Chairperson of the Committee

I would like to express my gratitude to all those who helped me to complete this thesis. I am deeply indebted to my supervisor Prof. Dr. Michael W Sobolewski whose help, stimulating suggestions and encouragement helped me during the time of research for this thesis. I would like to give my sincere thanks to Dr. Hector Hernandez and Dr Yu Zhuang for serving on my Thesis committee, for detailed reviews and for their invaluable guidance. I would also like to thank all my lab mates at the SORCER laboratory for providing a wonderful ambiance which made me feel at home and thus increased my productivity. I am also thankful to the Computer Science department for providing hardware and infrastructure for completing my research. I dedicate this thesis to my parents and brother for their encouragement, love, support and enthusiasm they have shown all my life. It is because of them that I am able to see this high point of my life. ii TABLE OF CONTENTS ACKNOWLEDGEMENT.................................................................................................. i