1. Big Data Institute and the Shandong Fundamental Research Center for Computer Science, Qilu University of Technology, Jinan, China
2. School of Cyber Science and Engineering, Southeast University, Nanjing, China
3. School of Computer Science and Technology, Shandong University, Qingdao, China
4. School of Information Science and Technology, The Pennsylvania State University, University Park, PA, USA
5. Tacoma School of Engineering and Technology, University of Washington, Seattle, WA, USA