共查询到19条相似文献,搜索用时 46 毫秒
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本文通过模拟研究,讨论了最大似然方法和Bayes方法在分析结构方程模型中的相似点和不同之处。 相似文献
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多元极值分布参数的最大似然估计与分步估计 总被引:7,自引:0,他引:7
本文考虑多元极值分布的参数估计,给出了分步估计渐近协差阵的近似表示,并对维数P=2,5及相关参数α=0.001,0.01;0.1(0.2),0.9;0.99,0.999的各种组合,计算了分步估计关于最大似然估计的渐近效率,分析了各种参数及维数对渐近效率的影响.分步估计是一种合理、简单而且有较强实用意义的估计方法. 相似文献
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本文基于经验似然方法对AR(p)模型进行统计诊断,文章首先给出p阶自回归模型的广义估计函数并对模型参数进行估计,然后运用数据删失、局部影响分析和伪残差方法对AR(p)模型进行统计诊断,最后通过实证来说明该诊断方法的有效性. 相似文献
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本文应用几何方法研究了协方差结构分析中的拟似然估计.对于该模型引进了对偶几何,在此基础上得到了拟似然估计的二阶渐近性质.通过对偶曲率给出了拟似然估计的偏差、方差和信息损失,并且给出了反映拟观察信息和拟期望信息之间关系的一个极限定理. 相似文献
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本文应用几何方法研究了协方差结构分析中的拟似然估计.对于该模型引进了对偶几何,在此基础上得到了拟似然估计的二阶渐近性质.通过对偶曲率给出了拟似然估计的偏差、方差和信息损失,并且给出了反映拟观察信息和拟期望信息之间关系的一个极限定理 相似文献
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本文讨论了k个独立正态总体的均值和方差同时在简单半序约束下的极大似然估计的求解问题,给出了计算极大估计的迭代算法,且证明该算法收敛。 相似文献
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提出适用于二级与多级评分项目组成的混合测试的加权最大似然潜在特质估计.使用N-R算法获得WML估计,并给出相关方程的详细推导.为探讨WML的性能,进行了模拟研究,所得到的结果表明,WML的估计比最大似然估计(MLE)具有更好的性能.最后,基于一个实际例子对该方法进行了实证研究. 相似文献
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The primary goal of a phase I clinical trial is to find the maximum tolerable dose of a treatment. In this paper, we propose a new stepwise method based on confidence bound and information incorporation to determine the maximum tolerable dose among given dose levels. On the one hand, in order to avoid severe even fatal toxicity to occur and reduce the experimental subjects, the new method is executed from the lowest dose level, and then goes on in a stepwise fashion. On the other hand, in order to improve the accuracy of the recommendation, the final recommendation of the maximum tolerable dose is accomplished through the information incorporation of an additional experimental cohort at the same dose level. Furthermore, empirical simulation results show that the new method has some real advantages in comparison with the modified continual reassessment method. 相似文献
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Jonathan Eckstein Peter L. Hammer Ying Liu Mikhail Nediak Bruno Simeone 《Computational Optimization and Applications》2002,23(3):285-298
Given two finite sets of points X
+ and X
– in
n
, the maximum box problem consists of finding an interval (box) B = {x : l x u} such that B X
– = , and the cardinality of B X
+ is maximized. A simple generalization can be obtained by instead maximizing a weighted sum of the elements of B X
+. While polynomial for any fixed n, the maximum box problem is
-hard in general. We construct an efficient branch-and-bound algorithm for this problem and apply it to a standard problem in data analysis. We test this method on nine data sets, seven of which are drawn from the UCI standard machine learning repository. 相似文献
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对给定的k个正态总体,均值和方差均未知,本文讨论了均值被简单树半序约束,方差被简单半序约束下的保序最大似然估计,并给出了一个求解方法。 相似文献
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关于数据分析方法及SAS软件教学的探索 总被引:1,自引:0,他引:1
陈方樱 《数学的实践与认识》2004,34(1):168-172
论述了在大学本科阶段开设数据分析方法及其应用软件选修课的必要性及可能性 ,并介绍了笔者自 1 996年以来给本校信息与计算科学系三年级本科生开设该课程的情况及收获和体会 . 相似文献
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William Roche 《Acta Analytica》2017,32(4):491-513
Bayesian confirmation theory is rife with confirmation measures. Zalabardo (2009) focuses on the probability difference measure, the probability ratio measure, the likelihood difference measure, and the likelihood ratio measure. He argues that the likelihood ratio measure is adequate, but each of the other three measures is not. He argues for this by setting out three adequacy conditions on confirmation measures and arguing in effect that all of them are met by the likelihood ratio measure but not by any of the other three measures. Glass and McCartney (2015), hereafter “G&M,” accept the conclusion of Zalabardo’s argument along with each of the premises in it. They nonetheless try to improve on Zalabardo’s argument by replacing his third adequacy condition with a weaker condition. They do this because of a worry to the effect that Zalabardo’s third adequacy condition runs counter to the idea behind his first adequacy condition. G&M have in mind confirmation in the sense of increase in probability: the degree to which E confirms H is a matter of the degree to which E increases H’s probability. I call this sense of confirmation “IP.” I set out four ways of precisifying IP. I call them “IP1,” “IP2,” “IP3,” and “IP4.” Each of them is based on the assumption that the degree to which E increases H’s probability is a matter of the distance between p(H | E) and a certain other probability involving H. I then evaluate G&M’s argument (with a minor fix) in light of them. 相似文献
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基于信息熵和回归分析的信用风险评估研究 总被引:3,自引:0,他引:3
信用风险管理一直是银行和其他金融机构最关心的问题之一。本利用信息熵与传统的统计回归对比分析的方法,对信用信息数据库中的逻辑变量进行了数值化处理,在完成属性筛选的基础上,建立多元回归模型来实现对客户特征的评估。实证研究表明,这种数值化的处理方法是可行的,利用该方法评估和预测可能发生的信用风险是有实用价值的。 相似文献