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Pertaining to a data object that has no explicit data type declaration.

anonymous FTP:
A form of FTP when the server permits anonymous login.

anonymous remailer:
A functional unit that allows originators of messages to keep their identities concealed from the ultimate recipients.

The process of responding to a calling data station to complete the establishment of a connection between data stations.

A technique to correct aliasing by giving the appearance of smooth lines and edges in a display image on a display surface.

anticipatory buffering:
A technique by which data are retrieved and stored in a buffer before they are needed.

anticipatory paging:
The transfer of a page from external memory to real memory prior to the moment of need.

antiglare screen:
A screen designed to reduce spurious reflections and hence glare and visual fatigue. Synonymous with non-reflective screen, glare-free screen.

antistatic device:
A device designed to minimize the buildup of static electricity, which can disrupt computer equipment or cause data loss.

anti-virus program:
A program designed to detect viruses and possibly to suggest or take corrective action. Synonymous with vaccine program.

A physical or logical opening that permits selective access; for example: a mask of adjacent characters that causes retention of corresponding characters, the opening in an aperture card that combines microfilm with a punched card.

aperture card:
A processible card of standard dimensions into which microfilm frames can be inserted.

Synonym for application programming interface.

An interactive language characterized by a concise design for solving mathematical problems that require complex vector or matrix manipulations. The name APL is an abbreviation for A Programming Language.

In text processing, a function or mode that enables a user to add a new document or character string to the end of previously entered text.

A small application program performing a specific function that runs on a client computer and that is loaded from a server as needed. Applets may be used for animation or for checking entry of data.

(1) A particular kind of work that a user performs on a computer; for example, a payroll application, an airline reservation system. (2) Abridged term for application software. (3) Loosely, synonymous with software package.

application association:
In OSI, a cooperative relationship between two application entities for the purpose of communication of information and coordination of their joint operation. An application association is supported by the exchange of application protocol control information using the presentation service.

application generator:
In OSI, a source code generator that produces programs to solve one or more problems in a particular application area.

application layer:
The layer that provides means for the application processes to access the OSI environment. This layer provides a means for the application processes to exchange information and it contains the application-oriented protocols by which these processes communicate. (Figure 47 - The Open Systems Interconnection Reference Model).

application-oriented language:
Synonym for problem-oriented language.

application program:
Synonym for application software.

application programming interface (API):
A set of subprograms that application programs may use to request and carry out lower-level services performed by an operating system.

application service:
A capability provided to an application.

application service element (ASE):
In OSI, that part of an entity of the application layer that provides a specific capability within the OSI environment, using underlying services when appropriate.

application software:
Software or a program that is specific to the solution of a category of application problems. For example, a spreadsheet program. Synonymous with application program.

A distributed-system-based service that locates files available by anonymous FTP on the Internet. Archie servers may provide access via telnet, electronic mail, or a special Archie client.

archival database:
An historical copy of a database saved at a significant point in time for use in recovery or restoration of the database.

To store backup files and any associated journals, usually for a given period of time.

archive file:
A file set aside for later research or verification, for security, or for any other purpose.

The storage of data to archive files.

(1) Two or more contiguous storage locations. (2) In the CODASYL model, a named subdivision of a database to which records can be assigned, irrespective of their set membership. Synonymous with file. (3) A named collection of records that may contain occurrences of one or more record types.

area analysis:
The process of examining the areas of a scene defined by specified characteristics.

area array sensor:
A vision sensor consisting of rows and columns of light-sensitive elements. Synonymous with matrix array sensor.

An independent variable or a value; for example, a search key, or a number that identifies the location of a data item in a table.

arithmetic check:
Synonym for mathematical check.

arithmetic and logic unit (ALU):
In a processor, the part that performs arithmetic operations and logic operations.

arithmetic operation:
An operation that follows the rules of arithmetic.

arithmetic overflow:
A condition that arises when the results of an arithmetic operation exceed the capacity of the number representation system used in a digital computer.

arithmetic register:
A register that holds the operands or the results of arithmetic operations or logic operations.

arithmetic shift:
A shift applied to the representation of a number in a fixed-radix notation while preserving the sign of the number. In some cases, fill characters are introduced in the vacated positions. An arithmetic shift is usually equivalent to multiplying the number by a positive or a negative integral power of the radix, except for the effect of any rounding. Contrast with logical shift.

An arrangement of elements of the same type in which these elements or appropriate groups of elements may be referenced randomly and independently of the others.

array processor:
A processor capable of applying simultaneously the same processing to corresponding elements of data arrays. In a special case where the array processor works on single elements, such elements are called " scalars". Synonymous with vector processor.

array slice:
A portion of an array that consists of contiguous cells along any dimension. In Ada, an array slice is also a basic operation. Synonymous with slice.

array type:
A composite type whose components are the same data type. Array types may be organized and referenced as if the components were arranged in columns, rows, etc.

Synonym for posting.

artificial feedback device:
In virtual reality, a simulation device used to stimulate some form of reality in response to a situation. Examples are a pneumatic gauntlet, an air-driven motion platform, a tactile glove, head-mounted displays.

artificial intelligence (AI):
(1) A branch of computer science devoted to developing data processing systems that performs functions normally associated with human intelligence, such as reasoning, learning, and self-improvement. (2) The capability of a device to perform functions that are normally associated with human intelligence such as reasoning, learning, and self-improvement.

artificial language:
A language whose rules are explicitly established by design as distinct from evolving in nature.

artificial life (A-life):
Software that in turn grows other software through the process of Darwinian natural selection; for example, genetic software engineering that can be used to evolve algorithms.

artificial neural network (ANN):
A network of primitive processing elements connected by weighted links with adjustable weights, in which each element produces a value by applying a nonlinear function to that element's input values, and transmits the result to other elements or presents that result as an output value. Whereas some artificial neural networks are intended to simulate the functioning of neurons in the nervous system, most artificial neural networks are used in artificial intelligence as realizations of the connectionist model. Examples of nonlinear functions are a threshold function, a sigmoid function, and a polynomial function. Synonymous with neural net, neural network.

artificial neuron:
A primitive processing element in a artificial neural network, with several inputs and one output, the output value of which is a nonlinear function of a linear combination of the input values with adjustable weighting coefficients. Artificial neurons are modeled according to the functioning of neurons in the nervous system and are interconnected in order to exchange messages. Each artificial neuron is a node of the artificial neural network, that cooperates and communicates with other neurons. A artificial neural network can also have input nodes which are not artificial neurons.

artificial-reality engine:
A computer system with software for generating virtual objects and virtual worlds, and for enabling user interaction. Synonymous with reality engine.

artificial speech:
Speech generated by a non-human entity. Synonymous with synthetic speech.

artificial vision:
Synonym for computer vision.

ART network:
Synonym for adaptive resonance theory network.

The part of a character, for example, the vertical strokes of lowercase letters such as b, d, h, and k, that extends to the top of the character box and above the top edge of other lowercase letters such as a, c, or e. Contrast with descender.

A standard code using a set of 7-bit coded characters that is used for information interchange among data processing systems, data communication systems, and associated equipment. The ASCII set consists of control characters and graphic characters. For ASCII using 8-bit bytes, the 8th but may be used for parity or for extending the character set. ASCII is the abbreviation for American Standard Code for Information Interchange.

application service element.

amplitude shift keying.

asymmetric multiprocessing.

aspect ratio:
The ratio of the breadth to the height of an image. Example: An aspect ratio of 4:3 means the horizontal dimension of the image frame is 4/3 the vertical dimension.

automatic speech recognition.

To translate from an assembly language into an object language.

An operating technique in which there are no stops between the assembling, linking, loading, and execution of a program.

assembled origin:
The address of the initial storage location assigned to all or part of a program by an assembler, a compiler, or a linkage editor.

A translator that can assemble.

assembler directive:
A language construct for controlling the assembly of a program.

assembly code:
Code expressed in a form that can be recognized and processed by an assembler.

assembly duration:
The amount of time needed to assemble a program.

assembly language:
A machine-oriented language that provides symbolic naming of operations and locations and other features such as macroinstructions. (Figure 2 - Hierarchy of language).

assembly phase:
The logical subdivision of a run that includes the execution of an assembler.

assembly program:
A program represented in an assembly language.

assembly time:
(1) Any instant at which assembly takes place. (2) Deprecated synonym for assembly duration.

A language construct specifying a particular status that must exist or a particular condition that must be satisfied at a particular point of a program when it will be executed.

assigned access name:
In an information resource dictionary, a name, assigned by a user or by the information resource dictionary system, that provides unique access to an entity.

assigned descriptive name:
In an information resource dictionary, a name for an entity that is more descriptive than its assigned access name.

Synonym for assignment statement.

assignment by name:
Synonym for named parameter association.

assignment statement:
A simple statement that replaces the current data value of a variable with a new data value specified by an expression. Synonymous with assignment.

association control service element (ACSE):
In OSI, an application service element that provides a consistent means for establishing and terminating all application associations.

associative learning:
Synonym for learning by analogy.

associative memory:
Synonym for associative storage.

associative storage:
A storage device able to recall a complete pattern or associated data based on matching a partial input pattern. The recalled pattern may be directly the desired output or a way to obtain the address of the searched information. An example application is a look-up table where the entries are all tested in parallel and a single match returns the address to the desired data. Synonymous with content-addressable memory, associative memory.

assumed-size aggregate:
An aggregate formal parameter that takes some or all of its subscript ranges from a corresponding actual parameter.

asymmetric cryptography:
Cryptography in which different keys are used for encryption and decryption. Public key encryption is a special case.

asymmetric multiprocessing (ASMP):
Multiprocessing in which parts of the operating system or one or more application programs must be assigned to specific processors. Contrast symmetric multiprocessing.

Pertaining to two or more processes that proceed independently of each other and independently of the occurrence of specific events.

asynchronous neural network:
A artificial neural network in which the artificial neurons are not updated simultaneously but, for example, at random or in some organized sequence.

asynchronous operation:
(1) An operation that occurs without a regular or predictable time relationship to a specified event; for example, the calling of an error diagnostic routine that may receive control at any time during the execution of a different program. (2) A sequence of operations that are executed out of time coincidence with any event. Contrast with synchronous operation.

asynchronous time-division multiplexing:
An asynchronous transmission mode that makes use of time division multiplexing.

asynchronous transmission:
Data transmission in which the start of each character or block of characters is arbitrary but, once started, signal elements are transmitted at a predetermined fixed rate.

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