for their guidance and all the support throughout my whole Ph.D. journey. It has been a very enriching time spent learning from each of them. Through the guidance of A/Prof. Xiao, I have learnt a lot about how to conduct good research, the importance of perseverance in research, and effective communication styles. And through the guidance of Dr. Li, I learnt to appreciate the motivations behind solving research problems related to real-world industry problems and the importance of patience in research. Having being supervised by A/Prof. Bhowmick two years ago, I have also learnt about effective writings and a great deal about spirit of research and education. I would also like to thank my friends Dr. Yequan Wang and Dr. Andrew Ho, both of whom had provided huge timely help at certain points of this journey. Dr. Yequan Wang had introduced me to the field of deep learning and the plenty of opportunities there, and spared no effort in ensuring our collaboration work went well. Dr. Andrew Ho promoted opportunities that aimed to spur the pace of my Ph.D. process, and worked hard to ensure that our collaborations moved in a prompt fashion. Very importantly, I would also like to thank my parents and my girlfriend Ling for their immensely patient support and understanding throughout this period, especially since I was away from home most of the time. Without that, my Ph.D. journey would have been much more challenging. Finally, this journey would not be as interesting without the lab colleagues and friends I met along the way, whom had also helped me in one way or another.