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   336篇
  免费   10篇
管理学   34篇
民族学   4篇
人口学   23篇
理论方法论   16篇
综合类   3篇
社会学   118篇
统计学   148篇
  2024年   1篇
  2023年   4篇
  2022年   5篇
  2021年   5篇
  2020年   16篇
  2019年   9篇
  2018年   25篇
  2017年   33篇
  2016年   29篇
  2015年   10篇
  2014年   16篇
  2013年   104篇
  2012年   15篇
  2011年   4篇
  2010年   9篇
  2009年   14篇
  2008年   8篇
  2007年   10篇
  2006年   1篇
  2005年   3篇
  2004年   3篇
  2003年   1篇
  1999年   1篇
  1998年   2篇
  1995年   1篇
  1994年   1篇
  1992年   4篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
  1984年   3篇
  1982年   1篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有346条查询结果,搜索用时 46 毫秒
91.
92.
In this article, we aim to understand the development dynamics of a specific area of social investment (SI), that is, childcare policies, in the context of postcommunist politics and the recent right-wing turn that took place in the Czech Republic, Hungary, and Poland. This article identifies varieties of channels for promoting SI. First, in taking the perspective of the “mixed economy of welfare,” we argue that attempts made to introduce elements of SI to the childcare policies involved various leading roles available for either the private sector or state/public domain. Second, it is important to distinguish between implicit/unintended and explicit/intended projects both in relation to cases in which SI strategy is applied via marketization/privatization and when it involves a government-led project. Third, we take into account the politics of SI implementation that might involve applying certain principles central to policy concepts (such as “investment”) in justifying policy instruments incompatible with original ideas. Although arguments about SI have been extensively used by Eastern European leaders, their goal has been to justify welfare reforms that were implicitly or explicitly directed towards the middle class while excluding the “nondeserving” often based on ethnic identity. We characterize Poland as a case of “implicit marketization,” the Czech Republic as a case of “explicit privatization,” and the Hungarian version of SI as a case of “explicit public dualization.” In this, we show that in some cases, the implementation of SI approaches by right-wing populist parties might rear its “ugly” head.  相似文献   
93.

Urban green areas have become an important tool for biodiversity conservation in cities. However, land use and the different management practices applied to these areas determine their effectiveness as biodiversity refuges within cities. In our study, we compare the biodiversity of three bioindicator groups of arthropods (ants, spiders and harvestmen) found in eleven urban green sites in Warsaw (Poland). The studied sites represent three categories of management: botanical gardens, public parks and urban woodlands. Our aim was to determine the effect of the type of management (as urban green categories) on arthropod communities in urban areas.

  相似文献   
94.
Recently Li and Shaked [2007. A general family of univariate stochastic orders. J. Statist. Plann. Inference 137, 3601–3610] introduced the generalized total time on test (GTTT) transform with respect to a given function ??. In this paper we study some properties of it which are related with stochastic orderings. A concept of Lehmann and Rojo [1992. Invariant directional orderings. Ann. Statist. 20, 2100–2110] is applied to a new setting and the GTTT transform is used to define invariance properties and distances of some stochastic orders. Iterations of the GTTT transforms are also studied and their relations with exponential mixtures of gamma distributions are established.  相似文献   
95.
We consider asymptotic properties of the maximum likelihood and related estimators in a clustered logistic joinpoint model with an unknown joinpoint. Sufficient conditions are given for the consistency of confidence bounds produced by the parametric bootstrap; one of the conditions required is that the true location of the joinpoint is not at one of the observation times. A simulation study is presented to illustrate the lack of consistency of the bootstrap confidence bounds when the joinpoint is an observation time. A removal algorithm is presented which corrects this problem, but at the price of an increased mean square error. Finally, the methods are applied to data on yearly cancer mortality in the US for individuals age 65 and over.  相似文献   
96.
The purpose of this paper is to characterize optimal designs under a multivariate linear model with additional nuisance parameters. We give relationships between optimality of designs in univariate models and in their multivariate extensions with known and partially known dispersion matrices.  相似文献   
97.
On MSE of EBLUP   总被引:1,自引:1,他引:0  
We consider Best Linear Unbiased Predictors (BLUPs) and Empirical Best Linear Unbiased Predictors (EBLUPs) under the general mixed linear model. The BLUP was proposed by Henderson (Ann Math Stat 21:309–310, 1950). The formula of this BLUP includes unknown elements of the variance-covariance matrix of random variables. If the elements in the formula of the BLUP proposed by Henderson (Ann Math Stat 21:309–310, 1950) are replaced by some type of estimators, we obtain the two-stage predictor called the EBLUP which is model-unbiased (Kackar and Harville in Commun Stat A 10:1249–1261, 1981). Kackar and Harville (J Am Stat Assoc 79:853–862, 1984) show an approximation of the mean square error (the MSE) of the predictor and propose an estimator of the MSE. The MSE and estimators of the MSE are also studied by Prasad and Rao (J Am Stat Assoc 85:163–171, 1990), Datta and Lahiri (Stat Sin 10:613–627, 2000) and Das et al. (Ann Stat 32(2):818–840, 2004). In the paper we consider the BLUP proposed by Royall (J Am Stat Assoc 71:657–473, 1976. Ża̧dło (On unbiasedness of some EBLU predictor. Physica-Verlag, Heidelberg, pp 2019–2026, 2004) shows that the BLUP proposed by Royall (J Am Stat Assoc 71:657–473, 1976) may be treated as a generalisation of the BLUP proposed by Henderson (Ann Math Stat 21:309–310, 1950) and proves model unbiasedness of the EBLUP based on the formula of the BLUP proposed by Royall (J Am Stat Assoc 71:657–473, 1976) under some assumptions. In this paper we derive the formula of the approximate MSE of the EBLUP and its estimators. We prove that the approximation of the MSE is accurate to terms o(D −1) and that the estimator of the MSE is approximately unbiased in the sense that its bias is o(D −1) under some assumptions, where D is the number of domains. The proof is based on the results obtained by Datta and Lahiri (Stat Sin 10:613–627, 2000). Using our results we show some EBLUP based on the special case of the general linear model. We also present the formula of its MSE and estimators of its MSE and their performance in Monte Carlo simulation study.   相似文献   
98.
A random stopping set is defined and some of its properties are proved. Namely, we prove the theorem on the absolute continuity of measures on a σ-algebra Fτ connected with a random stopping set τ, which can be applied to the sequential analysis of random measures and fields.  相似文献   
99.
100.
Given an undirected, connected graph G with maximum degree Δ, we introduce the concept of a [1, Δ]-factor k-packing in G, defined as a set of k edge-disjoint subgraphs of G such that every vertex of G has an incident edge in at least one subgraph. The problem of deciding whether a graph admits a [1,Δ]-factor k-packing is shown to be solvable in linear time for k = 2, but NP-complete for all k≥ 3. For k = 2, the optimisation problem of minimising the total number of edges of the subgraphs of the packing is NP-hard even when restricted to subcubic planar graphs, but can in general be approximated within a factor of by reduction to the Maximum 2-Edge-Colorable Subgraph problem. Finally, we discuss implications of the obtained results for the problem of fault-tolerant guarding of a grid, which provides the main motivation for research.  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