查询词典 unbiased sample

Though the almost unbiased estimator was still a biased estimator, it has smaller bias than corresponding biased estimator.In this paper, we first study the properties of the almost unbiased generalized ridge estimator and the almost unbiased generalized Liu estimator.

但有偏估计毕竟偏离参数的真值，因此学者们又提出了几乎无偏估计的概念，虽然几乎无偏估计仍然是有偏估计，但是它比相应的有偏估计有更小的偏度。

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。

The adjusted R-square is still not an unbiased estimator of the population R-squared, because the ratio of two unbiased estimators is not an unbiased estimator.

调整过的R2仍不是总体R2的一个无偏估计量，因为两个无偏估计量的比例不是一个无偏估计量。

Firstly,the sampling design has great impact on the accuracy of remote sensing classification.There exists great randomicity on the result of points and cluster sample verification on the different Sampling design.On the same sampling design,the stability of point sample verification is higher than that of Cluster sample verification.Secondly,the average accuracy of different sampling designs of multi-point and multi-cluster sample verification can reflect the accuracy characteristic.During the course of point sample verification,stratified sampling's error is lower than others'.During the course of cluster sample verification,systematic sampling and stratified sampling's accuracy are prior to simple random sampling's.

研究结果表明：（1）抽样方式对遥感分类精度评价结果的影响是客观存在的，不同抽样方式下的点样本和群样本检验结果都存在一定的随机性，但同一种抽样方式下，点样本检验精度评估结果的波动幅度小于群样本检验，稳定性比群样本检验要好；（2）不同抽样方式下的多次点样本和群样本检验的平均精度检验结果基本上都能够反映分类图像的精度特征，其中，点样本检验中，分层随机抽样点样本检验效果较好；群样本检验中，系统抽样群样本检验和分层随机抽样群样本检验的效果优于简单随机抽样群样本检验。

Alloy of polyethylene of element of the methodological freeboard that make, titanium and sample of alloy of cobaltic chromic molybdenum, FITC of classics of cuticular grape coccus labels, the cuticular grape coccus that after sample of artificial and articulatory material is disinfected, vaccinal FITC labels, sample surface cent is slick surface and rough surface, every groups each 6 sample, brood the 24 orifice plate that contain bacterium and sample below 37 ℃ after Yo 30min, with fluorescent microscope observation, sample uses observation of scanning report lens.

方法制作超高分子聚乙烯、钛合金和钴铬钼合金试样，表皮葡萄球菌经FITC标记，人工关节材料试样消毒后接种FITC标记的表皮葡萄球菌，试样表面分为光滑表面和粗糙表面，每组各6个试样，将含有细菌和试样的24孔板在37℃下孵育30min后，用荧光显微镜观察，试样用扫描电镜观察。

The results show that the crystal form of the apophyllite sample from Huangshi of Hubei Province is mainly in tabular, and that of the sample from Punna of India is in columnar. The main elements of the both samples are Si, Ca and K, but Al and Na could be found in the sample from Huangshi of Hubei Province. The gas-liquid inclusion is mainly in apophyllite sample from Huangshi of Hubei Province, and the quartz and zeolite inclusions are mainly in the sample from Punna of India.

结果显示，湖北黄石鱼眼石样品的结晶形态以板状为主，印度浦那鱼眼石样品则以柱状为主；所有样品的主要元素均为Si，Ca和K，但湖北黄石鱼眼石样品中还含有Al和Na元素；湖北黄石鱼眼石样品以气液两相包裹体为主，印度浦那鱼眼石样品则以石英、沸石等晶体包裹体为主。

A sequenced method in consideration of the sample range was proposed to rationally array classifiers of a support vector machine with binary tree architecture. A sample distribution radius and a sample distribution distance were introduced to estimate sample range of all classes in high-dimension characteristic space. The classes with bigger sample range were classified earlier in the higher nodal point of the binary tree architecture, and were given wider classificatory areas in the characteristic space.

考虑到样本的分布情况对分类器推广能力具有较大影响，提出一种次序二叉树支持向量机多类算法，采用样本分布半径和样本分布距离估算各个类别的样本在高维特征空间中的分布情况，把分布半径较大的类别或者分布距离较大的类别较早地分出来，并且在特征空间中给其划分较大的分类区域。

We canconsider 29# sample isATP synthase beta chain; The peptides molecularweight of 53# sample are same with that of 43#, 45#, 52# sample and these samples shouldbe same protein, the Mowse score is 78 between 53# sample and Spliceisoform Short, greater than 66 is significant, We can consider 53# sample is Splice isoform Short.

其中，53#样品与Splice isoform Short的匹配分数是78，达到了显著，可以认为53#样品是Splice isoform Short，但根据该蛋白的功能特点，Splice isoform Short对耐盐方面的作用不是太大。

At the same time, we prove that the best linear unbiased prediction of a linear predictable variable Qy and the best linear unbiased prediction βn=(X"sV-1Xs)-1 X"sVs-1ys of regression coefficients of the finite populations βn=(X"V-1X)-1X"V-1y are admissible under matrix loss function and in the class of the linear predictions and the class that contains all predictions, and under quadratic loss function in the class of the linear predictions.

在线性预测类和一切预测类中是可容许预测，而在二次损失函数下其在线性预测类中是可容许预测。

In this paper, three robust estimators: robust best invariant quadratic unbiased estimator, robust minimum norm quadratic unbiased estimator and robust Helmert estimator have been designed. Finally, this paper states that these three classical estimators are particular cases of the RBIQUE.

导出了稳健最优不变二次无偏估计、稳健最小范数二次无偏估计、稳健Helmert估计，并说明了最优不变二次无偏估计、最小范数二次无偏估计以及Helmert估计等均是稳健最优不变二次无偏估计的特例。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。