[Yang, Jiumin; Liu, Caixia; Zhang, Yi] Cent China Normal Univ, Fac Artificial Intelligence Educ, Wuhan 430079, Peoples R China.
[Wu, Changcheng] Cent China Normal Univ, Natl Engn Res Ctr Learning, Artificial Intelligence Educ Div, Wuhan 430079, Peoples R China.
[Wu, Changcheng] Sichuan Normal Univ, Coll Comp Sci, Chengdu 610101, Peoples R China.
[Pi, Zhongling] Shaanxi Normal Univ, Minist Educ, Key Lab Modern Teaching Technol, 199 South Changan Rd, Xian 710062, Shaanxi, Peoples R China.