First of all I want to thank my parents for financially and personally supporting my studies and for enabling my stay here in Madrid.
I am also very grateful to my advisor, Dr. Andres Marin Lopez, for his support and guidance through my time here in Madrid and for his many valuable ideas during our discussions. Also I want to thank Prof. Johann Schlichter and Dr. Michael Koch from the TUM for their advice and for providing me with the official framework for this diploma thesis in Spain.
Many thanks to all my friends here in Madrid for supporting my thesis with their comments and ideas, and for their patience while I was busy with working. They all provided me with an excellent atmosphere to work and live during this year in Spain.