Corresponding author. Chonghui Guo was born in 1973. He received the B.S. degree in mathematics from Liaoning University, China, in 1995, M.S. degree in op- erational research and control theory, and Ph.D. degree in management science and engineering from Dalian University of Technology, China, in 2002. He was a postdoctoral research fellow in the Department of Computer Science, Tsinghua University from 2002 to 2004. Now he is a pro- ;ssor of the Institute of Systems Engineering, Dalian University of echnology. His current research interests include machine learning, ata mining, pattern recognition, and systems optimization. E-mail: dlutguo@dlut.edu.cn Yunhui Zang was born in 1985. She is currently a master student of Dalian University of Tech- nology. Her research interest is data mining. E-mail: zangyunhui 1986 @ yahoo.com.cn