1. School of Artificial Intelligence, Nanjing Vocational College of Information Technology, Nanjing, China
2. School of Computer, Jiangsu University of Science and Technology, Zhenjiang, China
3. Department of Computer Science, Royal Holloway University of London, Surrey, U.K
4. College of Tongda, Nanjing University of Posts and Telecommunication, Yangzhou, China
5. School of Tourism Management, Nanjing Institute of Tourism and Hospitality, Nanjing, China