Page 175 - Electrical Engineering Dictionary
P. 175

2-D polynomial matrices A(z 1 ,z 2 ), B(z 1 ,  and
                              z 2 ) are called factor right (left) coprime if  h
                                                                          det B ˆ n 2  +ˆa n 2 −1 B ˆ n 2 −1  + ···
                              their greatest common right (left) divisor
                              is a unimodular matrix U(z 1 ,z 2 ) (nonzero                i
                                                                                  ˆ
                                                                              +ˆa 1 B +ˆa 0 I m 2  6= 0
                              detU(z 1 ,z 2 ) ∈ R).
                                2-D polynomial matrices A ∈ R p×m    or
                              [z 1 ,z 2 ], B ∈ R p×m  [z 1 ,z 2 ] (p+q ≥ m ≥ 1)     ¯    ¯ m 1 −1
                              are called zero right coprime if there exists a  det A ¯ m 1  + b m 1 −1 A  + ···

                              pair (z 1 ,z 2 ) which is a zero of all m × m      ¯ ¯  ¯     6= 0
                                                h i                           + b 1 A + b 0 I n 1
                              minors of the matrix  A  . The minor co-
                                                 B                   and
                              primeness of two 2-D polynomial matrices       h
                                                                                    ˆ
                              implies their factor coprimeness.          det A ˆ m 2  + b m 2 −1 A ˆ m 2 −1  + ···
                                                                                          i
                                                                                ˆ ˆ
                                                                                      ˆ
                              coprimeness of 2-D polynomials  a math-         + b 1 A + b 0 I n 2  6= 0
                              ematical relationship of interest in control
                              systems.                               where
                                A 2-D polynomial                              0   1   0 ...   0   
                                                                              0   0   1 ...   0   
                                         n 2          n 1                                         
                                         X            X                 ¯
                                                  i             j       A =    ... ... ... ...  ...  
                              p (z 1 ,z 2 ) =  a i (z 1 ) z =  a j (z 2 ) z                       
                                                  2             1            0    0   0 ...   1   
                                         i=0          j=0
                                                                             −¯a 0 −¯a 1 −¯a 2 ... −¯a n 1 −1
                              is called primitive if a i (z 1 ), i = 1, 2,...,n 2                 
                                                                               0   1   0 ...   0
                              and a j (z 2 ), j = 1, 2,...,n 1 are coprime
                                                                              0   0   1 ...   0   
                              (have not a common factor). Two primitive                           
                                                                        ˆ
                                                                        A =    ... ... ... ...  ...  
                              2-D polynomials are called factor coprime if                        
                                                                             0    0   0 ...   1   
                              their greatest common divisor is a constant.
                              The primitive 2-D polynomials                  −ˆa 0 −ˆa 1 −ˆa 2 ... −ˆa n 2 −1
                                                                                                  
                                                                               0   1   0 ...   0
                                            (z 2 ) ¯a (z 1 ,z 2 )
                               a (z 1 ,z 2 ) = a n 1                          0   0   1 ...   0   
                                                                                                  
                                                                        ¯
                                            (z 1 ) ˆa (z 1 ,z 2 )      B =    ... ... ... ...  ...  
                                       = a n 2
                                                                                                  
                                                                             0    0   0 ...   1   
                                                ¯
                                            (z 2 ) b (z 1 ,z 2 )
                               b (z 1 ,z 2 ) = b m 1
                                                                               ¯   ¯   ¯      ¯
                                                                             −b 0 −b 1 −b 2 ... −b m 1 −1
                                                ˆ
                                            (z 1 ) b (z 1 ,z 2 )
                                       = b m 2                                                     
                                                                               0   1   0 ...   0
                               ¯ a (z 1 ,z 2 ) = z n 1  +¯a n 1 −1 z n 1 −1  + ···   0
                                          1        1                               0   1 ...   0    
                                                                                                   
                                                                        ˆ
                                         +¯a 1 z 1 +¯a 0 (¯a i =¯a i (z 2 ))  B =   ... ... ... ,,,  ...  
                                                                                                   
                                                   n 2 −1                    0    0   0 ...   1
                                          n 2
                               ˆ a (z 1 ,z 2 ) = z  +ˆa n 2 −1 z  + ···                             
                                          2        2
                                                                               ˆ
                                                                                       ˆ
                                                                                   ˆ
                                                                                               ˆ
                                                                             −b 0 −b 1 −b 2 ... −b m 2 −1
                                         +ˆa 1 z 2 +ˆa 0  ˆ a i =ˆa i (z 1 )
                                              ¯
                               b (z 1 ,z 2 ) = z m 1  + b m 1 −1 z m 1 −1  + ···
                               ¯
                                          1         1
                                                                     coprocessor  a processor that is connected
                                           ¯     ¯    ¯   ¯
                                         + b 1 z 1 + b 0  b i = b i (z 2 )  to a main processor and operates concur-
                               b (z 1 ,z 2 ) = z m 2  + b m 2 −1 z m 2 −1  + ···  rently with the main processor, although un-
                                              ˆ
                               ˆ
                                          2         2
                                                                     der the control of the main processor. Copro-
                                           ˆ     ˆ    ˆ   ˆ
                                         + b 1 z 2 + b 0  b i = b i (z 1 )  cessors are usually special-purpose process-
                                                                     ing units, such as floating point, array, DSP,
                              are factor coprime if and only if      or graphics data processors.

                                   det B ¯ n 1  +¯a n 1 −1 B ¯ n 1 −1  + ···
                                                                     copy-back    in cache systems an opera-

                                            ¯
                                       +¯a 1 B +¯a 0 I m 1  6= 0     tion that is the same as write-back—a write
                              c 
2000 by CRC Press LLC
   170   171   172   173   174   175   176   177   178   179   180