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   3505篇
  免费   73篇
  国内免费   19篇
管理学   196篇
劳动科学   1篇
民族学   10篇
人口学   34篇
丛书文集   97篇
理论方法论   36篇
综合类   692篇
社会学   80篇
统计学   2451篇
  2024年   2篇
  2023年   21篇
  2022年   25篇
  2021年   28篇
  2020年   64篇
  2019年   103篇
  2018年   126篇
  2017年   186篇
  2016年   80篇
  2015年   82篇
  2014年   113篇
  2013年   1074篇
  2012年   266篇
  2011年   120篇
  2010年   124篇
  2009年   94篇
  2008年   99篇
  2007年   110篇
  2006年   88篇
  2005年   101篇
  2004年   77篇
  2003年   82篇
  2002年   69篇
  2001年   79篇
  2000年   58篇
  1999年   47篇
  1998年   49篇
  1997年   27篇
  1996年   21篇
  1995年   19篇
  1994年   14篇
  1993年   22篇
  1992年   19篇
  1991年   10篇
  1990年   20篇
  1989年   13篇
  1988年   11篇
  1987年   7篇
  1986年   6篇
  1985年   4篇
  1984年   7篇
  1983年   6篇
  1982年   4篇
  1981年   1篇
  1980年   6篇
  1979年   4篇
  1978年   6篇
  1977年   1篇
  1976年   2篇
排序方式: 共有3597条查询结果,搜索用时 31 毫秒
871.
谈几类中值定理辅助函数的构造方法   总被引:2,自引:0,他引:2  
给出三类中值定理辅助函数的构造方法.  相似文献   
872.
873.
Abstract. This paper is concerned with exact control of the false discovery rate (FDR) for step‐up‐down (SUD) tests related to the asymptotically optimal rejection curve (AORC). Since the system of equations and/or constraints for critical values and FDRs is numerically extremely sensitive, existence and computation of valid solutions is a challenging problem. We derive explicit formulas for upper bounds of the FDR and show that under a well‐known monotonicity condition, control of the FDR by a step‐up procedure results in control of the FDR by a corresponding SUD procedure. Various methods for adjusting the AORC to achieve finite FDR control are investigated. Moreover, we introduce alternative FDR bounding curves and study their connection to rejection curves as well as the existence of critical values for exact FDR control with respect to the underlying FDR bounding curve. Finally, we propose an iterative method for the computation of critical values.  相似文献   
874.
This paper proposes two classes of almost unbiased ratio and product estimators, in the case of interpenetrating subsample designs, which include the estimators considered by earlier authors. Several other almost unbiased ratio and product estimatbrs are given whlch are particular members of the proposed classes of estimators. Optimum estimators are also identified in these classes.  相似文献   
875.
During the past 15 years, the ordinary least squares estimator and the corresponding pivotal statistic have been widely used for testing the unit-root hypothesis in autoregressive processes. Recently, several new criteria, based on maximum likelihood estimators and weighted symmetric estimators, have been proposed. In this article, we describe several different test criteria. Results from a Monte Carlo study that compares the power of the different criteria indicate that the new tests are more powerful against the stationary alternative. Of the procedures studied, the weighted symmetric estimator and the unconditional maximum likelihood estimator provide the most powerful tests against the stationary alternative. As an illustration, the weekly series of one-month treasury-bill rates is analyzed.  相似文献   
876.
The asymptotic structure of a vector of weighted sums of signs of residuals, in the general linear model, is studied. The vector can be used as a basis for outlier-detection tests, or alternatively, setting the vector to zero and solving for the parameter yields a class of robust estimators which are analogues of the sample median. Asymptotic results for both estimates and tests are obtained. The question of optimal weights is investigated, and the optimal estimators in the case of simple linear regression are found to coincide with estimators introduced by Adichie.  相似文献   
877.
The estimation of a regression function g using linear splines is considered. The integrated mean square error is minimized using choice of estimator, allocation of observations and displacement of knots.  相似文献   
878.
Comparisons of multivariate normal populations are made using a mul-tivariate approach (instead of reducing the problem to a univariate one). A rather negative finding is that, for comparisons with the ‘best’ of each variate, repeated univariate comparisons appear to be almost as efficient as multivariate comparisons, at least for the bivariate case and, under certain circumstances, for higher dimensional cases. Investigations are done on comparisons with the ‘MAX-best’ population (that one having the largest maximum of the marginal means), the ‘MIN-best’ (having the largest minimum) and the ‘O-best’ (being closest to largest in all marginal means). Detailed results are given for the bivariate normal with extensions indicated for the multivariate.  相似文献   
879.
针对线间距的求解问题,介绍了一种综合利用计算机技术及其绘图功能求得线间距的简捷方法.  相似文献   
880.
Richmond (1982) uses a linear programming approach to the construction of simultaneous confidence intervals for a set of linear estimable parametric functions of the normal mean vector. We present a quadratic programming approach which constructs narrower confidence intervals than the linear programming approach given by Richmond (1982).  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