Page 174 - Electrical Engineering Dictionary

coordination instrument any means by or removing, permeable shims between the
which the coordinator unit influences behav- coil and copper jacket. The more shims in
ior or decisions of the subordinate (local) place the slower the magnetic field dissipates,
units; coordination instruments are often ex- hence the longer the time delay becomes.
pressed in terms of vectors of values assumed
by the coordination variables. In the case of copper loss electric loss due to the re-
price method, the coordination variables are sistance in conductors, windings, brush con-
the prices by which the interaction input and tacts or joints, in electric machinery or cir-
2
output variables are multiplied. cuits. Also referred to as I R, the losses are
manifested as heat.
coordination strategy mechanism (algo-
rithm) used to generate the values of the co- coprime 2-D polynomial matrices See
ordination instruments in the course of either coprimeness of 2-D polynomial matrices.
iterative or periodic coordination; in case of
iterative coordination, the convergence and coprime 2-D polynomials See coprime-
the speed of convergence of the coordination ness of 2-D polynomials.
strategy is of main concern; in case of peri-
coprimeness of 2-D polynomial matrices
odic coordination, other issues are important
a mathematical relationship of interest in
— these can be stability of the coordination
control systems.
process as well as quantitative aspects of the
A2-DpolynomialmatrixC(z 1 ,z 2 )(B(z 1 ,
controlled process behavior.
z 2 )) is called a right (left) divisor of A(z 1 ,z 2 )
if there exists a matrix B(z 1 ,z 2 )(C(z 1 ,z 2 ))
coordinator unit control (decision) agent
such that
in a hierarchical control structure, being in
charge of decisions (control instruments) in- A (z 1 ,z 2 ) = B (z 1 ,z 2 ) C (z 1 ,z 2 )
fluencing operation of the local decision
units; coordinator unit performs either itera- A 2-D polynomial matrix R(z 1 ,z 2 ) (L(z 1 ,
tive or periodic coordination of the local de- z 2 )) is called a common right (left) divisor of
cisions; coordinator unit is often regarded as A(z 1 ,z 2 ), andB(z 1 ,z 2 )ifthereexisttwo2-D
the supremal unit of the hierarchical control polynomial matrices A 1 (z 1 ,z 2 ), B 1 (z 1 ,z 2 ),
structure. Also called coordinating unit. (A 2 (z 1 ,z 2 ), B 2 (z 1 ,z 2 )) such that

copolarized the plane wave whose po- A (z 1 ,z 2 ) = A 1 (z 1 ,z 2 ) R (z 1 ,z 2 )
larization is the same as that of the reference
plane wave (e.g., radiated wave from an an- and
tenna) is said to be copolarized (otherwise it
B (z 1 ,z 2 ) = B 1 (z 1 ,z 2 ) R (z 1 ,z 2 )
is crosspolarized).
(A (z 1 ,z 2 ) = L (z 1 ,z 2 ) A 2 (z 1 ,z 2 )
copper jacket timer a magnetic time-off
and
timer that can be used in definite time DC
motor acceleration starters and controllers. B (z 1 ,z 2 ) = L (z 1 ,z 2 ) B 2 (z 1 ,z 2 ))
The copper jacket relay functions by slowing
the dissipation of the magnetic field when the A 2-D polynomial matrix P(z 1 ,z 2 ),
coil is turned off. After a certain amount (Q(z 1 ,z 2 )) is called greatest common right
of time the spring tension on the contac- (left) divisor of A(z 1 ,z 2 ) and B(z 1 ,z 2 ) if
tor overcomes the strength of the dissipat- P(z 1 ,z 2 ) (Q(z 1 ,z 2 )) is a greatest right
ing magnetic field — and causes the con- (left) divisor of A(z 1 ,z 2 ) and B(z 1 ,z 2 ) and
tacts to change state. Time delays with the any common right divisor of A(z 1 ,z 2 ) and
copper jacket timer are adjusted by adding, B(z 1 ,z 2 ) is a right divisor of P(z 1 ,z 2 ).

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2000 by CRC Press LLC