A Language-based Approach to Model

iAcknowledgements It was my greatest fortune to have Zhenjiang Hu and Masato Takeichi as my advisors. During my Ph.D. studies, Prof. Hu spent countless hours advising and helping me not only on my research but also on many aspects of my life. His attitude towards research and life influences me to be what I am today, and will continue to guide me in my future career. On the other hand, Prof. Takeichi’s wisdom and perspective greatly helped me to keep my research in the right direction, and his kindness to students constantly inspired me forward. They both are great scholars for me to follow beyond the thesis. I would like to express my deepest gratitude to them at the very beginning of my thesis. I would also like to thank my collaborators. Dongxi Liu taught me many basic techniques in research while contributed a lot to the early work of this thesis. Hui Song extended the research to a broader scope and made use-ful feedbacks to push the work forward. Haiyan Zhao provided invaluabl