Page 230 - Electrical Engineering Dictionary

distributed generation small power distribution function See cumulative
plants at or near loads and scattered through- distribution function.
out the service area.
distribution management system (DMS)
distributed memory denotes a multipro- a system that helps manage the status of the
cessor system where main memory is dis- distribution network, crews and their work
tributed across the processors, as opposed flow, systemsafety, andabnormalconditions.
to being equally accessible to all. Each
processor has its own local main memory distribution switchboard a switchboard
(positioned physically “close”), and access used in the distribution system, typically
to other processors’ memory takes place within a building.
through passing of messages over a bus. The
term “loosely coupled” could also be used to distribution transformer a transformer
describe this type of multiprocessor architec- designed for use on a power distribution sys-
ture to contrast it from shared-memory archi- tem (typically 2.4 kV to 34.5 kV) to supply
tectures, which could be denoted as “strongly electrical power to a load at the proper uti-
coupled.” lization voltage.

distributed memory architecture a mul- disturbance a sudden change or a se-
tiprocessor architecture in which physical quence of changes in the components or the
memory is distributed among the processing formation of a power system. Also called
nodes, as opposed to being in a central loca- fault.
tion, equidistant from all processors.
disturbance decoupling of generalized 2-D
distributed refresh in a DRAM, carrying linear systems given the second general-
ized 2-D Fornasini–Marchesini model with
out refresh operations one at a time, at regular
disturbances
intervals. Requires that all rows be refreshed
in a time less that the time before which any
Ex i+1,j+1 = A 1 x i+1,j + A 2 x i,j+1
given row needs to be refreshed. See also
burst refresh. + B 1 u i+1,j + B 2 u i,j+1
+ H 1 z i+1,j + H 2 z i,j+1
distributed sample scrambling a modi-
y ij = Cx ij
fication of the reset scrambling technique in
which information regarding the state of the i, j ∈ Z + (the set of nonnegative integers),
scrambling sequence generator is embedded find a state-feedback u ij = Kx ij such that
into the encoded sequence in a distributed the output y ij is not affected by the distur-
n
fashion for purposes of synchronizing the de- bances for i, j ∈ Z + where x ij ∈ R ,u ij ∈
m
p
q
scrambling sequence generator. R ,y ij ∈ R ,z ij ∈ R are semistate vec-
tor, input vector, output vector, and distur-
distribution (1) the possibility to execute bance vector, respectively, and E, A k , B k ,
different parts of a system on different pro- H k (k = 1, 2,) are real matrices with E pos-
cessors. sibly singular or rectangular.
(2) that class of electric power system
work which is concerned with the distribu- dithering computer technique allowing
tion of electric power within a load area such the display and printing of gray-level images
as a residential or commercial area, or within on devices having a small number of avail-
an industrial installation. The distribution able colors (generally two, as in black-and-
circuit extends from the local substation and white CRTs and printers). The two main ap-
terminates at the customer’s meter. proaches are matrix dithering, where a matrix

c
2000 by CRC Press LLC