Dedicated to my family. I am grateful to their patience, support and encouragement during the past years. Thanks to my wife, without whom I would not be able to achieve where I am right now. For so many times when I felt too desperate to carry on, she was always there by my side. And my one-year-old son. He, like an angel, came into our lives in the final year of my Ph.D session. He has brought us awkwardness, tiredness and surprises, but upon all these, hope and the greatest joy. He is my motivation to be a better man, a better dad, and to keep going.