1. Key Laboratory of Hunan Province for Internet of Things and Information Security, and the Key Laboratory of Intelligent Computing and Information Processing, Ministry of Education, Xiangtan University, Xiangtan, China
2. Department of Computer Science, University of Aberdeen, Aberdeen, U.K.
3. Institute of Artificial Intelligence, School of Computer Science and Informatics, De Montfort University, Leicester, U.K.
4. College of Systems Engineering, National University of Defense Technology, Changsha, China