1. School of Public Administration, Jiangxi Normal University, Jiangxi, Nanchang, China
2. School of Computing, National University of Singapore, Queenstown, Singapore
3. Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
4. School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
5. Yong Loo Lin School of Medicine, National University of Singapore, Queenstown, Singapore
6. State Key Laboratory of Networking and Switching Technology, BUPT, Beijing, China