Page 258 - Electrical Engineering Dictionary

−t
For example, the signal f(t) = e ,t ≥ 0is in the controller. Originally designed by
an energy signal. The signal f(t) = 1isnot Maxtor.
an energy signal. The definition has practi-
cal significance if the signal f is a voltage, enhancement improvement of signal
or current, applied to an electric circuit, as quality without reference to a model of sig-
shown in the figure. The energy dissipated nal degradation. See restoration, image
by the circuit is given by enhancement.

Z inf ty
1 2
v(t) dt . enhancement mode an FET that is off
R
when zero volts bias is applied from gate to
−∞
A discrete time signal is an energy signal source.
if
ENI See equivalent noise current.
∞
X 2
f(k) < ∞ .
ENR See excess noise ratio.
k=−∞
enriched uranium uranium which con-
energy-density spectrum for a continu-
2
ous time signal x(t) the function |X(w)| , tains 1.5% to 5% of fissile U-235 and is thus
suitable for use in power reactors.
where X(w) is the Fourier Transform of
x. The function |X(w)| 2 is referred
to as an energy-density spectrum because enrichment the process of increasing the
2
1|X(w 0 )| is proportional to the energy in ratio of one isotope of a chemical element,
the signal x in a bandwidth 1 around the e.g. fissile uranium, to another, less desirable
frequency w 0 . Analogously, a discrete time isotope, e.g. non-fissile uranium.
signal x[n] has an energy-density spectrum
2
|X()| . ensemble processor a parallel processor
consisting of a number of processing ele-
enhanced backscattering peak of the an- ments, memory modules, and input/output
gular distribution of scattered intensity in the devices under a single control unit. It has
retroreflection direction, due to multiple scat- no interconnection network to provide inter-
tering of light in dense volumes or very rough processor or processor-memory communica-
boundaries. tions.
enhanced graphics adaptor (EGA) a
entity a software process that implements
video adapter proposed by IBM in 1984. It is
a part of a protocol in a computer communi-
capable of emulating CGA and MDA. It can
cation network.
reach 43 lines with 80 columns. In graphic
mode, it can reach 640 × 350 pixels (wide per
entity relationship diagram a diagram
high) with 16 colors selected from a pallet of
that describes the important entities in a sys-
64.
tem and the ways in which they are interre-
enhanced small device interface See lated.
enhanced small disk interface.
entropy information theoretic quantity
enhanced small disk interface (ESDI) representing the amount of uncertainty in
massstoragedeviceinterfacesimilartoMFM guessing the value of a random variable. For
and RLL except that the clock recovery cir- a discrete random variable X, with probabil-
cuits are in the peripheral device rather than ity mass function p(x) defined on the support

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