Department of Computer Science, New Jersey Institute of Technology, Newark, NJ 07102, USA. zhiwei@njit.edu|Department of Computer Science, New Jersey Institute of Technology, Newark, NJ 07102, USA. zhiwei@njit.edu|Department of Computer Science, New Jersey Institute of Technology, Newark, NJ 07102, USA. zhiwei@njit.edu|Department of Computer Science, New Jersey Institute of Technology, Newark, NJ 07102, USA. zhiwei@njit.edu