全文获取类型
收费全文 | 369篇 |
免费 | 11篇 |
学科分类
社会科学 | 380篇 |
出版年
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 15篇 |
2019年 | 22篇 |
2018年 | 26篇 |
2017年 | 25篇 |
2016年 | 21篇 |
2015年 | 8篇 |
2014年 | 19篇 |
2013年 | 60篇 |
2012年 | 48篇 |
2011年 | 13篇 |
2010年 | 15篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有380条查询结果,搜索用时 15 毫秒
61.
Walmes Marques Zeviani Paulo Justiniano Ribeiro Jr Wagner Hugo Bonat Silvia Emiko Shimakura Joel Augusto Muniz 《Journal of applied statistics》2014,41(12):2616-2626
Event counts are response variables with non-negative integer values representing the number of times that an event occurs within a fixed domain such as a time interval, a geographical area or a cell of a contingency table. Analysis of counts by Gaussian regression models ignores the discreteness, asymmetry and heteroscedasticity and is inefficient, providing unrealistic standard errors or possibly negative predictions of the expected number of events. The Poisson regression is the standard model for count data with underlying assumptions on the generating process which may be implausible in many applications. Statisticians have long recognized the limitation of imposing equidispersion under the Poisson regression model. A typical situation is when the conditional variance exceeds the conditional mean, in which case models allowing for overdispersion are routinely used. Less reported is the case of underdispersion with fewer modeling alternatives and assessments available in the literature. One of such alternatives, the Gamma-count model, is adopted here in the analysis of an agronomic experiment designed to investigate the effect of levels of defoliation on different phenological states upon the number of cotton bolls. Data set and code for analysis are available as online supplements. Results show improvements over the Poisson model and the semi-parametric quasi-Poisson model in capturing the observed variability in the data. Estimating rather than assuming the underlying variance process leads to important insights into the process. 相似文献
62.
Tena Elena Fandos Guillermo de Paz Óscar de la Peña Roberto Tellería José Luis 《Urban Ecosystems》2020,23(2):227-234
Urban Ecosystems - We studied the occurrence of bats in urban parks in the city of Madrid (Spain), and the resulting patterns were compared with bat occurrence in the surrounding region. In this... 相似文献
63.
Canedoli Claudia Ferrè Chiara El Khair Davide Abu Padoa-Schioppa Emilio Comolli Roberto 《Urban Ecosystems》2020,23(1):159-171
Urban Ecosystems - Urban areas are major producers of atmospheric CO2 emissions, but at the same time they can offset some of the associated C losses by retaining stable organic carbon in their... 相似文献
64.
Oliveira Flávio G. Tapisso Joaquim T. von Merten Sophie Rychlik Leszek Fonseca Paulo J. Mathias Maria da Luz 《Urban Ecosystems》2021,24(5):851-862
Urban Ecosystems - The development of urban areas imposes challenges that wildlife must adapt to in order to persist in these new habitats. One of the greatest changes brought by urbanization has... 相似文献
65.
Andrew McLennan Paulo K. Monteiro Rabee Tourky 《Econometrica : journal of the Econometric Society》2011,79(5):1643-1664
We provide a pure Nash equilibrium existence theorem for games with discontinuous payoffs whose hypotheses are in a number of ways weaker than those of the theorem of Reny (1999). In comparison with Reny's argument, our proof is brief. Our result subsumes a prior existence result of Reny (1999) that is not covered by his theorem. We use the main result to prove the existence of pure Nash equilibrium in a class of finite games in which agents' pure strategies are subsets of a given set, and in turn use this to prove the existence of stable configurations for games, similar to those used by Schelling (1971, 1972) to study residential segregation, in which agents choose locations. 相似文献
66.
67.
68.
The tobit model allows a censored response variable to be described by covariates. Its applications cover different areas such as economics, engineering, environment and medicine. A strong assumption of the standard tobit model is that its errors follow a normal distribution. However, not all applications are well modeled by this distribution. Some efforts have relaxed the normality assumption by considering more flexible distributions. Nevertheless, the presence of asymmetry could not be well described by these flexible distributions. A real-world data application of measles vaccine in Haiti is explored, which confirms this asymmetry. We propose a tobit model with errors following a Birnbaum–Saunders (BS) distribution, which is asymmetrical and has shown to be a good alternative for describing medical data. Inference based on the maximum likelihood method and a type of residual are derived for the tobit–BS model. We perform global and local influence diagnostics to assess the sensitivity of the maximum likelihood estimators to atypical cases. A Monte Carlo simulation study is carried out to empirically evaluate the performance of these estimators. We conduct a data analysis for the mentioned application of measles vaccine based on the proposed model with the help of the R software. The results show the good performance of the tobit–BS model. 相似文献
69.
Many white noise and goodness-of-fit tests are (asymptotically) written as quadratic forms in the ordinary autocorrelation estimates. The properties of such tests are studied by investigating the structure of the matrix of the quadratic form. We suggest to choose the matrix of the quadratic form in such a way that the power is maximized according to the information available about the alternative hypothesis. A simulation study sheds some light on the behavior of the test in finite samples. It is generally found more powerful than the most popular portmanteau tests, i.e., the Box and Pierce and the Ljung and Box tests. 相似文献
70.