查询词典 stratified sampling

In this paper, the regression estimation for multivariate simple random sampling and stratified sampling is discussed, it is proved that this method is more available than the estimation without auxiliary variable, and some statistical inferences of population mean are given.

文章系统地讨论了多元简单随机抽样及分层抽样的回归估计法，说明与无辅助信息抽样相比，回归估计法是一种更有效的方法，并得出了总体均值的一些统计推断。

Methods The study was conducted by cluster sampling and stratified sampling.

采用整群抽样和分层抽样相结合的调查方法。

The main research and application result is: five dynamic sampling frames with spatial autocorrelation analysis are achieved such as high-high, low-low, high-low, low-high and not significant, and finally the result of per capita agricultural total output value of Beijing with spatial stratified sampling technique is 35.80 thousand Yuan RMB, with the sampling error range is ±3.861 thousand Yuan RMB.

其结果为：动态生成"高－高集聚"、"低－低集聚"、"高－低集聚"、"低－高集聚"和"分布不明显"5个抽样框，并最终通过空间分层抽样流程得到北京市人均农业总产值的抽样调查结果为3.580万元，抽样误差的允许范围为±0.3861万元。

The survey conducted in Taiwan was designed using a multiple-stage sampling method that utilized the principles of probabilities proportional to size, stratified sampling, and systematic sampling to strengthen the sample's effective representation.

为符合研究的需要，本次研究的抽样方法采取较复杂的多阶段抽样法，主要应用「抽取率与单位大小成比例」原则，结合分层抽样、等距抽样等抽样方法的优点，以求提高样本代表性。

Applying mathematical statistics, this paper studied the characters of random sampling and its excessive random effect on other trip characters, put forward stratified sampling method, researched quota sampling and best distribution sampling.

建议对于大型城市采用简单随机抽样方法；而对于中小城市，按年龄分类，采用分层抽样方法，以提高调查精度。

Excepting the conventional methods of surveying samples, such as simple random sampling, stratified sampling, cluster sampling, systematic sampling, liner regression sampling, ratio estimator, two-stage sampling, double sampling, rotate sampling, non-probability sampling, there is sequential sampling and mark-recapture, particularly mark-recapture was introduced in detail.

针对生物资源的调查，除了一般抽样方法如：简单随机抽样、分层抽样、整群抽样、系统抽样、双重抽样、二阶抽样、样本轮换、比率估计、线性回归抽样和不等概抽样，还有序贯抽样和标记-重捕获方法，这里特别详细介绍了标记-重捕获方法。

Methods The integration of simple random sampling and stratified sampling was adopted to select 480 soldiers of 5 different branches of the military forces stationed in Jinan as study objects.

采用简单随机抽样和分层抽样相结合的方法抽取驻济5个兵种不同的部队，计480名军人作为研究对象。

Consequently, investigated in detail are several concrete complementing schemes based on simple random sampling, stratified sampling.

摘要本文研究了不放回追加策略，包括基本设计和域追加设计都为简单随机抽样、分层随机抽样情形下不放回样本追加时域的估计的问题。

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。

At present,the methods of random sampling,systematic sampling and stratified sampling are widely used in remote sensing sampling.

目前，随机抽样、系统抽样和分层抽样方式在遥感抽样调查技术领域应用比较广泛。

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。