1. College of Computer Science, Chongqing University, Chongqing, China
2. Department of Computing, The Hong Kong Polytechnic University, Hong Kong
3. Sixty-third Research Institute, National University of Defense and Technology, Nanjing, China
4. Department of Quartermaster and Purchase, ALA, Chongqing, China
5. College of Physics and Electronic Information Engineering, Yanan University, Yanan, China