Information Systems Department, College of Computing Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA. songhua.xu@njit.edu|Information Systems Department, College of Computing Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA. songhua.xu@njit.edu|Information Systems Department, College of Computing Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA. songhua.xu@njit.edu