Lomax分布极大似然估计的两点研究

本文研究了Lomax分布参数极大似然估计的存在性和估计量的收敛性问题.利用严格的分析法和中心极限定理,获得了Lomax分布极大似然估计的存在性和估计量的渐近正态分布的结果,进一步推广到了有缺失数据的两个Lomax总体中,参数的极大似然估计有强相合性和渐近正态性.     

半参数模型的经验欧氏似然估计的大样本性质

本文证明了半参数模型的经验欧氏似然估计的强相合性和渐近正态性,还证明了经验欧氏似然比统计量的渐近x~2分布性,最后给出了几个例子。     

指数族非线性模型最大似然估计的相合性和渐近正态性

本文我们提出了一些正则条件, 这些条件减弱了Zhu and Wei (1997)文中的条件. 基于所提的正则条件, 我们证明了指数族非线性模型参数最大似然估计的相合性和渐近正态性. 我们的结果可被认为是Zhu and Wei (1997)工作的进一步改进.     

随机截尾情形下Rayleigh分布参数的最大似然估计

研究了随机截尾情形下Rayleigh分布参数的最大似然估计,研究了最大似然估计的存在唯一性;在很一般的条件下证明了估计的强、弱相合性和渐近正态性.     

随机过程极大似然估计的强相合性

本文运用现代鞅论和随机积分作为工具来讨论随机过程参数估计的极大似然方法的强相合性,得到了一些充分条件。本文还推广了P. E. Caines 1975年对有限参数集合情形下的工作。     

经验欧氏似然的大样本性质

本文讨论了强平稳 m相依样本半参数模型的经验欧氏分布函数的相合性及经验欧氏似然比统计量的渐近 χ2分布性 .     

广义线性模型极大似然估计的强相合性与渐近正态性

本文研究了若干重要类型的离散响应变量广义线性模型,在sum from i=1 to n ZiZi'的最小特征根大于cnα(对某个c>0,α>0)等条件下证明了回归参数向量的极大似然估计的强相合性与渐近正态性,其中设计阵序列{||Zn||}可以为无界序列.     

三种两样本经验Euclidean似然方法及其比较

本文研究三种两样本经验Euclidean似然方法，基于两个无偏估计函数的经验Euclidean似然方法，基于一个无偏估计函数和一个历史经验估计的经验Euclidean惩罚似然方法，基于两个经验估计的加权和方法，我们研究了这些方法的强相合性，渐近正态性和渐近有效性，研究表明，这三种方法是同等渐近有效的。     

广义线性模型中极大拟似然估计的渐近正态性与强相合性

在广义线性模型中,当λn→∞,supi≥1 E||ei||2+α<∞(对某个α>0), 且其他一些正则条件满足时,证明了极大拟似然估计(MQLE)是渐近正态的;进 一步假定 ,证明了MQLE是强相合的,其中λn(λn) 是∑i=1 nZiZiT的最小(最大)特征根,Zi是有界的p×q回归系数,ei=yi-Eyi,yi 是q×1响应变量．也讨论了设计阵Zi是自适应的情形．     

带自适应设计的拟似然非线性模型中极大拟似然估计的强相合性

在带自适应设计的拟似然非线性模型中,在响应变量的矩条件尽可能弱和其它正则条件下,证明了以概率为1,当n充分大时,拟似然方程有一个解βn,它收敛于参数真值β0.     

两个未知均值方差混合模型有限制下对数极大似然比的极限分布

本文讨论了检验样本是来自一个正态总体还是两个未知均值和方差的正态的混合分布,采用对数极大似然比的检验,如果不加限制,Ｈａｒｔｉｎｇａｎｍ曾指出不是寻找的、Ｘ＾２分布,我们在混合的中了一点后得到了其极限分布产工给出了分位点数值表。     

Bootstrapping Log Likelihood and EIC, an Extension of AIC

Akaike (1973, 2nd International Symposium on Information Theory, 267-281,Akademiai Kiado, Budapest) proposed AIC as an estimate of the expected loglikelihood to evaluate the goodness of models fitted to a given set of data.The introduction of AIC has greatly widened the range of application ofstatistical methods. However, its limit lies in the point that it can beapplied only to the cases where the parameter estimation are performed bythe maximum likelihood method. The derivation of AIC is based on theassessment of the effect of data fluctuation through the asymptoticnormality of MLE. In this paper we propose a new information criterion EICwhich is constructed by employing the bootstrap method to simulate the datafluctuation. The new information criterion, EIC, is regarded as an extensionof AIC. The performance of EIC is demonstrated by some numerical examples.     

Asymptotically optimal estimation in the linear regression problem in the case of violation of some classical assumptions

We consider the problem of estimating the unknown parameters of linear regression in the case when the variances of observations depend on the unknown parameters of the model. A two-step method is suggested for constructing asymptotically linear estimators. Some general sufficient conditions for the asymptotic normality of the estimators are found, and an explicit form is established of the best asymptotically linear estimators. The behavior of the estimators is studied in detail in the case when the parameter of the regression model is one-dimensional.     

On Sample Size and Quick Simultaneous Confidence Interval Estimations for Multinomial Proportions

Abstract

Asymptotically, sample proportions from a multinomial distribution converge in distribution to a multivariate normal distribution with a singular negative product correlation structure. Based on this result, we propose a new approach to estimate the sample size requirement for constructing quick simultaneous confidence intervals (QSCI) for multinomial proportions. In addition, this new approach can be used to construct QSCI and provides a statistical justification to the reports of the opinion polling.     

分数扩散模型的参数估计及其应用

研究分数扩散模型的参数估计及其应用问题.分数扩散模型是一类由分数Brownian运动驱动的随机微分方程.主要结果有:(1)利用二次变差方法给出模型中扩散系数的估计量,通过最小二乘法给出模型中漂移系数的估计量;(2)证明这些估计量的一致收敛性和渐近正态性;(3)利用MCMC方法对此估计量进行验证,并通过R软件将上述模型以及参数估计量应用到SHIBOR利率中进行实证研究.     

负二项分布两种参数估计及其比较

负二项分布在昆虫空间分布中有重要应用,其参数常用矩法或零频率法来估计。本文讨论两种估计的性质,得到大样本情形下,零频率较大时,零频率估计较矩估计有更高精度的结论;通过计算机模拟,验证结论。     

Maximum Likelihood Estimation of Hidden Markov Multivariate Normal Distribution Parameters

Hidden Markov model is widely used in statistical modeling of time, space and state transition data. The definition of hidden Markov multivariate normal distribution is given. The principle of using cluster analysis to determine the hidden state of observed variables is introduced. The maximum likelihood estimator of the unknown parameters in the model is derived. The simulated observation data set is used to test the estimation effect and stability of the method. The characteristic is simple classical statistical inference such as cluster analysis and maximum likelihood estimation. The method solves the parameter estimation problem of complex statistical models.     

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??Hidden Markov model is widely used in statistical modeling of time, space and state transition data. The definition of hidden Markov multivariate normal distribution is given. The principle of using cluster analysis to determine the hidden state of observed variables is introduced. The maximum likelihood estimator of the unknown parameters in the model is derived. The simulated observation data set is used to test the estimation effect and stability of the method. The characteristic is simple classical statistical inference such as cluster analysis and maximum likelihood estimation. The method solves the parameter estimation problem of complex statistical models.     

三参数广义帕累托分布的似然矩估计

广义帕累托分布(GPD)在极值统计的POT模型中常常被用来逼近超过阈值u的超出量X_i-u的分布. 为解决经典估计方法存在的问题, Zhang (Zhang J, Likelihood moment estimation for the generalized Pareto distribution, Aust N Z J Stat, 2007, 49:69--77) 对两参数GPD (GP2)提出一种新的估计方法------似然矩估计(LM), 它容易计算且具有较高的渐近有效性. 本文将此方法从两参数的情形推广到三参数GPD (GP3), 结果表明尺度参数和形状参数估计的渐近性质与以上所提到的文章完全相同. 针对GP3的LM估计也具有总是存在、易于计算以及 对绝大多数的形状参数具有接近于最小的偏差和均方误差的特点.     

重尾随机变量和的大偏差

This paper is a further investigation of large deviations for sums of random variables S_n=sum form i=1 to n X_i and S(t)=sum form i=1 to N(t) X_i,(t≥0), where {X_n,n≥1) are independent identically distribution and non-negative random variables, and {N(t),t≥0} is a counting process of non-negative integer-valued random variables, independent of {X_n,n≥1}. In this paper, under the suppose F∈G, which is a bigger heavy-tailed class than C, proved large deviation results for sums of random variables.