WANG Lu1; YANG Jie2; XIONG Sheng-wu3（1.School of Information Engineering; Shandong Agriculture University; Taian 271018; China; 2.Department of Mechanical and Electrical Engineering; Shandong University of Science and Technology; Taian 271019; 3.School of Computer Science and Technology; Wuhan University of Technology; Wuhan 430070; China）