Department of Computer Science, Utah State University, Logan, UT 84322-4205, USA. mjiang@cc.usu.edu|Department of Computer Science, Utah State University, Logan, UT 84322-4205, USA. mjiang@cc.usu.edu|Department of Computer Science, Utah State University, Logan, UT 84322-4205, USA. mjiang@cc.usu.edu|Department of Computer Science, Utah State University, Logan, UT 84322-4205, USA. mjiang@cc.usu.edu