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   1385篇
  免费   37篇
  国内免费   7篇
管理学   60篇
人才学   1篇
人口学   1篇
丛书文集   30篇
理论方法论   11篇
综合类   276篇
社会学   20篇
统计学   1030篇
  2023年   12篇
  2022年   12篇
  2021年   12篇
  2020年   19篇
  2019年   48篇
  2018年   51篇
  2017年   79篇
  2016年   38篇
  2015年   19篇
  2014年   46篇
  2013年   246篇
  2012年   89篇
  2011年   62篇
  2010年   49篇
  2009年   63篇
  2008年   47篇
  2007年   61篇
  2006年   60篇
  2005年   57篇
  2004年   52篇
  2003年   44篇
  2002年   38篇
  2001年   40篇
  2000年   32篇
  1999年   19篇
  1998年   19篇
  1997年   22篇
  1996年   8篇
  1995年   13篇
  1994年   7篇
  1993年   7篇
  1992年   8篇
  1991年   10篇
  1990年   4篇
  1989年   1篇
  1988年   8篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   5篇
  1982年   5篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
排序方式: 共有1429条查询结果,搜索用时 15 毫秒
291.
证明责任是证据制度的核心和关键所在.当一方当事人有优势持有证据而拒不提供时,对举证受阻的一方当事人应该有相应的救济途径和措施,并应责令妨碍举证的一方当事人承担相应的法律责任.由于法律规定的不完善,有必要构建举证时限制度、证据交换制度、证据申请和审查程序,并完善当事人取证制度,以调适、平衡诉讼双方当事人的诉讼能力和利益.  相似文献   
292.
Inference for a scalar interest parameter in the presence of nuisance parameters is considered in terms of the conditional maximum-likelihood estimator developed by Cox and Reid (1987). Parameter orthogonality is assumed throughout. The estimator is analyzed by means of stochastic asymptotic expansions in three cases: a scalar nuisance parameter, m nuisance parameters from m independent samples, and a vector nuisance parameter. In each case, the expansion for the conditional maximum-likelihood estimator is compared with that for the usual maximum-likelihood estimator. The means and variances are also compared. In each of the cases, the bias of the conditional maximum-likelihood estimator is unaffected by the nuisance parameter to first order. This is not so for the maximum-likelihood estimator. The assumption of parameter orthogonality is crucial in attaining this result. Regardless of parametrization, the difference in the two estimators is first-order and is deterministic to this order.  相似文献   
293.
We consider approximate Bayesian inference about the quantity R = P[Y2> Y1] when both the random variables Y1, Y2 have expectations that depend on certain explanatory variables. Our interest centers on certain characteristics of the posterior of R under Jeffreys's prior, such as its mean, variance and percentiles. Since the posterior of R is not available in closed form, several approximation procedures are introduced, and their relative performance is assessed using two real datasets.  相似文献   
294.
Summary In several studies the unit root hypothesis of EMS exchange rates is analysed within the context of devaluation expectations estimation. By means of bootstrap inference it is shown that these procedures are not compatible with standard Dickey-Fuller significance levels and may lead to a wrong rejection of the null hypothesis. In the case of the Italian Lira/Deutsche Mark exchange rate, the hypothesis of a unit root is not rejected and expectations can be modelled by means of a reflected Brownian motion. The estimated devaluation expectations are related with some macro variables which provide evidence for the structure of expectations. This research has been partially supported with 40% and 60% MURST grants. The author wishes to thank the Bank of Italy for the exchange rates and the interest rates data and Ulf S?derstr?m for providing macroeconomic indicators. Useful suggestions from Riccardo Cesari, Michele Costa and two anonymous referees are gratefully acknowledged.  相似文献   
295.
Issues that are central to the understanding and management of the HIV epidemic have generated numerous statistical challenges. This paper considers questions concerning the incubation period, the effects of treatments, pre diction of AIDS cases, the choice of surrogate end points for the assessment of treatments and design of strategies for screening blood samples. These issues give rise to a broad range of intriguing problems for statisticians. We describe some of these problems, how they have been tackled so far and what remains to be done. The discussion touches on topical statistical methods such as smoothing, bootstrapping, interval censoring and the ill-posed inverse problem, as well as asking fundamental questions for frequentist statistics.  相似文献   
296.
Consider a randomized trial in which time to the occurrence of a particular disease, say pneumocystic pneumonia in an AIDS trial or breast cancer in a mammographic screening trial, is the failure time of primary interest. Suppose that time to disease is subject to informative censoring by the minimum of time to death, loss to and end of follow-up. In such a trial, the potential censoring time is observed for all study subjects, including failures. In the presence of informative censoring, it is not possible to consistently estimate the effect of treatment on time to disease without imposing additional non-identifiable assumptions. Robins (1995) specified two non-identifiable assumptions that allow one to test for and estimate an effect of treatment on time to disease in the presence of informative censoring. The goal of this paper is to provide a class of consistent and reasonably efficient semiparametric tests and estimators for the treatment effect under these assumptions. The tests in our class, like standard weighted-log-rank tests, are asymptotically distribution-free -level tests under the null hypothesis of no causal effect of treatment on time to disease whenever the censoring and failure distributions are conditionally independent given treatment arm. However, our tests remain asymptotically distribution-free -level tests in the presence of informative censoring provided either of our assumptions are true. In contrast, a weighted log-rank test will be an -level test in the presence of informative censoring only if (1) one of our two non-identifiable assumptions hold, and (2) the distribution of time to censoring is the same in the two treatment arms. We also study the estimation, in the presence of informative censoring, of the effect of treatment on the evolution over time of the mean of repeated measures outcome such as CD4 count.  相似文献   
297.
Abstract

This article specializes the critical value (CV) methods that are based upon (refinements of) Bonferroni bounds, introduced by McCloskey to a problem of inference after consistent model selection in a general linear regression model. The post-selection problem is formulated to mimic common empirical practice and is applicable to both cross-sectional and time series contexts. We provide algorithms for constructing the CVs in this setting and establish uniform asymptotic size results for the resulting tests. The practical implementation of the CVs is illustrated in an empirical application to the effect of classroom size on test scores.  相似文献   
298.
Several estimators, including the classical and the regression estimators of finite population mean, are compared, both theoretically and empirically, under a calibration model, where the dependent variable(y), and not the independent variable(x), can be observed for all units of the finite population. It is shown asymptotically that when conditioned on x, the bias of the classical estimator may be much smaller than that of the regression estimators; whereas when conditioned on y, the regression estimator may have much smaller conditional bias than the classical estimator. Since all the y's(not x's) can be observed, it seems appropriate to make comparison under the conditional distribution of each estimator with y fixed. In this case, the regression estimator has smaller variance, smaller conditional bias, and the conditional coverage probability closer to its nominal level  相似文献   
299.
Abstract

The inverse Gaussian (IG) family is now widely used for modeling non negative skewed measurements. In this article, we construct the likelihood-ratio tests (LRTs) for homogeneity of the order constrained IG means and study the null distributions for simple order and simple tree order cases. Interestingly, it is seen that the null distribution results for the normal case are applicable without modification to the IG case. This supplements the numerous well known and striking analogies between Gaussian and inverse Gaussian families  相似文献   
300.
搜索引擎之竞价排名的法律问题研究   总被引:1,自引:0,他引:1  
搜索引擎以其全球性、实时性等特点在当今时代发展极为迅速,而竞价排名成为该类网站获得高额利润的首选方式。首先界定了竞价排名的性质以及运营模式,对因竞价排名而对网络用户、商家以及搜索引擎本身产生的影响进行阐述;其次对采取竞价排名的搜索引擎进行了法律责任认定;同时提出了在没有相应的法律对其规制的前提下,运用现有法律及法律基本原则保护合法权益、加强行业规制、建立健全法律制度等建议,以期待搜索引擎的健康发展。  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