首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   503篇
  免费   15篇
  国内免费   2篇
管理学   28篇
人口学   12篇
丛书文集   14篇
理论方法论   25篇
综合类   92篇
社会学   30篇
统计学   319篇
  2023年   8篇
  2022年   8篇
  2021年   10篇
  2020年   16篇
  2019年   20篇
  2018年   23篇
  2017年   34篇
  2016年   29篇
  2015年   16篇
  2014年   22篇
  2013年   81篇
  2012年   47篇
  2011年   28篇
  2010年   17篇
  2009年   13篇
  2008年   11篇
  2007年   22篇
  2006年   14篇
  2005年   16篇
  2004年   13篇
  2003年   8篇
  2002年   18篇
  2001年   10篇
  2000年   6篇
  1999年   2篇
  1998年   7篇
  1997年   9篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1992年   2篇
  1990年   1篇
  1985年   1篇
  1975年   1篇
排序方式: 共有520条查询结果,搜索用时 15 毫秒
81.
高等学校学生成绩分析方法的研究   总被引:1,自引:0,他引:1  
学生的考试成绩一直是直接评价学生学业的重要标准,也是评价学生综合素质的一个主要指标。综合分析高等学校学生的学习成绩,掌握学生的学习动态,对培养学生成才至关重要。应用软件Microsoft Office Excel研究了综合分析普通高等学校学生成绩的方式,并将分析的结果应用到学生的培养。实践证明,该学习成绩的分析方法可以有效地提高学生的培养成效,在实际应用中可以作为培养学生成才的重要依据,为高等学校培养学生成才提供重要的分析工具。  相似文献   
82.
结合金融系统广泛采用的FICO个人信用评估思想,提出了大学生诚信评价的加减分模型,构建了大学生诚信评估系统(CESS)指标体系及其数据仓库,实现了诚信数据校内整合与共享,并分别以ASP和VB.NET为工具开发了Web及C/S两种风格的CESS系统,介绍了系统结构与功能设计,讨论了包括直接利用Analysis Services多维分析工具实现的丰富的信用查询与统计方式,通过实际数据测试表明,CESS系统能够较好地满足高校需要.  相似文献   
83.
个人收入分配制度是人民公社体制下重要的制度安排.本文从公社个人收入分配的构成和分配依据,以及与收入分配密切相关的公社劳动管理制度和工分制几个方面,说明了人民公社体制调整后到改革前的个人收入分配的实况,由此从一个侧面证明了以大包干为特征的分配制度创新,并最终取代公社平均主义分配制度所具有的历史必然性.  相似文献   
84.
Relatively few studies examine the relationship between racial residential segregation and educational or cognitive outcomes. Using data from the National Longitudinal Study of Adolescent Health and the institutional resources model of neighborhood effects, I investigate one account of how macrostructural arrangements between race, neighborhood segregation, and school quality interact to produce inequalities in test scores. Consistent with the institutional resources model, results suggest that school quality varies across neighborhoods based, in part, on their degree of racial concentration. Indeed, school quality and other school characteristics mediate the relationship between racial concentration and verbal skills, particularly among black males. These findings have implications not only for inequalities in cognitive skills among blacks across residential space, but also between blacks and whites given high levels of residential segregation in the United States. In sum, findings illustrate yet another way in which residential segregation contributes to, and not merely reflects, racial inequalities.  相似文献   
85.
ABSTRACT

Correlated bilateral data arise from stratified studies involving paired body organs in a subject. When it is desirable to conduct inference on the scale of risk difference, one needs first to assess the assumption of homogeneity in risk differences across strata. For testing homogeneity of risk differences, we herein propose eight methods derived respectively from weighted-least-squares (WLS), the Mantel-Haenszel (MH) estimator, the WLS method in combination with inverse hyperbolic tangent transformation, and the test statistics based on their log-transformation, the modified Score test statistic and Likelihood ratio test statistic. Simulation results showed that four of the tests perform well in general, with the tests based on the WLS method and inverse hyperbolic tangent transformation always performing satisfactorily even under small sample size designs. The methods are illustrated with a dataset.  相似文献   
86.
ABSTRACT

The optimal learner for prediction modeling varies depending on the underlying data-generating distribution. Super Learner (SL) is a generic ensemble learning algorithm that uses cross-validation to select among a ‘library’ of candidate prediction models. While SL has been widely studied in a number of settings, it has not been thoroughly evaluated in large electronic healthcare databases that are common in pharmacoepidemiology and comparative effectiveness research. In this study, we applied and evaluated the performance of SL in its ability to predict the propensity score (PS), the conditional probability of treatment assignment given baseline covariates, using three electronic healthcare databases. We considered a library of algorithms that consisted of both nonparametric and parametric models. We also proposed a novel strategy for prediction modeling that combines SL with the high-dimensional propensity score (hdPS) variable selection algorithm. Predictive performance was assessed using three metrics: the negative log-likelihood, area under the curve (AUC), and time complexity. Results showed that the best individual algorithm, in terms of predictive performance, varied across datasets. The SL was able to adapt to the given dataset and optimize predictive performance relative to any individual learner. Combining the SL with the hdPS was the most consistent prediction method and may be promising for PS estimation and prediction modeling in electronic healthcare databases.  相似文献   
87.
This paper considers a family of penalized likelihood score tests for group variation. The tests can be indexed by a measure of degrees of freedom. At one extreme, with degrees of freedom one less than the number of groups, is the usual score test for a fixed effects alternative using indicator variables for the groups, while at the other extreme, in the limit as the degrees of freedom 0, is a test closely related to a score test based on a random effects alternative. Asymptotic power comparisons are made for the tests in the family. As would be expected, different members of the family are more efficient for different alternatives. Generally the tests with smaller degrees of freedom appear to have better power than the standard test for alternatives focusing on differences among the larger groups, and lower power for alternatives focusing on differences among the smaller groups. Simulations indicate the asymptotic approximation to the distribution performs better for the tests with small degrees of freedom.  相似文献   
88.
Borrowing data from external control has been an appealing strategy for evidence synthesis when conducting randomized controlled trials (RCTs). Often named hybrid control trials, they leverage existing control data from clinical trials or potentially real-world data (RWD), enable trial designs to allocate more patients to the novel intervention arm, and improve the efficiency or lower the cost of the primary RCT. Several methods have been established and developed to borrow external control data, among which the propensity score methods and Bayesian dynamic borrowing framework play essential roles. Noticing the unique strengths of propensity score methods and Bayesian hierarchical models, we utilize both methods in a complementary manner to analyze hybrid control studies. In this article, we review methods including covariate adjustments, propensity score matching and weighting in combination with dynamic borrowing and compare the performance of these methods through comprehensive simulations. Different degrees of covariate imbalance and confounding are examined. Our findings suggested that the conventional covariate adjustment in combination with the Bayesian commensurate prior model provides the highest power with good type I error control under the investigated settings. It has desired performance especially under scenarios of different degrees of confounding. To estimate efficacy signals in the exploratory setting, the covariate adjustment method in combination with the Bayesian commensurate prior is recommended.  相似文献   
89.
When treatment cannot be manipulated, propensity score analysis provides a useful way to making causal claims under the assumption of no unobserved confounders. However, it is still rarely utilised in leadership and applied psychology research. The purpose of this paper is threefold. First, it explains and discusses the application and key assumptions of the method with a particular focus on propensity score weighting. This approach is readily implementable since a weighted regression is available in most statistical software. Moreover, the approach can offer a “double robust” protection against misspecification of either the propensity score or the outcome model by including confounding variables in both models. A second aim is to discuss how propensity score analysis (and propensity score weighting, specifically) has been conducted in recent management studies and examine future challenges. Finally, we present an advanced application of the approach to illustrate how it can be employed to estimate the causal impact of leadership succession on performance using data from Italian football. The case also exemplifies how to extend the standard single treatment analysis to estimate the separate impact of different managerial characteristic changes between the old and the new manager.  相似文献   
90.
The estimation of population parameters of the continuous common factor model from categorical observed variables is meanwhile regularly performed. It is shown that the formula for the calculation of the determinacy of the regression factor score predictor from the estimated model parameters has to be adapted under these conditions. A method for the calculation of this determinacy from the model parameters of the continuous population factor model based on categorical variables is proposed and evaluated by means of simulated population data. It turns out that using the uncorrected formula can lead to serious overestimation of determinacy for categorical variables.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号