查询词典 unbiased estimator

We first state general linear model, ridge-type estimator and general ridge-type estimator, and the constraint biased estimator. And then, we introduce some basic theory about matrix and some conclusion about the admissibility of estimator in Gauss-Markov model. In the third chapter, we discussion several equivalent characterization of the best linear unbiased estimation, we proved that admissible characterization of admissible of linear estimation is as conditional general ridge-type estimation in general linear model. A necessary and sufficient condition that homogeneous linear estimator is admissible estimator is obtained.

本文首先概述了一般线性模型，岭估计及约束岭估计的发展历史和研究现状，在第二章介绍了矩阵的一些基本知识和可容许性的一些基本结论，第三章讨论了一般线性模型最佳线性无偏估计的几个等价条件，以及线性估计的可容许性特征，得到了一般线性模型的可容许线性估计均具有条件广义岭估计的形式，给出了一个齐次线性估计为可容许估计的充分必要条件。

And then some ellipses that AUGR estimator is better than the OLS estimator and AUGL estimator is better than the OLS estimator are given, respectively.Second, the definition of the almost unbiased unified biased estimator is proposed. This definition includes the familiar almost unbiased estimators in literatures, and it is the unified expression of the familiar almost unbiased estimators. Followed the biased and variance are compared of AUUB estimator and the unified biased estimator, respectively. AUUB estimator has smaller bias than UB estimator and the variance of AUUB estimator is between the variance of UB estimator and 4 times of the variance of UB estimator. Finally the properties of AUUB estimator are discussed. The conclusion is gained that there are parameters made AUUB estimator is better than OLS estimator in terms of their mean square error. The sufficient and necessary condition that AUUB estimator is admissible is given. The ellipse is given that AUUB estimator is

然后给出了几乎无偏统一有偏估计的定义，该定义包括了文献中常见的几乎无偏估计，实现了常见几乎无偏估计的统一表达式；接下来我们比较了几乎无偏统一有偏估计与统一有偏估计的偏度与方差，得出了几乎无偏统一有偏估计比统一有偏估计有较小的偏度，几乎无偏统一有偏估计的方差介于统一有偏估计的方差与统一有偏估计的方差的四倍之间的结论；最后我们对统一有偏估计的主要性质作了讨论，证明了存在参数K，S使得几乎无偏统一有偏估计在均方误差意义下优于最小二乘估计的结论，给出了几乎无偏统一有偏估计为可容许估计的充要条件，还给出了在均方误差阵意义下几乎无偏统一有偏估计优于最小二乘估计的椭球。

If Wn is an unbiased estimator ofθand Var → 0 as n→∞, then plim=θ.

如果一个θ的无偏估计量Wn的方差， Var → 0 as n→∞，则， Wn是θ的一致估计量。

These conditions do not relate to the unknown parameters but the dimension of model, so it is easy to apply in practice. Next, we consider the relative efficiency of LSE against the beast linear unbiased estimator.

我们给出了Pitman准则下，最小二乘估计优于Within估计的一个充分条件，最后又得到了广义均方误差意义下两步估计一致的优于Between估计和Within估计的充分条件，并且这些条件只是和模型维数有关而和未知参数无关的一些不等式关系，因此便于实际应用。

In parameter estimation, the Minimum Variance Unbiased Estimator of a parameter θ can be characterized by sufficient statistics and the Rao-Blackwell Theorem.

但匪夷所思的是，有人还再加上"生肖"这样一个中国特有的"统计量"，再对各星座的性格做出统计判断。

The results indicate that if all the investors all full rational,the equilibrium price,whether using close call auction or open call auction,is the unbiased estimator of the risky assets true value.

研究结论表明，若所有的投资者都是理性的，无论采用封闭式集合竞价还是开放式集合竞价，那么均衡价格均是风险资产真实价值的无偏估计量。

The clone programming algorithm has the superior capability in local and global search, and local minimums are refrained efficiently; cross validation has the unbiased estimator property, and therefore, the problems such as over training or insufficient training are avoided.

克隆规划算法是具有局部、全局搜索能力的优化算法，能有效避免陷入局部极值；交叉验证算法的无偏估计性抑制了训练过程中"过拟合"和"欠拟合"。

This paper researches the improvement of the vector of unknown parameter α and the vector of random-effect parameter β, including GLSE and LSE in some conditions, discusses the relevant properties of parameter's estimation, and explains the thought of using its unbiased estimator replaced when the variance is unknown.

本文研究了未知参数向量a和随机系数β的参数估计的改进，包括在一定条件下的GLSE和LSE，并讨论了参数估计的有关性质及说明了在方差未知时，用其无偏估计代替的思想。

Necessary and sufficient conditions for equalities between a 2 y′y and minimum norm quadratic unbiased estimator of variance under the general linear model, where a 2 is a known positive number, are derived.

给出了一般线性模型下方差的最小范数二次无偏估计相等的充要条件，并且当高斯马尔可夫估计与最小二乘估计相等时，获得了一个相对简单的条件，最后给出此条件应用于抽样调查的一个例子。

In this paper,the author analyzes the shortcomings of the traditional method of the sta-tistical treatment of radar data for the accuracy evaluation by flying and derives an unbiased estimator s and its accuracy estimating formula of standard deviation σunder the limited distribution startig from Bessel s formula.

分析了传统雷达精度校飞数据统计处理方法的缺陷，并从Bessel公式出发，导出了σ在极限分布下的无偏估计量S′及其精度估计公式，进而提出了雷达校飞数据统计处理的改进方法，最后给出了一个计算实例。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。