Dissertation zur Erlangung des akademischen Grades

I would like to thank my colleague Dr. Martin Kempa and my supervisor Prof. Dr. Volker Linnemann for the excellent cooperation, many helpful suggestions, and reviews. Special acknowledgments go to Volker Linnemann for the steady support even besides this project and to Henrike Schuhart for the fruitful discussions we had in the last years. A larger project like a doctoral thesis in computer science cannot be realized without many helping hands from student workers. I greatly appreciate their results that we gained together in many meetings, discussions and code walkthroughs leading to several bachelor and diploma theses. Especially, I would like to thank (in alphabetic order) Patrick Bär, Konstantin Ens, Chu Danxing, Timm Gehrmann, Khaled al Hayja, Ivo Iken, Florian Massel, Nina Moebius, Alexander Pfalzgraf and Philipp Stursberg. Many thanks go to Prof. Dr. Stefan Fischer for his co-review and to Prof. Dr. Erik Maehle for chairing my final examination. Last but not least, special thanks go to to the whole team of the Institute of Informatio