调整经验欧氏似然及其性质

经验(欧氏)似然是近年来非常流行的非参数统计方法之一,但其存在凸包限制和计算复杂等不足之处.针对此不足,CHEN等人(2008)给出调整经验似然.本文借助此想法,给出调整经验欧氏似然方法,进而讨论其相应的统计性质.理论结果显示,调整经验欧氏似然有与经验欧氏似然完全类似的性质;模拟结果显示,在某些情况下(如二维情况),调整经验(欧氏)似然所得的区间估计具有较好的覆盖率.此外,调整经验欧氏似然的思想和计算都比较简单.从实用角度看,具有较高的推广价值.     

随机右删失数据下半参数线性变换模型的经验似然推断

本文研究了响应变量随机右删失情形下半参数线性变换模型的经验似然推断问题.构造了参数的经验似然比检验统计量,证明了经验似然比检验统计量的渐近分布为加权卡方分布.在此基础上,对经验似然比检验统计量进行了调整,证明了调整的经验似然比检验统计量的渐近分布为标准的卡方分布.基于经验似然和调整的经验似然方法,分别给出了回归参数的一定置信水平的置信域.最后对本文的方法和传统的正态逼近方法进行了模拟比较,模拟结果显示,从置信域的大小和经验覆盖概率两个角度看,本文的方法均比正态逼近方法优越.     

随机右删失数据下半参数线性变换模型的经验似然推断北大核心CSCD

本文研究了响应变量随机右删失情形下半参数线性变换模型的经验似然推断问题.构造了参数的经验似然比检验统计量,证明了经验似然比检验统计量的渐近分布为加权卡方分布.在此基础上,对经验似然比检验统计量进行了调整,证明了调整的经验似然比检验统计量的渐近分布为标准的卡方分布.基于经验似然和调整的经验似然方法,分别给出了回归参数的一定置信水平的置信域.最后对本文的方法和传统的正态逼近方法进行了模拟比较,模拟结果显示,从置信域的大小和经验覆盖概率两个角度看,本文的方法均比正态逼近方法优越.     

线性模型的三种序列相关检验方法对比

研究了在线性模型下,通过经验似然、欧氏似然及V_(T,P)方法分别检验了序列的相关性,并对三种序列相关检验方法做出了对比.同时进一步对三种序列相关性检验方法进行了数值模拟,模拟结果对未来做类似序列相关性检验的研究有着一定的参考意义.     

删失数据下单指标模型的经验似然推断

考虑删失数据下单指标模型, 研究了模型中参数的经验似然推断, 证明了所提出的调整的经验对数似然比渐近于卡方分布, 由此构造相应兴趣参数的置信域. 进一步, 由于模型中参数向量的范数等于1,利用该约束条件来降低参数的维数, 从而增加置信域的精度.模拟研究比较了经验似然方法和正态逼近方法的有限样本性质,从置信域的面积和覆盖概率两方面进行了比较,模拟结果表明经验似然方法优于正态逼近方法.     

含有截断和缺失数据的经验似然推断

本文将经验似然的方法应用到同时包含截断和缺失数据的情况. 通过定义调整后的经验似然比, 证明它服从$\chi^2$分布. 利用随机模拟, 比较经验似然和正态方法的优劣. 结果发现经验似然方法在很多情况下都优于正态方法.     

高斯和非高斯平稳时间序列记忆参数的经验似然检验

本文将经验似然方法运用于高斯的和非高斯的平稳时间序列的长记忆性检验.我们从常用的长记忆模型(ARFIMA)出发,建立了记忆参数的经验似然比检验统计量.从理论上证明了所给的经验似然比渐近服从卡方分布,通过数值模拟和实例分析验证了所给的检验方法对于平稳的ARFIMA模型的长记忆参数检验的有效性.     

重尾序列均值变点的经验似然比检验

本文通过经验似然思想建立假设检验的方法,研究了重尾序列均值变点的检测问题.首先,基于重尾模型,在原假设和备择假设下得到经验似然函数.其次,基于经验似然函数构造似然比检验统计量,并给出在原假设成立时该似然比统计量的渐近分布.最后,进行Monte Carlo数值模拟验证该方法的有效性,模拟结果表明本方法对重尾序列均值变点的...     

相协样本下概率密度函数的调整经验似然推断

本文研究相协样本下概率密度函数的调整经验似然推断,证明对数调整经验似然比统计量服从χ²分布,由此构造了相协样本下概率密度函数的调整经验似然置信区间.在有限样本情况下通过数值模拟,对比分析得到AEL的表现略优于EL和NA的表现.     

广义Lorenz 曲线的非参数统计推断

本文讨论了广义Lorenz 曲线的经验似然统计推断. 在简单随机抽样、分层随机抽样和整群随机抽样下, 本文分别定义了广义Lorenz 坐标的pro le 经验似然比统计量, 得出这些经验似然比的极限分布为带系数的自由度为1 的χ² 分布. 对于整个Lorenz 曲线, 基于经验似然方法类似地得出相应的极限过程. 根据所得的经验似然理论, 本文给出了bootstrap 经验似然置信区间构造方法, 并通过数据模拟, 对新给出的广义Lorenz 坐标的bootstrap 经验似然置信区间与渐近正态置信区间以及bootstrap 置信区间等进行了对比研究. 对整个Lorenz 曲线, 基于经验似然方法对其置信域也进行了模拟研究. 最后我们将所推荐的置信区间应用到实例中.     

Empirical Euclidean likelihood for general estimating equations under association dependence

Empirical Euclidean likelihood for general estimating equations for association dependent processes is investigated. The strong consistency and asymptotic normality of the blockwise maximum empirical Euclidean likelihood estimator are presented. We show that it is more efficient than estimator without blocking. The blockwise empirical Euclidean log-likelihood ratio asymptotically follows a chi-square distribution.     

Balanced augmented jackknife empirical likelihood for two sample <Emphasis Type="Italic">U</Emphasis>-statistics

In this paper, we investigate the two sample U-statistics by jackknife empirical likelihood (JEL), a versatile nonparametric approach. More precisely, we propose the method of balanced augmented jackknife empirical likelihood (BAJEL) by adding two articial points to the original pseudo-value dataset, and we prove that the log likelihood ratio based on the expanded dataset tends to the χ² distribution.     

不等式约束条件下经验似然法在两总体中位数检验中的应用

本文中, Owen 引入的经验似然方法被用于参数空间带不等式约束的两总体中位数的比较. 迄今为止, 还没有人研究过该问题. 这是因为, 在构造经验似然函数过程中所使用的辅助函数不是光滑函数, 因而不是凸函数, 从而使研究难度大大增加. 然而, 通过引入经验过程的办法, 本文很巧妙地解决了此问题. 根据经验过程, 本文证明了两中位数比较的经验似然比检验统计量的极限分布要么是单一的卡方分布, 要么是两个卡方分布的等权混合分布. 这一理论结果得到了模拟运算结果的有力支持.     

含估计参数的加权经验过程

在讨论(广义)非参数似然比拟合优度检验时,加权经验过程理论是一个非常重要的基础.但对含估计参数的加权经验过程理论,目前文献中很少讨论.对含估计参数的加权经验过程的上界型和积分型两种统计量的近似分布进行了讨论,给出了较一般的结果.所得结论叮以为进一步讨论复合零假设下(广义)非参似然比拟合优度检验提供理论基础.     

On Mean Change-Point Detection Based on Empirical Euclidean Likelihood

Mean chage-point detection is the groundwork in statistics. The trimmed empirical Euclidean likelihood ratio function is constructed based on the features of change-point in mean model. And the explicit expression is derived. The null limit distribution of the test statistic is investigated with extreme value distribution. And the change-point detection is made. if the change-point exists, it's location and consistency are discussed. Simulations and real analysis of Nile River data show that our proposed method is practicable and effective.     

Empirical likelihood based goodness-of-fit testing for generalized linear mixed models

In this paper, we propose a bias-corrected empirical likelihood （BCEL） ratio to construct a goodness- of-fit test for generalized linear mixed models. BCEL test maintains the advantage of empirical likelihood that is self scale invariant and then does not involve estimating limiting variance of the test statistic to avoid deteri- orating power of test. Furthermore, the bias correction makes the limit to be a process in which every variable is standard chi-squared. This simple structure of the process enables us to construct a Monte Carlo test proce- dure to approximate the null distribution. Thus, it overcomes a problem we encounter when classical empirical likelihood test is used, as it is asymptotically a functional of Gaussian process plus a normal shift function. The complicated covariance function makes it difficult to employ any approximation for the null distribution. The test is omnibus and power study shows that the test can detect local alternatives approaching the null at parametric rate. Simulations are carried out for illustration and for a comparison with existing method.     

缺失数据均值推断的经验似然方法

研究了缺失数据的均值推断问题.在随机缺失及半参数模型的假设下,设计了基于影响函数理论的经验似然推断方法,证明了所构造的对数经验似然比检验统计量具有非参数Wilks性质.此外,该经验似然方法可以利用辅助协变量中提供的附加信息来提高检验的功效.在近邻备择假设下,计算了检验统计量的功效,并且通过一些模拟考察了该方法在有限样本下的表现.     

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This paper is focused on testing the parameters of the quantile regression models. For complete observation, it is shown in literature that the test statistics, based on empirical likelihood (EL) method and smoothed empirical likelihood (SEL) method, both converge weakly to the standard Chi-square distribution $\chi_M^2$ under the null hypothesis. For right censored data, the statistics in literature, by the EL method, have a weighted Chi-square limiting distribution, but the weights are unknown. In this paper, we show that the statistics based on the EL method and the SEL method also converge weakly to $\chi_M^2$ under the null hypothesis, so there is no need to estimate any weights. As its estimating function is smoothed, the SEL method can be Bartlett corrected. Numerical results show that the SEL method, via Bartlett correction, outperforms some recent methods.     

Empirical likelihood-based subset selection for partially linear autoregressive models

Based on the empirical likelihood method, the subset selection and hypothesis test for parameters in a partially linear autoregressive model are investigated. We show that the empirical log-likelihood ratio at the true parameters converges to the standard chi-square distribution. We then present the definitions of the empirical likelihood-based Bayes information criteria （EBIC） and Akaike information criteria （EAIC）. The results show that EBIC is consistent at selecting subset variables while EAIC is not. Simulation studies demonstrate that the proposed empirical likelihood confidence regions have better coverage probabilities than the least square method, while EBIC has a higher chance to select the true model than EAIC.     

缺失数据均值推断的经验似然方法

研究了缺失数据的均值推断问题.在随机缺失及半参数模型的假设下,设计了基于影响函数理论的经验似然推断方法,证明了所构造的对数经验似然比检验统计量具有非参数Wilks性质.此外,该经验似然方法可以利用辅助协变量中提供的附加信息来提高检验的功效.在近邻备择假设下,计算了检验统计量的功效,并且通过一些模拟考察了该方法在有限样本下的表现.