1. Ph.D. Candidate, College of Management and Economics, Tianjin Univ., Tianjin 300072, People’s Republic of China.
2. Professor, College of Management and Economics, Tianjin Univ., Tianjin 300072, People’s Republic of China.
3. Assistant Professor, College of Management and Economics, Tianjin Univ., Tianjin 300072, People’s Republic of China (corresponding author).
4. Postgraduate, College of Management and Economics, Tianjin Univ., Tianjin 300072, People’s Republic of China.
5. Senior Engineer, China Electric Power Equipment and Technology Co., LTD., No. 8, Nanheng East St., Beijing 100052, People’s Republic of China.