I would like to thank Dr. David Ebert first, for his patient guidance, constructive suggestions and evaluations in this project. I would also like to show my appreciation to Linglan Zhang, Naiwen Liao, Shuang Li, Xiaocheng Luan, Zhaozhou Zhang, Zhiguang Han and other friends for their help and encouragement. Finally, to my family, I thank them for their patience, support and their trust in me. Thank you all.