This thesis would not have been realized without the substantial support and contribution of many people, to whom I cannot but feel deeply grateful.
First of all, I thank Professor Demetrios Sampson, initial supervisor yet continuous mentor of my doctoral thesis, for his trust, insights and patience during the last 4 years; his continuous guidance to my research; and his high investment towards helping me improve myself in many ways. For all these, I am indeed thankful.
I would also like to thank my very good friend Panagiotis Zervas for supporting me throughout this process, especially during the difficult start. His advice greatly helped me to carry on.
A special thank you goes out to my close friends that were always there when I needed them. Most of all, Helen, I thank you for your everlasting care and support; you are my hero.
Last, but surely not least, I would like to express my absolute love and gratitude to my family for their everlasting love, their encouragement, and their belief to my capabilities. You made it all possible.
(EL)
Natural Sciences ▶ Computer and Information Sciences Information Systems
(EN)
University of Peiraeus
