抽样

Objective:This paper proposes an iterative noncentral procedure for the sample size determination in log rank test and compares it with the LachinFoulkes procedure. Methods: Samplings are performed with a prescribed size.

本研究首先按临床数据实际分析过程说明设计参数赋值依据和生存研究所需样本量测定原则，然后提出迭代非中心法，即借助重复抽样估计其非中心参数，测定所需样本量，并同基于指数分布的方法进行比较。

The purpose of this study was to investigate the sampling distribution of the stress values yielded by Kruskal's nonmetric multidimensional scaling procedure.

本研究旨在调查非计量多向度量尺法之适合度统计数──压力系数的实徵抽样分配。

Results Risk for lung cancer caused by exposure to nitrosoamine increased significantly after adjustment of nonoccupational risk factors (RR=271,with 95% CI of 132 to 557),with a significant doseresponse relationship between exposure to nitrosoamine and lung cancer.

结论（1）本文数据提示病例－队列分析因标准误较小、抽样更简便而优于巢式病例－对照研究方法；（2）亚硝胺暴露与肺癌之间有较确定的关系，但受到吸烟和经济状况等因素作用的修饰，需进一步研究

First, the survey process, including the sampling procedure and design of the survey questionnaire, increases the risk that the survey will collect nonrepresentative data from the survey population, thereby limiting the overall representativeness of the resulting survey data.

首先，调查过程，包括抽样程序和设计的调查问卷，增加了风险，这项调查将收集数据nonrepresentative从调查的人口，从而限制了整体的代表性，由此产生的调查数据。

By utilizing the theory of numerical processing, digital frequency spectrum analysis and multi-rate digital signal processing, this paper focuses the research on mechanism of the testing error, the compensation of testing error in the field of sampling technology, nonsynchronous sampling, nonuniformly sampling, and puts forward some new analyzing, compensation and realization methods.

本论文通过运用数值处理、数字频谱分析和多抽样率信号处理的有关理论和原理，对采样技术、采样的非同步方式和采样的多通道方式中的测试原理、测试误差产生机理、测试误差补偿及其应用技术等主要环节进行了深入的研究，提出了一些新的分析与处理方法，建立了有关测试误差分析与补偿的预估理论和实现方法。

The Tuhai Rivers water is not suitable for water source for its serious pollution, four-grade water quality,overproof 80 times of COD.

近年来，徒骇河水污染已十分严重，据抽样化验，水质为四级，COD超标80倍，故不能将徒骇河水作为水源。

Results The rates of awareness about avian influenza and its infection sources were 99.0% and 83.8%,respectively;The rates of awareness about route of transmission of contact transmission,airborne infection,dungwatermouth and insect vector were 78.5%,71.2%,54.5%,70.2%,respectively;There were 45.5% people who thought all people could be infected easily by avian influenza virus;79.1% people thought fever was clinical situation of avian influenza,and that was 52.9% for nose running,cough,pharyngalgia.

采用分层整群随机抽样方法抽取顺义区禽流感高危险职业从业人员191名，进行禽流感有关知识、信念和行为的问卷调查。

In addressing the heterogeneity factor, this paper will use Logistic regression, the Beta-binomial model the Williams method arid GLMM to analyze the secondary data collected at the incidence of Downy mildew on grapes and Phomopsis leaf blight on strawberrys. Also, there will he a thorough discussion on the advantages and disadvantages among the different model approaches according to -2 Res Log Likelihood, AIC, BIC and residual plots.

本研究旨在探讨病害发生率的研究中，以层次取样法进行抽样，并以实际资料葡萄露菌病和草莓叶枯病的病害发生率为例，藉由计算离势参数、-2 Res Log Likelihood、AIC、BIC和绘制残差图，比较逻辑斯回归、贝他－二项模式、威廉斯模式与广义线性混合模式四种模式对资料进行配适情形，来探讨这些方法克服过度离势的能力并比较其优劣。

Phytosociological description of vegetation has always been found on field sampling alternating with studies of the releves at home.

植被的群落学描述已经常以野外抽样为基础来取代室内样地记录的研究。

A direct sample method has been used to simulate the discrete polydisperse Mie phase functions of haze aerosol.

提出了一种直接随机抽样拟合散射相函数的方法。

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。