1. Alibaba Group and the Alibaba-NTU Joint Research Institute, Nanyang Technological University, Singapore
2. School of Computer Science and Engineering, Nanyang Technological University, Singapore
3. Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
4. School of Computer Science and Engineering, Alibaba-NTU Joint Research Institute, and Active Living for the Elderly, Nanyang Technological University, Singapore
5. Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea