样本标准差

论述采用合并样本标准差和B类不确定度评定方法计算重复性引起的不确定度，使可以在符合检定规将规定的较少测量次数中得到比较可靠的标准不确定度。

Using the method of merging sample standard deviation and evaluating indeterminacy of category B to calculate the indeterminacy aroused by repetitiveness can obtain reliable standard indeterminacy in much less time tallied with the inspection procedure .

方法：分析样品中菌落总数不确定度的来源，采用合并样本标准差的方法来评定菌落总数的不确定度。

Methods : The source of measurement uncertainty of the colony determination in fishmeal was analyzed and the method of uniting standard deviation was applied to determine the uncertainty of the colony .

该算法以小波子带图像样本标准差为选择量化编码阈值的重要依据。

In this algorithm , we selected the sample-standard-deviation as the key quantization threshold in every wavelet subimage .

为了使所有这些曲线具有可比性，汉森博士将实际偏差值用其与所属样本标准差的比例来衡量，用数据发生偏差数与数据总数的比例表述其频率。

To make all the curves comparable , he expressed the values of the actual deviations as fractions of a standard deviation , and their frequencies as proportions of their total number .

理论和实验表明：随着序列长度增加，预测准确率的提高等价于正态分布样本标准差估计的置信区间随样本容量的变化，它按照卡方分布方式提高。

The theory and results of the experiments showed that as the length of the series grows , the accuracy of forecasting grows as that the standard deviation estimation of confidence interval grows with the increase of number of the samples according to χ 2 distribution .

计算每组样本的均值±标准差（x±s），进行成组设计材料的t检验。

Mean and standard deviation ( x ± s ) were calculated .