Page 100 - Electrical Engineering Dictionary

original (unextended) space X, where X is Boyle macromodel A SPICE computer
a space of functions with its corresponding model for an op amp. Developed by G. R.
extension X e . See also extended space and Boyle in 1974.
truncation.
Boys camera a rotating camera used to
bounded state an equilibrium state x e photograph lightning and establish the mul-
of a dynamic system is said to be bounded tiplicity of individual flashes in a lightning
if there exists a real number B = B(x 0 ,t 0 ), stroke.
where x 0 and t 0 represent the initial values of
the state and time, respectively, such that BPI bits per inch.
k x(t) k<B ∀t ≥ t 0
bps See bit per second.
See also stable state.
Bragg angle the required angle of inci-
bounded-input bounded-output (BIBO) dence for light into a Bragg cell to produce
a signal that has a certain value at a cer- a single diffraction order of maximum inten-
tain instant in time, and this value does not sity. The sine of the Bragg angle is approx-
equal infinity at any given instant of time. A imately the light wavelength divided by the
bounded output is the signal resulting from grating.
applying the bounded-input signal to a stable
system. See diagram below.
Bragg cell an acousto-optic cell designed
where only a single diffraction order is pro-
duced, generally by making the acoustic col-
umn thick along the light propagation direc-
tion.

Bounded-input bounded-output system. Bragg cell radiometer similar to an
acousto-optic spectrum analyzer in the Bragg
mode, but with generally much longer photo-
bounded-input bounded-output stability integration times such as via a long integra-
a linear dynamic system where a bounded tion time photo detector array.
input yields a bounded zero-state response.
More precisely, let be a bounded-input with Bragg diffraction the interaction of light
as the least upper bound (i.e., there is a fixed with a thick grating or acoustic wave, produc-
finite constant such that for every t or k), if ing a single diffraction order with maximum
there exists a scalar such that for every t (or intensity.
k), the output satisfies, then the system is said
to be bounded-input bounded-output stable. Bragg diffraction regime regime where
the acoustic beam width is sufficiently wide
bounded-input bounded-state (BIBS) sta- to produce only two diffracted beams, i.e.,
bility if for every bounded input ( See the undiffracted main beam (also called the
BIBO stability), and for arbitrary initial con- zero order or DC beam), and the principal
ditions, there exists a scalar such that the re- diffracted beam.
sultant state satisfies, then the system is said
to be bounded-input bounded-state stable. Bragg scattering the scattering of light
from a periodically varying refractive index
bounds fault an error that holds the map- variation in a thick medium, so-called by
per whet it detects the offset requested into analogy to the Bragg scattering of X-rays
an object exceeds the object’s size. from the atomic arrays in a crystal. For in-

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2000 by CRC Press LLC