The present invention provides a speech signal compression device which allows a storage capacity of data representing speech to be efficiently compressed. In the present invention, a computer C1 operates with respect to speech data to be compressed into speech data for each phoneme on the basis of phoneme labeling data, to unify the time length of a unit pitch section for each of the divided speech data into the same value, thereby creating a pitch waveform and creating a sub-band data representing variation in time of spectrum components of the pitch waveform signal. Also, this sub-band data is compressed so as to match a condition designated by a table for compression, and the compressed data is further encoded in entropy to output the entropy coded data.

The present invention relates to a speech signal compression device, a speech signal compression technique and a program.
Recently, a speech synthesis method for converting text data and the like to speech has been used in the field of car navigation, for example.
In speech synthesis, for example, words, basic blocks and modification relations among the basic blocks included in text data are identified, and the way of reading the sentence is identified based on the identified words, basic blocks and modification relations. Then, the waveform, the duration and the pitch (fundamental frequency) pattern of phonemes to constitute speech are determined based on the phonogram sequence indicating the identified way of reading. Then, the waveform of speech indicating the entire sentence including kanjis and kanas is determined based on the result of the determination, and speech with the determined waveform is outputted.
In the above-mentioned speech synthesis method, in order to identify a speech waveform, a speech dictionary is searched in which speech data indicating waveforms or spectral distribution of speeches have been accumulated. The speech dictionary is required to have a great number of speech data accumulated therein in order to make synthesized speech natural.
In addition, when this method is applied to a device required to be downsized, such as a car navigation device, it is generally necessary to downsize a storage device for storing a speech dictionary to be used by the device. When the size of the storage device is decreased, decrease of the storage capacity is generally unavoidable.
Accordingly, in order to enable a speech dictionary with a sufficient amount of speech data included therein to be stored in a storage device with a small storage capacity, data compression of speech data has been used to reduce the data capacity of one speech datum (see National Publication of International Patent Application No. 2000-502539, for example).

Speech signal compression device, speech signal compression method, and program


A semiconductor device formed by decreasing thickness of a substrate by grinding, and performing ion implantation. In a diode in which a P anode layer and an anode electrode are formed at a side of a right face of an N− drift layer, and an N+ cathode layer and a cathode electrode are formed at a side of a back face of the N− drift layer, an N cathode buffer layer is formed thick compared with the N+-type cathode layer between the N−-type drift layer and the N+ cathode layer, the buffer layer being high in concentration compared with the N− drift layer, and low compared with the N+ cathode layer. When a reverse bias voltage is applied, a depletion layer is stopped in the middle of the N cathode buffer layer, and thus prevented from reaching the N+ cathode layer, so that the leakage current is suppressed.

1. Field of the Invention
The present invention relates to a semiconductor device decreased in thickness by a backgrinding process of a semiconductor substrate, and a method of manufacturing the device.
2. Description of Related Art
As a method of manufacturing a power semiconductor device such as a diode or an insulated gate bipolar transistor (hereinafter, referred to as IGBT), the following method is known. First, a semiconductor device is manufactured using a wafer such as silicon wafer while it has a large thickness. Then, the wafer is decreased in thickness to have a final thickness by grinding and etching, and then subjected to ion implantation and activation heat treatment (for example, refer to JP-T-2002-520885, where the term "JP-T" as used herein means a published Japanese translation of a PCT patent application). Such a manufacturing method is becoming mainstream in recent years.
However, in this manufacturing method, since an electrode has already been formed on a surface of the wafer at a side opposite to a side of a surface that was ground, heat treatment must be performed at low temperature, at or below a melting point of the material of the electrodes, for example, at a temperature of 450° C. or less if the electrode material is aluminum, in the activation heat treatment after grinding. Therefore, it is hard to sufficiently activate impurities.
Thus, the applicant has proposed a method of activating an ion-implanted impurity by irradiating high-energy laser light such as YAG second harmonic (YAG2ω) upon an ion implantation surface instead of heat treatment in this manufacturing method (for example, refer to JP-A-2005-223301 and JP-A-2005-64429). According to this method, since energy can be applied only to a region in an appropriate depth from a laser irradiation surface, the impurity can be activated without adversely affecting the previously formed electrode.
For example, a diode in a withstand voltage class of 1200 V is fabricated as follows. First, a P-type anode layer or an aluminum electrode to be an anode electrode is formed on a right face of an N-type FZ (floating zone) silicon wafer having a thickness of about 500 μm and resistivity of about 60 Ωcm. Then, the wafer is subjected to grinding from a back face, so that the thickness of the wafer is made to be 140 μm. Then, the ground surface is chemically polished by wet etching using nitro-hydrofluoric acid. Then, phosphorous is ion-implanted into the polished surface.
Then, such an ion-implanted surface is irradiated with YAG 2ω laser light by a double pulse method setting an energy density of 4 J/cm2 and a delay time of 300 nanoseconds, so that the phosphorous is electrically activated, thereby forming an N+ cathode layer. Here, the double pulse method is a method where a plurality of pulse laser beams are continuously irradiated from a plurality of laser irradiation devices with irradiation timing being staggered by predetermined delay times for each irradiation area of laser light. The double pulse method is described in detail in the JP-A-2005-223301.
Moreover, a diode in which an impurity concentration of a drift layer has a profile that the concentration gradually decreases from the neighborhood of the center of the drift layer to the anode and cathode layers, and an IGBT in which the impurity concentration of a drift layer has a profile such that the concentration gradually decreases from the neighborhood of the center of the drift layer to emitter and collector layers are known (for example, refer to JP-A-2005-64429 and JP-A-2003-318412). A diode or IGBT having such an impurity concentration profile has properties of both a high-speed and low-dissipation and exhibits a soft recovery property.
Furthermore, a semiconductor element is known, in which a P-type anode layer is formed at one end of an N-type semiconductor substrate in low concentration, and an N-type cathode layer in comparatively high concentration is formed at the other end; an i layer is formed between the anode and cathode layers; and an N-type impurity layer in low concentration compared with the cathode layer is provided between the cathode layer and the i layer (for example, refer to JP-A-2000-223720). Moreover, a power diode is known, in which an N-type internal region, and an N-type cathode region following the internal region and having high doping concentration compared with the internal region, and a P-type anode region following the internal region and having high doping concentration compared with the internal region are provided, and an N-type floating region having high doping concentration compared with the internal region is provided in the internal region (for example, refer to JP-A-11-26779).
However, such a diode or IGBT, which is fabricated by the method in which one surface of a semiconductor substrate is ground, and a cathode layer of the diode or a collector layer of the IGBT is formed on such a ground surface, exhibits a problem in that the probability of defective articles is high in measurement of electric characteristics in a wafer state before being cut into individual chips, that is, production yield is low. For example, when a leakage current of an element at a reverse bias voltage of 1200 V of a diode (hereinafter, referred to as reverse leakage current) was measured in the wafer state, many elements showed a leakage current of 10 μA/cm2 or more with respect to a criterion of 1 μA/cm2 or less, and the production yield was 60% or less.
The problem of generation of such a reverse leakage current has not been noticed in the past. Therefore, it should be appreciated that the patent references referred to above do not suppose generation of the reverse leakage current at all. Therefore, there is no description of the reverse leakage current or description of a measure for the reverse leakage current therein.
It is desirable to provide a semiconductor device showing a small reverse leakage current, the device being fabricated by decreasing the thickness of a semiconductor substrate by grinding, then performing ion implantation to such a ground surface and thermal activation of an implanted element. Moreover, it is desirable to provide a method of manufacturing a semiconductor device, in which a semiconductor device showing a small reverse leakage current is fabricated by decreasing thickness of a semiconductor substrate by grinding, then performing ion implantation to such a ground surface and thermal activation of an implanted element.
As a result of earnest study, the inventor discovered the following. When a scratch is formed on a ground surface (ion implantation surface) of a semiconductor substrate, or a particle caused by grinding remains thereon, since phosphorous as an N-type impurity is not normally ion-implanted into the ground surface, a cathode layer in high concentration may not be uniformly formed.
That is, when the particle remains, the particle blocks the phosphor, and the phosphor is not sufficiently implanted into the substrate, therefore a cathode layer in high concentration is not formed. Moreover, when a scratch having a size of a trajectory of an ion or more is formed on an implanted surface after ion implantation, an N+ high-concentration layer is not formed in a portion of the scratch and therefore an exposed portion of the substrate is formed. When a high reverse bias voltage is applied to an element having such a defect, a depletion layer expands into an N− drift layer, and reaches an electrode at the site of the defect, therefore the reverse leakage current is increased. The present invention overcomes these problems.

Semiconductor device and method of manufacturing the same

Fuji Electric Device Technology Co., Ltd.


An iridium oxide local interconnect method for a ferroelectric memory cell includes the steps of forming a conductive layer that extends from a source/drain contact of the transistor proximate to an electrode contact of the ferroelectric capacitor and forming an iridium oxide local interconnect extending from the source/drain contact of the transistor to the electrode contact of the ferroelectric capacitor. The conductive layer is laterally terminated not less than one-half micron from the electrode contact of the ferroelectric capacitor. The conductive layer can include an upper iridium layer and a bottom titanium nitride layer, or can include a single layer of completely reacted titanium nitride. After the local interconnect is formed a top oxide layer is deposited. A late recovery anneal is then performed in oxygen at an elevated temperature to rejuvenate the electrical characteristics of the ferroelectric capacitor. Finally, a bit line contact is opened and metalized.

This invention relates generally to ferroelectric memory cells. More particularly, the present invention relates to an iridium oxide local interconnect method and a corresponding ferroelectric memory cell.
A one-transistor, one-capacitor ("1T-1C") ferroelectric memory cell 10 is shown in schematic form in FIG. 1. Memory cell 10 is a three-terminal device having a bit line node 12 and a word line node 14, in similar fashion to a DRAM cell, but in addition, having a plate line node 16 for poling a ferroelectric capacitor 20. Memory cell 10 includes an MOS transistor 18, the gate forming the word line node 14, and a source/drain forming the bit line node 12. One electrode of ferroelectric capacitor 20 is coupled to the other source/drain of transistor 18 at intermediate node 19, and the other electrode of ferroelectric capacitor 20 forms the plate line node 16. Memory cell 10 is typically included in an array of such cells, not shown in FIG. 1, arranged in rows and columns.
In the prior art, a "local interconnect" or short metal strap is used to physically form the intermediate node 19 in an integrated circuit implementation of memory cell 10. A common material used in such a local interconnect is titanium nitride ("TiN") because of its low resistivity and ability to interface with both silicon and platinum. One problem with titanium nitride is that this material can cause water molecules found in oxide layers to dissociate into hydrogen and oxygen ions. Oxide layers are commonly used in the fabrication of integrated circuit ferroelectric memory cells, therefore hydrogen can come into contact with the dielectric layer of the ferroelectric capacitor 20 as a result of water or hydroxyl ion dissociation. It is well known that hydrogen can cause the electrical performance of ferroelectric materials to degrade, by reducing or entirely eliminating the switched charge necessary for discerning a valid data state. The production of hydrogen and consequent degradation undesirably increases at elevated annealing or packaging temperatures above 400.degree. C.
Iridium oxide is known as an electrode material in the prior art, but it does not form a reliable ohmic contact directly with silicon. Iridium oxide is therefore not recommended as the sole local interconnect material.
What is desired, therefore, is a method for forming a low resistivity local interconnect for a ferroelectric memory cell that will not degrade the performance of the ferroelectric dielectric layer, even at elevated temperatures above 400.degree. C.

Method of forming iridium oxide local interconnect


The present invention relates to 2,4,5-trisubstituted thiazole compounds of formula (I) or all possible isomers, prodrugs, pharmaceutically acceptable salts, solvates or hydrates thereof for the inhibition of plasma PLTP activity and/or plasma CETP activity, wherein the substituents are as defined in the specification; a process for the preparation of the compounds of formula (I); a pharmaceutical composition comprising the compound of formula (I) and its use for the preparation of a medicament for treatment and/or prevention of diseases associated with the increased plasma PLTP activity and/or the increased plasma CETP activity in a mammal, such as atherosclerosis, cardiovascular diseases and peripheral vascular diseases, etc.

Diseases induced by atherosclerosis are the first death cause in developed countries. In China, with the development of social economy and the aging of population, morbidity and mortality of cardio-cerebrovascular diseases have increased significantly in recent years. The origin and pathology of atherosclerosis are complex and have not been elucidated completely at present, but it is known that they are closely related to following factors: blood-fat abnormality, hypertension, diabetes, obesity, smoking, and so on. In these factors, the most important factor to induce the formation of atherosclerosis is blood-fat abnormality. Blood-fat abnormality mainly appears as the rise of LDL cholesterol level and descent of HDL cholesterol level.
Phospholipid transfer protein (PLTP) was called as fat transfer protein II previously, it is glucoprotein present in blood plasma and can mediate the net transfer and exchange of phospholipids between phospholipid vesicle and high-density lipoprotein (HDL) and between main lipoproteins. PLTP contains 476 amino acids residues distributing in all tissues. It exhibits high expression in placenta, pancreatic gland, fat tissue and lung, and low expression in liver, kidney and heart. Its biological synthesis is mainly completed in liver and fat tissue. There are two kinds of PLTP in blood plasma, one of which is high activity form (binding to apo E), and the other is low activity form (binding to apo A-I). The high activity form accounts for 46% in blood plasma (Tol, A. V. 2002; Janis M. T., Siggins S., Tahvanainen E., et al. J. Lipid. Res. 2004; 45(12):2303-2309). PLTP plays a very important role in the metabolism of lipoprotein.
PLTP has three principal actions in the metabolism of lipoproteins: the first action is phospholipid transfer activity, i.e., transferring phospholipids from surface remaining particles of chylomicron, very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) in lipolysis to HDL to increase HDL particles; the second action is remodeling HDL, i.e., regulating the particle size and subclass composition of HDL, mediating the fusing of two HDL3 particles, producing macrobeads of HDL2 and pre-β-HDL, moreover, phospholipid transfer is precondition to remodel HDL, pre-β-HDL is an effective acceptor of cholesterol during antiport of cholesterol; the third action is to regulate liver cells to secrete apolipoprotein B (apoB), to increase the content of VLDL in blood, PLTP deficiency leads to the reduction of VLDL secretion. Besides, PLTP participates in the transfer of vitamin E from lipoprotein to cell membrane, if its activity is reduced, it can increase the VE content in lipoproteins (VLDL and LDL) containing apo B, and antioxidation action of lipoproteins is improved; PLTP further has the activity to transfer lipopolysaccharide to enhance the response of organism to inflammation (Huuskonen J., Olkkonen V. M., Jauhiainen M., Ehnholm C. Atherosclerosis 2001, 155, 269-281; Albers J. J., Cheung M. C. Current Opinion in Lipidology 2004, 15, 255-260; Huuskonen J., Olkkonen V. M., Ehnholm C. et al. Biochemistry 2000, 39, 16092-16098).
PLTP and CETP both belong to fat transporting/lipopolysaccharide binding protein family. The protein family has four members, the other members are bactericidal permeability increasing protein (BPI) and lipopolysaccharide binding protein (LBP)). CETP was called as fat transfer protein I previously, which mediates the transfer of neutral fats such as cholesterol ester, etc. from HDL to LDL, and consequently reduces the particles of HDL. It has been found that human heritage deficiency of CEPT leads to significant rise of HDL level and moderate descent of LDL level, and thereby the research and development of CETP inhibitors have been initiated (Brown M. L., Inazu A., Hesler C. B. et al. Nature 1989, 342, 448-451). Clinic studies showed that CETP inhibitors can elevate HDL, and thus can be used for prevention and treatment of atherosclerosis. CETP inhibitors Torcetrapib (Brousseau M. E., Schaefer E. J., Wolfe M. L. et al. N. Engl. J. Med. 2004, 350, 1505-1515) and JTT-705 (de Grooth G. J., Kuivenhoven J. A., Stalenhoef A. F. et al. Circulation 2002, 105, 2159-2165) have been respectively in III and II phases of clinic trials. In III phase of clinic trials, Torcetrapib is used in combination with Atorvastatin for anti-atherosclerosis and treatment of blood fat abnormality.
In these four members, only X-ray diffraction crystal structure of human BPI has been reported. The crystal structure of BPI has shown that it is in boomerang shape, consists of two subunits, and takes on pseudosymmetric structure. In two concave surfaces of the boomerang, there are respectively two non-polar pockets, which each binds one lecithin molecule, mainly interacts with acyl chain of phospholipids, therefore it has been presumed that BPI binds the acyl chain of lipopolysaccharides. From the structure of BPI can be supposed the mechanism for the fat conveying protein family to convey fat, in which two non-polar pockets are its main functional structure (Beamer L. J., Carroll S. F., Eisenberg D. Science 1997, 276, 1861-1864). Huuskonen et al. have homologically modeled the structure of PLTP with BPI as template protein. Research on amino acid directed mutagenesis has shown that the N-terminal pocket of PLTP is very important to phospholipid transfer activity, and the C-terminal pocket thereof mainly functions to bind HDL (Huuskonen J., Wohlfahrt G, Jauhiainen M. et al. J. Lipid Res. 1999, 40, 1123-1130; Ponsin G., Qu S. J., Fan H. Z. et al. Biochemistry 2003, 42, 4444-4451).
Research results in epidemiology have shown that PLTP content in blood plasma of patients suffering from coronary artery diseases is remarkably higher than that of control group (25.5 vs 22.4 pmol/μL/h; P<0.0001). The probability of one-fifth of the patients in which the PLTP content in blood plasma is the highest suffering from coronary artery diseases is 1.9 times more than that of one-fifth of the patients in which the PLTP content in blood plasma is the lowest. Multivariable regression analysis has shown that after the correction of the factors such as age, blood plasma fat, smoking, diabetes, hypertension, etc. PLTP activity is an independent factor affecting the anticipation of coronary heart diseases. The rise of phospholipid transfer protein level in blood plasma is a danger factor of coronary artery diseases (Schlitt A., Bickel C., Thumma P. et al. Arterioscler Thromb. Vasc. Biol. 2003, 23(10), 1857-62). Blood plasma PLTP activity is elevated in the patients suffering from diabetes I stage and II stage, obesity and insulin tolerance symptoms (Tol, A. V 2002).
The PLTP activity level in blood plasma of transgenic mice in which human PLTP is over-expressed elevated by 2.5-4.5 times, so that blood plasma HDL cholesterol level is reduced by 30-40% as compared with that of wild type animals, and simultaneously the capability of formatting pro-β-HDL is enhanced (Van Haperen R., van Tol A. Vermeulen P. et al. Arterioscler Thromb Vasc Biol. 2000, 20, 1082-1088). Over-expression of PLTP in heterozygote mice with deficiency of LDL receptors causes PLTP activity to be increased by 1.3-2 times, thereby dose-dependently increasing the damage of atherosclerosis (Yang X. P., Yan D., Qiao C. et al. Arterioscler Thromb. Vasc. Boil. 2003, 23, 1601-1607).
The secretion of apolipoprotein B in PLTP gene knockout mice liver was reduced, which causes the secretion of VLDL to be decreased and anti-oxidation capability of lipoprotein to be enchanced, thereby the anti-inflammation action of HDL is improved, and the damage which suffer from coronary artery diseases is significantly decreased (Jiang X. C., Zhou H. W Curr. Opin. Lipidol. 2006, 17, 302-308; Jiang X. C., Qin S., Qiao C. et al. Nat. Med. 2001, 7, 847-852). Feeding mice with deficiency of PLTP with high fat food did not cause blood plasma lipoprotein abnormality, but interfered the transfer of all main blood plasma phospholipids from VLDL to HDL, thereby remarkably reduced HDL level (Jiang, X. C.; Bruce, C.; Mar, J. et al. J. Clin. Invest. 1999, 103, 907-914). The secretion of VLDL in the liver of mice in which PLTP is over-expressed is increased by 48%, this proves from opposite aspect that the crucial action of PLTP to the secretion of VLDL (Lie J., de Crom R., van G. T. et al. J. Lipid Res. 2002, 43(11), 1875-80). The causes for PLTP deficient state to enhance anti-oxidation capability of blood plasma lipoprotein are the increase of vitamin E accumulation and the increase of the bioavailability of vitamin E in lipoproteins (LDL and VLDL) inducing atherosclerosis (Jiang X. C., Tall A. R., QIn S. et al. J. Biol. Chem. 2002, 277(35), 31850-56). Schlitt et al. has reported that mice with deficiency of PLTP exhibit enhanced organism anti-inflammation capability (Schlitt A., Liu J., Yan D. et al. Biochim Biophys Acta. 2005, 1733(2-3), 187-91).
In summary, reducing blood plasma PLTP activity has anti-atherosclerosis effect, which at least has following three action mechanisms: the first one is to decrease the secretion of apolipoprotein B in liver so as to make the secretion level of VLDL reduced; the second one is to enhance the anti-oxidation action of LDL and mitigate the formation of atherosclerosis caused by oxidation of LDL; the third one is to enhance anti-inflammation capability of organism and mitigate the damage of atherosclerosis induced by inflammation. Therefore, PLTP inhibitor is target of novel pharmaceuticals for the prevention and treatment of atherosclerosis.
PLTP and CEPT are both members of fat conveying/lipopolysaccharide binding protein family. Researches have shown that both are not overlapped in physiological function, reduction of PLTP activity can decrease the secretion of VLDL, while reduction of CETP activity can elevate HDL cholesterol level, these two aspects are favorable for the prophylaxis and treatment of atherosclerosis. Consequently, Jiang et al. has advanced that PLTP and CETP dual inhibitor is a hopeful target for treating atherosclerosis (Jiang X. C., Tall A. R. PCT Int. Appl. WO 2002068450; Jiang X. C., Zhou H. W. Curr. Opin. Lipidol. 2006, 17, 302-308). N-{2-[2-(2,2-dimethyl-propanamido)-phenyldithio]-phenyl}-2,2-dimethyl-propanamide is the only one PLTP inhibitor that has been reported in literatures at present, and is PLTP and CETP dual inhibitor, the Ki values to inhibit both are 15 μM and 13 μM, respectively (WO 2002068450).
Researches have shown that PLTP selective inhibitor, PLTP and CETP dual inhibitor and CETP selective inhibitor can all be used for the treatment and/or prevention of various diseases associated with the increased plasma PLTP activity in a mammal (including human), such as atherosclerosis, peripheral vascular diseases, dyslipidemia, hyperlipemia, hypercholesterolemia, hypertriglyceridemia, familial hypercholesterolemia, cardiovascular diseases, angina pectoris, ischemia, heart ischemia, stroke, myocardial infarction, reperfusion injury, hypertension, diabetes with vascular complications, obesity or endotoxemia, etc.
Term "PLTP selective inhibitor" means a compound capable of inhibiting PLTP activity but having no inhibition action to CETP activity.
Term "PLTP and CETP dual inhibitor" means a compound capable of inhibiting both PLTP activity and CETP activity.
Term "CETP selective inhibitor" means a compound capable of inhibiting CETP activity but having no inhibition action to PLTP activity.

Trisubstituted thiazole compounds, preparations methods, pharmaceutical compositions and medicals uses thereof

Institute of Pharmacology and Toxicology Academy of Military Medical Sciences P.L.C. China


A low pressure catalytic distillation process for producing high purity ethyl tertiary butyl ether that contains less than 0.6 weight percent ethanol, and preferably less than 0.07 weight percent ethanol, has been developed. The high purity ethyl tertiary butyl ether is withdrawn directly from a catalytic distillation column. No downstream processing is necessary to remove excess ethanol from the ether product. A stream containing a significant amount of one or more inert azeotropic agents such as normal butane, isopentane, and isobutane is introduced along with the isobutylene and ethanol reactants into an etherification zone containing a catalytic distillation column. The catalytic distillation column is operated under low pressure conditions which result in the reaction of the ethanol with the isobutylene to form ethyl tertiary butyl ether. The inert azeotropic agent must be present at the inlet to the catalytic distillation column in an amount sufficient to azeotrope excess ethanol and cause the excess ethanol to distill into an overhead stream under the conditions of operation. The preferred azeotropic agent is isopentane. Excess ethanol forms an azeotrope with the azeotropic agent and is distilled with other hydrocarbons into an overhead stream. The ethyl tertiary butyl ether and no more than 0.6 weight percent ethanol are distilled into a bottoms stream and withdrawn directly from the catalytic distillation column.

Ethers have become an important gasoline blending component in order to increase the octane rating of the gasoline without exceeding regulatory Reid vapor pressure limits and to reduce carbon monoxide emissions. Processes involving catalytic distillation have been used to produce ethers by the reaction of an alcohol with an isoalkene, see U.S. Pat. No. 5,258,560; in particular, catalytic distillation has been used to produce ethyl tertiary butyl ether by the reaction of ethanol and isobutylene. For example, U.S. Pat. No. 5,248,836 discloses passing an isobutylene-containing stream and a stream containing ethanol and ethyl tertiary butyl ether through a straight pass reactor to selectively react ethanol and a portion of the isobutylene to form a first product stream which is sent to a catalytic distillation column. In the catalytic distillation zone the ethyl tertiary butyl ether is largely distilled from the ethanol and isobutylene that are then further reacted to form a second product stream. The distilled ethyl tertiary butyl ether is collected and the second product stream is recycled to the straight pass reactor. U.S. Pat. No. 5,368,691 discloses a configuration for catalytic distillation whereby reaction zones are alternated with, and clearly separated from, distillation zones without a continuous liquid mass between a reaction zone and an adjacent distillation zone.
However, because excess ethanol is usually used to drive the etherification of isobutylene to high conversion and the unreacted ethanol distills with the product ethyl tertiary butyl ether, it is difficult to obtain a catalytic distillation product ethyl tertiary butyl ether having low levels of ethanol. Removing the ethanol from the ethyl tertiary butyl ether product results in a product having a lower Reid vapor pressure which, in turn, makes the ether product more valuable. U.S. Pat. No. 5,158,652 discloses a process for separating ethyl tertiary butyl ether and ethanol using two distillation columns operating at different temperatures and pressures. U.S. Pat. No. 5,401,887 discloses a process where the reactants undergo etherification in a reactor and the reactor effluent is sent to a distillation column for separation. The distillation column bottoms containing both ethanol and ethyl tertiary butyl ether is further processed to separate the ethanol from the ethyl tertiary butyl ether by adsorbing the ethanol on a selective adsorbent. U.S. Pat. No. 4,198,530 discloses a process for producing methanol-free methyl tertiary butyl ether. The methyl tertiary butyl ether is formed in an etherification reactor using a feed that contains methanol, C.sub.4 hydrocarbons, and a significant amount of normal butene. The reactor effluent is passed to a distillation zone where substantially all of the methanol in the effluent is azeotropically removed together with the C.sub.4 hydrocarbons and whereby substantially all of the methanol is removed from the methyl tertiary butyl ether. U.S. Pat. No. 4,413,150 discloses converting isobutylene and an alcohol to an ether in a reactor and then separating the product ether from the reaction mixture in a single distillation column where the product ether is substantially free of C.sub.4 hydrocarbons and alcohol.
Applicants, however, are the first to realize that in a low pressure catalytic distillation process, by routing a stream containing at least one inert azeotropic agent to an etherification zone at a point prior to the low pressure catalytic distillation column, excess ethanol will be drawn into an azeotrope with the inert azeotropic agent and will not be able to contaminate the ethyl tertiary butyl ether product. The result is a high purity ethyl tertiary butyl ether product containing no more than 0.6 weight percent ethanol available directly from the catalytic distillation column. No further downstream processing is needed for removal of ethanol and purification of the ethyl tertiary butyl ether.

Process for producing ethyl tertiary butyl ether by catalytic distillation


Disclosed is a method of operating an internal combustion engine simultaneously with ammonia and another fuel. The other fuel may be hydrogen, ethanol, propane, natural gas, liquefied petroleum gas, or the like. In a preferred embodiment, the other fuel is hydrogen and the engine has zero carbon emissions. A control system is programmable to adjust the proportion of ammonia and the other, catalyst fuel as selected by the operator.

The present invention relates generally to internal combustion engines and, more specifically, to internal combustion engines fueled with a catalyst fuel, such as hydrogen (H2), and ammonia (NH3) in any proportion to eliminate CO2 emissions.
Internal combustion engines have been run on hydrogen with electronic fuel injection. BMW and Ford Motor Company have demonstrated the technology in the automotive sector. Hydrogen Engine Company has shown the technology in the industrial sector. Ammonia was tested as a fuel by Rudolf Diesel, before he invented the diesel engine, and others with limited success. The use of electronic fuel injection for ammonia has not previously been demonstrated. Ammonia has a very slow flame velocity and a high ignition temperature making it hard to use as a fuel. Hydrogen has a high flame velocity and a low ignition temperature making it easy to ignite. Hydrogen is known to burn 8.3 times faster than gasoline. Specialized engine controls are required to run an internal combustion engine on either type of fuel and even more specialized to run both. Ammonia has a high hydrogen content (˜17%), is easily stored and widely distributed.
The world needs to reduce greenhouse gas emissions and dependence on fossil fuels. Hydrogen can meet both requirements, however hydrogen is not yet widely distributed and is very difficult to store. It is the difficulty and expense of storing hydrogen that is expected to limit its use. Ammonia is widely distributed as anhydrous ammonia (a fertilizer). It is also easily stored in vessels identical to propane tanks except with a different valve system. Ammonia is a more ideal fuel because it is not considered flammable, is widely distributed, and is easily stored. A technique for use of ammonia as a fuel in internal combustion engines is needed.

Hydrogen and ammonia fueled internal combustion engine


A universal fitment for use with polymer-coated roof membranes to cover areas on and around vertical protrusions in a roof, is disclosed. The universal fitment has a body with at preferably three sides, a tab, and a neck connecting a corner of the body to the tab. The body is preferably either substantially square or substantially triangular. A universal boot is also disclosed. The universal boot has a generally rectangular section with a split extending vertically in a side, and a fitment with a body having at least three sides, a tab, and a neck connecting a corner of the body to the tab. The tab of the fitment is preferably welded to the back of the rectangular section above the split.

The invention generally relates to roof-covering membranes, and more particularly relates to a universal, adjustable fitment for use with roof-covering membranes.
Polymer coated membranes are commonly used to cover essentially flat roofs. The membrane is custom designed for the particular roof on which it is to be used. The roof measurements are provided to the factory which creates a unitary membrane from separate pieces which have been heat welded together.
There are frequently items protruding from the surface of the roof, such as vents, ductwork, air conditioning units, and the like. The size and location of these items must also be provided to the factory so that accommodations can be made for them in the membrane.
Providing a water-tight seal around these protrusions presents a number of problems. U.S. Pat. Nos. 4,799,986 and 4,872,296 disclose a method and a fitment which have been used to cover the corners of protrusions. The corners comprise a first generally rectangular member segment, a side being part-way split interjacent its ends and a second member segment with a triangularly-shaped corner portion conformed to loop shape and having its marginal edges overlying portions of the first segment contiguous to the split and being welded thereto in a continuous weld seam. These known items work best when the corner is a right angle and the angle between the roof and the protrusion is a right angle.
However, in many cases the corner will not be a right angle, or the protrusion is not at a right angle to the roof, or there is some other irregularity in the protrusion, such as the bottom and the top being of different sizes. In these situations, known methods do not provide satisfactory results. The membrane must be folded or "bunched" in order to conform the membrane to the underlying structure. Not only is this folding and bunching unsightly, water can collect in the fold which can have deleterious effects on the roofing membrane and/or can lead to localized leaks at seams and at other places in the membrane. In addition, the folding can lead to cracking of the roof membrane over time, due in part to stresses induced by the fold lines.
Therefore, it is desirable to provide a universal fitment which provides a smooth transition no matter what the shape or angle of the underlying protrusion and which eliminates the need to fold the roof membrane.
The present invention provides a universal fitment that is useful with roof membranes to cover exposed roof areas around a vertical protrusion in a roof. The fitment is partially secured to the boot prior to installation of the boot on the roof membrane. Once the roof membrane is in place at the vertical protrusion, the floating portion of the fitment is finally secured to the roof membrane, substantially free of folds and bunching of material.


Disclosed herein is a shock absorber capable of controlling damping force characteristics. The shock absorber includes a cylinder filled with an operating fluid, a piston valve disposed inside the cylinder to divide an interior of the cylinder into a first chamber and a second chamber, a piston rod having one end extending outside the cylinder and the other end coupled to the piston valve inside the cylinder, a hollow chamber formed inside the piston rod to communicate with the first and second chambers, a free piston disposed within the hollow chamber to move up and down and to divide the hollow chamber into upper and lower chambers, and a variable part configured to control the damping force characteristics by adjusting a vertical displacement of the free piston.

1. Technical Field
The present invention relates to a shock absorber for damping vibration transmitted to a vehicle according to a road state and, more particularly, to a shock absorber for controlling damping force characteristics by means of a hollow chamber formed inside a piston rod.
2. Description of the Related Art
Generally, a vehicle is provided with a suspension system for enhancing driving comfort by buffering impact or vibration transmitted to an axle from a road during driving. One of the components constituting the suspension system is a shock absorber. The shock absorber is typically disposed between the axle and a vehicle body. The shock absorber includes a cylinder and a piston rod reciprocating inside the cylinder. The cylinder is filled with an operating fluid, such as gas or oil, such that the operating fluid is moved by a piston valve secured to one end of the piston rod to generate a damping force.
A conventional shock absorber has a restriction in that it exhibits constant damping force characteristics with respect to variation of a road state or a driving posture of the vehicle. In other words, as determined in a manufacturing stage, a low (smooth) damping force characteristic can improve driving comfort of the vehicle, but cannot maintain a stable posture thereof. Conversely, a high (rigid) damping force characteristic can maintain the stable posture of the vehicle, but entails deterioration of the driving comfort. As such, the conventional shock absorber is incapable of controlling damping force characteristics in response to variation of the road state or the posture of the vehicle.
Accordingly, in order to solve the problem of such a conventional shock absorber, a shock absorber capable of providing variable damping force characteristics according to a displacement of the piston rod has been developed.
FIG. 1 is a partial cross-sectional view of a conventional shock absorber capable of providing variable damping force characteristics. Referring to FIG. 1, the shock absorber 10 includes a piston rod 14 connected to a vehicle body, and a cylinder 12 secured to an axle connected to wheels. The piston rod 14 reciprocates within the cylinder 12.
The piston rod 14 includes a piston valve 16 disposed at a lower end of the piston rod 14 to divide a space of the cylinder 12 into a rebound chamber RC and a compression chamber CC. The piston valve 16 is formed with a rebound passage 16a and a compression passage 16b through which the rebound chamber RC and the compression chamber CC fluidly communicate with each other. The shock absorber 10 further includes discs 18a and 18b disposed on upper and lower sides of the rebound passage 16a and the compression passage 16b to resiliently deform and generate a damping force according to movement of an operating fluid.
The piston rod 14 has a hollow chamber 20 formed therein. The hollow chamber 20 is provided with a free piston 22 that can move up and down and divides the hollow chamber 20 into an upper chamber 20a and a lower chamber 20b. An upper portion of the upper chamber 20a is in fluid communication with the rebound chamber RC through a through-hole 24, and a lower portion of the lower chamber 20b is in fluid communication with the compression chamber CC through a shaft hole 25.
As the piston rod 14 is slightly displaced, the free piston 22 is lifted or lowered, and the operating fluid flows into or from the hollow chamber 20 through the through-hole 24 or the shaft hole 25. As a result, the damping force characteristics of the shock absorber 10 are varied.
Referring to FIG. 2, Curve X1 indicates variation of the damping force of a general shock absorber which cannot control the damping force characteristics, and Curve X2 indicates variation of the damping force of the conventional shock absorber 10 capable of providing a responsive damping force. As shown in this plot, the conventional shock absorber 10 provides the damping force as indicated by Curve X2 according to the volume of the hollow chamber 20, that is, a range of motion of the free piston 22.
However, since the conventional shock absorber adopts a mechanical structure for buffering the impact or vibration, it is not effective in controlling the damping force and has a limited performance of varying the damping force.

Shock absorber for controlling damping force characteristics


Issuing and managing digital certificates for students is described. A server can receive organization information regarding an educational institution, group information regarding a course, and certificate information regarding the types of content to be displayed upon a digital certificate indicating that a student has completed the course. The server can generate a digital certificate template indicating the types of content and layout of that content for generating digital certificates. The digital certificates can then be generated and published to webpages for students.

Organizations often provide certificates to students or employees upon completion of training. For example, a university can provide a diploma as a certificate to a student indicating that the student is a graduate in a particular program offered by the university. A language institute might provide a certificate to a student indicating that the student is proficient in speaking a particular language. A business might provide a certificate to an employee indicating that the employee has completed an internal training program.
These certificates are often printed on paper and can also be hand-signed, embossed, etc. and then packaged in an envelope and mailed. However, providing certificates to hundreds or thousands of students can be an expensive and time-consuming process.

This patent is subject to a terminal disclaimer.

Technique for generating digital certificates


The computation speed of a fast X+2X adder is improved by restructuring the carry generate/propagate logic. The adder is implemented with a multi-bit generation/propagation circuit which takes full advantage of the fact that in the X+2X computation, the input X is left-shifted by one bit and then added to itself. Significantly simplified multi-bit carry generate and propagate functions, and therefore fast circuits, are the result.

1. Field of the Invention
The present invention generally relates to digital data processing circuits, and more particularly to a binary X+2X adder using a multi-bit generate/propagate circuit.
2. Background Description
Binary multipliers are generally used in microprocessors, digital signal processors, micro controllers, and other digital integrated circuit (IC) products. For multipliers which use a multi-bit Booth algorithm, dedicated 3X computation circuits are needed for partial product generation, and the 3X partial product generator is almost always on the critical timing path. Conceptually, multiplying an input X by 3 can be accomplished by adding the input X and its 1-bit left-shifted value 2X using an adder as illustrated in the table of FIG. 1.
In FIG. 1, the addend (X) represents a multi-bit 00x.sub.52. . . x.sub.i. . . x.sub.3 x.sub.2 x.sub.1 x.sub.0 binary number X, where x.sub.0 is the least-significant-bit. The augend (2x) represents a 1-bit left-shifted version of addend, which has a binary value of 2X. As in any type of adder design, the speed of the adder is often limited by the time it takes to perform carry generation and propagation logic delay. Therefore, any simplification of the carry generation and propagation logic for X+2X adder would directly improve the speed of 3X computation, and hence the speed of any given multiplier.
FIG. 2 represents a prior art generate/propagate circuit design for a X+2X adder. The first level of the carry-look-ahead tree are 2-bit generate/propagate circuits based on following logic equations: EQU g2.sub.1 =a.sub.i b.sub.i +a.sub.i-1 b.sub.i-1 (EQ 1) EQU p2.sub.i =(a.sub.i +b.sub.i) (a.sub.i-1 +b.sub.i-1) (EQ 2)
Equation 1 is implemented by two AND gates 101 and 102 and an OR gate 103, and equation 2 is implemented by two OR gates 104 and 105 and an AND gate 106. The next pair of significant bits a.sub.i-2, b.sub.i-2 and a.sub.i-3, b.sub.i-3 are operated on by similar logic, and so on. At the second level of the tree, 4-bit generate/propagate signals are produced by merging two adjacent 2-bit generate/propagate signals in a conventional approach, with the logic equations given by: EQU g4.sub.i =g2.sub.i +p2.sub.i g2.sub.i-2 (EQ 3) EQU p4.sub.i =g2.sub.i +p2.sub.i p2.sub.i-2 (EQ 4)
Equation 3 is implemented by OR gate 107 and AND gate 108, and equation 4 is similarly implemented by OR gate 109 and AND gate 110. FIG. 3 is the truth table for the prior art 4-bit generate/propagate function implemented in the logic of FIG. 2.

X+2X adder with multi-bit generate/propagate circuit

International Business Machines Corporation


In a control system for a plant controlling a plant such as a nuclear power plant 1 with use of a plurality of digital control devices 41, the plurality of digital control devices 41 include a plurality of control functions 46 to 56, and the plurality of control functions 46 to 56 are provided in the plurality of digital control devices 41 in a distributed manner so that the digital control devices 41 may not fall below safety standards preset by safety analyses. This provides a control system for a plant using the plurality of digital control devices 41 and configured to control a plant safely even when a digital control device is failed.

Conventionally known is a distributed control system including a host control device, local control devices, and an integrated control device (for example, refer to Patent Literature 1). In this distributed control system, the host control device monitors and controls an overall plant, the local control devices control individual units in the plant, and the integrated control device integrates and controls the local control devices by function. The host control device includes a plant control means having an equal function to that of a plant control means of the integrated control device so as to perform plant control instead of the integrated control device at the time of occurrence of a failure of the integrated control device.


A wireless electronic device is disclosed that includes one or more ground planes and an antenna electrically coupled to the one or more ground planes. The antenna is positioned adjacent to a portion of the one or more ground planes. The wireless electronic device includes a material placed in a position and having a dielectric constant selected to increase an effective electrical size of the one or more ground planes relative to the effective electrical size of the one or more ground planes without the material. Other wireless electronic devices and methods for forming the same are also disclosed.

Mobile electronic devices, such as mobile phones and other mobile devices, are getting smaller. Mobile electronic devices use antennas to receive and transmit information, and the size of the antennas is related to the frequency band being used. For instance half-wavelength and quarter wavelength antennas are commonly used. Typical antennas used in mobile electronic devices include planar inverted F-antenna (PIFA), planar inverted L-antenna (PILA), inverted L-antenna (ILA), inverted F-antenna (IFA), and whip antennas. Many antennas in mobile electronic devices are placed above or in close vicinity to a printed wiring board (PWB) (also called a printed circuit board) and couple electromagnetically to the ground plane of the PWB. Such coupling can be both beneficial and detrimental. For instance, a quarter-wavelength antenna uses the ground plane of the PWB to increase the effective size of the antenna.
However, due to the shrinking nature of mobile phone design, radiation performance has become more troublesome to achieve. Especially at low frequencies, this is a growing problem, since the PWB acts like a dipole antenna and most of the radiation actually comes from the ground plane and not the antenna itself. The optimal length, for the low frequency bands, of the PWB is about 120-130 mm (millimeters), from a radiation performance point of view. This is however not acceptable from an industrial design point of view. For instance, 120 mm is about 4.7 inches, which is too long for many common mobile phones.
Therefore, it would be beneficial to provide techniques for improving radiation performance of antennas, to decrease the physical size of the antenna, or both.

Enhanced radiation performance antenna system


This invention provides a process meeting the EPA's PFRP standard for WWTS treatment thereby producing a readily usable end-product in either soil-like form or semi-impermeable low load bearing, mass form. The process includes mixing WWTS with lime and fly ash, to cause a temperature increase to above 70.degree. C. for at least 30 minutes and to cause the pH to exceed 12 for at least 2 hours. The end-product may be compacted to produce an semi-impermeable, durable mass or the soil-like product may be used as landfill cover material.

1. Field of the Invention
The invention is a method of stabilizing wastewater treatment sludge (WWTS) by treating it with quick lime and fly ash to produce a stabilized composition that meets the U.S. Environmental Protection Agency (EPA) process for further reduction of pathogens (PFRP) standard. This stabilized material can be utilized as sanitary landfill cover material. The invention provides an environmentally sound method of reclaiming fly ash and sludge and converting these waste products into a useful end product.
2. Description of the Related Art
An urban, industrialized society produces large quantities of waste. Some of this waste is in the form of waters containing waste such as organic-laden sewage waters treated at municipal, commercial and industrial water treatment works, these wastewaters contain a variety of organic and inorganic compositions that are often treated onsite. Depending upon the treatment process, slurries high in suspended solids may be formed. These slurries, commonly referred to as sludges, are produced either by the concentration of solids originally in the waste water (e.g. primary sludge) or the formation of new suspended solids which result from the removal of dissolved solids from the waste water (primary and tertiary sludge).
The term "wastewater treatment sludge (WWTS)" as used in the specification and claims includes sludges produced from the treatment of organic-laden sewage waters such as the sludges produced by municipal, industrial and commercial wastewater treatment facilities, and the like. Thus, WWTS includes sludges produced from sewage subjected to primary treatment, sludges from sewage subjected to secondary treatment, and sludges subjected to tertiary treatment.
In some cases these sludges are digested or otherwise stabilized at the wastewater treatment facilities. In other cases the sludges may not be stabilized prior to disposal. In either case, these sludges may be or may become odoriferous and may contain a broad variety of bacteria, parasites, viruses and other pathogenic organisms.
Sludges that contain elevated levels of heavy metals are precluded or seriously inhibited from land application. Since large volumes of non-hazardous sewage sludge are produced and beneficial reuse of a large proportion of this sludge is inhibited due to metals and pathogen content, odor problems and seasonal restrictions on land application or land availability, it would be desirable to develop methods for converting these sludges into an odorless, stabilized end-product that is needed year round.
Coincidentally, large quantities of fly ash from the combustion of coal, lignite or wood are generated in this country. Fly ash is utilized as an additive in concrete, as a soil stabilization material or as a soil additive; however, large volumes are disposed of in sanitary landfills or abandoned mining excavations. These disposal methods may lead to ground water contamination, or consume valuable disposal capacity within sanitary landfills. Therefore, it would be desirable to develop additional methods that provide long term environmentally sound methods of utilizing fly ash in a beneficial manner that minimizes the consumption of landfill space.
The U.S. Environmental Protection Agency (EPA) has recognized the problems which disposal of pathogen infested waste can present. In response to these problems, the EPA has issued guidelines at 40 C.F.R. .sctn.257 concerning land disposal of sewage sludge which contains pathogens. The EPA regulations recognize three separate categories of sludge: unstabilized sludge; sludge exposed to a process to significantly reduce pathogens (PSRP); and sludge exposed to a process to further reduce pathogens (PFRP).
"Unstabilized sludge" has not been exposed to any pathogen reducing process, is not suitable for general land application, and can only be incinerated or landfilled. Sludge which undergoes a PSRP, such as an anaerobic digestion, heat treatment, lime stabilization, or air drying, can be disposed of on land only if public access to the land is controlled for a period of from 12 to 18 months. Finally, sewage which has undergone a PFRP has no disease-related restrictions on reuse. Unfortunately, known PFRP methods are expensive, highly energy intensive processes, such as irradiation or thermal processing, which are unsuitable for transforming sewage sludge into a readily usable end product.
If a treated sludge is to be readily usable, it is desirable that it meet the EPA's PFRP standard so that it poses a minimal risk of transferring diseases to humans. Further, it must not attract vectors and it must not be flammable. Also, if it is to be disposed of as landfill cover material, it must be readily spreadable with conventional equipment. In addition, it must also have a load bearing capability of at least one ton per square foot and have a permeability in the range 10.sup.-5 cm/sec to 10.sup.-6 cm/sec.
The early prior art recognizes the need to concentrate the waste contained in wastewaters for ease of treatment and disposal. For instance, U.S. Pat. No. 1,672,584 relates to the treatment of sewage with an alkaline composition, such as hydrated lime, to change the positively charged colloids, that make up the organic waste, into negatively charged colloids. These negatively charged colloids are then coagulated with an electrolyte, such as iron or aluminum sulfate. As an alternative, cement kiln dust could be used as the electrolytic coagulant. The high density of cement kiln dust is said to materially increase the settling rate of the precipitate formed.
U.S. Pat. No. 3,476,683 describes mixing sludge with lime. Heat is generated during this mixing due to the reaction of lime and water and the temperature increases to "more than 100.degree. C." The sludge powder obtained is said to be "sterilized" by the heat generated.
Both of the above patents recognize the need to use inexpensive reagents, both use lime. Since large volumes of sludge must typically be treated, it is economically desirable to use inexpensive, readily available reagents to treat or stabilize the sludge. It is even more desirable to combine other waste products with the sludge if one could thereby both stabilize the sludge for disposal and dispose of the other waste products simultaneously.
U.S. Pat. No. 4,306,978 relates to the use of lime for the treatment of sludge to produce stabilized sludge pellets. A dewatered cake containing 10-60 wt. % of dry solids is mixed with 2-40 wt. % of lime, based on the dry solids weight. During this process, the temperature increases to the range 95.degree.-100.degree. C. due to the chemical reaction between lime and water. Further, this high temperature coupled with the high pH caused by the lime, is said to destroy bacteria and pathogenic organisms in the sludge. This treated mixture is then mechanically pelletized.
U.S. Pat. No. 4,226,712 is also directed to the treatment of sludge with lime to obtain a partially dried mixture. This mixture is then subjected to a second step of drying and granulation to produce a product suitable for use as fertilizer.
Similarly, U.S. Pat. No. 4,781,842 relates to a two-step process for treating sludge with lime, cement kiln dust, or lime kiln dust to raise the pH above 12 for at least about 2 hours and then drying the resulting mixture by an aeration process to produce a granular product. This process is said to meet USEPA PFRP standards and its product may be used as a fertilizer. U.S. Pat. No. 4,554,002 uses a similar process and suggests that fly ash may be substituted for cement kiln dust.
U.S. Pat. No. 4,793,927 is directed to a method of encapsulating sewage in an "impervious mass" with an "ammonia source" so that the ammonia released within the mass will destroy helminths, an organism that is difficult to destroy by other methods. The end product is a friable, clay-like material. The process meets EPA PFRP standards and the product is suitable for use as landfill cover, land reclamation material, fertilizer, etc. The method includes mixing the sewage with a setting agent and silicate in the volume ratio about 10:1:0.5. Suitable setting agents include Portland cement, lime and kiln dust. The silicate used is sodium silicate.
Fly ash is solid waste material that is readily available and that would be attractive to use as a reagent to treat and stabilize WWTS. Fly ash is produced as a residue of the combustion of coal, lignite, or wood and is an artificial pozzolan.
Early efforts to dispose of fly ash included combining dry fly ash and hydrated lime to produce a hydrated lime cement. U.S. Pat. No. 2,564,690 describes how to make such a cement and mix it with an aggregate and water to produce a composition capable of setting up to a high strength. U.S. Pat. No. 3,852,084 addresses the slow hardening of lime-fly ash cements and teaches milling of the lime and fly ash to increase their reactivity and increase the rate of hardening.
U.S. Pat. No. Re. 30,943 and U.S. Pat. No. 4,101,332 describe the use of a mixture of fly ash and cement kiln dust together with an aggregate, such as limestone, sand, blast furnace slag, gravel and the like, as a road stabilizer base. Thus, the mixture sets up to a hardened, load-bearing mass. Similarly, U.S. Pat. No. 4,038,095 is directed to a load bearing composition that includes fly ash, lime stack dust and an aggregate.
U.S. Pat. No. 4,432,800 is directed to a method of producing a hardened durable mass using beneficiated kiln dust which typically has low reactivity. The reactivity of the kiln dust is increased by the addition of lime, calcium hydroxide, or sodium hydroxide. The beneficiated dust can be used in conjunction with fly ash and an aggregate to produce a hardened durable mass.
The related art shows methods for concentrating sludges and methods for stabilizing sludges. Some of these methods do not meet the PFRP standard, indeed, only the methods of U.S. Pat. Nos. 4,793,927; 4,781,842 and 4,554,002 are said to meet this standard. Methods of these patents produce a friable, clay-like product.
U.S. Pat. No. 4,028,130 discloses a method of using digested sewage sludge producing a "hardenable composition" suitable for disposal in landfills. This method entails mixing the sewage sludge with hydrated lime and fly ash in the proportions (based on wt. % solids) 5-50% water, 1-15% hydrated lime, 1-50% sludge solids, 20-90% fly ash, 0-60% soil and 0-10% calcium sulfate. The patent does not mention the EPA's PFRP standard or that its hardenable composition meets this standard.
What is yet needed is a method of stabilizing WWTS to meet PFRP standards that utilizes readily available and inexpensive reagents to produce a solid material, either friable and clay-like, or a solid mass capable of supporting at least a low load, depending upon the quantity of reagents used, and that can be utilized safely and effectively as landfill cover.

Lime and fly ash stabilization of wastewater treatment sludge


A fixture carrier including two uprights spaced apart and secured using cross bars that permit the center-to-center distance between the uprights to be adjusted. In conjunction with this horizontal adjustment, vertically adjustable support members mounted upon each upright provides a factory-assembled fixture carrier that may be easily adjusted in the field to accommodate horizontal distances between the uprights and vertical positions of the support members. Supporting arms for carrying the fixture are secured to each support member.

1. Field of the Invention
This invention is directed to a fixture carrier for supporting plumbing fixtures, wherein the carrier has a frame with supporting arms and wherein the supporting arms are both vertically and horizontally adjustable.
2. Description of Related Art
Fixture carriers are utilized to act as supports for plumbing fixtures such as service sinks, lavatories (sinks), urinals and water coolers. The fixture carriers are mounted upon a floor behind a wall and arms extend from the carrier through apertures in the wall to support a fixture with as little of the carrier visible as possible. In the past, fixture carriers were delivered to a work site in parts such that each fixture carrier had to be assembled on site. Not only did this turn out to be time consuming and expensive but, furthermore, it was possible that, with the congestion of a typical work site, parts of the unassembled fixture carrier could be misplaced or lost thereby further delaying assembly of the carrier.
U.S. Pat. No. 6,360,381 is directed to a universal fixture support comprised of a rigid rectangular frame having two upright spaced-apart posts connected by two cross bars that are permanently attached to the ends of the posts. Supporting arms extend from brackets which are vertically adjustable upon each upright. However, in the arrangement disclosed in the '381 patent, the center-to-center distance between brackets secured upon each upright is fixed and, as a result, this fixture support may be utilized only for fixtures that are compatible with the fixed center-to-center distance of the brackets for this particular fixture support.
A fixture support manufactured by J. R. Smith Manufacturing Company identified as their Labor Saver™ fixture support is similar in design to the fixture support illustrated in the '381 patent with the exception that the brackets from which the supporting arms extend are slotted with bolts extending therethrough such that the brackets may be laterally moved to adjust the center-to-center distance between the brackets for accommodating fixtures having different center-to-center dimensions. However, this lateral motion forces the location of each bracket to be offset relative to the centerline of each upright and this produces an undesirable bending moment upon the bolts securing the brackets and whole system, as opposed to a bracket wherein the supporting arms are aligned with the centerline of the uprights.
Additionally, the brackets of the Labor Saver fixture support are simultaneously adjustable in the vertical direction and in the lateral direction. As a result, precise positioning of each bracket may be difficult since it is not possible to secure the bracket, for example, in a vertical position and then subsequently secure the bracket in a lateral position.
A fixture carrier is needed that is factory assembled, but when installed in the field, provides maximum flexibility in assembly and provides a high level of strength in each supporting arm.


This invention enables authenticated communications (transactions) to take place on a standard I2C bus without requiring modification of existing I2C devices. Read and write transactions occurring on the bus are authenticated using an Authentication Agent and a shared secret key. In addition to allowing verification of the legitimacy of the transactions, the authentication of the I2C transactions enhances the reliability and serviceability of the bus and devices on the bus by allowing the Baseboard Management Controller (BMC) to quickly determine and pinpoint errors.

1. Field of the Invention
This invention relates generally to the field of communications occurring on an I2C bus.
2. Background of the Related Art
An inter-IC bus, commonly called an IIC or I2C bus, is a control bus that provides a communication link between integrated circuits in a system. Currently there is no standard way to secure an I2C communications channel and thus, like all unsecured systems, systems employing I2C communications are vulnerable to attack and tampering. As an example, a somewhat sophisticated attacker could surreptitiously open up a machine employing an I2C bus, such as a server, and install a commonly-available I2C writer tool on the I2C bus. The I2C writer tool allows the traffic on the bus to be monitored, or "snooped" as such monitoring is often called in the computer security field. This would allow the attacker to determine how the resources on the bus are being enabled or disabled. Armed with this information, legitimate transactions occurring on the I2C bus could be replicated (and thus appear as legitimate transactions themselves) by the attacker.
One reason that an I2C bus can be attacked so easily is that it is a well-defined open bus and multiple masters can legitimately reside on the bus and co-exist peacefully. In a multiple-master environment of the prior art, each master will be aware that transactions initiated by others are taking place on the bus, but they are unable to determine if these other transactions are legitimate transactions or "rogue" transactions initiated by an intruder. In a single-master environment, the master could be programmed to detect any other transactions occurring (i.e., transactions not initiated by the single master) and operate on the assumption that such transactions are rogue, however, a sophisticated attacker could modify a transaction initiated by the master and such modifications could go undetected. Thus, an attacker can essentially communicate on the I2C bus transparently. This allows rogue masters to enter the bus, communicate with devices on the bus, and change and/or read data that are on those devices without the overall system knowing that those events have happened.
Accordingly, it would be desirable to have the capability to authenticate communications occurring on an I2C bus to assure that the communications are legitimate.

International Business Machines Corporation


A programming method efficiently programs programmable logic devices of the type having specialized multiplier blocks that include multipliers and other arithmetic function elements. Such blocks can be used to perform certain multiplication and multiplication-related functions more efficiently than general-purpose programmable logic. In order to efficiently program devices having such specialized multiplier blocks, so that they are used to their full potential and so that the maximum number of multiplier-related functions can be accommodated on a single programmable logic device, the programming method pre-processes the netlist of function blocks in a user's programmable logic design, grouping multiplication and multiplication-related functions efficiently. The method takes into account limitations imposed by the structure of the specialized multiplier blocks, in addition to location constraints imposed by the user and location constraints dictated by the need for certain functions be carried out near where certain other functions are carried out.

This invention relates to programmable logic devices having blocks that perform multiplication and other arithmetic functions. More particularly, this invention relates to a method for programming such programmable logic devices while taking into account constraints imposed by those blocks or by users.
Programmable logic devices are well known. Early programmable logic devices were one-time configurable. For example, configuration may have been achieved by "blowing"—i.e., opening—fusible links. Alternatively, the configuration may have been stored in a programmable read-only memory. Those devices generally provided the user with the ability to configure the devices for "sum-of-products" (or "P-TERM") logic operations. Later, such programmable logic devices incorporating erasable programmable read-only memory (EPROM) for configuration became available, allowing the devices to be reconfigured.
Still later, programmable logic devices incorporating static random access memory (SRAM) elements for configuration became available. These devices, which also can be reconfigured, store their configuration in a nonvolatile memory such as an EPROM, from which the configuration is loaded into the SRAM elements when the device is powered up. These devices generally provide the user with the ability to configure the devices for look-up-table-type logic operations. At some point, such devices began to be provided with embedded blocks of random access memory that could be configured by the user to act as random access memory, read-only memory, or logic (such as P-TERM logic).
As programmable logic devices have become larger, it has become more common to add dedicated multiplier circuits on the programmable logic devices. Whereas in prior programmable logic devices space was not available for dedicated multipliers, current larger devices can accommodate multipliers. This spares users from having to create multipliers by configuring the available logic. Moreover, as described in copending, commonly-assigned U.S. patent application Ser. No. 09/955,645, filed Sep. 18, 2001, specialized multiplier blocks may be provided including multipliers and other arithmetic circuits such as adders and/or subtracters and/or accumulators. Such blocks are sometimes referred to as "multiplier-accumulator blocks" or "MAC blocks." Such blocks, for example, may be useful in digital signal processing, such as is performed in audio applications, and therefore such specialized multiplier blocks also are sometimes referred to as "DSP blocks."
While it may have been possible to program the earliest programmable logic devices manually, simply by determining mentally where various elements should be laid out, it was common even in connection with such earlier devices to provide programming software that allowed a user to lay out logic as desired and then translate that logic into programming for the programmable logic device. With current larger devices, it would be impractical to attempt to lay out the logic without such software.
The aforementioned specialized multiplier blocks present issues that had not existed in prior generations of programmable logic devices. In particular, because such blocks are large and complex, the number of such blocks on any one device may be relatively small, and they are placed in specific locations. Therefore, any programming software or method used with such devices must be able to implement a user logic design that incorporates the specialized multiplier blocks, including obeying the constraints imposed by those blocks or by the user, as well as by the relative location of those blocks to other logic regions with which they must interact.

Method for programming programmable logic device with blocks that perform multiplication and other arithmetic functions


A method for tracking multiple classes of records in a single blockchain is disclosed, the method comprising: by the administrative node computer, receiving, from a first node computer, a request for a class identifier for a certain class, the request including an address identifier associated with the first node computer; generating the class identifier; creating an association between the class identifier and the address identifier; receiving a data element from the first node computer, the data element including the address identifier, the class identifier, and record update information; verifying that the class identifier is associated with the address identifier; verifying that the record update information is permitted according to the class identifier; and creating, a block for a blockchain, the block including the data element. Class identifiers can used for each record entry to distinguish between classes within the blockchain.

New technologies are improving systems for record keeping. For example, blockchain technology provides self-referencing and cryptographically secure records that are safe from tampering. However, it can be cumbersome to create and implement secure record keeping systems, such as blockchains. As a result, blockchain systems are often not created unless there is the high chance of the data tampering or the record-keeper has abundant disposable resources. Accordingly, many types of records remain insecure.
Embodiments of the invention address these and other problems individually and collectively.

Systems and methods for creating a universal record


Provided is an ink type image recording apparatus capable of recording high gradation monotone images of high quality at low cost by establishing a certain relationship between a lightness order in a color ink set, which is employed when the image recording apparatus is used as a color image recording apparatus, and a density order in a monotone ink set, which is employed when the image recording apparatus is used as a monochrome image recording apparatus, a control apparatus thereof, and a recording apparatus.

1. Field of the Invention
The present invention relates to an image recording apparatus and method of controlling the same, and to a recording apparatus.
2. Related Background Art
In recent years, it is desired to provide printer outputs of photographic quality due to the spread of digital cameras, so measures are being taken to ensure that pixels are not conspicuous during color printing, such as using low-density color inks. Consequently, printers capable of printing color images of photographic high quality are widely used.
However, monotone images are still commonly used in fields such as the medical field in which X-ray photographs, CT and MRI images, and the like are used, and in the field of artistic photography.
This is because the human eye has the capacity for high density resolution, and therefore the amount of information capable of being recognized by the human eye is greater in monotone images than in color images.
In addition, it is known that the density resolution capability of the human eye becomes higher when using a transparent recording medium than when using a reflective recording medium. It is said that, in general, although the human eye density resolution with respect to color images is on the order of 8 bits, it is between 10 and 11 bits for monotone transparent images.
Medical images are provided by recording X-ray photographs, and CT and MRI images, on transparent recording media. Diagnosis can be made by a doctor looking at the image at the limit of the density resolution capability of the human eye.
However, recording devices that specialize in high gradation monotone images used mainly in the medical field are extremely expensive.
Photographic quality color image recording apparatuses which are relatively low in cost and capable of recording monotone images also exist, but have a disadvantage in that their gradation expression is inferior compared to that of recording devices that specialize in monotone images.
An example of this type of recording device is one that uses a sublimation thermal transfer method. This is a method in which three types of ink ribbons (dyes) in the colors Y, M, and C, or the colors R, G, and B, are prepared, and in a state where the ink ribbons overlap with a recording medium, partial heating thereof is conducted by using a thermal head. Then, the dyes in the ink ribbons are transferred to the medium, thus forming an image. A color image can be formed by repeating the same process three times for the three types of ink ribbons. The three types of ink may all be overlapped uniformly in order to record monotone images with this method.
However, since the monotone images are expressed by overlapping the three types of colors with this method, it is difficult to express neutral monochrome images having no color tints. Further, image with sufficient monochrome density (for example, OD3) cannot be expressed particularly on a transparent medium.
Another method is an ink jet method. In this case, three types of ink, in the colors Y, M, and C, or the colors R, G, and B, are prepared, and a color image can be expressed by overlapping the three colors. In this case as well, monotone images can be expressed by uniformly overlapping the three colors. However, with this method too, it is difficult to express neutral monotone images without color tints, similar to the sublimation thermal image transfer method, because the three colors are overlapped. Further, the inks must be overlapped in the same pixels in order to express sufficient monochrome density (for example, OD3) particularly on a transparent medium. However, there is a limit to the amount of ink that can be absorbed by the medium, and image with a sufficient monotone density cannot be expressed. That is, the inks are applied to identical pixels and overlapped in order to generate gradations in an image or in order to increase the density, but there is a limit to the amount of ink that can be absorbed by the recording medium. If the inks are overlapped to such an extent that this limit is exceeded, then the inks will overflow and the image will become blurry.
It is difficult to express monotone images with both of the methods described above because color inks are used, resulting in development of a slight color tint.
In addition, low density portions develop a rough image quality in which dither is noticeable.


A lens unit, for a projector, includes a scrambler which converts light input from a lamp into a uniform light. An image lens unit is arranged on an optical path between the scrambler and a liquid crystal display (LCD) panel for generating an image. The image lens unit allows the light passing through the scrambler to be emitted to the entire surface of the LCD panel. A collimating lens is arranged on the optical path between the image lens and the LCD panel and is provided for converting the light passing through the image lens into a parallel beam. The image lens unit consists of a first image lens of a positive power and a second image lens of a positive power.

The present invention relates to a lens unit for a projector and, more particularly, to a lens unit for a projector having two image lenses between a lamp and a liquid crystal display (LCD) panel.
FIG. 1 is a view schematically showing the optical arrangement of a conventional projector in which four image lenses are provided to represent a color image with one LCD panel. As shown in the drawing, while passing through an aperture member 12, the light emitted from a lamp 10 and reflected by a parabolic mirror 11 becomes a rectangular light having a ratio corresponding in length and width to a screen (not shown). The light becomes a uniform light as it passes through a scrambler 13, and then is inputted to an image generating means after passing an image lens 14, a hot mirror 15 for allowing infrared light to pass and a collimating lens 16 for converting the input light into a parallel beam. The image generating means includes polarizing plates 17 and an LCD panel 18 disposed between the polarizing plates 17 for generating an image as the input parallel beam passes through the rear side thereof. The image generated from the image generating means passes a condensing lens 19 and a projecting lens unit 20 comprising a mirror 21 and a plurality of lenses 22 for determining the degree of focus and magnification ratio of the image. Thereafter, the light is reflected off of a total reflection mirror 23 arranged at a predetermined angle behind the screen inside a cabinet (not shown), and thus magnified and projected to the screen.
The image lens 14 and the collimating lens 16 are optical members for uniformly distributing the uniform light passing through the scrambler 13 to the entire surface of the LCD panel 18. The image lens 14 magnifies the light passing through the scrambler 13 to a size of the LCD panel 18 and the collimating lens 16 converts the magnified light into a parallel beam. For such functions, the image lens employed in a conventional projector is comprised of four lenses. In such a case, however, the arrangement of optical elements is restricted and product costs becomes high due to the numerous number of parts.


The present technology provides compositions and methods for treating chronic kidney disease, end-stage renal disease, or diabetic nephropathy. The compositions comprise a nitrated lipid and an inhibitor of the renin-angiotensin-aldosterone system. The methods comprise administering a nitrated lipid in combination with an inhibitor of the renin-angiotensin-aldosterone system to a subject in need thereof, in an amount effective to treat diabetic nephropathy, chronic kidney disease, and/or end-stage renal disease. The use of a nitrated lipid with an inhibitor of the renin-angiotensin-aldosterone system exhibits a synergistic effect in treating chronic kidney disease and diabetic nephropathy.

Diabetes and diabetic complications represent a major public health problem, affecting 25 million Americans. In particular, diabetes and diabetic nephropathy constitute a major cause of CKD which progressively develops to end-stage renal disease (ESRD); patients with ESRD typically require dialysis or a kidney transplant. Currently, PPARγ agonists, thiazolidinediones (TZDs), are effective antidiabetic agents but are associated with severe edema, body weight gain and cardiovascular events. Inhibitors of the renin-angiotensin-aldosterone system (RAAS), which are widely used as anti-hypertensive agents, can help alleviate high blood pressure accompanying CKD but fail to stop the progression of CKD to ERSD. Indeed, in some instances, combination treatment with both an ACE inhibitor and an angiotensin receptor inhibitor has been shown to worsen major renal outcomes such as increasing serum creatinine and causing a greater decline in estimated glomerular filtration rate. Yusuf, S., et al., New England J. Med. (2008) 358 (15):1547-59.

Combination therapy with nitrated lipids and inhibitors of the renin-angiotensin-aldosterone system

The University of Utah Research Foundation


An amplifier includes a ground, first and second MOS transistors, a first resistive load and a supply voltage, which are connected in series in this order. A bias circuit provides first and second bias voltages to the gate electrodes of the first and second transistors, respectively. The bias circuit includes a third MOS transistor having its gate and drain electrode diode-connected. The drain electrode of the third transistor provides the first bias voltage of the amplifier. The bias circuit further includes fourth and fifth MOS transistors, and a second resistive load, which are connected in series in this order. The second resistive load is connected to the supply voltage. The fourth transistor has its gate electrode connected to the drain electrode of the third transistor. The fifth transistor has its gate and drain electrodes diode-connected. The drain electrode of the fifth transistor provides the second bias voltage.

1. Field of the Invention
The present invention relates to a bias circuit for providing a bias voltage to a high-frequency amplifier. More specifically, the present invention relates to a bias circuit applicable to, for example, a so-called UWB (ultra wide band) amplifier, which requires operation in a wideband of 500 MHz or more.
2. Description of the Background Art
A conventional example of the high-frequency amplifier for use in a narrow band is disclosed in, for example, Thomas H. Lee, "The Design of CMOS Radio-Frequency Integrated Circuits," Cambridge University Press, Cambridge, pp. 164-166 and pp. 288-292, 1998. This reference shows, on pages 164-166, an example of a cascode type amplifier for improving high frequency characteristics, and, on pages 288-292, an example of an amplifier with exemplified device constants.
A conventional example of the high-frequency amplifier for use in a wide band is taught by, for example, Paul R. Gray, et al., "Analysis and Design of Analog Integrated Circuits," Baifukan, Japan, pp. 286-289, Oct. 20, 2000. The quality factor, which is an indicator for indicating the frequency selectivity of the high-frequency amplifier, is disclosed in, for example, Masamitsu Kawakami, "General Network Analysis I; Linear Constant (1)", Corona Publishing Co., Ltd., Japan, pp. 72-77, 1979.
The above-indicated amplifiers present, however, the following problems. The circuit disclosed by Thomas H. Lee is apparently for a narrowband operation. It is thus difficult for the circuit to provide a wide bandwidth operation of 500 MHz or more required by the UWB amplifiers. Providing the wideband operation needs the circuit taught by Paul R. Gray, et al. The circuit cannot perform, however, a stable amplification operation at a reduced supply voltage. More specifically, it is difficult for the conventional circuits to provide both of the amplification operation with a sufficiently high gain in the wideband and the amplification operation at a lower supply voltage.

Bias circuit for a wideband amplifier driven with low voltage


An electronic representation of the range of color combinations that can be displayed on the monitor is created and printed. The printed representation is then scanned by the scanner. A relationship is then identified between the monitor and the scanner. This relationship is then used as the basis to determine a relationship between the scanner and the monitor. Compensation is made for errors and the relationship is further developed. Finally, a scanner RGB to printer CMYK lookup table is built.

1. Field of the Invention
The invention relates to color printing, and more specifically, to converting an input file defined in terms of a three dimensional color space to a color space that is consistent with a printer's capability.
2. Related Art
A color image is displayed on a monitor in terms of Red, Green and Blue (RGB). A color image is scanned in terms of RGB. The color image is printed on a printer using Cyan, Magenta, Yellow and Black (CMYK) inks.
For additive color processes, such as those used in display monitors, red, green, and blue are primary colors. In theory, mixing red, green, and blue light in various combinations can produce any color. For example, cyan is a mixture of green and blue and magenta is a mixture of red and blue. Black is the absence of any red, green, or blue; while white contains all three. A display monitor involves an additive process of light, and therefore, any color it produces can be defined in terms of Red (R), Green (G) and Blue (B).
In a printing process, inks are typically deposited on white paper which already reflects the full amount of red, green, and blue. Instead of adding red, green and blue (RGB) together to produce any color, quantities of red, green, and blue are removed to produce a desired color. To do this, filters or inks have to be produced which filter individual primary colors, while not affecting the other two. The filter colors which accomplish this are the colors which are the complement of the primary colors. For example, yellow is the complement of blue. A blue filter, one which filters out blue light, passes red and green and thus appears yellow. Yellow ink can be thought of as an ink which removes blue. Thus, the complement of blue is yellow; the complement of red is cyan; and the complement of green is magenta. As such, cyan, magenta, and yellow are the primary colors in the subtractive color system and are known as the process colors in the printing industry.
Theoretically, with only three colors of ink: cyan (C), magenta(M) and yellow (Y), a printer could print any color. White can be obtained by putting no ink on the paper; and black can be obtained by putting cyan, magenta, and yellow on the paper, blocking all light. Realistically, however, the color obtained when placing cyan, magenta, and yellow on paper may not be pure black. It may be brownish. Consequently, black ink is typically added to the printing process color set. The black ink not only insures a richer black color, but it also reduces the amount of ink that has to be used to produce most colors. For example, if at any one place on the paper, quantities of C, M, and Y are placed, there will be a gray component which can be removed and replaced with black. This reduces the total amount of ink on the paper and produces better grays and blacks. In addition, it increases the gamut of the color set.
As shown above, color can be expressed in several ways. A color can be expressed in terms of percents of RGB (red, green, blue), CMY, (cyan, magenta, yellow) or CMYK (cyan, magenta, yellow, black). None of these color spaces, as they are called, are defined as to what color is produced by mixing combinations of each. Generally, these color spaces are referred to as being device dependent, since the color produced by a given CMYK mix on one printer will not produce the same color on another.
An attempt has been made in the United States to standardize the process color inks so that the colors can be predicted. A standard called SWOP (Specification for Web Offset Publication) has been published which standardized the process ink colors. Recently, the standard has been taken a step further and 928 combinations of CMYK have been defined as to what color will result in a device independent color space (CIE XYZ or CIE L*a*b*). In Europe, a standard called Euroscale has been developed for four different paper surfaces. SWOP and Euroscale are very close, but not exactly the same.
In 1931, the organization called the Commission Internationale L'Eclairge (International Commission of Lighting), the CIE, met to try to establish a system of device independent color, color based on human sight. While attempting to define RGB, problems arose which persuaded the members to process the data through a matrix transform which produced a color space called CIE XYZ or XYZ. Since the XYZ color space is based on the human perception of color, any two different colors, even though the spectrum of these two colors may be different, will be perceived as the same color by a human if the XYZ values are the same under given lighting conditions.
From the XYZ color space, additional color spaces have been derived. One of these is called CIE L*a*b*, pronounced C Lab, or L*a*b*. This color space is based on XYZ of the color referenced to XYZ of the light source or paper. Most specifications such as the SWOP standard are specified in terms of XYZ and L*a*b* under a light source such as daylight D50. It is a three component color space with each color specified in terms of L*, a*, and b*. L* specifies the lightness; and the hue and saturation are determined from the values of a* and b*.
As previously discussed, a display monitor involves an additive process of light, and therefore, any color it produces can be defined in terms of RGB. However, a printing process is a subtractive process since it is printing on white paper, and therefore, color printers use cyan (C), magenta (M), and yellow (Y) or cyan, magenta, yellow and black (K), i.e., CMY or CMYK, to produce various colors. There has been an emphasis placed on the ability to accurately display an image on a monitor as well as the ability to accurately print an image on a printer. The internet and electronic mail have provided a level of interconnectivity that has driven the necessity of device independent color spaces. Uniform monitor display and uniform printer output ensure that individuals using different machines are seeing the same image. As a result of much research and development, most computer systems in the home and office now have the ability to incorporate these device independent color spaces into the monitor and the printer. The software controlling the printer relates the RGB values displayed to the CMYK values printed in accordance with the standardized colors.
Scanner technology continues to improve and become more affordable. As a result, all-in-one (AIO) devices (a combination printer, scanner and facsimile machine) have been increasingly used in homes and offices. Stand alone scanners can also be easily added to existing systems. The input to the printer may come from a personal computer (PC) or the scanner. A scanner measures the RGB of an image. In the copy mode (scanned image subsequently printed by printer), a multi-step process is required. First, the image is scanned in terms of RGB. Next, these RGB values are converted into device independent color values (i.e. CIE L*a*b). Several United States Patents utilize this device independent approach. Finally, the corresponding CMYK values are computed and printed. This is very similar to the monitor/display process and requires resource allocation sufficient to handle the process. U.S. Pat. No. 4,500,919 discloses a method of color reproduction on a monitor display. The device independent color space calculations allow the scanner to be used with different printers in different systems. U.S. Pat. Nos. 6,137,594; 6,072,901; 6,297,826 and 5,483,360 all utilize device independent color spaces to calibrate the printer.
In the case of an AIO device or a standalone scanner not intended to be removed from the printer, the above method is unnecessary. The device independent color space calculations duplicate the process already provided for in the relationship between the monitor and the printer to provide standardized colors. Resources must be allocated to create the scanner to printer relationship in the form of software running on the CPU or imbedded in firmware associated with the scanner. U.S. Pat. No. 5,339,176 discloses a method of color calibration that is device dependent. The '176 patent discloses a method of calibrating a scanner by directly creating a lookup table between a scanner point and a printer point. The calibration then changes the manner in which the scanner functions (column 16, lines 52–55). As a result, a new value will be assigned to a previous point. For example prior to calibration, a point may have a red value of 10 measured by the scanner. After the calibration the same point may have a red value of 11 measured by the scanner. This method requires the scanner program to be changed. The present invention achieves the same result without changing the function of the scanner.

Method of calibrating a scanner to a printer