1. The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
2. School of Economics and Statistics, Guangzhou University, Guangzhou, China
3. Department of Applied Mathematics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
4. School of Electrical Engineering, Computing and Mathematical Sciences (EECMS), Faculty of Science and Engineering, Curtin University, Bentley, WA, Australia