Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA. chenyh@cis.uab.edu|Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA. chenyh@cis.uab.edu|Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA. chenyh@cis.uab.edu|Department of Computer and Information Sciences, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA. chenyh@cis.uab.edu