1. Xipeng Hu:
Department of Mathematics, Nanjing University of Aeronautics and Astronautics, Nanjing, China; Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles (NUAA), MIIT, Nanjing , China
2. Lingping Zhong:
Department of Mathematics, Nanjing University of Aeronautics and Astronautics, Nanjing, China; Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles (NUAA), MIIT, Nanjing , China