1. Ministry of Education Key Laboratory for Intelligent Analysis and Security Governance of Ethnic Languages, School of Information Engineering, Minzu University of China, Beijing, China
2. School of Mathematical Sciences, Inner Mongolia University, Hohhot, China
3. Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, U.K.
4. School of Artificial Intelligence and Automation, Autonomous Intelligent Unmanned System Engineering Research Center of Education Ministry of China, Image Processing and Intelligent Control Key Laboratory of Education Ministry of China, Huazhong University of Science and Technology, Wuhan, China