1. Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, SAR
2. Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, USA
3. Department of Electrical and Electronic Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, SAR
4. School of Energy and Environment, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR