1. School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, People's Republic of China
2. Chongqing Technology Innovation Center, Northwestern Polytechnical University, Chongqing, People's Republic of China
3. MOE Key Laboratory for Complexity Science in Aerospace, Northwestern Polytechnical University, Xi'an, People's Republic of China
4. School of Mathematics, Xi'an University of Finance and Economics, Xi'an, People's Republic of China