1. College of Computer Science, Sichuan University, Chengdu, Sichuan 610065, P.R. China
2. School of Computer Science, Chengdu University of Information Technology, Chengdu, Sichuan 610225, P.R. China
3. CuraCloud Corp., Seattle, WA 98104, USA
4. Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China