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LLC protocol:
logical link control protocol.

LLC sublayer:
logical link control sublayer.

LLC type 1:
logical link control type 1.

LLC type 2:
logical link control type 2.

LLC type 3:
logical link control type 3.

load:
(1) To transfer data into a storage device or a working register. (2) To put data into a database.

load-and-go:
An operating technique in which there are no stops between the loading and the execution of a program.

loaded origin:
The address of the initial storage location of a program that has been loaded into main storage.

loader:
A program that copies other programs from external storage to internal storage or data from external storage to internal storage or from internal storage to registers.

load map:
A computer-generated list that identifies the storage location or sizes of all or selected parts of programs or data residing in memory.

load module:
All or part of a program that is suitable for loading and for execution. A load module is usually the result of applying a linkage editor.

load point:
The beginning of the recordable area on a magnetic tape; some magnetic tape drives use a beginning-of-tape marker to indicate the position of the load point.

lobe:
A pair of channels between a data station and a lobe attaching unit, one channel for sending and one for receiving, as seen from the point of view of the attached data station.

lobe attaching unit:
A functional unit used to connect data stations to and disconnect data stations from a ring network without disrupting network operations.

lobe bypass:
The capability of a lobe attaching unit to disconnect a lobe and its attached data station from a ring network for replacement, relocation, or repair without disrupting network operations.

local:
Pertaining to a language construct that has a scope only within the declarative region in which it is declared.

local address administration:
Address administration in which all LAN individual addresses are unique within the same local area network.

local area network (LAN):
A computer network located on a user's premises within a limited geographical area. Communication within a local area network is not subject to external regulations; however, communication across the LAN boundary may be subject to some form of regulation. (Figure 39 - Example of a protocol structure for a LAN).

localization:
The principle applied to a set of modules which have the qualities of strong cohesion and loose coupling.

local procedure call:
The use of a message-processing facility that allows one process to communicate with another process on the same computer.

local transformation:
In computer graphics, image transformation in which the value of a pixel is modified based on the value of its neighboring pixels; for example: convolution, mathematical morphology. Synonymous with neighborhood processing.

location:
Any place in which data may be stored.

locator:
An input unit that provides data to represent coordinates of a position; for example: a graphics tablet or any pointing device.

lock:
(1) To prevent the operation of an input unit; for example, to prevent actuation of the keys of a keyboard. (2) A facility used to control access to a resource. (3) In an information resource dictionary system with entity-level security, a mechanism for restricting authorization for a set of operations to a particular entity of the information resource dictionary.

lock-and-key protection system:
A security system in which a key or password is matched with a specific access requirement.

lockout:
A technique for allocation of resources in which shared resources are protected by permitting access by only one device or process at a time and excluding others; for example, to prohibit reading of data while they are being updated.

lockout facility:
The facility that inhibits the entry of data when the calculator is in overflow or error condition.

LOD:
level of detail.

log:
(1) To chronologically record data about events. (2) To record automatically data concerning attempts by the system to query or to update a database. (3) Loosely, synonym for journal.

logger:
A functional unit that records events and physical conditions, usually with respect to time.

logical:
(1) Pertaining to content or meaning as opposed to location or actual implementation. (2) Pertaining to a view or description of data that does not depend on the characteristics of the computer system or of the physical storage. Contrast with physical.

logical access control:
The use of information-related mechanisms to provide access control; for example, the use of a password.

logical add:
Synonym for disjunction.

logical and:
Synonym for conjunction.

logical cohesion:
Cohesion in which the activities of a module are logically similar; for example, the processing of data from different input media in one module.

logical comparison:
The examination of two strings to determine if they are identical.

logical level:
A level of consideration at which all aspects deal with a database and its architecture, consistent with a conceptual schema and the corresponding information base, but abstract from its physical implementation. Contrast with physical level.

logical link control protocol (LLC protocol):
In a local area network, the protocol that governs the exchange of frames between data stations independent of how the transmission medium is shared. (Figure 39 - Example of a protocol structure for a LAN).

logical link control sublayer (LLC sublayer):
In a local area network, that part of the data link layer that supports medium-independent data-link functions. The LLC sublayer uses the services of the medium access control sublayer to provide services to the network layer. (Figure 39 - Example of a protocol structure for a LAN).

logical link control type 1 (LLC type 1):
An unacknowledged connectionless-mode transmission within the logical link control sublayer.

logical link control type 2 (LLC type 2):
A connection-mode transmission within the logical link control sublayer.

logical link control type 3 (LLC type 3):
An acknowledged connectionless-mode transmission within the logical link control sublayer.

logical multiply:
Deprecated synonym for conjunction.

logical object:
In text processing, an element of the specific logical structure of a document, which may have a meaning that is significant to the application or user; for example: a chapter, section, a paragraph.

logical operation:
Synonym for logic operation.

logical product:
Deprecated synonym for conjunction.

logical record:
A record whose data elements are related from a logical viewpoint, independent of their physical environment. Portions of one logical record may be located in different physical records, or several logical records or parts of logical records may be located in one physical record.

logical ring:
The simulation of a ring network by passing a token between data stations in a predefined sequence, even though the network's physical architecture may be different, such as a bus network. (Figure 40 - A logical ring on a physical bus).

logical schema:
(1) A part of a database schema that pertains to the logical level. (2) The part of the internal schema that pertains to the logical level and that, therefore, is a part of the database schema.

logical shift:
A simple shift without special operations such as the sign extension associated with the arithmetic shift. Synonymous with logic shift.

logical structure:
A logical relationship that exits among units of data.

logical sum:
Deprecated synonym for disjunction.

logical track:
A defined number of sectors in one or more tracks to be accessed in a specific sequence.

logical type:
A data type whose data objects can assume only logical values TRUE or FALSE and where the defined operations follow the rules of some symbolic logic. The truth values are frequently represented by 1 and 0 as in Boolean operations.

logic bomb:
Malicious logic that causes damage to a data processing system when triggered by some specific condition.

logic circuit:
A circuit that performs operations following the rules of symbolic logic; for example: a circuit whose input and output signals represent quantities that may assume values from a finite set of discrete values.

logic design:
A functional design that uses formal methods of description, such as symbolic logic.

logic diagram:
A graphic representation of a logic design.

logic function:
Deprecated synonym for switching function.

logic gate:
Synonym for gate.

logic instruction:
An instruction in which the operation part specifies a logic operation.

logic operation:
(1) An operation that follows the rules of some symbolic logic. Synonymous with logical operation. (2) An operation in which each character of the result depends only on the corresponding character of each operand. Synonymous with logical operation.

logic programming:
A method for structuring programs as sets of logical rules with predefined algorithms for the processing of input data to a program according to the rules of that program.

logic shift:
Synonym for logical shift.

logic symbol:
A symbol that represents a variable, an operator, a function, or a functional relationship.

logic variable:
Deprecated synonym for switching variable.

log in:
Synonym for logon.

login:
Synonym for logon.

logoff:
(1) The termination of a session. (2) To take the steps necessary to terminate a session or to orderly disconnect from a data processing system. Synonymous with logout, log off, log out.

log off:
Alternate spelling for logoff.

log on:
Alternate spelling for logon.

logon:
(1) The initiation of a session. (2) To enter identifying data and possible authentication data into a data processing system so as to be able to do work with the systems. Synonymous with login, log on, log in.

log out:
Synonym for logoff.

logout:
Synonym for logoff.

longitudinal magnetic recording:
A technique of magnetic recording in which magnetic polarities representing data are aligned along the length of the recording track.

longitudinal redundancy check character:
On a magnetic tape where each character is represented as a lateral row of bits, a character used for checking the parity of each track in the longitudinal direction. Such a character is usually the last character recorded in each block and is used in some magnetic recording systems to re-establish the initial recording status.

loop:
A sequence of statements or of instructions that may be executed iteratively while a certain condition prevails. In some implementations, no test is made to discover whether the condition prevails until the loop has been executed once.

loop assertion:
(1) A logical expression specifying one or more conditions that must be met each time a particular part of a loop is executed. (2) An assertion that has to be verified throughout the execution of a loop.

loop body:
The part of a loop that accomplishes the loop's primary purpose.

loop control:
A language construct that includes a test to determine whether an iteration of a loop is to be executed.

loop-control variable:
A data object used to determine whether to exit from a loop. Synonymous with loop parameter.

loophole:
Synonym for flaw.

loop initialization:
The parts of a loop that set the starting values of the loop.

loop invariant:
A condition that is invariant throughout a loop.

loop parameter:
Synonym for loop-control variable.

loop statement:
Synonym for iteration statement.

loss:
In computer security, a quantitative measure of harm or deprivation resulting from a compromise. (Figure 57 - Levels of security risks).

low-level processing:
In computer graphics, image processing using basic techniques to build or improve the representation of an image.

low-level vision:
In computer graphics, a process for extracting visual data from a scene using primitive modeling techniques such as representing the scene by edges or luminance contours.

LQ:
letter quality.

LSB:
least significant bit.

LSD:
least significant digit.

Lukasiewicz notation:
Synonym for prefix notation.

luminance:
The amount of light that is emitted by a pixel or by a particular area of a display surface. Luminance, hue, and saturation are three attributes of color. Intensity is a commonly-used term for luminance. Brightness is the term for the perception of the level of luminance.

lurk:
To read the messages in a computer conference without posting.

Lynx:
An early set of procedures built on the Internet Protocol and supporting file transfer that supported users in browsing text-oriented files on the World Wide Web.

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