1. Department of Information and Communication Engineering, School of Informatics, Xiamen University, Xiamen, China
2. Department of Computer Science, School of Informatics, Xiamen University, Xiamen, China
3. Department of Statistics and Actuarial Science, The University of Hong Kong, Hong Kong, SAR, China
4. Center for Smart Health, School of Nursing, The Hong Kong Polytechnic University, Hong Kong, SAR, China