全文获取类型
收费全文 | 85篇 |
免费 | 2篇 |
专业分类
管理学 | 14篇 |
人口学 | 1篇 |
理论方法论 | 12篇 |
社会学 | 31篇 |
统计学 | 29篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 25篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有87条查询结果,搜索用时 31 毫秒
1.
2.
3.
In a special paired sample case, Hotelling’s T2 test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given. 相似文献
4.
Data collected in various scientific fields are count data. One way to analyze such data is to compare the individual levels of the factor treatment using multiple comparisons. However, the measured individuals are often clustered – e.g. according to litter or rearing. This must be considered when estimating the parameters by a repeated measurement model. In addition, ignoring the overdispersion to which count data is prone leads to an increase of the type one error rate. We carry out simulation studies using several different data settings and compare different multiple contrast tests with parameter estimates from generalized estimation equations and generalized linear mixed models in order to observe coverage and rejection probabilities. We generate overdispersed, clustered count data in small samples as can be observed in many biological settings. We have found that the generalized estimation equations outperform generalized linear mixed models if the variance-sandwich estimator is correctly specified. Furthermore, generalized linear mixed models show problems with the convergence rate under certain data settings, but there are model implementations with lower implications exists. Finally, we use an example of genetic data to demonstrate the application of the multiple contrast test and the problems of ignoring strong overdispersion. 相似文献
5.
This experiment elicits beliefs about other people’s overconfidence and abilities. We find that most people believe that others
are unbiased, and only few think that others are overconfident. There is a remarkable heterogeneity between these groups.
Those people who think others are underconfident or unbiased are overconfident themselves. Those who think others are overconfident
are underconfident themselves. Despite this heterogeneity, people overestimate on average the abilities of others as they
do their own ability. One driving force behind this result is the refusal to process information about oneself: not only does
this lead to overestimation of one’s own ability, but by means of social projection also to overestimation of others’ abilities. 相似文献
6.
We develop a simple OLG model to analytically show that aging leads to increased educational efforts through a general equilibrium
effect. The mechanism is that scarcity of raw labor increases the return of human relative to physical capital. While a reduction
in the birth rate is shown to unambiguously increase educational efforts, increases in the survival rate have ambiguous effects.
Falling birth rates also increase capital per worker, but the effects of rising survival rates are again ambiguous. We conclude
that our model is a useful laboratory to highlight potentially offsetting effects in models with endogenous education and
overlapping generations. 相似文献
7.
Ecosystem restoration is critically important in urbanized landscapes because habitat degradation is severe and ubiquitous in such areas. Because successful restoration requires specification of desired environmental endpoints, a generally applicable method for valuing and comparing possible restoration endpoints is needed. One method available for comparative valuation is the Analytical Hierarchy Process (AHP). AHP allows a suite of alternatives to be valued on a rank scale based on simple, tractable, paired comparisons among all alternatives. Given a sound technical foundation for the paired comparisons, the method yields an objective set of rank values. By incorporating the relative values of various restoration alternatives in a restoration scaling evaluation such as a Habitat Equivalency Analysis (HEA), restoration programs can be designed effectively both qualitatively (in terms of the kinds of resources or habitats desired) and quantitatively (in terms of the amounts or areas of each). In this study, we develop and apply AHP in the context of a specimen HEA for US Mid-Atlantic coast estuaries. By ranking various habitat types as potential restoration targets based on their value for a suite of key natural resources, a series of restoration ratios is produced, relating relative habitat areas of each type needed to offset specific impairment levels. These ratios provide a basic tool for restoration planning in urbanized estuaries, as these comprise nearly entirely built environments with little or no natural habitat. Under these conditions, restoration planners must specify desired states of the ecosystem, and the restoration ratios allow various permutations of presumed post-restoration environments to be valued and compared. 相似文献
8.
The most serious problem facing the United States, accordingto many scientific and political leaders, is the threat of nuclearwar. Yet the standard survey question on the most importantproblem facing the country has often shown little public concurrencewith this assumption. Our article uses experimentation in nationalsamples to test whether this difference can be traced to limitationsin either the form or the wording of the standard question.The results indicate that there are some important systematicdifferences between open and closed versions of the question,and also differences that result from reference to the nationas distinct from the world, but neither type of difference accountsfor the infrequent mention of nuclear war on the standard question.Instead, other evidence indicates that most Americans believethat nuclear war is not going to happen at all, or that if itdoes happen it will be too far in the distant future to be ofpressing concern to them personally. 相似文献
9.
The present paper explores the structure of linear exponential families for which the sample variance is a uniformly minimum variance unbiased estimator. 相似文献
10.