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`Published by
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`lEEE Press
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`1
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`THOMAS SWAN 2003
`Finisar v. Thomas Swan
`|PR2014-00461
`
`1
`
`THOMAS SWAN 2003
`Finisar v. Thomas Swan
`IPR2014-00461
`
`

`

`
`
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`
`
`
`Trademasks and disclaimers
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`Copyright © 2000 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published
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`
`Tradel
`
`The A1
`
`Abstre
`
`Non-I}
`
`Library of Congress Cataloging—impubhcafion Data
`
`IEEE 100 1 “1° “thoritative dictionary of IEEE standards terms.—7th ed.
`p. cm.
`‘
`‘
`
`ISBN 0-73812601-2 (paperback : alk. paper)
`1‘. Eleomg‘qngineedng‘bictiottafies. 2. Eleclxomcs_Dictiox1aIies. 3- Computer
`-_\ engineenng~D1ctionaIies 4, Elecm‘c engineering—Acronyms. 5. Electronics—Acronyms.
`‘ 6- Computer englneering—Amonyms: 1. Institute of Electrical and ElectronicsEngineers.
`TK9 .128 2000
`_
`“
`7N
`,
`c ,
`621.3'03—dc21
`
`00050601
`
`The Au.
`
`
`
`
`
`
`2
`
`

`

`
`
`wed. Published
`
`'mwise, without
`
`'ment [0 users,
`‘65 not assume
`her such error
`it
`
`: and opinions
`
` union is subject
`
`is publication,
`the assistance
`
`050601
`
`Contents
`
`Introduction
`
`
`
`How to Use This Dictionary
`
`Categories
`
`Trademarks
`
`The Authoritative Dictionary of IEEE Standards Terms
`
`Abstracts and Sources
`
`Non-IEEE Standards Sources
`
`1294
`
`1351
`
`The Authoritative Dictionary of IEEE Standards Terms
`
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`
`3
`
`

`

`
`
`chadded
`
`157
`
`channel
`
`
`
`(z) The bit of material resulting from punching a hole in a
`paper card or tape. Synonym: chip.
`(C) 610i10—1994w
`chaddEd Pertaining to the punching of tape in which chad re-
`sults.
`(C) [20], [85]
`chadless Pertaining to the punching of tape in which chad does
`not result.
`(MIL/C) [2], [85], [20]
`chadless tape (1) A punched tape wherein only partial perfo-
`ration is completed and the chad remains attached to the tape.
`,
`(1A)
`[61]
`(2) Perforated tape that has been punched in such a way that
`chad is not formed.
`(C) 610,10—1994w
`chaff Strips of lightweight metal or metallized material that are
`dispensed in large numbers (bundles) so as to simulate a true
`target, or, more usually, to create a large clutter signal that
`masks the detection of wanted targets. Notes: 1. Each bundle
`may contain thousands of individual reflectors whose lengths
`are related to the wavelength of the radar. 2. Chaff for use at
`HF and VHF frequencies is Sometimes called “rope."
`3. During WWII, chaff was called “window” in Great Britain
`and “Dueppel” in Germany.
`(AES) 6864997
`chafing strip See: drive strip.
`chain (1) (navigation aids) A network of similar stations op«
`crating as a group for determination of position or for fur—
`nishing navigational information.
`(AES/GCS) l72-l983w
`(2) (mathematics of computing) A sequence of bits used to
`construct a binary code. See also: chain code.
`(C) 1084-1986w
`(3) (data management) See also: linked list.
`(C) 610.5—1990w
`chain binder See: binder load.
`chain code An arrangement in a cyclic sequence of some or all
`of the possible different 11-bit words in which adjacent words
`are related such that each word is derivable from its neighbor
`by displacing the bits one place to the left or right, dropping'
`the leading bit, and inserting a bit at the end. The value of
`the inserted bit needs only to meet the requirement that a word
`must not recur before the cycle is complete. For example, 000
`001010101011111110100 000.
`.
`.
`(C)
`[20], 1084-1986w, [85]
`chain-drive machine (elevators) An indirect~drivc machine
`having a chain asthe connecting means. See also: driving
`machine.
`(EEC/PE) [1191
`chained list (1) (software) A list in which the items may be
`dispersed but in which each item contains an identifier for
`locating the next item. Synonym: linked list. See also: list;
`identifier.
`(C/SE) 729—1983s
`(2) (data management) See also: linked list.
`(C) 610.5—1990w
`chain field See: link field.
`,
`-
`chain hoist See: hoist.
`chaining (1) A method for storing records in which each record
`has a link field that is used to access subsequent records.
`,
`(C) 610.5-1990w
`(2) A mode of interaction optionally used by a DSA that can-
`not perform an directory operation itself; the DSA chains by
`invoking a directory operation of another DSA and then re-
`laying the outcome to the original requester.
`(C/PA) 1328.2—1993w, 1326.2—1993w, 1327.2-1993w,
`1224.2—1993w
`chaining search A search in which each item contains a means
`for locating the next item to be considered in the search.
`(C) 610.5-1990W
`chain matrix The 2 X 2 matrix relating voltage and current at
`one port of a two—port network to voltage and current at the
`other port.
`.
`1,
`_.
`o,—
`_
`
`O W
`
`v,
`
`Network
`
`i2
`_.
`+0
`7
`O
`\/2
`chaln matrix
`‘
`
`l
`2
`(Y1 ) = (g g) (ll/1’
`
`(CA5) [13}
`
`chain printer An element printer in which the type slugs are
`carried by the links of a revolving chain, called a print chain.
`(C) 610.10-1994w
`
`chain tugger See: hoist.
`chain-type conveyor A conveyor using a driven endless chain .
`or chains, equipped with flights that operate in a trough and
`move material along the trough. See also: conveyor.
`(EEC/PE) (119]
`
`chair, boatswain See: boatswain's chair.
`chalking (1) (composite insulators) The powdered surface on
`weathersheds consisting of particles of filler resulting from
`ultraviolet exposure.
`(T&D/PE) 987—1985w
`(2) The development of loose removable powder at or just
`beneath a coating surface.
`(IA) [59]
`(3) The powdered surface on the polymeric insulator consist-
`ing of particles of filler resulting from ultraviolet exposure or
`leakage current activity.
`(PE/1C) 48—1996
`challenge (navigation aids) To cause an interrogator to transmit
`a signal which puts a tranSponder into operation. See also:
`interrogation.
`(AES/GCS) 172—1983w
`change control See: configuration control.
`change control board See: configuration control board.
`change detection An image processing technique in which the
`pixels of two registered images are compared to detect dif-
`ferences.
`(C) 610.4—1990w
`change dump A selective dump of those storage locations
`whose contents have changed since some specified time or
`event. Synonym: differential dump. See also: dynamic dump;
`snapshot dump; static dump; selective dump; memory dump;
`postmortem dump.
`(C) 610.12—1990
`ehange-of—frame alignment A state that occurs when an off—
`line framer realigns the receiver to the proper frame alignment
`signal. See also: out-of—fiame condition.
`,
`(COM/TA) 1007-1991:
`change of state (COS) A significant change (as defined by a
`particular system) in the condition of a point being monitored,
`for example, a change in flow rate, temperature, voltage, etc.
`Usually associated with dual-status (that is, alarm/normal
`conditions).
`(PE/SUB) 1379-1997
`change-over selector A device designed to carry, but not to
`make or break current, used in conjunction with a tap selector
`or arcing tap switch to enable its contacts, and the connected
`taps, to be used more than once when moving from one ex—
`treme position to the other.
`(PE/FR) C57.131-l995
`change recording See: nonretum-to-zero (change) recording.
`changeover switch A switching device for changing electric
`circuits from one combination to another. Note: it is usual to
`qualify the term “changeover switch” by stating the purpose
`.
`l
`i
`,
`.
`for which it is used, such as a series-parallel changeover
`swrtch, trolley-shoe changeover switch. etc, See also: multi<
`ple-unit control.
`(EEC/PE) [119]
`change transaction A transaction that causes information in a
`master file to be changed. See also: delete transaction; add
`transaction; update transaction; null transaction.
`(C) 6102-1987
`CHANHI Abbreviation for upper channel corresponding to the
`half—amplitude point of a distribution.
`(N135) 398-1972r
`CHANLO Abbreviation for lower channel corresponding to the
`half-amplitude point of a distribution.
`(GSD) 200-1975w
`Channel A control or data path established between two buses
`that allows information to flow from one bus to the other. The
`Channels specific to this standard are the CSR channels, the
`F2V and VZF data channels, the event channel, and the dual
`port memory Channel.
`(C/BA) 1014.1-1994W
`channel (1) (A) (electric communication) A single path for
`transmitting electric signals, usually in distinction from other
`parallel paths. (B) (electric communication) A band of fre—
`quencics. Note: The word “path" is to be interpreted in a
`broad sense to include separation by frequency division or
`time division. The term “channel” may signify either a one»
`way path, providing transmission in one direction only, or a
`
`
`
`
`
`
`
`
`
`
`
`4
`
`

`

`
`
`
`
`l
`il
`
`elm
`
`mnnch:
`
`Ch:
`
`ch
`ch
`
`ch
`
`cl
`cl
`
`channel address
`
`158
`
`channel groupings
`
`t
`
`
`
`
`
`two—way path, providing transmission in two directions.
`(EEC/PE) [119], 599—1985
`(A) A path along which signals can be sent, for example,
`(2)
`data channel, output channel. (B) The portion of a storage
`medium that is accessible to a given reading station. See also:
`track.
`(C) 162—1963
`(3) A combination of transmission media and equipment ca-
`pable of receiving signals at one point and delivering related
`signals at mother point. See also: information theory.
`(IT) 171-1953w
`(4) (illuminating engineering) An enclosure containing the
`_ ballast, starter, lamp holders, and wiring for a fluorescent
`lamp, or a similar enclosure on which filament lamps (usually
`tubular) are mounted.
`(EEC/IE) [126]
`(5) (nuclear power generating station) An arrangement of
`components and mgdules as required to generate a single pro-
`tective action signal when required by a generating station
`condition. A channel loses its identity where single protective
`action signals are combined.
`(PE/NP) 379*1994,338-1987r, 603-1998
`(6) (metal-nitride-oxide field-effect transistor) A surface
`layer of carriers connecting source and drain in an insulated—
`gate fieldieffect transistor (IGFET). This channel was formed
`by inversion with the help of a gate vdltage, or by the presence
`of charges in the gate insulator, or by deliberate doping of
`the region.
`(ED) 581-1978w
`(7) A band of frequencies dedicated to a certain service trans—
`,mitted on the broadband medium.
`(LM/C) 61071995, 802.3u-19953
`(8) (broadband local area networks) The bandwidth re-
`quired for the transportation of a signal. The bandwidth will
`vary according to the information being transported. A band
`of frequencies dedicated to a certain service transmitted on a
`broadband medium.
`(LM/C) 802.7-1989r
`(9) (speech telephony) A means of one-way or two-way
`transmission provided by a vendor between two defined in-
`terface points. (The customer can realize a connection by con-
`necting together channels from one or more vendors.) Notes:
`1. ”Provided by a vendor" means responsibility for the service
`and does not necessarily mean ownership of facilities.
`2. Channels are provided either dedicated or switched. A ded-
`icated channel may be a non-switched channel for the exclu-
`sive use of a customer for a contracted time period. A-
`switched channel may be a channel established (set up and
`released) under customer control. 3. A channel may consist
`of two or more equipment items, such as transmission facil-
`ities, switching systems, etc. See also: connection.
`(COM/FA) 823-1989w
`(10) A logically independent data path between two Func‘
`tions. Multiple channels can be used to reach different Func»
`tions or to represent
`independent
`instances of inter-unit
`communication (e.g:, X25 connections, I/O operations on
`different discs, datagrams to different network SAPS, etc.)
`Channels can either be provided by physically separate
`queues or by multiplexing a shared queue.
`(C/MM) 12121-1993
`(11) (A) A one—way path for transmission of signals between
`two or more points; for example, a data channel. See also:
`line; circuit; link. (B) In data transmission, either one-way
`path, providing transmission in one direction only, or two-
`Way path, providing transmission in two directions. Syno-
`nyms: path.
`(C) 610.7—1995
`(12) (A) A one-way path for transmission of signals between
`two or more points; for example, an output channel or a data
`channel. Synonyms: link; path; line. See also: circuit. (B) The
`portion of a storage medium that is accessible to a given read-
`ing or writing station, such as a track, or a band. (C) A two—
`way communications path between the central processor and
`Its peripheral devices.
`(C) 610.10-1994
`(13) The tester electronics associated with a digital input/out-
`put (1(0) pin that either drives or senses a particular node on
`the non under test (UUT).
`(SCCZO) 14454998
`
`(14) The data path from any transmitting MIC to the next
`downstream receiving MIC.
`(LM/C) 8802-54998
`(15) A single flow path for digital data or an analog signal,
`usually in distinction from other parallel paths. An [BEE
`1451.2 channel provides a path for a single commodity or
`logical state, cithcr real or virtual, using a single data model
`and a single set of physical units.
`(IM/ST) 14512-1997
`(16) An instance of medium use for the purpose of passing
`protocol data units (PDUs) that may be used simultaneously,
`in the same volume of space, with other instances of medium
`use (on other channels) by other instances of the same phys—
`ical layer (PHY), with an acceptably 10w frame error ratio
`due to mutual interference. Some PHYS provide only one
`channel, whereas others provide multiple channels. Examples
`of channel types are as shown in the following table:
`Single channel
`n-channe]
`Narrowband radio—
`Frequency division multiplexed channels
`frequency (RF)
`channel
`Baseband infrared
`
`Direct sequence spread spectrum (DSSS)
`with code division multiple access
`(C/LM) 8802414999
`(17) A physical or logical communication link to a single
`transducer or to a group of transducers considered as a single
`transducer.
`(IM/ST) 1451.1—1999
`(18) (overhead power lines) See also: frequency band.
`(T&D/PE) 539-1990
`‘
`(19) See also: communication channel.
`(SUB/PE) 999~l992w
`'
`channel address The portion of a full data transport address
`that specifies the channel to which the read or write is di—
`rected.
`(IM/ST) 14512—1997
`channel-attached terminal A terminal that is connected di—
`‘
`rectly to the computer by wires or cables. Synonym: locally-
`attached terminal. Contrast: link-attached terminal.
`(C) 610.10-1994w
`channel bank A device that multiplexes high—speed commu-
`nication circuits into lower—speed communication channels;
`used primarily to digitize analog voice transmission,
`(C) 610.7-1995
`channel-busy tone (telephone switching systems) A tone that
`indicates that a server other than a destination outlet is either
`busy or not accessible.
`(COM) 312<1977w
`channel calibration The adjustment of channel output such that
`it responds, with acceptable range and accuracy, to known
`values of the parameter that the channel measures, and the
`performance of a functional test.
`(PE/NP) 338—19871
`channel capacity (1) (data transmission) The maximum pos—
`sible information rate through a channel subject to the con—
`straints of that channel. Note: Channel capacity may be either
`per second or per symbol.
`(PE) 599-1985w
`(2) (software) The maximum amount of information that can
`be transferred on a given channel per unit of time; usually
`measured in bits per second orin baud. See also: memory
`capacity; storage capacity.
`(C) 610.12—1990
`channel check A qualitative assessment of performance carried
`out at designated intervals to determine if all elements of the
`channel are operating within their designated limits.
`(PE/N?) 338—19871'
`' channel failure alarm (power-system communication) A cir-
`cuit to give an alarm if a communication charmel should fail.
`See also: power-line carrier,
`(PE) S99-1985w
`channel group (data transmission) A number of channels re-
`garded as a unit. Note: The term is especially used to desig-
`nate part of a larger number of channels.
`(PE) 599-1985w
`channel groupings Manufacturer specifications that define the
`inherent relationships between the channels of amultichannel
`Smart Transducer Interface Module. This grouping informa»
`tion is not normally used by the Smart Transducer Interface
`Module itself. This information will normally be uscd by Net-
`work Capable Application Processor applications to properly
`compose human readable displays or in formulating other
`
`;
`
`
`
`
`
`5
`
`

`

`
`
`
`
`IKFer—tuvvu-.
`
`<.
`
`'uulwmgi—dfimpmmvuw
`
`V(DH—Hw
`
`group index
`
`497
`
`group index (fiber optics) (denoted N) For a given mode prop-
`agating in a medium of refractive index n, the velocity of
`light in vacuum, c, divided by the group velocity of the mode.
`For a plane wave of wavelength A, it is related thus to the
`refractive index:
`»
`
`N = n — Mdn/dh)
`
`See also: material dispersion parameter; group velogity.
`.
`(StleO) 812-1984w
`grouping (1) (facsimile) Periodic error in the spacing of re—
`corded lines. See also: facsimile signal.
`(COM) 168-1956w
`(2) (electroacoustics) Nonuniform spacing between the
`grooves of a disk recording.
`(SP) [32]
`group item See: data aggregate.
`group loop (analog computer) A potentially detrimental loop
`formed when two or more points in an electrical system that
`are nominally at group potential are connected by a conduct—
`ing path such that either or both points are not at the same
`ground potential.
`(C)
`l65-1977w
`group mark A mark that identifies the beginning or the end of
`a set of data; for example, a mark at the beginning of a block.
`(C) 610.10-1994w
`group operation The operation of all poles of a multipole
`switch device by one operating mechanism.
`(SWG/PE) C37.lUO-1992
`
`group path See: group path length.
`group path length For a pulsed signal traveling between two
`points in a medium, the product of the speed of light in vac—
`uum and the travel time of the pulse between the two points,
`provided the shape of the pulse is not significantly changed.
`(AP/PROP) 211-1997
`groups, commutating, set of (thyristor converter) Two or
`more commutating groups that have simultaneous commux
`tations.
`(lA/IPC) 444-1973w
`group-series loop insulating transformer (power and distri-
`bution transformers) An insulating transformer whose sec—
`ondary is arranged to operate a group of series lamps and/or
`a series group of individual-lamp transformers. See also: spe—
`cialty transformer.
`(PE/TR) C57.12.80-1978r, [57]
`group velocity (1) (A) (fiber optics) For a particular mode, the
`reciprocal of the rate of change of the phase constant with
`respect to angular frequency. Note: The group velocity equals
`the phase velocity if the phase constant is a linear function of
`the angular frequency. See also: group index; differential
`mode delay; phase velocity. (B) (fiber optics) Velocity of the
`signal modulating a propagating electromagnetic wave. See
`also: group index; phase velocity; differential mode delay.
`(StleO) 812-1984
`(2) (waveguide) Of a traveling wave at a single frequency,
`and for a given mode, the velocity at which the energy is
`transported in the direction of propagation.
`(MTT) 146-1980w
`(3) (of a traveling wave) The velocity of propagation of the
`envelope, provided that the envelope moves without signifi—
`cant change of shape. The magnitude of the group velocity is
`equal to the reciprocal of the rate of change of phase constant
`with angular frequency.
`(AP/PROP) 211—1997
`grout (rotating machinery) A very rich concrete used to bond
`the feet, sole plates, bedplate, or rail of a machine to its foun-
`dation.
`(PE) [9]
`grown junction (semiconductor) A junction produced during
`growth of a crystal from a melt. See also: semiconductor de-
`vice.
`(ED) 216-1960w
`GRP See: ground reference plane.
`GRS See: generic response spectra.
`G-scope A cathode—ray oscilloscope arranged to present a G-
`display.
`(ABS/RS) 686—1990 _
`
`guarded enclosure
`
`G/T ratio (of an antenna) The ratio of the gain to the noise
`temperature of an antenna. Notes: 1. Usually the antenna
`receiver system figure of merit is specified. For this case the
`figure of merit is the gain of the antenna divided by the system
`noise temperature referred to the antenna terminals. 2. The
`system figure of merit at any reference plane in the RF system
`is the same as that taken at the antenna terminals since both
`the gain and system noise temperature are referred to the same
`reference plane at the antenna terminals. Synonym: figure of
`. merit,
`(AP/ANT) 145—1983s’
`G2 drift (electronic navigation) A drift component in gyros
`(sometimes in accelerometers) proportional to the square of
`the nongravitational acceleration and caused by anisoelastic-
`ity of the rotor supports. Jargon. See also: navigation.
`(AES/RS) 68649825, [42]
`
`guarantee See: work permit.
`guard (1) (interference terminology) A conductor situated be-
`tween a source of interference and a signal path in such a way
`that interference currents are conducted to the return terminal
`of the interference source without entering the signal path.
`See also: interference.
`(PE/PSR) [6]
`(2) One or more conducting elements arranged and connected
`on an electrical instrument or measuring circuit so as to divert
`unwanted currents from the measuring means.
`(PE/TR) C57.lZ.90—1999
`guardband (1) (data transmission) A frequency hand between
`two channels whiCh gives a margin of safety against mutual
`interference.
`(PE) 599-1985w‘
`(2) (broadband local area networks) (channel) A desig-
`nated unoccupied portion of the frequency spectrum that ex—
`ists between two bccupied portions of the spectrum.
`(LM/C) 8017-1989:
`guard channel One or more auxiliary parallel processing chan~
`nels to control the main processing channel in order to reject
`interference that is partly in, but not centered on, the main
`channel. Note: Guard channels may be displaced in time
`'(range), Doppler frequency, carrier frequency, or angle.
`Sometimes called “guard gates,” “guard bands,” or “sidelobe
`blanking" (not cancellation). Guard channel is used against
`range gate stealers, velocity gate stealers, sidelobe jamming,
`and to enhance apparent angle resolution in identification,
`friend or foe (IFF). May use auxiliary displays. See also: si-
`delobe blanket.
`(ABS) 686-1997
`guard circle (disk recording) An inner concentric groove in—
`scribed, on disk records, to prevent the pickup from being.
`damaged by being thrown to the center of the record.
`(SP) [32]
`guarded (1) Covered, shielded, fenced, enclosed, or otherwise
`protected by means of suitable covers or casings, barrier rails
`or screens, mats, or platforms to remove the likelihood of the
`dangerous contact or approach by persons or objects to a point
`of danger.
`
`(NESC/IA/T&D/PC) 463—1993w, [86], C2.2—1960
`(2) Covered, fenced. enclosed, or otherwise protected, by
`means of suitable covers or casings, barrier rails or screens,
`mats or platforms, designed to limit the likelihood under nor-
`mal conditions, of dangerous approach or accidental contact
`by persons or objects. Note: Wires that are insulated but not
`otherwise protected are not normally considered to be
`guarded.
`(NESC) C2-1997
`guarded enclosure An enclosure in which all openings giving
`direct access to live or rotating parts (except smooth rotating
`surfaces) are limited in size by the structural parts or by
`screens, baffles, grilles, expanded metal, or other means to
`prevent accidental contact with hazardous pairs. The openings
`in the enclosure shall be such that they will not permit the
`passage of a rod larger than 12 mm (l/Z in) in diameter,
`except where the distance of exposed live parts from the guard
`is more than 102 mm (4 in); then the openings may be of
`such shape as not to permit the passage of a rod larger than
`19 m (3/4 in) in diameter.
`(IA/MT) 4571998
`
`
`
`
`
`
`
`
`6
`
`

`

`
`
`
`guarded input
`
`guarded input (Oscilloscopes) A shielded input where the
`shield is driven by a signal in phase with and equal in am-
`plitude to the input signal.
`(1M) 311-1970w
`guarded machine (rotating machinery) An open machine in
`which all openings giving direct access to live or rotating
`parts (except smooth shafts) are limited in size by the design
`of the structural parts, or by screens, grilles, expanded metal,
`etc, to prevent accidental contact with such parts. Such open<
`ings are of such size as not to permit the passage of a cylin—
`drical rod 1/2 inch in diameter, except where the distance
`from the guard to the live or rotating parts is more than 4
`inches: they are of such size as not to permit the passage of
`a cylindrical rod 3/4 inch in diameter. See also: asynchronous
`machine.
`(PE) [9]
`guarded release (telephone switching systems) A technique
`for retaining a busy condition during the restoration of a cir-
`cuit to its idle state.
`(COM) 312—1977w
`guard electrode (testing of electric power system compo-
`nents) One or more electrically conducting elements, ar-
`ranged and connected in an electric instrument or measuring
`circuit so as to divert unwanted conduction or displacement
`currents from, or confine wanted currents to, the measurement
`device.
`(PE/PSIM) [55]
`guard frequency A reserved area within a range of frequencies
`that separates two channels in a carrier system or frequency~
`derived channel.
`(C) 610.10-1994w
`guard-ground system (interference terminology) A combi-
`nation of guard shields and ground connections that protects
`all or part of a signal transmission system from common-
`mode interference by eliminating ground loops in the pro-
`tected part. Note: Ideally, the guard shield is connected to the
`source ground. The source is usually grounded also to the
`source ground by bonding of the transducer to the test body,
`The filter, signal receiver, etc., are floating with respect to
`their own grounded cases. This necessitates physically iso-
`lating the signal receiver and filter chassis from the cases and
`using isolation transformers in power supplies, or isolating
`input circuits from cases and using isolating input transform-
`ers. This arrangement in effect places the signal receiver and
`filter electrically at the source. By means of a similar guard,
`the load can be placed effectively at the source. See the figures
`below. See also: interference.
`guard shield (interference terminology) A guard that is in the
`form of a shielding enclosure surrounding all or part of the
`signal path. Note: A guard shield is effective against both
`capacitively coupled and conductively coupled interference
`whereas a simple guard conductor is usually effective only
`against conductively coupled interference. See also: guard-
`ground system; interference
`SIGNAL HECElVER GROUND SHlELD
`(CASEl
`GUARD SHlELD
`GUARD SHIELD
`/
`_______ a _l-——-~
`
`RECElVEH 1|
`
`
`SlGNAL
`
`'
`
`l
`
`}
`
`
`CEI
`SOURCE
`COMMONvMODE
`HE
`VER
`GROUND
`AC 0R DC
`
`URCE
`T
`ggouND
`
`[The guard shleld consists ofthe signal source shield (if
`present). the signal snield, the filter shield, and the signal
`receiver shleld.l
`ideal guard shleld
`
`
`
`
`
`498
`
`—
`
`GUARD SHlELD
`HIGHJMFEDANCE LEAD
`
`guided wave
`
`RECEIVER GROUND SHIELD (CASE)
`’ “— " _‘ ‘
`‘ _'
`
`
`SIGNAL
`RECEIVER
`
`
`
`
`
`
`
`
`clan, t
`
`. _ i
`L _________ a
`t ______
`SOURCE
`SOURCE
`?
`COMMON-MODE
`GROUND
`AC 0H DC
`
`C
`RE EIVER
`GROUND
`
`[Guard shield connections when connection at source is not
`convenient. When (Fls + RS’) << (R1 + RS), this arrangement
`causes common—mode current in the low-impedance lead, but
`protects the more critical hlgh-impedance lead from current
`flow]
`
`guard shield
`
`[6]
`(PE/PSR)
`guard signal A signal sent over a communication channel to
`make the system secure against false information by pre-
`venting or guarding against the relay operation of a circuit
`breaker or other relay action until the signal is removed and
`replaced by a tripping or permissive signal.
`(SWG/PE) C37.100—1992
`guard structure See: crossing structure.
`guard Wire A grounded wire erected near a lower~voltagc cir-
`cuit'or public crossing in such a position that a high (or
`higher) voltage overhead conductor cannot come into acci-
`dental contact with the lower—voltage circuit, or with persons
`or objects on the crossing Without first becoming grounded
`by contact with the guard wire. See also: ground.
`(T&D/PE) [10]
`GUI See: graphical user interface.
`guidance (missile) The process of conn‘olling the flight path
`through space through the agency of a mechanism within the
`missile. See also: guided missile.
`(EEC/PE) [119]
`guide (1) (high-voltage switchgear) An attachment used to se-
`‘ cure proper alignment when operating a fuse or switch.
`(SWG/PE) C37.40-l993
`(2) Document in which alternative approaches to good prac-
`tice are suggested but no clearvcut recommendations are
`made,
`(C/SE) 730.1-1995
`guide bearing (rotating machinery) A bearing arranged to
`limit the transverse movement of a vertical shaft. See also:
`bearing.
`(PE) [9]
`guided missile An unmanned device whose flight path through
`space may be controlled by a self—contained mechanism. See
`also: beam rider guidance; preset guidance; homing guid—
`ance; command guidance; guidance
`(EEC/PE)
`[119]
`guided mode Sec: bound mode.
`guided ray (fiber optics) In an optical waveguide, a ray that is
`completely confined to the core. Specifically, a ray at radial
`position 1' having direction such that
`sin 6(r) = [2120) * 112((1)]1/2
`
`whére 9(r) is the angle the ray makes with the waveguide
`axis, n (r) is the refractive index, and n (a) is the refractive
`index at the core radius. Guided rays correspond to bound (or
`guided) modes in the terminology of mode descriptors. Syn-
`onyms: bound ray; trapped ray. See also: bound mode; leaky
`ray.
`'
`(StleO) 812—1984w
`guided wave A propagating wave whose energy is concentrated
`Within or near boundaries between media having different
`electromagnetic properties.
`(AP/PROP) 211-1997
`
`
`
`
`
`
`
`
`7
`
`

`

`
`
`————-——-'_—_———T"
`
`pipeline processor
`830
`
`instruction
`operand
`instruction
`operand 77
`
`decode
`fetch
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`execution
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`
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`
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`
`INSTRUCT‘ON 1
`INSTRUCTION 2
`
`pixel
`
`instruction
`fetch
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`instruction
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`
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`
`instruction
`execution
`
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`
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`
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`TIME:
`.
`CURRENT TIME:
`
`pipeilnlng
`
`INSTRUC-HON a
`
`{NSTRUCTiON 4
`
`ANSTRUCTION 5
`
`
`
`pipeline processor A processor in which execution of instruc-
`tions takes place as a series of units, arranged so that several
`units can be simultaneously processing appropriate parts of
`several instructions.
`(C) 610.10-1994W
`pipelining Theiunction of forwarding in sequence some or all
`of the Beginning of Message (BOM) and Continuation of
`Message
`(COM) Derived .MAC Protocol Dara Units
`(DMPDUs) before receipt of the End of Message (EOM)
`DMPDU.
`(LM/C) 8802-6-1994
`(2)
`(A) Parallel processing in which instructions are executed
`in an assemblydine fashion: consecutive instructions are op-
`erated upon in sequence, but With several being initiated be-
`fore the first is complete. Synonym: pipeline processing, (B) A
`technique for operation inwhich each instruction is broken
`into multiple steps, which are performed by different portions
`of the computer. A typical instruction stream allows a differ»
`ent instruction to be at each step in the pipeline at any point
`in time, allowing multiple instructions to overlap execution.
`See the Corresponding figure. Note: In microprocessors, pipe<
`lining can make multiple cycle instructions appear to execute
`in a single clock cycle once the pipeline is full.
`_