Yong. Without their academic guidance and invaluable encouragement, the studies presented in this report would neither have started nor finished. They are not only professional mentors but also wonderful gentlemen. From them, I have not only learnt the methods and knowledge associated with the research, but also a lifelong treasure of the smart thinking and analytical skill. Then, many thanks go to my senior apprentice, Yan Lina. During the research period, she gave me many constructive suggestions and supports both on my research and course work. Meanwhile, I would like to thank all my teachers, friends and families, for their consistent support and encouragement. Many thanks also go to High Performance Computing Center at Nanyang Technological University. Parts of the computations were carried out on their hpc-rds platform. Last but not least, my hearted thanks go to my parents and my girlfriend Gu Yan. Their consistent love, encouragement and support are always the best impetus to my studies as well as to my life.