1. School of Information and Engineering, Sichuan Tourism University, Chengdu, China
2. School of Computer Science, Nanjing University of Science and Technology, Nanjing, China
3. College of Economics and Management, Shanghai Ocean University, Shanghai, China
4. School of Computer Science and Technology, Shandong Technology and Business University, Yantai, China
5. Computer Science Department, Wenzhou University, Wenzhou, China
6. College of Electronic Information and Automation, Civil Aviation University of China, Tianjin, China