查询词典 systematic sampling

Sampling directly at radio frequency in a microwave receiver is impossible up to now because of the limit of today's devices.

对于微波接收机，由于目前器件速度的限制，还无法直接采用射频采样，但若采用中频数字化方案，不仅具有良好的可行性，而且在应用上仍然可以带来许多方便和灵活性。

Several high speed signal processing technologies of wideband digital receivers,including monbit IFM technology,polyphase channelized technology,channelized digital receiver based on FFT and RF bandpass sampling microwave digital receiver,are discussed in detail.

详细讨论了宽带数字接收机的几种高速信号处理技术，包括单比特瞬时测频技术、多相滤波信道化技术、基于FFT的信道化接收机和射频带通采样微波数字接收机，最后提出了在宽带中频数字接收机高速信号处理领域需要深入研究的有关技术。

The basic principle for the layout of GPR survey line was summarized on the three basic operation modes,i.e.,reflection mode,common mid point mode and transillumination mode,and the basic principles for the choice of GPR field operation parameters were introduced,which included the center frequency of antenna,the maximum time window,the spatial and temporal sampling intervals,and the separation 'between' the transmitting and receiving antennas.

概括了探地雷达野外工作的基本方法，介绍了探地雷达现场工作测线布置的基本原则，并总结了探地雷达野外测量时工作参数的选择原则。这些工作参数包括工作天线主频、采样时间窗的大小、空间采样步长、时间采样间隔、天线距大小。

Both are valuable, but if what you want is a sampling of Milhaud's most charming piano music, this is the better choice.

俩个专辑都是瑰宝，但是如果你想欣赏米尤的最具魅力的钢琴曲，这是一个较好的选择。

In this paper, the problem of the transient signal sampling and disposing of three millimeter wave band is systematically investigated.

论文系统的研究了3mm波段瞬态信号的采集及其处理的问题。

The method applies the progressive optimization theory to derive preview control input based on minimalization of performance index of trajectory error area between desired and actual trajectory, the feature of preview control input is that feeback and preview feedforward coefficients are changed in every sampling time.

该方法从目标路径与实际路径之间的面积误差评价函数值最小化观点出发，运用逐次最优化原理来求取最优预见控制输入。

In data space, multi-stage anti-aliasing digital filters are designed on the basis of the Nyquist sampling theorem and the minimax criterion to ensure that the observational data are sampled and stored without distortion.

在数存空间内，依据奈奎斯特定理和最大误差最小化的原则，设计多级抗混叠数字滤波器，使实测数据经过滤波器后，达到无失真抽样与存储的目的。

Therefore, the minimum variance and deviation methodology was introduced, based on which, stratified random sampling technology was used for sample design, and thus making an overall assessment more truly on water quality in distributi.

为此提出以最小方差和偏差的方法论，采用分层随机抽样技术进行样本设计，从而对管网水质进行较为真实的全面评价，同时对影响管网水质的因素进行分析。

Three principles, i.e., minimus, integrated and standard rules, are proposed for studies of the strategy of marine phytoplankton sampling and analysis in China's coastal waters.

中文摘要：从理论上对于海洋浮游植物在生态系统动力学中的监测与调查方法进行初步探讨。

This study was carried out in collective-owned summer grassland in Ganchaitan, which is located at the south foot of eastern Lenglongling Mountain (a branch of north Qilian Mountain), with yak and Tibetan sheep miscellaneously grazed on it. The grassland type could be classified as alpine meadow, dominated by Potentilla froticosa shrub. This study, under grads grazing stress, focused on the community structure, composition, species diversity, above-ground biomass of PFS, by using pane net sampling based on spatial distribution in stead of temporal succession. Results showed that: Grazing stress negatively related to the distance between grazing area and resident area.

以祁连山北支冷龙岭东段南麓的甘柴滩夏季牧场集体长期混合放牧的高寒金露梅Potentilla froticosa灌丛草场为对象，利用空间分布代替时间演替的方法，采用方格网法取样分析调查，对不同放牧压力梯度下金露梅灌丛群落的结构、组成、物种多样性、地上生物量进行研究，结果表明：①放牧居住点由远到近，放牧压力梯度不断增加，金露梅株高、密度、覆盖度、地上生物量和丛间草地的地上生物量均有不同程度的降低，地上的总生物量降低幅度达84.77%。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。