Ke Tu is now pursuing his PhD in the Department of Computer Science and Technology, Tsinghua University, China. His recent research interests include image denoising, image enhancement and data mining. E-mail: hbli@ tsinghua.edu.cnHongbo Li received the PhD from Tsinghua University, China in 2009. He is currently an assistant professor with the Department of Computer Science and Technology, Tsinghua University, China. His research interests include networked control systems and intelligent control. Fuchun Sun received the PhD in 1998 from the Department of Computer Science and Technology, Tsinghua Uni- versity, China. Currently, he is a professor in the Department of Computer Science and Technology, Tsinghua University, China. His research interests include intelligent control, neural networks, fuzzy systems, variable structure control, nonlinear systems and robotics.