Completing my doctoral studies by writing this thesis would not have been possible without the support of my supervisor, many colleagues, friends and my family. Whatever I write cannot truly represent the depth of my gratitude, and the following lines are merely an attempt to capture at least a fragment of my thankfulness. I wish to express my special gratitude to my supervisor, Prof. Dr. Dr. Wolfgang. A. Halang, for giving me the opportunity to perform research in this interesting area, and to have been able to pursue my studies under his supervision. This has already been my dream in China for many years. I am even more impressed by his detailed help in my research proposition and my paper writing, especially for his encouragement and assistance. His guidance, encouragement, help and fi support have been invaluable throughout all the process. Especially, during my pregnancy, childbirth and caring for my daughter, it hardly seemed possible to reach the end of this long process without him. His insight to scientific research, and the way to carry it out, as well as his serious work style have greatly inspired and effected me and will continue to guide me through my life. I would like to express my gratitude to Prof. Chr. Diedrich for the effort of spending his leisure time on examining and judging this thesis, and also to the other members of the examination committee for their interest in my work and for the discussions. I highly appreciate the fi support provided to me during the years in form of a matching funds scholarship by Deutscher Akademischer Austauschdienst and Institut fu¨r Automation und Kommunikation e.V. Magdeburg, and a Graduiertenfo¨rderungsstipendium of Nordrhein-Westfalen. I express my acknowledgements to the following individuals in Hagen for their friendship and help in my study and daily life: my colleagues Ms. Renate Zielinski, Ms. Jutta Du¨ring, Dr. Meizheng Gao, Dr. Zhong Li, Dr. Ping Li, Dr. Wei Zhang, Ms. Hong Li, Dr. Martin Skambraks, Ms. Xia Wang, Dr. Shujun Li, Dr. Jianguo Ding, Dr. Yi Zhao, my friends Mrs. Elke Kaemmerer and Mrs. Dorina Griesenback who helped me very much by looking after my daughter, as well as my Chinese friends of the Yine Xu family and the people of the Lotus and Seilersee China restaurants in Hagen and Iserlohn, who are also brothers and sisters in Jesus. My very special thanks to Dr. Roman Gumzej for his work on Specification PEARL, and to the Treppmann family for years of delivering and explaining the Holy News to our family and helping us in many ways, especially Mrs. Martina Treppmann for her willingness to spend her precious time on reading and correcting the draft of this thesis. In addition, special thanks also go to my wonderful landlords Bernhard and Katharina Moneke, my former landlords Hans and Anna Siering, who were for me just like German parents looking after us in work and daily life. There are no words to express my thanks to my parents in China for their mental support and unconditional love during my years of study in Germany, also to my sister and brother for their help in taking good care of my parents so that I could concentrate on my study, and to my husband Youyi Pan for giving me energy to work and keeping me sheltered and happy. weiterlesen