Maximal Criterion Validity and Scale Criterion Validity: A Latent Variable Modeling Approach for Examining Their Difference     

Tenko Raykov  Siegfried Gabler  Dimiter M. Dimitrov 《Structural equation modeling》2016,23(4):544-554

This article studies the difference between the criterion validity coefficient of the widely used overall scale score for a unidimensional multicomponent measuring instrument and the maximal criterion validity coefficient that is achievable with a linear combination of its components. A necessary and sufficient condition of their identity is presented in the case of measurement errors being uncorrelated among themselves and with a used criterion. An upper bound of the difference in these validity coefficients is provided, indicating that it cannot exceed the discrepancy between the maximal reliability and composite reliability indexes. A readily applicable latent variable modeling procedure is discussed that can be used for point and interval estimation of the difference between the maximal and scale criterion validity coefficients. The outlined method is illustrated with a numerical example.  相似文献   

BP网络的主控式误差调整学习算法     

孙巧萍 《台州学院学报》2002,24(6):22-23

提出一种BP神经网络的主控式误差调整学习算法,该算法根据网络输出端的误差变化趋势主动控制输出层的误差调整,进而由调整误差的主动调节控制网络权值和阈值的学习。计算机模拟结果表明,这种学习方法具有能稳定收敛、收敛速度快、适用范围宽、泛化能力强等特点,从而在一定程度上克服了传统BP算法的局限性,实现较有效的学习。  相似文献   

谈地方新建本科院校科研年报统计工作     

高全忠  李少茹 《临沂师范学院学报》2003,25(1):65-67

在地方新建本科院校科研年报统计工作中，把握好新建本科院校的特点是搞好科研年报统计的基础；依据有关文件精神，科研人员与有关人员通力合作是搞好统计年报工作的关键；提高科研统计工作者的素质，抓住年报统计过程中的重要环节，是年报统计质量的保征。  相似文献   

Allocating Sample Sizes to Reduce Budget for Fixed-Effect 2×2 Heterogeneous Analysis of Variance     

Wei-Ming Luh  Jiin-Huarng Guo 《Journal of Experimental Education》2016,84(1):197-211

This article discusses the sample size requirements for the interaction, row, and column effects, respectively, by forming a linear contrast for a 2×2 factorial design for fixed-effects heterogeneous analysis of variance. The proposed method uses the Welch t test and its corresponding degrees of freedom to calculate the final sample size in a 2-step procedure. The simulation results show that the proposed sample size allocation ratio can minimize the sampling cost, while at the same time the designated power is achieved. The article concludes with a discussion to reiterate the importance of sample size planning, especially for testing the iteration effect.  相似文献   

强酸-弱酸混合体系中准确滴定强酸的研究     

马荔  张卫  陈虹锦  梁竹梅  谢少艾  李梅 《实验室研究与探索》2011,30(2):5-8

为准确滴定出强酸-弱酸混合体系中所含强酸的量,需考虑在不同的准确度要求条件下,混合酸体系中弱酸的浓度范围要求。基于混合酸滴定过程终点误差的2个来源分析,提出了混合酸体系中终点误差(TE)计算的新方法。在指定的终点误差要求和强酸的浓度范围条件下,计算了HCl-HAc、HCl-六次甲基四胺盐两种混合酸体系中HAc、六次甲基四胺盐浓度范围要求,随着各酸碱指示剂变色点pH值的增大,两弱酸浓度的上限要求逐渐减小。在|TE|=1%条件下,当HAc、六次甲基四胺盐浓度分别低于1.18和0.135 mmol/dm3时,可采用任意酸性指示剂准确滴定0.1 mol/dm3浓度范围的HCl含量;而当两弱酸浓度分别低于10.6和10.5 mmol/dm3时,准确滴定出混合酸体系中1.0 mol/dm3的HCl含量亦可采用任意酸性指示剂。  相似文献   

聋生对复句的掌握状况调查研究     

刘卿 《中国特殊教育》2011,(8)

本文对聋人学生的复句应用情况进行了调查,通过对就读于大专院校的聋生写作的1568个复句进行统计和分析,探讨聋生复句应用过程中各种错误类型产生的原因,揭示聋生习得汉语复句的特点,指出聋生掌握复句的重点与难点,并提出相应的教学策略,以期为聋生复句教学提供参考和借鉴。  相似文献   

对纳达尔2014年法网比赛中的技术统计分析     

沈煜 《体育科技文献通报》2015,(1)

本文运用文献法、录像观察法、数理统计法对纳达尔在2014年法网单打比赛中的技战术进行统计分析,结果表明：纳达尔在发球方面具有自己的特点,保持着高效发球得分率;在接发球方面有着快速的判断、稳定的心理素质,接发球成功率很高,说明纳达尔的接发球进攻能力强,高效的破发成功率也说明纳达尔把握机会的能力很强;在比赛时以底线作为主要阵地,发挥自身优势,发挥自己击球力量大和角度刁钻,旋转强和落点准的特点;网前进攻意识不强,得分相对较少。  相似文献   

Correlation between maximum in-shoe plantar pressures and clubhead speed in amateur golfers     

Todd Colin Pataky 《Journal of sports sciences》2015,33(2):192-197

Disagreements exist in the literature regarding the manner in which weight should be dynamically shared during the golf swing, both within-feet and between the back- and target-foot, to generate maximal clubhead speed. The purpose of this study was to determine whether preferential foot-loading locations underlie weight sharing by examining the correlation between clubhead speed and maximum plantar pressure (PP) distributions. Thirty-two amateur golfers with handicap indexes ranging from 2.7 to 25 performed 10 driver swings on artificial turf following a warm-up. PP distributions were recorded at 100 Hz, and clubhead speed was recorded using a ball-tracking Doppler radar system. Maximum PPs were extracted from a 2-s window approximately centred on ball contact and were regressed against clubhead speed. Significance was assessed over the entire foot surface using statistical parametric mapping (SPM), a spatially continuous technique. SPM revealed, at relatively high anatomical resolution, significant positive correlations between clubhead speed and PPs in the lateral target-foot (P < 0.05). This suggests that not only weight transfer but also weight-transfer location may be an important determinant of clubhead speed in amateur golfers.  相似文献   

基于贝叶斯网络的航空维修差错致因分析     

白乃贵 《滨州学院学报》2015,(2):26-31

近年来事故分析显示,维修差错导致的航空事故在总事故中占较大的比重,精确分析维修差错的诱发因素有助于提高维修质量管理。在分析维修差错模式及诱发因素的基础上,基于贝叶斯网络建立了以维修任务为叶节点的差错致因分析网络,通过概率重要度分析和关键重要度分析对维修差错致因进行了定性、定量评估。通过对某航空事故的分析表明该方法切实可行。  相似文献   

基于ADAMS的双边驱动玻璃切割平台动态误差仿真分析     

张海涛  陈丰  许芹 《安徽科技学院学报》2015,(1):62-65

双边驱动玻璃切割平台驱动电机运动不同步时,平台运动部件会产生偏转振动,从而带来刀具运动及定位的动态误差,影响玻璃制件的加工质量和加工精度。通过刚柔耦合模型实现了双边驱动玻璃切割平台的仿真建模,利用动力学仿真分析软件ADAMS对非同步条件驱动下运动部件的动态误差进行了仿真分析,为双边驱动玻璃切割平台的设计和控制提供了理论依据。  相似文献