Muren was born in 1982. He is currently work- ing toward the Ph.D. degree in School of Mathe- matical Sciences, Inner Mongolia University, China. His research interests include data envel- opment analysis and fuzzy mathematics. E-mail: muren@imut.edu.cn Corresponding author.Zhanxin Ma was born in 1970. He is received his Ph.D. degree in School of Management from Dalian University of Technology in 1999. Now he is a professor in School of Economics and Management, Inner Mongolia University. His research interests include comprehensive eva- luation, data envelopment analysis and multi- objective decision making. E-mail: em_mazhanxin @imu.edu.cn Wei Cui was born in 1981. She is currently working at Inner Mongolia University of Tech- nology. Her research interests include waves the- ory and mathematical modelling. E-mail: cuiwei_math@yahoo.cn