共查询到19条相似文献,搜索用时 187 毫秒
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在许多实际问题中,检验观察数据是否出现异方差性是一个相当感兴趣的问题.该文研究了半参数随机效应模型的异方差检验问题.基于Lin(1997)的方法,得到了检验方差成分都为零的Score检验统计量.通过随机模拟和实际数值例子,论证了方法的有效性.利用现有的统计软件,容易实现该文所提出的检验方法. 相似文献
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该文讨论了带有随机设计的非参数回归模型的异方差小波检验. 首先给出了回归模型的条件方差函数的经验小波系数, 然后证明了它们是渐近独立和正态的. 基于 Fan (1996) 的方法, 构造了异方差检验统计量.最后通过数值模拟,作者检验了该文所提出的方法的有效性.模拟结果表明该文所提出的检验方法在水平和功效方面表现良好. 相似文献
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在回归分析中,观测值的方差齐性只是一个基本的假定,在参数、半参数和非参数回归模型中关于异方差检验和估计问题已有很多研究.本文在冉昊和朱忠义(2004)讨论的半参数回归模型的基础上,用随机参数方法,讨论随机权函数半参数回归模型中的异方差检验问题,得到了方差齐性检验Score统计量,同时,当半参数模型存在异方差时,本文还给出了估计方差的方法. 相似文献
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对多个只含有个体效应的Panel数据模型,研究了模型中回归系数向量相等性的假设检验问题,提出了一种参数Bootstrap检验方法.有限样本的数值模拟研究结果表明,提出的检验方法具有良好.的检验功效,且受个体效应方差、误差方差、模型个数、回归系数维数的影响不明显. 相似文献
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组间方差和自相关系数的齐性是纵向数据分析的基本假设之一,然而这种假设需要进行统计检验. Zhang \&; Weiss$^{[15]}$ 讨论了线性随机效应模型的组间和组内方差齐性的检验问题;林金官 \&; 韦博成$^{[10]}$ 研究了具有AR(1)误差但没有随机效应的非线性模型的自相关系数的齐性检验.该文研究具有随机效应和AR(1)误差的非线性模型的组间方差和自相关系数的齐性检验问题,构造了几个score检验统计量, 并通过Monte Carlo模拟方法研究了检验统计量的性质.最后利用该文的方法分析一组实际数据和一组模拟数据. 相似文献
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在参数和非参数回归模型中,关于异方差检验、一阶自相关存在性检验以及附加变量检验问题都有很多的研究.文中利用P-样条方法,研究了单指标模型的异方差、一阶自相关存在性及附加变量检验问题,分别得到了三种情况下的Score检验统计量,最后给出计算机模拟和实际例子,证实了文中所提出的方法的可行性和有效性,推广和发展了先前的工作. 相似文献
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In this article, we consider the problem of testing a linear hypothesis in a multivariate linear regression model which includes the case of testing the equality of mean vectors of several multivariate normal populations with common covariance matrix Σ, the so-called multivariate analysis of variance or MANOVA problem. However, we have fewer observations than the dimension of the random vectors. Two tests are proposed and their asymptotic distributions under the hypothesis as well as under the alternatives are given under some mild conditions. A theoretical comparison of these powers is made. 相似文献
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线性混合模型中方差分量的广义推断 总被引:1,自引:0,他引:1
本文考虑了线性混合模型中方差分量的假设检验和区间估计问题.基于广义P-值和广义置信区间的概念,构造了对应于随机效应的单个方差分量的精确检验和置信区间.所构造的广义p-值和广义置信区间是最小充分统计量的函数.对于两个独立线性混合模型中对应于随机效应的方差分量的比较,建立了精确检验和置信区间.进-步,研究了所给检验和置信区间的统计性质,给出了这些检验方法与文献中已有方法的功效比较的模拟结果.模拟结果表明,新检验在功效方面有显著的改进.最后,通过-个实例来演示本文方怯. 相似文献
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In this paper we consider a general variance components model for combining experiments that allows for a possible interaction of responses with groups. The variance estimate from each experiment cannot take into account this interaction which can additionally be different from experiment to experiment. The interaction term can be interpreted as an additional variance component so that we consider an extended ANOVA model. We derive confidence regions and test of hypotheses on the variance components which – at least approximately – hold the nominal significance level. 相似文献
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P. Parpas B. Rustem V. Wieland S. Žaković 《Computational Optimization and Applications》2009,43(2):235-259
In this paper, we consider expected value, variance and worst–case optimization of nonlinear models. We present algorithms
for computing optimal expected value, and variance policies, based on iterative Taylor expansions. We establish convergence
and consider the relative merits of policies based on expected value optimization and worst–case robustness. The latter is
a minimax strategy and ensures optimal cover in view of the worst–case scenario(s) while the former is optimal expected performance
in a stochastic setting.
Both approaches are used with a small macroeconomic model to illustrate relative performance, robustness and trade-offs between
the alternative policies. 相似文献
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Estimating the error distribution in nonparametric multiple regression with applications to model testing 总被引:1,自引:0,他引:1
Natalie Neumeyer 《Journal of multivariate analysis》2010,101(5):1067-1078
In this paper we consider the estimation of the error distribution in a heteroscedastic nonparametric regression model with multivariate covariates. As estimator we consider the empirical distribution function of residuals, which are obtained from multivariate local polynomial fits of the regression and variance functions, respectively. Weak convergence of the empirical residual process to a Gaussian process is proved. We also consider various applications for testing model assumptions in nonparametric multiple regression. The model tests obtained are able to detect local alternatives that converge to zero at an n−1/2-rate, independent of the covariate dimension. We consider in detail a test for additivity of the regression function. 相似文献
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In this paper we consider the estimating problem of a semiparametric regression modelling whenthe data are longitudinal.An iterative weighted partial spline least squares estimator(IWPSLSE)for the para-metric component is proposed which is more efficient than the weighted partial spline least squares estimator(WPSLSE)with weights constructed by using the within-group partial spline least squares residuals in the sense 相似文献
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对于部分线性模型中非参数部分是否为某一特定阶数(记为p)的多项式函数的检验问题,本文基于非参数函数在各点的p阶导函数估计值的样本方差构造了一个简单的检验统计量.给出了计算检验p-值的三阶矩χ2逼近方法.最后通过数值模拟验证了我们所提检验方法的有效性. 相似文献
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Leandro Chaves Rêgo Andrea Maria dos Santos 《European Journal of Operational Research》2019,272(2):587-594
We generalize a network formation model for co-authorship introducing the possibility of the connections having different link strengths. Different link strengths represent the fact that authors may put different efforts into different collaborations. To evaluate the model, we consider the notions of efficiency and pairwise stability, which are based on a utility function that measures the benefits for an author to belonging to a certain network structure. We divide the analysis in two cases, considering that link strengths are unbounded or bounded. In the first case, we show that if there are more than two authors in the network, then there is no pairwise stable network. In the second case, we show that the pairwise stable networks consist of completely connected disjoint components where essentially all link strengths are maximal. Regarding efficiency, in both cases, if the number of authors is even, then the unique efficient network structure consists of pairs of connected authors. 相似文献