全文获取类型
| 收费全文 | 602篇 |
| 免费 | 8篇 |
| 国内免费 | 1篇 |
专业分类
| 管理学 | 42篇 |
| 人口学 | 15篇 |
| 丛书文集 | 23篇 |
| 理论方法论 | 5篇 |
| 综合类 | 84篇 |
| 社会学 | 29篇 |
| 统计学 | 413篇 |
出版年
| 2024年 | 3篇 |
| 2023年 | 3篇 |
| 2022年 | 7篇 |
| 2021年 | 13篇 |
| 2020年 | 16篇 |
| 2019年 | 25篇 |
| 2018年 | 20篇 |
| 2017年 | 35篇 |
| 2016年 | 11篇 |
| 2015年 | 24篇 |
| 2014年 | 17篇 |
| 2013年 | 167篇 |
| 2012年 | 52篇 |
| 2011年 | 31篇 |
| 2010年 | 24篇 |
| 2009年 | 15篇 |
| 2008年 | 17篇 |
| 2007年 | 17篇 |
| 2006年 | 17篇 |
| 2005年 | 10篇 |
| 2004年 | 16篇 |
| 2003年 | 4篇 |
| 2002年 | 9篇 |
| 2001年 | 13篇 |
| 2000年 | 5篇 |
| 1999年 | 4篇 |
| 1998年 | 6篇 |
| 1997年 | 6篇 |
| 1996年 | 1篇 |
| 1995年 | 2篇 |
| 1994年 | 1篇 |
| 1993年 | 4篇 |
| 1992年 | 5篇 |
| 1991年 | 3篇 |
| 1986年 | 2篇 |
| 1985年 | 1篇 |
| 1984年 | 1篇 |
| 1982年 | 1篇 |
| 1977年 | 1篇 |
| 1976年 | 1篇 |
| 1975年 | 1篇 |
排序方式： 共有611条查询结果，搜索用时 0 毫秒
71.
Merve Kandemir Çetinkaya Selahattin Kaçıranlar 《Journal of Statistical Computation and Simulation》2019,89(14):2645-2660
Negative binomial regression (NBR) and Poisson regression (PR) applications have become very popular in the analysis of count data in recent years. However, if there is a high degree of relationship between the independent variables, the problem of multicollinearity arises in these models. We introduce new two-parameter estimators (TPEs) for the NBR and the PR models by unifying the two-parameter estimator (TPE) of Özkale and Kaç?ranlar [The restricted and unrestricted two-parameter estimators. Commun Stat Theory Methods. 2007;36:2707–2725]. These new estimators are general estimators which include maximum likelihood (ML) estimator, ridge estimator (RE), Liu estimator (LE) and contraction estimator (CE) as special cases. Furthermore, biasing parameters of these estimators are given and a Monte Carlo simulation is done to evaluate the performance of these estimators using mean square error (MSE) criterion. The benefits of the new TPEs are also illustrated in an empirical application. The results show that the new proposed TPEs for the NBR and the PR models are better than the ML estimator, the RE and the LE. 相似文献
72.
Kimberly F. Sellers Derek S. Young 《Journal of Statistical Computation and Simulation》2019,89(9):1649-1673
While excess zeros are often thought to cause data over-dispersion (i.e. when the variance exceeds the mean), this implication is not absolute. One should instead consider a flexible class of distributions that can address data dispersion along with excess zeros. This work develops a zero-inflated sum-of-Conway-Maxwell-Poissons (ZISCMP) regression as a flexible analysis tool to model count data that express significant data dispersion and contain excess zeros. This class of models contains several special case zero-inflated regressions, including zero-inflated Poisson (ZIP), zero-inflated negative binomial (ZINB), zero-inflated binomial (ZIB), and the zero-inflated Conway-Maxwell-Poisson (ZICMP). Through simulated and real data examples, we demonstrate class flexibility and usefulness. We further utilize it to analyze shark species data from Australia's Great Barrier Reef to assess the environmental impact of human action on the number of various species of sharks. 相似文献
73.
Cord A. Müller 《Journal of applied statistics》2019,46(13):2338-2356
ABSTRACTAcceptance sampling plans offered by ISO 2859-1 are far from optimal under the conditions for statistical verification in modules F and F1 as prescribed by Annex II of the Measuring Instruments Directive (MID) 2014/32/EU, resulting in sample sizes that are larger than necessary. An optimised single-sampling scheme is derived, both for large lots using the binomial distribution and for finite-sized lots using the exact hypergeometric distribution, resulting in smaller sample sizes that are economically more efficient while offering the full statistical protection required by the MID. 相似文献
74.
Modeling spatial overdispersion requires point process models with finite‐dimensional distributions that are overdisperse relative to the Poisson distribution. Fitting such models usually heavily relies on the properties of stationarity, ergodicity, and orderliness. In addition, although processes based on negative binomial finite‐dimensional distributions have been widely considered, they typically fail to simultaneously satisfy the three required properties for fitting. Indeed, it has been conjectured by Diggle and Milne that no negative binomial model can satisfy all three properties. In light of this, we change perspective and construct a new process based on a different overdisperse count model, namely, the generalized Waring (GW) distribution. While comparably tractable and flexible to negative binomial processes, the GW process is shown to possess all required properties and additionally span the negative binomial and Poisson processes as limiting cases. In this sense, the GW process provides an approximate resolution to the conundrum highlighted by Diggle and Milne. 相似文献
75.
In studies with recurrent event endpoints, misspecified assumptions of event rates or dispersion can lead to underpowered trials or overexposure of patients. Specification of overdispersion is often a particular problem as it is usually not reported in clinical trial publications. Changing event rates over the years have been described for some diseases, adding to the uncertainty in planning. To mitigate the risks of inadequate sample sizes, internal pilot study designs have been proposed with a preference for blinded sample size reestimation procedures, as they generally do not affect the type I error rate and maintain trial integrity. Blinded sample size reestimation procedures are available for trials with recurrent events as endpoints. However, the variance in the reestimated sample size can be considerable in particular with early sample size reviews. Motivated by a randomized controlled trial in paediatric multiple sclerosis, a rare neurological condition in children, we apply the concept of blinded continuous monitoring of information, which is known to reduce the variance in the resulting sample size. Assuming negative binomial distributions for the counts of recurrent relapses, we derive information criteria and propose blinded continuous monitoring procedures. The operating characteristics of these are assessed in Monte Carlo trial simulations demonstrating favourable properties with regard to type I error rate, power, and stopping time, ie, sample size. 相似文献
76.
The professionalization of evaluation continues to be debated at numerous conferences in the U.S. and abroad. At this time, AEA member views on the potential benefits and negative side effects of professionalization are essential as the discussion evolves. This study provides recent views on major topics in professionalization, including potential benefits, negative side effects, processes, competencies, and procedures. Results from in-depth interviews and an online survey demonstrate that AEA members view potential benefits of professionalization to be stakeholder trust, evaluator reputation and identity, while concerns about a potential negative side effect known as the “narrowing effect” (i.e., some evaluators will be alienated based on their background, competencies, etc.) were expressed by participants. These recent findings can inform the ongoing discussion of professionalization, and suggest new directions for future research on evaluation. 相似文献
77.
In this paper, we consider a generalisation of the backward simulation method of Duch et al. [New approaches to operational risk modeling. IBM J Res Develop. 2014;58:1–9] to build bivariate Poisson processes with flexible time correlation structures, and to simulate the arrival times of the processes. The proposed backward construction approach uses the Marshall–Olkin bivariate binomial distribution for the conditional law and some well-known families of bivariate copulas for the joint success probability in lieu of the typical conditional independence assumption. The resulting bivariate Poisson process can exhibit various time correlation structures which are commonly observed in real data. 相似文献
78.
Shonosuke Sugasawa Tatsuya Kubokawa Kota Ogasawara 《Scandinavian Journal of Statistics》2017,44(3):684-706
Random effects model can account for the lack of fitting a regression model and increase precision of estimating area‐level means. However, in case that the synthetic mean provides accurate estimates, the prior distribution may inflate an estimation error. Thus, it is desirable to consider the uncertain prior distribution, which is expressed as the mixture of a one‐point distribution and a proper prior distribution. In this paper, we develop an empirical Bayes approach for estimating area‐level means, using the uncertain prior distribution in the context of a natural exponential family, which we call the empirical uncertain Bayes (EUB) method. The regression model considered in this paper includes the Poisson‐gamma and the binomial‐beta, and the normal‐normal (Fay–Herriot) model, which are typically used in small area estimation. We obtain the estimators of hyperparameters based on the marginal likelihood by using a well‐known expectation‐maximization algorithm and propose the EUB estimators of area means. For risk evaluation of the EUB estimator, we derive a second‐order unbiased estimator of a conditional mean squared error by using some techniques of numerical calculation. Through simulation studies and real data applications, we evaluate a performance of the EUB estimator and compare it with the usual empirical Bayes estimator. 相似文献
79.
Marco Barnabani 《统计学通讯:模拟与计算》2017,46(1):331-343
In general, the exact distribution of a convolution of independent gamma random variables is quite complicated and does not admit a closed form. Of all the distributions proposed, the gamma-series representation of Moschopoulos (1985) is relatively simple to implement but for particular combinations of scale and/or shape parameters the computation of the weights of the series can result in complications with too much time consuming to allow a large-scale application. Recently, a compact random parameter representation of the convolution has been proposed by Vellaisamy and Upadhye (2009) and it allows to give an exact interpretation to the weights of the series. They describe an infinite discrete probability distribution. This result suggested to approximate Moschopoulos’s expression looking for an approximating theoretical discrete distribution for the weights of the series. More precisely, we propose a general negative binomial distribution. The result is an “excellent” approximation, fast and simple to implement for any parameter combination. 相似文献
80.
Serkan Eryilmaz 《统计学通讯:模拟与计算》2017,46(10):8005-8013
In this article, a system that consists of n independent components each having two dependent subcomponents (Ai, Bi), i = 1, …, n is considered. The system is assumed to compose of components that have two correlated subcomponents (Ai, Bi), and functions iff both systems of subcomponents A1, A2, …, An and B1, B2, …, Bn work under certain structural rules. The expressions for reliability and mean time to failure of such systems are obtained. A sufficient condition to compare two systems of bivariate components in terms of stochastic ordering is also presented. 相似文献