Technology terms starting with D

1,369 terms

DIP switch A group of subminiature switches mounted in a package compatible with standard integrated-circuit sockets.
diplex operation The sharing of one common element, such as a single antenna or channel, for transmission or reception of two simultaneous, independent signals on two…
diplexer A three-port frequency-dependent device that may be used as a separator or a combiner of signals.
dipole antenna Usually a straight, center-fed, one-half wavelength antenna.
DIPS Dynamic Isotope Power System (which provides up to 10 kW of power).
dipulse coding The coding of "1's" and "0's" in a message in which one full cycle of a square wave, i.e.
DIR 1. Direction 2. On a buoy report, the ten-minute average wind direction measurements in degrees clockwise from true North.
Dirac delta function Synonym unit impulse.
direct access The ability of an electric power consumer to purchase electricity from a supplier of their choice without being physically inhibited by the owner of the…
Direct Access File System (DAFS) A file system based on virtual interface (VI) architecture, designed for narrow-sharing environments, that is, environments where the machines that are…
direct access restore (DAR) A process by which select data is restored from an NDMP tape backup device to the filer.
direct address In computing, an address that designates the storage location of an item of data to be treated as an operand.
Direct Air Support Center A subordinate operational component of a tactical air control system designed for control and direction of close air support and other tactical air…
direct bond An electrical connection using continuous metal-to-metal contact between the members being joined.
Direct Broadcast Satellite (DBS/DISH) A high-powered satellite that transmits or retransmits signals which are intended for direct reception by the public.
direct broadcast satellite radio See satellite digital audio radio service.
direct call A facility-handled call in which the network interprets the call request signal as an instruction to establish a connection based on previously designated…
direct connect 1. In computer systems, a permanent communications link that connects directly to a mainframe computer through a terminal controller, usually at binary…
Direct Cost Any cost that is specifically identified with a particular final cost objective.
direct coupling Synonym conductive coupling.
direct current signaling (DX signaling) In telephony, a method whereby the signaling circuit E & M leads use the same cable pair(s) as the voice circuit and no filter is required to separate the…
direct detection See detection.
direct dialing service A service feature that permits a user to place information concerning credit card calls, collect calls, and special billing calls into the public…
direct distance dialing (DDD) A network-provided service feature in which a call originator may, without operator assistance, call any other user outside the local calling area.
direct entry selection of natural word order when formulating and indexing a term consisting of two or more words (for example, "diazo microfilm" rather than…
Direct Hit A close approach of a tropical cyclone to a particular location. For locations on the left-hand side of a tropical cyclone's track (looking in the…
direct inward dialing (DID) A service feature that allows inward-directed calls to a PBX to reach a specific PBX extension without human intervention. Synonym network inward dialing.
Direct Labor Labor specifically identified with a particular final cost objective. Manufacturing direct labor includes fabrication, assembly, inspection and test for…
direct orbit For a satellite orbiting the Earth, an orbit in which the projection of the satellite on the equatorial plane revolves about the Earth in the same…
direct outward dialing (DOD) An automated PBX service feature that provides for outgoing calls to be dialed directly from the user terminal. Synonym network outward dialing.
direct postoffice A postoffice connected through a local area network (LAN), an asychronous connection, or an X.25 connection. [Exchange 5.5]
Direct Push A technology that ensures that a mobile device automatically retrieves new e-mail from the Microsoft Exchange server.
direct ray A ray of electromagnetic radiation that follows the path of least possible propagation time between transmitting and receiving antennas.
direct recording In facsimile systems, recording in which a visible record is produced, without subsequent processing, in response to received signals.
direct recursion Recursion that results from a method calling itself.
direct trust In Exchange Server 2007, authentication functionality for which the presence of the certificate in the Active Directory directory service or Active…
direct-buried cable A communication cable manufactured or produced for the purpose of burial in direct contact with the earth.
direct-sequence modulation In spread-spectrum systems, modulation in which a sequence of binary pulses is used directly to modulate a carrier, usually by phase-shift keying.
direct-sequence spread spectrum 1. A system (a) for generating spread-spectrum transmissions by phase-modulating a sine wave pseudorandomly with a continuous string of pseudonoise code…
direct-spread modulation Synonym direct-sequence modulation.
directed broadcast address An Internet Protocol address that specifies "all hosts" on a specified network.
Directed Energy (DE) 1. Energy in the form of atomic particles, pellets, or focused electromagnetic beams that can be sent long distances at, or nearly at, the speed of light.
Directed Energy Device A system using directed energy primarily for a purpose other than as a weapon. Directed energy devices may produce effects that could allow the device to…
Directed Energy Weapon (DEW) A system using directed energy primarily as a direct means to damage or destroy enemy equipment, facilities, and personnel.
directed net A radio net in which no station other than the net control station may communicate with any other station without first obtaining permission from the net…
directed network A network in which each arc has an associated direction of flow. Direction of flow can be determined by arc direction (e.g.
Directed search A narrow search within a specified area of the indexed content. Users may choose to search within "news" if they want the latest updates on today's game…
direction finding A procedure for obtaining bearings of radio frequency emitters by using a highly directional antenna and a display unit on an intercept receiver or…
direction of scanning In a facsimile transmitting apparatus, the scanning of the plane (developed in the case of a drum transmitter) of the message surface along lines running…
directional antenna An antenna in which the radiation pattern is not omnidirectional, i.e., a nonisotropic antenna.
directional coupler A transmission coupling device for separately sampling (through a known coupling loss) either the forward (incident) or the backward (reflected) wave in a…
directionalization The temporary conversion of a portion or all of a two-way trunk group to one-way trunks favoring traffic flowing away from a congested switch.
directive A "pod" directive. See perlpod.
directive gain Of an antenna, the ratio of (a) 4 times the radiance, i.e., power radiated per unit solid angle (watts per steradian), in a given direction to (b) the…
directives management application of records management principles and techniques to general instructions, bulletins, policies/procedures, or other official issuances
directivity pattern Synonym radiation pattern.
Directory A simulated file folder or container used to organize files and directories in a hierarchical or tree-like structure.
directory access protocol (DAP) A directory protocol that defines the exchange of requests and outcomes between user and system. [T1.667-1999]
directory assistance A feature used by servers to extend client authentication, name lookups, and LDAP operations to secondary directories.
Directory Assistance (DA) A service providing the requested telephone number for a given name and address.
Directory Assistance Call Completion (DACC) After the telephone number has been received, DACC is a service that permits a call to be completed to the requested number, typically at the calling…
directory assistance database A database created from the DA50.NTF template and used to configure directory assistance.
Directory Assistance document A document created in a directory assistance database that describes a secondary directory.
Directory catalog An optional directory database that can aggregate entries from multiple Domino Directories into a single database.
directory export The process of exporting user account information from the directory. [Exchange 5.5]
directory handle A name that represents a particular instance of opening a directory to read it, until you close it. See the opendir function.
directory harvest attack An attempt to collect valid e-mail addresses from a particular organization so that the e-mail addresses can be added to a spam database. [Exchange 2007]
directory hierarchy In the Administrator program, the hierarchical structure of objects in the directory. [Exchange 5.5]
directory import The process of importing user account information into the directory. [Exchange 5.5]
directory number A network (sub)address (from a telephone user perspective) such as the telephone number in the telecommunication network.
directory object A record such as a server, mailbox, or distribution list in the directory. Every object has properties that can be defined. [Exchange 5.5]
Directory partition A contiguous sub-tree of the directory that forms a unit of replication. A given replica is always a replica of some directory partition.
directory replication The process of updating the directories of all servers within and between sites. [Exchange 5.5]
directory replication bridgehead server An Exchange computer that acts as the endpoint of a directory replication connection between its site and a remote site, and requests directory updates…
directory server A server whose purpose is to provide directory services.
directory server (DS) A unit consisting of a DSA (directory system agent) and possibly other application processes (such as registration management) to provide the directory…
Directory Service Both the directory information source and the service that makes the information available and usable.
Directory Services Markup Language (DSML) An open, extensible, standards-based format for publishing directory service schemas and exchanging directory contents.
Directory Services Restore Mode A special safe mode boot option for Windows Server domain controllers that allows you to repair or restore the Active Directoryâ¢ service database.
directory synchronization The process of synchronizing directory information about Exchange users from Active Directory with the directory of another messaging system.
directory system agent (DSA) The software that provides the X.500 directory service for a portion of the directory information base.
directory user agent (DUA) The software that accesses the X.500 directory service on behalf of the directory user.
Directory-enabled application An application that reads, writes, or modifies data that is stored in a directory service.
DIRLAUTH Direct Liaison Authorized.
DIRNSA Director, National Security Agency.
DIS (1) Distributed Interactive Simulation. (2) Defense Investigative Service.
DISA Defense Information Systems Agency, Washington, DC. (Formerly known as Defense Communications Agency).
Disabled When applied to privilege: a privilege that is inactive, i.e., has its effective flag cleared [POSIX.6].
disabling tone A tone, transmitted over a communications path, used to control equipment. Note: An example of a disabling tone is a tone that places an echo suppressor…
Disaster An event that demands a crisis response beyond the scope of any single line agency or service (e.g.
disaster protection (Don't use this term?) Processes, tools, hardware, and software that provide protection in the event of an extreme occurrence that causes application…
Disaster Recovery The process of restoring access to applications and data after a disaster. Disaster recovery can be manual, meaning human intervention is required, or it…
Disaster Recovery (DR) An architecture is a prevention mechanism that scales up immediately and enable a rapid failover in case of a failure in users’ critical IT systems.
disaster recovery plan A written and approved course of action to take after a disaster strikes that details how an organization will restore critical business functions and…
Disaster Recovery Plan (DRP) A written plan for processing critical applications in the event of a major hardware or software failure or destruction of facilities.
disaster recovery services Services and products offered by companies that provide the hardware, software, processes, and people necessary to recover from a disaster.
disaster tolerant The characteristic of being able to recover quickly from a disaster. Components of disaster tolerance include redundant hardware, data replication…
disaster tolerant architecture A cluster architecture that protects against multiple points of failure or a single catastrophic failure that affects many components by locating parts of…
disc See diskette.
disciplined development Development of a system or part of a system where the documentation and evidence of testing against the documentation is to normal industry standards.