中文摘要：

FENG Ding-Cheng Received his bachelor degree in automation from Harbin Institute of Technology in 2008. He is a Ph. D. candidate in control science and engineering in the Department of Automation, Tsinghua University. His research interest covers structure learning, variational inference, causal inference, and feature selection. E-maih dingchengfeng@gmail.com CHEN Feng Received his bachelor and master degrees in automation from Saint- Petersburg Poly-Technic University, Saint- Petersburg, Russia, in 1994 and 1996, respectively, and his Ph.D. degree in automation from Tsinghua University, China, in 2000. He is currently a professor with the National Laboratory for Information Science and Technology, Department of Automation, Tsinghua University. His re-search interest covers computer vision, video processing, and variational inference and structure learning in graphical models. Corresponding author of this paper. E-mail： chenfeng@mail.tsinghua.edu.cn XU Wen-Li Received his bachelor degree in electrical engineering and his master degree in automatic control engineering from Tsinghua University, China, in 1970 and 1980, respectively, and his Ph. D, degree in electrical and computer engineering from the University of Colorado at Boul- der, USA, in 1990. He is currently a pro- fessor with the National Laboratory for In- formation Science and Technology, Depart-ment of Automation, Tsinghua University. His research interest covers automatic control, intelligent robot, and computer vision. E-maih xuwl~mail.tsinghua.edu.cn