`
`DICTIONARY OF
`DICTIONA Y OF
`
`
`ELECTRICAL &
`ELEC CAL
`
`COMPUTER
`MPUTE
`ENGINEERING
`'_
`
`EN !NEERING
`
`
`
`MORE THAN 18,000 ESSENTIAL TERMS
`
`MORE THAN 18,000 ESSENTIAL TERMS
`
`COVERS EVERY DISCIPLINE OF
`
`
`COVERS EVERY DISCIPLINE OF
`ELECTRICAL & COMPUTER ENGINEERING
`
`
`ELECTRICAL & COMPUTER ENGINEERING
`
`PROVIDES SYNONYMS, ACRONYMS, AND ABBREVIATIONS
`
`PROVIDES SYNONYMS, ACRONYMS, AND ABBREV IATIONS
`
`
`
`1
`
`APPLE 1010
`
`1
`
`APPLE 1010
`
`

`

`Tt 7 rrs-
`'tf').;IA. 3?
`?., ()() l(
`
`,
`
`2
`
`

`

`McGraw-Hill
`
`
`Dictionary of
`
`Electrical and
`Computer
`Engineering
`
`McGraw-Hill
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`The McGrow·H1/I
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`All text in the dictionary
`was published
`previously
`in the McGRAW-HILL
`DICTIONARY
`OF SCIENTIFIC
`AND TECHNICAL
`TERMS, Sixth Edition,
`copyright©
`2003 by The McGraw-Hill
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`Inc. All rights
`reserved.
`McGRAW-HILL
`DICTIONARY
`OF ELECTRICAL
`AND COMPUTER
`ENGINEER­
`ING, copyright
`© 2004 by The McGraw-Hill Companies,
`Inc. All rights
`reserved.
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`Library
`of Congress
`Cataloglng-ln-Publlcatlon
`Data
`McGraw-Hill
`dictionary
`of electrical
`and computer
`engineering.
`p. cm.
`ISBN 0-07-I 442 I 0-3
`2. Electric
`engineering­
`I. Computer
`engineering-Dictionaries.
`Dictionaries.
`TK7885.A2M37
`2004
`004' .03-dc22
`
`2004049888
`
`4
`
`

`

`
`
`
`
`
`
`Contents
`
`Preface
`
`ssssssswsesnssvixssisssvoxessesssnecssesaesssssascasssoseicestuceniboaticitec cis cht sistbCvcsk doce cctsccbeccctieaacclabecitidisN
`
`How to Use the Dictionary oooocccccccccsccccesssssesssssssessessssssssovsssssinimtenensinanisesassuavansaneen Vil
`Fields and Their Scope.......
`Pronunciation Key,..................re xi
`A~Z TOPS oneness ccesssesssssstsestsssssssesesssscesvasussvaveneesenssissangnecscesseseneensenssnsessesigentnenses 1-642
`APPONix oc csssessssntnsssnsnessseunsseennsssesaseecusseesaguesesstseusssseiusssseten 643-679
`Equivalents of commonly used units for the U.S.
`Customary System and the Metric SYSteM avecsssssssvissossssssssessesseevessssnsieeiee O45
`Conversion factors for the U.S. Customary System,
`Metric system, and International SySteM c.ccsssseccesessssssesessnsevveeeceeeeer 646
`Standard equations voces
`.
`Special constants.....
`Physical COMStANtS oc.eccsececccccccccsccscsscsscssassvvnsvevsvctesccsngsecassusasussesnepseccearsgssnnsansenmennenenee 656
`Electrical and magnetic UNITS wocccccscsssssssssssssssssssssusossssscscssssssseacessssescansesiesesen 657
`Dimensional formulas of COMMON QUANCITICS creceicssscsiecssssisvesecsesessssstecceese 658
`Internal energy and generalized WOK ooeccscssssssssscssssssesssssssnisssssenssipemiennOd8
`TrIGONOMEtriC FUNCTIONS vorccecccscsssssserseeenenensiersievennneensees
`ccsscssccsesssssssseseeen 661
`General rules ofdifferentiation and integration ic
`.
`Basic integral transforms uocsccscssssseesssssneeecee .
`Mathematical notation ...cccssssssosssssssvsssssescssssssvsssvsssrsevscssnensecesneesnsesseesterseesssesceseeteee O05
`Schematic electronic SYMDBOIS ceescicccssscsecssssssscsssssssssssssssusesseicustensnasnveveveavenpeese 672
`Partial family tree of programming langQuagesvvsiccsssssvsvsvssveecsssseeesnOT7
`ASCII] CODE onc ssniasensiaiccscsssessssiithisiaiipesesssssussssssvessssiddbeblfeessevsnceveevesceccalatedibbthOGtesseseeeseseeens 678
`Electromagnetic spectrum ...,
`Microwave frequency bands.
`RAIO SPECETUM voesccsessessssssssssssssssseecssesecepeatannenen
`
`
`
`5
`
`

`

`6
`
`

`

`Preface
`
`The McGraw-Hill Dictionary of Electrical and Computer Engineering provides a
`compendium of more than 18,000 terms that are central to these fields as
`well as related fields. In addition to computerscience, electronics, electricity,
`and electrical engineering, coverage includes terminology in control systems,
`engineering acoustics, systems engineering, and communications.
`
`The definitions are drawn from the McGraw-Hill Dictionary of Scientific and Technical
`Terms, Sixth Edition (2003). Each oneis classified according to the field with
`which it is primarily associated. The pronunciation of each term is provided
`along with synonyms, acronyms, and abbreviations where appropriate. A guide
`to the use of the Dictionary is included, explaining the alphabetical organization
`of terms, the formatof the book, cross referencing, and how synonyms,variant
`spellings, abbreviations, and similar information are handled. A pronunciation
`key is also provided to assist the reader. An extensive appendix provides
`conversion tables for commonly used scientific and technical units as well
`as charts, a “family tree” of programming languages, andlistings of useful
`mathematical, engineering, and scientific data, laws, and equations.
`
`It is the editors’ hope that this dictionary will serve the needs of scientists,
`engineers, specialists in information technology, students, teachers, librarians,
`and writers for high-quality information, and thatit will contribute to scientific
`literacy and communication
`
`MarkD. Licker
`Publisher
`
`
`
`
`
`7
`
`

`

`Staff
`
`
`MarkD. Licker, Publisher—Science
`
`Elizabeth Geller, Managing Editor
`Jonathan Weil, Senior Staff Editor
`David Blumel, Staff Editor
`Alyssa Rappaport, Staff Editor
`Charles Wagner, Digital Content Manager
`Renee Taylor, Editorial Assistant
`
`Roger Kasunic, Vice President—Editing, Design, and Production
`
`Joe Faulk, Editing Manager
`Frank Kotowski, Jr., Senior Editing Supervisor
`
`Ron Lane, Art Director
`
`Thomas G. Kowalezyk, Production Manager
`Pamela A. Pelton, Senior Production Supervisor
`
`Henry F. Beechhold, Pronunciation Editor
`Professor Emeritus of English
`Former Chairman, Linguistics Program
`The College of New Jersey
`Trenton, New Jersey
`
`vi
`
`
`
`8
`
`

`

`How to Use the Dictionary
`
`ALPHABETIZATION. The terms in the McGraw-Hill Dictionary of Electrical and
`Computer Engineering are alphabetized on a letter-by-letter basis; word spacing,
`hyphen, comma, and solidus in a term are ignored in the sequencing. For
`example, an ordering of terms would be:
`
`absolute-value computer
`absolute vector
`accuracy control system
`ac/dc receiver
`
`airborne radar
`air capacitor
`
`Thebasic formatfor a defining entry provides the term in boldface,
`FORMAT.
`the field in small capitals, and the single definition in lightface:
`
`term [FIELD] Definition.
`
`A field may be followed by multiple definitions, each introduced by a boldface
`number:
`
`term [FIELD] 1. Definition, 2. Definition. 3. Definition,
`
`A term mayhavedifinitions in two or morefields:
`
`term [commun] Definition.
`
`{computsci] Definition
`
`A simple cross-reference entry appears as:
`
`term See another term.
`
`A cross reference may also appear in combination with definitions:
`
`term [commun] Definition.
`
`(computsci| See another term
`
`CROSS REFERENCING.Across-reference entry directs the user to the
`defining entry. For example, the user looking up “chroma band-pass amplifier”
`finds:
`
`chroma band-pass amplifier
`
`See burst amplifier
`
`The user then turns to the “B" terms for the definition, Cross references are also
`made from variant spellings, acronyms, abbreviations, and symbols.
`
`ACK See acknowledge character.
`A-O-I gate See AND-OR-INVERTgate
`bps
`See bit per second
`chip See microchip.
`
`
`
`
`
`9
`
`

`

`ALSO KNOWNAS..., etc. A definition may conclude with a mention of
`a synonym of the term, a variant spelling, an abbreviation for the term, or
`other such information, introduced by “Also known as ...,” “Also spelled ...,”
`“Abbreviated ...," “Symbolized ...," “Derived from ....” When a term has more
`than onedefinition, the positioning of any of these phrases conveys the extent
`of applicability. For example:
`
`term {comput sci] 1. Definition. Also known as synonym. 2. Definition.
`Symbolized T.
`
`In the above arrangement, “Also known as ...” applies only to the first defi-
`nition; “Symbolized ...” applies only to the second definition.
`
`term [comMuN] 1. Definition. 2. Definition.
`Also known as synonym.
`
`[comput sci] Definition.
`
`In the above arrangement, “Also known as ...” applies only to the secondfield.
`
`term [commun] Also known as synonym. 1. Definition. 2. Definition.
`[compuTscl] Definition.
`
`In the above arrangement, “Also known as...” applies only to both definitions
`in the first field.
`
`term Also known as synonym.
`[comput sci] Definition.
`
`[commun] 1. Definition. 2. Definition.
`
`In the above arrangement, “Also known as...” applies to all definitions in both
`fields.
`
`viii
`
`
`
`10
`
`
`
`10
`
`

`

`Fields and Their Scope
`
`[COMMUN] Communications—Thescience and technology by which information
`is collected from an originating source; converted into a form suitable for
`transmission, transmitted over a pathway such as a satellite channel, under-
`water acoustic channel, telephone cable, or fiber-optic link; and reconverted
`into a form suitable for interpretation by a receiver.
`
`[COMPUTscl] Computer sclence—Thestudy of computing, including computer
`hardware, software, programming, networking, database systems, information
`technology, interactive systems, and security.
`
`|CONT Sys] control systems—The study of those systems in which one or more
`outputs are forced to change in a desired manneras time progresses.
`
`[ELEC] electricity—The science of physical phenomena involving electric
`charges and their effects when at rest and when in motion.
`
`[ELECTROMAG] electromagnetism—The branch of physics dealing with the
`observations and lawsrelating electricity to magnetism, and with magnetism
`produced by an electric current.
`
`[ELECTR] electronics—The technological area involving the manipulation
`of voltages and electric currents through the use of various devices for the
`purpose of performing some useful action with the currents and voltages;
`this field is generally divided into analog electronics, in which the signals to
`be manipulated take the form of continuous currents or voltages, and digital
`electronics, in which signals are represented bya finite set of states.
`
`[ENG] engineering—The science by which the properties of matter and the
`sources of powerin nature are madeuseful to humans in structures, machines,
`and products.
`
`[ENG ACOUS| engineering acoustics—The field of acoustics that deals with the
`production, detection, and control of soundbyelectrical devices, including the
`study, design, and construction of such things as microphones, loudspeakers,
`sound recorders and reproducers, and public address sytems.
`
`[GEOPHYS] geophysics—The branch of geology in which the principles and
`practices of physics are used to study the earth and its environment, that is,
`earth, air, and (by extension) space.
`
`
`
`
`
`
`
`11
`
`11
`
`

`

`[MATER] materials—A multidisciplinary field concerned with the properties
`and usesof materials in terms of composition, structure, and processing.
`
`and
`quantity,
`shape,
`of
`study
`deductive
`|MaTH| mathematics—The
`dependence;
`the two main areas are applied mathematics and pure
`mathematics, the former arising from the study of physical phenomena, the
`latter involving the intrinsic study of mathematical structures.
`
`|NAV| navigation—The science or art of directing the movement of a craft,
`such as a ship, small marine craft, underwater vehicle, land vehicle, aircraft,
`missile, or spacecraft, from one place to anotherwith the assistance of onboard
`equipment, objects, or devices, or of systems external to the craft.
`
`{optics] optics—The study of phenomena associated with the generation,
`transmission, and detection of electromagnetic radiation in the spectral range
`extending from the long-wave edge of the x-ray region to the short-wave edge
`of the radio region; and thescience oflight.
`
`[PHYS] physics—The science concerned with those aspects of nature which
`can be understoodin terms of elementary principles and laws.
`
`|souip staTe| solid-state physics—The branch of physics centering on the
`physical properties of solid materials;it is usually concerned with the properties
`of crystalline materials only, but
`it
`is sometimes extended to include the
`properties of glasses or polymers.
`
`[stat] statistics—The science dealing with the collection, analysis,
`pretation, and presentation of masses of numericaldata.
`
`inter-
`
`|sYS ENG] systems engineering—The branch of engineering dealing with the
`design of a complex interconnection of many elements(a system) to maximize
`an agreed-upon measure of system performance.
`
`F
`
`12
`
`12
`
`

`

` Pronunciation Key
`
`Consonants
`b
`as in bib, dribble
`ch
`as in charge, stretch
`as in dog, bad
`as in fix, safe
`as in good, signal
`as in hand, behind
`as in joint, digit
`as in cast, brick
`as in Bach (usedrarely)
`as in loud, bell
`as in mild, summer
`as in new, dent
`indicates nasalization of
`preceding vowel
`asinring, single
`asin pier,slip
`as in red, scar
`as in sign, post
`as in sugar, shoe
`asin timid, cat
`as in thin, breath
`as in then, breathe
`asin veil, weave
`asin zoo, cruise
`as in beige, treasure
`
`r sI
`
`SBp3TiWwx~—a4™oO
`
`yn
`p
`
`t
`
`v
`Z
`
`Vowels
`as in bat, that
`as in bait, crate
`as in bother, father
`as in bet, net
`as in beet, treat
`as in bit, skit
`as in bite, light
`as in boat, note
`as in bought, taut
`as in book, pull
`as in boot, pool
`as in but, sofa
`as in crowd, power
`as in boil, spoil
`as in formula, spectacular
`as in fuel, mule
`
`—™OmDO@Oow
`orcoo7!
`—<<-©oo2
`
`Semivowels/Semiconsonants
`Ww
`as in wind, twin
`as in yet, onion
`
`y
`
`Stress (Accent)
`precedessyllable with primary
`stress
`
`precedessyllable with secondary
`stress
`
`precedessyllable with variable
`or indeterminate primary/
`secondary stress
`
`Syllabication
`Indicates syllable boundary
`when following syllable is
`unstressed
`
`Xl
`
`
`
`13
`
`13
`
`

`

`
`
`14
`
`14
`
`

`

`abnormal propagation=(comMMUN| Phenomena of ;
`
`a See ampere.
`abfarad |ELEc|A unit of capacitance in the
`A See ampere
`electromagnetic centimeter-gram-second sys-
`aQ See abohm
`tem equal
`to 10°
`farads. Abbreviated aF.
`{ ab'far-ad }
`(aQ)-1
`See abmho
`A+ Sve A positive
`abhenry (ELEc} A unit of inductancein the elec-
`aA See abampere
`tromagnetic centimeter-gram-second system of
`aA/cm?
`Sve abampere per square centimeter
`units which is equal to 10-9 henry. Abbreviated
`AANDNOTB gate SeeANDNOTgate.
`{'aannét
`aH.
`{ab'hen-ré}
`'bé ,gat }
`able
`(compur sci| A name for the hexadecimal
`[ELec] The unit of electric current
`abampere
`digit whose decimal equivalent is 10.
`{
`'a-bal }
`in the electromagnetic centimeter-gram-second
`abmho [ELEc| A unit of conductancein the elec-
`system;
`| abampere equals 10 amperes in the
`tromagnetic centimeter-gram-second system of
`absolute meter-kilogram-second-ampere sys-
`units equal to 10° mhias. Abbreviated (aQ)~!.
`tem Abbreviated aA. Also known asBi; biot.
`Also known as absiemens (aS).
`{ 'ab,m6 }
`{ ab'am-pér }
`Abneylevel Seeclinometer
`{'ab-né ‘lev-al }
`{ELEc] The unit
`abampere per square centimeter
`abnormal glow discharge
`[ELEcTR| A discharge
`of current density in
`the electromagnetic
`of electricity in a gas tube at currents somewhat
`centimeter-gram-second system. Abbreviated
`higher than thoseof an ordinary glow discharge,
`aA/em?.
`{ab'am-pér par 'skwer'sen-ta,méd-ar}
`at which point the glow covers the entire cathode
`A battery |ELEcTR| The battery that supplies
`and the voltage drop decreases with increasing
`power forfilaments or heaters of electron tubes
`current.
`{ ab'nér-mal ,gl6 ‘dis-charj}
`in battery-operated equipment.
`{'a ,bat-a-ré }
`
`abbreviated dialing
`|cOoMMUN] A feature which
`unstable or changing atmospheric or janospheric
`requires less than the usual number ofdialing
`conditions acting upon transmitted radio waves,
`operations to connect two or more subscribers
`preventing such waves
`from following their
`{ o'bré-vé.ad-ad'd7-lin }
`normal path,
`thereby causing difficulties and
`ABC See automatic brightness control
`disruptions of communications.
`{ ab'nor-mal
`abcoulomb [ELEC] The unit of electric charge
`\prap-a'ga-shan]
`in the electromagnetic centimeter-gram-second
`(comput sci} An element of
`abnormal statement
`system, equal to 10 coulombs. Abbreviated aC
`a FORTRAN V (UNIVAC) program which specifies
`{ ab'kii-lom ]
`that certain function subroutines mustbe called
`|ELEc] Inthe electromag-
`abcoulomb centimeter
`every time they are referred to.
`{ ab'ndor-mal
`netic centimeter-gram-second system of units,
`‘stat-mant }
`the unit ofelectric dipole moment, Abbreviated
`abohm [eLec| The unit ofelectrical resistance in
`aCcm,
`{ ab'kii-l6m 'sen-ta,méd-ar}
`the centimeter-gram-second system;
`| abohm
`[ELEC] The
`abcoulomb per cuble centimeter
`equals 10-? ohm in the meter-kilogram-second
`electromagnetic centimeter-gram-secondunit of
`system, Abbreviated aQ.
`{ a'bém}
`volume density of charge. Abbreviated aC/cm3
`abohm centimeter
`[ELEc| The centimeter-gram-
`| ab'kis Gm par 'kyd-bik 'sen-ta,méd-ar }
`second unit of resistivity. Abbreviated aQ@cm
`abeoulomb per square centimeter
`|[cLec| The
`{ a'bom 'sen-ta,mé-dar}
`electromagnetic centimeter-gram-second unit
`abort
`[COMPUT sci] To terminate a procedure,
`of surface density of charge, elestric polariza-
`such as the running of acomputer program or the
`tion, and displacement. Abbreviated aC/cm?
`printing ofadocument, while itis still in progress
`(ab'ki-l6m par skwer ‘sen-tayméd-ar |
`{ o'bort }
`abeam Sevonthe beam
`{a'bém |
`abort branch§|conT sys| A branching instruction
`abend=[comeur sci] An unplanned program ter-
`in the program controlling a robot that causes a
`mination that occurs when a computeris directed
`test to be performed on whether the tool-center
`to execute an Instruction or to process informa-
`point is properly positioned, and to reposition it
`tion thatit cannot recognize. Also known as blaw
`if it drifts out of the acceptable range
`up; bomb; crash.
`{
`'ab-end }
`ibranch}
`
`{ a'bort
`
`15
`
`

`

`See
`
`absorption
`
`|compuT sci] A com-
`absolute-vatue computer
`[ELEC] 1. Assembly in a single
`AB power pack
`puter that processes the values of the variables
`unit of
`the A battery and B battery for a
`ratherthantheirincrements
`{‘ab-sa,lit'val-yii
`battery-operated vacuum-tubecircuit.
`2. Unit
`kam'pyiid:or|
`that supplies the necessary A and Bdirect-current
`absolute vector=|compuTscl] In computer graph-
`voltages from an alternating-current source of
`ics, a vector whose end points are given in
`power
`{ ajbé 'pau-ar ,pak }
`absolute coordinates,
`{
`'ab-sa,liit 'vek-tor ]
`abrupt Junction
`§(ELectR| A pn junction in which
`absorbed charge
`[ELEc| Charge on a capacitor
`the concentration of impurities changes sud-
`which arises only gradually when the potential
`denly from acceptors to donors.
`{ a'brapt
`difference across the capacitor is maintained,
`‘onk- shan }
`due to gradual orientation of permanent dipolar
`function occurring
`abs
`[comput sci] A special
`molecules—{ ab'sorbd ‘charj }
`in ALGOL, which yields the absolute value, or
`absorber
`|[ELECTR| A material or device that
`modulus, ofits argument,
`takes up and dissipates radiated energy; may be
`absiemens See abmho.
`{ ab'sé-monz}
`used to shield an object from the energy, pre-
`absolute address
`[compusci] The numerical
`vent
`reflection of the energy, determine the
`identification of each storage location which
`nature of the radiation, or selectively transmit
`is wired permanently into a computer by the
`one or more components of
`the radiation
`manufacturer,
`('ab-sa,liit a'dres }
`{ ab'sor-bar }
`absolute addressing
`[comput sci| The identi-
`absorber
`control
`fication of storage locations
`in a computer
`{ ob'sor-bar kon'trél }
`program by their physical addresses,
`{ ‘ab-so
`absorption
`[ELEC] The property of a dielectric in
`ltt o'dres-in }
`a capacitor which causes a small charging current
`absolute category rating mean opinion score
`to flow after the plates have been brought up
`[COMMUN | Methodology for subjectively testing
`to the final potential, and a small discharging
`audio quality where participants are presented
`current to flow after the plates have been short-
`with sound samples, one at a time, and are
`circuited, allowed to stand for a few minutes, and
`asked to grade them on a 5-point scale, For the
`NRSC FM IBOCtests, the MOS scale used was
`short-circuited again Also known as dielectric
`soak,
`[ELECTROMAG] Taking up of energy from
`5 = excellent, 4 = good, 3 = fair, 2 = poor,
`| =
`radiation by the medium through which the
`bad. Abbreviated ACR-MOS.
`{
`jab-sa,lut kad-
`radiation is passing,
`{ ob'sorp-shan }
`2,g0ré rad-ig mén 'o-'pinsyan ,skGr }
`absorption circuit
`[ELEcTR| A series-resonant
`absolute cellreference=[{compuT sci] A cell refer-
`circuit used to absorb power at an unwanted
`ence used in a formula in a spreadsheet program
`signal frequency by providing a low impedance
`that does not change whenthe formula is copied
`to ground at
`this frequency
`[ ob'sorp-shon
`ormoved.
`{ {ab-sa,liit 'sel ,refrans }
`'sar-kat |
`absolute code=|compuT sci| A code used when
`the addresses in a program are to be written
`absorption control
`See absorption modulation
`{ ob'sorp-shon kon'trdl }
`in machine language exactly as they will appear
`absorption current
`(ELEC| The component of a
`whentheinstructions are executed by the control
`dielectric current that is proportional to the rate
`circuits.
`{
`'ab-sa,ltit'kdd }
`of accumulation of electric charges within the
`absolute efficiency
`[ENG Acous| The ratio of the
`dielectric.
`{ ob'sorp-shon'kor-ont }
`power output of an electroacoustic transducer,
`underspecified conditions, to the power output
`absorption fading
`|CoMMUN| Slowtype of fad-
`of an ideal electroacoustic transducer,
`{ 'ab-sa
`ing, primarily caused by variations in the absorp-
`
`tit o'fish-on-sé } tion rate along the radio path={ ab'sorp-shon
`'fad-in }
`absolute electrometer
`|ELEC] A very precise type
`of attracted disk electrometer in which the at-
`the
`[COMMUN|That part of
`absorption loss
`transmission loss due to the dissipation or con-
`traction between two disks is balanced against
`version of either sound energyor electromagnetic
`the force of gravity.
`{
`‘ab-soliit 9o,lek'tram-
`energy into other forms of energy, either within
`od-or }
`the medium or attendant upon a reflection
`absolute galn of an antenna=|ELECTROMAG] Gain
`( ob'sorp-shon lds|
`in a given direction when the reference antenna
`is an isotropic antenna isolated in space, Also
`absorption meter
`[(ENG| Aninstrument designed
`to measure the amount of
`light
`transmitted
`known asisotropic gain of an antenna,
`([‘ab-sa
`slut gan ov on an'ten-a }
`through a transparent substance, using a pho-
`absolute index of refraction Svc index of refrac-
`tocell or other light detector
`{ ob'sorp-shon
`‘méd-or |
`tion
`[
`'ab-sa,liit 'in,deks ov ri'frak-shon }
`[ELECTR] A system of
`absorption modulation
`absolute Instructlon
`§|compuT sci] A computer
`instruction in its final form,
`in which it can be
`amplitude modulation in which a variable-
`impedance device is
`inserted in or coupled
`executed,
`{ ‘ab-sa,fit in'strak-shon ]
`to the output circuit of the transmitter. Also
`absolute programming
`(comput sci] Program-
`known as absorption control; loss modulation
`ming with the use of absolute code.
`( ‘ab-so
`( ab'sorp-shon mdd-yii'la-shan }
`iit 'prd-gram-in }
`absolute refractive constant See index of refrac-
`absorption wavemeter
`[ELECTR] A frequency- or
`wavelength-measuring instrument consisting of
`tion,
`{ ‘ab-sa,lit ri'frak-tiv 'kan-stant }
`
`
`
`control
`
`AB powerpack
`
`16
`
`16
`
`

`

`access-control register
`
`{ ak'sep-tar im
`
`a calibrated tunable circuit and a resonance
`[ELECTR] The voltage be-
`acceleration voltage
`indicator
`{ ab'sorp-shon 'wav,méd-ar}
`tween a cathode and accelerating electrode of
`sci| The
`abstract
`automata
`theory [comput
`an electron tube.
`{ ak,sel-a'ra-shan 'vGl-taj }
`mathematical theory which characterizes auto-
`accentuation [ELECTR] The enhancementofsig-
`mata bythree sets: input signals, internal states,
`nal amplitudes in selected frequency bands
`and output signals; and two functions:
`input
`with respect to other signals.
`( ak,sen-cha'wa-
`shan }
`functions and output
`functions
` {'abz-trakt
`o'tam-a-ta 'thé-o-ré }
`[ELEcTR| A circuit that provides for
`accentuator
`abstract data type
`[comput sci| A mathematical
`the first part of a process for increasing the
`model which may be used to capture the essen-
`strength of certain audio frequencies with respect
`tials of a problem domain in order to translate
`to others,
`to help these frequencies override
`noise or to reduce distortion. Also known as
`it into a computer program; examples include
`queues,
`lists, stacks,
`trees, graphs, and sets
`accentuator circuit.
`{ ak'sen-cha,wad-ar}
`accentuatorcircult
`See accentuator.
`{ ak'sen-
`Abbreviated ADT
`—_{
`'abz-trakt 'dad-a ,tip }
`abvolt
`[ELEC| The unit of electromotive force
`cha,wad-or 'sar-kat}
`accept
`|CoMPUT Sci] A data transmission state-
`in the electromagnetic centimeter-gram-second
`ment which is used in FORTRAN when the
`system; | abvolt equals 107" volt in the absolute
`computeris in conversational mode, and which
`meter-kilogram-second system. Abbreviated aV
`{'ab,valt }
`enables the programmer to input, through the
`[ELEC] In the electromag-
`abvolt per centimeter
`teletypewriter, data the programmer wishes
`netic centimeter-gram-second system of units,
`stored in memory,
`{ ak'sept }
`the unit of electric field strength. Abbreviated
`acceptor
`[SOLID STATE] An impurity element that
`increase the number of holes in a semiconduc-
`aV/em.
`_{
`'ab,vGlt par 'sen-ta,méd-ar }
`abwatt
`[ELEC] The unit ofelectrical power in the
`tor crystal such as germanium orsilicon; alu-
`centimeter-gram-second system; | abwatt equals
`minum, gallium, and indium are examples. Also
`| watt
`in the absolute meter-kilogram-second
`known as acceptor impurity; acceptor material
`system,
`{ ‘ab,wat }
`{ ak'sep-tar}
`ac See alternating current
`[ELECTR| A series-resonant cir-
`acceptor clrcult
`aC See abcoulomb
`cuit that has a low impedanceat the frequency
`ACAS See airbornecollision avoidance system
`to which it
`is tuned and a higher impedance
`accelerated graphics port
`(comput sci] A per-
`at
`all other
`frequencies,
`{ ak'sep-tor
`‘sar.
`sonal computer graphics bus that transfers data
`kat }
`atagreaterratethanaPClbus,
`{ ak,sel-a,rad-ad
`acceptor Impurlty See acceptor,
`‘graf-iks ,port }
`‘pylir-a-dé }
`|ELEc] A test of the serviceabil-
`accelerated test
`acceptor matertal
`ity of an electric cable in use for some time
`'tir-é-al }
`access
`|COMPUT SCi| The reading of data from
`by applying twice the voltage normally carried,
`{ ak'sel-ar,d-dad 'test}
`storage or the writing of data into storage.
`{'ak
`ses }
`electrode
`|ELEcTR| An_
`accelerating electrode
`access arm [COMPUT Scl| The mechanical device
`used in cathode-ray tubes and other electron
`tubes to increase the velocity of the electrons
`which positions the read/write head on a mag-
`that contribute the space current or form a beam
`netic storage unit,
`{'ak,ses ,4rm }
`access code [COMMUN] 1. Numeric identification
`( ak'sel-ar,dd-in i'lek,trGd }
`accelerating potential
`[ELecTR| The energy po-
`for internetwork orfacility switching,
`2. The pre-
`liminary digits that a user must dial! to be con-
`tential in electron-beam equipmentthat imparts
`additional speed and energy to the electrons
`nected through an automatic PBX to the serving
`{ ak'sel-ar,ad-in pa'ten-shal }
`switching center.
`(COMPUT sci] A sequence of
`characters which a user must enterintoa terminal
`acceleratingrelay |ELEc] Any relay that is used to
`assist in starting a motoror increasing its speed.
`in order to use a computer system.
`{[ ‘ak,ses
`{ ak'sel-a,radvin 'ré,la }
`ikd ]
`[(CONTSyYS| The ratio
`acceleration-error constant
`|compuTsci| A restriction on the
`access control
`of the acceleration of a controlled variable of a
`operations that a user of a computer system
`may perform onfiles and other resources of the
`servomechanism to the actuating error when the
`actuating error is constant.
`( ak,sel-a'ra-shan
`system.
`{'‘ak,ses kan,trdl }
`‘er-or 'kdn-stont}
`access-controllist
`(comput sci] A column of an
`|[ELEc| A switch that opens or
`acceleration switch
`access matrix, containing the access rights of
`closesin the presenceofacceleration that 0 exceeds
`various users of a computer system to a given
`acertain value.
`{ ak,sel-o'ra-shan ,swich |
`file or other resource of the system.
`_{
`'ak,ses
`
`acceleration time=|compuT sci] The time required kon,trol list }
`access-control mechanism See reference moni-
`for a magnetic tape transport or any other
`mechanical device to attain its operating speed
`tor
`{ jakses kon'trdl |me-ka-ni-zam }
`{ ak,sel-a'ra-shon ,tim }
`access-control register
`|comPuT sci A storage
`to
`[ENG] The degree
`acceleration tolerance
`device which controls the word-by-word trans-
`which personnel or equipment withstands accel-
`mission over a given channel.
`{ ‘ak,ses kan'trdl
`eration.
`{ ak,sel-o'ré-shan 'tal-ar-ans }
`iTej-a-star}
`
`{ ak'sep-tar mo
`
`mwiw=tw
`
`See acceptor.
`
`
`
`17
`
`

`

`access-conirol words
`
`battery
`
`[ELECTR] The time from
`accommodation time
`[COMPUT scl] Permanently
`access-control words
`the first electron to the
`the production of
`channeling
`transmitted
`wired
`instructions
`production of a steadyelectric discharge in a gas.
`words into reserved locations.
`{ak,ses kon'tral
`{ a,kam-a'da-shon ,ttm }
`wwardz |
`accordion cable
`{eLEc| A flat, multiconductor
`['ak,ses fap}
`access gap See memorygap.
`cable prefolded into a zigzag shape and used
`access line
`|COMMUN| Four-wire circuit between
`to make connections to movable equipment
`a subscriber or a local PBX to the serving swit-
`such as a chassis mounted on pulloutslides.
`ching center.
`|‘ak.ses lin}
`(a kord- én 'ka-bal }
`access management
`[compuT sci| The use of
`[COMPUT scl] A set of spe-
`accounting package
`techniques to allow various components of a
`clal routines that allow collection of information
`computer's operating system to be used only
`about the usage level of various componentsof
`by authorized personnel,
`{
`‘akses
`,man-ij-
`a computer system by each production program
`mont}
`(o'kaunt-ig 'pak-ij }
`[comput scl] A method of repre-
`access matrix
`in
`accumulator
`|coMPUT SCl| A specific register,
`senting discretionary authorization information,
`the arithmetic unit of a computer, in which the
`with rows representing subjects or users of the
`result of an arithmetic or logical operation is
`system, columns corresponding to objects or
`formed; here numbers are added or subtracted,
`resources of the system, andcells (intersections
`and certain operations such as sensing, shifting,
`of rows and columns) composed of allowable
`and complementing are performed, Also known
`operations that a subject may apply to an object.
`as accumulator register; counter
`[ELEC|
`See
`(‘ak,ses ,ma-triks }
`storage battery.
`{ o'kyii:myo,lad-or}
`sci] The mecha-
`access mechanism [comput
`accumulator battery
`See
`storage
`nism af positioning reading or writing heads onto
`{ o'kyii-mya,lad-ar 'bad:-a-ré}
`the required tracks of amagnetic disk.
`{'ak,ses
`§{CompPuT scl] An
`accumulator Jump instruction
`'mek-o,niz-om }
`instruction which programs a computer to ignore
`|COMMUN| The procedures re-
`access method
`the previously established program sequence
`quired to obtain access to a communications
`depending on the status of the accumulator.
`network,
`(COMPUT sci| A set of programming
`Also known as accumulator transfer instruction,
`routines whichlinks programs and the data that
`{ a'kyi-myo,ladar jamp in'strok-shon }
`these programstransfer into and out of memory
`{ a'kyi-
`accumulator register Sec accumulator.
`{ 'ak,ses ,meth-od }
`myo, lad-ar 'rej-o-stor }
`sci}A programming
`access mode
`[comput
`accumulator shift Instruction
`|compuT sci|A
`clause in COBOL which is required when using
`computer instruction which causes the word ina
`a random-access device so that a specific record
`register to be displaced-a specified numberofbit
`maybe read out of or written into a mass storage
`positions to the leftorright.
` { o'kyi-mya,lad-ar
`bin.
`{'ak,ses mGd }
`‘shift in'strak-shan }
`to
`access privileges
`[comput sci| The extent
`accumulatortransfer Instruction See accumulator
`which a user of a computer in a network is
`allowed to use and read, write to, and execute
`jump instruction.
`( a‘kyii:mya,lad-or 'trans-for
`in'strak:shon }
`files in other computers in the network.
`{ ‘ak
`scl] Any
`syste