1. Faculty of Engineering, The Hong Kong Polytechnic University (PolyU), Hong Kong, Hong Kong
2. Department of Computer Science, University of Liverpool, Liverpool, U.K.
3. School of Electrical and Electronic Engineering. Nanyang Technological University, Singapore, Singapore
4. Department of Computer Science, The University of Hong Kong, Hong Kong, Hong Kong
5. Faculty of Engineering, and the Research Institute for Smart Ageing, The Hong Kong Polytechnic University (PolyU), Hong Kong, Hong Kong