Ping for their interesting courses and rigorous scientific attitude. In addition, I am also would like to show my appreciation to SPMS IT team and all administration staff for their support and help.I wish to acknowledge SPMS and NTU to provide me the research scholarship as my financial support.Special thanks would go to Meng Zhenyu, who puts a lot of effort during the preparation of my thesis. Your companion gives me the courage to move forward.Last but not least, my greatest thankfulness would go to my families for supporting me spiritually. Thank you for your love and continued encouragement.The help from all my beloved reminds me to endeavor for a higher peak. I will not let you down. Thanks again for all of you.