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   984篇
  免费   17篇
  国内免费   7篇
管理学   100篇
民族学   8篇
人口学   16篇
丛书文集   53篇
理论方法论   22篇
综合类   369篇
社会学   69篇
统计学   371篇
  2024年   2篇
  2023年   11篇
  2022年   14篇
  2021年   9篇
  2020年   21篇
  2019年   22篇
  2018年   37篇
  2017年   53篇
  2016年   25篇
  2015年   27篇
  2014年   36篇
  2013年   175篇
  2012年   73篇
  2011年   50篇
  2010年   43篇
  2009年   37篇
  2008年   42篇
  2007年   43篇
  2006年   35篇
  2005年   44篇
  2004年   26篇
  2003年   41篇
  2002年   34篇
  2001年   28篇
  2000年   17篇
  1999年   10篇
  1998年   11篇
  1997年   9篇
  1996年   5篇
  1995年   3篇
  1994年   4篇
  1993年   7篇
  1992年   1篇
  1991年   2篇
  1990年   5篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1981年   1篇
排序方式: 共有1008条查询结果,搜索用时 15 毫秒
121.
Many sampling problems from multiple populations can be considered under the semiparametric framework of the biased, or weighted, sampling model. Included under this framework is logistic regression under case–control sampling. For any model, atypical observations can greatly influence the maximum likelihood estimate of the parameters. Several robust alternatives have been proposed for the special case of logistic regression. However, some current techniques can exhibit poor behavior in many common situations. In this paper a new family of procedures are constructed to estimate the parameters in the semiparametric biased sampling model. The procedures incorporate a minimum distance approach, but are instead based on characteristic functions. The estimators can also be represented as the minimizers of quadratic forms in simple residuals, thus yielding straightforward computation. For the case of logistic regression, the resulting estimators are shown to be competitive with the existing robust approaches in terms of both robustness and efficiency, while maintaining affine equivariance. The approach is developed under the case–control sampling scheme, yet is shown to be applicable under prospective sampling logistic regression as well.  相似文献   
122.
Although sustainability recently became a key factor in social science, little progress has been made toward improving the measurement of sustainability performance. This paper proposes composite corporate sustainability performance indicators using a meta-frontier generalized directional distance function. This advanced approach can measure the efficiency of corporate social responsibility activities by benchmarking, while simultaneously considering industrial heterogeneities, using the meta-frontier approach. First, we propose the concept of a meta-frontier generalized directional distance function. Second, several standardized composite indicators related to corporate sustainability performance are developed. The meta-frontier directional distance function is estimated by solving a series of data envelopment analysis models. Chinese state-owned listed enterprises are then empirically examined using the proposed model. We find significant group heterogeneities in terms of corporate sustainability performance. We also derive some policy implications using the empirical results.  相似文献   
123.
In this paper we propose a new method for studying local and global clustering in networks employing random walk pairs. The method is intuitive and directly generalizes standard local and global clustering coefficients to weighted networks and networks containing nodes of multiple types. In the case of two-mode networks the values obtained for commonly considered social networks are in sharp contrast to those obtained, for instance, by the method of Opsahl (2013), and provide a different viewpoint for clustering. The approach is also applicable in questions related to the general study of segregation and homophily. Applications to existent data sets are considered.  相似文献   
124.
远程培训作为教师培训的主要途径之一,具有规模大、成本低、跨时空等特点,对提高教师培训质量、促进教师专业发展具有重要作用。通过对我国教师远程培训研究文献进行可视化分析,绘制出热点知识图谱,从中可以发现:教师远程培训研究发文量在一段时间内呈上升趋势;研究热点主要集中在现状与策略、需求与服务、课程与模式、技术与平台等领域;研究方向逐渐从重视经验介绍、技术讲解、平台展示的“技术化”价值取向,转向重视培训教师的素养和参训教师的需求、落实教师专业发展措施的“智慧化”价值取向。新时代下,我国教师远程培训的发展势如破竹,在教师教育振兴进程中发挥着越来越重要的作用。相关研究显示,教师远程培训在对象拓展、课程设置、模式优化、评价运用、平台开发等方面也呈现出“智慧化”趋向。向“智慧化”教师远程培训的广度、深度和效度发力,需要着重做好几个方面的工作:开展培训对象的系统化探索、加强培训课程的立体化开发、重视培训模式的混合化构建、注重培训评价的大数据分析以及加强培训平台的智能化研发。  相似文献   
125.
SUMMARY

The Campus Alberta Applied Psychology: Counselling Initiative is a collaboration between three universities in western Canada to offer a predominantly Web-based Master of Counselling program. This paper describes the basic structure of the program, the Web-based delivery system, communication tools employed, and the philosophical, pedagogical, programmatic, and administrative principles and concepts foundation to the development and implementation. Development of curricular content and learning processes have been driven by explicit examination of learner needs, a program-level competency matrix reflective of professional practice standards in the discipline of psychology, and deliberate and continuous formative evaluation and learner engagement in the process.  相似文献   
126.
ABSTRACT

A usability test of a distance continuing education website for human service professionals is discussed. The website's purpose was to help meet the continuing education needs of human service professionals in a largely rural Midwestern state. The purpose of the usability evaluation was to assess the website's ease of use, efficiency, and user satisfaction in a representative sample of human service professionals. Users completed eleven basic search tasks with the site and report their impressions of the information presented. In addition, performance data including success, time on task, and efficiency were gathered. Implications of user satisfaction and performance data highlight the importance of stakeholder's involvement in the early stages of website design.  相似文献   
127.
Geographical location as a “natural” attribute of news has always been a source of news manipulation. This research investigates how different community newspapers select, interpret, and package events originating in places of varying distances. Contextualized in Hong Kong, three media frames (authority, conflict, and attribution) are closely examined and theoretically connected to three types of newspapers (mass appeal, elite, and pro-establishment) across four locales (local, mainland China, Asian, and international). To test the hypotheses, a large-scale content analysis of 14 daily newspapers in Hong Kong was conducted. On the whole, findings supported the three hypotheses, showing that local news was systematically differentiated from non-local news in terms of the frequency of political authorities cited, presence of diversified opinions, and the likelihood of either individuals or institutions being blamed for social wrongs. Considerable variations were detected across different types of newspapers as well. Theoretical and social implications of the empirical findings are discussed.  相似文献   
128.
We reveal that the minimum Anderson–Darling (MAD) estimator is a variant of the maximum likelihood method. Furthermore, it is shown that the MAD estimator offers excellent opportunities for parameter estimation if there is no explicit formulation for the distribution model. The computation time for the MAD estimator with approximated cumulative distribution function is much shorter than that of the classical maximum likelihood method with approximated probability density function. Additionally, we research the performance of the MAD estimator for the generalized Pareto distribution and demonstrate a further advantage of the MAD estimator with an issue of seismic hazard analysis.  相似文献   
129.
An outlier is defined as an observation that is significantly different from the others in its dataset. In high-dimensional regression analysis, datasets often contain a portion of outliers. It is important to identify and eliminate the outliers for fitting a model to a dataset. In this paper, a novel outlier detection method is proposed for high-dimensional regression problems. The leave-one-out idea is utilized to construct a novel outlier detection measure based on distance correlation, and then an outlier detection procedure is proposed. The proposed method enjoys several advantages. First, the outlier detection measure can be simply calculated, and the detection procedure works efficiently even for high-dimensional regression data. Moreover, it can deal with a general regression, which does not require specification of a linear regression model. Finally, simulation studies show that the proposed method behaves well for detecting outliers in high-dimensional regression model and performs better than some other competing methods.  相似文献   
130.
For many applications involving compositional data, it is necessary to establish a valid measure of distance, yet when essential zeros are present traditional distance measures are problematic. In quantitative fatty acid signature analysis (QFASA), compositional diet estimates are produced that often contain many zeros. In order to test for a difference in diet between two populations of predators using the QFASA diet estimates, a legitimate measure of distance for use in the test statistic is necessary. Since ecologists using QFASA must first select the potential species of prey in the predator's diet, the chosen measure of distance should be such that the distance between samples does not decrease as the number of species considered increases, a property known in general as subcompositional coherence. In this paper we compare three measures of distance for compositional data capable of handling zeros, but not satisfying some of the well-accepted principles of compositional data analysis. For compositional diet estimates, the most relevant of these is the property of subcompositionally coherence and we show that this property may be approximately satisfied. Based on the results of a simulation study and an application to real-life QFASA diet estimates of grey seals, we recommend the chi-square measure of distance.  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