I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of. Philosophy.


                                     Sheng-San Li, Chairman
                                     Professor of
                                        Electrical Engineering



     I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.


                                      Fredrik A. Lindholm
                                      Professor of
                                        Electrical Engineering



     I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.


                                      Ulrich H. Kurzweg
                                      Professor of
                                        Engineering Sciences



     This dissertation was submitted to the Graduate Faculty of the
College of Engineering and to the Graduate Council, and was accepted as partial fulfillment of the requirements for the degree of Doctor of Philosophy.


August 1979                           Dean, College of Engineering


Dean, Graduate School