I would like to express my sincere gratitude to all those who have
guided and encouraged me throughout my Ph.D. studies, including my
family, friends, and mentors.

Special thanks go to my advisor, Dr. Stephen F. Siegel.  In the past
six years, Dr.\ Siegel kept being a great source of guidance in both
work and life.  He will always be an outstanding role model for me for
his endless pursuit of perfection in research.  Working with him is an
illuminating and valuable experience.

Finally, I would like to thank Dr.\ James Clause, Dr.\ Sunita
Chandrasekaran, Dr.\ Matthew B.\ Dwyer and Dr.\ William D.\ Gropp, for
serving as my committee members and giving me excellent feedback.