[1] Fudan Univ, Acad Engn & Technol, Shanghai 200433, Peoples R China
[2] Fudan Univ, Sch Comp Sci, Shanghai Key Lab Intelligent Informat Proc, Shanghai 200433, Peoples R China
[3] Swiss Fed Inst Technol, Dept Informat Technol & Elect Engn, CH-8092 Zurich, Switzerland
[4] Yiwu Res Inst Fudan Univ, Yiwu 322000, Zhejiang, Peoples R China