 mL). Wash the extracts with 25 mL of brine and dry over MgSO 4 . Concentrate in vacuo to a residue and chromatograph (silica gel, gradient of 2.5%, 5.0%, then 7.5% MeOH/CH 2 Cl 2 +10% NH 4 OH) to give the title compound. m.p.=150.5°-153.0° C.; Mass Spec.: MH + =638; α! D 25 =-61.4° (8.18 mg/2 mL MeOH). EXAMPLE 7 ##STR55## React the title compound of Preparative Example 7 and the title compound of Preparative Example 1 using substantially the same procedure as described for Example 2, to give 0.25 g of the title compound, which is a racemic mixture of atropisomers. Mass Spec.: MH + =602. m.p.=167.2°-167.8° C. The HCl salt of the title compound of Example 7 is prepared by stirring for 1 hr. with HCl/CH 2 Cl 2 , then concentrating in vacuo to give the salt. EXAMPLES 7A & 7B ##STR56## The title compound of Example 7 is a racemic mixture of atropisomers. Those atropisomers are separated by preparative chromatography (HPLC), using an Chiralpack AD column (5 cm×50 cm) and 40% i-PrOH/hexane+0.2% diethylamine as the mobile phase to give the (+)- and (-)-enantiomers, Examples 7B and 7A, respectively. Physical chemical data for (-)-enantiomer, Example 7A: m.p.=114.2°-114.8° C.; α! D 25 =-154.6° (8.73 mg/2 mL, MeOH). Physical chemical data for (+)-enantiomer, Example 7B: m.p.=112.6°-113.5° C.; α! D 25 =+159.7° (10.33 mg/2 mL, MeOH). EXAMPLE 8 ##STR57## React 6.0 g (12.8 mmol) of the title compound of Preparative Example 7 and with 3.78 g (16.6 mmol) of 1-N-t-butoxycarbonylpiperidinyl-4-acetic acid using substantially the same procedures as described for Example 6, Step A, to give 8.52 g of the product. Mass Spec.: MH + =692 (FAB). 1 H NMR (CDCl 3 , 200 MHz): 8.5 (d, 1H); 7.5 (d, 2H); 7.2 (d, 1H); 4.15-3.9 (m, 3H); 3.8-3.6 (m, 1H); 3.5-3.15 (m, 3H); 2.9 (d, 2H); 2.8-2.5 (m, 4H); 2.4-1.8 (m, 6H); 1.8-1.6 (br d, 2H); 1.4 (s, 9H); 1.25-1.0 (m, 2H). ##STR58## Combine 8.50 g of the product of Step A and 60 mL of CH 2 Cl 2 , then cool to 0° C. and add 55 mL of TFA. Stir the mixture for 3 h at 0° C., then add 500 mL of 1N NaOH (aqueous) followed by 30 mL of 50% NaOH (aqueous). Extract with CH 2 Cl 2 , dry over MgSO4 and concentrate in vacuo to give 7.86 g of the product. Mass Spec.: MH + =592 (FAB). 1 H NMR (CDCl 3 , 200 MHz): 8.51 (d, 1H); 7.52 (d of d, 2H); 7.20 (d, 1H); 4.1-3.95 (m, 2H); 3.8-3.65 (m, 2H); 3.5-3.05 (m, 5H); 3.0-2.5 (m, 6H); 2.45-1.6 (m, 6H);1.4-1.1 (m, 2H). ##STR59## Treat 7.80 g (13.1 mmol) of the product of Step B with 12.1 g (105 mmol) of (CH 3 ) 3 SiNCO using substantially the same procedure as described for Example 6, Step C, to give 5.50 g of the title compound, which is a racemic mixture of atropisomers. m.p.=163.6°-164.0° C. Mass spec.: MH + =635 (FAB). 1 H NMR (CDCl 3 , 200 MHz): 8.5 (d, 1H); 7.52 (d, 1H); 7.48 (d, 1H); 7.21 (d, 1H); 4.54, (s, 2H); 4.1-3.6 (m, 4H); 3.45-3.15 (m, 4H); 3.0-2.5 (m, 5H); 2.45-1.6 (m, 7H); 1.4-1.0, (m, 2H). EXAMPLES 8A & 8B ##STR60## The title compound of Example 8 is a racemic mixture of atropisomers. Those atropisomers are separated by preparative chromatography (HPLC), using an Chiralpack AD column (5 cm×50 cm) and 20% i-PrOH/hexane+0.2% diethylamine as the mobile phase, at a flow rate of 100 mL/min., to give the (+)- and (-)-enantiomers, Examples 8B and 8A, respectively. Physical chemical data for (-)-enantiomer, Example 8A: m.p.=142.9°-143.5° C.; α! D 25 =-151.7° (11.06 mg/2 mL, MeOH). Physical chemical data for (+)-enantiomer, Example 8B: m.p.=126.5°-127.0° C.; α! D 25 =+145.6° (8.38 mg/2 mL, MeOH). EXAMPLE 9 ##STR61## Combine 3.32 g of the (+)-enantiomer of the title compound of Preparative Example 8, Step B, 2.38 g of the title compound of Preparative Example 1, 1.92 g of HOBT, 2.70 g of DEC, 1.56 mL of N-methylmorpholine and 50 mL of dry DMF and stir at 25° C. for 24 hrs. Concentrate in vacuo, then dilute the residue with CH 2 Cl 2 . Wash with 1N NaOH (aqueous), then with saturated NaH 2 PO 4 (aqueous) and dry over MgSO 4 . Concentrate in vacuo to a residue and chromatograph (silica gel, 2% MeOH/CH 2 Cl 2 +NH 4 OH) to give 3.82 g of the title compound. Mass Spec.: MH + =604 (FAB). The hydrochloride salt was prepared by dissolution of the title compound from Example 9 in dichloromethane saturated with hydrogen chloride. Concentration in vacuo provided the title compound from Example 9 as the HCl salt. m.p.=166.5° C; α! D 25 =+70.8° (9.9 mg/2mL MeOH). EXAMPLES 9A & 9B ##STR62## The (-)-enantiomer of the title compound of Preparative Example 8, Step B, (3.38 g) is reacted with 2.20 g of the title compound of Preparative Example 1, via substantially the same procedure as described for Example 9 to give 3.58 g of the title compound of Example 9A. The HCl salt of the title compound of Example 9A is prepared by dissolving of the title compound in CH 2 Cl 2 , adding 6M HCl (g) in CH 2 Cl 2 , then concentrating in vacuo to give the salt. m.p.=129° C.; α! D 25 =-72.3° (3.32mg/2mL MeOH). The racemic title compound of Preparative Example 8, Step A, is reacted with the title compound of Preparative Example 1, via substantially the same procedure as described for Example 9 to give the title compound of Example 9B. m.p.=145.0° C. EXAMPLE 10 ##STR63## React 1.33 g of the (+)-enantiomer of the title compound of Preparative Example 8, Step B, with 1.37 g of 1-N-t-butoxy-carbonylpiperidinyl-4-acetic acid using substantially the same procedures as described for Example 6, Step A, to give 2.78 g of the product. Mass Spec.: MH + =694.0 (FAB); α! D 25 =+34.1° (5.45 mg/2 mL, MeOH). ##STR64## Treat 2.78 g of the product of Step A via substantially the same procedure as described for Example 8, Step B, to give 1.72 g of the product. m.p.=104.1° C.; Mass Spec.: MH + =594; α! D 25 =+53.4° (11.42 mg/2 mL, MeOH). ##STR65## Treat 1.58 g of the product of Step B with 6 mL of (CH 3 ) 3 SiNCO using substantially the same procedure as described for Example 6, Step C, to give 1.40 g of the title compound. m.p.=140° C.; Mass spec.: MH + =637; α! D 25 =+49.10 (4.24mg/2 mL, MeOH). Recrystallization from acetone provided the title compound as a solid. m.p.=214.5°-215.9° C. EXAMPLES 10A & 10B ##STR66## The (-)-enantiomer of the title compound of Preparative Example 8, Step B, (3.38 g) is converted to the title compound (Example 10A) via substantially the same procedure as described for Example 10, Steps A-C, to give the title compound Example 10A. m.p.=152° C.; Mass spec.: MH + =637; α! D 25 =-62.50 (1,12mg/2mL MeOH). The racemic title compound of Preparative Example 8, Step A, is converted to the title compound (Example 9B) via substantially the same procedure as described for Example 10, Steps A-C to give the title compound Example 10B. m.p.=111.2° C. (dec). EXAMPLE 11 ##STR67## The title compound is prepared using the racemic title compound from Preparative Example 9, Step F, following substantially the same procedure as described for Example 2. 1 H NMR (CDCl 3 , 400 MHz): 8.44 (d, 1H); 8.14 (d, 2H): 7.58 (d, 1H); 7.47 (d, 1H); 7.14 (m, 3H); 5.32 (s, 1H); 4.65-4.57 (m, 1H); 3.68 (s, 2H); 3.65-3.39 (m, 4H); 2.91-2.87 (m, 1H); 2.69-2.63 (m, 1H); 2.45-2.33 (m, 4H). MH + =605. EXAMPLES 11A & 11B ##STR68## Using the R(+)- or S(-)-enantiomer of the title compound from Preparative Example 9, Step G, the R(+)-enantiomer (Example 11A) or the S-(-)-enantiomer (Example 11B) is prepared using substantially the same procedure as described for Example 2. Physical chemical data for R-(+)-enantiomer, Example 11A: m.p.=167.0°-167.8° C.; α! D 25 =+32.6° (c=1, MeOH); 1 H NMR (CDCl 3 , 400 MHz): 8.44 (d, 1H); 8.14 (d, 2H): 7.58 (d, 1H); 7.47 (d, 1H); 7.14 (m, 3H); 5.32 (s, 1H); 4.65-4.57 (m, 1H); 3.68 (s, 2H); 3.65-3.39 (m, 4H); 2.91-2.87 (m, 1H); 2.69-2.63 (m, 1H); 2.45-2.33 (m, 4H). MH + =605. Physical chemical data for S-(-)-enantiomer, Example 11B: α! D 25 =-38.2° (14.67 mg/2 mL, MeOH); 1 H NMR (CDCl 3 , 400 MHz): 8.44 (d, 1H); 8.14 (d, 2H): 7.58 (d, 1H); 7.47 (d, 1H); 7.14 (m, 3H); 5.32 (s, 1H); 4.64-4.57 (m, 1H); 3.67 (s, 2H); 3.70-3.34 (m, 4H); 2.95-2.87 (m, 1H); 2.69-2.63 (m, 1H); 2.45-2.31 (m, 4H). MH + =605. EXAMPLE 12 ##STR69## The title compound of this Example is prepared using the racemic title compound from Preparative Example 9, Step F, by following substantially the same procedures as described for Example 8, Steps A-C. This compound is a racemate. EXAMPLES 12A & 12B ##STR70## The title compound of Example 12 is a racemic mixture. Chromatograph 2.45 g of the compound of Example 12, using an Chiralpack AD column and 20% i-PrOH/hexane+0.2% diethylamine as the mobile phase, at a flow rate of 100 mL/min., to give 0.970 g of the (+)-enantiomer and 0.982 g of the (-)-enantiomer, Examples 12B and 12A, respectively. Physical chemical data for (-)-enantiomer, Example 12A: 1 H NMR (CDCl 3 , 200 MHz): 8.43 (d, 1H); 7.58 (d, 1H); 7.48 (d, 1H); 7.14 (d, 1H); 5.32 (s, 1H); 4.5-4.75 (m, 1H); 4.4 (s, 2H); 3.9 (d, 2H); 3.2-3.7 (m, 5H); 2.52-3.05 (m, 4H); 1.85-2.5 (m, 6H); 1.5-1.85 (m, 4H); 1.0-1.4 (m, 1H). α! D 25 =-31.2° (c=0.453, MeOH). Physical chemical data for (+)-enantiomer, Example 12B: 1 H NMR (CDCl 3 , 200 MHz): 8.43 (d, 1H); 7.58 (d, 1H); 7.48 (d, 1H); 7.14 (d, 1H); 5.32 (s, 1H); 4.5-4.75 (m, 1H); 4.4 (s, 2H); 3.9 (d, 2H); 3.2-3.7 (m, 5H); 2.52-3.05 (m, 4H); 1.85-2.5 (m, 6H); 1.5-1.85 (m, 4H); 1.0-1.4 (m, 1H). α! D 25 =+29.80 (c=0.414, MeOH). EXAMPLE 13 ##STR71## React 1.35 g of the (-)-enantiomer of the title compound of Preparative Example 10, Step B, with 1.4 g of 1-N-t-butoxy-carbonylpiperidinyl-4-acetic acid following substantially the same procedures as described for Example 6, Step A, to give 2.0 g of the product. Mass Spec.: MH + =694 (FAB). partial 1 H NMR (CDCl 3 , 300 MHz): 8.38 (s, 1H); 7.60 (s, 1H); 7.25 (d, 1H); 7.05 (m, 1H); 1.45 (s, 9H). ##STR72## Treat 1.95 g of the product of Step A via substantially the same procedure as described for Example 8, Step B, to give 1.63 g of the product. Mass Spec. MH + =594 (FAB). Partial 1 H NMR (CDCl 3 , 300 MHz): 8.38 (s, 1H); 7.60 (s, 1H); 7.25 (d, 1H); 7.03 (m, 1H); 4.64 (d, 1H); 3.90 (m, 2H). ##STR73## Treat 1.6 g of the product of Step B with 1.3 mL of (CH 3 ) 3 SiNCO using substantially the same procedure as described for Example 6, Step C, to give 1.27 g of the title compound. Mass spec.: MH + =637 (FABS); α! D 25 =-33.1° (c=0.58, EtOH). partial 1 H NMR (CDC1 3 , 400 MHz): 8.38 (s, 1H); 7.59 (s, 1H); 7.25 (d, 1 H); 7.04 (m, 1H); 4.60 (d, 1H); 4.41 (s, 2H). EXAMPLES 13A & 13B ##STR74## The (+)-enantiomer of the title compound from Preparative Example 10, Step B, (2.1 g) is converted to the title compound via substantially the same procedure as described for Example 10, Steps A-C, to give the title compound, Example 13A. Mass spec.: MH + =637 (FABS); α! D 25 =+32.4° (c=0.57, EtOH). Partial 1 H NMR (CDCl 3 , 400 MHz): 8.39 (s, 1H); 7.59 (s, 1H); 7.25 (d, 1H); 7.04 (m, 1H); 4.60 (d, 1H); 4.41 (s, 2H). partial 1 H NMR (DMSO-d 6 , 400 MHz): 8.42 (s, 1H); 7.88 (s, 1H); 7.41 (d, 1H); 7.29 (m, 1H); 5.85 (s, 2H); 4.20 (d, 1H). The racemic title compound from Preparative Example 10, Step A, is converted to the racemic title compound, Example 13B, in an analogous manner. Partial 1 H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 7.59 (s, 1H); 7.25 (d, 1H); 7.04 (m, 1H); 4.60 (d, 1H); 4.41 (s, 2H). partial 1 H NMR (DMSO-d 6 , 400 MHz): 8.42 (s, 1H); 7.88 (s, 1H); 7.41 (d, 1H); 7.29 (d, 1H); 5.85 (s, 2H); 4.20 (d, 1H). EXAMPLE 14 ##STR75## React 2.6 g of the (+)-enantiomer of the title compound of Preparative Example 10, Step B, and 1.68 g of the title compound of Preparative Example 1 following substantially the same procedure as described for Example 9 to give 2.10 g of the title compound. Mass spec.: MH + =604 (FAB); α! D 25 =+34.1° (10.98 mg/2 mL, EtOH). partial 1 H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 8.15 (d, 2H); 7.58 (s, 1H); 7.26 (d, 1H); 7.15 (d, 2H); 7.03 (d, 1H); 4.57 (d, 1H). To prepare the HCl salt of the title compound of Example 14 dissolve 700 mg of the title compound in 4 mL of CH 2 Cl 2 , add 4 mL of Et 2 O, cool to 0° C. and slowly add (dropwise) 1 mL of HCl (g) in dioxane. Add 2 mL of Et 2 O and stir at 0° C. for 7 min. Dilute with 30 mL of Et 2 O, filter to collect the solid product and wash with 30 mL of Et 2 O. Dry the solids in vacuo to give 0.836 g of the HCl salt of Example 14. α! D 25 =+64.8° (9.94 mg/2 mL, EtOH). EXAMPLE 14A & 14B ##STR76## The (-)-enantiomer of the title compound of Preparative Example 10, Step B, (0.60 g) is reacted with 0.39 g of the title compound of Preparative Example 1, via substantially the same procedure as described for Example 9 to give 0.705 g of the title compound. Mass spec.: MH + =604 (FABS); α! D 25 =-41.8° (EtOH). Partial 1 H NMR (CDCl 3 , 300 MHz): 8.38 (s, 1H); 8.15 (d, 2H); 7.58 (s, 1H); 7.26 (d, 1H); 7.15 (d, 2H); 7.03 (d, 1H); 4.57 (d, 1H). The HCl salt of the title compound of Example 14A is prepared via substantially the same procedure as described for Example 14. α! D 25 =-63.2° (EtOH). The racemic title compound of Preparative Example 10, Step A, is converted to the racemic title compound of Example 14B following substantially the same procedure as described for Example 9. Partial 1 H NMR (CDCl 3 , 400 MHz): 8.38 (s, 1H); 8.15 (d, 2H); 7.58 (s, 1H); 7.26 (d, 1H); 7.15 (d, 2H); 7.03 (d, 1H); 4.57 (d, 1H). Partial 1 H NMR (DMSO-d 6 , 400 MHz): 8.77 (d, 2H); 8.47 (s, 1H); 7.95 (s, 1H); 7.74 (d, 2H); 7.43 (m, 1H); 7.27 (d, 1H); 4.35 (d, 1H). EXAMPLE 15 ##STR77## The title compound of Preparative Example 4 is reacted via substantially the same methods as described for Example 8, Steps A-C, to give the title compound, which is a racemate. Mass Spec.: MH + =635 (FAB). Partial 1 H NMR (CDCl 3 ): 8.45 (s, 1H); 7.60 (s, 1H); 7.35 (d, 1H); 7.05 (d, 1H); 4.45 (s, 1H). EXAMPLES 16A & 16B ##STR78## The R-(+)-enantiomer or the S-(-) enantiomer of the title comound of Preparative Example 11 is treated via substantially the same procedure as described for Example 2 to give the R-(+)-enantiomer of the title compound or the S-(-)-enantiomer of the title compound, Examples 16A and 16B, respectively. Physical chemical data for the R-(+)-enantiomer: 13 C NMR (CDCl 3 ): 166.5 (C); 154.8 (C); 146.6 (CH); 140.8 (CH); 140.4 (C); 138.5 (CH); 138.5 (CH); 136.3 (C); 134.6 (C); 133.8 (C); 133.6 (C); 132.0 (CH); 130.0 (CH); 126.3 (CH); 126.3 (CH); 125.8 (CH); 119.6 (C); 78.4 (CH); 51.1 (CH 2 ); 50.6 (CH 2 ); 45.4 (CH 2 ); 41.5 (CH 2 ); 38.0 (CH 2 ); 30.1 (CH 2 ); 30.0 (CH 2 ). α! D 25 =+30.7° (10.35 mg/2 mL MeOH). Physical chemical data for the S-(-)-enantiomer: 13 C NMR (CDCl 3 ): 166.5 (C); 154.8 (C); 146.6 (CH); 140.8 (CH); 140.4 (C); 138.5 (CH); 138.5 (CH); 136.3 (C); 134.6 (C); 133.8 (C); 133.6 (C); 132.0 (CH); 130.0 (CH); 126.3 (CH); 126.3 (CH); 125.8 (CH); 119.6 (C); 78.4 (CH); 51.1 (CH2); 50.6 (CH2); 45.4 (CH 2 ); 41.5 (CH 2 ); 38.0 (CH 2 ); 30.1 (CH 2 ); 29.9 (CH 2 ). α! D 25 =-30.9° (9.70 mg/2 mL MeOH). EXAMPLES 17 & 17A ##STR79## Treat the (+)-enantiomer or the (-)-enantiomer of the title compound of Preparative Example 11 via substantially the same procedure as described for Example 1, Steps A-C, to give the R-(+)-enantiomer of the title compound or the S-(-)-enantiomer of the title compound, Examples 17 and 17A, respectively. Physical chemical data for the R-(+)-enantiomer: 13 C NMR (CDCl 3 ): 169.3 (C); 157.5 (C); 155.0 (C); 146.6 (CH); 140.8 (CH); 140.4 (C); 136.3 (C); 134.8 (C); 133.7 (C); 132.0 (CH); 130.0 (CH); 125.8 (CH); 119.6 (C); 78.5 (CH); 51.4 (CH 2 ); 50.9 (CH 2 ); 45.2 (CH 2 ); 43.9 (CH 2 ); 43.9 (CH 2 ); 41.1 (CH 2 ); 38.8 (CH 2 ); 32.5 (CH); 31.5 (CH 2 ); 31.5 (CH 2 ); 30.1 (CH 2 ); 30.0 (CH 2 ). α! D 24 .8 =+28.7° (10.1 mg/2 mL MeOH). Physical chemical data for the S-(-)-enantiomer: 13 C NMR (CDCl 3 ): 169.3 (C); 157.6 (C); 155.0 (C); 146.6 (CH); 140.8 (CH); 140.4 (C); 136.3 (C); 134.8 (C); 133.7 (C); 132.0 (CH); 130.0 (CH); 125.8 (CH); 119.6 (C); 78.5 (CH); 51.4 (CH 2 ); 50.9 (CH 2 ); 45.2 (CH 2 ); 43.9 (CH 2 ); 43.9 (CH 2 ); 41.1 (CH 2 ); 38.8 (CH 2 ); 32.5 (CH); 31.5 (CH 2 ); 31.5 (CH 2 ); 30.1 (CH 2 ); 30.0 (CH 2 ). α! D 24 .8 =-28.5° (10.1 mg/2 mL MeOH). EXAMPLE 18 ##STR80## Dissolve 9.90 g (18.9 mmol) of the product of Preparative Example 7, Step B, in 150 mL CH 2 Cl 2 and 200 mL of CH 3 CN and heat to 60° C. Add 2.77 g (20.8 mmol) N-chlorosuccinimide and heat to reflux for 3 h., monitoring the reaction by TCL (30% EtOAc/H 2 O). Add an additional 2.35 g (10.4 mmol) of N-chlorosuccinimide and reflux an additional 45 min. Cool the reaction mixture to room temperature and extract with 1N NaOH and CH 2 Cl 2 . Dry the CH 2 Cl 2 layer over MgSO 4 , filter and purify by flash chromatography (1200 mL normal phase silica gel, eluting with 30% EtOAc/H 2 O) to obtain 6.24 g of the desired product. M.p. 193°-195.4° C. MH + =510. ##STR81## To 160 mL of conc. HCl at -10° C. add 2.07 g (30.1 mmol) NaNO 2 and stir for 10 min. Add 5.18 g (10.1 mmol) of the product of Step A and warm the reaction mixture from -10° C. to 0° C. for 2 h. Cool the reaction to -10° C., add 100 mL H 3 PO 2 and let stand overnight. To extract the reaction mixture, pour over crushed ice and basify with 50% NaOH/CH 2 Cl 2 . Dry the organic layer over MgSO 4 , filter and concentrate to dryness. Purify by flash chromatography (600 mL normal phase silica gel, eluting with 20% EtOAc/hexane) to obtain 3.98 g of product. Mass spec.: MH + =495. ##STR82## Dissolve 3.9 g of the product of Step B in 100 mL conc. HCl and reflux overnight. Cool the mixture, basify with 50% w/w NaOH and extract the resultant mixture with CH 2 Cl 2 . Dry the CH 2 Cl 2 layer over MgSO 4 , evaporate the solvent and dry under vacuum to obtain 3.09 g of the desired product. Mass spec.: MH + =423. ##STR83## Using a procedure similar to that described in Preparative Example 8, obtain 1.73 g of the desired product, m.p. 169.6°-170.1° C.; α! D 25 =+48.2° (c=1, MeOH). MH + =425. Step E: Use a procedure similar to that of Example 4 with the product of Step D as the starting material to obtain the title compound. M.p. 152.3°-153.3° C.; α! D 25 =+53.0° (c=1, MeOH). MH + =593. EXAMPLE 19 ##STR84## Treat 15.0 g (44.4 mmol) of the product of Preparative Example 9, Step B, with 6.52 g (48.9 mmol) of N-chloro-succinimide in a manner similar to that described in Example 18, Step A and extract as described to obtain 16.56 g of the desired product, m.p. 234.7°-235.0° C. MH + =370. ##STR85## Treat 16.95 g (45.6 mmol) of the product of Step A in the manner described in Example 18, Step B, to obtain 13.07 g of the desired product, m.p. 191.7°-192.1C. MH + =356. ##STR86## Using the procedure substantially as described in Preparative Example 9, Step E, treat 10.0 g (28.0 mmol) of the product of Step B with NaBH 4 to obtain the desired product, which is used in the next step without further purification. ##STR87## Dissolve 10.0 g (27.9 mmol) of the product of Step C in 200 mL CH 2 Cl 2 under N 2 with stirring at room temperature. Cool the reaction mixture to 0° C. and add 2.63 g of triethylamine and 4.80 g (41.9 mmol) of methanesulfonyl chloride. To the resultant solution at 0° C. add a solution of 16.84 g (19.6 mmol) piperazine and 100 mL of THF, immediately followed by 100 mL DMF. Stir overnight at room temperature. Evaporate the solvent and extract the resultant residue with CH 2 Cl 2 and sat'd NaHCO 3 . Dry the CH 2 Cl 2 layer over MgSO 4 , filter and concentrate to obtain the crude product. Chromatograph the crude product on 1200 mL silica gel, eluting with 5% CH 3 OH(sat'd with NH 3 ) in CH 2 Cl 2 to obtain a racemic mixture. Separate the racemic compound by chiral chromatography using a Chiralpack AD column (5 cm×50 cm), eluting with 30% iPrOH/hexane with 0.2% diethylamine. Mass spec.: MH + =426. The desired isomer is the (+)-enantiomer. Step E: Stir 2.0 g (4.7 mmol) of the product of Step D in 40 mL DMF under N 2 , cool the mixture to 0° and add 0.615 g (6.1 mmol) N-methylmorpholine, 1.1668 g (6.1 mmol) DEC, 0.8225 g (6.1 mmol) HOBT and 1.6042 g (6.1 mmol) of the product of Preparative Example 1. Stir overnight at room temperature. Evaporate the solvent and extract the resultant residue with CH 2 Cl 2 water, sat'd NaHCO 3 , 10% NaH 2 PO 4 and brine. Separate the CH 2 Cl 2 layer, dry over MgSO 4 , filter and concentrate to dryness. Purify the resultant residue by flash chromatography on 400 mL of normal phase silica gel, eluting with 5% CH 3 OH/NH 3 --CH 2 Cl 2 to obtain 2.43 g of the title compound, m.p. 145.3°-146.1° C.; α! D 25 =+33.6° (c=1, MeOH). MH + =561. EXAMPLE 20 ##STR88## Heat 200 mg of the cyano starting material in 17 g polyphosphoric acid at 190°-200° C. for 45 min. Pour the resultant mixture into ice, add 30% HCl and stir for 30 min. Extract with CH 2 Cl 2 , wash with brine, dry over Na 2 SO 4 , filter and concentrate. Purify by preparative TLC, eluting with EtOAc/hexane to obtain 21 mg of the desired product (also obtained 59 mg of the 1 0-chloro product). ##STR89## Using the procedure substantially as described in Preparative Example 9, Step E, treat 1.75 g (5.425 mmol) of the product of Step A with NaBH 4 to obtain the desired product. ##STR90## Dissolve the residue obtained in Step B in 50 mL CH 2 Cl 2 at room temperature, add 3.95 mL (5.425 mmol) of SOCl 2 and stir at room temperature overnight. Remove excess SOCl 2 and solvent under vacuum. Dissolve the residue in CH 2 Cl 2 , wash with sat'd NaHCO 3 and brine, dry over Na 2 SO 4 , filter and concentrate. Add 25 mL THF to the resultant residue, add 2.33 g (27.125 mmol) piperazine and stir at room temperature overnight. Evaporate the solvent, add CH 2 Cl 2 wash with sat'd NaHCO 3 and brine, dry over Na 2 SO 4 , filter and concentrate. Purify the resultant residue by chiral chromatography using a Chiralpack AD column and eluting with 20% iPrOH/hexane with 0.2% diethylamine. Mass spec.: MH + =-392. The desired isomer is the (+)-enantiomer. Step D: Combine 770 mg (1.960 mmol) of the product of Step C, 323 μl (2.548 mmol) N-methylmorpholine, 344 mg (2.548 mmol) HOBT, 487 mg (2.548 mmol) DEC and 390 mg (2.548 mmol) of the compound of Preparative Example 1 in 8 ml DMF and stir at room temperature overnight. Evaporate the solvent, add EtOAc and wash with sat'd NaHCO 3 , water and brine, and dry over Na 2 SO 4 . Purify by flash chromatography on silica gel, eluting with EtOAc to 10, 12% (10% NH 4 OH/CH 3 OH)/EtOAc gradient. Further purify by preparative TLC (1000 μ silica gel) to obtain 750 mg of the title compound, α! D 25 =+23.3° (c=0.322, MeOH). EXAMPLE 21 ##STR91## Dissolve 10.0 g (29.6mmol) of the product of Preparative Example 9, Step B, in 150 mL CH 2 Cl 2 and 200 mL CH 3 CN at room temperature. Heat the mixture to 60° C., add 10.45 g (32.6 mmol) of 1-fluoro-4-hydroxy-1,4-diazoniabicyclo 2,2,2!octane bis-(tetrafluoroborate) and heat to reflux for 4 h. Cool the mixture to room temperature, extract with CH 2 Cl 2 and 1N NaOH. Dry the CH 2 Cl 2 layer over MgSO 4 , filter and concentrate to dryness. Purify the resultant residue by flash chromatography using 1400 mL normal phase silica gel eluted with 10% EtOAc-CH 2 Cl 2 +2 drops NH 4 OH to obtain 2.00 g of product, m.p. 103.2°-103.5° C. M + =355. ##STR92## Using a procedure substantially as described in Preparative Example 9, Step D, treat 1.80 g (5.1 mmol) of the product of Step A. Purify the crude product by flash chromatography using 200 mL normal phase silica gel eluted with 20% EtOAc/hexane. Mass spec.: MH + =339. ##STR93## Using the procedure substantially as described in Preparative Example 9, Step E, treat 0.47 g (1.4 mmol) of the product of Step B with NaBH 4 to obtain the desired product. Mass spec.: MH + =342. ##STR94## Dissolve 0.37 g (1.1 mmol) of the product of Step C in 20 mL toluene under N 2 and cool from room temperature to 0° C. Add 0.3855 g (3.2 mmol) of SOCl 2 and stir at room temperature, then add 10 mL CHCl 3 and stir for 3 h. Evaporate the solvent, extract the resultant residue with 1N NaOH-CH 2 Cl 2 , dry the CH 2 Cl 2 layer over MgSO 4 , filter and concentrate to dryness. Dissolve the residue in 10 mL THF under N 2 , add 0.465 g (5.4 mmol) of piperazine, 10 mL THF and stir overnight at room temperature. Repeat the extraction procedure to obtain the desired product. Mass spec.: MH + =410. Step E: Treat 0.44 g (1 .1 mmol) of the product of Step D with N-methylmorpholine, 4-pyridylacetic acid N-oxide, DEC and HOBT in DMF as described in Example 5. Evaporate the solvent and extract the resultant residue with CH 2 Cl 2 -H 2 O, sat'd NaHCO 3 , 10% NaH 2 PO 4 and brine. Dry the CH 2 Cl 2 layer over MgSO 4 , filter and concentrate to dryness. Purify the resultant residue by flash chromatography on 150 mL normal phase silica gel, eluting with 5% CH 3 OH/NH 3 -CH 2 Cl 2 to obtain 0.41 g of the title compound, m.p. 155.0°-155.6° C.; Mass spec.: MH + =545. Using appropriate starting materials and procedures as described above, the following compounds could be made: ##STR95## ASSAYS 1. In vitro enzyme assays: Inhibition of farnesyl protein transferase and geranylgeranyl protein transferase. Both farnesyl protein transferase (FPT) and geranylgeranyl protein transferase (GGPT) I were partially purified from rat brain by ammonium sulfate fractionation followed by Q-Sepharose (Pharmacia, Inc.) anion exchange chromatography essentially as described by Yokoyama et al (Yokoyama, K., et al., (1991), A protein geranylgeranyltransferase from bovine brain: Implications for protein prenylation specificity, Proc. Natl. Acad. Sci USA 88: 5302-5306, the disclosure of which is incorporated herein by reference thereto). Human farnesyl protein transferase was also expressed in E. coli, using cDNA clones encoding both the a and b subunits. The methods used were similar to those published (Omer, C. et al., (1993), Characterization of recombinant human farnesyl protein transferase: Cloning, expression, farnesyl diphosphate binding, and functional homology with yeast prenyl-protein transferases, Biochemistry 32:5167-5176). Human farnesyl protein transferase was partially-purified from the soluble protein fraction of E. coli as described above. The tricyclic farnesyl protein transferase inhibitors disclosed herein inhibited both human and rat enzyme with similar potencies. Two forms of val 12 -Ha-Ras protein were prepared as substrates for these enzymes, differing in their carboxy terminal sequence. One form terminated in cysteine-valine-leucine-serine (Ras-CVLS) the other in cystein-valine-leucine-leucine (Ras-CVLL). Ras-CVLS is a substrate for the farnesyl protein transferase while Ras-CVLL is a substrate for geranylgeranyl protein transferase I. The cDNAs encoding these proteins were constructed so that the proteins contain an amino-terminal extension of 6 histidine residues. Both proteins were expressed in Escherichia coli and purified using metal chelate affinity chromatography. The radiolabelled isoprenyl pyrophosphate substrates, 3 H!farnesyl pyrophosphate and 3 H! geranylgeranyl pyrophosphate, were purchased from DuPont/New England Nuclear. Several methods for measuring farnesyl protein transferase activity have been described (Reiss et al 1990, Cell 62:81; Schaber et al 1990, J. Biol. Chem. 265:14701; Manne et al 1990, PNAS 87:7541; and Barbacid & Manne 1993, U.S. Pat. No. 5,185,248). The activity was assayed by measuring the transfer of 3 H!farnesyl from 3 H!farnesyl pyrophosphate to Ras-CVLS using conditions similar to those described by Reiss et al. 1990 (Cell 62:81) The reaction mixture contained 40 mM Hepes, pH 7.5; 20 mM magnesium chloride; 5 mM dithiothreitol; 0.25 μM 3 H!farnesyl pyrophosphate; 10 ml Q-Sepharose-purified farnesyl protein transferase; the indicated concentration of tricyclic compound or dimethylsulfoxide (DMSO) vehicle control (5% DMSO final); and 5 mM Ras-CVLS in a total volume of 100 ml. The reaction was allowed to proceed for 30 minutes at room temperature and then stopped with 0.5 ml of 4% sodium dodecyl sulfate (SDS) followed by 0.5 ml of cold 30% TCA. Samples were allowed to sit on ice for 45 minutes and precipitated Ras protein was then collected on GF/C filter paper mats using a Brandel cell harvester. Filter mats were washed once with 6% TCA, 2% SDS and radioactivity was measured in a Wallac 1204 Betaplate BS liquid scintillation counter. Percent inhibition was calculated relative to the DMSO vehicle control. The geranylgeranyl protein transferase I assay was essentially identical to the farnesyl protein transferase assay described above, with two exceptions: 3H!geranylgeranylpyrophosphate replaced farnesyl pyrophosphate as the isoprenoid donor and Ras-CVLL was the protein acceptor. This is similar to the assay reported by Casey et al (Casey, P. J., et al., (1991), Enzymatic modification of proteins with a geranylgeranyl isoprenoid, Proc. Natl. Acad. Sci, USA 88:8631-8635, the disclosure of which is incorporated herein by reference thereto). 2. Cell-Based Assay: Transient expression of val 12 -Ha-Ras-CVLS and val 2 -Ha-Ras-CVLL in COS monkey kidney cells: Effect of farnesyl protein transferase inhibitors on Ras processing and on disordered cell growth induced by transforming Ras. COS monkey kidney cells were transfected by electroporation with the plasmid pSV-SPORT (Gibco/BRL) containing a cDNA insert encoding either Ras-CVLS or Ras-CVLL, leading to transient overexpression of a Ras substrate for either farnesyl protein transferase or geranylgeranyl protein transferase I, respectively (see above). Following electroporation, cells were plated into 6-well tissue culture dishes containing 1.5 ml of Dulbecco's-modified Eagle's media (GIBCO, Inc.) supplemented with 10% fetal calf serum and the appropriate farnesyl protein transferase inhibitors. After 24 hours, media was removed and fresh media containing the appropriate drugs was re-added. 48 hours after electroporation cells were examined under the microscope to monitor disordered cell growth induced by transforming Ras. Cells expressing transforming Ras become more rounded and refractile and overgrow the monolayer, reminiscent of the transformed phenotype. Cells were then photographed, washed twice with 1 ml of cold phosphate-buffered saline (PBS) and removed from the dish by scraping with a rubber policeman into 1 ml of a buffer containing 25 mM Tris, pH 8.0; 1 mM ethylenediamine tetraacetic acid; 1 mM phenylmethylsulfonyl fluoride; 50 mM leupeptin; and 0.1 mM pepstatin. Cells were lysed by homogenization and cell debris was removed by centrifugation at 2000× g for 10 min. Cellular protein was precipitated by addition of ice-cold trichloroacetic acid and redissolved in 100 ml of SDS-electrophoresis sample buffer. Samples (5-10 ml) were loaded onto 14% polyacrylamide minigels (Novex, Inc.) and electrophoresed until the tracking dye neared the bottom of the gel. Proteins resolved on the gels were electroblotted onto nitrocellulose membranes for immunodetection. Membranes were blocked by incubation overnight at 4° C. in PBS containing 2.5% dried milk and 0.5% Tween-20 and then incubated with a Ras-specific monoclonal antibody, Y13-259 (Furth, M. E., et al., (1982), Monoclonal antibodies to the p21 products of the transforming gene of Harvey murine sarcome virus and of the cellular ras gene family, J. Virol. 43:294-304), in PBS containing 1% fetal calf serum for one hour at room temperature. After washing, membranes were incubated for one hour at room temperature with a 1:5000 dilution of secondary antibody, rabbit anti-rat lgG conjugated to horseradish peroxidase, in PBS containing 1% fetal calf serum. The presence of processed and unprocessed Ras-CVLS or Ras-CVLL was detected using a colorimetric peroxidase reagent (4-chloro-1-naphthol) as described by the manufacturer (Bio-Rad). 3. Cell Mat Assay: Normal human HEPM fibroblasts were planted in 3.5 cm dishes at a density of 5×10 4 cells/dish in 2 ml growth medium, and incubated for 3-5 d to achieve confluence. Medium was aspirated from each dish and the indicator tumor cells, T24-BAG4 human bladder carcinoma cells expressing an activated H-ras gene, were planted on top of the fibroblast monolayer at a density of 2×10 3 cells/dish in 2 ml growth medium, and allowed to attach overnight. Compound-induced colony inhibition was assayed by addition of serial dilutions of compound directly to the growth medium 24 h after tumor cell planting, and incubating cells for an additional 14 d to allow colony formation. Assays were terminated by rinsing monolayers twice with phosphate-buffered saline (PBS), fixing the monolayers with a 1% glutaraldehyde solution in PBS, then visualizing tumor cells by staining with X-Gal (Price, J., et al., Lineage analysis in the vertebrate nervous system by retrovirus-mediated gene transfer, Proc. Natl. Acad. Sci.84, 156-160(1987)). In the colony inhibition assay, compounds were evaluated on the basis of two IC 50 values: the concentration of drug required to prevent the increase in tumor cell number by 50% (tIC 50 ) and the concentration of drug required to reduce the density of cells comprising the cell mat by 50% (mIC 50 ). Both IC 50 values were obtained by determining the density of tumor cells and mat cells by visual inspection and enumeration of cells per colony and the number of colonies under the microscope. The therapeutic index of the compound was quantitatively expressed as the ratio of mIC 50 /tIC 50 , with values greater than one indicative of tumor target specificity. Additional assays were carried out by following essentially the same procedure as described above, but with substitution of alternative indicator tumor cell lines in place of the T24-BAG cells. The assays were conducted using either DLD-1-BAG human colon carcinoma cells expressing as activated K-ras gene or SW620-BAG human colon carcinoma cells expressing an activated K-ras gene. Using other tumor cell lines known in the art, the activity of the compounds of this invention against other types of cancer cells (such as those listed herein on pages 15 and 16) can be demonstrated. 4. Soft Agar Assay: Anchorage-independent growth is a characteristic of tumorigenic cell lines. Human tumor cells are suspended in growth medium containing 0.3% agarose and an indicated concentration of a farnesyl transferase inhibitor. The solution is overlayed onto growth medium solidified with 0.6% agarose containing the same concentration of farnesyl transferase inhibitor as the top layer. After the top layer is solidified, plates are incubated for 10-16 days at 37° C. under 5% CO 2 to allow colony outgrowth. After incubation, the colonies are stained by overlaying the agar with a solution of MTT (3- 4,5-dimethylthiazol-2-yl!-2,5-diphenyltetrazolium bromide, Thiazolyl blue) (1 mg/mL in PBS). Colonies are counted and the IC 50's determined. TABLE 1______________________________________FPT INHIBITION FPT IC.sub.50 FPT IC.sub.50EXAMPLE (μM) EXAMPLE (μM)______________________________________1 <0.034 2 0.010 0.0164 0.046 16A 0.032 0.02616B 0.038 11B >0.095 0.02315 0.022 7 0.0128 0.021 11A 0.0018 0.00215 0.0023 12B 0.00259 0.0013 10 0.0019 7B <0.003 8B 0.01314A 0.0026 14 0.06213A 0.078 13 0.005 5A >0.099 7A >0.1 8A >0.094 10A >0.094 9A >0.088 6 0.003111 0.002 5B ˜0.00312A >0.094 13B 0.00514B 0.005 5 · HCl salt 0.003814A · HCl salt <0.0031 9B 0.00310B 0.003 17 0.04317A 0.048 18 0.003119 <0.0038 20 0.006221 0.0084______________________________________ TABLE 2______________________________________COMPARISON OF FPT INHIBITION AND GGPT INHIBITION ENZYME ENZYME INHIBITION INHIBITIONEXAMPLE FPT IC.sub.50 μM GGPT IC.sub.50 μM______________________________________2 0.010 >300 0.0164 0.046 >35.7 5B ˜0.003 >30016A 0.032 >38 0.02616B 0.038 >76 0.0237 0.012 >30011A 0.0018 >66 0.00219 0.0013 >595 0.0023 >6614A 0.0026 >6213 0.005 >63 7B <0.003 >66 8B 0.013 >6018 0.0031 >5020 0.0062 >38______________________________________ TABLE 3______________________________________ACTVITY IN COS CELLS Inhibition of Inhibition of Ras Ras Processing ProcessingExample IC.sub.50 (μM) Example IC.sub.50 (μM)______________________________________8 <0.25 2 0.2515 0.60 16A 0.516B 0.125 11 <0.257 <0.25 5B 0.0510 <0.025 10A 2.012B <0.025 12A 0.9511A <0.025 11B 2.255 0.098 14A · HCl salt 0.01513 0.420 9 0.010 7B 0.025 8B 0.280 9A 0.85 5 · HCl salt 0.010 5A 5.0 14A 0.480 1.014 >1.0 13A >1.0 7A >1.0 8A >1.017 0.350 17A 0.50014B 0.045 6 0.04018 0.025 19 0.04520 ˜0.030 21 0.42______________________________________ TABLE 4______________________________________INHIBITION OF TUMOR CELL GROWTH - MAT ASSAY Tumor Tumor Tumor Normal (T-24) (DLD-1) (SW620) IC.sub.50Example IC.sub.50 (μM) IC.sub.50 (μM) IC.sub.50 (μM) (μM)______________________________________1 <1.6 -- -- >254 3.1 -- -- >257 <1.6 <1.6 6.25 >25 5B <1.6 3.1 10 >2513B <1.6 3.1 >3.1 2511B <1.6 8 18 >25 9A <1.6 12.5 12.5 1810A <1.6 2.0 1.6 85 <1.6 3.1 6.25 >2514A <1.6 6.25 12.5 >2513A 3.1 6.25 6.25 >25 7B <1.6 1.6 3.1 >25 8A <1.6 <1.6 3.1 >252 <1.6 6.25 6.25 >2516B <1.6 6.25 25 >258 <1.6 3.1 3.1 >2515 3.1 6.25 >6.25 >2511A <1.6 <1.6 >6.25 >259 <1.6 <1.6 6.25 >2510 <1.6 <1.6 3.1 >2512A <1.6 2.0 4 >25 5A 12.5 12.5 >25 >2514 <1.6 6.25 >12.5 >2513 <1.6 3.1 >1.6 >25 8B <1.6 <1.6 3.1 >2517 1.6 6.25 25 >2517A 3.1 4 18 >2510B <1.6 1.6 1.6 >2512B <1.6 3.1 6.25 >25 7A <1.6 1.6 3.1 >256 <1.6 4.0 6.24 --19 <1.6 <1.6 6.25 >25______________________________________ TABLE 5______________________________________INHIBITION OF HUMAN TUMOR CELL GR0WTH -SOFT AGAR ASSAY IC.sub.50 (μM)Tumor Cell Line Example 10 Example 18______________________________________K ras NIH 3T3 0.40 0.8H ras NIH 3T3 0.075 0.175HTB 177 0.04 0.2(NSCLC) K ras mutationHTB 173 (NCI H146) 0.05 --(SCLC) ras mut. not detectedA549 0.150 0.3(lung) K ras mutationHTB 175 0.250 0.6(SCLC) ras mut. not detectedHTB 119 (NCI H69) 0.3 --(SCLC)HTB 183 (NCI H661) 0.5 --(NSCLC) ras mut. not detectedHPAF II <0.5 --(pancreatic) K ras mutationMCF-7 <0.6 --(breast) ras mut. not detectedHBL100 <0.6 --(breast) ras mut. not detectedDu4475 0.6 --(breast) ras mut. not detectedMDA MB 468 0.6 --(breast) ras mut. not detectedDU 145 0.6 --(prostate) ras mut. not detectedMDA MB453 (breast) 0.6 --BT474 (breast) 1.0 --PC3 (prostate) 1.25 --DLD 1 2.5 --(colon) K ras mutationAsPc-1 3.0 --(pancreatic) K ras mutation______________________________________ Determined ras mutation status by ELISA (Oncogene Science) RESULTS 1. Enzymology: The data demonstrate that the compounds of the invention are inhibitors of Ras-CVLS farnesylation by partially purified rat brain farnesyl protein transferase (FPT). The data also show that there are compounds of the invention which can be considered as very potent (IC 50 <<0.1 μM) inhibitors of Ras-CVLS farnesylation by partially purified rat brain FPT. The data also demonstrate that compounds of the invention are poorer inhibitors of geranylgeranyl protein transferase (GGPT) assayed using Ras-CVLL as isoprenoid acceptor. This selectivity is important for the therapeutic potential of the compounds used in the methods of this invention, and increases the potential that the compounds will have selective growth inhibitory properties against Ras-transformed cells. 2. Cell-Based: COS Cell Assay Western blot analysis of the Ras protein expressed in Ras-transfected COS cells following treatment with the tricyclic farnesyl protein transferase inhibitors of this invention indicated that they inhibit Ras-CVLS processing, causing accumulation of unprocessed Ras (see Table 3). The compound of Example 2, for example, inhibited Ras-CVLS processing with an IC 50 value of 0.025 μM, but did not block the geranylgeranylation of Ras-CVLL at concentrations up to 33 μM. These results provide evidence for specific inhibition of farnesyl protein transferase, but not geranylgeranyl transferase I, by compounds of this invention in intact cells and indicate their potential to block cellular transformation by activated Ras oncogenes. 3. Cell-Based: Cell Mat Assay Tricyclic farnesyl protein transferase inhibitors of this invention also inhibited the growth of Ras-transformed tumor cells in the Mat assay without displaying cytotoxic activity against the normal monolayer. In Vivo Anti-Tumor Studies: Tumor cells (5×10 5 to 8×10 6 ) of DLD-1 (human colon carcinoma cells, ATCC♯ CCL 221) are innolculated subcutaneously into the flank of 5-6 week o;d athymic nu/nu female mice. Tumor bearing animals are selected and randomized when the tumors are established. Animals are treated with vehicle (β-cyclodextrin for i.p. or corn oil for p.o.) only or with a compound of the present invention in vehicle four times a day (QID) for 7 days per week for 4 weeks. The percent inhibition of tumor growth relative to vehicle controls is determined by tumor measurements. The results are reported in Table 6. TABLE 6______________________________________IN VIVO ANTI-TUMOR STUDIES Average % Experiment Dose TumorExample No. (mg/kg) Inhibition______________________________________16B 1 50 p.o. 77 2 10 p.o. 504 1 50 p.o. 41 2 10 p.o. 18 3 50 p.o. 41 4 10 p.o. 142 1 50 p.o. 47 2 10 p.o. 25 3 50 p.o. 52.66 4 10 p.o. 31.941 1 50 p.o. 38.2 2 10 p.o. 17.16 3 50 p.o. 35.4 4 10 p.o. 34.07 1 50 p.o. 76.5 2 10 p.o. 35.111A 1 50 p.o. 63.8 2 10 p.o. 44.811B 1 50 p.o. 38.8 2 10 p.o. 17.09 1 50 p.o. 68 2 10 p.o. 1910 1 50 p.o. 77 2 10 p.o. 495 1 50 p.o. 38 2 10 p.o. 2414A 1 50 p.o. 59 2 10 p.o. 4813 1 50 p.o. 61 2 10 p.o. 712B 1 50 p.o. 83 2 10 p.o. 37.75 1 50 p.o. 38 2 10 p.o. 24 7A 1 50 p.o. 55.1 2 10 p.o. 33.7 8B 1 50 p.o. 62.5 2 10 p.o. 29.26 1 50 p.o. 61.2 2 10 p.o. 35.418 1 50 p.o. 73 2 10 p.o. 43______________________________________ For preparing pharmaceutical compositions from the compounds described by this invention, inert, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets and suppositories. The powders and tablets may be comprised of from about 5 to about 70 percent active ingredient. Suitable solid carriers are known in the art, e.g. magnesium carbonate, magnesium stearate, talc, sugar, lactose. Tablets, powders, cachets and capsules can be used as solid dosage forms suitable for oral administration. For preparing suppositories, a low melting wax such as a mixture of fatty acid glycerides or cocoa butter is first melted, and the active ingredient is dispersed homogeneously therein as by stirring. The molten homogeneous mixture is then poured into convenient sized molds, allowed to cool and thereby solidify. Liquid form preparations include solutions, suspensions and emulsions. As an example may be mentioned water or water-propylene glycol solutions for parenteral injection. Liquid form preparations may also include solutions for intranasal administration. Aerosol preparations suitable for inhalation may include solutions and solids in powder form, which may be in combination with a pharmaceutically acceptable carrier, such as an inert compressed gas. Also included are solid form preparations which are intended to be converted, shortly before use, to liquid form preparations for either oral or parenteral administration. Such liquid forms include solutions, suspensions and emulsions. The compounds of the invention may also be deliverable transdermally. The transdermal compositions can take the form of creams, lotions, aerosols and/or emulsions and can be included in a transdermal patch of the matrix or reservoir type as are conventional in the art for this purpose. Preferably the compound is administered orally. Preferably, the pharmaceutical preparation is in unit dosage form. In such form, the preparation is subdivided into unit doses containing appropriate quantities of the active component, e.g., an effective amount to achieve the desired purpose. The quantity of active compound in a unit dose of preparation may be varied or adjusted from about 0.1 mg to 1000 mg, more preferably from about 1 mg. to 300 mg, according to the particular application. The actual dosage employed may be varied depending upon the requirements of the patient and the severity of the condition being treated. Determination of the proper dosage for a particular situation is within the skill of the art. Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is reached. For convenience, the total daily dosage may be divided and administered in portions during the day if desired. The amount and frequency of administration of the compounds of the invention and the pharmaceutically acceptable salts thereof will be regulated according to the judgment of the attending clinician considering such factors as age, condition and size of the patient as well as severity of the symptoms being treated. A typical recommended dosage regimen is oral administration of from 10 mg to 2000 mg/day preferably 10 to 1000 mg/day, in two to four divided doses to block tumor growth. The compounds are non-toxic when administered within this dosage range. The following are examples of pharmaceutical dosage forms which contain a compound of the invention. The scope of the invention in its pharmaceutical composition aspect is not to be limited by the examples provided. Pharmaceutical Dosage Form Examples EXAMPLE A Tablets ______________________________________No. Ingredients mg/tablet mg/tablet______________________________________1. Active compound 100 5002. Lactose USP 122 1133. Corn Starch, Food Grade, 30 40 as a 10% paste in Purified Water4. Corn Starch, Food Grade 45 405. Magnesium Stearate 3 7 Total 300 700______________________________________ Method of Manufacture Mix Item Nos. 1 and 2 in a suitable mixer for 10-15 minutes. Granulate the mixture with Item No. 3. Mill the damp granules through a coarse screen (e.g., 1/4", 0.63 cm) if necessary. Dry the damp granules. Screen the dried granules if necessary and mix with Item No. 4 and mix for 10-15 minutes. Add Item No. 5 and mix for 1-3 minutes. Compress the mixture to appropriate size and weigh on a suitable tablet machine. EXAMPLE B Capsules ______________________________________No. Ingredient mg/capsule mg/capsule______________________________________1. Active compound 100 5002. Lactose USP 106 1233. Corn Starch, Food Grade 40 704. Magnesium Stearate NF 7 7 Total 253 700______________________________________ Method of Manufacture Mix Item Nos. 1, 2 and 3 in a suitable blender for 10-15 minutes. Add Item No. 4 and mix for 1-3 minutes. Fill the mixture into suitable two-piece hard gelatin capsules on a suitable encapsulating machine. While the present invention has been described in conjunction with the specific embodiments set forth above, many alternatives, modifications and variations thereof will be apparent to those of ordinary skill in the art. All such alternatives, modifications and variations are intended to fall within the spirit and scope of the present invention.

"Novel compounds, such as: ##STR1## are disclosed. Also disclosed are methods for inhibiting the abnormal growth of cells, for inhibiting farnesyl protein transferase and for treating cancers using the novel compounds."

[0001] This is a Continuation-in-Part of U.S. application Ser. No. 10/753,621, filed Jan. 8, 2004, which is a Divisional Application of U.S. application Ser. No. 09/879,252, filed Jun. 12, 2001 (which issued as U.S. Pat. No. 6,703,838), which is Continuation-in-Part of U.S. application Ser. No. 09/610,573 filed on Jul. 5, 2000, which is a Divisional Application of U.S. application Ser. No. 09/290,156 filed on Apr. 12, 1999, which claimed priority of a provisional U.S. Application Ser. No. 60/081,653, filed on Apr. 13, 1998 and entitled “ELECTROMAGNETIC INDUCTION METHOD AND APPARATUS FOR THE MEASUREMENT OF THE ELECTRICAL RESISTIVITY OF ROCK FORMATIONS BETWEEN DRILL HOLES CASED WITH STEEL.” FIELD OF THE INVENTION [0002] The present invention relates generally to well logging techniques using electromagnetic measurements. More particularly, the invention relates to electromagnetic induction surveys between boreholes, at least one of which includes a conductive liner. The survey method of the present invention preferably provides a measurement, estimation, or determination of subsurface formation properties such as electrical resistivity using electromagnetic induction surveys and involving a borehole lined with a conductive tubular or casing. A system for implementing such surveying methods may be referred to herein as an electromagnetic induction survey system or a electromagnetic tomography system. BACKGROUND OF THE INVENTION [0003] Geological formations forming a reservoir for the accumulation of hydrocarbons in the subsurface of the earth contain a network of interconnected paths in which fluids are disposed that may ingress or egress from the reservoir. To determine the behavior of the fluids in this network, knowledge of both the porosity and permeability of the geological formations is desired. From this information, efficient development and management of hydrocarbon reservoirs may be achieved. For example, the resistivity of geological formations is a function of both porosity and permeability. Considering that hydrocarbons are electrically insulative and most water contain salts, which are highly conductive, resistivity measurements are a valuable tool in determining the presence of hydrocarbon reservoir in the formations. [0004] To that end, there have been many prior art attempts to model geological formations. In two articles, “Crosshole Electromagnetic Tomography: A New Technology for Oil Field Characterization,” The Leading Edge, March 1995, by Wilt et al. and “Crosshole Electromagnetic Tomography: System Design Considerations and Field Results,” Society of Exploration Geophysics, Vol. 60, No. 3 1995, by Wilt et al., measurement of geological formation resistivity is described employing a low frequency electromagnetic system. [0005] FIG. 1 shows typical equipment used in the measurement of geological formation 10 resistivity between two drill holes 12 a and 12 b using electromagnetic induction. A transmitter T is located in one borehole, while a receiver R is placed in another borehole. The transmitter T typically consists of a coil (not shown) having a multi-turn loop (which consists of N T turns of wire) wrapped around a magnetically permeable core (mu-metal or ferrite) with a cross section, A T . The transmitter T may further comprise a capacitor (not shown) for tuning the frequency of the coil. When an alternating current, I T , at a frequency of f 0 Hz passes through this multi-turn loop, a time varying magnetic moment, M T , is produced in the transmitter T. This magnetic moment is defined as follows: M T =N T I T A T   (1) [0006] The magnetic moment M T can be detected by the receiver R as a magnetic field, B R . The transmitter T, receiver R, or both are typically disposed in boreholes (e.g., 12 a and 12 b ) in the earth formation 10 . In this case, the detected magnetic field, B R , is proportional to the magnetic moment of the transmitter, M T , and to a geological factor, k f , and a geometric factor b. In a rectangular coordinate system with the dipole moment M T in the x direction the field of a dc dipole ( or a low frequency dipole in free space is given by; B _ = μ 0 ⁢ M T 4 ⁢   ⁢ π ⁢   ⁢ r 3 [ x 2 r 2 ⁢ u _ x + x ⁢   ⁢ y r 2 ⁢ u _ y + y ⁢   ⁢ z r 2 ⁢ u _ z ] ( 2 ⁢ a ) [0007] where the {overscore (u)} are unit vectors in the x, y, and z directions. As the frequency increases when the dipole is in a conductive formation the above magnetic response is modified by the induced currents in the formation by a factor which is called here the formation factor k f . In a short form, the response may be written as B R =bk f M T   (2b) [0008] The geological factor, k f , is a function of the electrical conductivity distribution of the geological formation between the transmitter and the receiver. The factor b is a function of the spatial location and orientation of the field component of the magnetic field, B R , with respect to the magnetic moment of the transmitter, M T . [0009] The receiver R typically includes one or more antennas (not shown). Each antenna includes a multi-turn loop of wire wound around a core of magnetically permeable metal or ferrite. The changing magnetic field sensed by the receiver R creates an induced voltage in the receiver coil (not shown). This induced voltage (V R ) is a function of the detected magnetic field (B R ), the frequency (f 0 ), the number of turns (N R ) of wire in the receiver coil, the effective cross-sectional area of the coil (A R ), and the effective permeability (ρ R ) of the coil. Thus, V R can be defined as follows: V R =πf 0 B R N R A R ρ R   (3) [0010] While f 0 and N R are known, the product, A R ρ R , is difficult to calculate. In practice, these constants may be grouped together as k R and equation (3) may be simplified as: V R =k R B R   (4) where k R =πf 0 N R A R ρ R . [0011] Thus, instead of determining the product A R ρ R , it is more convenient to determine k R according to the following procedures. First, the receiver coil is calibrated in a known field, at a known frequency. Then, the exact value for k R is derived from the magnetic field (B R ) and the measured voltage (V R ) according to the following equation: k R =B R /V R   (5) [0012] When this system is placed in a conducting geological formation, the time-varying magnetic field, B R , which is produced by the transmitter magnetic moment M T , produces a voltage in the geological formation, which in turn drives a current therein, L 1 . The current, L 1 , is proportional to the conductivity of the geological formation and is generally concentric about the longitudinal axis of the borehole. The magnetic field proximate to the borehole results from a free space field, called the primary magnetic field, while the field resulting from current L 1 is called the secondary magnetic field. [0013] The current, L 1 , is typically out of phase with respect to the transmitter current, I T . At very low frequencies, where the inductive reactance is small, the current, L 1 , is proportional to dB/dt and is 90° out of phase with respect to I T . As the frequency increases, the inductive reactance increases and the phase of the induced current, L 1 , increases to greater than 90°. The secondary magnetic field induced by current L 1 also has a phase shift relative to the induced current L 1 and so the total magnetic field as detected by receiver R is complex. [0014] The complex magnetic field detected by receiver R may be separated into two components: a real component, B R , which is in-phase with the transmitter current, I T , and an imaginary (or quadrature) component, B I , which is phase-shifted by 90°. The values of the real component, B R , and the quadrature component, B I , of the magnetic field at a given frequency and geometrical configuration uniquely specify the electrical resistivity of a homogeneous formation pierced by the drill holes. In an inhomogeneous geological formation, however, the complex field is measured at a succession of points along the longitudinal axis of the receiver borehole for each of a succession of transmitter locations. The multiplicity of measurements thus obtained can then be used to determine the inhomogeneous resistivity distribution between the holes. [0015] In both cases, i.e., measuring homogeneous geological formation resistivity or measuring inhomogeneous geological formation resistivity, the measurements are typically made before extraction of hydrocarbons takes place. This is because the boreholes typically are cased with conductive liners (e.g., metallic casing; see 16 a and 16 b in FIG. 1 ) in order to preserve the physical integrity of the borehole during hydrocarbon extraction. The conductive tubular liners interfere with resistivity measurements and are difficult and costly to remove from the borehole once they are installed. As a result, prior art systems such as that shown in FIG. 1 are not suitable for analyzing hydrocarbon reservoirs once extraction of the hydrocarbons begins. [0016] The problems presented by conductive liners ( 16 a and 16 b in FIG. 1 ) are described by Augustin et al., in “A Theoretical Study of Surface-to-Borehole Electromagnetic Logging in Cased Holes,” Geophysics, Vol. 54, No. 1 (1989); Uchida et al., in “Effect of a Steel Casing on Crosshole EM Measurements,” SEG Annual Meeting, Texas (1991); and Wu et al., in “Influence of Steel Casing on Electromagnetic Signals,” Geophysics, Vol. 59, No. 3 (1994). These prior art references show that coupling between a transmitter and a conductive liner is independent of the surrounding geological formation conductivity for a wide range of practical formation resistivities encountered in the field. The references show further that the magnetic field produced inside the conductive liner at a distance of a few meters or less from the transmitter depends only on the conductive liner properties and not on the formation properties. [0017] The net or effective moment, M eff , of a transmitter inside a conductive liner is dictated by the inductive coupling between the transmitter and the conductive liner. Physically, the resistivity of the conductive liner is very low and the inductance relatively high. This property results in a current of almost the same magnitude as that of the transmitter current being induced in the conductive liner. Lenz's Law predicts that the magnetic field generated by this induced current in the conductive liner will oppose the time-varying magnetic field produced by the transmitter current. Thus, the magnetic field generated by the transmitter is mostly cancelled out by the magnetic field generated by the conductive liner. As a result, the magnetic field external to the conductive liner is greatly reduced, and its magnitude is proportional to the difference in currents in the transmitter and the conductive liner. In effect, the conductive liner “shields” the transmitter from any receiver positioned outside of the conductive liner. This is sometimes referred to herein as the “casing effect” on the measurement of the external magnetic field. The effective moment, the moment seen by a receiver outside the casing, is conveniently expressed by: M eff =k c M T   (6) where k c is the casing attenuation factor. [0018] An analogous situation is present with respect to a receiver if it is surrounded by a conductive liner, and the situation is exacerbated if both the transmitter and the receiver are surrounded by conductive liners. [0019] To overcome the shielding problem (the “casing effect” or “casing attenuation effects”), various techniques have been suggested. For example, U.S. Pat. No. 5,646,533, entitled “Induction Measurement in the Presence of Metallic, Magnetic Walls” and issued to Locatelli, et al., discloses a method of magnetically saturating the metallic wall to overcome this problem. Alternatively, gapped casing has been used to achieve a similar effect. Another approach is to determine the conductive liner properties (e.g., radius, thickness, conductivity, and permeability) and then compensate for these properties. However, the correction needed to compensate for the conductive liner properties may be several orders of magnitude larger than the magnetic field sensed by the receiver outside the casing. Any inaccurate correction for the conductive liner properties would have an enormous impact on the accuracy of the “corrected field.” Furthermore, conductive liners often are not homogeneous (e.g., due to variation in thickness, corrosion, or rust formation); such variations may further compromise the accuracy of the “corrected field.” [0020] Before providing more detailed description of this preferred or improved method, it may be helpful to elaborate further on crosshole electromagnetic surveys in general. [0021] In addition to frequency, other important survey parameters include the length of the data profiles and the spacing between receiver points. These parameters determine the duration of the field survey as well as the resolution of the images. Ideally, individual data profiles should be twice as long as the borehole separation and the spacing between receiver data points should be about five percent (5%) of the well separation. For example, where the boreholes are spaced 200 meters apart, the profiles should be 400 meters long (along the axial length of the borehole) with a receiver 24 , FIG. 2 , spaced every 10 meters in each of the boreholes. Note that data are collected continuously as the transmitter moves in one of the boreholes, so the physical spacing between transmitter readings is much closer than spacing between the transmitter 20 and receiver 24 . [0022] Sometimes the imaging target lies within a restricted depth interval. For example, a particular oil sand undergoing water flooding. In this case the tomography can be substantially focused on this interval and the profile length reduced. It is recommended that a profile length equal to the distance between wells and a receiver spacing of five percent (5%) of the borehole spacing in the region of interest, but ten (10%) above or below these depths. The resulting image will provide good detail in the region of interest but less above or below. [0023] Additionally, there are often physical restrictions on a survey. For example, imaging boreholes are frequently completed to the depth of the primary hydrocarbon bearing zone. It is useful, however, to extend the measurements to below this interval, but this is not possible if existing wells are utilized. The output of images taken under these less than ideal conditions is not always predictable. Usually the resolution is somewhat reduced as compared to full coverage data, but often the data are sufficient for resolving large-scale structures. In addition, these data are often still quite valuable for process monitoring applications, such as in water or steam floods. [0024] During operation, receiver 24 is positioned at various fixed depths within the borehole 12 b, while transmitter 20 is pulled up continuously at a constant rate, vice versa. Therefore, for every position of receiver 24 , there are measurements made at a plurality of positions of transmitter 20 , defining a run of data. A plurality of runs of data is taken, with receiver 24 positions at different depths for each run. In this manner, one complete set of tomography data within the depth range of interest is achieved. Usually, the intervals between different positions of receiver 24 are about 5% of the distance between the boreholes. Receiver 24 may be first moved by twice this interval at a plurality of positions. After the desired region has been measured, receiver 24 is moved back to acquire the data at points equal-distance from adjacent positions of the aforementioned plurality of positions. [0025] During data acquisition, procedures should be undertaken to ensure high quality measurements. To that end, initial tests may include the magnetic fields generated and sensed by system 19 with both transmitter 20 and receiver 24 suspended in the air above the boreholes. This facilitates determining the primary magnetic field without the effect of the earth. [0026] In addition, a linearity test may be conducted after transmitter 20 and receiver 24 have been lowered in their respective borehole. A measurement at the standard operating voltage is made, followed by a second measurement at a lower voltage. The ratio of the resultant magnetic fields to the transmitter flux should be within about ten percent for each voltage level. After passing the linearity and primary field tests, normal logging operations may commence. It is preferred that the initial two logging runs be reserved for a repeatability test. These back-to-back logs should agree to within about one percent in amplitude and about one degree in phase for logging to proceed. “Warm” transmitter 20 and receiver 24 response should be within the one percent tolerance. Tests may also be performed during logging. [0027] Tests may also be conducted on the measurements after the data collection is complete. One such test is referred to as a profile tie in which transmitter 20 is maintained at a fixed position near the top of the profile and sequentially moves receiver 24 to all of the depths it previously occupied during the analysis. A careful measurement is made at each depth of receiver 24 . This procedure is then repeated for a second position of transmitter 20 within the borehole. The measurements made during the profile tie are used to tie the individual profiles together. [0028] An additional test conducted on the measurements is referred to as a reciprocity test. This reciprocity test involves exchanging the positions of transmitter 20 and receiver 24 . It is preferred to measure reciprocity by establishing at least three positions at known depths, in the boreholes: shallow, intermediate and deep. Measurements are then made with transmitter 20 and receiver 24 in each position in each borehole. This involves measuring the data in the present logging position and then interchanging the transmitter 20 and the receiver 24 and making the measurements a second time. These measurements serve to test the depth control of system 19 , as well as the stability and linearity of the signals propagating between transmitter 20 and receiver 24 . [0029] Although the foregoing has been described with only borehole 12 a being lined with a conductive liner 16 a, in practice either borehole 12 a or 12 b, or both may be lined. An analogous technique may be employed to determine the reduction in the magnetic field sensed by receiver 24 by conductive liner 16 b. As before, the incident magnetic field induces a current in conductive liner 16 b, which acts according to Lenz's law to reduce the magnetic field inside the borehole 12 b. That is, conductive liner 16 b shields receiver 24 from the incident magnetic field in a way similar to how conductive liner 16 a shields and attenuates the magnetic field generated by transmitter 20 . SUMMARY OF THE INVENTION [0030] In one aspect of the invention, a method is provided for conducting an electromagnetic induction survey of a geological formation penetrated by a borehole lined with a conductive casing. The method includes positioning a transmitter in the borehole, whereby the transmitter generates a transmitter magnetic moment, and positioning a distant receiver external of the borehole to detect a magnetic field induced by the transmitter, whereby the distant receiver is disposed across part of the formation from the borehole. Furthermore, an auxiliary receiver is positioned in the borehole proximate the transmitter to detect a magnetic field induced by the transmitter and attenuated by the conductive casing. Subsequently, a first casing attenuation factor that is applicable to the magnetic field measured by the auxiliary receiver is determined from a ratio of the measured magnetic field at the auxiliary receiver and the transmitter magnetic moment. A second casing attenuation factor applicable to the measurement of the magnetic field at the distant receiver is determined from a non-linear relationship (e.g., a power law relationship) between the first casing attenuation factor and the second attenuation factor, wherein the second attenuation factor is less than the first attenuation factor. Then, a formation attenuation factor applicable to the measured magnetic field at the distant receiver is determined from a relationship between the magnetic moment of the transmitter, the second casing attenuation factor, and the measured magnetic field at the distant receiver. Finally, the method correlates the determined value of the formation attenuation factor to a resistivity characteristic of the formation between the distant receiver and the transmitter. [0031] In another aspect of the invention, a method is provided for conducting an electromagnetic induction survey of a geological formation penetrated by a borehole lined with a conductive casing. The method includes positioning a transmitter in the borehole, whereby the transmitter generates a transmitter magnetic moment and positioning a distant receiver external of the borehole to detect a magnetic field induced by the transmitter, whereby the distant receiver is disposed across part of the formation from the borehole. The method also includes positioning an auxiliary receiver in the borehole proximate the transmitter to detect a magnetic field induced by the transmitter and attenuated by the conductive casing, and positioning a second auxiliary receiver about the transmitter. With the second auxiliary receiver, the magnetic field immediately about the transmitter is measured and, from the values of the magnetic field measured by the first and second auxiliary receivers, values for the casing parameters of thickness, permeability, and density are obtained. From the values of the casing parameters, a value of a casing attenuation factor applicable to the measurement of the magnetic field at the distant receiver is further obtained. Then, a formation attenuation factor applicable to the measured magnetic field at the distant receiver is determined from a relationship between the magnetic moment of the transmitter, the casing attenuation factor, and the measured magnetic field at the distant receiver. Finally, the determined value of the formation attenuation factor is correlated to a resistivity characteristic of the formation between the distant receiver and the transmitter. BRIEF DESCRIPTION OF DRAWINGS [0032] FIG. 1 is a schematic diagram illustrating a prior art cross-hole electromagnetic tomography system; [0033] FIG. 2 is a schematic diagram of an electromagnetic tomography system according to the present invention; [0034] FIG. 3 is a schematic diagram of an alternative electromagnetic tomography system according to the present invention; [0035] FIG. 4 a illustrates a plot of induction numbers for a typical conductive casing and the phase of a magnetic field induced in an auxiliary receiver within the conductive casing in a borehole, according to the present invention; [0036] FIG. 4 b illustrates a plot of induction numbers for a typical conductive casing and the value of an exponent in a power law relationship used to determine a casing attenuation factor, according to the present invention; [0037] FIG. 5 is a schematic diagram of another alternative electromagnetic tomography system, according to the present invention; [0038] FIG. 6A is a graphical illustration of a master table of casing parameters of a typical conductive casing for pairs of measured magnetic fields induced within the borehole, as utilized by a electromagnetic induction survey method according to the present invention; [0039] FIG. 6B is a graphical illustration of a master table of casing attenuation factors for sets of casing parameters, as utilized by a electromagnetic induction survey method according to the present invention; and [0040] FIG. 7 is a schematic diagram of yet another alternative electromagnetic tomography system according to the invention. DETAILED DESCRIPTION [0041] Embodiments of the present invention utilize an auxiliary receiver, an auxiliary transmitter, or both to facilitate the correction of shielding effects of conductive casings. In one embodiment, as shown in FIG. 2 , a system 19 employed to analyze the geological formation 10 includes a transmitter 20 disposed in borehole 12 a and a receiver 24 disposed in a borehole 12 b. Alternatively, transmitter 20 and receiver 24 may be disposed in the same borehole for single borehole tomography (not shown). For purposes of the present description, system 19 may be referred to as an electromagnetic tomography system or a system for conducting electromagnetic induction surveys. [0042] The transmitter 20 typically comprises multi-turn wires wound around a magnetically permeable (e.g., mu-metal or ferrite) core and other electronic control components (e.g., a capacitor); (not shown). The receiver 24 typically comprises more than one antenna (not shown). These antennas may point to the x, y, and z directions, respectively, to detect different magnetic field components. These antennas similarly comprise multi-turn wires wound around magnetically permeable metal cores so that an external magnetic field will induce a current to flow through the wire(s). The receiver 24 also comprises other electronic components (not shown) to detect the current (or voltage) thus induced. It will be appreciated by those skilled in the art that other types of antenna configurations may be used to implement the invention (e.g., saddle coils, segmented antennas, tri-axial antennas, etc.). Transmitter 20 and receiver 24 may be deployed using standard seven conductor wireline winches, cables, and standard seven-pin Gerhard-Owens cable connectors, shown generally as 26 . System 19 may be operated using a computer (not shown) included in surface station 28 , which is in data communication with transmitter 20 and receiver 24 . [0043] Table 1 shows various operational parameters of a representative transmitter. Note that this is but one example; different transmitters with different physical characteristics will have different operational parameters. As shown in Table 1, this transmitter provides large magnetic moments at low (alternating current) frequencies where the inductive reactance of the transmitter is small. This reactance increases with the frequency; as a result, the magnetic moment of the transmitter decreases. That higher frequencies produce lower magnetic moments is generally true with any transmitter; this is not unique to this particular transmitter. However, higher frequencies afford better resolution of maps of geological formations. Therefore, in practice, it is often desirable to find a compromised (optimum) frequency for the analysis of a geological formation. The optimum operating frequency depends on the borehole separation and formation resistivity. Too low a frequency limits the resolution, while too high a frequency reduces the effective transmitter magnetic moment, hence the range of detection. Table 1 shows that reduction in the transmitter moment becomes more significant at frequencies of 90 Hz and above. It is apparent from Table 1 that this transmitter will provide sufficient moments at frequencies below 370 Hz. However, if conductive casings are used, it will be necessary to operate the transmitter at an even lower frequency because conductive casings act as low-pass filters. TABLE 1 Typical Receiver Noise Frequency Max Moment B z noise (fT) B x noise (fT) 1 3000 30 80 5 3000 25 60 10 3000 15 50 24 3000 12 50 45 2800 8 25 90 2100 5 18 190 1600 3 15 370 900 3 15 759 300 6 15 1848 180 9 15 [0044] As discussed above, a receiver may include multiple antennas (not shown), pointing to the x, y, and z directions, respectively, with the z direction being along the axis of the borehole. Due to geometric constraints, the antennas in the x and y directions are not as long as that in the z direction. As a result, the z antenna is more sensitive, i.e., the field (B z ) sensed by the z antenna typically has lower noise than that sensed by the x or y antenna (see B x in Table 1). [0045] The range of operation for an electromagnetic tomography system (e.g., system 19 in FIG. 2 ) and the operating procedures are somewhat dependent on the formation resistivity and the presence (or absence) of conductive well casing ( 16 a and 16 b in FIG. 2 ). Using transmitters and receivers commonly available in the art, a typical system may have a maximum range of about one kilometer in fiberglass cased wells or open holes (i.e., in the absence of conductive casing). This range is reduced to approximately 400 meters if one of the wellbores is cased with conductive materials. Assuming a maximum tool separation of approximately 1 kilometer, the borehole separation should probably be no more than 650 meters so that transmitter 20 and receiver 24 will remain within the maximum separation of 1 kilometers when they travel up and down the boreholes. [0046] Before commencing analysis of geological formations, a desired frequency of operation should be selected. Because higher frequencies produce better resolution in the images of the formations, the desired operating frequency typically would be the highest frequency with which reliable data may be collected over the entire profile length (the axial length of the borehole). This frequency may be established based on two simple relations: the primary field relation and the skin depth equation. [0047] The primary magnetic field is the field present in the absence of a geological formation for the vertical magnetic field (B z ) (from equation 2a with the x and z axes interchanged) when transmitter 20 and receiver 24 are positioned at the same vertical level. The vertical magnetic field, B z may be expressed by B z = 100 ⁢ M R 3 ( 7 ) where M is the transmitter moment in A.m 2 , R is the separation between the boreholes in meters, and B z is the vertical (z direction) magnetic field in nano Teslas (nT, 10 −9 T). This equation may be used as a rough estimate when vertical levels of transmitter 20 and receiver 24 differ somewhat. [0048] The skin depth (δ) is defined as the distance through which an electromagnetic plane wave of frequency f propagates before attenuation to 1/e (0.37) of its initial amplitude. At two skin depths, the attenuation is 1/e 2 (0.135), and at four skin depths, it is 1/e 4 (0.018). While this relationship is not strictly applicable at locations close to the transmitter, it is an approximate measure of how much of a supplied primary field is converted into the induced currents, which in turn produce the secondary fields required for electromagnetic imaging. The skin depth (δ) is a function of the formation resistivity ρ and the electromagnetic wave frequency f. Thus, skin depth δ may be defined approximately as follows: δ ≈ 500 ⁢   ⁢ ρ f ( 8 ) where ρ is the resistivity (in Ohm•m) of the formation. [0049] From equations (7) and (8) and the source moment, the approximate field level at any cross-hole distance can be estimated. For example, assuming a separation of 200 m between boreholes and a transmitter magnetic moment of 1000, the maximum primary field (when transmitter 20 and receiver 24 are at the same vertical level) from Equation 7 is 0.0125 nT. This is well above the receiver noise for any frequency of operation (see Table 1). [0050] During operation, transmitter 20 and receiver 24 are positioned at various vertical levels above, within, and below the area of interest. Thus, transmitter 20 and receiver 24 will typically be separated by a distance more than that between the boreholes. For a borehole separation of 200 meters, transmitter 20 and receiver 24 might be separated up to 400 meters during operation. At a diagonal separation of 400 meters between transmitter 20 and receiver 24 , equation (7) shows that the primary field would be reduced to approximately 0.0016 nT, which is still above the receiver noise for any frequency of operation (see Table 1). [0051] Equation (8) indicates that at a transmitter frequency of 200 Hz and a formation resistivity of 8 Ohm•m, the skin depth of the transmitter moment is about 100 meters ( δ = 500 ⁢   ⁢ 8 200 = 100 ) . Therefore, the borehole separation (200 m) in the above example is about twice the skin depth, and so the field (0.0125 nT as calculated above) would be further attenuated by the formation by a factor of 0.135 to 0.0017 nT, when transmitter 20 and receiver 24 are at the same level. If transmitter 20 and the receiver 24 are not at the same level, the field would be further attenuated by the increased separation between them; for example, by a factor of 0.018 when transmitter 20 and receiver 24 have a diagonal separation of 400 m (four times the skin depth). Thus, at a diagonal separation of 400 m, the field strength will be about 2.8×10 −5 nT or 28 fT (0.0016 nT×0.018=2.8×10 −5 nT), which is only a few times the noise level at 200 Hz (about 3 fT, see Table 1). This calculation indicates that a diagonal separation of about 400m between transmitter 20 and receiver 24 may be approaching the maximum range under the circumstances (i.e., 200 Hz transmitter frequency and 8 Ohm•m formation resistivity). [0052] As a general rule, an operating frequency is chosen by using the skin depth relation defined by equation (8) such that it will produce a skin depth about half the distance between the boreholes. In other words, the separation between the boreholes should generally be twice the skin depths. This is shown quantitatively as follows: Separation , R , = 2 ⁢   ⁢ δ = 1000 ⁢   ⁢ ρ f ( 9 ) So , f = 10 6 ⁢   ⁢ ρ R 2 ( 10 ) [0053] where R is the separation between the boreholes in meters and ρ is the formation resistivity in Ohm•m. Once a frequency is selected by using equation (10), the magnetic moment for the transmitter will be known. With the magnetic moment, the magnetic field level can then be estimated using equation (7). This magnetic field will be multiplied by the attenuation factor as described above to estimate the minimum field for the farthest diagonal separation between the receiver and the transmitter. If the minimum field is above the system noise level (e.g., those shown in Table 1), then the frequency is suitable. If the minimum signal level falls below the system noise level, the operating frequency should be reduced. It is preferred to reduce the frequency than to collect incomplete data profiles. [0054] If one of the boreholes (e.g., 12 a ) is cased with a conductive liner (e.g., 16 a; see FIG. 3 ), calculations should include casing attenuation effects because, as discussed previously, a conductive liner effectively “shields” a transmitter from a receiver. The transmitter moment is effectively reduced by a casing attenuation factor k c (or casing response factor) so that the effective moment seen by the receiver at some distance away can be expressed as: M eff =k c M T   (11) [0055] Table 2 provides estimates of the signal attenuation due to a “typical” oil field conductive liner (e.g., steel casing). To use this table, one multiplies the expected field by the corresponding attenuation factor (k c ) given in the table. Using the example discussed above, it is found that the liner attenuation at 190 Hz is 0.005, and about 0.004 at 200 Hz. The minimum expected vertical magnetic field (B z ) from the above example (at 200 Hz), therefore, can be determined using the equation: B z ≈0.0016×0.004≈6.4×10 −6 nT (or 6.4 nT). Note that this value is approaching the noise level listed in Table 1, and it would be preferred to decrease the operating frequency to a lower frequency (e.g., 90 Hz). TABLE 2 Frequency Attenuation 1 1.0 5 .9 10 .6 24 .3 45 .1 90 .08 190 .005 370 .001 759 .00001 1848 .0000001 [0056] In addition to general attenuation, the conductive casings present further problems because they are often not perfectly homogenous. For example, the properties of the casing may vary from one depth to another. As discussed above, such inhomogeneity may render the prior art correction methods impractical. In accordance with the present invention, the effects of such casing inhomogeneity is mitigated by providing an auxiliary receiver 54 in the proximity of transmitter 20 (see FIG. 2 ). Auxiliary receiver 54 permits detection of a magnetic field, B a , the characteristics of which is dependent primarily on the casing properties (not on the formation properties). The magnetic field B a at auxiliary receiver 54 can then be used to correct for casing attenuation effects in the magnetic field that is induced in receiver 24 . Specifically, a magnetic field B a is induced in the auxiliary receiver 54 . The magnetic field B a is related to the magnetic moment M T of transmitter 20 , a casing attenuation factor k T , and a geometric factor a (taken from equation (2a)). This relation is expressed as follows: B a =ak T M T   (12) The casing attentuation factor, K T is a function of the properties of conductive liner 16 a. Because auxiliary receiver 54 is inside liner 16 a and in close proximity (e.g., ≦2 m) to transmitter 20 T, the magnetic field B a sensed by auxiliary receiver 54 is dominated by the properties of the conductive liner 16 a. Close proximity refers to a distance within which the magnetic field sensed by auxiliary receiver 54 is influenced primarily by the conductive casing and not by the formation. This distance is typically less than a few meters from transmitter 20 . In contrast, if auxiliary receiver 54 is far away (e.g., ≧10 m) from transmitter 20 , the magnetic field sensed by auxiliary receiver 54 will also depend on the formation properties. [0057] With a fixed separation between auxiliary receiver 54 and transmitter 20 , K T becomes a function of only the conductive casing properties or casing parameters (e.g., radius r l , thickness t c , conductivity σ, and permeability μ). Presumably, the factor K T could be calculated given the properties of conductive liner 16 a and the dimensions and properties of transmitter 20 . In respect to one method according to the invention, K T does not need to be accurately determined, nor does it have to reflect variations in the properties of an inhomogeneous liner. The factor K T is generally obtained from ratio of the magnetic field B a measured by the auxiliary receiver and the transmitter moment M T known for the transmitter 20 . The magnetic moment M T is known since the current in the transmitter is measured accurately as part of the whole system operation and the geometric factor a is also known from the fixed geometry of the transmitter-receiver structure. Once K T is determined, the effects of the properties of conductive liner 16 a may be compensated for when sensing a magnetic field with a receiver disposed far (≧10 m) away from transmitter 20 . Note that this receiver could be a receiver (not shown) disposed in the same borehole 12 a or a receiver (e.g., receiver 24 ) disposed in borehole 12 b. In other words, embodiments of the invention are applicable in either single borehole or cross-borehole tomography. [0058] Accordingly, in one aspect of the invention, measurement of the magnetic field B a at the auxiliary receiver 54 (adjacent the transmitter 20 ) provides a measure of casing attenuation. This measurement is used to predict the casing attenuation affecting the reading of the distant receiver. The measured field at the distant receiver can then be corrected and the undistorted field recovered. In more detail, the measured field at the distant receiver is given by equation 2: B R =bk f M eff   (13) where M eff is the moment attenuated by the casing attenuation factor k c , so that in general B R =bk f k c M T   (14) [0059] In accordance with the present invention, k T and k c are determined to be functions of the casing parameters alone and are simply related. By determining the relationship between k T and k c , the measurement of the field at the auxiliary receiver, B a , may be used to predict the casing attenuation factor k c at the distant receiver and, in turn, to recover the desired formation factor, k f . [0060] In more detail, suppose that k c is a function of k T , e.g. k c =F(k T ). Now the field at the auxiliary receiver is given by B a =ak T M T , so k T =B a /aM T and thus k c =F ( B a /aM T )   (15) [0061] So, the measured magnetic field at a distance from the first borehole becomes: B R =bk f F ( B a /aM T ) M T   (16) [0062] Since M T , a, and b are known (by direct application of equation 2a and a knowledge of the spatial locations of the auxiliary and distant receivers), the desired formation factor k f can be determined from the measured magnetic field. [0063] In an earlier application, Applicants made the assumption that the functional relationship between k T and k c is linear, i.e. k T =βk c . In practice, this assumption, that the ratio of k c /k T is a constant, does work to reduce the effects of casing variations in the predictions of B R . Residual casing effects (due to casing variations) remain, however, and distorts the predictions of B R . Consequently, errors in the computation of k f are introduced. [0064] In accordance with one method according to the invention, the functional relationship between k c and k T that is employed is a power law relationship, i.e. k c =(k T ) β . Applicants observe that the magnetic field outside the first casing is attenuated by an initial complex factor, k c . In respect to the reading by auxiliary receiver 54 , this magnetic field is again attenuated as it reenters the casing near the auxiliary receiver. As an approximation, it may be assumed that the magnetic field is attenuated the second time, by the same factor, k C . Thus, the resulting attenuation factor k T of the magnetic field detected by the auxiliary receiver may be expressed as: k T =k c 2 or k c =k T 0.5   (17) [0065] From the above expression for k T , the casing attenuation factor, k C may be further expanded as the square root of k T or k C =k T 0.5 . From the reading of B a , B R may be expressed as: B R =bk f k T 0.5 M T   (18) [0066] Because M T is known and auxiliary receiver 54 provides a measurement of B a , k T (and k T 0.5 ) is determined from the relationship, k T =B a /aM T . This allows for the casing attenuation factor k C to be determined directly from k T and then plugged into the equation above for B R . Accordingly, the formation attenuation factor, k f , may be determined from the reading of the magnetic field, B R , by the distant receiver, 24 . As is generally known to those skilled in the relevant art, the formation attenuation factor k f provides a measurement or indication of the electrical resistivity of the formation between the boreholes 16 a, 16 b. [0067] In yet another preferred embodiment of the invention, an improved, more accurate relationship between k C and k T is determined and employed. By way of numerical modeling techniques, Applicants have determined that the relationship between k C and k T employed above (k C =k T 0.5 ) is an approximation that may still afford room for improvement. After further analysis, Applicants concluded that the value of the exponent β depends on the value of the product of certain casing parameters: conductivity (σ), permeability (μ), and thickness (t). This product is referred to as the induction number, Θ. In a further aspect of the inventive method, a rough measure of Θ is derived from the actual measurement of the magnetic field, B a , by the auxiliary receiver 54 . As can be appreciated by those skilled in the relevant art, the measurement of magnetic field B a has both a real and an imaginary component. In accordance with the present method, the value of the induction number Θ) is correlated with the phase of B a . Specifically, a rough measure of Θ is derived from the phase of the measured magnetic field B a . [0068] FIG. 4 a is a plot of the phase of B a as a function of Θ for a wide range of σ, μ, and t values (values typical of casings). The plot reveals that the phase of B a is a smooth function of the induction number, Θ. In the preferred implementation of the method, the phase of the measured B a field is used to determine an approximate value of Θ. Preferably, a master table is already generated of Θ values (i.e., different combinations of σ, μ, and t) for expected ranges of value of the phase of B a . This table may be generated for a variety of common casing types. Upon a reading of the magnetic field B a or, more particularly, the phase of B a , the value for Θ is readily obtained from the master table (typically stored in a computer database and accessed via a computer program). [0069] Next, the value of Θ is used to determine β in the relation k C =k T β . This step is performed empirically by way of a numerical algorithm for computing k C and k T for a given casing. The ‘best’ value for β is found iteratively. In other words, a value of β is found which makes k C /k T β , close to one over a small range of σ, μ, and t around the induction number, Θ. The ‘best’ value of β is then applied to predict k c and hence determine k f . FIG. 4B provides a plot β vs θ. for a typical, exemplary casing. [0070] In yet another approach to addressing the casing variations effects (in crosshole electromagnetic surveys), a measurement is taken of the magnetic field threading the transmitter as well as the magnetic field, B a , at the auxiliary receiver 54 , B a . From the two measurements, relatively accurate values of σ, μ, and t of the casing may be determined from which the value of k C may be obtained. [0071] Referring to the alternate system illustrated in FIG. 5 , the magnetic field threading the transmitter is measured by encircling the transmitter 20 coil or solenoid with several turns of wire, (i.e., another receiver) as shown by the single turn 21 . Like the receivers described above, (e.g., auxiliary receiver 54 ) the voltage developed across this coil is proportional to the time rate of change of flux within it. In this description, the magnetic field measured by this 21 receiver is referred to as B T . [0072] In accordance with this variation of the inventive method, the casing attenuation factor k C is determined without actually computing values of σ, μ and t. The casing attenuation factor, k C , is obtained directly from the measurement of B a and B T . Preferably, the determination of k c is performed by way of a numerical analysis technique: [0073] In an exemplary method, a three dimensional table is constructed of computed B a and B T values for the entire range of σ, μ and t values likely to be encountered. Such a table may be generated for a variety of common casing types and of a specific radius. FIG. 6A is a graphical illustration of a typical pair of B a and B T values for a particular set, σ i μ j t k , of casing parameters. The values of B a and B T are calculated at a succession of points in σ, μ and t spaced at intervals sufficiently small so that the fields vary linearly between points in the table. The result is a three dimensional mesh or table of the values of B a and B T for any value of σ, μ and t. This is referred to as the master casing parameteres table. The table need only to be calculated only once for the entire range of anticipated casing parameters and for the fixed spacing of the auxiliary receivers and chosen operating frequencies. Adjacent points in σ, μ and t space define an elemental rectangular volume. The values of B a and B T at an arbitrary value of σ, μ and t within this elementary volume can be obtained by linear interpolation between the values on the vertices of the elementary volume. Conversely the values of σ, μ and t may be linearly interpolated for a specified pair of B a and B T within the volume. [0074] Referring to FIG. 6B , the values of k c are entered in a second three dimensional table for the same set of σ, μ and t values used to create the master casing parameters table. FIG. 6B provides a graphical illustration of this second table. [0075] Thus, in accordance with the inventive method, measured values B a and B T are obtained from auxiliary receiver 54 and second auxiliary receiver 21 , respectively. Then, given the pair of B a and B T values, the master table is iteratively searched, interpolating as necessary to locate the corresponding σ, μ and t values. Given the σ, μ and t values, the value of the casing attenuation factor, k C , for that set of σ, μ and t values is obtained from the second table. Lastly, the formation factor k f is obtained from the measured magnetic field B R and the known values of M T , b, and k C . [0076] The method is made relatively fast, through use of computer means and database embodying the first and second table. The range of casing parameters is typically 10 6 to 10 7 S/m for σ, 20 to 200 for μ and 0.3 to 0.7 in. for t. The values of B a and B T are slowly varying functions of σ, μ and t, so it is only necessary to have 10 points per decade for the σ and μ values and perhaps 5 or 6 values spanning the range of t. There are consequently less than a thousand points in the master table. Accordingly, determination of the correction factor k c is essentially instantaneous. [0077] While the embodiments shown in FIG. 2 and FIG. 3 are for single-hole cased applications, the embodiment illustrated in FIGS. 6 and 7 can be used when both boreholes 16 a. 16 b are cased with conductive materials. The field measured at a receiver within a cased borehole, B R , now has an additional attenuation factor k r so that the measured field becomes: B R =bk f k c k r M T   (19) [0078] In this embodiment, system 19 includes both an auxiliary receiver 54 and an auxiliary transmitter 72 (see FIG. 7 ). Auxiliary receiver 54 can be used to correct the effects of the inductive liner 16 a, while auxiliary transmitter 72 can be used to correct the effects of the inductive liner 16 b. Like the placement of the auxiliary receiver 54 , the auxiliary transmitter must be placed close enough to the receiver, e.g. within a meter or two, so that the magnetic field at the receiver depends only on the casing and not on the formation. The procedures for performing such corrections are the same as described above. [0079] In the system of FIG. 5 , the second borehole 12 b is a second conductive casing 16 b. Preferably, the borehole 12 b is further equipped with a second transmitter 72 placed adjacent the distance receiver 24 . Further, the second transmitter 72 is encircled by another receiver 73 similar in configuration and function to receiver 21 in the first borehole 12 a. In this case, the magnetic field measured at receiver 24 , B d , from auxiliary transmitter 72 and the field measured by the receiver 73 encircling the auxiliary transmitter, 72 , B g , are sufficient to define σ, μ and t of the casing 16 b. The values for these properties in turn serve to predict the casing attenuation factor K r at the receiver 24 . [0080] The casing attenuation factor k r is computed each time the receiver is placed at a new position in borehole 16 b and before the transmitter 20 is activated. The correction is then applicable to all the readings of receiver 24 as the transmitter 20 is moved over its range of depths in borehole 16 a. [0081] The magnetic field data obtained from the tomography are used in electromagnetic (EM) modeling to derive the resistivity distribution between the boreholes. EM modeling may employ approximate methods for forward solutions or use a least square inversion technique to fit the data. These techniques are well known in the art, and any such technique may be used. In this process, it may be more convenient to assume a cylindrical symmetry and Born approximation (low contrast scattering). Alternatively, a two-dimensional rectangular geometry may be assumed and more general low scattering assumption may be included. In one method, a three-dimensional EM modeling is used, though this approach requires more computer resources. [0082] While the invention has been described using a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate that other variations are possible without departing from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

A method is provided for conducting an electromagnetic induction survey of a geological formation penetrated by a borehole lined with a conductive casing. The method includes positioning a transmitter in the borehole, whereby the transmitter generates a transmitter magnetic moment, and positioning a distant receiver external of the borehole to detect a magnetic field induced by the transmitter, whereby the distant receiver is disposed across part of the formation from the borehole. Furthermore, an auxiliary receiver is positioned in the borehole proximate the transmitter to detect a magnetic field induced by the transmitter and attenuated by the conductive casing. Subsequently, a first casing attenuation factor that is applicable to the magnetic field measured by the auxiliary receiver is determined from a ratio of the measured magnetic field at the auxiliary receiver and the transmitter magnetic moment. A second casing attenuation factor applicable to the measurement of the magnetic field at the distant receiver is determined from a non-linear relationship (e.g., a power law relationship) between the first casing attenuation factor and the second attenuation factor, wherein the second attenuation factor is less than the first attenuation factor. Then, a formation attenuation factor applicable to the measured magnetic field at the distant receiver is determined from a relationship between the magnetic moment of the transmitter, the second casing attenuation factor, and the measured magnetic field at the distant receiver. Finally, the method correlates the determined value of the formation attenuation factor to a resistivity characteristic of the formation between the distant receiver and the transmitter.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/830,725, filed on Jun. 4, 2013, to Robert L. Fairchild, Jr., entitled “Clamshell Carton with Locking Tab,” the entire disclosure of which is hereby incorporated by reference. FIELD OF THE INVENTION [0002] The present invention is directed toward an improved clamshell carton which may preferably be made of paperboard or similar materials. Such clamshell cartons are often used in the fast food industry to contain and serve food items. However, such clamshell cartons may be made from other materials and may have many alternative uses. BACKGROUND OF THE INVENTION [0003] Foldable clamshell cartons are used in the packaging industry with prolific use in the fast food industry. Foldable clamshell cartons constructed of paperboard are becoming more popular due to the fact that they can be shipped in an unfolded state and assembled on premises, are lighter weight, and/or consume less shipping volume. These characteristics may individually or collectively reduce manufacturing and/or shipping costs. Current foldable clamshell cartons usually have a catch arranged between the free edges of the front panels of the lid portion and the base portion. The catch may be positioned in the corners or the middle of the front panels and at a location where the lid portion otherwise overlaps or meets with the base portion. These catches are typically sufficient to keep the lid portion from becoming disengaged with the base portion when the carton is not being handled. However, the lid portion and the base portion often become spontaneously disengaged due to residual elastic forces present in the material if the folds are not fully completed or become deformed. Further, the lid portion often disengages the base portion causing spillage of the contents of the carton upon applying a lifting force to the lid or a constricting force upon the sidewalls to grip the carton, such as the forces required to remove the carton from a paper or plastic bag. [0004] Thus, there is a need in the art to provide a foldable clamshell carton having an improved locked position to prevent the disengagement of the lid portion from the base portion during handling and transport of the foldable clamshell carton and the contents thereof. SUMMARY OF THE INVENTION [0005] The present application is directed toward a clamshell carton assembled from a foldable blank. The carton includes a base and a lid. The base generally includes a bottom panel and a plurality of walls extending upwardly therefrom when the carton is in an assembled and closed position. The lid generally includes a top panel and a plurality of walls extending downwardly therefrom when the carton is in an assembled and closed position. In one embodiment, the carton may include four walls. However, other embodiments may include other wall configurations, such as three walls or more than four walls. [0006] The base may include a tab extending from one of the plurality of base walls. The tab may generally have a width and a length and may have the shape of a trademark or logo of a retailer. The transition between the wall and the tab may be defined by a score line. The score line may make it easier to fold the tab relative to the wall. The length of the tab may be defined from the score line to the distal end of the tab, wherein the length may be greater than, less than or equal to a distance from a trailing edge of a front panel of the lid normal to the fold line between the front panel and top panel of the lid. The base may further include a height of its front panel being substantially similar of the sum of a height of a rear panel of the base and a height of a rear panel of the lid. [0007] The lid and the base of the carton may each include a fold line present at the intersection of each of the walls with the respective top and bottom panels. The fold lines may be disposed on the foldable blank during manufacturing and allow the carton to be easily folded at those locations. The lid may also have a slit defined therein proximate one of the fold lines. The lid may also have a slot cut into the top panel inward of the slit. The slot may be parallel to the slit. The slot may be configured for receiving a distal end of the tab. [0008] The tab and the slit may be arranged on the foldable blank so that they align when the carton is in a folded position. The slit may be sized and adapted for receiving the tab therethrough to facilitate the retention of the lid in a closed position. In one embodiment, the tab is arranged on the front panel of the base and the score line may be located near or at the upper edge of the front panel of the base. The slit may be arranged proximate the fold line between the front panel and the top panel of the lid. The slot may be arranged parallel to and/or inward of the slit. However, the tab may be disposed on any of the walls of the base and the slit may be disposed proximate any fold line of the lid opposite the tab. [0009] In one embodiment, the front panel of the lid may include a window area defined therein. In another embodiment, the window area may correspond in shape with the tab to reduce waste when cutting out the foldable blank from the stock material. [0010] When the present carton is assembled, the carton may include a locked position, wherein the locked position includes the tab being received into the slit, the tab being folded at the score line, the tab being orientated substantially parallel to the top panel of the lid, and the terminal end of the tab received into the slot in the top panel of the lid. [0011] Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING [0012] In the accompanying drawing, which forms a part of the specification and is to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views: [0013] FIG. 1 is a top perspective view of a clamshell carton with locking tab illustrating the carton in a closed and locked orientation in accordance with a first embodiment of the present invention; [0014] FIG. 2 is a top perspective view of a clamshell carton of FIG. 1 illustrating the carton in an open orientation in accordance with a first embodiment of the present invention; [0015] FIG. 3 is a top perspective view of a clamshell carton with locking tab illustrating the carton in a closed and partially locked orientation in accordance with a first embodiment of the present invention; [0016] FIG. 4 is an enlarged top perspective view illustrating the locking tab and slot of the clamshell carton in accordance with a first embodiment of the present invention; [0017] FIG. 5 is a top plan view of a blank used to form a clamshell carton with a locking tab in accordance with a first embodiment of the present invention; [0018] FIG. 6 is a top plan view of a diagram illustrating a plurality of blanks as they may be cut from a single sheet or roll of paperboard in accordance with a first embodiment of the present invention; [0019] FIG. 7 is a top perspective view of a clamshell carton with locking tab illustrating the carton in a closed and locked orientation in accordance with a second embodiment of the present invention; [0020] FIG. 8 is a top plan view of a blank used to form a clamshell carton with a locking tab in accordance with a second embodiment of the present invention; and [0021] FIG. 9 is a top plan view of a diagram illustrating a plurality of blanks as they may be cut from a single sheet or roll of paperboard in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0022] The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures. [0023] The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled. [0024] Referring to the figures, one embodiment of the present invention is directed to a clamshell carton 10 having a tray or base 12 hingedly attached to a cover or lid 14 . As discussed in greater detail below, the carton 10 includes a unique latch or lock construction for retaining the lid 14 in a closed orientation relative to the base 12 . [0025] As shown in FIG. 2 , the base 12 includes a bottom panel 16 from which a front panel 18 , rear panel 20 and opposing side panels 22 extend upwardly therefrom. Glue tabs 24 may be provided for adhesively joining the side panels 22 with the front and rear panels 18 and 20 . The lid 14 includes a top panel 26 from which a front panel 28 , rear panel 30 (see FIG. 5 ) and opposing side panels 32 extend downwardly therefrom when top panel 26 is disposed opposite and above bottom panel 16 as shown in FIG. 1 . Lid 14 may also include a plurality of glue tabs 34 extending from side panels 32 and/or front and rear panels 28 , 30 for adhesively joining the side panels 32 with the front and rear panels 28 and 30 . Rear panel 30 of the lid 14 is foldably secured to the rear panel 20 of the base 12 by a hinge line 36 . [0026] As illustrated best in FIGS. 2 and 5 , the locking construction of the carton 10 includes a tab 38 extending from an upper edge 40 of base front panel 18 . While shown as having a generally triangular or “A” shape, it will be understood that the tab 38 may be of any suitable shape and may be shaped to accommodate a recognizable trade symbol or artwork design 64 . A first cut or slit 42 is provided in top panel 26 proximate the fold line 44 joining the front panel 28 and top panel 26 of the lid 14 . A shown in FIG. 5 , the width w s of the slit 42 corresponds to the width w t of the tab 38 , as shown in FIG. 5 , and is at least wide enough to allow the tab 38 to extend substantially through the slit 42 . [0027] As demonstrated in FIG. 1 , when the carton 10 is in a closed orientation, the tab 38 may extend through the slit 42 . The tab 38 can then be folded along its base at score line 46 (see FIG. 5 ) such that the tab 38 lies generally parallel to the top panel 26 of the lid 14 . A distal end 48 of the tab 38 can then be inserted or tucked into a second cut or slot 50 formed into the top panel 26 of the lid 14 . As shown in FIGS. 3 and 4 , the length I t of the tab 38 is slightly longer that the distance d s between the slot 50 and fold line 44 . [0028] As shown in FIG. 5 , additional cuts 52 and 54 intersecting slot 50 may be provided so that when the tab 38 lies flat on the top panel 26 , a user may push the end 48 of the tab generally downwardly to effectuate the engagement or tucking of the end 48 of the tab 38 into the slot 50 . When the tab 38 is inserted into the slot 50 , the tab 38 acts as a strap to hold the lid 14 closed with respect to the base 12 . [0029] In one embodiment best shown in FIG. 5 , the front panel 18 of the base 12 has a height h fb , that is approximately equal to the combined heights k rb and h rl of the rear panels 20 and 30 of the base 12 and lid 14 such that when the carton 10 is in a closed orientation, the top edge 40 of the front panel 18 extends to and is positioned generally against the fold line 44 . This positions the score line 46 of the tab 38 is the same general axis as the fold line 44 of the lid 14 thereby enabling the tab 38 to be pivotally folded downwardly at fold line 46 when the lid 14 is in a closed position. [0030] As further shown in FIG. 5 , the carton 10 can be constructed from a flat blank of material that may be formed of paperboard or other suitable material. FIG. 6 illustrates a layout diagram comprising multiple blanks 10 A and 10 B as they may be cut from a single sheet or roll of material. It will be understood that, depending on the width of the roll, either more or less than two blanks 10 A and 10 B may be positioned across the width of the roll. As shown in FIG. 6 , the tab 38 of a trailing blank 10 B may be cut, at least partially, from the front panel 28 of the lid 14 of a leading blank 10 A. In one embodiment, the tab 38 is of a length I t such that the leading edge 40 of a trailing blank 10 B abuts the trailing edge 56 of a leading blank 10 A in order to even further reduce or eliminate paper waste between the blanks 10 A and 10 B. [0031] It will be appreciated that the tab 38 can be shaped to represent or accommodate the printing of a trade symbol or artwork design 64 (represented for illustrative purposes by an “A” in FIGS. 1 , 2 and 5 ) of a particular food vendor. Further, because the tab 38 of one blank 10 B may be cut from the front panel 28 of the lid 14 of another blank 10 A, the front panel 28 may include a window area 58 defined therein. The window area 58 may correspond in shape with a distal portion of the tab 38 . The inclusion of window area 58 provides the ability to print an additional trade symbol or artwork design 66 on the front panel 18 of the base 12 that will be visible through this window area 58 as demonstrated in FIG. 1 . Conversely, if such a window area 58 is not desirable, the tab 38 of a trailing blank 10 B need not be cut from the front panel front 28 of the lid 14 of a leading blank 10 A, thereby resulting in an uninterrupted surface in the front panel 28 . [0032] FIGS. 7-12 illustrate a second embodiment of a carton 100 , which is similar in nature to the carton 10 shown in FIGS. 1-6 . As shown in FIG. 7 , the shape and placement of the locking construction of carton 100 differs from that of carton 10 . For example, as shown in FIG. 8 , the tab 38 ′ may be of a shorter length h. As shown in FIG. 9 , the shorter length I t allows the leading edge 40 of a trailing blank 100 B to abut the trailing edge 56 of a leading blank 100 A in order to reduce or eliminate paper waste between the blanks 100 A and 100 B when tab 38 ′ corresponds in shape with window 58 ′ as shown in FIG. 9 . Accordingly, the distance d s between the slot 50 and fold line 44 is reduced so that such distance d s remains slightly less than the length I t of the tab 38 ′ thereby permitting the end 48 of the tab 38 ′ to be inserted into the slot 50 . In addition, tab 38 ′ may have a wider width w t so as to provide a wider extent of the hold down action provided by the locking mechanism of the present carton 100 . Additionally, as set forth above, the tab 38 ′ can be of any desired shape, including arc-shaped, as depicted in FIGS. 7-10 . [0033] As shown in FIG. 8 , the carton 100 may further include an anti-binding feature 60 and vents 62 that may be selectively opened or removed. As shown in FIG. 8 , anti-binding feature 60 may include crossing slits 63 and 64 wherein the crossing slits intersect proximate hinge line 36 . As shown in FIG. 8 , vents 62 may be circular cut-outs or perforated portions of the rear panel 30 of lid 14 . However, vents 62 may be disposed on rear panel 20 of base 12 , side panels 22 or 32 , front panels 18 or 28 , bottom panel 16 , or top panel 26 . [0034] Other and further embodiments of the present invention will also be appreciated. For example, the carton 10 or 100 may include more than one tab 38 or 38 ′, slit 42 and slot 50 , such that two or more locking mechanisms may be provided. In another embodiment, tab 38 or 38 ′ may extend from a side panel 22 rather than a front panel 18 . In a further embodiment, the tab 38 or 38 ′ may extend from the front panel 28 or a side panel 32 of the lid 14 and a slit 42 and slot 50 may be defined in the bottom wall 16 of the base 12 . In another embodiment, the present carton may comprise any number of walls extending from the top and bottom panel, with three walls being a common variation of the embodiments described above. The use of three walls allows for a triangular or pie-shaped carton. [0035] From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. [0036] The constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.

A carton assembled from a foldable blank including a base having a bottom panel and a plurality of walls and a lid having a top panel and a plurality of walls. The carton may include a tab extending from one of the plurality of walls of the base. The lid may have a slit defined proximate a fold line, the fold line being where at least one of the plurality of walls of the lid meet the top panel, and the slit may be adapted for receiving all or part of the tab therethrough. The lid may also have a slot disposed on the top panel and inward of the slit. After being received through the slit, the tab can be folded about the fold line to lie substantially parallel to the top panel of the lid and a distal end of the tab may be inserted into the slot.

PRIORITY [0001] The present invention claims priority under 35 USC section 119 based upon provisional application Ser. No. 61/268,966 filed on Jun. 18, 2009. FIELD OF THE INVENTION [0002] The present invention relates to security devices and more particularly to security devices for preventing or deterring theft of electronic devices such as portable computers of the laptop or notebook type. BACKGROUND OF THE INVENTION [0003] Computers such as laptop and notebook computers, because of their size and portability, are subject to theft. One particular situation in which theft often occurs is in commercial applications where portable computers are left unattended for a brief period of time. These types of computers are widely used by delivery personnel such as operators of freight vans, postal trucks, power, utility companies and their trucks and others, who, in the course of their routes, will find it necessary to leave their vehicles equipped with a computer unattended for a brief period of time in order to deliver or pick up parcels and packages. It is relatively easy for a thief to enter or break into a vehicle during the brief period the driver is away from the vehicle and remove a computer. [0004] Accordingly, many thefts of this type can be avoided by employing a simple, visible security device which requires time and effort to overcome and, accordingly, will deter thieves. BRIEF SUMMARY [0005] Briefly, the present invention provides a computer security device for portable computers which is securable to a structure and is particularly adaptable for use in mobile application such as in postal, delivery and other mobile vans. The device may be securable to a structure such as a post or pedestal mounted in the vehicle which is secured to the vehicle frame at a location convenient to the vehicle driver. The terms “computer” or “portable computer” as used herein, refer to laptop computers, notebook computers as well as other types of portable electronic device. [0006] The security device of the present invention has a fixed platform having a planar top surface on which the computer is positioned. The planar surface may be cushioned and is provided with apertures or openings for ventilation. The platform is generally rectilinear and one or more adjustable retainers are provided along the sides of the fixed platform. The retainers are both vertically and horizontally adjustable to accommodate various styles and sizes of computers. The retainers are secured in place by proprietary fasteners which require the use of a special driver. [0007] A clamping plate is transversely slidable relative to the fixed platform and also has adjustable retainers. The clamping plate is slidable relative to the fixed platform to accommodate varying sizes of computers. In the locked position, the clamping plate is adjusted so that the retainers on the plate engage the opposite sides of the computer. The clamping plate has a sliding tube that extends into a tubular guide tube on the underside of the fixed platform. The clamping plate is guided by slides extending into appropriate slots on the underside of the fixed platform. [0008] Once the clamping plate has been adjusted and positioned in a clamping position against the computer, the clamping plate is locked in place by a locking assembly having a locking knob. The locking knob has a keylock cylinder which when placed in a locked position allows the locking knob to freely turn on a threaded shaft extending through the sliding tube. Thus, the sliding tube cannot be rotated to an unlocked position. In the locked position, cooperating wedge surfaces on the threaded shaft and slicing tube engage the internal bore in the guide tube preventing movement of the clamping plate. To unlock or release the clamping plate, the keylock is actuated which will cause the knob to become engaged with the threaded rod through a detent permitting the knob to turn the threaded rod to disengage the wedge surfaces unlocking the clamping plate. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The above and other advantages and objects of the present invention will become more apparent when taken in conjunction with the following description, claims and drawings in which: [0010] FIG. 1 is a perspective view of the computer security device of the present invention; [0011] FIG. 2 is a perspective view of the locking knob and key of the present invention; [0012] FIG. 3 is a sectional view taken along lines 3 - 3 of FIG. 2 ; [0013] FIG. 4 is a sectional view taken along line 4 - 4 of FIG. 2 ; [0014] FIGS. 5 and 5A are detail views of the star locking wheel component of the lock assembly; [0015] FIG. 6 is a cross-sectional view of the locking knob taken along line 606 of FIG. 1 ; [0016] FIG. 7 is a longitudinal cross-sectional view of the fixed platform; [0017] FIG. 8 is a cross sectional view of showing the device in an open position; [0018] FIG. 9 is a cross-sectional view showing the fixed mounting plate and the clamping plate in a closed position; and [0019] FIGS. 10 and 11 are cross-sectional views taken along line 9 - 9 of FIG. 6 showing the locking knob in a locked position in FIG. 9 and an unlocked position in FIG. 10 . DETAILED DESCRIPTION [0020] The present invention provides security features for computers including laptop cradles that is easy to use and does not limit productivity. The present invention easily integrates into an existing system. The present invention provides peace of mind in the knowledge that the computer will not be disturbed even under the most adverse conditions. The use of a key locking knob and slim restraining arms provides easy operation and a high degree of security. [0021] Turning now to the drawings, a preferred embodiment of the security device of the present invention is generally denoted by the reference number 10 . The device 10 has a fixed platform 12 and an adjustable clamping table or plate 14 . The fixed platform 12 is preferably rectangular having opposite front and rear walls 16 and 18 , sidewall 20 and a generally planar top surface 22 . The top surface 22 may be provided with strips of resilient cushioning material 24 extending along the opposite sides 16 and 18 . One or more apertures or vent holes 25 may be provided for airflow. A bracket 26 which cooperates with the underside of the platform is secured to a structure such as a pedestal P secured to the vehicle. The bracket 26 is angularly adjustable at knob 27 . [0022] The fixed platform 12 may be fabricated from any suitable material and is preferably fabricated using a lightweight metal or is molded from a suitable, sturdy plastic such as ABS or similar sturdy, rigid thermoplastic. Sidewalls 20 and 54 of the clamping plate each carry a pair of spaced-apart retainer assemblies 30 and 32 , which are similarly constructed. As best seen in FIG. 1 , each of the retainers 30 and 32 has a generally U-shaped base channel 34 which has a projection or flange 36 extending beneath the edge of its respective sidewall. The retainers 30 , 32 , are horizontally adjustable with respect to a slot 35 in the associated wall. A clamping member 40 , also having a generally U-shape, is vertically slidable relative to the base channel 34 . The clamping member has an inwardly extending projection 42 which will engage a surface of the computer. A computer C is represented in dotted lines and may be any of various types and models of smaller, portable computer such as notebook and laptop computers. The retainers 30 , 32 are vertically and horizontally adjusted to accommodate various computers. The retainers 30 , 32 each are secured by a fastener 46 having a proprietary head 48 which requires a special driver tool to be loosened to deter tampering. [0023] Adjustability is achieved by loosening the single fastener 46 associated with each clamping member. When the fastener 46 with a proprietary head is loosened, the vertically sliding clamping member 40 can be adjusted relative to the fastener 56 and to the base channel 34 . Similarly, the entire assembly including the clamping member 40 and the base channel 34 can be moved horizontally in the associated slot 35 in the sidewall. When the desired position is reached with the projection 42 on the end of the clamping member 40 engaging a surface of the computer, the proprietary fastener can be secured. The proprietary fastener 46 has a threaded body which engages a generally oval nut (not shown) on the opposite surface of the sidewalls. The oval nut has a projection 52 which extends into the slots 35 so that the nut cannot be rotated to loosen the retainers 30 , 32 . [0024] The opposite front and rear walls 16 , 18 are each provided with bores 60 in which a stop members 62 may be secured using a fastener, preferably having a proprietary head. The stops 62 associated with the front and rear walls 16 , 18 of the fixed table extend above the surface of the table and will engage the front and rear of the portable computer to prevent it from being slid from beneath the retainers 30 and 32 . [0025] In the normal use position, the cover of the portable computer is open and the computer is positioned as shown in dotted lines in FIG. 1 . The clamps or retainers 30 , 32 associated with the opposite sidewalls of the device will engage the opposite sides of the computer. The stops 62 associated with the front and rear walls of the platform will engage or about the front and rear surfaces of the computer so that the computer is fully engaged and retained so that it cannot be quickly removed without effort or the use of special tools. As mentioned above, the effort and time and special tools that may be involved in order to remove the computer from the security device of the present invention will provide substantial deterrent to theft since in most instances a would-be thief has only several minutes of opportunity in which to remove the computer. [0026] As seen in FIGS. 7 and 8 , the clamping plate 14 has a pair or oppositely disposed slide member 70 . The slide members 70 are received in channels 75 extending along the underside of the fixed platform 14 . In the closed position, the slidable clamping table 14 abuts the fixed platform as best seen in FIGS. 1 and 8 . The sliding clamping plate allows for transverse adjustment to accommodate various widths or portable computers. [0027] Adjustment for accommodating computers having various lengths is generally not required as the platform is sized to accommodate most computers and electronic devices of this type and further the stops 62 on the front and rear walls will prevent the computer from being slidably removed from the security device. Normally the portable computer is positioned on the security device with the cover open, as seen in FIG. 1 . The cover may be closed, but the inwardly extending projections on the claims 30 , 32 on the sidewalls will be positioned between the cover and the body of the computer to prevent the computer from being moved forwardly. Adjustability is achieved by positioning the clamping plate 14 to bring the retainers 30 , 32 into engagement with the opposite side of the computer. The clamping plate 14 is transversely slidable relative to the fixed platform and sliding movement is accommodated by the slides 70 on the opposite side of the clamping table which extend into channels beneath the platform. When the clamping table or section is in the desired position, it can be locked by a locking mechanism to retain further movement. [0028] As best seen in FIGS. 7 , 8 , and 9 , the locking mechanism 100 includes an outer guide tube 102 which extends transversely and is secured to the underside of the platform 14 . The outer tube may be an integrally molded component of the platform or may be secured at the outer end of the tube and by a suitable fastener 106 . The guide tube 102 is fixed and receives an inner slidable tube 110 . The slidable tube 110 extends outwardly from the sidewall 54 on the clamping plate 14 . A bracket plate 112 is welded or otherwise secured to the sliding tube 110 inward of its end and the tubes assembly of components 110 , 112 are secured to the sidewall 54 of the clamping section by proprietary fasteners 120 which extends through the sidewall 54 of the clamping plate and through threaded bores in plate 122 . [0029] Within the inner sliding tube is an elongate threaded rod 125 which is slidable relative to the inner tube 110 . The inner end 128 of the sliding tube 110 has an angled wedge surface 130 . The inner end of the threaded rod has a complementary angular wedge surface 134 . [0030] The outer end of the threaded rod carries a locking knob assembly 150 . The locking knob assembly is best shown in FIGS. 2 to 6 and 9 and 10 includes an inner hub 152 having a central bore which receives an insert 156 . The inner surface of the hub also defines a circular bore 158 which will receive a section of a cylinder lock 175 as will be explained. The insert 156 has a centrally threaded section 160 which is in threaded engagement with the end of the threaded shaft 125 . The insert carries a flange 162 which has a star wheel periphery defined by a plurality of arcuate sections 166 , as best seen in FIGS. 5 , 9 , and 10 . It will be noted that when one of the arcuate section 166 is aligned with the bore 158 , the arcuate sections and bore are positioned so that the bore is fully accessible, as seen in FIGS. 9 and 10 . [0031] The knob 170 of the locking assembly is secured to the hub by a plurality of fasteners at 172 extending from the rear of the hub. The knob has an exterior surface with a series of ribs 174 to facilitate manual rotation of the knob assembly. A bore extends through the knob and receives a cylinder lock 175 . The cylinder lock is rotatable by means of a key 176 . The inner end of the cylinder lock has a projection 180 which is semi-circular and configured to be received within the bore 158 in the hub. A spring-loaded detent ball 182 projects from the curved outer surface of the detent projection. [0032] In the unlocked position, as shown in FIG. 9 , the cylinder lock detent projection 180 extends into the bore 158 of the hub and the arcuate sections 166 of insert 156 engage the projection 180 on the cylinder lock. In this position, rotation of the knob 170 will rotate the insert relative to the threaded knob. As the knob 170 is rotated in a direction to tighten the knob, a locking action will be initiated by the wedge surfaces 130 , 134 causing the end 128 to tightly engage the inner surface of tube 102 . This will secure the table in the position in which it has been placed to properly secure a computer. [0033] If the key is inserted into the cylinder lock and the cylinder rotated placing the semi-circular projection 180 in the position shown in FIG. 10 , in which the detent projection 180 is positioned, disengaged from one of the arcuate sections 166 on the insert, the knob will rotate freely about the threaded shaft preventing unlocking of the clamping table. Thus, the lock assembly is unique in that in the locking knob is disengaged from the threaded rod and can rotate freely when locked and only when the locking assembly is in the unlocked position can the knob be rotated to allow the clamping table to be moved relative to the fixed table, the cylinder is rotated by means of a key to a position so that the cylinder barrel projection and is engagement with one of the arcuate sections in the periphery of the insert which will permit the knob to rotate the insert several turns of rotation to unlock the locking tube mechanism. [0034] It will be obvious to those skilled in the art to make various changes, alterations and modifications to the invention described herein. To the extent such changes, alterations and modifications do not depart from the spirit and scope of the appended claims, they are intended to the encompassed therein.

A security device to secure a computer may include a substantially vertical pedestal, a fixed platform mounted on the pedestal, a clamping table to cooperate with the fixed platform to secure the computer and a locking assembly to allow the clamping table to be moved to allow the computer to be attached and released from the fixed platform in an unlocked state and to prevent the clamping table from being moved to hold the computer in a locked state, The locking assembly may include a locking knob to operate the locking assembly between the locked state and the unlocked state, and the locking knob may rotate freely in the locked state and rotates to allow the clamping table to be moved in the unlocked state.

PRIORITY CLAIM [0001] This application is a continuation of and claims priority to U.S. patent application Ser. No. 10/172,406 filed Jun. 14, 2002 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/517,130 filed Mar. 2, 2000, now U.S. Pat. No. 6,430,919. Each application is incorporated by reference in its entirety as if fully set forth herein. STATEMENT OF RELATED CASES [0002] The invention in this application can be used in conjunction with the related inventions disclosed in the applicant's co-pending and commonly assigned applications of related cases: [0003] U.S. patent application Ser. No. 10/261,174 filed Sep. 30, 2002 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/850,937 filed May 7, 2001, now U.S. Pat. No. 6,484,687; [0004] U.S. patent application Ser. No. 10/261,102 filed Sep. 30, 2002 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/850,937 filed May 7, 2001, now U.S. Pat. No. 6,484,687; [0005] U.S. patent application Ser. No. 10/261,097 filed Sep. 30, 2002 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/850,937 filed May 7, 2001, now U.S. Pat. No. 6,484,687; [0006] PCT Patent application serial number PCT/US02/14414 filed May 7, 2001 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/850,937 filed May 7, 2001, now U.S. Pat. No. 6,484,687, and [0007] PCT Patent application serial number PCT/US01/06617 filed Mar. 2, 2001 which claims priority to and is a continuation of U.S. patent application Ser. No. 09/517,130 filed Mar. 2, 2000, now U.S. Pat. No. 6,430,919. [0008] The above co-pending and commonly assigned applications are herein incorporated by reference in its entirety as if fully set forth herein. FIELD OF THE INVENTION [0009] The present invention relates to pulsed hypersonic compression waves and more particularly to shaped charge devices using pulsed hypersonic compression waves to create thrust. BACKGROUND OF THE INVENTION [0010] In propulsion devices such as jet engines and rocket engines, propulsion thrust is obtained by high-speed exhaust flows. Conventional jet engines obtain the high-speed exhaust by combustion products of fuel and air, while rocket engines obtain the high-speed exhaust by internal combustion products of fuel and oxidizer. The high pressure combustion products are forced through a restrictive orifice, or nozzle, to obtain the high-speed exhaust flow. [0011] Several problems are inherent in the conventional systems. The combustion in both jet and rocket engines must contain extremely high internal pressures and are therefore limited by construction material strength. As the internal combustion pressure increases, the combustion chamber wall must increase in thickness to contain the pressure, increasing the combustion chamber weight proportionally and limiting the design. Also, as the exhaust nozzle diameter is reduced to increase exhaust speed, cooling the engine and nozzle becomes increasingly more difficult. In addition, pulsed engines are unable to evacuate the combustion products in a short time moment, thus limiting the firing speed. [0012] Furthermore, as internal pressure in the combustion chamber increases, higher fuel and oxidizer inlet pressures are required to introduce fuel and oxidizer into the combustion chamber, requiring heavier weight pumps that operate at higher horsepower. One example of such limitations on present engines is seen in the phase two main space shuttle engine. The engine requires 108,400 horsepower to drive the fuel and oxidizer pumps alone. Inlet pressures exceed 6,800 psi in order to obtain an internal combustion chamber pressure to only 3,260 psi with a combustion chamber to nozzle ratio of 77 to 1. [0013] The huge plume of fire trailing the shuttle and other rockets is caused by incomplete combustion of the fuel and oxidizer prior to exiting the exhaust nozzle. The fuel and oxidizer igniting outside the engine provide virtually no thrust and are thus wasted. The above space shuttle engine example requires 2,000 pounds of fuel and oxidizer per second to obtain 418,000 pounds thrust at sea level. Furthermore, the continuous ignition of present engines causes high heat transfer to engine parts, particularly the nozzle orifice, and the high heat transfer requires the use of costly exotic materials and intricate cooling schemes to preserve the engine structure. [0014] Prior efforts to improve the engine design focus on various components, including the nozzle. For example, U.S. Pat. No. 6,003,301 to Bratkovich et al., entitled “Exhaust Nozzle for Multi-Tube Detonative Engines” teaches the use of a nozzle in an engine having multiple combustor tubes and a common plenum communicating with the combustor tubes. Accordingly, Bratkovich et al. teach that the common plenum and a compound flow throat cooperate to maintain a predetermined upstream combustor pressure regardless of downstream pressure exiting the expansion section. [0015] While the prior art addresses many aspects of propulsion devices, it does not teach the use of a shaped charge in a jet or rocket engine. A shaped charge is generally defined as a charge that is shaped in a manner that concentrates its explosive force in a particular direction. While the general theory behind shaped charges has been known for many years, the prior art has restricted the use of shaped charges to warheads and certain other expendable detonation devices. In a typical warhead, the shaped charge directs its explosive forces forwardly, in the direction the warhead is traveling, by igniting moments before or substantially simultaneously with impact. The highly concentrated force can be used to create a cheap, lightweight armor-piercing device. Examples of shaped charge devices are described in U.S. Pat. No. 5,275,355 to Grosswendt, et al., entitled “Antitank Weapon For Combating a Tank From The Top,” and U.S. Pat. No. 5,363,766 to Brandon, et al., entitled, “Ramjet Powered, Armor Piercing, High Explosive Projectile.” Shaped charges in such devices are not used to provide propulsion. [0016] Similarly, current engines configured to drive a turbine do not employ shaped charge engines. One example of a pulsed turbine engine is disclosed in U.S. Pat. No. 6,000,214 to Scragg, entitled “Detonation Cycle Gas Turbine Engine System Having Intermittent Fuel and Air Delivery.” Scragg teaches a detonation cycle gas turbine engine including a turbine rotor within a housing. Valveless combustion chambers are positioned on either side of the rotor to direct combustion gases toward the turbine blades. The two combustion chambers alternately ignite the mixture of fuel and oxidizer to cyclically drive the turbine. While Scragg discloses a useful engine, efficiency, horsepower per unit of engine weight, and other performance parameters could be greatly improved. For example, the Scragg device constructed to deliver 200 hp would require a 560 cubic inch combustion chamber and would weigh 262 pounds, while a 200 hp engine using a shaped charge as in the present invention would require a combustion chamber of only 18 cubic inches and would weigh only 70 lbs. [0017] There is therefore a need for a shaped charge propulsion device that provides substantially improved performance than prior art devices. SUMMARY OF THE INVENTION [0018] The present invention provides a shaped charge engine that overcomes many limitations of the prior art. The apparatus includes a blast-forming chamber comprising an inner annular charge forming housing having a conical convex projection that forms the inner walls of the blast-forming chamber. A central through hole is provided to allow exhaust gases to exit. An outer housing comprises a generally round disk with an inner conical concave depression and through holes for the insertion of fuel and ignition. The two housings are joined by conventional means such as welding or bolts. The resulting chamber formed by joining the two housings is taper-conical in shape, wider at the base, and gradually decreasing in cross-sectional area as it rises to the apex. This construction forms a circular pinch point or throat toward the apex that forms the primary or first stage compression area. A secondary compression zone is created at the apex of the outer housing, just beyond the throat. Hypersonic gases exit the through hole in the inner housing. [0019] In accordance with further aspects of the invention, a directed thrust is formed in a pulsed manner using a contained burn that starts at a peripheral base area and is directed in a tapered-conical shape that forms a primary compression area adjacent the apex of the conical shape. The compressed burn thereafter continues to the apex of the tapered-conical shape, creating a high-speed convergence or secondary compression zone before being exhausted. This construction provides a more complete ignition within the chamber, enhancing efficiency by capturing more of the energy before it leaves the engine. It also allows for the combustion products to exit the primary combustion chamber more rapidly, thus allowing a higher pulse rate of firing while maintaining the high compression exhaust flows by not compressing exhaust products to final velocity internally. [0020] In accordance with other aspects of the invention, the engine includes a sensor to determine the ambient air density, allowing the engine to selectively consume air or oxidizers, as appropriate. [0021] In accordance with still further aspects of the invention, inexpensive conventional fuels, such as gasoline, acetylene, butane, propane, natural gas, and diesel oil are mixed with air or an oxidizer into a combustible mixture and infused under positive pressure into the hollow blast-forming chamber in a manner that permits positive shutoff between a series of induction cycles to accommodate ignition cycles. [0022] In accordance with yet other aspects of the invention, an igniter ignites the combustible mixture initiating a blast wave or pulse at the base of the hollow blast-forming chamber. As the blast wave or pulse advances into a gradually compressed blast-forming chamber, additional mass may be injected into the blast chamber, thereby increasing the momentum of the blast wave. Explosion products are compressed by the gradually decreasing cross sectional area of the blast-forming chamber. The increasing pressure drives the blast wave into a primary compression zone formed by an annular restriction between the truncated end of a central conical projection and an opposing truncated hemispherical or domed inner surface of the outer housing. [0023] Compression of the blast wave into this annular restriction creates a high-speed radial flow of explosion products toward the center of the truncated hemispherical or domed surface. The opposing high-speed radial streams of explosion products converge at the center of the truncated hemispherical or domed surface creating a secondary zone of increased compression of the explosion products. Confluence of mass and kinetic energy in the secondary compression zone forms the explosion products into hypersonic gases that exit in a controlled blast directed through an exhaust port centrally located at the apex of the central conical projection. The resulting high pressure hypersonic exhaust is expelled in a directed blast from the exhaust port without the need for an exit nozzle. [0024] In accordance with still another aspect of the invention, the exit velocity of the combustion products and ejecta is controlled by increasing or decreasing the size, length, diameter, and depth angle of the blast chamber, and adjusting fuel-oxidizer mixtures. [0025] In accordance with still further aspects of the invention, the controlled blasts formed in the blast-forming chamber are repeatable by the serial infusion and ignition of additional charges of the combustible mixture. Furthermore, in repeating pulsed modes, the blast power and frequency are throttle controllable by increasing or decreasing the flow rate of the combustible mixture or adjusting the cycle rate independently of the mixture flow rate. [0026] In accordance with yet another aspect of the invention, the engine is operated in a pulsed mode along a continuum between an aerobic or air-breathing jet mode and an anaerobic or non-air-breathing rocket mode. Accordingly, fuel is mixed with air, oxidizer, or any combination of the two in any relative concentration. The relative concentrations of air and oxidizer in the combustible mixture is dynamically adjusted into a blend of air and oxidizer, which may be a function of oxygen concentration in the ambient atmosphere. [0027] In accordance with further aspects of the invention, the particular geometry of the shaped charge engine may be varied, while still retaining the inventive aspects, including primary and secondary convergence zones. Accordingly, the cross-sectional shape may be annular, square, rectangular, triangular, or a variety of other forms depending on the desired results and the space available to house the engine in the vehicle to be propelled. [0028] In accordance with still further aspects of the invention, the exhaust gases collide at a secondary convergence zone to create hypersonic exhaust. The opposing streams of gases may originate in chambers that are substantially opposite one another and at least partially orthogonal to the direction of travel. Alternatively, the blast chamber may be configured such that the explosive products travel in an acute or an obtuse angle with respect to the direction of travel before reaching the throat and the secondary compression zone. [0029] In accordance with additional aspects of the invention, the angle at which the exhaust gases converge may be dynamically controlled during operation of the engine. The generally opposed sides of the generally annular blast-forming chamber may be hinged to allow the chambers to be moved fore and aft to adjust the angle of convergence. [0030] In accordance with yet other aspects of the invention, the cross-sectional area of the throat or pinch point may be increased or decreased. By decreasing the size of the throat area, the exhaust gases travel at a higher velocity, creating a relative spike in the exhaust velocity and therefore the thrust. Conversely, by increasing the throat size, the exhaust gases exit more uniformly and at a lower relative velocity. [0031] In accordance with other aspects of the invention, the engine may be used to provide direct thrust to propel a rocket, aircraft, personal water craft, or other vehicle. [0032] In accordance with still other aspects of the invention, the exhaust gases created by the engine may be used to drive a turbine that is used to propel the vehicle. In such an embodiment, the engine may, for example, be used to power a car. [0033] In accordance with still further aspects of the invention, the pressure, exhaust, pulse, or heat produced by the shaped charge engine may be used in a wide variety of applications, including, for example, vehicle propulsion, pest control, demolition, cutting tools, etching tools, heating tools, spraying tools, high-speed guns, generators, boilers, and closed-system pressure devices. BRIEF DESCRIPTION OF THE DRAWINGS [0034] The preferred embodiment of the present invention is described in detail with reference to the following drawings. [0035] [0035]FIG. 1 is a cross-sectional view of a shaped charge engine, including a blast-forming chamber, formed in accordance with a preferred embodiment of the present invention; [0036] FIGS. 2 A-C is a cross-sectional view of several representative shapes of a blast-forming chamber formed in accordance with the present invention; [0037] FIGS. 3 A-C is a cross-sectional view of several representative orientations of a blast-forming chamber formed in accordance with the present invention; [0038] [0038]FIGS. 4A and 4B are cross-sectional view of two alternate configurations for the throat of an engine formed in accordance with the present invention; [0039] [0039]FIG. 5 is a representative view of a switchable jet and rocket engine formed in accordance with the present invention; [0040] [0040]FIG. 6 is a representative view of a pulse driver engine formed in accordance with the present invention; [0041] [0041]FIG. 7A is a side view of a rotary centrifugal throttle valve formed in accordance with the present invention, and [0042] [0042]FIG. 7B is a top view of rotary centrifugal throttle valve formed in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0043] General Construction of the Shaped Charge Engine. FIG. 1 schematically illustrates in cross-section a device constructed in accordance with the present invention for dynamically compressing and detonating a combustible mixture to form a shaped compression wave. Reference numeral 10 generally refers to a shaped charge engine. The engine 10 includes a hollow blast-forming chamber 3 formed between an outer charge forming housing 2 and an inner charge forming housing 1 . The outer charge forming housing 2 is generally round-conical in shape and includes a centrally located dome shaped portion at the apex to form a concave “cup” or “bowl” shape. [0044] The inner charge forming housing 1 comprises a generally flat plane transitioning to a centrally located generally conical-shaped projection 7 . The projection 7 extends radially inward and upward toward the outer housing 2 . The projection 7 is truncated below the tip to form a centrally located generally circular opening at the smaller end of the cone which is nearest the outer housing 2 when the inner housing 1 and outer housing 2 are joined. From the perspective of exhaust gases E traveling from the tip of the projection 7 through the opening and out the engine, the projection 7 thus forms a generally cylindrical opening that flares outward into a generally conical opening at the exit. [0045] The inner charge forming housing 1 is joined to the outer charge forming housing 2 so that the projection 7 extends toward the outer housing 2 . The outer charge forming housing 2 and inner charge forming housing 1 are joined along their respective outer peripheral edges to form hollow blast-forming chamber 3 in the space between the inner housing 1 and outer housing 2 . The inner and outer charge forming housings 1 and 2 are joined, for example, by a weld 6 , or by other compression means such as bolts or rivets. [0046] The housings 1 and 2 are formed of materials capable of withstanding the heat and pressure of the ignition, detonation, and compression of the controlled combustion. Any of a variety of materials typically used in the construction of rocket engines may be used for the present invention, including, for example, steel, stainless steel, or titanium. Preferably, the material of inner charge forming housing 1 is sufficiently thick to withstand the heat and pressure without external support. [0047] A plurality of fuel injectors 5 and igniters 4 project through the outer housing 2 and into the chamber 3 . The injectors 5 infuse fuel, air, and oxidizer into hollow blast-forming chamber 3 . The preferred combustible mixture is, for example, formed of any conventional fuel that, when mixed with air, oxidizer, or a combination of both, forms a combustible mix. The fuel is optionally any airborne combustible material such as Hydrogen or other flammable gases; an inexpensive liquid spray such as butane, propane, gasoline, acetylene, or natural gas; a combination of vapor and liquid drops such as diesel oil; airborne solid particles; or another combustible mixture that burns rapidly enough to accomplish dynamic compression and detonation. The fuel is preferably mixed with a proportioned amount of air or oxidizer for complete combustion. [0048] The igniter 4 is, for example, a conventional spark plug powered by a spark generator, glow-plug, piezo-electric spark gap or another suitable ignition device. In accordance with alternate embodiments of the invention, the igniter 4 is a hot plasma jet generated by a plasma jet generator (not shown) and directed into the ignition region of the hollow blast-forming chamber 3 . Other fast and reliable devices for injecting flames or sparks essentially instantaneously into the ignition region are within the scope of the present invention as alternative ignition devices. [0049] While the injector and igniter are preferably constructed such that they project through the outer housing 2 into the blast-forming chamber, either or both of the injector 5 and igniter 4 may be peripherally mounted in the inner charge forming housing 1 or in the space separating the inner and outer housings 1 and 2 (i.e., along the weld 6 ), so long as they extend into the ignition region of the hollow blast-forming chamber 3 . [0050] The combustible mixture injector 5 is any conventional injection system suitable for providing a controllable flow of the combustible mixture, including, for example, conventional fuel injectors and carburetors. Conventional carburetors used in conjunction with turbochargers allow the mixing of a wide variety of fuels with air for injection into the hollow blast-forming chamber 3 . [0051] The timing of the fuel injection and ignition, and therefore the timing of the combustion, is controlled by a control system (not shown) including fuel, air, and oxidizer valves. A valve port is formed at the combustible mixture injection point if a carburetor or pressurized bottled or liquid fuel is used to practice the invention. A valve for the valve port is operated to admit the combustible mixture into the hollow blast-forming chamber 3 . The valve is a solenoid valve in each case, although other valves may be used, such as any of a rotary, disc, poppet or drum valve or any other device that allows air, oxidizer and fuel to be injected into the chamber 3 under positive pressure and that allows for a positive shutoff between induction cycles to accommodate the ignition cycle. If necessary, increased pressure from combustion in the hollow blast-forming chamber 3 operates over an area of the valve to close the valve and limit ignition injection into the carburetor. [0052] The blast-forming chamber 3 includes only a single annular opening at the center. This opening comprises the area between the inner housing projection 7 and the outer housing 2 . The substantially restrictive opening creates a restrictive pinch point that forms a primary or first stage compression area. A high-speed convergence or secondary compression zone 9 is created at the apex of the outer housing 2 generally at the center of the annular region defining the throat and substantially along the axis of the inner and outer housings 1 and 2 . [0053] General Operation of the Shaped Charge. The outer charge forming housing 2 is adapted to accept the introduction of a combustible mixture into the hollow blast-forming chamber 3 near the outer periphery of the base of the hollow blast-forming chamber 3 . The blast-forming chamber is larger in cross-sectional area, at least relative to the throat, at the location of fuel injection and ignition. Because multiple fuel injectors 5 and igniters 4 are spaced along the periphery of the inner and outer charge forming housings 1 and 2 , there are several locations within the chamber 3 at which combustion takes place. Preferably, combustion occurs at generally opposing sides of the chamber 3 . [0054] In an embodiment in which both air and oxidizers are both available, for example a combined jet/rocket engine, air is burned with fuel in sufficiently dense atmospheres to accommodate the fuel load while air is available. An air mass sensor (e.g., hot wire anomometry) or other sensor is coupled to a controller (not shown) that determines the amount of air available. The controller causes the inlet RAM port to open as air mass decreases so that sufficient oxygen enters the chamber 3 . After the controller determines that air mass is too low, the air inlet stays open and the oxidizer port begins to open, causing oxidizer to enter the chamber 3 . During the transitional period in which air is available but either not ideal or sufficient, both air and oxidizer are used. When the air density is too low, the outside air inlet closes and oxidizer alone is used for combustion. Thus, the device is operated aerobically in a jet mode, anaerobically in a rocket mode, or in any of combination of jet and rocket modes. [0055] The igniters 4 and injectors 5 are located near the periphery of the blast-forming chamber 3 , causing ignition to be started relatively near the periphery of the annular chamber 3 . Because multiple igniters 4 are spaced around the chamber, ignition also takes place substantially simultaneously at several locations around the chamber. Each of the multiple injectors 5 simultaneously injects an appropriate amount of the combustible mixture into the chamber 3 under positive local pressure relative to the pressure inside the remainder of the hollow blast-forming chamber 3 . The injector 5 is sealed or closed following the injection cycle, creating a barrier or block between the hollow blast-forming chamber 3 and the fuel and the air or oxidizer. [0056] After sealing the injectors 5 , each of the multiple igniters 4 essentially simultaneously ignites the charge of combustible mixture, causing the detonation (or pulse) along essentially the entire outer circumference of the base of the hollow blast-forming chamber 3 . As the flame front or pulse advances toward the apex of the hollow blast-forming chamber 3 , additional mass can be injected into the chamber 3 to increase the mass and therefore the momentum of the blast wave. Preferably, the injected mass is a safe mass such as water or an inert slurry, although the mass may alternatively be a combustible mass, including additional fuel. The explosion products are increasingly compressed by the gradual reduction in cross sectional area at the throat, or the apex of hollow blast-forming chamber 3 . As the flame front advances toward the throat, primary or first stage compression is achieved by back pressure forcing the flame front essentially simultaneously into all areas of the throat. This forcing of the flame front through the throat creates a high-speed inwardly radial flow of explosion products toward the apex of the inner surface of the outer charge forming housing 2 . [0057] The high-speed explosion products stream exits the chamber through the throat and advances inwardly causing high-speed gases to converge near the inner surface 8 and at the center line 9 of the outer charge forming housing 2 . The convergence creates, by the confluence of mass and kinetic energy, a secondary compression zone that forms the explosion products into hypersonic gases before their exhaustion in a controlled blast directed through the exhaust port. The resulting high pressure hypersonic exhaust E is expelled in a directed blast from the exhaust port without the need for an exit nozzle. The above description represents a single firing cycle, which is useful in many applications. The engine may alternatively be operated in a pulsed mode by repeating the above firing cycle. [0058] The shaped charge engine is controllable using a throttle that may vary the fuel, air, and oxidizer volume. In a typical rotating disk valve that serves as a throttle, two holes are spaced 180 degrees apart to allow for injection of fuel only when the holes are aligned with the fuel lines as the disk rotates, for example at 100 RPM. As the disk rotation speed increases, the time moment of hole alignment decreases, providing a smaller amount of fuel to be injected per pulse. Conversely, decreasing the rotation rate will cause greater amounts of fuel to be injected per pulse. [0059] Alternate Embodiments of the Shaped Charge Engine. While the general construction and operation of the shaped charge engine of the preferred embodiment is discussed above and shown in FIG. 1, the construction may be varied, consistent with the present invention. In certain applications, it may be desirable to construct the shaped charge engine with an alternate geometric shape. For example, with reference to FIG. 2, the cross-sectional geometric shape may be varied in alternate embodiments. The generally circular or annular shape depicted in FIG. 2A corresponds to the circumference of the blast chamber 3 of the preferred embodiment shown in FIG. 1. Alternate embodiments are depicted in FIGS. 2B and 2C, showing rectangular and triangular designs, respectively. [0060] The design of the preferred embodiment, shown in FIG. 2A, is an ideal shaped charge engine having exhaust products that converge at the center simultaneously. The rectangular embodiment of FIG. 2B is somewhat less efficient but still produces exhaust products that collide substantially simultaneously because exhaust products travel like distances from opposing sides before reaching the secondary compression zone. The triangular embodiment of FIG. 2C is quite inefficient, with uneven distances from the periphery of the combustion chamber 3 to the secondary compression region, producing lower exhaust velocities and less thrust than the circular embodiment of FIG. 2A. Still other shapes of a generally convex polygonal nature may be used, consistent with this invention. [0061] Just as the cross-sectional shape of the blast-forming chamber 3 may be varied, so may the orientation of the blast-forming chamber be altered. The general orientation of the preferred embodiment is depicted in FIG. 3A. In the embodiment of FIG. 3A (which may be characterized as “concave”), the exhaust products travel toward the throat from a point generally upstream of and somewhat orthogonal to the final exhaust direction. As the exhaust products pass through the throat, they collide with the outer housing 2 and gases emerging from opposite sides at the secondary compression zone, producing hypersonic exhaust in a direction somewhat opposite the direction of travel through the throat. [0062] In an alternate embodiment, as depicted in FIG. 3B, the blast-forming chamber is substantially flat, so that the exhaust products travel through the throat in a direction generally orthogonal to the final exhaust direction. In yet another embodiment, as depicted in FIG. 3C, the blast-forming chamber is in a convex configuration, so that the exhaust products travel through the throat in a direction that forms an obtuse angle with the final exhaust direction. Likewise, additional orientations not depicted in FIG. 3 are possible. [0063] Among the three embodiments depicted in FIG. 3, the embodiment of FIG. 3A can be considered a high pressure spike motor. The change in direction of the exhaust gases just beyond the throat causes “thermal stacking” of the gases just prior to exit. The result produces a powerful but brief spike of thrust as the gases exit the engine. While the total masses of exhaust products are the same in each embodiment, the thrust characteristics differ. Thus, the embodiment of FIG. 3B will produce a relatively weaker, longer thrust moment, while the embodiment of FIG. 3C will produce a more even exhaust flow with a relatively smaller spike. [0064] Depending on the environment and desired performance, it may be useful to construct a single engine in which the blast chamber orientation can be dynamically varied from a convex orientation (such as in FIG. 3C) to a concave orientation (such as in FIG. 3A). In the preferred embodiment, particularly when used as a pulse jet/rocket engine as discussed further below with reference to FIG. 5, the shaped charge engine may be hinged and dynamically adjustable to create varying blast chamber orientations. [0065] With reference again to FIGS. 3 A-C, outer housing hinge points H 1 , H 2 are indicated at locations that allow for adjustment of the orientation of the shaped charge engine. Thus, by pivoting the outer housing 2 at the location of the outer housing hinge points H 1 , H 2 , the orientation of the shaped charge engine may be changed along a continuum from a generally convex orientation (such as in FIG. 3C) to a concave orientation (such as in FIG. 3A). Because the blast chamber 3 is preferably a continuous annular ring, the inner and outer housings 1 , 2 comprise a series of plates arranged to slide over and under one another as the configuration changes. Alternate constructions are also possible, including for example a combustion chamber that comprises a plurality of separate sub-chambers that are adjoining or nearly adjoining one another at the most concave and convex positions (as in FIGS. 3A AND 3C) but that are spaced relatively farther apart from one another in the more horizontal configurations as in FIG. 3B. [0066] The throat area may also be varied, consistent with the invention. With reference to FIG. 4, two alternate embodiments are shown. In FIG. 4A, a low pressure engine is shown having a relatively larger throat. Alternatively, the embodiment of FIG. 4B includes a relatively smaller throat. Relative to the engine of FIG. 4B, the engine of FIG. 4A will create lower pressure in the combustion chamber 3 , lower velocities through the throat, and a smaller spike in exhaust velocity and thrust. [0067] Again with reference to FIGS. 3 A-C, outer housing hinge points H 3 , H 4 are indicated at positions that allow the inner housing 1 to be adjusted swing closer or farther from the outer housing 2 . Thus, as the inner housing 1 is pivotally moved toward the outer housing 2 , the size of the throat is decreased, producing a smaller “pinch point.” Conversely, the inner housing 1 can be rotated outward, away from the outer housing 2 , producing a larger throat. In the case of both the adjusted orientation and adjusted throat area, the hinging action is best accomplished by hydraulics, screw-drive, or other such devices that can move metal plates and withstand the substantial pressures produced in the blast-forming chamber 3 . [0068] Use as a Switchable Pulsed Jet/Rocket Engine. A presently preferred application of the shaped charge engine is depicted in FIG. 5, which schematically illustrates a switchable pulsed jet/rocket engine. The switchable pulsed jet/rocket engine of FIG. 5, generally indicated by reference numeral 100 , includes a shaped charge engine in accordance with that of FIG. 1, although it is shown in a concave orientation as in FIG. 3C. [0069] The engine begins operation from a cold start at low altitudes in a pulsed jet mode. Pulses of fuel and oxidizer are fed from sources of fuel 101 and oxidizer 108 to the shaped charge combustion chamber 106 via separate fuel and oxidizer lines 102 , 110 , each of which is controlled by a solenoid valve 104 b , 104 c . An igniter 112 ignites the fuel and oxidizer mixture, creating a blast and attendant high pressure within the chamber 106 . When the rotary valve is in use (principally in jet mode), the igniter is controlled by a fixed timing ignition device such as, for example, points typically found in an automobile distributor, magneto or battery assisted magnetic pickups, or light sensitive relays. When direct fuel and oxidizer injection are used (in rocket mode), the igniter is controlled by computer processor initiated timing pulses. [0070] By opening a solenoid valve 104 a on an exhaust bypass line 114 , pressurized exhaust products are allowed to flow to an exhaust-driven turbine 116 , causing it to rotate. The exhaust-driven turbine 116 is connected to a compressor 118 , a fuel pump 120 , and a centrifugal throttle valve 122 , each of which is configured to rotate together as a unit. While an ordinary rotating disk may be used consistent with this invention, in the preferred embodiment the centrifugal throttle valve 122 (discussed in greater detail below with reference to FIG. 7) is used to provide superior control, particularly in fixed inlet pressure conditions. As the unit rotates, compressed air 126 collected via an air scoop 128 is delivered through an air line 130 while fuel is delivered via a fuel line 132 to the centrifugal throttle valve 122 . The centrifugal throttle valve 122 allows air and fuel to pass through the valve by opening and closing multiple apertures that are cyclically aligned and mis-aligned as it rotates. [0071] Fuel and air, after passing through the centrifugal throttle valve 122 , are mixed in a mixing manifold 134 and injected into the shaped charge combustion chamber 106 when the centrifugal throttle valve 122 is opened. The centrifugal throttle valve 122 then closes and the igniter 112 ignites the fuel and air (or oxidizer) mixture within the chamber 106 at an ignition point 113 . The detonation causes exhaust products to travel out the chamber 106 . [0072] The preferred centrifugal throttle valve is shown in side view in FIG. 7A and plan view in FIG. 7B. Previous rotary disk valves having fixed opening sizes such as are used in prior variable firing rate engines suffer many problems, regardless of the size or shape of the openings. For example, if the port is sized for low rate firing then the time during which the openings are aligned decreases as rotation increases, allowing less air, fuel, or mixture to pass through the valve per pulse. Consequently, higher inlet pressure is required to obtain the correct charge volume. On the other hand, if the port is sized for high rate firing, then at low firing rates the disk spins slower, the holes are aligned for longer periods, and an excess amount of air, fuel, or mixture is allowed to pass through the valve. In order to compensate for the excess and obtain the correct charge volume, lower inlet pressures and controls are required. [0073] The rotary centrifugal throttle valve 122 overcomes these problems and allows for correct charge volumes at all firing rates while using a fixed inlet pressure. The centrifugal throttle valve 122 includes a driveshaft 172 having a projection 174 and a disk valve housing 176 mounted on the driveshaft 172 . The disk valve housing 176 comprises two halves 176 a , 176 b joined together in conventional means such as welding, lamination, bolts, or screws 184 . The two halves 176 a , 176 b of the disk valve housing 176 include recessions that, when the halves are joined, together form inner pockets 178 a , 178 b . The disk valve housing 176 also includes one or more openings 182 a , 182 b passing through the disk valve housing 176 substantially overlying the inner pockets. A sliding valve 179 a , 179 b is retained within each of the pockets 178 a , 178 b . A further recession within the two halves 176 a , 176 b of the disk valve housing forms spring pockets 181 a , 181 b that retain springs 180 a , 180 b associated with each sliding valve 179 a , 179 b . Other devices may be used in the place of the springs 180 a , 180 b to bias the sliding valves 179 a , 179 b in a closed position at slower rotation speeds, including other resilient materials or compression devices. Still further, the sliding valves 179 a , 179 b may be electronically controlled using hydraulics, worm-drives, or other mechanisms to open and close the valves as a function of rotation rate. While the centrifugal throttle valve 122 is illustrated as having two openings 182 a , 182 b , any number of openings may be used, consistent with the invention. Likewise, the openings 182 a , 182 b are illustrated as having a generally “pie” shape, but may be round, square, or any other shape. [0074] With reference more particularly to FIG. 7B, the operation of the centrifugal throttle valve is illustrated, representationally both at high and low firing rates. At low firing rates, the disk valve housing 176 rotates at a relatively lower rate, causing the spring 180 b to urge the sliding valve 179 b in a direction radially inward within the pocket 178 b . By moving toward the center of the disk valve housing 176 , the sliding valve 179 b covers a substantial portion of the opening 182 b , limiting the amount of air, fuel, or mixture that may pass through to the combustion chamber. Note that the openings 182 a , 182 b are preferably formed so that the sliding valves 178 a , 178 b cannot fully cover them even when the centrifugal throttle valve 122 is stopped or at its slowest rate of rotation. This arrangement allows air, fuel, or mixture to reach the combustion chamber during start-up and prevents the engine from stalling at the lowest firing rates. [0075] At relatively higher firing rates, centrifugal forces cause the sliding valve 179 a to compress the spring 180 a farther within the spring housing 181 a . The recession of the spring radially outwardly uncovers a substantial portion of the opening 182 a , allowing a greater amount of fuel, air, or mixture to pass through to the combustion chamber. In any particular application, the throttle valve may be tailored by substituting springs of greater or lesser resistance, altering the opening size or shape, locating the openings farther inward or outward along the disk housing radius, or increasing or decreasing the number of openings on the disk valve housing 176 . [0076] While the above discussion and illustration in FIG. 7B depicts one opening 182 a substantially uncovered by the sliding valve 179 a as would be the case at a high firing rate, and one opening 182 b substantially covered by the sliding valve 179 b as would be the case at a low firing rate, this condition is shown on a single valve only for ease of illustration and discussion. In practice, each of the openings 182 a , 182 b would be covered or uncovered by the sliding valves 179 a , 179 b to substantially the same extent at all times. [0077] The projection 174 on the driveshaft 172 is shown as a triangle shape, offset from the center of the driveshaft 172 . The projection 174 may alternatively be of any shape, although an irregular shape is preferred to prevent joining the driveshaft 172 to the disk housing 176 out of phase with ignition or other external parts that require timing. The driveshaft 172 is joined to the disk housing 176 by inserting the projection 174 into a similarly shaped recession 184 within the disk housing 176 . The projection 174 and recession 184 are configured to allow the projection 174 to slide within the recession 184 , permitting the disk housing 176 to move inward or outward along the shaft 172 . A thrust washer 186 absorbs the force imparted on the disk housing 176 and ensures a tight seal. This construction allows the centrifugal throttle valve to absorb substantial pressures without damaging the drive motor or other components. Moreover, the sliding arrangement of the projection 174 within the recession 184 allows for wear on the thrust washer. [0078] As the turbine 116 , compressor 118 , fuel pump 120 , and centrifugal throttle valve 122 continue to rotate, pulses of the fuel and air mixture are continually produced and ignited as described above. The solenoid valve 104 c associated with the exhaust bypass line 114 is modulated (or pulsed) to produce the desired idle speed of the turbine and the engine itself. [0079] The air scoop 128 is opened or closed automatically via a linear actuator 136 . The linear actuator 136 is controlled by an air mass sensor 138 that, as discussed above, determines the air mass available. In the preferred embodiment, the air mass sensor 138 essentially comprises a heated wire that decreases in temperature as increased air mass flows over the wire during flight. The temperature of the wire is read by a processor (not shown) to determine the magnitude of the existing air mass. Thus, the linear actuator 136 can, for example, open the air scoop 128 when the air mass sensor 138 senses a reduced air mass available, causing more air volume to enter the intake air plenum 140 . [0080] With the engine at idle, the switchable pulsed jet/rocket is ready to transition to a pulse jet mode of operation in which substantial thrust is produced. The solenoid valve 104 c on the exhaust bypass line 114 is opened substantially fully, allowing more exhaust gas to flow through the line to drive the turbine 116 , causing it to rotate faster. In turn, the compressor 118 , fuel pump 120 , and centrifugal throttle valve 122 rotate faster. Because of the centrifugal forces produced by the faster rotation, the centrifugal throttle valve 122 automatically opens the valve aperture opening to allow higher air and fuel flows required at rapid pulse rates. [0081] The high pulse rate fuel and air charges that are ignited by the timed ignition of the igniter 112 causes detonation wave exhaust streams to flow from the ignition point 113 within the combustion chamber 106 . The exhaust streams flow through the low pressure pinch point at the throat 142 and converge at a secondary high pressure compression point 144 from which they exit as a high pressure hypersonic exhaust flow in the direction of the arrow 146 . The engine is now operating at the highest thrust setting possible using air and fuel as the inertial mass (and without altering the shape or orientation of the combustion chamber 106 ). [0082] Greater thrust can be obtained by adding additional mass to the combustion chamber 106 . As noted previously, the additional mass is preferably a safe mass such as water or an inert slurry. The additional mass products from the mass injection manifold 148 are injected into the chamber 106 by opening a solenoid valve 104 d located on an additional mass line 150 . The additional mass is injected into the chamber 106 between pulses and prior to firing of the igniter 112 . The exhaust stream automatically accelerates the additional mass out the chamber 106 . The engine is now at an ultra-high thrust setting; that is, the maximum thrust that can be achieved using fuel, any combination of air and oxidizer, and added mass to produce thrust in the configuration and orientation of the engine. [0083] As the atmosphere thins, the pressure in the air intake plenum 140 diminishes and is sensed by the air mass sensor 138 . The air scoop 128 is automatically opened by extending the linear actuator 136 , causing the air scoop 128 to pivot on a hinge point 152 . The additional volume of air increases the pressure in the plenum 140 to satisfy the oxygen requirements of the engine until the air scoop 128 is opened to its widest position. As the atmosphere thins further, the air scoop cannot admit a greater flow of air. A computer controller (not shown) coupled to the air mass sensor 138 , upon determining that the air scoop 128 is open at its widest and the air is too thin, causes one or more oxidizer valves 154 to open to allow oxidizer to flow into the chamber 106 . While the oxidizer valves 154 are preferably driven by a controller containing a processor, they may alternatively be driven directly by proximity switches associated with the air mass sensor 138 and linear actuator 136 . The oxidizer valve 154 allows an increasing amount of oxidizer to be injected into the blast chamber 106 as the atmosphere thins even further. [0084] When no air or atmospheric pressure is sensed by the air mass sensor 138 , the engine operates in an anaerobic mode essentially as a space vehicle. The solenoid valve 104 c on the exhaust bypass line 114 closes, causing the turbine 116 , compressor 118 , fuel pump 120 , and centrifugal throttle valve 122 to stop rotating. Likewise, because there is no air available, the air intake scoop 128 is closed by retracting the linear actuator 136 . [0085] Fuel and oxidizer are fed directly to the combustion chamber 106 via the fuel line 102 and oxidizer line 110 by timed pulses of the solenoid valves 104 a , b. All other operations of the ignition, injection of mass, and exhaust are the same as in the air-breathing mode of operation. [0086] When air becomes available as the engine descends, the air mass sensor 138 detects the increased presence of air and allows the air scoop 128 to open so that an aerobic, or jet, mode of operation can again take place. [0087] Hinged and gimbaled operation. In the preferred embodiment of the present invention, the shaped charge engine is hinged so that the orientation of the combustion chambers can be dynamically altered during flight. Such a construction is discussed above with reference to FIGS. 3 A-C. [0088] In addition, the engine can be gimbaled to allow the direction of the exhaust products to be controlled. The outer engine is pivotally mounted on the air/space craft so that the exhaust stream can be directed. By pivoting the engine, and therefore the exhaust stream, the engine itself provides directional control. In alternate embodiments, the blast-forming chamber 3 may be pivotally mounted while the remainder of the propulsion and control system is fixed. In still another alternate embodiment, directional control can be obtained by adjusting the inner and outer housing hinges H 1 , H 2 , H 3 , H 4 in an asymmetrical fashion. Thus, for example, the outer housing hinges H 1 , H 2 can be adjusted to produce a blast-forming chamber having opposing sides that are in slightly different orientations. Likewise, for example, the inner housing hinges H 3 , H 4 can be adjusted to produce a throat that is imbalanced on opposing sides. In either configuration, the exhaust stream will be directed off-center, providing directional control. [0089] Use as a Pulse Driver for Other Vehicles. While the shaped charge engine of this invention is described above as suitable for air-breathing and non-air-breathing applications, it can also be adapted for use in applications that always have air available. For example, the shaped charge engine may propel a car or boat, may be used in a tool or as a generator, or may be used in many other applications that will have air available. The general construction of the shaped charge engine for use in such atmospheric conditions is shown in FIG. 6. The atmospheric engine includes one or more air intake ports 201 leading to a compressor 202 . The compressed air is passed through air outlet ports 203 to the combustion chamber 206 via engine air inlet ports 204 . Fuel from a fuel source (not shown) is injected via fuel injectors 205 . [0090] In the same manner as discussed above, the engine includes a primary low pressure pinch point at the throat 207 leading to a secondary high compression point 208 that produces a high pressure exhaust stream 209 . The fuel and air mixture is ignited by an igniter 212 that is illustrated as a spark plug. A drive motor (not shown) is connected to a drive shaft 215 via a key way or spline 216 . In turn, a valve drive extension 214 on the drive shaft 215 is connected to a rotary centrifugal throttle valve that operates as described above with reference to FIG. 8. [0091] The primary difference between the shaped charge engine of FIG. 6 and the pulsed jet/rocket engine of FIG. 5 is the inclusion of oxidizer and the ability to open and close air intake scoops. In all other relevant respects, the engines of FIGS. 5 and 6 are constructed and operate in a similar manner. [0092] Use as a Turbine Driver. The shaped charge engine has been described above as a direct propulsion device. Alternatively, the high compression, high inertia exhaust stream can drive fixed cycle or free spinning turbines such as those of the Pelton or axial flow type. One example of a detonation cycle turbine engine is shown in U.S. Pat. No. 6,000,214 to Scragg. Scragg discloses a turbine rotor driven by the exhaust ports of two combustion chambers on opposite sides of the rotor. The torque produced by the acceleration and rotation of the turbine is put to work in conventional electrical or mechanical means. [0093] Similarly, the exhaust of a single or any number of shaped charge engines can be directed toward a turbine. Because the shaped charge engine of the present invention is far more efficient, however, it produces a much improved turbine-driving engine. [0094] Other Uses of the Shaped Charge. As discussed above, the shaped charge engine may be used to propel an aircraft, preferably including an aircraft that may travel in both atmospheric conditions, space conditions, or both. Further, the engine may be used as a direct exhaust drive to propel a personal watercraft, boat, or other vehicle, or may be configured to drive a turbine to propel a car, boat, motorcycle, or other vehicles. In addition, the engine may be used as a bow thruster for boats, ships, or submarines. [0095] In addition to propelling vehicles, the blast or pulse produced by the shaped charge engine is useful in a host of other applications. For example, the shock waves produced by the engine can be used for underground rodent and pest extermination or the control of insects. The shock wave from a single pulse may be used in avalanche control to initiate movement of the potential avalanche, eliminating the need for artillery or explosives. [0096] The shaped charge may also be used for a variety of demolition purposes. For example, it may be used as a rock breaker, to demolish buildings, to fracture rocks in mining, to core and break concrete, or to remove ice from ships, bridges, or roads. In addition, the shaped charge may have military uses as a mine that is both powerful and reusable. Ideally, the material is fragmented by directing one or more shock waves toward it. Moreover, the demolition devices constructed using the present shaped charge invention may be recovered and reused, unlike conventional demolition devices. [0097] A wide range of tools may be created using the shaped charge engine of the present invention. For example, the enormous shock waves produced may be put to use as a jackhammer or other impact tool, or may be focused to produce cutting and etching devices. Hot paint, foam, or metal may be sprayed in an alternate embodiment of the present invention in which paint, foam, or metal is used as the additional mass injected into the blast chamber after ignition. Precisely focused and directed shaped charges may also be used in tree limb removal or weed trimming. Still further, the hot, powerful blasts may be put to use as a burner (such as in a furnace or boiler) or to remove snow from driveways, rooftops, or other locations. Moreover, hot, high pressure exhaust gases may be used to strip paint, varnish, and similar coatings. [0098] In still further applications, a single pulse creates instant heat and pressure for differential pressure forming of metal without the necessity of pre-heating the metal and without requiring compressors or other pressure storage devices. Similarly, pulses may be used to form materials by direct injection devices. [0099] By placing projectiles in the exhaust stream, the shaped charge engine can be used as a high-speed gun. Preferably, a gun barrel or similar launch tube extends from the exhaust port so that the exhaust stream will propel the projectile in a controllable, straight path. [0100] In a closed system, the shaped charge engine may be used to create and maintain pressure, adjusting the magnitude and rate of pulsing to control the pressure. Alternatively, when configured to drive a turbine, the shaped charge engine may form a generator to produce electricity. [0101] Results from Actual Embodiments. As discussed above, serial infusion and ignition of multiple charges of combustible mixture into the hollow blast-forming chamber allow the detonation to be formed in a pulsed manner. The pulse strength and/or frequency is dynamically controlled during operation by varying the quantity and rate of infusing and igniting the serial charges of combustible mixture. Tests of an actual embodiment using the pulsed operation of the hypersonic exhaust stream indicate that operating cycles over 100 Hz and exhaust gas velocities as high as 30,000 feet per second are possible. Thus, independent variation is possible between gentle and powerful pulses and between slow and fast pulse. [0102] As a pulsed jet or rocket engine for aerial vehicles, exhaust gas speeds higher than possible with conventional turbine or rocket propulsion units allow for smaller, lighter drives with fewer moving parts while potentially eliminating turbine blades, compressors, and exhaust nozzles. The pulsed hypersonic exhaust stream also reduces engine cooling requirements by providing pulsed rather than continuous operation. The rapid burning and detonation assist in engine cooling by converting the chemical energy of the combustible mixture quickly into high pressure with little wasted heat. This complete combustion also allows a higher efficiency of the engine and lower fuel use per pound of thrust produced. [0103] An actual embodiment of the present invention has been constructed and tested against a variety of other engines, demonstrating the superior results. An engine capable of delivering 200 horse power (hp) constructed according to U.S. Pat. No. 6,000,214 to Scragg weighs approximately 262 pounds and can produce 0.76 hp per pound of engine weight. An actual embodiment of the present invention that can deliver more than 200 hp weighs only 70 pounds and produces 2.86 hp/pound. The shaped charge engine is also many times smaller, having a combustion chamber of 18 cubic inches compared with 560 cubic inches in a Scragg engine. [0104] The advantages over gasoline, diesel, and Brayton cycle engines are also substantial. In comparison to the actual 200 hp embodiment discussed above, equivalent 200 hp gasoline, diesel, and Brayton engines can produce only 0.40, 0.22, and 1.0 hp/pound, respectively, and weigh approximately 500, 900, and 200 pounds. Consequently, an engine according to the present invention produces significantly more power at a much smaller size and weight than previous engines. [0105] While the preferred embodiment of the invention has been illustrated and described, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.

A shaped charge engine includes multiple blast forming chambers, each chamber having a primary convergence zone that is variably shape to alter the shape of the exhaust gas emanating from each chamber. Thereafter, each chamber's variably shaped exhaust is merged at a secondary convergence zone into a shape further modified to alter the thrust characteristics of the exiting exhaust gases from the shaped charged engine.

FIELD OF THE INVENTION [0001] The invention relates to pulse shaping techniques in optical fiber communication systems. More particularly, the invention relates to the use of non-linear optical behavior to restore degraded optical pulses. BACKGROUND OF THE INVENTION [0002] In high-speed optical fiber communication systems, digital data are transmitted in the form of optical pulses propagating in the fiber. An ideal pulse is well localized within a time window and has a well-defined amplitude that stands out distinctly from a low background level. However, noise, chromatic dispersion, and other effects tend to spread the pulses out and to obscure the distinction between pulse and background. These effects can lead to the misinterpretation of high pulse levels (e.g., “ones” in a binary system) as low levels (e.g., as “zeroes” in a binary system) and vice versa. This, in turn, tends to drive up the Bit Error Rate (BER) of the system. [0003] Practitioners have devised regenerators for optical pulses. Ideally, optical energy enters a regenerator as a degraded pulse having a high noise level, a reduced peak amplitude, and expanded width, and exits the regenerator with low background noise and with its original peak amplitude and width restored. Even if they only approximate such ideal behavior, optical regenerators can be advantageous in communication systems for counteracting the degeneration of pulses over long propagation distances. [0004] One particular approach to optical regeneration is described in U.S. Pat. No. 6,141,129, issued on Oct. 31, 2000 to P. V. Mamyshev under the title “Method And Apparatus For All-Optical Data Regeneration.” Central to the Mamyshev regenerator is a nonlinear optical fiber, that is, an optical fiber that can alter the spectral content of a pulse of sufficient amplitude through nonlinear coupling between the fiber material and the electromagnetic field associated with the pulse. As a result of such coupling, stronger portions of a given pulse become spectrally broadened; but the amount of such broadening decreases sharply for weaker portions of the pulse. The spectrally altered pulse is then passed through a filter whose transmission characteristic is offset from the original spectral content of the pulse. We refer to such a filter as an “output filter” of the regenerator. The output filter substantially blocks the weaker portions of the pulse, which were not spectrally broadened, but substantially passes the stronger portions, which contain enhanced spectral content that lies within the passband of the filter. Because only the strongest portion, typically the central portion, of the pulse is passed by the filter, an approximation to the original shape of the pulse is obtained and relatively low background noise is eliminated. If desired, the original amplitude is restored by amplification before the nonlinear fiber, or after it, or both. [0005] Typically, a Mamyshev regenerator includes a dispersion-compensator placed before the nonlinear fiber. The dispersion compensator is an element that has, in effect, a dispersion coefficient opposite in sign to that to which the pulses have been subject while propagating through the system. Such an element is selected, and in some cases can be tuned, to provide a sufficient amount of dispersion to at least approximately cancel the dispersion accumulated during propagation through the system. [0006] We have discovered that in some operating regimes, the performance of the Mamyshev regenerator is very sensitive to the residual dispersion effects that remain impressed upon the optical pulses. However, the magnitude of these effects is not always known in advance. For this reason among others, there is a need for a device to monitor the effectiveness of pulse shaping in a nonlinear optical fiber. SUMMARY OF THE INVENTION [0007] The invention is embodied in a system for monitoring the effectiveness of pulse shaping in a nonlinear optical fiber. More specifically, according to embodiments of the invention, the spectral content of the pulse, after passing through the nonlinear fiber, provides a useful indication of how effectively the pulse was regenerated. Thus, according to the invention in a broad aspect, a portion of the pulse exiting the nonlinear fiber is tapped off, and a measurement is made of the pulse energy in at least one selected spectral region. The selected spectral region is one in which the pulse tends to gain energy when effective regeneration is taking place. [0008] In specific embodiments of the invention, the selected spectral region is defined by the output filter of a Mamyshev regenerator. In such embodiments, one useful approach is to compare the pulse energy just after the output filter to the pulse energy just before the output filter. In other specific embodiments of the invention, the tapped off pulse energy is directed into an optical spectrum analyzer adapted to measure the energy in at least one spectral region such as a narrow band about a selected wavelength. [0009] In another aspect, the embodiments of the invention involve an optical communication system in which the information concerning the effectiveness of pulse shaping in a nonlinear optical fiber is fed back in order to dynamically change the residual dispersion at the regenerator input. Even more broadly, the spectral measurement described above can lead to a control signal to indicate a level of performance of the system, or to improve the performance of the system by adjusting an operational parameter. Operational parameters that may be adjusted in this manner include the tuning of a tunable dispersion compensator situated before the nonlinear fiber, the gain of one or more optical amplifiers associated with the regenerator or situated elsewhere in the system, and the tuning of the output filter of the regenerator. BRIEF DESCRIPTION OF THE DRAWINGS [0010] In the drawings: [0011] [0011]FIG. 1 a is a simplified, schematic diagram of an optical communication system according to embodiments of the invention; [0012] [0012]FIG. 2 is a graphical diagram of an input optical data stream superimposed with the data stream received at the spectral monitor of the optical communication system of FIG. 1; [0013] [0013]FIG. 3 is a graphical diagram of the operation of the output filter in the regenerator in the optical communication system of FIG. 1 by showing the input spectrum into the output filter and the output spectrum exiting the output filter; [0014] [0014]FIG. 4 is a graphical diagram of the sensitivity of the receiver in the optical communication system of FIG. 1; [0015] [0015]FIG. 5 is a simplified, schematic diagram of an optical communication system according to an alternative embodiment of the invention; [0016] [0016]FIG. 6 is a simplified, schematic diagram of a monitoring configuration according to an alternative embodiment of the invention; [0017] [0017]FIG. 7 is a simplified, schematic diagram of a monitoring configuration according to yet another alternative embodiment of the invention; [0018] [0018]FIG. 8 is a simplified, schematic diagram of a monitoring configuration according to still alternative embodiment of the invention; and [0019] [0019]FIG. 9 is a simplified, schematic diagram of a monitoring configuration according to yet alternative embodiment of the invention. DETAILED DESCRIPTION [0020] In the following description similar components are referred to by the same reference numeral to simplify the sequential aspect of the drawings and/or to enhance the understanding of the invention through the description of the drawings. Also, unless otherwise explicitly specified herein, the drawings are not drawn to scale. [0021] Although specific features, configurations and arrangements are discussed hereinbelow, it should be understood that such is done for illustrative purposes only. A person skilled in the relevant art will recognize that other steps, configurations and arrangements are useful without departing from the spirit and scope of the invention. [0022] The optical communication system of FIG. 1 includes communication optical fiber 10 , tunable dispersion compensator 15 , optical amplifier 20 , regenerator 25 , output optical fiber 30 , and receiver 32 . Regenerator 25 includes optical amplifier 35 , highly nonlinear fiber 40 , and output filter 45 . Typical characteristics of fiber 40 are: 2.010 km length, 0.81 dB/km attenuation at a wavelength of 1550 nm, dispersion at 1550 nm of −0.48 ps/nm-km, D slope of 0.020 ps/nm2-km, zero-dispersion wavelength of 1574 nm, mode-field diameter of 4.02 micrometer, cut-off wavelength of 1190 nm, and insertion loss of 2.5 dB. [0023] A regenerator of the kind shown is described in the Mamyshev patent application cited above. In at least some cases, it will be advantageous to operate amplifier 35 in such a way that the signal entering highly nonlinear fiber 40 has constant average power. This is useful, for example, because otherwise, if the power increases, the spectral broadening will increase, even if the residual dispersion is constant. The system also optionally includes compression stage 50 situated before regenerator 25 . A compression stage is useful for suppressing the effects of stimulated Brillouin scattering (SBS) in the communication fiber. The illustrative compression stage shown in the figure includes optical amplifier 55 , highly nonlinear fiber 60 , and standard single-mode (SSM) fiber 65 . Optical compression is described, for example, in G. P. Agrawal, Nonlinear Fiber Optics Chapter 6, Academic Press 1995 . [0024] As noted above, dispersion compensators may be fixed or tunable. As will be explained below, tunable dispersion compensators such as compensator 15 are advantageous, because they can be tuned to optimize the performance of the optical regenerator. Tunable dispersion compensators are known in the art, and are described, for example, in U.S. Pat. No. 6,181,852, which issued on Jan. 30, 2001 to L. E. Adams et al. under the title “Optical Grating Device with Variable Coating,” and U.S. Pat. No. 6,148,127, which issued on Nov. 14, 2000 to L. E. Adams et al. under the title “Tunable Dispersion Compensator and Optical System Comprising Same.” [0025] Very briefly, dispersion compensators of the kind described in the above-cited patents include a section of optical fiber in which there is formed a distributed Bragg reflector having a grating period that varies monotonically with distance along the fiber. The reflection of light by such a structure depends upon a resonant interaction between the incident light and the Bragg grating. Consequently, the effective distance that incident light will penetrate into the reflector before being reflected back out of it will depend upon the wavelength of the incident light. If the rate of change of the grating period (i.e., the “chirp”) is appropriately adjusted, leading spectral components of a pulse can be relatively delayed, and thus brought into coincidence with trailing portions of the pulse, by arranging for the leading portions to penetrate more deeply into the reflector than the trailing portions. The amount of relative delay can be adjusted, i.e., “tuned,” by controlling the rate of change of the grating period along the fiber axis. A control signal, which is by way of illustration an electrical signal, can be used to exercise the requisite control. For example, the chirp can be adjusted by applying a thermal gradient to the fiber in which the Bragg reflector is formed, or by mechanical deformation induced by using a solenoid to apply an axial force to magnetic elements affixed to the fiber. The control signal is readily used to control, e.g., a heater for applying the thermal gradient, or a current source for energizing the solenoid. [0026] Also shown in FIG. 1 is optical tap 70 , which diverts a portion of the pulse energy exiting highly nonlinear regenerator fiber 40 into monitor fiber 75 , and from there into spectral monitor 80 . As will be explained below, measurements made by spectral monitor 80 can provide an indication of how effectively the regenerator is operating. Typically, standard fiber will enter and leave the tap, although other types of fiber, including the nonlinear regenerator fiber, may also be used. Tap 70 may comprise, for example, a fused fiber coupler, tilted fiber grating, or a cut in the fiber coupled to bulk optics to direct some of the light into the spectral monitoring component and some back into the transmission fiber. The spectral monitoring may be achieved with any of various types of filters, including thin film interference filters, fiber Bragg grating filters, long period fiber grating filters, tilted fiber gratings, and etalons. [0027] Superposed in FIG. 2 are the wavelength spectrum 85 of an input optical data stream as received by tunable dispersion compensator 15 from communication fiber 10 , and the wavelength spectrum 90 of the data stream as received at spectral monitor 80 . Spectrum 90 was measured with compensator 15 tuned for complete dispersion compensation. It will be apparent from FIG. 2 that the input data stream, which contains pulses that are spread out in time, contain energy in a relatively narrow range of wavelengths, whereas the compensated data stream, whose pulses are more narrowly confined in time, occupies a substantially broader spectral range. It will also be apparent that spectrum 90 of the compensated data stream contains many sidebands. This sideband structure is a result of the modulation of the data stream, which in this instance was carried out to produce a data rate of 40 Gb/s. [0028] The operation of output filter 45 relative to the spectral broadening of the data stream is illustrated schematically in FIG. 3. In that figure, spectrum 95 is the spectrum of the data stream that exits the regenerator. Spectrum 100 is the passband of output filter 45 . It will be understood that spectral broadening in the regenerator tends to increase the amount of energy in spectrum 95 that also lies within passband 100 , and thus is substantially passed by filter 45 . Significantly, various central frequencies and/or widths can be specified for spectrum 100 . Filter 45 can be designed, and in some cases can be tuned, to impart specified central frequencies and/or widths. The precise design or tuning of filter 45 can affect the performance of the regenerator. Thus, filter 45 is advantageously selected or controlled so as to provide the best achievable performance. [0029] We have found that the performance of the regenerator is very sensitive to residual effects of dispersion that are embodied in the optical pulses input to the regenerator. By way of illustration, we have plotted as curve 105 of FIG. 4 a series of experimental measurements of receiver sensitivity at receiver 32 of the system of FIG. 1, as the tuning of dispersion compensator 15 was varied. The most complete cancellation of dispersion effects took place at a corrective dispersion, in the compensator, of about −390 ps/nm. The sensitivity plotted in the figure was the lowest received power level for which the bit-error rate (BER) was no more than 10 −9 . It will be evident from the figure that the most advantageous receiver sensitivity was obtained in a range of about 10 ps/nm about the optimum tuning of the dispersion compensator. When the compensator was tuned outside of and away from that range, the receiver sensitivity was found to degrade rapidly. [0030] We have discovered a useful correlation between the amount of optical power in at least some of the spectral sidebands and the performance of the regenerator as determined, for example, from measurements of receiver sensitivity. By way of illustration, we have plotted as curve 110 of FIG. 4 the total optical power in a selected sideband at each of the settings of the tunable dispersion compensator that corresponded to the data points plotted in curve 105 . The selected sideband was the sixth sideband on the long-wavelength side of the center wavelength. The center wavelength was 1552.6 nm, and the sixth sideband occurred at about 1554.5 nm. The sideband power was computed from a spectrum measured by spectral monitor 80 of the system of FIG. 1. For the experiment represented by curve 110 , the spectral monitor was a Hewlett-Packard Optical Spectrum Analyzer. [0031] It will be evident from a comparison of curve 110 with curve 105 that relatively high values of the sideband power occur for that range of settings of the tunable dispersion compensator that yields the most beneficial levels of receiver sensitivity. As a consequence, the measured sideband power is useful as an indicator of how effectively the regenerator is operating. As will be discussed in more detail below, the measured sideband power can also be used in a feedback loop to automatically adjust one or more operational parameters of the communication system. For example, the measured sideband power, or a signal derived therefrom, can be used to control tunable dispersion compensator 15 . As a further example, the same power or signal derived therefrom can be used to control the gain of an optical amplifier such as amplifier 35 . As yet a further example, the same power or derived signal can be used to control output filter 45 by, for example, shifting its center frequency or modifying its bandwidth. [0032] Experimental data according to embodiments of the invention have shown, e.g., that not all sidebands behave consistently as the tuning of compensator 15 is varied. For example, in the experiment represented in FIG. 2, we observed two wavelength regimes. Within an inner regime that, at a particular input intensity extended to about 2 nm on each side of the center wavelength of 1552.6 nm, both rising and falling sidebands were observed as the amount of dispersion compensation increased. However, in an outer regime of wavelengths more than 2 nm from the center wavelength, we found that the magnitude (i.e., the total optical power) of the sidebands increased consistently as the residual dispersion effects were reduced. With increasing intensity, the boundary between the inner and outer regimes moved further from the center frequency. This observation suggests that in at least some cases it will be advantageous, for purposes of spectral monitoring as well as for proper regenerator performance, to hold constant the power level within the regenerator. [0033] One useful monitoring scheme is to monitor the power in a single sideband, selected to dependably lie within the outer wavelength regime. Another useful monitoring scheme is to measure the power in all sidebands greater than some order, or all sidebands lying within the outer regime. This second scheme is advantageous because it will typically provide a stronger monitor signal and thus relax the demands on the monitor hardware. However, we also observed that the sum of all high-order sidebands (i.e., the sidebands that had monotonic behavior with respect to residual dispersion) did not behave as consistently with respect to dispersion compensation as did certain single selected sidebands. [0034] An alternative monitoring scheme is depicted in FIG. 5. Elements of the system shown in FIG. 5 that correspond to similar elements of the system shown in FIG. 1 are referred to by like reference numerals. The monitoring scheme of FIG. 5 uses a filter to perform spectral selection for purposes of monitoring. As illustrated, regenerator output filter 45 is also used for this monitoring function. In at least some cases, however, it may be preferable to use a separate filter, having distinct characteristics, to perform the monitoring function. In the system shown in the figure, coupling elements 115 and 120 are placed, respectively, just before and just after filter 45 . Each of these elements is exemplarily a fused fiber coupler or other broadband tap, such as a fiber grating tap or a bulk optic tap. Each of elements 115 and 120 taps a portion of the light output from highly nonlinear fiber 40 into an optical detector that measures the optical power of the light that it receives. The ratio that the power received from element 120 stands in, relative to the power received from element 115 , provides a useful measure of spectral broadening undergone in the regenerator. Thus, such a power ratio can provide a useful control signal or feedback signal. [0035] Monitoring schemes using a filter 125 additional to the regenerator filter are shown in FIGS. 6-9. [0036] It will be apparent to those skilled in the art that many changes and substitutions can be made to the embodiments of the invention herein described without departing from the spirit and scope of the invention as defined by the appended claims and their full scope of equivalents.

Embodiments of the invention include system for monitoring the effectiveness of pulse shaping in a nonlinear optical fiber ( 40 ). The spectral content of the pulse, after passing through the nonlinear fiber ( 40 ), provides an indication of how effectively the pulse was regenerated. A portion of the pulse exiting the nonlinear fiber is tapped off and its pulse energy is measured in at least one selected spectral region. The selected spectral region is one in which the pulse tends to gain energy when effective regeneration is taking place. The information concerning the effectiveness of pulse shaping in a nonlinear optical fiber is fed back to dynamically change the residual dispersion at the regenerator input. The spectral measurement leads to a control signal ( 48 ) to indicate a level of performance of the system, or to improve the performance of the system by adjusting an operational parameter.

FIELD OF THE INVENTION The field of the invention is isoflavones. BACKGROUND OF THE INVENTION The isoflavones are a group of naturally occurring plant compounds having the aromatic heterocyclic skeleton of flavan. Soybeans are the most common and well known source of isoflavones, reported to contain the isoflavones, daidzin, genistin, glycitin, 6″-dadidzin-O-acetyl, 6″-O-acetyl genistin, 6″-O-malonyl daidzin, and 6″-O-malonyl genistin. (see U.S. Pat. No. 5,679,806 to Zheng et al., (October 1997) incorporated herein by reference). Isoflavones are present in processed soy foods as well, including miso and soy sauce. Legumes, lupine, fava bean, kudzu and psoralea may also be important sources. The existence of isoflavones in Pueraria has long been known, with the roots of Pueraria containing several isoflavone compounds, such as daidzin, and puerarin. Isoflavones are known in aglucone forms, as well as 7-acetylated and 7-substituted glycosides. Especially important isoflavones in aglucone form include daidzein, genistein, and glycitein. Especially important isoflavones in 7-glycoside form include daidzin, genistin, and glycitin. Genistein is also known to occur naturally as a 4′-glucoside (sophoricoside), and a 4′-methyl ether (biochanin A). Isoflavones in general, and genistein in particular, have structural similarities to that of certain human estrogens, and such compounds are said to have estrogenic activity. Isoflavones are also said to have other useful biological and pharmacological activities, including antiangiogenic, antihemolytic, antiischemic, antileukemic, antimitogenic, antimutagenic, antioxidant, fungicidal, pesticidal, MAO-inhibition, phytoalexin, and tyrosine kinase inhibition activities (1). The anticancer effects of genistein are of particular interest. Genistein may exert antitumor effects in part by inhibiting angiogenesis, i.e., reducing formation of vasulature and blood flow to the tumor. Its affinity to estrogenic sites in the vicinity of cancer cells may also inhibit tumor growth. As a well-known inhibitor of the enzyme tyrosine kinase, genistein may also inhibit energy and signaling pathways in tumors. Examples of research are described in references 4 and 5 . Genistein and other isoflavones are also said to be important contributors to bone health, resulting at least in part from the ability of these compounds to inhibit protein kinase activity, and thereby inhibit osteoclast cell activity. The isoflavones are especially attractive in this regard because they generally have a low toxicity relative to many other known protein kinase inhibitors. Examples of research along these lines are described in references 6 and 7 . Citations for still other research articles describing beneficial effects of isoflavonoids are set forth as references. Because of its many beneficial effects, enriched sources of genistein are marketed to consumers around the world in a wide variety of nutritional supplements. Many of the health benefits of soy products are ascribed to the presence of genistein. Unfortunately genistein and other isoflavones are very insoluble in water. See, for example, descriptions of genistein, genistin, biochanin A, and sophoricoside in the Merck Index (3). The insolubility of the isoflavones complicates their formulation into foodstuffs and cosmetics, many of which are aqueous-based systems. Low solubility is also frequently an impediment to efficient bioavailability in orally administered products. Low solubility is a particularly serious impediment to formulation of intravenous medications, which are most often delivered in aqueous media. Thus, there is a continuing need to provide isoflavones in forms which have increased bioavailability, especially enhanced aqueous solubility relative to the unmodified compounds, while retaining the active properties of such unmodified compounds. SUMMARY OF THE INVENTION Methods and compositions of the present invention provide increased bioavailability of isoflavones by converting a starting isoflavone into a pro-compound. This is preferably accomplished by attaching a polar (solubilizing) leaving group which can be readily hydrolyzed under physiologic conditions to produce the starting isoflavone. In preferred embodiments, an alcohol functionality of an isoflavone is esterified using a carboxylic acid group or a phosphoric acid group. This yields a carboxylic acid hemiester or a phosphate ester. In general, fluids of the digestive and absorptive gastrointestinal tract, other acids, and various enzymes are capable of hydrolyzing the esterified isoflavone to the starting isoflavone. In another aspect of the invention, the starting isoflavone preferably comprises a natural isoflavone, more preferably comprises genistin or daidzin, and still more preferably comprises an aglycone form such as genistein or daidzein. In still other aspects of the invention, the pro-compounds may advantageously be employed therapeutically or prophylactically for a variety of conditions, provided as a dietary supplement, or added to natural or processed food-stuffs. Thus, the pro-compounds may be used as pro-drugs or pro-nutrients. Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural representation of a generalized isoflavone. DETAILED DESCRIPTION FIG. 1 depicts a generalized isoflavone. Using this structure as a reference, known isoflavones include the following (where the 6“position is on the glucose ring): Isoflavone R 8 R 7 R 6 R 5 R 4 ′ daidzin H O-glucose H H OH genistin H O-glucose H OH OH glycitein H OH OMe H H puerarin glu- OH H H H cose 6″-O-acetyl daidzin H O-acetyl glucose H H OH 6″-O-acetyl genistin H O-acetyl glucose H OH OH 6″-O-malonyl daidzin H O-malonyl glucose H H OH 6″-O-malonyl genistin H O-malonyl glucose H OH OH genistein H OH H OH OH daidzein H OH H H OH glycitin H O-glucose OMe H H It is now contemplated that a natural or modified isoflavone may be esterified to provide a pro-compound having increased bioavailability, and in particular enhanced aqueous solubility relative to the unesterified isoflavone. In preferred embodiments one or more of R 7 , R 6 , R 5 and R 4 ′ comprise ZOOO— or ZPO 4 —, where Z is selected from the group consisting of a straight or branched aliphatic chain, including an alkyl, alkenyl, alkynyl, alkoxyalkyl, alkylthioalkyl, aminoalkyl group, including substituted derivatives of such groups, a substitute or non-substituted cycloalkyl, and an aromatic group, including aryl, aralkyl, or alkylaryl, and substituted derivatives such as where a ring contains one or more nitrogen, sulfur, oxygen, phosphorous or silicon heteroatoms. Such compounds are considered herein to be esterified isoflavones in which an isoflavones is modified by esterification in at least one of the C4′, C5, C6, and C7 positions. To clarify further, it is contemplated that Z may comprise hydrogen; hydroxyl; cyano; nitro; halo; alkyl such as methyl, ethyl, butyl, pentyl, octyl, nonyl, tert-butyl, neopentyl, isopropyl, sec-butyl, dodecyl and the like, alkenyl such as 1-propenyl, 4-butenyl, 1-pentenyl, 6-hexenyl, 1-heptenyl, 8-octenyl and the like; alkoxy such as propoxy, butoxy, methoxy, isopropoxy, pentoxy, nonyloxy, ethoxy, octyloxy, and the like; alkanoyl such as butanoyl, pentanoyl, octanoyl, ethanoyl, propanoyl and the like; arylamino and diarylamino such as phenylamino, diphenylamino and the like; alkylsulfinyl, alkylsulfonyl, alkylthio, arylsulfonyl, arylthio, and the like, such as butylthio, neopentylthio, methylsulfinyl, benzylsulfinyl, phenylsulfinyl, propylthio, octylthio, nonylsulfonyl, octylsulfonyl, methylthio, isopropylthio, phenylsulfonyl, methylsulfonyl, nonylthio, phenylthio, ethylthio, bezylthio, phenethylthio, sec-butylthio, naphthylthio and the like; alkoxycarbonyl such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl and the like; alkyl amino and dialkylarnino such as dimethylamino, methylamino, diethylamino, ethylamino, dibutylamino, butylamino and the like; cycloalkyl such as cyclohexyl, cyclopentyl, cyclooctyl, cycloheptanyl and the like; alkoxyalkyl such as methoxymethylene, ethoxymethylene, butoxymethylene, propoxyethylene, pentoxybutylene and the like; arylalkylarnino such as methylphenylamino, ethylphenylamino and the like; aryloxyalkyl and aryloxyaryl such as phenoxyphenylene, phenoxymethylene and the like; and various substituted alkyl and aryl groups such as 1-hydroxybutyl, 1-aminobutyl, 1-hydroxylpropyl, 1-hydroxypentyl 1-hydroxyoctyl, 1-hydroxyethyl, 2-nitroethyl, trifluoromethyl, 3,4-epoxy-butyl, cyanomethyl, 3-chloropropyl, 4-nitrophenyl, 3-cyanophenyl, 1-hydroxymethyl, and the like; hydroxyl terminated alkyl and aryl groups such as, 2-hydroxy ethyl, 4-hydroxy butyl and 4-hydroxy phenyl; sulfonic, sulfuric, carboxylic, phosphoric and phosphoric acid terminated alkyl and aryl groups such as ethylsulfonic acid, propylsulfonic acid, butylsulfonic acid, phenylsulfonic acid, and the corresponding carboxylic and phosphoric acids and derivatives of said sulfonic, carboxylic and phosphoric acids as for example salts, esters and the like. Of course, those skilled in the art will appreciate that higher solubility in aqueous environments is generally preferred over lower solubility. Thus, where R 7 , R 6 , R 5 or R 4 ′ comprise ZOOO—, Z is advantageously selected to have a polar group, and any alkyl segment is advantageously selected to be small. Among the dicarboxylic acid groups, hemisuccinate is by far the most common, useful and biocompatible group, and is specifically contemplated for this purpose. Glutarate and adipate are also preferred. Where R 7 , R 6 , R 5 and R 4 ′ comprise ZPO 4 —, a (OH) 2 PO 2 ester is preferred because it has two polar groups, is a good solubilizer, and has high biological compatibility. Any additions to the PO 4 (such as (RO) 2 PO 2 —) are contemplated to generally reduce aqueous solubility, and are therefore disfavored. With respect to complexes, it is contemplated to employ metal salts of the esterified isoflavones, especially Li+, Na+, K+, Mg++ and ammonium salts, including NH4+ and low molecular weight mono- or polyalkylammonium. EXAMPLES By way of example, and not of limitation, several embodiments of the inventive subject matter have been prepared and characterized. These examples all fall within the group of pro-compounds where at least one of R 7 , R 6 , R 5 and R 4 ′ is H 2 PO 4 —, and HOOC—(CH 2 )x—COO— where x=2, 3, or 4. These new phosphate esters and hemiesters are all water soluble and readily hydrolyzed. They are also stable. In aqueous solutions of the exemplified compounds, for example, hydrolysis occurs to the extent of less than 1% per day, when stored at pH 7.4 and 37° C. Dry formulations of the same compounds appear to be indefinitely stable. Example 1 Mixed Phosphate Esters of Genistein A solution of genistein (135 mg, 0.5 mmole) and di-tert-butyl phosphoramidite (330 ul, 1.0 mmole) in DMF (1 ml) was stirred under argon while 1H-tetrazole (210 mg in 0.5 ml of DMF; 3.0 mmole) was added dropwise. After a few minutes, the solution was cooled to −20° C., then a solution of m-chloroperbenzoic acid (260 mg in 0.5 ml of methylene chloride, 1.5 mmole) was added dropwise. After warming to room temperature, the mixture was diluted threefold with ethyl acetate, then washed with 10% sodium metabisulfie and 10% sodium bicarbonate. A wash with 5% sodium carbonate removed a trace of unreacted genistein. The ethyl acetate solution, containing the butyl esters of the genistein phosphates, was washed with 1M HCl and dried over sodium sulfate. After removal of the solvent in vacuo, the residue was treated with 30% TFA in acetic acid for 90 minutes at room temperature. The solvents were removed in vacuo, and the residue was taken up in ethanol and neutralized with sodium hydroxide to pH 5.5. Removal of the solvent in vacuo left a mixture of sodium salts of genistein phosphates, 145 mg. HPLC analyses were performed using a Chrompack Intersil C8 column, 4.6×250 mm. The solvent was a mixture of 25% acetonitrile and 75% 0.1M diammonium phosphate, pH 2.5, at a flow rate of 1 ml/min. Detection was by UV at a wavelength of 260 nm. HPLC analysis of the phosphate mixture showed approximately equal amounts of the 4′-phosphate, the 7-phosphate and the 4′, 7- diphosphate, and only a small amount of the 5-phosphate. Example 2 Genistein-7-phosphate a) Genistein-7-tosylate: p-Toluenesulfonyl chloride (540 mg, 2.8 mmoles) was added during 4 hours to a stirred mixture of genistein (730 mg, 2.7 mmoles) and potassium carbonate (2 g) in 25 ml of acetone. After stirring overnight, the mixture was poured into brine and extracted with ethyl acetate. The extract was evaporated under vacuum, and the residue chromatogrammed through silica gel with dichloromethane and chloroform. Crystallization from methanol yielded 920 mg (80.2% yield) of genistein-7-tosylate. The proton magnetic resonance spectrum was consistent with the expected structure. 4′,5-Di(methoxymethyl)-genistein-7-tosylate: Chloromethyl methyl ether (90 ul, 1.12 mmoles) was added to a solution of genistein-7-tosylate (106 mg, 0.25 mmoles) and diisopropylethylamine (200 ul, 1.15 mmoles) in 0.6 ml of dioxane, under argon atmosphere, and stirred overnight. The mixture was poured into brine, extracted with ethyl acetate, and chromatogrammed through silica gel with dichloromethane. Crystallization from methanol yielded 115 mg (90% yield) of 4′,5-Di(methoxymethyl)-genistein-7-tosylate. The proton magnetic resonance spectrum was consistent with the expected structure. c) 4′,5-Di(methoxymethyl)-genistein: Potassium carbonate (700 mg) in water (5 ml) was added to a solution of 4′,5-di(methoxymethyl)-genistein-7-tosylate (600 mg, 1.17 mmoles) in 15 ml methanol under argon, and stirred overnight. The mixture was poured into brine, extracted with ethyl acetate, and recrystallized from methanol. The yield of 4′,5-Di(methoxymethyl)-genistein was 344 mg (82%). The electrospray mass spectrum in negative mode showed ion m/z 357[M−1] which confirmed the expected molecular weight of 358. The proton and carbon magnetic resonance spectra were consistent with the expected structure. d) Genistein-7-phosphate: 1H-Tetrazole (120 mg, 1.7 mmoles) was added to a solution of di-tert-butyl-diethylphosphoramidite (180 ul, 0.64 mmoles) and 4′,5-di(methoxymethyl)-genistein (200 mg, 0.56 mmoles) in 1.5 ml of N,N-dimethylacetamide under argon. After 10 minutes at room temperature, the mixture was cooled to −40° C., and a solution of m-chloroperbenzoic acid (130 mg, 0.75 mmoles) in dichloromethane was added rapidly. After warming to room temperature, the mixture was diluted with ether and washed with brine containing sodium bicarbonate. The solvent was removed, and the residue treated with 40% trifluoroacetic acid in acetic acid for 30 minutes. The volatile acids were removed under vacuum, and the residue dissolved in 2-propanol (4 ml) containing 0.2 ml 6N HCl and left overnight. The mixture was poured into brine and extracted with ethyl acetate. The solvent was removed, and the residue was dissolved in ethanol (3 ml) and adjusted to pH 5.5 with NaOH. After evaporation, the residue was crystallized from ethanol, yielding 155 mg (75% yield) of genistein-7-phosphate as the sodium salt. The electrospray mass spectrum in negative mode showed ion m/z 349[M−1] which confirmed the expected molecular weight of 350. The nuclear magnetic resonance spectra were consistent with the expected structure. Example 3 Mixed Hemisuccinate Esters of Genistein A solution of genistein (135 mg, 0.5 mmole) in 2.0 ml of pyridine was stirred at room temperature while succinic anhydride (100 mg, 1.0 mmole) was added in several portions. After stirring overnight at room temperature, the solvent was removed in vacuo. The gummy residue was taken up in water, adjusted to pH 3.0, and extracted three times with ethyl acetate. The ethyl acetate extracts were washed with water, then evaporated to dryness in vacuo. The crude mixture of mixed hemisuccinic acid esters weighed 205 mg. Thin layer chromatography of the product showed principally the presence of mixed mono- and disuccinate esters of genistein. The product was completely soluble in phosphate buffer at pH 7. Example 4 Genistein-7-hemisuccinate To a solution of 4′,5-Di(methoxymethyl)-genistein (see example 2c) (100 mg, 0.28 mmole) in 1.5 ml of pyridine was added succinic anhydride (50 mg, 0.5 mmole) with stirring at room temperature. After stirring overnight, the solvent was removed in vacuo. The residue was taken up in water containing one drop of glacial acetic acid, and again evaporated to dryness in vacuo. The residue was chromatogrammed through silica gel with dichloromethane and ethyl acetate. The yield of the 7-hemisuccinic ester of 4′,5-di(methoxymethyl)-genistein was 102 mg (78%). The product was dissolved in 2-propanol (3 ml) containing 0.2 ml 6N HCl and left overnight. The solution was evaporated to dryness. The residue taken up in 1 ml of ethyl acetate and crystallized by the addition of hexane. The yield of genistein-7-hemisuccinate was 52 mg (50%). Example 5 Non-enzymatic Hydrolysis of Genistein Esters HPLC analysis was conducted using a Partisil ODS-3 column (9.5×250 mm), with methanol as the mobile phase, and UV detection at 260 nm. A solution of genistein-7-phosphate (2.5 mg) in 5 ml of phosphate-buffered saline (0.1 M) at pH 7.4 was incubated at 37° for 10 days. Analysis by HPLC showed that absence of free genistein. A solution of genistein-7-hemisuccinate (2.5 mg) in 5 ml of phosphate-buffered saline (0.1 M) at pH 7.4 was incubated at 37° for 10 days. Analysis by HPLC showed a conversion of about 4% of the hemisuccinate ester to free genistein. Example 6 Hydrolysis of Genistein-7-phosphate by Various Enzymes and Biological Media In each of these experiments, free genistein was extracted with a 1:1 mixture of ethyl acetate and hexane, then analyzed by HPLC under the conditions described in example 5. a) In human serum (Sierra Biologicals) at 37° C., the half-life for hydrolysis to free genistein was about 5 hours. b) In human blood (Sierra Biologicals) at 37° C., the half-life for hydrolysis to free genistein was about 6 hours. c) In rat blood (Sierra Biologicals) at 37° C., the half-life for hydrolysis to free genistein was about 30 minutes. d) In human serum (Sierra Biologicals) at 37° C., the half-life for hydrolysis to free genistein was about 5 hours. e) In alkaline phosphatese type VII-S at 37° C., the initial rate of hydrolysis to free genistein was 0.08% per minute. This enzyme is from bovine intestinal mucosa (Sigma cat no. P5521). 0.5 DEA units were dissolved in 1.0 ml of 0.1M glycine buffer pH 10.4, and the initial substrate concentration was 1.07 mM. f) In alkaline phosphatese type XXIV at 37° C., the initial rate of hydrolysis to free genistein was 0.05% per minute. This enzyme is from human placenta (Sigma cat no. P3895). 0.1 glycine units were dissolved in 1.0 ml of 0.1M glycine buffer pH 10.4, and the initial substrate concentration was 1.07 mM. Uses It is contemplated that esterified isoflavones will be readily converted to free isoflavone in biological media such as gastrointestinal fluid and blood. Among other things, gastrointestinal fluids often have enzymes and sufficiently high pH to hydrolyze ester bonds, and blood generally contains enzymes such as phosphatases and esterases which can hydrolyze phosphate ester and carboxylate ester bonds. Contemplated uses of esterified isoflavones include any presently known or later discovered uses for isoflavones or isoflavonoids. Among other things, it is contemplated that esterified isoflavones can be administered to (which term is used herein to include “taken by”) a person for any of the beneficial effects for which a natural isoflavonoid is thought to be advantageous. This specifically includes any of the effects listed above or described in any of the literature cited herein, and includes uses where the desired effect is antiangiogenic, antihemolytic, antiischemic, antileukemic, antimitogenic, antimutagenic, antioxidant, fungicidal, pesticidai, MAO-inhibition, phytoalexin, and tyrosine kinase inhibition. It is especially contemplated that esterified isoflavones can be used to treat osteoporosis and other symptoms of estrogen deficiency in postmenopausal women. Also, it is contemplated that the compounds of the present invention can be used to prevent osteoporosis and consequent fractures that result from osteoporosis, which are major contributors to morbidity and mortality in the elderly. Still further, it is contemplated that esterified isoflavones can be used prophylactically to provide UV protection and in other ways to improve general skin health, to stimulate the immune system, and to reduce undesirable effects of oxidation (i.e., provide antioxidant benefits). Those skilled in the art will recognize that esterified isoflavones may be employed in many different ways. When taken orally, esterified isoflavones may be incorporated into food or beverage material, for nutritional, therapeutic, prophylactic value, or any combination of these. Esterified isoflavones may also be administered by any appropriate form of in vivo delivery, which is defined herein to include oral, intravenous, subcutaneous, intraperitoneal, intrathecal, intramuscular, intracranial, inhalational, topical, transdermal, suppository (rectal), pessary (vaginal), administration and the like. Thus, delivery may occur through foods, pills, capsules or liquids as a nutritional supplement, or as a pharmaceutical By way of example, it is contemplated that compounds according to the present invention can be administered alone, or formulated in admixture with a pharmaceutically acceptable carrier. For example, the compounds of the present invention can be administered orally as pharmacologically acceptable salts. Because preferred compounds of the present invention are relatively water soluble, they can be administered intravenously in physiological saline solution (e.g., buffered to a pH of about 7.2 to 7.5). Conventional buffers such as phosphates, bicarbonates or citrates can be used for this purpose. Of course, one of ordinary skill in the art may modify the formulations within the teachings of the specification to provide numerous formulations for a particular route of administration without rendering the compositions of the present invention unstable or compromising their therapeutic activity. It is also well within the ordinary skill of the art to modify the route of administration and dosage regimen of a particular compound in order to manage the pharmacokinetics of the present compounds for maximum beneficial effect in patients. One of ordinary skill in the art will also take advantage of favorable pharmacokinetic parameters of the pro-drug forms, where applicable, in delivering the present compounds to a targeted site within the host organism or patient to maximize the intended effect of the compound. In addition, compounds according to the present invention may be administered alone or in combination with other agents for the treatment of the above mentioned diseases or conditions. Combination therapies according to the present invention may comprise the administration of at least one compound of the present invention or a functional derivative thereof, and at least one other pharmaceutically active ingredient. The active ingredient(s) and pharmaceutically active agents may be administered separately or together and when administered separately this may occur simultaneously or separately in any order. The amounts of the active ingredient(s) and pharmaceutically active agent(s) and the relative timings of administration will be selected in order to achieve the desired combined therapeutic effect. To prepare the pharmaceutical compositions according to the present invention, a therapeutically effective amount of one or more of the compounds according to the present invention is preferably intimately admixed with a pharmaceutically acceptable carrier according to conventional pharmaceutical compounding techniques to produce a dose. A carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral. In preparing pharmaceutical compositions in oral dosage form, any of the usual pharmaceutical media may be used. Thus, for liquid oral preparations such as suspensions, elixirs and solutions, suitable carriers and additives including water, glycols, oils, alcohols, flavouring agents, preservatives, colouring agents and the like may be used. For solid oral preparations such as powders, tablets, capsules, and for solid preparations such as suppositories, suitable carriers and additives including starches, sugar carrier, such as dextrose, mannitol, lactose and related carriers, diluents, granulating agents, lubricants, binders, disintegrating agents and the like may be used. If desired, the tablets or capsules may be enteric-coated or sustained release by standard techniques. Thus, specific embodiments and applications of esterified isoflavones have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. References: (Incorporated Herein by Reference) 1. Phytochemical Database of the USDA Agricultural Research Service, Stephen M. Beckstrom-Sternberg & James A. Duke, Internet address: www.ars-grin.gov/˜ngrlsb/ 2. A comparative survey of leguminous plants as sources of the isoflavones, genistein and daidzein: implications for human nutrition and health. Kaufman P B; Duke J A; Brielmann H; Boik J; Hoyt J E, J Altern Complement Med, 1997, vol. 3 (1) p7-12. 3. The Merck Index, 12th Edition (1996), Merck & Co., Inc, Whitehouse Station, N.J., genistein, genistin, biochanin A: entry no. 4395 sophoricoside: entry no. 8867 4. Genistein inhibits growth of B16 melanoma cells in vivo and in vitro and promotes differentiation in vitro. Record I R; Broadbent J L; King R A; Dreosti I E; Head R J; Tonkin A L. Int. J. Cancer, 1997, vol 72 (5) p860-4 5. Genistein inhibits proliferation and in vitro invasive potential of human prostatic cancer cell lines. Santibanez J F; Navarro A; Martinez J. Anticancer Res, 1997, vol 17 (2A) p1199-204 6. Action of genistein and other tyrosine kinase inhibitors in preventing osteoporosis. Presented by H. C. Blair at: Second International Symposium on the Role of Soy in Preventing and Treating Chronic Disease, Sep. 15-18, 1996, Brussels, Belgium. 7. Inhibitory effect of genistein on bone resorption in tissue culture. Yamaguchi M; Gao Y H. Biochem Pharmacol, 1998, vol 55 (1) p71-6. 8. Effect of soybean phytoestrogen intake on low density lipoprotein oxidation resistance. Tikkanen M J et al., Proc Natl Acad Sci (USA), March 1998, vol 95 (6), p3106-10. 9. Genistein, the dietary-derived angiogenesis inhibitor, prevents LDL oxidation & protects endothelial cells from damage by atherogenic LDL. Kapiotis S, et al. Arterioscler Thromb Vasc Biol (US), November 1997, vol 17(11), p2868-74. 10. Effect of structurally related flavones/isoflavones on hydrogen peroxide production and oxidative DNA damage in phorbol ester-stimulated HL-60 cells. Giles D, Wei H. Nutr Cancer (US), 1997, vol 29(1), p77-82. 11. Antioxidant activity of phytoestrogeneic isoflavones. Ruiz-Larrea M B, et al. Free Radic Res. (Switzerland), January 1997, vol 26(1), p63-70. 12. Antioxidant and antipromotional effects of the soybean isoflavone genistein. Wei H., et al. Proc Soc Exp Biol Med (US), January 1995, vol 208(1), p124-30. 13. Mechanism of antioxidant action of pueraria glycoside (PG)-1 (an isoflavonoid) and mangiferin (a xanthonoid). Sato T, et al., Chem Pharm Bull (Japan), March 1992, vol 40 (3) p721-4. 14. Inhibition of UV light- and Fenton reaction-induced oxidative DNA damage by the soybean isoflavone genistein. Wei H, et al. Carcinogenesis (England), January 1996, vol 17(1) p73-7. 15. Evolution of the health benefits of soy isoflavones. Barnes S. Proc Soc Exp Biol Med (US) March 1998, vol 217 (3), p386-92. 16. Natural and synthetic isoflavones in the prevention and treatment of chronic diseases. Brandi M L, Calcif Tissue Int (US) 1997, 61 Suppl 1, pS5-8. 17. Effect of isoflavones genistein and daidzein in the inhibition of lung metastasis in mice induced by B16F-10 melanoma cells. Menon L G, et al. Nutr Cancer (US), 1998, vol 30 (1) p74-7. 18. Enhancement of immune function in mice fed high doses of soy daidzein. Zhang R., et al.; Nutr Cancer (US), 1997, vol. 29(1) p24-8. 19. Inhibition of N-methyl-N-nitrosourea-induced mammary tumors in rats by the soybean isoflavones. Constantinou A., Anticancer Res (GREECE) November-December 1996, vol. 16(6A), p3293-8. 20. Kudzu root: an ancient Chinese source of modern antidipsotropic agents. Keung W. M., et al.; Phytochemistry (US), February 1998, vol. 47(4), p499-506. 21. Isoflavonoid compounds extracted from Pueraria lobata suppress alcohol preference in a pharmacogenetic rat model of alcoholism. Lin R. C., et al.; Alcohol Clin Exp Res (US), June 1996, vol. 20(4), p659-63.

Isoflavones are modified by esterification at one or more of the C 4 ′, C 5 , C 6 , and C 7 positions to promote bioavailability, and especially to enhance solubility over the corresponding unesterified isoflavones. Preferred modifications produce a carboxylic acid hemiester or a phosphate ester which is biologically hyrolyzable. Preferred starting isoflavones are genistin and daidzin, and still more preferably comprises an aglycone form such as genistein or daidzein. Esterified isoflavones may be employed therapeutically or prophylactically for a variety of conditions, provided as a dietary supplement, or added to natural or processed food-stuffs.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our earlier filed and copending application Serial No. 811,083, filed June 29, 1977, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to diffusion transfer photographic products and processes employing dye developers. More precisely this invention relates to the use of certain pyridine N-oxides to provide improved processing performance characteristics for such products and processes. 2. Description of the Prior Art Diffusion transfer photographic processes and products employing dye developers are known to the art and details relating to them can be found in U.S. Pat. Nos. 2,983,606; 3,345,163; 3,415,644; 3,415,645; 3,415,646; 3,473,925; 3,482,972; 3,551,406; 3,573,042; 3,573,043; 3,573,044; 3,576,625; 3,576,626; 3,578,540; 3,579,333; 3,594,164; 3,594,165; 3,597,200; 3,647,437; 3,672,486; 3,672,890; 3,705,184; 3,752,836 and 3,857,855. Essentially, diffusion transfer photographic products and processes involve film units having a photosensitive system of element including at least one photosensitive layer usually selectively sensitized and integrated with dye developer as a dye image providing material. After photoexposure, the photosensitive layer is developed to establish an imagewise distribution of dye image providing material all or a portion of which is transferred to an image receiving element having an image receiving layer capable of mordanting or otherwise fixing the diffusible dye. The image receiving layer retains the dye image for viewing and in some diffusion transfer products, the dye image is viewed in the layer after separation from the photosensitive system while in other products, such separation is not required. Multicolor diffusion transfer images may be obtained using dye developers by several known techniques. A particularly useful technique employs an integral multilayer photosensitive element, such as is disclosed in the referenced U.S. Patents, wherein at least two selectively sensitized photosensitive layers, superposed on a common support, are photoexposed and then processed, simultaneously without separation, with a single (common) image-receiving layer. A typical arrangement of this type for obtaining multicolor images utilizing subtractive color principles comprises a support carrying a red-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer and a blue-sensitive silver halide emulsion layer, each emulsion layer being associated, respectively, with a cyan dye developer; a magenta dye developer and a yellow dye developer. The dye developer may be positioned in the silver halide emulsion layer, for example, in the form of particles, or it may be disposed in a layer behind the appropriate silver halide emulsion layer with respect to the exposing light. Each set of silver halide emulsion and associated dye developer layers may be separated from other sets by suitable interlayers, for example, by a layer of gelatin, polyvinyl alcohol, or other polymeric materials known in the art. After photoexposure, the photosensitive element is processed by application of a processing composition in manners well known in the art. The exposed photosensitive element may be superposed prior to, during, or after application of the processing composition on a sheet-like element which may include an image receiving layer. Generally, means containing the processing composition and for discharging it within the film unit are employed for applying the processing composition to the photosensitive element in a substantially uniform layer as the photosensitive element is withdrawn from the dark chamber. The applied liquid processing composition permeates the layers of the photosensitive element to initiate and effect development of the latent images contained there. The dye developers are immobilized or precipitated imagewise in developed areas as a consequence of and in proportion to the silver halide development. At least part of this immobilization is due to a change in the solubility characteristics of the dye developers upon oxidation and especially to a change in the solubility of the oxidized dye developer in alkaline solution. Accordingly, in undeveloped and partially developed areas of the silver halide emulsion layers, the respective unoxidized (unreacted) dye developers are diffusible. Development thus provides an imagewise distribution of unoxidized dye developer, diffusible in the alkaline processing composition, as a function of the point-to-point degree of exposure of a silver halide emulsion layer. At least part of each of these imagewise distributions of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer, with the transfer substantially excluding oxidized dye developer. The image receiving layer receives a depthwise diffusion, from each developed silver halide emulsion, of unoxidized dye developer without appreciably disturbing the imagewise distribution thereof to provide a reversed or positive color image of each developed silver image. The image receiving layer may contain a mordant and/or other agent to immobilize the dye developer transferred thereto. If the color of a transferred dye developer is affected by changes in the pH of the image receiving layer, this pH may be adjusted in accordance with well known techniques to provide a pH affording the desired color. As mentioned, the present invention is concerned with dye developer diffusion transfer processes and products in which an N-oxide is present during development. U.S. Pat. No. 3,998,640, issued Dec. 21, 1976 to S. J. Cuirca, Jr. also relates to diffusion transfer film units employing heterocyclic N-oxides as oxidants. According to the patent, the oxidants are particularly useful when employed in film units having oxichromic compounds as dye image providing materials. Oxidation of the dye image providing materials is achieved by using heterocyclic N-oxides having a polarographic reduction potential at least more positive than the polarographic oxidation potential of the dye image providing materials to be oxidized. Particularly useful N-oxides are those having a polarographic reduction potential more positive than -0.5 v. when in an aqueous solution comprising 4% potassium hydroxide. Representative useful N-oxides disclosed in U.S. Pat. No. 3,998,640 are benzofuroxans and 4,4-axopyridine-1,1'-dioxides of the following formulae: ##STR1## where: R 1 and R 2 each represent a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, an alkoxy group having from 1 to 25 carbon atoms, a halogen atom, a nitro group, an oxo-linked benzofuran or an organic ballasting group of such size and configuration (for example, simple organic groups or polymeric groups) as to render the compound non-diffusible, especially during treatment with an alkaline processing composition; n is an integer having a value of 0 to 1; and R 3 and R 4 each represent a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, an alkoxy group having 1 to 25 carbon atoms or an organic ballasting group as described above for R 1 and R 2 . Suitable ballasting groups typically contain an alkyl group (branched or unbranched), an aryl group, an aralkyl or an alkaryl group and typically contain 8 to 25 carbon atoms. According to the present invention, novel diffusion transfer film units employing N-oxides are presented to the art. Unlike the N-oxides of U.S. Pat. No. 3,998,640, the N-oxides employed in the present invention have polarographic reduction potentials less positive then the polarographic oxidation potential of the dye developers of the film units. As will be described in more detail in the description which follows, the use of these N-oxides provides such advantages as better control over dye transfer and particularly better control over magenta dye transfer. SUMMARY OF THE INVENTION The present invention provides novel diffusion transfer film units having a photosensitive system including at least one photosensitive layer associated with a dye developer and having within the film units as N-oxide as described hereinafter. Broadly, N-oxides suitable in the practice of the present invention are those which are substantially soluble in aqueous alkaline processing compositions and have a polarographic reduction potential less positive than the polarographic oxidation potential of the dye developer(s) of the film unit. Preferably, the N-oxides are integrated with the photosensitive systems of film units by coating them in suitable matrix material(s) as a layer of the film unit which can be permeated by a processing composition--applied after photoexposure of the unit--to carry at least some of the N-oxide to the photoexposed photosensitive system. Alternatively, the N-oxides can be included in diffusion transfer film units of the invention by incorporation of the N-oxides in a processing composition customarily distributed within the film units after photoexposure. Details and advantages of the invention will be better appreciated by reference to the accompanying figures taken with the following description of the preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-3 are simplified or schematic views of arrangements of essential elements of preferred film units of the present invention, shown after exposure and processing. FIG. 4 presents graphical representations of dye density measurements of film units discussed in Example 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred film units of the present invention are integral negative-positive film units are there are two types of such film units. Details relating to the first type are found in such patents as U.S. Pat. Nos. 3,415,644 and 3,647,437 while details of the second type are found, e.g., in U.S. Pat. No. 3,594,165. Referring now to FIG. 1 which shows a film unit of the type of referenced U.S. Pat. Nos. 3,415,644 and 3,647,437 following exposure and processing. The film unit 10 includes a light-reflecting layer 16 provided by a light-reflecting pigment in a processing composition initially present in a rupturable container (not shown) and distributed after photoexposure of photosensitive layer(s) 14 through transparent support 20, image-receiving layer 18 and N-oxide containing layer 15. Processing compositions used in such film units are aqueous alkaline photographic processing composition comprising an opacifying system which include a titanium dioxide pigment as the light reflecting agent, preferably in combination with an optical filter agent described in detail in U.S. Pat. No. 3,647,437. When the processing composition is distributed over the N-oxide-containing layer 15, a light-reflecting layer 16 comprising the titanium dioxide is provided between image-receiving layer 18 and N-oxide containing layer 15. This layer 16--at least during processing--presents sufficient opacity to protect the photosensitive system of layer 14 from further photoexposure through transparent support 20. As--and after--reflective-layer 16 is installed, the processing composition permeates N-oxide-containing layer 15 and initiates development of photoexposed photosensitive layer(s) 14 in manners well known in the art to establish an imagewise distribution of diffusible dye developer image-providing material. The diffusible dye developer(s) is transferred through permeable layer 15 and through permeable, light-reflective, titanium dioxide-containing layer 16 to be mordanted, precipitated or otherwise retained in known manner in image-receiving layer 18 where the transfer image is viewed through transparent support 20 against light-reflective layer 16. While there is shown in FIG. 1, the incorporation of an N-oxide into a film unit in the form of an N-oxide-containing layer 15, all or a portion of the N-oxide component desireably included in the film unit can be included in the processing composition utilized for the initiation and development of photosensitive layer(s) 14 as hereinbefore described. Thus, in lieu of N-oxide-containing layer 15, a processing composition initially present in a rupturable container (not shown), and containing an N-oxide and additional components as described, can be distributed between photoexposed photosensitive system 14 and image-receiving layer 18 with provision of reflective layer 16 for the viewing of the dye image in layer 18. FIG. 2 shows an arrangement of essential elements of a film unit of the type described in referenced U.S. Pat. No. 3,594,165 following exposure and processing. The film unit 10a includes a processing composition initially retained in a rupturable container (not shown) and distributed between support 22 and N-oxide-containing layer 25 after photoexposure of photosensitive element(s) 26 through transparent support 22 and layer 25. Processing compositions used in such film units are aqueous alkaline photographic processing compositions which include an opacifying system comprising an opaque pigment which need not be--and usually is not--light reflective. After distribution of the processing composition between transparent support 22 and N-oxide-containing layer 25, an opaque layer 24 is installed which protects photoexposed photosensitive layer 26 from further photoexposure through support 22. Like the film units of FIG. 1, as and after opaque layer 24 is installed, the processing composition permeates N-oxide containing layer 25 and initiates development of photoexposed photosensitive layer 26 to establish imagewise distribution of diffusible dye developers in manners well known to the art. This imagewise distribution is transferred through permeable reflective layer 28 to dye image element 30 where the dye image is viewed through transparent support 32. An opaque layer (not shown) preferably is present between layers 26 and 28. Like the film units of FIG. 1, N-oxide-containing layer 25 need not be employed and N-oxide component can be suitably included in film unit 10a by incorporation into the processing composition utilized for the provision of opaque layer 24. Another diffusion transfer film unit of the present invention is shown in FIG. 3 as 10b. The film unit shown there comprises a photosensitive element having an opaque support 40 carrying a photosensitive system containing layer(s) 42 and an N-oxide containing layer 43. In film units of this type the photosensitive element is photoexposed and a processing composition 44 is then applied over the N-oxide-containing layer 43 as an image receiving element comprising due image layer 46 and opaque support 48 is superposed on the photoexposed photosensitive element. Like the film units of FIGS. 1 and 2, the processing composition permeates N-oxide-containing layer 43 to layer 42 to there establish an imagewise distribution of diffusible dye developers which are transferred through layer 43 to dye image 46. If desired, N-oxide-containing layer 43 can be eliminated from film unit 10b and the N-oxide component can be suitably included in film unit 10b incorporation into processing composition 44 distributed from a suitable rupturable container (not shown). Unlike the film units of FIGS. 1 and 2, the transferred dye image, in the case of film unit 10b, is viewed in layer 46 after separation of the image-receiving element from the photosensitive element. While film unit 10b is shown in FIG. 3 as including an opaque support 48, it will be appreciated that the utilization of a transparent support material in lieu of opaque support 48 will permit the provision of a transparency especially suited to projection viewing. Such a transparency will generally comprise image-containing layer 46 or a suitable transparent support of conventional film base such as polyethylene glycol terephthalate and can be conveniently mounted in known manner for projection viewing. Where a transparency is desirably prepared, development can be conducted in the dark or a removable opaque material can be superposed on the transparent support to permit in-light development and, thereafter, be removed after a suitable imbibition period and image formation. As shown in FIGS. 1-3, a preferred manner of integrating the N-oxides with film units of this invention is by dissolving or dispersing the N-oxide in a suitable matrix material--preferably gelatin--and coating the dispersion as a top layer of the photosensitive system. In this manner, the processing composition--distributed after photoexposure--permeates the N-oxide-containing layer, carrying at least one of the N-oxide to the photoexposed photosensitive system. In accordance with our invention, it is believed that during development of the photoexposed system, the N-oxides provide a beneficial solvating action for unoxidized dye developer--particularly magenta dye developer--thereby improving transfer of unoxidized dye developer without rendering oxidized dye developer more diffusible than the dye developer would be under ordinary development conditions. These beliefs are consistent with our observations that the presence of the N-oxides during development provide more efficient dye transfer, especially more efficient magenta dye transfer. An alternative to the integration into a film unit of N-oxide component in the form of an N-oxide-containing layer comprises the utilization as mentioned hereinbefore in a processing composition employed for initiation and development of a diffusion transfer film unit. The processing compositions employed in diffusion transfer processes of the type contemplated herein usually are aqueous alkaline compositions having a pH in excess of about 12, and frequently in the order of 14 or greater. The liquid processing compositions utilized in the diffusion transfer processes herein comprise at least an aqueous solution of an alkaline material, for example, sodium hydroxide, potassium hydroxide or the like. A suitable N-oxide component as described herein can be included in the processing composition so as to permit permeation of the N-oxide-containing processing composition into the photoexposed emulsion layer(s). The composition can additionally include known silver halide developing agents as auxiliary developers or such materials can suitably be included in the photosensitive element in known manner. The processing composition will preferably include a viscosity-increasing compound constituting a film-forming material of the type which, when the composition is spread and dried, forms a relatively firm and relatively stable film. The preferred film-forming materials disclosed comprise high molecular weight polymers such as polymeric, water-soluble ethers which are inert to an alkaline solution such as, for example, a hydroxyethyl cellulose or sodium carboxymethyl cellulose. Additionally, film-forming materials or thickening agents whose ability to increase viscosity is substantially unaffected if left in solution for a long period of time can also be used. Examples of suitable processing compositions can be found in the aforesaid U.S. Pat. Nos. 2,983,606 and 3,345,163. As has been set forth herein, the aqueous alkaline processing composition will preferably be included in a rupturable or frangible container. In general, such containers comprise a rectangular sheet of fluid-and air-impervious material folded longitudinally upon itself to form two walls which are sealed to one another their longitudinal and end margins to form a cavity in which the processing composition is contained. Examples of suitable rupturable containers and their methods of manufacture can be found, for example, in U.S. Pat. Nos. 2,543,181; 2,634,886; 3,653,732; 3,056,491; 3,152,515. As mentioned, the N-oxides used in the film units of this invention are those having a polarographic reduction potential less positive then the polarographic oxidation potential of the dye developers used in the film unit. More precisely, however, the preferred N-oxides are the pyridine N-oxides conforming the following formula: ##STR2## where each R can be hydrogen or methyl or one of said R groups can be: ##STR3## wherein R 1 is methyl and n is zero or an integer of from 1 to 4. Representative of N-oxide compounds suitable herein are those having the formula: ##STR4## where R 2 and R 3 can be hydrogen or methyl or R 2 can be: ##STR5## Accordingly, specific pyridine N-oxides particularly suitable in the practice of the present invention include the following: ##STR6## Two or more of these N-oxides may be used in the same film unit. All of the above N-oxides are substantially soluble in aqueous alkaline processing compositions and have polarographic reduction potentials less positive than the heterocyclic N-oxide oxidants described in referenced U.S. Pat. No. 3,998,640. It should be appreciated by those skilled in the art that the N-oxide portion of the above compounds may also be represented by the formula: ##STR7## N-oxides of the above formula as well as their preparations are known to the art. For example, they can be synthesized by treating a pyridine of the formula: ##STR8## where each R is as defined before with an oxidizing agent such as peracetic acid, perbenzoic acid or m-chloroperbenzoic acid to yield the corresponding N-oxides. The preferred embodiments of the invention as well as the advantages of the invention will be described in more detail in the following Examples. In all Examples herein, amounts and proportions are by weight. In each of the following Examples, the multicolor photosensitive elements of the film units contained the following cyan, magenta and yellow dye developers. ##STR9## Also, except for variations explained in each following Examples 1 to 3, the film units of each of Examples 1 to 3 were prepared by coating a gelatin-subcoated, 4 mil, opaque polyethylene terephthalate film base with the following layers: 1. a layer of cyan dye developer dispersed in gelatin and coated at a coverage of about 48 mgs./ft. 2 of dye and about 98 mgs./ft. 2 of gelatin; 2. a red-sensitive gelatino silver iodobromide emulsion coated at a coverage of about 100 mgs./ft. 2 of silver and about 125 mgs./ft. 2 of gelatin; 3. a layer of 60-30-4-6 copolymer of butylacrylate, diacetone, acrylamide, styrene and methacrylic acid and polyacrylamide coated at a coverage of about 250 mgs./ft. 2 of the copolymer and about 8 mgs./ft. 2 of polyacrylamide; 4. a layer of magenta dye developer dispersed in gelatin and coated at a coverage of about 59 mgs./ft. 2 of dye and about 52 mgs./ft. 2 of gelatin; 5. a green-sensitive gelatino silver iodobromide emulsion coated at a coverage of about 64 mgs./ft. 2 of silver and about 54 mgs./ft. 2 of gelatin; 6 a layer containing the copolymer referred to above in layer 3 and polyacrylamide coated at a coverage of about 107 mgs./ft. 2 of copolymer and about 2 mgs./ft. 2 of polyacrylamide; 7. a layer of yellow dye developer dispersed in gelatin and coated at a coverage of about 80 mgs./ft. 2 of dye and about 56 mgs./ft. 2 of gelatin; 8. a blue-sensitive gelatino silver iodobromide emulsion layer including the auxiliary developer 4'-methylphenyl hydroquinone coated at a coverage of about 130 mgs./ft. 2 of silver, about 60 mgs./ft 2 of gelatin and about 39 mgs./ft. 2 of auxiliary developer; and 9. a layer of gelatin coated at a coverage of about 40 mgs./ft. 2 of gelatin. A transparent 4 mil polyethylene terephthalate film base was coated, in succession, with the following layers to form an image-receiving component: 1. as a polymeric acid layer, a mixture of about 8:1 of the partial butyl ester of polyethylene/maleic anhydride copolymer and poly (vinyl butyral) at a coverage of about 2,500 mgs./ft. 2 ; 2. a timing layer containing about a 75:1 ratio of a 60-30-4-6 copolymer of butylacrylate, diacetone acrylamide, styrene and methacrylic acid and polyvinylalcohol at a coverage of about 500 mgs./ft. 2 ; and 3. a polymeric image-receiving layer containing a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4-vinylpyridine, at a coverage of about 300 mgs./ft. 2 After photoexposure as described below, the two components were taped together at one end with a rupturable container retaining an aqueous alkaline processing composition so mounted that pressure applied to the container could rupture the container's marginal seal and distribute the processing composition between the image receiving layer and the gelatin overcoat layer of the photosensitive component. (In the commercial production of such film units white tapes are used to tape the components together and these tapes provide a substantially opaque border about the film unit defining an image-viewing area through which a dye image can be viewed. Exposure is also made through this image receiving area.) The aqueous alkaline processing composition comprised: __________________________________________________________________________Potassium hydroxide (85%) 4.58 g.N-benzyl-α-picolinium bromide 1.25 g.(50% solution in water)N-phenethyl-α-picolinium 0.772 g.bromide (50% solution in water)Sodium carboxymethyl cellulose 1.06 g.(Hercules Type 7H4F providing aviscosity of 3,000 cps. at 1%in water at 25° C.) 95% solidsTitanium dioxide 41.8 g.6-methyl uracil 0.29 g.bis-(β-aminoethyl)-sulfide 0.02 g.Lithium nitrate 0.22 g.Benzotriazole 0.56 g.6-methyl-5-bromo-4- 0.03 g.azabenzimidazoleColloidal silica aqueous 0.55 g.dispersion (30% SiO.sub.2)N-2-hydroxyethyl-N,N',N'-tris- 0.83 g.carboxymethyl-ethylene diamineLithium hydroxide 0.2 g.(57.2% solution in water)6-benzylamino-purine 0.39 g.Polyethylene glycol 0.53 g.(molecular weight 6,000) ##STR10## 2.7 g. (Formula OP-1) ##STR11## 0.6 g.water to make 100 g. (Formula OP-2)__________________________________________________________________________ The photosensitive element was exposed to a 2-meter-candle-second light exposure and developed in the dark by distributing the processing composition between the image receiving component and photoexposed photosensitive component. EXAMPLE 1 This Example involves a comparison between a film unit having a pyridine N-oxide present during development and one that does not. Both film units identified as the "Control" and "N-14" below were prepared, photoexposed and processed at 75° F. substantially as described before. However, film unit N-14 had 2-methyl pyridine N-oxide dissolved in water (Formula 3) dispersed in the gelatin layer positioned above the blue sensitive silver halide emulsion layer. This gelatin layer is identified as layer 9 in the earlier description and the amount of 2-methyl pyridine N-oxide dispersed was sufficient to provide a coverage of N-oxide of about 40 mgs/ft. 2 Measurements of the density of dye transferred from unexposed areas (neutral D max ) were made at various increments of time after application of the processing composition and the following data were obtained: TABLE 1__________________________________________________________________________ D-MAX D-MAX D-MAX D-MAX at at at at 0.5 min. 1 min. 1.5 mins. 2 mins. FILM UNIT R G B R G B R G B R G B__________________________________________________________________________CONTROL 0.28 0.28 0.48 0.30 0.35 0.51 0.36 0.42 0.62 0.45 0.50 0.78N-14 0.34 0.33 0.44 0.35 0.36 0.57 0.37 0.47 0.74 0.49 0.61 0.81__________________________________________________________________________ D-MAX D-MAX D-MAX at at at 3 mins. 5 mins. 10 mins. FILM UNIT R G B R G B R G B__________________________________________________________________________CONTROL 0.73 0.68 1.10 1.32 1.10 1.30 1.62 1.69 1.65N-14 0.83 0.84 0.92 1.26 1.34 1.32 1.70 1.75 1.69__________________________________________________________________________ The green D max data of Table 1 are shown in graphical form in FIG. 4. A comparison of the curves of FIG. 4 reveals that slightly higher D max values are obtained at the various times for the film unit N-14 indicating a faster rate of transfer of dye. EXAMPLE 2 This Example involves a comparison between film units substantially the same as the "Control" and film unit N-14 of Example 1. In this Example, the film units were prepared, exposed and processed in the manner described before. However, one set of the Control and film unit N-14 were processed at 40° F., another at 75° F. and still another at 100° F. Density measurements were made of each film unit about an hour after processing and also the magenta saturation of each film unit was measured. The magenta saturation represents the measure of magenta density when the film unit is exposed to two-meter-candle seconds of red and blue light only (no green exposure). The following data were obtained: TABLE 2__________________________________________________________________________ MAGENTA MAGENTA MAGENTA D-MAX SATURATION D-MAX SATURATION D-MAX SATURATION 40° F. 40° F. 75° F. 75° F. 100° F. 100° F.FILM UNIT R G B G R G B G R G B G__________________________________________________________________________CONTROL 2.0 1.92 1.71 .58 1.91 1.66 1.69 .57 1.27 1.35 1.34 .60N-14 2.0 1.92 1.67 .70 2.08 1.97 1.79 .75 1.36 1.58 1.44 .75__________________________________________________________________________ A comparison of the data of Table 2 reveals that film units having N-oxides of the present invention have increased magenta saturation in the magenta column across the temperature range and improved green densities at 75° F. and 100° F. Accordingly, the N-oxides of the present invention are particularly useful for adjusting or otherwise controlling the degree of magenta dye transfer in diffusion transfer film units. EXAMPLE 3 Substantially the same sets of film units as in Example 2 were involved in this Example. However, the sets of film units listed as "L14" below contained pyridine N-oxide (Formula 2) dispersed in the gelatin layer (layer 9) in an amount sufficient to provide a coverage of about 50 mgms./ft. 2 Exposure and processing procedures were substantially the same as in Example 2 and dye density measurements were made on each set of film units after about one hour at 40° F., 75° F., and 100° F. The following data were obtained: TABLE 3__________________________________________________________________________ MAGENTA MAGENTA MAGENTA D-MAX SATURATION D-MAX SATURATION D-MAX SATURATION 40° F. 40° F. 75° F. 75° F. 100° F. 100° F.FILM UNIT P G B G R G B G R G B G__________________________________________________________________________CONTROL 1.90 1.85 1.86 .63 1.89 1.94 2.19 .65 1.27 1.50 1.60 .51L-14 1.93 1.90 2.01 .73 1.98 2.02 2.16 .77 1.22 1.54 1.77 .70__________________________________________________________________________ EXAMPLE 4 Film units, except for the variations set forth herein, were prepared and evaluated in the manner described in Examples 1 to 3. In the case of the film unit of this Example, the multicolor photosensitive element was prepared by coating a gelatin-subcoated, four-mil, opaque polyethylene terephthalate film base, in succession, with the following layers: 1. a layer of cyan dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 69 mgs/ft 2 of dye, about 138 mgs/ft 2 of gelatin, about 25 mgs/ft 2 of 2-phenylbenzimidazole and about 6.3 mgs/ft 2 of 4-methylphenylhydroquinone; 2. a red-sensitive gelatino silver iodobromide emulsion coated at a coverage of about 120 mgs/ft 2 of silver and about 72 mgs/ft 2 of gelatin; 3. a layer of 60-30-4-6 copolymer of butyl acrylate, diacetone acrylamide, styrene, and methacrylic acid and polyacrylamide coated at a coverage of about 232.8 mgs/ft 2 of the copolymer and about 7.2 mgs/ft 2 of polyacrylamide; 4. a layer of magenta dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 60 mgs/ft 2 of dye, about 42 mgs/ft 2 of gelatin, and about 21 mgs/ft 2 of 2-phenylbenzimidazole; 5. a green-sensitive gelatino iodobromide emulsion coated at a coverage of about 74 mgs/ft 2 of silver and about 36 mgs/ft 2 of gelatin; 6. a layer containing the copolymer referred to above in layer 3, polyacrylamide, and succinaldehyde at a coverage of about 127 mgs/ft 2 of the copolymer, about 8.1 mgs/ft 2 of polyacrylamide, and about 6.6 mgs/ft 2 of succinaldehyde; 7. a layer of yellow dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 90 mgs/ft 2 of dye, about 42 mgs/ft 2 of gelatin, and about 19 mgs/ft 2 of 2-phenylbenzimidazole; 8. a blue-sensitive gelatino silver iodobromide emulsion layer including the auxiliary developer 4-methylphenylhydroquinone and coated at a coverage of about 119 mgs/ft 2 of silver, 62 mgs/ft 2 of gelatin, and 19 mgs/ft 2 of auxiliary developer; 9. a layer of gelatin coated at about 45 mgs/ft 2 of gelatin and containing about 4 mgs/ft 2 of carbon black; and 10. a layer of gelatin coated at about 30 mgs/ft 2 of gelatin and containing about 250 mgs/ft 2 of 2-picoline-1-oxide. An image-receiving component was prepared by coating a transparent four-mil polyethylene terephthalate film base, in succession, with the following layers: 1. as a polymeric acid layer, a mixture of about 8:1 of the partial butyl ester of polyethylene/maleic anhydride copylymer and poly(vinyl butyral) at a coverage of about 2500 mgs/ft 2 ; 2. a timing layer containing about a 45:0.7 ratio of a 60-30-4-6 copolymer of butylacrylate, diacetone acrylamide, styrene and methacrylic acid and polyvinyl alcohol at a coverage of about 450 mgs/ft 2 ; and 3. a polymeric image-receiving layer containing, at a coverage of about 300 mgs/ft 2 , a 2:1:1 mixture of polyvinyl alcohol, poly(4-vinylpyridine) and a graft copolymer, the graft copolymer being comprised of 4-vinyl pyridine (4VP) and vinylbenzyl trimethyl ammonium chloride (TMQ) grafted onto hydroxyethyl cellulose (HEC) at a ratio of HEC/4VP/TMQ of 2.2/2.2/1. After photoexposure as described below, the two components were taped together at one end with a rupturable container (retaining an aqueous alkaline processing composition) so mounted that pressure applied to the container would rupture the marginal seal of the container and distribute the processing composition between the image-receiving layer and the N-oxide-containing gelatin layer (layer 10) of the photosensitive element. The photosensitive component was exposed to a two-meter-candle-second light exposure and was developed in the dark by passing the film unit through a pair of rollers spaced at a 0.0032 inch gap so as to uniformly distribute the processing composition between the elements as aforesaid. Development was conducted at a temperature of 75° F. The processing composition had the following composition: Potassium hydroxide (85): 11.02 g. N-phenethyl-α-picolinium bromide (50% solution in water): 2.66 g. Carboxymethyl hydroxyethyl cellulose: 4.18 g. Titanium Dioxide: 78.33 g. 6-methyl uracil: 1.5 g. Benzotriazole: 1.12 g. N-2-hydroxyethyl-N,N'N'-tris-carboxymethyl ethylene diamine: 1.66 g. Colloidal silica aqueous dispersion (30% SiO 2 ): 3.86 g. Polyethylene glycol: 0.94 g. 4-aminopyrazolo-(3,4d) pyrimidine: 0.52 g. 2-(benzimidazolyl methyl) sulfide: 0.083 g. Opacifier dye (Formula OP-1): 2.83 g. Opacifier dye (Formula OP-2): 0.63 g. Water: 100 g. For purposes of establishing a comparative reference, a control film unit (identified in Table 4 as "Control") was prepared and processed in the manner of the film unit of Example 4, except that the photosensitive element of the "Control" film unit contained a gelatin overcoat at a coverage of about 30 mgs./ft 2 in lieu of the N-oxide-containing layer (layer 10) of the photosensitive element of the film unit of Example 4. This Example, thus, permits comparison between a film unit having 2-picoline N-oxide present during development and a film unit ("Control") not having the 2-picoline N-oxide present during development. In the evaluation of the "Control" and Example 4 film units, reflection density measurements were made to determine dye transferred from unexposed areas (neutral D max ) at various specified increments of time after application of the processing composition, as is set forth in the following Table 4 wherein all values of D max are corrected to eliminate contribution to dye density measurements of absorption by the opacification dyes of the processing composition. TABLE 4__________________________________________________________________________ D-MAX D-MAX D-MAX D-MAX D-MAX at 0.5 min. at 1 min. at 1.5 mins. at 2 mins. at 2.5 mins. FILM UNIT R G B R G B R G B R G B R G B__________________________________________________________________________CONTROL 0.14 0.05 0.11 0.12 0.15 1.41 0.26 0.44 1.87 0.46 0.70 1.97 0.97 1.08 2.23Example 4 0.18 0.11 1.16 0.12 0.54 1.68 0.48 0.93 2.03 0.81 1.27 2.21 1.13 1.59 2.31 D-MAX D-MAX D-MAX D-MAX D-MAX at 3 mins. at 3.5 mins. at 4 mins. at 4.5 mins. at 5 mins. FILM UNIT R G B R G B R G B R G B R G B__________________________________________________________________________CONTROL 1.06 1.19 2.23 1.41 1.55 2.41 1.46 1.61 2.35 1.51 1.71 2.40 1.66 1.89 2.4Example 4 1.28 1.81 2.45 1.45 2.01 2.47 1.66 2.15 2.53 1.63 2.23 2.54 1.78 2.27 2.5__________________________________________________________________________ As can be seen from inspection of the data set forth in Table 4, the film unit of Example 4 having a content of 2-picoline N-oxide provided, relative to the "Control" film unit, a faster rate of dye transfer. This rate is especially evident from the reported green D max data pertaining to transfer of magenta dye. EXAMPLE 5 This example illustrates the performance of diffusion transfer film units having an N-oxide component included in the processing composition. Film units were prepared utilizing a multicolor photosensitive element as described in connection with the film unit of Example 4, except that layer 9 was the topmost layer, i.e., no layer 10 was present. The image-receiving element utilized was the element described in Example 4. The processing compositions utilized had the composition set forth in connection with Example 4, except that 4-picoline-1-oxide, in an amount of 3.0 g., was included as an additional ingredient. After photoexposure as described below, the photoexposed and image-receiving components were taped together at one end with a rupturable container (retaining the aqueous alkaline processing composition) so mounted that pressure applied to the container would rupture the marginal seal of the container and distribute the processing composition between the image-receiving layer and the gelatin layer (layer 9) of the photosensitive element. The photosensitive component was exposed to a two-meter-candle-second light exposure and was developed in the dark by passing the film unit through a pair of rollers spaced at a 0.0032 inch gap so as to uniformly distribute the processing composition between the elements as aforesaid. Development was conducted at a temperature of 75° F. For purposes of establishing a comparative reference, a control film unit (identified in Table 5 as "Control") was prepared and processed in the manner of the film unit of Example 5, except that the processing composition of the "Control" film unit contained no added 4-picoline-1-oxide, i.e., the "Control" processing composition was as described in Example 4. Example 5, thus, permits comparison between a film unit having 4-picoline N-oxide present during development, as the result of distribution of processing composition containing 4-picoline-4-oxide, and a film unit ("Control") not having the 4-picoline N-oxide present during development. In the evaluation of the "Control" and Example 5 film units, reflective density measurements were made to determine dye transferred from unexposed areas (neutral D max ) at various specified increments of time after application of the processing composition, as is set forth in the following Table 5 wherein all values of D max are corrected to eliminate contribution to dye density measurements of absorption by the opacification dyes present in the processing composition. TABLE 5__________________________________________________________________________ D-MAX D-MAX D-MAX D-MAX at 0.5 min. at 1 min. at 1.5 mins. at 2 mins.FILM UNIT R G B R G B R G B R G B__________________________________________________________________________CONTROL 0.23 0.29 1.01 0.40 0.37 1.35 0.80 0.78 1.66 1.00 0.98 1.77Example 5 0.25 0.52 1.37 0.38 0.91 1.55 0.68 1.15 1.85 0.93 1.48 1.92 D-MAX D-MAX D-MAX D-MAX at 2.5 mins. at 3 mins. at 5 mins. at 10 mins.FILM UNIT R G B R G B R G B R G B__________________________________________________________________________CONTROL 1.37 1.30 1.91 1.46 1.46 1.93 1.64 1.61 1.98 1.99 1.81 1.91Example 5 1.24 1.71 2.02 1.43 1.89 2.10 1.82 2.15 2.19 2.18 2.19 2.11__________________________________________________________________________ As can be seen from inspection of the data presented in Table 5, inclusion of 4-picoline-N-oxide in the processing composition utilized for the development of the film unit of Example 5 provided, for the most part, a greater rate of dye transfer than was observed in the case of the development of the "Control" film unit. EXAMPLE 6 This example illustrates the utilization of an N-oxide component in a layer of a photosensitive element in the production of a transparency. Film units adapted to the provision of such transparencies were prepared in the following manner. A multicolor photosensitive component was prepared by coating a gelatin-subcoated, four-mil, opaque polyethylene terephthalate film base, in succession, with the following layers: 1. a layer of cyan dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 180 mgs/ft 2 of dye, about 90 mgs/ft 2 of gelatin and about 25 mgs/ft 2 of 4-methylphenyl hydroquinone; 2. a red-sensitive gelatino silver iodobromide emulsion coated at a coverage of about 209 mgs./ft 2 of silver and about 42 mgs/ft 2 of gelatin; 3. a layer of 60-30-4-6 copolymer of butyl acrylate, diacetone acrylamide, styrene, and methacrylic acid, polyacrylamide, and succinaldehyde coated at a coverage of about 252 mgs/ft 2 of the copolymer, about 12 mgs/ft 2 of polyacrylamide and about 7 mgs/ft 2 of succinaldehyde; 4. a layer of magenta dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 120 mgs/ft 2 of dye and about 30 mgs/ft 2 of gelatin; 5. a green-sensitive gelatino iodobromide emulsion coated at a coverage of about 180 mgs/ft 2 of silver and about 36 mgs/ft 2 of gelatin; 6. a layer containing the copolymer referred to above in layer 3, polyacrylamide, and succinaldehyde at a coverage of about 86 mgs/ft 2 of the copolymer, about 10 mgs/ft 2 of polyacrylamide, and about 4 mgs/ft 2 or succinaldehyde; 7. a layer of yellow dye developer (as described in connection with Example 1) dispersed in gelatin and coated at a coverage of about 100 mgs/ft 2 of dye and about 25 mgs./ft 2 of gelatin; 8. a blue-sensitive gelatino silver iodobromoide emulsion layer including the auxiliary developer 4-methylphenyl hydroquinone and coated at a coverage of about 160 mgs/ft 2 of silver, about 32 mgs./ft 2 of gelatin, and about 40 mgs/ft 2 of auxiliary developer; 9. a layer of gelatin coated at a coverage of about 30 mgs/ft 2 of gelatin; and 10. a layer of gelatin coated at about 30 mgs/ft 2 of gelatin and containing about 250 mgs/ft 2 of a picoline N-oxide. In the case of film unit 6A, the picoline N-oxide was 2-picoline N-oxide, while in film units 6B and 6C, the picoline N-oxide was, respectively, 3-picoline N-oxide and 4-picoline N-oxide. An image-receiving component was prepared by coating a transparent four-mil polyethylene terephthalate film base, in succession, with the following layers: 1. as a polymeric acid layer, a mixture of about 8:1 of the partial butyl ester of polyethylene/maleic anhydride copolymer and poly(vinyl butyral) at a coverage of about 2500 mgs./ft 2 ; 2. timing layer of cellulose acetate having a degree of substitution of about 2.4 and coated at a coverage of about 275 mgs./ft 2 ; and 3. a polymeric image-receiving layer containing a mixture of (a) a graft copolymer comprised of 4-vinyl pyridine (4VP) and vinylbenzyl trimethyl ammonium chloride (TMQ) grafted onto hydroxyethyl cellulose (HEC) at a ratio of HEC/4VP/TMQ of 2.2/2.2/1, (b) poly(vinylbenzyl trimethyl ammonium chloride). (c) Pluronic F-127 polyoxyethylene polyoxypropylene block copolymer wetting agent, avg. mol. wt. about 12,500, from BASF Wyandotte Corp., (d) a mixture of cis- and trans-4,5-cyclopentatetrahydropyrimidine-2-thiol, component (a) being coated at a coverage of about 300 mgs./ft 2 , component (b) at about 50 mgs./ft 2 , component (c) at about 10 mgs./ft 2 , and component (d) at about 15 mgs./ft 2 ; and 4. a strip-coat of gum arabic containing ammonium hydroxide and wetting agent coated at a coverage of about 43 mgs./ft 2 . After photoexposure as described below, the photoexposed component and image-receiving component were superposed and taped together at one end with a rupturable container (retaining an aqueous alkaline processing composition) mounted therebetween such that pressure applied to the container would rupture the marginal seal of the container and distribute the processing composition between the image-receiving layer and the N-oxide-containing gelatin layer (layer 10) of the photosensitive component. The photosensitive component was exposed to a two-meter-candle-second light exposure and was developed in the dark by passing the film unit through a pair of rollers spaced at a 0.0030 inch gap so as to uniformly distribute the processing composition between the components as aforesaid. Development was conducted at a temperature of 75° F. The image-receiving component was, after a period of imbibition specified in Table 6, peeled apart from the developed photosensitive component. The processing composition utilized in the film units had the following composition: Sodium hydroxide: 7.0 g. Zinc nitrate: 0.6 g. 6-benzylamino purine: 1.0 g. N-benzyl-α-picolinium bromide: 2.0 g. N-phenethyl-α-picolinium bromide: 1.5 g. 4-aminopyrazolo-(3,4d) pyrimidine: 1.0 g. Hydroxyethyl cellulose: 2.0 g. Benzotriazole: 3.0 g. Water: 100 g. For purposes of establishing a comparative reference, a control film unit (identified in Table 6 as "Control") was prepared and processed in the manner of the film units of Example 6, except that the photosensitive element of the "Control" film unit contained a layer of gelatin coated at a coverage of about 30 mgs/ft 2 in lieu of the N-oxide-containing layer (layer 10) of the photosensitive elements of the film units of Example 6. This Example, thus, permits comparison between film units having a picoline N-oxide present during development and a film unit ("Control") not having the picoline N-oxide present during development. In the evaluation of the "Control" and Example 6 film units, transmission density measurements were made to determine dye transferred from unexposed areas (neutral P max ) at various specified increments of time after application of the processing composition, as is set forth in the following Table 6. TABLE 6__________________________________________________________________________ D-MAX D-MAX D-MAX at 0.5 min. at 1 min. at 1.5 mins. FILM UNIT R G B R G B R G B__________________________________________________________________________CONTROL 0.28 0.46 1.13 0.85 1.09 1.78 1.49 1.55 2.02Example 6A (2-Picoline-N-Oxide) 0.35 0.57 1.01 1.13 1.14 1.44 1.72 1.39 1.55Example 6B (3-Picoline-N-Oxide) 0.36 0.78 1.35 1.06 1.46 1.96 1.68 1.88 2.12Example 6C (4-Picoline-N-Oxide) 0.37 0.71 1.26 1.03 1.40 1.82 1.70 1.80 2.08 D-MAX D-MAX D-MAX at 2 mins. at 2.5 mins. at 3 mins. FILM UNIT R G B R G B R G B__________________________________________________________________________CONTROL 1.95 1.70 1.83 2.12 1.72 1.90 2.42 1.89 1.98Example 6A (2-Picoline-N-Oxide) 2.04 1.81 1.79 2.32 1.86 1.83 2.72 2.06 1.96Example 6B (3-Picoline-N-Oxide) 2.21 2.07 2.20 2.44 1.96 2.04 2.66 2.20 2.11Example 6C (4-Picoline-N-Oxide) 2.18 2.03 2.17 2.58 2.25 2.26 2.78 2.34 2.24__________________________________________________________________________ As can be seen from inspection of the results reported in Table 6, incorporation of an N-oxide component in the photosensitive components of film units 6A through 6C provided, relative to the "Control" film unit, a greater rate of dye transfer. EXAMPLE 7 This Example illustrates the utilization of an N-oxide component in a processing composition employed for the processing of a diffusion transfer film unit adapted to the provision of a transparency image. Film units were prepared from photosensitive and image-receiving elements and processing compositions as described herein and were processed and evaluated in the manner described in Example 6. The multicolor photosensitive component utilized in the film units of this Example, identified in Table 7 as film units 7A through 7C, was the photosensitive component described in Example 6, except that the #10 layer was not employed, i.e., the outermost layer was the gelatin layer (layer #9) at a coverage of about 30 mgs./ft 2 . Film units 7A through 7C included as an image-receiving component, the image-receiving component described in detail in Example 6. The processing compositions of film units 7A through 7C had the following composition: Sodium hydroxide: 7.0 g. Zinc nitrate: 0.6 g. 6-benzylamino-purine: 1.0 g. N-benzyl-α-picolinium bromide: 2.0 g. N-phenethyl-α-picolinium bromide: 1.5 g. 4-amino-pyrazolo (3,4d) pyrimidine: 1.0 g. Hydroxethyl cellulose: 2.0 g. Picoline-N-oxide*: 3.0 g. Water: 100 g. The film units of this Example were photoexposed and processed in the manner described in Example 6. As a "Control" film unit, a film unit utilizing the same photosensitive and image-receiving components as film units 7A through 7C were prepared. The processing composition utilized in the "Control" film unit included no N-oxide component and had the following composition: Sodium hydroxide: 7.0 g. Zinc nitrate: 0.6 g. 6-benzylamino-purine: 1.0 g. N-benzyl-α-picolinium bromide: 2.0 g. N-phenethyl-α-picolinium bromide: 1.5 g. 4-amino-pyrazolo (3,4d) pyrimidine: 1.0 g. Hydroxyethyl cellulose: 2.0 g. Water: 100 g. The "Control" and film units 7A through 7C were evaluated in the manner described in Example 6 and dye density measurements were made at specified increments of time after application of the process composition and the following results were obtained and are set forth in Table 7. TABLE 7__________________________________________________________________________ D-MAX D-MAX D-MAX at 0.5 min. at 1 min. 1.5 mins. FILM UNIT R G B R G B R G B__________________________________________________________________________CONTROL 0.26 0.35 1.02 0.74 0.81 1.47 1.29 1.13 1.60Example 7A (2-Picoline-N-Oxide) 0.31 0.82 1.60 0.95 1.52 2.03 1.67 1.97 2.31Example 7B (3-Picoline-N-Oxide) 0.33 0.84 1.57 1.14 1.62 1.96 1.55 1.81 2.11Example 7C (4-Picoline-N-Oxide) 0.37 0.90 1.63 1.07 1.60 2.17 1.75 1.94 2.31 D-MAX D-MAX D-MAX 2 mins. 2.5 mins. at 3 mins. FILM UNIT R G B R G B R G B__________________________________________________________________________CONTROL 1.68 1.37 1.82 2.05 1.52 1.82 2.28 1.66 1.89Example 7A (2-Picoline-N-Oxide) 2.11 2.15 2.37 2.52 2.30 2.42 2.60 2.31 2.40Example 7B (3-Picoline-N-Oxide) 2.07 2.17 2.18 2.46 2.23 2.24 2.56 2.22 2.22Example 7C (4-Picoline-N-Oxide) 2.20 2.09 2.28 2.59 2.28 2.30 2.72 2.35 2.32__________________________________________________________________________ From inspection of the results set forth in Table 7, it can be seen that the incorporation of an N-oxide component in a processing composition utilized for the processing of a diffusion transfer image provides an increased rate of dye transfer relative to the rate of dye transfer obtained in the case of the processing of a corresponding film unit with a processing composition not including such an N-oxide component.

This invention is concerned with the use of certain pyridine N-oxides in diffusion transfer products and processes employing dye developers.

FIELD OF THE INVENTION The present invention relates generally to software and/or hardware, and more particularly, to a license validation system which enables or disables software and/or hardware. BACKGROUND OF THE INVENTION Software piracy costs software manufacturers hundreds of millions annually in lost sales. Software piracy can take many forms. Although the most common form is to make unlawful copies of software, other forms include unlawfully enabling and using unpaid for software features in otherwise validly licensed software and using validly licensed software outside of permissible geographic parameters. In the latter situation, globally sold software has different pricing structures based on different geographic regions. The differing pricing structures depend on a variety of factors, including exchange rate, demand, and the socioeconomic status of the region. For example, software are often sold at higher prices in the U.S., Japan, South Korea, and Europe but at lower prices in lesser developed countries such as China. Obviously, there is a great financial incentive to buy “gray market” software in China when they are destined for use in the U.S., Japan, South Korea, or Europe. One method uses serial number information (e.g., medium access control or MAC address) to associate licensed software with corresponding hardware and uses differing hardware identifiers for differing price regions. In this method, a valid license file is required to run a computational component. The license file contains a serial number that must be present on the hardware that is to execute the licensed software for the license to be valid and the software to be executable. In telecommunication applications, for example, the serial number of the control processor must be in the license file for the control processor to run the licensed software. The hardware identifiers are differing versions or ranges of the serial numbers, such that a specified region has a serial number of a particular format or within a particular range. When the system determines whether a valid license file is present, one of the checks is to determine whether or not the license has expired based on the system clock value and another is to determine for a stored region code set by the manufacturer that the serial number is correct for the corresponding region. This method is discussed in copending U.S. patent applications entitled “Securing Feature Activation in a Telecommunication System”, Ser. No. 09/357,679, filed Jul. 20, 1999, to Serkowski; “License Modes in Call Processing”, Ser. No. 10/232,508, filed Aug. 30, 2002; “Remote Feature Activator Feature Extraction”, Ser. No. 10/232,906, filed Aug. 30, 2002; “Flexible License File Feature Controls”, Ser. No. 10/231,999; “License File Serial Number Tracking”, Ser. No. 10/232,507; “Licensing Duplicated Systems”, Ser. No. 10/231,957; “Software Licensing for Spare Processors”, Ser. No. 10/232,647; “Temporary Password Login”, Ser. No. 10/387,182; and “Ironclad Notification of License Errors”, Ser. No. 10/405,176; each of which is incorporated herein by this reference, and is currently being implemented commercially in Communication Manager™ by Avaya, Inc.™. The use of the system clock setting to determine whether or not the license has expired can be circumvented by the licensee. As will be appreciated, software licenses can be limited or unlimited in duration. Licenses that are limited in duration are often much less expensive to purchase than those that have longer durations or unlimited durations. By adjusting the system clock setting, an unscrupulous licensee can indefinitely extend the duration of a limited duration license beyond its otherwise permissible duration and thereby gain a substantial and illegal windfall. Moreover, the use of a region code or location feature coupled with a specific serial number provides only weak security against geographic software piracy. The mechanism addresses only gray market hardware issues. It does not address gray market software concerns. SUMMARY OF THE INVENTION The present invention is directed to solving these and other needs. According to the present invention, positional and/or temporal awareness of a key device and/or computational component attempting to validate the existence of a valid license is used during the license validation process. In one embodiment of the present invention, a method for validating an intended use of a computational component is provided that includes the steps of: (a) receiving Global Positioning System (GPS) information from a GPS receiver, the GPS information comprising one or more of (i) a geographic location and (ii) a clock setting, the geographic location being associated with the location of the computational component and/or a key device in communication with the computational component; (b) performing one or more of the following steps: (i) comparing the geographic location with the predetermined geographic location permitted by the license; and (ii) comparing the clock setting with the expiration date of the license; and (c) when the geographic location is not a permitted geographic location under the license and/or when the clock setting is outside of the permissible term of the license, determining that use of the computational component is not permitted. When the clock setting is within the permissible license term, the geographic location is a permitted geographic location under the license, and/or other criteria are satisfied, the intended use of the computational component is valid. By using the GPS timing information to determine whether or not the license has expired rather than the system clock setting, the licensee is unable to extend the license beyond its otherwise permissible term. By determining the geographic location of the computational component and/or key device, the methodology can prevent the gray market use of the computational component. The geographic location may be determined by any suitable technique, with a location determination by a Global Positioning System or GPS receiver being preferred due to its accuracy (within 100 meters), low cost, and ready availability. For more efficient processing, the GPS coordinates, which are typically expressed as a pairing of latitude and longitude, are converted into a region code by mapping the coordinates against a conversion table. The predetermined geographic location permitted by the license can be expressed as one or a number of region codes. Alternatively, the determination of proper geographic use of the computational component can be based on the absence of the region code corresponding to the current geographic location from a set of region codes. Typically, the GPS module is located in the key device, which is commonly configured as a dongle. The preferred type of dongle is a smart card. The key device is typically required to activate the computational component. In other words, the computational component cannot be operated or executed unless the key device is in communication with the component. To ensure that a valid key device is used to activate or execute the computational component, the key device is preferably authenticated by the computational component using suitable authentication information (e.g., a serial number associated with the key device and/or computational component). To be successfully authenticated, the serial number provided by the key device must match a serial number stored in the computational component, typically in a license file. Unless properly authenticated, the key device is not recognized by the computational component. The key device can be configured to prohibit operation over a large network. A dishonest user can set up a computational system such that the computational component is running in a different region or country than the region or country where the key device is located. Although having a key device in one region to activate hardware/software in another distant region is a great inconvenience, such license abuse is not inconceivable if the cost savings to the user are large. To further illustrate this embodiment, an operational description of a preferred configuration of the embodiment is provided. In the configuration, the licensed application makes periodic smart card queries to validate the license. In response to a query, the smart card translates the location determined by the GPS receiver into a region code and returns the region code to the licensed application along with the serial number. In this configuration, the license file would specify the region code(s) in which the software is licensed to operate based on what the customer ordered. If the region code returned to the application were not an allowed region code as defined in the license file, the software would not function. The smart card query from the licensed application can include the region code from the license. The smart card would then only return a serial number response if the GPS-determined position matched the region code in the query. Although such smart cards may not be inexpensive (approximately $200 per copy by today's pricing), for medium and high value software the expense can be justified if the cost differential between regions is significant. GPS chips are expected to drop dramatically in cost as they become mass-market items in cell phones and other mobile devices. These and other advantages and features of the invention will become apparent from the following description of the invention taken together with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram representation of a dongle according to an embodiment of the present invention; FIG. 2 is a flow chart illustration of the operational steps performed by a license validation agent in a computational component seeking license validation; FIG. 3 is a flow chart illustration of the operational steps performed by a validation agent in the dongle of FIG. 1 ; and FIG. 4 is a block diagram representation of the dongle of FIG. 1 in communication with the computational component performing license validation. DETAILED DESCRIPTION Referring to FIG. 1 , a dongle 100 of one embodiment of the present invention is depicted. The dongle 100 includes a port 104 , a Global Positioning System or GPS module 108 coupled to an antenna 112 , a processor 116 , a memory 120 and an optional power source 124 . As can be seen from FIG. 4 , the dongle 100 communicates with a computational component 400 attempting to validate the existence of a valid license. The port 104 of the dongle 100 typically connects to a port on the computational component 400 attempting to successfully validate the existence of a valid license for the intended operation of the computational component. The computational component 400 can be any entity capable of performing a task or executing instructions, e.g., a logic-containing board or chip such as an application specific integrated circuit or ASIC, a (control) processor, software, etc. In one configuration, the computational component 400 is a license-controlled telecommunication application. The port 104 may be adapted to be connected to a parallel port, a serial port, or any other type of port which may be available for data transfer, including a universal serial bus (USB) port. The GPS module 108 can be any suitable software and/or hardware for receiving GPS signals and determining the current GPS timing information (e.g., a clock setting including one or more of time of day, day of month, month of year, and year) and the module's current location expressed in GPS coordinates (e.g., a latitude and longitude pairing). The GPS module 108 is in communication with the antenna 112 to receive the GPS signals. The processor 116 can be any functional unit that interprets and executes instructions or processes coded instructions and performs a task. A processor typically includes an instruction control unit and an arithmetic and logic unit. Typically, the processor 116 is a microprocessor. The memory 120 can be any suitable medium containing addressable storage space. The memory can be volatile storage and/or nonvolatile storage and can be read-only and/or random access. Typically, the memory is in the form of EEPROM. The power source 124 , which is optional, can be any suitable power supply. The power source is optional in that power could be received entirely from the computational component with which the dongle 100 is engaged or from a separate power supply. The memory 120 includes a dongle validation agent 128 to interact with the computational component 400 and GPS module 108 during the license validation process and various data structures, including the conversion table 132 , which maps GPS coordinates against region codes, and authentication information 136 , which authenticates the dongle 100 to the computational component 400 . The dongle validation agent 128 provides to a licensing validation agent 404 in the computational component 400 ( FIG. 4 ) the authentication information 136 , GPS timing information, and a region code (after mapping the GPS coordinates against the conversion table 132 ). The conversion table 132 typically is a listing of GPS coordinate ranges (e.g., a range of latitudes and a corresponding range of longitudes) against a corresponding region code. The authentication information 136 typically includes a unique identifier associated with the dongle 100 and/or computational component, such as a serial number, a MAC address, a secret and/or public algorithm and/or key, a digital certificate, and the like. Preferably, authentication is done using a secret, such as a secret algorithm, key, and/or certificate. Authentication is important as it prevents an unauthorized dongle from being used with the computational component. In a preferred configuration, the identifier is a serial number of a board in the computational component. Nothwithstanding the specific configuration of the dongle 100 in FIG. 1 , it is to be understood that the dongle can be in a multitude of other configurations. The dongle can be any hardware key that attaches or otherwise communicates with a computational component and that must be present (or in communication with the component) to run or execute a particular piece of software and/or operate hardware. It may be programmable or non-programmable. The dongle can be a smart card, PCI board, or other electronic device. The joint operation of the licensing validation and dongle validation agents 404 and 128 will now be described with reference to FIGS. 2 and 3 . FIG. 2 describes the operation of the licensing validation agent 404 while FIG. 3 the operation of the dongle validation agent 128 . Referring to FIG. 2 , the licensing validation agent 404 first determines in decision diamond 200 whether or not the dongle 100 is present or in communication with the computational component 400 . If the dongle 100 is not in communication with the component 400 , the agent 404 determines in step 204 that the license is invalid. The consequences of such a determination depend on the application but can include completely disabling the software, disabling only selected features of the software, providing a warning to administration followed by complete or partial disablement of the software after a determined period, and the like. If the dongle 100 is in communication with the component 400 , the agent 404 proceeds to step 208 . In step 208 , the agent 404 requests authentication information from the dongle validation agent 128 . In step 300 of FIG. 3 , the dongle validation agent 128 receives the request and, in step 304 , retrieves the authentication information and sends the information to the licensing validation agent 404 . In decision diamond 216 ( FIG. 2 ), the licensing validation agent 404 compares the authentication information received from the dongle validation agent 128 with the authentication information stored in the memory (not shown) of the component 400 . If the differing sets of authentication information do not match, the agent 404 proceeds to step 204 . If they are identical, the agent 404 proceeds to step 217 . In step 217 , the validation agent 404 requests GPS timing information from the dongle validation agent 128 . In step 305 of FIG. 3 , the dongle validation agent 128 receives the request and, in step 306 , obtains the GPS timing information from the GPS module 108 . The GPS timing information is sent to the validation agent 404 in step 307 . When the GPS timing information is received by the validation agent 404 in step 218 , the validation agent 404 in decision diamond 219 compares the timing information (e.g., clock setting) against the expiration date of the license. When the tinting information corresponds to a time after the expiration date, the agent 404 proceeds to step 204 . When the timing information corresponds to a time before the expiration date and within the license term (e.g., after the start time of the license term), the agent 404 concludes that the license is unexpired and proceeds to decision diamond 220 . In decision diamond 220 , the agent 404 determines if the dongle 100 is “local” to the computational component 400 . As will appreciated, a dishonest user can set up a computational system such that the computational component 400 is running in a different region or country than the region or country where the dongle 100 is located. Although having a dongle 100 in one region to activate hardware/software in another distant region is a great inconvenience, such license abuse is not inconceivable if the cost savings to the user are large. To address this concern, the dongle 100 is configured to prohibit operation over a large network. Specifically, it can be configured to operate only as a local device without network capabilities. For example, the dongle 100 is not allowed to have an IP or MAC address that is not within a range of IP addresses or MAC addresses, respectively, defining the computational component or a network or subnetwork containing the component or may be required to have an IP address that is the same as a network interface card (not shown) associated with the computational component 400 (but can have a port number that is different from the port number of the card). Alternatively, the communication protocol between the computational component 400 and the dongle 100 could be designed to work only in a low-latency environment, such that the protocol would fail if the physical separation (as embodied by the communication medium 408 ) between the component 400 and the dongle 100 ( FIG. 4 ) were too great. For example, a maximum time delay between the time a request is made by the component 400 to the dongle 100 and the time a response to the request is received by the component 400 from the dongle 100 may be specified. When the time delay between request and response equals or exceeds the maximum time delay, the dongle 100 is not considered to be local to the computational component. Likewise when the time delay is less than the maximum time delay, the dongle 100 is considered to be local. When the dongle 100 is not found to be local to the component 400 , the agent 404 proceeds to step 204 . When the dongle 100 is found to be local to the component 400 , the agent 404 proceeds to step 224 . In step 224 , the agent 404 requests geographic location information from the dongle validation agent 128 . In step 308 of FIG. 3 , the request is received by the dongle validation agent 128 . In steps 312 , 316 , and 320 of FIG. 3 , the dongle validation agent 128 respectively obtains the geographic coordinates from the GPS module 108 , converts the geographic coordinates into a corresponding region code by mapping the coordinates against the conversion table 132 , and sends the region code to the licensing validation agent 404 . Returning again to FIG. 2 , the agent 404 in decision diamond 232 determines whether the dongle's geographic location is within a predetermined region or collection of region codes. As will be appreciated, regions having similar pricing structures can be grouped together for purposes of acceptable areas of operation for software purchased in any of the similarly priced regions. Moreover, when the computational component is purchased in a region having a higher pricing structure it can be used in different regions having a lower pricing structure but not vice versa. Thus, if a customer purchased software at a lower price in China, it could not use the software in the U.S. where the software is selling at a higher price. However, if the customer purchased the software in the U.S. it could use the software in China. If not, the agent 404 proceeds to step 204 . If so, the agent 404 proceeds to step 236 and determines that the license has been successfully validated. This determination permits the computational component to operate as permitted by the terms of the license. After either of steps 204 or 236 , the agent 404 proceeds to step 240 and waits a predetermined period. After the predetermined period, the validation process described above is repeated. The duration of the predetermined period depends on the application. A number of variations and modifications of the invention can be used. It would be possible to provide for some features of the invention without providing others. For example, the division of the various functions performed by the validation agents 128 and 404 can be different. For example, the dongle validation agent 128 can perform authentication (steps 208 - 216 ), locality determination (step 220 ), and/or geographic location permissibility (decision diamond 232 ) and notify the licensing validation agent 404 of the result. The steps of FIGS. 2 and 3 can be performed in a different order. For example, steps 208 - 216 can be performed after decision diamond 220 . Steps 224 - 232 can be performed before either of steps 208 - 216 and decision diamond 220 . The licensing validation agent and dongle validation agent can be implemented as software, hardware, or a combination thereof. The dongle validation agent can, for example, be implemented as firmware. In another embodiment, the GPS module is located in the computational component and a key may or may not be used. In this embodiment, the licensing validation agent interfaces directly with the GPS module and maps the GPS coordinates to a collection of region codes. In yet another embodiment, the requirements for a permissible use of the computational component are not stipulated by a license. For example, the requirements can be stipulated in laws, regulations, policies or rules. The present invention, in various embodiments, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation. The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. Although the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

A system for validating a license to use a computational component, comprising (a) a GPS module 108 to determine one or more of GPS timing information and a geographic location of at least one of the computational component 400 and a key device 100 in communication with the computational component 400 and (b) a validation agent 128 and/or 404 operable to (a) compare the GPS timing information against the license expiration date and/or compare the geographic location with at least one predetermined geographic location permitted by the license and (b), when the GPS timing information is outside of the permissible license term and/or when the geographic location is not a permitted geographic location under the license, determine that the computational component 400 is not validly licensed.

FIELD OF THE INVENTION The invention relates to spectrometers. BACKGROUND OF THE INVENTION Spectrometers are widely used in both research and industry for analysis, detection, and confirmation of material composition. In recent years, handheld spectrometers operating in the visible, near infrared, and mid infrared spectral ranges have been prolific and been sold into numerous markets. Spectrometers are used to analyze materials often in order to determine elemental or molecular composition. The more wavelength resolution and/or spectral bandwidth, i.e. wavelength range that a spectrometer is capable of, the more compositional information can be attained which in turn leads to the ability to analyze more complex materials and mixtures. Another important aspect of small handheld spectrometers is measurement speed. Users are typically able to hold a portable spectrometer up to a sample for seconds and even up to a minute, but much longer than this leads to fatigue and the inability to measure many samples quickly. Yet another important characteristic of portable spectrometers is overall cost. Finally, and perhaps most important for portable spectrometers, is instrument reliability and overall ruggedness for field use. One common portable spectrometer design employed by Ocean Optics, Stellar Net, Avantes, Thermo Fisher Scientific and multiple other vendors for the deep UV to near infrared wavelength range (200 to 1100 nm) utilizes inexpensive silicon based CCD linear array detectors. The design eliminates the need for the older scanning gratings and basically dedicates each pixel in the linear array detector to a particular small wavelength range. The advantage is no moving parts, small size, ruggedness, and low cost. These spectrometers typically have several thousand pixels and can be designed for a small slice of the UV-VIS-NIR spectrum with high resolution or a larger slice with lower resolution. Similar spectrometers are also available at longer wavelengths in the Near Infrared (NIR) beyond where silicon detectors function. These spectrometer (offered by the same vendors previously mentioned) typically utilize Indium Gallium Arsenide (InGaAs) detector arrays. While these function well, the disadvantage is that they are extremely expensive in comparison to silicon arrays and depending on desired performance and they usually require cooling. The cooling adds to volume and power consumption making these devices less portable. An optional NIR portable spectrometer configuration is to use a single small element InGaAs detector in conjunction with a MEMS light modulator. Polychromix successfully introduced such a portable spectrometer in 2006. Similar designs can be found in the literature using Texas Instrument's digital micro-mirrors as well. See also U.S. published application No. 2008/0174777 incorporated herein by this reference. There is currently not a large selection of portable spectrometers with both a wide spectral range and high resolution on the market. Spectral Evolution and ASD offer reasonably high resolution spectrometers that cover the wide range of roughly 400 to 2500 nm but do so with the added drawbacks of size, weight, and expense. Internally, these units consist of multiple versions of the spectrometers previously described. An optional design for high resolution wide spectral range spectrometers is the Echelle spectrometer. These spectrometers use a two dimensional detector and a cross dispersing element (such as a prism) in addition to the usual diffraction grating to spread spectrum in two dimensions across both dimensions of the detector. A limiting factor of this type of design remains that the currently available detectors cannot cover the wide range from 400 to 2500 nm. For example, silicon detectors always lose sensitivity above 1100 nm. While it is feasible for certain InGaAs detectors to work over nearly this entire range, the cost is even more prohibitive that that of the linear (1D) InGaAs arrays. SUMMARY OF THE INVENTION One advantage of the spectrometer described in this application is high resolution, wide spectral range, low cost, low weight, and high durability/ruggedness. It would be useful to have a small spectrometer, suitable for handheld operation, that can cover an even wider range than current commercial devices. Currently available wide range spectrometers, such as those from Spectral Evolution or ASDI often contain three separate optical spectrometers to cover the range and thus are larger, heavier, and more expensive than a single spectrometer that could handle the entire range. A multi-diffraction order grating and digital micro-mirror device (DMD) which serves as a light modulator, can be used in combination to provide ultra-compact spectrometers covering large wavelength ranges. This type of wide range spectrometer, potentially covering UV, visible, and near infrared, can be used for various kinds of material and chemical identification. Featured is a wide spectral range spectrometer comprising a source of electromagnetic radiation and an optical subsystem configured to disperse said radiation into a plurality of wavelengths. A pixilated light modulator (e.g., a DMD) receives the radiation wavelengths and is configured to direct one or more selective wavelengths to a sample. In one example, the optical subsystem may include a grating (e.g., an Echelle type grating) oriented to disperse said radiation in one plane and a prism configured to disperse said radiation in another plane. A focusing lens may be located between the prism and the pixilated light modulator. Preferably, the prism may be between the grating and the pixilated light modulator. The prism may be between the grating and pixilated light modulator and also between the source and the grating. The spectrometer may further include a lens between the source and the prism and between the prism and the pixilated light modulator for collimating radiation from the source and focusing radiation from the prism. The lens may be further located between the pixilated light modulator and the sample to focus radiation from the pixilated light monitor onto the sample. The spectrometer typically also includes at least one detector responsive to radiation from the sample, e.g., an InGaAs and/or a silicon detector. The source may be a visible source, a near infrared source, or a mid-infrared light source. The digital micro mirror device may have individually operable mirrors in a two dimensional array. A controller is configured to selectively actuate different mirrors. The controller can be programmed to control the digital micro mirror device to sequentially direct different wavelengths to the sample and/or the controller can be programmed to control the digital micro mirror device to direct multiple wavelengths to the sample simultaneously. Also featured is a spectrometer method comprising dispersing radiation from a source into a plurality of wavelengths, directing said wavelengths to a pixilated light modulator, and controlling the pixilated light monitor to direct one or more wavelengths to a sample. Dispersing radiation may include dispersing radiation in one plane and then dispersing said radiation in another plane. The method may further include focusing said wavelengths onto the pixilated light modulator. The method may further include focusing and collimating radiation from the source using a single optic. Also featured is a method comprising projecting cross dispersed light onto a micro mirror array having a plurality of individual mirrors, activating individual mirrors following a selective sequence of mirror combinations to direct an individual wavelength or individual wavelengths to a sample, detecting a signal reflected by the sample for each mirror combination, and recovering a complete spectrum by recombining data from signals according to the collection sequence in use. The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which: FIG. 1 is a schematic diagram of one embodiment of a wide range spectrometer according to this invention; FIG. 2 is a schematic diagram of a second embodiment of this invention modified to a more compact format; and FIG. 3 is a schematic diagram of a third embodiment of this invention showing very compact construction with fewer optical components. DETAILED DESCRIPTION OF THE INVENTION Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. FIG. 1 shows an example of spectrometer 10 with a pixilated light modulator associated with the source. The spectrometer need not be a complete device and may include only the source section without detection optics and/or components. Electromagnetic radiation from a source filament 12 passes through a slit 14 and through a collimating lens 16 . Collimated light is diffracted from a grating 18 that disperses the light as a function of wavelength in the plane of the diagram. The light then passes through a prism 20 which further disperses the light in the out-of-diagram-plane direction. The prism 20 acts as a diffraction order separator. Light from the prism 20 then passes through a focusing lens 22 and onto a micro-electromechanical (MEM) digital micro-mirror device (DMD) array 24 . The focusing lens focuses each wavelength to a small separate area on the DMD micro-mirror array. The DMD has a large number of mirrors (in some cases over 1 million) that can be individually programmed to one of two possible tilt angles. Typically, the Texas Instruments DMDs can be set to the plus 12 degree or −12 degree position. The mirror positions can be electronically modulated by controller 50 at very high speeds enabling wavelengths of light hitting a particular area to be directed to the sample focusing lens 26 . Light passing the sample focusing lens 26 is then directed toward the sample 28 of interest (i.e. the material under test). In a complete spectrometer, diffusely scattered light from the sample is then collected by an optional collection lens 30 and directed to the detector 32 . Wavelengths can be selected via the mirrors in a timed sequence, which in turn, are directed toward the sample. In this fashion, a full spectrum can be collected by the single element detector 32 as the mirror sequence is carried out. In addition, multiple wavelengths may be directed simultaneously toward the detector making possible the implementation of digital transform spectroscopy. Once such example is known as the Hadamard Transform including a series of wavelength combinations (“masks”) that are measured in sequence. After collecting intensity as a function of the Hadamard mask number, a mathematical transform is applied to yield the final spectrum. The advantage of digital transform methodology is that for a given amount of data collection time the signal to noise ratio can be increased by: Signal to noise improvement=root(number of pixels/2)  (1) The net improvement increases significantly when the number of pixels is high. A Hadamard transform using 20,000 pixels (or wavelength zones) would yield a signal to noise improvement of 100 over the more traditional process of measuring one pixel or wavelength zone) at a time. The grating 18 may be an Echelle type grating which is typically used at high angles of incidence (relative to the surface normal) for which the diffracted light contains many overlapping orders. The overlaps are separated via the prism 20 which is situated so that its dispersion direction is normal to that of the diffraction grating 18 . The grating 18 may also be a traditional grating designed for a lower angle of incidence to the grating surface normal. One example would be a grating designed for efficient first order diffraction of light from 1400 nm to 2800 nm. Such a grating also diffracts shorter wavelengths at exactly the same angles. For this particular grating second order diffraction of wavelengths from 700 to 1400 nm would be superimposed on the 1400 to 2800 nm light. In the same vain, third order diffraction from 350 to 700 nm wavelengths would be superimposed in the same fashion. A conventional spectrometer would use a high pass optical filter to prevent the shorter wavelengths from the light entering the spectrometer. However, in this invention, the 2 nd order diffraction (from 700 to 1400 nm) and 3 rd order diffraction (from 350 to 700 nm) light is separated by the prism 20 so that light hitting, the DMD 24 would actually be separated into three separate spectral lines spread across the surface. This is similar to the function of a traditional Echelle spectrometer which would place a 2 dimensional CCD at the location of the DMD 20 in FIG. 1 . One advantage of using a DMD associated with the source as taught in this invention is that the light can be modulated before being directed to the sample. This allows for automatic rejection of stray light from the environment. The detector can be used to only detect the amplitude of the modulated signal (that light passing the DMD 24 ) and ignore constant signals (those from the environment). As a result of the ability for this configuration to reject constant signals (non-modulated signals), the detector dark current and stray light within the spectrometer are also automatically rejected in addition to environmental stray light. This is very important advantage of this spectrometer design and allows for much more precise measurement and detection of very small sample differences. Yet a further advantage of this design is that only a single detector element may be required. Currently, two dimensional detectors are only available over certain wavelength ranges. However, a stacked InGaAs—extended InGaAs single element detector has sensitivity over the large range of 400 to 2600 nm and is quite inexpensive. This is a very large wavelength range and is important for certain application areas such as mining and mineral identification, and for fruit and grain analysis. Currently available equipment that covers this range is large, bulky and expensive. The spectrometer disclosed here can be made with a volume approaching that of a cell phone. A silicon detector may also be used alone or in conjunction with an InGaAs detector. A second embodiment is shown in FIG. 2 . In this example, the collimating lens 16 and the focusing lens 22 are combined into one optic. In addition, the prism 20 is placed adjacent to the diffraction grating 18 . In this configuration, light passes through the prism twice (before and after reflection off the surface of grating 18 ) yielding twice the order separating power. Significant space is conserved by this configuration as well. A third embodiment is shown in FIG. 3 . In this example, the collimating lens 16 , the focusing lens 22 , and the sample focusing lens 26 functionalities are all done with a single lens. In addition, the optional collection lens 30 shown in the previous embodiments is omitted to even further simplify the construction. A spectrometer similar to that in FIG. 3 has been constructed and demonstrated with the optics portion consuming a volume of less than 2 cubic inches. Another advantage of this design over previous designs is that it is difficult to refocus light leaving the DMD to a single point without the use of a second pass off a grating. Such a second pass grating is possible but much more complicated and is inefficient. In previously disclosed designs the collected light from the DMD cannot be well focused onto a detector and therefore use defocused light at the detector which in turn leads to low efficiency. The advantage of this disclosure is that it places the sample at the point of defocus which is ideal for illuminating a large sample area. This effectively combines two points of efficiently loss, the poorly focused light from the DMD and the diffuse nature of the sample, into only one. This makes the overall design more efficient than prior art. Controller 50 , FIG. 1 may control source 12 in addition to DMD 24 and/or may process signals from detector 32 to provide an output to the user regarding the elemental and molecular composition of sample 28 . Controller 50 can be programmed to direct specific wavelengths to the sample sequentially (e.g., 500 nm, then 600 nm, then 700 nm, and so on) with the detector output processed between wavelengths. Also, groups of wavelengths can be directed to the sample sequentially. In another example, 500 nm wavelength light is directed to the sample by activating one or more mirrors (e.g., a block or section with 100 mirrors in a 10×10 array) dedicated to the 500 nm wavelength. Other wavelengths are directed elsewhere. The detector output is then processed. Similar measurements are made and processed at each of the other wavelengths. Then, no wavelengths from the source 12 are directed to the sample and the detector output is processed to determine the back ground signal which includes ambient light, sensor dark current, and any internal stray light within the spectrometer. This background signal is subtracted from each of the individual wavelength readings yielding a spectrum uninfluenced by ambient light, detector dark current, and stray light. For an even more extended wavelength range it is also possible to use more than one detector since several detectors can be mounted next to each other in the configuration described herein. If multiple detectors are used, a separate collection lens may optionally be used with each detector. The foregoing description and drawings comprise illustrative embodiments of the present invention. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art that have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the inventions Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”. “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended. Other embodiments will occur to those skilled in the art and are within the following claims.

Featured is a spectral analysis method and a wide spectral range spectrometer including a source of electromagnetic radiation and an optical subsystem configured to disperse radiation into a plurality of wavelengths. A pixilated light modulator receives the radiation wavelengths and is configured to direct one or more selective wavelengths to a sample.

This is a continuation of application, Ser. No. 512,233 filed July 11, 1983, now abandoned. REFERENCE TO RELATED PATENT APPLICATIONS Reference is made to the previous Roy R. Vann Patents, U.S. Pat. Nos. 3,871,448; 3,931,855; 4,040,485; and 4,151,880 for further background of this invention, and to the references cited therein. BACKGROUND OF THE INVENTION There are many instances when it is desirable to run a tool string downhole into a borehole with a lower end portion of the tubing string being opened to the flow of well fluids from the borehole so that no differential in hydrostatic head is developed. In a producing well, it may be desirable to reperforate the existing producing formation or to perforate another production zone within the well. In such a situation, a hydrostatic head of drilling mud is used to maintain a bottomhole pressure that is greater than the formation pressure to insure that the well is under control at all times and thereby prevent any blowout. If a sufficient hydrostatic head were not established, the well could start "kicking" during the new perforating. The general tubing conveyed perforation technique includes a tubing string with a closed vent assembly and perforating gun. The tubing string is run into the well substantially dry with only a small amount of fluid in the bottom of the string to cushion the impact of a bar dropped through the string to detonate the perforating gun. Thus, the vent assembly in the tool string is run into the well in the closed position. However, where it is necessary to maintain the hydrostatic head as in a producing well, the lowering of a dry tubing string into the well would reduce the hydrostatic head so as to possibly cause the loss of control over the well. Thus, it is desirable to run the tubing string into the well "wet" with a vent assembly open whereby well fluids can run into the tubing string to maintain the hydrostatic head. Further, if the well should start "kicking", the open vent assembly permits circulation down through the tubing and into the well to provide further means to kill the well at any time. For example, often in a dual formation well where the production fluid from the two formations can be co-mingled, the lower zone is perforated and tested and then gently killed with calcium chloride and water such that the completion will not be damaged. If one were to go back into the well with dry tubing, there would be no means to maintain the hydrostatic head or to circulate through the tubing string such that the lower formation would start producing before the dry tubing string reached the location of the upper formations to be perforated. This would occur due to the reduction of the hydrostatic head to a value lower than the formation pressure causing the lower formation to start producing. The present invention provides a means whereby a perforating gun can be run downhole on the end of a tubing string along with a packer actuated vent assembly held in the open position and which can be subsequently moved to the closed position upon the setting of the packer. Additionally, there is another vent assembly included in the tool string below the packer which can be moved from the closed position to the open position at any subsequent time such as just prior to the detonation of the perforating gun. This unique combination enables an extremely large casing type perforating gun to be run downhole with the tubing string open to the flow of well fluids whereby there is a zero back pressure on the tubing string. After the tool string has been positioned downhole in the borehole, the interior of the tool string can be isolated from the fluids contained within the casing annulus by closing the packer actuated vent assembly. Once the gun is suspended downhole adjacent to the production formation, the second vent assembly is moved into the open position and the gun is detonated at some subsequent time. Further, once the packer is in position and can be set, the present invention provides the option of lowering the hydrostatic head in the tubing string by displacing the well fluids in the tubing string with another fluid such as nitrogen. As the nitrogen is pumped down the tubing string, the well fluid in the tubing string are displaced through the open packer actuated vent assembly of the present invention. Once the desired hydrostatic head is reached, as for example to obtain an underbalance, the packer actuated vent may be closed and the nitrogen bled off to obtain the desired hydrostatic head in the tubing string to provide the desired pressure differential for backsurging. The underbalance or pressure differential can also be achieved by swabbing the tubing string dry after the packer actuated vent assembly has been closed. In the prior art, sliding sleeves actuated by wireline have been used to permit flow into the tubing string. Such a sliding sleeve is manufactured by Baker Oil Tools. However, such sliding sleeves are not dependable and do not always seal. Further, the wireline can be blown out of the hole and become tangled. Also, it is cheaper to use a vent assembly in the tool string which can be actuated by the setting of the packer than use a wireline operated sleeve. SUMMARY OF THE INVENTION The present invention comprehends both method and apparatus for completing boreholes. According to the method of the present invention, a packer device is connected to a tubing string and an open vent assembly is associated with the packer device. The normally open vent assembly is moved to the closed position when the packer device is set downhole in the borehole. A second vent assembly, normally in the closed position, is connected between a perforating gun and the packer-actuated vent assembly. The entire tool string is run downhole with the first vent assembly being in the open position. When the packer is set, the upper vent assembly is moved to the closed position, thereby isolating the interior of the tool string from the borehole annulus. At some subsequent time, the lower vent assembly is moved to the open position and the gun fired when it is desired to complete the well. The method of the present invention is carried out by the provision of a packer actuated vent assembly having an outer barrel connected to the outer barrel of the packer, and a mandrel extension connected to the lower end of the mandrel of the packer device. A sliding valve element sealingly engages a radial port formed in the mandrel, and when the packer is set, the sliding valve element is moved from the open to the closed position relative to the port, thereby producing flow therethrough. Therefore, when running into the borehole, flow can occur from the casing annulus, into the outer barrel, through the open port, up through the packer mandrel, up through the upper tubing, and to the surface of the ground, and thereafter, the tubing interior is isolated from well fluids. Accordingly, a primary object of the present invention is the provision of a packer actuated vent assembly which is moved from the normally open to the closed position when the packer is set downhole in a borehole. Another object of this invention is the provision of a packer actuated vent assembly having a slidable valve element associated therewith and which is closed in response to the setting of a packer. A further object of this invention is to provide a method of completing a borehole, wherein a packer actuated valve assembly equalizes the pressure between the casing annulus and tubing interior before the packer is set, and thereafter the interior of the tubing string is maintained isolated from the annulus. A still further object of this invention is the provision of a vent assembly which is actuated to the closed position in response to the setting of a retrievable packer. Another and still further object of this invention is the provision of both method and apparatus by which a vent assembly is moved to the closed position by utilizing the movement of the tubing string required in setting a retrievable packer. Another object of the present invention is the provision of an open-to-closed packer actuated vent assembly permitting circulation through the tubing string as it is lowered into the well. These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by reference to the accompanying drawings. The above objects are attained in accordance with the present invention by the provision of a method of completing a well for use with apparatus fabricated in a manner substantially as described in the above abstract and summary. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical, part cross-sectional, broken view of a borehole formed into the surface of the earth; FIG. 2 is an enlarged, broken, side elevational view of part of the apparatus disclosed in FIG. 1; FIG. 3 is an enlarged, longitudinal, cross-sectional view of part of the apparatus disclosed in FIG. 2; FIGS. 4 and 5 are cross-sectional views taken along lines 4-4 and 5-5 of FIG. 3; and FIG. 6 is a fragmentary, part cross-sectional view which discloses part of the apparatus shown in FIG. 3, with some parts thereof being moved to an alternate position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 discloses a well head 8 connected to the illustrated borehole 10. Within the borehole there is disclosed a retrievable packer 12 connected to a packer actuated vent assembly 14 made in accordance with the present invention. The packer 12 can take on any number of different forms so long as it is provided with a hollow mandrel for conducting flow of fluid axially therethrough, and so long as the mandrel is reciprocated relative to the packer body while the packer is being set. As for example, a Baker Lok-Set retrievable casing packer, product No. 642-12 page 498, Baker Oil Tool 1970-71 catalog, Baker Oil Tools, Los Angeles, California. Other packer apparatus which can be used with the present invention are exemplified by the patent to Brown, U.S. Pat. No. 2,893,492, or Keithahn, U.S. Pat. No. 3,112,795. As illustrated in FIG. 1, in conjunction with some of the remaining figures of the drawings, packer 12 includes a packer body 20, hollow mandrel 88, packer rubbers 22, upper and lower slips 24, 26 and drag blocks 28. Interface 16 on the lower end of body 20 defines a shoulder of a threaded connection effected by the lower threaded marginal terminal end of the packer body 20 and the upper threaded marginal terminal end of the vent assembly 14. Sub 17 above packer 12 is attached to coupling member 18 of the mandrel 88 of the packer 12 so that the packer 12 can be series connected and supported by the illustrated tubing string 9. The lower edge portion 19 of the mandrel coupling 18 is movable towards the upper portion of body 20 of the packer 12 until the lower edge portion 19 abuts upper edge portion 21 of packer body 20, thereby causing the packer rubbers 22 to be set within the casing 7. Radially disposed slips 24 and 26 of packer 12 are forced in an outward direction by movement of the mandrel 88 so as to anchor the packer 12 to the interior surface of the wall of casing 7. Drag blocks 28 on packer 12 frictionally engage casing 7 to prevent movement of the packer body 20 relative to the casing 7 while packer mandrel 88 is being manipulated. The vent assembly 14 of the present invention comprises a cylindrical barrel 30 having spaced radial ports 32 located intermediate the downwardly opening peripheral edge portion 34 of barrel 30 and the lower end 16 of body 20 of packer 12; and, a mandrel extension 36 having a lower marginal end threadingly engaging a sub or coupling 37 for connection of the vent assembly 14 into a pipe string 38 so that a perforating or jet gun 42 or the like can be run downhole into the borehole 10 and positioned adjacent to a hydrocarbon containing formation 43 shown in FIG. 2 (when it is desired to complete the well). FIGS. 3 and 6 disclose some additional details of the before mentioned packer actuated vent assembly 14 of the present invention. As seen in FIG. 3, together with FIGS. 4-6, upper edge portion 31 of the outer barrel 30 of the vent assembly 14 is threadingly engaged with the lower end of the packer body 20 of the retrievable packer 12. The packer often includes a J-latch 46, as is known to those skilled in the art. J-latch 46 is used to hook on and set packer 12. An axial passageway 48 extends centrally through the outer barrel 30. The mandrel extension 36 is concentrically arranged with respect to the outer barrel 30 and forms an annular area 52 therebetween. Ports 54 are formed within the sidewall of the mandrel extention 36 and provide a flow path along which fluid can flow from the annulus 52 into the interior of the mandrel extension 36 and vice versa. O-rings 56 and 58 are spaced from one another along alternate sides of ports 54 and are housed in grooves which circumferentially extend about the mandrel extension 36. A slidable valve element 60 has an inside surface area made in close tolerance slidable relationship with respect to the outer circumferentially extending sealing surface 62 of the mandrel extension 36. As best seen illustrated in FIG. 6, the sealing surface 62 preferably is formed along a medial portion of the exterior of the mandrel extension 36 so as to provide ample room for a seal between extension 36 and valve element 60, and at the same time reduce friction to a minimum by the provision of an undercut area at 64 around the medial portion of mandrel extension 36. The lower end 66 of the valve element 60 is abuttingly received against the illustrated circumferentially extending shoulder 61 of extension 36. A boss 68 is formed at the upper end of the valve element 60 for reasons hereinafter described. As seen in FIGS. 3, 5, and 6, a protective sleeve 70 is provided with an inside diameter 72 which is greater than the outside diameter of valve element 60, and therefore forms an upwardly opening cavity within which the beforementioned valve element 60 is slidably received. The outer protective sleeve 70 serves to guard, shield, and protect valve element 60 thereby preventing material from accidentally hanging on valve element 60 before one is ready for boss 68 to engage internal shoulder 76 to close the vent assembly 14. Sleeve 70 also protects against debris fouling valve element 60. Fastener means 74 maintains the protective sleeve 70 in fixed relationship with respect to the mandrel extension 36. Lower cylindrical shoulder 76 is rigidly affixed to the inside surface of the lower terminal end of the outer barrel 30. The inside diameter of the shoulder 76 is slightly spaced at 78 from the outer peripheral wall of the mandrel extension 36. The face of the shoulder 76 abuttingly engages face 80 of the boss 68 in order to move the valve element 60 into the closed position. Lower radial port 32 forms a flow passageway for well fluid to flow into annulus 52, whereupon the fluid can proceed up the annulus 52 and into open ports 54, when ports 54 are in the open position. As seen in FIG. 2, together with FIGS. 3 and 6, the lower threaded end 84 of the mandrel extension 36 connects sub or coupling 37 to the pipe string 38, as may be required in order to assemble additional tools downhole of the packer actuated vent assembly 14. Upper threaded surface 86 of the mandrel extension 36 is connected to the lower threaded end of the mandrel 88 of the retrievable packer 12. Mandrel 88 presents a lower shoulder 90 which abuttingly engages shoulder 92 of boss 68 of the valve element 60, in the event the element 60 should be moved to its extreme upward limit of travel, whereupon, lower end 66 of the valve element 60 continues to cover both the O-rings 56 and 58. The dot-dash numeral at 94 indicates an auxiliary port formed within the outer barrel 30, if desired. Port 94 has the same purpose as ports 32 in the lower part of the barrel 30, i.e. to provide additional flow area into tubing string 9. As particularly seen in FIG. 2, a second vent assembly 39 is connected in underlying relationship with respect to the packer actuated vent assembly 14 and is further included in the tool string above jet perforating casing gun 42 such as that described in U.S. Pat. Nos. 3,706,344 or 4,140,188. Vent assembly 39 may include and incorporate any number of vent assemblies such as shown in U.S. Pat. No. 4,151,880, U.S. Pat. No. 4,299,287, and U.S. Patent application Ser. No. 166,547 filed July 7, 1980. The bar actuated vent assembly disclosed in U.S. Pat. No. 4,299,287 is preferred. A second vent assembly is required so that tubing string 9 may be opened to the flow of production fluid prior to the detonation of the perforating gun. Thus, the tool string set forth in the embodiment of the invention illustrated in FIG. 2 includes two vent assemblies; that is, the packer actuated vent assembly 14, which is run into the well open, and another vent assembly 39, which is run into the well closed. Vent assembly 14 is closed during the setting of packer 22; therefore, prior to perforation, the closed vent assembly 39 is opened for accomodating any subsequent flow of production fluids from formation 43. The present invention is not restricted to any specific type of vent assembly 39. The vent assembly 39 can be pressure operated, mechanically operated, or slick line operated. Further, a pop-out vent assembly such as that shown and described in U.S. Patent application Ser. No. 384,508 filed 6/3/82 entitled "Gun Below Packer Completion Tool String", can be used as vent assembly 39. Such a pop-out vent assembly includes a vertical frangible disc mounted in the tubing string whereby the pop-out vent assembly collapses upon a predetermined pressure differential being achieved across the tubing string. For example, as the pressure differential across the tubing string reaches 300 psi, the frangible disc collapses and opens the tubing string to production flow. The pop-out vent can also be actuated by circulating nitrogen down the tubing string, setting the packer, and bleeding off the nitrogen pressure until the desired underbalance is achieved at which time the pop-out vent collapses, opens the tubing string to flow, backsurges the perforations upon perforating, and permits the production fluids to flow into the tubing and up to the surface. Also, the desired differential pressure to open the pop-out vent can be achieved by swabbing the tubing string. In carrying out the method of the present invention, the tool string illustrated in FIGS. 1 and 2 is assembled in the usual manner. The remaining components of the pipe string 38 are connected at threaded surface 84 for lowering the tool string downhole into the borehole 10. At this time, ports 54 of the packer actuated vent assembly 14 are in the illustrated open position of FIG. 3. Accordingly, as vent assembly 14 passes below the level of well fluids in the borehole 10, well fluids are free to flow into tubing string 9 thereby creating a hydrostatic head. Thus, the hydrostatic head within tubing string 9 and well annulus 52 are maintained equal to one another since the well fluids are free to flow between the tubing interior and the annulus 52. By maintaining a substantially constant hydrostatic head in borehole 10, the producing well remains killed since the hydrostatic head remains greater than the formation pressure. Further, if the well starts "kicking", well fluid may be circulated down the tubing string and through vent assembly 14 to kill the well at any time. Further, it may be desirable to circulate through vent assembly 14 as the string is lowered into the well where well fluids have been permitted to settle and possibly compact within the cased borehole 10. Prior to setting the packer, it may be desirable to create a predetermined underbalance on the formation. This may be accomplished by pumping fluid, such as diesel or light production, down the tubing string to displace the well fluids in the tubing string through the vent assembly. The hydrostatic head in the tubing string can also be controlled by displacing the fluid in the tubing string with nitrogen whereby after vent assembly 14 is closed, the nitrogen can be bled out of the tubing string 9 to obtain the desired hydrostatic head for achieving the desired pressure differential for backsurging. Another method includes closing vent assembly 14 and swabbing it dry to reduce the hydrostatic head to achieve the desired unbalance. In summary, the desired underbalance can be obtained by replacing the well fluids in the tubing string with a lighter fluid and closing vent assembly 14 or by first closing vent assembly 14 and swabbing tubing string 9 substantially dry. After packer 12 arrives at a location which positions perforating gun 42 adjacent to the formation 43 and the hydrostatic head in tubing string 9 is reduced to achieve the desired underbalance, packer 12 is set by manipulating upper tubing string 9 which in turn manipulates packer mandrel 88 setting packer 12 and slips 24, 26. Once the seals 22 of packer 12 are set, it is now safe to perforate the old formation or to perforate a new formation. As the packer mandrel 88 is manipulated, either by turning or by directly setting down, the packer mandrel 88 moves downhole relative to the packer body 20, carrying the packer mandrel 88 therewith until face 80 of boss 68 abuttingly engages the face of shoulder 76. As the mandrel extension 36 continues to move downhole, the valve element 60 is moved from the illustrated position of FIG. 3 into the dot-dash position 68', which is also the position seen illustrated in FIG. 6. This action moves the valve element 60 into closed relationship relative to ports 54 so that well fluids cannot flow from the interior of the tubing string 9 outward or inward from the annulus 52. Depending upon the well environment, the desired pressure differential may be achieved at this time by bleeding off nitrogen in the tubing string or by swabbing fluid out of the tubing string to obtain a predetermined hydrostatic head in the tubing string. A suitable bar is dropped down through the tubing string 9 and travels through the upper tubing string, through the retrievable packer mandrel 88, through the mandrel extension 36 of the vent assembly 14, and through the second vent assembly 39, whereupon the bar engages and moves the valve element of vent assembly 39 to cause the port 40 to assume the open position. The bar continues to travel downhole and is arrested by the gun firing head of the perforating gun 42, whereupon the shaped charges thereof are detonated, and the casing 7 perforated. This forms a flow path along which hydrocarbons from formation 43 can then flow through the perforations, into the lower casing annulus, uphole into port 40 of the vent assembly 39, uphole through the packer actuated vent assembly 14, through the packer 12, and uphole through the tubing string 9 to top of the ground where the production is gathered in the usual manner. While a preferred embodiment of the invention has been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit of the invention.

A packer actuated vent assembly comprising an outer barrel attached to a packer body, and a mandrel extension attached to the lower end of the mandrel of the packer. A valve means on the mandrel extension has a slidable valve element which slidably engages a medial portion of the outer peripheral surface of the mandrel and normally is in the opened position. The valve element has a boss thereon which engages a shoulder on the barrel and is thereby moved from the opened to the closed position when the packer mandrel, and therefore the mandrel extension, is properly manipulated to seat the packer. This combination of elements enables a tubing string to be run downhole into a borehole with the tubing string in the open configuration, so that fluid contained within the annulus flows through the opened valve means into the tubing string, thereby balancing the fluid pressure on either side of the tubing string; and when the packer is set, the interior of the tubing string is isolated from the borehole annulus.

BACKGROUND [0001] Severe back pain and nerve damage may be caused by injured, degraded, or diseased spinal joints and particularly, spinal discs. Current methods of treating these damaged spinal discs may include vertebral fusion, nucleus replacements, or motion preservation disc prostheses. Disc deterioration and other spinal deterioration may cause spinal stenosis, a narrowing of the spinal canal and/or the intervertebral foramen, that causes pinching of the spinal cord and associated nerves. Current methods of treating spinal stenosis include laminectomy or facet resection. Alternative and potentially less invasive options are needed to provide spinal pain relief. SUMMARY [0002] In one embodiment of the present disclosure, an inter-transverse process spacer system comprises a first spacer device. The first spacer device comprises opposing end portions. The first spacer device is adapted for insertion between a first pair of adjacent transverse processes, and the opposing end portions of the first spacer device are adapted to engage the first pair of adjacent transverse processes. The inter-transverse process spacer system further comprises a first connection device connected to the first spacer device and adapted to engage at least one of the first pair of adjacent transverse processes. [0003] In another embodiment, an inter-laminar spacer system comprises a first connection device adapted to engage a lamina of a first vertebra and a second connection device adapted to engage a lamina of a second vertebra. The inter-laminar spacer system further comprises a first lamina spacer extending between the first and second connection devices. [0004] In another embodiment, a method of spinal decompression comprises accessing a pair of transverse processes and inserting a spacer device between the pair of transverse processes. The method further comprises engaging a connection device with the spacer device and at least one of the pair of transverse processes. [0005] In another embodiment of the present disclosure, a method of decompressing a spinal joint comprises accessing an interlaminar space between first and second lamina and inserting a spacer system into the interlaminar space. The method further comprises connecting the spacer system to inner and outer faces of the first lamina. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a perspective view of a vertebral column with an inter-transverse process spacer system according to one embodiment of the present disclosure. [0007] FIG. 2 is an assembled perspective view of the spacer system of FIG. 1 . [0008] FIG. 3 is a perspective view of a component of the spacer system of FIG. 1 . [0009] FIG. 4 is a sectional view of the component of FIG. 3 . [0010] FIG. 5 is a perspective view of a vertebral column with an inter-laminar spacer system according to one embodiment of the present disclosure. [0011] FIG. 6 is an assembled perspective view of the spacer system of FIG. 5 . DETAILED DESCRIPTION [0012] The present disclosure relates generally to the field of orthopedic surgery, and more particularly to systems and methods for decompressing a spinal joint. For the purposes of promoting an understanding of the principles of the invention, reference will now be made to embodiments or examples illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alteration and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates. [0013] Referring first to FIG. 1 , the numeral 10 refers to a vertebral joint which includes an intervertebral disc 12 extending between vertebrae 14 , 16 . The vertebra 14 includes a lamina 18 , and the vertebra 16 includes a lamina 20 . The vertebrae 14 , 16 also include vertebral bodies 14 a , 16 a , respectively. The vertebra 14 further includes transverse processes 22 , 24 ; a spinous process 26 ; and caudal articular processes 28 , 30 . The vertebra 16 further includes transverse processes 32 , 34 ; a spinous process 36 ; and rostral articular processes 38 , 40 . Although the illustration of FIG. 1 generally depicts the vertebral joint 10 as a lumbar vertebral joint, it is understood that the devices, systems, and methods of this disclosure may also be applied to all regions of the vertebral column, including the cervical and thoracic regions. Furthermore, the devices, systems, and methods of this disclosure may be used in non-spinal orthopedic applications. [0014] A facet joint 42 is formed, in part, by the adjacent articular processes 28 , 38 . A facet joint 44 is formed, in part, by the adjacent articular processes 30 , 40 . Facet joints may also be termed zygapophyseal joints. A healthy facet joint includes a facet capsule extending between the adjacent articular processes. The facet capsule comprises cartilage and synovial fluid to permit the articulating surfaces of the articular processes to remain lubricated and glide over one another. The type of motion permitted by the facet joints is dependent on the region of the vertebral column. For example, in a healthy lumbar region, the facet joints limit rotational motion but permit greater freedom for flexion, extension, and lateral bending motions. By contrast, in a healthy cervical region of the vertebral column, the facet joints permit rotational motion as well as flexion, extension, and lateral bending motions. As the facet joint deteriorates, the facet capsule may become compressed and worn, losing its ability to provide a smooth, lubricated interface between the articular surfaces of the articular processes. This may cause pain and limit motion at the affected joint. Facet joint deterioration may also cause inflammation and enlargement of the facet joint which may, in turn, contribute to spinal stenosis. Removal of an afflicted articular process may result in abnormal motions and loading on the remaining components of the joint. The embodiments described below may be used to decompress a deteriorated facet joint and/or restore more natural motion constraint to a resected joint. [0015] Injury, disease, and deterioration of the intervertebral disc 12 may also cause pain and limit motion. In a healthy intervertebral joint, the intervertebral disc permits rotation, lateral bending, flexion, and extension motions. An axis of flexion 46 may extend between the vertebral bodies 14 a , 16 a and through the intervertebral disc 12 . As the intervertebral joint deteriorates, the intervertebral disc may become compressed, displaced, or herniated, resulting in excess pressure in other areas of the spine, particularly the posterior bony elements of the afflicted vertebrae. This deterioration may lead to spinal stenosis. The embodiments described below may restore more natural spacing to the posterior bony elements of the vertebrae, decompress an intervertebral disc, and/or may relieve spinal stenosis. [0016] Referring still to FIG. 1 , in one embodiment, a spacer system 50 may be used to support the transverse processes 24 , 34 ; decompress the disc 12 and the facet joint 44 ; and/or relieve stenosis. The spacer system 50 includes a spacer device 52 which may be monolithically formed of an elastic, multi-directionally flexible material such as silicone, polyurethane, or hydrogel. The spacer device 52 may include two pairs of legs 54 , 56 integrally formed with and extending from a cross member 58 . As shown in greater detail in FIGS. 3 and 4 , the cross member 58 may comprise transverse conduits 60 , 62 . The openings of the conduits 60 , 62 may be widened and curved to minimize sharp edges that could present a point of wear. The internal faces of the legs 54 are angled to converge toward a recessed area 66 , and the internal faces of the legs 56 are angled to converge toward a recessed area 68 . The cross member 58 has a thickness 64 which may be slightly greater than the inter-transverse process space between the processes 24 , 34 when the vertebra 14 , 16 are in a natural position. For example, the cervical and lumbar regions of the vertebral column may be in lordosis when in a natural position. [0017] Referring now to FIGS. 1 and 2 , in this embodiment, the spacer system 50 further includes connection devices such as cables 70 , 72 which extend through the transverse conduits 62 , 64 , respectively, of the cross member 58 . At least one end of each of the cables 70 , 72 may be attached to stopper devices 74 , 76 , respectively. The connection devices may be either elastic or inelastic and able to carry tensile forces. They may be formed, for example, of biocompatible reinforcing materials such as wire, cable, cord, bands, tape, or sheets. They may have a braided, knitted, or woven construction. [0018] A surgical procedure to implant the spacer system 50 may be ultra minimally invasive. Using a posterior, posterolateral, lateral, anterolateral or anterior approach, a small incision may be created in the patient's skin. The transverse processes 24 , 34 may be visualized directly or with radiographic assistance. The spacer device 52 may be compressed and inserted between the transverse processes 24 , 34 . The spacer device 52 may then expand slightly so that the recess 68 comes into firm contact with the transverse process 24 and the recess 66 comes into firm contact with the transverse process 34 . The cross member 58 may remain slightly compressed after implantation so that the recesses 66 , 68 may continue to exert pressure on the transverse processes 34 , 24 , respectively, minimizing the opportunity for the spacer device 52 to be come dislodged. The compression of the cross member 58 may bias the legs 56 to compress together, creating a firm grip on the transverse process 24 . This holding action, together with the flexibility of the device 52 , minimizes friction and the associated material and bone wear. The legs 54 may, likewise, grip transverse process 34 . [0019] The connection device 72 , led for example by a needle, may be inserted through the conduit 60 and around the transverse process 24 . The connection device 72 may then be inserted through the stopper 76 . The location of the spacer device 52 may still be adjusted while the connection device 72 is relatively loose. For example, the spacer device 52 may be placed close to the base of the transverse processes 24 , 34 , near the vertebral bodies 14 a , 16 a , to reduce the torsional forces placed on the spacer device by the transverse processes. With the spacer device 52 in the desired position, the connection device 72 may be tightened, and anchored to the stopper device 76 . The stopper device 76 may thus anchor both ends of the connection device 72 . The connection device 70 may similarly anchor the spacer device to the transverse process 34 . [0020] In certain anatomies, the spacer system 50 may be used alone to provide decompression to a single targeted facet joint or to relieve pressure on a particular side of the intervertebral disc, such as a herniation area. But, as shown in FIG. 2 , a second spacer system 80 may be installed on the opposite lateral side from the spacer system 50 , between transverse processes 22 , 32 . The spacer system 80 , when used in conjunction with the spacer system 50 , may provide more balanced support and equalized decompression. The spacer system 80 may be substantially similar to system 50 and therefore will not be described in detail. [0021] The spacer system 50 , as installed, may axially separate the vertebrae 14 , 16 , relieving pressure on the intervertebral disc 12 and the facet joint 44 and reducing wear and further degeneration. The spacer device 52 may also dampen the forces on the intervertebral disc 12 and facet joint 44 during motion such as flexion and extension. Because the spacer device 52 may be positioned relatively close to the natural axis of flexion 46 , the spacer system 50 may be less likely to induce kyphosis as compared to systems that rely upon inter-spinous process devices to provide decompression. Additionally, the system 50 may be installed minimally invasively with less dissection than the inter-spinous process devices of the prior art. Furthermore, an inter-transverse process system can be used on each lateral side of the vertebrae 14 , 16 , and may provide greater and more balanced decompression than the single inter-spinous process devices of the prior art. [0022] In an alternative embodiment, the conduits through the spacer device may be omitted and the connection devices attached to other connection points on the spacer device such as side handles. The connection device may extend through or into one or both of the transverse processes. In still another alternative, the connection device may be eliminated and the spacer device held in place by the compressive forces of the transverse processes. The connection device may also take the form of a clamp, spike, threaded connection or any other type of mechanical or adhesive connection for attaching devices to bone. [0023] In another alternative embodiment, the spacer device may be shaped to address various patient anatomies and afflictions. In one embodiment, the legs of the spacer device may be angled such that the spacer device provides not only cephalad-caudal axial decompression but also anterior or posterior decompression. For example, in a patient recovering from disc surgery, the spacer device may be angled toward lordosis to take pressure off the intervertebral disc temporarily. Likewise the spacer device may be angled toward kyphosis to temporarily reduce pressure on a recovering facet joint. [0024] In another alternative embodiment, the material of the spacer device may be completely or partially rigid. A sheath may be also surround the spacer device to limit direct contact between the spacer device and the surrounding tissue. The sheath may also serve to contain wear debris and limit over stretching of the spacer device. [0025] Referring now to FIGS. 5 and 6 , in one embodiment, a spacer system 100 may be used to support the laminae 18 , 20 ; decompress the disc 12 and the facet joint 44 ; and/or relieve stenosis. The spacer system 100 includes a spacer device 102 which may be monolithically formed of an elastic, multi-directionally flexible material such as silicone, polyurethane, or hydrogel. The spacer device 102 may have a wider midsection and may taper slightly toward the ends. The spacer device may have a height 108 which may be slightly greater than the inter-laminar space between the processes 18 , 20 when the vertebra 14 , 16 are in a natural position. For example, the cervical and lumbar regions of the vertebral column may be in lordosis when in a natural position. [0026] The spacer system 100 further includes connection devices 104 , 106 such as laminar hooks which are attached to the opposite ends of the spacer device 102 . The laminar hook 104 may comprise an outer arm 110 and an inner arm 112 . The laminar hooks 104 , 106 may be formed of any suitable biocompatible material including metals such as cobalt-chromium alloys, titanium alloys, nickel titanium alloys, and/or stainless steel alloys. Ceramic materials such as aluminum oxide or alumnia, zirconium oxide or zirconia, compact of particulate diamond, and/or pyrolytic carbon may be suitable. Polymer materials may also be used, including any member of the polyaryletherketone (PAEK) family such as polyetheretherketone (PEEK), carbon-reinforced PEEK, or polyetherketoneketone (PEKK); polysulfone; polyetherimide; polyimide; ultra-high molecular weight polyethylene (UHMWPE); and/or cross-linked UHMWPE. [0027] A surgical procedure to implant the spacer system 100 may be relatively minimally invasive. Using a posterior, posterolateral, lateral, or other suitable approach, a small incision may be created in the patient's skin. The ligamentum flavum or other soft tissues may be mobilized and the laminae 18 , 20 may be visualized directly or with radiographic assistance. The spacer device 102 may be compressed and the laminar hooks 104 , 106 may be inserted between the laminae 18 , 20 . The spacer device 102 may then expand slightly so that hooks 104 , 106 come into firm contact with the laminae 20 , 18 , respectively. The spacer device 102 may remain slightly compressed after implantation so that the hooks 104 , 106 may continue to exert pressure on the laminae 20 , 18 , respectively, minimizing the opportunity for the spacer device 102 to be come dislodged. With the system 100 installed, the arms 110 , 112 of the hook 104 may firmly contact the outer and inner faces, respectively, of the lamina 20 . The hook 106 may similarly engage the lamina 18 . [0028] In certain anatomies, the spacer system 100 may be used alone to provide decompression to a single targeted facet joint or to relieve pressure on a particular side of the intervertebral disc, such as a herniation area. However, a second spacer system may also be installed on the opposite lateral side from the spacer system 100 . The spacer system 100 , when used in conjunction with a second spacer system, may provide more balanced support and equalized decompression. [0029] The spacer system 100 , as installed, may axially separate the vertebrae 14 , 16 , relieving pressure on the intervertebral disc 12 and the facet joint 44 and reducing wear and further degeneration. The spacer device 102 may also dampen the forces on the intervertebral disc 12 and facet joint 44 during motions such as flexion and extension. Because the spacer device 102 may be positioned relatively close to the natural axis of flexion 46 , the spacer system 100 may be less likely to induce kyphosis as compared to systems that rely upon inter-spinous process devices to provide decompression. Additionally, the system 100 may installed with less dissection than the inter-spinous process devices of the prior art. Furthermore, an inter-laminar system can be used on each lateral side of the vertebrae 14 , 16 , and may provide greater and more balanced decompression than the single inter-spinous process devices of the prior art. [0030] In an alternative embodiment, the laminar hooks may have a spring action which draws the arms together to engage the lamina, or the hooks may have a vise mechanism which draws the arms together to engage the lamina. This holding action, together with the flexibility of the device 102 , may minimize friction and the associated material and bone wear. [0031] In still another alternative, the spacer device may be formed of a rigid material such as those listed above for the laminar hooks. A rigid spacer device may be height adjustable such that a decreased height may be set to provide easy access for the laminar hooks, and an increased height may be set to bring the hooks into firm contact with the laminar walls. [0032] In still another alternative embodiment, the connection devices may attach to other posterior bones such as the adjacent articular or spinous process. A connection device such as the cabling system 72 described above may also be used to connect the spacer device between the laminae. For example, a cable could extend around the lamina, through the spinal foramen to tether the spacer device to the lamina. [0033] Although only a few exemplary embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this disclosure. Accordingly, all such modifications and alternative are intended to be included within the scope of the invention as defined in the following claims. Those skilled in the art should also realize that such modifications and equivalent constructions or methods do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. It is understood that all spatial references, such as “horizontal,” “vertical,” “top,” “upper,” “lower,” “bottom,” “left,” “right,” “cephalad,” “caudal,” “upper,” and “lower,” are for illustrative purposes only and can be varied within the scope of the disclosure. In the claims, means-plus-function clauses are intended to cover the elements described herein as performing the recited function and not only structural equivalents, but also equivalent elements.

An inter-transverse process spacer system comprises a first spacer device. The first spacer device comprises opposing end portions. The first spacer device is adapted for insertion between a first pair of adjacent transverse processes, and the opposing end portions of the first spacer device are adapted to engage the first pair of adjacent transverse processes. The inter-transverse process spacer system further comprises a first connection device connected to the first spacer device and adapted to engage at least one of the first pair of adjacent transverse processes.

CROSS REFERENCES TO RELATED APPLICATIONS [0001] This application contains subject matter related to Japanese Patent Application JP2011-078550 filed in the Japanese Patent Office on Mar. 31, 2011, the entire content of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to an optical coherence tomographic image forming apparatus and a control method thereof. BACKGROUND DISCUSSION [0003] Medical care is performed inside a blood vessel depending on a highly functional catheter such as a balloon catheter, a stent and the like. For this medical care, it has been becoming popular to use an imaging apparatus for diagnosis such as an optical coherence tomography (OCT) apparatus and the like for a diagnosis before operation or a follow-up confirmation after operation. [0004] This imaging apparatus for diagnosis includes an optical lens at the distal end and further, includes a catheter installed with an optical fiber attached with an optical mirror. Then, a radial scan is carried out by inserting the catheter thereof inside a blood vessel of a patient, by illuminating light onto the blood vessel wall through the optical mirror while rotating the optical mirror and by light-receiving the reflected light again from a biological tissue through the optical mirror thereof, and a cross-sectional image of the blood vessel is to be constructed based on the obtained reflected light. Also, for an improved type OCT apparatus, there has been developed an optical frequency domain imaging (OFDI) apparatus. [0005] The basic principle of the optical coherence tomographic diagnostic apparatus lies in that the light outputted from a light source inside the apparatus is divided into a measurement light and a reference light, and the measurement light is emanated through the optical mirror of the abovementioned optical fiber. Then, a scattering light reflected by the biological tissue is light-received through the same optical fiber, there is obtained an interference light with respect to the reference light which is reflected by going through a known distance, a tomographic image of the biological tissue (blood vessel) in the vicinity of the catheter is to be obtained from the intensity thereof. An example is disclosed in Japanese unexamined patent publication No. 2007-267867. [0006] In particular, in case of the optical frequency domain imaging apparatus, it is possible, by sweeping the emanated optical wavelength repeatedly within a predetermined range, to obtain reflection-intensity distribution in the depth direction, in which the measurement light and the reference light are referenced to a same point, from the frequency distribution of the interference light obtained without handling the optical path length of the reference light. SUMMARY [0007] In case of the optical frequency domain imaging apparatus, the rotation speed of the mirror inside the catheter is made higher than it was before in order to heighten the resolution of the diagnosis image thereof. However, on the other hand, caused by the fact that the rotation speed is heightened, there arises such a problem as occurrence of its frictional heat. As mentioned above, since the catheter is an object inserted into the inside of a blood vessel, the less the influence of the frictional heat with respect to biological tissue is the better the result is. Also, the risk of breakdown is heightened by rotating the mirror at a high speed. Therefore, when rotating the mirror at a high speed, an upper limit is provided for a period during which the high speed rotation thereof is continued. Also, it is necessary for the timing of rotating the mirror at a high speed to match with the timing of carrying out the scan for obtaining the tomographic image of the targeted blood vessel region. [0008] On the other hand, it is also required to judge whether or not the catheter is positioned at the measurement region for obtaining the tomographic image and/or to carry out a confirmation process as to whether or not the mirror rotates normally or the like. In this confirmation process, it is sufficient if a rough tomographic image of the blood vessel can be obtained and it is enough if it can be confirmed, by watching the image thereof, whether or not the mirror rotates normally, so that there is no problem even if the rotation speed of the mirror on an occasion thereof is in a low-speed rotation in which the influence of frictional heat can be ignored. [0009] From the consideration mentioned above, the inventor here developed a conclusion about setting the rotation speed of the mirror into two stages. But the inventor here also became aware of the fact that there is a further problem in the case of providing an operation switch for simply instructing the high speed rotation and the low speed rotation respectively as desired. That is a problem in case of having instructed a high speed rotation by an erroneous operation. In a case in which the timing of instructing a scan for actually obtaining a tomographic image is near the continuation time-limit of the high speed rotation while not being aware of the fact that a high speed rotation has been instructed by an erroneous operation, the continuation time-limit is reached before the scan is completed and it happens that the measurement becomes invalid. Also, caused by the fact that a high speed rotation has been employed until the edge of the continuation time-limit, at that time point, the catheter becomes relatively in a high temperature. Therefore, it is desired, for the instruction of the high speed rotation again, to wait until there elapses a certain time period during which the temperature lowers adequately. [0010] Consequently, the disclosed here is an optical coherence tomographic diagnostic apparatus configured to avoid an operation error involving the rotation speed of the mirror portion as mentioned above, and which it makes it possible to carry out a scan superior in operability. [0011] The optical coherence tomographic image forming apparatus comprising a light source; an optical divider configured to divide a light outputted from the light source into a measurement light and a reference light; an optical probe insertable inside a body lumen and comprising an optical deflection unit provided at a distal end of the optical probe, the optical probe configured to emit the measurement light to the biological tissue and receive a reflected light; a drive unit configured to rotate the optical deflection unit centering around the axis thereof into the optical probe; and a signal processing unit configured to generate a cross-sectional image inside a biological tissue based on the light intensity of a interference light which is obtained from the reflected light and the reference light. The drive unit comprises: a first switch operable to instruct rotation of the optical deflection unit at a first speed; a second switch operable to instruct rotation of the optical deflection unit at a second speed higher than the first speed; and a driving controller configured to drive the optical deflection unit rotationally at the first speed upon detecting operation of the first switch and change the rotation speed of the optical deflection unit to the second speed upon detecting operation of the second switch, under a condition that the optical deflection unit rotates at the first speed when the second switch is operated. [0012] According to one aspect, the optical tomographic diagnostic apparatus disclosed here is constructed in a way that makes it difficult for erroneous operation, relating to the rotation speed of the mirror portion inside the probe, to occur. The apparatus is also well suited to performing a scan superior in operability. [0013] According to another aspect, an optical coherence tomographic image forming apparatus comprises: a light source which outputs light; an optical divider configured to divide light outputted from the light source into a measurement light and a reference light; an optical probe insertable inside a body lumen having biological tissue, the optical probe possessing a distal and portion at which is provided an optical deflection unit possessing an axis, the optical probe being configured to emit the measurement light toward the biological tissue which is reflected as reflected light and to receive the reflected light; a motor operatively connected to the optical deflection unit to rotate the optical deflection unit about the axis of the optical deflection unit at a first speed and a second speed higher than the first speed; a signal processing unit which receives information about light intensity of an interference light obtained from the reflected light and the reference light and uses said information to generate a cross-sectional image of the biological tissue inside the body lumen; and an operation unit operatively connected to the motor. The operation unit includes a first operating device which, upon operation, instructs the motor to rotate the optical deflection unit at the first speed, and a second operating device which, upon operation, instructs the motor to rotate the optical deflection unit at the second speed. A driving controller is configured to control the motor to rotationally drive the optical deflection unit at the first speed upon detecting operation of the first operating device, and to control the motor to rotationally drive the optical deflection unit at the second speed only when the second operating device is operated at a time when the optical deflection unit is rotating at the first speed. [0014] Another aspect of the disclosure here involves a control method for an optical coherent tomographic image forming apparatus which divides light outputted from a light source into a measurement light and a reference light and generates a cross-sectional image of biological tissue in a body lumen based on light intensity of an interference light obtained from a reflected light produced by emitting the measurement light toward the biological tissue and the reference light while rotating an optical deflection unit located at a distal end portion of the optical probe positioned in the body lumen. The method comprises rotating the optical deflection unit at a first rotation speed greater than zero while the optical deflection unit is positioned in the living body lumen and while light is emitted from the optical deflection unit, and increasing the rotation speed of the optical deflection unit to a second rotation speed higher than the first rotation speed upon detecting that an operating device has been operated at a time when the optical deflection unit is rotating at the first rotation speed. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a diagram showing an outward-appearance constitution of an imaging apparatus for diagnosis relating to an embodiment disclosed by way of example. [0016] FIG. 2 is a block diagram showing a functional constitution of an imaging apparatus for diagnosis. [0017] FIG. 3 is a block diagram showing a functional constitution of a signal processing unit. [0018] FIGS. 4A and 4B are diagrams explaining rotation scanning and axial-direction movement of an optical probe inside a blood vessel, and for explaining illumination of a measurement light and an intake of a reflected light. [0019] FIGS. 5A and 5B are schematic diagrams for explaining an operation of the optical probe inside the blood vessel. [0020] FIG. 6 is a diagram showing an operation unit of a scanner & pull-back unit. [0021] FIG. 7 is a flowchart showing a process procedure of a signal processing unit with respect to an operation by the operation unit of the scanner & pull-back unit. DETAILED DESCRIPTION [0022] Hereinafter, in accordance with the attached drawings, an embodiment disclosed by way of example will be explained in detail. [0023] [Explanation of Apparatus Structure and Operation] [0024] First of all, it will be explained with respect to the structure of the overall apparatus and operation in this embodiment. [0025] FIG. 1 is a diagram showing a system constitution and an outward-appearance constitution of a wavelength sweep type optical coherence tomographic (OCT) image forming apparatus (hereinafter, referred to as imaging apparatus for diagnosis) equipped with the constitution of the embodiment. As shown in FIG. 1 , the imaging apparatus for diagnosis 100 is provided with an optical probe unit 101 , a scanner & pull-back unit 102 and an operation control apparatus 103 . [0026] Also, since a flush liquid described later is made to flow to a blood vessel region targeted for diagnosis, a guiding catheter 115 housing the optical probe unit 101 is used. An insertion hole, into which the optical probe unit 101 is inserted as shown by the arrow in FIG. 1 , is provided at a rear end 115 a of this guiding catheter 115 and an opening portion for exposing the optical probe unit 101 to the outside is provided at a distal end 115 b. Then, this guiding catheter 115 is provided with a port 116 for connecting a medicine introducing portion 118 which accommodates the flush liquid described later. By operating this medicine introducing portion 118 , the flush liquid accommodated in the inside is discharged through the distal end portion 11 b. [0027] The scanner & pull-back unit 102 and the operation control apparatus 103 are connected by the signal line & optical fiber 104 . The guiding catheter 115 housing the optical probe unit 101 is directly inserted into a body lumen such as a blood vessel and the like, and the state inside the body lumen is measured by using an imaging core provided at a distal end of the optical probe unit 101 . This optical probe unit 101 is constituted by an optical fiber 236 which passes through the inside thereof and a catheter sheath 403 which covers the outside thereof, and at least the vicinity of the distal end portion thereof is constituted by a transparent member (details thereof will be described later). [0028] For the above-mentioned flush liquid, a physiological saline and a contrast agent (and a mixture liquid thereof) are used, and it is stored in the medicine introducing portion 118 . The medicine introducing portion 118 is composed, for example, of a syringe, accommodates the flush liquid, and makes the flush liquid flow from a catheter distal end into a blood vessel by pressing a plunger thereof. By replacing the blood with the flush liquid after pushing and flowing away the blood, it become possible to make the scanning in a state in which the effect of the hematocyte component is less exerted. Such an operation mentioned above is generally referred to as a flush operation, but the detail description thereof will be omitted here. [0029] The scanner & pull-back unit 102 regulates a radial operation of an imaging core inside the optical probe unit 101 by rotational motion performed by a built-in motor. Also, this scanner & pull-back unit 102 performs an operation (pull-back process) for pulling back the optical fiber 236 , which is rotating inside the optical probe unit 101 , at a constant speed by driving another built-in motor. By this pull-back process, it is possible to obtain a continuous blood vessel tomographic image which is along the axis of a blood vessel. Also, this scanner & pull-back unit 102 is provided with an operation portion 102 a which is arranged with various kinds of instruction switches for instructing the setting of the rotation speed, start/stop of the rotation and pullback of the optical fiber 236 inside the optical probe unit 101 . [0030] On an occasion when carrying out optical coherence tomographic image formation of biological tissue, the operation control apparatus 103 is provided with a function for inputting various kinds of setting values, a function for outputting measurement light, and a function for processing data obtained by measurement and displaying them as tomographic image. In the operation control apparatus 103 , a reference numeral 111 indicates a main body control unit, which processes data obtained by measurement and outputs a processed result. A reference numeral 111 - 1 indicates a printer & DVD recorder and it happens that the processed result in the main body control unit 111 is printed and is stored as data. A reference numeral 112 indicates an operation panel and a user carries out inputs of various kinds of setting values and instruction through the operation panel 112 . A reference numeral 113 indicates an LCD monitor as a display apparatus and it displays a processed result in the main body control unit 111 . [0031] FIG. 2 is a functional constitution diagram of the imaging apparatus for diagnosis 100 shown in FIG. 1 . In the drawing, a reference numeral 208 indicates a wavelength swept light source and a Swept Laser is used. The wavelength swept light source 208 is one kind of an Extended-cavity Laser which is composed of a light source portion 208 a having an optical fiber 217 connected with an SOA216 (semiconductor optical amplifier) in a ring shape and a polygon scanning filter 208 b. The light outputted from the SOA216 proceeds through the optical fiber 217 and enters the polygon scanning filter 208 b and the light whose wavelength is selected here is amplified by the SOA216 and finally, is outputted from a coupler 214 . In the polygon scanning filter 208 b, the wavelength is selected depending on the combination of a diffraction grating 212 for light-splitting the light and a polygon mirror 209 . The light which is light-split by the diffraction grating 212 is focused on the surface of the polygon mirror 209 depending on two lenses 210 , 211 . Thus, only the light of the wavelength perpendicular to the polygon mirror 209 returns to the same optical path and is outputted from the polygon scanning filter 208 b, so that it is possible to carry out the time sweep of the wavelength by rotating the polygon mirror 209 . For the polygon mirror 209 , for example, a 72-facets mirror is used and the rotation speed thereof is around 50000 rpm. Owing to the unique wavelength sweep system in which the polygon mirror 209 and the diffraction grating 212 are combined, it is possible to employ the wavelength sweep of high speed and high power. [0032] The light outputted from the coupler 214 of the wavelength swept light source 208 is made to enter one end of a first single mode fiber 230 . The first single mode fiber 230 is guided to an optical coupler 226 which is optically coupled with a second single mode fiber 231 and here, the light is transmitted by being branched into two paths. [0033] On the distal end side ahead of the photo coupler unit 226 of the first single mode fiber 230 , there is provided a scanner & pull-back unit 102 . Inside the scanner & pull-back unit 102 , there is provided an optical rotary joint (optical coupling unit) 203 which connects between a non-rotary portion (fixed portion) and a rotary portion (rotationally drive portion) and which transmits the light. Further, a fourth single mode fiber 235 provided on the distal end side of the optical rotary joint 203 is connected in a freely detachable manner with a fifth single mode fiber 236 through an adapter 202 . Thus, while repeating light transmission and reception, the light from the wavelength swept light source 208 is transmitted into an imaging core 201 which is rotationally driven. [0034] The light transmitted to the fifth single mode fiber 236 is illuminated from the distal end side of the imaging core 201 with respect to a biological tissue of a blood vessel while performing radial operation. Then, a portion of the reflected light which is scattered on the surface of or in the inside of the biological tissue is taken-in by the imaging core 201 and returns to the first single mode fiber 230 side by way of the reverse optical path, and a portion thereof moves to the second single mode fiber 237 side by the photo coupler unit 226 which has functions as a light splitting unit and a light coupling unit at the same time. In the photo coupler unit 226 , the reflected light is mixed with a reference light described below and is light-received as an interference light by a photo detector (in the embodiment disclosed by way of example, referred to as a photodiode, hereinafter as a PD) 219 . [0035] The rotation unit side of the optical rotary joint 203 is rotationally driven by a radial scanning motor 205 of the rotary drive apparatus 204 . Also, the rotary angle of the radial scanning motor 205 is detected by an encoder unit 206 . Further, the scanner & pull-back unit 102 is provided with a linear drive apparatus 207 and defines the insertion-direction (axial-direction) movement of the optical probe unit 101 based on an instruction from a signal processing unit 223 . The axial-direction movement is realized by a mechanism in which a linear drive motor inside the linear drive apparatus 207 operates based on a control signal from the signal processing unit 223 . [0036] Also, there is provided a variable mechanism 225 of the optical path length for fine-adjusting the optical path length of the reference light at a distal end on the distal end side from the photo coupler unit 226 of the second single mode fiber 231 . This variable mechanism 225 of this optical path length is provided with an optical path length adjuster for changing the optical path length which corresponds to the fluctuation of the length thereof such that the fluctuation of the length of the individual optical probe 201 can be absorbed in case of using the optical probe (imaging core) 201 by being exchanged. The second single mode fiber 231 and a collimator lens 234 are provided on a one-axis stage 232 which is freely movable in the optical axis direction thereof as shown by an arrow 233 and form the optical path length adjuster, [0037] More specifically, in case of exchanging the optical probe 201 , the one-axis stage 232 functions as an optical path length adjuster having such an amount of variable range of optical path length, which can absorb the fluctuation of the optical path length of the optical probe. Further, the one-axis stage 232 is provided also with a function as an adjuster for adjusting an offset. For example, even in a case in which the distal end of the optical probe 201 is not closely attached to the surface of the biological tissue, minutely changing the optical path length by the one-axis stage makes it possible to set a state of interference from the surface position of the biological tissue. [0038] The light reflected through mirrors 227 , 229 and a lens 228 is inputted to a second single mode fiber 231 as the reference light. The reference light whose optical path length is fine-adjusted by the variable mechanism 225 of the optical path length is mixed with the reflected light from the first single mode fiber 230 side at the photo coupler unit 226 which is provided on the way of the second single mode fiber 231 , and becomes the interference light, and it is light-received by the PD 219 . The light which is light-received by the PD 219 is photoelectrically converted and becomes an electric signal, and it is inputted to an amplifier 220 and amplified, and thereafter, it is supplied to a demodulator 221 . In this demodulator 221 , a demodulation process for extracting only the signal component of the interference light is carried out and the output thereof is inputted to an A/D converter 222 . [0039] In the A/D converter 222 , the interference light signal is applied with sampling, for example, by 180 MHz for 2048 points and digital data (interference data) of one line are generated. Note that the reason why the sampling frequency is set to be 180 MHz is on an assumption that about 90% of the period of wavelength sweep (12.5 ρsec) is extracted as digital data of 2048 points in case of setting the repetition frequency of wavelength sweep to be 80 kHz and it is not limited by this aspect in particular. [0040] The interference light data of one line unit, which are generated in the A/D converter 222 are inputted to the signal processing unit 223 . In this signal processing unit 223 , the interference light data are frequency-decomposed by FFT (Fast Fourier Transform) and data in the depth direction are generated, and by coordinate-converting these data, cross-sectional images at respective positions of the blood vessel are formed and outputted to an LCD monitor 113 by a predetermined frame rate. [0041] Note that the signal processing unit 223 is connected with an optical path length adjuster control unit 218 . The signal processing unit 223 carries out control of the position of the one-axis stage 232 by means of the optical path length adjuster control unit 218 . Also, the signal processing unit 223 is connected with a motor control circuit 224 and in synchronization with a video synchronization signal when forming a cross-sectional image, the cross-sectional image is stored in an internal memory. In addition, the video synchronization signal of this motor control circuit 224 is transmitted also to the rotary drive apparatus 204 and in the rotary drive apparatus 204 , a drive signal in synchronization with the video synchronization signal is outputted. Further, it happens that the signal processing unit 223 executes sampling of the interference light by the above-mentioned PD 219 and A/D converter 222 . [0042] FIG. 4A is a diagram for explaining an aspect in which the imaging core 201 of the optical probe unit 101 is inserted into a body lumen (into a blood vessel) and a radial scan is carried out. A catheter sheath 403 installed with the imaging core 201 which is constituted by the optical fiber 236 including an optical mirror 401 and an optical lens 402 at the distal end thereof is inserted into, for example, a blood vessel lumen. The rotary drive apparatus 204 rotates the imaging core 201 in an arrow 405 direction in the inside of the catheter sheath 403 and the linear drive apparatus 207 moves it toward the arrow 406 direction (pull-back process). At that time, as shown in FIG. 4B , the measurement light from the wavelength swept light source 208 is illuminated to the blood vessel wall by the optical mirror 401 by way of the optical fiber 236 . The reflected light to which the illuminated light is reflected is returned to the apparatus from the optical mirror 401 by way of the optical fiber 236 . More specifically, the optical mirror 401 has a function as an optical deflection unit which deflects the axial direction light of the optical probe unit 101 from the optical fiber 236 toward or in the direction of the body lumen wall. For the optical deflection unit, also a prism or the like can be used. [0043] FIGS. 5A and 5 b are schematic diagrams for explaining the operation of the optical probe unit 101 when imaging an intravascular tomographic image. FIGS. 5A and 5B are respectively a perspective view and a cross-sectional view of the blood vessel in a state in which the optical probe unit 101 is inserted thereinto. In FIG. 5A , a reference numeral 501 indicates a blood vessel cross-section into which the optical probe unit 101 is inserted. As described above, the imaging core 201 of the optical probe unit 101 is attached with the optical lens 402 and the optical mirror 401 at the distal end thereof and rotates in the direction shown by a reference numeral 405 in FIG. 5B depending on the radial scanning motor 205 . [0044] Depending on the optical lens 402 , transmission & reception of the measurement light are carried out at respective rotary angles. Lines 1 , 2 , . . . , 512 show illumination directions of the measurement light at respective rotary angles. In this embodiment disclosed as an example, while the imaging core 201 including the optical mirror 401 and the optical lens 402 rotates as much as the angle of 360 degree at the position of a predetermined blood vessel cross-section 501 , the transmission of measurement light & the reception of reflected light intermittently are carried out 512 times. Note that the number of times of the transmission & reception of the measurement light during a period of rotating 360 degrees is not limited by this aspect in particular and it is assumed that the number of times is settable arbitrarily. In this manner, the scan in which the transmission & reception of the signal is repeated while rotating the imaging core 201 is generally referred to as a “radial scan (rotation scan)”, Also, the transmission of the measurement light & the reception of the reflected light by such an imaging core 201 is carried out while the imaging core 201 proceeds in the inside of the blood vessel toward the arrow 406 direction (see FIG. 4A ). [0045] Note that for the rotation speed of the imaging core 201 in the embodiment disclosed by way of example, there are provided two kinds of speeds of 1800 rpm and 9600 rpm. The 1800 rpm is a speed for mainly confirming whether or not the distal end portion of the imaging core 201 has been positioned at the aimed region and confirming whether or not the imaging core 201 is rotating correctly, and by this number of rotation, the pulling-back (pull-back) of the imaging core is not carried out toward the arrow 406 direction in FIG. 4A . Hereinafter, this rotation process by 1800 rpm is referred to as a process of a radial scan mode. [0046] On the other hand, the 9600 rpm is a speed for obtaining a high-resolution blood vessel tomographic image and also, is a mode for obtaining an image in a predetermined range along the blood vessel axis. Accordingly, in this mode, the process of pull-back toward the arrow 406 direction in FIG. 4A is carried out while rotating the imaging core 201 by 9600 rpm. The flush operation explained previously (operation of injecting flush liquid) is carried out in this case. Hereinafter, this mode is referred to as a pull-back scan mode. The arrow 406 in FIG. 4A is the direction toward which the imaging core 201 is pulled back and it is opposite to the direction toward which the blood flows. When the flush operation is carried out, the medicine is outpoured toward the inside of the blood vessel from the distal end portion 115 b of the guiding catheter 115 by passing through the empty space between the guiding catheter 115 and the catheter sheath 403 , and at the portion thereof, the blood is drifted away and replaced by the medicine in which a flow without having an influence of the hematocyte component is produced. Then, during the pull-back operation, the distal end portion of the imaging core 201 moves in the area replaced by the medicine toward the arrow 406 direction and it become possible to scan for a highly accurate image. During the pull-back, the guiding catheter 115 is arranged at a position so as not to cover the distal end portion of the imaging core 201 . [0047] FIG. 3 shows a constitution of a signal processing unit 223 in the embodiment disclosed by way of example. This signal processing unit 223 carries out a generation process of the tomographic image based on an electric signal (signal from A/D converter 222 ) obtained from the interference light in the radial scan mode and the pull-back scan mode which are mentioned above in accordance with an instruction by an operator depending on the operation panel 112 and the operation unit 102 a. This generation process will be explained next. [0048] The signal processing unit 223 stores data of the interference light for one line by the wavelength sweep from the A/D converter 222 sequentially into a line memory unit 301 . Then, depending on an encoder signal of the motor, which is outputted from a motor control circuit 224 , signals are selected and grouped such that the number of lines per one rotation of the motor becomes 512 lines. More specifically, the interference light data per one line are outputted to the line data generation unit 302 by every 512 data per one rotation of the motor. [0049] The line data generation unit 302 generates the line data by carrying out an FFT (Fast Fourier Transform) process and concurrently, a line addition-averaging process, a filtering process, a logarithmic conversion and the like are carried out, and the obtained line data are outputted to a post-processing unit 303 at a subsequent stage. The line data is defined as data array which makes a line from center of the cross-sectional image to edge of the cross-sectional image. The line date is produced from coherence light intensity of the emission direction of the transmitting. [0050] In the post-processing unit 303 , a contrast adjustment, a brightness adjustment, a gamma correction, a frame correlation, a sharpness process and the like are applied for the line data received from the line data generation unit 302 , and the processed result thereof is outputted to an image construction unit 304 . The image construction unit 304 converts the line data train of polar-coordinate to a video signal and displays it on the LCD monitor 113 as blood vessel cross- sectional images. Note that as one example, there is shown, here, an example of constructing an image by 512 lines, but it is not to be limited by this number of lines. It happens that a control unit 305 controls a series of operations of the respective units mentioned above, but the contents of calculation until the blood vessel tomographic image is obtained and portions relating to the display process thereof do not directly concern the embodiment, so that further detailed explanations will be omitted. [0051] [Explanation of User Interface] [0052] Next, it will be explained with respect to user interface for an operator in the embodiment disclosed by way of example. First, before moving to an explanation of the user interface, set forth will be an explanation of premise or peripherally related portions. [0053] As explained previously, for the scan mode in this example of an embodiment, there are the radial scan mode (process for making the optical mirror 401 rotate by 1800 rpm) and the pull-back scan mode (pull-back process of the optical fiber 236 in which the optical mirror 401 is rotated by 9600 rpm and the optical mirror 401 is made to move by a constant speed toward the arrow 406 direction in FIG. 4 ). [0054] Problems are not caused by rotation at 1800 rpm, but when the optical fiber 236 (optical mirror 401 ) is rotated in the catheter sheath by a high speed such as 9600 rpm, frictional heat is generated there and it happens that the temperature of the catheter sheath will heighten or increase. Therefore, it is not desirable for the biological tissue on the outside of the catheter sheath to continue the rotation (high speed rotation) for a long period. In addition, there also occurs a possibility which leads to breakages of the optical fiber 236 and the optical mirror 401 . Consequently, it was required to set the duration time of the rotation speed referred to as 9600 rpm to be within 42 seconds maximally and more specifically, to provide a limiter for the duration time of the high speed rotation of the pull-back scan mode. [0055] However, in a case in which it happens that the operator instructs the high speed rotation by 9600 rpm caused by an erroneous operation and it happens that the pull-back scan is instructed without being aware of a fact that the high speed rotation thereof continues nearly for 42 seconds, it happens that the duration time terminates on the way of the scan and the rotation stops, so that complete measurement data cannot be obtained. Therefore, it is necessary to prevent such an erroneous operation as much as possible. Note that the above-mentioned 42 seconds as the maximum duration time is merely presented as one example and it is a value which is suitably changeable. [0056] Also, as explained previously, the pull-back scan mode is a mode in which the tomographic image of a predetermined distance of the blood vessel is scanned while carrying out the pull-back of the optical fiber, so that it is necessary to provide time for achieving the movement over the predetermined distance until the scan is completed. Therefore, the timing for starting the pull-back process has to be set within a time period which is obtained by subtracting as much as an amount of time necessary for the pull-back process thereof from the maximum duration time (42 seconds) by 9600 rpm. Although depending on the length of the scan, in this embodiment disclosed by way of example, it is assumed that the rotation is to be stopped if the start instruction of the pull-back process is not carried out within 30 seconds after the rotation speed becomes 9600 rpm. [0057] In light of the foregoing, according to FIG. 6 showing one example of the operation unit 102 a in the scanner & pull-back unit 102 and FIG. 7 showing a process procedure, there will be explained processes (process contents of the signal processing unit 223 ) relating to the user interface in an embodiment. [0058] As shown in FIG. 6 , in the operation unit 102 a provided at the scanner & pull-back unit 102 , there are provided a switch 610 for stopping the rotation of the optical fiber 236 , a switch 620 for instructing a shifting to the radial scan mode (1800 rpm), a switch 630 for instructing an entering to the pull-back scan mode and a shifting to a state in which the pull-back is possible (9600 rpm), and a switch 640 for carrying out a start instruction of the pull-back. The switches (inclusive of buttons which are also acceptable) are examples of operating devices for initiating the respective noted operations. Also, those switches are installed with LEDs 611 , 621 , 631 , 641 as lighting display devices for notifying the states of the switches respectively. The relationships between driving states of the LEDs and functional states of the switches are as follows. [0059] LED turned off: Indicating a state in which the function of the switch thereof is not expressed [0060] LED turned on: Indicating a state in which the function of the switch thereof is expressed [0061] LED blinking: Indicating a transitional state until the function of the switch thereof is expressed [0062] Since it is enough if only the state can be distinguished, it is possible to employ another driving method than the driving method for the LEDs, which was mentioned above. Depending on the case, it is possible to prepare LEDs having a number of light-emitting colors and to change the light-emitting colors in response to the state. [0063] Also, the operation unit 102 a is provided with a display unit 650 for countdown-displaying the remaining number of seconds during which the pull-back switch 640 can be pushed down when the rotation becomes 9600 rpm. [0064] Hereinafter, there will be explained processes of the signal processing unit 223 in an embodiment disclosed by way of example in accordance with a flowchart in FIG. 7 . [0065] First, the signal processing unit 223 carries out, in step S 1 , an initial process of each constituent element used for an optical coherence tomographic image formation process. Within this process, there are included a turn-on process of the LED 621 for notifying the fact that the radial scan switch 620 functions, and turn-off processes of the LEDs 611 , 631 , 641 for notifying the fact that other switches do not function. It becomes a situation in which the operator carries out, in this state, an operation for guiding the optical probe unit 101 to the inside of the blood vessel in the diagnosis region of a patient. [0066] The operator pushes down the radial scan switch 620 in order to confirm the position of the optical probe 201 , to fine-adjust the position and to confirm whether or not the optical mirror portion 401 rotates normally. When the signal processing unit 223 detects the push-down of this radial scan switch 620 (“Yes” in step S 2 ), the driving of the radial scanning motor 205 is carried out for making the optical fiber 236 rotate by 1800 rpm. At that time, the LED of the radial switch 620 is put into a blinking state. Note that even if a switch other than the radial scan switch 620 within the switch group shown in FIG. 6 is pushed down, that is ignored. The configuration in which the push-down of a switch lying in a turned-off state is ignored will be similar also in the explanation hereinafter. [0067] Then, in step S 3 , when it is judged that the speed has reached 1800 rpm, there is carried out a process for obtaining the tomographic image at the rotation speed thereof and there is carried out a process for displaying the image thereof on the LCD monitor 113 (step S 4 ). As a result thereof, it is possible for the operator to confirm and fine-adjust the position of the optical mirror portion 401 and confirm whether or not the optical mirror portion 401 rotates normally. In this situation, in order to obtain a more accurate image, it sometimes happens that the operator carries out a flush operation using a small amount of medicine (operation of making the medicine at the medicine introducing portion 120 flow out from the distal end portion 115 b of the guiding catheter 115 ). Also, in the course of carrying out the process of this step S 4 , the LEDs 611 , 631 are turned on, thus providing notification that the push-downs of the stop switch 610 and the pull-back ready switch 630 are to be regarded as effective, and the system then waits for the detection of the push-down of any one of the switches (steps S 5 , S 6 ). [0068] Here, when the push-down of the stop switch 610 is detected, the signal processing unit 223 stops the rotation of the optical fiber 236 in step S 7 and the process is returned to step S 1 . [0069] On the other hand, when the push-down of the pull-back ready switch 630 is detected, the signal processing unit 223 carries out the driving of the radial scanning motor 205 in order to rotate the optical fiber 236 by 9600 rpm and concurrently, blinks the LED 631 (step S 6 ). Then, in step S 8 , the system waits until the rotation speed reaches 9600 rpm. [0070] When the speed reaches 9600 rpm, it becomes a state in which the pullback is possible, there is started the countdown of the residual time (30 seconds in the embodiment) until it is no longer possible to carry out the pullback, and there is started displaying of the residual time thereof on the display unit 650 (step S 9 ). During this countdown, the switches which the operator can operate are the stop switch 610 and the pull-back switch 640 , so that the respective LEDs 611 , 641 are turned on and the LEDs 621 , 631 of the other switches are turned off. [0071] The signal processing unit 223 judges whether or not the remaining number of seconds by the countdown is zero second in step S 10 and whether or not any one of the stop switch 610 and the pull-back switch 640 has been pushed down in steps S 11 , S 12 , and looping takes place in S 10 to S 12 until any one is judged. Note that if the speed is allowed to return to 1800 rpm, it is allowed during this looping to turn on the LED 621 , to carry out a process of judging whether or not the radial scan switch 620 has been pushed down and to return the process to step S 3 when the push-down thereof is detected. [0072] Now, in the looping mentioned above, in a case in which the remaining number of seconds by the countdown has become zero second or the push-down of the stop switch 611 has been detected, the process proceeds to step S 7 , stops the rotation of the optical fiber 236 and returns to step S 1 . At that time, the LED 641 is turned off. [0073] On the other hand, when the push-down of the pull-back switch 640 is detected (at that time, operator is carrying out flush operation for introducing medicine into a blood vessel from medicine introducing portion 118 ), the process proceeds to step S 13 . Here, the signal processing unit 223 starts driving of the linear drive apparatus 207 and carries out the process of pulling the optical fiber 236 (rotating at 9600 rpm) by a predetermined speed as much as a distance which is set beforehand. During that period, as explained previously, there is carried out the sampling of the electric signal of the interference light by the A/D converter 222 and there is carried out the process for obtaining the three-dimensional tomographic images of the blood vessel. During this pull-back process, the LED 641 of the pull-back switch 640 is blinking and the LEDs of the other switches are turned off. In this manner, when the pull-back of the optical fiber 236 for the necessary distance is finished, the process proceeds to step S 14 , the process of the pull-back is terminated and the rotation of the optical fiber 236 is stopped. At that time, all of the LEDs are turned off. Thereafter, the process proceeds to step S 15 and information such as the obtained interference light data and the like is stored in a memory unit of a hard disk or the like which is not shown, and this process is finished. [0074] As explained above, according to this embodiment, it is not possible to shift to such a high-speed rotation as 9600 rpm without undergoing such a low-speed rotation as 1800 rpm for carrying out the confirmation operation, so that in a non-rotation state, even if the pull-back ready switch is pushed down by an erroneous operation, it is possible to treat the operation thereof as invalid and it become possible to improve safety and operability. Also, there can be obtained a situation in which whether or not each switch is effective can be confirmed by the driving state of the LED provided at each switch and it becomes more possible to prevent erroneous operations. Note that to provide the stage of such a low-speed rotation as 1800 rpm is useful for carrying out various kinds of the confirmation operations for which high-speed rotation is not required, and it becomes effective in case of avoiding heat generation and breakdown. [0075] Note that in the embodiment, an example was explained in which each switch is arranged at the scanner & pull-back unit 102 . Instead of or in addition to this aspect, it is also allowed for a similar switch to be provided at the operation panel 112 or to be displayed on the LCD monitor 113 . [0076] Also, in the embodiment disclosed by way of example embodiment, examples of 1800 rpm and 9600 rpm were explained for the rotation speeds of the optical fiber 236 , but the present invention is not to be limited by these rotation numbers. It is needless to say that the length of time for counting down also varies depending on the apparatus constitution and/or the setting, so that the present invention is not to be limited by the embodiments mentioned above. [0077] The detailed description above describes features and aspects of an embodiment of an optical coherence tomographic image forming apparatus and associated control method disclosed by way of example. The invention is not limited, however, to the precise embodiment and variations described. Various changes, modifications and equivalents could be effected by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims

An optical coherent tomographic image forming apparatus includes: a first switch for instructing rotation of the optical deflection unit at a first speed; a second switch for instructing rotation of the optical deflection unit at a second speed which is higher than the first speed; and a driving controller which drives the optical deflection unit rotationally at the first speed in case of detecting instruction operation of the first switch and which changes the rotation speed of the optical deflection unit to the second speed, in case of detecting instruction operation of the second switch, under the condition that the optical deflection unit rotates at the first speed when the second switch is instructionally operated.

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for producing soybean curd, and more particularly to an apparatus for producing in large quantities fine-textured soybean curd ("kinugoshi tofu") as placed in containers, i.e., soybean curd which is obtained by coagulating a mixture of soybean milk and a coagulant as placed in containers without dewatering and molding. As disclosed, for example, in Unexamined Japanese Patent Publication No. 94648/1991, apparatus of the type mentioned are already known which comprise means for filling a mixture of soybean milk and a coagulant into coagulating buckets, means for heating the mixture to coagulate the mixture into soybean curd, means for placing a receiving member on the curd in each of the buckets without dewatering the curd, bucket inverting means for inverting the bucket and the receiving member as placed on the soybean curd, means for withdrawing the soybean curd as supported on the receiving member from the bucket by moving down the inverted receiving member, covering means for placing an inverted container over the soybean curd on the receiving member, and means for inverting the inverted container. When withdrawn as supported on the receiving member from the bucket, the fine-textured soybean curd, which is very soft, liable to deform and fragile unlike harder or coarse-textured soybean curd ("momen tofu"), readily deforms. If the container is placed over the deformed curd, the container is likely to cut off part of the curd, which becomes a faulty product. The ratio of occurrence of such rejects is usually 7 to 10% and is by no means low. SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for efficiently producing fine-textured soybean curd or kinugoshi tofu as placed in containers with occurrence of rejects prevented. The apparatus of the present invention for producing fine-textured soybean curd as placed in containers comprises means for filling a mixture of soybean milk and a coagulant into coagulating buckets, means for heating the mixture to coagulate the mixture into soybean curd, covering means for placing an inverted container over each of the buckets to cover an upper-end opening of the bucket without dewatering the soybean curd within the bucket, means for inverting the bucket and the container as placed over the bucket, and means for withdrawing the soybean curd as accommodated in the container from the bucket by moving down the inverted container. With the soybean curd producing apparatus described, the soybean curd coagulated within the bucket is transferred directly to the container without being withdrawn from the bucket. This eliminates the likelihood that the curd will be partly cut off by the container during transfer from the bucket to the container, precluding occurrence of rejects. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal view in vertical section showing the construction of an apparatus embodying the invention; and FIGS. 2a-2d are diagrams illustrating the operation of the apparatus. DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the invention will be described below with reference to the drawings. In the following description, the terms "front" and "rear" are used with reference to FIG. 1; the right-hand side of FIG. 1 will be referred to as "front," and the opposite side thereof as "rear." The terms "right" and "left" will be used for the apparatus as it is seen toward the front. FIG. 1 shows an apparatus for producing fine-textured soybean curd or "kinugoshi tofu," which comprises a lower chamber 13 having an upward extension chamber 11 formed at the front end of its top and having an upward communication opening 12 formed in a top wall portion close to its rear end, an upper chamber 15 having a downward communication opening 14 formed in its bottom wall and communicating with the opening 12, and a bucket conveyor 16 provided in both the lower chamber 13 and the upper chamber 15 and extending through the two openings 12, 14. The lower and upper chambers 13, 15 are each closed. Aseptic air is supplied to the lower chamber 13 to maintain the interior thereof at a positive pressure. Steam is supplied to the upper chamber 15 to maintain the interior thereof at a high temperature of about 95° C. The extension chamber 11 has a top wall formed with a container inlet 23. The lower chamber 13 has a bottom wall formed with a container outlet 24 in a front end portion thereof. The bucket conveyor 16 comprises a pair of right and left endless chains 31 movable in circulation within the lower and upper chambers 13, 15, a multiplicity of slats 32 connected between the chains 31 and arranged at a predetermined spacing, and a plurality of buckets 33 attached to each of the slats 32 (see FIG. 2). Each of the chains 31 is reeved around an intermittently driving sprocket 34 disposed in an interior front portion of the lower chamber 13 and a plurality of driven sprockets 35 arranged at required portions inside the two chambers 13, 15. The buckets 33 are movable along an upper path 31a extending generally forward within the lower chamber 13, a lower path 31b extending rearward below the upper path 31a, an inverting path 31c interconnecting the front ends of the upper path 31a and the lower path 31b, and a zigzag path 31d deflected upward from an intermediate portion of the upper path 31a to extend into the upper chamber 15, further extending upward while zigzagging forward and rearward within the upper chamber 15, and then directed downward to join the upper path 31a. Each of the slats 32 is pivotably connected at each of its opposite ends to the chain 31 by an unillustrated horizontal pin, whereby the buckets 33 thereon are so positioned in a spontaneous state that their openings are directed upward at all times. Each bucket 33 has a capacity to accommodate an amount of soybean curd corresponding to a piece of soybean curd of specified size (about 400 c.c. on the average) with an allowance, and is made of a plastics so as to be inexpensive to make. If heat conductivity and durability are more important than the cost, the bucket may be made of stainless steel. A top wall rear portion of the lower chamber 13 is provided with a filling device 17. The filling device 17 has filling nozzles 36 positioned at the rear end of the upper path 31a of movement of the chains and extending through the top wall rear portion of the lower chamber 13. Disposed inside the extension chamber 11 is a covering device 19 positioned at the front end of the upper path 31a of movement of the chains. The covering device 19 comprises magazines 38 arranged along the edge of the container inlet 23 and each accommodating a multiplicity of containers C as oriented upward and stacked up, and vacuum cups 39 each arranged between the magazine 38 and the path of movement of the conveyor immediately therebelow, movable upward and downward and invertible through 180 degrees. A separating device 18 is disposed to the rear of the covering device 19 at a short distance therefrom. The separating device 18 has separating members 37 each movable vertically into or out of the bucket 33. The separating member 37 is in the form of a tube shaped generally in conformity with the inner periphery of the bucket 33. A widthdrawing device 21 is disposed at the front end of the lower path 31b of movement of the chains. A washing device 22 is disposed slightly to the rear of the device 21 and has wash liquor jet nozzles 44 oriented upward toward the path 31b from therebelow. The wash liquor is, for example, aseptic water. Container inverting guide rails 41 are arranged along the inverting path 31c of the chains and the lower path 31b to extend to the position of the washing device 22. The withdrawing device 21 has container receivers 42 L-shaped in cross section and movable upward and downward through the container outlet 24. A container discharge converyor 43 extends forward from a position immediately adjacent to the container receivers 42 as located at the lower limit position of their upward and downward movement. When each bucket 33 is brought to below the filling nozzle 36, the nozzle 36 fills a mixture of soybean milk and coagulant in an amount corresponding to one piece of soybean curd as stated previously into the bucket 33 (see FIG. 2a). The coagulant is magnesium chloride (bittern). The mixture is prepared from soybean milk and the coagulant which are cooled to below than the coagulating temperature by mixing together these ingredients immediately before filling. Instead of quick-acting coagulants typical of which is magnesium chloride, slow-acting coagulants, such as calcium sulfate, may be used. In this case, the soybean milk as heated to not lower than the coagulating temperature and the coagulant are individually filled into the bucket with stirring, and aseptic air having ordinary temperature is supplied to the upper chamber instead of the supply of steam. The buckets 33 filled with the mixture move upward out of the lower chamber 13 into the upper chamber 15, travel zigzag within the upper chamber 15 and finally move downward to enter the lower chamber 13 again. In the meantime, the buckets 33 remain directed upward. The time taken for the buckets 33 to pass through the upper chamber 15 is about 30 minutes, and during this period, the mixture within the buckets 33 coagulates into soybean curd. When each bucket 33 having the soybean curd accommodated therein is brought to below the separating member 33, the separating member 33 lowers into the bucket 33 while moving along the inner peripheral surface of the bucket 33, whereby the periphery of the curd within the bucket 33 is separated from the bucket 33. When the bucket 33 is subsequently brought to below the covering device 19, the vacuum cup 39 attracts thereto from the magazine 38 a container C with its opening up, turns upside down while lowering and places the container C as inverted thereby over the bucket 33 (see FIG. 2b) While the bucket 33 so far remains directed upward, the bucket 33 is thereafter restrained from pivotally moving by itself by the guide rail 41 while moving from the front end of the upper path 31a to an intermediate portion of the lower path 31b. In the meantime, the bucket 33 as covered with the container C is directed downward, allowing the soybean curd to move inside the bucket 33 and to be supported by the bottom of the container C (FIG. 2c). The container C receiving the soybean curd along with the bucket 33 then reaches a position above the container outlet 24, whereupon the container receiver 42 receives the bottom of the container C and lowers, whereby the container C is moved away from the bucket 33 for the transfer of the curd to the container C (FIG. 2d). The container C accommodating the soybean curd is delivered from the lower chamber 13 onto the container discharge conveyor 43 through the container outelt 24. The bucket 33 separated from the container C is washed with a wash liquor forced out from the nozzle 44 and is thereafter released from the guide rail 41, whereupon the bucket 33 turns by itself to an upwardly directed position again. The bucket 33 thereafter reaches the position below the filling nozzle 36, whereby one cycle of production operation is completed.

An apparatus for producing fine-textured soybean curd as placed in containers comprises means for filling a mixture of soybean milk and a coagulant into coagulating buckets, means for heating the mixture to coagulate the mixture into soybean curd, covering means for placing an inverted container over each of the buckets to cover an upper-end opening of the bucket without dewatering the soybean curd within the bucket, means for inverting the bucket and the container as placed over the bucket, and means for withdrawing the soybean curd as accommodated in the container from the bucket by moving down the inverted container.

BACKGROUND OF THE INVENTION In oil and gas well drilling operations, drilling fluid is circulated through the drill string, returning formation drill cuttings to the surface through the annulus. The formation drill cuttings are removed from the drilling fluid so that the drill fluid may be reused. A "shale shaker" is typically used for this purpose, which results in drill cuttings accumulating in a trough. The accumulated drill cuttings must be removed from the trough and appropriate disposal must be arranged. Several methods for removing drill cuttings from the shale shaker trough are known, including various configurations of conveyors, chutes, suction lines, tanks, and other devices. Industry experience has shown that the utilization of a suction line provides several benefits not found in other methods including easier installation, quicker installation, less moving parts, improved safety, lower maintenance, and reduced expense. Current methods and apparatus utilized in the suction line methods suffer, among other things, from an inability to dispose of the suctioned drill cuttings without interrupting the suction force. This causes substantial delays, and attempts to address this problem have not proven satisfactory. One known method of utilizing a suction line to remove drill cuttings from the shale shaker trough, involves a tank in which a suction is created, drawing drill cuttings into the tank until full. Once full, however, the suction force must be broken, the suction force connection equipment must be removed from the tank, and the tank must be sealed for removal and replacement by an empty tank. This method in particular has been known to cause substantial delays. Another method involves a single hopper in which a suction force is created, again drawing drill cuttings into the hopper until full. This method also suffers in that the suction force must be terminated in order for the hopper to be opened for discharge of the accumulated drill cuttings. Known suction line methods also suffer from an inability to properly and efficiently adapt to various methods of disposing of the drill cuttings once they have been removed from the shale shaker trough. For example, although the suction line method utilizing a single hopper can be configured to discharge from the single hopper into a "slurrification unit," the method does not appropriately address the presence of two receiving tanks on most of such slurry units. A slurrification unit typically has two circulating systems, each involving the formulation of a slurry consisting of water and the drill cuttings, with the slurry being circulated, and the cuttings ground to a sufficiently small size for ultimate discharge to an injection pump. The injection pump forces the slurry down the well for reintroduction into porous formations. Any suction line method having only a single hopper discharging into only one slurrification unit tank, fails to take full advantage of the capabilities of the two tank slurrification unit dual circulating systems. Methods and apparatus are needed which will provide suction line retrieval of drill cuttings from the shale shaker trough, provide continuous suction force in the system, enable efficient post-suction collection and disposal of the drill cuttings, and fully complement the two tank slurrification unit system. SUMMARY OF THE INVENTION Our invention provides methods and apparatus for suctioning drill cuttings from a shale shaker trough, using a continuous suction force in the system, and further enabling efficient post-suction collection and disposal of the drill cuttings. Such methods and apparatus are fully complementary to a slurrification unit system having two tanks and two corresponding circulation systems. Our suctioning method involves a suction force which pulls cuttings from the shale shaker trough. The cuttings are pulled, in an alternative fashion, to a first hopper and then a second hopper. When a hopper has the appropriate amount of drill cuttings accumulated within it, suction is broken within that hopper only, and the cuttings are discharged into one or more receptacles. In a similar manner, suction is broken in the other hopper when it has received the appropriate amount of drill cuttings, followed by cuttings discharge. These steps are timed such that the first hopper discharges cuttings while the second hopper is filling and the second hopper discharges cuttings while the first hopper is filling. Our suctioning method can be accomplished such that the suctioning force is continuously present at the shale shaker trough, and in either the first or the second hopper. It can also be accomplished such that the receipt of cuttings into the first hopper, the breaking of the suction force in the second hopper, and the discharge of cuttings from the second hopper begin simultaneously, or substantially simultaneously, and similarly, that the receipt of cuttings into the second hopper, the breaking of the suction force in the first hopper, and the discharge of cuttings from the first hopper also begin simultaneously, or substantially simultaneously. A blower provides the suction force, and our invention includes the capturing of any liquids in the air after the air leaves the hoppers, but before it reaches the blower. Our invention includes several improved methods of receiving suctioned drill cuttings after the first post-suction accumulation. For example, the two hoppers can be spaced and located in appropriate proximity to a "train" of receptacles, such that the filled receptacle can be moved and replaced by an empty receptacle during a period of non-discharge from our two hopper system. This exchange of receptacles can be accomplished with no cessation of the suctioning force. Embodiments such as this can be readily utilized both onshore and offshore. Our invention also provides for the reception of discharged drill cuttings from the first hopper into a first receptacle and from the second hopper into a second receptacle. With the hopper so configured, a two "train" system for moving and replacing receptacles is provided. Our invention also includes the movement of the two hoppers from a first discharge location to a second discharge location, such that a different receptacle is being filled at each location. This multiple receptacle method allows the movement and replacement of a filled container while the hoppers are above a different container. Also included as a method in our invention is the spacing of the first and second hoppers for even distribution of the discharged drill cuttings into a receptacle. Our invention includes the positioning of the hoppers off of the drilling rig prior to receiving drill cuttings. This allows the discharge of the drill cuttings from the hoppers to occur in a wide variety of receptacles, such as barges, other ships with storage compartments, trucks, etc. Our invention is particularly adaptable to compartmentalized receptacles. The hoppers can be spaced such that the first and second hoppers coincide with pairs of compartments within a single receptacle. Furthermore, the hoppers can be moved in such a fashion as to analogously coincide with additional pairs of compartments. Moving such a receptacle with respect to stationary hoppers is also included. Our invention also provides for the hoppers to be mounted on, and moved along, guide fixtures and combinations of guide frames and guide fixtures. This allows the placement of cuttings in an evenly distributed fashion in single opening receptacles, and also allows movement between compartments on compartmentalized receptacles, e.g. barges. Both lateral and longitudinal movement is provided, as well as, independent movement of the hoppers with respect to each other. Mounting each hopper on an independent guide fixture is also included. Our invention also includes the routing of the discharged cuttings from the two hoppers to a common point for further routing. Such further routing can be along a single path or can be divided into two or more paths, for alternate discharge routing into two or more receptacles. Our invention includes both a redirectable single discharge routing and a dual discharge routing, both of which will be particularly adaptable to the two tank slurrification unit system. In this application, the combined discharged cuttings from both hoppers would be first directed to the slurrification unit first tank, and at an appropriate time, redirected to the slurrification unit second tank. For this purpose our invention includes various configurations of chutes and screw conveyors. Our invention also includes the further treatment of the cuttings with subsequent discharge and injection into porous formations in the wellbore. The slurrification unit operation, can be performed with two isolated circulating systems, as well as, a commingled system, in which case the two slurrification unit circulation systems share either all or part of the slurried cuttings. Furthermore, our invention improves the method of discharging the cuttings from both hoppers into a single slurrification unit tank without subsequent redirection. Prior methods, having only one hopper, required that the suction force at the shale shaker trough be terminated during the discharge of cuttings from the hopper. In our invention, this suction force can be continuous. Our invention also includes the movement of the two hoppers for discharge, first into the slurrification unit first tank, and then to the slurrification unit second tank. In the many configurations involving the slurrification unit, our invention also includes the step of filtering the discharge from such slurry units, catching oversized particles and recirculating them for further grinding. Our invention includes the use of more than two hoppers, with method and apparatus variations and adaptations which correspond to analogous variations and adaptations described for two hoppers. Our invention includes apparatus for moving drill cuttings from a cuttings collection point to one or more receptacles, which comprises a first and second hopper, each hopper having a cuttings inlet, an air outlet, and a cuttings discharge outlet, a common suction line having a first end and a second end, a first independent suction line and a second independent suction line, the first independent suction line being in suction communication with the first hopper cuttings inlet and a common suction line second end, the second end suction line being in suction communication with the second hopper cuttings inlet and the common suction line second end, suction force means (or suction force introduction means), a common exit line, having a first and a second end, the common exit line first end being in suction communication with the suction force means such that the suction force means creates a suction force in the common exit line, a first independent exit line and a second independent exit line, the first independent exit line being in suction communication with the common exit line second end and the first hopper air outlet, the second independent exit line being in suction communication with the common exit line second end and the second hopper air outlet, suction alternating means such that the suction force means repeatedly creates a suction force in one of the first or second hoppers, then the other of the first or second hoppers, but in only one of such hoppers at any one instant, the suction force drawing drill cuttings through the common suction line first end, when the common suction line first end is placed in proximity to drill cuttings in the cuttings collection point, and a first hopper discharge valve and a second hopper discharge valve for allowing cuttings to be respectively discharged from the first and second hoppers during intervals in which no suction force is present in the discharging hopper. Our invention also includes such apparatus wherein the first hopper discharge valve, the second hopper discharge valve, and the suction alternating means are coordinated such that the opening of the first hopper discharge valve and the termination of the suction force in the first hopper begin simultaneously, or substantially simultaneously, and the opening of the second hopper discharge valve and the termination of the suction force in the second hopper begin simultaneously, or substantially simultaneously. Preferred embodiments of our invention include the configuration of the suction alternating means such that the suction force is continuously present in either the first or second hopper; or, in another embodiment, that the suction force is continuously present at the cuttings collection point, i.e. at the common suction line first end. In a preferred embodiment of our invention, the suction alternating means includes a diverter valve positioned on the common suction line such that suction communication between the common suction line and either of the first or the second independent suction lines can be broken, the diverter valve being interconnected with the first independent exit line valve, the second independent exit line valve, the first hopper discharge valve, and the second hopper discharge valve, such that, when the first independent exit line closes, the second independent exit line valve opens, the first hopper discharge valve opens, the second hopper discharge valve closes, and the diverter valve breaks suction communication with the first independent suction line, and further such that, when the first independent exit line valve opens, the second independent exit line closes, the first hopper discharge valve closes, the second hopper discharge valve opens, and the diverter valve breaks suction communication with the second independent suction line. In another embodiment, the first independent exit line valve, the second independent exit line valve, the first hopper discharge valve, and the second hopper discharge valve are interconnected such that, when the first independent exit line closes, the second independent exit line valve opens, the first hopper discharge valve opens, and the second hopper discharge valve closes, and further such that, when the first independent exit line valve opens, the second independent exit line valve closes, the first hopper discharge valve closes, and the second hopper discharge valve opens. In another embodiment, the suction alternating means includes a suction-operated first independent suction line valve and a suction-operated second independent suction line valve, the first independent suction line valve closing the first independent suction line when a suction force is in the second independent suction line, the second independent suction line valve closing the second independent suction line when a suction force is in the first independent suction line. In another embodiment, the first and second hopper discharge valve, each comprised a hinged flap, hinge with respect to the hopper cuttings discharge outlets, such that the hinge flap closes the hopper cuttings discharge outlet when a suction force is present within the hopper. Our invention also includes a vibrator for both hoppers, which causes the cuttings to discharge more freely. Similarly, one or more air jets are included for agitating and dislodging cuttings from the interior walls of the first and second hoppers. Such air jets can be postponed to effect a circumferential pattern. A clean out access hatch is also provided for both the first and second hoppers. Our invention also comprises a hopper guide frame, the hopper guide frame being configured to support and secure the first and second hoppers, the hopper guide frame further having one or more tracks with the first and second hoppers being movable along these tracks. The movement of the first and second hoppers may be independent. Another embodiment of our invention includes a hopper support frame where the hopper support frame is configured to support and secure one or more hoppers, and a hopper support frame guide fixture which is sized and configured such that it supports the hopper support frame. This hopper support frame guide fixture has one or more tracks and the hopper support frame is attached to such tracks such that the hopper support frame is movable along the hopper support frame guide fixture tracks. Our invention also includes additional hopper support frames on the hopper support frame guide fixture, as well as, two or more hopper support frames on two or more hopper support frame guide fixtures. Powered movement and direction of the hoppers and the hopper support frame is also provided. In another embodiment, longitudinally expandable first and second independent suction lines and exit lines are also included which will allow a variable space between the first and second hoppers. In our invention, when the formation drill cuttings have collected in the shale shaker trough, a suction force is created in a common suction line having an end in such drill cuttings, the common suction line then dividing into a first independent suction line and a second independent suction line, these lines being in suction communication with a first hopper and a second hopper respectively, the first and second hoppers being in suction communication with a first independent exit line and a second independent exit line respectively, the first and second independent exit lines joining to form a common exit line which extends ultimately to a suction-creatingblower, the first and second exit lines, common exit line and blower being in suction communication. The suction force in the first hopper is removed by closing a first independent exit line valve and breaking suction communication between the first independent suction line and the common suction line. The suction force in the second hopper is initiated by opening a second independent line valve. Drill cuttings are then received from the common suction line, through the second independent suction line, into the second hopper, until the desired amount of drill cuttings are in the second hopper. The suction force is then removed from the second hopper by closing a second independent exit line valve and breaking suction communication between the second independent suction line and the common suction line. Drill cuttings are discharged from the second hopper through a second hopper discharge opening by opening a second hopper discharge opening valve. The suction force in the first hopper is initiated by opening the first independent exit line valve and restoring suction communication between the first independent suction line and the common suction line. Drill cuttings are received from the common suction line, through the first independent suction line, into the first hopper, until the desired amount of drill cuttings are in the first hopper. The suction force is removed from the first hopper by closing the first independent exit line valve and isolating the first independent suction line from the common suction line. Drill cuttings are discharged from the first hopper through a first hopper discharge opening by opening a first hopper discharge opening valve. These steps are repeated for as many cycles as necessary to accommodate the volume of drill cuttings which must be addressed. Our invention includes, in a preferred embodiment, that the steps of closing the first independent exit line valve, breaking suction communication between the first independent suction line and the common suction line, opening the first hopper discharge opening valve, and opening the second independent exit line occur simultaneously, or substantially simultaneously, and that the steps of closing the second independent exit line valve, breaking suction communication between the second independent suction line and the common suction line, opening the second hopper discharge opening valve, and closing the first independent exit line valve occur simultaneously, or substantially simultaneously. In another embodiment the common suction line is eliminated and the first independent suction line and the second independent suction line both extend to the cuttings collection point, i.e. the shale shaker trough. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of the drill cuttings transfer system. FIG. 2 is a top view of the dual hopper portion of the system. FIG. 3 is a side view of the dual hopper portion of the system. FIG. 4 is a schematic representation of an embodiment of the system in use on a jack-up rig, with a barge for a receptacle. FIG. 5 is a side view of the rig and barge in FIG. 4 FIG. 6 is an end view of the barge with the dual hopper portion of the system in place. FIG. 7 is a top view of the barge with the dual hopper portion of the system in place. FIG. 8 is a schematic representation of an embodiment of the invention where the system is utilized on a jack-up rig with a barge. FIG. 9 is a side view of the rig and barge in FIG. 8. FIG. 10 is a top view schematic representation of an embodiment of the invention utilized on an offshore rig, with several barges in position to be serviced. FIG. 11 is a top view schematic representation of an on rig utilization of the system, with containers depicted. FIG. 12 is a top view of the dual hopper portion of the system with the related structure for servicing the containers in FIG. 11. FIG. 13 is a side view of the application depicted in FIG. 13. FIG. 14 is a top view schematic representation of the on rig utilization of the system in FIG. 11, with the equipment reoriented in order to fill two containers simultaneously. FIG. 15 is a side view of the application in FIG. 14. FIG. 16 is a side view schematic representation of an embodiment of the invention in which the structure allows movement of the hoppers with respect to each other. FIG. 17 is a schematic representation of an embodiment of the invention in which two tanks of a slurrification unit receive cuttings from the dual hopper portion of the system. FIG. 18 is a schematic representation of an embodiment of the invention in which two tanks of a slurrification unit receive cuttings from the dual hopper portion of the system. FIG. 19 is a schematic indicating the electrical and pneumatic circuits which control the valves and vibrators in the dual hopper portion of the system. DESCRIPTION A drill cuttings transfer system 10 is depicted in FIG. 1. Drill cuttings accumulate in a cuttings collection point 12, normally the trough associated with a shale shaker. The suction force in a common suction line 14 draws the cuttings into the common suction line 14 first end 16. At the common suction line 14 second end 18, the cuttings are diverted to either of a first independent suction line 20 or a second independent suction line 22. In a preferred embodiment shown in FIG. 1, the common suction line 14 is flexible. A first and second hopper 24,26 each have a cuttings inlet 28,30, air outlets 32,34, and cuttings discharge outlets 36,38. Air and cuttings are received into the first and second hoppers 24,26 through the cuttings inlets 28,30. Within the hopper, the cuttings are cyclonically separated. The air exits the first and second hoppers 24,26 through the air outlets 32,34, while the cuttings accumulate within the first and second hoppers 24,26 through the cuttings discharge outlets 36,38. The FIG. 1 embodiment includes a pneumatically operated common suction line diverter valve which allows cuttings to enter only one of the first or second independent suction lines 20,22 at a time. The DGP Pneumatic diverter valve by Bush & Wilton Valves, Inc., is a satisfactory choice to accomplish this result, although simpler combinations of flaps, check valves, and even manually operated ball valves, gate valves, etc., can also accomplish the same result. First and second independent exit lines 42,44 receive air from the air outlets 32,34, and in the embodiment depicted in FIG. 1, a pneumatically operated three-way valve 46 is situated with respect to such exit lines 42,44 such that air is being withdrawn from only one of the first and second hoppers 24,26, at a time. FIGS. 2-3 provide additional views showing the placement of the three-way valve 46 with respect to air outlets 32,34. The first and second independent exit lines 42,44 merge to form a common exit line 48. The common exit line 48, in the embodiment depicted in FIG. 1, is in suction communication with a scrubber 50 for a final separation of solids in the form of fines, from the air, prior to the air being drawn into the blower 52. The three-way valve function an be executed by several well-known combinations of valves and actuating cylinders. In the embodiment shown in FIG. 1, they three-way valve 46 includes two butterfly valves, an actuating cylinder, pneumatic lines, and T-linkage linking the valves. The scrubber 50 provides a vertical path for the air allowing any liquid to fall to the bottom. A scrubber outlet valve is connected to a float which closes the valve when liquids in the scrubber 50 reach a predetermined level. It is anticipated that the blower 52 will be sized at approximately 3,000 cfm and be powered by a 125 HP electric motor. It is anticipated that the blower 52, or other suction creating devices, will be sized to form a continuous vacuum at 15 inches of mercury, and an intermittent vacuum at 22 inches of mercury. The Roots 624 RCS positive rotary lobe blower will satisfactorily perform this function. In the embodiment depicted in FIG. 1, the accumulated cuttings in first and second hoppers 24,26 exit through cuttings discharge outlets 36,38 when such outlets 36,38 are opened using cuttings discharge outlet valves 54,56. The pneumatically operated SB Series, SBT-Pneumatic (twin cylinder) slide valve by Bush & Wilton Valves, Inc., is satisfactory for this application. The cuttings discharge is enhanced by the use of pneumatically operated vibrators 58,60 placed in the vicinity of the cuttings discharge outlets 36,38 on each of the first and second hoppers 24,26. The "MARTIN" "VIBROLLER" vibrator, Model UCVR4-.05 is satisfactory for this application. The common exit line 48 is flexible in the embodiment depicted in FIG. 1. The first and second hoppers 24,26 are secured by a frame 58 in the embodiment depicted in FIG. 1. This frame 58 can be shaped and configured to enable numerous configurations and applications of this system 10. In the embodiment depicted in FIG. 1, the first and second hoppers 24,26 are generally cyclonic and can-shaped, having a cone-shaped discharge and an elliptical head. A timer, or manual operation, can be utilized to coordinate the operation of the three-way valve 46, the cuttings discharge outlet valves 54,56 and the common suction line diverter valve 40 in a manner such that the suction force is continuously present in either the first or the second hopper 24,26 continuously present at the cuttings collection point 12, and at the required openings and closings of such valves 40,46,54,56 occur simultaneously, or substantially simultaneously. A preferred embodiment is shown in the FIG. 19 schematic in which the valves 40,46,54,56 are coordinated such that the system 10 is in one of two modes of operation, at all times, but not simultaneously. In the first mode, the common suction line diverter valve 40 opens the first independent suction line 20 and closes the second independent suction line 22, the three-way valve 46 opens the first independent exit line 42 and closes the second independent exit line 44, the first hopper cuttings discharge outlet valve 54 is closed and the second hopper cuttings discharge outlet valve 56 is open. In this first mode, cuttings are being drawn through the first independent suction line 20 into the first hopper 24, where they accumulate as the air exits through the first independent exit line 42. Any cuttings in the second hopper 26 will fall, or will have fallen, through the open second hopper cuttings discharge outlet 38. In the second mode, the common suction line diverter valve 40 closes the first independent suction line 20 and opens the second independent suction line 22, the three-way valve 46 closes the first independent exit line 42 and opens the second independent exit line 44, the first hopper cuttings discharge outlet valve 54 is open and the second hopper cuttings discharge outlet valve 56 is closed. In this second mode, cuttings are being drawn through the second independent suction line 22 into the second hopper 26, where they accumulate as the air exits through the second independent exit line 44. Any cuttings in the first hopper 24 will fall, or will have fallen, through the open first hopper cuttings discharge outlet 36. Although most embodiments are readily adaptable to interconnected and fully automated valve combinations, it is also contemplated within our invention, that manual operation of some or all of the valves is feasible. The drill cuttings transfer system 10 is readily adaptable to numerous applications in both the onshore and offshore drilling environments. FIGS. 4-7 depict various views of an offshore drilling environment involving a jack-up rig 100, a barge 102, and several compartments 104 for storing cuttings on the barge 102, the compartments 104 being open-topped. Symbolic representations of certain components of the system 10 are also depicted. In this preferred embodiment, the hopper frame 58 is positioned on cross members 106 which span the width of the barge 102, the cross members 106 having rollers 108, the rollers 108 being situated along tracks 110, such that the cross members 106 can move along the length of the barge 102. In other embodiments, it is also contemplated that a similar roller and track arrangement could be provided to allow lateral movement of the frame 58 with respect to the length of the barge 102. In all cases, a variety of common devices could be utilized to power the movement of the hoppers 24,26 with respect to the barge 102, with remote control operation included. Freestanding diesel motors, electric motors, and other power sources can be readily adapted through ordinary automotive coupling arrangements. The frame 58, or the cross member 106 and frame 58 combination, can be placed and removed by a crane. FIG. 10 is an example of the adaptability of the system 10 to a multi-barge 102 situation, where the barges can be conveniently placed adjacent the rig 100 and still be filled due to the flexibility of the system 10. FIG. 10 also depicts variations contemplated with respect to the position of the frame 58, the cross members 106, and the barge 102. FIGS. 8-9 depict embodiments of the invention in which the first and second hoppers 24,26 are independently movable along the tracks 110 in a barge 102 application. FIGS. 11-13 depict an additional embodiment in which the system 10 fills containers on the rig surface in an offshore drilling environment. In this embodiment, the frame 58 is placed upon a elevated structure which allows containers 152 to be moved to a position beneath the frame 58 such that the cuttings can be discharged into the containers 152. The containers 152 can be skidded or rolled into appropriate positions beneath the structure 150 and the frame 58 to enable an efficient distribution of the cuttings within the container 152. The containers 152 can be of the type with open tops, sliding door tops, etc. When removed from the other end of the structure 150 the containers 152 can be removed by a crane. FIGS. 14-15 depict an embodiment of the invention in which the frame 58 and structure 150 are oriented such that two containers 152 can be positioned beneath the structure 150, each container 152 being filled by a different hopper 24,26. FIG. 16 depicts an embodiment of the invention in which the first and second hoppers 24,26 can be moved with respect to each other, the variable spacing of the hoppers 24,26 allowing optimum distribution of the cuttings within a container 152. FIGS. 17-18 depict embodiments whereby the system 10 is coordinated with a two-tank slurrification unit 200. Slurry units 200 receive cuttings into one or more tanks 202,204 form a slurry using a liquid, usually salt water, circulating the slurry, and grinding the cuttings in the slurry during the circulation process. The slurry containing the appropriately ground cuttings is discharged from the slurrification unit 200 for disposal into the wellbore for injection into an appropriate subsurface formation. One or more holding tanks 206 usually receive the slurry in preparation for injection pumping. In a slurrification unit 200 application, FIG. 17 depicts the discharge chutes 208,210 which receive cuttings from the first and second hopper cuttings discharge outlets 36,38. A cuttings discharge chute diverter 212 diverts the cuttings to either or both of the slurrification unit tanks 202,204. FIG. 18 depicts the application whereby the cuttings discharge chutes 208,210 direct the cuttings to a common articulated chute 214, the common articulated chute 214 being positioned to direct the cuttings to either of the slurrification unit tanks 202,204. In another embodiment, both the first and second hoppers 24,26 can be positioned to discharge directly into only one of the slurrification unit tanks 202,204. Similarly, in another embodiment, both the first and second hoppers 24,26 discharge cuttings into either one of the slurrification unit tanks 202,204, or a screw conveyor apparatus for directing all or part of the cuttings to the other slurrification unit tank 202,204. The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification, in connection with this application, and which are open to public inspection with this specification. The contents of all such papers and documents are incorporated herein by reference. Although the present invention has been described in considerable detail with reference to certain preferred and alternate embodiments thereof, other embodiments are possible. Accordingly, the spirit and scope of the claims should not be limited to the description of the embodiments contained herein.

Methods and apparatus are provided for the uninterrupted transfer of oil and gas well drill cuttings from a collection point, such as a shale shaker trough, to several types of variously configured on rig and off rig receptacles. Two or more hoppers are arranged for alternating receipt and discharge of cuttings, the cuttings being continuously drawn to the hoppers by a suction force from an upstream blower. The receptacles utilized in the various embodiments are varied, such as barges, box containers, and slurry units. The hoppers are, in some embodiments, moved to remote locations, such as off rig barges, prior to beginning the cuttings transfer.

This is a continuation of application Ser. No. 08/129,995, filed Sep. 30, 1993 now U.S. Pat. No. 5,430,057. FIELD OF THE INVENTION The present invention relates to a form of busulfan useful for the suppression of malignancy in humans. BACKGROUND OF THE INVENTION Busulfan [1,4-bis-(methanesulfonoxyl)butane], is a bifunctional alkylating agent which was first described by Haddow and Timmis (1953). Since the demonstration of its potent antitumor effects, it has been used extensively for treatment of malignant disease, especially hematologic malignancies and myeloproliferative syndromes (Galton, 1953; Ambs et al., 1971; Abe, 1975; Canellos, 1985; Hughes and Goldman, 1991; Collis, 1980). Its use was for long time limited to low dose oral therapy with palliative intent and frequent monitoring of the blood counts was routinely recommended (Canellos, 1985; Hughes and Goldman, 1991; Collis, 1980). The advent of some 2 to 3% of the patients developing busulfan-induced pulmonary fibrosis (Collis, 1980; Koch and Lesch, 1976; Oakhill et al., 1981), as well as occasionally severe, sometimes even irreversible myelosuppression after prolonged administration effectively deterred dose escalation beyond 8-10 mg daily (Canellos, 1985; Hughes and Goldman, 1991; Ganda and Mangalik, 1973; Albrecht et al., 1971). In 1974, however, Santos and Tutschka investigated the use of busulfan to create a murine model of aplastic leukemia (Santos and Tutschka, 1974; Tutschka and Santos, 1975). Subsequently, the experience gained in this model system was used to introduce high-dose combination chemotherapy based on oral busulfan for pretransplant-conditioning of primates (Buckner, 1975), and subsequently patients undergoing both autologous and allogeneic marrow transplantation (Santos et al., 1983; Lu et al., 1984; Yeager et al., 1986; Tutschka et al., 1987; Peter et al., 1987; Copelan et al., 1989; Geller et al., 1989; Grochow et al., 1989; Sheridan et al., 1989). Since then, high dose busulfan, most commonly in combination with cyclophosphamide, has proven to be a most effective antileukemic regimen when used in conjunction with autologous or allogeneic hematopoietic stem cell support. A recent comparison between busulfan/cyclophosphamide (BuCy) and cyclophosphamide (Cy) combined with total body irradiation (TBI) for preparation of patients with hematologic malignancies undergoing allogeneic marrow transplantation illustrated that the BuCy regimen was well tolerated and at least as effective as the TBI-based regimen (Miller et al., 1991; Buckner et al., 1992; Schwertfeger et al.; 1992). High-dose busulfan therapy has several advantages for use in marrow ablation/pretransplant treatment. First, when using chemotherapy alone for conditioning of patients undergoing marrow transplantation, one avoids the dependence on a radiation unit with, usually, limited capacity to deliver the necessary treatment on a fixed schedule. Second, high total-radiation doses are very toxic, especially to the lungs, and may require special protective measures (shielding). Such excessive toxicity is usually not seen with combination chemotherapy. Third, a radiation based regimen can only be delivered to patients who have not been previously irradiated. Many patients with lymphoma, Hodgkin's disease and leukemia have had previous (extensive) radiation for control of locally aggressive disease in sanctuary sites like the central nervous system or to sites of bulky disease such as the mediastinum or the neck. Additional radiation as part of the pretransplantation conditioning regimen may cause irreversible and often fatal toxicity in such cases. However, a majority of previously radiated patients can safely receive a busulfan-based regimen, provided that the previous acute radiation toxicity (usually within the first 2-4 months after therapy) has subsided. Fourth, in selected patients who suffer recurrent leukemia after allogeneic marrow grafting, a second marrow transplant may still offer a chance for long-term disease control or even cure (Vaughn et al., 1991; Champlin et al., 1985; Sanders et al., 1988; Blume et al., 1987). Due to subclinical (irreversible) toxicity, a TBI-based regimen can only be utilized once in a patient's life time, whereas combination chemotherapy can be employed following a previous TBI-regimen. Busulfan-based chemotherapy will, therefore, serve as a valid alternative. Oral busulfan has, unfortunately, several serious shortcomings. Thus, when used in high dose combinations with cyclophosphamide (and possibly additional chemotherapeutic agents), serious side effects in the liver and lungs are often encountered (Collis, 1980; Koch et al., 1976; Santos et al., 1983). Thus, several investigators have reported veno-occlusive disease (VOD) of the liver, leading to fatal liver failure, as the most serious side effect (Yeager et al., 1986; Geller et al. 1989; Grochow et al., 1989; Miller et al., 1991). Neurological disturbances like grand mal seizures and severe nausea and vomiting are also frequently encountered (Grigg et al., 1989; Marcus et al., 1984; Martell et al., 1987; Sureda et al., 1989; Vassal et al., 1990). It is impossible to predict which patients will develop liver failure, and it is further unknown whether the liver failure is due to toxicity from the systemic busulfan or whether it is mainly due to a first-pass phenomenon when busulfan is absorbed from the intestinal tract. Based on the somewhat sketchy information that is available on busulfan pharmacokinetics, it appears however, that patients who absorb a large fraction of the ingested dose, with a prolonged high busulfan plasma concentration, will be at increased risk for developing serious side effects (Marcus et al. 1984; Vassal et al., 1990). Another disadvantage with oral busulfan is, that patients who develop severe nausea and vomiting shortly (within 1-2 hours) after a dose has been delivered, will lose part of or the entire dose, and it may be virtually impossible to accurately determine how much of the dose has been lost in a vomiting subject. Further, the intestinal resorption of any delivered drug may be influenced by the patient's nutritional state, and by concurrent administration of other drugs affecting the intestinal microenvironment, as well as by whether the patient has eaten in close proximity to ingestion of the administered drug dose and, finally, by the inherent biological variability in intestinal absorption between different patients (Benet et al., 1985). Due to these uncertainties, oral administration of high-dose busulfan carries with it an inherent safety problem both from the potential danger of inadvertent overdosing with a risk for (lethal) toxicities, as well as from the hazard of (suboptimal) underdosing the patient with an inadvertently high potential for recurrent or persistent malignancy after the marrow transplant. The in vivo distribution of busulfan labeled with the positron-emitting radionuclide carbon 11 was investigated in cynomolgus monkeys and in a human patient using positron emission tomography (Hassan et al., 1992). Radiotracer amounts of 11C-busulfan in a saline solution containing 10% ethanol were injected as an i.v. bolus. The concentration of busulfan was not reported but was likely insignificant compared to therapeutic levels. M Hassan has indicated to the inventor that the total dose injected was estimated at 1-2 μg. Giles et al. (1984) reportedly used busulfan to induce platelet dysfunction in rabbits by an intraperitoneal injection of busulfan dissolved in polyethyleneglycol at a dose of 60 mg/kg. The concentration of the solution is not given, and due to the slow solubilization of the busulfan, the authors heated the mixture excessively to promote mixing. This may have caused significant chemical degradation of the busulfan. Furthermore, busulfan given intraperitoneally is very toxic and causes significant local tissue damage. An abstract of Kitamura's article (Kitamura, et al., 1979) relates to the well-known use of busulfan and cyclophosphamide which are typically given orally. The 32 p is reported to have been administered intravenously. In a study of bone marrow transplantation in the busulfan-treated rat, Tutschka and Santos reportedly injected busulfan prepared in 2.5% carboxymethylcellulose in water i.p.. This injection also causes significant local tissue damage. To circumvent the above shortcomings and hazards from oral administration of busulfan for chemotherapy with myeloablative intent, a chemically stable busulfan formulation that can be safely administered parenterally, i.e., via the intravenous (i.v.) route is needed. ABBREVIATIONS AUC=Area under the curve BSF=Busulfan BuCy=Busulfan/cyclophosphamide CGA=N-(2,6-difluorobenzoyl)-N-[3,5-dichloro-4-(3-chloro-5-trifluoromethylpyridin-2-yloxy)phenyl]urea Cy=Cyclophosphamide DDCB=1,4-Bis(diethyldithiocarbamoyl)butane DDTC=Sodium diethyldithiocarbamate DMA=N',N-dimethylacetamide DMSO=Dimethylsulfoxide HBCD=hydroxypropylbetacyclodextrin MTT=3,(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium-bromide PEG=Polyethyleneglycol PG=Propyleneglycol TBI=Total body irradiation THF=Tetrahydrofuran TVP=Total volume percent SUMMARY OF THE INVENTION The present invention involves methodology for dissolving busulfan in a liquid vehicle(s) to provide a physiologically acceptable busulfan formulation for parenteral administration, such that the busulfan remains chemically stable and can be administered without unexpected toxicity from undissolved busulfan or from the liquid vehicle when the formulation is administered parenterally to the recipient at maximally tolerated busulfan doses. In a broader sense, the present invention describes a method of administering busulfan parenterally as to avoid the erratic intestinal absorption that is experienced after oral administration of this agent, thereby circumventing the unpredictable and sometimes lethal toxicity. The present invention provides a method for treating malignant disease in an individual. The method comprises the parenteral administration of a pharmaceutically effective amount of busulfan dissolved in a water miscible, physiologically acceptable busulfan solvent. The mixture of dissolved busulfan and solvent may further include water. Malignant disease may be a tumor, a hematologic malignancy, a myeloproliferative syndrome, leukemia, or a disease requiring bone marrow transplantation, for example. A pharmaceutically effective amount of dissolved busulfan is an amount that achieves a therapeutic goal. A physiologically acceptable solvent is a solvent which is tolerated by the individual in the concentrations and doses used. The water miscible, physiologically acceptable busulfan solvent is a solvent that dissolves busulfan and may be N',N-dimethylacetamide, an aqueous solution of polyethyleneglycol or a mixture of N'N-dimethylacetamide and an aqueous carrier solution allowing busulfan solubility and stability. The aqueous carrier solution may be a polyethylene glycol solution. The administration may be intravascular or intravenous. The concentration of N'N-dimethylacetamide is 5%-99%, preferably 5%-15% or 15%-25%, and the concentration of polyethyleneglycol is 5%-50%. The polyethyleneglycol may have a molecular weight between 200 and 2,000 daltons, more preferably between 350 and 450 daltons. One skilled in the art would realize that polyethyleneglycol solutions of various molecular weights could be used as long as they are physiologically acceptable. The dissolved busulfan may have a concentration of 1-75 mg/ml. A further embodiment of the present invention is a pharmaceutically acceptable formulation for parenteral administration of busulfan. The formulation comprises busulfan dissolved in a water miscible, physiologically acceptable busulfan solvent at a concentration of 1-75 mg/ml. The formulation may further comprise water. The water miscible busulfan solvent may be N',N-dimethylacetamide, an aqueous solution of polyethyleneglycol or a mixture of N'N-dimethylacetamide and an aqueous carrier solution allowing busulfan solubility and stability. The aqueous carrier solution may be a polyethylene glycol solution. The N'N-dimethylacetamide is at a concentration of 5%-99% and the polyethyleneglycol is at a concentration of 5%-50%. The polyethyleneglycol may have a molecular weight between 200 and 2,000 daltons, more preferably between 350 and 450 daltons. The busulfan solvent may be propylene glycol or an aqueous solution of hydroxypropylbetacyclodextrin. The present invention provides for further pharmaceutically acceptable formulations for parenteral administration of busulfan, for example, formulations comprising 1-7.5 mg/ml dissolved busulfan, 35%-45% polyethyleneglycol, 45%-55% water, and 5%-15% N'N-dimethylacetamide. A preferred embodiment is a pharmaceutically acceptable formulation for parenteral administration of busulfan comprising 1-15 mg/ml dissolved busulfan, 35-45% polyethyleneglycol-400, 35-45% water and 15-25% N',N-dimethylacetamide A method of preparing a pharmaceutically acceptable formulation for parenteral administration of busulfan is an aspect of the present invention. The method comprises the steps of i) dissolving busulfan in a water miscible, physiologically acceptable busulfan solvent to yield a working solution of busulfan; and ii) diluting the busulfan working solution with an aqueous carrier solution allowing busulfan solubility and stability to yield a pharmaceutically acceptable formulation for parenteral administration of busulfan. A further method comprises the step of dissolving busulfan at a concentration of 1-75 mg/ml in a water miscible, physiologically acceptable busulfan solvent. The solvent may be N'N-dimethylacetamide or an aqueous solution of polyethyleneglycol. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B and 1C schematically display the chemical structure of busulfan as free drug 1 A and derivatized with diethyldithiocarbamate sodium 1 B to yield 1,4-bis(diethyldithiocarbamoyl) butane 1 C (DDCB) after extraction for HPLC analysis. FIG. 2 shows busulfan equilibrium solubility with time in various concentrations of HBCD formulations. FIG. 3 shows busulfan equilibrium solubility with time in various concentrations of PEG-400 formulations. FIG. 4 shows the hemolytic effects of 40% PEG-400 with and without busulfan on human erythrocytes. FIG. 5 shows the hemolytic effects of 50% PEG-400 with and without busulfan on human erythrocytes. FIG. 6 shows the hemolytic effects of 10% HBCD with and without busulfan on human erythrocytes. FIG. 7 shows the stability of busulfan at different concentrations in the 20% DMA/40% PEG-400 aqueous vehicle at 22° C. FIG. 8 shows comparative plasma profiles of busulfan. The drug was administered to fasting or non-fasting rats as tablets, as an oral solution in 40% PEG-400, or as an i.v. bolus of busulfan in 40% PEG-400. FIG. 9 shows the plasma concentration profiles in rats of i.v. administered busulfan dissolved at 3 mg/ml in acetone or in DMSO or in the 20% DMA/40% PEG-400 aqueous vehicle. The total volume injected was 100-150 μL and the dose of busulfan was 1 mg/kg body weight. All solutions were prepared fresh immediately prior to administration. FIG. 10 shows in vitro cytotoxic activity of the DMA:PEG-400 aqueous vehicle on human KBM-3 cells without or with busulfan. KBM-3 cells exposed to busulfan dissolved in a low, non-toxic amount of acetone served as a positive control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention provides methods and compositions useful for parenteral administration of particular formulations of busulfan to assist in the control of malignant disease. This route of administration has not been previously explored in the clinical practice of oncology. The parenteral administration of this chemotherapeutic agent makes it possible to avoid the erratic intestinal absorption that makes oral administration of high dose busulfan suboptimal. The present examples show that the diluent vehicles used in the parenteral preparation of busulfan are effective to dissolve the drug in a chemically stable fashion, such that the drug retains its cytotoxic properties. The vehicles are acceptable to laboratory animals and humans in the proposed concentrations and total doses to be used; PEG-400 has been previously evaluated clinically for use as a carrier of L-asparaginase in the treatment of lymphocytic leukemia and lymphoma, and no unexpected or adverse toxicity attributable to the use of this vehicle was experienced (Keating et al., 1993). Other PEG sizes which are pharmaceutically acceptable may be likewise used. DMA has previously been used as a stock diluent for Amsacrine when used in clinical studies of treatment for acute myeloid leukemia, where no serious adverse effects attributable to the DMA have been documented. DMA has been used in phase I studies as an anticancer agent in man (Weiss et al., 1962). The dose-limiting toxicities were hepatic dysfunction, hypotension and mental excitatory states in patients treated with doses of at least 400 mg/kg body weight daily for 4-5 days or cumulative doses exceeding 88 g, but all the toxicity was reversible on the cessation of treatment (Weiss et al., 1962). As an alternative solvent, propylene glycol has been cited as harmless when taken internally, probably because its oxidation yields pyruvic and acetic acids (Merck Index, 11th Ed., 1989). The data presented herein from a murine model indicate that the parenteral busulfan preparation provides a substantially higher bioavailability than any of the oral preparations tested. Specifically, the DMA/aqueous PEG-400/busulfan solution is chemically stable, easy to prepare and handle at room temperature, and provides reliable and easily controllable dosing with 100% bioavailability. For comparison, while busulfan can be dissolved at 25 mg/ml in acetone, this solvent is highly hemolytic and unacceptable for use as a clinical solvent in humans. Alternatively, e.g., DMSO could be considered as an effective solvent of busulfan. DMSO is, however, a chemically highly reactive reagent, which rapidly degrades busulfan, making it an unsuitable solvent for clinical routine use. In an experimental situation, both acetone and DMSO can be utilized as solvents for busulfan, and pharmacokinetic data were obtained with these vehicles for comparison to busulfan dissolved in the DMA/PEG-400 aqueous solvent system. Oral busulfan administration gives a wide range of resulting plasma concentrations which influence the resulting toxicity profile, especially when the drug is used in supralethal doses as part of pretransplant conditioning regimens. The clinical experience with busulfan underlines the general problem of giving optimal therapy when using the oral route of administration for a chemotherapeutic agent. The present invention provides high-dose parenteral busulfan therapy for the treatment of malignant disease, while substantially circumventing the inherent problems of erratic intestinal absorption, first-pass effects, toxicity, and liver metabolism of the administered agent. The present invention provides the opportunity to design and execute pharmacologic and therapeutic studies of high-dose busulfan-based therapy for malignant disease with hematopoietic stem cell support in an optimally controlled fashion, such that for the first time a valid comparison can be performed between a busulfan-based and other chemotherapy- vs. TBI-based conditioning regimens. Furthermore, the chemically stable busulfan preparation can be used for regional therapy such as isolated limb perfusion, and local treatment of malignant effusions in the pleural space and peritoneal cavity. There is a severe shortage of chemotherapeutic drugs that can be successfully used in the local treatment of malignant effusions. Malignant cells may be eradicated from the body by administering busulfan-based chemotherapy in high doses. The present invention of a parenteral preparation of busulfan represents a new and more effective tool for administering precise doses of such therapy while diminishing the risk of suffering life-threatening or lethal adverse effects as a result of the administered treatment. Unless defined otherwise, 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. All percentages are weight/volume percentages unless otherwise noted. EXAMPLE 1 A Formulation of Busulfan Acceptable for Parenteral Administration The present example provides formulations of prototype parenteral preparations of busulfan with estimates of different degrees of solubility determined with a newly developed high pressure liquid chromatography (HPLC) assay for busulfan. METHODOLOGY Calculation of Desired Target Solubility. Busulfan has a solubility of only 25 μg/ml in water at room temperature. The currently used high-dose busulfan regimens prescribe an estimated daily dose of 280 mg for a 70-kg subject (1 mg/kg body weight every 6 hours) (Santos et al., 1983; Yeager et al., 1986). With a clinically safe maximum infusion rate of about 4-5 ml/min over 120 minutes, the busulfan should be dissolved at a concentration of at least 2-4 mg/ml. This requires at least an 80 fold increase in solubility over the aforementioned. Approaches to Enhance Busulfan Solubility in Aqueous Solution. Polyethyleneglycol-(PEG) 400 - aqueous solvent system; solvents of combinations of PEG-400, propyleneglycol (PG) and glycerin; N'N-dimethylacetamide and combinations of N',N-dimethylacetamide with 40% PEG-400 in aqueous solution were examined. A cyclodextran aqueous medium was tested. For limited comparative pharmacokinetic studies in the murine model, busulfan was also dissolved in pure acetone and in DMSO at 3 mg/ml immediately prior to intravenous administration. The detailed vehicle system compositions are shown in Table 1. TABLE 1______________________________________Solvent Systems for Parenteral Formulation of BusulfanIngredient Formulation Number(%, w/v) 1 2 3 4 5 6 7 8 9 10______________________________________PEG-400 30 10 40 10 0 40 40 0 0 0PG 10 10 0 10 0 0 0 0 0 0Glycerin 10 30 0 10 0 0 0 0 0 0Cyclodextran 0 0 0 0 7 0 0 0 0 0Water 50 50 60 70 93 40 50 0 0 0DMA 0 0 0 0 0 20 10 0 0 100Acetone 0 0 0 0 0 0 0 100 0 0DMSO 0 0 0 0 0 0 0 0 100 0______________________________________ A known amount of busulfan was equilibrated in the solvent system at 20° C. for predetermined periods of time. An aliquot was then removed and subjected to HPLC assay after an appropriate dilution for determining busulfan concentration and stability. HPLC Assay. The most sensitive detection system for busulfan in the HPLC assay would utilize an absorbance or fluorescence detector operating in the ultraviolet (UV) spectrum. However, the busulfan molecule has no UV absorbing chromophore in its structure, and therefore, derivatization with a chromophore is mandatory to facilitate the use of a UV detector in the HPLC assay. Derivatization. A modification of the procedure of MacKicham and Bechtel was employed (MacKicham et al., 1990). Briefly, diethyldithiocarbamate sodium was used as the derivatizing agent to yield 1,4-bis(diethyldithiocarbamoyl) butane (FIG. 1) with peaks of absorbance max at 278 and 254 nm. Conditions for the HPLC Assay. The derivatized product was separated from the reaction mixture using Sep-Pak™ C18 solid phase extraction vials (Waters Chromatography Systems Inc., Millford, Mass.). Two HPLC systems were evaluated. The different mobile phase systems are shown in Table 2. TABLE 2______________________________________HPLC Conditions Assay-1 Assay-2______________________________________Column C18 C18Mobile phase Acetonitrile:Water:THF Methanol:Water (55:25:20 v/v, pH 4.2) (81:19 v/v)Flow rate 0.8-1.0 ml/min 1.0 ml/minUV Absorb. 254 (and 278) nm 254 and 278 nmChart speed 20 cm/hr 10 cm/hrInt. std. (CGA-112913).sup.b urea, 500 μg/mlRet. time:DDCB 7.5 min 8.4 minInt. std. 8.7-9.0 min 10.2 min______________________________________ .sup.b CGA-112913; N(2,6,-difluorobenzoyl)-N-[3,5,-dichloro-4-(3-chloro-5-trifluoromethylpyrdin-2-yloxy)phenyl] urea, was a gift from CIBAGeigy, Inc. (Basel, Switzerland). It was identified as a suitable internal standard for assay after the initial stability studies had been performed utilizing assay2. RESULTS Solubility Determinations. The solubility of busulfan in the respective individual solvent systems are displayed in Table 3. TABLE 3______________________________________Solubility of Busulfan in Various Solvent SystemsFormulation Solubility (mg/ml)______________________________________1 1.662 3.323 3.404 2.095 3.196 4.947 2.68 3.09 3.010 75.0______________________________________ The solubility of busulfan significantly increased in all nine systems tested; ranging from 66 to 197 fold compared to the solubility in water. Therefore, the formulation of a parenteral form of busulfan at 2-4 mg/ml is feasible. At this solubility, a longer than 120 minute infusion duration should not be needed to achieve a clinically prescribed dose of 1 mg/kg body weight in heavy subjects. EXAMPLE 2 Equilibrium Solubility and Stability Studies of Parenteral Preparations of Busulfan The present example provides a design of a chemically stable formulation of busulfan that is suitable for parenteral administration, studies of limits of solubility when accordingly formulated busulfan is mixed with infusion fluids such as saline and dextrose, studies of chemical and physical stability of busulfan in the proposed parenteral preparation during the infusion period, toxicity of the solvent system in terms of hemolysis potential, and in vitro cytotoxic activity of vehicle(s) with and without the addition of busulfan. METHODOLOGY Equilibrium Solubility Studies. PEG-400 aqueous solutions of 40 and 50% (v/v), and hydroxypropylbetacyclodextrin (HBCD) aqueous solutions of 10, 25, and 45% (w/v) were prepared by mixing with distilled water at room temperature (22° C.). An excess amount of busulfan was added to each solution and the mixtures were placed on a rotating mixer (Tube Rotator™, Scientific Equipment Products, Baltimore, Md.). Samples of 1 ml were taken at various time intervals, filtered through a 0.45 μm filter (Acro LC 25 filter™ Millipore Corp. Bedford, Mass.), on a syringe filtration assembly (Nuclepore Corp. Pleasanton, Calif.), and after appropriate dilution and derivatization with sodium diethyldithiocarbamate, the busulfan concentration was determined by HPLC as described in Example 1. For the DMA/PEG-400 aqueous vehicle, a slightly modified approach had to be taken, since DMA readily dissolved the ACRO LC 25 filter. After dissolving the busulfan in DMA, the busulfan-DMA solution was mixed with 40% PEG-400/40% water and filtered through a 0.45 μm silver filter (Nuclepore Corp., Pleasanton, Calif.) fitted to a syringe assembly. After derivatization with DDTC, the busulfan concentration was determined by HPLC as above. Osmotio Pressure Measurement. Osmotic pressure measurements were carried out on an Advanced Digimatic Osmometer™ (Model 3D II, Advanced Instruments Inc., Needham Heights, Mass.). The instrument was calibrated using Osmet™ calibration standards (Precision Systems 5004, Curtin Matheson Scientific, Houston, Tex.) over a range of 100-2000 mOsm/kg. The test solution was placed in a disposable cuvette in a volume of 250 μl, and the osmotic pressure reading was recorded after equilibration in units of mOsm/kg. Triplicate measurements were carried out for each tested vehicle solution (without busulfan) and six measurements were done with busulfan added. Stability of the Various Busulfan Formulations. The physical and chemical stabilities of the various parenteral busulfan formulations were examined as follows: First, busulfan was dissolved at a concentration of 25 mg/ml in DMA only ("stock solution") and incubated at 4° C., at 22° C. and at 40° C. Starting at time zero, then weekly up to 10 weeks, samples were withdrawn and analyzed for busulfan concentration by HPLC. Second, the busulfan-DMA was diluted with PEG-400/water to give final concentrations of DMA:PEG-400:water of 20:40:40 and final busulfan concentrations of 2-10 mg/ml. These formulations were subsequently analyzed by HPLC immediately after mixing and then hourly for eight hours. Third, busulfan formulation mixtures were diluted in normal saline to a final busulfan concentration of 1 mg/ml. The preparations were then introduced into infusion bags (Viaflex™, Baxter Healthcare Corp. Deerfield, Ill.), and allowed to run through a parenteral infusion set at a rate of 1 ml/min. Samples were collected at 0, 0.5, 1.0, 2.0, 5.0, 7.0, 9.0, and 12 hours and analyzed for busulfan by HPLC as above. Hemolysis Studies. The procedure of Reed and Yalkowsky was employed for the studies of hemolytic potential of the different preparations, and the LD50 values of the various formulations were evaluated (Reed et al., 1985). Variable amounts of whole blood (citrated) were added to 0.05 ml of the drug formulations in ratios of 1:1 (v/v), 1:3, 1:5, 1:7, and 1:9. The mixtures were vortexed for 10 seconds and then incubated for 2 minutes at 25° C. Five ml normal saline was then added to this blend to quench further lysis of the erythrocytes by rendering the preparation nearly isotonic. The mixture was again vortexed for 10 seconds and centrifuged for 5 minutes at 3,000 r.p.m. (Beckman Model TJ-6 Centrifuge, Beckman Instruments Inc., Palo Alto, Calif.). The supernatant was carefully aspirated and discarded. The packed erythrocytes were washed once more at room temperature with one volume of normal saline. After centrifugation, the supernatant was again carefully aspirated and discarded. Subsequently, 1 ml of water was added for every 0.1 ml of erythrocytes used. After vortexing for 10 seconds, the mixtures were centrifuged for 5 minutes at 3,000 r.p.m. The absorbance of the supernatant was subsequently measured at 540 nm after a 1:3 dilution with distilled water. Normal saline was assayed in parallel as a standard. The fraction of healthy erythrocytes was defined as the absorbance reading of the respective drug formulation divided by that of the saline standards (Reed et al., 1985). Statistical Analysis. The osmotic pressure measurements were subjected to a two-tailed t-test to evaluate the difference between the various vehicle formulations with and without the addition of busulfan. The difference between the means of the two groups was considered significantly different for P less than or equal to 0.05 (Mann et al., 1947). In vitro Cytotoxicity of Busulfan in the DMA/PEG-400 Vehicle. Human leukemic KBM-3 cells (Anderson, et al., 1992), were incubated for 24 hours in the complete vehicle without the addition of busulfan at different concentrations (0.5%, 1.0%, 2.0%, 3.0% and 100%, v/v), to assay the cytotoxic properties of the 20% DMA/40% PEG-400 aqueous vehicle by itself (negative controls), or with the addition of busulfan. In parallel, cells in Iscove's modified Dulbecco medium (GIBCO, Grand Island, New York, N.Y.), supplemented with 10% fetal bovine serum, were incubated with busulfan (at 25 μg/ml and 50 μg/ml), in the 20% DMA/40% PEG-400 aqueous solvent (the resulting vehicle concentrations were 1.0 and 2.0% (v/v), respectively), or with busulfan dissolved in a small volume (≦1%, v/v) of acetone (positive controls). After 24 hours, 25 μl of a 5 mg/ml solution of MTT (3, [4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazoliumbromide, obtained from Sigma Chemicals, St. Louis, Mo.), was added to each sample, and after an additional 2 hours of incubation at 37° C., 100 μl of extraction buffer was added (extraction buffer: 20% (w/v) SDS dissolved to saturation at 37° C. in a solution of equal parts of dimethylformamide and deionized water; the pH was adjusted to 4.7 by the use of acetic acid and 1N HCL as described (Hansen et al., 1989). After over night incubation at 37° C. the optical densities at 570 nm were measured using a Titer-Tech 96-well multi-scanner, using the extraction buffer as the blank. The cytotoxicity was determined as the difference between the samples as above and the reactivity of cells incubated in PBS alone. All determinations were performed in triplicate. RESULTS Equilibrium Solubility Determinations. Maximum solubility of busulfan in the HBCD formulations was reached relatively rapidly with equilibrium attained within one hour at all concentrations of HBCD. An approximate equilibrium solubility of busulfan of 5.6 mg/ml was achieved in the 45% HBCD formulation, with 4.6 and 3.2 mg busulfan per ml in the 25%, and 10% HBCD formulations respectively (Table 4). TABLE 4______________________________________Busulfan Equilibrium Solubility in Various Solvent SystemsFormulation.sup.a Solubility (mg/ml)______________________________________10% HBCD (w/v) 3.1825% HBCD (w/v) 4.5745% HBCD (w/v) 5.5640% PEG-400 (v/v) 3.0150% PEG-400 (v/v) 6.1820% DMA/40% PEG-400 (v/v) >3.00______________________________________ .sup.a All formulations were made up to 100% in water The busulfan concentration in the 25% and 45% HBCD formulations declined rapidly after equilibrium, probably due to chemical degradation of busulfan in this vehicle (FIG. 2). In contrast, in PEG-400 alone, equilibrium solubility was reached slowly; its maximum was not reached for 14 hours (FIG. 3). The 40% and 50% (v/v) PEG-400 formulations yielded maximum busulfan solubility of approximately 3.0 and 6.2 mg/ml respectively (Table 4). Once the maximum solubility was reached, however, the busulfan appeared stable in these vehicles (FIG. 3). To avoid the slow initial solubilization of busulfan in PEG-400, the present inventors introduced an initial step of dissolving busulfan in anhydrous N',N-dimethylacetamide (DMA), followed by mixing it with PEG-400/aqueous solution to final concentrations of 20% DMA/40% PEG-400/40% water. Busulfan may be dissolved in DMA at 75 mg/ml, but was routinely dissolved in a "working" stock solution of 25 mg/ml. This stock solution of busulfan in DMA was stable at 4° C. and at 22° C. for more than 10 weeks without appreciable decay. At 40° C. some degradation (approximately 10-20%) was noted, starting gradually from about three weeks and at 15 weeks being in the order of 50%. The composite DMA/PEG400/agueous solvent provided a maximum transient busulfan solubility of approximately 10 mg/ml. This "complete" busulfan formulation was stable at room temperature for more than 8 hours when the busulfan concentration was ≦3 mg/ml. At higher concentrations (5-10 mg/ml), the drug started precipitating after one hour. This precipitation continued until a new apparent equilibrium solubility of about 3 mg/ml had been established (see FIG. 7). Osmotic Pressure. It is desirable to formulate a parenteral administration form that is isosmotic to human blood, but a highly hypertonic delivery system can be utilized if the drug/solvent is infused through a central vein catheter and rapidly diluted by a high blood volume. The osmolarity of the various busulfan formulations are shown in Table 5. TABLE 5______________________________________Osmotic Pressure Measurement.sup.a Osmotic Pressure,Number Formulation mOsm/kg (S.D.)______________________________________1 Water 0.002 Normal Saline 233.0 (5.00)3 Blood 290.7 (0.47)4 10% HBCD 82.33 (1.25)5 10% HBCD-busulfan 92.67 (1.97)6 45% HBCD 298.7 (9.98)7 45% HBCD-busulfan 325.5 (13.30)8 40% PEG-400 1661. (10.00)9 40% PEG-400-busulfan 1729. (5.00)10 50% PEG-400 2088. (6.53)11 50% PEG-400-busulfan 2672. (15.41)12 20% DMA/40% PEG-400 4653. (8.50)13 20% DMA/40% PEG-400- 4416. (6.20) busulfan______________________________________ .sup.a the mean from 3-6 independent determinations. The PEG-400 formulations with and without busulfan were very hypertonic; their osmotic pressures ranged from 1661 to more than 4000 mOsm/kg as compared with the 290 mOsm/kg for blood. The 10% HBCD solutions with and without busulfan were hypotonic, their osmolarity ranging from 82 to 93 mOsm/kg. The 45% HBCD solution was isosmotic compared with blood. Addition of busulfan increased the osmolarity in all the formulations studied except the 20% DMA/40% PEG aqueous solution (Table 5) (P<0.05). Physical and Chemical Stabilities of the Formulations. The physical and chemical stability of busulfan in the various solvent formulations was studied. The drug was first dissolved in DMA at 25 mg/ml. Different aliquots were stored at 4° C., at 22° C., and at 40° C. From time 0 and then weekly, samples were analyzed for busulfan concentrations by HPLC. Samples stored at 4° C. and at 22° C. had no drug degradation over at least 15 weeks of observation. When stored at 40° C., the samples showed degradation of busulfan starting around 3 weeks and at 15 weeks it amounted to about 50%. The stability of busulfan in the complete 20% DMA/40% PEG-400/40% water was also studied for the following different busulfan concentrations, 2, 3, 5, 8, and 10 mg/ml. At 2 and 3 mg/ml the busulfan was stable for the duration of the 8 hour observation period in this solvent system. At 5, 8, and 10 mg/ml, a precipitate started forming after 1-2 hours and the concentration of free busulfan gradually decreased to about 3 mg/ml, which therefore appears to be the maximum solubility at 22° C. in this vehicle (see FIG. 7). To examine the drug stability during a prolonged infusion, the busulfan was dissolved at 5 mg/ml in 40% and 50% aqueous PEG-400 and at 4 mg/ml in the 10%-HBCD. The mixtures were then filled into (clinically utilized) infusion fluid transfer bags, (300 ml Viaflex™ bags, Baxter Healthcare Corp., Deerfield, Ill.). The busulfan was subsequently evacuated through an infusion tubing set (Quest Medical Inc., Dallas, Tex.), at a rate of 1 ml/min, and samples taken for drug analysis at regular time intervals (at 0, 0.5, 1, 2, 5, 7, 9, and 12 hours). After derivatization of the busulfan as described above the samples were analyzed with HPLC. Interestingly, an initial decrease in busulfan concentration, probably from early drug adsorption to the walls of the infusion container and the tubing set was detected. Thereafter, the busulfan concentration remained constant up to at least five hours in the 10% HBCD vehicle, and for at least 7 hours in the different PEG-400 formulations. Hemolysis. The hemolytic potential of the various busulfan formulations was evaluated. The data were plotted as fraction of healthy cells versus ln(Total volume percent). Total volume percent is the volume percentage of the vehicle in the mixture after dilution with blood. This has been done in an attempt to simulate the dilution of the preparation in the body after intravenous injection. Healthy erythrocytes were defined as those capable of retaining the hemoglobin inside the cell after mixture with the respective busulfan formulations (Reed et al., 1990). As shown in FIGS. 4-6, all preparations showed similar trends of inducing hemolysis both with and without the addition of busulfan. The addition of busulfan did not add significantly to the overall hemolytic effect. The LD 50 values of the various vehicle formulations are summarized in Table 6. TABLE 6______________________________________Hemolytic LD.sub.50 Values of the Various Busulfan FormulationsFormulation LD.sub.50, (TVP.sup.a,b)______________________________________10% HBCD >610% HBCD-Busulfan >640% PEG-400 10.040% PEG-400-Busulfan 10.050% PEG-400 12.550% PEG-400-Busulfan 12.520% DMA/40% PEG-400 >3020% DMA/40% PEG-400-busulfan 15.6______________________________________ .sup.a TVP = Total Volume Percent (Reed et al., 1985). .sup.b Each determination was performed in triplicate. LD 50 was defined as the total volume percent of the vehicle mixture that is needed to produce 50% hemolysis. Overall, the HBCD preparations had very low LD 50 values when compared with the PEG formulations. It has been reported that cyclodextrins have a very high potential for inducing hemolysis (Yoshida et al., 1988), with LD 50 values of about 2% (w/v). In the present study, however, the HBCD with and without busulfan exerted a minimal hemolytic potential at the vehicle to blood ratios (1:1 to 1:9) studied. The dilution of the respective drug formulation in the actual clinical infusion will be much higher than the highest dilution (1:9) studied. Since there was insignificant hemolysis already at the 1:5 dilution, all formulations presented herein should be safe for parenteral administration. Furthermore, busulfan itself has been shown to cause hemolysis (Bishop et al., 1986); however, in the formulations studied, the contribution of busulfan to overall hemolysis was insignificant. In Vitro Cytotoxicity of Busulfan. To study the cytotoxic activity of busulfan in the 20% DMA/40% PEG-400 aqueous vehicle, human KBM-3 myeloid leukemia cells (Andersson et al., 1992), were exposed to either the complete vehicle at various concentrations without or with the addition of busulfan for 24 hours at 37° C. The cytotoxicity was assayed with the MTT assay (Hansen et al., 1989). The data show, that the complete vehicle, at high concentrations, exerted some toxicity on its own, likely due to the high osmolarity of this formulation. Busulfan dissolved in this vehicle retained its cytotoxic activity (FIG. 10), such that at 25 μg/ml about 50% of the cells were killed and at 50 μg/ml approximately 80% of the cells were killed. This paralleled the cytotoxicity seen when the cells were exposed to busulfan dissolved in a negligible volume of acetone. The cytotoxic properties of busulfan were retained when the drug was dissolved in the 20% DMA/40% PEG-400 aqueous vehicle. EXAMPLE 3 Quantitative Extraction of Busulfan from Blood Prior to HPLC, and Pharmacokinetics of i.v. Administered Busulfan The present example provides the development of an efficient technique for extraction of busulfan from blood plasma, adaptation of the HPLC assay for quantitation of busulfan in the plasma extract, and studies of the in vivo plasma pharmacokinetics of busulfan when administered orally as the commercially available tablet, as an oral solution in a vehicle of 40% PEG-400, and as an intravenous injection when dissolved in a vehicle of 40% PEG-400. A comparison of the plasma pharmacokinetics of busulfan in the rat is also given after i.v. busulfan administration. The drug was dissolved at 3 mg/ml in either acetone or DMSO or the complete 20% DMA/40% PEG-400 aqueous solvent. Quantitative Extraction of Busulfan in Blood Plasma. Rat plasma (0.2 ml) was spiked with varying concentrations of busulfan (from a stock solution in DMA), to give final drug concentrations of 0.15-3.0 μg/ml. The internal standard, 20 μl, (CGA-112913; in methanol, 20 μg/ml) was then added to the drug-plasma mixtures. After vortexing for 10 seconds, the drug and internal standard were precipitated from the plasma proteins with 0.2 ml acetonitrile with subsequent vortexing for 30 seconds. The busulfan and internal standard were then extracted using 2 ml of ethyl acetate and vortexed for i minute. The solutions were centrifuged for 10 minutes and i ml of the ethyl acetate layer was evaporated to dryness under compressed air. The busulfan and internal standard were then dissolved in 0.5 ml of distilled water and derivatized with 0.2 ml of an 8.2% (w/v) solution of diethyldithiocarbamic acid sodium and vortexed for 30 seconds. The busulfan derivative, DDCB (Diethyldithiocarbamoyl butane), was subjected to solid phase extraction with Sep-Pak LC™ cartridges (Millipore Corporation, Bedford, Ill.) under vacuum. The cartridges were conditioned with three 1-ml washes of methanol followed by two 1-ml washes with distilled water. The derivatized solutions were then passed through the cartridges and the cartridges washed twice with 1 ml 50% methanol in distilled water. The DDCB and the internal standard were eluted from the columns using 250-μl methanol twice, followed by two washes of 0.5-ml of ethyl acetate. The combined extracts were evaporated to dryness with compressed air and reconstituted with 0.2 ml of the mobile phase (acetonitrile: water: THF, 55:25:20% (v/v, pH 4.2). The reconstituted extracts were stored at 4° C. overnight and then subjected to HPLC analysis. In these experiments the assay-1 from Table 2 was used. Assay-1 provided better resolution with the acetonitrile/water/THF than that obtained with methanol/water as the mobile phase in assay-2. CGA-112913 is a suitable internal standard for assay-1. Ten μl of the stock solution of CGA-112913 in acetonitrile was added to each sample as internal standard and 40 to 60 μl of sample was injected into the HPLC for analysis. Pharmacokinetic Studies in Animals: Experimental Protocol. The pharmacokinetic studies were conducted in Sprague-Dawley rats (300-350 g) (Sasco Corp., Lincoln, Nebr.). The animals were anesthetized using intraperitoneal injections of pentobarbital sodium (50 mg/kg body weight) (Nembutal™ Sodium Solution, Abbott Laboratories, North Chicago, Ill.). The jugular veins were cannulated percutaneously from the back of the neck, and the cannulas were kept patent with heparinized saline. All animals were allowed to recover for 24 hours after cannulation before the pharmacokinetic studies were commenced. The studies were conducted to determine the plasma pharmacokinetics of busulfan after the administration of drug as: (1) The commercially available tablet (2 mg/tablet, Burroughs Welcome Pharmaceuticals, London, UK) . In the second experimental series the tablet preparation was administered to animals that had either had free access to food and water or that had been fasting for at least four hours. (2) 40% PEG400-busulfan as an oral solution. (3) 40% PEG400-busulfan administered as an i.v. injection. (4) 20% DMA/40% PEG-400/aqueous solution administered as an i.v. injection. (5) 100% acetone used as the sole solvent. (6) 100% DMSO used as the solvent; the busulfan was dissolved in DMSO immediately prior to i.v. administration, due to its propensity to rapidly degrade in this vehicle. One rat was used for each administration form. All animals were allowed free access to food and water, unless specified where the pharmacokinetics were compared in fasting and freely eating animals after administration of the busulfan tablet. The drug was given at a dose of 1 mg/kg body weight in all instances. When given orally, the tablet was crushed and the dose equivalent of 1 mg/kg was administered via an oro-gastric catheter. The oral 40%-PEG400-busulfan solution was administered to the animals similar to the tablets. The parenteral 40%-PEG400-busulfan solution and the DMA/PEG-400/aqueous solution were given i.v. through the jugular cannula. The cannula and tubing were carefully flushed with heparinized saline after the injection to prevent drug from adhering to the catheter walls and subsequently interfering with the blood sampling and pharmacokinetic analysis. After the drug administration, 0.5 ml blood samples were withdrawn at defined time intervals (at 0, 2, 5, 10, 30, 60 min, and at 2, 4, 6, and 8 hours), via the jugular catheters. The removed blood volume was replaced by an equal volume of saline. The samples were transferred to microcentrifuge tubes and immediately centrifuged at 13,000 r.p.m. for 60 sec. The plasma fraction was then aspirated and stored at -20° C. until extracted for HPLC assay. Pharmacokinetic Data Analysis. The pharmacokinetic parameters were calculated from the obtained plasma concentration vs. time profiles after administration of the respective preparations as described (Benet et al., 1985; Gibaldi et al., 1975; Nilsson et al., 1981). Thus, the elimination rate constant was obtained from the slope of the Ln (concentration) vs. time profile. The area under the concentration vs. time curve (AUC) was calculated using the linear trapezoidal rule. The following equations were used to calculate the various pharmacokinetic parameters: V=X.sub.o /C.sub.o (Eq. 1) Cl=V×K (Eq. 2) t.sub. 1/2 =0.693/K (Eq. 3 ) F=Cl×AUC/DOSE (Eq. 4 ) V=Volume of distribution X o =Dose, C o =Plasma concentration at time=0, Cl=Systemic Clearance, K=Elimination rate constant, t.sub. 1/2 =half life, F=Bioavailability, AUC=Area under the plasma concentration vs. time curve. RESULTS AND DISCUSSION HPLC Assay of Busulfan in Plasma. The retention times of DDCB and the internal standard (CGA-112913) in the HPLC assay were 7.5 and 8.4 min. respectively. The initial drug extraction from plasma with acetonitrile and ethyl acetate was essential to recover all drug from the plasma and to avoid interference from endogenous plasma (protein) components. Without this extraction, a large endogenously-derived peak completely obscured the DDCB peak. The recovery of derivatized busulfan (DDCB) with the above described technique was 98.8% with an accuracy of 8.9% and a limiting sensitivity in the linear interval of 100-150 ng/ml. A standard curve was prepared in the concentration range of 150-1,500 ng/ml and a good correlation was obtained between the (known) plasma busulfan concentration and peak height ratios (PHR); PHR=0.1623 ×(busulfan concentration)+0.751, r.sup.2 =0.98 (Eq. 5) Pharmacokinetic Studies. In the first experimental series only the plasma pharmacokinetic properties of busulfan after oral administration (tablet; non-fasting animal) and parenteral dosing (40%-PEG400-busulfan; non-fasting animal) were investigated. In the second series a complete study of the plasma pharmacokinetics of busulfan after administration of all the preparations as described above was conducted. The plasma busulfan concentrations vs. time profiles of the different preparations and routes of administration were plotted (FIGS. 8 and 9, and Tables 7 and 8). TABLE 7______________________________________Busulfan Plasma Conc. (μg/ml) AfterAdministration of 1 mg/kgTime (hr) A B C D______________________________________0.000 0.034 0.000 0.000 0.0000.083 0.074 0.158 2.552 2.4470.166 N/A 0.223 0.994 3.8580.333 0.377 0.119 0.896 3.6450.500 0.327 0.073 0.752 2.3441.000 0.369 0.041 0.509 1.8452.000 0.195 0.016 0.462 1.4895.000 0.286 0.000 0.450 0.5348.000 0.042 0.000 0.305 0.471______________________________________ Group: A = oral tablet, nonfasting B = oral tablet, fasting C = 40%PEG400-busulfan, oral solution D = 40%PEG400-busulfan, parenteral solution In FIG. 9 and Table 8, the busulfan concentration vs. time profiles and the resulting pharmacokinetic parameters resulting from 3 different formulations for i.v. administration in a murine model are shown. After in vivo administration of the busulfan dissolved in acetone or DMSO, significant hemolysis occurred, although no obviously serious adverse effect(s) were recorded. These formulations yielded comparable pharmacokinetic data to those obtained with the 20% DMA/40% PEG-400 aqueous vehicle. TABLE 8______________________________________Plasma Concentrations of Busulfan in Rats.sup.a BUSULFAN CONCENTRATIONtime (μg/ml)(hours) ACETONE DMSO DMA/PEG-400.sup.b______________________________________0.166 1.384 1.166 1.1351.000 1.120 0.937 0.9232.000 0.707 0.707 0.6405.000 0.319 0.268 0.3888.000 0.216 0.140 0.282______________________________________ .sup.a = Busulfan was administered i.v. at a dose of 1 mg/kg body weight in a total volume of 100-150 μl. .sup.b = DMA:PEG400:Water (20:40:40% v/v) All three solvent systems contained 3 mg/ml busulfan As expected, the resulting plasma concentrations were higher after parenteral administration than after oral dosing. Interestingly, the proposed vehicle for parenteral administration appears to also facilitate the intestinal absorption of busulfan when used for oral administration. Further, non-fasting animals seem to absorb more drug than fasting subjects, however this needs to be studied in a larger number of animals to exclude incidental inter-animal variation as the source for this observed alteration in bioavailability. It may suggest, however, that the low pH in the stomach contributes significantly to degradation of the busulfan prior to its absorption from the intestinal tract to the blood stream. After parenteral drug administration, the resulting peak plasma concentration of busulfan was approximately ten times higher and the AUC about five times higher than those seen after the standard tablet formulation in non-fasting animals. The higher bioavailability yielded by the parenteral administration form can be expected to parallel a higher reproducibility of systemically available drug after parenteral vs. the standard oral (tablet) formulation (Table 9 and 10). TABLE 9______________________________________Pharmacokinetic Parameters of BusulfanParameter A B C D______________________________________K (h -1) 0.275 N/A 0.166 0.268t.sub. 1/2 (hr) 2.513 N/A 4.169 2.581AUC (μg × hr/ml) 1.927 0.124 4.987 10.501C.sub.max (μg/ml) 0.377 0.223 2.552 3.858t.sub.max (min) 20.00 10.00 5.000 10.00______________________________________ A = oral tablet, nonfasting B = oral tablet, fasting C = 40%PEG400-busulfan, oral solution D = 40%PEG400-busulfan, parenteral solution TABLE 10______________________________________Pharmacokinetic Parameters of Busulfan.sup.aPARAMETER ACETONE DMSO DMA/PEG-400.sup.b______________________________________K (h -1) 0.243 0.278 0.205t 1/2 (h) 2.852 2.495 3.379AUC (μg · hr/ml) 5.605 4.706 5.421CL (ml/hr) 60.658 67.997 46.118______________________________________ .sup.a = Busulfan was administered i.v. at a dose of 1 mg/kg body weight in a total volume of 100-150 μL .sup.b = DMA:PEG400:water (20:40:40%, v/v), in all solvents there was 3 mg/ml of busulfan This clinically translates into a more predictable, and accurately reproducible cytotoxic effect as well as better control over the side effects and, therefore a higher degree of safety after busulfan-based chemotherapy. The available data emphasize the importance of introducing a reliable parenteral busulfan formulation for achievement of highly reproducible antitumor therapy with predictable cytotoxicity and maximum safety to the patient. EXAMPLE 4 Treatment of Malignancy in an Animal Using Parenterally Administered Busulfan The present example illustrates use of chemically stable parenterally administered formulations of busulfan for the treatment of malignant disease in an animal. The animal studies serve as model systems for exploring optimal administration schedule(s) for subsequent use of parenteral busulfan formulations in the clinical treatment of human neoplasms with therapy based on this parenteral preparation alone or in combination with other cytotoxic agent(s). Methodology In order to determine the proper procedures for human treatment, the following studies are carried out. 1. The dose-linearity of parenteral busulfan as compared to p.o. busulfan in the rat is first determined. 2. The second step is the establishment of chimerism and the development of graft-versus-host disease in the rat using high-dose parenteral busulfan in combination with other immunosuppressive therapy such as e.g. cyclophosphamide for conditioning, prior to allogeneic transplantation of (partially mis-) matched marrow, using syngeneic marrow transplants as the controls. The technique has been described (Santos G. W. and Tutschka P. J., 1974; Tutschka, P. J. and Santos G. W. 1975; Oaks M. K. and Cramer D. V. 1985). 3. The third step is the use of parenteral busulfan for the eradication of established experimental systemic cancer, such as leukemia in the L1210 mouse (NCI monograph, 1977) and in the Brown Norway Rat (Hagenbeek A, 1977). Hemopoietic cell rescue is provided by administering litter-mate derived (syngeneic) marrow to protect from bone marrow suppression after the parenteral busulfan therapy. This allows a detailed investigation of extramedullary dose-limiting toxicity of the parenteral formulation. Further, by using graded doses of malignant cells administered to the animals prior to delivering high-dose busulfan, the relative merits of various dose schedules can be calculated in a (semi-)quantitative fashion, to optimize administration schedule intended for clinical use. 4. Clinical phase one-two studies of parenteral busulfan for the treatment of disseminated malignant disease in man is the next step. Patients with advanced forms of lymphoma, breast cancer and leukemia are targeted. The busulfan therapy is delivered as part of combination therapy using two (or more) alkylating agents, e.g. busulfan in combination with cyclophosphamide and/or etoposide, followed by hemopoietic cell rescue with either autologous or allogeneic marrow as described using oral busulfan (Santos G. W. et al., 1983; Thomas, E. D. 1987; Copelan E. A. et al., 1987, and reviewed by Giralt and Andersson, 1993) . 5. Alternatively, using the intraarterial route of administration, regional perfusion of localized solid tumors, such as tumors that are localized to a limb, as well as those that are confined to a well defined area of a visceral organ such as the liver, can now be accomplished using busulfan. Although this technique itself is not new (Stehlin et al., 1975; McBride, C. M., et al., 1975; Schraffordt K., et al., 1977), the employment of busulfan in this treatment modality has been hampered by the lack of a busulfan formulation that could be safely administered and which retains its cytotoxic activity throughout the period of treatment. Such investigations have to be performed as clinical phase one-two studies, since there is no appropriate animal model of regional therapy. Due to the expected low-to moderate systemic side effects of such therapy, the need for hemopoietic support would be limited to (at most) the administration of recombinant hemopoietic growth factor(s), possibly in addition to blood products. This is in contrast to the above outlined studies (2-4) which would necessitate administration of marrow and/or peripheral blood progenitor cells, to ensure rapid hemopoietic reconstitution. A dose range for parenteral administration of busulfan for an animal such as a rat may be from 15 to 50 mg/kg with or without cyclophosphamide. The dose may be administered as a bolus or divided into three portions. A method of treatment of an individual using busulfan as a chemotherapeutic agent may involve intra-arterial or intravenous administration at a dose range of 5-20 mg/kg body weight every 6-12 hours for 3-5 days. A phase I study may include the administration of 10 mg/kg divided in 8 equal doses spaced 12 hours apart, each dose lasting 4 hours. The following references are incorporated in pertinent part by reference herein for the reasons cited above. REFERENCES Abe T.: 1975, Jpn J. Clin. Hematol. 16:839-849. Albrecht M. et al., 1971, Med. Klin., 66 (4): 126-130. Ambs V. E. et al., 1971, Arch. Kinderheilk 182:218-239. Andersson B. S., et al., 1992, Exp. Hematol., 20:361-367. Bhagwatwar, H., et al., 1993, Abstract for American Association for Cancer Research, May 19-23, 1993 Benet L. Z., and Sheiner L. B., Pharmacokinetics: The dynamics of drug absorption, distribution, and elimination. In: The pharmacological basis of therapeutics.: 1985 Goodman et al. (Eds.) 7th Ed., MacMillan Publishing Company Inc. New York, N.Y., pp. 3-34. Bishop J. B. and Wassom J. S., 1986, Mutation Res. 168:15-45. Blume K. G. and Forman S. J., 1987, Blut 55:49-53. Buckner C. D. et al., 1992, Blood 80:277 (Abstr.). Buckner C. D. et al., 1975, Scand J. Hematol. 3:275-288. Canellos G. P., Chronic Leukemias. In: Cancer: Principles and Practice of Oncology, 2nd Edition. 1985, DeVita V. T. Jr. et al., (Eds.). J. B. Lippincott Co. Philadelphia, Pa. pp. 1739-1752. Champlin R. C. et al., 1985, Transplant. Proc. 17:496-499. Collis C. H., 1980, Cancer Chemother. Pharmacol. 4:17-27. Copelan E. A. et al., 1989, Br. J. Haematol. 71:487-491. Galton D. A. G., 1953, Lancet 1:208-213. Ganda O. P. and Mangalik A., 1973, J. Assoc. Physcns. India, 21 (6): 511-516. Geller R. B. et al., 1989, Blood, 73:2209-2218. Gibaldi M. and Perrier E. D., 1975, Pharmacokinetics. Marcel Dekker Publishers, New York, N.Y. Giles, A. R., et al., 1984, Br. J. Haematol., 57:17-23 Abstract Giralt S. and Andersson B. S., 1993, Oncology, InPress. Grigg A. P. et al., 1989, Ann. Intern. Med. 111:1049-1050. Grochow L. B. et al., 1989, Cancer Chemother. Pharmacol. 25:55-61. Haddow A. and Timmis G. M., 1953, Lancet 1:207-208. Hagenbeek A., 1977, Leuk. Res., 1:85-90. Hagenbeek A. et al., 1977, Leukemia Research 1:99-101. Hansen M. B., et al., 1989, J. Immunol. Methods, 119:203-210. Hassan, M., et al., 1992, Cancer Chemotherapy and Pharmacology, 30:81-85. Hughes T. P. and Goldman J. M., Chronic myeloid leukemia. In: Hematology, Basic principles and practice. 1991, Hoffman R. et al., Churchhill Livingstone Inc., New York, N.Y. pp. 854-869. Keating M. J. et al., 1993, Leukemia and Lymphoma, In Press. Kitamura, Y., et al., 1979, Jpn. J. Anesthesiol. 28: 512-517 Abstract Koch H., and Lesch R., 1976, Med. Welt, 27(7):308-311. Lu C. et al., 1984, Cancer Treatm. Repts. 68:711-717. McBride C. M. et al., 1975, Ann Surg. 182:316-324. MacKicham J. J. and Bechtel T. P., 1990, J. Chromatography, 532:424-428. Mann H. B. and Whitney D. R., 1947, Ann. Math. Statist. 18:50-60. Marcus R. E. and Goldman J. M., 1984, Lancet II (8417-18) 1463. Martell R. W. et al., 1987, Ann. Intern. Med. 106:173. Merck Index, 11th Ed., 1989, Budaveri, S., et al., eds. Propyleneglycol, p. 7870, Merck & Co., Inc., Rahway, N.J. Miller C. et al., 1991, Blood 78:1155 (Abstr.). National Cancer Institute Monograph 45, 1977, USA-USSR Monograph, Methods of Development of New Anticancer Drugs DHEW Publication No. (NIH) 76-1037:147-153. Nilsson S. O. et al., 1981, Cancer Chemother. Pharmacol. 5:261-266. Oakhill A. et al., 1981, J. Clin. Pathol. 34(5):495-500. Oaks M. K. and Cramer D. V., 1985, Transplantation 39:69-76. Peters W. P. et al., 1987, Cancer Res., 47:6402-6404. Reed K. W. and Yalkowsky S. H., 1985, J. Parenteral Sci. Techn. 39(2):64-68. Sanders J. E. et al., 1988, Bone Marrow Transplantation 3:11-19. Santos G. W. et al., 1983, N. Engl. J. Med. 309:1347-1353. Santos G. W. and Tutschka, P. J., 1974, J. Natl. Cancer Inst. 53:1781-1785. Schraffordt K. H. et al., 1977, Cancer 39:27-33. Schwertfeger R. et al., 1992, Blood 80:2125 (Abstr.). Sharkis, S. J. and Santos, G. W., 1977, Leukemia Research 251-252. Sheridan W. P. et al., 1989, Med. J. of Australia 151:379-386. Stehlin J. S. et al., 1975, Surg. Gynecol. Obstet. 140:339-348. Sureda A. et al., 1989, Ann. Intern. Med. 111:543-544. Thomas E. D., 1987, American H of The Medical Sciences 294:75-79. Tutschka P. J. et al., 1987, Blood, 70:1382-1388. Tutschka P. J. and Santos G. W., 1975, Transplantation 20:101-106. Vassal G. et al., 1990, Cancer Res. 50:6203-6207. Vaughn W. P. et al., 1991, Bone Marrow Transplantation 8:489-496. Weiss A. J. et al., 1962, Cancer Chemotherapy Rep. 16:477-485. Yeager A. M. et al., 1986, New Engl. J. Med. 315:141-147. Yoshida A. et al., 1988, Int. J. Pharmaceutics, 46:217-222. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.

Stable parenteral formulations of busulfan for parenteral administration are disclosed. The improved bioavailability of the parenteral formulations optimizes high dose busulfan therapy against malignant disease and improves the safety of such therapy.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to feeding of a recording medium in printers. More specifically, the present invention relates to control of line feeding of a recording medium in conjunction with print head nozzle firing so as to advance the recording medium for high resolution printing with a lower amount of line feeding motor steps. 2. Description of the Related Art Line feeding in printers refers to the advancement of a recording medium through the printer during printing operations. During printing operations, the recording medium is fed through the printer by line feed rollers that are driven by a line feed motor controlled by a controller. The line feed motor and the line feed rollers are connected by a drivetrain so that as the line feed motor rotates, the line feed rollers also rotate. The recording medium is fed between the line feed rollers and pinch rollers and as the line feed rollers rotate, the recording medium is fed through the printer. One type of line feed motor is known as a stepper motor. A stepper motor rotates in steps, i.e. stepped increments or pulses. Each increment or pulse corresponds to a predetermined amount (or phase) of rotation. Some of the most common stepper motors used in printers have stepped increments of 1.8° (corresponding to a 200 pulse motor where 200 pulses×1.8°=360°), 3.6° (corresponding to a 100 pulse motor), and 3.75° (corresponding to a 96 pulse motor). For each increment (pulse) that the line feed motor rotates, the line feed rollers also rotate and feed the recording medium a horizontal amount corresponding to the amount of rotation of the line feed rollers. The amount of rotation of the line feed rollers is determined by the drivetrain ratio employed between the line feed motor and the line feed rollers. Conventionally, the drivetrain ratio has been set so that one pulse of the line feed motor advances the recording medium an amount equivalent to the maximum resolution of the printer. For example, where the maximum resolution of a printout of the printer is 600 dpi (dots per inch), the drivetrain ratio has been set so that one pulse of the line feed motor corresponds to a 600 dpi pitch line feed of the recording medium. Thus, the line feed ratio to obtain a 600 dpi resolution printout would be 1/600 (1 pulse equals 600 dpi advancement of the recording medium). In order to obtain higher resolution printouts, such as a 1200 dpi printout, additional motor pulses are required. Consider, for example, a print head having 100 nozzles spaced at a 600 dpi pitch printing a 1200 dpi image. The print head performs two scans across the same scan area to perform 1200 dpi printing (a first scan printing at 600 dpi and a second scan also printing at 600 dpi after a 1200 dpi paper advancement). After the second scan, the paper is advanced to the end of the 100 nozzle printout. In order to advance the paper to the end of the 100 nozzle print, 200 pulses of the motor would be required (it takes 2 pulses to advance the paper one 600 dpi pixel, therefore it takes 200 pulses to advance the paper 100 pixels). The 200 pulses result in a slower line feed speed than would otherwise be required if less motor pulses were needed to advance the paper the same 100 pixel amount. Thus, what is needed is a way to increase the line feed speed at higher resolutions. It has been proposed that, to increase the line feed speed, that the motor speed itself could be increased. However, higher resolution printouts also require a higher degree of accuracy of the motor. Faster and more accurate motors are expensive and increase the cost of the printer. Therefore, what is needed is a way to increase the line feed speed at higher resolutions and to maintain accuracy without a significant increase in the motor cost. SUMMARY OF THE INVENTION The present invention addresses the foregoing by feeding the recording medium a fractional amount greater than the maximum resolution of the printer for each increment (phase) of the line feed motor and controlling a number of nozzles that eject ink based on the number of increments. In one representative embodiment, each increment of the line feed motor results in a 1.5 pixel advancement of the recording medium in a pixel resolution of a print head. A comparison of this embodiment to the above described example in which a 1/600 feeding ratio results, the present invention results in a 1/400 feeding ratio for the same motor. Therefore, less line feed motor increments are required to advance the recording medium an equivalent amount. Since less motor increments are required, the line feed speed is increased. Moreover, controlling the nozzle firing provides for adjustment of the nozzle firing for the fractional increments, thereby providing for printing a continuous image. Thus, in one aspect the invention is printing images on a recording medium fed through a printer by actuating a line feeding motor in predetermined stepped increments, feeding the recording medium through the printer by a line feeding device driven by the line feeding motor, printing an image on the recording medium by a print head scanning across the recording medium and ejecting ink from nozzles, the print head having j nozzles spaced at a predetermined pixel resolution that is less than a pixel resolution printed by the printer, j being an integer number, controlling the line feed motor to actuate in stepped increments, and controlling a number of the j nozzles utilized in printing the image. For each stepped increment of the line feed motor, the line feeding device feeds the recording medium (m×1/n) pixels of the print head pixel resolution, where m and n are integer numbers and m is greater than n. The j nozzles that print in any one scan of the print head are controlled based on the number of increments of the line feed motor. In a related aspect, the invention is feeding a recording medium through a printer for printing images on the recording medium by actuating a line feeding motor in stepped increments, feeding the recording medium through the printer by a line feeding device driven by the line feeding motor, and performing banded printing of an image on the recording medium by a print head scanning across the recording medium, the print head having nozzles spaced at a first resolution. One increment of the line feeding motor results in a feed amount of m/n times the print head nozzle spacing, where m/n is greater than 1, and m and n are integer values where m is greater than n, and, to print the image, the line feeding motor is actuated n increments, or an integer multiple of n increments between bands. In other aspects, m may be equal to 3 and n equal to 2. The number of increments of the line feed motor may equal 2 so that every 2 increments equals a line feed of 3 pixels in the pixel resolution printed by the printer. The number of nozzles, j, may equal 304 or 80, and 300 or less, or 78 or less nozzles may be utilized to print in any one scan of the print head. The j nozzles may be spaced at a 600 dpi resolution and the printed resolution of the printer may be 1200 dpi. In another aspect, the invention processes image data to be sent to a printer by performing rasterization, color conversion and halftone processing on the image data, storing the processed image data in a print buffer for transmission to the printer, calculating a line skip amount, calculating a buffer offset amount, and adjusting a starting position for storing of the image data in the print buffer based on a result of the calculated buffer offset amount. The line skip amount and the buffer offset amount are calculated in a case where a first line of image data to be stored in the print buffer is white data. Additionally, the printer has a line feed ratio of m×1/n in a pixel resolution of a print head, where m and n are integer numbers greater than 1, m is greater than n, and the line skip amount and the buffer offset amount are calculated based on the line feed ratio. In a related aspect, the invention processes image data to be sent to a printer that prints image data on a recording medium at a print pixel resolution greater than a resolution of a print head and feeds the recording medium in units of a feed amount corresponding to (m×1/n) pixels of the print head resolution, where m and n are integer numbers and m is greater than n, the image process comprising generating a line of image data, determining whether at least a number of contiguous lines of image data do not include a pixel to be printed, the number of contiguous lines corresponding to the feed amount unit, and sending line skip amount information to the printer based on a result of the determining step. The determining, step comprises storing the line of image data in a print buffer for transmission to the printer, and calculating the line skip amount. The determining step may further comprise calculating a buffer offset amount, and adjusting a starting position for storing the image data in the print buffer based on a result of the calculated buffer offset amount. The skip amount and the buffer offset amount are calculated in a case where a first line of image data to be stored in the print buffer is white data. As a result of the foregoing, the invention controls a line feed amount and loading of image data in a print buffer to adjust for white image data encountered as at least the first line of the image data being loaded in the buffer. Therefore, the line feed ratio and line feed amount for advancing the recording medium to adjust for the white space is accommodated to provide for a faster line feed speed while at the same time controlling the data loading. This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiment thereof in connection with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view of computing equipment used in connection with the printer of the present invention. FIG. 2 is a front perspective view of the printer shown in FIG. 1 . FIG. 3 is a back perspective view of the printer shown in FIG. 1 . FIG. 4 is a back, cut-away perspective view of the printer shown in FIG. 1 . FIG. 5 is a front, cut-away perspective view of the printer shown in FIG. 1 . FIGS. 6A and 6B show a geartrain configuration for an automatic sheet feeder of the printer shown in FIG. 1 . FIG. 7 is a cross-section view through a print cartridge and ink tank of the printer of FIG. 1 . FIG. 8 is a plan view of a print head and nozzle configuration of the print cartridge of FIG. 7 . FIG. 9 is a block diagram showing the hardware configuration of a host processor interfaced to the printer of the present invention. FIG. 10 shows a functional block diagram of the host processor and printer shown in FIG. 8 . FIG. 11 is a block diagram showing the internal configuration of the gate array shown in FIG. 9 . FIG. 12 shows the memory architecture of the printer of the present invention. FIG. 13 is a side view of one possible line feed geartrain. FIG. 14 is a top view of one possible line feed geartrain. FIG. 15 is a diagram for calculating a line feed amount and paper velocity utilizing the geartrain of FIGS. 13 and 14. FIG. 16A depicts a sample pattern of ink droplets printed at a 600×600 dpi resolution. FIG. 16B depicts a sample pattern of ink droplets printed at a 600×600 dpi resolution. FIGS. 16C and 16D depict a print head nozzle location in a line feed direction for each pulse of a line feed motor. FIG. 17 is a flowchart depicting process steps of a first embodiment for controlling line feed and buffer loading for printing involving white space. FIG. 18 is a flowchart depicting process steps of a second embodiment for controlling line feed and buffer loading for printing involving white space. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing the outward appearance of computing equipment used in connection with the invention described herein. Computing equipment 1 includes host processor 2 . Host processor 2 comprises a personal computer (hereinafter “PC”), preferably an IBM PC-compatible computer having a windowing environment, such as Microsoft® Windows95. Provided with computing equipment 1 are display 4 comprising a color monitor or the like, keyboard 5 for entering text data and user commands, and pointing device 6 . Pointing device 6 preferably comprises a mouse for pointing and for manipulating objects displayed on display 4 . Computing equipment 1 includes a computer-readable memory medium, such as fixed computer disk 8 , and floppy disk interface 9 . Floppy disk interface 9 provides a means whereby computing equipment 1 can access information, such as data, application programs, etc., stored on floppy disks. A similar CD-ROM interface (not shown) may be provided with computing equipment 1 , through which computing equipment 1 can access information stored on CD-ROMs. Disk 8 stores, among other things, application programs by which host processor 2 generates files, manipulates and stores those files on disk 8 , presents data in those files to an operator via display 4 , and prints data in those files via printer 10 . Disk 8 also stores an operating system which, as noted above, is preferably a windowing operating system such as Windows95. Device drivers are also stored in disk 8 . At least one of the device drivers comprises a printer driver which provides a software interface to firmware in printer 10 . Data exchange between host processor 2 and printer 10 is described in more detail below. FIGS. 2 and 3 show perspective front and back views, respectively, of printer 10 . As shown in FIGS. 2 and 3, printer 10 includes housing 11 , access door 12 , automatic feeder 14 , automatic feed adjuster 16 , media eject port 20 , ejection tray 21 , power source 27 , power cord connector 29 , parallel port connector 30 and universal serial bus (USB) connector 33 . Housing 11 houses the internal workings of printer 10 , including a print engine which controls the printing operations to print images onto recording media. Included on housing 11 is access door 12 . Access door 12 is manually openable and closeable so as to permit a user to access the internal workings of printer 10 and, in particular, to access ink tanks installed in printer 10 so as to allow the user to change or replace the ink tanks as needed. Access door 12 also includes indicator light 23 , power on/off button 26 and resume button 24 . Indicator light 23 may be an LED that lights up to provide an indication of the status of the printer, i.e. powered on, a print operation in process (blinking), or a failure indication. Power on/off button 26 may be utilized to turn the printer on and off and resume button 24 may be utilized to reset an operation of the printer. As shown in FIGS. 2 and 3, automatic feeder 14 is also included on housing 11 of printer 10 . Automatic feeder 14 defines a media feed portion of printer 10 . That is, automatic feeder 14 stores recording media onto which printer 10 prints images. In this regard, printer 10 is able to print images on a variety of types of recording media. These types include, but are not limited to, plain paper, high resolution paper, transparencies, glossy paper, glossy film, back print film, fabric sheets, T-shirt transfers, bubble jet paper, greeting cards, brochure paper, banner paper, thick paper, etc. During printing, individual sheets which are stacked within automatic feeder 14 are fed from automatic feeder 14 through printer 10 . Automatic feeder 14 includes automatic feed adjuster 16 . Automatic feed adjuster 16 is laterally movable to accommodate different media sizes within automatic feeder 14 . These sizes include, but are not limited to, letter, legal, A4, B5 and envelope. Custom-sized recording media can also be used with printer 10 . Automatic feeder 14 also includes backing 31 , which is extendible to support recording media held in automatic feeder 14 . When not in use, backing 31 is stored within a slot in automatic feeder 14 , as shown in FIG. 2 . As noted above, media are fed through printer 10 and ejected from eject port 20 into ejection tray 21 . Ejection tray 21 extends outwardly from housing 11 as shown in FIG. 2 and, provides a receptacle for the recording media upon ejection for printer 10 . When not in use, ejection tray 21 may be stored within printer 10 . Power cord connector 29 is utilized to connect printer 10 to an external AC power source. Power supply 27 is used to convert AC power from the external power source, and to supply the converted power to printer 10 . Parallel port 30 connects printer 10 to host processor 2 . Parallel port 30 preferably comprises an IEEE-1284 bi-directional port, over which data and commands are transmitted, between printer 10 and host processor 2 . Alternatively, data and commands can be transmitted to printer 10 through USB port 33 . FIGS. 4 and 5 show back and front cut-away perspective views, respectively, of printer 10 . As shown in FIG. 4, printer 10 includes an automatic sheet feed assembly (ASF) that comprises automatic sheet feeder 14 , ASF rollers 32 a , 32 b and 32 c attached to ASF shaft 38 for feeding media from automatic feeder 14 . ASF shaft 38 is driven by drive train assembly 42 . Drive train assembly 42 is made up of a series of gears that are connected to and driven by ASF motor 41 . Drive train assembly 42 is described in more detail below with reference to FIGS. 6A and 6B. ASF motor 41 is preferably a stepper motor that rotates in stepped increments (pulses). Utilization of a stepper motor provides the ability for a controller incorporated in circuit board 35 to count the number of steps the motor rotates each time the ASF is actuated. As such, the position of the ASF rollers at any instant can be determined by the controller. ASF shaft 38 also includes an ASF initialization sensor tab 37 a . When the ASF shaft is positioned at a home position (initialization position), tab 37 a is positioned between ASF initialization sensors 37 b . Sensors 37 b are light beam sensors, where one is a transmitter and the other a receiver such that when tab 37 a is positioned between sensors 37 b , tab 37 a breaks continuity of the light beam, thereby indicating that the ASF is at the home position. Also shown in FIG. 4 is a page edge (PE) detector lever 58 a and PE sensors 58 b . PE sensors 58 b are similar to ASF initialization sensors 37 b . That is, they are light beam sensors. PE lever 58 a is pivotally mounted and is actuated by a sheet of the recording medium being fed through the printer 10 . When no recording medium is being fed through printer 10 , lever 58 a is at a home position and breaks continuity of the light beam between sensors 58 b . As a sheet of the recording medium begins to be fed through the printer by the ASF rollers, the leading edge of the recording medium engages PE lever 58 a pivotally moving the lever to allow continuity of the light beam to be established between sensors 58 b . Lever 58 a remains in this position while the recording medium is being fed through printer 10 until the trailing edge of the recording medium reaches PE lever 58 a , thereby disengaging lever 58 a from the recording medium and allowing lever 58 a to return to its home position to break the light beam. The PE sensor is utilized in this manner to sense when a page of the recording medium is being fed through the printer and the sensors provide feedback of such to a controller on circuit board 35 . ASF gear train assembly 42 may appear as shown in FIGS. 6A and 6B. As shown in FIG. 6A, gear train assembly 42 comprises gears 42 a , 42 b and 42 c . Gear 42 b is attached to the end of ASF shaft 38 and turns the shaft when ASF motor 41 is engaged. Gear 42 a engages gear 42 b and includes a cam 42 d that engages an ASF tray detent arm 42 e of automatic feeder 14 . As shown in FIG. 6A, when ASF shaft 38 is positioned at the home position, cam 42 d presses against detent arm 42 e . Automatic feeder 14 includes a pivotally mounted plate 50 that is biased by spring 48 so that when cam 42 d engages detent arm 42 e , automatic feeder 14 is depressed and when cam 42 d disengages detent arm 42 e (such as that shown in FIG. 6 B), plate 50 is released. Depressing detent arm 42 e causes the recording media stacked in automatic feeder 14 to move away from ASF rollers 32 a , 32 b and 32 c and releasing detent arm 42 e allows the recording to move close to the rollers so that the rollers can engage the recording medium when the ASF motor is engaged. Returning to FIG. 4, printer 10 includes line feed motor 34 that is utilized for feeding the recording medium through printer 10 during printing operations. Line feed motor 34 drives line feed shaft 36 , which includes line feed pinch rollers 36 a , via line feed geartrain 40 . The geartrain ratio for line feed geartrain 40 is set to advance the recording medium a set amount for each pulse of line feed motor 34 . The ratio may be set so that one pulse of line feed motor 34 results in a line feed amount of the recording medium equal to a one pixel resolution advancement of the recording medium. That is, if one pixel resolution of the printout of printer 10 is 600 dpi (dots per inch), the geartrain ratio may be set so that one pulse of line feed motor 34 results in a 600 dpi advancement of the recording medium. Alternatively, the ratio may be set so that each pulse of the motor results in a line feed amount that is equal to a fractional portion of one pixel resolution rather than being a one-to-one ratio. Line feed motor 34 preferably comprises a 200-step, 2 phase pulse motor and is controlled in response to signal commands received from circuit board 35 of course, line feed motor 34 is not limited to a 200-step 2 phase pulse motor and any other type of line feed motor could be employed, including a DC motor with an encoder. As shown in FIG. 5, printer 10 is a single cartridge printer which prints images using dual print heads, one having nozzles for printing black ink and the other having nozzles for printing cyan, magenta and yellow inks. Specifically, carriage 45 holds cartridge 28 that preferably accommodates ink tanks 43 a , 43 b , 43 c and 43 d , each containing a different colored ink. A more detailed description of cartridge 28 and ink tanks 43 a to 43 d is provided below with regard to FIG. 7 . Carriage 45 is driven by carriage motor 39 in response to signal commands received from circuit board 35 . Specifically, carriage motor 39 controls the motion of belt 25 , which in turn provides for horizontal translation of carriage 45 along carriage guide shaft 51 . In this regard, carriage motor 39 provides for bi-directional motion of belt 25 , and thus of carriage 45 . By virtue of this feature, printer 10 is able to perform bi-directional printing, i.e. print images from both left to right and right to left. Printer 10 preferably includes recording medium cockling ribs 59 . Ribs 59 induce a desired cockling pattern into the recording medium which the printer can compensate for by adjusting the firing frequency of the print head nozzles. Ribs 59 are spaced a set distance apart, depending upon the desired cockling shape. The distance between ribs 59 may be based on motor pulses of carriage motor 39 . That is, ribs 59 may be positioned according to how many motor pulses of carriage motor 39 it takes for the print head to reach the location. For example, ribs 59 may be spaced in 132 pulse increments. Printer 10 also preferably includes pre-fire receptacle areas 44 a , 44 b and 44 c , wiper blade 46 , and print head caps 47 a and 47 b . Receptacles 44 a and 44 b are located at a home position of carriage 45 and receptacle 44 c is located outside of a printable area and opposite the home position. At desired times during printing operations, a print head pre-fire operation may be performed to eject a small amount of ink from the print heads into receptacles 44 a , 44 b and 44 c . Wiper blade 46 is actuated to move with a forward and backward motion relative to the printer. When carriage 45 is moved to its home position, wiper blade 46 is actuated to move forward and aft so as to traverse across each of the print heads of cartridge 28 , thereby wiping excess ink from the print heads. Print head caps 47 a and 47 b are actuated in a relative up and down motion to engage and disengage the print heads when carriage 45 is at its home position. Caps 47 a and 47 b are actuated by ASF motor 41 via a geartrain (not shown). Caps 47 a and 47 b are connected to a rotary pump 52 via tubes (not shown). Pump 52 is connected to line feed shaft 36 via a geartrain (not shown) and is actuated by running line feed motor 34 in a reverse direction. When caps 47 a and 47 b are actuated to engage the print heads, they form an airtight seal such that suction applied by pump 52 through the tubes and caps 47 a and 47 b sucks ink from the print head nozzles through the tubes and into a waste ink container (not shown). Caps 47 a and 47 b also protect the nozzles of the print heads from dust, dirt and debris. FIG. 7 is a cross section view through one of the ink tanks installed in cartridge 28 . Ink cartridge 28 includes cartridge housing 55 , print heads 56 a and 56 b , and ink tanks 43 a , 43 b , 43 c and 43 d . Cartridge body 28 accommodates ink tanks 43 a to 43 d and includes ink flow paths for feeding ink from each of the ink tanks to either of print heads 56 a or 56 b . Ink tanks 43 a to 43 d are removable from cartridge 28 and store ink used by printer 10 to print images. Specifically, ink tanks 43 a to 43 d are inserted within cartridge 28 and can be removed by actuating retention tabs 53 a to 53 d , respectively. Ink tanks 43 a to 43 d can store color (e.g., cyan, magenta and yellow) ink and/or black ink. The structure of ink tanks 43 a to 43 b may be similar to that described in U.S. Pat. No. 5,509,140, or may be any other type of ink tank that can be installed in cartridge 28 to supply ink to print heads 56 a and 56 b. FIG. 8 depicts a nozzle configuration for each of print heads 56 a and 56 b . In FIG. 8, print head 56 a is for printing black ink and print head 56 b is for printing color ink. Print head 56 a preferably includes 304 nozzles at a 600 dpi pitch spacing. Print head 56 b preferably includes 80 nozzles at a 600 dpi pitch for printing cyan ink, 80 nozzles at a 600 dpi pitch for printing magenta ink, and 80 nozzles at a 600 dpi pitch for printing yellow ink. An empty space is provided between each set of nozzles in print head 56 b corresponding to 16 nozzles spaced at a 600 dpi pitch. Each of print heads 56 a and 56 b eject ink based on commands received from a controller on circuit board 35 . FIG. 9 is a block diagram showing the internal structures of host processor 2 and printer 10 . In FIG. 9, host processor 2 includes a central processing unit 70 such as a programmable microprocessor interfaced to computer bus 71 . Also coupled to computer bus 71 are display interface 72 for interfacing to display 4 , printer interface 74 for interfacing to printer 10 through bi-directional communication line 76 , floppy disk interface 9 for interfacing to floppy disk 77 , keyboard interface 79 for interfacing to keyboard 5 , and pointing device interface 80 for interfacing to pointing device 6 . Disk 8 includes an operating system section for storing operating system 81 , an applications section for storing applications 82 , and a printer driver section for storing printer driver 84 . A random access main memory (hereinafter “RAM”) 86 interfaces to computer bus 71 to provide CPU 70 with access to memory storage. In particular, when executing stored application program instruction sequences such as those associated with application programs stored in applications section 82 of disk 8 , CPU 70 loads those application instruction sequences from disk 8 (or other storage media such as media accessed via a network or floppy disk interface 9 ) into random access memory (hereinafter “RAM”) 86 and executes those stored program instruction sequences out of RAM 86 . RAM 86 provides for a print data buffer used by printer driver 84 . It should also be recognized that standard disk-swapping techniques available under the windowing operating system allow segments of memory, including the aforementioned print data buffer, to be swapped on and off of disk 8 . Read only memory (hereinafter “ROM”) 87 in host processor 2 stores invariant instruction sequences, such as start-up instruction sequences or basic input/output operating system (BIOS) sequences for operation of keyboard 5 . As shown in FIG. 9, and as previously mentioned, disk 8 stores program instruction sequences for a windowing operating system and fore various application programs such as graphics application programs, drawing application programs, desktop publishing application programs, and the like. In addition, disk 8 also stores color image files such as might be displayed by display 4 or printed by printer 10 under control of a designated application program. Disk 8 also stores a color monitor driver in other drivers section 89 which controls how multi-level RGB color primary values are provided to display interface 72 . Printer driver 84 controls printer 10 for both black and color printing and supplies print data for print out according to the configuration of printer 10 . Print data is transferred to printer 10 , and control signals are exchanged between host processor 2 and printer 10 , through printer interface 74 connected to line 76 under control of printer driver 84 . Printer interface 74 and line 76 may be, for example an IEEE 1284 parallel port and cable or a universal serial bus port and cable. Other device drivers are also stored on disk 8 , for providing appropriate signals to various devices, such as network devices, facsimile devices, and the like, connected to host processor 2 . Ordinarily, application programs and drivers stored on disk 8 first need to be installed by the user onto disk 8 from other computer-readable media on which those programs and drivers are initially stored. For example, it is customary for a user to purchase a floppy disk, or other computer-readable media such as CD-ROM, on which a copy of a printer driver is stored. The user would then install the printer driver onto disk 8 through well-known techniques by which the printer driver is copied onto disk 8 . At the same time, it is also possible for the user, via a modem interface (not shown) or via a network (not shown), to download a printer driver, such as by downloading from a file server or from a computerized bulletin board. Referring again to FIG. 9, printer 10 includes a circuit board 35 which essentially contain two sections, controller 100 and print engine 101 . Controller 100 includes CPU 91 such as an 8-bit or a 16-bit microprocessor including programmable timer and interrupt controller, ROM 92 , control logic 94 , and I/O ports unit 96 connected to bus 97 . Also connected to control logic 94 is RAM 99 . Control logic 94 includes controllers for line feed motor 34 , for print image buffer storage in RAM 99 , for heat pulse generation, and for head data. Control logic 94 also provides control signals for nozzles in print heads 56 a and 56 b of print engine 101 , carriage motor 39 , ASF motor 41 , line feed motor 34 , and print data for print heads 56 a and 56 b . EEPROM 102 is connected to I/O ports unit 96 to provide non-volatile memory for printer information and also stores parameters that identify the printer, the driver, the print heads, the status of ink in the cartridges, etc., which are sent to printer driver 84 of host processor 2 to inform host processor 2 of the operational parameters of printer 10 . I/O ports unit 96 is coupled to print engine 101 in which a pair of print heads 56 a and 56 b perform recording on a recording medium by scanning across the recording medium while printing using print data from a print buffer in RAM 99 . Control logic 94 is also coupled to printer interface 74 of host processor 2 via communication line 76 for exchange of control signals and to receive print data and print data addresses. ROM 92 stores font data, program instruction sequences used to control printer 10 , and other invariant data for printer operation. RAM 99 stores print data in a print buffer defined by printer driver 84 for print heads 56 a and 56 b and other information for printer operation. Sensors, generally indicated as 103 , are arranged in print engine 101 to detect printer status and to measure temperature and other quantities that affect printing. A photo sensor (e.g., an automatic alignment sensor) measures print density and dot locations for automatic alignment. Sensors 103 are also arranged in print engine 101 to detect other conditions such as the open or closed status of access door 12 , presence of recording media, etc. In addition, diode sensors, including a thermistor, are located in print heads 56 a and 56 b to measure print head temperature, which is transmitted to I/O ports unit 96 . I/O ports unit 96 also receives input from switches 104 such as power button 26 and resume button 24 and delivers control signals to LEDs 105 to light indicator light 23 , to line feed motor 34 , ASF motor 41 and carriage motor 39 through line feed motor driver 34 a , ASF motor driver 41 a and carriage motor driver 39 a , respectively. Although FIG. 9 shows individual components of printer 10 as separate and distinct from one another, it is preferable that some of the components be combined. For example, control logic 94 may be combined with I/O ports 96 in an ASIC to simplify interconnections for the functions of printer 10 . FIG. 10 shows a high-level functional block diagram that illustrates the interaction between host processor 2 and printer 10 . As illustrated in FIG. 10, when a print instruction is issued from image processing application program 82 a stored in application section 82 of disk 8 , operating system 81 issues graphics device interface calls to printer driver 84 . Printer driver 84 responds by generating print data corresponding to the print instruction and stores the print data in print data store 107 . Print data store 107 may reside in RAM 86 or in disk 8 , or through disk swapping operations of operating system 81 may initially be stored in RAM 86 and swapped in and out of disk 8 . Thereafter, printer driver 84 obtains print data from print data store 107 and transmits the print data through printer interface 74 , to bi-directional communication line 76 , and to print buffer 109 through printer control 110 . Print buffer 109 resides in RAM 99 , and printer control 110 resides in firmware implemented through control logic 94 and CPU 91 of FIG. 9 . Printer control 110 processes the print data in print buffer 109 responsive to commands received from host processor 2 and performs printing tasks under control of instructions stored in ROM 92 (see FIG. 9) to provide appropriate print head and other control signals to print engine 101 for recording images onto recording media. Print buffer 109 has a first section for storing print data to be printed by one of print heads 56 a and 56 b , and a second section for storing print data to be printed by the other one of print heads 56 a and 56 b . Each print buffer section has storage locations corresponding to the number of print positions of the associated print head. These storage locations are defined by printer driver 84 according to a resolution selected for printing. Each print buffer section also includes additional storage locations for transfer of print data during ramp-up of print heads 56 a and 56 b to printing speed. Print data is transferred from print data store 107 in host processor 2 to storage locations of print buffer 109 that are addressed by printer driver 84 . As a result, print data for a next scan may be inserted into vacant storage locations in print buffer 109 both during ramp up and during printing of a current scan. FIG. 11 depicts a block diagram of a combined configuration for control logic 94 and I/O ports unit 96 , which as mentioned above, I/O ports unit 96 may be included within control logic 94 . In FIG. 11, internal bus 112 is connected to printer bus 97 for communication with printer CPU 91 . Bus 112 is coupled to host computer interface 113 (shown in dashed lines) which is connected to bi-directional line 76 for carrying out bi-directional communication. As shown in FIG. 11, bi-directional line 76 may be either an IEEE-1284 line or a USB line. Bi-directional communication line 76 is also coupled to printer interface 74 of host processor 2 . Host computer interface 113 includes both IEEE-1284 and USB interfaces, both of which are connected to bus 112 and to DRAM bus arbiter/controller 115 for controlling RAM 99 which includes print buffer 109 (see FIGS. 9 and 10 ). Data decompressor 116 is connected to bus 112 , DRAM bus arbiter/controller 115 and each of the IEEE-1284 and USB interfaces of host computer interface 113 to decompress print data when processing. Also coupled to bus 112 are line feed motor controller 117 that is connected to line feed motor driver 34 a of FIG. 9, image buffer controller 118 which provides serial control signals and head data signals for each of print heads 56 a and 56 b , heat timing generator 119 which provides block control signals and analog heat pulses for each of print heads 56 a and 56 b , carriage motor controller 120 that is connected to carriage motor driver 39 a of FIG. 9, and ASF motor controller 125 that is connected to ASF motor driver 41 a of FIG. 9 . Additionally, EEPROM controller 121 a , automatic alignment sensor controller 121 b and buzzer controller 121 c are connected to bus 112 for controlling EEPROM 102 , an automatic alignment sensor (generally represented within sensors 103 of FIG. 9 ), and buzzer 106 . Further, auto trigger controller 122 is connected to bus 112 and provides signals to image buffer controller 118 and heat timing generator 119 , for controlling the firing of the nozzles of print heads 56 a and 56 b. Control logic 94 operates to receive commands from host processor 2 for use in CPU 91 , and to send printer status and other response signals to host processor 2 through host computer interface 113 and bi-directional communication line 76 . Print data and print buffer memory addresses for print data received from host processor 2 are sent to print buffer 109 in RAM 99 via DRAM bus arbiter/controller 115 , and the addressed print data from print buffer 109 is transferred through controller 115 to print engine 101 for printing by print heads 56 a and 56 b . In this regard, heat timing generator 119 generates analog heat pulses required for printing the print data. FIG. 12 shows the memory architecture for printer 10 . As shown in FIG. 11, EEPROM 102 , RAM 99 , ROM 92 and temporary storage 121 for control logic 94 form a memory structure with a single addressing arrangement. Referring to FIG. 11, EEPROM 102 , shown as non-volatile memory section 123 , stores a set of parameters that are used by host processor 2 and that identify printer and print heads, print head status, print head alignment, and other print head characteristics. EEPROM 102 also stores another set of parameters, such as clean time, auto-alignment sensor data, etc., which are used by printer 10 . ROM 92 , shown as memory section 124 , stores information for printer operation that is invariant, such as program sequences for printer tasks and print head operation temperature tables that are used to control the generation of nozzle heat pulses, etc. A random access memory section 121 stores temporary operational information for control logic 94 , and memory section 126 corresponding to RAM 99 includes storage for variable operational data for printer tasks and print buffer 109 . A more detailed description of a line feed operation according to the invention will now be made with reference to FIGS. 13 to 16 F. Briefly, the following discussion provides a description of increasing the line feed amount of the recording medium for each pulse of the line feed motor to achieve a faster line feed speed than conventional printers, and based on the line feed amount for each scan, controlling the number of print nozzles that are utilized for printing in each scan. In increasing the line feed speed, the inventors herein have endeavored to depart from the one-to-one line feed ratio of conventional printers where one line feed motor pulse provides a corresponding one pixel (maximum resolution pixel) line feed of the recording medium. Instead, the inventors have endeavored to provide for a line feed amount greater than one pixel for each motor pulse. Recall that in conventional printers that print in a 1200 dpi print resolution, one motor pulse results in a one 1200 dpi pixel line feed of the recording medium. That is, one pulse of the line feed motor feeds the recording medium 1/1200 inch and 1200 motor pulses are required to feed the recording medium one inch. In contrast, the invention increases the line feed amount by increasing the pixel/pulse ratio to be greater than 1 . For example, in one representative embodiment described below, the print heads have 600 dpi resolution nozzles, and a pixel/pulse ratio of 1.5 in 600 dpi resolution (the resolution fo the print head) is utilized to increase the line feed amount, and a 1200 dpi resolution print is achieved by multi-pass scans (two scans) of the 600 dpi print heads. The pixel/pulse ratio of 1.5 in a 600 dpi resolution corresponds to a pixel/pulse ratio of 3 in a 1200 dpi resolution. That is, for each pulse of the line feed motor, a line feed amount of 3 pixels in 1200 dpi resolution is provided for. A ratio of 3 pixel/pulse in 1200 dpi resolution provides a line feed amount of 1/400 inch for each pulse of the line feed motor. Therefore, 400 motor pulses are required to feed the recording medium one inch. Thus, a pixel/pulse ratio of 3 is three times faster than a pixel/pulse ratio of 1 in a 1200 dpi printer. This increase in line feed speed comes at minimal cost because existing motors can be utilized (i.e. a faster line feed motor is not required to achieve a faster line feed speed). However, as will be described below, the invention not only provides for a faster line feed speed, but also provides for printing in a high resolution. That is, although a faster line feed speed is obtained by increasing the pixel/pulse ratio, a high resolution (e.g. 1200 dpi) image can still be printed by controlling the number of nozzles that are utilized in each scan based on the line feed amount. A more detailed description of the increased pixel/pulse ratio will now be made, with a more detailed description of the nozzle control following thereafter. As described above with regard to FIG. 5, line feed motor 34 drives line feed shaft 36 via line feed geartrain 40 . Line feed shaft 36 includes line feed rollers 36 a . When a sheet of a recording medium engages line feed rollers 36 a , it is pinched between line feed rollers 36 a and pinch rollers 36 b . As the line feed motor rotates, it engages geartrain 40 to turn line feed rollers 36 a , thereby feeding the sheet through the printer. As stated above, line feed motor 34 may be a stepper motor that rotates in pulsed increments. Each pulse of line feed motor 34 feeds the sheet of the recording medium through the printer. The amount of line feed of the recording medium for each pulse of the line feed motor depends on several factors, including the incremental pulse value of the line feed motor (i.e. the number of degrees of rotation for each pulse of the line feed motor), the geartrain ratio, and the line feed roller size. As mentioned above, each of these factors have been set in prior art systems to provide a pixel/pulse ratio of 1. In the present invention, each of these factors (motor pulse amount, geartrain ratio and line feed roller size) are set so that one pulse of the line feed motor results in a line feed ratio greater than one. One example of a line feed motor, geartrain, and line feed roller design to achieve a 1.5 pixel/pulse line feed ratio in a pixel resolution of a print head will now be described with reference to FIGS. 13 to 15 . It should be noted that a 1.5 pixel/pulse ratio in a pixel resolution of a print head is not the only ratio that may be used in practicing the invention and other line feed ratios may be also be utilized to achieve a faster line feed speed. For instance, the invention may be applied to a printer with line feed ratios of n.5 pixel/pulse, n.25 pixel/pulse, n.333 pixel/pulse, n.75 pixel/pulse, etc., where n is a whole number greater than one. However, for brevity, only a ratio of 1.5 will be discussed. In one representative embodiment, the invention utilizes a line feed motor that is a 200 pulse, 2—2 phase stepper motor. A 200 pulse motor provides a 1.8° step amount for each pulse (360°×200 pulses=1.8°/pulse). Line feed motor 34 also preferably provides for a speed rating of up to at least 4800 pulse/sec (pps) (1440 RPM). As will be described below, a 1440 RPM speed rating, combined with the geartrain ratio and the line feed roller size provide for a line feed speed of up to 12 inches/sec. Of course, the invention is not limited to utilizing the foregoing motor specifications and any other motor could be utilized instead. The foregoing motor specifications are merely one example of a line feed motor that could be used in practicing the invention and variations in the motor could be implemented to achieve a faster line feed is speed. However, the foregoing line feed motor specifications have been included in the present example of a 1.5 pixel/pulse line feed amount in the resolution of the print head. Line feed motor 34 engages and drives geartrain 40 . One example of geartrain 40 is depicted in more detail in FIGS. 13 and 14. As seen in FIGS. 13 and 14, line feed motor 34 includes pinion 40 a connected to drive shaft 34 a of line feed motor 34 . Pinion 40 a engages and drives gear 40 b . Gear 40 b is connected to pinion 40 c so that they rotate together when gear 40 b is driven by pinion 40 a . In this regard, gear 40 b and pinion 40 c may be molded together as one entity, or may be separate gears attached to a common shaft. Pinion 40 c engages and drives gear 40 d . Gear 40 d is connected to and drives line feed drive shaft 36 . Drive shaft 36 includes line feed rollers 36 a attached to drive shaft 36 . Line feed rollers 36 a are preferably made of a rubber material in order pick up the recording medium and feed it through the printer with minimum slippage. Additionally, line feed rollers 36 a are approximately 16.17 mm in diameter. Of course, a different line feed roller size and material could also be implemented in the present invention. Line feed rollers 36 a are engaged by pinch rollers 36 b which are attached to the printer chassis and apply pressure against the recording medium when it is engaged and driven by line feed rollers 36 a . In the present example of a 1.5 pixel/pulse line feed amount in theresolution the print head, the geartrain ratio has been designed to be approximately 1:8.3333. Of course, the invention is not limited to the geartrain configuration and ratio shown in FIGS. 13 and 14 and any other geartrain design could be implemented to achieve the results of the present invention. However, the geartrain shown in FIGS. 13 and 14 has been implemented, in conjunction with the motor specifications described above, to achieve the line feed amount of 1.5 pixel/pulse of the present example. FIG. 15 is a diagram depicting a geartrain similar to geartrain 40 for determining a paper velocity utilizing a motor specification, a geartrain ratio and a line feed roller size. In FIG. 15, motor 234 drives pinion 240 a , which drives gear 240 b and pinion 240 c . Pinion 240 c drives gear 240 d that is connected to and drives line feed roller 236 a. In order to obtain a desired line feed amount (ΔP) for each pulse of the line feed motor (in this case a 1.5 pixel/pulse ratio or a 1/400 inch line feed amount), each of the foregoing elements are designed to provide the desired feed amount. The following formula can be utilized to obtain the desired feed amount. Δ     P = R × Z 1 × Z 3 Z 2 × Z 4 × Δ     θ 1 In FIG. 15, θ 1 generally represents one pulse (step amount) of the line feed motor, Z 1 , Z 2 , Z 3 and Z 4 , generally represent gears 240 a , 240 b , 240 c and 240 d , R generally represents the diameter of line feed roller 236 a , and ΔP represents the line feed amount. In the present example, a ΔP of 1/400 inch is the desired line feed amount. Therefore, utilizing the foregoing motor specification, geartrain ratio and line feed roller size, a 1/400 (or 1.5 pixel/pulse) line feed amount is achieved for a printer that prints in 1200 dpi resolution. As stated above, the line feed motor preferably provides for at least a 4800 pps speed rating. Utilizing the line feed amount (ΔP=1/400 inch) and the motor pulse rate (4800 pps), the paper velocity can be determined from the equation, ΔV p =ΔP×pulse rate. Therefore, a paper velocity of up to 12 inch/sec can be achieved. Although a faster line feed speed (1/400) is achieved by the foregoing line feed drive assembly design, the invention further provides for control over the number of print head nozzles and the line feed motor pulses utilized in printing an image in order to achieve a printed image with the desired resolution. For a better understanding, consider FIGS. 16A to 16 D. FIG. 16A depicts a sample pattern of ink droplets printed at a 600 dpi×600 dpi resolution and FIG. 16B depicts a sample pattern of ink droplets printed at a 1200 dpi×1200 dpi resolution. In each of FIGS. 16A and 16B, the print head scans from right to left in a forward scan and from left to right in a reverse scan, and the line feed direction is from top to bottom (meaning that the paper is advanced in a top to bottom direction so that the print head nozzles move from Row 1 towards Row 2 when the paper is advanced. A description will now be made with regard to FIGS. 16C and 16D of a 600 dpi×600 dpi print for a line feed ratio of 1.5 pixel/pulse, where one pixel is a 1200 dpi pixel (the maximum resolution of the printer is 1200 dpi). For each of FIGS. 16C and 16D, the print head nozzles are assumed to be spaced at a 600 dpi interval, similar to the print head described with regard to FIG. 8 . In FIG. 16C, ink droplets (indicated by the solid dark dots) have been printed in one scan of the print head on rows 1, 3 and 5, each spaced 600 dpi apart along the line feeding direction. After the first scan of the print head, the recording medium is advanced for a second scan of the print head. As seen in FIG. 16C, one pulse of the line feed motor results in a 1.5 pixel line feed of the paper. That is, the paper is fed one and one-half 600 dpi pixels by one pulse of the line feed motor. If the print head were to perform a scan and print ink droplets after one pulse of the line feed motor, ink droplets would be printed at the locations shown by the white dots. Printing after one pulse would not provide a clear 600 dpi image since the ink droplets would be offset (in the line feeding direction) by one 1200 dpi pixel. As shown in FIG. 16D, two line feed motor pulses are needed to advance the paper to perform a clear 600 dpi print. As such, for a 600 dpi print mode, increments of six 1200 dpi pixels are performed (corresponding to 2 motor pulses) in order to obtain a clear 600 dpi image. To summarize the foregoing, in a printer that has a maximum print resolution of 1200 dpi and a line feed ratio of 1.5 pixel/pulse in the resolution of the print head (600 dpi), for printing in a 600 dpi mode, line feed increments of 6 (1200 dpi) pixels are utilized based on two motor pulses, and for printing in a 1200 dpi mode, line feed increments of 3 (1200 dpi) pixels are utilized based on one motor pulse. However, in order to utilize line feed increments of 3 or 6 pixels, the number of nozzles that are available for printing in any one scan are controlled to correspond to the line feed increments. For example, in the prior art systems that have a one pixel/pulse line feed ratio, controlling the number of nozzles available for printing was generally not a factor. For instance, if a print head having 304 nozzles were implemented in the prior art systems to print a continuous image (i.e., an image with ink droplets printed by each nozzle in every scan), all 304 nozzles could be made available for printing in each scan. That is, a first scan could print with all 304 nozzles and, due to the one pixel/pulse line feed ratio, the paper could easily be advanced 304 pixels to line up the print head nozzles for printing the next scan, without regard to the line feed ratio. The paper can be advanced one pixel at a time to provide for printing the continuous image without any gaps because a whole number of motor pulses result in a whole number pixel advancement. However, in the present invention, if the same continuous image were to be printed with the same 304 nozzle print head, but the line feed ratio were changed to 1.5 pixel/pulse in the resolution of the print head, a continuous image could not be printed using all 304 nozzles. That is, if all 304 nozzles were used for printing and the paper needed to be advanced 304 pixels for printing the next scan, the line feed ratio would result in either a gap in the continuous image, or an overlap in the image. For instance, as stated above, to maintain a continuous image at 600 dpi with a 1.5 pixel/pulse ratio in 600 dpi resolution, line feed increments of 3 pixels in 600 dpi are required. An advancement of 304 pixels divided by increments of 3 pixels in 600 dpi results in 202.667 motor pulses to achieve a continuous image. Since a fractional motor pulse can not be obtained in a stepper motor, the best advancement that could be obtained would be either 303 (600 dpi) pixels (202 motor pulses), which would result in an overlap of one 600 dpi pixel, or 300 (600 dpi) pixels (200 motor pulses), which would result in an overlap of four 600 dpi pixels. Therefore, not all of the 304 nozzles are available for printing and the print head nozzles are controlled to provide for a continuous image based, at least in part, on the line feed amount. In a 600 dpi print mode, an increment of the line feed motor is two motor pulses, corresponding to 3 pixels of 600 dpi. In a 1200 dpi print mode, an increment of the line feed motor is one motor pulse, corresponding to 3 pixels of 1200 dpi (1.5 pixels of 600 dpi). The number of nozzles available for printing are controlled, in part, by the print driver. Although the print head contains 304 black nozzles and 80 color nozzles for each of cyan, magenta and yellow inks, the print driver is configured for a number of nozzles that are evenly divisible by the line feed ratio. In the example where the line feed ratio is set to 1.5 pixel/pulse in 600 dpi, the print driver is configured for 300 black nozzles and 78 color nozzles. 300 black nozzles allows for a 300 (600 dpi) pixel line feed advancement utilizing 200 motor pulses. Likewise, 78 color nozzles allows for a 78 (600 dpi) pixel line feed advancement utilizing 52 motor pulses. Therefore, for printing the continuous image, a first scan is performed to print with 300 nozzles, then the paper is fed 600 (1200 dpi) pixels (200 line feed motor pulses) to print the next scan similarly, for color, the first scan prints 78 nozzles and the paper is advanced 156 (1200 dpi) pixels (52 line feed motor pulses) to print the next scan. As a result, a continuous image can be printed without gaps or overlap in the printed pixels while at the same time, maintaining a faster line feed speed. In controlling the number of nozzles, for the black print head having 304 nozzles, the print driver and printer are set-up to nominally print with nozzles 3 to 302 , with nozzles 1 , 2 , 303 and 304 being (virtually) unavailable. That is, the print driver is nominally set-up to utilize the memory positions for nozzles 3 to 302 . However, depending upon the print data and the line feed amount, the print driver may adjust the memory locations to shift up or down one or two nozzles. That is, the print driver may shift the data in the memory to utilize nozzles 1 to 300 (down two nozzles), 2 to 301 (down one nozzle), 4 to 303 (up one nozzle) or 5 to 304 (up two nozzles) depending on the image data to be printed and the line feed amount. Additionally, the printer ASIC may be utilized to mechanically shift the nozzles being utilized for printing. Of course, as stated above, the invention is not limited to the 1.5 pixel/pulse line feed ratio in the resolution of the print head (600 dpi) in conjunction with 300 black and 78 color nozzles and other combinations could be provided for to obtain an increased line feed speed over the one pixel/pulse ratio. For instance, if a line feed ratio of 1.25 pixel/pulse in 600 dpi were utilized, 300 black and 80 color nozzles could also be utilized to obtain a continuous printed image (300 pixels+1.25=240 motor pulses, 80 pixels+1.25=64 motor pulses). In this case, the maximum printable resolution is 2400 dpi. Similarly, if a line feed ratio of 1.333 pixel/pulse in 600 dpi were utilized, 300 black and 80 color nozzles could be utilized (300 pixels+1.333˜225 motor pulses, 80 pixels+1.333˜60 motor pulses). In this case, the maximum printable resolution is 1800 dpi. A description will now be made with regard to FIGS. 17 and 18 of control over line feed and buffer loading for printing black data where white spaces are encountered in the print buffer loading as the first line of data. FIG. 17 is a flowchart depicting process steps performed in a print driver for loading of a print buffer for black print data. Briefly, the process steps perform rasterization, color conversion and halftoning of the image data. Then the print buffer is loaded line-by-line with the loading process determining which line in the buffer to begin loading data based on whether a white space (no black print data) is present as the first line of data. In step S 1701 , the print driver rasterizes the image data from a display resolution to a print resolution. For instance, the print driver may convert the image data from a typical 72 dpi display resolution to a 300 dpi×300 dpi print resolution. A 300 dpi×300 dpi rasterization resolution may be utilized where the printer prints in 300, 600, 1200, etc. dpi modes. The rasterized image data is then subjected to a color conversion process in step S 1702 to convert multivalue RGB (Red, Green and Blue) values for each pixel of the rasterized image into CMYK (cyan, magenta, yellow and black) values for printing. Then, the CMYK values for the image are stored in respective memory blocks for each of the color values (step S 1703 ). It should be noted that the process steps of FIG. 17 generally apply to black data and not color data. Therefore, the present discussion of FIG. 17 is limited to a case for printing black data. After the data is stored in the memory blocks, the image data is subjected to a halftoning process in step S 1704 . After the halftoning process, the buffer loading process begins. In the following discussion of the buffer loading, two scenarios will be discussed: a case where the first line being loaded in the buffer contains black data, and a case where the first (x) lines of data to be loaded in the buffer do not contain any black data, i.e. they represent white space. Additionally, the following discussion relates to a case where the buffer is being loaded for printing in the middle of a page. That is, some data has already been printed on the page and the paper is ready to be fed through the printer by the line feed motor for printing the next scan. The process steps will be described generally and then examples will be presented for further understanding. In step S 1705 , the next line of data is obtained. Then, in step S 1706 , a determination is made whether any data is currently being stored in the print buffer. That is, a determination is made whether the print buffer currently contains at least one line of data. In a case where the print buffer has just released the print data to the printer and the data has been printed, this determination would be NO since the current line of data is the first line of data to be loaded into the empty print buffer. If however, there is at least one line of data in the print buffer, then flow proceeds to step S 1712 where the current line, whether it contains black data or not, is stored in the next line of the print buffer. Then, a determination is made whether the buffer is full, and if so, the data is sent to the printer for printing. If the buffer is not full, then flow returns to step S 1705 to get the next line of data. At this point, a loop is entered into between steps S 1705 , S 1706 , S 1712 and S 1713 until the print buffer is fully loaded, at which point flow exits the loop to step S 1714 to send the data in the buffer to the printer for printing. Returning to step S 1706 , if a determination is made that no data is currently in the print buffer, then a determination is made whether the current line is all white data (step S 1707 ). In a case where the current line is the first line being loaded into the print buffer and the current line contains black data, flow proceeds to steps S 1708 , S 1709 , S 1710 and S 1711 . In this case, the black line is merely stored in the first line of the print buffer and flow returns to step S 1705 whereby the foregoing loop (S 1705 , S 1706 , S 1712 , S 1713 ) is entered into until the print buffer is full. If however, a determination is made in step S 1707 that the current line of data is all white, then a line counter value (Lcount) is incremented by one (step S 1715 ) to account for the current white space line. Then, flow returns to step S 1705 to get the next line. In the case where the first line of data is white space, then for the next pass through the process steps, flow would proceed from step S 1705 to S 1706 and back to S 1707 . If the second (current) line of data is also white (i.e. does not contain any black data), then a loop is entered into between steps S 1705 , S 1706 , S 1707 and S 1715 until a line of black data is encountered. Once a line of black data is encountered in step S 1707 , then in step S 1708 a skip amount (SkipA) is calculated. The skip amount determines how many lines the paper is to be fed to account for the white space. That is, step S 1708 determines how many lines the line feed motor will advance the paper due to the white space. The SkipA value is determined by dividing the Lcount (the number of lines of white data that were counted in step S 1715 ) by Y, where Y is the number of pixels corresponding to the amount of line feed for one pulse of the line feed motor. For instance in a case where the line feed ratio is 1.5 in 600 dpi, it corresponds to 3 pixels in 1200 dpi. That is, where the line feed ratio in the print head resolution is (m×1/n), the number of pixels in a print resolution printed by the printer corresponds to the line feed amount for one pulse of the line feed motor. The result of the calculation in step S 1708 is rounded down to the nearest whole number. Therefore, step S 1708 performs integer math that leaves a remainder. For example, in a case where 8 lines of white space are encountered and the line feed ratio is 1.5, Lcount would be 8 and the result of step S 1708 would be 2 (8/3=2, with a remainder of 2). Therefore, the print driver would determine that the paper is to be advanced 2 pulses which corresponds to six 1200 dpi pixels. After the skip amount is calculated in step S 1708 , a buffer offset amount (Boffset) is calculated in step S 1709 . The buffer offset value determines which line in the print buffer to begin loading the black print data to account for the remainder in step S 1708 . The value Boffset is calculated by the formula Boffset=Lcount−(SkipA×Y). In the foregoing case where Lcount was 8, the line feed ratio was 1.5 in 600 dpi (3 pixels in 1200 dpi) and SkipA was calculated to be 2, the buffer offset would be 2 (8 −(2×3)=2), which corresponds to the remainder from step S 1708 . Then, in step S 1710 , the starting position in the print buffer for loading the black data of the current line is adjusted. In the present example, the starting position in the print buffer would be adjusted by two lines and the first two lines of the print buffer would be left blank with the black data of the current line being loaded in line three of the print buffer. The current line is then stored in the print buffer (step S 1711 ) with flow returning to step S 1705 , whereby the S 1705 , S 1706 , S 1712 , S 1713 loop is entered into until the print buffer is full. For a better understanding of the process steps, consider the following examples. In the following examples, it is assumed that the line feed ratio has been set to 1.5 pixel/pulse in the resolution of the print head (600 dpi). Therefore, as described above, although print head 56 a contains 304 nozzles, only 300 nozzles are utilized in any one scan to accommodate the line feed ratio of 1.5 pixel/pulse in 600 dpi. Accordingly, only 300 lines of the print buffer are utilized. Additionally, it is assumed that the print buffer has just been filled and the print data sent to the printer in step S 1714 . Therefore, at least one scan has been performed and the paper is ready to be fed by the line feed motor for printing the next line. Two examples will be discussed. The first example discusses a case where the next line of data (the first line to be processed for filling the print buffer for the next scan) contains black data. The second example discusses a case where the next 31 lines of data do not contain any black data and therefore represent white space. In the first example, in step S 1705 , the next line of data is obtained. In step S 1706 , a determination is made whether there is currently any data in the print buffer. Since the print buffer has just been emptied and the current pass through the process steps is for the first line of the print buffer, the result of the determination is NO and flow proceeds to step S 1707 . In step S 1707 , a determination is made whether the current line is all white, i.e. whether it contains any black data. In the present example, the first line does contain black data and therefore the result of the determination is NO and flow proceeds to step S 1708 . In step S 1708 , the Skip amount (SkipA) is calculated. Since the value of Lcount is zero (i.e., step S 1715 has not been carried out to increment the Lcount value), the result of the calculation in step S 1708 is zero. Similarly, the result of step S 1709 (Boffset) is zero and no adjustment is made in the buffer loading in step S 1710 . Therefore, the current line is stored in the first line of the print buffer (step S 1711 ) and flow returns to step S 1705 to obtain the next line. Since the first line of data has been stored in the print buffer, step S 1706 results in a YES determination and the next line is stored in the print buffer in step S 1712 . The next line is stored in the print buffer regardless of whether it contains black data or not. Then, a determination is made whether the print buffer is full in step S 1713 . Since the print buffer holds 300 lines of data and the current pass only fills the second line, the result of the determination is NO and flow returns to step S 1705 to obtain the next line. At this point, a continuous loop is entered into between steps S 1705 , S 1706 , S 1712 and S 1713 until all 300 lines of the print buffer have been filled. When all 300 lines of the print buffer have been filled, then the result of step S 1713 is YES and flow proceeds to step S 1714 where the data in the print buffer is sent to the printer. After the data has been sent to the printer in step S 1714 , flow returns to step S 1705 to obtain the next line. At this point, a second example will be discussed in which the next 31 lines do not contain black data and therefore represent white space. As such, in step S 1706 a determination is made whether there is any data in the print buffer. Since the print buffer has just been emptied, the result of the determination is No and flow proceeds to step S 1707 . In step S 1707 , a determination is made whether the current line is all white data, i.e. whether it contains any black data. Since the first 31 lines are white space, the result of the determination is YES and flow proceeds to step S 1715 . In step S 1715 , a value Lcount is incremented by one from 0 to 1. Then flow proceeds to step S 1705 to obtain the next line. After obtaining the second line in step S 1705 , a determination is made in step S 1706 whether there is any data in the print buffer. Since the first line was white data, nothing was stored in the print buffer and the result of the determination is NO. Therefore, flow proceeds to step S 1707 , whereby it is determined that the current line is again all white and the value Lcount is again incremented by one, this time from 1 to 2. This loop between steps S 1705 , S 1706 , S 1707 and S 1715 continues for the first 31 lines since each of the first 31 lines are all white. As such, the value of Lcount is incremented to 31 before flow returns to step S 1705 for the thirty-second line of data. After the thirty-second line of data is obtained in step S 1705 , the result of the determination in step S 1706 is still NO since none of the first 31 lines of data have been stored in the buffer. Therefore, flow proceeds to step S 1707 where a NO determination is made since the current, line contains black data. As such, flow proceeds to step S 1708 . In step S 1708 , the skip amount is calculated. The skip amount is determined by the formula SkipA=Lcount/Y. Recall that Lcount has been incremented for each of the first 31 lines to a value of 31 and the value for Y is 3(line feed ratio of 1.5 pixel in the print head resolution or m×1/n in the print head resolution, where m equal 3 and equals 2 and Y equals 3). Therefore, SkipA is calculated to be 10 units (31/3=10, with a remainder of 1). As a result, the paper would be fed 10 motor units, or 10 pulses which corresponds to 30 pixels. In step S 1709 , the buffer offset (Boffset) is calculated to be 1 (Boffset=(31−(10×3)=1). Then, the starting position in the print buffer is offset by the value Boffset, here one line. Accordingly, the first line of the print buffer is left blank and the data begins loading to store the current line in the second line of the print buffer. Flow then returns to step S 1705 , whereby the S 1705 , S 1706 , S 1712 and S 1713 loop is entered into to process the next 299 lines of data. Once all 299 lines of data have been filled, the data is released to the printer for printing. FIG. 18 is a flowchart depicting process steps for performing a process similar to that of FIG. 17 . The process steps are preferably performed in a print driver for loading of a print buffer for black print data. Briefly, the process steps perform rasterization, color conversion and halftoning of the image data. Then the print buffer is loaded Y lines at a time, where Y corresponds to the number of pixels to be printed corresponding to the amount of line feed for one pulse of the line feed motor. For example, in the case described above where the line feed ratio is 1.5 pixel/pulse in a print head resolution of 600 dpi, Y would be 3. That is, one line feed motor pulse of the line feed motor would feed the recording medium three 1200 dpi pixels for printing in a 1200 dpi print mode, and two motor pulses of the line feed motor would feed the recording medium three 600 dpi pixels (or six 1200 dpi pixels) for printing in a 600 dpi print mode. Therefore, for each of these two cases, Y is equal to 3. FIG. 18 will be described in a case where Y equals 3 for a 600 dpi print mode. Of course, the same steps would apply if the printer were printing in a 1200 dpi print mode since Y would also be 3. Three examples will be presented with regard to FIG. 18 . In the each of the examples, similar to the discussion of FIG. 17, it will be assumed that the print buffer has just been emptied and that the next lines of data being processed are the first lines to be loaded into the print buffer. In a first example, the first line of data being processed contains black data. In a second example, the first two lines of data to be loaded into the print buffer are white data and the third line contains black data. Finally, in a third example, the first thirty-one lines of data to be loaded into the print buffer are white data and the thirty-second line contains black data. In FIG. 18, steps S 1801 to S 1804 are the same as steps S 1701 to S 1704 described above. Therefore, the description of these steps will not be repeated here. In the first example, in step S 1605 , the next Y lines (3 lines in the present example) of print data are obtained. Then, in step S 1806 , a determination is made whether a flag “skip” is set to 0. Nominally, when the print buffer is emptied in step S 1814 , the skip flag is set to 1. Therefore, in the present case, the print driver determines in step S 1806 that the skip flag is set to 1 and flow proceeds to step S 1807 . In step S 1807 , a determination is made whether all of the Y lines contain white data. This step determines whether or not the line feed motor is to feed the recording medium a number of lines corresponding to the line feed ratio to skip the white space. In the present example, the print driver determines whether all of the first 3 lines of data are white. Since the present example contains black data in the first line of data, the result of the determination in step S 1807 is NO and flow proceeds to step S 1808 . Step S 1808 increments the buffer offset in order to adjust the loading of the print buffer to accommodate white data encountered as the first (x) lines of data. Therefore, step S 1808 increments the buffer offset (Boffset) by the number of lines of white data encountered before a line that contains black data is encountered. In the present case where Y is 3, the most white lines of data that could be encountered before a line with black data would be encountered would be 2. In the present example where the first line of data contains black data, the value of Boffset is not incremented and flow proceeds to step S 1809 where the skip flag is set to 0. Then, in step S 1810 , the starting position for loading the print data into the print buffer is adjusted based on the value of Boffset. In the present example, Boffset is 0 and therefore the first line of print data is loaded into the first line of the print buffer. Accordingly, in step S 1811 , the first 3 lines of print data are loaded into the print buffer in lines 1 to 3 of the print buffer, respectively. Flow then returns to step S 1805 to obtain the next Y (3) line of data. Then, in step S 1806 , the print driver determines that the skip flag is 0 since the skip flag was set to 0 in step S 1809 . Accordingly, flow proceeds to step S 1812 where the current 3 lines of data are stored in the print buffer. Then, step S 1813 determines whether the print buffer is full. Since the print buffer contains 300 lines (corresponding to the 300 nozzles utilized for printing black data with print head 56 a ), the determination is NO and flow returns to step S 1805 . The process continues in the S 1805 , S 1806 , S 1812 , S 1813 loop until all 300 lines of the print buffer have been filled with print data. When the buffer is full, then flow proceeds from step S 1813 to step S 1814 where the skip flag is reset to 1, and SkipA and the print data are sent to the printer, thereby emptying the print buffer. In the present case, SkipA is 0 since flow did not pass through step S 1815 . Next, a second example will be discussed in which, after the print buffer is emptied from the first example described above, the print data for the next Y (3) lines is obtained in step S 1805 . In the present (second) example, recall that the first two lines of data are white data and that the third line contains black data. In step S 1806 , the print driver determines that the skip flag is 1 (it was reset to 1 in step S 1814 when the print buffer was emptied for the first example). Then, in step S 1807 , the print driver determines that all of the Y (3) lines of data are not all white. That is, only the first two lines are all white, but the third line contains black data. Therefore, flow proceeds to step S 1808 . In step S 1808 , the buffer offset (Boffset) is incremented by the number of lines of all white data that are encountered before a line with blacks data is encountered. In the present example, the first two lines of data are all white and therefore Boffset is incremented by two. Then, in step S 1809 the skip flag is set to 0 and flow proceeds to step S 1810 . In step S 1810 , the starting position for loading the print data in the print buffer is adjusted based on the value of Boffset. In the present example, the starting position is adjusted by two lines since Boffset is 2. Therefore, in step S 1811 , the first two lines in the print buffer are skipped and the first line that contains black data (the third line of the 3 Y lines in the present example) is loaded into line three of the print buffer. Flow then proceeds to step S 1805 to obtain the next Y (3) lines of data. In step S 1806 , the print driver determines that the skip flag is 0 and therefore, flow proceeds to step S 1812 . At this point, the loop S 1805 , S 1806 , S 1812 , S 1813 is entered into until the print buffer has been filled. Once the print buffer has been filled, flow proceeds to step S 1814 where the skip flag is reset to 1 and SkipA (again, 0 in the present example) and the print data are sent to the printer, thereby emptying the print buffer. At this point, a third example will be discussed in which the first thirty-one lines of print data to be loaded into the print buffer all contain white data. In step S 1805 , the next Y (3) lines of print data are obtained, and in step S 1806 , the print driver determines that the skip flag is 1, whereby flow proceeds to step S 1807 . In step S 1807 , the print driver determines that all of the Y (3) lines of data are white. Therefore, flow proceeds to step S 1815 where the value SkipA is incremented by one. Each increment of SkipA corresponds to Y, such that each increment of SkipA results in a line feed of 3 pixels. For example, in the present case where the printer is printing at 600 dpi and SkipA is 1, the line feed motor performs two motor pulses to feed the recording medium three 600 dpi pixels, thereby skipping the 3 white space lines. Flow then returns to step S 1805 where the next Y (3) lines of data are obtained. In step S 1806 , the print driver determines that the skip flag is still set to 1 and therefore flow proceeds to step S 1807 . In the second pass through step S 1807 of the current example, the print driver again determines that all 3 lines of data are white and therefore, flow again proceeds to step S 1815 where, SkipA is incremented from 1 to 2. Flow continues in this S 1805 , S 1806 , S 1807 , S 1815 loop for the first thirty lines (10 passes) since the first thirty-one lines are all white data. Accordingly, SkipA is incremented to 10 before the eleventh pass of through the process steps. In the eleventh pass, step S 1806 determines that the skip flag is still set to 0 and therefore flow proceeds to step S 1807 . In step 1807 , the print driver determines that all of the Y (3) lines do not contain white data and therefore flow proceeds to step S 1808 . In step S 1808 , the buffer offset (Boffset) value is incremented by 1. Recall that the first thirty-one lines of data where all white and therefore, for the current pass through the process steps, one line of white data (the thirty-first line) is encountered before a line containing black data is encountered. Flow then proceeds to steps S 1809 , S 1810 and S 1811 where the skip flag is set to 0, the starting position for loading of the print data in the print buffer is adjusted by one line, and lines 32 and 33 of the print data are stored in the print buffer in lines 2 and 3 , respectively. Flow then returns to step S 1805 where the S 1805 , S 1806 , S 1812 , S 1813 loop is entered into until all 300 lines of the print buffer have been filled, whereby flow proceeds to step S 1814 . In step S 1814 , the skip flag is reset to 1 and the SkipA value (10) and the print data are sent to the printer. When the printer receives the SkipA value, the line feed motor advances the recording medium a number of pulses corresponding Y, in the present example, where the print is in 600 dpi resolution, 30 (600 dpi) lines or 20 motor pulses. The invention has been described with respect to particular illustrative embodiments. It is to be understood that the invention is not limited to the above-described embodiments and that various changes and modifications may be made by those of ordinary skill in the art without departing from the spirit and scope of the invention.

A printer that prints an image having a resolution higher than a resolution of nozzles on a print head on a recording medium by scanning the print head across a region of the recording medium a plural-number of times, said print head having nozzles spaced at a nozzle pitch which is a reciprocal number of the resolution of the nozzles and adapted to eject ink from the nozzles on the basis of print data. The printer has a line feeding motor that is actuated in a unit of a pulse, and a line feeding device, driven by the line feeding motor actuated in the unit of the pulse, for feeding the recording medium in a unit of a predetermined feeding length fed by an actuating pulse, the predetermined feeding length being (m/k×nozzle pitch), where k is the resolution of the printed image/the resolution of the nozzles, m and k are integers, and m is greater than k but indivisible by k. A controller controls the line feeding motor to actuate in the unit of the pulse and control a number of the nozzles utilized for printing the image when printing an image on the recording medium by scanning the print head across the recording medium a plural-number of times.

BACKGROUND OF THE INVENTION This invention relates generally to electric motors and more particularly to an electric motor having a simplified, easily assembled construction. Assembly of electric motors requires that a rotor be mounted for rotation relative to a stator so that magnets on the rotor are generally aligned with one or more windings on the stator. Conventionally, this is done by mounting a shaft of the rotor on a frame which is attached to the stator. The shaft is received through the stator so that it rotates about the axis of the stator. The frame or a separate shell may be provided to enclose the stator and rotor. In addition to these basic motor components, control components are also assembled. An electrically commutated motor may have a printed circuit board mounting various components. Assembly of the motor requires electrical connection of the circuit board components to the winding and also providing for electrical connection to an exterior power source. The circuit board itself is secured in place, typically by an attachment to the stator with fasteners, or by welding, soldering or bonding. Many of these steps are carried out manually and have significant associated material labor costs. The fasteners, and any other materials used solely for connection, are all additional parts having their own associated costs and time needed for assembly. Tolerances of the component parts of the electric motor must be controlled so that in all of the assembled motors, the rotor is free to rotate relative to the stator without contacting the stator. A small air gap between the stator and the magnets on the rotor is preferred for promoting the transfer of magnetic flux between the rotor and stator, while permitting the rotor to rotate. The tolerances in the dimensions of several components may have an effect on the size of the air gap. The tolerances of these components are additive so that the size of the air gap may have to be larger than desirable to assure that the rotor will remain free to rotate in all of the motors assembled. The number of components which affect the size of the air gap can vary, depending upon the configuration of the motor. Motors are commonly programmed to operate in certain ways desired by the end user of the motor. For instance certain operational parameters may be programmed into the printed circuit board components, such as speed of the motor, delay prior to start of the motor, and other parameters. Mass produced motors are most commonly programmed in the same way prior to final assembly and are not capable of re-programming following assembly. However, the end users of the motor sometimes have different requirements for operation of the motor. In addition, the end user may change the desired operational parameters of the motor. For this reason, large inventories of motors, or at least programmable circuit boards, are kept to satisfy the myriad of applications. Electric motors have myriad applications, including those which require the motor to work in the presence of water. Water is detrimental to the operation and life of the motor, and it is vital to keep the stator and control circuitry free of accumulations of water. It is well known to make the stator and other components water proof. However, for mass produced motors it is imperative that the cost of preventing water from entering and accumulating in the motor be kept to a minimum. An additional concern when the motor is used in the area of refrigeration is the formation of ice on the motor. Not uncommonly the motor will be disconnected from its power source, or damaged by the formation of ice on electrical connectors plugged into the circuit board. Ice which forms between the printed circuit board and the plug-in connector can push the connector away from the printed circuit board, causing disconnection, or breakage of the board or the connector. SUMMARY OF THE INVENTION Among the several objects and features of the present invention may be noted the provision of an electric motor which has few component parts; the provision of such a motor which does not have fasteners to secure its component parts; the provision of such a motor which can be accurately assembled in mass production; the provision of such a motor having components capable of taking up tolerances to minimize the effect of additive tolerances; the provision of such a motor which can be re-programmed following final assembly; the provision of such a motor which inhibits the intrusion of water into the motor; and the provision of such a motor which resists damage and malfunction in lower temperature operations. Further among the several objects and features of the present invention may be noted the provision of a method of assembling an electric motor which requires few steps and minimal labor; the provision of such a method which minimizes the number of connections which must be made; the provision of such a method which minimizes the effect of additive tolerances; the provision of such a method which permits programming and testing following final assembly; and the provision of such a method which is easy to use. In one form, the invention comprises an electric motor. A stator includes a stator core having a winding thereon. A rotor includes a shaft received in the stator core for rotation of the rotor relative to the stator about the longitudinal axis of the shaft. A housing connected together with the stator and rotor forms an assembled motor, the housing being adapted to support the stator and rotor. A printed circuit board controls operation of the motor, the printed circuit board having a power contact mounted thereon for receiving electrical power for the winding. The housing is formed with a plug receptacle for receiving a plug from an external electrical power source into connection with the power contact, the power contact being received in the plug upon connection of the plug to the power contact, the housing including a plug locator locating the plug relative to the printed circuit board so that the power contact is received only partially into the plug upon connection to the plug. Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded elevational view of an electric motor in the form of a fan; FIG. 2 is an exploded perspective view of component parts of a stator of the motor; FIG. 3 is a vertical cross sectional view of the assembled motor; FIG. 4 is the stator and a printed circuit board exploded from its installed position on the stator; FIG. 5 is an enlarged, fragmentary view of the shroud of FIG. 1 as seen from the right side; FIG. 6 is a side elevational view of a central locator member and rotor shaft bearing; FIG. 7 is a right end elevational view thereof; FIG. 8 is a longitudinal section of the locator member and bearing; FIG. 9 is an end view of a stator core of the stator with the central locator member and pole pieces positioned by the locator member shown in phantom; FIG. 10 is an opposite end view of the stator core; FIG. 11 is a section taken in the plane including line 11--11 of FIG. 10; FIG. 12 is a greatly enlarged, fragmentary view of the motor at the junction of a rotor hub with the stator; FIG. 13 is a section taken in the plane including line 13--13 of FIG. 5, showing the printed circuit board in phantom and illustrating connection of a probe to a printed circuit board in the shroud and a stop; FIG. 14 is a section taken in the plane including line 14--14 of FIG. 5 showing the printed circuit board in phantom and illustrating a power connector plug exploded from a plug receptacle of the shroud; and FIG. 15 is an enlarged, fragmentary view of the motor illustrating snap connection of the stator/rotor subassembly with the shroud. FIG. 16 is a block diagram of the microprocessor controlled single phase motor according to the invention. FIG. 17 is a schematic diagram of the power supply of the motor of FIG. 16 according to the invention. Alternatively, the power supply circuit could be modified for a DC input or for a non-doubling AC input. FIG. 18 is a schematic diagram of the low voltage reset for the microprocessor of the motor of FIG. 16 according to the invention. FIG. 19 is a schematic diagram of the strobe for the Hall sensor of the motor of FIG. 16 according to the invention. FIG. 20 is a schematic diagram of the microprocessor of the motor of FIG. 16 according to the invention. FIG. 21 is a schematic diagram of the Hall sensor of the motor of FIG. 16 according to the invention. FIG. 22 is a schematic diagram of the H-bridge array of witches for commutating the stator of the motor of FIG. 16 according to the invention. FIG. 23 is a flow diagram illustrating the operation of the microprocessor of the motor of the invention in a mode in which the motor is commutated at a constant air flow rate at a speed and torque which are defined by tables which exclude resonant points. FIG. 24 is a flow diagram illustrating operation of the microprocessor of the motor of the invention in a run mode (after start) in which the safe operating area of the motor is maintained without current sensing by having a minimum off time for each power switch, the minimum off time depending on the speed of the rotor. FIG. 25 is a timing diagram illustrating the start up mode which provides a safe operating area (SOA) control based on speed. FIG. 26 is a flow chart of one preferred embodiment of implementation of the timing diagram of FIG. 25 illustrating the start up mode which provides a safe operating area (SOA) control based on speed. FIG. 27 is a timing diagram illustrating the run up mode which provides a safe operating area (SOA) control based on speed. FIG. 28 is a flow diagram illustrating the operation of the microprocessor of the motor of the invention in a run mode started after a preset number of commutations in the start up mode wherein in the run mode the microprocessor commutates the switches for N commutations at a constant commutation period and wherein the commutation period is adjusted every M commutations as a function of the speed, the torque or the constant air flow rate of the rotor. Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and in particular to FIGS. 1 and 3, an electric motor 10 constructed according to the principles of the present invention includes a stator 22, a rotor 24 and a housing 26 (the reference numerals designating their subjects generally). In the illustrated embodiment, the motor 10 is of the type which the rotor magnet is on the outside of the stator, and is shown in the form of a fan. Accordingly, the rotor 24 includes a hub 28 having fan blades 30 formed integrally therewith and projecting radially from the hub. The hub 28 and fan blades 30 are formed as one piece of a polymeric material. The hub is open at one end and defines a cavity in which a rotor shaft 32 is mounted on the axis of the hub (FIG. 3). The shaft 32 is attached to the hub 28 by an insert 34 which is molded into the hub, along with the end of the shaft when the hub and fan blades 30 are formed. A rotor magnet 35 exploded from the rotor in FIG. 1 includes a magnetic material and iron backing. For simplicity, the rotor magnet 35 is shown as a unitary material in the drawings. The back iron is also molded into the hub cavity at the time the hub is formed. The stator, 22 which will be described in further detail below, is substantially encapsulated in a thermoplastic material. The encapsulating material also forms legs 36 projecting axially of the stator 22. The legs 36 each have a catch 38 formed at the distal end of the leg. A printed circuit board generally indicated at 40, is received between the legs 36 in the assembled motor 10, and includes components 42, at least one of which is programmable, mounted on the board. A finger 44 projecting from the board 40 mounts a Hall device 46 which is received inside the encapsulation when the circuit board is disposed between the legs 36 of the stator 22. In the assembled motor 10, the Hall device 46 is in close proximity to the rotor magnet 35 for use in detecting rotor position to control the operation of the motor. The stator 22 also includes a central locator member generally indicated at 48, and a bearing 50 around which the locator member is molded. The bearing 50 receives the rotor shaft 32 through the stator 22 for mounting the rotor 24 on the stator to form a subassembly. The rotor 24 is held on the stator 22 by an E clip 52 attached to the free end of the rotor after it is inserted through the stator. The housing 26 includes a cup 54 joined by three spokes 56 to an annular rim 58. The spokes 56 and annular rim 58 generally define a shroud around the fan blades 30 when the motor 10 is assembled. The cup 54, spokes 56 and annular rim 58 are formed as one piece from a polymeric material in the illustrated embodiment. The cup 54 is substantially closed on the left end (as shown in FIGS. 1 and 3), but open on the right end so that the cup can receive a portion of the stator/rotor subassembly. The annular rim 58 has openings 60 for receiving fasteners through the rim to mount the motor in a desired location, such as in a refrigerated case (not shown). The interior of the cup 54 is formed with guide channels 62 (FIG. 5) which receive respective legs 36. A shoulder 64 is formed in each guide channel 62 near the closed end of the cup 54 which engages the catch 38 on a leg to connect the leg to the cup (see FIGS. 3 and 15). The diameter of the cup 54 narrows from the open toward the closed end of the cup so that the legs 36 are resiliently deflected radially inwardly from their relaxed positions in the assembled motor 10 to hold the catches 38 on the shoulders 64. Small openings 66 in the closed end of the cup 54 (FIG. 5) permit a tool (not shown) to be inserted into the cup to pry the legs 36 off of the shoulders 64 for releasing the connection of the stator/rotor subassembly from the cup. Thus, it is possible to nondestructively disassemble the motor 10 for repair or reconfiguration (e.g., such as by replacing the printed circuit board 40). The motor may be reassembled by simply reinserting the legs 36 into the cup 54 until they snap into connection. One application for which the motor 10 of the illustrated in the particular embodiment is particularly adapted, is as an evaporator fan in a refrigerated case. In this environment, the motor will be exposed to water. For instance, the case may be cleaned out by spraying water into the case. Water tends to be sprayed onto the motor 10 from above and to the right of the motor in the orientation shown in FIG. 3, and potentially may enter the motor wherever there is an opening or joint in the construction of the motor. The encapsulation of the stator 22 provides protection, but it is desirable to limit the amount of water which enters the motor. One possible site for entry of what is at the junction of the hub 28 of the rotor and the stator 22. An enlarged fragmentary view of this junction is shown in FIG. 12. The thermoplastic material encapsulating the stator is formed at this junction to create a tortuous path 68. Moreover, a skirt 70 is formed which extends radially outwardly from the stator. An outer edge 72 of the skirt 70 is beveled so that water directed from the right is deflected away from the junction. The openings 66 which permit the connection of the stator/rotor subassembly to be released are potentially susceptible to entry of water into the cup where it may interfere with the operation of the circuit board. The printed circuit board 40, including the components 42, is encapsulated to protect it from moisture. However, it is still undesirable for substantial water to enter the cup. Accordingly, the openings 66 are configured to inhibit entry of water. Referring now to FIG. 15, a greatly enlarged view of one of the openings 66 shows a radially outer edge 66a and a radially inner edge 66b. These edges lie in a plane P1 which has an angle to a plane P2 generally parallel to the longitudinal axis of the rotor shaft of at least about 45°. It is believed that water is sprayed onto the motor at an angle of no greater than 45°. Thus, it may be seen that the water has no direct path to enter the opening 66 when it travels in a path making an angle of 45° or less will either strike the side of the cup 54, or pass over the opening, but will not enter the opening. The cup 54 of the housing 26 is also constructed to inhibit motor failures which can be caused by the formation of ice within the cup when the motor 10 is used in a refrigerated environment. More particularly, the printed circuit board 40 has power contacts 74 mounted on and projecting outwardly from the circuit board (FIG. 4). These contacts are aligned with an inner end of a plug receptacle 76 which is formed in the cup 54. Referring to FIG. 14, the receptacle 76 receives a plug 78 connected to an electrical power source remote from the motor. External controls (not shown) are also connected to the printed circuit board 40 through the plug 78. The receptacle 76 and the plug 78 have corresponding, rectangular cross sections so that when the plug is inserted, it substantially closes the plug receptacle. When the plug 78 is fully inserted into the plug receptacle 76, the power contacts 74 on the printed circuit board 40 are received in the plug, but only partially. The plug receptacle 76 is formed with tabs 80 (near its inner end) which engage the plug 78 and limit the depth of insertion of the plug into the receptacle. As a result, the plug 78 is spaced from the printed circuit board 40 even when it is fully inserted in the plug receptacle 76. In the preferred embodiment, the spacing is about 0.2 inches. However, it is believed that a spacing of about 0.05 inches would work satisfactorily. Notwithstanding the partial reception of the power contacts 74 in the plug 78, electrical connection is made. The exposed portions of the power contacts 74, which are made of metal, tend to be subject to the formation of ice when the motor 10 is used in certain refrigeration environments. However, because the plug 78 and circuit board 40 are spaced, the formation of ice does not build pressure between the plug and the circuit board which would push the plug further away from the circuit board, causing electrical disconnection. Ice may and will still form on the exposed power contacts 74, but this will not cause disconnection, or damage to the printed circuit board 40 or the plug 78. As shown in FIG. 13, the printed circuit board 40 also has a separate set of contacts 82 used for programming the motor 10. These contacts 82 are aligned with a tubular port 84 formed in the cup 54 which is normally closed by a stop 86 removably received in the port. When the stop 86 is removed the port can receive a probe 88 into connection with the contacts 82 on the circuit board 40. The probe 88 is connected to a microprocessor or the like (not shown) for programming or, importantly, re-programming the operation of the motor after it is fully assembled. For instance, the speed of the motor can be changed, or the delay prior to starting can be changed. Another example in the context of refrigeration is that the motor can be re-programmed to operate on different input, such as when demand defrost is employed. The presence of the port 84 and removable stop 86 allow the motor to be re-programmed long after final assembly of the motor and installation of the motor in a given application. The port 84 is keyed so that the probe can be inserted in only one way into the port. As shown in FIG. 5, the key is manifested as a trough 90 on one side of the port 84. The probe has a corresponding ridge which is received in the trough when the probe is oriented in the proper way relative to the trough. In this way, it is not possible to incorrectly connect the probe 88 to the programming contacts. If the probe 88 is not properly oriented, it will not be received in the port 84. As shown in FIG. 2, the stator includes a stator core (or bobbin), generally indicated at 92, made of a polymeric material and a winding 94 wound around the core. The winding leads are terminated at a terminal pocket 96 formed as one piece with the stator core 92 by terminal pins 98 received in the terminal pocket. The terminal pins 98 are attached in a suitable manner, such as by soldering to the printed circuit board 40. However, it is to be understood that other ways of making the electrical connection can be used without departing from the scope of the present invention. It is envisioned that a plug-in type connection (not shown) could be used so that no soldering would be necessary. The ferromagnetic material for conducting the magnetic flux in the stator 22 is provided by eight distinct pole pieces, generally indicated at 100. Each pole piece has a generally U-shape and including a radially inner leg 100a, a radially outer leg 100b and a connecting cross piece 100c. The pole pieces 100 are each preferably formed by stamping relatively thin U-shaped laminations from a web of steel and stacking the laminations together to form the pole piece 100. The laminations are secured together in a suitable manner, such as by welding or mechanical interlock. One form of lamination (having a long radially outer leg) forms the middle portion of the pole piece 100 and another form of lamination forms the side portions. It will be noted that one pole piece (designated 100' in FIG. 2) does not have one side portion. This is done intentionally to leave a space for insertion of the Hall device 46, as described hereinafter. The pole pieces 100 are mounted on respective ends of the stator core 22 so that the radially inner leg 100a of each pole piece is received in a central opening 102 of the stator core and the radially outer leg 100b extends axially along the outside of the stator core across a portion of the winding. The middle portion of the radially outwardly facing side of the radially outer leg 100b, which is nearest to the rotor magnet 35 in the assembled motor, is formed with a notch 100d. Magnetically, the notch 100d facilitates positive location of the rotor magnet 35 relative to the pole pieces 100 when the motor is stopped. The pole pieces could also be molded from magnetic material without departing from the scope of the present invention. In certain, low power applications, there could be a single pole piece stamped from metal (not shown), but having multiple (e.g., four) legs defining the pole piece bent down to extend axially across the winding. The pole pieces 100 are held and positioned by the stator core 92 and a central locator member, generally indicated at 104. The radially inner legs 100a of the pole pieces are positioned between the central locator member 104 and the inner diameter of the stator core 92 in the central opening 102 of the stator core. Middle portions of the inner legs 100a are formed from the same laminations which make up the middle portions of the outer legs 100b, and are wider than the side portions of the inner legs. The radially inner edge of the middle portion of each pole piece inner leg 100a is received in a respective seat 104a formed in the locator member 104 to accept the middle portion of the pole piece. The seats 104a are arranged to position the pole pieces 100 asymmetrically about the locator member 104. No plane passing through the longitudinal axis of the locator member 104 and intersecting the seat 104a perpendicularly bisects the seat, or the pole piece 100 located by the seat. As a result, the gap between the radially outer legs 100b and the permanent magnet 35 of the rotor 24 is asymmetric to facilitate starting the motor. The radially outer edge of the inner leg 100a engages ribs 106 on the inner diameter of the stator core central opening 102. The configuration of the ribs 106 is best seen in FIGS. 9-11. A pair of ribs (106a, 106b, etc.) is provided for each pole piece 100. The differing angulation of the ribs 106 apparent from FIGS. 9 and 10 reflects the angular offset of the pole pieces 100. The pole pieces and central locator member 104 have been shown in phantom in FIG. 9 to illustrate how each pair is associated with a particular pole piece on one end of the stator core. One of the ribs 106d' is particularly constructed for location of the unbalanced pole piece 100', and is engageable with the side of the inner leg 100a' rather than its radially outer edge. Another of the ribs 106d associated with the unbalanced pole piece has a lesser radial thickness because it engages the radially outer edge of the wider middle portion of the inner leg 100a'. The central locator member 104 establishes the radial position of each pole piece 100. As discussed more fully below, some of the initial radial thickness of the ribs 106 may be sheared off by the inner leg 100a upon assembly to accommodate tolerances in the stator core 92, pole piece 100 and central locator member 104. The radially inner edge of each outer leg 100b is positioned in a notch 108 formed on the periphery of the stator core 92. Referring now to FIGS. 6-8, the central locator member 104 has opposite end sections which have substantially the same shape, but are angularly offset by 45° about the longitudinal axis of the central locator member (see particularly FIG. 7). The offset provides the corresponding offset for each of the four pole pieces 100 on each end of the stator core 92 to fit onto the stator core without interfering with one of the pole pieces on the opposite end. It is apparent that the angular offset is determined by the number of pole pieces 100 (i.e., 360° divided by the number of pole pieces), and would be different if a different number of pole pieces were employed. The shape of the central locator member 104 would be correspondingly changed to accommodate a different number of pole pieces 100. As shown in FIG. 8, the central locator member 104 is molded around a metal rotor shaft bearing 110 which is self lubricating for the life of the motor 10. The stator core 92, winding 94, pole pieces 100, central locator member 104 and bearing 110 are all encapsulated in a thermoplastic material to form the stator 22. The ends of the rotor shaft bearing 110 are not covered with the encapsulating material so that the rotor shaft 32 may be received through the bearing to mount the rotor 24 on the stator 22 (see FIG. 3). Method of Assembly Having described the construction of the electric motor 10, a preferred method of assembly will now be described. Initially, the component parts of the motor will be made. The precise order of construction of these parts is not critical, and it will be understood that some or all of the parts may be made a remote location, and shipped to the final assembly site. The rotor 24 is formed by placing the magnet 35 and the rotor shaft 32, having the insert 34 at one end, in a mold. The hub 28 and fan blades 30 are molded around the magnet 35 and rotor shaft 32 so that they are held securely on the hub. The housing 26 is also formed by molding the cup 54, spokes 56 and annular rim 58 as one piece. The cup 54 is formed internally with ribs 112 (FIG. 5) which are used for securing the printed circuit board 40, as will be described. The printed circuit board 40 is formed in a conventional manner by connection of the components 42 to the board. In the preferred embodiment, the programming contacts 82 and the power contacts 74 are shot into the circuit board 40, rather than being mounted by soldering (FIG. 4). The Hall device 46 is mounted on the finger 44 extending from the board and electrically connected to components 42 on the board. The stator 22 includes several component parts which are formed prior to a stator assembly. The central locator member 104 is formed by molding around the bearing 110, which is made of bronze. The ends of the bearing 110 protrude from the locator member 104. The bearing 110 is then impregnated with lubricant sufficient to last the lifetime of the motor 10. The stator core 92 (or bobbin) is molded and wound with magnet wire and terminated to form the winding 94 on the stator core. The pole pieces 100 are formed by stamping multiple, thin, generally U-shaped laminations from a web of steel. The laminations are preferably made in two different forms, as described above. The laminations are stacked together and welded to form each U-shaped pole piece 100, the laminations having the longer outer leg and wider inner leg forming middle portions of the pole pieces. However, one pole piece 100' is formed without one side portion so that a space will be left for the Hall device 46. The component parts of the stator 22 are assembled in a press fixture (not shown). The four pole pieces 100 which will be mounted on one end of the stator core 92 are first placed in the fixture in positions set by the fixture which are 90° apart about what will become the axis of rotation of the rotor shaft 32. The pole pieces 100 are positioned so that they open upwardly. The central locator member 104 and bearing 110 are placed in the fixture in a required orientation and extend through the central opening 102 of the stator core 92. The radially inner edges of the middle portions of the inner legs 100a of the pole pieces are received in respective seats 104a formed on one end of the central locator member 104. The wound stator core 92 is set into the fixture generally on top of the pole pieces previously placed in the fixture. The other four pole pieces 100 are placed in the fixture above the stator core 92, but in the same angular position they will assume relative to the stator core when assembly is complete. The pole pieces 100 above the stator core 92 open downwardly and are positioned at locations which are 45° offset from the positions of the pole pieces at the bottom of the fixture. The press fixture is closed and activated to push the pole pieces 100 onto the stator core 92. The radially inner edges of the inner legs 100a of the pole pieces 100 engage their respective seats 104a of the central locator member. The seat 104a sets the radial position of the pole piece 100 it engages. The inner legs 100a of the pole pieces 100 enter the central opening 102 of the stator core 92 and engage the ribs 106 on the stator core projecting into the central opening. The variances in radial dimensions from design specifications in the central locator member 104, pole pieces 100 and stator core 92 caused by manufacturing tolerances are accommodated by the inner legs 100a shearing off some of the material of the ribs 106 engaged by the pole piece. The shearing action occurs as the pole pieces 100 are being passed onto the stator core 92. Thus, the tolerances of the stator core 92 are completely removed from the radial positioning of the pole pieces. The radial location of the pole pieces 100 must be closely controlled so as to keep the air gap between the pole pieces and the rotor magnet 35 as small as possible without mechanical interference of the stator 22 and rotor 24. The assembled stator core 92, pole pieces 100, central locator member 104 and bearing 110 are placed in a mold and substantially encapsulated in a suitable fire resistant thermoplastic. In some applications, the mold material may not have to be fire resistant. The ends of the bearing 110 are covered in the molding process and remain free of the encapsulating material. The terminal pins 98 for making electrical connection with the winding 94 are also not completely covered by the encapsulating material (see FIG. 4). The skirt 70 and legs 36 are formed out of the same material which encapsulates the remainder of the stator. The legs 36 are preferably relatively long, constituting approximately one third of the length of the finished, encapsulated stator. Their length permits the legs 36 to be made thicker for a more robust construction, while permitting the necessary resilient bending needed for snap connection to the housing 26. In addition to the legs 36 and skirt 70, two positioning tangs 114 are formed which project axially in the same direction as the legs and require the stator 22 to be in a particular angular orientation relative to the housing 26 when the connection is made. Still further, printed circuit board supports are formed. Two of these take the form of blocks 116, from one of which project the terminal pins 98, and two others are posts 118 (only one of which is shown). The encapsulated stator 22 is then assembled with the rotor 24 to form the stator/rotor subassembly. A thrust washer 120 (FIG. 3) is put on the rotor shaft 32 and slid down to the fixed end of the rotor shaft in the hub 28. The thrust washer 120 has a rubber-type material on one side capable of absorbing vibrations, and a low friction material on the other side to facilitate a sliding engagement with the stator 22. The low friction material side of the washer 120 faces axially outwardly toward the open end of the hub 28. The stator 22 is then dropped into the hub 28, with the rotor shaft 32 being received through the bearing 110 at the center of the stator. One end of the bearing 110 engages the low friction side of the thrust washer 120 so that the hub 28 can rotate freely with respect to the bearing. Another thrust washer 122 is placed on the free end of the bearing 110 and the E clip 52 is shaped onto the end of the rotor shaft 32 so that the shaft cannot pass back through the bearing. Thus, the rotor 24 is securely mounted on the stator 22. The printed circuit board 40 is secured to the stator/rotor subassembly. The assembly of the printed circuit board 40 is illustrated in FIG. 4, except that the rotor 24 has been removed for clarity of illustration. The printed circuit board 40 is pushed between the three legs 36 of the stator 22. The finger 44 of the circuit board 40 is received in an opening 124 formed in the encapsulation so that the Hall device 46 on the end of the finger is positioned within the encapsulation next to the unbalanced pole piece 100', which was made without one side portion so that space would be provided for the Hall device. The side of the circuit board 40 nearest the stator 22 engages the blocks 116 and posts 118 which hold the circuit board at a predetermined spaced position from the stator. The terminal pins 98 projecting from the stator 22 are received through two openings 126 in the circuit board 40. The terminal pins 98 are electrically connected to the components 42 circuit board in a suitable manner, such as by soldering. The connection of the terminal pins 98 to the board 40 is the only fixed connection of the printed circuit board to the stator 22. The stator/rotor subassembly and the printed circuit board 40 are then connected to the housing 26 to complete the assembly of the motor. The legs 36 are aligned with respective channels 62 in the cup 54 and the tangs 114 are aligned with recesses 128 formed in the cup (see FIGS. 5 and 14). The legs 36 will be received in the cup 54 in only one orientation because of the presence of the tangs 114. The stator/rotor subassembly is pushed into the cup 54. The free ends of the legs 36 are beveled on their outer ends to facilitate entry of the legs into the cup 54. The cup tapers slightly toward its closed end and the legs 36 are deflected radially inwardly from their relaxed configurations when they enter the cup and as they are pushed further into it. When the catch 38 at the end of each leg clears the shoulder 64 at the inner end of the channel 62, the leg 36 snaps radially outwardly so that the catch engages the shoulder. The leg 36 is still deflected from its relaxed position so that it is biased radially outwardly to hold the catch 38 on the shoulder 64. The engagement of the catch 38 with the shoulder 64 prevents the stator/rotor subassembly, and printed circuit board 40 from being withdrawn from the cup 54. The motor 10 is now fully assembled, without the use of any fasteners, by snap together construction. The printed circuit board 40 is secured in place by an interference fit with the ribs 112 in the cup 54. As the stator/rotor assembly advances into the cup 54, peripheral edges of the circuit board 40 engage the ribs 112. The ribs are harder than the printed circuit board material so that the printed circuit board is partially deformed by the ribs 112 to create the interference fit. In this way the printed circuit board 40 is secured in place without the use of any fasteners. The angular orientation of the printed circuit board 40 is set by its connection to the terminal pins 98 from the stator 22. The programming contacts 82 are thus aligned with the port 84 and the power contacts 74 are aligned with the plug receptacle 76 in the cup 54. It is also envisioned that the printed circuit board 40 may be secured to the stator 22 without any interference fit with the cup 54. For instance, a post (not shown) formed on the stator 22 may extend through the circuit board and receive a push nut thereon against the circuit board to fix the circuit board on the stator. In the preferred embodiment, the motor 10 has not been programmed or tested prior to the final assembly of the motor. Following assembly, a ganged connector (not shown, but essentially a probe 88 and a power plug 78) is connected to the printed circuit board 44 through the port and plug receptacle 76. The motor is then programmed, such as by setting the speed and the start delay, and tested. If the circuit board 40 is found to be defective, it is possible to non-destructively disassemble the motor and replace the circuit board without discarding other parts of the motor. This can be done be inserting a tool (not shown) into the openings 66 in the closed end of the cup 54 and prying the catches 38 off the shoulders 64. If the motor passes the quality assurance tests, the stop 86 is placed in the port 84 and the motor is prepared for shipping. It is possible with the motor of the present invention, to re-program the motor 10 after it has been shipped from the motor assembly site. The end user, such as a refrigerated case manufacturer, can remove the stop 86 from the port 84 and connect the probe 88 to the programming contacts 82 through the port. The motor can be re-programmed as needed to accommodate changes made by the end user in operating specifications for the motor. The motor 10 can be installed, such as in a refrigerated case, by inserting fasteners (not shown) through the openings 60 in the annular rim 58 and into the case. Thus, the housing 26 is capable of supporting the entire motor through connection of the annular rim 58 to a support structure. The motor is connected to a power source by plugging the plug 78 into the plug receptacle 76 (FIG. 14). Detents 130 (only one is shown) on the sides of the plug 78 are received in slots on respective sides of a tongue 132 to lock the plug in the plug receptacle 76. Prior to engaging the printed circuit board 40, the plug 78 engages the locating tabs 80 in the plug receptacle 76 so that in its fully inserted position, the plug is spaced from the printed circuit board. As a result, the power contacts 74 are inserted far enough into the plug 78 to make electrical connection, but are not fully received in the plug. Therefore, although ice can form on the power contacts 74 in the refrigerated case environment, it will not build up between the plug 78 and the circuit board 40 causing disconnection and/or damage. FIG. 16 is a block diagram of the microprocessor controlled single phase motor 500 according to the invention. The motor 500 is powered by an AC power source 501. The motor 500 includes a stator 502 having a single phase winding. The direct current power from the source 501 is supplied to a power switching circuit via a power supply circuit 503. The power switching circuit may be any circuit for commutating the stator 502 such as an H-bridge 504 having power switches for selectively connecting the dc power source 501 to the single phase winding of the stator 502. A permanent magnet rotor 506 is in magnetic coupling relation to the stator and is rotated by the commutation of the winding and the magnetic field created thereby. Preferably, the motor is an inside-out motor in which the stator is interior to the rotor and the exterior rotor rotates about the interior stator. However, it is also contemplated that the rotor may be located within and internal to an external stator. A position sensor such as a hall sensor 508 is positioned on the stator 502 for detecting the position of the rotor 506 relative to the winding and for providing a position signal via line 510 indicating the detected position of the rotor 506. Reference character 512 generally refers to a control circuit including a microprocessor 514 responsive to and receiving the position signal via line 510. The microprocessor 514 is connected to the H-bridge 504 for selectively commutating the power switches thereof to commutate the single phase winding of the stator 502 as a function of the position signal. Voltage VDD to the microprocessor 514 is provided via line 516 from the power supply circuit 503. A low voltage reset circuit 518 monitors the voltage VDD on line 516 and applied to the microprocessor 514. The reset circuit 518 selectively resets the microprocessor 514 when the voltage VDD applied to the microprocessor via line 516 transitions from below a predetermined threshold to above the predetermined threshold. The threshold is generally the minimum voltage required by the microprocessor 514 to operate. Therefore, the purpose of the reset circuit 518 is to maintain operation and re-establish operation of the microprocessor in the event that the voltage VDD supplied via line 516 drops below the preset minimum required by the microprocessor 514 to operate. Optionally, to save power, the hall sensor 508 may be intermittently powered by a hall strobe 520 controlled by the microprocessor 514 to pulse width modulate the power applied to the hall sensor. The microprocessor 514 has a control input 522 for receiving a signal which affects the control of the motor 500. For example, the signal may be a speed select signal in the event that the microprocessor is programmed to operate the rotor such that the stator is commutated at two or more discrete speeds. Alternatively, the motor may be controlled at continuously varying speeds or torques according to temperature. For example, in place of or in addition to the hall sensor 508, an optional temperature sensor 524 may be provided to sense the temperature of the ambient air about the motor. This embodiment is particularly useful when the rotor 506 drives a fan which moves air through a condenser for removing condenser generated heat or which moves air through an evaporator for cooling, such as illustrated in FIGS. 1-15. In one embodiment, the processor interval clock corresponds to a temperature of the air moving about the motor and for providing a temperature signal indicating the detected temperature. For condenser applications where the fan is blowing air into the condenser, the temperature represents the ambient temperature and the speed (air flow) is adjusted to provide the minimum needed air flow at the measured temperature to optimize the heat transfer process. When the fan is pulling air over the condenser, the temperature represents ambient temperature plus the change in temperature (Δt) added by the heat removed from the condenser by the air stream. In this case, the motor speed is increased in response to the higher combined temperature (speed is increased by increasing motor torque, i.e., reducing the power device off time PDOFFTIM; see FIG. 26). Additionally, the speed the motor could be set for different temperature bands to give different air flow which would be distinct constant air flows in a given fan static pressure condition. Likewise, in a condenser application, the torque required to run the motor at the desired speed represents the static load on the motor. The higher static loads can be caused by installation in a restricted environment, i.e., a refrigerator installed as a built-in, or because the condenser air flow becomes restricted due to dust build up or debris. Both of these conditions may warrant an increased air flow/speed. Similarly, in evaporator applications, the increased static pressure could indicate evaporator icing or increased packing density for the items being cooled. In one of the commercial refrigeration applications, the evaporator fan pulls the air from the air curtain and from the exit air cooling the food. This exhaust of the fan is blown through the evaporator. The inlet air temperature represents air curtains and food exit air temperature. The fan speed would be adjusted appropriately to maintain the desired temperature. Alternatively, the microprocessor 514 may commutate the switches at a variable speed rate to maintain a substantially constant air flow rate of the air being moved by the fan connected to the rotor 506. In this case, the microprocessor 514 provides an alarm signal by activating alarm 528 when the motor speed is greater than a desired speed corresponding to the constant air flow rate at which the motor is operating. As with the desired torque, the desired speed may be determined by the microprocessor as a function of an initial static load of the motor and changes in static load over time. FIG. 23 illustrates one preferred embodiment of the invention in which the microprocessor 514 is programmed according to the flow diagram therein. In particular, the flow diagram of FIG. 23 illustrates a mode in which the motor is commutated at a constant air flow rate corresponding to a speed and torque which are defined by tables which exclude resonant points. For example, when the rotor is driving a fan for moving air over a condenser, the motor will have certain speeds at which a resonance will occur causing increased vibration and/or increased audio noise. Speeds at which such vibration and/or noise occur are usually the same or similar and are predictable, particularly when the motor and its associated fan are manufactured to fairly close tolerances. Therefore, the vibration and noise can be minimized by programming the microprocessor to avoid operating at certain speeds or within certain ranges of speeds in which the vibration or noise occurs. As illustrated in FIG. 23, the microprocessor 514 would operate in the following manner. After starting, the microprocessor sets the target variable I to correspond to an initial starting speed pointer defining a constant air flow rate at step 550. For example, I=0. Next, the microprocessor proceeds to step 552 and selects a speed set point (SSP) from a table which correlates each of the variable levels 0 to n to a corresponding speed set point (SSP), to a corresponding power device off time (PDOFFTIM=P min ) for minimum power and to a corresponding power device off time (PDOFFTIM=P max ) for maximum power. It is noted that as the PDOFFTIM increases, the motor power decreases since the controlled power switches are off for longer periods during each commutation interval. Therefore, the flow chart of FIG. 23 is specific to this approach. Others skilled in the art will recognize other equivalent techniques for controlling motor power. After a delay at step 554 to allow the motor to stabilize, the microprocessor 514 selects a PDOFFTIM for a minimum power level (P min ) from the table which provides current control by correlating a minimum power level to the selected level of variable I. At step 558 the microprocessor selects a PDOFFTIM for a maximum power level (P max ) from the table which provides current control by correlating a maximum power level to the selected variable level I. At step 560, the microprocessor compares the actual PDOFFTIM representing the actual power level to the minimum PDOFFTIM (P min ) for this I. If the actual PDOFFTIM is greater than the minimum PDOFFTIM (PDOFFTIM>P min ), the microprocessor proceeds to step 562 and compares the variable level I to a maximum value n. If I is greater or equal to n, the microprocessor proceeds to step 564 to set I equal to n. Otherwise, I must be less than the maximum value for I so the microprocessor 514 proceeds to step 566 to increase I by one step. If, at step 560, the microprocessor 514 determines that the actual PDOFFTIM is less than or equal to the minimum PDOFFTIM (PDOFFTIM≦P min ), the microprocessor proceeds to step 568 and compares the actual PDOFFTIM representing the actual power level to the maximum PDOFFTIM (P max ) for this I. If the actual PDOFFTIM is less than the maximum PDOFFTIM (PDOFFTIM<P max ), the microprocessor proceeds to step 570 and compares the variable level I to a minimum value 0. If I is less or equal to 0, the microprocessor proceeds to step 572 to set I equal to 0. Otherwise, I must be greater than the minimum value for I so the microprocessor 514 proceeds to step 574 to decrease I by one step. If the actual PDOFFTIM is less than or equal to the minimum and is greater than or equal to the maximum so that the answer to both steps 560 and 568 is no, the motor is operating at the speed and power needed to provide the desired air flow so the microprocessor returns to step 552 to maintain its operation. Alternatively, the microprocessor 514 may be programmed with an algorithm which defines the variable rate at which the switches are commutated. This variable rate may vary continuously between a preset range of at least a minimum speed S min and not more than a maximum speed S max except that a predefined range of speeds S1±S2 is excluded from the preset range. As a result, for speeds between S1-S2 and S1, the microprocessor operates the motor at S1-S2 and for speeds between S1 and S1+S2, the microprocessor operates the motor at speeds S1+S2. FIG. 22 is a schematic diagram of the H-bridge 504 which constitutes the power switching circuit having power switches according to the invention, although other configurations may be used, such as two windings which are single ended or the H-bridge configuration of U.S. Pat. No. 5,859,519, incorporated by reference herein. The dc input voltage is provided via a rail 600 to input switches Q1 and Q2. An output switch Q3 completes one circuit by selectively connecting switch Q2 and stator 502 to a ground rail 602. An output switch Q4 completes another circuit by selectively connecting switch Q1 and stator 502 to the ground rail 602. Output switch Q3 is controlled by a switch Q5 which receives a control signal via port BQ5. Output switch Q4 is controlled by a switch Q8 which receives a control signal via port BQ8. When switch Q3 is closed, line 604 pulls the gate of Q1 down to open switch Q1 so that switch Q1 is always open when switch Q3 is closed. Similarly, line 606 insures that switch Q2 is open when switch Q4 is closed. The single phase winding of the stator 502 has a first terminal F and a second terminal S. As a result, switch Q1 constitutes a first input switch connected between terminal S and the power supply provided via rail 600. Switch Q3 constitutes a first output switch connected between terminal S and the ground rail 602. Switch Q2 constitutes a second input switch connected between the terminal F and the power supply provided via rail 600. Switch Q4 constitutes a second output switch connected between terminal F and ground rail 602. As a result, the microprocessor controls the first input switch Q1 and the second input switch Q2 and the first output switch Q3 and the second output switch Q4 such that the current through the motion is provided during the first 90° of the commutation period illustrated in FIG. 27. The first 90° is significant because of noise and efficiency reasons and applies to this power device topology (i.e., either Q1 or Q2 is always "on" when either Q3 or Q4 is off, respectively. PDOFFTIM is the term used in the software power control algorithms. When the first output switch Q3 is open, the first input switch Q1 is closed. Similarly, the second input switch Q2 is connected to and responsive to the second output switch Q4 so that when the second output switch Q4 is closed, the second input switch Q2 is open. Also, when the second output switch Q4 is open, the second input switch Q2 is closed. This is illustrated in FIG. 27 wherein it is shown that the status of Q1 is opposite the status of Q3 and the status of Q2 is opposite the status of Q4 at any instant in time. FIG. 26 is a timing flow chart illustrating the start up mode with a current maximum determined by the setting of PDOFFTIM versus the motor speed. In this mode, the power devices are pulse width modulated by software in a continuous mode to get the motor started. The present start algorithm stays in the start mode eight commutations and then goes into the RUN mode. A similar algorithm could approximate constant acceleration by selecting the correct settings for PDOFFTIM versus speed. At step 650, the value HALLIN is a constant defining the starting value of the Hall device reading. When the actual Hall device reading (HALLOLD) changes at step 652, HALLIN is set to equal HALLOLD at step 654 and the PDOFFTIM is changed at step 656 depending on the RPMs. FIG. 25 illustrates the microprocessor outputs (BQ5 and BQ8) that control the motor when the strobed hall effect output (HS3) changes state. In this example, BQ5 is being pulse width modulated while HS3 is 0. When HS3 (strobed) changes to a 1, there is a finite period of time (LATENCY) for the microprocessor to recognize the magnetic change after which BQ5 is in the off state so that BQ8 begins to pulse width modulate (during PWMTIM). FIG. 24 illustrates another alternative aspect of the invention wherein the microprocessor operates within a run mode safe operating area without the need for current sensing. In particular, according to FIG. 24, microprocessor 514 controls the input switches Q1-Q4 such that each input switch is open or off for a minimum period of time (PDOFFTIM) during each pulse width modulation period whereby over temperature protection is provided without current sensing. Specifically, the minimum period may be a function of the speed of the rotor whereby over temperature protection is provided without current sensing by limiting the total current over time. As illustrated in FIG. 24, if the speed is greater than a minimum value (i.e., if A<165), A is set to 165 and SOA limiting is bypassed and not required; if the speed is less than (or equal to) a minimum value (i.e., if A≧165), the routine of FIG. 24 ensures that the switches are off for a minimum period of time to limit current. "A" is a variable and is calculated by an equation that represents a PDOFFTIM minimum value at a given speed (speed is a constant multiplied by 1/TINPS, where TINPS is the motor period). Then, if PDOFFTIM is <A, PDOFFTIM is set to A so that the motor current is kept to a maximum desired value at the speed the motor is running. As illustrated in FIG. 18, the motor includes a reset circuit 512 for selectively resetting the microprocessor when a voltage of the power supply vdd transitions from below a predetermined threshold to above a predetermined threshold. In particular, switch Q6 disables the microprocessor via port MCLR/VPP when the divided voltage between resistors R16 and R17 falls below a predetermined threshold. The microprocessor is reactivated and reset when the voltage returns to be above the predetermined threshold thereby causing switch Q6 to close. FIG. 19 illustrates one preferred embodiment of a strobe circuit 520 for the hall sensor 508. The microprocessor generates a pulse width modulated signal GP5 which intermittently powers the hall sensor 508 as shown in FIG. 21 by intermittently closing switch Q7 and providing voltage VB2 to the hall sensor 508 via line HS1. FIG. 17 is a schematic diagram of the power supply circuit 503 which supplies the voltage V in for energizing the stator single phase winding via the H-bridge 504 and which also supplies various other voltages for controlling the H-bridge 504 and for driving the microprocessor 514. In particular, the lower driving voltages including VB2 for providing control voltages to the switches Q1-Q4, VDD for driving the microprocessor, HS2 for driving the hall sensor 508, and VSS which is the control circuit reference ground not necessarily referenced to the input AC or DC voltage are supplied from the input voltage V in via a lossless inline series capacitor C1. FIG. 20 illustrates the inputs and outputs of microprocessor 514. In particular, only a single input GP4 from the position sensor is used to provide information which controls the status of control signal BQ5 applied to switch Q5 to control output switch Q3 and input switch Q1 and which controls the status of control signal BQ8 applied to switch Q8 to control output switch Q4 and input switch Q2. Input GP2 is an optional input for selecting motor speed or other feature or may be connected for receiving a temperature input comparator output when used in combination with thermistor 524. FIG. 28 illustrates a flow chart of one preferred embodiment of a run mode in which the power devices are current controlled. In this mode, the following operating parameters apply: Motor Run Power Device (Current) Control At the end of each commutation, the time power devices will be off the next time the commutation period is calculated. OFFTIM=TINP/2. (The commutation period divided by 2=90°). While in the start routine, this is also calculated. After eight commutations (1 motor revolution) and at the start routine exit, PWMTIM is calculated: PWMTIM=OFFTIM/4 At the beginning of each commutation period, a counter (COUNT8) is set to five to allow for four times the power devices will be turned on during this commutation: PWMSUM=PWMTIM PDOFFSUM=PWMTIM-PDOFFTIM TIMER=0 (PDOFFTIM is used to control the amount of current in the motor and is adjusted in the control algorithm (SPEED, TORQUE, CFM, etc.) Commutation time set to 0 at each strobed hall change, HALLOLD is the saved hall strobe value. During motor run, the flow chart of FIG. 28 is executed during each commutation period. In particular at step 702, the commutation time is first checked to see if the motor has been in this motor position for too long a period of time, in this case 32 mS. If it has, a locked rotor is indicated and the program goes to the locked rotor routine at step 704. Otherwise, the program checks to see if the commutation time is greater then OFFTIM at step 706; if it is, the commutation period is greater than 90 electrical degrees and the program branches to step 708 which turns the lower power devices off and exits the routine at step 710. Next, the commutation time is compared at step 712 to PWMSUM. If it is less than PWMSUM, the commutation time is checked at step 714 to see if it is less or equal to PDOFFSUM where if true, the routine is exited at step 716; otherwise the routine branches to step 708 (if step 714 is yes). For the other case where the commutation time is greater or equal to PWMSUM, at step 718 PWMSUM and PDOFFSUM have PWMTIM added to them to prepare for the next pulse width modulation period and a variable A is set to COUNT 8-1. If A is equal to zero at step 720, the pulse width modulations (4 pulses) for this commutation period are complete and the program branches to step 708 to turn the lower power devices off and exit this routine. If A is not equal to zero, COUNT8 (which is a variable defining the number of PWMs per commutation) is set to A at step 722; the appropriate lower power device is turned on; and this routine is exited at step 716. More PWM counts per commutation period can be implemented with a faster processor. Four (4) PWMs per commutation period are preferred for slower processors whereas eight (8) are preferred for faster processors. The timing diagram for this is illustrated in FIG. 27. In the locked rotor routine of step 704, on entry, the lower power devices are turned off for 1.8 seconds after which a normal start attempt is tried. In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

An electric motor having a snap-together construction without the use of separate fasteners. The construction of the motor removes additive tolerances for a more accurate assembly. The motor is capable of programming and testing after final assembly and can be non-destructively disassembled for repair or modification. The motor is constructed to inhibit the ready entry of water into the motor housing and to limit the effect of any water which manages to enter the housing.

PRIORITY TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/788,250, filed Mar. 31, 2006, which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION Several examples of utilizing peritoneal (ascites) tumor growth to assess the activity of chemotherapeutics have been reported in the literature, including one that utilized LOX melanoma cells. For example, R. H. Shoemaker et al., Proc. Am. Assoc. Cancer Res., 26:330 (1985), reported that LOX melanoma cells could form ascites, and that the model could be used to assess cancer therapeutics by using a survival endpoint around day 20. In 2003, H. Nakanishi et al., Cancer Sci., 94:112-118 (2003), reported a peritoneal model utilizing gastric cancer cells tagged with GFP. This model was used to study the chemosensitivity of peritoneal cell growth to an anti-cancer agent. Tumor burden was measured by harvesting GFP cells from the peritoneal cavity, homogenizing the cells, centrifuging cells at 10000 g, and then measuring the fluorescence of the supernatant using a fluorescence counter. In order to extrapolate the number of cells that produced the fluorescence, a calibration curve was used with a standard number of GFP cells. In this model, >1 month was needed for ascites production in the peritoneum. Several examples of utilizing metastatic tumor growth to assess the activity of chemotherapeutics have been reported in the literature. The LOX experimental metastasis model was reported by O. Fodstad et al., Int. J. Cancer, 41:442-449 (1988), by R. H. Shoemaker et al. in 1991, and by M. Yeng et al., Clin. Cancer Res., 5:3549-3559, (1999) with GFP-tagged cells. For example, Fodstad et al. reported that LOX cells injected into the tail vein of immunocompromised mice were able to metastasize to lung with nearly 100% frequency. The size and number of colonies differed from one animal to another however, and thus the authors found it was not possible to establish an accurate relationship between the cell number injected and resulting colony number. For this reason, they used animal survival as an endpoint rather than counting metastatic colonies on the lungs. In a report by R. H. Shoemaker et al. 1991, LOX-L cells were generated by 16 cycles of subcutaneous (sc) tumor transplantation, followed by removal of a lung metastasis for growth in vitro. Unlike the parental cell line LOX, the LOX-L cell line was able to metastasize to lung from sc tumor implantation, whereas LOX cells could only metastasize from iv implantation. LOX-L sc tumors were utilized to study the effects of chemotherapeutics on metastasis, however the authors went through the very arduous procedure of transplanting metastatic lungs into new mice for evaluation of pulmonary metastases. In subsequent studies (Wang X et al., Int. J. Cancer, 112:994-1002, 2004) the LOX-L model was implanted iv, however metastases were evaluated simply by counting colonies and utilizing a survival endpoint. In a report by M. Yeng et al., Clin. Cancer Res., 5:3549-4559 (1999), metastasis models were established utilizing GFP tagged LOX or B16 melanoma cells. For the LOX-GFP model, tumors were implanted orthotopically (transdermally), whereas for B16 GFP model, cells were implanted iv. GFP was used to identify lung metastases, however the authors failed to quantify the lung metastatic tumor burden, and instead used a subjective (qualitative) endpoint. They simply visualized metastases in live animals or upon necropsy by utilizing a fluorescent microscope to establish the presence or absence of metastases. SUMMARY OF THE INVENTION The human melanoma cell line LOX can induce either ascites when tumor cells are implanted intra-peritoneally, or lung metastasis when inoculated intravenously. The ascites model can be used as a fast drug-screening model, whereas the lung metastasis model may be useful to evaluate anti-metastatic agents. In both models, quantitative analysis of tumor growth and efficacy has been a challenge due to difficulties in assessing tumor burden. To resolve this issue, the present invention provides LOX cells transfected with GFP (called LOX-GFP), and this marker was utilized to analyze tumor burden in ascites or in lung. For the ascites model, 10×10 6 LOX-GFP cells were inoculated intra-peritoneally in Nu/Nu mice, and ascites were harvested after 7 days. Ascites was visualized under a fluorescence microscope and relative fluorescence was quantitated utilizing Acumen Explorer. Anti-proliferative efficacy in this model was validated using a cytotoxic agent, Taxol, as well as some development compounds. For the lung metastasis model, a new cell line called LOX-GFP-LM was established; this cell line was isolated from a lung metastasis colony in mice which was induced through intravenous inoculation of LOX-GFP cells. The LOX-GFP-LM cell line reproducibly colonizes lung 25-30 days post IV inoculation of 2×10 6 cells. Lungs were harvested and visualized under a fluorescence microscope, and the relative fluorescence of homogenized lung suspension was assessed utilizing Acumen Explorer. Anti-metastatic efficacy was validated in this model utilizing two development compounds previously shown to have broad and potent anti-tumor activity in traditional subcutaneous xenograft studies. To compare two new cell lines (LOX-GFP and LOX-GFP-LM) with the parental cell line (LOX), gene array analysis and tumor histopathology were characterized. The present invention provides application of GFP to two human melanoma LOX models in mice, resulting in better quantitative tumor burden assessment and improved efficacy evaluation. These improved models should provide a feasible alternative for ascites or experimental metastasis evaluation of novel cancer therapeutics. The present invention provides a method of evaluating whether a tumor metastasizes which comprises injecting GFP-expressing tumor cells intravenously into an athymic mouse, such as a nude or SCID mouse, followed by sacrificing the mouse and removing one or more tissues to be evaluated. The removed tissue is homogenized, and the level of GFP in the homogenized sample quantified using laser-scanning fluoroscopy, e.g. an Acumen Explorer. The present invention also provides a method for evaluating a candidate drug or protocol for the inhibition of metastasis of a tumor which comprises injecting an athymic mouse intravenously with GFP-expressing tumor cells and administering a candidate drug or protocol to the mouse. The mouse is then sacrificed and one or more tissues removed for evaluation of metastasis inhibition. The removed tissue is homogenized and the level of GFP in a homogenized sample of the tissue quantified using laser-scanning fluoroscopy. The GFP level is compared to the level of GFP in a homogenized sample from a control animal which has not been treated with the candidate drug or protocol. A decreased level of GFP in the treated sample as compared to the control sample denotes inhibition of metastasis. The present invention further provides a method for evaluating a candidate drug or protocol for the treatment of a tumor which comprises injecting an athymic mouse intraperitoneally with GFP-expressing tumor cells and administering a candidate drug or protocol to the mouse. Ascites or an organ containing the tumor is removed for evaluation and the level of GFP in a sample of the ascites of homogenized tissue is quantified using laser-scanning fluoroscopy. The level of GFP in the ascites or homogenized sample is then compared to that from a control animal which has not been treated with the candidate drug or protocol. A decreased level of GFP in the treated sample as compared to the control sample denotes that the candidate drug or protocol is useful in the treatment of said tumor. The present invention provides a method of enhancing the propensity of a tumor cell line to metastasize to a particular tissue which comprises injecting an athymic mouse intraperitoneally with tumor cells that express GFP, removing the ascites formed in the mouse and injecting it intravenously into another athymic mouse. The mouse is sacrificed, and the tissue to which metastasis is to be enhanced is removed. GFP-expressing tumor cells are then recovered from the removed tissue, cultured in vitro, and injected into an athymic mouse, where the cultured tumor cells metastasize to the tissue from which the cells were recovered to a greater degree than the original GFP-expressing tumor cells. The present invention further provides a LOX-GFP-LM cell line which metastasizes to lung to a greater degree than the parental LOX-GFP cell line. This cell line provides advantages in the assays described herein. DESCRIPTION OF THE FIGURES FIG. 1 illustrates the morphology of LOX, LOX-GFP, and LOX-GFP-LM tumors in SCID beige mice. FIGS. 2A through 2M show Affymetrix microarray data isolated from LOX, LOX-GFP, and LOX-GFP-LM cells demonstrating the effect of these cells on the indicated genes. FIG. 3 indicates the relative fluorescence units (RFU) of ascites samples for [4-Amino-2-(1-methanesulfonyl-piperidin-4-ylamino)-pyrimidin-5-yl]-(2,3-difluoro-6-methoxy-phenyl)-methanone (Compound A) run on an Acumen Explorer. FIG. 4 depicts the relative fluorescence units (RFU) of ascites samples for 4-[4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound B) and 5-(4-Ethoxy-quinolin-6-ylmeth-(Z)-ylidine)-2-(2-hydroxy-1-(R)-phenyl-ethylamino)-thiazol-4-one (Compound C) run on an Acumen Explorer. FIG. 5 depicts the relative fluorescence units (RFU) of ascites samples for 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D) and for the combination of Taxol and Compound D run on an Acumen Explorer. FIG. 6 illustrates the percent fluorescent intensity of ascites samples from Nu/Nu mice treated with [4-Amino-2-(1-methanesulfonyl-piperidin-4-ylamino)-pyrimidin-5-yl]-(2,3-difluoro-6-methoxy-phenyl)-methanone (Compound A) as compared to Vehicle control group. FIG. 7 illustrates the percent fluorescent intensity of ascites samples from Nu/Nu mice treated with 4-[4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound B) or 5-(4-Ethoxy-quinolin-6-ylmeth-(Z)-ylidine)-2-(2-hydroxy-1-(R)-phenyl-ethylamino)-thiazol-4-one (Compound C) as compared to Vehicle control group. FIG. 8 illustrates the percent fluorescent intensity of ascites samples from Nu/Nu mice treated with 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D) or with the combination of Taxol and Compound D as compared to Vehicle control group. FIG. 9 provides photographs of lung homogenate sample wells of mice treated with 3-methyl-5-(2-chlorophenyl)-7-amino-pyrazolo[3,4][1,4]benzodiazepine (Compound E). Lungs were harvested at day 25 post-implantation (2×10 6 cell/mouse iv) and homogenized and determined run on an Acumen Explorer. FIG. 10 provides photographs of lung homogenate sample wells of mice treated with 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D). Lungs were harvested at day 26 post-implantation (2×10 6 cell/mouse iv) and homogenized and determined run on an Acumen Explorer. FIG. 11 depicts the relative fluorescence units (RFU) of metastatic lung tissue from SCID beige mice treated with 3-methyl-5-(2-chlorophenyl)-7-amino-pyrazolo[3,4][1,4]benzodiazepine (Compound E) as compared to Vehicle group. FIG. 12 depicts the relative fluorescence units (RFU) of metastatic lung tissue from SCID beige mice treated with 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D) as compared to Vehicle group. FIG. 13 provides Kaplan-Meier survival curves of SCID beige mice, implanted with LOX-GFP-LM cells, that were treated with 3-methyl-5-(2-chlorophenyl)-7-amino-pyrazolo[3,4][1,4]benzodiazepine (Compound E). FIG. 14 provides Kaplan-Meier survival curves of SCID beige mice, implanted with LOX-GFP-LM cells, that were treated with 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D). FIG. 15 is a simple schematic of the crucial portions of a pCMV-tag 5A plasmid containing GFP and Neo. FIG. 16 ( a - i ) depicts the restriction map for the GFP expression vector. FIG. 17 provides photographs of lung homogenate sample wells of mice injected either with LOX-GFP or with LOX-GFP-LM tumor lines. Lungs were harvested at 14, 21, and 28 days post-injection. FIG. 18 compares LOX-GFP-LM and LOX-GFP-induced experimental lung metastasis in SCID mice. Samples were measured on a 96 well plate with Acumen Explorer. FIG. 19 provides Kaplan-Meier survival curves both LOX-GFP and LOX-GFP-LM tumor lines in SCID beige mice. DETAILED DESCRIPTION OF THE INVENTION The present invention provides several key modifications over the LOX peritoneal (ascites) models previously used to produce a model having a much shorter duration than those previously employed. The present model allows for rapid quantification of cell number as an endpoint. Although the duration for previous studies was fairly short at only 20 days, the current model does not rely on survival as the sole endpoint, and can be completed in as little as 7 days. The current model utilizes cells tagged with GFP, however the method of ascites quantification has been improved by eliminating the homogenization and centrifugation steps. The process of the invention directly measures cell number from ascites using the Acumen Explorer. The present invention provides significant improvements to the LOX experimental metastasis models described previously by stably transfecting GFP into the cells, so that lungs can be removed and metastatic tumor burden can be accurately quantified by measuring fluorescence. This method reduces reliance on survival as an endpoint (although it may sometimes be monitored when scientifically relevant). The model of the present invention utilizes an experimental metastatic model using iv implantation of LOX cells rather than using LOX-L cells. Additionally, metastases is quantified using GFP-tagged cells rather than relying on colony counts and survival, as those methods are not accurate enough to discern small differences in metastatic tumor burden. In the model of the invention, the metastatic tumor burden is quantified in order to accurately assess the anti-metastatic capability of experimental therapeutics using various treatment schedules. Therefore the step of visualizing metastases in vivo was omitted in favor of removing the lungs, homogenizing them, and measuring the relative fluorescence of lungs from vehicle treated Vs. therapeutic treated mice. In one aspect, the present invention provides a stable clone of the LOX melanoma cell line expressing green fluorescent protein (GFP) and an assay for evaluating the anti-tumor efficacy of potential clinical candidate therapeutics, i.e. drugs and protocols, in vivo. In particular, the invention provides two different in vivo models; 1) a short (7-10 day) peritoneal (ascites) model for rapid screening of compounds for efficacy, and 2) an experimental metastasis model for assessment of the anti-metastatic capabilities of novel cancer therapeutics. In another aspect, the present invention provides a peritoneal (ascites) model for rapid screening of the anti-tumor efficacy of potential cancer clinical candidate therapeutics in vivo. The model is unique in that it provides efficacy data in as little as 7 days and provides quantitative rather than qualitative data. In still another aspect, the present invention provides an experimental metastasis model for evaluating the anti-metastatic efficacy of potential cancer clinical candidate therapeutics in vivo. The model is unique in that it provides quantified data regarding metastatic tumor burden rather than relying on survival as the sole endpoint. Bicistronic construct denotes a mammalian expression vector containing two genes inserted into expression vector. Bicistronic GFP construct denotes a mammalian expression vector, preferably pCMV-tag 5A (Stratagene, Genbank accession number AF076312), which has been modified to contain a nucleotide sequence encoding a GFP molecule, preferably GFP from Renilla mullerei , and a nucleotide sequence encoding Neo (Neomycin resistant gene) for G418 selection. A spontaneous metastasis model is one in which a primary tumor is established in an animal and is allowed to grow and spread to secondary sites without any manipulation or intervention. This process requires that the cells from the primary tumor gain entry into the circulatory system through their natural capability, and then seed and grow in distant sites. An experimental metastasis model is one in which a primary tumor is not established. Cells are directly injected into the circulatory system to mimic the seeding and growth process of metastasis to distant sites. Green Fluorescent Protein (GFP) is a luminescent protein produced by species of soft coral. GFP can be obtained from a variety of different sources, including Renilla mullerei, Renilla reniformis, Renilla kollikeri Aeruorea victoria . While any GFP molecule can be used in the present invention, the preferred GFP is from Renilla mullerei. LOX-GFP cell line is a cell line created by transfection of LOX melanoma cells obtained from National Cancer Institute (NCI) with the bicistronic GFP construct described above. LOX-GFP-LM cell line is a cell line created by injecting athymic mice intraperitoneally with LOX-GFP cells, removing ascites containing LOX-GFP cells from the mice, injecting said ascites intravenously into mice, collecting the resultant metastatic lungs from the mice, and culturing colonies of GFP-expressing tumor cells recovered from the metastatic lung tissue in vitro. Tumor cells that stably express green fluorescent protein can be prepared in the following manner. Tumor cells from an established tumor cell line can be transfected in a conventional manner with a bicistronic GFP construct prepared in accordance with the procedure in Example 1. For example, Fugene, a multi-component lipid-based (non-liposomal) transfection reagent (Roche Molecular Diagnostics) can be added to a serum free medium, such as RPMI1640, followed by addition of the bicistronic GFP construct. While the ratio of Fugene to construct can vary, the ratio is advantageously 3:1. The sample is incubated, for example at room temperature, for a period of about 30 minutes, and the mixture transferred to a flask of tumor cells. The tumor cells are present in culture at a ration of about 80%. The cells are incubated for a period of about 6 hours, followed by removal of the incubation medium and addition of a selection medium containing 1% Geneticin (G418). Selection for G418 resistance will take a few weeks, for example 3 to 6 weeks, after which the cells are sorted for those which show the greatest GFP expressions. The top 5% GFP expressing cell population are then selected, isolated, grown up, and further sorted to obtain cells having 100% GFP expression. Tumor cells that metastasize to a particular tissue more aggressively than the corresponding parental tumor cell line can be prepared in the following manner. Athymic mice are implanted, preferably intra-peritoneally (ip), with approximately 10 to 20 million GFP-expressing tumor cells each. After about 10 to 14 days, ascites fluid containing the GFP-expressing tumor cells is harvested from the mice, and the ascites diluted with PBS. The ascites/PBS solution is filtered through a 40 μm nylon cell strainer and centrifuged at about 1500 rpm. Pelleted cells are resuspended in PBS and counted to achieve the desired cell concentration. Athymic mice are then transplanted intravenously (iv), for example via the tail vein, with the GFP-expressing tumor cells isolated from ascites (above). The cells are preferably transplanted at a concentration between about 1×10 6 cell/mouse and about 2×10 6 cell/mouse. Once the mice are moribund or dead, the tissue of interest, for example lung or breast tissue, is isolated and examined under a fluorescence stereomicroscope to see potential micro-metastases. Colonies of GFP-expressing tumor cells which show very strong expression are recovered from the tissue, for example by gentle dissection. The colonies can then be ground on sterile metal gauze (#40), washed with 2-3 ml culture medium, and centrifuged at about 1500 rpm. The cell pellets can then be washed in a serum free medium, such as RPMI1640 culture medium which preferably contains about 10% penicillin/streptomycin and about 10% fetal bovine serum (FBS). The cells are seeded into flasks of RPMI1640 medium containing about 10% FBS and about 2% penicillin/streptomycin. The cells are routinely passaged in selection medium containing G418 to remove any mouse cell contaminants. After several, preferably 2-3, passages, cultures can be scaled up and frozen down for future use. The cells will metastasize to the tissue from which they were isolated to a greater extent than the original GFP-expressing tumor cells. This ability can be shown by the following assay. Hereinafter, these will be referred to as enhanced metastatic tumor cells (EMTC). Athymic mice are implanted iv with approximately 1×10 6 to about 5×10 6 EMTC into the tail vein. At approximately 25 to 30 days post implantation, moribundity or mortality is assessed, and the mice are euthanized. The tissue to which the cells are expected to metastasize is isolated and homogenized in PBS. A sample, e.g. 0.1 ml, of the homogenized tissue is transferred to a 96 well plate and fluorescence is measured via laser-scanning fluoroscopy, for example using an Acumen Explorer. The cell lines prepared and evaluated by the above procedures are valuable for the evaluation of candidate therapies, in particular clinical drug candidates and protocols, for the treatment of cancer and/or inhibition of metastasis. For evaluation of candidate therapies against tumors, GFP-expressing tumor cells in PBS are injected intra-peritoneally (ip) into athymic mice. Preferably about 10 million cells in a volume of about 500 μl PBS are injected. The mice are divided into control and treatment groups, and the treatment groups are treated with the candidate drug or protocol. It should be understood that the GFP-expressing tumor cells can be injected into the mice first, followed by treatment with the candidate drug or protocol, or the candidate drug or protocol can be administered followed by injection of the mice with GFP-expressing tumor cells. The ascites is harvested by euthanizing the mice and aspirating the ascites fluid from the peritoneum. The peritoneal cavity is rinsed with saline, which is then recovered. The ascites and the recovered saline are transferred to a tube, filtered through a 40 μm nylon filter to obtain a single cell suspension, and centrifuged at about 1500 rpm for a period of about 10 minutes. The supernatant is removed, and the cell pellet resuspended in fresh saline. A sample, e.g. 0.1 ml, from each mouse is transferred into a 96 well plate to evaluate cell number (reported as relative fluorescence units) utilizing laser-scanning fluoroscopy, for example, an Acumen Explorer. If the treated mice show a lower relative fluorescence than the control group, the candidate therapy is useful for the treatment of that type tumor. For evaluation of candidate therapies for inhibiting metastasis, enhanced metastatic tumor cells maintained in RPMI 1640 medium plus 10% FBS and 1% Geneticin (G418) are injected intravenously into athymic mice via the tail vein. Preferably about 2 million cells in a volume of about 200 μl serum free RPMI1640 are employed. The mice are randomized into control and treatment groups, and the treatment groups are treated with the candidate drug or protocol. It should be understood that the EMTCs can be injected into the mice first, followed by treatment with the candidate drug or protocol, or the candidate drug or protocol can be administered followed by injection of the mice with EMTCs. When the control mice are moribund or when they die, their metastatic tumor burden evaluated. In addition to survival, a quantitative evaluation of anti-metastatic efficacy can be made using the present invention by measuring the fluorescence intensity of tissue homogenates. Live mice are euthanized, and tissue to be evaluated is removed and homogenized in saline. A sample of the tissue homogenate, e.g. 0.2 ml, from each mouse is transferred to a 96 well plate, and fluorescence is then read using laser-scanning fluoroscopy, e.g. an Acumen Explorer. Using this method, the amount of metastasis as compared to the control group can be determined. If the treated my show a lower metastatic tumor burden, the candidate drug inhibits metastasis. EXAMPLES Example 1 Preparation of Bicistronic GFP Construct The bicistronic GFP construct was prepared and provided by Anne Chua and Ueli Gubler, and contained genes for both Renilla mulleri GFP (Prolume Ltd., Pinetop, Ariz.) and the Neomycin phosphotransferase (Neomycin resistant marker) for G418 selection. The sequence of the R. mulleri GFP was engineered into a mammalian expression vector as follows. The vector “pCMV-tag 5A” (Stratagene, Genbank accession number AF076312) was first modified by removing the sequence fragment between the single NotI and BstBI sites. This leaves a plasmid backbone consisting of the ColEl origin of replication, the HSV-TK polyA sequence and the CMV promoter. The deleted fragment was then replaced with a fragment encoding an [IRES-Neomycin phosphotransferase resistance marker]. The IRES-sequence was disabled based on the principle described by e.g. Rees et al, Biotechniques 20:102, 1996, incorporated by reference herein. The disabling fragment was chosen to represent the bacterial beta-lactamase (“bla”) promoter; this strategy allowed for the use of the neomycin-phosphotransferase marker for plasmid selection in E. coli (Kanamycin). In a third step, the ORF for the R. mulleri GFP was inserted upstream of the IRES sequence, in between two SfiI sites. The HSV-TK sequence that is located downstream of the NEO-resistance gene serves as a polyA signal sequence for expression in mammalian cells. A simple schematic of the crucial portions of this plasmid is shown in FIG. 15 . Example 2 Preparation of Bicistronic GFP Construct The sequence of R. mulleri GFP was engineered for stable expression in mammalian cells using a specifically designed modular vector. The construct was prepared and provided by Ann Chua and Ueli Gubler, and contained genes for both Renilla mulleri GFP (Prolume Ltd., Pinetop, Ariz.) and the Neomycin phosphotransferase (Neomycin resistant marker) for G418 selection. The sequence of the R. mulleri GFP was engineered into a mammalian expression vector as follows. Step 1 The vector “pCMV-tag 5A” (Stratagene, Genbank accession number AF076312) was first modified by removing the sequence fragment between the single NotI and BstBI sites. This leaves a plasmid backbone consisting of the ColEl origin of replication, the HSV-TK polyA sequence and the CMV promoter. Step 2 By overlap-PCR, a module of having the general makeup 5′-AscI-IRES-Neomycin phosphotransferase-BstB1-3′ was generated. Within this module, the IRES-sequence was disabled based on the principle described by e.g. Rees et al, Biotechniques 20:102, 1996, incorporated by reference herein. The disabling fragment was chosen to represent the bacterial beta-lactamase (“bla”) promoter (Seq ID No. 1); this strategy allowed for the use of the neomycin-phosphotransferase marker for plasmid selection in E. coli (Kanamycin) as well as selection of mammalian cells in G418. It also eliminated the need for an extra transcription unit for plasmid selection in E. coli , making the final plasmid smaller. Step 3 The plasmid-derived NotI/BstbI module from step 1 and the AscI-IRES-Neo-BstbI module from step 2 were subsequently ligated and circularized by addition of a synthetic short AscI to NotI-linker. DNA was transformed and single isolates were checked for proper assembly of the three fragments. A properly assembled plasmid clone was selected for the last modification. Step 4 The cloning sites for the gene of interest (GFP) were subsequently introduced into the plasmid via a short synthetic linker of the structure EcoRV-SfiIa-stuffer-SfiIb-NotI. This linker was cloned into the plasmid derived in step 3 via ligation in between the OliI-NotI sites, thus placing it upstream of the IRES-NEO module. OliI and EcoRV are both blunt-end cutters, making them compatible for ligation without recreating the sites. The rationale behind using SfiI sites for cloning the gene of interest was twofold: SfiI is an 8-base cutter and thus occurs very infrequently as internal sites in ORFs chosen for expression in this vector. The site has the recognition sequence ggccnnnnnggcc (Seq ID No. 2), allowing the design of two different sites at either end of an ORF for directional cloning. The sequence 5′-ggccattatggcc-3′ (Seq ID No. 3) was chosen as the SfiI-a (upstream) site, while the SfiI-b (downstream) site has the sequence 5′-ggccgcctcggcc-3′ (Seq ID No. 4). Step 5 The ORF for the R. mulleri GFP engineered to have the appropriate SfiI sites was inserted upstream of the IRES sequence, in between two SfiI sites, resulting in a plasmid of 4196 bp length (Seq ID No. 5). The restriction map for the GFP Expression Vector is provided in FIG. 16 . Example 3 Establishment of LOX-GFP Cells Cell Transfection Cells from the human melanoma cell line LOX (National Cancer Institute) were cultured in RPMI1640 medium RPMI1640 medium with 10% fetal bovine serum (FBS). All culture medium and related reagents were purchased from Gibco (Invitrogen Corporation, Carlsbad, Calif.). Cells were transfected using Fugene (Roche Molecular Diagnostics) transfecting reagent at a ratio of 3:1 (Fugene:DNA). The bicistronic GFP construct was kindly prepared and provided by Ann Chua and Ueli Gubler in accordance with Example 1. The construct contained genes for both Renilla mullerei (Prolume Ltd., Pinetop, Ariz.) and Neo (Neomycin resistant gene) for G418 selection. 100 μl of RPMI1640 serum free medium was added to a small sterile tube, and then 9 μl pre-warmed Fugene was added. Finally, 3 μl GFP DNA construct was added to the bottom of the tube, mixed, and incubated at room temperature for 30 min. The entire Fugene/DNA mixture was added to one T-25 flask of 80% confluent LOX cells, and the cells were incubated for 6 hrs. Following incubation, the medium in the flask was removed and replaced with selection medium containing 1% Geneticin (G418). Selection for G418 resistance took about four weeks, after which approximately 30% of cells expressed GFP at various levels. To further select for the most highly GFP expressing cells, the cells were sorted at the Department of Pathology and Pediatrics, UMDNJ. Cells were sorted to collect the top 5% GFP expressing cell population. Cells isolated and grown up from the first sort were subsequently sorted a few weeks later, so that the resulting cells achieved 100% GFP expression. These LOX-GFP cells were then frozen down for future in vivo use. Example 4 Establishment of LOX-GFP-LM Cells Five female Nu/Nu mice (Charles River) were implanted intra-peritoneally (ip) with 10 million LOX-GFP cells each. After 13 days, ascites fluid containing LOX-GFP cells was harvested from the mice, and the ascites was diluted 1:4 with PBS. The ascites/PBS solution was then filtered through a 40 μm nylon cell strainer and centrifuged at 1500 rpm. Pelleted cells were resuspended in PBS and counted to achieve the desired cell concentration. Twenty female Nu/Nu mice (10 mice/group) were implanted intravenously (iv) via the tail vein with the LOX-GFP tumor cells isolated from ascites (above) at either 2×10 6 cell/mouse or 1×10 6 cell/mouse. After a few mice in the group were found moribund or dead, the remaining mice in the group were euthanized. Lungs were isolated and examined under a fluorescence stereomicroscope to see potential micro-metastases. The resultant iv LOX-GFP lung metastases are listed in Table 1. TABLE 1 LOX-GFP ascites implantation into Nu/Nu mice. Days post- implantation 2 × 10 6 cell/mouse 1 × 10 6 cell/mouse Day 36 5 mice dead 2 mice with lung metastases with moderate GFP expression. 3 mice had no signs of metastasis Day 59 2 mice dead 2 mice with lung metastases with no GFP expression. 1 mouse (No. 10) had lung metastases with strong GFP expression 5 mice had no signs of metastasis It appeared that the rate of metastasis to lung was not as high as reported in the literature, which might cause difficulty for quantitative analysis. Some metastatic colonies lost GFP expression, suggesting the cell line was not stable in vivo. One mouse (No. 10) from the 1×10 6 cell group had very strong GFP expression in the lung metastatic colonies. Four colonies of LOX-GFP cells (about 2×3 mm) were recovered from the lung of mouse No. 10 (see above), by gentle dissection. Each of the colonies was ground separately on sterile metal gauze (#40), washed with 2-3 ml culture medium and centrifuged at 1500 rpm. Cell pellets were washed in RPMI1640 culture medium containing 10% penicillin/streptomycin and 10% FBS and were seeded into T-25 flasks containing 10 ml of RPMI1640 medium containing 10% FBS and 2% penicillin/streptomycin. The cells were routinely passaged in selection medium containing G418 to remove any mouse cell contaminants. After 2-3 passages, cultures from colony numbers 1 and 2 were discarded due to weak GFP expression and poor growth. Cultures from colony numbers 3 and 4 were scaled up and frozen down for future use. Cells from colony number 4 were deemed superior in terms of GFP expression and growth and were named LOX-GFP-LM (LM for Lung Metastasis). Example 5 Metastasis of LOX-GFP-LM Cells In Vivo Thirty female SCID beige mice (Charles River) were implanted iv with one, two, or five million LOX-GFP-LM cells into the tail vein. At day 29 post implantation, moribundity or mortality from each group up to that point was recorded, and the remaining mice were euthanized. Lungs were isolated and homogenized in 3 ml of PBS per sample. 0.1 ml per sample of lung homogenate was transferred into a 96 well plate and fluorescence was measured using an Acumen Explorer. After 29 days post-implantation, the incidence of morbidity or mortality was directly related to the cell number implanted, with the highest morbidity and mortality rate observed in mice implanted with 5 million cells (Table 2.) All mice had GFP expressing lung metastatic colonies, however the number and density of the lung metastases varied greatly. TABLE 2 LOX-GFP-LM induced experimental lung metastases in SCID beige mice. Relative Fluorescence Morbidity/ Lung GFP Expression Units of Lung Mortality Metastases Observed in Lung Homogenates Group Day 29 Present Metastases (mean ± SD) 5 × 10 6 cells/ 7/10 3/3 3/3 Not assessed mouse 2 × 10 6 cells/ 4/10 6/6 6/6 58457423 ± mouse 52009858 1 × 10 6 cells/ 2/10 8/8 8/8 45712175 ± mouse 30253653 Example 6 Characterization of LOX-GFP-LM, LOX-GFP, and LOX Cells Morphology of LOX, LOX-GFP, and LOX-GFP-LM Tumors In Vivo: Nine female SCID beige mice (Charles River) were implanted subcutaneously (sc) with either LOX or LOX-GFP cells, or were implanted iv with LOX-GFP-LM cells. LOX and LOX-GFP tumors were allowed to grow until they reached a volume of ˜300-400 mm 3 (about 10-14 days post implantation) and were then collected and fixed in 10% formalin. LOX-GFP-LM cells were allowed to develop lung metastases over 29 days, and then portions of the lung were harvested and fixed in 10% Formalin. Both tumor and lung samples were stained with H & E and morphology was assessed. No difference in morphology between the tumors derived from the three different LOX tumor cell lines (LOX, LOX-GFP and LOX-GFP-LM) was observed ( FIG. 1 ). Example 7 Gene Microarray Analysis of LOX, LOX-GFP, and LOX-GFP-LM Cell Lines Cells were plated in 6 well culture plates with RPMI-1640, 10% FBS, and 1% Penicillin/Streptomycin (plus 0.5% G418 for LOX-GFP and LOX-GFP-LM cells), and incubated for 48 hours. After removing medium, the cells were washed once with PBS, 0.8 ml of RLT buffer was added per well, and the plate was shaken for 2 min at room temperature. Cell suspensions from each well were transferred into separate tubes and were frozen at −80° C. for future microarray analysis. Four separate samples from each tumor line were run in the microarray assay using Affymetrix U133plus2 chips. Unique gene signatures were shown for both LOX-GFP and LOX-GFP-LM cells as compared to the LOX parental cell line. ( FIG. 2 ) In LOX-GFP-LM cells, 124 genes were found to be altered overall, with 67 genes up-regulated and the remaining 57 genes down-regulated, as compared to LOX-GFP cells. Among the genes with at least 4 fold up-regulation, a series of genes (at least 7 genes, marked in bold) were recognized to be related adhesion, matrix degradation, or angiogenesis. Another category of genes (marked in underline) were recognized as related to growth factors or differentiation. Both series of genes comprise the type of genes that might be expected to be enriched in a cell population with a more aggressive and invasive phenotype. Example 8 LOX-GFP Peritoneal (Ascites) Model Human melanoma LOX-GFP cells, prepared in accordance with the procedure of Example 3, were maintained in RPMI 1640 medium plus 10% FBS, and 1% Geneticin (G418). Female Nu/Nu mice were injected intra-peritoneally (ip) with 10 million LOX-GFP cells in a volume of 500 μl PBS, randomized into groups, and treated as shown in Tables 3, 4, and 5 with a variety of doses and/or dose schedules. Compounds Tested [4-Amino-2-(1-methanesulfonyl-piperidin-4-ylamino)-pyrimidin-5-yl]-(2,3-difluoro-6-methoxy-phenyl)-methanone (Compound A) 4-[4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound B) 5-(4-Ethoxy-quinolin-6-ylmeth-(Z)-ylidine)-2-(2-hydroxy-1-(R)-phenyl-ethylamino)-thiazol-4-one (Compound C) 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D) TABLE 3 Treatment groups for LOX-GFP Ascites model. iv cell Day of injection Number Days dosed (after ascites Group Day 0 Treatment of mice cell injection) harvest 1 10 × 10 6 Vehicle for Taxol 2 Days 4, 5, & 6 Day 7 2 cells/mouse Taxol 10 mg/kg iv, 0.2 ml, 2 Days 4, 5, & 6 Day 7 3 doses 3 Taxol 10 mg/kg iv, 0.2 ml, 2 Days 5 & 6 Day 7 2 doses 4 Taxol 10 mg/kg iv, 0.2 ml, 2 Day 6 Day 7 single dose 5 Vehicle for Compound A 2 Days 4, 5, & 6 Day 7 6 Compound A 40 mg/kg 2 Days 4, 5, & 6 Day 7 po, 0.2 ml, 3 doses 7 Compound A 40 mg/kg 2 Days 5 & 6 Day 7 po, 0.2 ml, 2 doses 8 Compound A 40 mg/kg 2 6 Day 6 Day 7 po, 0.2 ml, single dose TABLE 4 Treatment groups for LOX-GFP Ascites model. Tumor cell Day of implanted Number Days dosed (after ascites Group (day 0) Treatment of mice cell injection) harvest 1 10 × 10 6 Vehicle for Compound B 5 Days 2, 3, 4.5, 6 & 7 Day 8 2 cells/mouse Compound B 40 mg/kg 5 Days 2, 3, 4.5, 6 & 7 Day 8 sc, 0.2 ml, 6 doses 3 Vehicle for Compound B 5 Days 2, 3, 4.5, 6 & 7 Day 8 4 Compound C 200 mg/kg 5 Days 2, 3, 4.5, 6 & 7 Day 8 po bid, 0.2 ml, 12 doses 5 Vehicle for Taxol 5 Days 5, 6 & 7 Day 8 6 Taxol 15 mg/kg iv, 0.2 ml, 5 Days 5, 6 & 7 Day 8 3 doses TABLE 5 Treatment groups for LOX-GFP Ascites model. Tumor cell Day of implanted Number Days dosed (after ascites Group (day 0) Treatment of mice cell injection) harvest 10 × 10 6 Vehicle for Compound D 4 Days 4, 5 & 6 Day 7 1 cells/mouse Compound D 100 mg/kg 4 Days 4, 5 & 6 Day 7 po bid, 0.2 ml, 6 doses 2 Compound D 50 mg/kg 4 Days 4, 5 & 6 Day 7 po bid, 0.2 ml, 6 doses 3 Compound D 25 mg/kg 4 Days 4, 5 & 6 Day 7 po bid, 0.2 ml, 6 doses 4 Taxol 15 mg/kg iv, 0.2 ml, 4 Days 5 & 6 Day 7 2 doses 5 Taxol 15 mg/kg iv, 0.2 ml, 4 Days 5 & 6 Day 7 2 doses + Compound (Taxol) D 100 mg/kg po bid, 0.2 ml, Days 4, 5 & 6 6 doses (Compound D) 6 Taxol 15 mg/kg iv, 0.2 ml, 4 Days 5 & 6 Day 7 2 doses + Compound (Taxol) D 50 mg/kg po bid, 0.2 ml, Days 4, 5 & 6 6 doses (Compound D) 7 Taxol 15 mg/kg iv, 0.2 ml, 4 Days 5 & 6 Day 7 2 doses + Compound (Taxol) D 25 mg/kg po bid, 0.2 ml, Days 4, 5 & 6 6 doses (Compound D) Ascites Harvesting Procedure (at Day 7 or 8 Post Implantation): Mice were euthanized, and then a small incision was made along the midline of the abdomen through the skin and peritoneum. A glass Pasteur pipet was utilized to aspirate and remove ascites fluid from the peritoneum, and the ascites was transferred to a 15 ml tube. 3 ml saline was used to rinse the peritoneal cavity, and all of the saline was recovered and transferred into the 15 ml tube containing the ascites fluid. The ascites cell suspension was filtered through a 40 μm nylon filter to obtain a single cell suspension and centrifuged at 1500 rpm for 10 min. The supernatant was removed, and the cell pellet was resuspended in 2 ml of fresh saline. 0.1 ml from each sample was transferred into a 96 well plate to evaluate cell number (reported as relative fluorescence units) utilizing an Acumen Explorer. Results Seven or eight days was a sufficient duration for adequate ascites to form in mice implanted ip with LOX-GFP cells, and additionally was sufficient to measure the growth inhibitory properties of cancer therapeutics administered systemically. Both Taxol and Compound A demonstrated inhibitory effects on LOX-GFP ascites growth that was directly dependent on the number of treatments. A single dose did not inhibit cell growth, whereas two doses reduced cell growth, and three doses reduced cell growth maximally. ( FIGS. 3 and 6 ). Both Compound B and Compound C demonstrated inhibitory effects on LOX-GFP ascites growth. ( FIGS. 4 and 7 ). Compound D inhibited LOX-GFP ascites growth at several doses, however the effect was not dose-dependent. With regard to ascites growth inhibition, there was no added benefit to combining Compound D with Taxol as compared to Taxol alone, however the combination was not antagonistic. ( FIGS. 5 and 8 ). Example 9 LOX-GFP-LM Metastasis Model Human melanoma LOX-GFP-LM cells, prepared in accordance with the procedure of Example 4, were maintained in RPMI 1640 medium plus 10% FBS and 1% Geneticin (G418). Female SCID beige mice were injected iv via the tail vein with 2 million cells in a volume of 200 μl serum free RPMI1640, randomized into groups, and treated as shown in Tables 6 and 7 with a variety of doses and/or dose schedules. When >3 mice in the Vehicle treated group were found moribund, five mice per treatment group were removed to evaluate metastatic lung tumor burden. The remaining mice from each group were monitored for survival benefit until they were moribund. Compounds Tested 4-[(4S,5R)-4,5-Bis-(4-chloro-phenyl)-2-(2-isopropoxy-4-methoxy-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-2-one (Compound D) 3-methyl-5-(2-chlorophenyl)-7-amino-pyrazolo[3,4][1,4]benzodiazepine (Compound E) TABLE 6 Treatment groups for LOX-GFP-LM experimental metastasis model (Compound E Study) Tumor Day of lung cells Days of harvest injected Number of dosing after (5 Groups (day 0) Treatment mice cell injection mice/group) 1 2 × 10 6 Vehicle 20 Day −1 to 21 25 2 cells/ Compound E 15 Day −1 to 21 25 mouse 5 mg/kg po, (7+/4− bid schedule) 3 15 Day −1 to 7 25 4 15 Day 3 to 21 25 (4+/3− schedule) TABLE 7 Treatment groups for LOX-GFP-LM experimental metastasis model (Compound D Study) Day of Tumor Days of lung cell Number dosing harvest implanted of after cell (5 mice/ Groups (day 0) medication mice injection group) 1 2 × 10 6 Vehicle 20 Day −1 to 21 26 2 cells/mouse Compound D 15 Day −1 to 21 26 3 200 mg/kg po, 15 Day −1 to 7 26 4 bid 15 Day 3 to 21 26 Two parameters were assessed for quantitative evaluation of anti-metastatic efficacy: 1) Fluorescence intensity of lung homogenates and 2) Survival. Fluorescence Intensity of Lung Homogenates: 5 mice per treatment group were removed from the study at Day 25 or 26 for evaluation of lung metastatic tumor burden. Mice were euthanized, and lungs were removed, placed in 3 ml saline, and homogenized. 0.2 ml of lung homogenate was transferred to a 96 well plate, and fluorescence was read using Acumen Explorer. ( FIGS. 9 and 10 ). Fluorescence was reported in relative fluorescence units (RFU). (Tables 8 and 9, FIGS. 11 and 12 ). Statistical analysis was determined by Student-test or Mann-Whitney U test, and statistic differences between groups were considered to be significant when the probability value (p) was ≦0.05. TABLE 8 Relative Fluorescence Units (RFU) of lung homogenate samples run on Acumen Explorer (Compound E Study) P values Vs Vs Vs RFU *TGI % Vehicle Day −1-d23 Day −1-d7 Treatment (mean ± SD) CV At day 25 Group Group Group Vehicle 48793363 ± 2922819  47 Compound E 12738540 ± 5426672  43 73.9 0.022 5 mg/kg po, bid Day −1-23 Compound E 51670506 ± 29321586 57 −5.9 0.87 0.040 5 mg/kg po, bid Day −1-7 Compound E 8618508 ± 3198528 37 82.3 0.017 0.19 0.030 5 mg/kg po, bid Day 3-23 *TGI = Tumor growth inhibition relative to Vehicle control group. TABLE 9 Relative Fluorescence Units (RFU) of lung homogenate samples run on Acumen Explorer (Compound D Study) P value RFU *TGI % Vs Vs Treatment (mean ± SD) CV At day 26 Vs vehicle Day −1-d21 Day −1-d7 Vehicle 62091178 ± 16262491 26 Compound D 13230372 ± 11960417 90 78.7 0.001 200 mg/kg po, bid Day −1-21 Compound D 21092887 ± 10460489 50 66.0 0.002 0.301 200 mg/kg po, bid Day −1-7 Compound D 2359191 ± 526586  22 96.2 0.001 0.077 0.004 200 mg/kg po, bid Day 3-21 *TGI = Tumor growth inhibition relative to Vehicle control group. Survival Survival represented overall metastatic status either due to lung metastasis or metastasis to other organs. Moribundity due to labored breathing or hind limb paralysis was monitored and recorded as the surrogate endpoint for survival. For survival assessment, results were plotted as the percentage survival against days after tumor implant. The Increased lifetime-span (% ILS) was calculated as: ILS %=100×[(median survival day of treated group−median survival day of control group)/median survival day of control group]. Median survival or (50% survival time) was determined utilizing Kaplan Meier survival analysis. ( FIGS. 13 and 14 ). Differences in survival were analyzed by the log-rank test. Statistic differences between groups were considered to be significant when the probability value (p) was ≦0.05. Similar to the initial characterization of the LOX-GFP-LM metastasis model in Example 5, cells metastasized to lung in 100% of mice when injected iv, and the time frame for observing lung metastasis was also similar (40% survival @ 29 days in the previous study vs. 50% survival @ 24 or 28 days in the present two studies). (Tables 10 and 11; FIGS. 13 and 14 ) Compound E had equivalent anti-metastatic activity with either late intervention (Dosed Day 3 through 23) or full length intervention (Day −1 through 23) as assessed by fluorescence intensity of lung homogenates. Compound D had superior anti-metastatic activity with late intervention (Dosed Day 3 through 23) as compared to Vehicle, as assessed by fluorescence intensity of lung homogenates. TABLE 10 Survival of groups treated with Compound E as compared to Vehicle control group. P values 50% Vs survival Vehicle Vs Vs Treatment days ILS % Group Day −1-d23 Day −1-d7 Vehicle 24 Compound E 5 mg/kg po, bid 28 16.7 <0.0001 Day −1-d23 Compound E 5 mg/kg po, bid 25 4.2 0.0001 0.02 Day −1-d7 Compound E 5 mg/kg po, bid 28 16.7 <0.0001 0.83 0.03 Day 3-d23 TABLE 11 Survival of groups treated with Compound D as compared to Vehicle control group. P values 50% Vs survival Vehicle Vs Vs Treatment days ILS % Group Day −1-d23 Day −1-d7 Vehicle 28 Compound D 200 mg/kg po, bid 31 10.7 0.0074 Day −1-d21 Compound D 200 mg/kg po, bid 28 0 0.649 0.03 Day −1-d7 Compound D 200 mg/kg po, bid 36 29 <0.0001 0.15 0.002 Day 3-d21 Example 10 Comparison of LOX-GFP-LM and LOX-GFP on Experimental Lung Metasis Previously generated human melanoma LOX-GFP and LOX-GFP-LM cells were maintained in RPMI 1640 medium plus 10% FBS, and 1% Geneticin (G418). Female SCID beige mice (25 mice each tumor line) were injected iv via the tail vein with either the LOX-GFP or LOX-GFP-LM, 2 million cells in a volume of 200 μl serum free RPMI1640. Lungs were harvested from five mice for each time point (day 14, 21 and 28 after implantation, total 15 mice, see Table 12). The rest of the mice, 10 mice per group, were monitored for survival benefit until they were moribund. Two parameters were assessed for quantitative evaluation of tumor growth: 1) fluorescence intensity of lung homogenates and 2) survival. TABLE 12 Implantation of LOX-GFP and LOX-GFP-LM into SCID beige mice Tumor cell Day of lung implanted harvesting Groups (day 0) medication Mice No. (5 mice/group) 1 2 × 10 6 LOX-GFP-LM 25 14, 21 and 28 2 cell/0.2 ml/ LOX-GFP 25 14, 21 and 28 mouse, iv Total 50 Fluorescence Intensity of Lung Homogenates: Five (5) mice were removed from each group for evaluation of lung metastatic tumor burden. The mice were euthanized, and their lungs were removed, placed in 3 ml saline, and homogenized. Lung homogenate, 0.2 ml, was transferred to a 96 well plate, and fluorescence was read using Acumen Explorer. ( FIG. 17 ). The fluorescence was reported in relative fluorescence units (RFU). ( FIG. 18 and Table 13). Statistical analysis was determined by Student-test or Mann-Whitney U test and statistic differences between groups were considered to be significant when the probability value (p) was ≦0.05. TABLE 13 Summary table of tumor lines (LOX-GFP-LM and LOX-GFP induced experimental metastasis Lung metastasis: Relative Fluoresecence 50% Unit (RFU) (mean ± SD) Survival Tumor line Day 14 Day 21 Day 28 Days LOX-GFP- 1375463 ± 461906 38173338 ± NA 25 LM 26458094 LOX-GFP 1323534 ± 465272  1908836 ± 13848195 ± 31 376654 22888238 P value 0.86 0.037 <0.001 Survival Assessment For survival assessment, moribund mice due to difficulty of breathing or hind limb paralysis as end point were recorded, and results are plotted as percent survival against days after tumor implant. Median survival was determined utilizing Kaplan Meier survival analysis. Differences in survival curves were analyzed by the log-rank test and statistic differences between groups were considered to be significant when the probability value (p) was ≦0.05. ( FIG. 19 ) Results and Discussion: SCID beige mice injected with LOX-GFP-LM, as compared to the same strain (SCID beige) of mice injected with LOX-GFP, exhibited a much higher lung metastasis rate (100%) at day 21 and a shorter survival time (all mice were dead in 25 days) with stable GFP transfection in vivo (100%). In the LOX-GFP group, at day 21, two out of five mice were found to have lung metastasis without showing GFP signals, suggesting a lower metastasis rate and non-stable GFP transfection in vivo. 50% survival time in the LOX-GFP group was 6 days delay versus LOX-GFP-LM group (31 days vs 25 days). Both groups did not show any lung metastasis at day 14. However, in the LOX-GFP-LM group, from day 21 to day 25, the mice either showed strong lung metastasis or were moribund. For the LOX-GFP groups, mice were dead or moribund from day 26 to over day 39. It appeared that there is no plateau time period in terms of tumor burden in lungs; in other words, when the lungs developed extensive lung metastasis, mice will quickly become moribund or dead in a short time period. CONCLUSION LOX-GFP-LM causes more lung metastasis with stable GFP signal, as compared to LOX-GFP in the same strain of mice. Both tumor lines showed dynamic tumor burden growth in lungs over time.

The present invention relates to a LOX-GFP marker and methods of analyzing tumor burden in ascites or in lung. The invention also relates to a new LOX-GFP-LM cell line which demonstrates increased lung metastasis. The methods of the invention result in better quantitative tumor burden assessment and improved efficacy evaluation. These improved models provide a feasible alternative for ascites or experimental metastasis evaluation of novel cancer therapeutics.

TECHNICAL FIELD The present invention relates to a non-volatile memory capable of executing a program independently from a microprocessor. BACKGROUND OF THE INVENTION The families of the non-volatile memories, among which are the EEPROMs and the Flash EEPROM, share a fundamental property: They all effect a conversion of binary codes. Such conversion is performed by decoding the code that is introduced in input, getting a number of distinct signal lines, resulting from all the possible combinations of the bits of the input code; these lines are then encoded in the desired output word through a circuit called an encoder. The memory matrix produces therefore the desired functional relationship between input and output. From this point of view it is reasonable to classify a non-volatile matrix as a combinatorial circuit, not as a sequential circuit because the outputs depend entirely from the actual inputs and not from the preceding history of the circuit. What is stored is the functional relationship between inputs and outputs. In the electronic devices comprising microcomputers, that is computers in which a microprocessor is present, the non-volatile memory is used to store the program that must be performed by the microprocessor. The microprocessor is an integrated circuit that contains a control unit and an arithmetic-logic unit and has an internal state that is usually controllable from the outside through a programmable fixed memory. The microprocessor is a very complex unit, capable of performing programs involving operations of calculation, of comparison of data, of timing and other usually essential operations in the actual electronic devices. The structure of a microcomputer essentially consists of a central processing unit (microprocessor), a memory, and input/output devices. The program that must be performed by the microprocessor is stored in a non-volatile memory. During operation the microprocessor extracts the instructions from the memory, performing them in succession and elaborating therefore the data according to the program. During elaboration the results of the same can be provided to the outside through the output devices. The memory has therefore the purpose to preserve the program, i.e., the instructions and the data necessary to the operation of the microprocessor. In FIG. 1 there is schematically represented a block diagram of a microcomputer in which a non-volatile memory 1 is present that contains the control program of the system, a microprocessor 2 , a RAM memory 3 that temporarily stores instructions and data, these last written in memory locations each one having a respective address. Also present is an input/output I/O unit 4 that receives signals 5 of input and output. The various elements are connected by a data bus 6 , bidirectionally carrying the data among the different sections of the microcomputer, and by an address and control bus 7 , unidirectional and adapted to transmit the address of the memory location which is desired to be read or written, or of the input or output device that must be activated, and to carry the control signals necessary for example to enable the memory to operate in reading or writing or to enable the circuits of input-output interface. In FIG. 2 the functional structure of the non-volatile memory 1 of FIG. 1 is schematically shown. The input signals 8 , comprising control and address signals, are sent through input buffers 10 to a matrix of memory cells 11 that decodes them and sends respective coded signals 9 to output buffers 12 connected to the data bus 6 . The elements shown in FIG. 2 are present in any non-volatile memory and they constitute the fundamental structure thereof, even if other functional blocks are generally foreseen, such as for instance circuits of control or verification. In several applications, the power of calculation, essential for instance in a computer, is not necessary and the execution of a program is reduced to the simple execution in sequential way of the instructions contained in the memory. For instance, the distributors of drinks perform a sequential program, which uses in reality few instructions, performing only a series of timed operations that, in principle, do not require the use of a microprocessor. Other examples are found in appliances such as dishwashers, washing machines or refrigerators, which perform some identical cycles in time that need not a great flexibility. SUMMARY OF THE INVENTION The present invention provides a non-volatile memory configured to behave as a RISC (Reduced Instruction Set Computer) machine, performing a limited set of instructions that substantially make the non-volatile memory a sequential machine. This additional intelligence of the non-volatile memory does not pose it at the same level of a microcontroller; however, it could allow the memory itself to perform some simple tasks, leaving more difficult tasks to the microprocessor. Additionally, such memory would, if the particular application makes it possible, avoid the use of a microprocessor with a significant reduction of costs. The present invention provides a non-volatile memory semiconductor device having an address buffer block, a matrix of memory cells, and an output buffer block, the address buffer block receiving input signals external to the memory device, that in a first operating condition are controlled by devices external to the memory device, and transmitting signals to the matrix of memory cells, adapted to decode the received signals and to transmit in turn decoded signals in output through the output buffer block. Further included is a command block, activatable by an external control signal that, once activated, sets the memory device in a second operating condition in which the command block receives at least a part of the signals in output from the matrix of memory cells and, after having processed them, transmits internal address signals to the address buffer block to get a feedback inside the memory device suitable for making the memory device able to perform a succession of instructions memorized in the matrix of memory cells autonomously. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention will be evident from the following detailed description of one embodiment thereof, illustrated by way of a non-limiting example in the annexed drawings, wherein: FIG. 1 schematically shows a block diagram of a microcomputer; FIG. 2 schematically shows the functional structure of a non-volatile memory; FIG. 3 schematically shows an embodiment of a block diagram functional structure of a non-volatile memory according to the present invention; FIG. 4 shows a functional structure of the non-volatile memory of FIG. 3, expanded in some parts thereof; FIG. 5 shows in a chart the bits used for the execution of the code in an example of active mode of the memory; and FIG. 6 shows in a chart a sample set of instructions according to the bits of FIG. 5 . DETAILED DESCRIPTION OF THE INVENTION In FIG. 3 a functional structure of the non-volatile memory 1 of FIG. 1 is schematically shown, modified according to the present invention. Reference numeral 8 denotes a set of signal lines comprising address signals 8 ′ and generic control signals. The address signals 8 , through an input buffer 10 , are sent to the matrix 11 . With 11 a matrix of cells of memory is schematically indicated, as well as circuits for addressing the cells and for reading the same. The matrix 11 furnishes in output a set of signals 14 that carry a code depending on the current code on the address signals 8 ′. At least a portion 14 ′ of the output signals 14 from the matrix 11 are directed to a command unit 13 , that generally comprises a command interpreter, a program counter and an internal timer, so that the command unit processes them and therefore transmits a set of signals 15 to the address buffers 10 . In this way a feedback is obtained in the memory device that makes it autonomous and capable of performing a predefined set of instructions stored in the matrix 11 . The input signals 8 are also supplied, all or partly, directly to the command block 13 , for driving and controlling the same, and additionally external signals 16 can also be supplied directly feeding block 13 . To realize this type of functionality of the memory, it is for instance necessary that an external control pin is activated, the external control pin being included in the external signals 16 , so to switch the memory from the “passive” operating mode, in which the memory depends on the microprocessor, to an “active” operating mode in which the memory is autonomous. In FIG. 4 a functional block diagram similar to that of FIG. 3 is depicted, showing a Flash-type non-volatile memory, in which already existing elements are used to form the command block 13 of FIG. 3 . Particularly, between the matrix 11 and the outputs buffers 12 a latch circuit 17 is provided that temporarily stores the outputs of the matrix 11 and, during the active operating mode of the memory, transmits such outputs, through a feedback line 20 , to a command interpreter 18 (CUI), connected to all the units present in the memory; the command interpreter processes the aforesaid signals 20 , working as a microprocessor, and sends suitable commands 21 to the address buffers 10 , so to have an active feedback of the whole circuit, and to make the memory perform a prescribed determined instruction, the memory working as a sequential machine. The CUI 18 also receives input signals 8 and external control signals 16 , among which a control signal for activating the active operating mode and a clock signal, and it interacts with an internal counter 19 that can be used for keeping track of the performed operations and for calculating the correct memory address of the following instruction that must be executed, when the current one has been completed. The outputs 9 of the memory can drive, through multiplexers, possible actuators, without the necessity of passing the outputs 9 through a microprocessor. In FIG. 4 the possibility is also shown of providing a direct connection 22 among the address buffers 10 and the output buffers 12 , so that a microprocessor can use the Flash memory as an expanded I/O connection device, directly sending the inputs to the outputs and so exploiting the output buffers 12 of the memory as drivers of signal lines. Once the external driving pin is activated, the memory switches to the active operating mode and signals 14 at the output of the matrix 11 , that in this particular example constitute a set of 16 lines, are stored by the latch circuit 17 , so that they are transmitted to the CUI 18 and act as program instructions to be executed. In the case the CUI 18 processes codes of 32 bits, as supposed in this particular example, the latch circuit 17 stores the 16 bits at the output of the matrix 11 in two following cycles, so to provide to the CUI 18 a microinstruction with a suitable number of bits. Obviously the use of microinstructions formed by any number of bits can be envisaged, providing suitable latch circuits capable of storing such codes in more subsequent cycles before transmitting them to the CUI 18 for the processing. The CUI 18 processes such code and sends suitable internal address signals to the address buffers 10 and from these to the matrix 11 , that decodes them and puts on the output lines 14 a corresponding code. Such code can be transferred, through the outputs buffers 12 , to the output signals 9 , for instance to drive possible external actuators without passing through a microprocessor. In alternative, such code can be interpreted by the CUI 18 as a new microinstruction. In the chart of FIG. 5 there are shown the bits used by the CUI 18 for the execution of the code, in an example in which the memory is put in active operating mode to autonomously execute a program. The single bits have the following meaning: C 1 -C 4 : the first four bits are dedicated to identify the type of instruction; four bits mean sixteen possible executable instructions and these bits cannot take different meanings in the different instructions; O 0 -O 15 : they are sixteen bits of the microinstruction that contain the datum to load on the sixteen outputs 9 in particular types of instruction, each output assuming the same value of the corresponding bit; ck 0 -ck 11 : they represent the value, binary coded, selected for a timing; such value, multiplied for the period of the clock signal furnished by the outside, determines a wait time varying between 1 and 4096 times the period of external clock signal (for example, for a wait time equal to 4096 times such period, all the bits ck will be set to “1”); r 1 -r 4 : they are the coded expression of the sixteen outputs, when it is desired to address just one of it; in 0 -in 18 : they are the 19 bits of the microinstruction elaborated by the CUI 18 that, in some types of microinstruction, assume the meaning of code of comparison with the address signals 8 ′ coming from the outside of the memory; S: it is a bit that allows to decide if the selected configuration is active at “1” or at “0”; A 0 -A 18 : they are the 19 bits of the microinstruction that, in some types of microinstruction, assume the meaning of a new address to furnish to the memory matrix 11 to fetch the next microinstruction. In the chart of FIG. 6 there is shown a possible set of instructions according to the bits of the chart of FIG. 5 (X denotes a non influential bit), and each one of the sixteen instructions has the following meaning: 1. It is the instruction NOP, it doesn't perform anything; 2. the sixteen outputs 9 are loaded with the assigned value, specified in the microinstruction, i.e., O 0 -O 15 ; 3. the only output correspondent to the binary value of r 1 -r 4 of the sixteen outputs 9 is loaded; 4. the only output correspondent to the expression of r 1 -r 4 is loaded, but only when, externally to the memory the external address signal 8 ′ corresponding to the bit that, among the bits in 0 -in 18 of the microinstruction, is set to “1”, is set to “1”; for instance if in 7 =“1”, the loading of the output 9 correspondent to the binary value of r 1 -r 4 takes only place when the eighth bit of the external address signal 8 ′ is set to “1”; if more than one among the bits in 0 -in 18 of the microinstruction result to “1”, the loading of the encoded output in r 1 -r 4 occurs only when the logical OR operator of the correspondent external address signals 8 ′ is satisfied; 5. this is an instruction identical to the preceding one except for the fact that the operator logical AND of the external address signals 8 ′ must be satisfied, when more bits in 0 -in 18 of the microinstruction are set to “1”; 6. the only output given by r 1 -r 4 is loaded when externally to the memory an address signal is set to “1” that corresponds to that, among the bits in 0 -in 11 of the microinstruction, that is set to “1”, or at the expiration of a timing set through the value specified in the bits ck 0 -ck 11 of the microinstruction (if more than one among the bits in 0 -in 11 are to “1” the OR of the correspondents address signals 8 ′ must be satisfied); 7. it is an instruction identical to the preceding one except for the fact that the logical AND operator of the address signals 8 ′ must be satisfied, when more bits in 0 -in 11 of the microinstruction are set to “1”; 8. it is an instruction of unconditional jump: the program is directed to the address given by the bits A 0 -A 18 of the microinstruction; 9. the program is directed to the address given by A 0 -A 18 at the arrival of a logical signal on an external pin, with S it is possible to choose if the logical signal on the external pin will be active in the low or high state; 10. the program is directed to the address given by A 0 -A 18 at the arrival of a logical signal on an external pin, with S it is possible to choose if the logical signal on the external pin will be active in the low or high state, or because a timing set through the bits ck 0 -ck 7 of the microinstruction has expired; 11. it is an instruction of wait: the program jumps to the following address at the expiring of a timing set through the bits ck 0 -ck 11 ; 12. as the preceding one, this one is an instruction of wait: the program jumps to the following address at the expiring of a timing set through the bits ck 0 -ck 11 or because the address signal 8 ′ indicated by the bits in 0 -in 11 , or the AND of the indicated address signals, has arrived; 13. a data string is sent, specified in the bits O 0 -O 15 of the microinstruction, synchronously with the clock signal, on an external pin (useful, for instance, for the connection to a display); this operation is performed independently from the following ones and, to every hit of clock, a single bit O 0 , O 1 . . . O 15 is transmitted; 14. the address specified by the bits A 0 -A 18 is loaded into a possible RAM register or in a battery of latches to be added to the memory; 15. the address defined by the bits A 0 -A 18 is fetched from the RAM register, such address becoming the following one to be executed; and 16. it is the END instruction, that stops the program and the Flash memory returns in the passive operating mode or points to a preset address that contains a program of wait. Other codes that can result are, for example, a command that can make the Flash memory become an I/O expander so that the microprocessor uses the Flash only as a set of output buffers; another interesting command could allow the microprocessor to load the RAM register with the instructions 14 and 15 , interrupting the program of the Flash memory and subsequently making it restart from the selected address. Clearly the aforesaid instructions are only an example of implementation and they do not exhaust all the possibilities necessary to make the memory work as a sequential machine, but this set of instructions could already relieve the microprocessor from performing a quantity of tasks that in some applications can be very substantial.

A non-volatile semiconductor memory device that includes an address buffer block, a matrix of memory cells, and an output buffer block. The address buffer block receives input signals external to the memory device, that in a first operating mode are controlled by devices outside to the memory device, and transmit signals to the matrix of memory cells, which are adapted to decode the received signals and to transmit in turn output decoded signals through the output buffer block. A command block is provided that is activatable through an external control signal and once activated, it puts the memory device in a second operating mode in which the command block receives at least a part of the signals in output of said matrix of memory cells and, after having processed them, transmits internal address signals to the address buffer block. This provides a feedback inside the memory device capable of making the same able to autonomously execute a succession of instructions stored in the matrix of memory cells.

GOVERNMENT RIGHTS CLAUSE This invention was made with government support under Contract HL38118 awarded by the National Institutes of Health. The government has certain rights in the invention. RELATIONSHIP TO OTHER APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 07/689,652, filed on Apr. 23, 1991 now U.S. Pat. No. 5,368,608 issued on Nov. 29, 1994, as a continuation-in-part of Ser. No. 07/515,484 filed on Apr. 30, 1990, now abandoned, which in turn was a continuation-in-part of Ser. No. 07/176,789 filed on Apr. 1, 1988, now U.S. Pat. No. 5,094,661, issued on Mar. 10, 1992, all applications being assigned to the assignee hereof. The disclosure of the foregoing applications are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION This invention relates generally to materials which are resistant to in vivo calcification, and more particularly, to a method of preparing calcification-resistant biomaterials, such as bioprosthetic tissue, suitable for implantation in a living being. More than 100,000 cardiac valve prostheses are placed in patients each year. Frequently, valve replacement surgery is the only means of treating cardiac valve disease. Currently used replacement valves include mechanical valves which may be composed entirely of a synthetic polymeric material such as polyurethane; bioprosthetic valves derived from bovine pericardium or porcine aortic valves; and aortic homografts. Use of mechanical valves is frequently complicated by thrombosis and tissue overgrowth leading to valvular failure. Bioprosthetic heart valves have improved thrombogenicity and hemodynamic properties as compared to mechanical valve prostheses. However, calcification is the most frequent cause of the clinical failure of bioprosthetic heart valves fabricated from porcine aortic valves or bovine pericardium. Human aortic homograft implants have also been observed to undergo pathologic calcification involving both the valvular tissue as well as the adjacent aortic wall albeit at a slower rate than the bioprosthetic heart valves. Pathologic calcification leading to valvular failure, in such forms as stenosis and/or regurgitation, necessitates re-implantation. Therefore, the use of bioprosthetic heart valves and homografts has been limited because such tissue is subject to calcification. In fact, pediatric patients have been found to have an accelerated rate of calcification so that the use of bioprosthetic heart valves is contraindicated for this group. Unfortunately, pathologic calcification also further complicates the use of synthetic vascular grafts and other artificial heart devices, such as ventricular assist systems, because it affects the flexibility of the synthetic polymers used to produce the devices. The mechanism for pathological calcification of cardiovascular tissue is not fully understood. Generally, the term "pathologic calcification" refers to the undesirable deposition of calcium phosphate mineral salts. Calcification may be due to host factors, implant factors, and extraneous factors, such as mechanical stress. There is some evidence to suggest that deposits of calcium are related to devitalized cells, and in particular, cell membranes, where the calcium pump (Ca +2 --Mg +2 --ATPase) responsible for maintaining low intracellular calcium levels is no longer functioning or is malfunctioning. Calcification has been observed to begin with an accumulation of calcium and phosphorous, present as hydroxyapatite, which develops into nodules which can eventually lead to valvular failure. The preparation of bioprosthetic tissue prior to implantation typically includes treatment to stabilize it against subsequent in vivo enzymatic degradation, typically by crosslinking molecules, particularly collagen, on and in the tissue. Various aldehydes have been used for this purpose, including glyoxal, formaldehyde, and glutaraldehyde. Glutaraldehyde, however, is the agent of choice. In addition to fixing the tissue, glutaraldehyde is a good sterilizing agent and it reduces the antigenicity of the tissue. To date, glutaraldehyde is the only effective crosslinking agent for preparing tissues for implantation that can be used at physiologic pH under aqueous conditions. Unfortunately, glutaraldehyde is now known to promote calcification. There is, thus, a need in the art for a means of reversing the calcification-promoting effects of crosslinking agents such as glutaraldehyde. It would be particularly desirable to incorporate anti-calcification agents into existing protocols for preparation of clinical-grade biomaterials. Non-aldehyde crosslinking agents have been investigated, such as polyepoxides (e.g., polyglycerol polyglycidyl ethers sold under the trademark Denacol by Nagasi Chemicals, Osaka, Japan), but there have been no conclusive studies demonstrating efficacy of polyepoxide cross-linked tissues in vivo. Research on the inhibition of calcification of bioprosthetic tissue has primarily focussed on tissue pretreatment with either detergents or diphosphonate anticalcification agents. Detergent pretreatment with noncovalently linked detergents, such as sodium dodecyl sulfate (SDS), and a covalently bound detergent, such as amino oleic acid, have been demonstrated to be efficacious to materials exposed in circulating blood. However, both detergents and diphosphonates tend to wash out of the implanted bioprosthetic tissue with time due to blood-material interactions. Thus, these treatments merely delay the onset of the inevitable calcification process. Accordingly, there is also a need for a means of providing long-term calcification resistance for bioprosthetic heart valves and other implantable biomaterials or devices which are subject to in vivo pathologic calcification. In addition, detergents disadvantageously affect the tissue, resulting in a diminution of the collagen denaturation temperature, or shrink temperature (T s ), which is an important measure of material strength, durability, and integrity. In some cases, use of detergents results in local toxicity. There is, thus, a need for an effective method of imparting anticalcification properties to bioprosthetic tissues which is not accompanied by the deleterious effects of detergents. Further, all of the foregoing techniques still result in some degree of pathologic calcification in vivo as measured by calcium content of explanted specimens. There is, therefore, a need for a treatment that results in a greater level of calcification inhibition. The use of alcohols in biomaterial treatment protocols is well-known, but is typically limited to its use as a solvent and/or sterilizing agent. For example, alcohol has been used in sterilizing rinses and for storage solutions. However, there has never been any teaching or suggestion that ethanol has any effect on prevention of pathologic calcification. It would be advantageous to use this well-known compound in existing protocols for rendering bioprosthetic tissue calcification-resistant. It is, therefore, an object of this invention to provide a method of treating biomaterials, particularly glutaraldehyde-pretreated bioprosthetic tissue, to render the biomaterials resistant to in vivo pathologic calcification. It is another object of this invention to provide a method of treating biomaterials to have a long-term, or prolonged, resistance to in vivo pathologic calcification. It is also an object of this invention to provide a method of treating biomaterials to render the biomaterials resistant to in vivo pathologic calcification which can be easily incorporated into existing protocols for treatment of such materials, e.g., will permit the continued usage of the crosslinking agent glutaraldehyde. It is a further object of this invention to provide a method of treating biomaterials to render the biomaterials resistant to in vivo pathologic calcification which has little, if any, deleterious effect on physical or mechanical properties of the tissue, such as shrink temperature (T s ). It is a still further object of this invention to provide biomaterials suitable for implantation in a mammal which have improved resistance to in vivo pathologic calcification. SUMMARY OF THE INVENTION The foregoing and other objects are achieved by this invention which provides a method of treating a biomaterial, preferably glutaraldehyde-pretreated bioprosthetic tissue, such as porcine aortic valve components or bovine pericardium, with an alcohol to render the biomaterial resistant to calcification. The alcohol is preferably a lower aliphatic alcohol (C1 to C3), such as methanol, ethanol, propanol or isopropanol. In a preferred embodiment, the alcohol is ethanol. The term "biomaterial" as used herein refers to collagenous material which may be derived from different animal, typically mammalian, species. The biomaterial is typically suitable for implantation, such as bioprosthetic tissue or the like, but the invention should not be limited thereby. Specific examples include, but are not limited to, heart valves, particularly porcine heart valves; aortic roots, walls, and/or leaflets; bovine pericardium; connective tissue derived materials such as dura mater; homograft tissues, such as aortic homografts and saphenous bypass grafts; tendons, ligaments, skin patches, arteries, veins; and the like. Of course, any other biologically-derived materials which are known, or become known, as being suitable for in-dwelling uses in the body of a living being are within the contemplation of the invention. In accordance with a preferred embodiment of the invention, the biomaterial is pretreated with glutaraldehyde. Therefore, the alcohol treatment of the present invention can be incorporated into existing protocols and standard known methodologies for preparing bioprosthetic tissue for implantation. Of course, pretreatment of the biomaterial with other crosslinking agents is within the contemplation of the invention. In those embodiments wherein the biomaterial is crosslinked with glutaraldehyde, any of the variety of techniques for glutaraldehyde pretreatment may be used. In a typical glutaraldehyde pretreatment protocol, the biomaterial is exposed and/or stored in a solution of buffered glutaraldehyde under conditions suitable for crosslinking molecules on and in the biomaterial. For example, the biomaterial may be exposed to glutaraldehyde at appropriate temperatures (from about 4° C. to about 25° C.) and pH (from about 6 to about 8, preferably 7.1 to 7.4). Typical glutaraldehyde concentrations in the pretreatment solution range from about 0.2% to about 0.8% w/v or higher, and preferably 0.6%. In accordance with the method of the invention, the amount of alcohol in the treatment solution is greater than about 50% by volume, and preferably in the range of 60% to 80%. The biomaterial is contacted with, or exposed to, the alcohol for a period of time sufficient to render the bioprosthetic tissue resistant to in vivo pathologic calcification, illustratively, from about 20 minutes (i.e., the period of time required for diffusion of ethanol, for example, into bioprosthetic tissue) to in excess of 96 hours. For some biomaterials, excessive exposure to the alcohol may result in a decrease in the anticalcification effects of the alcohol, or may necessitate rehydration of the tissue. The length of time allotted for exposure in the embodiments described herein is illustrative and can be varied by those of skill in the art. For embodiments of the invention wherein the biomaterial is immersed, or soaked, in a liquid treatment solution of the alcohol, the exposure time is preferably between about 24 to 96 hours. However, longer exposure is within the contemplation of the invention provided appropriate storage conditions are maintained as will be described below. It should be noted, that no deleterious effects on the bioprosthetic tissue have been observed during the suggested period. The manner in which the biomaterial is exposed to the alcohol includes, but is not limited to vapor, plasma, liquid, and/or cryogenic application of the alcohol. Irrespective of the method of exposure, the time period should be sufficient to promote alcoholic-collagen interactions which inhibit calcification, but not so long as to cause irreparable dehydration of the tissue by the alcohol. In accordance with the method of the invention, the alcohol treatment solution is preferably liquid, and is water-based, i.e., is an aqueous solution of greater than about 50% alcohol, and preferably between 60% to 80% alcohol by volume, buffered to a pH between 6.0 and 8.0, and preferably between 7.0 and 7.6, and more preferably 7.4. Alternatively, a mixture of two or more organic solvents may be utilized in the practice of the invention provided that the combined volume of the organic solvents is greater than about 40%, preferably greater than about 50%. For example, a mixture of about 40% ethanol and about 40% acetone has proven effective (see, Example 7). Suitable buffers for use in the practice of the invention are those buffers which have a buffering capacity sufficient to maintain a physiologically acceptable pH and do not cause any deleterious effects to the biomaterial or interfere with the treatment process. Exemplary buffers include, but are not limited to phosphate-buffered saline (PBS), and organic buffers, such as N-N-2-hydroxyethylpiperzine-N'-2-ethanesulfonic acid (HEPES) or morpholine propanesulphonic acid (MOPS); and buffers which include borate, bicarbonate, carbonate, cacodylate. In preferred embodiments of the invention, the biomaterial is shaken, or agitated, during exposure to the alcohol treatment solution. Shaking can be accomplished in any manner, such as through use of an orbital shaker, or shaker stand. The alcohol treatment procedure is typically carried out at room temperature (25° C.). However, any temperature which is not deleterious to the tissue, for example 4° C. to about 37° C., is suitable for the practice of the invention. While the discussion herein is directed to the concentration of alcohol in the treatment solution, e.g., 50% or greater, it is to be understood that alcohols, such as ethanol, diffuse rapidly into tissue so that the concentration of alcohol in solution is approximately the same as the regional concentration of alcohol in the tissue. Therefore, the definition of the term "exposure" is to be construed broadly enough to encompass the in situ release of alcohol in implanted tissue, such as that resulting from hydrolysis of tetraethyl esters, for example. In preferred embodiments of the invention, the biomaterial, treated with alcohol as noted above to reduce calcification, should be rinsed prior to implantation or storage to remove excess alcohol and other deleterious components produced or used in the biomaterial treatment protocol, such as aldehyde fragments from the glutaraldehyde pretreatment. As used herein, the term "rinse" includes subjecting the biomaterial to a rinsing solution, including continuously or by batch processing, wherein the biomaterial is placed in a rinsing solution which may be periodically removed and replaced with fresh solution at predetermined intervals. During rinsing, the tissue is preferably shaken, or intermittently stirred, to ensure even distribution of the rinse solution. Rinsing may be accomplished by subjecting the biomaterial to a rinsing solution, such as fresh HEPES buffer at pH 7.4. Illustratively, a rinse may comprise soaking the biomaterial in fresh rinsing solution which is replaced three times over a period of about 5 to 15 minutes. Alternatively, the rinsing solution may be replaced at intervals of 6 to 8 hours, or less, over a rinse period of 24 hours. In a preferred embodiment, the HEPES buffer is replaced each hour over a rinse period of 24 hours. As used herein, the longer rinse periods are referred to as "washes." Exemplary rinsing solutions include physiologically suitable solutions, such as water, saline, PBS, HEPES buffered saline, ringers lactate (pH 7.4), sodium bicarbonate (pH 7.4), tris (pH 7.4), and imidazole (pH 7.4). Subsequent to rinsing, the treated bioprosthetic tissue is ready for implantation or may be sterilized and stored until use. Storage in standard glutaraldehyde solutions of the type typically used for long-term storage of clinical-grade bioprostheses may partially reverse the beneficial effects achieved by the alcohol treatment of the present invention (see, FIG. 2). In accordance with some embodiments of the invention, the treated biomaterial may be stored in an ethanolic-glutaraldehyde solution, preferably in an amount sufficient to maintain calcification inhibition and/or sterility. In a preferred embodiment, the treated biomaterial is stored in a buffered alcohol solution containing glutaraldehyde, typically greater than about 60%, and preferably between about 60% and about 80%, alcohol and less than about 0.5%, preferably between about 0.2% to 0.5%, glutaraldehyde. In a particularly preferred embodiment, the storage solution is 60% ethanol and 0.2% glutaraldehyde (see Table 6 below). In other embodiments of the invention, biomaterials which have been treated in accordance with the method of the invention are stored in an aldehyde-free environment. In preferred embodiments, treated bioprostheses are placed in sterile bags and subjected to sterilizing radiation, such as gamma-radiation. Of course, the ethanol treatment of the present invention is compatible with many other known sterilizing preservatives and/or techniques which are known, or can be developed, by those of skill in the art. In accordance with a further method embodiment of the invention, the alcohol treatment solution may also contains one or more additional anticalcification agents, including but not limited to, a soluble salt of a metallic cation, such as Al +3 or Fe +3 , preferably in a concentration range of 0.1M to 0.001M. Water soluble aluminum salts, for example, which are suitable additional anticalcification agents for use in the practice of the present invention, include without limitation, aluminum chlorate, aluminum lactate, aluminum potassium sulfate, aluminum sodium sulfate, aluminum sulfate, aluminum nitrate, and aluminum chloride. In a preferred embodiment, the soluble salt is AlCl 3 at 0.1M concentration. Also, water-soluble ferric salts, such as ferric chloride, ferric nitrate, ferric bromide, ferric sodium edentate, ferric sulfate, and ferric formate, are specifically included within the contemplation of the invention. Of course, any salt of aluminum, or iron, which is soluble in the solvent system of the treatment solution, may be used in the practice of the invention. Other embodiments of the invention include the biomaterials which have been produced by a method according to the invention. In preferred embodiments of the invention, these biomaterials exhibit improved anti-calcification properties, and/or long-term resistance to in vivo pathologic calcification. BRIEF DESCRIPTION OF THE DRAWINGS Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawings, in which: FIG. 1 is a graphical representation of the inhibition of porcine aortic valve calcification in a rat subdermal model for porcine aortic valve specimens (cusps) treated in accordance with a method of the invention; FIG. 2 is a graphical representation of the calcium content (μg/mg) of porcine aortic valve specimens, treated in accordance with a method of the invention, following 21 day subdermal implantation in rats; FIG. 3 is a graphical representation of the calcium content (μg/mg) of various porcine aortic valve specimens implanted in sheep for 150 days; FIG. 4 is a graphical representation of the 14 C cholesterol content, in μg/mg, of glutaraldehyde-pretreated porcine aortic valves as compared to glutaraldehyde-pretreated porcine aortic valves which have been treated with an aqueous solution of ethanol (40% and 80%) in accordance with a method of the invention, or with detergent (1% sodium dodecyl sulfate, SDS); FIG. 5 is a graphical representation of the calcification content of glutaraldehyde-pretreated porcine aortic valve specimens which have been subjected to a variety of solvents known to remove lipids from tissues; and FIG. 6 is a graphical representation of T s in °C. for porcine aortic valve specimens subjected to various ethanol treatment and storage regimens. DETAILED DESCRIPTION Given below are several specific illustrative techniques for producing calcification-resistant biomaterials in accordance with the principles of the invention. Although the examples given are primarily directed to the preparation of calcification-resistant heart valves, the techniques described herein are applicable to the creation of any other biomaterials, particularly a prosthesis or a bioprosthetic tissue suitable for implantation. Further, although the results have been presented in the form of rat subdermal implants and sheep bioprosthetic heart valve replacement studies, it should be noted that these animal model systems result in calcific deposits which closely resemble those seen in clinical-pathologic explant of human tissue. The correspondence of these animal models with human pathology has been documented in both light microscopic and electron microscopic studies. Glutaraldehyde-pretreated porcine aortic heart valves, both in stent and freestyle (stentless) form, were obtained from St. Jude Medical, Inc., St. Paul, Minn. and from Medtronic, Inc., Irvine, Calif. and used in the examples set forth below. Typically, the biomaterials are stabilized and preserved in glutaraldehyde following harvesting, illustratively in a 0.5% solution of glutaraldehyde in a buffer. EXPERIMENTAL SECTION Example 1 A dose response study was conducted and the results are shown graphically in FIG. 1. Glutaraldehyde-pretreated porcine aortic valve specimens were immersed for 24 hours in aqueous solutions of ethanol ranging in concentration from 0% (control) to 80% ethanol. The ethanol solutions were buffered at pH 7.4 with HEPES (0.05M). The treated porcine aortic valve specimens were implanted in two subcutaneous pouches dissected in the ventral abdominal wall of weanling rats (male, CD, Sprague-Dawley, weighing 50-60 gm). After a period of 21 days, the specimens were removed and examined for calcification by measuring the level of Ca +2 ions in the specimen. Concentrations of 50% or greater of ethanol virtually eliminated calcium accumulation in the porcine aortic valve specimens as compared to glutaraldehyde-pretreated controls. Example 2 Studies were conducted on porcine aortic valve specimens to determine the length of time of exposure to the alcohol treatment solution which is required for optimal anticalcification effects. FIG. 2 is a graphical representation of the calcium content (μg/mg) of glutaraldehyde-pretreated porcine aortic valve cusp specimens, following 21 day implantation in rat subdermal pouches, which have been exposed to 80% ethanol for periods of 24 hours and 72 hours. Typically, 72 hours of exposure to ethanol results in more calcium accumulation than 24 hours of exposure. However, calcification levels following 72 hours exposure to ethanol were nevertheless consistently below the level of controls (glutaraldehyde-pretreated porcine aortic valve cusps). The calcium content of the control specimens was 178.2±6.166 μg/mg dry tissue whereas the calcium content of the specimens which were subjected to 24 hours exposure to 80% ethanol, followed by a rinse with three 100 ml portions of HEPES buffered saline (pH 7.4) over about a 10 to 15 minute period, was 2.248±0.186 μg/mg. This represents 99% inhibition, i.e., substantial inhibition. Referring again to FIG. 2, the calcium content of ethanol treated porcine aortic valve specimens, subsequently rinsed or stored in a glutaraldehyde-containing solution, is shown. In one instance ("Glut. Rinse"), the ethanol treated specimens were rinsed in three 100 ml portions of 0.2% glutaraldehyde buffered to a pH of 7.4 (HEPES) over about a 15 minute rinse period. In the second instance ("Glut. Storage"), the ethanol treated specimens were stored in 0.2% glutaraldehyde buffered to a pH of 7.4 (HEPES) for 30 days, and then rinsed with HEPES buffered saline prior to implant. Contact with, or storage in, a glutaraldehyde-containing solution resulted in more calcium accumulation than observed in those specimens maintained free of additional exposure to glutaraldehyde. Example 3 Rinsing, or washing, was found to produce significant effects on the level of calcification in 21 day and 60 day rat subdermal implant studies as reported below in Table 1. Table 1 presents the calcium content of a set of porcine aortic heart valve specimens following implantation in a rat subdermal pouch. The specimens were untreated glutaraldehyde-pretreated porcine aortic heart valves obtained from St. Jude Medical, Inc. (control) and treated glutaraldehyde-pretreated porcine aortic heart valves which had been subjected to 80% ethanol for 24 hours. The 80% ethanol treated specimens were then subjected to a last minute "wash" (24 hour immersion in pH 7.4 HEPES buffered saline, changed hourly), or "rinse," (defined as three one minute, 100 ml rinses with pH 7.4 HEPES buffered saline). Additional 80% ethanol treated specimens were stored in a solution of 80% ethanol and 0.2% glutaraldehyde buffered to a pH of 7.4 (HEPES) for 1 month and then subjected to a "rinse" or TABLE 1______________________________________ 21 day 60 dayTreatment Group Ca.sup.+2 (μg/mg) Ca.sup.+2 (82 g/mg)______________________________________Control 183.15 ± 0.03 236.3 ± 6.1480% ethanol/rinse 11.1 ± 6.04 14.6 ± 10.580% ethanol/wash 5.16 ± 1.72 1.87 ± 0.2980% ethanol/Glut. storage/rinse 3.13 ± 1.67 22.9 ± 8.1480% ethanol/Glut. storage/wash 4.11 ± 2.4 18.3 ± 8.31______________________________________ Specimens of glutaraldehyde-pretreated bovine pericardium were treated in 80% ethanol followed by a 24 hour wash. The calcium content of rat subdermal implants following 21 days was 2.95±0.78 μg/mg. In comparison, the calcium content of untreated control specimens was 121.16±7.49 μg/mg. Example 4 Studies were conducted with glutaraldehyde-pretreated porcine aortic heart valve specimens in order to assess efficacy of the method of the present invention for calcification-resistance in vivo. Glutaraldehyde-pretreated porcine heart valve specimens were obtained from St. Jude Medical, Inc. (St. Jude) and from Medtronic, Inc., (Hancock I). Control specimens were not exposed to alcohol treatment. Experimental specimens were subjected to 80% ethanol for 72 to 96 hours. Control and experimental specimens were implanted in juvenile sheep as mitral valve replacements. Five months after implant, the valves were explanted and analyzed for calcium content. The results are shown in FIG. 3 which is a graphical representation of the calcium content (μg/mg) of the explanted specimens (10 sheep per group) at 150 days. Complete inhibition of calcification is shown by ethanol treatment. For comparative purposes, the calcium content of fresh, unimplanted porcine aortic heart valve specimens is shown. Example 5 While not wishing to be bound by a particular theory, it is postulated that the alcohol irreversibly alters the devitalized membrane of glutaraldehyde-pretreated bioprosthetic tissues. Proton NMR studies show an altered association with water following alcohol treatment. Table 2 shows the T1 and T2 relaxation times for proton NMR measurements (7.5 Tesla instrument) conducted on fresh porcine aortic heart valve specimens, as well as glutaraldehyde-pretreated specimens and glutaraldehyde-pretreated specimens which have been subjected to treatment in 80% ethanol in accordance with the principles of the invention. Treatment with ethanol results in significantly prolonged T1 and T2 relaxation times indicating a water-rich environment which is much less conducive to calcium phosphate precipitation. TABLE 2______________________________________ T1 (sec) T2 (msec)______________________________________Untreated 1.84 ± 0.19 0.14 ± 0.1Glutaraldehyde 1.78 ± 0.31 0.30 ± 0.05Ethanol 2.36 ± 0.36 0.42 ± 0.027______________________________________ *Porcine aortic heart valve leaflets: as retrieved with no treatment (UNTREATED); treated with 0.6% glutaraldehyde (GLUTARALDEHYDE; treated with 80% ehtanol (ETHANOL.) All treatment solutions were buffered to pH 7.4. Example 6 Alcohol treatment almost completely removes all cholesterol and phospholipids from the tissue and appears to block the uptake of plasma lipoproteins into the biomaterial. Specimens of glutaraldehyde-pretreated porcine aortic valves (cusps) were subjected to treatment in 40% ethanol, 80% ethanol, and detergent (1% SDS) for 24 hours. Untreated, glutaraldehyde-pretreated porcine aortic valve specimens were used as the control. The specimens were placed in a solution of 14 C-cholesterol in bovine serum for 24 hours. FIG. 4 is a graphical representation of the cholesterol content, in μg/mg, of the treated specimens and the control. Cholesterol uptake by porcine aortic valve specimens was found to be diminished in specimens subjected to 80% ethanol for 24 hours, possibly indicating a permanent material effect which blocks the uptake of plasma lipoproteins. Detergent-treated tissue exhibited significantly higher cholesterol uptake. Table 3 presents the total cholesterol (CS) and phospholipid (PL) content of glutaraldehyde-pretreated porcine aortic valve specimens treated for 24 hours in either buffered aqueous solutions of alcohol or chloroform-methanol as identified therein. TABLE 3______________________________________GROUP Total CS* (nmole/mg) PL* (nmole/mg)______________________________________Control (glu.) 13.34 ± 0.41 17.24 ± 0.8540% Ethanol 13.96 ± 0.71 16.5 ± 1.4960% Ethanol 0.30 ± 0.05 4.93 ± 1.9180% Ethanol 0.14 ± 0.02 1.08 ± 0.11 1% SDS 1.40 ± 0.1 0.94 ± 0.052:1 CHCl.sub.3 :Methanol 0.10 ± 0.0 0.57 ± 0.0780% Methanol 0.28 ± 0.02 2.62 ± 0.3680% Acetone 0.12 ± 0.02 1.94 ± 0.3280% Acetonitrile 0.16 ± 0.04 2.76 ± 0.28______________________________________ *Mean ± SEM (N = 5) As shown in Table 3, 80% ethanol exposure removes virtually all of the cholesterol and phospholipids contained in the porcine aortic valve tissue. Detergent (SDS) had a significantly diminished effect on tissue cholesterol and phospholipid content as compared to 60% or greater ethanol. Example 7 Other solvents which are also known to extract cholesterol and lipids were investigated for possible anticalcification effects. Specimens of glutaraldehyde-pretreated porcine aortic valve cusps (control) were subjected to: 80% methanol, 80% isopropanol, 80% ethanol, chloroform/methanol (2:1), 80% acetonitrile, and 80% acetone for 24 hours. The specimens were implanted in subdermal pouches in rats for 21 days and the calcium content was ascertained at explant. The results are shown graphically on FIG. 5. While methanol and acetone exhibited comparable anticalcification effects to that of ethanol, the use of these solvents is problematic inasmuch as residual methanol is potentially toxic in an implantation environment and acetone may be carcinogenic. Surprisingly, chloroform/methanol, which is the standard solution for extracting lipids, was significantly less effective than ethanol. In another related study, a combined concentration effect was observed with 40% ethanol and 40% acetone. Individually, neither of these solvents are effective at 40% concentration (see, FIG. 1 for ethanol efficacy at 40% concentration). The calcium content of implanted porcine aortic heart valve specimens which were subjected to 40% acetone, after 21 days in a rat subdermal pouch, was 141.07±28.91 μg/mg. Whereas, the calcium content of specimens subjected to a mixture of 40% ethanol and 40% acetone was 1.54±0.16 μg/mg. Thus, a mixture of two or more solvents may be utilized in the practice of the invention provided that the combined volume of the organic solvents is greater than 50%. Example 8 T s , which is an important measure of material strength, durability, and integrity, is almost completely unaffected by the ethanol treatment of the present invention as shown in FIG. 6. FIG. 6 is a graphical representation of the collagen denaturation temperature (°C.) for specimens of glutaraldehyde-pretreated porcine aortic valves (cusps) subjected to various treatment schemes, specifically 24 hours of exposure to ethanol (80% or 100%) and detergent (SDS). The schemes include: 80% ethanol without rinsing; 100% ethanol without rinsing; 100% ethanol followed by washing with HEPES buffered saline for 1 hour; 80% ethanol followed by rinsing with HEPES buffered saline and storage in 0.2% glutaraldehyde for 24 hours; 1% SDS followed by a HEPES buffered saline rinse; and 1% SDS followed by washing with HEPES buffered saline for 1 hour. The controls were glutaraldehyde-pretreated porcine aortic valve specimens obtained from St. Jude Medical, Inc., either as received ("Glut."), or as rinsed and stored in pH 7.4 HEPES buffered saline for 24 hours ("Glut./Buffer"). Differential scanning calorimetry was used to obtain the data. Ethanol treatment, followed by aqueous rinsing and appropriate storage conditions, had no effect on T s , whereas detergent treatment significantly lowered T s . Differential scanning calorimetry was used to ascertain the amount of time required to rehydrate porcine aortic valve specimens after exposure to 80% ethanol for 24 hours. As used herein, the term "rehydrate" refers to restoring T s to the value of control (glutaraldehyde-pretreated porcine aortic valve specimens which were rinsed in pH 7.4 HEPES buffered saline for 24 hours). The ethanol treated specimens (cusps) were subjected to HEPES buffered saline (pH 7.4) for varying time periods, ranging from a rinse (i.e., pouring rinse solution over the specimen) to one hour. The results are shown in Table 4. A two minute rinse returns T s of the treated specimens to a value which is not significantly different, statistically, from the T s value of the control. TABLE 4______________________________________Treatment Rinse Period T.sub.s (°C.)______________________________________Control 24 hrs 88.33 ± 0.5680% EtOH rinse 84.06 ± 0.3280% EtOH 1 min. 84.49 ± 0.3980% EtOH 2 min. 87.41 ± 0.2380% EtOH 5 min. 87.8580% EtOH 10 min. 87.5480% EtOH 1 hr 87.38 ± 0.26______________________________________ Example 9 The overall protein composition and valvular morphology of porcine aortic valves are unaffected by alcoholic treatment as demonstrated by complete amino acid analysis and electron spectroscopy for chemical analyses (ESCA). In fact, alcohol treatment enhances surface smoothing and anisotrophy of porcine aortic valve leaflets resulting in a surface chemistry which is comparable to fresh leaflets. In contrast, glutaraldehyde-pretreated (control) or detergent (SDS) treated tissue show significant differences. Table 5 hereinbelow presents ESCA data of the surface carbon (C1s), nitrogen (N1s), and oxygen (O1s) concentrations (%) in porcine aortic valve specimens immersed for 24 hours in the indicated solution. TABLE 5______________________________________ ATOMIC CONCENTRATION (%)GROUP O1s N1S C1s______________________________________Fresh Tissue 20.41 10.06 69.5280% Ethanol 21.89 11.93 66.1840% Ethanol 16.45 7.78 75.76Glutaraldehyde-Fixed 14.46 7.22 78.32 1% SDS 19.03 7.37 73.62:1 CHCl.sub.3 /MeOH 22.71 15.85 61.44______________________________________ Complete amino acid analyses of ethanol treated, glutaraldehyde-pretreated porcine aortic valves as compared to glutaraldehyde-pretreated porcine aortic valves revealed that ethanol treatment has virtually no effect on the amino acid compositions, i.e., ethanol treatment does not extract to any significant extent any of the protein components of bioprosthetic tissue. Functional in vitro testing for mechanical and physiologic valve function demonstrated that mechanical functioning is improved by ethanol treatment in accordance with the present invention. Example 10 In a series of experiments to exemplify additional embodiments of the invention, specimens of glutaraldehyde-pretreated porcine aortic valves were treated with 60% ethanol in a variety of protocols. Although the term "porcine aortic valves" generally includes both the valve cusps, or leaflets, and an aortic wall portion, the prior experiments reported hereinabove were conducted primarily on valve cusp tissue. In the present experiments, the two types of tissue have been separated and the data reported separately on Table 6. Glutaraldehyde-pretreated bioprosthetic heart valve specimens, obtained from St. Jude Medical, Inc., were used as controls. Specimens of the glutaraldehyde-pretreated tissue were then subjected to treating solutions of 60% ethanol, or 60% ethanol and O.1M AlCl 3 , for 24 hours. Following ethanol treatment, the tissue was rinsed for 24 hours in neutral buffer, specifically HEPES at pH 7.4. Subsequent to rinsing, the tissue samples were sterilized and stored for 14 days. In some storage protocols, the tissue was packaged in neutral buffer and subjected to sterilizing radiation. In other storage protocols, the tissue was stored in solutions of 60% ethanol and glutaraldehyde (0.2% or 0.5%). In yet further storage protocols, the storage solution additionally contained 0.1M AlCl 3 . The tissue samples prepared as described above were implanted in rat subdermal pouches and analyzed for calcium content after 21 days. The results are reported below in Table 6. TABLE 6__________________________________________________________________________Exp. Storage μg Ca/MgNo. Treatment Rinse (14 Days) Cusp Wall__________________________________________________________________________1 24 hr 24 hr Buffer + Irrad. 13.763 ± 3.550 40.892 ± 6.057 60% EtOH2 24 hr 24 hr Buffer + Irrad. 6.836 ± 0.262 2.75 ± 0.745 60% EtOH + 0.1 M AlCl.sub.33 24 hr 24 hr 60% EtOH + 9.157 ± 3.733 50.470 ± 1.628 60% EtOH 0.2% Glut.4 24 hr 24 hr 60% EtOH + 7.029 ± 0.592 7.110 ± 0.915 60% EtOH + 0.2% Glut. 0.1 M AlCl.sub.35 24 hr 24 hr 60% EtOH + 8.791 ± 2.716 49.082 ± 4.217 60% EtOH 0.5% Glut.6 24 hr 24 hr 60% EtOH + 8.689 ± 0.367 8.449 ± 0.341 60% EtOH + 0.5% Glut. 0.1 M AlCl.sub.37 none none 60% EtOH + 1.952 ± 0.446 60.690 ± 4.7168 none none 60% EtOH + 10.326 ± 0.635 12.782 ± 3.469 0.2% Glut. + 0.1 M AlCl.sub.39 none none 60% EtOH + 7.907 ± 3.635 39.810 ± 5.026 0.5% Glut.10 none none 60% EtOH + 9.568 ± 0.240 7.763 ± 0.368 0.5% Glut. + 0.1 M AlCl.sub.3Control -- -- 107.059 ± 3.239 49.915 ± 2.160(No Treatment)__________________________________________________________________________ As shown in Table 6, in embodiments where the biomaterial is specifically aortic wall tissue, incorporation of Al +3 in the treatment solution, or storage solution, results in much greater inhibition of calcification than treatment with an alcohol solution. Example 11 Specimens of the glutaraldehyde-pretreated porcine aortic wall tissue were subjected, for 24 hours, to aqueous (pH 7.4 buffered HEPES) treating solutions of 0.1M FeCl 3 ; 0.01M FeCl 3 ; 80% ethanol; 80% ethanol and 0.1M FeCl 3 ; and 80% ethanol and 0.01M FeCl 3 . Following treatment, the tissue was rinsed in three 100 ml portions of neutral buffer, specifically HEPES at pH 7.4. Specimens of glutaraldehyde-pretreated porcine aortic wall tissue, obtained from St. Jude Medical, Inc., were used as controls. The tissue samples, prepared as described above, were implanted in rat subdermal pouches and analyzed for calcium content after 21 days. The results are reported below in Table 7. TABLE 7______________________________________TISSUE PRETREATMENT WASHING Ca (μg/mg)______________________________________Porcine Control No 36.46 ± 4.04Aortic 0.1 M FeCl.sub.3 Rinse 13.37 ± 1.5Wall 0.01 M FeCl.sub.3 Rinse 13.52 ± 2.93 80% EtOH Rinse 18.55 ± 3.61 80% EtOH + Rinse 6.31 ± 0.55 0.1 M Fe 80% EtOH + Rinse 7.01 ± 1.03 0.01 M Fe______________________________________ Table 7 demonstrates that incorporation of Fe +3 ions in the alcohol treatment and/or storage solutions will produce improved resistance to calcification for porcine aortic wall specimens. Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope or departing from the spirit of the claimed invention. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof.

A method of treating a collagenous biomaterial, such as porcine aortic valve leaflets or bovine pericardium, by exposing the biomaterial to an alcohol to inhibit in vivo calcification. The biomaterial, preferably glutaraldehyde-pretreated, is subjected to an aqueous solution of 60% to 80% lower aliphatic alcohol, such as ethanol for a period of at least 20 minutes, and preferably, 24 to 72 hours. The biomaterial is rinsed, and then stored in either a glutaraldehyde-free environment or an ethanolic solution of glutaraldehyde. In some embodiments, the treatment solutions include an additional anticalcification agent which may be a soluble salt of a metallic cation, such as Al +3 or Fe +3 .

BACKGROUND OF THE INVENTION [0001] This invention relates to a method and apparatus for collimating or collecting light for detection. More particularly, the invention is directed to a technique for detecting the edge of an object using an apparatus having a plurality of barriers or shield structures that are advantageously aligned with an optical sensor array to collect or spatially filter generated light for improved detection of the light. The invention also relates to methods of forming the structure. Application of the invention is found in the field of detecting edges of objects such as sheets of paper that are fed through imaging devices along a paper path. [0002] While the invention is particularly directed to the art of collecting or collimating light in the context of detecting edges of objects (for example, sheets of paper) using optical sensors, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications. For example, the invention may be used in any application where waves, such as light waves and sound waves, are generated and detected for a particular purpose. [0003] By way of background, there is a need for collimated optical systems that provide a large depth of focus with high spatial resolution over large areas. In this regard, there is a need for inexpensive, efficiently implemented optical detection systems that are useful for detecting the edges and/or position of paper in imaging applications. [0004] In the past, laser arrays have been proposed for this purpose. However, arrays of lasers are relatively expensive, and therefore undesirable, to implement. [0005] Various optical sensing arrays are known in the imaging field. For example, U.S. Pat. No. 5,121,254 describes an image transmitting element and process for producing a photo-shield spacer plate used therein. This patent, however, does not describe any use of the device to detect edges or the position of paper in imaging applications. Moreover, because lenses are used in such devices, the costs are undesirably increased. Further, the process disclosed to form these devices presents a variety of difficulties, including alignment difficulties, if used to form edge detecting devices as contemplated by the present invention. [0006] Optical systems utilizing louvers are also known. However, such systems are generally only adaptable to be one dimensional and are difficult to align with known high resolution sensor arrays. [0007] The present invention contemplates a new method and apparatus for collecting or collimating light for detection that resolves the above-referenced difficulties and others. SUMMARY OF THE INVENTION [0008] A method and apparatus for collecting or collimating light for detection are provided. Specifically, a technique is provided for detecting the edge of an object using an apparatus having a plurality of barriers or shield structures that are advantageously aligned with an optical sensor array to collect or spatially filter generated light for improved detection of the light. [0009] In one aspect of the invention, the method comprises steps of transporting the object to a position between the light source and a first group of a plurality of discrete optical sensors positioned on a substrate—the first group being positioned relative to the object such that the light is substantially blocked from being detected by the first group, detecting first portions of the light by a second group of the plurality of discrete optical sensors, absorbing second portions of the light by a plurality of light absorbing barrier structures extending between the plurality of discrete optical sensors and the light source—each of the plurality of barrier structures defining a channel aligned with at least one of the plurality of sensors, and determining the location of the edge based on the detection of the light by the second group of the plurality of optical sensors. The first portions of light are directly nearly parallel to an axis of the channel and the second portions of light are directed at angles generally non-parallel to the axis. [0010] In another aspect of the invention, an apparatus for use in a system having light generated therein by a light source comprises a substrate, at least one optical sensor positioned on the substrate to detect first portions of the light, and at least one light absorbing barrier structure extending between the plurality of discrete optical sensors and the light source—the each barrier structure defining a channel aligned with the at least one sensor and being positioned to absorb second portions of the light, wherein the optical sensor detects the first portions of the light and the at least one barrier structure absorbs the second portions of the light based on a position of the edge of the object in the path. [0011] In another aspect of the invention, the at least one optical sensor is a plurality of optical sensors and each of the plurality is aligned with a barrier structure. [0012] In another aspect of the invention, the channel is substantially circular in cross section. [0013] In another aspect of the invention, the channel is substantially polygonal in cross section. [0014] In another aspect of the invention, the channel has a width and a length, an aspect ratio being defined based on the length divided by the width. [0015] In another aspect of the invention, the aspect ratio is greater than 10:1. [0016] In another aspect of the invention, the plurality of barrier structures is formed of light absorbing material. [0017] In another aspect of the invention, the plurality of barrier structures is coated with light absorbing material. [0018] In another aspect of the invention, the plurality of barrier structures extend from the plurality of sensors toward the path. [0019] In another aspect of the invention, the plurality of barrier structures extend from the light source to the path. [0020] In another aspect of the invention, a method of forming an optical sensor array device comprises steps of forming at least one optical sensor on a substrate, forming a thick film layer of light absorbing material over the substrate—the thick film layer having a thickness, forming a pattern on the thick film layer, and developing the thick film layer based on the pattern to form at least one aperture in the thick film—the at least one aperture exposing and being aligned with the at least one sensor and having a width wherein the thickness divided by the width defines an aspect ratio. [0021] In another aspect of the invention, the substrate is formed of one of glass, silicon and plastic. [0022] In another aspect of the invention, the substrate and the at least one sensor comprise a charge coupled device (CCD) array. [0023] In another aspect of the invention, the aspect ratio is approximately 20:1. [0024] In another aspect of the invention, a method of forming an optical sensor array device comprises steps of forming at least one optical sensor on a substrate, forming a thick film layer over the substrate—the thick film layer having a thickness, forming a pattern on the thick film layer, developing the thick film layer based on the pattern to form at least one aperture in the thick film—the at least one aperture exposing and being aligned with the at least one sensor and having a width, and coating the thick film layer with a light absorbing material wherein the thickness divided by the width defines an aspect ratio. [0025] In another aspect of the invention, the aspect ratio is approximately 20:1. [0026] In another aspect of the invention, the substrate is formed of one of glass, silicon and plastic. [0027] In another aspect of the invention, the substrate and the at least one sensor comprise a charge coupled device (CCD) array. [0028] In another aspect of the invention, the apparatus is flexible. [0029] In another aspect of the invention, the apparatus comprises a multi-dimensional array of optical sensors and corresponding barrier structures. [0030] In another aspect of the invention, the channels are filled with a transparent material. [0031] In another aspect of the invention, the apparatus is coated with a transparent layer. [0032] Further scope of the applicability of the present invention will become apparent from the detailed description provided below. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art. DESCRIPTION OF THE DRAWINGS [0033] The present invention exists in the construction, arrangement, and combination of the various parts of the device, and steps of the method, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which: [0034] [0034]FIG. 1 is a perspective view of a sensor array device according to the present invention; [0035] [0035]FIG. 2 is a top view of the sensor array device shown in FIG. 1; [0036] [0036]FIG. 3 is a cross-sectional view along line 3 - 3 in FIG. 1; [0037] [0037]FIG. 4 is a perspective view of an alternative embodiment of the present invention; [0038] [0038]FIG. 5 is a method according to the present invention; and, [0039] FIGS. 6 ( a )- 6 ( f ) illustrate methods of forming a sensor array device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0040] Referring now to the drawings wherein the showings are for purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting same, FIG. 1 provides a view of an overall preferred device according to the present invention. As shown, the sensor array device 10 includes a barrier structure or shield portion 12 having channels or apertures 14 disposed therein. The device 10 also includes a sensor array portion 16 . [0041] Referring now to FIG. 2, it can be seen that the apertures or channels 14 extend through the shield portion 12 to the sensor array portion 16 to expose sensor elements 18 . It is to be appreciated that the sensor elements 18 are aligned with the apertures in a precise manner. This is accomplished during the formation process, as will be described in more detail below. [0042] As shown, the channels 14 are generally circular in cross section (primarily due to the fabrication techniques) and the sensor elements are generally rectangular. However, it is to be appreciated that the channels 14 and sensor elements 18 may take a variety of shapes and forms, as will be apparent to those skilled in the art, so long as proper alignment is achieved. For example, the channels 14 may alternatively take on a shape of an ellipse or a rectangle, square, hexagon, or any other polygon. [0043] As shown in FIG. 3, a sensor array portion 16 has sensor elements, one of which is shown at 18 , positioned on a substrate 20 . Extending from the substrate 20 are barrier structures 22 which define the channels, one of which is shown at 14 . The channels each have a centerline or longitudinal axis C. [0044] An object 30 having an edge 32 is transportable along a path 34 to be positioned a distant x from the top of the device 10 . It is to be appreciated that the object 30 may be a sheet of paper and the path 34 may be a paper path disposed within an imaging device such as a printer, copier, etc. The object 30 may also comprise other types of material (e.g. sheet metal, plastic, etc.) that take the form of a sheet or web. [0045] A light source 40 is also shown in FIG. 3. The light source 40 may take a variety of forms well known to those skilled in the art and, typically, will produce overlapping fields of light 42 . [0046] As shown, the sensor array device 10 is able to detect the edge 32 of the object 30 . In this regard, when the light source is positioned as in FIG. 3, light rays generated thereby are blocked by the object 30 such that a first group of sensors A do not detect any of the light. Conversely, a second group of detectors B detect first light portions (or rays) 44 that are not blocked by the object 30 . In addition, second light portions 46 that are not blocked by the object 30 are absorbed into the barrier structures 22 . This configuration allows for more accurate detection of the edge 32 because the barrier structures 22 absorb the stray light while such structures 22 allow light rays running generally parallel to the structures to be detected by the detecting elements 18 . As a result, the shadow of the object remains generally aligned with its actual position and is not broadened to improve the precision of detection of the edge. [0047] With further reference to FIG. 3, each channel 14 includes a width d and a height or thickness L. Of course, it is to be appreciated that the cross-section of the channels 14 may vary. For example, as noted above, the channels may be substantially circular, elliptical, or polygonal in cross-section. However, for simplicity, the various dimensional relationships will be explained in connection with a generally square cross-sectional tube. It is to be appreciated that the view shown in FIG. 3 that was noted as having circular cross-sectional channels (which in cross section also resembles a square cross section) will be used to explain the dimensional relationships for convenience. [0048] More particularly, the variation of sensitivity with paper height x depends on the form of illumination used, e.g. reflected from the paper or top side incident light eclipsed by the sheet. For the latter case with square cross-section channels, the response of the sensor is that of the unblocked sensor for an edge position d/ 2 (1+2x/L) to the left of the channel centerline or axis C and linearly decreases to the response of a blocked sensor when the edge 32 moves to a position d/ 2 (1+2x/L) to the right of the channel in FIG. 3. The quantity d is the width of the channel and L is the length of the channel. The response of the detector as a function of edge position therefore extends over a region d(1+2x/L). [0049] Another relational characteristic of the device according to the present invention is the aspect ratio. For purposes of the invention, the aspect ratio is defined as the height or thickness L of the barrier structures divided by the width d. Preferably, this ratio A=L/d is such that broadening is less than the channel width for the desired object stance x. In other words, d≧2x/A defines a desirable aspect ratio. For d=100 μm and x=1 mm, the aspect ratio A should be greater than 20. In many circumstances, an aspect ratio of greater than 10:1 will suffice. [0050] It is to be recognized that the configuration shown in FIG. 3 may vary depending on the particular application. For example, the barrier structures 22 may be positioned to alternatively collect and/or collimate the light directly from the light source, as opposed to providing barriers in contact with the sensor array portion 16 . For edge detection in this case, the object edge 30 is placed between the sensor array 18 and the barrier structures 22 . Modifications to the system to implement such an alternative will be readily apparent to those skilled in the art. However, as an example, it is contemplated that the barrier structures could be positioned between the light source and the object 30 (or its path) such that the light source has portions aligned with the channels 14 , which are in turn remotely aligned with each sensor 18 . A light source comprised of LEDs would accommodate this configuration. [0051] Another variation of the system is to replace the discrete detectors 18 with continuous detectors such as position sensitive detectors. Such continuous detectors are well known to those skilled in the art. Charge coupled devices (CCD's) are also contemplated for use with the present invention. [0052] A still further alternative to the configuration shown in FIG. 3 is to position the light source such that light is reflected from the bottom 31 of the object 30 and detected by the optical elements 18 , for example. In this case, of course, optical sensor elements and corresponding barrier structures that lie between the light source and the object would be detecting and/or absorbing light (i.e. reflected light) as opposed to the other sensor elements (and structures) as contemplated by FIG. 3. [0053] As thus far described, the sensor array device 10 is a one dimensional array that is particularly useful for detecting the edge of objects such as paper in an imaging device. However, a number of sensor array devices may be arranged or positioned together to form a two dimensional array which, as those skilled in the art will appreciate, could usefully detect the position of paper or other objects. In this regard, with reference to FIG. 4, a two dimensional array device 100 is shown. This device includes sensor array devices 10 ′, 10 ″, and 10 ′″. It is to be appreciated that these sensor array devices are substantially identical to the sensor array device described in connection with FIGS. 1 - 3 . Of course, modifications to any system incorporating the device 100 to determine position will be apparent to those skilled in the art. [0054] In addition, in another alternative embodiment, the sensor array device is formed of materials that are flexible. The flexible materials selected may vary in composition and may be selected from a variety of such materials that are well known in the art such as dielectric coated stainless steel, polyimide and thin glass, the former two being preferred. As such, the devices are positioned and flexed, or curved, to conform to object paths that are curved. [0055] In still further alternative embodiments, the array may be coated or provided with a thin layer of transparent material (such as polyethylene, polyester, or glass that is thermally or adhesively bonded) and/or the channels may be filled with a transparent material for purposes of protection and durability. The specific transparent fill material used may be selected from a variety that are well known and used in the field of optics including transparent polymer materials or ultraviolet curing epoxy material. Of course, preferably, these alternatives will not interfere with achieving the objectives of the invention. [0056] Referring now to FIG. 5, a method 500 according to the present invention is described. Initially, the object (e.g. paper) is transported along a path to a position between a light source and a first group of a plurality of discrete optical sensors positioned on a substrate, preferably with barrier structures (step 502 ). It should be appreciated that the first group is positioned relative to the object such that the light is substantially blocked from being detected by the first group. This is illustrated in FIG. 3. First portions of the light are then detected by a second group of the plurality of discrete optical sensors (step 504 ). The first portions of light are generally directed in nearly parallel fashion to the axes of the channels. Again, this is illustrated in the configuration of FIG. 3. [0057] Second portions of the light are absorbed by a plurality of light absorbing barrier structures extending between the plurality of discrete optical sensors and the light source (step 506 ). The second portions of light are generally directed at angles that are substantially non-parallel to the axes of the channels. The location of the edge of the object is then determined based on the detection of the light by examining the light intensity falling on both groups of sensors (step 508 ). [0058] It is to be appreciated that the state of the sensors is detected by hardware and software that are well known to those skilled in the art. Likewise, the determination of the precise location of the edge relative to the system is well known and may be accomplished using various hardware and software techniques. Thresholding or curve fitting are two such examples. [0059] Of course, this method according to the invention will be modified in the event that the configuration of the system shown, for example, in FIG. 3, is modified. For example, if light source 40 is positioned to reflect light from the bottom of the paper to the sensors, the paper is transported to a position in the path such that the light may be sufficiently reflected as opposed to being transported to a position between the light source and a plurality of sensors. [0060] Whether a sensor array device 10 or a multi-dimensional device, such as the two dimensional sensor array device 100 , is formed, it can be conveniently batch fabricated. In this regard, the batch fabrication may be accomplished via thick film photolithography using, for example, SU-8 or anodized aluminum electro-etching or using other known means to create high aspect ratio, thin, vertical wall structures in closed packed arrays of channel. Indeed, photolithographic means of formation is preferred according to this invention because of its inherent ability to align the sensor elements with the channels. Prior art configurations of shields or the like do not provide formation techniques that accomplish the alignment objectives of the present processes. [0061] More particularly, with reference to FIGS. 6 ( a )-( f ), the formation process begins with the provision of a substrate 16 (FIG. 6( a )). Optical sensors 18 are then formed on the substrate 16 (FIG. 6( b )). It is to be appreciated that the substrate may be glass (preferably), plastic, dielectric-coated metal, or silicon. It is to be further appreciated that the sensor may take the form of any variety of optical sensors that are well known in the art and can be formed on the substrate in a variety of manners. [0062] A thick film layer of material 622 is then formed over the substrate to a thickness L (FIG. 6( c )). The thick film layer is preferably formed by spin coating but lamination or molding will suffice. The thick film layer may also be of a material that is light absorbing such as the preferred SU-8 or anodized aluminum or, as will be described later, a light absorbing coat could be applied to the barrier structures when completed. [0063] A pattern 624 is then formed on the thick film layer by, for example, illumination with ultraviolet light through a mask (FIG. 6( d )). Holes are then created in the thick film to define the apertures 14 and the barrier structures 22 (FIG. 6( e )). Creation or development of the holes can be accomplished, for example, by etching or dissolution, as those skilled in the art will appreciate. [0064] If the thick film layer is formed of a material that is light absorbing, then the formation process is complete. However, if the material is not light absorbing, a coat 626 of light absorbing material is applied to at least the inner surfaces of the channels 14 (FIG. 6( f )). Suitable light absorbing materials are well known to those versed in the art. [0065] The process described in FIGS. 6 ( a )- 6 ( f ) is the preferred formation process for the devices according to the present invention. However, it is to be appreciated that other processes can be used to form the structures so long as the objectives of the present invention are achieved. For example, additional steps could be implemented to coat or provide the array with a thin transparent layer or fill the channels with a transparent material for purposes of protection and durability. Such steps may include the trimming of excess fill material using, for example, a doctor blade. In addition, processes could be implemented to form an apparatus that is flexible for flexing and positioning in a curved, 3-dimensional path. [0066] The above description merely provides a disclosure of particular embodiments of the invention and is not intended for the purposes of limiting the same thereto. As such, the invention is not limited to only the above described embodiments. Rather, it is recognized that one skilled in the art could conceive alternative embodiments that fall within the scope of the invention.

This invention relates to a method and apparatus for collecting or collimating light for detection. More particularly, the invention is directed to a technique for detecting the edge of an object using an apparatus having a plurality barriers or shield structures that are advantageously aligned with an optical sensor array to collect or spatially filter generated light for improved detection of the light. The invention also relates to methods of forming the structure. Application of the invention is found in the field of detecting edges of objects such as sheets of paper that are fed through imaging devices along a paper path.

BACKGROUND OF THE INVENTION The invention relates to a method for producing individual material sections, more particularly, sheets of paper, according to a certain format, from a web-type, for example, imprinted object (object web), more particularly, a web of paper, fabric, plastic, or metal foil, wherein at least one separating means is used, with which the individual material sections are cut from the object web and are then removed from the cutting means. During the course of the cutting process or the actuation of the cutting means, at least one carrier is engaged with the object web. The invention further relates to a corresponding device for separating individual material sections, according to a certain format, from a web-type object (object web), wherein a cutting tool that can be brought into functional connection with the object web is provided, along with one or more transporting or conveying means. The latter are embodied for removing the separated material section once it has been cut off by the cutting tool. The transporting or conveying means comprise at least one carrier, which is embodied for engaging with and/or gripping the object web. The invention further relates to a method for folding a material section, which can be an imprinted sheet of paper, for example, and has been produced particularly according to the above-described production and/or separation method. In this, a folding element is pressed against the cut-off material section in the region of an intended folding line. The invention further relates to a corresponding device for folding the material section, comprising a folding tool, which can be placed in engagement with the material section in the region of the intended folding line. Additionally, a gripper or some other type of carrier is allocated for interacting with the folding tool. The carrier can be placed in functional connection with or disconnected from the material section by means of a servo device. Finally, the invention relates to a cutting and folding assembly for material in web or sheet form, for example, an imprinted paper web or imprinted sheets of paper, wherein the above-described separating and folding devices can be used. Folding units are known in the field of printing machines, for example, for web-fed offset machines. The embodiment of said units as jaw folding units is particularly common. Coming from a fold former, a strand or an object web first reaches a cross-cutting unit, which consists of a two-part cutting blade cylinder, for example, which operates opposite a three-part folding blade cylinder. For this purpose, the latter is equipped with three cutting bars made of a flexible but sturdy material. The cutting blade is serrated in the manner of a saw, and executes a punching cut, in which the ends of the sheet, after being cut, therefore also appear serrated. The manner of folding by way of folding blade and folding jaw is characteristic of a jaw folding unit. To accomplish this, after cutting, a three-part folding blade cylinder and a two-part folding jaw cylinder, for example, interact. The jaw fold is produced in that, at the point of contact between folding blade and folding jaw cylinder, the folding blade emerges, cam-controlled, from the periphery of the cylinder, thereby forcing a multilayered, cut strand packet (sheets), for example, into the opened folding jaw, which is also cam-controlled. The folding jaw, which consists of a spring-mounted steel bar with an opposite bar, then immediately closes, and holds the (folded) product securely in place as the cylinder continues to move. After the folding process, the folding jaw reopens under cam control, and separation tongues that engage in grooves in the cylinder remove the folded product from the cylinder surface and allow it to fall, under gravitational and centrifugal force, leading with the spine of the fold, into a paddle wheel, where the product is braked between the curved paddles and is delivered in a fanned form (cf., Kipphahn (editor): Handbuch Printmedien [Handbook of Print Media], Springer Verlag 2000, pages 298-300). EP 0 335 190 B1 discloses a folding unit comprising a collecting and folding cylinder. In addition to this cylinder, a cutting cylinder and a folding jaw cylinder are also provided. EP 1 247 757 A1 describes a printed sheet folding device comprising a saddle-shaped folding blade, on which the printed sheets are folded in continuously running operation. The folding blade has a vertical, internal guiding element, which interacts with an outer, revolving folding element in the form of a revolving conveyor belt for folding the printed sheets. DE 29 17 616 C2 describes a folding blade drive, which has a traveling linear motor. With every stroke of the secondary part of the motor, a folding blade is pressed in a downward direction, and presses a sheet to be folded between two folding rollers having stationary axes of rotation. The two opposite folding rollers continue to transport the folded sheets. A substantially similar folding assembly is also disclosed by DE 198 43 872 A1. DE 10 2008 012 812 A1 describes a folding machine for a printing press. The folding machine comprises, among other elements, a folding cylinder, a holding cylinder, a conveyor belt section, a chopper folding device, two folding blade wheels and discharge conveyor devices. On the periphery of the folding cylinder, two pairs of folding blades are provided at intervals of approximately 180°. Also provided on the periphery of the folding cylinder are a pin device for web conveyance and a severing blade for severing the web. The folding cylinder presses the pins of the pin device onto the leader of the web and rotates while holding the web still. The chopper folding device comprises, among other elements, a chopper blade, which is moved back and forth vertically through a loop movement of a chopper arm, at a predefined timing sequence. DE 100 55 582 A1 describes a device and a method for cutting a web, to be applied in web-fed rotary printing presses. Said device and method are provided for cutting a web into signatures of variable section lengths. To this end, the device is equipped with a plurality of cutting elements, which are movable in a straight line in the web direction for cutting the web into signatures, and is equipped with a plurality of gripper elements, which interact with the cutting elements. The cutting elements are moved in the signature cutting region in a straight line in the web direction. The signatures are gripped, and the length of the signatures is adjusted by controlling the distances between the cutting elements. Because the cutting elements and the gripper elements are able to enter the signature cutting region in a controlled manner, the signature length can be adjusted by controlling the distance between successive pairs of cutting and gripper elements in the signature cutting region. DE 200 00 554 U1 describes a cutting press for cutting workpieces out of a foil. A height-adjustable cutting tool is disposed above a press bed plate. On both sides of the press bed plate, storing parts for blanked parts that have been blanked by the cutting tool are provided. Two cutting tools are rigidly connected to one another and can be moved together transversely such that one storing part is always covered by a cutting tool when the other cutting tool is positioned above the press bed plate. This enables an automatic delivery of blanked parts at the highest possible production speed. DE patent publication 840 551 discloses a device for the incremental forward movement and the periodic cutting off of a packaging tape in an automatic folding machine. After each cutting process and before subsequent forward movements, the part of the tape that is to be cut off in the subsequent cutting operation is automatically retracted by an adjustable amount. Also provided are means for executing a control movement of constant amplitude and a loop-type sliding track, the position of which during operation can be adjusted as desired. In the sliding track, a sliding block is disposed for executing back and forth movements in the sliding track. This sliding block transfers a component of the back and forth movement to elements that are engaged with the tape, for the purpose of retracting said tape. DE 101 33 213 A1 describes a cutting device for plate-type building panels. The cutting device is structured in the form of a table. A turntable, which is swivelable about its vertical axis, is recessed in the table surface, and has a blade clearance which is such that the cutting and milling tools acting from above and below on the plate-type building panel that is to be cut execute a longitudinal movement along the blade clearance. A cut extending transversely to the direction of transport of the building panel is also enabled thereby. The plate-type building panels are moved floating on a cushion of air above the table surface. Particularly in the case of rotating folding units having rotating cutting blade cylinders, folding blade cylinders and folding jaw cylinders, the definition of the circumference of the folding blade cylinder results in a definition of a specific, whole-number multiple of the folding format to be produced (section length). More particularly, the folding blade cylinder and the cutting blade cylinder are implemented as rotating components with defined circumferential ratios. These ratios, together with the associated folding jaw cylinder, are geared for one print format. The folding format or the section length, which is determined according to the distance between the cutting tools on the outer surface of the cutting cylinder, is thus permanently established for the printing press in advance, and thereafter can no longer be adjusted. SUMMARY OF THE INVENTION In contrast to the above, a method is described for producing material sections according to a certain format using the corresponding separating device also described herein, and the folding method described herein using the corresponding folding device described herein are proposed. An assembly comprising a combination of the separating or cutting device and the folding device according to the invention is described herein. Optional, preferred embodiment examples and configurations of the invention also described. The known embodiment comprising cylinders, wherein the circumferential ratios and the arrangement of tools on sections of the circumference of said cylinders determine the format that can be processed, is replaced by an arrangement of tools and tool supports on linear guides and cross tables. According to a preferred embodiment example, said linear guides and cross tables lie in pairs opposite one another, and are each disposed adjacent to the material web/object web. Thus the reciprocal, particularly alternating action of said elements on the material web is enabled. Due to the optional use of multiple linear guides integrated into cross tables, arcuate movements of the tool supports can also be carried out. These movements can be synchronized in sections with the transport speed of the material web/fabric panel. Because within the scope of the invention, the coupling of a circumferential speed of a cylinder, for example, a cutting blade cylinder or folding blade cylinder, with the transport speed of a material web is eliminated, any variable section lengths or folding formats can be realized. This is enabled by the free motion control of the tools that are not engaged with the material web (for example, cutting blades, grippers or spur needles), along with the mounts and drive systems thereof. When printing machines are in use, the object to be processed can be received from a known former apparatus. At the end of the separating and folding process, the folded products can be transferred in a customary manner to a paddle wheel or a belt delivery system. Therefore, the invention allows increased flexibility of the folding system or folding apparatus to be achieved, without requiring any changes to system parts disposed upstream or downstream thereof. The separating and folding assembly according to the invention is suitable for use with any type of materials, more particularly, for those materials that can be transported only via the action of a tractive force (for example, paper, fabric, foils). The solution according to the invention is particularly characterized by the following aspects: The tool elements provided for acting on the object web, and linearly guided according to the invention, are arranged in pairs, along and on both sides of this object web. A reciprocal engagement of the tool elements on the object web, for example, in a push-pull process, is thereby enabled. Only during the time segment of engagement with the object web or material web must the relevant tool element be moved synchronously with said object web or material web. The linear guides for the folding blade and for the folding jaw gripper are also located to the left and the right, or on both sides, of the (already cut) material section. The drive system for the folding system according to the invention is implemented substantially by linear drives. The corresponding linear axes or linear guides can overlap one another across a plurality of linear drives. Thereby, curved movements or arcuate displacement paths can be implemented in one plane (in the manner of known cross tables). As a result of the overlapping of two linear movements, for example, a tool, which is mounted and guided in a two-axis guidance system, for example, a cross table, travels any movement path, even a curved, arcuate movement path, in a single plane. In this, there are segments of a movement path in which the tool held on the cross table is to be engaged with the material web. In these segments, the tools must move synchronously with the direction of transport of the material web or object web, since otherwise said webs will tear. In web sections where there is no engagement, the tools can move asynchronously, since, for example, they are moved opposite the direction of transport of the material web or object web. Within the scope of the invention, in replacing the cutting blade cylinders and folding blade cylinders, the tools for processing the object web and/or the separated material section are variably positioned by way of the linear drives. Said linear drives support, for example, a cutting blade and the corresponding opposite element, the cutting bar. The cut products (material section) are guided between parallel linear drives, for example, with spur needles. With the replacement of the folding blade cylinder and the other folding rollers by gripper elements or other tool elements on linearly guided tool supports, according to the invention, even arcuate paths can be implemented in sections, synchronously with the material web or with the material section, by applying the cross table principle. According to the invention, the cutting blade cylinders, folding blade cylinders and folding jaw cylinders used in known folding units are replaced by an assembly comprising a plurality of linear drives. More particularly, if said linear drives are equipped with displaceable carriages, different displacement profiles, from which different section lengths and/or variable folding formats can then be derived, can be achieved through variable control. On the basis of the invention, the control of the movement of the object web tools or material section tools is carried out independently of the object web when said tools are not engaged with the object web. This effect can be utilized to achieve an increase in flexibility and variability. The following advantages over the prior art can be achieved with the invention: The folding format and/or the section length can be flexibly adjusted according to user requirements. The section length can even be modified during an ongoing production run, and can even be adjusted as desired within a wide range of parameters. By replacing the cylinders with linear drives, a reduction in the masses that are moved, and therefore a faster shutdown of the machine are achieved. The safety level is thereby raised. In the case of a web tear or a severing of the web (i.e., the object web is deliberately cut through by special elements upstream of the folding unit) the linearly moved tool elements, which are engaged with the object web, can be quickly opened and separated from the object web. This reduces the quantity of waste paper that is produced. The motion principle that is generally used according to the invention is the synchronized, alternating arresting and pulling of the object web. The web can be arrested using spur needles, suction chambers, electrostatic membrane actuators or even adhesive elements. For supporting and guiding the object web tools and object web gripper elements, multiaxis drive systems and/or guidance systems, particularly cross tables, having a plurality of combined linear axes or linear guides can be used. These extend at an angle relative to one another, preferably 90°, so that the plane of motion of the relevant tool element supported on the cross table, for example, lies perpendicular to the plane that is defined by the direction of transport of the material web or object web, and the width thereof. The tool elements guided by multiple axis drive systems and/or guidance systems can execute arcuate movements. Expediently, these systems are cross tables, for example, arranged in pairs on both sides of the object web, which are able to execute movements both synchronously and asynchronously in relation to the object web. A further preferred embodiment consists in that the multiple axis drive systems and/or guidance systems, for example, cross tables, are connected with their respective longer axes stationary. In this manner, the dynamic stresses occurring as a result of the movement of the other axis and the tool parts supported thereon, and the forces of inertia that are to be overcome, can be minimized. To achieve a coupling element between a functional surface of the object web tool and the cross table or other multiple axis guidance system, according to one optional example of the invention, bars can be provided as support elements or other linear tool supports. Above these, for example, spur needles or even cutting elements or gripping elements can extend, each across the entire width of the material web or object web. In the prior art, these bars are the respective tool supports on the tool-supporting cylinders of the folding unit. Within the framework of the folding system according to the invention, a folding system controller is provided, which controls the movements of all axes interacting in the folding unit simultaneously and comprises an interface with another, higher level controller of an overall system or machine, for example, a higher level printing machine. With the interface, data communications between the folding system controller and the higher level machine controller can be established. The positioning of markings on the object web serves as a guiding variable, for example, wherein these markings can be actual (imprinted) or virtual, i.e., markings implemented through electronic data per software. The term “virtual marking” stems from the context of the virtual guide axis, which is known in the art of modern printing machines and refers to a position marking, which indicates the position of the material web at a specific point in time, and from which, via place-time functions or the associated first three differential quotients (speed, acceleration and slip), the positions of the individual drives are determined. In this case, this marker, which can be conceived of three-dimensionally as a printing mark on the material web, is updated at regular intervals and from this, corrections are calculated, if applicable. Within the framework of an optional embodiment of the invention, the displacement profile of the linear guides and/or linear axes is influenced with a ramped start-up and slow-down for implementing a synchronization with the position and speed of the object web. In this manner, a so-called “chipping” of the object web tools into the material web or object web can be prevented. The web movement variables (web path, web speed, web acceleration and web slip) of the linear axes and linear guides are chosen such that a so-called “flying” positioning of the tools in relation to the material web is enabled, in other words, an asynchronous movement of a tool up to the material web. Once the tool has been engaged with the material web or object web, the tool movement is operated synchronized with the movement of the material web or object web. For the linear axes and cross table axes, servo linear drives are preferably used. However, within the scope of the invention, roller bearings, ball screws, threaded spindles, spindle drives, rack pinion drives, toothed pulley drives, or even pneumatic or hydraulic drives would also be practicable. To prevent an object web tool from colliding with an adjacent object web tool, an optional embodiment comprises a “space-creating” displacement segment. This refers to the displacement of a tool and a tool mount to make way for an adjacent tool. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) Further details, features, advantages and effects, combinations of features and sub-combinations of features on the basis of the invention are provided in the following description of preferred embodiments of the invention and the set of drawings. The drawings show, each from a schematic side view, FIG. 1 the entire folding system comprising a separating device and the folding device downstream thereof, arranged in series; FIG. 2 : an alternative embodiment of the separating device. DETAILED DESCRIPTION OF THE INVENTION According to FIG. 1 , a material web or object web 1 , for example, a web of print substrate, is fed to the folding unit or folding system according to the invention, in a direction of transport A. On both sides of the object web 1 , in the direction of transport A, cutting means 5 , 7 are first disposed, each said cutting means being linearly displaceable back and forth in a transverse direction Q, transversely to the direction of transport A of the object web, with a predefined displacement stroke, by way of a stationarily supported solenoid actuator 2 . The cutting means 5 , 7 comprise a cutting tool support 5 and a cutting blade 7 , which projects outward from said support in the direction of the object web 1 . The cutting means 5 , 7 on both sides are arranged and driven along a linear guide axis y, parallel to the transverse direction Q, so as to be alternatingly brought into cutting engagement with the object web 1 , in order to repeatedly and/or regularly separate sheets or material sections 11 , cut from said web, in a predefined section length (folding format). Additionally, on each of the two sides of the object web 1 or the cut material sections 11 or sheets, a carrier device 4 , 6 is arranged. The carrier device comprises at least one spur needle 6 that projects toward the object web 1 and at least one cutting bar 8 , which is assigned as a counter element to the above-described cutting blade 7 . For this purpose, the cutting bar 8 can be embodied so as to be flexibly pressed in by the tip of the cutting blade. The respective carriers 4 , 6 are displaceable on a two-axis linear drive 2 , 10 , 9 in the manner of a cross table, both along the object web 1 , or cut sheets 11 , or the material sections (linear guide axis x) and perpendicular thereto (linear guide axis y). The two displacement axes x, y are preferably located within a shared plane, according to the cross table principle, and extend perpendicular to one another. The linear guide axis y that extends perpendicular to the object web 1 or to the cut sheet or material section 11 is implemented as the first linear drive by way of a solenoid actuator 2 . Said linear drive uses a predefined stroke to displace the support 4 for the spur needle 6 and the cutting bar 8 such that the spur needle 6 can punch into the object web and can carry the web along in the direction of the linear guide axis x, along the object web 1 or the material section 11 . At the time of actuation of the cutting blade 7 , the cutting bar 8 is available as a pressure pad for the tip of the cutting blade 7 , which, displaced by the solenoid actuators 2 , cuts off the material sections or sheets 11 . To implement the carrier function, the linear guide axis x is used, which extends parallel to the transport direction A, and along which a sliding carriage 10 can be moved back and forth in a controlled manner in a guide base of a linear motor 9 . In this sliding carriage 10 , in turn, the above-described solenoid actuator 2 is mounted so as to be displaceable in a controlled manner for implementing the linear guide axis y, perpendicular to the direction of transport A (parallel to the above-described transverse direction Q). By way of the linear guide axis y, the cutting bar 8 can be brought into the position assigned to the opposite cutting blade 7 and the spur needle 6 can be brought into engagement with the object web 1 or the cut off material section 11 . By way of the linear guide axis x, parallel to the direction of transport A, the spur needle 6 can be actuated so as to transport the cut off material section 11 away from the cutting means 5 , 7 . A roller pair 13 , 14 is positioned downstream of the two-axis linear drives 2 , 10 , 9 on both sides. The cut off material section is guided between the two rollers 13 , 14 , wherein the respective carriers 4 , 6 can be detached from said material section. One of the two rollers is embodied as a nip roller 13 and is preferably driven by a servomotor having a phase angle sensor. The second roller functions as a guide roller 14 and is also linearly displaceable via a correspondingly configured solenoid actuator 3 . The displacement stroke extends in a linear guide axis y perpendicular to the direction of transport A. Thus, the cut material section 11 can be securely gripped in the roller pair and guided. Also disposed downstream of the roller pair 13 , 14 is a light sensor system 15 , for example, a photoelectric sensor. This sensor is configured to detect a leading edge of the cut off sheet or material section 11 and to emit a corresponding output signal to a control system. If this control system links this photoelectric sensor signal with the angular position value that is provided by the angular position sensor of the servo drive of the nip roller 13 , the control system can determine the position of the material section 11 and can influence or readjust said position by adjusting the speed or acceleration, for example. Downstream of the photoelectric sensor system, pneumatic suction and blow elements 16 and 17 are disposed, which hold and guide the material section 11 in a known manner for subsequent folding by means of the folding blade 18 . Said folding blade can in turn be displaced in the transverse direction Q, perpendicular to the direction of transport A, with a predefined displacement stroke by way of a linear drive in the form of a solenoid actuator 2 . The displacement corresponds to the above-described linear guide axis y. The displacement stroke of the folding blade 18 is dimensioned and oriented such that the tip of the folding blade presses the cut off material section 11 between two guide strips 19 in the region of an intended folding line, into the opening of a gripper 20 . Said gripper can be actuated for opening and closing by a gripper actuating drive 21 . The gripper actuating drive 21 is mounted on a sliding carriage 10 , which is mounted in a linear motor 9 so as to be displaceable along the linear guide axis y or transverse direction Q, perpendicular to the direction of transport A. Said linear motor is stationarily mounted. A sheet delivery unit 22 is situated downstream of the gripper 20 . Opening the gripper 20 by way of the actuating drive 21 thereof allows the folded sheet 12 to fall onto the sheet delivery unit 22 and be transported away. Regarding the sequence of movements of the entire system according to FIG. 1 , the following is further stated: According to the position illustrated in FIG. 1 , the cutting means 5 , 7 located to the left of the object web 1 in relation to the direction of transport A and the carrier 4 , 6 located to the right of the object web 1 are each engaged with the object web. Complementarily, with the cutting means 5 , 7 on the right side, the cutting blade support 5 with the cutting blade 7 is retracted to allow sufficient space for the carrier 4 , 6 on the right side. Conversely, the cutting means 5 , 7 on the left side is extended by the relevant solenoid actuator 2 , while the two-axis linear drive 10 , 9 , 2 on the left has moved the carrier 4 , 6 located on the left side away from the cutting site enough that the cutting process by the cutting means 5 , 7 located on the left side will not be disrupted. Once the material section 11 has been cut off of the continuous object web 1 , the cutting means 5 , 7 on the left side will be drawn back out or retracted in the transverse direction Q by the relevant solenoid actuator 2 , while the carrier 4 , 6 that is still engaged with the cut off material section 11 on the right side is moved by means of its allocated two-axis linear drive 9 , 10 , 2 away from the cutting point in the direction of the actual folding station. Thus, the cutting means 5 , 7 on the left side and the carrier 4 , 6 on the right side, and the cutting means 5 , 7 on the right side and the carrier 4 , 6 on the left side are alternatingly engaged with the material to be processed (object web 1 , material section 11 ). In each case, in the push-pull cycle, the two-axis linear drives 10 , 9 , 2 on both sides ensure the opposite phase operation of the allocated carriers 4 , 6 , and the solenoid actuators 2 of the cutting means on both sides ensure the opposite phase extension and retraction of the cutting means 5 , 7 , which are coordinated by a folding control system. During the course of the further transport of the cut material sections 11 through the roller pair 13 , 14 , the material section 11 reaches the region of the folding blade 18 with the allocated gripper 20 , which can be opened and closed. This transport movement can be selectively controlled by way of the nip roller 13 with the guide roller 14 , which is brought into position by the extended solenoid actuator 3 , in functional connection with the photoelectric sensor system 15 , wherein the position of the material sections 11 can be calculated and taken into account in the controller on the basis of the output signals from the photoelectric sensor system 15 and the phase angle sensor integrated into the servo drive of the nip roller 13 . In this manner, when the material section 11 is pressed by the folding blade 18 into the gripper 20 , the guide roller 14 , which up to that point has been thrown on, can be retracted in coordination with this step by means of the correspondingly actuated solenoid actuator 3 , so that sufficient material for producing the folded sheet will be released. The embodiment according to FIG. 2 differs from that of FIG. 1 , for one, in terms of the special embodiment of the cutting blade 7 , in which the shaft of said blade extends across a curved guide shoulder 24 and ends in a pointed cutting edge 23 . For another, the spur needle according to FIG. 1 is replaced by a gripper 26 , which can be opened and closed, and which is embodied for gripping the leading edge of the cut off material section of the object web 1 , which has been curved by means of the cutting edge 23 and the curved guide shoulder 24 of the cutting blade 7 . Here again, a gripper actuating drive 21 is used for opening and closing the gripper 26 , and can be similar to the gripper actuating drive of the gripper 20 assigned to the folding blade according to FIG. 1 . Otherwise, the above statements made in reference to FIG. 1 apply here accordingly. LIST OF REFERENCE SIGNS A Direction of movement of the web of print substrate, direction of transport Q Transverse direction x Linear guide axis y Linear guide axis 1 Web of print substrate 2 Solenoid actuator 3 Solenoid actuator 4 Support for spur needles and cutting bar 5 Support for cutting blade 6 Spur needles 7 Cutting blade 8 Cutting bar 9 Linear motor (LIM with long stator) 10 Sliding carriage 11 Cut sheets 12 Folded sheets 13 Nip roller (servo-driven with phase angle sensor) 14 Guide roller 15 Photoelectric sensor for detecting leading edge of sheet 16 Suction element 17 Blow element 18 Folding blade 19 Guide strip 20 Gripper 21 Gripper actuating drive 22 Sheet delivery unit 23 Cutting edge 24 Guide shoulder 25 Guided web end/guided leading edge of sheet 26 Gripper

A method for producing individual material sections, particularly sheets of paper, according to a certain format, from a web-type, for example imprinted object (object web), more particularly a web of paper or material, using a cutting means for cutting off the individual material sections from the object web and then removing said sections from the cutting means, wherein during the course of actuation of the cutting means at least one carrier is engaged with the object web, wherein following the cutting process, the carrier is displaced, together with the object web gripped by said carrier, by means of a controllable linear drive, over a displacement stroke, which is adjusted and/or varied in a controlled manner by the linear drive according to a section format that is predefined for the material section.

BACKGROUND [0001] A standard “contact” etching process opens holes through a silicon dioxide insulating layer which has been deposited upon a thin silicon nitride layer that covers and protects just-fabricated transistors as part of an active device structure. It is often currently performed in two consecutive, uninterrupted steps in one processing chamber, which is usually a reactive ion etching (RIE) reactor, typically employing parallel plate electrodes through which rf power is passed to create a capacitive discharge. The normal process sequence, for contact etching, involves first rapidly etching holes in a relatively thick silicon dioxide layer, followed by a reduced-power etch of the thin, typically silicon nitride, stop layer. The silicon dioxide dielectric, typically about 4000 Angstroms thick, covering the stop layer must be etched to completion, or very nearly so, though it has a different thickness above the gate region than above source and drain regions. This etching process is typically fast and aggressive to be cost-effective, so the process generally uses energetic ion bombardment provided by the RIE reactor to increase the etch rate and to obtain a desired vertical wall profile. The stop layer (typically about several to five hundred Angstroms thick) etching is usually performed immediately following the main silicon dioxide etching step and takes place while the photoresist still remains on the wafer. Because of the damage this ion bombardment would cause to sensitive junctions and because of the varying thickness of the silicon dioxide layer, the etching process for silicon dioxide is highly selective so that it does not penetrate the thin stop layer. [0002] The stop layer is commonly formed of silicon nitride, but in future implementations, may be formed from other electrical insulator materials, and protects delicate silicide—which comprises the top layer of the junctions in the gate, source and drain regions of transistors—from a relatively aggressive silicon dioxide etching process. The stop layer is so named because the silicon dioxide etching process, which is highly polymerizing, slows down substantially and can be stopped soon after encountering this thin layer of material, so that the stop layer is not penetrated. The stop layer etching step, which generally continues immediately after the silicon dioxide etching step, employs a different gas mixture than the silicon dioxide etching step and typically uses a reduced amount of rf power, often provided to the wafer support pedestal, to reduce the energy of ions. Since the stop layer is typically very thin it can be rapidly and productively removed, even when the etching process has lower power and a much slower etching rate. Lower etching power is beneficial for the silicide since the silicide will be subjected to less energetic ion bombardment thereby causing less damage to the silicide, once the stop layer is penetrated. [0003] Photoresist (PR) stripping is typically performed immediately following the two step etching process, detailed above, that is, following the stop layer etch. The currently used PR stripping (and in some cases residue conversion) process may be performed in one or two parts and is generally performed in a different chamber than the silicon dioxide etching process. [0004] Turning to FIG. 1 , a prior art photoresist stripping system is diagrammatically illustrated and generally indicated by the reference number 100 . Photoresist stripping typically uses the system of FIG. 1 wherein a plasma source 102 is fed gas from a supply 104 through a set of tubes 106 . Reactive species 110 from source 102 are distributed by a baffle system 112 to a processing chamber 114 within which stands a pedestal 116 which supports a wafer 120 . When species 110 from source 102 react with photoresist 122 (shown on only a portion of the wafer surface) to produce volatile reaction products 124 , the latter are pumped away, as indicated by arrows 126 , via ducts 130 . [0005] Downstream stripping processes (such as seen in FIG. 1 ) with wafer temperatures usually above about 200 C, typically using oxygen as principal gas, have been prevalent for all major photoresist removal applications in transistor fabrication as part of IC manufacturing. Oxygen has been the gas of choice since the beginning of plasma based stripping, because atomic oxygen reacts more strongly with organic polymers and carbon than most other radicals. Higher reactivity of species makes stripping rates faster, and faster rates make stripping system productivity higher. Since there are typically twenty or more photoresist removal steps in the IC manufacturing process, high stripping rates, typically several microns per minute, have been valuable in stripping to keep IC costs low for mass-market products. As will be seen below, however, there are concerns at least relating to the use of oxygen with the ongoing advancement of silicon based IC technology. [0006] A conventional stripping and residue removal process, performed following the contact and stop layer etching, generally uses mostly oxygen gas fed to a plasma source, and may use wet chemicals or have a small addition of forming gas or fluorinated gas added in a second step to remove residues. What must be removed is the patterned PR layer, still remaining above the insulator surface along with a substantial amount of polymer residue covering the sides of the hole in the principally silicon dioxide insulator layer as well as the sides of the photoresist mask, and covering the silicide at the bottom of the hole. This polymer residue contains mainly silicon, carbon and fluorine remaining from the silicon dioxide etching. In the commonly used current process, these residues as well as the photoresist need then to be removed while minimizing damage to the silicide. Generally, this process, as performed in reactors such as in FIG. 1 , provides a copious amount of oxygen atoms to the wafer, at elevated wafer temperature (130 C to 250 C) and converts residues to a soft silicon dioxide layer, as well as stripping photoresist. Unfortunately, however, most silicide materials used for junctions, including cobalt silicide and nickel silicide, are sensitive to oxygen and degraded in performance by it. Further, the fluorine, that may be added in the residue removal step following the stripping, also attacks the silicide. Such reactive species as oxygen and fluorine radicals usually cause degradation of more than 10 Angstroms of the thickness of the silicide. In the past, including 130 nm IC technology, there has been sufficient thickness of silicide (or a protective sacrificial silicide used) that the material damaged by stripping and residue removal can afford to be lost without significantly increasing silicide resistance, thereby degrading circuit performance. It is recognized by Applicants, however, that, with very thin NiSi contact layers that are now going into production and will be used at the 65 nm silicon-based semiconductor technology node, the current processes for photoresist stripping and stop layer etching are detrimental to device performance and that there remains a need for improvement. [0007] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. SUMMARY [0008] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. [0009] A method is described as part of an overall technique for fabricating an integrated circuit on a wafer having an active device structure, during which fabrication, a patterned layer of photoresist is formed on an overall insulation layer this is itself supported directly on a stop layer that is, in turn, supported directly on the active device structure for using the patterned layer of photoresist in etching holes through the insulation layer to reach an electrical contact that is defined by the active device structure where each electrical contact of a plurality of the electrical contacts is covered by the stop layer and at least some of the electrical contacts include a silicide material and where a plurality of the holes are etched through the overall insulation layer such that one hole is associated with each electrical contact to at least partially expose the stop layer above each electrical contact and where etching of the holes, at least potentially, produces etch related residues. [0010] In one feature, stripping the patterned layer of photoresist and the related residues is performed by etching using a first plasma that contains oxygen without substantially removing the stop layer such that the stop layer serves to protect the silicide material from the oxygen. After stripping with the first plasma, etching is performed to remove the stop layer from the contacts using a second plasma that is oxygen free, at least to an approximation, and which second plasma contains hydrogen gas. [0011] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. BRIEF DESCRIPTION OF THE DRAWINGS [0012] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be illustrative rather than limiting. [0013] FIG. 1 is a diagrammatic view, in elevation, which illustrates a prior art system for stripping or ashing photoresist and related residues. [0014] FIG. 2 is a diagrammatic view, in elevational cross-section, which illustrates an intermediate step in the processing of a workpiece in which a patterned photoresist layer is present on an insulator that may consist of one or more layers of dielectric materials. [0015] FIG. 3 is a diagrammatic view, in elevational cross-section, which illustrates a contact hole etch including the formation of etch-related residues such that a contact hole is formed terminating within a stop layer. [0016] FIG. 4 is a diagrammatic view, in elevational cross-section, which illustrates stripping of the patterned layer of photoresist and related residues from the contact hole. [0017] FIG. 5 is a diagrammatic view, in elevational cross-section, which illustrates stop layer etching which follows the photoresist strip and residue removal. [0018] FIG. 6 illustrates suitable process conditions for stripping photoresist and residue removal as performed in FIG. 4 . [0019] FIG. 7 illustrates suitable process conditions for stop layer etching as performed in FIG. 5 . [0020] FIG. 8 is a diagrammatic plan view of a system for use in performing the integrated sequence of processing described herein and in which double loadlocks are provided. [0021] FIG. 9 is diagrammatic view, in perspective, of a plasma reactor that is suitable for performing stop layer etching in the system of FIG. 8 . DETAILED DESCRIPTION [0022] 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 described embodiments will be readily apparent to those skilled in the art and the generic principles taught herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein including modifications and equivalents, as defined within the scope of the appended claims. It is noted that the drawings are not to scale and are diagrammatic in nature in a way that is thought to best illustrate features of interest. Descriptive terminology such as, for example, upper/lower and top/bottom has been adopted for purposes of enhancing the reader's understanding, with respect to the various views provided in the figures, and is in no way intended as being limiting. [0023] In the upcoming IC fabrication technology nodes, there will be some changes that will modify process requirements, for example, when using a downstream reactor, as shown in FIG. 1 and described above. For example, the thickness of photoresist layers is decreasing and will likely continue to decrease over the next several years. Deep Ultraviolet PR—currently the advanced resist for semiconductor fabrication at the 130 nanometer node—is normally coated in a thickness of about 600 nanometers or less. Older photoresist types such as g-line and I-line, still used for lower resolution patterning, are typically more than a micron thick. The leading edge photoresist for lithography (193 nanometer radiation) used in 90 nanometer semiconductor fabrication, started in many factories in 2004, will typically be about 400 nanometers thick or less. As critical dimensions shrink, in the next few technology generations, leading edge IC Fabs may use PR with thickness in the range from 200 nanometers to 300 nanometers. Finally, the Extreme Ultraviolet lithography systems, that will be needed in five to ten years from the date of this writing, will likely use resist with thicknesses of only 100 nanometers or a little more. [0024] Due to the decreasing thickness of photoresist masks used for patterning contact holes, PR stripping processes in the future will not need to have such high rates of photoresist removal (about several microns per minute or more) to yield high productivity stripping systems. Since the photoresist layers for advanced lithography will be much thinner than currently used, it may be adequate for stripping processes to have rates on the order of several thousand Angstroms per minute to one micron per minute and still be economically competitive. At first blush, one might assume that reducing the strip rate, and thereby the penetrating nature of the reactive species in the aforedescribed conventional process, might serve to protect a silicide layer. Unfortunately, however, it should be remembered that relatively thinner silicide layers are that much more sensitive to the conventional strip process, as will be further discussed immediately hereinafter. Also, damage to silicide is self-limiting in depth and most occurs in the first 10 to 20 seconds of the process. [0025] Other changes, beyond the subject of photoresist, are also likely to take place. For example, it is expected that the high conductivity material under the silicon nitride stop layer, but covering the junction—the electrical contact material—will be changing over the coming generations of semiconductor technology from cobalt silicide to nickel silicide for the 90 nm generation and possibly nickel-platinum silicide in the 65 nm or 45 nm generations of devices and getting much thinner. Whereas in the past and currently (130 nm to 90 nm IC technologies), for the source and drain regions of transistors, moderate loss, damage or oxidation of silicide has been acceptable, in future generations of semiconductor manufacturing technology, it is likely to be necessary to avoid too much loss of or damage to silicide at the exposed surfaces of the junction to maintain low contact resistance. Thicknesses of the silicide used in these areas, previously closer to 300 Angstroms or more, will soon be on the order of 200 Angstroms, and decreasing toward 100 Angstroms and, thus, loss of material or degradation of its electrical properties such as conductivity are less and less acceptable, particularly in view of the decreasing layer thickness. [0026] Still considering the advanced use of silicide layers, it is further recognized that care should be taken to preserve the desired electrical properties of the silicide layer during a number of process steps. In this regard, future generations of integrated circuits, having a critical dimension of less than about 90 nanometers, will likely be increasingly dependent on protecting the silicide layers that serve as electrical connection points or junctions for the transistors being fabricated. As one example, the silicide should be protected during removal of a stop layer that directly overlies the silicide. As still another example, the silicide should be protected during photoresist stripping. It is submitted that conventional approaches for protecting the silicide layer impose limitations on the further advance of technology. Accordingly, improvements are needed, as will be further discussed below. [0027] Applicants have found that, in conventional processing which removes the stop layer after the contact hole etch, but before photoresist removal, oxygen based stripping and cleaning causes significant damage to the NiSi, which is exposed at the bottom of the just-etched contact holes. In particular, Applicants recently completed experiments, with such exposed silicide, demonstrate that the sheet resistance of a 200 Angstrom thick NiSi layer is increased by about 10% to 15% by the action of a 30 second, conventional downstream stripping process using oxygen, even when that process is performed at the lower end of the range of temperatures (<200 degrees C.) normally used for photoresist stripping. This was also confirmed on a stripper using a different type of plasma source. [0028] When Applicants exposed a silicide supporting wafer at 250 degrees Celsius to oxygen-based downstream stripping, the process was found to cause a 12% to 15% increase in the sheet resistance of the nickel silicide. Lowering the temperature to 200 degrees Celsius only slightly mitigated the damage, resulting in about a 10% increase in sheet resistance. While not intending to be bound by theory, the damage mechanism that increases sheet resistance of the NiSi probably involves the oxidation of the nickel silicide to silicon oxide and nickel. Such exposure decreases the electrical conductivity of the affected material and thereby reduces the speed of an IC sufficiently to lower the economic value of the IC. With this result in hand, it is submitted that new, even thinner junctions using Nickel Silicide will suffer substantially increased electrical resistance with even a modest amount of chemical damage such as oxidation of the silicide during such a photoresist strip, which follows a stop layer etching process. Therefore, Applicants recognize that there is an advantage in avoiding direct exposure of silicide to any oxygen-based dry stripping process. [0029] Based on the foregoing, one way to avoid the damaging effects of oxygen-based stripping might be to use a gas feed to the plasma stripping source excluding oxygen. One alternative to oxygen-based feed gases for stripping is hydrogen. Applicants have found an increase in NiSi sheet resistance following direct exposure of the silicide to the hydrogen-based stripping process to be as low as 2% . This is much less than the roughly 10% minimal increase that was found when using oxygen-based gas mixtures. Unfortunately, however, Applicants have also discovered that residue removal with gas mixtures containing predominantly hydrogen, but effectively no oxygen, is limited as compared to what is achieved using mixtures based on oxygen. For example, purely downstream residue removal processes using hydrogen/nitrogen based process chemistries have been found recently by Applicants to need improvement with respect to removal of carbon polymer from the sides and bottom of just-etched contact holes. Such carbon polymer should be removed essentially completely for the electrical resistance of the connection to the transistor at the contact to be optimal. Thus, replacement of prior art oxygen-based process with a hydrogen-based process is not entirely adequate since there appear to be competing factors at least with respect to the removal of residue and protection of silicide properties when hydrogen-based and oxygen-based processes are compared. [0030] In summary, while dry photoresist stripping processes using hydrogen gas rather than oxygen, following stop layer removal, produce substantially less damage to the nickel silicide than conventional oxygen-based stripping processes, in a downstream type of stripping reactor, such a hydrogen-based process is less than optimal as a mass production-worthy solution to the degradation of NiSi junctions by oxygen-based stripping in the conventional process sequence. [0031] Applicants have found a new strip/stop layer etch integrated process that is less damaging to the silicide and more cost effective. This process is performed in a single system with photoresist strip and etching steps in a reverse order. That is, the photoresist stripping and residue removal is performed while the stop layer is intact, thereby protecting the silicide. Only after photoresist stripping is complete does the stop layer etching follow. Since the delicate silicide is protected by the stop layer, there is freedom to choose the stripping chemistry to be substantially oxygen or hydrogen-based and/or to include ion bombardment. Further, there is an option to add reasonable amounts of fluorine containing gas to either oxygen-based or hydrogen-based stripping gas mixture, in order to remove any silicon-based veils or structures that form from post-etch sidewall residues. Damage to the silicide is no longer a concern since the silicide is protected. [0032] Referring to FIG. 2 , a workpiece is diagrammatically illustrated in a partial, cross-sectional view and generally indicated by the reference number 200 . A substrate 202 supports a gate dielectric 204 in a gate region. The substrate can comprise, for example, a wafer such as a silicon wafer. A gate electrode 206 , that may be a metal or polysilicon or a silicide, is formed on gate dielectric 204 . A stop layer 208 overlies gate electrode 206 . Substrate 202 further includes a junction 210 formed therein. This junction, for example, can be a drain or source region of the device that is being produced. Junction 210 , like gate electrode 206 , is formed using a silicide material. Stop layer 208 also overlies junction 210 . The foregoing structure, formed on substrate 202 supports a thick layer 212 of electrically insulative material which, in the present example, is silicon dioxide (SiO 2 ) and may be a compound layer, having an antireflective layer upon the SiO 2 . Insulating layer 212 supports a patterned layer of photoresist 220 that is patterned to include a first aperture 222 that is generally aligned with gate electrode 206 and a second aperture 224 that is positioned above junction 210 . The structure below and including gate electrode 206 and junction 210 may be referred to as an active device structure. [0033] Attention is now directed to FIG. 3 which diagrammatically illustrates the appearance of workpiece 200 including etching contact openings or holes 242 and 244 through photoresist apertures 222 and 224 using a plasma 246 . The contact holes are formed in insulating layer 212 such that stop layer 208 is exposed at the bottom of the contact holes. During the contact etch, polymer residues 250 , which can contain carbon, can be formed in contact holes 242 and 244 . These residues may extend across the bottom, vertically along the sidewalls of the contact holes, and on the inner surface of the photoresist. During conventional oxygen-based stripping this may form what is generally referred to as a veil. [0034] Referring to FIG. 4 , removal of photoresist 220 , from workpiece 200 , is illustrated. With the silicide of contact 206 and junction 210 protected by stop layer 208 , at least a portion of photoresist stripping, whether oxygen-based or otherwise, may be performed using an ion bombardment based process which exposes the structure to ions 262 , for relatively quick removal of even tough carbon-based polymer residues 250 from the bottom of the contact hole. It is noted that such polymers are generally formed by the contact hole etch. This anisotropic stripping process may be performed at low wafer temperature, regardless of whether oxygen or hydrogen-based gases or mixtures are used. Acceptable productivity for future IC production at the 65 nm node and below is achieved at least for the reason that the photoresist will be much thinner than in previous IC technology generations. The ability of energetic and anisotropic ions to reach to the bottom of the just-etched contact holes assures that reactive species 262 can remove carbon from the polymer residues even near the bottom and at the edges proximate to the bottom of the contact hole. Once stripping and residue removal has been completed, upper surfaces of insulating layer 212 are exposed, along with stop layer 208 . [0035] Attention is now directed to FIG. 5 , which illustrates a stop layer etch step that follows photoresist and residue removal, as described above. For purposes of performing the stop layer etch, a plasma 270 is used in one or more etching steps. In order to make the process sequence under discussion attractive in terms of process throughput and to achieve a high production yield, there are several aspects of the stop layer etching process that should be considered, which conventional processes and systems have not addressed. For example, with respect to this new sequence (where photoresist is removed prior to the stop layer), the photoresist mask no longer protects the upper layer of insulating, dielectric material 212 . This insulating material may be silicon dioxide or any covering dielectric (typically, anti-reflective coating) layer. In this case, the edge of the contact hole in the dielectric, or any coating layer on top of the dielectric, is exposed to the same etching as the stop layer. This may cause a loss of material from the dielectric or covering layer and allows etching of exposed edges of dielectric materials that can produce faceting or rounding of that edge, thus increasing the effective diameter of the hole in the dielectric. [0036] As will be seen, embodiments that are effective in removing the stop layer are characterized by a soft, but effective etching process so as to substantially limit damage to the delicate silicide in regions 272 (indicated using dashed lines in FIG. 5 ), as well as minimizing removal of, faceting or rounding of the edge of exposed dielectric 212 . Such stop layer etching also permits the use of a relatively aggressive photoresist stripping and residue cleaning process, with the stop layer in place to protect the silicide. It has been found that this combined process allows an integrated circuit to exhibit reduced or low electrical contact resistance so as to improve transistor speeds for the upcoming 65 nm and 45 nm IC technology generations and beyond. [0037] Etching processes activated by energetic ions, including oxygen or nitrogen, which sputter or damage material at the wafer surface, will increase contact sheet resistance due to loss of or damage to the silicide. Processes where there is ion bombardment, along with exposure to radicals of reactive species such as fluorine, will etch silicon and may also chemically damage the silicide to a depth that is a substantial fraction of the total thickness. Regardless of the mechanism, loss of even 10 Angstroms of such silicide results in the increase in sheet resistance for a 200 Angstrom thick silicide of about 5%, which can slow the transistor by about 5%. Applicants have found from measurements that the stop layer etching process disclosed herein is less damaging to the silicide, resulting in a smaller sheet resistance increase in NiSi than caused by conventional fluorocarbon-based stop layer etching processes which typically cause a greater than 10% increase in sheet resistance of the silicide. While not intending to be bound by theory, it is thought that the improvement in contact sheet resistance arises from reduced ion damage to the silicide. Further benefit is afforded by the presence of the stop layer during the photoresist strip. [0038] The integration sequence (IS) of steps for the process that is the subject of the present disclosure generally is performed subsequent to the contact hole etch and includes (1) first stripping photoresist which may additionally remove some or all residues from the etching process, (2) removing remaining residues on the inside surface of the etched hole in both dielectric and PR followed by (3) etching through the stop layer which may include cleaning of the silicide surface. There may also be a separate fourth step, subsequent to the stop layer etch, in which the silicide surface exposed beneath the stop layer can be cleaned of remaining fluorine or carbon. This step may use pure hydrogen or hydrogen mixed with inert gas or gases. This IS, an alternative to the usual sequence, avoids damage to the silicide material of the junctions by removing photoresist and residues while the stop layer is still intact to protect the sensitive silicide at the junctions from chemical damage resulting from a stripping process. It is believed that this integration sequence has not been used heretofore for at least two principal reasons. First, since an adequately selective and gentle stop layer etching process was not known, it was believed that any stop layer etching process would consume too much of the exposed layers, and enlarge unacceptably the “contact” holes made in the contact hole etching step. Second, since the new IS would involve excessive chamber-to-chamber substrate transfers, system throughput would suffer, based on inefficient use of the etching chambers in an expensive etching system. That is, it would be necessary to process wafers in an etching chamber, then in a stripping chamber and finally again in the etching chamber. Although some etchers do have integrated stripping stations, even these systems are not able to efficiently process wafers in this new and advantageous sequence. [0039] With respect to the stripping/residue removal procedure and stop layer etch procedure described herein, it should be appreciated that either procedure may be multi-step, and may have different gas compositions, gas pressures, wafer temperatures and plasma source configuration for each step. Different steps in the same procedure may be performed in different chambers. Some of the process steps may use hydrogen as exclusive or a main source of reactive gas. Through the use of these procedures damage to or loss of silicides such as, for example, Nickel Silicide or other exposed silicide, used to make contact to the source, drain and gate of each transistor, can be substantially reduced. [0040] The handling and process control system used with the wafer processing chamber(s) can use separate load lock and wafer transfer chambers so as to greatly reduce the stirring up of very small particulates during the venting and pumping cycles needed to bring wafers into the evacuated process chamber. Such a two-stage handling system also reduces the risk of leakage of hydrogen into the atmosphere within the factory, reducing the risks of fire or explosion. The plasma reactor, that may be used for stripping and residue conversion as well as stop layer etching, may be an inductively coupled one having a grounded electrostatic shield between a plasma excitation coil and the reactor's dielectric vacuum wall. A parallel plate reactor can be used, having excitation power to one or both electrodes. Such a reactor may well control the ion energies in the stop layer etching process and thereby minimize rounding and widening of holes for electrical connections to the transistors, as it reduces damage to and etching of the delicate silicide. Stripping and Residue Removal/Conversion [0041] Turning now to FIG. 6 , attention is now directed to a number of appropriate and exemplary embodiments of photoresist removal recipes that are set forth by this figure. Stripping with the described gas recipes may be accomplished in an automated PR stripping system that may use an rf discharge plasma as a source for generating reactive species from injected gas. The stripping and/or residue conversion step(s) may use ion bombardment or high wafer temperature to promote the stripping or removal reactions in any or all steps, although this is not required. The wafer or workpiece may be either remote from the plasma source for a stripping step or may be adjacent to the plasma source. Plasma generation may be accomplished using any of the well-known types of plasma sources such as, for example, microwave, inductively coupled or capacitively coupled sources. Particular care need not be taken in this step to control or limit the ion energy to very low values, although energies above a few hundred eV might produce faceting of the edge of the contact hole, previously made by the dielectric etching process. Generally, if the wafer is proximate to the plasma source, then either high or low temperature may be used, but if the wafer is remote from the plasma, the temperature generally may be above 100 degrees Celsius. [0042] Still referring to FIG. 6 , the disclosed stripping and residue removal/conversion process may be accomplished over a wide range of gas pressures, extending from about 2 mTorr to as much as about 5 Torr. Generally, the lower pressures between about 2 mTorr and a few hundred mTorr may be more appropriate for the ion-activated process whereas the higher pressures may be used for either ion or thermally activated processing. The power provided to the plasma reactor may generally vary between about 100 Watts to as much as about 5 kilowatts. Wafer temperature may be from room temperature up to about 350 degrees Celsius. The total flow of gas provided for the process may vary from about 50 standard cubic centimeters per minute to as much as about 20 thousand standard cubic centimeters per minute, i.e., 20 standard liters per minute (SLPM), the range depending on the pressure for the process step. Typically, processing at low pressures, generally less than about 200 mTorr can be performed with total process gas flow less than or about 2 standard liters per minute. Some step(s) in stripping resist or removing residues may also use ion bombardment of energetic ions to promote chemical reactions for stripping or residue conversion. Power provided to energize ions, in the event that ion bombardment is to be used, may vary between about 10 Watts to as much as about 1000 Watts for 300 mm size wafers, depending on the gas pressure and the amount of power used to generate the plasma. Higher bias power levels (above several hundred Watts for a 300 mm wafer) above about 0.5 Watts per Centimeter Squared of wafer area are generally more appropriate for higher gas pressures, typically above about 1 Torr. Gas Chemistry for Stripping and Residue Removal/Conversion [0043] With continuing reference to FIG. 6 , specific gas mixtures and process conditions for removing PR and converting or removing residues for each of these purposes are described. Stripping and residue removal steps in this process are not significantly damaging to the delicate silicide based on the new integration sequence in which PR and residues are removed prior to etching of the stop layer. While stripping and residue removal are accomplished first, with the stop layer intact, some embodiments may use hydrogen gas as the major reactive gas for both stripping and residue conversion or removal. Using little or no oxygen in stripping has the potential advantage of minimizing residual oxygen at the point when the stop layer etching exposes the silicide. Fluorine containing gases in modest amounts (up to about 5% fluorine) may be added to the hydrogen to accelerate the PR ashing and to aid in the removal/conversion of residues. Higher amounts will cause some degree of stop layer etching as the residue is being removed. In other embodiments, nitrogen or nitrogen containing gases may be added in at more than 50%, even contemplating the use of forming gas, such that nitrogen can be the principal gas. Other embodiments may use added oxygen to improve stripping rate in this IS and may use oxygen as the principal gas. Generally with regard to the gas chemistry during the stripping step, it should be appreciated that a considerable range of flexibility is provided as a result of the protection that is afforded by performing photoresist stripping with the stop layer in place. One two-step process embodiment, shown in FIG. 6 , as Specific Process 1 , uses hydrogen gas with about 10% nitrogen addition to strip resist, and hydrogen with about 2% fluorinated gas (CF 4 or other fluorocarbon) added after end point to hydrogen to remove residues. Helium may be added to the gas mixture if desired whether ion bombardment is used or not. A Particular Embodiment of Photoresist Removal and Residue Conversion [0044] Still referring to FIG. 6 , one embodiment of the disclosed process is designated as Specific Process 2 , in which stripping and residue removal are performed using an electrostatically shielded inductive plasma reactor. The processing chamber includes an electrostatically shielded inductively coupled plasma source with a separately powered rf bias applied to the wafer holding pedestal. As one having ordinary skill in the art will appreciate, the pedestal temperature and the wafer temperature are generally independent of one another, while the use of an electrostatic chuck, for purposes of holding the wafer, causes the wafer temperature to at least generally track the pedestal temperature. The stripping and residue conversion step is performed first at a low pressure, between about 5 mTorr and 20 mTorr. Mainly oxygen is used for this step, where up to about 5 percent by flow rate of CF 4 may be added for the last 20% of the stripping process time to chemically break down silicon containing residues. Hydrogen may be added for purposes of residue removal, for example, serving to remove veils. A further purpose for presence of hydrogen resides in enabling a smooth transition to a stop layer etch in which oxygen is not used or is significantly reduced to the point of affecting maintaining the plasma. In this latter case, the hydrogen flow can be provided in order to avoid extinguishing the plasma as the oxygen flow is diminished and/or eliminated for purposes of the subsequent stop layer etch. It also allows hydrogen flow to be increased to levels needed for the following process step, the stop etch, without causing a burst of gas which could cause undesirable process effects or even plasma extinguishing. In making this transition, temperature compatibility between the photoresist stripping step and the stop layer etch step can also be considered. For example, if an at least relatively low temperature contact layer etch is to be performed, it may serve as an expedient, saving total process time, in the transition to use a relatively low temperature photoresist strip. The total gas flow may range from about 50 Sccm to as much as about 2000 Sccm. The power provided to the plasma source may be from about 200 Watts to about 2000 Watts with bias power from about 0.3 Watts per centimeter squared to about 1 Watt per centimeter squared. Typical processing is performed on either 200 mm or 300 mm diameter silicon wafers. The total time for this step depends on the photoresist thickness, but is typically about 30 seconds for photoresist of about 3000 Angstroms thickness, including time for over-etching, to ensure complete removal. Stop Layer Etching Step [0045] In the context of the disclosed sequence with stop layer removal subsequent to photoresist stripping, a number of aspects for appropriate stop layer etching will now be described. First, to be successful, the stop layer etching process should avoid removing too much of the main silicon dioxide dielectric (item 212 in FIG. 5 ), or any dielectric (anti-reflective coating or otherwise) layer that covers the silicon dioxide that is left exposed after photoresist stripping. It should be appreciated that this differentiation is somewhat difficult, depending upon the materials. For example, such difficulty is encountered when the DARC layer (Dielectric Antireflective Coating) 212 is silicon oxynitride and stop layer 208 ( FIG. 5 ) is silicon nitride. These are quite similar materials, which makes for a challenge in etching the silicon nitride at a much higher rate than the silicon oxynitride. Typical selectivities of conventional processes for silicon nitride etching, relative to silicon oxynitride, are very low—typically about 1.5 to 1.0. Such a poor selectivity would result in too much loss of silicon oxynitride, and thus is not considered by Applicants as acceptable for present purposes. Second, the stop layer etching process should avoid any substantial rounding or faceting of the edges of the contact hole, since this effectively increases the maximum diameter of the metal connection to the transistor and may cause shorting from one connection to an adjacent connection. Third, the stop layer etching process should not affect the diameter of the contact hole, below the surface or the sidewall angle of that hole. Fourth, the stop layer etching process should not cause undercutting of the silicon dioxide layer due to isotropic etching of the silicon nitride, especially following endpoint of this etching step, which would make it any wider at the base of the contact hole than above. Fifth, the stop layer etching process should cause little or no damage to the nickel silicide, once the stop layer has been penetrated in any location. Since the stop layer will inevitably be removed in some area(s) on the wafer before some other areas, it is desired that “over-etching” during what may be termed as an “over-etch period” does not excessively damage the delicate silicide in these areas, where early and complete removal of the stop layer is initially achieved. This process step has high selectivity of Si 3 N 4 etching relative to NiSi or other silicides. In conjunction with this latter aspect, it is desired that the stop layer etching process be very uniform in its rate across the wafer. Further, for areas of initial removal of the stop layer, the etching process may use low or minimum ion energies to limit excessive ion penetration and damage of the silicide during the over-etch period. Gas Composition for Stop Layer Etch [0046] Referring to FIG. 7 , in meeting the desired process aspects set forth immediately above, Applicants have discovered a number of embodiments wherein the etching of the stop layer is accomplished using a hydrogen-based gas mixture, including a fluorinated gas such as, for example, CF 4 or other fluorinated hydrocarbons, such as C 2 F 6 , CHF 3 , and/or other fluorine containing gases such as NF 3 or SF 6 , at least during an early part of the etching. Such process may use small amounts (up to approximately 10%) of oxygen in its early part, but should exclude oxygen in the later portion of stop layer etching—certainly prior to penetration of the stop layer in any location. Stop layer etching for this IS, in which photoresist stripping is performed prior to stop layer etching, may advantageously use ion bombardment to anisotropically remove the exposed stop layer. Lacking such ion activity, it is likely that for some stop layer etching processes there might be isotropic etching of the material at the sidewall of the contact hole that would cause the dimensions of the hole to increase and affect the device yield. It is extremely likely that such process would continue to etch the stop layer under the main dielectric, thus causing widening of the holes at the base and leaving voids after electrical connections are made to the junctions. In some embodiments, stop layer etching may be completed with substantially pure hydrogen or a mixture with helium to minimize sputtering of the silicide junction material as well as to scavenge fluorine from the bottom or sides of the hole. In most cases, it is acceptable to add some inert gases, especially helium, which in some cases, may be in even greater flow rates than the hydrogen. One may also add small amounts of nitrogen (up to about 10%) to the hydrogen to improve scavenging of the remaining carbon in the contact hole. [0047] As illustrated by Specific Processes 1 and 2 in FIG. 7 , during the early and main part of the stop layer etching process, up to about 20 percent or less of fluorine containing gas (as a percentage of the hydrogen flow) may be part of the gas mixture. In the later stages of stop layer removal, the fluorine may be stopped and the hydrogen gas (possibly diluted with helium or having a small amount of nitrogen) used proximate to completion of etching of the stop layer. This should minimize damage to the silicide, while removing fluorine and small amounts of carbon remaining from the etching process from the sidewalls and bottom of the contact hole. In particular, fluorine may be removed from the surface of the silicide which helps preserve its effective thickness and high electrical conductivity. [0048] Referring to Specific Process 3 , in FIG. 7 , one embodiment of the stop layer etching process uses predominantly hydrogen gas, with a small flow of added fluorocarbon gas, fed to an inductively coupled plasma reactor with separate power supply for a plasma source and biasing of the pedestal. The gas pressure in the reactor is less than in the typical RIE reactor, under about 30 mTorr with injected gas being mainly hydrogen with less than about 15% added CF 4 . Only modest rf power, less than or about 300 Watts is provided to the plasma source and in the range from approximately 0.1 W/cm 2 to approximately 0.4 W/cm 2 to the wafer holding pedestal. It should be appreciated that this stop layer etching follows what may have been a very aggressive ion-based photoresist stripping process, performed in an equivalent or in the same reactor, using substantially more rf power, both for the plasma source and for wafer bias, to rapidly and completely remove the photoresist and any carbon in the post-etch polymer. Other Characteristics of the Stop Layer Etching Step [0049] Stop layer etching may be performed in the same chamber as the preceding photoresist stripping step, or in a different chamber. Embodiments using the new IS may be performed at elevated temperatures such as above 100 Celsius, but the etching of the stop layer can use ion bombardment to provide activation energy and can take place with wafer (or pedestal) temperature generally below or about 100 degrees Celsius. The process step for stop layer removal should be performed with the plasma of the source adjacent to the wafer. This plasma source may be inductively coupled and, in some embodiments, the source will have an electrostatic shield to prevent undesirable elevation of the plasma potential, due to capacitive coupling from induction coil to the plasma. The plasma source generally produces the needed ions as well as the neutral radicals to react with and volatize the Si from the SiN or other stop layer material, and to do so deep within the contact hole made in a previous step. To make the stop layer etching process anisotropic, it is usually necessary to have rf bias applied to the wafer holding pedestal. This bias power, when used in combination with an inductive plasma source, effectively adds energy that mainly provides added energy for ions that bombard the wafer. Bias power may be provided from the same source that generates the plasma and/or a separate source to increase energy of ions bombarding the wafer so that ion bombardment energies can be at or above about 20 eV and may in some embodiments be less than about 100 eV. [0050] If there is no separately powered plasma source, inductive or microwave based or otherwise, and the etching is performed with a capacitive discharge then single or multiple sources of rf power may be used. In particular, in cases where electrodes have an inter-electrode gap that is small compared with the wafer radius it may be possible to apply different frequencies of rf power to both the pedestal and to the counter-electrode, which is normally a showerhead for gas introduction. In some embodiments, a higher frequency of rf power (>20 MHz) is applied to the showerhead to generate a plasma while one or more lower frequency sources of power are connected to the pedestal to provide energy to ions bombarding the wafer. [0051] Whether applied as a separate bias power for an inductive plasma source, or for a capacitive discharge that is powered from the wafer-holding pedestal, typically, rf power in an amount between 0.1 Watts/centimeter squared and about 1 Watt/centimeter squared may be used. In the event that a narrow gap, capacitive rf discharge is used, where rf power is applied to the counter-electrode and not the wafer-holding pedestal, the amount of power to the counter electrode may generally be approximately equal to 0.1 to 1.0 Watts/cm 2 . The power level to the pedestal, in any case, may be reduced by up to about 70% for the latter part of the stop-layer etching step to correspondingly reduce the energy of ions bombarding the silicide. [0052] The gas pressure may be in the range from approximately 1 to 2 mTorr to as much as about 1 Torr. The total gas flow is, at least to a degree, usually dependent on the pressure of operation. Typically, pressures above approximately 300 mTorr may use total gas flow of between approximately 500 standard cubic centimeters per minute (Sccm) and about 5 standard liters per minute. Pressures below approximately 200 mTorr generally use less gas—typically a total gas flow from about 20 standard cubic centimeters per minute to about 2 standard liters per minute. A Particular Embodiment of the Stop Layer Etching Step [0053] In one embodiment of the stop layer etching step, which is illustrated as Specific Process 4 in FIG. 7 , mainly hydrogen is used as feed gas to which a Fluorine containing gas such as CF 4 (at about 7% to 15% of the total gas flow) is added. The gas pressure for the stop layer etching process can range from about 5 milliTorr to as much as about 20 milliTorr. There is rf power provided to the plasma source and a separate source of rf power to the pedestal supporting the wafer. The power supplied to the pedestal is modest, being between about 0.2 Watts per square centimeter of the wafer surface and about 0.4 Watts per square centimeter of wafer or pedestal surface that results in a low dc bias voltage. The time interval for etching depends on the thickness of the silicon nitride stop layer, but is typically between about 20 seconds and 45 seconds for a 400 Angstrom thick layer. It is of value in controlling the process that the potential of the plasma in the source be kept low so that the ion energies can be reduced to levels less than or about 50 eV such that damage to the silicide is minimal. This is accomplished, in one embodiment, by using an electrostatically shielded inductively coupled plasma source which is very efficient at producing ions and neutral radicals providing for a high etching rate with low ion energies. Excessive ion energies may cause unacceptable damage to the silicide layer, following penetration, and aggravate rounding of the edges of the contact hole, previously formed using a photoresist mask. [0054] Applicants have found that the processing conditions immediately above result in an etching process with a surprisingly high “selectivity” ratio of etching rates of over 3 to 1 for silicon nitride relative to silicon oxynitride. The etching rate of the process for the silicon nitride ranges from about 900 Angstroms per minute to about 1200 Angstroms per minute, yet there is very little rounding or faceting (between about 60-120 Angstroms) of the corners of the contact hole. Further, the process completely cleared carbon residues in the contact hole, at least from a practical standpoint, and even with prolonged exposure did not excessively degrade the electrical conductivity of the NiSi layer. Wafer Handling and Plasma Reactor Apparatus For Integrated Strip/Residue Removal and Stop Etch Processes [0055] In one embodiment of the stripping and etching system, a high-throughput type of handling and vacuum system is employed with stripping/etching chambers having an inductively coupled plasma source. Such a system can employ separate load lock and wafer handling chambers that can safely handle substantial flows of hydrogen gas, and permits low levels of particulate contamination, such that the process meets all requirements for mass production. Further, each process chamber may utilize inductively coupled plasma source(s) wherein an electrostatic shield assures that the plasma potential is well controlled. [0056] In general, a plasma reactor chamber(s) consisting of plasma source plus wafer process station are part(s) of an automated PR stripping system including a robotic wafer handling system. In some cases, current wafer handling systems for stripping chambers may use a single stage vacuum load lock for wafers prior to inserting them into the vacuum chamber used for stripping. Non-loadlocked systems often release any remaining hydrogen gas in the process chamber into the environment and therefore they should not be used for stripping or etching processes employing large flows of hydrogen gas. Single load-lock systems make processing with substantial amounts of hydrogen gas somewhat safer, since they generally prevent hydrogen leakage to a degree that may lead to accumulation at atmospheric pressure that produces an explosion. However, even with these precautions, there can still be release of small amounts of hydrogen from such a system, because the loadlock alternately cycles to and from atmospheric pressure. Such hydrogen could possibly accumulate in any pockets in the ceiling of the factory with potentially dangerous consequences. [0057] Turning to FIG. 8 , one embodiment of a suitable wafer processing apparatus, for the IS addressed herein, is diagrammatically shown and is generally indicated by the reference number 300 . System 300 may employ a wafer handling system with separate load-lock and wafer transfer chambers because it permits gas mixtures high in hydrogen gas to be reasonably safe. It further helps to reduce the stirring up of particulate that may be present in the wafer transfer chamber which often causes particulates to end up on the wafer. In such a stripping system, wafers are supplied for processing and returned from processing in cassettes or FOUPS 306 (the current term in IC manufacture for a closed pod that holds wafers) placed on load ports. The wafers from the cassettes/FOUPS are moved by an automated handling robot 310 into a first load lock 312 which can hold two wafers or more. The first load lock is evacuated and the door to a second load lock 314 is then opened. From first load lock 312 , a wafer is brought into second load-locked chamber 314 by a vacuum robot 316 . A door (not shown) to a processing chamber 320 is opened to remove a previously processed wafer and permit loading of a new wafer. The wafer to be processed is then moved into a processing chamber 320 , after which the door is closed and the wafer is processed. The completed wafer is then removed from the processing chamber and returned to second load-lock 314 by vacuum robot 316 and placed into first load lock 312 , under vacuum. First load lock 312 is then re-pressurized to atmospheric pressure and all wafers therein removed from the first load lock by an atmospheric robot 324 . It is noted that this latter robot can moved wafers laterally, as shown in phantom. Processed wafers are then replaced into cassettes/FOUPS 306 from which they are ready to move to the next production step. It is noted that the wafer transfer chamber is always at vacuum. Furthermore, it may be operated so that it is open only to the process chamber when wafers are being loaded or unloaded into the process chamber. [0058] In performing the stop layer etching process, it may be advantageous to do so with a plasma reactor that controls and minimizes the rf and/or dc potentials of the plasma in the reactor. This may benefit the process, since it results in lower and independently controllable energies for the ions bombarding the silicide when the etching process completes. Such lower energy ions may then do less damage to the silicide and may allow etching processes resulting in less increase in the sheet resistance of the silicide. Conventional parallel plate capacitive discharge-based etching reactors—in particular those with rf power frequencies of 13.56 MHz and below—may not have such low plasma potentials and truly independent control of the ion energy and ion density. Parallel plate capacitive discharge etching reactors with dual rf or uhf frequency power applied to the electrode(s), where one of the frequencies is at or above about 40 MHz while another is less than or equal to about 13.56 MHz, may satisfy the requirements for such control and minimization of ion energy. Inductively coupled plasma etching or stripping reactors with or without electrostatic shielding between excitation coil and dielectric window or plasma vessel may also be used in some embodiments of the disclosed system. Such a reactor can provide some degree of independent control of ion energy and density, and make possible low plasma potential and low ion energies. [0059] With reference to FIG. 9 , one suitable reactor for use in performing stop layer etching, as described above, is diagrammatically illustrated in a perspective view and generally indicated by the reference number 400 . It is noted that two such configurations can be used in processing chamber 320 of FIG. 9 , as indicated by the reference numbers 400 a and 400 b . A wafer 402 is supported on a pedestal 404 to which is connected an rf power supply 406 and in this case also a matching network 408 which may provide a variable and well controlled amount of rf power to the pedestal. A plasma 409 is generated in this embodiment of the plasma reactor by an induction coil 410 (diagrammatically indicated by a series of dots) to which a separate source of rf energy 412 is provided—in this case through a matching network 414 . When power is provided to coil 410 , the rf energy passes through an electrostatic shield 416 and through a window or dielectric vessel 418 into the plasma. The plasma thus generated is a source of ionized gas species and fragments of molecular feed-gas species, some of which are especially chemically reactive radicals. [0060] Although each of the aforedescribed physical embodiments have been illustrated with various components having particular respective orientations, it should be understood that the present invention may take on a variety of specific configurations with the various components being located in a wide variety of positions and mutual orientations. Furthermore, the methods described herein may be modified in an unlimited number of ways, for example, by reordering, modifying and recombining the various steps. Accordingly, while a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.

In device fabrication, a photoresist layer is formed on an insulation layer, above a stop layer that is supported directly on an active device structure. Holes are needed through the insulation layer to reach a contact arrangement, defined by the active device structure in which each contact is covered by the stop layer and some of the contacts include a silicide material. A plurality of contact openings are etched through the insulation layer to expose the stop layer above each contact, which may produce etch related residue. The photoresist and residues are then stripped using a first plasma that contains oxygen, without removing the stop layer such that the stop layer protects the silicide material from the oxygen. Thereafter, etching is performed to remove the stop layer from the contacts using a second plasma that is oxygen free and which contains hydrogen.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Cross reference is made to: [0002] U.S. patent application Ser. No. 12/050,575, filed Mar. 18, 2008, entitled, “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-3); U.S. patent application Ser. No. 12/050,605, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-4); [0003] U.S. patent application Ser. No. 12/050,634, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-5); and [0004] U.S. patent application Ser. No. 12/050,677, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” (Atty. Docket No.: 4366BKD-7), all of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION [0005] The invention relates generally to set-top boxes and more particularly to one or more profiles associated with a set-top box. Additional aspects of the invention relate to the interoperability of STB's, one or more profiles and one or more applications associated with the open cable application platform. Even further aspects are directed toward providing advanced interactive and interoperable services to both obtain and distribute feedback about Advanced Common Application Platform (ACAP)/Open Cable Application Platform (OCAP)/Internet Protocol Multimedia Subsystem (IMS) services. BACKGROUND OF THE INVENTION [0006] Multiple Service Operators (MSOs), e.g., cable companies, are working to transform their value proposition from one dominated by basic subscriptions and equipment leases to a customer service driven value model. One of the reasons for this is the recent ruling by the Federal Communications Commission (FCC), which has been upheld in court, that MSOs adopt the Open Cable Application Platform (OCAP) and that Set-Top Boxes (STBs) be open to other uses. With larger pipes, more powerful STBs, and improved customer service applications residing in those STBs, the MSO can begin to dominate the other Local inter-Exchange Carriers (LECs). This enhanced customer service value equation is viewed to be one key to continued MSO growth, increased revenue and increased margins. OCAP is a new paradigm that will allow MSOs to create, or have made, and deploy, a whole suite of new interactive communications services that can drive new revenue streams with higher margins for the MSOs. The OCAP middleware, written in the Java® language, will facilitate “write once, use anywhere” application software to provide new features and services created by third party developers. [0007] The OpenCable™ Platform specification can be found at http://www.opencable.com/ocap/, “OpenCable Application Platform Specification (OCAP) 1.1,” which is incorporated herein by reference in its entirety. [0008] OCAP is an operating system layer designed for consumer electronics, such as STBs, that connect to a cable television system. Generally, the cable company controls what OCAP programs can be run on the STB. OCAP programs can be used for interactive services such as eCommerce, online banking, program guides and digital video recording. Cable companies have required OCAP as part of the CableCard 2.0 specification, and they indicate that two way communications by third party devices on their networks will require them to support OCAP. [0009] More specifically, OCAP is a Java® language-based software/middleware portion of the OpenCable initiative. OCAP is based on the Globally Executable MHP (GEM)-standard, as defined by CableLabs. Because OCAP is based on GEM, OCAP shares many similarities with the Multimedia Home Platform (MHP) standard defined by the Digital Video Broadcasting (DVB)-project. The MHP was developed by the DVB Project as the world's first open standard for interactive television. It is a Java® language-based environment which defines a generic interface between interactive digital applications and the terminals on which those applications execute. MHP was designed to run on DVB platforms but there was a demand to extend the interoperability it offers to other digital television platforms. This demand gave rise to GEM, or Globally Executable MHP, a framework which allows other organizations to define specifications based on MHP. [0010] One such specification is OCAP which has been adopted by the US cable industry. In [0011] OCAP the various DVB technologies and specifications that are not used in the US cable environment are removed and replaced by their functional equivalents, as specified in GEM. On the terrestrial broadcast side, CableLabs and the Advanced Television Systems Committee (ATSC) have worked together to define a common GEM-based specification, Advanced Communications Application Platform (ACAP), which will ensure maximum compatibility between cable and over-the-air broadcast receivers. [0012] Packet Cable 2.0 is a specification based on the wireless Third Generation Partnership Program (3GPP) Internet protocol Multimedia Subsystem (IMS), which uses Session Initiated Protocol (SIP) for session control. By using SIP, MSOs can create the foundation of a service delivery platform on top of their existing DOCSIS (Data Over Cable Service Interface Specification) or cable modem service. Two of the SIP features that are particularly important to this invention are extensibility and interoperability. These SIP features are important because new messages and attributes can be easily defined and communications between previously incompatible endpoints are facilitated. [0013] Another development that sets the stage for the disclosed inventions is the processing power, multimedia codecs and storage capabilities of the STBs. Many of the more advanced STBs have Digital Video Recorders (DVRs) based on hard disk drives or flash memory that provide many gigabytes of available storage. They also have advanced audio/video codecs designed to handle the requirements of High Definition Television (HDTV). Processors such as the Broadcom BCM7118 announced in January 2007, provide over 1000 Dhrystone mega-instructions per second (DMIPS) worth of processing power to support OCAP, new customer applications, and DOCSIS 2.0 and DSG advanced mode. The Broadcom chip, and other general purpose and application-specific integrated circuit (ASIC) processors used for STBs, provide powerful security capabilities such as the emerging Polycipher Downloadable Conditional Access Security (DCAS) system. DCAS eliminates the need for a CableCard and supports multiple conditional access systems and retail products. SUMMARY [0014] These technologies provide the platform for a greatly enhanced, multimedia, customer communication experience. Specifically, one exemplary aspect of this invention is advanced multimedia communications via OCAP using customer specific profiles resident in the STB. Telephony application servers have already been proposed by CableLabs and others. Phone and STB association can be done in the MSO network. Similarly, personalized information for the display of financial data, home security information and the like, is also known. [0015] However, an exemplary aspect of this invention utilizes storage of personalized information and communication preferences in the STB in a structured format or via cookies. The combination of feature rich telephony applications with the personalized data stored in STBs facilitates feature rich communications sessions. Providing advanced multimedia communications applications using personalized data resident in STBs could allow the MSOs to provide, for example, many previously unavailable services, and therefore provide considerable new business potential. [0016] The types of personal information that can be stored in STBs may include, but are not limited to, communication preferences, payment preferences, vendor preferences, priority preferences, personal information, etc. Examples of communications preferences could include when to be reached or not reached, e.g., receive an incoming communication(s), numbers to be reached on, calendar synchronization, etc., and in general any information related to communications. Examples of payment preferences could include credit card information, direct deposit/debit information, what financial instrument was used for the most recent transaction with a specific company, and in general any information related to transactions. Examples of vendor preferences could include favorite delivery pizza, most commonly ordered items, etc. Examples of priority preferences could include conditions like don't interrupt me watching the Chicago Bears beat the Green Bay Packers unless it is my boss calling, and in general any preference that can be used to assist with priority determinations. Examples of personal information could include clothing or shoe size, favorite colors, name, address, etc., and in general any information about an individual(s). Other such personal information categories and variations stored in STBs as can be imagined by one schooled in this art are also within the scope of this invention disclosure. [0017] Screen menus, pushed URLs, and adaptations specific to various devices connected to STBs (such as different size screens, different capability devices, etc.) can be rendered as part of this process of enhanced communications. Similarly contextual favorites or preferences can be provided depending on what content is being displayed or interacted with. [0018] When one combines the integration of a profile, such as, for example, personal information in STBs, with applications resident in a variety of places on the MSO's network, these new value added services are enabled. [0019] A few simple examples of what is possible could include, but are not limited to, enhanced web enabled service transactions, mobile requests for goods or services using the profiles and communication capabilities of the STB/MSO network, display of or sharing of information among two or more individuals, etc. [0020] For example, the user can initiate a service transaction on the STB itself. The exemplary menu based request will use the stored service information entry to key a web service request. If the request should trigger a human response (like communication with a retention agent when service cancellation is requested), then the STB information can key to the customer phone for an outbound call to confirm the cancellation request and allow the agent to describe a retention offer. [0021] Another example could be a user delayed at work wanting to order a pizza to be ready shortly after their arrival at their home. The user can access personal information in their remote STB about their preferred vendor, most recent order and previous method of payment. They can place a new pizza order based on this stored information rather than having to key or speak all this information while driving. The user benefits from an enhanced user experience, the accuracy of the order is improved, and they can have the food arrive closely timed with their own arrival at home. [0022] Another example is when a user has relocated to a new city or state; they may not have had the time to develop favorite vendors for pizza or other goods and services. In such a case, the MSO can push a list of preferred partners to the new user that the new user can edit or modify based on their own personal experiences and preferences. [0023] The exemplary embodiments discussed herein just hint at the power of the proposed enhancement to this new communications paradigm. There are many other potential examples and applications to serve them that are possible. [0024] For example, it is generally recognized that an intelligent agent is a software agent that assists users and will act on their behalf, in performing non-repetitive computer-related tasks. An agent in this sense of the word is like an insurance agent or a travel agent. While the working of software agents used for operator assistance or data mining (sometimes referred to as bots) are often based on fixed pre-programmed rules, “intelligent” in this context is often taken to imply the ability to adapt and learn. The term “personal” indicates that a particular intelligent agent is acting on behalf of an individual or a small collective group of users such as a household, business entity, etc. [0025] OCAP provides another venue for an intelligent personal agent but offers several advantages compared with previous attempts at this type of application. One is the fact that STBs are already equipped to handle two-way, full-motion, High Definition (HD) video, as well as any other communication media. Another advantage is the integration of the personal profile information with the Intelligent Personal Agent application. Another is the improved security discussed herein. The extensibility and the interoperability that the Session Initiation Protocol (SIP) adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged. [0026] Another exemplary aspect of the invention is the use of personalized information and personal preferences contained in a STB in combination with an intelligent personal agent application and improved security to provide, for example, a greatly enhanced user agent experience. [0027] The fact that sensitive information about the user can be stored within their own STB reduces security concerns associated with having too much web presence. The disclosure or query of the personal information can be established on a trust basis which also helps with security and privacy. The push of security information such as DCAS makes the environment significantly safer. One could also envision if there are multiple users within one household, that they can each have a profile that is login protected for personal privacy. Parents would be able to set certain conditions/limits for children using the intelligent personal agent application that would also add to the safety and age appropriate use of the application. [0028] The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to current intelligent personal agents. It could provide an opportunity for video messages to be personalized for the party which is initiating the contact. [0029] The personal information stored in the STB can convey many exemplary benefits such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, as well as multimedia messaging, etc. The integration of the personal information with the intelligent personal agent also enhances the user experience. [0030] There are several examples of what this idea can provide the user that current intelligent agents are not able to do. One is the ability to greet calling parties with a full motion video greeting unique to that calling party. Another is the ability to handle more complicated transactions. For example, the user wants to buy a particular item at a particular price from one of several preferred vendors. Offers from preferred business partners can be pushed to the MSO's users and the content can be filtered, compared with conditions set by the user for a purchase, and the intelligent personal agent can either complete the transaction or call the user on a mobile device to seek approval and then transact business. While there are shopping agents, mobility applications and contactless payment devices, this intelligent agent can provide a user experience unequaled in the current art. Another possible variation is for the intelligent personal agent to coordinate multiple parties within a household. Let's say an invitation arrives inviting a family over to dinner at the calling party's house. The intelligent agents can interact with personal information and scheduler software for all of the members of the family to make certain that the invite has considered each members previous commitments prior to replying and either accepting or modifying the proposed dinner invitation. There are numerous other variations that are possible with this intelligent personal agent not possible within the existing art. [0031] Social network services focus on the building and verifying of online social networks for communities of people who share interests and activities, or who are interested in exploring the interests and activities of others, and that necessitates the use of software. [0032] Most social network services are primarily web based and provide a collection of various ways for users to interact, such as chat, messaging, email, video, voice chat, file sharing, blogging, discussion groups, and so on. [0033] The main types of social networking services are those that contain directories of some categories (such as former classmates), means to connect with friends (usually with self-description pages), and recommender systems linked to trust. Popular methods now combine many of these, with MySpace™, Bebo™ and Facebook™ services being the most widely used. [0034] OCAP combined with personal profile information provides another venue for a social network, but offers several advantages compared with previous attempts at this type of application. One is the fact that, as discussed, STBs are equipped to handle two-way, full-motion, High Definition (HD) video. Another is the improved security discussed above. The extensibility and the interoperability that SIP adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged. One exemplary embodiment of the social network proposed here can be one-to-one, one-to-many and many-to-one, and can cover both personal and professional interest areas. [0035] Another exemplary aspect of this invention is the use of personalized information and personal preferences contained in a STB combined with two-way, full-motion, HD video and improved security to provide a greatly enhanced social networking experience. [0036] The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to the current social networking offerings. It would provide an experience that is much more like a face-to-face interaction. [0037] The personal information stored in the STB can convey all of the benefits listed above such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, etc. The integration of the personal information combined with the social networking application(s) also enhances the user experience. [0038] In addition to the normal uses of a social networking application such as on-line dating, discussion groups, virtual communities, and the like, one can imagine extensions to the use of this application. One such extension would be the addition of personal reviews of restaurants, movies, books, music, and the like. Other users of the social network could determine over time which reviewers tend to rate goods and services consistently with their interests and/or from a perspective that they enjoy their reviews, and could preview the ratings provided about items of interest by those reviewers. One could also see reviews when previewing related media. The reviewers and the users that tend to agree or become popular could go on to form their own social network based on their experience with each other's recommendations or interactions. With the extensibility of Packet Cable 2.0, a user could also provide a review of a movie that they had just viewed in a theater via their cell phone while their thoughts are fresh. [0039] Many small businesses start out as part-time home businesses. In addition, some people run a small business focusing on rental properties, or the like, in parallel with their normal employment. Some fairly sizable businesses are run at locations served by MSO DOCSIS services. OCAP provides an opportunity to integrate business profile information into STBs similar to how personal information is integrated in a STB, as discussed in above. Further, business application software, such as the Quicken® Home and Business program or the Quicken® Rental Property Manager program can be advantageously integrated together with business information profiles in the STB. [0040] There are many other instances where OCAP can provide an enhanced user experience to business users. Via OCAP, and with a business profile, actual inventory levels can be compared with desired levels stored as business information in the STB. Since preferred vendor and preferred payment information can also be stored, when inventory runs below a certain level, it can be automatically ordered, or alternatively, OCAP can provide a pop-up or call a specified phone number such as a mobile phone to confirm that the inventory reorder should be processed. [0041] Another example would be management of a rental vacation property. Not only could the landlord view bookings and the like, but the ability to extend a rental stay could be offered to the guest via the TV/STB when such an opening is available. Further, an offer to return at a future date could also be made via OCAP. In this way, the renter feels that they are getting increased attention without significant intrusion, and the landlord is more likely to be able to keep the rental property at maximum capacity. [0042] While the internet provides some of these types of features, OCAP allows for, as an example, a richer feature set, improved convenience, and the ability to leverage previously incompatible devices in a seamless way. Specifically, the ability to reorder inventory when the small business owner is mobile, and the ability to provide all of the information regarding the transaction such as vendor, inventory type and quantity, preferred payment options, and the like, without the small business owner having to key in such information, is useful. Similarly, renting vacation properties is typically done via the internet. However, not everyone takes a PC or web-enabled device everywhere with them. Offering the ability to extend a stay, rebook a future vacation, or offer incentives to good repeat guests can all be done via OCAP and displayed on a TV or forwarded as an audio message to the rental property phone. [0043] The use of business information and business preferences contained in a STB integrated with other PC or STB-based business software can provide full compatibility with previously incompatible endpoints and improved security to provide a greatly enhanced business experience. [0044] The fact that sensitive information about business(es) can be stored within their own STBs improves security concerns associated with web-based attacks. The disclosure or query of the business information can be established on a trust basis, which also helps with security and privacy. The push of security information, such as DCAS, also makes the environment significantly safer. One could also envision, if there are multiple users within one entity, that they can each have a profile that is login protected for privacy. In addition, one or more members of the entity can also have a business profile in the STB. [0045] The two-way, full-motion, HD video, without many of the quality issues associated with the Internet, is also a significant enhancement to businesses. It provides, for example, an opportunity for video messages to be personalized to the guest or customer when the business owner is unavailable. [0046] The business information stored in the STB can also convey the benefits of personal information listed above, such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, inventory levels, business events/calendar, as well as multimedia messaging, etc. The integration of the business information combined with existing business software enhances the business owners' ability to conduct their businesses. [0047] There are several examples of what this idea can provide to the business user that current PC based software does not allow. One is the ability to greet guests and customers with a full motion video greeting unique to each party. Another is the ability to handle more complicated transactions. For example, a vacation rental guest decides that they really like the property that they rented, but would like to consider other such properties for a future vacation prior to the end of their current vacation. Offers from the landlord can be extended to preferred guests while on their current vacation for reduced rate stays at this or other properties, to retain the guest's business. All of this can be displayed to the TV at the property, or if the TV is not used, sent via an audio message to the phone in the rental. There are numerous other variations that are possible with this business application and profile that are not possible within the existing art. [0048] An exemplary embodiment is directed toward one or more solutions that are capable of providing feedback information about OCAP/ACAP/IMS solutions generally related to audience acceptance and satisfaction, and extensions thereto. For example, one exemplary aspect is directed toward information, such as consumer feedback about their viewing choices, being gathered, evaluated and distributed. Even more specifically, an exemplary aspect is directed toward the use of information, such as personalized or customized information and personal preferences contained in an STB combined with an OCAP/ACAP/IMS intelligent personal agent and application(s) to provide advanced interactive and interoperable services to both obtain and distribute feedback about OCAP/ACAP/IMS services. [0049] In keeping with the design intent of OCAP/ACAP/IMS such feedback services are not possible nor are they as accessible, adaptable, extensible and commercially viable because the former can, among other things, more easily use a plethora of interfaces, products or other services. [0050] Even more specifically, there are behavior identification possibilities with OCAP/ACAP/IMS combined with personal profiles and intelligent agent technology that are not possible with any current technologies because the later lacks access to advanced presence services, among others. These behaviors can be shopping, purchasing, travel, use of social networks, other web services and many other types of behaviors. Furthermore, IMS can provide a decentralized application control via SIP, which makes such applications more commercially viable because they can be rapidly developed, more easily tested, flexibly configured and more widely deployed. Such SIP-based applications are easier to design because they may not be concerned with tedious and mundane core functions like authentication, authorization, routing and logging. Such SIP-based applications can also be distributed among a variety of application servers, and their clients can be anywhere in the network. Security, privacy and reliability are also vastly improved because services through the STB rather than PCs, that have well-known flaws and deficiencies. The new interactive and interoperable services possible with this idea can also better interface with the prior technologies than can the prior technology solutions themselves. Because solutions created by this idea are generally, in accordance of an exemplary embodiment, Java® based, they have access to mature software architecture design techniques and design patterns for building interfaces to other services and clients. [0051] In accordance with one exemplary embodiment, adaptors can be created to act as an intermediary between old and new services. Decorators can be available to flexibly add or remove components without necessarily changing external appearance, functions or functionality. Façade's can provide simplified interfaces to groups of subsystems or a complex subsystem. Flyweights can allow sharing of objects to reduce low-level detail that must be accounted for. Proxy's can provide a representative of an object to specifically control its access, speed and security. [0052] One simple exemplary aspect is the use of this technology to summarize an individual's television viewing choices and to automatically post them to, for example, social networking sites such as Facebook®, Twitter®, RSS feeds, blogs, microblogs, a shared website, or in general any location (on the internet). Another simple exemplary aspect would be to aggregate, compare, and contrast the television viewing choices of a group of Facebook® friends to create other web content. Conversely, a consumer could subscribe to a service that automatically downloads television programs to their STB based on a blog that matches the consumer's interest, RSS feeds of highly rated programs, or other web content that rate or review media. [0053] A more complex exemplary aspect is directed toward monitoring failures, due perhaps to cable outages, to record a cherished television program and automatically download it from one or more web sources. Multi-modal devices, such as iPhones, Blackberry's, or the like, could also be synchronized with a television program being viewed thereby allowing minute and detailed real-time feedback about the program or commercial being viewed. Moreover, parents can more flexibly control and regulate children's viewing habits, allowing more leeway regarding time of day, length of time viewing, chores and responsibilities like homework, psychological profiles, or the like. [0054] The system can also use automatic speech recognition (ASR) to detect, among other things, yelling and screaming proximate to the STB, laughter, or the like, to deduce a viewer's response to specific content. Furthermore, rating agencies can automatically poll viewers for additional information at strategic moments based on real-time data being gathered on the viewer and the content being provided. Passive, automatic, and biometrically-based audience preferences and responses can be automatically distributed to one or more rating agencies via, for example, a network connection, the internet, or the like. [0055] In accordance with yet another exemplary aspect, galvanic skin response, heartbeat, breathing rate, and in general any biometric information can be associated with a variety of psychological states, such as tension, for example, that would be of interest to content providers. Another example is eye dilation, associated with an increase in interest, could provide rating agencies with a viewer's, perhaps unconscious, response. Eye movements can also be monitored, traced, recorded, and analyzed with the cooperation of a camera, to reveal what is of specific interest to a viewer. Even more exotic noninvasive means of determining a viewer's state of mind can be envisioned by those schooled in the use of functional magnetic resonance imaging (fMRI), nuclear resonance medical imaging (nMRI) or the like. Use of these exotic means of feedback is more easily, privately, securely, widely distributed, and interfaceable to devices using OCAP/ACAP/IMS services. [0056] In accordance with yet another exemplary aspect, another solution is directed toward the preferences and ratings that are of benefit to the MSO, their business partners, content providers, regulators, investors or the like, which are enabled by the specific architecture disclosed herein. One simple example, among many, is found in issues related to STB performance (e.g., peak CPU usage), bandwidth usage, service outages or interruptions, or the like. Such can be provided to technical support, regulators, business partners, third-party service providers, suppliers or the like based on one or more criteria, choices, ratings, or the like, chosen by any one or more of these third-parties, or even made jointly by them using methods, attributes or the like, chosen according to their joint specification. [0057] One simple example is associated with a well-known cable provider. This cable provider has one of the worst consumer satisfaction ratings on record, and has disappointed not only consumers but also regulators, among others. Although this cable provider has now published byte limits for consumer downloads, their policy regarding bandwidth availability remains opaque. This cable provider has been accused, perhaps apocryphally, of arbitrarily restricting high-definition television bandwidth for some of its channels to conserve overall bandwidth usage. Such practices could be of special interest to the content providers for those channels or groups of channels. Therefore, one exemplary technique disclosed herein permits content providers and others to rank channels in importance thereby allowing a cable provider to restrict bandwidth in ways that are mutually agreeable among all affected and interested parties. [0058] Another exemplary embodiment is directed toward the use of personalized information and business preferences contained in an STB combined with an OCAP/ACAP/IMS intelligent personal agent application to provide advanced interactive and interoperable services to both obtain and distribute feedback about such OCAP/ACAP/IMS services. [0059] These and other advantages will be apparent from the disclosure of the invention(s) contained herein. [0060] The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. [0061] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably. [0062] The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic even if performance of the process or operation uses human input, whether material or immaterial, received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material”. [0063] The term “computer-readable medium” as used herein refers to any tangible storage and/or transmission medium that participate in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read. A digital file attachment to e-mail or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the invention is considered to include a tangible storage medium or distribution medium and prior art-recognized equivalents and successor media, in which the software implementations of the present invention are stored. [0064] The terms “determine”, “calculate” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique. [0065] The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the invention is described in terms of exemplary embodiments, it should be appreciated that individual aspects of the invention can be separately claimed. [0066] The preceding is a simplified summary of the invention to provide an understanding of some aspects of the invention. This summary is neither an extensive nor exhaustive overview of the invention and its various embodiments. It is intended neither to identify key or critical elements of the invention nor to delineate the scope of the invention but to present selected concepts of the invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS [0067] FIG. 1 illustrates an exemplary content system; [0068] FIG. 2 illustrates an exemplary set-top box; [0069] FIG. 3 illustrates an exemplary profile; [0070] FIG. 4 is a flowchart outlining an exemplary method for tracking viewer choices; [0071] FIG. 5 is a flowchart illustrating an exemplary method for developing content recommendations; [0072] FIG. 6 is a flowchart illustrating an exemplary method for downloading content based on a feed; [0073] FIG. 7 is a flowchart illustrating an exemplary method for monitoring quality; [0074] FIG. 8 is a flowchart illustrating an exemplary method for syncing with one or more other devices; [0075] FIG. 9 is a flowchart illustrating an exemplary method for providing feedback to a content provider; [0076] FIG. 10 is a flowchart illustrating an exemplary method for monitoring viewers; [0077] FIG. 11 is a flowchart illustrating an exemplary method for monitoring biometric information; and [0078] FIG. 12 is a flowchart illustrating an exemplary method for monitoring performance metrics. DETAILED DESCRIPTION [0079] FIG. 1 illustrates an exemplary content system 100 . The content system 100 comprises one or more trusted entities 200 , one or more content/service providers 300 , such as a cable company, and a set-top box 500 , all interconnected by one or more links 5 and networks 10 . The set-top box 500 is connected to one or more of a stereo 700 , PC 800 , TV 900 , or in general any electronic device as represented by box 600 . Associated with the set-top box 500 are one or more profiles 400 , as will be discussed in detail hereinafter. [0080] In general, the set-top box 500 is capable of receiving content, such as video content, as well as providing services such as access to the internet, telephony services, and the like. As will be discussed hereinafter, the set-top box 500 is also capable of providing services such that, for example, the user located at one of the attached devices utilizes the set-top box 500 to assist with the ordering, consumption and/or management of the service. [0081] Typically, the content/service provider 300 provides content, such a video content, to a user via the set-top box 500 . An exemplary embodiment of the present invention expands on this concept and in conjunction with profile 400 provides enhanced content capabilities and interactive and interoperable services through the set-top box 500 . [0082] Furthermore, and in accordance with an optional exemplary embodiment, trusted relationships can be established between the content/service provider 300 and one or more trusted entities 200 . For example, the content/service provider 300 , such as a cable company, can negotiate trusted relationships with various service providing entities. Upon the completion of various checks and assurances from the service providing entities, the various entities could be listed as a trusted entity 200 , at which point service requests made via set-top box 500 , in conjunction with profile 400 , could be handled in a different manner. [0083] The association of the profile 400 with the set-top box 500 allows, for example, a richer communications environment to be provided to a user. For example, a customer at their home calls into a customer service number. Instead of the call being rerouted from center to center based on information the customer inputs via the phone, the call can use a common customer routing center. The routing center, which could be one of the trusted entities 200 , can use the phone number to look-up a key set-top box entry for the customer, and the center can then electronically retrieving the stored service information entry via the set-top box 500 , from the profile 400 . The information retrieved from the profile 400 can be combined with the caller's requested service, routed to the appropriate agent with the information retrieved from the customer STB (relieving the need to interrogate other databases or the user and making for more efficient contact centers), and additional information for the customer can be displayed on, for example, the TV 900 or PC 800 associated with the set-top box 500 . [0084] In another example, the customer can initiate a service transaction on the set-top box 500 itself. For example, a menu based request can use stored service information in the profile 400 to key a web service request. If the question triggers a human response, like that from a retention agent when service cancellation is requested, the set-top box information can key to the customer phone for an outbound call to confirm the cancellation request and allow for a retention offer to be made. [0085] Therefore, in accordance with one exemplary embodiment, the profile 400 can be used, for example, to assist with contacts to a contact center and can be utilized in conjunction with the set-top box 500 to provide a service to, for example, other retailers, service outfits, and trusted or other entities. The set-top box 500 can also store customer service records specific to, for example, an individual or a business, as discussed above. The same method used to assist with a customer service contact as discussed above could similarly be used to access records or other information stored in the profile 400 to assist with business services, business management, online banking, or the like. [0086] For example, the same mechanisms can be used to push structured information and menu information for the requested transaction, inquiry, or service request, thereby providing a richer customer service experience. This richer experience combined with the ease of retrieval of customer service information, personal information and/or business information from the profile 400 provides, for example, a significantly richer customer contact capability than that which can be offered by traditional centers. This in turn gives an opportunity for new large business service opportunities for the contact/service provider 300 . [0087] In accordance with an exemplary embodiment, the profile 400 used in conjunction with one or more applications on the set-top box 500 provides a richer experience for a user of the set-top box for interacting with one or more content/service providers, trusted entities, other entities, or in general any entity that may be able to provide a richer customer experience based on the information available to them via the profile 400 . [0088] FIG. 2 outlines in greater detail an exemplary STB 500 . In particular, the STB 500 includes optional DVR 510 , one or more codec(s) 515 , hard drive 520 , one or more customer service applications 525 , a hardware/software binding module 530 , a menu module 535 , a communications module 540 , feedback module 545 , processor 550 , memory 555 , I/O interface 560 , SIP functionality/integration module 565 , security module 570 , communications applications 575 , intelligent agent module 580 , presence module 585 , integrated messaging service module 590 , adaptor module 592 , decorator module 594 , façade module 596 , flyweight module 598 , proxy module 502 , web interface and outreach module 504 , and behavior identification module 506 . [0089] In accordance with the first exemplary embodiment, the set-top box 500 is intergratable with one or more social networking sites, RSS feeds, or other internet locations. For example, and in cooperation with the web interface and outreach module 504 , intelligent agent module 580 , hard drive 520 , processor 550 , memory 555 and I/O interface 560 , viewer choices are tracked. These viewer choices can be agnostic to the actual user utilizing the set-top box 500 or, for example, can be specific to a particular user, such as the example where a user logs on to the set-top box 500 , thereby invoking a profile stored in profile 400 , thereby making their viewing choices user-specific. Their viewing choices can be tracked and stored, for example in hard drive 520 , and, for example, based on one or more rules uploaded to one or more destinations. As an example, say a particular user stores in their profile that they would like to post their viewing choices to a particular social networking site, along with supplemental information such as when they watched the particular content, as well as any commentary they may have regarding the viewed content. Set-top box 500 cooperating with the menu module 535 and web interface and outreach module 504 can automatically post this information to an internet destination(s) as well as provide the user the ability to supplement the posted information with information such as notes, comments, or the like. Web interface and outreach module 504 , cooperating with the profile module obtains the necessary user IDs, passwords, log-in credentials, and the like, and then posts this information to a particular internet destination. As will be appreciated, this internet destination can be specified in, for example, profile 400 which could also include preferences as to formatting, frequency of posting, and in general maintain any characteristic, or aspect of how, when and where the information should be posted. [0090] In accordance with another exemplary embodiment, the set-top box 500 ability to interface with web content is expanded to include the ability to aggregate, compare and contrast television viewing choices with a group of friends, to one or more of create other web content, and/or trigger one or more events. For example, and again in cooperation with profile 400 , a user can identify one or more groups that are to be tracked. The set-top box 500 is then optionally capable of coordinating with the other set-top boxes associated with other viewers within the group, optionally in cooperation with a server or other internet resource, such that the viewing choices of the members within the group can be tracked. Again, this can be regulated by one or more rules within the profile 400 that can optionally filter the system's ability to track some viewing choices, but not others. One or more of the intelligent agent module 580 , or another server (not shown), can then one or more of aggregate, compare, and contrast the viewing choices of the members within the group and one or more of develop content and recommendations based thereon. For example, if numerous members of the group are watching a particular series of shows, this information could be communicated, with the cooperation of communications module 540 , to the other users in the group who do not appear to be watching the same content. In an even more dynamic application, and in cooperation with presence module 585 , if all but one member of the group is watching a particular show, the presence module 585 determines that the member of the group not watching the show is home, but not tuned in, the presence module 585 can cooperate with the communications module 540 to, for example, notify the user that all of the other members of the group are watching a particular show, and they may want to tune in. The set-top box 500 could then, for example, automatically tune to or begin recording the particular show that appears to be of interest. [0091] As another example, the integrated messaging service module 590 , optionally cooperating with the hardware/software binding module 530 and profile 400 , could generate and send a message to, for example, the user's mobile communication device communicating that the other members of the group are watching a particular show that is currently being aired. The user could then be provided the option of having the set-top box 500 automatically stream, with the cooperation of one or more communications applications 575 , the particular show to the user's mobile communication device. [0092] In accordance with another exemplary embodiment, deviating from the traditional TV Guide-type of approach to determining which content to watch, a user, in cooperation with the intelligent agent module 580 , can subscribe to one or more blogs, RSS feeds, or other internet resources, with one or more of these resources providing, for example, recommendations for highly rated programs, or other content, that should be viewed. The set-top box 500 , cooperating with the intelligent agent module 580 , DVR 510 , and the web interface and outreach module 504 , could then automatically download the one or more recommended shows and save them for viewing by the user. As with the other embodiments described herein, one or more rules, stored in the profile 400 , could optionally be overlaid on top of this functionality to filter or otherwise regulate the content being downloaded to the STB 500 . [0093] In accordance with another exemplary embodiment, one or more customer service applications 525 running on the set-top box 500 can monitor one or more of set-top box failures, quality of the received signal, and quality of one or more stored programs. This information can then be utilized by the set-top box to assist with, for example, ensuring content requested by the user is available to that user in its entirety, and at a specific or better quality metric. [0094] For example, if during the recording of a particular show, noise interfered with the recording of that show thereby creating static for 7 minutes of the recorded program. Customer service application 525 can detect this static, and automatically commence re-downloading of the show when it is determined, for example, that the communication channel has been cleared up. The customer service application 525 can coordinate the re-downloading of this content with the service provider, the service provider having the option of directing the customer service application 525 to, for example, one or more other sources where the content may be available at a better quality. This can also be extended to cover the situation where perhaps failures, cable outages, noise, and the like, was not a problem, but perhaps the downloaded content was only available at 480i, yet the user requested all downloaded content be stored at 1080p. Customer service applications 525 , again cooperating with profile 400 , and quality metrics stored therein, can optionally automatically and dynamically reach out to one or more content providers to ensure content, in the proper format, is obtained for viewing by the user. [0095] In accordance with another exemplary embodiment, other devices such as multi-modal devices, such as iPhones, Blackberry's, or the like, can be in communication with the set-top box 500 , for example, wirelessly, via Bluetooth®, or in general any communications modality, with the multi-modal device capable of being synchronized with the set-top box 500 and one or more television programs being viewed. This can allow, for example, minute and detailed real-time feedback about the program, or even commercial, being viewed to be obtained. More specifically, the communications module 540 , optionally cooperating with the SIP functionality/integration module 565 and information stored in profile 400 , and optionally in cooperation with presence module 585 , can detect when a viewer is viewing a particular program, and whether or not they have their multi-modal communication device available. If the presence module 585 determines that the multi-modal communication device is available to the user, this information can be used, for example, by one or more customer service applications and a content provider to commence providing information to that communications device. The information can be sent to the communications device via the set-top box 500 and in cooperation with one or more of the communications module 540 and communications applications 575 , with the set-top box 500 acting, for example, as an access point for the communications device, and/or the information communicated to the communications device via traditional techniques. [0096] In accordance with this exemplary embodiment, the communications device provides another modality on to which a content provider could provide additional content, polls, questions, advertising, or in general any information, that may or may not be related to, for example, the program the user is currently watching. This could be particularly advantageous if, for example, a service provider would like to solicit particular feedback from a user, and for example, an elegant input device is not currently associated with the set-top box. For example, and based on information in profile 400 , the content provider could determine that the user has a qwerty-style keyboard associated with their communications device, the presence module 585 has determined that the communications device is with the user and the user is watching a particular program. With this information, a service provider could, for example, assemble and forward user-specific questions which then could be answered using the QWERTY keyboard on the mobile communications device by the user. With this information being returned, for example with the cooperation of one or more of the SIP functionality/integration module 565 , customer service applications 525 , communications module 540 , and communications application 575 to the content provider. This synchronization functionality could be extended to allow, for example, the multi-modal device to act as an input device to the set-top box 500 in cooperation with the communications module 540 and communications application 575 . [0097] For example, the multi-modal device could be equipped with one or more applications that allow the multi-modal device to control the functionality of the set-top box, as well as allow input received, for example from the keyboard, to be provided to the set-top box 500 . Extending this functionality even further, and in that many multi-modal devices include cameras, microphones, video cameras, and the like, all the information obtained from these various sources could also be shared with the set-top box 500 and, for example, stored, forwarded to another destination, or the like. In accordance with one exemplary embodiment, any feedback or information received from the multimodal device can be utilized by one or more of regulators, business partners, third-party service providers, suppliers, content providers, or the like to, for example, assist with providing better customer satisfaction. [0098] In accordance with another exemplary embodiment, the set-top box can be equipped with a microphone and/or video camera (not shown) that are capable of detecting speech and such things as yelling, screaming, laughter, alone or in combination with automatic speech recognition of speech to deduce a viewer's response to specific content. All of these response-type actions can be monitored by the set-top box 500 , and in cooperation with the customer service application 525 , provided to one or more entities to track the viewer's reactions. Moreover, the intelligent agent module 580 can cooperate with an automatic speech recognition engine to monitor for certain words and/or key phrases that can be used to also provide a better customer service experience. For example, if an automatic speech engine detects one of the viewer's saying “What did she say?” the intelligent agent module 580 can, for example, rewind the program 30 seconds and turn up the volume to assist with improving the user's customer experience. In general, this functionality can be expanded such that a user is also capable of utilizing verbal commands to control one or more functions associated with the set-top box 500 , as well as using verbal commands as input to, or responses to, questions, polls, or the like, provided by a service provider to the set-top box 500 . [0099] As yet another example, rating agencies can automatically poll viewers for additional information at strategic moments based on real-time data being gathered on the viewer and the content being provided. Even more specifically, and in cooperation with one or more of communications applications 575 , web interface and outreach module 504 , processor 550 , memory 555 , I/O interface 560 , hard drive 520 and menu module 535 , one or more polls can be provided by the set-top box 500 on, for example, an associated device such as TV, personal computer, or the like, or as discussed previously, provided to a communications device associated with the user. The user could then use, for example, their remote control, communications device, or the like, to provide feedback to the targeted polling with the responses thereto being returned, with the cooperation of the communications applications 575 and communications module 540 , to for example, a content provider, regulator, business partner, third-party service provider, suppliers, or the like. [0100] In accordance with another exemplary embodiment, one or more of passive, automatic and biometrically-based audience preferences and responses can be automatically distributed to rating agencies via the web with the cooperation of the web interface and outreach module 504 . As discussed, any type of biometric can be monitored in cooperation with an associated biometric monitoring device (not shown) to one or more of monitor, trace, record, and analyze one or more biometric events associated with one or more viewers of content being provided by the set-top box 500 . This information can be harvested and, for example, distributed to one or more entities, such as content providers, third-parties, suppliers or the like, with the cooperation of the communications applications 575 and associated communications hardware. [0101] In accordance with yet another exemplary embodiment, and again in cooperation with customer service application 525 , communication application 575 , communications module 540 , processor 550 , memory 555 , I/O interface 560 and hard drive 520 , one or more performance metrics associated with the set-top box 500 are monitored. These performance metrics are compared against, for example, various thresholds with information as to whether the performance metrics have been met being provided to one or more of technical support teams, regulators, business partners, third parties, suppliers or the like. Additionally, these performance metrics can be provided to the intelligent agent module 580 , as discussed above, to assist with insuring the user is being provided with the quality of content and format of content they have specified in their profile. [0102] In accordance with yet another exemplary embodiment, the behavior identification module 506 , optionally cooperating with presence module 585 , is capable of tracking one or more of shopping, purchasing, travel, social network web site visits, web services, or the like, being utilized by the user of the set-top box 500 . These various behaviors may be of interest to one or more of the content providers, third-party service providers, or the like and can be monitored in a similar manner to the other monitored events and behaviors discussed herein. [0103] FIG. 3 outlines an exemplary profile 400 . The exemplary profile 400 comprises one or more of business, personal, and entity information 410 , communications preferences 420 , personal preferences 430 , payment information 440 , vendor information 450 , priority information 460 , contextual preferences and sub-profiles 470 , alternate contact modalities 480 and one or more trusted contacts 490 . [0104] As discussed, one or more of the personal, business and entity information can include any information that a user would like to store. For example, examples of personal information include name, address, credit card information, banking information, movie preferences, communications preferences, restaurant preferences, vendor preferences, billing preferences, and the like. Examples of business information includes, for example, preferred vendors, banking information, communications preferences, ordering or inventory information, employee information, payment information, accounting information, business management information, or in general any information related to a business. Entities can also include information about items such as groups of individuals, groups of businesses, or in general any entity that may not be personal or business in nature. Interfaces that can be provided that provide access to the information stored within the profile, and this information can be edited, updated or deleted as appropriate. The editing, updating or deleting of this information can be performed via an interface on the set-top box, or via any interface connected to the set-top box. This access to the information within the profile can be password protected, and the information can be transferred via or in accordance with well known encryption techniques and standards. [0105] The communications preferences 420 provide to the user the ability to store various types of communications preferences or modalities that can affect not only the type of communication to use to access the user, e.g., video, chat, IM, telephone, or the like, but that can also be used in conjunction with presence information and/or communication routing. [0106] The personal preferences 430 are a set of rules related to a particular user's personal preferences. These personal preferences can relate to any functionality of the set-top box, display characteristics of the STB, operation of the STB, or the like, and can be related to any one or more of menu options, communications preferences, contact preferences, set-top box management, or the like. [0107] Vendor information 450 stores various information that can be used for the payment of goods and/or services ordered through or in conjunction with the set-top box 500 . This payment information can have a higher security level than other types of information within the profile 400 , such that, for example, a password is required before the purchase for goods and services can be made. Additionally, the payment information could be limited to use by the contact/service provider 300 . [0108] Vendor information 450 can include such information as preferred vendors, vendors who should not be used, historical purchase information, account information, reference information associated with a particular vendor, or in general any information associated with a vendor. When new vendors are utilized, and in conjunction with the intelligent agent module 580 , new information can be added to the vendor information 450 and stored in the profile 400 . [0109] In addition, also in conjunction with the intelligent agent module 580 , the vendor information 450 can be dynamic such that as, for example, a user accesses a particular vendor's website, account information can be populated into the vendor information 450 such as order placed, remaining balance, special offerings, or in general any information associated with that particular vendor. [0110] Priority information 460 includes any information, such as rules, that can be used to assist with prioritizing certain activities, applications, or in general, any functionality associated with the set-top box 500 . This priority information 460 could also be used in conjunction with the intelligent agent module 580 to assist with determining prioritization of certain activities. [0111] The contextual preferences and sub-profiles 470 establishes preferences based on context that could also be categorized as sub-profiles depended upon, for example, a particular application being run on the set-top box 500 . As with the other types of information, the contextual preferences 470 can be used in conjunction with the intelligent agent module 580 to provide dynamic application behavior. [0112] The alternate contact modalities 480 outline various contact modalities for a particular user. These alternate contact modalities 480 can be used with the communication preference information, personal preference information and/or priority information to assist with completion of an incoming communication to an endpoint. For example, based on information in the alternate contact modalities profile, one or more of the binding module and SIP functionality module can be utilized to complete an incoming communication to an endpoint where the user is located or to a device associated with the user. [0113] Trusted contacts 490 include information regarding one or more entities that are trusted. For example, an entity can be trusted if it is approved by the content/service provider 300 . Additionally, an entity can be trusted if, for example, the user has had previous interactions with the entity and has identified them it as being trusted. [0114] Optionally, the intelligent module 580 can also be used to analyze transactions with a particular entity, and upon, for example, a threshold number of transactions being completed in a satisfactory manner, the entity can be identified as “trusted.” [0115] The trusted entities need not be limited to businesses that sell goods and/or services, but can also include entities such as schools, other individuals, or in general any one or any entity that is identified as being trusted. For example, in a social networking environment, parents can establish rules that can identify certain chat groups or other users that are trusted. In conjunction with the intelligent module, for example, a child can request a parent to approve a specific entity as trusted, and communications with that entity are restricted until it is approved by that parent. [0116] Trusted status can also be achieved by, for example, the intelligent agent module 580 analyzing an entity's, user's or merchant's feedback. Upon a merchant having reached a threshold level of feedback, the agent can identify the merchant as “trusted” which could then, optionally, forward the “trusted” identification to an additional entity, such as a parent, for final approval. [0117] FIG. 4 is a flowchart outlining an exemplary method of operation of the set-top box 500 . In particular, control begins in step S 100 and continues to step S 110 . In step S 110 , the viewing habits of one or more viewers can be tracked. Next, in step S 120 , one or more rules can be applied that filter the recorded viewing habits. Then, in step S 130 , one or more of the viewing habits can be posted to, for example, one or more internet destinations in conjunction with an associated log-in and posting application associated with the set-top box 500 . As discussed, the set-top box 500 can include information as to where the viewing habits are to be posted, with this optionally being dynamically determined, based, for example, on the type of viewed content. For example, if the viewing habits are for specific science and nature shows, these viewing habits could be posted to a first internet destination. Alternatively, if the viewer has been watching car races, this could be posted to a second internet resource. Moreover, optionally in conjunction with posting the viewing habits, the user can optionally supplement this information with their own comments as well as with information that is obtainable by the set-top box, such as when the viewer watched it, how many times they watched in, and in general can include any information about the viewing habit. Control then continues to step S 140 where the control sequence ends. [0118] FIG. 5 is a flowchart outlining an exemplary method for sharing information amongst a group. In particular, control begins in step S 200 and continues to step S 210 . In step S 210 , a group is one or more of created and selected for which the various comparisons discussed herein are to be performed against. Next, in step S 220 , the viewing choices of the various members of the group can be accumulated. Then, in step S 230 , the viewing choices of the group can be aggregated, compared, contrasted with one or more members of the group, and optionally with one or more other groups. Control then continues to step S 240 . [0119] In step S 240 , one or more of content and recommendations can be formulated based on the aggregation, comparison, contrasting and analysis performed in S 230 . As an example, a website could be updated that shows, for example, statistics associated with the various members of the group. In addition, the website could be updated indicating that most members of the group liked a particular show, but did not like another show and on this basis a recommendation provided to watch the first show. Control then continues to step S 250 . [0120] In step S 250 , and more particularly, if a recommendation is developed, this can be communicated to one or more users in the group. This communication could be done, for example, by providing recommended viewings for the user to watch, with the STB optionally automatically capable of having downloaded those particular programs for viewing by the user. Another optional embodiment, and in step S 260 , one or more members of the group can be dynamically notified of actions being taken by other members of the group. These updates can be provided automatically and can be optionally provided dynamically in real-time to, for example, an internet location. As with some of the other exemplary embodiments discussed herein, this dynamic updating and intercommunication among the various users within the group can be supplemented with comments, notes, or other content provided by one or more of the users. Control then continues to step S 270 where the control sequence ends. [0121] FIG. 6 is a flowchart outlining an exemplary embodiment for providing content through the set-top box. In particular, control begins in step S 300 and continues to step S 310 . In step S 310 , the user subscribes to one or more of blogs, RSS feeds, internet channels, or the like. Next, in step S 320 , optionally governed by one or more rules and user preferences, content associated with one or more of the subscribed information sources are automatically downloaded to the set-top box 500 which can then be viewed by the user at any point in time. Control then continues to step S 330 where the control sequence ends. [0122] FIG. 7 is a flowchart outlining an exemplary method of monitoring set-top box performance. In particular, control begins in step S 400 and continues to step S 410 . In step S 410 , the set-top box 500 is monitored for one or more failures. Next, and optionally in step S 420 , one or more quality metrics associated with downloaded or received content can also be monitored. Then, in step S 430 , a determination made whether content should be (Re)downloaded to insure that quality metrics are met. As an option, this failure or lack of quality metric criteria, can be forwarded to one or more destinations, such as a service provider, and can optionally be logged by the set-top box 500 . Control then continues to step S 440 where the control sequence ends. [0123] FIG. 8 is a flowchart outlining an exemplary method for harvesting information from a user. In particular, control begins in step S 500 and continues to step S 510 . In step S 510 , the set-top box 500 , and content thereon, is synchronized with one or more other devices, such as a multi-modal telecommunications device. Next, in step S 520 , additional content can be forwarded and/or transmitted to the one or more synchronized devices. Then, in step S 530 , feedback and/or input can optionally be solicited and/or collected from the user associated with the communications device, which can be harvested and forwarded to one or more destinations. Control then continues to step S 540 . [0124] In step S 540 , the harvested information and/or feedback can be analyzed with control continuing to step S 550 , where the control sequence ends. [0125] FIG. 9 is a flowchart outlining an exemplary method for monitoring viewer's reactions. In particular, control begins in step S 600 and continues to step S 610 . In step S 610 , monitoring commences to one or more of automatic speech recognition, yelling, screaming, laughter, talking, or the like, being utilized to provide feedback to a content provider in step S 620 . This feedback can include volume information, identity information, to the extent available such as being able to distinguish between a male voice, a female voice, and multiple parties in proximity to the set-top box 500 , and in general can be directed toward any characteristic, quality or trait of the monitored information. Control then continues to step S 630 where the control sequence ends. [0126] FIG. 10 is a flowchart outlining an exemplary method for polling viewers. In particular, control begins in step S 700 and continues to step S 710 . In step S 710 , content is provided to one or more viewers. Next, in step S 720 , viewers are monitored within step S 730 polling information provided at, for example, specifically targeted points within a program. The responses to these polls can then be accumulated and forwarded to one or more destinations, with control continuing to step S 740 where the control sequence ends. [0127] FIG. 11 is a flowchart outlining an exemplary method for monitoring viewer behaviors with control beginning in step S 800 . Next, in step S 810 , one or more viewers are monitored for one or more of passive, automatic, biometric, or other responses. Then, in step S 820 , the results of this monitoring are harvested within step S 830 the results distributed to one or more destinations. Control then continues to step S 840 where the control sequence ends. [0128] FIG. 12 is a flowchart outlining an exemplary method for monitoring set-top box performance. In particular, control begins in step S 900 and continues to step S 910 . In step S 910 , one or more performance metrics, quality metrics, or other metrics are monitored. Next, in step S 920 , the one or more monitored metrics can be provided to one or more of technical support, regulators, business partners, third parties, suppliers, or in general to any destination as appropriate. As discussed, these metrics can be used by one or more of the above parties, and can also be utilized by the set-top box to trigger certain activities, such as re-downloading of content, that did not meet certain quality and/or performance metrics. Control then continues to step S 930 where the control sequence ends. [0129] A number of variations and modifications of the invention can be used. It would be possible to provide for some features of the invention without providing others. [0130] The exemplary systems and methods of this invention have been described in relation to STB's and profile(s). However, to avoid unnecessarily obscuring the present invention, the description omits a number of known structures and devices. This omission is not to be construed as a limitation of the scope of the claimed invention. Specific details are set forth to provide an understanding of the present invention. It should however be appreciated that the present invention may be practiced in a variety of ways beyond the specific detail set forth herein. [0131] Furthermore, while the exemplary embodiments illustrated herein show various components of the system collocated, certain components of the system can be located remotely, at distant portions of a distributed network 10 , such as a LAN, cable network, and/or the Internet, or within a dedicated system. Thus, it should be appreciated, that the components of the system can be combined in to one or more devices, such as a STB, or collocated on a particular node of a distributed network, such as an analog and/or digital communications network, a packet-switch network, a circuit-switched network or a cable network. [0132] It will be appreciated from the preceding description, and for reasons of computational efficiency, that the components of the system can be arranged at any location within a distributed network of components without affecting the operation of the system. For example, the various components can be located in a switch such as a PBX and media server, gateway, a cable provider, in one or more communications devices, at one or more users' premises, or some combination thereof. Similarly, one or more functional portions of the system could be distributed between a communications device(s), such as a STB, and an associated computing device. The one or more functional portions of the system could be also be installed in a TV or TV tuner card, such as those installed in a computer. [0133] Furthermore, it should be appreciated that the various links, such as link 5 , connecting the elements can be wired or wireless links, or any combination thereof, or any other known or later developed element(s) that is capable of supplying and/or communicating data to and from the connected elements. These wired or wireless links can also be secure links and may be capable of communicating encrypted information. Transmission media used as links, for example, can be any suitable carrier for electrical signals, including coaxial cables, copper wire and fiber optics, and may take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications. [0134] Also, while the flowcharts have been discussed and illustrated in relation to a particular sequence of events, it should be appreciated that changes, additions, and omissions to this sequence can occur without materially affecting the operation of the invention. [0135] In yet another embodiment, the systems and methods of this invention can be implemented in conjunction with a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device or gate array such as PLD, PLA, FPGA, PAL, special purpose computer, any comparable means, or the like. In general, any device(s) or means capable of implementing the methodology illustrated herein can be used to implement the various aspects of this invention. Exemplary hardware that can be used for the present invention includes computers, handheld devices, telephones (e.g., cellular, Internet enabled, digital, analog, hybrids, and others), and other hardware known in the art. Some of these devices include processors (e.g., a single or multiple microprocessors), memory, nonvolatile storage, input devices, and output devices. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, or virtual machine processing can also be constructed to implement the methods described herein. [0136] In yet another embodiment, the disclosed methods may be readily implemented in conjunction with software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized. [0137] In yet another embodiment, the disclosed methods may be partially implemented in software that can be stored on a non-transitory storage medium, executed on programmed general-purpose computer with the cooperation of a controller and memory, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated measurement system, system component, or the like. The system can also be implemented by physically incorporating the system and/or method into a software and/or hardware system. [0138] Although the present invention describes components and functions implemented in the embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. Other similar standards and protocols not mentioned herein are in existence and are considered to be included in the present invention. Moreover, the standards and protocols mentioned herein and other similar standards and protocols not mentioned herein are periodically superseded by faster or more effective equivalents having essentially the same functions. Such replacement standards and protocols having the same functions are considered equivalents included in the present invention. [0139] The present invention, in various embodiments, configurations, and aspects, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, configurations, and aspects, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and/or reducing cost of implementation. [0140] The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects of the invention may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention. [0141] Moreover, though the description of the invention has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

An exemplary aspect is directed toward one or more solutions that are capable of providing feedback information about OCAP/ACAP/IMS solutions generally related to audience acceptance and satisfaction, and extensions thereto. For example, one exemplary aspect is directed toward information, such as consumer feedback about their viewing choices, being gathered, evaluated and distributed. Even more specifically, an exemplary aspect is directed toward the use of information, such as personalized or customized information and personal preferences contained in an STB combined with an OCAP/ACAP/IMS intelligent personal agent and application(s) to provide advanced interactive and interoperable services to both obtain and distribute feedback about OCAP/ACAP/IMS services.

FIELD OF THE INVENTION [0001] The invention relates to the compositions and compounds for use in the treatment of gliomas. BACKGROUND TO THE INVENTION [0002] Malignant gliomas are the most common primary brain tumour and are associated with a very poor prognosis (Wrensch et al, 2002). It has been hypothesised that gliomas arise from endogeneous glial progenitor or neural stein cells (Canoll and Goldman, 2008), with which they share the ability to migrate along white matter tracts and perivascular and subpial spaces (Louis, 2006). As a consequence, malignant gliomas are highly infiltrative tumours for which complete surgical resection is not feasible. The limitations of conventional treatment modalities at adequately treating infiltrative tumour cells are highlighted by the observation that 80% of malignant gliomas recur within 2 to 3 cm of the original tumour mass (Hess et al, 1994). [0003] Herpes Simplex Virus (HSV-1) is a large, naturally neurotropic, double-stranded DNA virus that is actively being developed into useful replication-selective (oncolytic) and replication-defective gene therapy vectors (Bowers et al, 2003). To date, two replication-selective viral constructs have reached clinical trials in patients with malignant gliomas (Rampling et al, 2000; Marken et al, 2000; Papanastassiou et al, 2002; Harrow et al, 2004). These viruses, designated G207 and HSV1716, harbour null mutations in both copies of the γ 1 34.5 gene. The products of this gene are critical in enhancing the ability of HSV-1 to infect neurones and overcome host cell responses to viral infection (He et al, 1997). In addition, null mutations of the γ 1 34.5 gene confer the ability of these vectors to selectively replicate in tumour cells (Shah et al, 2003). [0004] To date, in all clinical trials of selectively-replicating HSV-1, vector administration has been achieved by direct intratumoural or intraparenchymal injection. Early clinical trials involved the direct injection of vector directly into the MRI-enhancing tumour mass (Rampling et al, 2000; Marken et al, 2000; Papanastassiou et al, 2002). These studies demonstrated safety and provided limited evidence of in vivo replication of HSV1716 in patients with malignant gliomas. However, conclusive evidence of significant vector distribution and treatment efficacy has yet to be demonstrated. Although this may relate to methodological difficulties of confirming vector replication clinically, there is significant uncertainty regarding the effectiveness of intratumoural injection (Dempsey et al, 2006). [0005] By definition Grade IV gliomas are characterised by areas of tissue necrosis (World Health Organisation, 2007). Consequently the direct inoculation of a necrotic primary tumour mass with a replication-selective viral vector capable of replicating within live malignant glioma cells is unlikely to efficiently treat either the primary tumour mass or more importantly, the infiltrating tumour cells. In addition, the primary tumour mass is often amenable to surgical resection rendering intratumoural injection of replication-selective vector unnecessary. Indeed, Harrow et al (2004) undertook a phase I/II study of peri-tumoural injections of HSV1716 in patients undergoing resection of either recurrent or newly diagnosed malignant gliomas. This study demonstrated this approach to be safe, although it is clearly critical that for this approach to be efficacious, viral distribution must be optimised to facilitate the transduction of as many infiltrating tumour cells as possible. [0006] Convection-enhanced delivery (CED) involves the use of fine catheters and precisely controlled infusion rates to distribute therapeutic agents by bulk-flow directly into the brain extracellular space, possibly along the same extracellular pathways that glioma cells are able to migrate. In contrast to techniques of drug delivery that depend on diffusion to achieve adequate drug distribution, such as carmustine-impregnated biodegradable polymers, with CED it is possible to distribute drugs homogeneously over potentially large volumes of brain, irrespective of the molecular size of the therapeutic agent (Morrison et al, 1994). As such it is an ideal technique for the administration of viral vector-mediated gene therapy to the brain of patients with malignant gliomas. [0007] HSV-1 vectors have a diameter of 120 to 300 nm (Jacobs et al, 1999), whereas on average the brain extracellular space has a diameter of 38 to 64 nm (Thorne and Nicholson, 2006). Clearly this has the potential to make the administration of HSV-1-based vectors by CED unachievable. Consequently, in this study the distribution of a replication-selective HSV-1 viral construct by CED has been examined in both grey and white matter and, a variety of strategies to enhance viral vector distribution have been evaluated. [0008] Nevertheless, in addition to the aforementioned clinical trials (6-9), HSV vectors have been administered by stereotactic injection into normal mouse (17-19), rat (20-26) and primate brains (20-28), animal models of high-grade glioma (29-35), mucopolysaccharidosis type VII(36), GM2 gangliosidosis (37) and Parkinson's disease (37-39), as well as being administered by CED into a glioma rat model (40). In view of this large number of studies it is surprising that to date no attempt has been made to systematically evaluate and optimise the delivery of these vectors directly into the brain. Consequently, in this study the distribution of a replication-selective HSV-1 viral construct by CED has been examined in both grey and white matter and, a variety of strategies to enhance viral vector distribution have been evaluated. SUMMARY OF THE INVENTION [0009] Based on the study, the inventors have identified compositions and compounds useful for optimising the delivery of therapeutic agents to white matter, especially by convection enhanced delivery. This is particularly useful for the delivery of gene therapy vectors. [0010] A first aspect of the invention provides a pharmaceutical composition comprising a therapeutic agent and albumin or a functionally effective fragment thereof. [0011] The composition preferably comprises a therapeutic agent for treatment of a neurological disease. The therapeutic agent is preferably for the treatment of a disease of the brain or spinal cord, especially a disease of the brain. It may be a cancer, especially a cancer of white matter, in particular a glioma. Alternatively, it may be any other appropriate neurological disease, especially a white matter disease such as multiple sclerosis. [0012] The therapeutic agent may be any agent for treatment of a neurological disease, such as a gene therapy agent, especially a gene therapy vector. Alternatively, it may be pharmaceutical agent, such as a neurotrophic factor, especially glial cell derived neurotrophic factor (GDNF); an antibody or fragment thereof; an immunosuppressant; an immunomodulator, especially fingolimod; a cytokine, especially an interferon, such as interferon 1 alpha or beta; or an anti-inflammatory. [0013] A gene therapy vector is any vector that may be used to introduce genetic Material into a cell. Gene therapy, as is well known, is the use of genetic material to modulate or add to genes in an individual's cells in order to treat disease. The genetic material to be introduced may be any appropriate genetic material, including DNA and RNA. The genetic material may be used to treat the disease in any known manner, such as gene replacement, gene knockdown, pro-survival gene therapy and cell suicide therapy. [0014] The gene therapy vector may be any vector suitable for administering a gene therapy to a subject, including, for example, viral vectors. Any appropriate viral vector may be used, such as a herpes simplex virus vector, especially HSV-1; an adenovirus vector or a lentivirus vector. It is preferred that the viral vector is a large vector, at least 100 nm in diameter. Further it is preferred that it binds to the heparin binding receptor. [0015] The composition additionally comprises albumin or a functional fragment thereof. As mentioned, the composition may be used for gene therapy. Albumin is included in the composition firstly to open up spaces between cells to enable the therapeutic agents, especially large viral vectors, to move more easily between cells. It also blocks heparin receptors on cells, which are low specificity binding receptors which bind to a variety of proteins, including heparin, albumin and to HSV vectors. By blocking the heparin receptors with albumin, binding of HSV to the receptors is reduced, increasing the proportion of HSV available for transduction. The albumin may be replaced with another heparin receptor binding agent, such as heparin itself, but albumin is preferred. A functional fragment of albumin is a fragment which binds to heparin receptors with at least 75% of the binding efficacy as the full length protein. [0016] The composition preferably further comprises cerebrospinal fluid (CSF), especially artificial cerebrospinal fluid. Artificial cerebrospinal fluid is well known in the art and is a fluid which mimics natural CSF, particularly in terms of its salt contents. Preferably the composition comprises NaCl at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Preferably the composition comprises NaHCO 3 at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Preferably the composition comprises KCl at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Preferably the composition comprises NaH 2 PO 4 at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Preferably the composition comprises MgCl 2 at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Preferably the composition comprises glucose at a similar concentration to that found in natural CSF, that is to say the concentration is preferably within 15%, more preferably within 10% of the concentration in natural CSF. Alternatively, the artificial CSF may omit glucose, so as to reduce the likelihood of bacterial growth in any catheter used to administer the composition to a subject. [0017] The composition may further comprise other active agents. Pharmaceutical compositions of this invention may also comprise any pharmaceutically acceptable carrier, adjuvant or vehicle. Pharmaceutically acceptable carriers, adjuvants and vehicles that may be used in the pharmaceutical compositions include, but are not limited to, ion exchangers, alumina, aluminium stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulphate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat. [0018] The pharmaceutical compositions of this invention may be administered by any appropriate route, but are preferably administered via injection, especially via a neurocatheter, in particular by convection enhanced delivery. The pharmaceutical compositions may contain any conventional non-toxic pharmaceutically-acceptable carriers, adjuvants or vehicles. [0019] The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant such as Ph. Helv or a similar alcohol. [0020] The composition may further comprise a label, enabling the composition to be identified or visualised particularly after administration. Any appropriate label may be used, such as a radioactive label. Such labels are known in the art. [0021] A second aspect of the invention provides the composition of the first aspect for use in therapy. [0022] A third aspect of the invention provides the composition of the first aspect for use in the treatment of a neurological disease. [0023] A fourth aspect of the invention provides a method for treating a neurological disease comprising administering a composition according to the invention to a subject in need thereof. [0024] A fifth aspect of the invention provides a method for improving the transduction of gene therapy vectors, especially into white matter cells, comprising administering albumin or a functional fragment thereof to a subject. The aspect may alternatively provide a method for reducing the therapeutically effective dose of a gene therapy vector, comprising administering albumin or a functional fragment thereof to a subject that is to receive the gene therapy vector. Therapeutically effective dose means the dose required to achieve a particular therapeutic effect, such as transduction of a certain area or number of cells. Reducing the therapeutically effective dose means that a smaller dose may be administered than is required without the administration of albumin. [0025] A sixth aspect of the invention provides a method for improving the infusion of therapeutic agents through white matter, comprising administering albumin or a functional fragment thereof to a subject. [0026] A seventh aspect of the invention provides albumin or a functional fragment thereof for use in the treatment of a neurological disease, especially a disease of the white matter. The albumin may also be for improving the transduction of a gene vector into cells or tissue, especially into white matter, glial or glioma cells. [0027] An eighth aspect of the invention provides a therapeutic agent for use in the treatment of neurological disorder, wherein the therapeutic agent for administration to a subject to which albumin or a functional fragment thereof has been administered or is for simultaneous administration with albumin or a functional fragment thereof. [0028] In the second to eighth aspects, the neurological disease is preferably a disease of the brain or spinal cord, especially a disease of the brain. It may be a cancer, especially a cancer of white matter, in particular a glioma. Alternatively, it may be any other appropriate neurological disease, especially a white matter disease such as multiple sclerosis. [0029] In particular, in the fifth to eighth aspects of the invention, the albumin may be for use in a subject to which a therapeutic agent, especially a gene therapy vector is to be administered. Preferably the therapeutic agent is to be administered prior to, simultaneously with or subsequent to the administration of the albumin. The albumin is preferably for administration immediately prior to or simultaneously with the therapeutic agent. The therapeutic agent is preferably for the treatment of a disease of the brain or spinal cord, especially a disease of the brain. It may be a cancer, especially a cancer of white matter, in particular a glioma. Alternatively, it may be any other appropriate neurological disease, especially a white matter disease such as multiple sclerosis. The therapeutic agent may be gene therapy agent, especially a gene therapy vector. Alternatively, it may be pharmaceutical agent, such as a neurotrophic factor, especially glial cell derived neurotrophic factor (GDNF); an antibody or fragment thereof; an immunosuppressant; an immunomodulator, especially fingolimod; a cytokine, especially an interferon, such as interferon 1 alpha or beta; or an anti-inflammatory. The therapeutic agent, especially a gene therapy vector, is preferably for administration at a different, especially reduced dose compared with the usual therapeutically effective dose. The dose may be altered by reducing the actual dose given, or, when given by infusion, by reducing or increasing the flow rate of the agent, by diluting the infusate or by increasing or decreasing the time period over which the infusion is given. [0030] Preferably the albumin is in isotonic solution, especially in a solution of artificial CSF. The artificial CSF is preferably as defined in the first aspect of the invention. [0031] The subject is preferably a mammal, preferably a primate, especially a human. The subject is preferably suffering from cancer, especially a brain cancer, particularly glioma. [0032] Preferably the compositions, albumin and gene therapy vectors are for administration to the brain, especially by infusion, most preferably via a fine catheter. In particular, the compositions, albumin and gene therapy vectors are for administration by convection enhanced delivery. DETAILED DESCRIPTION OF THE INVENTION [0033] The invention will now be described by way of example only, with reference to the following figures in which: [0034] FIG. 1 shows the pig infusion device. [0035] This device was constructed from a series of zirconia tubes (a). Inside these tubes there was a length of fused silica (outer diameter of 220 μm and an inner diameter of 150 μm) protruding 3 mm from the distal end. This fused silica extended proximally from the rigid cannula through a flexible length of tecothane tubing to the 3-way connector. FIG. 1 b shows the cannula inserted through the stereo-guide of a Pathfinder stereotactic robotic arm, through a small burr-hole and into the brain. FIG. 1 c demonstrates the 3-way connector attached to two glass Hamilton syringes placed in a syringe driver. [0036] FIG. 2 shows Tissue Damage from HSV-1 Infusions. [0037] Representative coronal histological section demonstrating damage in the striatum (left) and white matter (right) following an infusion of HSV-1. Solid white lines represent the trajectory and position of the infusion cannulae. Dotted white lines represent the boundaries between grey and white matter in the rat brain. The cortex lies above the top dotted white line. Below the lower dotted white line are the striata on each side of the lateral ventricles and the midline septum. There are a limited number of EGFP-positive cells in the margins of the damaged tissue. [0038] FIG. 3 shows HSV-1 Vector Distribution in Rat Striatum and White Matter. [0039] Infusions of HSV-1 at a slow-rate (0.5 μl/min), a high-rate (2.50 μl/min), with heparin and following pre-infusion of the tissue with 1% BSA. Number of EGFP-positive cells 0.5 μl/min (p=0.012), 2.4 μl/min (p=0.013) (a) and volume of distribution of EGFP-positive cells 0.5 μl/min (p=0.019), 2.50 μl/min (p=0.011) (b) at 24, 48 and 72 hours. Number of EGFP-positive cells (c) and volume of distribution of EGFP-positive cells (d) at 24, 48 and 72 hours following infusion into the striatum. P values are compared to vector infusions in standard buffer. [0040] FIG. 4 shows Haemorrhage Associated with HSV and Heparin Co-infusion. [0041] Haematoxylin and eosin stained coronal section demonstrating extensive haemorrhage following attempted CED-based co-infusion of HSV-1 and heparin into the striatum of a rat. The parallel dotted white lines represent the trajectory and location of the infusion cannula. [0042] FIG. 5 shows Immune Cell Infiltration into HSV-1 Infused Rat White Matter. [0043] Representative images showing widespread EGFP expression in the white matter (a), ED1-positive microglia (b) and CD8-positive T cell (c) infiltration into the white matter at 48 hours. Note the lack of obvious tissue damage in the white matter (white bars=200 μm). Outlined boxes show higher magnification images of representative areas. The graph demonstrates the rapid increase in ED1 and CD8-positive cell density in the brain following successful distribution of HSV-1 vectors through the white matter (d). [0044] FIG. 6 shows Transductional Tropism of HSV-1 in Rat Corpus Callosum. [0045] Representative images showing EGFP-expressing cells in the white matter (a) immunopositive for GFAP (b) and the colocalisation of EGFP and GFAP (c). EGFP expressing cells in the overlying cortex (d). A minority of transduced cells in the cortex colocalised with NeuN (e) and colocalisation of both EGFP and NeuN (f). The table shows the transductional tropism of HSV-1 in the white matter at 24, 48 and 72 hours (g). [0046] FIG. 7 : HSV-1 Infusions into Pig Corona Radiata (Left hemisphere images). [0047] Images demonstrate EGFP-positive cells throughout the corpus callosum, corona radiata and overlying cortex (a-g). EGFP-positive cells concentrated in the perivascular space around a vessel in the lentiform nucleus (h). [0048] The central section is an unstained coronal histological section along the cannula track. There is a clearly visible haemorrhage at the site of the cannula-tip. T2-weighted coronal MR images (i-k) around the infusion site clearly show evidence of high signal extending through the corona radiata. [0049] FIG. 8 HSV-1 Infusions into Pig Corona Radiata (Right hemisphere images). [0050] The central section is an unstained coronal section along the cannula track. The location of the fused silica tip of the cannula is arrowed. Images 1 to 6 and 8 demonstrate widespread distribution of EGFP-positive cells in the corpus callosum, corona radiata and cortex (a-f, h). Extensive EGFP-positive cells concentrated in the perivascular space of a branch of the lenticulostriate arteries (g). T2-weighted coronal MR images show clear evidence of high signal extending throughout the corona radiata (i-k). (White scale bars represent 200 μm). [0051] FIG. 9 : Transductional Tropism of HSV-1 in Pig Corona Radiata. [0052] Representative images showing EGFP-expressing cells in the pig corona radiata. The majority of these cells colocalised with markers for astrocytes (GFAP) or activated microglia (ED1). Representative photomicrograph of EGFP expressing cells (a), ED1 expressing cells (b) and overlay of EGFP and ED1 (c). Photomicrograph of EGFP expressing cells (d), GFAP (e) and overlay of EGFP and GFAP (f). INTRODUCTION [0053] Malignant gliomas are the most common primary brain tumour and are almost invariably incurable. Critical reasons for this include the highly infiltrative nature of these tumours, intrinsic tumour chemoresistance and the difficulty associated with achieving therapeutic concentrations of chemotherapeutics in the brain without causing toxicity. The direct intraparenchymal administration of oncolytic viral vectors by convection-enhanced delivery (CED) represents a promising new treatment strategy. However there is no evidence to suggest that oncolytic viruses as large as HSV-1 can be administered by CED. In this study, the ability to administer an HSV-1 viral vector have been evaluated in detail in the grey and white matter of both small (rat) and large (pig) animal models. [0054] Infusions of an HSV-1 based vector expressing an EGFP reporter gene were undertaken into the striatum and corpus callosum of rats and the corona radiata of a pig using infusion parameters compatible with CED. The volume of distribution and number of transduced cells following each infusion were determined using stereological methods. Immunohistochemistry was employed to determine the transductional tropism of vectors and to evaluate for the presence of immune cell infiltration into the brain. Strategies to improve vector distribution were evaluated, including using high flow-rate infusions, co-infusing heparin or pre-infusing the tissue with an isotonic albumin solution. [0055] HSV-1 infusions into rat grey and white matter at both slow (0.5 μl/min) and high infusion rates (2.5 μl/min) led to extensive tissue damage and negligible cell transduction. Co-infusion with a low concentration of heparin to minimise non-specific vector binding led to extensive haemorrhage. Pre-infusion of tissue with an isotonic albumin solution facilitated widespread vector distribution and cell transduction in white matter but did not improve vector distribution in grey matter. Using this approach in pig brain led to widespread vector distribution with extensive transduction of astrocytes and activated-microglia with transduced cells in the cortex and perivascular spaces distant to the infusion site. In rat brain, EGFP-expression peaked 48 hours after vector administration and was associated with a vigorous immune response characterised by infiltration of ED1-positive microglia and CD8-positive T cells. [0056] Direct infusions of HSV-1 based viral vectors into the brain leads to minimal vector distribution, negligible cell transduction and extensive damage. Tissue pre-infusion with an isotonic solution prior to vector administration represents a practical and highly effective technique for achieving widespread vector distribution and should be adopted in ongoing and future clinical trials employing HSV-1 based viral vectors. [0057] Methods [0058] Vectors [0059] HSV-1 viral constructs harbouring null mutations in the ICP4 and ICP27 genes, and expressing enhanced green fluorescent protein (EGFP) under the control of a CMV promoter were kindly provided by Biovex. [0060] Vector Infusions [0061] All procedures were carried out in accordance with UK Home Office animal welfare regulations and with appropriate Home Office licences. [0062] Rat Infusion Apparatus and Procedures [0063] Acute infusion cannulae were constructed from lengths of fused silica with an outer diameter of 220 μm and an inner diameter of 150 μm. These lengths of fused silica were connected to 10 μl Hamilton syringes via a connection device made in-house that served to create a seal between the chamber of the Hamilton syringe and the lumen of the fused silica, and which guided the fused silica cannula from the Hamilton syringe, through the dura and into the brain. The Hamilton syringe, with the cannula attached via this connector device, was then mounted in an infusion pump (World Precision Instruments Inc., Sarasota, Fla., USA) attached to a stereotactic frame (Stoelting Co, Wood Dale, Ill. USA) in which rats were immobilised. To insert a cannula, the entire pump/syringe/connector/cannula construct was lowered in the stereotactic frame until the target depth was reached. [0064] Male Wistar rats (B & K, UK) were group-housed and allowed to acclimatize prior to experimental procedures. Male rats weighed 225 to 275 g were anaesthetised with an intraperitoneal dose of ketamine and xylazine and placed in a stereotactic frame (Stoelting Co, Wood Dale, Ill. USA). A linear incision was made between the glabella and the occiput and the skull exposed. Burr holes with a diameter of approximately 2 mm were placed 0.5 mm anterior and 2.75 mm lateral to the bregma and cannulae were inserted to a depth of 5 mm below the dura when the striatum was targeted and to a depth of 2 mm when the corpus callosum was targeted. All cannulae were pre-primed with vector prior to insertion into the brain. Every attempt was made to ensure that no air bubbles were present in the infusion cannula. All vector infusions were of 4 μl at a concentration 1×10 7 pfu/ml. Animals were subdivided into four groups based on the infusion parameters used (Table 1). Heparin co-infusion was achieved by mixing the viral infusate with 2 μl of 5000 IU/ml of heparin (10 IU of heparin). Bovine serum albumin (BSA; Sigma, UK) was mixed in sterile saline. BSA preinfusion of tissue was achieved by infusing 4 μl of isotonic 1% BSA into the striatum and corpus callosum immediately prior to vector infusion. Upon infusion completion, the cannula was left in situ for 5 mins prior to be removed at a rate of 1 mm/min. The wound was then closed with 4/0 vicryl, a dose of intramuscular buprenorphine was administered (30 μg/kg)) and the anaesthetic was reversed with a 0.1 mg/kg intraperitoneal dose of atipamezole hydrochloride (Antisedan; 200 μg/kg; Pfizer, Kent, UK). [0065] Within each group, animals were sacrificed at 24, 48, 72 or 96 hour time-points by perfusion fixation under deep general anaesthetic with 100 mls of phosphate buffered saline followed by 100 mls of 4% paraformaldeyhde (pH 7.4). The brain was then removed from the skull and placed in 4% paraformaldeyhde (pH 7.4) for 48 hours and then cryoprotected in 30% sucrose prior to sectioning. [0066] Pig Infusion Apparatus and Procedures [0067] A male Large White Landrace pig weighing 45 kg was administered an intramuscular dose of ketamine (0.1 mg/kg body weight). General anaesthesia was then induced and maintained with isoflurane (2-5%) and the animals intubated with a cuffed endotracheal tube. Intravenous access was obtained using a cannula placed in an ear vein and normal saline was infused at a rate of 250 ml/hr. [0068] Pig head fixation was achieved using a custom-built fixation device incorporating bilateral MRI-compatible zygomatic screws, a mouldable palate tray and snout-strap. All materials were fully MR-compatible to prevent imaging artefact. Following robust pig head fixation, an arc of fiducials was placed over the animal's head. Flex-L coils were then attached to the lateral aspects of the head and the animal was transferred to a 1.5T MRI scanner (Intera, Phillips). Stereotactic surgical planning and procedures were undertaken using a Pathfinder (Prosurgics, UK) stereotactic robotic arm and associated software. Briefly, this stereotactic arm functioned as follows. The pig was imaged with an array of fiducial balls placed in a fixed location over the animal's head. In theatre, the fiducial balls were replaced with optical reflector balls placed into precisely the same locations. The location of the reflector balls were visualised using a camera in the underside of the robotic arm. The optical reflector balls and MRI fiducials were co-registered automatically by the planning software. The software only allowed visualisation of MR images from a single plane. Consequently as coronal images facilitated the best views of the planned cannula trajectory, they were used for all surgical planning. To conduct the surgical procedure, a range of end-effectors designed to accommodate the burr hole generation and cannula delivery tooling were placed onto the robotic arm. [0069] An acute delivery cannula for vector infusions was developed, which incorporated a fused silica tube (outer diameter of 220 μm and an inner diameter of 150 μm) supported along its distal length by a rigid zirconia tube. To facilitate the preinfusion of tissue with 1% BSA prior to infusing virus, a fused silica-lined 3-way connector was developed so that two syringes could be attached directly to the fused silica tube of the acute cannula ( FIG. 1 ). This ensured that the cannula could be inserted into the corona radiata and then infusions of BSA and virus performed without the need to remove the cannula to reload it with virus. Infusions of 80 μl of vector (1×10 7 pfu/ml) were undertaken into the corona radiata of each hemisphere as follows: [0070] Left Hemisphere: [0071] The cannula was inserted 8 mm short of target and a 1% BSA preinfusion performed at 1 μl/min for 2 mins, 2.5 μl/min for 2 mins and then 5 μl/min for 7 mins (total BSA volume of 42 μl). Vector was then infused at a rate of 5 μl/min for 8 mins (total vector volume of 40 μl). The cannula was then inserted to target and the BSA preinfusion repeated at 1 μl/min for 2 mins, 2.5 μl/min for 2 mins and then 5 μl/min for 4 mins (total BSA volume of 42 μl). Vector was then infused at a rate of 5 μl/min for 8 mins (total vector volume of 40 μl). [0072] Right Hemisphere: [0073] The cannula was inserted to target and a 1% BSA preinfusion performed at 1 μl/min for 2 mins, 2.5 μl/min for 2 mins and then 5 μl/min for 7 mins (total BSA volume of 420). 80 μl of vector was then immediately infused at a rate of 5 μl/min for 16 mins (total vector volume of 80 μl). [0074] Following infusion completion, the cannula was left in place for 10 mins prior to being withdrawn slowly by hand. CSF leakage from the burr hole and cannula track was sealed with Cerebond prior to wound closure. The animals were then transferred back to the MRI scanner and T2-weighted imaging performed to confirm that cannulae had been accurately inserted to target. Animals were recovered for a period of 28 days, before being killed by perfusion fixation under terminal anaesthesia and the brains harvested for histological analysis. [0075] Histology [0076] Rat brains were cut into 35 μm thick coronal sections using a Leica CM1850 cryostat (Leica Microsystems, Germany). Pig brains were cut into 100 μm coronal sections using a Leica SM2500 microtome. Immunohistochemistry was performed on selected sections. Briefly, all solutions for immunohistochemistry were made in phosphate buffered saline (PBS). Free-floating PFA-fixed sections were washed 3 times for 15 minutes in PBS and incubated in 3% hydrogen peroxide to remove endogeneous peroxidise activity. Sections were then washed 3 times for 15 minutes in PBS, before being blocked for 1 hour in blocking solution (10% normal goat or donkey serum) room temperature. Sections were then transferred directly from blocking solution into primary antibody, appropriately diluted in blocking solution, and incubated overnight. The following primary antibodies were used: mouse anti-NeuN (1:300; Chemicon, UK), rabbit anti-GFAP (1:200; Chemicon), mouse anti-ED1 (1:100; Serotec, UK), mouse anti-CD4 (Ox38) (1:300; Serotec, UK) and mouse-anti CD8 (ox 8) (1:300; Serotec, UK. After three PBS washes, sections were then incubated with secondary antibody for at least 2 hrs at room temperature. For fluorescence immunohistochemistry, species-specific secondary antibodies (Cy3) were used (1:200; Jackson Laboratories, CA, USA). After PBS washes, sections were mounted in Vectashield (Vectorlabs, CA, USA) on gelatin-coated slides and coverslipped, prior to fluorescent imaging. [0077] Imaging [0078] Fluorescent imaging was undertaken using a Leica DM5500 microscope (Leica Microsystems, Germany) and digital camera (Microbrightfield, USA). Stereological counts were undertaken on immunostained sections using commercially-available software (Stereoinvestigator, Microbrightfield). Briefly, population estimates were undertaken on representative tissue sections to determine the counting frame size, counting frame number and number and separation of tissue sections necessary to achieve an accurate cell count with a Gundersen (m=1) coefficient of error of less than 0.1. Using these parameters, cell counts were then undertaken on serial sections of a uniform distance apart using the Optical Fractionator probe. The volume of distribution of transduced cells was calculated by tracing contours around the outer margins of the EGFP-expressing cells on each section. Transduced cells outside the striatum were excluded from these contours to ensure that only the intrastriatal volume of distribution of transduced cells was calculated. Infusions that were associated with obvious leakage of vector into the ventricular system were excluded from further analysis. Determination of the vector cell tropism and the density of activated microglia and CD4 and CD8 positive T-lymphocytes in the volume of viral distribution for each infusion was performed on selected tissue sections close to the needle-track using the Fractionator probe. [0079] Statistical Analysis [0080] Tukey's test was used in conjunction with analysis of variance (ANOVA) to determine whether there was a significant difference in vector distribution and cell transduction associated with different infusion parameters. [0081] Results [0082] HSV Infusion into Rat Striatum and White Matter [0083] Infusions of HSV-1 into both the striatum and white matter of rats at a flow-rate of 0.5 μl/min were associated with extensive tissue damage and transduction of a negligible number of cells in close proximity to the infusion site ( FIG. 2 ). In an attempt to improve the volume of distribution and number of transduced cells, infusions were repeated at a higher flow-rate (2.5 μl/min) in order to increase the pressure achieved at the cannula-tip. However, a similar pattern of extensive tissue damage with low levels of cell transduction and poor distribution of virally-transduced cells was observed. [0084] It was hypothesised that the poor distribution of virally-transduced cells and extensive tissue damage associated with HSV infusions were caused by aggregation of viral particles in the tissue immediately around the cannula-tip or due to the comparatively large viral particles (diameter of approximately 250 μm) being forced into the narrow extracellular space. Consequently two strategies were developed to test these hypotheses. In an attempt to minimise extensive viral binding around the cannula-tip, infusions were repeated in a heparin solution. Although there was an increase in the number of transduced cells and the volume of distribution of virally-transduced cells in the presence of heparin compared to infusions of vector (in standard buffer) at 0.5 μl/min and 2.50 μl/min, this was not statistically significant ( FIGS. 3 a and b ). In contrast, preinfusion of white matter with an isotonic solution of 1% bovine serum albumin (BSA), immediately prior to viral infusion led to a significant increase in both the number of cells transduced and the volume of distribution of transduced cells, both of which peaked 48 hours after the infusion ( FIGS. 3 a and b ). Compared to vector infusions (in standard buffer) at 0.50 μl/min and 2.50 μl/min this effect was statistically significant for both the number of transduced cells (p=0.012 and p=0.013 respectively) and the volume of distribution of transduced cells (p=0.019 and p=0.011 respectively). This effect was not observed in the striatum. FIG. 4 shows haemorrhage associated with HSV and Heparin Co-infusion thus rendering this approach clinically unfeasible. [0085] Immune Cell Infiltration into the White Matter Following Successful HSV Infusions [0086] Preinfusion of the white matter with 1% BSA enabled widespread cell transduction without significant infusion-related tissue damage ( FIG. 5 a ). The number of EGFP-positive cells and volume of distribution of EGFP-positive cells peaked at 48 hours. Widespread distribution of HSV-1 viral particles in the white matter did however result in a rapid infiltration of both ED1-positive microglia ( FIG. 5 b ) and CD8-positive T cells ( FIG. 5 c ) which increased between 24 and 72 hours ( FIG. 5 d ). [0087] Transductional Tropism of HSV-1 in the White Matter [0088] Effective HSV-1 distribution in the white matter, following tissue preinfusion with 1% BSA, led to widespread transduction of GFAP-positive astrocytes ( FIGS. 6 a, b and c ). Although not included in the analysis of the number of transduced cells and volume of distribution of transduced cells in the white matter, cells were also transduced in the overlying cortex. Morphologically the majority of these cells were astrocytes although some of these cells colocalised with the neuronal marker NeuN ( FIGS. 6 d, e and f ). The majority of cells transduced in the white matter colocalised with GFAP, although a significant proportion of ED1-positive activated microglia were also transduced (Table in FIG. 6 ). There was no significant difference in the percentage astrocytic or microglial cell transduction between 24 and 72 hours. [0089] Pig Infusions of HSV [0090] Having determined that tissue preinfusion with 1% BSA enabled widespread HSV-1 vector distribution in the white matter of rats, the practicality of this approach was evaluated over much larger volumes of brain in a pig model. Infusion into the left hemisphere was performed at two sites along the catheter trajectory within the corona radiata, whereas in the right hemisphere the entire viral solution was infused at a single site in the corona radiata. The animal was recovered for 2 days and demonstrated no abnormal neurological signs in that time. [0091] On the left side, the proximal infusion was not associated with damage at the cannula-tip. In contrast, the infusion at the distal target site resulted in a small haemorrhage with a diameter of approximately 3 mm. ( FIG. 7 , central panel). In spite of this damage, widespread distribution of EGFP-positive cells was observed through the corona radiata and in distant sites in the frontal cortex, corpus callosum and insula ( FIG. 7 a - g ). Furthermore EGFP-positive cells were seen to be localised in perivascular spaces very distant from the infusion-site, particularly in the vicinity of the lenticulostriate arteries. Excluding EGFP-positive cells confined to perivascular spaces, transduced cells were observed in the brain parenchyma up to 15 mm from the infusion site. T2-weighted coronal MR images ( FIGS. 7 i - k ) around the infusion site clearly show evidence of high signal extending through the corona radiata and, in addition, the haemorrhage area. [0092] The infusion in the right hemisphere was not associated with damage at the cannula tip ( FIG. 8 , central panel). Widespread distribution of EGFP-positive cells was observed in the corona radiata and overlying cortex and as far as the corpus callosum and the cortex of the temporal lobe ( FIG. 8 a - f, h ). As in the left hemisphere, EGFP-positive cells were present in the perivascular spaces around branches of the lenticulostriate arteries ( FIG. 8 g ). [0093] T1-weighted MR images of the infusions showed extensive areas of high-signal in the corona radiata. Histologically, all of the areas of high-signal corresponded with areas of virally-transduced tissue. However, EGFP-expressing cells were also present far beyond the boundaries of regions of high-signal, although it is feasible that the transduction of cells distant to the infusion sites may have resulted from axonal or perivascular transport of infused vector, rather than CED. [0094] FIG. 9 shows the immune response elicited by HSV-1 transduced cells in the pig corona radiata. Transduced cells expressing EGFP co-localised with ED1 ( FIG. 9 a - c ) which shows the presence of CD68-expressing microglia and, in addition, GFAP ( FIG. 9 d - f ). [0095] Discussion [0096] High-grade gliomas are highly infiltrative tumours. Whilst the main tumour mass can often be treated effectively with surgery and/or radiotherapy, destroying the infiltrating tumour cells is technically challenging. For vector-mediated oncolysis to prove efficacious there is an overwhelming requirement to transduce as many tumour cells as possible on initial vector administration. However, as these tumours contain significant areas of necrosis, direct intratumoural vector delivery is unlikely to be effective and is therefore not the focus of this study. This is reflected in the failure of previous clinical trials to demonstrate convincing evidence of efficacy in the treatment of high-grade gliomas (7-9). Indeed, the focus of a more recent study has been to administer replication-selective HSV vectors into the peritumoural tissue (6). As it is possible to achieve widespread vector distribution in the brain by CED it represents the most rational approach for the delivery of oncolytic replication-selective vectors in clinical practice. However, it was questionable whether HSV-based vectors, with a diameter of between 120 and 300 nm (Jacobs et al, 1999) could be infused through the brain extracellular space, which has a diameter of up to 80 nm (Thorne and Nicholson, 2006). In this study, the feasibility of administering a replication-selective HSV-1 vector by CED into normal brain was therefore examined in detail. In spite of the large number of preclinical studies that have involved the direct intracranial administration of HSV-based vectors (17, 18, 20-24, 26-41) remarkably this represents the first published study to evaluate the distribution properties of an HSV-1 vector using appropriate infusion parameters in both grey and white matter, as well as evaluation of strategies to improve vector distribution. [0097] Considering the discrepancy in size between the brain extracellular space and the diameter of HSV-1 particles, it was unsurprising that vector infusions at 0.5 μl/min led to extensive tissue damage in both the grey and white matter and there was minimal penetration of vector into the tissue. In view of this damage, it was hypothesised that an infusion at a higher flow-rate and therefore higher pressure might improve vector distribution by expanding the brain extracellular space. However, similar levels of tissue damage were observed and vector distribution was poor. This tissue damage draws parallels with post-mortem observations made by Rampling et al (2000), who found cystic cavities at the infusion site in the brain of two patients who had HSV1716 injected intratumourally. [0098] Heparan sulphate proteoglycans are known to act as cell surface receptors for HSV-1 (WuDunn and Spier, 1989; Shieh et al, 1992) as well as a number of other viruses including serotype 2 recombinant adeno-associated virus (rAAV2). Indeed co-infusion of heparin has been shown to improve the distribution of rAAV2 in the striatum of adult rats, presumably by competitive antagonism of viral binding to heparan sulphate proteoglycans (Nguyen et al, 2001). Furthermore, Mastakov et al (2002a) demonstrated that heparin co-infusion at concentrations of between 500 and 5000 IU/ml significantly improved the distribution of reporter gene transfer, although higher concentrations were associated with fatal intracerebral haemorrhages. However to date co-infusions of HSV-1 and heparin have not been reported. [0099] In this study, co-infusion of HSV at a concentration of 5000 IU/ml led to a slight increase in the distribution of EGFP expression, although animals did develop clinically undetectable, but extensive intracerebral haemorrhages in both the grey and white matter. In view of the widespread damage associated with infusions of HSV-1 in the absence of heparin, it is unsurprising that the co-infusion of heparin led to this extensive bleeding. As such this approach is unlikely to be of significant value in clinical practice. [0100] A number of studies have evaluated the CED-based distribution properties of nanoparticles of a similar size to HSV-1. Chen et al (2005) and MacKay et al (2005) demonstrated that polystyrene nanoparticles and liposomes with a diameter of 200 nm only penetrated short distances into the striatum of rats. Interestingly however, Chen et al (2005) demonstrated that coating the nanoparticles with albumin to shield the hydrophobic particle surface significantly improved their distribution. Furthermore, Neeves et al (2007) demonstrated that preinfusing the striatum with isotonic saline significantly improved the distribution of 53 nm diameter polystyrene nanoparticles in the striatum of rats. This effect was greater than was observed with pre-infusion of hyaluronidase to degrade the brain extracellular matrix, or hyperosmotic mannitol to osmotically expand the extracellular space. [0101] In this study, the use of albumin pre-treatment to shield non-specific binding and achieve isotonic expansion of the brain extracellular space were amalgamated to facilitate the administration of a replication-selective HSV-1 vector. This approach facilitated the widespread distribution of vector in the white matter of rat and pig brain, although it was unsuccessful in the grey matter of rats. Nevertheless, these results clearly demonstrate that with appropriate tissue preinfusion, very widespread vector distribution is possible within the white matter. The main advantage of using a pig model was that these animals have a large gyrencephalic brain that is larger that that of many primates and can accommodate large volume infusions with drug-delivery cannulae of a scale that can be translated directly into human studies. Indeed it is our intention to utilise this cannula system in future clinical trials. [0102] The ability to distribute HSV in white matter and not grey matter probably relates to the greater elasticity of white matter and subsequently its greater capacity to accommodate an infused volume (Bobo et al, 1994). Indeed the microstructural orientation of myelinated axons has been shown to be preserved via oligodendroglial processes in the presence of experimentally induced dilatation of the brain extracellular space (Marmarou et al, 1980). As a consequence, whilst pre-infusion of white matter with an isotonic albumin solution enables widespread vector distribution, it may not be feasible to use this approach to adequately target tumour cells that have arisen within or infiltrated into grey matter structures. Interestingly however, there was clear evidence of transduced cells in the cortex of pigs following vector infusion into the corona radiata. In view of the inability of HSV to distribute through grey matter in rat brain, it seems likely that cortical cell transduction occurred by axonal or perivascular transport of vector from the infusion site. As it seems unlikely that HSV could efficiently transduce myelinated axons in the white matter and in view of the observed distribution of transduced cells in the perivascular spaces, the latter of these two mechanisms seems most likely. [0103] Successful distribution of vector within the white matter resulted in a brisk immune response characterised by a rapid infiltration of activated microglia and CD8-positive T cells. However, there is some evidence that ED1 is also a marker for neutrophils in ischaemic and traumatic brain injuries (41) and therefore the true identity of these infiltrating cells may merit further examination. In the context of treating brain tumours, the induction of an anti-HSV CD8 response may have the added benefit of enhancing the tumour cell kill (Todo et al, 1999). However, although no animals developed detectable neurological deficits, the long-term consequences of widespread distribution and cell transduction with HSV-1 vectors within the brain and the resultant vigorous immune response requires careful evaluation. This necessity is emphasised by the potential for significant vector escape from the relatively immune-privileged brain and into the systemic circulation with the subsequent development of an adaptive immune response. Realistically this could be mediated through tissue damage associated with cannula implantation, infusion-related damage or drainage of vector along the perivascular spaces. This is particularly significant as although antigen-presenting dendritic cells are not present in the uninflammed brain, dendritic cells are present in the perivascular space and CSF, into which the perivascular space drains (McMahon et al, 2006). [0104] The potential risks of viral vector leakage into the CSF and the development of an immune response emphasise the importance of visualising vector distribution clinically. As such, a number of T1 and T2 contrast agents have been developed to act as surrogate markers of vector distribution (Szerlip et al, 2007; Fiandaca et al, 2008). However co-infusion of vector with a surrogate marker adds significant complexity and regulatory hurdles to the clinical administration of gene therapy vectors to the brain. In this study T2-weighted MR imaging was undertaken in an attempt to visualise infusion-related oedema. These images clearly demonstrated an area of high-signal in the vicinity of the infusions, which histologically corresponded with the location of transduced cells in the white matter, although cell transduction clearly extended beyond the margins of this high-signal. However, in view of the apparent perivascular and possible axonal transport of vector augmenting the distribution achieved directly by CED, it is highly unlikely that the use of surrogate markers or MR imaging would offer a realistic prediction of the final distribution of HSV vector-mediated transduced cells. [0105] In summary, evidence from this study suggests that HSV-1 vectors are too large to be efficiently distributed by CED unless the target tissue is pre-infused to dilate the brain extracellular space. This finding has critical implications in interpreting the results of clinical trials involving the use of HSV-based viral vectors to treat patients with brain tumours. Indeed this data suggests that the infusion methods employed in these trials would have probably led to negligible vector distribution. Utilising this finding in future clinical trials however has the potential to improve patient outcome by maximising the number of transduced tumour cells and therefore maximise to possibility of treatment efficacy. REFERENCES [0000] Bobo R. H., Laske D. W., Akbasak A., Morrison P. F., Dedrick R. L., Oldfield E. H. (1994). Convection-enhanced delivery of macromolecules in the brain. Proc Nat Acad Sci, USA., 91(6): 2076-80. Bowers W. J., Olschowska J. A., Federoff H. J. (2003). Immune responses to replication-defective HSV-1 type vectors within the CNS: implications for gene therapy. Gene Ther 10: 94105. Canoll P., Goldman J. E. (2008). The interface between glial progenitors and gliomas. Acta Neuropathol., 116: 465-77. Chen M. Y., Hoffer A., Morrison P. F., Hamilton J. F., Hughes J., Schlageter K. S., Lee J., Kelly B. R., Oldfield E. H. (2005). Surface properties, more than size, limiting convective distribution of virus-sized particles and viruses in the central nervous system. J Neurosurg., 103(2): 311-9. Dempsey M. F., Wyper D., Owens J., Pimlott S., Papanastassiou V., Patterson J., Hadley D. M., Nicol A., Rampling R., Brown S. M. (2006). Assessment of 123I-FIAU imaging of herpes simplex viral gene expression in the treatment of glioma. Nucl Med. Comm., 27(8): 611-7. Fiandaca M. S. Varenika V., Eberling J., McKnight T., Bringas J., Pivirotto P., Beyer J., Hadaczek P, Bowers W., Park J., Federoff H., Forsayeth J., Bankiewicz K. S. (2009). Real-time MR imaging of adeno-associated viral vector delivery to the primate brain. Neuroimage, 47 Suppl 2:T27-35. Harrow S., Papanastassiou V., Harland J., Mabbs R., Petty R., Fraser M., Hadley D., Patterson J., Brown S. M., Rampling R. (2004). HSV1716 injection into the brain adjacent to tumour following surgical resection of high-grade glioma: safety data and long-term survival. Gene Therapy, 11: 1648-58. He B., Gross M., Roizman B. (1997). The γ 1 34.5 protein of herpes simplex virus 1 complexes with protein phosphatise 1γ to dephosphorylate the γ subunit of the eukaryotic translation initiation factor 2 and preclude the shutoff of protein synthesis by double-stranded RNA-activated protein kinase. PNAS. 94: 843-8. Hess C. F., Schaaf J. C., Kortmann R. D, Schabet M., Bamberg M. (1994). Malignant glioma: patterns of failure following individually tailored limited volume irradiation. Radiother Oncol., 30:146-9. Jacobs A., Breakefield X. O., Fraefel C. (1999). HSV-1 based vectors for gene therapy of neurological diseases and brain tumours: part II. Vector systems and applications. Neoplasia, 1(5): 402-16. Louis D. N. (2006). Molecular pathology of malignant gliomas. Ann Rev Pathol Mech Dis., 1:97-117. Mackay J. A., Deen D. F., Szoka F. C. (2005). Distribution in brain of liposomes after convection enhanced delivery: modulation by particle charge, particle diameter, and presence of steric coating. Brain Res., 103: 139-53. Markert J. M., Medlock M. D., Rabkin S. D., Gillespie G. Y., Todo T., Hunter W. D., Palmer C. A., Feigenbaum F., Tornatore C., Tufaro F., Martuzo R. L. (2000). Conditionally replicating herpes simplex virus mutant, G207 for the treatment of malignant glioma: results of a phase 1 trial. Gene Therapy, 7: 867-74. Marmarou A., Takagi H., Shulman K. (1980) in Brain Edema , Eds. Cervos-Navarro J., and Ferszt R. (Raven, New York). 28; 345-58. Mastakov M. Y., Baer K., Kotin R. M., During M. J. (2002). Recombinant adeno-associated virus serotypes 2- and 5-mediated gene transfer in the mammalian brain: Quantitative analysis of heparin co-infusion. Mol. Ther. 5(4); 371-380. McMahon E. J., Bailey S. L., Miller S. D. (2006). CNS dendritic cells: Critical participants in CNS inflammation? Neurochem Int., 49(2): 195-203. Morrison P. F., Laske D. W., Bobo H., Oldfield E. H., Dedrick R. L. (1994). High-flow microinfusion: tissue penetration and pharmacodynamics. Am J. Physiol., 35: 8292-305. Neeves K. B., Sawyer A. J., Foley C. P., Saltzman W. M., Olbricht W. L. (2007). Dilation and degradation of the brain extracellular matrix enhances penetration of infused polymer nanoparticles. Brain Res., 1180: 121-32. Nguyen J. B., Sanchez-Pernaute R., Cunningham J., Bankiewicz K S. (2001). Convection-enhanced delivery of AAV-2 combined with heparin increases TK gene transfer in the rat brain. Neuroreport, 12(9): 1961-4. Papanastassiou V., Rampling R., Fraser M., Petty R., Hadley D., Nicoll J., Harland J., Mabbs R., Brown M. (2002). The potential for efficacy of the modified (ICP34.5′) herpes simplex virus HSV 1716 following intratumoural injection into human malignant glioma: a proof of principal study. Gene Therapy, 9: 398-406. Rampling R., Cruickshank G., Papanastassiou V., Nicoll J., Hadley D., Brennan D., Petty R., MacLean A., Harland J., McKie E., Mabbs R., Brown M. (2000). Toxicity evaluation of replication-competent herpes simplex virus (ICP34.5 null mutant 1716) in patients with recurrent malignant glioma. Gene Therapy, 7(10): 859-66. Shah A. C., Benos D., Gillespie G. Y., Markert J. M. (2003). Oncolytic viruses: clinical application as vectors for the treatment of malignant gliomas. J Neuroncol., 65: 203-26. Shieh M. T., WuDunn D., Montogmery R. I., Esko J. D., Spear P. G. (1992). Cell surface receptors for herpes simplex virus are heparan sulfate proteoglycans. J. Cell Biol., 116: 1273-81. Szerlip N. J., Walbridge S., Yang L., Morrison P. F., Degen J. W., Jarrell S. T., Kouri J., Kerr P. B., Kotin R., Oldfield E. H., Lonser R. R. (2007). Real-time imaging of convection-enhanced delivery of viruses and viral-sized particles. J Neurosurg., 107(3): 568-77. Thorne R. G., Nicholson C. (2006). In vivo diffusion analysis with quantum dots and dextrans predicts the width of brain extracellular space. Proc Natl Acad Sci USA., 105(24): 8416-21. Todo T., Rabkin S. D., Sundaresan P., Wu A., Meehan K. R., Herscowitz H. B., Martuza R. L. (1999). Systemic antitumor immunity in experimental brain tumor therapy using a multimutated, replication-competent herpes simplex virus. Hum Gene Ther. 10(17): 2741-55. World Health Organization Classification of Tumours of the Nervous System, Editorial and Consensus Conference Working Group (2007). Louis, D N, Ohgaki, H, Wiestler, OD, Cavenee, WK (Eds), IARC Press, Lyon, France. Wrensch M., Minn Y., Chew T., Bondy M., Berger M. S. (2002). Epidemiology of primary brain tumours: Current concepts and review of the literature. Neuro Oncol., 4(4): 278-99. WuDunn D. and Spier P. G. (1989). Initial interaction of herpes simplex virus with cells is binding to heparan sulfate. J. Virol. 63; 52-8. [0000] TABLE 1 Summary of HSV-1 Rat Infusions Recovery Flow-Rate Time Number Group (□l/min) (hours) Co-infusion 2 Low-Flow 0.5 24 2 48 2 72 2 High-Flow 2.5 24 2 48 2 72 2 Heparin 0.5 24 10 units of 2 48 heparin 2 72 3 BSA- 0.5 24 Infusion site 3 Preinfused 48 preinfused with 3 72 1% BSA

The invention relates to a composition comprising albumin and a therapeutic agent, particularly a gene therapy vector. The composition is useful in the treatment of glioma.

BACKGROUND OF THE INVENTION [0001] Field of the Invention [0002] The invention is in the field of medical technology and is directed to a method and a device for repairing a human or animal joint, in particular a small synovial joint such as a human facet joint, a joint of the human hand or foot (including finger and toe joints), a sacroiliac joint, sternoclavicular joint, sternocostal articulation or a costovertebral joint, but also cartilaginous joints, in particular intervertebral joints. The expression “repairing a joint” is used herein in the sense of surgery concerning both articular surfaces of the joint by introducing a device in the joint and fastening it to both articular surfaces, wherein after the surgery, the joint will be capable of at least restricted articulation, i.e. the repair is not a so called joint fusion (no articulation capability after surgery) but it is e.g. a joint resurfacing (approximately full articulation capability maintained or restored). [0003] Description of Related Art [0004] The publication U.S. Pat. No. 5,571,191 (Fitz) discloses methods and devices for resurfacing human facet joints, wherein the device comprises two independent cap-like components to be fastened to the articular processes of the joint in two successive surgical steps, each one of the components constituting an artificial articular surface. WO 2008/034276 also discloses a method and a device for such resurfacing. For the surgery as proposed in both named cases, it is necessary to make the articular surfaces of the joint to be treated accessible either by dislocating or luxating the joint or by largely resecting the joint capsule and the related ligaments. [0005] The publication US-2009/171394 (Abdou) discloses methods and devices for surgically treating human facet joints by providing in each one of the articular surfaces un undercut groove, the grooves being located opposite one another, and by introducing through a cannula a device into the grooves, wherein cannula and device have cross sections adapted to the pair of opposite undercut grooves. The device is initially retained in the grooves by a press fit, followed by osseointegration. The device comprises two device parts, of which one fits into each one of the pair of opposite undercut grooves. The device parts are separate from each other or they are connected to each other either rigidly or through an elastomeric portion. Depending on the choice of the type of device, after such surgery, the treated joint will allow full articulation (separate device parts), limited articulation (elastomeric connection between the device parts) or no articulation (rigidly connected device parts), i.e. joint fusion. [0006] The publication WO2010/045749 (WW Technology), which is enclosed herein in its entirety by reference, describes devices and methods for fusing a small synovial joint in a human or animal patient, in particular a human facet joint, by introducing between the suitably prepared articular surfaces of the joint a fusion device and by anchoring the fusion device in both articular surfaces by in situ liquefaction of a material having thermoplastic properties and being suitably arranged on the fusion device, and by letting the liquefied material penetrate into bone tissue of the articular surfaces, where on re-solidification it constitutes a positive fit connection between the fusion device and the bone tissue. For the in situ liquefaction, application of vibrational energy (in particular ultrasonic vibration) to the fusion device is preferred and for restricting the liquefaction to desired locations and therewith preventing undue thermal load in tissue near the surgical site, thermoplastic materials (and preferably other materials comprised by the device) are chosen to be capable of vibration energy transmission with little loss (no inner liquefaction) such limiting liquefaction to interfaces between a vibrating element (device or device part) and a counter element (bone tissue or further device part), which interfaces are situated at locations where liquefaction and penetration is desired. BRIEF SUMMARY OF THE INVENTION [0007] It is the object of the invention to provide a method and a device for repairing a joint in human or animal patients, in particular a small synovial joint such as e.g. a human facet joint, or a cartilaginous joint such as e.g. a human intervertebral joint, wherein the repaired joint is to be capable of limited to full articulation after the repair operation, wherein both articular surfaces of the joint are to be treated simultaneously, and wherein the repair is to comprise introduction of a device between the suitably prepared articular surfaces and fixation of device portions in either one of these surfaces in one only surgical step, and with the aid of a material having thermoplastic properties and being liquefied in situ by application of vibratory energy. [0008] These and other objects are achieved by the invention as defined in the claims. [0009] As stated above in connection with the state of the art, targeted in situ liquefaction of a material having thermoplastic properties with the aid of vibratory energy for anchoring a device in hard tissue (in most cases bone tissue but also including suitable bone replacement material) can be achieved without undue thermal load on tissue of the surgical site, if the device is designed for being capable of transmitting vibratory energy with as little loss as possible from a proximal face contacted with a vibration tool to the site of desired liquefaction, i.e. to an interface between the vibrating device or a part thereof and a counter element (bone tissue or further device part). Such efficient energy transmission is achieved in the case of desired liquefaction at interfaces between device and hard tissue by designing the device to be a single rigid vibrator and by vibrating the whole device, and in the case of desired liquefaction between two device parts by designing the device to comprise two rigid parts, by vibrating one of the rigid parts and keeping the other part from being vibrated also. This requirement contrasts with the requirement of at least limited articulation of the joint after treatment, which necessitates two device parts to be able to articulate against each other, i.e. forbids a rigid connection therebetween. [0010] The above named two contrasting requirements are reconciled according to the invention by designing the device for repairing the human or animal joint to comprise two articulating portions which are able to be articulated and possibly translated relative to each other and further equipping the device with a temporal connector portion which rigidly connects, at least for the time of the implantation, the two articulating portions. [0011] In a first preferred group of embodiments, the device according to the invention comprises two articulating portions, a resilient interface portion arranged between the articulating portions and fixed to each one of the articulating portions, and, as temporal connector portion, a spreader being removably clamped between the articulating portions by the resilient force of the interface portion. The clamped spreader renders the device or part thereof rigid for the implantation procedure and is removed immediately after implantation of the device, or in a follow-up surgical procedure after an initial healing phase, in which the joint is immobilized by the spreader, or it is removed gradually by bio-resorption or bio-degradation. The interface portion remains in the joint for limiting articulation or is gradually removed by bio-resorption or bio-degradation after a first or second healing phase in which articulation of the joint is to be limited by the interface portion. [0012] In a second group of exemplary embodiments, the device according to the invention comprises two articulating portions and, as temporal connector portion, a clamp which is capable to clamp the two articulating portions together such connecting them to form one rigid element. The device may further comprise an interface portion arranged between the articulating portions, wherein the interface portion is resilient and fixed or not fixed to the articulating portions, or is rigid and not fixed to the articulating portions, i.e. allowing articulation and/or translation of the articulating portions relative to each other. The clamp and possibly the interface portion is removed or bio-resorbed or bio-degraded as discussed for the first preferred group of embodiments. [0013] In a third group of exemplary embodiments, the device according to the invention comprises two articulating portions and a rigid connector portion consisting of a bio-resorbable or bio-degradable material and being arranged between the two articulating portions and rigidly fixed to either one of the latter, the connector portion comprising a bio-resorbable or bio-degradable material. The connector portion is removed from between the articulating surfaces by bio-resorption or bio-degradation in a healing phase after the implantation, wherein during this healing phase initial immobilization of the joint by the connector portion gradually decreases to eventually leave the articulating portions independent of each other, i.e. with no limitation of the articulating capability of the joint or with such limitation as constituted by the form of the articulating surfaces of the articulating portions. Alternatively, the initially rigid connector portion may only partially be removed by bio-resorption or bio-degradation leaving a resilient or flexible interface portion between the articulating portions as discussed above for the first or second group of embodiments of the device according to the invention. [0014] All embodiments of the device according to the invention constitute at least just before and in particular during the implantation procedure one piece which is pushed between the two articulating surfaces of the joint to be repaired. This means that for the implantation the named articulating surfaces need not to be made accessible by widely opening or dislocating the joint and are therefore particularly suitable for minimally invasive surgery. The fact that the device according to the invention is anchored in the articulating surfaces of the joint where cortical and cancellous bone are usually well developed and still does not need direct access to the articulating surfaces by opening the joint, makes lateral approach to hinge joints, in particular to small hinge joints such as e.g. interphalangeal and metacarpophalangeal joints in the human hand, not only possible but also advantageous. [0015] As stated above, each one of the two articulating portions of the device according to the invention is anchored in bone tissue of one of the two suitably prepared articulating surfaces of the joint to be treated, with the aid of a material having thermoplastic properties and vibration energy or possibly in bone replacement material arranged at the articulating surfaces of the joint. Therein the vibration energy is transmitted to the device or to a part thereof from a proximal face and liquefaction is achieved at an interface between the device and bone tissue (or replacement material) of the two articulating surfaces of the joint or at interfaces between device parts, the latter interfaces being located near bone tissue (or replacement material) of the two articulating surfaces of the joint. [0016] The basis of the named anchoring technique is the in situ liquefaction of a thermoplastic material having mechanical properties suitable for a mechanically satisfactory anchorage of an implant in hard tissue (e.g. bone tissue or corresponding replacement material), wherein the material in its liquefied state has a viscosity which enables it to penetrate into natural or beforehand provided pores, cavities or other structures of the hard tissue, and wherein an only relatively small amount of the material is liquefied such that a non-acceptable thermal load on the tissue is prevented. When re-solidified, the thermoplastic material which has penetrated into the pores, cavities or other structures constitutes a positive fit connection with the hard tissue. [0017] Suitable liquefaction combined with an acceptable thermal loading of the tissue and suitable mechanical properties of the positive fit connection is achievable by using materials with thermoplastic properties having initially a modulus of elasticity of at least 0.5 GPa and a melting temperature of up to about 350° C. and by providing such material e.g. on an implant surface, which on implantation is pressed against the hard tissue, preferably by introducing the implant into an opening (e.g. bore) which is slightly smaller than the implant or by expanding the implant in an opening which originally is slightly larger than the implant (expansion e.g. by mechanically compressing or buckling of the implant). For anchoring the implant in the hard tissue, the implant is subjected to vibration of a frequency preferably in the range of between 2 and 200 kHz (preferably ultrasonic vibration) by applying e.g. the sonotrode of an ultrasonic device to the implant. Due to the relatively high modulus of elasticity the thermoplastic material is able to transmit the ultrasonic vibration with such little damping that inner liquefaction and thus destabilization of the implant does not occur, i.e. liquefaction occurs only where the thermoplastic material is in contact with the bone tissue and is therewith easily controllable and can be kept to a minimum. [0018] Instead of providing the material having thermoplastic properties on the surface of the implant (disclosed e.g. in U.S. Pat. No. 7,335,205 or U.S. Pat. No. 7,008,226), it is possible also to provide the material having thermoplastic properties in a perforated sheath and to liquefy it within the sheath and press it through sheath perforations to the surface of the implant and into the pores or cavities of the hard tissue (disclosed e.g. in U.S. Pat. No. 7,335,205 and U.S. Pat. No. 7,008,226) and/or it is possible to liquefy the material having thermoplastic properties between two implant parts of which one is vibrated and the other one serves as counter element, the interface between the two implant parts being positioned as near as possible to the hard tissue (as disclosed in the publications US 2009/131947 and WO2009/109057). [0019] Materials having thermoplastic properties suitable for the device and the method according to the invention are thermoplastic polymers, e.g.: resorbable polymers such as polymers based on lactic and/or glycolic acid (PLA, PLLA, PGA, PLGA etc.) or polyhydroxy alkanoates (PHA), polycaprolactone (PCL), polysaccharides, polydioxanes (PD) polyanhydrides, polypeptides or corresponding copolymers or composite materials containing the named polymers as a component; or non-resorbable polymers such as polyolefines (e.g. polyethylene), polyacrylates, polymetacrylates, polycarbonates, polyam ides, polyester, polyurethanes, polysulfones, polyarylketones, polyimides, polyphenylsulfides or liquid crystal polymers LCPs, polyacetales, halogenated polymers, in particular halogenated polyolefines, polyphenylensulfides, polysulfones, polyethers or equivalent copolymers or composite materials containing the named polymers as a component. [0020] Specific embodiments of degradable materials are Polylactides like LR706 PLDLLA 70/30, R208 PLDLA 50/50, L210S, and PLLA 100% L, all of BOhringer. A list of suitable degradable polymer materials can also be found in: Erich Wintermantel und Suk-Woo Haa, “Medizinaltechnik mit biokompatiblen Materialien und Verfahren”, 3. Auflage, Springer, Berlin 2002 (in the following referred to as “Wintermantel”), page 200; for information on PGA and PLA see pages 202 ff., on PCL see page 207, on PHB/PHV copolymers page 206; on polydioxanone PDS page 209. Discussion of a further bioresorbable material can for example be found in CA Bailey et al., J Hand Surg [Br] 2006 April; 31(2):208-12. [0021] Specific embodiments of non-degradable materials are: Polyetherketone (PEEK Optima, Grades 450 and 150, Invibio Ltd), Polyetherimide, Polyamide 12, Polyamide 11, Polyamide 6, Polyamide 66, Polycarbonate, Polymethylmethacrylate, Polyoxymethylene, or polycarbonateurethane (in particular Bionate by DSM, in particular type 65D and 75D). An overview table of polymers and applications is listed in Wintermantel, page 150; specific examples can be found in Wintermantel page 161 ff. (PE, Hostalen Gur 812, HOchst AG), pages 164 ff. (PET) 169ff. (PA, namely PA 6 and PA 66), 171 ff. (PTFE), 173 ff. (PMMA), 180 (PUR, see table), 186 ff. (PEEK), 189 ff. (PSU), 191 ff (POM—Polyacetal, tradenames Delrin, Tenac, has also been used in endoprostheses by Protec). [0022] The material having thermoplastic properties may further contain foreign phases or compounds serving further functions. In particular, the thermoplastic material may be strengthened by admixed fibers or whiskers (e.g. of calcium phosphate ceramics or glasses) and such represent a composite material. The material having thermoplastic properties may further contain components which expand or dissolve (create pores) in situ (e.g. polyesters, polysaccharides, hydrogels, sodium phosphates), compounds which render the immplant opaque and therewith visible for X-ray, or compounds to be released in situ and having a therapeutic effect, e.g. promotion of healing and regeneration (e.g. growth factors, antibiotics, inflammation inhibitors or buffers such as sodium phosphate or calcium carbonate against adverse effects of acidic decomposition). If the thermoplastic material is resorbable, release of such compounds is delayed. [0023] Fillers used may include degradable, osseostimulative fillers to be used in degradable polymers, including: β-Tricalciumphosphate (TCP), Hydroxyapatite (HA, <90% crystallinity); or mixtures of TCP, HA, DHCP, Bioglasses (see Wintermantel). Osseo-integration stimulating fillers that are only partially or hardly degradable, for non degradable polymers include: Bioglasses, Hydroxyapatite (>90% cristallinity), HAPEX®, see SM Rea et al., J Mater Sci Mater Med. 2004 September; 15(9):997-1005; for hydroxyapatite see also L. Fang et al., Biomaterials 2006 July; 27(20):3701-7, M. Huang et al., J Mater Sci Mater Med 2003 July; 14(7):655-60, and W. Bonfield and E. Tanner, Materials World 1997 January; 5 no. 1:18-20. Embodiments of bioactive fillers and their discussion can for example be found in X. Huang and X. Miao, J Biomater App. 2007 April; 21(4):351-74), JA Juhasz et al. Biomaterials, 2004 March; 25(6):949-55. Particulate filler types include: coarse type: 5-20 μm (contents, preferentially 10-25% by volume), sub-micron (nanofillers as from precipitation, preferentially plate like aspect ratio >10, 10-50 nm, contents 0.5 to 5% by volume). [0024] Specific examples of bio-degradable filled polymer material are PLLA filled with tricalciumphosphate or PDLLA 70%/30% (70% L and 30% D/L, LR706 by BOhringer) filled with up to 30% biphasic calciumphosphate. [0025] Portions of the implantable device or device part which do not serve the anchoring function may consist of any suitable material (e.g. polymer, metal, ceramic, glass) which material may be bio-resorbable, bio-degradable or not and may have thermoplastic properties or not. Where such materials are to be in contact with bone tissue they preferably have surfaces equipped for furthering osseointegration, i.e. with per se known surface structures and/or coatings. [0026] The devices and methods according to the invention are in particular suitable for minimally invasive surgery but are also applicable in open surgery. BRIEF DESCRIPTION OF THE DRAWINGS [0027] The invention is described in further detail in connection with the appended Figs., wherein: [0028] FIGS. 1 to 5 show an example of the first preferred group of embodiments of the device according to the invention, the device comprising two articulating portions, a resilient interface portion and a temporal connector portion in the form of a spreader; [0029] FIG. 1 is a partially exploded perspective view of the complete device; [0030] FIG. 2 is a sectional elevation view taken along section II-II of FIG. 1 perpendicular to implantation direction; [0031] FIG. 3 is a sectional plan view taken along section III-Ill of FIG. 1 ; [0032] FIG. 4 is a sectional elevation view taken along section IV-IV of FIG. 1 parallel to implantation direction; [0033] FIG. 5 is a perspective view of the spreader; [0034] FIG. 6 is a perspective view of a further exemplary embodiment of the first preferred group, illustrated without showing the connector portion; [0035] FIG. 7 is a perspective view of a further exemplary embodiment of the first preferred group, illustrated without showing the connector portion; [0036] FIG. 8 is a perspective view that shows a further embodiment of a resilient interface portion applicable e.g. in the devices as illustrated in FIGS. 1 to 7 ; [0037] FIG. 9 is an elevation view that shows an example of the second group of embodiments of the device according to the invention, the device comprising two articulating portions, an interface portion and a connector portion in form of a clamp (viewed parallel to the implantation direction); [0038] FIG. 10 is a perspective view that shows the connector portion or clamp of the device according to FIG. 9 ; [0039] FIG. 11 is an elevation view that shows a further example of the second group of embodiments of the device according to the invention, the device comprising two articulating portions and a connector portion in form of a clamp (viewed parallel to the implantation direction); [0040] FIG. 12 is a perspective view that shows the connector portion or clamp of the device according to FIG. 11 ; [0041] FIG. 13 is a perspective view that shows an example of the third group of embodiments of the device according to the invention, the device comprising two articulating portions being rigidly connected by a rigid and bio-degradable connector portion; and [0042] FIG. 14 is a sectional elevation view that illustrates a further example of the first group of embodiments of the device according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0043] FIGS. 1 to 5 show an example of the first, preferred group of embodiments of the device according to the invention. The device comprises two articulating portions 1 and 2 , a resilient interface portion 3 and a connector portion 4 in the form of a spreader. FIG. 1 is a three dimensional representation of the complete device and further shows a distal end of a vibration tool 5 used for implanting the device. FIGS. 2, 3 and 4 are sections through the complete device ( FIG. 2 : section line II-II perpendicular to the implantation direction ID, FIGS. 2 and 3 : section lines III-Ill and IV-IV parallel to the implantation direction ID, the section lines being indicated in FIG. 1 ). FIG. 5 is a three dimensional representation of the connector portion only. [0044] The articulating portions 1 and 2 face against each other with their inner sides (articulating surfaces of the articulating portions) and comprise on their outer sides the material having thermoplastic properties, e.g. in the form of protruding ridges 10 extending parallel to the implantation direction ID, wherein the protruding ridges 10 of the material having thermoplastic properties may be fixed in an undercut groove (not shown) or on a rough or porous surface portion of a carrier plate 11 being made of a different material (e.g. metal or ceramic material) and, on their surfaces facing the bone tissue, may carry energy directors in the form of edges or small peaks protruding from a main surface. It is possible also to manufacture the whole articulating portions 1 and 2 of the material having thermoplastic properties. [0045] The resilient interface portion 3 is arranged between the two articulating portions 1 and 2 and is fixed to the inner sides thereof, i.e. to the surface of the carrier plate 11 opposite to its surface carrying the ridges 10 . The interface portion 3 is capable of being compressed and stretched in particular in a direction perpendicular to the inner sides of the articulating portions 1 and 2 or between the carrier plates 11 respectively, thereby not only changing the distance between these carrier plates but possibly also an angle therebetween. The interface portion 3 may also be deformable such that it allows limited translation between the two articulation portions 1 and 2 or the two carrier plates 11 respectively. The interface portion 3 is e.g. an elastomeric construct (e.g. made of an elastomer or liquid or gas filled container having resilient walls). [0046] The connector portion 4 is designed for being positioned between the articulating portions 1 and 2 or the carrier plates 11 respectively and has a height between the carrier plates 11 which is large enough for stretching the interface portion 3 such that forces normally occurring during handling and implantation of the device are not able to spread the articulating portions further, i.e. to release the connector element 4 from being clamped between the carrier plates 11 by the resilient force of the interface portion 3 . The connector portion 4 has preferably the form of a U surrounding the interface portion 3 on a proximal side and both lateral sides. The central member of the U-shaped connector portion preferably comprises means for attaching the distal end or a vibration tool 5 to it, e.g. a bore 12 into which a protrusion 13 arranged on this distal tool end (e.g. thread or press fit connection). Alternatively, the named attachment means are e.g. a protrusion on the connector portion 4 and a corresponding bore on the tool 5 , or a corresponding pair of cone and tapering bore. The attachment means are designed to be capable of transmitting the vibrations of the tool 5 into the connector portion 4 and to stand not only the compressive force during implantation but also the tensile load on pulling the connector portion 4 away from the implanted rest of the device (articulating portions 1 and 2 and interface portion 3 ) after the anchoring step. [0047] For facilitating the removal of the connector portion 4 on completion of the anchoring step, it is advised to provide surfaces of the connector portion 4 , at least where in contact with the articulating portions 1 and 2 , of materials which are not prone to fretting or ceasing on removal of the connector portion (relative movement with high friction due to pressure). For carrier plates 11 of titanium it is therefore proposed to use for the connector portion 4 or the corresponding surface thereof a different metal, e.g. stainless steel or aluminum, or to coat with e.g. PEEK such surfaces of a less suitable material (e.g. same metal as articulating portions, e.g. titanium). [0048] The vibration tool 5 has a distal face, which is preferably adapted in form and size to the proximal face of the connector portion 4 , and a proximal end which is connected or connectable to a vibration source (e.g. ultrasonic device, possibly with booster). [0049] Implantation of the device according to FIGS. 1 to 5 in a joint, e.g. a human facet joint) comprises the following steps: The articular surfaces of the joint are prepared by exposing the subchondral bone of the articular surfaces at least where the material having thermoplastic properties is to be liquefied and to penetrate the bone tissue. The joint is e.g. fixed in a distracted or non-distracted configuration and two bores (two pairs of opposite grooves one in each articular surface of the joint) are drilled in a direction about parallel to the articular surfaces, the bores being dimensioned to be slightly smaller than the ridges 10 of the device. Further areas of the articular surfaces, e.g. to be in contact with the carrier plates 11 may be decorticated to enhance osseointegration with the preferably correspondingly equipped outer surfaces of the carrier plates 11 . The device comprising the two articulating portions 1 and 2 , the interface portion 3 and the connector portion 4 clamped between the articulating portions is mounted to the distal end of the vibration tool 5 and the proximal end of the vibration tool is connected with the vibration source. The device is positioned with its distal end in or at the entrance to the gap between the prepared articulating surfaces of the still fixed joint, the ridges of the material having thermoplastic properties being aligned with the bores or grooves in the articulating surfaces respectively. The device is pushed into the gap between the two articular surfaces and simultaneously the vibration tool is vibrated, such advancing the device into the gap, liquefying the material having thermoplastic properties at least where it is in pressing contact with the bone tissue and letting the liquefied material penetrate the bone tissue. The vibration source is switched off and the liquefied material is allowed to re-solidify, while the pressing force is preferably maintained. The vibration tool 5 together with the connector portion 4 is pulled away from the joint wherein it may be advantageous to release fixation of the joint and to lightly distract the implanted articular portions using a suitable distraction tool and/or to counteract the pulling force with a suitable tool acting on the proximal faces of the articulating portions 1 and 2 . [0056] Fixation of the joint during at least the step of implanting and anchoring the device in the joint is preferred, such that neither the forcing of the device into the joint nor the liquefied material being pressed into the bone tissue of the articular surfaces can change the relative position of the articulating surfaces of the joint during the implantation. Such fixation of the joint is e.g. achieved by positioning a distal face of a cannulated guide tool against the bone surface of the implantation site, wherein sharp protrusions provided on this distal face are forced into the bone surface on either side of the pair of articular surfaces. Therein the axial channel of the guide tool is preferably not only adapted for guiding the device to the joint and into the joint but also to instruments used for locating and preparing the joint for the implantation, i.e. to instruments such as e.g. a joint finder whose distal end, for locating the joint, is forced between the articular surfaces of the joint to be repaired, a drill and/or a cutting tool (or possibly a drill guide or cutting tool guide) for preparing the articular surfaces. This means that the guide tool is fixed on the bone surface in one of the first steps of the implantation procedure and is removed in one of the last steps, therebetween serving for fixing the joint and for guiding the tools necessary for the surgery. [0057] The whole implantation method is preferably carried out in a minimally invasive manner, i.e. with the aid of a cannula or with the aid of the above mentioned guide tool through which the device and all necessary tools are guided to the implantation site. A set of tools which is suitable for the method is disclosed in the publication WO-2010/045749 (WW Technology). However, use of the device and the method according to the invention is possible also in open surgery. [0058] The device and the implantation method described above in connection with FIGS. 1 to 5 can be varied without departing from the basic idea of the invention e.g. in the following manner, wherein the listed variations may be combined with each other in various ways: The interface portion 3 has the shape of a round disk and the connector portion 4 the shape of a half circle. The interface portion 3 has a different thickness on either side of a middle line extending parallel to the implantation direction, i.e. the two articulating portions 1 and 2 are angled relative to each other. The interface portion has anisotropic deformation qualities by being made of an anisotropic material, e.g. by comprising a matrix material which is filled in an anisotropic manner, by comprising a matrix material in which an anisotropic structure of a stiffer material in integrated, or by comprising an anisotropic pattern of pores or cavities (see also FIG. 8 ). The interface portion 3 comprises two or more than two sections and the connector portion 4 extends between the these sections instead of around one only interface portion 3 . The articulating surfaces of the articulating portions 1 and 2 are not even but e.g. curved, wherein the curvature of one articulating surface may be different from the curvature of the other articulating surface. The articulating surface of one articulating portion is larger than the articulating surface of the other articulating portion. Instead of comprising two or more than two ridges 10 of the material having thermoplastic properties, each articulating portion 1 or 2 comprises a complete or partial coating of the material having thermoplastic properties and no grooves are provided in the articulating surfaces of the joint. Depending on the character of the bone tissue in which the device is to be anchored it may not be necessary to remove bone tissue for providing the grooves for accommodation of the ridges 10 , wherein in such a case the ridges may be equipped e.g. with sharp edges oriented parallel to the implantation direction for grooving the bone tissue by compressing or displacing it. The distal face of the vibration tool 5 is adapted for transmission of the vibration not only to the connector portion 4 but in addition or alternatively to the proximal faces of the articulating portions 1 and 2 . The connector portion 4 is made of a bio-resorbable or bio-degradable material and is not removed after implantation but gradually resorbed or degraded. In such a case it is not necessary that the connector portion 4 extends to the proximal face of the device and the vibration may be coupled into the device through the proximal faces of the articulating portions 1 and 2 , which are preferably mounted on the vibration tool 5 in a similar manner as described for the connector portion 4 . The connector portion 4 is not connected to the vibration tool and comprises means for being gripped with a corresponding removal tool. The connector portion 4 is not removed immediately after implantation of the device but in a second surgical operation, wherein a removal tool may be connected to the connector portion 4 in the same way as the vibration tool 5 is connected to it for implantation. Instead of the ridges 10 consisting of the material having thermoplastic properties and being integral parts of the articulating portions 1 and 2 , the articulating portions 1 and 2 comprise perforated sheaths or tunnels into which pins of the material having thermoplastic properties are pushed while being vibrated (see FIG. 13 ). In such a case, it is not the whole device which as vibrated but only part thereof, namely the pins, and liquefaction of the material having thermoplastic properties is achieved between the vibrating pins and the rigid rest of the device at interfaces inside the perforated sheaths or tunnels to flow through the perforation into the neighboring bone tissue, wherein the rest of the device made rigid by the connector portion and positioned between the articulating surfaces of the joint is prevented from vibrating together with the pins. There need to be at least two pins of the thermoplastic material, one for each articulating portion, preferably four, wherein all these pins may be vibrated in succession or simultaneously using a corresponding forked vibration tool. Instead of the ridges 10 consisting of the material having thermoplastic properties and being attached to the carrier plates 11 , the device comprises separate pins of the material having thermoplastic properties and the carrier plates comprise corresponding grooves to be placed opposite the grooves provided in the articular surfaces of the joint (see e.g. FIG. 7 ). For anchoring the pins simultaneously in the bone tissue and in the carrier plate, the pins are pushed while being vibrated between articular surface and carrier plate of the device positioned between the articular surfaces of the joint. Also in this case, the rigidity of the device caused by the connector portion 4 keeps the device firmly in the joint while the pins are positioned and anchored and prevents loss of energy through vibration of device portions other than the pins. [0073] One skilled in the art will easily adapt suitable ones of the above listed variations of the exemplary embodiment of the device according to FIGS. 1 to 5 for further embodiments of the device according to the invention as illustrated in the further Figs. and as described below in connection with these further Figs. [0074] FIGS. 6 and 7 show in more detail two further examples of the first, preferred group of embodiments of the device according to the invention. Each one of the two illustrated devices comprise two articulating portions 1 and 2 and a resilient interface portion 3 positioned between the two articulating portions and attached thereto. The connector portion is not shown in FIGS. 6 and 7 but is supposed to be of a similar shape as shown in FIGS. 1 to 5 . [0075] The device according to FIG. 6 is very similar to the one according to FIGS. 1 to 5 , wherein the ridges 10 of the material having thermoplastic properties are illustrated with energy directors in the form of longitudinally protruding small ridges or edges 15 extending along part of the ridge length and being offset relative to each other in the direction of this length. [0076] The device according to FIG. 7 comprises instead of ridges 10 , pins 20 of the material having thermoplastic properties which are accommodated in grooves 21 on the outer surface of the carrier plates 11 and protruding from these grooves. The same as the ridges 10 shown in FIG. 6 , the pins 20 are equipped with edges 15 running along part of the pin length and being arranged offset to each other along the pin length. The pins 20 are either fixed in the grooves 21 as stated above and implantation of the device is carried out as described above for the device according to FIGS. 1 to 5 . Alternatively, the pins 20 are separate device parts and for implantation, the device without the pins is first positioned between the articular surfaces of the joint to be treated, wherein each groove 21 on the outer side of a carrier plate 11 is facing a groove in the prepared articulating surface of the joint. Then a pin is pushed into every opening formed by one of the grooves in the articular surface of the joint and an opposite groove 21 in the carrier plate 11 , while being vibrated for liquefaction of the material having thermoplastic properties to be liquefied where in contact with the bone tissue on the one side and with the material of the carrier plate 11 on the other side and to thereby be anchored on both sides. [0077] The carrier plates 11 shown in FIG. 7 consist e.g. of titanium and have a structured or rough outer surface suitable for furthering osseointegration. Such osseointegration may replace the anchorage of the device in the bone tissue of the joint via the material having thermoplastic properties such that the pins 20 may consist of a bio-resorbable or bio-degradable material. [0078] FIG. 8 shows an example of a resilient interface portion 3 which is e.g. suitable for the devices as illustrated in FIGS. 1 to 7 . The interface portion 3 comprises bores 22 with substantially parallel axes (or other cavities or pores arranged in parallel rows or other arrangements with one principal direction). This interface portion 3 has anisotropic characteristics, as mentioned further above, in that it offers less resistance to shear and bending forces acting in planes oriented perpendicular to the bore axes than to shear and bending forces acting in planes oriented parallel to the bore axes. With such equipped interface portions it becomes possible to mimic physiologically the range of motion and motion restraints towards the extremata of joint movement. [0079] FIGS. 9 and 10 illustrate an example of a second group of embodiments of the device according to the invention. The device comprises two articulating portions 1 and 2 with e.g. ridges 10 of the material having thermoplastic properties and with a carrier plate 11 , and it further comprises an interface portion 3 arranged between the articulating surfaces of the articulating portions 1 and 2 , and a connector portion 4 in the form of a clamp. FIG. 9 shows the complete device viewed parallel to the implantation direction, FIG. 10 shows the connector portion 4 only. In contrast to the first group of embodiments of the device according to the invention, in the devices of the second group the articulating portions 1 and 2 are clamped together by the connector portion 4 instead of being spread apart. This means that the interface portion 3 may be rigid and not attached to either one of the articulating portions or it may be resilient and attached to both articulating portions or not. [0080] The articulating portions 1 and 2 of the device according to FIG. 9 have concave inner sides and the interface portion 3 constitutes a separate item in the form of a free flattened sphere of a resilient or non-resilient material accommodated between these concave inner sides. This specific form of the articulating surfaces of the articulating portions 1 and 2 and of the interface portion 3 are not a condition for the second group of embodiments of the device according to the invention. These forms may also correspond to any form illustrated in the previous figures or described in the exemplary variations listed above for the device according to FIGS. 1 to 5 . [0081] The temporal connector portion 4 of the device according to FIGS. 9 and 10 is U-shaped with a central member 31 and two leg members 32 attached to the central member, the members of the connector portion 4 being dimensioned for the leg members 32 to fit in grooves 30 running parallel to the ridges 10 on the outer side of the carrier plates 11 and they are further dimensioned to exert a pressing force on the pair of the articulating portions 1 and 2 . As discussed further above, the central member 31 of the connector portion 4 is preferably equipped for being connected to a distal end of a vibration tool, e.g. with a bore 12 . As discussed further above, the temporal connector portion 4 is removed after the step of anchoring the articulating portions 1 and 2 in the bone tissue of the articulating surfaces of the joint by pulling the connector portion away from the joint, wherein it may be advantageous to press the articulating portions 1 and 2 against each other and/or to counteract the pulling by pressing the articulating portions 1 and 2 into the joint. [0082] FIGS. 11 and 12 illustrate a further example of the second group of embodiments of the device according to the invention. FIG. 11 shows the complete device comprising two articulating portions 1 and 2 , no interface portion and a temporal connector portion 4 clamping the two articulating portions against each other; FIG. 12 shows the connector portion 4 only. This connector portion 4 of the present embodiment comprises a central member 31 and in this case four leg members 32 , which fit into bores 33 extending parallel to the implantation direction, two in each one of the articulating portions 1 and 2 and which are dimensioned and equipped for exerting a pressing force biasing the two articulating portions 1 and 2 against each other. Implantation and removal of the connector portion 4 are carried out as discussed for the previously described devices. [0083] FIG. 13 shows an example of the third group of embodiments of the device according to the invention. This device comprises again two articulating portions 1 and 2 and a temporal connector portion 4 which connects the two articulating portions 1 and 2 rigidly by being rigid itself and by being rigidly connected to either one of the articulating portions 1 and 2 . The connector portion 4 is arranged between the articulating surfaces of the articulation portions 1 and 2 and is made of a quickly bio-resorbable or bio-degradable or water-soluble material and therefore does not need to be removed by the surgeon. The device according to FIG. 13 comprises two bores 12 for being releasably connected with a vibration tool. [0084] For initial blocking of joint movement e.g. for healing associated soft tissue damage and/or hard tissue fractures (possible additional damages which may be caused by the same trauma as the joint damages to be repaired in the manner presently discussed) it may be advantageous to use for the connector portion 4 a material capable of maintaining its rigidity for a longer time (preferably for 2 to 8 weeks). Polymers suitable for such prolonged but still temporal joint blocking or such longer term connector portion respectively are e.g. copolymers of lactic and glycolic acid or collagen based polymers, which are water soluble or bio-degradeable depending on their degree of cross-linking. [0085] Apart from the bio-resorbable or bio-degradable material the connector portion 4 may further comprise non-resobable or non-degradable regions (not shown) which constitute a potential interface portion in the form of a resilient or flexible connection between the articulating portion 1 and 2 which limits articulation and possibly translation between the articulating portions once the resorbable or degradable part of the connector portion 4 is resorbed or degraded. [0086] FIG. 14 shows a section (similar to FIG. 3 ) through a further example of the first group of embodiments of the device according to the invention. As already mentioned further above, in this embodiment the material having thermoplastic properties is present in the form of a plurality of thermoplastic pins 40 which fit into perforated (or fenestrated) sheaths 41 or tunnels, which are arranged parallel to the implantation direction on the outer surface of the carrier plates 11 and protruding from the latter, or which are arranged in the carrier plates and not protruding from them. In FIG. 14 the thermoplastic pins are illustrated positioned inside the perforated sheaths 41 . The perforations of the sheaths or tunnels are located on the outer side of the articulating portions 1 and 2 and are dimensioned such that the liquefied material of the thermoplastic pins 40 is capable of flowing unhindered to the outside of the sheathes 41 or tunnels for being capable of penetrating into the bone tissue of the articulating surfaces of the joint to be treated. [0087] On implantation, the device according to FIG. 14 is positioned, with or without the pins 40 inside the sheaths 41 , between the articulating surfaces of the joint to be treated. Then the pins 40 are pushed into the sheaths or tunnels while being vibrated. The pin material is liquefied on the interface between the pin and the inside surface of the sheath 41 or tunnel, in particular in locations where either one of the named inside wall or the pin comprises energy directors, and flows through the perforations to penetrate adjacent bone tissue. For targeted liquefaction, the named energy directors are preferably arranged on the inside surface of the sheath or tunnel in the region of the perforations. [0088] The implantation of the device as shown in FIG. 14 is carried out much the same as described above for the device as shown in FIG. 6 and comprising separate pins 20 . [0089] Of course it is possible also to equip embodiments of the second and third group of embodiments of the device according to the invention with sheaths or tunnels as shown in FIG. 14 and implanting them with the method as described above for the device according to FIG. 14 .

A human or animal joint is treated by introduction of a device between the suitably prepared articulating surfaces of the joint, and the device is anchored in both these articular surfaces with a material having thermoplastic properties. For allowing at least limited articulation of the joint after implantation, the device includes two articulating portions, wherein one of the articulating portions is anchored in each articulating surfaces of the joint. On implantation a proximal face of the device is contacted with a vibrating tool and the vibration is transmitted through parts of the device to locations in which the material having thermoplastic properties is near the bone tissue of the articulating surfaces of the joint and in which liquefaction is desired. The liquefied material penetrates the bone tissue and, on re-solidification forms a positive fit connection between the device and the bone tissue

CROSS REFERENCE [0001] This application is a continuation of Utility application Ser. No. 10/944,606, filed Sep. 17, 2004, which claims priority of Provisional Ser. No. 60/504,242, filed Sep. 18, 2003. FIELD OF THE INVENTION [0002] This invention relates to credit monitoring and screening and, more particularly, to a credit approval monitoring system and method. BACKGROUND OF THE INVENTION [0003] Simply stated, credit is borrowed money. Credit signifies the amount of trust a creditor has in the fact that a debtor will repay borrowed funds pursuant to an agreement. The amount of trust a creditor has directly translates into the amount of money that will be provided to the customer and which must be repaid. [0004] To facilitate credit transactions, a credit bureau acts as a clearinghouse for credit history information. Credit grantors provide credit bureaus with factual information on how their credit customers pay their bills. Credit grantors can obtain credit reports about consumers who wish to open accounts with them. [0005] Recently, credit bureaus have provided services to consumers allowing the consumer to monitor changes to their personal credit information. These monitoring systems can provide notices any time a change is made to the consumer's credit report to ensure that the credit information used by the credit bureau is accurate and up to date. Moreover, the information can be used by the consumer to ascertain the likelihood of obtaining credit. However, the consumer will not know if the changes are sufficient to allow them to obtain credit without actually applying for the same. [0006] Only businesses or individuals with a permissible purpose can access a consumer's credit report. An example of a permissible purpose includes accessing a credit report in connection with a credit transaction involving the consumer. Because of these restrictions, a credit grantor cannot on its own access credit information to determine the credit worthiness of any particular consumer. [0007] The present invention is directed to enhancements in current systems and method for managing relationships between credit grantors and consumers. SUMMARY OF THE INVENTION [0008] In accordance with the invention there is provided a credit approval monitoring system and method. [0009] There is disclosed in accordance with one aspect of the invention, a credit approval monitoring method comprising: continually monitoring a credit report of a consumer; notifying the consumer when any changes are made to the consumer's credit report; periodically screening the credit report to determine if the consumer satisfies select criteria of a credit grantor; and notifying the consumer if the screening determines that the consumer satisfies the select criteria. [0010] It is a feature of the invention that periodically screening the credit report to determine if the consumer satisfies select criteria of a credit grantor comprises screening the consumer after the consumer has been denied credit. [0011] It is another feature of the invention that periodically screening the credit report to determine if the consumer satisfies select criteria of a credit grantor comprises making a daily determination that the consumer satisfies the select criteria. [0012] It is still a further feature of the invention that notifying the consumer if the screening determines that the consumer satisfies the select criteria comprises transmitting an email message to the consumer including a link to a network site providing a marketing message to the consumer. [0013] It is still another feature of the invention that the consumer is directed to a network site of the credit grantor if the consumer responds to the marketing message. [0014] It is yet another feature of the invention that periodically screening the credit report to determine if the consumer satisfies select criteria of a credit grantor comprises determining a credit score for the consumer and comparing the credit score to the select criteria. [0015] There is disclosed in accordance with another aspect of the invention a credit approval monitoring method comprising: providing a notification of adverse action to a credit applicant responsive to the credit applicant not satisfying select criteria; subsequent to the adverse action notification monitoring a credit report of the credit applicant; periodically screening the credit report to determine if the credit applicant satisfies the select criteria; and notifying the credit applicant if the screening determines that the credit report satisfies the select criteria. [0016] There is disclosed in accordance with yet another aspect of the invention a credit approval monitoring system. The system comprises a database system storing credit files for consumers. A monitoring processing system monitors credit reports of subscribing consumers and transmits messages indicative of changes in a subscribers credit report. A screening processing system screens credit reports to determine if credit applicants satisfy select criteria. A watch processing system is operatively associated with the monitoring processing system and the screening processing system for periodically requesting the screening processing system to determine if the credit report of a select consumer satisfies the select criteria and sending the determination to the monitoring processing system to notify the select consumer if the screening processing system determines that the credit report of the select consumer satisfies the select criteria. [0017] Further features and advantages of the invention will be apparent from the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a block diagram of a credit approval monitoring system in accordance with the invention; [0019] FIG. 2 is a flow diagram illustrating a sale cycle and set up routine of a credit approval monitoring method in accordance with the invention implemented using the system of FIG. 1 ; [0020] FIG. 3 is a flow diagram illustrating a credit monitoring routine for the credit approval monitoring method in accordance with the invention; [0021] FIG. 4 is a flow diagram illustrating a wait routine of the credit approval monitoring method in accordance with the invention; and [0022] FIG. 5 is a flow diagram illustrating an e-mail routine of the credit approval monitoring method in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION [0023] In accordance with the invention, a credit approval monitoring system and method provides a gateway for businesses to market credit related products to consumers by using combined information, architecture and technology of credit monitoring products and decisioning or screening products that analyze a consumer's credit file using credit attributes and the like. [0024] Conventional credit monitoring products facilitate consumer analysis of changes to their personal credit information. Likewise, current decisioning products provide a pre-screen tool that facilitates the cross sell of credit products and services. The credit approval monitoring system and method in accordance with the invention combines and enhances these two products for businesses to use in managing consumer relationships. The system and method provides a new product relationship with a consumer by matching consumers who participate in a credit monitoring service with offers from businesses when changes in the consumer's credit profile meets criteria pre-defined by the business. Particularly, the credit approval monitoring system and method supports promoting credit monitoring services to businesses for consumer usage. The system and method develops the e-commerce capabilities targeting directly to consumers and to manage and grow consumer relationships while allowing promotion of credit monitoring to businesses. [0025] As a consumer's credit profile changes, credit monitoring services continue to inform the consumer. In accordance with the invention decisioning or screening services evaluate opportunities to present the consumer with marketing offers from the business responsible for the use of the credit monitoring service. These marketing offers are packaged and displayed when the consumer returns to the credit monitoring service to check status. [0026] Referring to FIG. 1 , a block diagram illustrates an exemplary system for implementing the credit approval monitoring system and method. A cloud 10 represents a communication network for providing electronic communications. The network 10 may comprise any available network such as a telephone network, the internet, or any other means of providing electronic communications. Connected to the network 10 are a consumer PC 12 , a business customer host 14 and a credit approval monitoring system 16 . The credit approval monitoring system 16 comprises a credit monitoring system 18 , a credit screening system 20 and a credit watch system 22 , each connected to the network 10 . Also, the credit watch system is operatively connected to the credit monitoring system 18 and the credit screening system 20 . Particularly, the credit monitoring system 18 is also a stand alone product, as described above, which facilitates consumer analysis of changes to personal credit information and uses a monitor database 24 . The credit screening system 20 also operates as a stand alone product, as a pre-screen tool that facilitate the sale of credit products and services. This credit screening system 20 uses a screening database 26 . The credit watch system 22 functions with the credit monitoring system 18 and the credit screening system 20 , as discussed above, and uses a general credit database 28 that stores credit history information for consumers, as discussed above. [0027] As is apparent, FIG. 1 is illustrative of an environment in which the credit approval monitoring system 16 can be implemented. However, the invention is not intended to be limited to any particular hardware implementation. Each block may represent a computer processing system or systems or a network of computer processing systems, servers, or the like, as necessary to implement the invention. The blocks are intended to represent functionality implemented using one or more conventional processing systems, as will be apparent to those skilled in the art. [0028] FIGS. 2-5 comprise flow diagrams illustrating routines for a credit approval monitoring method in accordance with the invention implemented using the exemplary credit approval monitoring system 16 of FIG. 1 . The process is described with reference to the exemplary system of FIG. 1 . However, as is apparent, the particular process steps could be implemented in different functional blocks from those described herein. [0029] Referring initially to FIG. 2 , the process begins when a business customer enters into a contract with a credit bureau at a block 30 to purchase the credit approval monitoring service. At a block 32 , the credit bureau and the business customer determine the particular methodology to be used for that business customer. This methodology may include the decisioning criteria used for determining credit worthiness. Additionally, the methodology includes the content of credit offers in the form of marketing messages that will be shown to consumers when an approval change is identified and a destination landing page URL to be sent to consumers when they respond to the business customer's marketing message. The URL is hosted by the business customer, for example in the host 14 , see FIG. 1 . [0030] At a block 34 , the business approved criteria is set up and stored in the screening database 26 . The credit monitoring system 18 uses static sub-codes for data pulls. A new sub-code is created to identify the credit monitoring system 18 and the particular rules for the business customer. The credit database 28 is set up with the new sub-code at a block 36 . This allows the credit monitoring system 18 , see FIG. 1 , to pull data from the credit database 28 using this special sub-code. The credit monitoring system 18 adds the new sub-code to a newly created sub-code table at a block 38 . The new sub-code is used by the credit monitoring system 18 on behalf of a specific business customer whenever data is pulled. The marketing message content is also loaded into the monitor database 24 for later retrieval. The credit monitoring system 18 communicates to the business customer at a block 40 the URL used in adverse action notices to consumers. This URL allows the credit monitoring system 18 to identify which business customer, and thus which sub-codes, to reference for decisioning purposes. The set up process concludes at a block 42 when the business customer is prepared to begin mailing adverse action notices and the methodology proceeds to a credit monitoring routine flow diagram of FIG. 3 . [0031] Referring to FIG. 3 , the credit monitoring routine is illustrated beginning at a block 44 entered from the flow diagram of FIG. 2 . The process begins at a block 46 when the business customer communicates adverse action information to consumers in the form of credit applicants. Advantageously, only applicants who are defined as “gray-area declination” consumers, will receive a letter with the credit monitoring URL messaging. These are applicants the business customer deems close enough that a future positive migration in credit may be enough to receive an approval based on the decisioning criteria set up in the credit monitoring system 18 . At a block 48 , the consumer, using a computer, such as the consumer PC 12 , see FIG. 1 , responds to the messaging and visits the landing page defined by the URL in the adverse action notice. The business customer ID is captured and the credit monitoring system 18 begins to track the business customer ID. If the consumer elects not to subscribe to any credit monitoring services on the website, then the entire process ends. If the consumer purchases credit monitoring, at a block 50 , then they fill out appropriate order information and a set up process as defined by the credit monitoring system 18 and this information is stored in the monitor database 24 . Once the service is successfully ordered, then the credit monitoring system 18 sends watch data to the watch system 22 using a dynamic sub-code for each entry. Particularly, the consumer information and the business customer specific sub-code, discussed above, are transmitted on a normal schedule at a block 52 . The watch system 22 receives the watch data at a block 54 for processing. The credit monitoring routine then ends when the watch service is successfully set up and the process proceeds via a block 56 to a wait routine illustrated in FIG. 4 . [0032] Referring to FIG. 4 , the wait routine is illustrated beginning at a block 58 defining an entry point from the credit monitoring routine of FIG. 3 . The wait routine begins when the watch system 22 processes information based on criteria established for a given business customer sub-code. A watch database 59 , as described herein, watches a consumers credit file and takes other actions when certain conditions occur. The actions include notifying the consumer, as is conventional, and/or notifying the business customer. At a block 60 , the watch system 22 executes periodically, for example nightly, using the business customer subscriber sub-code and sends to the screening system 20 screening indicative and permanent ID data and score data for each consumer being monitored. This information is accepted by the screening system 20 at a block 62 which sends a request to and receives credit information from the credit database 28 . Using criteria in the screening database 26 , the screening system 20 renders a credit decision at a block 64 and communicates the decision back to the block 60 . Also, from a block 66 a soft inquiry is posted to the consumer credit profile in the credit database 28 . [0033] The credit monitoring system 18 periodically receives results from the watch system 22 and the screening system 20 , from the blocks 59 and 60 , at a block 68 . The results include a reasons code for decisions. For each credit monitoring customer for which the credit monitoring system 18 receives a yes decision from the credit screening, as determined at a decision block 70 , the consumer profile will be flagged at a block 72 to display the business consumer marketing message which is sent to the monitor database 24 . The process ends when the credit approval monitoring system e-mails to consumers at a block 74 with change or no change notifications using the existing credit monitoring system 18 . [0034] Referring to FIG. 5 , a flow diagram illustrates the e-mail routine implemented after the wait routine of FIG. 4 at a block 76 . The routine begins when the consumer responds to a received change notification e-mail and visits the designated credit monitoring URL website at a block 78 . At the website, the consumer logs in at a block 80 and views the standard credit monitoring page, using information from the monitor database 24 . If the customer profile has been flagged, as discussed above, and as determined at a decision block 82 , then the credit monitoring system 18 displays the business customer marketing message at a block 84 with links to the business customer. If the business customer profile was not flagged, then the routine ends at a node 86 . If the consumer who is shown the marketing message at the block 84 elects to click on the indicated link, then the consumer will be redirected to the previously identified business customer URL site at a block 88 . The consumer decision to transfer to the business customer website is recorded in a reporting system at a block 90 and the consumer is then redirected to the business customer website at a block 92 . The routine then ends at the block 86 when the consumer leaves the credit monitoring system website. [0035] Thus, in accordance with the invention, the integrated credit approval monitoring system 16 allows business customers to convert previously declined consumers. Consumers can view and respond to pre-approval messages when a change threshold is realized. Also, the potential consumer is more inclined to review the marketing position given the relationship between their personal information change and the relevance of the message. Additionally, the system 16 allows grey-area declination consumers to improve their financial condition. Consumers will be able to order credit related products easily through established business client relationships. This adds value to the proposition of resale of monitoring products to consumers by business clients. Finally, the credit approval monitoring system and method leverages existing products in an integrated credit approval monitoring system and method. [0036] The present invention has been described with respect to flowcharts and block diagrams. It will be understood that each block of the flowchart and block diagrams can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions which execute on the processor create means for implementing the functions specified in the blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer implemented process such that the instructions which execute on the processor provide steps for implementing the functions specified in the blocks. Accordingly, the illustrations support combinations of means for performing a specified function and combinations of steps for performing the specified functions. It will also be understood that each block and combination of blocks can be implemented by special purpose hardware-based systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.

A credit approval monitoring system comprises a database system storing credit files for consumers. A monitoring processing system monitors credit reports of subscribing consumers and transmits messages indicative of changes in a subscribers credit report. A screening processing system screens credit reports to determine if credit applicants satisfy select criteria. A watch processing system is operatively associated with the monitoring processing system and the screening processing system for periodically requesting the screening processing system to determine if the credit report of a select consumer satisfies the select criteria and sending the determination to the monitoring processing system to notify the select consumer if the screening processing system determines that the credit report of the select consumer satisfies the select criteria.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional application of co-pending application Ser. No. 11/605,869, filed on Nov. 29, 2006, which is a continuation-in-part of application Ser. No. 11/355,908, filed on Feb. 16, 2006, (now abandoned) which is a continuation-in-part of application Ser. No. 10/913,819, filed on Aug. 6, 2004 (now U.S. Pat. No. 7,057,156), which in turn claims priority under 35 U.S.C. §119(e) from provisional patent application Ser. No. 60/494,977, filed on Aug. 14, 2003. This application also claims priority under 35 U.S.C. §119(e) from provisional patent application 60/740,850 filed on Nov. 30, 2005. FIELD OF THE INVENTION The present invention relates to a miniaturized integrated spectral sensor, with integrated sensed signal conditioning, signal exchange, and integration into a handheld device for the measurement of solution and solvent-based chemistries. With adaptation, the device can be configured for solids or gases, but liquids are the preferred implementation. The sensed information is converted into meaningful information in the form of concentrations of specified species and for the composition or properties of mixtures and composite materials. BACKGROUND OF THE INVENTION In a traditional laboratory, instruments described as spectrometers, spectrophotometers or photometers (referred to from here on as spectrometers) are used to make measurements on liquids or solutions containing one or more chemical substances. Such methods of analysis are used to measure the concentration of a component either directly or following the reaction with one or more chemical substances, usually described as reagents. In such reactions the analyte, or material being measured, is converted into a chemical form that can be detected within the spectral region covered by the instrument. Examples can include the formation of a specific color, or the formation of a material that provides a characteristic fluorescence or luminescence, especially in the presence of radiation of specific wavelengths, such as an ultraviolet source, or the formation of a light scattering medium, where the degree of light scatter is proportional to the concentration of the analyte (substance or species being measured). This latter case includes turbidity for the measurement of suspended materials. In certain spectral regions, such as the ultraviolet, near infrared and the mid infrared, materials can have natural absorption characteristics, where the material can be measured directly in the absence of a reagent. Similar situations occur where an analyte is naturally colored or naturally fluorescent. In these situations reagents are not required. The normal procedure in a laboratory is to prepare the sample for analysis. The circumstances described in the preceding paragraph above are for the measurement of samples in a liquid form. Spectral measurements are not limited to liquids, and samples that exist as solids or gases can be considered for spectroscopic analysis if prepared in a form that can be measured. For most applications involving reagents, a liquid-based medium is implied. Both solids and gases can be handled if dissolved within a reagent system, or if dissolved in a suitable solvent. If the sample has its own natural spectral response, in the absence of a reagent, the sample may be studied in its natural form as a solid or gas. Such measurements require some form of specialized sample handling accessory. Samples existing in the liquid state are often preferred for reasons of convenience of sampling and handling, and because the sample as studied is generally homogenous and representative of the whole sample. The standard approach to handling liquids is to place the sample with a container with optically transparent walls or windows. Such containers are called a cells or cuvettes (referred to from here on as cells). If the sample must be treated with a reagent prior to analysis then the sample is normally placed in a separate container, such as a laboratory flask or bottle, prior to placement within the cell. Such a preparation can also require heating or an incubation period. Once the sample is transferred into the measurement cell, the cell is placed at a sampling point within the spectrometer. Typically, this sampling point is a chamber or sampling compartment, which is often light-tight, and can be sealed from interference from ambient light. The sampling chamber may be configured to accept one or more sampling cells. In an alternative rendering, the sample cell may be configured for sample flow through the cell. In such systems, a reagent may be introduced in the sample flow, enabling the regent to interact with the sample in situ. Most laboratory instruments occupy bench space, and as such they can be limited in terms of access. Furthermore, most laboratory instruments are relatively expensive, and so the number of instruments available for use by laboratory personnel may be limited. In recent years, smaller and lower cost instruments have become available, but these can cost several thousands of dollars once they are configured to be a fully functional instrument. Many of the newer generation of instruments utilize fiber optic cables to couple the spectrometer to the sample. While these present some flexibility, they are also constrained by the length of the fibers and the overall lack of flexibility of the cable. All cables and fibers are limited in their flexibility by their bend radius. Also, fiber optics can impose signal quality issues on the collected spectral data that can negatively impact the final results unless careful consideration is given to the way the system is implemented. In certain industries and for certain applications, such as environmental measurements, it is desirable to make measurements in a non-laboratory environment. Examples can include measurements on water samples taken at an industrial site or from a stream, river or lake for contaminants or undesirable materials. In such cases, the measurements ideally must be made on a portable instrument. In the absence of a portable instrument there is the burden of sending collected samples back to a laboratory for analysis. Most portable instruments still require the use of a cell, and most require samples to be prepared by mixing with reagents followed by a transfer to the cell. This is not always a convenient scenario. The ideal situation would be to sample directly after the reagent is added without the need to transfer to a cell, or if possible to sample directly from the source, where the reagent is introduced as part of the sample handling. Such systems are not currently available for field-based (non-laboratory) sample handling. Thus, while small format instruments exist and are used for standard types of measurements with standard cells, they still possess many of the limitations of traditional instruments. Also, it is normal for most portable instruments to be restricted in performance and perform a small number of fixed analyses. SUMMARY OF THE INVENTION The present invention uses a miniaturized, low cost spectral sensing device, a major advancement in measurement opportunity over the status quo, and overcomes issues related to size or space occupied in the laboratory, or the size of a portable spectrometer. Each device is intended to provide the functionality of a normal spectrometer or spectral analyzer, but at reduced cost, and with a significantly reduced size for the total package. The spectral sensing component of the present invention is based on existing optical sensing technology constructed in accordance with the principles set forth in commonly-owned U.S. patent application Ser. No. 10/913,819 filed Aug. 6, 2004 (now U.S. Pat. No. 7,057,156), incorporated herein by reference, in its entirety. The spectral sensing systems described feature specially assembled detection devices that incorporated the spectral selection elements required to generate the spectroscopic data for subsequent analysis. One set of examples are linear variable filter (LVF) systems based on a silicon photodiode array that can offer spectral ranges of 360 nm to 700 nm (visible) and 600 nm to 1100 nm (short wave near Infrared (NIR)). This also includes multi-element detectors that feature filter mosaics or filter arrays, such as multi-element color sensing devices. The current implementations feature the spectral selection devices, nominally in the form of interference filters (LVF or otherwise) that are produced as an integrated component as part of the detector array fabrication, either by the array manufacturer or by a company specializing in thin film deposition. In likeness to the patent application referenced in the preceding paragraph, the current invention includes full integration of the sample handling with the spectral sensing, and the spectral measurement electronics. The sample interface, the light source for the spectral measurement, the spectral detection system, the primary signal acquisition electronics, and the signal processing and display of the final analytical results are provided within a single package. In one of the proposed forms, the package includes a sample transport mechanism whereby the sample, in liquid form, is drawn into the measurement area by an integrated pumping or suction device. Said pump is either mechanically actuated by a spring or suction mechanism or electrically actuated by a suitable micro pump. The sample area is integrated within a disposable sampler, and can be similar in concept to disposable pipettes or to the disposable tips used for micro-pipette systems. In one form of the samplers, denoted as Smart Tips™ or Smart Samplers™, the reagents are included in an immobilized form. When these samplers are used, the sampler is constructed to provide mixing of the reagents either prior to entry into the measurement zone, or within the measurement zone, thereby eliminating the need for external handling or mixing of reagents. An option is included to make these Smart devices identifiable to the measurement system either by mechanical (keyed) or electronic means. The spectral sensing systems can take a form similar in size and construction to a single-channel micro-pipette or a general purpose dispensing system, and can be battery powered. The systems can include hardwired communications to a PC, laptop or handheld PDA via standard interfaces, such as USB, and can have the option for wireless communications via one of more of the standard protocols such as BlueTooth, ZigBee, IEEE 802.11b/g or equivalent standards. It is an object of the present invention to provide an integrated spectral sensor. The term integrated is used to indicate that the device is to be fabricated as a single structure, where the components are intimately interconnected in a miniaturized platform. The system includes a sampling component, a spectral engine including a light or energy source and a sensing component and a signal conditioner, a signal exchange system, and a controller, all assembled as a single inter-connected structure. The interfacing optics form part of the structure, with no requirement for additional imaging elements such as lenses or mirrors, as used in spectrometers, and as such is differentiated from traditional instruments and spectrometers. The system can be configured to measure light/energy absorption or light/energy emission (as in fluorescence or luminescence). In the standard form the sampling component is in the form of a separable chamber with tip and optional sample transport mechanism (alternative designs can feature a separated pumping device), which can be made of a suitable material, such as a common plastic, that renders the part disposable. The sampling component interfaces intimately with the spectral engine that includes an optical sensing system for nonintrusive detection of the spectral or optical characteristics of the sampled medium (normally a fluid). The spectral engine further includes a light or energy source, spectral sensing component, featuring a fully integrated spectrally selective detection device (described as a spectrometer or a photometer on a chip or alternatively as an integrated sensing module including integrated circuit components), for measuring the characteristic chemical or physical features of the sample medium, an interface for a removable sample cell or chamber that is intimately connected to the source and sensing element, and is dimensionally optimized and matched to these components, and a microprocessor for conditioning the signals output from the spectral sensing element. Additional functions of the microprocessor include spectral data extraction, and the calculation of chemical composition or properties, method and calibration storage, and data communications. The signal exchange system may be a wired or a wireless signal transfer device coupled locally or remotely to the sensor. The primary power for the electronics is provided nominally via batteries, which can be of the rechargeable variety if required. However, the option to use tethered power, such as via a USB cable is included. In its standard format the spectral sensing device includes an integrated sample transport system to provide a means to introduce the sample fluid into the measurement region. In its simplest form, this sample transport is provided via a simple squeeze bulb, suction bellows or spring-driven piston pump, as implemented in commercial micro-pipettes. In an optional form, a piston device or another form of pump, such as a piezo-driven micro-pump, features an electronically controlled drive mechanism. Swept sample volumes can be small, being of the order of a few hundred microliters to a few milliliters (dependent on pathlength), at the most, and so the pumping capacity can be correspondingly low. In its standard form the fluid is drawn into the measurement region of the sensing device, as noted, via an integrated pump or suction device. The measurement region is a removable component, defined as a sampler, and is implemented in the form of a modified pipette-like structure, where the fluid is drawn in through a tip. The sampler measurement chamber includes reflective elements encapsulated and/or retained within the construction. These reflective elements capture the light/energy emerging from the source mounted within the optical interface of the spectral engine. This light/energy is then returned, in a retro-reflective manner back to the spectral sensing element (detector), which is also mounted within the optical interface of the spectral engine. In this mode of operation, the light/energy passes through the fluid at least three times; twice to and from the spectral engine and once between the two reflective elements. This produces a composite dimension, which is known as the pathlength. This is equivalent to a single pass through a conventional liquid cell. These dimensions can be set to be equivalent to normal pathlengths used in conventional cells, and these will be nominally from 1.0 mm to 10.0 cm (total distance). It is expected that in the standard format, this measurement chamber will be constructed from an optically transparent medium, and for most applications, this will be a clear plastic material. The latter is to be constructed as a molded part in the most common implementation of the device. The total sampler construction can be produced in two or more parts, with the inner measurement area being encased within a black and/or optically opaque external shell. In the common implementation this can be made as a co-extruded part, or as an assembly made from two or more separate molded parts. Note that the optically opaque exterior of the sampler will make a positive light seal with the outer casing of the main measurement system. In this manner, the measurement area is shielded from external light sources, thereby ensuring accurate photometry, and also enabling low-light measurements, such as fluorescence and luminescence. In the standard mode of operation it is assumed that the fluid being measured will already contain an active chromophore (light absorbing entity related to the analyte) or fluorophore (light emitting entity related to the analyte). This chromophore/fluorophore will either be native to the material being measured or induced by the use of one or more specific reagents. The mixing of reagents to form a measurable solution is a standard practice in most testing laboratories, and it is also a standard procedure for most field-based testing. The micro-spectral sensing system described in this package has the advantage that the swept volume required for the fluid by the measurement system is in the region of a few hundred microliters to a few milliliters. This reduces significantly the overhead for reagents, and it also reduces the environmental impact for disposal of the fluid after analysis. This provides an additional advantage insofar as it makes some measurements practical that would be otherwise too expensive to perform because of the high intrinsic cost of the reagent. Examples of such measurements exist in the biotechnology and medical testing areas. In an attempt to make the interaction of reagents with the fluid under study more efficient, in terms of ease-of-use, removing the need for mixing vessels, reducing exposure to reagents, and significant cost reductions for expensive reagents, Smart Tips™ or Smart Samplers™ are used. Smart Tips/Samplers are designed to enable reagent interaction and mixing to be carried out in situ, without the need for external reagents or mixing vessels. The internal architecture of the tip or sampler includes molded features that generate turbulences when the fluid is drawn into the tip. Just sufficient reagent (or reagents) to fulfill the requirement of the analysis can be located in an immobilized form (encapsulated in a water/solvent soluble solid medium or a hydrophilic medium) adjacent to the entrance of the tip. The medium and the reagent can dissolve in the sample or interact with the sample as it enters the tip or sampler, and the consequent solution can be agitated during its passage into the measurement region. An option in the design is to key the fitting of the tip to the body of the measurement system in a way that the specific analysis can be automatically defined within the measurement device. This can be accomplished either by a physical key, or via electronic means, such as a bar code, a digital bar code, or by a technology such as RFID. In the case of the digital bar coding, this can be implemented by the use of an additional, well-defined chromophore/fluorophore (non-interfering) mixed in with the reagent. As indicated, the spectral measurement device is primarily intended for use with fluids. However, optional tips/samplers and optional optical interface layouts will be considered for measurements of solids and gases. These optional tips/samplers may be simple adaptations of the existing tips/samplers, such as the combination of an embedded chromophore located within the optical path, where this chromophore interacts with a reactive component in a gas or vapor. In the case of solids, the analyses can be made by direct contact with the surface material based on a diffuse reflectance or interactance method of measurement. Numerous application areas have been identified that can benefit from this integrated sensor approach, and these include the water quality measurements for environmental and public safety requirements, general laboratory testing for food, beverage and consumer products, applications in the chemical and petroleum industries, and medical and clinical applications. Most of these applications already have prescribed and developed methods, and where reagents are involved, the reagent chemistries are already standardized, and the materials are readily available, either as prepared chemicals or in kit form. Many of the methods are standardized by agencies such as the EPA, ASTM, the FDA, the USP, and the AOAC (food and beverages). The system described herein is a convenient, low cost and rapid system to enable these measurements in almost any work environment. As noted earlier, not all analyses require chemical reagents. Those materials containing natural chromophores/fluorophores can be measured directly, and as in the case of reagent-based chemistries, standardized methods for measurement and data presentation already exist. The applications go beyond those mentioned, including those linked to consumer products and consumer-important measurements. It is to be understood that the present invention has broader applicability than the application areas cited. The standard methods of analysis that are referenced in the preceding paragraph normally involve some form of formula for the calculation of the final results. The formula often contains numerical relationships and coefficients that are applied to the raw data and these are determined by running predefined calibration standards. The system as described can be used to develop this type of calibration. The calibration can be carried out within a controlled environment, and with a live connection to a PC or laptop computer for data logging and storage. The calibration set can then be handled by an established procedure, such as a Beer-Lambert based calculation of light/energy absorption versus concentration relationship. The coefficient(s) and intercept can be downloaded into the measurement system along with measurement settings and criteria. Complex applications can require multivariate modeling, and in such cases the modeling equations can be downloaded. The architecture of the onboard microprocessor can be sufficiently flexible to accommodate such downloads, and can accommodate multiple models/calibrations, dependent on the size of the calibration data, and the available onboard memory storage. This enables an end-user to customize the measurement system for a broad range of applications. The system is not limited by design to fixed analyses. Individual methods stored in the measurement system can be recalled at anytime, by a user interface linked to the display on the front of the unit. The method of uploading (results) and downloading (methods and calibrations) can be enabled via either direct physical coupling to a PC, laptop computer or handheld PDA, or via a wireless connection. Options for direct coupling can be via a standard serial interface, such as a USB port, or via some other standardized interface such as Ethernet or Firewire. The wireless connection can be optional, and can be implemented on board the main electronics in a standardized format, such as BlueTooth, ZigBee, or a standard IEEE 802.11b/g or IEEE 802.14b. In order to implement the Ethernet option, or the wireless option, the device can be provided with a user-configurable IP address. In this form, one option for communication with the device can be from a web server, which will provide the option for remote access for upload and download. The integrated sample, sensing and data of the present invention provides a more efficient method of fluid sample analysis than conventional instruments. This and other advantages will become more apparent upon review of the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross section of an example embodiment of a spectral sensing engine: integrated source, sample interface, spectral analyzer and detector. FIGS. 2A , 2 B and 2 C are example combinations of optical filters and detector components used for spectral sensing. FIG. 3 illustrates example electronic components for the integrated spectral sensor. FIG. 4 illustrates example embodiments of the spectral sensing components-electronics. FIG. 5 illustrates an example embodiment of the spectral engine component-sample integration. FIG. 6 illustrates example embodiments of the spectral engine with sample interface tips. FIG. 7 illustrates an example embodiment of the spectral engine with the sampler and its sample chamber and bellows. FIG. 8 illustrates example embodiments of the spectral engine alternatives for solid sampling. FIG. 9 illustrates an example embodiment of a Smart Tip™ located on the spectral engine. FIG. 10 illustrates an alternative embodiment showing the Smart Sampler™ with immobilized reagents in the tip or the sample housing. FIG. 11 illustrates an example embodiment for a pipette-style design for spectral sensor. FIG. 12 illustrates an example embodiment for a handheld design for the spectral sensor. FIG. 13 illustrates an example embodiment of alternative design for an insertion spectral sensor. FIG. 14 illustrates an example spectral sensor response in the visible region: colored dye solutions. FIG. 15 illustrates an example spectral sensor response in the near infrared region spectra of common chemicals. DETAILED DESCRIPTION The present invention is an integrated handheld measurement system for spectral sensing of aqueous and organic solutions, certain gases and vapors, and for certain solid substrates, such as powders and extended solid surfaces. The sensing aspect of this invention preferably includes one or more miniaturized optical spectral sensors located within the body of the handheld device. Several different embodiments are described for the body of the device, and examples are cited later in FIGS. 6 to 13 . FIG. 1 provides a symbolic representation of an example spectral sensing system, comprising a light or energy source 10 , an optimized and integrated sample chamber 11 , a spectral analyzer or spectrally selective element 12 , and an integrated detection system 13 . Example embodiments of such spectral sensing systems are illustrated in FIGS. 4 to 10 . In the configuration shown in FIG. 1 , the source is indicated as an incandescent-style of source, such as a tungsten source. The invention covers various types of sources, such as solid-state sources (LEDs and diode lasers), MEMs-based thermal sources and gas discharge devices, where the source is optimized for the application and the spectral range of the overall spectral measurement system. The optical layout shown in FIG. 1 represents an energy/light transmission (or absorption) style of measurement. The technology, enables light scattering and optical emission measurements, such as fluorescence, phosphorescence, and luminescence, and can also be configured for reflectance and transflectance (transmission-reflection) measurements from surfaces. The latter is indicated as an example embodiment in FIG. 8 . The individual spectral sensors are intended to be small and convenient to use, and can be optionally fabricated as low cost devices. As such, multiple implementations of the handheld devices can exist in the work place, or even in the home. An optional component of the system is a wireless communications interface, based on a standard wireless platform, and conforming to published standards such as the IEEE 802.11b/g, ZigBee and Bluetooth. The system design includes the wireless components located on the main electronics board(s) as shown, for example, in FIGS. 4 and 5 . The objective of the wireless components is to provide an easy mechanism to download results from the spectral measurement device, and to upload new calibrations and measurement schemes. An important component of the spectral sensor technology can be broadly described as an optical spectrometer on a chip as represented in FIG. 2 by 14 , 15 and 16 . Such an optical spectrometer on a chip thus forms an integrated sensing module having a detector that includes a solid-state device either matched directly in spectral response to a source, or capable of responding to wavelengths over a broad spectral range from one or more sources, sensitive in spectral regions of UV (230 nm to 400 nm), UV-visible wavelengths (350 nm to 700 nm) near infrared (600 nm to 2500 nm) and mid-infrared (2.5 μm to 25 μm, 2500 nm to 25000 nm). While optical sensors have been available, the present invention integrates an optical filter assembly 12 with a light or energy sensitive array 13 ( FIG. 1 ). The optical filter technology used is either in the form of a continuous linear variable filter (LVF) 14 , 15 , or a filter array (patterned filter or mosaic) 16 . In the LVF form, the resultant device or spectral sensing component 14 , 15 , is the most versatile and can be utilized for many applications, and for different spectral ranges, dependent on the detector array technology used. An example format of an LVF-based spectral sensor is shown in FIGS. 1 , 2 A and 2 C. In low-cost examples, the spectral sensing component is preferably implemented as part of a photodiode or a Complementary Metal-Oxide Semiconductor (CMOS) array detector package 15 . In the current embodiment, the LVF is directly bonded to the detector array, which preserves the spectral resolution of the LVF. In this form the assembly does not require any form of resolution retaining optics. Sensors derived from these components based on the LVF can be used for absorption measurements in the mid-range UV, long-wave UV, the visible and the short-wave near infrared (NIR), as well as fluorescence measurements in the visible and NIR. Examples of data have been acquired in all of these modes, and example spectral response curves for the visible and NIR ranges are provided FIGS. 14 and 15 , respectively. The short wave NIR provides good differentiation based on chemistry and composition based on vibrational overtones of the component molecules. This spectral region can be applied to organic and inorganic compounds, and also aqueous solutions containing high concentrations of solutes. However, in cases, such as the digestions in pulp and paper applications, where visible absorbing and fluorescence centers are also expected to be important, the visible version for the spectral sensor can also be used. For applications involving chemistry, where the species to be measured is not normally visible, the analysis may be performed with the addition of a reactive chemical reagent. For many applications, reagent-based chemistries are the basis for standard laboratory measurements, where the reagent and the sample are manually mixed prior to the analysis. The analysis typically involves a visible (color) or fluorescence based measurement. In an alternative configuration of the sample handling interface, for the handheld pipette-style of sensor ( FIGS. 6 and 11 ) or the chamber-based handheld sensor ( FIGS. 7 and 12 ), the reagent is immobilized within the tip of a Smart Tip™ ( FIG. 9 ) or within the tip/chamber of a Smart Sampler™ ( FIG. 10 ). As defined, the spectral sensor can be constructed from either a continuously variable filter (defined as the LVF) 14 or from a filter matrix or mosaic 15 . This latter approach is usually optically more efficient and less expensive than the LVF approach. It is often more specific in application, but less versatile than the LVF system. An illustrated example of a matrix-based spectral sensor 16 is provided in FIGS. 2 and 3 . The version shown is a 4-channel RGBW (Red-Green-Blue-White) sensing device, and is capable of handling a wide range of color-based applications. Custom versions of this sensor, featuring more than 4-optically selective channels can be used. New technologies, involving the deposition of the wavelength selective devices on the surface of the detector elements can be used to make application specific detection devices. In such cases, the mosaic can feature both the optical filter and the detector as discrete components. Such devices can be assembled as hybrids, providing spectral detection in more than one spectral region, such as a combination of the UV, visible and NIR. An example application can be for the measurement of bio-materials, such as proteins and amino acids, where one or more solid state excitation sources are used (such as 280 nm and 340 nm), and where detection is made in the UV (ca. 340 nm) and in the visible. The sensor hardware for the present invention is not limited to silicon-based photo-sensing devices, and alternative detector arrays can be used, including InGaAs, PbS, PbSe, LiTaO 4 and also MEMS-based devices. Such devices would be considered for extensions into the longer wavelength NIR and for the mid-IR. The format of the proposed sensor platform may be extended into these other spectral regions. For these cases, alternative optically transparent media may be required for the sample chamber and the optical conduit construction, and these can include materials such as quartz, sapphire and zinc selenide. The onboard electronics that form part of the spectral engine ( FIGS. 3 to 5 ) provide for the primary data acquisition from the spectral sensing/detection devices. Initially, the raw signal obtained needs to be conditioned and scaled. This is effectively a transformation from the raw signals from the physical device to a spectral based data array (or spectrum), defined in wavelength (or energy) units (x-axis) and intensity units (y-axis). A standardized or unified data format (UDF) is used to provide a well-defined start and end to the spectral data, and with a clearly delineated data interval (data point spacing). The signal handling and these primary data transformations are shown as a symbolic representation in FIG. 3 , and are handled by what is defined as μP- 1 (microprocessor function 1 ) 17 . In order to complete an analysis, it is usually necessary to extract the relevant intensity information from one or more predefined regions of a spectrum. This intensity data is further manipulated by one or more numerical functions, which normally include unique calibration data for the species being measured. These additional mathematical functions are performed by the symbolic representation defined as μp- 2 (microprocessor function 2 ) 18 and these are incorporated in what is defined as a method. The methods, which are downloaded into the memory (such as flash RAM) or the system, include data acquisition instructions, spectral data pre-processing, data extraction from the spectra, and also the subsequent calculations to provide the final answers. Those skilled in the art of optical sensing technology will recognize that the short-wave Near Infrared (700 to 1100 nm) works well for a wide range of liquid-based measurements. Although spectral changes in this region are subtle, they can be readily correlated with both composition and key chemical and/or physical properties. Tools such as multivariate modeling, sometimes known as chemometrics are common for such applications. These are used, as appropriate, and the calibration coefficients generated from the modeling are stored on memory (such as flash RAM) associated with one or more microprocessors associated with μP- 2 , FIG. 3 ( 17 and 18 ), located on-board the sensor. Note that the functions for μP- 1 and μP- 2 can be combined in a single processor if required. The flash RAM can be either present as separate memory components, or integrated into the microprocessors. It is noted that this numerical treatment is not unique to the NIR spectral measurement range, and the onboard computing facilities defined will also be used for resolving complex mixtures in other spectral regions served by the handheld devices described in this invention. The component labeled μP- 2 18 can also handle communications and display functions. Communications can be either hardwired, such as a standard serial COM device (UART function on mP- 2 ) or as a USB device, or as wireless communications. The latter can be incorporated as components with separate functionality from μP- 2 18 . The display function can include an onboard display for the handheld sensor, and can range from a simple multi-line display to a full-scale RGB XGA or other standard display device. In the practical implementation, the spectral sensing elements can be fully integrated as a single entity or assembly on what are described as the sensing components in FIG. 4 . This optical sensor assembly (or opto-board) includes the light source 19 and the spectral sensing element or detector 20 . These devices are optically isolated from each other by an optical mask fabricated from an optically opaque material 21 , such as a carbon-filled elastomer. Example embodiments are shown in FIG. 4 with circular and rectangular cross-sections. The choice of cross-section is dependent on final sensor configuration and application. The main system electronics board 22 is directly coupled to the optical sensor assembly via either a hard connector on the back of the opto-board, or via internal cabling or flex-based connectors. The source and spectral detection components are interfaced to the sample measurement cavity (or chamber) via light pipes, light guides or light conduits. For the example illustrated, this is hard coupled to the sample chamber, and is designed to minimize optical crosstalk between the light source and the detection system. In alternative configurations, the light guides can be in the form of optical fibers. In visible and NIR spectral regions, optical pathlengths can range from 0.1 cm to 10 cm and these are considered to be optimum, dependent on the material to be measured. For visible measurements, the selection of pathlength is usually method dependent and is a function of the color density of the solutions under study. For the NIR, the longer pathlengths may be used for direct measurements made on organic chemicals, while shorter path lengths may be required for optically darker materials or water-based solutions. The pathlength is defined within the integrated construction of the sensor measurement cavity thereby providing close-coupled sample chamber 24 ( FIGS. 5 , 6 and 7 ). In order to make the sensor a single-sided entity, suitable for example for pipetting or dipping, it is necessary to use a folded path construction, as illustrated in FIGS. 5 , 6 and 7 . This folded pathlength 24 a and 24 b is obtained by the use of retro-reflective elements 25 located within the measurement cavity. Note that the example geometry is for a transmission-based measurement. Sample emission (such as fluorescence) or light scattering (such as turbidity) measurements can require alternative geometries, where the source and detection system are orthogonal (at 90 degrees) to each other, relative to the sample chamber. For most measurements the sample, as a liquid ( FIGS. 6 and 7 ) or as a solid ( FIG. 8 ) interacts directly with the source and detection system within the sample area. In the case of where a reagent is involved with a liquid sample, in the configurations shown in FIGS. 6 and 7 , it is assumed that the reagent interacts with the liquid outside of the sample measurement area. However, an alternative is to feature an immobilized reagent, which is located within the light path. In such cases, the reagent may be included within a transparent substrate as pads 24 c in the light path within the measurement cavity ( FIG. 10 ) or on an opaque, reflective surface. In the latter case, the solid sampling approach of FIG. 8 is required for the measurement. Examples are pH or test-paper measurements, where the liquid sample reacts in situ with the reagent that is immobilized in a porous solid matrix, such as a sol gel or a membrane (organic or inorganic) or an absorbent paper matrix. In examples where immobilized reagents are used and the optical measurement is made within the light path, special tips or sample chambers will be used with the immobilized reagent. In the case of the special tips ( FIG. 9 ) the immobilized reagent substrate is located within the fluid path of the tip. In the case of the implementation within the sample chamber the substrate including pads 24 c is placed at the end of the entrance (and/or exit) points of the optical light guides. In the example preferred embodiments shown in FIGS. 6 , 7 and 8 the spectral engine is constructed as two separable parts. The spectral sensing components and associated electronics ( FIG. 4 ) and the sample interface, which is intended to be removable, and optionally disposable. The spectral sensing components and the electronics are located within the main body of the sensor ( FIGS. 11 , 12 and 13 ). The sample chamber is located within the removable tip or sampler, which can be constructed in different forms dependent on the applications. In one version of the sensor, the device takes the form of a mechanical micro pipette where the sample is transported into the sensor tip via a built-in piston pump (or equivalent). In this form, the tip is constructed with the external appearance of a pipette tip 27 ( FIG. 6 and FIG. 11 ). In a second version of the sensor, which is a preferred embodiment, the measurement module is independent of the sample transfer, which takes place within the completely separated sampler assembly. In this form the sampler has a common construction to a disposable pipette with a bellows (or bulb) style pumping (suction), and with the sample chamber mated on the side where the sample flow takes place. During the filling process the liquid fills the measurement cavity by the suction process, and any residual bubbles rise into the upper flow channel (or the bellows/bulb) and out of the optical path. The sensor can also be configured to measure liquids by immersion or insertion (a dip tip configuration). In this format, the sample enters the sampling area from slots, perforations or apertures in the sides of the tip 28 ( FIG. 6 and FIG. 10 ). This form of sensor tip has a two part main construction, comprising an inner optically transparent part and an external optically opaque part. The construction of the outside part is such that there is no light leakage from the outside into the internal sample chamber or measurement area. Alternatively stated, the external part of the tip is constructed to eliminate the opportunity for external (ambient) stray light to enter the measurement zone. In the most common form of construction, both parts of the tip can be made from plastic materials (polymers). Also, in most cases, the materials can be fabricated from some form of co-extrusion process. Note that the internal reflective elements 25 for the sample chamber are to be fabricated from a reflective insert or with a reflective coating. In either case, the coating or the insert can be protected from the measurement medium by embedding within the plastic or by a protective top coat. In an alternative sampling configuration ( FIG. 8 ), the sample tip 29 is designed to be open-ended. In this format, the spectral sensor is intended for use with solid materials, where the sensor measures the reflected light from the solid sample surface. This may be used to measure reacted test strips (pH strips, water testing strips, medical test strips, for example), color from solid surfaces (powders, extended solids and fabrics, for example), or material composition, such as a transparent coating. The application of the standard tips or samplers for liquids is intended to serve either applications that involve the direct spectral measurement of liquid samples, based on their own natural color or natural absorption (UV or NIR for example) or fluorescence. In other examples, with the standard tips or samplers, the sensor will work as a spectrometer or photometer for a standard reagent-based measurement, where the reagent is mixed externally with the sample prior to sampling and measurement. Alternative forms of tip or sampler, known as a Smart Tip™, FIG. 9 , or as a Smart Sampler™, FIG. 10 can both be included. The smart tip includes the reagent or reagents within the body of the tip. With the Smart Sampler, the reagent can be located within the tip and/or within the measurement chamber. For the smart tip the reagents are in an immobilized form 30 , where they are either encapsulated within a water-soluble (or solvent-soluble) medium, or they are embedded within a water/solvent permeable membrane. In such cases, the reagent is mixed in situ as the sample is drawn into the entrance of the tip. The mixture of sample and reagent is then drawn through a series of vanes 31 , that provide a “tortuous” pathway, or mixing pre-chamber 31 a , where the two components (reagent(s) and sample) are thoroughly mixed and are given time to react. The mixed and reacted solution is then drawn into the measurement chamber. For most applications, this process is expected to be a smooth, single-step action, and is part of the overall sampling where the sample is drawn into the tip. In the case of the smart sampler, the reagent can be alternatively be immobilized within an adsorbent structure where mixing occurs by passage through the adsorbent material ( FIG. 10 , 30 / 31 ), or it can be immobilized in light transmitting pads 24 c located within the light path of the measurement chamber ( FIG. 10 ). The benefit of these approaches is that minimal reagent quantities are used, an ideal scenario for many modern applications in the bio-chemical and medical fields where specific reagents are extremely expensive. In addition, this approach eliminates any external contact with the reagents (important if the regent materials are toxic or intrinsically corrosive), and it simplifies disposal. The entire approach is environmentally friendly, eliminating the use of excess reagent materials and reducing the quantities of materials for disposal. The specific regents can be identified by the external design or appearance of the tip, by using color coding, bar coding or by the use of a technology such as RFID. Three example embodiments of the sensor system are illustrated, FIGS. 11 , 12 and 13 . The first is the fully self-contained pipette-based version FIG. 11 , is described as the SpectraPette™, which includes an integrated pumping system 32 for the sample transport. The pumping can be implemented in the form of a simple piston pump. Alternatively, a mechanized pumping, based on an electrical micro pump (rotary or piezo, for example) can be used. Note that this format can support either the standard measurement tips of the Smart Tips. A second format, where the sample is introduced via a sampler that contains the sample transport mechanism and is the form of a suction bulb or bellows, is illustrated in FIG. 12 . In this format, the main body of the sensor is fully self-contained and only has a light path interface with the sampler. The complete measurement system, is designed to be handheld, but is also designed to be freestanding on a solid surface. In the final example format, where the sample is introduced following emersion or insertion into the liquid, the sensor is a simpler construction because there is not the requirement for the pumping action for sample introduction ( FIG. 13 ). All sensor formats are intended to be battery-powered, where standard dry cells or rechargeable batteries are used. The main body of the sensor includes a display 33 and push-button user interface controls 34 for the selection of methods, and the display of results, and a minimum set of controls. Note that the display is not limited to a three-line format, and can display graphical information as well as alpha-numerics. In the most basic form of the sensor, the controls 34 can include functions such as power on-off, method selection, measurement activation, and transmit (for the transmission of results/data). Automatic features can include auto-power down, and auto-transmit to a local central PC for data logging, of both raw and processed spectral data. The approach offered is described as being based on a spectral engine ( FIG. 1 ), which is further illustrated in its final embodiments in FIGS. 11 , 12 and 13 . The spectral engine includes the spectral sensing device (described above) 14 and 15 , and the energy source 10 and 19 , which can be either a broadband or narrowband source, dependent on the mode of measurement (broadband sources are used for NIR and visible absorption, narrowband sources are used for turbidity and fluorescence). White LEDs, LED arrays and tungsten bulbs are used as example broadband sources, and individual LEDs and semiconductor laser devices are used as narrowband sources. Another component of the spectral engine is the sample interface, which is typically a cavity or chamber 24 . One of the key benefits offered by the system is that the sample chamber is optimized in size based on the physical dimensions of the spectral engine sample interface. The sizes of the detection devices are, for example, 1 mm×8 mm 15 and approximately 3 mm×3 mm (matrix sensor 16 ). Scaling the sample cell to these physical dimensions can produce sample chamber volumes as low as 80 microliters. The advantage gained here is that a minimum sample size is required, which effectively eliminates any sample temperature effects, and significantly reduces the amount of reagents that have to be dispensed for reagent-based applications. The volume requirement for reagents can be reduced down by as much as 1000 times, which reduces reagent consumption and operating costs. The final critical set of components of the spectral engine is the electronics. An example of the functional electronics is provided in FIG. 3 , which are physically located within the total sensor body as illustrated in FIGS. 5 to 8 as 22 . Up to two microprocessors, and possibly more can be used for the initial data handling (processor # 1 17 , and then the data massaging processor # 2 18 ). The final processor 18 can feature onboard memory to store methods, calibrations and results, and can handle communications to displays (if required), external devices via serial connections and also wireless communications if the option is used. A single advanced processor is a practical alternative to the two processor format. The spectral sensor implementation is based on basic two-part construction featuring the main spectral sensing system, with common display and controls, and a disposable component; a tip FIGS. 11 and 13 , or a sampler FIG. 12 . Two main formats are offered; one with sample transport, in the format of a micro-pipette ( FIG. 11 ) or a disposable pipette ( FIG. 12 ), and the other as a dip (insertion) or surface measurement device ( FIG. 13 ). The function of the sensor is defined in terms of the tip or sampler ( 27 , 28 or 29 ), and the method of measurement selected from the integrated display 33 . The fundamental aspects of the present invention lead not only to increased productivity, but ready implementation as a portable system for at least the four target application areas: water, chemical, and petroleum, food and beverages, and clinical and medical. In the case of water, an apparatus in accordance with the invention expands testing out of the laboratory, and enables field-based water and environmental testing. It provides similar advantages in a number of consumer-oriented markets, including home-based water testing (including swimming pools), food safety testing, and home-based medical testing. While the present invention has been described with particular reference to certain specifically described components and methods, it is to be understood that it includes all reasonable equivalents thereof, including those as defined by the attached claims.

An integrated spectral sensing engine featuring energy sources and detectors within a single package includes sample interfacing optics and acquisition and processing electronics. The miniaturized sensor is optimized for specific laboratory and field-based measurements by integration into a handheld format. Design and fabrication components support high volume manufacturing. Spectral selectivity is provided by either continuous variable optical filters or filter matrix devices. The sensor's response covers the range from 200 nm to 25 μm based on various solid-state detectors. The wavelength range can be extended by the use of filter-matrix devices. Measurement modes include transmittance/absorbance, turbidity (light scattering) and fluorescence (emission). On board data processing includes raw data acquisition, data massaging and the output of computed results. Sensor applications include water and environmental, food and beverage, chemical and petroleum, and medical analyses. These can be expanded into various field and consumer-based applications.

This is a continuation application of Ser. No. 07/855,122, filed Mar. 18, 1992, now abandoned, which is a continuation application of Ser. No. 07/413,837, filed Sep. 28, 1989, now abandoned. BACKGROUND OF THE INVENTION This invention relates to preparing carbon fibrils. Carbon fibrils are carbon microfibers having diameters less than 500 nanometers. They may be prepared by contacting a metal-containing catalyst with a carbon-containing gas at elevated temperatures. SUMMARY OF THE INVENTION In a first aspect, the invention features a fibril aggregate that includes a multiplicity of carbon fibrils whose longitudinal axes have substantially the same relative orientation, each of the fibrils characterized as having graphitic layers that are substantially parallel to its longitudinal axis and being free of a continuous thermal carbon overcoat (i.e. pyrolytically deposited carbon resulting from thermal cracking of the gas feed used to prepare the fibrils). One aspect of substantial parallelism is that the projection of the graphitic layers on the fibril's longitudinal axis extends for a relatively long distance in terms of the external diameter of the fibril (e.g., at least two fibril diameters, preferably at least five diameters), as described in Snyder et al., U.S. Ser. No. 149,573 filed Jan. 28, 1988 refiled as continuation application Ser. No. 494,894, filed Mar. 13, 1990, refiled as continuation application Ser. No. 694,244, filed May 1, 1991 and entitled "Carbon Fibrils" which is assigned to the same assignee as the present application and hereby incorporated by reference. Carbon fibrils having substantially parallel graphitic layers are also described in Tennent, U.S. Pat. No. 4,663,230 ("Carbon Fibrils, Method for Producing Same and Compositions Containing Same"), Tennent et al., U.S. Ser. No. 871,676 filed Jun. 6, 1986, refiled as continuation application Ser. No. 593,319 filed Oct. 1, 1990, now U.S. Pat. No. 5,165,909, issued Nov. 24, 1992 ("Novel Carbon Fibrils, Method for Producing Same and Compositions Containing Same"), Tennent et al., U.S. Ser. No. 871,675 filed Jun. 6, 1986 refiled as continuation application Ser. No. 492,365 filed Mar. 9, 1990, now U.S. Pat. No. 5,171,560, issued Dec. 15, 1992 ("Novel Carbon Fibrils, Method for Producing Same and Encapsulated Catalyst"), Mandeville et al., U.S. Ser. No. 285,817 filed Dec. 16, 1988, refiled as continuation application Ser. No. 746,065, filed Aug. 12, 1991, refiled as continuation application Ser. No. 08/284,855, filed Aug. 2, 1994 ("Fibrils"), and McCarthy et al., U.S. Ser. No. 351,967 filed May 15, 1989, refiled as continuation application Ser. No. 823,021, refiled as continuation application Ser. No. 117,873, refiled as continuation application Ser. No. 08/329,774, filed Oct. 27, 1994 ("Surface Treatment of Carbon Microfibers"), all of which are assigned to the same assignee as the present application and are hereby incorporated by reference. In preferred embodiments, the diameters of at least 90% (and, more preferably, substantially all) of the fibrils in the aggregate have diameters between 3.5 and 75 nanometers, inclusive. Similarly, at least 90% (and, more preferably, substantially all) of the individual fibrils in the aggregate have a length to diameter ratio of at least 5. The diameter of the aggregate preferably is between 0.05 and 50 μm, inclusive, and the length preferably is between 0.1 and 1000 μm, inclusive. In a second aspect, the invention features a process for preparing an aggregate of carbon fibrils by contacting a particulate metal catalyst deposited on a support having one or more readily cleavable planar surfaces and a surface area of at least 1 m 2 /g with a carbon-containing gas in a reactor at reaction conditions including temperature sufficient to produce the aggregate. In preferred embodiments, the support is a metal oxide, e.g., γ-alumina or magnesia, both of which are in the form of aggregates of tabular, prismatic, or platelet crystals. Preferred catalysts include iron. They may further include at least one element chosen from Group V (e.g., vanadium), VI (e.g., molybdenum, tungsten, or chromium), VII (e.g., manganese), or the lanthanides (e.g., cerium). Also preferred are catalysts that include cobalt, nickel, manganese, or a combination of copper and zinc. The catalysts may be prepared using either aqueous or non-aqueous solvents. Preferred reaction temperatures are between 400° and 850° C., more preferably between 600° and 750° C. Preferred aggregates are those aggregates described above in which the longitudinal axes of the fibrils making up the aggregate all have substantially the same relative orientation. The invention also features a particulate, carbon fibril-forming, metal catalyst deposited on a support having one or more readily cleavable planar surfaces and a surface area of at least 1 m 2 /g. Preferred catalyst and support materials are those described above. The invention provides a process for preparing fibril aggregates in which the texture of the aggregate is controlled by the choice of catalyst support. Using supports having one or more readily cleavable planar surfaces produces fibril aggregates having the appearance of combed yarn in which the individual fibrils are straight to slightly bent or kinked. Aggregates having loose, open mat textures in which the individual fibrils are straight to slightly bent or kinked may also be produced. These aggregates are readily dispersed, making them useful in composite fabrication where uniform properties throughout the structure are desired. The substantial linearity of the individual fibril strands also makes the aggregates useful in EMI shielding and electrical applications, e.g., the devices described in Friend et al., U.S. Ser. No. 08/284,738, filed Aug. 2, 1994, which is a continuation of U.S. Ser. No. 07/692,849 filed Apr. 25, 1991 entitled "Battery", which is a continuation of Friend et al., U.S. Ser. No. 07/413,844 filed Sep. 28, 1989 now abandoned, and Friend et al., U.S. Ser. No. 07/602,446 filed Oct. 23, 1990, now U.S. Pat. No. 5,110,693, issued May 5, 1992, entitled "Electrochemical Cell" which is a continuation of Friend et al., U.S. Ser. No. 07/413,838 now abandoned, all of which are assigned to the same assignee as the present application and are hereby incorporated by reference in their entirety. Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims. DESCRIPTION OF THE PREFERRED EMBODIMENTS We now describe the structure and preparation of preferred fibril aggregates. Structure Preferred fibril aggregates consist of bundles of straight to slightly bent or kinked carbon fibrils in which the individual fibrils have substantially the same relative orientation, e.g., the longitudinal axis of each fibril (despite individual bends or kinks) extends in the same direction as that of the surrounding fibrils in the bundle. This arrangement of individual fibrils gives the aggregates the appearance of combed yarn, in contrast to aggregates such as those produced according to the process described in the aforementioned Snyder et al. application, U.S. Ser. No. 149,573, in which the fibrils are randomly entangled with each other to form tightly entangled balls of fibrils resembling bird nests. The carbon fibrils within each fibril aggregate preferably have diameters between about 3.5 and 75 nanometers, length to diameter ratios of at least 5, and graphitic layers that are substantially parallel to the longitudinal fibril axis, and are also substantially free of a continuous thermal carbon overcoat, as described in Tennent, U.S. Pat. No. 4,663,230;Tennent et al., U.S. Ser. No. 871,676; Tennent et al., U.S. Ser. No. 871,675; Snyder et al., U.S. Ser. No. 149,573; and Mandeville et al., U.S. Ser. No. 285,817. The aggregates may also be treated to introduce oxygen-containing functional groups onto the surface of individual fibrils, as described in McCarthy et al., U.S. Ser. No. 351,967. Within each fibril aggregate, the diameters and length to diameter ratios of the individual fibrils are essentially uniform. A second type of fibril aggregate consists of straight to slightly bent or kinked fibrils which are loosely entangled with each other to form an "open mat" structure. The degree of entanglement is greater than observed in the combed yarn aggregates (in which the individual fibrils have substantially the same relative orientation) but less than that of the tightly entangled fibril balls formed according to the process described in Snyder et al., U.S. Ser. No. 149,573. Preparation In general, both the combed yarn and open mat aggregates are prepared by contacting an iron or iron-containing metal catalyst particle deposited on a support material having one or more readily cleavable surfaces and a surface area of at least 1 m 2 /g with a carbon-containing gas in a reactor at 400°-850° C. using the procedures described in the aforementioned Tennent patent and Tennent, Snyder, and Mandeville applications. Preferred support materials include γ-alumina or magnesia in the form of aggregates of tabular, prismatic, or platelet crystals. Such material is commercially available, e.g., from Strem Chemicals (in the case of γ-alumina) and Alfa Inorganics (in the case of magnesia). The γ-alumina supports yield primarily combed yarn aggregates, while the magnesia supports yield primarily open mat aggregates. In contrast, the use of supports consisting of spherical particles or aggregates lacking cleavable planar surfaces (e.g., supports made of Degussa fumed alumina as described in the aforementioned Snyder et al. application) leads primarily to tightly entangled fibril balls. While not wishing to be limited to any particular theory, it is believed that the readily cleavable planar surfaces of the support allow the fibrils to assist each other as they grow, creating a "neighbor effect" that, in the case of the γ-alumina support, leads to a combed yarn fibril aggregate in which the individual fibrils have the same relative orientation. Spherical supports, on the other hand, lack this effect, leading to tightly entangled balls of randomly oriented fibrils. The magnesia support, although having readily cleavable planar surfaces, yields primarily lightly entangled, open mat fibril aggregates because it breaks apart more readily than the γ-alumina support during fibril growth, resulting in aggregates that are less ordered than the combed yarn aggregates but more ordered than the tightly entangled fibril balls. The oxide precursors used to generate the metal catalyst particles also affect the tendency of the support to break apart. The more readily the oxide and support can form a mixed oxide at the interface between them, the more likely the support is to break apart. The following examples describe the preparation of combed yarn and open mat fibril aggregates. EXAMPLE 1 This example describes the preparation of combed yarn fibril aggregates. 200 gm of γ-alumina (Strem Chemicals) was heated at 230° C. in a vacuum oven under reduced pressure (25 in. mercury vacuum) for 5 hrs. Next, it was slurried at room temperature with a solution containing 200 gm Fe(NO 3 ) 3 .9H 2 O in 800 cm 3 methanol and the slurry agitated thoroughly for 1 hr. The methanol was then removed in a rotary evaporator by gradually reducing pressure and increasing temperature to boil off the methanol at a reasonable rate; final conditions were 25 in. mercury vacuum and temperature less than or equal to 55° C. The stripping process took approximately 45 minutes. After the methanol had been removed, the remaining solids were dried at 160° C. under reduced pressure (15-20 in. mercury vacuum) in a vacuum oven overnight; the typical catalyst yield after drying was 270 gm. Iron loadings were calculated from starting amounts of Fe(NO 3 ) 3 .9H 2 O and final weights of dried catalysts. Typical iron loadings ranged from 8-11%. Fibrils were grown at 680° C. in a 1 in. quartz tube inserted into an electrical furnace. The catalyst was introduced into the reactor at 680° C. as a free-flowing powder in a preheated gas stream consisting of 2 parts ethylene and 1 part hydrogen at a flow rate of about 2 liters/min., and deposited on a quartz wool plug placed in contact with a thermocouple in the center of the tube. In a typical run, 0.100 gm catalyst yielded approximately 1.0 gm carbon fibrils after 4 hrs. at run conditions. The yield of carbon fibrils is expressed as a factor times the weight of catalyst or the weight of iron. Typical yields for this catalyst were 10-11 times based on catalyst and 100-125 times based on iron. Examination of the fibrils using electron microscopy (SEM and STEM) revealed the fibrils to be present as aggregates of straight to gently curving fibrils having the appearance of skeins of brushed or combed yarn. The aggregates generally were still attached to the alumina support. EXAMPLE 2 15.10 gm of γ-alumina (Strem Chemicals) was slurried in a solution of 14.9 gm Co(NO 3 ) 2 .6H 2 O in 400 cm 3 methanol for 1 hour at room temperature. Methanol was then removed under reduced pressure in a rotary evaporator and dried in a vacuum oven as in Example 1. The calculated cobalt loading was 17.2% by weight. Fibrils were grown at 680° C. according to the procedure described in Example 1. Examination of the fibrils by TEM revealed numerous combed yarn fibril structures in which the individual fibrils were kinked or twisted. The longitudinal axes of the fibrils, however, had the same relative orientation. The fibrils were hollow and had diameters less than 10 nanometers. EXAMPLE 3 14.3 gm γ-alumina (Strem Chemicals) was slurried in a solution of 8.3 gm Ni(NO 3 ) 2 .6H 2 O in 400 cm 3 methanol for 1 hour at room temperature. Methanol was then removed under reduced pressure in a rotary evaporator and dried in a vacuum oven as in Example 1. The calculated nickel loading was 16.3% by weight. Fibrils were grown according to the procedure in Example 1. TEM analysis revealed small combed yarn-type aggregates in which the individual fibrils were straight and had diameters of about 15 nanometers. EXAMPLE 4 16.51 gm γ-alumina (Strem Chemicals) was slurried with a solution of 30.2 gm Mn(NO 3 ) 2 (50% solution in H 2 O) dissolved in 400 cm 3 methanol. Methanol was then removed under reduced pressure in a rotary evaporator and dried in a vacuum oven as in Example 1. The calculated manganese loading was 16.3% by weight. Fibrils were grown according to the procedure in Example 1. TEM analysis revealed combed yarn-type aggregates in which the individual fibrils were slightly tangled. EXAMPLE 5 15.11 gm γ-alumina (Strem Chemicals) was slurried with a solution containing 13N8 gm Cu(NO 3 ) 2 .3H 2 O and 11.1 gm Zn(NO 3 ) 2 .6H 2 O dissolved in 400 cm 3 methanol for 1 hour at room temperature. Methanol was then removed under reduced pressure in a rotary evaporator and dried in a vacuum oven as in Example 1. The calculated zinc and copper loadings were 19.1% and 12.9% by weight, respectively. Fibrils were grown according to the procedure in Example 1. TEM analysis revealed a mixture of combed yarn-type aggregates in which the individual fibrils were straight and had diameters less than 10 nanometers and hollow, open, straight fibrils with diameters less than 10 nanometers. EXAMPLE 6 This example describes the preparation of open mat fibril aggregates. 74 gm magnesia platelets (Alfa Inorganics) was slurried with 400 gm deionized water at 65°-70° C. for 1 hr. with rapid stirring in a baffled reactor. A solution of 112 gm Fe(NO 3 ) 3 .9H 2 O and 5.4 gm (NH 4 ) 6 .Mo 7 O 24 .4H 2 O in 150 cm 3 deionized water was added dropwise over a period of about 1 hr. at 65° C. while maintaining rapid stirring. During the addition, the solids turned chocolate brown. After addition was complete, the slurry was filtered; the supernatant was colorless (pH=about 5) and the solids were a dark red-brown. After washing several times with deionized water, the solids were dried overnight at 160° C. under reduced pressure (15-20 in. mercury vacuum). A typical yield of dried solids was 105 gm. The solids were then calcined at 400° C. for 4 hrs. to yield 74 gm catalyst. Iron and molybdenum loadings were calculated to be 20.8% and 4.0%, respectively. Fibrils were grown using the procedure described in Example 1. Typical fibril yields were 20-25 times based on catalyst, 120-150 times based on iron. Examination by electron microscopy (SEM and STEM) showed that the fibrils were present primarily as loose, open mats with lesser amounts of combed yarn aggregates. Other embodiments are within the following claims. For example, other suitable support materials include MoO 3 and layered clays, e.g., alumina-, silica-, or magnesia-based clays.

A fibril aggregate that includes a multiplicity of carbon fibrils whose longitudinal axes have substantially the same relative orientation, each of the fibrils characterized as having graphitic layers that are substantially parallel to its longitudinal axis and being free of a continuous thermal carbon overcoat, and a method of preparing such aggregates.

This application is related to application U.S. Ser. No. 08/175,458, entitled "Apparatus For Separating Solids From Fluids", now U.S. Pat. No. 5,417,854. FIELD OF THE INVENTION This invention relates to a novel apparatus for isolating solids from fluids. More particularly, said apparatus comprises an auger, a movable cap and a torque sensor which allows for solids or wet cakes to be separated from liquids under pressure. BACKGROUND OF THE INVENTION For over a hundred years it has been well recognized that naturally occurring processes are inherently mixing processes and that the reverse procedure, unmixing or separation processes, typically creates challenging problems for engineers and the like. Nonetheless, many processes and apparatuses have been developed in order to transform a mixture of substances into two or more products which differ from each other in composition. Conventional techniques which induce precipitation of solids from solutions in order to produce mixtures include crystallization, centrifugation, clarification and separation agent employment. Subsequent to mixture formation, the solids are separated from liquids by typical methods including evaporation, filtration, decanting and absorption. Such methods can be environmentally hazardous since they often require the vaporization and transporting of toxic solvents as well as the employment of expensive reagents. Moreover, known separation devices usually perform at atmospheric pressure or pressures lower than atmospheric and they often require temperature elevation before any solids may be separated from fluids. The instant invention, therefore, relates to a novel apparatus for isolating solids from fluids. More particularly, the apparatus comprises an auger, a movable cap and a torque sensor which allows for solids and liquids to be isolated from one another (batch or continuously) under pressure without employing inefficient, energy intensive and environmentally unfavorable steps. DESCRIPTION OF THE PRIOR ART Apparatuses for isolating solids from solution have been disclosed in the art. In commonly assigned U.S. Pat. Nos. 4,603,194 and 4,634,761, volatilization vessels open to the atmosphere are disclosed. Said vessels comprise feed ports, outlet ports and impellers, wherein polymer solutions are fed into the vessel and heated in order to obtain polymer slurries which are subsequently centrifuged and dried in order to recover solid polymer. Additionally, in commonly assigned U.S. Pat. No. 4,668,768, an evaporation vessel is described. Said evaporation vessel is charged with an organic solvent comprising polymer and an organic anti-solvent wherein a powdery polymer precipitate is recovered subsequent to vaporization. In U.S. Pat. No. 5,306,807, efforts are disclosed for isolating polymers from solutions by subjecting the solutions to carbon dioxide, wherein the disclosure of said U.S. Patent is incorporated herein by reference. Still other investigators have focused on the recovery of solids from solution. In German Patent 0,184,935 polymer resins are isolated from solution by charging a holding tank with a polymer solution and adding carbon dioxide containing fluids. The instant invention is patentably distinguishable from the above-described since, among other reasons, it is directed to an apparatus for isolating solids from fluids wherein said apparatus comprises an auger, a torque sensor and a movable cap which allows for solids and liquids to be isolated under pressure. Moreover, in the instant invention, fluids are defined as liquids, solutions comprising solids and/or gases dissolved therein, suspensions and emulsions. Further, fluids in the instant invention can mean mixtures of miscible or immiscible solvents. SUMMARY OF THE INVENTION Generally speaking, the instant invention relates to an apparatus for isolating solids from fluids in a mixing vessel from a solution or mixture comprising the same. Said apparatus allows for solid and fluid separation without the need for inefficient, energy intensive and environmentally unfavorable steps such as evaporation/volatilization of substantially all liquids (organic solvents) present in the system, the necessary-employment of anti-solvents and the employment of expensive separation/precipitation agents. Further, the instant apparatus may function at a variety of temperatures; however, ambient temperature is often preferred. The needs of the instant invention are met by the above-described novel apparatus which comprises a mixing vessel (closed to the atmosphere) and a barrel which is connected to said mixing vessel. It is often preferred that the barrel is horizontal and perpendicular to said mixing vessel. However, any arrangement which allows for solid particles in the mixing vessel to enter the barrel will work; especially in the case where the solid particles are less dense than the fluid. The mixing vessel typically comprises solution/mixture and gas/liquid component inlets, a particle passage attached towards the back of said barrel, a filter attached to an outlet component and an optional motor driven agitator. The gas or liquid supplied via the gas/liquid component inlet may be either pure gas, pure liquid or gas dissolved in liquid. The barrel comprises a posterior portion, anterior portion and, internally, an auger (fixed in length) with a posterior shaft extending through the posterior portion of the barrel and attached to a first motor drive. Said auger comprises an anterior and posterior end and flights for moving solid particles towards the anterior portion of the barrel. The first motor drive is employed to rotate the auger inside the barrel. Often, the posterior end of the auger is conical and the posterior portion of the barrel comprises an annular seat inserted therein. The posterior annular seat acts as a rest for the posterior conical end of the auger. The posterior annular seat and the posterior conical end of the auger, together, act as a posterior dynamic seal for the barrel. However, it is within the scope of the instant invention to employ any conventional posterior sealing mechanism including those which employ o-rings, compression fittings, graphite packing and magnetic couplings. The anterior portion of the barrel comprises threads, externally. Threaded on said threads of the anterior portion of the barrel is a movable cap. Internally, the anterior portion of the barrel has a groove with an o-ring inserted therein. The movable cap comprises an opening to the atmosphere and an inner section and often comprises, internally and surrounding said opening, an anterior annular seat attached to said inner section. Often, the anterior end of the auger is conical and rests on the anterior annular seat. Together, the anterior conical end of the auger and the anterior annular seat act as an anterior dynamic seal for the barrel. As is the case for the posterior portion of the barrel, it is within the scope of the instant invention to employ any conventional anterior sealing mechanism including those which employ o-rings, compression fittings and graphite packing. It is particularly noted in the instant invention that movable cap means a cap having an inside diameter and internal threads complementary to the outside diameter and external threads on the anterior portion of the barrel such that the cap can be fully tightened or loosened (not as to fall off) on the anterior portion of the barrel. The movable cap is activated (tightened or loosened) by a second motor drive which is regulated by a conventional torque sensor connected to the posterior shaft of the auger and the second motor drive. Additional features and advantages of the present invention will become apparent upon reading the following detailed description and the appended claims with reference to the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which: FIG. 1 is a schematic drawing of a side view of the apparatus of the present invention. It depicts a tightened movable cap and the anterior conical end of the auger resting on the anterior annular seat which prevents particle removal at the anterior portion of the barrel. FIG. 2 is a schematic drawing of a side view of the apparatus of the present invention. It depicts the movable cap loosened and the anterior conical end of the auger away from the anterior annular seat which allows particle removal at the anterior portion of the barrel. FIG. 3 is a schematic drawing of a cross-section of the movable cap of the present invention. It depicts the opening in the movable cap surrounded by the anterior annular seat. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the figures, an apparatus 10 for isolating solids from fluids is shown. The apparatus 10 comprises a mixing vessel 12 and a barrel 14. The mixing vessel 12 comprises a solution/mixture component inlet 16 and a gas/liquid component inlet 18. The mixing vessel 12 further comprises a particle passage 20 attached to said barrel 14, a filter 22 attached to a valve controlled outlet component 24 and an optional motor driven impeller 26. The barrel 14 comprises, internally, an auger 28 having flights 30 and a posterior shaft 32 extending through the posterior portion of the barrel 34 and attached to a first motor drive 36. The first motor drive 36 is employed to rotate said auger 28 inside the barrel 14. The posterior end of the auger 28 is often conical and the posterior portion of the barrel 34 comprises an annular seat 40 inserted therein. The posterior annular seat 40 acts as a rest for the posterior conical end 38 of the auger 28. The posterior annular seat 40 and the posterior conical end 38 of the auger 28, together, act as a posterior dynamic seal for the barrel 14. The anterior portion of the barrel 14 comprises external threads 42. Internally, the anterior portion of the barrel 14 comprises a groove 44 with an o-ring 45 inserted therein. Threaded on said external threads 42 of the anterior portion of the barrel 14 is a movable cap 46 comprising internal threads 47 and an opening to the atmosphere 48, an inner section 50 and internally and surrounding said opening to the atmosphere 48, an anterior annular seat 52 attached to said inner section 50. The anterior end 54 is conical and rests on the anterior annular seat 52. Together, the anterior conical end 54 of the auger 28 and the anterior annular seat 52 act as an anterior dynamic seal for the barrel. The instant invention is not limited to any particular solids or fluids being isolated. If in fact a solution is introduced into the mixing vessel 12 by way of the solution/mixture component inlet 16, the gas being supplied into said gas/liquid component inlet 18 generally induces precipitation of solid from the solution. In this instance, the gas typically dissolves in the solution resulting in solid precipitation, and a motor driven impeller 26 may be employed in order to enhance the gas dissolution. However, if a mixture (solid and liquid) is supplied to the mixing vessel 12 via the solution/mixture component inlet 16, the gas is not employed to induce precipitation in the mixture since solid to be isolated is already present. Moreover, the mixture could, if desired, be directly fed into the barrel without employing the mixing vessel. In all instances, however, it is preferred to supply a gas or liquid component to the mixing vessel 12 via the gas/liquid component inlet 18 since it is preferable for the pressure inside the mixing vessel to be greater than external pressure. Subsequent to charging the mixing vessel 12 with solution/mixture and gas or liquid, solid particles 56 settle to the bottom of the mixing vessel 12 and pass through the particle passage 20 into said barrel 14. The density of the solid particles causes the particles to enter the barrel 14. It is noted that the fluid level 58 remains constant in the mixing vessel 12. This is accomplished by the passage of liquid or liquid and gas under pressure through the filter 22 and into the valve controlled outlet component 24. In the instant invention, a torque is created as a direct result of the rotation of the auger 28 (and inherently its flights 30) and the packing of solid particles 56 towards the anterior portion of the barrel 14 near the movable cap 46. It is noted that when the movable cap 46 is tightened, the anterior conical end 54 of the auger 28 rests on the anterior annular seat 52 attached to the inner section 50 of said movable cap 46 forming the dynamic seal. When the dynamic seal is formed, no solid particles 56 or fluids escape from the barrel 14 via the opening to the atmosphere 48 in the movable cap 46. The torque is felt by said first motor drive 36 and said posterior shaft 32 and it continues to increase as more solid particles 56 pack near the anterior portion of the barrel 14. When the torque felt by the first motor drive 36 and the posterior shaft 32 reaches a selected high, a conventional torque sensor 60 attached to said posterior shaft 32 senses the selected high torque and carries an electrical signal to a second motor drive 62 which actuates the movable cap 46 (causing it to loosen) resulting in a break in the dynamic seal. The dynamic seal is broken since the anterior conical end 54 of the auger 28 is no longer resting on the anterior annular seat 52. This in turn causes solid particles 56 to escape the barrel 14 via the opening to the atmosphere 48 in the movable cap 46. Therefore, in the instant invention, loosening the movable cap 46 means that the movable cap 46 moves away from the anterior conical end 54 of the auger 28 which prevents said anterior conical end 54 of the auger 28 from resting on the anterior annular seat 52 resulting in solid particle 56 escape from the barrel 14. It is noted that there is no limitation with respect to the bulk density of the solid particles 56 recovered; however, said bulk density is often between about 10 to about 30 lbs/ft 3 when polycarbonates are recovered. When said solid particles 56 escape the barrel 14 via the opening 48 in the movable cap 46, the torque felt by the first motor drive 36 and the posterior shaft 32 subsequently reaches a selected low and the conventional torque sensor 60 attached to said posterior shaft 32 senses the selected low torque and carries an electrical signal to said second motor drive 62 which again actuates the movable cap 46; however, in a direction towards the anterior conical end of the auger 54 (thus tightening the movable cap 46). This in turn causes said anterior conical end 54 of the auger 28 to rest on the anterior annular seat 52 which reforms the dynamic seal preventing solid particles 56 from escaping the barrel 14; subsequently causing the process to begin again. Moreover, the o-ring 45 inserted in the groove 44 prevents fluids from escaping the barrel under the movable cap 46. Additionally, solid particles as used herein, are meant to include solid particles and/or wetcakes. Selected high torque is defined as the torque setting selected on the conventional torque sensor 60 which results in the second motor drive 62 loosening the movable cap 46. Selected torque low is defined as the torque setting on the conventional torque sensor 60 which results in the second motor drive 62 tightening the movable cap 46. The second motor drive 62 employed in the instant invention may be any conventional drive unit used in the art that can tighten and loosen the movable cap 46. Often, said second motor drive 62 is mechanical, hydraulic, pneumatic or preferably electromechanical in nature. The following example is provided to further facilitate the understanding of the invention and it is not intended to limit the instant invention. EXAMPLE A 1000 ml mixing vessel 12 equipped with a motor driven impeller 26 may be charged with 200 cm 3 of methylene chloride. CO 2 at 650 psig can be introduced into the vessel and the resulting mixture may be stirred at 1750 rpm until equilibrium is reached. A bisphenol A polycarbonate (BPA) solution comprising 14% by weight polycarbonate and 86% by weight methylene chloride may be pumped into the solution inlet 16 of the mixing vessel 12 at a rate of 50 cm 3 /minute. The mixing vessel 12 may then be continuously charged with CO 2 at 650 psig until polycarbonate precipitates and is collected as solid particles. The solid particles enter the sealed barrel 14 of the apparatus 10 and the first motor drive 36 of the apparatus 10 is started so that the auger 28 rotates. Liquid is removed via an outlet 24 in order to maintain a constant liquid level 58 in the vessel. The solid particles 56 are carried towards the opening to the atmosphere 48 by flights 30 on the auger 28. They collect as a packed column near the opening to the atmosphere 48 of the barrel 14 creating a torque on the first motor drive 36 and the posterior shaft 32 of the auger 28. As a result, the conventional sensor 60 senses the torque and sends a electrical signal to a second motor drive 62 which loosens the movable cap 46 releasing the anterior dynamic seal on the barrel 14. Solid particles 56 subsequently escape the opening to the atmosphere 48 and are recovered and dried.

A novel apparatus for isolating solids or wetcakes from fluids is disclosed. Said apparatus is closed to the atmosphere and comprises a torque sensor and movable cap which allows for solid recovery under pressure without requiring substantial solvent volatilization.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 15/055,626 , filed on Feb. 28, 2016, to be issued as U.S. Pat. No. 9,509,975, which is a continuation of U.S. patent application Ser. No. 14/740,110 , filed on Jun. 15, 2015, now U.S. Pat. No. 9,277,203, which is a continuation of U.S. patent application Ser. No. 13/694,782, filed on Jan. 3, 2013, now U.S. Pat. No. 9,124,877, which is a divisional of U.S. patent application Ser. No. 11/881,617, filed on Jul. 24, 2007, now U.S. Pat. No. 8,390,675, which is a nonprovisional application of U.S. Provisional Patent Application No. 60/833,117 filed on Jul. 24, 2006, wherein U.S. patent application Ser. No. 11/881,617 is a continuation-in-part of U.S. patent application Ser. No. 11/256,497, filed on Oct. 21, 2005, which in turn is a nonprovisional application of U.S. Provisional Patent Application No. 60/621,271, filed on Oct. 21, 2004, wherein all of the U.S. priority applications in their entirety are herein incorporated by reference. BACKGROUND Description of Related Art The use of stereoscopy, in which the user sees left- and right-eye views and forms a three dimensional image through stereopsis, is common in many areas of science, medicine and entertainment. The use of an optical instrument to provide a stereoscopic image of objects to a user's eyes is also common. Optical instruments are used for observation, surveillance, and many other purposes. The optical image generated by an optical instrument is typically viewed through eyepieces. However, the use of eyepieces in optical instrument systems is often problematic. Furthermore, only one observer at a time can view images generated by the optical instrument and the observer can no longer see what is happening in the surrounding environment. In addition, an optical instrument , as such, cannot store images or sequences of images for later playback, process them in special ways, or transmit them to remote viewing sites. There are also situations in which it is desirable to remotely view or record a stereoscopic image of a location or object without involving a person to take the image. Therefore, it is often desirable to use electronic imaging to acquire images of a location, either for direct, real-time observing or for recording Electronic imaging is a preferred method of the television broadcasting, video and movie industries as well. The use of cameras and electronic displays to acquire images is well known in the art, including the use of two cameras and a 3D display to give a stereoscopic image. However the two-camera systems have many disadvantages. Obtaining and maintaining stereoscopic alignment (necessary for comfortable, long-term viewing) can be very difficult when two independent cameras are mounted on or comprise an optical instrument. The cameras generally protrude from the general body of the device and are often mounted in a way that is fragile and prone to breakage. Protruding cameras can also interfere with other apparatuses in the workspace, limiting possible usage configurations. The two-camera systems have generally double the optical instrument and camera knobs and controls, resulting in an unwieldy device difficult to operate by a single user. Dual camera systems generally require numerous mounting parts, resulting in less reliability and more cost than a single, integrated camera. There are also problems with mounting and connecting the cameras to displays or storage media. The use of two cameras requires multiple cables and connectors, resulting in less reliability and more difficult installation than a single cable/connector arrangement of the present invention. The two-camera system also typically requires two camera control units (CCUs) and two storage devices, and requires that they be synchronized for best image quality. This significantly increases the cost of the system. In addition, such cameras do not allow precise positioning of the imaging sensors to each other for best stereopsis and comfortable viewing, particularly when two off-the-shelf cameras are used. Cameras which are wide cannot be easily positioned side-by-side with close spacing. The cameras must be individually focused after mounting, and, should adjustments such as brightness and contrast be needed, each camera must be controlled individually. Where the cameras contain irises, they must also be individually adjusted for each camera, resulting in the potential for unequal amounts of light entering each camera, which can lead to difficult 3D viewing and eyestrain. All these factors indicate that using such a system requires skill and can be very time-consuming. Image processing is also problematic in such systems. The cameras must be electronically linked in some way so that the two image streams are synchronized, creating additional cost and complexity. Even if the data streams are synchronized, generally the shutters are not perfectly synchronized such that the nth pixel from one view was not captured at the same time as the nth pixel from the other view, causing moving objects to show spurious parallax when displayed. Furthermore, the images acquired by the two cameras are generally taken directly to the 3D display device. Therefore, should the user require image processing, storage, transmission, or display on alternative displays, additional processing units are required, creating additional cost and complexity. The cameras used in such two-camera systems also usually conform to the NTSC or PAL video standard, both of which suffer from low resolution, poor color fidelity, and motion artifacts (due to the interlaced nature of the raster scan). Recording and editing recorded content is also problematic with the two-camera system. Recorders don't generally start and end synchronously, so the two tapes or files must somehow be synchronized, resulting in additional effort and expense. Editing may need to be performed twice—once to each file or tape. Information relevant to attempts to address these problems can be found in U.S. Pat. Nos. 4,418,993; 4,583,117; 4,879,596; 4,881,122; 5,164,827; 5,438,386; 6,157,337, and 6,512,892. However, each one of these references suffers from one or more of the following disadvantages: the device or system creates two independent output signals; is not compact; does not provide sufficient image processing, recording, or transmission capability; does not have adequate resolution in real-time for many applications; is cumbersome or is not easily operated by a single user; is large and expensive; more than one operator is generally needed to properly control all of the required functions in order to provide good images; it is difficult to synchronize two separate cameras to the pixel level; two recording devices or image-capturing paths are required, resulting in additional complexity and cost in acquiring and recording the images and editing them as is often desirable; accessory image/data recording systems have a required start-up time prior to recording; uses significant power, requiring large batteries for mobile applications and emitting significant heat that could disturb sensitive environments; is more fragile than a single camera; or does not perform well if either or both of the cameras uses automatic focusing, automatic exposure control or image stabilization control, because such systems or devices heretofore have not been synchronized for the two views from the two cameras; Therefore, the use of optical instrument systems containing electronic cameras, recording devices and display therefore solves some of the eyepiece problems but creates new ones, essentially making them impractical for routine use. SUMMARY Embodiments of the present invention provide improved devices and methods for viewing and recording images and, in particular, stereoscopic images. The embodiments of the invention relate to a compact stereoscopic camera capable of providing visual observation and recording of images of a location. In particular, embodiments of the present invention provide an optical instrument having an integrated Stereoscopic Image Acquisition Device (SIAD) which circumvents the need for, and limitations of, eyepieces. The camera acquires and transfers high-resolution, real-time stereoscopic image data in a single data stream, from stereoscopic still or moving views of a location or object synchronized to the pixel level, to image processing, recording, or display systems which may be included in an integrated handheld device. The device performs the desired functions without protruding elements, numerous cables and connectors, and other additional components, and could be readily operated by a single user. One aspect of the invention is a stereoscopic camera having an optical instrument and a stereoscopic image acquisition device. In one embodiment, the camera contains mechanisms or structures designed to avoid spurious parallax. In another embodiment, the camera contains mechanisms or structures designed to control the effect of varying interpupillary distance (IPD). In yet another embodiment, the camera contains mechanisms or structures designed to control the effects of varying convergence. In a further embodiment, the camera can provide a non-reflected view or desirable orientation of the location. In another embodiment, the camera contains master-slave control of adjustable channels. In yet another embodiment, the camera may be free standing and contains an integrated power source, image processing unit, and storage device. In yet another embodiment, a display mechanism is integrated into the camera. A second aspect of the invention is a stereoscopic camera including master-slave control of adjustable camera channels such that aspects of the views from channels are equalized, providing optimal stereopsis. A third aspect of the invention is a method for acquiring stereoscopic images of a location or object, the method including steps for interactively aligning vergence without producing substantially abrupt transitions in the views used to acquire the stereoscopic images. In one embodiment, alignment could be achieved by a single user. In another embodiment, alignment could be achieved simultaneously with other camera adjustments. In yet another embodiment, the method includes processes for maintaining vertical position equalization in order to prevent spurious parallax between the respective views. A fourth aspect of the invention is a stereoscopic camera in which the functional elements of an optical instrument and a stereoscopic image acquisition device are integrated into a single package. A fifth aspect of the invention is an interactive method for mitigating the effects of camera shake while acquiring stereoscopic images. These and other further features and advantages of the embodiments of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of one embodiment of the invention having a stereoscopic camera system, including the system components and a viewer; FIG. 2 is an expanded perspective view of the stereoscopic camera components of the embodiment shown in FIG. 1 ; and FIG. 3 is a perspective view of one embodiment of the invention containing a deflecting element in addition to stereoscopic camera system components and a viewer. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention provides improved devices and methods for acquiring, viewing and recording images and, in particular, stereoscopic images. Briefly, and in general terms, embodiments of the present invention are directed to an optical instrument having an integrated SIAD device. In particular, embodiments of the present invention provide an optical instrument having an integrated SIAD device which circumvents the need for, and limitations of, eyepieces, and additionally includes numerous features not hitherto associated with optical instruments. In particular, embodiments of the present invention relate to a compact stereoscopic camera capable of providing visual observation of a location. In particular, some embodiments of the present invention provide an optical instrument having an integrated Stereoscopic Image Acquisition Device (SIAD) which circumvents the need for, and limitations of, eyepieces. The camera acquires and transfers high-resolution, real-time stereoscopic image data in a single data stream, from stereoscopic still or moving views of a location or object synchronized to the pixel level, to image processing, recording, or display systems which may be included in an integrated handheld device. The device performs the desired functions without protruding elements, numerous cables and connectors, and other additional components, and could be readily operated by a single user. The following description presents embodiments of the invention representing the modes contemplated for practicing the methods disclosed, including the best mode. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the embodiments of the invention whose scope is defined by the appended claims. Before addressing details of embodiments described below, some terms are defined or clarified. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a , method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). Also, use of the “a” or “an” are employed to describe elements and components of the embodiments of the invention. This is done merely for convenience and to give a general sense of the embodiments of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 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. Furthermore, any definitions used refer to the particular embodiments described herein and are not to be taken as limiting; the invention includes equivalents for other undescribed embodiments. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. As used herein, the term “beam” is intended to mean a rigid member or structure supported at one or both ends, subject to bending forces from a direction perpendicular to its length. A beam can be made flexible in a direction and rigid in others. As used herein, the term “binocular” is intended to mean an optical instrument consisting of two optical paths, each comprising one or more optical components, such as a lens, or combination thereof for focusing a stereoscopic image of a location or object therein on, for example, the eyes of a viewer or on a sensor. A binocular can be used for magnifying a small distant object but can also be used to provide a de-magnified view of a location, for example a wide-angle stereoscopic image of a landscape location. By comparison, a microscope generally is used for magnification of small objects which are close and held attached to a stationary portion of the microscope to which the optical path is focused. A binocular is generally used to observe objects at more varying, farther and random distances. As used herein, the term “camera” is intended to mean a device that consists of one or more lightproof chambers with one or more apertures fitted with one or more in combination lens or other optical component through which the image of an object is projected and focused onto a surface for recording (as on film, for example) or for translation into electrical impulses or data, for display or recording (as for television broadcast, for example). As used herein, the term “camera shake” is intended to mean the effect of unintended vibration and random motion imparted to a camera by the unsteadiness of the holding device, which is generally a user's hands, a vehicle's mounting bracket or an unsteady base. Camera shake appears on a display as a bouncing or vibrating view. As used herein, the term “centration” is intended to mean the accuracy with which the optical axis of a lens in an optical instrument coincides with the mechanical axis of a mounting in the instrument for that lens. Poor centration can cause spurious parallax when optical components are moved relative to one another or to a sensor. As used herein the term “channel” when referring to a stereoscopic camera is intended to mean the components required to acquire a view of a stereoscopic image. One nonlimiting example of a channel consists of a lens, optical path and one or more sensors to acquire the view as data. Channels are typically arranged such that the optical axes are coplanar and may converge at a distant point, and the input optical components are generally side by side. As used herein the term “channel spacing” or “spacing of channels” refers to the distance between the optical paths at the inputs to the input optical components of channels, often objective lenses. Channel spacing may be adjusted in order to change one or more of the views of a location or object, thereby providing a desired perspective of the stereoscopic image formed by the views. As used herein, the term “controller” is intended to mean the component of a system that contains the circuitry necessary to interpret and execute instructions fed into the system. For example an acquisition system may contain an acquisition controller. Representative graphics controllers include without limitation a graphics card, video card, video board, video display board, display adapter, video adapter, graphics adapter, image processing unit or combination thereof. As used herein, the term “de-reflection” refers to reversing the reflecting effect of a deflecting element. If a mirror or other deflecting element is used between the object and a camera, for example to look around a corner, the view can be reversed electronically by reassigning the location of pixels within the views such that the view presented on the display is oriented as if the object was viewed directly. As used herein, the term “electronic mechanisms for adjusting the size of an object” include automatic zoom and digital zoom. As used herein, the term “equalize” or “equalized” is intended to mean to cause to correspond, or be like, in amount or degree as compared, including without limitation to make equal or to compensate for differences. As used herein, the term “equalization of size” refers to having an object appear at the appropriate size to each eye of the viewer. Generally for objects in front of a viewer an object will appear the same size in each eye. As such, in a stereoscopic image it is important that an object appear the same size in each view in order for the viewer to form the best stereopsis. If the object does not appear to be the same size, the size can be equalized by making the size of one view equal to that of the other view of the object to correct the image. As used herein, the term “equalization of vertical position”, vertical referring to the direction perpendicular to the plane of the optical axes of two channels of a stereoscopic camera, refers to making an object appear at the appropriate vertical position to each eye of the viewer. Generally a point on an object is at the same vertical position in each view to avoid spurious parallax which detriments the viewer's stereopsis. If the object does not appear to be at the same vertical position, the position can be equalized by making the position of one view equal to that of the other view of the object to correct the image. As used herein, the term “free-standing” is intended to describe a device which is sufficiently complete in construction such that no additional devices are required for its operation. For example without limitation, a camcorder can be free-standing as it runs on batteries and has a built-in recording system; the user need have no other device to operate it. As used herein, the term “high-resolution” when referring to stereoscopic images is intended to mean at least about 1280 by 720 pixels for each left or right view. It is contemplated that resolutions of three times and eight times this minimum resolution may be implemented depending on the state of technology for sensors and displays and depending on what cost is acceptable. On the other hand, the devices of the present invention may be implemented without limitation with higher or lower resolutions for either one or both of the views. As used herein, the term “image data” is intended to mean data produced by regular array detectors such as CMOS, CCDs and infrared devices. The data structures are created by the data acquisition systems or acquisition controller for use by observers, data reduction systems, and archives. As used herein the term “kinematic relationship” is intended to mean the ability to deduce the motion of points on a device from the knowledge of the motion of other points on the device and the geometry of the device. For example without limitation, if one end of a long lever is lifted, say, 2 inches, it can be deduced from the kinematic relationship that the motion of the midpoint of the lever is about 1 inch. As used herein, the term “lens” is intended to refer to a piece of transparent material (such as, for example, glass) that has two opposite regular surfaces, either both curved or one curved and the other plane, and that is used either singly or combined in an optical instrument for forming an image by focusing rays of light. “Lens” may refer to an individual lens or a plurality of individual lenses acting in combination. As used herein, the term “location” is intended to mean a position or site marked by some distinguishing feature, including without limitation a place, scene, or point therein. As used herein, the term “magnification” is intended to mean the ratio of the size of an image to the size of an object. It can be a relative term because an electronic image of an object imaged with a camera could be displayed on a large or a small display device and hence have different magnifications resulting from identical image data. As used herein, the term “mechanism” is intended to mean a process, technique, device or system for achieving a result. A mechanism may be controlled in a variety of ways, including without limitation mechanically, electromechanically, electrically, or electronically operated mechanisms. As used herein, the term “optical” is intended to mean of or relating to or involving light or optics, including without limitation the use of visible radiation or combinations of visible and non-visible radiation to visualize objects. As used herein, the term “optical component” is intended to mean a part of an optical system which deflects, refracts, restricts, focuses, manipulates, mirrors, modifies, filters or has some other intended effect on a beam of light including without limitation lenses, prisms, mirrors, and beamsplitters. As used herein, the term “optical instrument” is intended to mean any optical instrument capable of generating images including without limitation microscopes, endoscopes, binoculars, and telescopes. As used herein, the term “optical path” is intended to mean the generally central ray in an optical system. Should the system have no central ray then the optical path is the general centerline of the average of all the rays. As used herein, the term “optical device” is intended to mean any device or instrument capable of generating, sensing, capturing, processing, formatting, or storing images or image data. As used herein, the phrase “real time” is intended to mean that the image data is acquired, processed, transmitted, or displayed at a sufficiently high data rate and at a sufficiently low delay that objects on a display move smoothly, for example without user-noticeable judder or latency between object motion and display motion. Typically, this occurs when new images are acquired, processed, and transmitted at a rate of at least about 24 frames per second (fps) and displayed at a rate of at least about 45 fps and when the combined processing of the system has no more than about 1/30 th sec of delay. As used herein, the phrase “single data stream” is intended to mean a combination of more than one individual data streams into a single stream such that a desirable aspect of the data is maintained, such as timing or scale. As used herein, the term “sensor” is intended to mean a device that responds to a stimulus, such as heat, light, or pressure, and generates one or more signals that can be measured or interpreted. As used herein, the term “shutter” is intended to mean a camera component that allows light to enter by opening and closing an aperture. As used herein, the term “spurious parallax” is intended to mean the parallax between views in a stereoscopic image which appears imperfect to the viewer. Vertical parallax of even a small amount results in poor stereopsis. For example, spurious parallax can be caused by non-planar optical axes of channels, unequal magnification in channels, vibration of the camera, distorted or unequal optical paths of channels and similar imperfections. As used herein, the term “stereoscopic image” is intended to mean a single image consisting of at least two views, one corresponding to a left-eye view, i.e. the left view, and one corresponding to a right-eye view, the right view. As used herein, the term “stereoscopic image acquisition device” is intended to mean a device capable of acquiring stereoscopic images from an optical instrument, or the imaging components thereof. Embodiments of the device acquire and transfer high-resolution, real-time image data from stereoscopic still or moving images to image processing, recording, or display systems. Embodiments of the device can perform the desired functions without protruding elements, numerous cables and connectors, and other additional components such as eyepieces, and can be readily adapted for use with a variety of optical instruments. Embodiments of the device may incorporate the functionality of related mechanisms, controllers, sensors, and processors in a non-limiting manner. As used herein, the term “telescope” is intended to mean an instrument designed for the observation of remote objects, typically comprising an input optical component at the distal end of a tube and one or more optical components at the proximal end, such tube providing a path for light beams and possibly a path to change the spacing of optical components and hence focus or magnification, including without limitation a tubular optical instrument for viewing distant objects by means of the refraction of light rays through a lens or the reflection of light rays by a concave mirror. As used herein, the term “vergence” is intended to mean the ability of the optical axes of the eyes or of an optical instrument to rotate toward or away from each other to remain pointed at an object as it approaches or moves away. As used herein, the term “view” is intended to mean extent or range of vision. Attention is now directed to more specific details of embodiments that illustrate but not limit the invention. General Description One embodiment of the invention provides a stereoscopic camera that includes a Stereoscopic Image Acquisition Device (SIAD) having an acquisition controller and an optical instrument that may be attached to or built into the SIAD. FIGS. 1-3 illustrate three embodiments of the invention having a variety of components and applications. FIG. 1 illustrates one embodiment of the Stereoscopic Camera and System and its components, and a viewer. The components are labeled as outlined below: 1 . Object in a location being imaged; 2 . Optical axes; 3 . User interface, in this embodiment a pistol-grip with controls; 4 . Stereoscopic Image Acquisition Device (SIAD); 5 . Optical instrument, in this embodiment it is a binocular having two telescopes that is attached to the SIAD; 6 . Stereoscopic display, in this embodiment an autostereoscopic flat panel; 7 . Image processing unit (IPU), in this embodiment a display controller is included in the IPU; 8 . Viewer, in approximate viewing position in this embodiment to see both object and 3D image; and 9 . Image of object in location, appearing in 3D to the viewer. FIG. 2 shows a close-up of several components of the embodiment shown in FIG. 1 which are labeled as outlined below: 2 . Optical axes; 3 . User interface, in this embodiment it is a pistol grip with trigger for image capture and thumb-operated joystick for other input functions; 4 . Stereoscopic Image Acquisition Device. In this embodiment the connections (not shown) from sensors to acquisition controller are flexible circuits, allowing mutual movement between sensors and acquisition controller; 5 . Optical instrument, in this embodiment is a binocular having two telescopes, ( 5 a ) and ( 5 b ) respectively; 6 . Stereoscopic display, in this embodiment for images and user interface; 7 . IPU; in this embodiment a display controller is included in the IPU; 10 a and 10 b. Means to adjust the convergence of the optical axes, in this embodiment it is a flexing beam ( 10 a ) with a manually-driven screw ( 10 b ); 11 a and 11 b. Means to adjust the interpupillary distance (IPD), in this embodiment it is a slider traveling on a rail ( 11 a ), controlled by an electromechanical actuator ( 11 b ); 12 . Means to adjust the vertical alignment of the cameras' images, in this embodiment it is an actuator-driven screw; and 13 . Battery pack. Components In one embodiment, the invention provides a stereoscopic camera system that includes a Stereoscopic Image Acquisition Device 4 (SIAD), an optical instrument 5 that may be attached to or built into the SIAD, and a display mechanisms for displaying stereoscopic images 6 generated by the optical instrument and SIAD. In yet another embodiment, the system may include an image processing unit 7 (IPU). In another embodiment, the system may include a battery or other power source 13 to provide power to the system. Further embodiments may contain no SIAD but may contain other components to perform similar functions. The image processing unit 7 as well as the display 6 and a battery 13 (to provide power) may be attached to the device and integrated into a housing, resulting in a complete, integrated, one-piece device that provides all the necessary functionality including: mechanisms for (1) forming a stereoscopic electronic image of an object or location, (2) processing such image data and (3) displaying a magnified, unmagnified, or demagnified stereoscopic image of the object or location, in a desired orientation and condition (e.g. not inverted or reflected, or in any orientation desired by the user), in a convenient position on the stereoscopic display for the viewer, in real time, and in a device which could be portable. In other embodiments, some or all of the functions of the IPU can be built into circuitry, firmware and software inside the SIAD or elsewhere in the system, such that a separate IPU component may not be required, possibly reducing the size and cost of the system. In yet other embodiments, the one-piece device could be handheld in its use. In further embodiments, the display could be mounted separately with a tethering data cable or wireless link to the SIAD or IPU. In one embodiment, the display could be mounted to the user, facing the user's view, such that his hands can be free to steer and operate the device or perform other tasks while observing the image on the display. An additional advantage of such a system is that the user can possibly see the displayed image at the same time as his peripheral vision allows him to see the rest of the location or surroundings, or vice-versa. Additionally. the system could have the display mounted directly on a handheld device that may be the SIAD, to accomplish a similar result. In these or other embodiments the display, or one or more additional displays connected via a “splitter” device, could be mounted such that multiple viewers could see the displayed image. Image Processing Image processing could be performed on the data to reduce the perceived effect of camera shake on the viewed stereoscopic image. Time sequential data from both left and right channels in combination could be used to calculate corrections of the data to negate the shake effect of both channels, providing image stabilization for the entire stereoscopic image for example, or to otherwise cause a desired effect. Because the electronic corrections can be calculated knowing the kinematic relationship between the optical axes and because the data from the sensors is synchronized with each other the proper corrections can be applied to the stereoscopic image. This is advantageous as compared to the prior art, which applied the corrections to the views separately and asynchronously, resulting in spurious parallax of the stereoscopic image. Alternatively the corrections could be applied to one or more actuation mechanisms to alter the optical path or paths, such that the image is corrected when it arrives at the sensor. Data from both left and right channels could be used to calculate corrections to the sensor exposure parameters or corrections to the data itself to optimize the stereoscopic image and to balance the left channel with the right, providing simultaneous exposure or gain control for example. One embodiment of this could involve a simultaneous baseline setting of the two channels to give equal image characteristics, for example performing white balance simultaneously. Image processing to compress or encode the data could be done to the single data stream or to one or both streams prior to their combination. Displays In these and other embodiments of the current invention, the stereoscopic display could be of any type as described in the related U.S. Patent Application Ser. Nos. 60/762,577, 60/833,117, and U.S. patent application Ser. Nos. 11/256,497 and 11/881,617 that can be further applicable to embodiments of this invention. In embodiments where the user looks slightly downward to see the display but looks up over the display to see the location or object being imaged, and where the display is of a type requiring the user to wear spectacles to see the image stereoscopically, it could be advantageous for the spectacles to be constructed like “reading glasses” whereby looking over the active portion of such spectacles the user has an unobstructed view of the location. Alternatively, left-right stick-on films made from polarizers, retarders or other materials required for stereoscopic viewing of the 3D display, for viewers wearing other glasses, or polarized sunglasses, could be used. A graphic on the film could indicate proper orientation. A permanent or non-permanent adhering method could be used. Another embodiment may have a display that could be switched from displaying either left or right or both views. Another embodiment may have a display that presents either or both views together and has no provision for stereopsis. Storage In other embodiments one or more Hard Disk Drives (HDD), Digital Video Disks (DVD), solid-state or other similar data storage devices (SD), could be included in the IPU or elsewhere for storage, further processing and playback of images. Because the SIAD inputs, processes and displays images in generally real-time (as observed by a user), the SD interface circuitry could be constructed such that images can be stored essentially instantaneously, with no perceived latency after a start trigger has been activated. This has previously been a problem with digital cameras, whereby a shutter button is pressed but the image is not taken until after a noticeable delay. In some embodiments, the file structure may be split into parallel channels such that the bandwidth of data is split to allow that flowing to each SD to be within the SD's transfer rate. In other embodiments, the storage system could make the actual recording of the images on the SD with a delay from when they are captured in system volatile memory. In yet other embodiments, streaming full-motion stereoscopic image data continuously through the SD system, such that there exists some quantity of image data previously stored, upon the occurrence of an event desirable to be viewed but unanticipated, would allow a viewer to review such previously-stored stereoscopic images to view the event after its occurrence. Stereoscopic image data could be updated continuously or in some other manner to, for example, provide a time-lapse stereoscopic recording of an event that occurs slowly. In embodiments where the stereoscopic image data is a single stream, additional synchronization may be unnecessary, resulting in a simpler system, both in storing images and playing them back. Such a system generally has the same data integrity for both the left and right views of images, as opposed to dual-data-channel systems in which either channel may have defects that could spoil the stereoscopic image. Additionally, such a system could also be made redundant and fail-safe, and this could be done more easily to avoid any image data degradation. Such a system could use SDs that generally have low or no recurring costs associated with re-saving newer image data over old. The SD, or its storage media, could be removable, replaceable or expandable, with power on or off. The SD could be of low power such that it could be included in a battery-operated embodiment. The SD could be of low size and weight such that it could be included in a handheld embodiment. The SD could be of sufficient robustness such that it could be included in an embodiment intended for severe-environments. Lenses Lenses or other optical components of the camera and their mounting could be such that interchangeable lenses could be used. Such lenses could be capable of focusing light of infrared, UV or visible wavelengths or combinations thereof. The camera could use two lenses, one for each L/R channel, or a single lens with an optical path switching device such as a shuttering system and beamsplitter or a combination of these. For underwater or similar applications, a system wherein the lenses could contact the water directly and there is a seal for the electronic portion of the SIAD could be used. Furthermore, the internal volume of the sealed portion of the SIAD, possibly including the lenses, could be minimized and securely sealed such that no additional outside housing would be required for use underwater, resulting in a small overall size and weight and easier use. Yet further there could be a tether, thus forming a completely, possibly permanently sealed camera head with a cable, optical fiber or wireless link to the IPU or Display. Such sealing could be potting compound. The lenses could also be parabolic mirrors to focus directly on the image sensors such as, for example, lenses useful for an IR imaging device with no IR glass optics. Alternatively, lenses could be focused automatically and/or together as described in the referenced patent applications. In addition, the lenses could be small to be mounted closely together to make a small inter-pupillary distance. Convergence In embodiments having two optical axes, these axes may be parallel, they may converge at some point distant from the camera or they may be adjustable to converge at any point from a close distance to infinity or to diverge. To allow relative motion of the sensors in embodiments where one or more of the sensors can be moved to move the optical axes, the sensors could be connected to the acquisition controller with flexible circuitry, which may be shielded, to allow relative motion while maintaining bandwidth and suppressing noise. Convergence could be adjusted by use of a mechanism with an actuator to deflect either or both of the sensors' mounting and their respective lens and axis. Alternatively the mechanism could move an optical element, for example a wedge lens, to deflect one or both axes. The mechanism could be comprised of a hinge or a flexing beam of metal, plastic or other suitable material. The actuator could be a manual screw or motorized leadscrew or cam system, or other mechanical or electromechanical device. The control of the actuator could be designed to be operated by the camera user while shooting. The control could be a knob or switch that could also be a handle for one hand. The control could also be a pistol grip device where the user squeezes or activates a lever or wheel to control convergence adjustment. Adjustable stops or detents in the mechanism could be incorporated to aid the user to achieve their desired convergence effect. Convergence could be automated to the autofocus or other aspects of the camera. The IPU, for example, could be programmed to recognize some moving feature and follow it with convergence. There could be a second flexure or mechanism to adjust the axes to be coplanar, known in the art as vertical alignment. Embodiments of the camera or camera systems may also contain a convergence mechanism such that the user can change the convergence as the location or object is being observed and/or recorded. In such embodiments the convergence mechanism can be constructed such that it causes a continuous change in convergence, a smooth transition that is without abrupt changes in the views. The convergence device and system described herein could also be used with two separate cameras and camera systems, for example, without the use of the SIAD. Inter-Pupillary Distance (IPD) In some embodiments having two optical axes, it may be desirable to change the distance between the axes as measured at the camera, known in the art as the IPD. This could be done by use of a mechanism such as a beam that moves one sensor and its respective lens and housing away from the other sensor, generally perpendicular to the optical axes, that movement taking place in the plane of the axes. A clamp could be used to manually secure the sensor housing along a beam in the desired location to achieve the desired IPD. Such a beam could also be used to adjust convergence by flexing or deflecting. Alternatively the IPD could be adjusted by use of a mechanism with an actuator to move either or both of the sensors and their respective lens and axis. Such an embodiment could be designed to accommodate interchangeable lenses including without limitation wide angle or telephoto lenses for either or both optical channels. Zoom Zoom is known in the art as changing the magnification of an optical channel while a location is being observed. Zooming “in” is generally increasing the magnification and zooming “out” is generally decreasing the magnification. Zooming can be performed manually through the use of a mechanism or automatically by sending an electronic signal to an electromechanical actuator. Either technique causes, for example, changes in the axial spacing between or shape of optical elements. Generally it is desirable to have zooming performed such that abrupt changes in views do not occur. The mechanism could be geared to drive rotational cam devices that appropriately change the spacing between optical elements, and hence the magnification, in each optical path simultaneously. The mechanism could be mechanical or electromechanical. Digital zoom is an electronic method to present a similar effect of increasing magnification to a viewer of an electronic display. It is typically implemented by causing a subset of the pixels within the data representing a view to be expanded in order to represent the entire data set representing the view. In this approach, additional pixels are fabricated from adjacent pixel data and interspersed between the original pixels to form a view having generally the same number of pixels as the original view. Alternatively, digital zoom can be implemented by choosing a subset of the pixel cells illuminated by the channel optics on a sensor, to form the data representing the view from the sensor of the channel. The embodiments of the invention may also contain electronic mechanisms to cause digital zoom to be applied to two channels simultaneously. Alternatively, zooming could be done on a master-slave basis whereby the master view's (the right view in this embodiment) magnification is set as desired, and the slave view's (the left view in this embodiment) zoom is automatically controlled to match the master. Such control could use the image data to calculate the proper control parameters, for example by measuring the number of pixels between certain features common in each L/R view and attempting to equalize them, and could be a function of the IPU or acquisition controller. The zoom device and system described herein could also be used independently with two separate cameras and camera systems, for example, without the use of the SIAD. Controls In some embodiments the controls and functions could enable the device to be operated by a single person, remotely or automatically. Control of one or more of the system's functions could be achieved through one or more separate user interface devices used in combination, including without limitation, pushbuttons or other switching devices, a touchpad screen (separate or attached or a part of the 3D display), a joystick, pistol-grip control device, wheel, lever, mouse or similar device controlling the system that provides user feedback on the 3D display screen or on another screen or output indication device. Such user interface and feedback could be stereoscopic to enhance effectiveness. Such controls could operate remotely from the device via a wireless link or over an interface. Communication Communication, including transmittal of image data, and additional control of a system of these embodiments could be performed thru an external interface, including without limitation a network, USB, “firewire”, cameralink or custom designed interface or port, to other devices or to a network. Measurements Capture of the stereoscopic image data could include the capability to make measurements in three dimensions, x-y-z, z being into/out of the image plane, using the parallax data between left/right views of any point common to both views, to calculate the z dimension. Furthermore, it may be desirable to calculate the location of points with respect to a coordinate system. An embodiment could include a component for determining the location of the stereoscopic camera with respect to the desired coordinate system, for example a GPS receiver, whereby the coordinate system is earth's latitude, longitude and altitude. In addition the embodiment could include a component for determining the direction of the z dimension with respect to the coordinate system, for example an electronic compass and/or an azimuth indicator. The location of points in the stereoscopic image can then be calculated with respect to the coordinate system. Quantization error of such a system could be reduced by networking more than one system viewing the desired points from different camera locations and averaging their calculated locations of the desired points. An embodiment could include a pan-tilt-zoom mechanism and such mechanism could be equipped with, for example, position indication devices such that the direction of the z dimension could be changed and the new direction calculated with respect to the desired coordinate system. Deflecting Element FIG. 3 illustrates one embodiment of the Stereoscopic Camera and System containing a deflecting element, system components, and a viewer. The components are labeled as outlined below: 1 . Object in a location being imaged; 2 . Optical axes; 4 . Stereoscopic Image Acquisition Device; 5 . Optical instrument, in this embodiment is a binocular with two telescopes; 6 . Stereoscopic display, in this embodiment an autostereoscopic flat panel. 8 . Viewer, in approximate viewing position in this embodiment to see 3D image; 9 . Image of object in location, appearing 3D to the viewer; 14 . Deflecting element, in this embodiment a flat mirror, mounting not shown; and 15 a - 15 c. Wall ( 15 a ) between harsh environment ( 15 b ) and non-harsh environment ( 15 c ); wall is shown in cutaway. 16 . Pan-tilt-zoom mechanism for changing the direction and/or magnification of the camera. In this embodiment, a deflecting element 14 can be placed in the optical path 2 between the object being imaged 1 and the input optical component of the optical instrument 5 . A system with a deflecting element 14 could be used, as a nonlimiting example, to see around corners or to protect the camera or camera system by exposing only the deflecting element 14 to an environment unsuitable for the camera 15 b while keeping most of the system in a safe environment 15 c, protected from the unsafe environment 15 b by, for example, a suitable type of wall 15 a. Electronic mechanisms can be utilized to de-reflect the views or the stereoscopic image such that the viewer 8 observes an image 9 of the location or object as if it was not reflected by the deflecting element. Alternatively, the deflecting element can be adjusted to provide other desirable orientation. The embodiments and examples set forth herein, including the best mode known to the inventor for carrying out the invention, were presented in order to best explain embodiments of the present invention and its practical application and to thereby enable those of ordinary skill in the art to make and use embodiments of the invention. However, those of ordinary skill in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the teachings above without departing from the spirit and scope of the forthcoming claims. Furthermore, embodiments of the present invention are also applicable to many other types of optical instruments.

Embodiments of an apparatus for acquiring, storing, transmitting and displaying stereoscopic images are disclosed. Some of the benefits of embodiments of this apparatus include simultaneous left/right view acquisition, transmitting and displaying images from a stereoscopic camera, stereoscopic digital zooming wherein a subset of pixels is displayed, pan-tilt-zooming of the apparatus, and interactive adjustment of images. Embodiments of the disclosed apparatus are capable of producing real-time, stereoscopic image data from various illumination wavelengths, coupling to other optical instruments, changing sensor exposure parameters, storing a stereoscopic single data stream, and selectively adding a filter component.

FIELD OF THE INVENTION The present invention relates generally to micromanipulation technology and, more particularly, to an active micro-force sensor for use in micromanipulation. BACKGROUND OF THE INVENTION Efficient assembly processes for micro devices have not been developed, partially because, at the micro-scale, structures are fragile and easily breakable. Typically breakage at the micro-Newton force range cannot be reliably measured by most existing force sensors. So far the most straightforward and flexible operation methods run in an open loop format using a microprobe to physically manipulate the micro device. This method can be inherently risky without an on-line safety micro force regulation. As a result, this approach decreases overall yield and drives up the cost of micro devices. For these reasons, research into automating the micromanipulation processes have focused on micro force sensing and related control techniques. In micro force sensing, cantilever beams are the most frequently implemented sensor structure type depending on its highly sensitive factor, and either static or dynamic operation mode. However, cantilever-based sensors introduce significant limitations for micro-force measurements during micromanipulation. First, the cantilever-based sensors have a relatively flexible structure which causes inherent difficulties with accurate manipulation of micro devices. Second, such sensors exhibit only a small dynamic range for maintaining high accuracy. To overcome these limitations, the present invention proposes an innovative active micro-force sensor based on the bilateral mechanical-electrical behaviors of piezoelectric films. SUMMARY OF THE INVENTION In accordance with the present invention, an improved active micro-force sensor is provided for use on a micromanipulation device. The active micro-force sensor includes a cantilever structure having an actuator layer of piezoelectric material and a sensing layer of piezoelectric material symmetrically bonded together. When an external force is exerted on the sensor tip, the sensor beam deforms and an applied force signal is detected by the sensing layer. The applied force signal is then fed back to the actuating layer of the sensor via a servoed transfer function or servo controller so that a counteracting deformation can be generated by the bend moment from the servoed actuating layer to quickly balance the deformation caused by the external micro-force. Once balanced, the sensor beam comes back to straight status and the tip will remain in its equilibrium position, thus the sensor stiffness seems to be virtually improved so that the accurate motion control of the sensor tip can be reached, especially, at the same time, the micro-force can also be obtained by solving the counteracting balance voltage applied to the actuating layer. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are illustrations of two exemplary active micro-force sensors in accordance with the present invention; FIG. 2 is a schematic of an exemplary circuit for interfacing with the micro-force sensor of the present invention; FIGS. 3A-3J are illustrations of the active micro-force sensor having different patterned electrode layers; FIG. 4 is a block diagram of an active sensing and balance servo system for the micro-force sensor of the present invention; FIGS. 5A and 5B are graphs illustrating the frequency response of the Va/Vs transfer function by simulation and experiment, respectively; and FIG. 6 depicts an exemplary three-dimensional active micro-force sensor in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B illustrates an active micro-force sensor for use on a micromanipulation device. The force sensor 10 is comprised of a rigid contact tip 12 which extends outwardly from a cantilever 14 . The cantilever 14 is in turn coupled to an end of a micromanipulator 16 . It is readily understood that the contact tip 12 may have different shapes depending on the applicable micromanipulation tasks. In accordance with the present invention, the cantilever 14 is a composite structure having at least two layers 22 , 24 made from a piezoelectric material (e.g., polyvinylidene fluoride (PVDF) or lead zirconate titanate (PZT)). In operation, the top layer 22 acts as a balance actuator, while the bottom layer 24 works as a sensing device as will be further explained below. In FIG. 1A , the two layers 22 , 24 are bonded directly together using an insulating, waterproof, high strength, and elastic adhesive (e.g. Loctite® Super Glue Gel, Epoxy Gel or RTV Silicone) or other known bonding technique (double side thin glue tape). In this exemplary embodiment, the two piezoelectric layers are in the form of a rectangular plate. However, it is readily understood that other types of materials as well as other suitable shapes for the piezoelectric layers are within the scope of the present invention. To provide an insulator between the layers 22 , 24 , it is envisioned that a thin support layer 26 may be interposed between the two outer piezoelectric layers 22 , 24 as shown in FIG. 1B . The support layer 26 is preferably made from a polyester material with the function of electrostatic shielding, but other types of thin, elastic, electrostaticity-shielding, and insulating materials are also within the scope of the present invention. Again, the piezoelectric layers 22 , 24 are preferably bonded to each side of the support layer 26 . Principles behind an active micro-force sensor having a composite cantilever structure are further described below. Assuming the geometry of the cantilever is much wider and longer than its thickness, the strain s y along the width of the beam can be assumed to be zero. Based on piezoelectric transverse effect, the unit piezoelectric equation is (without considering the inverse piezoelectric affection and pyroelectric effects): D 3 ( r,t )= d 31 σ s ( r,t )   (1) where D 3 (r,t) is the normal electric displacement of a PVDF film, d 31 is the transverse piezoelectric coefficient and σ s (r,t) denotes the unit stress of the surface of the PVDF sensing layer along beam length. The surface area polarization gives a charge Q s (t) across the PVDF sensing layer active surface area A (covered by electrode): Q s ⁡ ( t ) = ∫ D 3 ⁡ ( r , t ) ⁢ ⅆ A = ∫ ∫ A ⁢ D 3 ⁡ ( r , t ) ⁢ ⁢ ⅆ y ⁢ ⅆ r . ( 2 ) Using the mechanics of materials for cantilever beam, as shown in FIG. 1B , the unit stress on the surface of the PVDF sensing layer 24 can be obtained if the external load f c (t) acts at the sensor tip σ s ⁡ ( r , t ) = ⁢ - cE s ⁢ ∂ 2 ⁢ ω s ⁡ ( r , t ) ∂ r 2 ≐ ⁢ f c ⁡ ( t ) ⁢ ( L - r ) ⁢ c I + f c ⁡ ( t ) ⁢ L 0 ⁢ c I ( 3 ) Notice that since a three-layer composite beam is employed (omitting the effect of thin electrode layers at the top and bottom surfaces of PVDF layers), I will be the moment of the transformed cross section of the composite beam. The neutral axis c n of the composite beam passes through the centroid of the transformed cross section. c is the distance between the middle of the PDF sensing layer and the neutral axis c n of the composite beam. ω s (r,t) is the elastic deflection of the flexible active composite beam caused by the micro force f c (t) at the sensor tip, and 0≦r≦L. Here, the neutral axis of the composite beam can be obtained by c n = WH s ⁢ c s + E m E s ⁢ WH m ⁢ c m + WH a ⁢ c a A T . ( 4 ) where E s =E a , E m are Young moduli of the two PVDF layers 22 , 24 and the polyester film, respectively. c s , c a , and c m are the distances of centroid axes of the two PVDF layers 22 , 24 , and the polyester layer 26 with respect to the base axis of beam, respectively. H=H s +H m +H a is the thickness of the whole composite beam. A T is the total area of transformed cross section as follows: A T = WH s + E m E s ⁢ WH m + WH a . ( 5 ) Then, I, which is around the neutral axis, can be determined by I = WH s 3 12 + E m E s ⁢ WH m 3 12 + WH a 3 12 + WH s ⁡ ( H m 2 + H s 2 ) 2 + WH a ⁡ ( H m 2 + H a 2 ) 2 ( 6 ) Since generation of charge is the same along the width of PVDF (s y =0), we can rewrite equation (2) as: Q s ⁡ ( t ) = ∫ 0 L ⁢ ⁢ ⅆ 31 ⁢ σ s ⁡ ( r , t ) ⁢ W ⁢ ⅆ r = - cE s ⁢ d 31 ⁢ W ⁢ ∂ ω s ⁡ ( r , t ) ∂ r ⁢ ❘ 0 L = d 31 ⁢ A ⁡ ( L 0 + L 2 ) ⁢ c I ⁢ f c ⁡ ( t ) . ( 7 ) Continually, a simplified and effective equivalent circuit model of a capacitor C P can be used to represent the model of the PVDF sensing layer 24 . The output voltage V s (t) of the PVDF sensing layer 24 caused by the micro force can be described by V s ⁡ ( t ) = Q s ⁡ ( t ) C P . ( 8 ) By Laplace transformation, the electrical transfer function of the sensing layer is given as: V s ⁡ ( s ) = Q s ⁡ ( s ) C P . ( 9 ) To find the dynamic relationship between the sensing output V s and the micro force f c acting at the senor tip, we first describe a dynamic model of the flexible PVDF active sensor illustrated in FIG. 1B . Here, the partial differential equation describing the elastic deflection of the flexible composite PVDF sensor is a Bernoulli-Euler equation with an additional term due to the external force and moment. The equation is given by: EI ⁢ ∂ 4 ⁢ ω s ⁡ ( r , t ) ∂ r 4 + ρ ⁢ ⁢ A ⁢ ∂ 2 ⁢ ω s ⁡ ( r , t ) ∂ t 2 = ⁢ f c ⁡ ( t ) ⁢ δ ⁡ ( r - L ) + ⁢ f c ⁡ ( t ) ⁢ L 0 ⁢ ∂ ( δ ⁡ ( r - 0 ) - δ ⁡ ( r - L ) ) ∂ r ( 10 ) where E, I, L and ρ represent the Young's modulus, inertia moment, length of beam, and linear mass density of the composite beam. Assuming that EI=E a I a +E m I m +E s I s is the flexural rigidity of the active beam and pA=ρ a A a +ρ m A m +ρ s A s is mass per unit length of the active beam. f c (t) is the external force acting at the free end of beam, which can be detected by the PVDF sensing layer 24 . δ(.) denotes the Dirac delta function. The boundary conditions for the above equation are: ω s ⁡ ( 0 , t ) = 0 ( 11 ) EI ⁢ ∂ ω s ⁡ ( o , t ) ∂ r = 0 ( 12 ) EI ⁢ ∂ ω s 2 ⁡ ( L , t ) ∂ r 2 = f c ⁡ ( t ) ⁢ L 0 ( 13 ) EI ⁢ ∂ ω s 3 ⁡ ( L , t ) ∂ r 3 = f c ⁡ ( t ) ( 14 ) By using the modal analysis method, we assume that the deformation of the beam have infinite shape modes, then the deflection ω s (r,t) can be expressed as an infinite series in the following form: ω s ⁡ ( r , t ) = ∑ i = 1 ∞ ⁢ Φ i ⁡ ( r ) ⁢ q si ⁡ ( t ) ( 15 ) where Φ i (r) are the eigenfunction satisfying the ordinary differential equation and q si (t) are the modal displacements caused by the micro force. Then the deflection mode shapes are assumed to be: Φ i ( r )= C 1 sin(α i r )+ C 2 cos(α i r )+ C 3 sin h (α i r )+ C 4 cos h (α i r )  (16) Substituting the above equations (15) and (16) into the boundary conditions (11)˜(14) and taking advantage of the orthogonality conditions, ∫ 0 L ⁢ Φ i ⁡ ( r ) ⁢ Φ j ⁡ ( r ) ⁢ ⁢ ⅆ r = δ ij ⁢ ⁢ { i = j , δ ij = 1 i ≠ j , δ ij = 0 ( 17 ) where δ ij is the Kronecker delta function, the mode shapes of this cantilever beam are found to be in the form: Φ i ( r )= C r [ cos(α i r )−cos h (α i r )+ k L (sin(α i r )−sin h (α i r ))]  (18) where C r =C 2 , C 2 ≠0 is a constant, k L = sin ⁡ ( α i ⁢ L ) - sin ⁢ ⁢ h ⁡ ( α i ⁢ L ) cos ⁡ ( α i ⁢ L ) + cos ⁢ ⁢ h ⁡ ( α i ⁢ L ) and α i are the infinite set of eigenvalues yielded by 1+cos(α i L )cos h (α i L )=0  (19) and also, the natural frequencies a; of the sensor beam correspond to the α i by ω i = α i 2 ⁢ EI pA ( 20 ) In order to determine the dynamics of the system, we use Lagrange's equation of motion by ⅆ ⅆ t ⁢ ∂ ( E sk - E sp ) ∂ q . si - ∂ ( E sk - E sp ) ∂ q si = Q i . ( 21 ) Here, E sk is the kinetic energy, E sp represents the potential energy and Q i is the generalized nonconservative forces related to the external micro force. They are E sk = 1 2 ⁢ ∫ 0 L ⁢ ω . s ⁡ ( r , t ) 2 ⁢ ρ ⁢ ⁢ A ⁢ ⁢ ⅆ r ( 22 ) E sp = 1 2 ⁢ ∫ 0 L ⁢ EI ⁢ ⁢ ω s ″ ⁡ ( r , t ) 2 ⁢ ⁢ ⅆ r ⁢ ⁢ Q i = f c ⁡ ( t ) ⁢ Φ i ⁡ ( L ) + f c ⁡ ( t ) ⁢ L 0 ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ( 23 ) where a prime indicates the derivative with respect to position and a dot denotes the derivative with respect to time. Using the Lagrange's equation of motion (21) and orthogonality conditions (17) and (20), we have the differential equation corresponding to each shape mode of the sensor beam to be EIα i 4 q si ( t )+ρA{umlaut over (q)} si ( t )= f c ( t )Φ i ( L )+ f c ( t ) L 0 [Φ′ i ( L )−Φ′ i (0)]  (24) Then by the Laplace transformation of the above equation, the dynamic relationship between the modal displacements q si (s) and the external micro force is given as q si ⁡ ( s ) = f c ⁡ ( s ) ⁢ ( Φ i ⁡ ( L ) + L 0 ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ) ρ ⁢ ⁢ A ⁡ ( s 2 + ω i 2 ) . ( 25 ) Based on equations (7) and (9), since ω s (r,s)=Σ i=1 ∞ Φ i (r)q si (s), by Laplace transform of equation (7), Q s (s) can be represented as Q s ⁡ ( s ) = ⁢ - cE s ⁢ d 31 ⁢ W ⁢ ⁢ ω s ′ ⁡ ( r , s ) ⁢ | 0 L = ⁢ - cE s ⁢ d 31 ⁢ W ⁢ ∑ i = 1 ∞ ⁢ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ q si ⁡ ( s ) ( 26 ) Substituting equation (26) into equation (9), then we have V s ⁡ ( s ) = C s ⁢ ∑ i = 1 ∞ ⁢ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ q si ⁡ ( s ) . ( 27 ) where C s = - cE s ⁢ d 31 ⁢ W . C p Subsequently, by combining equations (25) and (27), we have the dynamic sensing model, which denotes the relationship between the output voltage V s of PVDF sensing layer 24 and the external micro force f c at the sensor tip as follows: V s ⁡ ( s ) f c ⁡ ( s ) = C s ⁢ ∑ i = 1 ∞ ⁢ { [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ Φ i ⁡ ( L ) ρ ⁢ ⁢ A ⁡ ( s 2 + ω i 2 ) + L 0 ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 ρ ⁢ ⁢ A ⁡ ( s 2 + ω i 2 ) } . ( 28 ) To achieve the sensing voltage V s , the PVDF sensing layer 24 is electrically coupled to a sensing circuit. In an exemplary embodiment, the sensing layer 24 is interfaced with a PCI-DAS4020/12 analog/digital input/output board (Measurement Computing Co.) using the electronic buffer circuit as illustrated in FIG. 2 . The buffer circuit is constructed using a chopper stabilized operational amplifier TC7650C (Microchip Co.) with a high input impedance 10 12 Ω and low bias current 1.5 pa (or alternatively ultra low bias current operational amplifiers AD549 (Analog Devices Co.) and OPA111 (Texas Instruments). Thus, the circuit is used to buffer the open circuit voltage V s of the sensing layer. Resistor R in >10 9 Ω provides a DC current path. The circuit output V so is a high pass filtered approximation of the voltage V s and can be sampled by the board which is in turn passed on to a PC. The transfer function between V so and V s can be represented as: V so ⁡ ( s ) V s ⁡ ( s ) = sR in ⁢ C p 1 + sR in ⁢ C p ︸ C b . ( 29 ) To further remove the 60 Hz noise from the data acquisition system, a zero phase notch filer is added in the data collection program. To interface with the sensing circuit, an electrode layer covers the surface of the sensing layer 24 . Although the electrode layer may fully cover the sensing layer as shown in FIG. 3A , it is envisioned that the electrode layer may be patterned onto the surface of the sensing layer. In general, patterned electrodes are achieved during PVDF film manufacturing by screen printing conductive inks, metal masking during sputtered electrode deposition, or chemically etching patterns by photolithographic techniques. Exemplary patterns for the electrode layer are shown in FIGS. 3B-3J . The reasons for using vary shaped electrode patterns are: (1) re-configure the effective active sensing or actuating area corresponding to the stress concentrating area of the bending cantilever beam; and (2) reduce the pyroelectric effect and thermal drifts being directly proportional to the big active area, the added electrode patches can help to reject the thermal and common-mode noises using a differential measuring compensation principle; (3) enhance the generation of a tip out-of-plane force by the actuating layer as well as the detection of the tip out-of-plane velocity by the sensing layer, so that the distributed sensor/actuator pair could be used for feedback control with unconditional stability; (4) the reduced electrode layer brings down the closed circuit possibility of the electrodes of both sensing and actuating layers; (5) activate the measurement of torque and detection of torsion deformation of sensor beam due to the applied force; (6) enable the multi-point self-sensing so as to obtain feedbacks of strain, bending angle, bending moment, shear force and load of the sensor beam for stability of active servo control. (7) the shaped electrode layer can sense and control individual modes in the structure, this enables a feedback controller to be realized in terms of a suitably shaped area. It should be noted that an electrode layer of the same design is also patterned onto the actuator layer symmetrically. Finally, by considering the whole sensing system, the global transfer function is V so ⁡ ( s ) f c ⁡ ( s ) = C b ⁢ C s ⁢ ∑ i = 1 ∞ ⁢ { [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ Φ i ⁡ ( L ) ρ ⁢ ⁢ A ⁡ ( s 2 + ω i 2 ) + L 0 ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 ρ ⁢ ⁢ A ⁡ ( s 2 + ω i 2 ) } . ( 30 ) Based on this equation, we can obtain the micro force f c (t) and force rate f c (t) by measuring the output voltage V so (t) of the sensing layer when the initial values f c (t 0 ) and V so (t 0 ) are known. The actuator layer 22 serves as a distributed parameter actuator for balancing the deflections of the external micro force. The use of this actuator can virtually improve the stiffness of the high sensitive active sensor structure, so as to enhance the manipulability of flexible sensor and increase the dynamic range when it is mounted at the free end of a micromanipulator. If a voltage V a (r,t) is applied to the actuating layer 22 , it induces a longitudinal stress σ a on the layer given by: σ a ⁡ ( r , t ) = E a ⁢ d 31 H a ⁢ V a ⁡ ( r , t ) ( 31 ) where E a is the Young's modulus of the actuating PVDF film and H a is the thickness of the PVDF actuating layer 22 . The stress due to an applied voltage produces a bending moment M a along the composite sensor beam's neutral axis given by [20]: M a = ∫ H m 2 H m + H a _ ⁢ σ a ⁡ ( r , t ) ⁢ Wy ⁢ ⁢ ⅆ y = C a ⁢ V a ⁡ ( r , t ) ( 32 ) where C a = 1 2 ⁢ E a ⁢ d 31 ⁢ W ⁡ ( H a + H m ) . Obviously, C a is a constant which depends on both the geometry and the material properties of the composite sensing/actuating beam. To seek the transfer function between the actuating V a and the elastic deflection of the sensor beam at any point along the beam, similar to the sensing layer equations, let's consider the deflection of the sensor beam only caused by the actuating layer 22 , then a Bernoulli-Euler equation with an additional terms due to the actuating voltage can be described as follows. ∂ 2 ∂ r 2 ⁡ [ EI ⁢ ∂ 2 ⁢ ω a ⁡ ( r , t ) ∂ r 2 - C a ⁢ V a ⁡ ( r , t ) ] + ρ ⁢ ⁢ A ⁢ ∂ 2 ⁢ ω a ⁡ ( r , t ) ∂ t 2 = 0 ( 33 ) where E, I, L, ρ are the same definitions as equation (10) above. V a represents voltage across the actuating layer 22 . ω a (r,t) is the deflection of the sensor beam caused by the actuating voltage V a . Then the boundary conditions for the actuating equation are: ω a ⁡ ( 0 , t ) = 0 ( 34 ) EI ⁢ ∂ ω a ⁡ ( 0 , t ) ∂ r = 0 ( 35 ) El ⁢ ∂ ω a 2 ⁡ ( L , t ) ∂ r 2 = C a ⁢ V a ⁡ ( L , t ) ( 36 ) EI ⁢ ∂ ω a 3 ⁡ ( L , t ) ∂ r 3 = 0 ( 37 ) Similarly, to follow the steps of modeling of the dynamic sensing equations, and using modal analysis method, we have the similar Lagrange's equation of motion by ⅆ ⅆ t ⁢ ∂ ( E ak - E ap ) ∂ q . ai - ∂ ( E ak - E ap ) ∂ q ai = U i ( 38 ) Here, E ak is the kinetic energy, E ap represents the potential energy and U i is the generalized non-conservative forces related to the actuating moment. They are E ak = 1 2 ⁢ ∫ 0 L ⁢ ω . a ⁡ ( r , t ) 2 ⁢ ρ ⁢ ⁢ A ⁢ ⁢ ⅆ r ( 39 ) E ap = 1 2 ⁢ ∫ 0 L ⁢ EI ⁢ ⁢ ω a ″ ⁡ ( r , t ) 2 ⁢ ⁢ ⅆ r ( 40 ) U i = C a ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ V a ⁡ ( t ) ( 41 ) where Φ is the shape mode as defined in sensing section. Notice that the voltage V a is constant along the length on the beam but undergoes a step change at each of the boundaries of this length. Using the Lagrange's equation of motion (38) and orthogonality conditions (17) and (20), we have the differential equation corresponding to each shape mode to be EIα i 4 q ai ( t )+ρ A{umlaut over (q)} ai ( t )= C a [Φ′ i ( L )−Φ′ i (0)] V a ( t )   (42) Then by the Laplace transformation of the above equation, the dynamic relationship between the modal displacements q ai (s) and the input voltage V a (s) is given as q ai ⁡ ( s ) = C a ⁢ V a ⁡ ( s ) ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ρ ⁢ ⁢ A ⁢ ⁢ ( s 2 + ω i 2 ) ( 43 ) This equation describes the modal displacements of the flexible beam due to a voltage applied to the actuating layer 22 . Thus, the sensing layer 24 can detect the deformation of the sensor beam, the information then is fed back to the actuating layer 22 , the actuator will balance the deformation due to the external forces and keep the sensor beam at the equilibrium position (straight). Once balance, the external force can also be equally achieved from the balanced voltage V a of the actuating layer 22 based on the active servo transfer function between V a and the force f c . To realize this active behavior, the transfer function from the voltage applied to the actuator layer 22 to the voltage induced in the sensing layer 24 or the external force detected by the sensing layer 24 should be found first. To balance the deflection ω s (r,s) detected by the sensing layer, an opposite deflection ω a (r,s)=ω s (r,s) exerted by the actuating layer is necessary. Assumed the shape mode is the same, to balance the deflection, an opposite q si (s) should be exerted by the actuating layer. To achieve the relationship between the sensing voltage V s and the balance voltage V a , by substituting the opposite q ai (s)=−q si (s) in equation (43) into (27), then we have V s ⁡ ( s ) = - C s ⁢ ∑ i = 1 ∞ ⁢ C a ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 ⁢ V a ⁡ ( s ) ρ ⁢ ⁢ A ⁢ ⁢ ( s 2 + ω i 2 ) . ( 44 ) Continually, the transfer function between the sensing voltage V s and the balanced voltage V a can be found as V a ⁡ ( s ) V s ⁡ ( s ) = - ∑ i = 1 ∞ ⁢ ρ ⁢ ⁢ A ⁢ ⁢ ( s 2 + ω i 2 ) C s ⁢ C a ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 . ( 45 ) Sequentially, from equation (28), the active servo transfer function between the external force acting at the sensor tip and the balanced voltage V a in the actuating layer can be given by V a ⁡ ( s ) f c ⁡ ( s ) = - ∑ i = 1 ∞ ⁢ C s ⁡ ( [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] ⁢ ⁢ Φ i ⁡ ( L ) + L 0 ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 ) ρ ⁢ ⁢ A ⁢ ⁢ ( s 2 + ω i 2 ) ∑ i = 1 ∞ ⁢ C s ⁢ C a ⁡ [ Φ i ′ ⁡ ( L ) - Φ i ′ ⁡ ( 0 ) ] 2 ρ ⁢ ⁢ A ⁢ ⁢ ( s 2 + ω i 2 ) ( 46 ) The above transfer function equations can be used to generate the balance force and to calculate the micro force applied to the sensor tip during active servo balance. The active servo balance methodologies can be PI, PID, LQR (linear quadratic regulator) compensation, LQG (linear quadratic Gaussian), Luenberger observer based compensator, Kalman-Bucy filter, spatial H 2 norm, spatial H ∞ norm. For the multi-electrode-patch pattern, DSFB (direct strain feedback), SFB (shear force feedback) or BMFB (bending moment feedback) can be employed to realize active servo balance as the strain, shear force, bending moment of the sensor beam can be achieved. An exemplary micro robotic system employing an active micro-force sensor of the present invention is further described below. The micro robotic system is mainly comprised of a SIGNATONE Computer Aided Probe Station and a Mitutoyo FS60 optical microscope system. The micro robot is controlled by a PC-based control system. The system is an open platform which can easily be integrated with the active micro-force sensor of the present invention. To improve the active servo speed, real-time implementation of the proposed control algorithm was performed using an x86 based PC running Linux operating system. The RTAI (Real-time Applications Interface) patch was used to provide POSIX compliant, real-time functionality to the Linux operating system. The sensing voltage V s is the input to the PCI-DAS4020/12 acquisition board through a buffer interface circuit as shown in FIG. 2 . Based on the transfer function (45), the balance signal (in the range of ±10V) is output to the same PCI-DAS4020/12 acquisition board, furthermore, the signal is linearly amplified to approach to V a by a power amplifier built by high voltage FET-input operational amplifier OPA445 for the PVDF actuating. The maximum sampling frequency of PCI-DAS4020/12 is 20 MHz with 12-bit AD resolution. The loop time of the force sensing and control system is about 60 μs. To reduce the vibrations from the environment, an active vibration isolated table was used during the experiments. FIG. 4 depicts a block diagram of the active sensing system. As shown, it is a typical single-input-single-output feedback control loop. The feedback signal is generated by the sensing layer due to the external force at the sensor tip. The signal is conditioned by a buffer interface and filtered in the collection program. The signal is then adjusted and amplified to apply to the actuating layer 22 based on the transfer function (45). In this exemplary system, the active force sensor has the following dimensions and parameters: L=0.01864868 m; W=0.00979424 m; L 0 =0.0255778 m; C P =0.88×10 −9 F; d 31 =23×10 −12 C/N; c=102.5×10 −6 m; H a =H s =45×10 −6 m; H m =125×10 −6 M; E a =E s =2×10 9 N/m 2 ; E m =3.8×10 9 N/m 2 ; P a =P s =1.78×10 3 Kg/m 3 ; P m =1.39×10 3 Kg/m 3 . It will be appreciated that these types of the systems may be constructed with many different configurations, components, and/or values as necessary or desired for a particular application. The above configurations, components and values are presented only to describe one particular embodiment that has proven effective and should be viewed as illustrating, rather than limiting, the present invention. The transfer function between the actuating voltage V a and the sensing voltage V s is a key for active sensing. Using the V a /V s transfer function, the frequency response of the active sensor is demonstrated by simulation as shown in FIG. 5A . To test the model, we exert the known voltage signal in the range of ±30V to the actuating layer, then record the sensing voltage due to the deflection of sensor beam. FIG. 5B shows the experimental result in the relationship between the V a and V s . It can be observed that the two Bode results (comparison of three shape modes) are very close and verify the effectiveness of the developed transfer function model. For this active sensor, the frequency of the first shape mode is about 69 Hz, the second shape mode is 1.2 KHz, the third one is about 2.9 KHz. In summary, to balance the external micro force, by feedback the sensing voltage to the actuating layer through the transfer function (45) in real time, the active micro-force sensor of the present invention can be realized. In addition, the two composite active PVDF films with different pyroelectric orientations can be chosen to construct a parallel-beam structure, then two voltage variations ΔV pyro due to pyroelectric effect in two PVDF beams are opposed. As the two films are connected in parallel at the input of the buffer interface circuit or the amplifier circuit, then the pyroelectric effects of this kind of structure can be self compensated. Based on the active parallel-beam structure with the function of self thermo-compensation, a multi-axis (3-D) active micro force sensor is also designed as shown in FIG. 6 . The active beams of the sensor are aligned perpendicularly to each other, so the 3-D sensor structure also provides a decoupled force measurement in three directions. The sensing model of PVDF sensing layers in a parallel beam construction can be developed based on the formulations of the one-piece cantilever construction described above. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

An active micro-force sensor is provided for use on a micromanipulation device. The active micro-force sensor includes a cantilever structure having an actuator layer of piezoelectric material and a sensing layer of piezoelectric material bonded together. When an external force is exerted on the sensor, the sensor deforms and an applied force signal is recorded by the sensing layer. The applied force signal is then fed back to the actuating layer of the sensor via a servoed transfer function or servo controller, so that a counteracting deformation can be generated by the bending moment from the servoed actuating layer to quickly balance the deformation caused by the external micro-force. Once balanced, the sensor beam comes back to straight status and the tip will remain in its equilibrium position, thus the sensor stiffness seems to be virtually improved so that the accurate motion control of the sensor tip can be reached, especially, at the same time, the micro-force can also be obtained by solving the counteracting balance voltage applied to the actuating layer.

This application is a division of application Ser. No. 933,160, filed Nov. 21, 1986, now U.S. Pat. No. 4,802,515. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the method of containing gas or liquid cylinders in a safety environment, together with the apparatus therefor. 2. Related Art There are many types of gas cylinders which contain toxic and other hazardous gases or liquids. Through improper handling or by accident, the gas in the cylinders may begin to leak. This often occurs at the valve or valve stem. It is then incumbent upon the appropriate personnel to either stop the leak or to remove the container to a remote area for treatment of the toxic gas. An emergency team normally comprises several individuals who obviously need breathing apparatus. While the emergency team is on the premises, personnel in the laboratory, storage area, transportation area or the like either have to be evacuated or must utilize the same or similar breathing apparatus. This often creates a hazardous condition for a large number of employees, bystanders or other third parties who must be evacuated from the premises for a considerable period of time while the cylinder is either being repaired or the gases depleted such as by placing the container in a control cabinet. Often, there is no control cabinet at the particular location of the leak; therefore, it is necessary for the emergency team to move the container to another location. This obviously creates a dangerous situation, not only at the initial location, but also along the way to the containment area. Thus, a large number of individuals may be endangered, as well as entire facilities being evacuated and shut down for a considerable period of time. OBJECTS AND SUMMARY OF THE INVENTION It is therefore a prime object of the invention to provide a method and apparatus for containing a leaking cylinder by a minimum number of emergency personnel. Another object of the invention is to provide a sturdy cylinder storage container which can accommodate cylinders of varying size. Still another object of the invention is to provide a cylinder container which has means for easily removing the depleted cylinder therefrom. Another object of the invention is to provide a method and apparatus for quickly and easily moving cylinders of various sizes within the emergency container from the site of the leak by a minimum number of individuals. By use of the present invention, it is no longer necessary to move the leaking cylinder to a control cabinet since the unit can be used for pretreatment through valves thereon, or the treatment mechanism may be connected directly to the containment unit, thus making the unit a control cabinet itself. Because of the design of the containment system, it will support a rupture, as well as make it possible to open or close a valve (assuming operability of the valve) while the cylinder remains in the containment unit. The transport system associated with the containment unit cannot only be moved from place to place in a facility by rolling, but may easily be transported by vehicle from the initial location to a safer place away from employees or other individuals. A safety gas containment unit is provided with sealing means for retaining the hazardous gas therein until treated. The containment unit can be placed on a transport carrier and rotated from a vertical position to a horizontal position thereon. The gas cylinder may be brought to the containment unit by placing it on a wheeled cart. By aligning the cart with the horizontally positioned containment unit, the container is then transferred from the cart to the containment unit, which can in turn be transported to an appropriate area for treatment. Upon removal of the toxic or other gases, the container can be withdrawn from the containment unit by a winch mechanism. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the invention will be better appreciated from the following description and enclosed drawings wherein: FIG. 1 is a schematic, cross-sectional view of the containment unit taken along lines 1--1 in FIG. 2; FIG. 2 is a top view of the containment unit; FIG. 3 is a cross-sectional view taken along lines 3--3 in FIG. 1; FIG. 4 is an insert for the containment unit; FIG. 5 is a detail of the valve actuator of Detail 5 in FIG. 1; FIG. 6 is a schematic of the cylinder withdrawal mechanism; FIG. 7 is a side elevational view of the containment unit on a transport carrier; FIG. 8 is a side elevational view of the transport carrier of FIG. 7 with the containment unit rotated 90 degrees. FIG. 9 is a top plan view of the carrier of FIGS. 8 and 9; FIG. 10 is a side elevational view of a cylinder loading cart; FIG. 11 is a side elevational view of the cylinder loading cart of FIG. 10 rotated 90 degrees; and FIG. 12 is an end elevational view of the cylinder loading cart in the position shown in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION The invention includes three basic elements and associated methods, namely the containment device per se, the transport system and the cylinder withdrawal system. Containment Unit Referring first to FIGS. 1-5, a storage container is seen generally at 1. The container can be of various known materials and compositions; however, a preferred embodiment has an inner stainless steel liner which is wrapped with fiberglass or other filament wound material. The material of the liner and the wrapping, as well as the dimensions thereof, are determined by the pressure requirements and chemical resistance in a given situation. One form of liner and wrapping is illustrated in U.S. Pat. No. 3,969,812 which is hereby incorporated by reference. The cylinder 1 has a substantially hemispherical shaped top dome head 3 and is attached to an O-ring sealed access port 5, including an O-ring 7. A top access cover flange 9 includes an additional O-ring seal 11. The cover flange 9 includes a valve actuator cup 13. Attached to the cup 13 is a rod 15 which passes through the cover flange 9 and a block 17 as best seen in the detail of FIG. 5. Attached to the end of rod 15 is a modified rotary seal quick coupling 19. A bayonet lock 21 on rod 15 can accommodate a handle connected at 23 to rotate the rod 15. As seen in FIG. 2 a plurality of handles 25 are used for rotating the top cover flange 9 which seals and unseals the flange from the access port. The cover 3 as also seen in FIG. 2 includes various access ports and other openings which for example include a gas pressure gauge 27, a gas valve 29, a vacuum valve 31, a vacuum gauge 33 and an access port 35. A collar 37 which may be made of stainless steel is positioned on the cover 3 as seen in FIGS. 1 and 2. The collar 37 also supports a winch mechanism 41 (discussed below), as well as an outrigger 43 connected to a support plate by means of an outrigger support 45. Suspended from the access port O-ring flange 5 is a guide cylinder tube 47. Positioned within the unit 1 and coaxial with the tube 47 are hazardous gas containers seen as cylinders 49 and 51 of two different sizes. The two cylinders are shown merely for illustration purposes, 49 being the smaller of the two. A ring attachment 53 is seen connected to the tube 47 via a cable 55, the cylinder collar or ring 53 and cable 55, as will be seen below, provide the means for withdrawing the cylinder (such as 49 or 51) from the unit 1 by means of the winch 41. Referring to FIG. 3, together with FIG. 1, a plurality of spring loaded star rings 61 are used to center the cylinder within the unit. The star rings 61 each include an outer housing 63 and a piston member 65 to which a cylinder pad 67 is attached. The housing 63 is attached to the unit 1 by means a base pad 69. As seen in FIG. 3 a spring 71 provides the biasing means for the cylinder pads 67. Referring back to FIG. 1, a bottom 73, either hemispherically shaped or shaped as seen in FIG. 1, is attached to cylindrical unit 1 to complete the enclosure. The base 73 includes a bottom cylinder seat flange 75 positioned axially on the base 73. The seat flange includes a plurality of concentric seats 77 which support various sized cylinders such as cylinders 49 or 51 schematically seen in FIG. 1. A removable dolly generally seen at 79 is attached to the base and includes a plurality of casters 81 for the purpose seen below. During the wrapping of the unit 1, a plurality of annular locator means 83 are built in or formed thereon for positioning the unit during transportation as will also be discussed below. Referring to FIG. 4, an insert tube for small cylinders is seen generally at 85. The insert includes a cylinder 87 with a bottom cylinder seat flange 75' with seats 77' formed similar to that seen in FIG. 1. A plurality of star support rings 61' support a smaller cylinder 49' in the same manner as seen in FIG. 1. A plurality of withdrawal holes 89 are seen at the top and the bottom of the cylinder tube. The holes are for the purpose of withdrawing the insert and cylinder from the unit in the same manner as the larger cylinders are withdrawn in FIGS. 1 and 6. The insert tube 85 as seen in the position shown in FIG. 4 is designed to accommodate smaller cylinders 49', the entire unit being positioned within tube 47 in FIG. 1. However, if odd shaped containers such as spheres or other materials are to be evacuated, the insert tube 85 is inverted and the object to be removed will rest on surface 91 of a support 93 which may include an opening 95 therethrough. In other words, a lecture bottle, sphere or other odd shaped member can be supported on 91, and in order to provide the necessary support for the support ring 91, an additional brace 97 is provided. Cylinder Withdrawal System Referring primarily to FIG. 6, a cylinder such as 49 is seen positioned schematically in the unit 1. The conventional winch mechanism 41 is connected via a wire or the like 101 to the cylinder cable withdrawal chain 55 attached to collar 53. Referring also to FIG. 2, the outrigger 43 is pivoted at point 103 and includes a pulley 104. With the outrigger 43 rotated counterclockwise 90 degrees, the mechanism appears as seen schematically in FIG. 6. Thus, after the cylinder 49 is placed in the unit 1, the collar 53 is attached thereto and the outrigger 43 is rotated to the position seen in FIG. 6, the cable 101 is attached to chain 55 and the cylinder can be withdrawn at the appropriate time and place. This will be put into prospective below. As will also be appreciated below, the withdrawal can take place in a horizontal position, as well as vertical. Transport Carrier System Referring to FIGS. 7 and 8, the emergency containment unit 1 is seen positioned on a transport carrier unit 111 which includes a base 113 supported at one end by a pair of casters 115 and at the other end by an outrigger caster and brake 117. A pair of vertical support members 119 are retained in a housing 121 on the base support 113. A containment support tilt locking assembly is positioned at the upper end of members 119 and includes a pair of handle and support stand members 123 which rotate about the upper end of member 119 at a pivot (not shown). Rigidly secured to the handle and support stand 123 is a tilt locking plate 125 which is pivoted at 127 to a permanent locking plate 129. (FIG. 7). Permanent locking plate 129 is affixed to a band 131 which encircles the containment unit 1 and has a conventional pivoted band lock 133. The pivoted band lock 133 is supported between the annular ring members 83. As seen in dotted lines, an adjustable containment loading platform 135 is removably positioned on the base support 113, whereby the containment unit can be detached from the transport carrier while remaining on the adjustable loading platform. As seen in FIG. 7, the containment unit is in the vertical position and the handle and support stand members 123 extend horizontally. When it is desired to load a cylinder into the containment unit, the handles are pivoted to the position seen in FIG. 8, thus rotating the containment unit to a horizontal position while the handle members 123 act as additional support for the transport carrier. Cylinder Loading Cart Referring next to FIGS. 10-12, the container which will be considered as container 49 from FIG. 1 is loaded onto the cart generally referred to as 141. Cart 141 includes a platform 143 seen in the horizontal position in FIG. 10. A second support platform 145 is attached to platform 143 and seen in the vertical position in FIG. 10 and further includes handle means 147. Attached to support 145 are a pair of large wheels 149 and a pair of smaller wheels 151 supported on a framework 153. The framework 153 includes a pair of conventional additional supporting members 155 and 157. A vertically adjustable member 159 is attached to support 145 and has a V-block support in the form of members 161 mounted thereon. A conventional locking band 163 secures the cylinder 49 to the V-support members 161. As will be discussed below, platform 143 which is seen in the horizontal position in FIG. 10 and the vertical and upright position in FIG. 11, can pivot downward about a point 165 to a position shown in FIG. 12 to permit the cylinder 43 to slide longitudinally (FIGS. 11 and 12). Operation Briefly stated, the method of handling a defective container 49 consists of placing the cylinder on the loading cart as seen in FIG. 10. The cylinder is strapped onto the V-support block to prevent movement thereof. The cylinder loading cart 141 is then pivoted to a position midway between that seen in FIGS. 10 and 11 so that both pairs of wheels 149 and 150 engage the ground. The cylinder on the loading cart is then moved to the transport carrier which is in the position seen in FIG. 8. When the cylinder loading cart reaches the carrier, it is rotated on wheels 151 to the position seen in FIG. 11. The platform 143 is then pivoted downward to the position seen in FIG. 12. The strap 163 is removed and the cylinder is loaded into the transport carrier which is then rotated to the position seen in FIG. 7. The transport carrier is next moved to a safe area, and the containment unit 1 can be removed from the transport carrier by opening the pivoted band lock 133 and removing band 131 from the containment unit and by dropping the adjustment loading platform to free the containment unit from the platform. If it is desired to withdraw the cylinder from the containment unit, this can be done as seen in FIG. 6 by attaching the cable 101 to chain 55 and ring 53. The cylinder is then withdrawn by means winch 41. This can be done while the containment unit is either in a horizontal or vertical position. The contents from the container can be treated either in a control unit or in the containment unit itself. Such "treatment" includes "pretreatment," e.g., flooding the containment unit to maintain an inert atmosphere. While several embodiments of the invention have been described, it will be understood that it is capable of still further modifications, and this application is intended to cover any variations, uses, or adaptations of the invention, following in general the principles of the invention and including such departures from the present disclosure as to come within knowledge or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and falling within the scope of the invention or the limits of the appended claims.

A safety gas and liquid containment unit is provided with sealing for retaining the hazardous gas therein until treated. The containment unit can be placed on a transport carrier and rotated from a vertical position to a horizontal position thereon. The gas cylinder may be brought to the containment unit by placing it on a wheeled cart. By aligning the cart with the horizontally positioned containment unit, the container is then transferred from the cart to the containment unit, which can in turn be transported to an appropriate area for treatment. Upon removal of the toxic or other gases, the container can be withdrawn from the containment unit by a winch mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the United States national phase of International Application No. PCT/KR2012/011515 filed Dec. 26, 2012, and claims priority to Korean Patent Application No. 10-2011-0142160 filed Dec. 26, 2011, the disclosures of which are hereby incorporated in their entirety by reference. TECHNICAL FIELD The present invention relates to stainless steel for a fuel cell divider sheet, and a method of manufacturing the same, and more particularly, stainless steel for a fuel cell divider sheet having superior surface quality and moldability, of which yield point elongation in accordance with alloy ingredients is controlled, thereby not requiring a post processing, such as skin pass rolling and leveling, by the yield point elongation, and being appropriate to be molded into a thin plate of a fuel cell, and a method of manufacturing the same. BACKGROUND ART A polymer electrolyte fuel cell has a low working temperature of 70 to 100° C., a short operating time, and a high output density, thereby getting the spotlight as a power source for transport, a portable power source, a home power source, and the like, and a fuel cell stack includes a divider sheet including a membrane-electrode assembly including an electrolyte and electrodes (anode and cathode), and an end plate including an inlet/outlet of air and an inlet/outlet of hydrogen gas. The fuel cell divider sheet is generally formed of one of graphite, a carbon complex, a Ti alloy, stainless steel, and conductive plastic. The stainless steel is also one of main materials of the fuel cell divider sheet. The stainless steel may have low interface contact resistance, superior corrosion resistance and thermal conductivity, and low gas transmissibility, be formed to have a large area, have superior product moldability, and be formed to be thin, thereby decreasing volume and weight of the fuel cell stack. The metal divider sheet using stainless steel is subjected to a process of forming a channel provided with a flow path by using a material generally having a small thickness of around 0.1 mm by using stamping and hydroforming processes, unlike to a process of designing and manufacturing a flow path of a graphite divider sheet by using a mechanical machining method. In the thin plate stainless steel, which is subjected to the aforementioned molding process, moldability of a material needs to be superior, there have to be no surface defect in a product after molding, and a molding deformed portion needs not to have necking and fracture even under a design requirement of various molding flow path depths and channel widths. In terms of the moldability of the stainless steel thin plate product, there is a fracture phenomenon by local concentration of stress of the material by stretcher strain and the like by yield point elongation of the material depending on a section of plastic deformation applied to the material, and a moldability problem due to a surface defect or elongation deterioration by a non-uniform deformation pattern of a surface. The stretcher strain defect generated by yield point elongation of metal among the factors is a phenomenon in which non-uniform deformation of the material is incurred by the small amount of interstitial solid solution elements of the material, an intaglio pattern shaped like a flame is represented on a surface, and thus the entire surface becomes rough while the deformation continues, and this phenomenon may cause a defect by fine wrinkles formed at the channel portion, in which the flow path of the divider sheet is molded, or generation of fracture by local concentration of stress to a deformed portion of the material deformed area during the molding of the fuel cell divider sheet, so that a fundamental solution is demanded. Accordingly, removal of yield point elongation may be considered as an essential element for improving moldability during the molding of the fuel cell divider sheet. In general, in order to remove yield point elongation, a method of removing yield point elongation by cold rolling or leveling a final rolled sheet material by 0.5 to 2%. However, there is a problem in that manufacturing cost of a material may be increased due to an additional process, such as cold rolling or leveling, and yield point elongation may be re-generated after a predetermined time. An object of the present invention is to provide stainless steel for a fuel cell divider sheet having superior moldability, which has no stretcher strain by yield point elongation of a material, has superior elongation, and has no fracture by local concentration of stress to a deformed region of the material during molding of a flow path of the divider sheet for a thin plate material. Another object of the present invention is to provide a method of manufacturing stainless steel, which has superior surface quality, in addition to moldability, to be used for a divider sheet of a fuel cell for a vehicle, home, and a portable use. SUMMARY OF THE INVENTION An exemplary embodiment of the present invention provides a stainless steel having superior surface quality and moldability, including: in weight %, more than 0 to no more than 0.02% of C; more than 0 to no more than 0.02% of N; more than 0 to no more than 0.4% of Si; more than 0 to no more than 0.2% of Mn; more than 0 to no more than 0.04% of P; more than 0 to no more than 0.02% of S; 25.0 to 32.0% of Cr, 0 to 1.0% of Cu; more than 0 to no more than 0.8% of Ni; 0.01 to 0.5% of Ti; 0.01 to 0.05% of Nb, 0.01 to 1.5% of V; residual Fe; and inevitably contained elements, wherein the stainless steel meets Formula (1) below, and has yield point elongation of no more than 1.1%. 9.1C−1.76V+5.37(C+N)/Ti−1.22Nb≦0.7  Formula (1) Further, the stainless steel may include more than 0 to no more than 0.3% of Ni in weight %. In the present invention, the stainless steel may further include one or two elements selected from the group consisting of 0 to 4% of Mo and 0 to 1% of W in weight %. Further, the stainless steel may include (Ti,Nb) (C,N) precipitates, in which an area fraction (%) of the entire precipitates per unit area in the stainless steel may be no more than 3.5%, and an area fraction (%) of (Ti,Nb) (C,N) precipitates/entire precipitates may be 62% or more. Further, in the stainless steel, C+N may be no more than 0.032% in weight %. Another exemplary embodiment of the present invention provides a method of manufacturing a stainless steel having superior surface quality and moldability, including: in weight %, more than 0 to no more than 0.02% of C; more than 0 to no more than 0.02% of N; more than 0 to no more than 0.4% of Si; more than 0 to no more than 0.2% of Mn; more than 0 to no more than 0.04% of P; more than 0 to no more than 0.02% of S; 25.0 to 32.0% of Cr; 0 to 1.0% of Cu; more than 0 to no more than 0.8% of Ni; 0.01 to 0.5% of Ti; 0.01 to 0.5% of Nb; 0.01 to 1.5% of V; residual Fe, and inevitably contained elements, in which the stainless steel having a composition meeting Formula (1) is subjected to a casting process, a hot rolling process, and a cold rolling process, and then cold-rolling annealing heat treatment, and yield point elongation is controlled to be no more than 1.1%, and a temperature of the cold annealing after the cold rolling process is controlled under a temperature condition of 900 to 1100° C. 9.1C−1.76V+5.37(C+N)/Ti−1.22Nb≦0.7  Formula (1) Further, the stainless steel may include more than 0 to no more than 0.3% of Ni in weight %, and no more than 0.032% of C+N. Further, the stainless steel may include (Ti,Nb) (C,N) precipitates, in which an area fraction (%) of the entire precipitates per unit area in the stainless steel is no more than may be no more than 3.5%, and an area fraction (%) of (Ti,Nb) (C,N) precipitates/entire precipitates may be 62% or more. In the present invention, the stainless steel is repeatedly subjected to a casting process, hot rolling, hot annealing, cold rolling, and cold annealing, and a temperature of the cold annealing is a temperature condition of 900 to 1100° C. As described above, it is possible to obtain the stainless steel for a fuel cell divider sheet having an optimum alloy design in which yield point elongation is decreased to 1.1% or lower by adjusting the quantity of interstitial alloy elements (C and N) of steel, and the content of appropriate stabilization elements (Ti, Nb, and V). Further, the present invention may manufacture the stainless steel for a fuel cell divider sheet which does not require a post processing, such as skin pass rolling and leveling, within the component range, and is appropriate to mold a fuel cell thin plate. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph illustrating a relationship between a content of a component element and measured yield point elongation according to the present invention. FIG. 2 is a picture diagram illustrating surfaces shapes of a fuel cell divider sheet molded product molded by Steel of the Comparative Example and steel of the present invention. FIG. 3 is a graph illustrating a computer simulation result of a true stain rate distribution in a longitudinal direction of a specimen and a maximum value thereof at the same stroke of a punch, during a V-bending test in the case where there is no yield point elongation (an upper diagram) and there is yield point elongation of 4% (a lower diagram). FIGS. 4A and 4B are pictures of a transmission electron microscopy of Steel 4 of the Comparative Example ( FIG. 4A ) and Steel 5 of the present invention ( FIG. 4B ) of Tables 1 and 2. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood that the terminology used therein is for the purpose of describing particular embodiments only and is not intended to be limiting. It should be noted that, as used in the specification and the appended claims, the singular forms include plural references unless the context clearly dictates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated properties, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other properties, regions, integers, steps, operations, elements, and/or components thereof. All of the terminologies containing one or more technical or scientific terminologies have the same meanings that persons skilled in the art understand ordinarily unless they are not defined otherwise. The terminologies that are defined previously are further understood to have the meaning that coincides with the contents that are disclosed in relating technical documents, but not as the ideal or very official meaning unless it is not defined. Ferrite-based stainless steel for a fuel cell divider sheet having superior moldability and surface quality according to the present invention further includes a composition including one or two elements selected from the group consisting of, in weight%, more than 0 and no more than 0.2% of C, more than 0 and no more than 0.2% of N, more than 0 and no more than 0.4% of Si, more than 0 and no more than 0.2% of Mn, more than 0 and no more than 0.4% of P, more than 0 and no more than 0.2% of S, 25.0 to 32.0% of Cr, 0 to 1.0% of Cu, more than 0 and no more than 0.8% of Ni, 0.01 to 0.5% of Ti, 0.01 to 0.5% of Nb, 0.01 to 1.5% of V, 0 to 4% of Mo, and 0 to 1% of W, and residual Fe, and inevitably contained elements. In the present invention, a final cold rolled product is manufactured by forming a hot rolled coil by performing hot rolling, annealing, and picking on a slab having the composition, and repeatedly performing cold rolling, annealing, and picking or cold rolling and bright annealing on the hot rolled coil. Hereinafter, a composition range of the present invention and a reason of limitation of the composition range will be described in more detail. Further, % described in below means weight %. C is an element of forming carbide and exists in an interstitial type, so that when C is excessively contained, strength may be increased, but an elongation rate may deteriorate. Further, the excessive containment of C increases yield point elongation, thereby causing deterioration of moldability. Accordingly, it is preferable that the content of C is limited to no more than 0.02%. N is an element of forming a nitride and exists in an interstitial type, so that when N is excessively contained, strength may be increased, but an elongation rate and yield point elongation are disadvantageous. Accordingly, it is preferable that the content of N is limited to no more than 0.02%. Si is an effective element for deoxidation, but suppresses toughness and moldability, so that a composition ratio of Si is limited to no more than 0.4% in the present invention. Mn is an element increasing deoxidation, but MnS, which is an inclusion, decreases corrosion resistance, so that a composition ratio of Mn is limited to no more than 0.2% in the present invention. P decreases toughness, as well as corrosion resistance, so that a composition ratio of P is limited to no more than 0.04% in the present invention. S degrades an anti-pitting property and hot processibility, so that a composition ratio of S is limited to no more than 0.02% considering the degradation of an anti-pitting property and hot processibility in the present invention. Cr increases corrosion resistance in an acidic atmosphere, in which a fuel cell is operated, but decreases an elongation rate to degrade moldability, so that a composition ratio of Cr is limited to 25% to 32% in the present invention. Cu increases corrosion resistance in an acidic atmosphere, in which a fuel cell is operated, but decreases an elongation rate to degrade moldability when exceeding 1%, so that a composition ratio of Cr is limited to no more than 1%. When Ni is added to exceed a composition ratio of 0.8%, Ni is eluted and an elongation rate is decreased during an operation of the fuel cell, so that moldability of a material may be degraded. Accordingly, it is preferable that a composition ratio of Ni is preferably limited to no more than 0.8%. Further, when Ni is added with a composition ratio of no more than 0.3%, Ni more effectively influences softness of a material, thereby improving moldability. Accordingly, it is more preferable that a composition ratio of Ni is limited to more than 0 to no more than 0.3%. Ti and Nb are effective elements for forming C and N in the steel into a carbide, and particularly, are effective elements for increasing an elongation rate of a material, and suppressing yield point elongation. Accordingly, when Ti and Nb are excessively added, appearance deteriorates and toughness is decreased by an inclusion. Considering this, a composition of each of Ti and Nb is limited to 0.01 to 0.5% in the present invention. V is an element for forming carbide, and is an effective element for suppressing yield point elongation to improve moldability. When V is excessively added, corrosion resistance and toughness are degraded, and cost of V is high, so that a composition ratio of V is limited to 0.01 to 1.5%. Mo serves to increase corrosion resistance in an environment atmosphere in which the fuel cell is operated, but when Mo is excessively added, Mo decreases an elongation rate and economical feasibility of a material, so that a composition ratio of Mo is limited to a range of 0% to 5% in the present invention. W has an effect in increasing corrosion resistance in an acidic atmosphere, in which the fuel cell is operated, and decreasing interface contact resistance, but when W is excessively added, W decreases an elongation rate of a material to degrade moldability. Accordingly, considering this, a composition ratio of W is limited to 0 to 1.0% in the present invention. In the present invention, one or more kinds of Mo and W may be added. In the meantime, in composing steel in the present invention, when contents of C, N, V, Ti, and Nb in the composition ranges of Formula (1) below are adjusted to be no more than 0.7, it is possible to manufacture a steel material having yield point elongation of a material of no more than 1.1% and superior moldability. Herein, Formula (1) is a result obtained by inserting a value of weight % for each component, for example, C, N, V, Ti, and Nb. 9.1C−1.76V+5.37(C+N)/Ti−1.22Nb≦0.7  Formula (1) Hereinafter, a process of manufacturing stainless steel including the aforementioned composition will be described. In the present invention, first, the steel, which is alloy-designed as described above, is manufactured into a slab through a casting process. Next, the slab is repeatedly subjected to hot rolling, hot annealing, cold rolling, and then an annealing heat treatment, and then a final cold-rolled plate having a desired thickness is manufactured. In the present manufacturing process, a temperature of the cold annealing may be a temperature condition of 900 to 1100° C. When the temperature of the cold annealing is 1100° C. or higher, grain is coarsened, so that a yield point elongation phenomenon may be removed, but an elongation rate is decreased, so that moldability is poor and there is a concern in strip breakage by coil tension during the annealing. When the temperature of the cold annealing is 900° C. or lower, a recrystallization texture is not developed, so that moldability is poor. Exemplary Embodiment Hereinafter, the present invention will be described with reference to the exemplary embodiment in more detail. Table 1 represents a relationship of yield point elongation between the present invention and the Comparative Example. Formula (1) represented in Table 1 is described below. 9.1C−1.76V+5.37(C+N)/Ti−1.22Nb  Formula (1) Further, yield point elongation was measured for a cold rolled sheet of 0.2 mm. TABLE 1 Yield point elongation Formula C Si Al P S Cr Cu Ti Mb V N Others (%) (1) Steel 1 of 0.0077 0.113 0.05 <0.003 <0.002 30.13 0.49 0.05 0.24 0.41 0.0130 1.8 1.28 Comparative Example Steel 2 of 0.0082 0.119 0.05 <0.003 <0.002 30.06 — 0.05 0.25 0.41 0.0160 2.0 1.65 Comparative Example Steel 3 of 0.0072 0.113 0.04 <0.003 <0.002 28.02 — 0.05 0.25 0.41 0.0150 1.5 1.42 Comparative Example Steel 4 of 0.0082 0.110 0.05 <0.003 <0.002 28.05 0.49 0.05 0.24 0.41 0.0160 2.1 1.66 Comparative Example Steel 5 of 0.0036 0.126 0.03 <0.003 <0.002 29.90 0.51 0.04 0.35 0 0.0080 1.2 1.16 Comparative Example Steel 6 of 0.0035 0.126 0.01 <0.003 <0.002 30.27 0.49 0.04 0.37 0 0.0084 1.8 1.18 Comparative Example Steel 7 of 0.0083 0.130 0.02 <0.003 <0.002 29.60 0.51 0.05 0.50 0.40 0.0170 2.0 1.48 Comparative Example Steel 8 of 0.0065 0.113 0.02 <0.003 <0.002 29.89 0.51 0.05 0.25 0.40 0.0190 2.3 1.79 Comparative Example Steel 1 of the 0.0047 0.112 0.05 <0.003 <0.002 28.01 — 0.05 0.15 0.3 0.0080 1.1 0.7 presnet invention Steel 2 of the 0.0070 0.084 0.05 <0.003 <0.002 30.27 — 0.11 0.08 0.50 0.0190 0.7 0.36 presnet invention Steel 3 of the 0.0060 0.111 0.05 <0.003 <0.002 30.43 — 0.10 0.24 0.50 0.0150 0.2 0.01 presnet invention Steel 4 of the 0.0060 0.135 0.05 <0.003 <0.002 30.43 — 0.18 0.08 0.49 0.0170 0.1 −0.22 presnet invention Steel 5 of the 0.0060 0.126 0.05 <0.003 <0.002 30.49 — 0.20 0.24 0.50 0.0170 0.01 −0.50 presnet invention Steel 6 of the 0.0060 0.116 0.05 <0.003 <0.002 30.20 0.51 0.20 0.24 0.50 0.0170 0.0 −0.50 presnet invention Steel 7 of the 0.0060 0.093 0.05 <0.003 <0.002 30.44 — 0.16 0.20 0.47 0.0150 1Mo 0.0 −0.31 presnet invention An ingot is manufactured by dissolving the alloy having the composition represented in Table 1 in a vacuum induction furnace of a capacity of 50 kg. A hot rolled steel plate is manufactured by hot rolling and then hot annealing the manufactured ingot. Then, a cold rolled plate is manufactured by cold rolling the hot rolled plate so as to have a final thickness of 0.2 mm. The manufactured cold rolled plate was annealed at a heating temperature of 1000° C., and then was subjected to rapid cooling. The manufactured cold rolled plate is processed to a specimen in a direction parallel to a rolling direction under the specimen standard JIS13B after picking, and a tension test thereof is performed at a crosshead speed of 20 mm/min. A yield point elongation rate according to each material element is measured through the tension test. FIG. 1 illustrates a result of comparison between yield point elongation (%) and Formula (1) of the cold rolled and annealed plate having a thickness of 0.2 mm according to Table 1, and FIG. 2 illustrates a result of a surface shape of a material, which is obtained by performing cold rolling (0.2 mm t) and annealing heat treatment on Steel 5 of the Comparative Example (left side) and Steel 1 of the present invention (right side) at a temperature of 1000° C., stamping molded into a fuel cell divider sheet with an electrode effective area of 200cm 2 . Steel 5 of the Comparative Example exhibits a stretcher strain defect in a shape of an intaglio pattern on the surface after the processing, but Steel 1 of the present invention may obtain a good surface quality having no stretcher strain defect. Further, in an aspect of a thickness decrease rate of a deformed portion, it is possible to obtain better moldability from Steel 1 of the present invention, than Steel 5 of the Comparative Example. As represented in Table 1 and FIG. 2 , it can be seen that moldability is improved in Steel 1 of the present invention (yield point elongation is 1.1%, and a result value of Formula (1) is 0.7), compared to Steel 5 of the Comparative Example (yield point elongation is 1.2%, and a result value of Formula (1) is 1.16). The yield point elongation is an item based on which moldability may be confirmed, and when the yield point elongation exceeds 1.1%, there occurs problem in that local concentration of stress to a processing deformed portion (an arrow of FIG. 2 ) is intensified during the processing of the steel in order to use the steel for the fuel cell divider sheet, so that a stripe shape is formed. That is, when the yield point elongation exceeds 1.1%, and a value according to Formula (1) exceeds 0.7, moldability deteriorates. As represented in Table 1, it is preferable that the yield point elongation is no more than 1.1%, and it can be seen that the yield point elongation is decreased when the calculated value of Formula (1) is adjusted to be no more than 0.7 by appropriately adjusting contents of interstitial alloy elements (C and N) and V, Ti, and Nb, which are the carbide forming elements. When the calculated value of Formula (1) exceeds 0.7, yield point elongation exceeds 1.1%. FIG. 1 illustrates a result of comparison of yield point elongation (%) of the cold rolled and annealed plate having a thickness of 0.2 mm according to the component content of the present invention based on the value of Formula (1). Accordingly, referring to FIG. 1 and Table 1, it can be seen that when a value of Formula (1) is no more than 0.7, yield point elongation is no more than 1.1%, and the stainless steel has moldability appropriate to the fuel cell divider sheet at yield point elongation of no more than 1.1%. Further, the stainless steel according to the present exemplary embodiment may include (Ti, Nb) (C, N) precipitates, Nb 2 C precipitates, and laves phase (Fe 2 Nb) precipitates. A surface of the stainless steel may be covered by the (Ti, Nb)(C, N) precipitates, the Nb 2 C precipitates, and the laves phase (Fe 2 Nb) precipitates (the entire precipitates), and in this case, an area fraction of the entire precipitates per unit area of the stainless steel may be no more than 3.5%, and an area fraction of (Ti, Nb)(C, N) precipitates/entire precipitates (%), which is the ratio of the (Ti, Nb)(C, N) precipitates with respect to the entire precipitates, may be 62% or more. Here, (Ti, Nb)(C, N) precipitates exist as one precipitate phase, and the (Ti, Nb)(C, N) precipitates effectively fix N and C within a base, thereby improving yield point elongation of the stainless steel to improve moldability. It can be seen that a partial fraction of the (Ti, Nb)(C, N) precipitates, in which V and Cr are partially solid-dissolved, tend to be increased and an area fraction of the entire precipitates per unit area is decreased than the Nb2C precipitates and the laves phase (Fe 2 Nb) when the alloy component per unit area (100 nm 2 ) for the entire precipitates included on the surface of the stainless steel is adjusted to have no more than 0.7 calculated by Formula (1), compared to the case where the alloy component per unit area (100 nm 2 ) for the entire precipitates included on the surface of the stainless steel exceeds 0.7. Here, the area fraction of the entire precipitates means a degree by which the entire precipitates covers the steel with respect to the entire area of the steel (after the annealing of the cold rolled steel with 0.2 mm) used as the specimen. Table 2 is a result of an analysis of the entire precipitates and an area fraction of the entire precipitates per unit area (100 nm 2 ) measured by a Transmission Electron Microscope (TEM) by using an image analysis instrument for the steel of Table 1. In this case, in Table 2, each kind of steel was randomly measured by using the transmission electron microscope while changing a position thereof, and each of values described in Table 2 is an average value of values of five times of measurement performed on one specimen (one kind of steel). TABLE 2 Area fraction of entire Area fraction precipitates per (Ti,Nb)(C,N)/entire Entire precipitates unit area (%) precipitates (%) Steel 1 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 4.0 52 Comparative Example Steel 2 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 4.2 41 Comparative Example Steel 3 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 4.2 55 Comparative Example Steel 4 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 5.6 52 Comparative Example Steel 5 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 3.7 57 Comparative Example Steel 6 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 5.1 50 Comparative Example Steel 7 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 4.2 49 Comparative Example Steel 8 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 4.1 44 Comparative Example Steel 1 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 1.8 65 presnet invention Steel 2 of the (Ti,Nb)(C,N),Nb 2 C 2.4 70 presnet invention Steel 3 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 2.8 80 presnet invention Steel 4 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 3.4 82 presnet invention Steel 5 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 3.2 82 presnet invention Steel 6 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 3 83 presnet invention Steel 7 of the (Ti,Nb)(C,N),Nb 2 C,(Fe,Cr) 2 Nb 2.9 82 presnet invention Referring to Table 2, it can bee seen that an area fraction of the entire precipitates per unit area of each of Steel 1 to 8 of the Comparative Example has a minimum of 3.7% to a maximum of 5.6%, but an area fraction of the entire precipitates per unit area of each of Steel 1 to 7 of the present invention has a maximum of 3.4%, which is no more than 3.5%. Further, it can bee seen that an area fraction of (Ti,Nb)(C,N) precipitates for the entire precipitates of each of Steel 1 to 8 of the Comparative Example has a maximum of 57%, but an area fraction of (Ti,Nb)(C,N) precipitates for the entire precipitates of each of Steel 1 to 7 of the present invention has a maximum of 83% and a minimum of 65%, thereby having a larger value than those of Steel 1 to 8 of Comparative Example. Accordingly, it can be seen that when the area fraction of the entire precipitates per unit area is no more than 3.5% as in Steel 1 to 7 of the present invention, and the area fraction of (Ti,Nb)(C,N) precipitates/entire precipitates (%) is 62% or more, a value of Formula (1) is no more than 0.7, and yield point elongation also exceeds 1.1%. When the precipitates are increased in the stainless steel, the precipitates may harden a substrate of the steel. Accordingly, the increase of the precipitates may increase yield point elongation, and in this case, when the area fraction per unit area of the total quantity of the precipitates (entire precipitates) exceeds 3.5%, moldability of the steel may deteriorate. In this case, an area fraction of (Ti, Nb)(C, N) precipitates/entire precipitates (%), which is the ratio of the (Ti, Nb)(C, N) precipitates with respect to the entire precipitates, is preferably 62% or more, and when an area fraction of (Ti, Nb)(C, N) precipitates/entire precipitates (%) is less than 62%, C and N cannot be solid-dissolved, thereby increasing yield point elongation and degrading moldability. Accordingly, the area fraction of the entire precipitates per unit area of the stainless steel is no more than 3.5%, and an area fraction of (Ti, Nb)(C, N) precipitates/entire precipitates (%) is 62% or more, and contents of C and N solid-dissolved in the substrate of the stainless steel may be considerably reduced, the contents of V, Ti, and Nb, and the contents of the interstitial elements (C and N) in the steel may have an appropriate level, so that there is no yield point elongation, and the participates are not excessively generated, thereby improving moldability. Accordingly, it is possible to prevent local fracture or necking of the deformed portion when molding a surface shape of stainless steel and the fuel cell divider sheet, thereby providing a steel material having superior moldability. Table 3 represents a result of a relationship of yield point elongation for C+N according to the present invention and the Comparative Example. In Steel of the Comparative Example, and Steel of the present invention of Table 3, the relationship is confirmed by the same method using the cold rolled sheet of 0.2 mm that is the same as that of Table 1. TABLE 3 Yield point elongation Formula C Si Cr Ti Nb V N C + N (%) (1) Steel 9 of the 0.0177 0.113 30.13 0.08 0.24 0.41 0.02 0.0377 2.5 1.677 Comparative Example Ssteel 10 of 0.022 0.119 30.06 0.05 0.25 0.44 0.016 0.038 2 3.202 the Comparative Example Steel 11 of the 0.019 0.113 28.02 0.05 0.25 0.51 0.015 0.034 1.5 2.622 Comparative Example Steel 8 of the 0.005 0.112 28.01 0.08 0.024 0.41 0.007 0.012 0.5 0.100 present invention Steel 9 of the 0.007 0.09 30.27 0.11 0.056 0.52 0.011 0.018 0.4 −0.041 present invention Steel 10 of the 0.018 0.111 30.43 0.1 0.25 0.5 0.014 0.032 0 0.697 present invention In the stainless steel according to the present exemplary embodiment, C+N may be no more than 0.032% in weight %. When the large amount of C and N is contained, the contents of solid-dissolved C and N are increased, and the large amount of precipitates is formed, thereby increasing yield point elongation and degrading moldability. In this case, in order to reduce the contents of solid-dissolved C and N, which increase yield point elongation when the value of C+N exceeds 0.032%, the excessive contents of Ti, Nb, and V need to be added, so that manufacturing cost of the stainless steel may be unnecessarily increased, or a material softening effect is hindered by the excessive forming of carbonitride, thereby degrading general moldability. That is, the value of C+N is controlled to have no more than 0.032%, so that it is possible to decrease the contents of entire solid-dissolved C and N in the steel, thereby minimizing yield point elongation, and to minimize carbonitride formed of C and N with Ti, Nb, and V, thereby improving general moldability. Table 3 is a confirmed result of yield point elongation for Steel 9 to 11 of the Comparative Example, and Steel 8 to 10 of the present invention. As represented in Steel 9 to 11 of the Comparative Example, it can be seen that when the values of C+N are 0.0377, 0.038, and 0.034, the values of yield point elongation are 2.5, 2, and 1.5, respectively, and moldability is disadvantageous. Further, it can be seen that the values according to Formula (1) for Steel 9 to 11 of the Comparative Example are 1.677, 3.202, and 2.622, which exceed 0.7. In the meantime, in the case of steel 8 to 10 of the present invention, it can be seen that when the values of C+N are 0.012, 0.018, and 0.032, yield point elongation is 0.5, 0.4, and 1.1, respectively, all of which are no more than 1.1%. Further, it can be seen that the values according to Formula (1) for steel 8 to 10 of the present invention are 0.1, −0.041, and 0.697, all of which are no more than 0.7, and steel 8 to 10 of the present invention have superior surface quality and moldability, thereby being appropriately used for the fuel cell divider sheet. That is, as represented in Table 3, it can be seen that the total amount of C+N may be managed based on the precipitates elements, and the value of C+N is preferably managed to be no more than 0.032%, considering moldability, yield point elongation, and manufacturing cost of the stainless steel. FIGS. 4A and 4B are pictures of a transmission electron microscopy of Steel 4 ( FIG. 4A ) of the Comparative Example and Steel 5 ( FIG. 4B ) of the present invention of Tables 1 and 2. Referring to FIG. 4 , it can be seen that in the case of FIG. 4A that is Steel 4 of the Comparative Example, a ratio of the entire precipitates per unit area (100 nm 2 ) of the stainless steel is 5.6% in an area fraction, and in the case of FIG. 4B that is steel 5 of the present invention, a ratio of the entire precipitates per unit area (100 nm 2 ) of the stainless steel is 3.2% in an area fraction. The result is the ferrite-based stainless steel including, in weight %, no more than 0.02% of C, no more than 0.02% of N, no more than 0.4% of Si, no more than 0.2% of Mn, no more than 0.4% of P, no more than 0.02% of S, 25.0 to 32.0% of Cr, 0 to 1.0% of Cu, no more than 0.8% of Ni, 0.01 to 0.5% of Ti, 0.01 to 0.5% of Nb, 0.01 to 1.5% of V, residual Fe, and inevitable contained elements, and by using an alloy component, in which, in weight%, the contents of Ti, Nb, V, C, and N in steel are adjusted to be the component range of 0.7% according to Formula (1), it is possible to manufacture a steel material which has yield point elongation of the material for molding the fuel cell divider sheet of no more than 1.1%, has superior surface quality of a molded product, and achieves superior moldability having no necking of the deformed portion. In the meantime, FIG. 3 is a graph illustrating a computer simulation result of a true stain rate distribution in a longitudinal direction of a specimen and a maximum value thereof at the same stroke of a punch, during a V-bending test in the case where there is no yield point elongation (an upper diagram) and there is yield point elongation of 4% (a lower diagram). The case where there is yield point elongation shows a maximum strain rate of a bending deformation concentrated portion in a longitudinal direction of 0.061, and shows a result that a strain rate of 0.02 is increased (about 2% in an engineering strain rate) compared to the case of the test of the material having no yield point elongation which has a maximum strain rate of 0.041. Further, in the case where there is yield point elongation, a deformed shape of the specimen shows a slightly bent shape, not a relatively smooth curve line, and this is a phenomenon generated due to concentration of deformation because an yield point elongation phenomenon fails to induce the distribution of deformation increased from the surface of the material in the longitudinal direction of the specimen during the bending deformation of the material, and means deterioration of bending resistance. This may cause excessive deformation concentration and degrade of a thickness decrease rate in a stamping process of the fuel cell divider sheet mainly including a bending molding mode. Accordingly, removal of yield point elongation may be considered as an essential element for improving moldability during the molding of the fuel cell divider sheet. In general, in order to remove yield point elongation, a method of removing yield point elongation by cold rolling or leveling a final rolled sheet material by 0.5 to 2%. However, there is a problem in that manufacturing cost of a material may be increased due to an additional process, such as cold rolling or leveling, and yield point elongation may be re-generated after a predetermined time. Further, the present invention may further include an operation of molding the stainless steel alloy designed with the aforementioned composition into a thin plate for the fuel cell divider sheet, thereby finally obtaining stainless steel for the high polymer fuel cell divider sheet. The technical spirit of the present disclosure have been described according to the exemplary embodiment in detail, but the exemplary embodiment has described herein for purposes of illustration and does not limit the present disclosure. Further, those skilled in the art will understand various modification examples may be available within the scope of the technical spirit of the present invention.

Provided is a ferrite-based stainless steel having superior moldability when molding a fuel cell divider sheet from a material by controlling yield point elongation in accordance with alloy components. The ferrite-based stainless steel comprises, in weight percentages: no more than 0.02% of C; no more than 0.02% of N; no more than 0.4% of Si; no more than 0.2% of Mn; no more than 0.04% of P; no more than 0.02% of S; 25.0-32.0% of Cr; 0-1.0% of Cu; no more than 0.8% of Ni; no more than 0.01-0.5% of Ti; no more than 0.01-0.5% of Nb; no more than 0.01-1.5% of V; and residual Fe and inevitable elements, wherein the content of Ti, Nb, V, C, and N in terms of weight % of steel uses Formula (1) to render a yield point elongation of the material of no more than 1.1%, and wherein a steel material has superior moldability. 9.1C−1.76V+5.37(C+N)/Ti−1.22Nb≦0.7.  Formula (1)

This application is a divisional I of Ser. No. 07/498,858 filed Mar. 26, 1990 which is a divisional of Ser. No. 226,080 filed Jul. 29, 1988, now U.S. Pat. No. 4,918,229. See also U.S. Pat. Nos. 5,087,700 issued Feb. 11, 1992, 5,210,310 issued May 11, 1993 and 5,214,206 issued May 25, 1993 from divisionals of parent Ser. No. 226,080. BACKGROUND OF THE INVENTION A. Technical Field This invention relates to the synthesis of primary amines including optically active primary amines, and more particularly to improved processes for producing such primary amines from olefins and boronic esters, and to novel intermediates useful therein. Optically active primary amines are of major biological and synthetic importance. For example, (R)-(-)-sec-butylamine is present in pharmacologically active species such as β-blockers and CNS analgesics. In the typical synthesis of primary amines, RNH 2 from organoboranes, one organic group is typically lost as boronic acid which results in a maximum yield of 67% for less hindered R groups and 50% for more hindered R groups. Accordingly, there has been a long-standing need for methods which provide a more efficient transfer of organyl groups from boron to nitrogen. The present invention provides such intermediates and methodologies. B. Prior Art Organoboranes have been used to synthesize amines by reaction with appropriate aminating reagents such as NH 2 Cl and NH 2 OSO 3 H (H. C. Brown, W. R. Heydkamp, E. Breuer, W. S. Murphy, J. Am. Chem, Soc, 1964, 86, 3365]; NH 3 +NaOCl [G. W. Kabalka, K. A. Sastry, G. W. McCollum, H. Yoshioka, J. Org, Chem. 1981, 46, 4296); chloramine-T [V. B. Jigajinni, A. Pelter, K. Smith, Tetrahedron Letters 1978, 181] and Q-mesitylenesulfonylhydroxylamine (Y. Tamura, J. Minamikawa, S. Fujii, M. Ikeda, Synthesis 1973, 196]. As mentioned above, yields achieved in these prior art processes were, at most, 67% for less hindered R groups and 50% for more hindered R groups. The reaction of trialkylboranes with freshly prepared chloramine proceeds in the presence of aqueous sodium hydroxide. However, only two of the three groups in R 3 B were utilized. ##STR1## Consequently the maximum possible yield for R 3 B is only 67%. H. C. Brown, W. R. Heydkamp, E. Breur and W. S. Murphy, J. Am. Chem, Soc., 86, 3365 (1964). More hindered alkenes undergo hydroboration only to the dialkylborane stage, readily converted into the corresponding dialkylborinic acids or esters. These derivatives also react with preformed chloramine to form the primary amines. But in this case, only one of the two groups could be made to react. ##STR2## Consequently, in such cases, the maximum yield is only 50%. Moreover, the reaction of the more hindered dialkylborane derivatives is very sluggish with decreased yields. H. C. Brown, G. W. Kramer, A. B. Levy and M. M. Midland, "Organic Synthesis via Boranes", Wiley-Interscience, New York, 1975. The preparation of optically active primary amines of very high enantiomeric purities from boronic esters of essentially 100% optical purity and LiMe was described by Herbert C. Brown et al, J. Am. Chem, Soc, 1986, 108, 6761-6764. This procedure produced optically pure primary amines in yields of between 72-83%. While improved yields were obtained on a laboratory scale, methyllithium is a relatively expensive reagent, and is too expensive to be used for large scale commercial production of amines. Thus a need remains for a process for economically producing primary amines in high yields as well as for economically producing optically active amines of high optical purity in improved yields. The present invention provides a process which enables synthesis of both hindered and unhindered primary amines in excellent yields of up to 95%, and in all cases, in higher yields than those achieved by prior art methods. SUMMARY OF THE DISCLOSURE In one embodiment, the present invention provides a simple procedure for converting olefins such as alkenes into the corresponding primary amine by reacting the appropriate dimethylborane, prepared f rom the desired olefin and dimethylborohydride, with a suitable aminating agent according to the following reaction scheme: ##STR3## In another embodiment, optically active primary amines are prepared from optically pure R*BIpc 2 according to the following reaction scheme: ##STR4## Alternatively, trimethylaluminum, AlMe 3 , can be substituted for the methyl Grignard reagent in non-ethereal solvents. A representative reaction with a trimethylene glycol ester is shown below. ##STR5## The present invention also provides novel intermediates represented by the formula RBMe 2 and R*BMe 2 wherein R is an organo group and R* is a chiral organo group. As used herein, the term "organo" refers to organyl groups having up to 30 carbon atoms. The process is broadly applicable to any organyl group, substituted or unsubstituted, i.e., alkyl, cycloalkyl, heterocyclic, steroidal, etc. commonly found in pharmaceutically active primary amines RNH 2 or R*NH 2 . Such pharmaceutically active primary amines and intermediates and reagents for producing pharmaceutically or agriculturally active amines which may be prepared by the process of this invention include, but are not limited to: 2-diphenylmethylenebutylamine (Etifelmin), 3,4-dihydroxyphenethylamine (Dopamine), 3-α-amino-20-oxo-5-pregnane (Funtimine), 1-H-imidazole-4-ethaneamine (Ibrotamine), 3-(10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-ylidene)-N,N-dimethyl-1-propaneamine (Amitriptyline), 2-thiazolamine (2-aminothiazole), 2-pyridineamine (2-aminopyridine), 4-methyl-2-thiazolamine (Normotiroide), cyclohexylamine, O-3-amino-3-deoxy-α-D-lucopyranosyl-(1→6)-O-[2,6-diamino-2,3,4,6-tetradeoxy-α-D-erythrohexopyranosyl-(1→44)]-2-deoxy-D-streptamine (Dibekacin), p,α-dimethylphenylethylamine (Aptrol), p-fluorobenzenamine (p-fluoroanaline), α,α-dimethylphenylethylamine (Phentermine), 3,6-acridinediamine (Proflavine), and the like. While there are alternative methods for producing the key intermediates, RBMe 2 and R*BMe 2 , the process of this invention comprises producing either a primary amine or an optically active primary amine from the appropriate organodimethylborane to obtain excellent yields of the desired amine. This primary amine synthesis from organoborane intermediates provides a novel method of introducing an amine functionality into olefins in a regio- and stereoselective manner as illustrated below. Accordingly, one aspect of the invention comprises a process for producing primary amines represented by the formula R*NH 2 or RNH 2 from R*BMe 2 or RBMe 2 , respectively, wherein R* is an optically active [(+) or (-)] or substituted or unsubstituted, cyclic or acyclic organo group, and R is the same achiral organo group. The term "chiral" as used herein, refers to compounds which lack reflection symmetry, i.e. are not identical with their mirror images. The term "achiral" refers to compounds which possess reflection symmetry. In another embodiment, the present invention provides novel intermediates useful in the preparation of chiral primary amines of essentially 100% ee (ee=enantiomeric excess) represented by the formula R*BMe 2 and as well as a novel process for producing said intermediates wherein R* is a chiral organo group having up to 30 carbon atoms. The term essentially 100% ee refers to an enantiomeric excess of at least 95% of one of the members of an enantiomeric pair. The term "enantiomeric pair" refers to a pair of substances whose molecules are non-identical mirror images. The improved process for preparing chiral primary amines, R*NH 2 in high yields generally comprises heating a dimethylalkylborane, R*BMe 2 , wherein R* is a chiral organyl group, in a suitable solvent or solvents with an aminating agent, preferably O-hydroxylamine sulfonic acid, treating the reaction with aqueous base to liberate the primary amine, and isolation of same by distillation, or crystallization, or as the hydrochloride by treatment with ethereal HCl. The intermediate dimethylalkylboranes, R*BMe 2 are prepared by reacting a boronic ester, R*B(OEt) 2 with Grignard reagent, MeMgX. The boronic esters may be conveniently prepared by the procedure described by H. S. Brown, B. Singaram, J. Am. Chem. Soc., 106 1797 (1984). As used herein, the term "alkyl" refers to a substituted or unsubstituted, cyclic, polycyclic, or acyclic (straight or branched chain) alkyl group of from 3 to 30 carbon atoms. The process is broadly applicable to R=any organyl group, i.e. alkyl, aryl, heterocyclic, steroidal, commonly found in pharmaceutically active amines. The term "organyl", as used herein, refers to an aliphatic, alicyclic, steroidal or heterocyclic organic group. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The following examples further illustrate the present invention. All operations were initially carried out under a nitrogen atmosphere with oven-dried glassware. The spectra were obtained in an inert atmosphere. The 11 B NMR spectra were recorded on a Varian FT-80A spectrometer and the chemical shifts are in δ relative to the ethyl etherate of boron trifluoride, EE.BF 3 with chemical shifts downfield from EE.BF 3 assigned as positive. The 1 H NMR spectra were scanned on a Varian T-60 spectrometer, and the 13 C NMR spectra were obtained on a Varian FT-80 instrument. Chemical shifts, all in D 2 O, are relative to external Me 4 Si for 1 H and 13 C NMR spectra. Gas chromatographic analyses were carried out with a Varian 1400 FID instrument equipped with a Hewlett-Packard 3390A integrator/plotter using a 6 ft×0.125 in. column of 10% Carbowax 20M-2%KOH on Chromosorb W and an internal standard. Capillary gas chromatographic analyses were carried out with a Hewlett-Packard 5890 chromatograph. Optical rotations were measured on a Rudolph Polarimeter Autopol III. Unless otherwise indicated, optical rotations were measured at 20° C. Melting points are uncorrected. Tetrahydrofuran (THF) was distilled from sodium benzophenone ketyl. Anydrous diethyl ether (EE) was purchased from Mallincrodt, Inc. and was used directly. Hydroxylamine-O-sulfonic acid was obtained from Aldrich Chemical Co. and used as such. The boronic esters were prepared by the procedures described by Brown, H. C. et al., J. Am. Chem. Soc., 1985, 107, 4980. EXAMPLE 1 Preparation of Trans-2-methylcyclopentylamine A 50-mL centrifuge vial fitted with a rubber septum and magnetic stirring bar was charged with 5.6 mL of a 1.8M diethyl ether solution of lithium dimethylborohydride (10 mmol) and 1.1 mL of 1-methylcyclopentene (10.4 mmol) and cooled to 0° C. Neat chlorotrimethylsilane (1.3 mL, 10.2 mmol) was added with stirring. The reaction mixture was then stirred at 25° C. for 4 h. The 11 B NMR spectrum of the reaction mixture showed a signal at δ+86 due to the clean formation of the trialkylborane. The reaction mixture was centrifuged and the clear supernatant liquid was transferred via a double-ended needle to a 50-mL flask. The lithium chloride was washed with 2 mL of diethyl ether and the washing combined with the supernatant solution. The trialkylborane solution was diluted with 10 mL of tetrahydrofuran and hydroxylamine-O-sulfonic acid (2.26 g, 20 mmol) was added using a solid addition tube. Initial exothermic reaction was controlled by the rate of addition of HSA and by water bath cooling. The reaction mixture was stirred at 25° C. for 12 h and water (10 mL) was added. The 11 B NMR spectrum of the organic layer showed a peak at δ+31 due to the formation of boronic acid derivative. The reaction mixture was extracted with diethyl ether (20 mL) and the acidic aqueous layer was separated. The aqueous phase was cooled to 0° C., diethyl ether (20 mL) and n-dodecane (1.022 g, 6 mmol) was added and the reaction mixture was made strongly alkaline by adding aqueous NaOH (17M, 4 mL) with stirring. The organic phase was separated and the aqueous phase was extracted again with diethyl ether (20 mL) . The combined organic phase was dried over anhydrous MgSO 4 and an aliquot was withdrawn for GC analysis. The diethyl ether solution of the amine was reacted with ethereal HCl (2M, 6 mL) to precipitate the amine as its hydrochloride. The solid thus obtained was isolated, washed with diethyl ether (5×2 mL) and dried (25° C., 12 torr) to yield 1.1 g (81%, 99% ee): mp 182°-186° C. EXAMPLES 2-11 The following illustrative compounds were prepared following the procedure of Example 1: n-Octylamine hydrochloride, mp 201°-206° C., 85% yield, 99% ee, from 1-octene. Literature yields of this product range from 27% (from R 3 B, chloramine-T) , 32% (from R 3 B, in situ chloramine) and 69% (from R 3 B or R 2 BOR' and HSA). 2-Methyl-1-pentylamine hydrochloride, mp 140°-142° C., 95% yield, 99% ee, from 2-methyl-1-pentene. Reported literature yields of this product range from 24% (from R 3 B, in situ chloramine) to 58% (R 3 B or R 2 BOR'/chloramine). 2-Butylamine hydrochloride, m.p. 138°-140° C., 95% yield, 99% ee, from cis-2-butene. 3-Hexylamine hydrochloride, mp 228°-230° C., 92% yield, 99% ee, from cis-hexene. Reported literature yields of this product range from 48 to 52(from R 3 B or R 2 BOR'/HSA or chloramine). exo-2-Norbornylamine hydrochloride, mp 208° C. (dec), 99% yield, 99% ee, from 2-norbornene. Reported literature yields of this product, 24% from R 3 B and in situ chloramine. Cyclohexylamine hydrochloride, 94% yield, 99% ee, from cyclohexene. Reported literature yields, 24% from R 3 B/chloramine-T, 55% from R 3 B or R 2 BOR'/HSA. 3-Methyl-2-butylamine hydrochloride, mp 206° C., 208° C., 87% yield, 99% ee, from 3-methyl-2-butene. trans-2-Methylcyclohexylamine hydrochloride, mp 284° c. (dec), 78% yield, 99% ee, from 2-methylcyclohexene. Reported literature yields 8.5% from R 3 B or R 2 BOR'/chloramine, 45% from R 3 B or R 2 BOR'/HSA. trans-2-Methylcyclopentylamine hydrochloride, mp 182°-186° C., 81% yield, 99% ee, from 1-methylcyclopentene. Reported literature yields, 45% from R 3 B or R 2 BOR'/HSA. trans-2-Phenylcyclopentylamine hydrochloride, mp 136°-139° C., 73% yield, 99% ee, from 1-phenylcyclopentene. Reported literature yield, 45% from R 3 B or R 2 BOR'/HSA. The abundant availability of both optical forms of organyldimethylboranes R*BMe 2 , of this invention, coupled with the simple operating conditions for their conversion into chiral primary amines and easy workup, provides numerous advantages over the prior art. While the preparation of the above compounds has been given by way of example, there are no limitations on the organo R group. R may be aliphatic, such as octyl, 2-methylpentyl, etc.; alicyclic such as cyclooctyl, cyclododecyl, etc; bicyclic and polycyclic such as norbornenyl and decalyl; steroidal; aromatic such as phenyl, naphthyl, etc.; and heterocyclic, such as 3-tetrahydropyranyl, 2-furanylethyl, 2-thiophenylethyl, pyridinyl, and the like as illustrated by Examples 12-28. EXAMPLES 12-28 The following compounds are conveniently prepared in high yields by the method of Example 1. 3-Methyl-2-butylamine from 2-methyl-2-butene. 2-Methyl-1-pentylamine from 2 -methyl-1-pentene. 2-(p-Chlorophenyl)ethylamine from p-chlorostyrene. 2-Phenylethylamine from styrene. Cyclooctylamine from cyclooctene. 2-(4-Fluorophenyl)ethylamine from p-fluorostyrene. 2,4-Dimethyl-1-pentylamine from 2,4-dimethyl-1-pentene. 1-Hexadecylamine from 1-hexadecene. 11-Methoxyundecylamine from 11-methoxy-1-undecene. Ethyl 11-aminoundecanoate from ethyl 10-undecanoate. 1-Octyldecylamine from 1-octadecene. β-Naphthylamine from β-naphthalene boronic ester. 2,4,4-Trimethyl-1-pentylamine from 2,4,4-trimethyl-1-pentene. dl-2-Methyl-2-phenylethylamine from dl-α-methylphenylethylene. α,p-Dimethyl-2-phenylethylamine from α,p-dimethylstyrene. 2-(3-Pyridyl)-2-ethylamine from 3-vinylpyridine. 3-Aminopyrroline from 3-pyrroline. EXAMPLES 29-38 The following additional compounds are conveniently prepared in high yields by the method of Example 1. 2-(3,4-Dimethoxyphenyl)ethylamine from 3,4-dimethoxystyrene. 1,6-Diaminohexane from 1,5-hexadiene. 3-Aminoadipic acid from 3-hexenedioic acid. 5-Aminocholesteryl acetate from cholesteryl acetate. 4-Aminocholestane from 4-cholestene. 2-(3-Tetrahydropyranyl)ethylamine from 2-vinyl tetrahydropyran. 4-Aminooxacycloheptane from 4,5-dehydrooxacycloheptene. p-Fluorobenzeneamine from p-fluorobenzene boronic ester. cis-Myrtanylamine of 100% ee from beta-pinene of 100% ee. Isopinocampheylamine of 100% ee from alphapinene of 100% ee. The above description has been given by way of illustration. It will be apparent to those skilled in the art that modifications may be made without departing from the spirit and scope of the claimed invention.

A novel process for producing hindered and unhindered primary amines represented by the formula RNH 2 and R*NH 2 in high yields from novel intermediates RBMe 2 or R*BMe 2 wherein R is an organo group, R* is a chiral organo group. attached to boron, B is boron and Me is methyl.

CROSS REFERENCE TO RELATED APPLICATION This application is a divisional of U.S. patent application Ser. No. 13/216,362, filed on Aug. 24, 2011, which is a divisional of U.S. patent application Ser. No. 11/876,853, filed Oct. 23, 2007, now U.S. Pat. No. 8,042,070 issued on Oct. 18, 2011 the entire content and disclosures of which are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to methods and systems for analyzing and improving parametric yield in semiconductor device manufacturing. BACKGROUND OF THE INVENTION With continual scaling of dimensions in semiconductor devices and increase in the number of gates per chip, yield management in semiconductor manufacturing has become critical for economical and profitable operation of chip manufacturing facilities. Referring to FIG. 1 , past trends up to 65 nm technology node and forecast for future technology nodes show three components of yield loss including random defect yield loss, process limited yield loss, and parametric yield loss. Random defect yield loss is the yield loss due to random defects generated during manufacturing of a semiconductor chip. As feature sizes shrink in a semiconductor chip, functionality of the semiconductor chip is more readily disturbed by random defects generated during semiconductor processing steps, resulting in increased in the random defect yield loss in successive technology generation. While the impact of random defects on yield becomes more severe in successive technology generations, semiconductor chip manufacturing facility automation and process enhancements tend to reduce generation of random defects and mitigate the increase in the random defect yield loss. Process limited yield loss is the yield loss due to failure to control process parameters within specification. Process limited yield loss is thus due to an out-of-specification process parameter such as a thickness of a film, recess depth of a structure in a semiconductor substrate, and composition of a material. Inherent variability in semiconductor manufacturing processes causes some semiconductor chips to be out-of-specification for at least one process parameter. If the out of spec condition results in a short or open due then the chip is said to suffer from Process limited yield. Note, not all out of spec process parameters result in process limited yield. Increase in complexity of processing steps contributes to increase in the process limited yield loss, while improvement in process control tends to mitigate the impact of the processing steps on the process limited yield. Parametric yield loss is the yield loss due to the fraction of manufactured semiconductor chips that do not meet performance specifications among the chips that do not suffer from random defect yield loss or process limited yield loss. In other words, the chips affected by the parametric yield loss do not have random defects or out-of-specification process parameters that result in a hard failure, such as a short or an open. If an out of spec process parameter does not result in a hard failure, such as a short or an open, but does contribute to a deviation from modeled simulated behavior, and this deviation contributes to the chip not meeting the performance specification, then the chip is said to suffer from parametric or circuit limited yield. Additionally, at least one of design specification for the chip, which may be, for example, circuit timing or power consumption in on-state or in off-state, is out of specification. The cause of the failure of the chip to meet the design specification may not be attributed to the random defect yield loss or process limited yield loss, but is attributed to statistical distribution of performance of individual semiconductor devices in the semiconductor chip. The fraction of the number of chips that do not meet the device specification due to these reasons relative to the number of chips that are not affected by random defect yield loss or process limited yield loss is the parametric yield loss, which is sometimes also referred to as “circuit limited yield loss.” Thus parametric yield loss has both a random, statistical component and a systematic component. The impact of parametric yield loss increases in each succeeding technology node since more devices are integrated into a semiconductor chip. Recognizing the severe impact of the parametric yield loss, “design for manufacturability” (DFM) has been promoted as a concept. In essence, designers factor in potential yield impact of a particular design. While being a useful concept, design for manufacturability does not provide algorithms or methodology for systematically increasing parametric yield. Instead, it is a general recommendation to avoid designing circuits that may potentially cause performance problems. It should be recognized, however, that employing an aggressive design that may potentially cause parametric yield issues is necessary to design a high performance chip. The difficult part is to estimate the balance between a potential gain in performance of an aggressive design and increase in parametric yield, i.e., decrease in parametric yield loss, of a conservative design. Referring to FIG. 2 , an exemplary prior art method for designing a semiconductor chip is shown in a flow chart 200 . Referring to step 210 , functional requirements of a chip are defined. The chip may be a processor, a volatile or non-volatile memory chip, or a system-on-chip (SoC) having multiple embedded components. Functional requirements include the nature of the chip as well as performance goals of the chip. Referring to step 220 , an electronic system level (ESL) description is generated based on the functional requirements of the chip. Electronic system level description and verification is a design methodology that focuses on the higher abstraction level without regard to lower level implementation. The goal of the ESL description is to enhance the probability of a successful implementation of functionality. Appropriate abstractions are utilized to generate a global level understanding of the chip to be designed. To this end, a high level programming language such as C or C++ is employed as an abstract modeling language to model the behavior of the entire system to be contained in a chip. Typically, this process is manual, although automation of this step by electronic design automaton (EDA) has been under investigation. Referring to step 230 , a register transfer level (RTL) description is generated from the electronic system level (ESL) description in the next chip design phase. Register transfer level (RTL) description is a description of a semiconductor chip design in terms of its operation. Specifically, the behavior of a circuit is defined in terms of data transfer, or flow of signals between hardware registers in the RTL description. Logical operations are performed on the data. A hardware description language (HDL) such as Verilog™ or VHDL™ is employed to create high-level representations of a circuit, from which lower level representations and ultimately actual discrete devices and wiring may be derived. Referring to step 240 , logic synthesis is performed to convert the RTL description in the form of the hardware description language (HDL) into a gate level description of the chip by a logic synthesis tool. Specifically, the gate level description is a discrete netlist of logic gate primitives, or “Boolean logic primitives.” Referring to step 250 , placement and routing tools utilize the results of the logic synthesis to create a physical layout for the chip. Logic gates and other device components of the netlist are placed in a “layout,” or a chip design. The chip design is then routed, i.e., wires are added to the placed components to provide interconnection between the components' signal and power terminals. Typically, this process is performed with tools employing electronic design automation (EDA) features. Referring to step 260 , power analysis and timing analysis is performed. It is noted that the exemplary prior art method scales power generation by scaling of a nominal device or multiple nominal devices. In other words, only the device type and device size are employed in the power analysis. The power analysis and the timing analysis are performed to check the chip design for functionality. Referring to step 270 , the chip design is analyzed to extract design specification. For example, timing analysis may be employed at this point to specify timing delay and expected chip operating frequency. Further, nominal leakage currents are estimated to specify power consumption of the chip. Referring to FIG. 3 , an exemplary prior art semiconductor chip manufacturing sequence including the steps of chip design is shown in a flow chart 300 . Referring to step 310 , a semiconductor chip design is provided as described in steps 210 - 260 of the flow chart 200 in FIG. 2 . Referring to step 312 , design specification is generated for the chip as in step 270 of the flow chart 200 in FIG. 2 . Referring to step 320 , data preparation is performed on the chip design to generate various mask levels, which may then be transmitted to a “mask house,” or a mask fabrication facility to initiate fabrication of physical masks to be employed in manufacturing of semiconductor chips. Various “design comps,” or compensations to instances in design levels may be performed as part of data preparation. The mask house manufactures physical masks that may be subsequently employed in lithographic tools according to the mask level designs. Referring to step 330 , semiconductor chips are manufactured in a semiconductor chip fabrication facility. Typically, the semiconductor chips are manufactured on a semiconductor substrate such as a silicon substrate. Various semiconductor processing steps including lithography, deposition, and etching are employed. Referring to step 340 , the manufactured semiconductor chips are tested and characterized for functionality. Dysfunctional chips are sorted out. Operating frequency, on-state leakage, and off-state leakage are measured on functional chips. Referring to step 350 , parametric yield, i.e., circuit limited yield (CLY), is calculated for the group of semiconductor chips that do not suffer from random defect yield loss or process limited yield loss. Assuming a normal scenario in which the random defect yield loss and the process limited yield loss of the manufacturing process are within expected ranges, delivery of sufficient number of chips to a customer depends on the parametric yield loss. If the parametric yield exceeds a minimum parametric yield target value, sufficient number of chips meeting the design specification may be shipped to a customer, as shown in the step 360 . If the parametric yield is below a minimum target value, not enough chips meeting the design specification are available for shipping, as shown in step 379 . In this case, few courses of systematic action are available to the semiconductor chip manufacturing facility for investigation of the source of the depressed parametric yield. While some methods are known in the art for diagnosing depressed process limited yield such as sorting the semiconductor chips by processing history or process variations, depressed parametric yield is much more difficult to investigate since the depressed parametric yield is correlated to specific design features of the semiconductor chip. In financial perspective, when a semiconductor chip manufacturing facility commits to manufacture semiconductor chips based on an unknown chip design, the level of parametric yield loss is unpredictable from the perspective of the semiconductor chip manufacturing facility, while a customer generating a new chip design may have a vague idea of the level of expected parametric yield. Neither party has a good understanding on what level of parametric yield should be expected on the new chip design. Thus, lack of precise estimation of the parametric yield on the new chip design exposes a semiconductor chip manufacturing facility to a financial uncertainty, while the customer submitting the new design is not provided with any guidance on how to improve the design to enhance the parametric yield. In view of the above, there exists a need for a system and methods for analyzing and managing parametric yield on a semiconductor chip during a chip design phase. Further, there exists a need for a system and methods for analyzing and managing parametric yield on a semiconductor chip during a chip manufacturing phase or after a depressed parametric yield is observed in testing. Yet further, there exists a need for a system and methods for predicting parametric yield at various levels to compare with observed data so that any anomaly in design may be found during testing of manufactured semiconductor chips. SUMMARY OF THE INVENTION The present invention addresses the needs described above by providing a system and methods for analyzing and managing parametric yield on a semiconductor chip during a chip design phase, a chip manufacturing phase, and after a depressed parametric yield is observed as well as a system and methods for comparing observed parametric yield with a parametric yield model. In the present invention, impact on parametric performance of physical design choices for transistors is scored for on-current and off-current of the transistors. Design parameters affecting the on-current and off-current of the transistors include dimensions of various features of the transistor relative to nearby structures as well as across-chip-length-variation (ACLV) and corner rounding stress effects. The impact of the design parameters are incorporated into parameters that measure predicted shift in mean on-current and mean off-current and parameters that measure predicted increase in deviations in the distribution of the on-current and the off-current. Statistics may be taken at a cell level, a block level, or a chip level to optimize a chip design in a design phase, or to predict changes in parametric yield during manufacturing or after a depressed parametric yield is observed. Further, parametric yield and current level may be predicted region by region and compared with observed thermal emission to pinpoint any anomaly region in a chip to facilitate detection and correction in any mistakes in chip design. According to an aspect of present invention, a system for designing a semiconductor chip is provided, which comprises: threshold voltage adder calculation means for calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device; and parametric yield estimation means for estimating a parametric yield estimation value of the subset of the semiconductor chip design, wherein the parametric yield estimation value is based on the calculated threshold voltage adder. In one embodiment, the system further comprises at least one of: average on-current adder calculation means for calculating an average on-current adder for the subset of the semiconductor chip design; and average off-current adder calculation means calculating an average off-current adder for the subset of the semiconductor chip design, wherein the average on-current adder is an average deviation of on-current of the subset from a scaling-estimated on-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset, and wherein the average off-current adder is an average deviation of off-current of the subset from a scaling-estimated off-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset, and wherein the parametric yield estimation value is based on at least one of the average on-current adder and the average off-current adder. In another embodiment, the subset comprises a cell containing one functional semiconductor device unit within the semiconductor chip design a plurality of semiconductor device units within the semiconductor chip design. In even another embodiment, the design parameters of the subset comprises at least one of positional relationship between an element of the subset and another element of the subset and positional relationship between an element of the subset and another element of another subset in the semiconductor chip design. In yet another embodiment, the system further comprises: logic synthesis means for performing logic synthesis to generate a netlist of the semiconductor chip design, wherein the semiconductor design is the netlist; and flow control means for controlling flow of a sequence of operating the system, wherein the flow control means directs the flow to a step in which the netlist is modified if the parametric yield estimation value does not exceeds a target value. In still another embodiment, the system further comprises: placement and routing means for placing and routing a netlist of the semiconductor chip design to generate a chip layout, wherein the semiconductor design is the chip layout; and flow control means for controlling flow of a sequence of operating the system, wherein the flow control means directs the flow to a step in which the chip layout is modified if the parametric yield estimation value does not exceeds a target value. In still yet another embodiment, the system further comprises at least one of: incremental on-current deviation calculation means for calculating an incremental on-current deviation for the subset of the semiconductor chip design, wherein the incremental on-current deviation is an increment in statistical deviation of on-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of on-current, which is obtained by scaling of statistical deviation of on-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset; and incremental off-current deviation calculation means for calculating an incremental off-current deviation for the subset of the semiconductor chip design, wherein the incremental off-current deviation is an increment in statistical deviation of off-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of off-current, which is obtained by scaling of statistical deviation of off-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of devices in the subset. In a further embodiment, the system further comprises at least one of: on-current distribution calculation means for calculating statistical distribution of on-current within the subset; and off-current distribution calculation means for calculating statistical distribution of off-current within the subset. In an even further embodiment, the system further comprises at least one of: on-state temperature distribution calculation means for calculating on-state temperature distribution of a semiconductor chip manufactured with the semiconductor design; and off-state temperature distribution calculation means for calculating off-state temperature distribution of the semiconductor chip manufactured with the semiconductor design. In a yet further embodiment, the on-state temperature distribution is calculated based on the statistical distribution of the on-current within the subset, and wherein the off-state temperature distribution is calculated based on the statistical distribution of the off-current within the subset. In another aspect of the present invention, a system for analyzing parametric yield of a semiconductor chip design is provided, which comprises: threshold voltage adder calculation means for calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device; parametric yield estimation means for estimating a parametric yield estimation value of the subset of the semiconductor chip design, wherein the parametric yield estimation value is based on the calculated threshold voltage adder; a tester for generating at least one measured parametric yield value by testing at least one semiconductor chip that is manufactured according to the semiconductor chip design; and parametric yield comparison means for comparing the parametric yield estimation value and the at least one measured parametric yield value. In one embodiment, the design parameters of the subset comprises at least one of positional relationship of an element of the subset to another element of the subset and positional relationship of an element of the subset to another subset in the semiconductor chip design. In another embodiment, the system further comprises at least one of: incremental on-current deviation calculation means for calculating an incremental on-current deviation for the subset of the semiconductor chip design, wherein the incremental on-current deviation is an increment in statistical deviation of on-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of on-current, which is obtained by scaling of statistical deviation of on-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset; and incremental off-current deviation calculation means for calculating an incremental off-current deviation for the subset of the semiconductor chip design, wherein the incremental off-current deviation is an increment in statistical deviation of off-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of off-current, which is obtained by scaling of statistical deviation of off-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of devices in the subset. In even another embodiment, the system comprises at least one of: on-current distribution calculation means for calculating statistical distribution of on-current within the subset; and off-current distribution calculation means for calculating statistical distribution of off-current within the subset. In yet another embodiment, the system further comprises: a measured process parameter database that stores measured process parameter values that are measured during manufacturing of the at least one semiconductor chip; a process model for correlating variations in the measured process parameter values with the at least one measured parametric yield value; and process model fitting means for fitting discrepancy between the parametric yield estimation value and the at least one measured parametric yield value with the measured process parameter values to improve accuracy of the process model. In still another embodiment, the system further comprises parametric estimation value change simulation means for simulating a change in the parametric estimation value in response to changes in the design parameter. According to yet another aspect of the present invention, a system for identifying a location of anomalous functionality on a semiconductor chip is provided, which comprises: at least one of on-current distribution calculation means for calculating spatial distribution of on-current within the semiconductor chip and off-current distribution calculation means for calculating spatial distribution of off-current within the semiconductor chip; current-to-temperature conversion means for converting one of the spatial distribution of on-current and the spatial distribution of the off-current into an estimated spatial temperature distribution map; and temperature distribution measurement means for generating a measured temperature distribution map of the semiconductor chip in an on-state or an off-state. In one embodiment, the system comprises threshold voltage adder calculation means for calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device, wherein at least one of the spatial distribution of on-current and the spatial distribution of off-current is based on the calculated threshold voltage adder. In another embodiment, the system further comprises: a measured process parameter database that stores measured process parameter values that are measured during manufacturing of the semiconductor chip; a process model for correlating the measured process parameter values with the measured temperature distribution map; and process model fitting means for fitting discrepancy between the measured temperature distribution map and at least one of the spatial distribution of on-current and the spatial distribution of off-current to improve accuracy of the process model. In yet another embodiment, the system further comprises temperature distribution comparison means for comparing the estimated spatial temperature distribution map with the measured temperature distribution map of the semiconductor chip. According to even another aspect of the present invention, a method of designing a semiconductor chip is provided, which comprises: calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device; and estimating a parametric yield estimation value of the subset of the semiconductor chip design, wherein the parametric yield estimation value is based on the calculated threshold voltage adder. In one embodiment, the method comprises at least one of: calculating an average on-current adder for the subset of the semiconductor chip design; and calculating an average off-current adder for the subset of the semiconductor chip design, wherein the average on-current adder is an average deviation of on-current of the subset from a scaling-estimated on-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset, and wherein the average off-current adder is an average deviation of off-current of the subset from a scaling-estimated off-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset, and wherein the parametric yield estimation value is based on at least one of the average on-current adder and the average off-current adder. In another embodiment, the method further comprises: performing logic synthesis to generate a netlist of the semiconductor chip design, wherein the semiconductor design is the netlist; and controlling flow of a sequence of operating the system, wherein the flow control means directs the flow to a step in which the netlist is modified if the parametric yield estimation value does not exceeds a target value. In even another embodiment, the method further comprises: placing and routing a netlist of the semiconductor chip design to generate a chip layout, wherein the semiconductor design is the chip layout; and controlling flow of a sequence of operating the system, wherein the flow control means directs the flow to a step in which the chip layout is modified if the parametric yield estimation value does not exceeds a target value. In yet another embodiment, the method further comprises at least one of: calculating an incremental on-current deviation for the subset of the semiconductor chip design, wherein the incremental on-current deviation is an increment in statistical deviation of on-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of on-current, which is obtained by scaling of statistical deviation of on-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset; and calculating an incremental off-current deviation for the subset of the semiconductor chip design, wherein the incremental off-current deviation is an increment in statistical deviation of off-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of off-current, which is obtained by scaling of statistical deviation of off-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of devices in the subset. In still another embodiment, the method further comprises at least one of: calculating statistical distribution of on-current within the subset; and calculating statistical distribution of off-current within the subset. In still yet another embodiment, the method further comprises at least one of: calculating on-state temperature distribution of a semiconductor chip manufactured with the semiconductor design; and calculating off-state temperature distribution of the semiconductor chip manufactured with the semiconductor design. According to still another aspect of the present invention, a method of analyzing parametric yield of a semiconductor chip design is provided, which comprises: calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device; estimating a parametric yield estimation value of the subset of the semiconductor chip design, wherein the parametric yield estimation value is based on the calculated threshold voltage adder; generating at least one measured parametric yield value by testing at least one semiconductor chip that is manufactured according to the semiconductor chip design; and comparing the parametric yield estimation value and the at least one measured parametric yield value. In one embodiment, the method further comprises at least one of: calculating an incremental on-current deviation for the subset of the semiconductor chip design, wherein the incremental on-current deviation is an increment in statistical deviation of on-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of on-current, which is obtained by scaling of statistical deviation of on-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset; and calculating an incremental off-current deviation for the subset of the semiconductor chip design, wherein the incremental off-current deviation is an increment in statistical deviation of off-current of the subset of the semiconductor chip deign from a scaling-estimated statistical deviation of off-current, which is obtained by scaling of statistical deviation of off-current of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of devices in the subset. In another embodiment, the method further comprises at least one of: calculating statistical distribution of on-current within the subset; and calculating statistical distribution of off-current within the subset. In even another embodiment, the method further comprises: storing measured process parameter values that are measured during manufacturing of the at least one semiconductor chip; correlating variations in the measured process parameter values with the at least one measured parametric yield value with a process model; and fitting discrepancy between the parametric yield estimation value and the at least one measured parametric yield value with the measured process parameter values to improve accuracy of the process model. In yet another embodiment, the method further comprises simulating a change in the parametric estimation value in response to changes in the design parameter. According to still yet another aspect of the present invention, a method of identifying a location of anomalous functionality on a semiconductor chip is provided, which comprises: calculating at least one of spatial distribution of on-current within the semiconductor chip and spatial distribution of off-current within the semiconductor chip; converting one of the spatial distribution of on-current and the spatial distribution of the off-current into an estimated spatial temperature distribution map; and generating a measured temperature distribution map of the semiconductor chip in an on-state or an off-state. In one embodiment, the method further comprises calculating a calculated threshold voltage adder for a device within a subset of a semiconductor chip design including an effect of at least one design parameter of the subset other than inherent geometric dimensions and inherent characteristics of the device, wherein at least one of the spatial distribution of on-current and the spatial distribution of off-current is based on the calculated threshold voltage adder. In another embodiment, the method further comprises: storing measured process parameter values that are measured during manufacturing of the semiconductor chip; correlating the measured process parameter values with the measured temperature distribution with a process model; and fitting discrepancy between the measured temperature distribution map and at least one of the spatial distribution of on-current and the spatial distribution of off-current to improve accuracy of the process model. In yet another embodiment, the method further comprises comparing the estimated spatial temperature distribution map with the measured temperature distribution map of the semiconductor chip, wherein a location of discrepancy is identified as the location of anomalous functionality. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing trends of various yield loss components at successive semiconductor technology nodes. FIG. 2 is a flow chart for a prior art method for generating a semiconductor chip design. FIG. 3 is a flow chart for a prior art method for manufacturing semiconductor chips based on a semiconductor chip design. FIG. 4 is a graph showing an exemplary method calculating a threshold voltage (Vt) adder based on proximity of a transistor to an adjacent well as well as a width of the transistor according to the present invention. FIG. 5 is a flow chart for operating an exemplary system for designing a semiconductor device that incorporates parametric yield analysis according to the present invention. FIG. 6 is a flow chart for operating an exemplary system for analyzing parametric yield of a semiconductor design according to the present invention. FIG. 7 is a flow chart for operating an exemplary system for identifying a location of anomalous functionality on a semiconductor chip according to the present invention. FIG. 8 is an estimated spatial temperature distribution map for a semiconductor chip derived from a corresponding semiconductor chip design according to the present invention. FIG. 9 is a measured temperature distribution map measured on a semiconductor chip. DETAILED DESCRIPTION OF THE INVENTION As stated above, the present invention relates to methods and systems for analyzing and improving parametric yield in semiconductor device manufacturing, which are now described in detail with accompanying figures. It is noted that like and corresponding elements mentioned herein and illustrated in the drawings are referred to by like reference numerals. In a transistor, the distance between source and drain regions of the transistor and an edge of a well containing the source and drain regions affects the threshold voltage of the transistor. Such effects are known in the art as well proximity effects. U.S. Pat. No. 7,089,513 to Bard et al. describes well proximity effects and is herein incorporated by reference. Due to well proximity effects, threshold voltages of the p-type field effect transistors of the same category that differ only by the size, i.e., the width of the gate that is the dimension of an active area abutting a gate dielectric along the direction perpendicular to the direction of current flow, are affected not only by the size of the p-type field effect transistors but also by the proximity of the edge of the active area to a nearby n-type well. In general, the threshold voltage of a transistor depends not only on inherent geometric dimensions and inherent characteristics and composition of components of the transistor but also on design parameters of a subset of a semiconductor chip including the transistor. The design parameters contain at least one element that is external to the transistor. As an example, the well proximity effect involves design parameters of a subset of a semiconductor chip, in which the subset includes the transistor and the well containing the transistor. The location of the edge of the well is not a component of the transistor. Therefore, the edge of the well is external to the transistor. However, a design parameter, which in this case is the distance between the source and drain regions and the edge of the well, affects the threshold voltage of the transistor. Therefore, a design parameter that of the subset of the semiconductor chip other than inherent geometric dimensions and inherent characteristics of the transistor affects characteristics of the transistor, and specifically, affects the threshold voltage of the transistor. Referring to FIG. 4 , a graph showing variations in threshold voltage (Vt) adder values for p-type field effect transistors due to proximity to an n-well edge as well as the size of the p-type field effect transistors. The threshold voltage (Vt) adder is an average deviation of the threshold voltage of a transistor from a nominal transistor. A nominal transistor is an idealized transistor representing a class of transistors having a similar feature. For example, a nominal transistor may have a fixed gate length and a fixed gate width and may be embedded in a semiconductor chip in a specified environment. The specified environment may be a nested environment, which is an environment in which a plurality of nominal transistor are arranged in a one-dimensional or a two-dimensional array, or may be an isolated environment, which is an environment in which the nominal device is isolated by surrounding electrical isolation structures. Due to statistical nature of semiconductor processing steps, and especially due to stochastic nature of ion implantation processing steps, the threshold voltage of a nominal transistor has a statistical distribution. A nominal threshold voltage of a nominal device refers to a statistical average of a threshold voltage distribution measured on an ensemble of nominal devices. Threshold voltage distribution inherently has a non-zero deviation for the threshold voltage for the nominal devices. In case the threshold voltage distribution has a form of a Gaussian distribution, a standard deviation may be defined. Since actual threshold voltage distributions are typically Gaussian, presence of a standard deviation in the threshold voltage distributions is herein assumed. Of the two variables used in this graph, the first variable is a gate width, which is the width of the overlap of the gate of the transistor with the active area of the transistor that is measured in the direction perpendicular to the current flow between the source and the drain. The gate width is a variable derived from inherent geometric dimensions and inherent characteristics of the p-type field effect transistors. The second variable is well edge proximity, which is the distance between the source and drain regions of the p-type transistor to a nearest edge of the n-well that contains the p-type filed effect transistor is a variable that is external to the p-type field effect transistors. Thus, the well edge proximity may not be derived from inherent geometric dimensions and inherent characteristics of a p-type field effect transistor alone. Extraction of the second parameter requires data from a subset of a semiconductor chip design such that the subset contains a component, which in this case is an n-well, other than the p-type field effect transistor. Thus, access to, and consideration of, design parameters of a subset of a semiconductor chip design enables calculation of expected shift in transistor characteristics including any deviation in the threshold voltage due to the design parameters internal and external to the transistor. For a given width of the gate and a given value for well edge proximity, a distribution of values is observed in measured threshold voltage of a transistor. The difference between measured threshold voltage of a transistor having inherent geometric dimensions and inherent characteristics and design parameters of a subset of a semiconductor chip design external to the transistor and the nominal threshold voltage of a nominal transistor is the threshold voltage (Vt) adder. The design parameters that may not be directly obtained from the design of the transistor alone are herein referred to as external design parameters of the transistor. The design parameters that may be obtained from the design of the transistor alone are herein referred to as inherent design parameters of the transistor. Due to the statistical nature of the effect of the inherent and external design parameters and threshold voltage distribution of nominal devices, the threshold voltage adder has a distribution of for each set of design parameters. Statistical quantities may be defined for the threshold voltage adder for each set of design parameters. In the case of FIG. 4 , solid curves represent a fit for nominal threshold voltage adder values for the p-type field effect transistor for the specified design parameters, i.e., the gate width and the well edge proximity. Nominal threshold voltage adder is an average shift in the threshold voltage from the nominal threshold voltage due to the inherent and external design parameters. The nominal threshold voltage adder may be positive or negative. Other statistical quantities such as deviation of threshold voltage adder and various percentile values, e.g., 1 percentile values, 5 percentile values, 95 percentile values, 99 percentile values, as well as maximum and minimum observed values for a given number of samples may be measured and mathematically fitted. The deviation of threshold voltage adder is the deviation of the distribution of the threshold voltage adder, which is the distribution of the shift in the threshold voltage from the nominal threshold voltage. In general, the effect of inherent design parameters and external design parameters is modeled by building a macro, or a test structure, that measures the effect of the inherent design parameters and external design parameters on manufactured semiconductor test chips. Methods of measuring the effect of inherent design parameters such as gate length and gate width are known in the art. According to the present invention, the effect of external design parameters are also measured and incorporated into a compact model, which is a model for predicting performance of a semiconductor device such as a transistor. The external design parameters may include positional relationship of an element of a subset of a semiconductor chip design that contains a device to be characterized and another element of the subset of the semiconductor chip design. One of the two elements may, or may not, be a component of the device. For example, the device may be a transistor, the subset may comprise the transistor and a well in which the transistor is placed, the element may be source and drain regions, and the other element may be an edge of the well. In this case, one of the two elements is a component of the transistor. Alternately, the external design parameters may include positional relationship of an element of a subset of a semiconductor chip design that does not contain a device to be characterized and another element of the subset of the semiconductor chip design that does not contain the device. For example, the device may be a transistor, the subset may comprise the device and two stress-generating structure located adjacent to the device, and each of the two elements may be one of the two stress-generating structures. In this case, none of the two elements comprises a component of the transistor. Yet alternately, the external design parameters may include positional relationship of a first element of a first subset of a semiconductor chip design that contains a device to be characterized and a second element of a second subset of the semiconductor chip design. The first element may, or may not, be a component of the device. For example, the device may be a transistor, the first subset may comprise the transistor and a first well in which the transistor is placed, the first element may be source and drain regions, the second subset may comprise another well located adjacent to the first well, and the second element may be an edge of the second well. In this case, the first element is a component of the device. In another example, the device may be a transistor, the first subset may comprise the transistor and a first well in which the transistor is placed, the first element may be an edge of the first well, the second subset may comprise another well located adjacent to the first well, and the second element may be an edge of the second well. In this case, the first element is not a component of the device. Non-limiting examples of external design parameters that may be employed to evaluate the effect on the threshold voltage adder include distance and orientation of well edges relative to an element of a transistor, distance and orientation of edges of stress-generating structures such as embedded stress-generating materials or stress-generating dielectric liners relative to an element of the transistor, and distance and orientation of elements of other semiconductor devices relative to the transistor and among themselves. Further, power density during an on-state or an off-state of the semiconductor chip within the subset of the semiconductor chip design may be employed to estimate the temperature of the portion of the semiconductor chip design to assess the impact of ambient temperature on the threshold voltage adder. The effect of the inherent design parameters and external design parameters is then incorporated into threshold voltage adder calculation means such as a compact model. The compact model according to the present invention has the capability to calculate nominal threshold voltage adder and other statistical quantities such as deviation of threshold voltage adder in addition to other device characteristics prediction capabilities known in the art. The threshold voltage adder calculation means may alternately be a program dedicated to calculation of the threshold voltage adder values. The threshold voltage adder thus calculated is herein referred to as “calculated threshold voltage adder” to be differentiated from measured values of threshold voltage adder. It is noted that the calculated threshold voltage adder is not necessarily a scalar value for a functional semiconductor device, but preferably and generally, a distribution having an average value and associated statistical quantities such as deviations and quantiles. A “mean calculated threshold voltage adder” is a mean of the calculated threshold voltage adder, which is a distribution. A “deviation of calculated threshold voltage adder” is a standard deviation of the calculated threshold voltage adder. Mathematically, Δ ⁢ ⁢ Vt mean = ∑ i = 1 n ⁢ Δ ⁢ ⁢ Vt i mean , and ( Equation ⁢ ⁢ 1 ) σ VT 2 - σ Vt_ ⁢ 0 2 = ∑ i = 1 n ⁢ Δ ⁡ ( σ Vt_i 2 ) , ( Equation ⁢ ⁢ 2 ) wherein ΔVt mean is the mean calculated threshold voltage adder of a device, i.e., the transistor on which the calculated threshold voltage adder as a distribution is calculated, n is the total number of the design parameters that are related to the threshold voltage adder of the transistor, and ΔVt i mean is a contribution of the i-th design parameter within the subset to the mean calculated threshold voltage adder, and wherein σ Vt 2 is the variance (which is the square of the standard deviation) of the threshold voltage of the transistor on which the calculated threshold voltage adder is calculated, σ Vt — 0 2 is the variance of the threshold voltage of a nominal device, Δ(σ Vt — i 2 ) is a change in the variance of the threshold voltage of the nominal device that is scaled to the size of the transistor due to the i-th design parameter within the subset. Each of the Δ(σ Vt — i 2 ) may be positive or negative, i.e., the effect of the i-th design parameter may be to reduce or to increase the variance of the transistor on which the effect of the i-th design parameter is calculated. The design parameters include inherent and external design parameters of the transistor. Further, the calculation of the calculated threshold voltage adder may be repeated to include all semiconductor devices within a subset of a semiconductor chip design that includes a functional semiconductor device. The subset of the semiconductor chip design includes at least one functional semiconductor device. In general, the subset of the semiconductor chip design may include only one functional semiconductor device, or a “cell,” an array of functional semiconductor devices within the semiconductor chip design, a functional block containing a plurality of semiconductor devices of different types, or the entirety of the semiconductor chip. The calculation of the calculated threshold voltage adder may be repeated for each subset of the semiconductor chip design to encompass the entirety of the semiconductor chip design. Statistical data is extracted from the calculated threshold voltage adders for the subset of the semiconductor chip design. Depending on the nature of the subset of the semiconductor chip design, the statistical data on the calculated threshold voltage adders may be for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Parametric yield estimation means is then employed to estimate a parametric yield estimation value for each subset of the semiconductor chip design. The estimation of the parametric yield estimation value may be based directly on the statistical data on the calculated threshold voltage adders for each subset of the semiconductor chip design. Alternately, intermediate quantities may be calculated from the data set on the calculated threshold voltage adders to generate a more sophisticated and accurate estimation of the parametric yield estimation value. Parametric yield estimation means may be a computer program that compares overall threshold voltage distribution with a projected parametric yield value. The parametric yield estimation means includes a yield model that projects or estimates parametric yield of a subset of a semiconductor chip design based on statistical data extracted from the calculated threshold voltage adders or based on the data set of the calculated threshold voltage adders of the subset of the semiconductor chip design. The projected value, or the estimated value, of the parametric yield is the projected parametric yield value for the subset of the semiconductor chip design. Thus, the projected parametric yield value may be for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. In case the projected parametric yield value is calculated by employing the full data set of the calculated threshold voltage adders, current based performance deviation measurement quantities may be derived. Current based performance deviation measurement quantities may include an average on-current adder and/or an average off-current adder for the subset of the semiconductor chip design. An average on-current adder and/or an average off-current adder may be calculated for a subset of a semiconductor chip design. The average on-current adder and/or the average off-current adder may be positive or negative. The subset may comprise a device such as a transistor. In case the subset comprises a plurality of devices, calculation of an average on-current adder and/or an average off-current adder may be repeated for every device in the subset. The average on-current adder and/or the average off-current adder of the subset in this case is a mathematical average, which could be a mean, a median, or a mode, of the set of average on-current adders and/or the set of average off-current adders of the entirety of the subset of the semiconductor chip design. Mathematically, Δ ⁢ ⁢ I_on ave = ∑ i = 1 n ⁢ Δ ⁢ ⁢ I_on i ave , and ( Equation ⁢ ⁢ 3 ) Δ ⁢ ⁢ I_off ave = ∑ i = 1 n ⁢ ΔI_off i ave , ( Equation ⁢ ⁢ 4 ) wherein ΔI_on ave is the average on-current adder of a device, i.e., the transistor on which the on-current adder as a distribution is calculated, n is the total number of the design parameters that are related to the threshold voltage adder of the transistor, and ΔI_on i ave is a contribution of the i-th design parameter within the subset to the average on-current adder, and wherein ΔI_off ave is the average off-current adder of the transistor, and ΔI_off i ave is a contribution of the i-th design parameter within the subset to the average off-current adder. As noted above, the average may be a mean, a median, or a mode. The design parameters include inherent and external design parameters of the transistor. Calculation of the average on-current adder for the subset and the average off-current adder for the subset employs average on-current adder calculation means and average off-current calculation means, respectively. On-current adder calculation means and/or off-current adder calculation means may be a stand-alone program that is dedicated to calculation of the average on-current adder and the average off-current adder, and may reside in a computer. Alternately, the on-current adder calculation means and/or the off-current adder calculation means may be integrated into a system, which may include other automated programs, for designing a semiconductor chip or for diagnosing parametric yield of semiconductor chips. The average on-current adder is an average deviation of on-current of the subset from a scaling-estimated on-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset. The average off-current adder is an average deviation of off-current of the subset from a scaling-estimated off-current, which is obtained by scaling of at least one nominal device, due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset. The parametric yield estimation value is based on at least one of the average on-current adder of the subset and the average off-current adder of the subset. The average on-current adder may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Likewise, the average off-current adder may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. In addition, current based performance deviation measurement quantities may include an average on-current adder and/or an average off-current adder for the subset of the semiconductor chip design. An incremental on-current deviation and/or an incremental off-current deviation may be calculated for a device for a subset of a semiconductor chip design. The incremental on-current deviation and/or the incremental off-current deviation may be positive or negative. The subset may comprise a device such as a transistor. In case the subset comprises a plurality of devices, calculation of an incremental on-current deviation and/or an incremental off-current deviation may be repeated for every device in the subset. Mathematically, Δσ I_on = [ σ I_on 2 - σ I_on ⁢ _ ⁢ 0 2 ] 1 / 2 = [ ∑ i = 1 n ⁢ Δ ⁡ ( σ I_on ⁢ _i 2 ) ] 1 / 2 , ⁢ if ⁢ ⁢ σ I_on 2 - σ I_on ⁢ _ ⁢ 0 2 > 0 , ⁢ or ( Equation ⁢ ⁢ 5 ⁢ a ) Δσ I_on = -  σ I_on 2 - σ I_on ⁢ _ ⁢ 0 2  1 / 2 = -  ∑ i = 1 n ⁢ Δ ⁡ ( σ I_on ⁢ _i 2 )  1 / 2 , ⁢ if ⁢ ⁢ σ I_on 2 - σ I_on 2 - σ I_on ⁢ _ ⁢ 0 2 < 0 , ( Equation ⁢ ⁢ 5 ⁢ b ) wherein Δσ I — on is the incremental on-current deviation of a device, i.e., the transistor on which the on-current as a distribution is calculated, σ I — on 2 is the variance of the on-current of the transistor, n is the total number of the design parameters that are related to the threshold voltage adder of the transistor, σ I — on — 0 2 is a scaled variance of the on-current a nominal transistor that is scaled to match the size of the transistor on which the on-current distribution is calculated, and wherein Δ(σ I — on — i 2 ) is a contribution of the i-th design parameter to the change of the variance of the on-current of the transistor. Since σ I — on 2 −σ I — on — 0 2 may be positive or negative, the change in the on-current deviation may be positive or negative. In other words, the incremental on-current deviation, which measures changes in the standard deviation due to the collective set of the design parameters of the transistor, may be an increment or decrement. The design parameters include inherent and external design parameters of the transistor. Likewise, Δσ I_off = [ σ I_off 2 - σ I_off ⁢ _ ⁢ 0 2 ] 1 / 2 = [ ∑ i = 1 n ⁢ Δ ⁡ ( σ I_off ⁢ _i 2 ) ] 1 / 2 , ⁢ if ⁢ ⁢ σ I_off 2 - σ I_off ⁢ _ ⁢ 0 2 > 0 , ⁢ or ( Equation ⁢ ⁢ 6 ⁢ a ) Δσ I_off = -  σ I_off 2 - σ I_off ⁢ _ ⁢ 0 2  1 / 2 = -  ∑ i = 1 n ⁢ Δ ⁡ ( σ I_off ⁢ _i 2 )  1 / 2 , ⁢ if ⁢ ⁢ σ I_off 2 - σ I_off ⁢ _ ⁢ 0 2 < 0 , ( Equation ⁢ ⁢ 6 ⁢ b ) wherein Δσ I — off is the incremental off-current deviation of a device, i.e., the transistor on which the on-current as a distribution is calculated, σ I — off 2 is the variance of the off-current of the transistor, n is the total number of the design parameters that are related to the threshold voltage adder of the transistor, σ I — off — 0 2 is a scaled variance of the off-current a nominal transistor that is scaled to match the size of the transistor on which the off-current distribution is calculated, and wherein Δ(σ I — off — i 2 ) is a contribution of the i-th design parameter to the change of the variance of the off-current of the transistor. Since σ I — off 2 −σ I — off — 0 2 may be positive or negative, the change in the off-current deviation may be positive or negative. In other words, the incremental off-current deviation, which measures changes in the standard deviation due to the collective set of the design parameters of the transistor, may be an increment or decrement. The design parameters include inherent and external design parameters of the transistor. Calculation of the incremental on-current deviation for the subset and the incremental off-current deviation for the subset employs incremental on-current deviation calculation means and incremental off-current deviation calculation means, respectively. Incremental on-current deviation calculation means and/or incremental off-current deviation calculation means may be a stand-alone program that is dedicated to calculation of the incremental on-current deviation and the incremental off-current deviation, and may reside in a computer. Alternately, the incremental on-current deviation calculation means and/or the incremental off-current deviation calculation means may be integrated into a system, which may include other automated programs, for designing a semiconductor chip or for diagnosing parametric yield of semiconductor chips. The incremental on-current deviation is an increment in statistical deviation of on-current of the subset of the semiconductor chip design from a scaling-estimated statistical deviation of on-current due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of at least one device of the subset. The scaling-estimated statistical deviation of on-current is obtained by scaling of statistical deviation of on-current of at least one nominal device. The incremental off-current deviation is an increment in statistical deviation of off-current of the subset of the semiconductor chip design from a scaling-estimated statistical deviation of off-current due to the design parameters of the subset other than inherent geometric dimensions and inherent characteristics of devices in the subset. The scaling-estimated statistical deviation of off-current is also obtained by scaling of statistical deviation of off-current of at least one nominal device. The parametric yield estimation value is based on at least one of the incremental on-current deviation of the subset and the incremental off-current deviation of the subset. The incremental on-current deviation may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Likewise, the incremental off-current deviation may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Further, on-current distribution calculation means may be employed to combine a first data set for the average on-current adder of the subset and a second data set for the incremental on-current deviation of the subset, and to calculate statistical distribution of on-current within the subset. Likewise, off-current distribution calculation means may be employed to combine a third data set for the average off-current adder of the subset and a fourth data set for the incremental off-current deviation of the subset, and to calculate statistical distribution of on-current within the subset. Each of the statistical distribution of on-current within the subset and the statistical distribution of off-current of the subset contains data for at least two devices within the subset. Calculation of the statistical distribution of on-current and/or the statistical distribution of off-current of the subset may be performed device by device for each device in the subset, or alternatively, may be performed by grouping each of the first through fourth data set into sub-groups containing data for at least two devices within each. The on-current distribution calculation means and/or the off-current distribution calculation means may be a stand-alone program that is dedicated to calculation of the statistical distribution of on-current within the subset and the statistical distribution of off-current within the subset, and may reside in a computer. Alternately, the on-current distribution calculation means and/or the off-current distribution calculation means may be integrated into a system, which may include other automated programs, for designing a semiconductor chip or for diagnosing parametric yield of semiconductor chips. The statistical distribution of on-current is statistical distribution of on-current of the entirety of devices in the subset. The statistical distribution of off-current is statistical distribution of off-current of the entirety of devices in the subset. A plurality of subsets that collectively comprise the entirety of the semiconductor chip design may be employed to generate a first set of statistical distribution of on-current of subsets of the semiconductor chip design and a second set of statistical distribution of off-current of the subsets of the semiconductor chip design. The plurality of subsets may be selected such that each of the plurality of subsets is disjoined from one another and has a unit area and the plurality of subsets collectively constitute the entirety of the semiconductor chip design. In this case, the first set of statistical distribution of on-current of subsets of the semiconductor chip design is an areal on-current density and a second set of statistical distribution of off-current of the subsets of the semiconductor chip is an areal off-current density. Statistical quantities such as a mathematical average, deviations, various quantiles, maximum, and minimum may be derived from each of the statistical distribution of on-current of the subset and the statistical distribution of off-current of the subset. In this case, the parametric yield estimation value is based on at least one of the statistical distribution of on-current of the subset and the statistical distribution of off-current of the subset. The statistical distribution of on-current of the subset may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design Likewise, the statistical distribution of off-current of the subset may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Yet further, on-state temperature distribution calculation means may be employed to calculate on-state temperature distribution of a semiconductor chip that is manufactured with the semiconductor chip design. Likewise, off-state temperature distribution calculation means may be employed to calculate off-state temperature distribution of a semiconductor chip that is manufactured with the semiconductor chip design. The calculated on-state temperature distribution may be directly based on the areal on-current density, which is the first set of statistical distribution of on-current of subsets of the semiconductor chip design described above. The calculated off-state temperature distribution may be directly based on the areal off-current density, which is the second set of statistical distribution of off-current of subsets of the semiconductor chip design described above. Alternately, the on-state temperature distribution of the semiconductor chip and/or the off-state temperature distribution of the semiconductor chip may be an ab initio calculation based on calculated threshold voltage adder, an average on-current adder, and/or an average off-current adder for each device in the semiconductor chip design. The on-state temperature distribution calculation means and/or the off-state temperature distribution calculation means may be a stand-alone program that is dedicated to calculation of the on-state temperature distribution within the subset and the off-state temperature distribution within the subset, and may reside in a computer. Alternately, the on-state temperature distribution calculation means and/or the off-state temperature distribution calculation means may be integrated into a system, which may include other automated programs, for designing a semiconductor chip or for diagnosing parametric yield of semiconductor chips. The calculation of the on-state temperature distribution of the semiconductor chip design and/or the on-state temperature distribution may be performed on a subset of a semiconductor chip design that is less than the entirety of the semiconductor chip design, or may be performed on the entirety of the subset of the semiconductor chip design, i.e., the subset is equal to the entirety of the semiconductor chip design. In case the calculation is performed on the entirety of the semiconductor chip design, a plurality of subsets that collectively comprise the entirety of the semiconductor chip design may be employed to calculate the on-state temperature distribution of the semiconductor chip design and/or the on-state temperature distribution of the semiconductor chip design. The plurality of subsets may be selected such that each of the plurality of subsets is disjoined from one another and has a unit area and the plurality of subsets collectively constitute the entirety of the semiconductor chip design. The on-state temperature distribution of the semiconductor chip design and the off-state temperature distribution of the semiconductor chip design may be nominal temperature distributions, i.e., average temperature distributions. In other words, the on-state temperature distribution is a statistical average of an ensemble of on-state temperature distributions. The statistical average may be a statistical mean, statistical median, or statistical mode. Statistical variations in the on-state temperature distribution and/or in the off-state temperature distribution may also be generated by employing statistical quantities of the statistical distribution of on-current of the subsets and/or the statistical quantities of the statistical distribution of the off-current of the subsets. The statistical quantities may include deviations, various quantiles, maximum, and minimum of each of the statistical distributions. Statistical quantile temperature distributions may thus be generated from the statistical distribution of on-current of the subsets and/or the statistical quantities of the statistical distribution of the off-current of the subsets. For example, 0.1% quantile on-temperature distribution represents the on-temperature distribution that only 0.1% of an ensemble of measured temperature distribution generated from a randomly selected manufactured semiconductor chips is expected to exceed in temperature. In this case, the parametric yield estimation value may be based on the statistical average of, and/or statistical variations in, the on-state temperature distribution and/or the off-state temperature distribution. The parametric yield estimation value may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Referring to FIG. 5 , an exemplary method for designing a semiconductor chip according an aspect of the present invention is shown in a flow chart 500 . Referring to step 510 , functional requirements of a chip are defined as in step 210 in the flow chart 200 in FIG. 2 . Referring to step 520 , an electronic system level (ESL) description is generated based on the functional requirements of the chip as in step 220 in the flow chart 200 . Referring to step 530 , a register transfer level (RTL) description is generated from the electronic system level (ESL) description in the next chip design phase as in the step 230 in the flow chart 200 . Referring to step 540 , logic synthesis is performed to convert the RTL description in the form of the hardware description language (HDL) into a gate level description of the chip by a logic synthesis tool as in the step 240 in the flow chart 200 . Referring to step 545 , parametric value estimation means described above is employed to estimate a parametric yield estimation value for each of at least one subset of the semiconductor chip design in the form of the hardware description language. The parametric yield estimation value may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Each of the parametric yield estimation value, which is referred to as “estimated PY” in the flow chart 500 , is compared with a corresponding parametric yield target value for the parametric yield of the corresponding subset. If any one of the parametric yield estimation value(s) is/are less than the corresponding parametric yield target value for the parametric yield of the corresponding subset, logic synthesis of the step 540 is re-done for the subset to increase the parametric yield estimation value by improving the semiconductor chip design in the form of the hardware description language. This process may be repeated until each of the at least one subset of the semiconductor chip design generates parametric yield estimation value exceeds the corresponding parametric yield target value. If all of the parametric yield value(s) exceed(s) the corresponding parametric yield target in the step 545 , placement and routing tools utilize the results of the logic synthesis to create a physical layout for the chip in the step 550 as in the step 250 in the flow chart 200 . Referring to step 555 , parametric value estimation means described above is employed to estimate a parametric yield estimation value for each of at least one subset of the semiconductor chip design in the form of the physical layout. The parametric yield estimation value may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Each of the parametric yield estimation value, which is referred to as “estimated PY” in the flow chart 500 , is compared with a corresponding parametric yield target value for the parametric yield of the corresponding subset. If any one of the parametric yield estimation value(s) is/are less than the corresponding parametric yield target value for the parametric yield of the corresponding subset, placement and routing in the step 550 is re-done for the subset to increase the parametric yield estimation value by improving the semiconductor chip design in the form of the physical layout. This process may be repeated until each of the at least one subset of the semiconductor chip design generates parametric yield estimation value exceeds the corresponding parametric yield target value. If all of the parametric yield value(s) exceed(s) the corresponding parametric yield target in the step 555 , power analysis and timing analysis is performed in the step 560 as in the step 260 in the flow chart 200 . Referring to step 570 , the chip design is analyzed to extract design specification as in the step 270 in the flow chart 200 . According to the present invention, the semiconductor chip design is checked for expected parametric yield level of at least one subset of the semiconductor chip design by estimating a parametric yield estimation value for each of the at least one subset. As noted above, the parametric yield estimation value may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. The collection of the at least one subset may constitute the entirety of the semiconductor chip design. Since the inventive semiconductor chip design system can check expected parametric yield level of the semiconductor chip design and provides modification of the semiconductor chip design, designers may have reasonable confidence that the parametric yield of manufactured semiconductor chips according to the semiconductor chip design would be at an expected level in a design phase of semiconductor chip manufacturing. Referring to FIG. 6 , an exemplary semiconductor chip manufacturing sequence including the steps of chip design according to another aspect of the present invention is shown in a flow chart 600 . Referring to step 610 , a semiconductor chip design is provided as described in steps 510 - 560 of the flow chart 500 in FIG. 5 . Referring to step 612 , design specification is generated for the chip as in the step 570 of the flow chart 500 in FIG. 5 . Referring to step 620 , data preparation is performed on the chip design to generate various mask levels as in the step 320 of the flow chart 300 in FIG. 3 . Referring to step 630 , semiconductor chips are manufactured in a semiconductor chip fabrication facility employing various semiconductor processing steps including lithography, deposition, and etching. Referring to step 640 , the manufactured semiconductor chips are tested and characterized for functionality. Dysfunctional chips are sorted out. Operating frequency, on-state leakage, and off-state leakage are measured on functional chips. Referring to step 650 , parametric yield, i.e., chip limited yield (CLY), is calculated for the group of semiconductor chips that do not suffer from random defect yield loss or process limited yield loss based on the results of the testing and characterization. Assuming a normal scenario in which the random defect yield loss and the process limited yield loss of the manufacturing process are within expected ranges, delivery of sufficient number of chips to a customer depends on the parametric yield loss. If the parametric yield exceeds a minimum parametric yield target value, sufficient number of chips meeting the design specification may be shipped to a customer, as shown in the step 660 . If the parametric yield is below a minimum target value, analysis on the parametric yield of the semiconductor chip design is performed. Referring to step 670 , methods described above may be employed to calculate a parametric yield estimation value for a subset of the semiconductor chip design. As noted above, the parametric yield estimation value may be calculated for each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. Consequently, comparison of a measured parametric yield value and a corresponding parametric yield estimation value may be performed each device type, for each region of the semiconductor chip design, for each functional block, and/or for the entirety of the semiconductor chip design. For any given subset of the semiconductor chip design, the measured parametric yield value of the semiconductor chip is compared with the corresponding parametric yield estimation value. The comparison of the measured parametric yield value and the corresponding parametric yield estimation value may be performed manually, or preferably, may be performed by parametric yield comparison means, which may be a program dedicated to comparison of the two parameters, or may be a program incorporated into a test program or a characterization program. Referring to step 685 , in case the measured parametric yield value and the corresponding parametric yield estimation value match, which would imply that the original semiconductor chip design was designed to achieve the parametric yield of the measured parametric yield value, methods of enhancing parametric yield on future semiconductor chips may be explored. It is noted that employing a system or methods of estimating at least one parametric yield estimation value as describe abode according to the present invention can prevent this scenario by modifying the semiconductor chip design in the design phase. A process model is utilized to determine if process parameters, such as a dimension or composition of a physical component of a semiconductor chip, may be modified to increase the parametric yield of semiconductor chips in manufacturing or to be manufactured in the future to the minimum target value for the parametric yield. The process model is a set of assumptions or a program based on the set of assumptions for correlating process parameters of semiconductor processing steps employed during manufacturing of the semiconductor chips with measured parametric yield value. Referring to step 690 , in case the modification of some process parameters is deemed to be capable of increasing the parametric yield of semiconductor chips to be subsequently manufactured above the minimum target value of the parametric yield, the process parameters are modified. The step 60 is repeated to manufacture more semiconductor chips with the modified process parameters. The parametric yield of a new batch of semiconductor chips is expected to be above the minimum target value upon execution of a second iteration of the step 640 for test and characterization of the semiconductor chips and the step 650 for comparison of measured parametric yield value and the minimum target value for the parametric yield. Referring to step 692 , in case the modification of process parameters is deemed incapable of increasing the parametric yield of semiconductor chips to be subsequently manufactured above the minimum target value of the parametric yield, at least one design element to modify is identified and modification to the original semiconductor chip design is performed. The semiconductor chip design is modified employing the step 610 again and subsequent steps described above are repeated. In this case, the set of at least one parametric yield estimation value for a subset of the semiconductor chip design may be advantageously employed to identify the at least one design element to be modified. The at least one design element to be modified may be at least one device type, at least one region of the semiconductor chip design, and/or at least one functional block of the semiconductor chip design to be modified. In case the measured parametric yield value and the corresponding parametric yield estimation value does not match at the step 670 , which would imply that the process model is not accurate or there is an anomaly in the parametric yield caused by a yet undetected error in the semiconductor chip design or in the manufacturing process employed to manufacture the tested semiconductor chips, the cause of the mismatch is investigated. Referring to step 675 , it is determined whether the mismatch between the measured parametric yield value and the corresponding parametric yield estimation value may be resolved by modifications to the process model. Process model fitting means may be employed to attempt resolving the discrepancy between the parametric model estimation value and the measured parametric yield value by altering process model parameters, i.e., parameters in the process model. To effect a resolution of the discrepancy if possible, a measured process parameter database that stores measured process parameter values that are measured during manufacturing of the semiconductor chips may be employed. The process model fitting means alters the process model parameters and measures the effectiveness of the process model for each setting of the process model parameters as variations in the measured process parameter values are correlated with the measured parametric yield value by the process model. The effectiveness of the process model may be measured, for example, by goodness of fit, correlation coefficients, or by another measure of degree of success in statistical fitting. Thus, the process model fitting means is employed to improve accuracy of the process model employing the measured process parameter values in the measured process parameter database. The process model fitting means may be a dedicated program for fitting, or resolving, the discrepancy between the parametric yield estimation value and the measured parametric yield value. Alternatively, the process model fitting means may be incorporated in a yield analysis program incorporating other programs. In case the measured parametric yield value and the corresponding parametric yield estimation value may be matched by reasonable and verifiable changes in the process model parameters in the process model, the process model is modified with the best-fitting process model parameters at step 680 . Subsequently, the step 685 is performed to explore methods of enhancing parametric yield on future semiconductor chips. The process flow thereafter is the same as described above. Referring to step 677 , in case the measured parametric yield value and the corresponding parametric yield estimation value may not be matched by reasonable and verifiable changes in the process model parameters in the process model, the likelihood of an anomaly in the parametric yield caused by a yet undetected error in the semiconductor chip design or in the manufacturing process employed to manufacture the tested semiconductor chips is deemed to be sufficiently high. Consequently, methods to investigate the anomaly in the parametric yield are employed at this point. Once the anomaly is identified, the step 670 may be repeated by comparing a newly estimated parametric yield estimation value based on findings on the anomaly with the measured parametric yield value. Alternatively, the step 692 may be performed to identify at least one design element to modify, and modification to the original semiconductor chip design may be performed as described above. The present invention provides a semiconductor chip manufacturing facility a system and methods for investigation of the source of the depressed parametric yield. The inventive system and methods may be employed upon discovery of depressed parametric yield that does not meet a target, or may be preemptively employed concurrently with or prior to production of semiconductor chips. Further, systematic methods are provided for handling a parametric yield that does not meet a target value. Referring to FIG. 7 , an exemplary sequence for identifying a location of anomalous functionality of a semiconductor chip according to yet another aspect of the present invention is shown in a flow chart 700 . The location of anomalous functionality may be the location of the anomaly in the parametric yield at the step 677 described above. Referring to step 710 , a semiconductor chip design is provided as described in steps 510 - 560 of the flow chart 500 in FIG. 5 . Referring to step 725 , on-current distribution calculation means may be employed to calculate spatial distribution of on-current within the semiconductor chip. Alternately or in parallel, off-current distribution means may be employed to calculate spatial distribution of off-current within the semiconductor chip. The spatial distribution of on-current and the spatial distribution of off-current within the semiconductor chip are collectively referred to as “current maps” of the semiconductor chip. The spatial distribution of on-current is a map of the density of on-current in the semiconductor chip. The spatial distribution of off-current is a map of the density of off-current in the semiconductor chip. The on-current distribution calculation means and the off-current distribution calculation means are as described above. Current-to-temperature conversion means are employed to convert at least one of the spatial distribution of on-current and the spatial distribution of off-current into an estimated spatial temperature distribution map, which is herein referred to as a “thermal map.” Current-to-temperature conversion means may be a stand-alone program that is dedicated to calculation of a temperature distribution map of the semiconductor chip, and may reside in a computer. Alternately, the current-to-temperature conversion means may be integrated into a system, which may include other automated programs, for designing a semiconductor chip or for diagnosing parametric yield of semiconductor chips. Referring to step 730 , semiconductor chips are manufactured in a semiconductor chip fabrication facility employing various semiconductor processing steps including lithography, deposition, and etching. Referring to step 735 , a measured temperature distribution map is generated by measuring at least one of manufactured semiconductor chips in an on-state or in an off-state. Referring to step 750 , the estimated spatial temperature distribution map and the measured temperature distribution map are compared to determine whether the two maps match. Referring to step 760 , in case the two maps match, the semiconductor chip design is deemed to be free of any apparent design error as determined by the inventive system and methods. Referring to step 775 , in case the two maps do not match, it is determined whether the mismatch between the two maps may be resolved by modifications to the process model. Process model fitting means may be employed to attempt resolving the discrepancy between the two maps by altering process model parameters, i.e., parameters in the process model as described above. The process model fitting means is the same as described above. The process model fitting means is employed to improve accuracy of the process model employing the measured process parameter values in the measured process parameter database. In this case, however, the process model fitting means may be a dedicated program resolving the discrepancy between the estimated spatial temperature distribution map and the measured temperature distribution map instead of resolving a discrepancy between a parametric yield estimation value and a measured parametric yield value. Alternatively, the process model fitting means may be incorporated in a characterization program that may also incorporate other programs. In case the two maps may be matched by reasonable and verifiable changes in the process model parameters in the process model, the process model is modified with the best-fitting process model parameters at step 780 . Since the two maps match after modification of the process model parameters, the semiconductor chip design is deemed to be free of any apparent design error as determined by the inventive system and methods as in the step 760 . Referring to step 777 , in case the two maps may not be matched by reasonable and verifiable changes in the process model parameters in the process model, mismatched spots are identified. It is noted herein that identification of the mismatched spots may be a methods to investigate the anomaly in the parametric yield described above. Referring to step 792 , at least one design element to modify is identified based on the location of the mismatched spots. The semiconductor chip design is modified employing the step 710 again and subsequent steps described above are repeated. In this case, the identification of the physical location of the mismatched spots is advantageously employed to identify the at least one design element to be modified. The at least one design element to be modified may be at least one device type, at least one region of the semiconductor chip design, and/or at least one functional block of the semiconductor chip design to be modified. Referring to FIG. 8 , an exemplary estimated spatial temperature distribution map for a semiconductor chip design obtained by the inventive method is shown, in which low temperature regions are shown in black and high temperature regions are shown in white. Referring to FIG. 9 , an exemplary measured temperature distribution map for a semiconductor chip manufactured using the semiconductor chip design of FIG. 8 is shown, in which low temperature regions are shown in black and high temperature regions are shown in white. Anomalous mismatches are found in some areas, which are mismatched spots. One of the mismatched spots is labeled with “MS.” The comparison of an estimated spatial temperature distribution map and a measured temperature distribution map may be performed manually, or preferably, by an automated system employing temperature distribution comparison means. The temperature distribution comparison means may be a program that receives the estimated spatial temperature distribution map and the measured temperature distribution map as input data and performs image processing to produce coordinates of mismatched spots. The inventive method provides a system and methods for identifying a location of anomalous functionality to facilitate debugging of a semiconductor chip design. While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention and the following claims.

Impact on parametric performance of physical design choices for transistors is scored for on-current and off-current of the transistors. The impact of the design parameters are incorporated into parameters that measure predicted shift in mean on-current and mean off-current and parameters that measure predicted increase in deviations in the distribution of on-current and the off-current. Statistics may be taken at a cell level, a block level, or a chip level to optimize a chip design in a design phase, or to predict changes in parametric yield during manufacturing or after a depressed parametric yield is observed. Further, parametric yield and current level may be predicted region by region and compared with observed thermal emission to pinpoint any anomaly region in a chip to facilitate detection and correction in any mistakes in chip design.

RELATED APPLICATION [0001] This application is a national stage application under 35 USC §371 of PCT Patent Application No. PCT/US2010/054165, filed Oct. 26, 2010, which claims the benefit of U.S. Provisional Application No. 61/255,045, filed Oct. 26, 2009, and U.S. Provisional Application No. 61/382,850, filed Sep. 14, 2010. TECHNICAL FIELD [0002] This invention relates to a bariatric device for weight loss, and ancillary items such as sizing, and monitoring. BACKGROUND [0003] Obesity has been steadily increasing worldwide and poses serious health risks, which if untreated, can become life threatening. There are various methods for reducing weight such as diet, exercise, and medications but often the weight loss is not sustained. Significant advances have been made in the surgical treatment of obesity. Surgical procedures such as the gastric bypass and gastric banding have produced substantial and lasting weight loss for obese patients. These procedures and products have been shown to significantly reduce health risks over time, and are currently the gold standard for bariatric treatment. [0004] Although surgical intervention has been shown to be successful at managing weight loss, both procedures are invasive and carry the risks of surgery. Gastric bypass is a highly invasive procedure which creates a small pouch by segmenting and/or removing a large portion of the stomach and rerouting the intestines permanently. Gastric bypass and its variations have known complications. Gastric banding is an invasive procedure which creates a small pouch in the upper stomach by wrapping a band around the stomach to segment it from the lower stomach. Although the procedure is reversible, it also carries known complications. [0005] Less invasive or non-invasive devices that are removable and capable of significant weight loss are desirable. A device that has demonstrated less invasive approach is defined in U.S. patent application Ser. No. 11/463,192 and PCT/US2008/053912, and shows a three element or single element device that is sutured through the esophagus and cardia or the cardia. The inventions included herein demonstrate improvements of this device such as improved means of adjustability, use of sensors for monitoring physical parameters, use of sensors to controls adjustments, remote adjustments with sensor data, data storage for data collected through the sensors, improvements in fixation, shape and form, and improvements in contact area. [0006] This application also includes new inventions for bariatric devices that apply force to the upper stomach which are placed with fixation or devices which could be placed without fixation in the pouch of a gastric band or by pass patient. SUMMARY [0007] The bariatric device described herein induces weight loss by engaging the upper stomach which could include the cardia, the adjacent fundus, the abdominal portion of the esophagus or the gastroesophogeal junction. One embodiment of the bariatric device disclosed herein is based on applying force or pressure on or around the gastroesophogeal (GE) junction and upper stomach. It may also include pressure in the lower esophagus. The device can be straightened or compressed to allow for introduction down the esophagus and then change into the desired shape inside the stomach. This device is then secured with sutures or other fixation to maintain the pressure against the upper stomach. The device may be constructed of a single main element with fixation and adjustability: [0008] 1) A cardiac element that contacts or intermittently contacts the upper stomach [0009] a. Fixation to hold the device position and location [0010] b. Adjustment means [0011] One of the purposes of the cardiac element which contacts the upper stomach or cardia is to at least intermittently apply direct force or pressure to this region of the stomach. Applying force or pressure to this region of the stomach replicates the forces and pressures that are generated during eating and swallowing. It also engages or stimulates the stretch receptors that are present in this region of the stomach. During eating, as the stomach fills, peristalsis starts and generates higher pressures in the stomach for digestion, which activates the stretch receptors to induce a satiety response, and may also trigger a neurohormonal response to cause satiety or weight loss. The cardiac element replicates this type of pressure on the stretch receptors. The cardiac element could take the form of many different shapes but a preferred shape is the frusto-cone. This element could take the form of many different shapes such as a ring, a disk, a cone, a frusto-cone, a portion of a cone, portion of frusto-cone, a sphere, an oval, an ovoid, a tear drop, a pyramid, a square, a rectangle, a trapezoid, a wireform, a spiral, a protuberance, multiple protuberances, multiple spheres or multiples of any shape or other suitable shapes. It could also be an inflatable balloon or contain an inflatable balloon. For the purpose of the claims of this patent, the “upper stomach” includes the cardiac region (a band of tissue in the stomach that surrounds the gastroesophogeal (GE) junction), and the fundus adjacent to the cardiac region, and may be either of these two areas, or both. [0012] With the single cardiac member, a means of fixation will be required to hold the device in place. This could be accomplished by sutures, barbs, tacks, clips, t-connectors or others. The device could also be placed without fixation where the device may be held in place by restriction caused by a gastric band, gastric bypass, sleeve gastrectomy or other previous bariatric procedure. Where fixation is used, it could be permanently integrated into the cardiac element or it could be a separate piece that is modular to add at the time of placement. To make the device customized for each patient, a means for adjusting the amount of pressure that is placed on the cardia can be incorporated into the device. [0013] In another embodiment of the bariatric device disclosed herein, the device may be constructed of three main elements with fixation and adjustability: [0014] 1) A cardiac element that contacts or intermittently contacts the upper stomach [0015] 2) An esophageal element located in the abdominal portion of the esophagus. [0016] 3) A connecting element to connect the first 2 elements [0017] a. Fixation to hold the device position and location [0018] b. Adjustment means [0019] One of the purposes of the cardiac element which contacts the upper stomach or cardiac region would be to apply at least intermittent pressure or force to engage a satiety response and/or cause a neurohormonal response to cause a reduction in weight. This element could take the form of many different shapes but the preferred shape is a frusto-cone. This element could take the form of many different shapes such as a ring, a disk, a cone, frusto-cone, a portion of a cone, portion of frusto-cone, a sphere, an oval, an ovoid, a tear drop, a pyramid, a square, a rectangle, a trapezoid, a wireform, a spiral, a protuberance, multiple protuberances, multiple spheres or multiples of any shape or other suitable shapes. It could also be an inflatable balloon or contain an inflatable balloon. This balloon could be spherical, or it could be a torus or a sphere with channels on the side to allow food to pass, or it could be a cone, a portion of a cone or other shapes. The cardiac element may be in constant or intermittent contact with the upper stomach based on the device moving in the stomach during peristalsis. [0020] The purpose of the esophageal element is to also engage stretch receptors located at the lower esophagus to stimulate satiety and could also provide a means for fixation into the esophagus. Alternatively, the purpose of the esophageal element may be only to fix the device in the esophagus and/or serve as a lever for the cardiac element. [0021] The purposes of the connecting element are to connect the cardiac and esophageal elements, to provide structure for the device to maintain its relative placement location, and to provide tension, pressure, or an outwardly biasing force on the cardiac element. [0022] A means of fixation will be required to hold the device in place. This could be accomplished by sutures, barbs, tacks, clips, T-bars or others. The fixation could be permanently integrated into the cardiac element or it could be a separate piece that is modular to add at the time of placement. [0023] The purpose of the adjustability of the device is to ensure that the proper amount of pressure is applied to each patient. The adjustability allows the pressure to be customized for each patient to optimize the response. If the pressure is too great, the patient may experience discomfort, nausea or a total disinterest in food. Conversely, if the pressure is too low, the patient may continue to overeat and the effectiveness of the device may be reduced. By allowing the physician to adjust the device after placement, the treatment can be customized. Similarly, patients may experience satiety in the beginning, but it may wane over time. These patients may require an adjustment to increase the satiety signal overtime, and the adjustability feature provides the device this flexibility. The adjustability could be achieved in a variety of forms. For example, it may be desirable to change the distance between the esophageal and cardiac elements to change the overall length of the device to increase compression of the cardia. For example, it may be desirable to change the distance between the esophageal and cardiac elements to change the overall length of the device to increase compression of the cardia. This could be accomplished by changing the length of the connecting element or the fixation element. It may also be desirable to change the shape of the device, such as to increase the diameter or angle of the device. The change may be to just a small area of the device. It may also be desirable to increase or decrease the stiffness of the device to increase resistance of the device against the tissue. This change may also be to just a small area of the device to gain a specific response. [0024] The cardiac, esophageal and connecting elements could also be self-expanding or incorporate a portion that is self expanding. Self expansion would allow the element or a portion of the element to be compressible, but also allow it to expand back into its original shape to maintain its function and position within the stomach, as well as the function and position of the other element(s). Self expansion would allow the elements to compress for placement down the esophagus, and then expand to its original shape in the stomach. This may also allow the element to accommodate peristalsis once the device is in the stomach. [0025] In any of the embodiments disclosed herein, the device may be straightened or collapsed for insertion down the esophagus, and then reformed to the desired shape in the stomach to apply pressure at the upper and lower stomach regions or other regions as described above. At least a portion of the device could be made of a shape memory alloys such as Nitinol (nickel titanium), low density polyethylene or polymers to allow for it to compress or flex and then rebound into shape in the stomach. For placement of the device into the stomach, a flexible polymer tube, such as a large diameter overtube or orogastric tube, could be placed down the esophagus to protect the esophagus and stomach. The device could then be straightened and placed into the tube for delivery into the stomach, and then regain its proper shape in the stomach once it exits the tube. Another variation for placement would be a custom delivery catheter to compress the device during placement and then allow the device to deploy out of the catheter once in the stomach. [0026] The bariatric device could be made of many different materials. Elements of the device could be made with materials with spring properties that have adequate strength to hold their shape after reforming, and/or impart an outwardly biasing force. The materials would also need to be acid resistant to withstand the acidic environment of the stomach. Elements of the device could be made of Nitinol, shape memory plastics, shape memory gels, stainless steel, superalloys, titanium, silicone, elastomers, teflons, polyurethanes, polynorborenes, styrene butadiene co-polymers, cross-linked polyethylenes, cross-linked polycyclooctenes, polyethers, polyacrylates, polyamides, polysiloxanes, polyether amides, polyether esters, and urethane-butadiene co-polymers, other polymers, or combinations of the above, or other suitable materials. For good distribution of stress to the stomach wall or to reduce contact friction, the device could be coated with another material or could be placed into a sleeve of acid resistant materials such as teflons, PTFE, ePTFE, FEP, silicone, elastomers or other polymers. This would allow for a small wire to be encased in a thicker sleeve of acid resistant materials to allow for a better distribution of force across a larger surface area. The device could take many forms after it reshapes. BRIEF DESCRIPTION OF DRAWINGS [0027] FIG. 1 depicts a side view of an embodiment of a bariatric device located within a cross-section of a stomach. [0028] FIG. 2A depicts a front view of an adjustment mechanism for an embodiment of the present invention. [0029] FIG. 2B depicts a side view of an adjustment mechanism for an embodiment of the present invention. [0030] FIG. 2C depicts a front view of an adjustment mechanism for an embodiment of the present invention. [0031] FIG. 2D depicts a side view of an adjustment mechanism for an embodiment of the present invention. [0032] FIG. 3A depicts a top view of an embodiment of the bariatric device of the present invention. [0033] FIG. 3B depicts a side view of an embodiment of the bariatric device of the present invention. [0034] FIG. 3C depicts a side view of an embodiment of a bariatric device of the present invention located within a cross-section of a stomach. [0035] FIG. 4A depicts a side view of an embodiment of a bariatric device of the present invention located within a cross-section of a stomach with a modular adjustment mechanism. [0036] FIG. 4B depicts a top view of an embodiment of the bariatric device of the present invention with 2 modular adjustment mechanisms. [0037] FIG. 4C depicts a top view of an embodiment of the bariatric device of the present invention with 1 modular adjustment mechanism. [0038] FIG. 4D depicts a front perspective view of a modular adjustment mechanism from FIG. 4A . [0039] FIG. 4E depicts a front perspective view of a modular adjustment mechanism from FIG. 4A . [0040] FIG. 5A depicts a side view of an embodiment of the bariatric device of the present invention with an adjustment mechanism located within a cross-section of a stomach. [0041] FIG. 5B depicts a top view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0042] FIG. 5C depicts a top view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0043] FIG. 6A depicts a side of an embodiment of a bariatric device of the present invention with an adjustment mechanism and a retractable leash located within a cross-section of a stomach. [0044] FIG. 6B depicts a top view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0045] FIG. 6C depicts a top view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0046] FIG. 7A depicts a side view of a T-bar in the undeployed state. [0047] FIG. 7B depicts a side view of a T-bar in the deployed state. [0048] FIG. 7C depicts a side view of a fixation element in the undeployed state. [0049] FIG. 7D depicts a side view of a fixation element in the deployed state. [0050] FIG. 8A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism located within a cross-section of a stomach. [0051] FIG. 8B depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism located within a cross-section of a stomach. [0052] FIG. 8C depict a close up side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the adjusted state. [0053] FIG. 8D depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism located within a cross-section of a stomach. [0054] FIG. 8E depicts a perspective view of an embodiment of the bariatric device of the present invention. [0055] FIG. 9A depicts a side view of the embodiment of a bariatric device of the present invention with an adjustment mechanism. [0056] FIG. 9B depicts a close up of the adjustment mechanism of 9 A. [0057] FIG. 9C depicts a side view of the embodiment of a bariatric device of the present invention with an adjustment mechanism. [0058] FIG. 9D depicts a close up of the adjustment mechanism of 9 A. [0059] FIG. 10A depicts a remote controller of an embodiment of the present invention, worn next to the user's body. [0060] FIG. 10B depicts a remote controller of an embodiment of the present invention, used without wearing or placing adjacent to the body. [0061] FIG. 11A depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0062] FIG. 11B depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0063] FIG. 12 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0064] FIG. 13A depicts a side view of a fixation element. [0065] FIG. 13B depicts a side view of a fixation element in the undeployed state. [0066] FIG. 13C depicts a side view of a fixation element in the deployed state. [0067] FIG. 13D depicts a side view of a fixation element in the deployed state. [0068] FIG. 13E depicts a side view of a fixation element in the undeployed state. [0069] FIG. 13F depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0070] FIG. 13G depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0071] FIG. 14A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0072] FIG. 14B depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0073] FIG. 14C depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0074] FIG. 15A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0075] FIG. 15B depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0076] FIG. 15C depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism. [0077] FIG. 16A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism, located within a cross-section of a stomach [0078] FIG. 16B depicts a variation of the adjustment mechanism in FIG. 16A . [0079] FIG. 16C depicts a variation of the adjustment mechanism in FIG. 16A . [0080] FIG. 16D depicts a variation of the adjustment mechanism in FIG. 16A . [0081] FIG. 17A depicts a side view of an embodiment of the bariatric device of the present invention, located within a cross-section of a stomach [0082] FIG. 17B depicts a side view of an embodiment of a bariatric device of the present invention in the undeployed state. [0083] FIG. 17C depicts a side view of an embodiment of a bariatric device of the present invention in the deployed state. [0084] FIG. 17D depicts a side view of an embodiment of a bariatric device of the present invention in the deployed state. [0085] FIG. 18A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism, located within a cross-section of a stomach. [0086] FIG. 18B depicts a top view of an embodiment of a bariatric device of the present invention with an adjustment mechanism, located within a cross-section of a stomach [0087] FIG. 18C depicts a side view of an embodiment a bariatric device of the present invention with an adjustment mechanism in the deflated state. [0088] FIG. 18D depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the inflated state. [0089] FIG. 18E depicts a front view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the deflated state. [0090] FIG. 18F depicts a front view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the inflated state. [0091] FIG. 19 depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism, located within a cross-section of a stomach. [0092] FIG. 20 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0093] FIG. 21A depicts a backside perspective view of an embodiment of the bariatric device of FIG. 20 . [0094] FIG. 21B depicts a front view of an embodiment of the bariatric device of FIG. 20 . [0095] FIG. 22 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0096] FIG. 23A depicts a backside perspective view of an embodiment of the bariatric device of FIG. 22 . [0097] FIG. 23B depicts a front view of an embodiment of the bariatric device of FIG. 22 . [0098] FIG. 24A depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the unexpanded state. [0099] FIG. 24B depicts a side view of an embodiment of a bariatric device of the present invention with an adjustment mechanism in the expanded state. [0100] FIG. 25 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0101] FIG. 26 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. [0102] FIG. 27 depicts a side view of an embodiment of a bariatric device of the present invention, located within a cross-section of a stomach. DETAILED DESCRIPTION OF THE INVENTION [0103] The detailed description set forth below in connection with the appended drawings is intended as a description of presently-preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. [0104] The most basic embodiment of the 3 element bariatric device 10 is shown in FIG. 1 , where the device consists of an esophageal element 36 , cardiac element 12 , and a connecting element 25 between the esophageal and cardiac elements. In this embodiment, the esophageal and cardiac elements 36 , 12 are separate structures, and do not form a contiguous surface, but instead are connected by the third separate structure, the connecting element 25 . Such a non-contiguous structure may be referred to in the claims as “dis-contiguous.” This device may require fixation to the stomach and/or esophagus to hold it in place to allow it to induce a satiety response and to prevent it from migrating. The fixation element 31 shown in FIG. 1 comprises a fixation connector 71 (which may be a suture or other suitable connector), coupled with the esophageal element 36 by a first anchor 70 , and coupled with the cardiac element 12 by a second anchor 72 . As will be discussed below, a fixation element 31 may comprise many variations and combinations of anchors and/or fixation connectors. This embodiment delivers direct force to at least one of the following 1) the abdominal portion of the esophagus 2) the esophageal-gastric junction, and 3) the proximal cardiac portion of the stomach; and the force delivered is adjustable through a variety of means to match the individual needs of the patient. To improve the ease of adjustment and the accuracy of the adjustment, the device could be adjusted by manual or automated means. [0105] In another embodiment, the device may have a single structural element for applying force to the upper stomach or cardia. This device may be fixed into the cardia, fundus, body or pyloric region of the stomach. To further improve the satiety response of this device, it may contain an adjustment of this single element to increase or decrease the amount of force applied to the upper stomach. [0106] The bariatric device in either the three -or single-element embodiments may be self expanding. FIG. 1 depicts an embodiment where the cardiac and esophageal elements 12 , 36 are self expanding. These elements could be self expanding or have a portion that is self expanding to allow the device to flex with peristalsis, but maintain tension to spring open to apply pressure or contact and position within the stomach. The self expanding portion could be made of Nitinol, silicone, polyurethane, PTFE, Teflons, stainless steel, super alloys or other suitable materials or combinations of suitable materials. A Nitinol wire mesh pattern 50 can be applied to a frusto-conical shape to create a shell. The Nitinol wire may act as a stiffening member within the cardiac and esophageal elements 12 , 36 . The Nitinol wire could be arranged in many different patterns to allow for the appropriate amount of self expansion while allowing the element to compress during peristalsis. The array pattern could include circular arrays, angular arrays, linear arrays, or other suitable arrays. The pattern could be woven or a continuous spiral. [0107] The self expanding function may also assist in deployment by allowing the device to compress and then regain its shape. A preferred method of deployment is to compress the bariatric device into a long narrow shape, which is then placed in a deployment tube, sheath or catheter. The collapsed and encased device is then guided down the patient's esophagus and into the stomach, where the bariatric device is released from the deployment tube or catheter. Once released, the device would expand to its original operational shape. The stiffening member, such as Nitinol wire, may provide adequate stiffness to expand the elements into their operational shape, and maintain that general shape during operation, while allowing flexibility to accommodate peristalsis. [0108] As mentioned above, a preferred device has adjustability or adaptability to match any changes in the patient over time. A variation of the above embodiments would be to allow the device to be adjustable via an adjustment element. This adjustability could be in the length, shape, angle or stiffness of the cardiac 12 , esophageal 36 , connecting 25 , and/or fixation elements 31 . Adjustability may be a desirable feature, whether manual or automated. For the present device, there may be numerous adjustment mechanisms. For example, it may be desirable to change the distance between the cardiac 12 and esophageal 36 elements to change the overall length of the device to increase compression of the cardia. This could be achieved by adjusting the length of the connecting element or the fixation element. For the three element device, the adjustment mechanism could be located on the esophageal, cardiac, connecting or fixation elements or any combination of the above. In all cases, the actuation mechanism could be enclosed in a sheath or tube to protect the stomach and to encase the actuation mechanism as needed. A sheath may not be required if the actuation mechanism is designed with smooth contours on its own. [0109] Manual Adjustments: [0110] As mentioned, the adjustment could be applied along the fixation element 31 that holds the device in place or to the connecting element 25 . For example, where the fixation connector 71 is a suture, it could thread through a holding feature (an anchor 72 ) located inside the stomach such as a disk or button. This button (anchor 72 ) could contain a threaded locking pin or a spring loaded locking pin 21 . See FIGS. 2A , 2 B, 2 C, and 2 D. When an adjustment is required, the pin 21 could be released and the suture could be grasped with an instrument and pulled to change the suture length. When the proper length had been achieved, the locking pin 21 could be repositioned to lock the suture into place. The holding feature could also have a winding element 23 to allow the suture to be wound into the holding feature to reduce the length. Similarly, the suture could have positional features such as knots or bead that could be pulled through a cord stop feature and would prevent the suture from pulling backwards. [0111] It may also be desirable to change the shape of the device, such as to increase the diameter or angle of the device. It may also be desirable to increase or decrease the stiffness of the device to increase resistance of the device against the tissue. This could be achieved by a modular stiffening member 24 or a modular piece. See FIGS. 3A , 3 B, and 3 C. The stiffening member could be fixed with a suture or placed into a connection pocket, or modular connector 39 after the device was in place to add additional stiffness to the proximal cardia. The stiffening member 24 could be in the shape of a tear drop or oval and be relatively flat in profile. The stiffener could be placed on the outside or inside surface of the cardiac element. When the stiffener was connected to the device it will flex to the curvature of the cardia and fundus and act like a spring to apply additional pressure against the proximal cardia or upper stomach. The preferred material for this member would be Nitinol, but could be made from other materials. This member could be made of a variety of shapes, profiles and stiffnesses. This feature could also be achieved by applying a spacer or conical liner 26 to the existing cardiac element. This piece could have a different profile or stiffness and attach to the existing fixation to apply to greater force to increase resistance. [0112] Another variation of this embodiment would be to allow spacers 26 to be placed in between the cardiac element and the cardiac wall. Such a spacer 26 may fit into a pocket or feature of the cardiac element to apply outward force for additional pressure against the cardia. The spacers could be made from solid or hollow sections of polymers, silicone, foam, wire mesh or the like. The spacers could also be constructed of self expanding Nitinol features or springs that could apply pressure to the cardia or upper stomach, but give during peristalsis. See FIGS. 4A , 4 B, and 4 C. These self expanding Nitinol spacers 26 could have a variety cross-sectional shapes, angles, and resistance to allow for a range of compression to be applied to the cardia. See FIGS. 4D , and 4 E. Such Nitinol spacers 26 may be wire mesh, coated wire mesh, a wire mesh incorporated into a material such as silicone, or other suitable construction to maintain its shape while retaining some flexibility. FIG. 4B shows an example where multiple spacers 26 could be used to fit in between the fixation element 31 or one large spacer 26 could be used as shown in FIG. 4C . The spacer 26 could be removed endoscopically with a collapsing drawstring and then replaced with a different spacer 26 to change the amount of pressure applied to the cardia or upper stomach. As shown in FIGS. 4D and 4E , the spacer 26 could be self expanding material, shaped like a one sided arch, a hemicone, a hemi-frusto-cone, a generally conical shape or other suitable shapes. [0113] Another variation would be to have a spacer 26 in the form of an inflatable body 27 attached to the top of the cardiac element in the cardia or upper stomach. See FIGS. 5A , 5 B, and 5 C. The inflatable body 27 could be in the shape of a portion of a frusto-cone to provide local focused adjustment to the proximal cardia. There could be several spacers 26 in the form of inflatable bodies 27 attached by a fluid path as in FIG. 5B or there could be one inflatable body 27 as in FIG. 5C . This may be advantageous depending on where the fixation element 31 is attached to the device, the cardia and esophagus. This inflatable body 27 could be accessed through a self sealing membrane or inflation element 28 . The self sealing membrane could be an injection port or it could be a self sealing surface on the inflatable body 27 , or the entire inflatable body 27 could be comprised of a self sealing surface. In all descriptions below, the term inflation element can also refer to an injection port or to an area on the inflatable body 27 with a self sealing membrane. The self sealing membrane could also be a self sealing valve such as a slit valve which can be accessed by a blunt needle or tube to allow access to add or remove fluid. FIG. 5A shows an inflation element 28 that is attached to the device and can be accessed by a blunt needle or small tube instrument to add and remove fluid. As fluid is added, the inflatable body 27 inflates in profile to compress the cardia to create a sensation of satiety. [0114] An alternative would be to have an inflation element 28 that is attached by a length of tubing 29 . The tubing 29 could be straight or coiled. FIG. 6 shows a coiled tube or retractable leash 29 with an inflation element 28 or valve attached to the end of the leash. This would allow the leash to be accessed endoscopically by an instrument, and then extracted up the esophagus for access outside the body. Using an instrument, the inflation element 28 or valve could be accessed to add or remove fluid, and then placed back down the esophagus and into the stomach. [0115] Another embodiment to adjust the length of the fixation element 31 or connecting elements 25 could use spacers. In this embodiment, the fixation element 31 may employ a first anchor 70 with a fixed profile, a connector 71 , and a second anchor 72 that can change in profile in the form of a toggling T-bar 20 as shown in FIGS. 7A and 7B . Alternatively, the anchor 72 could be equipped with a collapsible basket 30 that can change profile from long and narrow for pushing through a small opening and changing provide to wide and flat to secure the anchor as shown in FIGS. 7C and 7D . Either the T-bar fixation 20 or the collapsible basket fixation 30 allow the fixation to pass through the esophageal member, esophagus, cardiac member and cardia and then allow then change the profile of an anchor 72 inside the stomach. For example after placement, the T-bar 20 could be grasped and then modular spacers placed above it to adjust the tension placed on the suture and cardia. FIG. 8A shows a spacer 26 above the T-bar 20 connection. Other means of fixation could also be used. The spacer 26 could also be an inflatable body 27 that could expand to act like a spacer to apply more compression to the cardia. This inflatable body 27 could be accessed through an inflation element 28 , not shown, to add or remove fluid. See FIGS. 8B and 8C . [0116] Another variation of a 3 element embodiment is shown in FIG. 8D and has elements that contact the lower esophagus and the proximal cardia. FIG. 8D shows a side view of this embodiment and 8 E shows an isometric view. The esophageal element 36 that contacts the lower esophagus could be a portion of a steep frusto-cone or tube. The cardiac element 12 could be a portion of a flattened frusto-cone or tube. Although the esophageal and cardiac elements of this embodiment are shown as portions of frusto-cones, the members of these elements could be a variety of different shapes, including substantially planar. One of the features of this embodiment is an esophageal and cardiac elements are non-lumenal, meaning they do not form a lumen. These esophageal and cardiac elements could be constructed of silicone, a combination of silicone and Nitinol, or other suitable materials or combinations of materials. These esophageal and cardiac elements could be connected by a shaped connecting element 25 such as a wire form, strut or could be seamlessly integrated into one piece such as with narrow panel. The portion that connects the esophageal and cardiac members could be formed in a right angle or less (an acute angle) to apply compression to the upper cardia. The portion of the connecting element that passes through the gastroesophogeal junction may be low profile to allow the esophageal sphincter to close. FIG. 8E shows an example of the connecting element 25 as a shape set Nitinol wireform with an angle. Since the wireform is low profile made with small diameter wire, the wires could flex and would allow the GE junction to close during peristalsis. The device would be collapsible so it could be placed down the esophagus and then fixed into place from inside the esophagus for a fully endoscopic procedure. The fixation element 31 could comprise one or more fixation connectors 71 held in place by anchors 70 , 72 . The anchors 70 , 72 could be fixed to the esophageal and cardiac elements 12 , 36 alone, or could be fixed to those elements and the esophagus and upper stomach or cardia, or any combination thereof. Then the fixation connector 71 can be passed from inside the esophagus through the esophageal member 36 of the device through the cardia to the cardiac member 12 to fix it in place. See FIG. 8D . More than one point of fixation could be placed to hold the device in place and to apply pressure to the upper stomach. [0117] This device could then contain several types of adjustments. For example, the fixation element 31 that attaches the device in place could comprise an anchor comprising a toggle T-bar 21 . This would allow the toggle to pierce through the esophageal member 36 , esophagus 32 , cardiac member 12 and cardia and then allow the toggle to rotate to create fixation inside the stomach. After placement, the T-bar 21 could be grasped and then a modular spacer or spacers 26 placed above it to adjust the tension placed on the suture and cardia. FIG. 8D shows a spacer 26 above the T-bar 20 connection. Other means of fixation could also be used. The spacer could also be an inflatable member that could expand to act like a spacer to apply more compression to the cardia as shown in similar previous embodiments. This inflatable member could be accessed through an injection site 28 to add or remove fluid. [0118] Another adjustment feature could be to place a spacer 26 in the form of an inflatable member 27 on top of the cardiac element 12 of the device that could be accessed through an inflation element 28 . This inflation element 28 could be a self-sealing septum of a port or it could be incorporated into the balloon surface itself. The inflation element 28 could also be a valve, which may include a self-sealing membrane, that can be accessed by a blunt ended needle to allow fluid to be added or removed. As mentioned previously, the inflation element could be connected to the inflation member 27 by a tube and this tube could be straight tubing or coiled tubing 29 to allow the valve to be pulled up the esophagus and accessed outside the body. As fluid is added the balloon inflates in profile to compress the cardia to create a sensation of satiety. Similarly, fluid could be removed to reduce the sensation of fullness. FIGS. 5A , 5 B 5 C 6 A, 6 B and 6 C,show how a similar balloon could perform on this embodiment. [0119] Another variation of this embodiment would be to allow spacers 26 to be placed into a pocket or feature of the cardiac element 12 to apply outward force for additional pressure against the cardia. The spacers could be made from solid or hollow sections of polymers, silicone or foam. The spacers could also take the form of a shape set self expanding Nitinol feature that could apply pressure to the cardia, but give during peristalsis. These self expanding Nitinol features could have a variety cross-sectional shapes, angles, and resistance to allow for a range of compression to be applied to the cardia. As shown in FIGS. 4A , 4 B, 4 C, 4 D and 4 E, the spacer 26 could be self expanding material, shaped like a one sided arch, a hemicone, a hemi-frusto-cone, a generally conical shape or other suitable shapes. The spacer 26 could be removed endoscopically with a collapsing drawstring and then replaced for a different spacer to change the amount of pressure applied to the cardia. [0120] Another embodiment of this device could allow the connecting element 25 to be modular and replaceable with different angles or positions to increase the compression on the esophageal and cardiac elements 36 , 12 . The esophageal and cardiac members 36 , 12 could both be fixed as shown in FIG. 8D , but the connecting element 25 could be modular. The connecting element 25 could comprise a wire, such as a shape set Nitinol wire that could fit inside of a pocket or feature on the esophageal element 36 and also fit into a pocket or feature on the cardiac element. The wire would attach and apply pressure to the cardia based on the shape set angle. If the pressure were not great enough, the connecting element 25 could be removed and replaced with another that had a more acute angle. Similarly, there could be several positional features of pockets to allow a variety of assembly lengths, angles and configurations with the modular connecting element in place. In another variation, the shape set wire could attached directly to the fixation and not require a separate esophageal or cardiac element. Although Fig, 8 E shows a connecting element made from a single member, the connecting element could be comprised of several members to allow for ease of modularity or attachment. [0121] The device could also be adjusted by other manual means by using a gastroscopic instrument to come into direct contact with the device, in order to adjust the pressure applied by the cardiac element to the cardia wall. The instrument could act as a screw driver to rotate a member to thread the two elements closer or farther apart. The instrument could also act as a pusher or puller to activate a pulley mechanism or a clipping mechanism. For example, the third element could be strut with multiple positional features such as holes, grooves, teeth or wedging. The device could have a feature to engage the ratchet teeth or positional features such as a pin or clip. The instrument could retract the pin or compress the clip and then reposition this feature in the next available location. The instrument could also deliver heat directly to a heat-expanding mechanism (such as one made of Nitinol) for expansion, or a wax or wax-like expansion member. For example, the Nitinol clip could clip into a positional location on the strut. The instrument could heat the clip to release and then reposition it into a different location, remove the heat and allow the clip to re-engage the positional feature to lock it into place. The instrument could also have an inflatable balloon to allow for physical contact with the device to disengage a feature for repositioning into another location. There could be several other means for manually actuating the design for repositioning. [0128] As another variation of the above embodiments, the manual expansion mechanism could be adjusted remotely by an apparatus outside the body, and/or automated. The expansion could be achieved by a small motor that could be driven by an implanted power source or driven by a remote power source such as induction. Energy could also be supplied by an RF signal, kinetic energy, ultrasound, microwave, cryogenic temperatures, laser, light, or thermal power. Power could also be supplied by a battery or implantable power cells that utilize glucose or other means for fuel. [0129] The automated expansion could also be achieved by a pump, a syringe type plunger, a piezoelectric crystal, a bellows, a Nitinol motor, a pH responsive material that changes shape, thermal expansion of a gas, fluid or solid (example wax) expansion, magnet forces or any other type automated expansion or compression mechanism. [0130] The control for activating this mechanism could be a remote control using a radiofrequency signal which can pass through tissue. The remote control could also be achieved by magnetic fields, time varying magnetic fields, radio waves, temperature variation, external pressure, pressure during swallowing, pH of any frequency or any other type of remote control mechanism. [0131] Actuation Elements [0132] Stepper Motor: [0133] To adjust the distance between the cardiac and esophageal elements 12 , 25 to increase the direct force onto the upper stomach or cardia, thereby adjusting the pressure applied by the cardiac element to the cardia wall, the adjusting element could modify the length of the fixation or connecting element 31 , 25 . These elements could be entirely or partially comprised of a flexible, semi-flexible or rigid screw 33 . An actuation element, such as a stepper motor 34 could be placed onto the flexible thread and could drive forward or back to allow the fixation and/or connecting element to draw together or push apart the elements. See FIGS. 9A and 9B . These figures represent a threaded element that can be drawn together or apart. As an alternative, the motor could be modified to contain a lumen to accept a suture or flexible connecting member 71 with a fixation anchor that changes profile 72 or another means of fixation that can pass through a lumen and then expand beyond the lumen for fixation. [0134] The adjusting element may require power to drive the actuation element, in this case the motor. The power could be supplied by an implanted power source such as a battery or it could be powered externally by induction through the coupling of an external antenna and an internal antenna. [0135] An option would be to embed the internal antenna into any or all of the elements. This would allow for fewer structures in the design by encasing the antenna inside of one or more of the existing elements. The antenna could be a simple ring at the top or bottom or obliquely on either element or it could be placed in the wall of the device. The internal antenna could also be attached by a tether, free floating inside the esophagus, stomach or intestine. These could be made from materials to make them MRI compatible and/or MRI safe. This feature could be applied towards any actuation method where it is powered by induction. [0136] For induction, an external hand held controller 86 may be required to transmit power for coupling. See FIGS. 10A and 10B . The controller 86 could be set up to auto detect the internal antenna's presence and identify when coupling between the two antennas was adequate to allow for transmission and powering to take place, and to inform the user of function. This external controller 86 could then be used to display the distance that the stepper motor had been advanced or retracted to allow the physician to control the adjustment. Similarly, the external controller 86 could be used for communication and control signals as an interface between the physician and the placed device. This feature could be applied towards any actuation method powered by induction. [0137] An external antenna would be required for induction and could be placed into an external handheld controller 86 . This could be placed directly against or close to the patient's body at the height of the internal bariatric device. See FIG. 10A . The antenna could be housed with the other controller electronics in a single unit. This feature could be applied towards any actuation method powered by induction. [0138] Another alternative would be to have the external antenna in the form of a belt 87 that would wrap around the patients abdomen at the height of the device to better align the antennas for improved coupling. This feature could be applied towards any actuation method powered by induction. See FIG. 10B . [0139] The location of the actuation mechanism could also be inside any of the elements, or above or below any of them, or another location as would be best suited for the anatomy and function of the device. This feature could be applied towards any actuation method. Actuation could be accomplished by allowing the screw to be pushed or pulled inside any of the elements to embed the adjustment mechanism internally to one of the other elements. Other actuations mechanisms such as those listed above or others could also be used for this adjustment. [0140] Induction could also be powered by an intragastric instrument. The instrument could have a flexible shaft that could fit through the mouth and down the esophagus or down the working channel of a gastroscope. Once the instrument was placed within or near the esophagus or stomach, it would allow the instrument to be in close proximity with the actuation mechanism in the device. The end of the instrument could have antenna(e) to allow for inductive powering and/or communication with the actuation mechanism for adjustment. This feature could be applied towards any actuation method. [0141] Piezoelectric Motor [0142] The adjustment for adjusting the pressure applied by the cardiac element to the cardia wall could also be achieved by a piezoelectric element or motor. See FIGS. 9A and 9B . These figures represent a threaded element that can be drawn together or apart. This feature could be applied to the connecting or fixation elements. [0143] There are several types of piezomotors that could be used for linear actuation. For example, a motor from NewScale Technologies (www.newscaletech.com) called the Squiggle Motor could be used which is very low profile and can be actuated when powered. Other motors or actuation mechanisms could also be used, and the Squiggle motor is just used as an example. In this example, there is a rigid screw 33 that passes through the center of a threaded piezoelectric “tube” or element. When powered the piezoelectric element flexes side to side along the central axis to create an oscillating “hula hoop” action which causes it to translate axially along the rigid screw 33 . The Squiggle motor could be attached to the esophageal, cardiac, connecting element or fixation elements 36 , 12 , 25 , 31 to advance or retract the cardiac and/or the esophageal elements 36 , 12 . Alternatively, the Squiggle motor could be placed in between any of the elements. Alternatively, more than one Squiggle motor could be placed at these locations. One of the advantages of a piezoelectric motor is that it would allow the device to be MRI compatible and safe. As mentioned with the stepper motor 34 above, the piezoelectric motor could be powered by an internal power source such as a battery or it could be powered by remote induction. The remote induction could be by a handheld external controller 86 or it could be by a gastroscopic instrument placed down the esophagus. This motor could be encased in other materials to keep it dry and protected from the stomach environment. [0144] Another embodiment of a piezoelectric actuated motor would be to have a rotating piezoelectric member that could thread along one or two threaded members similar to a worm gear. [0145] Another embodiment of a piezoelectric actuated motor would be to have a piezoelectric crystal that elongates or flexes to actuate another member. [0146] All of the piezoelectric motors may contain a sealed housing such as an expandable metal or plastic bellows to prevent moisture of fluid from contacting the piezoelectric elements. [0147] Magnetic actuation [0148] As mentioned above in the manual adjustment section, another adjustment mechanism for adjusting the pressure applied by the cardiac element to the cardia wall could use magnets. [0149] For example, at least a portion of the connecting or fixation element 25 , 31 could be a semi-flexible thread or rigid threaded member 81 with a magnetic nut 79 placed over it. Another strong magnet, named a controller magnet 80 , could be placed in close proximity to the implanted magnet nut 79 to cause it to rotate. The rotation of the controller magnet could create a magnetic field which would cause the internal magnet to turn allowing it to advance and retract along the threaded member. See FIGS. 9C and 9D . [0150] The controller magnet 80 could either be external to the body or it could be placed on the end of a gastroscopic instrument for close proximity. [0151] The controller magnet 80 could be a magnet or an electromagnet to increase the intensity of the field and to improve magnetic coupling to ensure actuation. [0152] The controller magnet 80 could also be multiple magnets to improve magnetic coupling. [0153] Nitinol Actuation [0154] The adjustment element could also be actuated by Nitinol or a substance with similar properties. When a current is passed through Nitinol, it heats and causes the Nitinol to change its shape. Nitinol can expand into a variety of different shapes. A linear actuator could be made from Nitinol to advance or retract along an actuation member. [0155] Heat could be generated from an implanted battery or it could be delivered by induction. [0156] The cardiac, esophageal, connecting or fixation 12 , 36 , 25 , 31 element could have multiple positional features such as holes, grooves, teeth or a wedging feature. A Nitinol clip could have a feature to engage these positional features. The Nitinol clip could be heated to change shape to allow it to advance or retract into different positional features to increase or decrease the length. [0157] There are other Nitinol actuations that could be provided as well. [0158] Ultrasound Motor [0159] Another adjustment mechanism could be by use of an ultrasound motor or one powered by external ultrasound. This could use external ultrasound equipment to send sonic waves into the body to actuate the motor. This would also provide an MRI compatible option without requiring an internal power source or induction. [0160] Hydraulic Actuation [0161] The adjustment element could also be actuated through hydraulic means for radial expansion, linear actuation, shape change or stiffness change as previously described. The cardiac or esophageal element 12 , 36 could be inflated with a fluid to increase the profile, diameter or length of the device to increase pressures against the upper stomach or cardia. It could increase in volume by accessing a self sealing membrane such as a self sealing drug delivery port, self sealing membrane on the expandable body, or a self sealing valve attached to the device. The inflation could be achieved by a piezoelectric pump, a peristaltic pump, a positive displacement pump or a syringe pump. [0162] Piezoelectric pump: The pump could be comprised of a piezoelectric element which can flex to propel fluid directly or a member that could propel fluid. For example, a piezoelectric disk could be captured in a housing with an incoming channel and an outgoing channel. The disk could be powered to cause it to flex into a dome shape to push fluid into the outgoing channel. A valve would be required to close the incoming channel to ensure directional flow to the outgoing channel. Similarly, the piezoelectric Squiggle motor as described above could be used to linearly actuate a fluid up or down a tube to hydraulically actuate position. [0163] Stepper motor pump: Actuation could be achieved by a stepper motor where the motor linearly actuates to compress a reservoir or syringe to move fluid within a tube or constrained volume. [0164] Wax expansion pump: Fluid could also be propelled by a wax expansion mechanism. When wax is heated to melting it expands by approximately 30%. A solid plug of wax could be heated to expand and drive fluid through a valve to hydraulically actuate lengthening. The lengthening structure could be made to move only in one direction, so that when the wax cools it will not contract. The wax expansion could also be used to actuate other adjustment mechanisms. [0165] Peristaltic pump: The members could also be driven by a peristaltic pump. In this mechanism, the external diameter of a cylindrical actuator could be used to compress a length of tubing to create an occlusion. The cylindrical actuator could be rotated along the tube to drive fluid forward or backwards inside the tube. The peristaltic pump could also be actuated by a stepper motor or by a piezoelectric element or other. [0166] Gas expansion/propellant pump: The length could also be actuated by a gas expansion pump where a gas like Freon or others could be used to expand when exposed to a higher temperature. Similar principles to the devices like the Codman pump could be used. This change in volume could drive the pump forward. Similarly, there could be compressed gas constrained in a pressure vessel with a valve. The valve could be remotely activated to allow gas to propel a syringe, fluid or to compress a constrained volume. [0167] Positive displacement pump: There are implant grade positive displacement pumps that are available on the market for drug delivery that could be used to displace a specific amount of fluid for hydraulic inflation of the adjustment element. [0168] Syringe pump: A syringe pump could be made by advancing fluid through a syringe. The syringe could be actuated by a stepper motor, a piezoelectric actuator, a magnet or by a Nitinol actuator as described above. [0169] Hydrogel: the adjustment element could also be inflated by use of a hydrogel to absorb fluids and could be actuated by changes in temperature, pH or tonicity to change shape or volume [0170] Hypertonic fluid: the adjustment element could also be inflated by using a hypertonic fluid in the inflation area and allowing it to absorb fluid across a semi permeable membrane. [0171] Mechanical means for diametrical or profile changes. Similar to the inflation, elongation, and shortening embodiments described above, the device could change diameter by various actuation mechanisms. All of the above-described mechanisms could also be adapted for use for a diametric change instead of a linear change. [0172] As a variation of the embodiments discussed above, the device could have a sensor that could sense a parameter such as pressure, motion, peristalsis, tension, pH, temperature, chemical or other appropriate parameters, or various parameter combinations. The sensor could output a signal to be used by an actuation element to actuate an adjustment element, to a memory element such as a microchip, or be read by a remote reader or remote controller. [0173] Sensors 88 could be used to gather important patient data to understand fit, performance, patient status, whether an adjustment needs to be performed, and as a guide while an adjustment is performed. For ease of use and compatibility with the body, wireless sensors would be preferred. In some applications, it may be desirable to sense a parameter without the need for adjustability. In other applications, adjustability for adjusting the pressure applied by the cardiac element to the cardia wall may be a desirable feature. The sensors 88 could be in direct tissue contact, intermittent tissue contact or could monitor the intraluminal pressure inside GI tract. The data could be used for no other reason than to just monitor patient status and performance. FIGS. 11A and 11B depict sensors 88 , which could be embedded in any of the element surfaces for direct tissue contact, non-tissue contact or it could be tethered to any of the elements to allow it to be suspended inside the GI tract. Based on the sensed parameter, the device could be adjusted. The adjustment could have an open or closed loop system increasing or decreasing the applied force, pressure or sensed parameter. The sensed parameter could detect whether the device was not at an ideal condition, and could then send a signal to a control mechanism for automatically adjusting the system. This mechanism could be under physician control (open system) or without physician control (closed system). The adjustment could also be a manual adjustment where the parameters are being monitored to guide the adjustment. It could also control the shape of the cardiac, esophageal, connecting, and/or fixation elements 12 , 36 , 25 , 31 to vary stiffness, size, length, form or shape. In general, the sensor 88 could sense a parameter and then adjust the device as needed to bring the sensed parameter into the ideal range. There could be an algorithm that controls the ideal parameter or it could be based on a parameter range. The device would be adjustable to meet the needs of the patient. [0174] In an open loop system, the physician would have control of when the device would adjust the pressure applied by the cardiac element to the cardia wall. The device could have its own internal power source, or it could be passive and only inductively powered when in close proximity to an external controller 86 under the supervision of a physician. For example, in the clinic the physician could have a remote controller 86 with the ability of powering the device inductively, and then begin to monitor the sensors 88 feedback signals to see physical parameters of the patient at baseline such as pressure of the device against the cardia. The sensor monitoring could also be performed while the patient is eating or drinking, or not eating or drinking As the patient consumes, the esophageal and stomach peristaltic waves will increase in intensity as they propel the food or drink from the mouth to the stomach. A sensor 88 could detect when these waves increase in amplitude, frequency, and pressure. The parameter could read on the external controller by the physician, and then the physician could send a signal to the automated expansion mechanism in the device to adjust the device. The physician could then query the sensor 88 again to determine whether the device was in the ideal settings and whether the pressure against the cardia or sensed parameter was optimized. The physician could iteratively control the amount of adjustment and monitor the parameters until the ideal condition was met. Where the device has its own power source, the physician would still have the control to wake up the device, query the sensors and then adjust the device as described above. The only difference would be that the device was powered by the power source and not require inductive power from outside. [0175] Alternatively, the physician could read the parameter signals while under his supervision, but have the sensors 88 send a signal directly to the automated expansion mechanism to adjust the pressure applied by the cardiac element to the cardia wall until the device was within the ideal parameters. The data collected could be analyzed by the controller for averages, minimums, maximums and standard deviations over time and use an algorithm to determine the ideal settings. The controller could then monitor and adjust on its own until the ideal conditions were met, but while the physician was present to verify all conditions and verify patient acceptance. [0176] In a closed loop system, the device would be active with its own integrated power source. The device could wake up at routine intervals to monitor or could monitor all the time. The data collected could be analyzed for averages, minimums, maximums and standard deviations over time and use an algorithm to determine the ideal settings. As the patient begins to consume food or drink, the device sensors would detect the sensed parameter and signal the automated expansion/contraction mechanism to adjust the device as needed. In this embodiment, the device could be fully automated and would not require intervention from an outside individual. [0177] In either the open or closed loop system, there could be multiple sensors 88 on the device to determine the pressure or force areas, or other sensed parameters on the device and where it needs to be varied to meet the ideal conditions for the stomach. In the case where the fixation and/or connecting 31 , 25 element has multiple members, this could be used to align the device in the stomach to provide a custom fit and response for each person. There could also be a mechanism to adjust the alignment of the cardiac and/or esophageal elements 12 , 36 relative to the connecting and/or fixation elements 25 , 31 . The sensor(s) 88 could have a built in power source or it could have a remote power source such as induction so that it would only wake up and activate when an external controller was brought near. [0178] The device could have integrated memory to allow storage of patient and device data. This could include but is not limited to the serial number, the patient's information such as name, patient number, height, weight; the physician's name, the adjustment history including the date and time, the amount adjustment and the sensed parameters. For the active device, there could be 24 hour data recording of key parameters or there could be data collected at key intervals throughout the day to detect when the patient is eating and whether they are being compliant with their eating. It could record weight tracking, BMI or other data as needed which could be queried by an external controller. This data could also be downloaded into a physician's patient tracking database for ease of patient tracking Similarly, this data could be downloaded and tracked on an internet tracking website, where the patient could log on and see their history and progress. The patient could add information to the website such as weight or an eating log, adverse events or other conditions that the physician or patient would like to track. [0179] In the open system, the physician could choose to collect and record data as needed at the time of the adjustment such as weight, date, time, and adjustment amount or other. [0180] For an open loop system, the device could be adapted to allow for remote adjustments over the phone. This would be especially advantageous for patients living in rural areas where they are far from their physician's office. It could also be for convenience of having an adjustment without having to travel to the physician's office. This would allow a physician to discuss the patient's progress with the patient directly and then query the device sensor to see how the device performance is. Based on the feedback of the device, the physician could then adjust the patient. [0181] In yet another embodiment, the device could have an emitter element for dispensing a drug, hormone or bioactive agent to further induce satiety, weight management or other disease management such as diabetes. The drug could be a weight management drug currently on the market or one to be developed. Similarly, it could be a satiety hormone or other bioactive agent. In the published literature, there is a growing mass of information on satiety hormones. The bioactive agent could be applied by the emitter element through a drug eluting coating, a reservoir with a pump, or a permeable membrane placed on the device where the drugs could pass from the device into the gut. The emitter element could release such substances in response to a signal from a sensor, a timed basis, or other release criteria. The device could have a tube that trails into the intestines to allow the drug to be delivered downstream where the pH is higher and would not destroy the bioactive agent. [0182] The device could have a surface finish or macrotexture for gripping the stomach. If the device could grip the inner mucosa of the stomach or esophagus, it could elongate or expand to further stretch the stomach or esophagus in key areas to induce further satiety as needed. For example, the cardiac element could be a conical spiral or other shape with a surface texture that lightly grips the mucosa and or stomach musculature. If the spiral were made of Nitinol or other temperature-sensitive substance, the device could expand the spiral by a variation of temperature. By applying a temperature variation, such as by drinking a hot liquid or otherwise, the device could expand and cause a satiety response. The surface could be multiple protuberances, barbs, a rough bead blast, or other finishes suitable for gripping the stomach wall. [0183] As a variation of the device, it could incorporate electrical stimulation to the stomach musculature, stomach nerves or the vagus to further improve satiety stimulation and weight loss. Energy used for this stimulation could be RF, ultrasound, microwave cryogenic, laser, light, electrical, mechanical or thermal. The device could have leads incorporated that could embed into the stomach wall or be surgically placed around a nerve, or the stimulation could be applied directly through surface contact of the device to the stomach mucosa. [0184] Single Cardiac Member: [0185] Another embodiment has a single cardiac member that is fixed to the cardia or other region of the stomach with an anchor and applies pressure to the cardia or upper stomach. All of the improvements described above including adjustability mechanisms, manual adjustability, remote adjustability, sensors, data collection, memory, and others may be applied to such devices. [0186] For example, some bariatric devices have a member with a flat button anchor 70 with a T-bar 20 attachment into the cardia. In such a device, an adjustment feature may be applied to increase or decrease the amount of compression applied to the cardia. As mentioned above, several adjustment mechanisms for adjusting the pressure applied by the single cardiac member to the cardia wall could be used such as a stepper motor, a piezoelectric crystal element, hydraulic adjustments, gas or solid expansion, variable tension springs, Nitinol actuation, or any other adjustment noted above. Similarly, the device could be adjusted to change shape such as to increase the surface contact to the cardia or it could change the stiffness to increase resistance. All of these embodiments can be placed and removed endoscopically with a gastroscope and instruments down the esophagus. [0187] FIG. 12 shows an embodiment of a single cardiac 13 member where one or more of these single cardiac 13 members could be fixed into the cardia directly at the site where pressure is to be applied. In this embodiment, there is a button anchor 70 with a connecting element 71 that pierces through the cardia with a T-bar 20 which then toggles flat to hold it in place. It also contains a flexible disk or distribution element 61 to distribute the load across a greater surface area than just the button. This also shows sensors 88 that could be located so they contact the patient's tissue or could be located on the outside of the device to monitor the intraluminal pressure. This could be used for monitoring the patient's baseline data, or gathering a variety of other data. [0188] FIGS. 13A , 13 B, 13 C, 13 D and 13 C show several options of fixation elements 31 for fixing the single cardiac member 13 to the cardia. 13 A shows a corkscrew or tacker type fixation which would allow the device to be threaded into the place. FIG. 13B shows an elongated anchor 72 with multiple arms that are elongated and collapsed for placement, and 13 B shows the same device in its deployed state where the anchor 72 arms curl or spring into a wide, atraumatic profile. The arms are made of shape memory or super elastic material or spring material that changes shape once an elongation force is removed from the device. For example, the device may be placed into a sleeve that holds the curled arms straight. As the arms are advanced out of the sleeve, they puncture through the tissue and then change shape to hold the device in place. In a variation, FIGS. 13D and 13E show another anchor 72 that has shape memory or super elastic qualities where the deployed fixation element 72 shown in a flat spiral shape in 13 D, can be completely straightened by placing it into a sleeve and then advancing it until it pierces through the cardia and then springs back into the shape of 13 D. FIG. 13E shows the same fixation element with a slightly elongated shape 51 to allow it to pierce the cardia and then spring back into the shape in FIG. 13D . These are examples of fixation elements, and other mechanisms could be used for fixation. [0189] FIGS. 13F and 13G show an adjustment element 60 that could be used for adjusting the length of the member across the cardia to control the amount of compression applied to the cardia, to adjust the pressure applied by the single cardiac member to the cardia wall. This embodiment shows a distribution element 61 to distribute load across a larger area. This distribution element 61 could be a flat, flexible disk or it could also be a conical shape, spherical, or other shape to improve load distribution or distribution profile across the area. The distribution element 61 could be of a variety of materials which are very soft to firm such as silicone, polymers, foams, Nitinol or it could be a combination of any or other suitable materials. This element could have a single central shaft or connecting element 71 as shown in FIG. 13F or it could have 2 connecting elements 71 that anchor the device for rotational stability as shown in FIG. 13G . The adjustment element 60 could rotate around a central shaft or it could rotate between the 2 shafts. Similarly, the element could have a plurality of shafts for fixing to the cardia. [0190] FIGS. 14A , 14 B, and 14 C depict 3 different embodiments for actuating a single cardiac member 13 . Although the fixation anchor 70 is shown in the drawing as a button, the anchor could also be flat, conical, spherical or other shape. Several adjustment elements could be used for adjusting the pressure applied by the single cardiac member to the cardia wall. FIG. 14A shows a stepper motor 34 that is inductively powered and controlled. The stepper motor could then thread up and down the central shaft to compress the cardia tissue as needed. A sensor 88 could be applied to this embodiment. Optional locations for a sensor 88 are shown. As mentioned above, these embodiments could have 2 or more shafts. FIG. 14B shows a magnetic actuation for adjustment. In this embodiment, there could be a threaded magnetic element 79 that could be rotated by placing a controller magnet 80 in close proximity. As the controller magnet 80 is rotated, its magnetic field causes the magnetic element 79 to rotate. As mentioned above, the controller magnet 80 could be an electromagnet to increase the magnetic coupling or it could include multiple magnets. FIG. 14C shows a piezoelectric element 62 , where a piezoelectric element is able to oscillate and rotate to increase or decrease compression against the cardia. A piezoelectric element 62 could also be designed to flex to move the adjustment to different positional locations. FIG. 15A shows another piezoelectric element 62 . In this embodiment, the piezoelectric motor 62 is encased in a metal or sealed bellows 63 to seal the element from moisture, if needed. For all the embodiments, they may need to be encased in an acid-resistant and/or moisture resistant barrier. FIG. 15B shows a hydraulic and manual actuation mechanism. In this embodiment, the cardiac member has a self sealing membrane or inflation element 28 that connects to an inflatable balloon. By using a non-coring Huber tipped needle, the needle could be placed down the esophagus and pierce the self sealing membrane to inject or remove saline to expand or contract the balloon to alter the compression. The inflation element could also contain a self sealing valve. In FIG. 15C , another manual adjustment mechanism is shown where the threaded button 64 can be accessed by a screwdriver and rotated along the threaded member 81 . This would allow the button to be moved up and down to increase or decrease compression against the cardia. Any type of tool and screw or bolt head feature could be incorporated into the threaded button 64 , including Torx, Phillips, polygonal sockets or external bolt heads, or other suitable bolt or screw heads. Gripping feature such as macrotexture could be added to the cardia contacting surface of the fixation element 31 to grip the cardia to prevent it rotating while 64 was being rotated. [0191] A sensor could be placed on the surface of on any element of the device to contact the patient's tissue, or not placed to contact the patient's tissue to gather intraluminal pressure of the stomach, esophagus or intestinal tract, or placed to contact the tissue intermittently. The form of the device could be a single button attached to the cardia or it could be a device with a wall or coil that shapes a cone. [0192] Another alternative would be to connect several single cardiac members with another element such as a loop, band or balloon. See FIG. 16A . In this case, the loop or single cardiac connecting element 65 could be adjusted in length to create a force against the single cardiac member 13 to increase tension against the device, thereby adjusting the pressure applied by the single cardiac member to the cardia wall. The length of the loop could contain an adjustment element 60 which could be expanded to create a greater stretch to engage the stretch receptors. The length of the loop could also be reduced to engage the stretch receptors. The element could pass through a hole or engage a feature in each of the single cardiac members 13 . The length of the loop could be adjusted by all of the various methods already described in this invention such as using a stepper motor, magnetic actuation, a piezoelectric element, hydraulic adjustments, gas or solid expansion, variable tension springs, Nitinol actuation, or any other adjustment noted above. FIGS. 16A , 16 B, and 16 C shows options for adjustability such as use of a motor 34 , magnetic actuation of a magnetic nut 79 by a controller magnet 80 or an expansion joint 75 using inflation by a linearly expanding balloon, but other options for adjustability may be used. [0193] FIGS. 17A , 17 B, and 17 C show an embodiment of a cardiac button 82 which comprises a plurality of penetration prongs 83 which are preferably claw like structures with two ends, hingeably coupled at one end with a coupling element 84 in a generally radial pattern. The generally radial pattern could also vary from true radial, such as 2 sets of parallel prongs at the corners of a square. The penetration prongs 83 could have a long narrow profile, and could be straight, curved, or have a hook or curl at the free end. When the penetration prongs 83 are in an expanded state, their free ends may extend beyond the diameter of their connection point to the cardiac button 82 , giving them a splayed appearance as in FIG. 17B . When in a compressed state the free ends of the penetration prongs 83 may approach each other and may even touch, as shown in FIG. 17C . The penetration prongs 83 could be made of a material with spring or super elastic properties to allow them to compress, or a spring mechanism may be incorporated into the cardiac button 82 . The penetration prongs may be compressed into the closed state for placement into the cardiac tissue, and then expand into the deployed open state. This would allow for distension of the cardiac tissue. In another embodiment, the penetration prongs 83 could be constructed so that they are in the expanded open state for placement and then collapse to the deployed closed state after placement. This would allow for compression of the cardia tissue. When the embodiment is in the compressed closed state, it can pierce through the cardia for placement and then take the deployed expanded state open to cause the cardia to stretch to engage the stretch receptors and cause satiety. FIG. 17D shows where the element in the expanded open state has penetration prongs 83 that curl into an atraumatic profile. Similarly this device could work in compression where the device is placed in the expanded open state and then closes to compress the tissue engage the stretch receptors. This embodiment could be further improved by having adjustability such as any of the adjustability features already mentioned above. An alternative to this embodiment would be to make the device that changes shape when exposed to a temperature or other stimuli change. This device could further contract or expand when exposed to a hot or cold liquid or stimuli to allow for a temporary adjustment. The adjustability mechanisms described above, including adjustability, remote adjustability, sensors, data collection, surface texture and adjustments over the phone, may be applied to such devices. [0194] Another embodiment would be to have a single cardiac member 13 which only contacts the proximal cardia and is fixed in place with a fixation element 31 . This device may have the shape of a portion of a frusto-cone or tube and is fixed in place at each of the 4 corners of the element. Although the element takes the shape of a portion of a frustocone, it could take the shape of a flat panel, a portion of a tube, an oval, a disk or any other suitable shape. See FIGS. 18A and 18B . Although 4 points of fixation are shown, there be could be more or less fixation. This element could be thin walled and could be made from silicone, a combination of Nitinol and silicone, or other suitable materials or combinations of materials. Preferably, the device is self- expanding and would have adequate structure to impart force against the cardia or upper stomach when fixed at the corners, but would be flexible enough to accommodate peristalsis. Several types of fixation could be used, including and not limited to those previously disclosed. The procedure could be performed gastroscopically by placing the fixation from inside the stomach through the single cardiac member 13 , through the stomach wall, and to the outside of the stomach wall on the serosa. Since the device is self-expanding, it may be collapsed for placement down the esophagus and then reforms in the stomach where it can then be fixed into place. As shown in FIGS. 7A and 7B , the fixation element 31 could be an anchor 72 in the form of a t T-bar with a button on one side. This would allow the smooth button to be inside the stomach, and the T-bar to pierce the device and stomach wall. The fixation element 31 could also be an anchor 72 in the form of a collapsible basket as shown in FIGS. 7C an 7 D, which then expands to hold the fixation. The fixation element 31 could also be other types of expandable anchors, standard sutures or other types of fixation. [0195] This device could then contain several types of adjustments for adjusting the pressure applied by the single cardiac member to the cardia wall. For example, there could be an inflatable body 27 that could be placed on top of the cardiac portion of the device and against the stomach wall that could be accessed through aninflation element 28 . See FIGS. 18A and 18B . This inflation element 28 could be a self-sealing septum of an access port, or the self sealing septum could be incorporated into the balloon surface itself. The inflation element 28 could also be a valve that can be accessed by a blunt ended needle to allow fluid to be added or removed. Similar to the embodiment in FIG. 6A , the inflation element 28 could be connected to the inflation member by a tube 29 . This tube could be straight or coiled, with or without a housing, to allow the valve to be pulled up the esophagus and accessed outside the body. As fluid is added, the balloon inflates and compresses the cardia to create a sensation of satiety. After the balloon has been adjusted, the tubing can then retract and be placed back into the stomach. The tubing may be retracted into a housing, which may have a coiling mechanism. The tubing, with or without the housing, is preferably configured to stay in the stomach and not pass through the pylorus. FIGS. 18C and 18E show the inflatable body 27 in the deflated state, while FIGS. 18D and 18F show the inflatable body 27 in the inflated state. [0196] Another variation of the embodiment would be to place spacers 26 into a pocket or feature of the single cardiac member 13 to apply outward force for additional pressure against the cardia or upper stomach to adjust the pressure applied by the single cardiac member to the cardia wall. The spacers could be made from solid or hollow sections of polymers, silicone or foam. The spacers could also take the form of shape set self expanding Nitinol features that could apply pressure to the cardia, but accommodate peristalsis. These self expanding Nitinol features could have a variety cross-sectional shapes, angles, and resistance to allow for a range of compression to be applied to the cardia. See FIG. 19 . Spacers similar to those shown in 4 D and 4 E could also be used in this embodiment, but other shapes could also be used. The spacer could be removed endoscopically with a collapsing drawstring and then replaced for a different spacer to change the amount of pressure applied to the cardia. [0197] In another embodiment, an element may be used to contact the cardia, but may be fixed into place by a fixation element 31 in the fundus, body, or pyloric region of the stomach. This fixation could take place along the lesser curve, greater curve or midline of the stomach. FIG. 20 shows a side view of an embodiment where a cardiac element 12 is positioned at the proximal cardia. This cardiac element 12 is attached to a positioning element 66 which has a connecting joint 105 for attaching a fixation element 31 to fix the device to the stomach wall. The cardiac element is constructed with a self expanding Nitinol wire mesh pattern 50 . FIG. 21A shows a backside perspective view of this device and FIG. 21B shows a front view of this device. Preferably, the cardiac element is made of a self expanding structure to maintain its form in the stomach while accommodating peristalsis. The positioning elements are also preferably made from a shape memory or super elastic material to maintain structure while accommodating peristalsis. With self expanding elements, the device may be collapsed for placement down the esophagus and then expand once in the stomach for fixation to the stomach wall. FIG. 22 shows a side view of an alternative embodiment where the positioning element 66 , connecting joint 105 , and fixation element 31 are located along the lesser curve. FIGS. 23A and 23B show a backside perspective view and front view of this embodiment. Adjustability, sensors, remote control and all other improvements and features previously disclosed herein apply to this embodiment. [0198] The bariatric device may have an adjustment element that is equipped with a temporary expansion/contraction element 90 that may allow for temporary adjustment based on activation of a material property, sensor 88 or mechanism of the device. This could be applied to any of the above-discussed embodiments. FIGS. 24A shows a cardiac element in the unexpanded state and 24 B shows the cardiac element in the expanded state. It may be desirable for the temporary expansion/contraction element 90 to adjust only upon eating, and then retract after eating. It may be desirable for the device to adjust upon eating and then retract after eating. It may be desirable for the device to adjust with the pH cycle of the patient where pH will be higher prior to eating and then lower after eating. This would allow for intermittent stimulation of the stretch receptors to avoid receptor fatigue over time. For example, the material could be heat sensitive using materials such as Nitinol, which could expand after consuming a cold or hot liquid. The time and duration of the adjustment could be varied up on the desired response. [0199] Similarly, the device could have a sensor 88 or material that is pH or glucose sensitive or detect the presence of food, which could activate the temporary expansion/contraction element 90 to expand when a certain threshold for pH has been reached or glucose, carbohydrates, protein or fat is present after eating. Similarly, this temporary expansion/contraction element 90 could be activated by a magnetic field such as swallowing a magnetic pill that could temporarily expand the device. In this example, the magnetic pill would be small enough and shaped appropriately for passage through the gastrointestinal tract, and be biocompatible. The patient could consume the electromagnetic pill when a satiety signal was desired. It may also be desirable for the device to adjust based on time or sleep cycle such that the device 10 adjusts at specific times of the day or when the patient lays horizontal. Other parameters or mechanisms to trigger the temporary expansion could be used. [0200] Another alternative would be to suspend these devices from either the left or right crura of the diaphragm, or both instead of fixing directly to the stomach wall or esophageal wall. [0201] Devices for Placement with a Gastric Band or Gastric Bypass [0202] All of these devices could be modified for use with a gastric band or bypass patient. See FIGS. 25 , 26 and 27 . FIG. 25 shows a 3 element embodiment with a gastric band. This may be desirable in a patient with a gastric band or bypass where the weight loss has slowed or weight gain has started. In all cases, the devices may need to be sized appropriated to fit within the reduced size of a gastric bypass or gastric band pouch. Although the figures show a gastric band, it is intended to also represent a reduced pouch size of a gastric bypass, a sleeve gastrectomy or other bariatric procedure. Due to the reduced lumen or constriction of the gastric band or bypass below the pouch, the device may be placed without fixation into the stomach wall. FIG. 26 shows how a single cardiac member 13 could be used with a small pouch. FIG. 27 shows an embodiment where a cardiac element 12 could be placed above the gastric band to contact the cardia or upper stomach. This also shows that the geometry is large enough to prevent migration of the device past the band. The embodiment shows a spherical profile or ellipsoid profile to better match the pouch geometry, but other shapes and profiles could be used. This device could be placed temporarily and could be replaced by different shapes or sizes. This feature would be particularly interesting for failed gastric bypass patients who do not have the opportunity for a reversal or for gastric band patients who do not want to undergo surgery, but want to stimulate satiety. This device could be made from silicone, polymers, Nitinol or a combination of any of these. Preferably, this device is made from a self expanding structure to provide pressure against the cardia, but accommodate peristalsis. Self expansion would also allow the device to compressed for placement down the esophagus and then expand into its operational shape and collapse for retrieval. [0203] Placement [0204] As mentioned above, a tube, catheter, or sheath may be required to protect the anatomy during placement of the device down the esophagus and into the stomach. For the small single cardiac embodiments, a sheath may not be required due to the small size. Where protection is require, it could be a simple flexible tube to aid in straightening and compressing the device while it is being introduced. Insertion of the device into the tube would require compression of the device into a narrow, streamlined shape. A standard gastroscopic tool could be used to push or pull the device down the tube. Similarly, a custom gastroscopic tool or sheath could be used to introduce the device into the stomach through the esophagus or other narrow opening. [0205] Removal [0206] For removal, a flexible tube such as a standard overtube could be used with a standard or custom endoscopic tool. The tube may be placed down the esophagus and the tool then placed down the lumen of the overtube. Endoscopic scissors or cautery could be used to cut fixation where necessary and a standard grasper or snare could grasp the device and pull it up the tube. The device would be straightened by the overtube for removal from the stomach and esophagus. The device may be flexible and small enough in profile to pull up the overtube with a standard grasper. [0207] In another embodiment, the elements may incorporate a collapsing mechanism designed to collapse the element into a compact shape for removal. For example, a constriction member comprising a wire or thread may be sewn spirally around, through, or inside the length of one of the elements. The ends of the constriction member may be connected. When the constriction member is pulled, it tightens the circumference of the element like a drawstring, which collapses the element down to a narrow profile that can be safely removed through the esophagus or other narrow opening, or ease its placement into a tube for removal. The constriction member could be made from Nitinol, stainless steel wire, polypropylene, PTFE thread, EPTFE thread or PTFE coated threads or other suitable materials. The constriction member could be integrated into the elements in a variety of patterns such as a continuous spiral, two spirals of reversing orientation, a single loop or other. [0208] The foregoing description of the preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention not be limited by this detailed description, but by the claims and the equivalents to the claims appended hereto. INDUSTRIAL APPLICABILITY [0209] This invention may be industrially applied to the development, manufacture, and use of bariatric devices for weight loss purposes.

A bariatric device for use in inducing weight loss, comprising a cardiac element and a fixation element wherein the fixation element attaches the cardiac element to the upper stomach to allow the cardiac element to apply at least intermittent pressure to the upper stomach which produces a satiety signal to the user, giving the recipient a feeling of fullness and reducing his or her hunger feelings. The device may also contain an esophageal element which is connected to the cardiac element by a connecting element.

This nonprovisional application is based on Japanese Patent Applications Nos. 2004-319115 and 2005-081858 filed with the Japan Patent Office on Nov. 2, 2004 and Mar. 22, 2005, respectively, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine including first fuel injection means (in-cylinder injector) for injecting fuel into a cylinder and second fuel injection means (intake manifold injector) for injecting fuel towards an intake manifold or intake port. Particularly, the present invention relates to the technique of obviating attachment of deposits at the injection hole of the first fuel injection means even in the event of abnormality in the fuel supply system that supplies fuel to the first fuel injection means. 2. Description of the Background Art An internal combustion engine is well known, including an intake manifold injector for injecting fuel into the intake manifold of the engine and an in-cylinder injector for injecting fuel into the engine combustion chamber, wherein the fuel injection ratio of the intake manifold injector to the in-cylinder injector is determined based on the engine speed and engine load. In the event of operation failure due to a malfunction of the in-cylinder injector or the fuel system that supplies fuel to the in-cylinder injector (hereinafter, referred to as high-pressure fuel supply system), fuel injection by the in-cylinder injector will be ceased. On the basis of the fail-safe faculty in such operation failure, it is possible to ensure travel by inhibiting fuel injection from the in-cylinder injector and fix the combustion mode at the uniform combustion mode to effect fuel injection from the intake manifold injector alone. However, in the case where the intake manifold injector is set to take an auxiliary role of the in-cylinder injector, fuel of a quantity corresponding to the intake air at the time of full opening of the throttle valve cannot be supplied, whereby the air-fuel ratio in the fail-safe mode will become lean. There may be the case where the torque is insufficient due to combustion defect. Japanese Patent Laying-Open No. 2000-145516 discloses an engine controlling device that can maintain the air-fuel ratio properly to obtain suitable driving power even during fuel injection control by the intake manifold injector alone in the fail-safe mode caused by operation failure of the in-cylinder injector. This engine controlling device includes an in-cylinder injector that directly injects fuel to the combustion chamber, an intake manifold injector that injects fuel to the intake system, and an electronic control type throttle valve. When the target fuel injection quantity set based on the engine operation state exceeds a predetermined injection quantity of the in-cylinder injector, the engine controlling device compensates for the insufficient quantity by fuel injection from the intake manifold injector. This engine controlling device also includes an abnormality determination unit determining abnormality of the in-cylinder injector and the high-pressure fuel supply system that supplies fuel to the in-cylinder injector, a target fuel correction unit comparing the maximum injection quantity of the intake manifold injector when abnormality is determined with the target fuel injection quantity to fix the target fuel injection quantity at the maximum injection quantity when the target fuel injection quantity exceeds the maximum injection quantity, a target intake air quantity correction unit calculating the target intake air quantity based on the target fuel injection quantity fixed at the maximum injection quantity and the target air-fuel ratio, and a throttle opening indication value calculation unit calculating the throttle opening indication value with respect to an electronic control type throttle valve based on the target intake air quantity. When abnormality is sensed in the in-cylinder injector and the high-pressure fuel supply system that supplies fuel to the in-cylinder injector in this engine controlling device, the maximum injection quantity of the intake manifold injector is compared with the target fuel injection quantity that is set based on the engine operation state. When the target fuel injection quantity exceeds the maximum injection quantity, the target fuel injection quantity is fixed at the maximum injection quantity. The target intake air quantity is calculated based on this fixed target fuel injection quantity and target air-fuel ratio. The throttle opening indication value is calculated with respect to the electronic control type throttle valve based on the calculated target intake air quantity. Accordingly, when abnormality is sensed in the in-cylinder injector system, fuel injection from the in-cylinder injector is inhibited, and fuel is to be injected from only the intake manifold injector. Based on the maximum injection quantity at this stage and the target air-fuel ratio, the target intake air quantity is calculated. The throttle opening indication value with respect to the electronic control type throttle valve is calculated based on the target intake air quantity. In the fail-safe mode caused by failure in the in-cylinder injector system, the throttle opening will open only to the level corresponding to the target air-fuel ratio no matter how hard the acceleration pedal is pushed down. Thus, the air-fuel ratio is maintained properly to obtain suitable driving power. It is to be noted that the engine controlling device disclosed in Japanese Patent Laying-Open No. 2000-145516 inhibits fuel injection from the in-cylinder injector to conduct fuel injection from only the intake manifold injector when malfunction occurs in the high-pressure fuel supply system. This induces the problem that deposits will be readily accumulated at the injection hole of the in-cylinder injector. The in-cylinder injector per se that was originally absent of failure, (for example, (1) even if failure originates from the high-pressure fuel supply system, or (2) failure originates from one of the plurality of in-cylinder injectors), will eventually malfunction due to the deposits accumulated at the injection hole of the in-cylinder injector. In the engine controlling device disclosed in Japanese Patent Laying-Open No. 2000-145516, the target fuel injection quantity is fixed at the maximum injection quantity level of the intake manifold injector, and fuel is injected from the intake manifold injector at the maximum injection level. Since no measures to suppress deposits accumulating at the injection hole of the in-cylinder injector has been taken into account, an in-cylinder injector that was originally absent of failure will eventually malfunction due to deposits accumulating at the injection hole of the in-cylinder injector. SUMMARY OF THE INVENTION An object of the present invention is to provide a control apparatus for an internal combustion engine in which a first fuel injection mechanism that injects fuel into a cylinder and a second fuel injection mechanism that injects fuel to an intake manifold partake in fuel injection, suppressing further failure of the first fuel injection mechanism when failure occurs at the first fuel injection mechanism side including a fuel supply system towards the first fuel injection mechanism. According to an aspect of the present invention, a control apparatus for an internal combustion engine controls the internal combustion engine that includes a first fuel injection mechanism injecting fuel into a cylinder, a second fuel injection mechanism injecting fuel into an intake manifold, a first fuel supply mechanism supplying fuel to the first fuel injection mechanism, and a second fuel supply mechanism supplying fuel to the first and second fuel injection mechanisms. The control apparatus includes a control unit controlling the first and second fuel injection mechanisms such that the first and second fuel injection mechanisms partake in fuel injection, including a state of injection from one of the first and second fuel injection mechanisms being ceased, a first abnormality determination unit determining presence of abnormality in the first fuel supply mechanism, and a second abnormality determination unit determining presence of abnormality in the first fuel injection mechanism. The control unit effects control such that fuel is injected from at least the first fuel injection mechanism using the second fuel supply mechanism when the first abnormality determination unit determines presence of abnormality in the first fuel supply system and the second abnormality determination unit does not determine presence of abnormality in the first fuel injection mechanism. In accordance with the present invention, the injection hole at the leading end of the first fuel injection mechanism (in-cylinder injector) identified as a fuel injection mechanism for injecting fuel into a cylinder of the internal combustion engine is located inside the combustion chamber. Attachment of deposits is promoted at a high temperature region and/or a high concentration region of nitrogen oxide (NOx). The desired quantity of fuel cannot be injected if such deposits are accumulated. Deposits are readily accumulated if fuel injection from the in-cylinder injector is ceased. In contrast, deposits are not readily accumulated when fuel is injected from the in-cylinder injector. Fuel is supplied to this in-cylinder injector from a first fuel supply mechanism that is a fuel supply system including a high-pressure pump injecting fuel at a compression stroke and a second fuel supply mechanism identified as a fuel supply system including a feed pump that supplies fuel from a fuel tank to the high-pressure pump. Conventionally, in the event of an error at the first fuel supply mechanism, fuel injection from the in-cylinder injector is inhibited, and fuel is injected out from the second fuel injection mechanism (intake manifold injector) alone. Therefore, an in-cylinder injector that was originally absent of failure would eventually malfunction due to the accumulating deposits that block the injection hole of the in-cylinder injector. In view of this problem, the control unit of the present invention effects control such that fuel is injected at an intake stroke, for example, from the first fuel injection mechanism using the second fuel supply mechanism. Therefore, the problem of accumulation of deposits at the injection hole of the in-cylinder injector can be obviated since fuel injection from the in-cylinder injector is not ceased. Thus, there is provided a control apparatus for an internal combustion engine in which the first fuel injection mechanism injecting fuel into the cylinder and the second fuel injection mechanism injecting fuel into an intake manifold partake in fuel injection, suppressing further failure of the first fuel injection mechanism when failure occurs at the first fuel injection mechanism side including the fuel supply system to the first fuel injection mechanism. Preferably, the control unit effects control to suppress fuel supply from the first fuel injection mechanism when the first abnormality determination unit determines presence of abnormality in the first fuel supply mechanism and the second abnormality determination unit determines presence of abnormality in the first fuel injection mechanism. Since fuel injection from the in-cylinder injector is not ceased unless determination is made of abnormality in the in-cylinder injector in the present invention, accumulation of deposits at the injection hole of the in-cylinder injector can be obviated. More preferably, the control apparatus further includes an adjustment unit adjusting a variable valve timing mechanism (VVT) provided at the internal combustion engine such that overlap of intake valves and exhaust valves is increased when the first abnormality determination unit determines presence of abnormality in the first fuel supply mechanism as compared to the case where determination is made of no abnormality in the first fuel supply mechanism. By increasing the overlap of the intake valves and exhaust valves in the present invention, the internal EGR (Exhaust Gas Recirculation) increases to reduce the combustion temperature, whereby generation of NOx is suppressed. When determination is made of abnormality in the first fuel supply mechanism such that fuel injection from the in-cylinder injector is to be ceased, the valve overlap is increased as set forth above to increase the internal EGR and reduce the combustion temperature, whereby generation of NOx is suppressed. By reducing the combustion temperature and suppressing NOx, accumulation of deposits at the injection hole of the in-cylinder injector can be suppressed. Further preferably, the control apparatus further includes an adjustment unit adjusting the ignition timing such that, when the first abnormality determination unit determines presence of abnormality in the first fuel supply mechanism, the ignition timing is retarded as compared to the case where determination is made of no abnormality in the first fuel supply mechanism. In accordance with the present invention, the ignition timing is retarded and the combustion temperature is reduced to suppress generation of NOx. By retarding the ignition timing as compared to the case where the ignition timing is set in the vicinity of MBT (Minimum spark advance for Best Torque) where the combustion pressure is highest and the combustion temperature is also high, the combustion pressure and the combustion temperature are reduced, allowing suppression of NOx generation. By such reduction in combustion temperature and suppression of NOx, accumulation of deposits at the injection hole of the in-cylinder injector can be suppressed. Further preferably, the control apparatus further includes a restriction unit restricting the output of the internal combustion engine such that deposits are not accumulated at the injection hole of the first fuel injection mechanism. When there is abnormality in the first fuel supply mechanism in the present invention, the output of the internal combustion engine is restricted to cause reduction of the temperature at the leading end of the in-cylinder injector (combustion temperature) and suppress NOx in order to obviate accumulation of deposits at the in-cylinder injector. Therefore, accumulation of deposits at the injection hole of the in-cylinder injector can be suppressed. Even in the case where fuel injection from the in-cylinder injector is ceased to attain a state in which deposits are apt to accumulate, fuel injection from the intake manifold injector is suppressed such that deposits are not accumulated at the injection hole of the in-cylinder injector. The problem of the injection hole of the in-cylinder injector being blocked by deposits can be obviated even after running in a mode in which the output of the internal combustion engine is restricted. Further preferably, the restriction unit modifies the restriction of the output of the internal combustion engine between an event of ceasing fuel injection from the first fuel injection mechanism and an event of conducting fuel injection from the first fuel injection mechanism using the second fuel supply mechanism to restrict the internal combustion engine output. In accordance with the present invention, in a fuel injection inhibited mode in which deposits are likely to be accumulated at the injection hole of the in-cylinder injector, output of the internal combustion engine, for example, is restricted stricter than when fuel injection is not ceased. The output of the internal combustion engine is restricted even in a state where deposits are likely to be accumulated at the injection hole. Thus, accumulation of deposits at the injection hole of the in-cylinder injector is prevented. Further preferably, the restriction unit modifies restriction of the output of the internal combustion engine to become stricter when fuel supply from the first fuel injection mechanism is ceased than in the case where fuel injection is conducted from the first fuel injection mechanism using the second fuel supply mechanism to restrict output of the internal combustion engine. In a fuel injection inhibited mode in which deposits will be accumulated more readily at the injection hole of the in-cylinder injector in the present invention, output of the internal combustion engine is further restricted than in the case where fuel injection is not ceased. The output of the internal combustion engine is suppressed even in a state where deposits are likely to be accumulated at the injection hole. Thus, accumulation of deposits at the injection hole of the in-cylinder injector is prevented. According to another aspect of the present invention, a control apparatus for an internal combustion engine controls the internal combustion engine including a first fuel injection mechanism injecting fuel into a cylinder and a second fuel injection mechanism injecting fuel into an intake manifold. The control apparatus includes an injection control unit controlling the first and second fuel injection mechanisms such that the first and second fuel injection mechanisms partake in fuel injection, including a state of injection from one of the first and second fuel injection mechanisms being ceased, a sense unit sensing that the first fuel injection mechanism cannot operate properly, and a control unit controlling the internal combustion engine such that the temperature in the cylinder of the internal combustion engine is reduced when the first fuel injection mechanism cannot operate properly. In accordance with the present invention, the injection hole at the leading end of the first fuel injection mechanism (in-cylinder injector) identified as a fuel injection mechanism for injecting fuel into a cylinder of the internal combustion engine is located inside the combustion chamber. Attachment of deposits is promoted at a high temperature region. The desired quantity of fuel cannot be injected if such deposits are accumulated. When fuel injection from the in-cylinder injector is suppressed and the temperature in the cylinder is high, deposits will be readily accumulated, promoting breakdown of the in-cylinder injector per se. When error occurs at the injection system of the in-cylinder injector or the fuel system of the in-cylinder injector, fuel injection from the in-cylinder injector is inhibited, or fuel was injected at the feed pressure. Both correspond to the case where the in-cylinder injector cannot operate properly. In such a case, cooling through the fuel is not effected since fuel is not injected from the in-cylinder injector. Therefore, an in-cylinder injector that was originally absent of failure will eventually malfunction due to accumulation of the deposits that block the injection hole of the in-cylinder injector or due to the high temperature. In such a case, the control unit controls the internal combustion engine such that the temperature in the cylinder of the internal combustion engine is reduced. Therefore, the problem of the in-cylinder injector attaining extremely high temperature can be obviated even in the case where fuel injection from the in-cylinder injector is ceased or in the case where injection can be conducted only at the feed pressure. Thus, there is provided a control apparatus for an internal combustion engine in which the first fuel injection mechanism injecting fuel into the cylinder and the second fuel injection mechanism injecting fuel into an intake manifold partake in fuel injection, suppressing further failure of the first fuel injection mechanism. Preferably, the control unit controls the internal combustion engine such that the temperature in the cylinder of the internal combustion engine is reduced, based on the temperature of the first fuel injection mechanism. In accordance with the present invention, the temperature of the first fuel injection mechanism (in-cylinder injector) is calculated (estimated and measured), and the internal combustion engine is controlled such that the temperature in the in-cylinder is reduced to avoid excessive increase of the temperature (avoid exceeding the threshold value). Thus, further failure of the in-cylinder injector is suppressed. Further preferably, the temperature of the first fuel injection mechanism is calculated based on the engine speed and intake air quantity of the internal combustion engine. In the present invention, the temperature of the in-cylinder injector is calculated higher as the engine speed and the intake air quantity of the internal combustion engine are higher, and calculated lower as the engine speed and the intake air quantity of the internal combustion engine are lower. Further preferably, the temperature of the first fuel injection mechanism is calculated by the temperature calculated based on the engine speed and the intake air quantity of the internal combustion engine, and the temperature variation factor. In accordance with the present invention, the basic temperature of the in-cylinder injector is calculated based on the engine speed and the intake air quantity of the internal combustion engine. The temperature of the in-cylinder injector is calculated taking into consideration the temperature variation factor that is the cause of reducing or increasing the temperature. Further preferably, the temperature variation factor is a correction temperature calculated based on at least one of the overlapping amount of the intake valves and exhaust valves and the retarded amount of the ignition timing. In accordance with the present invention, the internal EGR is increased to reduce the combustion temperature when the overlap of the intake valves and exhaust valves is great. The combustion temperature is reduced also in the case where the ignition timing is retarded. Taking into consideration the temperature variation factor that is the cause of reducing the temperature, the temperature of the in-cylinder injector is calculated. Further preferably, the control unit controls the internal combustion engine such that the temperature in the cylinder of the internal combustion engine is reduced by restricting the intake air quantity into the internal combustion engine. By restricting the intake air quantity into the internal combustion engine, the output of the internal combustion engine can be restricted to allow reduction of the temperature in the cylinder. Further preferably, the control unit controls the internal combustion engine such that the temperature in the cylinder of the internal combustion engine is reduced by restricting the engine speed of the internal combustion engine. In accordance with the present invention, the internal combustion engine output is restricted by restricting the engine speed of the internal combustion engine, allowing reduction of the temperature in the cylinder. Further preferably, the control apparatus has the temperature of the internal combustion engine reduced by the control unit when the temperature of the first fuel injection mechanism is higher than a predetermined temperature. In accordance with the present invention, the temperature in the cylinder of the internal combustion engine can be reduced when the temperature of the in-cylinder injector is high. Further preferably, the first fuel injection mechanism is an in-cylinder injector, and the second fuel injection mechanism is an intake manifold injector. In an internal combustion engine in which an in-cylinder injector identified as the first fuel injection mechanism and an intake manifold injector identified as the second fuel injection mechanism partake in fuel injection, fuel injection from the in-cylinder injector is not ceased even in the case where the first fuel supply mechanism (for example, high-pressure pump) that supplies fuel to the in-cylinder injector fails, or when one of the plurality of in-cylinder injectors fails. Therefore, a control apparatus for an internal combustion engine suppressing further failure of the in-cylinder injector can be provided. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a structure of an engine system under control of the control apparatus according to an embodiment of the present invention. FIG. 2 is a flow chart of a control structure of a program executed by an engine ECU that is the control apparatus according to an embodiment of the present invention. FIG. 3 represents the relationship between the fuel injection time and injection quantity. FIG. 4 represents the relationship between the engine speed and required injection quantity. FIG. 5 represents a DI ratio map corresponding to a warm state of an engine to which the control apparatus of an embodiment of the present invention is suitably adapted. FIG. 6 represents a DI ratio map corresponding to a cold state of an engine to which the control apparatus of an engine of the present invention is suitably adapted. FIG. 7 represents a DI ratio map corresponding to a warm state of an engine to which the control apparatus of an embodiment of the present invention is suitably adapted. FIG. 8 represents a DI ratio map corresponding to a cold state of an engine to which the control apparatus of an engine of the present invention is suitably adapted FIG. 9 is a flow chart of a control structure of a program executed by an engine ECU identified as the control apparatus according to a modification of an embodiment of the present invention. FIG. 10 represents a temperature tolerable region of an in-cylinder injector according to the modification of an embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described hereinafter with reference to the drawings. The same components have the same reference characters allotted, and their designation and function are also identical. Therefore, detailed description thereof will not be repeated. FIG. 1 is a schematic view of a structure of an engine system under control of an engine ECU (Electronic Control Unit) identified as a control apparatus for an internal combustion engine according to an embodiment of the present invention. Although an in-line 4-cylinder gasoline engine is indicated as the engine, the present invention is not limited to such an engine. As shown in FIG. 1 , the engine 10 includes four cylinders 112 , each connected to a common surge tank 30 via a corresponding intake manifold 20 . Surge tank 30 is connected via an intake duct 40 to an air cleaner 50 . An airflow meter 42 is arranged in intake duct 40 , and a throttle valve 70 driven by an electric motor 60 is also arranged in intake duct 40 . Throttle valve 70 has its degree of opening controlled based on an output signal of an engine ECU 300 , independently from an accelerator pedal 100 . Each cylinder 112 is connected to a common exhaust manifold 80 , which is connected to a three-way catalytic converter 90 . Each cylinder 112 is provided with an in-cylinder injector 110 for injecting fuel into the cylinder and an intake manifold injector 120 for injecting fuel into an intake port or/and an intake manifold. Injectors 110 and 120 are controlled based on output signals from engine ECU 300 . Further, in-cylinder injector 110 of each cylinder is connected to a common fuel delivery pipe 130 . Fuel delivery pipe 130 is connected to a high-pressure fuel pump 150 of an engine-driven type, via a check valve 140 that allows a flow in the direction toward fuel delivery pipe 130 . Although an internal combustion engine having two injectors separately provided is explained in the present embodiment, the present invention is not restricted to such an internal combustion engine. For example, the internal combustion engine may have one injector that can effect both in-cylinder injection and intake manifold injection. As shown in FIG. 1 , the discharge side of high-pressure fuel pump 150 is connected via an electromagnetic spill valve 152 to the intake side of high-pressure fuel pump 150 . As the degree of opening of electromagnetic spill valve 152 is smaller, the quantity of the fuel supplied from high-pressure fuel pump 150 into fuel delivery pipe 130 increases. When electromagnetic spill valve 152 is fully open, the fuel supply from high-pressure fuel pump 150 to fuel delivery pipe 130 is ceased. Electromagnetic spill valve 152 is controlled based on an output signal of engine ECU 300 . Specifically, the closing timing during a pressurized stroke of electromagnetic spill valve 152 provided at the pump intake side of high-pressure fuel pump 150 that applies pressure on the fuel by the vertical operation of a pump plunger through a cam attached to a cam shaft is feedback-controlled through engine ECU 300 using a fuel pressure sensor 400 provided at fuel delivery pipe 130 , whereby the fuel pressure in fuel delivery pipe 130 (fuel pressure) is controlled. In other words, by controlling electromagnetic spill valve 152 through engine ECU 300 , the quantity and pressure of fuel supplied from high-pressure fuel pump 150 to fuel delivery pipe 130 are controlled. Each intake manifold injector 120 is connected to a common fuel delivery pipe 160 at the low pressure side. Fuel delivery pipe 160 and high-pressure fuel pump 150 are connected to an electromotor driven type low-pressure fuel pump 180 via a common fuel pressure regulator 170 . Low-pressure fuel pump 180 is connected to fuel tank 200 via fuel filter 190 . When the fuel pressure of fuel ejected from low-pressure fuel pump 180 becomes higher than a predetermined set fuel pressure, fuel pressure regulator 170 returns a portion of the fuel output from low-pressure fuel pump 180 to fuel tank 200 . Accordingly, the fuel pressure supplied to intake manifold injector 120 and the fuel pressure supplied to high-pressure fuel pump 150 are prevented from becoming higher than the set fuel pressure. Engine ECU 300 is based on a digital computer, and includes a ROM (Read Only Memory) 320 , a RAM (Random Access Memory) 330 , a CPU (Central Processing Unit) 340 , an input port 350 , and an output port 360 connected to each other via a bidirectional bus 310 . Air flow meter 42 generates an output voltage in proportion to the intake air. The output voltage from air flow meter 42 is applied to input port 350 via an A/D converter 370 . A coolant temperature sensor 380 producing an output voltage in proportion to the engine coolant temperature is attached to engine 10 . The output voltage from coolant temperature sensor 380 is applied to input port 350 via an A/D converter 390 . A fuel pressure sensor 400 producing an output voltage in proportion to the fuel pressure in high pressure delivery pipe 130 is attached to high pressure delivery pipe 130 . The output voltage from fuel pressure sensor 400 is applied to input port 350 via an A/D converter 410 . An air-fuel ratio sensor 420 producing an output voltage in proportion to the oxygen concentration in the exhaust gas is attached to exhaust manifold 80 upstream of 3-way catalytic converter 90 . The output voltage from air-fuel ratio sensor 420 is applied to input port 350 via an A/D converter 430 . Air-fuel ratio sensor 420 in the engine system of the present embodiment is a full-range air-fuel ratio sensor (linear air-fuel sensor) producing an output voltage in proportion to the air-fuel ratio of air-fuel mixture burned at engine 10 . Air-fuel ratio sensor 420 may be an O 2 sensor that detects whether the air-fuel ratio of air-fuel mixture burned at engine 10 is rich or lean to the stoichiometric ratio in an on/off manner. An accelerator pedal position sensor 440 producing an output voltage in proportion to the pedal position of an accelerator pedal 100 is attached to accelerator pedal 100 . The output voltage from accelerator pedal position sensor 440 is applied to input port 350 via an A/D converter 450 . A revolution speed sensor 460 generating an output pulse representing the engine speed is connected to input port 350 . ROM 320 of engine ECU 300 stores the value of the fuel injection quantity set corresponding to an operation state, a correction value based on the engine coolant temperature, and the like that are mapped in advance based on the engine load factor and engine speed obtained through accelerator pedal position sensor 440 and revolution speed sensor 460 set forth above. A canister 230 that is a vessel for trapping fuel vapor dispelled from fuel tank 200 is connected to fuel tank 200 via a paper channel 260 . Canister 230 is further connected to a purge channel 280 to supply the fuel vapor trapped therein to the intake system of engine 10 . Purge channel 280 communicates with a purge port 290 that opens downstream of throttle valve 70 of intake duct 40 . As well known in the field of art, canister 230 is filled with an adsorbent (activated charcoal) adsorbing the fuel vapor. An air channel 270 to introduce air into canister 230 via a check valve during purging is formed in canister 230 . Further, a purge control valve 250 controlling the amount of purging is provided in purge channel 280 . The opening of purge control valve 250 is under duty control by engine ECU 300 , whereby the amount of fuel vapor that is to be purged in canister 230 , and in turn the quantity of fuel introduced into engine 10 (hereinafter, referred to as purge fuel quantity), is controlled. A control structure of a program executed by engine ECU 300 identified as the control apparatus of the present embodiment will be described with reference to FIG. 2 . The program in this flow chart is executed at a predetermined interval of time, or at a predetermined crank angle of engine 10 . At step (hereinafter, step abbreviated as S) 100 , engine ECU 300 determines whether abnormality in the high-pressure fuel system is sensed or not. For example, abnormality in the high-pressure fuel system is sensed when the engine-driven type high-pressure fuel pump fails so that the fuel pressure sensed by a fuel pressure sensor 400 is below a predetermined threshold value, or when the feedback control executed using fuel pressure sensor 400 is not proper. When abnormality in the high-pressure fuel system is sensed (YES at S 100 ), control proceeds to S 110 , otherwise (NO at S 100 ), control proceeds to S 200 . At S 110 , engine ECU 300 determines whether abnormality in in-cylinder injector 110 is sensed or not. For example, abnormality in in-cylinder injector 110 is sensend, caused by disconnection of a harness or the like that transmits a control signal to in-cylinder injector 110 . When abnormality in in-cylinder injector 110 is sensed (YES at S 110 ), control proceeds to S 140 , otherwise (NO at S 110 ), control proceeds to S 120 . At S 120 , engine ECU 300 injects fuel supplied by an electromotor driven type low-pressure fuel pump 180 (feed pump) out from in-cylinder injector 110 . Specifically, in-cylinder injector 110 injects fuel at the feed pressure. At S 130 , engine ECU 300 select criteria ( 1 ) as the standard employed for throttle restriction. Then, control proceeds to S 160 . At S 140 , engine ECU 300 inhibits fuel injection from in-cylinder injector 110 . Specifically, determination is made that in-cylinder injector 110 per se has failed, and injection is not conducted even at the feed pressure. At S 150 , engine ECU 300 selects criteria ( 2 ) as the standard used for throttle restriction. Then, control proceeds to S 160 . At S 160 , engine ECU 300 increases the overlap of the intake valves and exhaust valves by VVT. Accordingly, the internal EGR is increased to realize reduction in the combustion temperature and NOx. At S 170 , engine ECU 300 retards the ignition timing. Accordingly, reduction of the combustion temperature and NOx can be realized. At S 180 , engine ECU 300 restricts the opening of throttle valve 70 . This means that the output of engine 10 is restricted. Accordingly, the intake air quantity is reduced (on the basis of a stoichiometric state), and the fuel injection quantity is reduced. Increase of the temperature at the leading end of in-cylinder injector 110 and generation of NOx can be suppressed. Therefore, accumulation of deposits at the injection hole of in-cylinder injector 110 can be suppressed. The criterion employed at this stage is ( 1 ) or ( 2 ), which will be described afterwards. At S 200 , engine ECU 300 controls engine 10 so as to execute a normal operation. The operation of engine 10 under control of engine ECU 300 identified as the control apparatus for an internal combustion engine of the present embodiment based on the structure and flow chart set forth above will be described here with reference to FIGS. 3 and 4 . When high-pressure fuel pump 150 or a valve provided at a delivery system thereof, for example, fails (YES at S 100 ), determination is made whether abnormality in in-cylinder injector 110 is sensed or not. <In the Case of Abnormality in High-Pressure Fuel System, and Not in In-Cylinder Injector> When determination is made of no abnormality in in-cylinder injector 110 (NO at S 110 ), in-cylinder injector 110 injects fuel at the feed pressure (S 120 ). An example of the injected amount of fuel at this stage is shown in FIG. 3 . FIG. 3 represents the relationship between fuel injection time tau and the fuel injection quantity. Since in-cylinder injector 110 is not malfunctioning, in-cylinder injector 110 partakes in fuel injection. This corresponds to “in-cylinder injector=Qmin” in FIG. 3 . The remaining fuel is injected from intake manifold injector 120 with both the fuel supply system and injector functioning properly. The chain dotted line in FIG. 4 corresponds to a version of conventional art. Fuel injection from in-cylinder injector 110 is inhibited, and engine 10 is controlled within the region indicated by the chain dotted line (the lower side region of the chain dotted line) from intake manifold injector 120 alone. In the present embodiment, the standard of criteria ( 1 ) is selected when fuel is to be injected from in-cylinder injector 110 at the feed pressure, and the standard of criteria ( 2 ) is selected when in-cylinder injector 110 is ceased. In other words, engine 10 is controlled within a region (the lower side region of the solid line) indicated by either criteria depending upon whether fuel is injected from in-cylinder injector 110 or not. Criteria ( 1 ) and criteria ( 2 ) are independent of Qmin. The difference between criteria ( 1 ) and criteria ( 2 ) of FIG. 4 compensates for difference in the liability to clogging at the injector caused by in-cylinder injector 110 being ceased. In other words, criteria ( 1 ) includes margin with respect to injector clogging since in-cylinder injector 110 is operating for fuel injection, corresponding to the operation and fuel injection by in-cylinder injector 110 . This means that more fuel can be injected. Criteria ( 1 ) of FIG. 4 is selected (S 130 ), and control is effected such that the overlap of the intake valves and exhaust valves is increased by VVT (S 160 ). The ignition timing is retarded (S 170 ), and the output of engine 10 is restricted to correspond to the required injection quantity of the region at the side lower than the solid line indicating criteria ( 1 ) of FIG. 4 . Assuming that combustion is conducted at the stoichiometric state, the opening of throttle valve 70 is set smaller since a constant relationship is established between the fuel quantity and intake air quantity. By increasing the overlap of the intake valves and exhaust valves, the internal EGR is increased to lower the combustion temperature, whereby generation of NOx is suppressed. By retarding the ignition timing, the combustion temperature can be reduced to suppress generation of NOx. By reduction in combustion temperature and suppression of NOx, accumulation of deposits at the injection hole of the in-cylinder injector can be suppressed. As indicated by the chain dotted line in FIG. 4 corresponding to the conventional case, restriction of fuel injection (required injection quantity) from intake manifold injector 120 did not take deposits at in-cylinder injector 110 into account. When fuel is injected at the feed pressure using in-cylinder injector 110 in the present embodiment, engine 10 is controlled within the range of criteria ( 1 ) corresponding to the region where the required injection quantity is more restricted with respect to the engine speed than in the conventional case. Accordingly, the temperature at the leading end of the in-cylinder injector (combustion temperature) is reduced to suppress NOx, whereby accumulation of deposits at the injection hole of the in-cylinder injector can be suppressed. <In the Case of Abnormality in Both High-Pressure Fuel System and In-Cylinder Injector> When determination is made of abnormality in in-cylinder injector 110 (YES at S 110 ), fuel injection from in-cylinder injector 110 is ceased (S 140 ). Criteria ( 2 ) of FIG. 4 is selected (S 150 ). Control is effected such that the overlap of the intake valves and exhaust valves increases by VVT (S 160 ). The ignition timing is retarded (S 170 ). The output of engine 10 is restricted to correspond to the required injection quantity of the region at the side lower than the solid line indicating criteria ( 2 ) of FIG. 4 . Assuming that combustion is conducted at the stoichiometric state as mentioned above, the opening of throttle valve 70 is set smaller since a constant relationship is established between the fuel quantity and intake air quantity. Particularly in the case where in-cylinder injector 110 is ceased, criteria ( 2 ) that has a stricter restriction than criteria ( 1 ) corresponding to the case where fuel is injected at the feed pressure from in-cylinder injector 110 is selected. Thus, the required injection quanity is further restricted, as shown in FIG. 4 . By further restricting the amount of fuel injected from intake manifold injector 120 , accumulation of deposits can be suppressed even in the state where deposits are apt to be more readily accumulated at the injection hole due to inhibition of fuel injection from in-cylinder injector 110 . Thus, even when error occurs at the fuel supply system that supplies fuel to the in-cylinder injector, fuel can be supplied to the in-cylinder injector for injection by the feed pump as long as the in-cylinder injector is proper. Accordingly, accumulation of deposits at the injection hole of the in-cylinder injector can be obviated. At this stage, the overlap of the intake valves and exhaust valves is increased by VVT, and the ignition timing is retarded, whereby combustion temperature is reduced and generation of NOx is suppressed to obviate accumulation of deposits. Additionally, the required fuel quantity is reduced based on criteria ( 1 ) to reduce the combustion temperature and suppress generation of NOx. Thus, accumulation of deposits is suppressed. Further, fuel injection from the in-cylinder injector is ceased if abnormality is detected therein in addition to occurrence of an error at the fuel supply system that supplies fuel to the in-cylinder injector. In this case, criteria ( 2 ) with a restriction stricter than criteria ( 1 ) is employed to further reduce the required fuel quantity, whereby the combustion temperature is reduced and generation of NOx is suppressed. Accordingly, accumulation of deposits at the in-cylinder injector that is inhibited of fuel injection can be suppressed. <Engine ( 1 ) to Which Present Control Apparatus can be Suitably Applied> An engine ( 1 ) to which the control apparatus of the present embodiment is suitably adapted will be described hereinafter. Referring to FIGS. 5 and 6 , maps indicating a fuel injection ratio (hereinafter, also referred to as DI ratio (r)) between in-cylinder injector 110 and intake manifold injector 120 , identified as information associated with an operation state of engine 10 , will now be described. The maps are stored in an ROM 320 of an engine ECU 300 . FIG. 5 is the map for a warm state of engine 10 , and FIG. 6 is the map for a cold state of engine 10 . In the maps of FIGS. 5 and 6 , the fuel injection ratio of in-cylinder injector 110 is expressed in percentage as the DI ratio r, wherein the engine speed of engine 10 is plotted along the horizontal axis and the load factor is plotted along the vertical axis. As shown in FIGS. 5 and 6 , the DI ratio r is set for each operation region that is determined by the engine speed and the load factor of engine 10 . “DI RATIO r=100%” represents the region where fuel injection is carried out from in-cylinder injector 110 alone, and “DI RATIO r=0%” represents the region where fuel injection is carried out from intake manifold injector 120 alone. “DI RATIO r≠0%”, “DI RATIO r≠100%” and “0%<DI RATIO r<100%” each represent the region where in-cylinder injector 110 and intake manifold injector 120 partake in fuel injection. Generally, in-cylinder injector 110 contributes to an increase of power performance, whereas intake manifold injector 120 contributes to uniformity of the air-fuel mixture. These two types of injectors having different characteristics are appropriately selected depending on the engine speed and the load factor of engine 10 , so that only homogeneous combustion is conducted in the normal operation state of engine 10 (for example, a catalyst warm-up state during idling is one example of an abnormal operation state). Further, as shown in FIGS. 5 and 6 , the DI ratio r of in-cylinder injector 110 and intake manifold injector 120 is defined individually in the maps for the warm state and the cold state of the engine. The maps are configured to indicate different control regions of in-cylinder injector 110 and intake manifold injector 120 as the temperature of engine 10 changes. When the temperature of engine 10 detected is equal to or higher than a predetermined temperature threshold value, the map for the warm state shown in FIG. 5 is selected; otherwise, the map for the cold state shown in FIG. 6 is selected. In-cylinder injector 110 and/or intake manifold injector 120 are controlled based on the engine speed and the load factor of engine 10 in accordance with the selected map. The engine speed and the load factor of engine 10 set in FIGS. 5 and 6 will now be described. In FIG. 5 , NE( 1 ) is set to 2500 rpm to 2700 rpm, KL( 1 ) is set to 30% to 50%, and KL( 2 ) is set to 60% to 90%. In FIG. 6 , NE( 3 ) is set to 2900 rpm to 3100 rpm. That is, NE( 1 )<NE( 3 ). NE( 2 ) in FIG. 5 as well as KL( 3 ) and KL( 4 ) in FIG. 6 are also set appropriately. In comparison between FIG. 5 and FIG. 6 , NE( 3 ) of the map for the cold state shown in FIG. 6 is greater than NE( 1 ) of the map for the warm state shown in FIG. 5 . This shows that, as the temperature of engine 10 becomes lower, the control region of intake manifold injector 120 is expanded to include the region of higher engine speed. That is, in the case where engine 10 is cold, deposits are unlikely to accumulate in the injection hole of in-cylinder injector 110 (even if fuel is not injected from in-cylinder injector 110 ). Thus, the region where fuel injection is to be carried out using intake manifold injector 120 can be expanded, whereby homogeneity is improved. In comparison between FIG. 5 and FIG. 6 , “DI RATIO r=100%” in the region where the engine speed of engine 10 is NE( 1 ) or higher in the map for the warm state, and in the region where the engine speed is NE( 3 ) or higher in the map for the cold state. In terms of load factor, “DI RATIO r=100%” in the region where the load factor is Kl( 2 ) or greater in the map for the warm state, and in the region where the load factor is KL( 4 ) or greater in the map for the cold state. This means that in-cylinder injector 110 alone is used in the region of a predetermined high engine speed, and in the region of a predetermined high engine load. That is, in the high speed region or the high load region, even if fuel injection is carried out through in-cylinder injector 110 alone, the engine speed and the load of engine 10 are so high and the intake air quantity so sufficient that it is readily possibly to obtain a homogeneous air-fuel mixture using only in-cylinder injector 110 . In this manner, the fuel injected from in-cylinder injector 110 is atomized within the combustion chamber involving latent heat of vaporization (or, absorbing heat from the combustion chamber). Thus, the temperature of the air-fuel mixture is decrease at the compression end, so that the anti-knocking performance is improved. Further, since the temperature within the combustion chamber is decreased, intake efficiency improves, leading to high power. In the map for the warm state in FIG. 5 , fuel injection is also carried out using in-cylinder injector 110 alone when the load factor is KL( 1 ) or less. This shows that in-cylinder injector 110 alone is used in a predetermined low-load region when the temperature of engine 10 is high. When engine 10 is in the warm state, deposits are likely to accumulate in the injection hole of in-cylinder injector 110 . However, when fuel injection is carried out using in-cylinder injector 110 , the temperature of the injection hole can be lowered, in which case accumulation of deposits is prevented. Further, clogging at in-cylinder injector 110 may be prevented while ensuring the minimum fuel injection quantity thereof Thus, in-cylinder injector 110 solely is used in the relevant region. In comparison between FIG. 5 and FIG. 6 , the region of “DI RATIO r=0%” is present only in the map for the cold state of FIG. 6 . This shows that fuel injection is carried out through intake manifold injector 120 alone in a predetermined low-load region (KL( 3 ) or less) when the temperature of engine 10 is low. When engine 10 is cold and low in load and the intake air quantity is small, the fuel is less susceptible to atomization. In such a region, it is difficult to ensure favorable combustion with the fuel injection from in-cylinder injector 110 . Further, particularly in the low-load and low-speed region, high power using in-cylinder injector 110 is unnecessary. Accordingly, fuel injection is carried out through intake manifold injector 120 alone, without using in-cylinder injector 110 , in the relevant region. Further, in an operation other than the normal operation, or, in the catalyst warm-up state during idling of engine 10 (an abnormal operation state), in-cylinder injector 110 is controlled such that stratified charge combustion is effected. By causing the stratified charge combustion only during the catalyst warm-up operation, warming up of the catalyst is promoted to improve exhaust emission. <Engine ( 2 ) to Which Present Control Apparatus is Suitably Adapted> An engine ( 2 ) to which the control apparatus of the present embodiment is suitably adapted will be described hereinafter. In the following description of the engine ( 2 ), the configurations similar to those of the engine ( 1 ) will not be repeated. Referring to FIGS. 7 and 8 , maps indicating the fuel injection ratio between in-cylinder injector 110 and intake manifold injector 120 identified as information associated with the operation state of engine 10 will be described. The maps are stored in ROM 320 of an engine ECU 300 . FIG. 7 is the map for the warm state of engine 10 , and FIG. 8 is the map for the cold state of engine 10 . FIGS. 7 and 8 differ from FIGS. 5 and 6 in the following points. “DI RATIO r=100%” holds in the region where the engine speed of engine 10 is equal to or higher than NE( 1 ) in the map for the warm state, and in the region where the engine speed is NE( 3 ) or higher in the map for the cold state. Further, “DI RATIO r=100%” holds in the region, excluding the low-speed region, where the load factor is KL( 2 ) or greater in the map for the warm state, and in the region, excluding the low-speed region, where the load factor is KL( 4 ) or greater in the map for the cold state. This means that fuel injection is carried out through in-cylinder injector 110 alone in the region where the engine speed is at a predetermined high level, and that fuel injection is often carried out through in-cylinder injector 110 alone in the region where the engine load is at a predetermined high level. However, in the low-speed and high-load region, mixing of an air-fuel mixture produced by the fuel injected from in-cylinder injector 110 is poor, and such inhomogeneous air-fuel mixture within the combustion chamber may lead to unstable combustion. Thus, the fuel injection ratio of in-cylinder injector 110 is increased as the engine speed increases where such a problem is unlikely to occur, whereas the fuel injection ratio of in-cylinder injector 110 is decreased as the engine load increases where such a problem is likely to occur. These changes in the DI ratio r are shown by crisscross arrows in FIGS. 7 and 8 . In this manner, variation in output torque of the engine attributable to the unstable combustion can be suppressed. It is noted that these measures are substantially equivalent to the measures to decrease the fuel injection ratio of in-cylinder injector 110 in connection with the state of the engine moving towards the predetermined low speed region, or to increase the fuel injection ratio of in-cylinder injector 110 in connection with the engine state moving towards the predetermined low load region. Further, in a region other than the region set forth above (indicated by the crisscross arrows in FIGS. 7 and 8 ) and where fuel injection is carried out using only in-cylinder injector 110 (on the high speed side and on the low load side), the air-fuel mixture can be readily set homogeneous even when the fuel injection is carried out using only in-cylinder injector 110 . In this case, the fuel injected from in-cylinder injector 110 is atomized within the combustion chamber involving latent heat of vaporization (by absorbing heat from the combustion chamber). Accordingly, the temperature of the air-fuel mixture is decreased at the compression end, whereby the antiknock performance is improved. Further, with the decreased temperature of the combustion chamber, intake efficiency improves, leading to high power output. In the engine described in conjunction with FIGS. 5–8 , the fuel injection timing of in-cylinder injector 110 is preferably achieved in the compression stroke, as will be described hereinafter. When the fuel injection timing of in-cylinder injector 110 is set in the compression stroke, the air-fuel mixture is cooled by the fuel injection while the temperature in the cylinder is relatively high. Accordingly, the cooling effect is enhanced to improve the antiknock performance. Further, when the fuel injection timing of in-cylinder injector 110 is set in the compression stroke, the time required starting from fuel injection to ignition is short, which ensures strong penetration of the injected fuel. Therefore, the combustion rate is increased. The improvement in antiknock performance and the increase in combustion rate can prevent variation in combustion, and thus, combustion stability is improved. <Modification of Present Embodiment> A control apparatus according to a modification of the present invention will be described here. The structure of the engine system under control of ECU 300 of the control apparatus of the present modification is similar to that shown in FIG. 1 . Therefore, detailed description thereof will not be repeated. The present modification is characterized in that the operation region of engine 10 is restricted based on the temperature of in-cylinder injector 110 . A control structure of a program executed by engine ECU 300 identified as the control apparatus of the present modification will be described with reference to FIG. 9 . The program of this flow chart is executed at a predetermined interval of time, or at a predetermined crank angle of engine 10 . At S 300 , engine ECU 300 determines whether abnormality in the high-pressure fuel system is sensed or not. When abnormality in the high-pressure fuel system is sensed (YES at S 300 ), control proceeds to S 340 , otherwise (NO at S 300 ), control proceeds to S 310 . At S 310 , engine ECU 300 determines whether abnormality in in-cylinder injector 110 is sensed or not. When abnormality of in-cylinder injector 110 is sensed (YES at S 310 ), control proceeds to S 340 , otherwise (NO at S 310 ), control proceeds to S 320 . At S 320 , engine ECU 300 determines whether abnormality of fuel pressure is sensed or not. For example, abnormality of fuel pressure is sensed when in-cylinder injector 110 cannot inject fuel even at the feed pressure. Upon sensing abnormality of fuel pressure (YES at S 320 ), control proceeds to S 340 , otherwise (NO at S 320 ), control proceeds to S 330 . At S 330 , engine ECU 300 determines whether the wiring of the high pressure system is disconnected (for example, disconnection of the harness or the like that transmits a control signal to in-cylinder injector 110 ). When determination is made that the wiring of the high pressure system is disconnected (YES at S 330 ), control proceeds to S 340 , otherwise (NO at S 330 ), control proceeds to S 500 . At S 340 , engine ECU 300 inhibits fuel injection from in-cylinder injector 110 . At S 350 , engine ECU 300 calculates the basic temperature T ( 0 ) of in-cylinder injector 110 based on engine speed NE and the opening of throttle valve 70 . This basic temperature T ( 0 ) is the estimated temperature of in-cylinder injector 110 when correction that will be described afterwards is not taken into account. At S 360 , engine ECU 300 calculates a temperature correction value T ( 1 ) based on the ignition retarded amount, and VVT overlap. When the overlap of the intake valves and exhaust valves by VVT is great, the internal EGR is increased, and combustion temperature is reduced. When the ignition timing is retarded, the combustion temperature is reduced. Therefore, when the overlap of VVT or the ignition timing is modified (retarded) towards reduction of the combustion temperature, T ( 1 ) becomes negative. At S 370 , engine ECU 300 determines whether the value of adding temperature correction value T ( 1 ) to basic temperature T ( 0 ) is equal to or greater than a threshold value. When the value is equal to or greater than the threshold value (YES at S 370 ), control proceeds to S 400 , otherwise (NO at S 370 ), control proceeds to S 500 . The value of (basic temperature T ( 0 )+temperature correction value T ( 1 )) is eventually the estimated temperature of in-cylinder injector 110 . When this estimated temperature is equal to or greater than a threshold value corresponding to the tolerable temperature to avoid failure caused by thermal factors when a proper in-cylinder injector 110 is ceased, the output of engine 10 is restricted to avoid any further increase in temperature. The failure at this stage is attributed to inhibition of cooling of in-cylinder injector 110 that was generally effected by fuel injection since fuel injection from in-cylinder injector 110 is ceased. Such failure includes clogging of the injection hole caused by accumulation of deposits in the proximity of the injection hole, excess of the heat-resisting temperature of in-cylinder injector 110 itself, and the like. An actually measured temperature of in-cylinder injector 110 (temperature at the leading end) may be employed instead of the estimated temperature of in-cylinder injector 110 . At S 400 , engine ECU 300 restricts the opening of throttle valve 70 . This implies that the output of engine 10 is restricted. Accordingly, the intake air quantity is reduced, and output of engine 10 is restricted. This prevents excessive increase of the combustion temperature. Therefore, increase of temperature at the leading end of in-cylinder injector 110 can be suppressed, and induction of secondary failure caused by accumulation of deposits at the injection hole of in-cylinder injector 110 can be obviated. At S 500 , engine ECU 300 controls throttle valve 70 in a normal manner. The operation of engine 10 under control of engine ECU 300 identified as the control apparatus for an internal combustion engine according to the present modification based on the structure and flow chart set forth above will be described here. When the high-pressure fuel system fails (YES at S 300 ), when at least one of in-cylinder injectors 110 fails (YES at S 310 ), when abnormality of the fuel pressure is sensed (YES at S 320 ), or when the wiring of the high pressure system is disconnected (YES at S 330 ), fuel injection from in-cylinder injector 110 is ceased (S 340 ). The basic temperature T ( 0 ) of in-cylinder injector 110 is calculated on the basis of engine speed NE and the throttle opening. A temperature correction value T ( 1 ) is calculated to take into consideration the factors of increase or decrease of temperature with respect to basic temperature T ( 0 ) (S 360 ). Temperature correction value T ( 1 ) is added to basic temperature T ( 0 ) to calculate the estimated temperature of in-cylinder injector 110 . Since secondary failure of in-cylinder injector 110 caused by thermal factors may be induced if the estimated temperature is as high as the threshold value, the opening of throttle valve 70 is restricted to restrict the output of engine 10 . Accordingly, excessive increase in temperature of in-cylinder injector 110 is obviated to suppress secondary failure of in-cylinder injector 110 . When in-cylinder injector 110 is ceased in the present modification, secondary failure of in-cylinder injector 110 can be obviated as will be set forth below in addition to restricting the opening of throttle valve 70 . As shown in FIG. 10 , the temperature tolerable range for in-cylinder injector 110 is determined in advance based on engine speed NE and the load factor. The engine speed and the like are controlled such that engine 10 is operated within this region. Although the present modification has been described in which in-cylinder injector 110 is ceased, the control apparatus of the present modification can be applied even in the case where in-cylinder injector 110 injects fuel at the feed pressure, as described with reference to FIG. 2 . The engine described with reference to FIGS. 5–8 is suitable for application of the control apparatus of the present modification. Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.

An engine ECU executes a program including the steps of: determining presence of abnormality in a high-pressure fuel system; when abnormality is sensed in the high-pressure fuel system, and not in an in-cylinder injector, injecting fuel from the in-cylinder injector at the feed pressure; selecting criteria ( 1 ) that is the restriction standard for a more gentle output restriction of the engine; when abnormality is sensed in the high-pressure fuel system and in the in-cylinder injector, ceasing the in-cylinder injector; selecting criteria ( 2 ) that is the restriction standard for a stricter output restriction of the engine; increasing the VVT overlap; retarding the ignition timing; and restricting the throttle opening according to the selected criteria.

DESCRIPTION 1. Technical Field This invention relates to radiation curable compositions which are particularly useful in radiation curable coating compositions, and in particular radiation curable coatings which contain a magnetic powder to prepare a magnetic coating composition suitable for the production of magnetic recording media, such as magnetic tapes and magnetic discs. 2. Background Art In general, magnetic recording media are produced by applying a magnetic coating material composed of a magnetic powder, a polymer, a solvent and various additives to a substrate such as a polyester film to produce a magnetic layer. Recently, there have been known processes which comprise preparing a magnetic coating material by mixing a radiation-curable polymer having acrylic double bonds with a magnetic powder, a solvent and the like to prepare a magnetic coating material, applying the magnetic coating material to a substrate and curing the coating by radiation (See, for example, Japanese Laid-Open Patent Publication No. 25230/1981, No. 124119/1981 and No. 77433/1975). Such magnetic coating materials prepared by mixing and dispersing a magnetic powder into a radiation-curable polymer are expected to be effective for the improvement of the pot life of the magnetic coating material, reduction in the amount of solvent used, and simplification of the production process of magnetic recording media, saving of the energy consumed for curing the magnetic coating, etc. However, magnetic coating materials prepared using conventional radiation-curable polymers have the problem of insufficient dispersion of the magnetic powder due to the poor affinity between the magnetic powder and the polymer. Therefore, magnetic recording media produced by using such a magnetic coating material are unsatisfactory in the electromagnetic conversion characteristics and their practical durability is only comparable to that of the magnetic recording media produced by using the hitherto known magnetic coating materials containing a thermosetting resin. Accordingly, an object of the present invention is to provide a coating material for use in radiation curing which has good properties as a radiation-curable coating material and high affinity for magnetic powders, thereby ensuring sufficient dispersion of the magnetic powder therein and, when used as a magnetic coating material, yields magnetic recording media with good practical durability. The present invention provides a coating material for use in radiation curing comprising a polymer having a molecular weight of 2,000 to 100,000 and having: (A) at least one structural unit selected from the structural units represented by the following general formulas (I), (II) and (III) on both ends of its molecule, (B) at least one structural unit selected from the structural units represented by the following general formulas (IV), (V), (VI) and (VII), (C) a structural unit represented by the following general formula (VIII), (D) a structural unit represented by the following general formula (IX), and optionally (E) at least one structural unit selected from the structural units represented by the following general formulas (X) and (XI). wherein the structural units of the general formulas (I) to (XI) are linked by at least one linkage selected from urethane linkage ##STR1## urea linkage ##STR2## N-substituted urea linkage ##STR3## wherein R represents a C 1 to C 8 aliphatic, alicyclic or aromatic group which may be substituted or unsubstituted by hydroxyl groups or the like), the amide linkage ##STR4## and the ester linkage ##STR5## CH.sub.2 ═C(R.sub.1)-- (I) wherein R 1 represents a hydrogen atom or a methyl group. ##STR6## wherein R 1 is as defined in the general formula (I), and R 2 represents a C 2 to C 8 , preferably C 2 to C 3 , alkylene group such as ethylene, propylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene and octamethylene group. ##STR7## wherein R 1 is as defined in the general formula (I). --(R.sub.3 O).sub.k --(R.sub.48 O).sub.l --R.sub.4 O).sub.m ].sub.n R.sub.3 -- (IV) or --(R.sub.3 O).sub.k --(R.sub.48 O).sub.l --R.sub.4 O).sub.m ].sub.n R.sub.4 -- wherein R 3 and R 4 , which may be identical or different, represent a C 2 to C 6 , preferably C 2 to C 4 alkylene group such as ethylene, propylene, tetramethylene, pentamethylene and hexamethylene group; R 48 represents a C 13 to C 18 , preferably C 13 to C 15 , divalent organic group having an aromatic group of the structural formula: ##STR8## (wherein R' and R", which may be identical or different, represent an alkyl group such as methyl, ethyl and butyl group); k and m are each an integer of 0 to 50, preferably 5 to 20, l is an integer of 0 to 50, preferably 0 to 10, provided that k, l and m are not 0 simultaneously, and n is an integer of 0 to 50, preferably 1 to 10. ##STR9## wherein R 3 and R 4 are as defined in the general formula (IV); R 5 represents a divalent aliphatic, alicyclic or aromatic hydrocarbon group with 2 to 8 carbon atoms having the structural formula: ##STR10## and the like; l and m are as defined in the general formula (IV); and p is an integer of 1 to 50, preferably 1 to 20. ##STR11## wherein R 2 is as defined in the general formula (II); R 6 , R 7 , R 8 and R 9 , which may be identical or different, represent a hydrogen atom or a C 1 to C 8 aliphatic, alicyclic or aromatic group such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl, cyclohexyl and the like, preferably a C 1 to C 3 alkyl group; r and s are an integer of 1 to 50, preferably 5 to 20; and q is an integer of 1 to 20, preferably 5 to 20. --R.sub.10 -- (VII) wherein R 10 represents a divalent aliphatic, alicyclic or aromatic group with 2 to 40, preferably 2 to 20, carbon atoms such as ethylene, propylene, tetramethylene, hexamethylene, phenylene, cyclohexylene, methylenebisphenylene, methylenebiscyclohexylene and the groups of the structural formulas: ##STR12## and the like. ##STR13## wherein R 11 represents a trivalent aliphatic, alicyclic or aromatic group having 2 to 20, preferably 2 to 17, carbon atoms such as ##STR14## (wherein R 1 is as defined in the general formula (I); and R 16 and R 17 , which may be identical or different, represent a hydrogen atom or a C 1 to C 8 , preferably C 1 to C 3 , alkyl group such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl group), ##STR15## and the like, and these aliphatic, alicyclic and aromatic groups, as exemplified above, may have --O--, ##STR16## (wherein R 12 represents a hydrogen atom or a C 1 to C 8 aliphatic, alicyclic or aromatic group such as methyl, ethyl, propyl, butyl, amyl, phenyl, benzyl, cyclohexyl, cyclopentyl and the like which may be substituted by a hydroxyl group or the like), ##STR17## or --SO 2 -- in their structure; and M represents a hydrogen atom, ammonium group, alkali metal atom or alkaline earth metal atom. ##STR18## wherein R 1 is as defined in the general formula (I), and R 13 represents a divalent aliphatic, alicyclic or aromatic group with or without substituent groups such as ##STR19## (wherein n represents an integer of 0 to 20, and X represents a fluorine, chlorine or bromine atom), and these aliphatic, alicyclic and aromatic groups, as exemplified above, may have --O--, ##STR20## (wherein R 14 represents a hydrogen atom or a C 1 to C 8 aliphatic, alicyclic or aromatic group such as methyl, ethyl, propyl, butyl, amyl, phenyl, benzyl, cyclohexyl, cyclopentyl and the like which may be substituted by hydroxyl groups or the like) in their molecule. ##STR21## wherein R 15 represents a tetravalent aliphatic, alicyclic or aromatic group having 2 to 40, preferably 2 to 20, more preferably 2 to 13, carbon atoms such as those represented by the structural formulas: ##STR22## wherein R 13 is as defined in the general formula (IX). Three exemplary processes for preparing the polymer used in the coating material for use in radiation curing of the invention will now be described. PROCESS A A polymer used in the invention can be prepared by reacting at least one bifunctional compound selected from diols and diamines with a compound having in its molecule the structural unit of the general formula (IX) and two hydroxyl groups (hereinafter referred to as "Specified Hydroxyl Compound") and a diisocyanate compound to produce a polymer having isocyanate groups on the ends of its molecule and linked by urethane linkages and, optionally, urea linkages, then reacting part of the isocyanate groups of the polymer with an acrylic or methacrylic compound having a hydroxyl group to combine the reactants by urethane linkages, and subsequently reacting the residual isocyanate groups of the resultant reaction product with a compound having in its molecule the structural unit of the general formula (VIII) and two functional groups selected from hydroxyl groups, primary amino groups and secondary amino groups (hereinafter referred to as "Specified Sulfonic Acid Compound") and, optionally, with a compound having in its molecule the structural unit of the general formula (X) and two functional groups selected from hydroxyl groups, primary amino groups and secondary amino groups (hereinafter referred to as "Specified Carboxyl Compound") and/or a compound having in its molecule the structural unit of the general formula (XI) and two secondary amino groups (hereinafter referred to as "Specified Amine Adduct") to combine the reactants via urethane linkages, urea linkages or N-substituted urea linkages. PROCESS B A polymer used in the invention can be prepared by reacting at least one bifunctional compound selected from diols and diamines with a Specified Hydroxyl Compound and a diisocyanate compound to produce a polymer having two functional groups selected from hydroxyl groups, primary amino groups and secondary amino groups on the ends of its molecule and linked by urethane linkages and, optionally, urea linkages, then reacting the polymer with a dicarboxyl compound having the structural unit of the general formula (XIII) in its molecule or an acid anhydride thereof and, optionally, with a tetracarboxylic acid dianhydride having the structure of R 15 of the general formula (X) to combine the reactants via ester linkages or amide linkages, thereby lengthening the chain of the polymer, and subsequently reacting the terminal hydroxyl, primary amino and/or secondary amino groups of the chain-lengthened polymer with an acrylic or methacrylic compound having a carboxyl, epoxy or acid halide group to combine the reactants via ester linkages or amide linkages. PROCESS C A polymer used in the invention can be prepared by reacting a Specified Sulfonic Acid Compound and optionally a Specified Carboxyl Compound, at least one bifunctional compound selected from diols and diamines, a Specified Hydroxyl Compound, and a diisocyanate compound to produce a polymer linked by urethane linkages and, optionally, urea linkages, then reacting part or all of the residual isocyanate groups of the polymer with an acrylic or methacrylic compound having a hydroxyl group to combine the reactants via urethane linkages, and, where the reaction product has residual isocyanate groups, reacting the residual isocyanate groups with a Specified Amine Adduct to combine the reactants via urea linkages or N-substituted urea linkages. The diols used in the above processes include, for example, polyester diols, polyether diols, polycaprolactam diols, polycarbonate diols and the like. The polyester diols include, for example, the polyester diols prepared by reacting a polyvalent alcohol such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexanediol, neopentyl glycol and 1,4-cyclohexanedimethanol with a polybasic acid such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adiptic acid and sebacic acid. The polyether diols include, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, alkylene oxide adducts of bisphenol and the like. The diamines include, for example, diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane and the like; diamines containing hetero-atoms; polyetherdiamine, etc. The diisocyanate compounds include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, 4,4'-biphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylene bis(4-cyclohexyl isocyanate) and the like. The acrylic or methacrylic compounds having hydroxyl groups include, for example, 2-hydroxyethyl acrylate and methacrylate, 2-hydroxypropyl acrylate and methacrylate, 2-hydroxyoctyl acrylate and methacrylate, pentaerythritol triacrylate and trimethacrylate, glycerol diacrylate and dimethacrylate, dipentaerythritol monohydroxy pentaacrylate and pentamethacrylate and the like. The acrylic or methacrylic compounds having carboxyl groups include acrylic acid, methacrylic acid and the like. The acrylic or methacrylic compounds having epoxy groups include glycidyl esters of acrylic acid and methacrylic acid and the like. The acrylic or methacrylic compounds having acid halide groups include acrylic acid halides and methacrylic acid halides such as acrylic acid chloride, methacrylic acid chloride, acrylic acid bromide, methacrylic acid bromide, and the like. The tetracarboxylic acid dianhydrides having the structural unit of R 15 in the general formula (X) include, for example, aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,4,5-pentanetetracarboxylic acid dianhydride and the like, alicyclic tetracarboxylic acid dianhydrides such as 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride and the like, the aromatic tetracarboxylic acid dianhydrides such as pyromellitic dianhydride, benzophenonetetracarboxylic acid dianhydride and the like. The dicarboxyl compounds or acid anhydrides thereof having the structural unit of the general formula (VIII) in its molecule include sulfosuccinic acid, sulfophthalic acid, sulfophthalic acid anhydride, sulfoterephthalic acid, sulfoisophthalic acid, sulfopropoxyisophthalic acid, sulfoethoxyisophthalic acid, sodium salts, potassium salts, ammonium salts, lithium salts, calcium salts, magnesium salts, barium salts and strontium salts of these compounds and the like. The specified carboxyl compounds can be synthesized by reacting one mole of at least one compound selected from diols, diamines and aminoalcohols with less than one mole of a tetracarboxylic acid dianhydride to form an ester or an amide, followed by continuing addition polymerization until the acid number of the whole system has reached 1/2 of the initial value. The aminoalcohols used herein include, for example, monoethanolamine, monoisopropanolamine, diglycolamine and the like. The diols and diamines used herein are the same as above. The degree of polymerization in the ester-forming or amide-forming addition polymerization can be controlled by varying the mole numbers of the diol, diamine or aminoalcohol and the tetracarboxylic acid dianhydride reacted, whereby the content of the structural unit of the general formula (X) in the polymer can be determined. The temperature of the ester-forming or amide-forming addition polymerization is 40° C. to 200° C., preferably 60° C. to 130° C. As a catalyst for the reaction, there can be used bases with pyridine, triethylamine and the like and acids such as sulfonic acid, p-toluenesulfonic acid and the like. The specified hydroxyl compounds can be synthesized by reacting 1 mole of a diepoxy compound having 2 epoxy groups in one molecule with 1 mole or more of at least one compound selected from acrylic or methacrylic compounds having carboxyl groups and acrylic or methacrylic compounds having hydroxyl groups and continuing addition polymerization until the epoxy groups in the reaction system have completely disappeared. The diepoxy compound usable herein include, for example, glycidyl ethers of polyhydric phenols prepared by reacting a polyhydric phenol such as Bisphenol A, halogenated Bisphenol A, hydrogenated Bisphenol A, Bisphenol F, catechol, resorcinol and the like with epichlorohydrin; glycidyl ethers of polyhydric alcohols prepared by reacting epichlorohydrin with a polyhydric alcohol such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol and the like; glycidyl esters of polybasic acids prepared by reacting epichlorohydrin with a polybasic acid such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, adipic acid and the like; epoxy novolac resins prepared by reacting epichlorohydrin with novolac type phenolic resins; glycidylamines prepared by reacting epichlorohydrin with a polyamine such as aniline, 4,4'-diaminodiphenylmethane and the like; alicyclic epoxy compounds such as vinylcyclohexene dioxide, dicyclopentadiene dioxide, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)phthalate and the like; and epoxidized polybutadienes. The above-mentioned addition-polymerization reaction is carried out at a temperature of 20° to 130° C., preferably 40° to 70° C. As the catalyst for the reaction, can be used tertiary amines, imidazoles, metallic salts of organic acids, Lewis acids, amine complexes and the like, among which preferred are triethanolamine, N,N,N',N'-tetramethylethylenediamine, N,N-dimethylpiperazine, N-methylmorpholine and boron trifluoride etherate. These catalysts are used in an amount of 0.01 to 5 parts by weight per 100 parts by weight of the starting materials of the reaction. The specified amine adduct can be obtained by reacting a diepoxy compound with at least equivalent quantity, to the epoxy group of said diepoxy compound, of ammonia or a primary amine either in the absence of catalyst or in the presence of at least one compound selected from water, alcohol, phenol and the like, for example, at a temperature of from room temperature to 150° C. As the diepoxy compounds used herein, the same ones as the above-mentioned ones can be referred to. The primary amine usable herein include, for example, aliphatic amines such as ethylamine, propylamine, butylamine, amylamine and the like; aromatic amines such as aniline, benzylamine and the like; alicyclic amines such as cyclopentylamine, cyclohexylamine and the like; and aminoalcohols such as monoethanolamine, monoisopropanolamine and the like. The catalysts usable in this reaction include water, aliphatic alcohols, phenols, p-toluenesulfonic acid and organic acids such as salicylic acid, formic acid, oxalic acid, acetic acid and the like. The specified sulfonic acid compound can be obtained by reacting one mole of at least one compound selected from diols, diamines and aminoalcohols with less than one mole of at least one selected from dicarboxyl compounds or acid anhydrides thereof having the structural unit of the general formula (VIII) in its molecule and dialkyl esters such as dimethyl esters, diethyl esters and the like thereof to carry out esterification, amide-forming reaction or ester interchange. The degree of polymerization in the addition polymerization by the esterification, amide-forming reaction or ester interchange can be controlled by varying the mole numbers of the starting materials used for reaction, whereby the content of the structural unit of the general formula (VIII) in the specified sulfonic acid compound can be determined. The temperature of the addition polymerization by the esterification, amide-forming reaction or ester interchange is 40° to 220° C., preferably 50° to 180° C. As a catalyst for the esterification or amide-forming reaction, there can be used bases such as pyridine, triethylamine and the like or acids such as sulfonic acid, p-toluenesulfonic acid and the like. Catalysts which can be used for the ester interchange include, in addition to the catalysts usable for the esterification or amide-forming reaction, salts or organic carboxylic acids such as sodium acetate, manganese acetate, zinc acetate, calcium acetate and the like, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and the like, alkali metal alcoholates such as sodium methylate, sodium ethylate and the like, oxides or hydroxides of alkaline earth metals, zinc oxide, organotitanium compounds such as titanium isopropylate and titanium butylate, etc. The diols, diamines, aminoalcohols and the dicarboxyl compounds or acid anhydrides thereof having the structural unit of the general formula (VIII) in its molecule used herein are the same as exemplified above. The specified sulfonic acids can be obtained by subjecting to addition reaction one mole of 2-acrylamido-2,2-dialkylethanesulfonic acid, 2-methacrylamido-2,2-dialkylethanesulfonic acid, 2-acrylamido-2-alkylethanesulfonic acid, 2-methacrylamido-2-alkylethanesulfonic acid, 2-acrylamidoethanesulfonic acid or 2-methacrylamidoethanesulfonic acid (hereinafter referred to as "(Meth)acrylamidoethanesulfonic Acid or the Like") and one mole of dihydroxyalkylamine. The temperature of the addition reaction is 20° to 100° C., preferably 30° to 60° C. The reaction may be carried out by using a catalyst, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and the like, alkali metal salts or alkaline earth metal salts such as potassium carbonate, magnesium sulfate and the like, tertiary amines such as pyridine, α-picoline and the like, metallic sodium, copper acetate, etc. Prior to the reaction, the (meth)acrylamidoethanesulfonic acid may be neutralized in the presence of an alkali such as sodium hydroxide, sodium carbonate and the like. Further, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid can also be used directly in the reaction for producing the polymer as a specified sulfonic acid compound. The alkyl group in the (meth)acrylamidoethanesulfonic acid or the like mean a C 1 to C 8 , preferably C 1 to C 3 , alkyl group such a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and the like, and the alkyl groups in dihydroxyalkylamine include, for example, alkyl groups such as ethyl, isopropyl and the like. A preferred embodiment of the abovementioned Process A will now be described. In the reaction of at least one bifunctional compound selected from diols and diamines with a specified hydroxyl compound and a diisocyanate compound, the specified hydroxyl compound is used in an amount of 0.01 to 5 moles, preferably 0.03 to 3 moles per 1 mole of the bifunctional compound, and the total of the bifunctional compound and the specified hydroxyl compound is 0.1 to 0.9 mole, preferably 0.5 to 0.9 mole per 1 mole of the diisocyanate compound. Usually, a catalyst such as copper naphthenate, cobalt napthenate, zinc naphthenate, n-butyltin laurate, triethylamine and the like is used in an amount of 0.01 to 1 part by weight per 100 parts by weight of the total weight of bifunctional compound, specified hydroxyl compound and diisocyanate compound. The reaction temperature is usually 30° C. to 80° C. In the next step, the polymer formed by the above reaction is reacted with an acrylic or methacrylic compound having a hydroxyl group. In this reaction, said acrylic or methacrylic compound is used in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight per 100 parts by weight of the polymer and the same catalyst as above is used in an amount of 0.01 to 1 part by weight per 100 parts by weight of the polymer. The reaction is carried out at 30° C. to 80° C. Then, the reaction product is further reacted with the specified sulfonic acid compound and, optionally, at least one compound selected from the specified carboxyl compound and the specified amine adduct. The amount of the specified sulfonic acid compound used is 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, per 100 parts by weight of said reaction product, and the amount of the specified carboxyl compound and/or the specified amine adduct is not more 30 parts by weight per 100 parts by weight of said reaction product. The same catalyst as above is used in an amount of 0.01 to 1 part by weight per 100 parts by weight of the polymer, and the reaction temperature is 30° to 80° C. A preferred embodiment of the abovementioned Process B will now be described. In the reaction of at least one bifunctional compound selected from diols and diamines with the specified hydroxyl compound and the diisocyanate compound, the specified hydroxyl compound is used in an amount of 0.01 to 5 moles, preferably 0.03 to 3 moles, per 1 mole of the bifunctional compound. The diisocyanate compound is used in an amount of 0.1 to 0.9 mole, preferably 0.5 to 0.9 mole, per 1 mole of the total amount of the bifunctional compound and the specified hydroxyl compound. In this reaction, the reaction conditions, the catalyst and the like may be the same as in Process A. To 100 parts by weight of the thus obtained polymer, is added 0.1 to 20 parts by weight of a dicarboxyl compound or an acid anhydride thereof having the structural unit of the general formula (VIII) in its molecule, and to the mixture is optionally added not more than 30 parts by weight of a tetracarboxylic acid dianhydride having the structure of R 15 in the general formula (X), and reaction is effected at a temperature of 20° to 180° C., either in the presence of or in the absence of, for example, 0.01 to 10% by weight of a catalyst of a base such as pyridine and triethylamine or an acid such as sulfuric acid and p-toluenesulfonic acid. Subsequently, the polymer obtained by the above reaction is reacted with an acrylic or methacrylic compound having a carboxyl, epoxy or acid halide group. In this reaction, the acrylic or methacrylic compound is used in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of the polymer. A base such as pyridine and triethylamine or an acid such as sulfuric acid and p-toluenesulfonic acid is used as a catalyst in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the polymer, and the reaction is carried out at 20° to 120° C. A preferred embodiment of the abovementioned Process C will now be described. One mole of a diisocyanate compound is mixed with the specified sulfonic acid compound and, optionally, the specified carboxyl compound, and with at least one bifunctional compound selected from diols and diamines and with the specified hydroxyl compound in such amounts that the total amount of the specified sulfonic acid compound, the specified carboxyl compound, the bifunctional compound and the specified hydroxyl compound is 0.1 to 0.95, preferably 0.5 to 0.9 mole, and the resultant mixture is brought into reaction in the presence of a catalyst at 30° to 80° C. The catalysts which can be used herein include copper naphthenate, cobalt naphthenate, zinc naphthenate, n-butyltin laurate, triethylamine and the like. The catalyst is used in an amount of 0.01 to 1 part by weight per 100 parts by weight of the total amount of the diisocyanate compound, the specified sulfonic acid compound and the optionally used specified carboxyl compound, the bifunctional compound and the specified hydroxyl compound. Then, to the polymer thus obtained having isocyanate groups on the ends of its molecule, is added an acrylic or methacrylic compound having hydroxyl groups in such an amount that the hydroxyl groups is in a proportion of 0.1 to 1 mole, preferably 0.2 to 1 mole, per one equivalent of the isocyanate group of the polymer, and the reaction is effected at 30° to 80° C. in the presence of the same catalyst as above. If the reaction product after the reaction contains residual isocyanate groups, the residual isocyanate groups are reacted with the specified amine adduct in the presence of the same catalyst as above at 30° to 80° C., whereby the polymer used in the invention can be obtained. In producing the above-mentioned specified sulfonic acid, specified carboxyl compound or specified hydroxyl compound or in practising the Process A, B or C, a polyol having a functionality of 3 or greater may be used in combination with the diol, a polyamine having a functionality of 3 or greater may be used in combination with the diamine and a polyisocyanate having a functionality of 3 or greater may be used in combination with the diisocyanate compound, in such a way that their combined use causes no gelation of reaction product. Usually, the amount of these polyfunctional compounds usable in combination is 5 to 30 parts by weight per 100 parts by weight of the diol, diamine or diisocyanate. The diols having a functionality of 3 or greater used herein include, for example, addition product of glycerin and propylene oxide, glycerin, 1,2,3-pentanetriol, 1,2,3-butanetriol and the like. The polyamines having a functionality of 3 or greater include, for example, diethylenetriamine, 1,2,3-triaminopropane, polyoxypropyleneamine and the like. The polyisocyanate compounds having a functionality of 3 or greater include, for example, polymethylene-polyphenyl isocyanate, triphenylmethane-4,4',4"-triisocyanate and the like. In producing the specified sulfonic compound, specified carboxyl compound, specified hydroxyl compound or specified amine adduct or in practising the Process A, B or C, a solvent inert to the reaction such as methyl ethyl ketone, cyclohexanone, tetrahydrofuran, toluene, methyl isobutyl ketone, dioxane and the like may be used, if desired. The polymer used in the invention can be produced by any of the above-mentioned processes, and its production process is not limited to those mentioned herein. The proportion of the structural units represented by general formulas (I), (II) and (III) in the polymer used in the invention is preferably 0.2 to 40% by weight, more preferably 0.5 to 30% by weight. If it exceeds 40% by weight, the radiation-cured coating film loses its flexibility and the mechanical properties of the coating are deteriorated. On the other hand, if it is less than 0.2% by weight, the radiation-curing cannot progress sufficiently. In the polymer used in the invention, the proportion of the structural units represented by general formulas (IV), (V), (VI) and (VII) is preferably 60 to 95% by weight, more preferably 75 to 90% by weight. If it is less than 60% by weight, the radiation-cured coating film loses its flexibility and the mechanical properties of the coating film are deteriorated. On the other hand, if it is more than 95% by weight, the radiation-curing cannot progress sufficiently. Among the structural units represented by general formulas (IV), (V), (VI) and (VII), preferred are those represented by the general formulas (V) and (VII). The proportion of the structural units of general formula (VIII) in the polymer of the invention is preferably 0.1 to 20% by weight and particularly 0.3 to 10% by weight. If the proportion of the structural unit of general formula (VIII) is less than 0.1% by weight, the affinity of the coating material for inorganic compounds is insufficient, and particularly the dispersibility of magnetic powder at the time of preparing a magnetic coating material is insufficient. If the proportion of the structural unit of general formula (VIII) is more than 20% by weight, the polymer has too high a polarity. This decreases the solubility of the polymer in general-purpose solvents such as toluene, methyl ethyl ketone and the like, and it simultaneously increases the moisture-absorption of the radiation-cured coating film and thereby deteriorates the strength of the coating. In the polymer used in the invention, the proportion of the structural unit represented by general formula (IX) is preferably 0.5 to 30% by weight, more preferably 1 to 20% by weight. If it is less than 1% by weight, the formation of crosslinkage in the coating film is insufficient after the radiation-curing, which results in a decrease in the strength of the coating film. On the other hand, if it exceeds 30% by weight, the flexibility of radiation-cured coating film is deteriorated. The proportion of the structural units of the general formula (X) or (XI) in the polymer used in the invention, is preferably not more than 30% by weight. By incorporating these structural units, it is possible to control the affinity of the polymer for magnetic powders and the solubility of the polymer in general-purpose solvents in preparing magnetic coating materials, the moisture absorption of a radiation-cured coating and the like. The polymer used in the invention has a molecular weight of 2,000 to 100,000. If it is less than 2,000, the strength of the radiation-cured coating film is low. If it is more than 100,000, the solution viscosity is too high at the time of preparing a coating material, which not only makes the handling troublesome but also makes it necessary to use an increased amount of solvent for the purpose of decreasing the viscosity particularly where the material is used as a magnetic coating material. If desired, the polymer used in the invention may be used in combination with other radiation-curable polymers and/or compounds having radiation-curable unsaturated bond. Said "other radiation-curable polymers" include the following. (1) Polymers having acrylic double bonds on its molecular ends and having a polymer skeleton constituted of polyester, polyurethane, epoxy, polyether, polycarbonate, polyamide, or the like. (2) Polymers represented by the following general formula (a): ##STR23## wherein R 17 is --CH 3 or --C 2 H 5 ; X is ##STR24## (R 18 is H or CH 3 ); Z is ##STR25## (R 19 and R 20 , which may be identical or different, represent C 1 to C 4 alkyl, phenyl or C 1 to C 4 alkoxy, and Y is a group having acrylic or vinyl double bond); t is an integer of 200 to 800; u is an integer of 10 to 200; v is an integer of 0 to 200; w is an integer of 3 to 100; and m is an integer of 0 to 50. (3) Polymers such as polyester, polyether, polyurethane, epoxy, polybutadiene, polyamide, polycarbonate and the like, having two or more acrylic double bonds and at least one hydrophilic group such as --SO 3 M, --OSO 3 M, --COOM, ##STR26## and --OH wherein M is a hydrogen atom, lithium atom, sodium atom or potassium atom; M' is a hydrogen atom, lithium atom, sodium atom, potassium atom or a hydrocarbon group; and R 21 is a hydrocarbon group. (4) Polymers represented by the following general formula (b): ##STR27## wherein R 22 and R 23 represent an aliphatic, alicyclic or aromatic hydrocarbon group or a residue derived therefrom, provided that R 22 optionally has --O-- linkage and R 23 mentioned later, a radiation-curable property to an epoxy polymer phenoxy resin obtained by reacting Bisphenol A or brominated Bisphenol A with epichlorohydrin or methylepichlorohydrin. (9) Polymers prepared by giving a radiation-curable property to a cellulosic polymer such as nitrated cotton, cellulose acetobutyrate, ethylcellulose, butylcellulose, acetylcellulose and the like by the technique mentioned later. (10) Polymer prepared by giving a radiation-curable property to polyfunctional polyethers such as a polyether having one or more hydroxyl groups, and the like, by the technique mentioned later. (11) Polymers prepared by giving a radiation-curable property to polyfunctional polyesters such as polycaprolactone and the like by the technique mentioned later. (12) Polymers prepared by giving a radiation-curable property to a vinyl chloride-vinyl acetate-vinyl alcohol copolymer, a vinyl chloride-vinyl alcohol copolymer, a vinyl chloride-vinyl acetate-maleic acid copolymer, a vinyl chloride-vinyl propionate-vinyl alcohol copolymer or the like by the technique mentioned later. (13) Polymers prepared by giving a radiation-curable property to a polyether-ester polymer, a polyvinyl pyrrolidone polymer, a polyvinyl pyrrolidone-olefin copolymer, a polyamide polymer, a polyimide polymer, a phenolic polymer, a spiroacetal polymer, an acrylic polymer containing at least one member selected from hydroxyl group-containing acrylic and methacrylic esters as its polymer component, or the like by the technique mentioned later. (14) Polymers prepared by giving a radiation-curable property to a butadiene polymer, a styrene-butadiene copolymer, an acrylonitrile-butadiene copolymer or the like having hydroxyl or carboxyl groups on molecular ends by the technique mentioned later. (15) Acrylonitrile-butadiene copolymers, butadiene polymers, styrene-butadiene copolymers, isoprene polymers, acryl rubbers, chlorinated rubbers, and epoxy-modified rubbers. (16) Conjugated diene polymers such as polybutadiene, polyisoprene and the like. (17) Polymers prepared by adding α,β-ethylenically unsaturated monocarboxylic acid to epoxidized diene polymers. (18) Polymers prepared by adding α,β-ethylenically unsaturated monocarboxylic acid to epoxy group of the polymers or copolymers of glycidyl acrylate or glycidyl methacrylate. Next, specific examples of the above-mentioned technique for giving a radiation-curable property will be described. (I) One mole of the above-mentioned thermoplastic polymer having hydroxyl groups in its molecule or a prepolymer thereof is reacted with one mole or more of the isocyanate group of a polyisocyanate compound and then with one mole or more of a monomer having a functional group reactive with the isocyanate group and a radiation-curable unsaturated double bond. The monomers having a functional group reactive with the isocyanate group and a radiation-curable unsaturated double bond include ester monomers having hydroxyl group such as 2-hydroxyethyl esters, 2-hydroxypropyl esters, 2-hydroxyoctyl esters and the like of acrylic acid and methacrylic acid; monomers having an active hydrogen atom reactive with the isocyanate group and having an acrylic double bond, such as acrylamide, methacrylamide, N-methylolacrylamide and the like; and monomers having an active hydrogen atom reactive with isocyanate group and having a radiation-curable unsaturated double bond, such as allyl alcohol, polyhydric alcohol esters of maleic acid, mono- or di-glycerides of long chain fatty acids having an unsaturated double bond, and the like. (II) One mole of the above-mentioned thermoplastic polymer having hydroxyl groups in its molecule or a prepolymer thereof is reacted with one mole or more of an acid or an acid chloride having a radiation-curable unsaturated double bond to introduce the double bond via ester linkage. Examples of said acid halide having radiation-curable unsaturated double bond include acrylic acid, methacrylic acid, methacrylic acid chloride, acrylic acid chloride, acrylic acid bromide, methacrylic acid bromide, and the like. (III) One mole of the above-mentioned thermoplastic polymer having carboxyl group in its molecule or a prepolymer thereof is reacted with one mole or more of a monomer having a functional group reactive with the carboxyl group and a radiation-curable unsaturated double bond. Examples of said monomer having a functional group reactive with the carboxyl group and a radiation-curable unsaturated double bond include glycidyl acrylate, glycidyl methacrylate and the like. The above-mentioned "other radiation-curable polymers" may be used in combination of two or more members. Usually, they are used in an amount of 400 parts by weight or less per 100 parts by weight of the polymer constituting the characteristic feature of the invention. Examples of said compound having a radiation-curable double bond include acrylic acid and acrylic esters such as acrylic acid, ethyl acrylate, propyl acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, hydroxyethyl acrylate, phenoxyethyl acrylate, 2-ethylhexyl acrylate, dibromopropyl acrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, adduct of isophorone-diisocyanate and hydroxyethyl acrylate, trishydroxyethyl isocyanurate triacrylate and the like; acrylamides such as acrylamide, N-methylacrylamide and the like; methacrylic acid; methacrylic esters such as ethyl methacrylate, propyl methacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, hydroxyethyl methacrylate, phenoxyethyl methacrylate, 2-ethylhexyl methacrylate, dibromopropyl methacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, trishydroxyethyl isocyanurate trimethacrylate and the like; methacrylamides such as methacrylamide, N-methylmethacrylamide and the like; vinylpyrrolidone; and phosphoric esters having a radiation-curable unsaturated bond. The compounds having a radiation-curable unsaturated bond can be used in combination of two or more members, and they are used preferably in an amount of 5 to 90 parts by weight, more preferably in an amount of 10 to 80 parts by weight per 100 parts by weight of the polymer constituting the characteristic feature of the invention. The magnetic powders to be mixed into the radiation-curable coating material of the invention when the latter is used as a magnetic coating material, include γ-Fe 2 O 3 , Fe 3 O 4 , iron oxide having an intermediate oxidation state between γ-Fe 2 O 3 and Fe 3 O 4 , Co-containing γ-Fe 2 O 3 , Co-containing Fe 3 O 4 , Co-containing iron oxide having an intermediate oxidation state between Co-containing γ-Fe 2 O 3 and Co-containing Fe 3 O 4 , the latter iron oxide additionally containing a metallic element such as transition metal element and the like, the latter iron oxide having on its surface a coating layer composed mainly of Co oxide or Co hydroxide, CrO 2 , CrO 2 of which surface has been reduced to form a Cr 2 O 3 layer, elementary metals such as Fe, Co, Ni and the like, alloys of these metals, alloys of these metals additionally containing other metallic element, transition metal element and the like, and so on. These magnetic powders are used usually in an amount of 200 to 700 parts by weight per 100 parts by weight of the polymer constituting the characteristic feature of the invention. The solvents which can be used in preparing the radiation-curable coating material of the invention include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like; esters such as ethyl formate, ethyl acetate, butyl acetate and the like; alcohols such as methanol, ethanol, isopropanol, butanol and the like; aromatic hydrocarbons such as toluene, xylene, ethylbenzene and the like; aliphatic hydrocarbons such as hexane, heptane and the like; and glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, dioxane and the like. These solvents are used singly or in combination, usually in an amount of 200 to 2,500 parts by weight per 100 parts by weight of the polymer constituting the characteristic feature of the invention. In preparing the radiation-curable coating material of the invention, a dispersant such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, stearolic acid, lecithin, organotitanium compound, organosilane compound and the like; a lubricant such as molybdenum disulfide, graphite, silicone oil and the like; an abrasive such as aluminum oxide, chromium oxide, silicon oxide and the like; an electrically conductive fine powder such as carbon black-graft polymer and the like; a natural surfactant such as saponin and the like; a nonionic surfactant of alkylene oxide type, glycerin type, glycidol type or the like; a cationic surfactant such as higher alkylamines, quaternary ammonium salts, pyridine, phosphoniums, sulfoniums and the like; anionic surfactants having acidic group such as carboxyl group, sulfonic acid group, phosphoric acid group, sulfuric ester group, phosphoric ester group and the like; amphoteric surfactants such as amino acids, aminosulfonic acids, aminoalcohol sulfates or phosphates, and the like; antistatic agent such as carbon black and the like; and rustproofing agent such as phosphoric acid, sulfamide, pyridine, dicyclohexylamine nitrite, cyclohexylammonium carbonate and the like may be compounded into the coating material. Further, if desired, polyvinyl butyral, polyvinyl acetal, polyurethane, polyester, polyester having sulfonic acid group and/or metallic base in its molecule, epoxy resin, epoxy-urethane resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, hydroxyl group-containing vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer, hydroxyl group-containing vinyl chloride-vinyl propionate copolymer, vinyl chloride-vinyl acetate-acrylic ester copolymer, hydroxyl group-containing vinyl chloride-vinyl acetate-acrylic ester copolymer, polyvinylidene chloride, maleic acid-containing vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinylidene chloride copolymer, vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-methacrylic ester copolymer, phenoxy resin, nitrocellulose, nitrated cotton, ketone resin, polymers and copolymers of acrylic acid and methacrylic acid, polymers and copolymers of acrylic ester and methacrylic ester, polyimide resin, 1,3-pentadiene resin, epoxidized 1,3-pentadiene resin, hydroxylated 1,3-pentadiene resin, polymers and copolymers of acrylonitrile, acrylic ester-acrylonitrile copolymer, methacrylic ester-acrylonitrile copolymer, phenolformaldehyde resin, phenol-furfural resin, xyleneformaldehyde resin, urea resin, melamine resin, alkyd resin, acrylonitrile-butadiene-styrene copolymer and the like may be compounded into the radiation-curable coating material of the invention. The substrates (base film) which can be used for the production of magnetic recording media using the radiation-curable coating material of the invention as a magnetic coating material include, for example, polyesters such as polyethylene terephthalate and the like; polyolefins such as polypropylene and the like; cellulose derivatives such as cellulose triacetate, cellulose diacetate and the like; polycarbonate, polyvinyl chloride; chloride; polyimide; nonmagnetic metals such as aluminum copper and the like; and paper. The radiations which can be used for crosslinking and curing the radiation-curable coating material of the invention include electron beam, γ-ray, neutron beam, β-ray, X-ray and the like, among which electron beam is particularly preferable from the viewpoint of the easiness to control radiation dose and the easiness to introduce the apparatus for projecting the radiation into the production process. The electron beams used for crosslinking and curing the coating film are preferably projected so that the dose of electron beam absorbed into the coating comes to 0.5 to 20 Megarad, by using an electron beam accelerator having an acceleration voltage of 100 to 750 KV, preferably 150 to 300 KV, from the viewpoint of transmitting power. WORKING EXAMPLES The present invention will be described more in detail below by way of working examples, but the invention is not limited to these working examples. In the working examples below the molecular weights are those measured by the osmotic pressure method and the structures of compounds are those revealed by infrared spectrometric and NMR spectrometric analyses. Example 1 (1) In a 1 liter flask equipped with a thermometer, a stirrer and a reflux condenser, there were placed 144 g of acrylic acid and 336 g of bisphenol A diglycidyl ether (Epikote 828, manufactured by Yuka Shell Epoxy K.K.), and the reactants were reacted at 60° C. for 6 hours. The absence of epoxy ring from the reaction product was confirmed by means of an infrared absorption spectrum. This reaction product is referred to as "Specified Hydroxyl Compound (I)". The major structure of Specific Hydroxyl Compound (I): ##STR28## (2) In a 1 liter flask equipped with a thermometer, a stirrer and a reflux condenser, there were placed 118.4 g of dimethyl 5-sodium-sulfoisophthalate, 198.4 g of ethylene glycol and 1.64 g of sodium acetate, and the reactants were reacted at 100° C. for 4 hours. The ratio of ester interchange was 96% according to the amount of methanol which is a by-product of the reaction. (The ratio of ester interchange herein means the amount of methanol formed divided by the theoretical value). According to NMR spectroscopic analyses of the reaction product, the absence of the peak corresponding to the proton of the methyl group of dimethyl 5-sodium-sulfoisophthalate and the presence of unreacted ethylene glycol were confirmed. Further, the integral ratios of proton peaks showed that the reaction product was a mixture of the compounds of the following structural formula. The amount of the unreacted ethylene glycol was determined by liquid chromatography to be 53.5% by weight. The mixture thus obtained is referred to as "Specified Sulfonic Acid Compound (D-1)". The major structure of Specified Sulfonic Acid Compound (D-1) ##STR29## Further, gel permeation chromatography showed that the molecular weight of the reaction product was not greater than 1000 and n in the above structural formula was an integer of from 0 to 3. The hydroxyl equivalent of the Specified Sulfonic Acid Compound was 1.92×10 -2 mol/g, the number-average molecular weight was 104, and the content of sulfonic acid groups was found by elemental analysis to be 1.4×10 -3 mol/g. (3) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 47.7 g of toluene diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of ethyl methyl ketone. While the mixture was maintained at 60° C., a mixture of 133.9 g of polyether diol (Teracol 650, manufactured by Du Pont) and 16.5 g of Specified Hydroxyl Compound (I) was dropped in with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 4 hours, and then 6.4 g of pentaerythritol triacrylate was added to the mixture and reaction was carried out at 60° C. for another 2 hours under stirring. Then, 2.37 g of Specified Sulfonic Acid Compound (D-1) was added to the mixture and reaction was carried out at 60° C. for 2 hours. The absence of isocyanate group from the system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (F)". The major structural formula and the molecular weight of Polymer (F) are shown in Table 1. Example 2 (1) In a 1 liter flask equipped wwith a thermometer, a stirrer and a reflux condenser, there were placed 344 g of methacrylic acid, 348 g of ethylene glycol diglycidyl ether and 10 g of N-methylmorpholine, and the reactants were reacted at 60° C. for 4 hours. The absence of epoxy ring from the reaction product was confirmed by an infrared absorption spectrum. This reaction product is referred to as "Specified Hydroxyl Compound (II)". The major structure of Specified Hydroxyl Compound (II): ##STR30## (2) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 47.2 g of 4-sodium-sulfophthalic acid and 250 g of tetrahydrofuran, and the mixture was heated to 50° C. Then, 160 g of polyoxypropylene diamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Co.) was dropped in under stirring using the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred for 2 hours before distilling off tetrahydrofuran under reduced pressure to obtain Specified Sulfonic Acid Compound (D-II) as a viscous liquid. The amount of primary amine in Specified Sulfonic Acid Compound was measured to be 1.93×10 -3 equivalent/g. The major structure of Specified Sulfonic Acid Compound (D-II): ##STR31## wherein R 25 represents a polyoxypropylene chain which is a residual group corresponding to polyoxypropylene diamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Company) without both terminal amino groups. (3) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 43.6 g of pyromellitic dianhydride and 500 g of methyl ethyl ketone, and the mixture was heated to 60° C. to dissolve pyromellitic dianhydride. Thereafter, the mixture was heated to 70° C., and 195 g of polyether-diol (Tetracol 650, manufactured by Du Pont) was then slowly dropped in. After dropping, the resultant mixture was reacted at 70° C. for 6 hours and then cooled to room temperature. The acid equivalent of the reaction product was measured to be 5.4×10 -4 equivalent/g. The reaction product thus obtained (solid content: 32.3% by weight) is referred to as "Specified Carboxyl Compound (I)". The major structure of Specified Carboxyl Compound (I): ##STR32## ps wherein R 26 represents a polyoxypropylene tetramethylene chain which is a residual group corresponding to polytetramethylene glycol (Teracol 650) without both terminal hydroxyl groups. (4) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, 200 g of monoethanolamine was placed and heated to 40° C. Then, a solution of 200 g of bisphenol A diglycidyl ether (Epikote 828, manufactured by Yuka Shell Epoxy K.K.) in 100 g of toluene was dropped in while maintaining the system at 40° C. After dropping, the resultant mixture was stirred for 3 hours. After distilling off toluene from the reaction system, the residue was heated at 100° C. under a reduced pressure of 1 to 3 mmHg to distill off the unreacted monoethanolamine to obtain a reaction product as white solid. The reaction product thus obtained is referred to as "Specified Amine Adduct (I)". The major structure of Specified Amine Adduct (I): ##STR33## (5) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 57.6 g of methylene bis(4-cyclohexylisocyanate), 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone, and the mixture was heated to 60° C. Then, from the dropping funnel, a mixture of 17.6 g of polyoxypropylenediamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Company), 110 g of polyester diol (NIPPORAN 141, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 17.6 g of Specified Hydroxy Compound (II) was dropped in so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 4 hours, and 2.6 g of hydroxyethyl acrylate was added in the mixture and reaction was carried out at 60° C. for another 2 hours under stirring. Then, 11.4 g of Specified Sulfonic Acid Compound (D-II) was added to the mixture, followed by reaction at 60° C. for 2 hours. Thereafter, 26.2 g of Specified Carboxyl Compound (I) solution in methyl ethyl ketone was added and reacted at 60° C. for 7 hours. Further, 5.1 g of Specified Amine Adduct (I) was added and reacted at 60° C. for 2 hours. Upon completion of the reaction, the absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (G)". The major structure and the molecular weight of Polymer (G) are shown in Table 1. Example 3 (1) In a 1 liter flask equipped with a thermometer, a stirrer, and a reflux condenser, there were placed 144 g of acrylic acid, 526 g of polyethylene glycol diglycidyl ether (Epolite 400E, manufactured by Kyoeisha Chemical Co., Ltd.) and 2 g of boron trifluoride etherate, and the reactants were reacted at 60° C. for 4 hours. The absence of the absorption by epoxy rings from the reaction product was confirmed by an infrared absorption spectrum. The reaction product is referred to as "Specified Hydroxyl Compound (III)". The major structure of Specified Hydroxyl Compound (III): ##STR34## (2) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 115.5 g of 2-acrylamide-2-methylpropanesulfonic acid, 20 g of sodium hydroxide and 300 g of methanol, and then 52.5 g of diethanolamine was dropped in from the dropping funnel while preventing the system temperature from exceeding 40° C. After dropping, the resultant mixture was reacted at 40° C. for 2 hours under stirring. The solvent was then distilled off under reduced pressure to obtain a reaction product as a white solid. The reaction product thus obtained is referred to as "Specified Sulfonic Acid Compounds (E-I)". The major structure of Specified Sulfonic Acid Compound (E-I): ##STR35## (3) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, 365 g of n-butylamine was placed and heated to 40° C. Then, 268 g of polypropylene glycol diglycidyl ether (Epolite 400P, manufactured by Kyoeisha Chemical Co., Ltd.) dissolved in 100 g of tetrahydrofuran was dropped in so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 40° C. for 3 hours. The reaction system was then heated to 100° C. to distill off the unreacted n-butylamine to obtain a reaction product as a white solid. The reaction product thus obtained is referred to as "Specified Amine Adduct (II)". The major structure of Specified Amine Adduct (II): ##STR36## (4) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 60.0 g of 4,4'-diphenylmethane diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. While the mixture was maintained at 60° C., a mixture of 120 g of polyester-diol (NIPPORAN 141, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 40.2 g of Specified Hydroxy Compound (III) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 4 hours, and then 21.0 g of dipentaerythritol triacrylate was added to the mixture, followed by reaction at 60° C. for 2 hours under stirring. Then, 6.7 g of Specified Sulfonic Acid Compound (E-I) was added and reacted at 60° C. for 2 hours. To the reaction system, 13.6 g of Specified Amine Adduct (II) was further added and reacted at 60° C. for another 2 hours. After the reaction, the absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer H". The structural formula and the molecular weight of polymer H are shown in Table 1. Example 4 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 57.4 g of methylenebis(4-cyclohexylisocyanate), 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone, and the mixture was maintained at 60° C. From the dropping funnel, 17.6 g of polyether-diamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Company) was dropped in with care so as to prevent the system temperature from rising. The resultant mixture was reacted at 60° C. for 1 hour. Then, a mixture of 10.6 g of Specified Hydroxyl Compound (I) and 110 g of polyester-diol (NIPPORAN 141, manufactured by Nippon Polyurethane Industry Co., Ltd.) was dropped in. After dropping, the resultant mixture was stirred at 60° C. for 2 hours, and then 6.2 g of pentaerythritol triacrylate was added thereto and the mixture was reacted at 60° C. for 2 hours. Then, 4.7 g of N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid was added and reacted at 60° C. for 7 hours. To the reaction system, 5.1 g of Specified Amine Adduct (I) was further added and reacted at 60° C. for 2 hours. The absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer J". The major structural formula and the molecular weight of Polymer J are shown in Table 1. Example 5 (1) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 105 g of 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride and 200 g of tetrahydrofuran, and the mixture was heated to 40° C. Then, 105 g (1 mol) of diglycylamine was dropped in from the dropping funnel under stirring so as to prevent the system temperature from rising. After dropping, tetrahydrofuran was immediately distilled off under reduced pressure to obtain a viscous liquid, "Specified Carboxyl Compound (II)". The acid equivalent of Specified Carboxyl Compound was measured to be 4.76×10 -3 equivalent/g. The major structure of Specified Carboxyl Compound (II): ##STR37## (2) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 39.2 g of toluene diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. While the mixture was maintained at 60° C., a mixture of 2.7 g of ethylenediamine, 210 g of polycaprolacetonepolyol (Placcel 220N-1, manufactured by Daicel Chemical Industries, Ltd.) and 14.5 g of Specified Hydroxyl Compound (I) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 2 hours, and then 3.5 g of 2-hydroxyethyl acrylate was added thereto and reacted at 60° C. for 1 hour. Then, 2.6 g of Specified Sulfonic Acid Compound (D-I) was added to the mixture, followed by reaction at 60° C. for 2 hours. To the reaction system, 2.1 g of Specified Carboxyl Compound (II) was further added and reacted at 60° C. for 7 hours. The absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (K)". The major structural formula and the molecular weight of Polymer (K) are shown in Table 1. Example 6 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 90 g of 4,4'-diphenylmethane diisocyanate, 0.2 g of dibutyltin dilaurate and 350 g of methyl ethyl ketone. While the mixture was maintained at 60° C., a mixture of 32 g of polyoxypropylene diamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Co., Ltd.), 128 g of polycarbonate diol (PC-DIOL 120-800, manufactured by PPG Co., Ltd.) and 29 g of Specified Hydroxyl Compound (I) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 2 hours, and then 2.3 g of 2-hydroxyethyl acrylate was added thereto, followed by reaction at 60° C. for 1 hour. Then, 31 g of Specified Sulfonic Acid Compound (D-II) was added and reacted at 60° C. for 2 hours. To the reaction system, 13.6 g of Specified Amine Adduct (II) was further added and reacted at 60° C. for another 2 hours. The absence of isocyanate group in the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (L)". The major structural formula and the molecular weight of Polymer (L) are shown in Table 1. Example 7 (1) In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 43.6 g of pyromellitic dianhydride and 500 g of methyl ethyl ketone, and the mixture was heated to 60° C. to dissolve pyromellitic dianhydride. After raising the temperature of the mixture to 70° C., 100 g of polyether diamine (Jeffamine D400, manufactured by Mitsui Texaco Chemical Co., Ltd.) was added thereto so as to prevent the inner temperature for exceeding 65° C. After dropping, the resultant mixture was stirred at 60° C. for 2 hours and cooled to room temperature. The acid equivalent of the system was measured to be 6.2×10 -4 equivalent/g. The reaction product thus obtained (solid content: 22.3 wt.%) was referred to as "Specified Carboxyl Compound (III)". The major structure of Specified Carboxyl Compound (III): ##STR38## wherein R 27 is poly(oxypropylene) chain which is the residual group corresponding to polyoxypropylene diamine (Jeffamine D400) without the terminal amino groups. (2) In a 1 liter flask equipped with a thermometer, a stirrer, reflux condenser and a dropping funnel, there were placed 62.6 of toluene diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. While the mixture was maintained at 60° C., a mixture of 130 g of polyether-diol (Teracol 650, manufactured by Du Pont Co.) and 48.4 g of Specified Hydroxyl Company (I) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was reacted at 60° C. for 4 hours. Then, 11.2 g of pentaerythritol triacrylate was added and the resultant mixture was stirred at 60° C. for 2 hours. Thereafter 6.7 g of Specified Sulfonic Acid Compound (E-I) was added thereto, followed by reaction at 60° C. for 2 hours. To the reaction system, 57.4 g of Specified Carboxyl Compound (III) was further added and reacted at 60° C. for 4 hours under stirring. The absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (M)". The major structural formula and the molecular weight of Polymer (M) are shown in Table 1. Example 8 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 120 g of polypropylene glycol (Uniol D400, manufactured by Nippon Oils & Fats Co., Ltd.), 29.0 g of Specified Hydroxyl Compound (I), 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. While the mixture was maintained at 60° C., 78.3 g of methylenebis(4-cyclohexylisocyanate) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was stirred at 60° C. for 4 hours, and then 8.0 g of 2-sodiumsulfoterephthalic acid was added, followed by reaction at 70° C. for 6 hours. To the reaction system, 5.4 g of acrylic chloride was added and reacted at 70° C. for another 2 hours. The polymer thus obtained is referred to as "Polymer (N)". The major structural formula and the molecular weight of Polymer (N) are shown in Table 1. Example 9 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 3.0 g of ethylenediamine, 150 g of polyesterdiol (NIPPORAN 141, manufactured by Nippon Polyurethane Industry Co., Ltd.), 34.6 g of Specified Hydroxyl Compound (II), 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. While the mixture was maintained at 60° C., 62.5 g of 4,4'-diphenylmethane diisocyanate was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was reacted at 60° C. for 4 hours, and then 5-sodium-sulfopropoxyisophthalic acid was added thereto, followed by reaction at 70° C. for 6 hours. To the reaction system, 7.1 g of methacrylic acid glycidyl ether was further added and reacted at 60° C. for 2 hours. The polymer thus obtained is referred to as "Polymer (P)". The major structural formula and the molecular weight of Polymer (P) are shown in Table 1. Example 10 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 52.2 g of toluene diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. After the mixture was heated to 60° C., a mixture of 168 g of polycarbonate diol (PC-DIOL 120-800, manufactured by PPG Co., Ltd.), 20.1 g of Specified Hydroxyl Compound (III) and 4.16 g of Specified Sulfonic Acid Compound (D-I) was dropped in from the dropping funnel so as to prevent the system temperature from rising. After dropping, the resultant mixture was reacted at 60° C. for 4 hours, and 2.3 g of 2-hydroxyethyl acrylate was then added thereto, followed by reaction at 60° C. for 2 hours. To the reaction system, 4.62 of Specified Amine Adduct (II) was further added and reacted at 60° C. for another 2 hours. The absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as "Polymer (Q)". The major structural formula and the molecular weight of Polymer Q are shown in Table 1. Example 11 In a 1 liter flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, there were placed 80 g of 4,4'-diphenylmethane diisocyanate, 0.2 g of dibutyltin dilaurate and 300 g of methyl ethyl ketone. After the mixture was heated to 60° C., a mixture of 156 g of polyether diol (Teracol 650, maufactured by Du Pont), 19.4 g of Specified Hydroxyl Compound (I) and 0.6 g of Specified Sulfonic acid (D-II) was dropped in from the dropping funnel with care so as to prevent the system temperature from rising. After dropping, the resultant mixture was reacted at 60° C. for 4 hours, and then 5.6 g of pentaerythritol triacrylate was added and reacted for 2 hours at 60° C. To the reaction system, 6.8 g of Specified Amine Adduct (II) was further added and reacted at 60° C. for another 2 hours. The absence of isocyanate group from the reaction system was confirmed by an infrared absorption spectrum. The polymer thus obtained is referred to as Polymer "S". The major structural formula and the molecular weight of Polymer "S" are shown in Table 1. TABLE 1 Molec- Exam- ular ple Structural formula weight 1(Poly-mer F) ##STR39## 1.9 ×10.sup.4 ##STR40## 2(Poly-mer G) ##STR41## 2.2 ×10.sup.4 ##STR42## ##STR43## 3(Poly-mer H) ##STR44## 1.3 ×10.sup.4 ##STR45## ##STR46## 4(Poly-mer J) ##STR47## 1.9 ×10.sup.4 ##STR48## 5(Poly-mer K) ##STR49## 1.9 ×10.sup.4 ##STR50## 6 (Poly-mer L) ##STR51## 3.3 ×10.sup.4 ##STR52## 7(Poly-merM) ##STR53## 1.6 ×10.sup.4 ##STR54## 8(Poly-mer N) ##STR55## 8 ×10.sup.3 9(Poly-mer P) ##STR56## 1.1 ×10.sup.4 ##STR57## 10(Poly-mer Q) ##STR58## 2.7 ×10.sup.4 ##STR59## 11(Poly-mer S) ##STR60## 1.6 ×10.sup.4 ##STR61## Note for Table 1 R.sub.28 : a residual group corresponding to toluene diisocyanate without both terminal isocyanate groups R.sub.29 : a residual group corresponding to polyether diol (Teracol 650, manufactured by Du Pont) without both terminal hydroxyl groups R.sub.30 : a residual group corresponding to Specified Hydroxyl Compound (I) without the terminal hydroxyl groups R.sub.30 : a residual group corresponding to Specified Sulfonic Acid Compound (D-I) without both terminal hydroxyl groups R.sub.32 : a residual group corresponding to methylenebis-(cyclohexyl isocyanate) without both terminal isocyanate groups R.sub.33 : a residual group corresponding to polyester diol (NIPPORAN 141, manufactured by Nippon Polyurethane Industry Co., Ltd.) without both terminal hydroxyl groups R.sub.34 : a residual group corresponding to polyoxypropylene diamine (Jeffamine D400, Mitsui Texaco Chemical Co., Ltd.) without both terminal amino groups R.sub.35 : a residual group corresponding to Specified Hydroxyl Compound (II) without both terminal hydroxyl groups R.sub.36 : a residual group corresponding to Specified Sulfonic Acid Compound (D-II) without both terminal amino groups R.sub.37 : A residual group corresponding to Specified Carboxyl Compound (I) without both terminal hydroxyl groups R.sub.38 : a residual group corresponding to Specified Amine Adduct (I) without both terminal amino groups R.sub.39 : a residual group corresponding to 4,4'-diphenylmethane diisocyanate without both terminal isocyanate groups R.sub.40 : a residual group corresponding to Specified Hydroxyl Compound (III) without both terminal hydroxyl groups R.sub.41 : a residual group corresponding to Specified Sulfonic Acid Compound (E-I) without both terminal hydroxyl groups R.sub.42 : a residual group corresponding to Specified Amine Adduct (II) without both terminal amino groups R.sub.43 : a residual group corresponding to polycaprolactone diol (Placcel 220N-1, manufactured by Daicel Chemical Industries, Ltd.) without both terminal hydroxyl groups R.sub.44 : a residual group corresponding to Specified Carboxyl Compound (II) without both terminal hydroxyl groups R.sub.45 : a residual group corresponding to polycarbonate diol (PC-DIOL 120-800, manufactured by PPG Co., Ltd.) without both terminal hydroxyl groups R.sub.46 : a residual group corresponding to Specified Carboxyl Compound (III) without both terminal amino groups R.sub.47 : a residual group corresponding to polyproplyene glycol (UNIOL D400, manufactured by Nippon Oils & Fats Co., Ltd.) without both terminal hydroxyl groups Referential Example 1 A magnetic coating material having the following composition was prepared in the manner mentioned below using a solution of Polymer F obtained in Example 1 in methyl ethyl ketone. The coating material was applied to a substrate and cured by irradiation with electron beams. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 parts by weightPolymer F 17 parts by weight (on a solids basis)Trimethylolpropane triacrylate 3 parts by weightMethyl ethyl ketone 200 parts by weight______________________________________ Among the above-mentioned components, the magnetic powder, trimethylolpropane triacrylate and methyl ethyl ketone were placed in a 500 ml aluminium can together with stainless steel balls having a diameter of 3 mm (about 20 ml), and the can was shaken for 2 hours by a paint conditioner manufactured by Red Devil Co. (USA). A solution of Polymer A in 2-butanone was then added to the mixture, and the resultant mixture was shaken for an additional 4 hours. Thereafter the steel balls were removed to obtain a magnetic coating material. The magnetic coating material was immediately applied to a polyester film (15μ in thickness) in a dried coating thickness of 6μ. The coating was immediately subjected to a magnetic field orientation treatment. After drying the coating film overnight at room temperature, it was cured by means of an electrocurtain type electron beam accelerator at an acceleration voltage of 160 KV and an absorbed dose of 7 Megarad. For comparison, the same magnetic composition as above except that it contained no magnetic powder was prepared from Polymer F, trimethylolpropane triacrylate and methyl ethyl ketone. The coating material was applied to a glass plate in a dried coating thickness of 40 to 60μ. After drying the coating film overnight at room temperature, it was cured at an acceleration voltage of 160 KV and an absorbed dose of 5 Megarad. The magnetic coating material was subjected to the following test (1), and the cured magnetic coating film was subjected to the following tests (2) to (6). The cured coating film containing no magnetic powder was subjected to the following tests (7) to (8). Apart from the above, still another cured coating film was prepared and subjected to the following test (9). The results are shown in Table 2. (1) Filtration Test: The magnetic coating material was filtered with a filter having a mean pore size of 2μ to examine its 100% filtrability within one minute. (2) Gloss: Gloss of the cured magnetic coating film was measured at a reflexion angle of 45° using a digital gloss-meter (manufactured by Murakami Shikisai Gijutsu Kenkyujo). Symbols ⊚ , ○ , Δand x signify that the gloss is 70-90, 50-70, 30-50 and 30 or less, respectively. (3) Surface: The surface of the cured magnetic coating film was examined using a scanning electron microscope. The symbol ⊚ means that no aggregation of magnetic powder was observed. Surface states of inferior appearance were expressed by symbols ○ , Δand x, in the order of increasing inferiority. (4) Adhesion Test: A pressure-sensitive adhesive tape was stuck on the surface of the cured magnetic coating film so that the tape uniformly adhered to the whole area of the coating film, and then the tape was instantaneously peeled off and the state of the coating film after peeling was visually examined. A complete peeling of the cured magnetic coating film from the substrate was expressed by symbol x; a partial peeling of the coating film from the substrate was expressed by symbol Δ; little peeling was expressed by symbol ○ ; and no peeling was expressed by symbol ⊚ . (5) Abrasion Test: The cured magnetic coating film was 20 times shaved on a #1000 Emery paper, and the amount of abraded powder was measured. (6) Ratio of rectangular hysteresis (Br/Bm): The magnetic properties were measured in an external magnetic field of 5,000 ce using VSM-3 manufactured by Touei Kogyo K.K. "Br" denotes the residual magnetic flux density, and "Bm" denotes the maximum residual magnetic flux density. (7) Breaking strength, Elongation and Initial Modulus: A rectangular test specimen measuring 0.5 cm×10 cm×40-60μ was cut out from the cured coating film. Its breaking strength, elongation and initial modulus were measured at a tensile speed of 50 mm/min at room temperature. (8) Tetrahydrofuran (THF) Unextractable Residue: Using a Soxhlet extractor, the cured coating film was extracted with tetrahydrofuran for 24 hours to determine the ratio of unextractable residue. (9) Bending Test: Polymer A obtained in Example 1 was applied to a polyester film (100 μm in thickness) to form a coating film with a thickness of 40 to 50μ in dry state. After drying the coating film overnight at room temperature, the resulting transparent film was cured by irradiation with electron beams at an acceleration voltage of 160 KV and a dose of 5 Megarad. The cured transparent film was cut into rectangular strips having a width of 1 cm together with the substrate polyester film. The test strips were subjected to a bending test comprising the steps of bending a strip at the middle portion while fixing its two ends and then immediately restoring to the original position. The steps were repeated 20 times in one second to examine if the transparent film showed any peeling or breakage at the bent portion. Test strips which withstood bending for 500 hours were evaluated as "excellent". Referential Example 2 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer G 17 parts (on a solids basis)Trimethylolpropane triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 3 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer H 17 parts (on a solid basis)Trimethylolpropane triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 4 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer H 20 parts (on a solids basis)Methyl ethyl ketone 200 parts______________________________________ Referential Example 5 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer J 17 parts (on a solid basis)Pentaerythritol triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 6 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer K 17 parts (on a solids basis)Pentaerythritol triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 7 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer L 17 parts (on a solids basis)Diethylene glycol diacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 8 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer M 17 parts (on a solids basis)Trimethylolpropane triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 9 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer N 17 parts (on a solids basis)Trimethylolpropane triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 10 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer N 20 parts (on a solids basis)Methyl ethyl ketone 200 parts______________________________________ Referential Example 11 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2 ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer P 17 parts (on a solids basis)Pentaerythritol triacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 12 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer Q 17 parts (on a solids basis)Diethylene glycol diacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ Referential Example 13 A coating material having the composition given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer Q 20 parts (on a solids basis)Methyl ethyl ketone 200 parts______________________________________ Referential Example 14 A coating material having the composition as given below was subjected to the same tests as in Referential Example 1. The results are shown in Table 2. ______________________________________Co--containing γ-Fe.sub.2 O.sub.3 80 partsPolymer S 17 parts (on a solids basis)Diethylene glycol diacrylate 3 partsMethyl ethyl ketone 200 parts______________________________________ EFFECT OF THE INVENTION The present invention has the following effects: (1) The cured coating film of the coating material for use in radiation curing of the invention has not only good mechanical properties but also good adhesion to substrates such as magnetic recording media, etc. (2) The coating material for use in radiation curing of the invention, because of its good radiation crosslinkability, can be sufficiently cured by a low exposed dose of radiation to provide a highly solvent-resistant coating film; namely, the coating can be cured by a reduced amount of energy. (3) The coating material for use in radiation curing of the invention, particularly the magnetic coating material, can be handled easily because of its low viscosity as compared with conventional coating materials, and has good leveling properties, so that a coating film having a markedly high surface smoothness can be obtained. (4) In the case of the magnetic coating material prepared by blending the coating material for use in radiation curing of the invention with a magnetic powder, the coating material has good affinity for the magnetic powder, thereby permitting easy dispersion of the magnetic powder in the coating material and ensuring a great increase in the loadings of the magnetic powder into the coating material. Accordingly, the coating material for use in radiation curing of the invention enables preparation of a magnetic coating material capable of producing magnetic recording media having good magnetic conversion characteristics. (5) The coating film of the coating material for use in radiation curing of the invention can be cured to have appropriate flexibility and surface hardness even where crosslink density is raised by increasing the irradiation dose of radiation. Therefore, where the coating material of the invention is used as a magnetic coating material in producing a magnetic tape, one of magnetic recording media, there can be obtained a magnetic tape which can be in good contact with the magnetic head and which is accompanied by little abrasion of the magnetic powder and little modulation noise in use and has high durability. TABLE 2__________________________________________________________________________Magnetic coating materialCured magnetic coating film Cured transparent filmRefer-Filtra- THF-entialtion test Abrasion Ratio of Strength Initial unextractableExampleusing 2μ Surface Adhesion test rectangular Bending at break Elongation modulus residueNo. filter Gloss state test (mg) hysteresis test (kg/cm.sup.2) (%) (kg/cm.sup.2) (%)__________________________________________________________________________1 Filtered ⊚ ⊚ ⊚ 0.7 0.87 Excellent 450 150 5,700 97.4within1 minute2 Filtered ⊚ ○ 0.8 0.84 Good 360 190 4,200 94.8within1 minute3 Filtered ⊚ ⊚ ⊚ 0.4 0.86 Excellent 560 83 10,000 98.3within1 minute4 Filtered ⊚ ⊚ ⊚ 0.8 0.87 Excellent 480 150 1,600 95.1within1 minute5 Filtered ⊚ ⊚ ○ 0.7 0.86 Excellent 460 210 5,000 95.0within1 minute6 Filtered ⊚ ○ ⊚ 0.4 0.84 Good 500 170 6,300 95.2within1 minute7 Filtered ⊚ ⊚ ⊚ 0.5 0.89 Excellent 410 330 2,800 96.0within1 minute8 Filtered ⊚ ○ ○ 0.8 0.85 Good 430 90 14,000 98.8within1 minute9 Filtered ⊚ ⊚ ⊚ 0.5 0.88 Good 500 130 7,300 97.9within1 minute10 Filtered ⊚ ⊚ ○ 1.0 0.87 Good 390 240 880 95.4within1 minute11 Filtered ⊚ ○ ⊚ 0.6 0.83 Excellent 610 68 13,000 99.4within1 minute12 Filtered ⊚ ⊚ ⊚ 0.4 0.86 Excellent 430 120 8,200 97.3within1 minute13 Filtered ⊚ ⊚ ⊚ 0.8 0.85 Excellent 360 230 900 94.1within1 minute14 Filtered ⊚ ⊚ ○ 0.9 0.83 Good 390 260 4,000 96.2within1 minute__________________________________________________________________________

There is disclosed acrylate-terminated oligomers which are radiation-curable and which can be pigmented with magnetizable power to cure on electron beam exposure to provide superior magnetic recording structures. These oligomers include sulfonic acid groups which improve pigment wetting and which can be included in amide-containing compounds.

ORIGIN OF THE INVENTION The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457). BACKGROUND OF THE INVENTION This invention relates generally to aircraft flight instruments and in particular to aircraft control position indicators (ACPI). During stall/spin tests conducted at NASA Langley Research Center, it became apparent that the existing aircraft control position indicators (ACPI) were inadequate. Such stall/spin tests are conducted in order to determine the flight characteristics of aircraft in spins entered into after stalling has occurred. While in the spin, the aircraft descends rapidly with a helical motion about its spin axis. These tests subject the pilot and the aircraft flight instruments to strong centrifugal and gravitational forces. The effect on the pilot is to make head and eye positioning difficult. The effect on the flight control indicators is to cause drift and other inaccuracies. The pilot in a spin test needs an instantaneous display of the exact position of the control surfaces in order to follow a predetermined flight plan and prevent drifting of the controls from their desired position. The display must be visible under all cockpit conditions and can require only a minimum of mental effort for its interpretation. The gyro horizon devices currently used in aircraft are unsuitable for spin/stall tests. They provide the pilot with only an indirect indication of the positions of the aileron, elevator, and rudder control surfaces. These devices depend on gyroscopes mounted within the aircraft and are attitude indicators, in that they display the orientation of the aircraft relative to the natural horizon. The gyroscopes are adversely affected by the centrifugal forces and there is some lag between the actual attitude of the aircraft and the attitude as shown on the display. This type of device therefore does not allow rapid and precise repositioning of the control surfaces according to a test flight plan. Another flight instrument experimented with was a mechanical edge-type meter. These meters have a display that includes a scale and a moving needle. The position of the needle on the scale indicates the position of the control surface over its range. This device is unsuitable because the needle tends to bounce as the aircraft flies and is subject to overshoot when the aircraft changes attitude. It is therefore an object of this invention to provide an aircraft control position indicator (ACPI) that communicates to the pilot the instantaneous position of the major control surfaces with no tendency toward overshoot. It is also the object of this invention to present the control surface position information in a manner so as to minimize the mental effort required for the pilot to interpret the display during complicated and stressful maneuvers. It is a further object of this invention to provide an aircraft control position indicator that is not affected by gravitational and centrifugal forces. Another object of this invention is to provide a means for rapidly and precisely repositioning aircraft controls according to a predetermined flight plan. Still another object of this invention is to provide an aircraft flight instrument display that is visible to the pilot under all cockpit lighting conditions. Other objects will be apparent from the detailed description when read with reference to the accompanying drawings. SUMMARY OF THE INVENTION The above listed objects are attained through the practice of the present invention. The form of the ACPI aids the pilot in interpreting the information about the aircraft control surface positions and so minimizes the pilot's mental workload. In the embodiment showing the aileron, elevator, and rudder positions, the display of the ACPI actually approximates the shape of an aircraft. An upper horizontal dot/bar graph display of the ACPI is suggestive of the wings of an aircraft and represents the range of positions possible for the ailerons, which are located on the wing surface. If the display is actuated on the right-hand portion of the dot/bar graph display the aircraft will roll to the right and if the display is on the left portion, the aircraft will roll to the left. A lower horizontal dot/bar graph display of the ACPI suggests the rear portion of an aircraft and represents the range of possible deflections for the rudder, which is located at the rear of the aircraft. If the display is actuated on the right portion of this dot/bar graph display the aircraft will turn right, and if the display is actuated on the left portion, the aircraft will turn left. A vertical dot/bar graph display, which is effectively divided into an upper and a lower portion by the aileron dot/bar graph display, represents the range of possible positions for the elevators, which control the pitch of the aircraft. If the display is actuated on the upper portion of the dot/bar graph display the aircraft will pitch upward, and if the display is actuated on the lower portion, the aircraft will pitch downward. The position of the display within the dot/bar graph display indicates the degree of deflection of the particular control surface associated with that display. The center of each display indicates the neutral, or undeflected position, and the ends of the displays indicate maximum deflections. The display may be actuated (for example, illuminated) at any position along the dot/bar graph display. The ACPI may consist solely of the aileron bar graph display and the elevator bar graph display. This ACPI is simpler to interpret because of the smaller amount of information conveyed. No one of the three dot/bar graph displays is essential to this invention. All subcombinations are envisioned to be within its scope. The display significantly reduces the mental effort required for the pilot to interpret the display and reposition the control surfaces according to a predetermined flight plan. Because the device is totally electronic, it is not adversely affected by gravitational and centrifugal forces. The inputs to the device are voltage signals from transducers measuring the control surface deflections. These electrical signals produce no appreciable lag time, and so the display is almost instantaneous. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an embodiment of the aircraft control position indicator permitting position for the ailerons, elevators, and rudder. FIG. 2 is a block diagram partially showing the inputs to a system within the contemplation of the present invention, and specifically the ACPI of FIG. 1; FIG. 3 is a partial electrical diagram of the ACPI showing an example of circuitry that may be used to process an input from, for example, the elevator while similar circuits may be used to process inputs from the aileron and rudder control surfaces. DETAILED DESCRIPTION OF THE INVENTION An illustrative embodiment of the invention is shown in FIG. 1. This embodiment displays to the pilot the position of the ailerons, the elevators, and the rudder control surfaces. The reference numeral 10 designates the ACPI (Aircraft Control Position Indicator) in general. The ACPI 10 is contained within a rectangular instrument case 12. A rectangular plate 14 or dot/bar graph display is secured to the forward facing surface of the instrument case 12 and is cut to expose the display area (shown in cross hatch, with a vertical column being intersected by a pair of horizontal rows) formed by a plurality of dot/bar graph displays. In this embodiment, the display is a plurality of illuminating elements such as light emitting diodes (LEDs). The LEDs may be arranged in single rows and columns, in plural rows and columns or in any other combination or manner. Other suitable devices or illuminating elements may be employed, and the the only requirement is that some indication, by illumination or otherwise, be visible so as to disclose the amount of the deflection of the aircraft control surfaces. In the illustrative embodiment of the FIG. 1, the ACPI 10 comprises a vertical column of illuminating elements or LEDs 52 intersected by two spaced apart horizontal rows of illuminating elements or LEDs 50 and 54. The illumination from the LEDs is visible through the portion of the rectangular plate 14 that is removed (this portion being shown in cross hatch outline of the FIG. 1). The vertical column 52 of the display comprises, from top to bottom of the ACPI 10 of the FIG. 1, an upper bar of LEDs 24, a large lamp diode 16, a lower bar of LEDs 26, and a large lamp 18, The upper horizontal row 50 intersects the vertical column 52 at the lamp 16, which is between the upper bar of LEDs 24 and the lower bar of LEDs 26. More specifically, the upper horizontal row 50 includes, from left to right, an upper left bar of LEDs 28, a small lamp diode 20, the large lamp diode 16, a small lamp diode 22 and an upper right bar of LEDs 30. The second and lower horizontal row 54 forms an inverted "T". With the vertical column of LEDs 52 and comprises, from left to right, a lower left bar of LEDs 32, the large lamp diode 18, and a lower right bar of LEDs 34. The vertical column of LEDs 52, excluding the lamp diode 18, represents the range of possible deflections for the aircraft elevators. When the lamp 16 at the center of the column 52 is activated, the elevators are in their neutral, or undeflected position. If a diode on the upper bar of diodes 24 is activated, the elevators are deflected upward into the stream of air flowing over the wing surface and the aircraft will pitch upward. An activated diode at the very top of the upper bar of LEDs 24 indicates that the elevators are deflected upward to the maximum extent possible. Similarly, an activated diode on the lower bar of diodes 26 indicates that the elevator surface of the aircraft is deflected downward, and that the aircraft will therefore pitch down. An activated diode at the lowest portion of the lower bar of diodes 26 indicates that the elevators have been deflected downward from the neutral to the maximum possible extent. The upper horizontal row 50 formed by the light emitting diodes 28, 20, 16, 22 and 30 represent the range of possible deflections for the ailerons. The Lamp 16 has no function where the ailerons are concerned. The neutral position of the ailerons is instead indicated by the small lamp diodes 20 and 22, which may be lighted as a pair. A light on the upper left bar diodes 28 indicates that the left aileron is deflected upward and the right aileron is deflected downward, and that the aircraft will therefore roll to the left. A light on the upper right bar of diode 30 indicates that the left aileron has been deflected downward and the right aileron has been deflected upward producing a rolling moment of the aircraft to the right. A light at the extreme left or at the extreme right of the row indicates that the ailerons have been deflected, one up and one down, to the maximum possible extent. The lower horizontal row 54 formed by the lower left bar of diodes 32, the lamp diode 18, and the lower right bar of diodes 34 represent the range of possible rudder deflections. If the lamp 18 is activated, the rudder is in the undeflected position. If a diode on the lower left bar of diodes 32 is activated, the rudder is deflected to the left and the aircraft will turn left. If a diode on the lower right bar of diodes 34 is activated, the rudder has been deflected to the right, thus, producing a right turn of the vehicle. A light at either the extreme left or extreme right of the lower horizontal row 54 indicates that the rudder has been deflected to the maximum allowable extent. FIG. 2 is a block diagram showing the mode of operation of the embodiment of the invention shown in FIG. 1. Measurements are taken by an aileron transducer 36, an elevator transducer 38, and a rudder transducer 40 linked in a conventional manner to the aircraft control surfaces. These transducers produce analog voltage signals that are input to the ACPI 10 through a connector 42. Once inside the ACPI 10, the control surface signals are applied to a plurality of analog voltage decoder/divider and display drivers 44, 46, 48 which activate, respectively, diodes of the rows and column of light emitting diodes 50, 52, and 54. A partial electric circuit diagram of the embodiment of the invention shown in FIG. 1 is shown in the FIG. 3. For illustration purposes, the circuitry is for processing the elevator signal, but substantially identical circuits can be used for processing the rudder and aileron portions of the display. The connector 42 provides the inlet for the elevator signal, as well as the rudder and aileron signals and the power and ground sources. A potentiometer 56 allows the display range of the analog voltage decoder/divider and display driver 46 formed by the combination of an integrated circuit 58 and an integrated circuit 60 to be adjusted to match the range of the input voltage. A wiper 62 of the potentiometer 56 carries the input signal to the integrated circuits 58 and 60. A variable resistor 64 allows the output of the voltage decoder/divider and display driver 46 to be adjusted so that a voltage at the center of the input range activates the lamp diode at the center of the column. The ACPI 10 is properly adjusted when full deflection of the control surface, in one direction through its respective transducer 38 of the FIG. 2, activates a diode(s) at one end of the display and full deflection of the control surface in the opposite direction, activates a diode(s) in the opposite end of the display. A pair of resistors 66 and 68 control the current applied to the light emitting diodes and so the brightness of the display, and a pair of capacitors 70 and 72 are bypass capacitors to eliminate oscillation. A resistor 74 couples the integrated circuit 58 the to the integrated circuit 60. A voltage regulator 76 receives the power input from the connector 42 and generates an output voltage sent to one terminal of all the light emitting diodes. The heat generated by the voltage regulator 76 is dissipated by a heat sink 78. Reference numbers 80 and 82 denote the bypass capacitors for the voltage regulator 76. The ground signal generated by the analog voltage decoder/divider and display driver 46 at one of the outlet ports causes current to flow across the diode linked to that output and so activates one of the light emitting diodes. FIG. 3 further shows two alternatives for the circuitry controlling the center of each row of light emitting diodes. A single lamp diode, such as the large lamp diode 16 of the FIG. 1, is used to indicate the center of the column of LEDs 52 for the elevator and the row of LEDs 54 for the rudder control surfaces. For the aileron row of LEDs 50, two lamp diodes, such as small lamp diodes 20 and 22 in FIG. 1, are placed in electrical parallel and so activated as a pair by a single ground signal from the voltage decoder/divider and display driver 46. The integrated circuits 58 and 60 in FIG. 3 are each a dot/bar display driver that is commercially available. The integrated circuits are available from National Semiconductor Corporation as LM 3914 Dot/Bar Display Drivers. These drivers have two modes of operation: In a dot mode of operation only one of the LEDs is illuminated at any given time and in a bar mode of operation more than one of the LEDs can be illuminated at a time. Even though either mode of operation can be used with this invention the invention has been described as utilizing the dot mode of operation. In the dot mode of operation each integrated circuit includes two voltage dividers with each divider including ten resistors connected in series. Hence, each divider will divide the voltage applied to it into ten different voltage levels. The voltage from wiper 62 is applied to a first of the voltage dividers and a constant voltage from connection A of connector 42 is applied to the second voltage divider. The function of the second voltage divider is to produce a set of reference voltages. Ten "comparator" circuits are each connected to a corresponding resistor junction of the two voltage dividers to compare the voltages at the corresponding resistor junctions. Whenever, two corresponding junctions have the same voltage the corresponding "comparator" circuit conducts and gates the corresponding LED to ground thereby illuminating the LED. Integrated circuit 58 controls the ten LEDs in the upper bar of diodes 24 and integrated circuit 60 controls LED 22 and the first nine LEDs in lower bar of diodes 26. OPERATION Transducers of any type known in the art may be linked to each control surface to generate an analog voltage signal that corresponds to the deflection of the control surface over its range. The signal from transducer 38 representing the deflection of the elevator is applied through connection C of connector 42 to potentiometer 62. The resulting signal at the wiper 62 is applied to both of the integrator circuits 58 and 60 to illuminate one and only one of the LEDs in the column of LEDs 52. The position of the illuminated LED indicates the deflection of the elevator. The signal from transducer 40 representing the deflection of the rudder is applied through connection E of connector 42 to a second circuit like the one disclosed in FIG. 3 to illuminate a second LED in the row of LEDs 54. The position of the second illuminated LED indicates the deflection of the rudder. The signal from transducer 36 representing the deflection of the aileron is applied through connection D of connector 42 to a third circuit like the one disclosed in FIG. 3 to illuminate a third LED in the row of LEDs 50. The position of the illuminated LED indicates the deflection of the aileron. In this third circuit the two LEDs 20 and 22 are used in place of the single LED 16 to represent the neutral deflection of the aileron. As is evident from the description in conjunction with the figures, the aircraft control position indicator of the present invention fills a flight research display that other flight instruments cannot satisfy. The test pilot controlling the aircraft in a spin has only to watch the position of a few lights on a simple display pattern to reposition the primary flight control surfaces according to a predetermined flight plan. The pilot is assured that the display is accurate because the electronic circuitry is not affected by the centrifugal and gravitational forces and because of the absence of lag time between the measurement transducer and the display. The device further allows the pilot to check the primary control surfaces during flight to ensure they are responding properly to the cockpit controls. For instance, cable stretching causes the rudder to be only partially deflected when the cockpit rudder control may indicate maximum deflection. The value of the present invention is that it informs the pilot of the actual deflection of the control surface, not of the deflection that the controls are set to produce, and so provides a means of comparison between the two. It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment. Various changes may be made without departing from the invention. For example, circuitry other than that shown in FIG. 3 for performing the function of FIG. 3 could be used. That is, any circuitry that will select, in accordance with the amplitude of an electrical signal, a single light to be illuminated in a row of lights could be substituted for FIG. 3.

An aircraft control position indicator is provided that displays the degree of deflection of the primary flight control surfaces and the manner in which the aircraft will respond. The display includes a vertical elevator dot/bar graph meter display for indicating whether the aircraft will pitch up or down, a horizontal aileron dot/bar graph meter display for indicating whether the aircraft will roll to the left or the right, and a horizontal rudder dot/bar graph meter display for indicating whether the aircraft will turn left or right. The vertical and horizontal display or displays intersect to form an up-down-left-right type display. Internal electronic display driver means receive signals from transducers measuring the control surface deflections and determine the position of the meter indicators one each dot/bar graph meter display. The device allows readability at a glance, easy visual perception in sunlight or shade, near-zero lag in displaying flight control position, and is not affected by gravitational or centrifugal forces.

FIELD OF THE INVENTION [0001] The present invention relates to the field of distribution and usage rights enforcement for digitally encoded works, and in particular to identification of non-authorized copies of digitally encoded works that have been rendered. BACKGROUND OF THE INVENTION [0002] Pending U.S. patent application Ser. No. 08/344,042 filed Nov. 29, 1996, incorporated herein by reference, describes a system which provides for the secure and accounted for distribution of digitally encoded works (hereinafter digital works). However, once a digital work leaves the digital domain, e.g. it is printed out, played or otherwise rendered, it is not longer secure and can be subjected to unauthorized copying. This is a problem for all rendered digital works. [0003] Two known techniques for protecting digital works by imparting information onto the digital document are “watermarking” and “fingerprinting”. The term watermark historically refers to a translucent design impressed on paper during manufacture which is visible when the paper is held to the light. Because watermarks are impressed using combinations of water, heat, and pressure, they are not easy to add or alter outside of the paper factory. Watermarks are used in making letterheads and are intended to indicate source and that a document is authentic and original and not a reproduction. [0004] One technique for creating such a watermark when a digital work is printed is described in U.S. Pat. No. 5,530,759 entitled “Color Correct Digital Watermarking of Images” issued Jun. 25, 1996. In this approach the watermark image is combined with the digital image to created the watermarked image. The watermark image acts as a template to change the chromacity of corresponding pixels in the digital image thus creating the watermark. In any event, these notices server as social reminders to people to not make photocopies. [0005] The term watermark is now used to cover a wide range of technologies for marking rendered works, including text, digital pictures, and digital audio with information that identifies the work or the publisher. Some watermarks are noticeable to people and some are hidden. In some kinds of watermarks, the embedded information is human readable, but in other kinds the information can only be read by computers. [0006] The term fingerprint is sometimes used in contrast with watermarks to refer to marks that carry information about the end user or rendering event rather than the document or publisher. These marks are called “fingerprints” because they can be used to trace the source of a copy back to a person or computer that rendered the original. [0007] The same technologies and kinds of marks can be used to carry both watermark and fingerprint information. In practice, it is not only possible but often desirable and convenient to combine both kinds of information—for watermarks and fingerprints—in a single mark. [0008] With respect to paper based documents, the simplest approach to providing a mark is a graphical symbol or printed notice that appears on each page. This is analogous to a copyright notice. Such notices can be provided by the publisher in the document source or added later by a printer. These notices serve as social reminders to people to not make photocopies. [0009] Other approaches hide information in the grey codes (or intensity) on a page. Although in principle such approaches can embed data in greycode fonts, their main application so far has been for embedding data in photographs. One set of approaches is described by Cox et al. in a publication entitled “Secure spread spectrum watermarking for Multimedia”, NEC Research Institute Technical Report 95-10, NEC Research Institute, Princeton, N.J. 08540. To decode data encoded in the approached described by Cox et al. requires comparing the encoded picture with the original to find the differences. The advantage of these approaches is that they can embed the data in such a way that it is very difficult to remove, not only by mechanical means but also by computational means. [0010] As described above, watermarks need not be perceptible to the viewer. For example, one technique is to embed data in the white space of a document. An example of this kind of approach was described by Brassil, et al. In a publication entitled “Electronic marking and identification techniques to discourage document copying”, IEEE Journal on Selected Areas in Communications, Vol. 13, No. 8 pages 1495-1504, October 1995. The idea is to slightly vary the spacing of letters and lines in a digital work. The advantages of this approach are that it is not visible and is hard to remove. The disadvantage is that it has a very limited capacity for carrying data—only a few bytes per page. [0011] Another watermarking scheme for use in digital works representing images is available from the Digimarc Corporation. The Digimarc watermark is invisible and is used to convey ownership information relating to the image. From the Digimarc World Web Page describing their technology (URL http://www.digimarc.com/wt_page.html): “A Digimarc watermark imitates naturally occurring image variations and is placed throughout the image such that it cannot be perceived. To further hide the watermark, the Digimarc watermarking process is perceptually adaptive—meaning it automatically varies the intensity of the watermark in order to remain invisible in both flat and detailed areas of an image.” Reading of the Digimarc watermark is through a Digimarc reader which can extract the watermark from the image. [0012] Other prior art relating to embedding data in a print medium includes Daniele, U.S. Pat. No. 5,444,779, on “Electronic Copyright Royalty Accounting System for Using Glyphs”, which discloses a system for utilizing a printable, yet unobtrusive glyph or similar two-dimensionally encoded mark to identify copyrighted documents. Upon attempting to reproduce such a document, a glyph is detected, decoded and used to accurately collect and/or record a copyright royalty for the reproduction of the document or to prevent such reproduction. Furthermore, the glyph may also include additional information so as to enable an electronic copyright royalty accounting system, capable of interpreting the encoded information to track and/or account for copyright royalties which accrue during reproduction of all or portions of the original document. SUMMARY OF THE INVENTION [0013] A trusted rendering system for use in a system for controlling the distribution and use of digital works is disclosed. The currently preferred embodiment of the present invention is implemented as a trusted printer. However, the description thereof applies to any rendering device. A trusted printer facilitates the protection of printed documents which have been printed from a system which controls the distribution and use of digital works. The system for controlling distribution and use of digital works provides for attaching persistent usage rights to a digital work. Digital works are transferred in encrypted form between repositories. The repositories are used to request and grant access to digital works. Such repositories are also coupled to credit servers which provide for payment of any fees incurred as a result of accessing a digital work. [0014] The present invention extends the existing capabilities of the system for controlling distribution and use of digital works to provide a measure of protection when a document is printed. The present invention adds to the system the ability to include watermark information to a document when it is rendered (i.e. a Print right associated with the document is exercised). In the currently preferred embodiment of a trusted printer, the watermark is visible. However, other “invisible” watermarking technologies may also be used. The watermark data typically provides information relating to the owner of a document, the rights associated with that copy of the document and information relating to the rendering event (e.g. when and where the document was printed). This information will typically aid in deterring or preventing unauthorized copying of the rendered work. It is worth noting that the present invention further provides for multiple types of watermarks to be provided on the same digital work. [0015] Specification of the watermark information is preferably added to a document at the time of assigning render or play rights to the digital work. With respect to printed digital works, at the time of page layout special watermark characters are positioned on the document. When the document is printed, a dynamically generated watermark font is created which contains the watermark information specified in the print right. The font of the watermark characters are changed to the dynamically generated watermark font. The dynamically generated watermark font is created using an embedded data technology such as the glyph technology developed by the Xerox Corporation and described in U.S. Pat. No. 5,486,686 entitled “Hardcopy Lossless Data Storage and Communications For Electronic Document Processing Systems”, which is assigned to the same assignee as the present application. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a block diagram illustrating the basic interaction between repository types in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention. [0017] FIG. 2 is an illustration of a repository coupled to a credit server for reporting usage fees as may be used in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention. [0018] FIG. 3 a is an illustration of a printer as a rendering system as may be utilized in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention. [0019] FIG. 3 b is a block diagram illustrating the functional elements of a trusted printer repository in the currently preferred embodiment of the present invention. [0020] FIG. 4 is a flowchart of the basic steps for digital work creation for printing on a trusted printer as may be performed in the currently preferred embodiment of the present invention. [0021] FIG. 5 is an illustration of a usage rights specification for a digital work that may be printed on a user's trusted printer in the currently preferred embodiment of the present invention. [0022] FIG. 6 is an illustration of a usage rights specification for a digital work that may only be printed on a shared trusted printer residing on a network in the currently preferred embodiment of the present invention. [0023] FIG. 7 is an illustration of a printed page having a glyph encoded watermark. [0024] FIG. 8 is an illustration of a set of sample embedded data boxes having different storage capacities as may be used as watermark characters of a watermark font set in the currently preferred embodiment of the present invention. [0025] FIG. 9 is an illustration of a print right having the watermark information specified as may be used set in the currently preferred embodiment of the present invention. [0026] FIG. 10 is a flowchart summarizing the basic steps for a creator to cause watermarks to be placed in their documents as may be performed in the currently preferred embodiment of the present invention. [0027] FIG. 11 is a flowchart of the steps required for printing a document as may be performed in the currently preferred embodiment of the present invention. [0028] FIG. 12 is a flowchart outlining the basic steps for extracting the embedded data as may be performed in the currently preferred embodiment of the present invention. [0029] FIG. 13 is an illustration of an implementation of the present invention as a trust box coupled to a computer based system. [0030] FIG. 14 is a flowchart illustrating the steps involved in printing a digital work using the trust box implementation of FIG. 13 . [0031] FIG. 15 is an illustration of an implementation of the present invention as a printer server. [0032] FIG. 16 is a flowchart illustrating the steps involved in printing a digital work using the printer server implementation of FIG. 15 . DETAILED DESCRIPTION OF THE INVENTION [0033] A trusted rendering device for minimizing the risk of unauthorized copying of rendered digital works is described. The risk of unauthorized copying of digital documents comes from three main sources: interception of digital copies when they are transmitted (e.g., by wiretapping or packet snooping); unauthorized use and rendering of digital copies remotely stored, and unauthorized copying of a rendered digital work. The design of trusted rendering devices described herein addresses all three risks. [0034] Trusted rendering combines four elements: a usage rights language, encrypted on-line distribution, automatic billing for copies, and digital watermarks for marking copies that are rendered. Usage Rights language. Content providers indicate the terms, conditions, and fees for printing documents in a machine-readable property rights language. Encrypted Distribution. Digital works are distributed from trusted systems to trusted rendering devices via computer networks. To reduce the risk of unauthorized interception of a digital work during transmission, it is encrypted. Communication with the rendering system is by way of a challenge-response protocol that verifies the authorization and security of the rendering device. Automatic Billing. To ensure a reliable income stream to content providers, billing of royalties is on-line and automatic. Watermarks. Finally, to reduce the risk of copying of rendered works, the rendered work is watermarked to record data about the digital work and the rendering event. Furthermore, watermarks are designed to make copies distinguishable from originals. As will be described below, watermark information is specified within a rendering or play right in the usage rights language. [0039] The currently preferred embodiment of the present invention is implemented as a trusted printer. The foregoing description will be directed primarily to printers, but the concepts and techniques described therein apply equally to other types of rendering systems such as audio players, video players, displays or multi-media players. Overview of a System for Controlling the Distribution and Use of Digital Works. [0040] The currently preferred embodiment of the present invention operates in a system for controlling the distribution and use of digital works is as described in co-pending U.S. patent application Ser. No. 08/344,042, entitled “System for Controlling the Distribution and Use of Digital Works” and which is herein incorporated by reference. A digital work is any written, audio, graphical or video based work including computer programs that have been translated to or created in a digital form, and which can be recreated using suitable rendering means such as software programs. The system allows the owner of a digital work to attach usage rights to the work. The usage rights for the work define how it may be used and distributed. Digital works and their usage rights are stored in a secure repository. Digital works may only be accessed by other secure repositories. A repository is deemed secure if it possesses a valid identification (digital) certificate issued by a Master repository. [0041] The usage rights language for controlling a digital work is defined by a flexible and extensible usage rights grammar. The usage rights language of the currently preferred embodiment is provided in Appendix A. Conceptually, a right in the usage rights grammar is a label attached to a predetermined behavior and defines conditions to exercising the right. For example, a COPY right denotes that a copy of the digital work may be made. A condition to exercising the right is the requester must pass certain security criteria. Conditions may also be attached to limit the right itself. For example, a LOAN right may be defined so as to limit the duration of which a work may be LOANed. Conditions may also include requirements that fees be paid. [0042] A repository is comprised of a storage means for storing a digital work and its attached usage rights, an external interface for receiving and transmitting data, a processor and a clock. A repository generally has two primary operating modes, a server mode and a requester mode. When operating in a server mode, the repository is responding to requests to access digital works. When operating in requester mode, the repository is requesting access to a digital work. [0043] Generally, a repository will process each request to access a digital work by examining the work's usage rights. For example, in a request to make a copy of a digital work, the digital work is examined to see if such “copying” rights have been granted, then conditions to exercise the right are checked (e.g. a right to make 2 copies). If conditions associated with the right are satisfied, the copy can be made. Before transporting the digital work, any specified changes to the set of usage rights in the copy are attached to the copy of the digital work. [0044] Repositories communicate utilizing a set of repository transactions. The repository transactions embody a set of protocols for establishing secure session connections between repositories, and for processing access requests to the digital works. Note that digital works and various communications are encrypted whenever they are transferred between repositories. [0045] Digital works are rendered on rendering systems. A rendering systems is comprised of at least a rendering repository and a rendering device (e.g. a printer, display or audio system). Rendering systems are internally secure. Access to digital works not contained within the rendering repository is accomplished via repository transactions with an external repository containing the desired digital work. As will be described in greater detail below, the currently preferred embodiment of the present invention is implemented as a rendering system for printing digital works. [0046] FIG. 1 illustrates the basic interactions between repository types in the present invention. As will become apparent from FIG. 1 , the various repository types will serve different functions. It is fundamental that repositories will share a core set of functionality which will enable secure and trusted communications. Referring to FIG. 1 , a repository 101 represents the general instance of a repository. The repository 101 has two modes of operations; a server mode and a requester mode. When in the server mode, the repository will be receiving and processing access requests to digital works. When in the requester mode, the repository will be initiating requests to access digital works. Repository 101 may communicate with a plurality of other repositories, namely authorization repository 102 , rendering repository 103 and master repository 104 . Communication between repositories occurs utilizing a repository transaction protocol 105 . [0047] Communication with an authorization repository 102 may occur when a digital work being accessed has a condition requiring an authorization. Conceptually, an authorization is a digital certificate such that possession of the certificate is required to gain access to the digital work. An authorization is itself a digital work that can be moved between repositories and subjected to fees and usage rights conditions. An authorization may be required by both repositories involved in an access to a digital work. [0048] Communication with a rendering repository 103 occurs in connection with the rendering of a digital work. As will be described in greater detail below, a rendering repository is coupled with a rendering device (e.g. a printer device) to comprise a rendering system. [0049] Communication with a master repository 105 occurs in connection with obtaining an identification certificate. Identification certificates are the means by which a repository is identified as “trustworthy”. The use of identification certificates is described below with respect to the registration transaction. [0050] FIG. 2 illustrates the repository 101 coupled to a credit server 201 . The credit server 201 is a device which accumulates billing information for the repository 101 . The credit server 201 communicates with repository 101 via billing transaction 202 to record billing transactions. Billing transactions are reported to a billing clearinghouse 203 by the credit server 301 on a periodic basis. The credit server 201 communicates to the billing clearinghouse 203 via clearinghouse transaction 204 . The clearinghouse transactions 204 enable a secure and encrypted transmission of information to the billing clearinghouse 203 . Rendering Systems [0051] A rendering system is generally defined as a system comprising a repository and a rendering device which can render a digital work into its desired form. Examples of a rendering system may be a computer system, a digital audio system, or a printer. In the currently preferred embodiment, the rendering system is a printer. In any event, a rendering system has the security features of a repository. The coupling of a rendering repository with the rendering device may occur in a manner suitable for the type of rendering device. [0052] FIG. 3 a illustrates a printer as an example of a rendering system. Referring to FIG. 3 a, a printer system 301 has contained therein a printer repository 302 and a print device 303 . It should be noted that the dashed line defining printer system 301 defines a secure system boundary. Communications within the boundary is assumed to be secure and in the clear (i.e. not encrypted). Depending on the security level, the boundary also represents a barrier intended to provide physical integrity. The printer repository 302 is an instantiation of the rendering repository 105 of FIG. 1 . The printer repository 302 will in some instances contain an ephemeral copy of a digital work which remains until it is printed out by the print engine 303 . In other instances, the printer repository 302 may contain digital works such as fonts, which will remain and be billed based on use. This design assures that all communication lines between printers and printing devices are encrypted, unless they are within a physically secure boundary. This design feature eliminates a potential “fault” point through which the digital work could be improperly obtained. The printer device 303 represents the printer components used to create the printed output. [0053] Also illustrated in FIG. 3 a is the repository 304 . The repository 304 is coupled to a printer repository 302 . The repository 304 represents an external repository which contains digital works. [0054] FIG. 3 b is a block diagram illustrating the functional elements of a trusted printer repository. Note that these functional elements also would be present in any rendering repository. Referring to FIG. 3 b, the functional embodiment is comprised of an operating system 310 , core repository services 311 , and print repository functions 312 . The operating system 310 is specific to the repository and would typically depend on the type of processor being used to implement the repository. The operating system 1301 would also provide the basic services for controlling and interfacing between the basic components of the repository. [0055] The core repository services 311 comprise a set of functions required by each and every repository. For a trusted printer repository the core repository services will include engaging in a challenge response protocol to receive digital works and decryption of received digital data. [0056] The print repository functions 312 comprise functionality for rendering a work for printing as well as gathering data for and creating a digital watermark. The functionality unique to a print repository will become apparent in the description below (particularly with respect to the flowchart of FIG. 11 ). Basic Steps for Digital Work Creation for Printing on a Trusted Printer [0057] FIG. 4 is a flowchart illustrating the basic steps for creating a digital work that may be printed on a trusted printer so that the resulting printed document is also secure. Note that a number of well known implementation steps, e.g. encryption of digital works, have been omitted in order to not detract from the basic steps. First, a digital work is written, assigned usage rights including a print right which specifies watermark information and is deposited in repository 1 , step 401 . As will be described in more detail below, the assignment of usage rights is accomplished through the use of a rights editor. Deposit of the digital work into repository 1 is an indication that it is being placed into a controlled system. Next, repository 1 receives a request from repository 2 for access to the digital work, step 402 and repository 1 transfers a copy of the digital work to repository 2 , step 403 . For the sake of this example, it is assumed that a “trusted” session between repository 1 and repository 2 has been established. The challenge response protocol used in this interaction is described in co-pending application Ser. No. 08/344,042 and thus no further discussion on the challenge response protocol is deemed necessary. [0058] Repository 2 then receives a user request to print the digital work, step 404 . Repository 2 then establishes a trusted session with a printer repository of the printing system on which the digital work will be printed, step 405 . The printer repository receives the encrypted digital work and determines if it has a print right, step 406 . If the digital work has the print right, the printer repository decrypts the digital work and generates the watermark that will be printed on the digital work, step 407 . The printer repository then transmits the decrypted digital work with the watermark to a printer device for printing, step 408 . For example, the decrypted digital work may be a Postscript™ file of the digital work. [0000] Controlling Printing with the Usage Rights Grammar A key concept in governing sale, distribution, and use of digital works is that publishers can assign “rights” to works that specify the terms and conditions of use. These rights are expressed in a rights language as described in co-pending application Ser. No. 08/344,042. The currently preferred grammar is provided herein in Appendix A. It is advantageous to specify watermark information within a rendering or play right within the grammar for a number of reasons. First, specification in this manner is technology independent. So different watermarking technologies may be used or changed without altering the document. Second, multiple watermarking technologies may be applied to the same digital work, e.g. a visible watermarking technology and an invisible watermarking technology. So if the visible watermark is removed, the invisible one may remain. Third, the watermark information to be placed on the digital work can be associated with the rendering event, rather than the distribution event. Fourth, the watermark information can be extended to include the entire distribution chain of the digital work. Fifth, security and watermarking capabilities of a rendering system may be specified as a condition rendering. This will further insure the trusted rendering of the digital work. [0059] As a result of these advantages, this type of specifying watermark information fully supports the Superdistribution of digital works. Superdistribution is distribution concept where every possessor of a digital work may also be a distributor of the digital work, and wherein every subsequent distribution is accounted for. [0060] When a publisher assigns rights to a digital work, the usage rights enables them to distinguish between viewing (or playing) rights and print rights. Play rights are used to make ephemeral, temporary copies of a work such as an image of text on a display or the sound of music from a loudspeaker. Print rights are used to make durable copies, such as pages from a laser printer or audio recordings on a magnetic media. [0000] Example—Trusted Printing from a Personal Computer [0061] FIG. 5 is an example of the usage rights for a digital work which enables trusted printing from a personal computer. Referring to FIG. 5 , various tags are used in for the digital work. The tags “Description” 501 , “Work-ID” 502 and “Owner” 503 provide identification information for the digital work. [0062] Usage rights are specified individually and as part of a group of rights. The Rights-Group 504 has been given a name of “Regular”. The bundle label provides for a fee payee designation 505 and a minimum security level 506 that are applied to all rights in the group. The fee payee designation 505 is used to indicate who will get paid upon the invocation of a right. The minimum security level 506 is used to indicate a minimum security level for a repository that wishes to access the associated digital work. [0063] The rights in the group are then specified individually. The usage rights specify no fee for transferring 508 , deleting 509 or playing 510 , but does have a five dollar fee for making a digital copy 507 . It also has two Print rights 511 and 512 , both requiring a trusted printer (specified by 513 ) The first Print right 511 can be exercised if the user has a particular prepaid ticket (specified by 514 ). The second print right has a flat fee of ten dollars (specified by 515 ). The example assumes that the digital work can be transmitted to a user's computer by exercising the Copy right, and that the user can play or print the work at his or her convenience using the Play and Print rights. Fees are logged from the user's workstation whenever a right is exercised. [0064] Also illustrated in FIG. 5 are watermark specifications 516 and 517 . The particular detail for the watermark specifications 516 and 517 is provided below with reference to FIG. 9 . Example—Trusted Printing to an Internet Printer [0065] FIG. 6 illustrates a different set of rights for the same digital book. In this version, the publisher does not want digital delivery to be made to a consumer workstation. A practical consideration supporting this choice may be that the publisher wants to minimize the risk of unauthorized digital copying and requires a higher level of security than is provided by trusted systems on available workstations. Instead, the publisher wants the book to be sent directly from an on-line bookstore to a trusted printer. Printing must be prepaid via digital tickets (see fee specification 601 ). To enable digital distribution to authorized distributors but not directly to consumers, the publisher requires that both parties in a Copy and Transfer right to have an authorizing digital license (see certificate specifications 602 and 603 ). Lacking such a license, a consumer can not access the work at a workstation. Instead, he or she must print the work. [0066] Also illustrated in FIG. 6 is the watermark specifications 604 . The watermark specification 604 is described in greater detail below with respect to FIG. 9 . Watermarks and Fingerprints [0067] Three main requirements for watermarks on trusted printers have been identified: [0068] Social Reminder. This requirement is for a visible printed indication about whether photocopying is permitted. This could be a printed statement on the document or an established icon or symbol within a corporation indicating a security level for the document. [0069] Auditing. This requirement is for a way to record information on the document about the printing event, such as who owns the print rights, whether photocopying is permitted, and what person or printer printed the document and when the document was printed. [0070] Copy Detection. This requirement is a way for differentiating between printed originals and photocopies. In general, this requirement involves using some print patterns on the page which tend to be distorted by photocopiers and scanners. For some patterns, the difference between copies and printed original is detectable by people; for other patterns, the difference is automatically detectable by a computer with a scanner. [0071] In the currently preferred embodiment, watermarks are created with embedded data technology such as glyph technology developed by the Xerox corporation. Glyph technology as it is used as embedded data printed on a medium is described in U.S. Pat. No. 5,486,686 entitled “Hardcopy Lossless Data Storage and Communications For Electronic Document Processing Systems”, which is incorporated by reference herein. Using glyphs as digital watermarks on printed documents is described in co/pending application Ser. No. 08/734,570 entitled “Quasi-Reprographics With Variable Embedded Data With Applications To Copyright Management, Distribution Control, etc.”, which is assigned to the same assignee as the present application and is incorporated by reference herein. [0072] Generally, embedded data technology is used to place machine readable data on a printed medium. The machine readable data typically is in a coded form that is difficult if not impossible for a human to read. Another example of an embedded data technology is bar codes. [0073] Embedded data technology can be used to carry hundreds of bits of embedded data per square inch in various grey patterns on a page. Preferably, glyphs are used because the marks representing the encoded data can be used to create marks which are more aesthetically appealing then other embedded data technologies. With careful design, glyphs can be integrated as graphical elements in a page layout. Glyphs can be used with any kind of document. Glyph watermarks to carry document identification can be embedded by the publisher; while glyphs carrying data about a print event can be added to the watermark at the time of printing by a printing system. Both document identification and fingerprinting data can be embedded in the same watermark. [0074] It should be noted that a disadvantage of glyphs and with all forms of visible and separable watermarks, is that with mechanical or computational effort, they can be removed from a document. [0075] FIG. 7 illustrates an example of a document image having a glyph encoded watermark. Referring to FIG. 7 , a document page 701 has various text 702 . Also included is a glyph encoded watermark 703 . Note that the document is not limited to text and may also include image or graphical data. [0000] Integrating Embedded Data as Watermarks into Trusted Printing Systems [0076] This section describes briefly how embedded data technology can be used in trusted printing systems to embed watermarking data. How glyphs and watermark data are handled at each stage in creating, publishing, and printing a document is discussed. [0077] It has been determined that for integrating embedded data such as glyphs into trusted printing systems, the requirements include: Document designers such as authors and publishers must be able to specify on a page by page basis the position and shape of watermarks, so that they can be incorporated into the design of the document. The approach should be compatible with mainline document creation (e.g. word processing) systems. The approach should work within the protocols of existing printers. The approach should carry the fingerprint (or run-time) data in Usage Rights specifications. The approach should not significantly slow down printing. [0083] Herein the term media-dependent data is used to refer to information about how a watermark is located and shaped within the document content. The approach depends on the use of Usage Rights to express the data to be encoded in the watermark. Document Creation [0084] Publishers use a wide variety of tools to create documents. Different text editors or word processors provide different ways and degrees of control in laying out text, pictures and figures. One thing that all text editors have is a way to locate text on a page. In effect, this is a lowest common denominator in abilities for all systems. [0085] Exploiting this common capability provides insight about how to use glyphs to represent watermarks: Glyph watermarks are organized graphically as rectangular boxes. Different sized boxes have different capacities for carrying data. On 300 dpi printers, about 300 bytes per inch can be encoded in glyphs. Note that this can represent even more data if the original data is compressed prior to glyph encoding. Note for greater reliability, some data may be repeated redundantly, trading data capacity for reliability. Each glyph watermark is represented to a document creation program as a character in an initial glyph watermark font. Boxes of different sizes and shapes are represented as different characters for the initial glyph watermark font. When a digital work is printed, the encoding of the data is analogous to calculating and changing the watermark font. [0089] In practice, a designer laying out a document would open a page of a glyph catalog containing glyph boxes of different sizes. The glyph boxes in the catalog would probably contain just test data, e.g. a glyph ASCII encoding of the words “test pattern glyph Copyright © Xerox Corporation 1997. All Rights Reserved”. The designer would determine ahead of time how much data he wants to encode per page, such as 100, 300, 500, or 1000 bytes. The designer would copy a “box” (actually a character) of the corresponding size into their document and locate it where they want it on the page, typically incorporating it as a design element. [0090] FIG. 8 illustrates a set of sample watermark characters (i.e. glyph boxes) having different storage capacities. An actual catalog would contain additional shapes and would be annotated according to the data-carrying capacity of the glyphs. [0091] Note that the glyph encoded watermarks can also be placed in figures, since drawing programs also have the capability to locate characters on a page. [0092] When the creator saves their work, the document creation program writes a file in which characters in the glyph font are used to represent the watermarks. If the creator prints the document at this stage, he will see more or less what the final sold versions will look like except that the test data encoded in the gray tones of the glyph box will later be replaced by the dynamically generated watermark data. Specifying Watermark Data [0093] When the author or publisher gets ready to publish the work and import it into a system for controlling distribution use of digital works, one of the steps is to assign rights to the work using a Rights Editor. The Rights Editor is a program with which a document owner specifies terms and conditions of using a digital work. [0094] This is the point at which document identification data and also print event data are specified. FIG. 9 illustrates the watermark information specified for a print right. Note that the watermark information specification is optional within the grammar. Referring to FIG. 9 , print right 901 specifies that a purchaser of the document must pay ten dollars to print the document (at fee specification 902 ). The document must only be printed on a trusted printer of a given type (at printer specification 903 ). Furthermore, the watermark must embed a particular string “Title: Moby Dog Copyright 1994 by Zeke Jones. All Rights Reserved” and also include various data about the printing event (at Watermark-Tokens specification 904 ). Note that the watermark tokens specification are used to specify the “fingerprint” information associated with the printing of the digital work. Here the specified printing event data is who printed it out, the name of the institution printing it out, the name of the printer, the location of the printer and the time that the digital work was printed. As will be described below, this information is obtained at print time. [0095] FIG. 10 is a flowchart summarizing the basic steps for a creator to cause watermarks to be placed in their documents. As part of the layout of the textual document the designer determines how much data is required by the watermark, step 1001 . Based on the amount of needed data, a suitable watermark character (e.g. glyph box) is selected, step 1002 . The watermark character is then positioned onto a page (or the pages) of the digital work, step 1003 . Finally, as part of the rights assignment for the digital work document, a print right with a watermark specification is made, step 1004 . At this point, the document can be viewed with the watermark positioned in the desired place(s) on the document. However, the actual fingerprint and other identifying data in an embedded data format has not yet been created. This is created dynamically at print time as described below. Printing the Digital Work [0096] The next steps for the digital work are that it is published and distributed. During this process, the digital work is protected by the encryption and other security systems that are employed and the rights travel with the document. Part of this process assures that any printer or workstation that has a copy of the document also has digital certificates which contain information identifying the trusted system, trusted printer, user, and so on (a process described in more detail in co-pending application Ser. No. 08/344,042). [0097] FIG. 11 is a flowchart of the steps required for printing a document. Referring to FIG. 11 , at some point, a user decides to print a document, step 1101 . Typically this is done via a print command invoked through some interface on the users system. This opens a challenge-response protocol between the “user” repository containing the document and the printer repository, step 1102 . During this exchange, the security and watermark capabilities of the printer are checked. If the printer does not have the proper security or watermark capabilities, the digital work cannot be printed on that printer. The printer security level and watermark capabilities are specified in the identification certificate for the printer. Assuming that the printer has the proper security levels and watermark capabilities, the “user” repository then checks that the digital work has the required print right, step 1103 . Assuming that the digital work has required print right the user repository may interface with a credit server to report any required fees for the printing the digital work, step 1104 . Note that the actual billing for the digital work may occur when the right is invoked either when the print exercised or when it can be verified that the document has been printed. The latter case protects the user in the situation wherein printing may become inadvertently terminated before the entire digital work is printed. [0098] A computation is then performed to gather together the information to be embedded in the watermark and to incorporate it into a new font for the watermark character. First the information must be gathered from digital identification certificates belonging to the user or the trusted printer, such as names, locations, and the current date and time, step 1105 . This information is “printed” internally into computer memory, creating a bitmap image of glyph boxes of different sizes, step 1106 . Creation and coding of glyphs is described in the aforementioned U.S. Pat. No. 5,486,686, thus no further discussion on the encoding of glyph patterns is deemed necessary. In any event, this information is then assembled into a font definition, step 1107 . [0099] The digital work is then decrypted and downloaded into the printer, step 1108 . When the digital work is downloaded into the printer, part of the protocol is also to download the new “revised” glyph font, which now has characters corresponding to glyph boxes. This font looks more or less like the one that the publisher used in creating the document, except that the gray codes inside the font boxes now embed the data that the publisher wants to appear in the watermarks on the document. [0100] The printer then prints the digital work, step 1109 . When the document is printed, the glyphs that appear on the pages contain the desired watermark data. Reading the Embedded Data Contained in the Watermark [0101] FIG. 12 is a flowchart outlining the basic steps for extracting the embedded data. First, the printed document is scanned and a digital representation obtained, step 1201 . The location of the watermark and the corresponding embedded data is then found, step 1202 . The watermark may be found using techniques for finding characteristic pixel patterns in the digital representation of the printed document. Alternatively, a template for the document may have been created that could be used to quickly find the watermark location. In any event, the embedded data is extracted from the watermark and decoded, step 1203 . The decoded data is then converted to a human readable form, step 1204 . This may be on a display or printed out. The data extracted is then used to identify who and where the unauthorized reproduction of the digital work came from. [0102] Note that the means for extraction of the watermark data is dependent on the technology used to embed the watermark data. So while the actual extraction steps may vary, they do not cause departure from the spirit and scope of the present invention. Trusted Printer Embodiments [0103] In the following, two embodiments of trusted printer implementations are described: desktop implementations for personal printers and print server implementations for larger workgroup and departmental printers. Desktop Implementations [0104] There is a large and growing install base of personal printers. Typically, such printers are connected to personal computers by serial output ports. In other cases, they are installed on small local area networks serving a few offices. [0105] To serve this market a “trust box” is provided which would be positioned in between the personal computer and the personal printer. The “trust box” would act as a print repository for the trusted printer system. This is a market where the purchase of such hardware would be justified by the convenience of digital delivery to the office, for those documents that publishers are unwilling to send in the clear (i.e. not encrypted). The cost of the trust box offsets either waiting for mail delivery or driving to another location to pick up trusted printer output. [0106] FIG. 13 is an illustration of a trust box in a computer based system. Referring to FIG. 13 , a personal computer 1301 is coupled to a network 1302 . The personal computer 1301 itself is part of a trusted system in that it embodies a repository. The personal computer would receive digital works through the network 1302 (e.g. over the Internet). The personal computer 1301 is further coupled to trust box 1303 . The communications between the repository contained in the personal computer 1301 and the trust box 1303 are encrypted for security purposes. Finally, the trust box 1303 is coupled to a printer 1304 . The printer 1304 receives decrypted print streams for printing. [0107] From a conceptual perspective, the personal computer combined with the trust box and printer form a trusted system. The trust box implementation would work with other system elements as illustrated in the steps of the flowchart of FIG. 14 . [0108] Referring to FIG. 14 , the consumer contacts the distributor of digital works using, for example, an Internet browser such as Netscape Navigator or Microsoft Explorer, step 1401 . For the sake of brevity, it is assumed that a trusted session is established between the consumer's repository and the distributor's repository. Using known user interface methods, the consumer selects a work from a catalog or search service, step 1402 . In this example, it is assumed that the rights holder has associated a Print right with the document, and that all terms and conditions for exercising the right are met by the consumer and the trust box. [0109] Once a work is selected the two repositories begin a purchase transaction, step 1403 . As described in application Ser. No. 08/344,042, there are several variations for billing. For concreteness, it is assumed that there is a billing account associated with the trust box. [0110] Using a helper application (or equivalent), the consumers repository sends a digital certificate to the distributor which contains the trust box's public key, step 1404 . The certificate itself is signed by a well-known repository, such as the printer's manufacturer. [0111] The distributor repository encrypts the document using DES or some other encryption code, step 1405 . The encryption uses a key length that is compatible with requirements of security and legal constraints. The distributor repository encrypts the document key in an envelope signed by the public key of the printer box, step 1406 . The distributor repository then sends the encrypted document and the envelope along to the consumer's workstation. [0112] The personal computer stores the encrypted document in its repository along with the envelope containing the key, step 1407 . [0113] At some point, the user decides to print the document. Using a print program, he issues a print request, step 1408 . His personal computer contacts the trust box, retrieving its identity certificate encrypted in its public key, step 1409 . It looks up the watermark information in certificates from the user, the computer itself, and the printer, step 1410 . It downloads the watermark font to the printer through the trust box, step 1411 . [0114] The print program begins sending the document, one page at a time to the trust box, step 1412 . [0115] The trust box contacts the printer. It decrypts the document giving the document key to a decryption means (e.g. an internal decryption chip), step 1413 . It transmits the document to the printer in the clear, step 1414 . Note that this is one place where a digital copy could be leaked, if a printer emulator was plugged into the print box to act like a printer. Presumably the security level of the trust box is set to a value that reflects the level of risk. The document is then printed, step 1415 . [0116] The trusted print box design is intended to meet several main design objectives as follows: [0117] Installed Base. This approach is intended to work within the current installed base of desktop or personal printers. Installing a trusted print box requires loading software and plugging standard serial cables between the printer, the trusted print box, and the computer. [0118] Security. The approach inhibits unauthorized photocopying through the use of glyph watermarks. The approach inhibits digital copying by storing digital works in an encrypted form, where the consumer workstation does not have access to the key for decrypting the work. [0119] Printer Limitations. The approach assumes that the user will plug the trusted print box into a standard printer. The printer is assumed to not have the capability of storing extra copies of the digital work. [0120] Building box in Printer. Variations of this approach include incorporating the trusted print box into the printer itself. That variation has the advantage that it does not present the document in the clear along any external connectors. [0121] Weak Link. A weak link in this approach is that there is an external connector that transmits the document in the clear. Although this is beyond the average consumer, it would be possible to build a device that sits between the trusted printer box and the printer that would intercept the work in the clear. [0122] Billing Variations. In the version presented here, the trusted print box has secure storage and programs for managing billing records. A simpler version of the approach would be to keep track of all billing on-line. For example, one way to do this would be to have the document printing start at the time that the customer orders it. In this variation, the document is still sent in encrypted form from the publisher, through the consumers workstation, decrypted, and sent to the trusted print box, to the printer. The difference is that the trusted print box no longer needs to keep billing records and that the consumer must start printing the document at the time that the document is ordered. [0123] Software-only Variation. Another variation on the desktop printing solution involves only software. The consumer/client purchases the work and orders the right to print it once. The on-line distributor delivers the work, encrypted, one page at a time. The consumer workstation has a program that decrypts the page and sends it to the printer with watermarks, and then requests the next page. At no time is a full decrypted copy available on the consumer's computer. The weak link in this approach is that the consumer's computer does gain access to copies of pages of the work in the clear. Although this would be beyond the average consumer, it would be possible to construct software either to mimic runtime decryption software or modify it to save a copy of the work, one page at a time. Printer Server Implementations [0124] Much of the appeal of trusted printers is to enable the safe and commercial printing of long documents. Such printing applications tend to require the speed and special features of large, shared printers rather than personal printers. Provided herein is an architecture for server-based trusted printers. [0125] Besides the speed and feature differences of the print engines themselves, there are some key differences between server-based trusted printers and desktop trusted printers. Server-based printers store complete copies of documents in files. Server-based printers have operating systems and file systems that may be accessible via a network. Server-based printers have consoles, accessible to dedicated or walk-up operators depending on the installation. [0129] These basic properties of server-based printers create their own risks for document security which need to be addressed. In addition, since server-based printers tend to be high volume and expensive, it is important that the trusted system features not significantly slow down competitive printer performance. [0130] From a conceptual perspective, the print server (including network services and spooling) combined with the printer forms a trusted system. [0131] In abstract and functional terms, the operation of the server implementation is similar to that of the trust box implementation. The difference is that the server performs many of the operations of the trust box. [0132] There are many variations on how the print server may need to interoperate with the other system elements. For example, the transaction with the printer may be with the user's computer or with an on-line repository that the user is communicating with. In the following, the transaction is described as happening from a repository, although that repository may be the user's own computer. [0133] FIG. 15 is a block diagram illustrating a print server implementation. Referring to FIG. 15 , a consumer workstation 1501 is coupled to publisher repository 1502 . The publisher repository 1502 couples directly with a spooler in printer repository 1503 . The spooler is responsible for scheduling and printing of digital works. The spooler 1503 is coupled to the printer 1504 . [0134] The server implementation would work with other system elements as illustrated in the steps of the flowchart of FIG. 16 . Referring to FIG. 16 , the repository contacts the trusted printer's server, engaging in a challenge-response protocol to verify that the printer is of the right type and security level to print the work, step 1601 . These interactions also give the printer public certificates for the repository and user, that are used for retrieving watermark information. [0135] The distributor encrypts the document using DES or some other code, using a key length that is compatible with requirements of security and legal constraints, step 1602 . It encrypts the document key in an envelope signed by the public key of server, step 1603 . It sends the encrypted document to the server, step 1604 . [0136] Note that in some versions of this architecture, different levels of encryption and scrambling (less secure) are used on the document at different stages in the server. It is generally important to protect the document in all places where it might be accessed by outside parties. The use of lower security encoding is sometimes used to avoid potentially-expensive decryption steps at critical stages that would slow the operation of the printer. [0137] In any event, the server stores the encrypted document, step 1605 . At some point, the spooler gets ready to print the document. Before starting, it runs a process to create a new version of the glyph font that encodes the watermark data, step 1606 . It looks up the required watermark information in its own certificates as well as certificates from the repository and user. [0138] Finally, the spooler begins imaging the document, one page at a time, step 1607 . [0139] Thus, trusted rendering systems for use in a system for controlling the distribution and use of digital works are disclosed. While the present invention is described with respect to a preferred embodiment, it would be apparent to one skilled in the art to practice the present invention with other configurations of information retrieval systems. Such alternate embodiments would not cause departure from the spirit and scope of the present invention. [0000] APPENDIX A GRAMMAR FOR THE USAGE RIGHTS LANGUAGE work-specification ->   (Work:   (Rights-Language-Version: version-id)   (Work-ID: work-id ) opt   (Description: text-description ) opt   (Owner: certificate-spec ) opt   (Parts: parts-list ) opt   (Contents: (From: address ) (To: address )) opt   (Copies: copy-count ) opt   (Comment: comment-str ) opt   rights-group-list ) parts-list -> work-id | work-id parts-list copy-count -> integer-constant | unlimited rights-group-list ->   rights-group-spec rights-group-list opt rights-group-spec ->   ( rights-group-header rights-group-name   bundle-spec opt   comment opt   rights-list ) rights-group-header ->   Rights-Group: |   Reference-Rights-Group: bundle-spec->   (Bundle: comment opt time-spec opt access-spec opt     fee-spec opt watermark-spec opt ) comment -> (Comment: comment-str) rights-list -> right rights-list opt right -> (right-code comment opt time-spec opt access-spec opt fee-spec opt ) right-code ->   transport-code |   render-code |   derivative-work-code |   file-management-code |   configuration-code transport-code -> transport-op-spec next-copy-rights-spec opt : transport-op-spec ->   Copy: |   Transfer: |   Loan: remaining-rights-spec opt next-copy-rights-spec -> ( Next-Copy-Rights: next-set-of-rights ) remaining-rights-spec -> ( Remaining-Rights: rights-groups-list ) next-set-of-rights -> rights-to-add-spec opt | rights-to-delete-spec opt rights-to-add-spec -> ( Add: rights-groups-list ) rights-to-delete-spec -> ( Delete: rights-groups-list ) render-code ->   Play: player-spec opt |   Print: printer-spec opt |   Export: repository-spec opt player-spec -> (Player: certificate-list ) opt (Watermark: watermark-spec) opt printer-spec -> (Printer: certificate-list ) opt (Watermark: watermark-spec) opt repository-spec -> (Repository: certificate-list ) opt derivative-work-code ->   derivative-op-spec editor-spec opt next-copy-rights-spec opt derivative-op-spec ->   Edit: |   Extract: |   Embed: editor-spec -> (Editor: certificate-list ) file-management-code ->   Backup: backup-copy-rights-spec opt |   Restore: |   Verify: verifier-spec opt |   Folder: |   Directory: |   Delete: backup-copy-rights-spec -> Backup-Copy-Rights: rights-groups-list verifier-spec -> (Verifier: certificate-list) configuration-code ->   Install: |   Uninstall: time-spec ->   (Time: interval-type expiration-spec opt ) interval-type ->   fixed-interval-spec |   sliding-interval-spec |   metered-interval-spec fixed-interval-spec -> (From: moment-spec ) sliding-interval-spec -> (Interval: interval-spec ) metered-interval-spec -> (Metered: interval-spec ) expiration-spec -> (Until: moment-spec ) moment-spec -> date-constant time-of-day-constant opt interval-spec ->   calendar-units-constant |   time-units-constant |   calendar-units-constant time-units-constant fee-spec -> (Fee: ticket-spec | monetary-spec ) ticket-spec -> (Ticket: (Authority: authority-id) (Type: ticket-id )) monetary-spec ->   ( fee-type min-price-spec opt max-price-spec opt account-spec ) fee-type ->   (Per-Use: money-units )|   (Metered: (Rate: money-units )     ( Per: interval-spec ) (By: interval-spec) opt |   (Best-Price-Under: money-units )|   (Call-For-Price: dealer-id ) |   (Markup: percentage ) money-units -> floating-constant (Currency: ISO-Currency-Code ) opt account-spec -> (To: account-id ) (House: clearing-house-id) opt | (From: account-id ) (House: clearing-house-id) opt min-price-spec -> (Min: (Rate: money-units ) (Per: interval-spec )) max-price-spec -> (Max: (Rate: money-units ) (Per: interval-spec )) access-spec ->   (Access: security-class-spec opt   user -spec opt   source-spec opt   destination-spec opt )  -class-spec -> (Security: s-list ) s-list -> s-pair | s-pair s-list s-pair -> (s-name: s-value ) s-name -> literal-constant s-value -> floating-constant user-spec -> (User: authorization-spec) source-spec -> (Source: authorization-spec) destination-spec ->   (Destination: authorization-spec) authorization-spec ->   (Any: certificate-list ) |   certificate-list certificate-list -> certificate-spec certificate-list opt certificate-spec -> (Certificate: (Authority: authority-id) property-list opt ) property-list-> property-pair | property-pair property-list property-pair -> (property-name: property-value) property-name -> literal-constant property-value -> string-constant | literal-constant     | floating-constant | integer-constant watermark-spec -> watermark-info-list watermark-info-list -> watermark-str-spec opt watermark-info-list opt | watermark-token-spec opt watermark-info-list opt | watermark-object-spec opt watermark-info-list opt watermark-str-spec -> (Watermark-Str: watermark-str) watermark-token-spec -> (Watermark-Tokens: watermark-tokens ) watermark-tokens -> watermark-token watermark-tokens opt watermark-token -> all-rights | render-rights |         user-name | user-id | user-location |         institution-name | institution-id | institution-location |         render-name | render-id | render-location | render-time watermark-object-spec -> (Watermark-Object: work-id )

A trusted rendering system for use in a system for controlling the distribution and use of digital works. A trusted rendering system facilitates the protection of rendered digital works which have been rendered on a system which controls the distribution and use of digital works through the use of dynamically generated watermark information that is embedded in the rendered output. The watermark data typically provides information relating to the owner of the digital work, the rights associated with the rendered copy of the digital work and when and where the digital work was rendered. This information will typically aid in deterring or preventing unauthorized copying of the rendered work to be made. The system for controlling distribution and use of digital works provides for attaching persistent usage rights to a digital work. Digital works are transferred between repositories which are used to request and grant access to digital works. Such repositories are also coupled to credit servers which provide for payment of any fees incurred as a result of accessing a digital work.

[0001] This application claims priority from U.S. Provisional Application Serial No. 60/276,090 filed Mar. 16, 2001 and U.S. Provisional Application Serial No. 60/314,101 filed Aug. 23, 2001. The entirety of those provisional applications is incorporated herein by reference. BACKGROUND OF THE INVENTION FIELD OF THE INVENTION [0002] The present invention relates to a fluorescent biosensor that functions by a novel Quencher-Tether-Ligand (QTL) mechanism. In particular, the present invention relates to improving the polymer-QTL approach by co-locating the fluorescent polymer (or polymer ensemble, including self-assembled polymers) and a receptor for the QTL bioconjugate and target analyte on the same solid support. DISCUSSION OF THE BACKGROUND [0003] The polymer-QTL (Quencher-Tether-Ligand) approach is a single-step, instantaneous, homogeneous assay where the amplification step is intrinsic to the fluorescent polymer. The polymer-QTL approach provides a system for effective sensing of biological agents by observing fluorescence changes. The key scientific basis is the amplification of quenching of fluorescence that can be obtained with certain charged conjugated polymers and small molecule quenchers. In addition, the process is uniquely simple because there are no reagents. [0004] In the “biosensor 38 mode, the QTL approach functions by having a fluorescent polymer quenched by a specially constructed “quencher-tether-ligand” (QTL) unit as shown in the diagram set forth in FIG. 1. Addition of an analyte containing a biological receptor specific to the ligand is expected to remove the QTL conjugate from the polymer which results in a “turning on” of the polymer fluorescence. A fluorescent polyelectrolyte-based superquenching assay has been shown to offer several advantages over conventional small molecule based fluorescence assays. For example, conjugated polyelectrolytes, dye-pendant polyelectrolytes, etc. can “harvest” light effectively both by absorption and by superquenching (1-5). The enhanced absorbing power of the polymers is indicated by the observation that even sub nanomolar solutions of some of these materials are visibly colored. The fluorescence of these polymers can be detected at even lower concentrations. Superquenching occurs in the presence of small molecules capable of serving as electron transfer or energy transfer quenchers to the polymer or one of its repeat units. [0005] The “Stern-Volmer” quenching constants (K SV ) for these polymers have been shown to be as high as 10 8 -10 9 M −1 , and it is anticipated that values as high as 10 11 M −1 may be attainable (6). Such high values for K SV toward quenchers oppositely charged to the polyelectrolyte are initiated by strong nonspecific binding between the quencher and the polyelectrolyte. Subsequent amplified quenching occurs due to a combination of excitonic delocalization and energy migration to the “trapsite 38 where the quencher is in close proximity with the polymer. [0006] It has also been shown that enhanced superquenching may be obtained when the polymers are adsorbed onto charged supports including surfaces, polymer microspheres, and inorganic nanoparticles (7,8). Superquenching has also been observed in the same supported formats for monomers or small oligomers self-assembled into “virtual” polymers. Polymer (and “virtual” polymer) superquenching has been adapted to biosensing by constructing QTL conjugates containing a potential superquenching component (Q) tethered (T) to a bioreceptor (L) or ligand for a specific biomolecule (1). [0007] A fluorescence based assay is realized when the QTL conjugate is used to qench the polymer either in solution or in supported formats at solution-solid or solution-particle interfaces (1,7,8). For example, fluorescent polyelectrolytes, including conjugated and J-aggregate polymers, can be used for sensitive biodetection and bioassays in solution formats. The basis of this detection is the combination of the “superquenching” sensitivity of these molecules to quenchers of opposite or 15 neutral charges with the synthesis of a quencher-recognition conjugate (e.g., a QTL molecule). In the original formulation, the QTL conjugate quenches the polymer ensemble by nonspecific binding. Addition of a target bioagent capable of binding with the L component of the QTL conjugate results in a removal of the QTL conjugate from the polymer and a turning on of the polymer fluorescence. [0008] A fluorescence turn off (or modulation) assay has also been developed based on polymer superquenching (5). In this case, the target molecule is a bioagent L, or L′, corresponding to the L component of the QTL conjugate, and the receptor is a biomolecule that strongly associates with L, I,′ or the QTL conjugate. One example is a direct competition assay in which L (or L′) in unknown amount is allowed to compete with the QTL conjugate for the binding sites of a measured amount of the receptor. The polymer fluorescence is quenched by non-bound QTL to an extent depending on the amount of L (or L′) present. In another example, the QTL conjugate is preassociated with the receptor; when all of the QTL conjugates are associated with the receptor sites, no quenching is observed. Addition of L (or L′) to the sample results in the release of the QTL conjugate with concomitant quenching of the polymer fluorescence. [0009] All of the above assay formats depend on nonspecific quenching of the polymer fluorescence by association of the QTL conjugate with the polymer. A complication with these assays is the competing nonspecific interactions of other components of the assay sample with either the polymer, the QTL conjugate, or both, which result in a modulation of the quenching. In the present invention, modifications of the polymer superquenching allow the construction of improved assays which overcome these effects and provide for a more versatile and robust sensor. SUMMARY OF THE INVENTION [0010] It is an object of the invention to provide a novel chemical moiety formed of a quencher (Q), a tether (T), and a ligand (L) specific for a particular bioagent. [0011] It is another object of the invention to provide an assay to detect a target agent in a sample using the novel QTL molecule of the present invention and a fluorescent polymer. [0012] It is yet another object of the invention to rapidly and accurately detect target biological agents in a sample. [0013] It is a feature of the invention that the fluorescent polymer and the receptor for the target biological agent are co-located on a support. [0014] It is another feature of the invention that the co-located fluorescent polymer and the receptor are tethered to the support. [0015] It is yet another feature of the invention that the co-located fluorescent polymer and receptor are covalently linked to the support. [0016] It is also a feature of the present invention to covalently link the receptor to the fluorescent polymer. [0017] It is a further feature that the change in fluorescence is indicative of the presence of the target biological agent. [0018] It is another feature of the invention that the quench event is a result of a specific interaction between the receptor and the QTL conjugate. [0019] It is yet another feature of the present invention that the assembled monomers behave like polymers. [0020] It is an advantage of the invention that the assays of the present invention can be carried out in operationally different formats. [0021] A further advantage of the invention is the versatility provided by the ability to control the co-located assembly of a specific polymer ensemble-receptor either spatially as on a rigid support or on different particles. [0022] It is another advantage of the present invention that assays according to the present invention are both homogeneous and near instantaneous. [0023] It is yet another advantage of the invention that the ability to control the co-located polymer assembly either spatially (e.g., on a rigid support) or on different particles offers great versatility. [0024] It is a further advantage that superquenching occurs due to specific ligand-receptor interactions. BRIEF DESCRIPTION OF THE DRAWINGS [0025] [0025]FIG. 1 is a general illustration of the QTL approach. [0026] [0026]FIG. 2 illustrates various fluorescent compounds, quenchers, and QTL conjugates used in the present invention. [0027] [0027]FIG. 3 illustrates various fluorescent compounds, quenchers, and QTL conjugates used in the present invention. [0028] [0028]FIG. 4 illustrates structures of dyes used with polysaccharides in inclusion complexes. [0029] [0029]FIG. 5 is a general illustration of a displacement competition assay. [0030] [0030]FIG. 6 is a general illustration of a direct competition assay. [0031] [0031]FIG. 7 is an illustration of the competitive fluorescence “turn-on” assay with the polymer-biomolecule combination. [0032] [0032]FIG. 8 illustrates the co-location of a polymer and a receptor by a covalent/adsorption sequence. [0033] [0033]FIG. 9 illustrates the covalent tethering of both the polymer and the receptor binding site. [0034] [0034]FIG. 10 illustrates a receptor covalently linked to a polymer. [0035] [0035]FIG. 11 is an illustration of a sandwich QTL assay. [0036] [0036]FIG. 12 illustrates various compounds used in the examples of the present invention. [0037] [0037]FIG. 13 is a graphical illustration of the quenching of fluorescence as a function of the loading level. [0038] [0038]FIG. 14 is a graphical illustration of a competition assay for goat anti-rabbit IgG antibody. [0039] [0039]FIG. 15 is a graphical illustration of an IgG assay with polymer 25 linked covalently to a receptor. [0040] [0040]FIG. 16 illustrates the synthesis of cyanine dye 26 covalently appended to a silica microsphere surface. [0041] [0041]FIG. 17 is an illustration of the structure of QSY-21 Succinimidyl Ester. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0042] A key scientific basis for the polymer QTL approach is the amplification of quenching of fluorescence (superquenching) that may be obtained with certain polymers (including, but not limited to, charged polymers, conjugated polymers and dye-pendant polyelectrolytes in which the chromophores are collected by non-covalent interactions (e.g., J-aggregation)) and small molecule quenchers. The fluorescent polymers provide amplification over conventional molecular fluorophores both by virtue of their light-harvesting properties (collective excitation) and their sensitivity to superquenching (i.e., one quencher may extinguish luminescence from an entire polymer chain or a collection of polymers, oligomers, or monomers). In some cases, enhanced quenching may be observed when mixtures of polymers are used or when the polymers are adsorbed or otherwise assembled onto surfaces. The same enhancement of quenching can be observed when monomers or oligomers of some of the chromophore repeat units are assembled either by covalent attachment or adsorption onto a support. The support may be, but is not limited to, any of the following: polymer or silica microspheres, organic or inorganic nanoparticles, magnetic beads or particles, semiconductor nanocrystals, tagged or luminescent particles, membranes and planar or corrugated solid surfaces. [0043] Fluorescent polymer superquenching has been adapted to biosensing applications through the use of “QTL” bioconjugates (1, 4-6, 8). The QTL approach to biosensing takes advantage of the superquenching of fluorescent polyelectrolytes by electron transfer and energy transfer quenchers. In its simplest approaches, the fluorescent polymer, P, forms an association complex with a QTL bioconjugate, usually one with the opposite charge of P. QTL bioconjugates include a small molecule electron transfer or energy transfer quencher (Q), linked through a covalent tether to a ligand, L, that is specific for a particular bioagent or receptor. The binding of the QTL bioconjugate by the bioagent either removes the QTL bioconjugate from the fluorescent polymer, or modifies its quenching efficiency, thus allowing sensing of the bioagent in a readily detectable way. [0044] Suitable examples of ligands that can be used in “QTL” methods include chemical ligands, hormones, antibodies, antibody fragments, oligonucleotides, antigens, polypeptides, glycolipids, proteins, protein fragments, enzymes, peptide nucleic acids (PNAs), and polysaccharides. Examples of suitable tethers include, without limitation, single bonds, single divalent atoms, divalent chemical moieties of up to approximately 100 carbon atoms in length, multivalent chemical moieties, polyethylene, polyethylene oxides, polyamides, non-polymeric organic structures of at least about 7-20 carbon atoms, and related materials. Suitable quenchers include methyl viologen, quinones, metal complexes, fluorescent and nonfluorescent dyes, and energy accepting, electron accepting, and electron donating moieties. These examples of the ligand, tethering elements, and quenchers are not to be construed as limiting, as other suitable examples would be easily determined by one of skill in the art. Polymer-Polymer Ensembles and Their Application to Biosensing [0045] The fluorescent polyelectrolytes typified by compounds 1 and 2 in FIG. 2 show, in addition to their adsorption properties, a very strong tendency to associate with oppositely charged macromolecules, including other polyelectrolytes and each other. Cationic conjugated polymer 8 , together with compounds 1 and 2, form a series of three fluorescent polyelectrolytes with absorption maximum wavelengths that span the range from the near ultraviolet to the visible-infrared, especially by varying the cyanine substituent in compound 2. [0046] The association of two oppositely charged fluorescent polyelectrolytes can lead to several interesting and potentially useful effects considering the association of compounds 1 and 2. For example, the association of nearly equimolar, in repeat units, amounts of compounds 1 and 2 results in an ensemble that is overall close to neutral, yet consists of discrete regions of negative and positive charges. Since compound 2 shows an emission at lower energies than compound 1, it is observed that energy transfer should occur. Thus, excitation into regions where the absorption should be primarily by compound 1 results in predominant emission by compound 2. Since compound 2 has a very sharp emission, the harvesting of energy within the ensemble provide possibilities to tune both the absorption and emission properties far beyond that which is available within a single polymer. A most striking advantage obtained by using an ensemble such as the combination of compounds 1 and 2 is that both anionic and cationic small molecule quenchers can quench the overall near-neutral polymer mixture. As a result, it is observed that the ensemble is quenchable (independently) by both anionic compound 4 and cationic compound 3. More importantly, the quenching can be observed at very low concentrations of either quencher such that the degree of superquenching shows only a slight attenuation compared to quenching of the individual polymers by the oppositely charged small molecule. [0047] These results show that the polymer-polymer approach offers distinct advantages for biosensing by the polymer-QTL method. The polymer ensemble can be quenched by both positive and negatively charged QTL bioconjugates. Therefore, either in quench/unquench formats or in a competitive assay, the polymer-polymer ensemble provides a means of obtaining higher selectivity and specificity. Furthermore, the degree of quenching by either cationic or anionic quenchers can be tuned directly by varying the stoichiometry of the polymer mixture. For example, when polymer 1 and polymer 2 are mixed in a ratio of 100:1, the superquenching by cationic QTLs is maintained and no quenching by anionic QTLs is observed. However, efficient energy transfer is still observed to polymer 2 even at this low ratio. By going to a 2:1 ratio of polymer 1: polymer 2, superquenching by both cationic and anionic QTLs is observed. Thus, charge tuning of the QTL assay is achieved by altering the stoichiometry of the anionic and cationic polymer. Both the net charge of the supramolecular cluster and the energy transfer characteristics of the combination may be tuned in this manner. Multiplexed Detection Using Mixtures Containing Supported Polymer [0048] The interaction of anionic and cationic fluorescent polymers can be eliminated by first anchoring either polymer to a bead or other supported format. For example, it has been demonstrated that anchoring polymer 2 to a clay suspension, prior to the addition of polymer 1 prevents the association of polymers 1 and 2. In this way, independent superquenching of each polymer is achieved in a single solution upon addition of either cationic or anionic quenchers. Supported Formats for Monomers, Oligomers and Polyelectrolytes [0049] Fluorescent polyelectrolytes, including conjugated and J-aggregate polymers, can be used for sensitive biodetection and bioassays in solution formats. The basis of this detection is the combination of the “superquenching” sensitivity of these molecules to quenchers of opposite or neutral charges with the synthesis of a quencher-recognition conjugate (QTL). One improvement of the polymer-QTL approach involves anchoring the fluorescent polymer onto a solid support via adsorption. Several advantages can result from this adsorption. [0050] Fluorescent polyelectrolytes, including, but not limited to, compounds such as those shown in FIGS. 2 and 3 may be readily adsorbed from aqueous or mixed aqueous-organic solutions onto oppositely charged surfaces such as slides, plates, oppositely charged polymer beads (such as, but not limited to, quaternary amine-derivatized polystyrene or sulfonated polystyrene), and natural or synthetic inorganic supports such as clays or silica, charged membranes, or other porous materials. Once adsorbed onto these supports, the polymers retain their intense fluorescence as well as their sensitivity to specific quenchers. The fluorescent polymers incorporated into these formats may be used in advanced assays as described below. [0051] The incorporation of a fluorescent polymer onto a charged polymer bead can result in the reversal of the charge specificity in quenching of the polymer fluorescence as well as in improved performance in assays involving the polymer in either fluorescence quench or fluorescence unquench modes. In one example, the anionic conjugated polymer 1 is effectively quenched by low concentrations of the positively charged electron acceptor 3 in aqueous solution. However, its fluorescence is largely unaffected in solution by the addition of the negatively charged electron acceptor 4. When polymer 1 is treated with a suspension of quaternary amine (cationic) derivatized polystyrene beads (Source 30 Q), the polymer is removed from solution and is irreversibly adsorbed onto the beads. In this supported format, the highly fluorescent beads can be suspended in an aqueous solution and treated with the same quenchers. A reversal of the quenching sensitivity is observed; in the supported format, the anionic electron acceptor 4 quenches polymer 1, while the fluorescence of polymer 1 is no longer quenched by cationic electron acceptor 3. [0052] The charge reversal of fluorescence quenching can be adapted to biosensing by the polymer-QTL approach. Thus, QTL conjugate 5, which contains an anthraquinone quencher similar to anionic electron acceptor 4 and a biotin ligand, is also observed to quench the fluorescence of polymer 1. Upon addition of the protein avidin (a specific receptor for biotin), the quenching produced by conjugate 5 is reversed and virtually complete recovery of the fluorescence of polymer 1 is observed. This contrasts with aqueous solutions where a viologen-based conjugate 6 has been shown to elicit a similar quench-recovery response with polymer 1. For both polymers 1 and 2, when dissolved in aqueous or partially aqueous solutions, nonspecific effects are frequently observed upon the polymer fluorescence by addition of macromolecules, particularly proteins leading to either partial quenching or enhancement. These interactions may occur with analyte proteins or with proteins not anticipated to interact with the specific QTL conjugate employed in the sensing and may interfere with specific effects due to the interaction of an “analyte” protein with the polymer QTL complex. These nonspecific effects maybe eliminated or attenuated by employing polymers in supported formats. [0053] A second example involves the use of the QTL conjugate 7, which quenches the fluorescence of polymer 1 by energy transfer. While anionic compound 7 does not quench the fluorescence of anionic polymer 1 in pure aqueous solutions, adsorption of polymer 1 on beads results in its quenching upon the addition of compound 7 and fluorescence recovery upon addition of avidin. [0054] Adsorbing a fluorescent polymer on a charged support may not always lead to charge reversal in the quenching of the polymer. The charge reversal, or lack thereof, can be tuned by the degree of “loading” of the polymer onto sites on the support. In a different example, it is demonstrated that enhanced quenching can be obtained for a supported polymer as a consequence of adsorption. Thus, when cationic polymer 2 is adsorbed onto anionic Laponite clay particles, the polymer fluorescence is still subject to quenching when small amounts of anionic acceptor 4 are added to the aqueous suspension. Under these loading conditions, polymer 2 is not quenched by cationic acceptors such as compound 3. Quantitative analysis of the extent of quenching by compound 4 under these conditions indicates that the clay-supported polymer 2 is quenched more effectively (in this example by more than 30%) than when it is in a pure aqueous solution. This example illustrates two concepts that lead to improved biosensing with the polymer-QTL approach using supported polymers. The first concept is that the supported polymer can be used to “sense” oppositely charged quenchers when supported on the clay particles and yet exhibit improved stability with respect to degradation and precipitation (observed for aqueous solutions). When the same polymer is supported on the clay at lower loading levels, its fluorescence is quenched by cationic compound 3, thus demonstrating a charge reversal similar to that cited above with polymer 1. The second concept from these experiments with clay-supported polymer 2 and its quenching by compound 4 is that increased quenching sensitivity can be obtained due to polymer-polymer association effects on the clay particles. This increased quenching sensitivity may result from an increase in the J-aggregate domain (or conjugation length for conjugated polymers). [0055] The combination of enhanced quenching sensitivity and the ability to tune the quenching sensitivity in supported formats as described above greatly extends the potential of the polymer-QTL approach both in regards to sensitivity and versatility. Additionally, the anchoring of fluorescent polyelectrolytes on beads, surfaces, or membranes can expand the utility of the polymer-QTL approach. Thus, the strong adsorption of the polymers onto beads or membranes can provide detection of analytes in a “flow-through” mode using either liquid or vapor streams. Additionally, the tethering of the polymer onto plates in a multi-well array format by adsorption demonstrates the use of these formats in high throughput screening and rapid sampling applications. Furthermore, the elimination of nonspecific effects upon anchoring to a bead surface greatly enhances the practical usage of QTL-based assays. Virtual Polymers Based on Covalent Attachment of Supramolecular Building Blocks [0056] Enhanced superquenching provides a new means of obtaining superquenching from much smaller oligomers and even monomers in an adsorbed format. Thus, it is possible to synthesize polymer 2 in a range of repeat unit sizes varying from n=3 to n=1000. It would be anticipated that, to a first approximation, in solution, the higher molecular weight polymers should exhibit higher quenching efficiencies due to an “amplification factor” that should be directly proportional to the number of repeat units (6). However, as the number of repeat units increases, the solubility of the polymer decreases and the complexity of the polymer allows new channels for nonradiative decay to attenuate the effectiveness of quenchers. Therefore, in the case of polymer 2, the potential for attaining maximum sensitivity by using very high molecular weight polymers cannot be recognized. The use of smaller oligomers (or even monomers) in an adsorbed format permits the construction of effective higher order polymers by the formation of extended aggregates that bridge across adjacent polymer (or monomer or oligomer) molecules. This provides for enhanced levels of superquenching and thus new sensors of greatly enhanced sensitivity. [0057] Assembly of cyanine dye monomer 15 or oligomers 10 on silica or clay nanoparticles results in the formation of “J” aggregates that exhibit high superquenching sensitivity (i.e., surface activated superquenching) to ionic electron transfer or energy transfer quenchers. This can be attributed to a combination of high charge density (and resulting Coulombic interactions) and excitonic interactions within the self-assembled units. These assemblies also can be used as biosensors in the QTL fluorescence quench-unquench mode. These virtual polymers can be easily assembled from a variety of monomer or small building blocks, often bypassing difficult steps of polymer synthesis, purification, and characterization. Although studies to date have shown self-assembled virtual polymers to be relatively stable with little sensitivity in their fluorescence to added macromolecules, it is clear that the small adsorbed units may be subject to desorption or rearrangement under certain conditions, most notably high ionic strength. An approach that combines the simplicity of using small building blocks assembled on a surface with a more robust analysis platform involves the covalent tethering of monomers on the surface of a neutral or charged nanoparticle, bead, or other rigid support. [0058] In one example, a relatively simple synthetic scheme similar to that developed for the cyanine poly-L-lysine 10 was employed in the construction of cyanine dye 15 covalently attached to the surface of 0.2 μm diameter silica microspheres. The cyanine dye thus linked to the microsphere surface was found to exist both as small clusters of the monomer and as highly ordered aggregates. Efficient exiton migration/energy transfer between the dye clusters and aggregates was observed when the material was suspended in water containing 2% dimethylsulfoxide. The suspension also showed a 27% reduction in emission intensity in the presence of 27 nM anionic quencher 13, indicating that superquenching of the covalently-linked dye assemblies occurs. The modes of interaction between cyanine dye monomers on the microsphere may be controlled by varying the density and structure of functional groups present on the surface. Thus, the efficiency of biosensing can be optimized. Similar schemes may be used to append other cyanine dyes and other building blocks such as conjugated polymer oligomers onto a bead, particle, or other solid surfaces. Virtual Polymers Appended Onto Quantum Dots by Self-Assembly or Covalent Tethers: Coupling of Quantum Dots with QTL Bioassays [0059] The assembly of cyanine dyes (including, but not limited to, the chromophore of structures 10 and 15) or other molecules capable of forming aggregates onto a particle or surface provides a platform for biosensing based on superquenching. The superquenching can be controlled by the charge of the assembled film or the surface or a combination thereof. Biosensing may be accomplished either by fluorescence “turn-on” or “turn-off” assays and in direct and competition modes. While the assembly may have relatively strong light-absorbing properties, in a number of cases, the absorption of J-aggregates is very sharp and limited to a very narrow portion of the visible spectrum. A significant enhancement of light-harvesting properties may be obtained by constructing the assembly on top of a layer or particle having strong absorption (and high oscillator strength) at higher energies. This can be accomplished in Langmuir-Blodgett Assemblies and complex multilayered films built up by layer-by-layer deposition. [0060] The construction of an assembly of dyes or other molecules on a surface-capped semiconductor nanoparticle “quantum dot” offers a convenient and effective way of enhancing the biosensing capabilities of the virtual polymers described above. Although quantum dots have been investigated for several years, recent advances have made possible the preparation of quantum dots of high stability, variable size, versatile wavelength tunability for both absorption and emission properties, and controlled surface properties and functionality. Thus, it is possible to use an appropriately constructed and derivatized quantum dot as a support on which to construct a virtual polymer. The quantum dot “platform” is selected to have good energy donor properties towards a specific cyanine dye, cyanine dye aggregate, conjugated polymer oligomer, or other building block that can be used in a QTL bioassay. The combination affords an attractive, versatile, yet relatively simple way of enhancing the sensitivity and extending the wavelength range of the QTL biosensor. Both direct adsorption onto the quantum dot or covalent attachment or anchoring of dots and polymers on a microsphere surface may be used to construct the quantum dot-sensing ensemble. Examples of quantum dots include (but are not limited to) CdS, CdSe and ZnS. QTL Bioassays Based on Assemblies and Inclusion Complexes of Dye Monomers, Oligomers, and Conjugated Polymer Oligomers in Natural and Functionalized Polysaccharides [0061] A wide range of investigations have shown that the starch-derived polymers amylose and carboxymethylamylose (CMA), which consist of linear, unmodified or derivatized 1,4 glucose polymers, can form complexes with hydrophobic or amphiphilic molecules that can exist as moderately linear conformations. The complexed “guest” amphiphiles exhibit restricted mobility and, in some cases, a degree of protection from other reagents present in the same solution with the amylose (or CMA) and its guest. The entrapment is attributed to formation of a helical sheath of the glycoside which surrounds a guest within the cavity. Helices with different radii can be formed to entrap guests of different sizes. Unmodified amylose is overall neutral while CMA (which is reasonably easily synthesized with variable loading of the carboxymethyl groups) is anionic. Analogous derivatization processes are possible to prepare amylose derivatives with other functionalities and/or charge. Several amphiphilic or hydrophilic molecules incorporating dyes or aromatic chromophores and exhibiting low solubility in water or aqueous-organic mixtures can be solubilized in amylose or CMA solutions with the guest chromophores entrapped within amylose (or CMA). Among examples of the latter are photo- and thermochromic dyes, highly luminescent stilbene amphiphiles, and other photoreactive compounds. [0062] Amylose, CMA, and other polysaccharides can form complexes with strongly absorbing amphiphilic molecules including appropriately derivatized squaraine dyes, bissquaraines, and some conjugated polymer oligomers such as poly (phenyl)ethynyl oligomers. Structures of some of these compounds selected are shown in FIG. 4. In each case, the compounds are either actually or potentially highly fluorescent in homogeneous solution. Additionally, they are either insoluble in water or very slightly soluble. Structurally they are able to form complexes with either amylose, CMA, or other modified amylose polymers. When incorporated with a charged amylose polymer, they become soluble in water, strongly fluorescent, and somewhat protected from association (such as face-to-face interactions which quench fluorescence) and adventitious quenching by nonspecific interactions with other solutes. The ability of the amylose and CMA hosts to collect multiple guests allows the gathering of several molecules of the host chromophores shown in FIG. 4. The high oscillator strength of the chromophores allows excitonic interactions to occur even when the chromophores are not in direct contact. These excitonic interactions provide a way of forming another “virtual polymer” similar to those described above. This virtual polymer may be subject to quenching by electron transfer or energy transfer quenchers that are brought into close proximity with the amylose or CMA helix containing the guest dyes or oligomers. This association may be obtained through Coulombic interactions between the quencher and complex or by other interactions that lead to strong association. Targeted superquenching by these quenchers can thus be obtained for included molecules such as those shown in FIG. 4, even when the individual molecules are not subject to superquenching. As described above, it is straightforward to extend superquenching to the use of QTL bioconjugates and to apply these bioconjugates in extensions of the QTL fluorescence quench-unquench and competitive assay formats. [0063] The present invention is a further extension of the use of superquenching in biosensing. By co-locating a bioreceptor and a fluorescent polymer (or “assembled polymer”) on a surface or colloidal particle, the interaction between the two components (quencher (Q) of the QTL and the polymer ensemble) is rendered a specific interaction by the ligand-receptor binding. Thus, the assay is not dependent upon nonspecific charge-based interactions between the quencher and the polymer ensemble. An additional advantage of the present invention is the versatility afforded by the ability to control the co-located assembly of a specific polymer ensemble-receptor either spatially (for example, on a rigid support) or on different particles. This greatly expands the ability of the QTL approach to be used for multiplexing several target agents. [0064] All of the assay formats of this invention rely on a co-location of a fluorescent polymer (or fluorescent “self-assembled” polymer assembly) and an appropriate receptor for a target analyte on a support. The support can be a microsphere or nanoparticle, a membrane, cuvette wall or the surface of a microtiter plate or glass slide, or any surface that may be interrogated by continuous or intermittent sampling (illumination/detection). The direct advantage of this approach is that in each case, the superquenching occurs due to a specific ligand-receptor interaction. Several different examples are discussed in the following sections. Further, the assays may be carried out in operationally different formats depending upon the specific requirements. Displacement Competition Assay [0065] In the Displacement Competition Assay, the anchored fluorescent polymer-receptor is pretreated with the QTL conjugate, resulting in the binding of the QTL conjugate to the receptor and concurrent superquenching of the fluorescent polymer. As shown in FIG. 5, the actual analysis involves the addition of an analyte to the ensemble. The fluorescence of the polymer increases quantitatively (turn on) with the level of the target agent in the analyte sample. Suitable examples include proteins, viruses, bacteria, spores, cells, microorganisms, antibodies, antibody fragments, nucleic acids, and toxins. In this example, the assay may be homogeneous and the actual time for the assay may be controlled by the “off rate” of the QTL from the receptor. Direct Competition Assay [0066] As shown in FIG. 6, in the Direct Competition Assay, the anchored fluorescent polymer-receptor is treated with a mixture containing an analyte (an unknown amount of the target agent) and a known amount of QTL conjugate. The polymer fluorescence is quenched to an extent determined by the QTL:target agent concentration ratio. The stronger the fluorescence, the higher the concentration of the target agent. An advantage of this approach used is that the assay may be both homogeneous and near instantaneous. Since both the target agent and the QTL conjugate compete directly for “open” receptor sites, the response can be very rapid. [0067] In another formulation, the anchored fluorescent polymer-receptor is incubated with an analyte sample before the fluorescence intensity of the sample is measured. The sample is then treated (following rinse steps as necessary) with an excess of a QTL conjugate. The initial reading of fluorescence following treatment with the QTL conjugate shows quenching due to binding of the QTL conjugate to unoccupied receptor sites. The stronger the initial fluorescence quenching, the smaller the level of target agent. Monitoring the polymer fluorescence as a function of time provides additional confirmation of the binding of the target agent and its replacement by the QTL conjugate at the receptor. A “Turn on” Competitive Assay Based on Polymer-Biomolecule Combinations [0068] Polymers that contain reactive end groups (e.g., polymer 10) may be covalently linked to a variety of materials, including small molecules, other polymers, and biomacromolecules. The resulting “hybrid molecule” may have similar solubility and will generally have the same ability as the individual polyelectrolyte component to adsorb to a surface. These surfaces include slides or plates, oppositely charged polymer beads (such as, but not limited to, quaternary amine-derivatized polystyrene or sulfonated polystyrene), natural or synthetic inorganic supports such as clays or silica, charged membranes, semiconductor nanocrystals, and other porous materials. Thus, either independently or as a component of a mixture, the use of a hybrid molecule can afford the preparation of a supported assembly containing a highly fluorescent species subject to superquenching. The hybrid molecule may also be employed in a solution-phase assay. [0069] In one example, the carboxyl or amine terminus of an amino acid polymer such as polymer 10 may be linked to a primary amine of a protein or antibody or antibody fragment to give a fluorescent compound 23. (See FIG. 7). This compound can either be used in solution or can be deposited on a surface such as is described above. In either format, the biomolecule portion of compound 23 should retain its specific recognition function. Thus, treatment of compound 23 with a QTL bioconjugate results in formation of a complex that allows the quenching component to extinguish the fluorescence from compound 23. The exposure to molecules such as L or L′ that can compete with the QTL binding site can result in displacement of the bound QTL bioconjugate and a turning on of the fluorescence from compound. The most effective utilization of compound 23 will generally be on a surface or bead or other supported format where the aggregation of the fluorescent species can result in enhanced superquenching sensitivity. The hybrid molecule thus serves as a molecular or supramolecular (in supported formats) sensor whose function is shown schematically in FIG. 7. [0070] In another example, a sensor/assay may be achieved in a supported format by collecting individual (i.e., not covalently linked) polymer and biomolecule components on the same bead, particle, or nanostructure. For example, carboxyl functionalized beads or particles may be used both to covalently bind a protein, antibody, or antibody fragment via an amine group on the protein (as described above) and to bind a monomer (such as 15), oligomer or polymeric fluorescent dye such as 10 by adsorption or covalent attachment. Provided there is no significant quenching interaction between the dye ensemble and the biomolecule, the “dual coated” beads will be strongly fluorescent. Here again, a competitive fluorescence “turn-on” assay may be constructed by the use of a QTL bioconjugate that associates with the biomolecule. Further, the addition of the QTL bioconjugate will result in a quenching of the dye ensemble fluorescence. Addition of a reagent L or L′ that can compete with the QTL bioconjugate for the binding site will result in the expulsion of the QTL molecule from the bead or particle and an increase (or unquenching) of the dye ensemble fluorescence. Because the spatial range for quenching is increased, a preferred embodiment will be the case where Q is an energy transfer quencher. This will allow the quenching of all polymers within the Foerster transfer radius of the receptor-bound QTL molecule. For polymers bound on surfaces, this radius can be approximately 100 Angstroms or more. [0071] The dual coated beads or particles can also be used in a fluorescence “turn-off competitive or noncompetitive assay. Treatment of the beads (initially uncomplexed) with an antigen (L or L′) will result in the binding of the antigen to the biomolecule, but with negligible fluorescence changes. Addition of an aliquot of a QTL molecule that can bind, but not compete with L or L′ will result in a quenching of the polymer fluorescence in a “turn-off” response, that is proportional to the number of receptor sites not occupied by the antigen. A QTL molecule that can compete with antigen L or L′ will give a time-dependent response which can be used to measure both the level of antigen present and the strength of its binding to the biomolecule. [0072] The central component of the above-mentioned assays is the supported (and co-located) fluorescent polymer-receptor ensemble. They may be constructed (but is not limited to) as outlined in the following examples. In the first example, a receptor, or “receptor binding site” is covalently attached to a support. Subsequently a fluorescent polymer may be adsorbed onto the same support as illustrated in FIG. 8. Examples of receptors that may be covalently attached include proteins such as avidin, neutravidin or streptavidin or antibodies, peptides and nucleic acids. The degree of loading of both fluorescent polymer and receptor can be controlled to obtain sensors having varied sensitivity and dynamic range. In a second example, as shown in FIG. 9, both the polymer and receptor may be covalently tethered to the support. In another formulation, illustrated in FIG. 10, a polymer or oligomer doped with a reactive group is tethered to a receptor by a covalent linkage and adsorbed to a support. The polymer may be first adsorbed and then covalently linked to the receptor or vice versa. To take advantage of enhanced superquenching provided by “self-assembled” polymers, the fluorescent “polymer” ensemble can be constructed from monomers that may be collected by either self-assembly (adsorption) or covalent linkage. Depending upon the requirements of the assay and the component “polymer” and receptor, the receptor may be covalently linked to the support before or following generation of the self-assembled polymer. [0073] In addition to the assays based on direct binding of a QTL conjugate to the fluorescent polymer-receptor ensemble, assays may also be constructed based on secondary recognition events. For example, the current platforms can be extended to a sandwich format in which a target agent having multiple binding sites for the same or other receptor is sensed. This format is illustrated in FIG. 11. Binding of the target agent to a receptor site causes little or no change in the fluorescent polymer fluorescence. However, addition of a QTL conjugate which also binds to the receptor results in bringing the quencher close enough to quench the fluorescence in a direct assay. Such a sandwich assay can be adapted to sense a variety of agents including bacterial spores. [0074] Having generally described the invention, a further understanding can be obtained by reference to certain specific examples provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified. EXAMPLES Example 1 [0075] Commercial polystyrene beads containing streptavidin covalently tethered to the surface(0.53 micron microspheres purchased from Bangs Laboratories, Inc., Fishers, Ind.) were coated with the anionic conjugated polymer 24, a derivative of poly(phenyleneethynylene) (PPE) (structures 24-27 are shown in FIG. 12). The level of loading of 24 on the surface can be controlled depending on the loading of the polymer. The number of biotin binding sites (maximum biotin-FITC binding capacity=1.42 ug/mg of microspheres) is also variable and controllable. For an initial assessment of the ability of the coated microspheres to function in biosensing, a QTL conjugate formed of an energy transfer quencher (Alexafluor 594, purchased from Molecular Probes) was conjugated to the streptavidin ligand biotin. In separate studies it was demonstrated that nonspecific quenching of the polymer fluorescence by non-biotinylated Alexafluor 594 does not occur. Depending on the level of coating, the K SV was found to vary between 3×10 7 and 3×10 8 M −1 over two logs of QTL concentration. The level of the QTL detected by direct binding to the receptor in a conventional 96-well plate was less than 100 femtomoles. For this assay, it was determined that an intermediate level of polymer loading onto the beads gave optimal initial quench sensitivity and a wide dynamic range. (See FIG. 13). [0076] To generalize the assay using these beads, biotinylated antibodies can be used to tether specific receptors. The binding of the biotinylated antibodies produces little change in the fluorescence of the polymer. However, the addition of a conjugate recognized by the antibody and containing an energy transfer quencher does result in quenching of the polymer fluorescence. Thus, as shown in FIG. 14, it has been demonstrated that a biotinylated capture antibody can bind to an antibody-based QTL conjugate (target antibody derivatized with an energy transfer quencher) and be detected at levels less than one picomole). [0077] From this example, it is evident that the same beads can be used to construct a wide array of assays based on antibody-antigen interactions. In the general case, two additional components are required: a biotinylated antibody or other receptor and a QTL conjugate that is recognized by the antibody. All three of the assay paths described above can be used with these beads. The use of labeled beads (e.g., a polystyrene bead labeled in the interior of the bead with a fluorescent dye tag having distinct fluorescent wavelengths) or different polymers with different antibodies or receptors allows for the simultaneous assay of multiple target analytes. Example 2 [0078] A somewhat lower molecular weight PPE oligomer, monofunctionalized with carboxylate 25, was adsorptively coated on quaternary ammonium-derivatized polystyrene microspheres. Following deposition, rabbit anti-goat IgG antibodies were covalently linked to the polymer through the available carboxyl functionality. The fluorescence of the polymer remained strong following the antibody coupling and showed little sensitivity toward photobleaching. However, the fluorescence of the ensemble of oligomers was quenched specifically by the addition of goat anti-rabbit IgG conjugated to the fluorescent energy transfer quencher, Alexafluor 532. Fluorescence quenching could be detected at<500 fmole levels in a 96-well plate format. (See FIG. 15). Additionally, goat anti-rabbit IgG antibodies coupled with the nonfluorescent energy transfer quencher QSY35 also exhibited quenching on association with the bead-anchored polymer-antibody receptor. In this case, a K SV =8×10 7 M −1 was measured in the sub to few picomoles concentration range. Example 3 [0079] Cyanine dyes exhibit induced J-aggregation on anionic nanoparticles and microspheres. For simple cyanine monomers such as 26, adsorption onto clay or silica particles is reversible and thus individually coated particles coated with different cyanine dyes or cyanine mixtures exhibit exchange among the cyanines. It has been determined that the use of amphiphilic cyanine dyes such as the derivative of 26 where the N-ethyl groups have been replaced by N-octadecyl groups results in molecules that can be irreversibly adsorbed onto silica microspheres. Thus, individual amphiphilic cyanine dyes or mixtures of amphiphilic cyanines may be coated separately onto silica microspheres and then mixed with silica microspheres coated with other formulations of cyanine amphiphiles. The mixtures show no evidence of exchange of cyanines between different particles and thus permit the use of these mixtures for the simultaneous sensing of multiple agents. The use of energy accepting amphiphilic guests such as the corresponding amphiphilic cyanine to 4 results in the same emission wavelength shifting and affords the construction of several ensembles capable of emitting fluorescence at different wavelengths from the same host amphiphilic cyanine. [0080] The fluorescence of the aggregated cyanine dye may be quenched by either cationic or anionic energy accepting cyanine dyes or by electron transfer quenchers. This quenching can be tuned by varying the level of coating of the cationic cyanine dye on the anionic nanoparticle or microsphere. At low loading of the particle with a cationic cyanine, the particle has regions of exposed negative charge and positively charged quenchers are attracted (and exhibit high superquenching constants) while potential anionic quenchers show low quenching via these nonspecific interactions. At high loading of the particles, the situation is reversed and anionic quenchers show attractive but nonspecific interactions and consequent high quenching constants while cationic quenchers are ineffective. For clay nanoparticles, optimum results occur with near 100% coverage of the clay surface by a cyanine or cyanine mixture. At this level of coverage, selective quenching by anionic quenchers occurs. For cyanine dye aggregates on the clay nanoparticles, the most effective quenching occurs when like-charged cyanines are co-adsorbed. [0081] For example, the addition of energy accepting cationic cyanine 27 to excess cyanine 26 results in 50% quenching when the ratio of compound 26 to compound 27 ratio is 400:1. The quenching of 26 by 27 results in the sensitized emission of 27 and offers a potential advantage in separating the excitation and emission of the nanoparticle-supported ensemble. These particle-bound “self-assembled polymers” offer a convenient platform for sensing similar to those discussed above in Example 1 and 2. Coating of cyanine monomer or a mixture (such as 26 and 27) onto anionic microspheres or nanoparticles that already have a covalently anchored receptor such as streptavidin or an antibody can result in the formation of regions of J-aggregate or mixed aggregate on all accessible anionic surfaces of the support. This renders the ensemble overall slightly cationic and therefore of very low susceptibility to nonspecific association with cationic quenchers. However, cationic QTL conjugates can associate with the particles by specific ligand-receptor interactions in the same ways as described in the Examples 1 and 2 above. Thus, the superquenching of the self-assembled polymers can be harnessed in improved biosensing through specific association in the co-located receptor-self-assembled polymer ensembles. Example 4 [0082] The same kind of self-assembled polymers may also be constructed by covalent linkage of cyanine (or other monomers) onto a densely functionalized surface. As shown in FIG. 16 a, the same cyanine chromophore present in 26 can be constructed by covalent attachment in two stages. It has been determined that amine functionalized silica microspheres can form a platform onto which a high level of coverage can be obtained. For microspheres coated only with the monomer, it is found that, depending on the surface derivatization and reaction conditions, different populations of at least three species are obtained. The first species has absorption and fluorescence close to those of the monomer. A second, longer-wavelength absorbing species shows very similar absorption and emission to the J-aggregate of 26 described above. The third species exhibiting a somewhat broadened emission at longer wavelengths is usually not prominent in absorption but frequently includes the predominant emission, regardless of the wavelength at which the mixture is excited. It has been found that quenching by non-specific interactions can be observed for anionic electron transfer dyes (AQS-Biotin (5) (FIG. 2), K SV =3×10 7 M −1 ) and for a cationic energy transfer dye (QSY-21 (6) (FIG. 17), K SV =5.3×10 8 M −1 ) at subpicomole levels of quencher. In order to construct a sensor analogous to those described in the Examples above, the covalently-linked cyanine was constructed with varying amounts of an additional functionalized site containing a carboxyl group as shown in FIG. 16 b. Once the dye has been tethered to the surface, the carboxyl sites may be used to append a receptor as outlined in Example 2 set forth above. The appending of a receptor on the surface of the covalently tethered “self-assembled polymer” has the advantage of shielding the dye from non-specific association with potential quenchers and restricting quenching interactions to QTL conjugates associating specifically with the receptor. [0083] The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be the preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure. The invention is not otherwise limited, except for the recitation of the claims set forth below. References [0084] 1. L. Chen, D. W. McBranch, H.-L. Wang, R. Helgeson, F. Wudl and D. G. Whitten, “Highly-Sensitive Biological and Chemical Sensors Based on Reversible Fluorescence Quenching in a Conjugated Polymer”, Proc. Nat'l Acad. Sci. USA, 96:12287 (1999). [0085] 2. L. Chen, D. McBranch, R. Wang and D. G. Whitten, “Surfactant-Induced Modification of Quenching of Conjugated Polymer Fluorescence by electron Acceptors: Applications for chemical Sensing”, Chem. Phys. Lett., 330:27-33 (2000). [0086] 3. L. Chen, S. Xu, D. McBranch and D. G. Whitten, “Tuning the Properties of Conjugated Polyelectrolytes Through Surfactant Complexation”, J. Am. Chem. Soc., 122:9302-9303 (2000). [0087] 4. D. Whitten, L. Chen, R. Jones, T. Bergstedt, P. Heeger, D. McBranch, “From Superquenching to Biodetection; Building Sensors Based on Fluorescent Polyelectrolytes” in “Molecular and Supramolecular Photochemistry, Volume 7: Optical Sensors and Switches”, Marcel Dekker, new York, eds. V. Ramamurthy and K. S. Schanze, Chapter 4, pp 189-208 (2001). [0088] 5. R. M. Jones, T. S. Bergstedt, C. T. Buscher, D. McBranch, D. Whitten, “Superquenching and its applications in J-aggregated cyanine polymers”, Langmuir, 17:2568-2571 (2001). [0089] 6. L. Lu, R. Helgeson, R. M. Jones, D. McBranch, D. Whitten, “Superquenching in cyanine pendant poly-L-lysine dyes: dependence on molecular weight, solvent and aggregation”, J. Am. Chem. Soc., in press. [0090] 7. R. M. Jones, T. S. Bergstedt, D. W. McBranch, D. G. Whitten, “Tuning of Superquenching in layered and mixed fluorescent polyelectrolytes”, J. Am. Chem. Soc., 123:6726-6727 (2001). [0091] 8. R. M. Jones, L. Lu, R. Helgeson, T. S. Bergstedt, D. W. McBranch, D. Whitten, “Building highly sensitive dye assemblies for biosensing from molecular building blocks”, Proceedings Nat'l. Acad. Sci. USA, 98:14769-14772 (2001).

A chemical composition including a fluorescent polymer and a receptor that is specific for both a target biological agent and a chemical moiety including (a) a recognition element, (b) a tethering element, and (c) a property-altering element is disclosed. Both the fluorescent polymer and the receptor are co-located on a support. When the chemical moiety is bound to the receptor, the property-altering element is sufficiently close to the fluorescent polymer to alter the fluorescence emitted by the polymer. When an analyte sample is introduced, the target biological agent, if present, binds to the receptor, thereby displacing the chemical moiety from the receptor, resulting in an increase of detected fluorescence. Assays for detecting the presence of a target biological agent are also disclosed.

CROSS REFERENCE TO RELATED APPLICATION This application is a National Stage applicaton of International Application No. PCT/AU2005/001784, with and international filing date of Nov. 25, 2005. FIELD OF THE INVENTION The present invention relates to lasers. In one particular form the present invention relates to a distributed feedback (DFB) fibre laser having improved characteristics for use in fibre laser arrays. BACKGROUND OF THE INVENTION DFB lasers are a variety of lasers which include one or more Bragg gratings which act as reflection elements within a laser active region. This technique of co-locating the gain medium and the feedback grating is applicable to fibre lasers such as those which employ a gain medium that has been doped with erbium. An example of a prior art DFB fibre laser is illustrated in FIG. 1 . Fibre laser 100 includes a doped fibre 110 and Bragg grating 120 incorporating a phase discontinuity located in the middle section 130 of grating 120 . The Bragg grating is provided by a UV induced periodic spatial variation of the refractive index of the gain medium. Other techniques which provide a Bragg grating structure include periodic modulation of the gain or loss of the active region or potentially the cutting of a periodic pattern of grooves into the cladding of the fibre might also conceivably be used. Fibre laser 100 is activated by optical pumping 140 which involves pumping light having a wavelength that matches with the appropriate absorption band of the active material or gain medium through a passive fibre connected to fibre laser 100 . This arrangement of the Bragg grating 120 and gain medium provides optical feedback at approximately the Bragg wavelength λ B characterised by the relation λ B =2n eff Λ where Λ is the period of the grating and n eff is the effective refractive index of the fibre mode. The grating is characterised by a complex coupling coefficient κ(z)=πΔn(z)e −iφ(z) /λ where Δn is the refractive index modulation and φ(z) is the phase error associated with the grating and where z is a measure of the longitudinal distance along the fibre. Accordingly the spectral width of the grating reflection is proportional to |κ|. As illustrated figuratively in FIG. 2 , a π phase shift is introduced into the middle section 130 of grating 120 . The introduction of this phase shift ensures a lowest threshold, highly confined fundamental laser mode operating at essentially the Bragg wavelength λ B . The typical field distribution of such a laser is shown in FIG. 3 where it can be seen that the field has a maximum at the location of the phase shift and decays exponentially away from the centre of grating 120 . The spatial width of the field distribution depends on |κ| and defines the overall device length L which in practice is usually a few centimeters. One of the major applications of a DFB fibre laser is to incorporate a number of fibre lasers into one continuous fibre to form a fibre laser array. Each of the fibre lasers are tuned to operate at slightly different wavelengths λ B 1 , λ B 2 etc with the advantage that optical pumping at a single wavelength may be employed to cause each of the DFB fibre laser sections to lase. This provides a means for wave division multiplexing as laser emissions from each fibre laser section travel down the common fibre and may be sampled using interferometric processing downstream. Arrays of DFB fibre lasers of this type have been employed in a number of applications including sensor arrays where the wavelength output of each fibre laser varies according to the local value of a physical characteristic of the environment such as the temperature or level of sound, to uses such as multi-wavelength laser sources. Clearly, the ability of each fibre laser section to emit light essentially at the respective Bragg wavelength is critical as each of the wavelengths λ B 1 , λ B 2 etc. will be tightly spaced due to the finite emission band-width available to the gain medium, which must be similar for each laser due to the requirement that each fibre laser is activated by pump light having the same wavelength. However, DFB fibre lasers have a number of disadvantages which directly affect the performance of fibre laser arrays based on a number of fibre laser sections. Although the Bragg grating is designed to reflect light in only a narrow band about the Bragg wavelength λ B and to be essentially transparent outside the band there is in practice out of band reflection associated with the side-lobes of the Bragg grating. The out of band reflection r(ν) is characterised by the relationship, r ⁡ ( v ) = - ∫ 0 L ⁢ κ ⁡ ( z ) · exp ⁡ ( - ⅈ ⁢ ⁢ 2 ⁢ π ⁢ ⁢ vz ) ⁢ ⁢ ⅆ z where ν is the detuning from the Bragg frequency and is defined by v = 2 ⁢ n eff · [ 1 λ - 1 λ B ] for ν>|κ|. When two or more DFB fibre lasers are connected to the same fibre, this out of band reflection results in a fraction of light from a given fibre laser section being reflected by another fibre laser section thereby causing a shift Δλ from the Bragg wavelength λ B for that particular fibre laser section. For distance d between each fibre laser section this wavelength shift is approximated by Δλ=λ B 2 κ| r|e −κL sin(2 πd/λ B −φ r )/π where φ r is the phase of the out of band reflection r(ν) (i.e. r(ν)=|r|e iφ r ) from the adjacent laser. Accordingly, the laser wavelength will be sensitive to both small changes in distance d between the fibre laser sections and the reflection coefficient r(ν) from the adjacent lasers. Clearly, this is undesirable in the example of a sensor array as the intent is to measure changes to the laser wavelength caused by local changes to the Bragg wavelength of the grating of the respective fibre laser section. To address this issue of undesirable wavelength sensitivity, the physical length L of the grating structure can be increased. However, this has the obvious disadvantage of lengthening the fibre laser array where compactness is often a major requirement. In addition where the fibre laser sections are being employed in a sensor array such as an acoustic sensor, lengthening of each fibre laser section implies that a sample is taken from a distributed region as opposed to the fibre laser section acting as a point sensor. Often a sensor design will also require multiple point sensors in close proximity and lengthening the grating structure for each fibre laser section can greatly add to the mechanical constraints in dealing with such a sensor array. It is an object of the invention to provide a DFB laser having improved characteristics that enable the incorporation of these devices into multiple DFB laser arrangements. SUMMARY OF THE INVENTION In a first aspect the present invention accordingly provides a laser element for producing laser light including: an active medium excited by optical pumping means to produce stimulated emission of light; and a Bragg grating structure for providing optical feedback for said active medium, said Bragg grating structure including a phase transition region providing a change in phase, wherein said change in phase of said phase transition region is adjusted to modify out of band reflection of said laser element. By modifying the out of band reflection characteristics of the laser element the laser element may be customised for incorporation into a system incorporating an array of multiple laser elements. Preferably, said change in phase is adjusted to reduce out of band reflection of said laser element. Preferably, said change in phase is adjusted to continuously change over an extended region of said laser element. Preferably, a maximum phase change ΔΦ of said change in phase is greater than π. Preferably, said maximum phase change ΔΦ of said change in phase is determined in part by a length of said extended region. Preferably, said maximum phase change ΔΦ increases as said length of said extended region increases. Preferably, said change in phase is characterized by a function φ(z)=ƒ 1 (z)ΔΦ where z is the length along the laser element and ƒ 1 (z) is a function that varies smoothly from 0 to 1. Preferably, said maximum phase change ΔΦ is determined by solving the coupled equations for ΔΦ and auxiliary function q(z): ΔΦ = π + 2 ⁢ ∫ z 2 z 3 ⁢ κ ⁡ ( z ) ⁢ sin ⁡ ( q ⁡ ( z ) ) ⁢ ⁢ ⅆ z q ⁡ ( z ) = ΔΦf 1 ⁡ ( z ) - 2 ⁢ ∫ z 2 z ⁢ κ ⁡ ( z ′ ) ⁢ sin ⁡ ( q ⁡ ( z ′ ) ) ⁢ ⁢ ⅆ z ′ where κ(z) is a coupling coefficient of said Bragg grating structure; and z 2 and z 3 define the boundaries of said phase transition region. Optionally, said maximum phase change ΔΦ of said smooth change in phase is determined by ΔΦ - 2 · ∫ z 2 z 3 ⁢ κ ⁡ ( z ) · sin ⁡ ( ΔΦ ) ⁢ ⁢ ⅆ z = π where κ(z) is a coupling coefficient of said Bragg grating structure; and z 2 and z 3 define the boundaries of said phase transition region. Preferably, said laser element is a distributed feedback (DFB) fibre laser (FL) In a second aspect the present invention accordingly provides a method for producing laser light from a laser element, said method including the steps: optically pumping an active medium to produce stimulation emission of light; and adjusting a change in phase of a phase transition region of a Bragg grating structure providing optical feedback for said active medium to modify out of band reflection of said laser element. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention will be discussed with reference to the accompanying drawings wherein: FIG. 1 is a figurative representation of a distributed feedback (DFB) fibre laser (FL) as known in the prior art; FIG. 2 is a depiction of the π phase shift introduced in the central lasing region of the DFB FL illustrated in FIG. 1 ; FIG. 3 is an example plot of the field distribution of the DFB FL as illustrated in FIG. 1 ; FIG. 4 is a plot of the amplitude and phase apodisation profiles according to a preferred embodiment of the present invention; FIG. 5 is a plot of the field distribution of an apodised DFB FL laser when modified according to the apodisation profiles illustrated in FIG. 4 compared to the field distribution of standard DFB FL; and FIG. 6 is a comparison plot of the measured spectral reflection curve of a non-apodised and apodised DFB FL modified according to the apodisation profiles illustrated in FIG. 4 . DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 4 , there is shown a modification of a phase transition region of a distributed feedback fibre laser (hereinafter a DFB FL) according to a preferred embodiment of the present invention. Whilst in this preferred embodiment the phase transition region of a DFB FL has been modified, it would be apparent to those skilled in the art that the invention may be equally applied to modify the out of band reflection characteristics of other varieties of Bragg grating lasers which incorporate central phase transition regions where the phase rapidly varies. DFB FL is assumed to be of length L and is divided into five regions corresponding to first region ranging from 0<z<z 1 , second region z 1 <z<z 2 , third region z 2 <z<z 3 , fourth region z 3 <z<z 4 and fifth region z 4 <z<L where z measures longitudinal extent along the fibre. Apodisation is applied to both the amplitude and phase of the grating coupling coefficient κ(z). Phase apodisation is applied to the third region which would typically be a step function in a prior art DFB FL such as that illustrated in FIG. 1 . According to this preferred embodiment of the present invention, a continuous phase transition φ(z) is introduced which is defined by the relationship φ(z)=ƒ 1 (z)ΔΦ with the boundary conditions ƒ 1 (z 2 )=0 and ƒ 1 (z 3 )=1. In this embodiment ƒ 1 (z) is chosen to achieve best reflection suppression on the defined transmission length z 3 −z 2 and is defined by f 1 ⁡ ( z ) = cos n ⁡ ( π ⁢ ⁢ z 2 ⁢ ( z 3 - z 2 ) - π 2 ⁢ ( z 3 - z 2 ) ) for n=2, 4, etc. Depending on the apodisation requirements, other suitably defined smooth transition functions which vary from 0 to 1 and whose derivatives vanish at the relevant boundaries may be employed. The value for the constant ΔΦ is determined by solving numerically the following coupled equations thereby determining the value of ΔΦ that ensures optimal single mode performance at the Bragg frequency. ΔΦ = π + 2 ⁢ ∫ z 2 z 3 ⁢ κ ⁡ ( z ) ⁢ sin ⁡ ( q ⁡ ( z ) ) ⁢ ⁢ ⅆ z q ⁡ ( z ) = ΔΦ ⁢ ⁢ f 1 ⁡ ( z ) - 2 ⁢ ∫ z 2 z ⁢ κ ⁡ ( z ′ ) ⁢ sin ⁡ ( q ⁡ ( z ′ ) ) ⁢ ⁢ ⅆ z ′ For the derivation of these equations see in particular Equation 19 as described in the article entitled “Experimental and Theoretical Characterisation of the Mode Profile of Single-Mode DFB Fiber Lasers” (IEEE Journal of Quantum Electronics, Vol. 41, No. 6, June 2005) which is herein incorporated by reference in its entirety. These coupled equations are then solved iteratively for ΔΦ for reasonable choices of ƒ 1 (z) such as that described above. In certain cases where ΔΦ is close to π, then the first order approximation ΔΦ - 2 · ∫ z 2 z 3 ⁢ κ ⁡ ( z ) · sin ⁡ ( ΔΦ ⁢ ⁢ f 1 ⁡ ( z ) ) ⁢ ⁢ ⅆ z = π may be adequate. Whilst in this preferred embodiment ΔΦ, has been calculated according to the above relationships, clearly other values may be calculated and used according to the exact tuning requirements of the DFB FL being contemplated. According to these calculations, the phase shift step value or maximum phase change ΔΦ will always be greater than π. As would be appreciated by those skilled in the art, for prior art DFB FLs the optimal condition for single mode performance whereby the optimum amount of energy is confined in one mode has always incorporated a phase shift step value or maximum phase change of π. Additionally the amplitude |κ(z)| of grating coupling coefficient may also be modified. Referring again to FIG. 4 , |κ(z)| is modified according to the relationship |κ(z)|=ƒ 2 (z)·|κ 0 | where ƒ 2 (0)=ƒ 2 (L)=0 and ƒ 2 (z)=1 for z 1 <z<z 4 . For first and fifth regions ƒ 2 (z) is defined in a similar manner to ƒ 1 (z). Whilst amplitude apodisation of this nature is known in the prior art it does not in of itself successfully address issues with out of band reflection as highlighted previously. However, it may be employed in addition to phase apodisation according to the present invention to further reduce the effects of side lobes thereby resulting in minimised out of band reflection in a fibre laser section. Referring now to FIG. 5 , a calculated curve for the field distribution of a DFB FL which has been apodised according to the present invention is compared with the field distribution of a corresponding standard DFB FL. For this embodiment, the region z 3 −z 2 corresponds to 0.2 L. Although the phase shift region has now extended in size to occupy approximately 20% of the device length, the associated increase in the laser mode width and hence overall device length is only 4% and as such only represents a very small increase. Referring now to FIG. 6 , plot B depicts the measured spectral reflection curve from a DFB FL apodised according to the present invention and employing parameters κ 0 =1.9 cm −1 and ΔΦ=4.5 radians thereby illustrating that reflection values of less than −50 dB are achievable. For comparison, plot A depicts the spectral reflection curve for a non-apodised laser of the prior art. Accordingly, this invention makes it possible to achieve very low out of band reflectivity without having to substantially increase the total device length thereby making DFB FLs adopting this invention most suitable for incorporation in linear multiplexed fibre laser arrays. The invention partly resides in realising that scattering from the normal discrete π phase shift employed in standard DFB FL contributes substantially to the spectral reflection curve. According to the present invention, adjusting and modifying the shape and/or associated magnitude of this phase shift is important when attempting to substantially reduce the out of band spectral reflection. Although a preferred embodiment of the present invention has been described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiment disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.

A method and apparatus for modifying the out of band reflection of a laser element is described. The laser element includes an active medium excited by optical pumping means to produce stimulation emission of light. The laser element further includes a Bragg grating structure for providing optical feedback for the active medium, with the Bragg grating structure including a phase transition region providing a change in phase. The change in phase of the phase transition region is adjusted to modify out of band reflection of said laser element.

RELATED APPLICATION This application is a continuation of International Application No. PCT/GB2009/002353, which designated the United States and was filed on Oct. 2, 2009, which claims priority under 35 U.S.C. §119 or 365 to United Kingdom Application No. 0818077.0, filed on Oct. 2, 2008. The entire teachings of the above applications are incorporated herein by reference. FIELD OF THE INVENTION In devices for the programmed delivery of therapeutic products into the human or animal body, there is generally provided a pressurised reservoir of therapeutic product working in cooperation with a pumping chamber and valve means. The therapeutic product is typically pumped by the device through a tube to a cannula that pierces the patient's skin. The device can be capable of providing a variable rate of infusion of the therapeutic product to the patient over several days. This invention is directed to an improved displacement sensor for the pressurised reservoir. BACKGROUND TO THE INVENTION Many different measurement techniques have been used previously as the basis for displacement sensors. In one type of displacement sensor the action of linearly or rotationally displacing a wiper of a potentiometer is converted to a voltage and/or current signal. Such potentiometric sensors often suffer from the problems of mechanical wear, frictional resistance in the wiper action, limited resolution in wire-wound units, and high electronic noise. Linear Variable Displacement Transducers (LVDT) are commonly available. An LVDT typically includes three coils of wire wound on a hollow form. A core of permeable material can slide freely through the centre of the form. The inner, primary coil is excited by an ac source. Flux formed by the primary coil is linked to two outer, secondary coils, inducing an ac voltage in each coil depending on the position of the core. If the two secondary coils are wired in series opposition then the two voltages will subtract; that is, a differential voltage is formed. When the core is centrally located, the net voltage is zero. When the core is moved to one side, the net voltage amplitude will increase. In addition, there is a change in phase with respect to the source when the core is moved to one side or the other. Additionally, these devices require separate coils at either end of the measurement coils to provide electrical shielding to create a low noise transducer. These manufacturing requirements make these transducers expensive to manufacture and have a length dimension at least twice the distance they can measure. A number of devices have also been described based on optical measurement systems such as optical encoders. Devices based on ultrasonic techniques have also been described. These devices tend to be expensive to manufacture and are restricted in the type of application in which they can be employed. A variety of capacitance based displacement sensors have been described for measuring or detecting linear displacements. One type of capacitance displacement sensor is based on the principle of two opposing plates, where measurement of displacement either alters the overlapping area of the two plates or changes the dielectric properties of the gap between the plates. Examples of this type of displacement sensor are offered below. GB 1275060 A discloses a displacement sensor comprising of guided rod forming a first plate of the capacitor and a receptor tube in which the rod moves in and out forming a second pate of the capacitor. U.S. Pat. No. 4,961,055 discloses a displacement sensor similar to that of GB 1275060 A and further discloses a third tube that acts to shield the sensing plate of the capacitor from electrostatic charges, which can cause signal noise. A number of other moving plate capacitor sensors have also been described that utilise patterns of electrodes on either flat or tubular plates. Examples of these are given by JP 8-159704 and GB 2273567 A. The construction of these devices also presents considerable challenges in manufacturing inexpensive devices. The use of capacitance displacement sensors has been described for a variety of applications including monitoring fluid levels in reservoirs, as disclosed in EP 0520201 A. U.S. Pat. No. 5,135,485 discloses a capacitance measurement employed in a drug reservoir to either detect when the reservoir is empty or provide a measure of the level of liquid in the reservoir. The sensor described for monitoring the level of liquid in the reservoir comprises two plates of a capacitor with the liquid forming the dielectric between them. The greater the quantity of liquid present in the reservoir the more the gap between the plates becomes filled with the liquid and this is reflected in the capacitance measured by the sensor. U.S. Pat. No. 6,210,368 discloses a capacitor based sensor that monitors liquid levels in a reservoir. In one embodiment an amount of overlap between two plates of a capacitor changes as the reservoir volume changes. In another embodiment an amount of liquid phase propellant absorbed in a dielectric material of a capacitor changes according to the reservoir volume, causing a change in the dielectric properties of the capacitor. U.S. Pat. No. 6,352,523 discloses a method for measuring the amount of insulin remaining in a syringe after an administration based on a barrel and plunger of a syringe being adapted as the two plates of a coaxial capacitor. The device additionally requires that the syringe is placed into a reader to generate the displacement information. Alternative techniques for monitoring levels of a drug in a reservoir include the use of optical encoders. U.S. Pat. No. 4,498,843 and WO2004/009163 both describe a linear displacement measurement system based on an optical encoder that is used to monitor the position of a syringe barrel as part of an infusion system. There is a need in the art for a displacement sensor capable of monitoring the level of liquid in a syringe type drug reservoir with sufficient sensitivity as to allow detection of erroneous drug delivery. It is also required that the sensor is inexpensive to manufacture and provides reliable performance through robust design. SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a linear capacitance displacement transducer comprising a first cylindrical capacitor plate, a second cylindrical capacitor plate disposed around the first cylindrical capacitor plate so as to form a space between the first and second cylindrical capacitor plates, the first and second cylindrical capacitor plates being substantially spatially fixed relative to one another, and a third cylinder composed of dielectric material moveable longitudinally within the space such that a proportion of said space filled with the dielectric material can be altered relative to a fixed electric field created, in use, between the first and second cylindrical capacitor plates. According to a second aspect of the present invention there is provided a reservoir for containing a volume of fluid bound in part by an moveable element, in combination with a linear capacitance displacement transducer for measuring the volume of fluid contained in the reservoir, the displacement transducer comprising a fixed structure including first and second capacitor plates, and a dielectric structure moveable longitudinally within a space between the first and second capacitor plates, wherein the moveable dielectric structure is operatively coupled to the moveable element. According to a third aspect of the present invention there is provided an infusion system for infusion of liquid therapeutic product, including a linear capacitance displacement transducer according to the first aspect, or a linear capacitance displacement transducer in combination with a reservoir according to the second aspect. In the linear capacitance displacement transducer the electric field created, in use, between the first and second capacitor plates remains stationary whilst the proportion of the space between these plates that is filled with high dielectric material is altered by movement of the dielectric structure. This construction is advantageous in that since the first and second capacitor plates are substantially spatially fixed relative to one another, electrical connections for connecting thereto do not need to move thereby simplifying and making more robust the transducer and improving the reliability of a signal output by the transducer. Additionally, since the second capacitor plate is substantially spatially fixed relative to the electric field created, in use, the second plate acts as an effective shield against adverse external electrical influences. In a preferred embodiment of the invention, the fixed structure of the linear capacitance displacement transducer is a durable portion, whereas the reservoir and the moveable structure of the linear displacement transducer are a disposable portion, of an infusion system. In this manner, a disposable reservoir initially containing liquid therapeutic product may be formed integrally with the dielectric portion of the transducer to be fitted onto the durable portion of the infusion system having the electrical portion of the transducer. This allows a highly accurate transducer measurement to be made whilst keeping the manufacturing cost of the disposable portion of the infusion system low. BRIEF DESCRIPTION OF THE DRAWINGS Examples of the present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a schematic view of an embodiment of the linear capacitance displacement transducer in accordance with the invention, shown in an extended position; FIG. 2 is a schematic view of the transducer of FIG. 1 , shown in a retracted position; and FIG. 3 is a schematic view of an infusion system comprising a reservoir and a transducer in accordance with an embodiment of the invention. DETAILED DESCRIPTION Turning firstly to FIG. 1 , the linear capacitance displacement transducer 1 includes a first capacitor plate 2 and a second capacitor plate 3 defining a space 4 between the first and second capacitor plates 2 , 3 . The displacement transducer 1 further includes a dielectric structure 5 movable longitudinally within the space 4 in the direction of arrows X. The first and second capacitor plates 2 , 3 are electrically and physically connected to a printed circuit board or similar layer 6 having a semiconductor integrated circuit 7 , such as AD7746, mounted thereon. The dielectric structure 5 is operatively coupled to a movable element 8 . The movable element 8 is connected to guide means 9 cooperating with guide means 10 extending from the printed circuit board 6 . In the preferred embodiment shown in FIG. 1 the first capacitor plate 2 is a solid right circular cylinder disposed coaxially and concentrically with a hollow right circular cylinder of the second capacitor plate 3 . It will be appreciated by those skilled in the art that the first and second capacitor plates 2 , 3 need not necessarily be cylinders but may instead be flat plates, for example. Cylindrical capacitor plates are preferred as the outer, second cylindrical capacitor plate 3 effectively shields the fixed electric field created, in use, between the first and second cylindrical capacitor plates 2 , 3 . It will also be appreciated by those skilled in the art that the first and second capacitor plates 2 , 3 need not be right circular cylinders and may instead take solid or hollow hexagonal, octagonal or other polygonal or irregular forms. The first and second cylinders 2 , 3 need not be-disposed concentrically but it is preferred that they are so such that the electric field created is substantially uniform within a cross-section of the transducer 1 . In the preferred embodiment shown in FIG. 1 , the first and second capacitor plates 2 , 3 are of substantially the same length. However, it is envisaged that in alternative embodiments, the first and second capacitor plates 2 , 3 may be of different lengths and in particular the second cylinder 3 may be longer than the first cylinder 1 to provide more effective shielding against electrostatic interference. The guide means 10 may have a further function as a fourth cylinder disposed around the second cylindrical capacitor plate 3 for providing additional shielding against electrostatic interference to further improve the signal quality of the transducer 1 . The first and second capacitor plates 2 , 3 are physically connected to the printed circuit board 6 which acts as a support structure for supporting adjacent ends of the first and second capacitor plates 2 , 3 . It will be appreciate by those skilled in the art that a support structure other than the printed circuit board 6 may be provided as the physical connection at those ends of the first and second capacitor plates 2 , 3 , and wiring may be provided to a separate printed circuit board. However, to achieve space saving and drive down manufacturing costs the printed circuit board 6 acts as the physical support structure for the first and second capacitor plates 2 , 3 . The first and second capacitor plates 2 , 3 are electrically isolated and connected to the printed circuit board having the integrated circuit 7 for performing conversion of a capacitance signal output by the first and second capacitor plates 2 , 3 . Integrated circuit 7 also performs analog to digital conversion of the raw capacitance signal output by the first and second capacitor plates 2 , 3 . The AD7746 integrated circuit is provided as a purely exemplary integrated circuit and it will be appreciated by those skilled in the art that other circuits may be used in the alternative. To increase the effective surface area of the capacitor plates 2 , 3 , these may have a fluted surface. To ensure that the dielectric structure 5 is reliably retained between the first and second capacitor plates 2 , 3 the dielectric structure 5 may also be provided with a fluted surface. It is intended that the dielectric structure is slidably movable within the space 4 by a clearance fit with the capacitor plates 2 , 3 but leaving little, if any, play. In some preferred applications, the dielectric structure may be biased into or from the space 4 in the longitudinal direction. The bias may be provided by a spring or other such means and is particularly suitable where the movable member 8 connected to the distal end of the dielectric structure 5 constitutes a part of a reservoir or the like, a plunger of which is displaced and the transducer 1 measures that displacement. The linear capacitance displacement transducer 1 is shown in a retracted position in FIG. 2 in which the dielectric structure 5 occupies substantially all of the space 4 between the first and second capacitor plates 2 , 3 . As the dielectric structure 5 moves between the fully extended and retracted positions of FIGS. 1 and 2 , respectively, the proportion of the space 4 between the first and second capacitor plates 2 , 3 that is filled with the dielectric material 5 changes between a minimum and a maximum. The capacitance signal output by these first and second capacitor plates 2 , 3 can be calibrated to the linear displacement of the movable member 8 according to the change in capacitance as the movable element 8 moves between the fully extended and fully retracted positions. In this manner, the position and relative displacement of the movable element 8 can be measured by interrogating the capacitance signal. The linear capacitance displacement transducer 1 of the invention has broad application to a variety of devices. This may include displacement of a piston within its cylinder, displacement of a bowden cable, displacement of a linear switch, and the like. Its application is almost boundless and many other uses will be readily appreciated by those skilled in the art. However, a particular application of the linear capacitance displacement transducer in accordance with the invention is in combination with a reservoir for containing a volume of fluid bound in part by a movable element, such as a plunger. The plunger may be, or may be attached to, the movable element 8 described with reference to the linear capacitor displacement transducer 1 of FIGS. 1 and 2 . The reservoir and transducer 1 in combination may form a fixed structure including the first and second capacitor plates 2 , 3 , and the dielectric structure 5 movable longitudinally within the space 4 between the first and second capacitor plates 2 , 3 . The movable dielectric structure 5 is operatively coupled to the movable element 8 as described previously. The fixed structure of the transducer may form a durable part, and the reservoir and the movable structure of the transducer may form a disposable part, with the movable element of the reservoir being integrally formed with the movable structure. Such a combination is particularly suitable for use in an infusion system for infusion of liquid therapeutic product. The infusion system shown in FIG. 3 includes a pressurised reservoir 101 of therapeutic product 102 . The therapeutic product 102 is pressurised within the reservoir by application of a force, indicated by 103 , on a plunger 104 movable within the reservoir cavity. An outlet 105 of the reservoir is connected to an inlet of a micropump 106 . Means for fluidically coupling the micropump 106 to a human or animal body to which the therapeutic product is to be delivered is connected at one end to a patient, and at the other end to an outlet 107 of the micropump 106 . This means may be a cannular or other similar device. In the micropump 106 , the fluid inlet 105 leads to an inlet valve 108 . Operation of an actuator 109 having a gearing assembly causes a change in volume of a pumping chamber 110 . Upon increasing the volume of the pumping chamber 110 by operation of the geared actuator 109 the inlet valve 105 opens and fluid flows from the inlet 105 through the inlet valve 108 to fill the pumping chamber 110 . Once the pumping chamber 110 is full, operation of the geared actuator 109 to produce the volume of the pumping chamber 110 forces the fluid along a conduit 111 to an outlet valve 112 . Since the fluid passing through the conduit 111 is under pressure from the geared actuator 109 , the outlet valve 112 opens and fluid exits the pump 106 via outlet 107 . The inlet and outlet valves 108 , 112 are one way valves such as described in the applicant's co-pending UK patent application GB 0621343.3, the contents of which are incorporated herein by reference. The actuator, which may be a geared actuator 109 , such as described in applicant's co-pending UK patent application GB0621344.1, the contents of which is incorporated herein by reference. The one way valves 108 , 112 are such that upon a decrease in the volume of the pumping chamber 110 fluid therein does not pass through the inlet valve 108 to the inlet 105 and only passes along the conduit 111 . Also, the outlet valve 112 closes when the pressure in the fluid in the conduit 111 decreases below a predetermined value. Repeated operation of the geared actuator 109 causes fluid to be pumped from the inlet 105 to the outlet 107 . The actuator 109 is preferably controlled by an electronics module (not shown) that works in cooperation with at least one flow rate indicator to ensure programmed delivery of the therapeutic product with a high degree of accuracy. The at least one flow rate indicator may be derived from an output of the linear capacitance displacement transducer 1 of the present invention. Various modifications of the invention are envisaged as will be appreciate by the skilled person without departing from the scope of the invention, which is defined by the appended claims.

A linear capacitance displacement transducer ( 1 ) comprising first ( 2 ) and second ( 3 ) fixed capacitor plate and a dielectric structure ( 5 ) moveable longitudinally within a space ( 4 ) between the first ( 2 ) and second ( 3 ) capacitor plates, the dielectric structure ( 5 ) being operatively coupled to a moveable element ( 8 ). The capacitor plates and the dielectric material may be cylindrical and disposed coaxially and concentrically. The transducer ( 1 ) enables a displacement sensor that is capable of monitoring liquid levels in a syringe type drug reservoir ( 101 ) with sufficient sensitivity as to allow detection of erroneous drug delivery. The sensor is inexpensive to manufacture and provides reliable performance through robust design.

CROSS-REFERENCE TO RELATED APPLICATION This application is based, and claims priority under 35 U.S.C. §120 to U.S. Provisional Patent Application No. 61/059,837 filed on Jun. 9, 2008, and which is incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to methods of using compounds as disclosed herein to treat pain. BACKGROUND OF THE INVENTION Clinical pain encompasses nociceptive and neuropathic pain. Each type of pain is characterized by hypersensitivity at the site of damage and in adjacent normal tissue. While nociceptive pain usually is limited in duration and responds well to available opioid therapy, neuropathic pain can persist long after the initiating event has healed, as is evident, for example, in the “ghost pain” that often follows amputation. Chronic pain syndromes such as chronic neuropathic pain are triggered by any of a variety of insults, including surgery, compression injury or trauma, infectious agent, toxic drug, inflammatory disorder, or a metabolic disease such as diabetes or ischemia. Unfortunately, chronic pain such as chronic neuropathic pain generally is resistant to available drug therapy. Furthermore, current therapies have serious side-effects such as cognitive changes, sedation, nausea and, in the case of narcotic drugs, addiction. Many patients suffering from neuropathic and other chronic pain are elderly or have medical conditions that limit their tolerance to the side-effects associated with available analgesic therapy. The inadequacy of current therapy in relieving neuropathic pain without producing intolerable side-effects often is manifest in the depression and suicidal tendency of chronic pain sufferers. As alternatives to current analgesics, α 2 adrenergic agonists, which are devoid of respiratory depressant effects and addictive potential are being developed. Such drugs are useful analgesic agents when administered spinally. However, undesirable pharmacological properties of α-adrenergic agonists, specifically sedation and hypotension, limit the utility of these drugs when administered orally or by other peripheral routes. Thus, there is a need for effective analgesic agents that can be administered by oral or other peripheral routes and that lack undesirable side-effects such as sedation and hypotension. The present invention satisfies this need and provides related advantages as well. Also provided herein are new therapies for chronic pain sufferers, who, until now, have faced a lifetime of daily medication to control their pain. Unfortunately, available treatments for chronic neuropathic pain, such as tricyclic antidepressants, anti-seizure drugs and local anesthetic injections, only alleviate symptoms temporarily and to varying degrees. No available treatment reverses the sensitized pain state or cures pain such as neuropathic pain. Effective drugs that can be administered, for example, once or several times a month and that maintain analgesic activity for several weeks or months, are presently not available. Thus, there is a need for novel methods of providing long-term relief from chronic pain. The present invention satisfies this need and also provides related advantages. SUMMARY OF THE INVENTION Described herein are compounds for and methods of treating conditions or diseases in a subject by administering to the subject a pharmaceutical composition containing an effective amount of an α-adrenergic modulator. The compounds and methods are also useful for alleviating types of pain, both acute and chronic. Described herein is a method of treating a condition or disease alleviated by activation of α-adrenergic receptors in a mammal comprising: administering a compound having a structure wherein R 1 and R 2 are each independently selected from hydrogen, C 1-4 alkyl, C 1-4 alkoxy, OH, halogen, NR′ 2 , CN, CO 2 R′, C(O)NR′R″, alcohol, C 1-4 halogenated alkyl, C 1-4 halogenated alkoxy, and substituted or unsubstituted aryl or heteroaryl; R′ is selected from hydrogen, C 1-4 alkyl and C 1-4 halogenated alkyl, substituted or unsubstituted aryl or heteroaryl; R″ is selected from hydrogen and C 1-4 alkyl, substituted or unsubstituted aryl or heteroaryl; and wherein the compound activates at least one of the α adrenergic receptors. Also described herein is a composition for treating a condition or disease alleviated by activation of α-adrenergic receptors in a mammal comprising: a compound having a structure wherein R 1 and R 2 are each independently selected from hydrogen, C 1-4 alkyl, C 1-4 alkoxy, OH, halogen, NR′ 2 , CN, CO 2 R′, C(O)NR′R″, alcohol, C 1-4 halogenated alkyl, C 1-4 halogenated alkoxy, and substituted or unsubstituted aryl or heteroaryl; R′ is selected from hydrogen, C 1-4 alkyl and C 1-4 halogenated alkyl, substituted or unsubstituted aryl or heteroaryl; R″ is selected from hydrogen and C 1-4 alkyl, substituted or unsubstituted aryl or heteroaryl; and wherein the compound activates at least one of the α-adrenergic receptors. In one embodiment, the condition or disease is selected from the group consisting of hypertension, congestive heart failure, asthma, depression, glaucoma, elevated intraocular pressure, ischemic neuropathies, optic neuropathy, pain, visceral pain, corneal pain, headache pain, migraine, cancer pain, back pain, irritable bowel syndrome pain, muscle pain, pain associated with diabetic neuropathy, the treatment of diabetic retinopathy, other retinal degenerative conditions, stroke, cognitive deficits, neuropsychiatric conditions, drug dependence, drug addiction, withdrawal symptoms, obsessive compulsive disorder, obesity, insulin resistance, stress related conditions, diarrhea, diuresis, nasal congestions, spasticity, attention deficit disorder, psychoses, anxiety, autoimmune disease, Crohn's disease, gastritis, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and other neurodegenerative diseases. In one embodiment, the condition or disease is pain. In one embodiment, R 1 and R 2 are each independently a halogen or halogenated alkyl. In another embodiment, the compound is N-(2-chloro-3-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-difluoromethoxy)-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2,3-dimethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(trifluoromethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-fluoro-3-trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2,3-dimethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(3-bromo-2-methoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-chloro-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-methyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(3-chloro-2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2,3-dimethylbenzyl)-4,5-dihydro-1H-imidazol-2-amine. In another embodiment, the compound is N-(2-fluorobenzyl)-4,5-dihydro-1H-imidazol-2-amine. In one embodiment, the compound is selected from the group consisting of N-(2-chloro-3-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-difluoromethoxy)-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2,3-dimethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(trifluoromethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-fluoro-3-trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2,3-dimethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(3-bromo-2-methoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-chloro-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-methyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(3-chloro-2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2,3-dimethylbenzyl)-4,5-dihydro-1H-imidazol-2-amine, N-(2-fluorobenzyl)-4,5-dihydro-1H-imidazol-2-amine, and combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts the peripheral analgesic effects of a single oral dose of N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine in Chung model rats at 30 μg/kg, 100 μg/kg or 300 μg/kg. FIG. 2 depicts sedative effects (total activity counts) 30 minutes post intraperitoneal injection of 1 mg/kg and 10 mg/kg doses of N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine. DEFINITION OF TERMS Prodrug: A “prodrug” is a compound which is converted to a therapeutically active compound after administration. While not intending to limit the scope, conversion may occur by hydrolysis of an ester group or some other biologically labile group. Prodrug preparation is well known in the art. For example, “Prodrugs and Drug Delivery Systems,” which is a chapter in Richard B. Silverman, Organic Chemistry of Drug Design and Drug Action, 2d Ed., Elsevier Academic Press: Amsterdam, 2004, pp. 496-557, provides further detail on the subject. Halogen: As used herein, “halogen” is used to refer to a substituent found in column VIIA of the periodic table of elements, including fluorine, chlorine, bromine, and iodine. Tautomer: As used herein, “tautomer” refers to the migration of protons between adjacent single and double bonds. The tautomerization process is reversible. Compounds described herein can undergo the following tautomerization: DETAILED DESCRIPTION OF THE INVENTION Described herein are N-(2 and/or 3-substituted benzyl)-4,5-dihydro-1H-imidazol-2-amine compounds as subtype selective α 2A and/or α 2C adrenergic modulators having the general structure wherein R 1 and R 2 are each independently selected from hydrogen, C 1-4 alkyl, C 1-4 alkoxy, OH, halogen, NR′ 2 , CN, CO 2 R′, C(O)NR′R″, alcohol, C 1-4 halogenated alkyl, C 1-4 halogenated alkoxy, and substituted or unsubstituted aryl or heteroaryl; R′ is selected from hydrogen, C 1-4 alkyl and C 1-4 halogenated alkyl, substituted or unsubstituted aryl or heteroaryl; and R″ is selected from hydrogen and C 1-4 alkyl, substituted or unsubstituted aryl or heteroaryl. In one embodiment, wherein R 1 and R 2 are each independently selected from hydrogen, C 1-10 alkyl, C 1-10 alkoxy, OH, halogen, NR′ 2 , CN, CO 2 R′, C(O)NR′R″, alcohol, C 1-10 halogenated alkyl, C 1-10 halogenated alkoxy, and substituted or unsubstituted aryl or heteroaryl; R′ is selected from hydrogen, C 1-10 alkyl and C 1-10 halogenated alkyl, substituted or unsubstituted aryl or heteroaryl; and R″ is selected from hydrogen and C 1-10 alkyl, substituted or unsubstituted aryl or heteroaryl. R 1 and R 2 can each independently be a C 1-10 alkyl, which includes C 3-10 cycloalkyls and C 3-10 branched alkyls. R 1 and R 2 can each also independently be a substituted or unsubstituted aryl or heteroaryl which can include aromatic, heteroaromatic, or multi-heteroaromatic groups. The substituted or unsubstituted aryl or heteroaryl can be selected from phenyl, pyridinyl, thienyl, furyl, naphthyl, quinolinyl, indanyl or benzofuryl. Exemplary substituted or unsubstituted aryls or heteroaryls include, but are not limited to, benzenes, pyrideines, thiophenes, furans, naphthalenes, quinolines, indans and benzofurans. The aryl groups may be substituted with any common organic fictional group. Such aryl groups may be bonded to Formula 1 at any available position on the aryl group. An exemplary aryl group is a benzene (Formula 2): wherein at least one of R 4-9 must be Formula 1 and wherein the remaining R 4-9 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a pyridine as in Formula 3: wherein at least one of R 4-8 must be Formula 1 and wherein the remaining R 4-8 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a thiophene as in Formula 4: wherein at least one of R 4-7 must be Formula 1 and wherein the remaining R 4-7 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a furan as in Formula 5: wherein at least one of R 4-7 must be Formula 1 and wherein the remaining R 4-7 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a naphthalene as in Formula 6: wherein at least one of R 4-11 must be Formula 1 and wherein the remaining R 4-11 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a quinoline as in Formula 7: wherein at least one of R 4-10 must be Formula 1 and wherein the remaining R 4-10 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be an indan as in Formula 8: wherein at least one of R 4-13 must be Formula 1 and wherein the remaining R 4-13 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. Another aryl group may be a benzofuran as in Formula 9: wherein at least one of R 4-9 must be Formula 1 and wherein the remaining R 4-9 may be each independently substituted with a common organic functional group including, but not limited to, hydrogen, a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, thiol, or carboxy group subsitiuted with a C 1-10 alkyl, C 1-10 alkenyl, C 1-10 alkynl, aryl, halogen, hydroxyl, alkoxy, amino, cyano, nitro, or thiol group. α 2 adrenergic receptors have been characterized by molecular and pharmaceutical methods; the methods including α 1A , α 1B , α 1D , α 2A , α 2B and α 2C subtypes. Activation of these α-receptors can evoke physiological responses. Adrenergic modulators described herein activate one or both of the α 2B and/or α 2C receptors and have useful therapeutic actions. The following structures are contemplated according to the present description. The compounds described herein may be useful for the treatment of a wide range of conditions and diseases that are alleviated by α 2B and/or α 2C activation including, but not limited to, hypertension, congestive heart failure, asthma, depression, glaucoma, elevated intraocular pressure, ischemic neuropathies, optic neuropathy, pain, visceral pain, corneal pain, headache pain, migraine, cancer pain, back pain, irritable bowel syndrome pain, muscle pain, pain associated with diabetic neuropathy, the treatment of diabetic retinopathy, other retinal degenerative conditions, stroke, cognitive deficits, neuropsychiatric conditions, drug dependence, drug addiction, withdrawal symptoms, obsessive compulsive disorder, obesity, insulin resistance, stress related conditions, diarrhea, diuresis, nasal congestions, spasticity, attention deficit disorder, psychoses, anxiety, autoimmune disease, Crohn's disease, gastritis, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and other neurodegenerative diseases. Applicants have discovered that these compounds activate or modulate α 2B and α 2C receptors. Additionally, these compounds act as a highly effective analgesic, particularly in chronic pain models, with minimal undesirable side effects, such as sedation and cardiovascular depression, commonly seen with agonists of α 2B and α 2C receptors. Such compounds may be administered at pharmaceutically effective dosages. Such dosages are normally the minimum dose necessary to achieve the desired therapeutic effect; in the treatment of chromic pain, this amount would be roughly that necessary to reduce the discomfort caused by the pain to tolerable levels. Generally, such doses will be in the range 1-1000 mg/day; more preferably in the range 10 to 500 mg/day. However, the actual amount of the compound to be administered in any given case will be determined by a physician taking into account the relevant circumstances, such as the severity of the pain, the age and weight of the patient, the patient's general physical condition, the cause of the pain, and the route of administration. The compounds may be useful in the treatment of pain in a mammal, particularly a human being. Preferably, the patient will be given the compound orally in any acceptable form, such as a tablet, liquid, capsule, powder and the like. However, other routes may be desirable or necessary, particularly if the patient suffers from nausea. Such other routes may include, without limitation, transdermal, parenteral, subcutaneous, intranasal, intrathecal, intramuscular, intravenous, and intrarectal modes of delivery. Additionally, the formulations may be designed to delay release of the active compound over a given period of time, or to carefully control the amount of drug released at a given time during the course of therapy. Another embodiment is drawn to therapeutic compositions comprising the compounds of Formula 1, pharmaceutically acceptable derivatives, salts, prodrugs and/or combinations of these compounds and a pharmaceutically acceptable excipient. Such an excipient may be a carrier or a diluent; this is usually mixed with the active compound, or permitted to dilute or enclose the active compound. If a diluent, the carrier may be solid, semi-solid, or liquid material that acts as an excipient or vehicle for the active compound. The formulations may also include wetting agents, emulsifying agents, preserving agents, sweetening agents, and/or flavoring agents. If used as in an ophthalmic or infusion format, the formulation will usually contain one or more salt to influence the osmotic pressure of the formulation. Another embodiment is directed to methods for the treatment of pain, particularly chronic pain, through the administration of a compound of Formula 1, and pharmaceutically acceptable salts, and derivatives thereof to a mammal in need thereof. As indicated above, the compound will usually be formulated in a form consistent with the desired mode of delivery. Some embodiments provide methods that rely on administration of one or more pharmaceutical compositions to a subject. As used herein, the term “subject” means any animal capable of experiencing pain, for example, a human or other mammal such as a primate, horse, cow, dog or cat. The methods described herein are used to treat both acute and chronic pain, and, as non-limiting examples, pain which is neuropathic, visceral or inflammatory in origin. In particular embodiments, the methods of the invention are used to treat neuropathic pain; visceral pain; post-operative pain; pain resulting from cancer or cancer treatment; and inflammatory pain. Both acute and chronic pain can be treated by the methods described herein, and the term “pain” encompasses both acute and chronic pain. As used herein, the term “acute pain” means immediate, generally high threshold, pain brought about by injury such as a cut, crush, burn, or by chemical stimulation such as that experienced upon exposure to capsaicin, the active ingredient in chili peppers. The term “chronic pain,” as used herein, means pain other than acute pain and includes, without limitation, neuropathic pain, visceral pain, inflammatory pain, headache pain, muscle pain and referred pain. It is understood that chronic pain is of relatively long duration, for example, several years and can be continuous or intermittent. Unless otherwise indicated, reference to a compound should be construed broadly to include compounds, pharmaceutically acceptable salts, prodrugs, tautomers, alternate solid forms, non-covalent complexes, and combinations thereof, of a chemical entity of a depicted structure or chemical name. A pharmaceutically acceptable salt is any salt of the parent compound that is suitable for administration to an animal or human. A pharmaceutically acceptable salt also refers to any salt which may form in vivo as a result of administration of an acid, another salt, or a prodrug which is converted into an acid or salt. A salt comprises one or more ionic forms of the compound, such as a conjugate acid or base, associated with one or more corresponding counter-ions. Salts can form from or incorporate one or more deprotonated acidic groups (e.g. carboxylic acid/carboxylate), one or more protonated basic groups (e.g. amine/ammonium), or both (e.g. zwitterions). A prodrug is a compound which is converted to a therapeutically active compound after administration. For example, conversion may occur by hydrolysis of an ester group or some other biologically labile group. Prodrug preparation is well known in the art. For example, “Prodrugs and Drug Delivery Systems,” which is a chapter in Richard B. Silverman, Organic Chemistry of Drug Design and Drug Action, 2d Ed., Elsevier Academic Press: Amsterdam, 2004, pp. 496-557, provides further detail on the subject. Tautomers are isomers that are in rapid equilibrium with one another. For example, tautomers may be related by transfer of a proton, hydrogen atom, or hydride ion. Not intended to be limited by the above described compounds, various tautomers of the above compounds may be possible. For example, not intended as a limitation, tautomers are possible between the 4,5-dihydrooxazole and the adjacent nitrogen as shown below. Other tautomers are possible when the compound includes, for example but not limited to, enol, keto, lactamin, amide, imidic acid, amine, and imine groups. Tautomers will generally reach an equilibrium state wherein the double bond is resonantly shared between the two bond lengths. Unless stereochemistry is explicitly and unambiguously depicted, a structure is intended to include every possible stereoisomer, both pure or in any possible mixture. Alternate solid forms are different solid forms than those that may result from practicing the procedures described herein. For example, alternate solid forms may be polymorphs, different kinds of amorphous solid forms, glasses, and the like. Non-covalent complexes are complexes that may form between the compound and one or more additional chemical species that do not involve a covalent bonding interaction between the compound and the additional chemical species. They may or may not have a specific ratio between the compound and the additional chemical species. Examples might include solvates, hydrates, charge transfer complexes, and the like. The following examples provide synthesis methods for forming compounds described herein. One skilled in the art will appreciate that these examples can enable a skilled artisan to synthesize the compounds described herein. EXAMPLE 1 Generic Reaction 1 In scheme A above, Formula 11 was either commercially available or synthesized by different reductive amination methods from Formula 10. One of those methods was published by David J. H. et al (J. Org. Chem. 48: 289-294 (1983)). The key step was the coupling for Formula 11 with imidazoline which had an appropriate leaving group on the second position to give Formula 12. The leaving group may be methylthiol (R═(O)COMe) or sulfuric acid (R═H). There are also other known coupling procedures known by those skilled in the art or by modifications of known procedures known by those skilled in the art. In Scheme B, another method is depicted to synthesize Formula 11 from substituted benzoic acid, substituted ester or substituted benzyl alcohol, all of which are commercially available. Formula 13 was converted to an ester which can be reduced to Formula 14 with lithium aluminum hydride (LAH) or borane as reagents. Conversion of the alcohol, Formula 14, to the azide, Formula 15, may be accomplished by methods such as Mitsunobu reaction with diphenylphosphoryl azide in one step, or converting alcohol to a good leaving group which can be replaced with azide anion. Denitrogenation of azide to amine was carried out with a phosphine such as triphenyl phosphine. Subsequent basic hydrolysis liberated the intermediate to amine. The compounds described herein may also be synthesized by other methods known by those skilled in the art. EXAMPLE 2 Synthesis of N-(2-chloro-3-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine To a 7.08 mmol solution of 2-chloro-3-fluorobenzaldehyde 1 (1.00 g, commercially available from 3B Medical Systems, Inc.) in 8.0 mL of tetrahydrofuran (THF) was added 8.50 mL of 1.0M lithium bis(trimethylsilyl)-amide via syringe at 0° C. The resulting solution was stirred at 0° C. for 3 hours. 8.50 mL of 1.0M LAH was added via syringe. Three hours later, the reaction mixture was carefully poured onto crushed ice. Ammonium chloride (aq) and Rochelle's salt (aq) were added to this mixture. The aqueous layer was extracted three times with 200 mL of chloroform/isopropanol (3:1). The pooled organic layer was dried over magnesium sulfate. The mixture was filtered, and the solvents were removed under vacuum to give (2-cholor-3-fluorophenyl)methanamine 2. The weight of the product was 0.92 g. A mixture of 0.92 g of (2-cholor-3-fluorophenyl)methanamine 2 and 0.790 g of 4,5-dihydro-1H-imidazole-2-sulfonic acid (commercially available from Astatech) in 10.0 mL of ethanol was heated in a sealed tube to 90° C. for 16 hours. Then, the reaction mixture was cooled to room temperature. Next, the ethanol was removed under vacuum. The remaining residue was basified with aqueous sodium bicarbonate solution and the pH was adjusted to about 10 with 2M sodium hydroxide. The aqueous layer was extracted three times with 100 mL of chloroform/isopropanol (3:1). The pooled organic layer was dried over magnesium sulfate and the mixture was then filtered. Amino-modified silica gel was added to the filtrate and the solvents were removed under vacuum. Purification by chromatorography on amino-modified silica gel (3.5% methanol in dichloromethane afforded 0.575 g of N-(2-chloro-3-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine 3 as a yellow solid. 1 H NMR (300 MHz, CD 3 OD): δ 7.32-7.21 (m, 2H), 7.15-7.09 (m, 1H), 4.42 (s, 2H), 3.48 (s, 4H). The following compounds can also be prepared according to Example 2. N-(2-difluoromethoxy)-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.43-7.32 (m, 2H), 7.24-7.16 (m, 2H), 6.90 (t, J=73.8 Hz, 1H), 4.43 (s, 2H), 3.62 (s, 4H). N-(2,3-dimethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.11-7.04 (m, 3H), 4.33 (s, 2H), 3.56 (s, 4H). N-(trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.76-7.65 (m, 2H), 7.58-7.50 (m, 2H), 4.61 (s, 2H), 3,74 (s, 4H). N-(trifluoromethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.51-7.48 (m, 1H), 7.39-7.28 (m, 3H), 4.45 (s, 2H), 3.60 (s, 4H). N-(2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.40 (t, J=7.5 Hz, 1H), 7.28 (q, J=7.2 Hz, 1H), 7.11-7.03 (m, 2H), 4.41 (s, 2H), 3.56 (s, 4H). N-(2-fluoro-3-trifluoromethyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.66 (t, J=7.5 Hz, 1H), 7.57 (q, J=7.5 Hz, 1H), 7.30 (t, J=7.5 Hz, 1H), 4.42 (s, 2H), 3.50 (s, 4H). N-(2,3-dimethoxy-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.05-6.87 (m, 3H), 4.34 (s, 2H), 3.83 (s, 6H), 3.55 (s, 4H). EXAMPLE 3 Synthesis of N-(3-bromo-2-methoxy-benzvl)-4,5-dihydro-1H-imidazol-2-amine 5.0 mL of sulfuric acid (H 2 SO 4 ) was slowly added to a solution of 5.0 g of 3-bromo-2-methoxy-benzoic acid 4 in 100 mL of methanol (MeOH). The resulting solution was heated to reflux overnight. The solution was cooled to room temperature and quenched with sodium bicarbonate to pH 7. The aqueous layer was extracted several times with ethyl acetate. The combined organic extracts were washed with brine and dried over sodium sulphate. The resulting mixture was filtered. The solvents were evaporated under reduced pressure to afford 5.3 g of 3-bromo-2-methoxy-benzoic acid methyl ester 5. 2.4 g of lithium borohydride (LiBH 4 ) was added to a solution of 5.3 g of 3-bromo-2-methoxy-benzoic acid methyl ester 5 in 200 mL of ether (Et 2 O) at 0° C. After stirring for 5 minutes, 5 mL of methanol was added. The reaction mixture was warmed to room temperature and kept there for 2.5 hours. Thereafter, 2.4 g more of lithium borohydride was added. The reaction mixture was quenched with aluminum chloride. After standard aqueous work up, and silica gel column purification (hexane/ethyl acetate 2:1), 4.0 g of 3-bromo-2-methoxy-phenyl-methanol 6 was obtained. 6.00 g of diphenyl phosphorazidate and 4.1 g of 1,8-diazabicyclo[5.4.0]undec-7-ene were added to 4.0 g of 3-bromo-2-methoxy-phenyl-methanol 6 in 100 mL of toluene at 0° C. The mixture was stirred at room temperature overnight. The reaction mixture was quenched with aqueous ammonium chloride. The aqueous layer was extracted with ethyl acetate/THF. The pooled organic extracts were washed with brine and dried over magnesium sulfate. The mixture was filtered. The solvents were removed under vacuum. The residue was purified by chromatography on silica gel to give 1-azidomethyl-3-bromo-2-methoxy-benzene 7. 1.1 g of potassium hydroxide (KOH) and 5.8 g of triphenyl phophine (Ph 3 P) were added to a solution of 1-azidomethyl-3-bromo-2-methoxy-benzene 7 in 100 mL of THF and 10 mL of water. The mixture was stirred overnight at room temperature. The mixture was quenched with aqueous concentrated hydrochloride. After standard acid/base aqueous work up, 3.9 g of crude 3-bromo-2-methoxy-benzylamine 8 was obtained (after two steps). 10 mL of acetic acid (HOAc) was added to a solution of 3.9 g of 3-bromo-2-methoxy-benzylamine 8 and 3.1 g of methyl 2-(methylthio)-4,5-hihydro-1H-imidazole-1-carboxylate in 100 mL of methanol. The resulting solution was heated to a gentle reflux and refluxed overnight. The solution was cooled to room temperature, quenched with sodium hydroxide and extracted with ethyl acetate. The combined organic extracts were washed with brine and dried over magnesium sulfate. The mixture was then filtered. The solvents were removed under vacuum. The remaining residue was purified by chromatography on silica gel (10% saturated ammonia methanol in dichloromethane) to give (3-bromo-2-methoxy-benzyl-4,5-dihydro-1H-imidazol-2-yl)-amine 9. 1 H NMR (300 MHz, CD 3 OD): δ=7.51 (d, J=3 Hz, 1H), 7.25-7.29 (m, 1H), 6.80 (d, J=9 Hz, 1H), 4.46 (s, 2H), 3.84 (s, 4H), 3.63 (s, 3H). The following compounds can also be prepared according to Example 3. N-(2-chloro-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.51-7.53 (m, 1H), 7.28-7.29 (m, 1H), 7.14-7.21 (m, 2H), 4.59 (s, 2H), 3.58 (s, 4H). N-(2-methyl-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.08-7.12 (m, 4H), 4.45(d, J=6Hz, 2H), 3.54 (s, 4H), 2.28 (s, 3H). N-(3-chloro-2-fluoro-benzyl)-4,5-dihydro-1H-imidazol-2-amine: 1 H NMR (300 MHz, CD 3 OD): δ=7.40-7.31 (m, 2H), 7.16-67.10 (m, 1H), 4.42 (s, 2H), 3.56 (s, 4H). EXAMPLE 4 Synthesis of N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine A mixture of 5.32 g of (2,3-dichlorophenyl)methanamine 10 and 4.56 g of 4,5-hihydro-1H-imidazole-2-sulfonic acid are mixed in 40.0 mL ethanol (EtOH) and heated in a sealed tube at 90° C. for 16 hours. Then, the reaction mixture was cooled to room temperature. Next, the ethanol was removed under vacuum. The remaining residue was basified with aqueous sodium bicarbonate solution and the pH was adjusted to about 10 with 2M sodium hydroxide. The aqueous layer was extracted three times with 400 mL of chloroform/isopropanol (3:1). The pooled organic layer was dried over magnesium sulfate and the mixture was then filtered. The filtrate was added to amino-modified silica gel (4-5% methanol in dichloromethane) and afforded 3.99 g of Compound 11 as a yellow solid. 1 H NMR (300 MHz, CD 3 OD): δ 7.43 (dd, J=7.8, 1.8 Hz, 1H, 7.37-7.33 m, 1H), 7.26 (t, J=7.8 Hz, 1H), 4.43 (s, 2H), 3.51 (s, 4H) EXAMPLE 5 Biological Intrinsic Activity Data Certain compounds described herein were tested for α-adrenergic activity using the Receptor Selection and Amplification Technology (RSAT) assay (Messier et al., 1995, Pharmacol. Toxicol. 76, pp. 308-311). Cells expressing each of the c 2 adrenergic receptors alone were incubated with the various compounds and a receptor-mediated growth response was measured. The compound's activity is expressed as its relative efficacy compared to standard full agonist (see Table 1 below). The compounds described herein activate α 2B and/or α 2C receptors. Compound α 1A α 2B α 2C 587 (1.01) 33 (1.11) 484 (0.60) 345 (1.12) 50 (0.81) 471 (0.86) 430 (0.79) 56 (0.92) 1594 (0.63) nd 499 (0.73) nd 282 (1.10) 14.0 (0.94) 46.8 (0.48) nd = not determined EXAMPLE 6 Biological Intrinsic Activity Data Various concentrations of N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine were administered orally to Chung model rats. A model in accordance with Kim and Chung 1992, Pain 150, pp 355-363 (Chung model), for chronic pain (in particular peripheral neuropathy) involves the surgical ligation of the L5 (and optionally the L6) spinal nerves on one side in experimental animals. Rats recovering from the surgery gain weight and display a level of general activity similar to that of normal rats. However, these rats develop abnormalities of the foot, wherein the hindpaw is moderately everted and the toes are held together. More importantly, the hindpaw on the side affected by the surgery appears to become sensitive to pain from low-threshold mechanical stimuli, such as that producing a faint sensation of touch in a human, within about 1 week following surgery. This sensitivity to normally non-painful touch is called “tactile allodynia” and lasts for at least two months. The response includes lifting the affected hindpaw to escape from the stimulus, licking the paw and holding it in the air for many seconds. None of these responses is normally seen in the control group. Rats are anesthetized before surgery. The surgical site is shaved and prepared either with betadine or Novacaine. Incision is made from the thoracic vertebra XIII down toward the sacrum. Muscle tissue is separated from the spinal vertebra (left side) at the L4-S2 levels. The L6 vertebra is located and the transverse process is carefully removed with a small rongeur to expose the L4-L6 spinal nerves. The L5 and L6 spinal nerves are isolated and tightly ligated with 6-0 silk thread. The same procedure is done on the right side as a control, except no ligation of the spinal nerves is performed. A complete hemostasis is confirmed, then the wounds are sutured. A small amount of antibiotic ointment is applied to the incised area, and the rat is transferred to the recovery plastic cage under a regulated heat-temperature lamp. On the day of the experiment, at least seven days after the surgery, typically six rats per test group are administered the test drugs by intraperitoneal (i.p.) injection or oral gavage. For i.p. injection, the compounds are formulated in d H 2 O and given in a volume of 1 ml/kg body weight using an 18-gauge, 3 inch gavage needle that is slowly inserted through the esophagus into the stomach. Tactile allodynia is measured prior to and 30 minutes after drug administration using von Frey hairs that are a series of fine hairs with incremental differences in stiffness. Rats are placed in a plastic cage with a wire mesh bottom and allowed to acclimate for approximately 30 minutes. The von Frey hairs are applied perpendicularly through the mesh to the mid-plantar region of the rats' hindpaw with sufficient force to cause slight buckling and held for 6-8 seconds. The applied force has been calculated to range from 0.41 to 15.1 grams. If the paw is sharply withdrawn, it is considered a positive response. A normal animal will not respond to stimuli in this range, but a surgically ligated paw will be withdrawn in response to a 1-2 gram hair. The 50% paw withdrawal threshold is determined using the method of Dixon, W. J., Ann. Rev. Pharmacol. Toxicol. 20:441-462 (1980) hereby incorporated by reference. The post-drug threshold is compared to the pre-drug threshold and the percent reversal of tactile sensitivity is calculated based on a normal threshold of 15.1 grams. Table 2 below shows the peak allodynia reversal at 30 μg/kg, 100 μg/kg or 300 μg/kg doses. TABLE 2 Peak Allodynia Reversal Dose (Oral, 30 min.) 300 μg/kg 84% +/− 7.5% 100 μg/kg  68% +/− 12.7%  30 μg/kg 28% +/− 9.5% As shown in Table 2, 30 μg/kg oral dosage resulted in 28% allodynia reversal. The analgesic effect was seen quickly, in about 30 minutes. FIG. 1 shows a peak percent allodynia reversal at 30 minutes followed by a steady decrease to baseline at about 120 minutes. EXAMPLE 7 In Vivo Activity Data Data was acquired from wild type rats administered N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine intraperitoneally (IP). Rats were split into groups of six and administered 1 mg/kg or 10 mg/kg doses of N-(2,3-dichlorobenzyl)-4,5-dihydro-1H-imidazol-2-amine to assess the sedative effects of the administration of the agent. As can be seen in both FIG. 2 and Table 3, 10 mg/kg had a significant sedative effect on the dosed rats. TABLE 3 Dose Sedative Effect (IP)  1 mg/kg No significant effect 10 mg/kg 23% sedating Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, 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 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 at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 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. The terms “a,” “an,” “the” and similar referents used 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. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual 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 otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims. Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than 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. Furthermore, numerous references have been made to patents and printed publications throughout this specification. Each of the above-cited references and printed publications are individually incorporated herein by reference in their entirety. In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.

Described herein are compounds for and methods of treating conditions or diseases in a subject by administering to the subject a pharmaceutical composition containing an effective amount of an α-adrenergic modulator. The compounds and methods are also useful for alleviating types of pain, both acute and chronic.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to a honing apparatus for honing internal or external cylindrical surfaces of a workpiece, and more particularly to a technique for improving the honing accuracy. 2. Discussion of the Prior Art A honing apparatus or machine for finishing internal or external cylindrical surfaces of a workpiece to a relatively high degree of accuracy and smoothness generally includes (a) a honing head which supports abrasive honing stones or sticks such that the honing stones are opposed to the cylindrical surface of the workpiece and are movable substantially in a radial direction of the cylindrical surface, (b) a changing mechanism associated with the honing head, for changing either the radial position of the honing stones or the pressure of contact between the honing stones and the cylindrical surface, (c) a first drive device for effecting a relative reciprocating movement between the honing head and the workpiece, and (d) a second drive device for effecting a relative rotating movement between the honing head and the workpiece. In the honing apparatus of the type indicated above, the honing stones are given by the first and second drive devices concurrent movements in both circumferential and axial directions of the cylindrical surface of the workpiece while the stones are held in contact with the cylindrical surface. At the same time, the honing stones are given by the changing mechanism a feed movement in the radial direction of the cylindrical surface, or a contact pressure against the cylindrical surface. It is recognized that the cylindricity, roundness, smoothness and other accuracy values of the honed surface are greatly influenced by the honing conditions such as the axial reciprocating range and speed of the honing stones relative to the workpiece, the rotating speed of the honing stones relative to the workpiece, and the radial feed rate of the stones or contact pressure of the stones against the workpiece surface. To hone the workpiece surface to sufficiently high degrees of accuracy and smoothness with high honing efficiency, the first and second drive devices and the changing mechanism should be accurately controlled with an excellent level of operating response. Laid-open Publication No. 59-93859 of unexamined Japanese Utility Model Application discloses a honing apparatus which uses electrically operated motors as drive sources of the second drive device and the changing mechanism as indicated above. However, the publication is silent about the type of the drive source of the first drive device for reciprocating movement between the honing head and the workpiece. However, the known arrangements usually employ a hydraulically operated actuator as the drive source of the first drive device. To improve the honing accuracy and honing efficiency, the first drive device should be precisely controlled to control the relative axial reciprocating movement of the honing stones in response to the actual conditions of the workpiece surface in the process of being honed. However, the hydraulically operated actuator conventionally used for the first drive device is difficult to control for regulating the range and speed of the relative reciprocating movement between the honing stones and the workpiece, with a short response to the varying conditions of the workpiece surface. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a honing apparatus wherein the range and speed of relative reciprocating movement between the honing head and the workpiece may be accurately controlled according to the actual conditions of the honed surface. The above object may be attained according to the principle of the present invention, which provides a honing apparatus for honing a cylindrical surface of a workpiece, comprising: a honing head supporting honing stones such that the honing stones are opposed to the cylindrical surface of the workpiece; a first drive device including an electrically operated bidirectional actuator for effecting a relative reciprocating movement between the honing head and the workpiece in an axial direction of the cylindrical surface; a second drive device for effecting a relative rotating movement between the honing head and the workpiece; a diameter measuring device for measuring a diameter of the cylindrical surface of the workpiece; and a reciprocation control device connected to the diameter measuring device and the electrically operated actuator, and operating based on a measurement of the diameter by the diameter measuring device, to determine at least one of a range of the relative reciprocating movement, and a speed distribution of the relative reciprocating movement over a range of the relative reciprocating movement. The reciprocation control device controls the electrically operated bidirectional actuator based on the determined range and/or speed distribution of the relative reciprocating movement. In the honing apparatus of the present invention constructed as described above, the relative reciprocating movement between the honing head and the workpiece is given by the electrically operated bidirectional actuator of the first drive device. The diameter measuring device measures the diameter of the cylindrical surface of the workpiece, and supplies the reciprocation control device with the measured diameter of the cylindrical surface. Based on the measured diameter value of the cylindrical surface, the reciprocation control device determines at least one of the range of the relative reciprocating movement and the speed distribution of the reciprocating movement, and commands the electrically operated bidirectional actuator according to the determined movement range and/or speed distribution. More specifically, the operating range of the actuator is suitably changed if it is necessary to adjust the range of the axial reciprocating movement between the honing stones and the workpiece surface. If it is necessary to adjust the speed distribution of the reciprocating movement over its predetermined or controlled range, the operating speed of the actuator is suitably controlled. Thus, the instant honing apparatus is adapted to automatically control the relative reciprocating movement of the honing stones and the workpiece, based on the currently measured diameter of the cylindrical surface of the workpiece, so that the accuracy and smoothness of the honed cylindrical surface are improved, with high honing efficiency or minimum honing time. Moreover, the electrically operated bidirectional actuator of the first drive device assures accurate and quick changes of the relative reciprocating range and speed of the honing stones, which are not available by the conventionally used hydraulically operated actuator. In one form of the present invention, the reciprocation control device controls the electrically operated actuator such that the range of the relative reciprocating movement is changed by an amount proportional to a difference between two values of the diameter of the cylindrical surface of the workpiece as measured at an axial end and an axially middle portion of the cylindrical surface. In another form of the invention, the reciprocation control device controls the electrically operated actuator to control the speed distribution of the relative reciprocating movement such that a time duration during which the honing stones are kept in contact with an axial end portion of the cylindrical surface of the workpiece is changed by an amount proportional to a difference between two values of the diameter of the cylindrical surface as measured at an axial end and an axially middle portion of the cylindrical surface. In a further form of the invention, the diameter measuring device is adapted to measure the diameter of the cylindrical surface of the workpiece while the honing head is moved in one direction from one axial end of the cylindrical surface toward the other axial end, and determines an amount of change of the above-indicated range and/or speed distribution of the relative reciprocating movement while the honing head is moved in a direction opposite to the above-indicated one direction. In a still further form of the invention, the honing head comprises guides provided thereon so as to extend in the axial direction for guiding the honing head, and the diameter measuring device comprises an air micrometer device including at least one nozzle which is formed through one of the guides such that each nozzle is open toward the cylindrical surface of the workpiece. In this case, the diameter measuring device may further comprise: a pressure-voltage converter supported so as to rotate with the honing head and operable to convert a back pressure of the at least one nozzle of the air micrometer device into a voltage signal; a voltage-frequency converter supported so as to rotate with the honing head and connected to the pressure-voltage converter for converting the voltage signal into a frequency signal; a rotating coil supported so as to rotate with the honing head and connected to the voltage-frequency converter; and a stationary coil disposed stationary adjacent to the rotating coil and generating a voltage corresponding to an amount of change in a magnitude of a magnetic field produced by the rotating coil. In a yet further form of the invention, the first drive device comprises: a spindle connected to the honing head; a spindle mover supported so as to move with the spindle in the axial direction, the spindle mover supporting the spindle such that the spindle and the spindle mover are rotatable relative to each other and immovable relative to each other in an axial direction of the spindle; a feedscrew disposed parallel to the spindle and immovably relative to the spindle in the axial direction, and rotated by the electrically operated bidirectional actuator; and a nut engaging the feedscrew and fixed to the spindle mover. In this case, the honing apparatus may further comprise: a changing mechanism associated with the honing head, for changing one of a radial position of the honing stones in a radial direction of the cylindrical surface of the workpiece, and a pressure of contact between the honing stones and the cylindrical surface; a rod axially movably received in an axial bore formed in the spindle; a rod mover supported so as to move with the rod in the axial direction, the rod mover supporting the rod such that the rod and the rod mover are rotatable relative to each other and immovable relative to each other in an axial direction of the rod; another feedscrew disposed parallel to the rod and supported by the spindle mover rotatably and immovably relative to the spindle mover in an axial direction of the above-indicated another feedscrew; another nut engaging the feedscrew and fixed to the rod mover; a non circular shaft extending coaxially from one end of the above-indicated another feedscrew and having a non-circular transverse cross sectional shape; and a rotating member supported immovably in an axial direction of the non-circular shaft and engaging the non-circular shaft rotatably with the non-circular shaft and movably relative to the non-circular shaft, the rotating member being rotated by an electrically operated bidirectional actuator of the changing mechanism. In yet another form of the invention, the honing apparatus further comprise a changing mechanism associated with the honing head, for changing one of a radial position of the honing stones in a radial direction of the cylindrical surface of the workpiece, and a pressure of contact between the honing stones and the cylindrical surface, the changing mechanism including an electrically operated bidirectional actuator; a resistance measuring device for measuring a honing resistance between the honing stones and the cylindrical surface of the workpiece; and a honing control device connected to the resistance measuring device and the electrically operated bidirectional actuator of the changing mechanism. The honing control device operates based on the honing resistance measured by the resistance measuring device, to determine the radial position of the honing stones in the radial direction or the pressure of contact between the honing stones and the cylindrical surface of the workpiece. The honing control device is adapted to control the electrically operated bidirectional actuator of the changing mechanism based on the determined radial position or the pressure of contact. In the above form of the invention, the changing mechanism is also driven by the electrically operated bidirectional actuator (which will be referred to as the second electrically operated actuator, as distinguished from the actuator of the first drive device). The resistance measuring device measures the honing resistance and supplies the honing control device with the measured honing resistance. Based on the measured honing resistance, the honing control device controls the second electrically operated actuator in order to adjust the radial position of the honing stones relative to the cylindrical surface of the workpiece, in the case where the stock removal of the workpiece is effected by a feed movement of the honing stones in the radial direction of the cylindrical surafce. In this case, the honing control device may be adapted to determine whether the honing resistance measured by the resistance measuring device is larger than a predetermined upper limit or smaller than a predetermined lower limit, and if the measured honing resistance is larger than the upper limit or smaller than the lower limit. The honing control device further determines a difference between the measured honing resistance and the upper or lower limit. The honing control device then controls the second electrically operated bidirectional actuator of the changing mechanism such that a rate of change in the radial position of the honing stones is changed by an amount proportional to the difference. In the case where the stock removal of the workpiece is achieved by maintaining a predetermined pressure of contact between the honing stones and the workpiece surface, the honing control device controls the second electrically operated actuator to adjust the contact pressure based on the honing resistance measured by the resistance measuring device. In either of the two cases described above, the radial feed rate of the honing head or stones or the contact pressure of the honing stones against the workpiece surface is automatically adjusted based on the actually measured honing resistance, so that otherwise possible loading or abnormal wear or breakage of the honing stones may be avoided, and the honing time may be further reduced. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be better understood by reading the following detailed description of a presently preferred embodiment of the invention, when considered in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic front elevational view in cross section of one embodiment of the present invention in the form of a single-spindle vertical honing machine for honing an internal cylindrical surface of a workpiece; FIG. 2 is a transverse cross sectional view of a honing head of the honing machine of FIG. 1; FIG. 3 is an elevational view in cross section take along line III--III of FIG. 2; FIG. 4 is a block diagram showing an electric control system of the honing machine; FIG. 5 and FIG. 7 are views illustrating an operation to control the range of reciprocating movement of the honing head of the honing machine; FIG. 6 and FIG. 8 are front elevational views in cross section of the internal, cylindrical surface of the workpiece, corresponding to the operations of FIGS. 5 and 7, respectively; FIG. 9 is a view illustrating an operation to control the speed of reciprocation of the honing head; FIG. 10 is a graph illustrating a honing speed controlled in the instant embodiment, in relation to the spindle torque and an amount of stock removal from the workpiece; and FIG. 11 is a view illustrating a reciprocating movement of a honing head of a known internal honing machine, which is effected by a hydraulically operated actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, reference numeral 10 denotes a honing head which has a vertical posture with its axis (hereinafter referred to as "head axis") extending in the vertical direction. The honing head 10 includes a cylindrical tool body 12 extending in the head axis. As shown in the transverse cross sectional view of FIG. 2, the tool body 12 carries six generally U-shaped shoes 14 which extend from the head axis in the radial direction such that the shoes 14 are evenly spaced apart from each other in the circumferential direction of the tool body 12. These shoes 14 are slidably movable in the radial direction of the tool body 12. To the outer surfaces of the shoes 14, there are attached respective grinding stones (abrasive sticks) 16 as honing tools. The inner ends of the shoes 14 are positioned within a bore 18 formed through the tool body 12. The inner end faces of the shoes 14 are inclined, and these inclined inner end faces are held in engagement with complemental coned surfaces of two conical members 24, 24, which are received within the bore 18 slidably in the direction of the head axis. With the conical members 24 lowered in the bore 18, the shoes 14 are concurrently moved from the original position of FIG. 1 in the radially outward direction. The shoes 14 are moved toward the original position in the radially inward direction under a biasing action of a suitable spring (not shown) associated with the shoes 14 and the tool body 12, when the conical members 24 are lifted. As shown in FIG. 2, the tool body 12 further has six cemented carbide metal guides 26 fixed thereon adjacent to the shoes 14 such that the guides 26 extend in the direction of the head axis. The guides 26 are evenly spaced apart from each other in the circumferential direction of the tool body 12. As is apparent from the cross sectional view of FIG. 3 taken along line III--III of FIG. 2, each guide 26 has an outer guide surface 28, which forms a part of a cylindrical surface whose axis is parallel to the head axis. Of the six guides 26, a pair of the guides which are opposed to each other diametrically of the tool body 12 have small-diameter air nozzles 32 formed therethrough in the radial direction, in fluid communication with respective air passages 30 formed in the tool body 12. The air nozzles 32 are open in the guide surfaces 28 of the above-indicated pair of guides 26. The two air nozzles 32 are aligned with each other in the direction of the head axis. The functions of the guides 26, air passages 30 and air nozzles 32 will be described later. The tool body 12 is connected at its upper end to a first spindle 40 and a second spindle 42, via universal couplings 44, as shown in FIG. 1. The first spindle 40 accommodates a pressure-voltage converter 46, and a voltage-frequency converter 48. The functions of these converters 46, 48 will also be described later. A spline shaft 50 extends coaxially from the upper end of the second spindle 42. On this spline shaft 50, there is axially slidably fitted a boss of a driven pulley 52, which is connected to a drive pulley 60 via a belt 61. The drive pulley 60 is connected to an output shaft 56 of a spindle motor 54 via a torque sensor 58. Namely, the first spindle 40, second spindle 42 and honing head 10 are rotated by the spindle motor 54. The torque sensor 58 detects a spindle torque about the axis of the honing head 10, which is almost proportional to a honing resistance between the honing stones 16 and a cylindrical surface of a cylinder bore 64 formed in a workpiece in the form of a cylinder block 62. The spindle motor 54 and the torque sensor 58 are secured to a frame 68 of the honing machine. The second spindle 42 is formed with a radially outward flange 70 at its upper end portion. The flange 70 engages a spindle mover 74 via two thrust bearings 72. The spindle mover 74 supports the second spindle 42 such that the second spindle 42 is rotatable relative to the spindle mover 74 and is moved with the spindle mover 74. The spindle mover 74 has a nut 75 fixed thereto. The nut 75 engages a feedscrew in the form of a ballscrew 76 which is disposed parallel to the second spindle 42. With the ballscrew 76 rotated in opposite directions, the spindle mover 74 is reciprocated in the direction of the head axis. The ballscrew 76 is connected to an output shaft 84 of a first servomotor 78 via a belt 80. Described more specifically, an operation of the first servomotor 78 in one direction will cause the spindle mover 74 to be moved in the upward direction, whereby the first and second spindles 40, 42 and the honing head 10 are lifted by a distance equal to the distance of upward movement of the spindle mover 74. Similarly, an operation of the servomotor 78 in the opposite direction will cause the spindle mover 74 to be moved in the downward direction, whereby the honing head 10 is lowered by a distance equal to the distance of downward movement of the spindle mover 74. The ballscrew 76 is rotatably supported by a support member 82 such that the ballscrew 76 is immovable in its axial direction. The support member 82 and the first servomotor 78 are both secured to a frame 83 of the machine. The first servomotor 78 is provided with a first encoder 86 which generates a pulse signal representative of a rotating angle of the output shaft 84. The second spindle 42 has an axial bore 90 formed therein so as to extend from an upper portion thereof a short distance below the flange 70, down to its lower end. In this axial bore 90, there is axially slidably inserted a rod 92, which extends from the lower end of the second spindle 42, through an axial bore 94 formed through the first spindle 40, into the bore 18 in the tool body 12. The rod 92 is connected at its lower end to the conical members 24 described above. It will be understood that this rod 92 is provided to move the honing stones 16 in the radially outward and inward directions. The universal coupling 44 described above has a central bore through which the rod 92 passes. Since the universal coupling 44 is adapted to be pivotable through a relatively small angle, the rod 92 does not disturb a flexible coupling movement of the universal coupling 44. A pin 96 penetrates the upper end portions of the rod 92 and second spindle 42. The pin 96 engages the rod 92 such that these two members 96, 92 are rotated together and moved together in the axial direction of the rod 96. The second spindle 42 has a pair of elongate holes 98 formed in the axial direction. With the pin 96 extending through the elongate holes 98, the rod 92 and the pin 96 are movable over a limited distance in the axial direction of the rod 92. The opposite end portions of the pin 96 which extend outwardly from the outer circumferential surface of the second spindle 42 are held in engagement with a rod mover 104 through two thrust bearings 102, such that the rod 92 and the second spindle 42 are rotatable relative to the rod mover 104, and such that the rod 92 is moved in the axial direction with the rod mover 104. The rod mover 104 has a nut 105 fixed thereto. The nut 105 engages a ballscrew 106 which is disposed parallel to the second spindle 42. The ballscrew 106 is supported rotatably by the spindle mover 74. A spline shaft 108 extends coaxially from the upper end of the ballscrew 106. The spline shaft 108 engages a boss of a worm wheel 110 such that the worm wheel 110 is slidable on the spline shaft 108. The worm wheel 110 engages a worm 114 which is connected to a second servomotor 112. That is, a rotary motion of the second servomotor 112 is transmitted to the spline shaft 108, via the worm 114 and the worm wheel 110 which serve as a speed reducer. Like the first servomotor 78 provided with the first encoder 86, the second servomotor 112 is provided with a second encoder 116. In the above arrangement, an operation of the second servomotor 112 in one direction will cause the ballscrew 106 to be rotated in one direction to move the rod mover 104 away from the spindle mover 74, whereby the rod 92 is lowered relative to the tool body 12. As a result, the honing stones 16 are moved in the radially outward direction by an amount proportional to the distance of downward movement of the rod 92. Similarly, an operation of the second servomotor 112 in the opposite direction will cause the ballscrew 106 to be rotated in the opposite direction, whereby the rod 92 is lifted toward the spindle mover 74. Accordingly, the honing stones 16 are moved in the radially inward direction by an amount proportional to the distance of upward movement of the rod 92. Since the ballscrew 106 is supported by the spindle mover 74 such that the ballscrew 106 is rotatable relative to the spindle mover 74 and axially movable with the spindle mover 74, the relative axial position between the rod mover 104 and the spindle mover 74, and consequently the relative axial position of the rod 92 and the tool body 12 are kept unchanged, unless the ballscrew 106 is rotated. A cylindrical member 120 is coaxially fitted via a pair of radial bearings 122 on a portion of the second spindle 42 below the rod mover 104. Between the radial bearings 122, there is formed an air chamber 128 whose fluid tightness is maintained by a pair of seals 124, which fluid-tightly engage the outer circumferential surface of the second spindle 42 and the inner circumferential surface of the cylindrical member 120. This air chamber 128 is connected to an external air pressure source 130. The functions of the air chamber 128 and pressure source 130 will be described later. In upper and lower end portions of a bore formed through the cylindrical member 120, there are fixedly disposed two stationary coils 132, 134 in opposed relation with the outer circumferential surface of the second spindle 42. Within these stationary coils 132, 134, respective two rotating coils 136, 138 are mounted on the outer circumferential surface of the second spindle 42 such that there are left predetermined clearances between the opposed stationary and rotating coils 132, 136, and 134, 138. The upper stationary coil 132 is connected to an external power source 140 via an inverter 142, so that an AC voltage of a predetermined frequency is applied to the stationary coil 132. Accordingly, a voltage is produced by the corresponding rotating coil 136. This voltage is applied via a conductor 144 to the voltage-frequency converter 48 in the first spindle 40. On the other hand, the lower rotating coil 138 receives via a conductor 146 a frequency signal generated from the voltage-frequency converter 48. As a result, the corresponding stationary coil 134 generates a voltage signal corresponding to the received frequency signal. This voltage signal is applied to an external processing circuit 150 via a conductor 148. There will next be described in detail the guides 26, air passages 30 and air nozzles 32 of the honing head 10, the pressure-voltage and voltage-frequency converters 46, 48 incorporated in the first spindle 40, the air chamber 128 in the second spindle 42, the external air pressure source 130, and the processing circuit 150. These members constitute an automatic sizing device 150 of an air micrometer type for measuring the inner diameter of the cylinder block 62. A stream of high-pressure air delivered from the air pressure source 130 is supplied to the air nozzles 32 through the air chamber 128, air passage 154, pressure-voltage converter 46, air passages 156 (shown in FIG. 3), and air passage 30, and is spouted from the air nozzles 32 against the surface of the cylinder bore 64 of the cylinder block 62, at right angles to the surface. The back pressure of the air nozzles 32 has a certain relationship with a gap between the open end of the air nozzles 32 and the surface of the cylinder bore 64. This back pressure is converted into a corresponding voltage signal by the pressure-voltage converter 46, and the voltage signal is converted by the voltage-frequency converter 48 into a corresponding frequency signal. The frequency signal is fed to the processing circuit 150 via the rotating and stationary coils 138, 134. The frequency signal is then converted by the processing circuit 150 into a corresponding pulse signal corresponding to the frequency represented by the frequency signal. By reference to FIG. 4, a honing control circuit 160 of the instant honing machine will next be described in detail. This control circuit 160, whose major portion is constituted by a computer, includes a central processing unit (CPU) 162, a read-only memory (ROM) 164, a random-access memory (RAM) 166, an input port 168, an output port 170, and a bus 172. To the input port 168, there are connected the torque sensor 58 and the processing circuit 150 of the automatic sizing device 152. Also, the encoders 86, 116 of the first and second servomotors 78, 112 are connected to the input port 168 via a first and a second servo amplifier 174, 176, respectively. On the other hand, the output port 170 are connected to motor portions 180, 182 of the servomotors 78, 112, via the respective first and second servo amplifiers 174, 176. The first and second servo amplifiers 174, 176 receive command signals from the output port 170 and feedback signals from the first and second encoders 86, 116. The feedback signals represent rotating angles of the output shafts of the first and second servomotors 78, 112. The servo amplifiers 174, 176 calculate differences between the command and feedback signals, and command the motor portions 180, 182 of the servomotors 78, 112 so that the differences are zeroed. A honing operation on the instant honing machine is effected according to a control program stored in the ROM 164 of the honing control circuit 160. Initially, the honing head 10 is introduced into the cylinder bore 64 of the cylinder block 62, and data representative of determined various honing conditions such as the amount of stock removal is entered into the RAM 166. Upon activation of a start switch of the machine, the spindle motor 54, and the first and second servomotors 78, 122 are operated under the determined conditions. The honing head 10 is rotated while it is reciprocated over a controlled range in the axial direction. Examples of controlled reciprocation patterns of the honing head 10 within the cylinder bore 64 are illustrated in FIGS. 5, 7 and 9. If there exist intolerable amounts of errors in diameter, roundness and cylindricity of the cylindrical bore 64 after a pre-honing machining operation or during a honing process, the errors should be reduced to within predetermined tolerances, by controlling the range and rate of axial reciprocation of the honing stones 16, and a honing rate at which the honing stones 16 are radially fed against the surface of the cylinder bore 64 in the radially outward direction. The examples shown in FIGS. 5-9 relate to honing operations on the cylinder bore 64 which has a poor degree of cylindricity. The paths shown in FIGS. 5, 7 and 9 are taken by the open end of the air nozzles 32 during reciprocation of the honing head 10. In these figures, character C represents an UP time during which the honing stones 16 are lifted from a lower stroke end ZL up to an upper stroke end ZU, while character D represents a DOWN time during which the stones 16 are lowered from the upper stroke end ZU down to the lower stroke end ZL. For the sake of explanation, a sum of the UP and DOWN times C and D is referred to as one honing cycle. While the honing stones 16 are in a lowering stroke (corresponding to the DOWN time D), the diameter of the cylinder bore 64 is measured at the upper stroke end ZU, lower stroke end ZL, and an intermediate position ZM between the stroke ends ZU and ZL. While the stones 16 are in a lift stroke (corresponding to the UP time C), the CPU 162 calculates, based on the measured diameter values, an amount of change ΔZU of the upper stroke end ZU and an amount of change ΔZL of the lower stroke end ZL, in order to change the range of reciprocation of the honing stones 16 (honing head 10), according to the following equations (1) and (2): ΔZU=α(DM-DU), (1) ΔZL=α(DL-DM), (2) where, DU: Cylinder bore diameter measured at ZU DM: Cylinder bore diameter measured at ZM DL: Cylinder bore diameter measured at ZL α: Predetermined constant Described more specifically by referring first to the example of FIG. 6 wherein the diameter of the cylinder bore 64 measured at the intermediate position ZM is smaller than those measured at the upper and lower stroke ends ZU, ZL of the head 10, the amounts of change ΔZU and ΔZL are first calculated based on the diameter values measured at ZU1, ZM1 and ZL1 in a given honing cycle, as indicated in FIG. 5. Then, the lower stroke end ZL2 of the next honing cycle is determined such that the lower stroke end ZL2 is located above the preceding lower stroke end ZL1 by the calculated amount ΔZL. Further, the upper stroke end ZU3 of the third honing cycle is determined such that the end ZU3 is located below the preceding upper stroke end ZU2 of the second honing cycle by the calculated amount ΔZU. As a result, the range of upward or lifting movement of the honing stones 16 is narrowed and limited to the relatively intermediate portion of the cylinder bore 64, as indicated in FIG. 5, so that the honing stones 16 hone primarily the intermediate portion of the bore 64. In the case where the diameter of the cylinder bore 64 measured at the intermediate position DM' is larger than those measured at the upper and lower stroke ends DU', DL' as indicated in FIG. 8, the amounts of change ΔZU' and ΔZL' are first calculated based on the diameter values measured at ZU1', ZM1' and ZL1' in a given honing cycle, as indicated in FIG. 7, in the same manner in which the amounts of change ΔZU and ΔZL are calculated. Then, the lower stroke end ZL2' of the next honing cycle is determined such that the lower stroke end ZL2' is located below the preceding lower stroke end ZL1' by the calculated amount ΔZL'. Further, the upper stroke end ZU3' of the third honing cycle is determined such that the end ZU3' is located above the preceding upper stroke end ZU2' of the second honing cycle by the calculated amount ΔZU'. As a result, the range of upward or lifting movement of the honing stones 16 is broadened, as indicated in FIG. 7. Consequently, the upper and lower end portions of the cylinder bore 64 are honed for an increased length of time. In a honing operation, it is required that a pressure of contact between the honing stones 16 and the surface of the cylinder bore 64 be constant over the entire length of the cylinder bore 64. Namely, the contact pressure at the open ends of the bore 64 should be almost equal to that at the axially middle point of the bore 64, in order to assure almost equal amounts of stock removal at the open ends and middle point of the bore 64. To this end, it is desirable that the honing stones 16 move beyond the open ends of the cylinder bore 64 by a suitable distance, at the turning points of the reciprocating movements. In other words, it is desirable that the honing stroke of the honing stones 16 be greater than the axial length of the cylinder bore 64 by a suitable overrun distance. However, there may be some geometrical or configurational restrictions that prevent a sufficient amount of such overrun distance of the honing stones 16. For instance, no overrun distance of the stones 16 can be provided at the end of the cylinder bore 64 which is closed. In this case, the diameter of the closed end of the bore 64 tends to be smaller than that at the intermediate portion of the bore 64. In view of the above, the honing times for the end portions of the cylinder bore 64 per unit length of the bore are increased as compared with that for the intermediate portion of the bore 64, by automatically adjusting the reciprocating speed of the honing head 10, depending upon the axial positions of the bore 64, as described below. Referring to FIG. 9, there will be described in detail the above aspect of the invention wherein the reciprocating speed or rate of the honing head 10 is automatically controlled. Based on the diameter values of the cylinder bore 64 as measured at the upper and lower stroke ends ZU, ZM and the intermediate portion ZM of the bore 64, amounts of change ΔTU, ΔTL of honing times TU, TL for honing the upper and lower end portions of the bore 64 by the stones 16 are calculated according to the following equations (3) and (4): ΔTU=β(DM-DU), (3) ΔTL=β(DL-DM), (4) where, β: Predetermined constant If the honing times TU and TL for honing the upper and lower end portions of the bore 64 are determined as indicated above, the end portions of the bore are honed for longer times per unit length of the bore, than the intermediate portion of the bore. That is, even if the honing stones 16 cannot have a sufficient overrun distance beyond the upper and lower ends of the cylinder bore 64, the end portions of the bore can be honed by the same amount as that when a sufficient overrun distance was provided. Described in more detail in connection with the example of FIG. 9 wherein the honing stones 16 are held in contact with the upper end portion of the bore 64 for a time duration of TU1 in a given honing cycle, the amount of change ΔTU1 is calculated based on the diameter values of the bore 64 measured in the same honing cycle at the upper stroke end ZU1 of the stones 16 and at the intermediate portion ZM1 of the bore 64. Then, a honing time TU3 in the third honing cycle is determined such that the time TU3 is longer by the calculated amount of change ATU1 than a honing time TU2 in the second honing cycle. Similarly, a honing time TL for honing the lower end portion of the bore 64 (at and near the lower stroke end ZL) is determined in the same manner. Thus, the speed distribution of the reciprocating movement of the honing stones 16 (honing head 10) is automatically controlled such that the time duration for which the honing stones 16 are kept in contact with the end portions of the cylinder bore 64 is changed by an amount proportional to the difference between the diameter values of the bore 64 as measured at the stroke end of the stones 16 and at the axially middle portion of the bore 64. Referring to FIG. 10, there will be described a manner in which the honing speed Vc (i.e., a rate at which the honing stones 16 are fed against the surface of the cylinder bore 64) is controlled. In the instant embodiment, a honing operation on the cylinder bore 64 is effected in three steps. Namely, a honing operation consists of a rough honing step, a regular honing step and a finish honing step. These honing steps are conducted at predetermined different honing speeds Vc. If the surface smoothness of the bore 64 is extremely low, however, the honing resistance between the stones 16 and the bore surface 64 in the rough honing step may be outside a predetermined optimum range. In the instant example, a spindle torque "t" which relates to the honing resistance is monitored. If the monitored spindle torque "t" becomes outside a predetermined range, the CPU 162 determines that the honing resistance becomes outside the optimum range, and adjusts the honing speed Vc. More specifically, if the spindle torque "t" exceeds an upper limit t max of the optimum range or becomes smaller than a lower limit t min of the optimum range, the CPU 162 calculates a difference Δt i between the values "t" and t max , or a difference Δt d between the values "t" and t min , and updates the honing speed Vc based on the calculated difference Δt i or Δt d , according to the following equations (5) and (6): Vc'=Vc-γΔt.sub.i, (5) Vc'=Vc+γΔt.sub.d, (6) where, γ: Predetermined constant There will be described in detail the manner of updating the honing speed Vc (the rate at which the radial position of the honing stones 16 is changed). For example, the monitored spindle torque "t" may exceed the upper limit of a predetermined optimun range RH indicated at "a" in FIG. 10 (top graph), if the stock removal rate of the honing stones 16 is excessive in the rough honing step due to poor positioning of the cylinder block 62 or excessive amount of stock removal, or if the honing stones 16 are about to be or have been loaded or glazed. In this case, the second servomotor 112 is activated to move the honing stones 16 in the radially inward direction away from the surface of the cylinder bore 64. After the positioning error of the cylinder block 62 is corrected or after the loaded surfaces of the stones 16 are dressed, the rough honing operation is resumed, with a honing speed Vc (rate of movement of the stones 16 in the radially outward direction) which is lower than the last used value, by an amount of change γΔt i calculated according to the equation (5) indicated above. See the middle graph of FIG. 10. Then, the regular honing step is initiated when the amount of stock removal reaches a predetermined value φ1, as indicated at "b" in FIG. 10 (bottom graph). On the other hand, if the stock removal rate of the honing stones 16 in the regular honing step is excessively low, the spindle torque "t" becomes lower than the lower limit of a predetermined optimum range RC, as indicated at "c" in FIG. 10 (top graph). If the same honing speed Vc is maintained, the self-dressing function of the honing stones 16 is reduced, and the stones 16 tend to be loaded, whereby the honing time is unnecessarily increased. To avoid this, the honing speed Vc is increased by the calculated amount γΔt d , to accordingly increase the stock removal rate. When the amount of stock removal reaches a predetermined value φ2 indicated at "d" in FIG. 10 (bottom graph), the regular honing step is followed by the finish honing step. It will be noted that the speed or rate of reciprocating movement of the honing stones 16 can be readily controlled by regulating the operating speed of the electrically operated first servomotor 78. This is not possible in the known arrangement wherein the honing head is reciprocated by a hydraulically operated actuator. In the known arrangement, the speed at which the honing head is reciprocated near the turning points (stoke ends) is limited, that is, cannot be readily controlled. In the known arrangement, deceleration valves or other hydraulic components are generally required to lower the rate of movements of the honing stones near the ends of the cylinder bore to be honed, if the overrun distances of the stones beyond the ends of the bore are not sufficient. However, the hydraulically operated actuator is not capable of accurately controlling the reciprocating movement of the honing head, depending upon the difference between the diameter values measured at the end and intermediate portions of the bore, as indicated in FIG. 9. To the contrary, the instant arrangement wherein the honing head 10 is driven by the electrically operated actuator 78 is highly capable of controlling the speed distribution of the reciprocating movement of the head 10 (stones 16), depending upon the differences of the diameter values measured at the end and intermediate portions of the cylinder bore 64. Further, the electrically operated actuator 78 has a comparatively high degree of operating response to a change in the diametrical difference of the bore. It follows from the foregoing description that the conical members 24, rod 92, rod mover 104, ballscrew 106, and second servomotor 112 constitute a major portion of a changing mechanism for changing the radial position of the honing stones 16, i.e., for changing the honing speed Vc or the rate of radial movement of the stones 16 against the surface of the cylinder bore 64. The second servomotor 112 serves as a drive source of the changing mechanism. It will also be understood that the first and second spindles 40, 42, spindle mover 74, ballscrew 76 and first servomotor 78 constitute a major portion of a first drive device for effecting a relative reciprocating movement between the honing head 10 and the workpiece 62. The first servomotor 78 serves as a drive source of the first drive device. Further, the first and second spindles 40, 42 and spindle motor 54 constitute a second drive device for effecting a relative rotating movement between the honing head 10 and the workpiece 62. It will also be understood that the automatic sizing device 152 serves as a diameter measuring device for measuring the diameter of the cylinder bore 64 being honed, while the torque sensor 58 serves as a resistance measuring device for measuring the honing resistance between the honing stones 16 and the cylindrical surface of the workpiece 62. It is further understood that the honing control circuit 160 and the first servo amplifier 174 constitute a reciprocation control device for controlling the first servomotor 78 to determine the range of the reciprocating movement of the honing head 10 relative to the workpiece 62, and the speed distribution of the reciprocating movement of the honing head 10 (honing stones 16) over the range of the reciprocating movement. The control circuit 160 and the second servo amplifier 176 constitute a honing control device for controlling the second servomotor 112 to determine the radial position of the honing head 10 in the radial direction, i.e., honing speed Vc at which the honing stones 16 are fed against the surface of the cylinder bore 64 in the radially outward direction. While the present invention has been described in its presently preferred embodiment, the invention may be otherwise embodied. In the illustrated embodiment, the honing stones 16 are radially fed at a controlled rate against the surface of the cylinder bore 64 by the movement of the rod 92 driven by the second servomotor 112. However, the honing stones 16 may be radially fed under a biasing action of suitable biasing means such as a spring member disposed between the stones 16 and the rod 92, or a pressurized oil or air. In this case, the pressure of contact between the stones 16 and the surface of the bore 64 is suitably controlled, based on a difference between the actually measured honing resistance and the predetermined upper or lower limit. Further, the combination of the shoes 14 and the conical members 24 to radially move the stones 16 may be replaced by a suitable rack-and-pinion mechanism wherein the pinion is driven by the second servomotor 112. Although the diameter of the cylinder bore 64 is measured at three positions, i.e., at the upper and lower strokes ends ZU, ZL of the stones 16 and at an intermediate position ZM of the bore 64, it is possible to measure the diameter at four or more positions along the axis of the bore 64. In this instance, the reciprocating speed of the stones 16 may be varied at four or more axial positions of the bore 64, based on the measured four or more diameter values. In the illustrated embodiment, the honing head 10 is axially moved and rotated relative to the workpiece in the form of the cylinder block 62, the workpiece may be moved and rotated relative to the honing head 10 which is held stationary. While the illustrated embodiment is adapted to hone the internal cylindrical surface 64 of the workpiece 62, the principle of the present invention may be equally practiced for honing an external cylindrical surface of a workpiece. It will be understood that the invention may be embodied with various other changes, modifications and improvements, which may occur to those skilled in the art, without departing from the spirit and scope of the invention defined in the following claims.

A honing apparatus for honing a cylindrical surface of a workpiece, including a honing head supporting honing stones, a first drive device having an electrically operated bidirectional actuator for effecting a relative reciprocating movement between the honing head and the workpiece in an axial direction of the cylindrical surface, a second drive device for effecting a relative rotating movement between the honing head and the workpiece, a diameter measuring device for measuring a diameter of the cylindrical surface of the workpiece, and a reciprocation control device connected to the diameter measuring device and the electrically operated actuator. The control device is adapted to operate based on a measurement of the diameter by the diameter measuring device, to determine at least one of a range of the relative reciprocating movement, and a speed distribution of the relative reciprocating movement over a range of the relative reciprocating movement. The control device controls the electrically operated bidirectional actuator based on the determined range and/or speed distribution of the relative reciprocating movement.

CROSS REFERENCE TO RELATED APPLICATIONS This application is related to commonly-owned copending applications Ser. No. 429,794 filed Sept. 30, 1982, entitled TEXTILE FABRICS WITH OPAQUE PIGMENT PRINTING AND METHOD OF PRODUCING SAME, now U.S. Pat. No. 4,457,980 issued July 3, 1984; and application Ser. No. 435,949 filed Oct. 22, 1982, entitled COLORED OPAQUE PRINTING OF TEXTILE FABRICS USING DYE STUFFS, now U.S. Pat. No. 4,438,169, issued Mar. 20, 1984. FIELD AND BACKGROUND OF THE INVENTION This invention relates to textile pigment printing, and in particular to the production of a printed textile fabric wherein the printed areas are of a predetermined desired color and are characterized by being substantially opaque and thus unaffected by the color of the underlying yarns. This invention is related to and is an improvement over the invention described in the above referenced commonly-owned copending applications. These earlier applications disclose a unique new type of textile printing process and product in which the printed areas on the textile fabric are substantially opaque and are thus unaffected by the color of the underlying yarns. The aqueous opaque printing process and product of these earlier applications overcome a number of significant limitations and disadvantages of conventional pigment printing techniques and enable the production of a wide variety of patterns and colors not obtainable by the pigment printing techniques heretofore known. The printing paste which is used in the opaque printing process, unlike the aqueous printing pastes used in conventional screen printing operations, has opacity and can be applied over either dark or light background fabrics without being affected by the color of the underlying yarns. The resulting printed pattern areas on the fabric comprise an opaque coating which covers the exposed surfaces of the yarns which form the fabric. This coating comprises an opacifying pigment providing opacity in the coating and a cured water insoluble polymer binder which is affixed to the yarns and bonds the opacifying pigment to the yarns. The opaque coating which forms the printed pattern areas is characterized by individually coating each of the yarns in the printed area such that the interengaged yarn structure of the fabric is not obliterated, but remains visible. More specifically, the opaque coating at the surface of the yarn is such that the individual surface fibers of the yarn also are not obliterated and remain visible. The opaque coating which forms the printed pattern areas may be of any desired color. For relatively light colors, such as white, the opacifying pigment itself may be utilized for providing the desired colors. Other colors may be produced by including colored pigments or dyestuffs in the printing paste in addition to the opacifying pigment. The printing paste is applied to the fabric as a stable aqueous dispersion of the opacifying pigment and polymer binder. After printing on the fabric, the printing paste is dried and cured by heating, with a crosslinking reaction taking place, such that the polymer binder is converted from the aqueous solution or dispersion as it is applied to a tough flexible water insoluble pigmented opaque film. More particularly, the printing paste formulations described in the aforementioned applications rely on acrylic latex and/or aminoplast resins for crosslinking during curing. SUMMARY OF THE INVENTION The present invention provides an alternative procedure for producing cured aqueous opaque textile prints which offer a number of advantages over the abovedescribed system of the commonly-owned copending applications referred to earlier. In producing opaque printed areas on textile fabrics in accordance with the present invention, a printing paste is utilized which contains the opacifying pigment and a binder which is comprised of monomeric, oligomeric and/or polymeric units capable of being polymerized and cured by free radical initiation. After application of the printing paste to the fabric, the fabric is subjected to free radical initiation to polymerize and cure the binder and thereby bond the opacifying pigment to the yarns. In accordance with one aspect of the invention, the polymerizable binder is a radiation curable binder, and the fabric is subjected to free radical initiation by irradiating the fabric with high energy radiation. In another embodiment of the invention, the polymerizable binder additionally contains a free radical initiator, which may be activated by suitable means such as heating or exposure to radition; and by activating the initiation, the fabric is subjected to free radical initiation to thereby polymerize and cure the binder. An advantage of the free radical curing procedure of the present invention is that the printing paste does not require the presence of a catalyst, which sometimes causes yellowing or discoloration of the fabric under curing conditions. Atmospheric pollutants, associated with solvent systems such as in conventional opaque stencil printing are also eliminated. Additionally, this procedure in many instances makes it possible to carry out curing at a lower temperature, which has many advantages, such as energy savings, reducing fabric shrinkage, and permitting the curing to be carried out at a faster rate. BRIEF DESCRIPTION OF THE DRAWINGS Some of the features and advantages of the invention having been stated, others will become apparent from the detailed description and examples which follow, and from the accompanying drawing, which is a schematic illustration of an arrangement of apparatus suitable of carrying out the process of this invention. DETAILED DESCRIPTION The aqueous opaque colored printing paste of the present invention has a relatively high solids content, e.g. preferably at least 25 percent total solids, and consists mainly of an opacifying pigment and a free radical polymerizable binder mixed therewith to form a stable aqueous dispersion. To serve as an opacifying pigment for purposes of this invention, the material must be highly opaque, have color properties which permit it to be used alone or mixed with other colorants, such as dyes and colored pigments, and it must be readily dispersable at relatively high concentrations in the aqueous binder system. There are many commercially available materials having these characteristics. Where it is desired to provide a relatively light colored printed area, particularly against a relatively darker background color, the preferred opacifying pigment for use in the printing paste formulation of this invention is a white pigment. One particular white pigment which has been found to be especially suitable because of its bright white appearance, cost and availability is titanium dioxide. Other suitable white pigments include silicates, aluminum compounds, calcium carbonate, and the like. In order to achieve high chroma (color saturation) with certain hues, one or more opacifying pigments of lesser whiteness or of intermediate shades may be employed, either alone or in combination with white pigments. In addition to the white opacifying pigments noted above, examples of other compounds suitable for use as opacifying pigments in the present invention include the following: zinc oxide, zinc sulfide, lithopone (ZnS/BaSO 4 ), basic carbonate white lead, basic sulfate white lead, lead oxide (lead dioxide), calcium sulfate, barium sulfate, silica, clay (Al 2 O 3 .2SiO 2 .2H 2 O), lead sulfate, magnesium silicate, mica, wollastonite (CaSiO 3 ), aluminum hydrate, magnesium oxide, magnesium carbonate, aluminum oxide, ferric oxide, sodium carbonate, strontium sulfide, calcium sulfide, barium carbonate, antimonius oxide, zirconium white, barium tungstate, bismuth oxychloride, tin white, lead silicate, chalk, bentonite, barium sulfate, gloss white, gypsum, zinc phosphate, lead phosphate, and calcium silicate. For the printing of relatively dark colors, carbon black may be used as an opacifying pigment instead of a lighter colored pigment. The use of an opacifying pigment, particularly a white opacifying pigment, and the printing thereof against a darker background color, are features which clearly distinguish the opaque pigment printing of this invention over conventional non-opaque pigment printing techniques. In conventional pigment printing, white pigments are used only on a white or light shade background fabric for achieving a "white-on-light" effect. Conventional pastel or white pigment printing pastes are not generally applied to darker background colors, since such printing pastes would not provide adequate uniform opacity against the darker background color. The amount of the opacifying pigmet used in the printing paste formulation of this invention is considerably greater than the amount of pigment used in conventional aqueous-based non-opaque printing pastes, and is typically considerably greater than the total solids content of the polymer binder. In a preferred formulation, the printing paste comprises at least 20 weight percent opacifying pigment (solids basis) and at least 5 weight percent polymer binder (solids basis). The binder for the opacifying pigment must be capable of application in an aqueous system, form a stable dispersion with the insoluble opacifying pigments and other additives in the binder system, have good film-forming properties when applied to the fabric, and must be capable of being dried and cured to a water insoluble state imparting good washfastness and abrasion resistance properties to the printed pattern. The polymer binder may be suitably applied as an aqueous solution or dispersion. The print paste may be thereafter dried to a desired degree by suitable means, such as by heating, and cured via free radical curing as described more fully herein. The mechanism involved in free radical curing of the printing paste in accordance with the present invention is significantly different from that in conventional thermal curing. In the latter, strong catalysts, such as p-toluenesulfonic acid may be employed with cross-linking agents which cure when the printing paste is subjected to elevated temperatures. Free radical curing relies upon the presence of free radicals for the initiation of a free radical addition polymerization reaction. Thus, in order to achieve the curing, selected monomers, oligomers, polymers, or mixtures of these are included in the print paste which contain functional groups which are susceptible to free radical addition polymerization. Generation of the free radicals needed to initiate the polymerization reaction may be accomplished in a number of different ways. Certain compounds, such as styrene for example, will polymerize by free radical polymerization with application of heat alone. Other compounds require free radical initiators to provide the free radicals necessary for the free radical polymerization reaction to take place. The free radical initiators may be in the form of chemical compounds which will generate free radicals upon being subjected to certain influences, such as heating or radiation. Examples of chemical compounds which may be used as initiators to generate free radicals with heating include, but are not limited to, benzoyl peroxide, acetyl peroxide, azodiisobutyronitrile, t-butylhydroperoxide, cumene hydroperoxide, t-butylperoctoate, di-t-butyl peroxide, succinyl peroxide, dicermyl peroxide, dichlorobenzoylperoxide, azodicyclohexylcarbonitrile, and ethoxyethoxyethyl acrylate. Examples of monomers, oligomers and/or polymers that are capable of curing through free radical addition polymerization include, vinyl monomers, substituted ethylenes, conjugated dienes, non-conjugated dienes, polysiloxanes, N-vinyl-2-pyrrolidone, 2-methyl butadiene, vinylnaphthalene, glycol dimethacrylate, vinylacetate, acrylamide, methyl acrylate, methyl methacrylate, pentaerythritol acrylate, vinyltriethoxy silane, vinyl functional polydimethylsiloxane, curable urethane monomers, etc. As an alternative to the use of chemical free radical initiators, it is possible to initiate free radical polymerization by irradiation with actinic radiation. The most well known methods of radiation curing are electron beam (EB) curing and ultraviolet light (UV) curing. Typically, UV curing requires the inclusion of a photoinitiator for free radical generation. EB curing, on the other hand, relies on the generation of free radicals via the transfer of kinetic energy from the accelerated electron to the polymer. There are a wide range of monomers, oligomers and polymers which are suitable for high energy irradiation curing. These include, but are not limited to, acrylate and methacrylate monomers and oligomers such as acrylated epoxies, urethanes, polyesters and acrylics, multifunctional monomers, maleates, vinyl compounds such as vinylethyl ethers, linear polyesters, and maleates or itaconates of mono or polyhydric alcohol, and N-vinyl-2-pyrrolidone. In addition to the opacifying pigment and free radical curable binder, the printing paste may optionally include colorants, such as colored pigments or dyes, for providing the desired color to the printing paste. The dyes which may be suitably employed for coloring the binder may comprise at least one member selected from the group consisting of acid dyes, cationic dyes, direct dyes, disperse dyes, fiber reactive dyes, mordant dyes, and solvent dyes. Azoic dyes, vat dyes, and sulfur dyes may also be used; however, the azoic compounds, vat dyes and unreduced sulfur dyes would in effect behave as pigments since in the unreduced form they are insoluble. Silicone fluids and elastomers may be incorporated into the printing paste to aid in obtaining a smooth application of the pigment to the fabric. The use of silicone polymers has been found to provide dots or designs free of rough edges and crack marks. Conventional thickeners may also be utilized to control the viscosity and rheology of the paste, depending upon the size and design of the print pattern and the running speed of the print screen. The paste may also contain other conventional additives, such as emulsifiers, antifoam agents, and pH control agents. It is important that the printing paste have good wetting and film-forming properties so that when applied to the fabric, it will penetrate and coat the individual yarns of the fabric rather than remaining on the surface of the fabric. If these properties are not adequately presented by the polymer binder itself, suitable wetting agents or emulsifiers may be included. The printing paste may be applied either to uncolored (e.g. white) fabrics or to precolored fabrics, the precolored fabrics being of a predetermined color throughout and produced by any suitable method such as by piece dyeing, yarn dyeing or by pigment padding, for example. The particular rate of application of the printing paste to the fabric will vary depending upon various factors, including fabric weight and construction, color of the fabric, and printing color. Drying and curing of the printing paste may be carried out under conditions of temperature and time suitable for the particular manner of application and curing mechanism employed. For rotary screen printing of a paste containing thermally activated chemical free radical initiators, for example, drying and curing may be carried out at temperatures of 250 to 425 degrees F. for from several seconds up to several minutes. When the fabric is cured and dried, the areas printed with the printing paste are characterized by having a thin flexible opaque coating covering the exposed surfaces of the yarn and thus hiding from view the underlying color of the yarn. The coating consists predominantly of the opacifying pigment bonded securely to the yarns by the cured water insoluble polymer binder. An arrangement of apparatus suitable for carrying out the process of the present invention is schematically illustrated in the drawing. As shown, a fabric F is advanced from a suitable supply source, such as roll 10 through a rotary printing range, generally indicated at 12 consisting of a series of rotary printing cylinders. Rotary textile printing ranges are well known in the art, and therefore a detailed description of its construction and operation is not warranted. After leaving the printing range 12, the fabric is advanced through a heating zone 14 for drying the printing paste. The heating zone 14 may suitably comprise a heated tenter frame as is conventional in the art. When curing a free radical curable binder containing thermally activatable free radical initiators, the heat provided in the heating zone 14 alone is sufficient for generating the free radicals necessary for polymerization and curing. As shown in the drawing, however, for radiation curable compositions, a radiation source 16, such as ultraviolet lamps or an electron curtain, may be located upstream from the heating zone for directing radiation onto the fabric for thereby initiating free radical generation and curing. Alternatively, the electron curtain 16 may be located downstream from the drying zone 14. After drying and curing of the printing paste has been been effected, the fabric F may be taken up on suitable means such as a roll 18 as illustrated. Because of the excellent opacity of the aqueous opaque colored printing paste formulations of the present invention, which permits printing vivid contrasting colors on predyed fabrics of any desired color, and the fact that the printing paste formulations of this invention can be readily applied on conventional rotary screen printing equipment, the present invention makes it possible to produce a variety of colors and patterns not heretofore possible. Thus, one additional aspect of the present invention is the production of a printed textile fabric formed of precolored yarns, and in particular dyed yarns of a predetermined color, selected areas of the fabric having printed pattern areas of predetermined color contrasting with the color of the yarns, the printed pattern areas being substantially opaque and thus unaffected by the color of the yarns, and the pattern areas being formed of a plurality of colors contrasting with one another and with said predetermined color of the yarns, at least one of the colors being lighter than said predetermined color dyed yarns, and said pattern areas comprising a filmlike coating covering the exposed surfaces of the yarns, said coating comprising an opacifying pigment providing opacity in said coating and a free radical cured binder securely bonding said opacifying pigment to the yarns. EXAMPLES 1 AND 2 The following examples illustrate opaque print paste formulations which use addition polymerization reactions initiated by chemically generated free radicals to promote curing. ______________________________________ Percent______________________________________Example 1Pioneer White BS Pigment 57Blockout B (aluminum 13silicate dispersion)Urethane Oligomer (Uvithane 782) 29Benzoyl Peroxide 1Example 2Pioneer White BS Pigment 57Blockout B (aluminum 13silicate dispersion)Urethane Oligomer (Uvithane 783) 14V-Pyrol 15Benzoyl Peroxide 1______________________________________ The print pastes are brought to a suitable viscosity with a conventional print paste thickener, depending on the type printing machine employed--rotary screen, flatbed, etc. The fabric is then printed and cured as normal at approximately 360° F. or thermosoled up to 425° F. EXAMPLES 3 AND 4 The following examples illustrate opaque print paste formulations containing irradiation curable monomers. ______________________________________ Percent______________________________________Example 3Pioneer White BS Pigment 57Blockout B (aluminum 13silicate dispersion)Pentaerythritol Acrylate 28(Uvithane ZA-1192)Photoinitiator (diethoxy- 2acetophenone)Example 4Pioneer White BS Pigment 57Blockout B (aluminum 13silicate dispersion)Ethoxyethoxyethyl Acrylate 28(Reactomer RC-20)Photoinitiator (diethoxy- 2acetophenone)______________________________________ The viscosity of the print paste is adjusted to that necessary for the particular printing machine used, rotary screen, flatbed, etc. using a conventional printing thickener. After printing the fabric may either be dried in a conventional oven, then irradiated or simply irradiated immediately after printing, depending on the drying achievable during irradiation. Duration of irradiation depends on the type of irradiation equipment employed; U.V., electron beam, electron curtain, etc., and the intensity of the dose rate. In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

Highly opaque printed areas are produced on uncolored or precolored fabrics pursuant to this invention with the use of an aqueous opaque printing paste comprising a dispersion of an opacifying pigment and an aqueous binder which is cured by free radical initiation. In accordance with the invention multicolor prints with a variety of unique and visually appealing shade possibilities and color effects not heretofore possible are achieved.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of Ser. No. 60/579,260 filed Jun. 15, 2004. FIELD OF THE INVENTION [0002] The present invention relates to accessories for seating devices. More specifically, it relates to a protective cover that is multi-purpose, and easily deploys and collapses for use on a variety of seating devices. BACKGROUND OF THE INVENTION [0003] For many years manufacturers have addressed the need for protective enclosures for seating devices that protect the occupant from hazards such as sun, wind, rain, snow, cold, blowing sand, insects, contact by strangers, saliva aerosol, cold, moderate and tropical climates, and the like. Protective covers have been designed to provide for a total encapsulation of the occupant, while considering the importance of ventilation, that the cover can be interchangeably affixed to a variety of seating device types and models, that the cover be easily removed, that it installs and removes quickly, that it be compactly stowed away, and that it be affordably constructed. [0004] A wide variety of seating devices require protective covers that protect from afore mentioned hazards. [0005] For example, children and adults who are indisposed to walking are frequently transported in mobile carriages from one location to another. A wide variety of mobile carriages such as wheel chairs are employed. Children are transported in strollers, which come in a wide variety of configurations such as, for example, a jogger type stroller of U.S. Pat. No. D481,976 to Everett, a four wheeled stroller of U.S. Pat. No. D486,098, or an umbrella stroller of U.S. Pat. No. 3,917,302 to Gebhard, double strollers such as that of U.S. Pat. No. D486,099 to Chen, or tandem stroller per U.S. Pat. No. 6,527,294 to Brewington et al. [0006] In another example, infants are routinely transported in infant seats, baskets or wheeled infant seats of various forms from one location to another. A wide variety of seats are employed. Vehicle seats, generically referred to as car seats have been adapted for use in automobiles, on strollers, or to be carried by hand. These seats can also double as stationary seating for the infant. Shopping carts are frequently equipped with permanently affixed infant seats that resemble car seats but do not have handles. Infants are also frequently placed in bouncy chairs, specially designed infant swings, glide swings and the like for entertainment and in order allow the relatively immobile infant to have a view and to be in view of an adult. As infants have changing needs during transit or when stationary, they are frequently removed and replaced from the seat by the caregiver. [0007] Many further examples of mobile and stationary seating devices exist such as the bouncy chair of U.S. Pat. No. 5,411,315, an infant seat mounted to shopping cart, infant swing device, or wheeled infant seat per U.S. Pat. No. 6,513,827, or U.S. Pat. No. 5,104,134. Other seating devices to which this invention has applicability will become apparent to those of skill in the art. [0008] Dedicated covers to protect occupants of seating devices are well known. One such cover is shown in U.S. Pat. No. 1,339,527 to Sperling et. al. which describes a collapsible screen for baby carriages which has side flaps and is rolled for storage. This screen requires that the carriage have a particular frame for mounting and is therefore not universal. [0009] U.S. Pat. No. 1,412,935 to GreeneBaum shows a baby carriage screen as foot and head portions that are attached to the handle in the middle of the carriage. [0010] U.S. Pat. No. 3,227,484 to Merclean describes a rain protective cover that uses an elasticized strap to fasten to a stroller, and an overhead canopy frame for ceiling support. [0011] U.S. Pat. No. 4,533,170 to Banks et al. discloses a self-supporting frame for a stroller or similar infant conveyance device comprised of collapsible poles that can be compacted lengthwise. Although this design does not require a canopy for ceiling support, it has limited collapsibility, as its spring rod members are normally straight and rigid, thereby requiring them to be forced into a coiled shape. [0012] U.S. Pat. No. 4,582,355 to Hall describes a weather guard for a carriage or stroller which is made of an impervious clear plastic material and which relies upon a pre-existing canopy structure for maintaining a ceiling. [0013] U.S. Pat. No. 5,168,889 to Diestel discloses an overhead canopied cover for a wheel chair that relies upon a tubular frame that is disassembled when not in use. [0014] U.S. Pat. No. 5,184,865 to Mohtasham et al. describes collapsible insect netting that is either comprised of a retractable cover, which utilizes a circular rib bearing unit to pivot out of the way, or is comprised of resilient spring rods in an arched configuration that require disassembly for storage. Rain protection is not disclosed. [0015] U.S. Pat. No. 5,542,732 to Pollman discloses a supplementary shade for a canopied stroller. Apart from not covering the legs of the stroller occupant, this shade does not disclose rain or insect protection. [0016] U.S. Pat. No. 5,522,639 to Jaime discloses an infant carrier seat having dual sun visors mounted at the foot and head that stow away in compartments that are built into the foot and head of the seat. While this design allows for unobtrusive positioning of the sun visors, the sun visors disclosed are not intended for interchangeability with incompatible or dissimilar seats. [0017] U.S. Pat. No. 5,730,490 to Mortenson shows a protective cover for an infant car seat, which keeps the ceiling of the cover away from the infant by attaching it to the handle with straps. This cover can only be used on infant carrier seats that come with handles. In addition, this cover cannot be used when the handle is stowed for transport in an automobile, which is a normal requirement for fastening car seats with rotating handles into automobiles. [0018] U.S. Pat. No. 5,975,558 to Sittu illustrates an adjustable shade to be used with a stroller having an integral canopy. Apart from not coving the legs of the stroller occupant, this shade does not disclose rain or insect protection. [0019] U.S. Pat. No. 5,975,613 to Sippel illustrates a sunshade for a stroller which covers the occupant completely and which relies upon a rectangular canopy that is permanently pivotally attached to the stroller. Two layers of shade cloth, one being a mesh and the other being a cotton material that is not transparent, achieve shading. No rain or insect protection is disclosed. [0020] U.S. Pat. No. 6,012,756 to Clark-Dickson discloses a shade cover to be used with a hooded pram or stroller to protect from UV radiation. No rain or insect protection is disclosed. [0021] U.S. Pat. No. 6,039,393 to Roh depicts a protective cover for an infant carrier seat that keeps the ceiling away from the occupant either by means of a resilient U shaped self-supporting element that is sewn into the cover ceiling and laterally mounted at the approximate midpoint of the length of the carrier, or by means of a cover support attachment that is affixed to the infant seat-carrying handle. The limitation of affixing the ceiling to the carrying handle has been discussed above. The U shaped element enables the cover to be interchangeably affixed to infant carriers with or without handles while keeping the ceiling away from the occupant. As a result of lifting the ceiling away from the occupant, it is disclosed that side section (length wise) ventilation is provided when an opaque inclement weather hood with a base hood width is used. However, as the geometry of the U shaped supporting element defines the greatest cross sectional area, forming a semi-circle, in the width-wise direction only, the effect is that the length-wise side section ventilation is constrained by the limited side section surface area afforded by the U shaped support element geometry. In addition, the small side section surface area that results from the geometry of this cover reduces the overall volume of space available to the occupant, which has the potential of causing distress to the infant due to feelings of confinement. [0022] It is also disclosed in U.S. Pat. No. 6,039,393 to Roh that by removing the elasticized skirt from the perimeter of the seat the occupant can be accessed. A means of accessing the infant without removing the cover skirt from the perimeter of the seat is not disclosed. In practice, this technique of accessing the infant is impractical when one considers that removing the elastic from one edge removes tension from the entire cover perimeter seal, which has the effect of collapsing the ceiling, thereby requiring complete removal or temporary stowing of the cover so that it can be out of the way for access to the infant. Furthermore, as the cover must be replaced every time it is needed, the adult is not only required to strap the infant into the seat, but to ‘fuss’ with affixing the perimeter of the cover and keeping the ceiling away from the occupant while trying to secure the unit. [0023] U.S. Pat. No. 6,068,322 to Kuester discloses a cover for a baby buggy, which is intended to protect an infant from air pollution and is comprised of a non-air permeable fabric to enable maintenance of positive pressure by a fan unit, which provides all necessary ventilation to the occupant. Arched stays are employed to provide ceiling support of the canopy, which must be disassembled when stowing away. Although good for extremes of pollution, this design relies primarily upon self-powered mechanical ventilation rather than natural ventilation. Rain and insect protection is not disclosed. [0024] U.S. Pat. No. 3,960,161 to Norman describes a saddle-shaped geometry of a collapsible tent that is held stable by securing the tent to the ground with ties. Another embodiment is in a “potato chip” shape and is described as a novelty of child toy that is also unstable in the form disclosed without the use of ties. [0025] U.S. Pat. No. 6,109,282 to Yoon provides for a self erecting and self supporting tent comprised of a flexible sheet like material, side panels, and a resilient closed loop frame member with an hour glass shape such that this structure, when erected, is stable without the use of ground ties or a floor due to connection of the opposing rounded lower edges to the body ends. This method of maintaining the arched configuration, although feasible for a tent is not amenable to other applications in which the side panel lower edges must remain flexible for attachment to seating devices. The method of collapsing is by twisting the tent into a figure eight shape and folding to a compact form, repeating this process as necessary depending upon the size of the cover. This twisting procedure for collapsing results in the collapsed tent fabric being turned inside out, resulting in a tangled collapsed tent that is often time consuming to disentangle and deploy during the self erecting process. An hourglass-shaped ceiling is disclosed as the means of stabilizing the tent in place of ties. This hourglass shaped tent is not particularly amenable to applications where the ceiling surface area needs to be maximized at the mid span, nor is it necessary in situations where self-support is not required. [0026] U.S. Pat. No. 6,155,628 illustrates a flexible cloth-like sunshade for a jogger type stroller that is designed primarily for overhead shading, and does not protect from sun ingress at the side of the stroller as it is not encapsulating, nor is this design suitable for strollers that are not tricycle type due to the nature of the mounting bracket disclosed. Rain and insect protection is also not disclosed. [0027] U.S. Pat. No. 6,217,099 to McKinney et al. discloses a multi-layered protective shield for a stroller that overcomes the need for an overhead canopy by means of an inflatable frame support member. Although it does disclose that the inflatable frame members' rigidity will be sufficiently rigid to support the weight of the protective layers when inflated, resistance to say, tampering by the occupant, or strong winds is not explicitly addressed. This design also omits the applicability of this cover to jogger type strollers, and to the practicality of installation that requires inflation and attachment of the inflated member to the stroller. [0028] U.S. Pat. No. 6,224,073 to Au discloses a collapsible windscreen comprised of two side panels reinforced by resilient loop material covered in flexible material extended across each loop member. These side panels mount to the sides of a pram or stroller by means of strapping such as Velcro™. A flap of material joins these two loops to form a ceiling. This cover is collapsible by means of detaching the unit from the stroller, sandwiching together the two panels and twisting into a figure eight form to compact. Rain protection is disclosed in addition to wind protection. [0029] In practice, collapsing by twisting the unit's sandwiched side panels into a figure eight and then into a loop takes some practice to master, even when instructions are provided. Additionally, although the requirement for an overhead canopy stroller is not disclosed for use in conjunction with this windscreen, the side panel mount configuration presents an unstable and drooping ceiling when a canopy is not present, leading to pooling of water in the rain resistant embodiment, and circumstances of confined overhead space in both embodiments. Also, access to the occupant is difficult without removal of the cover because the side panels are fixed, and a front panel is stretched between the two side panels, unless the caregiver accesses the occupant via the drooping ceiling when a canopy is not present. Furthermore, this design does not disclose protection from insects. [0030] U.S. Pat. No. 6,517,153 to Brewer shows a protective cover for infant carrier seat that keeps the ceiling away from the occupant by means of the flexible canopy support member that is permanently affixed to the infant carrier. Therefore this cover is limited by its inability to be interchangeably affixed to infant seats that do not have this canopy support member. [0031] As a diversity of seating product configurations proliferate, there still exists a need for a protective cover that can be interchangeably affixed to a multiplicity of seating products and the like that protect against the afore mentioned hazards, and addresses the deficiencies of known protective cover arrangements. [0032] It is a well-known ventilation engineering principle that to maintain the same quality of ventilation, a small encloses space with a window of a given cross sectional area and one occupant will require more frequent air changes per hour than a larger enclosed space with the same window size. In addition, if the larger room is provided with a larger window, the speed of air replacement will increase, thereby further improving the ventilation for the occupant. Accordingly, it is an object of this invention to provide a protective cover, which overcomes the afore mentioned hazards and that can be interchangeably affixed to a multiplicity of seating products and the like that substantially encapsulates the occupant, while improving ventilation by increasing the internal volume of the protective cover by increasing the overall surface area generally, and specifically by increasing the side panel ventilation cross sectional area. [0033] It is a commonly accepted fact that confined spaces can result in unwanted psychological effects such as for example feelings of confinement or claustrophobia. Increasing the space afforded to an occupant of an enclosure such as a protective cover helps to mitigate these unwanted effects. Additionally, providing a panoramic view to the occupant can also mitigate these unwanted effects. Therefore, it is an object of this invention to provide a protective cover, which overcomes the afore mentioned hazards and that can be interchangeably affixed to a multiplicity seating products and the like that increases the internal volume and affords a panoramic view and therefore reduces the potential for unwanted psychological effects associated with a protective cover with a smaller internal volume. [0034] Known protective covers have provided ports for viewing the occupant such as from side vents or ceiling windows for example. Improving the convenience to the caregiver by affording a full view, from every possible angle, of the occupant of the seating device while the protective cover is in place is important for reasons of safety, and peace of mind. Therefore, it is an object of this invention to provide a protective cover that overcome the afore mentioned hazards and that can be interchangeably affixed to a multiplicity of seating products and the like that affords improved visibility of the occupant by the caregiver from all angles including the top. [0035] The use of protective covers is becoming more wide spread as public awareness increases of the need to improve the well being of occupants and to protect occupants from the afore mentioned hazards and the like. In promotion of increased use of protective covers that improve the well being of occupants, it is therefore an object of this invention to provide a protective cover, which overcomes the afore mentioned hazards and that can be interchangeably affixed to a multiplicity of seating products and the like, which improves the caregiver's ease of use of the protective cover by affording ready access to the occupant without the need for removing the cover altogether and that affords a means of conveniently and compactly stowing the cover out of the way when not in use. [0036] Before mounting known protective cover configurations to the seating products, the cover material or fabric must be unfolded, turned right side out, or arranged prior to mounting to the seating product. Thus the caregiver is faced with the need to spend time to become familiar with the proper mounting position of the cover each time prior to mounting it to the seat. This costs time and can cause frustration. It is an object of this invention to improve the convenience to the caregiver by providing a protective cover that is self-erecting such that the protective cover is self-deploying into a final mountable configuration, effectively reducing the time required to deploy the protection cover so that the caregiver can rapidly mount the protective cover to the seating product with ease. [0037] Although known self supported ceiling protective covers configurations are comprised of ceiling support elements such as flexible rods, members, U-shaped arches, and canopies, storing these covers requires deliberate bending of the support element and folding of the unit into a compact form of the correct size and shape to fit into a storage compartment. In other cases, the compacting method is complicated, required that the user follow detailed instructions. These methods do not always yield the same results, and the user can end up with a bulky collapsed shape, a stored unit whose material or fabric is turned inside out, or a unit that requires re-assembly before attachment to the seating device, thereby requiring additional time and concentration to subsequently unfold and deploy for use. Therefore, it is an object of this invention to provide a protective cover that can be interchangeably affixed to a multiplicity of seating products and the like, which overcomes the afore mentioned hazards, and that can be rapidly and consistently collapsed into the same compact configuration every time, without disassembly of its basic parts, so that it can be stowed away for convenient transport by the caregiver and subsequently rapidly deployed in the same consistent manner every time. [0038] Known protective covers offer one or more flaps that can be used to protect against sun, rain, wind and the like. Known protective covers typically use flaps that are permanently attached to the covers and that pull back out of the way when not in use. These permanently affixed flaps represent bulk to the total assembly when not in use. For example, a flap for rain may not be required in a desert climate where sun is the primary concern for example. To get around this problem known protective covers are offered in different versions. This can result, for example, in a situation in which a care giver who desires to protect an infant with a protective cover, and is in a climate of more than one seasonal change may be required to purchase one protective cover to protect against sun, another against rain, and yet another against insects. In another scenario, a caregiver may wish to shield an infant from contact by strangers in public places, or to protect an infant from effects resulting from staring at overhead high intensity light sources, where rain protection would not be required. Accordingly, it is an object of this invention to provide a protective cover that can be interchangeably affixed to a multiplicity of seating products, which overcomes the afore mentioned hazards, and that provides a universal base configuration that is so constructed that it can, if necessary, be easily supplemented with rapidly attachable and removable protective layers, and whose supplementary layers can also be temporarily fastened out of the way in addition to being completely removed and stored such that a multiplicity of hazards can be addressed by one frame and one or more protective layers conveniently and compactly. [0039] Additionally, it is an object of this invention to provide a protective cover that overcomes the afore mentioned hazards, and which can be interchangeably affixed to a multiplicity of seating devices so as to provide as close as practically possible a one-type-fits all design, insofar as most seating devices such as strollers, carriages, infant seats and the like have fixed head and foot positions and that the protective cover herein disclosed is designed to span these head and foot positions, such that in one respect manufacturing costs are reduced corresponding to the reduction in variety of sizes offered, and as well in the reduction of types insofar as types are reduced by the use of supplementary protective layers. [0040] Additional objects and 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. SUMMARY OF INVENTION [0041] With these objects in view, according to an aspect of the present invention there is provided a collapsible cover for protecting an occupant in a seating unit having a head region and a foot region. The cover has a body comprised of a flexible material having a top portion and at least one side wall portion, the top portion having a generally ellipse shape and having a length to span the distance between the head region and foot region of the seating unit and a width to span the width of the seating unit. The sidewall portion is connected to the top portion along a substantial portion of the periphery of the top portion to provide an arched configuration to the top portion. The cover further has a single closed loop frame member made of a flexible, coil-able, resilient material, that is secured along the length of the structure's membrane body so as to assume an ellipse-like shape when viewed from above, that is bent into an arched configuration about its minor axis. The closed loop frame member is movable between an extended orientation to allow the cover to be attached to the seating unit and a collapsed orientation to allow for a reduced size of the cover for transport and storage and is connected to the periphery of the top portion to provide in the extended orientation an arched ellipse shape about the length of the top portion. The cover also has a means for releasably attaching the cover to a seating unit [0042] In an aspect of the invention, the sidewall portion is comprised of a pair of opposed side panel membranes of at least one layer of material, preferably formed into a semi circular-like shape, said side panel membranes being reinforced to prevent deformation of their semi circular-like shape, and to prevent relaxation of the arched configuration of the ceiling membrane. [0043] In another aspect of the invention the cover is provided with a frame sleeve formed either integrally into the top portion, or separately which adjoins the top portion to the sidewall portion, said frame sleeve holding the closed loop frame member. [0044] In yet another aspect of the invention, the cover is provided with a skirt connecting the opposing side panel membranes such that the skirt allows for releasable attachment of the cover to the seating unit by means of an elasticized hem such that the skirt may hug the peripheral of the seating product to provide a sealing action. [0045] In a further aspect of the invention, the cover is provided with at least one layer of supplemental cover membrane, in the approximate shape of the top portion, that can be attached to said top portion so as to provide at least one additional protective layer. This cover membrane as well as the top portion, may be comprised of conjoined types of membranes, that can provide protection from the elements. This cover membrane may also have side flaps permanently or temporarily affixed that may drape over the side panel membranes, be fastened temporarily so as not to flap about, afford further protection and may be similarly comprised of conjoined types of membrane. The entirety of the cover membrane and side panels may be stored when not in use by folding or rolling or removing completely from the membrane ceiling. [0046] In yet another aspect of the invention there is provided a collapsible cover for a seating unit having a frame member that may be formed from flexible, resilient material that can be coiled. In one embodiment of this invention the frame member is flat spring steel wire or equivalent that is comprised of materials or that is treated or encapsulated in some manner so as to resist corrosion. In another embodiment of this invention the frame member is a synthetic polymer, alloy of metal, composite material, or the like that has afore mentioned frame member properties. [0047] In yet another aspect of the invention there is provided a restraining element to retain the collapsed cover in its reduced-size coiled state with or without its supplemental cover membrane. Such restraining element can be a pouch or elastic or strap or clip to hold the cover in its reduced state. [0048] In another aspect of the invention, is the cover is adapted to be mounted on an infant seat such that the opposing ends are releasably held to the foot and head position of the infant seat by means of the previously described peripheral skirt, which can uninterruptedly surround the continuous perimeter of the infant seat so as to provide stable attachment of the cover frame member to the head and foot position of the infant seat. [0049] In another aspect of the invention, the cover is provided a stiffening means to aid in stably fastening and spacing the top portion above the seating unit. Preferably, the stiffening means is a U-shaped stiffener fastened to the frame member at the foot position and subsequently fastened by means of clips, straps or the like to the legs of the seating device. BRIEF DESCRIPTION OF THE DRAWINGS [0050] The invention will now be explained in detail with reference to the drawings, which [0051] In FIG. 1 shows the first embodiment of the protective cover mounted on an infant seat, [0052] In FIG. 2 shows a minimal configuration of the first embodiment, [0053] In FIG. 3 shows the first embodiment of the protective cover with the top opening closable by zipper, [0054] In FIG. 4 shows the first embodiment of the protective cover with the top opening closable by elasticized flap, [0055] In FIG. 5 a shows the second embodiment of the protective cover mounted on a three-wheel stroller, [0056] In FIG. 5 b shows the second embodiment of the protective cover with alternative stiffener fixing position, [0057] In FIGS. 6 a and 6 b shows one configuration of a stiffener, [0058] In FIG. 7 a shows the third embodiment of the protective cover mounted directly to the footrest position of a stroller, [0059] In FIG. 7 b shows the third embodiment of the protective cover mounted by means of stiffener, [0060] In FIG. 8 shows a method of adjusting the elasticized perimeter, [0061] In FIGS. 9 a and 9 b shows the connector for joining the frame member into a loop, [0062] In FIGS. 9 c and 9 d shows the connector for joining the frame member into a loop that also captivates the stiffener, [0063] In FIG. 9 e shows a means of temporarily captivating the stiffener while joining the frame member into a loop, [0064] In FIG. 10 a shows the frame sleeve arrangement, [0065] In FIG. 10 b shows an alternative frame sleeve deriving from the ceiling membrane, [0066] In FIGS. 11 a to 11 c shows a method of compacting the protective cover with a flat geometry frame member, [0067] In FIGS. 12 a to 12 d shows another method of compacting the protective with a round geometry frame member, [0068] In FIG. 13 shows the natural deployed configuration of the protective cover, [0069] In FIG. 14 shows an elasticized restraining element, [0070] In FIG. 15 shows a storage pocket, [0071] In FIG. 16 shows a storage pocket hanging on an infant seat, [0072] In FIG. 17 shows the cross ventilation features of the protective cover, [0073] In FIG. 18 shows the protective cover with side panel reinforcements and ceiling mounted activity strap, [0074] In FIG. 19 shows the lip at the perimeter of the frame sleeve for mounting covers, [0075] In FIG. 20 shows a supplementary cover mounted on the protective cover, [0076] In FIG. 21 shows a supplementary cover with side flaps mounted on a protective cover, In FIG. 22 a shows an alternative method of mounting the stiffener to the protective cover frame, [0077] In FIG. 22 b shows a detachable clamping means. DETAILED DESCRIPTION OF THE INVENTION [0078] As shown in the FIG. 1 to FIG. 22 , the present invention is directed towards a collapsible cover for protecting an occupant of a seating unit that satisfies the afore-mentioned objectives, of which three preferred embodiments are shown in FIGS. 1 a, 1 b, 1 c and select associated configurations and constituents are herein described. [0079] Referring to the drawings and embodiments of the invention herein illustrated, FIG. 1 illustrates a first embodiment of the protective cover of the present invention mounted on an infant seat with handle, FIG. 5 a illustrates a second embodiment of the protective cover of the present invention mounted on a three wheel stroller which utilizes a stiffener for attachment to the foot of the stroller, and FIG. 7 a illustrates a third embodiment of the protective cover of the present invention mounted on a four wheel stroller which fastens at the foot position directly. Examples of alternate seating products to which the protective cover of the present invention can be mounted are bouncy chair, shopping cart infant seat, swing chair, wheel chair and the like. Other seating products, afore mentioned, are equally applicable such as the umbrella stroller. Furthermore, it will be learned from practice of this invention that by simple modifications of dimensions such as the major axis of the ceiling, double strollers and the like can be accommodated. Tandem strollers can also utilize this invention by the use of two side-by-side protective covers and some minor mounting modification. Other seating products and applications to which the protective cover invention can be mounted will become obvious through the use of this invention. [0080] Turning to FIG. 1 , the first embodiment of the protective cover of the first embodiment is depicted, which is releasably attachable onto a multiplicity of infant seating products and the like to provide protection to an occupant of the seating unit. The protective cover is held into this arched shape by a frame member 3 which is connected to the top portion of ceiling membrane 2 by means of a frame sleeve 4 that is in turn connected to the sidewall, which in the first embodiment is coprised of a pair of reinforced semi-circle-like-shaped side panel membranes 5 . The cover is also aided in maintaining its arched shape in part due to its method of fixedly holding the head 6 a and foot 6 b of the frame member 3 to the seat by means of a elasticized skirt perimeter 7 or other such means as will be disclosed herein. As only the widths at the head position of the cover 6 a and at the foot position 6 b of the frame member 3 are in contact with the head 8 and foot 9 positions of the infant seating product, and as all such infant seating products and the like have corresponding head and foot positions, this arched shape is particularly suited to mounting on a multiplicity of infant seating products. The skirt perimeter 7 secures the head 6 a and foot 6 b of the frame member 3 to the seat by means of a cord, elasticized element, drawstring or the like, which can be integral to the skirt perimeter 7 or encapsulated within a sleeve at skirt perimeter 7 to simultaneously provide a sealing function around the perimeter of the seat. [0081] FIG. 2 illustrates a minimal configuration of the first embodiment, which has a top opening to allow for access to the occupant of the seat. In the embodiment of FIG. 1 , two top openings 11 are provided with a center web therebetween to help in maintaining stability which is further enhanced by means of reinforced side panel membranes. In the preferred embodiment, FIG. 3 illustrates an example of a top opening 13 , which is closable by means of zipper flap 14 and optionally tied back by means of a tie 15 or other such methods as is known to those familiar with the art. In another embodiment, FIG. 4 shows the top opening 13 closable by means of elasticized flap 16 and secured from inadvertent removal by means of button or snap 17 at the head 6 a and foot 6 b. The ability to open the cover wide enough to allow access to the occupant of the protective cover is afforded by the large minor axis, or width of the elliptically shaped ceiling membrane, due in part to the frame member loop geometry forming the ceiling membrane, and in part due to the reinforced side panel membranes. The advantage of openings in the ceiling membrane is that the caregiver is not required to remove the protective cover from its mounted position on the seat in order to access the occupant. [0082] Turning to FIG. 5 a, the second embodiment illustrates a protective cover 1 b that fits on a multiplicity of carriages, here shown on a three-wheel stroller 10 . Similar to the first embodiment, the cover is held in its arched shape, in part due to the arched shape of a frame member 3 which is connected to the ceiling membrane 2 by means of a frame sleeve 4 that is in turn connected a pair of reinforced semi-circle-like-shaped side panel membranes 5 , and in part due to its connection to the head 6 a and foot 6 b of the frame member 3 to the carriage by means of a stiffener 20 and clamping means 21 at the foot position 9 of the stroller and an elasticized strap 19 to the carriage at the head position 8 , or by other such means as will be discussed herein. As only the head 6 a and foot 6 b of the frame member 3 are fastened to the carriage head position 8 and carriage foot position 9 , and as all stroller or carriages have corresponding head and foot positions, this arched shape is particularly suited to mounting on a multiplicity of carriage types. [0083] In this embodiment, a stiffener 20 and clamping means 21 secure the foot 6 b of the frame member 3 to the stroller or carriage foot position 9 at the wheel posts 22 of the stroller, thereby providing a rigid connection. The use of a stiffener also provides a clearance for the feet of the occupant. The clamping means 21 is to eliminate axial rotation of the stiffener 20 about the wheel posts, and can be comprised of strapping, clips, clamps, or other fasteners that provide appropriately secure connection of the stiffener 20 to the wheel posts 22 . Although not shown here, a permanent bracket may also be affixed to the wheel post in order to captivate the stiffener and achieve a clamping means as effective as others. FIG. 5 b illustrates an alternative fixing method of stiffener 20 directly to the quick release wheel fasteners 21 , which could alternately be permanently affixed thereto and the stiffener 20 detached from the frame member by means described herein in FIG. 9 e. [0084] In another example, one stiffener is used on either side of the stroller cover lengths as illustrated in FIG. 22 a. The stiffener 20 can be permanently or detachably attached to the frame member 3 by a clip or snap 17 or other such means as is known to those familiar with the art as long as the stiffener 20 is prevented from rotating about the frame member 3 . The stiffener 20 is also prevented from rotating axially about the wheel posts 22 by a clamping means 21 . [0085] It can also be seen in FIG. 22 b that the stiffener 20 angle A to the wheel posts 22 and the clamping means 21 can be adjustable and is tightened to the desired angle by a fastening means 46 , in this case a wing nut type compressive nut fastener, but other types of fasteners can be employed. Adjusting the angle of the stiffener in the direction parallel to the wheel posts and clamping means can also be achieved by numerous methods that are apparent to those familiar with the practice. Furthermore, adjustment of the angle of the stiffener in the direction parallel to the wheel posts is not necessary in applications where the stiffener angle will be known in all cases. In this case the clamping means 21 is depicted as a removable and adjustable spring element that accommodates various wheel post diameters and profiles. Although not shown here, a permanent bracket may also be affixed to the wheel post in order to capture the stiffener and achieve a clamping means as effective as others. In addition, although the stiffener is depicted as a wire shaped rigid member, its geometry can vary as long as the geometry achieves the object of providing stable fixation of the frame member to the carriage. [0086] As can be appreciated by the forgoing descriptions, a myriad of possible fastening configurations of the frame member to the carriage or seat product at the foot, head or perimeter positions are possible and shall not be limited to the descriptions herein nor shall these methods detract or in any manner nor limit the scope or novelty of the invention disclosed. [0087] With reference to FIG. 6 a and FIG. 6 b an example of one configuration of a stiffener 20 is represented which is made of a material sufficiently ridge yet flexible enough to resist deformation such as spring steel, composite, fiberglass or polymer or the like, and such that the W dimension can conform to the average width of a seating device. This W dimension should be approximately the same as the D dimension of the coiled configuration described in FIGS. 11 c or FIG. 12 d in order to accommodate storage. Accordingly, the X dimension can be less than or equal to the W dimension. [0088] In the third embodiment shown in FIG. 7 a the overall protective cover is longer along its major axis and the stiffener 20 is not used, allowing the cover to be connected directly to the footrest position 14 of the four wheel carriage by a clamping means such as strapping, hook and loop fasteners, clips, clamps or others as is commonly know to those familiar with the art. FIG. 7 b depicts the third embodiment, which utilizes stiffener 20 and clamping means 21 that is attached to the wheel posts 22 . [0089] Referring to FIG. 5 a, the head 6 a of the frame member 3 is secured to the carriage head position 8 by means of an elasticized strap 19 . This elasticized strap 19 can be easily slid around the carriage pusher posts 26 thereby effectively clamping the head 6 a of the frame member 3 against the carriage pusher posts 26 . A friction padding 27 made of rubberized material or the like can be effectively employed along an appropriate length of the head 6 a in order to minimize slippage of the frame member 3 against the pusher posts 26 . The elasticized strap 19 can be permanently stitched to the head 6 a of the frame member 3 or fastened by means of a snap or button 17 or other such method as is common to those familiar with the art. The elasticized strap 19 can be replaced by an adjustable webbing material, cording, tube clips, clamps or other such means that achieves the desired clamping effect. Although not depicted, these features are equally applicable to embodiment second as to the third embodiment. [0090] In the second and third embodiments an adjustable elasticized perimeter 28 , depicted in FIG. 8 is employed to seal the lower skirt portion of the side panel membranes 5 around the perimeter of the carriage. FIG. 8 depicts the rear portion of the carriage where the elasticized perimeter 28 is joined by means of loop and button 29 such that the elasticized perimeter 28 becomes continuous and can be tightened to increase the sealing effect by means of cord grips 30 or other such means of fastening and tightening as is familiar to those in the art. Furthermore, because the side panel membranes 5 are elasticized at the perimeter, access to the occupant is readily possible from these side panels by simply lifting the panels 5 up, or by loosening the elasticized perimeter 28 and lifting the side panels 5 . Alternative adjustment methods can be employed. [0091] FIG. 9 a and FIG. 9 b depicts a perferred embodiment of the frame member wherein a connector 31 is utilized to join the ends of the frame member 3 such that it forms a continuous loop. The connector 31 is comprised of a shaped sheet material, preferably a corrosion resistant metal such as galvanized mild steel, which is crimped with a sufficient force to prevent disconnection of the frame member ends. In FIG. 9 c and FIG. 9 d the stiffener 20 is included in the crimped connector arrangement. In FIG. 9 e an alternate system of temporarily capturing the stiffener is illustrated, where the frame member 3 is inserted and crimped into the rectangular bore end, and the stiffener 20 is removable and re-attachable at the open clip end. Alternative methods of connecting frame members of other cross sections and of joining the ends are possible as are known to those familiar with the art. [0092] In the preferred embodiment, the frame member 3 is comprised of a flat flexible member per FIG. 10 a, preferably made of a blue tempered spring steel material, which is protected from corrosion resistance. A frame sleeve 4 per FIG. 10 a can encapsulate the frame member 3 and be sewn along the semi-circular like arc of the side panel membranes 5 . Alternatively in FIG. 10 b the frame member 3 can be sewn into the ceiling membrane 2 such that the ceiling membrane forms a frame sleeve 4 , which encapsulates the frame member 3 . Other methods known to those familiar with the art are also possible. [0093] In the preferred embodiment the frame sleeve 4 is comprised of durable material capable of resisting the abrasion that will be experience from containing hard frame member 3 elements, as well as daily wear and tear. [0094] The rigidity as well as the coil-ability of the frame member 3 is a function of the member's cross sectional geometry, its material properties, and the length of frame member 3 used in a particular geometry and size of the closed loop assembly. This configuration of the frame member, combined with the relatively small size of the protective cover assembly, takes advantage of these properties by training the single loop frame member 3 into an arched shape geometry such that the head 6 a and foot 6 b tend to automatically move toward each other from the natural deployed configuration when the opposing frame member lengths 32 are pushed toward each other per FIG. 11 a. FIG. 11 b shows the intermediate position prior to the final compact coil depicted in FIG. 11 c. This tendency of the protective cover to coil easily due to the training geometry is referred to as the pre-coil geometry, and is the geometry defined as the open deployed position of FIG. 13 . [0095] Prior art devices utilizing continuous loop frame members typically train the user to collapse the product by including instructions containing multiple steps which come as a separate document or are attached to a tagging. Because the pre-coil geometry of the present invention facilitates simple collapsing of the stroller cover frame member, collapsing requires no training of the user when simple instructions are affixed to the cover at the points along the frame member lengths 32 that will result in collapse of the cover. These instructions need only convey the message “push here to compact”, thereby eliminating any training whatsoever on the collapse of the cover. Such instructional arrows 47 are shown affixed to the cover in FIG. 11 a. [0096] In another embodiment of this invention, the frame member 3 is comprised of a somewhat rounder cross section flexible member per FIG. 10 b, which requires the deployed unit to be collapsed by means described in FIG. 12 a to FIG. 12 d. To collapse the deployed protective cover, opposing frame member lengths 32 are brought close to one another per FIG. 12 a. Once close, they are twisted to form a figure eight shape per FIG. 12 b. The figure eight shape is then folded per FIG. 12 c to form two coincident circles per FIG. 12 d. [0097] Due to the stored spring force of the frame member 3 portion of the cover in the coiled configuration per FIG. 11 c or FIG. 12 d, when released, the cover seeks its natural deployed configuration per FIG. 13 , thereby self-erecting in a manner most convenient as fussing and untangling of the cover from its collapsed position is eliminated from the process of deploying the protective cover of the present invention. [0098] When in the coiled configuration depicted in FIG. 11 c or FIG. 12 d, the cover will tend to self-deploy into the deployed configuration per FIG. 13 under the spring force of the frame member 3 unless secured in the coiled configuration by means of an elasticized restraining element 33 depicted in FIG. 14 . The restraining element 33 can alternatively be comprised of a hook and loop material, a strap that fastens by means of fasteners, or by a storage pocket 34 such as that depicted in FIG. 15 or other such means used by those familiar with the art. The restraining elements can be integrally attached to the assembly, or detachable and can be made of membrane such as fabric or leather, or synthetics. This storage pocket 34 can be equipped with a carrying strap or fastening strap 35 for convenient attachment and carrying as required as depicted on an infant seat in FIG. 16 , and can be fastened likewise on other forms. [0099] With the cover mounted on an infant seat per FIG. 18 , the cover provides a natural canopy that keeps the ceiling membrane away from the face of the occupant due to a arched shape, which is maintained in this shape by the use of a pair of semi-circular like shaped side panel membranes 5 which includes reinforcements 36 a and 36 b to maintain the arched shape of the frame member 3 . The reinforcements can be integrally sewn, woven, fused or encapsulated into the side panels at fixed length and therefore at a fixed ceiling height, or the membrane of the side panels 5 can be comprised of non-stretching material. Alternatively, in order to allow for increased arch shape, resulting in greater ceiling clearance from the occupant, the reinforcement 36 a can be adjustable in length per FIG. 18 by means of a cord grip 30 and cord 37 or other such means known to those familiar with the art. Due to the elliptical shape of the ceiling panel, and the tendency for the frame member loop to seek its relaxed round loop geometry, the arched geometry will be unstable at the opposing length 32 quadrants where the minor axis of the ceiling panel ellipse shape intersects the frame member loop. This is because in the arched geometry the frame member loop is twisted out of its relaxed circular geometry, causing the loop to tend to twist in on its self to seek its relaxed loop geometry. Therefore, reinforcement 36 b is employed, which effectively constrains the frame member loop from finding its relaxed position. Reinforcement 36 b is particularly effective to prevent the arch from being lost during collapsing by preventing the frame member loop from turning itself inside out when the two opposing lengths are pushed together. [0100] The semi-circular shape of the side panel membranes 5 provide elevated side vents that have broad cross sectional areas thereby creating large cross ventilation surfaces for viewing as shown by the arrows in FIG. 17 when the side panel membranes 5 are made of transparent ventilating materials such as mesh fabric, screen fabric, or perforated material which simultaneously affords visibility. Furthermore, it can be seen that the deployed arched shape provides a large internal space for the occupant, which, combined with the visibility afforded through the large side panels, thereby reduces the potential for feelings of confinement by the occupant. Another benefit is that the caregiver can view the occupant of the cover from both sides. [0101] Another benefit of the arched rigid ceiling shape is that the perimeter of the ceiling which is defined by the frame member 3 , the frame sleeve 4 , the ceiling membrane 2 , and the reinforced side panel membranes 5 , creates a lip 38 per FIG. 19 which forms a rigid narrow perimeter around the ceiling membrane. The advantage of this lip 38 around the perimeter of the ceiling is its particular amenability to securely fastening easily mountable supplementary covers 39 that have elasticized perimeters 40 per FIG. 20 , where the first embodiment is shown, although covers can be similarly employed on other embodiments. This lip 38 , can not only be used to secure a cover which encapsulates the ceiling membrane 2 , but can also be used to secure a portion of the cover out of the range of view 41 when the cover is fastened intermediately to the ceiling membrane 2 by means of snaps or buttons 17 with reference to FIG. 20 . [0102] In the preferred embodiment the ceiling membrane 2 and side panel membranes are comprised of one layer of mesh fabric, screen fabric, or perforated material, or a combination of fabrics that afford visibility and ventilation. As the ceiling membrane 2 allows air flow in a similar way that the side panel membranes 5 allow air flow, the environment protection afforded by the ceiling membrane and side panels relates to protecting the occupant from insects, UV radiation, aerosol germs, contact by strangers and limited wind resistance. Another benefit to the use of ceiling and side panel membrane material that affords visibility and ventilation in the preferred embodiment is the effect of reducing the probability of feelings of confinement to the occupant. Yet another benefit of visibility is that the caregiver can view the occupant from all top and side angles. [0103] In the first embodiment insects are significantly discouraged from entering the enclosure due to the skirt perimeter 7 that seals around seat. the second and third embodiments, although discouraging insects by significantly encapsulating the occupant, can have enhanced insect protection with the addition of a wrap under insect netting, which completely encapsulates the occupant for environments where biting insects are a concern. The insect netting can be detachable by means of zipper, Velcro, snaps or other such method as is known to those familiar with the art. The insect netting can be comprised of a perforated material, or a combination of materials, or be impregnated with safe insect repellent elements, which prevent or further discourages insects from entering or approaching the protective cover. [0104] In the preferred embodiments, the ceiling and side panel membranes have a UV protective quality, in a similar manner in which a perforated shade cloth would provide UV protection. This can be achieved by various methods including the use of light absorbent colors, light reflective materials, composite materials, polarizing materials and the like. [0105] In the preferred embodiments the supplementary covers 39 will afford additional environmental protection against rain, direct sunlight, strong wind, air pollution and cold. For example, a supplementary cover to protect against rain can be comprised of transparent rain blocking material such as PVC, Mylar™, or a combination of materials to achieve similar effects. A supplementary cover to provide additional protection from UV radiation can be comprised of polarized fabric, shade cloth and the like. In another example a supplementary cover to provide protection from cold weather can be comprised of insulating material or heat reflective membrane, or fabrics such as Thinsulate™. In yet another example a supplemental cover designed to prevent the ingress of pollution can include filtration such as fabric encapsulates or is impregnated with activated carbon and the like. [0106] In one embodiment FIG. 21 depicts a supplementary cover 39 , which employs side panel flaps 42 to afford additional side panel protection from extreme environmental influences, whilst affording ventilation by inherent perforations, or by under sizing the flap to allow gaps 43 in the side panel membrane of sufficient size for air to pass through. Snaps 17 are indicated to enable the side panel flaps 42 to be detachable. [0107] As fabric technologies advance, the need for supplementary covers may diminish and the ceiling membrane 2 and side panel membranes 5 may be comprised of material or layering of composite material such that the final result, when used in conjunction with the frame geometry disclosed herein provides simultaneously protection from environmental effects whilst affording proper ventilation and visibility. Such materials are emerging in the market place. [0108] FIG. 18 depicts an activity strap 44 with removable loops of strapping 45 to which various soft toys or light weight objects, or even a soother or bottle can be fastened by independent means so as to entertain the infant or to secure favored objects within arms length of the infant. Furthermore, the ceiling can be decorated with photo luminescent shapes such as stars, or pictures and the like for the entertainment of the occupant. These features are equally applicable to carriage applications. [0109] The preferred embodiment of this invention is comprised of a base unit that may have one or more supplemental cover membranes. The base unit is covered with a single layer of ceiling membrane and a single layer of opposing side panel membranes such that these layers are comprised of a mesh fabric, perforated fabric, screen or the like, which affords ventilation and which is transparent enough to afford an adequate view from within and without. This enables viewing of the infant from all angles, panoramic view from within and ventilation from all sides. In short the membrane fabric may have transparency, ventilation properties, insect repellent properties, particulate filter properties, and shading properties. Breathable fabrics may also afford additional rain repellent properties. These types of fabrics may be conjoined fabrics, materials, or composites formed in various ways to afford application specific protective functionality. [0110] As discussed, the base unit may be supplemented with easily mountable covers, which enhance and extend the range of possible applications, and may be comprised similarly of conjoined fabrics, materials, or composites formed in various ways to afford application specific protective functionality. [0111] While the preferred embodiments of the present invention have been described, it should be understood that various changes, adaptations and modifications might be made thereto without departing from the spirit of the invention and the scope of the appended claims. It should be understood, therefore, that the invention is not to be limited to minor details of the illustrated invention shown in the figures and that variations in such minor details will be apparent to one skilled in the art. [0112] Therefore it is to be understood that the present disclosure and embodiment of this invention described herein are for the purposes of illustration and example and that modifications and improvements may be made thereto without departing from the spirit of the invention or form the scope of the claims. The claims, therefore, are to be accorded a range of equivalents commensurate in scope with the advances made over the art.

The present invention is directed to a collapsible cover for protecting an occupant in a seating unit having a head region and a foot region. The cover has a body comprised of a flexible material having a top portion and at least one side wall portion, the top portion having a generally ellipse shape and having a length to span the distance between the head region and foot region of the seating unit and a width to span the width of the seating unit. The sidewall portion is connected to the top portion along a substantial portion of the periphery of the top portion to provide an arched configuration to the top portion. The cover further has a single closed loop frame member made of a flexible, coil-able, resilient material, that is secured along the length of the structure's membrane body so as to assume an ellipse-like shape when viewed from above, that is bent into an arched configuration about its minor axis. The closed loop frame member is movable between an extended orientation to allow the cover to be attached to the seating unit and a collapsed orientation to allow for a reduced size of the cover for transport and storage and is connected to the periphery of the top portion to provide in the extended orientation an arched ellipse shape about the length of the top portion. The cover also has a means for releasably attaching the cover to a seating unit

RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 11/115,983, filed Apr. 27, 2005, now allowed, which application is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to treatment of cancer related pain and constipation. Preferably the subject in need is administered a combination of the cannabinoids cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). More preferably the cannabinoids are in a predefined ratio by weight of approximately 1:1 of CBD to THC. BACKGROUND OF THE INVENTION [0003] Pain, in particular chronic pain, can be a severely debilitating problem for many patients and it is often the case that the disease that is causing the pain itself becomes untreatable and the main focus of care is then altered to be palliative. [0004] Even though the doctors and care providers best intentions are to provide optimum care for the patient, pain and symptom control can often not be as effective as hoped as the entire healthcare system has been designed to cure disease rather than alleviate pain and symptoms. [0005] Effectively treating chronic pain poses a great challenge for doctors and health care providers as this type of pain often affects a patient's quality of life. A person's ability to carry out everyday tasks can be severely compromised due to chronic pain and as such the patient's personality can change. [0006] For example when a patient is suffering from chronic pain caused by terminal cancer the only treatment option available is the relief of pain. Unfortunately up to 40% of cancer sufferers have unmet needs in pain suppression at the present time. [0007] The caregiver's requirements are to provide the patient with a sufficient dose of medication to allow them to be freed as far as possible from their pain but there are inherent problems with this. [0008] Often with the use of opiate related drugs the increased dosages of these drugs administered result in the patient becoming drowsy and unresponsive. Increased dosages of these medicaments can also cause respiratory failure and in consequence may result in premature death. [0009] Physicians and nurses are often reluctant to give large doses of analgesic drugs, even to dying patients. Their fear is that the large doses provided will lead to sedation or respiratory depression. The result of this can be that the patient's pain is not adequately catered for. [0010] In a position statement on treatment of pain at the end of life, the American Pain Society has recognised that terminal illness can often be accompanied by pain that is so severe that death can seem preferable. It has also been recognised that a substantial proportion of patients, particularly those in minority groups, are receiving inadequate analgesic treatment (Cleeland et al., 1994). [0011] The American Pain Society has recommended that pain is made more visible and is therefore routinely charted as the fifth vital sign. [0012] The use of cannabis as a medicine has long been known and during the 19 th Century preparations of cannabis were recommended as a hypnotic sedative which were useful for the treatment of hysteria, delirium, epilepsy, nervous insomnia, migraine, pain and dysmenorrhoea. [0013] Until recent times the administration of cannabis to a patient could only be achieved by preparation of cannabis by decoction in ethanol, which could then be swallowed or by the patient inhaling the vapours of cannabis by smoking the dried plant material. Recent methods have sought to find new ways to deliver cannabinoids to a patient including those which bypass the stomach and the associated first pass effect of the liver which can remove up to 90% of the active ingested dose and avoid the patient having to inhale unhealthy tars and associated carcinogens into their lungs. [0014] Such dosage forms include administering the cannabinoids to the sublingual or buccal mucosae, inhalation of a cannabinoid vapour by vaporisation or nebulisation, enemas or solid dosage forms such as gels, capsules, tablets, pastilles and lozenges. [0015] In 1988 a study was undertaken in order to determine the analgesic and anti-inflammatory activity of various cannabinoids and cannabinoid pre-cursors. Oral administration of CBD was found to be the most effective at inhibition of PBQ-induced writhing in mice. THC and CBN were found to be least effective at reducing analgesia and inflammation (Formukong et al., 1988). [0016] Holdcroft et al. have shown that cannabinoids can have analgesic and possible anti-inflammatory properties. Administration of 50 mg of THC to a patient with Mediterranean fever resulted in a highly significant reduction in the amount of analgesia that the patient required (Holdcroft et al., 1997a). [0017] A follow-on publication by the same authors examined the oral administration of oil of cannabis . The capsules containing 5.75% THC, 4.73% CBD and 2.42% CBN were administered to a patient with familial Mediterranean fever. During the 3 weeks of active treatment there was a decrease in the amount of escape medication (morphine) required by the patient (Holdcroft et al., 1997b). There were no changes in the measured inflammatory markers. [0018] The use of different ratios of cannabinoids such as THC or CBD or their propyl variants, tetrahydrocannabinovarin (THCV) and cannabidivarin (CBDV), in the treatment of different diseases and conditions has previously been described in co-owned UK patent application GB2377633. [0019] Specific ratios of THC and CBD or THCV and CBDV were reported to have been useful in the treatment or management of specific diseases or medical conditions. The following table details some of these areas. [0000] Product Group Area Ratio THC:CBD Target Therapeutic High THC >95:5  Cancer pain; Migraine; Appetite stimulation. Even ratio 50:50 Multiple sclerosis; Spinal cord injury; Peripheral neuropathy; Neurogenic pain. Broad ratio CBD <25:75  Rheumatoid arthritis; inflammatory bowel disease. High CBD <5:95 Psychotic disorders (schizophrenia); Epilepsy; Movement disorders; Stroke; Head injury; Disease modification in rheumatoid arthritis and other inflammatory conditions; Appetite suppression. [0020] A major disadvantage with the currently available drug therapies to treat severe chronic pain can be that the use of opioid based drugs may lead to unwanted side effects including constipation, sedation, pruritis, nausea and vomiting, respiratory depression, dysphoria and hallucinations and urinary retention. SUMMARY OF THE INVENTION [0021] The use of a high THC extract has long been postulated to be an effective treatment of pain, especially in the treatment of pain caused by cancer. [0022] Surprisingly, the applicants have found that the use of a cannabis based medicine extract that contains approximately equal amounts of the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) is more efficacious in the treatment of cancer pain than a cannabis based medicinal extract containing THC alone. [0023] The applicants have also found, unexpectedly, that some of the unwanted side effects caused by opiates such as constipation are relieved by treatment with the combination of the cannabinoids CBD and THC. [0024] According to the first aspect of the present invention there is provided a method of treatment of cancer related pain comprising administering to a subject in need thereof a combination of the cannabinoids cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), wherein the ratio of CBD:THC by weight is between 10:1 and 1:10. [0025] Preferably the ratio of CBD:THC by weight is between 5:1 and 1:5. More preferably the ratio of CBD:THC by weight is between 2:1 and 1:2. More preferably the ratio of CBD:THC by weight is between about 1:0.9 and 0.9:1, still more preferably the ratio of CBD:THC by weight is about 1:1, and yet more preferably the ratio of CBD:THC by weight is 0.93:1. [0026] Preferably the method comprises the treatment of cancer related pain which is caused by cancer of the breast; cancer of the prostate; cancer of the lung; cancer of the cervix; cancer of the rectum; cancer of the stomach; or cancer of the colon. [0027] Preferably the dose of medicament to be administered to the subject suffering from cancer related pain is formulated such that a patient is able to titrate their dose. Examples of titratable dosage forms are gel, gel spray, liquid and vapor. [0028] The term “titrate” is defined as meaning that the patient is provided with a medication that is in such a form that smaller doses than the unit dose can be taken. [0029] A “unit dose” is herein defined as a maximum dose of medication that can be taken at any one time or within a specified dosage period such as 3 hours. [0030] Titration of doses are beneficial to the patient as they are able to take smaller doses of the medication to achieve efficacy. It is understandable that not all patients will require exactly the same dose of medication, for example patients of a larger build or faster metabolism may require a higher dose than that required by a patient that is of a smaller build or slower metabolism. Different patients may also present with different degrees of complaints (e.g., cancer-related pain) and as such may require larger or smaller doses in order to treat the complaints (e.g., cancer-related pain) effectively. The benefits of such a dosage form over dosage forms such as tablets, where smaller doses are difficult to take, are therefore evident. [0031] Unit dose ranges are preferably in the range of between 5 and 25 mg of each cannabinoid CBD and THC, more preferably in the range of 10 to 20 mg of each cannabinoid, more preferably in the range of 12 to 14 mg of each cannabinoid more preferably still in the range of 12.5 to 13.5 mg of each cannabinoid. [0032] Preferably the maximum daily dosage dose of medicament to be administered to the subject suffering from cancer related pain is less than or equal to 120 mg CBD and less than or equal to 130 mg THC. [0033] A combination of cannabinoids such as THC and CBD to a patient can be administered at the same time, for example wherein the cannabinoids are contained in the same formulation. The cannabinoids also can be administered at separate times. For example, a formulation containing CBD could be administered to a patient at a fixed time prior to a formulation containing THC in order to ameliorate some of the side effects of THC, which CBD is known to improve or vice versa. The two cannabinoids could also be administered consecutively to a patient if required. [0034] A further embodiment of the invention provides a method of treatment of cancer related pain whereby a combination of the cannabinoids CBD and THC are packaged for delivery such that delivery is targeted to a specific area such as a sublingual area; a buccal area; an oral area; a rectal area; a nasal area; and/or via the pulmonary system. Preferably the cannabinoids are packaged for delivery sublingually or buccally, more preferably as a sublingual or buccal spray. [0035] Preferably the cannabinoids are one of the following forms: gel; gel spray; tablet; liquid; capsule or a form for vaporisation. [0036] Additionally the pharmaceutical formulation preferably further comprises one or more carrier solvents. Preferably the carrier solvents are ethanol and/or propylene glycol. More preferably the ratio of ethanol to propylene glycol is between 4:1 and 1:4. More preferably still the ratio is substantially 1:1. [0037] Pharmaceutical formulations are prepared using methods and compositions known to those skilled in the art. Preferred components of suitable formulations are provided, for example, in US published applications US 2004/0034108, US 2003/0021752 and US 2002/0136752, and PCT published applications WO 2004/016246 and WO 02/064109. [0038] Preferably the invention provides a combination of cannabinoids, which are present as one or more cannabis based medicine extracts (CBME). In one embodiment the CBME are produced by extraction with supercritical or subcritical CO 2 . In an alternative embodiment the CBME are produced by extraction from plant material by volatilisation with a heated gas. Preferably the CBME contain all of the naturally occurring cannabinoids in the plant material. Alternatively synthetic or highly purified isolates of the cannabinoids can be used. [0039] More preferably the method of treatment of cancer related pain comprises a combination of cannabinoids which are: a cannabis based medicinal extract which comprises THC at more than 90% of the total cannabinoid content in the extract; and a cannabis based medicinal extract which comprises CBD at more than 90% of the total cannabinoid content in the extract. [0040] In a further embodiment of the invention the treatment of cancer related pain additionally comprises administration of the cannabinoids CBD and THC in an approximately equal amount by weight in combination with one or more opiate or opiate related drugs. An alternative embodiment of the invention comprises the administration of the cannabinoids CBD and THC in an approximately equal amount by weight in addition to one or more opiate or opiate related drugs. [0041] The term “approximately equal” is used to refer to ratios of cannabinoids which are in the range of between 0.9:1 to 1:0.9 (THC:CBD). Additionally the term “1:1” is taken herein to refer to approximately equal amounts of cannabinoids. [0042] Opiate or opiate related drugs include but are not limited to morphine, drugs chemically related to morphine and also non-related structures which act at the same receptors in the brain. [0043] The term “in combination” refers to administration of the cannabinoids at the same time and in the same formulation as the opiate or opiate related drug. [0044] The term “in addition to” refers to administration of the cannabinoids to patient who is already being administered opiate or opiate related drugs. [0045] According to a second aspect of the present invention there is provided a method of treatment of constipation comprising administering to a subject in need thereof a combination of the cannabinoids cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), wherein the ratio of CBD:THC by weight is between 10:1 and 1:10. [0046] Preferably the constipation is associated with opiate or opiate related drug therapy. [0047] The methods of constipation treatment include the cannabinoid compositions, dosage forms, modes of delivery, etc. as described above in relation to the methods of treatment of cancer related pain. [0048] Certain aspects of this invention are further described, by way of example only, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0049] FIG. 1 shows an HPLC chromatographic profile which characterises a CBD-containing cannabis based medicine extract. [0050] FIG. 2 shows an HPLC chromatographic profile which characterises a THC-containing cannabis based medicine extract. [0051] FIG. 3 shows an HPLC chromatographic profile which characterises a cannabis based medicine extract comprising substantially equal quantities of CBD and THC. DETAILED DESCRIPTION OF THE INVENTION [0052] A cannabis based medicine extract (CBME) was prepared as outlined in Example 1 and contained approximately equal amounts of the cannabinoids THC and CBD and this was administered to patients with cancer related pain. [0053] A double blind, randomised, parallel group, placebo-controlled, comparative study of the efficacy, safety and tolerability of different cannabis based medicine extracts (CBME) was undertaken. The test articles that were studied were CBME THC:CBD (1:1) (THC 27 mg/ml), (CBD 25 mg/ml); CBME THC (THC 27 mg/ml); and matching placebo. [0054] The study population were patients who were hospice or hospital in or outpatients, aged 18 years or above, who had terminal cancer and were experiencing pain that was not responding adequately to strong opiate or opiate related therapy. [0055] The aim of the study was to determine whether the administration of either the combined THC and CBD or THC alone could be used to relieve pain in patients with cancer related pain. [0056] The primary outcome of the study was to compare each CBME versus the placebo in the change from baseline in the patient's pain score at visit 3. The use of escape analgesia was also measured as a co-primary end-point of the study. [0057] The secondary objectives of the study were to the use of regular maintenance medication, the dose of study medication and also whether there was a change from baseline in sleep disturbance, nausea, memory, appetite, concentration, Brief Pain Inventory (BPI) scores and quality of life compared to placebo. [0058] Unexpectedly the cannabis based medicine extract containing approximately equal quantities of THC and CBD produced a greater degree of pain relief than the CBME that contained THC alone. [0059] Additionally patients that were administered the CBME containing approximately equal amounts of THC and CBD reported in their quality of life questionnaire a lesser degree of constipation in comparison to their baseline scores at the beginning of the trial. [0060] The features of the invention are illustrated further by reference to the following examples: Example 1 Preparation of Cannabis Based Medicine Extracts (CBME) [0061] Medicinal cannabis was produced and prepared with reference to the method disclosed in WO 02/064109 (Example 15). The resulting plant material was processed as described in the flow chart below. The process of manufacture of a High THC or High CBD cannabis based medicine extract is described. [0000] [0062] The resulting extract is referred to as a cannabis based medicinal drug extract and is also classified as a Botanical Drug Substance according to the US Food and Drug Administration Guidance for Industry Botanical Drug Products. [0063] The quantity of cannabinoid in the CBME can be accurately assessed by way of measurement by HPLC with reference to the method disclosed in WO 02/064109 (Example 16). [0064] An example of an HPLC chromatogram of a CBD-containing CBME produced using a high CBD medicinal cannabis plant extracted with CO 2 is shown in FIG. 1 . An example of an HPLC chromatogram of a THC-containing CBME produced using a high THC medicinal cannabis plant extracted with CO 2 is shown in FIG. 2 . An example of an HPLC chromatogram containing the relevant ratios of THC and CBD CBMEs is shown in FIG. 3 . Example 2 Assessment and Comparison of the Efficacy, Safety and Tolerabilty of Cannabis Based Medicine Extracts by Way of a Clinical Trial in Human Patients with Cancer Related Pain [0065] A multi-centre, double blind, randomised, parallel group, placebo controlled, comparative study was undertaken in order to evaluate the efficacy, safety and tolerability of cannabis based medicine extracts (CBME) in patients with cancer related pain. The cannabis based medicine extracts contained either delta-9-tetrahydrocannabinol (THC) at a concentration of 27 mg/ml and cannabidiol (CBD) at a concentration of 25 mg/ml in ethanol:propylene glycol (50:50) excipient or delta-9-tetrahydrocannabinol (THC) at a concentration of 27 mg/ml in ethanol:propylene glycol (50:50) excipient. The CBME was presented in a pump action spray where each activation delivers 100 μl of spray, containing THC (2.7 mg) and CBD (2.5 mg). [0066] The subjects in the study were randomised equally to either one of the cannabis based medicine extracts or placebo. The placebo matched the appearance, smell and taste of the active formulation, but containing no active components. The excipient was ethanol:propylene glycol (50:50). Again the placebo was presented in a pump action spray where each activation delivers 100 μl of spray. [0067] Patient Diary Cards were required to be completed daily throughout the study. The patient could take strong opioid escape medication at any time throughout the study although other analgesic medications were required to be kept constant. [0068] The maximum dose of study medication that was allowed to be taken was 8 sprays at any one time or within any 3 hour interval, with a maximum of 48 sprays within any 24 hour interval. [0069] Patients were randomised to receive either THC:CBD (1:1), THC or placebo. The randomisation was in the ratio of 1:1:1 (THC:CBD (1:1), THC, Placebo). [0070] It should be noted that the terms 1:1 THC:CBD or equal amounts of THC:CBD refer to approximately equal. [0071] At the screening visit the patients were assessed for compliance with the inclusion or exclusion criteria and advised of the study requirements. Once the patient had provided informed consent, eligible patients were asked to complete run-in diaries for a period of 2 days before returning for visit 1. [0072] At visit 1 the patient's previous medical history was taken along with assessment by two questionnaires. These were the Brief Pain Inventory Short Form (BPI-SF) questionnaire and the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life questionnaire (QLQ-C30). [0073] Patients whose level of pain was equal to or greater than 4 on a BS-11 pain score on at least one occasion per day during the 2 day run-in period and who fulfilled the study entry criteria and who were willing to continue were allocated a study number and dosing with study medication was commenced. [0074] Patients were provided with a diary and instructed how to fill it in. Assessments were to be made on a daily basis. Patients were allowed to adjust their dose of study medication to achieve optimal pain control based on pain scores, adverse event profiles and escape medication usage. [0075] At visit 2, approximately 7 to 10 days after visit 1a review of the patient's clinical status was undertaken which included pain control, adverse event profile, strong opioid escape medication usage, change in concomitant medication and change in strong opioid medication. [0076] At visit 3, which took place approximately 14 to 20 days after visit 1, the patient's clinical status was again reviewed as detailed at visit 2. The patients were also asked to complete the BPI-SF and QLQ-C30 questionnaires. [0077] The Box Scale (BS-11) pain score where 0 equals “no pain” and 10 equals “very bad pain” were used as a primary measure of efficacy of the study medication for pain intensity. [0078] The patient diary asked patients to record BS-11 scores for pain three times per day at morning (on waking), lunchtime and evening (just prior to going to bed). [0079] BS-11 scores referring to the previous 24 hours were recorded daily in the evening for sleep, nausea, memory, concentration and appetite. [0080] The number of sprays of study medication and the time it was taken, the doses of regular maintenance medication that was taken and the dose and time of any escape medication taken was also recorded in the diary. Results: [0081] Some of the data collated from this study is described below. [0000] Comparison of Mean Numeric Rating Score (NRS) Pain Scores at All Assessment Periods in Patients with Cancer Related Pain when Administered a Cannabis Based Medicine Extract Containing an Approximately Equal Ratio of THC (27 mg/ml) and CBD (25 mg/ml) or THC (27 mg/ml) in Intention to Treat (ITT) Population. [0082] The efficacy, safety and tolerability of two cannabis based medicine extracts were assessed as described above and the degree of pain at different times of the day was recorded by self assessment on a daily basis. The data was collated and statistical analysis was undertaken. Patients assessed pain on a scale of 0 (no pain) to 10 (extremely bad pain). Table 1 illustrates the mean 11-point NRS pain scores at all assessment periods in the intention to treat (ITT) population. [0000] TABLE 1 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 59) (N = 58) (N = 58) Baseline Mean 5.68 5.77 6.05 Std Dev 1.24 1.33 1.32 Median 5.67 5.67 5.70 Minimum 2.33 2.87 3.50 Maximum 8.25 9.33 9.56 Week 1 Mean 4.90 5.01 5.52 Std Dev 1.52 1.72 1.77 Median 5.06 4.98 5.40 Minimum 0.91 1.62 1.17 Maximum 7.78 8.33 9.28 Week 1 - Mean −0.75 −0.73 −0.60 change Std Dev 1.37 1.10 1.27 from Median −0.72 −0.62 −0.49 baseline Minimum −5.36 −3.33 −4.22 Maximum 3.47 2.33 3.78 Week 2 Mean 4.38 4.98 5.10 Std Dev 1.69 1.70 1.63 Median 4.21 4.92 5.04 Minimum 0.14 1.83 1.00 Maximum 8.10 8.17 8.24 Week 2 - Mean −1.31 −0.94 −0.89 change Std Dev 1.57 1.10 1.47 from Median −1.26 −0.86 −0.90 baseline Minimum −6.12 −3.77 −4.60 Maximum 1.76 1.50 2.74 Last 3 Mean 4.34 4.82 5.39 days Std Dev 1.76 1.77 1.85 Median 4.33 4.89 5.44 Minimum 0.00 1.67 0.78 Maximum 8.22 8.17 9.39 Last 3 Mean −1.32 −0.93 −0.73 days - Std Dev 1.64 1.15 1.51 change Median −1.36 −1.00 −0.60 from Minimum −6.89 −3.94 −4.82 baseline Maximum 1.89 1.50 3.50 [0083] The baseline is a mean of all days in the run-in period and the last 3 days is a mean of last three days on study medication. [0084] Statistical analysis of this data is shown in Tables 2 and 3. [0085] Table 2 details the Analysis of Covariance of the mean 11-point NRS pain scores in the intention to treat (ITT) population. [0000] TABLE 2 Difference from Mean placebo 95% CI p-value THC:CBD −1.37 −0.67 [−1.21, 0.0142 (27 mg/ml:25 mg/ml) −0.14] THC (27 mg/ml) −1.01 −0.32 [−0.86, 0.2447 0.22] Placebo −0.69 — — — [0086] Table 3 details the Non-Parametric Analysis of the mean 11-point NRS pain scores in the intention to treat (ITT) population. [0000] TABLE 3 Difference from Mean placebo 95% CI p-value THC:CBD −1.36 −0.55 [−1.08, 0.0592 (27 mg/ml:25 mg/ml) 0.00] THC (27 mg/ml) −1.00 −0.24 [−0.76, 0.3552 0.28] Placebo −0.60 — — — [0087] The data displayed in the above two tables is for the change in baseline, which is the final result minus baseline scores. A value less than zero indicates a decrease in pain score from baseline. A difference from placebo of less than zero indicates a greater decrease from baseline in active treatment group compared with placebo. [0088] Tables 4 and 5 summarise the NRS for pain by responders in the ITT population. Table 4 details the actual number of responders who had a reduction in pain score from baseline levels. [0000] TABLE 4 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 60) (%) (N = 58) (%) (N = 59) (%) Reduction  >0 41 (68%) 41 (71%) 39 (66%) ≧10% 33 (55%) 33 (57%) 27 (46%) ≧20% 30 (50%) 21 (36%) 21 (36%) ≧30% 23 (38%) 12 (21%) 12 (20%) ≧40% 12 (20%) 10 (17%)  6 (10%) ≧50% 6 (10%) 3 (5%) 4 (7%) [0000] TABLE 5 OR (95% C.I.) OR (95% C.I.) THC:CBD (27 mg/ml:25 mg/ml) THC (27 vs. mg/ml) vs. Placebo Placebo Reduction  >0 1.49 (0.63, 3.52) 1.62 (0.68, 3.90) ≧10% 1.77 (0.83, 3.80) 1.87 (0.86, 4.03) ≧20% 2.17 (1.01, 4.68) 1.13 (0.52, 2.45) ≧30% 2.81 (1.22, 6.50) 1.10 (0.44, 2.73) ≧40% 2.44 (0.84, 7.06) 1.98 (0.67, 5.91) ≧50% 1.66 (0.44, 6.25) 0.80 (0.17, 3.74) [0089] The Odds Ratio (OR) compares whether the probability of an event is the same for two groups. An OR which is equal to 1 infers that the event is equally likely to occur in both groups. An OR which is greater than 1 implies the event is more likely to occur in the first group and an OR less than 1 implies that the event is less likely to occur in the first group. [0090] The data shown above illustrates that the study medication which contained approximately equal amounts of THC and CBD resulted in a greater change from the baseline in pain scores when compared to the study medication which contained THC alone. As such the statistical analysis data demonstrates that the 1:1 THC:CBD is shown statistically to be more efficacious than the THC alone. [0091] The data demonstrates that there is a higher degree of responders who experienced a greater than or equal to 30% reduction in pain in the 1:1 THC:CBD group than in the THC alone group. [0000] Comparison of Mean Numeric Rating Score (NRS) Pain Scores at All Assessment Periods in Patients with Cancer Related Pain when Administered a Cannabis Based Medicine Extract Containing an Approximately Equal Ratio of THC (27 mg/ml) and CBD (25 mg/ml) or THC (27 mg/ml) in Per-Protocol Population. [0092] The efficacy, safety and tolerability of two cannabis based medicine extracts were assessed as described above and the degree of pain at different times of the day was recorded by self assessment on a daily basis. The data was collated and statistical analysis was undertaken. Patients assessed pain on a scale of 0 (no pain) to 10 (extremely bad pain). Table 6 illustrates the mean 11-point NRS pain scores at all assessment periods in the per-protocol population. [0000] TABLE 6 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 43) (N = 47) (N = 47) Baseline Mean 5.62 5.71 5.92 Std Dev 1.25 1.40 1.34 Median 5.67 5.67 5.58 Minimum 2.33 2.87 3.50 Maximum 8.25 9.33 9.56 Week 1 Mean 4.78 4.92 5.31 Std Dev 1.54 1.63 1.84 Median 4.89 4.79 5.22 Minimum 0.91 2.24 1.17 Maximum 7.78 8.33 9.28 Week 1 - Mean −0.81 −0.79 −0.61 change Std Dev 1.43 1.05 1.34 from Median −0.67 −0.63 −0.53 baseline Minimum −5.36 −3.33 −4.22 Maximum 3.47 2.33 3.78 Week 2 Mean 4.32 4.88 5.01 Std Dev 1.66 1.71 1.66 Median 4.07 4.81 4.94 Minimum 0.14 1.83 1.00 Maximum 8.10 8.17 8.24 Week 2 - Mean −1.33 −0.98 −0.80 change Std Dev 1.47 1.11 1.48 from Median −1.39 −0.86 −0.81 baseline Minimum −6.12 −3.77 −4.60 Maximum 1.76 1.50 2.74 Last 3 Mean 4.20 4.79 5.27 days Std Dev 1.64 1.73 1.90 Median 4.00 4.89 5.44 Minimum 0.00 1.78 0.78 Maximum 8.22 8.17 9.39 Last 3 Mean −1.42 −0.92 −0.65 days - Std Dev 1.43 1.15 1.53 change Median −1.44 −1.00 −0.56 from Minimum −6.27 −3.94 −4.82 baseline Maximum 1.89 1.50 3.50 [0093] The baseline is a mean of all days in the run-in period and the last 3 days is a mean of last three days on study medication. [0094] Statistical analysis of this data is shown in Tables 7 and 8. [0095] Table 7 details the Analysis of Covariance of the mean 11-point NRS pain scores in the per-protocol population. [0000] TABLE 7 Difference from Mean placebo 95% CI p-value THC:CBD −1.41 −0.81 [−1.37, 0.0047 (27 mg/ml:25 mg/ml) −0.25] THC (27 mg/ml) −0.94 −0.35 [−0.89, 0.2085 0.20] Placebo −0.59 — — — [0096] Table 8 details the Non-Parametric Analysis of the mean 11-point NRS pain scores in the per-protocol population. [0000] TABLE 8 Difference from Mean placebo 95% CI p-value THC:CBD −1.44 −0.78 [−1.38, −0.19] 0.0120 (27 mg/ml:25 mg/ml) THC (27 mg/ml) −1.00 −0.28 [−0.83, 0.25]  0.2959 Placebo −0.56 — — — [0097] The data displayed in the above two tables is for the change in baseline, which is the final result minus baseline scores. A value less than zero indicates a decrease in pain score from baseline. A difference from placebo of less than zero indicates a greater decrease from baseline in active treatment group compared with placebo. [0098] Tables 9 and 10 summarise the NRS for pain by responders in the per-protocol population. Table 9 details the actual number of responders who had a reduction in pain score from baseline levels. [0000] TABLE 9 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 43) (%) (N = 47) (%) (N = 47) (%) Reduction >0 36 (84%) 38 (81%) 32 (68%) ≧10% 30 (70%) 30 (64%) 23 (49%) ≧20% 27 (63%) 18 (38%) 17 (36%) ≧30% 20 (47%) 11 (23%)  8 (17%) ≧40% 10 (23%)  9 (19%)  5 (11%) ≧50%  5 (12%) 2 (4%) 4 (9%) [0000] TABLE 10 OR (95% C.I.) THC:CBD OR (95% C.I.) (27 mg/ml:25 mg/ml) vs. THC (27 mg/ml) vs. Placebo Placebo Reduction >0 2.41 (0.87, 6.66) 1.98 (0.76, 5.12) ≧10% 2.41 (1.01, 5.73) 1.84 (0.81, 4.20) ≧20% 2.98 (1.26, 7.02) 1.10 (0.47, 2.53) ≧30% 4.24 (1.61, 11.2) 1.49 (0.54, 4.12) ≧40% 2.55 (0.79, 8.17) 1.99 (0.61, 6.46) ≧50% 1.41 (0.35, 5.65) 0.48 (0.08, 2.74) [0099] The Odds Ratio (OR) compares whether the probability of an event is the same for two groups. An OR which is equal to 1 infers that the event is equally likely to occur in both groups. An OR which is greater than 1 implies the event is more likely to occur in the first group and an OR less than 1 implies that the event is less likely to occur in the first group. [0100] The data shown above illustrates that the study medication which contained approximately equal amounts of THC and CBD resulted in a greater change from the baseline in pain scores when compared to the study medication which contained THC alone. As such the statistical analysis data demonstrates that the 1:1 THC:CBD is shown statistically to be more efficacious than the THC alone. [0101] The data demonstrates that there is a higher degree of responders who experienced a greater than or equal to 30% reduction in pain in the 1:1 THC:CBD group than in the THC alone group. [0102] Because this data from the per-protocol population shows the same as the intention to treat population it means that the overall data set is robust. [0000] Comparison of Use of Escape Medication in Patients with Cancer Related Pain when Administered a Cannabis Based Medicine Extract Containing an Approximately Equal Ratio of THC (27 mg/ml) and CBD (25 mg/ml) or THC (27 mg/ml) in Intention to Treat (ITT) Population. [0103] The efficacy, safety and tolerability of two cannabis based medicine extracts were assessed as described above and the number of days in which escape medication was used was recorded. The data was collated and statistical analysis was undertaken. Table 11 illustrates the mean doses per day and its change from baseline in the intention to treat (ITT) population. [0000] TABLE 11 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 60) (%) (N = 58) (%) (N = 59) (%) No of N 54 52 57 days 0 22 (37%) 18 (31%) 21 (36%) used 1 3 (5%) 1 (2%)  6 (10%) 2 3 (5%) 5 (9%) 3 (5%) 3 26 (43%) 28 (48%) 27 (46%) Base- N 53 52 56 line Mean 0.91 1.10 0.80 Std Dev 0.906 1.048 0.892 Median 1.00 1.00 0.71 Min, Max 0.00, 3.50 0.00, 5.00 0.00, 4.00 Last 3 N 54 52 57 days Mean 0.72 0.88 0.68 Std Dev 0.821 0.852 0.662 Median 0.67 1.00 0.67 Min, Max 0.00, 4.00 0.00, 4.33 0.00, 2.00 Change N 53 52 56 from Mean −0.17 −0.23 −0.13 baseline Std Dev 0.500 0.743 0.730 Median 0.00 0.00 0.00 Min, Max −1.50, 1.00  −3.00, 2.00  −2.67, 1.33  [0104] The baseline is a mean of all days in the run-in period and the last 3 days is a mean of last three days on study medication. [0105] Statistical analysis of this data is shown in Tables 12 to 15. [0106] Table 12 details the analysis of number of days that escape medication was used in the intention to treat (ITT) population. [0000] TABLE 12 OR for increasing N No of days 95% CI p-value THC:CBD 60 0.96 [0.46, 2.02] 0.6973 (27 mg/ml:25 mg/ml) THC (27 mg/ml) 58 1.20 [0.57, 2.54] 0.5545 Placebo 59 — — — [0107] Table 13 details the analysis of number of days that escape medication used in the intention to treat (ITT) population when adjusted for baseline proportion of days. [0000] TABLE 13 OR for increasing N No of days 95% CI p-value THC:CBD 60 0.75 [0.29, 1.89] 0.9165 (27 mg/ml:25 mg/ml) THC (27 mg/ml) 58 0.61 [0.23, 1.57] 0.4143 Placebo 59 — — — [0108] Table 14 details analysis of covariance of the mean number of doses of escape medication used per day and the change from baseline in the intention to treat (ITT) population. [0000] TABLE 14 Difference from Mean placebo 95% CI p-value THC:CBD −0.19 −0.04 [−0.25, 0.16] 0.6877 (27 mg/ml:25 mg/ml) (N = 53) THC (27 mg/ml) −0.14  0.01 [−0.19, 0.22] 0.8992 (N = 52) Placebo −0.15 — — — (N = 56) [0109] Table 15 details the Non-Parametric Analysis of the mean number of doses of escape medication used per day and change from baseline in the ITT population. [0000] TABLE 15 Difference from Mean placebo 95% CI p-value THC:CBD 0.00 0.00 [−0.08, 0.00] 0.4223 (27 mg/ml:25 mg/ml) (N = 53) THC (27 mg/ml) 0.00 0.00 [−0.25, 0.00] 0.2552 (N = 52) Placebo 0.00 — — — (N = 56) [0110] The data displayed in the above two tables is for the change in baseline, which is the final result minus baseline scores. A value less than zero indicates a decrease in pain score from baseline. A difference from placebo of less than zero indicates a greater decrease from baseline in active treatment group compared with placebo. [0111] The data for the use of escape medication in patients with cancer related pain in the intention to treat population shows that patients were equally as likely to use escape medication whether they were taking study medication containing approximately equal amount of THC and CBD or THC alone as they would be if they were taking the placebo. [0112] This data is important as it shows that there was no cumulative effect of the cannabinoids upon the opioid medication that the patients were already taking. This would enable doctors and health care workers therefore to still allow patients the use of their escape medication to treat breakthrough pain. [0000] Comparison of Use of Escape Medication in Patients with Cancer Related Pain when Administered a Cannabis Based Medicine Extract Containing an Approximately Equal Ratio of THC (27 mg/ml) and CBD (25 mg/ml) or THC (27 mg/ml) in Per-Protocol Protocol Population. [0113] The efficacy, safety and tolerability of two cannabis based medicine extracts were assessed as described above and the number of days in which escape medication was used was recorded. The data was collated and statistical analysis was undertaken. Table 16 illustrates the mean doses per day and its change from baseline in the per-protocol population. [0000] TABLE 16 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 60) (%) (N = 58) (%) (N = 59) (%) No of N 54 52 57 days 0 22 (37%) 18 (31%) 21 (36%) used 1 3 (5%) 1 (2%)  6 (10%) 2 3 (5%) 5 (9%) 3 (5%) 3 26 (43%) 28 (48%) 27 (46%) Base- N 53 52 56 line Mean 0.91 1.10 0.80 Std Dev 0.906 1.048 0.892 Median 1.00 1.00 0.71 Min, Max 0.00, 3.50 0.00, 5.00 0.00, 4.00 Last 3 N 54 52 57 days Mean 0.72 0.88 0.68 Std Dev 0.821 0.852 0.662 Median 0.67 1.00 0.67 Min, Max 0.00, 4.00 0.00, 4.33 0.00, 2.00 Change N 53 52 56 from Mean −0.17 −0.23 −0.13 baseline Std Dev 0.500 0.743 0.730 Median 0.00 0.00 0.00 Min, Max −1.50, 1.00  −3.00, 2.00  −2.67, 1.33  [0114] The baseline is a mean of all days in the run-in period and the last 3 days is a mean of last three days on study medication. [0115] Statistical analysis of this data is shown in Tables 17 to 20. [0116] Table 17 details the analysis of number of days that escape medication used in the per-protocol population. [0000] TABLE 17 OR for increasing N No of days 95% CI p-value THC:CBD 43 0.99 [0.43, 2.26] 0.5338 (27 mg/ml:25 mg/ml) THC (27 mg/ml) 47 1.55 [0.69, 3.55] 0.2253 Placebo 47 — — — [0117] Table 18 details the analysis of number of days that escape medication used in the per-protocol population when adjusted for baseline proportion of days. [0000] TABLE 18 OR for increasing N No of days 95% CI p-value THC:CBD 43 0.47 [0.14, 1.44] 0.4273 (27 mg/ml:25 mg/ml) THC (27 mg/ml) 47 0.48 [0.14, 1.52] 0.4863 Placebo 47 — — — [0118] Table 19 details analysis of covariance of the mean number of doses of escape medication used per day and the change from baseline in the per-protocol population. [0000] TABLE 19 Difference from Mean placebo 95% CI p-value THC:CBD −0.17 −0.09 [−0.30, 0.12] 0.4061 (27 mg/ml:25 mg/ml) (N = 43) THC (27 mg/ml) −0.10 −0.02 [−0.22, 0.19] 0.8774 (N = 47) Placebo −0.08 — — — (N = 47) [0119] Table 20 details the Non-Parametric Analysis of the mean number of doses of escape medication used per day and change from baseline in the per-protocol population. [0000] TABLE 20 Difference from Mean placebo 95% CI p-value THC:CBD 0.00 0.00 [−0.17, 0.00] 0.1986 (27 mg/ml:25 mg/ml) (N = 43) THC (27 mg/ml) 0.00 0.00 [−0.25, 0.00] 0.1038 (N = 47) Placebo 0.00 — — — (N = 47) [0120] The data displayed in the above two tables is for the change in baseline, which is the final result minus baseline scores. A value less than zero indicates a decrease in pain score from baseline. A difference from placebo of less than zero indicates a greater decrease from baseline in active treatment group compared with placebo. [0121] Again the data for the per-protocol population correlates with the intention to treat population. [0000] Summary of EORTC QLQ-C30 Constipation Scale in Patients with Cancer Related Pain when Administered a Cannabis Based Medicine Extract Containing an Approximately Equal Ratio of THC (27 mg/ml) and CBD (25 mg/ml) or THC (27 mg/ml) in Intention to Treat (ITT) Population. [0122] The efficacy, safety and tolerability of two cannabis based medicine extracts were assessed as described above and the degree of constipation as assessed by the EORTC QLQ-C30 constipation scale both at baseline during assessment in week 1 and at the end of the study. The data was collated and statistical analysis was undertaken. Table 21 illustrates the observed data and the change from baseline in the intention to treat (ITT) population. [0000] TABLE 21 THC:CBD THC (27 mg/ml:25 mg/ml) (27 mg/ml) Placebo (N = 58) (N = 57) (N = 59) Baseline Mean 50.00 33.33 40.68 Std Dev 33.19 33.92 35.59 Median 33.33 33.33 33.33 Minimum 0.00 0.00 0.00 Maximum 100.00 100.00 100.00 End of Mean 41.50 32.67 42.31 Study Std Dev 31.57 28.96 35.00 Median 33.33 33.33 33.33 Minimum 0.00 0.00 0.00 Maximum 100.00 100.00 100.00 Change Mean −8.16 0.68 3.21 from Std Dev 24.09 24.99 25.79 baseline Median 0.00 0.00 0.00 Minimum −100.0 −66.67 −66.67 Maximum 33.33 66.67 100.00 [0123] The baseline was taken at week 1. [0124] Statistical analysis of this data is shown in Tables 22. [0125] Table 22 details the Analysis of Covariance of the degree of constipation as assessed by the EORTC QLQ-C30 constipation scale in the intention to treat (ITT) population. [0000] TABLE 22 Difference Adjusted from Mean placebo 95% CI p-value THC:CBD −5.74 −7.97 [−16.81, 0.87] 0.0769 (27 mg/ml:25 mg/ml) THC (27 mg/ml) −3.11 −5.35 [−14.16, 3.47] 0.2326 Placebo 2.23 — — — [0126] The study described above was a Phase III trial and overall the study medication which contained approximately equal amounts of THC and CBD achieved a statistically significant improvement in comparison to placebo in pain as measured on a Numerical Rating Scale (p=0.014), this was a primary endpoint of the study. A responder analysis showed that approximately 40% of patients taking the study medication with approximately equal amounts of THC and CBD showed a greater than 30% improvement in their pain (p=0.024). [0127] The study medication that contained THC alone did not show a significant effect in pain (p=0.24). The trial therefore suggests that the study medication that contains CBD along with THC is more effective at reducing cancer related pain than the study medication that contained THC alone. [0128] The analysis of the second primary endpoint showed that there were no significant changes in the use of escape medication in either of the study medications as compared with placebo. The improvements in pain were therefore attributable to the positive effects of the study medication containing approximately equal amounts of THC and CBD. [0129] The data also additionally shows that patients receiving the CBME containing approximately equal amounts of THC and CBD experienced a beneficial relief from opiate induced constipation. [0130] It can therefore be concluded that a medication that contains approximately equal amounts of THC and CBD offers a new treatment option in the treatment of pain in patients with cancer related pain, and for treatment of constipation. REFERENCES [0000] Cleeland C. S., et al. (1994) Quality improvement guidelines for the treatment of acute pain and cancer pain. Journal of the American Medical Association 274, 1874-80 Formukong E. A., Evans A. T. and Evans F. J. (1988) Analgesic and Anti-inflammatory activity of constituents of Cannabis sativa L. Inflammation 12 (4), 361-371 Holdcroft A. et al. (1997a) Pain relief with oral cannabinoids in familial Mediterranean fever. Anaesthesia 52 (5), 483-6 [0134] Holdcroft A. et al. (1997b) Clinical trial experience with cannabinoids. Pharm. Sci. 3, 546-550 [0135] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. [0136] All references disclosed herein are incorporated by reference in their entirety.

The present invention relates to treatment of cancer related pain and constipation. Preferably the subject in need is administered a combination of the cannabinoids cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). More preferably the cannabinoids are in a predefined ratio by weight of approximately 1:1 of CBD to THC.

FIELD OF THE INVENTION [0001] This application pertains to a device for retrieving golf balls and tees from either a standing position or a sitting position within a golf cart. BACKGROUND OF THE INVENTION [0002] Golf is sport enjoyed by young and old in many lands. It is a game played from Scotland to Pebble Beach, U.S.A., to Australia. Many people as they age find that either due to an increase in body fat, or due to joint and muscle aches that they are not able to bend down to retrieve their tee after they hit the ball. Nor are they able to bend over to retrieve the ball from the cup or a sand trap as may be required. [0003] For these men and women, there is indeed a need for a device that would permit them to quickly and easily retrieve their tee and the ball respectively. BRIEF DESCRIPTION OF FIGURES [0004] [0004]FIG. 1 is a perspective view of this invention. [0005] [0005]FIG. 2 is a side perspective view of the lower portion of this invention. [0006] [0006]FIG. 3 is a front perspective view of the lower portion of this invention. The rear view is a mirror image thereof. [0007] [0007]FIG. 4 is a left perspective view of the lower portion of this invention. The right side view is a mirror image thereof. [0008] [0008]FIG. 5 is a top perspective view of the lower portion of this invention. [0009] [0009]FIG. 6 is a bottom perspective view of this invention with the jaws in the closed position. [0010] [0010]FIG. 7 is a bottom perspective view of this invention with the jaws in the open position. [0011] [0011]FIG. 8 is a side perspective view of the upper portion of this invention. [0012] [0012]FIG. 9 is a front perspective view of the top portion of this invention. [0013] [0013]FIG. 10 is a view similar to FIG. 7 but with a golf ball disposed in the jaws of this invention. [0014] [0014]FIG. 11 is a perspective view of the operating mechanism of this invention. [0015] [0015]FIG. 12 is an exploded view of an accessory to be mounted on the device of this invention. SUMMARY OF THE INVENTION [0016] This invention provides a tool or device that permits persons to retrieve either a golf tee or a golf ball from either a standing or seated position. The device features a retractable trigger mechanism disposed in a tubular shaft , which trigger opens and closes a pair of jaws which serve to secure the tee or ball for retention. For the ball, retention is within a cup dispensed above the pair of jaws. For the tee, if standing it is retained in a hemispherical opening between the two jaws; and if lying down prone on the grass, the tee is also retained within the cup disposed above the jaws of the device. [0017] It is a first object to provide a device that quickly and easily retrieves a golf ball and retains it for the operator. [0018] It is a second object to provide a device that can retrieve a golf tee from either a vertical or supine position. [0019] It is a third object to provide a device to pick up a golf ball from a golf hole, a water hazard or sand trap as may be desired. [0020] It is a fourth object to provide a device that can be easily operated with one hand and which requires no batteries. [0021] It is a fifth object to provide a retriever device that retains the captured tee or ball once retrieved. [0022] It is a sixth object to provide a low-cost ball retriever that is low in cost of manufacture. [0023] These objects and others recited will appear hereinafter or also be obvious from the drawings and the figures provided herein. DESCRIPTION OF THE PREFERRED EMBODIMENT [0024] The device of this invention is seen to comprise an upper portion consisting of a trigger mechanism, a lower grabbing portion comprising of a cup covered over by a pair of side opening jaws with a shaft in between and which shaft connects the upper and lower portions, and carries the trigger mechanism. [0025] First we turn to FIGS. 1, 8 and 9 where the upper portion of device 10 is seen. The device 10 comprises an elongated tubular member 17 , of plastic such as polyvinyl chloride, chlorinated PVC, or ABS (Acrylonitrile-butadiene-styrene) of about 1 inch in diameter. Schedule 40 is a suitable product and is preferred to schedule A which has a smaller wall thickness. Tubular member 17 may be of an elongation between two and three feet or even longer for extremely tall persons. A plastic or rubber cap 11 may be threaded on or glued to one end, the upper end 45 of the device. An elongated slot is cut through the wall thickness at 180 degree spacing to provide a resting place for the arms 15 A of trigger 15 . [0026] One slot is designated 13 A, and the other 13 B. Together they form the aligned slot 13 . See FIG. 8 for the aligned slot 13 , and FIG. 9 for each individual slot. [0027] The trigger 15 of the trigger mechanism 60 —seen in FIG. 11, is formed from a pair of opposed rigid wire members that are disposed in and carried by the shaft in slot 13 as will be discussed supra at the discussion of FIG. 11. The pair of wires are designated trigger arms 15 A. [0028] Each trigger arm 15 A may be optionally spray coated with rubber or have rubber “spaghetti” 16 disposed thereon. The rubber coating or covering serves to increase the comfort for the user of the trigger 15 and the device 10 . [0029] The discussion now moves to the lower portion 46 of this device. Reference is made to FIGS. 2 , 3 , 4 , 5 and 6 . Seen specifically in FIGS. 3 and 4, emanating from one of the spaced bores 19 near the bottom of tubular shaft 17 are a pair of opposed flexible wires 21 . As seen in FIG. 2 and FIG. 4, the wires 21 are disposed at about a 60 degree angle from within shaft 17 and are connected at their lower terminals to their respective wire stud 22 . Each stud 22 is a threaded bolt that is threadedly engaged with a self tapping bore 36 , one of which studs and bore is disposed 180 degrees opposed to the other such stud and bore on the side 39 of a jaw 23 . [0030] Seen also in FIG. 3 wherein adjacent the stud 22 is a spring stud 29 of similar construction. The stud 29 is disposed through a reinforcement washer 35 . Two of these studs-washer-bore combinations are found spaced apart opposite sides of each of the two jaws 23 , which together with the cup 25 form the grab unit 20 . Note that FIG. 4 constitutes a 90 degree rotation of the device as shown in FIG. 3. [0031] One end of each coil spring 27 —there being two opposed such springs, is attached to a stud 29 on one jaw side 39 . See FIG. 4. Wherein the two jaws 23 are in open position, but in FIG. 3, the jaws are in closed position. [0032] The two arcuate jaws 23 , are pivotally mounted by pivot bolts 32 which pass through a reinforcing washer 33 into a self tapping aperture near the bottom of cup 25 . The reader's attention is turned to the relative disposition of the two jaws 23 to the ball 97 in FIG. 4. Thus it is seen that the jaws 23 when pivoted to an open position, as here, essentially move outwardly to be able to receive either a ball or a tee 98 . FIG. 3 shows a tee 98 in a retained position within a pair of mirror image semicircular cutouts, 38 on the base 37 of each jaw wherein the jaws 23 are in a juxtaposed closed position. [0033] In FIG. 5, a top perspective view, much of what has been discussed infra can be seen. Thus the two wires 21 are seen to diverge outwardly, from their bores 19 per FIG. 2, and then downwardly to a point of connection at their respective studs 22 . [0034] Each jaw is a complex shaped element, each of which can be seen in FIG. 5 to be semicircular in shape, and abutting the other when in a closed position, when viewed from the top, that is in the horizontal plane. While in FIG. 6, each jaw also includes a jaw base 37 , which is semicircular in shape and which is disposed at a generally 90 degree angle to the respective jaw side 39 . The edge 40 of each jaw 23 's base 37 has a centrally disposed mirror image semicircular cutout 38 . The total circular opening formed from both openings 38 , i.e. the two semicircles define a circular opening which is sized large enough to surround the shaft of a golf tee when closed, beneath the cup portion of the tee. Refer back to FIG. 2 where a tee 98 is shown in retention in the closed position of the two jaws 23 abutting one another on their bottom surface. [0035] The mounting of the two coil springs 27 is also demonstrated in FIG. 6. The two springs lie in opposed mirror image arc segments an equal amount inward along the respective side 39 of its jaw 23 . The pair of springs are mounted such that one end is one jaw and the other end is on the respective same side of the opposite jaw. When in the closed position an interface is formed between the two jaws. In this FIGURE the two coil springs are in their relaxed state. [0036] The reader should now turn to FIG. 7, the bottom view showing the jaws 23 in open position. Contrast this view with FIG. 6 which shows the entire grab unit 20 , to fully understand the movement of the jaws. Here the springs have been moved from a first relaxed position to a second tensed position, as the jaws are opened from their interface, by a tugging upwardly on the two wires connected to the trigger 15 . When the trigger is moved upwardly, thus tugging on the wires, the two jaws pivot each on the pair of pivot bolts aforementioned, to open as shown in FIG. 7 to thus reveal the hemispherically shaped cup having a bottom facing opening and which is recessed within the jaws. The pair of coil springs 27 are moved from an at rest position to a stretched position. When the trigger arms are released, they return downwardly within the slot, and the coil springs 27 relax, such that the jaws re-close. [0037] The cup 25 has a central bore 26 therein at its closed end, to which is cemented or otherwise attached, hollow tubular shaft 17 . See FIG. 7. [0038] [0038]FIGS. 8 and 9 depict the upper area of the shaft 17 in two different orientations used to show the relative placement of the trigger 15 . Trigger 15 has two arms, 15 A, one of which is disposed through a slot 13 A and other through a slot 13 B in the side wall of the tubular shaft. These two aligned slots 13 A, 13 B, communicate with each other in combination with the interior of the tubular shaft 17 . For comfort of the user the trigger 15 may be preferably slightly arcuate as shown in FIG. 9, but such is not required. The trigger members 15 may be rubber covered by a sleeve 16 or spaghetti, to enhance user comfort. A cap 11 closes off the end of the tubular shaft distant from the grab unit 20 . Such cap 11 may be threaded on, adhered, or integrally molded in place with the formation of the shaft. [0039] [0039]FIG. 10 is a view from the same vantage point as FIG. 7. From this view it is easy to see that cup 25 is sized to readily receive golf ball 97 . It is also seen that the two jaws 23 separate adequately upon opening to permit the ball 97 to be fully enveloped by the grab unit 20 such that when the jaws 23 close, the ball 97 is totally within the grab unit 20 . [0040] In FIG. 11, the internal operating mechanism of this device is seen. The trigger arms 15 A of trigger 15 are each seen to be a slightly arcuate wire segment connected by a U-shaped center section 15 U. Each of the two control wires 21 are knotted through the base or crook of the U-shaped center section 15 U and are retained by cleat 62 from becoming unknotted. [0041] While not illustrated, a single wire may be used to serve as both control wires 21 , by being tied at the midpoint into the U-shaped section 15 U, while also being crimped into position to prevent disengagement in a manner similar to that done in a two-wire system. [0042] In FIG. 12, a small accessory is seen the mountable to the shaft 17 . A Velcro® pad 52 is adhered to the shaft 17 , and a matingly engageable complimentary pad 53 also of Velcro® is attached to a pencil or pen 54 . The writing instrument can be removed for use as needed to keep score, yet is always present when needed, disposed along the shaft away from the trigger 15 . METHOD OF USE [0043] When a player is desirous of retrieving a ball, from the hole or from on the grass, he/she lifts the trigger arms 15 upwardly within the slots 13 A, 13 B [FIG. 8]. Such effort tugs on the two wires 21 [FIG. 11]. The two wires, when raised by the triggers 15 , pull the binding posts 22 upwardly, causing the jaws 23 to pivot open. The jaws which partially overlie the cup, move in an arc upwardly to reveal the cup 25 . The cup is placed in contact with ball 97 and such “impact” can be perceived by the user. He/she then releases the trigger arms 15 , which then move downwardly and the jaws are brought back to a closed position by the two springs 27 , which want to relax, the jaws close underneath the ball 97 and cause it to be retained totally within the confines of the grab unit 20 . A second actuation of the trigger when the device is raised off the ground, causes the jaws to open again and the ball to fall by gravitational pull. [0044] The effort to retrieve a tee requires the same motion. Actuation once to retrieve, actuation a second time of the trigger to drop the tee. If the tee 98 is vertically disposed in the ground, the semicircular cutouts 38 fit around the shaft of the tee when closed around the vertical tee. A tug on the device upwardly removes the tee from the ground. [0045] If the tee is lying down, a push motion of one jaw upon the tee 98 , not unlike a dust pan and brush is used to capture the tee within the confines of the two jaws 23 and cup 25 . [0046] It is seen that I have developed a tool useful for golfers like Casey Martin who must ride in a cart, as well as for other aged and infirm players who have difficulty bending over to retrieve the ball and/or tee. The device of this invention is light weight, and the body of which can be made of plastic such as PVC or ABS, in white or in colors. It is within the skill of the art to determine the exact resistance needed in the coil springs 27 , which may be approximately ¼ inch in diameter. [0047] Since certain changes may be made in the above described apparatus without departing from the scope of the invention herein involved, it is intended that matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

A device for retrieving a golf ball or tee, which comprises a tubular shaft having a pair of trigger arms disposed in said shaft, and movable therein, each of which is connected to a respective opposed openable jaw. The jaws overlie a hemispherical recessed cup sized to receive a golf ball, such that when the jaws are in a closed position, the captured ball is totally within the confines of the jaws and said cup. The jaws are spring loaded such that a release of the trigger arms causes the springs to relax, thereby causing the jaws to return to a closed position retaining the ball. A tee is captured similarly, but within a pair of semicircular cutouts within the base of each jaw upon the application of a gentle tug upwardly by the user. A second pull of the trigger arms release the captured ball or tee.

BACKGROUND OF THE INVENTION [0001] During the analog age, owners of copyrighted audio and video content did not overly concern themselves about the unauthorized duplication of content by the average consumer. The nature of the analog medium prohibits most consumers from making a significant number of unauthorized duplicates because analog duplicates are always inferior to the source. Thus within a few generations, the duplicates are useless. Further, as most analog medium required physical contact with the playback device, the original source degraded each time a copy was made. Thus content owners generally did not expend significant resources in applying the few existing copy protection schemes to most analog content. [0002] The advent of the digital age combined with cheap mass storage devices enabled the average user to make unlimited, near perfect duplicates from a given digital content source such as a CD or DVD. Thus, for the first time, owners and distributors of content had to contend with the average consumer having the power to mass-produce copyrighted digital content. [0003] The proliferation of relatively inexpensive high speed telecommunications gave the average consumer the additional ability to mass distribute copyrighted content. Thus today, many consumers choose to download content, especially, music, via the public internet, in lieu of purchasing the content through authorized channels. [0004] Owners of copyrighted content have responded utilizing a variety of technical means. They have placed electronic locks within the content which ostensibly prevents the unauthorized copying or distributing of copyrighted content. Today the use of technology to limit access to copyrighted content is known as digital rights management (DRM) [0005] Digital rights management endeavors to return control over the distribution of copyrighted content to the copyright holder by making it difficult, if not impossible, to save, duplicate, or transmit, the restricted content. These methods were met with varying levels of success. One technique involves the user connecting to the content owner's internet server to periodically validate playback permission for content. Another method includes encoded expiration dates within the content. [0006] Both methods have severe limitations. The former method requires an internet connection which effectively prevents the user of the content in a non-PC environment, such as a car stereo. The latter method has proven exceptionally easy to circumvent. [0007] Today, the standard in digital rights management is the public/private key combination. In cryptography, a public key is a value provided by some designated authority as an encryption key that, combined with a private key derived from the public key, can be used to effectively encrypt messages and digital signatures. The use of combined public and private keys is known as asymmetric cryptography. A system for using public keys is called a public key infrastructure. [0008] Hand held devices present special challenges for digital rights management. They often do not have internet connections for validating playback permission. Additionally, many modern devices have removable memory card which may permit the distribution of content without the content owner's permission. [0009] Thus many digital rights management system include a method of validating content which is embedded within the content itself. These systems must validate both the length of time the content is authorized, but also who is authorized to view the content, and on what machine or machines, the content may be viewed. [0010] Currently digital rights management systems fall into two classes. The former class restricts access to the content or service, the latter class encrypts the content itself. For purposes of this disclosure, encryption is the process of transforming information (referred to as content or rich media) using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information. In this disclosure, the word decryption also implicitly refers to the reverse process, to make the encrypted information readable again (i.e. to make it unencrypted). Additionally digital rights management may utilize a combination of both classes. [0011] Restricting access to content or services requires the potential user to validate that he or she is authorized to have access to the content. Typical validation systems include username/password combinations, router passphrases, and field validation e.g. DVD region codes, etc. Restricting access is very popular because it is very cheap and easy way to control content. Username/password type systems are fairly well known and can be easily implemented without much financial or computational cost. Consequently, this method can be used to restrict access to any type of content and especially rich media where the files tend to be large and encryption would be computationally intensive. [0012] The limitation of merely restricting access is that if someone intercepts that content it may be fairly easy to read. For example, restricting access can be analogized to a locked briefcase containing very sensitive documents. If the lock is broken, the documents are wholly unprotected. This occurs often when wireless networks fail to take advantage of the various security options available. A third party can trespass on the wireless network and even intercept and view any unencrypted transmissions. [0013] Therefore, for particularly sensitive content, copyright holders often encrypt the content itself, using a public/private key combination. There are many types of public/private key algorithms. Public key cryptography is a fundamental and widely used technology around the world, and is the approach which underlies such Internet standards as Transport Layer Security (TLS) (successor to SSL), PGP and GPG. [0014] The distinguishing technique used in public key-private key cryptography is the use of asymmetric key algorithms because the key used to encrypt a message is not the same as the key used to decrypt it. Each user has a pair of cryptographic keys—a public key and a private key. The private key is kept secret, while the public key may be widely distributed. Messages are encrypted with the recipient's public key and can only be decrypted with the corresponding private key. The keys are related mathematically, but the private key cannot be feasibly (ie, in actual or projected practice) derived from the public key. It was the discovery of such algorithms which revolutionized the practice of cryptography beginning in the middle 1970s. [0015] In contrast, Symmetric-key algorithms, variations of which have been used for some thousands of years, use a single secret key shared by sender and receiver (which must also be kept private, thus accounting for the ambiguity of the common terminology) for both encryption and decryption. To use a symmetric encryption scheme, the sender and receiver must securely share a key in advance. [0016] Because symmetric key algorithms are nearly always much less computationally intensive, it is common to exchange a key using a key-exchange algorithm and transmit data using that key and a symmetric key algorithm. PGP, and the SSL/TLS family of schemes do this, for instance, and are called hybrid cryptosystems in consequence. [0017] A simple (and impractical) example of a public/private key would be the child's algorithm of encoding messages by shifting letters by a fixed number. E.g., “A” becomes “B” and “B” becomes “C”, etc. So if the public key for the algorithm described in this paragraph is Increment by 1, then the private key, derived solely from the public key would be Decrement by 1. So the word “Patent” becomes “Qbufou” a wholly meaningless word. However, by applying the private key to it “Qbufou” reverts to Patent. [0018] Content encryption takes longer than restricting access and requires more computer power and time. It is particularly well suited for small, extremely sensitive files such as e-mails. Content encryption is often used for downloaded rich media such as online movies. The content is encrypted once; send to the user, along with the key to unlock the content. In such a case, each user receives the identically encrypted content. [0019] The limitation of this model is both technical and financial. Since each user downloads the identically encrypted content, it is impossible to limit access to a single machine or offer different levels of access. [0020] As a further enhancement, some copyright holders have used the serial number of the user's video card as part of the encryption key. This was met with limited success, most notably as computer users routinely upgrade their computers, peripherals and cards are likely to be discarded thus making the content inaccessible. BRIEF DESCRIPTION OF THE INVENTION [0021] The instant invention relates to a method and apparatus for restricting access to digital content through the use of an exemplary form of digital encryption which ties the delivered content to a user, a specific destination device, a specific network, or one or more of the above. Specifically, the encryption/decryption keys are unique in each content consumption session, whether download or stream, which permits the content owner to provide multiple levels of access, i.e. different users may purchase different levels of access to the same content. For example, one user might want to use content on multiple playback devices, while another user might only need access on a single playback device. DETAILED DESCRIPTION OF THE EMBODIMENTS [0022] The present invention relates to an exemplary method of controlling access to digital media, residing on a computer system, destined for playback, storage, or re-transmittal to another computer system, by generating a private encryption key on the first computer system for the purpose of encrypting and decrypting said digital media content through the use of a standard encryption key generating algorithm and a seed, where said seed is obtained from the identifying information of the second computer system or destination device. [0023] This present invention differs from previous content rights management system in that the server encrypts the requested content differently for each download or streaming session. Whereas in most content rights management system, including conditional access systems, the encryption is performed once by the content server and each destination device receives identically encrypted content. [0024] FIG. 1 illustrates a high level block diagram of the system. Destination Device 130 requests content and a certain level of access via Request Channel 160 . This request is routed through Internet 120 to the content provider's server, Server 110 , via Delivery Channel 170 . Server 110 has both Content 150 as well as Policy Engine 140 which delineates the maximum amount of access that a user can have over the delivered content. Server 110 queries Policy Engine 140 to determine what information is needed from Destination Device 130 in order to create a personalized encryption key to grant the requested level of access. Server 110 then queries Destination Device 130 to obtain the requested information to create a seed used to create a private key that will unlock the content and give the requested access to the content. [0025] Keys are used to control the operation of a cipher or code (an algorithm for performing encryption and decryption) so that only the correct key can convert encrypted text (ciphertext) to plaintext. Many ciphers are based on publicly known algorithms or are open source, and so it is only the difficulty of obtaining the key that determines security of the system, provided that there is no analytic attack (i.e., a ‘structural weakness’ in the algorithms or protocols used), and assuming that the key is not otherwise available (such as via theft, extortion, or compromise of computer systems). In this disclosure a key may be fixed or variable length. [0026] In this invention, every time the destination device attempts to access the content, a key is generated based upon the permissive usage policies and the user/destination device information. If the destination device attempts to decrypt and play the content in violation of the permissive usage policies, then the generated key won't be able to decrypt to content, or no key will be generated at all. [0027] FIG. 2 illustrates a high level schematic diagram of the digital rights management system. Destination Device 270 requests access to content from Server 210 . Server 210 queries Policy Engine 240 to obtain the permissive uses of the requested content. Policy Engine 240 returns the permissive uses, i.e. policy rules, to server 210 , which transmits the permissive uses to Destination Device as well as a list of required information from the destination device for each level of access. Destination Device 270 transmits the required information to Server 210 which then creates a seed based on the permissive uses and destination device identification, then generates the encryption key from said seed. [0028] Destination Device 270 knows which level of access was requested and the encryption algorithm being public, the Destination Device can determine the decryption key. Alternatively, Server 210 transmits the decryption key to Destination Device 270 . [0029] FIG. 3 illustrates a flow diagram of one embodiment of the invention. At Step 310 , the Destination Device makes a request for access to content. The Destination Device transmits the relevant identification to the Server at Step 320 . At Step 330 , the Server obtains the policy rules for the requested content. Based on the identification information and the policy rules, a seed is created which is used by the computer systems to derive an encryption key is generated at step 340 . At step 350 , the server encrypts the content and transmits the encrypted content and policy rules to the destination device at step 360 . At step 370 , the destination device generates the decryption key. At step 380 , the destination device decrypts the content for playback or viewing. [0030] FIG. 4 illustrates a second embodiment of the invention. At Step 410 , the destination device makes a request to the server for access to content. AT Step 420 , the destination device transmits its identification information to the Server. At step 430 , the server receives the policy rules for the requested content. At step 440 a seed is created which is used by the computer systems to derive an encryption key. The server then encrypts said key at step 450 . At Step 460 , the server transmits the policy rules, the encrypted content, and the encrypted key to the destination device. At Step 470 , the destination device generates the key that will be used to decrypt the content protection key. At step 480 , the content key is decrypted. At Step 490 the content is decrypted. [0031] FIG. 5 illustrates an example of a policy algorithm. For purposes of this disclosure a policy algorithm is a simple numeric value which delineates the maximum access to content the user may have. For example, in the current disclosure, Fields 510 x relates to the user limitations, Fields 520 x relate to the machine limitations, Fields 530 x relate to the location limitations. Location limitations may include or exclude. For example, a content provider may decide that his content can only be played in the United States. Conversely, the content provider may decide that his content cannot be played in the United States. When the destination device generates the key for playback, the seed used will include the location information in generating the decryption key. If the current location is not authorized by the permissive usage, then the decryption key will not work. [0032] Field 540 relates to the temporal limitations such as expiration date. Field 510 a stores the maximum number of users while Field 510 b stores any age restrictions, i.e. adult content. Field 520 a delineates the number of machines that the content can be authorized to play on, while Field 520 b delineates any hardware limitations such as type of machine (e.g. cell phone, PDA, personal computer, television, etc.) certain brands, networks, and permissible software and hardware. Field 530 a stores any country limitation. Country limitations may either include or exclude. For example, a content provider may limit the playback of contact to the United States. Conversely, the content provider may forbid playback within the United States. Field 530 b stores the Zip code limitation. Field 530 c stores any other geographic limitation that the content provider chooses to impose. As with Field 530 a , Fields 530 b and 530 c may either include or exclude a geographic area. [0033] FIG. 6 illustrates an example of the identification information that the destination device would send to the server. Field 610 stores the user information, e.g. user id and password, SIM card serial number; and biometrics such as Iris print, fingerprint, or voiceprint identification. Field 620 stores machine information such as MAC address, computer serial number, device make and model, processor id, device resources, etc. Field 630 stores the current geographical field of the destination device such as Zip code, IP address, cell tower information, GPS coordinates, proximity information such as landmarks. [0034] FIG. 7 illustrates a sample key generated from the policy rules and identification information. Field 710 stores the username and password, field 720 the minimum age for viewing the content. Field 730 stores any biometric information such as fingerprints, voice prints, etc., Field 740 stores the destination device serial number(s), including the SIM card serial number. Field 750 stores the MAC address. Field 770 stores the computer make and model. Field 780 stores the IP address of the destination device. Field 790 stores the length of time that the content can be viewed, and fields 795 stores network information such as cellular vs. Wi-Fi and which cellular network. BRIEF DESCRIPTION OF THE DRAWINGS [0035] FIG. 1 illustrates a high level block diagram of the system [0036] FIG. 2 illustrates a high level schematic diagram of the digital rights management system. [0037] FIG. 3 illustrates a flow diagram of one embodiment of the invention by which the content itself is encrypted. [0038] FIG. 4 illustrates a second embodiment of the invention by which the system encrypts the decryption key. [0039] FIG. 5 illustrates a high level schematic diagram of a policy algorithm [0040] FIG. 6 illustrates a high level schematic diagram of the identification information that the destination device sends to the server. [0041] FIG. 7 illustrates a sample key generated from the policy rules and identification information.

The instant invention relates to a method and apparatus for restricting access to digital content through the use of an exemplary form of digital encryption which ties the delivered content to a user, a specific destination device, a specific network, or one or more of the above. Specifically, the encryption/decryption keys are unique in each content consumption session, whether download or stream, which permits the content owner to provide multiple levels of access, i.e. different users may purchase different levels of access to the same content. For example, one user might want to use content on multiple playback devices, while another user might only need access on a single playback device.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 08/358,209 filed Dec. 16, 1994, now U.S. Pat. No. 5,520,635. BACKGROUND OF THE INVENTION This invention relates to a method and an associated device for removing material from a body or patient. The method and device are especially useful for removing clots from subcutaneous vascular bypasses or shunts. Vascular bypasses, whether made of human (graft) tissue or polymeric material, become regularly blocked with blood clots which must be removed. A common technique for cleaning clogged vascular bypasses is surgical: the skin surface and the underlying shunt are cut open and instruments are inserted through the openings to extract clumps of clotted blood. The disadvantages of this conventional surgical procedure are well known. Because of the blood which naturally spurts out through the incision, the cleaning of the graft or bypass must be performed in the operating room. Of course, all the disadvantages or side-effects of surgery pertain: pain to the patient, danger of infection, loss of blood, as well as time and expense due to the requisite hospital staff. Another common method of cleaning clogged vascular bypasses is dissolution of the clot via biological enzymes. The most common enzyme in current use is urokinase. The disadvantages of this method include high cost of the enzymes and a delay of as much as several hours while the enzyme acts on the clot. Systemic side effects of these enzymes, notably bleeding at other sites in the body due to unwanted yet uncontrolled dissolution of other "good" clots, are also seen. Other devices have attempted to clear clot from these vessels via mechanical percutaneous means. These devices, however, macerate the clot external to the device and frequently such macerated clot may not be captured and extracted from the body. In such cases, embolization to the lungs and other organs may occur. Biochemical aberrations secondary to clot and red blood cell emulsification by high powered devices may also occur. OBJECTS OF THE INVENTION An object of the present invention is to provide a new technique, and an associated instrument, for removing a vascular clot or other intravascular debris. A more particular object of the present invention is to provide such a technique and associated instrument for removing a vascular clot or other intravascular debris in a subcutaneous vascular bypass or shunt which connects an artery with a vein to facilitate hemodialysis. Another object of the present invention is to provide an associated instrument or device for performing the technique. A further object of the present invention is to provide such a technique which reduces, if not eliminates, at least one or more disadvantages of conventional surgical or enzymatic clot removal techniques. Another, more particular, object of the present invention is to enable the removal of high viscosity clots using tubes of small diameter. Yet another particular object of the present invention is to provide such a technique or method which reduces the time required to remove a subcutaneous vascular clot. These and other objects of the present invention will be apparent from the drawings and detailed descriptions herein. SUMMARY OF THE INVENTION A device for removing material from inside a patient comprises, in accordance with the present invention, an elongate tubular member having a suction port, an irrigation port and an intake port, with the suction port and the irrigation port being spaced from the intake port. A vacuum generator is operatively connected to the suction port for applying suction to the tubular member. A cutting element is mounted to the tubular member for severing a portion of material (e.g., clot) drawn partially in through the intake port upon disposition of the tubular member through a skin surface so that the suction port and the irrigation port are located outside the patient while the intake port is located in an internal organ of the patient. Fluid pressurization componentry is operatively connected to the tubular member for feeding a fluid thereto to pressurize the tubular member to eject the portion of the material severed by the cutting element. A closure, e.g., a reciprocating or rotating closure, is mounted to the tubular member for closing the intake port upon a severing of the portion of the material by the cutting element and prior to ejection of the severed material by the fluid pressurization componentry. The cutting element may be movably, i.e., rotatably and/or slidably mounted to the tubular member, whereas the closure includes a surface of the cutting element. Pursuant to another feature of the present invention, the fluid pressurization componentry includes means for feeding the pressurizing fluid past the cutting element. The cutting element may be provided with a fluid-flow channel so that fluid fed by the fluid pressurization componentry flows through the cutting element. Where the tubular member is cylindrical, the cutting element may have a D-shaped cross-section defining two parallel D-shaped channels. The fluid pressurization componentry includes at least one of those channels. The suction port and the irrigation port may be located on opposite sides of the intake port. As discussed below, where this embodiment of the invention is used, the suction and irrigation ports are disposed outside the patient while the intake port is disposed inside the patient during a thrombectomy or other material removal procedure. Pursuant to a further feature of the present invention, a balloon is mounted to an external surface of the tubular member and means are connected to the balloon for alternately inflating and deflating the balloon. Pursuant to a specific feature of the present invention, the cutting element may have an internally threaded bore, while a guidewire having an externally threaded segment is connected to the cutter element via the internally threaded bore and the externally threaded segment. The use of this embodiment of the invention is described below. Pursuant to yet another feature of the present invention, the tubular member is provided on an inner surface with a constricting sleeve, while the cutter element is provided with a projection at a downstream end. The projection is insertable into the sleeve after a shifting of the cutter element past the intake port, to seal the device and then both mechanically and hydraulically push a severed mass through the sleeve and reduce the mass in size prior to an ejection thereof by the fluid pressurization componentry. The cutting element may be spring loaded or shiftable under the action of fluid pressure. A method for removing a clot in accordance with the present invention utilizes an elongate tubular member having a suction port, an irrigation port and an intake port, the suction port and the irrigation port being spaced from the intake port. The method comprises inserting a portion of the tubular member through a skin surface of a patient and into an internal organ such as a subcutaneous vascular component so that the suction and irrigation ports are located outside of the patient and the intake port is located in the internal organ. Upon completion of the insertion, suction is applied to the suction port of the tubular member to thereby draw material in the internal organ towards intake port of the tubular member. Then a portion of the material sucked inside the tubular member is severed as the device is sealed and fluid pressure is applied to the severed material to push the severed material along and ultimately out through the suction section of the tubular member. Preferably, the application of fluid pressure is implemented in part by closing the intake port in the tubular member and feeding a fluid stream to the tubular member. The fluid stream is more preferably fed to the tubular member simultaneously with the closing of the intake port. Where the tubular member is provided with a rotating or reciprocatable cutter element, the severing of the sucked-in material includes shifting the cutter element so that a cutting edge of the cutter element moves past the intake port of the tubular member, while the closing of the intake port includes blocking the intake port with the cutter element. The pressurizing fluid fed to the tubular member for ejecting the severed mass may flow through the tubular member past the cutter element. Where the cutter element is provided with a fluid-flow channel, the application of fluid pressure includes feeding fluid through the channel. In practice, fluid pressure need not be applied to every severed mass during a material removal operation (e.g., a thrombectomy). However, during every thrombectomy, a severed clot mass will become lodged in the tubular member, thereby blocking the tubular member and preventing further clot removal until the blocking clot mass is removed. In accordance with the present invention, such a stuck clot mass is forcibly ejected by applying a spike of fluid pressure. The generation of a sufficiently high clot ejection pressure is facilitated, particularly in thin tubular members, by the closing of the intake port (the intake port). Although closure of the intake port may be effectuated by a separate door element, the closure is advantageously effectuated by the cutter element itself. Such a solution reduces the number of parts and enables a maximal reduction in the size of the tubular member. The smaller the diameter of the tubular member the better, for example, for purposes of speeding the healing of the resulting smaller puncture ports in the patient's skin. Where the tubular member is cylindrical, the cutter element may have a D-shaped cross-section defining two parallel D-shaped channels. In that case, the application of fluid pressure includes the feeding of fluid into one of the channels. The application of fluid pressure to the tubular member to eject a severed mass generally includes the steps of connecting a pressurizable fluid source to the tubular member and feeding fluid under pressure from the source and at least partially along the tubular member past the intake port. Where the tubular member is provided with a cutter element, the fluid path extends past the cutter element, while the severing of sucked-in material includes shifting or rotating a cutting edge of the cutter element past the intake port. Where the cutter element is provided with a fluid-flow channel, the fluid path extends through the channel. Preferably, a procedure in accordance with the present invention further comprises the step of applying suction to the tubular member at a point downstream of the intake port to pull the severed mass from the intake port along the tubular member. Where the irrigation port and the suction port are disposed on opposite sides of the intake port, the inserting of a portion of the tubular member includes inserting a selected end of the tubular member through a skin surface of a patient into the internal organ (e.g., vascular component) and subsequently out of the internal organ and the skin surface so that the suction port and the irrigation port are located outside the patient while the intake port is located in the internal organ. According to another feature of the present invention, the method further comprises (a) inserting a catheter with an inflatable balloon in a deflated configuration into the internal organ, (b) subsequently inflating the balloon, and (c) after inflation of the balloon, pulling the catheter and the balloon along the internal organ towards an insertion point of the tubular member into the internal organ, whereby clot material is shifted through the internal organ toward the intake port. Where an end segment of the tubular member is inserted into the internal organ of the patient, the tubular member may be longitudinally shifted through or along the internal organ to remove material along an extended portion of the internal organ. In this particular embodiment of the present invention, it is frequently advantageous if at least a substantial part of the tubular member is made of a flexible material, so that the longitudinal shifting of the tubular member may include bending the tubular member. This feature is advantageous where the internal organ is in the vascular system of the patient. The bending allows the device to follow curves in the vascular system. It is to be noted that a tubular member used in a method in accordance with the present invention may be completely rigid, partially rigid and partially flexible, or substantially entirely flexible. Generally, at least the cutter element and a section of the tubular member about the cutter element is rigid. This rigid section may be a small part of the entire tubular member. Where the entire tubular member is rigid, it is useful in a procedure where the tubular member has three ports as described above. According to an additional feature of the present invention, the tubular member is provided with a cutter element having an internally threaded bore. Then the method further comprises inserting a first guidewire into an internal organ such as a vascular component prior to insertion of the tubular member, the insertion of the tubular member including inserting the tubular member into the vascular component along the guidewire. After insertion of the tubular member into the vascular component, the guidewire is removed. After removal of the first guidewire from the tubular member, a second guidewire having an externally threaded segment is inserted into the tubular member. Upon insertion of the second guidewire into the tubular member, the threaded segment of the guidewire is screwed to the threaded bore to thereby attach the second guidewire to the cutter element. After attachment of the second guidewire to the cutter element, the second guidewire is moved to shift the cutter element past the intake port. According to a further feature of the present invention, where the tubular member is provided on an inner surface with a constricting sleeve and is further provided with a cutter element having a projection at downstream end, the projection is moved into the sleeve after shifting of a cutting edge of the cutter element past the intake port. The projection on the cutter element and the sleeve cofunction to squeeze a severed clot mass into a reduced size prior to a pushing of the severed portion of the clot along the tubular member by fluid pressure or fluid stream. The projection at the downstream end of the cutter element may define a shoulder on the cutter element which crushes severed clot mass against a ledge on the sleeve. This action further macerates severed clot mass and assists in facilitating the removal of severed clot material from the tubular member. It is to be noted that the cutter element in this case may be provided with one or more fluid flow channels of small diameter for generating fluid jets which serve to further macerate or particulize severed clot material. Where the tubular member carries a reciprocatable cutter element provided with spring loading, the severing of clot mass including shifting the cutter element in a first direction so that a cutting edge of the cutter element moves past the intake port, while the method further comprises shifting the cutter element in a second direction opposite the first direction after a severing of the portion of the clot. The shifting of the cutter element in at least one of the first direction and the second direction is performed under action of the spring loading. Alternatively, in the absence of spring loading, the shifting of the cutter element in the first and/or the second direction may include the application of fluid pressure to the cutter element. For example, an oscillating pressure may be applied to a tongue or finger of the cutter element disposed inside a pressure channel in the tubular member. The cutter element reciprocates under the action of the oscillating pressure. The present invention provides a technique and an associated device for removing material in an internal organ of a patient, such as a clot in a subcutaneous vascular bypass. The technique reduces, if not eliminates, one or more disadvantages of conventional surgical clot removal techniques. For example, the technique reduces the time required to remove surgically a subcutaneous vascular clot. Reduced time means less blood loss and reduced surgical costs. The technique also requires less time than enzymatic treatment and eliminates the expense of costly enzymes. It is to be noted, that a prosthetic device implanted inside a patient is considered an internal organ for purposes hereof. For example, a vascular bypass made of synthetic materials is considered to be an organ for purposes of the present invention. Furthermore, as compared to other clot disruption devices, this device only processes clot after the clot has been moved internal to the device via the associated suction capabilities. Only then is a portion of the clot severed and ejected, without any possibility of loss into the patient's vascular system. The remaining clot in the vascular vessel as yet unprocessed is not affected in any way by the device. A clot removal device in accordance with the present invention entails a self-limiting anti-clogging system that inherently slows or stops the intake procedure concurrently with any clot buildup in the suction section of the clot ejection path of the tubular member. This anti-clogging feature does not interfere with the ongoing fluid pressure cleaning and ejecting system. A clot removal device in accordance with the present invention may be used to remove material other than clots from organs other than blood vessels and vascular prostheses. The device may be used, for example, to remove malignant tissue from the liver or other solid organ (device inserted through vascular system or directly from overlying skin surface). A device in accordance with the present invention can also be used in conjunction with or as a part of a cutting, scraping, shaving or other instrument in various internal organs, to clear suction ports or channels which frequently become clogged and otherwise would necessitate removal and cleaning. Many instruments use novel techniques to accomplish their stated goals. They all, however, generate debris which may be subsequently processed for ejection from the body through a smaller channel or whith a larger particle size than would otherwise appear possible. This enhanced two stage process, using another instrument and then a device as described herein for debris removal, would permit greater efficiency and improve the safety of these other instruments by quickly opening clogged suction channels and rapidly ejecting debris from the various organ systems. It is to be noted further that interal organs of a patient may be protected from high ejection pressures by generating the high pressures only upon closure of the clot-intake port. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is partially a schematic side elevational view and partially a block diagram of a device for removing a subcutaneous blood clot, in accordance with the present invention. FIG. 2 is partially a schematic longitudinal cross-sectional view and partially a block diagram showing a cutting component of the device of FIG. 1. FIG. 3 is partially a schematic side elevational view and partially a block diagram showing an alternative cutting component for the device of FIG. 1. FIG. 4 is partially a schematic cross-sectional view of subcutaneous tissues and a vascular bypass and partially a schematic side elevational view of the device of FIG. 1, showing a step in an operation removing a clot in the bypass. FIGS. 5-7 are schematic partial perspective views of respective alternative embodiments of the distal end of tubular member 12, on an enlarged scale. FIG. 8 is a schematic partial cross-sectional view of a modified obturator in accordance with the present invention. FIG. 9 is partially a schematic cross-sectional view of subcutaneous tissues and a vascular bypass and partially a schematic side elevational view of a device similar to that of FIG. 1, showing a modified clot removal technique in accordance with the present invention. FIG. 10A is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a modified thrombectomy device in accordance with the present invention, showing the device in a clot intake phase of an operating cycle. FIG. 10B is a view similar to FIG. 10A, showing the device of FIG. 10A in a cutting or macerating phase of an operating cycle. FIG. 11 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a thrombectomy device similar to that of FIGS. 10A and 10B, showing particular implementations with respect to materials. FIG. 12A is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of another thrombectomy device in accordance with the present invention, showing the device in a clot intake phase of an operating cycle. FIG. 12B is a view similar to FIG. 12A, showing the device of FIG. 12A upon completion of a cutting or macerating stroke. FIG. 13 is a schematic cross-sectional view taken along line XIII--XIII in FIG. 12A. FIG. 14 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a thrombectomy device similar to that of FIGS. 12A, 12B and 13, showing particular implementations with respect to materials. FIG. 15 is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a further thrombectomy device in accordance with the present invention. FIG. 16 is a schematic side elevational view, on an enlarged scale, of a modification of the thrombectomy device of FIG. 15. FIG. 17 is a diagram illustrating use of the thrombectomy device of FIG. 15 or 16. FIG. 18 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of an additional thrombectomy device in accordance with the present invention. FIG. 19 is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a modified thrombectomy device in accordance with the present invention. FIG. 20 is a schematic transverse cross-sectional view taken along line XX--XX in FIG. 19. FIG. 21 is schematic side elevational view, on an enlarged scale, of yet another thrombectomy device in accordance with the present invention. FIG. 22 is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of yet another thrombectomy device in accordance with the present invention. FIG. 23 is a schematic transverse cross-sectional view taken along line XXIII--XXIII in FIG. 22. FIG. 24 is a schematic partial longitudinal cross-sectional view showing a variation on the thrombectomy device of FIGS. 22 and 23. FIG. 25 is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of yet a further thrombectomy device in accordance with the present invention. FIG. 26 is a schematic transverse cross-sectional view taken along line XXVI--XXVI in FIG. 25. FIG. 27 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of a thrombectomy device in accordance with the present invention. FIG. 28 is partially a block diagram and partially a schematic partial longitudinal cross-sectional view, on an enlarged scale, of another thrombectomy device in accordance with the present invention. FIG. 29 is a schematic transverse cross-sectional view taken along line XXIX--XXIX in FIG. 28. FIG. 30 is a schematic transverse cross-sectional view taken along line XXX--XXX in FIG. 28. FIG. 31 is a partial cross-section view of a cutting element and wire shown in FIGS. 28 and 29. FIGS. 32 and 33 are diagrams depicting different steps in the use of the thrombectomy device of FIGS. 28-31. FIG. 34 is a schematic partial longitudinal cross-section view of a thrombectomy device in accordance with the present invention, illustrating a manufacturing technique. FIG. 35 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of yet another thrombectomy device in accordance with the present invention. FIG. 36 is a transverse cross-sectional view taken along line XXXVI--XXXVI in FIG. 35. FIG. 37 is a schematic partial longitudinal cross-sectional view, on an enlarged scale, of yet a further thrombectomy device in accordance with the present invention. DETAILED DESCRIPTION As illustrated in FIG. 1, a surgical instrument or device 10 for removing a blood clot from a patient comprises an elongate tubular member 12 having a most distal first port 14, an intermediately located second port 16 and a most proximal third port 18 all spaced from each other along the tubular member. Tubular member 12 is provided with a bend or elbow 20 for facilitating the insertion of the distal end portion of the instrument into a patient so that distal port 14 and proximal port 18 both lie outside the patient, while intermediate port 16 lies inside a subcutaneous blood vessel, graft or vascular bypass VBP (FIG. 4). A vacuum generator or suction source 22 is operatively connected to distal port 14 for applying suction to tubular member 12. A hollow obturator 24 is shiftably inserted inside tubular member 12. At a proximal end, obturator 24 is operatively connected to an automatic reciprocating linear or translatory drive 26, while at a distal end the obturator 24 is provided with a circular blade or cutting edge 28 (FIG. 2). Drive 26 reciprocates obturator 24 back and forth across intermediate port 16. Upon a retraction stroke, intermediate port 16 is uncovered by obturator 24 to permit suction from suction source 22 to draw a blood clot BC in bypass VBP partially into the tubular member 12 through intermediate port 16 (see FIG. 4). A subsequent distally directed stroke of obturator 24 pushes cutting edge 28 against blood clot BC, thereby severing or macerating a portion thereof. As further illustrated in FIG. 1, a supply or reservoir 30 is operatively connected via a luer lock or similar function adapter 32 to proximal port 18 for feeding a saline irrigation fluid to tubular member 12 upon a severing of a portion of blood clot BC by cutting edge 28 of obturator 24. The forward pushing motion of obturator 24 serves in part to assist the pulling action of suction source 22 to remove the severed clot portion from tubular member 12. A greater push is provided, however, by the saline irrigant from supply or reservoir 30. The irrigant is placed under pressure to facilitate the removal of severed clot portions from tubular member 12. Obturator 24 is provided with an aperture 34 spaced from cutting edge 28 by approximately the same distance as that between intermediate port 16 and proximal port 18. Thus, upon a severing of blood clot BC during a distally directed stroke of obturator 24, obturator 24 is connected to pressurized irrigant reservoir 30 via proximal port 18 and aperture 34, thereby providing a timely flow of irrigant to force the severed clot material from tubular member 12. This pushing action is believed to so facilitate the removal of severed clot material that obturator 24 and tubular member 12 can be constructed with diameters thinner than those which might have only suction forces to remove severed clot material. Accordingly, small diameter tubes may be used to remove clots of relatively high density. Aperture 34 and proximal port 18 cofunction as a valve to permit the flow of irrigant only upon a severing of a blood clot BC by cutting edge 28 of obturator 24. During the pressurization of obturator 24 by the irrigant from reservoir 30, obturator 24 is juxtaposed to intermediate port 16 so as to prevent the flow of pressurizing fluid into bypass VBP. This juxtaposition occurs periodically inasmuch as the invention contemplates an alternating cycle: initially a vacuum and other assist devices suck clots into the tubular clot-removal device. Only after that has been accomplished and the obturator changes position does the pressure cycle commence during which the obturator and/or pressurized saline solution ejects the clot material. As shown in FIG. 2, cutting edge 28 is a circular edge provided by beveling obturator 24 at a distal end thereof. As shown in FIG. 3, an obturator element 36 insertable inside tubular member 12 is provided at a distal end with a longitudinally extending slot 38 formed along longitudinal edges with blades 40 and 42 for alternately slicing off portions of a blood clot sucked into tubular member 12 through intermediate port 16 by operation of suction source 22. Obturator element 36 is operatively connected at a proximal end to a reciprocating rotary drive 44. Drive 44 functions to shift blades 40 and 42 alternately past intermediate port 16. It is to be noted that rotary drive 44 may be sufficient to macerate a clot to a particle size suitable for evacuation through tubular member 12 by suction. However, obturator element 36 may be additionally connected to a reciprocating drive for facilitating clot particle ejection or removal. Pressurized saline may or may not be provided. The requirements will vary depending on the characteristics of the particular clots. As depicted in FIG. 4, a distal end of tubular member 12 is inserted through a skin surface SS of a patient into a subcutaneous tubular vascular component in the form of bypass VBP and subsequently out of bypass VBP and skin surface SS so that distal port 14 and proximal port 18 are located outside the patient while intermediate port 16 is located in bypass VBP. Upon completed insertion of the device, suction source 22 is operated to apply suction to distal port 14 to thereby draw blood clot BC in bypass VBP towards intermediate port 16. Upon a drawing of the clot at least partially into tubular member 12 through intermediate port 16, a portion of the clot is severed inside tubular member 12 by a distally directed stroke of obturator 24 or an angular shifting of obturator element 36. Subsequently, the severed clot portion is removed from tubular member 12 through distal port 14, in part because of the feeding of irrigant under pressure from reservoir 30 and in part because of the suction applied by source 22. It is to be noted that the present invention is used in conjunction with conventional mechanical surgical techniques for drawing clot material from opposite ends of bypass VBP towards intermediate port 16. For example, a wire (not illustrated) inserted through the same or a different puncture site may be manipulated to catch clotted clumps of blood and drag the captured clumps towards intermediate port 16 where the clumps are subjected to a suction force tending to draw the clot material into intermediate port 16. Also, Fogarty balloon catheters (not illustrated) may be used to push the clots, or another catheter (not illustrated) may inject fluid under pressure into the bypass graft to enhance further the flow of the clot to intermediate port 16 and out through tubular member 12. FIGS. 5-7 illustrate respective alternative embodiments of the distal end of tubular member 12. As shown in FIG. 5, a sharp point 46 for skin penetration is provided by beveling the entire distal end of tubular member 12. Alternatively, as depicted in FIG. 6, the distal most port 14 in tubular member 14 is spaced from a sharpened distal tip 48 of the tubular member. As illustrated in FIG. 7, a tapered or sharpened distal tip 50 of tubular member 12 may be severed or otherwise separated from the rest of the tubular member, thereby forming port 14. As shown in FIG. 8, an obturator 52 extending through a vascular access tube 64 as described hereinabove may have a substantially solid distal end portion 54. That end portion 54 is formed with a groove 56 and a passageway 58 for enabling the transmission of irrigant from a proximal most port 68 in a distal direction upon the completion of a cutting stroke of obturator 52 at an intermediate port 66. Alternatively, a solid, but loosely fitting, obturator may be used, where pressurized irrigant flows around the obturator. FIG. 9 illustrates a stage in a thrombectomy procedure utilizing a clot removal instrument or device 70. As described hereinabove with reference to FIG. 1, device 70 comprises an elongate tubular member 72 having a most distal first port 74, an intermediately located second port 76 (suction intake port) and a most proximal third port 78 all spaced from each other along the tubular member. Tubular member 72 is provided with a bend or elbow 80 for facilitating the insertion of the distal end portion of the instrument into a patient so that distal port 74 and proximal port 78 both lie outside the patient, while intermediate port 76 lies inside a subcutaneous blood vessel, graft or vascular bypass VBB. A vacuum generator or suction source 82 is operatively connected to distal port 74 for applying suction to tubular member 72. A hollow obturator 84 is shiftably inserted inside tubular member 72. At a proximal end, obturator 84 is operatively connected to a pressurizable fluid reservoir 86 such as a syringe, while at a distal end the obturator 84 is provided with a cutting edge or blade (not shown in FIG. 9). Obturator 84 is manually reciprocated inside tubular member 72. Upon a distally directed cutting stroke of obturator 84, a portion of a blood clot CB sucked into tubular member 72 through port 76 is severed. In addition, cutting element or obturator 84 blocks port 76, thereby enabling or facilitating the forcible ejection of the severed blood clot mass from port 74 by the application of fluid pressure to tubular member 72 upon a pressurization of fluid reservoir 86. Upon a subsequent retraction stroke of cutting element or obturator 84, clot intake port 76 is uncovered by obturator 84 to permit suction from suction source 82 to draw another portion of blood clot CB in bypass VBB partially into the tubular member 72 through intermediate port 76. A subsequent distally directed stroke of obturator 84 pushes the cutting edge thereof against blood clot CB, thereby severing or macerating a portion thereof. Again, as described hereinabove with respect to FIG. 1, saline irrigant from reservoir 86 provides sufficient pressure to remove any severed clot mass which would otherwise become stuck inside tubular member 72. As further illustrated in FIG. 9, a catheter 88 with a collapsed balloon 90 attached to an external surface may be inserted into the patient's vascular system, particularly into bypass VBB, so that the balloon is located on a distant side of the blood clot CB. A fluid reservoir 92 (e.g., syringe) is then pressurized to inflate balloon 90, as shown in FIG. 9. Subsequently, a traction force is placed on catheter 88 to drag blood clot CB along bypass VBB towards clot intake port 76 of instrument 70. This procedure facilitates removal particularly of a large clot CB. As depicted in FIGS. 10A and 10B, a modified thrombectomy device comprises a tubular member 94 provided on an inner surface 96 with a sleeve 98. A cutting element 100 in the form of an obturator has a longitudinally extending channel 102 with a narrowed distal end segment 104. The distal end of cutting element or obturator 100 is provided with an axially extending projection 106 which is insertable into sleeve 98 upon a distally directed cutting stroke of cutting element or obturator 100, as shown in FIG. 10B. Projection 106 partially defines a shoulder 108 which is engageable with sleeve 98. Channel 102 of cutting element or obturator 100 communicates at a proximal port 109 (FIG. 10A) with a pressurizable fluid reservoir 110 (FIG. 10B), while an end of tubular member 94 opposite cutting element 100 communicates with a suction source or vacuum generator 112. Upon a drawing of a clot mass CM into tubular member 94 through a window or clot intake port 114 therein, a distally directed stroke of cutting element 100 severs the clot mass. The clot mass is forced by projection 106 through sleeve 98, thereby macerating or reducing the severed clot mass in size. This maceration or reduction in size further facilitates the removal of the severed clot mass from tubular member 94. The severed clot mass is also crushed (partially) between sleeve 98 and shoulder 108. In addition, the severed clot mass is subjected to a jet of saline irrigant (not shown) exiting cutting element 100 via narrowed distal end segment 104 of channel 102. As illustrated in FIG. 11, tubular member 94 may be partially made of a flexible material. More particularly, tubular member 94 may include a flexible proximal section 116 connected to a flexible distal section 118 by a rigid section 120 which includes window or clot intake port 114. In this case, cutting element 100 has a flexible body 122 and a rigid tip 124. If sleeve 98 and projection 106 are not omitted, they are preferably provided on rigid section 120 and rigid tip 124, respectively. The modified thrombectomy device of FIG. 11 is particularly useful in removing clots from blood vessels which do not lie near a skin surface. Rigid section 120 may be positioned proximally to an intravascular clot via well known guidewire techniques. As depicted in FIGS. 12A, 12B, and 12C, another thrombectomy device comprises a tubular member 126 provided with a cross-sectionally D-shaped cutting element or obturator 128 which defines a suction channel 130 and a pressurization channel 132. Suction channel 130 is connected to a suction source or vacuum generator 134, while pressurization channel 132 is coupled at an irrigant inlet port 135 to a pressurizable irrigant or saline reservoir 136. At a distal end cutting element 128 is beveled to define a cutting edge or blade 138. Upon a distally directed stroke of cutting element 128 (compare FIGS. 12A and 12B), cutting edge 138 moves past a clot intake window or port 140 in tubular member 126 to sever a potion of clot projecting into the tubular member through window 140. In the event that the suction from source 134 is insufficient to pull the severed clot portion from tubular member 126, the pressure of fluid in reservoir 136 is increased. Cutting element remains in the position shown in FIG. 12B to thereby close or block window 140 and enable or facilitate a build-up of fluid pressure behind the severed clot mass sufficient to forcibly eject the clot mass from tubular member 126. As indicated by an arrow 142 in FIG. 12B, saline irrigant from reservoir 136 flows through irrigation channel 132 and around the beveled leading edge of cutting element 128 into suction channel 130. As illustrated in FIG. 14, the thrombectomy device of FIGS. 12A, 12B and 13 may be partially flexible for insertion through arcuate blood vessels. More specifically, tubular member 126 may have a flexible body segment 144 and a rigid tip 146 provided with window 140. Similarly, cutting element or obturator 128 may have a flexible body segment 148 and a rigid tip 150 provided with cutting edge 138. It is to be noted that in the thrombectomy probe embodiments of FIGS. 12A, 12B, 13 and 14, as well as in all of the other thrombectomy devices disclosed herein, the cutting element 128 has a cutting edge or blade 138 functioning to sever a clot mass pulled into tubular member 126 through intake port or window 140 and also has a surface (internal or external) which functions to close the window during a subsequent pressurization of the tubular member to eject a stuck clot therefrom. Although not every severed clot mass will require forcible ejection via hydrostatic pressurization or hydrodynamic forces, every thrombectomy procedure utilizing a thin tubular member as disclosed herein will require one or more applications of fluid pressure to hydrostatically or hydrodynamically eject a lodged clot mass from the tubular member. As depicted in FIG. 15, another thrombectomy device comprises a tubular member 152 having a narrow section 154 connected at an irrigant inlet port 156 to a pressurizable reservoir 158 containing a saline solution or irrigant. Tubular member 152 has a wide section 160 in which a cutting element 162 in the form of an obturator is slidably disposed for motion past a clot intake window or port 164. Cutting element 162 is hollow, i.e., defines a fluid flow channel 166 which communicates with a suction source or vacuum generator 168. Cutting element 162 enters tubular member 152 at an opening (not shown) therein. FIG. 16 shows the thrombectomy device of FIG. 15 provided with a bend 170 in narrow section 154 proximate to wide section 160. As indicated in FIG. 17, the thrombectomy device of FIG. 15 (or 16) is used by inserting narrow section 154 into a vascular component VC, as indicated by arrow 172, so that window 164 is disposed inside vascular component VC and so that the opposite ends of tubular member 152, as well as the irrigant inlet and suction ports thereof) are disposed outside the patient. Pressurizable irrigant is fed into tubular member 152 via narrow section 154, as indicated by an arrow 174, while macerated clot mass is removed via wide section 160 (arrow 176). It is to be noted that irrigant from any pressurizable reservoir (e.g., syringe) disclosed herein may flow or leak at a low rate for lubrication purposes during unclogged operation of the respective thrombectomy device. When a severed clot mass becomes stuck in the tubular member, the pressure of the fluid irrigant is increased to impose an ejection force on the stuck clot mass. In FIG. 18, a tubular member 178 of a thrombectomy device has a narrow irrigant inlet section 180 and a wide suction section 182. A cutter element 184 comprises a cylindrical segment perforated with a multiplicity of bores 186 so that the cutter element is moved in a cutting stroke, as indicated by an arrow 188, upon the application of fluid pressure to a conical rear surface 190 of the cutting element via narrow irrigant inlet section 180. After a severing of a clot mass (not shown) protruding into tubular member 178 via an opening, port or window 192 and after removal of the severed clot mass from the tubular member, a cable or wire 194 attached to cutter element 190 is pulled to return the cutting element to a precutting position in which window 192 is open for drawing in further clot mass. In the embodiment of FIG. 18, as in essentially all the thrombectomy devices discussed herein, fluid pressure is used to eject any severed clot mass which becomes lodged in the tubular member. The cutting element is maintained in position over the clot intake window or port 192 to ensure the generation of sufficient pressure to eject the ledged clot material. In the embodiment of FIG. 18, a sleeve (not shown) may be provided in tubular member 178 downstream of window 192 to arrest downstream motion of cutting element 184 upon closure of window 192 thereby. Alternatively, wire 194 may be used to hold cutting element 184 in position during a clot ejection phase of a thrombectomy procedure. In any event, bores 186 are sufficiently small in total cross-sectional area to enable fluid pressure to push cutting element 184 past window 192, but sufficiently large in total cross-sectional area to enable pressurization of the tubular member for ejecting a stuck clot mass. FIGS. 19 and 20 show a slight modification of the thrombectomy device of FIG. 18, in which a tubular member 196 has an essentially uniform diameter or cross-section and in which a rear surface 198 of a cylindrical cutting element 200 is planar rather than conical. A pressurizable fluid reservoir 202 is connected to tubular member 196 at an end opening or port (not shown) thereof. Otherwise, the essential structure and operation of the thrombectomy device of FIGS. 19 and 20 is the same as that of the thrombectomy device of FIG. 18, as indicated by the use of like reference designations. FIG. 21 shows a generalized thrombectomy device with a tubular member 204, a clot intake port 206, and an irrigant port 208 at one end. In addition, an inflatable balloon 210 is provided on tubular member 204 for occluding a clotted vascular component and dragging a clot to a desired location in the vascular component for removal. It is to be understood that balloon 210 may be provided on any of the thrombectomy devices disclosed herein which are longitudinally shiftable along a clotted vascular component during a thrombectomy procedure. As additionally shown in FIG. 21, a first pressurizable fluid reservoir 212 is connected to a cutting obturator 214 slidably disposed inside tubular member 204. Pressurizable fluid reservoir 212 supplies a fluid to the tubular member for purposes of lubricating the sliding relationship between obturator 214 and tubular member 204 and for purposes of forcibly ejecting a stuck clot mass from tubular member 204. Another pressurizable fluid reservoir 214 communicates with balloon 210 via tubular member 204 for inflating the balloon as indicated at 216. As illustrated in FIGS. 22 and 23, a spring loaded thrombectomy device comprises a tubular member 218 provided with a longitudinally extending partition 220 dividing the lumen of tubular member 218 into a fluid feed channel 222 and a suction channel 224. A pressurizable fluid reservoir 226 communicates with fluid feed channel 218, while a suction source or vacuum generator 228 communicates with suction channel 224, both at an opening or port (not shown) at a proximal end of tubular member 218. A cutting element 230 is slidably disposed in suction channel 224 at a distal end thereof and is biased in the distal direction by a helical compression spring 232 disposed between the cutting element and a sleeve 234 attached to partition 220 and to tubular member 218 along an inner surface thereof. A wire 236 extends through cutting element 230 and along suction channel 224 for pulling the cutting element in a proximal direction in opposition to a force exerted by spring 232, thereby moving cutting element 230 past a clot intake window or port 238 to sever an inwardly protruding clot mass and to close the window for enabling or facilitating a pressurized ejection of the severed clot mass. A ball 240 on wire 236 transmits force between wire 236 and cutting element 230. Cutting element 230 is provided with longitudinally extending bores 242 for delivering pressure fluid from a distal end of fluid feed channel 218 to suction channel 224 upstream of a stuck clot mass. Fluid from reservoir 226 flows along a path extending through feed channel 218, through bores 242 in cutting element 230 and past window or port 238 into suction channel 224. In virtually all of the thrombectomy devices disclosed herein, pressure fluid flows such a path. Fluid pressure upstream of a clogging clot mass is augmented by the closing of the clot intake port by the cutting element. FIG. 24 depicts a variation of the thrombectomy of FIGS. 22 and 23, in which helical compression spring 232 is replaced by a plurality of smaller compression springs 244 angularly spaced from one another about an inner surface of tubular member 218. Those skilled in the art can readily appreciate that other variations in the structure for reciprocating the cutting element may be derived. For example, instead of compression springs, tension springs might be used. FIGS. 25 and 26 illustrate a thrombectomy device wherein reciprocation of a cutting element 246 is accomplished hydraulically. A saline fluid from a periodically pressurizable reservoir 248 is fed to an opening or port (not shown) at a proximal end of a fluid feed channel 250 defined in a tubular member 252 by a partition 254. Cutting element 246 has an elongate eccentrically disposed drive member 256 located along an inner surface of tubular member 252 and projecting into channel 250 at a distal end thereof, the drive member 256 having a pressure face 258 acted on by the fluid in channel 250. Upon a pressurization of channel 250, cutting element 246 moves in a distal direction, thereby uncovering a clot intake port 260 in tubular member 252. Fluid from channel 250 leaks though bores 262 provided in drive member 256 to a chamber 264 at a distal end of tubular member 252. Pressure in that chamber can be increased sharply to force cutting element 246 in the proximal direction, thereby severing any clot mass sucked into tubular member 252 through port 260 owing to a depressurization of a suction channel 266 by a suction source or vacuum generator 268. Cutting element 246 has a pressure face 270 which is greater in surface area than finger pressure face 258, whereby a force may be exerted on cutting element 246 to produce a cutting stroke. Pressure is reduced to enable a distally directed return stroke. Cutting element 246 is provided with additional bores to enable forcible clot mass ejection, as described above. FIG. 27 illustrates, in generalized format, a thrombectomy device wherein a cutting element 272 is slidably disposed outside a tubular thrombectomy member 274 for motion past a clot intake port 276 to sever a clot mass (not shown) sucked into the tubular member through the port 276 and to temporarily cover the window during extraction of the clot at least by a suction force applied to one end of the instrument, as schematically indicated by an arrow 278. An irrigating or lubricating fluid is fed to tubular member 274, for example, from an opposite end thereof, as indicated by an arrow 280. In the event that the suction force is inadequate to extract the severed clot mass, the irrigant may be pressurized, e.g., by a syringe or other pressurizable fluid source 282, to forcibly eject the clot mass. The closing of port 276 by an inner surface of cutting element 272 enables or at least facilitates the generation of sufficient pressure to eject the severed clot mass. It is to be noted that an external cutting element, as described with reference to FIG. 27, may be utilized in a thrombectomy device wherein pressure fluid is fed to the tubular member at the same end thereof to which a suction source is coupled. In that event, a partition divides the tubular member into a fluid feed channel and a suction channel. It is to be further noted that the pressure fluid flows along a path past the clot intake opening or port and through the cutting element. This is the case even where the cutting element extends from the irrigant inlet end (left side in FIG. 27). In another embodiment of a thrombectomy device illustrated in FIGS. 28-31, reciprocating movement of a cutting element 284 is implemented via a stiff wire 286 which is connected to the cutting element, as described below. Wire 286 extends eccentrically along a fluid feed channel 288 defined by a partition wall 290 disposed along an inner surface of a tubular thrombectomy member 292. Partition wall 290 projects at a distal end 294 into a D-shaped channel 296 (FIG. 29) in cutting element 284. As shown in FIGS. 29 and 31, wire 286 traverses a bore 298 (FIGS. 29 and 31) in a wall 300 (FIG. 29) of cutting element 284. Wire 286 is provided with an external screw thread 302 which threadingly mates with an internal screw thread 304 in bore 298. At a distal side of cutting element 284, wire 286 extends through an aperture 306 in tubular member 292. During a thrombectomy operation, a clot mass is sucked into tubular member 292 through an opening or port 308 therein, through the operation of a suction source 310 connected to a proximal end of a suction channel 312 defined in tubular member 292 by partition wall 290. Wire 286 is then pushed in a distal direction to move cutting element 284 and particularly a cutting edge 314 thereof past opening or port 308. At least a portion of the severed clot mass is disposed inside channel 296 of cutting element 284. A suction force applied by suction source 310 via channel 312 pulls the severed clot mass through channel 296 in cutting element 284 and proximally through channel 312. In the event that the severed clot mass becomes lodged inside cutting element 284 or suction channel 312, a fluid reservoir 316 communicating with fluid feed channel 288 via an opening or port 318 is pressurized to build up a back pressure to forcibly eject the lodged clot mass from tubular member 292. Subsequently to the extraction of the severed clot mass from tubular member 292, wire 286 is pulled to move cutting element 284 back in the proximal direction to uncover opening 318 and thereby initiate another cutting cycle. As depicted diagrammatically in FIG. 32, the thrombectomy device of FIGS. 28-31 may be used in a procedure wherein a guidewire 320 is first inserted into a tubular vascular component TVC of a patient. Subsequently to the placement of guidewire 320, tubular member 292 with cutting element 284 is inserted into vascular component TVC over guidewire 320, as shown in FIG. 32. Then guidewire 320 is withdrawn from the patient and replaced with wire 286, as indicated in FIG. 33. Wire 286 is a kind of guidewire. The insertion of wire 286 through aperture 306 is facilitated by a curved inner surface 322 of tubular member 292 at the distal end thereof (FIG. 28). FIG. 34 is provided to depict a manufacturing process for a partially flexible thrombectomy device as described herein. The process is, however, also applicable to completely rigid thrombectomy devices. A cutting element 324 including a rigid distal tip 326 and a flexible body 328 is inserted through a flexible outer tube 330. A rigid sleeve 332 is then attached to an outer surface of tube 330 and to another flexible tube 334 via annular welds or coupling elements 336 and 338. Sleeve 332 has a clot intake opening or port 340, while tip 326 of cutting element 324 is provided with a cutting edge 342. FIGS. 35 and 36 depict a thrombectomy device with a cross-sectionally D-shaped cutter element 342 provided with a cutting window 344. A wall 346 of cutter element 342 divides a lumen (not designated) of a tubular member 348 into a suction channel 350 and an irrigation or positive pressurization channel 352. The cutter of FIGS. 35 and 36 may be reciprocated, or alternatively, rotated. In a rotating mode of operation, cutter element 342 remains longitudinally fixed relative to tubular member 348. As window 344 becomes aligned with an intake port (not shown) in tubular member 348, a negative pressure in suction channel 350 draws a clot or other organic material into the tubular member through the intake port. Further rotation of cutter element 342 closes the intake port and simultaneously cuts off a portion of the clot or other material for subsequent removal or ejection via the tubular member. As illustrated in FIG. 37, a thrombectomy device may include a tubular member 354 through which a hollow eccentrically disposed irrigation tube 356 slidably extends. At a distal end, irrigation tube or drive rod 356 is provided with a cap 358 which closes off a clot-intake port or opening 360 upon a shifting of the irrigation tube in the proximal direction, as indicated by an arrow 362. Upon the closure of intake port 360 by cap 358, fluid pressure from tube 356 may be built up in tubular member 354 to eject any stuck clot material. Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. For example, other configurations of the suction, irrigation and clot-intake ports and other clot cutting techniques will occur readily to those of ordinary skill in the art. These alternate configurations and cutting tools are considered to be equivalent to those disclosed specifically herein. It is to be noted that a pressure sensor or other detector may be operatively connected to a suction line extending to the suction port of the clot removal device. Upon sensing a decrease in pressure, owing to the drawing of material into the clot intake port, the sensor automatically triggers a cutting and ejection phase of an operating cycle. Accordingly, the entire process may be automated (see discussion above with respect to FIG. 1 et seq.). A device in accordance with the present invention may be used in internal organs other than blood vessels or vascular prostheses to remove material other than blood clots. Inside the vascular system, the device may be used to remove plaque and other vascular debris. The device may alternatively be used to remove tumorous growths and other undesirable tissues. In addition, the device may be used to remove organic material which has been macerated by another instrument or technique. In that event, the suction and tube pressurization procedures described herein, including the closing of the intake port to enable or enhance tube pressurization, can be used without the cutting operation, to remove the macerated material from a patient. It is to be observed that an implanted prosthetic device such as a vascular bypass made of synthetic materials is considered to be an organ for purposes of the present invention. It is to be further observed that the cutting edges of cutter elements disclosed herein may be serrated or toothed, for facilitating the cutting operation. It is also possible to provide a two-piece instrument with clot severing and ejection mechanisms in accordance with the present invention. In a two-piece instrument, two tubular parts are inserted into a patient at different locations so that the distal ends of the parts meet each other and can be connected inside the patient. Of course, one or more guidewires may be necessary, as well as locking elements at the distal ends of the two tubular parts for coupling the parts to form a single member. Accordingly, it is to be understood that the drawings and descriptions herein are profferred by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

A pull push device for removing a clot. The device includes an elongate tubular member having a suction port and an irrigation or fluid pressurization port respectively connectable to a vacuum source and a pressurizable fluid reservoir. The tubular member also has a clot intake port positionable through a patient's skin inside a clogged vascular vessel. The vacuum source enables clot suction into the clot intake port for severing while liquid pressure supplies fluid for clot ejection and device clearance. A single piece rotating or reciprocating cutter and intake closure component is mounted inside the tubular member for closing the clot intake port upon each small vacuum assisted severing of clot mass by the cutting element. By simultaneously severing the clot and closing the intake port by the closure component, the device automatically converts from a suction to a pressure mode, thus ejecting any clot through the suction port. The ordered and continual suck, cut, push, pull tandem ejection system is aided by an automatic anticlogging mechanism which is operative when a sucked clot obstructs suction through the tubular member. This self-limiting feature closes off further suction and ends the process of clot intake. Only after window closure and clot ejection has occurred is vacuum restored to the intake port so that more clot may be sucked into the device for processing.

CROSS REFERENCES TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 11/072,027, now U.S. Pat. No. ______. U.S. patent application Ser. No. 11/072,027 application is a continuation-in-part of U.S. patent application Ser. No. 10/934,596, now U.S. Pat. No. 7,031,839, and a continuation-in-part of U.S. patent application Ser. No. 10/867,619 filed on Jun. 15, 2004. U.S. patent application Ser. No. 11/072,027 application is also related to a concurrently filed U.S. patent application Ser. No. 11/072,570, now U.S. Pat. No. ______. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention is related to the field of electromagnetic induction well logging for determining the resistivity of earth formations penetrated by wellbores. More specifically, the invention addresses the problem of using multicomponent induction measurements in an anisotropic formation for reservoir navigation using determined distances to an interface in the earth formation. [0004] 2. Description of the Related Art [0005] To obtain hydrocarbons such as oil and gas, well boreholes are drilled by rotating a drill bit attached at a drill string end. The drill string may be a jointed rotatable pipe or a coiled tube. Boreholes may be drilled vertically, but directional drilling systems are often used for drilling boreholes deviated from vertical and/or horizontal boreholes to increase the hydrocarbon production. Modern directional drilling systems generally employ a drill string having a bottomhole assembly (BHA) and a drill bit at an end thereof that is rotated by a drill motor (mud motor) and/or the drill string. A number of downhole devices placed in close proximity to the drill bit measure certain downhole operating parameters associated with the drill string. Such devices typically include sensors for measuring downhole temperature and pressure, and tool azimuth and inclination. Also used are measuring devices such as a resistivity-measuring device to determine the presence of hydrocarbons and water. Additional downhole instruments, known as measurement-while-drilling (MWD) or logging-while-drilling (LWD) tools, are frequently attached to the drill string to determine formation geology and formation fluid conditions during the drilling operations. [0006] Boreholes are usually drilled along predetermined paths and proceed through various formations. A drilling operator typically controls the surface-controlled drilling parameters during drilling operations. These parameters include weight on bit, drilling fluid flow through the drill pipe, drill string rotational speed (r.p.m. of the surface motor coupled to the drill pipe) and the density and viscosity of the drilling fluid. The downhole operating conditions continually change and the operator must react to such changes and adjust the surface-controlled parameters to properly control the drilling operations. For drilling a borehole in a virgin region, the operator typically relies on seismic survey plots, which provide a macro picture of the subsurface formations and a pre-planned borehole path. For drilling multiple boreholes in the same formation, the operator may also have information about the previously drilled boreholes in the same formation. [0007] In development of reservoirs, it is common to drill boreholes at a specified distance from fluid contacts within the reservoir or from bed boundaries defining the top of a reservoir. In order to maximize the amount of recovered hydrocarbons from such a borehole, the boreholes are commonly drilled in a substantially horizontal orientation in close proximity to the oil water contact, but still within the oil zone. U.S. Pat. RE35386 to Wu et al., having the same assignee as the present application and the contents of which are fully incorporated herein by reference, teaches a method for detecting and sensing boundaries in a formation during directional drilling so that the drilling operation can be adjusted to maintain the drillstring within a selected stratum is presented. [0008] The method comprises the initial drilling of an offset well from which resistivity of the formation with depth is determined. This resistivity information is then modeled to provide a modeled log indicative of the response of a resistivity tool within a selected stratum in a substantially horizontal direction. A directional (e.g., horizontal) well is thereafter drilled wherein resistivity is logged in real time and compared to that of the modeled horizontal resistivity to determine the location of the drill string and thereby the borehole in the substantially horizontal stratum. From this, the direction of drilling can be corrected or adjusted so that the borehole is maintained within the desired stratum. The resistivity sensor typically comprises a transmitter and a plurality of sensors. Measurements may be made with propagation sensors that operate in the 400 kHz and higher frequency range. [0009] A limitation of the method and apparatus used by Wu is that resistivity sensors are responsive to oil/water contacts for relatively small distances, typically no more than 5 m; at larger distances, conventional propagation tools are not responsive to the resistivity contrast between water and oil. One solution that can be used in such a case is to use an induction logging tool that typically operates in frequencies between 10 kHz and 50 kHz. U.S. Pat. No. 6,308,136 to Tabarovsky et al. having the same assignee as the present application and the contents of which are fully incorporated herein by reference, teaches a method of interpretation of induction logs in near horizontal boreholes and determining distances to boundaries in proximity to the borehole. [0010] U.S. Pat. No. 5,884,227, issued to Rabinovich et al., having the same assignee as the present invention, is a method of adjusting induction receiver signals for skin effect in an induction logging instrument including a plurality of spaced apart receivers and a transmitter generating alternating magnetic fields at a plurality of frequencies. The method includes the steps of extrapolating measured magnitudes of the receiver signals at the plurality of frequencies, detected in response to alternating magnetic fields induced in media surrounding the instrument, to zero frequency. A model of conductivity distribution of the media surrounding the instrument is generated by inversion processing the extrapolated magnitudes. Rabinovich works equally well under the assumption that the induction tool device has perfect conductivity or zero conductivity. In a measurement-while-drilling device, this assumption does not hold. [0011] The Multi-frequency focusing (MFF) of Rabinovich is an efficient way of increasing depth of investigation for electromagnetic logging tools. It is being successfully used in wireline applications, for example, in processing and interpretation of induction data. MFF is based on specific assumptions regarding behavior of electromagnetic field in frequency domain. For MWD tools mounted on metal mandrels, those assumptions are not valid. Particularly, the composition of a mathematical series describing EM field at low frequencies changes when a very conductive body is placed in the vicinity of sensors. Only if the mandrel material were perfectly conducting, would MFF of Rabinovich be applicable. [0012] U.S. patent application Ser. No. 10/295,969 of Tabarovsky et al. (“the Tabarovsky '969 application”), now U.S. Pat. No. 6,906,521, having the same assignee as the present invention and the contents of which are fully incorporated herein by reference, teaches a modification of the method of Rabinovich that applies MFF to induction measurements made with transmitters and receivers on a mandrel of finite conductivity. U.S. patent application Ser. No. 10/934,596 of Tabarovsky et al. (“the Tabarovsky '596 application), now U.S. Pat. No. 7,031,839 having the same assignee as the present application and the contents of which are fully incorporated herein by reference teaches methods for the optimum design of the MFF acquisition system for deep resistivity measurements in the earth. The frequencies at which the measurements are made are selected based on one or more criteria, such as reducing an error amplification resulting from the MFF, increasing an MFF signal voltage, or increasing an MFF focusing factor. In one embodiment of the invention, the tool has a portion with finite non-zero conductivity. The Tabarovsky '596 application teaches design of the MFF system for both wireline and MWD applications. In the case of MWD applications, the Tabarovsky 596 application also addresses the issue of reservoir navigation. [0013] The teachings discussed above are all directed towards the use of conventional induction tools in which the transmitter and receiver coils are parallel to the tool axis. Such a tool may be referred to as the HDIL tool. U.S. patent application Ser. No. 10/373,365 of Merchant et al., published as U.S.20030229449 having the same assignee as the present application and the contents of which are incorporated herein by reference teaches the use of multicomponent induction logging tools and measurements as an indicator of a distance to a bed boundary and altering the drilling direction based on such measurements. In conventional induction logging tools, the transmitter and receiver antenna coils have axes substantially parallel to the tool axis (and the borehole). The multicomponent tool of Merchant et al. has three transmitters and three receivers, with coils oriented in the x-, y- and z-directions and may be referred to hereafter as the 3DEX™ tool. [0014] The teachings of Merchant are show that the 3DEX™ measurements are very useful in determination of distances to bed boundaries (and in reservoir navigation), Merchant discusses the reservoir navigation problem in terms of measurements made with the borehole in a substantially horizontal configuration (parallel to the bed boundary). This may not always be the case in field applications where the borehole is approaching the bed boundary at an angle. In a situation where the borehole is inclined, then the multicomponent measurements, particularly the cross-component measurements, are responsive to both the distance to the bed boundary and to the anisotropy in the formation. In anisotropic formations, determination of a relative dip angle between the borehole and the anisotropy direction may be used for navigation. [0015] U.S. Pat. No. 6,643,589 to Zhang et al., having the same assignee as the present application and the contents of which are incorporated herein by reference, teaches the inversion of measurements made by a multicomponent logging tool in a borehole to obtain horizontal and vertical resistivities and formation dip and azimuth angles. The inversion is performed using a generalized Marquardt-Levenberg method. Knowledge of the relative dip angle could be used for reservoir navigation in anisotropic media. However, the method of Zhang, while extremely useful for wireline applications, may not be computationally fast enough to provide the angles in real time that are necessary for reservoir navigation. [0016] U.S. application Ser. No. 10/186,927 of Xiao et al. (now U.S. Pat. No. 6,885,947), having the same assignee as the present invention and the contents of which are incorporated herein by reference, teaches the determination of a relative dip angle using HDIL and 3DEX™ measurements. Compared to Zhang, the method of Xiao has the added drawback of requiring HDIL measurements. In addition, it is not clear that the dip angles may be determined in real time for reservoir navigation. [0017] There is a need for a method of processing multi-frequency data acquired with real MWD tools having finite non-zero conductivity to get estimates of relative dip angles that may be used in real time for reservoir navigation. The present invention satisfies this need. SUMMARY OF THE INVENTION [0018] One embodiment of the present invention is a method of evaluating an earth formation. A borehole is drilled in the earth formation using a bottomhole assembly (BHA) having a drillbit. A logging tool on the BHA is used for obtaining multicomponent resistivity measurements at a plurality of frequencies: the multicomponent measurements depend at least in part on a horizontal resistivity and a vertical resistivity of the earth formation. A distance to an interface in the earth formation is determined, the determination accounting for a finite, nonzero conductivity of a body of the logging tool. The direction of drilling of the BHA is controlled based on the determined distance. Determining the distance may be based applying a multifrequency focusing to the multicomponent measurements at the plurality of frequencies, followed by determination of two or more fundamental modes from the focused measurements. The fundamental modes are used to derive the horizontal and vertical conductivities that are then used as a distance indicator. The interface may be a fluid contact or a bed boundary. [0019] Another embodiment of the invention is an apparatus for evaluating an earth formation. The apparatus includes a bottomhole assembly (BHA) having a drillbit which drills a borehole in the earth formation. A logging tool on the BHA obtains multicomponent resistivity measurements at a plurality of frequencies, the multicomponent measurements depending at least in part on a horizontal resistivity and a vertical resistivity of the earth formation. One or more processors is used to determine from the multicomponent measurements a distance to an interface in the earth formation, the determination accounting for a finite, nonzero conductivity of a body of the logging tool, and to control a direction of drilling of the BHA based on the determined distance. Determination of the distance may be based on application of multifrequency focusing by the processor(s) and separation of the focused results into two or more fundamental modes. Horizontal and vertical resistivities are determined from the fundamental modes and may be used as a distance indicator to the interface. The interface may be a fluid interface or may be a bed boundary. [0020] Another embodiment of the invention is a computer readable medium for use with an apparatus conveyed in an earth formation. The apparatus includes a bottomhole assembly (BHA) having a drillbit which drills a borehole in the earth formation. A logging tool on the BHA obtains multicomponent resistivity measurements at a plurality of frequencies, the multicomponent measurements depending at least in part on a horizontal resistivity and a vertical resistivity of the earth formation. The medium includes instructions which when executed by a processor determine a distance to an interface based on the multicomponent measurements, the determination accounting for a finite, nonzero conductivity of a body of the logging tool. Additional instructions control a direction of drilling of the BHA based on the determined distance. The instructions may enable application of multifrequency focusing, and determining at least two fundamental modes. The medium may be a ROM, an EPROM, an EAROM, a Flash Memory, and/or an Optical disk. BRIEF DESCRIPTION OF THE DRAWINGS [0021] The present invention is best understood with reference to the accompanying figures in which like numerals refer to like elements and in which: [0022] FIG. 1 (Prior Art) shows drilling assembly suitable for use with the method of the present invention; [0023] FIG. 1A (prior art) shows an induction tool conveyed within a formation layer; [0024] FIG. 2 (prior art) illustrates an exemplary multi-array induction tool; [0025] FIG. 3 (prior art) shows responses of a induction tool with a perfectly conducting mandrel; [0026] FIG. 4 (prior art) shows the effect of finite mandrel conductivity; [0027] FIG. 5 (prior art) shows the difference between finite conducting mandrel and perfect conducting mandrel at several frequencies; [0028] FIG. 6 (prior art) shows the effect of wireline multi-frequency focusing processing of data acquired with perfectly conducting mandrel and finite conducting mandrel; [0029] FIG. 7 (prior art) shows the convergence of the method of the present invention with the increased number of expansion terms; [0030] FIG. 8 (prior art) shows multi-frequency focusing of the finite conducting mandrel response; [0031] FIG. 9 shows an MWD tool in the context of reservoir navigation; [0032] FIG. 10 (prior art) shows the configuration of coils of a multicomponent induction logging tool; [0033] FIG. 11 shows a schematic cross section of a layered earth with a deviated borehole; [0034] FIG. 12 is a flow chart illustrating one embodiment of the present invention; and [0035] FIG. 13 is a flow chart illustrating a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0036] FIG. 1 shows a schematic diagram of a drilling system 10 with a drillstring 20 carrying a drilling assembly 90 (also referred to as the bottom hole assembly, or “BHA”) conveyed in a “wellbore” or “borehole” 26 for drilling the wellbore. The drilling system 10 includes a conventional derrick 11 erected on a floor 12 which supports a rotary table 14 that is rotated by a prime mover such as an electric motor (not shown) at a desired rotational speed. The drillstring 20 includes a tubing such as a drill pipe 22 or a coiled-tubing extending downward from the surface into the borehole 26 . The drillstring 20 is pushed into the wellbore 26 when a drill pipe 22 is used as the tubing. For coiled-tubing applications, a tubing injector, such as an injector (not shown), however, is used to move the tubing from a source thereof, such as a reel (not shown), to the wellbore 26 . The drill bit 50 attached to the end of the drillstring breaks up the geological formations when it is rotated to drill the borehole 26 . If a drill pipe 22 is used, the drillstring 20 is coupled to a drawworks 30 via a Kelly joint 21 , swivel 28 , and line 29 through a pulley 23 . During drilling operations, the drawworks 30 is operated to control the weight on bit, which is an important parameter that affects the rate of penetration. The operation of the drawworks is well known in the art and is thus not described in detail herein. [0037] During drilling operations, a suitable drilling fluid 31 from a mud pit (source) 32 is circulated under pressure through a channel in the drillstring 20 by a mud pump 34 . The drilling fluid passes from the mud pump 34 into the drillstring 20 via a desurger (not shown), fluid line 28 and Kelly joint 21 . The drilling fluid 31 is discharged at the borehole bottom 51 through an opening in the drill bit 50 . The drilling fluid 31 circulates uphole through the annular space 27 between the drillstring 20 and the borehole 26 and returns to the mud pit 32 via a return line 35 . The drilling fluid acts to lubricate the drill bit 50 and to carry borehole cutting or chips away from the drill bit 50 . A sensor S 1 preferably placed in the line 38 provides information about the fluid flow rate. A surface torque sensor S 2 and a sensor S 3 associated with the drillstring 20 respectively provide information about the torque and rotational speed of the drillstring. Additionally, a sensor (not shown) associated with line 29 is used to provide the hook load of the drillstring 20 . [0038] In one embodiment of the invention, the drill bit 50 is rotated by only rotating the drill pipe 22 . In another embodiment of the invention, a downhole motor 55 (mud motor) is disposed in the drilling assembly 90 to rotate the drill bit 50 and the drill pipe 22 is rotated usually to supplement the rotational power, if required, and to effect changes in the drilling direction. [0039] In the embodiment of FIG. 1 , the mud motor 55 is coupled to the drill bit 50 via a drive shaft (not shown) disposed in a bearing assembly 57 . The mud motor rotates the drill bit 50 when the drilling fluid 31 passes through the mud motor 55 under pressure. The bearing assembly 57 supports the radial and axial forces of the drill bit. A stabilizer 58 coupled to the bearing assembly 57 acts as a centralizer for the lowermost portion of the mud motor assembly. [0040] In one embodiment of the invention, a drilling sensor module 59 is placed near the drill bit 50 . The drilling sensor module contains sensors, circuitry and processing software and algorithms relating to the dynamic drilling parameters. Such parameters preferably include bit bounce, stick-slip of the drilling assembly, backward rotation, torque, shocks, borehole and annulus pressure, acceleration measurements and other measurements of the drill bit condition. A suitable telemetry or communication sub 72 using, for example, two-way telemetry, is also provided as illustrated in the drilling assembly 90 . The drilling sensor module processes the sensor information and transmits it to the surface control unit 40 via the telemetry system 72 . [0041] The communication sub 72 , a power unit 78 and an MWD tool 79 are all connected in tandem with the drillstring 20 . Flex subs, for example, are used in connecting the MWD tool 79 in the drilling assembly 90 . Such subs and tools form the bottom hole drilling assembly 90 between the drillstring 20 and the drill bit 50 . The drilling assembly 90 makes various measurements including the pulsed nuclear magnetic resonance measurements while the borehole 26 is being drilled. The communication sub 72 obtains the signals and measurements and transfers the signals, using two-way telemetry, for example, to be processed on the surface. Alternatively, the signals can be processed using a downhole processor in the drilling assembly 90 . [0042] The surface control unit or processor 40 also receives signals from other downhole sensors and devices and signals from sensors S 1 -S 3 and other sensors used in the system 10 and processes such signals according to programmed instructions provided to the surface control unit 40 . The surface control unit 40 displays desired drilling parameters and other information on a display/monitor 42 utilized by an operator to control the drilling operations. The surface control unit 40 preferably includes a computer or a microprocessor-based processing system, memory for storing programs or models and data, a recorder for recording data, and other peripherals. The control unit 40 is preferably adapted to activate alarms 44 when certain unsafe or undesirable operating conditions occur. [0043] FIG. 1A shows a typical configuration of a metal mandrel 101 within a borehole 105 . Two formation layers, an upper formation layer 100 and a lower formation layer 110 , are shown adjacent to the borehole 105 . A prominent invasion zone 103 is shown in the upper formation layer. [0044] FIG. 2 shows a generic tool for evaluation of MFF in MWD applications (MFFM). A transmitter, T, 201 is excited at a plurality of RF frequencies f 1 , . . . , f n . For illustrative purposes, eight frequencies are considered: 100, 140, 200, 280, 400, 560, 800, and 1600 kHz. A plurality of axially-separated receivers, R 1 , . . . , R m , 205 are positioned at distances, L 1 , . . . , L m , from transmitter. For illustrative purposes, distances of the seven receivers are chosen as L=0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5 m. Transmitter 201 and receivers 205 enclose a metal mandrel 210 . In all examples, the mandrel radius is 8 cm, the transmitter radius is 9 cm, and the radius of the plurality of receivers is 9 cm. Data is obtained by measuring the responses of the plurality of receivers 205 to an induced current in the transmitter 201 . Such measured responses can be, for example, a magnetic field response. The mandrel conductivity may be assumed perfect (perfectly conducting mandrel, PCM) or finite (finite conductivity mandrel, FCM). In the method of the present invention, obtained data is corrected for the effects of the finite conductivity mandrel, such as skin effect, for example, in order to obtain data representative of an induction tool operated in the same manner, having an infinite conductivity. Corrected data can then be processed using multi-frequency focusing. Typical results of multi-frequency focusing can be, for instance, apparent conductivity. A calculated relationship can obtain value of conductivity, for example, when frequency is equal to zero. Any physical quantity oscillating in phase with the transmitter current is called real and any measurement shifted 90 degrees with respect to the transmitter current is called imaginary, or quadrature. [0045] Obtaining data using a nonconducting mandrel is discussed in Rabinovich et al., U.S. Pat. No. 5,884,227, having the same assignee as the present invention, the contents of which are fully incorporated herein by reference. When using a nonconducting induction measurement device, multi-frequency focusing (MFF) can be described using a Taylor series expansion of EM field frequency. A detailed consideration for MFFW (wireline MFF applications) can be used. Transmitter 201 , having a distributed current J(x,y,z) excites an EM field with an electric component E(x,y,z) and a magnetic component H(x,y,z). Induced current is measured by a collection of coils, such as coils 205 . [0046] An infinite conductive space has conductivity distribution σ(x,y,z), and an auxiliary conductive space (‘background conductivity’) has conductivity σ 0 (x,y,z). Auxiliary electric dipoles located in the auxiliary space can be introduced. For the field components of these dipoles, the notation e n (P 0 ,P), h n (P 0 ,P), where n stands for the dipole orientation, P and P 0 , indicate the dipole location and the field measuring point, respectively. The electric field E(x,y,z) satisfies the following integral equation (see L. Tabarovsky, M. Rabinovich, 1998, Real time 2-D inversion of induction logging data. Journal of Applied Geophysics, 38, 251-275.): E ⁡ ( P 0 ) = E 0 ⁡ ( P 0 ) + ∫ - ∞ + ∞ ⁢ ∫ - ∞ + ∞ ⁢ ∫ - ∞ + ∞ ⁢ ( σ - σ 0 ) ⁢ e ^ ⁡ ( P 0 | P ) ⁢ E ⁡ ( P ) ⁢   ⁢ ⅆ x ⁢   ⁢ ⅆ y ⁢   ⁢ ⅆ z . ( 1 ) where E 0 (P 0 ) is the field of the primary source J in the background medium σ 0 . The 3×3 matrix e(P 0 \P) represents the electric field components of three auxiliary dipoles located in the integration point P. [0047] The electric field, E, may be expanded in the following Taylor series with respect to the frequency: E = ∑ k = 2 k = ∞ ⁢ u k / 2 ⁡ ( - ⅈω ) k / 2 ⁢ ⁢ u 3 / 2 = 0 ( 2 ) The coefficient u 5/2 corresponding to the term ω 5/2 is independent of the properties of a near borehole zone, thus u 5/2 =u 5/2 0 . This term is sensitive only to the conductivity distribution in the undisturbed formation ( 100 ) shown in FIG. 1A . [0048] The magnetic field can be expanded in a Taylor series similar to Equation (2): H = ∑ k = 0 k = ∞ ⁢ s k / 2 ⁡ ( - ⅈω ) k / 2 ⁢ ⁢ s 1 / 2 = 0 ( 3 ) In the term containing ω 3/2 , the coefficient s 3/2 depends only on the properties of the background formation, in other words s 3/2 =s 3/2 0 . This fact is used in multi-frequency processing. The purpose of the multi-frequency processing is to derive the coefficient u 5/2 if the electric field is measured, and coefficient s 3/2 if the magnetic field is measured. Both coefficients reflect properties of the deep formation areas. [0049] If an induction tool consisting of dipole transmitters and dipole receivers generates the magnetic field at m angular frequencies, ω 1 , ω 2 , . . . , ω m , the frequency Taylor series for the imaginary part of magnetic field has the following form: Im ⁡ ( H ) = ∑ k = 1 k = ∞ ⁢ s k / 2 ⁢ ω k / 2 ⁢ ⁢ s 2 ⁢ j = 0 ; j = 1 , 2 , … ⁢   , . ( 4 ) where s k/2 are coefficients depending on the conductivity distribution and the tool's geometric configuration, not on the frequency. Rewriting the Taylor series for each measured frequency obtains: ( H ⁡ ( ω 1 ) H ⁡ ( ω 2 ) ⋯ ⋯ ⋯ H ⁡ ( ω m - 1 ) H ⁡ ( ω m ) ) = ( ω ω 1 3 / 2 ω 1 5 / 2 ⋯ ⋯ ⋯ ω 1 n / 2 ω ω 2 3 / 2 ω 2 5 / 2 ⋯ ⋯ ⋯ ω 2 n / 2 ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ω ω m - 1 3 / 2 ω m - 1 5 / 2 ⋯ ⋯ ⋯ ω m - 1 n / 2 ω ω m 3 / 2 ω m 5 / 2 ⋯ ⋯ ⋯ ω m n / 2 ) ⁢ ( s 1 s 3 / 2 s 5 / 2 ⋯ ⋯ ⋯ s n / 2 ) . ( 5 ) Solving the system of Equations (5), it is possible to obtain the coefficient s 3/2 . It turns out that the expansion is the same for a perfectly conducting mandrel and a non-conducting mandrel. [0050] FIG. 3 shows the results of MFF for a perfectly conducting mandrel. In FIG. 3 , borehole radius is 11 cm. MFF, as performed based on Eq. (5) and Eq. (3) (MFFW) produces the expected results. Data sets 301 and 305 are shown for a formation having 0.4 S/m and 0.1 S/m respectively, with no borehole effects. Data set 303 is shown for a formation having 0.4 S/m and a borehole having mud conductivity 10 S/m and 0.1 S/m. Apparent conductivity data, processed using MFFW, do not depend on borehole parameters or tool length. Specifically, apparent conductivity equals to the true formation conductivity. The present invention can be used to correct from an FCM tool to a PCM with the same sensor arrangements. [0051] Fundamental assumptions enabling implementing MFFW are based on the structure of the Taylor series, Eq. (2) and Eq. (3). These assumptions are not valid if a highly conductive body is present in the vicinity of sensors (e.g., mandrel of MWD tools). The present invention uses an asymptotic theory that enables building MFF for MWD applications (MFFM). [0052] The measurements from a finite conductivity mandrel can be corrected to a mandrel having perfect conductivity. Deriving a special type of integral equations for MWD tools enables this correction. The magnetic field measured in a typical MWD electromagnetic tool may be described by H α ⁡ ( P ) = H α 0 ⁡ ( P ) + β ⁢ ∫ S ⁢ { H → M ⁢   ⁢ α ⁢ h → ⁢   } ⁢ ⅆ S ( 6 ) where H α (P) is the magnetic field measure along the direction α (α-component), P is the point of measurement, H α 0 (P) is the α-component of the measured magnetic field given a perfectly conducting mandrel, S is the surface of the tool mandrel, β=1/√{square root over (−iωμσ c )}, where ω and μ are frequency and magnetic permeability, and ma h is the magnetic field of an auxiliary magnetic dipole in a formation where the mandrel of a finite conductivity is replaced by an identical body with a perfect conductivity. The dipole is oriented along α-direction. At high conductivity, β is small. [0053] Equation (6) is evaluated using a perturbation method, leading to the following results: H α = ∑ i = 0 i = ∞ ⁢ H α ( i ) ( 7 ) H α ( 0 ) = H α 0 ( 8 ) H α ( i ) = β ⁢ ∫ S ⁢ { H → M ⁢   ⁢ α ( i - 1 ) ⁢ h → ⁢   } ⁢ ⅆ S ⁢ ⁢ i = 1 , … ⁢   , ∞ ( 9 ) In a first order approximation that is proportional to the parameter β: H α ( 1 ) = β ⁢ ∫ S ⁢ { H → M ⁢   ⁢ α ( 0 ) ⁢ h → ⁢   } ⁢ ⅆ S = β ⁢ ∫ S ⁢ { H → 0 M ⁢   ⁢ α ⁢ h → ⁢   } ⁢ ⅆ S ( 10 ) The integrand in Eq. (10) is independent of mandrel conductivity. Therefore, the integral on the right-hand side of Eq. (10) can be expanded in wireline-like Taylor series with respect to the frequency, as: ∫ S ⁢ { H → 0 M ⁢   ⁢ α ⁢ h → ⁢   } ⁢ ⅆ S ≈ b 0 + ( - ⅈωμ ) ⁢ b 1 + ( - ⅈωμ ) 3 / 2 ⁢ b 3 / 2 + ( - ⅈωμ ) 2 ⁢ b 2 + … ( 11 ) Substituting Eq. (11) into Eq. (10) yields: H α ( 1 ) = 1 σ c ⁢ ( b 0 ( - ⅈωμ ) 1 / 2 + ( - ⅈωμ ) 1 / 2 ⁢ b 1 + ( - ⅈωμ ) ⁢ b 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b 2 + … ) ( 12 ) [0054] Further substitution in Eqs. (7), (8), and (9) yield: H α ≈ H α 0 + 1 σ ⁢ (   ⁢ b   ⁢ 0   ⁢ ( ⅈωμ ) 1 / 2 + ( - ⅈωμ ) 1 / 2 ⁢ b   ⁢ 1 + ( - ⅈωμ ) ⁢ b   ⁢ 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b   ⁢ 2 + … ⁢   ) ( 13 ) Considering measurement of imaginary component of the magnetic field, Equation (5), modified for MWD applications has the following form: ( H ⁡ ( ω 1 ) H ⁡ ( ω 2 ) ⋮ ⋮ ⋮ H ⁡ ( ω m - 1 ) H ⁡ ( ω m ) ) = ( ω 1 1 / 2 ω 1 1 ω 1 3 / 2 ω 1 5 / 2 ⋮ ⋮ ⋮ ω 1 n / 2 ω 2 1 / 2 ω 2 1 ω 2 3 / 2 ω 2 5 / 2 ⋮ ⋮ ⋮ ω 2 n / 2 ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ω m - 1 1 / 2 ω m - 1 1 ω m - 1 3 / 2 ω m - 1 5 / 2 ⋮ ⋮ ⋮ ω m - 1 n / 2 ω m 1 / 2 ω m 1 ω m 3 / 2 ω m 5 / 2 ⋮ ⋮ ⋮ ω m n / 2 ) ⁢ ( s 1 / 2 s 1 s 3 / 2 s 5 / 2 ⋮ ⋮ ⋮ s n / 2 ) . ( 14 ) Details are given in the Appendix. The residual signal (third term) depends on the mandrel conductivity, but this dependence is negligible due to very large conductivity of the mandrel. Similar approaches may be considered for the voltage measurements. [0055] In Eq. (13), the term H α 0 describes effect of PCM, and the second term containing parentheses describes the effect of finite conductivity. At relatively low frequencies, the main effect of finite conductivity is inversely proportional to ω 1/2 and σ 1/2 : H α ≈ H α 0 + 1 σ c ⁢ ( b 0 ( - ⅈωμ ) 1 / 2 ) ( 15 ) [0056] FIGS. 4 and 5 confirm the validity of Equation (15). Values shown in FIG. 4 are calculated responses of PCM and FCM tools in a uniform formation with conductivity of 0.1 S/m with a transmitter current of 1 Amp. FIG. 4 shows three pairs of data curves: 401 and 403 ; 411 and 413 ; and 421 and 423 . Within each pairing, the differences of the individual curves are due only to the conductivity of the mandrel. Curves 401 and 403 are measured using a receiver separated from the transmitter by 0.3 m. Curve 401 is measured with a mandrel having 5.8*10 7 S/m and Curve 403 assumes perfect conductivity. Similarly, curves 411 and 413 are measured using receiver separated from the transmitter by 0.9 m. Curve 411 is measured with a mandrel having 5.8*10 7 S/m and Curve 413 assumes perfect conductivity. Lastly, curves 421 and 423 are measured using receiver separated from the transmitter by 1.5 m. Curve 421 is measured with a mandrel having 5.8*10 7 S/m and Curve 423 assumes perfect conductivity. Curves 401 , 411 , 421 , indicative of the curves for FCM diverge from curves 403 , 413 , and 423 , respectively, in the manner shown in Eq. (15), (i.e., 1/ω 1/2 divergence). [0057] FIG. 5 shows that, as a function of frequency, the difference of FCM and PCM responses follows the rule of 1/ω 1/2 with a very high accuracy. The scale value represents the difference in values between responses obtained for PCM and FCM (PCM-FCM in A/m) at several frequencies. Actual formation conductivity is 0.1 S/m. Curve 501 demonstrates this difference for a receiver-transmitter spacing of 0.3 m. Curves 503 and 505 demonstrate this difference for receiver transmitter spacing of 0.9 m and 1.5 m, respectively. [0058] FIG. 6 shows the inability of prior methods of MFFW to correct data acquired from FCM to that of PCM. The results are from conductivity measurements in a uniform space with conductivity of 0.1 S/m and in a space with conductivity 0.4 S/m containing a borehole. The borehole has a radius of 11 cm and a conductivity of 10 S/m. In both models, PCM and FCM responses are calculated and shown. In the FCM case, the mandrel conductivity is 2.8*10 7 S/m. As mentioned previously, MFFW is applicable to PCM tools. FIG. 6 shows the results of PCM ( 603 and 613 ) do not depend on tool spacing and borehole parameters. Obtained values for apparent conductivity are very close to the real formation conductivity. However, for an FCM tool, such as 601 and 611 , there is a dependence of MFFW on borehole parameters and tool length. The present invention addresses two of the major effects: the residual influence of the imperfect mandrel conductivity, and borehole effects. [0059] FIG. 7 illustrates convergence of the MFFM method as the number of terms in the expansion of Eq. (13) increases. Eight frequencies are used for the MFFM processing: 100, 140, 200, 280, 400, 460, 800, and 1600 kHz. Curve 703 shows results with an expansion having 3 terms. Curve 703 shows a large deviation from true conductivity at long tool length. Curves 704 , 705 , and 706 show results with an expansion having 4, 5, and 6 terms respectively. About 5 or 6 terms of the Taylor series are required for an accurate correction to true conductivity of 01 S/m. FIG. 7 also illustrates the ability of convergence regardless of tool length. Significantly, the factor k (equal to 15594 S/(Amp/m 2 )) for transforming magnetic field to conductivity is independent of spacing. [0060] FIG. 8 presents the results of the MFFM method in formations with and without borehole. Data points 801 and 805 show data received from formation having 0.4 S/m and 0.1 S/m respectively, with no borehole effects. Data points 803 shows data received from formation having conductivity 0.4 S/m with a borehole having 10 S/m. FIG. 8 shows that the effect of the borehole is completely eliminated by the method of the present invention. FIG. 8 also shows that after applying the method of the present invention, the value of the response data is independent of the spacing of the receivers. This second conclusion enables a tool design for deep-looking MWD tools using short spacing, further enabling obtaining data from the background formation ( 100 and 110 in FIG. 1A ) and reducing difficulties inherent in data obtained from an invasion zone ( 103 in FIG. 1A ). In addition, focused data are not affected by the near borehole environment. Results of FIG. 8 can be compared to FIG. 3 . [0061] The problem of selection of the frequencies is discussed in the Tabarovsky '596 application. To summarize the results therein, the frequency set ω 1 , ω 2 , . . . , ω m is optimal when the basis {right arrow over (ω)} 1/2 , {right arrow over (ω)} 1 , {right arrow over (ω)} 3/2 , . . . , {right arrow over (ω)} n/2 in eqn. (14) is as much linearly independent as possible. The measure of the linear independence of any basis is the minimal eigenvalue of the Gram matrix C of its vectors normalized to unity: C i , j = ( ω → p i  ω → p i  , ω → p j  ω → p j  ) . ( 17 ) The matrix C can be equivalently defined as follows: we introduce matrix B as {circumflex over (B)}=Â T Â   (18), where A is the matrix on the right hand side of eqn. (14). Normalizing the matrix C: C i , j = B i , j B i , i ⁢ B j , j . ( 19 ) [0062] Then maximizing the minimum singular value of matrix C will provide the most stable solution for which we are looking. In Tabarovsky '596, use is made of a standard SVD routine based on Golub's method to extract singular values of matrix C and the Nelder-Mead simplex optimization algorithm to search for the optimum frequency set. [0063] One application of the method of the present invention (with its ability to make resistivity measurements up to 20 m away from the borehole) is in reservoir navigation. In development of reservoirs, it is common to drill boreholes at a specified distance from fluid contacts within the reservoir. An example of this is shown in FIG. 9 where a porous formation denoted by 1205 a , 1205 b has an oil water contact denoted by 1213 . The porous formation is typically capped by a caprock such as 1203 that is impermeable and may further have a non-porous interval denoted by 1209 underneath. The oil-water contact is denoted by 1213 with oil above the contact and water below the contact: this relative positioning occurs due to the fact the oil has a lower density than water. In reality, there may not be a sharp demarcation defining the oil-water contact; instead, there may be a transition zone with a change from high oil saturation at the top to a high water saturation at the bottom. In other situations, it may be desirable to maintain a desired spacing from a gas-oil. This is depicted by 1214 in FIG. 9 . It should also be noted that a boundary such as 1214 could, in other situations, be a gas-water contact. [0064] In order to maximize the amount of recovered oil from such a borehole, the boreholes are commonly drilled in a substantially horizontal orientation in close proximity to the oil water contact, but still within the oil zone. U.S. Pat. RE35386 to Wu et al., having the same assignee as the present application and the contents of which are fully incorporated herein by reference, teaches a method for detecting and sensing boundaries in a formation during directional drilling so that the drilling operation can be adjusted to maintain the drillstring within a selected stratum is presented. The method comprises the initial drilling of an offset well from which resistivity of the formation with depth is determined. This resistivity information is then modeled to provide a modeled log indicative of the response of a resistivity tool within a selected stratum in a substantially horizontal direction. A directional (e.g., horizontal) well is thereafter drilled wherein resistivity is logged in real time and compared to that of the modeled horizontal resistivity to determine the location of the drill string and thereby the borehole in the substantially horizontal stratum. From this, the direction of drilling can be corrected or adjusted so that the borehole is maintained within the desired stratum. The configuration used in the Wu patent is schematically denoted in FIG. 9 by a borehole 1215 having a drilling assembly 1221 with a drill bit 1217 for drilling the borehole. The resistivity sensor is denoted by 1219 and typically comprises a transmitter and a plurality of sensors. [0065] The discussion above was based on MFFM for an induction tool in which the transmitter and receiver axes are coaxial with the tool axis ( FIG. 2 ). However, the MFFM method is equally applicable to other configurations of the transmitters and receivers. In particular, MFFM may also be used with the 3DEX™ tool of Baker Hughes Incorporated schematically illustrated in FIG. 10 . [0066] Shown in FIG. 10 is the configuration of transmitter and receiver coils in a the 3DEX™ induction logging instrument of Baker Hughes Incorporated. Such a logging instrument is an example of a transverse induction logging tool. Three orthogonal transmitters 1251 , 1253 and 1255 that are referred to as the T x , T z , and T y transmitters are shown (the z-axis is the longitudinal axis of the tool). Corresponding to the transmitters 1251 , 1253 and 1255 are receivers 1257 , 1259 and 1261 , referred to as the R x , R z , and R y receivers, for measuring the corresponding components (h xx , h yy , h zz ) of induced signals. In addition, cross-components are also measured. These are denoted by h xy , h xz , etc. For each component, the first index indicates the orientation of a transmitter and the second index specifies the orientation of a receiver. [0067] The use of a multicomponent induction tool is particularly important for reservoir navigation in anisotropic formations. In an anisotropic formation, the measurements made by a multiarray tool are responsive to both the horizontal and vertical resistivities of the formation. Multicomponent measurements are capable of distinguishing the effects of a bed boundary from anisotropy effects. [0068] FIG. 11 is a schematic illustration of the model used in the present invention. The subsurface of the earth is characterized by a plurality of layers 1302 , 1303 , . . . 1304 . The layers have thicknesses denoted by h 1 , h 2 , . . . h i . The horizontal and vertical resistivities in the layers are denoted by R h1 , R h2 , . . . R hi and R v1 , R v2 , . . . R vi respectively. Equivalently, the model may be defined in terms of conductivities (reciprocal of resistivity). The borehole is indicated by 1301 and associated with each of the layers are invaded zones in the vicinity of the borehole wherein borehole fluid has invaded the formation and altered is properties so that the electrical properties are not the same as in the uninvaded portion of the formation. The invaded zones have lengths L x01 , L x02 , . . . L x0i extending away from the borehole. The resistivities in the invaded zones are altered to values R x01 , R x02 , . . . R x0i . It should further be noted that the discussion of the invention herein may be made in terms of resistivities or conductivities (the reciprocal of resistivity). The z-component of the 3DEX™ tool is oriented along the borehole axis and makes an angle θ (not shown) with the normal to the bedding plane. For the purposes of reservoir navigation, the borehole axis is almost parallel to the bedding plane. Assuming that the anisotropy axis is normal to the bedding, determination of the inclination of the tool axis to the anisotropy axis can then be used for reservoir navigation. [0069] Determination of the relative dip angle is discussed next. The conductivity tensor of a horizontally layered formation with transversely anisotropic conductivity in each layer can be described using the matrix: σ ^ = ( σ h 0 0 0 σ h 0 0 0 σ v ) . ( 20 ) where σ h is the formation conductivity in the horizontal direction and σ v is the formation conductivity in the vertical direction. In contrast, at every depth, the multi-component induction logging tool acquires the following matrix of magnetic measurements H ^ = ( h xx h xy h xz h yx h yy h yz h zx h zy h zz ) ( 21 ) Not every element of the magnetic matrix Eq. (21) is non-zero—i.e. the tool may acquire less than 9 components. The actual number of transmitter-receiver components for which measurements are made may be designated by n 1 . The number n 1 is greater than 1, so that measurements are made with a plurality of transmitter-receiver pairs. At every logging depth, the magnetic matrix of Eq. (21) is a function of a formation conductivities σ h and σ v and two angles: relative dip θ (an angle between the formation normal and the tool axis) and relative rotation φ (the angle between the x-oriented sensor and the plane containing the tool axis and formation normal). As discussed in prior art (see, for example, Tabarovsky et al., 2001, “Measuring formation anisotropy using multi-frequency processing of transverse induction measurements”, SPE 71706), the relative dip θ and relative rotation angles φ can be further expressed using five quantities: formation dip and formation azimuth in the gravity reference system plus measured tool orientation angles DEV, RB, DAZ. A full description of the relation between the different angles is given in U.S. Pat. No. 6,643,589 to Zhang et al., having the same assignee as the present invention and the contents of which are fully incorporated herein by reference. It should be noted that the matrix of measurements given by eq. (21) can be obtained using x-, y- and z-oriented transmitters and receivers as shown in FIG. 10 . The same matrix can also be obtained by suitable rotation of coordinates of measurements made by other transmitter and receiver orientations, including those in which the transmitter and receiver axes are not orthogonal to each other or to the tool axis. In the present invention, when reference is made to the matrix of magnetic moments, it is intended to include data acquired with such non-orthogonal transmitter and receiver orientations. [0070] Generally, the magnetic matrix Eq. (21) cannot be diagonalized in a deviated well. Even in a simple model, such as for a thick anisotropic layer, the magnetic matrix has non-zero off-diagonal components. The magnetic matrix is of the form: H ^ = ( h xx 0 h xz 0 h yy 0 h zx 0 h zz ) . ( 22 ) MFFM as discussed above is applied to the magnetic matrix. In a general case, in a deviated well, the matrix of MFFM components has the following form: H ^ MFF = ( h ~ xx h ~ xy h ~ xz h ~ yx h ~ yy h ~ yz h ~ zx h ~ zy h ~ zz ) ( 23 ) The focused multifrequency components are obtained by applying MFFM to measurements made at, say n 2 different frequencies. The number n 2 must be greater than 1 in order to accomplish MFFM. Thus, the n 1 components noted above are measured at a plurality of frequencies. Typically, the response of the multi-component induction tool is strongly affected by the near-borehole environment. When MFFM is applied, these near-borehole effects can be eliminated. [0071] The matrix of MFFM components, Eq. (21), looks similar to the magnetic matrix of Eq. (19). Unlike single frequency measurements of Eq. (19), the tensor of the multi-frequency focused magnetic field of Eq. (21) can be diagonalized. It is shown below by a numerical example that the tensor of the focused multi-frequency magnetic field is diagonal in the coordinate system containing the formation normal: H ^ MFFM = ( ℏ xx 0 0 0 ℏ xx 0 0 0 ℏ zz ) . ( 22 ) An equation of the form given by Eq. (22) therefore comprises two fundamental modes xx and zz . Note that the off-diagonal terms are zero, and that the (x,x) and the (y,y) elements of the matrix are equal, just as they are in the conductivity tensor given by eq. (20). The value of the xx mode depends both on horizontal and vertical conductivity, while the zz mode depends only on horizontal conductivity. [0072] The measured MFFM components of Eq. (23) are expressed in terms of the principal components xx , zz of Eq. (24) and angles θ, φ using the relations: ( h ~ xx h ~ xy h ~ xz h ~ yx h ~ yy h ~ yz h ~ zx h ~ zy h ~ zz ) = ( c ϕ 2 ⁢ c θ 2 + s φ 2 c ϕ 2 ⁢ s φ 2 c φ ⁢ s φ - c φ ⁢ s φ ⁢ c θ 2 - c φ ⁢ s φ ⁢ s θ 2 c φ ⁢ c θ ⁢ c θ - c φ ⁢ c θ ⁢ s θ c φ ⁢ s φ - c φ ⁢ s φ ⁢ c θ 2 - c φ ⁢ s φ ⁢ s θ 2 s ϕ 2 ⁢ c θ 2 + c φ 2 s ϕ 2 ⁢ s φ 2 - s φ ⁢ c θ ⁢ s θ s φ ⁢ c θ ⁢ s θ c φ ⁢ c θ ⁢ s θ - c φ ⁢ c θ ⁢ s θ - s φ ⁢ c θ ⁢ s θ s φ ⁢ c θ ⁢ s θ s θ 2 c θ 2 ) ⁢ ( ℏ xx ℏ zz ) , ( 25 ) where θ is the relative inclination of the borehole axis to the normal to the bedding while φ is the azimuth. These angles are in the tool coordinate system. As noted above, Zhang et al. provides a description of the different coordinate systems, s φ =sin φ, c φ =cos φ s θ =sin θ, c θ =cos θ. Eq. (25) enables a calculation of the principal MFF components of Eq. (24). A typical method of solving Eq. (25) employs a least squares method. The obtained principal MFFM components xx and zz enable a sequential process for obtaining conductivity parameters. First, the horizontal conductivities can be determined from the zz component using the standard inversion methods of prior art, and then the vertical conductivity can be determined from the xx component and the horizontal conductivity, again using the standard inversion methods of prior art. [0073] FIG. 12 shows a flowchart of an exemplary embodiment of a first embodiment of the present invention. MFFM is applied using the 3DEX™ measurement tool (Box 1401 ). The obtained measurements are the components of the matrix of the left hand side of Eq. (23). If the angles θ and φ are known, separation of modes is then performed (Box 1403 ). Fundamental modes are typically the principal components xx and zz of the diagonalized multifrequency matrix. One way to separate the modes is by performing a least squares operation, for example, on Eq. (25). Acquisition of at least 2 or more independent components enable a solution of Eq. (25), having 2 unknown on its right-hand side. Thus, a requirement is that the number n 1 of focused measurements must be at least, or must be capable of giving two independent measurements. In Box 1405 , knowledge of zz relative dip θ, and relative azimuth φ enables determination of the horizontal conductivity, σ h using the standard prior art inversion methods, such as that described in U.S. Pat. No. 6,636,045 to Tabarovsky et al. (Tabarovsky '045) incorporated herein by reference. Vertical conductivity σ v is then determined (Box 1407 ) using σ h , relative dip θ and relative azimuth φ, again using the standard prior art methods such as that in Tabarovsky '045. Calculations can be made either uphole or downhole. Downhole computation might comprise use of a processor or expert system. [0074] FIG. 13 details an exemplary method of a second embodiment of the invention for recovering formation dip and formation azimuth given the obtained MFFM components. Formation angles are determined simultaneously with the principal components. This is different from the method disclosed in Tabarovsky '045 where an iterative process is used for determination of formation angles. In Box 1501 , the entire processing interval is subdivided into relatively small windows in which values of the relative formation dip and relative formation azimuth within the windows are substantially constant. The term “relative” refers to the formation dip and azimuth in a wellbore based coordinate system. We denote these angles by Θ and Φ. As shown in Box 1503 , a number of incremental values of relative formation dip are selected from a range, such as from zero to ninety degrees at every logging depth. At every given logging depth and formation dip, the relative formation azimuth is changed incrementally from 0 to 360 degrees. This change of relative formation azimuth is shown in Box 1505 . In Box 1507 , relative dip θ and relative azimuth φ 0 in the tool coordinate system are calculated using the tool orientation angle. The relative dip θ in the tool coordinate system will be the same as the trial value of Θ. The tool orientation angle necessary for this calculation is obtained using suitable orientation sensors. For example, magnetometers may be used. In Box 1509 , the system of Eq. (13) for unknown xx and zz can be solved for every pair of relative dip θ and relative azimuth φ in the tool coordinate system (and corresponding values of Θ and Φ in the borehole coordinate system). In Box 1511 , the four obtained values of θ, φ, xx and zz can be substituted in Eq. (25), and calculations can be made of a misfit value. Typically, a misfit value can be calculated using a norm of the measured MFF components and of the values of {tilde over (h)} components according to eq. (25). In Box 1513 , for every pair of relative dip θ and relative azimuth φ (or alternately, for the formation dip and azimuth) the misfits can be summed at all logging depths in the window and a minimum value can be selected. The minimum value corresponds to a specific combination of Θ and Φ. With the known θ and φ (or the formation dip and azimuth) xx and zz is calculated at every depth. The results of xx and zz are used in the sequential interpretation for σ h and σ v , 1515 described in U.S. Pat. No. 6,574,562 to Tabarovsky et al. (Tabarovsky '562) incorporated herein by reference. An advantage of the present invention over Tabarovsky '045 is the ability to obtain angles simultaneously without using a time-consuming iterative procedure. In addition, unlike the method of Tabarovsky '045, an initial estimate of formation dip and formation azimuth relative to borehole axis is not necessary. At 1517 , the absolute formation dip and azimuth in an earth coordinate system may be obtained using known values of borehole inclination and azimuth. Data regarding the borehole inclination and azimuth may be obtained from suitable survey sensors such as accelerometers and or gyroscopes. [0075] The example given above was based on searching through a range of possible values of formation dip and azimuth in a borehole coordinate system. The method is equally applicable searching through a range of possible values of formation dip and azimuth in a fixed earth based coordinate system. The search could also be done in a tool-based coordinate system. Alternatively, any combination of coordinate systems may be used. The point to note is that angles are obtained simultaneously with resistivity parameters. [0076] To illustrate the validity of the diagonalization procedure, a numerical example is presented. The specific example is a wireline example, but the method is equally applicable to MWD measurements. Single frequency and multi-frequency responses are calculated in a thick anisotropic layer with σ h =1 S/m, σ v =0.25 S/m. The angles of relative dip and relative rotation are, respectively, θ=60°, φ=30°. The principal components of the single frequency magnetic matrix (skin-effect corrected and normalized to apparent conductivity, in S/m) become H ^ = ( 0.496 0 0.99 0 0.678 0 0.99 0 1.03 ) , ( 26 ) It is noted that in eq. (26), the terms h xx and h yy are not equal. In addition, h xz and h zx have significant non zero values. [0077] In contrast, MFFM principal components normalized to apparent conductivity become H ^ MFF = ( 0.572 0 0.019 0 0.580 0 0.019 0 0.973 ) . ( 27 ) Numerical results, eq. (27), agree with the theoretical results within numerical accuracy of calculation of the MFF and skin-effect corrected components. [0078] Another example illustrates the ability of the present invention to enable angle determination. To demonstrate use of the present invention for determining angles, as described above, the measurements of the 3DEX™ tool in a thick anisotropic layer are simulated with σ h =1 S/m and σ v =0.25 S/m for three different combinations of relative dip and relative rotation angles. The MFF transformation is applied to all five obtained magnetic field components and then the algorithm of FIG. 13 is executed. Table 1 presents the original relative dip and rotation angles and results of the processing. TABLE 1 Model parameters Recovered parameters # θ (deg) φ (deg) h xx (S/m) h zz (S/m) θ (deg) φ (deg) h xx (S/m) h zz (S/m) 1 40 30 0.576 0.973 39 30 0.570 0.971 2 54.73 45 0.576 0.973 53 44 0.576 0.965 3 70 80 0.576 0.973 70 80 0.578 0.960 The processing results agree very well with the original angles. [0079] In one embodiment of the invention, reservoir navigation may be done by maintaining a fixed angle between the tool and the anisotropy axis. When the anisotropy is normal to the bedding plane, the fixed angle is 90°. If the angle is known to be different from 90° (for example, due to cross-bedding), then this value may be used for reservoir navigation. A particular situation in which navigation based on maintaining a fixed relative angle is useful is in drilling through a thick, homogenous shale formation. Such formations have electrical anisotropy but relatively few resistivity contrasts that can be used for navigation using prior art methods. Gyroscopic surveys are time consuming and expensive. The method of the present invention is able to give estimates in real time between the borehole axis and the anisotropy axis. [0080] The principal components determined above may then also be used as a distance indicator to the interface. This has been discussed in Merchant et al. The cross-component xz signal gives the direction to the interface. As noted above, different frequency selections/expansion terms have their maximum sensitivity at different distances. Accordingly, in one embodiment of the invention, the frequency selection and the number of expansion terms is based on the desired distance from an interface in reservoir navigation. It should be noted that for purposes of reservoir navigation, it may not be necessary to determine an absolute value of formation resistivity: changes in the focused signal using the method described above are indicative of changes in the distance to the interface. The direction of drilling may be controlled by a second processor or may be controlled by the same processor that processes the signals. The computations for MFFM and the principal component separation may be done in real time, making the use of resistivity measurements suitable for reservoir navigation. [0081] The processing of the data may be accomplished by a downhole processor. Implicit in the control and processing of the data is the use of a computer program implemented on a suitable machine readable medium that enables the processor to perform the control and processing. The machine readable medium may include ROMs, EPROMs, EAROMs, Flash Memories and Optical disks. [0082] While the foregoing disclosure is directed to the preferred embodiments of the invention, various modifications will be apparent to those skilled in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure. [0000] Appendix: Taylor's Frequency Series for MWD Electromagnetic Tool [0083] We intend to evaluate the asymptotic behavior of magnetic field on the surface of a metal mandrel as described in Eq. (6): H α ⁡ ( P ) = H α 0 ⁡ ( P ) + β ⁢ ∫ S ⁢ {   H → ⁢   ⁢   M ⁢   ⁢ α ⁢ h → } ⁢ ⅆ S ( A1 ⁢ .1 ) The primary and auxiliary magnetic fields, H α 0 and Mα {right arrow over (h)}, depend only on formation parameters. The total magnetic filed, H α , depends on both formation parameters and mandrel conductivity. The dependence on mandrel conductivity, σ c , is reflected only in parameter β: β = 1 k c = 1 - ⅈωμσ c ( A1 ⁢ .2 ) The perturbation method applied to Eq. (A1.1) leads to the following result: H α = ∑ i = 0 i = ∞ ⁢ H α ( i ) ( A1 ⁢ .3 ) H α ( 0 ) = H α 0 ( A1 ⁢ .4 ) H α ( 0 ) = β ⁢ ∫ S ⁢ {   ( i - 1 ) ⁢ H → ⁢   M ⁢   ⁢ α ⁢ h → } ⁢   ⁢ ⅆ S ⁢ ⁢ i = 1 , … ⁢   , ∞ ( A1 ⁢ .5 ) [0084] Let us consider the first order approximation that is proportional to the parameter β: H α ( 1 ) = β ⁢ ∫ S ⁢ {   ( 0 ) ⁢ H → ⁢   M ⁢   ⁢ α ⁢ h → } ⁢   ⁢ ⅆ S = β ⁢ ∫ S ⁢ {   H → 0 ⁢   ⁢   M ⁢   ⁢ α ⁢ h → } ⁢ ⅆ S ( A1 ⁢ .6 ) The integrand in Eq. (A1.6) does not depend on mandrel conductivity. Therefore, the integral in right-hand side, Eq. (A1.6), may be expanded in wireline-like Taylor series with respect to the frequency: ∫ S ⁢ {   H → 0 ⁢   ⁢   M ⁢   ⁢ α ⁢ h → } ⁢ ⅆ S ≈ b 0 + ( - ⅈωμ ) ⁢ b 1 + ( - ⅈωμ ) 3 / 2 ⁢ b 3 / 2 + ( - ⅈωμ ) 2 ⁢ b 2 + … ( A1 ⁢ .7 ) In axially symmetric models, coefficients b j have the following properties: b 0 does not depend on formation parameters. It is related to so called ‘direct field’; b 1 is linear with respect to formation conductivity. It is related to Doll's approximation; b 3/2 depends only on background conductivity and does not depend on near borehole parameters; b 2 includes dependence on borehole and invasion. [0089] Let us substitute Eq. (A1.7) into Eq. (A1.6): H α ( 1 ) = 1 σ c ⁢ ( b 0 ( - ⅈωμ ) 1 / 2 + ( ⅈωμ ) 1 / 2 ⁢ b 1 + ( - ⅈωμ ) ⁢ b 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b 2 + … ) ( A1 ⁢ .8 ) Eq. (A3.3), (A3.4), and (A3.8) yield:   H α ≈ H α 0 + 1 σ c ⁢ ( b 0 ( - ⅈωμ ) 1 / 2 + ( ⅈωμ ) 1 / 2 ⁢ b 1 + ( - ⅈωμ ) ⁢ b 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b 2 + … ) ( A1 ⁢ .9 ) Collecting traditionally measured in MFF terms ˜ω 3/2 , we obtain: ( - ⅈωμ ) 3 / 2 ⁢ ( H α ) 3 / 2 ≈ ( - ⅈωμ ) 3 / 2 ⁢ ( H α 0 ) 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b 2 σ c ( A1 ⁢ .10 ) The first term in the right hand side, Eq. (A1.10), depends only on background formation. The presence of imperfectly conducting mandrel makes the MFF measurement dependent also on a near borehole zone parameters (second term, coefficient b 2 ) and mandrel conductivity, σ c . This dependence, obviously, disappears for a perfect conductor (σ c →∞). We should expect a small contribution from the second term since conductivity σ c is very large. [0090] To measure the term ˜ω 3/2 , we can modify MFF transformation in such a way that contributions proportional to 1/(−iωμ) 1/2 and (−iωμ) 1/2 , Eq. (A1.9), are cancelled. We also can achieve the goal by compensating the term ˜1/(−iωμ) 1/2 in the air and applying MFF to the residual signal. The latter approach id preferable because it improves the MFF stability (less number of terms needs to be compensated). Let us consider a combination of compensation in the air and MFF in more detail. It follows from Eq. (A1.9) that the response in the air, H α (σ=0), may be expressed in the following form: H α ⁡ ( σ = 0 ) ≈ H α 0 ⁡ ( σ = 0 ) + 1 σ c ⁢ ( b 0 ( - ⅈωμ ) 1 / 2 ) ( A1 ⁢ .11 ) Compensation of the term ˜b 0 , Eq. (A1.11), is important. Physically, this term is due to strong currents on the conductor surface and its contribution (not relating to formation parameters) may be very significant. Equations (A1.9) and (A1.11) yield the following compensation scheme: H α - H α ⁡ ( σ = 0 ) ≈ ( - ⅈωμ ) ⁢ ( H α ) 1 + ( - ⅈωμ ) 3 / 2 ⁢ ( H α ) 3 / 2 + 1 σ c ⁢ ( ( - ⅈωμ ) 1 / 2 ⁢ b 1 + ( - ⅈωμ ) ⁢ b 3 / 2 + ( - ⅈωμ ) 3 / 2 ⁢ b 2 + … ) ( A1 ⁢ .12 ) Considering measurement of imaginary component of the magnetic field, we obtain: Im ⁡ [ H α - H α ⁡ ( σ = 0 ) ] ≈ - { 1 σ c ⁢ ( ωμ 2 ) 1 / 2 ⁢ b 1 + ωμ ⁢   ⁢ ( H α ) 1 + ( ωμ 2 ) 3 / 2 ⁢ ( ( H α ) 3 / 2 + b 2 σ c ) } ( A1 ⁢ .13 ) Equation (A1.13) indicates that in MWD applications, two frequency terms must be cancelled as opposed to only one term in wireline. Equation, (A1.4), modified for MWD applications has the following form: ( H ⁡ ( ω 1 ) H ⁡ ( ω 2 ) . . . H ⁡ ( ω m - 1 ) H ⁡ ( ω m ) ) = ( ω 1 1 / 2 ω 1 1 ω 1 3 / 2 ω 1 5 / 2 • • • ω 1 n / 2 ω 2 1 / 2 ω 2 1 ω 2 3 / 2 ω 2 5 / 2 • • • ω 2 n / 2 • • • • • • • • • • • • • • • • • • • • • • • • ω m - 1 1 / 2 ω m - 1 1 ω m - 1 3 / 2 ω m - 1 5 / 2 • • • ω m - 1 n / 2 ω m 1 / 2 ω m 1 ω m 3 / 2 ω m 5 / 2 • • • ω m n / 2 ) ⁢ ( s 1 / 2 s 1 s 3 / 2 s 5 / 2 • • • S n / 2 ) ( A1 ⁢ .14 ) The residual signal (third term) depends on the mandrel conductivity but the examples considered in the report illustrate that this dependence is negligible due to very large conductivity of the mandrel. Similar approaches may be considered for the voltage measurements.

A multicomponent induction logging tool is used on a MWD bottomhole assembly. Multifrequency focusing that accounts for the finite, nonzero, conductivity of the mandrel is applied. Using separation of modes, the principal components and relative dip angles in an earth formation are determined. The results are used for reservoir navigation in an earth formation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a portable terminal apparatus with a telephone function, such as a portable telephone. [0003] 2. Description of the Related Art [0004] In recent years, portable terminal apparatus such as portable telephones are remarkably developing, and it is demanded that they become further multifunctional, miniaturized and lightweight. [0005] The portable telephone in recent years has a speaker built therein to hear a voice without putting one's ear on the portable telephone, and the speaker now has high performance and high sound quality to output music of the high sound quality. Japanese Patent Laid-Open No. 2002-345084 discloses an example of the speaker built into the portable telephone. The speaker disclosed in Japanese Patent Laid-Open No. 2002-345084 has a front face rim of its sound producing section surrounded by a circular gasket and a connector mounted on its backside, where assembly man-hours are reduced. [0006] As a part of multifunctionality of a portable terminal apparatus such as a portable telephone, it is considered to provide openings for emitting a voice from a speaker on both the front face and backside of a housing of the portable telephone so that the voice from the speaker can be heard whether a folding type portable telephone is open or closed for instance. [0007] Here, the speaker disclosed in Japanese Patent Laid-Open No. 2002-345084 is intended to emit the voice only to the front face side, and has a connector mounted on its backside so that its structure is not suited to emitting a voice from the backside. [0008] To emit the voice from both the front face and backside, the speaker of an ordinary type having a lead connected thereto is adopted rather than the speaker of a special structure as disclosed in Japanese Patent Laid-Open No. 2002-345084, and the backside of the speaker is also used. As the speaker is constituted to produce a sound from the front face, the sound from the backside has a low sound pressure. Therefore, it is necessary to devise a method to emit the voice efficiently so that it can be heard at a sufficient volume from the backside. Here, the sound from the front face of the speaker and the sound from the backside of the speaker are mutually in opposite phases, and so they are mutually canceled to reduce the sound pressure consequently if a part of the sound from the front face of the speaker is emitted from the housing in concert with the sound from the backside of the speaker. SUMMARY OF THE INVENTION [0009] The present invention has been made in view of the above circumstances and provides a portable terminal apparatus having a structure capable of efficiently emitting the voice from the speaker from both the front face and backside of the housing. [0010] The portable terminal apparatus according to the present invention is a portable terminal apparatus with a telephone function, including: [0011] a speaker having a sound producing section and a connecting section to which a lead to convey a sound signal to the sound producing section is connected; [0012] a plate-like assembly having a speaker accommodating section which has a front face of the speaker exposed and also has an opening formed and placed on a backside of the speaker with a space and connecting the space to outside; [0013] a first cover having a first sound producing section which emits a voice from the speaker to the outside at a position opposed to the front face of the speaker and covering a face on a side of the assembly facing the front face of the speaker; [0014] a second cover having a second sound producing section which emits the voice from the speaker to the outside at a position opposed to the opening and covering the face on the side of the assembly facing the backside of the speaker; and [0015] a gasket accommodated at a position sandwiched between the assembly and the first cover, surrounding a rim of the sound producing section of the speaker and covering the connecting section so as to prevent propagation of the voice between the space and the first sound producing section. [0016] In the case of the structure for emitting the voice only to the front face of the speaker by adopting the ordinary type speaker having the lead connected thereto, a circular gasket surrounding the sound producing section of the speaker is placed so as not to have vibration of the speaker conveyed to parts around the speaker and housing parts and resonate to generate noise as in the case of Japanese Patent Laid-Open No. 2002-345084 for instance. The structure in which the sound producing section of the speaker does not directly contact the surrounding parts is thus adopted. If the opening for emitting the voice to the backside of the speaker of the housing is formed with the as-is structure, however, the voice of sufficient sound pressure cannot be obtained from the backside of the speaker of the housing. [0017] According to the present invention, the connecting section of the speaker having the lead connected thereto which is no problem in the case of the structure for emitting the sound only from the front face of the speaker is also clogged up with the gasket. Thus, it prevents the voice on the front face of the speaker from going through the opening of the connecting section and running round to the backside of the speaker to mutually cancel the voice with that from the backside of the speaker and also prevents the sound on the backside from leaking into the housing. According to the present invention, it is possible, by clogging up the connecting section with the gasket, to efficiently emit the voice from the backside of the speaker from the second sound producing section as the voice of sufficient sound pressure. [0018] Here, as for the portable terminal apparatus according to the present invention, it should desirably have the gasket accommodated at the position sandwiched between the assembly and the second cover and surrounding the rim of the opening so as to prevent a leak of the voice from the opening to a section other than the second sound producing section. [0019] It is thus possible to prevent the voice on the backside of the speaker from leaking to a section other than the second sound producing section so as to emit the voice more efficiently from the second sound producing section. [0020] The portable terminal apparatus according to the present invention may have a pair of housings mutually supported on an axis to be pivotable and mutually openable and closable, wherein one of the housings includes the speaker, the assembly, the first cover, the second cover and the gasket. [0021] The present invention is suitable for such a folding type portable terminal apparatus. [0022] As for the portable terminal apparatus according to the present invention, it is desirable that the first sound producing section have an opening formed on the first cover and a covering which covers the opening and passes the voice and the second sound producing section have an opening formed on the second cover and a covering which covers the opening and passes the voice. [0023] It is possible, by placing such coverings, to emit the voice to the outside, prevent outside dust from coming in and also prevent an internal structure from being peeped at from the outside. [0024] As described above, according to the present invention, it is possible to emit the sound from the speaker with the sufficient sound pressure from both the front face and backside of the housing. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 is a perspective view showing an appearance of a portable telephone as an embodiment of a portable terminal apparatus according to the present invention; [0026] FIG. 2 is a perspective view showing the appearance of the portable telephone as an embodiment of the portable terminal apparatus according to the present invention; [0027] FIG. 3 is a perspective view showing the appearance of the portable telephone as an embodiment of the portable terminal apparatus according to the present invention; [0028] FIG. 4 is a perspective view showing the appearance of the portable telephone as an embodiment of the portable terminal apparatus according to the present invention; [0029] FIG. 5 is an exploded perspective view of an upside housing of the portable telephone shown in FIGS. 1 to 4 ; [0030] FIG. 6 is an exploded perspective view of the upside housing of the portable telephone shown in FIGS. 1 to 4 ; [0031] FIG. 7 is a perspective view showing an out-camera and an out-camera holder; [0032] FIG. 8 is a perspective view showing a camera assembly consisting of an out-camera and an out-camera holder and a circuit board; [0033] FIG. 9 is a plan view showing the camera assembly placed on the circuit board; [0034] FIG. 10 is a sectional view along an arrow B to B shown in FIG. 9 ; [0035] FIG. 11 is a diagram showing the circuit board having the camera assembly mounted thereon and a chassis on which the circuit board is to be fixed; [0036] FIG. 12 is a perspective view of the assembly having the circuit board mounted on the chassis; [0037] FIG. 13 is a plan view showing the face of the assembly shown in FIGS. 5 and 6 facing an inside cover side; [0038] FIG. 14 is an enlarged plan view of the inside of a circle A shown in FIG. 3 ; [0039] FIG. 15 is an exploded perspective view of the downside housing of the portable telephone shown in FIGS. 1 to 4 ; [0040] FIG. 16 is an exploded perspective view of the downside housing of the portable telephone shown in FIGS. 1 to 4 ; [0041] FIG. 17 is a plan view showing the inner face of an outside cover constituting the downside housing; [0042] FIG. 18 is a plan view showing the downside housing; [0043] FIG. 19 is a sectional view along the arrow A to A shown in FIG. 18 ; [0044] FIG. 20 is a sectional view along the arrow B to B shown in FIG. 18 ; [0045] FIG. 21 is a further exploded view showing the inside cover constituting the downside housing; [0046] FIG. 22 is a diagram showing the inside cover in a state of placing a push button sheet on a frame; [0047] FIG. 23 is a plan view showing the downside housing; [0048] FIG. 24 is a sectional view along the arrow A to A shown in FIG. 23 ; [0049] FIG. 25 is a partially enlarged view enlarging and showing the inside of a circle R 1 shown in FIG. 24 ; [0050] FIG. 26 is a sectional view along the arrow B to B shown in FIG. 23 ; and [0051] FIG. 27 is a partially enlarged view enlarging and showing the inside of a circle R 2 shown in FIG. 26 . DETAILED DESCRIPTION OF THE INVENTION [0052] Hereafter, an embodiment of the present invention will be described. [0053] FIGS. 1 to 4 are perspective views showing an appearance of a portable telephone which is an embodiment of the present invention. [0054] The portable telephone shown here is a folding type. FIG. 1 is a perspective view showing an inside in an open state, FIG. 2 is a perspective view showing an outside in the open state, FIG. 3 is a perspective view showing an upside housing in a closed state, and FIG. 4 is a perspective view showing a downside housing in the closed state. [0055] A portable telephone 10 is consisting of an upside housing 100 and a downside housing 200 mutually supported on an axis to be pivotable. [0056] As shown in FIG. 1 , on an inner face of the upside housing 100 , there is a large display window 101 for viewing a liquid crystal display screen placed therein extended in the middle. The display window 101 has three push buttons 102 arranged on its downside. On the upside of the display window 101 , there are also an ear piece 103 for putting one's ear thereto to catch voice and a shooting window 104 for a digital camera facing the inside (the digital camera is called an “in-camera” here because it faces the inside) to look in provided beside it. [0057] As shown in FIGS. 2 and 3 , the upside housing 100 has a display window 105 for viewing another liquid crystal display screen placed therein provided in the middle of an outer face thereof. On a hinge side linked to the downside housing 200 further from the display window 105 , there are provided a shooting window 106 for another digital camera (the digital camera is called an “out-camera” here because it faces the outside) to look in and a lighting section 107 for lighting up by having an LED inside it emit light to give notice of an incoming call and so on. [0058] On an inner side face of the downside housing 200 , there are a number of arranged push buttons 201 and a mouthpiece 202 having a microphone for receiving a user's voice and converting it to an electrical signal provided therein on the downside of the push buttons 201 as shown in FIG. 1 . Furthermore, a sound outlet 203 for emitting the voice from a speaker provided inside is provided in the proximity of the hinge section of the downside housing 200 linked to the upside housing 100 . As will be described later, the speaker provided at a depth of the sound outlet 203 faces the outside of the downside housing 200 . Therefore, the sound outlet 203 is placed on a backside of the speaker. [0059] As shown in FIGS. 2 and 4 , the downside housing 200 has another sound outlet 204 for emitting the voice from the speaker front and a battery accommodating section 205 having a battery accommodated therein provided on the outer face thereof. [0060] FIGS. 5 and 6 are exploded perspective views of the upside housing of the portable telephone shown in FIGS. 1 to 4 . [0061] The upside housing 100 is consisting of an inside cover 110 , an assembly 120 and an outside cover 130 , and has a structure for sandwiching the assembly 120 having a number of parts built therein between the inside cover 110 and outside cover 130 . [0062] As shown in FIG. 5 , the assembly 120 has a liquid crystal display screen 121 provided at a position inside the display window 101 of the inside cover 110 . And it has a receiver 123 for receiving a sound signal and producing a sound provided at a position equivalent to the inside of the ear piece 103 of the inside cover 110 , and also has an in-camera 124 provided at a position equivalent to the inside of the shooting window 104 of the inside cover 110 . Furthermore, the assembly 120 has contacts 122 for being turned on and off by pushing the push buttons 102 , which are provided at positions equivalent to the insides of the three push buttons 102 provided on the inside cover 110 . [0063] As shown in FIG. 6 , the assembly 120 also has a liquid crystal display screen 125 , an out-camera 126 and an LED 127 that are provided at positions equivalent to the insides of the display window 105 , shooting window 106 and lighting section 107 of the outside cover 130 respectively. [0064] The assembly 120 has a number of electronic circuit modules and so on other than the parts provided therein. [0065] Next, the structure of the assembly 120 constituting the upside housing 100 will be described by centering on a mounting structure of the out-camera 126 . [0066] FIG. 7 is a perspective view showing the out-camera and an out-camera holder. Here, Part (A) of FIG. 7 is a perspective view separately showing the out-camera and out-camera holder, and Part (B) of FIG. 7 is a perspective view showing a state of accommodating the out-camera in the out-camera holder. [0067] The out-camera 126 has a lens and an image pickup device that is not shown built therein. The out-camera 126 is connected to a flexible board 141 having wiring for conveying an image signal obtained by that image pickup device, and the flexible board 141 further has a connector 142 mounted thereon. The out-camera 126 faces downward in FIG. 7 . [0068] An out-camera holder 150 has an opening 151 for the out-camera 126 to look in provided in the middle thereof, and a wall section 152 is mounted surrounding the opening 151 . As shown in Part (B) of FIG. 7 , the out-camera 126 is accommodated in a portion surrounded by the wall section 152 , and the wall section 152 supports the out-camera 126 by surrounding it. The out-camera holder 150 has two arm sections 153 extended on both sides, and mounting holes 154 are provided at ends of the two arm sections 153 . [0069] FIG. 8 is a perspective view showing a camera assembly consisting of the out-camera and out-camera holder and a circuit board. Part (A) of FIG. 8 is a perspective view separately showing the camera assembly consisting of the out-camera and out-camera holder and the circuit board. Part (B) of FIG. 8 is a perspective view showing a state of mounting the camera assembly on the circuit board. [0070] A circuit board 160 has an opening 161 for placing the out-camera, mounting holes 162 , 163 and 164 and a positioning hole 165 provided thereon. [0071] Instead of the opening 161 , the circuit board 160 may have a notch formed by extending the opening 161 to one side of the circuit board 160 . However, a description will be continued here by assuming that the circuit board 160 has the opening 161 formed thereon. [0072] Here, the mounting hole 162 is provided at a position to overlap the mounting hole 154 of the out-camera holder 150 when a camera assembly 140 is placed to have the out-camera 126 look out of the opening 161 . [0073] When placing the camera assembly 140 on the circuit board 160 , the flexible board 141 goes down through the opening 161 and is placed through the backside of the circuit board 160 as shown by an arrow x in Part (A) of FIG. 8 . [0074] FIG. 9 is a plan view showing the camera assembly placed on the circuit board. FIG. 10 is a sectional view along an arrow B-B shown in FIG. 9 . [0075] FIG. 10 shows how the flexible board 141 extended from the out-camera 126 goes down through the opening 161 of the circuit board 160 and runs through the backside of the circuit board 160 . [0076] FIG. 11 is a diagram showing the circuit board having the camera assembly mounted thereon and the chassis on which the circuit board is to be fixed. Part (A) of FIG. 11 is a diagram separately showing the circuit board and chassis. Part (B) of FIG. 11 is a diagram showing the assembly having the circuit board mounted on the chassis. [0077] FIG. 12 is a perspective view of the assembly having the circuit board mounted on the chassis. [0078] A chassis 170 is made by die-casting a magnesium alloy. The chassis 170 has walls 171 standing thereon and also has screw holes 172 , mounting holes 173 , a screw hole 181 and a positioning projection 182 provided thereon. The chassis 170 also has a long and thin slit 174 penetrating a front face and a rear face provided thereon. [0079] As shown in FIG. 5 , the chassis 170 has three contacts 122 provided on a rear face to the face shown in Part (A) of FIG. 11 , and a flexible board 175 connected to the three contacts 122 goes through the slit 174 and is extended to the face of the chassis 170 shown in FIG. 11 . The flexible board 175 is also extended to the circuit board 160 side without going through the slit 174 . [0080] Furthermore, the chassis 170 has a receiver fixing section 176 for fixing the receiver 123 (refer to FIG. 5 ), an in-camera placement section 177 for placing the in-camera 124 (refer to FIG. 5 ), and a canopy section 178 projecting from a body section of the chassis 170 described later provided thereon. [0081] As shown by the arrow in Part (A) of FIG. 11 , the circuit board 160 has the face on the side shown in Part (A) of FIG. 11 placed on the chassis 170 in a direction to contact the face on the side shown in Part (A) of FIG. 11 . The two screw holes 172 provided on the chassis 170 are provided on positions overlapping the two mounting holes 162 provided on the circuit board 160 and the two mounting holes 154 provided on the out-camera holder 150 . The mounting holes 173 , screw hole 181 and positioning projection 182 provided on the chassis 170 are corresponding to the mounting holes 163 , 164 and positioning hole 165 provided on the circuit board 160 respectively. If the circuit board is placed on the chassis 170 , the positioning projection 182 of the chassis 170 gets into the positioning hole 165 of the circuit board 160 so that the circuit board 160 is screwed on the chassis 170 with screws 183 and 184 shown in Part (B) of FIG. 11 . In this case, the out-camera holder 150 and the circuit board 160 are screwed together on the chassis 170 . The out-camera 126 set in the out-camera holder 150 has its backside supported by the chassis 170 via the flexible board 175 . Thus, the out-camera 126 is supported by the out-camera holder 150 and also directly supported by the chassis 170 so as to be fixed as securely as directly fixing the out-camera 126 on the chassis 170 . Here, it is also feasible to render size of the mounting holes 154 of the out-camera holder 150 a little larger so as to fine-tune a mounting position and a posture (angle) of the out-camera 126 . [0082] After the circuit board 160 is placed on the chassis 170 , the mounting holes 163 other than the mounting holes 162 and 164 of the circuit board 160 screwed on the chassis 170 and the mounting holes 173 out of the mounting holes 173 and 179 on the chassis 170 are screwed at a screw hole 109 (refer to FIG. 6 ) on the inside cover 110 . And the mounting hole 179 on the chassis 170 is screwed at a screw hole 139 on the outside cover 130 with a screw inserted from a mounting hole 108 (refer to FIG. 5 ) on the inside cover 110 . [0083] FIGS. 11 and 12 do not show the receiver 123 and in-camera 124 (refer to FIG. 5 ). However, the receiver 123 is fixed on the receiver fixing section 176 of the chassis 170 , and the in-camera 124 is placed on the in-camera placement section 177 of the chassis 170 . The in-camera placement section 177 has an opening 177 a for the in-camera to look in provided in the middle, and also has a wall 177 b formed in surroundings thereof. And the in-camera 124 is placed in the in-camera placement section 177 of the chassis 170 so as to be directly and strongly held by the chassis 170 . [0084] Though it is not shown in FIGS. 11 and 12 , the liquid crystal display screen (refer to FIG. 6 ) facing the outside cover 130 from the top of the circuit board 160 placed on the chassis 170 is placed in an area surrounded by the walls 171 of the chassis 170 . [0085] Thus, the circuit board 160 is placed on the chassis 170 and necessary parts are further mounted to constitute the assembly 120 shown in FIGS. 5 and 6 . [0086] The assembly 120 is assembled in a state of being sandwiched between the inside cover 110 and the outside cover 130 as previously described so as to constitute the upside housing 100 of the portable telephone. [0087] FIG. 13 is a plan view showing the face of the assembly 120 shown in FIGS. 5 and 6 facing the inside cover 110 side. FIG. 14 is an enlarged plan view of the inside of a circle A shown in FIG. 13 . [0088] FIG. 13 shows the liquid crystal display screen 121 , three contacts 122 , receiver 123 , in-camera 124 and so on fixed on the chassis 170 . [0089] A lead 189 for conveying the sound signal to the receiver 123 is extended from the receiver 123 , and a connector 188 is connected to the end of the lead 189 . The connector 188 is connected to a connector 169 on the circuit board 160 . Here, the lead 189 is reasonably long to facilitate assembly work for fitting the connector 188 at its end to the connector 169 on the circuit board 160 . If the assembly work thereafter is performed with the lead 189 remaining as-is on the liquid crystal display screen 121 , the assembly becomes incomplete. Thus, the projecting canopy section 178 for regulating a wiring position of the lead 189 is provided on the chassis 170 for fixing the receiver 123 so as to hold down the lead 189 with the canopy section 178 . It is possible, by providing such a canopy section 178 , to wire the lead 189 at a proper position not interfering with the assembly. [0090] Next, a description will be given as to the structure of the downside housing 200 (refer to FIGS. 1 and 2 ) of the portable telephone 10 described here. [0091] FIGS. 15 and 16 are exploded perspective views of the downside housing of the portable telephone shown in FIGS. 1 to 4 . [0092] As with the upside housing 100 (refer to FIGS. 5 and 6 ) described so far, the downside housing 200 is also consisting of an inside cover 210 , an assembly 220 and an outside cover 230 , and has a structure for sandwiching the assembly 220 having a number of parts built therein with the inside cover 210 and outside cover 230 . [0093] The assembly 220 is plate-like as a whole, and contacts 221 to be turned on by pushing the push buttons are placed at positions corresponding to multiple push buttons 201 provided on the inside cover 210 respectively. And multiple LEDs 222 for lighting up the push buttons 201 are dispersedly placed. One LED 222 a of the multiple LEDs 222 lights up a call button 201 a out of the multiple push buttons 201 , which is equivalent to picking up a receiver of a conventional telephone. Another LED 222 b lights up a call button 201 b out of the multiple push buttons 201 . The multiple LEDs 222 which are dispersedly placed emit light all together and thereby light up the multiple push buttons 201 all together. [0094] According to this embodiment, placement of the LEDs 222 is determined so that, on lighting up the multiple push buttons 201 all together, the multiple push buttons 201 including the call buttons 201 a and 201 b will light up all together without having the LEDs 222 a and 222 b for lighting up only the call buttons 201 a and 201 b emit light. And according to this embodiment, the LEDs 222 except the LEDs 222 a and 222 b emit light on lighting up the multiple push buttons 201 all together. However, it is also feasible, as the placement of the LEDs, to have the call buttons 201 a and 201 b lighted up by the LEDs 222 a and 222 b on lighting up the multiple push buttons 201 all together so as to have the LEDs 222 including the LEDs 222 a and 222 b emit light on lighting up the multiple push buttons 201 all together. [0095] Here, the call button 201 a as one of the two call buttons 201 a and 201 b is the push button to be pushed when making an ordinary call only with voice. The other call button 201 b is the push button to be pushed when making a video-phone call accompanied by image communication. In FIG. 15 , a light shielding member 223 is provided as if surrounding the portion corresponding to the call button 201 b for video-phone of the assembly 220 . This is intended to light up the call button 201 b when the LED 222 b emits light and prevent the other push buttons from lighting up due to the light leaked from the LED 222 b . Details will be described later. [0096] The assembly 220 has an opening 225 formed thereon for the sake of emitting the voice from the backside of the speaker (refer to FIG. 16 ) from the assembly 220 . The voice emitted from the opening 225 is outputted to the outside of the portable telephone from the sound outlet 203 provided on the inside cover 210 . [0097] The outside cover 230 shown in FIG. 15 has an opening 233 for accommodating the battery formed thereon, and a mesh 231 is adhered to the inside of the sound outlet 204 (refer to FIGS. 2, 4 and 16 ) for emitting the voice from the front of the speaker (refer to FIG. 16 ) to the outside of the housing. The mesh 231 plays a role of emitting the voice from the speaker to the outside from the sound outlet 204 and preventing dust of the outside from entering into the housing. [0098] A gasket 232 is adhered as if surrounding the sound outlet 204 (refer to FIGS. 2, 4 and 16 ) having the mesh 231 adhered thereto. The gasket 232 is intended to prevent a sound leak from around the speaker. Details of the gasket 232 will also be described later. [0099] As shown in FIG. 16 , on the inner face of the inside cover 210 , there are a mesh 211 adhered to the inside of the sound outlet 203 (refer to FIGS. 1 and 15 ) and a gasket 212 adhered thereto by surrounding the mesh 211 provided. The gasket 212 clogs up the surroundings of the opening 225 of the assembly 220 shown in FIG. 15 to prevent the voice emitted from the opening 225 to leak to any portion other than the sound outlet 203 . The inside cover 210 also has screw holes 213 for screw cramps provided thereon. [0100] As shown in FIG. 16 , the assembly 220 has a speaker 224 mounted thereon with its front exposed, and also has a battery accommodating section 205 for accommodating the battery (not shown). Furthermore, the assembly 220 has mounting holes 226 provided thereon. [0101] Here, the speaker 224 mounted on the assembly 220 has a sound producing section 224 a which is almost circular and a connecting section 224 b to which a lead 224 c for conveying the sound signal to the sound producing section 224 a is connected. And a speaker accommodating section 227 for accommodating the speaker 224 of the assembly 220 has a form matching with the form of the speaker 224 , wherein a circular section 227 a for accommodating the circular sound producing section 224 a of the speaker 224 is connected to a rectangular section 227 b for connecting the connecting section 224 b of the speaker 224 . [0102] Furthermore, as shown in FIG. 16 , the outside cover 230 has the sound outlet 204 and the opening 233 for accommodating the battery described so far provided thereon, and further has mounting holes 234 and battery charging electrodes 235 provided thereon. To assemble the inside cover 210 , assembly 220 and outside cover 230 , the assembly 220 is sandwiched between the inside cover 210 and outside cover 230 , and screws are inserted into the mounting holes 234 of the outside cover 230 and mounting holes 226 of the assembly 220 from the mounting holes 234 side so as to be screwed in the screw holes 213 of the inside cover 210 . [0103] FIG. 17 is a plan view showing the inner face of the outside cover 230 (refer to FIGS. 5 and 6 ) constituting the downside housing 200 (refer to FIGS. 1 and 2 ). [0104] Here, the mesh 231 is adhered to the portion to which the front face of the sound producing section 224 a of the speaker 224 (refer to FIG. 16 ) is applied as previously described, and the gasket 232 is adhered to the surroundings of the mesh 231 . The gasket 232 has a circular portion 232 a and a rectangular portion 232 b projecting from the circular portion. The circular portion 232 a of the gasket 232 covers the surroundings of the sound producing section 224 a (refer to FIG. 16 ) of the speaker 224 , and is intended to prevent occurrence of unpleasant noise due to reduction in sound pressure and resonance caused by the voice emitted from the sound producing section 224 a leaking to any portion other than the sound outlet 204 (refer to FIG. 16 ) having the mesh 231 adhered thereto. [0105] The rectangular portion 232 b of the gasket 232 plays a role of clogging up the rectangular section 227 b having the connecting section 224 b of the speaker 224 placed thereon of the speaker accommodating section 227 shown in FIG. 16 and acoustically separating a space formed on the backside of the speaker 224 (described later) from the front face of the sound producing section 224 a in collaboration with the circular portion 232 a. Details will be described later. [0106] FIG. 17 shows the opening 233 for accommodating the battery and the mounting holes 234 for screw cramps as previously described. [0107] FIG. 18 is a plan view showing the downside housing. FIG. 19 is a sectional view along an arrow A to A shown in FIG. 18 . FIG. 20 is a sectional view along an arrow B to B shown in FIG. 18 . [0108] FIG. 18 is a diagram for showing lines of sections in FIGS. 19 and 20 , and a repeated description of the inner face of the downside housing will be omitted. The structure related to the sound outlet 203 will be described below. [0109] As shown in FIGS. 19 and 20 , the sound producing section 224 a of the speaker 224 is facing the sound outlet 204 side, and the gasket 232 consisting of the circular portion 232 a and rectangular portion 232 b shown in FIG. 17 is sandwiched between the sound outlet 204 and the speaker 224 . And some spaces 228 are formed on the backside of the speaker 224 and lead to the opening 225 (refer to FIG. 15 ) of the assembly 220 , where the opening 225 leads to another sound outlet 203 . Here, the gasket 232 is intended to prevent the reduction in sound pressure of the voice emitted from the sound outlet 204 and occurrence of the unpleasant noise due to the sound emitted from the sound producing section 224 a of the speaker 224 leaking to the surroundings. The gasket 232 plays another role, that is, the role of preventing the sound emitted from the sound producing section 224 a of the speaker 224 from running round to the spaces 228 on the backside of the speaker 224 . [0110] In the case of a structure for emitting the sound from the speaker 224 only to the front face of the sound producing section 224 a , there is no problem even if the sound runs round to the spaces 228 . In this case, it is sufficient only if the gasket 232 exists in the circular portion 232 a surrounding the sound producing section 224 a of the speaker 224 . As opposed to this, in the case of the structure shown here, the sound emitted forward from the sound producing section 224 a of the speaker 224 is emitted from the sound outlet 204 , and the sound emitted on the backside of the speaker 224 is emitted from another sound outlet 203 via the spaces 228 . Here, the voice emitted forward from the sound producing section 224 a of the speaker 224 and the voice emitted from the backside of the speaker 224 to the spaces 228 are mutually in opposite phases, and so they are mutually canceled if the voice emitted from the sound producing section 224 a runs round to the spaces 228 . The sound pressure of the voice emitted from the backside of the speaker 224 into the spaces 228 is not so high from the beginning. Therefore, if this voice is further canceled, only the voice of insufficient sound pressure can be obtained consequently from the sound outlet 203 . Here, not only the circular portion 232 a but also the rectangular portion 232 b is provided to the gasket 232 , and the voice emitted from the sound producing section 224 a of the speaker 224 is thereby prevented from running round to the spaces 228 on the backside of the speaker 224 so as to emit the voice of sufficient sound pressure also from the sound outlet 203 on the backside of the speaker 224 . [0111] FIG. 21 is a further exploded view showing the inside cover 210 (refer to FIGS. 5 and 6 ) constituting the downside housing 200 (refer to FIGS. 1 and 2 ). [0112] The inside cover 210 is consisting of a frame 210 A having holes 219 provided to the portions equivalent to the push buttons and a push button sheet 210 B having the push buttons made of a hard material of which locations corresponding to the holes 219 are formed like projections with the push buttons linked by a flexible sheet. The flexible sheet is made of a half-transparent material, and a material for dispersedly transmitting light is used for the push buttons. As shown by the arrow in FIG. 21 , the push button sheet 210 B has the face shown in FIG. 21 placed on the frame 210 A in a direction of the frame 210 A contacting the face shown in FIG. 21 , and the push buttons 201 of the push button sheet 210 B are fitted in the holes 219 of the frame 210 A. [0113] The frame 210 A has a small microphone 214 provided at a position on the backside of the mouthpiece 202 shown in FIG. 1 . [0114] The frame 210 A has light shielding walls 217 and 218 adhered to the inner face thereof. [0115] The push button sheet 210 B has a long hole 215 and a slit 216 formed at the locations corresponding to the light shielding wall 218 . [0116] FIG. 22 is a diagram showing the inner face of the inside cover 210 in a state of placing the push button sheet 210 B on the frame 210 A. [0117] The light shielding wall 218 is provided at a position surrounding the call button 201 a of the multiple push buttons 102 . The light shielding wall 217 is provided at a position surrounding another call button 201 b in collaboration with the light shielding wall 223 provided on the assembly 220 (refer to FIG. 15 ). [0118] The light shielding wall 218 is intended to prevent the push buttons other than the call button 201 a from lighting up due to a leak of the light from the LED 222 a as one of the multiple LEDs 222 on the assembly 220 shown in FIG. 15 when the LED 222 a emits light and lights up only the call button 201 a. [0119] The light shielding wall 217 surrounds the call button 201 b in collaboration with the light shielding wall 223 provided on the assembly 220 (refer to FIG. 5 ), and is intended to prevent the leak of the light to the push buttons other than the call button 201 b when only the two LEDs 222 b of the multiple LEDs 222 on the assembly 220 shown in FIG. 5 emit light and light up only the call button 201 b. [0120] As previously described, if the multiple LEDs 222 except the LEDs 222 a and 222 b on the assembly 220 emit light all together, the multiple push buttons including the two call buttons 201 a and 201 b lined up on the push button sheet 210 B light up all together. [0121] FIG. 23 is a plan view showing the downside housing. FIG. 24 is a sectional view along an arrow A to A shown in FIG. 23 . FIG. 25 is a partially enlarged view enlarging and showing the inside of a circle R 1 shown in FIG. 24 . FIG. 26 is a sectional view along an arrow B to B shown in FIG. 23 . FIG. 27 is a partially enlarged view enlarging and showing the inside of a circle R 2 shown in FIG. 26 . [0122] If only the LED 222 a shown in FIG. 25 emits light, the call button 201 a lights up, and the light of the LED 222 a is shut out by the light shielding wall 218 and is not conveyed to the other push buttons so that the push buttons other than the call button 201 a remain unlit. [0123] The call button 201 a has been described here. However, it also applies to the other call button 201 b. [0124] Here, the call button 201 a is the push button which lights up on receiving the ordinary call only with voice and is pushed to start the call. The other call button 201 b is the push button which lights up on receiving the video-phone call and is pushed to start the video-phone call and image communication. On receiving a call, the user of this portable telephone can see whether it is the ordinary call only with voice or the video-phone call and which call button should be pushed by checking which of the two call buttons 201 a and 201 b is lighted up. In addition, all the push buttons light up if a folded portable telephone is opened in timing other than receiving a call so as to facilitate use in a dark place. [0125] The portable telephone has been described above as an example of the portable terminal apparatus according to the present invention. However, any specification of communication for implementing a telephone function of the portable telephone is applicable to the present invention, such as PHS (Personal Handy Phone System). [0126] Also, the folding type portable telephone has been described above as an example. However, the present invention is not only applicable to the folding type portable telephone but also to any form of the portable telephone. [0127] Furthermore, the present invention is not only applicable to those in the form of the portable telephone but also to any form of the portable terminal apparatus with the telephone function, such as the portable terminal apparatus in a form similar to a PDA (Personal digital Assistance) or a wrist watch.

The present invention relates to a portable terminal apparatus with a telephone function such as a portable telephone, which has a structure capable of efficiently emitting a voice from a speaker from both a front face and a backside of a housing. The portable terminal has: a first cover that includes a first sound outlet for emitting a sound from the speaker through the front of the portable terminal apparatus; a second cover that includes a second sound outlet for emitting a sound from the speaker through the back of the portable terminal apparatus; and a gasket accommodated at a position sandwiched between the first cover and the speaker.

This is a continuation of application Ser. No. 489,768, filed on Feb. 26, 1990 which is a continuation of Ser. No. 217,102, filed on July 8, 1988 which is a continuation of Ser. No. 096,304, filed on Sept. 8, 1987 which is a continuation of Ser. No. 690,062, filed on Jan. 9, 1985, all of which have been abandoned. BACKGROUND OF THE INVENTION The invention relates to a method for the transmission of data from one station to another by way of a data bus to which several stations are connected in parallel such that signals emitted by all the stations are linked to the data bus via an OR function in which all the stations receive the signals present on the data bus and at least some stations independently of one another access the data bus for a data transmission when data to be transmitted are present and the signal present on the data bus corresponds to the logic value "0" for a specified time period. For a data transmission a signal corresponding to the logic value "1", which identifies the condition of the data bus as "occupied", is transmitted periodically during a specified initial part period. A signal which corresponds to the value of the data bit to be transmitted is then transmitted during a specified second part period and then a signal corresponding to the logic value "0" on the data bus is transmitted during a specified third part period. Such a method is known from U.S. Pat. No. 4,418,386, and uses a transmission medium which can transmit at least two logic states, for example a twisted pair of wires or a coaxial cable or also, for example, a glass fiber connection. This enables a data transmission system to be accomplished particularly inexpensively. However, in the case where several stations access the bus at the same time, which station finally retains the access to the bus must be resolved. This problem can be solved more easily if several parallel transmission lines are used for the data bus, but this then means higher expenditure for the connection which is also undesirable. In the arrangement as described in the above-mentioned U.S. Pat. No. 4,418,386, stations which are ready to transmit wait for an initial period of time after the end of the last operation on the data bus to see whether the bus remains in the quiescent state, and if this is the case, a character is transmitted via the bus after a second period of time. This is achieved by the fact that after expiration of the second time interval a transmitting station brings the logic value "1" to the bus after it previously had the logic value "0" in the quiescent state. A certain time after this, a data character is transmitted and then the data bus returns to the quiescent state, in which case the transmitting station, or stations, monitors the state of the data bus again for a given time. All times or time intervals are dependent in this case on the internal clock generators of the respective stations which can exhibit relatively large scatters in their frequency. In order to obtain unambiguous states particularly in the case of simultaneous access by several stations, the individual times must, on account of these tolerances, obey certain conditions as pointed out in U.S. Pat. No. 4,418,386. This leads to troublesome and time-consuming control in the individual stations which therefore is also expensive. U.S. Pat. No. 4,429,384 also describes a method and an arrangement in which the data is also transmitted via an individual transmission circuit, such as, for example, a twisted pair of wires or a glass fiber section. The transmission takes place in blocks, in which case a block is preceded by a start bit during which the data bus is brought to the logic value "1". The logic values of the data bits are represented in this case by different durations of a given signal state on the data bus, in contrast to the first-named arrangement as described in U.S. Pat. No. 4,418,386 in which the logic value of a bit is determined by the signal value itself on the data bus. In the case of the arrangement as described in U.S. Pat. No. 4,429,384 it is also necessary that the frequencies of the clock generators in the individual stations are defined within certain limits, in which situation several classes of frequencies are also possible for the clock generators. Then, however, at the beginning of a data transmission the transmitting station has to ascertain first of all to which class of clock frequencies the called station belongs. This transmission method, too, is cumbersome and relatively expensive. It is the aim of the invention to outline a method of the type mentioned in the preamble which at low expense makes it possible to transmit data between stations with considerable clock frequency differences, without the clock frequency of the called station being known in the transmitting station at the start of a transmission. The invention achieves this aim by transmitting signals during three partial periods whose durations have a fixed relationship one to the other. In all stations the length of the entire period and hence the position of the partial periods within it is determined from the signal transfers on the data bus at the beginning of two successive first part periods and the state of the data bus is determined from the signal on the data bus during the first partial period and the logic value of the transmitted data bit is determined during the second part period. Because of the fixed relationships between the part periods and because of the joining together without a pause and especially because in all stations the lengths or positions of the part periods are automatically determined practically independently of clock generators inside the stations, there are no synchronization problems. The part periods can be determined from the signal on the data bus by simple means, as is shown later. This creates a very inexpensive data transmission method which can also be profitably used in simple applications. It is advantageous that the information on the data bus directly indicates whether the data bus is occupied because this occupancy information is uniquely allocated to a certain point within the period. This means that waiting times and special control sequences are not necessary or are very simple. In order that the length of the entire period for a data transmission can be simply measured at the beginning of a data transmission it is advisable, according to one embodiment of the invention, that at least one period without transmission of a bit should be included before the beginning of a data transmission. Because in this case the transmitting station generates a definite signal for occupancy of the data bus each time at the start of the first part period, the length of the transmission period can be determined from the first two successive signals of this kind, and is thus fixed at the beginning of the second period and can be used to evaluate data information in the second part period. This is based on the fact that at the end of a transmission the data bus constantly carries a signal corresponding to the logic value " 0" until a station begins a renewed transmission. Another possibility consists in also maintaining the synchronization during the transmission pauses. In one embodiment of the invention this is achieved by subdividing the first part period into two sub-periods. During the first sub-period a signal corresponding to the logic value "1" is always transmitted on the data bus even outside of a data transmission while during the second sub-period a signal corresponding to the logic value "1" is transmitted via the data bus only during a data transmission. A station that is ready to transmit accesses the data bus only when the signal on the data bus in the second sub-period corresponds to the logic value "0". In this case, therefore, the first part period is subdivided into two regions the first of which is used for synchronization and the second for occupation of the bus. The generation of the signal corresponding to the logic value "1" on the data bus may permanently come from one of the stations which, for example, is available only for the transmission of this signal within the first sub-period, or the stations alternate in that after completion of a data transmission in the first sub-period each station continues to transmit a signal corresponding to the logic value "1" until another station occupies the bus and thus takes over the synchronization. In this case this new accessing station can continue to operate with the same period length in accordance with the preceding constant synchronization, but it can also generate a new period length. In the latter situation, of course, it is advisable once again to insert at least one period without transmission of a bit before the start of a data transmission. A particularly suitable choice of the lengths of the part periods or the sub-periods is for the second and the third part periods or the sub-periods to have the same durations of 1/4 of the period in each case. Such a ratio is particularly easy to implement. To obtain the most trouble-free evaluation of the information transmitted via the data bus it is expedient that the status of the data bus and the logic value of the transmitted bit should be determined in each case approximately in the middle of the part period or sub-period concerned. Such determination or sampling times are also very easy to implement. In many cases a transmitting station calls another station to collect information from the latter and transfer it to the transmitting station. For this, the desired other station can be addressed by the transmitting station through the data transmission and the transfer wish communicated. After this the initially transmitting station terminates the data transmission, and as soon as the data bus is signalled as being unoccupied, the previously addressed station begins the data transmission. In a further embodiment of the invention, however, there is also a simpler possibility as follows: even if, in the first part period of the second sub-period, a signal corresponding to the logic value "1" is transmitted by a first station via the data bus, a second station addressed by data sent from this first station transmits via the data bus, during the second part period of at least one period, a signal corresponding to the logic value of a data bit to be transmitted, and the first station during the second part period of this period feeds a signal corresponding to the logic value "0" to the data bus. It this way it is easy to conduct a dialogue between two stations. Embodiments of a station for implementation of the invention method are also described. BRIEF DESCRIPTION OF THE DRAWINGS Embodiment examples of the invention are explained in greater detail below with the aid of the drawings which show FIG. 1 the connection of a number of stations to a data bus in the form of a ring; FIG. 2 signal waveforms on the data bus in the case of different operating states; FIG. 3 a send-side sequence control in a station; FIG. 4 an arrangement for the evaluation of the signal on the data bus in a station; FIG. 5a to 5c time-dependency diagrams of a number of signals of the arrangement in FIG. 4; FIG. 6 another arrangement for the evaluation of the signal on the data bus in a station; FIG. 7 Shows a flow diagram for the programming of a microprocessor for sending and receiving data; FIG. 8 Shows variations of the sequence compared with that in FIG. 7 where no special clock generator generates the signal transition at the beginning of each period; FIG. 9 Shows an example of operation when during pauses in transmission of information bits no signal transitions are generated on the data bus. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows six stations A to F represented symbolically as blocks. Both the output and the input of each of these stations A to F is connected to a data bus 1 which is shown here as a closed loop. The use of an open loop is just as possible however, and a star-shaped structure can also be used. The data bus 1 may comprise, for example, a coaxial cable or a twisted pair of wires, but it may also be in the form of a glass fiber connection for the transmission of optical signals. In the latter case, however, such a glass fiber connection is frequently interrupted in each station and leads there on the reception side to a light receiver which controls a light transmitter on the output side, the latter transmitting both the light signals received and the signals generated in the station concerned. The waveforms of the signals on the data bus for different operating states are shown in FIG. 2. Line a shows a clock signal inside the station, which is explained in more detail with the aid of FIG. 3. Line b presents a survey of the individual part periods of a total period. Each total period embraces the part periods T1, T2 and T3, and after the end of the third part period T3 the first part period T1 of the next total period begins immediately. In the example shown the durations of the second and third part periods T2 and T3 each amount to a quarter of the total period so that the first part period T1 takes up half a total period. Other numerical ratios are also possible, but the ratios of the durations of the part periods as shown are easy to implement in practice as will be explained later. In the example of FIG. 2, the first part period T1 is subdivided into two sub-periods U1 and U2. Both are of the same length here and thus amount to a quarter of the total period, the same as the second and third part periods T2 and T3. This choice of durations for the sub-periods U1 and U2 is also made solely on the basis of ease of technical implementation, whereas other numerical ratios are also possible. The general situation of the signals on the data bus during a data transmission is illustrated in lines d and e. Here, therefore, during the first part period T1 there is a low signal on the data bus, in which case it is assumed that with an electric cable as the data bus a ground-connected transistor with open collector is provided on the output side in each station while at a single point a load resistor is connected against a positive operating voltage. In the case of a glass fiber connection the lower state of the line means that a light signal is being transmitted, while in the upper state of the line no light signal is present. Thus a wired OR-function is achieved in which a low signal indicates the value "1". The low state of the lines in lines d and e during the first part period T1 means that a data transmission is taking place and the bus is thus occupied. This is immediately recognizable by all the stations connected to the data bus. The state of the lines in lines d and e of FIG. 2 differes only during the second part period T2 in which the value of the transmitted data bit is indicated. For example, with a signal waveform as in line d, a data bit with the logic value "0" is being transmitted and with the signal waveform of line e a data bit with the logic value "1". During the part period T3 there is a high signal on the data bus here in every case. When the signal is received on data bus 1, all the connected stations determine from the negative signal edge at the beginning of the first part period T1 of two successive total periods the duration of the total period and thus the position of part period T2 from the given ratio of the individual part periods to one another. In the example shown, therefore, the second part period T2 begins half a determined total period after the negative signal edge of the data bus. Inside a further quarter of the total period the signal on the data bus can then be evaluated to determine the value of the transmitted data bit. If no data transmission takes place, the signal on the data bus may be permanently high. The start of a new data transmission is then obtained from the first negative edge of the signal on the data bus. If this is taking place from a different station from that of the preceding data transmission, as will generally be the case, the duration of the total period can vary depending on the clock frequency inside the station. This can easily be taken into consideration, as is explained later. Another possibility is to transmit an alternating signal, such as that shown in line c of FIG. 2, in addition to a data transmission on the data bus. Here, therefore, a low signal is produced on the data bus during the first sub-period U1 so that all the stations are constantly allocated a definite duration of the total period and thus all the stations are constantly synchronized. This signal can be generated by a certain station, for example station A in FIG. 1, or each station which has transmitted data then sends a signal like that of line c in FIG. 2 on the data bus until another station begins a data transmission. The start of a data transmission is identified by the fact that a low signal is now generated on the data bus during the second sub-period U2 so that a signal waveform like that of lines d or e in FIG. 2 is produced, depending on the value of the transmitted data bit. In this case, therefore, the signal state on the data bus during the second sub-period U2 indicates the state of the data bus, i.e. whether it is free or occupied for a data transmission. Because, before a data transmission, i.e. in the quiescent state, all stations receive a signal on the data bus corresponding to that of line e in FIG. 2, a station which begins a data transmission can perform this with the same or at least essentially the same period length which was fixed by the preceding signal on the data bus. The transmission of a synchronized signal via the data bus, in addition to a data transmission, is particularly favorable when allowance has to be made for the fact that several stations can access the data bus simultaneously and the decision as to which station finally retains the access is made in a known manner during the transmission because then the data bits of all the stations are simultaneously present on the data bus and a data bit with the logic value "0" from a first station is masked by a data bit with the logic value "1" from a second station, and this identifies the first station and terminates the access to the data bus. DESCRIPTION OF A TRANSMITTER-END SEQUENCE CONTROL A possible arrangement which can generate the signals illustrated in lines c to d of FIG. 2 and which can represent a part of stations A to F in FIG. 1, is shown in FIG. 3. A clock generator 20, which generates the processing clock pulse in the station concerned, supplies on line 121' a clock signal which corresponds to the signal waveform in line a of FIG. 2 and which, preferably, is derived from a higher-frequency clock signal by division. This clock signal on line 121' is fed, in addition to a D-flip-flop 6, which is described subsequently, to a sequence control 4 which in the simplest case comprises a binary counter. This sequence control 4 successively produces at the outputs 3, 5 and 9 a send-control signal decoded from the counter reading,--at output 3 during the first sub-period U1, at output 5 during the second sub-period U2 and at output 9 during the second part period T2. The signals follow one another immediately and alternate in each case, for example, with the leading edge of the clock signal on line 121', as illustrated in FIG. 2. With the next leading edge of the clock signal on line 121' after the signal at the output 9 during part period T2, a signal does not appear at any of the outputs during a clock period; this corresponds to the part period T3, and with the following leading edge of the clock signal, a signal appears again at output 3, etc. Each of the outputs 3, 5 and 9 is connected to the one input of a corresponding AND element 10, 12 and 14 respectively, the outputs of which are combined via the OR element 8 and fed to the D-input of the D-flip-flop 6. The other input of the AND element 10 is connected to a switch 22 which can connect this input either to a constant signal corresponding to the logic value "1" or to the line 17 which, moreover, is permanently connected to the other input of AND element 12. The signal on line 17 is generated by an OR element 16 either when a signal which is generated, for example, by the arrangement shown in FIG. 4 appears on line 15 or when a signal which is generated by processing device 100 (not shown in detail) appears on line 13. This processing device 100 contains, for example, measuring equipment for a quantity being measured and a converter which converts the measuring signal into a digital value and delivers it bit-serially over the length 11. This line 11 which, therefore, carries the data signal to be transmitted is connected to a second input of the AND element 14 the third input of which is connected to the output 7 of the D-flip-flop 6. This output 7, moreover, is coupled to data bus 1 via an inverting amplifier 18 which is constructed in such a way that at least in the first two part periods it forms an inclusive-OR operation of the signals generated by it with the signals present on the data bus and which, in the simplest case, consists of a transistor in basic emitter circuit with open collector, connected to the data bus 1. The function of the arrangement illustrated in FIG. 3 is as follows. If it is assumed first of all that no data is to be transmitted from the station in which this arrangement is present, then a signal corresponding to the logic value "0" is present both on line 13 and on line 15 and therefore on line 17, so that the AND element 12 is blocked. If, furthermore, the switch 22 is in the position as shown, the AND element 10 is permanently unblocked and passes on the signal, which appears at the output 3 of the sequence control 4 during the first sub-period U1, via the OR element 8 to the D-input of the D-flip-flop 6. Because this D-flip-flop 6 is edge-controlled at the clock input, it takes over the signal present at the D-output on each occasion with the next leading edge of the clock signal on the line 121 to the output 7 so that finally a signal appears on data bus 1 like that illustrated in line c of FIG. 2, except that it is displaced in fact with respect to line b by a phase of the clock signal illustrated in line a; this, however, is not important for the further function so that the illustration in FIG. 2 continues to form the basis. When, however, switch 22 is in the lower position and connects the other input of the AND element 10 to the line 17, all AND elements 10, 12 and 14 are blocked except for a data transmission from the relevant station, and the signal present on the data bus is constantly high and a low signal generated from another station is not influenced by this station. This low state can be assumed when the station has detected that another station is becoming a send operation. It is also possible that the upper state applies to one station and the lower state to all the others. To prepare for a data transmission, a signal corresponding to the logic value "1" is generated on line 17, and in fact by a corresponding signal on line 13 by the processing unit 100 when the latter is called up, for example, for a data transmission in conversational mode by signals transmitted by another station. In this case, therefore, the data bus is still occupied by this other station, and during the second part period of one or more successive total periods this other station transmits a signal corresponding to the logic value "0" so that it can recognize the logic values of the data bits transmitted by the arrangement described here. The control processes required for this are not explained separately in detail here because they are not essential for the invention. Normally, an appropriate signal is generated on line 15 by the arrangement of FIG. 4 when the bus is unoccupied and data for transmission are present. For the rest this control may also be taken over by the processing unit 100 which means that there will then be no OR element 16 in the arrangement according to FIG. 3 and the line 13 is connected directly to line 17. In the case of a signal corresponding to the logic value "1" on line 17 both the AND element 10 and the AND element 12 are unblocked irrespective of the position of switch 22 so that the signals at the outputs 3 and 5 of the sequence control 4 are fed during both sub-periods U1 and U2 to the D-input of the D-flip-flop 6 so that signals corresponding to line d or line e in FIG. 2 are generated on the data bus 1, depending on the data to be transmitted which is fed to AND element 14 via line 11. If a datum with the logic value "0" is to be transmitted, AND element 14 is blocked and the D-flip-flop 6 generates a high signal at output 7 only during two successive clock phases of the clock signal on line 121 so that a signal corresponding to line d in FIG. 2 appears on data bus 1. If, however, the signal on data line 11 is high, the signals at all three outputs 3, 5 and 9 are fed to the D-input of the D-flip-flop 6 because when the signal appears at output 9 the flip-flop 6 is still set and thus the righthand input of AND element 14 is also released. As a result, a low signal corresponding to line e in FIG. 2 appears on data bus 1 during three successive clock phases. The righthand input of the AND element 14 could also be connected to line 17, but the connection as shown has the advantage that the high signal on line 17 can already disappear after the end of the signal at output 5, i.e. already after the second sub-period U2, and it is still guaranteed that a valid datum is transmitted during the subsequent part period T2. DESCRIPTION OF AN ARRANGEMENT FOR THE EVALUATION OF THE DATA BUS SIGNAL In the arrangement illustrated in FIG. 4 for the reception and evaluation of the signals on data bus 1 it is assumed that data bus 1 comprises an electrical connection, e.g. a twisted pair of wires or a coaxial line which contains therefore a reference conductor and a signal conductor. The reference conductor is connected to the reference point of the arrangement as in FIG. 4, and the signal conductor leads via a rectifier 102 to a high-capacitance charging capacitor 103. From this connection 104 with the charging capacitor 103 is tapped the operating voltage U B for the electronic parts of the station of which the arrangement shown in FIG. 4 forms a part. In this way this station does not then need its own power supply. The signal conductor of data bus 1 further leads to an inverting amplifier 101 which is suitably provided with a defined switching threshold and at the output 1a supplies a defined binary signal with steep transitions irrespective of the shape of the signal on data bus 1. The inverted data bus signal on line 1a which has a positive signal edge at the beginning of every new period of the signals on data bus 1 leads to the clock input of an edge-controlled D-flip-flop 32, the D-input of which is permanently connected to a signal corresponding to the logic value "1". If, therefore, a positive edge occurs on line 1a, the D-flip-flop 32 is set and then supplies on the output line 33 a signal corresponding to the logic value "1". These processes are illustrated in more detail in FIG. 5a. Line 33 leads to the data input of a two-stage shift register 34 which receives at the clock input a clock signal generated by clock generator 20 on line 21 the frequency of which is higher than that of the clock signal on line 121 in FIG. 3. With the first positive edge of this clock signal the value "1" present on line 33 is transferred into shift register 34, and a positive signal appears on the output line 35. This resets the D-flip-flop 32. Furthermore, the line 35 leads via the NOR element 36 to the enable input CE of a counter 30, which is described subsequently, and blocks its counting operation. In addition, line 35 leads to one input of an AND element 38 the other input of which is connected to the line 49 from the D-flip-flop 48 and receives first of all a logic "0". With the leading edge of the next clock signal on line 21 the logic "1" is further shifted in the shift register 34 so that a signal corresponding to the logic value "1" appears on line 37. This resets the counter 30 via reset input R to a defined initial position or zero position as the case may be and also resets the D-flip-flop 48 so that line 49 now carries a "1", but line 35 already has a "0" again. In addition, line 37 also leads via the NOR element 36 to the blocking input CE of counter 30 and keeps the latter blocked. With the next leading edge of the clock signal on line 21 the logic "1" on line 37 then also disappears so that now counter 30 is released to count up from the initial position with the clock pulse on line 21. There now passes a relatively long time with respect to the operations illustrated on the left in FIG. 5a before the signal on data bus 1 becomes positive again, which however does not trigger any further operations. After a further relatively long time a negative edge appears then again in the signal on data bus 1 which again is asynchronous to the clock signal on line 21, i.e. can occur again at any point between two positive edges of this signal. The D-flip-flop 32 is again set with this edge of the signal on data bus 1, and with the next positive edge of clock signal 21 a positive signal again appears on line 35, but which this time thanks to the also positive signal on line 49 generates via the AND element 38 a corresponding signal on line 39 which sets counters 40, 42, 44 and 46 to a position which is determined by means of the multiple connection 31 of counter 30 at the moment the signal 35 appears. This content of counter 30 is a measure of the period length of two successive like signal changes on data bus 1, when the frequency of clock generator 20 is assumed to be constant, and the individual part periods or sub-periods can be derived from this counter position of counter 30. With the next edge of clock signal 21, counter 30 is now reset to the initial position and then begins to count afresh, whereby the duration of the next period is measured. This measurement yields in fact somewhat too short a time between two successive signal edges on data bus 1 because during the two successive signals on lines 35 and 37, i.e. during two periods of clock signal 21, the counter is blocked, and furthermore a certain inaccuracy arises due to the fact that the edges of the signal on data bus 1 are asynchronous to the clock signal 21, but the total error produced by this is small if the frequency of the clock signal 21 is much higher than the frequency of the signals on the data bus. Typical values of the clock signal 21 are, for example, a few MHz, whereas the frequency of the signal on the data bus amounts, for example, to a few kHz. The capacity of the counter 10 must then be appropriately designed, i.e. must embrace approximately 10 to 12 divisor stages in one binary counter. Counters 40, 42, 44 and 46 are now set not to the same position which counter 30 has reached at the moment the signal is on line 39 or 35, i.e. immediately after the negative signal edge on data bus 1, but to a position shifted by a few places with respect to this. In the case of counter 40 this position is shifted by three places, i.e. the bit with the fourth lowest significance of counter 30 determines the position of the least significant bit of counter 40 etc., so that the three least significant bits of counter 30 are not taken into account for this. Counter 40 receives the clock signal 21 at a down-counting input and now counts down from the set position to the zero position at which a "1" is generated on line 41. Because the counter position is shifted by 3 bits, this takes place after about an eighth of the number of clock signals on line 21 which the counter 30 had previously counted during a period of the data signal on data bus 1, i.e. after an eighth of such a period and therefore approximately in the middle of the first sub-period U1 in FIG. 2. These relationships are illustrated in FIG. 5b in a much compressed time scale compared with FIG. 5a. At time t0 there occurs the first edge in the signal on data bus 1 which is shown on the left in FIG. 5a and represents the beginning of a data transmission. This assumes the situation that outside of a data transmission there is constantly a high signal on data bus 1 or that with the start of a data transmission from a new station a jump occurs in the period length during the next transmission so that a full period length has to be measured first of all in which no transmission of a datum can take place. As was explained with the aid of FIG. 5a, from this first signal edge on data bus 1 at time t0 to the next signal edge at time t1 only counter 30 is working to measure the duration between these two edges, while counters 40, 42, 44 and 46 are in the zero position and the lines 41, 43, 45 and 47 constantly carry a high signal, as FIG. 5b shows. Only the D-flip-flop 48 has been reset immediately after the signal edge at time t0 so that line 49 assumes a high potential at this point in time. With the signal edge occurring on data bus 1 at time t1 the counters 40, 42, 44 and 46 are set to a fraction of the position of counter 30 reached at this time; in fact, as already explained, counter 40 is set to a value shifted by three places, corresponding to an eighth of the total period length, while counters 42 and 44 are set to a value shifted by two places corresponding to a quarter of the total period length and counter 46 is set to a value shifted by one place corresponding to half the total period length. With the setting of counters 40, 42, 44 and 46 which thus at the same time represent memories for the counter position of counter 30 reached at this moment, the signals at the outputs 41, 43 45 and 47 of these counters go to zero, as shown in FIG. 5b. Because the outputs 41, 43 and 45 lead to a counting-release input of the counter which follows in each case, at the beginning only counter 40 counts the clock signal 21 which for the rest is also fed to the counting inputs of the other counters. When counter 40 after an eighth of the total period length, i.e. approximately in the middle of the first sub-period, has reached its zero position again and the signal at output 41 again becomes high, this counter is blocked by this output signal and, on the other hand, counter 42 is released which now counts for one quarter of the total period length and thus after three eighths of the total period length, i.e. in the middle of the second sub-period, reaches its zero position as a result of which the signal at output 43 becomes high. This signal, on the other hand, is also the first sampling signal S1 which is fed to the clock input of an edge-controlled D-flip-flop 50 the D-input of which from line 1a receives the inverted signal of the data bus 1. Because the latter is low at this time, the inverted signal is high, and the D-flip-flop 50 is set, as the result of which output 51 carries a high "bus occupied" signal. This signal is also fed among other things to the processing unit 100 which is indicated only schematically here and which can use this signal for appropriate control purposes. The high signal at output 43, on the one hand, blocks further counting of counter 42 and, on the other, enables the counting of counter 44 which, after a fourth of the total period length, i.e. approximately in the middle of the second part period, reaches its zero position and then generates a high signal at output 45. This signal blocks further counting of counter 44 and, on the other hand, represents the second sampling signal S2 which is fed to one input of an AND element 52 the other input of which receives the "bus occupied" signal on line 51 and the output of which is connected to the clock input of a further edge-controlled D-flip-flop 54. Because the sampling signal S2 in the arrangement shown here can, of course, in the normal course of events occur only when the "bus occupied" signal is present, the AND element 52 acts here essentially as security against disturbed or wrongly triggered sequences of the counting arrangement of counters 40, 42 and 44 and can, where appropriate, also be omitted, in which case the sampling signal S2 leads directly to the clock input of the D-flip-flop 54. The D-input of flip-flop 54 is also connected to line 1a which carries the inverted signal to data bus 1. D-flip-flop 54 therefore evaluates the signal on the data bus approximately in the middle of the second part period, in which the signal is determined therefore by the logic value of the data bit transmitted on data bus 1, so that a signal corresponding to this logic value appears at output 55 of flip-flop 54 and is fed to the processing arrangement 100. In line 55 in FIG. 5b, the writing-in of the data bit value on data bus 1 is indicated by the intersection of the two lines. The sampling signal S2 passes moreover to a delay stage 56 which at output 57 issues a signal which is delayed with respect to the sampling signal and feeds it to the processing unit 100 in order to indicate to the latter from when a data signal fed via line 55 is valid. This delayed signal on line 57, designated as the data clock, is indicated in FIG. 5b merely by a vertical stroke for the sake of simplicity. With the next negative edge of the signal on data bus 1 at time t2 the same operations are repeated to evaluate the next transmitted data bit. The total period beginning at time t2 may simultaneously be the last total period of the transmission operation concerned, and it ends at time t3 at which, therefore, no further negative edge will then occur in the signal on data bus 1. Now counter 46 can come into operation, which had already begun to count previously when counter 44 had reached its zero position, but counter 46 could not yet reach its zero position because this would only occur one half of a total period length after the positive edge of the signal on line 45, i.e. approximately one eighth of the total period length after the beginning of the next following total period, as a result of which counter 46 was previously already set again into a position corresponding to the position reached by counter 30 at the end of a total period. Because at time t3, however, no new total period now begins, counter 46 is not reset again and can reach its zero position after the end of the last total period of the completed data transmission so that the signal at output 47 again becomes high. As a result, D-flip-flop 50 is now reset so that the "bus occupied" signal on line 51 becomes low again, and furthermore the edge-controlled D-flip-flop 48 receives a positive signal edge at the clock input so that this flip-flop flips back again and line 49 assumes a low signal again. Thus the arrangement is returned again to the rest position and can evaluate the start of a new data transmission. The arrangement illustrated in FIG. 4 also contains a part which generates the signal on line 15 for the send arrangement as per FIG. 3. This part contains a bistable circuit which contains two cross-coupled NOR elements 62 and 64, where the latter generates the signal on line 15. The other input of the NOR element 62 is connected to the output of an AND element 60 one input of which is connected to line 53 which, when the bus is not occupied, i.e. D-flip-flop 50 is reset, carries a signal which is the inverse of the "bus occupied" signal on line 51. The other input of AND element 60 is connected to a line 69 which comes from the processing unit 100 and which carries a signal corresponding to a logic "1" when the processing unit contains data for transmission, in which case, where necessary, other conditions can also be taken into account. This line 69 further leads via an inverter 68 to one input of a further AND element, of which another input receives the "bus unoccupied" signal on line 51 and a further input receives the second sampling signal S2 on line 45. The function of this arrangement is explained with the aid of FIG. 5c. It is assumed that the signal on line 69 which signals the desire of the processing unit 100 to send data can occur at any point in time, which is indicated on the left in FIG. 5c by the multiple edges of the corresponding signal. If this signal occurs in the case of an occupied bus, i.e. when the signal on line 51 is still high, the data bus must first become vacant and the appropriate signal on line 51 must become low, as a result of which the signal on line 53 becomes high. As soon as this happens or as soon as with a high signal on line 53 with the bus not occupied the signal occurs on line 69, the AND element 60 generates a logic "1" at the output. Thus, irrespective of the signal at the other input, the NOR element 62 generates a logic "0" at the output. Because at this moment the AND element 66 receives a low signal both via line 51 and from inverter 68, it generates a logic "0" at the output, so that the NOR element 64 receives such a signal at both inputs and generates a logic "1" at the output and thus on line 15. As soon as the sequence control 4 in FIG. 3 creates a signal at output 3 and the next edge of the clock signal 21 appears, a low signal is generated on data bus 1, it being assumed that switch 22 is in the bottom position, i.e. the signal on the data bus is high between successive data transmissions. As already described, the low signal lasts for half the duration of the total period because no datum can yet be transmitted in the first period since the duration of the period has to be evaluated first of all in all receiving stations. Furthermore, the other part of FIG. 4 also acts as a receiver in a similar way to as described before because the arrangement cannot differentiate from which source the signals on the data bus arrive. Thus in the next period in FIG. 5c, counters 40, 42, 44 and 46 begin to operate again. And also the line 51 changes its state and indicates an occupied bus. In addition, in the second part period of this and the next total period the signal on data bus 1 has a value which is dependent on the logic value of the data bit to be transmitted; this is indicated in FIG. 5c by a shaded area in the relevant signal on data bus 1. The data clock signal on line 57 is also generated as described before and can be used to feed the next data bit for transmission via line 11 in FIG. 3 to the AND element 14. To simplify the representation it is assumed that only two data bits are to be transmitted. The signal on line 69 can therefore disappear at any time during the third total period, in which the second and therefore last data bit is transmitted, as is shown in FIG. 5c by the multiply indicated edges in the waveform of this signal. The disappearance of this signal or the changeover to the logic value "0" has no effect on the AND element 60 because the latter has already previously received a logic "0" via line 53. On the other hand, the signal on line 51 has the logic value "1", and a second input of the AND element 66 now also receives via the inverter 68 a signal corresponding to the logic value "1". If now the second sampling signal S2 occurs, the AND element 66 delivers a logic "1" at the output as a result of which the signal on line 15 again becomes low by way of the NOR element 64. This makes it clear that the signal on line 69 must have gone to the logic value "0" no later than the end of the relevant period in order to prevent a new period with a further signal transition occurring on data bus 1. After the signal on line 69 has returned to the logic value "0" and no further signal transition occurs on data bus 1, counter 46 can reach its zero position after the end of the third period, as a result of which the signal on line 47 becomes high again and resets the D-flip-flop which means in turn that the "bus occupied" signal on line 51 becomes low again. This terminates the data transmission, and can be followed by the reception of another data transmission or the beginning of a further data transmission from this station. DESCRIPTION OF A FURTHER ARRANGEMENT FOR THE EVALUATION OF THE DATA BUS SIGNAL FIG. 6 depicts another arrangement for the reception and evaluation of the signals on data bus 1. These signals from data bus 1 are again passed via the inverting amplifier 101 to the line 1a where a high signal represents the logic value "1" on data bus 1. This signal goes, in the same way as in FIG. 4, to the clock input of the edge-controlled D-flip-flop 32 and the D-inputs of the D-flip-flops 50 and 54. With the negative edge of a signal on data bus 1, i.e. with the positive edge of the signal on line 1a, the D-flip-flop 32 is set and generates a high signal on line 33. Here, however, this signal goes to the D-input of a further D-flip-flop 72 which at the clock input receives the clock signal on line 21 and thus with the next leading edge of this clock signal generates a high signal at the output 73. This resets the D-flip-flop 32 and sets a counter 70 to an initial position, and at the same time the last reached reading of counter 70 is written into a register 74. This therefore fixes the storage of the counter reading of counter 70 and its resetting for a joint time, which is quite possible with many commercial counter and register modules, and furthermore the blocking of the counting of counter 70 at this point in time is dispensed with. Counter 70 corresponds to counter 30 in FIG. 4 and also has the same function. The line 73 also leads to a delay stage 80 which a short time after the positive signal on line 73 generates an output signal which is fed via the OR element 82 to the setting or loading input of a further counter 76 which with this signal takes over the output signal of register 74. The delay time of the delay stage 80 must correspond therefore at least to the transit time of the signals in register 74. Counter 76 now down-counts with the clock signal 21 until it has again reached the initial position as a result of which a signal appears at output 77. This output is connected via the OR element 82 once again to the setting input of counter 76 and to the counting input of a further counter 78. By means of the first connection the counter is thus set again to the position contained in register 74 and counts down again, and this operation is repeated several times. This multiple repetition is achieved by the fact that the register 74 does not directly take over the counter reading of counter 70, but the counter reading shifted by three binary digits, in which case the last three least significant bits are omitted. Instead of this, the register 74 may also take over the complete counter reading and feed this, shifted by three digits, to counter 76. In each case, counter 76 is set to a position which corresponds approximately to one eighth of the counter position of counter 70 so that during successive total periods of the signals on the data bus, counter 76 is set and returns to the initial position eight times. In fact, somewhat more than eight cycles of counter 76 take place in one period since the last digits of the reading of counter 70 are not considered; however, in the case of a sequence of total periods of equal length, as occurs with a data transmission, shortly after the start of the ninth cycle of counter 76, a signal occurs at the output of delay stage 80 on account of the start of the next period of the signal on data bus 1 so that counter 76 is then reset once again to the position derived from the counter position of counter 70 and is thus re-synchronized once again. The counter 78 receives a counting pulse with every cycle of the counter 76, when this reaches its initial position again, and it has at least eight counter positions and for every counter position an appropriately designated output at which a high signal appears when the counter finds itself in the like-designated counter position. At the beginning of a period of the signal on data bus 1, the counter 78 is set by the signal on line 73 to the position 0. Because the counter 76 issues a signal at output 77 every time after one eighth of the duration of the total period, the positions 0 and 1 of counter 78 represent the first sub-period, positions 2 and 3 represent the second sub-period and positions 4 and 5 represent the second part period. In this case the counter position 3 is approximately in the middle of the second sub-period and thus forms the first sampling signal S1, and counter position 5 begins approximately in the middle of the second part period and thus forms the second sampling signal S2. The sampling signal S1 goes to the clock input of an edge-controlled D-flip-flop 50 the D-input of which is connected to the line 1a and corresponds in function to the D-flip-flop in FIG. 4, i.e. the "bus occupied" signal appears again at its output 51. This signal is fed both to the processing unit 100 and to one of the inputs of AND elements 52 and 90. The first of these receives the second sampling signal S2 at the other input and leads to the clock input of the edge-controlled D-flip-flop 54, the D-output of which is also connected to line 1a and which corresponds to the like-designated D-flip-flop in FIG. 4, i.e. a signal appears at output 55 corresponding to the data bit value transmitted via data bus 1 which is also fed to processing unit 100. At the other input the AND element 90 receives a signal which occurs after the second sampling signal S2, for example the signal at output 6 or at output 7 of counter 78 of the combination of the two output signals at the output of OR element 84, this being indicated by the dashed lines, and a signal appears at output 91 of the AND element 90 which indicates that the data signal present on line 55 is valid and which is therefore designated the "data clock signal" and fed to the processing unit 100. In contrast to the arrangement in FIG. 4, the AND element 52 is necessary here because the sampling signals S1 and S2 are generated all the time, i.e. also outside of a data transmission. This also applies to the AND element 90 used here for the data clock. As already mentioned, with the arrangement as shown in FIG. 6 the two outputs of counter 78 for the counter positions 6 and 7 are combined by way of the OR element 84, and the output of this is designated like an output of the sequence control 4 in FIG. 3 by the FIG. 3, because in the arrangement according to FIG. 4 a signal appears at this output also in the third part period, that is before the start of the first sub-period of the following total period; this signal can be fed to the AND element 10 and therefore to the D-input of the D-flip-flop 6 in FIG. 3. The clock signal on line 21' is suitably derived from the signal on line 77 in FIG. 6 so that the changeover of counter 78 to the position 0 sets the D-flip-flop 6 in FIG. 3, and a low signal corresponding to a logic "1" is generated on data bus 1 by way of the inverting amplifier 18. This indicates the beginning of a new period during which by resetting by means of line 73 counter 78 is set into the position in which, however, it already finds itself so that in this way there is automatically synchronism between sending and receiving. Similarly, the outputs corresponding to counter positions 0 and 1 of counter 78 are combined by way of the OR element 86, the output of which is designated 5, and the outputs for counter positions 3 and 4 are combined by means of the OR element 88 the outputs of which are designated 9. All the outputs 3, 5 and 9 are connected as shown in FIG. 3 which means therefore that the sequence control 4 illustrated there can be omitted or is replaced by the counter 78 in FIG. 6. This results in a particularly simple and cost-saving arrangement in which, moreover, when data are being sent from the station concerned, of which the arrangement in FIG. 6 forms a part, there is easy synchronization of the period duration during sending with the period duration of a signal previously received via the data bus. The outputs 3, 5 and 9 are also connected to the processing unit 100 to enable the latter to effect particularly simple control of the send-control signal on line 17 in FIG. 3. The arrangements illustrated in FIGS. 3 and 4 or 6 contain logic elements, D-flip-flops and counters which are available for example as integrated circuits. However, these elements can also be implemented by a microprocessor which can assume the role of the transmitter for control of the inverting amplifier 18 in FIG. 3 and the role of the receiver as in the arrangements in FIG. 4 or 6. This is made particularly simple because a relatively low data transmission speed of, say, a few kHz or even less is assumed. The microprocessor can then also take over the function of the processing unit 100 which results in a very inexpensive implementation. The individual functions are executed by a program which implements the elements described in FIGS. 3 and 4 or 6 in time-division multiplex by the appropriate elements of the microprocessor and which is stored in a memory which is produced together with the microprocessor on a single semiconductor wafer. DESCRIPTION OF SEQUENCE CONTROLS FOR SENDING AND RECEIVING FIG. 7 shows a flow diagram for the programming of a microprocessor when this processor performs the sending and receiving of information in a station whereby it is assumed that from any point a low signal is constantly generated on the data bus in the first sub-period U1 in FIG. 2. The sequence begins at point 10 which is designated A, but which in the strict sense is not a starting point because the sequences illustrated in FIG. 7 are passed through in a continuous repeated cycle. This is followed in block 111 by the enquiry whether the data bus carries a low signal. Instead, an interrupt signal may also be released with the changeover to a low signal on the data bus, in which case block 111 then represents a wait loop and the interrupt signal effects a jump to the output of the wait loop. The changeover to a low signal on the data bus marks the beginning of a new period, and in block 112, which is thereby passed through, the contents of a time counter are transferred to a time register and the time counter is re-set to zero. The time register thus contains a measure of the duration of the preceding period. In the next block 113 the status of a flag is interrogated which decides whether the station is in the send or the receive condition. If the station is in the send condition, the sequence proceeds by the way of the point 115 marked C, and its continuation is explained later. In the state of rest, however, the station is in the receive condition, and the sequence proceeds via the point 114 designated B to the block 116 in which there is a wait until the time counter reaches a value of 3/8T where T is the content of the time register. This point of time lies in the middle of the second sub-period U2, in which the signal status on the data bus indicates whether the bus is free or whether another station is making a transmission. A check is made therefore in block 117 whether the signal is low on the data bus. If this is not the case, a transmission is not being made from any station so that a check can be made in the station under consideration whether a transmission is required, i.e. whether there is data present for transmission. If this is not the case, the sequence proceeds via point 121, which for the sake of clarity is designated A, back to point 110, as a result of which the loop indicated at block 111 is passed through until the signal on the data bus becomes low again, i.e. until a new period begins. Thus the described sequence is repeated for as long as no transmission takes place from any station. If, on the other hand, a data transmission is to be started from the station in question, then after the appropriate interrogation in block 118, block 119 is passed through, at which the flag already mentioned is set. This flag may also be a counter to the contents of which a unit is added in block 119. Then the return takes place in fact via point 120, also designated A, to point 110, and with the beginning of the next period the interrogation is run through again in block 113 in which a check can now be made whether the flag counter has reached a certain value. Depending on this value, a priority can in fact be assigned to the respective station, i.e. in the case of a larger value, several periods must be run through after the end of a previous transmission until the relevant station has finally reached the preset value in the flag counter so that another station with a smaller value can begin earlier with the transmission and can therefore, to begin with, block all other stations. It is assumed first of all, however, that another station has begun a transmission so that, when the interrogation is made in block 117, which takes place therefore in the middle of the second sub-period U2, a low signal is established on the data bus which identifies the data bus as being engaged so that a changeover is then made to block 122 in which the flag counter is set to its initial value, in which case this necessity arises due to the explanation given above. Then the process goes by way of point 123 which is designated D to block 124 in which a check is made as to whether the station concerned, which is passive and is not transmitting, within the framework of a data exchange with the station now transmitting is to actively send data back to the latter, as was described earlier. If this is not the case, i.e. the station under consideration here is receiving only, a changeover is made via the point 125 marked E to the block 126 at which there is a wait until the time counter has reached the value 5/8T, because this is the middle of the part period T2 in which the value of the data bit to be transmitted appears as a signal on the data bus. When this point of time is reached, then this value is transferred in block 127 to a data register or data store, and this is followed by a wait in block 128 until the time counter has reached at least the value 3/4T, at which the signal on the data bus in high. This is followed by a return via the point 129, which is also designated A, to the point 110 to receive the next data bit. If provision is made that during a data exchange the first station to receive can also return data to the sending station, and it has been ascertained in block 124 that the receiving station in question is suitably prepared by the information received, the sequence moves to block 130 in which the value of the data bit to be transmitted is transmitted as a signal along data bus 1 by appropriate driving of amplifier 18 in FIG. 3. In this case the second part period 2, which is allocated to the data transmission, has not yet been reached in fact, but this prevents a false, albeit only a short-time signal transition being created on the data bus on the changeover to this part period 2. Such a signal transition can only arise if the sending station generates a high signal on the data bus or places the outer amplifier in a high-ohmic state so that the station under consideration here can determine the signal on the data bus, but only generate a low signal after the high signal has appeared on the data bus. In each period, in fact, only a negative edge may occur, and this at the beginning of the period. In the next block 131 it is waited until the time counter has reached the value 3/4T while the signal condition on the data bus is maintained. When this point in time is reached, part period T2 is completed, and the last part period T3 now begins, in which a high signal is again generated on the data bus. This is followed by a return via the point 133, which is again designated A, to the point 110 and a wait unitl the beginning of the next period. When a wish to transmit is present in the station under consideration here and when it is ascertained on running through the interrogation in block 113 at the beginning of a new period that the appropriate flag is set or the flag counter has reached the specified value, the changeover takes place from point 115 to block 141 via point 140 which is also indicated by C, by means of which a low potential is generated on the data bus. This takes place in fact at the beginning of the first sub-period U1, during which a low potential is already present on the data bus, but this low signal is maintained by the station under consideration for the purpose of identifying the data bus as engaged even during the second sub-period, so that the situation is reached in the appropriate manner as described previously where no interfering edges occur in the signal on the data bus. Then the transition takes place via point 142 marked F to block 143 where there is a wait until the time counter has reached the value 1/2T, from which point on the transmission of a data bit begins. This is followed in block 144 by the interrogation as to whether another station which has been addressed by the station under consideration is to transmit data back. If in fact a transmission is to take place from the other, addressed station back to the station under consideration, the amplifier connected to the data bus must be made high-ohmic in block 145, so that the signal on the data bus can then only be determined by the other station, and then the transition takes place via point 125, which is designated E, to the already described sequence for the reception of data bits. If it is established in block 144 that no transmission is to be made from the other station to the station under consideration, i.e. the latter is to continue transmitting normally, the changeover is made to block 150 in which a signal corresponding to the data bit to be transmitted is supplied to the data bus. The sequence then proceeds to block 151 where it is checked whether the signal on the data bus corresponds to the signal which is generated in the station under consideration by the data bit just transmitted. It is possible in fact that two or even more stations have begun a transmission exactly simultaneously with the same period. First of all, this fact may not immediately be recognized by the simultaneously transmitting stations because no station can ascertain that the signal on the data bus was made low by a corresponding amplifier in another station as well as by its own amplifier. If, however, in the case of the consecutive transmission of bits, which may comprise, for example, the address of the transmitting station, another station generates a low signal on the data bus, this station can now establish that at least one other station is still transmitting simultaneously, and take itself out of the tramsmitting condition so that disturbances of the signals transmitted by the other stations are avoided. In this way, ultimately only one transmitting station remains which transmits a low signal most frequently during the second part period T2 during which the data are transmitted. The subordinated station under consideration here must now pass over into the receiving condition, however, because it is possible that the transmitting station which finally remains will address the station under consideration. For this reason, if it is established in block 151 that the signal on the data bus does not correspond to its own transmitted signal, block 152 in which the flag or flag counter for the send condition is re-set to the initial position is run through, as the result of which the station quits the send condition, and the subsequent operation passes via point 125 once again into the receiving branch from blocks 126 and 128. If, however, it is established in block 151 first of all that the signal on the data bus corresponds to the tansmitted data bit, a check is made in block 153 whether the time counter has reached the value 3/4T, and as long as this is not yet the case, a return is made to block 151 and in this way a check is made throughout the entire second part period T2 whether the data signal on the data bus corresponds to the transmitted signal. When ultimately the end of the second part period T2 is reached, the operation switches to block 154 which generates the high signal on the data bus during the third part period T3, and in the following block 155 a check is made whether the data transmission has ended, i.e. whether all the data to be sent has been transmitted. As long as this is not the case, the procedure passes via point 157, which again is designated A, on to point 110 where the beginning of the next total period is awaited. If, however, the transmission has been completed, block 156, by means of which the flag of flag counter is set to the initial state, is run through, and the send condition of the station under consideration is terminated. The further sequence then also proceeds via point 157 to point 110. In this way all possible conditions of the station are taken into consideration. FIG. 8 shows variations of the sequence compared with that in FIG. 7, if it is assumed that no special clock generator which generates the individual periods or the signal transition at the beginning of each period, is connected to the data bus, but each station which has transmitted data generates the signal for the periods susequently, i.e. the low signal during the first sub-period U1, until such time as another station begins to transmit and, in its turn, generates the signals for fixing the periods. Only when the installation is switched in from the individual stations connectd together by the data bus does one of the stations have to take over the generation of the signals for fixing the periods without a previous transmitting operation. This can be easily achieved as follows; in this one station the re-set signal which is normally generated during switching on has a flag, which will be explainded later, and fills the time register with a pre-set value. It is expedient then for this station at least to have a time control system (not described in any further detail) which responds when due to a fault or disturbance the generation of the signals for fixing the periods fails, and then initiates the operation as in the case of switching on of the installation. In this case, the point corresponding to point 110 in FIG. 7 is point 170 also designated A. First of all, the sequence passes through block 171 in which, as with block 111 in FIG. 7, a check is made whether the signal on the data bus has become low. If this is not the case, then block 172, however, is run through here; in this block the condition of a second flag is interrogated which is set if this station is to generate the signal transition at the beginning of each period. The setting and canceling of this flag is explained later. When this flag is in a state of rest, the signal transition at the beginning of each period is generated therefore by another station, and the system reverts to block 171, and this sequence repeats itself until the signal transition at the beginning of the next period appears. If, however, it is ascertained in block 172 that the second flag is not in a state of rest, i.e. the station under consideration here must generate the signal transition, the operation swtiches to block 173 in which it is checked whether the time counter has reached the value T stored in the time register. As long as this is not the case, the chain of blocks 171 to 173 will be run through. Finally it is established by interrogation in block 173 that the time counter has reached the value in the time register, and then the operation is also switched to block 175 in which case the transmission of the contents of the time counter to the time register is not in fact necessary, but simply the re-setting of the time counter; however, for reasons of simplicity and clarity this block is also used here. Then, a check is made in block 176, in the same way as in block 113, as to whether the first flag or flag counter contains its pre-set value and, if it does, further procedure takes place via the point 177, designated C, as will be explained later. If, however, the send condition has not yet been assumed, operation switches from block 176 to block 178, where it is checked whether the second flag is in the rest condition. If it is, i.e. the station under consideration is not to generate a signal transition at the beginning of each period, the operation is switched via point 179, which is designated B, to the correspondingly designated point in FIG. 4. If, however, the second flag is set, the switch is made from block 178 to block 180 which has the effect that a low signal is generated on the data bus. For all stations this is the beginning of a new transmission period. In block 181 there is a wait until the time counter has reached the 1/4T value, i.e. the end of the first sub-period is reached, and then in block 182 the amplifier connected to the data bus is made high-ohmic again so that in the normal situation the data bus again carries a high signal. Then, the switchover is also made via point 179 to point 114 in FIG. 7. If it is now established there in block 117 that the data bus carries a low signal, this is the sign that another station has begun to transmit and generates the "bus occupied" signal in the second sub-period, and thus in block 122 the second flag is set into the rest condition, in addition to the first flag or flag counter which, of course, is generally already in the rest condition. Otherewise the remainder of the procedure is as described with the aid of FIG. 7. If it is established in block 176 by interrogation that the first flag or flag counter has attained its pre-set value, the operation switches via point 177 designated by C to point 189 also designated by C and then block 191, in which a low signal is brought to the data bus, is run through in the same way as block 141 in FIG. 7. A check is made in block 191 to ascertain whether the content of the time register is greater than a minimum value. It must be remembered in fact that a station which begins to transmit performs this with a value of the period length which has been taken over from the last station to transmit before it, in which case the fraction of an internal clock pulse period at the end each time of a transmission period disappears so that with every reversal the durations of the transmission periods become somewhat shorter. If, therefore, the content of the time register falls below a minimum value defined in the station concerned, then in block 192 this minimum value is written instead into the time register. This is followed, irrespective of the value in the time register, by block 193 in which the second flag is set, and the operation switches via point 194 designated F to the similarly designated point 142 in FIG. 7 and the sequence illustrated and described there takes place. FIG. 9 shows an example of an operation when during transmission pauses during which no station transmits an information bit, no signal transitions are generated either on the data bus. After point 200, which is designated A and which corresponds to point 110 in FIG. 7, the operation passes through block 201, in which it is again checked whether the signal on the data bus has become low. As long as this is not the case, the operation then switches to block 202 in which it is checked whether the time counter has attained a value which is a specified fraction above the value stored in the time register. If, in fact, the station under consideration here was last receiving, and the transmitting station has completed the transmission, this is recognizable from the fact that after expiry of the last period length, whose value is stored in the time register, no transition of the signal on the data bus to a low value occurs. As long as this is not the case, the loop formed from the two locks 201 and 202 is run through repeatedly. If a signal transition occurs on the data bus, the operation switches from block 201 to block 212 in which the value of the time counter reached at this momemt is transferred into the time register and the time counter is re-set. Then the operation switches via the point 213 designated D to the similarly designated point 123 in FIG. 7. The corresponding change is made from the end points in FIG. 7 134 or 129 to the point 200. If, however, at the end of a transmission by another station it is established in block 202 that the time counter has exceeded the duration of the last preceding period by a specified fraction, with which a priority of the station in question can be set by means of this fraction, a receive flag which indicates the current receive status is re-set in block 203 to the initial value. Then a check is made in lock 204 as to whether the signal on the data bus has become low, i.e. whether another station has begun to transmit, and if this is not the case, a check is made in block 205 whether data for transmission is present in the station under consideration here. If this is the case, the procedure switches via the point 206 designated P to the correspondingly designated point 220, with which is linked a transmission sequence, to be explained later. If no data for transmission is present, the process reverts to block 204, and this loop of blocks 204 and 205 is run through until either another station begins to transmit or data for transmission appear in this station. When another station begins to transmit, a signal transition on the data bus to a low signal is initiated, and the operation switches from block 204 to block 207 in which it is checked whether the receive flag is in the rest condition. As described earlier, in the initial period at the beginning of a transmission no data bit is transmitted, but the first period serves merely for communication of the period length in which transmission will be made subsequently. Initially, therefore, the receive flag is still in the rest condition so that the procedure switches to block 208 in which the time counter is reset to the initial value. The operation then switches via the point 209 designated 209 to block 210 in which the receive flag is set and a send flag, to be explained later, is cancelled, and it is then checked in block 211 whether the signal on the data bus is again high, i.e. whether the first part period has elapsed. Then the operation moves to block 204 where the beginning of the next period is awaited. With the beginning of the next period it is established in block 207 that the receive flag is no longer in the rest condition, and the operation switches to block 212 in which the value of the time counter is transferred to the time register which thus contains the length of the first period, and the time counter is re-set to zero. The operation then swtiches, as described, via point 213 to point 123 in FIG. 7 where the transmitted data bit is received or, if the transmission direction has been reversed in the meantime, a data bit is transmitted. In the following periods the operation switches via point 200 and block 201 directly to block 212 until the transmission begun by another station is completed. If a data transmission is to be begun in the station under consideration here, then the operation switches, as mentioned, from point 206 to point 220, and block 221 in which the time counter is re-set to the initial value is run through. In block 222 a low signal is generated on the data bus, and in block 223 there is a wait until the time counter has reached a value 1/2T p , where T p is a value fixed in this station which determines the period length of this station during transmission. In block 224 it is checked whether a send flag is set. If this is not the case, the period concerned, therefore, is the first period of the send operation, and the procedure moves to block 225 in which the send flag is set, and then in block 226 a high potential is generated on the data bus. In this first period of a transmission operation, therefore, no data is transmitted, but the period length is merely communicated to the other stations. After block 226 it is checked in block 227 whether the signal on the data bus is in fact high to take account of the situation where two or more stations have begun to transmit simultaneously, in which case a station with longer period length has the result that a switch is made via the point 228 designated V to the correspondingly marked point 209, which is followed by the sequence for the reception of data signals. If, however, the signal on the data bus is in fact high, the operation switches to block 229 in which it is checked whether the time counter has reached the specified value T p , i.e. a transmission period has been completed. As long as this is not the case, the loop comprising blocks 227 and 229 is run through repeatedly. At the end of the period, the sequence switches to block 230 in which it is checked whether the transmission of data has ended. If this is not the case, the operation switches via the point 231 designated P to point 220. and a further period with a transmission of a data character follows. In this second subsequent period it is ascertained in block 224 that the send flag is set, and it is checked in block 240 whether a transmission is to take place from an addressed receiving station to this transmitting station under consideration here. If this is the case, then here in block 241 the amplifier connected to the data bus is made high-ohmic, in the same way as indicated in FIG. 7 for clock 144. In block 242 there is a wait until the time counter has reached the value 5/8T p , i.e. the middle of the part period is reached at which the signal corresponds to the value of the transmitted data bit, and when this point in time is reached, the signal is taken from the data bus and stored in block 243, and there is a waiting time in block 244 until the time counter has reached the value T p , i.e. a further period has ended. Then the procedure reverts again via the point 245 designated P to point 220. If, however, data bits are to be transmitted quite normally by the station under consideration here, the operation switches from block 240 to block 246 in which a signal corresponding to the data bit for transmission is brought to the data bus. It is checked in block 247 whether the signal on the data bus corresponds in fact to the signal value on the data bus as determined by the data bit to be transmitted, to allow for the situation where anothr station with exactly the same period length has begun to transmit, as has already been explained with the aid of block 151 in FIG. 7. If this is the case, the procedure is switched via the point 248 designated 248 to the correspondingly designated point 209 and the sequence for the repeated reception of data bits is run through. If, however, the signal generated by this station coincides with the actual signal on the data bus, it is checked in block 249 whether the time counter has reached the value 3/4T p , i.e. the end of the second part period T2. As long as this point in time has not been reached, the loop comprising blocks 247 and 249 is run through repeatedly. If the time counter has reached the value 3/4T p , the operation switches to block 226, and the subsequent operation has already been described essentially. Only when the last data bit has been transmitted and it is established in block 230 that the transmission has ended, does the operation not revert via point 231 to point 220, but continues to block 232, in which the send flag is re-set, which means that the station has thus abandoned the transmit condition again. The operation then reverts again to block 204, and the wait loop comprising blocks 204 and 205 for the rest condition is run through until either another station begins to transmit or there is data for transmission present again in the station under consideration here. The operating sequences described here are given only as examples and can also be structured in other ways. The described operating sequences, in particular, do not contain descriptions of measures for the preparation of data for transmission or the processing of data received, nor especially the measures required for the control of the data when the station has begun to transmit, but has been placed in the receive condition by another station which has begun to transmit simultaneously, since such measures do not form part of the actual operation of the transmission of data to which the invention relates. These measures can be carried out advantageously by the same microprocessor which controls the transmission operations described, during the specified waiting operations for example. As the foregoing description shows, the data bus is a so-called "single-wire logic bus", i.e. for the moment only a single signal is transmitted which means that in the case of an electrical connection a second wire is required for a reference potential in addition to the signal wire. In the case of a glass fiber connection, however, only one glass fiber is in fact needed. For the rest, however, a special connection is not always absolutely essential, but the signals to be transmitted on the data bus can also be transmitted as more or less undirected sound or light signals or electromagnetic waves of another frequency through the air or in the latter case through free space. In this situation the signal transition from one medium to another, for example from electrical signals to light signals, can be made directly without any special processing. However, supplying individual stations with electrical energy from one or more other stations is feasible in practice only when using electrical lines as the data bus. In order to lengthen the time during which the stations are supplied with energy via the data bus, i.e. in which the signal on the data bus is high, another ratio of the individual part periods or sub-periods to one another may then also be chosen; in particular, the third part period can be lengthened considerably. If, for example, the duration of the third part period takes up five eighths of the total period and the two sub-periods and the second part period each amount to only about an eighth of the total period length, the described shift of the counter reading in the arrangements in FIGS. 4 and 6, for example, must involve an extra digit.

For data transmission via a data bus in the form of a single-wire bus, to which several stations are connected in parallel, data bits are transmitted singly in a periodic sequence of signals, whereby each period has at least one section in which the transmitted signal indicates the occupancy of the data bus, a further section in which the transmitted signal indicates the value of the data bit, and a section without data, preferably with high potential in the case of an electric data bus, to which the data generated by the individual stations is linked by an OR function. The durations of the individual sections have fixed periods with respect to one another, and from the signal transfer at the beginning of every two successive periods the duration of the period in each station is determined and from the the position of the individual sections is determined in which the signal is sampled on the data bus and the value of the transmitted data bit is determined. In a preferred embodiment, at the beginning of each period a signal transfer is created on the data bus permanently, outside of a data transmission, so that a first section of the period represents a permanent clock pulse on the data bus which synchronizes all the stations. For the signal which indicates the occupancy of the data bus a section is reserved after this which is then followed again by the time period for the data bit. This makes it possible to achieve a data transmission between stations the internal clocks of which exhibit considerable differences, and yet multimaster operation is still possible.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation of U.S. application Ser. No. 14/646,330, filed May 20, 2015, which is a National Stage filing of International Application No. PCT/JP2013/081331 filed Nov. 14, 2013, which claims priority from Japanese Patent Application No. 2012-256772 filed Nov. 22, 2012, each of which is hereby incorporated by reference herein in their entirety. TECHNICAL FIELD [0002] The present invention relates to an image capturing apparatus, an image capturing system, a control method of the image capturing apparatus, and a computer readable storage medium. BACKGROUND ART [0003] Conventionally, an image capturing apparatus for transmitting a captured image to a receiving apparatus includes commands for allowing an external apparatus to change the settings of the image capturing apparatus and designate the start of image distribution. Known examples of these commands are those defined by standards formulated by the ONVIF (Open Network Video Interface Forum). [0004] In the ONVIF specifications (http://www.onvif.org/specs/DocMap.html), commands formulated by the ONVIF are described. [0005] The above-described commands include, for example, a command for changing, from an external apparatus, the resolution of image data to be generated by an image capturing unit of the image capturing apparatus. The above-described commands also include a command for changing the resolution of a distribution image to be distributed to an external apparatus when the distribution image is generated by encoding image data generated by the image capturing unit. For example, in the ONVIF standards, a SetVideoSourceMode command is defined as the former command, and a SetVideoEncoderConfiguration command is defined as the latter command. [0006] Furthermore, in addition to the ONVIF standards, Japanese Patent Laid-Open No. 2005-323007 has disclosed an image capturing apparatus including a control unit for controlling the expansion and compression of a captured image. [0007] Unfortunately, there is a problem that if only one of the resolution of image data to be generated by the image capturing unit and the resolution of a distribution image to be generated by a compression encoding unit is changed, mismatching occurs in a combination of the two resolutions and this makes the generation of the distribution image impossible in some cases. Also, in a case like this, it is necessary to transmit a command for correctly changing the other resolution from an external apparatus to the image capturing apparatus, in order to cancel the mismatching and correctly generate the distribution image. This complicates the user's operation. [0008] Assume that the output resolution of the image capturing unit is 1,600×1,200 pixels (UXGA), and the output resolution of the compression encoding unit is 1,280×1,024 pixels (SXGA). In this case, if the output resolution of the image capturing unit is changed to 1,024×768 (XGA), the compression encoding unit in which a higher output resolution is set may become unable to generate any distribution image. Assume also that the output resolution of the image capturing unit is 1,600×1,200 pixels (resolution aspect ratio=4:3), and the output resolution of the compression encoding unit is 1,280×1,024 pixels (resolution aspect ratio=4:3). In this case, if the output resolution of the image capturing unit is changed to 1,920×1,080 (full HD, resolution aspect ratio=16:9), the compression encoding unit in which a different resolution aspect ratio is set may become unable to generate any distribution image. [0009] If this is the case, before obtaining a video stream from the image capturing unit, the user must change the output resolution of the compression encoding unit to a resolution, such as 1,024×768 (XGA) or 1,920×1,080 (resolution aspect ratio=16:9), which matches the output resolution of the image capturing unit, and this complicates the operation. SUMMARY OF INVENTION [0010] The present invention provides an image capturing technique that prevents the occurrence of mismatching in a combination of the resolution of image data to be generated by an image capturing unit and the resolution of a distribution image to be generated by a compression encoding unit, even when only one resolution is changed. [0011] According to one aspect of the present invention, there is provided an image capturing apparatus comprising: an encoding unit configured to perform encoding processing on an image output from an image capturing unit for obtaining an image; a communication unit configured to receive designation of a resolution of the encoding unit from an information processing apparatus; an obtaining unit configured to obtain a resolution which is associated with the resolution set for the image capturing unit, and is settable for the encoding unit; a determination unit configured to determine whether the designated resolution is the resolution obtained by the obtaining unit and settable for the encoding unit; and a transmission unit configured to transmit an error response to the information processing apparatus via the communication unit, if the determination unit determines that the designated resolution is not the resolution obtained by the obtaining unit and settable for the encoding unit. [0012] According to another aspect of the present invention, there is provided a control method of an image capturing apparatus including an encoding unit configured to perform encoding processing on an image output from an image capturing unit for obtaining an image, comprising: a first communication step of receiving designation of a resolution of the encoding unit from an information processing apparatus; an obtaining step of obtaining a resolution which is associated with the resolution set for the image capturing unit, and is settable for the encoding unit; a determination step of determining whether the designated resolution is the resolution obtained in the obtaining step and settable for the encoding unit; and a transmission step of transmitting an error response to the information processing apparatus, if it is determined in the determination step that the designated resolution is not the resolution obtained in the obtaining step and settable for the encoding unit. [0013] According to still another aspect of the present invention, there is provided a computer readable storage medium containing computer-executable instructions that control an image capturing apparatus including an encoding unit configured to perform encoding processing on an image output from an image capturing unit for obtaining an image, the medium comprising: computer-executable instructions that receive designation of a resolution of the encoding unit from an information processing apparatus; computer-executable instructions that obtain a resolution which is associated with the resolution set for the image capturing unit, and is settable for the encoding unit; computer-executable instructions that determine whether the designated resolution is the obtained resolution settable for the encoding unit; and computer-executable instructions that transmit an error response to the information processing apparatus, if it is determined that the designated resolution is not the obtained resolution settable for the encoding unit. [0014] According to yet another aspect of the present invention, there is provided an image capturing system comprising an image capturing apparatus including an encoding unit configured to encode an image output from an image capturing unit for obtaining an image, and an information processing apparatus connected to the image capturing apparatus across a network, wherein the information processing apparatus comprises a generation unit configured to generate designation of a resolution of the encoding unit, and the image capturing apparatus comprises: a communication unit configured to receive the designation of the resolution of the encoding unit from the information processing apparatus; an obtaining unit configured to obtain a resolution which is associated with the resolution set for the image capturing unit, and is settable for the encoding unit; a determination unit configured to determine whether the designated resolution is the resolution obtained by the obtaining unit and settable for the encoding unit; and a transmission unit configured to transmit an error response to the information processing apparatus via the communication unit, if the determination unit determines that the designated resolution is not the resolution obtained by the obtaining unit and settable for the encoding unit. [0015] Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). BRIEF DESCRIPTION OF DRAWINGS [0016] FIGS. 1A and 1B are views showing examples of the arrangements of an image capturing apparatus and image capturing system; [0017] FIG. 2 is a view showing an example of the internal arrangement of the image capturing apparatus; [0018] FIG. 3 is a view showing an example of the structure of parameters held by the image capturing apparatus; [0019] FIG. 4 is a view showing an example of a table storing information for matching the settings of an image capturing unit of the image capturing apparatus with the settings of a compression encoding unit; [0020] FIG. 5A is a view showing an example of a command sequence from the start of setting of the image capturing apparatus to video distribution; [0021] FIG. 5B is a view showing an example of a command sequence when changing the output resolution of the image capturing unit of the image capturing apparatus; [0022] FIG. 5C is a view showing an example of a command sequence when changing the output resolution of the compression encoding unit of the image capturing apparatus; [0023] FIG. 6A is a view for explaining a procedure when the image capturing apparatus changes the settings of the image capturing unit; [0024] FIG. 6B is a view for explaining a procedure when the image capturing apparatus transmits a selectable set value to an information processing apparatus; [0025] FIG. 6C is a view for explaining a procedure when the image capturing apparatus changes the settings of the compression encoding unit; [0026] FIG. 6D is a view for explaining a procedure when the image capturing apparatus transmits a selectable set value to the information processing apparatus; [0027] FIG. 6E is a view for explaining a procedure when the image capturing apparatus changes the settings of the compression encoding unit; [0028] FIG. 7A is a view showing an example of a setting screen of a client apparatus; and [0029] FIG. 7B is a view showing another example of the setting screen of the client apparatus. DESCRIPTION OF EMBODIMENTS [0030] Exemplary embodiments of the present invention will be explained in detail below with reference to the accompanying drawings. However, constituent elements described in these embodiments are merely examples, and the technical scope of the present invention is determined by the scope of the appended claims, and is not limited by the following individual embodiments. First Embodiment [0031] FIG. 1A is a view showing an example of a monitoring camera 1000 as an image capturing apparatus according to the embodiment of the present invention. A mechanism 1101 is a mechanism for changing the direction of a lens in a panning direction, a mechanism 1102 is a mechanism for changing the lens direction in a tilting direction, and a mechanism 1103 is a mechanism for changing zooming. [0032] FIG. 1B is a view showing an example of the configuration of an image capturing system including the monitoring camera 1000 . A client apparatus 2000 (an information processing apparatus) as an external apparatus is connected to the monitoring camera 1000 across a network 1500 so as to be able to communicate with the monitoring camera 1000 . The client apparatus 2000 transmits various commands such as a command for changing image capturing parameters (to be described later), a command for driving a platform, and a command for starting video streaming to the monitoring camera 1000 . The monitoring camera 1000 transmits responses to these commands and video streaming to the client apparatus 2000 . [0033] FIG. 2 is a view showing an example of the internal arrangement of the monitoring camera 1000 (the image capturing apparatus). Referring to FIG. 2 , a control unit 1001 is a CPU or the like, and controls the whole monitoring camera 1000 . A storage unit 1002 is used as various data storage areas such as a storage area for programs to be mainly executed by the control unit 1001 , a work area to be used while the programs are executed, and a storage area for image data generated by an image capturing unit 1003 (to be described below). [0034] The image capturing unit 1003 converts an analog signal obtained by capturing an object image into digital data, and outputs the data as a captured image (image data) to the storage unit 1002 . The resolution and frame rate of the image data output from the image capturing unit 1003 can be changed by a SetVideoSourceMode command (to be described later). [0035] A compression encoding unit 1004 generates image data by performing compression encoding processing on the captured image output from the image capturing 1003 based on a format such as Motion JPEG or H.264, and outputs the generated image data to the storage unit 1002 . The types of the resolution (distribution resolution) of the image data output from the compression encoding unit 1004 have a dependency relationship as shown in FIG. 4 (to be described later) with each mode of the image capturing unit 1003 . [0036] A communication unit 1005 receives each control command from the external apparatus (client apparatus 2000 ). Also, the communication unit 1005 transmits a response to each control command to the external apparatus (client apparatus 2000 ). Furthermore, the communication unit 1005 receives first designation for setting the resolution of the image capturing unit 1003 , or second designation for setting the resolution of the compression encoding unit 1004 . When the setting of one resolution is to be changed to a different resolution setting by the first or second designation, the control unit 1001 changes the setting of the other resolution to a resolution matching the setting of one resolution. This resolution changing process will be explained in detail later with reference to FIGS. 6A, 6C, and 6E . [0037] An image capturing control unit 1006 controls the tilting mechanism 1101 , panning mechanism 1102 , and zooming mechanism 1103 in response to the values of a panning angle, tilting angle, and zooming magnification input from the control unit 1001 . Also, the image capturing control unit 1006 provides the current panning angle value, tilting angle value, and zooming magnification value of the monitoring camera 1000 , in accordance with an inquiry from the control unit 1001 . The internal arrangement of the monitoring camera 1000 has been explained above with reference to FIG. 2 . However, the processing blocks shown in FIG. 2 are exemplary blocks, so the arrangement of the image capturing apparatus according to the embodiment of the present invention is not limited to the processing blocks shown in FIG. 2 . For example, it is also possible to use a voice input unit in addition to the processing blocks shown in FIG. 2 , or exclude the image capturing control unit therefrom, that is, various modifications and changes can be made. [0038] Next, the names and contents of commands, parameters, and the like used in this embodiment will be explained. FIG. 3 shows the structure of parameters held by the monitoring camera 1000 (the image capturing apparatus) in this embodiment. A MediaProfile 6100 is a parameter set for storing various setting items of the monitoring camera by associating them with each other. The MediaProfile 6100 holds links to various setting items including a ProfileToken as the ID (identification information) of the MediaProfile 6100 , a VideoSourceConfiguration 6102 , a VideoEncoderConfiguration 6103 , a PTZConfiguration 6104 , and a voice encoder. [0039] A VideoSource 6101 is a set of parameters indicating the performance of the image capturing unit 1003 of the monitoring camera. The VideoSource 6101 includes a VideoSourceToken as the ID of the VideoSource 6101 , and Resolution indicating the resolution of image data which the image capturing unit 1003 can output. The VideoSource 6101 can switch to a plurality of other VideoSourceModes (operation modes) that support different Resolutions, in accordance with a SetVideoSourceMode command (to be described later). [0040] The VideoSourceConfiguration 6102 is a set of parameters for associating the VideoSource 6101 of the monitoring camera 1000 with the MediaProfile 6100 . The VideoSourceConfiguration 6102 includes Bounds that designate a portion to be cut out, as a distribution image, from image data output from the VideoSource 6101 . [0041] The VideoEncoderConfiguration 6103 is a set of parameters for associating the settings of an encoder (the compression encoding unit 1004 ) pertaining to image data compression encoding with the MediaProfile 6100 . The compression encoding unit 1004 of the monitoring camera 1000 compression-encodes image data output based on the contents of the VideoSource 6101 and VideoSourceConfiguration 6102 . The compression encoding unit 1004 of the monitoring camera 1000 compression-encodes image data output from the image capturing unit 1003 , in accordance with a parameter such as the compression encoding scheme (for example, JPEG or H.264) set in VideoEncoderConfiguration 6103 , the frame rate, or resolution. The monitoring camera 1000 distributes the compression-encoded image data to the client apparatus 2000 via the communication unit 1005 . [0042] The VideoEncoderConfiguration 6103 includes a VideoEncoderConfigurationToken as the ID (identification information) of the VideoEncoderConfiguration 6103 . The VideoEncoderConfiguration 6103 also includes Encoding for designating a compression encoding scheme, a Resolution for designating the resolution of an output image, and a Quality for designating the compression encoding quality. Furthermore, the VideoEncoderConfiguration 6103 includes FramerateLimit for designating the maximum frame rate of an output image, and BitrateLimit for designating the maximum bit rate. [0043] The PTZConfiguration 6104 is a set of parameters for associating the settings of the panning mechanism 1101 , tilting mechanism 1102 , and zooming mechanism 1103 of the monitoring camera 1000 with the MediaProfile 6100 . The PTZConfiguration 6104 contains information pertaining to a coordinate system for expressing actual panning/tilting angle values and an actual zooming magnification value in the panning mechanism, tilting mechanism, and zooming mechanism. [0044] A table shown in FIG. 4 contains information of a plurality of choices for matching the settings of the image capturing unit 1003 with those of the compression encoding unit 1004 . This table shown in FIG. 4 indicates the setting contents of VideoSourceModes supported by the monitoring camera 1000 , and the setting contents of the VideoEncoderConfigurations 6103 matching the VideoSourceModes. The table shown in FIG. 4 is prestored in the storage unit 1002 of the monitoring camera 1000 , and referred to by the control unit 1001 any time. The table shown in FIG. 4 need not always be prestored in the storage unit 1002 , and may also obtain necessary data by referring to a database of the external apparatus via the communication unit 1005 . [0045] A VideoSourceMode 4000 indicates the management number of a VideoSourceMode to be used in internal processing by the monitoring camera 1000 . In this embodiment, the monitoring camera 1000 supports three VideoSourceModes S 1 , S 2 , and S 3 . [0046] A Resolution 4001 is the parameter value of the Resolution of each VideoSourceMode (S 1 , S 2 , or S 3 ), and indicates the resolution of image data generated by the image capturing unit 1003 . A Framerate 4002 is the parameter value of the frame rate of each VideoSourceMode, and indicates the frame rate of image data to be generated by the image capturing unit 1003 . [0047] Items from Encoding 4003 to FramerateLimit 4006 are choices of the parameters of the VideoEncoderConfiguration 6103 which match when the VideoSource 6101 is each VideoSourceMode. The Encoding 4003 indicates a choice of a compression encoding scheme in the VideoEncoderConfiguration, which matches the VideoSourceMode. The Resolution Choice 4004 indicates the management number of the resolution of the compression-encoded output image in the VideoEncoderConfiguration, which is to be used in the internal processing of the monitoring camera 1000 . In this embodiment, the monitoring camera 1000 supports four resolutions E 1 to E 4 . [0048] The Resolution 4005 is the parameter value of the resolution of the VideoEncoderConfiguration, which matches each VideoSourceMode. This set value determines the resolution of a distribution image to be output from the compression encoding unit 1004 . The FramerateLimit 4006 (the frame rate limit) indicates the maximum value of the frame rate in the VideoEncoderConfiguration, which matches each VideoSourceMode. [0049] FIG. 5A shows a command sequence from setting start to video distribution between the monitoring camera 1000 and client apparatus 2000 . Transaction means a pair of a command to be transmitted from the client apparatus 2000 to the monitoring camera 1000 , and a response to be returned from the monitoring camera 1000 to the client apparatus 2000 . [0050] A transaction 7100 is the transaction of a GetVideoSourceConfigurations command. By this command, the client apparatus 2000 obtains a list of the VideoSourceConfigurations 6102 held by the monitoring camera 1000 . [0051] A transaction 7101 is the transaction of a GetVideoEncoderConfigurations command. By this command, the client apparatus 2000 obtains a list of the VideoEncoderConfigurations 6103 held by the monitoring camera 1000 . [0052] A transaction 7102 is the transaction of a GetConfigurations command. By this command, the client apparatus 2000 obtains a list of the PTZConfigurations 6104 held by the monitoring camera 1000 . [0053] A transaction 7103 is the transaction of a CreateProfile command. By this command, the client apparatus 2000 causes the monitoring camera 1000 to form a new MediaProfile 6100 , and obtains its Profiletoken. [0054] A transaction 7104 is the transaction of an AddVideoSourceConfiguration command, and a transaction 7105 is the transaction of an AddVideoEncoderConfiguration command. A transaction 7108 is each transaction of an AddPTZConfiguration command. By designating the ID in these commands, the client apparatus 2000 can associate a desired VideoSourceConfiguration, desired VideoEncoderConfiguration, and desired PTZConfiguration with the designated MediaProfile. [0055] A transaction 7106 is the transaction of a GetVideoEncoderConfigurationOptions command. By this command, the client apparatus 2000 obtains the choices or set value range of each parameter acceptable by the monitoring camera 1000 , in the VideoEncoderConfiguration designated by the ID. [0056] A transaction 7107 is the transaction of a SetVideoEncoderConfiguration command. By this command, the client apparatus 2000 sets each parameter of the VideoEncoderConfiguration 6103 . [0057] A transaction 7109 is the transaction of a GetStreamUri command. By this command, the client apparatus 2000 obtains an address (URI) with which the monitoring camera 1000 obtains a distribution stream based on the settings of the designated MediaProfile. [0058] A transaction 7110 is the transaction of a Describe command. By executing this command by using the URI obtained in the transaction 7109 , the client apparatus 2000 requests and obtains information of contents to be distributed by a stream by the monitoring camera 1000 . [0059] A transaction 7111 is the transaction of a Setup command. By executing this command by using the URI obtained in the transaction 7109 , the client apparatus 2000 and monitoring camera 1000 share a stream transmission method including the session number. [0060] A transaction 7112 is the transaction of a Play command. By executing this command by using the session number obtained in the transaction 7111 , the client apparatus 2000 requests the monitoring camera 1000 to start streaming. [0061] In a distribution stream 7113 , the monitoring camera 1000 distributes a stream requested to be started in the transaction 7112 by the transmission method shared in the transaction 7111 . [0062] A transaction 7114 is the transaction of a Teardown command. By executing this command by using the session number obtained in the transaction 7111 , the client apparatus 2000 requests the monitoring camera 1000 to stop the stream. [0063] FIG. 5B shows a command sequence when the setting change of the image capturing unit 1003 , which includes changing of the output resolution, is performed between the monitoring camera 1000 and client apparatus 2000 . [0064] A transaction 7200 is the transaction of a GetVideoSourceMode command. The GetVideoSourceMode command is a command for returning a list of VideoSourceModes supported by the VideoSource 6101 having the ID designated by the client apparatus 2000 . When receiving the GetVideoSourceMode command, the control unit 1001 of the monitoring camera 1000 obtains the parameters of the VideoSourceModes S 1 to S 3 saved in the storage unit 1002 and shown in FIG. 4 , and returns the parameters to the client apparatus 2000 via the communication unit 1005 . [0065] A transaction 7201 is the transaction of a SetVideoSourceMode command. The SetVideoSourceMode command is a command for designating changing of the VideoSourceMode of the VideoSource 6101 designated by the client apparatus 2000 . Transactions 7109 to 7112 and a distribution stream 7113 are the same as those shown in FIG. 5A . [0066] FIG. 5C shows a typical command sequence when changing the output resolution of the compression encoding unit 1004 between the monitoring camera 1000 and client apparatus 2000 . [0067] Transactions 7101 , 7106 , 7107 , and 7109 to 7113 are the same as those of the command sequence shown in FIG. 5A . [0068] FIG. 6A is a view showing processing when the monitoring camera 1000 has received the above-described SetVideoSourceMode command (transaction 7201 ) from the client apparatus 2000 . In step S 1000 , the control unit 1001 stops a video stream currently being distributed via the communication unit 1005 . [0069] In step S 1001 , the control unit 1001 determines whether the input VideoSourceMode is S 1 , S 2 , or S 3 , obtains the set value of the corresponding VideoSourceMode, and sets the set value in the image capturing unit 1003 . [0070] In step S 1002 , the control unit 1001 determines whether the set value of the resolution (Resolution) of each VideoEncoderConfiguration stored in the storage unit 1002 is E 1 , E 2 , E 3 , or E 4 . The control unit 1001 sets, in the VideoEncoderConfiguration, the resolution matching the VideoSourceMode determined in step S 1001 and having the same management number. That is, if the resolution of the VideoEncoderConfiguration is 1,920×1,080=E 2 before command reception when the VideoSourceMode of the VideoSource 6101 is changed from S 1 to S 2 , the resolution is changed to 2,048×1,536 as the resolution of E 2 matching S 2 by the reception of this command. [0071] In step S 1003 , the control unit 1001 sets an Enable flag corresponding to the VideoSourceMode determined in step S 1001 to “True”, and sets enable flags corresponding to other VideoSourceModes to “False”. [0072] In step S 1004 , the control unit 1001 transmits a normal response to the client apparatus 2000 . [0073] FIG. 6B shows processing when the monitoring camera 1000 has received a GetVideoEncoderConfigurationOption command (the transaction 7106 ) from the client apparatus 2000 . In step S 1100 , the control unit 1001 obtains the set value of the VideoSourceMode currently set in the VideoSource 6101 , and determines whether the set value is S 1 , S 2 , or S 3 . [0074] In steps S 1101 , S 1102 , and S 1103 , the control unit 1001 refers to the table shown in FIG. 4 which is stored in the storage unit 1002 , and obtains a selectable set value (choice) matching the current VideoSourceMode. The control unit 1001 obtains the choices E 1 to E 4 of the resolution of the VideoEncoderConfiguration, the choices of the Encoding, and the FramerateLimit as the maximum frame rate. For example, when the set value of the current VideoSourceMode is S 3 , the control unit 1001 obtains 800×600 (E 1 ), 640×480 (E 2 ), 320×240 (E 3 ), and 176×144 (E 4 ) as the choices of the Resolution. Also, the control unit 1001 obtains H.264 and MotionJPEG as the choices of the Encoding, and 30 fps as the FramerateLimit. [0075] In step S 1104 , the control unit 1001 obtains the choices and setting range of the VideoEncoderConfiguration independent of the current VideoSourceMode from the storage unit 1002 . For example, the control unit 1001 obtains 1 to 5 as the settable range of the Quality, and 60 Mbps as the set value of the BitrateLimit. [0076] In step S 1105 , the control unit 1001 transmits a normal response containing the choices and setting ranges obtained in steps S 1101 to S 1104 to the client apparatus 2000 via the communication unit 1005 . [0077] FIG. 6C shows processing when the monitoring camera 1000 has received the above-described SetVideoEncoderConfiguration command (transaction 7107 ) from the client apparatus 2000 . [0078] In steps S 1200 , S 1201 , and S 1202 , the control unit 1001 determines whether the set value input to the received SetVideoEncoderConfiguration matches the current VideoSourceMode. The control unit 1001 refers to the table shown in FIG. 4 which is stored in the storage unit 1002 , and determines whether the Resolution, Encoding, and FramerateLimit input to the received SetVideoEncoderConfiguration match the current VideoSourceMode. If even one parameter does not match, the control unit 1001 advances the process to step S 1210 . In step S 1210 , the control unit 1001 transmits an error response to the client apparatus 2000 via the communication unit 1005 . [0079] On the other hand, in step S 1203 , the control unit 1001 stores the set values of the VideoEncoderConfiguration including the Quality, BitrateLimit, Encoding, FramerateLimit, and Resolution in the storage unit 1002 , and sets them in the compression encoding unit 1004 . [0080] In step S 1204 , the control unit 1001 transmits a normal response to the client apparatus 2000 . [0081] FIG. 7A is a view showing an example of a setting screen of the client apparatus 2000 , in which the VideoSourceMode and VideoEncoderConfiguration of the monitoring camera 1000 according to this embodiment are set. [0082] When the setting screen shown in FIG. 7A is opened, the client apparatus 2000 executes the sequence shown in FIG. 5A , and displays a video stream obtained in the transaction 7113 in a LiveView area 9000 (a display area). [0083] An area 9001 is a VideoSourceMode selection area. The client apparatus 2000 displays, in this area, a list of VideoSourceModes obtained by the transaction 7200 of the GetVideoSourceMode command executed when this setting screen is opened, so that the user can select a mode as indicated by reference numeral 9002 . If a VideoSourceMode different from the current setting is selected in this area, the client apparatus 2000 executes the SetVideoSourceMode command, and changes the VideoSourceMode of the monitoring camera 1000 . In this state, the client apparatus 2000 executes the transactions shown in FIG. 5B , and displays a video stream having the new settings in the LiveView area 9000 (the display area). In addition, the client apparatus 2000 executes the GetVideoEncoderConfigurationOptions command, and updates the choices and setting ranges of the individual parameters of the VideoEncoder in this screen by using the obtained results. Accordingly, the client apparatus 2000 can always provide the user with the choices and setting ranges of the set values of the VideoEncoderConfiguration matching the VideoSourceMode. [0084] Setting screen switching sections 9003 and 9004 are tabs for switching VideoEncoder setting screens for allowing the user to change the set values of the VideoEncoderConfiguration 6103 of the monitoring camera 1000 . The number of tabs is two (the setting screen switching sections 9003 and 9004 ) in this embodiment, but it is also possible to display tabs equal in number to the VideoEncoderConfigurations 6103 obtained by the GetVideoEncoderConfigurations command and supported by the monitoring camera 1000 . [0085] An area 9005 is an area for allowing the user to select the compression encoding scheme of each VideoEncoderConfiguration. The GetVideoEncoderConfigurationOptions command is executed when the setting screen is opened, or when a new VideoSourceMode is selected in the VideoSourceMode selection area. The area 9005 displays the choices of encoding obtained by the GetVideoEncoderConfigurationOptions command. A choice 9006 indicates currently selectable Encoding, and a choice 9007 indicates currently unselectable Encoding. [0086] An area 9008 is a Detail area for allowing the user to select the FramerateLimit, BitrateLimit, and Quality included in the VideoEncoderConfiguration 6103 . The GetVideoEncoderConfigurationOptions command is executed when the setting screen shown in FIG. 7A is opened, or when a new VideoSourceMode is selected in the VideoSourceMode selection area. The contents of the setting ranges obtained by the GetVideoEncoderConfigurationOptions command are reflected in setting ranges 9009 , 9010 , and 9011 . [0087] An area 9012 is an area for selecting the resolution of the VideoEncoderConfiguration 6103 . The GetVideoEncoderConfigurationOptions command is executed when the setting screen shown in FIG. 7A is opened, or when a new VideoSourceMode is selected in the VideoSourceMode selection area. The contents of the choices of the Resolution parameter obtained by the GetVideoEncoderConfigurationOptions command are displayed in a dropdown list 9013 . [0088] When the user presses an apply button 9014 , the client apparatus 2000 transmits the SetVideoEncoderConfiguration command to the monitoring camera 1000 . The parameters selected in the areas 9005 , 9008 , and 9012 are reflected in the compression encoding unit 1004 of the monitoring camera 1000 . [0089] When the VideoSourceMode is changed by the client apparatus 2000 , the monitoring camera 1000 can maintain the contents of choices provided by the setting contents of the VideoEncoderConfiguration and by the VideoEncoderConfigurationOptions command, as contents matching the VideoSourceMode. Accordingly, when obtaining a distribution image after changing the VideoSourceMode, the client apparatus 2000 need not change the setting contents of the VideoEncoderConfiguration to contents matching the VideoSourceMode. That is, even when the resolution of image data to be generated by the image capturing unit 1003 of the monitoring camera 1000 is changed, it is possible to prevent the occurrence of mismatching in various settings including the resolution of a distribution image to be generated by the compression encoding unit 1004 . It is also possible to easily generate a distribution image after the resolution is changed. Second Embodiment [0090] In the first embodiment, the arrangement in which the contents of choices provided by the setting contents of the VideoEncoderConfiguration and by the VideoEncoderConfigurationOptions command are changed to contents matching the VideoSourceMode has been explained. [0091] In this arrangement of the first embodiment, the types of the choices of the resolution of the compression encoding unit provided by the GetVideoEncoderConfigurationOptions command are not limited to those matching the VideoSourceMode. It is also possible to always provide all choices of the resolution to the client apparatus 2000 by the GetVideoEncoderConfigurationOptions command. In accordance with a new set value set in the compression encoding unit 1004 by the client apparatus 2000 by using the SetVideoEncoderConfiguration command, the monitoring camera 1000 may also internally switch the VideoSourceMode to a mode matching the new set value. [0092] The second embodiment of the present invention taking this point into consideration will be explained below. Note that an explanation of the same portions as those of the first embodiment will be omitted. [0093] FIG. 6D is a view showing processing when a monitoring camera 1000 has received the GetVideoSourceConfigurationOptions command from a client apparatus 2000 . [0094] In step S 1300 , a control unit 1001 refers to the table shown in FIG. 4 which is stored in a storage unit 1002 , and obtains all possible choices of the resolution of the VideoEncoderConfiguration. That is, the control unit 1001 obtains E 1 to E 4 in S 1 , E 1 to E 4 in S 2 , and E 1 to E 4 in S 3 as choices. [0095] In step S 1301 , the control unit 1001 refers to the table shown FIG. 4 which is stored in the storage unit 1002 , and obtains all possible choices of the compression encoding scheme of the VideoEncoderConfiguration. That is, the control unit 1001 obtains MotionJPEG and H.264 as choices. [0096] In step S 1302 , the control unit 1001 refers to the table shown in FIG. 4 which is stored in the storage unit 1002 , and obtains the maximum one of possible values of the FramerateLimit of the VideoEncoderConfiguration. That is, the control unit 1001 obtains 30 fps as the maximum value of the FramerateLimit. [0097] In step S 1303 , the control unit 1001 obtains the choices and setting range of the VideoEncoderConfiguration independent of the current VideoSourceMode from the storage unit 1002 . For example, the control unit 1001 obtains 1 to 5 as the settable range of the Quality, and 60 Mbps as the set value of the BitrateLimit. [0098] In step S 1304 , the control unit 1001 transmits a normal response containing the choices and setting range obtained in steps S 1300 to S 1303 to the client apparatus 2000 via a communication unit 1005 . [0099] FIG. 6E is a view showing processing when the monitoring camera 1000 has received the above-described SetVideoEncoderConfiguration command from the client apparatus 2000 . [0100] In step S 1400 , the control unit 1001 refers to the table shown in FIG. 4 which is stored in the storage unit 1002 , and determines whether the resolution set in the received SetVideoEncoderConfiguration command matches the current VideoSourceMode. If the resolution matches the mode (Yes in step S 1400 ), the control unit 1001 advances the process to step S 1201 . If the resolution does not match the mode (No in step S 1400 ), the control unit 1001 advances the process to step S 1410 . [0101] In step S 1410 , the control unit 1001 refers to the table shown in FIG. 4 which is stored in the storage unit 1002 , and switches the current VideoSourceMode to a VideoSourceMode having a matched input resolution. For example, when 640×480 is input as a Resolution to this command while the VideoSourceMode is S 1 , the VideoSourceMode is switched to S 3 matching this resolution. When the resolution is changed to a resolution different from the setting of an image capturing unit (the resolution of the VideoSourceMode) by the command for setting the resolution of the encoding unit (the resolution of a distribution image), the control unit 1001 changes the setting of the resolution of the image capturing unit to a resolution matching the resolution of the encoding unit. Processes in steps S 1201 to S 1204 and S 1210 are the same as those shown in FIG. 6C . [0102] FIG. 7B is a view showing an example of a setting screen of the client apparatus 2000 in which the VideoSourceMode and VideoEncoderConfiguration of the monitoring camera 1000 according to this embodiment are set. [0103] An area 9012 is an area for selecting the resolution of a VideoEncoderConfiguration 6103 . The GetVideoEncoderConfigurationOptions command is executed when the setting screen shown in FIG. 7B is opened. A dropdown list 9100 displays the contents of the choices of a Resolution parameter obtained by the GetVideoEncoderConfigurationOptions command. As shown in FIG. 6D , the monitoring camera 1000 according to this embodiment provides all resolutions obtained from the table shown in FIG. 4 as choices. Therefore, the dropdown list 9100 displays all the resolutions. [0104] The monitoring camera 1000 provides the client apparatus 2000 with all possible setting contents of the VideoEncoderConfiguration as choices, regardless of the VideoSourceMode. If a parameter of the VideoEncoderConfiguration not matching the current VideoSourceMode, which includes the resolution of a compression encoding unit 1004 , is designated, it is possible to internally switch to a matching VideoSourceMode. Accordingly, when obtaining a distribution image after the parameter of the VideoEncoderConfiguration is changed, the client apparatus 2000 need not change the setting contents of the VideoSourceMode to contents matching the VideoEncoderConfiguration. That is, even when various settings including the resolution of a distribution image to be generated by the compression encoding unit 1004 are changed, it is possible to prevent the occurrence of mismatching in the resolution of image data to be generated by an image capturing unit 1003 . It is also possible to facilitate generating a distribution image after the resolution is changed. [0105] The operations of the monitoring camera, application program, and client apparatus according to the present invention have been disclosed in the first and second embodiments. However, the spirit and scope of the invention are not limited to the above-described embodiments, and partially changeable. [0106] For example, in step S 1002 of FIG. 6A , the set values of the Resolutions of the VideoEncoderConfigurations are uniformly changed to a resolution having the same management number matching the VideoSourceMode. However, the spirit and scope of the present invention are not limited to this. For example, of the Resolutions of the VideoEncoderConfigurations, a Resolution that keeps matching before and after the VideoSourceMode is changed can also be kept used after the VideoSourceMode is changed. [0107] Also, all possible choices of the resolution of the VideoEncoderConfiguration are provided in step S 1300 of FIG. 6D , but the spirit and scope of the present invention are not limited to this. For example, it is also possible to provide only a resolution matching the current VideoSourceMode as a choice, only when a video stream having a given resolution has already been distributed from the monitoring camera 1000 . [0108] Furthermore, all possible compression encoding schemes of the VideoEncoderConfiguration are obtained as choices in step S 1301 of FIG. 6D , but the present invention is not limited to this. It is also possible to obtain only choices of compression encoding schemes matching all VideoSourceModes. This makes it possible to reduce the choice providing range, and prevent the SetVideoEncoderConfiguration command from designating compression encoding that does not match the VideoSourceMode selected at that point of time in step S 1201 . [0109] In addition, the maximum one of all possible values of the FramerateLimit of the VideoEncoderConfiguration is obtained in step S 1302 of FIG. 6D , but the present invention is not limited to this. For example, it is also possible to obtain the maximum FramerateLimit matching all VideoSourceModes. This makes it possible to reduce the choice providing range, and prevent the SetVideoEncoderConfiguration command from designating a FramerateLimit that does not match the VideoSourceMode selected at that point of time in step S 1201 . [0110] Also, in step S 1410 of FIG. 6E , VideoSourceModes are selectively switched based on the setting of the resolution of the SetVideoEncoderConfiguration command. However, the spirit and scope of the present invention are not limited to this. That is, a plurality of matching VideoSourceModes may exist. Accordingly, it is also possible to select the most matching VideoSourceMode based not only on the resolution but also on a plurality of other settings of the compression encoding unit, such as the compression encoding scheme and FramerateLimit. [0111] In the present invention as described above, even when only one of the resolution of image data to be generated by the image capturing unit and the resolution of a distribution image to be generated by the compression encoding unit is changed, it is possible to prevent the occurrence of mismatching in a combination of these resolutions. OTHER EMBODIMENTS [0112] Embodiments of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions recorded on a storage medium (for example, non-transitory computer-readable storage medium) to perform the functions of one or more of the above-described embodiment(s) of the present invention, and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment (s). The computer may comprise one or more of a central processing unit (CPU), micro processing unit (MPU), or other circuitry, and may include a network of separate computers or separate computer processors. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. [0113] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

An image capturing apparatus includes: an encoding unit configured to perform encoding processing on an image output from an image capturing unit for obtaining an image; a communication unit configured to receive designation of a resolution of the encoding unit from an information processing apparatus; an obtaining unit configured to obtain a resolution which is associated with the resolution set for the image capturing unit, and is settable for the encoding unit; a determination unit configured to determine whether the designated resolution is the resolution obtained by the obtaining unit and settable for the encoding unit; and a transmission unit configured to transmit an error response to the information processing apparatus, if the determination unit determines that the designated resolution is not the resolution obtained by the obtaining unit and settable for the encoding unit.

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] The present patent application/patent claims the benefit of priority of co-pending U.S. Provisional Patent Application No. 61/597,875, filed on Feb. 13, 2012, and entitled “WIDEBAND NEGATIVE-PERMITTIVITY METAMATERIALS AND NEGATIVE-PERMEABILITY METAMATERIALS,” the contents of which are incorporated in full by reference herein. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] The U.S. Government may have certain rights in the present invention pursuant to National Science Foundation Grant No. ECCS-1101939. FIELD OF THE INVENTION [0003] The present invention relates generally to the fields of electrical engineering and materials science. More specifically, the present invention relates to wideband negative-permittivity and negative-permeability metamaterials utilizing non-Foster elements. BACKGROUND OF THE INVENTION [0004] Metamaterials are defined as artificial materials that are engineered to have properties that are not found in nature, and that are not necessarily possessed by their constituent parts alone. In this sense, metamaterials are assemblies of multiple individual elements or unit cells, and they may be on any scale, from nano to bulk. [0005] Metamaterials offer tremendous potential in a wide range of applications, including, but not limited to, negative refraction, wideband antennas near metal, flat lenses, and cloaking Although there has been considerable progress in passive metamaterials, the bandwidth of these devices remains limited by the resonant behavior of the fundamental particles or unit cells comprising the metamaterials. In contrast, non-Foster circuit elements offer the possibility of achieving performance capabilities well beyond the reach of passive components. As is well known to those of ordinary skill in the art, non-Foster circuit elements are those that do not obey Foster's theorem. A complete wideband double-negative metamaterial design has remained elusive, but is provided by the present invention through the use of non-Foster circuit elements. As is also well known to those of ordinary skill in the art, non-Foster circuit elements can be constructed from arrangements of capacitors, inductors, and active devices, such as Linvill circuits, current conveyors, cross-coupled transistors, tunnel diodes, etc. [0006] The closest known art (although not necessarily pre-dating the present invention) is that of Colburn et al. (U.S. Patent Application Publication No. 2012/0256811). Colburn et al. provide: A tunable impedance surface, the tunable surface including a plurality of elements disposed in a two dimensional array; and an arrangement of variable negative reactance circuits for controllably varying negative reactance between at least selected ones of adjacent elements in the aforementioned two dimensional array. [0008] The tunable impedance surface of Colburn et al., however, suffers from several significant shortcomings, including, but not limited to: the fact that it is inherently limited to a two-dimensional (2-D) surface, rather than a three-dimensional (3-D) volume; its requirement for a ground plane; and the fact that it only addresses 2-D negative inductance methods, rather than 3-D negative permittivity methods, negative permeability methods, and double-negative metamaterials that exhibit simultaneous negative permittivity and negative permeability. Further, the tunable impedance surface of Colburn et al. considers the stability of non-Foster circuits, but does not consider a metamaterial design wherein a negative capacitive element or negative inductive element is combined with a positive capacitive element or positive inductive element, resulting in a stable element with a net positive inductance or net positive capacitance. BRIEF SUMMARY OF THE INVENTION [0009] In various exemplary embodiments, the present invention provides a novel wideband double-negative metamaterial having simultaneous negative relative permittivity and negative relative permeability (with both relative permittivity E r and relative permeability μ r below 0), from 1.0 to 4.5 GHz, for example. Further, in various exemplary embodiments, the present invention provides a novel wideband metamaterial having simultaneous permittivity and permeability below 1 (with both relative permittivity ε r and relative permeability μ r below 1), from 1.0 to 4.5 GHz, for example. Non-Foster loads, such as negative capacitors, negative inductors, and negative resistors, which operate at many frequencies, are coupled to electric and/or magnetic fields using single split-ring resonators (SSRRs), electric disk resonators (EDRs) consisting of two metal disks connected by a metal rod or wire, and other suitable coupling devices. The designs of the loads for the SSRR and EDR that comprise the unit cell are based on an analysis of the coupled fields. The required negative inductance load of the SSRR is derived using Faraday's law of induction, the geometry of the coupling device, and the incident magnetic field. The required negative capacitance load of the EDR is derived using Ampere's circuital law, the geometry of the coupling device, and the incident electric field. The results from Faraday's law and Ampere's law are then used to compute the magnetic and electric dipole moments of the unit cell, and to derive the effective permittivity and effective permeability. This straightforward analysis leads to a relatively simple expression for the resulting negative effective permittivity and negative effective permeability of the unit cell as a function of frequency, with the elimination of typical resonant behavior. As is well known to those of ordinary skill in the art, mixing effects, such as the Maxwell Garnett equation, Bruggeman's Effective Medium Theory, and the Landau-Lifshits-Looyenga mixing rule, are included in a more detailed analysis. [0010] In one exemplary embodiment, the present invention provides a metamaterial exhibiting an effective relative permeability below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has a magnetic dipole moment that is dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to a device. Optionally, the coupling mechanism is a split ring. Other exemplary coupling mechanisms that can be used include SSRRs, EDRs, double split-ring resonators (DSRRs), electric-LC resonators, omega particles, capacitively-loaded strips, cut-wire pairs, complementary split-ring resonators (CSRRs), dipoles, asymmetric triangular electromagnetic resonators, S-shaped resonators, etc. The device is a non-Foster element. Optionally, the non-Foster element includes an arrangement of one or more negative capacitors. Alternatively, the non-Foster element includes an arrangement of one or more negative inductors. Alternatively, the non-Foster element includes an arrangement of one or more negative resistors. Alternatively, the non-Foster element includes an arrangement of a negative capacitor in parallel with a negative inductor. Other possibilities, of course, include various combinations and arrangements of negative capacitors, negative inductors, positive capacitors, positive inductors, resistors, negative resistors, transistors, and/or diodes to achieve the desired frequency dependent non-Foster impedances. [0011] In another exemplary embodiment, the present invention provides a metamaterial exhibiting an effective relative permittivity below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has an electric dipole moment that is dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to a device. Optionally, the coupling mechanism is a pair of parallel plates coupled by one of a rod and a wire. Other exemplary coupling mechanisms that can be used include EDRs, SSRRs, DSRRs, electric-LC resonators, omega particles, capacitively-loaded strips, cut-wire pairs, CSRRs, dipoles, asymmetric triangular electromagnetic resonators, S-shaped resonators, etc. The device is a non-Foster element. Optionally, the non-Foster element includes an arrangement of one or more negative capacitors. Alternatively, the non-Foster element includes an arrangement of one or more negative inductors. Alternatively, the non-Foster element includes an arrangement of one or more negative resistors. Other possibilities, of course, include various combinations and arrangements of negative capacitors, negative inductors, positive capacitors, positive inductors, resistors, negative resistors, transistors, and/or diodes to achieve the desired frequency dependent non-Foster impedances. [0012] In a further exemplary embodiment, the present invention provides a metamaterial simultaneously exhibiting an effective relative permeability and an effective relative permittivity below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has a magnetic dipole moment and an electric dipole moment that are dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to a device. Optionally, the coupling mechanism includes one or more of a split ring and a pair of parallel plates coupled by one of a rod and a wire. Other exemplary coupling mechanisms that can be used include SSRRs, EDRs, DSRRs, electric-LC resonators, omega particles, capacitively-loaded strips, cut-wire pairs, CSRRs, dipoles, asymmetric triangular electromagnetic resonators, S-shaped resonators, etc. The device is a non-Foster element. Optionally, the non-Foster element includes an arrangement of one or more negative capacitors. Alternatively, the non-Foster element includes an arrangement of one or more negative inductors. Alternatively, the non-Foster element includes an arrangement of one or more negative resistors. Alternatively, the non-Foster element includes an arrangement of a negative capacitor in parallel with a negative inductor. Other possibilities, of course, include various combinations and arrangements of negative capacitors, negative inductors, positive capacitors, positive inductors, resistors, negative resistors, transistors, and/or diodes to achieve the desired frequency dependent non-Foster impedances. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The present invention is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like structural components/method steps, as appropriate, and in which: [0014] FIG. 1 is a schematic diagram illustrating one exemplary embodiment of a magnetic unit cell of the metamaterial of the present invention, the magnetic unit cell incorporating a single split-ring resonator (SSRR) coupling device and a non-Foster element; [0015] FIGS. 2 a - 2 c are schematic diagrams illustrating exemplary embodiments of an electric unit cell of the metamaterial of the present invention, the electric unit cell incorporating an electric disk resonator (EDR) coupling device and a non-Foster element; [0016] FIG. 3 is a schematic diagram illustrating one exemplary embodiment of the double-negative metamaterial structure of the present invention, the structure incorporating three SSRR and three EDR coupling devices and six non-Foster elements; [0017] FIG. 4 is a plot illustrating exemplary simulation results for the structure of FIG. 3 ; [0018] FIG. 5 is a plot illustrating exemplary extracted values of the real parts of the effective relative permeability μ r and effective relative permittivity ε r for the structure of FIG. 3 ; [0019] FIG. 6 is a plot illustrating further exemplary simulation results for the structure of FIG. 3 when all three EDR coupling devices are removed; and [0020] FIG. 7 is a plot illustrating exemplary extracted values of the real and imaginary parts of the permeability μ r for the structure of FIG. 3 when all three EDR coupling devices are removed. DETAILED DESCRIPTION OF THE INVENTION [0021] Again, in various exemplary embodiments, the present invention provides a novel wideband double-negative metamaterial having simultaneous negative effective relative permittivity and negative effective relative permeability (with both relative permittivity ε r and relative permeability μ r below 0), from 1.0 to 4.5 GHz, for example. Further, in various exemplary embodiments, the present invention provides a novel wideband metamaterial having simultaneous effective relative permittivity and effective relative permeability below 1 (with both relative permittivity ε r and relative permeability μ r below 1), from 1.0 to 4.5 GHz, for example. Non-Foster loads, such as negative capacitors, negative inductors, and negative resistors, which operate at many frequencies, are coupled to electric and/or magnetic fields using SSRRs, EDRs consisting of two metal disks connected by a metal rod or wire, and other suitable coupling devices. The designs of the loads for the SSRR and EDR that comprise the unit cell are based on an analysis of the coupled fields. The required negative inductance load of the SSRR is derived using Faraday's law of induction, the geometry of the coupling device, and the incident magnetic field. The required negative capacitance load of the EDR is derived using Ampere's circuital law, the geometry of the coupling device, and the incident electric field. The results from Faraday's law and Ampere's law are then used to compute the magnetic and electric dipole moments of the unit cell, and to derive the effective permittivity and permeability. This straightforward analysis leads to a relatively simple expression for the resulting negative effective permittivity and negative effective permeability of the unit cell as a function of frequency, with the elimination of typical resonant behavior. As is well known to those of ordinary skill in the art, mixing effects, such as the Maxwell Garnett equation, Bruggeman's Effective Medium Theory, and the Landau-Lifshits-Looyenga mixing rule, are included in a more detailed analysis. [0022] The analyses and results of the present invention address the problem of narrow bandwidth in double-negative metamaterials, negative permittivity metamaterials, negative permeability metamaterials, metamaterials incorporating electromagnetic coupling devices, and metamaterials with effective relative permittivity and/or effective relative permeability below unity. In this, properly chosen non-Foster loads are shown to provide wideband negative effective permittivity, wideband negative effective permeability, wideband double-negative metamaterials, wideband electromagnetic coupling, and wideband metamaterials with relative permittivity and/or relative permeability below unity. In particular, the permeability of an SSRR becomes independent of frequency with a negative inductance load, and the permittivity of an EDR becomes independent of frequency with a negative capacitor load. Similar results for loop and dipole antennas have been noted. As is well known to those of ordinary skill in the art, various combinations and arrangements of negative capacitors, negative inductors, positive capacitors, positive inductors, resistors, negative resistors, transistors, and/or diodes to achieve the desired frequency dependent non-Foster impedances. [0023] The design of a non-Foster-loaded SSRR with wideband negative effective permeability is first considered. The design of a non-Foster-loaded EDR with wideband negative effective permittivity is then considered. Finally, simulation results of wideband double-negative metamaterials are given, with effective permittivity and permeability extracted from the S-parameters of the metamaterial. [0024] The well-known theory of an elementary lossless SSRR is first considered, since it is useful in describing the overall analysis approach for the proposed negative-permittivity metamaterials. Although other magnetic field coupling devices may have advantages and may be used, they would unnecessarily complicate the basic development outlined here. [0025] Consider the magnetic unit cell 10 and SSRR 12 illustrated in FIG. 1 that, in the prior art, is expected to exhibit typical narrowband resonant behavior. The dimensions of the unit cell 10 comprising this magnetic metamaterial particle are l x , l y , and l z , and the metal split ring 12 has an area A R . As usual, the dimensions of the unit cell 10 are considered to be significantly smaller than a wavelength. The incident magnetic field H o {circumflex over (x)} is parallel to the axis of the split ring 12 . [0026] As illustrated in FIG. 1 , the current in the split ring 12 is defined as i r , and the voltage across the gap is v g (this sign convention for i r and v g is later convenient for describing the current through the capacitance of the gap in the split ring 12 ). Using Faraday's law of induction, the gap voltage is: [0000] v g = -  Φ T  t = -  ( Φ 0 + Φ R )  t , ( 1 ) [0000] where Φ T is the total magnetic flux in the SSRR 12 , Φ 0 =μ 0 H 0 A R is the incident magnetic flux over the SSRR 12 , A R is the area of the SSRR 12 , μ 0 is the permeability of a vacuum, and Φ R is the magnetic flux due to i r . Then, the current in the ring 12 is: [0000] i r = C g   v g  t = - C g   2  ( Φ 0 + Φ R )  t 2 , ( 2 ) [0000] where C g is the total capacitance across the gap of the SSRR 12 . [0027] Taking the Laplace transform: [0000] i r =−s 2 C g (Φ 0 +Φ R )=− s 2 C g (Φ 0 +L R i r ),   (3) [0000] where the self-inductance of the SSRR 12 is L R =Φ R /i r . [0028] Solving for i r yields the frequency-dependent current: [0000] i r = - Φ 0  s 2  C g 1 + s 2  L R  C g , ( 4 ) [0029] Next, consider replacing the gap capacitance C g with a positive inductance L g with reactance X g =jωL g . The voltage v g now appears across this gap inductance L g . Then, the current in the split ring 12 becomes: [0000] i r = 1 L g  ∫ v g   t = - 1 L g  ∫  ( Φ 0 + Φ R )  t   t , ( 5 ) [0000] after substituting for v g from Eq. (1). Taking the integral, and again with L R =Φ R /i r , leads to: [0000] i r = - 1 L g  ( Φ 0 +    Φ R ) = - 1 L g  ( Φ 0 + L R  i r ) , ( 6 ) [0000] Then, solving for i r results in: [0000] i r = - Φ 0  1 L g + L R , ( 7 ) [0030] Comparing Eq. (7) with Eq. (4), the ring current i r in Eq. (7) no longer depends on frequency when the gap capacitance C g is replaced by inductance L g , allowing wideband behavior. [0031] The current in the loop gives rise to a magnetic dipole moment in the SSRR 12 of m=i r A r {circumflex over (x)}. The minus sign in Eq. (7) then results in m having a direction opposite to the applied field H 0 {circumflex over (x)}. The macroscopic magnetization M is then the magnetic dipole moment per unit volume: [0000] M = - Φ 0  A R l x  l y  l z  1 L g + L R  x ^ = - μ 0  H 0  A R 2 l x  l y  l z  1 L g + L R  x ^ , ( 8 ) [0000] where the permeability of free space is μ 0 =1.26×10 −6 H/m, and for the simplicity of exposition, well-known mixing effects, such as Bruggeman's Effective Medium Theory, are not included here. With M=χ m H and μ r =1+χ m , it follows that: [0000] μ r = 1 - μ 0  A R 2 l x  l y  l z  1 L g + L R , ( 9 ) [0000] where χ m is the magnetic susceptibility, and μ r is the effective relative permeability of the metamaterial. [0032] The proposed effective relative permeability μ r for the SSRR 12 given in Eq. (9) does not vary with frequency, and becomes a large negative value if L g is chosen to be negative, such that the denominator has (L g +L R )>0 and (L g +L R )≈0. Thus, a negative inductor load in the gap of a SSRR 12 can provide wideband negative effective permeability. The desired condition (L g +L R )>0 has the same form as a series combination of a negative inductor with a positive inductor whose resulting inductance remains positive. Non-Foster circuits, such as a negative inductor, can be designed using negative impedance converters, where recent progress has been made in potential stability issues. Further, the condition (L g +L R )>0 results in a net positive inductance, which leads to stability. The non-Foster element 16 is shown conceptually in FIG. 1 . [0033] Just as the theory of the SSRR 12 is developed above for wideband negative-permeability metamaterials, a similar approach is used to develop the theory for the proposed wideband negative-permittivity metamaterials. The analysis follows along similar lines as the analysis of the magnetic unit cell 10 of FIG. 1 . [0034] Consider the electric unit cell 20 and EDR 22 illustrated in FIG. 2 , resembling a three-dimensional version of an I-shaped structure. The dimensions of the unit cell 20 comprising this electric metamaterial particle are the same as the magnetic component of FIG. 1 , l x , l y , and l z . The metal disks near the top and bottom faces of the structure have areas A D , and are connected together by a metal post with inductance L p . As usual, the dimensions of the unit cell 20 are taken to be less than a wavelength, so that the incident electric field E 0 ŷ24 is uniform over the unit cell 20 . As illustrated in FIG. 2 , the current in the post that connects the two disks is i p , and the voltage between the upper and lower disks is v d . [0035] Using Ampere's circuital law and the Maxwell-Ampere equation, the time derivative of the total electric flux impinging upon the top face of the upper disk equals the current in the post plus the time derivative of total electric flux departing the bottom face of the top disk: [0000] i p =   t  Ψ F =   t  Ψ T , ( 10 ) [0000] where i p is the current in the post, Ψ T is the total electric flux in coulombs impinging upon the top face of the upper disk of the EDR 22 from sources external to the unit cell 20 , and Ψ F is the total electric flux that couples between the upper and lower EDR disks (i.e. internal to the unit cell 20 ). The left side of Eq. (10) then represents the total current (both circuit current and displacement current) flowing from the top disk to the bottom disk, and the right side represents the total displacement current coming from sources external to the unit cell 20 and impinging on the top disk of the EDR 22 . [0036] The internal electric flux Ψ F can be represented by a capacitance C F driven by the voltage v d across the two disks, and the external electric flux Ψ T can be represented by a capacitance C 0 coupling to the external voltage potential across the unit cell 20 ν 0 =E 0 l y , where E 0 ŷ is the incident electric field. Then, Eq. (10) becomes: [0000] i p =   t  ( v 0  C 0 - Ψ F ) =   t  ( v 0   C 0 - v d  C F ) , ( 11 ) [0000] where capacitance C F can also be thought of as a leakage capacitance or fringe capacitance around the post inductance. The voltage between the two disks also equals the voltage across the inductive post, so: [0000] v p = L p   i p  t = L p   2  t 2  ( v 0   C 0 - v d  C F ) , ( 12 ) [0000] where v d is the voltage from the top disk to the bottom disk, as before, and L p is the inductance of the metal post connecting the two disks. Taking the Laplace transform results in: [0000] ν d =s 2 L p (ν 0 C 0 −ν d C F ).   (13) [0037] Solving for the voltage v d then gives: [0000] v d = v 0  s 2  L p  C 0 1 + s 2  L p  C F . ( 14 ) [0038] Next, consider replacing the inductive post L p with a positive capacitance C p with reactance X p =−j/(ωC p ). The current i p then flows through this capacitance and the voltage v d now appears across this capacitance, so: [0000] v d = 1 c p  ∫ i p   t = 1 c p  ∫   t  ( v 0  C 0 - v d  C F )   t , ( 15 ) [0000] after substituting for i p from Eq. (11). Simplifying and solving for v d results in: [0000] v d = 1 c p  ( v 0  C 0 - v d  C F ) = v 0  c 0 c p + c F . ( 16 ) [0039] Comparing Eq. (16) with Eq. (14), note that the voltage v d in Eq. (16) no longer depends on frequency when the post inductance L p is replaced by C p , thus allowing wideband behavior. [0040] The charge on the disks then gives rise to an electric dipole moment: [0000] p = q   l p  y ^ = v d  C p  l p  y ^ = v 0  C 0  l p  c p c p + c F  y ^ , ( 17 ) [0000] where ±q is the charge in coulombs on the disks, p is the electric dipole moment in the same direction as the applied field E 0 ŷ, and l p is the distance between the two disks. In Eq. (17), the charge on the bottom disk is q=∫i p dt and ν d =(1/C p )∫i p dt, so q=ν d C p . Then, polarization P equals electric dipole moment per unit volume: [0000] P = p l x  l y  l z = E 0  c 0  l p l x  l z  ( c p c p + c F )  y ^ , ( 18 ) [0000] after substituting E 0l l y =ν 0 , and for the simplicity of exposition, well-known mixing effects, such as Bruggeman's Effective Medium Theory, are again not included here. With P=χ e ε 0 E and E r =1+χ e , the relative permittivity ε r is: [0000] ε r = 1 + c 0  l p ε 0  l x  l z  ( c p c p + c F ) , ( 19 ) [0000] where χ e is the electric susceptibility, ε r is the effective relative permittivity of the metamaterial, and ε 0 =8.85×10 −12 F/m is the permittivity of free space. [0041] Therefore, the effective relative permittivity ε r of the EDR 22 in Eq. (19) does not vary with frequency, just as there was no frequency dependence in μ r for the SSRR 12 result of Eq. (9). The effective permittivity ε r becomes a large negative value if C p is chosen to be negative, such that the denominator has C p +C F ≈0 and C p +C F >0. Thus, a negative capacitor load replacing the post of an EDR 22 can provide wideband negative effective permittivity. The desired condition C p +C F >0 has the same form as a parallel combination of a negative capacitor with a positive capacitor whose resulting capacitance remains positive. Further, the condition C p +C F >0 results in a net positive capacitance, which leads to stability. Non-Foster circuits, such as a negative capacitor, can be designed using negative impedance converters, where recent progress has been made in potential stability issues. The non-Foster element 26 is shown conceptually in FIG. 2 b , where the non-Foster element 26 coupled the two disks 23 , with the non-Foster element 26 replacing the inductive post of the EDR 22 . In an alternative arrangement shown in FIG. 2 c , the inductive post of the EDR 22 is cut in two, with the non-Foster element 27 coupling the remaining portions of the split EDR 29 . Furthermore, in some applications, metamaterials do not necessarily need to exhibit negative permittivity and/or negative permeability, since devices with non-negative refractive indices less than unity or near zero can also be useful. [0042] The wideband double-negative metamaterial test structure 30 illustrated in FIG. 3 was chosen to illustrate the performance of the proposed design. The structure consisted of three unit cells 31 , 32 , and 33 within a parallel-plate waveguide 34 with perfect electric conductor top and bottom walls separated by h=10 mm, and perfect magnetic conductor side walls separated by w=8 mm. The separation between unit cells was d=8 mm. The SSRR 12 had a radius of 3.2 mm with a 1-mm gap, and the EDR 22 was comprised of two disks 7 mm apart with 3.2-mm radius and a connecting post of 0.15-mm radius. The EDR 22 and SSRR 12 were centered within the waveguide 34 , with 1-mm space between the EDR post and SSRR ring. Each EDR 22 had a 1-mm gap in its post with a negative capacitance of Cp=−240 fF placed in the gap. Each SSRR 12 had a 1-mm gap in its ring with a negative inductance of Lp=−10 nH placed in the gap. In addition, a negative capacitance of −45 fF was placed in parallel to Lp to compensate for stray capacitance in the ring 12 to help improve bandwidth. [0043] The structure 30 of FIG. 3 was tested in the HFSS 3D electromagnetic simulator. FIG. 4 illustrates the S-parameter simulation results for S 21 for three cases. The solid curve with circles 40 in FIG. 4 illustrates |S 21 | in dB for the entire structure 30 of FIG. 3 , and illustrates wideband double-negative behavior with less than 2 dB loss from 1.0 to 4.5 GHz. The dotted curve with triangles 42 illustrates |S 21 | for the three SSRR devices 12 , with the three EDR devices 22 removed. In the dotted curve 42 , the insertion loss is due to the negative effective permeability of the three SSRR devices 12 alone. The dashed curve with diamonds 44 shows |S 21 | for the three EDR devices 22 , with the three SSRR devices 12 removed. In the dashed curve 44 , the insertion loss is due to the negative effective permittivity of the three EDR devices 22 alone. [0044] The effective permeability and effective permittivity of the three unit cell structure 30 of FIG. 3 were extracted from the S-parameters of FIG. 4 , drawing upon common methods. FIG. 5 illustrates the real part of the effective relative permittivity (solid curve with squares 50 ) and the real part of the effective relative permeability (dashed curve with circles 52 ), both on a linear scale. The dotted curve with triangles 54 shows |S 21 | in dB for reference. Note that both the real parts of the relative permittivity ε r and relative permeability μ r remain negative from 1.0 to 4.5 GHz. Near 1 GHz, the real part of ε r approaches −3.5, while the real part of μ r approaches −0.3. Near 5 GHz, ε r becomes positive while μ r remains negative, suggesting an evanescent nonpropagating condition above 4.5 GHz. Also, the attenuation greatly increases above 5 GHz, as would be expected when ε r becomes positive while μ r remains negative. Further, the effective relative permittivity is between 0 and 1 from 5 GHz to 7 GHz. [0045] Analysis and simulation results for the proposed non-Foster metamaterial 30 confirm wideband double-negative behavior. Effective permittivity and permeability were extracted from S-parameters and confirm simultaneous negative permittivity and negative permeability from 1.0 to 4.5 GHz. [0046] Again, magnetic metamaterial unit cells 10 are commonly narrowband and dispersive. However, the appropriate use of non-Foster elements 16 can increase the bandwidth of the metamaterials. Therefore, the present invention further addresses the deleterious effects of parasitic fringe capacitance on the bandwidth of a SSRR 12 when loaded with an ideal non-Foster circuit element 16 . Analysis of the parasitics leads to modified equations for effective permeability, and simulation results confirm the potential for significantly improved bandwidth. [0047] For simplicity, a lossless SSRR 12 is used to illustrate the influence of parasitic fringe capacitance on the effective permeability of the metamaterial when using non-Foster elements 16 . Consider again the SSRR 12 illustrated in FIG. 1 , centered in a unit cell 10 with dimensions l x , l y , and l z . The area of the SSRR 12 is A R and the incident magnetic field H 0 14 is parallel to the axis of the SSRR 12 . Due to the change in the magnetic field, a voltage v g appears across the gap of the ring 12 . The gap in the ring 12 can be modeled as a capacitance C g . The current i r in the ring 12 and through capacitance C g is then: [0000] i r = C g   v g  t = - C g   2  ( Φ 0 + Φ R )  t = - Φ 0  s 2  C g 1 + s 2  L R  C g , ( 20 ) [0000] where s is the Laplace complex angular frequency, L R =Φ R /i r is self-inductance, ν g =−d(Φ 0 +Φ R )/dt, Φ 0 is the incident magnetic flux, and Φ R is the magnetic flux due to i r . The well-known result in Eq. (20) describes the conventional narrowband behavior of a SSRR 12 , where the magnetic resonance frequency can be defined as ω 0m −1/√{square root over ( L R C G )}. [0048] Next, consider replacing gap capacitance C g with a positive inductance L g with reactance X L =jωL g . The ring current i r then becomes: [0000] i r = 1 L g  ∫ v g   t = - 1 L g  ( Φ 0 + Φ R ) = - Φ 0  1 L g + L R . ( 21 ) [0049] Comparing Eq. (20) with Eq. (21), the current in the split ring 12 is now frequency independent and broadband behavior is possible with proper choice of inductance L g . [0050] In some cases, however, capacitance C g cannot be removed completely, and some parasitic fringe capacitance C Fg will remain. As a result, the equivalent circuit in the gap of the split-ring 12 is now a parallel combination of inductance L g and fringe capacitance C Fg . Modifying Eq. (21) with C Fg yields: [0000] i r = i C Fg + i L g = C Fg   v g  t + 1 L g  ∫ v g   t , ( 22 ) [0000] where i CFg is the current through fringe capacitance C Fg , and i Lg is the current through inductance L g . Substituting ν g =−d(Φ 0 +Φ R )/dt in Eq. (22), taking the Laplace transform, and including self-inductance L R yields: [0000] i r = - Φ 0  1 + s 2  C Fg  L g L R + L g  ( 1 + s 2  C Fg  L R ) , ( 23 ) [0000] The result in Eq. (23) indicates that two resonance frequencies exist. [0051] To find the effective permeability, the magnetic dipole moment is used. The current in the SSRR 12 creates a magnetic dipole moment m=(i r A R ), and the macroscopic magnetization is then M=(i r A R )/(l x l y l z ). Since M=χ m H, μ r =1+χ m , and Φ 0 =μ 0 H o A R , the relative permeability, μ r , equals: [0000] μ r = 1 - μ 0  A R 2 l x  l y  l z  1 - ω 2  C Fg  L g L R + L g  ( 1 - ω 2  C Fg  L R ) , ( 24 ) [0000] where χ m is the magnetic susceptibility, ω is the angular frequency, μ 0 =1.26×10 −6 H/m is the permeability of free space, and s=jω was used, and for the simplicity of exposition, well-known mixing effects, such as Bruggeman's Effective Medium Theory, are again not included here. [0052] Finally, the parasitic fringe capacitance C Fg can theoretically be canceled by adding a parallel negative capacitance of equal value such that Eq. (24) becomes: [0000] μ r = 1 - μ 0  A R 2 l x  l y  l z  1 L R + L g , ( 25 ) [0000] and μ r once again becomes frequency independent, making wideband negative effective permeability possible when L g is negative, L R +L g >0, and L R +L g ≈0, according to Eq. (25). [0053] Again, the metamaterial structure 30 illustrated in FIG. 3 was simulated with three SSRR devices 12 in a parallel-plate waveguide 34 with perfect electric conductor top and bottom walls and with perfect magnetic conductor side walls, however, with the three EDRs 22 removed in the following three cases. Three cases were simulated. The first case used conventional SSRR devices 12 without non-Foster circuit elements 16 . In the second case, all three SSRR devices 12 were loaded with negative capacitance of −47 fF and negative inductance of −16.7 nH to confirm wideband behavior as predicted in Eq. (25). In the final case, the negative capacitance was removed and all three SSRR devices 12 were only loaded with a negative inductance. For the three cases simulated, S 21 is plotted in FIG. 6 and extracted real and imaginary parts of the effective relative permeability are illustrated in FIG. 7 . For both FIGS. 6 and 7 , the solid 60 and circle 62 curves describe the conventional narrowband behavior. The magnetic resonance occurs near 2.5 GHz. The dotted 64 and dashed (square) 66 curves illustrate wideband behavior from 0.5 to 4.5 GHz, when both the negative inductance and negative capacitance are present. The dashed 68 and triangle 70 curves depict the result when the negative capacitance is removed. [0054] The deleterious effects of fringe capacitance were analyzed and found, in some cases, to limit the bandwidth of negative effective permeability in non-Foster-loaded SSRRs. The analysis and simulation results demonstrate that a non-Foster load with both negative inductance and negative capacitance is required for wideband behavior, in some cases. As is well known to those of ordinary skill in the art, arrangements of the SSRRs and EDRs of FIG. 3 can be configured to respond to fields along different axes, along two axes, or along all three axes to provide an isotropic medium. An exemplary isotropic medium would orient the unit cells of FIG. 3 along the x, y, and z axes. [0055] As illustrated in the exemplary embodiments provided herein above, the present invention provides wideband metamaterials using non-Foster elements, with inherent stability advantages, and that can be used in a three-dimensional volume, can provide wideband relative permittivity less than unity, can provide wideband relative permeability less than unity, can provide wideband simultaneous relative permittivity and relative permeability less than unity, can provide wideband negative relative permittivity, can provide wideband negative relative permeability, can provide wideband simultaneous negative relative permittivity and negative relative permeability, that does not require a ground plane, and that can compensate for the deleterious effects of stray capacitance. In applications where instability is desirable, such as in oscillators, it is straightforward to violate the stability conditions noted throughout. [0056] Although the present invention has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present invention, are contemplated thereby, and are intended to be covered by the following claims.

A metamaterial simultaneously exhibiting a relative effective permeability and a relative effective permittivity below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has a magnetic dipole moment and an electric dipole moment that are dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to one or more devices. Optionally, the coupling mechanism includes one or more of a split ring and a pair of parallel plates coupled by one of a rod and a wire. The one or more devices are non-Foster elements.

FIELD OF THE INVENTION [0001] The present invention provides for an external capsule for holding fluid material suitable for preserving a medical device or the like, wherein the external capsule has a main body formed of cyclic olefin copolymer (COC). Furthermore, the present invention also provides for a package with an external capsule for preserving a dental implant or the like of the type described in U.S. Pat. No. 6,261,097 which was assigned to the assignee of the present invention and the full content of which is herewith incorporated by reference. BACKGROUND ART [0002] Medical devices such as dental implants may require for a better and long-term preservation to be stored in a fluid. [0003] To ensure a proper functioning of medical devices, they need to be protected from undergoing changes during the storage. [0004] The primary package with the external capsule wherein the medical devices are stored should then contain a fluid, whose composition, characteristics and quantity should be kept constant for a long period of time. [0005] Also the environmental condition (e.g. high humidity or dryness) should not alter the properties of the stored fluid and thus of the device immersed in said fluid, so as to ensure the same preservation standard all over the world. SUMMARY OF THE INVENTION [0006] It is therefore an object of the present invention to provide fox an external capsule for holding fluid material suitable for preserving a medical device such as a dental implant, wherein the external capsule is formed of a material which ensures a good long time storage and which is not influenced by environmental condition. [0007] Another object of the present invention is to provide for a package with an external capsule for preserving a dental implant in a fluid, such that to ensure a good long time storage and avoid influence by environmental condition. [0008] The above object as well as further objects which will become apparent hereinafter are achieved by an external capsule as defined in independent claim 1 and by a package for preserving a medical device or the like as defined in independent claims 2 through 4 . Further advantageous aspects of the invention are set forth in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The foregoing and other objects, features, and advantages of the invention, as well as presently preferred embodiments thereof, will become more apparent from a reading of the following description, in connection with the accompanying drawings in which: [0010] FIG. 1 is a generic package with an external capsule as shown in the prior art according to U.S. Pat. No. 6,261,097; and [0011] FIG. 2 is a plot which shows a relative comparison of the oxygen and water vapor permeability of various components of a package including an external capsule, a cap etc. formed with various materials. DESCRIPTION OF THE INVENTION [0012] With reference to FIG. 1 there is shown a generic package with an external capsule and an ampule for a dental implant as known from U.S. Pat. No. 6,261,097. [0013] According to U.S. Pat. No. 6,261,097 there is provided, as shown in prior art FIG. 1 , an implant 1 and a holding element 100 with an extension element 121 releasably associated with the implant 1 . In the assembled state, an ampoule 200 , with the implant 1 held therein by the holding element 100 , is inserted into an external capsule 300 . The external capsule 300 comprises a hollow cylinder 310 , the base 311 of which is closed, and a screw-on closure cap 320 . On the inside of the cylinder 310 , parallel to and at a distance from the base 311 , there is a support shoulder 313 , which is intended to act as an axial stop for the first planar base side on a fixing part 210 of the inserted ampoule 200 . In this case, the support shoulder 313 comprises four webs which are offset through 90 DEG in each case. The closure cap 320 points towards a stand part 220 of the ampoule 200 . At most in the region of the clearance between the second planar base side on the stand part 220 and the closure cap 320 , the ampoule 200 can move on the axis M and otherwise lies in a stable position in the external capsule 300 in the event of vibrations. [0014] The implant 1 is held by a holding element 100 with a screw 101 and a sleeve part 102 . An externally threaded part 131 of the screw 101 , which projects through the sleeve part 102 , engages in an internally threaded bore 14 on the implant 1 , while a mating shoulder 161 of a shoulder part 160 of the sleeve part 102 rests on an implant shoulder. A fixing part 110 of the holding element 100 is latched into the fixing part 210 of an ampoule 200 , i.e. the cylindrical section 116 of the holding element 100 is clamped in a laterally open indent 212 in the ampoule 200 and is surrounded laterally by the two jaws 215 , 216 . The annular shoulders of the holding element 100 bear against the fixing part 210 on both sides. In this way, the implant 1 is held in line with the center axis M inside the ampoule 200 without coming into contact with the ampoule 200 . [0015] The Applicants of the present invention found that the control of the above mentioned parameters, namely the composition characteristics and quantity of the fluid may be achieved by an appropriate external capsule. In addition, the control can be improved by an appropriate overall package. Particularly relevant for this purpose is the selection of the material from which the external capsule and/or the package are made. In fact, in a device manufactured according to the principles of the present invention the liquid level could be kept constant over a period of 5 years. [0016] Specifically it has been found that in order to prevent evaporation of the fluid present in the external capsule or in the overall package, the material that constitutes said external capsule and/or the overall package should posses a low water or fluid vapor permeability and a low gas permeability. [0017] Glass generally offers an excellent low water vapor and low gas permeability. Furthermore, it is transparent, and thus allows the device to be seen by the user, this being an highly desirable characteristic. However, glass containers are not easy to be handled in that they are heavy and breakable. [0018] The conventional polymers used in the medical package field such as styrene butadiene copolymer (SBS), Poly(methyl methacrylate) (PMMA), polystyrene (PS) and polyester (PET) do not offer the desired low water vapor and gas permeability that allows a long term storage of the medical device. [0019] In view of the above there is then the need of new containers for medical devices to be stored in a fluid which offer the advantage of the glass container (low water vapor, low gas permeability, and transparency) without however being affected by the drawbacks of the containers made of glass. Moreover, there is the need to avoid the disadvantages of the conventional polymers. [0020] Accordingly, the Applicants have found that the external capsule is advantageously manufactured from cyclo-olefin copolymer (COC) or the like, which is a plastic material with an excellent impermeability to moisture (less than 5%, preferably less than 1% fluid loss per year) and good impermeability to gas, as shown in FIG. 2 . At the same time COC is transparent and can be sterilized and has full medical device certification (FDA, CE). COC may also advantageously be used to manufacture the ampoule in view of its good hydrophobic properties (less than 0.01% fluid absorption in 24 hours at 23° C.), such that the overall shape of the ampoule does not change while immersed in a fluid. [0021] COC also combines excellent electrical properties with low density, high stiffness and strength therefore leading to a light, resistant overall package. Because of the chemical structure of the COC it emits no ions or heavy metals that could affect the stored fluid. [0022] Moreover, an improvement in the oxygen and fluid vapor impermeability can be achieved by coating the COC of the external capsule with a SiOx coat, as shown in FIG. 2 . [0023] The cap of the present package may be advantageously manufactured from a polymer. High density polyethylene (HDPE) or low density polyethylene (LDPE) has proven to be particularly advantageous for caps. Also polypropylene (PP) was proven to perform in a satisfactory manner for certain application. [0024] Further, the cap can be replaced by a sealing barrier or used together with the sealing barrier, such that a particularly good impermeability is provided in conjunction with the external capsule made of COC. Preferably, the sealing barrier is embodied as an aluminum membrane closing the open end of the capsule. Nevertheless, titanium or polymer membranes can also be used. [0025] In addition, the combination of a COC capsule with a HDPE or LDPE cap and/or the sealing barrier provides for an excellent shelf life of the medical device stored therein, particularly if a storage fluid, such as an electrolyte or an aqueous solution, is used. The shelf life is further improved by the COC ampule which does not change its shape by soaking up with fluid. [0026] The overall package impermeability can be improved by including the package in a protective blister FIG. 2 ). [0027] The foregoing description of the invention, including the preferred embodiments thereof, has been presented for the purpose of illustration and description. It is not intended to be exhaustive nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above teachings. In particular, a person skilled in the relevant art will readily understand that the external capsule/package and the ampoule are not limited to the use with dental implants. Rather the external capsule/package and the ampoule may by used in connection with other medical or non-medical devices providing the same handling and sterility maintenance advantages as described hereinbefore. Furthermore, the present invention is not limited to the package shown in present prior art FIG. 1 according to U.S. Pat. No. 6,261,097 but may be used with any kind of similar packages, such as those according to the concurrently filed application with the title “Package for Preserving a Medical Device or the Like” (attorney docket 2771), the full content of which is also herewith incorporated by reference. [0028] The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, the foregoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the following claims. [0029] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included just for the sole purpose of increasing intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

The present invention relates to an external capsule for holding fluid material suitable for preserving medical device, in particular a dental implant, wherein the external capsule is formed of cyclic olefin copolymer.

RELATED APPLICATIONS [0001] This application is a continuation in part of application Ser. No. 10/785,059 filed Feb. 25, 2004, claiming the benefit of U.S. Provisional Application 60/449,849 filed on Feb. 27, 2003. [0002] This application is also one of the below listed applications being concurrently filed: [0003] GEH01 00166 Application Serial No. ______ entitled “Scheduler and Method for Managing Unpredictable Local Trains”; [0004] GEH01 00167 Application Serial No. ______ entitled “Method And Apparatus For Optimizing Maintenance Of Right Of Way”′ [0005] GEH01 00169 Application Serial No. ______ entitled “Method And Apparatus For Selectively Disabling Train Location Reports”; [0006] GEH01 00170 Application Serial No. ______ entitled “Method And Apparatus For Automatic Selection Of Train Activity Locations”; [0007] GEH01 00171 Application Serial No. ______ entitled “Method And Apparatus For Congestion Management”; [0008] GEH01 00172 Application Serial No. ______ entitled Method And Apparatus For Automatic Selection Of Alternative Routing Through Congested Areas Using Congestion Prediction Metrics”; and [0009] GEH01 00173 Application Serial No. ______ entitled “Method and Apparatus for Estimating Train Location”. [0010] The disclosure of each of the above referenced applications including those concurrently filed herewith is hereby incorporated herein by reference. BACKGROUND OF THE INVENTION [0011] The present invention relates to the scheduling of movement of plural units through a complex movement defining system, and in the embodiment disclosed, to the scheduling of the movement of freight trains over a railroad system, and particularly to an interface between a line of road movement planner and a yard movement planner. [0012] Systems and methods for scheduling the movement of trains over a rail network have been described in U.S. Pat. Nos. 6,154,735, 5,794,172, and 5,623,413, the disclosure of which is hereby incorporated by reference. [0013] As disclosed in the referenced patents and applications, the complete disclosure of which is hereby incorporated herein by reference, railroads consist of three primary components (1) a rail infrastructure, including track, switches, a communications system and a control system; (2) rolling stock, including locomotives and cars; and, (3) personnel (or crew) that operate and maintain the railway. Generally, each of these components are employed by the use of a high level schedule which assigns people, locomotives, and cars to the various sections of track and allows them to move over that track in a manner that avoids collisions and permits the railway system to deliver goods to various destinations. [0014] As disclosed in the referenced applications, a precision control system includes the use of an optimizing scheduler that will schedule all aspects of the rail system, taking into account the laws of physics, the policies of the railroad, the work rules of the personnel, the actual contractual terms of the contracts to the various customers and any boundary conditions or constraints which govern the possible solution or schedule such as passenger traffic, hours of operation of some of the facilities, track maintenance, work rules, etc. The combination of boundary conditions together with a figure of merit for each activity will result in a schedule which maximizes some figure of merit such as overall system cost. [0015] As disclosed in the referenced applications, and upon determining a schedule, a movement plan may be created using the very fine grain structure necessary to actually control the movement of the train. Such fine grain structure may include assignment of personnel by name as well as the assignment of specific locomotives by number and may include the determination of the precise time or distance over time for the movement of the trains across the rail network and all the details of train handling, power levels, curves, grades, track topography, wind and weather conditions. This movement plan may be used to guide the manual dispatching of trains and controlling of track forces, or provided to the locomotives so that it can be implemented by the engineer or automatically by switchable actuation on the locomotive. [0016] The planning system is hierarchical in nature in which the problem is abstracted to a relatively high level for the initial optimization process, and then the resulting course solution is mapped to a less abstract lower level for further optimization. Statistical processing is used at all levels to minimize the total computational load, making the overall process computationally feasible to implement. An expert system is used as a manager over these processes, and the expert system is also the tool by which various boundary conditions and constraints for the solution set are established. The use of an expert system in this capacity permits the user to supply the rules to be placed in the solution process. [0017] Currently, a dispatcher's view of the controlled railroad territory can be considered myopic. Dispatchers view and processes information only within their own control territories and have little or no insight into the operation of adjoining territories, or the railroad network as a whole. Current dispatch systems simply implement controls as a result of the individual dispatcher's decisions on small portions of the railroad network and the dispatchers are expected to resolve conflicts between movements of objects on the track (e.g. trains, maintenance vehicles, survey vehicles, etc.) and the available track resource limitations (e.g. limited number of tracks, tracks out of service, consideration of safety of maintenance crews near active tracks) as they occur, with little advanced insight or warning. [0018] The problem is particularly severe where the territories differ significantly in function. For example, terminals or yards exist with a number of receiving tracks or leads and a number of departure tracks or leads. Multiple car trains arrive on various receiving leads and are broken up and reformed into multiple car trains of departure leads. Coordination between the line-or-road dispatcher and the yardmaster to insure that an incoming train is received on a receiving line with access to the appropriate yard for the reconfiguration of the train. Likewise, the line-of-road dispatcher must know the departure line in order to plan the movement of the train after it leaves the yard. [0019] As disclosed in the referenced applications, movement planners are available for planning the movement of trains within the various territories. Where one territory is a yard or a terminal, the line-of-road planning for the areas outside of the yard or terminal was necessarily independent of the planning for the terminal. [0020] The movement planner for the line-of-road and the yard have been completely independent with communication between the yard master and the dispatcher typically accomplished on an ad hoc basis using radio or telephone as an issue arose. Such communication does not allow for sufficient coordination between the planned movement of the cars in the yard and the planned movement of the trains in the line of road to optimize the movement of the trains through the railway network. [0021] Moreover, the yardmaster's movement plan is based on scheduled arrival and departure times, and updated information is generally not communicated to the yardmaster as the trains approach the terminal and often require significant revision. As a result, the use of yard resources has been inefficient. Likewise, the first accurate indication as to when a train is to be released to a line-of-road dispatcher is generally a telephone call from the yardmaster indicating that the train has been assembled and is ready for departure. Inefficiencies result from the change in the assignment of resources as is required by any departure from the anticipated departure time. [0022] More importantly, information line-of-road dispatchers deliver trains to a terminal without regard to terminal capacity, car connection requirements or congestion within the yard, and are generally evaluated on the speed with which trains are moved across the line-of-road. As a result, trains are often delivered to congested terminals by line-of-road dispatchers resulting in increased congestion and exacerbating the yardmaster's problems in reconfiguring the trains. A delay in the delivery of the train to the terminal may permit the yardmaster to operate more efficiently within the yard and improve overall system efficiency. This delay may also permit the use of road resources by other trains increasing the throughput of the system. [0023] Yardmasters are evaluated on the basis of the speed of assembly of trains within the yard without regard to road conditions or congestion, and often assemble trains for delivery to the line-of-road dispatcher without regard to the congestion of the road, exacerbating the dispatcher's problems in moving the trains. A delay in the delivery of a newly constructed train to the line-of-road may permit the line-of-road dispatcher to operate more efficiently and improve overall system efficiency. Knowing that little is gained by rushing the assembly of a particular train, the yardmaster may assign yard resources to other trains increasing the efficiency of the yard and the throughput of the system. In such a situation, a high value car may not get priority in the yard if the line-of-road exiting the terminal is congested. [0024] It is accordingly an object of the present invention to increase the coordination between the line-of-road and terminal planning systems through electronic connection, reducing voice communications and obviating the interruption of the respective dispatchers. The electronic connection of the movement planners results in continuously updated information and improved planning for both line-of-road and yard movement of trains, increasing the profitability of the overall transportation system. [0025] These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWING [0026] FIG. 1 is a functional block diagram illustrating the interface between the movement planner for the line-of-road and the movement planner for the yard. DETAILED DESCRIPTION [0027] The apparatus disclosed in the referenced applications may be used in the performance of the methods disclosed herein. Alternatively, and suitable conventional electronic interface may be employed so long as it has the capability of receiving output information from one movement planner and providing as input information to the other planner. [0028] With reference to FIG. 1 , a line-of-road movement planner 100 and a yard movement planner 110 may be provided as described in the referenced applications. Information, e.g., as to arrival times and arrival track information from the line-of-road planner 100 is desirably continuously passed to the yard planner 110 through the interface 120 where it may be displayed in a conventional manner to the yardmaster and/or automatically used by the yard movement planner 110 . [0029] Departure times and departure track information from the yard planner 110 is desirably continuously passed to the line-of-road planner 100 through the same electronic interface 120 where it may be displayed in a conventional manner to the line-of road dispatcher and/or automatically used by the line-of-road planner 100 . [0030] Status information as to the congestion of the yard and the road is useful to the planning process as it facilitates the identification of the activities required to move plural trains through the network of track and the assignment of resources to each of the identified activities. Both movement planners 100 and 110 may operate in the manner disclosed in the referenced applications to optimizing movement of the trains through the system as a function of cost of the identified activities and assigned resources. [0031] A railyard may include a number of sub yards with each sub yard designed to perform specific tasks. A train is that has not entered the rail yard is typically under the control of a line of road movement plan being executed by a dispatcher. As the train enters the railyard, the responsibility for the movement of the train is passed to railyard personal. The railyard personal will control the movement of the train pursuant to a railyard movement plan executed by a railyard planner. The railyard movement plan is different than the line of road movement plan in that t line of road movement plan considers a train as a single entity and plans the use of resources to move the train without conflict through the rail network. In the railyard, the train is divided into individual cars each being scheduled for specific tasks at specific locations and planned to be reconnected with other cars for a common destination in the rail network. Thus because the line of road planner and the railyard planner are responsible for scheduling different entities no attempt has been made at passing information between the line of road planner and the yard planner to optimize the movement of the trains through the rail network. [0032] One typical configuration of a railyard includes a receiving yard for receiving a train from a network of tracks. The receiving yard is one or more sets of track to receive the train and permit the railyard personal to inspect the train. Once the inspection is complete the locomotives are detached from the railcars and further inspection and maintenance is accomplished. The railcars are moved to the hump yard for classification. The hump yard includes a hill which feeds into a receiving bowl which allows the individual rail cars to be push to the hump and then gravity fed to the appropriate receiving bowl. A series of switches down stream of the hump, control the delivery of each car to its respective track. The railcars are classified in blocks of common destination. Once the railcars are classified in blocks, they are moved as blocks to the destination yard where each car is directed to a classification track based on its subsequent destinations. At the destination yard the cars are inspected and the train consist is brake tested and powered up. Thus, in one or more of the designated activities areas, congestion may develop in the yard. The yard planner in the present application can identify the congestion and evaluate the trains approaching the yard on the line of road through interface 120 . It may be advantageous to hold an approaching train outside the yard if the activity locations for that train's cars are not available. In another embodiment, the yard planner 110 can interface with the line of road planner 100 communicating that the yard is ready to receive a train that is further away rather than a train that is closer to the yard due to a specific condition of the yard. Thus the line of road movement planner 100 can make adjusts to its movement plan to alter the arrival sequence of the trains at the yard. [0033] In another embodiment, the line of road planner 100 may have planned the sequential departure of two trains from the yard. If the first train scheduled to depart is held up because of a problem with one of its cars, the yard planner 110 can inform the line of road planner 100 through interface 120 that the second scheduled train will be ready before the first train so that the line of road planner 100 can switch the sequence of the departure of the trains. Alternately, the line of road planner 100 can communicate to the yard planner 110 that the first scheduled train is more critical due to an operating constraint and thus the sequence of departure will remain the same even though the second train is ready for departure before the first train. [0034] In another embodiment of the present application, a model of the yard terminal can be created to assist in the prediction of the movement of the railcars through the yard in lieu of a separate planner for the yard. Such a model can estimate when the yard is available to accept and depart trains, based on the current an planned dynamic movement of the trains form and to the line of road. The model may include terminal capacity, yard capacity, inbound yard dwell, outbound yard train dwell, default yard or track resource allocation. Capacity may be mathematically modeled as one or more queues and individual track resources may be aggregated into a single track or queue for modeling. A mathematical model of the terminal provides an estimate of the capacity of the yard which can then be used to adjust the line of road plan, without the cost and complexity of a detailed terminal planner and without determining the actual terminal activities. [0035] While preferred embodiments of the present invention have been described, it is understood that the embodiments described are illustrative only and the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalence, many variations and modifications naturally occurring to those of skill in the art from a perusal hereof.

A scheduling system and method for moving plural objects through a multipath system described as a freight railway scheduling system. The scheduling system utilizes a resource scheduler to minimize resource exception while at the same time minimizing the global costs associated with the solution. The achievable movement plan can be used to assist in the control of, or to automatically control, the movement of trains through the system. Similar movement planners exist for moving trains in yards or terminals. Coordination is achieved and system efficiency improved by interfacing the line of road and yard planners.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority from provisional application Ser. No. 61/129,978, filed Aug. 4, 2008. FIELD OF THE INVENTION [0002] This invention relates to battery pack mechanical design. More specifically, the invention relates to suppression of thermal runaway in multiple-cell battery packs through the use of a hydrated hydrogel disposed in thermal contact with cells of the battery to absorb the thermal energy released from an overheated battery cell. BACKGROUND OF THE INVENTION [0003] The battery industry is continually expanding to meet the increasing energy needs of the portable equipment, transportation, and communication markets. Lithium-ion is becoming the industry standard battery chemistry due to its high energy density, sealed design and high availability in world markets. [0004] Lithium-ion batteries are produced in a number of variations; the most popular lithium-ion batteries, which have the highest energy density, use a cobalt or nickel-cobalt oxide anode. These batteries have the disadvantage of having the ability to create their own internal supply of oxygen when overheated. More specifically, oxygen is liberated from the oxide material of the anode at elevated temperatures, which can occur due to a variety of causes, such as an internal short circuit, overcharging, or other cause. Since both oxygen and fuel are both internally available to the cells, a fire can start within a single battery cell, and can be difficult to extinguish with conventional methods. In some cases the fire will continue until all the flammable materials in the battery have been exhausted. [0005] The liberated oxygen combined with the flammable electrolyte has resulted in some well-publicized battery fires. One fire of note was the 2006 fire in a laptop computer containing lithium-ion cells manufactured by Sony. This resulted in a recall of battery packs by Sony reportedly costing the company approximately US $429 million. Sony later determined that the fire was caused by metal shavings that were inadvertently encased in the cell during the manufacturing process. A shaving had pierced the battery separator, resulting in an internal short. The short heated the battery separator, causing it to melt, thus compromising the electrical insulation between the positive and negative electrodes. This further short circuit caused severe internal heating of the cell to the point where it vented hot gas and internal cell materials. However, as has been found in many fires involving lithium-ion battery packs, the event did not stop after the venting of the first cell. This is because the defective cell was able to heat an adjoining cell to the point where the adjoining cell also began to vent, and so on; as occurred in the Sony fire, the process can continue until all the cells in the pack have completed the combustion process. This phenomenon is commonly referred to in the industry as “thermal runaway”. [0006] Product liability related to thermal runaway is arguably the most prevalent issue facing manufacturers of lithium-ion battery packs. A solution to this problem would be a significant advance in lithium-ion battery marketability and would be applicable as well to future battery chemistries with a similar challenge. Moreover, conventional battery technology, such as lead-acid, has experienced its own thermal runaway incidents and could possibly benefit from use of a suppression method as in lithium-ion battery packs. [0007] One approach being investigated by Gi-Heon Kim et al at the National Renewable Energy Laboratory (NREL) was presented in NREL document NREL/PR-540-42544. In this approach a “phase-change material” (“PCM”) was used to absorb the energy released from a venting cell, thus preventing thermal runaway. The PCM used was a graphite “sponge” material acting as a carrier and heat diffuser; this graphite sponge was loaded with paraffin wax acting as the phase change material. Thus, when the material was heated by a failed cell, the paraffin wax was melted; the heat required to melt the wax, i.e., change its phase from solid to liquid, was thus effectively absorbed, preventing thermal runaway. The disadvantage of this approach is that the PCM is relatively expensive to manufacture and comprises materials (graphite and paraffin) that are themselves flammable. Further, the graphite/paraffin combination does not provide as much latent heat absorption capacity as would be desired, such that a relatively large quantity of the material must be provided to ensure adequate heat absorption. [0008] Patents relevant to the subject matter of the invention include the following: [0009] U.S. Pat. No. 3,537,907 to Wilson shows disposing individual battery cells in recesses formed in an extruded aluminum heat sink. The heat sink has an electrically insulative outer layer, typically aluminum oxide. [0010] U.S. Pat. No. 5,158,841 to Mennicke et al shows a high-temperature battery (typical operating temperature of 350° C.) in which the spaces between individual cells are filled by a loose material, e.g., quartz sand or granular aluminum oxide, through which a coolant may flow. Heating elements may also be provided. Metal foil bags may be provided as coolant conduits. [0011] Longardner et al U.S. Pat. No. 5,449,571 is directed primarily to providing PCMs in convenient packaging for receiving typical storage batteries for vehicular purposes. Longardner teaches use of the PCMs for control of the temperature of essentially conventional storage batteries; for example, the PCM can absorb excess heat from the battery, e.g., as generated during charging. Longardner also lists a wide range of PCMs at cols. 3-4, including water (at col. 3, line 61), and mentions that gelled PCMs are shown in U.S. Pat. No. 4,585,572 to Lane et al. The Lane patent discusses use of hydrated salts in a gel as PCMs for heat storage purposes, e.g., at col. 3, line 43-col. 4, line 2. Longardner also refers at col. 2 to UK patent application 2 125 156 to Rowbotham, which discloses placing PCMs in sealed bags in battery electrolyte or separator plates, and for other automotive uses. The PCMs can be used for a variety of heating purposes. [0012] U.S. Pat. No. 6,468,689 to Hallaj et al shows in the preferred embodiment using a PCM, typically wax, around the cells of an Li-ion battery pack to absorb heat released during discharge, and also discloses releasing the absorbed heat to heat the cell after discharge, and then discharging the cell at an elevated temperature; this is apparently to take place passively, that is, without specific control elements, since none are shown. The preferred materials undergo phase change at temperatures between about 30 and 60° C.; see col. 4, lines 18-22. [0013] U.S. Pat. No. 6,942,944 to Al-Hallaj et al is a continuation in part of the above and adds the idea of disposing the PCM in a matrix of a “containment lattice member” of, e.g., an aluminum foam. [0014] Maleki et al U.S. Pat. No. 6,797,427 shows surrounding the cells, or groups of cells, of an Li-ion battery with a sleeve of a material that acts as an insulator at low temperatures and as a conductor at higher temperatures, so that the temperature of a given battery can be controlled to remain close to optimum over a wide range of ambient temperatures. The sleeve is to comprise “an aluminum filled thermally conductive phase change material” (claim 3). [0015] U.S. Pat. No. 7,019,490 to Sato shows filling the space between Li-ion cells and a battery case with a heat-conductive adhesive, gel filler, gel sheet, or rubber to promote heat transfer to the outside of the case. [0016] Yahnker et al U.S. Pat. No. 7,270,910 shows improvements in battery packs for cordless power tools. Numerous possibilities are discussed in detail, including providing a mini-refrigerator in the battery pack. The discussion of FIGS. 11-13 at col. 11 of the patent shows several schemes for incorporating PCMs. These may include providing a “gel tube” comprising a plastic sheet containing a gel solution, which may comprise a fluid such as water with “micro phase-change crystals” 25-50 microns in size suspended therein; these may comprise a material such as paraffin wax encapsulated in a thermoplastic. As the battery is heated, heat is transferred to the wax; when the melting temperature of the wax is reached it begins to melt. The temperature of the phase-change material stays constant until the material has completely changed phase, so that the temperature of the battery pack is stabilized during this period. Yahnker et al application 2008/0003491 is a divisional of the '910 patent. [0017] Straubel et al patent application 2007/0218353 discloses a method of inhibiting thermal runaway by potting the lower portions of vertically-extending cells in a heat-conductive solid material which may include a PCM (see paragraph 0020) so that heat released by, for example, a single defective one of the cells is absorbed by all of the others, rather than only by the adjoining cells, so as to limit the temperature rise of the non-defective cells and reduce the chance of thermal runaway. [0018] Thus, although the art discussed teaches the use of hydrated materials and other PCMs in water for absorption of heat, and while Straubel teaches reduction of thermal runaway in multiple-cell battery assemblies by use of PCMs, the art does not appear to suggest that water might itself be useful as a PCM for prevention of battery thermal runaway per se. SUMMARY OF THE INVENTION [0019] The present invention provides a novel method for reduction of the probability of thermal runaway and thus fire in battery packs. The components that are required in order to practice the invention are simple, low in cost, and relatively easy to mass manufacture. [0020] According to the present invention, a thermal suppression element comprising a phase change material (PCM) comprising a hydrated hydrogel-forming polymer (or simply “hydrogel”) is disposed in the battery pack in thermal contact with the cells of the pack. The hydrogel used in the preferred environment is a lightly cross linked, partially neutralized polyacrylic acid commonly referred to as “superabsorbent polymer” or SAP. The acrylic or acrylic derivative polymer may be crosslinked by a polyamine crosslinking agent. This material is capable of absorbing a very large quantity of water, which is retained in gel form, having viscosity comparable to a hand cream or gelled medication. [0021] Typically, the hydrated hydrogel of the thermal suppression element will be retained in a pouch or other container adapted to fit closely between the cells of the battery pack. As the water is retained in the gel, it is not dispersed if the container is melted, torn, or ruptured, and therefore retains its heat-absorptive qualities should a cell vent, melt, or rupture. Further, the gel of the thermal suppression element in the pouch conforms to the shape of the cells, rather than pooling at the bottom of the container, as would liquid water. In the event a cell overheats, the water retained in the gel is heated and may be fully or partially vaporized, absorbing the thermal energy released by the cell, and preventing thermal runaway. [0022] Use of water as a PCM has numerous advantages, especially in the context of preventing thermal runaway per se, as opposed to simply serving as a heat-absorptive medium. Firstly, as compared to, for example, waxes or paraffins used in the prior art, water exhibits higher specific heat, such that it is capable of absorbing more heat per unit mass than such materials without phase change. Moreover, the amount of heating required to cause phase change in water, that is, from liquid to gas, is much higher than that required to melt wax; that is, it requires much more heat to cause water to undergo phase change from liquid to gas than to melt wax. Further, water is not flammable; waxes and the like can catch fire, contrary to the goal of preventing thermal runaway. Further, even when prepared as a gel, water is much less expensive than waxes and the like. BRIEF DESCRIPTION OF THE DRAWINGS [0023] The invention will be better understood if reference is made to the accompanying drawings, in which: [0024] FIG. 1 shows a perspective view of one embodiment of a thermal suppression element according to the invention, showing a container for the hydrogel material; [0025] FIG. 2 illustrates the manner in which the container of FIG. 1 can be assembled in good thermal contact with the cells of a battery pack; [0026] FIG. 3 shows a view comparable to FIG. 1 of a presently preferred embodiment of the thermal suppression element of the invention, showing a different package for the hydrogel material; and [0027] FIG. 4 shows a view comparable to FIG. 2 of the manner in which a number of the FIG. 3 thermal suppression elements can be assembled in a multi-cell battery pack. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0028] As summarized above, according to the invention a thermal suppression element comprises a quantity of water stored as a hydrogel in a pouch in good thermal contact with the cells of a battery pack. If one or more cells overheat, the water will be heated by direct contact with the outer surface of the cell; if the cell ruptures, the water will also be heated by absorption of the heat of the gases released by the cell. If heated sufficiently, the water will at least partially vaporize, thus absorbing an amount of heat per molecule vaporized equal to the latent heat of vaporization. Absorption of heat by the process of change of phase of a material, in this case change of phase of water from liquid to gaseous phase, can be referred to as phase change material (PCM) energy absorption. [0029] Referring to FIG. 1 , in a first preferred embodiment a thermal suppression element 1 comprising a liquid-tight pouch containing a hydrated hydrogel material is constructed by folding and heat-sealing a suitable plastic film. Heat-seal seams are placed in optimum positions to fabricate a package having dimensions suited to the application. Before all seams are closed the pouch is filled with a hydrated hydrogel-forming polymer (hydrogel). The final package is liquid-tight and flexible such that it may conform to the voids at the interface between cell groups. [0030] FIG. 2 shows an endwise view of a portion of a battery pack comprising six individual cylindrical battery cells 10 . In this example, the six cells 10 are assembled as two 3-cell groups; typically the three cells of each group will be assembled to circuit boards 12 comprising suitable connection, monitoring, and protection circuitry (not shown). As illustrated, the cell groups are assembled so as to confine the thermal suppression element 1 between the cells of the groups, such that the suppression element is in good thermal contact with each of the cells 10 , whereby it can effectively absorb and safely dissipate a substantial portion of any heat released from the cells. As illustrated, passages for cooling air (in normal circumstances) or gases released by a venting cell are provided between the cells 10 , circuit boards 12 , and thermal suppression elements 1 . Should hot gas be released by a defective cell, it is cooled by contact with the hydrated hydrogel in the container, substantially reducing the chance of fire. [0031] As noted above, the flexible film pouch of FIG. 1 has the advantage of readily conforming to the cells when assembled therebetween, but it is also within the invention to contain the hydrogel material in a comparatively rigid container, e.g. a molded plastic container shaped to likewise closely conform to the cells and be in good heat transfer relation therewith. As above, the water contained by the thermal suppression elements of the invention may also be heated by hot gases and other materials released from a cell that ruptures, thus further absorbing heat and reducing the chance of thermal runaway. [0032] FIGS. 3 and 4 show a presently preferred form of the pouch containing the hydrogel material according to the invention. More specifically, the pouch 1 of FIG. 1 is made using the technique known in the art as a “pillow-seal” construction, wherein a sheet of material is first folded at the sides 3 and opposed edges are then heat-bonded to one another to form a longitudinal seam 4 . One end seam 5 is then formed; the pouch is then filled, and the opposed end seam 5 closed, sealing the pouch 1 . This is a well-established method of forming such a pouch. However, where the end seams 5 intersect the longitudinal seam 4 the seal may be imperfect, leading to leaks, due to the fact that four layers of plastic must be bonded to one another where the central seam 4 intersects the end seams 5 . [0033] As shown by FIG. 3 , in the presently preferred embodiment the pouch 26 of the thermal suppression element 18 is formed using the “folding table” technique. In this construction, a flat sheet of material is first folded to form a closed edge 20 , and the opposed juxtaposed edges are heat sealed at 22 . The pouch 26 is then filled with the preferred hydrogel material, and the fourth side sealed at 24 . [0034] A third alternative construction of the pouch (not shown) involves the sealing of two separate sheets of film material to one another along four sides; the FIG. 3 construction is preferred for use in the battery pack construction of FIG. 4 because in the third construction the fourth seam (that is, replacing the folded-over, closed edge 20 of the FIG. 3 construction) is difficult to fit into the battery pack while providing adequate thermal contact between the pouch in the vicinity of the fourth seam and the adjoining cells. [0035] FIG. 4 shows the preferred thermal suppression elements 18 of FIG. 3 assembled between a plurality of cells 10 connected to a circuit board 12 . Circuitry (not shown) for monitoring and protecting the cells of a complete battery pack may be as shown in commonly-assigned U.S. Pat. No. 7,553,583, and preferred constructional techniques for battery packs that can desirably employ the thermal runaway suppression technique of the invention are shown in commonly-assigned U.S. Pat. No. 7,304,453, both incorporated herein by this reference. However, the utility of the present invention is not limited to battery packs conforming to the disclosures of either of these patents. [0036] As shown in FIG. 4 , thermal suppression elements 18 comprising pouches 26 filled with the desired hydrogel material 28 , as illustrated by partial cross-sections of two of the pouches 26 , are disposed between opposed columns of cells 10 , such that the cells 10 are in good thermal contact with the material of the pouch, as illustrated. Conveniently, the seam 24 joining the opposed members of the film so as to close the fourth side of each pouch 18 can be disposed to fit closely around one of the cells 10 , as shown, while the folded-over edge 20 fits neatly between adjoining cells 10 . [0037] As the cells 10 are in good thermal contact with the pouches 18 , if one of the cells overheats, the hydrogel material of the pouch(es) in contact with the cell absorbs the excess heat. To some extent the hydrogel material will transfer some of this heat to other cells, as suggested by, for example, the Straubel et al patent application 2007/0218353 discussed above, and to that extent provision of the pouches filled with hydrogel material according to the invention will tend to equalize the temperature of the various cells contacting a single pouch. Similarly, the thermal mass of the hydrogel will provide heat-absorptive capability, so that if all the cells are heated during charging, their average temperature will be lower than if the hydrogel were not present. [0038] However, as noted above, the main objective of provision of the hydrogel-filled pouches 18 according to the invention is to substantially limit or completely prevent thermal runaway, by providing sufficient thermal mass to absorb the heat released by a cell that is essentially on fire. As mentioned above, use of water as a phase-change material is important in provision of this degree of heat absorption. Water as mentioned has a relatively high specific heat, that is, somewhat more heat (4.18 kJ/(kg.° K)) is required to warm a given amount of water to a given degree than for wax (3.4 kJ/(kg.° K)), for example). Hence a given amount of water can absorb somewhat more heat than an equal mass of wax. More particularly, because according to the invention the water comprised by the hydrogel must be heated from ambient temperature, typically 20° C., to its boiling point of 100° C. before phase change, i.e., vaporization, takes place, far more total heat absorptive capacity is provided than is required to, for example, melt an equivalent amount of wax, which melts at 60° C. [0039] More specifically, the amount of energy required to melt paraffin wax is 195 kJ/jg, while that required to vaporize water is 2260 kJ/kg; accordingly, use of water in lieu of wax provides more than ten times the heat absorptive capability for equal weight of the PCM used before phase change takes place. [0040] Testing of the preferred thermal runaway suppression elements (TSE) according to the invention has been carried out and shows the efficacy of the invention in prevention of thermal runaway. In testing, a 50-watt heater was placed in direct contact with the metal shell of a common 18650 Li-ion cell, and left there for 45 minutes to simulate a dead internal short. Where the TSE was not present the battery was destroyed; where the TSE according to FIG. 3 (and as further described below) was in thermal contact with the cell, the cell remained functional. In the latter case the pouch of the TSE bulged somewhat, indicating partial vaporization, as some of the water evidently underwent phase change, but the pouch retained its structural integrity and did not leak. [0041] The hydrogel used in the preferred environment is a lightly cross linked, partially neutralized polyacrylic acid, commonly referred to as a “superabsorbent polymer” or SAP. A suitable material is marketed as Luquasorb 1161 by BASF Corporation. In this material, an acrylic or acrylic derivative polymer is crosslinked by a polyamine crosslinking agent. Two of the most common types of SAP are sodium and potassium polyacrylate. Both of these types have an extremely high ratio of absorbed water weight to SAP material weight, typically exceeding 200:1. The water content is preferably selected such that the water is fully captured by the SAP material but no more, such that free water does not easily spill out of the pouch of the thermal suppression element if it is inadvertently punctured or torn. Further, because the water is captured by the gel, it does not tend to pool at the lowest part of the pouch but remains dispersed throughout, in contact with each of the cells. Distilled water is preferably used to hydrate the hydrogel, in order to maximize the absorption ratio of water to the SAP material, and to minimize the electrical conductivity of the hydrogel if it escapes its pouch; this reduces the possibility of electrolytic corrosion of battery pack components. To further minimize corrosion of the battery components if the SAP material escapes, a corrosion inhibitor may be included in the SAP hydrogel formulation. Preferably vacuum is applied to the last-sealed seam of the pouch after the hydrogel is placed therein, to eliminate air as much as possible. [0042] In the preferred embodiment, the film of which the pouch of the thermal suppression element of the invention is fabricated may be a laminate including a metal film layer, typically aluminum, with one or more polymer film layers provided on either side of the aluminum film, to allow heat-sealing of the film members to fabricate the pouch. The metal layer provides a vapor barrier to prevent drying out of the hydrogel over long periods of time. A preferred film material is well-known in the art as FR2175-B; this is available from a variety of vendors, and is described (using terminology common in the art) as comprising successive layers of 90 gauge oriented polypropylene, 15 pound polyethylene, 0.000285″ aluminum foil, and 40 pound low density polyethylene film. This material exhibits very low vapor permeability, rendering the thermal runaway suppression elements according to the invention capable of preventing thermal runaway over long periods, and is easily bonded using conventional techniques and equipment. [0043] To improve containment of the hydrogel in the event of a tear in the pouch, the gel may be integrated into a fabric material. The hydrogel-filled fabric material would then be put in a sealed pouch or other container. The fabric helps contain the hydrogel if there is a tear in the pouch. Luquafleece® by BASF Corporation is a suitable fabric material for this purpose. However, as of the filing of this application this alternative is not preferred as the fabric material consumes space better occupied by additional hydrogel material. [0044] As noted above, a number of variations on the container that could be employed are within the scope of the invention. An injection molded or extruded plastic container could be constructed to properly conform to the spaces between cells. The plastic film pouch of the preferred embodiment could be made in various shapes and sizes to accommodate different battery pack geometries. [0045] The number of thermal suppression elements placed in a battery pack according to the invention may vary as required to suppress thermal runaway. For example, a heavily insulated battery pack may have very little inherent capability for dissipation of heat and will require comparatively more thermal suppression material to prevent thermal runaway. Similarly, cells that contain more potential thermal energy will require more suppression material than those containing less. [0046] It should be noted that the thermal suppression elements according to the invention also effectively smooth the peak temperatures reached by battery cells in pulsed-power applications by the provision of sensible heat storage in the SAP hydrogel. In application such as hybrid electric cars, where the batteries are called upon to deliver or absorb substantial amounts of energy at high rates, this may be a useful characteristic. More specifically, the cells in contact with the thermal suppression elements heat the hydrogel during cell power pulses. Under normal circumstances, the degree of heating is below the vaporization point of the hydrogel, and therefore its heat absorption qualities are less than if it were vaporized. Nonetheless, the overall effect of providing the hydrogel and thus adding effective sensible heat storage capacity is to reduce the peak temperature reached by the cells in the battery and thereby increase their service lifetime. [0047] While several preferred embodiments of the invention have been disclosed in detail, the invention is not to be limited thereby, but only by the following claims.

Thermal runaway in battery packs is suppressed by inserting packages of hydrated hydrogel at physical interfaces between groups of one or more cells. The hydrogel acts to diffuse and absorb thermal energy released by the cells in the event of a cell failure. During extreme overheating of a battery cell, the water stored by the hydrogel will undergo phase change, that is, begin to vaporize, thus absorbing large amounts of thermal energy and preventing thermal runaway.

FIELD OF THE INVENTION The present invention relates to methods and arrangements in a multi-antenna radio communication system, in particular to methods and arrangements for improved multiple HARQ transmission in such systems. BACKGROUND OF THE INVENTION Much research has been performed during the last years on using multiple transmit and receive antennas (MIMO) for delivering high data rates over wireless channels. Different multi-antenna methods exploit the different properties of radio channels in order to leverage one or more of the array-, diversity-, and spatial-multiplexing gains. Spatial multiplexing, for instance, may increase the peak data rates and the spectral efficiency of a multi-antenna system. Several well-known transmitter and receiver architectures have been proposed to extract the promised multiplexing gains. One example is the Vertical Bell Labs Space Time Architecture (V-BLAST). Furthermore, a horizontal MIMO structure in which each one of the encoded streams are modulated and transmitted over different transmit antennas, known as Per Antenna Rate Control (PARC), attracts more and more attentions due to good performance. In PARC, the coding rate and the modulation of the stream transmitted from each antenna is controlled based on channel quality information that is, e.g., sent to the transmitter by the receiver. Depending on channel conditions, the transmitter might decide to use a subset of the transmit antennas only. This scheme is known as Selective Per-Antenna Rate Control (S-PARC). Hybrid ARQ (HARQ) is a way to achieve reliable data delivery in a data communication system. HARQ allows combining features of a pure Forward Error Control (FEC) scheme and a pure Automatic Repeat reQuest (ARQ) scheme. Error correction and error detection functions are performed along with ACK/NACK feedback signaling. HARQ techniques have been adopted by several wireless standardization bodies, for example 3GPP and 3GPP2. HARQ can improve throughput performance, compensate for link adaptation errors, and provide a finer granularity in the rates effectively pushed through the channel. Upon detecting a transmission failure, e.g. by cyclic redundancy check (CRC), the receiver sends a request to the transmitter for retransmission. Several efforts have focused on HARQ transmission in MIMO systems, e.g. for so called MIMO multiple ARQ (MMRQ) providing an efficient combination of MIMO and HARQ structure that yields more than 30% gain in link throughput in a MIMO system using per-antenna encoders (more specifically to have one ARQ process per stream) as described, e.g., in the document “Multiple ARQ processes for MIMO systems” by H. Zheng, A. Lozano, M. Haleem published in EURASIP Journal on Applied Signal Processing, 2004.05, p. 772-782. HARQ transmission schemes in MIMO systems include, e.g., MIMO single ARQ (MSARQ) and MIMO multiple ARQ (MMARQ). With MSARQ, HARQ simply attaches a single CRC to the radio packet with a CRC encompassing the data radiated from the various transmit antennas. With MMARQ, multiple ARQ processes are employed in the MIMO channel, i.e. a CRC symbol is appended to each sub-stream. These MIMO-HARQ schemes, however, provide an indiscriminate service for all type of radio packets, i.e. they do not consider the characteristic of the radio packets. This is disadvantageous as usually different types of radio packets can have different priorities to transmit on the shared transmission channel. In addition, the first transmission and each retransmission attempt in HARQ might experience different channel qualities. To reach a good diversity gain in HARQ, either IR or CC, the transmission decision should be optimized or adaptive to the instant channel quality. Here the transmission decision includes both the antenna selection and the stream-wise selection for each transmission attempt. SUMMARY OF THE INVENTION It has thus been observed to be a problem that HARQ transmission schemes, as known in the art, only can consider the fact whether or not a transmission attempt has been successful. It is therefore an object of the present invention to provide methods and arrangements for an improved HARQ retransmission scheme, in particular for MIMO systems. Basically, it is the main idea of the present invention to provide a HARQ retransmission scheme that considers the reception quality for already performed transmissions of a data packet when selecting a resource allocation for necessary re-transmissions. Resource allocation for retransmissions is based on a pre-defined metric indicating a quality of the reception of the previous transmission attempts in form of a probability measure for a successful decoding of said data packet. Such a metric can be derived from a quality measure derived in the receiver unit, e.g. a CQI or CSI-based value, or an appropriate measure of the mutual information, e.g. the accumulated conditional mutual information (ACMI). A further criterion can be the priority of the data packet to be sent. It is an advantage of the present invention to provide an antenna stream selection scheme that improves multiple HARQ transmission in MIMO systems achieving improvements by introducing antenna selection based on a criterion, e.g. priority classes or ACMI, that is compatible with existing multi-stream HARQ transmission for MIMO systems and available for different access systems, e.g. OFDM-, TDMA-, or CDMA-based systems. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a transmitter unit and a receiver unit wherein the present invention is located. FIG. 2 illustrates an antenna (stream) selection structure for multiple HARQ transmission at the transmitter site. FIG. 3 illustrates a structure for receiving streams at the receiver site. FIG. 4 illustrates a flowchart of the present invention. DESCRIPTION OF THE INVENTION The present invention refers to supporting of an antenna (or stream) selection mechanism, in particular suitable for a multi-antenna system, i.e. providing at least multiple antennas 13 at the site of the transmitter unit 11 adapted for multi-stream transmissions 14 , in which the resource allocation (in terms of frequency-, time-, or code-resources) and the antenna selection order at the site of a transmitter unit 11 for re-transmission of data packets is based on a quality metric derived from received data packets at the site of the receiver unit 12 and, possibly, on further criterions (e.g. a priority) indicating the significance of the received data packets. The metric is to provide an information measure that indicates with what probability it is possible to decode a certain data packet that has been already received once or, possibly, after one or several retransmissions. An arrangement 15 located in or attached to the receiver unit 12 is adapted to derive said metric and provide a feedback information element 16 to the transmitter unit 11 . From this information the transmitter unit 11 can conclude the necessary resource need, depending on the applied transmission technique, for an additional retransmission for which it is predicted that the receiver unit 12 can successfully decode the data packet. The present invention is further about the necessary signaling of feedback information from the receiver unit to the transmitter unit and, in case of a possible reordering of streams for the retransmission, also from the transmitter unit to the receiver unit. The receiver unit 12 and, correspondingly, the transmitter unit 11 can within the scope of the present invention be regarded to be part of a fixed base station or a mobile user equipment. The present invention is applicable for various transmission techniques, e.g. OFDM-, TDMA-, and CDMA-based communication systems. There are various possibilities of defining an appropriate metric as described above that can be used to provide an improved feedback information measure to a transmission unit for HARQ-retransmissions. Hereby, an appropriate information measure contains information that allows a conclusion on the actually received content from, e.g., the transmission channel properties or receiver capabilities. Examples of possible metrics include thus, e.g., channel quality information (CQI), channel state information (CSI), or a mutual information measure like the ACMI. The CQI for instance can provide a measure of the signal to interference ratio measured for a data stream or part of such stream consisting of a plurality of symbols whereby the SNR can refer to each symbol or a number of symbols. The ACMI denotes the mutual information from several attempts of soft combining. For example, the ACMI for a chase combining (CC) scheme for a packet flow after a number F of transmission attempts may be estimated by ACMI F = C ⁡ ( ∑ f = 1 F ⁢ SNR Af f ) . When applying an incremental redundancy (IR) soft combining scheme the ACMI for a packet flow after a number F of transmission attempts may be estimated by ACMI F = ∑ f = 1 F ⁢ C ⁡ ( SNR Af f ) . SNR Af f denotes the signal-to-noise ratio through a selected antenna Af for the f th -transmission and C(SNR) denotes a mapping function of SNR to information or throughput. Such functions can for instance be stored in form of tables. Examples for a mapping can be found, e.g., in the document “A fading-insensitive performance metric for a unified link quality model” by Lei Wan, Shiauhe Tsai, Magnus Almgren, published in IEEE Wireless Communications and Network Conference (WCNC) 2006 , Las Vegas, USA, 2006. When assuming a data packet for which the transmitter unit already has performed F transmission attempts and where an extra retransmission is required, the antenna (or stream) Aj is selected that results in an estimated value for the mutual information measure ACMI F+1 that provides the closest approximation to an estimated mutual information threshold indicated by a desired or required probability to successfully decode the data packet. For a chase combining scheme the ACMI F+1 may be estimated by ACMI F + 1 = C ⁡ ( ∑ f = 1 F ⁢ SNR Af f + SNR Aj F + 1 ) and for incremental redundancy by ACMI F + 1 = ∑ f = 1 F ⁢ C ⁡ ( SNR Af f ) + C ⁡ ( SNR Aj F + 1 ) , where SNR Aj F+1 is the forecasted SNR for the next retransmission of the packet flow by antenna Aj. The threshold could be defined, e.g., as a maximum mutual information threshold that is required for its decoding. FIG. 4 shows a flowchart illustrating the method according to the present invention. The method starts after an indication 41 of the HARQ-algorithm that a received data packet needs to be retransmitted, which will be necessary if this data packet has been received in such a way that it is not possible to decode it. While the HARQ-algorithm according to the state of the art only indicates that a data packet needs to be re-sent, the method according to the present invention now specifies more details how a data packet should be retransmitted. These details indicate inter alia necessary transmission resources and priorities. The next step determines 42 a quality metric for the data packet. This can be done by applying one or more of, e.g., the metrics defined above. The derived metric should in any case indicate how well, or to which degree, a data packet has already been received. This indication is then provided 45 as a feedback information to the transmitter unit that is responsible for the retransmission of the data packet. Here there are several conceivable alternatives: According to a first alternative, the method provides 45 the metric for determining the necessary resource allocation in the transmitter unit or, according to a second alternative, the method already derives 43 an estimate of the metric if a certain one of the transmission antennas A j is used for the retransmission. Finally, it is also possible that the method provides 44 an indication of a suggested resource allocation in response to the derived metric. Instead of providing the calculated metric it is also possible to provide the parameters that are necessary to calculate the metric. The final decision about resource allocation, antenna (stream) selection and prioritization is normally made in the transmitter unit. Thus, the present invention also implies the step that a transmitter unit informs the receiver unit in case of retransmissions with a changed antenna configuration compared to the original or previous transmission and the receiver unit is capable to detect and apply such information. FIG. 2 shows a part of a transmitter unit 20 including a selection structure for multiple HARQ transmissions in a MIMO-system. Multiple HARQ flows on a space- or stream-level can be provided by PARC or S-PARC schemes for MIMO systems. At the transmitter, by applying a per-antenna encoding and appending 22 a CRC-field to each flow, it becomes possible that several separate HARQ processes can be provided and transmitted through different antennas or streams. Antenna or stream selection 23 is used to map different (re)transmissions to different antennas (streams) based on a selection criterion 24 , 29 . In said figure, data packets for transmission are considered in form of a flow of segmented Layer 2 packet data units (PDUs) with attached checksum (CRC). The antenna selection unit 23 determines the antenna (stream) combination to be used for sending said data packets. This determination can be based on several criterions provided by a unit 24 including information about the data packets to be sent, e.g. the traffic type or a priority indication, but also, in particular for retransmissions, based on a feedback information 29 regarding the reception quality of a previous transmission, e.g. by means of the metric according to the present invention which has been calculated from the ACMI, the CQI or CSI or any other feedback measure. From this information the antenna selection unit 23 decides by which antenna(s) or stream(s) a flow is transmitted. The stream is then forwarded to a channel encoding unit 25 (with or without interleaver), a rate matching unit 26 (e.g. performed by puncturing or repetition), and a data modulation and spreading unit 27 . Finally, a unit 28 is intended to map each stream to one or several resource blocks and antennas. In case of an OFDM system, “resource block” denotes the sub-carrier resource blocks while, for CDMA systems, “resource block” denotes a code resource or for a TDMA system a time slot. At the receiver 30 , a first unit 31 is intended to decode each sub-stream whereby the associated CRC can be used to validate the content. In case of interference cancellation and HARQ packet combining procedures the receiver can decode a sub-stream and use its associated CRC to validate the content. If this sub-stream carries a retransmission packet but contains one or more uncorrectable errors, a combining unit 32 can combine the soft symbols of the packet with those of previous transmission(s) to extract the information data. The receiver then performs interference cancellation to remove the interference due to this sub-stream. The received data packet can then be forwarded 33 for further processing by higher layer units. In case an additional retransmission is necessary, a unit 34 can derive the appropriate feedback information according to the present invention as described above in conjunction with FIG. 4 and provide this information back to the transmitter unit. The present invention implies the need for an appropriate signaling with regard to the retransmission feedback information on the one hand and, as forward transmission, in order to support the antenna selection mechanism. As already indicated above, the present invention allows for several alternatives for providing retransmission feedback information, either by providing those parameters that are necessary to derive the metric or by providing the derived metric itself. Also, it might be conceivable to provide an indication of a recommended resource allocation for the retransmission. At the transmitter site, signaling of the transmitter unit in conjunction with the present invention shall assure that a receiver knows which packets are transmitted through which streams even for packet retransmissions. Channel quality information (e.g. CQI, CSI, or ACMI) is required to report the quality of each of the possible transmitted streams. The ACMI estimation can be set in the transmitter or receiver. If set in the transmitter, the receiver informs the transmitter on the CQI-values of the possible used streams to facilitate antenna selection in the transmitter. If the ACMI estimation is set in the receiver, it is the receiver that decides which transmission that is carried by which stream and then to inform the transmitter to adjust its usage of streams. This signaling could be done, e.g., together with ACK/NACK signaling. Multiple acknowledgment (NACK/ACK) indications are required to be sent back to the transmitter. After receiving these acknowledgements, the transmitter sends fresh packets from the transmit antennas that have been successfully acknowledged and retransmits the sub-streams that have been negatively acknowledged through their associated transmit antennas. Hence, the HARQ operations at different transmit antennas are independent of each other. If the ACMI estimation is set in the transmitter, the CQI or CSI is required to report for each of the possible transmitted streams. When assuming that there are M streams under consideration there is an M-fold increase in CQI, CSI, or ACMI information that is required to be reported. Optionally, a priority indication can be applied as one additional criterion for antenna (or stream-wise) selection. This can imply that, for instance, high priority packets will be given a priority to select the antenna or stream that should be used for transmission. For example, retransmission may have higher priority than the 1 st transmission, and the last IP segment radio packet may have higher priority than other types of segment radio packet. The ACMI or any other quality feedback metric can be used for antenna selection among radio packets with the same priority.

The present invention relates to methods and arrangements in a multi-antenna radio communication system, in particular to methods and arrangements for improved multiple HARQ transmission in such systems. While HARQ transmission schemes, as known in the art, only can consider the fact whether or not a transmission attempt has been successful the present invention provides a HARQ retransmission scheme that considers the reception quality for already performed transmissions of a same data packet when selecting a resource allocation for necessary re-transmissions. Resource allocation for retransmissions is based on a pre-defined metric indicating a quality of the reception of the previous transmission attempts. Such a metric can be derived from a quality measure derived in the receiver unit, e.g. a CQI or CSI-based value, or an appropriate measure of the mutual information, e.g. the accumulated conditional mutual information (ACMI).

RELATED APPLICATION [0001] This application is a continuation of U.S. patent application Ser. No. 10/211,944, filed on Aug. 1, 2002, which is a continuation of International Patent Application No. PCT/US01/04476 filed on Feb. 12, 2001 under the Patent Cooperation Treaty (PCT), which was published by the International Bureau in English on Aug. 16, 2001, which designates the United States and which claims benefit of U.S. Provisional Application No. 60/181,938 filed on Feb. 11, 2000. FIELD OF THE INVENTION [0002] Vegetable protein-based adhesive compositions and methods for preparing them are provided. The adhesives are prepared by copolymerizing hydrolyzed vegetable protein that has been functionalized with methylol groups and one or more comonomers also having methylol functional groups. Preferred hydrolyzed vegetable proteins include hydrolyzed soy protein obtained from soy meal. BACKGROUND OF THE INVENTION [0003] Ancient adhesive raw material choices were limited. Starch, blood and collagen extracts from animal bones, and hides were the early sources. Somewhat later, the range of raw materials used in adhesives was expanded to include milk protein and fish extracts. These early starch and protein-based adhesives suffered from a number of drawbacks. They generally lacked durability, and were able to maintain long-term strength only as long as they were kept dry. [0004] Adhesives based on soyflour first came into general use during World War I. To obtain suitable soyflour for use in these early adhesives, the oil had to be extracted from soybean meal and the meal ground into extremely fine flour. These early soybean adhesives suffered from the same drawbacks as other early protein-based adhesives, and their use was strictly limited to interior applications. [0005] In the 1920's, phenol-formaldehyde and urea-formaldehyde resins were first developed. Phenol-formaldehyde and urea-formaldehyde resins are exterior-durable, in contrast to the protein-based adhesives, such as the early soyflour adhesives, in use at that time. The phenol-formaldehyde and urea-formaldehyde resins, also referred to as “thermoset” polymeric adhesives, suffered from a number of drawbacks, the foremost of which was the high cost of raw materials. These adhesives did, however, demonstrate superior durability when compared to the early protein-based adhesives. World War II perpetuated the rapid development of these adhesives for water and weather resistant applications, such as exterior applications. The low cost protein-based adhesives continued to be used in interior applications, however. [0006] After World War II, the petrochemical industry invested vast sums of money in research and development to create and expand new markets for petrochemicals. Within several years, the costly raw materials used in manufacturing thermoset adhesives became inexpensive bulk commodity chemicals. In the 1960's, the price of petrochemical-based adhesives had become so low that they displaced protein adhesives out of their markets. SUMMARY OF THE INVENTION [0007] Over the past several years, the cost of petrochemicals used as raw materials in thermoset resins have risen to the point where protein-based adhesives can compete in the same markets that are today enjoyed by the thermoset adhesives. A protein-based adhesive that combines the cost benefits of proteins as a raw material with the superior exterior durability characteristics of thermoset adhesives is therefore desirable. In accordance with the preferred embodiments, a low cost soybean-based adhesive suitable for exterior uses is provided. The adhesive is prepared by copolymerizing hydrolyzed soybean protein and selected co-monomers currently used in thermoset adhesives. [0008] In a first embodiment, an adhesive is provided, the adhesive including a copolymer of a vegetable protein having a plurality of methylol groups and at least one co-monomer having a plurality of methylol groups. [0009] In one aspect of the first embodiment, the vegetable protein comprises soy protein, for example hydrolyzed soy protein. [0010] In another aspect of the first embodiment, a soymeal having a protein content of from about 40 wt. % to about 50 wt. % and an oil content of less than about 11 wt. % includes the soy protein. [0011] In a further aspect of the first embodiment, the co-monomer is a methylol compound including dimethylol phenol, dimethylol urea, tetramethylol ketone, and trimethylol melamine. [0012] In yet another aspect of the first embodiment, a composite board includes the adhesive. [0013] In a second embodiment, a method of preparing an adhesive is provided, the method including the steps of providing a denatured vegetable protein; functionalizing the denatured vegetable protein with a plurality of methylol groups, thereby yielding a methylolated vegetable protein; providing a co-monomer having a plurality of methylol groups; preparing a solution comprising the methylolated vegetable protein and the co-monomer; maintaining the solution at an elevated temperature, whereby the methylolated vegetable protein and the co-monomer polymerize; and recovering an adhesive, the adhesive comprising the polymerization product of the methylolated vegetable protein and the co-monomer. [0014] In one aspect of the second embodiment, the hydrolyzed vegetable protein comprises a hydrolyzed soy protein. [0015] In another aspect of the second embodiment, the step of providing a hydrolyzed vegetable protein includes the steps of providing a plurality of soybeans, the soybeans comprising a soy protein; processing the soybeans into soymeal; and hydrolyzing the soy protein. The step of processing the soybeans into soymeal may include subjecting the soybeans to a process selected from the group consisting of solvent extraction, extrusion, and expansion/expelling; and recovering a soymeal. [0016] In a further aspect of the second embodiment, the step of denaturing the vegetable protein includes the steps of forming an aqueous, alkaline solution of the vegetable protein; and maintaining the solution at an elevated temperature, thereby producing a denatured vegetable protein. The step of forming an aqueous, alkaline solution of the vegetable protein may include forming an aqueous, alkaline solution of the vegetable protein and a phase transfer catalyst, such as polyethylene glycol, a quaternary ammonium compound, and tris(dioxa-3,6-heptyl)amine. The step of forming an aqueous, alkaline solution of the vegetable protein may also include forming an aqueous, alkaline solution of the vegetable protein and an antioxidant, such as tertiary butylhydroquinone and butylated hydroxyanisone. The step of forming an aqueous, alkaline solution of the vegetable protein may include forming an aqueous, alkaline solution of the vegetable protein and urea. [0017] In yet another aspect of the second embodiment, the step of functionalizing the denatured vegetable protein with a plurality of methylol groups, thereby yielding a methylolated vegetable protein includes the reacting the denatured vegetable protein with formaldehyde in a basic solution at elevated temperature, thereby yielding a methylolated soy protein. [0018] In yet a further aspect of the second embodiment, the step of providing a co-monomer having a plurality of methylol groups comprising the steps of providing a compound selected from the group consisting of phenol, urea, acetone, and melamine; and reacting the compound with formaldehyde in a basic solution at elevated temperature, thereby yielding a co-monomer having a plurality of methylol groups. The step of functionalizing the denatured vegetable protein with a plurality of methylol groups and the step of providing a co-monomer having a plurality of methylol groups may be conducted in a single reaction mixture. [0019] In yet another aspect of the second embodiment, the step of maintaining the solution at an elevated temperature, whereby the methylolated vegetable protein and the co-monomer polymerize includes maintaining the solution at an elevated temperature, whereby a methylol group of the vegetable protein and a methylol group of the co-monomer undergo a condensation reaction such that a water molecule is liberated and a reactive ether linkage is formed, the ether linkage reacting such that a formaldehyde group is liberated and a methylene bridge is formed. The step of maintaining the solution at an elevated temperature may also include maintaining the solution at an elevated temperature, whereby a hydroxyl group of the vegetable protein and a methylol group of the co-monomer undergo a condensation reaction such that a water molecule is liberated and a reactive ether linkage is formed, the ether linkage reacting such that a formaldehyde group is liberated and a methylene bridge is formed. The step of maintaining the solution at an elevated temperature may also include maintaining the solution at an elevated temperature, whereby an amine group of the vegetable protein and a methylol group of the co-monomer undergo a condensation reaction such that a water molecule is liberated and a methylene bridge is formed. [0020] In yet another aspect of the second embodiment, the method further includes the step of providing a solid substance; mixing the solid substance with the solution; and recovering a composite. The composite may include a fiberboard. The solid substance may include an agricultural material, such as corn stalk fiber, poplar fiber, wood chips, and straw. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0021] The following description and examples illustrate a preferred embodiment of the present invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a preferred embodiment should not be deemed to limit the scope of the present invention. [0022] The preferred embodiments relate to the copolymerization of soybean protein and methylolated compounds. Suitable compounds include, for example, methylolated urea, melamine, phenol, and acetone. The adhesives may be prepared using the methylolated compounds as raw materials, or else suitable compounds may be methylolated via reaction with formaldehyde as a step in the process of preparing the adhesive. [0023] In the past, the value of crosslinking formaldehyde with a protein was to insolubilize and resinify the protein. Formaldehyde also improves the solubility and stability of the protein in the dissolved state. The adhesives of the preferred embodiments are based on a soluble protein. The soluble protein is reacted with formaldehyde to form methylol derivatives. Methylolated proteins react with other methylolated compounds to form thermoset resins. These thermoset resins are then crosslinked to form exterior resins. [0024] Urea and melamine, along with formaldehyde, are the basic reagents that form the common amino resins. Three reactions are involved in the formation of the resins: methylolation, condensation, and methylene bridge formation. In the methylolation reaction, formaldehyde reacts with urea and melamine in the presence of an acid or base catalyst to add a methylol group to each of the molecule's primary amine groups. The secondary and primary amine groups of proteins also undergo methylolation with formaldehyde in the presence of an acid or base catalyst. In the condensation reaction, water is liberated to form a polymer chain or network. This is referred to as methylene bridge formation: [0000] RNH—CH 2 OH+H 2 NR→RNH—CH 2 NH—R+H 2 O [0025] The condensation and methylene bridge formation steps result in the polymerization and crosslinking of the methylolated molecules. The Soy Protein [0026] One of the components of the adhesives of preferred embodiments is a protein obtained from soybeans. The soybean plant belongs to the legume family. The protein content of the soybeans is typically about 40 wt. %. After the hulls and the oil are removed from the soybean (“defatting”), the resulting product, referred to as defatted soymeal, typically has a protein content of about 40 wt. % to about 50 wt. %. [0027] Soy meal is typically obtained from soybeans by separating all or a portion of the oil from the soybean. Soy meal is typically obtained from soybeans by solvent extraction, extrusion, and expelling/expansion methods. [0028] In solvent extraction methods, soybeans entering the processing plant are screened to remove damaged beans and foreign materials, and are then comminuted into flakes. The soybean oil is removed from the flakes by extraction with a solvent, such as hexane. Suitable extraction apparatus are well known in the art and may include, for example, countercurrent extractors. After the defatted flakes leave the extractor, any residual solvent is removed by heat and vacuum. Soymeal produced by solvent extraction methods contains essentially no oil and about 40 to 50 wt. % protein. [0029] In extrusion methods, after the soybeans are screened and flaked, the flakes are heated under conditions of pressure and moisture in an extrusion apparatus. Suitable extrusion apparatus are well known in the art, including, for example, horizontal screw extrusion devices. Soymeal from extrusion methods typically contains about 5-9% oil and about 40-48% protein. In preferred embodiments, soybeans defatted in an extrusion process are preferred because of their lower cost and because the small amount of oil left in the soymeal improves the moisture resistance of the adhesive. However, soybeans defatted in a solvent extraction process or any other process are also suitable for use in the adhesives of the preferred embodiments. [0030] Another method for producing soymeal is the expansion/expelling method. This method has gained in popularity over other methods because of the quality of the byproducts produced, as well as the freedom from environmental hazards associated with solvent extraction methods. In the expansion/expelling method, the raw soybeans are fed through a series of augers, screeners, and controlled rate feeders into the expanders. The internal expander chambers and grinders create extreme temperature and pressure conditions, typically from about 375 to about 425 psi. The oil cells of the bean are ruptured as the product, in slurry form, exits the expander and the pressure drops down to atmospheric pressure. The high frictional temperature, typically between about 150° C. to about 177° C., cooks the meal and oil, yielding a high quality product. About half of the 12% moisture present in the raw soybean is released as steam as the slurry exits the expander. The water and steam mix inside the expander, keeping the slurry fluid as well as aiding in the cooking process. The hot soymeal slurry is then fed to a continuous oil expeller. The meal is squeezed under pressure and the free oil is expelled. The oil and the meal are then separated and recovered. The soymeal exits the press as both a dry powder and chunks, which can be milled with a hammermill to an acceptable bulk density and consistency. The product may then be passed through a cooler where heat is extracted. The final expanded/expelled soymeal typically contains about 7 to 11% oil and about 42 to 46% protein, on a dry matter basis. Solvent extraction of the meal produces a product typically containing less than about 0.1% oil and about 48% protein. [0031] To produce a soymeal suitable for use in the adhesives of the preferred embodiments, it is preferably ground into fine flour. Typically, the dry extracted meal is ground so that substantially all of the flour passes through a 65 mesh screen. [0032] In preferred embodiments, the soymeal contains about 44 wt. % or more protein. However, soymeals with lower protein content may also be suitable in certain embodiments. Soymeal having various oil contents may be used in preferred embodiments. [0033] The soy protein in soymeal is a globular protein consisting of a polypeptide chain made up of amino acids as monomeric units. Proteins typically contain 50 to 1000 amino acids residues per polypeptide chain. The amino acids are joined by peptide bonds between the alpha-carboxyl groups and the alpha-amino groups of adjacent amino acids, wherein the alpha-amino group of the first amino acid residue of the polypeptide chain is free. The majority of amino acid residues in proteins tend to be hydrophobic, and as such are not very water-soluble. The molecular structures of soy proteins contain a hydrophobic region that is enclosed within a hydrophilic region, so that many of the polar groups are unavailable. The globular shape of proteins in aqueous solution is a consequence of the fact that the proteins expose as small a surface as possible to the aqueous solvent so as to minimize unfavorable interactions with the water and maximize favorable interactions of the amino acid residues with each other. The conformation of the protein is maintained by disulfide bonds and by non-covalent forces, such as van der Waals interactions, hydrogen bonds, and electrostatic interactions. [0034] When a protein is treated with a denaturant, the conformation is lost because the denaturant interferes with the forces maintaining the configuration. The result is that more polar groups of the protein are available for reaction. In preparing the adhesives of the preferred embodiments, the soy protein is first denatured. Any suitable denaturants as are well known in the art, for example, organic solvents, detergents, concentrated urea solutions, or even heat, may be used to denature the soy protein. However, in preferred embodiments, alkali or acid treatments at elevated temperatures are used to denature the protein by breaking hydrogen bonds, that is, by hydrolyzing the protein. [0035] The denaturing of the protein is preferably performed as a separate step. However, in certain embodiments it may be conducted by adding urea or another denaturant to the soy protein methylolation reaction mixture. In preferred embodiments, a phase transfer catalyst is added to the denaturing reaction mixture. The phase transfer catalyst serves to enhance the rate of reaction occurring in a two phase organic-aqueous system by catalyzing the transfer of water soluble reactants across the interface to the organic phase. Suitable phase transfer catalysts include polyethylene glycol, quaternary ammonium compounds, and the like. In a preferred embodiment, the phase transfer catalyst is tris(dioxa-3,6-heptyl)amine, commonly referred to as Thanamine or TDA-1 (available from Rhodia, Inc. of Cranbury, N.J.). In various embodiments, it is preferred to add a component to the reaction mixture that enhances the solubility of the protein, thereby facilitating the denaturing reaction. Certain antioxidants, including tertiary-butylhydroquinone (TBHQ) and butylated hydroxyanisone (BHA), are observed to increase the solubility of soy protein, however, other suitable solubility enhancers may also be used. [0036] Because of its low cost, it is preferred to use soymeal as the source of vegetable protein in the adhesives of the preferred embodiments. However, it is to be understood that the adhesives of the preferred embodiments are not limited to only those prepared from soy protein. Other sources of vegetable protein are also suitable for use in preferred embodiments. Non-limiting examples of other sources of vegetable protein include, for example, nuts, seeds, grains, and legumes. These sources include, but are not limited to, peanuts, almonds, brazil nuts, cashews, walnuts, pecans, hazel nuts, macadamia nuts, sunflower seeds, pumpkin seeds, corn, peas, wheat, and the like. Additional and/or different processing steps from those used to prepare the soymeal of preferred embodiments may be used in refining and separating the protein from the raw product of these other sources, as will be appreciated by one skilled in the art. The processed proteins, after being subjected to a denaturing step, may be methylolated according to the methods illustrated below for soymeal, and may be reacted with methylolated co-monomers as illustrated below for soymeal to produce adhesives acceptable for various applications. The Co-Monomer(s) [0037] To prepare the adhesives of the preferred embodiments, the soy protein and one or more co-monomers are polymerized. In order for the polymerization reaction to occur, the soy protein is first subjected to methylolation. If the co-monomers do not already contain methylol groups, they too are subjected to methylolation prior to the polymerization reaction. Preferred co-monomers include any molecule containing methylol groups, or any molecule which may undergo methylolation, for example, via reaction with formaldehyde. Non-limiting examples of suitable methylol-containing molecules include dimethylol urea, trimethylol melamine, tetramethylol ketone and dimethylol phenol. Nonlimiting examples of suitable co-monomers capable of undergoing methylolation via reaction with formaldehyde include urea, melamine, and phenol. In preferred embodiments, the co-monomer is capable of substitution by two, three, four or more methylol groups. Generally, co-monomers having more methylol substituents are more reactive than co-monomers having fewer methylol substituents. [0038] A single co-monomer or mixtures of two or more co-monomers may be used in the adhesives of the preferred embodiments. A preferred co-monomer mixture contains methylol ketone and methylol phenol. Different co-monomers possess different properties and characteristics. By combining two or more co-monomers having different characteristics, an adhesive having properties that render it especially suitable for a particular application may be obtained. The Methylolation Reaction [0039] The first step in the preparation of the adhesives of the preferred embodiment involves methylolation (also referred to as hydroxymethylation) of the denatured protein's polypeptide chain, along with methylolation of any of the co-monomers that do not already incorporate methylol groups. Any suitable reaction may be used to functionalize the protein or co-monomer with hydroxymethyl groups. In preferred embodiments, however, the methylolation reaction proceeds by reacting the protein or co-monomer with formaldehyde in the presence of an acid or base catalyst. The methylolation of the protein and the co-monomer(s) may be conducted simultaneously in the same reaction mixture, or may be conducted separately for each component. Methylolation of proteins and amines such as urea and melamine typically involves substitution of primary and/or secondary aminic hydrogens by hydroxymethyl groups. When the co-monomer is phenol, the methylolation reaction involves replacing the phenol molecule's two ortho hydrogens or an ortho hydrogen and a para hydrogen with hydroxymethyl groups. The reaction yields a mixture of 2,4-dimethylol phenol and 2,6-dimethylol phenol. When the co-monomer is acetone, a methyl hydrogen is replaced by a hydroxymethyl group. Typical methylolation reactions for a polypeptide and selected co-monomers of the preferred embodiments are illustrated below. [0000] [0040] The methylolated co-monomers of preferred embodiments are commercially available and may be purchased from selected resin manufacturers. Alternatively, co-monomers that are not methylolated or are only partially methylolated may be subjected to a methylolation step as part of the process of preparing the adhesives of preferred embodiments. When methylolating the co-monomer starting material, it is preferred to conduct the methylolation at a pH of about 8.4 to about 10.5, however, in certain embodiments a higher or lower pH may be suitable. The methylolation reaction is preferably conducted at a temperature of about 32° C. to about 75° C. Higher or lower temperatures may also be suitable, depending upon the reactivity of the compound to be methylolated or other factors. Reaction times of from about 20 minutes to two hours are typically sufficient to ensure complete methylolation. However, as will be appreciated by one skilled in the art, the methylolation reaction may proceed more rapidly or more slowly in certain embodiments, resulting in a shorter or longer reaction time. [0041] Methylolation of the polypeptide chains of the soy protein and the non-methylolated or partially-methylolated co-monomer may preferably be conducted at the same time in the same reaction mixture, so as to provide a simpler process. However, the methylolation of the polypeptide chains of the soy protein may be conducted separately from that of the non-methylolated or partially-methylolated co-monomer in certain embodiments. Copolymerization [0042] After methylolation of the soy protein and, in certain embodiments, the co-monomer, the next step in the preparation of the adhesives of the preferred embodiments involves polymerization (also referred to as resinification or curing) of the protein and co-monomer molecules. One of the reactions in the polymerization process involves the condensation of a methylol group with an amine group to liberate water and form a methylene bridge. Another reaction in this process involves condensation of two methylol groups to yield an unstable ether linkage, which undergoes a reaction to liberate formaldehyde, thereby forming a methylene bridge. This free formaldehyde then reacts with the reactive amine groups of the polypeptide to form additional methylol groups. Methylol groups are also capable of condensing with non-methylolated hydroxyl groups to form unstable ether linkages. [0043] Because each protein molecule typically contains methylol groups and groups that are reactive to methylol groups, significant crosslinking occurs. In preferred embodiments, the reaction is conducted at elevated temperature. Preferred temperatures are typically between 65° C. and 110° C. However, higher or lower temperatures may be preferred in certain embodiments, as will be appreciated by one skilled in the art. Typical condensation reactions between a methylolated protein and either a 2,6-methylolated urea or 2,6-dimethylol phenol are depicted below. [0000] [0044] As stated above, the ether linkages formed in certain of the condensation reactions are not stable. At elevated temperatures or under acidic conditions, formaldehyde is spontaneously liberated from the linked molecules to yield a methylene bridge. The released formaldehyde may then participate in further methylolation reactions. The formation of the methylene bridge in a methylolated protein molecule coupled to either methylolated urea or methylolated phenol is depicted below. [0000] Use of Adhesives in Composition Boards [0045] The adhesives of preferred embodiments are suitable for use in a variety of applications, including applications where conventional resin adhesives are typically used. One particularly preferred application for the adhesives of the preferred embodiments is in the manufacture of composition boards. Composition boards prepared using the soy protein based adhesives of the preferred embodiments possess acceptable physical properties as set forth in industry standards. [0046] The physical properties of composition boards are measured according to standards set forth by the American Society for Testing and Materials in “Standards and Methods of Evaluating the Properties of Wood-Base Fiber and Particle Panel Materials.” Two of the more significant physical properties of finished composition board include modulus of elasticity and modulus of rupture under static bending conditions. Modulus of elasticity is a measure of the stiffness of the sample and is reported in pounds per square inch (psi) or Pascals (Pa). Modulus of rupture is regarded as the breaking strength of the sample and is reported in psi or Pa. In composition boards, both of these properties are determined parallel to the face of the panel. The acceptable range for modulus of rupture will vary depending upon the grade of composition board. For board having a thickness of one half inch, the modulus of rupture is preferably within the range of 1000 psi to 3000 psi, however for certain embodiments values outside of this range may also be acceptable. [0047] Another property, tensile strength perpendicular to the surface, also referred to as internal bond, provides a measure of how well the board is glued together. The value is reported in psi or Pa. The acceptable range for internal will vary depending upon the grade of composition board. The internal bond is preferably from about 35 psi to about 100 psi for board having a thickness of one half inch. However, for certain embodiments, values outside of this range may also be acceptable. This test is currently not used extensively, but should become more important as the composition board industry moves towards greater production of boards for use in structural applications. [0048] Water resistance is evaluated by submerging a sample of board in water at room temperature for 24 hours and by submerging another sample in boiling water for 2 hours. Typically, only the 24 hour test is conducted, unless the panel is to be used in structural or construction applications. In the water resistance test, the thickness of the board is measured before and after submerging the sample in water. The thickness swell is then measured as the percent increase in thickness. Acceptable water resistance is typically indicated by a thickness swell of less than about 15%, however for certain embodiments, values outside of this range may also be acceptable. EXAMPLES Adhesives Prepared from Untreated Soymeal [0049] Adhesives were prepared from untreated soymeal and resins including urea and formaldehyde, melamine, and phenol formaldehyde. Example 1 Soymeal with Urea and Formaldehyde [0050] [0000] Component Wt. (g) Soymeal (44% protein, 5-6% oil) 200 Sodium hydroxide 16 Water 536 Polyethylene glycol 400 (phase transfer catalyst) 6 Urea 60 Aqueous solution of 37 wt. % formaldehyde and 7 wt. % MeOH 138 Sodium silicate 20 Total 976 [0051] The sodium hydroxide, water and polyethylene glycol were mixed together and heated to 80° C. 100 grams of the untreated soybean meal were added to the mixture, then approximately ten minutes later the remaining soybean meal was added. The soybean meal underwent hydrolysis under the basic reaction conditions. An antifoam agent and formaldehyde solution were added, after which the temperature of the mixture was approximately 62° C. The temperature was raised to 90° C. over the course of approximately 30 minutes, and maintained at 90° C. for approximately 20 minutes. The mixture was allowed to cool, and the pH was adjusted to 8.5 with formic acid. The percentage of solids in the mixture was 36.4%. The sodium silicate was added to the mixture, which raised the pH to 9.9. The mixture was subjected to vacuum distillation at an elevated temperature of approximately 65-67° C. After vacuum distillation, the resin had a pH of 9.8, a viscosity of 1227 cps (measured at 20 rpm, spindle #64, using a Brookfield-Model DV-E viscometer), and a solids content of 50.5%. [0052] The resin was allowed to cure by placing it in an oven at a temperature of 110° C. for 2 hours, then a 5 g sample of the cured resin was placed in 80 g of boiling water for 0.5 hours. In contrast to typical urea resins which tend to break down in boiling water and emit free formaldehyde to the atmosphere, the soymeal-urea resin was insoluble in the boiling water. Example 2 Soymeal with Melamine [0053] [0000] Component Wt. (g) Soymeal (44% protein, 5-6% oil) 200 Sodium hydroxide 16 Water 536 Polyethylene glycol 400 (phase transfer catalyst) 6 Melamine 39 Aqueous solution of 37 wt. % formaldehyde and 7 wt. % MeOH 76 Total 873 [0054] The sodium hydroxide, water and polyethylene glycol were mixed together and heated to 80° C. 100 grams of the soybean meal was added to the mixture, eight minutes later an additional 50 grams of soybean meal was added, then four minutes later the remaining soybean meal was added. During the soybean meal addition, the mixture was heated to 105° C. The mixture was then cooled to 80° C., the melamine was added, and then the formaldehyde solution was added. The temperature of the mixture was maintained at 80° C. for approximately 5 minutes, then allowed to cool to 60° C. over the course of approximately 1.25 hours. The mixture was subjected to vacuum distillation at a temperature of approximately 60° C. After vacuum distillation, the resin had a pH of 12.0, a viscosity of 3180 cps (measured at 20 rpm, spindle #64, using a Brookfield-Model DV-E viscometer), and a solids content of 49.3%. [0055] The resin was cured as in Example 1 and a 5 g sample was placed in 80 g boiling water for 0.5 hours. The soymeal-melamine resin was insoluble in the boiling water. Example 3 Soymeal with Phenol and Formaldehyde [0056] [0000] Component Wt. (g) Soymeal (44% protein, 5-6% oil) 200 Sodium hydroxide 16 Water 536 Polyethylene glycol 460 (phase transfer catalyst) 6 Phenol (90 wt. % aq. soln.) 94 Aqueous solution of 37 wt. % formaldehyde and 7 wt. % MeOH 175 Total 1027 [0057] The sodium hydroxide, water and polyethylene glycol were mixed together and heated to 80° C. 80 grams of the soybean meal were added to the mixture, an additional 40 grams of soybean meal were added, and then the remaining soybean meal was added. During the soybean meal addition, the mixture was heated to 100° C. The phenol and the formaldehyde solutions were added, after which the temperature of the mixture dropped to approximately 90-93° C. The solids content of the mixture was 33.6%. The mixture was subjected to vacuum distillation for approximately 80 minutes, yielding a mixture with solids content of 51.4%. [0058] The resin was cured as in Example 1 and a 5 g sample was placed in 80 g boiling water for 0.5 hours. The soymeal-phenol formaldehyde resin was insoluble in the boiling water. [0059] Preparation of Soy Protein Hydrolysate [0060] Soy protein hydrolysate, rather than untreated soymeal, was used as a starting material in various adhesives of the preferred embodiments. The soybean meal was produced by the expelling/expansion method. The protein content of soybean meal produced by this method typically is from about 40 to about 48%, and the oil content from about 5 to about 11%. The presence of the oil increases the water resistance of the resulting soybean protein adhesive. Example 4 Hydrolyzed Soymeal 0.33 wt. % Urea [0061] [0000] Component Wt. (g) Soymeal (44% protein, 8.9% oil) 400 Sodium hydroxide 64 (50 wt. % aq. soln., Van Waters & Rogers, Inc., Kirkwood, WA) Water 1040 Tris(dioxa-3,6-heptyl)amine 0.04 (phase transfer catalyst, Rhodia, Inc., Cranbury, NJ) Tertiary-butylhydroquinone (TBHQ) 0.04 (antioxidant, Aldrich, Milwaukee, WI) Butylated hydroxyanisone (BHA) 0.04 (antioxidant, Aldrich, Milwaukee, WI) Urea 5 Total 1509.1 [0062] The components were mixed together and heated to 140° C. for 2 hours to form a solution. The pH of the resulting solution was 10.3 and the viscosity was 650 cps (measured at 20 rpm, spindle #2, using a Brookfield-Model DV-E viscometer). Example 5 Hydrolyzed Soymeal 2.0 wt. % Urea [0063] [0000] Component Wt. (g) Soymeal (44 wt. % protein, 8.9 wt. % oil) 400 Sodium hydroxide (50 wt. % aq. soln.) 64 Water 1040 Tris(dioxa-3,6-heptyl)amine (phase transfer catalyst) 0.04 Tertiary-butylhydroquinone (TBHQ) (antioxidant) 0.04 Butylated hydroxyanisone (BHA) (antioxidant) 0.04 Urea 30 Total 1534.1 [0064] The components were mixed together and heated to 85° C. for 30 minutes to form a solution. The pH of the resulting solution was 10.3. [0065] The antioxidants are observed to increase the solubility of the soymeal in solution. Urea is observed to decrease the water holding capacity of the protein and to decrease the viscosity of the solution. At increased urea concentrations, temperature and reaction time of the hydrolysis reaction may be decreased without significantly affecting the physical characteristics of the hydrolyzed soymeal. [0066] The length of the polypeptide chains in the protein hydrosylate after hydrolysis of the soymeal is a function of pH, temperature, and time. Generally, the higher the pH or temperature, or the greater the length of time to which the soybean meal is subjected to hydrolysis, the shorter the polypeptide chain length. Typically, solutions including shorter, lower molecular weight polypeptide chains will have a lower viscosity. Depending upon the application in which the adhesive is used, lower or higher molecular weight polypeptide chains are preferred. For example, different molecular weights may be preferred for different panel grades of composite boards. Example 6 Adhesive from Protein Hydrosylate and Tetramethylol Ketone [0067] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1419.3 Tetramethylol ketone 227.4 (approx. 3% free formaldehyde) (marketed as AF-3600 by Dynachem, Georgetown, IL) Total 1646.7 [0068] The components were mixed together, and then the pH was adjusted to 9.43 with a 50 wt. % aqueous solution of NaOH. The mixture was heated to approximately 95-100° C. and allowed to reflux for 17 minutes. The mixture was then cooled to 45° C. and the pH adjusted to 8.5 with glacial acetic acid, after which it was vacuum distilled to 50 wt. % solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 7 Protein Hydrosylate with Methylol Phenol Resin [0069] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1152 Dimethylol phenol 506.9 (marketed as Phenalloy 2175 by Dynachem, Georgetown, IL) Total 1658.6 [0070] The components were mixed together, and then the pH was adjusted to 10 with a 50 wt. % aqueous solution of NaOH. The mixture was heated to approximately 95-100° C. and allowed to reflux for approximately half an hour. The mixture was cooled and the pH adjusted with acid. The mixture was then vacuum distilled to 40 wt. % solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 8 Protein Hydrosylate with Methylol Urea Resin [0071] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1200 Dimethylol urea 486 (Dynachem, Georgetown, IL) Tetramethylol ketone 57.3 Total 1743.3 [0072] The components were mixed together, and then the pH was adjusted to 9.43 with a 50% solution of aqueous NaOH. The mixture was heated to approximately 95-100° C. and allowed to reflux for 66 minutes. The mixture was cooled and the pH adjusted with acid. The mixture was then vacuum distilled to 40 wt. % solids. The mixture was then vacuum distilled to 40 wt. % solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 9 Protein Hydrosylate with Methylol Melamine Resin [0073] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1152 Trimethylolmelamine 814.6 (Dynachem, Georgetown, IL) Total 1966.6 [0074] The components were mixed together, and then the pH was adjusted to 10.5 with a 50% solution of aqueous NaOH. The mixture was heated to approximately 95-100° C. and allowed to reflux for 67 minutes. The mixture was cooled and the pH adjusted with acid. The mixture was then vacuum distilled to 40% solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 10 Protein Hydrosylate with Methylol Ketone Resin [0075] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1300 Tetramethylol ketone 621.5 Total 1921.5 [0076] The components were mixed together, and then the pH was adjusted to 10.5 with a 50% solution of aqueous NaOH. The mixture was heated to approximately 95-100° C. and allowed to reflux for 28 minutes. The mixture was cooled and the pH adjusted with acid. The mixture was then vacuum distilled to 40% solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 11 Protein Hydrosylate with Methylol Ketone and Methylol Phenol Resin [0077] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 4) 1509 Tetramethylol ketone 227 Dimethylol phenol 142 Total 1878 [0078] The components were mixed together, and then the pH was adjusted to 10.0 with a 50% solution of aqueous NaOH. The mixture was heated to approximately 80-95° C. and allowed to reflux for 11 minutes. The mixture was cooled, the pH adjusted with acid, and then the mixture was subjected to vacuum distillation. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. Example 12 Protein Hydrosylate with Methylol Ketone Resin [0079] [0000] Component Wt. (g) Soy protein hydrosylate (prepared according to Example 2) 1300 Dimethylol urea 651 Total 1951 [0080] The components were mixed together, and then the pH was adjusted to 10.3 with a 50 wt. % solution of aqueous NaOH. The mixture was heated to approximately 100-107° C. and allowed to reflux for 28 minutes. The mixture was cooled and the pH adjusted with acid. The mixture was then vacuum distilled to 50% solids. The conditions of the vacuum distillation were 27.5 inches Hg at a temperature of 52° C. [0081] Composition Boards Containing Soy Protein Hydrosylate Adhesives [0082] Medium density fiberboard panels were prepared using various soybean based adhesives. Example 13 [0083] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (75.5 wt. %) and tetramethylol ketone (24.5 wt. %). The panel contained 8 wt. % of the resin and 1 wt. % wax (Borden Chemical, Waverly, Va.). [0084] Modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), and thickness swelling (TS) were measured for two samples of the panel. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein and tetramethylol ketone provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. Example 14 [0085] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %) and dimethylol phenol (50 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0086] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein and dimethylol phenol provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. Composite boards prepared using dimethylol phenol, a cheaper starting material than certain of the other methylol co-monomers, have the added benefit of reduced cost. Example 15 [0087] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %) and dimethylol urea (45 wt. %) and tetramethylol ketone (5 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0088] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. Composite boards prepared using urea have little water resistance, resulting in a board that will release formaldehyde when exposed to water under room temperature conditions. In contrast, boards prepared from dimethylol urea are water resistant and do not release formaldehyde. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein, dimethylol urea, and tetramethylol ketone provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. The resin is especially preferred in applications where water resistance is less important and no formaldehyde emissions are desired, such as, for example, interior applications. Example 16 [0089] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %) and trimethylol melamine (50 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0090] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein and trimethylol melamine provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. The good modulus of rupture, modulus of elasticity and water resistance make this resin preferred for surface applications. Example 17 [0091] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %) and tetramethylol ketone (50 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0092] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein and tetramethylol ketone provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. Example 18 [0093] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %) and a mixture of tetramethylol ketone (25 wt. %) and dimethylol phenol (25 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0094] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein, tetramethylol ketone, and dimethylol phenol provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. Example 19 [0095] A medium density fiberboard panel of 0.5 inch thickness was prepared from a fiber mixture containing 50 wt. % corn stalk fiber and 50 wt. % hybrid poplar fiber. The fibers were bonded with a resin comprising a copolymer of hydrolyzed soybean protein (50 wt. %, prepared as in Example 5) and tetramethylol ketone (50 wt. %). The panel contained 12 wt. % of the resin and 1 wt. % wax. [0096] Two samples of the panel were tested as in Example 13. The test results are presented in Table 1. The data demonstrate that composition boards prepared from a resin comprising a copolymer of hydrolyzed soybean protein and tetramethylol ketone provides satisfactory modulus of rupture, modulus of elasticity, internal bond, and thickness swelling, making such panels suitable for exterior use. [0000] TABLE 1 24 hr. Soak 2 hr. Boil Water Water Resin Wax Density MOR MOE IB TS Absorption TS Absorption Example Composition of Resin (wt. %) (wt. %) (lbs/ft 3 ) Sample (psi) (psi) (psi) (%) (%) (%) (%) 13 Hydrolyzed soy protein 8 1 42 a 2351 396688 36 54.72 128.35 146.01 193.37 (75.5 wt. %) and methylol b 2117 391083 32 57.05 128.89 167.69 205.28 ketone (24.5 wt. %) 14 Hydrolyzed soy protein 12 1 43 a 4350 530021 86 25.3 82.26 44.18 99.84 (50 wt. %) and dimethylol b 4250 527407 82 28.75 81.19 46.59 99.81 phenol (50 wt. %) 15 Hydrolyzed soy protein 12 1 43 a 3148 494121 47 27.28 76.29 94.87 173.77 (50 wt. %), dimethylol b 2687 459454 46 34.47 96.64 100.47 168.12 urea (25 wt. %), and tetramethylol ketone (25 wt. %) 16 Hydrolyzed soy protein 12 1 43 a 3133 431153 62 25.4 94.98 49.49 112.54 (50 wt. %) and trimethylol b 3203 452664 61 26.72 96.26 51.07 111.94 melamine (50 wt. %) 17 Hydrolyzed soy protein 12 1 43 a 4469 590098 109 13.56 48.74 38.98 91.26 (60 wt. %) and b 3957 554530 91 14.68 52.47 37.1 91.84 tetramethylol ketone (40 wt. %) 18 Hydrolyzed soy protein 12 1 43 a 3463 420766 64 21.8 82.35 31.78 91.26 (50 wt. %), tetramethylol b 3469 465969 62 19.51 ? 30.57 91.84 ketone (25 wt. %), and dimethylol phenol (50 wt. %) 19 Hydrolyzed soy protein 12 1 43 a 3300 449294 93 16.88 59.34 36.91 81.43 (50 wt. %) and b 3507 443993 62 17.11 53.09 36.33 88.27 tetramethylol ketone (50 wt. %) [0097] The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims. Each reference cited herein, including but not limited to patents and technical references, is hereby incorporated herein by reference in its entirety.

Vegetable protein-based adhesive compositions and methods for preparing them are provided. The adhesives are prepared by copolymerizing hydrolyzed vegetable protein that has been functionalized with methylol groups and one or more co-monomers also having methylol functional groups. Preferred hydrolyzed vegetable proteins include hydrolyzed soy protein obtained from soy meal.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 13/186,599, filed Jul. 20, 2011, which is a continuation of U.S. patent application Ser. No. 12/175,038, filed on Jul. 17, 2008, and issued as U.S. Pat. No. 8,007,481 on Aug. 30, 2011. The disclosures of these prior applications are hereby incorporated herein by reference in their entirety. BACKGROUND [0002] 1. Technical Field [0003] The present disclosure relates to treating an open wound, and, more specifically, relates to a wound therapy system including an improved subatmospheric pressure mechanism. [0004] 2. Description of the Related Art [0005] Wound closure involves the migration of epithelial and subcutaneous tissue adjacent the wound towards the center and away from the base of the wound until the wound closes. Unfortunately, closure is difficult with large wounds, chronic wounds or wounds that have become infected. In such wounds, a zone of stasis (i.e., an area in which localized swelling of tissue restricts the flow of blood to the tissues) forms near the surface of the wound. Without sufficient blood flow, the epithelial and subcutaneous tissues surrounding the wound not only receive diminished oxygen and nutrients, but, are also less able to successfully fight microbial infection and, thus, are less able to close the wound naturally. Such wounds have presented difficulties to medical personnel for many years. [0006] Negative pressure therapy also known as suction or vacuum therapy has been used in treating and healing wounds. Application of negative pressure, e.g. reduced or subatmospheric pressure, to a localized reservoir over a wound has been found to assist in closing the wound by promoting blood flow to the area, stimulating the formation of granulation tissue, and encouraging the migration of healthy tissue over the wound. Negative pressure may also inhibit bacterial growth by drawing fluids from the wound such as exudates, which may tend to harbor bacteria. This technique has proven particularly effective for chronic or healing-resistant wounds, and is also used for other purposes such as post-operative wound care. [0007] Generally, negative pressure therapy provides for a wound to be covered to facilitate suction at the wound area. A conduit is introduced through the wound covering to provide fluid communication to an external vacuum source. Atmospheric gas, wound exudates, or other fluids may thus be drawn from the wound area through the fluid conduit to stimulate healing of the wound. Exudates drawn from the wound area may be deposited in a collection canister or container. [0008] Subatmospheric pressure mechanisms used in wound therapy systems may include a cavity or chamber for receiving the removed exudates, a vacuum source, and a power source. The pressure mechanisms are configured to provide the suction that draws exudates from the wound. Unfortunately, conventional subatmospheric pressure mechanisms have a tendency to develop leaks. Leaks may reduce the efficiency of the system and/or create odor and wetness issues. SUMMARY [0009] Accordingly, the present disclosure relates to an improved subatmospheric pressure mechanism. A portable system for subatmospheric pressure therapy in connection with healing a surgical wound is provided. The system includes a wound dressing dimensioned for positioning relative to a wound bed of a subject, and a collection canister in fluid communication with the wound dressing. The canister may include a base defining a fluid receiving cavity and having a fluid inlet port and a vacuum port. The fluid inlet port is configured for fluid communication with a wound dressing. A cover is selectively engageable to the base, e.g., in a snap-fit manner. The cover accommodates a control unit and a vent assembly for exhausting the control unit. A seal member is interposed relative to the base and the cover and is adapted to establish and maintain a sealed relationship between these components. At least one of the fluid inlet port and the vacuum port may be configured to receive a cap. [0010] The control unit of the system may include a vacuum source and/or a power source. The vacuum port may also include a hydrophobic membrane. The vent assembly may be recessed relative to the base or cover. The system may further include a divider having a plurality of longitudinal grooves formed on an underside thereof. The divider may further include a channel fluidly communicating the plurality of longitudinal grooves with at least one of the fluid inlet port and the vacuum port. The control unit may be directly connected to the vent assembly. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: [0012] FIG. 1 is a view of a wound therapy system in accordance with the principles of the present disclosure; [0013] FIG. 2 is a side cross-sectional view of the subatmospheric pressure mechanism of the wound therapy system of FIG. 1 ; [0014] FIG. 3 is a side cross-sectional side view of the subatmospheric pressure mechanism of FIG. 2 , illustrating the housing cover separated from the housing base; [0015] FIG. 4A is an enlarged side cross-sectional view of the vent assembly of the subatmospheric pressure mechanism of FIGS. 2 and 3 ; [0016] FIG. 4B is an enlarged plan view of the vent assembly of FIG. 4A ; [0017] FIG. 5A is an enlarged side cross-sectional view of an alternate embodiment of the vent assembly of the subatmospheric pressure mechanism of FIGS. 2 and 3 ; [0018] FIG. 5B is an enlarged front view of the vent assembly of FIG. 5A ; [0019] FIG. 6 is a perspective view of another subatmospheric pressure mechanism of the present disclosure; [0020] FIG. 7 is a perspective view of another embodiment of the subatmospheric pressure mechanism; [0021] FIG. 8 is a plan view of the divider of the subatmospheric pressure mechanism of FIG. 7 ; [0022] FIG. 9 is cross-sectional end view of the divider of FIG. 8 taken along line 9 - 9 ; and; [0023] FIG. 10 is a cross-sectional view of the divider of FIG. 8 taken along line 10 - 10 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0024] The following figures illustrate embodiments of the present disclosure and are referenced to describe the embodiments depicted therein. Hereinafter, the disclosure will be described by explaining the figures wherein like reference numerals represent like parts throughout the several views. [0025] Referring initially to FIG. 1 , a wound therapy system of the present disclosure is shown generally as wound therapy system 100 . Wound therapy system 100 includes composite wound dressing 102 and subatmospheric pressure mechanism 104 in fluid communication with the wound dressing 102 through a conduit, identified schematically as reference character “c”. For a more detailed description of wound dressing 102 , including the composition and operation thereof, please refer to commonly owned U.S. patent application Ser. No. 12/047910, filed Mar. 13, 2008, the contents of which are incorporated herein by reference in their entirety. [0026] With reference now to FIGS. 2-3 , subatmospheric pressure mechanism 104 will be described in detail. Subatmospheric pressure mechanism 104 may be a portable canister adapted to be worn or carried by the subject via a strap, belt, or the like. In the alternative, pressure mechanism 104 may be a component of a non-ambulatory system. Subatmospheric pressure mechanism 104 includes housing base 110 and housing cover 120 selectively attachable to housing base 110 . Housing base 110 and/or housing cover 120 may be fabricated from substantially rigid material, or in the alternative, include a relatively flexible material. Housing base 110 defines a first cavity 111 for receiving fluid, e.g. exudates “E” from wound dressing 102 ( FIG. 1 ). Housing cover 120 defines a second cavity 121 to accommodate, e.g., a control unit for controlling operation of system 100 . The control unit may consist of vacuum source 5 150 , power source 160 , and logic software and/or processing means for controlling operation of vacuum source 150 based on various parameters and/or in connection with a treatment regimen. [0027] Housing base 110 and housing cover 120 may be adapted for releasable coupling. In one embodiment. housing base 110 includes flange 112 and notch or recess 114 . Flange 112 is configured to engage lip 122 formed in housing cover 120 . Notch 114 is configured to selectively receive a tab 126 of an extension 124 of housing cover 120 . Housing base 110 further includes a fluid inlet 116 and a suction port 118 . Fluid inlet 116 is configured to operably engage conduit “c” and may include a luer lock 112 a. Inlet 116 is preferably configured to receive cap 116 a for preventing leakage of exudates “E” and odor from first cavity 111 when housing cover 120 is separated from housing base 110 . Suction port 118 is configured to operably engage vacuum source 150 . Suction port 118 may include a hydrophobic membrane or filter 115 for preventing exudates “E” from being aspirated into vacuum source 150 . Suction port 118 may also be configured to receive cap 118 a to prevent fluid leakage during disposal of housing base 110 . [0028] With reference still to FIGS. 2 and 3 , housing cover 120 is configured for releasable engagement with housing base 110 and includes second cavity 121 for receiving vacuum source 150 and power source 160 . Vacuum source 150 and/or power source 160 may be maintained with housing cover 120 with rubber mounts (not shown) for reducing vibration within housing cover 120 . Housing cover 120 may be constructed of and/or include STYROFOAM® or other sound dampening material. Housing cover 120 may include an overlay, having lights and/or buttons (not shown) for monitoring and controlling the operation of subatmospheric pressure mechanism 104 . Housing cover 120 includes lip 122 configured to engage flange 112 of housing base 110 . An extension 124 extends from housing cover 120 opposite lip 122 and is configured for operable engagement by a user. Extension 124 includes tab 126 configured to engage notch 114 formed in housing base 110 . Extension 124 is configured to flex such that tab 126 may be selectively received within notch 114 , thereby, releasably securing housing cover 120 to housing base 110 . This snap-fit configuration may produce an audible sound when tab 126 is received within notch 114 , thereby, notifying the user that housing cover 120 and housing base 110 are securely joined together. [0029] Seal member 128 extends about housing cover 120 to form a seal between housing cover 120 and housing base 110 when housing cover 120 is selectively secured to housing base 110 . Seal member 128 may be secured to housing cover 120 in any manner, including mechanical fastening, welding, and adhesive. Alternatively, seal member 128 may extend about housing base 110 to form a seal between housing base 110 and housing cover 120 . In an alternative embodiment, seal member 128 may include two or more seal elements (not shown). Seal member 128 establishes and maintains a sealed relationship between cover 120 and housing base 110 when the components are assembled thereby preserving the integrity of the second cavity 121 within cover 120 . [0030] Housing cover 120 further includes vent assembly 130 configured to vent exhaust air from vacuum source 150 through exhaust port 130 a. Turning initially to FIGS. 4A and 4B , vent assembly 130 extends from housing cover 120 and is directly connected to vacuum source 150 ( FIG. 1 ) via tube 131 . Vent assembly 130 includes filter 132 extending across exhaust port 130 a and split ring 136 for retaining filter 132 over exhaust port 130 a . Vent assembly 130 includes groove 134 formed about exhaust port 130 a adapted to receive split ring 136 . Filter 132 is sized and dimension such that an outer portion of filter 132 folds into groove 134 and is retained therein by split ring 136 . Filter 132 may be hydrophobic in nature and/or may include charcoal or other odor absorbing material, and may prevent the passage of bacteria. Split ring 136 may be formed of plastic, metal or other suitable material. Split ring 136 may include openings 136 a configured to receive a tool for removing split ring 136 from within groove 134 . In this manner, filter 132 may be changed as necessary. [0031] Turning now to FIGS. 5A and 58 , in an alternative embodiment, vent assembly 130 ′ may be recessed in housing cover 120 . Additionally, vent assembly 130 ′ may vent exhaust air from within second cavity 121 rather than directly from vacuum source 150 via tube 131 . In this manner, heat may be dissipated from within second cavity 121 in addition to the venting of exhaust from vacuum source 150 . This configuration also provides a positive pressure on filter 132 . Filter 132 is again retained within a groove 134 ′ formed in housing 120 by split ring 136 . [0032] In operation, subatmospheric pressure mechanism 104 is adapted to draw exudates from wound dressing 102 via conduit “c”. Initially, housing cover 120 is selectively secured to housing base 110 . To secure housing cover 120 to housing base 110 , lip 122 of housing cover 120 is first received within flange 112 of housing base 110 . Housing cover 120 is then pivoted about flange 112 such that extension 124 received over housing base 110 . Housing cover 120 is pivoted until tab 126 of extension 124 is received within notch 114 . Subatmospheric pressure mechanism 104 may be configured such that receipt of tab 126 within notch 114 causes an audible sound, thereby confirming to a user that housing cover 120 has been securely received on housing base 110 . Once subatmospheric pressure mechanism 104 is assembled, conduit “c” may be fluidly coupled to fluid inlet 116 and the control unit (not shown) may be activated. Activation of vacuum source 150 creates suction within first cavity 111 that draws exudates from wound dressing 102 through conduit “c”. Exudates “E” collect in first cavity 111 of housing base 110 . Exhaust from vacuum source 150 is vented either directly or indirectly through vent assembly 130 , 130 ′, respectively. Heat may also be dissipated through vent assembly 130 ′. [0033] Upon filling of first cavity 111 , completion of treatment or other any other reason, subatmospheric pressure mechanism 104 may be deactivated and exudates “E” may be properly disposed. To disengage housing cover 120 from housing base 110 , extension 124 of housing cover 120 is flexed away from housing base 110 . In this manner, tab 126 on extension 124 is withdrawn from engagement with notch 114 formed in housing base 120 . Housing cover 120 may be pivoted away from housing base 110 until lip 122 of housing cover 120 disengages flange 112 of housing base 110 . Once housing cover 120 is separated from housing base 110 , exudates “E” may be disposed. Exudates “E” may be emptied from first cavity 111 , or alternatively, housing base 110 may be disposed of in its entirety. In the event housing base 110 is disposed, caps 116 a, 118 a may be placed in fluid inlet 116 and suction port 118 , respectively, such that housing base 110 may be transported without worry of fluid leakage or odor escaping from within cavity 111 . [0034] With reference now to FIG. 6 , a housing base of alternate embodiment of a subatmospheric pressure mechanism is shown as housing base 10 . Housing base 10 includes divider 12 for separating housing base 10 into a fluid receiving portion 10 a and an operational portion 10 b configured for receiving a control unit, including a vacuum source and power source (not shown). Divider 12 includes a fluid inlet port 13 a and a vacuum port 13 b. Divider 12 further includes a gasket 14 extending about an outer periphery of divider 12 . Gasket 14 is configured to engage vacuum source ( FIG. 2 ) in a sealed manner, thereby enabling a vacuum to be created within fluid receiving portion 10 a to draw fluid from wound dressing 102 ( FIG. 1 ). [0035] Turning now to FIG. 7 , a housing base of an alternative embodiment of the subatmospheric pressure mechanism of the present disclosure is shown generally as housing base 210 . Subatmospheric pressure mechanism 210 includes a divider 212 including a fluid inlet port 213 a and vacuum port 213 b. Divider 212 further includes a gasket 214 extending about fluid inlet port 213 a and vacuum port 213 b for engaging a vacuum source ( FIG. 2 ) in a sealed manner. By localizing gasket 214 around fluid inlet port 213 a and vacuum port 213 b the likelihood of scaling issues, such as air and fluid leaks, is reduced. Gasket 214 may be formed of gel or other suitable sealing material. One preferred gel material is a silica gel. [0036] With reference now to FIGS. 8-10 , underside 212 a of divider 212 is configured to assist in fluid collection. Divider 212 includes a plurality of longitudinal grooves 214 extending the length thereof. Channel 216 extends the width of divider 212 in alignment with fluid inlet port 213 a and vacuum port 213 b. Channel 216 fluidly communicates each of the plurality of longitudinal grooves 214 with fluid inlet port 213 a and vacuum port 213 b . Divider 212 may be integrally formed with housing base 210 , or as shown configured to be received within housing base 210 . In this manner, divider 212 is sealed within housing base 210 using a hydrophobic adhesive or other suitable bonding material (not shown). Divider 212 may further include a hydrophobic membrane 218 at least partially covering longitudinal grooves and vacuum port 213 b. Hydrophobic membrane 216 provides a fluid barrier between the fluid collection chamber and the control mechanism. Longitudinal grooves 214 provide increased surface area for air flow through hydrophobic membrane 218 . This may assist vacuum flow, e.g., in the event that a portion of the surface area becomes clogged and/or covered with exudate “E” or other fluid. [0037] Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.

A portable system for subatmospheric pressure therapy in connection with healing a surgical wound is provided. The system includes a wound dressing dimensioned for positioning relative to a wound bed of a subject, and a collection canister in fluid communication with the wound dressing. The canister includes a base defining a fluid receiving cavity and having a fluid inlet port and a vacuum port. The fluid inlet port is configured for fluid communication with a wound dressing, The system further includes a cover selectively engageable to the base, e.g., in a snap-fit manner. The cover is configured to receive a control unit and has a vent assembly for exhausting the control unit. A seal member is interposed relative to the base and the cover to establish and maintain a substantial sealed relationship between the two components when assembled.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of United States Provisional Patent Application Ser. No.: 60/423,813, entitled “Limited Contender Queue,” filed on Nov. 5, 2002 (Attorney Docket: 680-036us), which is incorporated by reference. FIELD OF THE INVENTION [0002] The present invention relates to telecommunications in general, and, more particularly, to a communications station that is transmitting information with a high access priority. BACKGROUND OF THE INVENTION [0003] [0003]FIG. 1 depicts a schematic diagram of telecommunications system 100 in the prior art, which transmits signals between communication stations 101 - 1 through 101 -P, wherein P is a positive integer, over shared-communications medium 102 . Stations 101 - 1 through 101 -P and shared-communications medium 102 constitute a local area network (LAN). [0004] A local area network is commonly used to connect computing devices (i.e., stations) in various locations (e.g., company offices, etc.) to exchange information and share resources (e.g., printers, mail servers, etc.). Transmission between the stations can occur across wires or over the air, as in a wireless local area network. Local area networks are typically governed by certain standards. IEEE 802.11 is an example of a standard that governs a wireless local area network. [0005] Stations 101 - 1 through 101 -P are computing devices capable of communicating with each other using wireless network interfaces and, together, constitute a basic service set (which is also called a “BSS”) in an 802.11-based network. A basic service set can be regarded as a building block for an 802.11-based network. Station 101 - 2 enables stations 101 - 1 through 101 -P to communicate with other communications networks outside of the BSS and is appropriately referred to as an “access point.” [0006] [0006]FIG. 2 depicts stations 201 and 202 in the prior art. They communicate with each other through dedicated transmission channels 203 and 204 . Because stations 201 and 202 communication via dedicated transmission channels 203 and 204 , stations 201 and 202 need not be concerned with sharing transmission resources. In contrast, stations 101 - 1 through 101 -P have to share the transmission medium (e.g., a cable, the airwaves, etc.) that ties them all together, namely shared-communications medium 102 , in the same manner that users need to share a telephone party line. Consequently, stations 101 - 1 through 101 -P have to follow rules (or “protocols”) that govern, among other things, when and for how long at a time they each can use shared-communications medium 102 . Stations 101 - 1 through 101 -P gain access to shared-communications medium 102 by following the established protocols of IEEE 802.11. Depending on the application, stations 101 - 1 through 101 -P can have varying degrees of success in transmitting information to each other using a shared-communications medium. SUMMARY OF THE INVENTION [0007] Simulations with many types of distributed, shared access mechanisms have shown that the scheduling order or “queue discipline” of when stations transmit is of great importance. For instance, the 802.11 Distributed Coordination Function is not a guarantee for any scheduling order, due to the random postbackoff that it defines. Long time unfairness could exist for any given CWmin and CWmax value used in the randomizing process. Examples of fair and unfair scheduling sequences for three streams of traffic are: [0008] Fair scheduling order: 1-2-3-1-2-3-1-2-3-1-2-3-1-2-3-1-etc. [0009] Unfair scheduling order: 1-1-1-2-3-1-1-1-2-3-3-3-3-3-3-etc., [0010] wherein each number (i.e., 1, 2, 3) represents traffic from a given stream of the three. [0011] Typically, the latter sequence represents shared-communications medium activity involving the three streams of message traffic. The latter sequence might also be fair over the long term, but streaming applications demand short term scheduling fairness. Otherwise, the intermediate delays would be unacceptably uneven and buffer overflows could occur. Short term scheduling fairness is crucial in keeping the delays acceptable for all streams at any time. This is particularly true for devices transmitting real-time signals, such as audio and video streams. It is crucial that the signals are crisp and uninterrupted in real-time applications. [0012] The present invention solves the problem where multiple stations seek to communicate streams (i.e., flows) with each other while maintaining fairness in scheduling. In some embodiments of the present invention, each station transmits a portion of a coordinated flow after contending for access to a shared-communications medium. After transmitting the portion, the station self-imposes a restriction interval, during which time, the station cannot contend again for the shared-communications medium to transmit the next portion of the coordinated flow. The restriction interval selected staggers the contentions of the individual stations into a scheduling order exhibiting fairness. In accordance with the illustrative embodiment, when the station is again permitted to transmit, it then waits a shortened backoff interval that ensures that the station wins contention for the channel when it needs to. [0013] The illustrative embodiment of the present invention comprises contending for access to a shared-communications medium; transmitting a first portion of a flow into the shared-communications medium, wherein the flow has a maximum length of T milliseconds; and waiting for at least T*(N−1) milliseconds before again contending for access to the shared-communications medium to transmit a second portion of the flow, wherein N is a positive integer equal to the number of coordinated flows permitted concurrently on the shared-communications medium. BRIEF DESCRIPTION OF THE DRAWINGS [0014] [0014]FIG. 1 depicts a schematic diagram of telecommunications system 100 in the prior art. [0015] [0015]FIG. 2 depicts two stations connected through dedicated transmission channels in the prior art. [0016] [0016]FIG. 3 depicts a schematic diagram of telecommunications system 300 that supports coordinated flows, in accordance with the illustrative embodiment of the present invention. [0017] [0017]FIG. 4 depicts a block diagram of the salient components of station 301 -h, for h=1 through P, in accordance with the illustrative embodiment of the present invention. [0018] [0018]FIG. 5 depicts a series of coordinated flow portions of the first embodiment of the present invention. [0019] [0019]FIG. 6 depicts competing access sequences, in accordance with the illustrative embodiment of the present invention. [0020] [0020]FIG. 7 depicts a message flow diagram of the first admission control technique, in accordance with the illustrative embodiment of the present invention. [0021] [0021]FIG. 8 depicts a message flow diagram of the second admission control technique, in accordance with the illustrative embodiment of the present invention. [0022] [0022]FIG. 9 depicts a message flow diagram of the third admission control technique, in accordance with the illustrative embodiment of the present invention. [0023] [0023]FIG. 10 depicts a message flow diagram of the second embodiment of the present invention. [0024] [0024]FIG. 11 depicts a schematic diagram of the respective coverage areas of depicted stations, in accordance with the illustrative embodiment of the present invention. [0025] [0025]FIG. 12 depicts a message flow diagram of the third embodiment of the present invention. [0026] [0026]FIG. 13 depicts a message flow diagram of the fourth embodiment of the present invention. [0027] [0027]FIG. 14 depicts an access sequence of the fifth embodiment of the present invention. [0028] [0028]FIG. 15 depicts a flowchart of the tasks performed by a station seeking to exchange a coordinated flow portion, in accordance with the illustrative embodiment of the present invention. DETAILED DESCRIPTION [0029] The following terms in the art are used in this specification, along with corresponding information taken from the IEEE 802.11(e) draft specification, which is incorporated by reference: [0030] Distributed Coordination Function (DCF)—The rules for contention-based access to the wireless medium where the same coordination function logic is active in every station. [0031] Point Coordination Function (PCF)—The rules that provide for centrally coordinated access to the wireless medium where the coordination function logic is active in only one station (i.e., the point coordinator, typically residing at the access point). [0032] Enhanced Distributed Coordination Function (EDCF)—Analogous to DCF with the added concept of different traffic classes corresponding to different priorities. [0033] Hybrid Coordination Function (HCF)—Analogous to PCF, but allows a Hybrid Coordinator to maintain the states for stations and allocate contention-free transmit opportunities intelligently. [0034] Short Interframe Space (SIFS)—A time interval between frames that is shorter than Point Coordination Function Interframe Space. [0035] Point Coordination Function Interframe Space (PIFS)—A time interval between frames that is longer than SIFS and shorter than Distributed Coordination Function Interframe Space. Also referred to as Point Interframe Space. [0036] Distributed Coordination Function Interframe Space (DIFS)—A time interval between frames that is longer than PIFS. Also referred to as Distributed Interframe Space. [0037] Arbitration Interframe Space (AIFS)—A time interval between frames used in support of the different traffic classes in the EDCF (i.e., one AIFS per traffic class). It can be equal to DIFS or it can be longer than DIFS. [0038] [0038]FIG. 3 depicts a schematic diagram of the illustrative embodiment of the present invention, telecommunications system 300 , which transmits signals between stations 301 - 1 through 301 -P, wherein P is a positive integer, over shared-communications medium 302 . Each of stations 301 - 1 through 301 -P can be a stationary, portable, or mobile type with different types in the mix. [0039] In accordance with the illustrative embodiment, telecommunications system 300 is a packet-switched network, in contrast to a circuit-switched network, as is well known to those skilled in the art. In other words, a macro data structure (e.g., a text file, a part of a voice conversation, etc.) of indefinite size is not necessarily transmitted across shared-communications medium 302 intact, but rather might be transmitted in small pieces. [0040] Each of these small pieces is encapsulated into a data structure called a “data frame,” and each data frame traverses shared-communications medium 302 independently of the other data frames. (Other types of frames also exist, such as control frames.) The intended receiver of the macro data structure collects all of the data frames as they are received, recovers the small pieces of data from each, and reassembles them into the macro data structure. [0041] Shared-communications medium 302 can be wireless or wireline. A salient characteristic of shared-communications medium 302 is that every frame transmitted on shared-communications medium 302 by any station is received or “seen” by every station on shared-communications medium 302 , regardless of whether the frame was intended for it or not. In other words, shared-communications medium 302 is effectively a broadcast medium. [0042] If shared-communications medium 302 is wireless, in whole or in part, embodiments of the present invention can use a variety of radio or optical frequencies and transmission methods. Possible radio frequency spectrum, if used, includes the Industrial, Scientific, and Medical (ISM) frequency bands in the ranges of 2.4 GHz and 5.0 GHz. Shared-communications medium 302 can be part of a wireless local area network. In the illustrative embodiments, shared-communications medium 302 constitutes an 802.11 wireless local network. After reading this specification, however, it will be clear to those skilled in the art that embodiments of the present invention can be applied to a non-802.11 network, a non-standardized network (e.g., a proprietary network, etc.), or both. [0043] It will be clear to those skilled in the art how to make and use shared-communications medium 302 . It will also be clear to those skilled in the art that shared-communications medium 302 depicted in FIG. 3 is illustrative only and that types of communications networks other than telecommunications system 300 are within the scope of the present invention. [0044] Stations 301 - 1 through 301 -P receive or generate the macro data structure and prepare it for transmission over shared-communications medium 302 . The macro data structure can represent, for example, telemetry, text, audio, video, etc. Alternatively, one or more of stations 301 - 1 through 301 -P (e.g., station 301 - 2 , etc.) can function as gateways between shared-communications medium 302 and other communications networks. In functioning as a gateway, a station exchanges the macro data structure with another communications network. [0045] [0045]FIG. 4 depicts a block diagram of the salient components of station 301 -h, for h=1 through P, in accordance with the illustrative embodiment of the present invention. Station 301 -h comprises receiver 401 , processor 402 , memory 403 , and transmitter 404 , interconnected as shown. [0046] Receiver 401 comprises the wireless or wireline or hybrid wireless and wireline interface circuitry that enables station 301 -h to sense the medium for determining if a signal is present and to receive messages from shared-communications medium 302 . When receiver 401 receives a message from shared-communications medium 302 , it passes the message to processor 402 for processing. It will be clear to those skilled in the art how to make and use receiver 401 . [0047] Processor 402 is a general-purpose or special-purpose processor that is capable of performing the functionality described below and with respect to FIGS. 5 through 15. In particular, processor 402 is capable of storing data into memory 403 , retrieving data from memory 403 , and of executing programs stored in memory 403 . It will be clear to those skilled in the art, after reading this specification, how to make and use processor 402 . [0048] Memory 403 accommodates input queues and output queues for incoming and outgoing messages (e.g., 802.11 frames, etc.), respectively. It will be clear to those skilled in the art how to make and use memory 403 . [0049] Transmitter 404 comprises the wireless or wireline or hybrid wireless and wireline interface circuitry that enables station 301 -h to transmit messages onto shared-communications medium 302 . It will be clear to those skilled in the art how to make and use transmitter 404 . [0050] Stations 301 - 1 through 301 -P need not possess identical capability. Situations involving stations with heterogeneous capabilities can occur, for example, where modern stations are added to a telecommunication system that comprises only legacy stations. Additionally, the situation can result where some, but not all, of the stations in a telecommunications system are upgraded with additional capabilities. Whatever the reason, it will be clear to those skilled in the art why telecommunications systems exist that comprise stations with heterogeneous capabilities. [0051] In accordance with the illustrative embodiment of the present invention, some of stations 301 - 1 through 301 -P are not capable of guaranteeing a particular scheduling order with regards to accessing shared-communications medium 302 . For the purposes of this specification, these stations are referred to as “legacy stations.” The example of a legacy station in the illustrative embodiment is an 802.11-capable station without enhancements that promote fairness in scheduling order. In contrast, others of stations 301 - 1 through 301 -P are capable of guaranteeing a scheduling order with regards to accessing shared-communications medium 302 . For the purposes of this specification, these stations are referred to as “upgraded stations.” The example of an upgraded station in the illustrative embodiment is a station with enhancements that promote fairness in scheduling order, either 802.11-based or proprietary. In accordance with the illustrative embodiment of the present invention, legacy stations and upgraded stations are capable of communicating with each other because the upgraded stations transmit messages that are intended for legacy stations in the format that is understood by and compatible with the legacy stations. Furthermore, the messages described to be used for the purpose of enabling a fair scheduling order are compatible with legacy stations. It will be clear to those skilled in the art how to make and use messages specifically for upgraded stations that can be made backwards compatible with legacy stations. [0052] A plurality of stations 301 - 1 through 301 -P are able to access communications medium 302 . Furthermore, the upgraded stations-depicted in the illustrative embodiment as station 301 - 1 , station 301 - 2 , station 301 - 3 , station 301 - 4 , station 301 - 5 , and 301 - 6 are able to communicate with each other while maintaining a fair scheduling order with respect to accessing shared-communications medium 302 . In any given time period, the upgraded stations can communicate up to N such coordinated flows to each other, where N is a positive integer. A flow is a stream of communication comprising frames between any two stations. A coordinated flow is a stream of communication comprising frames between two stations, in which the transmit times of the flows are scheduled fairly (e.g., in “round-robin” fashion, etc.). A flow between two stations can comprise data frames in one direction and acknowledgement frames in the other direction. [0053] In FIG. 3, coordinated flow 303 is being communicated by station 301 - 1 with station 301 - 5 . Coordinated flow 304 is being communicated by station 301 - 2 with station 301 - 4 . Coordinated flow 305 is being communicated by station 301 - 3 with station 301 - 6 . Other flows (coordinated or not) between alternative station pairs are possible. An admission control protocol enforces the maximum of N coordinated flows of fair scheduling order, that is, flows scheduled fairly with stations taking turns at using shared-communications medium 302 . Furthermore, the N coordinated flows are associated with a high, shared-communications medium access priority. Admission control and characteristics related to high priority are described later. [0054] It is also possible that two or more coordinated flows all originate within (i.e., are transmitted from) the same physical station or all terminate into (i.e., are received by) the same physical station. An example of this is two Internet browser sessions opened within the same station, each session contributing a different stream of data (e.g., video stream, audio stream, etc.). It will be clear to those skilled in the art how to handle more than one flow (coordinated or not) within the same physical station. [0055] In the examples that follow, station 301 - 2 serves in the examples as the hybrid coordinator and also as the access point of shared-communications medium 302 , unless otherwise specified. It will be clear to those skilled in the art how to make and use a hybrid coordinator and an access point. It will also be clear to those skilled in the art that separate stations can be used to support the hybrid coordinator and the access point functions. It will also be clear to those skilled in the art that the station serving as hybrid coordinator or access point or both can also be the station either transmitting or receiving coordinated flows on shared-communications medium 302 . [0056] [0056]FIG. 5 depicts a sequence of coordinated flows of the first embodiment of the present invention. Each coordinated flow is divided into portions, where each portion comprises frames (e.g., data frames, acknowledgement frames, etc.) that can be transmitted without interruption. Flow 303 comprises sequential portions 303 - 1 , 303 - 2 , and so on. Flow 304 comprises sequential portions 304 - 1 , 304 - 2 , and so on. Similarly, flow 305 comprises sequential portion 305 - 1 , and so on. [0057] In accordance with the illustrative embodiment, when station 301 - 1 finishes transmitting portion 303 - 1 , station 301 - 1 self-imposes a restriction as to when it can attempt to transmit the next portion (i.e., portion 303 - 2 ). Specifically, station 301 - 1 must wait a time interval that it calculates before attempting to transmit portion 303 - 2 . This restriction interval is greater than or equal to T*(N−1) milliseconds. N has already been defined. T is equal to the maximum length that a portion can be in milliseconds. Portions can be different sizes or of equal size across different flows. Portions can be different sizes or of equal size within a given flow. [0058] To ensure that flows are scheduled fairly (i.e., are coordinated), the self-imposed time restriction must end no earlier than during the flow that precedes the scheduled time for the station that imposes the restriction on itself. As depicted in FIG. 5, station 301 - 1 self-imposes interval 503 - 1 to ensure that station 301 - 1 does not attempt to transmit another portion until portion 305 - 1 is in the process of being transmitted. Furthermore, because portion 305 - 1 is being transmitted when station 301 -l's restriction interval ends, station 301 - 1 will then wait until it senses in well-known fashion that shared-communications medium 302 is idle (i.e., it uses physical carrier sensing). In addition, station 301 - 1 will have been tracking through its network allocation vector (NAV), in well-known fashion, interval 501 - 2 remaining in the transmission of portion 305 - 1 (i.e., it uses virtual carrier sensing). Once station 301 - 1 senses (physically, virtually, or both) that portion 305 - 1 is no longer being transmitted, station 301 - 1 can attempt to access shared-communications medium 302 to transmit portion 303 - 2 . The access sequence is described in detail later. [0059] Also depicted in FIG. 5, station 301 - 2 transmits portion 304 - 1 . Station 301 - 2 then self-imposes interval 502 - 1 to ensure that station 301 - 2 does not attempt to transmit another portion until portion 303 - 2 is in the process of being transmitted. Furthermore, because portion 303 - 2 is being transmitted, station 301 - 2 will wait until it senses in wellknown fashion that shared-communications medium 302 is idle (i.e., it uses physical carrier sensing). In addition, station 301 - 2 will have been tracking through its network allocation vector (NAV), in well-known fashion, interval 502 - 2 remaining in the transmission of portion 303 - 2 (i.e., it uses virtual carrier sensing). Once station 301 - 2 senses (physically, virtually, or both) that portion 303 - 2 is no longer being transmitted, station 301 - 2 can attempt to access shared-communications medium 302 to transmit portion 304 - 2 . [0060] Similarly, station 301 - 3 transmits portion 305 - 1 . Station 301 - 3 then self-imposes interval 503 - 1 to ensure that station 301 - 3 does not attempt to transmit another portion until portion 304 - 2 is in the process of being transmitted. Furthermore, because portion 304 - 2 is being transmitted, station 301 - 3 will wait until it senses in well-known fashion that shared-communications medium 302 is idle (i.e., it uses physical carrier sensing). In addition, station 301 - 3 will have been tracking through its network allocation vector (NAV), in well-known fashion, interval 503 - 2 remaining in the transmission of portion 304 - 2 (i.e., it uses virtual carrier sensing). Once station 301 - 3 senses (physically, virtually, or both) that portion 304 - 2 is no longer being transmitted, station 301 - 3 can attempt to access shared-communications medium 302 to transmit the next portion. [0061] It is possible for a station (either legacy or upgraded) to transmit frames not part of coordinated flows between transmissions of coordinated flow portions. Frame 505 is an example of such an incidental frame. A technique in accordance with the illustrative embodiment for transmitting incidental frames is described later. [0062] To allow for the contention period between flows, in some embodiments, each station waits at least (T+K)*(N−1) milliseconds before contending for access to shared-communications medium 302 . T and N are defined above. K is a padding factor in milliseconds to allow for gaps between successive portions being transmitted. K can be equal to the length in milliseconds of the arbitration interframe space governing the stations on shared-communications medium 302 . Alternatively, K can be greater than the length of the arbitration interframe space. [0063] In accordance with the illustrative embodiment of the present invention, a station can place itself in power save mode during the period in which it is waiting before it can transmit another portion of a coordinated flow. This is because the restriction interval is deterministic, allowing the sending station, the receiving station, or both to turn off their transmitters, receivers, or both for a known period. The transmitter and receiver at each station turn on again before the end of the restriction interval (before the station can contend again for access). It will be clear to those skilled in the art how to implement a power save mode at one or more stations. It will also be clear to those skilled in the art when during the restriction interval to turn off and turn back on components within a station as part of a power save mode. [0064] [0064]FIG. 6 depicts access sequence 601 - 1 comprising the events integral to accessing shared-communications medium 302 for the purpose of transmitting a coordinated flow. Stations that are capable of transmitting coordinated flows gain access to shared-communications medium 302 by following protocols that are in accordance with the illustrative embodiment of the present invention. [0065] Using the example provided earlier, station 301 - 1 has transmitted portion 303 - 1 at an earlier time and is already in the restriction time interval indicated by interval 501 - 1 . Meanwhile, portion 304 - 1 has also been transmitted. Portion 305 - 1 , of length T, is being transmitted when interval 501 - 1 ends (at time 604 ). Even though interval 501 - 1 ends, station 301 - 1 still carrier senses (physically, virtually, or both) in well-known fashion through interval 501 - 2 . Station 301 - 1 detects in well-known fashion at time 605 that shared-communications medium 302 is idle. In accordance with the illustrative embodiment, station 301 - 1 seeking access waits for backoff period 606 , equal to the length of the arbitration interframe space governing station 301 - 1 , starting from time 605 . At the end of backoff period 606 and if access is permitted, station 301 - 1 transmits portion 303 - 2 . (The techniques of acquiring access permission are described later.) Alternatively, prior to transmitting portion 303 - 2 , Station 301 - 1 can transmit a Request_to_Send (RTS) frame and then expect to receive a Clear_to_Send (CTS) frame, the significance of which is described later. [0066] Concurrent with the events described above, another station, legacy station 301 - 7 as an example, could also be attempting to access shared-communications medium 302 in well-known fashion, as depicted in access sequence 601 - 2 . Station 301 - 7 seeking access waits for interframe space 616 , equal to the length of the arbitration interframe space governing station 301 - 7 , starting from time 605 . Station 301 - 7 then waits the length of backoff period 618 , as calculated by station 301 - 7 . Station 301 - 7 calculates in well-known fashion the length of backoff period 618 by using the length of contention window 617 in a randomizing function and by using the length of timeslot 609 . If calculated in this way, backoff period 618 varies in length by multiples of timeslot 609 from one access attempt to another, as represented by the multiple appearances of timeslot 609 in FIG. 6. [0067] The interval that is the length of backoff period 606 is shorter than the interval that is the sum of the lengths of interframe space 616 and backoff period 618 in most practical cases. Therefore, station 301 - 1 beats station 301 - 7 in gaining access to shared-communications medium 302 . If station 301 - 7 has to transmit one or more frames, it has to wait until conditions favor it. Examples of such conditions include a coordinated flow scenario with a particular transmitted portion that is of length significantly shorter than T, in which case, stations still in self-imposed waiting will not be ready to contend with station 301 - 7 for access, and station 301 - 7 wins access. In another example, station 301 - 7 can be polled, as described later. [0068] Access to shared-communications medium 302 for the purpose of transmitting a coordinated flow is governed by admission control, which enforces the characteristic of no more than N coordinated flows being present during a given time period. Admission control can also be used to indicate to a particular station if that station is permitted to transmit a portion of a coordinated flow. Permission can be granted or denied based on the station requesting access, on the status of flows already being transmitted, or on a combination of factors. For instance, the transmission of coordinated flows might be pre-empted by another service or function using shared-communications medium 302 . In other words, admission control is used to determine and indicate if shared-communications medium 302 is accessible to a particular station or stations at a particular moment in time for the purpose of transmitting a coordinated flow portion. It will be clear to those skilled in the art how to determine criteria that define accessibility. [0069] There are three admission control techniques disclosed in accordance with the illustrative embodiment of the present invention. FIG. 7 depicts a message flow diagram of the first of three variations of admission control, in accordance with the illustrative embodiment of the present invention. Signal stream 701 - 1 represents the sequence of messages transmitted on shared-communications medium 302 by station 301 - 1 seeking access for the purpose of transmitting a coordinated flow to station 301 - 6 . Signal stream 701 - 2 represents the sequence of messages transmitted by station 301 - 2 , the access point, on shared-communications medium 302 . Signal stream 701 - 3 represents the sequence of messages transmitted by station 301 - 6 on shared-communications medium 302 . [0070] In the first variation, station 301 - 1 seeking access sends query message 702 (i.e., “Q” for “query”) to station 301 - 2 . Query message 702 serves to determine whether or not additional flows can be coordinated. Station 301 - 2 responds to query message 702 with status message 703 (i.e., “S” for “status”). The purpose of status message 703 is to indicate whether or not station 301 - 1 is allowed to transmit a coordinated flow. In the example, station 301 - 2 informs station 301 - 1 that station 301 - 1 is allowed to transmit. [0071] After admission control, station 301 - 1 executes an RTS frame 704 / CTS frame 705 exchange with station 301 - 2 , in accordance with the illustrative embodiment of the present invention. The RTS/CTS exchange is described in detail later. Station 301 - 1 then communicates a portion of a coordinated flow to station 301 - 6 , comprising data frames 706 and 708 (of possibly many frames) and corresponding acknowledgement frames (“ACK” frame) 707 and 709 . [0072] [0072]FIG. 8 depicts a message flow diagram of the second variation of admission control, in accordance with the illustrative embodiment of the present invention. Signal stream 801 - 1 represents the sequence of status messages transmitted by station 301 - 2 , the access point, on shared-communications medium 302 . In the example, the status messages are represented by periodically-transmitted beacon frames. Signal streams 801 - 2 , 801 - 3 , 801 - 4 , 801 - 5 , and 801 - 6 respectively represent the sequence of messages transmitted on shared-communications medium 302 by stations 301 - 1 , 301 - 3 , 301 - 4 , 301 - 5 , and 301 - 6 seeking access on shared-communications medium 302 for the purpose of transmitting coordinated flows. In the example, a maximum of three coordinated flows are allowed concurrently. Each coordinated flow comprises one or more portions of data frames. [0073] Stations 301 - 1 , 301 - 3 , and 301 - 4 are initially in the process of transmitting flows 803 , 804 , and 805 respectively. Station 301 - 2 , the access point, reflects this by indicating in beacon frames 802 - 1 and 802 - 2 that there are zero (0) opportunities available for another station to transmit a coordinated flow. [0074] Station 301 - 1 then stops transmitting flow 803 , while stations 301 - 3 and 301 - 4 continue to transmit. This is reflected in beacon frame 802 - 3 , which indicates that there is one (1) opportunity available for another station to transmit a coordinated flow. [0075] Station 301 - 5 , in seeking to transmit a coordinated flow, first reads the information from beacon frame 802 - 3 and determines that it is permitted to contend for access to transmit. Station 301 - 5 starts transmitting flow 806 . Shortly thereafter, station 301 - 4 stops transmitting flow 805 . The next beacon frame 802 - 4 continues to show that there is one (1) opportunity available for another station to transmit a coordinated flow, even though a different mix of stations are transmitting flows at the end of the pertinent beacon interval compared with the mix of stations that were transmitting flows at the beginning of the beacon interval. [0076] Station 301 - 6 , in seeking to transmit a coordinated flow, first reads the information from beacon frame 802 - 4 and determines that it is permitted to contend for access to transmit. Station 301 - 6 starts transmitting flow 807 . Stations 301 - 3 and 301 - 5 continue to transmit flows. Consequently, beacon frame 802 - 5 reflects this by indicating that there are zero (0) opportunities available for another station to transmit a coordinated flow. [0077] It will be clear to those skilled in the art how to periodically distribute system status information, either by using beacon frames or other messages, to indicate whether or not additional coordinated flows can be transmitted. It will also be clear to those skilled in the art how to represent the status information (e.g., number of additional coordinated flows permitted, number of coordinated flows already present, etc.). [0078] Station 301 - 2 can also distribute other parameters related to coordinated flows. For instance, the access point can transmit beacon frames that comprise information related to parameters T, N, and K. This allows the access point to tune how much bandwidth is allocated to coordinated flow traffic on shared-communications medium 302 . It will be clear to those skilled in the art how to distribute parameters related to coordinated flows via the access point to other stations. [0079] [0079]FIG. 9 depicts a message flow diagram of the third variation of admission control, in accordance with the illustrative embodiment of the present invention. Signal stream 901 - 1 represents the sequence of messages transmitted on shared-communications medium 302 by station 301 - 1 seeking access on shared-communications medium 302 for the purpose of transmitting a coordinated flow to station 301 - 3 . Signal stream 901 - 2 represents the sequence of messages transmitted by station 301 - 2 , the access point, on shared-communications medium 302 . Signal stream 901 - 3 represents the sequence of messages transmitted by station 301 - 3 on shared-communications medium 302 . Signal stream 901 - 4 represents the sequence of messages transmitted by station 301 - 4 on shared-communications medium 302 . Signal stream 901 - 5 represents the sequence of messages transmitted by station 301 - 5 on shared-communications medium 302 . In addition, three other station pairs (not shown) are already exchanging coordinated flows. In the example, N is equal to four. [0080] In the third variation, station 301 - 1 seeking access monitors transmissions on shared-communications medium 302 during the interval in which stations 301 - 4 and 301 - 5 are exchanging a coordinated flow, as well as the three other station pairs not shown. Each transmitting station (e.g., stations 301 - 4 and 301 - 5 , etc.) tags each data frame transmitted as part of a coordinated flow, depicted by frames 904 and 906 (i.e., “CF” for “coordinated flow”). The tag is a unique label distinguishable from other information fields in the frame. It will be clear to those skilled in the art how to tag a message to reflect a specific condition. Transmitted control frames that are associated with coordinated flows (e.g., RTS frame 902 , CTS frame 903 , ACK frames 905 and 907 , etc.) can also be tagged. Tagging of control frames increases the spatial coverage of the presence of traffic because control frames are transmitted from different spatial locations than that of the station transmitting the data frames and possibly at a lower physical layer rate. [0081] Since station 301 - 1 sees frames tagged with indications corresponding to at least four coordinated flows during the search interval and since four is the maximum allowed in the example (i.e., N=4), station 301 - 1 does not attempt to transmit a coordinated flow. It will be clear to those skilled in the art how to determine a suitable search interval in which to detect the presence or absence of certain types of messages, such as tagged frames, etc. [0082] Station 301 - 4 eventually finishes its sequence that is used in communicating with station 301 - 5 . Subsequently, station 301 - 1 sees that a transmission opportunity is available by detecting less than N coordinated flows present during another search interval. After admission control, station 301 - 1 exchanges an RTS frame 908 /CTS frame 909 sequence with station 301 - 2 , in accordance with the illustrative embodiment of the present invention. This is described in detail later. Station 301 - 1 then communicates a portion of a coordinated flow with station 301 - 3 , comprising data frame 910 (of possibly many frames) with corresponding ACK frame 911 . Note that frames 908 , 909 , 910 , and 911 are tagged (i.e., “CF”), indicating the traffic that is part of a coordinated flow. [0083] [0083]FIG. 10 depicts a message flow diagram, in accordance with the second illustrative embodiment of the present invention. Specifically, FIG. 10 depicts an example of a sequence to be transmitted comprising a coordinated flow portion, in accordance with the illustrative embodiment of the present invention. Signal stream 1001 - 1 represents the sequence of messages transmitted on shared-communications medium 302 by station 301 - 1 for the purpose of communicating with station 301 - 3 . Signal stream 1001 - 2 represents the sequence of messages transmitted by station 301 - 2 , the access point, on shared-communications medium 302 . Signal stream 1001 - 3 represents the sequence of messages transmitted by station 301 - 3 . NAV timeline 1002 tracks the status of the network allocation vector for stations within receiving range of station 301 - 2 . The network allocation vector supports the virtual carrier sensing function of those stations. The network allocation vector is set by the duration field in CTS frame 1004 and can also be set by other frames. It will be clear to those skilled in the art how to use the network allocation vector, virtual carrier sensing function, and duration field. [0084] The sequence to be exchanged comprises Request_to_Send (RTS) frame 1003 ; Clear_to_Send (CTS) frame 1004 ; data frames 1007 , 1011 , and 1013 ; and acknowledgement (ACK) frames 1008 , 1012 , and 1014 . Station 301 - 1 starts off by transmitting RTS frame 1003 to station 301 - 2 in well-known fashion. Station 301 - 1 sets the duration field in RTS frame 1003 to the calculated transmission time remaining in the sequence (i.e., through the end of the portion to be transmitted), in accordance with the illustrative embodiment of the present invention. This has the effect of providing stations within receiving range of station 301 - 1 with virtual carrier sensing information. RTS frame 1003 is transmitted to station 301 - 2 whether the subsequent coordinated flow portion (i.e., comprising data frames and ACK frames depicted) is also communicated with station 301 - 2 or to another station (e.g., station 301 - 3 ). It will be clear to those skilled in the art how to convey duration field information by using a frame (i.e., RTS, CTS, or other frame type). [0085] Upon receiving RTS frame 1003 , station 301 - 2 responds by transmitting CTS frame 1004 to station 301 - 1 in well-known fashion. Station 301 - 2 sets the duration field in CTS frame 1004 based on what was received in RTS frame 1003 . This has the effect of quieting all stations (via virtual carrier sensing) within receiving range of station 301 - 2 during the remaining part of the sequence, as depicted in FIG. 11. Station 301 - 1 has a range represented by coverage ring 1101 - 1 , which is not sufficient to reach station 301 - 4 (i.e., stations 301 - 1 and 301 - 4 are “hidden” from each other). In contrast, station 301 - 2 has a range represented by coverage ring 1101 - 2 , which is sufficient to reach all stations in the area. Consistent with performing its hybrid coordinator or access point function within telecommunications system 300 , station 301 - 2 is located within the BSS area where all stations can hear station 301 - 2 . [0086] The duration field value representing time interval 1005 is derived in well-known fashion from the duration field value provided by RTS frame 1003 , accounting for the short interframe space between RTS frame 1003 and CTS frame 1004 , as well as the duration of CTS frame 1004 itself. The duration field used in RTS frame 1003 can be calculated, for example, at station 301 - 1 by adding up the anticipated transmission times of the relevant signals to be subsequently transmitted (e.g., CTS frame, data frames, ACK frames, etc.) and the lengths of the associated interframe spaces between frames. The value can be determined empirically, it can be estimated, or it can be determined in another way. It can comprise a margin of variation in transmission, or it can comprise no extra margin. It can be adjusted to ensure that quieted stations will not remain silent past the very end of the coordinated flow portion. It will be clear to those skilled in the art how to calculate and set the value of the duration field in RTS frame 1003 . [0087] Upon receiving CTS frame 1004 , station 301 - 1 initiates the coordinated flow portion by transmitting data frame 1007 in well-known fashion. Data frame 1007 is the first of possibly many data frames constituting the current portion being communicated. Alternatively, data frame 1007 or individual data frames that follow can comprise multiple frames that have been concatenated into a single frame. Concatenation increases the efficiency of shared-communications medium 302 because it reduces the medium access control and physical layer header overhead. Concatenation can occur during the restriction interval immediately preceding the transmission of the current portion. It will be clear to those skilled in the art how to save up frames for transmission and to concatenate two or more saved frames together into a single frame. [0088] Station 301 - 3 , upon receiving data frame 1007 , responds by transmitting ACK frame 1008 in well-known fashion. Station 301 - 1 then follows up by transmitting data frame 1011 , and so on. The coordinated flow portion ends when the final ACK frame in the portion (i.e., ACK frame 1014 ) is received by station 301 - 1 . The interval between each data frame and the corresponding ACK frame, interval 1009 , is the length of short interframe space, as is known in the art. The interval between each ACK frame and the next data frame, interval 1010 , is also the length of short interframe space, as is known in the art. [0089] It will be clear to those skilled in the art how to format, encode, transmit, receive, and decode RTS frame 1003 ; CTS frame 1004 ; data frames 1007 , 1011 , and 1013 ; and ACK frames 1008 , 1012 , and 1014 . [0090] [0090]FIG. 12 depicts a message flow diagram, in accordance with the third illustrative embodiment of the present invention. Signal stream 1201 - 1 represents the sequence of messages transmitted on shared-communications medium 302 by station 301 - 1 for the purpose of communicating with station 301 - 3 . Signal stream 1201 - 2 represents the sequence of messages transmitted by station 301 - 2 , the access point, on shared-communications medium 302 . Signal stream 1201 - 3 represents the sequence of messages transmitted by station 301 - 3 . [0091] Station 301 - 1 starts off by transmitting RTS frame 1202 to station 301 - 2 in well-known fashion. Station 301 - 1 can set the duration field in RTS frame 1202 to provide stations within receiving range of station 301 - 1 with virtual carrier sensing information. [0092] In this example, station 301 - 1 never receives a CTS frame that corresponds to RTS frame 1202 . In accordance with the illustrative embodiment of the present invention, station 301 - 1 assumes that a “short” collision has occurred. A short collision can indicate a collision with another RTS frame sent by another station also seeking to transmit a coordinated flow portion, so a random backoff is required to separate the coordinated flow portions across the two stations. Consequently, station 301 - 1 retransmits an RTS frame, RTS frame 1203 , but only after waiting for a backoff interval equal to the arbitration interframe space governing station 301 - 1 plus a random number of slots, in accordance with the illustrative embodiment of the present invention. [0093] Upon receiving RTS frame 1203 , station 301 - 2 responds by transmitting CTS frame 1204 to station 301 - 1 in well-known fashion. Station 301 - 2 sets the duration field in CTS frame 1204 to quiet other stations, as already described. [0094] Upon receiving CTS frame 1204 , station 301 - 1 transmits data frame 1205 in well-known fashion. Station 301 - 3 , upon receiving data frame 1205 , responds by transmitting ACK frame 1206 in well-known fashion. Stations 301 - 1 and 301 - 3 then follow up by exchanging the remaining frames in the coordinated flow portion. [0095] It will be clear to those skilled in the art how to format, encode, transmit, receive, and decode RTS frame 1202 and 1203 , CTS frame 1204 , data frame 1205 , and ACK frame 1206 . [0096] [0096]FIG. 13 depicts a message flow diagram in accordance with the fourth illustrative embodiment of the present invention. Signal stream 1301 - 1 represents the sequence of messages transmitted on shared-communications medium 302 by station 301 - 1 for the purpose of communicating with station 301 - 3 . Signal stream 1301 - 2 represents the timeline of station 301 - 2 , the access point/hybrid coordinator, on shared-communications medium 302 . Signal stream 1301 - 3 represents the sequence of messages transmitted by station 301 - 3 . In this example, station 301 - 1 is in the middle of a coordinated flow portion already in progress, exchanging frames with station 301 - 3 . [0097] Station 301 - 1 transmits data frame 1302 in well-known fashion. Station 301 - 3 , upon receiving data frame 1302 , responds by transmitting ACK frame 1303 in well-known fashion. Station 301 - 1 then follows up by transmitting data frame 1304 . Station 301 - 1 then expects to receive corresponding ACK frame, but does not. [0098] It is important that the coordinated flow transmissions get restarted as quickly as possible to prevent station 301 - 2 (or other stations) from attempting to transmit on shared-communications medium 302 . The restart interval has to be relatively short, since a hybrid coordinator uses point interframe space (PIFS) to determine when it attempts to transmit, as is known in the art. Therefore, in accordance with the illustrative embodiment of the present invention, station 301 - 1 waits the length of PIFS, corresponding to interval 1305 , after having transmitted data frame 1304 and then retransmits the data frame, represented by data frame 1306 . Station 301 - 1 concludes within interval 1305 that the ACK frame is missing and that it must retransmit the data frame. Station 301 - 3 acknowledges receipt of data frame 1306 by transmitting back ACK frame 1307 . Stations 301 - 1 and 301 - 3 continue exchanging frames until finished, without interruption from station 301 - 2 . [0099] It will be clear to those skilled in the art how to format, encode, transmit, receive, and decode data frames 1302 , 1304 , and 1306 , and ACK frames 1303 and 1307 . [0100] Traffic with a low latency tolerance but not necessarily requiring a high data rate (e.g., voice traffic, etc.) will have to contend with coordinated flow traffic for overall access to shared-communications medium 302 . In this case, the priority traffic not part of a coordinated flow that needs to be mixed with coordinated flow traffic is polled from a central location, in accordance with the illustrative embodiment of the present invention. FIG. 14 depicts access sequences in accordance with the fifth illustrative embodiment of the present invention. Access timing sequence 1401 - 1 represents the procedure of station 301 - 1 on shared-communications medium 302 . Access timing sequence 1401 - 2 represents the procedure of station 301 - 2 , as hybrid coordinator (i.e., the central location used for polling), accessing shared-communications medium 302 in a timely manner. In short, stations 301 - 1 and 301 - 2 are vying for contention of some of the same shared resources at the same time. Both sequences start at the time point in time, at which busy medium 1401 becomes idle. In well-known fashion, both stations 301 - 1 and 301 - 2 carrier-sense at time 1402 that shared-communications medium 302 has become idle and start timing the interframe space. Station 301 - 1 seeking access to transmit a coordinated flow waits for backoff interval 1403 equal to the length of the arbitration interframe space (AIFS). In contrast, station 301 - 2 waits for interframe space 1403 , equal to the length of the point interframe space (PIFS), which is shorter than the length of the AIFS used by station 301 - 1 . Consequently, station 301 - 2 gets an advantage over station 301 - 1 in accessing shared-communications medium 302 . [0101] Subsequent to waiting backoff interval 1403 , station 301 - 1 can then transmit. Meanwhile, on its own timeline and after waiting interframe space 1404 , station 301 - 2 calculates and then waits the length of its backoff period 1406 , as calculated by station 301 - 2 . Station 301 - 2 calculates in well-known fashion the length of backoff period 1406 using the length of contention window 1405 in a randomizing function and the length of timeslot 1407 . Backoff period 1406 can vary in length from one access attempt to another, as represented by the multiple appearances of timeslot 1407 . At the end of backoff period 1406 , station 301 - 2 can initiate a polled traffic sequence with one or more other stations for the purposes of exchanging the polled (e.g., voice, etc.) traffic. The polled traffic sequence comprises one or more data frames and corresponding ACK frames. Station 301 - 2 can be part of the actual data frame exchange, or the data frame exchange can involve stations other than station 301 - 2 . It will be clear to those skilled in the art how a hybrid coordinator and associated stations use polling to exchange information. [0102] As depicted in FIG. 14, the polled traffic is able to compete for access to shared-communications medium 302 , since the combined intervals 1404 and 1405 can be adjusted to be shorter than backoff interval 1403 , at least statistically over many access sequences, in accordance with the illustrative embodiment of the present invention. [0103] [0103]FIG. 15 depicts a flowchart of the tasks performed by station 301 - 1 in accessing shared-communications medium 302 for the purpose of exchanging a coordinated flow, in accordance with the illustrative embodiment of the present invention. It will be clear to those skilled in the art which of the tasks depicted in FIG. 15 can be performed simultaneously or in a different order than that depicted. [0104] At task 1501 , station 301 - 1 contends for access to shared-communications medium 302 . It will be clear to those skilled in the art how to contend for shared-communications medium 302 . [0105] At task 1502 , station 301 - 1 transmits a first portion of a flow into shared-communications medium 302 , wherein the first portion has a maximum length of T milliseconds. It will be clear to those skilled in the art how to transmit into shared-communications medium 302 . [0106] At task 1503 , station 301 - 1 waits at least T*(N−1) milliseconds before again contending for access to shared-communications medium 302 to transmit a second portion of the flow. It will be clear to those skilled in the art how to wait before again contending for shared-communications medium 302 . [0107] It is to be understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents.

A technique is disclosed for maintaining fairness in scheduling order while communicating multiple streams on a shared-communications medium. Simulations have shown that the scheduling order of when stations transmit is of great importance. Typically, the scheduling order of multiple streams of message traffic on a shared-communications medium is unfair, at least in the short term. Streaming applications, however, demand fairness in short term scheduling. Otherwise, the intermediate delays would be unacceptably uneven. To address the delay problems associated with multiple streams on a shared-communications medium, each station transmits a portion of a coordinated flow. After transmitting the portion, the station self-imposes a restriction interval, during which time, the station cannot contend again for the purpose of transmitting the next portion of the coordinated flow.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo receiver and a photo receiving method, and more particularly, to a signal cutoff detector and a signal cutoff detecting method. 2. Description of the Related Art For enhancing reliability of an optical communication system to quickly take countermeasure in case a failure occurs, demanded is improving a failure detection function of each part of the system. For such a purpose, a photo receiver is conventionally provided with a function of detecting a signal being cut off. Structure of a conventional signal cutoff detection circuit is shown in FIG. 12 . The signal cutoff detection circuit of FIG. 12 includes a photo detector 10 , a preamplifier 11 , an amplifier or limiter amplifier 12 with an automatic gain control (AGC) function, a band-pass filter 13 , an amplifier 14 , a limiter amplifier 15 , a peak value detection circuit 16 , a delay element 17 , a discrimination circuit 18 and a comparator 19 . A light signal applied to the photo receiver is converted into an electric signal by the photo detector 10 and then amplified into a signal of a predetermined level by the preamplifier 11 and the AGC amplifier or limiter amplifier 12 . An output of the AGC amplifier or limiter amplifier 12 is branched into two, one of which is applied to a data input terminal of the discrimination circuit 18 . The other signal is input to the band-pass filter 13 , in which a clock component contained in the data signal is extracted. After being amplified to a signal of a predetermined level by the amplifier 14 and the limiter amplifier 15 , the extracted clock signal is input to the discrimination circuit 18 , in which it is used as an identification clock of a data signal. A delay difference between a clock signal and a data signal is compensated for by the delay element 17 . Here, a part of the output of the amplifier 14 is input to the peak value detection circuit 16 . At the peak value detection circuit 16 , a peak level of the input clock signal is detected and the comparator 19 determines whether a clock signal exists or not based on whether the detected level reaches a predetermined level. When the determination is made that no clock signal exists, it can be known that no appropriate light signal is input to the photo receiver or that some abnormality occurs in the photo receiver. In the field of optical communication today, there are many cases where an optical relay amplifier is used as a relay and where wave-length division multiplexing (WDM) transmission is conducted for increasing a transmission capacity per optical fiber. In such a transmission system, in a case where a failure on a transmission path, a photo transmitter and receiver or a relay eliminates a light data signal, an amplified spontaneous emission (ASE) generated at each optical relay amplifier is accumulated to reach a photo receiver. On the other hand, in wave-length division multiplexing (WDM) transmission, when a light data signal of a part of wave-length channels is lost due to some failure or other, processing of superposing a dummy signal (continuous wave (CW) light) on a wave-length whose signal is lost called “keep alive” is conducted in some cases in order to balance power between the respective wave-length channels. In such cases, while wave-length light itself exists, no signal exists, so that such cases should be detected being abnormal. At the time of a noise caused by ASE or the time of keep alive, a photo receiver might be subjected to a high-level noise, which makes it difficult for conventional methods to detect signal cutoff. SUMMARY OF THE INVENTION An object of the present invention is to provide a signal input cutoff detector having a function of reliably detecting signal cutoff in a wave-length division multiplexing (WDM) transmission system and a transmission system including an optical relay amplifier. According to the first aspect of the invention, a signal input cutoff detector comprises a signal cutoff detector which detects a level of a data signal converted from a light input signal into an electric signal and when the level is below a predetermined value, generates a first alarm signal; and an out-of-synchronization detector which monitors a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and when a level of the control signal exceeds a predetermined value, generates a second alarm signal. In the preferred construction, the signal input cutoff detector further comprises an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal. In another preferred construction, the signal cutoff detector includes an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal. In another preferred construction, the signal input cutoff detector further comprises an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal. In another preferred construction, the signal input cutoff detector further comprises an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the delay time being half a time length of one bit of the data signal. In another preferred construction, the signal input cutoff detector further comprises an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the delay time being half a time length of one bit of the data signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal input cutoff detector further comprises an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the delay time being half a time length of one bit of the data signal, and the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal cutoff detector further including a hysteresis amplifier provided at an input part of the signal cutoff detector. In another preferred construction, the signal input cutoff detector further comprising an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal cutoff detector further including a hysteresis amplifier provided at an input part of the signal cutoff detector. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and which further comprises a hysteresis amplifier provided at an input part of the signal cutoff detector. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and a hysteresis amplifier provided at an input part of the signal cutoff detector, the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and a hysteresis amplifier provided at an input part of the signal cutoff detector, the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the delay time being half a time length of one bit of the data signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and a hysteresis amplifier provided at an input part of the signal cutoff detector, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal. In another preferred construction, the signal input cutoff detector further comprising an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, and the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal, the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal, the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, and the delay time being half a time length of one bit of the data signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculats an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal cutoff detector further including a hysteresis amplifier provided at an input part of the signal cutoff detector, and the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal. According to the second aspect of the invention, a photo receiver comprises a photo detector which converts a light input signal into an electric signal, an amplifier which amplifies the electric signal to have a predetermined amplitude, a frequency phase-locked loop which contains a VCO and generates a clock synchronized with an output of the amplifier and a discrimination circuit for discriminating an output of the amplifier by the clock, and a signal input cutoff detector, wherein the signal input cutoff detector including a signal cutoff detector which detects a level of a data signal converted from a light input signal into an electric signal and when the level is below a predetermined value, generates a first alarm signal, and an out-of-synchronization detector which monitors a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and when a level of the control signal exceeds a predetermined value, generates a second alarm signal. In the preferred construction, the signal input cutoff detector further including an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal. In another preferred construction, the signal input cutoff detector further including an alarm processor which generates a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, and the autocorrelation detector including a delay element which delays the data signal by a predetermined delay time to output a delayed data signal, an exclusive OR circuit which calculates an exclusive OR of the data signal and the delayed data signal to output an exclusive OR signal, and a first integrator which calculates a mean value of the exclusive OR signal, the delay time being half a time length of one bit of the data signal. In another preferred construction, the signal cutoff detector including an autocorrelation detector which calculates an autocorrelation of the data signal to output an autocorrelation signal, and a first comparator which compares the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputs the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal cutoff detector further including a hysteresis amplifier provided at an input part of the signal cutoff detector. In another preferred construction, the out-of-synchronization detector including a second comparator which compares a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputs the second alarm signal. According to the third aspect of the invention, a signal input cutoff detecting method comprising the steps of: detecting a level of a data signal converted from a light input signal into an electric signal and when the level is below a predetermined value, generating a first alarm signal, and monitoring a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and when a level of the control signal exceeds a predetermined value, generating a second alarm signal. In the preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal. In another preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. In another preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, and the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. In another preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, and the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough, and the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. In another preferred construction, the signal input cutoff detecting method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal, wherein the signal input cutoff detection step includes: autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough, and the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. According to another aspect of the invention, a photo receiving method comprising step of converting a light input signal into an electric signal and amplifying the converted signal to have a predetermined amplitude, step of, with a VCO contained, generating a clock synchronized with a data signal amplified to the predetermined amplitude, step of discriminating a data signal amplified to the predetermined amplitude by the clock, signal input cutoff detection step of detecting a level of a data signal converted from a light input signal into an electric signal and when the level is below a predetermined value, generating a first alarm signal, and out-of-synchronization detection step of monitoring a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and when a level of the control signal exceeds a predetermined value, generating a second alarm signal. In the preferred construction, the photo receiving method further comprising alarm processing step of generating a third alarm signal according to generation conditions of the first alarm signal and second alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal. In another preferred construction, the signal input cutoff detection step includes autocorrelation detection step of calculating an autocorrelation of the data signal to output an autocorrelation signal, and first comparison step of comparing the autocorrelation signal with at least one predetermined reference voltage and when the autocorrelation signal is larger, outputting the first alarm signal, the at least one predetermined reference voltage including a first reference voltage having a value between the mean value obtained when the data signal is large enough and zero, and a second reference voltage higher than the mean value obtained when the data signal is large enough. In another preferred construction, the out-of-synchronization detection step includes second comparison step of comparing a VCO control signal which controls a voltage controlled oscillator (VCO) to have a frequency and a phase synchronized with the data signal and a predetermined reference voltage and when the VCO control signal is larger, outputting the second alarm signal. As described in the foregoing, the present invention is provided with a signal cutoff detector for detecting a level of an input data signal and when the level is lower than a predetermined value, generating a first alarm signal and an out-of-synchronization detector for generating a second alarm signal when a VCO control signal from a frequency phase-locked loop exceeds a predetermined value, that is, when the signal is out of synchronization. Using these two detectors to take detection results of each detector into consideration enables reliable generation of an alarm against a failure, as well as enabling a failing part to be cut out. Other objects, features and advantages of the present invention will become clear from the detailed description given herebelow. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only. In the drawings: FIG. 1 is a diagram showing a basic structure of a signal input cutoff detector according to the present invention; FIG. 2 is a diagram showing a structure of a signal input cutoff detector according to a first embodiment of the present invention; FIG. 3 is a diagram showing a structure of an autocorrelation detector for use in a signal input cutoff detector of the present invention; FIG. 4 is a diagram showing a relation between a light input level and an output of the autocorrelation detector; FIG. 5 is a diagram showing a relation between a light input level and an output of the autocorrelation detector (at the time of noise derived from ASE when a light data signal is cut off or at the time of keep alive); FIG. 6 is a diagram showing a structure of a signal input cutoff detector according to a second embodiment of the present invention; FIG. 7 is a diagram showing a relation between a light input level and an output of an autocorrelation detector in a case where a gain of an AGC amplifier or a limiter amplifier gives preference to stability; FIG. 8 is a diagram showing a relation between a light input level and an output of the autocorrelation detector (at the time of noise derived from ASE when a light data signal is cut off or at the time of keep alive) in a case where a gain of the AGC amplifier or the limiter amplifier gives preference to stability; FIG. 9 is a diagram showing a relation between a light input level and an output of the autocorrelation detector according to the second embodiment; FIG. 10 is a diagram showing a relation between a light input level and an output of the autocorrelation detector (at the time of noise derived from ASE when a light data signal is cut off or at the time of keep alive) according to the second embodiment; FIG. 11 is a table showing an alarm generation condition at each failure; FIG. 12 is a diagram showing a structure of a photo receiver according a conventional technique; FIG. 13 is a diagram showing a photo receiver using the signal input cutoff detector of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiment of the present invention will be discussed hereinafter in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structures are not shown in detail in order to unnecessary obscure the present invention. Structure and operation of a signal input cutoff detector according to the present invention will be described with reference to the drawings. (First Embodiment) Structure of a signal input cutoff detector according to a first embodiment of the present invention is shown in FIG. 1 . The signal input cutoff detector of the present embodiment includes a signal cutoff detector 101 , an out-of-synchronization detector 102 and an alarm processor 103 . The signal cutoff detector 101 determines whether an applied signal has a predetermined autocorrelation or not and when it fails to have the predetermined autocorrelation, outputs a signal indicating that an abnormality occurs. When a level of a VCO control signal from a frequency phase-locked loop for synchronizing frequencies and phases of an input signal and a VCO with each other becomes higher than a predetermined level, the out-of-synchronization detector 102 determines that out-of-synchronization occurs to output a signal indicating that an abnormality occurs. The alarm processor 103 receives output signals of the signal cutoff detector 101 and the out-of-synchronization detector 102 to output a signal indicating that an abnormality occurs taking the output signals of the signal cutoff detector 101 and the out-of-synchronization detector 102 into consideration. In the present embodiment, when at least one of the above-described circuits outputs a signal indicating that an abnormality occurs, the alarm processor determines that an abnormality occurs at the present photo receiver to output a signal indicative of occurrence of an abnormality. Structure of the signal input cutoff detector is shown in FIG. 2 including the internal structures of the above-described signal cutoff detector 101 and out-of-synchronization detector 102 . In FIG. 2, the signal cutoff detector 101 is structured to include an autocorrelation detector 201 and a comparator 202 . The out-of-synchronization detector 102 is structured to include a comparator 203 . One example of the structure of the autocorrelation detector 201 is shown in FIG. 3 . The autocorrelation detector 201 of FIG. 3 is structured to include a delay element 301 , an exclusive-OR circuit 302 and an integrator 303 . A delay time by the delay element 301 is set to be half the length of one bit of a data signal in the present embodiment. In order to calculate an autocorrelation of an applied data signal, the autocorrelation detector 201 branches the data signal into two and delays one of them by a predetermined time by the delay element 301 to obtain an exclusive OR with the other, which exclusive OR is integrated for a predetermined time at the integrator 302 at the subsequent stage and a mean value of the integration is output. The output of the autocorrelation detector 201 is compared with a predetermined reference voltage at the comparator 202 to make a determination of normality/abnormality. At this time, two reference voltages (hereinafter referred to as Vref1 and Vref2) for detecting both abnormalities in a case where the output of the autocorrelation detector 201 is larger than that a normal voltage (VS) and in a case where the same is smaller than the normal voltage (VS). Under the conditions, when the output of the autocorrelation detector 201 falls between Vref1 and Vref2, it is determined that the output is normal and otherwise, it is determined that the same is abnormal. Next, the out-of-synchronization detector will be described. The out-of-synchronization detector compares, at the comparator 203 , a VCO control signal from a frequency phase-locked loop for synchronizing frequencies and phases of a data signal and a VCO with a predetermined reference voltage and when the signal is larger than the reference voltage, determines that out-of-synchronization, that is, an abnormality occurs, to output a signal to that effect (a logical signal which attains a logical high level in a case of abnormality). Although the VCO control signal is a control signal for synchronizing a frequency and a phase of a VCO with those of a data signal, it corresponds to a phase error or a frequency error between the VCO and the data. Monitoring the signal therefore enables a degree of a phase error or a frequency error to be found. Operation of the signal input cutoff detector of the present embodiment will be described with reference to FIGS. 4 and 5. Relation between power of an input light signal and an output of the autocorrelation detector 201 is shown in FIG. 4 . When a light input level is high, if a data signal is an NRZ code having a mark rate of ½, the output will be approximately one-fourth (VS) a peak value of the data signal. However, when the light input level is lowered to make noise power relatively large, autocorrelation starts failing to approximate to a random noise, whereby the output increases from one-fourth the peak value of the data signal and exceeds the alarm threshold value Vref2 to approximate to half (VN) the peak value of the data signal. Accordingly, the signal cutoff detector 101 is allowed to generate an alarm at the light input levels P0 (light input is cut off) to P4 (alarm threshold value Vref2). Also when the signal itself fails to exist due to a failure of an electric circuit, the detector is naturally allowed to generate an alarm. However, since the detector will not generate an alarm unless the light input level goes below P4 (alarm threshold value Vref2), it is not allowed to generate an alarm over all the regions P0 to P6 in which a predetermined transmission path quality can not be ensured because of deterioration of an S/N of the data signal. On the other hand, while the out-of-synchronization detector 102 is allowed to generate an alarm over the light input levels P0 to P6 in which a predetermined transmission quality can not be ensured because of deterioration of an S/N of the data signal, when the signal itself fails to exist due to a failure of an electric circuit, the VCO control signal can not be detected, disabling generation of an alarm. In other words, use both of the signal cutoff detector 101 and the out-of-synchronization detector 102 enables reliable generation of an alarm over all the regions of the light levels P0 to P6 in which a predetermined transmission quality can not be ensured due to deterioration of an S/N of the data signal and also at the time of a failure of an electric circuit. FIG. 5 shows a light input level and an output of the autocorrelation detector 201 at the time only of a noise derived from ASE when a light data signal is cut off or at the time of CW reception in keep alive. When a modulation signal to be superposed on a light signal is cut off, a random noise is generated, so that a level half (VN) the peak value of the data signal is maintained. This is also the case with reception of a CW light by keep alive. The signal cutoff detector 101 is accordingly allowed to reliably generate an alarm. On the other hand, the out-of-synchronization detector 102 is also allowed to reliably generate an alarm when light is applied because it contains only a noise component. When a signal to a frequency phase-locked loop itself fails to exist in a case of an electric circuit failure, the detector is not allowed to generate an alarm. (Second Embodiment) In the first embodiment of the present invention, when a gain of an AGC amplifier or a limiter amplifier for supplying a data signal to a signal cutoff detector or a frequency phase-locked loop for reproducing a clock is large enough, a fixed amplitude can be maintained irrespective of variation of a light input level and even at the cutoff of light input, a fixed amplitude can be maintained by amplifying a thermal noise generated from a preamplifier or the like. In actual designing, however, a gain of an AGC amplifier or a limiter amplifier is set to be low to some extent giving preference to stable operation of the amplifier in many cases. In such a case, when the light input level goes below P4, for example, the AGC amplifier or the limiter amplifier can not maintain a predetermined amplitude as can be seen from FIG. 7 . The output of the autocorrelation detector therefore starts decreasing with P4 as a peak, so that from P1 to P3, an alarm can not be generated. When the light level further goes down to below P1, the detector again generates an alarm. On the other hand, when the light input level becomes lower than P2, the out-of-synchronization detector lacks a data amplitude necessary for stably operating the frequency phase-lock loop to be unable to operate stably. Therefore, there is a shortcoming that between the light input levels P1 and P2, a region is generated where an alarm can not be reliably generated. Also at the time of a noise derived from ASE when a light data signal is cut off or at the reception of CW in keep alive, a region where an alarm can not be reliably generated is generated between the light input levels P1 and P2 as shown in FIG. 8 . Such a shortcoming is overcome by the second embodiment of the present invention. Structure of a signal input cutoff detector according to the second embodiment of the present invention is shown in FIG. 6 . In the present embodiment, the signal input cutoff detector of the first embodiment is newly provided with a hysteresis amplifier 501 . The hysteresis amplifier 501 is an amplifier whose input and output relation has hysteresis characteristics. By setting the hysteresis amplifier 501 to have an appropriate hysteresis width, effects of noise power when applied light signal power is small can be reduced. In other words, when a superposed noise is less than the hysteresis width, an output of the hysteresis amplifier 501 remains unchanged, so that a noise applied to the autocorrelation detector 201 as a random pattern independent of a data signal will be reduced. Furthermore, since a mean value of a signal component draws near to zero with the decrease of a light input level, the output of the autocorrelation detector 201 will be decreased monotonously with the light input level as shown in FIG. 9 . Therefore, at the comparator 202 , it is only necessary to set one reference voltage (Vref1) at the time of determination of normality/abnormality. Since the out-of-synchronization detector has its operation unstable when the light input is below P2 similarly to the first embodiment, reliable generation of an alarm over all the regions of the light input levels P0 to P4 needs use of both the signal cutoff detector 101 and the out-of-synchronization detector 102 . It is clearly understood that at this time, the reference voltage (Vref1) is set such that an alarm generation region of the signal cutoff detector 101 and an alarm generation region of the out-of-synchronization detector 102 overlap with each other. Also at the time of a noise derived from ASE or keep alive, the signal cutoff detector 101 and the out-of-synchronization detector 102 should be both used to reliably generate an alarm as shown in FIG. 10 . Furthermore, the present embodiment enables abnormality occurring places to be grasped to some extent by monitoring outputs of the above-described two circuits in combination. Table therefor is shown in FIG. 11 . When the output of the signal input detector 101 causes generation of an alarm and the output of the out-of-synchronization detector 102 is unstable, for example, it can be seen that input to the photo receiver is cut off. (Third Embodiment) FIG. 13 is an example of a structure of a photo receiver using the signal input cutoff detector of the present invention. The photo receiver is structured to include a photo detector 10 and a preamplifier 11 for converting a light input signal into an electric signal, an AGC amplifier or limiter amplifier 12 for amplifying an output of the preamplifier 11 to have a predetermined amplitude, a frequency phase-locked loop 20 which contains a VCO and generates a clock synchronized with an output of the AGC amplifier or limiter amplifier 12 (data signal), a discrimination circuit 18 for discriminating the data signal by the clock, a signal cutoff detector 101 for detecting the data signal existing or not, an out-of-synchronization detector 102 responsive to a VCO control signal of the frequency phase-locked loop 20 for detecting out-of-synchronization, and an alarm processing circuit for processing an alarm from the signal cutoff detector 101 and an alarm from the out-of-synchronization detector 102 . As described in the foregoing, being provided with a signal cutoff detector and an out-of-synchronization detector to combine alarm outputs of both the detectors, the signal input cutoff detector according to the present invention enables reliable generation of an alarm against a possible failure at a photo receiver, thereby grasping abnormality occurring places to some extent. Although the invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodies within a scope encompassed and equivalents thereof with respect to the feature set out in the appended claims.

A photo receiver branches a data signal obtained by photoelectric conversion and supplies the signal to a signal cutoff detector. Depending on the degree of an autocorrelation of a data signal obtained by an autocorrelation detector, the signal cutoff detector detects abnormality/normality. Depending on a level of a control signal to a VCO contained in a frequency phase-locked loop for use in clock generation, an out-of-synchronization detector makes determination of abnormality/normality. Outputs of both the detectors are ORed at an alarm processor and when at least one of the detectors detects abnormality, the detector generates an alarm.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention is directed to a magnetic resonance apparatus. [0003] 2. Description of the Prior Art [0004] Magnetic resonance technology is a known technique for, among other things, acquiring images of the inside of the body of an examination subject. In a magnetic resonance apparatus, rapidly switched gradient fields that are generated by a gradient system are superimposed on a static basic magnetic field that is generated by a basic field magnet. The magnetic resonance apparatus also has a radio-frequency system that emits radio-frequency signals into the examination subject for triggering magnetic resonance signals and that picks up the triggered magnetic resonance signals, on the basis of which magnetic resonance images are produced. [0005] The magnetic resonance apparatus has an examination space containing an imaging volume wherein a region of the examination subject to be imaged is to be positioned for producing magnetic resonance images of that region. The positioning of the region to be imaged in the imaging volume is possible by displacement of a movable support mechanism with the examination subject placed thereon. [0006] The gradient system of the magnetic resonance apparatus includes a gradient coil arrangement that must be rigidly connected to the basic field magnet. To that end, German OS 197 22 481 discloses a magnetic resonance apparatus wherein a basic field magnet has a first surface and a rigidly installed gradient coil system with a second surface, the two surfaces facing toward one another and being spaced from one another. A noise reduction device for damping the oscillations of the gradient coil system and/or for stiffening the gradient coil system is arranged in contact with both surfaces. In one embodiment, the noise reduction device is formed of at least one pillow. Such a pillow preferably comprises an envelope and a core or a filling. In order to achieve an especially good noise-damping effect, the pillow is elastic and/or resilient and/or flexible. In the operating state of the magnetic resonance apparatus, the pillow lies tightly against the first and the second surfaces but is not rigidly connected to these surfaces. As a result, the gradient coil system can be more easily detached for maintenance or replacement (which requires the rigid connection to be dismantled. The pillow has an air-impermeable outside skin that is formed of welded plastic film. The outside skin is composed of PVC film, polyethylene film or some other film that is airtight and weldable. A foamed fill composed of an open-pore cellular material, for example polyurethane foam, is contained in the pillow. The fill of cellular material insures good noise damping as well as providing an adequate elasticity of the pillow when the air pressure in the pillow is approximately the same as the ambient air pressure. The pillow has a connection that can be fashioned as a valve. The pillow is thicker than the distance between the first and second surfaces when the pillow is not introduced into the magnetic resonance apparatus and the valve is open. When, with the valve open, this pillow is introduced into the magnetic resonance apparatus, then the fill of cellular material presses the outside skin against the first and second surfaces, so the gap between these surfaces is completely filled. A pillow with an airtight outside skin and a fill of cellular material can be easily introduced into the gap between the first and second surfaces and be removed therefrom when the air contained in the pillow is pumped out to such an extent that it is compressed to a thinner thickness by the ambient air pressure. In an alternative embodiment of the noise reduction device, the pillow be pumped to a slight over-pressure and/or it can be filled with some other gas or a fluid and/or the inner fill of cellular material can be omitted. [0007] In addition to a rigidly installed gradient coil system, moreover, U.S. Pat. No. 5,185,576 discloses a local gradient coil unit that is combined with a local radio-frequency antenna. The local gradient coil unit with the integrated local radio-frequency antenna is designed for a specific region of the examination subject, for example for the head of a patient. As a result, the local gradient coil unit can be implemented with smaller dimensions compared to the rigidly installed gradient coil system, yielding advantages in view of—among other things—gradient intensities that can be achieved and power demands made on the gradient amplifier that feeds the gradient coil unit. The local gradient coil unit with the integrated local radio-frequency antenna can be secured to the support mechanism such that the local gradient coil unit does not move relative to the support mechanism even during operation of the magnetic resonance apparatus despite the forces that act on it. SUMMARY OF THE INVENTION [0008] An object of the present invention is to provide a magnetic resonance apparatus wherein a locally introducible gradient coil unit can be flexibly fixed in the apparatus. [0009] The object is inventively achieved by in a magnetic resonance having a scanner unit with an examination space for placing at least a region of an examination subject therein, a gradient coil unit movable in a displacement direction at least in the examination space, a component of the scanner unit surrounding the examination space, and at least one pillow that can be arranged between the gradient coil unit and the component and which has an internal pressure that can be controlled for fixing the gradient coil unit relative to the component. [0010] The invention is based on the perception that the noise reduction device known, for example, from German OS 197 22 481 and fashioned as a pillow can also be advantageously employed in a magnetic resonance apparatus having a movable gradient coil unit (as opposed to the rigidly connected gradient coil unit with which the pillow is intended for use) for fixing such a movable gradient coil unit. The advantage of mechanical decoupling accompanied by noise reduction and reduction in the transmission of vibrations known from German OS 197 22 481 is retained, with, further advantages in conjunction with the movable gradient coil unit. Thus, the movable gradient coil unit can be remotely controlled rapidly and free of the need for actuation of a manual interlock, by means of an appropriate pump for controlling the internal pressure, allowing the movable coil unit to be fixed inside the examination space with infinite variation in the displacement direction, i.e. it can be fixed at arbitrary positions within the examination space. Fixing to what is always the same location, of course, is not precluded. [0011] Further, the fixing by means of the pillow is advantageous because—apart from an introduction of the pillow—neither existing components of the magnetic resonance apparatus that limit the examination space nor existing, movable gradient coil units need by modified for employing this type of fixing. [0012] In an embodiment, the pillow has an extent in the displacement direction roughly corresponding to the extent of the gradient coil unit. Particularly given a pillow that is fashioned for large-area placement and/or given utilization of a number of pillows due to the large seating surface, a high security against slippage of the gradient coil unit is achieved. [0013] In another embodiment, the magnetic resonance apparatus has a movable support mechanism that is displaceable on a guide mechanism of the magnetic resonance apparatus, and the movable gradient coil unit is displaceable on the same guide mechanism. In one version, the examination space has at least two openings disposed opposite one another, so that the support mechanism can be moved into the examination space proceeding from one opening and the movable gradient coil unit can be moved into the examination space proceeding from the other opening. A time-efficient utilization of the magnetic resonance apparatus can be achieved as a result, since the examination subject, for example a patient, can be placed on the support mechanism during the displacement of the gradient coil unit. After the patient has been placed thereon, the support mechanism together with the patient placed thereon is moved into the examination space, where the gradient coil unit is already waiting, correctly positioned and fixed. DESCRIPTION OF THE DRAWINGS [0014] The single Figure is a side sectional view of a magnetic resonance apparatus constructed in accordance with the principles of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0015] As an exemplary embodiment of the invention, the Figure shows a longitudinal section through a magnetic resonance apparatus having a movable gradient coil unit 60 displaceable in at least one travel direction 65 . The magnetic resonance apparatus has an essentially hollow-cylindrical, superconducting basic field magnet 10 for generating a static basic magnetic field. A gradient coil system 20 for generating gradient fields that is likewise essentially hollow-cylindrical is permanently installed in the cavity of the basic field magnet 10 . The permanently installed gradient coil system 20 has three gradient coils, shielding coils associated with the gradient coils, cooling devices and shim devices. An essentially hollow-cylindrical whole-body antenna 30 for emitting radio-frequency signals and for receiving magnetic resonance signals is permanently installed in the control cavity of the gradient coil system 20 . A central cavity of the whole-body antenna 30 essentially defines an examination space 40 in which at least a region of an examination subject, for example a patient can be placed. [0016] A displaceable support mechanism 50 makes it possible to introduce the examination subject placed on the support mechanism 50 into the examination space 40 from the left with reference to the longitudinal section shown in the Figure. The support mechanism 50 is seated so as to be displaceable on a guide mechanism 55 . At the foot end, the support mechanism 50 , the bearing mechanism 50 has a connection unit 52 to which—among other things—a conduit of a vacuum cushion can be connected. The patient is placed in a comfortable and stable position on a sheet on the cushion. Air is then extracted from the vacuum pillow (filled with styropore balls) via the conduit, so that the shape of the vacuum pillow stabilizes. [0017] The movable gradient coil unit 60 is displaceable at least in a part of the examination space 40 . For generating gradient fields, the gradient coil unit 60 has at least one gradient coil (up to three gradient coils) and, dependent on the use requirements, shielding coils belonging to the gradient coils, cooling devices and shim devices and/or is combined with a local radio-frequency antenna. Displacement of the gradient coil unit 60 can ensue manually as well with the assistance of a motorized drive. Like the support mechanism 50 , the movable gradient coil unit 60 is fashioned to be movable on the guide mechanism 55 , which is unproblematical particularly given a weight of the gradient coil unit 60 that is somewhat less than an approved load weight of the support mechanism 50 . Special measures have to be provided only given a weight of the gradient coil unit 60 of more than roughly 200 kg. The electrical connection lines and, if present, cooling supply lines 62 necessary for supplying the gradient coil unit 60 are conducted to the gradient coil unit 60 from the right. [0018] A pillow 70 or multiple pillows 70 distributed in circumferential direction is/are glued to the gradient coil unit 60 for fixing the gradient coil unit 60 at an arbitrary position within the whole-body antenna 30 . Each pillow 70 has a gastight outer skin 72 that is composed of two pieces of a PVC film that are welded to one another. A connection 76 fashioned with a valve 77 is introduced gastight at a location of the circumferential seam. The outer skin 72 surrounds a fill 74 of cellular material formed of an open-pore polyurethane foam that is planarly glued to the outer skin 72 . [0019] Given a displacement of the gradient coil unit 60 , each pillow 70 is evacuated and each valve 77 is closed. After the gradient coil unit 80 has been positioned as desired, the valve 77 is opened for fixing the gradient coil unit 60 against the whole-body antenna, so that roughly ambient air pressure prevails in the inside of each pillow 70 . The pillow 70 is dimensioned such that the outer skin 72 are pressed against the whole-body antenna 30 and the gradient coil unit 60 by the fill 74 of cellular material. The spacing between the whole-body antenna 30 and the gradient coil unit 60 is then completely filled, so that the gradient coil unit 60 is fixed and—at the same time—oscillations occurring during operation of the gradient coil unit 60 are effectively damped. [0020] Air is pumped out of each pillow 70 via the connection 76 for rendering the gradient coil unit 60 mobile. The ambient air pressure then compresses each pillow 70 , and each valve 77 is are closed so that the gradient coil unit 60 can again be moved. For the pumping, each connection 76 can be connected via a hose system 79 to the connection unit 52 at the connection point for the vacuum cushion. In a magnetic resonance apparatus that has no facilities for a vacuum cushion, a separate unit for pumping air can be connected to each pillow 70 . [0021] After setting a new position of the gradient coil unit 60 within the whole-body antenna 30 , each valve 77 is again opened, so that air flows into each pillow 70 . Each pillow 70 regains elasticity and thickness and thus fixes the gradient coil unit 60 in a press fit. [0022] In an alternative embodiment each pillow 70 is pumped to a slight over-pressure and/or each pillow 70 is filled with a gas other than air or with a liquid. It is also possible to omit the inner fill 74 of cellular material. [0023] Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.

A magnetic resonance has a scanner unit with an examination space for placing at least a region of an examination subject therein, a gradient coil unit movable in a displacement direction at least in the examination space, a component of the scanner unit surrounding the examination space, and at least one pillow that can be arranged between the gradient coil unit and the component and which has an internal pressure that can be controlled for fixing the gradient coil unit relative to the component.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of co-pending U.S. application Ser. No. 13/097,998 filed on Apr. 29, 2011 which, in turn, claims priority to U.S. Provisional Application No. 61/329,220, filed on Apr. 29, 2010, both of which are incorporated herein by reference in their entireties. FIELD OF THE INVENTION [0002] This invention relates to medical instruments and systems for creating a path or cavity in vertebral bone to receive bone cement to treat a vertebral compression fracture. The features relating to the methods and devices described herein can be applied in any region of bone or hard tissue where the tissue or bone is displaced to define a bore or cavity instead of being extracted from the body such as during a drilling or ablation procedure. In addition, the present invention also discloses methods and devices for ablating or coagulating tissues, including but not limited to ablating tumor tissue in vertebral and/or cortical bone. SUMMARY OF THE INVENTION [0003] Methods and devices described herein relate to improved creation of a cavity within bone or other hard tissue where the cavity is created by displacement of the tissue. In a first example, a method according to the present disclosure includes treating a vertebral body or other bone structure. In one variation, the method includes providing an elongate tool having a sharp tip configured for penetration into vertebral bone, the tool having an axis extending from a proximal end to a working end thereof, where the working end comprises at least a first sleeve concentrically located within a second sleeve and a third sleeve located concentrically about the second sleeve, where each sleeve comprises a series of slots or notches to limit deflection of the working end to a first curved configuration in a single plane and where the respective series of slots or notches are radially offset in each sleeve; advancing the working end through vertebral bone; causing the working end to move from a linear configuration to a curved configuration by translating the first sleeve relative to the second sleeve in an axial direction; and moving the working end in the curved configuration within the bone to create a cavity therein. Translating of the first sleeve relative to the second sleeve can include moving either sleeve or both sleeves in an axial direction. Additional variations include moving one or both sleeves in a rotational direction to produce relative axial displacement between sleeves. [0004] In an additional variation, the present devices include medical osteotome devices that can for treat a hard tissue (e.g., in a vertebral body) by mechanically displacing the hard tissue and/or applying therapeutic energy to ablate or coagulate tissue. For example, one such variation includes an osteotome type device that is coupled to a power supply and further includes a handle having an actuating portion and a connector for electrically coupling the osteotome device to the power supply; a shaft comprising a first sleeve located concentrically within a second sleeve, the shaft having a distal portion comprising a working end capable of moving between a linear configuration and an articulated configuration where the articulated configuration is limited to a single plane, and where each sleeve comprises a series of slots or notches to limit deflection of the working end to the articulated configuration, where the respective series of slots or notches are radially offset in adjacent sleeves, where a first conductive portion of the shaft is electrically coupleable to a first pole of the power supply; a sharp tip located at a distal tip of the first sleeve of the working end, the sharp tip adapted to penetrate bone within the vertebral body, where the distal tip is coupleable to a second pole of the power supply, such that when activated, current flows between a portion of the distal tip and the shaft; a non-conductive layer electrically isolating the first sleeve from the first conductive portion; and where the shaft and sharp tip have sufficient column strength such that application of an impact force on the handle causes the distal portion of the shaft and the distal tip to mechanically displace the hard tissue. The power supply can be coupled to the outer sleeve (either the second or third sleeve discussed herein.) [0005] Another variations of the method disclosed herein can include the application of energy between electrodes on the device to ablate tissues (e.g., tumor) or to perform other electrosurgical or mapping procedures within the tissue. In one such example for treating a vertebral body, the method can include providing an elongate tool having a sharp tip configured for penetration into vertebral bone, the tool having an axis extending from a proximal end to a working end thereof, where the working end comprises at least a first sleeve concentrically located within a second sleeve, where each sleeve comprises a series of slots or notches to limit deflection of the working end to a first curved configuration in a single plane and where the respective series of slots or notches are radially offset in adjacent sleeves, where a first conductive portion of the first sleeve is electrically coupled to a first pole of a power supply; advancing the working end through vertebral bone; causing the working end to move from a linear configuration to a curved configuration by translating the first sleeve relative to the second sleeve in an axial direction; and applying energy between the first conductive portion and a return electrode electrically coupled to a second pole of the energy supply to ablate or coagulate a region within the vertebral body. [0006] In variations of the method, moving the working end to from the linear configuration to the curved configuration can include moving the working end to move through a plurality of curved configurations. [0007] In an additional variation, causing the working end to move from a linear configuration to the curved configuration comprises actuating a handle mechanism to move the working end from the linear configuration to the curved configuration. The handle mechanism can be moved axially and/or rotationally as described herein. [0008] In one variation, actuating of the handle mechanism causes the working end to move to the first curved configuration without torquing the third sleeve. [0009] In additional variations, the working end of the osteotome or tool is spring biased to assume the linear configuration. [0010] The working end can move from the linear configuration to the curved configuration by applying a driving force or impact to the elongate tool wherein penetration in the cortical bone moves the working end from the linear configuration to the curved configuration. For example, as a hammering or impact force is applied to the working end, the interaction of the sharp tip against bone causes the working end to assume an articulated and/or curved configuration. Where further axial movement of the tool causes compression of the bone and creation of the cavity. [0011] The method can further include the use of one or more cannulae to introduce the tool into the target region. Such a cannula can maintain the tool in a straight or linear configuration until the tool advances out of the cannula or until the cannula is withdrawn from over the tool. [0012] As described herein, upon creation of the cavity, the method can further include the insertion of a filler material or other substance into the cavity. The filler material can be delivered through the tool or through a separate cannula or catheter. [0013] This disclosure also includes variations of devices for creating a cavity within bone or hard tissue. Such variations include devices for treating a vertebral body or other such structure. In one variation a device includes a handle having an actuating portion; a shaft comprising a first sleeve located concentrically within a second sleeve and a third sleeve located concentrically about the second sleeve, the shaft having a distal portion comprising a working end capable of moving between a linear configuration and an articulated configuration where the second articulated configuration is limited to a single plane, and where each sleeve comprises a series of slots or notches to limit deflection of the working end to the articulated configuration, where the respective series of slots or notches are radially offset in each sleeve; and a sharp tip located at a distal tip of the working end, the sharp tip adapted to penetrate vertebral bone within the vertebral body. [0014] In one variation, the devices described herein can include a configuration where the first sleeve is affixed to the second sleeve at the working end such that proximal movement of the first sleeve causes the working end to assume the articulated configuration. The sleeves can be affixed at any portion along their length via a mechanical fixation means (e.g., a pin or other fixation means), an adhesive, or one or more weld points. In some variations, fixation of the sleeves occurs at the working end so that movement of the inner or first sleeve causes the working end to assume the curved configuration. In some cases, the third sleeve can be affixed outside of the working end so long as when the first and second sleeves articulate, the third sleeve still articulates. [0015] Devices described herein can optionally include a force-limiting assembly coupled between the actuating portion and the first sleeve such that upon reaching a threshold force, the actuating portion disengages the first sleeve. In one variation, the force-limiting mechanism is adapted to limit force applied to bone when moving the working end from the first configuration toward the second configuration. [0016] In additional variations, devices for creating cavities in bone or hard tissue can include one or more spring elements that extending through the first sleeve, where the spring element is affixed to the shaft (within or about either the first, second, or third sleeve). Such spring elements cause the working end to assume a linear configuration in a relaxed state. [0017] In additional variations, a device can include an outer or third sleeve where the slots or notches (that allow deflection) are located on an exterior surface of the third sleeve. The exterior surface is typically the surface that faces outward from a direction of the curved configuration. This configuration allows for an interior surface (the surface located on the interior of the curved portion) to be smooth. As a result, if the device is withdrawn through tissue or a cannula or other introducer, the smooth surface on the interior of the curve minimizes the chance that the device becomes caught on the opening of the cannula or any other structure. [0018] Variations of the device can include one or more lumens that extend through the shaft and working end. These lumens can exit at a distal tip of the device or through a side opening in a wall of the device. The lumen can include a surface comprising a lubricious polymeric material. For example, the material can comprise any bio-compatible material having low frictional properties (e.g., TEFLON®, a polytetrafluroethylene (PTFE), FEP (Fluorinated ethylenepropylene), polyethylene, polyamide, ECTFE (Ethylenechlorotrifluoro-ethylene), ETFE, PVDF, polyvinyl chloride and silicone). [0019] As described herein, the devices can include any number of configurations to prevent rotation between adjacent sleeves but allow axial movement between the sleeves. For example, the sleeves can be mechanically coupled via a pin/slot or key/keyway configuration. In an additional variation, the sleeves can be non-circular to prevent rotation. [0020] In an additional variation, the disclosure includes various kits comprising the device described herein as well as a filler material (e.g., a bone cement or other bone filler material). [0021] Variations of the access device and procedures described above include combinations of features of the various embodiments or combination of the embodiments themselves wherever possible. [0022] The methods, devices and systems described herein can be combined with the following commonly assigned patent applications and provisional applications, the entirety of each of which is incorporated by reference herein: application Ser. No. 61/194,766, filed Sep. 30, 2008; application Ser. No. 61/104,380, filed Oct. 10, 2008; application Ser. No. 61/322,281, filed Apr. 8, 2010; application Ser. No. 12/571,174 filed Sep. 30, 2009; PCT Application number PCT/US2009/059113 filed Sep. 30, 2009; application Ser. No. 12/578,455 filed Oct. 13, 2009. BRIEF DESCRIPTION OF DRAWINGS [0023] FIG. 1 is a plan view of an osteotome of the invention. [0024] FIG. 2 is a side view of the osteotome of FIG. 1 . [0025] FIG. 3 is a cross sectional view of the osteotome of FIG. 1 . [0026] FIG. 4 is an enlarged sectional view of the handle of the osteotome of FIG. 1 . [0027] FIG. 5 is an enlarged sectional view of the working end of the osteotome of FIG. 1 . [0028] FIG. 6A is a sectional view of the working end of FIG. 5 in a linear configuration. [0029] FIG. 6B is a sectional view of the working end of FIG. 5 in a curved configuration. [0030] FIGS. 7A-7C are schematic sectional views of a method of use of the osteotome of FIG. 1 . [0031] FIG. 8 is another embodiment of an osteotome working end. [0032] FIG. 9 is another embodiment of an osteotome working end. [0033] FIG. 10 is another variation of an osteotome with an outer sleeve. [0034] FIG. 11 is a cut-away view of the working end of the osteotome of FIG. 10 . [0035] FIG. 12A is sectional view of another embodiment of working end, taken along line 12 A- 12 A of FIG. 11 . [0036] FIGS. 12B and 12C illustrate additional variations of preventing rotation between adjacent sleeves. [0037] FIG. 13 is sectional view of another working end embodiment similar to that of FIG. 11 . [0038] FIG. 14 is a cut-away perspective view of the working end of FIG. 13 . [0039] FIG. 15 illustrates a variation of an osteotome as described herein having electrodes on a tip of the device and another electrode on the shaft. [0040] FIG. 16 illustrates an osteotome device as shown in FIG. 15 after being advanced into the body and where current passes between electrodes. [0041] FIG. 17 illustrates a variation of a device as described herein further including a connector for providing energy at the working end of the device. [0042] FIGS. 18A and 18B illustrate a device having a sharp tip as disclosed herein where the sharp tip is advanceable from the distal end of the shaft. [0043] FIG. 19 shows a cross sectional view of the device illustrated in FIG. 18B and also illustrates temperature sensing elements located on device. [0044] FIG. 20 shows a variation of a device where the inner sleeve is extended from the device and where current is applied between the extended portion of the inner sleeve and the shaft to treat tissue. [0045] FIG. 21 illustrates a variation of a device as described herein further including an extendable helical electrode carried by the working end of the device. [0046] FIGS. 22A and 22B illustrate the device of FIG. 21 with the helical electrode in a non-extended position and an extended position. [0047] FIG. 23 illustrates the working end of the device of FIG. 21 in a vertebral body with the helical electrode delivering Rf energy to tissue for ablation or other treatments. DETAILED DESCRIPTION [0048] Referring to FIGS. 1-5 , an apparatus or osteotome 100 is shown that is configured for accessing the interior of a vertebral body and for creating a pathway in vertebral cancellous bone to receive bone cement. In one embodiment, the apparatus is configured with an extension portion or member 105 for introducing through a pedicle and wherein a working end 110 of the extension member can be progressively actuated to curve a selected degree and/or rotated to create a curved pathway and cavity in the direction of the midline of the vertebral body. The apparatus can be withdrawn and bone fill material can be introduced through a bone cement injection cannula. Alternatively, the apparatus 100 itself can be used as a cement injector with the subsequent injection of cement through a lumen 112 of the apparatus. [0049] In one embodiment, the apparatus 100 comprises a handle 115 that is coupled to a proximal end of the extension member 105 . The extension member 105 comprises an assembly of first (outer) sleeve 120 and a second (inner) sleeve 122 , with the first sleeve 120 having a proximal end 124 and distal end 126 . The second sleeve 122 has a proximal end 134 and distal end 136 . The extension member 105 is coupled to the handle 115 , as will be described below, to allow a physician to drive the extension member 105 into bone while contemporaneously actuating the working end 110 into an actuated or curved configuration (see FIG. 6 ). The handle 115 can be fabricated of a polymer, metal or any other material suitable to withstand hammering or impact forces used to drive the assembly into bone (e.g., via use of a hammer or similar device on the handle 115 ). The inner and outer sleeves are fabricated of a suitable metal alloy, such as stainless steel or NiTi. The wall thicknesses of the inner and outer sleeves can range from about 0.005″ to 0.010″ with the outer diameter the outer sleeve ranging from about 2.5 mm to 5.0 mm. [0050] Referring to FIGS. 1, 3 and 4 , the handle 115 comprises both a first grip portion 140 and a second actuator portion indicated at 142 . The grip portion 140 is coupled to the first sleeve 120 as will be described below. The actuator portion 142 is operatively coupled to the second sleeve 122 as will be described below. The actuator portion 142 is rotatable relative to the grip portion 140 and one or more plastic flex tabs 145 of the grip portion 140 are configured to engage notches 146 in the rotatable actuator portion 142 to provide tactile indication and temporary locking of the handle portions 140 and 142 in a certain degree of rotation. The flex tabs 145 thus engage and disengage with the notches 146 to permit ratcheting (rotation and locking) of the handle portions and the respective sleeve coupled thereto. [0051] The notches or slots in any of the sleeves can comprise a uniform width along the length of the working end or can comprise a varying width. Alternatively, the width can be selected in certain areas to effectuate a particular curved profile. In other variation, the width can increase or decrease along the working end to create a curve having a varying radius. Clearly, it is understood that any number of variations are within the scope of this disclosure. [0052] FIG. 4 is a sectional view of the handle showing a mechanism for actuating the second inner sleeve 122 relative to the first outer sleeve 120 . The actuator portion 142 of the handle 115 is configured with a fast-lead helical groove indicated at 150 that cooperates with a protruding thread 149 of the grip portion 140 of the handle. Thus, it can be understood that rotation of the actuation portion 142 will move this portion to the position indicated at 150 (phantom view). In one embodiment, when the actuator portion 142 is rotated a selected amount from about 45° to 720°, or from about 90° to 360°, the inner sleeve 122 is lifted proximally relative to the grip portion 140 and outer sleeve 120 to actuate the working end 110 . As can be seen in FIG. 4 the actuator portion 142 engages flange 152 that is welded to the proximal end 132 of inner sleeve 122 . The flange 152 is lifted by means of a ball bearing assembly 154 disposed between the flange 152 and metal bearing surface 155 inserted into the grip portion 140 of the handle. Thus, the rotation of actuator 142 can lift the inner sleeve 122 without creating torque on the inner sleeve. [0053] Now turning to FIGS. 5, 6A and 6B , it can be seen that the working end 110 of the extension member 105 is articulated by cooperating slotted portions of the distal portions of outer sleeve 120 and inner sleeve 122 that are both thus capable of bending in a substantially tight radius. The outer sleeve 120 has a plurality of slots or notches 162 therein that can be any slots that are perpendicular or angled relative to the axis of the sleeve. The inner sleeve 122 has a plurality of slots or notches indicated at 164 that can be on an opposite side of the assembly relative to the slots 162 in the outer sleeve 120 . The outer and inner sleeves are welded together at the distal region indicated at weld 160 . It thus can be understood that when inner sleeve 122 is translated in the proximal direction, the outer sleeve will be flexed as depicted in FIG. 6B . It can be understood that by rotating the actuator handle portion 142 a selected amount, the working end can be articulated to a selected degree. [0054] FIGS. 4, 5, 6A and 6B further illustrate another element of the apparatus that comprises a flexible flat wire member 170 with a proximal end 171 and flange 172 that is engages the proximal side of flange 152 of the inner sleeve 122 . At least the distal portion 174 of the flat wire member 170 is welded to the inner sleeve at weld 175 . This flat wire member thus provides a safety feature to retain the working end in the event that the inner sleeve fails at one of the slots 164 . [0055] Another safety feature of the apparatus comprises a torque limiter and release system that allows the entire handle assembly 115 to freely rotate—for example if the working end 110 is articulated, as in FIG. 6B , when the physician rotates the handle and when the working end is engaged in strong cancellous bone. Referring to FIG. 4 , the grip portion 142 of the handle 115 engages a collar 180 that is fixed to a proximal end 124 of the outer sleeve 120 . The collar 180 further comprises notches 185 that are radially spaced about the collar and are engaged by a ball member 186 that is pushed by a spring 188 into notches 185 . At a selected force, for example a torque ranging from greater than about 0.5 inch*lbs but less that about 7.5 inch*lbs, 5.0 inch*lbs or 2.5 inch*lbs, the rotation of the handle 115 overcomes the predetermined limit. When the torque limiter assembly is in its locked position, the ball bearing 186 is forced into one of the notches 185 in the collar 180 . When too much torque is provided to the handle and outer sleeve, the ball bearing 186 disengages the notch 185 allowing the collar 180 to turn, and then reengages at the next notch, releasing anywhere from 0.5 inch*lbs to 7.5 inch*lbs of torque. [0056] Referring to FIGS. 6A and 6B , it can be understood that the inner sleeve 122 is weakened on one side at its distal portion so as to permit the inner sleeve 122 to bend in either direction but is limited by the location of the notches in the outer sleeve 120 . The curvature of any articulated configuration is controlled by the spacing of the notches as well as the distance between each notch peak. The inner sleeve 122 also has a beveled tip for entry through the cortical bone of a vertebral body. Either the inner sleeve or outer sleeve can form the distal tip. [0057] Referring to FIGS. 7A-7C , in one variation of use of the device, a physician taps or otherwise drives a stylet 200 and introducer sleeve 205 into a vertebral body 206 typically until the stylet tip 208 is within the anterior ⅓ of the vertebral body toward cortical bone 210 ( FIG. 7A ). Thereafter, the stylet 200 is removed and the sleeve 205 is moved proximally ( FIG. 7B ). As can be seen in FIG. 7B , the tool or osteotome 100 is inserted through the introducer sleeve 205 and articulated in a series of steps as described above. The working end 110 can be articulated intermittently while applying driving forces and optionally rotational forces to the handle 115 to advance the working end through the cancellous bone 212 to create path or cavity 215 . The tool is then tapped to further drive the working end 110 to, toward or past the midline of the vertebra. The physician can alternatively articulate the working end 110 , and drive and rotate the working end further until imaging shows that the working end 100 has created a cavity 215 of an optimal configuration. Thereafter, as depicted in FIG. 7C , the physician reverses the sequence and progressively straightens the working end 110 as the extension member is withdrawn from the vertebral body 206 . Thereafter, the physician can insert a bone cement injector 220 into the path or cavity 215 created by osteotome 100 . FIG. 7C illustrates a bone cement 222 , for example a PMMA cement, being injected from a bone cement source 225 . [0058] In another embodiment (not shown), the apparatus 100 can have a handle 115 with a Luer fitting for coupling a bone cement syringe and the bone cement can be injected through the lumen 112 of the apparatus. In such an embodiment FIG. 9 , the lumen can have a lubricious surface layer or polymeric lining 250 to insure least resistance to bone cement as it flows through the lumen. In one embodiment, the surface or lining 250 can be a fluorinated polymer such as TEFLON® or polytetrafluroethylene (PTFE). Other suitable fluoropolymer resins can be used such as FEP and PFA. Other materials also can be used such as FEP (Fluorinated ethylenepropylene), ECTFE (Ethylenechlorotrifluoro-ethylene), ETFE, Polyethylene, Polyamide, PVDF, Polyvinyl chloride and silicone. The scope of the invention can include providing a polymeric material having a static coefficient of friction of less than 0.5, less than 0.2 or less than 0.1. [0059] FIG. 9 also shows the extension member or shaft 105 can be configured with an exterior flexible sleeve indicated at 255 . The flexible sleeve can be any commonly known biocompatible material, for example, the sleeve can comprise any of the materials described in the preceding paragraph. [0060] As also can be seen in FIG. 9 , in one variation of the device 100 , the working end 110 can be configured to deflect over a length indicated at 260 in a substantially smooth curve. The degree of articulation of the working end 100 can be at least 45°, 90°, 135° or at least 180° as indicated at 265 ( FIG. 9 ). In additional variations, the slots of the outer 120 and inner sleeves 120 can be varied to produce a device having a radius of curvature that varies among the length 260 of the device 100 . [0061] In another embodiment of the invention, the inner sleeve can be spring loaded relative the outer sleeve, in such a way as to allow the working end to straighten under a selected level of force when pulled in a linear direction. This feature allows the physician to withdraw the assembly from the vertebral body partly or completely without further rotation the actuating portion 142 of handle 115 . In some variations, the force-limiter can be provided to allow less than about 10 inch*lbs of force to be applied to bone. [0062] In another embodiment shown in FIG. 8 , the working end 110 is configured with a tip 240 that deflects to the position indicated at 240 ′ when driven into bone. The tip 240 is coupled to the sleeve assembly by resilient member 242 , for example a flexible metal such as stainless steel or NiTi. It has been found that the flexing of the tip 240 causes its distal surface area to engage cancellous bone which can assist in deflecting the working end 110 as it is hammered into bone. [0063] In another embodiment of the invention (not shown), the actuator handle can include a secondary (or optional) mechanism for actuating the working end. The mechanism would include a hammer-able member with a ratchet such that each tap of the hammer would advance assembly and progressively actuate the working end into a curved configuration. A ratchet mechanism as known in the art would maintain the assembly in each of a plurality of articulated configurations. A release would be provided to allow for release of the ratchet to provide for straightening the extension member 105 for withdrawal from the vertebral body. [0064] FIGS. 10 and 11 illustrate another variation of a bone treatment device 400 with a handle 402 and extension member 405 extending to working end 410 having a similar construction to that FIGS. 1 to 6B . The device 400 operates as described previously with notched first (outer) sleeve 120 and cooperating notched second (inner) sleeve 122 . However, the variation shown in FIGS. 10 and 11 also includes a third concentric notched sleeve 420 , exterior to the first 120 and second 122 sleeves. The notches or slots in sleeve 420 at the working end 410 permit deflection of the sleeve as indicated at 265 in FIG. 11 . [0065] FIG. 10 also illustrates the treatment device 400 as including a luer fitting 412 that allows the device 402 to be coupled to a source of a filler material (e.g., a bone filler or bone cement material). The luer can be removable from the handle 402 to allow application of an impact force on the handle as described above. Moreover, the luer fitting 402 can be located on the actuating portion of the handle, the stationary part of the handle or even along the sleeve. In any case, variations of the device 400 permit coupling the filler material with a lumen extending through the sleeves (or between adjacent sleeves) to deposit filler material at the working end 410 . As shown by arrows 416 , filler material can be deposited through a distal end of the sleeves (where the sharp tip is solid) or can be deposited through openings in a side-wall of the sleeves. Clearly, variations of this configuration are within the scope of those familiar in the field. [0066] In some variations, the third notched sleeve 420 is configured with its smooth (non-notched) surface 424 disposed to face inwardly on the articulated working end ( FIG. 11 ) such that a solid surface forms the interior of the curved portion of the working end 410 . The smooth surface 424 allows withdrawal of the device 110 into a cannula or introducer 205 without creating a risk that the slots or notches become caught on a cannula 205 (see e.g., FIG. 7B ). [0067] As shown in FIGS. 10-11 , the third (outermost) sleeve 420 can extend from an intermediate location on the extension member 405 to a distal end of the working end 410 . However, variations of the device include the third sleeve 420 extending to the handle 402 . However, the third sleeve 420 is typically not coupled to the handle 402 so that any rotational force or torque generated by the handle 402 is not directly transmitted to the third sleeve 420 . [0068] In one variation, the third sleeve 420 is coupled to the second sleeve 120 at only one axial location. In the illustrated example shown in FIG. 11 , the third sleeve 420 is affixed to second sleeve 420 by welds 428 at the distal end of the working end 410 . However, the welds or other attachment means (e.g., a pin, key/keyway, protrusion, etc.) can be located on a medial part of the sleeve 420 . The sleeve 420 can be fabricated of any bio-compatible material. For example, in one variation, the third sleeve is fabricated form a 3.00 mm diameter stainless steel material with a wall thickness of 0.007″. The first, second and third sleeves are sized to have dimensions to allow a sliding fit between the sleeves. [0069] FIG. 12A is a sectional view of extension member 405 of another variation, similar to that shown in FIGS. 10-11 . However, the variation depicted by FIG. 12A comprises non-round configurations of concentric slidable sleeves (double or triple sleeve devices). This configuration limits or prevents rotation between the sleeves and allows the physician to apply greater forces to the bone to create a cavity. While FIG. 12A illustrates an oval configuration, any non-round shape is within the scope of this disclosure. For example, the cross-sectional shape can comprise a square, polygonal, or other radially keyed configuration as shown in FIGS. 12B and 12C . As shown in FIG. 12C the sleeves can include a key 407 and a receiving keyway 409 to prevent rotation but allow relative or axial sliding of the sleeves. The key can comprise any protrusion or member that slides within a receiving keyway. Furthermore, the key can comprise a pin or any raised protrusion on an exterior or interior of a respective sleeve. In this illustration, only the first 122 and second 120 sleeves are illustrated. However, any of the sleeves can be configured with the key/keyway. Preventing rotation between sleeves improves the ability to apply force to bone at the articulated working end. [0070] FIGS. 13-14 illustrate another variation of a working end 410 of an osteotome device. In this variation, the working end 410 includes one or more flat spring elements 450 , 460 a, 460 b, 460 c, 460 d, that prevent relative rotation of the sleeves of the assembly thus allowing greater rotational forces to be applied to cancellous bone from an articulated working end. The spring elements further urge the working end assembly into a linear configuration. To articulate the sleeves, a rotational force is applied to the handle as described above, once this rotational force is removed, the spring elements urge the working end into a linear configuration. As shown in FIG. 13 , one or more of the spring elements can extend through the sleeves for affixing to a handle to prevent rotation. Furthermore, the distal end 454 of flat spring element 450 is fixed to sleeve assembly by weld 455 . Thus, the spring element is fixed at each end to prevent its rotation. Alternate variations include one or more spring elements being affixed to the inner sleeve assembly at a medial section of the sleeve. [0071] As shown in FIGS. 13-14 , variations of the osteotome can include any number of spring elements 460 a - 460 d. These additional spring elements 460 a - 460 d can be welded at either a proximal or distal end thereof to an adjacent element or a sleeve to allow the element to function as a leaf spring. [0072] In an additional variation, the osteotome device can include one or more electrodes 310 , 312 as shown in FIG. 15 . In this particular example, the device 300 includes spaced apart electrodes having opposite polarity to function in a bi-polar manner. However, the device can include a monopolar configuration. Furthermore, one or more electrodes can be coupled to individual channels of a power supply so that the electrodes can be energized as needed. Any variation of the device described above can be configured with one or more electrodes as described herein. [0073] FIG. 16 illustrates an osteotome device 300 after being advanced into the body as discussed above. As shown by lines 315 representing current flow between electrodes, when required, the physician can conduct RF current between electrodes 310 and 312 to apply coagulative or ablative energy within the bone structure of the vertebral body (or other hard tissue). While FIG. 16 illustrates RF current 315 flow between electrodes 310 and 312 , variations of the device can include a number of electrodes along the device to apply the proper therapeutic energy. Furthermore, an electrode can be spaced from the end of the osteotome rather than being placed on the sharp tip as shown by electrode 310 . In some variations, the power supply is coupled to the inner sharp tip or other working end of the first sleeve. In those variations with only two sleeves, the second pole of the power supply is coupled with the second sleeve (that is the exterior of the device) to form a return electrode. However, in those variations having three sleeves, the power supply can alternatively be coupled with the third outer sleeve. In yet additional variations, the second and third sleeves can both function as return electrodes. However, in those devices that are monopolar, the return electrode will be placed outside of the body on a large area of skin. [0074] FIGS. 17 to 20 illustrate another variation of an articulating probe or osteotome device 500 . In this variation, the device 500 includes a working end 505 that carries one or more RF electrodes that can be used to conduct current therethrough. Accordingly, the device can be used to sense impedance of tissue, locate nerves, or simply apply electrosurgical energy to tissue to coagulate or ablate tissue. In one potential use, the device 500 can apply ablative energy to a tumor or other tissue within the vertebra as well as create a cavity. [0075] FIGS. 17, 18A, 18B and 19 , illustrate a variation of the device 500 as having a handle portion 506 coupled to a shaft assembly 510 that extends along axis 512 to the articulating working end 505 . The articulating working end 505 can be actuatable as described above. In addition, FIG. 17 shows that handle component 514 a can be rotated relative to handle component 514 b to cause relative axial movement between a first outer sleeve 520 and second inner sleeve 522 ( FIG. 19 ) to cause the slotted working ends of the sleeve assembly to articulate as described above. The working end 505 of FIG. 19 shows two sleeves 520 and 522 that are actuatable to articulate the working end, but it should be appreciated that a third outer articulating sleeve can be added as depicted above. In one variation, the articulating working end can articulate 90° by rotating handle component 514 a between ¼ turn and ¾ turn. The rotating handle component 514 a can include detents at various rotational positions to allow for controlled hammering of the working end into bone. For example, the detents can be located at every 45° rotation or can be located at any other rotational increment. [0076] FIG. 17 depict an RF generator 530 A and RF controller 530 B connectable to an electrical connector 532 in the handle component 514 a with a plug connector indicated at 536 . The RF generator is of the type known in the art for electrosurgical ablation. The outer sleeve 520 comprises a first polarity electrode indicated at 540 A (+). However, any energy modality can be employed with the device. [0077] FIGS. 18A and 18B illustrate yet another variation of a working end of a device for creating cavities in hard tissue. As shown, the device 500 can include a central extendable sleeve 550 with a sharp tip 552 that is axially extendable from passageway 554 of the assembly of first and second sleeves 520 and 522 ( FIG. 19 ). The sleeve 550 can also include a second polarity electrode indicated at 540 B (−). Clearly, the first and second electrodes will be electrically insulated from one another. In one variation, and as shown in FIG. 19 , the sleeve assembly can carry a thin sleeve 555 or coating of an insulative polymer such as PEEK to electrically isolate the first polarity electrode 540 A (+) from the second polarity electrode 540 B (−). The electrode can be deployed by rotating knob 558 on the striking surface of handle component 514 a ( FIG. 17 ). The degree of extension of central sleeve 550 can optionally be indicated by a slider tab 557 on the handle. In the illustrated variation, the slider tab is located on either side of handle component 514 a ( FIG. 17 ). Sleeve 550 can be configured to extend distally beyond the assembly of sleeves 520 and 522 a distance of about 5 to 15 mm. [0078] Referring to FIG. 19 , the central extendable sleeve 550 can have a series of slots in at least a distal portion thereof to allow it to bend in cooperation with the assembly of first and second sleeves 520 and 522 . In the embodiment shown in FIG. 18B , the central sleeve 550 can optionally include a distal portion that does not contain any slots. However, additional variations include slots on the distal portion of the sleeve. [0079] FIG. 19 further depicts an electrically insulative collar 560 that extends length A to axially space apart the first polarity electrode 540 A (+) from the second polarity electrode 540 B (−). The axial length A can be from about 0.5 to 10 mm, and usually is from 1 to 5 mm. The collar can be a ceramic or temperature resistant polymer. [0080] FIG. 19 also depicts a polymer sleeve 565 that extends through the lumen in the center of electrode sleeve 550 . The polymer sleeve 565 can provide saline infusion or other fluids to the working end and/or be used to aspirate from the working end when in use. The distal portion of sleeve 550 can include one or more ports 566 therein for delivering fluid or aspirating from the site. [0081] In all other respects, the osteotome system 500 can be driven into bone and articulated as described above. The electrodes 540 A and 540 B are operatively coupled to a radiofrequency generator as is known in the art for applying coagulative or ablative electrosurgical energy to tissue. In FIG. 20 , it can be seen that RF current 575 is indicated in paths between electrodes 540 A and 540 B as shown by lines 575 . RF generator 530 A and controller 530 B for use with the devices described herein can include any number of power settings to control the size of targeted coagulation or ablation area. For example, the RF generator and controller can have Low (5 watts), medium (15 Watts) and High (25 watts) power settings. The controller 530 B can have a control algorithm that monitors the temperature of the electrodes and changes the power input in order to maintain a constant temperature. At least one temperature sensing element (e.g., a thermocouple) can be provided on various portions of the device. For example, and as shown in FIG. 19 , a temperature sensing element 577 can be provided at the distal tip of sleeve 550 tip while a second temperature sensing element 578 can be provided proximal from the distal tip to provide temperature feedback to the operator to indicate the region of ablated tissue during the application of RF energy. In one example, the second temperature sensing element was located approximately 15 to 20 mm from the distal tip. [0082] FIG. 21 illustrates another variation of articulating osteotome 600 with RF ablation features. Variations of the illustrated osteotome 600 can be similar to the osteotome of FIGS. 17-18B . In this variation, the osteotome 600 has a handle 602 coupled to shaft assembly 610 as described above. The working end 610 again has an extendable assembly indicated at 615 in FIG. 21 that can be extended by rotation of handle portion 622 relative to handle 602 . The osteotome can be articulated as described previously by rotating handle portion 620 relative to handle 602 . [0083] FIGS. 22A-22B are views of the working end 610 of FIG. 21 in a first non-extended configuration ( FIG. 22A ) and a second extended configuration ( FIG. 22B ). As can be seen in FIGS. 22A-22B , the extension portion 615 comprises an axial shaft 624 together with a helical spring element 625 that is axially collapsible and extendible. In one embodiment, the shaft can be a tube member with ports 626 fluidly coupled to a lumen 628 therein. In some variations, the ports can carry a fluid to the working end or can aspirate fluid from the working end. [0084] In FIGS. 22A-22B , it can be seen that axial shaft 624 , helical spring element 625 together with sharp tip 630 comprise a first polarity electrode (+) coupled to electrical source 530 A and controller 530 B as described previously. An insulator 632 separates the helical spring 625 electrode from the more proximal portion of the sleeve which comprises opposing polarity electrode 640 (−). The RF electrodes can function as described above (see FIG. 20 ) to ablate tissue or otherwise deliver energy to tissue. [0085] In one variation, the extension portion 615 can extend from a collapsed spring length of 2 mm, 3 mm, 4 mm or 5 mm to an extended spring length of 6 mm, 7 mm, 8 mm, 9 mm 10 mm or more. In the working end embodiment 615 in FIG. 22B , the spring can comprise a flat rectangular wire that assists in centering the spring 625 about shaft 624 but still can collapse to short overall length, with the flat surfaces of rectangular wire oriented for stacking. However, other variations are within the scope of the variations described herein. [0086] The use of the spring 625 as an electrode provides significant improvements in delivering energy. This spring provides (i) greatly increased electrode surface area and (ii) a very greatly increased length of relatively sharp edges provided by the rectangular wire—which provides for edges. Because the edges provide low surface area the concentration or density of RF current is greater at the edges and allows for theh RF current to jump or arc. Both these aspects of the invention—increased electrode surface area and increased electrode edge length—allow for much more rapid tissue ablation. [0087] In one aspect of the invention, the surface area of the spring electrode 625 can be at least 40 mm 2 , at least 50 mm 2 , or at least 60 mm 2 over the spring electrode lengths described above. [0088] In another aspect of the invention, the total length of the 4 edges of rectangular wire spring can be greater than 50 mm, greater than 100 mm or greater than 150 mm over the spring electrode lengths described above. [0089] In one example used in testing, an osteotome 600 (as in FIG. 21-22B ) was configured with a helical spring that had a collapsed length of 1.8 mm and an extended length of 7.5 mm. In this embodiment, the surface area of the spring electrode 625 when extended was 64.24 mm 2 and the total length of the electrodes edges was 171.52 mm (four edges at 42.88 mm per edge). [0090] In a comparison test, a first osteotome without a helical electrode was compared against a second osteotome 600 with a helical electrode as in FIG. 22B . These devices were evaluated at different power levels and different energy delivery intervals to determine volume of ablation. The working ends of the devices had similar dimensions excepting for the helical spring electrode. In Chart A below, RF energy was delivered at a low power setting of 5 Watts. It can be seen in Chart A that at a treatment interval of 120 seconds and 5 W, the volume of ablation was about 3 times faster with the helical electrode compared to the working end without the helical electrode (1.29 cc vs. 0.44 cc). [0091] Another comparison test of the same first osteotome 500 ( FIG. 18B ) and second osteotome 600 with a helical electrode ( FIG. 22B ) were evaluated at higher 15 Watt power level. As can be seen in Chart B, RF energy at a treatment interval of 25 seconds and 15 W, the volume of ablation was again was about 3 times faster with the helical electrode compared to the working end without the helical electrode (1.00 cc vs. 0.37 cc). In Chart B, the device without the helical electrode impeded out before 60 seconds passed, so that data was not provided. The testing shows that the helical electrode is well suited for any type of tissue or tumor ablation, with a 60 second ablation resulting in 1.63 cc of ablated tissue. [0092] FIG. 23 schematically illustrates the osteotome 600 in use in a vertebral body, wherein the RF current between the electrodes 625 and 640 ablate a tissue volume indicated at 640 . [0093] Although particular embodiments of the present invention have been described above in detail, it will be understood that this description is merely for purposes of illustration and the above description of the invention is not exhaustive. Specific features of the invention are shown in some drawings and not in others, and this is for convenience only and any feature may be combined with another in accordance with the invention. A number of variations and alternatives will be apparent to one having ordinary skills in the art. Such alternatives and variations are intended to be included within the scope of the claims. Particular features that are presented in dependent claims can be combined and fall within the scope of the invention. The invention also encompasses embodiments as if dependent claims were alternatively written in a multiple dependent claim format with reference to other independent claims.

Methods and devices that displace bone or other hard tissue to create a cavity in the tissue. Where such methods and devices rely on a driving mechanism for providing moving of the device to form a profile that improves displacement of the tissue. These methods and devices also allow for creating a path or cavity in bone for insertion of bone cement or other filler to treat a fracture or other condition in the bone. The features relating to the methods and devices described herein can be applied in any region of bone or hard tissue where the tissue or bone is displaced to define a bore or cavity instead of being extracted from the body such as during a drilling or ablation procedure.

CROSS REFERENCE TO RELATED APPLICATIONS This is a Continuation-in-Part application of U.S. patent application Ser. No. 09/031,245, filed Feb. 26, 1998, inventors Patton et al., for A SYSTEM AND METHOD OF MANAGING A PSYCHOLOGICAL STATE OF AN INDIVIDUAL USING IMAGES now U.S. Pat. No. 6,102,846. FIELD OF THE INVENTION This invention relates in general to the management of a physiological and/or psychological state of an individual and more particularly to the management of the physiological and/or psychological state of an individual through the use of images which have been customized for use by the individual and which can be part of a self-help process. BACKGROUND OF THE INVENTION The physical, emotional and mental well-being of an individual can contribute greatly to the quality of life of that individual. In our hyperactive, hyperkinetic world, stress results in numerous physical reactions, such as, headache, muscle tension, dizziness or sleeplessness, weight gain, chronic coughing, nervous ticks, stomach upset and shortness of breath. Job stress alone is estimated to cost American business $300,000,000,000 annually. Stress is the response of the body and/or mind to a demand placed upon it. Stress can be caused by major events in one's life, such as, death of a loved one, marital breakup, personal injury or sickness, and job loss. Stress can also result from our day-to-day hectic style of living, where one attempts to excel simultaneously at being a super employee, a super parent, a super spouse, and a super citizen. Unless chronic stress is controlled, one puts oneself at risk for a host of serious problems, such as, heart disease, stroke, migraines, muscle and nerve disorders. The typical path to obtain relief from stress is to visit one's doctor. Stress conditions result in up to 70% of all doctor's visits. Typically, drugs are prescribed to relieve stress. One stress reducing medication alone accounts for $6,000,000 per day in sales. Thus, alternative approaches to traditional medicine have become increasingly popular. Resort to Eastern religions, transcendental meditation, and biofeedback techniques have been proposed to empower the individual to reduce stress without the potential deleterious effects of powerful and expensive prescription drugs or invasive surgery. It has been proposed to use images for the purpose of optimizing one's physiological and psychological state. There are several reasons for this. (1) It has been shown that one can measure a reliable physiological response for images that differ in valence and arousal. It has been demonstrated that images rated differently with respect to perceived activation and pleasantness elicited physiological responses of different magnitude. Thus, magnitude of the skin conductance response correlated with perceived arousal level produced by pictorial stimuli. At the same time heart rate acceleration during first 4 to 5 seconds of image presentation reflected “valence” or degree of perceived pleasantness of an image. Other physiological parameters that reflect an individual's physiological reactions to images have also been demonstrated. These results imply that, for an individual viewer, images can potentially be classified based on one's physiological reactions in terms of emotional arousal. (2) Imagery is known to be able to change a person's state. Paintings, movies, pictures are constantly affecting our mood and performance level. Power of visualization and affective content determine effective use of imagery in therapeutic sessions. Experimental research has also shown that presentation of images of similar content may cause significant shifts in physiological reactions. (3) Digital imaging technology provides an almost instant access to image databases through the internet. Moreover, the potentially unlimited degree of digital manipulation makes images very attractive means of interaction and communication. Images can be easily transformed to alter or enhance people's preferences, i.e., for hue, saturation, depth, aesthetic feelings, etc. Image transformation by itself can provide biofeedback information to the user to facilitate learning how to control one's physiological and emotional state, e.g., stress. Following are several proposals to use images as a means of changing one's state that have not proven to be entirely successful. U.S. Pat. No. 5,465,729, issued Nov. 14, 1995, inventors Bittman et al. and U.S. Pat. No. 5,343,871, issued Sep. 6, 1994, inventors Bittman et al., disclose the use of measurements of electrophysiological quantities to control a presentation to a subject of a series of prestored audio-visual sequences. U.S. Pat. No. 3,855,998, issued Dec. 24, 1974, inventor Hidalgo-Briceno discloses an entertainment device that includes sensing means connected to the user for sensing galvanic skin response and brain theta waves. According to a given measured state of a user the device provides a given type of predetermined audio-visual stimulation to the user for a timed interval to hold one in or move one toward a desired state. At the end of the interval, the user's state is again measured and a further timed audio-visual response according to the measured state is presented to the user. U.S. Pat. No. 5,596,994, issued Jan. 28, 1997, inventor Bro, discloses an automated and interactive positive motivation system that allows a health care professional to produce and send a series of motivational messages to a client to change or reinforce a specific behavioral pattern. U.S. Pat. No. 5,304,112, issued Apr. 19, 1994, inventors Mrklas et al., discloses an integrated stress reduction system which detects the stress level of a subject and displays a light pattern reflecting the relationship between the subject's stress level and a target level. The system also provides relaxing visual, audio, tactile, environmental, and other effects to aid the subject in reducing one's stress level to the target level. U.S. Pat. No. 4,632,126, issued Dec. 30, 1986, inventor Aguilar, discloses a biofeedback technique which permits simultaneous, preferably redundant, visual and auditory presentation on a color TV of any intrinsically motivating stimuli together with continuous information pertaining to the physiological parameter to be controlled. As the subject changes a certain physiological parameter, the image and sound become clearer if the change occurs in the desired direction. U.S. Pat. No. 5,253,168, issued Oct. 12, 1993, inventor Berg, discloses a system for allowing an individual to express one's self in a creative manner by using biofeedback signals to direct imaging and audio devices. U.S. Pat. No. 5,676,138, issued Oct. 14, 1997, inventor Zawalinski, discloses a multimedia computerized system for detecting emotional responses of human beings and changes thereof over time. U.S. Pat. No. 5,047,930, issued Sep. 10, 1991, inventors Marten, et al., discloses methods of analyzing physiological signals from a subject and analyzing them using pattern recognition techniques to determine a particular sleep state of the subject. Use of any associated feedbacks is not disclosed. The following papers discuss various emotional responses and physiological responses of subjects to viewing images. Affective judgement and psychophysiological response: dimensional covariation in the evaluation of pictorial stimuli; by: Greenwald, Cook and Lang; Journal of Pyschophysiology 3 (1989), pages 51-64. Remembering Pictures: Pleasure and Arousal in Memory, by: Bradley, Greenwald, Petry and Lang; Journal of Experimental Psychology, Learning Memory and Cognition; 1992, Vol. 18, No. 2, pages 379-390. Looking at Pictures: Affective, facial, visceral, and behavioral reactions; by: Lang, Greenwald, Bradley, and Hamm, Psychophysiology, 30 (1993), pages 261-273. Picture media and emotion: Effects of a sustained affective context; by: Bradley, Cuthbert, and Lang, Psychophysiology, 33 (1996), pages 662-670. Emotional arousal and activation of the visual cortex: An fMRI analysis; by: Lang, Bradley, Fitzsimmons, Cuthbert, Scott, Bradley, Moulder, and Nangia; Psychophysiology, 25 (1998), pages 199-210. The techniques disclosed in the above references have the following disadvantages. 1. There is no development of a personal image profile of an individual so as to provide for customized images which are specifically tailored for the individual so as to move the individual to a desired physiological and/or psychological state. This is important since an image which is restful for some may be stressful for others. 2. The images or other stimuli for inducing change in state in an individual are preselected by someone other than the user. The selection is often based on the effect of the images on a large number of subjects rather than being personalized for the individual. 3. Where measurement of physiological parameters are used as part of the state change technique, the measurement devices are often large and not very portable and therefore not conducive for use at work, at home or during travel. SUMMARY OF THE INVENTION According to the present invention there is provided a solution to the problems referred to above. According to a feature of the present invention there is provided a method for classifying images according to features that are relevant to potential therapeutic effect, comprising: providing an image; and classifying said image according to one or more of the following classes, landscapes, people-activity, people-expression, people-type, animals, color (dominant hue(s)), direction of light, type of light, distance, travel/offset(direction of motion/travel). ADVANTAGEOUS EFFECT OF THE INVENTION The present invention has the following advantages. 1. An individual is profiled to provide customized images which are specifically tailored for the individual to move the individual to a desired physiological and/or psychological state. 2. The images or other stimuli for inducing change in the state of an individual are not preselected by someone other than the user, but rather by the user. 3. A portable device is used to measure physiological parameters to predict an individual's state. The portable device is conducive for use at work, at home, during travel, or during exercise. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are flow diagrams useful in explaining the present invention. FIGS. 3-5 are diagrammatic views illustrating several embodiments of a portable physiological sensor monitor. FIGS. 6-11 are graphical views useful in explaining certain aspects of the present invention. FIGS. 12 and 13 are diagrammatic views useful in explaining other aspects of the present invention. FIG. 14 is a block diagram of the system of the present invention. DETAILED DESCRIPTION OF THE INVENTION General Discussion In general, as shown in FIG. 14, the system 100 of the present invention includes several interrelated components that can be used to help one to manage one's physiological and or psychological state. These components will be described in greater detail later but, in general, include one or more of the following: 1. Portable Biosensor Device ( 102 ) A portable biometric device that is worn or carried by a user and which senses and records physiological parameters on a continuous basis. 2. Master Set of Images ( 104 )/Therapeutic Image Classification System ( 106 ) A set of images presented to a user to determine the user's physiological and cognitive image preferences. The images are classified according to a therapeutic image classification system. 3. Biometric Analyzer ( 108 ) A biometric analyzer which extracts the physiological activation state of user from one or more measured physiological parameters. 4. Cognitive Analyzer ( 110 ) A cognitive analyzer which extracts cognitive state from cognitive responses to images. 5. Personal Image Profiler ( 112 ) A personal profiler which combines the physiological and cognitive measures obtained from the biometric analyzer and cognitive analyzer to generate an individual's personal image profile for a given state response. 6. Personal Image Classifier ( 114 ) A personal image classifier which, based on an image bank having images which have been classified using a therapeutic image classification system, and on the personal image profile, selects activating and deactivating images to create a personal image set. 7. Visualization System ( 116 ) A visualization system which presents the personal image set to a person with the goal to help manage, modify or maintain current physiological and psychological state. The components of system 100 can take different forms, depending on the application. For example, the portable biosensor device 102 measures one or more physiological parameters of an individual. The measurements can be recorded in the device and appropriate resident software used to analyze the state of the individual. Alternatively, the measured physiological parameters can be transmitted over a wireless channel to a server where they are recorded and analyzed. A warning signal can then be transmitted back to the portable device to warn the user of the need to manage one's state. Components 104 - 112 can reside as software in a computer that is located with the individual, at a health care professional's office, or the like. The images selected by component 114 can reside in local or remote database(s) that can be communicated with over standard communication links (public telephone, cell phone, internet/world wide web, intranet, etc.). The visualization system 116 , includes a display which can form part of a computer, a television, a handheld device, such as a PDA, game, or entertainment device, a slide projector, a cell phone. The visualization system can include devices such as a CD player, a DVD player, a VCR, etc. The system can include devices for other sensory feedback, such as, auditory, olfactory, tactile (heat, vibratory), etc. The applications of the present system are set out in greater detail below. The interrelated use of these components is set forth in FIGS. 1 and 2. As shown in FIG. 1, the process 10 is started (bubble 12 ). It is determined (diamond 14 ) if this is a first time use. If the answer is no, the process of FIG. 2 is carried out (A). If the answer is yes, the process continues (box 16 ) where an appropriate visualization system presents a master set of images to the user. If the Portable Biosensor Device has been used, it is docked to the visualization device to give a record of physiological parameters of the user measured over a period of time (box 18 ). The biometric analyzer(box 20 ) and cognitive analyzer measures (box 22 ) physiological and cognitive states from the user during presentation of the master set of images. The personal profiler (box 24 ) generates the user's personal image profile based on the combined physiological and cognitive measures. Based on the personal image profile and a therapeutic image classification system (box 26 ) for images in a therapeutic image data bank (databases) (box 28 ), activating and deactivating images are selected from the image data base(s) to create a personal image set (box 30 ). The user then decides (diamond 32 ) if he or she wants to have a session. If no, the session ends (bubble 34 ). If yes, the process continues to A in FIG. 2 . Once a personal image set has been established, the user can start a session (A). The Biometric Analyzer (box 40 ) and Cognitive Analyzer (box 42 ) can be used to determine a user's desired direction/preference for a session (e.g., relaxation, optimal performance, excitation (box 44 ). Based on the inputs, the Personal Profiler (box 46 ) decides if the current Personal Image set will work or if an updated, Personal Image profile is needed. The Personal Profiler can also receive inputs from a Portable Biosensor Device (box 48 ) and from a user's physiological, cognitive and image use history from a secured data base (box 50 ). If the current image set is determined to be OK (diamond 52 ), the visualization device presents images to the user according to one's preferences. The duration and/or sequence of presentation, the type of transformation of the images are performed based on users physiology. (box 54 ) Input from a “Coach” (box 56 ) may also be provided. The “Coach” monitors physiological responses of the user and provides feedback in form of visual feedback, verbal reinforcement, verbal suggestions and new techniques. The user then decides to continue or not (diamond 58 ). If yes, the process is returned to A. If no, the process is ended (bubble 60 ). If the current image set is determined to be not OK (diamond 52 ), the process is operated in a learning mode (box 62 ) where other images from an image bank are shown on a trial and error basis. The user may wish to create an updated profile (diamond 64 ). If “yes”, the process continues to “B” in FIG. 1 . If “no”, the process is ended (bubble 60 ). Following are more detailed descriptions of each of the components described above. Portable Biosensor Device In medical compliance (taking medicine regularly, exercising regularly etc), it may be beneficial for a user to have a system that tracks, reminds, and rewards the user. On the same token, for an excellent individualized biofeedback based wellness management program, The Portable Biosensor Device tracks and reminds the user to perform wellness management as needed. The Portable Biosensor Device is a portable device having one or more sensors that record physiological parameters of an individual wearing the device. Different individuals react differently to different sensors under different situations. Through individual sensor response profile (as explained in personal profiler section) we will be able to produce a personalized device. The device contains multiple sensors to measure temperature, heart rate variability (HRV) (measured either from ECG, photoplethysmographic methods or continuous blood pressure), SCR (skin conductance response), EEG, EMG, eye saccades etc. The device will accommodate different sensor sets based on the embodiment. For example as shown in FIG. 5, a wrist type device 70 with sensors 72 and computer 74 can record temperature, HRV through continuous blood pressure monitoring, and SCR. A head band type of device 80 with sensors, 82 connected to computer 84 (on waist band-not shown) shown in FIG. 3 can measure EEG and EMG. As shown in FIG. 4, an earphone type of device 90 with sensors 92 connected to computer 94 (on waistband not shown) could measure temperature, heart rate variability through photoplethysmographic methods, and SCR. The portable biometric device is microprocessor based and records the user's physiology throughout the day, especially between sessions. Using digital signal processing on the sensor data, it will analyze (or analyze using the Profiler) and make predictions on the individual's state. Predictions will be made either using phasic physiological responses such as change in heart rate or SCR, or using sophisticated techniques such as Independent Component Analysis or pattern recognition. For example, increased heart rate and SCR could indicate activation or excitement, however, more sophisticated analysis could differentiate between excitement to startle and excitement in defense. According to Cacioppo et al (1996), though both the startle response and the defense response are associated with increased heart rate and SCR, they exhibit different patterns of activation. In the case of the startle response, the heart rate acceleration peaks and returns to near normal levels within two seconds, whereas in the case of the defense response, the heart acceleration does not begin to rise for several seconds and peaks much later. Moreover, if the user chooses to know, the feedback to the individual user can be provided through either vibration (tactile or kinesthetic), auditory, or visual means. The data recorded in the device can either be stored on the device or transmitted to an individual server via wireless communication channel. Biometric Analyzer The Biometric Analyzer plots, on a two/multi dimensional plot, physiological reactivity of each individual for different situations such as Baseline Different type of stressors (active coping task such as mental arithmetic, passive task such as situation narration) Calmed state Energized state It should be noted that 1. The reactivity to specific images can also be plotted on this plot, and mapping is performed to cluster images in various groups. 2. Various sensor measures, such as EEG, EMG, HRU, eye saccades, hand temperatures, etc., can be simultaneously used. 3. Clustering of images into various groups can be done using techniques such as Euclidean distance, ratio of distances etc. 4. Plotting can be done using different techniques such as principal component analysis, or independent component analysis, wavelet, neural networks, time series, and other signal processing techniques. One such technique (CLMOD) using principal component analysis, mapping images between a baseline and arithmetic stressor, using eye saccades, heart rate and EMG measures, and using a ratio of distance of the image to the stress to the distance of the image to the baseline is explained in more detail below. In general, this technique determines which images are physiologically “activating” or “deactivating”. The technique can be implemented as follows. A subject is seated in a comfortable chair before a display monitor. Sensors are attached to the subject to record biological information, such as, finger temperature, muscle tension, and heart rate. The physical responses are recorded while the subject views images presented on the monitor and while doing mildly stressful activities. The data is collected several (e.g., 256) times a second, while at rest, while viewing the images, and while cognitively rating them, as well as while talking about oneself and during a mental arithmetic task and during rest periods after each stress test. A subset of the physiological measures from these time periods is selected for use. The data is prepared using Fourier analysis for some physiological measures and histograms for other physiological measures. The data from the baseline, stress and rest time periods are broken into multiple, non-overlapping 15 second segments, and then a histogram or a spectrum computed from a Fourier analysis is used for each time segment. The histograms and/or spectra for each time segment are then fed into a Principal Component Analysis (PCA). In a preferred embodiment of this method, either Canonical Discriminant Analysis or Neural Networks might replace PCA. The result of the PCA analysis is that, (1) a set of weights called “loadings” is created, and (2) a set of “scores” or summary values, for each time segment is created. The data from the image periods are prepared using Fourier analysis and histograms, and the loadings are applied to these image period Fourier spectra and histograms. The result is a set of “scores” for each image period. The image period scores are then compared to the scores for the baseline, stress and rest time segments. An image score that is “close” to the centroid of the baseline scores indicates an image that is “deactivating”. An image that is close to the centroid of the stress scores indicates an image that is “activating”. An image score that is not “close” to either the centroid of the baseline scores or the centroid of the stress scores indicates an image that is neutral. What is meant by “close” can be determined in several ways. One technique is to determine the Euclidian distance from each centroid and then create the ratio of the distance to baseline centroid divided by distance to stress centroid. The difference between the image score and the blank period score can also be used instead of the image score itself. Following is a more detailed description of the CLMOD Analysis. Description of Biometric Analysis 1. Take physiology for baseline, discard first 2 minutes and last 2 minutes and chop remainder into non-overlapping 15 second segments. Call the data in these segments B 1 through B 24 . (An example of heart rate and EMG data for two consecutive 15 second segments are shown in FIGS. 6 and 7 respectively) 2. Take physiology for Stress 1 , chop into non-overlapping 15 second segments. Call the data in these segments S 1 1 , through S 1 12 . 3. Take physiology for Stress 2 , chop into non-overlapping 15 second segments. Call the data in these segments S 2 1 through S 2 12 . 4. Take physiology for Rest 1 , chop into non-overlapping 15 second segments. Call the data in these segments R 1 1 through R 1 12 . 5. Take physiology for Rest 2 , chop into non-overlapping 15 second segments. Call the data in these segments R 2 1 through R 2 12 . 6. For each data segment B 1 -B 24 , S 1 1 -S 1 12 , S 2 1 -S 2 12 , R 1 1 -R 1 12 , R 2 1 -R 2 12 , perform the following calculations: (a) Take the heart rate data and compute the periodogram (Fast Fourier Transform). Interpolate this periodogram so that the height of the periodogram is available at pre-specified intervals. An example of two periodograms that corresponds to the data shown in FIG. 7 is shown in FIG. 8 . (b) Take the EMG data and compute the histogram, using pre-specified bin widths. Store the percent of data in each bin. An example of EMG histograms corresponding to the data shown in FIG. 6 is shown in FIG. 9 . 7. Combine the heart rate interpolated periodogram, EMG histogram percents and Eye saccade histogram percents into one data set, where the rows are the different data segments and the columns are the histogram bins and/or periodogram heights. The histograms need to be aligned (and padded with zeros if necessary) so that the data in each column represents the same bin. 8. Scale this data set as follows: Subtract from each data point the mean of the column it is in. Each column then has a mean of zero. Each of the columns related to the heart rate interpolated periodogram has a variance (not standard deviation) of 1/n H , where n H is the number of pre-specified frequencies to use in the heart rate FFT. Each of the columns related to the EMG histograms has a variance of 1/n EMG , where n EMG is the number of such columns. Each of the columns related to the Eye Saccades histograms has a variance of 1/n EYE , where n EYE is the number of such columns. This scaling ensures that heart rate, EMG and Eye saccades contribute equally to the next analysis. An example of the result of this step is shown in FIG. 10, where the scaling has been performed not just for the two 15 second intervals shown on the plots, but across the entire set of 15-second segments as explained above. 9. Perform Principal Component Analysis (PCA) on this data, retaining the first 5 dimensions. (The number 5 was chosen arbitrarily, and it can vary from subject to subject.) Store the PCA scores in five dimensions. 10. For each image period, perform the analyses described above in 6a, 6b, 6c, 7, and 8. In step 8, use the mean calculated in step 8, not a new mean calculated on the Image period data. Take care to align the columns of the histograms to match the way the columns are aligned for the baseline, stress and rest data. Call these data segments I 1 -I 82 . Apply the PCA vectors from step 9 to the I 1 -I 82 data segments to compute PCA scores in five dimensions. Append these scores with the PCA vectors computed in step 9. 11. Plot the PCA scores in scatterplots, with different symbols for the different groups. An example of such a scatterplot is shown in FIG. 11 . 12. Compute the distance in n d dimensions (where n d is some pre-specified number) of each image location in PCA space from the centroid (mean PCA score) of each of the baseline, stress and rest period data. The metric for activation and/or de-activation is any one or more of the following. A threshold or cutoff needs to be set to pick which images are activating or de-activating or neutral. a).Distance from Baseline (or calmed state) Centroid b).Distance from Stress 1 (or activated state) Centroid c).Parks Ratio, which is (distance from baseline centroid)/(distance from stress 1 centroid) Modified Biometric Analysis 10′. In addition to step 10 above, for each blank period perform steps 6a, 6b, 6c, 7, and 8. Call these segments BL 1 -BL 82 . 11′. In addition to step 11 above, apply the PCA vectors to data segments BL 1 -BL 82 . 11.5′ Subtract the PCA scores for each image segment from the PCA scores from each blank period. Call these data Δ 1 -Δ 82 . 12′. Plot the PCA scores for Δ 1 -Δ 82 instead of the PCA scores for the image periods I 1 -I 82 . Also, as in the previous step 12, plot the PCA scores for the baseline, stress and rest periods. The subtracted PCA scores are interpreted as showing the direction and amount of movement due to the change from blank to image period. Thus, we are really plotting the end of a vector whose other end is at the origin. An image that has vector length close to zero shows little physiological movement and can be interpreted as neutral. The following steps are used to determine activation and deactivation: (a) Determine the angle for each image Δ 1 -Δ 82 . This can be done in n d dimensions (where n d is some pre-specified number). (b) Determine the set of angles for the baseline period data segments. If an angle for Δ 1 -Δ 82 is contained in the range of angles for the baseline period and the length of the vector for each of Δ 1 -Δ 82 is above some threshold, then we say that this image is de-activating. Vectors that point in the baseline direction but are less than this threshold value are considered neutral. (A modification would be to add ±k to the range of angles to allow for some uncertainty is our ability to locate the baseline cluster; k might be 10 degrees, we need to experiment to find a good value for k.) (c) Determine the set of angles for the stress 1 period data segments. If an angle for Δ 1 -Δ 82 is contained in the range of angles for the stress 1 period and the length of the vector for each of Δ 1 -Δ 82 is above some threshold, then we say that this image is activating. Vectors that point in the stress 1 direction but are less than this threshold value are considered neutral. (A modification would be to add ±k to the range of angles to allow for some uncertainty is our ability to locate the baseline cluster; k might be 10 degrees, we need to experiment to find a good value for k.) (d) Vectors that do not point towards either Stress 1 or Baseline are considered “other”. These might be pointing towards other stress modes, or other calming modes, or they may be neutral. We cannot decide from this analysis. Therapeutic Image Classification Scheme This scheme is a set of a scene and image related features or attributes (or characteristics) that are relevant to potential therapeutic effect in a broad sense which includes emotional, sensational, cognitive, arousing, esthetical and any other possible impacts registered psychologically or psychophysiologically, that an image may produce while a person viewing the picture. By therapeutic effect, hence, we understand the ability of an image or series of images, video clips, or other visual material alone or in combinations with other modalties purposely presented to improve a person's process, (quality, productivity or effectiveness) performance, state or attitude under consideration which otherwise would become a limiting or negative factor in the person's activities. These aspects are related to the person self, his/her interaction with the outside world (information, specific tasks, etc.) and inter- personal interaction and conmmunication. The above features are related to an appearance, content, composition, semantics, intentionally sought impression, uncertainty in interpretation, emotional load and probability of association with a particular emotion, etc. and ideally should represent all dimensions that may influence a holistic impression an image (or other type of visual and other stimulations mentioned above) produces. The attributes can be rated in terms of importance and profoundness for each image. Therapeutic Imaging Classification Scheme Subject Matter Anything that appears to be a primary subject or part of the primary subject is categorized. Defined categories include: Landscapes Natural or imaginary scenery as seen in a broad view, consisting of one or more of the following elements which dominate a large percentage of and/or being central to the image. Mountain Water Sun Vegetation Sand Snow Urban People—Activity Static The subject either does not exhibit movement or intentionally poses. Active Captured at the moment of active motion. People—Expression No expression Happy faces A happy facial expression of a person that is the subject matter. Unhappy faces Unhappy facial expression of a person is a subject matter People Children People who appear to be 18 years old or younger. Family The primary subject includes a group of two or more people, regardless of age, exhibiting strong bonds of familiarity and/or intimacy. Animals Pets A domestic or tamed animal kept for pleasure or companionship (e.g., dogs, cats, horses, fish, birds, and hamsters). Pleasant A picture of a pet doesn't or is not intended to generate an unpleasant feeling or look. Unpleasant A picture of a pet does or is intended to generate an unpleasant feeling or look. Wild An undomesticated or untamed animal in its original natural state, or confined to a zoo or animal show (e.g., lions, elephants, seals, giraffes, zebras, and bears). Pleasant A picture of a wild animal doesn't or is not intended to generate an unpleasant feeling or look. Unpleasant A picture of a wild animal does or is intended to generate an unpleasant feeling or look. Abstract An image which achieves its effect by grouping shapes and colors in satisfying patterns rather than by the recognizable representation of physical reality. Other Other can be used when neither of the defined categories of the subject matter can be applied. Lighting Sun Predominantly distinct shadows are noted. This also includes indoor photos where the subject is directly illuminated by sun through a window. Shadows must be present. If the subject is shading itself, the primary type of light is SUN. Sunset/Morning/Evening This type of light is typified by long shadows. Hazy/cloudy/Overcast This type of light produces soft shadows (if any) and the light direction is often obscured, flat, and low contrast. Shade This light is relatively diminished or partial due to cover or shelter from the sun. This also includes Indoor pictures where the subject is illuminated by diffuse daylight from a window. Mix Sun and Shade This type of light includes spotty sunlight or a mixture of sun and shade. Flash A brief, intense burst of light from a flashbulb or an electronic flash unit, usually used where the lighting on the scene is inadequate for picture-taking. Color/Dominant Hue Determined when one or two colors are seeing to be the prominent and global descriptors for a particular picture. If three colors are seen than we define that the picture does not have a dominant hue. Red Yellow/Orange Green Blue Purple/Magenta Brown White/Grey No Dominant hue (if more than 2) Direction of Light Front Light shining on the side of the subject facing the camera. Hints: Sunlight conditions where the shadow falls behind the subject. Flash pictures from point and shoot cameras. Side Light striking the subject from the side relative to the position of the camera; produces shadows and highlights to create modeling on the subject. Hints: Sunlight conditions where long shadow falls on the side of the subject. Back Light coming from behind the subject, toward the camera lens, so that the subject stands out vividly against the background. Sometimes produces a silhouette effect. Hints: TV's, Sunsets, and “Lights are Subject” are backlit. In backlit scenes, the shadow may fall in front of the subject, and appears to come towards the photographer. Zenith Light coming from directly above the subject. Hints: High noon lighting. Deep shadows in the eye sockets and below the chin. Diffuse Lighting that is low or moderate in contrast, such as an overcast day. Hints: Diffuse produces no shadows or just barely visible shadows, such as found on a cloudy, hazy day. Some mixed sun and shade pictures are also diffuse when the direction of light can not be determined. Multidirectional This indicates lighting coming from different directions, such as some stage lighting conditions or in a home where a window is on one side of the subject and a lamp on the other. Multiple shadows should be present if the lighting is from different directions and a flash was used. Travel/Offset Direction of Gaze Motion/Travel A subjective feeling (introspection) of moving one's eyes primarily along a particular trajectory or in a certain direction while viewing a picture. Centered Right to left/Left to right Up to down/down to up Multidirectional Distance Low 0-9 feet Medium 9-20 High more than 20 Cognitive Analyzer Images from the master image set are presented to the subject to identify his or cognitive response profile in terms of which image attributes and images alter an individual emotional response and arousal level. The individual is asked to rank an image on one or more of three cognitive scales. Preferably, a measure of the cognitive preference computed from the scores along three cognitive scales is used, i.e., Valence, Arousal and Connectedness. Definitions of Scales Each scale is a two-ended scale with an anchor in the center marked 0 . These three scales are described below: Scale 1: Detached—Attached (Connectedness) −4 −3 −2 −1 0 1 2 3 4 Detached —————— Attached Detached is a feeling of not being able to personally connect or relate to the object or situation depicted in the image. Attached is a feeling of personnel connection to the object or situation depicted in the image. Scale 2: Unhappy—Happy (Valence) −4 −3 −2 −1 0 1 2 3 4 Unhappy —————— Happy Unhappy is a feeling of sadness or disconnect that occurs when you view the object or situation depicted in the image. Happy is a feeling of contentment or satisfaction that occurs within you when you view the object or situation depicted in the image. Scale 3: Calm—Excited (Arousal) −4 −3 −2 −1 0 1 2 3 4 Calm —————— Excited Calm is a feeling of tranquillity and silence that occurs within you when you view the object or situation depicted in the image. Excited is a physical state of being in which your feelings and emotions have become aroused that occurs when you view the object or situation being depicted in the image. The user is given enough time to provide their reaction to each of the scales. He/she is instructed to follow their first impression. To facilitate the emergence of feelings that could be associated with an image, the users are encouraged to imagine themselves being “in an image” or part of an image that they are viewing. However, the users are requested not to force themselves to feel an emotion. Certain images may be neutral and elicit no emotions. Reactions will be different for each individual. All three scales can be used individually to provide a measure of valence, arousal and connectedness. Each of them constitutes a valuable information source related to the person's reaction and can be independently used to assess them. The three scales can be combined to compute the measure of the cognitive preference. Current implementation of the cognitive preference computation takes into account the absolute value of the total response, the variance of the ratings along each scale within an individual to normalize the response and logical rules that intend to increase the internal validity of the measure. The method and procedure are as follows: Step 1 Every image, I, is subjectively rated along each of the axes Attached/Detached (C), Calm/Excited (A) and Happy/Unhappy (V) such that it has three values C (I), A(I), and V (I) associated with it. R(I i )=(C 2 (I i )+A(I) +V 2 (I i )) Step 2 Normalize scale values C(I i )=C(I i )*R(I i )/max i R(I) A(I i )=A(I i )*R(I i )/max i R(I) CI i )=V(I i )*R(I i )/max i R(I) Where i=1 . . . 82 Step 3 . Compute the standard deviation per scale: S  ( V ) = ∑ i       ( V  ( I i ) - mean  ( V  ( I i ) ) ) 2 n - 1 S  ( A ) = ∑ i       ( A  ( I i ) - mean  ( A  ( I i ) ) ) 2 n - 1 S  ( C ) = ∑ i       ( C  ( I i ) - mean  ( C  ( I i ) ) ) 2 n - 1 Step 4 . Normalize every scale value from each image using appropriate standard deviations C(I i )=C(I i )/S(C) A(I i )=A(I i )/S C) V(I i )=V(I i )/S(C) Step 5 . If C(I i )<=1, then C(I i ) is Neutral along the C scale If A(I i )<=1, then A(I i ) is Neutral along the A scale If V(I i )<=1, then V(I i ) is Neutral along the V scale Step 6 . If image is Neutral along the V scale and is neutral along any other one scale it is overall neutral. Step 7 . Paradoxical images If image I is not neutral and (V(I)>0)&(C(I)<0)& (A(I)>0 or (V(I)<0)&(C(I)>0)& (A(I)<0 then I is considered to be a paradoxical one. Step 8 . Cognitively preferred. If image I is not neutral and not paradoxical I is cognitive preferred <=> (V(I)>0) with the score equals V(I) Step 9 Cognitively not preferred If image I is not neutral and not paradoxical I is cognitively not preferred <=> (V(I)<0) with the score equals V(I) THE PERSONAL IMAGE PROFILER Each individual user has their own characteristics; preferences of images, music, coaching etc., in other words, each person has a unique personal profile. This profile is thought to allow us to be better able to select images or other stimuli for the user. To be able to select images requires sophisticated methods not only to record but to analyze and understand the trait and state data of a person. The personal profiler does exactly that. 1. It gathers data from the portable biometric device (on going physiological data), biometric analyzer (Physiological data for different situations and images), and the cognitive analyzer (data on demographics, psychographics, cognitive preferences for images). The preferred method is as follows: Step 1. Selecting Activating/Deactivating images: a) Use BIOMETRIC analyzer method (e.g. CLMOD) to identify clearly activating or deactivating images. If the image is close to the baseline cluster then the image will be considered deactivating, or if the image is closer to the stressor cluster, then the image will be considered deactivating. b) Only in situations, where we do not have enough images to fill the four categories 1 - 4 , we will use Calm/Exciting scale along with the BIOMETRIC analyzer method to pick activating/deactivating images. c) Ranking rule: The images will be ranked based on following criteria a. Ratio of distance of the image to stressor and baseline Step 2. Dividing the Activating/Deactivating images into C+ and C− categories: a) Use data from the scales in COGNITIVE ANALYZER to categorize images as preferred or not preferred. We do not use Calm/Excited scale. b) For PARADOXICAL images make decisions using rules specified in the COGNITIVE ANALYZER: c) Ranking rule: The Euclidean distance on Unhappy/Happy and Detached/Attached scales will be used to rank the images in the C+ and C− categories. The top ranking images will be used if the total number of images in each category is more than 10. Step 3. Augment Images by Reducing Threshold if Necessary a) If the number of images in any of the four categories (picked based on Biometric analyzer method, and cognitive scales) is less than 4 then we will try to Increase the number of images by lowering the threshold in BIOMETRIC model Increase the number of images by lowering the threshold in the cognitive model to 0.55 SD (currently the threshold is 0.67 SD) b) If the number of images in any category are more than 4 but less than 10, we will try to maximize the number of total images using upto 5 similar for each image. The minimum number of images in each session would be 15 and maximum will be 20. c) If the number of images from any category are more than 10, we will pick the top 10. The ranking will be based on ranking rules specified in steps 1 and 2. The total number of images will be 30 and we will pick upto 2 similar for each image. Step 4. Handle Images that Show Very High Physiology but Neutral Cognitive a) We reduce the threshold of the two cognitive scales to to 0.55 SD to see if that puts the image in consideration into C+or C−. b) If not, we assign the image into both the C+ and C− category Step 5. Handle images that show very high cognitive but neutral physiology a) We reduce the threshold in BIOMETRIC ANALYZER model to see if that puts the image in consideration into activating or deactivating. b) If not, we assign the image into both the activating and deactivating category 2. Based on this data, it creates an individualized profile. The profiler uses generic models and population data to make predictions and personalization of coaching, stimuli, and even the user interface of the image presentation device. 3. Using digital signal processing on the sensor data, it analyzes and makes predictions on the individual's state. Predictions will be made either using phasic physiological responses, such as change in heart rate or SCR, or using sophisticated techniques, such as individual component analysis or pattern recognition. For example, increased heart rate and SCR could indicate activation or excitement, however more sophisticated analysis could differentiate between startle and defense. According to Cacioppo et al (1996), although startle response and defense response are both associated with increased heart rate and increased SCR, they exhibit different patterns of activation. In the case of startle, the heart rate acceleration peaks and returns to near normal levels within two seconds, whereas in the case of defense response the heart acceleration does not begin to rise for several seconds and peaks much later. 4. All the data is recorded in the profiler for future reference and use. The Personal Profiler also keeps records of data collected from subsequent biofeedback sessions. 5. Using statistical methods, the profiler tries to understand what worked and what did not. PERSONAL IMAGE CLASSIFIER The Personal Profiler collects the data from the BIOMETRIC analyzer and COGNITIVE analyzer and classifies the images into 1) Cognitively preferred/Physiological activating 2) Cognitively preferred/Physiologically deactivating 3) Cognitively not preferred/Physiological activating 4) Cognitively not preferred/Physiological deactivating Images selected using cognitive analyzer and biometric analyzer are treated as a collection of images that describes an individual image profile. After classifying the master images into these four categories, the Personal Image Classifier, builds these image sets by picking images from the Therpaeutic Image Bank using similarity metrics method. Therpaeutic image bank uses the therapeutic image classification scheme to accurately mark each individual image with its inherent characteristics. The goal is to find images similar to each image in a profile to create sets of images that share similar characteristics with respect to individual's reactions. Therpeutic image bank may contain personal pictures as well as stock photographs. The ultimate goal is to be able to classify images automatically using this scheme. The procedure currently used is: 1. All the images in the image bank are tagged with a 0 (for a particular feature not existent in the image) or 1 (for a particular feature not existent in the image), as shown in tables below. The colums represent the features from the classification scheme. PEOPLE/ LANDSCAPE ACT EXPRESSION PEOPLE # ABS OTH Mt Wt Vg Sun Snd Snw Urb Sta Act Non Hap Unh. Chd Fam 1 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 2 1 1 . . . 1 1 N 1 ANIMALS Pleasant Unplesnt LIGHTING LIGHT DIRECTION # Pet Wld Pet Wld Sun Snst Haz Othr Ind Frnt Side Bac Znith Dfus 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 2 1 . . . 1 1 N 1 1 COLOR - DOMINANT HUE DISTANCE TRAVEL/OFFSET # Red Y/Or Grn Blu Prp Brn Gry Blk Non Low Medm Hig Ctr U/D L/R Mult 1 0 1 0 0 0 0 0 0 0 0 1 0 0 1 0 0 2 1 1 1 1 . . . 1 1 1 1 N 1 1 1 2. To build a particular image cluster (say calming images), copy the classification record of all calming images from the master set for the particular individual into a buffer. 3. Examine each image from this buffer and using similarity matrix techniques such as Minkowski method, find similar images from the image bank. A similarity metrics can be established as the sum of all agreements between image features established in the step 1 and weighted by the feature importance (for an individual). Thus the Minkowski metric with various exponents can be used to determine the similarity. We used the value of the exponent equal to 1. Weighting coefficients are determined experimentally using a screening or specifically designed testing procedure and are considered as the order of an individual's feature importance related to the therapeutic effect. 4. Copy the new formed cluster into a new database for the individual with other metadata such as user identification, data and time of clustering, physiological reactivity to each image, cognitive reactions to each image. This metadata will eventually be used in the personal profiler to evaluate the effectiveness of images in subsequent sessions. VIZUALIZATION SYSTEM This is the main component that the user works with images to relax, energize, or do biofeedback training. This could be implemented on a computer, TV with set top box, handheld device such as PDA's, CyberFrames, or gaming devices . The purpose of the Visualization System is to allow participants to maintain their mind-body wellness using proper personalized coaching based on trends in physiology and cognitive feeling. Uniqueness of Visualization System is: Personalized image selection and training that understands the users trends in activation or deactivation. Coaching that continues even after the session and allows one to do a retrospective analysis of physiology changes between sessions. Intelligent image understanding and personal preference data allows the coach to guide the user to certain parts of image or to a totally different image as needed. The overall mind-body wellness is achieved by presenting a series of stimuli (e.g. images) that are selected based on personal cognitive and physiological preferences in an order that is “natural” for the individual, along with personalized coaching and relevant feedback. The process includes the following steps: (1) To initiate a session, the user docks the buddy into a docking station (if the image presenter is implemented on a TV or a desktop computer) or into a docking port if it is a handheld device. (2) If this is the first session, the system needs some profiling data to understand what images are suitable for this individual. The profiling is done using a Master Image Presenter and Personal Profiler. The system records demographics and psychographics data for the user. (3) A master set of images (A Kodak set designed based specifically for different cultures) are presented to the user and their cognitive feelings and physiological reactivity are recorded for each image. (4) As described in the Personal Profiler (including biometric analyzer and cognitive analyzer), the cognitive preference is recorded using the three scales, whereas physiological reactivity is recorded for the most sensitive measures. The physiological sensitivity for each individual is recorded using different situations such as baseline, different stress activities, calming, and energizing activities. (5) As described in the Personal Image Classifier, the cognitive and physiological feelings are combined using certain rules and used to categorize the master set images into preferred calming, preferred activating, and neutral images. The Personal Image Classifier builds a unique set of images for the individual, based on similar images selected from the therapeutic image classification scheme and the therapeutic image data bank. Each image is coded with metadata, such as the features of the image, its rank on physiological reactivity for the subject, its rank on the cognitive scaling, etc. This metadata is used eventually to decide when and how long this particular image will be presented. At this stage either cognitive, physiology or both can be used for categorization. Different product embodiments can have different implementations. (6) In subsequent sessions, the Image Presentation Device uses the unique image set in presentation. (7) Establish the identification of the participant before allowing access to the system either through password authentication or physiology measures signatures. Understand from the user what they would like to do today and try to assess the correlation between how they feel cognitively and what their physiology is suggesting. (8) Provide general instructions on how to breathe as the user views different images. This coaching will be a combination of diaphragmatic breathing, autogenics, guided imagery, and meditation thoughts. The Visualization System incorporates appropriate coaching (male/female voice, autogenics/no autogenics, some mechanism of trust-building, diaphragmatic breathing etc), different types of feedback, personalized order of presentation, personalized schemes of fading, and appropriate timing. (9) Feedback can be either direct feedback through either digital readouts of physiology and/or various graphical means such as abstract bars, trend charts, slider graphs, colored bar graphs, etc., or indirect feedback through changes in the image parameters such as hue, saturation, sharpness. (10) The system will also provide continual reinforcement based on the trend and temporal changes in the user's physiology state. (11) Through out the session, the system tracks the physiology trends on the sensors that are most sensitive to the user. The intelligent coaching agent has certain generic rules built in. It also has a learning system that understands and records the user's sensitivities to different physiology measures as well as their responsiveness, and according modifies the instructions. The coaching agent bases its instruction both on the physiological changes as well as the feelings that are recorded through cognitive scales. (12) The user interacts with the coach through natural interactions such as speech, direct point and click, and physiology changes. The coaching agent has a “persona” that is customized for each individual. Different persona of the coach could be varied on the gender, ages, instruction styles, mannerisms, personality types that a particular user likes. Certain amount of anthropomorphism is also provided in the coaching agent to facilitate one-to-one connection between the coach and the user. (13) The coach also has intelligent image understanding and provides certain cues on contents of the images. These cues are stressed if the coach has prior knowledge about the user's preference. (14) Apart from the individually selected mix of images, the Visualization System also provides individual image categories (sunset, beaches, rain, landscapes, family, children etc). (15) It also provides both individualized and generic transforming images. Transforming images can include images that transform existing content such as an image showing sunset, or a flower blooming as well as adding new content e.g. a waterfall scene with a rainbow added to the scene if the user achieves a certain stage in the calming process. (16) Throughout the session the Personal Profiler records the efficiency of the images. The profiler keeps record of what worked and what did not. (This is thought at the current moment to be available in the advanced implementation). (17) The influence of the Visualization System on the user's behavior does not end at the end of the session. At the end of the session, the coaching system records how the user feels and will tell the user that they should carry the feelings and learning from this session to the real world. The user physiology will be monitored by the portable biosensor device between the sessions. The coach can then query, understand and advise the user based on the physiology data that is collected between sessions. The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. PARTS LIST 10 process 12 60 process steps 70 wrist type device 72 sensors 74 computer 80 head band type device 82 sensors 84 computer 90 earphone type device 92 sensors 94 computer 100 system 102 prtable biosensor device 104 master set of images 106 therapeutic image classification system 108 biometric analyzer 110 cognitive analyzer 112 personal image profiler 114 personal image classifier 116 visualization system

A method for classifying images according to features that are relevant to potential therapeutic effect, comprising: providing an image; and classifying said image according to one or more of the following classes, landscapes, people-activity, people-expression, people-type, animals, color (dominant hue(s)), direction of light, type of light, distance, travel/offset(direction of motion/travel).

[0001] This application claims the benefit of United States Provisional Patent Application No. 60/435,502, filed on Dec. 19, 2002, the disclosure of which is hereby incorporated by reference. [0002] The invention was made by an agency of the United States Government or under a contract with an agency of the United States Government. The name of the U.S. Government agency is DARPA and the Government contract number F29601-00K-0184. [0003] Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever. BACKGROUND OF THE INVENTION [0004] 1. Field of the Invention [0005] The present invention relates to the field of VLSI (Very Large Scale Integration) circuit design, and in particular to a method for VLSI synthesis based on data-driven decomposition (DDD). [0006] 2. Background Art [0007] Asynchronous VLSI is heralded for its robustness, low power, and fast average-case performance. Many chip designers, however, are deterred from taking advantage of these qualities by the lack of a straightforward design approach. [0008] In designing asynchronous VLSI systems, the formal synthesis of asynchronous VLSI systems begins with a sequential description of the circuit specification and results in a complex and highly concurrent network of transistors. This is accomplished through the application of a series of transformations that preserve the semantics of the program. [0009] One synthesis method begins by describing circuits using a high-level language, Communicating Hardware Processes (CHP). Successive semantics-preserving program transformations are then applied, each generating a lower-level description of the circuit. The final output is a transistor netlist. This method is correct by construction, and every chip designed using this approach (including a 2M-transistor asynchronous MIPS R3000 microprocessor) has been functional on first silicon. However, until recently, the transformations have all been applied by hand, with heavy dependence upon simulations at every level. Syntax-Directed Decomposition [0010] Within the series of transformations performed on the CHP, the most difficult transformation is the first step, process decomposition. This step is also one with a large effect on the speed and energy efficiency of the final system. In process decomposition, the original sequential CHP description of the circuit is broken up (decomposed) into a system of communicating modules (still expressed in CHP) that are then individually synthesized at lower levels. The inter-module communications mapped out during this step consume the bulk of energy in the finished asynchronous system, as data must be not only sent, but also validated and acknowledged. [0011] After decomposition, the synthesis steps that follow compile the concurrent system into successively lower-level descriptions, with the final system being expressed as a network of transistors. Therefore, keeping the decomposition target processes simple makes the rest of the synthesis steps feasible. [0012] Currently, designers rely greatly on experience and intuition to create an energy-efficient system. Existing formal methods of decomposition in the synthesis of asynchronous circuits are purely syntax-directed. As such, they decompose a process into a set of basic processes, each of which corresponds to a syntactic construct in the source language. Although CAD tools exist for process decomposition, they are mostly syntax-directed, or they begin with a lower-level specification than CHP. For example, the designers of the asynchronous MIPS R3000 saw that very fine-grained pipeline stages were required to achieve high throughput, and abandoned the syntax-directed approach because it could not generate modules that were small enough. [0013] What is desired is a new method of decomposition that can formalize the ad-hoc decomposition while maintaining results close to those obtained by hand in the current state of art. Such a method would decompose a high level program description of a circuit into a collection of small and highly concurrent modules that can be implemented directly into transistor networks, all without requiring the laborious, and often unsuccessful, trial-and-error iterations of the informal manual approach. SUMMARY OF THE INVENTION [0014] The present invention relates to the field of VLSI circuit design, and in particular to a method for VLSI synthesis based on data-driven decomposition (DDD). [0015] One embodiment of the present invention is a systematic and data-driven decomposition method to decompose a high level program description of a circuit into a collection of small and highly concurrent modules that can be implemented directly into transistor networks. The formalized method enables an automatic implementation of a decomposition process currently done by hand. Since the method stays at the level of the source program, it is entirely general and has applications beyond the scope of asynchronous design. [0016] Instead of being dictacted by the syntax of the input program, the decomposition method of the present invention examines data dependencies in the process' computation, and then attempts to eliminate unnecessary synchronization in the system. Depending on the flow of data in the original process, concurrency may be added into the system through decomposition. To avoid dealing with mutual exclusion problems, no shared variables or communication channels are permitted. The decomposed processes transfer data by explicitly communicating with each other. Data Driven Decomposition (DDD) Process [0017] [0017]FIG. 1A shows one embodiment of the present invention, comprising the following: a conversion to convert the input program in CHP into an intermediate Dynamic Single Assignment (DSA) form (2), a projection process to decompose the intermediate DSA into smaller concurrent processes (4), and a clustering process that optimally groups small concurrent processes to make up the final decomposition (6). [0018] DSA conversion involves transforming the input program into a form wherein no variable is assigned a value more than once during execution. Multiple assignments to the variable may appear in the process code (for example, in different branches of a selection), but only one will actually be executed during each iteration of the process's outer loop. The identity of this assignment is not known until runtime. [0019] The overall decomposition approach specifies that each target process consist of all of the assignments that occur in the source process to a particular variable. Converting the source process into DSA form can reduce the number of assignments to a variable and hence simplify the target processes of a decomposition. Since simple target processes make the post-decomposition steps of synthesis easier, one thing that the DSA conversion does is to take variables with multiple assignments in the source process and split them to create new DSA variables. [0020] These DSA variables are then projected onto their own target processes in the projection step (step 4 of FIG. 1A). The decomposition method of the present invention directs the contents of the projection sets by specifying that each set should contain the variables and channels required to implement the assignments to a particular DSA variable. This is a different approach then the one done in the past, where designers have relied on experience and intuition in choosing which variables belong in what projection set. [0021] The correctness of projection has been proven under the assumption of slack elasticity. In the current state of the art, projection has been used to verify the equivalence between source processes and systems that have been decomposed informally by hand. However, up till now, there has been no effective and general application of projection in creating process decompositions. The present invention thus transforms projection from a verification tool to a decomposition tool. [0022] Because of the constrcut of rewriting the program in the DSA form, the projection of present invention can find the decomposed solution ahead of time. Graphical decomposition follows from the DSA form—if each new process computes a value for a single variable, then the data dependency graph that the variables create provides an overall view of the final decomposed system. The edges in the graph indicate the new intermediate channels required for decomposition and, by their presence, also imply the existence of new copies of variables. With such guidelines, a shorthand form of projection can be directly applied to the program without rewriting any lines of code. In short, the variable and edges of each point node comprise a separate projection set from the main program. [0023] Thus, instead of the prior art methods of relying on experience and intuition in choosing which variables belong in what projection set, the decomposition method of the present invention directs the contents of the projection sets by specifying that each set should contain the variables and channels required to implement the assignments to a particular DSA variable. [0024] In the present invention, the projection set of a variable x contains: (1) the variables and input channels on whose value the assignment to x depends; (2) the output channels on which x is sent; (3) the intermediate channels created by decomposition for communication between the new target processes. [0025] DSA conversion and projection are illustrated in FIG. 1B. By controlling the contents of each projection set, each DSA variable is isolated into its own target process. [0026] As a simple example, consider the following process: P≡*[A?a, B?b, C?c; x:=f ( a,b ), Y!g ( b,c )] [0027] (The notation used to specify the behaviour of circuits illustrated in the present invention is CHP, a variant of CSP designed for communicating hardware processes.) [0028] After decomposition, the process becomes: P≡CPb∥Px∥PY CPb≡*[B?b; B x !b, By!b] Px≡*[A?a, B x ?b; x:=f ( a, b )] PY≡*[B y ?b, C?c; Y!g ( b, c )] [0029] P is decomposed into an equivalent system that contains target processes for the assignments to variable x and to output channel Y. The resultant system is illustrated in FIG. 1C [0030] The processes in a decomposed system produced by the process of DSA conversion and projection are slated for clustering. Recomposing DDD modules into larger modules further improves energy and performance. DDD modules can be clustered together with different goals in mind: reducing energy consumption, reducing forward latency, or reducing the time and energy-efficiency metric Et 2 . An example of clustering optimization is illustrated in FIG. 5, where graph 60 shows a system before clustering and graph 62 shows the equivalent system after clustering. [0031] Clustering is implemented in two stages. In the first stage, DDD modules along the critical path of a system are repeatedly clustered in series until they are too large to be implemented as single PCHB stages. The second stage requires a global optimization algorithm (e.g. quadratic programming, simulated annealing, and genetic algorithms) to both cluster DDD modules in parallel and add slack-matching buffers to improve performance. [0032] Another embodiment of the present invention is a DDD decomposition and projection algorithm implemented in computer program codes in a computer storage media. Another embodiment of the present invention is a clustering tool implemented in computer program codes in a computer storage media. The clustering tool receives as its input a concurrent system of DDD modules, as well as physical limits and desired cycle time of PCHB buffer stages. The output of the clustering tool is a coarser-grained concurrent system of modules that can still each be implemented as a single asynchronous pipeline stage. BRIEF DESCRIPTION OF THE DRAWINGS [0033] These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where: [0034] [0034]FIG. 1A outlines the data-driven decomposition (DDD) process according to an embodiment of the present invention; [0035] [0035]FIG. 1B illustrates the process of DSA conversion and the projection process according to an embodiment of the present invention; [0036] [0036]FIG. 1C shows an example result of projection; [0037] [0037]FIG. 2 outlines the DSA conversion process according to an embodiment of the present invention; [0038] [0038]FIG. 3 outlines the projection process according to an embodiment of the present invention; [0039] [0039]FIG. 4 shows additiona steps that can be performed in DSA conversion; [0040] [0040]FIG. 5 illustrates an example where possible communications savings are achieved when guards are encoded using the method of the present invention; [0041] [0041]FIG. 6 outlines the clustering process according to an embodiment of the present invention; [0042] [0042]FIG. 7 shows an example where two DDD modules that appear in sequence can be clustered according to an embodiment of the present invention; [0043] [0043]FIG. 8 shows an example where two DDD modules that share the same inputs are clustered; [0044] [0044]FIG. 9 shows a column view of a slack-matched concurrent system; and [0045] [0045]FIG. 10 depicts a general computer embodiment. DETAILED DESCRIPTION OF THE INVENTION [0046] The present invention relates to the field of VLSI circuit design, and in particular to a method for VLSI synthesis based on data-driven decomposition (DDD). Embodiments of the present invention comprise of methods that aid the design of VLSI circuit by formalizing and automating decomposition based on data dependencies. [0047] In the present invention, the basic units of decomposition are assignments to a variable (whether through a communication with another process or an actual assignment statement). The goal is to give every variable in the source process its own target process that implements all assignments to that variable. These target processes mostly conform to a basic template. To keep the target processes simple enough for future synthesis, the decomposition method must control the number of assignments to each variable in the source process. [0048] One decomposition method embodiment is comprised of three stages. First, the source process is converted into Dynamic Single Assignment (DSA) form. Then, the process is projected onto disjoint sets of its variables and communication channels. This projection results in a system of new, small, communicating target processes. Finally, clustering is performed to optimally group smaller processes together to form the final output. [0049] In the following sections, the three stages are described in order, along with the implementation of an algorithm embodiment of DDD in a computer storage media. 1 DSA Conversion Requirements [0050] In converting to DSA form, certain fine-tuning must be performed on the input program. For an CHP input program P as input, the following restrictions are placed on P: [0051] It is non-terminating. Instead of executing its statements only once, the program is enclosed within a main, unconditional loop. [0052] All statements are contained within main loop. Initial actions that occur before the main loop must be removed and handled through processes separate from the main program. [0053] A variable is assigned in the same loop iteration that it is used. State variables must be removed and handled through processes separate from the main program. [0054] There are no arrays. Array structures must be extracted into their own process, leaving only independent variables in the main program. [0055] All variables have only one assignment statement during the loop. Variables that are assigned a value more than once during a main loop iteration must be split into multiple single-assignment variables. [0056] Thus, several streamlining steps must be performed to conform the input programs to these four requirements. FIG. 2 outlines the action steps within DSA conversion 2 . These action steps need not be performed in any particular order. In steps 10 and 12 , initial actions and state variables, if found, are extracted from the main program and given their own processes. Also, arrays are extracted into their own processes in step 14 . The process finds variables that have multiple assignments, and perform actions to ensure that such variables are only assigned once (step 16 ). Straightline programs and selection statements (the main part of the input program) are handled in step 18 . As such, each action handles a particular component one may encounter in an input program. Each action that is performed in the conversion of the input program into DSA is outlined below. [0057] 1.1 Initial Actions [0058] Initial actions are channel outputs or variable assignments that occur before the main loop of the program begins. In the program below, both the output on X and the assignment to y are initial actions. X!x_init, y↓; *[ A?a;   [ a y → Y?y    a y → X!f(a, y); Y?y  ] ] [0059] To separate the initial actions from the main loop, buffer processes that are initialised with a token are created. The buffer for X is now placed between the output of the main loop and the environment. Meanwhile, the buffer for y reads in the current value of the variable and then writes it back to the next iteration of the main loop. In the rewritten program below, all statements in the main process are contained in the main loop.  Y curr !false; *[ Y next ?y; Y curr !y ] || X!x_init; *[ X out ?x; X!x ] || *[ A?a, Y curr ?y;    [ a y → Y?y     a y → X out !f(a, y); Y?y    ]; Y next !y     ] [0060] 1.1.1 State Variables [0061] State variables are variables that are not always explicitly given a value during a main loop iteration before being used in that iteration. When the program is encapsulated in a single process, the value of the variable is implicitly remembered between iterations. However, when the program is decomposed, the value must be explicitly remembered and communicated between processes. To prepare for decomposition, then, the program must be rewritten to remove the state variables. [0062] In the following program, if a is false then b is not given a new value for the iteration. Thus b is a state variable. *[ A?a; [ a → B?b a → skip ]; X!f(a, b) ] [0063] To remove a state variable from a program, a buffer process that will receive the value at the end of one iteration and send that value to the beginning of the next iteration is created. (This new process is similar to that created when initial assignments are extracted from the mainline program. In this case however, the initial value sent by the buffer is not used by the main process.) The rewritten program is as follows:  B curr !junk; *[ B next ?b; B curr !b ] || *[ A?a, B curr ?b;    [ a → B?b     a → skip    ]; X!f(a, b), B next !b    ] [0064] If it is only on rare loop iterations that a state variable is not given a value, then sending the value through the buffer after every iteration can seem expensive. In such cases, adding complexity to change the state variable process from a simple buffer to a process with conditional inputs and outputs may be worthwhile. If a variable is assigned a value often enough, the reduction in the number of communications may balance out the more complicated new process in the eyes of the designer. [0065] Finally, if a variable is only conditionally assigned a value during an iteration and is also conditionally used, it may not be a state variable. For example, in the following program, b is not a state variable. *[ A?a; [ a → B?b; X!f(a, b) a → skip ] ] [0066] Although their data must usually be remembered between loop iterations, arrays are not state variables. They will be handled separately in the next section. [0067] 1.2 Arrays [0068] Another action that may need to be performed in the conversion to DSA is the isolation of arrays in the input program (step 14 of FIG. 2). The decomposition algorithm of the present invention does not allow for shared memory between individual processes in the system. All of the variables accessed by a process must be either explicitly input or computed within the process. Hence, arrays in the program must be given special consideration, because the index of the element to be used in an array is usually only determined during computation. The decomposition algorithm therefore cannot know ahead of time which array value a process needs to access, and communication channels cannot be established. [0069] One embodiment of the present invention handles arrays by isolating them into their own CHP processes. When given a specific index, this process can read values from and assign values to the array. In this case, only array indices and single elements of data need to be communicated across a channel, and never entire arrays. [0070] Implementing this method involves rewriting the original CHP process by explicitly assigning certain expressions to their own variables. The following expressions are to be given their own variables: [0071] Array Indices. An array index is to be sent on a channel from the main process to an array process. If the index is not already a single variable, the computation of its value should be encapsulated in a separate process during decomposition. Explicitly assigning the index expression to a new variable allows the decomposition algorithm to extract this computation automatically. As an example, the code y:=A[x 1 ], Z?BE[x 2 +x 3 ] [0072]  is rewritten to be y:=A [x 1 ], bx:=x 2 +x 3 ; Z?B [bx] [0073] Array Values in Larger Expressions. If an assignment or output expression is comprised solely of an array value in the form A[x], no new variable is required. [0074] However, if the array value forms only one part in a larger expression, this value must be given its own variable. Thus, the main process has an explicit placeholder to receive the value when it is transmitted from the array process. To illustrate, the code y:=A [x 1 ], Z!B [x 2 ] [0075]  remains the same, but the code y:=A [x 1 ]+2 , Z!f ( B[x 2 ], C[x 3 ]) [0076]  is rewritten as follows: ax:=A[x 1 ], bx:=B[x 2 ], cx:=C[x 3 ]; y:=ax +2 , Z!f ( bx, cx ) [0077] Array Values Assigned to Other Array Values. If a single array value is assigned to another array value, an intermediate variable should be used to simplify the eventual isolation of arrays into their own processes. For example, A[x 1 ]:=B[x 2 ] [0078]  becomes data:= B[x 2 ]; A[x 1 ]:=data [0079] Reconsider the program P array which has three arrays A, B, and C. Explicitly assign new variables for the scenarios listed above. The updated code now becomes   *[ I?i, S?s, T?t;     [ i.op1 → idx := s + t; a := A[idx], b := B[s];         X!f(a, b), C[t] := const      i.op2 → idx := t + 2; c := C[idx]; A[s] := c      i.op3 → c1 := C[s], c2 := C[t]; idx := c1 + c2;         b := B[idx]; A[s] := b      i.op4 → b := B[t]; idx := s + B[t];         c := C[t]; A[idx] := c      i.op5 → B[s] := const    ] ] [0080] Once this is done, it is time to abstract the array and isolate it in its own process. Every array process requires a channel on which it inputs the index of the desired access, channels on which it can output the results of an array read and input the values for an array write. The variables that appear in the conditions of these reads and writes must also be sent to the new array process. In short, the array structure is extracted, and the variables that determine the conditions of array access are copied into the new process. [0081] First consider array A. Depending on the value of i, some element in A is either assigned a value (write), or is assigned to another variable (read). Only one of these actions will take place during the loop iteration. The process representing A therefore requires a channel to receive the condition variable i, a channel to receive the array index of the desired action, a channel rdA on which an array value can be output, and a channel wrA on which an array value can be input. The process for A appears below. arrayA ≡ *[ aI?i;       [ i.op1 → idxA?idx; rdA!A[idx]        i.op2 i.op3 i.op4 → idxA?idx; wrA?A[idx]        i.op5 → skip      ] ] [0082] Similarly, array B only ever performs a single read action or a single write action during a loop iteration. The CHP code representing this array now reads: arrayB ≡ *[ bI?i;       [ i.op1 i.op3 i.op4 → idxB?idx; rdB!B[idx]        i.op5 → idxB?idx; wrB?B[idx]        i.op2 → skip      ] ] [0083] In some cases, two read actions are performed on array C during the same loop iteration. In addition to the standard condition and write channels then, the process representing C requires two outgoing data channels, and two incoming index channels. arrayC ≡ *[ c1?i;       [ i.op2 i.op4 → idxC1?idx1; rdC1!C[idx1]        i.op3 → idxC1?idx1, idxC2?idx2;          rdC1!C[idx1], rdC2!C[idx2]        i.op1 → idxC1?idx1; wrC?C[idx1]        i.op5 → skip      ] ] [0084] Now the three array processes have been extracted. While new communication actions have been added to the remaining program, only single index or data values are ever transmitted on these channels, and never entire arrays. Because all of the actual array operations are handled in a single process for each array, no shared variables are required. Here is the updated main program: main ≡ *[ I?i, S?s, T?t; aI!i, bI!i, cI!i;  [ i.op1 → idx := s + t; idxA!idx, idxB!s, idxC!t; rdA?a, rdB?b; X!f(a, b), wrC?const; i.op2 → idx := t + 2; idxA!s, idxC!idx; rdC?c; wrA!c i.op3 → idxC1!s, idxC2!t; rdC1?c1, rdC2?c2; idx := c1 + c2; idxB!idx, idxA!s; rdB?b; wrA!a i.op4 → idxB!t; rdB?b; idx := s + b; idxC!t, idxA!idx; rdC?c; wrA!c i.op5 → idxB!s; wrB!const ] ] [0085] 1.3 Variables Splitting [0086] When converting a process into DSA form, variables with multiple assignments need to be split into new variables that can be assigned at most one value during execution (step 16 of FIG. 2). Splitting a variable involves associating an index number with each appearance of the variable in the original process. [0087] More specifically, the assignment of index number occurs: (1) when a variable is the input or assignment statement at which it is defined, (2) when it is in the output statement of an output channel. In the case where the variable is within a selection structure, only the actual assignment statement itself and the guard conditions that point to it would receive an index assignment. Any guard conditions that do not point to an assignment statement for the variable in question are lumped together into an else condition that points to a skip command. [0088] Thus, if a process has N assignments to variable x, the converted process can assign these values to separate new variables x 1 , x 2 , . . . , x N , in that order. Of course, all references to the variable x in between assignments must be changed as well. [0089] Regular assignments have the general form x:=f (a, b, . . . ), where x, a, and b are variables. In the present decomposition method, every regular assignment (or set of assignments to a variable that occur in different branches of a selection) is projected out into its own target process. Communication statements are also considered to be assignments: A?a assigns the value on the input channel A to variable a, while X!f (a, b, . . . ) assigns a value of function f to the output channel X. [0090] In programs where variables receive have multiple assignments, creating new variables simplifies decomposition. If every instance of a variable between is split into a distinct new variable, the program itself remains functionally unchanged. Consider the following CHP: *[ A?a, B?b, C?c; X!a;   [ b → a := f(a, b); Y!a    b → Y!c, Z!a  ] ] [0091] The variable a appear twice: the first as an unconditional input, while the second as a conditional assignment. Thus, two new variables a 1 and a 2 are created. When the code is rewritten as follows, the functionality of the program remains the same: *[ A?a 1 , B?b, C?c; X!a 1 ;   [ b → a 2 := f(a 1 , b); Y!a 2    b → Y!c, Z!a 1  ] ] [0092] As long as they appear in different guarded commands of a single selection structure, a variable can be counted once and no rewrite is necessary. When a statement that gives a value to a variable is located in a guarded command, it does not affect the code in any other guarded commands. For example, although c is given a value in two different statements in the code below, since they both occur in different guards of the same selection structure, they add up to only one value point. Therefore no extra variables need to be created. *[ A?a, B?b; [ b → C?c b → c := a ]; X!c ] [0093] 1.4 Straightline Programs [0094] In step 18 of FIG. 2, the main input program is converted into DSA form. A commonly found program structure is straightline assignments. When multiple assignments to a variable x appear in a series of statements with no branches of control, x can easily be split into new variables with a single assignment each. (Since there is only a single branch of control, every assignment that appears in an unconditional series is guaranteed to be executed.) Consider a general straightline series of the form A 1 ; x:=f 1 ( . . . ), B 1 ; A 2 ; x:=f 2 ( . . . ), B 2 ; [0095] where A i and B i are CHP fragments that do not include any assignments to variable x. For all i, 1≦i≦n, one can rewrite each program part A i ; x:=e i , B i as ( A i ) x→x i-1 ; x i :=( e i ) x→x i-1 , ( B i ) x→x i-1 [0096] (The notation (S) a→b indicates that all instances of a in CHP code S are replaced by b.) The rewritten CHP is functionally equivalent to the original series, but is now in DSA form since each new variable x i is assigned a value only once. If x has been assigned a value in the CHP prior to this series, then it is assumed that this initial value is stored in the variable x 0 . The following example demonstrates how a series P may be rewritten in DSA form: P≡A?a, B?b; x:=a, y:=b; X!x; C?x; X!x P DSA ≡A?a, B?b; x 1 :=a, y:=b; X!x 1 ; C?x 2 ; X!x 2 . [0097] 1.5 Selection Statements [0098] Furthermore in step 18 of FIG. 2, as the main input program is converted into DSA form, the present invention handles another commonly found program structure, namely, selection statements. A selection is in DSA form when no branch of control contains more than one assignment to the same variable. Consider a selection containing K assignments to x, with a maximum of N, N<K, such assignments in any guarded command. Instead of creating a new variable for each of the K assignments, the method of the present invention creates N new variables x i , 1≦i≦N. Then, the ith assignment to x can be replaced with an assignment to x i in each guarded command. This results in each new variable x i having at most one assignment in each branch of the selection and therefore being a DSA variable. Within any branch of the selection, assignments to variables x i still appear in increasing order of i. [0099] The selection is not in DSA form yet though because one issue still remains, that is, the last variable x N (which will replace x in any CHP that immediately follows the selection statement) may not always be assigned a value. If the kth guarded command contains n k assignments to x, the version of x that was last assigned a value in the guarded command is x n k . Therefore the following statement is appended to every guarded command for which n k <N: x N :=x n k . These extra assignments merge the most recent of all branch assignments to x into one variable, x N , that can be used by all CHP immediately after the selection. [0100] As an example, consider the process C below with variables x and y, expressions e A , e B , e C , and guard expressions g A , g B , g C . C ≡ [ g A → x := e A ; A?x    g B → x := e B    g c → y := e C   ]; S [0101] Variable x has multiple assignments, with a maximum of two assignments in any selection branch. Therefore, it is split into the new variables x 1 and x 2 following the guidelines given previously. The rewritten process is now C split ≡ [ g A → x 1 := e A ; A?x 2      g B → x 1 := e B      g C → y := e C     ]; S [0102] To convert the C Split into DSA form, it now only remains to, in the cases where X 2 is not already assigned a value, assign to it either the value of x 1 or an initial value that is called x 0 . The selection C Split , so rewritten, becomes C DSA . C DSA ≡ { x 0 = init_expr }     [ g A → x 1 := e A ; A?x 2      g B → x 1 := e B ; x 2 := x 1      g C → y := e C , x 2 := x 0     ]; (S) x→x 2 [0103] Now x 2 can be used in the code after C DSA , and the selection is in DSA form. 2 Projection [0104] After the input source process has been converted to DSA form, the task of breaking it into smaller target processes can begin. Ideally, these new processes are each small enough to be easily compiled into HSE. Often, the hardest aspect of decomposition is deciding which parts of a large process should be separated from each other. [0105] While the basic units of decomposition are variable assignments, the basic tool is the method of projection. Projection is a decomposition technique in which a CHP process is syntactically projected onto disjoint sets of its communication channels and variables. The resulting “images” are the new processes that together form a system which is functionally equivalent to the source process. For example, the process *[ A?a, B?b; X!a, Y!b] [0106] projected onto the sets { A?, a, X !} and { B?, b, Y!} [0107] results in the new system *[ A?a; X!a]∥*[B?b; Y!b]. [0108] Note that the new system is only equivalent to the original process if that process is slack elastic, a requirement that will be further detailed. A few other requirements are enumerated below: [0109] No Multiple Use of Channels. Programs that use an input or output channel more than once in a main loop iteration form a special case for graphical decomposition, and are not dealt with here. [0110] No Nested Loops. Programs with this construct form a special case for graphical decomposition, and are not dealt with yet. [0111] Open System. A closed system usually contains state variables. When these are removed from the program, input and output statements result, turning the system into an open one. In the case where a closed system has no state variables, the decomposition method can still be applied, with the starting points being variable assignments instead of output statements. [0112] The correctness of projection has been proven under the assumption of slack elasticity. However, currently projection is only used for the verification of manually produced process decompositions, rather than for their creation. This is because usually the original process must be rewritten before projection can be applied. Splitting a program in two adds intermediate channels to the system. These new channels, along with the copies of variables that are to be sent on them, must be explicitly written into the CHP code before projection. In one sense then, the decomposed solution must be known ahead of time for projection to be applied. [0113] The projection of present invention finds such a solution in advance. Graphical decomposition follows from the DSA form—if each new process computes a value for a single variable, then the data dependency graph that the variables create provides an overall view of the final decomposed system. The edges in the graph indicate the new intermediate channels required for decomposition and, by their presence, also imply the existence of new copies of variables. With such guidelines, a shorthand form of projection can be directly applied to the program without rewriting any lines of code. In short, the variable and edges of each point node comprise a separate projection set from the main program. [0114] Thus, instead of the prior art methods of relying on experience and intuition in choosing which variables belong in what projection set, the decomposition method of the present invention directs the contents of the projection sets by specifying that each set should contain the variables and channels required to implement the assignments to a particular DSA variable. [0115] As such, the projection set of a variable x contains: (1) the variables and input channels on whose value the assignment to x depends; (2) the output channels on which x is sent; (3) the intermediate channels created by decomposition for communication between the new target processes. [0116] 2.1 Slack Elasticity [0117] Projection can only be applied to decompose a process if that process is slack elastic. The slack of a communication channel specifies the maximum number of outstanding messages allowed (the amount of buffering) on that channel. A process is slack elastic if its correctness is preserved when the slack on its channels is increased. Concurrency can be therefore be added to slack elastic processes by pipelining the computation. For example, the process *[L?a; b:=f (a); R!g(b)] remains correct when decomposed into the system *[L?a; X!f (a)]∥*[X?b; R!g(b)]. To other processes, the slack of L or of R has increased by one, but the computation from the original process remains the same. The process is therefore slack elastic. Processes that are deterministic (in which the guards of selection statements are mutually exclusive) are necessarily slack elastic. [0118] 2.2 Projection Sets [0119] [0119]FIG. 3 shows how projection proceeds and how projection sets are constructed. First, a dependence set is created for each variable assignment in the input program in DSA form (Step 34 ). If a target process is implementing an assignment to the variable x, then any variable that appears in the function assigned to x belongs in the dependence set. For example, if the assignment is x:=a b c, then variables a, b, and c all belong in the dependence set for x. If the assignment is the communication A?x, then the input channel A? is a member of the dependence set of x. If the assignment is conditional, then the variables that appear in the guard expressions for the assignment also appear in the dependence set. [0120] Thus, given the selection statement [ a → x := d b → X?x (a b) c → y↓ (a b) c → y↑ ] , [0121] the dependence sets for x and y are as follows: DS ( x )≡{ a, b, d, X?}, DS ( y )≡{ a, b, c}. [0122] When the variable dependence sets have been formed for each assignment in the source process, the number of copies of each variable will be required in the decomposed system is known. In the previous example, two copies are required of both a and b. It follows that new channels will be needed to transfer the values of these copies of a and b. These channels are referred to as intermediate channels and are added so that the target processes can communicate with each other in the decomposed system (step 36 of FIG. 3). These intermediate channels are named according to a simple naming scheme, which is a concatenation the names of the two variables in question. Thus, if a belongs in the dependence set of x, then intermediate channel A x is responsible for sending the value of a to the target process of x. A x ! is therefore added to the projection set of a, while A x ? is added to the projection set for x (step 38 ). Copies of a and b must also be created to send to the target processes for x and y. Using a similar naming convention as for intermediate channels, these new copy variables are named a x , a y , b x , and b y , The projection sets for x and y are now: PS(x)≡{a x , A x ?, b x , B x ?, d, X?}, PS(y)≡{a y , A Y ?, b y , B y ?, c y }. [0123] 2.3 Copy Variables and Channels [0124] In step 36 , the copy variables and channels are incorporated within the CHP code that is being projected. First, statements that assign the proper values to these copy variables are added. Then, the assignment statements are converted into an equivalent pair of communications using the corresponding intermediate channel. For example, the copy assignment a x :=a is rewritten as (A x !a∥A x ?a x ) (where A x ! is already in the projection set for a, and A x ? is in the projection set for x). The version of a that appears in the assignment to x is then replaced by a x . [0125] This replacement is straightforward if a appears on the RHS of the assignment to x. However, if the assignment to x is conditional and a appears in its guard expression, then the replacement can be more complicated. In general, if an assignment appears in a selection of the form [ g(a) → x := b, y := c else → ... ] [0126] and copy variables a x and a y have been created, then the selection is rewritten as [ g(a x ) g(a y ) → x := b, y := c else → ... ] [0127] where the value of a has previously been assigned to a x and a y . [0128] 2.4 Breaking Up into Processes [0129] In step 38 , projection sets are created to match the added copy variables and intermediate channels. With the sets in place, a final step 40 is performed in projection to break the CHP code into separate processes. The entire mechanisms of projection are illustrated further by the following example process P: *[A?a; b := a; [ b → x↑ b → B!b]] [0130] Through the construction the dependecne sets (Step 34 ), it is known that variable b appears in the dependence sets of both x and B!. Therefore copy variables b x and b B , and intermediate channels B x and B B are created (Step 36 ). The CHP is changed to incorporate them, but remains functionally equivalent. First, the copy variables are introduced: *[ A?a; b := a; b x := b, b B := b;   b x b B → x↑ b x b B → B!b B ]  ] [0131] Then, the copy assignments are rewritten as pairs of communication statements: *[ A?a; b := a;   (B x !b||B x ?b x ), (B B !b||B B ?b B );   [b x b B → x↑ b x b B → B!b B ]  ] [0132] The assignments to b, x, B! are projected out onto their own processes at step 40 . The designate projection sets are PS(b)≡{A?, a, b, B x !, B B !}, PS(X)≡{b x , B x ?, x}, and PS(B!) ≡ {b B ,B B ?,B!}. The new decomposed system is Pb ≡ P {A?,a,b,B x !,B B !} ≡ *[ A?a; b := a; B x !b, B B !b ] Px ≡ P {b x ,B x ?,x} ≡ *[ B x ?b x ; [b x → x↑ b x → skip]] PB ≡ P {b B ,B B !,B!} ≡ *[B B ?b B ;[b B → skip b B → B!b B ]] [0133] 2.5 Adding Copy Processes and Eliminating Simple Buffers [0134] In order to keep target processes—as well as any future recomposition or clustering of these processes—as simple as possible, the number of output channels in each target process is limited to one. Thus, if the value of a variable x is required by multiple other target processes, the process for x is given a single output and is then appended a copy process. For example, the process P b from the previous section becomes *[A?a; B cp !( a)]∥*[B cp ?b; B x !b, B B !b]. On an opposite note, target processes which are simple buffers are never created. This is accomplished by not creating individual projection sets for communication statements (assignments) that are not enclosed in a selection statement. Consider the code *[A?a; x:=f(a); X!x]. There are three assignments in this process and if each were decomposed into its own process, the system *[A?a; A,!a]∥*[A x ?a; x:=f (a); X x !x]∥*[X x ?x; X! x ] would result. Under slack elasticity, the new system is identical to the original one: in this case the decomposition does not simplify the system. Therefore target processes are not created for communication assignments unless they appear within a selection statement, in which case their target processes would be more complex than a simple buffer. [0135] 2.6 Projection Algorithm [0136] An algorithm embodiment for process decomposition by way of projection is presented below. The algorithm is based on the implementation of the steps from FIG. 3. More specifically, it works from a definition of a value point of a variable, which collects all of the assignments to a signle variable (after DSA conversion) in the CHP code. Input communications are considered assignments to the input variable; the value point of an output channel consists only of output communications. Only variables and input channels can be input arguments for value points. [0137] The decomposition algorithm repeatedly chooses an output channel from the main program and, by projection, creates a process to compute the channel's value point. In the end, every value point in the original program has its own node process. Splitting off a process creates new outputs from the main program. Since once a value point node is created by a function, it calls itself again to create a node for the value point of one of its input arguments, this is a recursive algorithm. The recursion is complete when the main program consists of a single value point. The listing of the function is presented below: [0138] Listing 1 DRAW_NODE( var, target ) {  Create a new node, “var_node”, for this variable.  Draw an edge from this node to the target.  Get argument list for value point of this variable.  For each argument in the list {   If a node for the argument already exists, then    Draw an edge from the argument node to this node   Else, if the argument is an input channel, then    Draw an edge from the input channel to this node   Else    /*** Recursive Call ***/    DRAW_NODE( arg, var_node ) }  } [0139] In practise, applying formal projection repeatedly to CHP programs can be complicated and time-consuming. Every time a new process is created, the main CHP program must also be rewritten. If the algorithm is recursive with no global view of the program, it is difficult knowing when to include the original main program variable in a projection set, and when to create a new variable copy. To overcome this obstacle, the decomposition algorithm is broken into two stages. [0140] The first stage decomposes the program into a graph. Each node in the graph represents a value point. Specifically, each node represents the CHP process that computes one of the program's value points. Meanwhile, each edge represents a communication channel between node processes. A graph edge is directed: its source node represents the process that sends the variable out; its target node is the process that reads the variable in. [0141] The graph is drawn one node at a time, beginning with the value points of the original program's output channels, and continuing backwards to the input channels. When a node with input and output edges is created, it is the equivalent of outlining the communication channels of a new process and indicating which value point that process will compute. Conceptually, this is exactly the recursive projection method described in in the previous section. The only difference is the representation of the state of decomposition. Instead of explicitly writing the new CHP code for each state, the graph stores all of the information necessary to write the complete decomposition at the end of recursion, when every value point has been given a node. [0142] Writing the CHP for the node processes is the second stage of this decomposition, and it does not begin until the graph is complete. By this time, all of the internal communications in the decomposed system are established, and this global information is available in the readily accessible graph structure. Since the number of new channels and copies of a variable required given by the graph, the exact CHP can in fact be easily written for each node. The projection of copy processes from nodes with multiple output edges is the only rewriting of CHP required. The complete algorithm for the graphical decomposition of CHP programs is presented below: [0143] Listing 2 DECOMPOSITION ALGORITHM =  Create value points for every  variable and output channel in the program.  For every output channel   /*** Recursively create the graph ***/   DRAW_NODE( output channel, outside world )  For every node in the graph {   By projection, write the CHP process for the node.   N = Number of output edges for the node   If N > 1 then    Project out a copy process from the node. }  } [0144] The recursive function that forms the basis of this graphical method is given in Listing 1. The main algorithm given in the Listing 2 above creates a list of all value points and calls the recursive function once for each output channel in the program. When the recursion ends, a CHP process is written for each node. Nodes with multiple outputs are then split into a functional node and a copy node. Counterbalancing this, simple internal buffer nodes that arise from the algorithm can be eliminated, merging their input and output channels into one. 3 Energy Efficiency [0145] In VLSI design, reducing the number of communications in a system can greatly reduce the energy consumption. Of course, the specification of the original sequential program cannot be changed, and so the communications on external channels must remain the same. However, communications on internal channels introduced by process decomposition can be made conditional. This may decrease energy consumption in three ways: by reducing the wire load that is switched per cycle; by making entire modules conditional; by decreasing the actual number of channels in the system. [0146] The first way is obvious. In the second way, if all of the input and output communications of a module only occur under a certain condition, then the module can stop computing the condition and simply perform the main computation when its data inputs all arrive. For example, the program *[G?g; [g→X?x; Y!(x+1) g→skip] can be simply rewritten as *[X?x; Y!(x+1)], since x will only be sent when a computation is required any ways. Finally, the above transformation is also an example of the third way, as the channel G? has been eliminated from the decomposed system, along with its validity-check circuitry. [0147] 3.1 Creating Conditional Communications [0148] One embodiment of the present invention can set up sequential programs so that DDD can create conditional communications without introducing overhead. This is shown as step 42 of FIG. 4, where additional steps in DSA conversion are outlined. Consider: COND ≡ *[ G?g, A?x; Y!x;       [ g = 0 → B?b;x := f 1 (x,b); C?c;x := f 2 (x,c)        g = 1 → B?b; W!b        g = 2 → skip       ]; Z!x      ] [0149] First, when rewriting the program in DSA form, if a variable x is split within a selection statement into multiple DSA variables x i , then only the last of these variables actually needs to have a defined value at the end of the selection. Intermediate DSA variables can be undefined in guarded commands where they are not required. [0150] The DSA version of COND is therefore COND DSA ≡ *[ G?g, A?x 0 ; Y!x 0 ;        [g = 0 → B?b;x 1 := f 1 (x 0 ,b); C?c;x 2 := f 2 (x 1 ,c)         g = 1 → B?b; W!b, x 2 := x 0         g = 2 → x 2 := x 0        ]; Z!x 2       ] [0151] Variable x 2 is used outside of the selection statement and therefore must always be assigned a value. Intermediate DSA variable x 1 is only required in the first branch, however, and so is undefined in the other two branches. Now after applying projection in the normal fashion, the process implementing variable x 1 is Px1 ≡ *[ Gx1?g, X0x1?x 0 ;     [g =0 → Bx1?b; X1x2!f 1 (x 0 ,b) else → skip] ] [0152] Communications have been eliminated on intermediate channel X 1 x 2 when g≠0 with no overhead cost—even if X 1 x 2 were to remain unconditional, guard variable g would be required in both processes Px 1 and Px 2 . [0153] The next task is to ensure that defined values of variables are sent only when they are actually used in the receiving module's computation. To illustrate, note that in COND DSA both x 1 and W! depend upon b. However, x 1 is only assigned a value when g=0 and W!b is only executed when g=1. Therefore, place the projection assignments for intermediate channels Bx 1 and BW as follows: *[ G?g, A?x 0 ; Y!x 0 ;  [ g = 0 → B?b; (Bx1!b||Bx1?b x1 );      x 1 := f 1 (x 0 ,b x1 ); C?c; x 2 := f 2 (x 1 ,c)   g = 1 → B?b;(BW!b||BW?b w ); W!b w ,x 2 := x 0   g = 2 → x 2 := x 0  ]; Z!x 2  ] [0154] After projection, the process implementing assignments to variable b is Pb ≡ *[ Gb?g;     [ g = 0 → B?b; Bx1!b      g = 1 → B?b; BW!b      g = 2 → skip    ] ] [0155] 3.2 Encoding Guards [0156] As shown in step 42 of FIG. 4, another energy efficiency technique encodes guard conditions (branch conditions of selection statements) in fewer variables. The purpose of the transformation is to reduce the number and size of physical channels required in the decomposed system, given that every variable assigned a value within a selection statement depends upon the variables in guard conditions. For example, consider the following process. ENCex ≡ *[ G 0 ?g 0 , G 1 ?g 1 , G 2 ?g 2 , G 3 ?g 3 ; A?a, B?b, C?c;       [ f(g 0 ,g 1 ,g 2 ,g 3 ) → X!(a b), Y!(b c), z := a c        f(g 0 ,g 1 ,g 2 ,g 3 ) → z := b c       ]; Z!(a z)      ] [0157] If the guard conditions were encoded as follows: *[ G 0 ?g 0 , G 1 ?g 1 , G 2 ?g 2 , G 3 ?g 3 ; A?a, B?b, C?c;   h := f(g 0 ,g 1 ,g 2 ,g 3 );   [ h → X!(a b), Y!(b c), z := a c    h → z := b c   ]; Z!(a z)  ] [0158] the number of channels would depend on the size of the variables g i , the number of variables assigned a value in the selection (three), and the number of guarded commands in the selection statement (two). [0159] To begin, encode guards by assigning a communications cost to every variable in the sequential code. A variable that can hold K different values can be communicated on a 1ofK internal channel. (A 1ofK code comprises K data wires encoded in a one-hot style, and a single acknowledge wire.) For practical purposes, break large channels up into a group of channels of manageable size (e.g., 1-byte variables are not communicated on a 1of256 channel but rather upon four 1of4 channels). [0160] Choose some base channel-size 1ofB. Normally, B=4 but any reasonable value (say, B≦8) can be chosen for this purpose. If a variable x can assume K different values, then define V(x)=K. The internal channel required to communicate x can be implemented as ┌log B K┐ different 1ofB channels. This variable is therefore assigned a communications cost of C(x)=┌log B (V(X))┐. [0161] In summary, scanning through the sequential program then, for every selection statement: let G be the set of all guard variables in the selection; let N be the number of conditions in the selection; let A be the number of variables assigned a value within the selection. Let h be the variable that encodes the guard conditions. Now, compute E (the communications cost when guard conditions are encoded in h), and U (the cost when they are left unencoded). Then: C ( G )=Σ ∀g i ∈G C ( g i ) V ( h )= N E=C ( G )+ C ( h )* A U=C ( G )* A [0162] If E<U then encode the guard conditions of the selection in question. If not, leave the selection unencoded. The systems in FIG. 5 demonstrate the possible communications savings when guards using g i are encoded in h using the technique described here. [0163] Returning to the example, N=2 and A=3. Let V(g i )=4 for ∀g i ∈G. Then C(G)=4, C(h)=1, U=12, and E=7. In this case, encoding the guard conditions reduces the communications cost of the selection by almost half. In contrast, when V(a)=V(b)=4, the process *[A?a, B?b; [a b→x↑ else→x↓]] is an example of a selection for which it is better not to encode the guard conditions (U=2, E=3). 4 Clustering [0164] The small processes produced by the process of DSA conversion and projection are often good candidates for clustering. Recomposing DDD modules into larger modules further improves energy and performance of the overall system. DDD modules can be clustered together with different goals in mind: reducing energy consumption, reducing forward latency, or reducing the time- and energy-efficiency metric Et 2 . [0165] Clustering is implemented in two stages, as shown in FIG. 6. In the first stage, 52 , DDD modules along the critical path of a system are repeatedly clustered in series until they are too large to be implemented as single pre-charge half buffer (PCHB) stages. The second stage ( 54 ) requires a global optimization algorithm (e.g. quadratic programming, simulated annealing, and genetic algorithms) to both cluster DDD modules in parallel and add slack-matching buffers to improve performance. [0166] 4.1 Optimal Clustering Amount [0167] The modules produced by DDD are often smaller than necessary, creating concurrent systems with extra communications overhead. To reduce overhead, cluster modules are clustered together into larger CHP processes that still fit into a single PCHB asynchronous pipeline stage. Of course, an entire microprocessor can theoretically be implemented in a single pipeline stage by creating one large state machine. But limits both physical (e.g., the number of transistors in series) and self-imposed (e.g., cycle time) enforce a maximum size for pipeline stages. [0168] It can be determined from the CHP alone whether a clustered module exceeds the maximum limits using the template for PCHB circuits. To check whether there will be too many transistors in series in the pulldown network, one can scrutinize modules with complicated boolean functions. To check if the cluster exceeds the specified cycle time, one can examine modules with many wide communication channels. (Such modules can result in circuits with deep validity-check and completion trees.) [0169] 4.2 Clustering DDD Modules in Sequence [0170] If two DDD modules appear in sequence, as shown in FIG. 7, clustering them together may decrease the forward latency of the concurrent system. Their combined computation must first be check to ensure that it is simple enough that it fits into a single stage (i.e., count the transistors in series). Clustering two modules in sequence also reduces overall energy consumption by eliminating the channels (and validity checks) in between them. [0171] The asynchronous systems achieve peak performance when all of the inputs to a module arrive at the same time. This is the motivating principle of “slack-matching,” and it dictates that all paths from any primary input (external input channel in the sequential code) to a given module traverse the same number of pipeline stages. Slack-matching therefore helps determine the optimal number of pipeline stages along a path. Previous research shows that the Et 2 efficiency of a system is highest when there is an equal amount of power distributed to each pipeline stage. Combining this requirement with the results of slack-matching, it is noted a path that optimally has N pipeline stages is more efficient when all N stages perform some computation than when only two stages perform computation and the other N−2 are simple buffers there simply to add slack. [0172] Therefore the present invention clusters modules together in sequence only if they appear upon the longest path of the decomposed system (i.e., if clustering reduces the forward latency of the system as a whole). There is no point in clustering modules in sequence along shorter paths, since buffers will be added during slack-matching to improve performance anyways. When the forward latency of the system has been decreased, a new iteration is started and the method of the present invention attempts to cluster modules along the new longest path. Only when no new clusters will fit in a single pipeline stage does the method slack-match the system. [0173] Slack-matching is similar to the retiming problem in synchronous circuits, but in the asynchronous design style of the present invention, every module combines computation logic and latching instead of keeping them as separate units. Also, slack-elasticity allows for the adding of buffers (the equivalent of retiming registers) on any channel without worrying about adding an equal number to each input of a combinational logic block to preserve system correctness. Finally, since slack-matching is performed for Et 2 efficiency and time is not the only criterion, care must be exercised so as to not over-slack-match systems. [0174] 4.3 Clustering DDD Modules in Parallel [0175] Clustering modules that operate in parallel reduces energy consumption only when the modules share inputs (when both their computations depend on the same variable). When such modules are merged, their separate input communication channels are collapsed into one. This reduces the number of wires switched per cycle and eliminates the redundant input validity trees that used to grace each module. The two modules Pb and Pc in FIG. 8 illustrate such a scenario. [0176] Slack-matching also plays a role here. When the two modules are combined in parallel, it it desired that all inputs to the new module to arrive at the same time. Therefore the system can be thought of as a table with columns, where all modules in the same column are the same number of pipeline stages away from the primary inputs. For optimal performance, one embodiment of the present invention clusters modules that share inputs when they appear in the same column. [0177] On shorter paths that use simple buffers to match the lengths of longer paths, the columns of these buffers are swapped with computation modules so that more computation modules can be clustered together. This is illustrated in FIG. 9, where external channels A?, B? and C? are primary inputs while X! is a primary output. Modules P 6 and P 7 are in the same column and share inputs from CP 4 : as such, they can be clustered. Modules P 2 and P 3 both share inputs from CP 1 but are in different columns. [0178] If P 3 were swapped with the buffer before it, then it could be clustered with P 2 . But if the output channel of P 3 is much larger than its input channel, the swapping and clustering can increase the overall energy consumption in the system. [0179] It can be seen that the combination of clustering DDD modules and slack-matching for performance is a global optimization problem. [0180] 4.4 Clustering Tool [0181] One embodiment of the present invention is a clustering tool that receives as its input a concurrent system of DDD modules, as well as physical limits and desired cycle time of PCHB buffer stages. The tool first loops through clustering DDD modules in sequence until the forward latency can be reduced no further. If energy efficiency is the main goal, a cost function is input such that, when fed to an iterative search algorithm, clusters modules in parallel and finds a system that consumes minimal energy while matching the desired cycle time. The output of the clustering tool is a coarser-grained concurrent system of modules that can still each be implemented as a single asynchronous pipeline stage. 5 Embodiment of Computer Execution Environment (Hardware) [0182] One or more embodiments of the present invention that perform data-driven decomposition are implemented in computer software running on a plurality of general purpose computing devices as shown in FIG. 10. [0183] A keyboard 1010 and mouse 1011 are coupled to a system bus 1018 . The keyboard and mouse are for introducing user input to the computer system and communicating that user input to central processing unit (CPU) 1013 . Other suitable input devices may be used in addition to, or in place of, the mouse 1011 and keyboard 1010 . I/O (input/output) unit 1019 coupled to bi-directional system bus 1018 represents such I/O elements as a printer, A/V (audio/video) I/O, etc. [0184] Computer 1001 may include a communication interface 1020 coupled to bus 1018 . Communication interface 1020 provides a two-way data communication coupling via a network link 1021 to a local network 1022 . For example, if communication interface 1020 is an integrated services digital network (ISDN) card or a modem, communication interface 1020 provides a data communication connection to the corresponding type of telephone line, which comprises part of network link 1021 . If communication interface 1020 is a local area network (LAN) card, communication interface 1020 provides a data communication connection via network link 1021 to a compatible LAN. Wireless links are also possible. [0185] In any such implementation, communication interface 1020 sends and receives electrical, electromagnetic or optical signals which carry digital data streams representing various types of information. [0186] Network link 1021 typically provides data communication through one or more networks to other data devices. For example, network link 1021 may provide a connection through local network 1022 to local server computer 1023 or to data equipment operated by ISP 1024 . ISP 1024 in turn provides data communication services through the world wide packet data communication network now commonly referred to as the “Internet” 1025 . Local network 1022 and Internet 1025 both use electrical, electromagnetic or optical signals which carry digital data streams. The signals through the various networks and the signals on network link 1021 and through communication interface 1020 , which carry the digital data to and from computer 1000 , are exemplary forms of carrier waves transporting the information. [0187] Processor 1013 may reside wholly on client computer 1001 or wholly on server 1026 or processor 1013 may have its computational power distributed between computer 1001 and server 1026 . Server 1026 symbolically is represented in FIG. 10 as one unit, but server 1026 can also be distributed between multiple “tiers”. In one embodiment, server 1026 comprises a middle and back tier where application logic executes in the middle tier and persistent data is obtained in the back tier. In the case where processor 1013 resides wholly on server 1026 , the results of the computations performed by processor 1013 are transmitted to computer 1001 via Internet 1025 , Internet Service Provider (ISP) 1024 , local network 1022 and communication interface 1020 . In this way, computer 1001 is able to display the results of the computation to a user in the form of output. [0188] Computer 1001 includes a video memory 1014 , main memory 1015 and mass storage 1012 , all coupled to bi-directional system bus 1018 along with keyboard 1010 , mouse 1011 and processor 1013 . As with processor 1013 , in various computing environments, main memory 1015 and mass storage 1012 , can reside wholly on server 1026 or computer 1001 , or they may be distributed between the two. Examples of systems where processor 1013 , main memory 1015 , and mass storage 1012 are distributed between computer 1001 and server 1026 include the thin-client computing architecture, personal digital assistants, Internet ready cellular phones and other Internet computing devices. [0189] The mass storage 1012 may include both fixed and removable media, such as magnetic, optical or magnetic optical storage systems or any other available mass storage technology. Bus 1018 may contain, for example, thirty-two address lines for addressing video memory 1014 or main memory 1015 . The system bus 1018 also includes, for example, a 32-bit data bus for transferring data between and among the components, such as processor 1013 , main memory 1015 , video memory 1014 and mass storage 1012 . Alternatively, multiplex data/address lines may be used instead of separate data and address lines. [0190] In one embodiment of the invention, the processor 1013 can be any suitable microprocessor or microcomputer. Main memory 1015 is comprised of dynamic random access memory (DRAM) or other equivalent memory types. Video memory 1014 is a dual-ported video random access memory. One port of the video memory 1014 is coupled to video amplifier 1016 . The video amplifier 1016 is used to drive the cathode ray tube (CRT) raster monitor 1017 . Video amplifier 1016 is well known in the art and may be implemented by any suitable apparatus. This circuitry converts pixel data stored in video memory 1014 to a raster signal suitable for use by monitor 1017 . Monitor 1017 is a type of monitor suitable for displaying graphic images. [0191] Computer 1001 can send messages and receive data, including program code, through the network(s), network link 1021 , and communication interface 1020 . In the Internet example, remote server computer 1026 might transmit a requested code for an application program through Internet 1025 , ISP 1024 , local network 1022 and communication interface 1020 . The received code may be executed by processor 1013 as it is received, and/or stored in mass storage 1012 , or other non-volatile storage for later execution. In this manner, computer 1000 may obtain application code in the form of a carrier wave. Alternatively, remote server computer 1026 may execute applications using processor 1013 , and utilize mass storage 1012 , and/or video memory 1015 . The results of the execution at server 1026 are then transmitted through Internet 1025 , ISP 1024 , local network 1022 and communication interface 1020 . In this example, computer 1001 performs only input and output functions. [0192] Application code may be embodied in any form of computer program product. A computer program product comprises a medium configured to store or transport computer readable code, or in which computer readable code may be embedded. Some examples of computer program products are CD-ROM disks, ROM cards, floppy disks, magnetic tapes, computer hard drives, servers on a network, and carrier waves. [0193] The computer systems described above are for purposes of example only. An embodiment of the invention may be implemented in any type of computer system or programming or processing environment. [0194] Thus, a method for the synthesis of VLSI systems based on data-driven decomposition is described in conjunction with one or more specific embodiments. The invention is defined by the following claims and their full scope of equivalents.

The present invention is a systematic and data-driven-decomposition (DDD) method and apparatus for use in VLSI synthesis. The invention decomposes a high level program circuit description into a collection of small and highly concurrent modules that can be implemented directly into transistor networks. This enables an automatic implementation of a decomposition process currently done by hand. Unlike prior art syntax-based decompositions, the method of the present invention examines data dependencies in the process' computation, and then attempts to eliminate unnecessary synchronization in the system. In one embodiment, the method comprises: a conversion to convert the input program into an intermediate Dynamic Single Assignment (DSA) form, a projection process to decompose the intermediate DSA into smaller concurrent processes, and a clustering process that optimally groups small concurrent processes to make up the final decomposition. Another embodiment is a decomposition, projection, and clustering tool implemented in computer program codes.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation-In-Part application of, and claims the benefit of, the now expired provisional patent application entitled “Smoking Cessation Treatment With Appetite Suppression”, filed May 21, 2006, bearing U.S. Ser. No. 60/767,546 and naming Harlan Clayton Bieley, the named inventor herein, as sole inventor, the contents of which are specifically incorporated by reference herein in its entirety; and the currently pending non-provisional patent application entitled “Smoking Cessation Treatment With Appetite Suppression”, filed Oct. 30, 2006, bearing U.S. Ser. No. 11/554,364 and naming Harlan Clayton Bieley, the named inventor herein, as sole inventor, the contents of which is specifically incorporated by reference herein in its entirety; and the currently pending provisional patent application entitled “Replacement of Vitamin, Mineral, and Neurotransmitter Losses From Tobacco Smoking”, filed Jul. 23, 2007, bearing U.S. Ser. No. 60/951,328 and naming Harlan Clayton Bieley, the named inventor herein, as sole inventor, the contents of which is specifically incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to treatments for tobacco smokers. In particular, it relates to a method and treatment for placement of essential vitamins, minerals, and nutrients which the body loses as a consequence of tobacco smoking. In particular, it supplements vitamins, minerals, amino acids, co-factors, and neurotransmitters which are depleted from the body due to tobacco smoking. In addition, it reduces cravings for nicotine and food cravings which typically result from nicotine withdrawal. [0004] 2. Background [0005] The health problems associated with tobacco smoking have caused numerous individuals to attempt to end their use of tobacco products. However, as is well-known, tobacco products can be highly addictive due to the addictive quality of nicotine which is present in tobacco products. Many individuals attempt to quit smoking by simply stopping their use of tobacco products. Unfortunately, due to the strong addictive nature of nicotine, the abrupt cessation of tobacco usage (i.e., quitting “cold turkey”) fails in most cases. Quite often, individuals require more than willpower alone to free themselves from nicotine addiction. It would be desirable to have a method of aiding an individual to cease smoking without having to rely on substantial levels of willpower. [0006] In addition to the difficulty related to cessation of smoking, attempts to stop smoking often result in the creation of secondary problems related to smoking. In particular, a fairly common side effect that individuals experience when attempting to quit smoking is a substantial increase in appetite. The increase in appetite results in undesirable increases in body weight. In turn, the extra body weight can result in a variety of unwanted health problems, as well as an undesirable change in the individual's appearance. Further, the undesirable increase in body weight can have a detrimental effect on an individual's willpower when attempting to quit smoking, because the additional weight can be very frustrating to an individual. In fact, it may even contribute to an individual's decision to abandon their attempt to quit smoking. It would be desirable to have a method of increasing an individual's chances of success by avoiding unwanted weight gain during the difficult process of overcoming addiction to nicotine. [0007] To assist individuals attempting to quit smoking and free themselves of addiction to nicotine, a variety of methods have been tried. One such method has been the use of nicotine supplements to reduce nicotine craving by the individual. Nicotine supplements can take several forms. For example, a nicotine chewing gum has been developed which permits individuals to satisfy the body's craving for nicotine without damaging their lungs by inhaling tobacco smoke. Likewise, nicotine patches which adhere to an individual's skin for transdermal absorption of nicotine have also been developed. The object of nicotine supplements is to satisfy an individual's craving for nicotine, without the highly negative health consequences of inhaling tobacco smoke. While nicotine supplements protect the individual from the significant harm that smoking causes by satisfying the need to obtain nicotine without inhaling tobacco smoke, they do not overcome the individual's addiction to nicotine. In addition, once the chewing gum is discarded, or the transdermal patch is no longer used, the craving for tobacco products often returns. As a result, nicotine supplements solve only some of problems associated with smoking. It would be desirable to have a method of weaning an individual away from smoking tobacco, while at the same time minimizing the numerous undesirable side effects of a withdrawal from smoking. [0008] More recently, alternative treatments which do not use nicotine supplements have been developed to assist individuals in breaking the tobacco habit. Nicotine is a neural chemical which attaches to specific cell receptor sites in the brain. Therefore, preventing its ability to attach to these cell receptor sites is one method used to interfere with the addictive qualities of nicotine. One such alternative treatment involves the use of chemical compounds which bind to these cell receptor sites, and thereby prevent nicotine from binding to those cell receptor sites. As a result, the nicotine based cravings of the individual are reduced. A number of anti-smoking compounds have been found to be effective for this purpose. These compounds include alkyl sulfides, colloidal sulfur, hydropersulfides, organic thio compounds or their salts. The preferred thio compounds are thioglycerols, thioglycols or their salts. [0009] One example of a commercially available product containing at least one of these compounds is Sulfonil™. Sulfonil is described in U.S. Pat. No. 4,596,706 as a method of controlling craving for tobacco or controlling tobacco withdrawal symptoms. The product uses bivalent negative sulfur compounds which attach to the individual's cell receptor sites, and thereby prevent nicotine from binding to those same cell receptor sites. [0010] By removing or reducing the ability of the nicotine to bind with cell receptor sites, the smoker can gradually eliminate the addiction to nicotine. However, while products such as Sulfonil help an individual to eliminate the nicotine craving, it does nothing to address the side effects of nicotine withdrawal, namely excessive appetite and unwanted weight gain. It would be desirable to have a product which helps an individual overcome nicotine addiction, and also helps an individual avoid the unwanted side effects of nicotine withdrawal. [0011] Another serious disadvantage associated with the use of tobacco, in addition to the addiction problems discussed above, is the depletion of vitamins, minerals, amino acids, co-factors and neurotransmitters which are a direct result of smoking tobacco products. Depending on an individual's particular body chemistry, and the number and types of vitamins, minerals, amino acids, co-factors and neurotransmitters which are lost due to cigarette smoking, a variety of physical and health problems may arise. [0012] Tobacco smoke is inherently dangerous. However, cigarette smoke can be more so because of the additional factor of the burning paper wrapper that carries the tobacco itself. Cigarette smoke is extremely complex from a chemical point of view. In particular, there are approximately 4,000 chemicals which are present in cigarette smoke. At least 60 of these chemicals are known carcinogens. Further, cigarettes have also been shown to carry toxic and heavy metals which are dangerous to human health. In addition to the obvious dangers associated with carcinogens, cigarette smoke impacts the body's ability to function normally by interfering with important body resources, either directly or from toxic metals. The additional health impact caused by the diminution and depletion of important vitamins, minerals, amino acids, co-factors and neurotransmitters can lead to a wide range of health problems in the smoker. As stated, tobacco is not the only part of the cigarette which carries dangerous chemicals. In particular, the paper used by the cigarette manufacturers has been engineered to burn slowly. This can be accomplished, among other ways, by the addition of antimony to the paper. However, while this makes the paper burn slowly, it also places toxic materials such as antimony into the smoker's body. [0013] In addition to the toxic material ingested when an individual smokes, there is another important side effect which impacts health in a significant way. In particular, there is a significant loss of vital substances, namely vitamins, minerals, amino acids, co-factors and neurotransmitters which are a direct result of smoking. Therefore, in addition to the obvious problems associated with smoking, such as cancer, there is a general loss of vital substances necessary for good health. When individuals attempt to quit smoking, they typically experience problems related to weight gain which impacts health. Likewise, if they do not quit smoking they will experience problems related to loss of vital substances required by the body for good health. It would be desirable to have a single product which would help an individual in both situations. Namely, a product which would help an individual to quit smoking by reducing cravings for nicotine and reducing excessive appetite which is associated with nicotine withdrawal, and simultaneously provide an individual with vital substances needed for good health which will help to replace those vital substances which are lost while smoking. [0014] While the prior art has addressed some of the problems related to cessation of smoking, it has failed to address other problems, such as excessive weight gain, which can occur during the course of withdrawal from nicotine addiction. Likewise, the prior art has failed to provide a product to replenish vital substances lost by the body due to tobacco smoking. It would be desirable to have a product which is capable of addressing the basic problem of withdrawal from nicotine addiction, as well as subsequent withdrawal related side effects such as excessive weight gain which in turn leads to other health problems. Likewise, the prior art has failed to address problems, created by smoking tobacco, which lead to depletion of important body substances which are vital to an individual's health. Namely, vitamins, minerals, amino acids, co-factors and neurotransmitters. SUMMARY OF THE INVENTION [0015] The present invention provides targeted amino acid therapy for placement of losses of neurotransmitters related to tobacco smoking. It provides a compound for the simultaneous treatment of nicotine addiction and undesirable side effects such as excessive appetite and weight gain that occur during the nicotine withdrawal process. The first component of the compound includes at least one bivalent negative sulfur, in an amount sufficient to control the craving or the withdrawal symptoms resulting from nicotine withdrawal. The bivalent negative sulfur is selected from a group that includes, but is not limited to, hydropersulfides, alkyl sulfides, colloidal sulfur, organic thio compounds or their pharmaceutically acceptable salts. The most effective thio compounds have proven to be thioglycerols, thioglycols or their pharmaceutically acceptable salts. [0016] The second component of the compound relates to cravings, appetite suppression, and control of blood sugar. In the preferred embodiment, appetite suppression is accomplished using amino acids derived from tryptophan, such as 5-HTP. 5-HTP and/or related tryptophan derivatives. These are known in the art to suppress appetite and cravings for certain carbohydrates when ingested. The appetite suppression compounds are combined with the bivalent negative sulfur compound(s) to provide a single compound that produces the desirable effect of reducing nicotine craving while simultaneously suppressing increased appetite which is a result of nicotine withdrawal. [0017] The third component of the compound includes a variety of nutritional supplements specifically selected to replenish vital body substances lost as a direct result of tobacco smoking. Some of the vital body substances depleted by tobacco smoking include: (a) vitamin C (ascorbic acid), (b) folic acid/folate, (c) vitamin B12, (d) serotonin, (e) magnesium, (f) vitamin E (e.g. alpha tocopherol, etc.), (g) biotin, (h) melatonin, (i) zinc, (j) selenium, (k) sulfhydryl groups (e.g. cysteine, glutathione), (l) n-acetyl cysteine (NAC) and (m) dopamine. [0018] The cause of the depletion of vital body substances is due to the many toxic substances in tobacco smoke. Cigarette smoke includes heavy metals such as cadmium which causes a variety of health problems. In the case of cadmium, this can be a long-term problem because the body stores it in fat and may retain it for substantial amount of time. Cadmium causes the depletion of zinc. It causes the depletion of vitamin D which has direct and indirect effects on bone turnover. It is nephrotoxic and can interfere with vitamin D metabolism. [0019] It is known that GSH (glutathione) is decreased in smoking and GSH is a tripeptide of glycine, glutamate (glutamic acid) and the all important, cysteine (L-cysteine is not well absorbed in the intestine). NAC is useful because it provides another way to increase intracellular glutathione via elevated intracellular cysteine. [0020] Another health factor created by smoking is a reduction in the amount of vitamin C available to the body. Vitamin C has an effect on blood flow, and a reduction in blood flow caused by reduced amounts of vitamin C can directly impact the health in a number of ways. Tobacco smoke contains nickel which has the effect of reducing available levels of vitamin C in the body. In addition to nickel, tobacco smoke also contains cobalt. Nickel and cobalt has been shown to greatly deplete the level of intracellular ascorbate. [0021] Tobacco smoking also depletes vitamin E in the body. A loss of vitamin E, and a loss of vitamin C contribute to a variety of health problems. In particular, the inflammatory process used by the body can be impacted, and in addition, plasma and urinary CEHCs can be decreased. CEHC (alpha CEHC=apha-carboxy-ethyl-hydroxychroman) is a metabolite of vitamin E. [0022] Tobacco smoking also depletes sulfhydryl groups (e.g. cysteine, glutathione) which impacts adhesion and cellular morphology. [0023] Tobacco smoking depletes brain dopamine. The inventive compound provides tyrosine and phenylalanine which are both precursors to dopamine production. [0024] These compounds are combined with suitable binders to form pharmaceutical capsules that can be administered orally. Alternatively, these compounds can be administered via injection, via transdermal cream, gel or patch, sublingually, via gum or lozenge, or by any other suitable means. In some administration methods, such as gum or lozenge, sweetening agents, such as sugar alcohols, can be added to sweeten the taste without effecting blood sugar levels. Sugar alcohols, such as xylitol, can be used in combination with gums or lozenges to provide sweetness with a lower carbohydrate level than a comparative amount of sugar. As a result, it will not elevate blood sugar levels as much as sugar will. In addition, stevia and agave may also be used as sweeteners. Stevia and agave can both be useful in controlling blood sugar levels. [0025] A therapeutic dosage level is approximately 120 milligrams, twice a day, of the bivalent negative sulfur, and multiple doses of the bivalent negative sulfur may be taken at the same time. Regarding 5-HTP, typical doses would run from a low dosage level of 50 milligrams to a high dosage level of 900 milligrams per day. It is important to note that the dosage level of each component of the compound can vary based on the size/weight of the individual in question, vary based on the tolerance level of that individual for components of the compound, or vary based on the intensity of the craving for nicotine or food. As a result, a small individual, or an individual sensitive to the compound, may achieve adequate results with small dosage levels of 5-HTP (e.g. less than 50 milligrams) per day. Likewise, a large individual, or an individual with a high tolerance level for the compound, may safely take more than what would typically be considered the maximum dosage of 5-HTP (e.g., greater than 900 milligrams) per day. [0026] The treatment uses a compound which addresses both nicotine craving, and appetite control. The first component of the compound is designed to interfere with the ability of nicotine to attach to cell receptor sites, thereby reducing nicotine craving. The other component of the compound is directed to both nicotine craving and appetite control, thereby reducing excessive weight gain associated with withdrawal from nicotine addiction. The various components of the compound act together to assist an individual to quit smoking without the undesirable side effects of nicotine withdrawal, such as increased appetite and unwanted weight gain. [0027] An advantage of tryptophan and tryptophan derivatives derives from the fact that when the body processes a tryptophan derivative such as 5-HTP, the tryptophan derivative is used by the body as a serotonin precursor to increase serotonin levels. It is the increased serotonin level that decreases appetite and craving for food which lead to excessive weight gain. An added benefit provided by serotonin is that it tends to decrease many types of craving, including craving for nicotine. As a result of its general affect on craving, it not only helps suppress appetite which leads to unwanted weight gain, but it also works synergistically with the sulfur based compounds to decrease craving for nicotine. [0028] In addition, the invention provides compounds which supplement and assist the body to replenish and/or rebuild the body's vital substances, such as vitamins, minerals, amino acids, co-factors and neurotransmitters which are lost due to tobacco smoking. Vitamins, minerals, amino acids and neurotransmitters affected include vitamin C (ascorbic acid), folic acid, vitamin B6 (pyridoxal-5′-phosphate, pyridoxal), serotonin, magnesium, vitamin B12, Vitamin E in its various forms (such as alpha tocopherol, etc.) biotin, melatonin, dopamine, selenium (which may reduce the risk of lung cancer), coenzyme Q10 and zinc. DESCRIPTION OF THE PREFERRED EMBODIMENT [0029] Prior to discussing detailed aspects of the invention, a general overview will be provided. The invention provides an improvement over prior art sulfur-based nicotine withdrawal products which block nicotine from binding with cell receptor sites. The prior art has focused its attention on the use of a variety of sulfur based compounds to treat nicotine addiction. However, it has not placed significant emphasis on the side effects associated with nicotine withdrawal. In particular, a frequent side effect associated with smoking cessation is a marked increase in appetite. The increase in appetite often results in an individual having the health benefits associated with cessation of smoking offset by the health hazards produced by excessive weight gain. These are increased insulin levels which can lead to insulin resistance, increased blood pressure, and unfavorable changes in lipid profiles. [0030] The present invention overcomes these problems by providing a single therapeutic compound which simultaneously reduces nicotine craving to assist an individual to cease smoking, and simultaneously suppresses the individual's appetite to avoid unnecessary and undesirable side effects, such as weight gain, associated with the cessation of smoking. [0031] The invention takes advantage of known sulfur based compounds which interfere with the binding of nicotine with cell receptor sites. These compounds, and their method of use, are discussed in detail in U.S. Pat. Nos. 4,416,869 and 4,596,706, which are incorporated by reference herein in their entirety. Applicant's invention improves over these prior art inventions by adding compounds which are specifically designed to reduce the increased appetite which is caused by nicotine withdrawal. Further, the compounds selected to reduce appetite also enhance the body's ability to suppress nicotine cravings. As a result, an individual seeking to cease smoking will not have the additional problems generated by the common side effect of nicotine withdrawal, namely, increased appetite and weight gain. Applicant's invention provides a single dose which is directed to both problems: overcoming nicotine addiction and reducing the side effect of increased appetite during nicotine withdrawal. [0032] In addition to the ingredients that are directed to nicotine withdrawal and appetite suppression, the inventive compound also includes ingredients necessary to replenish and/or rebuild vital body substances, such as vitamins, minerals, amino acids, co-factors and neurotransmitters. Tyrosine and phenylalanine are dopamine precursors which are included in the compound to restore the level of dopamine for the purpose of improving brain function. [0033] Having discussed the features and advantages of the invention in general, we turn now to a more detailed discussion of the figures. [0034] As discussed above, the U.S. Pat. Nos. 4,416,869 and 4,596,706 teach a variety of sulfur based compounds which are useful in the treatment of nicotine addiction. In particular, these patents teach the use of bivalent negative sulfur compounds which are useful for reducing nicotine craving in individual's seeking to cease smoking tobacco products. However, these products do not effectively address side effects related to the cessation of smoking, most notably: unwanted weight gain due to increased appetite. The advantage of Applicant's invention is that it allows an individual to cease smoking without this undesirable side effect. [0035] Applicant's invention provides a new compound which incorporates known compounds in the prior art related to suppression of nicotine addiction with a second compound which combined with those compounds to simultaneously suppress the unwanted increase in appetite which occurs during nicotine withdrawal. Applicant's invention uses derivatives of the amino acid tryptophan to reduce appetite so that an individual can cease smoking tobacco products without the added stress and health hazards related to excessive weight gain. [0036] In the preferred embodiment, both the compounds related to nicotine addiction, and the amino acids used for appetite suppression are combined into a single dose for ingestion by the individual. Those skilled in the art will recognize that these compounds can be administered via a variety of methods, such as pills/capsule ingestion, liquid ingestion, intramuscular injection, intravenous injection, nasal spray, via inhaler, transdermal, suppository, or via powder mixed in a liquid. When used as a liquid, the compound can be administered in combination with any suitable solution, liquid carrier, liquid medium, etc. The only requirement is that liquid selected is suitable for use with the components of the compound. However, while a variety of administration methods can be used (e.g., injection, transdermal patches creams, gels, lozenges, gums, etc.), the preferred embodiment envisions the simple and convenient process of administering the compound via a pill or capsule. [0037] In the preferred embodiment, the tryptophan derivative used by the Applicant is 5-hydroxytryptophan (“5-HTP”), which is a nutrient. It is derived from the amino acid L-Tryptophan. L-Tryptophan plays a vital role in our health. Tryptophan an essential amino acid for building proteins and enzymes, and serves as the precursor for serotonin, and the hydrogen carriers NADH and NADPH. 5-HTP functions as a precursor to serotonin (5-HT, 5-hydroxytryptamine). Serotonin, a neurotransmitter, plays an important role in regulation of mood, appetite, body temperature, and the secretion of various hormones. While serotonin does not readily cross the blood brain barrier, serotonin precursors such as 5-HTP can. Supplementation with this precursor increases levels of serotonin. In addition, 5-HTP is more efficient than L-tryptophan because it bypasses the rate-limiting step of serotonin synthesis (tryptophan hydroxylase). [0038] Tryptophan has a variety of side effects when ingested by humans. It can be used as a mood-enhancer, and it can help individuals sleep. In fact, it has been widely used to treat insomnia and depression. It can increase pain tolerance, and it can also reduce appetite. An advantage of 5-HTP over some other appetite suppressants is that it has small molecule size. The 5-HTP accesses the brain from the bloodstream, and once in the brain, it can be converted into serotonin. It is the serotonin, created from the 5-HTP, acting on the different serotonin receptor sites, which ultimately acts as an appetite suppressant, and helps to reduce cravings for nicotine. A further advantage of 5-HTP over other potential appetite suppressants is that it is a naturally occurring compound which is produced in the body from tryptophan which is found in high-protein foods such as beef, chicken, fish, and/or dairy products. [0039] In the preferred embodiment, the dosage level of 5-HTP ranges from 50 mg per day up to 900 mg per day. 700 to 900 mg of 5-HTP would normally be considered a high dose. Of course, those skilled in the art will recognize that there are many factors that influence the appropriate dosage level for an individual. For example, the size, weight and tolerance of individuals can vary widely. Therefore, an appropriate dosage for one individual may not be safe for another. A large individual may have the ability to use dosage levels well in excess of 900 mg. Some individuals may also have high tolerance levels for particular compounds which will result in the ability to use high dosage levels. Of course the opposite will be true for individuals who are small or particularly sensitive to a given compound. Those individuals may only need a dosage level less than 50 mg. In addition, other factors related to an individual may create higher or lower levels of appetite which would necessitate the change in dosage levels. As a result, unique factors related to each individual should be taken into account when determining the proper levels of each of the components of the compound. [0040] In the preferred embodiment, the compound would be taken twice a day, to maintain stable levels of nicotine suppressant. In addition, it has been found that the appetite suppressant is more effective if taken before or after meals, because it is absorbed by the body more rapidly if taken on an empty stomach. As a result, an individual would preferably take the compound approximately an hour before meals, or approximately 2 hours after meals. Typically, an individual would take a dose twice a day. This would maintain relatively stable levels of nicotine suppressant throughout the day, and will also suppress hunger at the appropriate times. [0041] Because 5-HTP is a precursor used by the body to produce serotonin which suppresses appetite, its use in combination with the aforementioned nicotine suppressant allows an individual to improve the chances of successfully overcoming a tobacco habit. This is because the individual will not have negative side effects such as increased weight gain, which may in fact frustrate the individual to the point where they resume smoking. Due to that, the individual is more likely to succeed when attempting to quit smoking. Of course, avoiding unnecessary weight gain provides many advantages for the overall health of the individual. In addition, because serotonin also inhibits cravings for nicotine, it will synergistically enhance the sulfur based compounds which are directed specifically at reducing nicotine cravings. [0042] In addition to the use of 5-HTP to suppress appetite, other additives may be included in the compound to enhance weight control. For example, there are a number of nutritional supplements which enhance the body's ability to metabolize fat, such as vitamin B12, inositol, methionine, and choline. Additives such as this complement the suppressant of appetite by enhancing the body's ability to metabolize fat. Therefore, these additives would also help reduce the risk of weight gain during smoking cessation. [0043] Inositol, in all of its forms, may be helpful in more than one way. Higher doses may help increase GABA and reduce anxiety. The prior art suggests that Inositol may increase neurotransmitters such as serotonin, and GABA. While medical literature suggests that individuals may safely ingest 1-18 grams per day, the preferred embodiment envisions a dosage level of approximately 0.4-2 grams/day. [0044] Another effective additive is Dopamine, which is a neurotransmitter. L-Tyrosine 100-200 mg twice a day and L or DL-phenylalanine 300 mg a day will increase dopamine along with the B-Vitamins. The addition of the neurotransmitter precursors (tyrosine and phenylalanine) of dopamine may also help decrease cravings for carbohydrates. The L-phenylalanine form may work best. Other optional additives can also be usefully combined with the compound. For example, alpha-lipoic acid helps reduce cravings for sweets, which can contribute significantly to weight gain. Likewise, alpha-lipoic acid, chromium picolinate, the chromium product, Chromium Polynicotinate™, and biotin can be helpful in regulating blood sugar metabolism and may be included in the compound. Research suggests that chromium may help prevent glucose-induced elevation of systolic blood pressure and decreased measures of lipid peroxidation. High serum glucose levels which can also contribute to a destructive process known as glycosylation, also called nonenzymatic glycation, in which glucose molecules bind to proteins and interfere with their function. People with diabetes have a highly increased rate of protein glycosylation and this plays a major part in their increased risk of atherosclerosis and many other diseases. For many with diabetes, chromium enhances the ability of insulin to lower serum glucose levels. In addition to these nutritional supplements, some vitamins, mainly B6, may be used by the body in the process of converting 5-HTP to serotonin. Vitamin B6 also acts as a diuretic which further helps to control weight. Another possible additive is coenzyme Q10. Coenzyme Q10 is produced by the human body and is necessary for the basic functioning of cells. Tobacco smoke can deplete body stores of coenzyme Q10 (CoQ10), but levels of CoQ10 in the body can be increased by taking supplements. [0045] In the preferred embodiment, the following daily doses are taken and used to supplement vital body substances lost because of tobacco smoking: 1. 50-200 mg 5-HTP (Serotonin precursor) 2. 50-250 mg Thioglycerol 3. 50-100 mg Choline Citrate 4. 50-100 mg Pantothenic Acid (as D-Calcium Pantothenate) 5. 400-2000 mg Inositol 6. 50-100 mg L-methionine 7. 200-500 mg Alpha Lipoic Acid 8. 30-500 mg Vitamin B-6 (as Pyridoxine HCl, or any of its other forms) 9. 2-10 gm Vitamin C 10. 800-2000 mcg Folic Acid 11. 800-10,000 mcg Vitamin B12 (as methylcobalamin) 12. 800-1600 mg magnesium (as magnesium citrate or magnesium glycinate) 13. 800-10,000 IU vitamin D3 14. 50-120 mg zinc (as zinc glycinate, picolinate, or citrate) 15. 100-1200 IU vitamin E (alpha-tocopherol and gamma tocopherol) 16. 200-400 mcg selenium (as selenomethionine) 17. 500-4000 mg tyrosine 18. 500-3000 mg phenylalanine (as L or DL-phenylalanine) 19. 300-600 mg coenzyme Q10 20. 0.1-6 mg melatonin 21. 30 mcg-2 mg biotin 22. 600-1200 mg N-acetyl cysteine [0068] Those skilled in the art will recognize that while the aforesaid formula is preferred, changes can be made to the formula without losing its overall effectiveness. Regarding smoking cessation, two components of the compound are important. The first component is 5-HTP which is used to suppress appetite, and reduce cravings for tobacco. In the preferred embodiment, this is administered in an approximate dosage of 200 mg. The second compound is Thioglycerol, which is a sulfur based compound that is used to block nicotine receptor cells. By blocking the receptor cells, nicotine cravings are reduced. The Thioglycerol is typically administered in an approximate dosage of 120 mg. The combination of these two components provides a compound which reduces nicotine cravings while simultaneously reducing appetite. In addition, numerous ingredients listed above, which are intended to replenish vital body substances that are reduced through the use of tobacco can be used singly or in combination with one another. As a result, a single product can be used not only to assist an individual to quit smoking, to avoid the side effects according to tobacco such as weight gain, but simultaneously can be used by smokers to avoid damage done to the smoker's health by tobacco in the form of depletion of important compounds used by the body. [0069] In addition to the two primary components, namely sulfur compounds used to block nicotine receptor cells, and the 5-HTP, which is used to increase serotonin levels of a variety of optional additional components can be used to enhance performance of the product. For example, weight suppression can be further enhanced through the use of Inositol, Vitamin B12 (as Methylcobalamin), L-methionine, and Choline Citrate. They can be used alone or in combination with one another to increase the body's ability to metabolize fat, and thereby helping the body to avoid weight gain. B vitamins, such as vitamin B-6 (as Pyridoxine HCl), Pantothenic Acid (as D-Calcium Pantothenate), and Folic Acid are precursors to, or co-factors for neurotransmitters, which will decrease cravings for certain carbohydrates. Alpha Lipoic Acid is helpful in stabilizing blood sugar levels. Magnesium Citrate may help to reduce anxiety. [0070] Those skilled in the art will recognize that as is the case with any pharmaceutical or neutraceutical, appropriate dosages will vary based on several factors. A person's weight, age, physical condition, etc., will all influence what the proper dosage for a particular individual should be. As a result, while the foregoing dosages are envisioned as an appropriate starting point, changes can be made to suit particular individuals. [0071] While the invention has been described with respect to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in detail may be made therein without departing from the spirit, scope, and teaching of the invention. For example, the compound used to suppress appetite can vary so long as it is suitable for its purpose, the amount of the appetite suppressant can vary based on an individual's physical requirements. The type of administration can vary from pill/capsule/powder form to liquid form, injection, transdermal patch, creams, gels, gums, lozenges, sublingual administration, etc. In addition, the dose and frequency of administration can vary based on the number of daily meals, severity of withdrawal systems, the weight and condition of the individual, etc. [0072] In addition, the invention provides compounds which supplement and replace vital substances, such as vitamins, minerals, amino acids, co-factors and neurotransmitters which are lost due to tobacco smoking. Substances replaced or supplemented by this invention include vitamin C (ascorbic acid), folic acid, vitamin B6 (pyridoxal-5′-phosphate, pyridoxal), serotonin, magnesium, vitamin B12, vitamin E (Alpha tocopherol), Biotin, melatonin (a hormone and antioxidant), and zinc. Some substances, such as zinc and magnesium, can be absorbed by the body in several forms. For example, zinc can be absorbed as zinc glycinate, zinc picolinate, or those zinc citrate. [0073] Cigarette smoke contains, among other things, lead, cadmium, nickel and antimony. One of the side effects of metals, such as lead, is that it decreases the dopamine levels in the body. That's why tyrosine and phenylalanine are included in the formula. They are dopamine precursors which the body uses to replace the dopamine that is lost due to smoking. In addition to lead, the cadmium which is found in cigarette smoke diminishes zinc levels in the body. Cadmium can be transferred into the fat cells and stored in the body for a substantial period of time. Further, cadmium can have direct and indirect effects on bone turnover, it can interfere with vitamin D metabolism, and it is a nephrotoxin. [0074] It is also known that serotonin is excreted in urine at a higher rate in smokers than in non-smokers. As a result, by supplementing with 5-HTP, the body is better able to generate more serotonin to replace that lost due to tobacco use. [0075] Vitamin C levels are also reduced due to tobacco smoking. For example, the nickel in tobacco smoke interferes with vitamin C which is used by the body to improve blood flow. Likewise, Vitamin E has been shown to disappear faster in blood plasma of smolders as opposed to non-smokers. [0076] Those skilled in the art will recognize that while the aforesaid formula is preferred, changes can be made to the formula without losing its overall effectiveness. Two components of the compound are the most important. The first component is 5-HTP which is used to suppress appetite. In the preferred embodiment, this is administered in an approximate dosage of 200 mg. The second compound is Thioglycerol, which is a sulfur based compound that is used to block nicotine receptor cells. By blocking the receptor cells, nicotine cravings are reduced. The thioglycerol is typically administered in an approximate dosage of 120 mg. The combination of these two components provides a compound which reduces nicotine cravings while simultaneously reducing appetite. [0077] The formula used above the combination of ingredients designed to address several problems created by tobacco smoking. By providing substantial amounts of these depleted substances, a smoker can replenish and restore the substances to more optimal levels for improved health. As a result, the user is able to prevent additional damage caused by tobacco due to the depletion of these substances. Those skilled in the art will recognize, as was the case above, that the exact dosage for every individual will vary based on factors such as body weight, age, smoking history, general health, etc. Likewise, those skilled in the art will also recognize that the formula used above can be combined with any of the above-described smoking cessation compounds such that while individuals are fighting their addiction to tobacco, they can simultaneously help their bodies maintain proper levels of vitamins, minerals, amino acids, co-factors and neurotransmitters. [0078] Those skilled in the art will recognize that the invention includes compounds which may be used alone or in combination with smoking cessation embodiment, discussed above. As previously discussed, the heavy metals found in tobacco smoke, such as cadmium, can produce a number of undesirable side effects. For example, cadmium from tobacco smoke reduces brain dopamine, and possibly numerous other vital body substances which are necessary for health. As a result, it may be desirable to add additional components to the formula in order to compensate for these losses.

A compound for the simultaneous treatment of nicotine addiction, the side effects of nicotine withdrawal, such as excessive appetite, and detrimental health effects caused by loss of vital body substances such as vitamins, minerals, amino acids, co-factors and neurotransmitters which result from tobacco smoking. The first component is a bivalent negative sulfur compound from a group that includes, but is not limited to, alkyl sulfides, colloidal sulfur, hydropersulfides, organic thio compounds or their salts. The second component is a replenishment formula which is used to correct losses of those substances caused by tobacco smoke. The first and second components can be used alone, or in combination.

BACKGROUND OF THE INVENTION This application relates to a control for a heating, ventilation and air conditioning (HVAC) system wherein the control takes in demands from several zones, and determines which of several capacity stages are appropriate given the existing demands. In particular, the present inventive control better meets the demand in that it considers the existence of demand over time in determining whether to change the stage. HVAC controls are becoming more sophisticated. A basic HVAC control is operable to take in a requested temperature, and compare a requested temperature, or set point, to an actual temperature. The difference is known as the demand. A control then controls the heating or cooling equipment to meet that demand. More sophisticated systems have several zones, each of which may have an individual demand. As an example, several rooms within a building may each have a set point control that allows a user to select a desired temperature for that particular zone. Each zone may have a sensor to sense the actual temperature. The difference between the desired temperature, or set point, and the actual temperature is known as the zone demand. The demands from the several zones are sent to a control, and the control evaluates how to meet those several demands. One other feature of modern HVAC systems is that the heating or cooling equipment has several available capacity stages. To ensure the most efficient operation, the control would tend to operate the heating or cooling equipment in the lowest stage that can adequately meet the demand. As the demand increases, then the stage would also increase. Examples of stages might be a furnace provided with several optional heating elements, or an air conditioning system that can be operated in several different capacity modes. In the prior art, a control for determining the recommended stage looks at a variable known as the system demand. In this prior art control, the system demand is taken from the various zone demands across the system, and calculated utilizing a particular formula. The system demand is considered by a stage control algorithm that selects a desired stage based upon the system demand. The stage control algorithm takes the system demand and multiplies it by some multiplier. The output of this multiplication is a requested stage number. Thus, as the system demand increases, the indicated stage would also increase. This known control is well suited for low load operations, and when operating at low stages. However, the known control has the potential problem of allowing “droop.” Droop occurs when the system is unable to fully meet the demand, but is within a degree or two of the set points. Particularly when operating at a high stage with the known control, a few degrees difference may never be sufficient to move into the next higher stage operation. Thus, the system can operate for long periods of time without ever fully meeting the demand. It would be desirable to provide a stage control algorithm that is better suited for actually meeting the demand. One simple HVAC system does include a control for determining a recommended stage that looks not only to a current demand, but also to the existence of a demand over time, or the integral of the demand. This control, however, has not been associated with a multiple zone HVAC system. Instead, the known control only provided a control in a single zone system. SUMMARY OF THE INVENTION In a disclosed embodiment of this invention, the stage control algorithm for determining a staging demand incorporates a quantity indicative of the amount of demand over time. Stated mathematically, an integral of the demand is considered in the stage control algorithm. In one embodiment, the staging demand is determined by a stage control algorithm that multiplies the system demand by one multiplier, and takes the cumulative sum of system demands over some period of time and multiplies that sum by another multiplier. With this stage control algorithm, the problem of droop is avoided in that a demand existing over a period of time, provides sufficient weighting to move the staging demand to higher stages. One other feature that is modified by this invention from the prior art control is the way the system demand is calculated. The prior art system demand took the totality of system demands across the zone, and further the highest positive demand for any one zone and utilized the formula to calculate the system demand. Since the present invention is utilizing the integral of the system demands over time, there is the possibility of both positive and negative system demands. Thus, the present invention utilizes a system demand formula which weights the greatest absolute value zone demand. Further, while in the disclosed embodiment, the consolidation of the several zone demands occurs prior to taking the integral, it is also possible that the integral is taken on the individual zone demands, with the current and integral signals for each zone then being consolidated. However, applicant believes this may be the more challenging approach, and thus utilizes the consolidated signal as the term that is used in the integral calculation in the disclosed embodiment. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a control for an HVAC system. FIG. 2 shows the effect of the prior art control algorithm. FIG. 3 schematically shows the staging increase with the inventive control algorithm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An HVAC system control 10 is illustrated in FIG. 1 . Controls for four zones are shown as 11 , 12 , 14 and 16 . Each of the zone controls 11 , 12 , 14 , 16 has a sensor 18 for sensing actual temperature and a control 20 allowing a user to input a desired or set temperature for that zone. Each of the zone controls 11 , 12 , 14 and 16 then send a signal, or signals, to the control 10 . Control 10 is illustrated incorporating logic steps, including the demand weighting and consolidation control step 22 . The control 10 may be a microprocessor, although other types of appropriate controls may be utilized. Signals from the zones are sent to control 10 to provide an indication of the difference between the set point and actual temperature. This difference is known as the zone demand. When the system is “on” or conditioning air, the zones that are incorporated into the control include all zones with a damper that is at least partially open. When the system is in an “off” mode, or not conditioning air, then all zones having a demand are utilized in this calculation. At step 22 , the zone demands are consolidated into a system demand. In the prior art, system demand was taken from the demands from the zone, with a weighted increase for the greatest positive zone demand. A “positive” zone demand would be where the actual temperature is below the set point in heating mode, or wherein the actual temperature is above the set point in a cooling mode. The formula used was as follows: System Demand=[(the sum of demands from zones which have demand)/(the number of zones having demand)+(the greatest zone demand)]/2. This system demand is then sent to a control step 23 for determining the stages requested, or the staging demand. The stage control algorithm for determining staging demand in the prior art simply applies a multiplier to the system demand. The actual prior art control utilizes a multiplier of 2, with a hysteresis of one stage. The result is that a first stage of equipment is turned on with 0.5 degree weighted average error and turned off when the weighted average error is zero. As shown in FIG. 2 , an increasing amount of system demand is thus required to result in a greater staging demand, as the stages increase. In order to turn on the fifth stage, a relatively large average error of 2.5 degrees is needed. Thus, if the system is operating in fourth stage, there could be an average error of 2 degrees, as an example, that could exist for long periods of time. This was a deficiency in the prior art as mentioned above. The present invention addresses this problem by considering system demands over time in determining a staging demand. In one embodiment, the staging demand is determined as follows: Staging ⁢ ⁢ Demand = ⁢ 2 ⁢ ( Current ⁢ ⁢ System ⁢ ⁢ Demand ) + ⁢ ( 1 / 24 ) ⁢ ( the ⁢ ⁢ cumulative ⁢ ⁢ sum ⁢ ⁢ of ⁢ System ⁢ ⁢ Demands ⁢ ⁢ calculated ⁢ ⁢ once ⁢ ⁢ per ⁢ ⁢ minute ⁢ ⁢ starting ⁢ ⁢ when ⁢ ⁢ the ⁢ ⁢ equipment ⁢ ⁢ ⁢ was ⁢ ⁢ last ⁢ ⁢ turned ⁢ ⁢ on . ⁢ Since there would be 60 of the system demands taken into the cumulative sum number per hour, the total multiplier is effectively 2.5 of the average system demand over that time. Of course, other multipliers can be utilized, and other time periods, both longer or shorter, can be utilized in the integral portion. As shown in FIG. 3 , the present invention is able to move up to as high as a fifth stage (or even more) with relatively small system demands (e.g., 0.25 degrees). Thus, the present inventive control will not continue to operate for long periods of time with the average zone demand being a few degrees away from the desired set point, no matter the “current” stage of operation. With the use of an integral term, over-conditioning should allow the integral term to move negatively. Since the prior art control only turned the equipment on to a higher stage when a sufficiently large demand existed, and turned it off when the demand went to zero, a negative demand was not a problem. However, when the integral term is used, the system demand must average to zero (so that the integral term will be constant), to keep the staging demand constant. This means the system demand should be allowed to become either positive or negative. The prior art system demand, which weighted the zone with the greatest positive zone demand, is no longer best suited for this control. The prior art system demand formula was calculated as follows: System ⁢ ⁢ Demand = ⁢ [ ( the ⁢ ⁢ sum ⁢ ⁢ of ⁢ ⁢ demands ⁢ ⁢ from ⁢ ⁢ zones ⁢ ⁢ which ⁢ have ⁢ ⁢ demand ) / ⁢ ( the ⁢ ⁢ number ⁢ ⁢ of ⁢ ⁢ zones ⁢ ⁢ having ⁢ ⁢ demand ) + ⁢ ( the ⁢ ⁢ greatest ⁢ ⁢ positive ⁢ ⁢ zone ⁢ ⁢ demand ) ] / 2. As the system moves towards a stage down point, the “greatest positive zone demand” is most likely a small positive demand whereas a much larger negative demand would exist elsewhere. Yet, in the prior art formula, the small positive demand was the most heavily weighted. With the present invention, the system demand is changed to the following: System Demand=[(the sum of demands from zones which have demand)/(the number of zones having demand)+{the greatest zone demand}]/2. The quantity in the { } is intended to mean the zone demand which has the largest absolute value. Thus, as the system approaches turn off, the output of the above equation snaps negatively when the largest negative zone demand just exceeds the largest positive zone demand. When passed through the staging calculation, the first (proportional) term of the staging demand would also cause the staging signal to snap negatively. Thus, staging down normally occurs when the largest positive zone demand just equals that of the most over-conditioned zone, or the largest negative zone demand. As shown in FIG. 1 , there is a staging control step 25 to control heating/cooling equipment 27 . As also shown schematically in FIG. 1 , ducts 30 lead from the heating or cooling element to send air to the various zones in an attempt to meet the set points. The staging control steps include several controls for controlling changes in the staging. This staging control can be generally as known in the art, and may include several timers. A cycle timer may prevent the same stage from turning on within a period of time (e.g., 15 minutes) from the last time it was turned on. This is intended to limit cycling between the same two stages to four times per hour to prevent excessive equipment cycling. During the time the staging timer is preventing staging up, the integral term is not updated in the inventive stage control algorithm. This is intended to prevent any “integrator wind-up” which is a potential problem with PI controls. Further, a staging timer of 10 minutes normally prevents staging up at a rate of more than 10 minutes per stage, regardless of the number of stages requested. This prevents excessive staging when a set point is initially changed. Also, a minimum on-timer of three minutes ensures that once a stage is turned on, it will remain on for at least three minutes. The present invention, as disclosed, is able to better deal with eliminating long-term zone demands, and ensure that the actual proper stage is achieved. The present invention is thus able to operate at high loads, while still accurately achieving the set points. Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

A control for controlling a multi-zone HVAC system, wherein the heating or cooling equipment is operable in multiple stages, takes the demand on the system over time into account when determining an appropriate stage. In particular, a time integral of the system demands is utilized along with a current system demand to determine an appropriate stage. In this manner, a weakness in the prior art of allowing a long-term, small difference between the desired set point and the actual temperature in the various zones is addressed.