I would like to thank Brendan George, Donna Hamer and Gemma Lowle at Ashgate for effective co-operation. I would also like to express my gratitude to the two anonymous referees for their important comments. I completed this book at the Ritsumeikan Asia Pacific University, Japan. I am grateful to the university's free academic environment. I take great pleasure in expressing my gratitude to my wife, Gao Xiao, who has been wonderfully supportive of my efforts in writing this book in Beppu City, Japan. She also helped me to draw some of the figures in the book.