1. College of Economics and Management, Northwest A&F University, Yangling, China
2. Faculty of Management and Economics, Dalian University of Technology, Dalian, China
3. Department of Applied Economics, University of Minnesota, Minneapolis, MN, USA
4. School of Electrical and Information Engineering, University of Sydney, Sydney, NSW, Australia
5. Department of Systems Management and Engineering, Pukyong National University, Busan, Republic of Korea