Page 184 - Electrical Engineering Dictionary

cross luma See cross luminance. cross-compiler a computer program that
translates a source code into machine or as-
cross luminance NTSC video artifact sembly code for a target machine different
that causes chrominance information present from the one on which the cross-compiler
in the decoded luma signal (chrominance runs.
crossed into luminance). Cross luminance
has the appearance similar to a zipper caused cross-correlation a measure of the cor-
by the color subcarrier. Television receivers relation or similarity of two signals. For
thatusealinecombfiltertoseparatelumaand random processes x(t) and y(t), the cross-
chroma signals have cross-luminance com- correlation is given by: R xy (t 1 ,t 2 ) =
ponents appearing on sharp horizontal edges. Ex(t 1 )y(t 2 ). See wide sense stationary
Television receivers that use a band-pass fil- uncorrelated scattering channel.
ter for luma–chroma separation have cross-
chrominancecomponentsappearingonsharp cross-correlation function a function de-
scribing the degree of similarity between two
vertical edges.
signals, as a function of time-shift between
the signals. See also correlation function.
cross modulation an undesired intermod-
ulation of an electromagnetic carrier wave by
cross-field theory a conceptual way to
another electromagnetic carrier wave that is
envision the operation of a single-phase in-
either physically adjacent to it or near it in
duction motor. The rotor current is assumed
terms of its radio frequency.
to produce a magnetic field electrically and
spatially orthogonal to the field produced by
cross polar discrimination the ratio the main stator winding, thus contributing to
of co-polar to cross-polar received field a rotating magnetic field.
strengths in a depolarizing medium. Usually
expressed in decibels. cross-polarization the field component
orthogonal to the desired radiated field com-
crosspolarisolation theratio between the ponent (co-polar component).
field received by an antenna with one polar-
ization from co-polar and cross-polar trans- cross-quad the simplest form of the com-
missions. This expresses the receiver’s abil- mon centroid concept, in which two matched
ity to detect one signal when dual-polarized transistors are formed by connecting diago-
signals are transmitted through a depolariz- nally opposite devices in a two-by-two array
ing medium. of transistors.

crossarm a transverse, generally insu-
cross power spectrum for two jointly
lated member mounted horizontally on a util-
wide sense stationary random processes the
ity pole. It carries insulators and allows wide
Fourier transform of their cross-correlation.
spacing of overhead conductors.
cross spectra computation of the energy crossarm brace a brace, often insulated,
in the frequency distribution of two different which keeps a crossarm from rotating on its
electrical signals. attachment bolts.

cross-assembler a computer program that crossbar switch a structure that allows
translates assembly language into machine N units to communicate directly with each
code for a target machine different from the other, point to point. Which pairs are con-
one on which the cross-assembler runs. nected depends on how the switch is config-

c
2000 by CRC Press LLC