查询词典 sampling methods

Studies on relationship between population size and sampling proportion revealed that population size had evident impact on the sampling proportion and retainment of variations in core collection.

以36对SSR引物的37个位点和2708份核心种质材料进行取样比例的研究结果认为，随着压缩比例的增大压缩群体的基因多样性指数先升高再降低，等位基因的数量和等位基因覆盖率持续下降并且速率逐渐加大。

This board has proper strategy to get the data for power quality analysis, because it uses two chip, six channel analog-to-digital converter and phase locking synchronous technology, which make it able to collect three phase electric voltage and electric current signals in timing sampling and equal-time cycle sampling ways.

并采用了两片六通道高速A/D转换器和运用了锁相同步技术，对三相电压和电流信号能进行定时采样和等间隔采样，这样得到的数据对于下一步电能质量指标进行分析更为合理。

Even when the results under the two sampling systems were similar,typical mode sam- pling saved substantially cost and labor(by 2/5)and time(by 17/20)over random sampling.

即使两种抽样方法结果相近似，但典型众数抽样在布点、经费、人力及时间等方面比随机抽样为少，仅及随机抽样的3/5与3/20。

The system,mainly controlled by the minimum system which consists of the single-chip microcomputer and FPGA,is designed based on the basic principles of digital oscilloscope,which achieves the function of the measured signal's sampling,storages and playbacks of the ordinary oscilloscope,adds the equivalent sampling and sample-and-hold function,which greatly improves the measurement range of the system.

基于数字示波器的基本原理，以单片机和FPGA组成的最小系统为控制核心，实现了普通示波器对被测信号的采样、存储与回放，并且增加了等效采样和采样保持功能，极大地提高了系统的测量范围。

To solve the exsisting problems in the realization of the LFM/CW radar, the thesis presents a technique for dynamically measuring the LFM/CW signals, which can accomplish the dynamic measurements of FM linearity, FM bandwidth and FM slop of the transmitted signals of LFM/CW radars. This technique creates an effective and accurate means of judging the performance of LFMCW radars. The linearity-correction techniques presented in the thesis successfully make the linearity of the transmitted signals of an actual LFM/CW radar reduce from approximately 25% to 0. 1%(or r. m. s linearity of 0.04%), better than the best results (0.22%) obtained by foreign researchers with complex linearization closed-loop in the same kind of LFM/CW radars, according to the published literatures during the last decade. In order to improve the capability of the real-time processing and range-cells management of LFM/CW radars, the principle of equivalent mixing by lacking-sampling process of band-pass real signals is proposed based on the well-proved improvedversion of sampling theorem of band-pass real signals. This principle is used to configure the range-segments processing of the beat signals of an actual LFM/CW radar. The techniques of system-background interference suppression and the beat signal's dynamic range suppression are proposed, and are realized in an actual LFM/CW radar to demonstrate their effectiveness.

针对线性调频连续波雷达实现中急待解决的技术问题，文中提出并验证了线性调频连续波信号的综合动态测试技术，可以完成对线性调频连续波雷达发射信号的扫频线性度、扫频带宽和扫频斜率的综合动态测试，为衡量实际线性调频连续波雷达的系统性能创立了精确有效的测试手段；文中建立的非实时闭环动态校正技术使一部实际的线性调频连续波雷达的发射信号（时带积3×10〓）的扫频线性度从25%改善为0.1%（方均根线性度0.04%），优于国外已公布的80年代同类雷达中采用复杂的实时闭环动态校正环路所获得的实际结果（0.22%）；为了改善线性调频连续波雷达的实时性和分辨单元数处理能力，文中发展完善了实带通信号的采样定理并给予了严格证明，并在此基础上提出了欠采样等效混频原理，将其应用于实际线性调频连续波雷达的距离分段处理中；针对线性调频连续波雷达中系统背景干扰和回波动态范围问题，创立了系统背景综合抑制技术和频域动态范围压缩技术，并将它应用于实孔线性调频连续波雷达系统中，显示出它们的有效性。

An analysis was given for the characteristic time of the mass transport in the sampling system, pointing out the importance of sampling valve resistance and the volume of the gas chamber.

分析了采样系统的响应时间常数，指出进样阀阻力和气室容积对响应时间的重要性。

Investigation on the sampling error of two-component particulate mixture is very essential to the general theory of sampling for chemical analysis.

二元颗粒混合物的随机取样方式有两种：一是按颗粒数目取样，二是按质量取样。

Investigation on the sampling error of two-component Particulate mixture is very essential to the general theory of sampling for chemical analysis.

本文对二元颗粒混合物按质量取样的误差进行了深入研究，详细分析了混合物的各种参数对被测组分含量取样误差的影响，应用MonteCarlo技术对取样进行了模拟。

Survey gain through this project, analysed use double base the RTK measurement technique of station double sampling, the system that can eliminate error of fiducial station coordinate effectively to nod planar coordinate to sampling is affected, disappear weak troposphere changes to be affected to what RTK tall Cheng measures randomly, make RTK planar coordinate measures the need that one class lead measures contented city thereby, make RTK tall Cheng is measured be close to or achieve the 4 precision that wait for leveling.

通过该项目测量成果，分析了采用双基站双采样的RTK测量方法，可有效消除基准站坐标误差对采样点平面坐标的系统影响，消弱对流层随机变化对RTK高程测量的影响，从而使RTK平面坐标测量满足城市一级导线测量的需要，使RTK高程测量接近或达到四等水准测量的精度。

In various embodiments, improved mechanisms for controlling texture sampling are provided that enable 3-D accelerator hardware to greatly increase the level of realism in rendering, including improved mechanisms for (1) motion blur;(2) generating anisotropic surface reflections (3) generating surface self-shadowing (4) ray-cast volumetric sampling (4) self-shadowed volumetric rendering and (5) self-shadowed volumetric ray-casting.

在各个实施例中，提供了用于控制纹理采样的改进的机制，它们能使3-D加速器硬件大大地提高呈现时的逼真度，包括针对下列各项的改进的机制：(1)运动模糊；(2)生成各向异性表面反射；(3)生成表面自投阴影；(4)光线投射容量采样；(4)自投阴影容量呈现和(5)自投阴影容量光线投射。

Many will continue to choose to live in duality and in conflict.

许多人将继续选择活在二元对立性和冲突中。

I find that students of the University of Physical Education all wear sportswear at first sight.

我发现：体育大学的学生乍一看，都是穿运动衣，大家都一样