Hamming code - Hamming code In telecommunication, a Hamming code is an error-detecting and error-correcting code, used in data transmission, that can (a) detect all single- and double-bit errors and (b) correct all single-bit errors. It was named after its inventor: Richard Hamming. Note: A Hamming code satisfies the relation 2m ≥ n+1, where n is the total number of bits in the block, k is the number of information bits in the block, and m is the number of check bits in the block, where m = n- k . Hamming codes in action Let us examine the Hamming (7, 4) code. We write a matrix (note each column is a binary digit) and we create a codeword vector: where a, b, and c are check digits, created.
Error-correcting code - Error-correcting code In information theory and coding, an error-correcting code or ECC is a code in which each data signal conforms to specific rules of construction so that departures from this construction in the received signal can generally be automatically detected and corrected. It is used in computer data storage, for example in dynamic RAM, and in data transmission. Examples include Hamming code, Reed-Solomon code, Golay Code, and others. The simplest error correcting codes can correct single-bit errors (single error correction or SEC) and detect double-bit errors (double error detection or DED). Other codes can detect or correct multi-bit errors. Note 1: If the number of errors is less than or equal to the maximum correctable threshold of the code, all errors will be corrected. Note 2: Error-correcting.
Error-detecting code - Error-detecting code In information theory and coding, an error-detecting code is a code in which each data signal conforms to specific rules of construction so that departures from this construction in the received signal can generally be automatically detected. This concept is applied in telecommunication. It is less powerful but very similar to an Error-correcting code. A notable error detecting (and error correcting) code is the Hamming code. Note 1: Error-detecting codes require more signal elements than are necessary to convey the basic information. Note 2: The two main classes of error-detecting codes are block codes and convolutional codes. See also Error-correcting code - Parity.
Code - Code In communications, a code is a rule for converting a piece of information (for example, a letter, word, or phrase) into another object or action, not necessarily of the same sort. One reason for this is to enable communication in places where ordinary spoken or written language is difficult or impossible. For example, a cable code replaces words (eg, ship, invoice, ...) into shorter words, allowing the same information to be sent with fewer characters, more quickly, and most important, less expensively. Another example is the use of semaphore flags, where the configuration of flags held by a signaller or the arms of a semaphore tower encodes parts of the message, typically individual letters and numbers. Another person standing a great distance away can interpret.
Richard Hamming - Richard Hamming Richard Wesley Hamming (February 11, 1915 - January 7, 1998) was a mathematician whose work had many implications for computer science and telecommunications. His contributions to science include the Hamming code, the Hamming window and the Hamming distance. He was born in Chicago, Illinois and died in Monterey, California. He received his bachelor's degree from the University of Chicago in 1937, a master's degree in 1939, and finally a PhD from the University of Illinois at Urbana-Champaign in 1942. He was a professor at the University of Louisville when the war was going on, and left to work on the Manhattan project in 1945, programming one of the earliest electronic digital computers to calculate the solution to equations provided by the project's physicists. The objective.
Glossary of coding terms - copyright-related issues, as not all parts of the source document are in the public domain. adaptive predictive coding (APC) -- alphabetic code -- alphanumeric code -- analog decoding -- analog encoding -- analog-to-digital converter (ADC) -- balanced code -- bar code -- Baudot code -- BCH code -- B8ZS -- binary code -- binary-coded decimal (BCD) -- binary-coded decimal notation (BCD) -- binary element -- binary notation -- bipolar signal -- bit configuration -- bit pairing -- B6ZS -- B3ZS -- code -- codec -- code character -- coded character set -- code-division multiple access (CDMA) -- comma-free code -- data network identification code (DNIC) -- delay encoding -- dense binary code -- differential encoding -- differential Manchester encoding -- digital alphabet -- dipulse coding -- direct-sequence spread spectrum -- duobinary.
Error-correction - error in transmission or storage, it is possible to construct error-correcting codes in which the likelihood of failure is arbitrarily low. It gives a bound on the efficiency that such schemes can achieve. Error-correction in practice is complicated by the fact that errors might occur in bursts rather than at random. This is often compensated for by shuffling the bits in the message after coding in such a way that a burst of bit-errors is broken up into a set of scattered single-bit errors when the bits of the message are unshuffled before being decoded. Block error-correcting codes, like Hamming codes, and Reed-Solomon codes transform a chunk of bits into a (longer) chunk of bits in such a way that errors up to some threshold in each block can be detected.
Error control - remarkably long - with long dramatic delay - and is prone to errors. In this case, it is not practical to send retransmission requests. Instead, sets of redundant information is sent with the data, so that correction can be done on the fly. ARQ is an interactive way of correcting errors by bouncing back and forth between a sender and a receiver until accuracy is ensured. See also: Reed-Solomon error correction, Hamming code.
David A. Huffman - finite state machines, switching circuits, synthesis procedures, and signal designs. However, David Huffman is best known for his legendary Huffman code, an optimal compression scheme for lossless variable length encoding. It was the result of a term paper he wrote while a graduate student at the Massachusetts Institute of Technology (MIT). "Huffman Codes" are used in nearly every application that involves the compression and transmission of digital data, such as fax machiness, modems, computer networks, and high-definition television (HDTV), to name a few. Huffman joined the faculty at MIT in 1953. In 1967, he went to University of California, Santa Cruz as the founding faculty member of the Computer Science Department. He played a major role in the development of the department's academic programs and the hiring of its faculty, and.
Redundant array of independent disks - RAID 0 and backed up to tape or optical media.) Recommended Applications Video Production and Editing Image Editing Pre-Press Applications Any application requiring high bandwidth RAID 1: Mirroring and Duplexing (Mirrored) For Highest performance, the controller must be able to perform two concurrent separate reads per mirrored pair or two duplicate writes per mirrored pair. RAID Level 1 requires a minimum of 2 drives to implement Characteristics One write or two reads possible per mirrored pair. Twice the read transaction rate of single disks, same write transaction rate as single disks. 100% redundancy of data means no rebuild is necessary in case of a disk failure, just a copy to the replacement disk. Transfer rate per block is equal to that of a single disk Under certain circumstances, RAID 1 can.
List of mathematical topics (G-I) - Geometric Brownian motion -- Geometric distribution -- Geometric isomerism -- Geometric kite -- Geometric mean -- Geometric primitive -- Geometric progression -- Geometric series -- Geometric shape -- Geometric solid -- Geometry -- Geometry of numbers -- Gergonne point -- Germain -- Germain, Sophie -- Gibbard-Satterthwaite theorem -- Gibbs-Helmholtz equation -- Gibbs' phase rule -- Gibbs phenomenon -- Gift wrapping algorithm -- Gimel function -- GIMPS -- Gini coefficient -- Girsanov's theorem -- Girth -- Global field -- Globe -- Glome -- Glossary of field theory -- Glossary of graph theory -- Glossary of group theory -- Glossary of ring theory -- Glossary of tensor theory -- Gnomon -- Gödel, Kurt -- Gödel's completeness theorem -- Gödel's completeness theorem -- original proof -- Gödel's constructible universe -- Gödel's incompleteness theorem --.
List of electronics topics - link establishment Automatic Number Identification Automatic sounding Automatic switching system Autovon Availability Available line Avalanche diode Azimuth B BCS theory Backplane Backward channel Balancing network Ball grid array Band gap Bandwidth compression Bare particular Baseband Battery (electricity) Baud rate Baudot code beam beam diameter beam divergence beam steering beamwidth Bel Bias biconical antenna billboard antenna Binaural recording Binary classification Bipolar junction transistor Broadband Internet Back-to-back connection Backscattering Balance return loss Balanced line Band-stop filter Beam diameter Beamwidth Bias distortion Bilateral synchronization Bipolar signal Bit inversion Bit pairing Bit stuffing Bit synchronous operation Bit-count integrity Bits per second Black facsimile transmission Black recording BNC connector Signal boosting boresight Broadband Breadboard Bremsstrahlung Bridging loss Burst transmission Busy hour Busy signal Bypass Barrage jamming Big ugly dish Bit robbing Blanketing Bluetooth Broadband wireless access.
List of combinatorics topics - digest Deadlock Dining philosophers problem Mutual exclusion Rendezvous problem Derangement Dickson's lemma Eight queens puzzle Enumeration Algebraic enumeration Combinatorial enumeration Burnside's counting theorem Erdös-Ko-Rado theorem Faà di Bruno's formula Fifteen puzzle Finite geometry Game theory Combinatorial game theory Combinatorial game theory (history) Combinatorial game theory (pedagogy) Impartial game Nim Digital sum Nimber Sprague-Grundy theorem Partizan game Dots and Boxes Sprouts game Surreal numbers Solved board games Transposition table Hamming distance Hash function Hash collision Perfect hash function Hypergeometric series Hypergraph Knapsack problem Lah number Large number Latin square Magic square Marriage theorem Perfect matching Monge array Moreau's necklace-counting function Necklace problem Negligible set Almost all Almost everywhere Null set Packing problem Bin packing problem Permanent Permutation Permutation matrix Josephus permutation Shuffling playing cards Pochhammer symbol Polyomino Tetromino Pentomino Pentominoes Hexomino Polyamonds.
Vertical interval timecode - fit in a standard timecode frame. VITC contains the 64 data bits of the SMPTE linear timecode frame embedded in a new frame structure with extra synchronization bits and an error-detection checksum. The VITC code is always repeated on two adjacent video lines, one in each field. This internal redundancy is exploited by VITC readers, in addition to the standard timecode "flywheel" algorithm. A video frame may if necessary contain more than one VITC code, recorded on different line-pairs. This is often used in production, where different entities may want to encode different sets of time-code metadata on the same tape. See also: Burnt-in timecode MIDI timecode AES-EBU embedded timecode.
Keyed-hash message authentication code - Keyed-hash message authentication code A keyed-hash message authentication code, or HMAC, is a type of message authentication code (MAC) calculated using a cryptographic hash function in combination with a secret key. As with any MAC, it may be used to simultaneously verify both the data integrity and the authenticity of a message. Any iterative cryptographic hash function, e.g., SHA-1, RIPEMD-160, may be used in the calculation of an HMAC; the cryptographic strength of the HMAC depends upon the cryptographic strength of the underlying hash function and on the size and quality of the key. The construction and analysis of HMACs was first published in 1996 by Mihir Bellare, Ran Canetti, and Hugo Krawczyk, who also authored RFC 2104. FIPS PUB 198 generalizes and standardizes the use of HMACs. External Links.
Konami Code - Konami Code The Konami Code is a secret cheat code used in many Konami video games. At some point during the game, the player would press: Up Up Down Down Left Right Left Right B A and some sort of secret option would be enabled. There have been other variations of this code as well. In an SNES game of the Gradius series, one must use the controller's "L" and "R" triggers while the game is paused. Using the directional pad buttons instead of the triggers would cause your ship to explode. In a Playstation 2 version of the Gradius games, the "square", "triangle", "X", and "circle" buttons are used as substitutes for "B" and "A" in the traditional code. The most famous use of this code.
Vertical service code - Vertical service code A vertical service code is a ficticious telephone number that usually begins with the * (star) key on the touch tone keypad. Some cellular companies also use # to begin a vertical service code. List of vertical service codes (not all of these services are available in all areas, some are only available to wireline telephones (and unavailable to cellular callers) and some require additional services be purchased from the telephone company to use them): *67 - Private call - Informs telephone switch not to release caller-id information for this particular call. *69 - Return call - Call back the last party that dialed this number. If the caller did not use *67, this service will usually read back their number before placing the call.
Kaaawa, Hawaii - comprising the town, are confined to a relatively narrow belt along the coast. However, a long valley extends inland. Ka'a'awa Valley is part of Kualoa Ranch and used for various tourist activities as well as filming. Major films incorporating significant views of the valley include George of the Jungle and Jurassic Park. The U.S. postal code for Ka'a'awa is 96730. Geography Ka'a'awa is located at 21°33'25" North, 157°51'19" West (21.557050, -157.855148)1. Ka'a'awa is north from Kualoa and directly southeast of Kahana Bay. The next place beyond Kahana is Punalu'u. According to the United States Census Bureau, the town had a total area of 2.8 km² (1.1 mi²). 1.5 km² (0.6 mi²) of it was land and 1.3 km² (0.5 mi²) of it was water. The total area was 46.36% water, a.
Kahaluu, Hawaii - Likelike Highway first encounter the ocean (actually Kāne'ohe Bay) close beside the highway (Kamehameha Highway or State Rte. 83). Kahalu'u is a mostly rural area slowly transforming into a denser residential community. The U.S. postal code for Kahalu'u is 96744. Geography Kahaluu is located at 21°27'40" North, 157°50'28" West (21.461146, -157.841155)1. It is directly adjacent to 'Āhuimanu to the south and Wai'ahole to the north. According to the United States Census Bureau, the town has a total area of 5.9 km² (2.3 mi²). 3.2 km² (1.2 mi²) of it is land and 2.7 km² (1.1 mi²) of it is water. The total area is 46.49% water. Demographics As of the 2000 Census there were 2,935 people, 927 households, and 716 families residing in Kahalu'u. The population density was 928.9/km² (2,410.8/mi²). There.
Kahuku, Hawaii - reference to Kahuku Point nearby, the northernmost point on the island of O'ahu. As of the 2000 Census, Kahuku had a total population of 2,097. The U.S. postal code for Kahuku is 96731. Geography Kahuku is located at 21°40'49" North, 157°57'1" West (21.680333, -157.950141)1. This community is located northwest from Lā'ie and east from Kuilima and Kawela Bay along Kamehameha Highway (State Rte. 83). According to the United States Census Bureau, the town has a total area of 5.9 km² (2.3 mi²). 2.5 km² (1.0 mi²) of it is land and 3.4 km² (1.3 mi²) of it is water. The total area is 57.46% water, although all of this water is the Pacific Ocean lying off the coast included in the census tract. Demographics As of the census of 2000, there.
