Technology — page 148 of 206

20,531 terms including subtopics (0 terms filed directly here)

Technology terms

quantum-noise-limited operation Operation wherein the minimum detectable signal is limited by quantum noise. Synonym quantum-limited operation.
quarter common intermediate format (QCIF) A video format defined in ITU-T Recommendation H.261 that is characterized by 176 luminance pixels on each of 144 lines, with half as many chrominance…
quarter quad One-quarter area of a four-sided quadrangle that depicts 7.5 minutes of latitude and 7.5 minutes of longitude on a side.
quartz clock A clock containing a quartz oscillator that determines the accuracy and precision of the clock.
quartz oscillator An oscillator in which a quartz crystal is used to stabilize the frequency. Note: The piezoelectric property of the quartz crystal results in a nearly…
quasi-analog signal A digital signal that has been converted to a form suitable for transmission over a specified analog channel.
quasi-analog transmission Transmission in which a special-purpose modulator is used to convert digital signals into an analog form suitable for transmission over an analog…
quasi-associated mode of signaling A limited case of the nonassociated mode of signaling in which the path taken by a message through the signaling network is predetermined and fixed at a…
quasi-lossless compression In video and multimedia applications, the bit-rate reduction of an image signal, by an algorithm that recognizes the high degree of correlation…
quasi-random signal (QRS) See QRS.
quaternary phase-shift keying Synonym quadrature phase-shift keying.
quaternary signal A digital signal having four significant conditions.
Queries per second (QPS) The number of queries that the enterprise search platform will process in one second.
Query A request for identification of a set of assets, expressed in terms of a set of criteria, which the identified item must satisfy.
query aggregator source An aggregator source (included in WS MDS) that polls a WSRF service for resource property information.
Query and result processing The application of algorithms to the original query or to the raw results returned by the search engine.
query call In adaptive high-frequency (HF) radio, an automatic-link-establishment (ALE) call that requests responses from stations having connectivity to the…
Query Refinement Some searchers may refine their search query if they deemed the results as being irrelevant.
query string A component of an HTTP request URL that contains a set of parameters and values that affect the handling of the request.
Query Syntax The semantic rules that must be observed when submitting queries to a search engine - for example, the use of parenthesis and Boolean operators.
Query term weight The ability to support different relevance weight for different terms in a query.
Query transformation The analysis and subsequent rewriting of a query, using linguistic transformations such as lemmatization and spell-checking.
query-based distribution group A distribution group that uses a Lightweight Directory Access Protocol (LDAP) query to derive its membership at the time the message is sent.
Query-By-Example A search where a user instructs an engine to find more documents that are similar to a particular document. Also called "find similar."
queue A system where if a realm is overloaded, subsequent players trying to log on will be queued up in a first come first serve basis and allowed to log on…
Queue Quick Reaction Launch Vehicle A store for a sequence of packets, or messages, which are waiting to be processed.
queue traffic A series of outgoing or incoming calls waiting for service. 2. In a store-and-forward switching center, the outgoing messages awaiting transmission at the…
queue URL A URL that uniquely identifies a queue.
Queue Viewer A tool in the Exchange Management Console that helps administrators monitor and manage messaging queues and the messages that are contained in those…
queuing The process of entering elements into or removing elements from a queue.
queuing delay In a switched network, the time between the completion of signaling by the call originator and the arrival of a ringing signal at the call receiver.
queuing theory The theoretical study of waiting lines, expressed in mathematical terms--including components such as number of waiting lines, number of servers, average…
quick link An association between a URI and keywords and phrases.
quiet installation Also known as unattended installation. An installation run by using the /q command-line option that runs without generating any user prompts.
quiet mode The mode of a command-line application where it does not display confirmation messages or any other user interface items that normally appear on screen.
quiet zone With respect to the rf spectrum, an area in which emissions are restricted for the purpose of minimizing possible impact on the operations of radio…
quieting In an FM receiver, the phenomenon that results in less noise when an unmodulated carrier is present than when there is no carrier present.
quincunx sampling 1. In a digital video system, a sampling structure where the luminance and color-difference samples are generated from pixels arranged on one of two…
quorum The number of Senators that must be present for the Senate to do business. The Constitution requires a majority of Senators (51) for a quorum.
quorum configuration Settings in a failover cluster that determine the point at which too many failures will stop the cluster from running.
quorum log The log where the quorum resource stores data. This data is maintained by the clustering software.
quorum resource For a server cluster, the quorum-capable resource selected to maintain the configuration data necessary for recovery of the cluster.
quorum server A cluster node that acts as a tie-breaker in a disaster tolerant architecture in case all of the nodes in a data center go down at the same time.
quota A way to specify limits to the amount of storage or number of users a Web site can use.
quota message An e-mail message that is automatically sent by Microsoft Exchange to the owners of a mailbox or a public folder when a size limit, which is called a…
quota template The specific set of quota limits to apply to a site or to all sites on a virtual server.
quotient When integer division is performed, the result consists of a quotient and a remainder.
QWIP Quantum Well Infrared Photodetector . 241
R 2 (1) Recovery and Reconstitution. (2) Reporting Responsibility.
R 2 P 2 Rapid-Retargeting/Precision Pointing (simulator).
R 3 Rotary Reciprocating Refrigerator.
R i Inherent Reliability.
R interface For a basic rate access in an ISDN environment, the interfacing specifications covering pre-ISDN standards (e.g., EIA-232C).
R m Mission Reliability (ILS term).
R&A Reliability and Availability.
R&D Research and Development.
R-T Real Time.
R/ASR Review as Required.
R/C Abbreviation for radio control, radio service.
R/W Read/Write.
R1 The first-generation offspring of a recombinant (genetically modified) organism. Not standard terminology. See: T0, T1, and T2.
R2 The Symmetrix term indicating the remote data copy that is the secondary copy. It is normally read-only by the nodes at the remote site.
R3 Rotary Reciprocating Refrigerator.
RA (Registrant Authority) A Registrant Authority works in conjunction with the Certificate Authority (CA) approving or rejecting requests for certificates of public keys.
RAA Risk Approval Authority.
RAAF Royal Australian Air Force.
RACE A distinguishable group of organisms of a particular species. Criteria for distinctness can be one or a combination of geographic, ecological…
race condition See race hazard.
race hazard A situation that arises between multiple threads sharing a resource. A race hazard arises when one thread's assumptions about the state of a resource are…
raceway Within a building, an enclosure, i.e., channel, used to contain and protect wires, cables, or bus bars.
rack A frame upon which one or more units of equipment are mounted. Note: DOD racks are always vertical.
racon See radar beacon.
RAD Radiation Absorbed Dose. The basic unit of an absorbed dose of ionizing radiation.
Rad Hard Radiation Hardened.
radar Acronym for RAdio Detection And Ranging; a radio device or system for locating an object by means of ultrahigh-frequency radio waves reflected from the…
Radar Beacon A receiver-transmitter combination which sends out a coded signal when triggered by the proper type of pulse, enabling determination of range and bearing…
radar beacon (racon) A transmitter-receiver associated with a fixed navigational mark which, when triggered by a radar, automatically returns a distinctive signal which can…
radar blind range The range that corresponds to the situation in which a radar transmitter is on and hence the receiver must be off, so that the radar transmitted signal…
radar blind speed The magnitude of the radial component of velocity of an object, i.e., a target, relative to a radar site, that cannot be measured by the radar unit.
Radar Cross Section The area of a fictitious, perfect reflector of electromagnetic waves (e.g., metal sphere) that would reflect the same amount of energy back to the radar…
Radar Cross Section (RCS) Area of an object as scanned by radar; measured in square meters.
radar intelligence (RADINT) Intelligence derived from data collected by radar. [JP 1-02]
radar mile The time required for a radar pulse to travel 1 mile (~1.6 km) to an object, i.e., to a target; reflect; and return to the receiver.
Radar Netting The linking of several radars to a single center to provide integrated target information.
radar resolution cell The volume of space that is occupied by a radar pulse and that is determined by the pulse duration and the horizontal and vertical beamwidths of the…
radar signature 1. The detailed waveform of a detected radar echo. Note: Radar signatures may be used to identify or distinguish among objects, i.e.
radar xxline-of-sight (LOS) equation An equation that expresses the radar horizon range (RHR), given by where RHRs is the radar horizon range in statute miles, h is the antenna height in…
RADC (1) Region Air Defense Commander. (2) OBSOLETE. Rome Air Development Center. (Now called Rome Laboratory.)
RADEC Radiation Detection Capability.
RADHAZ (1) Electromagnetic Radiation Hazard. (2) Hazards form electromagnetic radiation.
radian (rad.) A unit of plane angle measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.
radiance A measure of the intensity of the radiant energy flux emitted by a body in a given direction.
radiant emittance Radiant power emitted into a full sphere, i.e., 4 sr (steradians), by a unit area of a source, expressed in watts per square meter.
Radiant Energy Energy that transmits away from its source in all directions.
radiant exitance Synonym radiant emittance.
Radiant Exposure The total amount of thermal radiation energy received per unit area of exposed surface; it is usually expressed in calories per square centimeter. 242
radiant flux Deprecated synonym for radiant power.
radiant intensity Radiant power per unit solid angle, usually expressed in watts per steradian.
radiant power The rate of flow of electromagnetic energy, i.e., radiant energy. Note 1: Radiant power is usually expressed in watts, i.e., joules per second.
Radiation (RAY-dee-AY-shun) Energy released in the form of particle or electromagnetic waves.