查询词典 sampling

We give the approximation formulas of the variance of the sample ratio estimator for a population mean and its asymptotically non-biased estimator in multi-stage sampling.

讨论多阶段抽样比率估计及其样本量选择的问题，给出了比率估计抽样均方误差的近似公式及其渐近无偏估计的公式。

Based on these results,the sampling-rate conversion theory for the FRFT with a rational fraction as conversion factor is deduced.

最后，本文通过仿真对导出的分数阶Fourier域多抽样率理论进行了验证。

In order to characterize the spatial characteristics at different scale, different theoretical model coefficient we defined to create the Kriging map and the rational number of sampling impendent from each other at different spatial scale.

变异函数结构分析显示，土壤机械组成的空间变异在各方向上具有不同变率，但均可通过线性变换而转换为各向同性的统一结构，属于几何各向异性结构；不同观测尺度上有着不同的空间结构特征，对不同空间结构的区域化变量确定了不同的理论模型参数，并绘制克立格图，给出不同观测尺度下满足独立取样的合理取样数目。

Which is the sampling rate of raw data?

原如始数据的采样频率是多少？

Customer orders may take the form of foreign trade companies through the intermediary for the factory or through agents, to carry out sampling, sample and re-sort the order.

客户的定货形式可以通过外贸公司作中介或通过厂方代理，进行选样、来样及复样定货。

For accurate measurement of reactive power in non-sinusoidal circuit, this article introduces a method integrating quasi-synchronous sampling theory with digital-phase-shift network..

在给定定义下，为了准确测量全无功电能，本文介绍了一种结合准同步算法和离散Hilbert的无功测量方法。

After analyzing and comparing two kinds of current control methods of three-phase VSR: indirect current control and direct current control, the author employs the latter as main control scheme, which is to control the phase and amplitude of ac-side current directly, by using dual closed-loop control scheme, through sampling currents of phase a and b and converting them by 3s/2r to get active component and reactive component of ac-side current.

分析比较了三相电压型PWM整流器的两种电流控制方法：间接电流控制和直接电流控制。

With the texture memory spaces, the sampling costs one memory read from the device memory only on a cache miss.

纹理与记忆空间，抽样成本从一读记忆存储装置只有一个缓存小姐。

In this paper,on the basis of theoretically describing mathematics model of the optimum sample plots in certain monitoring area,systematic research and analysis had been carried out through realitic instances and sampling problem of the optimum sample plots had been solved effectively.

该文在理论描述特定监测区域最优样地数学模型的基础上，通过实例进行了系统研究与分析，有效解决了最优样地的抽样问题，所得结果可用于指导生产实践。

The model of the thesis s forecasting method is synthetical use of experience model method and mine-reserach information adding power model method of mineral resources assessment based on GIS. It use several kinds of analysis means for multi-sources data. Firstly the gold-research prospective domains of this area are forecasted through the spatial query and ana-lysis by means of GIS,based on geological and mineral information of thearea, synthesizing geochemistry anomaly information. Gridding inserting value transforms geochemistry data of sampling point of the south of Acixiarega from scattering data to grid data by means of the development of Delphi and Mapobjects, using distance reciprocal inserting value method. After deposit orientation analyse and spatial overlapping analysis by means of CIS, the gold-research prospective domains of the area are forecasted.

本文所建立的预测方法模型是基于GIS矿产资源评价方法的经验模型法及找矿信息加权模型法的综合使用，对多源数据采用多种分析手段，先以研究区1：5万区域地质资料和矿产资料为基础，综合地球化学异常资料，通过Mapgis的空间检索与分析，做出全区成矿有利区分布图；而阿次夏热嘎南部地区离散的采样点的地球化学数据，是采用面向对象编程语言Dephi与GIS控件Mapobjects为开发工具，运用距离倒数插值法进行插值网格化，从而将离散的数据转换为栅格型数据，矿床定位分析、GIS空间迭加分析，预测出该地区成矿有利区。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。