武术专项技术练习对提高长拳套路教学效果的实验研究

通过实验组数据,揭示专项技术练习在武术长拳套路教学的重要性及必要性。为科学安排长拳教学结构、提高教学效果,增强学生体质,提供了一定的参考依据。     

竞技体操现场技术姿态特征识别系统

人体动作姿态的识别是当前研究的热点,而对于运动员技术姿态的计算是非常困难的但其应用十分广泛。针对竞技体操现场中运动员的技术姿态识别展开研究,通过监控设备对竞技体操现场进行图像采集,对图像进行关节点标定,利用加权量化矩阵表示技术姿态特征用以解决不同关节点的权重区分度问题,经过权重修正后的关节点相对坐标作为技术姿态特征用以解决标定关节点时产生的误差所造成的识别精度下降的问题,基于多种姿态特征建立技术姿态描述算子并构建特征数据库,用于训练基于支持向量机的多类分类器,以实现竞技体操现场中对体操运动员技术姿态特征的识别。实验表明,提出的方法实现了11种体操运动员运动姿态的特征识别,在识别效率和精度上具有令人满意的结果。     

Modeling Growth in Electronic Learning Environments Using a Longitudinal Random Item Response Model

In educational environments, monitoring persons' progress over time may help teachers to evaluate the effectiveness of their teaching procedures. Electronic learning environments are increasingly being used as part of formal education and resulting datasets can be used to understand and to improve the environment. This study presents longitudinal models based on the item response theory (IRT) for measuring persons' ability within and between study sessions in data from web-based learning environments. Two empirical examples are used to illustrate the presented models. Results show that by incorporating time spent within- and between-study sessions into an IRT model; one is able to track changes in ability of a population of persons or for groups of persons at any time of the learning process.     

天线扫描对TOPSAR辐射影响的校正方法

TOPSAR模式是合成孔径雷达的一种宽幅成像观测模式,其产品被广泛应用于海洋风场反演、洋流反演等定量化遥感。根据TOPSAR模式成像的特点,对经典雷达方程表达式进行适应性修正,并在此基础上提出一套适用于TOPSAR模式的辐射校正处理方法,给出一套完整的处理流程图。最后,利用国产高分三号SAR卫星的TOPSAR试验模式实测数据对文中提出的校正方法进行有效性的验证工作。     

The Multidimensionality of Measurement Bias in High-Stakes Testing: Using Machine Learning to Evaluate Complex Sources of Differential Item Functioning

Test developers and psychometricians have historically examined measurement bias and differential item functioning (DIF) across a single categorical variable (e.g., gender), independently of other variables (e.g., race, age, etc.). This is problematic when more complex forms of measurement bias may adversely affect test responses and, ultimately, bias test scores. Complex forms of measurement bias include conditional effects, interactions, and mediation of background information on test responses. I propose a multidimensional, person-specific perspective of measurement bias to explain how complex sources of bias can manifest in the assessment of human knowledge, skills, and abilities. I also describe a data-driven approach for identifying key sources of bias among many possibilities—namely, a machine learning method commonly known as regularization.     

近红外光谱分析原理、检测及定标技术简介

近年来,近红外光谱技术以其独特的优越性越来越受到人们的关注,已成为发展最快、最引人注目的分析技术之一.近红外光谱技术对样品的分析要通过校正模型的建立来实现,实验结果的准确性与定标模型的可靠性有直接的关系,所以如何建立一个准确、可靠的定标模型在近红外光谱技术使用中至关重要.     

论运动素质转移与运动项目迁移的关系* ——以健美操与体育舞蹈、体操为例

运动素质是可以相互转移的,各个运动项目需要的身体素质不尽相同,但他们之间都是可以相互转移的。通过描述了多个运动项目之间的身体素质之间的关系和转移,主要介绍了竞技健美操与体育舞蹈之间素质的转移,说明,每个项目需要的身体素质不同,运动员都要朝着正迁移的方向来进行训练。     

湖北省竞技体育发展中存在的问题及对策

对湖北省竞技体育的现状进行分析,指出目前发展中存在的诸多问题,并提出相应的对策：实施竞技体育规划战略;提升竞技人力资源水平;加强重点项目的建设、优化及布局;提高教练员的综合能力和素质等。     

影响我国优秀运动员商业价值的因素分析

对取得过辉煌运动成绩和良好商业收入的运动员的共同特征进行分析,结果表明：我国优秀运动员商业价值的影响因素包括运动员从事的体育项目、运动员的成绩与荣誉、运动员的运动寿命、运动员的外在形象、运动员的社会形象、体育管理制度、运动员的商业开发与管理等。     

Psychometric Properties of IRT Proficiency Estimates

Psychometric properties of item response theory proficiency estimates are considered in this paper. Proficiency estimators based on summed scores and pattern scores include non-Bayes maximum likelihood and test characteristic curve estimators and Bayesian estimators. The psychometric properties investigated include reliability, conditional standard errors of measurement, and score distributions. Four real-data examples include (a) effects of choice of estimator on score distributions and percent proficient, (b) effects of the prior distribution on score distributions and percent proficient, (c) effects of test length on score distributions and percent proficient, and (d) effects of proficiency estimator on growth-related statistics for a vertical scale. The examples illustrate that the choice of estimator influences score distributions and the assignment of examinee to proficiency levels. In particular, for the examples studied, the choice of Bayes versus non-Bayes estimators had a more serious practical effect than the choice of summed versus pattern scoring.