基金Supported by the NNSF of China(Grant No.:10171093)the National 973 Fundamental Research Program on Financial Engineering(Grant No:G1998030418)the Doctoral Program Foundation of Institute of High Education.
基金Supported by the National Natural Science Foundation of China(61403288)China Postdoctoral Science Foundation funded project(2014M562076)The Fundamental Research Funds for the Central Universities(WUT:2017IA004)
基金supported by the Provincial Natural Science Research Project of Anhui Colleges(KJ2013A137)the Natural Science Foundation of Anhui Province(1408085MA07)the PhD Research Startup Foundation of Anhui Normal University(2014bsqdjj34) which facilitated the research visit of the first author to McMaster University,Canada