In a facsimile receiver, the dimension that (a) is perpendicular to a scanning line and (b) is the smallest recognizable detail of the image produced by the shortest signal capable of actuating the facsimile receiver under specified conditions. [From Weik '89]

1. A hidden software or hardware mechanism, usually created for testing and troubleshooting, that may be used to circumvent computer security. [2382-pt.8]
2. A hidden software or hardware mechanism that permits system protection mechanisms to be circumvented. It is activated in some non-apparent manner (e.g., special "random" key sequence at a terminal) [TCSEC].

An electromagnetic wave that enters a layer of material that is surrounded on both sides by a layer of material of a lesser refractive index such that, if the wave is traveling parallel or nearly parallel to the surfaces of the layers and hence the incident angles with the surfaces are greater than the critical angle, i.e., the angles are… (Read More →)

Synonym bound mode.

Synonym guided ray.

A wave that (a) propagates in a transmission medium, (b) has a velocity determined by the launching conditions and the physical properties of the medium, and (c) may be a longitudinal or transverse wave.
Note 1: For the purposes of this definition, free space may be considered a medium, although it is not a physical medium.
Note 2: A traveling… (Read More →)

Transport Resource Control Functional Entity

See network topology.

In a tree structure, a search in which it is possible to decide, at each step, which part of the tree may be rejected without a further search.

A hierarchical organization in which a given node is considered to be an ancestor of all the lower level nodes to which the given node is connected.
Note 1: The root node, i.e., the base node, is an ancestor of all the other nodes.
Note 2: In a tree structure there is one and only one path from any point… (Read More →)