1. School of Cyberspace Science and Technology, Beijing Institute of Technology, Beijing, China
2. School of Automation, Guangdong University of Technology, Guangzhou, China
3. School of Information Engineering, Minzu University of China, Beijing, China
4. School of Computer Science, University of Guelph, Guelph, Canada
5. School of Computer Science and Engineering, Nanyang Technological University, Jurong West, Singapore