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23-letter words containing u, l, n

  • cyclic redundancy check — (algorithm)   (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.
  • cylinder vacuum cleaner — a type of vacuum cleaner in which dirt, dust, etc, is sucked into a hard cylinder rather than a bag
  • d'entrecasteaux islands — a group of volcanic islands in the Pacific, off the SE coast of New Guinea: part of Papua New Guinea. Pop: 49 167 (1990 est). Area: 3141 sq km (1213 sq miles)
  • dark-field illumination — illumination of the field of a microscope from the side so that the specimen is viewed against a dark background
  • data terminal equipment — (communications, hardware)   (DTE) A device which acts as the source and/or destination of data and which controls the communication channel. DTE includes terminals, computers, protocol converters, and multiplexors. DTE is usually connected via an EIA-232 serial line to Data Communication Equipment (DCE), typically a modem. It is necessary to distinguish these two types of device because their connectors must be wired differently if a "straight-through" cable (pin 1 to pin 1, pin 2 to pin 2 etc.) is to be used. DTE should have a male connector and should transmit on pin three and receive on pin two. It is a curious fact that many modems are actually "DTE" according to the original standard.
  • database query language — (database)   A language in which users of a database can (interactively) formulate requests and generate reports. The best known is SQL.
  • debugging an empty file — (programming, humour)   A humourous definition of programming that considers a complete absence of any code as a bug to be fixed.
  • descriptive linguistics — the study of the description of the internal phonological, grammatical, and semantic structures of languages at given points in time without reference to their histories or to one another
  • dichlorodifluoromethane — a colourless nonflammable gas easily liquefied by pressure: used as a propellant in aerosols and fire extinguishers and as a refrigerant. Formula: CCl2F2
  • digital subscriber line — (communications, protocol)   (DSL, or Digital Subscriber Loop, xDSL - see below) A family of digital telecommunications protocols designed to allow high speed data communication over the existing copper telephone lines between end-users and telephone companies. When two conventional modems are connected through the telephone system (PSTN), it treats the communication the same as voice conversations. This has the advantage that there is no investment required from the telephone company (telco) but the disadvantage is that the bandwidth available for the communication is the same as that available for voice conversations, usually 64 kb/s (DS0) at most. The twisted-pair copper cables into individual homes or offices can usually carry significantly more than 64 kb/s but the telco needs to handle the signal as digital rather than analog. There are many implementation of the basic scheme, differing in the communication protocol used and providing varying service levels. The throughput of the communication can be anything from about 128 kb/s to over 8 Mb/s, the communication can be either symmetric or asymmetric (i.e. the available bandwidth may or may not be the same upstream and downstream). Equipment prices and service fees also vary considerably. The first technology based on DSL was ISDN, although ISDN is not often recognised as such nowadays. Since then a large number of other protocols have been developed, collectively referred to as xDSL, including HDSL, SDSL, ADSL, and VDSL. As yet none of these have reached very wide deployment but wider deployment is expected for 1998-1999.
  • dionysius of alexandria — ("the Great") a.d. c190–265, patriarch of Alexandria 247?–265?.
  • dishonourable discharge — dismissal from the US armed forces by a court martial as a result of serious misconduct
  • disjunctive normal form — (DNF) A logical formula consisting of a disjunction of conjunctions where no conjunction contains a disjunction. E.g. the DNF of (A or B) and C is (A and C) or (B and C).
  • dsp32 assembly language — A high-level assembly language for the DSP32 Programmable DSP Chip.
  • dual sensory impairment — the condition of being affected by sight and hearing loss
  • duplication of the cube — the insoluble problem of constructing a cube having twice the volume of a given cube, using only a ruler and compass.
  • electronic surveillance — use of electronic devices to spy, observe
  • ellipsoid of revolution — a geometric surface produced by rotating an ellipse about one of its two axes and having circular plane surfaces perpendicular to the axis of revolution
  • encapsulated postscript — (EPS) An extension of the PostScript graphics file format developed by Adobe Systems. EPS is used for PostScript graphics files that are to be incorporated into other documents. An EPS file includes pragmas (special PostScript comments) giving information such as the bounding box, page number and fonts used. On some computers, EPS files include a low resolution version of the PostScript image. On the Macintosh this is in PICT format, while on the IBM PC it is in TIFF or Microsoft Windows metafile format.
  • entrance qualifications — academic requirements
  • equivalent focal length — the ratio of the size of an image of a small distant object near the optical axis to the angular distance of the object in radians
  • exclusive economic zone — the coastal water and sea bed around a country's shores, to which it claims exclusive rights for fishing, oil exploration, etc
  • execute channel program — (operating system)   (EXCP) An IBM system for low-level file access, where the programmer is completely responsible for providing a list of device-specific "channel comands" to be executed by I/O channels, control units and/or devices. The operating system will simply check the "CCW" chains for security purposes (access invalid memory or outside of file extents) and then schedule them for execution.
  • expert judgement models — (programming)   A method of software estimation that is based on consultation with one or more experts that have experience with similar projects. An expert-consensus mechanism such as the Delphi Technique may be used to produce the estimate.
  • extremely low frequency — a radio frequency or radio-frequency band below 3 kilohertz
  • ferric ammonium oxalate — a green, crystalline, water-soluble, synthetically produced powder, (NH 4) 3 Fe(C 2 O 4) 3 ⋅3H 2 O, used chiefly in the manufacture of blueprint paper.
  • fetal tissue transplant — a surgical procedure in which tissue from an aborted fetus is grafted into a patient to replace or improve defective tissue, especially to treat Parkinson's disease or other neurological disorders.
  • fiddle while rome burns — If you say that someone is fiddling while Rome burns, you mean that they are not dealing with a difficult or dangerous situation but instead are doing useless things or pretending that nothing is wrong.
  • fifth marquis lansdowne — Henry Charles Keith, 5th Marquis of Lansdowne, Lansdowne, 5th Marquis of.
  • finite impulse response — (electronics, DSP)   (FIR) A type of digital signal filter, in which every sample of output is the weighted sum of past and current samples of input, using only some finite number of past samples.
  • fish in troubled waters — any of various cold-blooded, aquatic vertebrates, having gills, commonly fins, and typically an elongated body covered with scales.
  • fluorochlorohydrocarbon — (organic chemistry) Any compound formally derived from a hydrocarbon by replacing some hydrogen atoms with fluorine and some with chlorine (at least one being retained).
  • fraunhofer gesellschaft — (company)   (FhG, FhG IIS, Institut für Integrierte Schaltungen) A german company, named after the physicist. IIS is Integrated Circuit Institute. FhG are known for their research on audio compression, especially MPEG-1 Layer-3 (MP3).
  • frictional unemployment — those people who are in the process of moving from one job to another and who therefore appear in the unemployment statistics collected at any given time
  • function graph language — (language)   (FGL) The machine language for the AMPS (Applicative Multi-Processing System) proposed by Robert Keller, Gary Lindstrom and Suhas Patil at the University of Utah.
  • function point analysis — (programming)   (FPA) A standard metric for the relative size and complexity of a software system, originally developed by Alan Albrecht of IBM in the late 1970s. Functon points (FPs) can be used to estimate the relative size and complexity of software in the early stages of development - analysis and design. The size is determined by identifying the components of the system as seen by the end-user: the inputs, outputs, inquiries, interfaces to other systems, and logical internal files. The components are classified as simple, average, or complex. All of these values are then scored and the total is expressed in Unadjusted FPs (UFPs). Complexity factors described by 14 general systems characteristics, such as reusability, performance, and complexity of processing can be used to weight the UFP. Factors are also weighted on a scale of 0 - not present, 1 - minor influence, to 5 - strong influence. The result of these computations is a number that correlates to system size. Although the FP metric doesn't correspond to any actual physical attribute of a software system (such as lines of code or the number of subroutines) it is useful as a relative measure for comparing projects, measuring productivity, and estimating the amount a development effort and time needed for a project. See also International Function Point Users Group.
  • functional requirements — (specification)   What a system should be able to do, the functions it should perform. This term is used at both the user requirements analysis and software requirements specifications phases in the software life-cycle. An example of a non-functional requirement is an initialisation sequence incorporated into the software that is specific to a given customer.
  • fundamental interaction — any of the four basic interactions that occur in nature: the gravitational, electromagnetic, strong, and weak interactions
  • grand duchess charlotte — Grand Duchess (Charlotte Aldegonde Elise Marie Wilhelmine) 1896–1985, sovereign of Luxembourg 1919–64.
  • guest relations manager — A guest relations manager at a hotel is responsible for the relationships that the hotel has with its guests and the way in which it treats them.
  • guillain-barre syndrome — an uncommon, usually self-limited form of polyneuritis, occurring after a viral illness or immunization and manifested by loss of muscle strength, loss of or altered sensation and sometimes paralysis.
  • hang out your/a shingle — If you hang out your shingle or hang out a shingle, you start your own business.
  • heterogeneous catalysis — Heterogeneous catalysis is catalysis in which the catalyst does not take part in the reaction that it increases.
  • horsehair-blight fungus — a fungal parasite, Marasmius equicrinis, that causes a disease of certain tropical plants, especially tea.
  • human leukocyte antigen — HLA.
  • hunter-killer satellite — a satellite designed to seek out and destroy a nearby enemy satellite by exploding itself into a cloud of high-speed metal fragments.
  • hunter-killer submarine — a submarine designed and equipped to pursue and destroy enemy craft
  • hydrochlorofluorocarbon — Any of a class of inert compounds of carbon, hydrogen, hydrocarbons, chlorine, and fluorine, used in place of chlorofluorocarbons as being somewhat less destructive to the ozone layer.
  • immunological tolerance — the absence of antibody production in response to the presence of antigens, usually as a result of previous exposure to the antigens
  • implementation language — (language)   (IMP) An extension of B with floating-point operations, developed by W. Davidsen at General Electric in 1970 for the GE 600. It was also cross-compiled to VAX and Intel 8080.
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