[1] Shanghai Univ Finance & Econ, Sch Stat & Management, Shanghai 200433, Peoples R China
[2] Chinese Acad Sci, Acad Math & Syst Sci, Beijing 100190, Peoples R China
[3] Univ Calgary, Dept Math & Stat, Calgary, AB T2N 1N4, Canada
[4] Yunnan Univ Finance & Econ, Sch Math & Stat, Kunming 650221, Peoples R China