[1]School of Electronics and Information EngineeringSouthwest University, Chongqing 400715, P. R. China;
[2]Key Laboratory of Machine Perception and Children's Intelligence Development Chongqing University of Education Chongqing 400067, P. R. China;
[3]School of Electronics and Information Engineering Southwest University, Chongqing 400715, P. R. China;
[4]Department of Mathematics Texas AM University at Qatar, Qatar;