for the inspiration that I received from reading their publications. I wish to thank my officemate, Mr. C. P. Chiou as well for his continued interest and helpful discussions. To my parents, I am deeply grateful for their continuous encouragement and support in the past few years. Finally, a special word of thanks goes to my wife who has over the years provided me spiritual and logistic support. To her, I am truely indebted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.