查询词典 sample size

For fitting ROC curves and getting the area under the ROC curve, we applied the parametric methods of binormal models and ordinal regression models, the semiparametric method of Cox proportional hazards model, the nonparametric methods of Hanley, Delong This paper also include estimation of required sample size, evaluation of confounding effects, and estimation of standard error and confidence interval by resampling method for ROC analysis.

目前该模型用于ROC分析的统计学方法比较完善，属于"经典"的ROC分析参数法。本文探讨了单变量、双变量双正态ROC模型的构建及其参数的最大似然估计方法；采用双变量卡方检验、真阳性率z检验、面积z检验三种方法比较了ROC曲线间是否具有显著性差异。

He was quick to offer a caveat, however: This is all based on a relatively small sample size.

但他马上做出说明以防止被误解。这些研究都是以相对较小的样本量为基础的。

Meanwhile, it could be seen that there does not exist a confidence interval with width less than 0.5 because of the property of Poisson distribution. Based on these conditions, the author mainly carried out research into two aspects of this problem as follows. Firstly, by numerical and theoretical analysis, the author compares some existent confidence intervals, for example,"exact" confidence interval, Wald confidence interval and Bayesian confidence interval, and finds some deficiencies points of the confidence intervals, whose modification version has been proposed .Also, several better confidence intervals such asare also presented .Secondly, for given confidence coefficient and interval width, the author constructs a class of asymptotical two-stage interval estimate procedures. At the same time, under varies restriction of confidence coefflcientent interval width, the optional sample size of the first stage has been computed by numerical computation. The numerical computation shows that the method considered in this dissertation have good properties and applied value.

同时，由于Poisson分布的特性，我们知道不存在其参数区间长度小于0.5的置信区间，基于这些情况，我们主要展开了以下两个方面的研究：一是利用数值计算分析与理论分析的方法对现有的若干置信区间如"精确"置信区间，Wald置信区间，Bayes置信区间等进行分析比较，发现了一些缺陷，针对这些缺陷，我们进行适当的修正，并得到几种性质较好的置信区间如：修正大样本区间Jeffreys原则下置信区间二是针对已给定的置信系数与区间长度，我们提出了一种渐近的两阶段区间估计程序，并利用数值计算的方法，在各种置信系数与区间长度限定下，算出了最优的第一阶段观测次数，大量数据表明，本文考虑的方法性态良好，具有应用价值。

But under limited training sample size, increased dimension of remote sensing data means decreased samples/dimension ratio, which can lead to low classification accuracy if common statistic based pattern classification methods were used.

但在有限训练样本条件下，遥感数据维数的增高使样本/维数比率大大降低，采用常规的统计模式识别方法反而无法得到较好的分类结果。

This approach not only avoided face information missing, increased the number of composite feature, but also avoided the small sample size problem in theory.

这种方法在避免图像信息的丢失、增加组合特征的同时，理论上也能避免单纯使用线性判别分析进行特征抽取时容易出现的小样本问题。

A new computational formula of fiducial probability in consideration of sample size and subsample standard deviation is derived from the least squares principle.

利用最小二乘原理，推导出考虑样本容量和子样标准差的求解置信概率的函数，继而确定数据的置信区间，对数据进行筛选。

Weibull distribution is widely used as a life distribution, and estimating lower confidence limit of reliability is important. But so far this problem has not been well solved if when the sample size is small.

威布尔分布是使用非常广泛的寿命分布，关于威布尔分布的可靠度的下限估计是一个有重要意义的问题，文献中有很多讨论，但当样本量较小时，关于二参数威布尔分布的可靠度的下限估计至今没有非常有效的方法。

In theory the coverage error is of order On~(-1,where n is the sample size,however simulation indicates that an EL based confidence region with nominal level 90%may have coverage probability as low as 83%.

理论上覆盖误差是On~(-1，这里n是样本大小，不过模拟显示一个名义置信水平是90%的经验似然置信域可能只有低到83%的真实覆盖率。

Therefore, in order to study pharmacology of astragali, atractylodes macrocephala and licorice root active component infurther step, search for reasonable extraction technology of effective parts, develop safe and reliable,exact curative effect new drug for treating UC fit to clinic, we plan to use advanced colon-target andadhesion releasing technology to make up complex prescription colon-target capsule preparation ofabove-mentioned three effective parts. This will have important significance for developing new drugstudy on treating UC with TCM.Study method1. pharmaceutical research1.1 study on extraction and abstraction technology of Astragalus mongholicus saponinAdopt ethanol backstreaming to extract Astragalus mongholicus saponin, compare extraction percentage of different concentration ethanol. Adopt resin adsorptive process to depurate it, inspect resin dynamic adsorption curve, sample size, concentration and dosage of eluting ethanol and concentration of eluting lye and so on technology parameter. Determine the best extraction and abstraction technology.

目前国内外未见有治疗该病的中药有效部位的复方制剂，因此，为进一步研究黄芪、白术和甘草有效成分的药理学作用，探索合理的有效部位提取工艺，开发适合于临床的安全可靠，疗效确切的治疗UC的中药新药，我们拟采用先进的结肠靶向定位及黏附释药技术，将黄芪、白术和甘草的上述三类有效部位制成复方结肠溶胶囊制剂，对于开展中医药治疗溃疡性结肠炎的新药研究具有重要意义。

Because guidance ammunition is expensive and the destructibility is inevitable in the testing , the sample size is small .

由于弹药的高价值以及试验的破坏性，使得只能进行小样本试验。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。