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   2096篇
  免费   72篇
  国内免费   13篇
管理学   165篇
民族学   2篇
人口学   16篇
丛书文集   43篇
理论方法论   11篇
综合类   422篇
社会学   33篇
统计学   1489篇
  2024年   2篇
  2023年   12篇
  2022年   13篇
  2021年   22篇
  2020年   43篇
  2019年   61篇
  2018年   66篇
  2017年   126篇
  2016年   64篇
  2015年   60篇
  2014年   64篇
  2013年   575篇
  2012年   161篇
  2011年   65篇
  2010年   53篇
  2009年   68篇
  2008年   67篇
  2007年   66篇
  2006年   54篇
  2005年   73篇
  2004年   55篇
  2003年   36篇
  2002年   59篇
  2001年   53篇
  2000年   31篇
  1999年   28篇
  1998年   31篇
  1997年   27篇
  1996年   17篇
  1995年   9篇
  1994年   9篇
  1993年   16篇
  1992年   18篇
  1991年   10篇
  1990年   9篇
  1989年   9篇
  1988年   9篇
  1987年   5篇
  1986年   3篇
  1985年   5篇
  1984年   8篇
  1983年   5篇
  1982年   1篇
  1981年   5篇
  1980年   1篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   3篇
排序方式: 共有2181条查询结果,搜索用时 31 毫秒
31.
Conditional value-at-risk (CVaR) model is a kind of financial risk measure that is extensively supported and accepted by international financial community. Its optimized form can be regarded as an optimized certainty equivalent (OCE) risk measurement. In this paper, we mainly discuss and analyze the strong laws of large numbers and the convergence rate of OCE's estimator under α-mixing sequences. The result shows that the almost sure convergence rate of CVaR estimator is given by the results of OCE estimator. Its convergence rate is inversely proportional to the square root of the sample size under certain conditions. Its effectiveness is verified by simulation experiments for two classical α-mixing sequences.  相似文献   
32.
The Theil, Pietra, Éltetö and Frigyes measures of income inequality associated with the Pareto distribution function are expressed in terms of parameters defining the Pareto distribution. Inference procedures based on the generalized variable method, the large sample method, and the Bayesian method for testing of, and constructing confidence interval for, these measures are discussed. The results of Monte Carlo study are used to compare the performance of the suggested inference procedures from a population characterized by a Pareto distribution.  相似文献   
33.
We present a variational estimation method for the mixed logistic regression model. The method is based on a lower bound approximation of the logistic function [Jaakkola, J.S. and Jordan, M.I., 2000, Bayesian parameter estimation via variational methods. Statistics & Computing, 10, 25–37.]. Based on the approximation, an EM algorithm can be derived that results in a considerable simplification of the maximization problem in that it does not require the numerical evaluation of integrals over the random effects. We assess the performance of the variational method for the mixed logistic regression model in a simulation study and an empirical data example, and compare it to Laplace's method. The results indicate that the variational method is a viable choice for estimating the fixed effects of the mixed logistic regression model under the condition that the number of outcomes within each cluster is sufficiently high.  相似文献   
34.
高校是“立德树人”培养高素质人才的基地,始终坚持在党的领导下办好中国特色社会主义高校,需要在思想和行动上执行好“四种形态”。正确认识当前高校践行“四种形态”存在的“精细治理”“文化管理”“经验管束”“粗放管理”等“四级样态”,对于高校党组织更好推进“四种形态”在高校落地生根具有重要意义  相似文献   
35.
The Bayesian paradigm provides an ideal platform to update uncertainties and carry them over into the future in the presence of data. Bayesian predictive power (BPP) reflects our belief in the eventual success of a clinical trial to meet its goals. In this paper we derive mathematical expressions for the most common types of outcomes, to make the BPP accessible to practitioners, facilitate fast computations in adaptive trial design simulations that use interim futility monitoring, and propose an organized BPP-based phase II-to-phase III design framework.  相似文献   
36.
In this paper, we study the empirical Bayes (EB) estimation in continuous one-parameter exponential families under negatively associated (NA) samples and positively associated (PA) samples. Under certain regularity conditions, it is shown that the convergence rates of proposed EB estimators under NA or PA samples are the same as those of EB estimators under independent observations, which significantly improve the existing results in EB estimation under associated samples.  相似文献   
37.
Assume that there are two types of insurance contracts in an insurance company, and the ith related claims are denoted by {Xij, j ? 1}, i = 1, 2. In this article, the asymptotic behaviors of precise large deviations for non random difference ∑n1(t)j = 1X1j ? ∑n2(t)j = 1X2j and random difference ∑N1(t)j = 1X1j ? ∑N2(t)j = 1X2j are investigated, and under several assumptions, some corresponding asymptotic formulas are obtained.  相似文献   
38.
The authors study the strong convergence for sequences of pairwise negatively quadrant dependent (NQD) random variables under some wide conditions, and present some new theorems on the complete convergence and the strong laws of large numbers. The obtained results extend and improve some theorems in existing literature.  相似文献   
39.
The use of robust measures helps to increase the precision of the estimators, especially for the estimation of extremely skewed distributions. In this article, a generalized ratio estimator is proposed by using some robust measures with single auxiliary variable under the adaptive cluster sampling (ACS) design. We have incorporated tri-mean (TM), mid-range (MR) and Hodges-Lehman (HL) of the auxiliary variable as robust measures together with some conventional measures. The expressions of bias and mean square error (MSE) of the proposed generalized ratio estimator are derived. Two types of numerical study have been conducted using artificial clustered population and real data application to examine the performance of the proposed estimator over the usual mean per unit estimator under simple random sampling (SRS). Related results of the simulation study show that the proposed estimators provide better estimation results on both real and artificial population over the competing estimators.  相似文献   
40.
In this paper, we propose a multiple deferred state repetitive group sampling plan which is a new sampling plan developed by incorporating the features of both multiple deferred state sampling plan and repetitive group sampling plan, for assuring Weibull or gamma distributed mean life of the products. The quality of the product is represented by the ratio of true mean life and specified mean life of the products. Two points on the operating characteristic curve approach is used to determine the optimal parameters of the proposed plan. The plan parameters are determined by formulating an optimization problem for various combinations of producer's risk and consumer's risk for both distributions. The sensitivity analysis of the proposed plan is discussed. The implementation of the proposed plan is explained using real-life data and simulated data. The proposed plan under Weibull distribution is compared with the existing sampling plans. The average sample number (ASN) of the proposed plan and failure probability of the product are obtained under Weibull, gamma and Birnbaum–Saunders distributions for a specified value of shape parameter and compared with each other. In addition, a comparative study is made between the ASN of the proposed plan under Weibull and gamma distributions.  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