1. School of Statistics, Chengdu University of Information Technology , Sichuan, 610103, China
2. College of Computer Science, Sichuan University , Sichuan, 610065, China
3. School of Electronic and Information Engineering, Suzhou University of Science and Technology , Jiangsu, 215009, China
4. Jiangsu Key Laboratory for Elevator Intelligent Safety , Jiangsu, 215506, China