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   1330篇
  免费   55篇
管理学   279篇
民族学   10篇
人口学   113篇
丛书文集   2篇
理论方法论   117篇
综合类   21篇
社会学   570篇
统计学   273篇
  2023年   13篇
  2022年   7篇
  2021年   13篇
  2020年   38篇
  2019年   52篇
  2018年   85篇
  2017年   84篇
  2016年   71篇
  2015年   50篇
  2014年   72篇
  2013年   207篇
  2012年   84篇
  2011年   69篇
  2010年   56篇
  2009年   48篇
  2008年   68篇
  2007年   39篇
  2006年   40篇
  2005年   39篇
  2004年   34篇
  2003年   26篇
  2002年   35篇
  2001年   20篇
  2000年   16篇
  1999年   15篇
  1998年   9篇
  1997年   12篇
  1996年   7篇
  1995年   6篇
  1994年   3篇
  1993年   6篇
  1992年   2篇
  1991年   2篇
  1990年   8篇
  1988年   5篇
  1987年   3篇
  1986年   4篇
  1985年   3篇
  1984年   7篇
  1983年   3篇
  1982年   3篇
  1981年   3篇
  1980年   2篇
  1979年   3篇
  1974年   3篇
  1972年   3篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
排序方式: 共有1385条查询结果,搜索用时 281 毫秒
111.
112.
113.
114.
Suppose S is a positive definite m x m random matrix and S> Ω denotes the event that S—Ω is positive definite, Ω being a constant positive definite matrix. Under very mild regularity conditions, we show that the constraint Pr(S12 | S2) = Pr(S1) implies that S has a Wishart distribution on m+ 1 degrees of freedom.  相似文献   
115.
The paper introduces a new method for flexible spline fitting for copula density estimation. Spline coefficients are penalized to achieve a smooth fit. To weaken the curse of dimensionality, instead of a full tensor spline basis, a reduced tensor product based on so called sparse grids (Notes Numer. Fluid Mech. Multidiscip. Des., 31, 1991, 241‐251) is used. To achieve uniform margins of the copula density, linear constraints are placed on the spline coefficients, and quadratic programming is used to fit the model. Simulations and practical examples accompany the presentation.  相似文献   
116.
This paper studies the implementation of the coupling from the past (CFTP) method of Propp and Wilson (1996) in the set-up of two and three component mixtures with known components and unknown weights. We show that monotonicity structures can be exhibited in both cases, but that CFTP can still be costly for three component mixtures. We conclude with a simulation experiment exhibiting an almost perfect sampling scheme where we only consider a subset of the exhaustive set of starting values.  相似文献   
117.
In this study the attitude towards the new nationality law in Germany is explained by a value/expectancy theory of attitude. 215 standardized face-to-face-interviews were performed with a quota sample. The results of this survey show that the value and expectancy theory of attitude is extremely successful in explaining the attitude towards the new nationality law. Models explaining the predictor variable of the attitude theory and a feedback-model were tested.  相似文献   
118.
The paper analyzes different selection policies in education and business. We show that incorrect self-perceptions combined with imperfect performance measurement may cause significant welfare losses in selective educational systems, in particular if selection starts too early. Of course, these welfare losses can be mitigated by an investment in better ability assessment. However, an affirmative action policy could serve the same purpose as such an investment. We apply our analysis also to diversity management in firms. Based on positive discrimination we establish an efficiency argument for diversity management.  相似文献   
119.
This paper presents a review of empirical research on the impact of acquisitions on firm performance. The evidence suggests that, in the short run, acquisitions have at best an insignificant impact on shareholder wealth. Long‐run performance analysis reveals overwhelmingly negative returns, while the evidence using accounting performance measures is mixed. The review also examines the impact of bid characteristics on performance. The acquisition of hostile targets, transactions that are paid for with cash and acquisitions of larger targets are associated with superior (or at least less negative) performance, while there is mixed evidence on the benefits of related acquisitions. A number of recent studies find that acquirers with superior pre‐bid performance tend to experience significant underperformance in the post‐bid period.  相似文献   
120.
Time series of counts occur in many fields of practice, with the Poisson distribution as a popular choice for the marginal process distribution. A great variety of serial dependence structures of stationary count processes can be modelled by the INARMA family. In this article, we propose a new approach to the INMA(q) family in general, including previously known results as special cases. In the particular case of Poisson marginals, we will derive new results concerning regression properties and the serial dependence structure of INAR(1) and INMA(q) models. Finally, we present explicit expressions for the distribution of jumps in such processes.  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