I feel greatly indebted to my friend and an excellent person Clarisse Kagoyire for always saying yes whenever I needed her for software related issues. I am thankful to Bas Retsios for helping me in programming. I feel highly obliged to Prof. Adrian Baddeley and Rolf Turner for their very kind response and always helping me whenever I wrote to them about sofware related problems.My heartiest and sincere gratitude are paid to Theresa van der Boogaard, Marie Chantal, Bettine Geerdik and Marion Pierik for their professional as well as moral support. I am very thankful to Ginie Gerrits for always promptly responding to my travel related requests and making arrangements in almost no time. I am thankful to Helpdesk people, particularly Mr. Aiko Mulder, for their technical support. And thanks to Roeloff schoppers for his cheerful greetings every day. I am thankful to my office mates and friends Xudan Xu, Biao, Meisam and Hajer for their invaluable company, and to Sumbal, Coco, Liang and Rahul for their cheering talks. My special thanks are to my lovely friend Alka, her husband Amit and her daughter Bhuvan for having been like a blessing to me. I am also very thankful to Ms. Loes Minkman of NUFFIC for her appreciations and encouraging words which meant a lot to me.