首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
本文使用一种带有乘积调整的半参方法估计部分线性模型的非参数部分并给出所得估计的渐近性质。与传统的非参估计方法相比,我们所使用的半参数方法能够有效的降低所得估计的偏差,而方差不受影响。因此在积分均方误差(MISE)的意义下,该半参数方法要优于传统的估计方法。数值模拟也表明了这一点.  相似文献   

2.
利用重复观测数据和加权方法给出了有重复观测时变系数一维线性结构关系EV模型中的参数估计,证明了估计的弱相合性和强相合性.  相似文献   

3.
张君 《应用概率统计》2012,28(3):319-330
本文考虑了部分线性模型中,线性部分协变量含有测量误差,并且线性部分的参数随着样本量的增大而发散的估计问题.我们考虑了用可观测的替代变量来替代不可观察到的真实变量,这种替代变量的期望与真实变量存在线性关系.我们提出了估计方法,并研究了估计量的相合性与渐进正态性.此外,我们研究了发散参数的发散速度.我们通过模拟来说明该估计的实际效果.  相似文献   

4.
In this paper an efficient estimation methodology for the partially linear models with random effects is proposed. For this, we use the generalized least square estimate (GLSE) and the B-splines methods to estimate the unknowns, and employ the penalized least square method to obtain the estimators of the random effects item. Further, we also consider the estimation for the variance components. Compared with the existing methods, our proposed methodology performs well. The asymptotic properties of the estimators are obtained. A simulation study is carried out to assess the performance of our proposed methodology.  相似文献   

5.
The generalized partially linear additive model (GPLAM) is a flexible and interpretable approach to building predictive models. It combines features in an additive manner, allowing each to have either a linear or nonlinear effect on the response. However, the choice of which features to treat as linear or nonlinear is typically assumed known. Thus, to make a GPLAM a viable approach in situations in which little is known a priori about the features, one must overcome two primary model selection challenges: deciding which features to include in the model and determining which of these features to treat nonlinearly. We introduce the sparse partially linear additive model (SPLAM), which combines model fitting and both of these model selection challenges into a single convex optimization problem. SPLAM provides a bridge between the lasso and sparse additive models. Through a statistical oracle inequality and thorough simulation, we demonstrate that SPLAM can outperform other methods across a broad spectrum of statistical regimes, including the high-dimensional (p ? N) setting. We develop efficient algorithms that are applied to real datasets with half a million samples and over 45,000 features with excellent predictive performance. Supplementary materials for this article are available online.  相似文献   

6.
纵向数据是数理统计研究中的复杂数据类型之一0,在生物、医学和经济学中具有广泛的应用.在实际中经常需要对纵向数据进行统计分析和建模.文章讨论了纵向数据下的半参数变系数部分线性回归模型,这里的纵向数据的在纵向观察在时间上可以是不均等的,也可看成是按某一随机过程来发生.所研究的半参数变系数模型包括了许多半参数模型,比如部分线性模型和变系数模型等.利用计数过程理论和局部线性回归方法,对于纵向数据下半参数变系数进行了统计推断,给出了参数分量和非参数分量的profile最小二乘估计,研究了这些估计的渐近性质,获得这些估计的相合性和渐近正态性.  相似文献   

7.
In this paper, we consider the estimation problemfor partially linear models with additive measurement errors in thenonparametric part. Two kinds of estimators are proposed. The first oneis an integral moment-based estimator with deconvolution kernel techniques,associated with the strong consistency for the estimator. Another oneis a simulation-based estimator to avoid the integrals involved in theintegral moment-based estimator. Simulation studies are conducted toexamine the performance of the proposed estimators.  相似文献   

8.
The paper considers a multivariate partially linear model under independent errors,and investigates the asymptotic bias and variance-covariance for parametric component βand nonparametric component F(·)by the GJS estimator and Kernel estimation.  相似文献   

9.
纵向数据是在实际应用中很常见的一种数据类型,在解决实际问题时建立纵向数据模型,进行统计分析很实用。本文研究一类重要的纵向数据下部分线性回归模型,所分析的纵向数据是随机观测而得到的,根据纵向数据的特性构造模型中未知参数分量和未知函数的估计量,进而研究了估计量的渐近性质,通过实例分析,证实了该方法的有效性和可操作性,有很好的使用价值。  相似文献   

10.
In this paper, the semiparametric generalized partially linear models (GPLMs) for longitudinal data is studied. We approximate the nonparametric function in the GPLMs by a regression spline, and use quadratic inference functions (QIF) to take the within-cluster correlation into account without involving direct estimation of nuisance parameters in the correlation matrix. We establish the asymptotic normality of the resulting estimators. The finite sample performance of the proposed methods is evaluated through simulation studies and a real data analysis.  相似文献   

11.
本文讨论在数据是强相依的情况下函数系数部分线性模型的估计.首先,采用局部线性方法,给出该模型函数项函数的估计;然后,使用两阶段方法给出系数函数的估计.并且讨论了函数项函数估计的渐近正态性,以及系数函数估计的弱相合性和渐近正态性.模拟研究显示,这些估计是较为理想的.  相似文献   

12.
魏传华  吴喜之 《应用数学》2008,21(2):378-383
作为部分线性模型与变系数模型的推广,部分线性变系数模型是一类在建模中应用非常广泛的模型.本文基于Profile最小二乘方法给出了模型中误差方差的估计并证明了该估计的渐近正态性.最后通过数值模拟验证了我们所提估计方法的有效性.  相似文献   

13.
主要研究因变量存在缺失且协变量部分包含测量误差情形下,如何对变系数部分线性模型同时进行参数估计和变量选择.我们利用插补方法来处理缺失数据,并结合修正的profile最小二乘估计和SCAD惩罚对参数进行估计和变量选择.并且证明所得的估计具有渐近正态性和Oracle性质.通过数值模拟进一步研究所得估计的有限样本性质.  相似文献   

14.
In this paper, we consider the variable selection for the parametric components of varying coefficient partially linear models with censored data. By constructing a penalized auxiliary vector ingeniously, we propose an empirical likelihood based variable selection procedure, and show that it is consistent and satisfies the sparsity. The simulation studies show that the proposed variable selection method is workable.  相似文献   

15.
为了分析删失数据,该文考虑变系数部分线性模型,此模型允许协变量对响应变量存在非线性影响.响应变量与协变量之间关系的统计模型通过线性结构来拟合是非常重要而且有益.对于删失数据,常用的统计方法不能直接应用于此模型.该文首先提出一类数据变换用以建立无偏条件期望.然后利用profile最小二乘方法,给出了模型中参数分量和非参数分量的profile最小二乘估计,并建立了这些估计的渐近正态性.最后通过数值例子来说明该文所提出的方法的有效性.  相似文献   

16.
考虑回归模型yi=x′iβ+ g(ti) + ei, 0 ≤i ≤nr=Rβ其中(xi,ti)是固定非随机设计点列,xi=(xi1,…,xip)′,β=(β1,…,βp)′(p 1) ,g是定义在[0 ,1]上的未知函数,β是未知待估参数,0≤ ti≤1i,ei 是i.i.d随机误差,且Eei=0 ,Ee2i=σ2 <∞.r是一个J维向量,R是一个J* p列满秩矩阵,基于g的估计取一个非参数权估计,本文讨论了在线性约束下β的最小二乘估计的相合性及渐近正态性.  相似文献   

17.
Consider the partly linear model Y = xβ + g(t) + e where the explanatory x is erroneously measured,and both t and the response Y are measured exactly,the random error e is a martingale difference sequence.Let x be a surrogate variable observed instead of the true x in the primary survey data.Assume that in addition to the primary data set containing N observations of {(Y_j,x_j,t_j)_(j=n+1)~(n+N),the independent validation data containing n observations of {(x_j,x_j,t_j)_(j=1)~n} is available.In this paper,a semiparametric method with the primary data is employed to obtain the estimator of β and g(·) based on the least squares criterion with the help of validation data.The proposed estimators are proved to be strongly consistent.Finite sample behavior of the estimators is investigated via simulations too.  相似文献   

18.
本文研究了不等式约束条件下部分线性回归模型的参数估计问题,利用最优化方法和贝叶斯方法,给出了不等式约束条件下部分线性回归模型的最小二乘核估计和最佳贝叶斯估计,并且证明了在一定条件下,带约束条件的最小二乘核估计在均方误差意义下要优于无约束条件的最小二乘核估计。  相似文献   

19.
We propose the test statistic to check whether the nonparametric func-tions in two partially linear models are equality or not in this paper. We estimate the nonparametric function both in null hypothesis and the alternative by the local linear method, where we ignore the parametric components, and then estimate the parameters by the two stage method. The test statistic is derived, and it is shown to be asymptotically normal under the null hypothesis.  相似文献   

20.
Consider the semiparametric varying-coefficient heteroscedastic partially linear model Y i = Xτiβ + Zτiα(Ti) + σiei,1 ≤ i ≤ n,where σ 2 i = f(Ui),β is a p × 1 column vector of unknown parameter,(Xi,Zi,Ti,Ui) are random design points,Y i are the response variables,α(·) is a q-dimensional vector of unknown functions,e i are random errors.For both cases that f(·) is known and unknown,we propose the empirical log-likelihood ratio statistics for the parameter β.For each case,a nonparametric version of Wilks’ theorem is derived.The results are then used to construct confidence regions of the parameter.Simulation studies are carried out to assess the performance of the empirical likelihood method.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号