1. National Engineering Laboratory for Big Data System Computing Technology, College of Computer Science and Software Engineering, Shenzhen University, Shenzhen, China
2. Joint NTU-UBC Research Centre of Excellence in Active Living for the Elderly (LILY), Nanyang Technological University, Singapore
3. Department of User Growth and Operations, Jing Dong Retail, Beijing, China
4. Joint NTU-UBC Research Centre of Excellence in Active Living for the Elderly (LILY) & School of Computer Science and Engineering, Nanyang Technological University, Singapore
5. College of Computer Science, Chongqing University, Chongqing, China