certify that i have road this stuiy and that in my opinion it
conforms to acceptable starP.ards of scholarly presentation and is fully
adequa.tc, Wi scope and quality, as a dissertation for the degree of
Doctor : of Philosophy.



 Arthur I Westbereg, Chai an
 Associate Professor of Chemical
 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.



 en I'. DiYector
 Associate Professor of Electrical
 Engineering

 I certify that I have road this study and that in my opinion it
ca'for,-i: to acceptable staiudards of scholarly presentation and is fully
adequatL, in scope and quality. as a dissertation for the degree of
Doctor. of Philosophy.



 Frank D. Vickers
 Associate Professor of Computer and
 Information Sciences


This dissertation was submitted to the Graduate Faculty of the College
of Engineering and to the Graduate Counci!, and was accepted as partial
fulfili~l nt of the requirements for the degree of Doctor of Philosophy.

June, 1974



 Dean, Coll yge of Engineering


Dean, Graduate School