等距抽样

本文采用等距抽样的方法，抽取了341家上市公司。

Systematic sampling is used to get the 341 listed companies as the sample .

二次等距抽样

Systematic sampling on two occasions

我国农产量调查采用的是对称等距抽样设计，它实际上可理解为是一种变形的PPS系统抽样设计，使用的是以播种面积作为辅助变量。

The symmetric and systematic design has been adopted in China Crops Survey , and it is a kind of ( systematic ) PPS sampling design with auxiliary variable , area of crops planted . system ) .

利用Casiofx4500P计算器，设计了3个程序，对林业抽样调查中的等距抽样、二阶抽样、回归抽样进行计算，并在数字实例中应用。

This paper designs three programs with CASIO fx 4500P calculator . These programs calculate equidistant sampling , two strata sampling and regression sampling , then give every program one figure example .

多阶等距抽样下总体总值估计量的方差估计

Estimating Variance of the estimation of the population total in multi-stage systematic Sampling

等距抽样中总体均值的回归估计

Regression estimation of population mean in systematic sampling

二阶段等距抽样

Two - Stage Systematic Sampling

讨论了等距抽样中，如何利用辅助信息改进总体平均值的估计，以达到提高估计精度之目的。

This paper deals with the estimation of population mean in systematic sampling by use of auxiliary information in order to improve the accuracy of the estimate .

第二，在选取数据样本时，我们采用先分层，再等距抽样的方法，选取了数据样本，保证了样本的代表性。

Second , during the process of selecting sample data , we make use of the stratified sampling first , systematic sampling later to ensure representativeness of the sample .

湖南电大开放教育试点专业毕业生追踪调查的抽样遵循随机性、分布相对均匀性、行业代表性等基本原则，采取分层等距抽样的方法。

The sampling design of graduates'tracing survey in Hunan Radio and TV University follows the principles of randomicity , homogeneity and sampling trade representativeness and employs the method of delamination and isometry .

通过等距抽样和实验前测，作者从《英语专业四级词汇选择900题》（华东理工大学出版社）确定出三组同义词作为实验目标词。

In the present study , three pairs of synonyms are selected carefully by the systematic random sampling from 900 lexical practices for TEM-4 ( East China University of Science and Technology Press ) .

利用等距抽样检测数据，通过多元线性回归分析，建立了缸体垂直度误差相对于刀具加工件数的定量关系式，实现了根据垂直度误差值确定刀具具体加工件数，从而准确预测了换刀周期。

Based on multiple linear regression analysis and equidistant stratified sampling datum , the quantitative relationship formula of perpendicularity error about machining workpiece numbers is established to determine workpiece numbers and predict tool change cycle .

文章提出了一种改进的随机抽样算法，对其时间和空间复杂性进行了分析，结果表明改进的随机抽样算法总体性能优于现有随机抽样算法，最后，给出了改进算法在等距抽样中的应用。

And the time and spatial complexity of the proposed algorithm is analyzed . The results show that the improved algorithm is better than the existing random sampling algorithm . Finally the application of the improved algorithm in isometry sampling is given .

结果经过整群等距随机抽样，从陕西省抽样180个调查小区，调查42833人，发现40例白癜风患者，白癜风患病率为0.093%。

Results Forty vitiligo patients were found out of 42 833 people surveyed .

将精神分裂症致残情况按等距机械抽样的原则每10人抽取1人进行残疾评定。

One of 10 schizophrenics were assessed for disability due to schizophrenia according to isometric mechanical sampling .