[1] Sobolev Inst Math, 4 Acad,Koptyug Ave, Novosibirsk 630090, Russia
[2] Tomsk State Univ, Pr Lenina 36, Tomsk 634050, Russia
[3] Novosibirsk State Agrarian Univ, Dobrolyubova St 160, Novosibirsk 630039, Russia
[4] Hebei Normal Univ, Ctr Topol & Geometry Based Technol, Sch Math Sci, Shijiazhuang 050024, Peoples R China
[5] Beijing Inst Math Sci & Applicat, Beijing 101408, Peoples R China