Foremost I would like to express my gratitude to Prof. Siegfried Selberherr who is responsible for the wonderful working environment and the perfect infrastructure at the Institute for Microelectronics. He always visualized important longterm aims and never got lost or distracted by bureaucratic details. In such a way he was always open to suggestions and very flexible in dealing with the specific needs of each student. This for each student different balance between freedom and pressure helped greatly to keep the motivation high and to guarantee the best possible outcome for each person and each project. I am also grateful to Prof. Dietmar Dietrich who was willing to serve on my examining committee on a very short notice.
Furthermore, I would like to thank all members of the institute for contributing to such an inspiring and pleasant atmosphere. I will never forget the good times I spent with my colleagues Rainer Sabelka, Heinrich Kirchauer, Rudi Strasser, Christian Harlander, Andi Hössinger, and Klaus Dragosits during the many interesting lunch hours. Rainer was always a great help and our time as system administrators was a lot of fun due to his many creative puns and funny jokes. Heinrich taught me how to really play badminton and Klaus always found intriguing stories on the verge of truthfulness. Rudi was always ready to entertain us all with a joke, a game, or a song. I also thank my first roommate Ernst Leitner who taught me most details about HP-UX and other things. With my other roommate Tibor Grasser I enjoyed many fruitful discussions during our special lunches at the ``Wok'' about all things in life. With Goran Kaiblinger I had a great colleague during night times. It was always interesting to see who would stay awake longer through the nights at the institute. Gerhard Schrom was the source of many original ideas and he served as an excellent partner for great discussions. Christian Troger was a colleague who was never tired of helping others. Regarding my work on mesh generation I would like to particularly mention Ernst Leitner, Wolfgang Pyka, Bernhard Haindl, and Robert Kosik who contributed a great deal to this thesis.