The contributions of the co-authors are as follows:• Dr. Yap provided valuable comments on the system and experiment design.• Dr. Ding and Dr. Wu assisted in the data collection and preparation.• Dr. Tan and Dr. Yuan suggested the topic of the large-vocabulary problem and revised the manuscript. • I designed the interaction detection system, performed all the experiment work, and wrote the manuscript draft.Chapter 4 is published as Suchen Wang, Kim-Hui Yap, Junsong Yuan, and Yap-Peng Tan. Discovering Human Interactions with Novel Objects via Zero-Shot Learning. In Proceedings of the Conference on Computer Vision and Pattern Recognition (CVPR), IEEE, 2020.The contributions of the co-authors are as follows:• Dr. Tan and Dr. Yap supervised me on the overall research direction.• I developed the algorithm, finished the coding work, analyzed the experimental results, and wrote the manuscript drafts. •