The research work during Ph.D is a journey of positive attitude to live a life looking for a solution to the societal problem. I take this opportunity to thank everybody who helped me during this journey.I owe my sincere gratitude to many people in different ways that made it possible to complete my doctoral research. I would like to extend my appreciation to all who helped me to complete my research successfully.I thank the Almighty for the wisdom and perseverance that He has bestowed upon me during the research period and indeed throughout my life.I express my deep gratitude towards my Research Supervisor Dr. L.R. Sudha, Associate Professor, Department of Computer Science and Engineering, Annamalai University for her constant encouragement, kind support, her technical wisdom, positive approach, and innovative thinking. I experienced that her suggestions are well thought and precise. She is my true mentor, philoshoper, and guide.I would like to thank my family members, my fellow researchers and well wishers for their suggestions and timely help. I also thank all teaching and non-teaching staff of the Department of CSE, who helped me to complete this book.