The invention concerns an X-ray tomograph device.. This device makes it possible to obtain the image (1) of a plane cutting (2) of an object (3). In particular, it comprises an X-ray source (4) which supplies high energy pulses which traverse the object. At least one measurement detector small bar (10) receives the attenuated energy pulses which have traversed the object. A display and processing means connected to the detectors supplies the image of the cutting. These processing means include amplifier-integrator circuits (13) connected to the detectors (10) and to a computer (15) controlling the integration period of the detection pulses suplied by the detectors (10). The computer corrects the value of the amplitude of each detection pulse by talking account of an intermediate integration value so as to take account of the drag of each pulse and the stray current of each detector.

In particular, this invention is applicable to the industrial control of highly absorbant objects with large dimensions and for which it is desired to restore the images of plane cuttings by using a high-energy (for example, greater than several 100 KeV) pulsed X-ray source and means for processing the signals derived from radiation detectors having traversed this object. This invention may also be applied to the control of slightly absorbent objects with small dimensions.
There exists a known type of X-ray tomography device which makes it possible to obtain the image of at least one plane cutting of an object and includes an X-ray source supplying high-energy pulses at a predetermined frequency. This device also includes a primary collimator so that the pulses traverse the object inside a cutting plane and close to the latter. Means are usually provided to support the object and to move it in translation and/or in rotation. This type of device also includes a small bar of measuring detectors receiving the attenuated energy pulses having traversed the object and a secondary collimator placed between the object and the bar of detectors. These detectors respectively supply on outputs electric detection pulses representing the received attenuated energy pulses derived from the object. Finally, this known type of device includes display and processing means connected to the outputs of the detectors in order to supply the image of each cutting of the object. The signals derived from the detectors are generally coded and digitalized so as to enable them to be processed by a computer. In this type of device, the detectors may be constituted by photoelectron multipliers or photodiodes respectively connected to a scintillator.
In this known type of device, the pulsed X-ray source does not present perfect stability and the detection means may present temperature drifts and dark currents and, in the case of a radioactive object, there exists an unwanted detection not taken into account when processing signals. Accordingly, the image of each cutting obtained is not perfect.
When the detection means used are constituted by photoelectron multipliers or photodiodes connected to scintillators, these scintillators age under the effect of radiation thus, the transparency and efficiency of the scintillators become altered after absorbing a certain dose of X-rays. It is then necessary to regenerate the scintillators via a thermal cycle.
Owing to the foregoing, it frequently happens that any tomography device which uses scintillators is not available. Moreover, the volume occupied by a set of scintillators and photodetectors (photoelectron multipliers or photodiodes) limits the possibilities of embodying detection means with a small geometric pitch, which strictly limits the number of measuring points. Finally, the limited dynamics of photoelectron multipliers involves the use of photodiodes for objects with high absorption dynamics, but in this case necessary to take into account two energy conversion efficiencies: the efficiency relating to the conversion of X photons into visible photos and the efficiency relating to the conversion of visible photons into electrical charges. As a result, there is extremely high loss of sensitivity of the devices thus constituted allied with the introduction of significant statistical noise. In general, the scintillation efficiency is extremely low (less than 10% ).
Generally speaking, it is therefore preferable to use detection means which make it possible to carry out a direct conversion of the X photons into electrical charges. These detection means usually consist of small bars of detectors containing a semiconductor.
These detectors are used in a known way with low energy continuous radiation sources (normally with X-ray generators fed with a d.c. voltage of about several 10 k volts). These detectors are distributed in the form of a small bar (or a mosaic), each detector being constituted by a semiconductive pellet of small dimensions (about a few mm) inserted between two electrodes, the radiation to be detected arriving under normal incidence at the planes of the detectors and the electrodes.
This geometry of the detectors does not enable said detectors to be used with good efficiency for high energies. In fact, with such a structure, the increase of the thickness of the semiconductive pellet, rendered necessary so as to obtain high energy effectiveness, introduces a large collection distance of the charges created. This introduces two major drawbacks:
the charges can recombine before reaching an electrode,
the maximum charges collection time is considerable.
Owing to this, the known tomography devices functioning with high-energy X-ray sources do not use detectors containing a semiconductor.
In known pulsed source tomography devices, the signals supplied respectively by the detectors are pulse signals which present extremely high drag when the flow of X radiations received has extremely high energy. As a result, the pulse signal supplied by a detector after receiving an X-ray pulse having traversed the object may be superimposed on the pulse signal supplied by this detector at the time of receiving the X-ray pulse received previously. Moreover, these detectors, when being irradiated by the pulses originating from the object, present a relatively high temperature drift.
These known tomography devices functioning with high energy X-ray sources process the signals supplied by the detectors without taking account of the drag of the electrical pulse signal supplied by each detector, any temperature drifts provoked by the irradiation of these detectors and the dark current of each detector. These devices no longer take account of the instability of the X-ray pulsed source and any possible radiation emitted by the object itself (radioactive object). As a result, the image of each section of the object is an image of poor quality.


An infrared energy oxidizing and/or curing process includes an infrared oxidation zone having an infrared energy source operable to emit infrared energy that oxidizes a conductive thin film deposited or established on a glass substrate to establish a light transmissive or transparent conductive thin film for manufacturing of a touch panel. Optionally, the infrared energy curing process provides an in-line infrared energy curing process that oxidizes the conductive thin film on the glass substrate as the glass substrate is moved past the infrared energy source. Optionally, the infrared energy curing process bonds a thick film silver frit electrode pattern to the conductively coated glass substrate. Optionally, the infrared energy curing process reduces the transparent conductive thin film.

It is known that in interactive information devices such as touch panels and pen-input devices, there is usually at least one rigid glass substrate coated with a transparent conductive coating such as indium tin oxide (ITO) or doped tin oxide. Depending on the coating deposition process, the transparent conductive coating may need to be further oxidized to achieve optimum transparency and further reduced to achieve optimum electrical conductivity. This curing process requires elevated temperature in a forced dry air environment followed by the introduction of an inert atmosphere forming gas. It is also known that in interactive information devices such as touch panels and pen-input devices, there are usually thick film electrode patterns deposited on the conductive films. These thick film electrode patterns, typically silver fit compounds, also need to be thermally bonded to the conductive thin film and the glass substrate under the conductive thin film. This process, known as fit firing, also requires elevated temperatures. Prior practice for performing the required oxidation, reduction, and electrode bonding processes included processing in convection heat transfer batch style ovens. While batch oven processes are able to perform oxidation, reduction, and electrode firing within a single cycle, the cycle time required is excessive due to the inefficiency of convective heat transfer and the large thermal mass of the material batch. Temperature non-uniformity, as well as atmosphere distribution of the batch process can also cause variation in product performance. Continuous product flow ovens performing oxidation only and continuous product flow ovens performing reduction only are also common process options. These continuous flow ovens, also known as "lehrs", can utilize both convective and infra-red heat transfer mechanisms. This process option is also inefficient from a product through put perspective in that the product needs to be processed through two separate machines, requiring the heat up and cool down segments of the process to occur twice.

Infrared curing process for touch panel manufacturing


Compositions and methods useful for conferring passive or active immunity to the parasite, C. parvum. A high molecular weight glycoprotein antigen isolated from C. parvum, capable of binding the mAb 3E2, was shown to harbor an epitope critical for triggering the neutralizing CSP-like reaction in the parasite. Antibodies targeted against the critical epitope were shown to possess neutralizing activity, and could be combined with other anti-C. parvum monoclonal antibodies and administered to an animal to confer passive immunity. Immunogenic compositions including the purified antigen are disclosed for use in stimulating an active immune response against C. parvum.

The present invention relates to preparations useful for conferring passive or active immunity to the parasite, Cryptosporidium parvum. More specifically, the invention relates to a purified glycoprotein constituent of the parasite; use of the glycoprotein in an immunogenic composition; and monoclonal antibodies that bind a particular epitope disposed on the glycoprotein.
Cryptosporidium parvum is a coccidian parasite that causes intestinal disease in humans as well as economically important food animals including calves, lambs, and goat kids. Healthy, immunocompetent adult humans can be infected, but cryptosporidiosis is particularly serious when it occurs in immunodeficient individuals, including neonates, and those who are immunocompromised as a result of medical treatment, or because of other disease, such as infection by human immunodeficiency virus (HIV).
Among domestic animals, cryptosporidiosis is most frequently reported in calves. The ubiquity of C. parvum in dairy and beef operations throughout the U.S. and its importance as a cause of calf diarrhea are well documented. For example, Anderson et al. in Vet. Med. Sm. Anim. Clin. (June 1981) described well-managed, closed-herd dairies in which C. parvum-related morbidity in 1-2 week old calves approached 100%. We conservatively estimate that the combined treatment costs and decreased production losses incurred by the U.S. cattle industry due to cryptosporidiosis alone now exceed $50,000,000 each year.
C. parvum infection begins when sporozoites released from ingested oocysts invade intestinal epithelial cells. Following attachment of the anterior pole of sporozoites to intestinal epithelium, invasion is associated with host cell membrane evagination around the sporozoite and parasitophorous vacuole formation. Vacuole formation in the apical complex of invading sporozoites is thought to represent discharge of invasion mediators from apical organelles. Following invasion, a feeder organelle forms between the parasite and the host cell cytoplasm and increases the interface surface area markedly. This organelle may function in transport of materials between the host cell and developing trophozoite. Two stages of merogony follow trophozoite development. Type 1 merozoites undergo cyclic replication before developing into type 2 merozoites. Type 2 merozoites subsequently give rise to sexual stages. Fertilization follows and results in the production of oocysts which sporulate at the time of passage in feces. Autoinfective sporozoite and merozoite loops in the life cycle may perpetuate infection in immunocompromised hosts.
Since the first cases of human cryptosporidiosis were reported in 1976, Cryptosporidium has become recognized as a common cause of diarrhea in international travelers, children in day-care centers, livestock handlers, and patients with AIDS or other immune deficiency disorders. Among several recent studies that have addressed the prevalence of C. parvum infection in AIDS patients with diarrhea, one study identified Cryptosporidium as the most common enteropathogen in diarrheic AIDS patients (Laughon et al. Gastroenterol. 94:984 (1988)). Dissemination to extraintestinal sites such as the esophagus, lungs, pancreas and liver has also been shown to occur in immune deficient patients (Soave et al. Rev. Inf. Dis. 8:1012 (1986); Ungar et al. xe2x80x9cCryptosporidiosis in Humansxe2x80x9d pp. 67-75, in J P Dubey, C A Speer and R Fayer (eds.), Cryptosporidiosis of Man and Animals, CRC Press (1990)).
Unlike the other major causes of diarrhea, including infection by E. coli, rotavirus and coronavirus, there are no effective control measures available for cryptosporidiosis. Despite the evaluation of more than 90 drugs, none has been of consistent value and no immunization regimen is presently available to protect against infection by C. parvum. Control of C. parvum infection therefore depends on achieving an adequate immune response. An index of adequate response comprises resistance to reinfection following recovery and short-term disease in immunocompetent hosts. The disease may persist however in immunodeficient hosts.
While cell-mediated immunity is important to naturally occurring resistance to many coccidial species, the evidence suggests that antibody responses can also be manipulated to control infection with sporozoan parasites. For example, hyperimmune bovine serum or colostral whey against whole C. parvum neutralized sporozoite infectivity and partially protected mice and calves against oocyst challenge. Additionally, oral administration of hyperimmune bovine colostrum to persistently infected immunodeficient patients was followed by cessation of diarrhea and oocyst shedding. Further, monoclonal antibodies (mAbs) reactive with C. parvum sporozoite and merozoite surface epitopes neutralized their infectivity and partially protected mice against oocyst challenge.
According to a first aspect of the invention there is provided a monoclonal antibody having the epitope binding specificity of antibody 3E2. In one embodiment, the monoclonal antibody and antibody 3E2 compete with each other for binding to an antigen that is present in a preparation solubilized C. parvum sporozoites. This monoclonal antibody, which competes with antibody 3E2 for antigen binding, stimulates a CSP-like reaction after contacting C. parvum sporozoites. According to a different embodiment, the monoclonal antibody can have an IgM isotype. In a particular case, the monoclonal antibody is antibody 3E2. The invention also provides a hybridoma that secretes the monoclonal antibody 3E2.
According to a second aspect of the invention there is provided a pharmaceutical composition for administration to a mammal, comprising a monoclonal antibody secreted by hybridoma 3E2 and a pharmaceutically acceptable carrier. The invented composition also can include at least one monoclonal antibody other than the monoclonal antibody secreted by hybridoma 3E2. In a preferred embodiment, this other monoclonal antibody has an epitope binding specificity different from the binding specificity of the monoclonal antibody secreted by hybridoma 3E2. The carrier of the pharmaceutical composition can include at least one stabilizing agent which may be a protease inhibitor, a carrier protein or a pH buffering agent. In one embodiment, the carrier optionally comprises colostrum, for example, bovine colostrum.
A third aspect of the invention relates to a method of providing to a mammal passive immunity against C. parvum infection, comprising the step of administering to the mammal a composition comprising antibody 3E2, thereby providing passive immunity. In one embodiment, the composition administered to the mammal comprises a C. parvum neutralizing amount of monoclonal antibody 3E2. According to a different embodiment, the administered composition includes at least one monoclonal antibody other than antibody 3E2 that specifically binds a C. parvum antigen. In a preferred method the composition comprising antibody 3E2 is administered orally in the administering step. In another preferred embodiment of the method, the mammal is a human and in a particularly preferred embodiment the mammal is an immunocompromised human.
A fourth aspect of the invention relates to an isolated circumsporozoite-like antigen of C. parvum which includes a glycoprotein having a molecular weight of 1,400 kDa and which harbors an epitope specifically recognizable by monoclonal antibody 3E2. The isolated antigen can be isolated by a method that includes centrifugation, more particularly, density gradient centrifugation. Alternatively, the isolated antigen can be isolated by methods that involve immunoprecipitation, isoelectric focusing or preparative polyacrylamide gel electrophoresis.
A fifth aspect of the invention relates to an immunogenic composition which includes: (a) a substantially purified C. parvum antigen specifically recognizable by monoclonal antibody 3E2; and (b) a pharmaceutically acceptable carrier. In one embodiment, the C. parvum antigen is a glycoprotein with a molecular weight of approximately 1,400 KDa. In another embodiment, the carrier of the immunogenic composition can include an adjuvant.
A sixth aspect of the invention relates to a method of neutralizing C. parvum infection in a mammal, where the method includes the step of administering to the mammal a composition which includes an antibody having binding specificity for an epitope specifically recognizable by mAb 3E2. The administered composition can include monoclonal antibody 3E2 itself, and may include a C. parvum neutralizing amount of monoclonal antibody 3E2. Alternatively, the administered composition can include at least one monoclonal antibody other than monoclonal antibody 3E2. The administered composition can be administered orally.
Still another aspect of the invention relates to a method of stimulating an anti-C. parvum immune response in an animal. Practice of the invented method involves first obtaining an immunogenic composition that includes a purified C. parvum antigen dispersed in a pharmaceutically acceptable carrier, where the antigen is specifically recognizable by mAb 3E2, and then administering the composition to the animal according to a vaccination protocol. The immunogenic composition used in the invented method optionally can include an adjuvant.
As disclosed herein, the 3E2 monoclonal antibody (mAb) has binding-specificity for a C. parvum surface and apical glycoprotein complex of sporozoites and merozoites, and efficiently neutralizes C. parvum infection in vivo. Interestingly, the epitope recognized by the mAb 3E2 exhibits properties consistent with a carbohydrate/carbohydrate-dependent structure. More particularly, the target epitope, immobilized in a Western blotting format, was sensitive to degradation by glycosidase and degradation by periodate treatment, but resistant to protease digestion in a dot-blotting format. Thus, it is highly unlikely that the epitope could be expressed in recombinant form in a procaryotic host, for example. As will be apparent from the following disclosure, the production and isolation of the 3E2 hybridoma was made possible by the use of purified native C. parvum antigens as immunogens.
The present invention is useful for treating and preventing cryptosporidiosis in all mammals, including human neonates, and also in immunodeficient and certain immunocompetent children and adults. More particularly, the invented composition comprising the mAb 3E2 can be administered to young ruminants, for example, calves, goats and sheep. The invention is useful in these applications because young domestic ruminants serving as food animals are typically housed under conditions where exposure to C. parvum is unavoidable and typically do not possess functionally mature immune systems capable of fighting off infection at the time of exposure to the parasite. Another application of the invention relates to the control of cryptosporidiosis in humans having acquired or congenital immunodeficiencies, including individuals having acquired immunodeficiency syndrome (AIDS) resulting from infection with the human immunodeficiency virus (HIV).
Therapeutic or prophylactic compositions falling within the scope of the invention include preparations containing the mAb 3E2, optionally containing stabilizing agents including protease inhibitors, carrier proteins and pH buffering agents. A convenient source of agents known to stabilize antibodies, particularly when administered by oral route, is colostrum. Colostrum naturally contains antibodies which can, for example, be passed to a neonate. Thus, contemplated formulations for delivery of mAb 3E2 may involve dispersion of the mAb into colostrum prior to administration to a recipient mammal. Notably, experimental results presented herein proved that ascites preparations could be administered orally with strong retention of C. parvum neutralizing activity characteristic of mAb 3E2. This confirmed the utility of mAb 3E2 as an agent having powerful neutralizing activity directed against the parasite, C. parvum.
As disclosed herein, we have employed competition binding assays to identify mAbs having binding specificities for the same, similar or overlapping epitopes. Results of testing using these assays revealed that mAbs which neutralize C. parvum infection in vivo and which elicit the CSP-like reaction upon contacting sporozoites all have binding specificities that overlap the binding specificity of mAb 3E2. In view of the identity between neutralizing mAbs having the ability to elicit the CSP-like reaction and those having the ability to compete with mAb 3E2 for antigen binding, we concluded that identification of mAbs that compete with mAb 3E2 for antigen binding represents a method of identifying mAbs that can stimulate the CSP-like reaction in C. parvum. Moreover, our results support that any mAb that specifically competes with mAb 3E2 for antigen binding will also have neutralizing activity and be capable of stimulating the CSP-like reaction.
Another aspect of the invention relates to a method of stimulating an anti-C. parvum immune response in an animal using as an immnunogen a purified glycoprotein constituent of C. parvum, wherein the constituent is characterized as a target for binding by mAb 3E2. Immunization with characterized molecules known to be the antigenic targets of a neutralizing humoral immune response, advantageously focuses the immune response against critical epitopes rather than against potentially irrelevant epitopes otherwise found in whole organism preparations. As described below, we have now defined critical epitopes disposed on the surface of C. parvum to which an antibody response must be directed in order to optimize immunoprotection against infection by this organism.
The hybridoma cell line secreting mAb 3E2-A8-B2 (3E2) has been deposited on Mar. 28, 1996 with the American Type Culture Collection Manassas, Va. in compliance with the procedures specified for the deposit of biological materials under the Budapest Treaty. The deposit has been assigned accession number ATCC HB 12075.
The starting point for the development of the invention involved the purification of particular native antigens from C. parvum sporozoites. The C. parvum isolate used in the procedures described herein was obtained from H. Moon (National Animal Disease Center, Ames, Iowa). The C4A1 mAb, described in detail by Mead et al. (J. Parasit. 74:135 (1988)) and Arrowood et al. (Infect. Immun. 57:2283 (1989)), was used in the following procedure as an immunoaffinity purification reagent. Significantly, the purification protocol described below advantageously allowed the isolation of C. parvum protein constituents having posttranslational modifications that would have been absent from, for example, recombinant antigens produced in a heterologous host. General methods useful in immunoaffinity purification procedures can be found in Monoclonal Antibodies: Principles and Practice, 2nd ed. J. W. Goding, Academic Press, London (1986) pp. 219-227, the disclosure of which is hereby incorporated by reference.
Example 1 describes one procedure useful for isolating antigen constituents of C. parvum.

The Arizona Board of Regents Acting on Behalf of the University of Arizona


Provided is a battery with a higher capacity and superior charge-discharge cycle characteristics. A cathode contained in a package can and an anode contained in a package cup are laminated with a separator in between. The separator is impregnated with an electrolyte solution formed by dissolving lithium salt in a solvent. The anode comprises a tin-containing material including metallic tin and an intermetallic compound including tin in the same particle. A higher capacity and superior charge-discharge cycles can be obtained by the tin-containing material.

1. Field of the Invention
The present invention relates to an anode material including tin and a battery using the anode material.
2. Description of the Related Art
In recent years, portable electronic devices such as cellular phones, camera/VTR (video tape recorder) combination systems, laptop computers or the like have come into widespread, and a reduction in size and weight of the devices have been strongly required. Accordingly, as portable power sources for the devices, research and development aimed at improving the energy density of batteries, specifically secondary batteries have been actively promoted. Among the batteries, lithium-ion secondary batteries hold great promise, because the lithium-ion secondary batteries can obtain a higher energy density than lead-acid batteries or nickel-cadmium batteries which are conventional aqueous electrolyte secondary batteries.
Conventionally, as an anode material of the lithium-ion secondary battery, a carbonaceous material such as non-graphitizable carbon, graphite or the like is widely used, because the carbonaceous material exhibits a relatively high capacity and excellent charge-discharge cycle characteristics.
However, in accordance with a recent trend toward a higher capacity, an anode is required to have a further higher capacity, so research and development has been promoted. For example, an anode including a carbonaceous material has achieved a higher capacity by selecting the carbonaceous material and a forming method (refer to Japanese Unexamined Patent Application Publication No. Hei 8-315825). However, the anode has a discharge potential of 0.8V to 1.0 V against lithium, so when a battery is formed using the anode, the battery discharge voltage becomes lower. Therefore, a significant improvement in a battery energy density is not expected. Further, there are disadvantages that a hysteresis in charge-discharge curves is large, and energy efficiency in each charge-discharge cycle is low.
On the other hand, as an anode material capable of achieving a higher capacity, for example, a material adapting a property of reversibly producing and decomposing some kind of lithium metal by an electrochemical reaction. More specifically, as such a material, a Li—Al alloy has been known since long ago. Further, a Si alloy has been reported (refer to U.S. Pat. No. 4,950,566).
However, these anode materials such as these alloys are expanded or shrunk in accordance with charge and discharge, thereby resulting in the materials being pulverized, so the cycle characteristics of the battery declines.
Therefore, in order to improve the charge-discharge cycle characteristics, an anode material in which an element not involved in expansion and shrinkage in accordance with insertion and extraction of lithium is substituted for a part has been studied. For example, LiSiaOb (0≦a, 0<b<2) (refer to Japanese Unexamined Patent Application Publication No. Hei 6-325765), LicSi1-dMdOe (M represents metal except for alkali metal or metalloid except for silicon; 0≦c, 0<d<1, 0<e<2) (refer to Japanese Unexamined Patent Application Publication No. Hei 7-230800), and a Li—Ag—Te alloy (refer to Japanese Unexamined Patent Application Publication No. Hei 7-288130) have been invented.
However, even if any of these anode materials is used, a decline in the cycle characteristics resulting from expansion and shrinkage of the alloys is large, so the fact is that full advantage cannot be taken of a higher capacity.
Moreover, D. Larcher et al. has proposed Cu6Sn5 which is an intermetallic compound as an anode material capable of achieving a higher capacity. However, in Cu6Sn5, a large decline in the charge-discharge cycle characteristics is still observed.

Anode material and battery using the same


In a method for storing data in a flash memory array, the flash memory array includes a plurality of physical pages. The method includes receiving a request to perform a data access operation through a communication bus. The request includes data and a logical page address. The method further includes allocating one or more physical pages of the flash memory array to perform the data access operation. The method further includes, based on a historical usage data of the flash memory array, selectively encoding the data contained in the logical page into the one or more physical pages.

A hard disk drive often has an associated disk cache that is used to speed up access to data on the disk since the access speed of the disk cache is significantly faster than the access speed of the hard disk drive. A disk cache is a storage device that is often a non-volatile storage device such as a flash memory. It is typically implemented by storing the most recently accessed data. When a computer needs to access new data the disk cache is first checked before attempting to read the data from the disk drive. Since data access from the cache is significantly faster than data access from the disk drive, disk caching can significantly increase performance.
Typical flash memory devices are formed from a number of individual storage elements, where each storage element consists of a memory cell that includes a transistor and a charge storage area. The presence or absence of an electronic charge in the charge storage area of a cell can be used to store a logic "1" or a logic "0" in the cell.
In general, there are a number of operations that are performed within flash memory devices. The most common such operations are the ERASE, PROGRAM, and READ operations. During an ERASE operation, the logical bit stored in a given memory cell is set to a logical "0", which—in the example of discussion—corresponds to the absence of a substantial electric charge in the memory cell's charge storage area. Because of the physical nature of most NAND flash memory devices, the ERASE operation is performed on a block basis. Thus, anytime one desires to erase the data in a given memory cell within a given block, one will also erase the data in all other memory cells within that block.
After a block of flash memory is erased, the individual data within the device can be programmed. The PROGRAM operation involves the writing of data into a memory cell that has been previously ERASED. The PROGRAM operation is performed in such a way that all of the bits being programmed (typically all of the bits within a single page) will be programmed to have the desired "1" or "0" levels at the same time. Once pages of flash memory device are programmed, they can be read. In general, the READ operation involves the reading of the logical data stored in the memory cells of a page of flash data.
Block ERASE operations are expensive in terms of power and performance because they are often preceded by a number of READ operations and PROGRAM operations as valid data is moved around the flash memory in preparation for a block erase operation. In addition, there is a fixed limit on the number of erases a flash cell (the smallest unit of flash memory) can handle, beyond which the flash cell becomes unreliable. Thus, the performance, power and reliability of flash memory can become a concern as the number of invalidations grows.

Selective write-once-memory encoding in a flash based disk cache memory

International Business Machines Corporation


In a text recognition system that uses a stochastic finite state network to model a document image layout, the computational efficiency of text line decoding is improved. In a typical implementation, the dynamic programming operation that accomplishes decoding uses actual scores computed between two-dimensional (2D) bitmapped character template images and the (2D) bitmapped observed image. Scoring measures the degree of a match between a character template and the observed image. Computation of these actual scores is replaced with the simpler computation of column-based (i.e., one-dimensional) heuristic scores. Because the column-based heuristic scores can be shown to be a true upper bound on actual template-image scores, the heuristic scores are accurate enough to use in place of actual scoring during text line decoding. The heuristic scores essentially reduce the expensive two-dimensional computation of the actual template-image scores required by prior decoding methods to a simpler but accurate one-dimensional computation.

The present invention relates generally to image decoding and image recognition techniques, and specifically to image decoding and recognition techniques using stochastic finite state networks such as Markov sources. In particular, the present invention provides a technique for producing heuristic scores for use by a dynamic programming operation in the decoding of text line images.
Automatic speech recognition systems based on stochastic grammar frameworks such as finite state Markov models are known. Examples are described in U.S. Pat. No. 5,199,077 entitled xe2x80x9cWordspotting For Voice Editing And Indexingxe2x80x9d, and in reference [2], both of which use hidden Markov models (HMMs). Bracketed numerals identify referenced publications listed in the Appendix of Referenced Documents.
Stochastic grammars have also been applied to document image recognition problems and to text recognition in particular. See, for example, the work of Bose and Kuo, identified in reference [1], and the work of Chen and Wilcox in reference [2] which both use hidden Markov models (HMMs) for word or text line recognition. See also U.S. Pat. No. 5,020,112, issued to P. A. Chou and entitled xe2x80x9cImage Recognition Using Two-Dimensional Stochastic Grammars.xe2x80x9d
U.S. Pat. No. 5,321,773, issued to Kopec and Chou, discloses a document recognition technique known as Document Image Decoding (hereafter, DID) that is based on classical communication theory. This work is further discussed in references [2], [4] and [5]. The DID model 800, illustrated in FIG. 28, includes a stochastic message source 810, an imager 811, a channel 812 and a decoder 813. The stochastic message source 810 selects a finite string M from a set of candidate strings according to a prior probability distribution. The imager 811 converts the message into an ideal binary image Q. The channel model 812 maps the ideal image into an observed image Z by introducing distortions due to printing and scanning, such as skew, blur and additive noise. Finally, the decoder 813 receives observed image Z and produces an estimate {circumflex over (M)} of the original message according to a maximum a posteriori (MAP) decision criterion. Note that in the context of DID, the estimate {circumflex over (M)} of the original message is often referred to as the transcription of observed image Z.
The structure of the message source and imager is captured formally by combining their functions into a single composite image source 815, as shown by the dotted lines in FIG. 28. Image source 815 models image generation using a Markov source. A Markov source is a stochastic finite-state automaton that describes the entire two-dimensional (2D) spatial layout and image components that occur in a particular class of document images as a regular grammar, representing these spatial layout and image components as a finite state network. Prior attempts with stochastic grammar representations of text images confined their representations to single words or single lines of text, without regard to where these words or lines were located on the 2D page. A general Markov source model 820 is depicted in FIG. 29 and comprises a finite state network made up of a set of nodes and a set of directed transitions into each node. There are two distinguished nodes 822 and 824 that indicate initial and final states, respectively. A directed transition t between any two predecessor (Lt) and successor (Rt) states in the network of FIG. 29 has associated with it a 4-tuple of attributes 826 comprising a character template, Q, a label or message string, m, a transitional probability, xcex1, and a two-dimensional integer vector displacement, xcex94.
For example, Markov source model 830 illustrated in FIG. 30 is a simple source model for the class of 2D document images that show a single column of English text in 12 pt. Adobe Times Roman font. In this model, documents consist of a vertical sequence of horizontal text lines, alternating with white (background) space. A horizontal text line is a sequence of typeset upper- and lower-case symbols (i.e., letter characters, numbers and special characters in 12 pt. Adobe Times Roman font) that are included in the alphabet used by the English language. The image coordinate system used with the class of images defined by model 830 is one where horizontal movement, represented by x, increases to the right, vertical movement, represented by y, increases downward, the upper left corner of the image is at x=y=0, and the lower right corner of the image is at x=W, y=H , where W and H respectively indicate the width and height of the image in pixels.
As illustrated in FIG. 28, a Markov source model serves as an input to an image synthesizer in the DID framework. For an ordered sequence of characters in an input message string in the English language and using model 830 of FIG. 30, the image synthesizer generates a page image of a single-text column by placing templates in positions in the page image that are specified by model 830. The operation of text column source model 830 as an image synthesizer may be explained in terms of an imager automaton that moves over the image plane under control of the source model. The movement of the automaton constitutes its path, and, in the case of model 830, follows the assumptions indicated above for the conventional reading order for a single column of text in the English language. From start state node nI at the top left corner of the image, the imager automaton enters and self-transitions through iterations of node n1 vertically downward, creating vertical white space. At some point the imager reaches the top of a text line and enters state n2 which represents the creation of a horizontal text line. The displacement (0,34) of the transition into n2 moves the imager down to the text baseline; 34 is the font height above the baseline. The self-transitions at node n2, indicated by the loop at n2 and symbols 831 and 832, represent the individual characters of the font and horizontal white space such as occurs with spaces between words. The imager transitions horizontally from left to right along the text line through iterations of node n2 until there are no more characters to be printed on the line (which may be indicated in a variety of ways not specifically shown in model 830.) At the end of the text line, the imager drops down vertically by the font depth distance 13 and transitions to node n3. At node n3 one of two things can happen. If there are remaining text lines, the imager enters xe2x80x9ccarriage returnxe2x80x9d state n4 to return to the left margin of the page and back to n1. Or, if there are no more characters or the imager has reached the bottom right corner of the page, the imager transitions from n3 to the final node nF. Node n2 may be considered the xe2x80x9cprintingxe2x80x9d state, where text lines are produced. Additional description of how an image synthesizer functions in the DID framework with model 830 may be found in U.S. Pat. No. 5,526,444 at cols. 5-7 and the description accompanying FIGS. 15-18 therein, and in U.S. Pat. No. 5,689,620, at col. 36-40 and the description accompanying FIG. 14 at col. 39-40 therein.
The attributes on the transitions in Model 830 of FIG. 30 have been simplified in this illustration. Each directed transition into n2, for example, has the associated 4-tuple of attributes shown in FIG. 29: a transition probability, a message string identifying a symbol or character in the English language, a corresponding character template in the font to be used in the page image, and a vector displacement, shown as (wt,0) in FIG. 30 that indicates the (x,y) position in the image that the path takes next. For node n2, displacement (wt,0) indicates a horizontal distance w that is the set width of the template. The set width of a template specifies the horizontal (x-direction) distance on the text line that the template associated with this transition occupies in the image.
U.S. Pat. No. 5,689,620 extended the principles of DID and the use of Markov source models to support the automatic supervised training of a set of character templates in the font of a particular collection or class of documents, thereby enabling the decoding of font-specific documents for which templates were not otherwise easily available. The use of a Markov source model to describe the spatial layout of a 2D document page and the arrangement of image components such as lines, words and character symbols on the page provides a great deal of flexibility for describing a wide variety of document layouts. This flexibility combined with automatic training of character templates in a specific font provide a powerful technological advantage in the field of automatic document recognition. DID enables the decoding (recognition) of any type of character symbols in virtually any type and size of font and in any type of 2D spatial layout.
The powerful flexibility offered by the DID system is limited in actual use by the time complexity involved in the decoding process. Decoding involves the search for the path through the finite state network representing the observed image document that is the most likely path that would have produced the observed image. U.S. Pat. No. 5,321,773 discloses that decoding involves finding the best (MAP) path through a three-dimensional (3D) decoding trellis data structure indexed by the nodes of the model and the coordinates of the image plane, starting with the initial state and proceeding to the final state. Decoding is accomplished by a dynamic programming operation, typically implemented by a Viterbi algorithm. A straightforward approach to MAP decoding is to use a two-dimensional form of a segmental Viterbi algorithm to compute a set of recursively-defined likelihood functions at each point of the image plane. The forward phase of the Viterbi procedure involves identifying, for each pixel position in the image, the most likely path for arriving at that position, from among the paths generated by the printing of each character template and by using the most likely paths for arriving at all previously computed positions. In effect, the recursive Viterbi procedure involves iterating over each image position and each transition into every node and computing the likelihood of the best path that terminates at the node and image position after passing through the transition.
With reference to the DID framework of FIG. 28, there is a set of probabilities in the image model that are derived from channel model 812. Decoder 813 looks for the most likely observed image Z that could have come from the ideal image Q, given channel model 812. Observed image Z is represented by a path through image model 815. Transcription {circumflex over (M)} is formed from the character labels identifying the templates associated with the branches in the path. Based on channel model 812, there is a certain probability distribution over a corrupted image. The probability distribution predicts certain images with certain probabilities. Decoding observed image Z involves computing a set of recursively-defined likelihood functions at each point of the image plane. The likelihood functions indicate the probability distribution evaluated on the specific set of data that is the observed image Z. Each individual node computation computes the probability that the template of a transition corresponds to a region of the image to be decoded in the vicinity of the image point. This template-image probability is represented by a template-image matching score that indicates a measurement of the match between a particular template and the image region at the image point. Producing maximum cumulative path scores at each image position using the template-image matching scores is a way of building up the likelihood in a piece by piece fashion. In terms of the decoding trellis that represents the image model, the template-image matching scores labeling the branches in the trellis are the likelihood terms.
The Viterbi procedure is carried out in the forward direction until the end-point of the best path is unambiguously identified. The backward phase of the Viterbi involves backtracing through the nodes identified as part of the best path to trace out the actual best path. The sequence of character templates associated with the transitions between each node from the start to the final node in the source model on the best path are concatenated to form the message, or transcription, of the decoded image. U.S. Pat. No. 5,526,444 discloses a more detailed description of the decoding process at cols. 7-9 and the description accompanying FIGS. 19-22 therein.
The dynamic programming operation used to decode an image involves computing the likelihood that the template of a transition corresponds to a region of the image to be decoded in the vicinity of the image point. This template-image likelihood is represented by a template-image matching score that indicates a measurement of the match between a particular template and the image region at the image point. Thus, the size and complexity of the image as defined by the model (i.e., the number of transitions) and the number of templates to be matched are major factors in computation time. Indeed, the time complexity of decoding using an image source model of the type shown in FIG. 30 and FIG. 31, and using a Viterbi or Viterbi-like algorithm, is O(∥xcex2∥xc3x97Hxc3x97W), where ∥xcex2∥ is the number of transitions in the source model and H and W are the image height and width, respectively, in pixels.
There are two factors that influence this complexity. The first is finding the baselines of horizontal text lines. Although decoding computation grows only linearly with image size, in absolute terms it can be prohibitive because, in effect, each row of pixels in the image is evaluated (decoded) as the baseline of a possible horizontal text line. For example, a two-dimensional image of a column of black text represented in a single known font printed on an 8.5xc3x9711 inch page of white background and scanned at 300 dpi resolution causes line decoding to occur 3300 times (300 dpixc3x9711 inches). Initially, when DID was first developed, decoding of such an image, without decoding efficiencies and improvements, took about 45 minutes to run, which made the system commercially impractical.
A second key bottleneck in the implementation of the dynamic programming decoding procedure is the computation of template-image matching scores. The matching operation between template and image includes aligning a template with a position in the image, performing an AND operation, and summing the resulting ON pixels, producing a score indicating the match between that template and that position of the image. Each template is matched at an image position, a score is produced, and the maximum score of all templates for that position is accumulated in a running sum to produce the score for the entire line. Thus, each template is matched at each position of a horizontal row of pixels in the image during text line decoding. If there are 100 templates and 1500-2000 x-pixel positions in a line, then each template has to be matched at each x position on the line, requiring a minimum of 105 ANDs and sums to produce actual scores for each position on the line. It was found that decoding accuracy could be improved with the use of multi-level templates (described in more detail below in the Detailed Description) which require separate template-image matching for each of several levels. Moreover, when the position of an actual baseline is not known, scoring must be done for several horizontal rows of pixels around an actual baseline before the node that transitions to the actual baseline is identified. Data showed that each template could be matched at as many as five vertical pixel positions. Thus it was estimated that actual template-image matching scoring for each text line in an image required at least 106 image-template ANDs and sums. In early implementations of DID, this computation was found to far outweigh all other parts of the decoding process.
The need to improve decoding efficiency resulted in a new view of the 2D Markov source model that provides the basic description of a page layout. U.S. Pat. No. 5,526,444 (hereafter, the ""444 ICP patent) issued to Kopec, Kam and Chou and entitled xe2x80x9cDocument Image Decoding Using Modified Branch-And-Bound Methods,xe2x80x9d discloses the use of a class of Markov source models called separable Markov models. When a 2D page layout is defined as a separable Markov source model, it may be factored into a product of 1D models that represent horizontal and vertical structure, respectively. More formally, a separable model is a collection of named Markov sub-sources that is similar to a recursive transition network. The top-level sub-source is a vertical model whose nodes are all tightly constrained to specific horizontal positions in the image. These position constraints restrict entry to the node to certain regions of the image plane. The ""444 ICP patent further discloses that decoding with a separable model involves finding the best path through the 2D decoding trellis defined by the nodes of the top-level model, some of which are position-constrained, and the vertical dimension of the image. The computational effect of a position constraint is to restrict the decoding lattice for a node to a subset of the image plane, providing significant computational savings when used with standard Viterbi decoding.
The ""444 ICP patent further discloses the use of a recursive Markov source. A recursive source is a collection of named sub-sources each of which is similar to a constrained Markov source except that it may include an additional type of transition. A recursive transition is labeled with a transition probability and the name of one of the Markov sub-sources. The interpretation of a recursive transition is that it represents a copy of the named sub-source. Thus, some of the transitions of the top-level vertical model are labeled with horizontal models. One aspect of each of the horizontal models is that every complete path through the model starts at a fixed horizontal position and ends at a fixed horizontal position, effectively reducing decoding to a one-dimensional search for the best path. A second aspect is that the vertical displacement of every complete path in the model is a constant that is independent of the vertical starting position of the path. Thus, the horizontal models describe areas of the image plane that are text lines, and the top-level vertical model with its nodes that are constrained by position defines which rows of pixels in the 2D image are to be considered as potential text lines. The match score for each branch is computed by running the horizontal model (i.e., performing the Viterbi procedure) along the appropriate row of the image. The overall decoding time for a separable model is dominated by the time required to run the horizontal models.
In conjunction with the use of separable models, the ""444 ICP patent also discloses a heuristic algorithm called the Iterated Complete Path (hereafter, ICP) algorithm that fits into the framework of the Viterbi decoding procedure utilized by DID but improves on that procedure by focusing on a way to reduce the time required to decode each of the horizontal models, or lines of text. The ICP algorithm disclosed in the ""444 ICP patent is an informed best-first search algorithm that is similar to heuristic search and optimization techniques such as branch-and-bound and A* algorithms. During decoding, ICP causes the running of a horizontal model (i.e., computes the actual template-image matching scores) for only a reduced set of transitions into each node, the reduced number of transitions being substantially smaller than the number of all possible transitions into the node. Additional information about the ICP best-first search algorithm may also be found in reference [6].
ICP reduces the number of times the horizontal models are run by replacing full Viterbi decoding of most of the horizontal rows of pixels with the computation of a simple upper bound on the score for that row. This upper bound score is developed from a heuristic function. ICP includes two types of parameterized heuristic functions. The ""444 ICP patent discloses that the parameters of both of these functions may be automatically inferred from the source model. Thus, for each area of the image where the vertical model indicates that a horizontal text line may occur, in place of performing full Viterbi decoding on each pixel row in that area as if each row could be a text baseline, a heuristic score is first developed for each horizontal row instead.
The ""444 ICP patent discloses that the first heuristic function produces a heuristic template-image matching score that is based on weighted horizontal pixel projections. In particular, a heuristic score is developed from a sum of xe2x80x9cONxe2x80x9d pixels in a region of horizontal pixel rows in the image that constitute a potential text line. The sum is weighted by a constant to produce the heuristic score. The constant is selected from a source model-dependent vector of non-negative constants that sum to one. This vector is developed from the actual templates that occur in the image and is based on the assumption that the horizontal projection profile has the same shape for every character template from a given source model. For example, for a simple text model such as model 830 in FIG. 30, the vector of constants may be computed as a linear combination of the profiles of the individual character templates, weighted by their relative character frequencies. See FIG. 23 in the ""444 ICP patent for the pseudo code of the procedure that computes the weighted horizontal pixel projection heuristic.
Decoding using the weighted pixel projection heuristic proceeds as follows. The inputs to the ICP procedure are the top-level Markov source, a procedure that computes actual template-matching scores, and a procedure that computes the weighted pixel projection heuristic scores. The ICP procedure maintains two data arrays, U and A, indexed by a vertical transition number. The elements of U are initialized with the heuristic scores for each vertical transition prior to iterations of decoding. Boolean array A keeps track of whether U contains a heuristic score or an actual score for each transition. Prior to the first iteration, Viterbi decoding of the top-level model is performed using array U containing all heuristic scores, and an estimated best path is returned. Then a loop is executed for as long as heuristic scores remain as scores in the current estimated best path. This loop includes first computing an actual template matching score for every transition in the estimated best path having a heuristic score, replacing the heuristic score in array U and updating array A to show an actual score for that transition. Then Viterbi decoding of the top-level model is performed using the scores in array U which contain both actual and heuristic scores and a current estimated best path is returned. Transitions in the current estimated best path that contain heuristic scores are identified, and the loop continues with computing an actual template matching score for every transition in the estimated best path having a heuristic score. The ICP procedure ends when the current estimated best path contains actual scores for all transitions in the path. Note that in some implementations, the ICP procedure may also conclude when the best path in a current iteration is the same as the best path in a prior iteration. Decoding concludes with producing the message string associated with the transitions in the best path. More details of the ICP procedure may be found in the ""444 ICP patent, beginning at col. 16 and the discussion accompanying FIG. 7 therein. The result of using a separable model with ICP is that actual full Viterbi decoding only takes place in regions of the image that are expected to include text lines, i.e., for those vertical transitions in the top-level vertical model that are recursive transitions.
The second heuristic is called the adjacent row heuristic and is an upper bound on the actual score for the two rows of pixels in the image that are immediately above and below the row for which an actual score has been computed. The adjacent row heuristic formalizes the observation that the actual score for a transition normally doesn""t change much from one row to the next. Thus, actual score values completed during an ICP pass may be used to infer new upper bounds on adjacent row heuristic values that are tighter than the initial upper bound heuristics. In practice, the adjacent row heuristic can be used at the end of each pass in ICP to update entries for rows in array U that are adjacent to rows having newly-computed actual score values. A coefficient is computed using parameters in the source model and the coefficient is used to produce new heuristic scores for rows above and below a row having an actual score computed during this iteration, by multiplying this coefficient by the actual score. See the ""444 ICP patent beginning at col. 23 for an illustration of how both heuristics work in the decoding of a single line of text. In the example shown, a document image having a height of 10 rows would require 10 iterations of full Viterbi decoding of the text line without the use of ICP and only three iterations of full Viterbi decoding of the text line using both ICP heuristics.
In the ""444 ICP patent, the use of a finite state model defined as a constrained and recursive Markov source combined with the ICP algorithm allow for particular transitions to be abandoned as not likely to contain the best path, thereby reducing computation time. Full decoding using the longer computation process of computing the template-image matching scores for a full horizontal line is carried out only over a much smaller number of possible transitions. The ""444 ICP patent discloses that the replacement of many long transition score computations with shorter heuristic score computations is responsible for a remarkable decrease in overall computation time reported to be a decrease by factor of 11 in one example and a decrease of a factor of 19 in another example. In an example of the decoding of a single text line image of image height H=10, illustrated in the ""444 ICP patent, it was shown that the ICP procedure implemented with both heuristics reduced the number of full-line Viterbi decoding iterations from 10 lines to 3 lines. This means that actual template-image matching scoring needed to be performed for only three of the possible 10 horizontal lines in the image.
While the invention disclosed in the ""444 ICP patent provided a significant improvement in overall decoding time over full Viterbi decoding, document recognition of a single page of single-column text using the DID method still required a commercially impractical amount of time. Experiments reported in the ""444 ICP patent (see Table 2), for example, showed a decoding time of over two minutes for a full page, single column of text. This time is largely taken up by performing full Viterbi decoding on the individual horizontal text lines, when actual scores are computed to replace the heuristic scores. The improvements provided by the technical advances disclosed in the ""444 ICP patent, while significant, did not address the efficient decoding of an individual text line. Additional reductions in the decoding time of individual text lines are desirable.
Investigation into the reasons for decoding inefficiencies using the improved decoding techniques of the ""444 ICP patent showed that replacing the heuristic scores with actual template-image matching scores during decoding of individual text lines, as required by the ICP method, was a central factor in the computation time required to decode a page of text. A full page (8xc2xdxc3x9711 inch) text document image scanned at 300 dpi (spots per inch) results in 3300 horizontal rows of pixels. Even if the ICP method reduced decoding of horizontal lines by a factor of two-thirds as suggested by the reported illustration, that would still result in over 1000 horizontal lines of decoding, requiring upwards of 106 actual scores per line. Thus, it was hypothesized that the DID method of document recognition could be improved if there were one or more ways to achieve a reduction in the computation time needed to perform full Viterbi decoding of each text line. Because scoring measures the degree of a match between a character template and the observed image, however, it was also imperative that a method for achieving such a reduction in computation time still preserve the remarkable accuracy of the DID method of document recognition.
The technique of the present invention is based on the observation that a heuristic score that was both simpler to compute than an actual score, at best as large as the actual score, and sufficiently accurate to represent an actual score in decoding computations could be used to eliminate the need to compute actual template-image matching scores during full Viterbi decoding of a text line. The present invention identifies such a scoring heuristic based on information about corresponding columns of pixels in both the templates and the image region of the text line being decoded. There are two significant advantages to the scoring heuristic of the present invention. Heuristic column-based scoring produces a true upper bound score for intra-line nodes in the stochastic finite state network that represents the document image model, and so the heuristic scores may be used during line decoding to reduce the number of actual template image matching scores that need to be computed, without sacrificing any accuracy in line decoding.
In addition, using the heuristic scores essentially reduces the two-dimensional computation of the actual template-image scores to a simpler one-dimensional computation for the heuristic scores. The simpler but accurate computation of the column-based heuristic scores provide a significant improvement in computational efficiency because they replace a very large number of computationally expensive actual template image scores required by prior decoding methods. Computing an actual score involves performing an AND operation between a 2D character template and a 2D observed image region and then summing the resulting ON pixels. A column-based heuristic score is computed using one-dimensional data structures that represent information about the counts of ON pixels in columns of the character templates and in columns of the image. These one-dimensional data structures are referred to herein as analogues, or surrogates, of the templates and image. Tests of DID on a full page document using heuristic column-based scoring in place of actual scoring during line decoding show decoding times of thirty (30) seconds or less, as compared to two minute decoding time using the ICP method disclosed in the ""444 ICP patent.
The heuristic scoring technique of the present invention may be used in any text line decoder that uses as input a stochastic finite state network that models the document image layout of the document image being decoded. Thus, it may be used in simple text line decoders as well as in the two-dimensional DID method of image recognition disclosed in the patents cited above.
Several embodiments of the heuristic scores are illustrated. In a first embodiment, a template analogue data structure for each character template is produced in the form of a one-dimensional array of the pixel counts of ON pixels in character template columns. An image analogue data structure in the form of a one-dimensional array of the pixel counts of ON pixels in observed image columns is also produced. A column-based heuristic template-image score is computed by comparing a template analogue data structure with the image analogue data structure, and then computing a sum of the minimum of the two numbers for the width of the template. A second embodiment implements column-based heuristic scoring for document image decoding systems using multi-level templates. In this embodiment, the template analogue data structure created for each template essentially functions as a lookup table for a heuristic score for a column count of ON pixels in the image, and the heuristic score is computed for an entire template by summing the individual column scores retrieved from each of the lookup tables. In still another embodiment, the upper bound heuristic score is less rigorously specified and the amount of computation required to produce the score is further reduced. This is achieved by forming the template and image analogue data structures from combined counts of ON pixels in adjacent column in the image and in the templates, and computing the heuristic scores using those analogue data structures. In effect, some pixel counts for columns are interpolated from counts in adjacent columns.
Therefore, in accordance with one aspect of the present invention, a method is provided for operating a processor-controlled machine to decode a text line image. The machine includes a processor and a memory device for storing data including instruction data the processor executes to operate the machine. The processor is connected to the memory device for accessing and executing the instruction data stored therein. The method comprises receiving an input text line image indicating a bitmapped image region including a plurality of image glyphs each indicating a character symbol. The method further comprises obtaining a plurality of character templates and character labels stored in the memory device of the machine. Each character template indicates a two-dimensional bitmapped image of a character symbol, and a character label identifying the character symbol represented by the character template.
The method further comprises producing a one-dimensional (1D) image analogue data structure using pixel counts of image foreground pixels in columns of the image portion of the input text line image, and producing a plurality of 1D template analogue data structures using pixel counts of template foreground pixels in columns of the character templates. Then a plurality of template-image heuristic scores are computed using the 1D image analogue data structure and the plurality of 1D template analogue data structures. Each template-image heuristic score indicates an estimated measurement of a match between one of the plurality of character templates and a two-dimensional region of the image portion of the input text line image. Then, the method performs a dynamic programming operation using a decoding trellis data structure. The decoding trellis data structure indicates a stochastic finite state network including nodes and transitions between nodes indicating a model of expected spatial arrangements of character symbols in the input text line image. The dynamic programming operation uses the plurality of template-image heuristic scores to decode the input text line image and produce the character labels of the character symbols represented by the image glyphs included therein.
In another aspect of the invention for decoding a text line image, producing the plurality of 1D template analogue data structures includes producing a 1D template pixel sums data structure for each character template. Each 1D template pixel sums data structure indicates counts of template column foreground pixels in groups of at least two consecutive columns of the character template. Also in this aspect of the invention, producing the 1D image analogue data structure includes producing a 1D image pixel sums data structure including counts of image column foreground pixels in at least every two adjacent column of pixels in the image portion such that the 1D image pixel sums data structure includes a combined image column count for every column of pixels in the image portion. In this aspect of the invention, computing a template-image heuristic score includes the steps of determining, for each combined template column count in the 1D template pixel sums data structure, a minimum of the combined template column count of the template column foreground pixels and the combined image column count of the image column foreground pixels, and summing the minima to produce the template-image heuristic score, such that one template-image heuristic score is computed for each 1D template pixel sums data structure at each column position in the image portion.
In another aspect of the invention for decoding a text line image, producing the 1D image analogue data structure includes computing a plurality of combined image column counts of image column foreground pixels to produce a 1D image pixel sums data structure. Computing each combined image column count includes the steps of producing a count of foreground pixels in at least every two adjacent column of the image portion, determining a maximum count of foreground pixels for each pair of consecutive counts of foreground pixels, and storing the maximum count of foreground pixels as a combined image column count in the 1D image pixel sums data structure, such that the 1D image pixel sums data structure includes a combined image column count for every other one of the columns of the image portion. Computing a template-image heuristic score includes first computing a first template-image heuristic score using the 1D template pixel sums data structure indicating a first character template at a first column position in the image portion. This computing step includes determining, for each combined template column count in the 1D template pixel sums data structure, a minimum of the combined template column count of the template column foreground pixels and the combined image column count of the image column foreground pixels, and summing the minima to produce the template-image heuristic score. Then the first template-image heuristic score is assigned as the template-image heuristic score for the first character template at a next adjacent column position in the image portion such that one template-image heuristic score is computed for each 1D template pixel sums data structure at every other column position in the image portion.

Document image decoding using text line column-based heuristic scoring


Modular audio headphone devices comprise a first user-wearable accessory and at least one headphone configured for releasable attachment to the first user-wearable accessory. The at least one headphone comprises a speaker. A speaker housing is coupled to the speaker and may be configured to form an acoustic cavity proximate at least a portion of the speaker. The at least one headphone may be configured to provide a first emitted sound pressure level (SPL) profile over a range of frequencies when the at least one headphone is attached to the first user-wearable accessory, and to provide a different second emitted SPL profile over the range of frequencies when the at least one headphone is not attached to the first user-wearable accessory.

Conventional portable audio systems often include a pair of headphones that are connected to a media player (e.g., by one or more wires or by wireless technology). Recently, modular headphones have been developed that may be attached to a headband and used in a conventional manner by wearing the headband with the headphones attached thereto on the head, as well as by removing the headphones from the headband and mounting or otherwise attaching them to another user-wearable accessory or clothing, such as a skull cap, goggles, a helmet, a hooded sweatshirt, etc. Such modular headphones are disclosed in, for example, U.S. Patent Application Pub. No. 2011/0235819, published Sep. 29, 2011, now U.S. Pat. No. 8,542,859, issued Sep. 24, 2013, to Alden, the disclosure of which is incorporated herein in its entirety by this reference.

Modular audio devices configured to emit differing sound profiles and related methods


A dialysis machine includes: a hardware unit including at least one pump actuator, at least one valve actuator and a cassette interface, the cassette interface including: (i) a plate that abuts the cassette; (ii) at least one pump aperture defined by the plate; (iii) at least one pump head moveable out of and retractable into the at least one pump aperture to operate a pumping portion of the cassette; (iv) at least one valve aperture defined by the plate; (v) at least one valve apparatus moveable out of and retractable into the at least one valve aperture to operate a valve portion of the cassette; (vi) at least one sensor aperture defined by the plate; and (vii) at least one sensor located in the least one sensor aperture, the at least one sensor operable with a sensor portion of the cassette.

The present invention generally relates to medical fluid systems. More specifically, the present invention relates to systems and methods of performing cassette-based dialysis and devices related thereto.
Due to various causes, a person's renal system can fail. Renal failure produces several physiological derangements. The balance of water, minerals and the excretion of daily metabolic load is no longer possible and toxic end products of nitrogen metabolism (urea, creatinine, uric acid, and others) can accumulate in blood and tissues.
Kidney failure and reduced kidney function have been treated with dialysis. Dialysis removes waste, toxins and excess water from the body that would otherwise have been removed by normal functioning kidneys. Dialysis treatment for replacement of kidney functions is critical to many people because the treatment is life saving.
Hemodialysis and peritoneal dialysis are two types of dialysis therapies used commonly to treat loss of kidney function. Hemodialysis treatment utilizes the patient's blood to remove waste, toxins and excess water from the patient. The patient is connected to a hemodialysis machine and the patient's blood is pumped through the machine. Catheters are inserted into the patient's veins and arteries so that blood can flow to and from the hemodialysis machine. The blood passes through a dialyzer of the machine, which removes waste, toxins and excess water from the blood. The cleaned blood is returned to the patient. A large amount of dialysate, for example about 120 liters, is consumed to dialyze the blood during a single hemodialysis therapy. Hemodialysis treatment lasts several hours and is generally performed in a treatment center about three or four times per week.
Peritoneal dialysis uses a dialysis solution or "dialysate", which is infused into a patient's peritoneal cavity via a catheter. The dialysate contacts the peritoneal membrane of the peritoneal cavity. Waste, toxins and excess water pass from the patient's bloodstream, through the peritoneal membrane and into the dialysate due to diffusion and osmosis, i.e., an osmotic gradient occurs across the membrane. The spent dialysate is drained from the patient, removing waste, toxins and excess water from the patient. This cycle is repeated.
There are various types of peritoneal dialysis therapies, including continuous ambulatory peritoneal dialysis ("CAPD"), automated peritoneal dialysis ("APD"), including tidal flow APD and continuous flow peritoneal dialysis ("CFPD"). CAPD is a manual dialysis treatment. The patient connects manually an implanted catheter to a drain, allowing spent dialysate fluid to drain from the peritoneal cavity. The patient then connects the catheter to a bag of fresh dialysate, infusing fresh dialysate through the catheter and into the patient. The patient disconnects the catheter from the fresh dialysate bag and allows the dialysate to dwell within the peritoneal cavity, wherein the transfer of waste, toxins and excess water takes place. After a dwell period, the patient repeats the manual dialysis procedure, for example, four times per day, each treatment lasting about an hour. Manual peritoneal dialysis requires a significant amount of time and effort from the patient, leaving ample room for improvement.
Automated peritoneal dialysis ("APD") is similar to CAPD in that the dialysis treatment includes drain, fill, and dwell cycles. APD machines, however, perform the cycles automatically, typically while the patient sleeps. APD machines free patients from having to manually perform the treatment cycles and from having to transport supplies during the day. APD machines connect fluidly to an implanted catheter, to a source or bag of fresh dialysate and to a fluid drain. APD machines pump fresh dialysate from the dialysate source, through the catheter, into the patient's peritoneal cavity and allow the dialysate to dwell within the cavity and the transfer of waste, toxins and excess water to take place. APD machines pump spent dialysate from the peritoneal cavity, though the catheter, to the drain. As with the manual process, several drain, fill and dwell cycles occur during APD. A "last fill" occurs at the end of CAPD and APD, which remains in the peritoneal cavity of the patient until the next treatment.
Both CAPD and APD are batch type systems that send spent dialysis fluid to a drain. Tidal flow systems are modified batch systems. With tidal flow, instead of removing all the fluid from the patient over a longer period of time, a portion of the fluid is removed and replaced after smaller increments of time.
Continuous flow or CFPD systems clean or regenerate spent dialysate instead of discarding it. The systems flow fluid into or out of the patient, through a loop. Dialysate flows into the peritoneal cavity through one catheter lumen and out another catheter lumen. The fluid exiting the patient passes through a reconstitution device that removes waste from the dialysate, e.g., via a urea removal column that employs urease to enzymatically convert urea into ammonia. The ammonia is then removed from the dialysate by adsorption prior to reintroduction of the dialysate into the peritoneal cavity. Additional sensors are employed to monitor the removal of ammonia. CFPD systems are more complicated typically than batch systems.
Hemodialysis, APD (including tidal flow) and CFPD systems can employ a pumping cassette. The pumping cassette typically includes a flexible membrane that is moved mechanically to push and pull dialysis fluid out of and into, respectively, the cassette. Certain known systems include flexible sheeting on one side of the cassette, while others include sheeting on both sides of the cassette. Positive and/or negative pressure can be used to operate the pumping cassettes.
One problem with the pumping cassettes is leakage. If the flexible membranes experience a pinhole or tear, fluid and air can move from one side of the membrane to the other. Movement of fluid from inside the cassette to the inner workings of the machine can damage the machine. Movement of air from the machine into the cassette can compromise the sterility of the fluid pathways defined by the cassette. There are detection systems that determine when fluid leaks from the cassette to the machine. It is more difficult, however, to detect fluid leaking into the cassette.
Another problem with cassette-based pumping occurs when the cassette is loaded improperly into the machine. Proper alignment is important because portions of the flexible membrane must match corresponding machine portions, e.g., pump and valve actuators. Improper loading can lead to undue mechanical stress being placed on the cassette, harming potentially the cassette and/or the actuator. Improper cassette loading will also likely degrade or prohibit performance of the system.
A further dilemma, especially in CFPD, is the coordination of multiple fluid delivery. Cassette-based peritoneal pumping systems that administer fluids continuously to patients are required to withdraw fluid (ultrafiltrate) from and add fluid (concentrate) to a continuously flowing dialysis fluid loop. The additional fluids have typically necessitated additional dedicated pumps, which make the cassette and dialysis machine larger and noisier. Scheduling the operation of multiple pumps also presents a challenge to system implementers.
Another problem associated with cassette-based pumping is the entrapment of air or other gas into the fluid pathways. Air can enter the system via leaking connections, improper priming, faulty tubing and faulty cassettes. Patient therapy also produces various gases that enter the system. Cassette-based pumps are designed to pump fluid, not gas. Moreover, the removal and delivery of fluid from and to the patient needs to be monitored and controlled. Air and gases upset volume measurement systems that assume no air or gas exists in the fluid pathways. Air and gases can also be uncomfortable for the patient and impede proper waste removal.
It is desirable to remove air and gas from the dialysis fluid before the fluid enters the patient. To this end, cassette-based systems have been provided with air or gas vents. A need continues however to provide for more economical venting systems. Further, prior to infusion, the dialysis fluid solution is heated to body temperature, releasing gas from the solution. Known vents do not vent air or gas due to fluid heating. It is also desirable to have a method for detecting air and fluid, so that the volume of both can measured, detecting air for purging and detecting fluid for ensuring proper therapy.

Pumping systems for cassette-based dialysis


A base station includes: an allocating circuit that allocates, to a resource set which is monitored by a terminal belonging to a group, a first control signal which contains information indicating the configuration of a slot and a second control signal which does not contain the information indicating the configuration of a slot; and a transmitter that transmits the first control signal and the second control signal to a terminal. The number of symbols to which the first control signal is allocated is made equal to the smallest number of symbols to which the second control signal is allocated.

A communication system called a fifth-generation mobile communication system (5G) has been studied. In 5G, flexible provision of a function to each of the use cases in which an increase in communication traffic, an increase in the number of terminals to be connected, high reliability, and low latency are respectively required has been studied. As representative use cases, there are three use cases: enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra reliable and low latency communicantions (URLLC). 3GPP (3rd Generation Partnership Project), which is the international standard-setting organization, has studied sophistication of a communication system from the aspects of both sophistication of the LTE system and New RAT (radio access technology) (see, for example, NPL 1).

Panasonic Intellectual Proper ty Corporation of America


The present invention provides a method and system for image identification and identification result output, wherein a feature image under identification acquired from an image is compared with a plurality of sample images respectively stored in a database so as to obtain a plurality of similarity indexes associated with the plurality of sample images respectively. Each similarity index represents similarity between the feature image and the corresponding sample image. Thereafter, the plurality of similarity indexes are sorted and then a least one of comparison results is output. The present invention is further capable of being used for identifying identification marks with respect to a carrier. By sorting the similarity index with respect to each feature forming the identification marks, it is capable of outputting many sets of combinations corresponding to the identification marks so as to improve speed for targeting suspected carrier and enhance the identification efficiency.

There are many people who get killed in traffic accidents. Theft and burglary using cars/motorcycles have been repeatedly reported. These may be attributed to poor image identification of license plates because of poor monitoring systems. Such monitoring systems are mostly problematic because of poor resolution (320×240 pixels) and slant angles of the image acquiring units to cause blur or incomplete images that cannot be recognized so that the criminals can be at large.
Conventionally, in Taiwan Patent No. 197752, a CCD camera and an image acquiring unit are used to acquire a car image in the car lane and the car image is then read by an image reading unit. Then, a logarithmic greyscale operation unit is used to calculate the logarithmic greyscale of each pixel in the car image. The image corresponding to the logarithmic greyscales is decomposed by a wavelet decomposition unit into rough images, horizontally differentiated images, vertically differentiated images and diagonally differentiated images. An image binarization unit converts the logarithmic greyscale of each pixel in the horizontally differentiated images from real numbers into binary digits 0 and 1. A rough image dividing unit determines a region with the highest sum of binary digits within the whole car image according a pre-set license plate size and thus the region is initially referred to as a license plate region. Then, a license plate slantness correction unit corrects the slantness of the image corresponding to the license plate region. Finally, a fine image dividing unit removes the part that does not correspond to the license plate from the rough license plate region.
Moreover, in Taiwan Patent Pub. No. 1286027, an integrated multiple lane free flow vehicle enforcement system is disclosed, wherein a portal framed equipment is established at the image enforcement point. The car lane is physically divided so that image enforcement can be realized with respect to various cars even though the system slows the cars to pass by the image enforcement point at a normal speed and to change lanes freely.
Moreover, in Taiwan Patent Appl. No. 200802137, a serial license plate identification system is disclosed, using a license plate character region detection module to receive an image and determine each approximate license plate range in the image. Sequences of serial identical pixels in each approximate license plate range are obtained. The sequences of serial identical pixels are erased, filtered, and connected to blocks so as to obtain the image with respect to the license plate character region in each approximate license plate range and output verified image with respect to the license plate character region after verification. Then, the verified image with respect to the license plate character region is transmitted to the a license plate character dividing and identification module to acquire all the independent character images and thus all the license plate character information after the independent character images are identified.

Method and system for image identification and identification result output

Industrial Technology Research Institute


A computer implemented method of reconstructing vehicle behaviour for a vehicle that has been subject to a critical event, the method comprising: receiving vehicle sensor data associated with vehicle motion; receiving a critical event notification signal, the critical event notification signal being associated with a critical event time for the critical event; deriving, from the received vehicle sensor data, a vehicle trajectory within a time window prior and adjacent to the critical event time; analysing the vehicle trajectory to determine forces acting through the vehicle system; outputting a notification signal in the event that one or more of the determined forces exceeds one of more of the operating parameters of the vehicle.

Following a critical event such as a vehicle crash it is often desirable to recreate the behaviour of the vehicle or vehicles involved in the critical event. Such recreations may be used to determine the cause of an accident, whether there were any vehicle component failures, whether any vehicle components were taken beyond their safe operating envelope and potentially for determining responsibility for the critical event.
Current vehicle crash investigations use physical methods to recreate the critical event. Data charts relating to on-board telemetry data may also be used in prior art analysis methods which may not fully represent the vehicle behaviour around the critical event. Vehicle trajectory reconstruction may also rely on assumptions relating to the vehicle's behaviour that are taken from witness reports, which can be unreliable or incomplete, and from physical analysis from the scene.
Known vehicle trajectory reconstruction software systems often rely on reconstructing the crash scene via witness statements, photographs and skid mark measurement. Such reconstruction packages may therefore not accurately recreate vehicle trajectory due to the reliance on subjective input data.


A telecommunications network comprising a plurality of nodes interconnected via communications paths is configured by the determination of a routing plan for the traffic carried by the network. A set of possible paths, e.g. the eight shortest paths between each pair of network nodes is determined, and each path is allocated a digital code characteristic of that path identity. Groups of paths are selected, each group comprising one path from each set, and for each said group being characterised by a bit string comprising the digital codes of the paths comprising that group. These bit strings are then used as starting values or chromosomes in a genetic algorithm search procedure to generate and evaluate new path groups so as to determine an optimum combination or routing plan of paths between the network nodes.

As telecommunication s networks become more complex and the traffic load increases there is a need to determine the routing of traffic within a network so as to minimise the number of communication channels used, to reduce the risk of being unable to handle traffic and to minimise the total cost to the system operator. At present, traffic routing is determined largely on an empirical basis as a full analysis of a complex network to obtain an analytical solution is an intractable problem. It is thus very difficult if not impossible for an operator to ensure that a network is used with a high degree of efficiency under all traffic conditions. It is also difficult for an operator to provide efficient allocation of new traffic routes on demand.
The object of the present invention is to minimise or to overcome this disadvantage.

Traffic routing in a telecommunications network