共查询到20条相似文献，搜索用时 31 毫秒
1.
基于错误的先验假定下获得了线性模型下可估函数的Bayes线性无偏估计(BLUE),证明了在均方误差矩阵(HSEH)准则下BLUE相对于广义最小二乘估计(GLSE)的优良性,并导出了它们的相对效率的界,从而获得BLUE的稳健性. 相似文献
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考虑了Gauss—Markov模型中未知参数向量p的最佳线性无偏估计的改进问题,对一般岭估计与BLUE进行了比较,给出了一般岭估计与BLUE的一种新的相对效率e,并导出了e的下界． 相似文献
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赵金凤 《雁北师范学院学报》2010,(6)
讨论了比例可加模型的非参数估计.利用局部线性方法和平均方法给出函数的平均估计,结合回切方法,定义了函数的有效估计,并研究了有效估计的相合性与渐近正态性. 相似文献
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Tenko Raykov 《Structural equation modeling》2013,20(5):750-756
It is shown that the maximum likelihood estimator of the widely used omega coefficient for reliability of multicomponent measuring instruments converges almost surely to the population reliability coefficient for normal congeneric measures with uncorrelated errors as sample size increases indefinitely. This strong consistency implies convergence in probability (consistency) as well as in distribution for the omega estimator. Strong consistency is also demonstrated for the maximal reliability estimator associated with the optimal linear combination of the instrument components. The findings of this note add (i) to the recommendation to use in the general normality case the omega estimator in empirical research, (ii) to the critical literature on the popular coefficient alpha then, and (iii) to the literature on the properties of the optimal linear combination of observed measures and the maximal reliability estimator. 相似文献
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In the nonequivalent groups with anchor test (NEAT) design, the standard error of linear observed‐score equating is commonly estimated by an estimator derived assuming multivariate normality. However, real data are seldom normally distributed, causing this normal estimator to be inconsistent. A general estimator, which does not rely on the normality assumption, would be preferred, because it is asymptotically accurate regardless of the distribution of the data. In this article, an analytical formula for the standard error of linear observed‐score equating, which characterizes the effect of nonnormality, is obtained under elliptical distributions. Using three large‐scale real data sets as the populations, resampling studies are conducted to empirically evaluate the normal and general estimators of the standard error of linear observed‐score equating. The effect of sample size (50, 100, 250, or 500) and equating method (chained linear, Tucker, or Levine observed‐score equating) are examined. Results suggest that the general estimator has smaller bias than the normal estimator in all 36 conditions; it has larger standard error when the sample size is at least 100; and it has smaller root mean squared error in all but one condition. An R program is also provided to facilitate the use of the general estimator. 相似文献
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对一般Gauss-Markov模型在齐次线性估计类中研究了Minimax可容许性,得出了线性Minimax估计在齐次线性估计类中可容许性的充分必要条件,接着对二次损失函数作了一些修改,采用类似齐次线性估计类中Minimax可容许性的研究方法,在非齐次线性估计类中研究了Minimax可容许性,得出了线性Minimax估计在非齐次线性估计类中可容许性的充分必要条件。 相似文献
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时间序列中一种模型的最优预测的研究 总被引：3，自引：2，他引：1
俞泽鹏 《内江师范学院学报》2009,24(8):37-40
给出一种新的带有有色噪声模型,这种新的模型通过转换,应用现代时间序列分析方法,基于ARMA信息模型和白噪声估值器,求出状态的非递推估值器,最后得到新模型统一的、稳态的Kalman估值器． 相似文献
10.
GAO Chao 《重庆大学学报(英文版)》2008,7(2):119-124
A new family of converters, high-performance AC/DC power factor correction （PFC） switching converters with onecycle control technology and active floating-charge technology, was derived and experimentally verified. The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed. Its operating prniciples and control methods were expounded. Based on these, a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein. The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value. 相似文献
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变系数回归模型的参数估计 总被引：2，自引：0，他引：2
讨论了变系数回归模型中变系数的加权最小二乘估计和变系数的加权可估函数的线性估计的最优性;推广了Gauss-Markov定理;并且构造出参数σ2的估计量. 相似文献
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黄莉敏 《中国教育技术装备》2010,(3):38-41
新课程理念的变革,建立了新的教学观、师生观、评价观。与其相对应的教学模式也应随课程理念与教学目标发生深刻的变革。适合地理新课程的教学过程模式应当主要有讨论式、探究式、参与一活动式、角色扮演式。从理论、模式程序、案例和评价几方面进行地理新课程教学过程模式的理论研究与实践探讨。 相似文献
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一般广义岭估计的效率上界 总被引：2，自引：0，他引：2
考察一般Gauss-Markov模型中未知参数向量的最优线性无偏估计的改造问题,讨论了方兴等人提出的最优化无偏估计的一种估计的相对效率,把该文中给出的一般岭估计的相对效率的上界,推广到一般广义岭估计的相对效率的上界.yh 相似文献
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代金辉 《安阳师范学院学报》2007,(5):24-26
本文基于NPME模型提出一个核线性混合效应模型(KLME)估计量。该方法是结合核方法与线性混合效应模型方法得到的。此方法中,组内相关被融合成一种"权",此估计量能够达到很好的渐进有效性,并且在有限样本时更加实用。 相似文献
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李大森 《洛阳师范学院学报》2013,32(2):28-30
本文首先给出了由王松桂等提出的广义谱分解估计(GSDE)的定义,以及由Herderson方法得到的方差分量的方差分析估计(ANOVAE),在此基础上提出了谱和线性混合效应模型的概念,证明了在这类模型中,方差分析估计是广义谱分解估计的一种,并且考察了在一定条件下广义谱分解估计优于方差分析估计的充分条件. 相似文献
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史建红 《吕梁高等专科学校学报》1999,15(4):22-26
本文提出了约束线性模型下回归系统的条件根方估计和广义条件根方估计,证明了在一定的条件下,两者在均方误差意义都能很好地改进回归系数的约束最小二乘估计,并讨论了它们的可容许性及广义条件根方估计中未知参数的选取方法。 相似文献
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本文对文[1]给出的一类半参数广义线性模型(semi-paramctric GLM),利用惩罚似然方法得到参数和非参数函数的惩罚似然估计。同时指出极小惩罚似然估计与惩罚加权最小=乘估计等价。 相似文献
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Chun-yu Li Zhe-wei Wang Can Tu Jia-bo Wang Bing-qian Jiang Qi Li Ling-na Zeng Zhi-jie Ma Ping Zhang Yan-ling Zhao Ya-ming Zhang Dan Yan Rui Tan Xiao-he Xiao 《Journal of Zhejiang University. Science. B》2014,15(10):888-899
Insulin is widely used in treating diabetes, but still needs to be administered by needle injection. This study investigated a new needle-free approach for insulin delivery. A portable powder needleless injection (PNI) device with an automatic mechanical unit was designed. Its efficiency in delivering insulin was evaluated in alloxan-induced diabetic rabbits. The skin irritation caused by the device was investigated and the results were analyzed in relation to aerodynamic parameters. Inorganic salt-carried insulin powders had hypoglycemic effects, while raw insulin powders were not effective when delivered by PNI, indicating that salt carriers play an important role in the delivery of insulin via PNI. The relative delivery efficiency of phosphate-carried insulin powder using the PNI device was 72.25%. A safety assessment test showed that three key factors (gas pressure, cylinder volume, and nozzle distance) were related to the amount of skin irritation caused by the PNI device. Optimized injection conditions caused minimal skin lesions and are safe to use in practice. The results suggest that PNI has promising prospects as a novel technology for delivering insulin and other biological drugs. 相似文献
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Ⅰ型极小值分布样本异常数据的检验 总被引：1，自引：1，他引：0
针对Ⅰ型极小值分布样本的多个异常数据,提出了一种新的检验方法.首先寻找到总体参数的具有较好稳健性的估计量,然后在此基础上构造出检验统计量,进一步求出了该检验统计量精确的概率密度函数和大样本情形下的近似分布.由于检验统计量中的核心统计量——样本分位数,对于异常数据的干扰具有一定的抵抗力,因此利用该方法可以达到有效的检验效果. 相似文献