Preface

So then it is not of him who wills, nor of him who runs, but of God who has mercy. Romans 9,16 While this Bible verse above primarily tells us about attaining salvation, its truth may be discovered in everyday life. Our salvation is not simply the product of human will and effort, but a gift of God. In a similar way, God’s undeserved goodness can be observed in many areas of a person‘s life and activities. In research work this may be even more apparent, where the outcome of a challenging initiation usually can not be predicted. Sometimes the result of a thoroughly performed, promising work becomes average, and at other times a sudden idea is accepted and honored. I believe that writing this thesis was made possible by the grace of God. I should like to acknowledge several people who have contributed to this thesis in some way. First of all, I should like to thank my supervisor Tibor Gyimóthy, for providing interesting research topics and aims, and for his guidance over the years. Then I would like to express my gratitude to Árpád Beszédes and Rudolf Ferenc, with whom I discussed aspects of my research, for their valuable ideas and the time spent on joint work. My thanks also goes to my colleagues and friends, including Fedor Szokody, Judit Jász, David Curley, Péter Siket, István Siket, Patrícia Frittman and Richárd Dévai. I would like to thank Martin Gogolla as well, for his kind hospitality and support during the time I spent in his research group in Bremen. I am also grateful to András Kolozsi, Ferenc Havasi, Miklós Árgyelán and Zoltán Tasnády-Szeőcs, who are friends of mine; and especially to my love Katalin Horváth for her patience and support. Finally, I would like to thank my family for their continuous support and encouragement. ii