1,2 3 1 3 M U X iaoxia , D ONG Xinghui , CHA I Xuqin g , LI Jun tao . College of Computer and Information Engineering Henan Normal University Xinxiang China (1 , , 453 007, ; . Key Laboratory of Artificial Intelligence and Personalized Learning in Education of Henan Province 2 , Henan Normal University Xinxiang China . College of Mathematics and Information Science , 453 007, ; 3 , Henan Normal Un