STRUCTURAL HEALTH MONITORING FOR BRIDGES USING ADVANCED DATA ANALYSIS FOR PROCESS NON-LINEARITY AND NON- STATIONARITY By ERMIAS BIRU Bachelor of Science in Industrial Engineering

iii ACKNOWLEDGMENTS I would like to express my deepest appreciation to my advisor, Dr. Zhenyu (James) Kong, for his continuous support, patience and excellent guidance throughout my study. I learned many important lessons from him and he is always there to listen, advise and motivate me. I would like to thank Dr. Tieming Liu and Dr. Tyler Ley for serving on my thesis committee as well as for their valuable input throughout my study and during my thesis defense. I am grateful to Dr. Ley for his support in providing the data used for analysis. I am also grateful for the support and guidance that I had from my senior and doctoral students Mr. Asil Oztekin and Mr. Omer Beyca. I am also thankful to Mr. Mahmoud Z. Mistarihi for his suggestion and help in organizing the document. This thesis would not have been possible without the help of my parents Mrs. Aberu Abtew and Mr. Belay Biru who encouraged me from the initial to the final level of my study. I am also grateful to the support I had from my sisters and brothers. Woldesenbet, and others who supported me in any respect during my study.