浅谈同余与不变子群的关系

介绍了等价关系与子群的关系,并由此推导出同余关系与不变子群的等价定理,从而进一步加深对等价关系、同余关系、子群、不变子群以及商群的理解.     

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

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.     

关于强duo模的推广

本文给出了强duo模的一个推广——极大强duo模,研究了极大强duo模的一些刻画及性质,并且证明了在半单模的条件下,极大强duo模与强duo模是等价的.     

Two-Year Impacts of a Comprehensive Family Financial Rewards Program on Children's Academic Outcomes: Moderation by Likelihood of Earning Rewards

Abstract

This article examines the extent to which impacts of a conditional cash transfer (CCT) program on children's academic outcomes vary by key characteristics associated with families’ propensity to earn the rewards offered by the program. We utilize an experimental study of Opportunity NYC-Family Rewards, a comprehensive CCT program in New York City in which low-income families were offered rewards for outcomes in health, education, and work. Building from a technique in propensity score research but used here to assess subgroup impacts in experimental studies, we use multiple baseline characteristics to predict the amount of rewards earned as a means to identify theoretically important, multivariate-defined groups of children for whom program effects might be more concentrated. Fourth-grade children in families with higher likelihood to earn rewards experienced more positive impacts of the program on academic outcomes. By contrast, no program impacts were found among 7th- or 9th-graders whose families were most likely to earn rewards. Differences across age groups are discussed in terms of their different developmental periods and the differing way the children experienced the intervention.     

Riesz乘积空间的有关性质

设 { Ei∶i∈I}是一族 Riesz空间且 E= i∈ I　Ei 是 Riesz乘积空间 .关于 Riesz子空间、理想、带、(主 )投影性质、正算子和 Riesz同态 ,指出 E与每一个因子空间 Ei 之间的一些关系 .当 E=C(X)和 Ei=C(Xi) (X和 Xi 为实紧空间 )时 ,还得到 E上 Riesz同态和极大理想的表示形式     

论短跑训练中的最大力量训练与快速力量训练

在短跑的力量训练中目前更多采用快速力量训练法,对最大力量训练法,由于存在认识上的差异,训练中选用较少。最大力量训练法是发展绝对力量和提高肌肉协调力最直接有效的方法。对短跑运动员来说合理运用最大力量训练法,在发展最大力量基础上进而发展快速力量和肌肉协调性,对提高短跑能力和运动成绩是一种经济实用的方法。     

所有极大子群皆交换或正规的有限群

刻画了所有极大子群皆交换或正规的有限群的结构.     

求解奇异线性方程组的一类推广的Cramer法则

任意给定方阵A,首先给出了A的群逆、Dazin逆的行列式表示,借此导出了求一类约束线性方程组的解的行列式公式,并应用文献[8]的结果,得到了求不相容线性方程组极小范数最小二乘解的行列式公式.当方程组为非奇异线性方程组时,所得行列式公式均可化为经典的Cramer法则,从而将Cramer法则在奇异线性方程组领域做了新的形式的推广.     

修正α—亏量及满亏量问题

本文讨论超亚纯函数的修正α-亏量,得到亏量关系:并解决了一个满亏量问题:若则f(z)的级是整数。     

关于运动解剖学的几个基本概念

力和力矩是两个不同的概念，应加以区别使用；肌肉工作时定点的确定要以躯体支撑点为基本参考点，肌肉做静力性工作时是双固定状态；肌肉拉力线应用射线来标示；要根据具体情况作具体分析，不能简单地以动点向定点的连线标示，影响肌肉最大力量的解剖学因素是该肌肉内可能形成的最大横桥数目和肌肉收缩时的初长度，神经调节、肌拉力角、肌收缩矩均不是影响肌肉最大比力的解剖学因素．