FOREWORD I would like to thank everyone who has assisted and supported me during the writing of this dissertation. First of all, I would like to take this opportunity to thank my superior, Dr. Antonios Roumpakis, for his beyond and steadfast support on my research. With great patience, motivation, and encouragement, he helped me in doing this research. I give my credit to him for the opportunity he gave to mentor me. Without his in-depth guidance, this research would not have been possible. I also express my gratitude to the parties concerned, including the company and those who: