1. School of Mathematical, Physical and Computational Sciences, University of Reading, Reading, U.K.
2. College of Overseas Education, Changzhou University, Changzhou, Jiangsu, China
3. Department of Economics, University of Connecticut, Storrs, CT, USA
4. Qian Xuesen College, Nanjing University of Science and Technology, Nanjing, China
5. Nanjing University of Information Science and Technology, Nanjing, China