0-9 A B C D E F G H I J K L M N O P Q R S T U V W XYZ

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safety ring:
Synonym for write ring.

sample:
To obtain the values of a function for regularly or irregularly spaced distinct values from its domain. Other meanings of this term may be used in particular fields; for example, in statistics.

sample-and-hold device:
A device that senses and stores the instantaneous value of an analog signal.

sampling:
In computer vision, converting a continuous image (like a photograph) into an image composed of discrete points.

sanitizing:
Erasing or overwriting all data on a magnetic or other data medium, so that the data cannot be recovered. Contrast with clear.

SAP:
service access point.

saturation:
The attribute of a color that expresses the degree of departure from the gray of the same luminance. A color that is highly saturated appears to be pure hue and free of gray, but if it is of low saturation it appears to have a great deal of gray mixed with it. All grays have zero saturation.

save:
A function or mode that enables the user to store a document on a data medium so as to make permanent the changes to that document.

save area:
In the context of temporary transfer of control from one program to another, an area of storage in which the registers and process data of the first program are stored so that the first program can be reactivated; this is applicable, for example, to multiprogramming, interrupt handling, and library calls.

scaffolding:
Programs and data designed to support software development and testing, but not intended to be included in the final product; for example: dummy routines or files, test case generators, software monitors, stubs.

scalable parallel processing:
Parallel processing that allows the addition of processors and users with minor increase in complexity.

scalar:
A quantity characterized by a single value. Contrast with vector.

scalar type:
A data type, each instance of which represents a scalar. Pascal simple types are either ordinal types or real types. Ada scalar types are either discrete types or real types. Synonymous with simple type.

scale:
(1) To alter the manner in which values are represented so as to bring them into a different range. For example, to change inches to centimeters. (2) In computer graphics, to enlarge or diminish all or part of a display image. Scaling does not have to be carried out with the same scale factor in all directions.

scale factor:
A number used as a multiplier in scaling; for example, a scale factor of 0.001 would be suitable to scale the values 856, 432, -95, and -182 to lie in the range -1 to +1, inclusive. Synonymous with scaling factor.

scaling factor:
Synonym for scale factor.

scan:
(1) To systematically examine data. (2) To use a scanner. (3) In computer vision, to examine an object or synthesize an image according to a predetermined sequence. Graphic images may be generated by a raster scan system. Examples:
  1. a fax system scanning a subject image left to right and top to bottom, as when reading;
  2. radar scanning from the image center outward at various angles corresponding to compass directions;
  3. generation of a television picture, line by line.

scan line:
A typically horizontal alignment of pixels that are scanned sequentially. Synonymous with scanning line.

scanner:
(1) A device that examines text, images, or patterns, and generates signals corresponding them. (2) In computer vision, a vision sensor that scans its environment in a systematic pattern; for example: a device that optically scans printed or written data and generates their digital representations.

scanning line:
Synonym for scan line.

scavenge:
To search, without authorization, through residual data to acquire sensitive information.

scene:
(1) In a script-based knowledge representation, a familiar sequence of stereotyped actions or events bound to similar sequences by causal relationships; for example: in a "restaurant" script, one may find the following scenes: entering, ordering, eating, paying, and leaving. Synonymous with episode. (2) A real-life setup of objects.

scene analysis:
The process of seeking information about a scene from data derived from an image.

scene view:
A virtual display viewed on a large screen or through a terminal window rather than with immersive devices.

schedule:
To allocate resources to jobs, tasks, or other units of work and place control data into a queue for dispatching.

scheduled maintenance:
Preventive maintenance carried out in accordance with an established time schedule. The time schedule is established according to the elapsed time, or the operating time, or the number of uses.

scheduler:
That part of the operating system that schedules jobs, tasks or other units for dispatching.

scheduling:
The process of carrying out a schedule operation.

schema:
(1) In artificial intelligence, a formalism for representing information about a simple concept, an entity, or a class of objects by means of its possible uses. The schema shows ways of using a concept. It does not describe typical instances of that concept. (2) A complete description of the structure of a database pertaining to a specific level of consideration.

scientific visualization:
The use of computer graphics and image processing to present models or characteristics of processes or objects for supporting human understanding; for example: a display image created by combining magnetic resonance scans of a tumor; volumetric top and side views of a lake showing temperature data; a two-dimensional model of electrical waves in the heart. Synonymous with visualization (in computer graphics).

scissoring:
Synonym for clipping.

scope:
That portion of a program within which a declaration is valid. Synonymous with scope of a declaration.

scope of a declaration:
Synonym for scope.

scramble:
In data communication, to convert a digital signal into a pseudorandom digital signal having the same meaning and the same bit rate in order to facilitate transmission or storage. Scrambling avoids problems that would result from the transmission of long sequences of "1"s or "0"s. It may also be used to provide a degree of privacy.

scratch-pad memory:
A read/write storage device or register that may be used for the temporary storage of intermediate data or pointers.

screen:
In a display device, the surface on which display images may appear.

screened-host gateway:
Synonym for bastion host.

screen editor:
A text editor that displays text on a screen and allows text editing of arbitrary character strings using cursor positions, without regard to line numbers.

screened subnetwork:
A subnetwork that permits access from both untrusted external networks and from internal networks, but does not permit traffic to flow between the two.

screening router:
A router capable of discriminating network-based traffic on the value of the protocol fields in the packet.

screen saver:
Software used to prevent burned images.

script:
(1) In knowledge representation, an event-oriented knowledge representation that uses predetermined sequences of events to determine the results of interactions between known entities. The event is represented by means of scenes, settings, thematic roles, and props. (2) In hypermedia and multimedia, a specification of how hyperobjects are to be presented to a user and how input from the user is to be handled.

script software:
Synonym for scriptware.

scriptware:
Software designed for the creation of scripts. Synonymous with script software.

scroll bar:
A bar placed on any edge of a screen or a window, used to control scrolling or to indicate the position range of the data or display image currently displayed.

scrolling:
The movement of a display image vertically or horizontally, to view data not otherwise visible within the boundaries of a screen or window.

scrub frame:
The border within which the imaging device is scanned with no incident light applied to remove any residual image left after a snapshot and a frame grab operation.

SCSI:
small computer system interface.

SD disk:
Synonym for single-density disk.

SDD:
single-density disk.

SDRAM:
synchronous DRAM.

SD system:
Synonym for speaker-dependent system.

SDU:
service data unit.

search:
(1) The examination of one or more data elements of a set to find those elements that have a given property. (2) In text processing, a function or mode that enables a user to locate occurrences of such things as particular character strings, embedded commands, or characters with a specific attribute in text. Synonymous with find.

search and replace:
A function or mode that enables a user to locate occurrences of such things as particular character strings, embedded commands, or characters with a specific attribute in text and selectively replace them with new text entered as part of the command. This function or mode may be performed on part of, or throughout, the document. Synonymous with find and replace.

search cycle:
The sequence of events of a search that is repeated for each data element.

search engine:
A server that allows a user to find the name or address of a network resource based on some content criteria, such as keywords. Examples of search engines: Lycos, Opentext, WebCrawler, Yahoo, AltaVista.

search key:
In a record, a data item that represents one of the data values of the range allowed for a particular attribute of an entity.

search robot:
Synonym for knowledge robot.

search space:
In artificial intelligence, a network composed of nodes that represent problem states or subproblem states and links that represent the means of moving from one node to another.

search time:
The time required for the read/write head of a direct access storage device to locate a particular record on a track corresponding to a given address or key. Search time is part of the latency, immediately following the seek time, and is followed by transfer time. Synonymous with rotational delay. (Figure 1 - Access time).

search tree:
A tree-like graph that indicates the rules that apply during a search, the nodes explored, and the results obtained.

secondary cache:
Synonym for level-two cache.

secondary index:
An index for secondary keys.

secondary key:
A key that is not a primary key, but for which an index is maintained and that may identify more than one record.

secondary recipient:
Synonym for copy recipient.

secondary station:
In high-level data link control, the data station that executes data link control functions as instructed by the primary station and that interprets received commands and generates responses to be transmitted.

second-generation language (2GL):
A programming language that extends a first-generation language to include higher level language constructs such as macroinstructions.

secret key:
A key that is intended for use by a limited number of correspondents for encryption and decryption.

sector:
A predetermined part of a track or band that can be addressed.

sector alignment:
A technique for copy protection that determines whether a floppy disk is an unauthorized copy by checking whether sectors are positioned properly from track to track.

sector cluster:
The smallest unit of space on a hard disk or on a floppy disk allocated to a file by an operating system and consisting of one or more sectors.

secure access management service:
In electronic mail, a service that provides protection for resources of the message handling system against their unauthorized use.

Secure Socket Layer (SSL):
An Internet security protocol designed to enable secure electronic financial transactions on the World Wide Web and other Internet services.

security audit:
An independent review and examination of data processing system records and activities to test for adequacy of system controls, to ensure compliance with established security policy and operational procedures, to detect breaches in security, and to recommend any indicated changes in control, security policy, and procedures.

security category:
A nonhierarchical grouping of sensitive information used to control access to data more finely than with hierarchical security classification alone.

security classification:
The determination of which specific degree of protection against disclosure the information requires, together with a designation of that degree of protection; for example, "top secret", "secret", "confidential". Contrast with compartment.

security clearance:
Permission granted to an individual to access information at or below a particular security level. Synonymous with clearance.

security filter:
A trusted computer system that enforces a security policy on the data that pass through the system.

security level:
(1) Each of several degrees of protective measures attributed to activities or functional units. (2) The combination of a hierarchical security classification and a set of security categories that represents the sensitivity of an object or the security clearance of a subject.

security policy:
A plan or course of action adopted for providing computer security.

seek:
Selectively to position the access mechanism of a direct access storage device.

seek time:
The time required for the access arm of a direct access storage device to be positioned on the appropriate track. Seek time is part of the latency. (Figure 1 - Access time).

see-through head-mounted display:
A head-mounted display that permits the user to simultaneously see the real world and a virtual world. Synonymous with see-through HMD.

see-through HMD:
Synonym for see-through head-mounted display.

segment:
In programming, a portion of a program that may be executed without the entire program being resident in main storage.

segmentation:
A technique for storage allocation in which parts of a program are loaded from auxiliary storage into main storage when needed.

selecting:
In data communications, the process of requesting one or more data stations to receive data. While generally used on a multipoint connection, selecting can be used on a point-to-point connection. Contrast with polling.

selection:
In databases, an operation of relational algebra that forms a new relation which is a subset of the entity occurrences from a given relation; for example: in a relation of "books" containing the attributes "author" and "title", the formation of a list of the titles of the books written by a particular author.

selection signal:
In a switched network, the sequence of characters that represent all the information required to establish a call.

selection sort:
A sort in which the items in a set are examined to find an item that fits specified criteria; this item is appended to the sorted set and removed from further consideration, and the process is repeated until all items are in the sorted set.

selective dump:
A dump of designated storage location areas only.

selective wait statement:
A select statement that waits for a call from an entry-call statement before it executes its sequence of statements.

select statement:
A compound statement that allows a calling task or a called task to choose alternative courses of action or to wait.

self-adapting program:
A program that can change its performance characteristics in response to its environment.

self-contained database language:
A database language sufficient to write complete application programs using databases, and therefore not necessarily embedded in a host language.

self-learning:
Learning from an internal knowledge base, or from new input data, without introduction of explicit external knowledge.

self-organization:
In artificial neural networks, the capability of an unsupervised learning neural network to adjust its connection weights according to the features found in the input patterns.

self-organizing network:
An artificial neural networks, having a self-organization capability. A self-organizing network is often designed to emulate the ability of brain cells to organize themselves into a pattern.

self-relative address:
An address that must be added to the address of the instruction in which it appears to obtain the address of the storage location to be accessed.

semantic net:
Synonym for semantic network.

semantic network:
A form of knowledge representation in which objects or concepts appear as network nodes connected with arcs or links that indicate the relationships between various nodes. Synonymous with semantic net.

semantics:
The relationships of symbols or groups of symbols to their meanings, independent of the manner of their interpretation and use. Contrast with syntax, pragmatics.

semaphore:
A data structure for controlling, by means of a queue, access to the resources that are available to more than one task, but only to one at a time.

sending service user:
In OSI, a service user that acts as a data source during the data transfer phase of a connection or during a particular instance of connectionless-mode transmission.

sensitive information:
In security, information that, as determined by a competent authority, must be protected because its disclosure, modification, destruction, or loss will cause perceivable damage to someone or something.

sensitivity:
In security, a measure of importance assigned to information by the information owner to denote its need for protection.

sensor glove:
Synonym for glove input device.

sentence:
A linguistic construct in a conceptual schema language that expresses a proposition.

sentence control:
In text processing, a control used to process text one sentence at a time; for example, skip, delete, move, print.

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