This book is the result of my PhD studies at the Helsinki University of Technology. I started working towards a doctoral degree right after graduation from the University of Helsinki in 1999. I was supposed to write a thesis in law. Now I need to apologize my then-supervisors profes- sor Niklas Bruun and docent Pekka Timonen not to complete the thesis at the law faculty in four years as was once planned. What happened was that I met my future academic mentor, professor Jukka Kemppinen, who had just started his professorship at the Helsinki University of Technology. He convinced me to change my plans and my university in.
