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   16659篇
  免费   431篇
管理学   2397篇
民族学   83篇
人才学   3篇
人口学   1678篇
丛书文集   96篇
教育普及   1篇
理论方法论   1660篇
现状及发展   1篇
综合类   180篇
社会学   8158篇
统计学   2833篇
  2023年   103篇
  2020年   244篇
  2019年   322篇
  2018年   345篇
  2017年   487篇
  2016年   418篇
  2015年   276篇
  2014年   379篇
  2013年   2968篇
  2012年   540篇
  2011年   450篇
  2010年   380篇
  2009年   386篇
  2008年   427篇
  2007年   422篇
  2006年   389篇
  2005年   430篇
  2004年   439篇
  2003年   379篇
  2002年   418篇
  2001年   418篇
  2000年   394篇
  1999年   382篇
  1998年   288篇
  1997年   262篇
  1996年   250篇
  1995年   257篇
  1994年   223篇
  1993年   248篇
  1992年   245篇
  1991年   238篇
  1990年   215篇
  1989年   238篇
  1988年   214篇
  1987年   183篇
  1986年   199篇
  1985年   226篇
  1984年   219篇
  1983年   207篇
  1982年   177篇
  1981年   152篇
  1980年   145篇
  1979年   178篇
  1978年   129篇
  1977年   129篇
  1976年   128篇
  1975年   122篇
  1974年   107篇
  1973年   101篇
  1971年   76篇
排序方式: 共有10000条查询结果,搜索用时 882 毫秒
991.
The Consistent System (CS) is an interactive computer system for researchers in the behavioral and policy sciences and in fields with similar requirements for data management and statistical analysis. The researcher is not expected to be a programmer. The system offers a wide range of facilities and permits the user to combine them in novel ways. In particular, tools for statistical analysis may be used in combination with a powerful relational subsystem for data base management. This paper gives an overview of the objectives, capabilities, status, and availability of the system.  相似文献   
992.
We explore the application of dynamic graphics to the exploratory analysis of spatial data. We introduce a number of new tools and illustrate their use with prototype software, developed at Trinity College, Dublin. These tools are used to examine local variability—anomalies—through plots of the data that display its marginal and multivariate distributions, through interactive smoothers, and through plots motivated by the spatial auto-covariance ideas implicit in the variogram. We regard these as alternative and linked views of the data. We conclude that the most important single view of the data is the Map View: All other views must be cross-referred to this, and the software must encourage this. The view can be enriched by overlaying on other pertinent spatial information. We draw attention to the possibilities of one-many linking, and to the use of line-objects to link pairs of data points. We draw attention to the parallels with work on Geographical Information Systems.  相似文献   
993.
In this paper, an alternative method for the comparison of two diagnostic systems based on receiver operating characteristic (ROC) curves is presented. ROC curve analysis is often used as a statistical tool for the evaluation of diagnostic systems. However, in general, the comparison of ROC curves is not straightforward, in particular, when they cross each other. A similar difficulty is also observed in the multi-objective optimization field where sets of solutions defining fronts must be compared with a multi-dimensional space. Thus, the proposed methodology is based on a procedure used to compare the performance of distinct multi-objective optimization algorithms. In general, methods based on the area under the ROC curves are not sensitive to the existence of crossing points between the curves. The new approach can deal with this situation and also allows the comparison of partial portions of ROC curves according to particular values of sensitivity and specificity of practical interest. Simulations results are presented. For illustration purposes, considering real data from newborns with very low birthweight, the new method was applied in order to discriminate the better index for evaluating the risk of death.  相似文献   
994.
Abstract

In March 2001 the Canadian National Site Licensing Project (CNSLP) enabled the University of Saskatchewan Library to add over seven hundred electronic titles to its journal collection. The CNSLP titles introduced a critical mass of electronic journals to library patrons, offering a complex and intriguing range of supplementary content and a transformation of the experience of reading scientific journals. This article reports on the plug-ins and add-ons required to access supplementary content in the CNSLP electronic journals and explores the implications of supplementary content for readers. Serials Review 2003; 29:103–116.  相似文献   
995.
k-POD: A Method for k-Means Clustering of Missing Data   总被引:1,自引:0,他引:1  
The k-means algorithm is often used in clustering applications but its usage requires a complete data matrix. Missing data, however, are common in many applications. Mainstream approaches to clustering missing data reduce the missing data problem to a complete data formulation through either deletion or imputation but these solutions may incur significant costs. Our k-POD method presents a simple extension of k-means clustering for missing data that works even when the missingness mechanism is unknown, when external information is unavailable, and when there is significant missingness in the data.

[Received November 2014. Revised August 2015.]  相似文献   
996.
The boxplot is an effective data-visualization tool useful in diverse applications and disciplines. Although more sophisticated graphical methods exist, the boxplot remains relevant due to its simplicity, interpretability, and usefulness, even in the age of big data. This article highlights the origins and developments of the boxplot that is now widely viewed as an industry standard as well as its inherent limitations when dealing with data from skewed distributions, particularly when detecting outliers. The proposed Ratio-Skewed boxplot is shown to be practical and suitable for outlier labeling across several parametric distributions.  相似文献   
997.
998.
Abstract

Reports on the Ohio Valley Group of Technical Services Librarians (OVGTSL) Annual Conference, the April 2004 New England Technical Services Librarians (NETSL) Conference, the 2004 Acquisitions Institute at Timberline Lodge, and the 2004 Conference of the North American Serials Interest Group (NASIG).

Reports are from four conferences held in various parts of the United States and cover a wide range of topics. The Ohio Valley Group of Technical Services Librarians program emphasized the relationship between technical and public services. Education, both formal and continuing, was the theme for the New England Technical Services Librarians. Timberline Lodge hosted another Acquisitions Institute featuring sessions on new discoveries. The report on the 2004 North American Serials Group Annual Conference allows Conference Student Grant Award winner Chris Brady to include some personal reflections along with summaries of the sessions he attended.  相似文献   
999.
1000.
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