A method of characterizing a nucleic acid molecule is disclosed. The method comprises synthesizing DNA in the presence of a reaction mixture comprising a nucleic acid template, a primer molecule, an enzyme that extends the primer so that a DNA molecule may be synthesized, four canonical deoxynucleoside triphosphates and at least one non-canonical deoxynucleoside triphosphate. The non-canonical deoxynucleoside triphosphate is incorporated into the synthesized DNA in place of a portion of only one canonical deoxynucleoside triphosphate. The synthesized DNA is treated with an N-glycosylase that excises a base portion of the non-canonical deoxynucleoside triphosphate from the synthesized DNA. The DNA is then treated in such a manner that the phosphodiester backbone of the DNA is broken at the abasic site, thus creating at least two DNA fragments. The fragments are separated according to size.

Methods of Characterizing Nucleic Acid Molecules
There are many reasons for characterizing nucleic acid molecules. For example, genes are rapidly being identified and characterized which are causative or related to many human, animal and plant diseases. Even within any particular gene, numerous mutations are being identified that are responsible for particular pathological conditions. Thus, although many methods for detection of both known and unknown mutations have been developed (e.g., see Cotton, 1993), our growing knowledge of human and other genomes makes it increasingly important to develop new, better, and faster methods for characterizing nucleic acids. Besides diagnostic uses, improved methods for rapidly characterizing nucleic acids will also be useful in many other areas, including human forensics, paternity testing, animal and plant breeding, tissue typing, screening for smuggling of endangered species, and biological research.
A variety of methods for characterizing DNA molecules are known in the art. For example, one can characterize DNA molecules by size based on their electrophoretic migration through an agarose or polyacrylamide gel. In these methods, the negatively charged DNA molecules move through a gel in the direction of the positively charged electrode. Provided that the percentage of agarose or polyacrylamide in the gel is appropriate for the size range of the DNA molecules being electrophoresed, smaller DNA molecules move through the pores of the gel more readily than larger DNA molecules. Because DNA molecules move in the gel at size-dependent rates, molecule sizes can be determined by staining and visualizing the DNA and then comparing the migration of the sample DNA molecules in the gel with the migration of marker DNA molecules of known size. Under the appropriate conditions, single-stranded DNA molecules differing in length by even a single nucleotide can be distinguished by denaturing polyacrylamide gel electrophoresis.
Another way to characterize DNA molecules is to treat each DNA molecule with one or more restriction endonucleases and then to determine the sizes of the various DNA fragments resulting from this treatment by agarose gel electrophoresis. Restriction endonucleases are enzymes that recognize specific sequences of bases in DNA (often 4, 5, 6 or sometimes 8 bases on each DNA strand) and then cut the phosphodiester bonds of the polynucleotide chains of DNA within to the recognition sequence. Because many restriction endonucleases with different recognition sequences are available, one can obtain a restriction map of an entire DNA molecule showing locations of restriction enzyme recognition sites and distances between them by determining which other restriction enzymes will cut each DNA fragment generated by any given restriction enzyme and what are the sizes of all of the resulting fragments. Such a restriction map is characteristic for a particular DNA molecule and can be used to obtain a rough identification of a particular sequence. Additionally, changes such as those caused by mutations in DNA may result in a loss or gain of a restriction site--a so-called "restriction fragment length polymorphism" (RFLP) (Kazazian, et al., 1989). An example of a diagnostically significant RFLP is a single base mutation in the beta-hemoglobin gene, the change from A to T which eliminates a Dde I restriction site, which results in sickle cell anemia (Kazazian, et al., 1989).
One of the most informative ways to characterize a DNA molecule is to determine its nucleotide sequence. One method for sequencing DNA (Maxam and Gilbert, 1977) is accomplished by treating each of four aliquots of one strand of a 5'- or 3'-end-labelled DNA molecule to be sequenced with one of four different chemical reagents. One chemical specifically modifies only the guanine base in the DNA, another modifies only cytosine, another modifies either guanine or adenine bases, and the last chemical modifies either thymine or cytosine bases. The chemical treatments are carried out under conditions so that only a small proportion of the total susceptible bases will actually be modified.
It is important that the chemical reactions are limited in order to generate a nested set of fragments differing by one base of a specific type. If all G residues, for example, were modified, the residues would all be susceptible to phosphodiester bond cleavage. Therefore, a collection of partially modified nucleic acids is required for sequencing. Subsequent treatment with piperidine results in cleavage of the phosphodiester bonds of the DNA molecule at the abasic sites, generating a mixture of all sizes of DNA molecules that are possible following chemical modification and loss of each one of the corresponding susceptible bases. The DNA molecules in each of the four reactions are then resolved by electrophoresis in adjacent lanes of a polyacrylamide gel and the pattern of bands is revealed by exposing the gel to X-ray film if the DNA molecules are labelled with a radioisotope. The sequence of the DNA is revealed by analyzing the exposed X-ray film. Alternatively, if the DNA molecules are labelled with a fluorescent, chemiluminescent or some other non-radioactive moiety, the sequence is revealed by an appropriate method known in the art.
The most commonly used method for sequencing DNA at this time (Sanger, et al., 1977) uses a DNA polymerase to produce differently sized fragments depending on the positions (sequence) of the four canonical bases (A=Adenine; C=Cytidine; G=Guanine; and T=Thymine) within the DNA to be sequenced. In this method, the DNA to be sequenced is used as a template for in vitro DNA synthesis. In addition to all four of the canonical deoxynucleotides (dATP, dCTP, dGTP and dTTP), a 2',3'-dideoxynucleotide is also included in each in vitro DNA synthesis reaction at a concentration that will result in random substitution of a small percentage of a canonical nucleotide by the corresponding dideoxynucleotide. Thus, each DNA synthesis reaction yields a mixture of DNA fragments of different lengths corresponding to chain termination wherever the dideoxynucleotide was incorporated in place of the normal deoxynucleotide. The DNA fragments are labelled, either radioactively or non-radioactively, by one of several methods and the label(s) may be incorporated into the DNA by extension of a labelled primer, or by incorporation of a labelled deoxy or dideoxy nucleotide. By carrying out DNA synthesis reactions for each of the four dideoxynucleotides (ddATP, ddCTP, ddGTP or ddTTP), then separating the products of each reaction in adjacent lanes of a denaturing polyacrylamide gel, and detecting those products by one of several methods, the sequence of the DNA template can be read directly.
Cycle Sequencing is a variation of Sanger sequencing that achieves a linear amplification of the sequencing signal by using a thermostable DNA polymerase and repeating chain terminating DNA synthesis during each of multiple rounds of denaturation of a template DNA (e.g., at 95.degree. C.), annealing of a single primer oligonucleotide (e.g., at 55.degree. C.), and extension of the primer (e.g., at 70.degree. C.).
Nucleic acid sequencing provides the highest degree of certainty as to the identity of a particular nucleic acid. Also, nucleic acid sequencing permits one to detect mutations in a gene even if the site of the mutation is unknown. Sequencing data may even provide enough information to permit an estimation of the clinical significance of a particular mutation or of a variation in the sequence.
In order to characterize a nucleic acid by sequencing, the nucleic acid must be isolated in sufficient quantity to be used for the particular method. Although it may be possible to obtain sufficient quantities of a nucleic acid for sequencing by first cloning it into a plasmid or other vector, this procedure is time-consuming and is often not practical for routine analysis of samples for clinical diagnostics or other purposes. When the amount of nucleic acid in a sample is less than optimal for a given method, it may be advantageous to use one of several methods which have been developed for amplifying parts of nucleic acid molecules. The polymerase chain reaction (PCR), nucleic acid sequence-based amplification (NASBA), self-sustained sequence replication (3SR), transcription-mediated amplification (TMA) and strand displacement amplification (SDA) are examples of some of the methods which have been developed for amplifying nucleic acid molecules in vitro.
By way of example, a specific portion of a DNA molecule may be amplified using PCR by temperature cycling of a sample DNA in a buffer containing two primers (one primer complementary to each of the DNA strands and which, together, flank the DNA sequence of interest), a thermostable DNA polymerase, and all four canonical 2'-deoxynucleoside-5'-triphosphates (dATP, dCTP, dGTP and dTTP). The specific nucleic acid sequence is geometrically amplified during each of about 30 cycles of denaturation (e.g., at 95.degree. C.), annealing of the two primers (e.g., at 55.degree. C.), and extension of the primers by the DNA polymerase (e.g., at 70.degree. C.), so that up to about a billion copies of the nucleic acid sequence are obtained. RNA may be similarly amplified using one of several protocols for RT-PCR, such as, for example, by carrying out the reaction using a thermostable DNA polymerase which also has reverse transcriptase activity (Myers and Gelfand, 1991).
The polymerase chain reaction (PCR), as discussed above, is the subject of numerous publications, including Mullis, KB, et al., U.S. Pat. No. 4,683,202 and U.S. Pat. No. 4,683,195; Mullis, KB, EP 201,184; Ehrlich, H., EP 50,424, EP 84,796, EP 258,017, & EP 237,362; Ehrlich, H., U.S. Pat. No. 4,582,788; Saiki, R., et al., U.S. Pat. No. 4,683,202; Mullis, KB, et al. (1986) in Cold Spring Harbor Symp. Quant. Biol. 51:263; Saiki, R., et al. (1985) Science 230:1350; Saiki, et al. (1985) Science 231:487; and Loh, EY, et al. (1988) Nature 335:141.
By way of a second example, all or a specific portion of an RNA molecule may be amplified using NASBA (Fahy, et al., 1991) by isothermal incubation of a sample RNA in a buffer containing two primers (a first primer complementary to the RNA molecule and encoding a promoter sequence for an RNA polymerase and a second primer complementary to the 3'-end of the first cDNA strand resulting from reverse transcription of the RNA molecule), an RNA- and DNA-dependent DNA polymerase which also has RNase H activity (or a separate RNase H enzyme), all four canonical 2'-deoxynucleoside-5'-triphosphates (dATP, dCTP, dGTP and dTTP), an RNA polymerase that recognizes the promoter sequence of the first primer, and all four ribonucleoside-5'-triphosphates (rATP, rCTP, rGTP and rUTP).
A first cDNA strand is synthesized by extension of the first primer by reverse transcription. Then, the RNase H digests the RNA of the resulting DNA:RNA hybrid, and the second primer primes synthesis of the second cDNA strand. The RNA polymerase then transcribes the resultant double-stranded DNA (ds-DNA) molecule from the RNA polymerase promoter sequence, making many more copies of RNA, which in turn, are reverse-transcribed into cDNA and the process begins all over again. This series of reactions, from ds-DNA through RNA intermediates to more ds-DNA, continues in a self-sustained way until reaction components are exhausted or the enzymes are inactivated. DNA samples can also be amplified by other variations of NASBA or 3SR.
Strand Displacement Amplification (SDA) is another isothermal nucleic acid amplification technique (Walker, 1994). SDA is a method of nucleic acid amplification in which extension of primers, displacement of single stranded extension products, annealing of primers to the extension products (or the original target sequence) and subsequent extension of the primers occurs concurrently in the reaction mix. This is in contrast to the PCR, in which the steps of the reaction occur in discrete phases or cycles as a result of the temperature constraints of the reaction. SDA is based upon 1) the ability of a restriction endonuclease to nick the unmodified strand of a hemiphosphorothioate form of its double-stranded recognition site and 2) the ability of certain polymerases to initiate replication at the nick and displace the downstream non-template strand. After an initial incubation at increased temperature (about 95.degree. C.) to denature double-stranded target sequences for annealing of the primers, subsequent polymerization and displacement of newly synthesized strands takes place at a constant temperature (usually about 37.degree. C.). Production of each new copy of the target sequence consists of five steps: 1) binding of amplification primers to an original target sequence or a displaced single-stranded extension product previously polymerized, 2) extension of the primers by exonuclease deficient (exo.sup.-) klenow polymerase incorporating an .alpha.-thio deoxynucleoside triphosphate, 3) nicking of a hemiphosphorothioate double-stranded restriction site, 4) dissociation of the restriction enzyme from the nick site, and 5) extension from the 3'-end of the nick by exo.sup.- klenow with displacement of the downstream non-template strand. Nicking, polymerization and displacement occur concurrently and continuously at a constant temperature because extension from the nick regenerates another nickable restriction site. When primers which hybridize to both strands of a double-stranded target sequence are used, amplification is exponential, as the sense and antisense strands serve as templates for the opposite primer in subsequent rounds of amplification.
PCR, NASBA and the other methods of nucleic acid amplification can be very useful for obtaining greater quantities of a nucleic acid for additional characterization. However, in general, the amplified nucleic acid molecules must be purified away from primers, nucleotides, incomplete amplification products and other impurities prior to being used for sequencing. Otherwise, for example, the PCR primers may compete with labelled sequencing primers and the PCR nucleotides may compete with the sequencing nucleotide mixes that are used for Sanger dideoxy sequencing. Also, Sanger sequencing clearly can not be done at the same time as PCR or another amplification method, at least not efficiently, because the dideoxynucleotides used for sequencing will result in termination of the DNA amplification reactions as well as the sequencing reactions.
One group has developed a method that attempts to decrease the number of steps required for sequencing nucleic acids (Shaw and Porter, PCT WO 95/06752). According to this method, 5'-alpha-borano-deoxynucleoside triphosphates, which were found to be resistant to exonuclease III (exo III) digestion, were incorporated into DNA during in vitro DNA synthesis in lieu of one of the canonical nucleotides (dATP, dCTP, dGTP, dTTP) in one of four primer extension reactions. Treatment with exo III will digest the synthesized DNA up to the point of alpha-borano deoxynucleoside incorporation. After digestion with exo III and resolution of the labeled fragments on a polyacrylamide gel, the sequence of the nucleic acid can determined.
An advantage of the alpha-borano/exo III method is that it can be integrated into PCR amplification. However, there are also disadvantages. A key disadvantage is a lower degree of accuracy of the sequence data compared to Maxam-Gilbert or Sanger sequencing because the alpha-borano/exo III method gives both extra bands and missing bands on sequencing gels. Although the mechanism by which these sequencing artifacts are generated is still uncertain, the extra bands may be due to incomplete digestion of non-boronated regions of DNA by exo III, while missing bands may be due to preferential digestion by exo III through some sequences containing alpha-borano-nucleotides. Another serious disadvantage of the alpha-borano/exo III method is related to the substrate requirements of exo III. Because exo III digests only double-stranded DNA, beginning at the 3'-end of each strand, the sequence can only be determined for the 3'-half of each strand of a PCR product, so it is not possible to obtain the sequence near to the primer. Also, because exo III digestion yields only fragments that are between 50% and 100% of the length of the full-size PCR product, the size range of the DNA which can be sequenced by the method is somewhat limited. For example, if a PCR product of 1000 base pairs in length is sequenced according to the alpha-borano/exo III method, the fragments to be electrophoresed would be approximately 500-1000 nucleotides long. Fragments of such a length are more difficult to resolve in DNA sequencing gels.
Uracil N-Glycosylase
"Uracil N-glycosylase" or "uracil-DNA glycosylase" (UNG or UDG) is an enzyme that catalyzes the cleavage of the N-glycosidic bond between the base uracil and the sugar deoxyribose in DNA into which the non-canonical nucleotide 2'-deoxyuridine-5'-triphosphate (dUTP) has been incorporated in place of the canonical nucleotide dTTP (Lindahl, 1979). UDG does not catalyze cleavage of uracil from free dUTP, free deoxyuridine or RNA (Duncan, 1981).
U.S. Pat. No. 5,035,996 describes a process in which UDG is used for controlling contamination of nucleic acid amplification reactions (Hartley, U.S. Pat. No. 5,035,996).
The purpose of this invention was to pretreat reaction mixtures containing a new sample on which an amplification is to be carried out with UDG to assure that any uracil-containing DNA from a prior amplification of another sample had been destroyed and would not contaminate the second amplification reaction. Digesting the second amplification mixture with UDG prior to carrying out the second amplification reaction destroys the ability of any residual products of the first amplification from serving as a template for further amplifications.
Somewhat similarly, U.S. Pat. No. 5,418,149 discloses the use of glycosylases to reduce non-specific amplification of nucleic acids.
A method for introducing site-specific mutations into DNA has also been described that relies upon replacement of thymine with uracil in DNA and subsequent treatment with uracil-DNA glycosylase. See U.S. Pat. No. 4,873,192 and Kunkel, 1985. Also, uracil-containing phage were suggested as a part of a biological containment system that would transfer genetic information only to uracil-N glycosylase deficient cells and not to naturally occurring bacteria. See Warner, et al., 1979.
Another use for UDG in molecular biology has been described by Nisson, et al., 1991. In Nisson, et al. UDG is used to facilitate directional cloning of PCR products. Thus, primers to be used for PCR amplification are made to contain a specific 12-base 5' sequence that contains dUMP in place of dTMP. Then, after the PCR amplification (without dUTP in the reaction mixture), since the amplification products contain dUMP residues at each 5' terminus, treatment of these PCR products with UDG removes the uracil residues from the 5' termini. Subsequent treatment with heat results in cleavage of the phosphodiester bonds at the abasic sites where uracil has been lost and thereby, generates 12-base cohesive termini which can be easily cloned into vectors with complementary termini.
What is needed in the art is a method for characterizing nucleic acids that is as accurate and as specific as Maxam-Gilbert or Sanger sequencing in detecting and identifying nucleic acids and differences between nucleic acids, but that is easier, faster, more sensitive and/or requires less sample DNA. The new method should also be capable of being used for relatively impure nucleic acid samples, such as amplification products, without needing to purify the sample away from primers, nucleotides or other impurities. The method also should be capable of being integrated into an amplification method such as PCR in a way similar to the alpha-borano/exo III method, but without having the disadvantages of the latter method.

Method for characterizing nucleic acid molecules


An inverted V-shaped bulkhead void filler for filling empty spaces in a cargo area during shipping includes a novel non-pivotable, but disengagable, interlocking structure. The bulkhead void filler includes first and second rigid panels of a sandwich-type construction attached by the interlocking structure at an upper end of each of the panels. To form the novel non-pivotable, but disengagable, interlocking structure, the second panel includes a side clip and end clips attached to its upper end. The clips define a gap substantially equal to the width or thickness of a leg of the core. The leg of the core of the first panel is slid into the gap and held securely therein.

The use of light-weight bulkhead void fillers is well-known in the art. For example, U.S. Pat. No. 5,132,156 presents an inverted V-shaped, light weight void filler that is comprised of two panels connected at their upper ends by a pivotable connection. The panels may be moved from a closed, side-by-side position to an open inverted V position by moving the bottom ends of the panels outwardly. The void filler relies on a limiter to prevent the panels from spreading too great of a distance and collapsing outwardly.
Under certain conditions, however, this type of void filler can collapse. For example, if the load generated by the cargo during shipment is not distributed in a uniform manner on this prior art void filler, it has the tendency to collapse by pivoting to the closed, side-by-side configuration.
The present invention is intended to overcome or minimize problems associated with prior art void fillers, as well as to present several other improvements.


The time over which a digital signature can be verified is extended well beyond the expiration of any or all of the certificates upon which that signature depends. A xe2x80x9csave statexe2x80x9d approach is disclosed, in which an archive facility is used to store public key infrastructure (PKI) state, e.g. cryptographic information, such as certificates and certificate revocation lists (CRLs), in addition to non-cryptographic information, such as trust policy statements or the document itself. This information comprises all that is necessary to re-create the signature verification process at a later time. When a user wants to reverify the signature on a document, possibly years later, a long term signature verification (LTSV) server re-creates the precise state of the PKI at the time the document was originally submitted. The LTSV server restores the state, and the signature verification process executes the exact process it performed (or would have performed) years earlier. In another embodiment the strength of cryptography is combined with the proven resilience of (non-public key) technology and procedures currently associated with secure data stores by saving the PKI state for future reverification; and protecting the PKI state information from intrusion by maintaining it in a secure storage facility which is protected by services, such as firewalls, access control mechanisms, audit facilities, intrusion detection facilities, physical isolation, and network isolation.

1. Technical Field
The invention relates to the use of digital signatures. More particularly, the invention relates to a method and apparatus for the long term verification of digital signatures.
2. Description of the Prior Art
The technology of digital signatures opens up the likelihood of increased use of digital networks (including the Internet) for electronic commerce. It is now feasible to send and receive digitally signed documents that represent transactions of some value to one or more parties.
Currently, a digital signature is verifiable only as long as the digital certificates upon which it depends have not expired. Given the expectation that a certificate""s life span is in the area of one to two years duration, current technology does not support the emerging needs of the electronic commerce market, where the durability of digital signatures over time is a requirement.
For certain applications, the recipient of digitally signed documents should be able to verify the authenticity of a document years after the document was signed, just as the document""s authenticity can be verified at the time of signing. Unfortunately, the current state of the technology does not provide for the verification of these digital signatures after certificate expiration because it is the nature of keys and certificates used for signing and encrypting documents to expire after a specific period of time (typically after a year or two). This is due, at least in part, to the fact that the strength of keys is expected to degrade over time because of such factors as improvements in computing speed and breakthroughs in cryptoanalysis. Moreover, the longer the key is in use, the longer that an adversary has to attempt to crack the key. Therefore, it is standard practice to replace keys periodically. This is why certificates have specific expiration dates.
An examination of the current state of the technology reveals that a digital signature verification module would fail if presented with a request to verify a signed document in which any of the associated certificates had expired. FIG. 1 is a block schematic diagram illustrating certification expiration. This simple example demonstrates that, given a certificate 10 having a two-year life span (e.g. from Apr. 1, 1996 to Apr. 1, 1998), a signature could be successfully verified six months (e.g. on Oct. 1, 1996) after certificate issuance (100); but this same signature would not be successfully verified three years later (e.g. on Apr. 1, 1999) (102). This behavior is clearly unacceptable if the duration of a document, for example contract, must extend beyond the duration of the certificates"" life.
Further, some current systems use certificate revocation lists (CRLs) to revoke certificates and remove them therefrom, once those certificates expire. This means that a record of those CRLs generally disappears, making long term signature verification impossible using known techniques.
It is known to reconstruct past trust (see A. Menezes, P. van Oorschot, S. Vanstone, Handbook of Applied Cryptography, CRC Press, pp. 583 (1996)). In this approach, both signature reverification relative to a past point in time and resolution of disputes may require reconstruction of chains of trust from a past point in time. This requires archival of keying material and related information for reconstruction of past chains of trust. Direct reconstruction of such past chains is taught to be unnecessary if a notarizing agent is used. A notarizing agent is defined as a general service capable not only of ascertaining the existence of a document at a certain time, but of vouching for the truth of more general statements at certain points in time. The original verification of the notary is taught to establish the existence of a trust chain at that point in time, and subsequently its record thereof is taught to serve as proof of prior validity. It is taught that details of the original trust chain may be recorded for audit purposes. It is not taught that a document can be verified based upon the existence of expired certificates. Rather, reliance is placed upon the use of the notarizing agent. It is further taught that the archived keying material can be used as evidence at a future time to allow resolution of disputed signatures by non-automated procedures.
It would be advantageous to provide a technique for extending the time over which the authenticity and integrity of digital signatures can be accurately verified beyond the time that any relevant certificates expire.
The invention provides a method and apparatus which effectively extends the time over which a digital signature can be verified, i.e. well beyond the expiration of any or all of the certificates upon which that signature depends. The invention can be used for any application domain where users want digital signatures to be applied to long lasting documents (e.g. contracts), and be independently verifiable years or decades after signing the document. The preferred embodiment of the invention provides two alternative approaches to constructing a solution which delivers long term signature verification (LTSV).
One embodiment of the invention provides an approach for solving the LTSV problem that is referred to herein as the xe2x80x9csave statexe2x80x9d approach. This embodiment of the invention largely entails the use of cryptographic information and techniques. Thus, an archive facility is used to store the public key infrastructure (PKI) state, e.g. cryptographic information, such as certificates and CRLS, in addition to the document itself. This information comprises all that is necessary to re-create the signature verification process at a later time. It may also be desirable to store the source document separately from the cryptographic information (such as the signature, certificates, and CRLs) for reasons of privacy. For example, a user may want to have control over the source document. The PKI state information may contain either or both of cryptographically protected information, such as certificates and CRLs, and information that is not cryptographically protected, such as the public key of a root certification authority or policy information.
When a user wants to reverify the signature on a document, possibly years later, an LTSV server re-creates the precise state of the PKI at the time the document was originally submitted. The LTSV server restores the state, and the signature verification process executes the exact process it performed (or would have performed) years earlier. The time used as the basis for re-creation of the signature verification process does not have to be the time of submittal. Rather, the time could be some other relevant time, such as when a document was signed by the originator or when it was verified by a recipient.
Another embodiment of the invention combines the strength of cryptography with the proven resilience of (non-public key) technology and procedures currently associated with secure data stores. An example of this embodiment provides a mechanism that:
Saves the PKI state for future reverification; and
Protects the PKI state information from intrusion by either maintaining it in a secure storage facility which is protected by services, such as firewalls, access control mechanisms, audit facilities, intrusion detection facilities, physical isolation, and network isolation; and/or employing a cryptographic protection mechanism, for example using the LTSV server to sign the PKI state information or using a keyed hash algorithm.
In addition, other non-cryptographic features may be added to such approaches to deliver a highly secure and trusted LTSV solution, including, for example utilities for viewing the PKI state information (cryptographic as well as non-cryptographic) and visually monitoring the security of the system. These utilities can be used to provide visual evidence for purposes of dispute resolution.
One enhancement to the secure storage approach herein disclosed maintains certain evidence, such as certificate chains, in an archive. This information need not be used for actual reverification, but merely as supporting evidence in case of a dispute.

Method and apparatus for long term verification of digital signatures

Hewlett-Packard Development Company, L.P.


A method and apparatus for fingerprint recognition is provided in accordance with the present invention to achieve a higher rate of recognition by subsequently storing fingerprint patterns with higher rates of correspondence in place of fingerprint patterns already stored having low rates of correspondence.

The present invention relates, in general, to fingerprint pattern recognition, and more particularly, to a method for fingerprint recognition with learning capability.
A fingerprint recognition apparatus is well known which recognizes a fingerprint pattern, stores the pattern in memory, and compares the subsequent entry of a fingerprint pattern with the stored fingerprint pattern to provide a correspondence signal when they correspond with each other.
For example, a fingerprint comparison apparatus is disclosed in Japanese Patent Publication No. 76964, 1988 wherein a fingerprint image to be checked is compared with a registered fingerprint image, said apparatus including a monitor which displays the fingerprint image of the finger to be compared and an indicator displaying a finger position guide on the monitor screen. Furthermore, in Japanese Patent Publication No. 149776, 1988, a fingerprint comparison apparatus is disclosed wherein a fingerprint is scanned several times for one finger at the fingerprint scanning section during fingerprint data registration and one piece of the data captured through several sessions of scanning is registered and stored as reference fingerprint data. In this fingerprint comparison system, other scanned data are compared with the reference fingerprint data to compute the rate of correspondence, which is registered and stored, whereupon the fingerprint scanned at the fingerprint scanning section is compared with said reference fingerprint data to determine the rate of correspondence, by means of which the correspondence of the scanned fingerprints is judged on the basis of whether or not the above rate of correspondence exceeds the reference level determined according to said registered and stored rate of correspondence.
In prior art fingerprint recognition apparatus, an optical signal of a fingerprint pattern is resolved into numerous segments, each of which is quantized into a binary signal, and it is determined whether the fingerprint pattern to be compared is the same as the registered fingerprint pattern according to the degree of correspondence between the segments based on said binary signal. However, it is difficult for the subject to press his or her fingerprint against the prism at a constant pressure or in a fixed direction. Therefore, even when the fingerprint pattern of a finger is registered in memory, the rate of correspondence between the registered fingerprint pattern and the subsequently entered fingerprint pattern is low, so that fingerprint patterns must be entered many times in order to be recognized correctly.
In this respect, the fingerprint comparison system disclosed in Japanese Patent Publication No. 149776, 1988 requires multiple entries of fingerprint data at the beginning of the finger recognition process. During this process, because only one piece of fingerprint data is registered and stored, and because the rate of correspondence is compared with reference to the single piece of fingerprint data registered, the disadvantage is that the frequency of correspondence between correct fingerprint data entered and the registered fingerprint data is significantly reduced when the accuracy of fingerprint comparison is enhanced. On the other hand, when the accuracy is reduced, the frequency of correspondence may increase, but erroneous recognition of fingerprint data will also increase. Since children's fingerprint patterns change significantly over short periods of time, the fingerprint comparison system disclosed in said Japanese Patent Publication has the disadvantage of failing to accurately recognize the fingerprints of growing children.
Accordingly, it is an object of the present invention to provide a method and apparatus for recognizing a fingerprint pattern whereby a high rate of recognition is achieved by memorizing with learning capability a new fingerprint pattern having a high rate of correspondence in place of a previously stored fingerprint pattern with a low rate of correspondence.

Adaptive dictionary for a fingerprint recognizer


A technique is provided for switching circuitry in a manner which allows the circuit to respond quickly to changes in some critical input signals expected to arrive last. In the preferred embodiment the circuits of this invention are provided in triple logic column form. A circuit will typically include at least two logic columns, each having three portions serially coupled between a high and a low potential source. The middle portion of each logic column is connected to the output node and to receive the critical input signal expected to arrive last, or the input signal with the critical timing requirement. The upper and lower portions of each logic column are connected to receive the remaining input signals, that is those input signals not expected to be changing at the time the critical input signal is received. Thus, the state of the upper and lower portions of the logic column can be "set-up" in advance, in readiness for the critical input condition. Typically, the invention provides three logic columns - - - one logic column for causing the output to follow changes in the state of the critical input signals, one logic column for causing the output to have a state which is the reverse of the state of the critical input signals, and a final logic column for holding the condition of the output constant regardless of changes in the state of the critical input signals.

This invention relates to electronic circuits, and in particular to a type of circuit which allows switching of an output signal quickly upon the arrival of a particular input signal.
In the design of asynchronous circuitry, it is desirable to provide circuits which switch very quickly after arrival of a particular input signal, frequently referred to herein as the "critical" input signal. For example, the designer of a system will often be aware that a particular input signal typically arrives last among a group of input signals. It is therefore desirable to allow the system to react as quickly as possible to that last arriving critical signal so that the next operation to be performed can start as soon as possible.
One well known circuit which lacks this capability, but which is of similar form, is a carry chain circuit such as found in an adder. A carry chain circuit typically consists of an inverter coupled to receive an input carry bit together with suitable logic coupled to the inverter to receive the bits to be added. In a multiple bit adder many such circuits are serially connected to each other, enabling the carry bit to propagate from stage to stage. An example of this circuit is described by Neil H. E. Weste and Kamran Eshraghian in Principles of CMOS VLSI Design - - - A Systems Perspective, Addison-Wesley Publishing Co., Reading, Mass. (1988), pp. 311-314.

System for fast switching of time critical input signals


A crank cover assembly for a bicycle which includes a molded shell member and a molded leaf member which cooperatively encase a forged crank of a bicycle. The molded shell and molded leaf are configured to substantially perform to the outer contour of the forged crank, and each has formed therethrough openings substantially aligned with through openings in the forged crank. The shell and leaf members are coupled together by use of fastening mechanisms such as a catch-tongue joint or a hot-melted joint.

1. Field of the Invention
The present invention relates to a crank cover assembly for a bicycle, and more particularly, to a combination of a pre-molded shell and a pre-molded leaf for covering a bicycle crank.
2. Description of the Related Art
In forming a prior art bicycle crank, the crank is first molded through metal casting or forging. The crank itself is molded to a specified shape, color, and luster. As shown in FIG. 6, crank A having a shaft hole A1 and a threaded hole A2 at longitudinally opposed ends thereof, and having the desired shape is thus formed. To vary the crank color and the overall appearance of the bicycle, a plastic outer coat is formed onto prior art cranks after they have been forged. The plastic outer coat is molded in the mold holding the forged metal crank. In practice, this process is plagued by the following shortcomings:
1. During molding, burn marks are often formed on the shaft hole and the threaded hole of the crank. Great time and effort are expended to individually scrape out those marks. Consequently, the production process is rendered complex and inefficient, and production costs are increased. PA1 2. The crank is first formed by forging before the plastic outer coat is formed thereon by molding. The covering plastic coat may only be formed after the forging process is completed. Thus, production of the entire crank unit consumes much time, and inefficient productivity results. PA1 3. Due to the weight of a metal crank and relatively low strength of plastic in the molding, damage to the plastic outer coat tends to result quite readily during removal of the crank from the mold. PA1 4. If the configuration of the plastic outer coat or crank is to be changed, the mold must also be changed, causing the process to exhaust much time and increase production costs.
In view of the above-mentioned and other shortcomings of conventional plastic coated cranks, the object of the present invention is to provide a process that separates the crank forging and plastic molding processes to prevent the unnecessary consumption of resources and occurrence of errors in the molding process, while providing a convenient means by which to change a given crank's appearance.


A semiconductor integrated circuit device includes: a target circuit whose at least power supply voltage is variable; a power supply voltage providing circuit feeding the target circuit with a power supply voltage; and a minimum energy point monitor circuit detecting an energy-minimizing power supply voltage which minimizes a change in the energy consumed by the target circuit upon a change in the power supply voltage. The power supply voltage delivered by the power supply voltage providing circuit is controlled so as to be equal to the energy-minimizing power supply voltage detected by the minimum energy point monitor circuit.

One of major tasks to be achieved by mobile devices is an increase in the service life of batteries for powering the mobile devices. As one solution of the task, reduction in the energy consumed by the internal circuit of the mobile devices is required. Since the consumed energy is proportional to the electric power consumed by the internal circuit, efforts have been made to research various low-power technologies for reducing the energy consumption. For reducing the power consumed by semiconductor integrated circuits incorporating CMOS logic gates, it is effective to employ a DVFS (Dynamic Voltage and Frequency Scaling) process for controlling the power supply voltage depending on the operating speed required by the circuits. Generally, the power consumed by electronic circuits is monotonously reduced as the power supply voltage is lowered. Based on this general principle, the DVFS process lowers the power supply voltage as much as possible insofar as it can satisfy speed requirements for the circuits for thereby minimizing the electric power consumed by semiconductor integrated circuit devices, as disclosed in Seongsoo Lee and Takayasu Sakurai, "Run-time Voltage Hopping for Low-power Real-time Systems," Design Automation Conference, pp. 806-809, Jun. 5-9, 2000.
Usually, since the consumed energy is lowered as the consumed power is reduced, the energy consumed by a semiconductor integrated circuit device is lowered when the power supply voltage is lowered, as described above. However, when the power supply voltage is lowered, the processing capability of the circuit per unit time is also reduced, and hence a problem arises in that the operating time of the circuit for performing the same process is increased. Inasmuch as the consumed energy is represented by the product of the consumed power and the operating time, the consumed energy may be increased if the rate at which the operating time is increased becomes greater than the rate at which the consumed power is lowered by a reduction in the power supply voltage, as shown in FIG. 1. This tendency manifests itself particularly in a low-voltage range where the rate at which the operating time is increased is high with respect to a reduction in the power supply voltage. FIG. 1 shows an example of the relationship between the power supply voltage and energy consumption of a semiconductor integrated circuit device.
As the dependency of the energy consumed by the semiconductor integrated circuit device upon the power supply voltage has such a tendency, an optimum power supply voltage exists for minimizing the energy consumed by the circuit, as disclosed in David Blaauw and Bo Zhai, "Energy Efficient Design for Subthreshold Voltage Operation," IEEE International Symposium on Circuits and Systems, pp. 21-24, May 2006, for example.
For minimizing the consumed energy by controlling the power supply voltage so as to have an optimum value, the simplest method is to directly measure the energy consumed by the semiconductor integrated circuit device and determine an optimum power supply voltage. According to this method, however, it is necessary to directly measure the energy consumed by the circuit before or while the circuit is operation. In addition, since the optimum voltage varies depending on an environmental factor such as a temperature or the like, it is necessary to re-measure the energy consumed by the circuit each time the environmental factor changes.
Examples of technologies which are relevant to the present invention will be described below.
A technology for determining whether the operating speed of a circuit satisfies a speed requirement or not is disclosed in Japanese Patent Laid-Open Application No. 2002-100967 (JP-A-2002-100967). According to the disclosed technology, a monitor circuit is provided which has power supply voltage vs. delay characteristics equivalent to those of a critical path in a semiconductor integrated circuit device, and the delay characteristics of the monitor circuit are measured to grasp the delay characteristics of the critical path.
It is known that when a semiconductor integrated circuit device is operated under a relatively low power supply voltage, performance variations of the circuitries in the integrated circuit device are increased. Japanese Patent Laid-open Application No. 2003-142598 (JP-A-2003-142598) discloses a technology for compensating for such performance variations. According to the disclosed technology, the difference between the threshold voltages of a PMOS transistor and an NMOS transistor is detected in a semiconductor integrated circuit device having a delay monitor circuit and a main circuit, and a well bias voltage for reducing the difference between the threshold voltages is generated. The generated well bias voltage is applied to the delay monitor circuit and the main circuit.
Detecting a leak current and establishing a source-to-drain voltage to be applied to a MOSFET depending on the detected leak current is disclosed in Japanese Patent Laid-open Application No. 2005-197411 (JP-A-2005-197411), for example.
PCT international publication WO99/12263 discloses that a delay detecting circuit and a substrate bias generating circuit for generating a substrate bias voltage are provided for increasing an operating speed and reducing a leak current in a main circuit, i.e., a target circuit, in a semiconductor integrated circuit device, and the substrate bias voltage is increased or decreased depending on a designed value and a measured delay amount. However, the technology disclosed in WO99/12263 does not control the substrate bias voltage for the purpose of minimizing the consumed energy, i.e., the product of the consumed power and the delay time. Japanese Patent Laid-open Application No. 2003-115750 (JP-A-2003-115750) also discloses a similar semiconductor integrated circuit device configured to equalize the operating speed of a target circuit to a particular reference speed by controlling the power supply voltage. However, the technology disclosed in JP-A-2003-115750 does not control the power supply voltage to minimize the consumed energy.
Japanese Patent Laid-open Application No. 2005-340426 (JP-A-2005-340426) discloses that in order to minimize the power consumption of a target circuit under the condition that the operating speed is constant, a leak current is monitored, and both a power supply voltage and a substrate potential are controlled to keep the ratio of leak power and switching power at a particular value. However, the disclosed technology is problematic in that a complex arrangement is required to control both the power supply voltage and the substrate potential, and the energy consumed by the overall circuit at the time the ratio of leak power and switching power is of a target value cannot be said to be minimum.

Semiconductor integrated circuit device and power supply voltage control system


A decoding circuit applied to a multimedia apparatus is provided. The decoding circuit is for decoding encoded data to generate system information, and includes multiple processing circuits and a determination circuit. The multiple processing circuits individually process the encoded data to generate multiple processed signals, and respectively correspond to multiple bit combinations of a part of the system information. The determination circuit determines the system information according to the multiple processed signals.

Field of the Invention
The invention relates in general to a receiving circuit in a multimedia apparatus, and more particularly to a decoding circuit applied to a multimedia apparatus and an associated decoding method.
Description of the Related Art
In a current Digital Video Broadcast-Satellite-Second Generation (DVB-S2), a receiver decodes a physical layer signaling (PLS) code to obtain system information including 7 bits. The system information mainly includes a modulation scheme, a code rate, a forward error correction data length and whether pilot data is present. In a Digital Video Broadcast-Satellite-Second Generation Extension (DVB-S2X) system, apart from a different encoding method, the system information further includes a bit for distinguishing between DVB-S2 and DVB-S2X. Because the receiver has no way of knowing what the 8-bit system information is before decoding received data, the receiver may encounter errors while decoding the PLS code, and correct information can be obtained only after repeated decoding operations. Further, the probability of decoding errors can be further increased when the signal quality is poor, resulting in degraded performance.

Decoding circuit applied to multimedia apparatus and associated decoding method


A curable polyester molding composition incorporating an elastomeric low profile additive dispersed in voided rubbery particle form throughout the composition is used in association with a compatibilizing agent to form a molded thermoset article having very smooth, light reflective, class A surfaces and having a matrix fracture energy which is comparable to articles formed from similar or identical molding compositions which are free of low profile additives. The low profile additive is an epoxidized elastomer or block copolymer having at least one flexible elastomer block and one monovinyl aromatic block. The compatibilizing agent is a copolymer having a diene polymer backbone which is compatible with the elastomer or the flexible diene block of the low profile additive, with constituents which are compatible or reactive with the polyester being grafted or adducted onto the diene polymer backbone. The compatibilizing agent improves the solubility of the low profile additive in the uncured molding composition to promote good dispersion, to promote and maintain small particle size of the low profile additive, and to enhance compatibility between the cured polyester matrix and the low profile additive, thereby providing a low profile mechanism wherein shrinkage compensation during curing of the composition occurs almost exclusively through voiding of the small tough elastomeric particles of the low profile additive dispersed in the cured polyester matrix.

Because of its relatively low cost and inherently high strength to weight ratio, polyester molding compounds, including sheet molding compounds and thick molding compounds, are being utilized with increasing regularity in the automotive and appliance industry as a replacement for steel. These molding compounds generally comprise unsaturated polyester resin, a crosslinking agent such as styrene, reinforcing fibers such as glass fibers, fillers, a catalyst to enhance curing and various other additives. For applications wherein a smooth Class A surface finish is required, such as for automotive body panels, low profile additives which offset the shrinkage effects of thermosetting polyester molecules during crosslinking are used. These low profile additives counteract the effects of shrinkage to prevent the molding composition from pulling away from the mold surface which would cause waviness, voids or other surface irregularities.
Conventional low profile additives used for reducing shrinkage and for providing improved surface finish for thermosetting resin systems generally fall within one of two major categories. A first general category includes additives which are compatible with the precrosslinked thermosetting system. Examples of low-profile additives which are compatible with styrene crosslinkable unsaturated polyester systems prior to cure include polyvinyl acetate, polycaprolactone, and polyurethane. Compatible low-profile additives, particularly polyvinyl acetate, have been found to achieve excellent low-profile effect, exhibiting low or zero shrinkage and providing good surface appearance. However, such systems usually exhibit significant reductions in mechanical properties such as fracture toughness, tensile strength, modulus and strain to failure and the same is attributable to the morphology which arises from the mechanism by which low-profile effect is achieved. During the early stages of curing for a thermosetting resin system, employing a compatible low-profile additive, as crosslinking proceeds, a high molecular weight polymer network is formed which phase separates from the initial solution and forms spherical microgels or nodules with the initially compatible low-profile additive and unreacted crosslinker and resin forming a continuous phase. As the cure progresses to a more advanced stage, the nodules grow and form a macro-network structure wherein individual nodules are connected to neighboring nodules by comparatively small resin bridges, with the surrounding continuous phase, largely depleted of resin and crosslinker, now comprising mostly the low-profile additive. During the latter stages of the cure, the crosslinked polymer having a macro-network structure begins to shrink creating stresses which are transferred to the continuous, low-profile additive phase, causing the formation of micro-voids or cavitations in the low-profile additive continuous phase. The final cured composition can be described as having a popcorn-like structure or morphology wherein the crosslinked domains comprise nodules, each of which is coated with a thin film of the cavitated low-profile additive and is connected to neighboring nodules by relatively small bridges of crosslinked resin. The greatly reduced continuity of the phases and the ease with which the bridges can be broken explains the severe reduction in mechanical properties.
Thus, while conventional compatible low-profile additives such as polyvinyl acetate are very popular because of their excellent shrinkage compensation effects and because of the high quality surfaces produced therewith, their use is limited by the resulting morphology which leads to reduced toughness and strength.
The second major category of low-profile additives are those additives which are noncompatible with the initial precrosslinked thermosetting resin systems. Examples of noncompatible low-profile additives include polyethylene, polystyrene, polymethylmethacrylate, polyvinyl chloride, butadiene and block copolymers of styrene and butadiene. The noncompatible low-profile additives function differently from the compatible additives and provide an entirely different morphology and mechanism for achieving shrinkage compensation and low profile effect. Noncompatible low-profile additives when used with pre-crosslinked thermosetting resin systems become dispersed as discrete particles within a continuous phase comprising the crosslinker and crosslinkable resin, and ultimately provide a structure wherein the low-profile additive is dispersed as a discrete discontinuous second phase within a continuous crosslinked polymeric matrix. Noncompatible low-profile additives generally have been found to provide better mechanical properties than the compatible low-profile additives, but do not achieve -comparable low-profile effect. Other disadvantages with conventional noncompatible low-profile additives is that because they are noncompatible, i.e. insoluble, with the precured thermosetting solution, the low-profile additive particles can tend to segregate and agglomerate leading to nonuniform properties and surface appearance and paint adhesion problems. Moreover, such additives generally have high molecular weights and consequently form large particles, which, like agglomeration, create surface appearance and paint adhesion problems. Also, the large particles of conventional noncompatible low-profile additives may not be well bonded to the surrounding crosslinked polymer matrix leading to cavitation at the interface between the particles and the matrix, which is less effective for arresting crack propagation than cavitation within the particle.
Thus, while conventional noncompatible low-profile additives achieve a better morphology than conventional compatible low-profile additives, which leads to better mechanical properties, they do not provide very low or zero shrinkage as do the compatible additives. Also, typically they have surface appearance and paint adhesion problems which often preclude their use despite some improvement in mechanical properties.
Accordingly, given the present state of the art, it would be highly desirable to create an additive for thermosetting polymeric composition which counteracts shrinkage during the cure and provides a class A surface finish, while at the same time retaining the good mechanical properties of the polyester.

Low-profile additives for thermosetting polyester compositions


A method and device in combustion plants for solid fuels with a movable grate means for feeding the fuel through the fireplace of the combustion plant, for the control of the fuel feed through the fireplace of the plant. To control that the fed fuel is completely combusted when discharged from the fireplace of the plant the degree of combusted fuel is sensed by a sensor means (9) in a zone (B) at the end of the movable grate means (1) in order to obtain a control signal to the drive means of the grate means.

This invention relates to a method and device at a combustion plant for solid fuels provided with a movable grate means for the control of the fuel feed within the fire space of the combustion plant in order to obtain an efficient and complete combustion of the fuel.
In combustion plants with a movable grate means, on which the fuel is fed through the fire space of the combustion plant, the fuel is fed at a substantially constant velocity into and through the fire space, where the combustion takes place through the supply of primary as well as secondary combustion air, but due to variations in fuel amount fed per unit of time and in the very fuel as to dryness and also combustibility it has been found to involve great problems to obtain such an efficient and complete combustion process in combustion plants with a movable grate means that the fuel is completely burnt out when it leaves the fire space of the plant.
Consequently it is the object of this invention to eliminate this problem and to achieve a method and a device for control of the fuel feed through the fire space of a combustion plant provided with a movable grate means, said space automatically providing for a complete combustion of fed fuel independently of variations in fuel amount fed per unit of time and in the nature of the fed fuel as to dryness and other factors which may influence the combustion negatively.

Device at combustion plants for automatical feeding of fuels within the fireplace of the plant


An anti-skid system for motor vehicles in which the wheel speed is detected by individual transducers and in which two or more transducer signals are alternately periodically connected to a single processing channel for controlling the braking pressure. In order to improve the performance on an inhomogeneous road surface, the connection rhythm of transducers is changed upon the occurrence of a tendency of one of the wheels to lock. According to the invention, the two wheels associated with a single processing channel are the two wheels on the same side of the vehicle, especially the rear wheels of dual rear axle utility vehicles.

The invention relates to anti-skid systems for motor vehicles, sometimes also called anti-wheel lockup systems. More particularly, the invention relates to anti-skid systems which include wheel motion transducers and processing assemblies which use the signals from these transducers for controlling the hydraulic pressure in one or more of the wheel brakes.
A known anti-skid (anti-wheel lockup) system is described in the German Offenlegungsschrift No. 22 20 441. In the system described there, a plurality of transducers is connected sequentially to a processing channel and a brake pressure control unit engaged by the output signals from the processor channel varies the braking pressure of those wheels which are associated with a particular transducer. In the normal situation, the transducers are connected to the processor channel in a periodic sequence but when anyone of the wheels tends to lock up, the periodic switch-over from one transducer to the other is arrested and instead the transducer signal which indicates a tendency to lock is held connected with the processor channel until the tendency to lock up is no longer present. In the known system, the wheel brakes in which the pressure is jointly varied are the wheels mounted on a single axle.
The known system produces a so-called "select low" control. This type of control design is used for utility vehicles and its application results in increases of the braking distance when the road surface is irregular.

Anti-skid control system for motor vehicles


A dedicated power port (DPP) providing 1 Amp (A) or more of current enables a user to charge mobile tablet and communication like devices (TCD) without the use of additional software or circuitry. The DPP is coupled with a multi-port USB powered hub (MPH), the user can simultaneously charge TCDs via the dedicated port while peripheral devices, which are connected to non-dedicated USB ports, continue to function within industry specifications. Thereby addressing a limitation for viable charging solutions of modern day TCDs while simultaneously retaining the functionality and convenience of a MPH, all in one embodiment.

The patent field is related to the charging of portable electronic devices via a multi-port Universal Serial Bus (USB) powered hub. Considering USB properties as discussed in Terry Remple's document Battery Charging Specifications revision 1.1 Apr. 15, 2009, ports use differential data pins, referred to as D+ and D−, to determine if a device is connected to a USB port. In addition, the differential data pins are used to establish and maintain communications or data transfer (hereafter referred to as communications) between peripheral devices and to determine if a port is empty. Typically detection is achieved by utilizing the D+ and D− pins (hereafter, referred to as data pins) together rather than independently. Thus multi-port USB powered hubs provide 0.5 Amp (A) (USB 2.0), or 0.9 A (USB 3.0), of charging current to each port. In contrast, unpowered hubs must be connected to a host apparatus to provide 0.5 A of charging current, which is shared across all ports. Present day mobile tablet and communication like devices (hereafter, referred to as TCD), for example; IPhone, IPad, Slate, Galaxy, Rim, BlackBerry, specify 1 A or more of current on each individual USB port to charge effectively. Previous USB hubs do not satisfy the specification of 1 A or more of charging current, without the intervention of additional software or circuitry. Thus a limitation of readily available charging options which include communications between peripherals (mouse, keyboard, printer) is created. The following is a tabulation of some prior art that is relevant to these limitations:

Dedicated USB power ports coupled with a multi-port USB powered hub


An approach is provided for providing a derivative publication of a publication at one or more services. The publishing service platform processes and/or facilitates a processing of at least one publication to cause, at least in part, a generation of at least one derivative publication. Next, the publishing service platform determines at least one service for publishing the at least one derivative publication. Then, the publishing service platform causes, at least in part, a transmission of the at least one derivative publication to the at least one service for publication.

Service providers and device manufacturers (e.g., wireless, cellular, etc.) are continually challenged to deliver value and convenience to consumers by, for example, providing compelling network services. For example, such network services may include intermediate publication services that enable communication between users and sharing of different published content (e.g., textual data, images, videos, audio files, etc.) between the users. To maximize the exposure of a publication, typical intermediate publication services repeatedly transmit the same publication to more than one network service. Such actions, however, may be perceived as spamming by users, filters, etc., reducing the effectiveness and efficiency of those publication services.

Method and apparatus for providing derivative publications of a publication at one or more services


A reference signal generator includes a voltage reference, an amplifier coupled to the voltage reference, and a precharge circuit coupled to the amplifier. The voltage reference is configured to generate a constant voltage. The amplifier is configured to receive the constant voltage from the voltage reference and generate a regulating primary output signal and a non-regulating secondary output signal. The precharge circuit is configured to charge a noise reduction capacitor with the non-regulating secondary output signal.

Linear voltage regulators are used in many electronic devices to maintain a constant voltage to drive a load. Because the load may vary, the resistance of the regulator varies based on the load so that a constant voltage is produced. One type of linear voltage regulator is a low-dropout (LDO) regulator. LDO regulators are configured to regulate voltage even if the supply voltage is close to the regulated output voltage. LDO regulators include a differential amplifier that drives a power transistor. One input of the differential amplifier is a reference voltage generated by a voltage reference (e.g., a bandgap reference, a Zener diode, etc.). The second input of the differential amplifier is a fraction of the output voltage of the LDO regulator. Thus, the drive voltage to the power transistor changes to regulate the output voltage based on the value of the output voltage itself. In other words, if the output voltage rises relative to the reference voltage, the drive voltage powering the power transistor also changes to maintain an output voltage that remains constant.

Precharge circuit using non-regulating output of an amplifier


A backlash comprises a first rotation member and a second rotation member, each of which is provided rotatably-about the same axis, and which are engageable together in a rotating direction of the members by driving contact between respective radial extension surfaces thereof,and where a backlash gap is provided between the respective radial extension surfaces of the first and the second rotation members to permit fee rotation between the first and second rotation members in a range of the backlash gap in the rotating direction of the members.

The present invention relates to a backlash clutch that realizes a high torque transmission characteristic and free joint mechanism. This invention also relates to a free joint mechanism for a robot comprising the clutch.
Generally, in a clutch mechanism, connection and disconnection for transmitting driving force are achieved by means of a friction mechanism. Such a friction mechanism comprises rotating members that are joined together by frictional function acts between the members to control the on-off action of the clutch. In such a clutch mechanism, using frictional action, it has been difficult to transmit a force when the force is large because slippage arises as the clutch mechanism transmits a driving force.
This phenomenon generates a significant problem when a clutch mechanism is applied to a knee joint of a humanoid robot. Typically, in a humanoid robot, such a joint mechanism provided in the body is driven by controlling actuators to generate objective paths. In particular, an actuator is used to generate high power to the knee joint.
When the humanoid robot rests with a posture shown in FIG. 9, assuming that the weight of the upper part from the articulatio coxae is 60 kgf and the offset length from the articulatio coxae to the knee joint is 10 cm, and that the acceleration of gravity is 9.81 m/s2, the actuator that drives the knee joint must output a high torque, such as 58.86 Nm. Therefore, the knee joint mechanism must have a capability to transmit such a high torque.
In general, the knee joint mechanism is composed of a motor generating high power and reduction gears having a high gear ratio. On the other hand, in a human's walking motion, the knee joint of a leg acts as a free joint when the leg is not engaging the ground (grounded or grounding). It is contemplated that such an action of the knee joint has the following effects;                There is no need to use extra force.        When a human moves a leg forward, the knee of the leg moves freely in accordance with inertial force.        When the leg touches down, an impulsive reaction force that acts on the leg eases up as the leg heads for ground at an adequate angle, naturally.
However, a conventional knee joint mechanism has difficulty realizing a free joint characteristic following a reactive force, where control of the walking motion is performed so as to maintain the knee with a desired angle when the leg is not grounded.
To ensure that the knee joint has such a free moving condition, it is contemplated to incorporate a clutch mechanism into the reduction gears. However, a general clutch mechanism is a friction-type clutch, such as the above-mentioned clutch, and it slips at high torque, such that it is difficult to transmit high torque. Therefore, the clutch mechanism can only be attached to the input shaft side of the reduction gears. Consequently, the need exists for a clutch mechanism for a knee joint of a humanoid robot that can provide output at the shaft side of the reduction gears, as a mechanism that can both transmit high torque and maintain a free moving condition.
It is therefore an object of the present invention to provide a clutch mechanism capable of transmitting high torque and maintaining a free moving condition, and a joint mechanism of a robot comprising such a clutch mechanism. In particular, an object of this clutch mechanism is to realize a walking motion that has the following advantages when it is used as a knee joint:    (1) Transmits a large driving force.    (2) Achieves a free joint.            (a) Does not need to use extra force.        (b) Realizes free motion.        (c) Absorbs an impulsive/reaction force at landing (grounding).

Backlash clutch and joint mechanism for a robot comprising the clutch


A semiconductor device includes an insulating substrate having a semiconductor element mounted thereon; an outer case accommodating the insulating substrate; and a metallic terminal bar disposed above the insulating substrate and fixed to side walls of the outer case at both ends thereof. Each of both ends of the terminal bar at a position close to the side wall of the outer case at a surface on an opposite side to a surface facing the insulating substrate is provided with a pressed groove.

A semiconductor device typically has a structure in which a semiconductor element and an insulating substrate mounted on a metallic base plate for heat radiation are wire bonded together and those components are covered by an outer case.
In the widely used type of the main shape of the outer case, outer terminals of the same polarity are provided at two locations on the opposing two sides, among the four circumferential sides of the outer case, and the external terminals on the opposing sides are connected by a terminal bar. A terminal section for connecting to the insulating substrate is formed at the terminal bar.
When a semiconductor device is manufactured using such an outer case, first, the insulating substrate with a semiconductor element mounted thereon is positioned in the outer case, and the metallic base plate carrying the insulating substrate is attached to the outer case with an adhesive. Then, the terminal section of the terminal bar provided at the outer case and the insulating substrate are soldered together by paste soldering.
In the conventional semiconductor device, a pair of positive and negative DC input terminals is arranged, so that same polarities face each other at two opposing side of a package accommodating a semiconductor element (Patent Document 1).
Patent Document 1: Japanese Patent Application Publication No. H7-111310
When the insulating substrate with the semiconductor element mounted thereon is accommodated in the outer case and the terminal section of the terminal bar and the insulating substrate are soldered together, the metallic terminal bar undergoes thermal expansion due to heating that accompanies soldering.
In this case, since both ends of the terminal bar are fixed, the terminal bar that is flat at a normal temperature is deformed by thermal expansion and a clearance (gap) can occur between the terminal section of the terminal bar and the insulating substrate. Problems encountered when the clearance occurs between the terminal section of the terminal bar and the insulating substrate include degradation of solderability and occurrence of connection defects.

Semiconductor device and semiconductor device manufacturing method


A hydraulic valve is provided that includes an interior spool and a surrounding cage. A supply port and a return port are connected to the cage and the interior of the cage is in fluid communication with a control port. The interior spool is positioned between an on and off position using a solenoid and a spring. In the off position, slots in the spool and cage align to place the return port in fluid communication with the interior of the spool. Conversely, in the on position, different slots in the spool and cage align to place the supply port in fluid communication with the interior of the spool.

The present invention generally relates to an improved valve. More particularly, the present invention relates to a valve having a large valve capacity and electro-hydraulic proportional pressure reducing and relieving abilities.
There are valves with stepped bores such as those shown in U.S. Pat. Nos. 5,876,185 and 6,125,886. In these patents the push is reduced by the smaller feedback area from a differential area formed by the stepped bore. However, the flow and response of these valves is limited due to flow forces that tend to shut the valve. In various applications ranging from pump controls to pilot operation of a larger direction control spool to even a direct cylinder actuation, the size of the application is determined by the flow capacity of the valve.

Electro-hydraulic pressure reducing and relieving valve with flow force control for large flow capacity


The invention relates to a computer-implemented method for handling revocation statuses of credentials, the method including: an issuing computer transmitting a public key to user and verifying computers, a revocation computer sending revocation parameters to user and verifying computer devices, issuing credentials to a user computer by an issuing computer, verifying issued credentials by the user computer, transmitting updated revocation information to the revocation computer by the verifying computer, updating provisional revocation status information by the revocation computer, updating revocation status information by the revocation computer, transmitting updated revocation information to a revocation computer by a verifying computer, updating provisional revocation status information by the revocation computer, transmitting updated revocation status information to the user and verifying computers by the revocation computer, creating a presentation token by the user computer, transmitting the presentation token to a verifying computer, and verifying the presentation token by the verifying computer.

Credentials, and more precisely cryptographic credentials, are commonly known and used in cryptography-based applications, e.g. cryptographically secured exchange of data between computer systems or devices, to certify information. A credential holder, who is requested to provide information, may provide the requested information and use a credential to prove that the provided information is correct and trustable. A cryptographic credential is essentially a certificate generated via a cryptographic process. Such a credential is issued by a credential issuing entity to a credential holder after the information to be certified by the credential has been appropriately verified. The information in question is cryptographically encoded in the credential to certify the correctness of said information. In particular, the information to be certified may be represented by some value or function which is then encoded in the credential via a cryptographic algorithm. When requested by a verifying entity to provide certain information and to prove the same, the credential holder may provide the requested information and use a credential, in which this information is encoded, to make a suitable proof to the verifying entity, via various cryptographic proof protocols.
Sometimes such credentials need to be revoked, e.g. when the secret cryptographic keys to which the credential is bound have been exposed or the credential holder lost the right to possess the credential.
Revocation tasks are carried out by revocation authorities. The revocation authority creates and maintains a revocation list with revocation statuses of credentials. This list may be a whitelists or a blacklist, listing all the credentials which are valid or invalid, respectively. A credential becomes invalid by revoking the same. The revocation is performed through a revocation handle, i.e. a dedicated unique identifier that the issuing entity embeds in each issued credential. When a credential is to be revoked, a request for revocation must be provided to the revocation authority. Upon receiving a valid request for revocation of a credential, the revocation authority deletes or adds the respective credential from or to the revocation list, depending on whether it is a whitelists or a blacklist.
In order to prove that a credential used for certifying information is valid, i.e. not revoked, membership or non-membership of the credential's revocation handle in the revocation authority's whitelists or blacklist has to be proven.

International Business Machines Corporation


To display a window for displaying auxiliary information near a window for displaying main information. When a drag operation is performed to move a multiuser window to a predetermined position and display there, if the distance of the multiuser window to the main window when the drag operation is cleared is within reference value LR and the distance of the top side of the multiuser window to the top side of the main window is within reference value HR, then the multiuser window is automatically moved such that the side of the multiuser window comes in contact with the side of the main window and the top end of the multiuser window comes in alignment with the top end of the main window on a horizontal line.

1. Field of the Invention
The present invention generally relates to an image display processing apparatus, an image display processing method, and an information providing medium and, more particularly, to an image display processing apparatus, an image display processing method, and an information providing medium that allow efficient arrangement of a three-dimensional virtual reality space image and a plurality of windows for displaying accompanying information associated with this space by effective use of a display screen.
2. Description of Related Art
A cyberspace service named Habitat (trademark) is known in the so-called personal computer communications services such as NIFTY-Serve (trademark) of Japan and CompuServe (trademark) of US in which a plurality of users connect their personal computers via modems and public telephone network to the host computers installed at the centers of the services to access them in predetermined protocols. Development of Habitat started in 1985 by Lucas Film of the US, operated by Quantum Link, one of US commercial networks, for about three years. Then, Habitat started its service in NIFTY-Serve as Fujitsu Habitat (trademark) in February 1990. In Habitat, users can send their alter egos called avatars (the incarnation of a god figuring in the Hindu mythology) into a virtual city called Populopolis drawn by two-dimensional graphics to have a chat (namely, a realtime conversation based on text entered and displayed) with each other. For further details of Habitat, refer to the Japanese translation of "Cyberspace: First Steps," Michael Benedikt, ed., 1991, MIT Press Cambridge, Mass., ISBN0-262-02327-X, the translation being published Mar. 20, 1994, by NTT Publishing, ISBN4-87188-265-9C0010, pp. 282-307.
In order to implement the above-mentioned cyberspace system by use of the infrastructure of the Internet through which information can be transferred all over the world, standardization of a three-dimensional graphics description language called VRML (Virtual Reality Modeling Language) is proceeding.
In WWW (World Wide Web) of the Internet, document data can be described in HTML (Hyper Text Markup Language) and the resultant HTML file can be stored in a WWW server. This HTML file can be transferred on demand by a client terminal and can be displayed by use of the HTML browser of that client terminal.
Like this HTML file, three-dimensional graphics data can be described in VRML and the resultant VRML file can be stored in a WWW server. This VRML file can be transferred on demand by a client terminal and can be displayed by use of the VRML browser of that client terminal.
If, when a user who uses (mainly looks at) a three-dimensional virtual reality space through the above-mentioned VRML browser for example and is moving his or her avatar, meets an avatar of another user, the user can chat with another user.
For example, a chat service called Worlds Chat (trademark) developed by Worlds Inc. of US and made commercially available from April 1995 is used to make chat. This Worlds Chat supports chat in a three-dimensional virtual reality space based on the company's own standard, allowing a user to freely move in a virtual space of a fictitious space station to chat realtime in the form of text with another user in the space station.
In order to move avatars for enjoyment in such a three-dimensional virtual reality space, as many windows as possible must be displayed.
In the ordinary system, however, the display positions of windows are arranged to predetermined positions by a user with a mouse or the like, so that many windows cannot be efficiently displayed in a single limited screen. If a plurality of windows are displayed in such a single limited screen, the displayed windows overlap each other, thereby disabling the user to recognize an image of a window hidden under another.

Image display processing apparatus that automatically changes position of sub-window relative to main window depending on distance at watch sub window is commanded to be displayed


The invention relates to a vacuum pump, in particular a vane pump, having a pump housing in which an intake chamber is provided, and a pump housing opening which feeds into the intake chamber, wherein an intake check valve is arranged in the pump housing opening and communicates with the atmosphere or feeds into an external vacuum chamber, with the intake check valve being accommodated in a pot-shaped valve housing, and with the pot-shaped valve housing having a housing bottom and a housing jacket, wherein the housing bottom is connectable to the housing jacket and the housing bottom can be snapped onto the housing jacket.

The invention relates to a vacuum pump, in particular a vane pump, having a pump housing in which an intake chamber is provided, and a pump housing opening which feeds into the intake chamber, wherein an intake check valve is arranged in the pump housing opening and communicates with the atmosphere or feeds into an external vacuum chamber, with the intake check valve being accommodated in a pot-shaped valve housing, and with the pot-shaped valve housing having a housing bottom and a housing jacket.
WO 2008/009 251 A1 discloses a vacuum pump having such a structure. This vacuum pump draws air from a vacuum chamber, for example a brake booster, with the intake chamber being formed within the vacuum pump by vanes. To prevent a return flow, the vacuum pump is equipped with an intake check valve which is arranged in a pump housing opening. This intake check valve has a sleeve-like configuration and has a pot-shaped valve housing with a housing jacket and a housing bottom, with the housing bottom being inserted into the pump housing of the vacuum pump. A vacuum hose for example is placed upon the free end of the intake check valve which protrudes from the pump housing of the vacuum pump. The intake check valve is sealed in the pump housing opening for example by sealing elements, for example O-rings. In the afore-mentioned known vacuum pump, a support body is inserted into the housing jacket of the intake check valve for holding the valve body.


A console assembly for use in an automotive vehicle body passenger compartment is disclosed. The assembly includes a housing member interposed between a pair of seats in the vehicle, an armrest member and a bottom member pivotally secured to the housing member. The armrest member and bottom member pivot from a first position defining an auxiliary seat to a second position defining a console assembly in the vehicle.

1. Field of the Invention
The present invention relates generally to a console for use in automotive vehicle front seating arrangements. More particularly, the present invention relates to a console which is selectively convertible between a console assembly and an auxiliary passenger seat disposed between the driver and primary passenger seats of the vehicle.
2. Disclosure Information
It is well known in the automobile body arts to provide for the mounting of trays or other receptacles in the passenger compartment of an automobile to permit relatively stable support of items of food and drink and other small articles. Such trays are typically mounted to a floor console such as shown in U.S. Pat. No. 4,453,759, assigned to the assignee of the present invention. Although the console provides for the storage of articles, the console interrupts the continuity of the front seat resulting in the driver seat being spaced apart and remote from the primary passenger seat. To provide for a second or auxiliary passenger front seat, a continuous bench-type seat extending across the entire width of the vehicle or a split-type seat wherein the two passenger seat portions form one continuous portion of the split seat arrangement have been utilized. However, in both of these seating arrangements, it is not possible to provide for a functional console such as described above.
U.S. Pat. No. 4,685,729 proposes a console assembly which is convertible between a compartmentalized console extending from the front seat toward the vehicle dashboard and a second passenger seat position between the driver seat and the primary passenger seat. The console of the '729 patent utilizes a reversible motor driven lead screw attached to a track associated with the console frame which selectively extends and retracks the console frame relative to the seating frame to provide a console. In this manner, an auxiliary or second passenger seat is provided while still providing for a console assembly. However, the use of a motor driven console assembly often increases the cost of the console assembly, the weight of the assembly, and decreases the operating efficiency of the system. Therefore, it would be advantageous to provide a selectively convertible console assembly/auxiliary passenger seat combination which overcomes these deficiencies in the prior art.

Convertible floor console and auxiliary seat for an automotive vehicle


Processing techniques for processing high-dielectric-constant material are provided to allow for the formation of an electronic device (10) which comprises a inner electrode (24), a high-dielectric-constant layer (28), and an outer electrode (30). High-dielectric-constant layer (28) is subjected to ultraviolet radiation in an oxygen ozone ambient to eliminate various undesirable hydroxide and carbonate compounds. Layer (28) is further subjected to high pressure isotropic reactive ion etches prior to the deposition of layer (30). The interface between layer (28) and layer (30) is exposed to reactive fluorine and low pressure plasma to improve the fair electric properties and leakage currents associated with layer (28).

The increasing need for high density capacitive structures such as dynamic random access memory cells has led to the use of high-dielectric-constant materials such as barium strontium titanate and the like, whose high permittivity allows for extremely high capacitive storage capability in a very small area. These high-dielectric-constant materials are usually applied using metal organic chemical vapor deposition techniques, which create significant problems due to the contamination of water and hydrocarbon materials on the surface of the high-dielectric-constant materials and in the bulk of the high-dielectric-constant material. These contaminants can greatly degrade the performance of devices made using the high-dielectric-constant materials. In most cases, processing techniques that are used to deposit and clean dielectric materials do not work well with these high-dielectric-constant materials due to their peculiar susceptibility to contamination from water and hydrocarbons.

Processing methods for high-dielectric-constant materials