1. School of Computer and Control Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
2. Research Center of Fictitious Economy and Data Science, Chinese Academy of Sciences, Beijing 100080, China
3. College of Information Sciences and Technology, University of Nebraska at Omaha, Omaha, NE 68118, USA
4. Department of Digital Technology Management, School of Business Administration, Hoseo University, 12, Hoseodae-gil, Dongnam-gu, Cheonan-si, South Korea
5. Department of Global Entrepreneurship, School of Business Administration, Hoseo University, 12, Hoseodae-gil, Dongnam-gu, Cheonan-si, South Korea
6. College of Business, Korea Advanced Institute Science and Technology, Dongdaemum-gu, Seoul 130-722, South Korea