1. College of Electronic Information & Control Engineering, Beijing University of Technology, No. 100, Pingleyuan, Chaoyang District, Beijing 100124, China
2. Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing 100124, China
3. Engineering Research Center of Digital Community, Ministry of Education, Beijing 100124, China
4. Department of Information Engineering and Automation, Hebei College of Industry and Technology, No. 626, Hongqi Street, Qiaoxi District, Shijiazhuang 050081, China