A method of passing a cryptographic key that allows recovery of the key by a third party by generating a first random number by a first user; generating xe2x80x9ckey1xe2x80x9d by the first user; generating a second random number xe2x80x9ck2axe2x80x9d by the first user; computing xe2x80x9cy1xe2x80x9d by the first user; computing xe2x80x9cy2xe2x80x9d by the first user; computing xe2x80x9cr1xe2x80x9d by the first user; computing xe2x80x9czxe2x80x9d by the first user; computing xe2x80x9csxe2x80x9d by the first user; computing xe2x80x9cGxe2x80x9d by the first user; passing (G,z,r1,s) from the first user to the second user; receiving xe2x80x9cYxe2x80x9d by the second user; computing xe2x80x9cTxe2x80x9d by the second user; computing xe2x80x9cy1xe2x80x9d by the second user; computing xe2x80x9ck1axe2x80x9d by the second user; computing xe2x80x9ckey1xe2x80x9d by the second user; intercepting, by a third party, (G,z,r1,s) transmitted from the first user to the second user; presenting xe2x80x9cGxe2x80x9d and xe2x80x9cz,xe2x80x9d by the third party, to a key-escrow agent; computing xe2x80x9cy2xe2x80x9d by the key-escrow agent; computing xe2x80x9ckey2xe2x80x9d by the key-escrow agent, where key2=key1; returning xe2x80x9ckeyxe2x80x9d from the key-escrow agent to the third party if the third party is authorized to receive xe2x80x9ckey2xe2x80x9d; and using xe2x80x9ckey2xe2x80x9d by the authorized third party, to decrypt an encrypted message sent between the first user and the second user which was encrypted using xe2x80x9ckey1.xe2x80x9d

This invention relates to cryptography and, more particularly, to a method of passing a cryptographic key so that an authorized third party may gain access to the key.
Practitioners in the field of cryptography first occupied themselves with trying to find a mathematical function that an adversary could not determine. Theoretically, such functions exist (e.g., scramblers). However, such devices are not secure because such devices are easily reverse-engineered in order to determine the cryptographic function.
The notion that hardware could be kept secret was abandoned. An idea was then introduced to couple a secret random entity (i.e., a cryptographic key) to the hardware in order to keep communications secure even if the hardware was reverse engineered. In this scenario, each user received a copy of the hardware. Each pair, or group, of users who wished to communicate securely would decide on a cryptographic key. For convenience, the process was such that the cryptographic key could be used for both encryption and decryption hence the terms xe2x80x9csymmetric-keyxe2x80x9d and xe2x80x9csymmetric-key cryptography.xe2x80x9d The cryptographic key decided upon was then securely given to each party to the communication. Typically, this meant that the cryptographic key had to be securely delivered to each user. Such a key distribution system works well with a closed group of users consisting of a small number, but it becomes unwieldy when the number of users is large. Also, if the symmetric-key is compromised, the communications of everyone using the key is compromised. Therefore, a need arose for a solution to the key distribution problem. Public-key cryptography offers such a solution.
U.S. Pat. No. 4,200,770, entitled xe2x80x9cCRYPTOGRAPHIC APPARATUS AND METHOD,xe2x80x9d is a patent on the first publicly disclosed method of arriving at a secret symmetric-key between two users using a non-secure channel. U.S. Pat. No. 4,200,770, commonly referred to as the Diffie-Hellman key exchange method, is hereby incorporated by reference into the specification of the present invention. In this key exchange method, each user generates a random number that is kept secret. Each user uses their secret as an exponent to a non-secret base that is shared in common with the other user (i.e., exponentiation). Each user modulo reduces their exponentiation by a non-secret number that is shared in common with the other user. Each user transmits their modulo reduced exponentiation to the other user. Each user raises the exponentiation they receive to their secret, and each user modulo reduces this second exponentiation by the same shared modulus. This results in each user computing the same value that is known only by them. In effect, each user conceals their secret (the exponent) in a mathematical function that is believed to be unsolvable for large values (i.e., modulo reduced exponentiation). Each user transmits their buried secret to the other user. Each user raises the other user""s buried secret to their secret. After a final modulo reduction, each user is in possession of the same symmetric key that an adversary cannot mathematically determine. To mathematically determine the key, an adversary must be able to determine the discreet logarithm of what at least one user transmitted, hence the name xe2x80x9cdiscreet logarithm problem.xe2x80x9d This problem is considered unsolvable, or intractable, for large values.
Here, xe2x80x9ckey exchangexe2x80x9d is defined as each user participating in the creation of a key. Neither participant knows in advance what the final key will be. This differs from a xe2x80x9ckey passxe2x80x9d which entails a single user creating a key and passing it securely to the other user. The receiving user recovers, or decrypts, the key but does not alter the key in any other way.
Along with the advantages of public-key cryptography there are some disadvantages. That is, public-key cryptography involves many more steps than does symmetric-key cryptography. This means that public-key cryptography is slow compared to symmetric-key cryptography. Also, a user using the Diffie-Hellman key exchange method cannot be sure that the other user is who they claim to be. Therefore, a need arose for a method of digitally signing an electronic communication.
Taher ElGamal, in a paper entitled xe2x80x9cA Public Key Cryptosystem and Signature Scheme Based on Discreet Logarithms,xe2x80x9d IEEE Transactions on Information Theory, Vol. IT-31, No. 4, July 1985, pp. 469-472, proposed an encryption method and a digital signature method that incorporates the strength of the Diffie Hellman key-exchange method (i.e., the discreet logarithm problem). ElGamal""s signature method has received more attention than has his encryption method. ElGamal""s signature method is based on Euler""s Totient function. In this method, a first user generates a long term secret exponent and xe2x80x9chidesxe2x80x9d it in a modulo reduced exponentiation using a publicly known base and modulus. The user binds the result to his or her identity by a certifying authority. Next, the first user computes a number using a certain parameter (e.g. a message), his long-term secret, and a second per-message secret. These two secrets are known only by the first user. The first user sends the computed number, the modulo reduced exponentiation of the xe2x80x9cper-message secret,xe2x80x9d and the message to the second user. The second user uses the numbers, the message, and the certified modulo reduced exponentiation to verify a mathematical relationship. If the relationship is verified then the second user is assured that the message came from the first user. This may not be true if the long-term secret is known by an adversary. ElGamal""s method creates a digital signature. The computations involved here are mathematically complex and time consuming. The resulting signature is large and requires a large amount of bandwidth in order to transmit it.
In a paper entitled xe2x80x9cEfficient Identification and Signatures for Smart Cards,xe2x80x9d Advances in Cryptologyxe2x80x94Proceedings of CRYPTO ""89, Lecture Notes in Computer Science, No. 435, Springer-Verlag, New York, 1990, pp. 239-251, Claus Schnorr developed a variation of ElGamal""s digital signature that is simpler to compute and takes up less bandwidth than ElGamal""s digital signature. Schnorr uses a subgroup of the group used by ElGamal. The subgroup Schnorr uses is smaller than the group used by ElGamal. The result is a faster, less compute intensive method that requires fewer bits to be transmitted. Schnorr""s method was patented as U.S. Pat. No. 4,995,082 entitled xe2x80x9cMETHOD FOR IDENTIFYING SUBSCRIBERS AND FOR GENERATING AND VERIFYING ELECTRONIC SIGNATURES IN A DATA EXCHANGE SYSTEM.xe2x80x9d U.S. Pat. No. 4,995,082 is hereby incorporated by reference into the specification of the present invention.
The National Institute of Standards and Technology (NIST) published Federal Information Process Standard (FIPS) Publication No. 186 entitled xe2x80x9cDigital Signature Standardxe2x80x9d (DSS). FIPS PUB 186 is hereby incorporated by reference into the specification of the present invention. The DSS discloses a method of generating a digital signature that is secure, reasonably easy to generate and verify, and bandwidth efficient. U.S. Pat. No. 5,231,668, entitled xe2x80x9cDigital Signature Algorithm,xe2x80x9d (DSA) embodies DSS. U.S. Pat. No. 5,231,668 is hereby incorporated by reference into the specification of the present invention. DSA is a bandwidth efficient variant of ElGamal. DSA employs the computations of ElGamal in a subgroup of the group used by ElGamal. The subgroup used in DSA is smaller than the group used by ElGamal.
In a paper entitled xe2x80x9cMessage Recovery for Signature Schemes Based on the Discreet Logarithm Problem,xe2x80x9d Pre-proceedings of Eurocrypt ""94, pp. 175-190, Ms. Nyberg and Mr. Rueppel developed a variant of DSA that eliminates the need to send the message while allowing the recovery of the message from what is transmitted. Nyberg and Rueppel also propose a key exchange method that is based on DSA and the Diffie-Hellman key exchange method. The steps of their message-recovery method is as follows:
a) a first user generates two random integers xe2x80x9ck1xe2x80x9d and xe2x80x9ck2,xe2x80x9d where xe2x80x9ck1xe2x80x9d and xe2x80x9ck2xe2x80x9d are each less than a prime integer xe2x80x9cq,xe2x80x9d where xe2x80x9cqxe2x80x9d divides evenly into xe2x80x9cpxe2x88x921,xe2x80x9d where xe2x80x9cpxe2x80x9d is a prime integer greater than xe2x80x9cqxe2x80x9d;
b) the first user computes xe2x80x9cr1=g{circumflex over ( )}(k2xe2x88x92k1) mod p,xe2x80x9d where xe2x80x9c{circumflex over ( )}xe2x80x9d denotes exponentiation, and where the base xe2x80x9cgxe2x80x9d has order xe2x80x9cqxe2x80x9d in the integers modulo xe2x80x9cpxe2x80x9d;
c) the first user computes xe2x80x9cr2=r1 mod qxe2x80x9d;
d) the first user solves the equation xe2x80x9c1=((xe2x88x92x1*r2)+(k1*s)) mod q,xe2x80x9d for xe2x80x9csxe2x80x9d, where xe2x80x9cx1xe2x80x9d is the first user""s long-term secret, and where xe2x80x9c*xe2x80x9d denotes multiplication;
e) the first user transmits (r1, s) to a second user;
f) the second user computes xe2x80x9cr2=r1 mod qxe2x80x9d;
g) the second user computes xe2x80x9ct=(1/s) mod q,xe2x80x9d and xe2x80x9c(((g{circumflex over ( )}x1){circumflex over ( )}r2)*g){circumflex over ( )}t mod p,xe2x80x9d where this last computation should equal xe2x80x9cg{circumflex over ( )}k1 mod pxe2x80x9d;
h) the second user then computes xe2x80x9c(g{circumflex over ( )}k2)*r1 mod pxe2x80x9d, where the result should equal xe2x80x9cg{circumflex over ( )}k2 mod pxe2x80x9d;
i) the second user computes xe2x80x9ckey=(g{circumflex over ( )}k2){circumflex over ( )}x2 mod p,xe2x80x9d where xe2x80x9cx2xe2x80x9d is the second user""s long-term secret; and
j) the second user sends xe2x80x9cg{circumflex over ( )}x2 mod pxe2x80x9d to the first user; and
k) the first user computes xe2x80x9ckey=((g{circumflex over ( )}x2) mod p){circumflex over ( )}k2 mod p.xe2x80x9d
Note that the equation in step (d) is the same as the equation in DSA with the value xe2x80x9czxe2x80x9d in DSA set to one. The pair xe2x80x9c(r1, s)xe2x80x9d embodies not just the signature of a message, but includes the message itself. The second user recovers the message and verifies the source as the first user. Both users will be able to compute xe2x80x9ckeyxe2x80x9d only if they know their respective long term secrets.
The message-recovery method of Nyberg and Rueppel does not allow the recovery of a key by an authorized third party and it requires the transmission of the long value xe2x80x9cr1.xe2x80x9d
In a paper entitled xe2x80x9cMETA-ElGamal Signature Schemes,xe2x80x9d 2nd ACM Conference on Computer and Communications Security, 1994, Messrs. Horster, Petersen, and Michels disclose a general equation (i.e., A=(xB+kC) mod q) for the three DSS parameters xe2x80x9cmxe2x80x9d, xe2x80x9crxe2x80x9d, and xe2x80x9cs.xe2x80x9d The parameter xe2x80x9cmxe2x80x9d denotes the hash of a message to be signed, the signer""s long-term secret xe2x80x9cx,xe2x80x9d and the signer""s per-signature secret xe2x80x9ck.xe2x80x9d The parameter xe2x80x9crxe2x80x9d is computed as xe2x80x9cr=(g{circumflex over ( )}k mod p) mod q.xe2x80x9d Horster et al. disclose six different signature equations that were generated by six different ways of substituting (m,r,s) for (A,B,C). The six different signature equations are as follows:
m=xAr+ks mod q, where A=m, B=r, and C=s;
m=xAs+kr mod q, where A=m, B=s, and C=r;
s=xAr+km mod q, where A=s, B=r, and C=m;
s=xAm+kr mod q, where A=s, B=m, and C=r;
r=xAs+km mod q, where A=r, B=s, and C=m; and
r=xAm+ks mod q, where A=r, B=m, and C=s.
Horster et al. also disclose a general verification equation (i.e., xcex1A=(yA)BrC mod p) for the general signature equation. The six different verification equations that correspond to the six signature equations above are as follows:
xcex1m=(yA)rrs mod p, where A=m, B=r, and C=s;
xcex1m=(yA)srr mod p, where A=m, B=s, and C=r;
xcex1s=(yA)rrm mod p, where A=s, B=r, and C=m;
xcex1s=(yA)mrr mod p, where A=s, B=m, and C=r;
xcex1r=(yA)srm mod p, where A=r, B=s, and C=m; and
xcex1r=(yA)mrs mod p, where A=r, B=m, and C=s.
The present invention improves upon these general equations by including a method of recovering the key by a third party.
A cryptographic method that allows third party access to an encrypted communication has been proposed. Such a method is called xe2x80x9ckey escrow.xe2x80x9d Essentially, key escrow is a cryptographic method that allows a third party (e.g., a law enforcement activity) access to the key used by a first user and a second user when the third party is authorized to do so (e.g., when criminal activity is suspected and a search warrant is obtained). U.S. Pat. Appl. No. 08/528,966, entitled xe2x80x9cA DEVICE FOR AND METHOD OF CRYPTOGRAPHY THAT ALLOWS THIRD PARTY ACCESS, now U.S. Pat. No. 5,631,961,xe2x80x9d is an example of such a method. U.S. Pat. Appl. No. 08/528,966 is hereby incorporated by reference into the specification of the present invention. One of the problems with the proposed key-escrow methods is that the key escrow aspect of the pass or exchange is independent of the key establishment process. This separation makes the method vulnerable to attacks that would not be possible if the key escrow were made an integral part of key establishment process. The present invention discloses a method that allows a first user to pass a cryptographic key to a second user which incorporates a key-escrow feature.
It is an object of the present invention to pass a cryptographic key from a first user to a second user so that an authorized third party may gain access to the key.
It is another object of the present invention to pass a cryptographic key from a first user to a second user in a certified and bandwidth efficient manner so that an authorized third party may gain access to the key.
It is another object of the present invention to exchange a cryptographic key between a first user and a second user so that an authorized third party may gain access to the key.
It is another object of the present invention to exchange a cryptographic key between a first user and a second user in a certified and bandwidth efficient manner so that an authorized third party may gain access to the key.
The present invention is a method of passing a key between a first user and a second user in a manner that allows an authorized third party to gain access to the key.
In the present invention, key recovery is embedded into the key pass method. Key recovery allows an authorized third party to recover the key with the help of an escrow agent.
The steps of the present invention are as follows:
a) a first user generates a first random number xe2x80x9ck1axe2x80x9d;
b) the first user generates xe2x80x9ckey1=m(k1a)xe2x80x9d;
c) the first user generates a second random number xe2x80x9ck2axe2x80x9d;
d) the first user computes xe2x80x9cy1=m(hp2(k2a))xe2x80x9d;
e) the first user computes xe2x80x9cy2=m(Hp(k1a));
f) the first user computes xe2x80x9cr1=f(y1,k1a)xe2x80x9d;
g) the first user computes xe2x80x9cz=f(y2, key1)xe2x80x9d;
h) the first user computes xe2x80x9cs=(1/k2a) ((k1a*z)+(xa*r1)) mod q,xe2x80x9d;
i) the first user computes xe2x80x9cG=g{circumflex over ( )}k1a mod pxe2x80x9d;
j) the first user passes (G,z,r1,s) to the second user;
k) the second user receives xe2x80x9cY=g{circumflex over ( )}xa mod pxe2x80x9d from, for example, an independent directory/certificate server;
l) the second user computes xe2x80x9cT=(Y{circumflex over ( )}r1*G{circumflex over ( )}z){circumflex over ( )}((1/s) mod q) mod pxe2x80x9d;
m) the second user computes xe2x80x9cy1=m(ha2(T))xe2x80x9d;
n) the second user computes xe2x80x9ck1a=(fxe2x88x921) (y1, r1),xe2x80x9d;
o) the second user computes xe2x80x9ckey1=m(k1a)xe2x80x9d;
p) a third party intercepts (G,z,r1,s) transmitted from the first user to the second user;
q) the third party presents xe2x80x9cGxe2x80x9d and xe2x80x9czxe2x80x9d to a key-escrow agent;
r) the key-escrow agent computes xe2x80x9cy2=m(Hs(G))xe2x80x9d:
s) the key-escrow agent computes xe2x80x9ckey2=(fxe2x88x921)(y2, z), where key2=key1xe2x80x9d; and
t) the key escrow agent returns xe2x80x9ckey2xe2x80x9d to the third party if the third party is authorized to receive xe2x80x9ckey2xe2x80x9d; and
u) the third party uses xe2x80x9ckey2xe2x80x9d to decrypt an encrypted message sent between the first user and the second user which was encrypted using xe2x80x9ckey1.xe2x80x9d
In an alternate embodiment, steps may be added to the method above that would allow the second user to determine if the first user is complying with escrow aspects of the method. In the method above, the second user is given or computes terms that may be used to generate other terms transmitted from the first user to the second user. The second user may compute certain terms transmitted from the first user to the second user and compare these computed terms to the terms transmitted. The method continues if the compared terms are the same and is halted otherwise. The following five steps may be inserted after step (o) above:
o1) the second user computes xe2x80x9cy2=m(Hp(k1a))xe2x80x9d;
o2) the second user computes xe2x80x9cz=f(y2, key);
o3) the second user compares xe2x80x9czxe2x80x9d computed in step (o2) to xe2x80x9czxe2x80x9d received from the first user, if they match, the method continues, otherwise the method is halted;
o4) the second user computes xe2x80x9cG=g{circumflex over ( )}k1a mod pxe2x80x9d; and
o5) the second user compares xe2x80x9cGxe2x80x9d computed in step (o4) to xe2x80x9cGxe2x80x9d received from the first user, if they match, the method continues, otherwise the method is halted.
In a second alternate embodiment, xe2x80x9czxe2x80x9d may be formed using a portion of xe2x80x9ckey1xe2x80x9d instead of all of xe2x80x9ckey1xe2x80x9d. Also, more than one key-escrow agent may be employed, and many different scenarios are possible with respect to what these escrow agents hold. Additional certification and identification schemes may be incorporated into the present invention if desired.
A third alternate embodiment of the present invention is a key exchange method that allows an authorized third party to obtain a key exchanged between a first user and a second user. In the key-exchange method, a first user and a second user each generate and pass their own key as above to the other user. That is, the first user generates a key and passes it to the second user while the second user generates a different key and passes it to the first user. Each user then combines the two keys in an agreed upon fashion to arrive at the final key to be used to encrypt messages between the users. That is, each user combines the key that they generated and passed to the other user to the key that was passed to them by the other user. The authorized third party would then have to intercept the two key messages transmitted between the users, recover both keys, and combine them in the same manner the users did.
The preferred embodiment of the present invention results in a bandwidth efficient method of passing a key from a first user to a second user while allowing an authorized third party access to the key. The present invention is less susceptible to attack than methods that separate key establishment from key escrow.

Method of passing a cryptographic key that allows third party access to the key

The United States of America as represented by the National Security Agency


A processing apparatus for a lithographic printing plate, which has a photosensitive material coated thereon and has an image formed with an FM screen or a high definition AM screen, by a developing part and a rinsing part in this order, in which a concavo-convex part or grooves are provided on a lower roller of a pair of feeding roller at a feeding port of the rinsing part.

1. Technical Field of the Invention
The present invention relates to such a processing apparatus for a lithographic printing plate that is particularly effective for processing a lithographic printing plate having an image formed with a high definition AM screen or an FM screen. More specifically, the invention relates to a processing apparatus for a lithographic printing plate containing a photothermal conversion agent and being exposed with laser in a heat mode.
2. Description of the Related Art
In general, a photosensitive lithographic printing plate is developed with a photosensitive lithographic processing apparatus (hereinafter, sometimes referred to as a printing plate processor). The developing process in the printing plate processor is carried out in such a manner that a photosensitive lithographic printing plate having an image recorded therein is immersed in a developing solution retained in a developing bath by conveying the printing plate to the developing bath, and the photosensitive layer in an area having no image formed of the photosensitive lithographic printing plate is removed by a scrubbing means, such as a rotating brush roller, provided in the developing solution. In the printing plate processor, the photosensitive lithographic printing plate having been subjected to the developing step with the developer solution is rinsed with rinsing water in a rinsing part (rinsing step), and then subjected to a moistening treatment by coating a gum solution in a moistening part. The rinsing part contains feeding and ejecting rollers and a spray pipe, and the lithographic printing plate is rinsed by spraying rinsing water thereon from the spray pipe after passing through the feeding rollers.
In recent years, the prepress systems including a thermal plate is becoming to handle high definition images, and high definition images having a large halftone dot line number with an AM screen and image patterns with a small minimum pixel size with an FM screen are being brought into the market.
As the photosensitive lithographic printing plate, a conventional negative or positive printing plate has been used, but according to the progress of a computer-to-plate (CTP) system in recent years, systems using a photopolymer plate or a thermal plate are frequently employed. In particular, a thermal plate exposed in a heat mode is significantly advanced. It is disclosed in, for example, JP-A-2003-5379 and JP-A-2003-107684 as a related art.
However, the rinsing water is discharged from the spray pipe in the rinsing part hits against the upper and lower rollers at the feeding part of the rinsing part, and runs around the rollers to intrude into the side of the developing part, and as a result, the rinsing water is accumulated in the meniscus of the feeding rollers. Upon carrying on the lithographic printing plate from the developing part to the rinsing part, there are cases where the rinsing water is carried onto the plate to cause dripping.
It has been known that the upper feeding roller in the rinsing part is generally provided with a liquid cutting member for cutting the rinsing water running around the upper roller, and for example, a metallic bar is provided. However, the lower roller is not provided with a liquid cutting member, and the rinsing liquid running around the lower roller causes dripping.
The development of the lithographic printing plate slightly proceeds until the printing plate is conveyed to the rinsing part although the developing solution is squeezed with squeezing rollers at the ejection port of the developing part.
In the case where dripping of the rinsing liquid occurs on the lithographic printing plate from the feeding rollers of the rinsing part to the side of the developing part, the development slightly proceeding is suppressed on the dripping part. As a result, the dripping part has a density different from the surroundings to cause image unevenness. In the case where a thermal positive plate is used, for example, the density on the dripping part is increased. In the case of a high definition AM screen image or FM screen image having a large circumferential length, the extent of image unevenness is further deteriorated due to the larger change in density on progress of development.
In particular, the thermal plate is liable to change in halftone dot area depending on the extent of development progress, and thus the image unevenness is liable to occur. Accordingly, it is necessary to effect a uniform developing treatment.

Processing apparatus for lithographic printing plate and process for processing the same


The invention provides a cushioned frame for a picture or other article, which has a bottom layer with edges, a relatively rigid base with first and second sides, a layer of foam material secured to the base by adhesive stripes and having the configuration the size of the base, an upper layer of material sealed along its edge portions to edges of the bottom layer to enclose the foam layer, a transparent or translucent layer over the upper layer and adapted to fit in the section defined by the adhesive stripes, this layer being secured to the upper layer by depressed heat-seal stripes and cooperating therewith to define an envelope for a generally planar article, the foam layer being compressed at the stripes which bond the transparent or translucent layer, the upper layer and the foam material layer.. The apparatus includes an adhesive applicator machine having a vat, a supporting frame slidable on guide rails above the vat, to receive bases, articulated arms for moving an adhesive printing assembly into the vat and into engagement with the bases, and an actuator for the arms. A locating device for accurate positioning of layers, a dielectric sealing device, and a die-cutting apparatus, are utilized.

Nowadays we found in the market a diverse variety of articles made of plastic materials, among them we shall refer to those which esentially consist of a solid or rigid base or support covered by a plastic layer, a fabric layer or the like. Usually these articles are sold in the form of notebooks, photo albums, picture frames, etc.
Heretofore and since this kind of articles were firstly elaborated they have been changing in order to satisfy the needs of the consumers regarding aspect and utility. In the beginning these fancy articles were made of printed cardboard or cardboard covered or enveloped with printed paper; then the cardboard began to be covered with a fabric layer instead of paper and later a layer of plastic material was used so as to achieve more durability, for instance a printed plastic vinyl material. In the case of covering with fabric the texture of the obtained product was not so acceptable since the fabric upon bonding to the support by means of an adhesive acquires a hard texture. An alternative method for avoiding this hard texture was sewing the fabric about the base or support in order to not use adhesive; however this sewing operation makes difficult a commercial production.
Many combinations of materials have been created so as to achieve a better appearance and utility of the articles, however these combinations stay limited to their bonding process which has to be applicable under commercial volumes.
One of the combinations which up to date has been successful, mainly because of its smooth finishing texture, is the one which includes a foam material between the layers of the outer materials, whereby the obtained article is cushioned in either one or both sides.
These cushioned articles are manufactered by providing: a bottom layer of heat-sealable material, a base material which confers rigidity to the article, a foam material and an upper layer of heat-sealable material; this arrangement is thermetically sealed at the edges of the upper and bottom layers of heat-sealable material, thereby enveloping the rigid base and the foam material and providing an article with a smooth cushioned finishing.


In an authentication method according to an embodiment, an electronic device receives an authentication request message based on identification information from a server apparatus. In response to the authentication request message, the electronic device receives at least one of an input for authentication approval of a specific device and an input for authentication approval of a service offered through the specific device. Then, in response to the input, the electronic device transmits authentication approval information to the server apparatus.

Normally, user authentication technique based on ID and password is used for access to a specific electronic device, a specific web service, and the like. For example, a user who desires to access a desired device or service inputs his or her ID and password for user authentication. If this input is identical to data stored earlier in a management server or the like, user authentication is completed and user access is approved.

Method for authentication and electronic device supporting the same


An emergency air system for kayaks is disclosed. The emergency air system can be coupled to a kayak skirt or may be coupled to the body of the kayak. The air system includes a breathing tube which includes a mouthpiece. Preferably, the breathing tube is secured to the kayak skirt or the kayak body with a pair of opposing, flat washers.

1. Field of the Invention
This invention relates generally to the field of emergency breathing devices, and more particularly to an emergency air breathing system for kayaks.
2. Description of the Prior Art
People have been using kayaks as a means of water transportation for hundreds of years. Kayaks have a relatively flat bottom and are prone to tipping over. The tipping phenomenon is so common that most kayaks have a flexible skirt that creates a relatively water tight seal around the kayakers waist and around the top opening of the rigid body of the kayak. With this seal, a kayaker can flip upside down and then do a special rolling maneuver to right him or herself while the internal portion of the kayak remains relatively dry.
During this rolling maneuver there is obviously a period of time where the kayakers head is underwater. This is usually a short time period and many kayakers practice this rolling maneuver so that in a real life situation they can flip from the upside down position to the right side up position while holding their breath. New kayakers and even veterans sometimes have a hard time completing the roll over within one breath holding period. Therefore, it is a good idea to provide an emergency breathing tube or some other breathing device so that when the kayakers head is underwater he or she can take several breaths if necessary before successfully completing the rolling maneuver.
One such device has been introduced by the Radical Gear Company of Philadelphia, Pa. In its product the lower end of a breathing tube is supported by means of a foam tube holder on the lap of the kayaker. The breathing tube then extends up the skirt of the kayak and proceeds under the life jacket of the kayaker, terminating in a mouthpiece which is meant to be positioned to one side of the kayakers face. A second such device is described in German Patent DE 3931961 A1 to Schultz, where a tube extends up the skirt of the kayak, proceeds under the life jacket of the kayaker, and terminates in a mouthpiece in front of the kayaker""s face. While these configurations do give a degree of emergency breathing when the kayaker is submerged, there are some serious disadvantages to the designs.
One disadvantage is that because a kayaker is constantly moving and twisting, there is a tendency for the mouthpiece portion to migrate to an inappropriate position, such as under the life vest rather than above it. In this case the kayaker would have to take valuable time to reorient the mouthpiece to the proper position and, more importantly, the kayaker has to take at least one hand off the paddle thereby increasing the chance of losing the paddle.
A further disadvantage of the breathing devices by Radical Gear Co. and Schultz is that neither the mouthpiece portion of the breathing tube nor the opposite end of the breathing tube is sealed. Therefore, the kayaker can receive incoming water which can potentially be breathed in by the kayaker. The tube must be purged of water before breathing. This action is difficult because of the length of the tube and the tendency of water to collect on the inside walls of the tube which can run back into the mouth of the kayaker.
In both the device by Radical Gear Co. and the German Patent (Schultz, DE 3931961 A1), a further disadvantage is that, by not being permanently attached to the kayak or the skirt, they are both prone to being left behind on shore. Weather and water conditions often deteriorate unexpectedly, resulting in an unanticipated need for an emergency breathing device.
An additional disadvantage of both the Radical Gear Co.""s device and the Schultz device is that both allow the kayaker to adopt a vulnerable position, where the head is lower in the water, and prone to impact with obstruction. The preferred position upon capsize is a tucked position where the face is as close to the kayak""s deck as possible.
Finally, there is a disadvantage in the prior art in that during the rolling maneuver, the torso and head of the kayaker must be free to bend to a series of extreme positions, first, to bend forward and to one side (the xe2x80x9cset-upxe2x80x9d position), then outstretched to this side, then sweeping to a position outstretched on the opposite side, and finally stretched backward so that when the roll is completed, the kayaker is lying, head back, on the aft deck. It is apparent that during this process, a tube of fixed length running from the mouth down the chest would limit the necessary upper body movements considerably.
An attempt to solve the emergency breathing problem for kayakers was proposed by Fred Schoettle in his U.S. Pat. No. 5,671,694 issued Sep. 30, 1997. This patent describes an emergency breathing device for kayakers in which a pair of air bladders are installed inside the body of the kayak. A thin flexible hose is attached to the bladders which terminates at its opposite end by a mouthpiece which has a hand operated on-off valve. A hook mounted to the side wall of the kayak secures the mouthpiece when not in use. The main problem with this design is that to use this system, the seal between the skirt and the deck must be violated. This would result in a significant amount of water flooding into the boat. Another problem is that the kayaker has to use two hands to remove the mouthpiece for use and to turn the valve to the flow position. This means that the kayaker has to let go of his or her kayak paddle to use the device. Losing ones paddle puts the kayaker in danger because he or she has to struggle to retrieve the paddle. In many cases, retrieving the paddle may quickly become impossible. Additionally, because of the length of the flexible tube, the kayaker may unintentionally get tangled in the tube as well has have difficulty in breathing due to the nature of the long thin tube. Finally, the proposed air bladders take up valuable space in the interior of the kayak and add complexity and cost to the emergency apparatus described.
Therefore, what is needed and what has been invented is a kayak having an emergency breathing device which overcomes the disadvantages of the prior art. What is further needed and what has been invented is a method for retrofitting existing kayaks to produce kayaks not possessing the disadvantages associated with the prior art.
One object of the invention is to provide a better emergency breathing system that allows a kayaker to breathe while underwater.
Another object of the invention is to provide an emergency breathing system that does not collect water while in the standby mode.
Another object of the invention is to provide an emergency breathing system that is easy for the kayaker to reach while under water.
Another object of the invention is to provide an emergency breathing system where the kayaker can not become dangerously entangled by the breathing tube while in the submerged position.
Another object of the invention is to provide an emergency breathing system which is normally available as needed.
Another object of the invention is to provide an emergency breathing system which is simple in construction and easy to manufacture.
Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, preferred embodiments of the present invention are disclosed.
One embodiment of the invention is directed to an emergency air system for kayakers comprising a mouthpiece connected to a breathing tube which pierces the top surface of the kayak and is held in place perpendicularly to the top surface of the kayak, such as by a pair of opposed flat washers. The washers, or the like, are capable of being forced together by an internally threaded nut, or other standard securing means, that is capable of securing the breathing tube to a kayak skirt or to the upper deck of the kayak. The mouthpiece of the breathing tube contains a mouth-operated valve which is capable of opening the air passage of the breathing tube when needed, but preventing water from entering the tube when not needed. A hollow chamber is located below the mouthpiece which acts to catch and remove any purged water so that the water does not flow back into the kayaker""s mouth. The length of the breathing tube above the top surface of the kayak may be adjusted by loosening the threaded nut, adjusting the length and then tightening again. In this way a kayaker may have access to emergency air coming from inside the kayak when in the submerged position and yet, when not in use, the breathing tube remains free of water. The breathing air coming from inside the kayak may come from the void space existing underneath the top deck, the skirt, and between the inside hull of the kayak, or from an air-supply tank, or carbon dioxide removing filter, disposed inside the kayak. The breathing tube is accessed by the kayaker bending his or her head and torso forward, putting his or her mouth over the mouthpiece and forcing the mouthpiece to the open position by applying downward pressure with his or her teeth. In this way a kayaker may open the valve in the mouthpiece without taking a hand or hands away from holding the kayak paddle. Additionally, there is no danger of the kayaker becoming dangerously entangled in or connected by the breathing tube to the kayak when the kayaker wishes to become free of the kayak.
The present invention provides a kayak comprising a kayak body having a top deck with a deck opening. The kayak includes a kayak skirt disposed on the kayak body and around the kayak opening. The kayak skirt includes a structure defining a skirt opening and a skirt aperture. An emergency air system at least partly is supported by the kayak skirt and includes a structural portion passing through the skirt aperture.
The present invention also provides a kayak comprising a kayak body having a kayak deck defining a deck opening and a deck aperture; and an emergency air system at least partly supported by the kayak deck and including a structural portion passing through the deck aperture.
The present invention further also provides a method for a kayaker sitting in a kayak to receive a supply of air under water after the kayak has overturned. The method comprises providing a kayak having a kayaker with an upper torso extending through a deck opening of a top deck and having an emergency air system disposed within a deck aperture of the top deck or within a skirt aperture of the kayak; capsizing the kayak to cause the upper torso of the kayaker to be submerged in water; bending the upper torso forward until the mouth of the kayaker is in close proximity of a mouthpiece of the emergency air system; disposing the mouthpiece in the mouth of the kayaker such that the kayaker is able to receive a supply of air. The disposing comprises biting of the mouthpiece by the kayaker, or pulling the mouthpiece towards the kayaker""s mouth by a strap or other handle, and then biting the mouthpiece. The bending of the upper torso continues until the upper torso is generally parallel to the top deck.
Another feature of the present invention is a method for retrofitting a kayak with an emergency air system comprising:
providing a kayak having a top deck including a deck opening and having a kayak skirt with a skirt opening;
placing an aperture in either the top deck or the kayak skirt; and
disposing an emergency air system in the aperture.
Further advantages of the present invention are that it is relatively permanent, being secured through an aperture in the skirt or deck. This means that it is not prone to being forgotten at the outset of the voyage. Often, the need for rolling or an emergency breathing device are not apparent at that time. The position taken by the kayaker in order to engage the device is the preferred, defensive tucked position. As the device is secured in an aperture in front of the kayaker, and not on his or her body, the head and torso are given much more flexibility. Extreme flexibility is needed to perform a rolling maneuver, side to side and fore and aft, which the present invention does not restrict. Should a roll fail, the kayaker need only return to the tucked position and re-engage the mouthpiece.
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.


Apparatus for the pumping of fluids from a source without the need of external controls. The pump will continue to fill and empty itself as long as there is fluid filling the pump and compressed air of sufficient pressure to overcome the head against which the pump is pushing fluid.

Proposals have been made in the past to provide a pumping system which would automatically sense the presence of liquid and then pump them from one location to another. One such device, which has been in use for years is the combining of an air-driven double diaphragm pump and a pneumatic bubbler/air valve. This kind of system is available from Air Pump Company of Grand Blanc, Michigan, USA. This system requires the use of a double diaphragm pump which is generally larger than 12 inches in diameter and is used to suck fluids from one location and push them to another. This type of system is limited since it can only draw fluid up from about 25 feet depth and to reach greater depths, the pump must be lowered into a rather large well, sump or opening. In addition, the nature of the pump's mechanical action makes it an inefficient pump to use.
Another system utilizes internal controls to operate pneumatic valves and pressurize and exhaust the pump based upon the fullness of the pump. Such a system is disclosed in U.S. Pat. No. 4,467,831 to French, issued August 28, 1984. This system utilizes a displacer to load and unload spring-loaded opposing poppets and thus cause the pump body to pressurize and exhaust. This system has several inherent defects which make the use of the system fraught with maintenance and control problems. A delicate balance between the displacer weight, spring tension and friction which holds the poppets to the o-rings, in which they seat must be maintained if the pump is to function. Too much pressure on either the lower or upper poppet can cause the poppet to jam into the o-ring and "freeze" the pump. If the pressure is not great enough on the upper poppet, the spring tension can lift it off its seat and cause air to constantly stream into the pump and out its exhaust. In practice the pressure range in which this design can operate when the pump must operate within a 4-inch well casing or smaller spans about 40 psi. If the pressure to be used falls or rises outside of this range, the internals of the pump must be adjusted to accommodate such operation or the pump will fail to operate This can be a severe problem if the pressure to the pump fluctuates or the head against which the fluid is being pumped increases. In addition, when the pump is introducing pressurized air into the pump chamber to push out fluid, some of this air bleeds off out the exhaust. This causes a loss of energy. If the pump is constructed so that fluid enters through a check valve at the base of the pump, a fast influx of fluid can unweight the displacer and cause the poppets to shift. When this happens, pressurized air forces the fluid out of the pump, moving the displacer down and reseating the poppets. This action is repeated rapidly and a "stuttering" or "quick cycle" is developed. When this condition is reached, the pump rate and efficiency decreases dramatically. In addition, the friction of the o-rings against the poppets can change if the chemicals which are being pumped cause the o-rings to become lubricated or swell. This can cause the valving mechanism to shift too soon or not at all.
None of the pumping systems described above discloses apparatus and method for pumping fluid which uses a float inside of a canister which trips a pivot arm and thus alternately pressurizes and exhausts a pump chamber. None of the above systems are designed such that they can operate inside of a small volume such as a 4-inch internal diameter well casing at pressures ranges from 10 to 125 psi without adjustment to the mechanisms of operation.
None of the above systems described disclose apparatus and method which utilize a pivot arm which action opens and closes the air valves and after it has been set in motion via the travel of the float, it will complete its travel thus switching the valves which either pressurize or exhaust the pump chamber.
None of the above systems described disclose apparatus and method which has direct air contact against the fluid being pumped and does not cause a bleed of compressed air out of the exhaust of the pump when the pump is pressurizing the pump chamber.
None of the above systems described disclose apparatus and method which has direct air contact against the fluid being pumped and prevents the rapid stuttering of the pumping mechanism if fluid were to rush into a lower check valve after the pump was exhausted of compressed air.

Pneumatically powered submersible fluids pump with integrated controls


A system for performing hashing includes a controller for controlling the system and for providing a clock signal; an array of integrated circuits; in each integrated circuit, a plurality of cores for performing hashing; and in each core, a plurality of data expanders and data compressors, the data expanders and the data compressors having pipelined circuitry so that two iterations of a hashing loop are performed for each cycle of the clock signal. A method for performing hashing, includes controlling a system having an array of integrated circuits with a clock signal; performing hashing in a plurality of cores in each integrated circuit; and performing for each cycle of the clock signal, in each core, a plurality of data expansion and data compression operations, using pipelined circuitry so that two iterations of a hashing loop are performed for each cycle of the clock signal.

1. Field of the Disclosure
The present disclosure relates to systems for performing hashing at very high speeds. Systems of the type disclosed have applicability to a variety of tasks, but are well suited for the performance of Bitcoin mining.
2. Description of the Related Art
Bitcoin has been described as including a mix of three monetary processes. Bitcoin handles its own transaction processing, fraud prevention and currency issuance. In Bitcoin, each of these processes is reduced to very simple and powerful cryptographic methods that ensure that each step in a chain of steps verifies the next.
In Bitcoin, mining is analogous to a race that occurs every ten minutes where participants all compete to solve a mathematics puzzle. When a solution is found, all transactions (the buys and sells of the system) since the last puzzle was solved are wrapped up into a "block."
Mining is actually verifying and encoding these transactions. A participant who verifies and encodes the transactions receives an award of 25 Bitcoins (generally equal to several hundred dollars).
A hash is a way to compress a long number into something shorter that can be used by a computer, but uniquely identifies the long number. A basic SHA-2 algorithm used in hashing is described in U.S. Pat. No. 6,829,355 to Lilly. Bitcoin mining speeds are measured by the number of hashes that are performed per second, with Megahashes (MH/second), Gigahashes (GH/second) and now Terahashes (TH/second) being common units of measurement.
In mining, the goal is to find a hash that has a sufficient number of zeros at the beginning of the hash. This signifies that the analysis of the block is complete, and the reward is paid from the coinbase, which is an imaginary repository containing all possible Bitcoins.
There exist systems for doing Bitcoin mining. However, as these systems are capable of higher hash speeds, it becomes more difficult to earn a reward with any existing system. Sometimes the rewards must be shared by several winners who collaborated on finding a solution. Further, as hashing speeds are increased, the amount of electricity needed to operate the electronic devices associated with a mining system goes up considerably. The cost of electricity can have a significant impact on the profitability of a mining operation, especially if the award is being shared.
Thus, there is a need for a system that performs hashing at very high speeds. There is also a need for a system that can perform hashing at very high speeds using relatively small amounts of electrical energy.

High speed and low power hashing system and method


A plug-in connector having terminal provided in terminal receiving cavities. The terminals have memory card engagement sections. A memory card receiving slot is provided in the housing. The memory card receiving slot spans the terminal receiving cavities. A portion of the memory card receiving slot is in alignment with each of the terminal receiving cavities. An elongated opening extends between the memory card receiving slot and the terminal receiving cavities. A memory card is positioned in the memory card receiving slot. The memory card stores data which is identifiable to the specific device and allows the data to be easily conveyed.

Devices and systems often require date to be gathered for service or technical support. Today, data is gathered in various ways and subject to interpretation of the device being recorded leaving data sometimes very subjective.
It would, therefore, be beneficial to provide a cost-effective, pluggable electrical connector which incorporates a memory card, such as an EEPROM device, which allows for the storage of data which is specific or personally identifiable to the device and which allows information to be easily conveyed, thereby facilitating trouble shooting and repair of the device.


Embodiments of the invention are generally directed to a configurable multi-mode driver and receiver. An embodiment of a communication system includes a communication channel, and a first device and a second device coupled with the communication channel. The first device includes a driver apparatus to drive data signals on the communication channel, the driver apparatus including circuits to receive and drive the data signals, where the circuits are configurable for termination resistance of the driver circuit apparatus, and each of the plurality of circuits is comprised of one or more circuit units, the circuit units being configurable for equalization control of the driver apparatus. The second device includes a receiver to receive data signals from the communication channel as an input. Either the first device or the second device includes configurable circuit elements to provide signal reflection control for the system.

Data throughputs are increasing in chip-to-chip interconnects in applications ranging from backplanes in server systems to SOCs (systems on chip) interfaced to memories in mobile devices. This trend has been pushed forward by the increasing capacity of digital computation resulting from improvements in semiconductor technology.
Although on-chip speeds may scale upward for particular technologies, the corresponding electrical interface speeds may be restricted by issues that are unrelated to the semiconductor technology.
For example, I/O drivers are a significant component in interface design, and may present a significant bottleneck in improving overall performance in terms of speed and power. Among the issues that need to be addressed are the limitations presented by circuits that either include a termination resistance, thereby creating a significant current load, or do not include a termination resistance, and thereby create a limitation in speed for the I/O interface.

Configurable multi-dimensional driver and receiver


In a radiographic image-capturing system and radiographic image capturing method, a first image capturing process is performed, in which radiation is applied to a subject from at least one radiation source from among at least two radiation sources, whereby a first radiographic image is acquired. Based on the first radiographic image, respective doses of radiation to be emitted from the at least two radiation sources are weighted, and in accordance with such weighting, a second image capturing process is carried out, in which the respective radiation is applied to the subject from the at least two radiation sources.

1. Field of the Invention
The present invention relates to a radiographic image capturing system and a radiographic image capturing method for applying radiation from a plurality of radiation sources housed in a radiation output device to a subject, detecting radiation that has passed through the subject with a radiation detecting device, and converting the detected radiation into radiographic images.
2. Description of the Related Art
In the medical field, there have widely been used radiographic image capturing systems, which apply radiation from a radiation source to a subject and detect the radiation that has passed through the subject with a radiation detecting device in order to acquire a radiographic image of the subject. Radiographic image capturing systems that are installed in hospitals (medical organizations), for example, usually employ a thermionic emission radiation source, which is relatively large and heavy.
If such a radiographic image capturing system is directly used to capture radiographic images within hospitals while making rounds, or outside of hospitals, e.g., in medical checkup cars, at sites suffering from natural disasters, or at sites receiving home care services, then a large and heavy radiation source needs to be carried to such sites for capturing radiographic images. The process of carrying the radiation source to the site and setting up the radiation source at the site is quite burdensome for the doctor or radiological technician in charge. To solve this problem, Japanese Laid-Open Patent Publication No. 2007-103016 discloses a field-emission radiation source, which is smaller and lighter than a thermionic emission radiation source.

This patent is subject to a terminal disclaimer.

Radiographic image capturing system and radiographic image capturing method


A chain hoist having an electric drive motor connected to a gearbox by a slip clutch, wherein the slip clutch comprises an enlarged outer surface area in the form of recesses disposed in the outer surface of the slip clutch for improving heat dissipation with the recesses being implemented circumferentially in the form of a thread pitch in the outer surface of the slip clutch.

The invention relates to a chain hoist having an electric drive motor which is connected to a gearbox by means of a slip clutch.
German patent DE 102 44 865 B4 already discloses a chain hoist having an electric drive motor which, by means of a gearbox connected downstream of the drive motor, drives a chain wheel for a chain for lifting and lowering a load. In order to avoid gearbox or drive motor overload e.g. when the chain is hooked onto the no-load side, a slip clutch is disposed between the drive motor and the gearbox. The slip clutch consists of a first annular clutch element and a second annular clutch element which are in engagement via a friction lining. The first clutch element is disposed concentrically on a driven-side end of a motor shaft of the drive motor and is connected in a rotationally fixed manner to the motor shaft. The second clutch element is disposed in a comparable manner on a first end of a gearbox input shaft of the gearbox. In order to be able to adjust the activation force of the slip clutch, the gearbox input shaft is disposed in an axially displaceable manner and the gearbox input shaft together with the second clutch element is pretensioned in the direction of the first clutch element by means of a spring element.
Furthermore, U.S. Pat. No. 3,396,557 A discloses a hammer drill which is driven by means of an electric motor. The electric motor is connected to receiver for a drilling tool by means of a gearbox. Disposed inside the gearbox is a slip clutch to be activated in the event of a pre-settable torque which acts upon the drilling tool. The slip clutch comprises a cylindrical housing which on its outer side comprises radially circumferential and outwardly directed fins. These fins should allow rapid dissipation of heat from the housing.


A communication system includes a satellite constellation, one or more gateways and a network controller. The satellite constellation includes multiple satellites to facilitate communication between a number of user terminals (UTs). Each gateway communicates with one or more of the satellites. The network controller controls operation of the satellites, the gateways and the UTs. The satellites, the UTs, the gateways and the network controller include hardware that may also be software-defined network (SDN) enabled to ensure a persistent end-to-end data packet forwarding including proactive updates and reactive updates to forwarding tables. The proactive updates handle deterministic and time-synchronized link connectivity changes and the reactive updates handle ad hoc link connectivity changes.

Non-geosynchronous orbit (NGSO) satellite networks have the potential to provide very high throughput, low-delay services to end-users, allowing them to effectively complement or even compete with the terrestrial fiber and the wireless service offerings. However, end-to-end, hop-by-hop data packet forwarding in an NGSO satellite network is extremely challenging given the dynamic nature of the satellite constellation. There is a continually changing relationship between satellites and user-terminals, satellites and gateways, as well as user-terminals and gateways (in NGSO constellations where the payload performs no processing or partial processing). This continually changing relationship requires the frequent updating of forwarding tables. The network dynamism is further accentuated in NGSO constellations, which use satellite cross-links and on-board processing.
For such constellations, forwarding tables also need to be updated to account for changes in cross-link connectivity and changes in best paths between source and destination end-points. Mobile user-terminals, which change satellite connectivity based on changes in terminal location, further heighten the problem of asynchronously updating forwarding tables. Finally, the large scale associated with typical NGSO networks being envisaged (e.g., including hundreds to thousands of satellites, hundreds of gateways, and millions of end-user terminals) makes the data packet forwarding challenge truly challenging. The scale aspects are of concern to both the size of forwarding tables, especially on satellites that have limited on-board memory, as well as the amount of network bandwidth (capacity) needed for updating the forwarding tables at each network node.

Data packet forwarding in an NGSO satellite network


A development device includes a developer carrier configured to supply developer on a latent image formed on a latent image carrier to visualize the latent image. Wherein the developer carrier includes: an elastic layer formed on an outer circumferential surface of a conductive support body, the elastic layer including urethane rubber; and a top layer formed by treating a surface of the elastic layer with treatment solution that includes urethane polymer, silicone-based additive and conductive agent. The top layer includes convex parts that include the urethane rubber and concave parts in which the silicone-based additive and the conductive agent are laminated.

Generally, a replaceable development device for a printer as an image forming apparatus mainly includes a development roller that develops a toner image by attaching toner as developer onto an electrostatic latent image formed on the photosensitive body, a toner supply roller that supplies toner on the development roller, a development blade that regulates a thickness of the toner supplied on the development roller, a charge roller that uniformly and evenly charges the photosensitive body and the like.
In the development device with such a configuration, a surface of a development roller is treated with a urethane solution to give appropriate durability and a stable charge property (e.g. see JP Laid-Open Patent Application No. 2010-152024).
However, it is difficult to obtain a favorable image since it is difficult for developer on a conventional developer carrier to be appropriately charged.
Specific examples illustrated in the present invention aim to improve image quality.

Development device and image forming apparatus


A spa apparatus including a frame, a basin received in the frame, and an adjustable leg rest coupled to the frame. The adjustable leg rest is configured to slide between a first retracted position and a second extended position. The adjustable leg rest is selectively lockingly engaged by a fixation member to hold the adjustable leg rest in the desired position relative to the frame.

It is known to provide spa devices such as health spas, whirlpools, and foot spas. In particular, it is known that the treatment of a person's foot may provide therapeutic relief to various points throughout the body. Such spa devices are generally used in commercial and recreational setting for hydrotherapy, massage, stimulation, pedicure and bathing purposes.
Such spa devices may be used for spa treatments of both therapeutic and aesthetic varieties.
Many spa devices currently on the market do not include means for supporting a customer's foot and/or legs. Therefore, the customer must rest their foot on the edge of the basin of the spa device while the technician is providing a therapeutic or aesthetic procedure. This can be inconvenient for the spa technician and uncomfortable for the customer. It is therefore desirable to provide a spa device including means for supporting a customer's foot and or legs during a spa treatment.


A method for spooling data for use in joining a small table with a large table in a relational database system. The method analyzes a join condition for combining records from the small and large tables, selects qualified rows from the large table, and writes the qualified rows to a spool file. The spool file includes a first partition containing hash values of all bind terms for the join condition; a second partition including a join column with a best selective bind term; and at least one additional partition including additional join columns used in bind terms. The partitions are grouped together within a container row in the spool file, and multiple container rows are written together within a super-container row in the spool file.

A database is a collection of stored data that is logically related and that is accessible by one or more users or applications. A popular type of database is the relational database management system (RDBMS), which includes relational tables, also referred to as relations, made up of rows and columns (also referred to as tuples and attributes). Each row represents an occurrence of an entity defined by a table, with an entity being a person, place, thing, or other object about which the table contains information. Within large corporations or organizations, a database system known as an enterprises data warehouse, may contain close to a petabyte of critical data, organized into hundreds of tables, used by many thousands of persons, performing tasks across all business or organization functions. To perform essential functions, it must operate efficiently and reliably every second of every day.
In-memory processing capabilities have recently been implemented within database systems, where data is stored and processed in CPU memory, offering much faster processing times than systems and applications limited to processing data in non-volatile or persistent storages, e.g., Hard Disk Drives (HDDs), Solid State Disk Drives (SSDs), and Flash memory.
Within relational database systems, a join operation is executed to combine records from two or more tables. A hash join is one form of join well suited to in-memory processing. In one form of hash join, the smaller table being joined is built as a hash table in CPU memory, and qualified rows from a second, or large table, are written to a spool file—a temporary file typically used to hold intermediate result data. Potential matching rows from the large table spool file are searched against the hash table.
Described below is an improved spool table structure compatible with in-memory processing for increasing cache efficiency during hash join processing.

Spool file for optimizing hash join operations in a relational database system


A compact fluorescent lamp comprises a fluorescent tube having a helical portion on at least a part thereof and turned down in the middle, a pair of tube ends thereof each provided with a discharge electrode, the pair of tube ends juxtaposing with each other in the same direction, a holder for holding the tube ends so as that the fluorescent tube is supported at the one side thereof, a lighting device for supplying a high-frequency power to the fluorescent tube, the lighting device comprising a circuit board facing the other side of the holder and circuit elements mounted on the circuit board, a cover for accommodating the lighting device, the cover opening at both ends and holding the holder at the one opening end, and a cap fixed to the other opening end of the cover for supplying a commercial power to the lighting device by being mounted to a socket of luminaire, wherein a thin tube is protruded from at least one of the tube ends of the fluorescent tube in the cover, and the thin tube is communicated with the fluorescent tube.

In recent years, compact fluorescent lamps have been downsized in comparable to ordinary incandescent lamps, and invite an increasing replacement demand from such incandescent lamps.
As an example of such a compact fluorescent lamp, Japanese patent application Tokkai 2000-228169 (prior art A) discloses those wherein a fluorescent tube is helically packed.
However, there is a tendency that a heat dissipation efficiency of fluorescent tubes falls down and thus the temperature thereof rises up, along with the downsizing thereof. Such a tendency is especially remarkable in a compact fluorescent lamp in which the fluorescent tube is accommodated in a globe for assimilating its appearance to the ordinary incandescent lamp. When fluorescent-tube encapsulating mercury therein is heated to high temperature, a mercury vapor pressure in the fluorescent tube rises excessively, and its light output falls. Therefore, Japanese Patent 3262168 (prior art B) proposes a technique for optimizing the mercury vapor pressure, raising the mercury vapor pressure at a lighting start, and improving the light flux rise-up characteristic by putting an amalgam mercury and any one of indium, lead, tin, bismuth, etc. in the vicinity of discharge electrode of the fluorescent tube.
On the other hand, Japanese utility patent application Sho 61-63759 (Prior Art C) proposes a technique for inducing a cool spot presenting a desirable temperature capable of holding a high mercury vapor pressure in a low temperature state even in a light-out time to improve the light flux rise-up characteristic by protruding a thin tube from the fluorescent tube, without amalgam. However, Prior art C has a drawback that in case of the fluorescent tube being enclosed in a globe, the temperature of the cool spot fails to fall to a desired temperature, since the heat generated by the So, a cool spot with a desired temperature can be induced on the thin tube by dividing the inside of an envelope containing the globe into a can be divided into a fluorescent tube compartment and a lighting device compartment with a partition, and then protruding the thin tube from the tube end into the lighting device compartment by 5-20 mm long.
In the prior art B provided with a main amalgam and an auxiliary amalgam, mercury transfers from the main amalgam to the auxiliary amalgam lasting for about several weeks or several months until the mercury vapor pressure reaches an equilibrium state after the lamp has lighted out. However, according to an experiment using, for example, an absorption method, the change of the mercury vapor pressure becomes very gradual afterward about 10 hours from the time the light-out. It has been found that in the meantime the mercury vapor pressure is determined by broadly the composition of the main amalgam. (see "2002 Manuscripts of Japan Lighting Society National Conference, No. 7) The mercury vapor released from the auxiliary amalgam near the discharge electrode diffuses toward the center of the fluorescent tube, and spreads entirely in the fluorescent tube within broadly several minutes. The entire of the lamp reaches thermal equilibrium within broadly several tenths of minutes to one hour. At that time, the mercury vapor pressure becomes constant at a vapor pressure determined by the temperature of the main amalgam. At that time, the auxiliary amalgam is 100 degrees C. or more, or in some situations, 200 degrees C. or more. As a result, most mercury is substantially released from the auxiliary amalgam (to be exact, metal substance such as indium constituting the auxiliary amalgam).
However, even a fluorescent lamp equipped with auxiliary amalgam is difficult to raise promptly the mercury vapor pressure just after a lighting start, and to assure a desired lightness.
In a globe-less compact fluorescent lamp, even if a cool spot is inducing on a portion of the fluorescent tube, there is a case that the cool spot fails to become a sufficient low temperature depending to its posture. Merely by dividing the inside of the envelope with a partition and protruding a thin tube into a lighting device compartment by slightly around 5-20 mm, the fluorescent tube compartment is left at a high temperature. So that the protruding portion fails to be sufficiently cooled. In a state that the mercury vapor pressure is relatively high during a light-out state, major part of mercury vapor in the fluorescent tube is converging on the cool spot. Therefore, it takes a long time until the lamp gets warm to the temperature for releasing the mercury vapor from the cool spot by which mercury vapor is emitted from a cool spot at a re-lighting.
The present invention has an object to provide a compact fluorescent lamp having a favorable light flux rise-up characteristic and luminaire using the same, in consideration of resolving the problems as described above.

Compact fluorescent lamp and luminaire using the same

Toshiba Lighting & Technology Corporation


The present invention provides a method for controlling a selectable one-way clutch, or SOWC, such that engine braking is enabled. Additionally, the method of the present invention is adapted to provide engine braking using the SOWC such that a separate clutch is not required. The method is initiated by identifying a downshift command. After the downshift command has been identified, the off-going clutch associated with the current speed ratio is released. Engine speed is preferably increased to bring the relative speed across a selectable one-way clutch to approximately zero. Thereafter, the selectable one-way clutch is engaged such that is capable of holding torque in both directions. As the selectable one-way clutch can hold torque in both directions, torque is transmittable from the transmission to the engine and engine braking is thereby enabled.

Automatic transmissions generally effect a ratio change by altering the power delivery path after selective actuation of one or more friction elements. It is common to provide a one-way clutch configured to transfer torque from an engine to the transmission, and to interrupt the transfer of reverse torque from the transmission to the engine. However, the interruption of the transfer of reverse torque to the engine also precludes engine braking. "Engine braking" is a method for decelerating a vehicle using engine compression so that energy is dissipated without exclusively relying on conventional friction based brake systems. Therefore, implementation of engine braking in combination with a conventional friction based brake system increases the lifespan of the conventional brake system by reducing wear and heat generation.


A method includes receiving, at a processor of a computing device, a first search query during editing of a design, the first search query including at least a first search term. The method also includes identifying at least one style attribute associated with the design and searching at least one database based on the first search term, the at least one style attribute, or a combination thereof, to generate search results. The method further includes outputting the search results. A first search result of the search results is ranked higher than a second search result of the search results based on a determination that the first search result more closely matches the at least one style attribute associated with the design than the second search result.

Due to the increasing popularity and availability of the Internet, users have access to far more media content than before. This has resulted in large stock image databases that are available to users, so that the users can choose stock images to use in their own graphic designs. However, because such databases can be large (e.g., include hundreds of millions of images, or more) it may be difficult and time consuming for a user to search the databases to find search results (e.g., images) that are of interest. Consequently, users are spending an increasing amount of time searching and browsing online databases to identify images that are of interest (e.g., suitable for use in a particular graphical design).

Systems and methods of matching style attributes


The power steering system of this invention has a motor which provides auxiliary torque for the steering shaft to assist in steering.. The maximum level of the motor current is varied in response to the mean motor current at predetermined intervals of time so as to regulate the maximum motor current and thereby prevent overheating or burning of the motor when, for example, the steering wheel is held for a long time in an extreme position.

A conventional system of the above described type is arranged to have a motor which provides auxiliary power used to assist in steering for a steering shaft of a rack steering gear via a speed reduction system by way of a transfer mechanism such as a gear or a belt.
However, the above described coventional system involves the problem that the motor generates excessive heat due to the considerable amount of current continuously flowing therethrough and this may in turn generate smoke or unpleasant smells from the motor and may eventually cause critical damage if the motor suffers from burning at such times as when the steering wheel is held for a long period of time at its extreme positions when fully rotated while the vehicle is stationary and when a lot of time is used in putting a car into a garage.

Power steering system of motor drive type


Disclosed is a channel estimation method using a cooperative multi-point (CoMP) reference signal in a multi-cell environment. The method comprises a CoMP reference signal receiving step of enabling a terminal to receive, from each of the cells that perform a CoMP operation, a CoMP reference signal where an orthogonal code is applied to each of the cells; a channel estimation step of enabling the terminal to estimate, using said CoMP reference signal, channels of each of the cells which perform said CoMP operation; and a channel status feedback information transmitting step of enabling the terminal to transmit channel status feedback information to each of the cells.

Multiple Input Multiple Output (MIMO) has recently attracted much attention as a broadband wireless mobile communication technology. A MIMO system increases data communication efficiency using a plurality of antennas. The MIMO system can be implemented in a MIMO scheme such as spatial multiplexing or spatial diversity depending on whether the same data is transmitted or not.
In spatial multiplexing, different data is transmitted simultaneously through a plurality of transmission antennas, thereby enabling high-speed data transmission without increasing a system bandwidth. Spatial diversity is a scheme that achieves transmit diversity by transmitting the same data through a plurality of transmission antennas. Space time channel coding is an example of spatial diversity.
In addition, MIMO schemes may be categorized into open-loop MIMO schemes and closed-loop MIMO schemes depending on whether a receiver feeds back channel information to a transmitter. The open-loop MIMO schemes include BLAST that can increase the amount of information as much as the number of transmission antennas by transmitting information in parallel from a transmitter and detecting a signal by repeating ZF (Zero Forcing) or MMSE (Minimum Mean Square Error) detection at a receiver and STTC (Space-Time Trellis Code) that can achieve transmit diversity and a coding gain by using a new spatial region. TxAA (Transmit Antenna Array) is a closed-loop MIMO scheme.
In a radio channel environment, a channel state changes irregularly in the time and frequency domains, which is called fading. Thus, a receiver corrects a received signal using channel information to recover data transmitted by a transmitter and detect a correct signal.
In a wireless communication system, a transmitter transmits to a receiver a signal known to both the transmitter and the receiver so that channel information is detected based on distortion that the signal has experienced during transmission on a channel. This signal is called a reference signal (or a pilot signal) and channel information detection is called channel estimation. The reference signal is transmitted with high power, without carrying actual data. When data is transmitted and received through a plurality of antennas, the channel state between each transmission antenna and each reception antenna should be determined and thus a reference signal exists for each transmission antenna.
A cooperative MIMO system was proposed to reduce inter-cell interference in a multi-cell environment. In the cooperative MIMO system, multi-cell Base Stations (BSs) can jointly support data for a UE. The BSs may also support one or more UEs, MS1, MS2, . . . , MSK simultaneously in the same frequency resources to increase system performance. Further, the BSs may perform Space Division Multiple Access (SDMA) based on channel state information between the BSs and a UE.
A serving BS and one or more cooperative BSs are connected to a scheduler through a backbone network in the cooperative MIMO system. The scheduler may operate based on feedback channel information about the channel states between the UEs, MS1, MS2, . . . , MSK and the cooperative BSs, measured at the BSs, BS1, BS2, . . . , BSM, received through the backbone network. For example, the scheduler schedules information required for a cooperative MIMO operation for the serving BS and the one or more cooperative BSs. That is, the scheduler directly issues commands regarding a cooperative MIMO operation to each BS.
CoMP was proposed to reduce inter-cell interference and improve the performance of UEs at a cell edge in the multi-cell environment. That is, a CoMP system can improve the communication performance of cell-edge UEs in the multi-cell environment. For this purpose, there is a need for accurate channel estimation based oh reference signals received from multi-cell BSs.
However, as more cells perform a CoMP operation, conventional CoMP reference signals have the shortcoming that a PN (Pseudo Noise) code is shortened within one resource block and lack of dispreading samples during channel estimation degrades channel estimation performance. Therefore, a new CoMP reference signal pattern is required to guarantee accurate estimation of channels from neighbor cells for a UE performing a CoMP operation.
Moreover, no CoMP reference signals have been defined so far for LTE-A (Long Term Revolution-Advanced).

Method for transmitting and receiving a comp reference signal in a multi-cell environment


A heating/warming textile article (11) with a fabric body (13) with electrical resistance heating/warming elements (15) also contains a phase change component (17) which releases and absorbs latent heat in a cycle corresponding to ON/OFF operation of a power source (23), e.g., a battery, thus to conserve and extend useful battery life.

This invention relates to textile articles with heating/warming, and more particularly to such heating/warming textile articles incorporating phase change components.
All common forms of chemical matter are found in one of three phases, i.e. solid, liquid, or gas, depending upon temperature and pressure conditions of the local environment. It is known that a change of phase requires either release of latent heat energy or requires addition of latent heat energy. More specifically, changing the phase of a material from solid to liquid or from liquid to gas (or, in the case of, e.g., carbon dioxide or xe2x80x9cdry icexe2x80x9d directly from solid to gas) requires addition (application) of a predetermined amount of energy (heat), measured, e.g., in calories. Conversely, change of phase of a material from gas to liquid or from liquid to solid (or gas to solid) requires release or removal of energy (heat). Each change of phase for a particular material, or combination of materials, occurs under predetermined combinations of temperature and pressure.
Others have suggested employing phase change materials in thermal insulation. For example, Colvin et al. U.S. Pat. No. 5,804,297 describes a coating employing microencapsulated phase change material for the purpose of insulating a substrate against thermal transients or impulses.
According to the invention, a heating/warming textile article consists of a fabric body with electrical resistance heating/warming elements that generate heating/warming upon application of electrical power, e.g., from a battery mounted to the fabric body, and the fabric body further includes a phase change component formulated to change phase in the temperature range of use of the textile article, to cyclically absorb and release latent heat, thus to conserve and extend the useful life of the battery.
According to one aspect of the invention, a heating/warming textile article includes a fabric body, an electrical resistance element attached to the fabric body, the electrical resistance element capable of being electrically coupled to and uncoupled from an electrical power source to cyclically provide electrical power to the electrical resistance element for providing heating/warming of the textile article, and a phase change component associated with the fabric body and including a phase change material formulated to change phase in a temperature range of use of the textile article, to cyclically absorb and release latent heat in a manner capable of conserving use of the electrical power source.
Variations of this aspect of the invention may include one or more of the following features. The phase change component includes a phase change fiber that microencapsulates the phase change material. The phase change fiber at least partially forms the fabric body. The phase change fiber is incorporated into the fabric body. The phase change fiber is attached to the fabric body by at least one of knitting, weaving, stitching, embroidery stitching, laminating and applying an adhesive. The phase change component includes a coating of phase change material on fibers the fabric body. The electrical resistance element includes a conductive yarn and the phase change component comprises a coating on the conductive yarn. The electrical resistance element includes a conductive yarn and the phase change fiber is stranded together with the conductive yarn. The temperature range of use of the textile article is about 32xc2x0 F. to about 120xc2x0 F. The phase change material includes at least one of paraffin and glycol. The power supply is a battery. The battery is mounted to the article. The heating/warming textile article includes a controller for controlling the electrical power supplied from the power supply to the electrical resistance elements. The controller includes a timer. The controller includes a thermostat.
In another aspect, the invention provides a method of conserving a useful life of a battery used to power a heating/warming textile article, the article including electrical resistance elements. The method includes associating a phase change component with the fabric body, the phase change component including a phase change material formulated to change phase in a temperature range of use of the textile article; applying power from the battery to the electrical resistance elements to raise the temperature of the heating/warming article and to cause the phase change material to change from a first phase to a second phase; electrically disconnecting the battery from the electrical resistance elements; and allowing the phase change material to change phase from the second phase to the first phase before applying additional power from the battery to the resistance elements.
According to another aspect of the invention, a heating/warming textile article consists of a fabric body with electrical resistance heating/warming elements that generate heating/warming upon application of electrical power, e.g., from a battery mounted to the fabric body, and the fabric body further includes a phase change component formulated to change phase in the temperature range of use of the textile article, to cyclically absorb and release latent heat, thus to conserve and extend the useful life of the battery.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings.

Heating/warming textile articles with phase change components


A beverage bottle is provided, with a sidewall detail representing a gemstone, in which the gemstone representation is carried by and secured to the sidewall of the bottle, either directly on the surface thereof, or in a recess thereof, with or without a setting, with the gemstone representation preferably having a plurality of facets for reflecting light outwardly of the gemstone and thereby suggesting a quality product in the bottle.

Beverage bottles for various beverages, including alcoholic beverages, have long been adorned with stickers, paintings and the like, generally for purposes of advertisement, for displaying trademarks, for displaying pictures of distilleries, wineries, etc . . . , and almost always for merchandising reasons.
The present invention is directed to providing a beverage bottle with a sidewall detail representing a gemstone, thereby creating a suggestion of quality associated with the beverage contained within the bottle, product differentiation and/or noticeability of the product.
The gemstone can take on various forms, but will preferable have cut surfaces to simulate or comprise facets. The gemstones can be oval, octangular, circular, rectangular (for example, representing an emerald cut), pear-shaped or the like, with or without color and faceted or non-faceted. The gemstones can be configured in any desired manner, the above examples being by way of illustration, only and not limiting.
Additionally, the gemstones can be adhered to the surface of the bottle. They can be imbedded in a recess in the wall of the bottle. They can be set in a setting, such as a band-like setting, a tiffany setting, or any other type of setting. The gemstone will preferable protrude somewhat from the exterior surface of the bottle for an enhanced three-dimensional depiction.
Accordingly, it is primary of the this invention to provide a beverage bottle having a sidewall detail representing a gemstone, wherein the gemstone is three-dimensional and is carried by the sidewall of the bottle.
It is another object of this invention to accomplish the above object, wherein the gemstone protrudes outwardly from the sidewall of the bottle, and is recessed in a recess in the sidewall of the bottle.
It is a further object of this invention to provide an optional ring-like or band-like or other setting for the gemstone.
Other objects of this invention, such as providing opaque coatings on the rear surface of the gemstone facing the bottle sidewall, providing some level of transparency to the facets of the gemstone that face outwardly from the bottle, are also aspects of this invention.
Other objects and advances of the present invention will be readily apparent from a reading of the following brief descriptions of the drawing figures, the detailed descriptions the preferred embodiments, and the appended claims.


A system and method for guiding server chassis enumeration in a computer system are disclosed. One embodiment provides a method of connecting a plurality of computer server chassis configured as a plurality of nodes. For each cable connection between any two server chassis, a port on the first of the two server chassis to which a first end of a cable is connected is identified, and a port on the second server chassis to which a second end of the cable is connected is identified. The node containing second server chassis is uniquely designated by the port designator on the first server chassis, and the node containing the first server chassis is uniquely designated by the port designator on the second server chassis. An electronic alert is generated in response to any conflicting node designator.

1. Field of the Invention
The present invention relates to network connections in computer systems, and more particularly to guiding cable connections between multiple server chassis of a computer system.
2. Background of the Related Art
Large, sophisticated computer systems are often formed by interconnecting a plurality of smaller computer systems to combine the computing resources of the smaller computer systems. For example, a multi-blade server chassis may provide the combined computing resources of a plurality of blade servers in the server chassis. Multiple server chassis may be supported on racks to form even larger computer systems. A datacenter may include numerous equipment racks on which a large number of server chassis are supported. A large computer system comprised of multiple server chassis typically requires numerous, very specific cable connections to achieve the desired system configuration. The large number of very specific cable connections required creates the risk of human error, even in the hands of a knowledgeable system installer.

Automatic verification of network cable connections

International Business Machines Corporation


A lamp for emitting light, comprising a transparent sheet-like lightguide, with at least one light receiving side, a light emission front surface and a back surface opposite the front surface. The lamp further comprises a plurality of light sources, positioned in an array and optically coupled to at least one light receiving side. The back surface of said lamp comprises a plurality of optical extraction structures, for example provided in parallel curved lines. Furthermore, the lamp is substantially free from light scattering structures in a light path of the light to be emitted.

So-called backlights of e.g. liquid crystal displays generally have a similar construction, comprising a side-lit lightguide, and extraction features to extract the light out of the lightguide. Such backlights may e.g. be relatively flat lamps that still have a large light emitting area. Often, these backlights have to fulfill the requirement of providing lighting as homogeneously as possible, and in particular the light extraction structures are adapted to this goal.
However, a disadvantage of such backlights, or lamps of this kind in general, is that the direction of the emitted light is much less well-defined. A desirable control over lighting properties cannot be obtained with such lamps with homogeneously, yet substantially randomly, emitted light.
It is an object of the present invention to provide a flat lamp having the known advantages of the known lamp, but that in addition is able to emit light with a better-defined behavior. This better-defined behavior in turn can provide special properties hitherto not supplied by e.g. backlights.


A method of calculating a motor position uses a hall sensor. The method can include determining a motor position in response to a signal change of a hall sensor installed to a motor, calculating a basic compensation value for compensating a motor position error due to signal measurement delay of the hall sensor, determining whether a current command condition for a constant-speed operation of the motor is satisfied, calculating a first-up compensation value and a first-down compensation value, calculating an average values of the deviation between d-q axes current commands, and correcting the motor position using the basic compensation value when a difference between the average values is less than a reference average value.

In a fuel cell vehicle, a motor for air compressor is mounted for supplying air used for the power generation of the fuel cell, and a sensor for detecting a rotor position of the motor is used for precisely controlling the motor.
As the sensor for detecting the rotor position of the motor, a resolver sensor, a hall sensor, etc. can be used. In the resolver sensor, precise detection is possible compared to the hall sensor. But there is the disadvantage that it is expensive. The hall sensor is inexpensive compared to the resolver sensor, but there is the disadvantage that detection precision is low.
Meanwhile, since torque oscillation phenomenon occurs upon the high-speed rotation of the motor, the delay with respect to signal value measurement of the hall sensor is present in case of detecting the rotor position of the motor (hereinafter, referred to as 'a motor position') using the hall sensor. There occur the problems that calculation precision of the motor position is reduced due to the delay of the signal value measurement of the hall sensor and eventually, control precision of the motor speed is reduced.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Korean Patent No. 10-1655537 is related to subject matter disclosed in the specification.

Method of calculating motor position using hall sensor