Jennifer, for their assistances and friendship throughout the author's stay in NTU. Their efficiencies in handling technical and administrative stuffs are greatly treasured. The author gives thanks to the Lord for his parents, siblings and his wife for their constant prayers and support throughout his studies in NTU. Their silent contributions have helped the author to stay focus and complete this research. Last but not least, the author sincerely appreciate all his friends in NTU, Mr. Chen Hao, Ms. Chia and others (too many to mention); and also his church friends for their friendship, prayer and support. Their friendships throughout his stay in NTU are treasured every moment. May the Lord bless all of you and also those who read this thesis.