1. College of Electrical and Information Engineering, Hunan University of Technology, Zhuzhou, China
2. Key Laboratory for Electric Drive Control and Intelligent Equipment of Hunan Province, Zhuzhou, China
3. Key Laboratory of Image Processing and Intelligent Control of Ministry of Education of China, School of Automation, Huazhong University of Science and Technology, Wuhan, China
4. Department of Radiation Oncology, University of Texas Southwestern Medical Centre, Texas, USA