1School of Electronic and Information Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China
2Experiment Teaching Center on Computer Science, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China
3Gansu Provincial Engineering Research Center for Artificial Intelligence and Graphics & Image Processing, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China;
4Gansu Provincial Key Laboratory of System Dynamics and Reliability of Rail Transport Equipment, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China