共查询到19条相似文献,搜索用时 62 毫秒
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对区间删失数据下的Cox比例风险模型,利用极大似然方法得到参数估计量,通过牛顿法和坐标下降法分别求出极大似然估计量的数值解;同时,对两种方法进行实证分析比较,所得结果表明了估计的稳定性与可行性. 相似文献
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基于K型区间删失数据,利用样本空间排序法给出参数优良的置信下限和计算置信下限的递推公式. 相似文献
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在定期随访的医学研究或临床实验中,人们经常会收集到高维区间删失数据,如何对这类数据进行降维是一个非常有意义的问题.本文基于Kolmogorov-Smirnov检验统计量,利用分割和融合的技巧,把独立特征筛选方法推广到区间删失数据中,提出了一种可以处理超高维Ⅱ型区间删失数据且不依赖于任何模型假设的变量筛选方法.此方法的适用范围很广,可以有效地处理各种生存模型下的超高维Ⅱ型区间删失数据,而且可以处理离散型,连续型等多种类型的协变量.在估计生存函数时,本文采用EM-ICM算法,极大地提高了计算效率.大量的数值模拟实验验证了此方法在有限样本下的有效性. 相似文献
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本文针对Weibull分布情形下的Ⅰ型区间删失数据,提出了产品的可靠度的优良的置信下限的理论与计算方法。 相似文献
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当寿命分布是指数分布时本文给出了基于分组数据和双向册失数据平均寿命的近似区间估计方法,所给方法的计算是简单的。 相似文献
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本文考虑基于删失数据的一般回归模型回归系数的方向估计,结合非参数回归和最小一乘方法构造了模型方向的估计,在较为一般的条件下证明了估计量的相合性. 相似文献
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本文用单调叠代方法结合方程的上下解证明了当方程右端满足 Caratheodory 条件时,相应的方程最大、小解仍可以用单调叠代方法求出。 相似文献
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《随机分析与应用》2013,31(1):181-203
Abstract We consider a sequence (Z n ) n≥1 defined by a general multivariate stochastic approximation algorithm and assume that (Z n ) converges to a solution z* almost surely. We establish the compact law of the iterated logarithm for Z n by proving that, with probability one, the limit set of the sequence (Z n ? z*) suitably normalized is an ellipsoid. We also give the law of the iterated logarithm for the l p norms, p ∈ [1, ∞], of (Z n ? z*). 相似文献
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在左截断右删失数据下,我们基于乘积限估计给出了分位密度估计, 获得了分位密度估计及其导数的重对数律。 相似文献
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Jiming Jiang 《Journal of Theoretical Probability》1999,12(1):49-74
We prove some laws of the iterated logarithm for two parameter martingale differences of the following type: E(X
t|(X
s, s
1<t
1 or s
2<t
2))=0 a.s. 相似文献
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Jian-Jian Ren 《Annals of the Institute of Statistical Mathematics》2001,53(3):498-516
We propose a procedure to construct the empirical likelihood ratio confidence interval for the mean using a resampling method. This approach leads to the definition of a likelihood function for censored data, called weighted empirical likelihood function. With the second order expansion of the log likelihood ratio, a weighted empirical likelihood ratio confidence interval for the mean is proposed and shown by simulation studies to have comparable coverage accuracy to alternative methods, including the nonparametric bootstrap-t. The procedures proposed here apply in a unified way to different types of censored data, such as right censored data, doubly censored data and interval censored data, and computationally more efficient than the bootstrap-t method. An example of a set of doubly censored breast cancer data is presented with the application of our methods. 相似文献
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A class of estimators of the mean survival time from interval censored data with application to linear regression 总被引:3,自引:0,他引:3
Zu-kang Zheng 《高校应用数学学报(英文版)》2008,23(4):377-390
A class of estimators of the mean survival time with interval censored data are studied by unbiased transformation method. The estimators are constructed based on the observations to ensure unbiasedness in the sense that the estimators in a certain class have the same expectation as the mean survival time. The estimators have good properties such as strong consistency (with the rate of O(n^-1/1 (log log n)^1/2)) and asymptotic normality. The application to linear regression is considered and the simulation reports are given. 相似文献
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基于EM算法及极大似然法研究了左截断右删失数据下单参数Pareto分布的参数估计,导出其迭代式,并应用随机模拟对参数估计式进行了模拟检验,结果表明迭代式能够快速收敛,EM估计值较为精确. 相似文献
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