1. Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering, College of Computer and Information Technology, China Three Gorges University, Yichang, China
2. Department of Obstetrics and Gynecology Ultrasound, Renmin Hospital, Wuhan University, Wuhan, China
3. School of Computer Science, Wuhan University, Wuhan, China
4. School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, China