| slovo | definícia |
crc
(foldoc) | cyclic redundancy check
CRC
cyclic redundancy code
(CRC or "cyclic redundancy code") A number derived
from, and stored or transmitted with, a block of data in order
to detect corruption. By recalculating the CRC and comparing
it to the value originally transmitted, the receiver can
detect some types of transmission errors.
A CRC is more complicated than a checksum. It is calculated
using division either using shifts and exclusive ORs or
table lookup (modulo 256 or 65536).
The CRC is "redundant" in that it adds no information. A
single corrupted bit in the data will result in a one bit
change in the calculated CRC but multiple corrupted bits may
cancel each other out.
CRCs treat blocks of input bits as coefficient-sets for
polynomials. E.g., binary 10100000 implies the polynomial:
1*x^7 + 0*x^6 + 1*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 + 0*x^0.
This is the "message polynomial". A second polynomial, with
constant coefficients, is called the "generator polynomial".
This is divided into the message polynomial, giving a quotient
and remainder. The coefficients of the remainder form the
bits of the final CRC. So, an order-33 generator polynomial
is necessary to generate a 32-bit CRC. The exact bit-set used
for the generator polynomial will naturally affect the CRC
that is computed.
Most CRC implementations seem to operate 8 bits at a time by
building a table of 256 entries, representing all 256 possible
8-bit byte combinations, and determining the effect that each
byte will have. CRCs are then computed using an input byte to
select a 16- or 32-bit value from the table. This value is
then used to update the CRC.
Ethernet packets have a 32-bit CRC. Many disk formats
include a CRC at some level.
(1997-08-02)
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crc
(vera) | CRC
Cyclic Redundancy Check[sum]
|
| | podobné slovo | definícia |
ahpcrc
(wn) | AHPCRC
n 1: a United States defense laboratory to conduct research in
high-performance computing for defense technology
applications; a partnership of government and university
and industry [syn: {Army High Performance Computing
Research Center}, AHPCRC] |
ccrc
(wn) | CCRC
n 1: an agency in the Department of Defense that is a national
center for research on all aspects of injury control and
casualty care [syn: Casualty Care Research Center,
CCRC] |
crc
(foldoc) | cyclic redundancy check
CRC
cyclic redundancy code
(CRC or "cyclic redundancy code") A number derived
from, and stored or transmitted with, a block of data in order
to detect corruption. By recalculating the CRC and comparing
it to the value originally transmitted, the receiver can
detect some types of transmission errors.
A CRC is more complicated than a checksum. It is calculated
using division either using shifts and exclusive ORs or
table lookup (modulo 256 or 65536).
The CRC is "redundant" in that it adds no information. A
single corrupted bit in the data will result in a one bit
change in the calculated CRC but multiple corrupted bits may
cancel each other out.
CRCs treat blocks of input bits as coefficient-sets for
polynomials. E.g., binary 10100000 implies the polynomial:
1*x^7 + 0*x^6 + 1*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 + 0*x^0.
This is the "message polynomial". A second polynomial, with
constant coefficients, is called the "generator polynomial".
This is divided into the message polynomial, giving a quotient
and remainder. The coefficients of the remainder form the
bits of the final CRC. So, an order-33 generator polynomial
is necessary to generate a 32-bit CRC. The exact bit-set used
for the generator polynomial will naturally affect the CRC
that is computed.
Most CRC implementations seem to operate 8 bits at a time by
building a table of 256 entries, representing all 256 possible
8-bit byte combinations, and determining the effect that each
byte will have. CRCs are then computed using an input byte to
select a 16- or 32-bit value from the table. This value is
then used to update the CRC.
Ethernet packets have a 32-bit CRC. Many disk formats
include a CRC at some level.
(1997-08-02)
|
ecrc
(foldoc) | European Computer-Industry Research Centre GmbH
ECRC
(ECRC) A joint research organisation founded in 1984 on
the initiative of three major European manufacturers: Bull
(France), ICL (UK) and Siemens (Germany). Its activities
were intended to enhance the future competitive ability of the
European Information Technology industry and thus complement
the work of national and international bodies.
The Centre is intended to be the breeding ground for those
ideas, techniques and products which are essential for the
future use of electronic information processing. The work of
the Centre will focus on advanced information processing
technology for the next generation of computers.
ECRC is an independent company, owned equally by its
shareholders. The formal interface between ECRC and its
shareholders consists of two bodies: The Shareholders'
Council, which approves the Centre's programmes and budgets
and supervises their execution and the Scientific Advisory
Board, which advises the Shareholders' Council in determining
future research directions.
There are many collaborations between ECRC and its
shareholders' companies on specific projects (Technology
Transfer, prospective studies etc). The Centre is staffed by
highly qualified scientists drawn from different countries.
Research staff are hired directly by ECRC, as well as some who
come on assignment from the member companies, and others
seconded from public research agencies and universities.
Seminars are held which bring together specialists from the
Centre and the member companies.
ECRC's mission is to pursue research in fundamental areas of
computer science. The aim is to develop the theory,
methodologies and tools needed to build innovative computer
applications. ECRC contributes actively to the international
effort that is expanding the frontiers of knowledge in
computer science. It plays an important role in bridging the
gap between research and industry by striving to work at the
highest academic level with a strong industrial focus. ECRC
constitutes an opportunity in Europe for the best scientists
and offers young researchers the possibility to mature in an
environment which exposes them to both fundamental research
and the process of delivering the results to industry.
ECRC plays an important role in Europe and is involved in
several European Community initiatives. It is regularly
consulted by the Commission of the European Communities on
strategic issues, such as the definition of future research
plans, international co-operation and relationships between
academia and industry.
Address: ECRC GmbH, Arabellastrasse 17, D-81925 Munich,
Germany.
(http://ecrc.de/).
Telephone: +49 (89) 926 99 0. Fax: +49 (89) 926 99 170.
(1994-12-01)
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ecrc-prolog
(foldoc) | ECRC-Prolog
Evidently Prolog with coroutine extensions.
See also SEPIA.
["ECRC-Prolog User's Manual Version 1.0", K. Estenfeld,
TR-LP-08 ECRC, Feb 1986].
(1994-12-01)
|
crc handbook
(jargon) | CRC handbook
Any of the editions of the Chemical Rubber Company Handbook of Chemistry
and Physics; there are other CRC handbooks, such as the CRC Standard
Mathematical Tables and Formulae, but “the” CRC handbook is the chemistry
and physics reference. It is massive tome full of mathematical tables,
physical constants of thousands of alloys and chemical compounds,
dielectric strengths, vapor pressure, resistivity, and the like. Hackers
have remarkably little actual use for these sorts of arcana, but are such
information junkies that a large percentage of them acquire copies anyway
and would feel vaguely bereft if they couldn't look up the magnetic
susceptibility of potassium permanganate at a moment's notice. On hackers'
bookshelves, the CRC handbook is rather likely to keep company with an
unabridged Oxford English Dictionary and a good atlas.
|
ahpcrc
(vera) | AHPCRC
Army High Performance Computing Research Center (org., USA, HPC)
|
crc
(vera) | CRC
Cyclic Redundancy Check[sum]
|
crcg
(vera) | CRCG
[Fraunhofer] Center for Research in Computer Graphics (org., USA)
CRCG
Common Routing Connection Group
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dcrc
(vera) | DCRC
Digital Cellular Radio Conference (GSM, conference,
mobile-systems)
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ecrc
(vera) | ECRC
[cable & wireless] European Computer industry Research Centre
[gmbh] (ISP, org.)
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icrc
(vera) | ICRC
Invariant Cyclic Redundancy Check (Infiniband), "I-CRC"
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rdncrc
(vera) | RDNCRC
Research Data Network Cooperative Research Centre (org.,
Australia)
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vcrc
(vera) | VCRC
Variant Cyclic Redundancy Check (Infiniband), "V-CRC"
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