排序方式: 共有25条查询结果,搜索用时 15 毫秒
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We propose a new and simple estimating equation for the parameters in median regression models with designed censoring variables, and then apply the empirical log likelihood ratio statistic to construct confidence region for the parameters. The empirical log likelihood ratio statistic is shown to have a standard chi-square distribution, which makes this method easy to implement. At the same time, another empirical log likelihood ratio statistic is proposed based on an existing estimating equation and the limiting distribution of the empirical likelihood ratio statistic is shown to be a sum of weighted chi-square distributions. We compare the performance of the empirical likelihood confidence region based on the new estimating equation, with that based on the existing estimating equation and a normal approximation method by simulation studies. 相似文献
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In this article, we use penalized spline to estimate the hazard function from a set of censored failure time data. A new approach to estimate the amount of smoothing is provided. Under regularity conditions we establish the consistency and the asymptotic normality of the penalized likelihood estimators. Numerical studies and an example are conducted to evaluate the performances of the new procedure. 相似文献
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制导光缆线包光附加损耗分析与计算 总被引:1,自引:0,他引:1
为了求得制导光缆线包的光附加损耗,首先对光缆缠绕时引起的光纤应进行研讨,然后分析微弯应变谱密度,推计计算光附加损耗的公式。计算机模拟验证了计算结果的实用性。 相似文献
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In this article, we use penalized spline to estimate the hazard function from a set of censored failure time data. A new approach to estimate the amount of smoothing is provided. Under regularity conditions we establish the consistency and the asymptotic normality of the penalized likelihood estimators. Numerical studies and an example are conducted to evaluate the performances of the new procedure. 相似文献
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CUI HengjianDepartment of Mathematics Statistical Data Analysis Laboratory Beijing Normal University Beijing China 《中国科学A辑(英文版)》2004,47(1):144-159
The aim of this work is to construct the parameter estimators in the partial linear errors-in-variables (EV) models and explore their asymptotic properties. Unlike other related references, the assumption of known error covariance matrix is removed when the sample can be repeatedly drawn at each designed point from the model. The estimators of interested regression parameters, and the model error variance, as well as the non-parametric function, are constructed. Under some regular conditions, all of the estimators prove strongly consistent. Meanwhile, the asymptotic normality for the estimator of regression parameter is also presented. A simulation study is reported to illustrate our asymptotic results. 相似文献
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1 IntroductionConsider the lnultivariate linear model (MLM) as follows:mX = Z AiBiC E (1)i= 1where X, Ai, Bi and C are p x nfp x qi(qi 5 p), qi x ki and ki x n matrices respectively, Z is ap x p definite positive matrix with p(C1) p 5 n and R(CL) G R(Cfu--,) g' g R(CI), p(.)and R(.) stand for the rank and the colunu spanned linear space Of a matriX respbctively.e = (e1,'2,... f e.), e1le21',f n are iid. p--variate random vectors with D(e1) = Z > 0,E(El) = 0, A: aild C: are … 相似文献
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We have performed ab initio molecular dynamics simulations in conjunction with the multiscale shock technique to study the initial chemical processes of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under shock wave loading. The results show that the initial decomposition of shocked HMX is triggered by the N-O bond breaking and the ring opening. This will initiate many decomposition reactions and lead to the production of many small radicals at a moment. As the shock compression continues, these small radicals recombine to produce many large radicals and further form ring-shaped radicals. Then, these radicals begin to further decompose. It is also found that the system transiently produces a large number of metallic states under the shock compression. Our simulations thus suggest a new mechanism for the initial chemical processes of shocked HMX and provide fundamental insight into the initial mechanism at the atomistic level, which is of important implication for understanding and development of energetic materials. 相似文献
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Hengjian Cui 《中国科学A辑(英文版)》2002,45(5):562-577
This paper addresses the problem of testing goodness-of-fit for several important multivariate distributions: (I) Uniform
distribution on p-dimensional unit sphere; (II) multivariate standard normal distribution; and (III) multivariate normal distribution with
unknown mean vector and covariance matrix. The average projection type weighted Cramér-von Mises test statistic as well as
estimated and weighted Cramér-von Mises statistics for testing distributions (I), (II) and (III) are constructed via integrating
projection direction on the unit sphere, and the asymptotic distributions and the expansions of those test statistics under
the null hypothesis are also obtained. Furthermore, the approach of this paper can be applied to testing goodness-of-fit for
elliptically contoured distributions. 相似文献
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变系数线性EV模型参数的调整加权最小二乘估计及其渐近性质 总被引:2,自引:0,他引:2
研究当结构关系EV(errors-in-variables)模型的系数随某个实变量变化时,如何估计其系数,以及估计的性质如何.采用调整的加权最小二乘方法估计结构关系EV模型的变系数,证明在比较弱的条件下用这种方法得到的估计具有强相合性和渐近正态性,模拟研究表明所提估计性质良好. 相似文献