全文获取类型
收费全文 | 539篇 |
免费 | 19篇 |
专业分类
管理学 | 42篇 |
民族学 | 2篇 |
人口学 | 40篇 |
丛书文集 | 30篇 |
理论方法论 | 6篇 |
综合类 | 181篇 |
社会学 | 21篇 |
统计学 | 236篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 19篇 |
2016年 | 6篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 109篇 |
2012年 | 32篇 |
2011年 | 33篇 |
2010年 | 21篇 |
2009年 | 26篇 |
2008年 | 38篇 |
2007年 | 31篇 |
2006年 | 19篇 |
2005年 | 17篇 |
2004年 | 28篇 |
2003年 | 21篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有558条查询结果,搜索用时 15 毫秒
71.
For each positive integer k, a set of k-principal points of a distribution is the set of k points that optimally represent the distribution in terms of mean squared distance. However, explicit form of k-principal points is often difficult to obtain. Hence a theorem established by Tarpey et al. (1995) has been influential in the literature, which states that when the distribution is elliptically symmetric, any set of k-principal points is in the linear subspace spanned by some principal eigenvectors of the covariance matrix. This theorem is called a “principal subspace theorem”. Recently, Yamamoto and Shinozaki (2000b) derived a principal subspace theorem for 2-principal points of a location mixture of spherically symmetric distributions. In their article, the ratio of mixture was set to be equal. This article derives a further result by considering a location mixture with unequal mixture ratio. 相似文献
72.
For the analysis of survey-weighted categorical data, one recommended method of analysis is a log-rate model. For each cell in a contingency table, the survey weights are averaged across subjects and incorporated into an offset for a loglinear model. Supposedly, one can then proceed with the analysis of unweighted observed cell counts. We provide theoretical and simulation-based evidence to show that the log-rate analysis is not an effective statistical analysis method and should not be used in general. The root of the problem is in its failure to properly account for variability in the individual weights within cells of a contingency table. This results in goodness-of-fit tests that have higher-than-nominal error rates and confidence intervals for odds ratios that have lower-than-nominal coverage. 相似文献
73.
A control procedure is presented in this article that is based on jointly using two separate control statistics in the detection and interpretation of signals in a multivariate normal process. The procedure detects the following three situations: (i) a mean vector shift without a shift in the covariance matrix; (ii) a shift in process variation (covariance matrix) without a mean vector shift; and (iii) both a simultaneous shift in the mean vector and covariance matrix as the result of a change in the parameters of some key process variables. It is shown that, following the occurrence of a signal on either of the separate control charts, the values from both of the corresponding signaling statistics can be decomposed into interpretable elements. Viewing the two decompositions together helps one to specifically identify the individual components and associated variables that are being affected. These components may include individual means or variances of the process variables as well as the correlations between or among variables. An industrial data set is used to illustrate the procedure. 相似文献
74.
This article proposes a new spatial cluster detection method for longitudinal outcomes that detects neighborhoods and regions with elevated rates of disease while controlling for individual level confounders. The proposed method, CumResPerm, utilizes cumulative geographic residuals through a permutation test to detect potential clusters which are defined as sets of administrative regions, such as a town or group of administrative regions. Previous cluster detection methods are not able to incorporate individual level data including covariate adjustment, while still being able to define potential clusters using informative neighborhood or town boundaries. Often, it is of interest to detect such spatial clusters because individuals residing in a town may have similar environmental exposures or socioeconomic backgrounds due to administrative reasons, such as zoning laws. Therefore, these boundaries can be very informative and more relevant than arbitrary clusters such as the standard circle or square. Application of the CumResPerm method will be illustrated by the Home Allergens and Asthma prospective cohort study analyzing the relationship between area or neighborhood residence and repeated measured outcome, occurrence of wheeze in the last six months, while taking into account mobile locations. 相似文献
75.
To assess the efficacy of a treatment, patients are administered a pre-test, the treatment, and a post-test (identical to the pre-test). These patients are then categorized according to their outcomes observed on both tests,e.g., (S,S), (S,F), etc. Also, we observe "incomplete" information on the pre-tests' outcomes for some patients and the results of only the post-test being known for thers, A Bayesian framework is fit to the problem and Bayes factors, posterior odds ratios, and utility functions are given to evaluate th e treatment, A method of assessing the prior distribution is specified and a numerical example is worked. 相似文献
76.
Wilks's A was factorized by Bartlett (1951) for testing the hypothesis of goodness of fit of a hypothetical discriminant function in the case of several groups. This test has applications in various areas such as Econometrics, contingency tables, growth curves, principal components analysis, design of experiments and so on. This paper gives a consolidated account of the research done in these areas on the application of factors of Wilks's A 相似文献
77.
Zhi Geng 《统计学通讯:理论与方法》2013,42(12):4137-4146
This paper is concerned wim ine maximum likelihood estimation and the likelihood ratio test for hierarchical loglinear models of multidimensional contingency tables with missing data. The problems of estimation and test for a high dimensional contingency table can be reduced into those for a class of low dimensional tables. In some cases, the incomplete data in the high dimensional table can become complete in the low dimensional tables through the reduction can indicate how much the incomplete data contribute to the estimation and the test. 相似文献
78.
Shulamith T. Gross 《统计学通讯:理论与方法》2013,42(3):1027-1037
Bayes credibility limits for small proportions from stratified and fixed size cluster samples are discussed. Ericson’s (JRSS B (1969)) Beta Binomial and Dirichlet-Multinomial priors are used. Approximate limits that are appropriate for large samples and small proportions are derived in both cases. These allow asymptotic comparisons of the efficacy of stratified and cluster sampling relative to simple random sampling for estimating small proportions. Procedures for the selection of hyper parameters are also presented. 相似文献
79.
ABSTRACTIn panel data models and other regressions with unobserved effects, fixed effects estimation is often paired with cluster-robust variance estimation (CRVE) to account for heteroscedasticity and un-modeled dependence among the errors. Although asymptotically consistent, CRVE can be biased downward when the number of clusters is small, leading to hypothesis tests with rejection rates that are too high. More accurate tests can be constructed using bias-reduced linearization (BRL), which corrects the CRVE based on a working model, in conjunction with a Satterthwaite approximation for t-tests. We propose a generalization of BRL that can be applied in models with arbitrary sets of fixed effects, where the original BRL method is undefined, and describe how to apply the method when the regression is estimated after absorbing the fixed effects. We also propose a small-sample test for multiple-parameter hypotheses, which generalizes the Satterthwaite approximation for t-tests. In simulations covering a wide range of scenarios, we find that the conventional cluster-robust Wald test can severely over-reject while the proposed small-sample test maintains Type I error close to nominal levels. The proposed methods are implemented in an R package called clubSandwich. This article has online supplementary materials. 相似文献
80.
精算是保险发展的基础,是保险经营的技术支持。精算在国外有四百年的发展历史,引入中国只有二十年。要使精算技术在中国得到发展创新并为社会需要服务,必须了解精算思想产生的历史背景,厘清精算理论发展的脉络,真正把握精算思想的实质。基于此,介绍了精算各发展时期的主要代表人物及其学术思想,阐述精算技术对各时期保险发展的影响,同时对精算学与复利理论、数学、统计学、计算技术、金融经济学交叉融合的历史过程进行了分析述评。 相似文献