基于非线性降维聚类的线上操舞课学生运动表现量化研究

A Quantitative Study on Students’Motion Performance in Online Dance Course Based on Non-linear Dimensionality Reduction and Clustering

目的:通过线上操舞课选修学生肢体表现与表情表达的在线评价数据构建操舞评价模型,开展应用研究。方法:以76名普通大学生为研究对象,要求受试者参加2轮不同类型的啦啦操课中和课后训练。根据受试者的反馈视频,由专家进行评分,并采集受试者韵律配合程度、动作力度、动作标准度、动作完整度、眼睛、唇部、手部和腿部与心理紧张程度的量化值,以得出视觉量化分,并对除视觉量化分外的各项数据进行非线性降维并聚类,形成考核分类结果。结果:(1)视觉量化分与综合运动表现专家评分具有显著相关性(花球啦啦操:r=0.931,P<0.01;自由舞蹈:r=0.942,P<0.01),且不存在显著差异(花球啦啦操:t=-1.665,P=0.098;自由舞蹈:t=0.552,P=0.581);(2)通过非线性降维并聚类的方法将样本分成具有区分度的3个层级、6个类别,每个类别在相同训练时间(1~72 h)下提升程度不同。结论:基于非线性降维聚类分析的线上操舞教学学生运动表现评价方法对专家打分具有较大程度的可替代性,对不同操舞类型具有适用性,具有分析粒度细、速度快、精度高、训练提升路径明确等优点,可适用于线上操舞类运动项目教学考核与评价。

Objective:To conduct a dance evaluation model based on the online dance teaching evaluation data of physical performance and emotional expression of students.Methods:76 college students participate in two rounds of different types of cheerleading in class and after class.According to the videos uploaded by the subjects,the score of comprehensive exercise performance,prosodic coordination,action intensity,action standard,action completeness,and the quantized values of eyes,mouth,hands,legs and psychological tension were evaluated for calculating the visual quantitative scores.The data except visual quantitative scores was clustered after non-linear dimensionality reduction and finally obtained a classification result.Results:(1)visual quantitative scores and the score of comprehensive exercise performance were correlated significantly(pom:r=0.931,P<0.01;free dance:r=0.942,P<0.01)and have no significant difference(pom:t=-1.665,P=0.098;free dance:t=0.552,P=0.581).(2)The method of non-linear dimensionality reduction and clustering can divide the samples into three distinct levels or six distinctive categories,each category has a different degree of improvement in the case of extending the same training time(1~72 h).Conclusions:The evaluation method based on non-linear dimensionality reduction and clustering has a great degree of substitutable for expert scoring.It has the advantages of fine analysis granularity,fast speed,high precision,clear training path and so on,and is applicable to various types of dances.Therefore,it is suitable for the assessment and evaluation of online dance teaching.