Department of Computer Science & Engineering, University of Connecticut, Storrs, CT 06269, USA. yin@engr.uconn.edu|Department of Computer Science & Engineering, University of Connecticut, Storrs, CT 06269, USA. yin@engr.uconn.edu|Department of Computer Science & Engineering, University of Connecticut, Storrs, CT 06269, USA. yin@engr.uconn.edu