1. School of Information and Technology, Luoyang Normal University, Luoyang 471934, China
2. Henan Key Laboratory for Big Data Processing & Analytics of Electronic Commerce, Luoyang 471934, China
3. Computer School, Hubei University of Arts and Science, Xiangyang 441000, China
4. School of Fundamental Science and Engineering, Waseda University, Tokyo 169-8050, Japan
5. Capinfo Company Ltd., Beijing 100010, China