查询词典 cluster sampling

Cluster sampling When the basic sampling unit in the population is to be found in groups or clusters e.g.

整群抽样一种抽样方法。

A stratified random sampling method, cluster-sampling unit, was adopted to select the required student samples which included 421 students from 14 primary schools, 462 students from 15 junior-high schools, and 623 students from 16 high schools in Kaohsiung, Taiwan.

本研究以分层随机抽样方式选取高雄地区45所学校共1516名学生，包含14所国小共421人、15所国中462A、16所高中623人。

000 People （at the age of 18 -69 ） were investigated through sampling and analyzed by adopting the method of delaminating cluster sampling and the test system on scientific literacy conflated by the Scientific Association of China and the questionnaires.

按照中国科协制定的科学素养测试体系和问卷模式，采取分层抽样方法，对柳州市3000名18岁-69岁公众进行抽样调查。

Methods: Cluster sampling was used in randomly selected individuals (aged ≥ 50 years) in the southern rural area of Heilongjiang. After the pre-experiment uniform standard was completed, 5058 individuals (91%) were received visual acuity test and eye examination. Two consistency tests were successively performed in the two of sampling units during the survey in order to guarantee the quality.

采用整群随机抽样方法将黑龙江省南部农村人口按一定的标准划分成抽样单位，两组人员通过预实验统一标准后对年龄≥50岁共5058人（受检率91%）进行视力和眼部检查，先后在其中的两个抽样单位进行一致性检验。

Coil, Fe, Ni and Zn in spatial variation are identified and the correct assignations are 90.65% for three cluster sites; and (4) based on spatial variations in water quality, it is possible to optimize the monitoring strategy in future with only one of 3 sampling sites and seven discriminant parameters, which can decrease the number of sampling stations and corresponding costs.

coil， Fe， Ni和Zn）可以反映整体水质的空间差异性，且具有90.65%的正确判别能力；④归纳起来，从3类采样点中选择一个或多个、监测7个显著性污染指标即可全面反映后海湾水质管制区的水质空间特征，实现水质监测网络优化。

After the symbol-class accumulation average of every sampling point in all period of time, one time or above symbol-class accumulation average are set on every sampling point in every period of time in multi path searching window, and the result of calculation of all sampling points is stored.

完成所有时段中每个采样点的符号级累加平均运算后，对多径搜索窗口内每个采样点在时间轴上做一次或一次以上的符号级累加平均，并存储所有采样点的计算结果。

Common buckwheat ( F. esculentum ) is an allogamy crop, which is heterogony. There is heterogeneity in the species. To reveal the genetic diversity within cultivar population, In order to explore the sampling strategy that can reveal genetic diversity of buckwheat resources on the molecular level. PCR with intron-splice junction primers and long random primers was employed to reveal the genetic diversity within nine common buckwheat varieties and one tartary buckwheat cultivar population among different individuals. We established the sampling strategy in its genetic diversity study. Then we used the established sampling strategy, and the same PCR markers technique,to analysis the genetic diversity of 86 common buckwheat resources, the main results are as follows

甜荞是花柱异长自交不亲和的异花授粉作物，品种内存在一定的异质性，为了准确揭示甜荞遗传资源的遗传多样性，本研究采用因子分析法对86份甜荞遗传资源农艺性状数据进行分析；采用长随机引物和内含子切接点引物的PCR分子标记技术，对9个甜荞品种和1个苦荞品种不同个体间的遗传多样性进行了分析，建立了甜荞资源遗传多样性研究的取样策略；并利用建立的取样策略，采用PCR标记技术，对这86份甜荞资源的遗传多样性进行了分析，取得如下主要结果

Combined Latin hypercube sampling with antithetic variable method, the method introduces the sampling method into missile accuracy analysis, to decrease sampling numbers and keep simulation precision.

其将拉丁超立方抽样与对偶变数法相结合的抽样方法引入导弹精度分析，保证仿真精度的同时减少抽样次数。

Double channel bandpass sampling method for wide band IF signal is presented to settle the problem of blind zone,which exchanges one more sampling channel for simplification of clock circuit and band pass filter.As a practical reconnaissance receiver, real-time processing performance must be considered.Digital channelizing method lays the base of parallel processing by multi DSP chips and discarding of the redundant data resulting from double channel bandpass sampling.

针对带通采样存在着频率覆盖盲区的问题，提出了宽带中频信号双通道带通采样的方法，通过增加一个采样通道既解决了传统处理盲区方法中设计复杂采样时钟电路、高矩形系数滤波器的困难，还缓解了后续DSP处理压力。

The book is divided into 14 chapters, including Introduction, continuous control system theory, process and discrete sampling, Z transform, sampled-data systems, discrete approximation of continuous system the equivalent, based on mathematical transform the classical design method, based on state space pole placement design methodology, multi-variable system of quadratic optimal control, quantitative effects, the choice of sampling period, the digital control system modeling, digital control system for a variety of design methods, variables quadratic optimal control systems, sampling cycle of selection, non-linear control of the problem, as well as digital control system, a typical application - Disk drive servo control design.

全书共分14章，内容包括概论、连续控制系统理论、采样过程和离散化、Z变换、采样数据系统、连续系统的近似离散等效、基于数学变换的经典设计方法、基于状态空间的极点配置设计方法、多变量系统的二次型最优控制、量化效应、采样周期的选择、数字控制系统的建模问题、数字控制系统的各种设计方法、变量系统的二次型最优控制、采样周期的选择、非线性控制的有关问题，以及数字控制系统的一个典型应用——磁盘驱动器的伺服控制设计等。

Objective:To compare the response control and attention of Schizophrenic patients with that of the healthy controls by Integrated Visual and Auditorycontinuous performance test. To quantitate the impairment of cognitive function in patients, and to explore the relationship between cognitive function and the severity of the disorder.

目的：探讨精神分裂症病人在IVA持续操作测试中的反应控制能力、注意力等，并与健康人进行比较，从而量化精神分裂症病人的认知功能损害，并进一步探讨其认知功能与疾病严重程度的关系。

Main effective factors including subcooling degree, mechanical vibration, gas hydrate reformation, environment temperature, noncondensing gas and surfactant are analyzed.

指出过冷度、机械振动、重复生成水合物、环境温度、不凝性气体、添加剂是影响气体水合物生成的主要因素，还对R152a水合物的放冷进行了实验研究。