Acknowledgement

to express my gratitude towards many people whose insightful suggestions, contributions enabled me to enhance my work at each stage. In addition to this, I wish to acknowledge the assistance provided by IDA of Linkoping University. I am deeply indebted to my supervisor Mr. Chandan Roy from Linköping University whose help, suggestions and encouragement at all time of research enabled me to successfully complete my master thesis. I specially thank Dr. Åke Sivertun and Dr. Rita Kovordányi for their guidance throughout the study. I would also like to thank all my friends from Linköping University, roommates Tirumal Kumar, Sujit, Karteek and Krishna Mohan for being surrogate family during the stay in Sweden. Especially, I am grateful to my parents whose love and affection has been great support for each and every success in my career. Without their cooperation and willingness to share data and assist in the field this research would not have been possible