1. School of Computer and Information Technology, Beijing Jiaotong University, Beijing, China
2. State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, China
3. Department of Electrical and Computer Engineering at Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
4. Department of Engineering, University of Cambridge, Cambridge, U.K.
5. Engineering Research Center of Autonomous Unmanned System Technology, Ministry of Education, Anhui, China
6. Hong Kong Baptist University, Hong Kong, China
7. Faculty of Innovation Engineering, Macau University of Science and Technology, Macau, China