1. College of Electronic and Information, Qingdao University, Qingdao 266071, China
2. Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266003, China
3. Department of Stomatology, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266003, China
4. Department of Computer Science and Engineering, Sejong University, Seoul 05006, Korea
5. Department of Electronic Engineering, Kwangwoon University, Seoul 01897, Korea