Xu Zhou, born in 1986. He received an M.S. degree in Applied Mathematics from Hebei University in 2013. He is currently working toward a Ph.D. degree in Mining Engineering in the College of Mining Engineering, North China University of Science and Technology. His research interests include data mining and machine learning. Email address: sxzhouxu@126.com (Xu Zhou). Postal address: 21 Bohai Road, Caofeidian Xincheng, Tangshan, Hebei, 063210, China