Page 185 - Electrical Engineering Dictionary

ured at that point in time. Crossbars are usu- crowbar a triggered, shunt device that di-
ally implemented for small (8 or less) num- verts the stored energy of the beam power
bers of nodes, but not always. supply.

CRR See cochannel reuse ratio.
crossed field devices (CFD) radial or lin-
ear forward traveling wave amplifier or back-
CRT See cathode ray tube.
ward wave oscillator where radial or trans-
verse DC accelerating electric fields are per-
crystal filter reference amplifier a
pendicular to axial or longitudinal DC mag-
generic phrase that refers to a cascade of am-
netic fields, respectively.
plifying stages coupled together with the aid
of crystal filter networks. Various topolo-
crossing number the even number ob-
gies are available for the connection of these
tained by adding the number of changes in
crystals (lattice, bridged, hybrid, and ladder).
binary value on going once around a particu-
The outstanding feature of such an arrange-
lar pixel location; crossing number is useful
ment is that the amplitude versus frequency
for finding skeletons of shapes and for help-
and phase versus frequency characteristics
ing with their analysis: it is a measure of the
are essentially determined by the crystal ar-
number of ‘spokes’ of an object emanating
rangements.
from a specified location.
crystal oscillator an electronic circuit
crossmodulation modulation of a desired used for generating a sinusoidal waveform
carrier by an undesired interfering signal due whose frequency is determined by a piezo-
to interaction of the two signals in one or electric crystal device.
more nonlinear elements.
crystalline phase in crystalline materials
crossover frequency the frequency where the constituent atoms are arranged in regu-
the magnitude of the open-loop gain is 1. lar geometric ways; for instance in the cubic
phase the atoms occupy the corners of a cube
(edge dimensions ≈ 2–15 ˚ A for typical ox-
crossover point a crossover point of a
ides).
fuzzy set A is the point in the universe of
discourse whose membership in A is 0.5.
CSI See current-source inverter.
crosspoint a point at which two overlap CSIM Seecapacitor-startinductionmotor.
neighboring fuzzy sets have the same mem-
bership grade.
CSMA See carrier-sense multiple access.
crosspoint level the membership grade of
CSMA-CA CSMA with collision avoid-
a fuzzy set at a crosspoint.
ance, a modification of the CSMA multiple
access protocol to make it suitable for use in a
crosstalk (1) undesired coupling (resis-
radio environment. Prior to the transmission
tive, capacitive, or inductive) from one sig-
of a message, a source and destination node
nal wire or transmission line to a colocated
undertake an exchange of short messages to
signal wire or transmission line.
ensure that the destination node is idle and
(2) capacitative interference between two capable of receiving a transmission from the
parallel transmission lines, in which a signal source node. See also carrier-sense multiple
on one line affects a signal on the other line. access.

c
2000 by CRC Press LLC