方差分量模型中回归系数的线性Minimax估计

考虑方差分量(混合线性)模型y=Xβ+U1ξ1+U2ξ2+…+Ukξk,这里Xn×p,Ui,n×ti为已知设计矩阵,βp×1是固定效应,iξ是ti×1随机效应向量,满足E(iξ)=0,cov(iξ)=σ2iIti,iξ都不相关.往往Uk=In,ξk=ek,即最后一项为随机误差,热β∈RP和i2σ>0(i=1,2,…,k)为未知参数.我们考虑β的可估函数Sβ,选取二次损失函数L(d,Sβ)=(d-Sβ)′(d-Sβ)∑ki=1ciσi2+β′X′Vk-1Xβ,然后在线性估计类中给出Sβ的惟一的mini max估计.     

正态线性模型中随机回归系数和参数的Minimax估计

该文在一般正态随机效应线性模型中研究了随机回归系数和参数的估计问题. 在二次损失下，得到了线性可估函数在一切估计类中的唯一Minimax估计.     

A Unified and Broadened Class of Admissible Minimax Estimators of a Multivariate Normal Mean

The problem of estimating the mean of a multivariate normal distribution is considered. A class of admissible minimax estimators is constructed. This class includes two well-known classes of estimators, Strawderman's and Alam's. Further, this class is much broader than theirs.     

All Admissible Linear Estimators under Quadratic Loss in Multivariate Model

§ 1.Introduction and Notations　In this paper,for any given matrices A and B,A B denotes the Kronecker productof A and B,A is a vector formed by stacking the columns of A under each other,μ(A)is a space generated by the columns of A,and PA=A(A′A) - A′. Fourthmore,if A andB are square matrices,then A>B and A≥ B mean that A-B is a symmetrical positiveand nonnegative matrix,respectively,andλi(A) is the i-th largest eigenvalue of A.　Consider general multivariate linear modelY …     

Minimax estimation of means of multivariate normal mixtures

Assume X = (X₁, …, X_p)′ is a normal mixture distribution with density w.r.t. Lebesgue measure, , where Σ is a known positive definite matrix and F is any known c.d.f. on (0, ∞). Estimation of the mean vector under an arbitrary known quadratic loss function _Q(θ, a) = (a − θ)′ Q(a − θ), Q a positive definite matrix, is considered. An unbiased estimator of risk is obatined for an arbitrary estimator, and a sufficient condition for estimators to be minimax is then achieved. The result is applied to modifying all the Stein estimators for the means of independent normal random variables to be minimax estimators for the problem considered here. In particular the results apply to the Stein class of limited translation estimators.     

方差分量线性模型中回归系数和参数的所有可容许线性估计

对固定效应方差分量模型，在矩阵损失（ｄ－Ｓ＿τ）（ｄ－Ｓ＿τ）＇下，我们给出了线性可估函数Ｓτ的线性估计在一切估计类中可容许的充要条件；对具有两个方差分量的随机效应线性模型在矩阵损失（ｄ－Ｓα－Ｑβ）（ｄ－Ｓα－Ｑβ）＇下，我们给出了线性可估函数Ｓα＋Ｑβ的线性估计在一切估计类中可容许的充要条件。     

部分线性模型的随机约束岭估计

研究了部分线性回归模型附加有随机约束条件时的估计问题.基于Profile最小二乘方法和混合估计方法提出了参数分量随机约束下的Profile混合估计,并研究了其性质.为了克服共线性问题,构造了参数分量的Profile混合岭估计,并给出了估计量的偏和方差.     

二次损失下G-M模型中可估函数的条件Minimax估计与性质

在二次损失下关于任意矩阵V对G-M模型讨论了齐次线性估计类中可估函数的条件Mimimax估计与性质。     

均值矩阵的函数的所有可容许估计

对于多元正态线性模型Ｙｎｘｍ～Ｎ（Ｘθ,σ２∑Ｖ）,在四种不同的可容许意义下,本文研究了ＳＸθ的线性估计ＬＹ＋Ｄ在一切估计类中的可容许性在适当条件下得到了充要条件,在一般情况给出了充分条件和必要条件．     

矩阵损失下随机回归系数和参数的线性Minimax估计

对于一般的随机效应线性模型Y=Xβ+ε,这里β和ε分别是p维和n维的随机向量,且E(βε)=(Aa0),Cov(βε)=σ2(V10 0V2),(Vi≥0,i=1,2)我们定义了Sα+Qβ的线性Minimax估计,在一定条件下得到了Sα+Qβ在线性估计类中的Minimax估计,并在几乎处处意义下证明了它的唯一性.     

多元线性模型中回归系数的线性可容许估计

基于Zellner的平衡损失的思想,本文提出了矩阵形式的平衡损失函数,并在该损失函数下讨论了多元回归系数线性估计的可容许性.给出了六种不同形式的可容许定义,证明了这六种容许性在齐次和非齐次线性估计类中是一致的,且得到了其共同的可容许估计的充要条件.     

聚集数据下回归系数混合估计的相对效率

讨论在聚集数据情形下,具有附加信息的线性回归模型的参数估计,提出了回归系数的聚集混合估计,研究了该估计相对于Peter—Karsten估计和相对于最小二乘估计的相对效率,得到了相对效率的上、下界.     

回归系数的广义岭型主相关估计及其优良性

In this paper, we propose a new biased estimator of the regression parameters, the generalized ridge and principal correlation estimator. We present its some properties and prove that it is superior to LSE （least squares estimator）, principal correlation estimator, ridge and principal correlation estimator under MSE （mean squares error） and PMC （Pitman closeness） criterion, respectively.     

A New Class of Consistent Estimators for Stochastic Linear Regressive Models

In this paper we propose a new approach for estimating the unknown parameter in the stochastic linear regressive model with stationary ergodic sequence of covariates. Under mild conditions on the joint distribution of the covariate and the error, the estimator constructed is shown to be strongly consistent in two important special cases: (1) The sequence of (variate, covariate) is independent identically distributed (i.i.d.), and (2) the sequence of variates is a stationary autoregressive series. The asymptotical normality is also discussed under more assumptions on the distribution of the covariate.     

A Class of Linear Biased Estimators of Regression ParameterMatrix in the Growth Curve Model

ＡＣｌａｓｓｏｆＬｉｎｅａｒＢｉａｓｅｄＥｓｔｉｍａｔｏｒｓｏｆＲｅｇｒｅｓｓｉｏｎＰａｒａｍｅｔｅｒＭａｔｒｉｘｉｎｔｈｅＧｒｏｗｔｈＣｕｒｖｅＭｏｄｅｌ￥ＧｕｉＱｉｎｇｍｉｎｇ（ＺｈｅｎｇｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＳｕｒｖｅｙｉｎｇａｎｄＭａ...     

Minimax multivariate empirical Bayes estimators under multicollinearity

In this paper we consider the problem of estimating the matrix of regression coefficients in a multivariate linear regression model in which the design matrix is near singular. Under the assumption of normality, we propose empirical Bayes ridge regression estimators with three types of shrinkage functions, that is, scalar, componentwise and matricial shrinkage. These proposed estimators are proved to be uniformly better than the least squares estimator, that is, minimax in terms of risk under the Strawderman's loss function. Through simulation and empirical studies, they are also shown to be useful in the multicollinearity cases.     

线性模型回归系数c-(K,S)型估计的优良性

根据线性回归模型Y=Xβ+ε,E(ε)=0,COV(ε)=σ~2I,对回归系数的有偏估计c-(K,S)型估计进一步研究;讨论了c-(K,S)型估计的优良性,在一定的条件下获得β_c(K,S)估计与LS估计的相对效率的界,并由此得出在设计阵病态时,β_c(K,S)型估计的精度明显高于LS估计;最后,证明了c-(K,S)型估计的可容许性,从而有助于病态线性回归系数有偏估计的进一步改进.     

测量误差数据下线性模型的几乎无偏岭估计

文章讨论带测量误差的线性模型中参数估计的问题.当带测量误差的线性模型存在复共线的时候,通过几乎无偏估计的思想,提出了几乎无偏岭估计,并对估计的性质进行分析.通过研究发现几乎无偏岭估计不但能克服复共线性,同时有比较小的均方误差.     

Minimax estimation of a multivariate normal mean under arbitrary quadratic loss

Let X be a p-variate (p ≥ 3) vector normally distributed with mean θ and known covariance matrix

. It is desired to estimate θ under the quadratic loss (δ ? θ)^tQ(δ ? θ), where Q is a known positive definite matrix. A broad class of minimax estimators for θ is developed.     

线性模型回归系数的c-(K,S)型估计的小样本性质

根据线性回归模型Y=Xβ+,εE(ε)=0,COV(ε)=σ2,对回归系数的有偏估计c-(K,S)型估计进一步研究;讨论了c-(K,S)型估计的基本性质;并在均方误差阵(M SEM)准则下讨论了c-(K,S)型估计相对于最小二乘估计的优良性,有助于线性回归系数有偏估计的进一步改进.