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1.
李元  黄香  叶伟彰 《中国科学A辑》2006,36(10):1131-1142
在非参数回归模型的讨论中, 通常假定方差具有齐性结构. 然而事前并不能保证方差齐性. 因此需要检验异方差性. 基于小波方法提出了一种相合的非参数异方差检验. 首先定义了回归模型的条件方差函数的经验小波系数, 然后证明了其渐近正态性. 在此基础上, 利用 Fan 的小波收缩的概念, 提出了异方差性检验的统计量. 模拟结果表明, 本检验方法优于传统的非参数检验方法.  相似文献   

2.
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   

3.
陈敏 《应用数学学报》2002,25(4):577-590
门限自回归模型被广泛地用于许多领域,当建立或使用这类模型时,一个重要问题是需要知道是否存在条件异方差。在本文中,我们对这个问题提出一个非参数检验,检验的大样本理论被给出,我们还通过数值模拟研究了检验方法的有限样本性质。结果表示检验有好的功效。经验百分位点还被给出。  相似文献   

4.
本文讨论了条件异方差双门限自回归模型的门限和延时的识别问题,通过经验小波系数,给出了门限个数和门限以及延时的估计,在较弱的条例下,证明了所给的估计是相合的。  相似文献   

5.
半参数回归模型的异方差统计分析   总被引:5,自引:0,他引:5  
在回归分析中,方差齐性的假设是一个普遍关心的问题.在参数和非参数回归模型中,关于异方差检验问题已经有很多的研究,见(【1】,【4】,【7】).本文研究了半参数回归模型的异方差检验问题,得到了方差齐性检验的SCORE统计量,证明了该统计量的渐近x^2性质,最后给出计算机模拟和实际例子,推广和发展了Eubank和Thomas(1993),韦博成(1995)的工作.  相似文献   

6.
史宁中  刘继春 《东北数学》2001,17(3):323-332
In this paper,by making use of the Hadamard product of matrices,a natural and reasonable generalization of the univariate GARCH(Generalized Autoregressive Conditional heteroscedastic)process introduced by Bollerslev(J.Econometrics 31(1986),307-327)to the multivariate case is proposed.The conditions for the existence of strictly stationary and ergodic solutions and the existence of higher order moments for this class of parametric models are derived.  相似文献   

7.
本文对一类非线性时间序列模型xt=φ(xt-1,…,xt-p)+εth(xt-1,…,xt-p)给出了高阶矩的存在条件。  相似文献   

8.
回归信度模型在保险研究中具有重要的作用.本文分险种内部,险种之间,险种内部及之间三种情形讨论了具有线性趋势回归信度模型异方差的score检验问题.首先推导了异方差存在性检验的score检验统计量,然后利用Monte-Carlo方法模拟了这几种检验统计量的功效,功效模拟结果显示:这几种检验统计量都有很好的检验效果.最后利用文中所得到的检验方法对旅客意外身体伤害保险数据进行了实例分析.  相似文献   

9.
非对称广义自回归条件异方差的新模型   总被引:4,自引:0,他引:4  
本文提出了一个新的非对称广义自回归条件异方差的新模型,证明了该模型宽平稳及其最简模型偶数价矩存在的充要条件。  相似文献   

10.
研究随机设计下非参数回归模型方差变点Ratio检验.首先用局部多项式方法估计回归曲线得到残差序列,其次基于残差的平方序列构造Ratio检验统计量并推导检验统计量的极限分布.最后数值模拟与实例分析结果表明方法的有效性.  相似文献   

11.
In the additive regression models, the single-index model is considered commonly for high dimensional regression analysis. The specification of this model that it is more flexible compared with a parametric model, and it avoids the curse of dimensionality because the single-index reduces the dimensionality of a standard variable vector (x in the multi-regression) to a univariate index (\beta^\T X in the single-index model). In this paper, we developed a single-index regression model with a functional errors' term that serves in checking the heteroscedasticity. Since the efficient inference of a regression model demands that heteroscedasticity is regarded when it exists, this paper presents the assumptions of testing variance constancy in single-index models. The test statistic is assessing the variance homogeneity stated as a combination of Levene's test and the theories of ANOVA for the infinite factor levels. The test statistic in the simulation studies displays appropriately in all situations compared to a well-known method and applies to a real dataset.  相似文献   

12.
??In the additive regression models, the single-index model is considered commonly for high dimensional regression analysis. The specification of this model that it is more flexible compared with a parametric model, and it avoids the curse of dimensionality because the single-index reduces the dimensionality of a standard variable vector (x in the multi-regression) to a univariate index (\beta^\T X in the single-index model). In this paper, we developed a single-index regression model with a functional errors' term that serves in checking the heteroscedasticity. Since the efficient inference of a regression model demands that heteroscedasticity is regarded when it exists, this paper presents the assumptions of testing variance constancy in single-index models. The test statistic is assessing the variance homogeneity stated as a combination of Levene's test and the theories of ANOVA for the infinite factor levels. The test statistic in the simulation studies displays appropriately in all situations compared to a well-known method and applies to a real dataset.  相似文献   

13.
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   

14.
部分线性模型中的非参数部分的线性性检验   总被引:1,自引:0,他引:1  
In this paper,we propose the test statistic to check whether the nonpara- metric function in partially linear models is linear or not.We estimate the nonpara- metric function in alternative by using the local linear method,and then estimate the parameters by the two stage method.The test statistic under the null hypothesis is calculated,and it is shown to be asymptotically normal.  相似文献   

15.
本文基于非参数可加回归模型的局部核权最小二乘法提出变量间非线性协整的一种非参数检验方法。  相似文献   

16.
Efficient Estimation in a Semiparametric Autoregressive Model   总被引:3,自引:0,他引:3  
This paper constructs efficient estimates of the parameter in the semiparametric auto-regression model ,with a smooth function and independent and identically distributed innovations t with zero means and finite variances. This will be done under the assumptions that and that the errors have a density with finite Fisher information for location. The former condition guarantees that the process can be chosen to be stationary and ergodic.  相似文献   

17.
18.
本文考虑部分自回归模型 X_t=X_(t-1)β g(U_t) ε_t,t≥1.这里g是一未知函数,β是一待估参数,ε_j是具有0均值和方差σ~2的i.i.d.误差,U_t i.i.d.服从[0,1]上均匀分布.本文首先给出了相合估计的收敛阶和Takeuchi意义下渐近有效界.同时给出了β最小二乘估计是有效的充要条件.最后证明了MLE是渐近有效的.  相似文献   

19.
We consider a polygonal line process based on residual partial sums of a stationary Hilbert space-valued autoregressive process. Its convergence to a Hilbert space-valued Brownian motion is established in the framework of Hölder spaces. The relevance of the results to the problem of testing stability of {ARH}$(1)$ model under different types of alternatives is discussed.  相似文献   

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