1. School of Computer and Technology, Harbin University of Science and Technology, Harbin, Heilongjiang 150080, P. R. China
2. School of Economics and Management, Northeast Agricultural University, Harbin, Heilongjiang 150030, P. R. China
3. Wartime Auditing and Audit Information T&R Section, Military Economy Academy, Wuhan, Hubei 430035, P. R. China