比例抽样

Statistical control of products will be based on attributes, entailing a sampling system ensuring a limit quality corresponding to a probability of acceptance of 5%, with a non-conformity percentage of between 3 and 7%.

产品应依其属性执行统计控制，使抽样系统确保品质差异之接受相当于 5%，不合格比例介于 3%~7%之间。

For fitting ROC curves and getting the area under the ROC curve, we applied the parametric methods of binormal models and ordinal regression models, the semiparametric method of Cox proportional hazards model, the nonparametric methods of Hanley, Delong.

本文采用双正态模型、有序回归模型等参数法，Cox比例风险模型半参数法，Hanley、Delong非参数法拟合了ROC曲线；文中也考虑了样本量的估计、协变量的混杂效应、再抽样技术计算ROC曲线下面积的标准误与可信区间等问题；并研究了SROC分析方法。

METHODS: A total of 1 536 people in rural areas of shaanxi were studied by cluster random sampling methods. All particants were checked by slit lamp, and the people who were more than 50 years old carried out the standard examination by internal criteria. Then they were examined by LOCS Ⅲ in mydriatic situation when there were no contraindication.

遵循按比例、随机、整群抽样的原则对陕西省洋县 1 536人进行白内障患病率的横断面调查，所有受检人员均采用裂隙灯检查晶状体，年龄≥50岁的人，先在小瞳孔下按照国内诊断标准进行检查，如无禁忌再充分散瞳后，按LOCSⅢ标准进行检查。

Methods A Probability Proportionate to Size Sampling was used, and 7913 female sex workers were visited to fill in a questionnaire.

采用按规模大小成比例的概率抽样方法对7913例暗娼进行问卷调查。

Methods The multi stratified grouping random sampling method and the proportional sampling was used.

本次流调方法与全国第四次流调方法基本一致，采用分层整群等比例随机抽样方法。

According to the survey for the whole country to the provinces, autonomous regions and municipalities for the whole meeting, to take layered, multi-stage cluster probability sampling method proportional.

据介绍，这次调查以全国为总体，以各省、自治区、直辖市为次总体，采取分层、多阶段、整群概率比例的抽样方法。

The subjects are 609 students sampled from a junior high school at Taipei County by stratified proportional random sampling method.

本研究以台北县某国中学生为母群体，采分层比例随机抽样方法，抽出样本609人。

To solve the problem of instability when the ratio of samples differ greatly,an improved formula for the method of ratio estimator is put forward by means of clustering,which can reduce the ef.

在抽样技术比例估计与均值估计的基础上，提出了抽样技术的比率估计法，并对其作了详细的分析，同时，通过具体问题的讨论，说明了比率估计法所具有的优越性；针对各个样本比值有比较大的差别时所产生的不稳定性，运用聚类分析的方法提出了具体的比率估计法的改进公式，减少了噪声数据的影响，得到了较高的准确度

Methods The stratified random sampling rule and the standard grading system of blindness set by WHO were adopted in the study, and 11 327 subjects were enrolled (a sampling fraction of 2.01%) in the whole county.

采用分层随机抽样原则，以世界卫生组织盲目分级为标准，对全县按2.01%抽样比例抽取11327例进行盲和低视力的流行病学调查。

There were lesser and fewer in commercial species and its numbers in the cover net, and the sum of Nemipterus virgatus , Saurida tumbil , Upeneus bensasi , Trachinocephalus myops comprised 95.4% in number and 86.0% in weight of sample catch in the cover net,respectively. The high percentage of juvenile commercial species that were undersized in the codend showed 30.3 mm square mesh codend had more serious damage to most juvenile commercial species, approaching or exceeding 50% in percentage of juvenile species which body length is smaller than fishable size- Trichiurus haumela, Priacanthus tayenus , Navodon tessellatus, Argyrosomus argentatus, Nemipterus bathybius and so on, even exceeding 90% in percentage of juvenile Sepia spp, Loligo spp and Parastromateus niger. In particular, 50% selection lengths ( L 0.5) caught Saurida tumbil and Nemipterus virgatus were smaller than their minimum fishable size.

结果表明，这种规格的方目网囊平均尾数逃逸率为29.76%，平均重量逃逸率为8.46%；出现在套网中的经济种类少、数量少，条尾绯鲤、金线鱼、多齿蛇鲻、大头狗母鱼4种鱼的尾数和重量分别占套网抽样渔获的95.4%和86.0%；网囊中带鱼、长尾大眼鲷、黄鳍马面鲀、白姑鱼、深水金线鱼等鱼种的体长小于可捕标准的个体尾数比例均超过或接近50%，枪乌贼、乌贼、乌鲳等幼鱼尾数比例达90%以上，多齿蛇鲻和金线鱼50%选择体长均未达到最低可捕标准，表明该种规格网囊对多数经济种类幼体的损害比较严重。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。