Looking back there are so many people who must be thanked for their support during my studies. My parents must be thanked for their many years of support, through all of my studies. Also, my wife Alicia has provided years of encouragement, and this thesis would not have been possible without her patience and understanding.
Among the others to thank, my advisor, Professor W.H.ElMaraghy for his timely advice, Dan Corrin for his help in avoiding computational peril, and my academic colleagues for their discussions, and suggestions.