Perfect matchings in paired domination vertex critical graphs

A vertex subset S of a graph G=(V,E) is a paired dominating set if every vertex of G is adjacent to some vertex in S and the subgraph induced by S contains a perfect matching. The paired domination number of G, denoted by γ _pr (G), is the minimum cardinality of a paired dominating set of?G. A?graph with no isolated vertex is called paired domination vertex critical, or briefly γ _pr -critical, if for any vertex v of G that is not adjacent to any vertex of degree one, γ _pr (G?v)<γ _pr (G). A?γ _pr -critical graph G is said to be k-γ _pr -critical if γ _pr (G)=k. In this paper, we firstly show that every 4-γ _pr -critical graph of even order has a perfect matching if it is K _1,5-free and every 4-γ _pr -critical graph of odd order is factor-critical if it is K _1,5-free. Secondly, we show that every 6-γ _pr -critical graph of even order has a perfect matching if it is K _1,4-free.     

论军训中开设定向越野训练的价值

开展定向越野训练具有诸多重要军训价值,能使学生在掌握用图能力,提高身体素质、越野技能和心理素质。野外适应能力等各方面均得到提高。通过定向越野训练,学生在定向越野中形成的各种优良素质均可迁移到学习和生活中,产生顺向迁移效应,对学生学习和将来工作产生积极的影响。     

流动人口的社会保障：一个文献综述

从流动人口自身的特点出发,对流动人口社会保障现状、影响因素及其发展路径等方面的研究文献进行了综述,并总结了流动人口社会保障理论需要深入研究的方向与领域。     

Remarriage,Delayed Marriage,and Black/White Intermarriage, 1968–1995

How have changes in marriage order and marriage timing affected 1968–1995 trends in United States Black/White intermarriage? Researchers usually follow a one-sex perspective on the effects of timing and marriage order on marital selection, arguing that delayed marriages and remarriages will be more heterogamous than early or first marriages. This paper shows that a one-sex perspective is oversimplified and that assortative marriage with respect to race depends on the interaction of both husband’s and wife’s characteristics. Marriages that match with respect to age or marriage order tend to also match with respect to race. First marriages and remarriages for both partners are more likely to be same-race marriages. Marriages that are intermarriages with respect to marriage order are more likely to also be intermarriages with respect to race. Marriages that are usual age combinations (husband and wife similar in age or husband slightly older) are also usual race combinations (husband and wife same race). Marriages that are unusual age combinations are more likely to be racial intermarriages. This paper also shows that trends in remarriage patterns do not account for the increasing trend in racial intermarriage and that trends in marriage timing have actually slowed increases in racial intermarriage.     

创建和谐家庭,营造和谐社会

和谐家庭,对个人和社会的健康发展具有重要作用。改革开放以来,由于我国经济结构的转型和中西文化的交流、碰撞和融合,我国的家庭观念、家庭结构、家庭功能等发生了重大变化,家庭问题也日益突出,对家庭的健康发展和社会的和谐产生了重要影响,因而认真对待我国家庭存在的问题,重塑现代人和谐幸福的家庭生活是非常必要的。     

教育公平:走向作为正义制度保障的法律实践

当教育公平已经成为大众对构楚和谐社会的首要利益诉求时,必须将教育公平由一种珍贵的理念具体化为一种能够作为正义制度保障的法律实践,教育公平的实现机制只有纳入法治的轨道才能够获得坚实的基础,可以从公法、私法的维庹,在教育公平的利益表达、分配、平衡和救济等几方面进行教育公平法律保障机制的具体建构.     

SiZer analysis for the comparison of time series

SiZer (SIgnificant ZERo crossing of the derivatives) is a scale-space visualization tool for statistical inferences. In this paper we introduce a graphical device, which is based on SiZer, for the test of the equality of the mean of two time series. The estimation of the quantile in a confidence interval is theoretically justified by advanced distribution theory. The extension of the proposed method to the comparison of more than two time series is also done using residual analysis. A broad numerical study is conducted to demonstrate the sample performance of the proposed tool. In addition, asymptotic properties of SiZer for the comparison of two time series are investigated.     

管理者性别刻板印象影响研究

"一想到管理者就想到男性"的管理者性别刻板印象具有普遍存在的特征,这种性别思维定式会对组织中女性管理者的晋升、组织自身的经济和社会效益产生重要影响,而由此引发的扩散效应甚至会影响到整个社会的公平与效率,对其影响的充分认识是发现问题和解决问题的基础和前提.     

Effects of ability mixing in high school on adulthood earnings: quasiexperimental evidence from South Korea

We estimate impacts of ability mixing compared to ability grouping in high school education on students’ adulthood earnings. To overcome endogeneity and selection problems that plagued the previous studies, we exploit a policy experiment in South Korea in the 1970s, which changed the education regime of general high schools from grouping to mixing in major cities. We find that the mixing treatment has a positive but statistically insignificant effect on average adulthood earnings. We also find that while mixing has positive effects on low ability students’ adulthood earnings, it has smaller positive or even negative effects on higher ability students.      

Testing for serial correlation in linear model with validation data

In this paper, we investigate the testing for serial correlation in a linear model with validation data, then we apply the empirical likelihood method to construct the test statistic and derive the asymptotic distribution of the test statistic under null hypothesis. Simulation results show that our method performs well both in size and power with finite same size.