查询词典 sample size

The effects on core collection development with different sample proportionsDuring core collection development a difficult task comes when attempting to reduce the sample size of a large collection without losing its diversity.

不同聚类方法和取样策略的评价聚类方法与核心库的构建有着密切关系，不同的聚类方法对稻米品质性状核心种质的构建可以产生不同影响。

The probability to commit error is less thanα+2β×0.01. For enumeration data:According to the practical sample size and the relative magnitude between two sample proportions,a user can make an equivalence conclusion if the P value of difference test is equal to or larger than P_listed in the forms.

对于计数资料，用户可根据实际所用样本量、由试验结果所求出两样本率之间的相对大小关系以及差异性检验P值查表，若大于等于表中的P_，则可下等效性结论，犯错概率小于α+2β×0.01。

The main work of this thesis is simulation study on the basis of large sample properties for two estimates by Monte Carlo method with some models. We consider the problem of the choice of window width, consistent rate and some doubtful points about consistent rate with fixed sample size.

本文的主要工作是依据大样本性质，对特定模型的这两种估计用Monte Carlo方法进行了模拟试验，讨论了长度有限的样本情况下窗宽的选择问题，比较了两种估计的拟合程度，相合速度并提出了对相合速度的一些疑难点。

Although the process for calculating the optimal fixed sample size is quite simple, it doesn't stop unless the last sample collected. So it has the property of the fixed overall cost.

最佳固定抽样个数法虽然计算简易，但无提早停止抽样的特性，即有固定成本性质。

Holliday acknowledged limitations of the study, including the small sample size, the use of a convenience sample, and reliance on only men for the study.

Holliday承认这次试验的缺陷，包括样本太小，没有按随机原则而只选方便的样本，只研究了男性患者。

At the beginning, an engineering method called semi-empirical reliability estimation method is introduced. Then, a detailed introduction of the bootstrap method, which has been widely applied to small sample reliability assessing since it was proposed in 1979, is made immediately. At last, a promoted virtual sample expanding method, that the reliability test sample size is expanded from 2-3 to 10, is proposed on the basis of predecessors research results. And the new method associated with bootstrap method is used to assess the test life lower limit in the case of logarithmic normal distribution.

首先阐述了处理极小子样可靠性评估问题较合理的一种工程处理方法—半经验可靠性评估方法，随后详细介绍了近年来在小子样可靠性评估领域发展迅速的Bootstrap方法，最后在前人研究成果的基础上提出了将样本数从n=2～3虚拟增广至n=10的虚拟增广样本推广方法，将该方法应用于服从对数正态分布的寿命总体，利用Bootstrap方法得到了试验寿命下限的估计，并与已有的半经验可靠性评估方法的结果作了比较分析。

Unlike unbiasedness―which is a feature of an estimator for a given sample size―consistency involves the behavior of the sampling distribution of the estimator as the sample size n gets large.

无偏性是，给定样本容量n下，估计量的性质；一致性则是，当样本容量n变大时，估计量的样本分布的变化特征。

Fisher criterion assumes that each sample has a unimodal,symmetric distribution for each class.However,when the training sample size is large and their distributions are multimodal or skewed,the definition of classical Fisher criterion can not correctly reflect the distribution of the data in the sample space,in that case,the sets of discriminant vectors are not optimal virtually.

Fisher准则函数的前提条件就是假设每类样本数据满足单峰高斯分布，即各类样本在模式空间的分布近似椭球状，但是当训练样本数据较多且呈多峰分布时，传统的Fisher准则函数并不能准确反映样本数据的分布，显然基于Fisher准则函数的线性判别分析得到的最优判别矢量集也不是最优的。

First, the least sample size for high reliability aviatic mechanical products in common experiment is calculated. And then the reason for performing small sample and extreme small sample test is discussed.

首先阐述了航空领域机械类高可靠性产品在常规可靠性试验时所需要最小子样数的确定方法，接着阐述了被迫采用小子样、极小子样可靠性试验的原因。

It noted that "a total of 3498 polling stations are covered by the ECC's order out of which a sample size of approximately 10% was randomly selected. The sample size now contains 358 ballot boxes."

公报说，3498个投票站存在舞弊嫌疑，而选举委员会将对其中的约10%，也就是对358个投票箱的选票进行取样审核并重新计算。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。