the population is divided into subpopulations (strata) and random samples are taken of each stratum

the influencing factors of feat technique in hygiene were investigated in sichuan with the method of the stratified sampling and the categorical data analysis.

采用分层抽样方法和分类资料统计方法，开展四川省农村卫生适宜技术推广影响因素调查研究。

methods multistage sampling and stratified sampling were used and information was gathered by interview with questionnaires.

方法采用分层多阶段随机抽样法，获取样本。 并采取问卷的形式进行调查。

stratified sampling can reduce the sampling error associated with simple random samples.

分层抽样可以减少由简单随机抽样造成的抽样误差。

method stratified sampling method, 4185 women from the community in different physiological period, 660 women were randomly selected for the survey.

方法采取分层抽样的方法，从社区4185名妇女中按不同生理时期，随机抽出660名妇女作为调查对象。

methods:with the method of stratified sampling the original data of first pages of 667 case records in 7 hospitals were surveyed.

方法：采用分层抽样方法，对7所医院6 6 7份病案首页数据与原始病历数据进行调查复核。

methods stratified sampling methods were used to carry out the prevalence study of maternity and child care for women at child bearing-age in luochuan county and bin county.

方法采用分层抽样，抽取洛川、彬县育龄妇女入户进行妇幼保健现状问卷调查。

stratified sampling method was applied to investigate immunization status of ecdemic children and its affecting factors in baoshan district.

方法采用分层抽样方法对本区外来流动儿童免疫接种现状及其影响因素进行流行病学调查。

in this study, stratified sampling is used to select samples in gansu province.

本研究采用分层抽样的方法，在甘肃省四个县进行调查和分析。

inaccuracies in the present proportionate stratified sampling algorithm based on fuzzy failure rate data is one main cause which makes the testability demonstration results untrustworthy.

现有的分层抽样算法中故障率数据不準确是导致测试性验证试验结果不可信的一个原因。

sample papers on data flow, including density-based sampling, stratified sampling and other dynamic.

关于数据流抽样的论文，包括基于密度的抽样，动态分层抽样等。

this paper introduced several methods about the concrete strength inspection: the sampling method given by the present specification; simple random sampling without replacement; stratified sampling .

具体介绍了砼强度检测抽样的几种方法：现行规程抽样法；简单随机抽样法；分层抽样法。

it is necessity that stratified sampling is used to investigate to the trees and the new stumps, and the spatial distributing pattern of the red turpentine beetles was negative binomial distribution.

红脂大小蠹寄生的树木和新伐桩有分层抽样的必要及其空间分布格局经拟合为负二项聚集分布。

we then collected samples of soils and sediments for analysis at random points within ecotope features selected by a regionally-weighted stratified sampling design.

依据区域权重分层取样设计方法，在生态立地斑块中随机设定取样点进行土壤和淤泥取样；

method stratified sampling was used in this study, and a self-administered questionnaire was conducted for data collection of personal health status and hospitalizing behavior.

方法采用自行设计的中老年人就医现状调查问卷对唐山城市与农村中老年人进行分层抽样调查。

as a common sampling method in modern statistics, stratified sampling attracts much attention in practice. it has higher sampling precision than random sampling.

分层抽样作为现代统计方法中最常用的抽样组织形式，已在实践中受到主管广泛重视，它比纯随机抽样具有更高的抽样精度。

the equivalence of simple stratified sampling with multi indexes to multi stratified sampling with single index is shown.

证明了单指标的多次分层抽样率的估计和误差计算与按多指标的一次分层抽样率的估计和误差计算等价；

face to face interview was carried out during the optimum allocation random stratified sampling survey process.

最优分配随机分层抽样方法则采用访谈，获得数据。

methods with stratified sampling and cluster sampling, we investigate 487 families in poverty.

方法采用分层整群抽样方法调查487户贫困家庭。

methods an investigation was made by cluster and stratified sampling method.

方法采用多阶段分层整群抽样方法入户调查。

we had applied methods of stratified sampling and simple random sampling and collected 1 704 questionnaires in 21 various hospitals, 18 provinces, then analyzed them.

在全国不同区域，选取18个省市的21家医院，采用分层抽样和简单随机抽样相结合的方法，收集调查问卷1704份，进行统计分析。

a method named mixed two-phase stratified sampling is firstly put forward, and how to use it in market research is also analyzed.

提出了一种叫做混合双重分层抽样的方法，描述了怎样将它用到市场调研中去；

stratified sampling method, from a polytechnic school in qingdao test samples were 850, 809 valid questionnaires were valid for the 95.18 percent response rate.

采取分层抽样法，从青岛某理工院校抽取被试850名，收归有效问卷809份，有效问卷归收率为95.18%。

stratification is one of the key techniques in stratified sampling investigation and monitoring using remotely sensed data.

分层技术是遥感分层抽样调查与监测方法中的关键技术之一。