1·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。
2·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。
3·Methods: The stratified sampling and cluster random sampling methods are used in this survey.
方法：本研究采用分层随机抽样方法和整群随机抽样方法。
4·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。
5·Methods A large-scale survey was conducted at 250 medical health units based on stratified sampling.
方法使用分层抽样的方法在全国范围内抽取250家医疗机构开展大规模调查。
6·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。
7·Methods Middle School students in Jiangsu Rural Areas were investigated with SCL-90 by stratified sampling.
方法随机分层整群抽样的方法，应用症状自评量表（SCL-90）对江苏省农村中学进行调查测评。
8·This theory was verified by the experiment of stratified sampling for chemical analysis of silicon carbide material.
应用碳化硅物料的分层取样实验对该理论进行了验证，提出了最佳取样方案。
9·As the sampling survey is stratified sampling, so the research of the sample rotation is under the stratified sampling.
由于该抽样调查采取的是分层抽样，因此相应地用分层抽样下的样本轮换研究。
10·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。