Department of Computer Science, University of Akron, Akron, OH 44325, USA. duan@uakron.edu|Department of Computer Science, University of Akron, Akron, OH 44325, USA. duan@uakron.edu|Department of Computer Science, University of Akron, Akron, OH 44325, USA. duan@uakron.edu|Department of Computer Science, University of Akron, Akron, OH 44325, USA. duan@uakron.edu|Department of Computer Science, University of Akron, Akron, OH 44325, USA. duan@uakron.edu