Page 87 - Electrical Engineering Dictionary

bidirectional transmission distribution where s is a complex number. See Laplace
function(BTDF) theopticalscatteringfunc- transform.
tion for transmissive optics. The scattering
function vs. angle is normalized to signal at bilateral Z-transform a Z-transform of
zero degrees and with respect to solid angle the form
of detector, including obliquity factor.
+∞
X −n
bifilar winding a two-wire winding. It Zx = x[n]z .
is often utilized in stepper motors to permit a n=−∞
unipolar power supply to produce alternating
magnetic poles by energizing only half of the
bifilar winding at any one time. bilinear control systems a class of non-
linear control system models that are linear
bifurcation a term from Chaos Theory in state, output and control variables treated
referring to a sudden change in the qualitative separately but they contain the products of
behavior of the solutions. those variables. Such models arose naturally
in modeling the number of chemical pro-
bifurcation diagram a diagram where cesses where the controls are flow rates that
the sampled variable is plotted versus a pa- appear in the system equations as products
rameter. The sampling period is equal to the with state variables. The bilinear control sys-
source period. Similar to a Poincare map. tems may also be used to model population
dynamics perturbed by control actions which
big endian a storage scheme in which the enter growth equations as multipliers of state
most significant unit of data or an address is variables. Bilinear control systems can arise
stored at the lowest memory address. For alsoinconnectionwithadaptivecontrolnom-
example, in a 32-bit, or four-byte word in inally linear systems where uncertain pa-
memory, the most significant byte would be rameters regarded as additional state vari-
assigned address i, and the subsequent bytes ables leads to bilinear terms in model equa-
would be assigned the addresses: i +1, i +2, tions. Bilinear time-continuous control sys-
and i + 3. Thus, the least significant byte tems may be represented by the state equa-
would have the highest address of i + 3in tions having the form
a computer implementing the big endian ad-
dress assignment. “Big endian” computers m
X
include IBM 360, MIPS R2000, Motorola ˙ x = Ax + Bu + D i u i x
M68000, SPARC, and their successors. i=1
The little endian approach stores the least where x is the state vector, u the control vec-
significant unit at the lowest address. (The tor with components u i ,i = 1, 2,...,m,
terms big endian and little endian are taken A, B, D i are matrices of the appropriate di-
from Jonathan Swift’s satirical story, Gul- mensions. See also population dynamics.
liver’s Travels.
See also little endian.
bilinear interpolation interpolation of a
valuein2-Dspacefromfoursurroundingval-
BIL See basic lightning impulse level and
ues by fitting a hyperbolic paraboloid. The
basic impulse insulation level.
value at (x, y), denoted f (x, y) is interpo-
lated using f (x, y) = ax + by + cxy + d,
bilateral Laplace transform a Laplace
where a, b, c and d are obtained by substitut-
transform of the form
ing the four surrounding locations and values
Z into the same formula and solving the system
L{f }= +∞f(t)e −st dt,
of four simultaneous equations so formed.
−∞
c
2000 by CRC Press LLC