1. Department of Statistics Chongqing University of Technology Chongqing China
2. Department of Statistics The Chinese University of Hong Kong Hong Kong China
3. Centre of Data Innovation Research, Department of Physics, Astronomy & Mathematics, School of Physics, Engineering & Computer Science University of Hertfordshire College Lane Hatfield UK
4. Business School University of Hertfordshire Hatfield UK
5. Department of Applied Mathematics The Hong Kong Polytechnic University Hong Kong China