Thanks are due to many people. I particularly want to thank my major advisor, Prof. Jane Doe. Without her constant guidance and support, this thesis would not have obtained the high quality that it has. I also thank Profs. Don, Do, Duck, and I for serving on my committee. They are sure to recognize that the level of research in this paper is fully worthy of a Ph.D. Many thanks. This work was supported by the U.S. Central Intelligence Agency under a secret grant.