1. Faculty of Engineering and Information Technology, University of Technology Sydney, 1994 Sydney, New South Wales, Australia, (e-mail: yongshun2512@hotmail.com)
2. Faculty of Engineering and Information Technology, University of Technology Sydney, 1994 Sydney, New South Wales, Australia, (e-mail: Zhibin.Li@student.uts.edu.au)
3. FEIT, University of Technology Sydney, 1994 Sydney, New South Wales, Australia, (e-mail: jian.zhang@uts.edu.au)
4. School of Computer Science, University of Technology Sydney, 1994 Sydney, New South Wales, Australia, 2007 (e-mail: wei.liu@uts.edu.au)
5. School of Software, Shandong University, 12589 Jinan, Shandong, China, (e-mail: ylyin@sdu.edu.cn)
6. Urban Computing Group, Microsoft Research Asia, 216064 Beijing, Beijing, China, (e-mail: msyuzheng@outlook.com)