Frequency assignment : models and algorithms

topics, frequency assignment and network design gave me the opportunity to extend my knowledge to the whole area of operations research and telecommunication.The research on telecommunication network design resulted in three articles [56,86,132] that are not part of this thesis (they appeared in the Ph.D. thesis of Robert van de Leensel [131]).Speaking of Robert, a special word of thanks should be devoted to him.He was for almost 4 years my roommate and co-researcher.The afternoons that we locked the door, and discussed research topics together are worthwhile remembering.They were pleasant and productive at the same time.Many times, Robert acted as guinea-pig to test the validity of new ideas.Besides the research activities, I also indebted thanks to him for our discussions on varying topics, the joint travel experiences (especially in the U.S.A. and Israel), and last but not least his friendship.Besides the already mentioned people, I have to thank the other members of the Operations Research group in the years 1995-1999: Joris van de Klundert, Ron van der Wai, Rudolf Miiller, Jos Sturm and Jan-Willem Goossens.They were always available to answer my questions.Of course, also many thanks to the other members of the Department of Quantitative Economics for the pleasant contacts.Furthermore, I have to thank the students in Econometrics for their interest in my research project.For four years I had the opportunity to teach them the basics and more advanced levels of programming in C+ + .Without mentioning particular students, very pleasant contacts originate from these courses.I also have to acknowledge some people from outside Maastricht.A couple of people served as hosts during the trip with Robert through the United States of America.The (financial) support of Martin Savelsbergh (Georgia Institute of Technology), Rutgers University, Oktay Giinliik (AT&T Labs), Daniel Bienstock (Columbia University), David Williamson (IBM T.J. Watson Research Center), and 'Raghu' Raghavan (US West Telecommunications) provided that our trip ended successfully.The visit of the INFORMS Israel conference was financially supported by Shell Nederland.Tot slot gaat mijn dank uit naar mijn familie en vrienden in Schoonhoven en omgeving.In het bijzonder moet ik mijn ouders en mijn zus Cora bedanken voor hun niet-aflatende steun en belangstelling voor mijn onderzoek en onderwijs.Veel dank ben ik verschuldigd voor hun ondersteunende activiteiten, zoals het vele wassen en strijken als ik weer eens met een uitpuilende tas met wasgoed thuiskwam.In de toekomst hoop ik jullie daar niet al te vaak meer mee lastig te vallen.Finally, my latest but not least word of thanks has to go to our Creator, Who among all other things He did for me, talented me with the gift for mathematics.Without His never-ending aid and assistance, I would not have been able to complete this thesis.