APPROVED:     

An undertaking such as a dissertation is not completed without the support of many people. My first debt of gratitude must go to my advisor, Dr. Barbara Chapman. She patiently provided the vision, encouragement and advise necessary for me to proceed through the doctorial program and complete my dissertation. Special thanks go to my committee, Dr. Jung-chang Huang, Dr. Christoph Eick, Dr. Rong Zheng and Dr. Min Ru for their helpful suggestions and time.

I am very grateful to Dr. Daewon Byun and his research group from the Geosciences Department who helped me understand their workflow application and provided valuable comments along my work. Also I appreciate the HPCTools group members: Dr. Babu Sundaram, Dr. Lei Huang, Chunhua Liao and Laksono Adhianto for the valuable discussions and friendships. It has been a great and enjoyable time to work with them. Special thanks to the faculty and staff of the Computer Science Department for their support and influence along on my career path. It has been a great experience to meet so many talented people during my study.

I want to acknowledge my wife, Fuhua Zhou, my son, Jonathan Yan, my parents and my parents-in-law for their love, support, encouragement and understanding in dealing with all the challenges I have faced. Nothing in a simple paragraph can express the love I have for you.