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；

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。

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。

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.

During future-spot arbitrage analysis, two different types of index replication method including industry stratified sampling and ETF portfolio replication are investigated.

在期现套利研究中，分析了行业分层抽样和ETF基金组合这两种现货指数复制策略。

In this paper, we discussed questions of optimum allocation in stratified sampling with PPS, and given a convenient and effective allocation method for a common model.

讨论了PPS分层抽样时，样本单位数的设计问题。对一种常见模型，给出了一个方便有效的分配规则。

The researchers used a stratified sampling method to ensure diversity.

研究人员使用了分层的抽样方法以确保多样性。

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。

We also proposed a control mechanism for the width of BTP through stratified sampling method.

然后基于自回归模型生成新的草书纹理，并引入分层采样方法来控制纹理宽度；

Methods A stratified sampling study of smoking situation and related factors were conducted among 1560 students in two universities in Wuhu city.

方法采用整群抽样方法抽取芜湖市两所高校大学生1560人进行横断面研究。