查询词典 sampling method

By constructing the piecewise linear function from samples, it is able to approximate the measured metric more precisely. Compared with current popular sampling algorithms, FASM algorithm can provide more precise estimation of metric under the same samples. In the condition of retaining the same approximation errors, our adaptive sampling methodology only requires fewer samples, which will save sampling costs considerably during sampling process.

与当前常用的抽样算法相比，在采集相同的样本数量情况下，本文的拟合模型对指标进行的估计更准确、稳定；而在保持相同的拟合误差时，自适应抽样算法则可显著减少所需采集的样本数量，节约数据采集过程的代价。

The definition of Halton points is introduced and the algorithm complexity is analyzed, then the sampling strategy of triangle plane is introduced, including geometry region partitioning, coordinate mapping between triangle plane and rectangle plane, and computing principle to the coordinates of sampling point. The experiment results compared with Jittered sampling and improved LHS sampling are given.

给出了Halton点的定义，分析了其算法复杂度，在此基础上给出了三角平面的采样策略，包括几何区域的划分、三角平面与矩形平面的坐标映射、采样点坐标计算原理；并将该方法与Jittered采样法、改进的LHS采样法进行了比较。

The main work of this paper is to study the sampling theorem in domain of the fraction and the sampling relationship. We will try to obtain the theoretic sampling rate and the proof of feasibility. And we also give some relationship between the kernels under the meaning of sampling.

本文的主要工作就是，研究了分数傅立叶变换算子核函数的采样定理及采样关系，给出了一种能够达到理论的最佳采样频率的尝试，也给出了这种做法的可行性的证明，更进一步由采样关系给出了核函数的一些关系。

At present,the methods of random sampling,systematic sampling and stratified sampling are widely used in remote sensing sampling.

目前，随机抽样、系统抽样和分层抽样方式在遥感抽样调查技术领域应用比较广泛。

Main points of the thesis are as follows:(1) The main function models and information relations between these models in the CAPP system in the integrated CAD/CAM project are explained, a new process plan design method is mentioned based on analyses of process plan design. This method is based on the process plan prototype, and develops the prototype little by little until the perfect process plan is completed, the prospect of this method is discussed;(2) The feature abstracting rules and methods are studied, a feature coding system is developed based on GT, all the defined feature models are described by the mathematical methods;(3) The integrated method of CAD/CAPP based on features is mentioned, this method defines a feature exchanging model, and develops an interface software to exchange design data into technology data base, this technology data base includes the design and technology information of the parts;(4) The process plan reasoning method based on features is created, this method uses Mycin algorithm to solve the reasoning of the feature process plan. A process plan making system is developed. In this system part process plan is made by the semi-intelligent method, this method uses the feature reasoning, feature process chain searching and man-computer talking together;(5) The main structure of the HOPE system is introduced, a shaft drawing and its process plan made by this system are shown, the data process problem in process drawing making is also discussed;(6) A new method of describing process rule is introduced, this method uses IfThen rules and neural nets weight values together to describe process rules, the BP algorithm is adopted in this method;(7) The optimal machining sequence problem of the process steps on the same fixturing is discussed, optimal algorithms SA is applied to solve this problem, the result shows that this method is more efficient than the traditional method;(8) All jobs in the thesis are summarized. In order to carry out the research in the future, some rational proposals are given.

全文论述的内容主要有下列几个方面：(1)较为系统地阐述了CAD／CAM一体化工程项目中CAPP系统的主要功能模块及其信息流程，在分析工艺设计过程的基础上，提出了基于特征原型的渐进式工艺设计方法，并探讨了该方法的应用前景；(2)研究了零件特征提取的原则和方法，在成组技术的基础上，开发了一套基于特征的分类编码系统，并在提取零件特征的基础上，定义了零件特征的数据模型，开发了基于轴类零件特征的参数化设计系统；(3)研究了基于特征的CAD／CAPP集成的方法，通过定义零件特征数据模型的存储结构，开发了将设计数据转换到工艺数据库中的接口程序，为后续的CAPP系统提供必要的零件形状和工艺信息；(4)研究了基于特征的工艺推理方法，将Mycin算法应用到工艺决策中，开发了基于特征的工艺推理及工艺方案生成系统，在系统中综合运用特征推理、特征加工工艺链查询及人机对话相结合的半智能化方法确定零件加工工艺；(5)介绍了整个HOPE系统的总体结构，通过运行HOPE系统绘出了一轴类零件的零件图，并生成了该零件的加工工艺方案，初步探讨了基于特征的工序图生成技术中数据处理问题；(6)研究了工艺设计过程中知识如何有效表示的问题，提出了将显式的IF-THEN规则表示与隐式神经网络权值表示相结合的工艺知识表示方法，并利用BP算法进行了工艺知识表示的初步研究；(7)研究了工艺设计过程中同一安装下工步优化排序问题，利用神经网络中基于模拟退火的理论来解决该工步优化排序问题，实践证明该方法较传统的算法具有更高的效率；(8)总结了本文所进行的研究工作，为今后进一步开展工作提出了较为合理的建议。

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。

Systematic grid sampling is the most popular method at present, but it could loss some important distribution information. Systematic unaligned sampling is the most ideal method. It is easy to find periodical distributing field information with systematic unaligned sampling method.

其中规则栅格采样是目前最常采用的方法，但容易丢失一些比较重要的分布信息；系统分层采样是最理想的方法，容易发现具有周期性分布的农田信息。

In this paper Ⅰ successfully applied these methods to fault diagnosis, and presenting some new innovative machinery fault diagnosis method; First Ⅰ present a new gear wornout fault diagnosis method, this method use the vibration signal's time-frequency attribute and instantaneous phase undulation to accurately detect gear's fault, and by comparing with the traditional frequency domain analysis method, this method reveals that many nonlinear and nonstationary characteristic exist in gear's vibration, this tell us that if we use frequency domain analysis method without pay attention to the signal's characteristic, we could get wrong diagnostic result; Then Ⅰ present a new bearing fault diagnosis method, this method use ATVFD and Hilbert transform to do envelop demodulation,Ⅰ analyze the envelop with time-frequency method and find out that this method is more accurate then traditional method.Ⅰ also explain that the modulation of the fault to the carrier wave may also be non-stationary and nonlinear; Finally Ⅰ present a cylinder pressure measurement method of diesel engine by means of vibration, cylinder pressure is an important parameter of diesel engine fault diagnosis, the pressure measuring is simplified a lot by this method,Ⅰ also use the ATVFD and time-frequency analysis to realize it.

本文中将上述理论方法成功地应用到故障诊断中去，提出了几点创新性的诊断方法；提出了一种齿轮磨损故障诊断的新方法，该方法利用振动信号能量的时频域分布特征与瞬时相位波动特征可以进行精确的齿轮故障诊断，并通过与传统的频域诊断方法的比较，揭示出齿轮振动中存在的明显的非线性与非平稳特征，说明了不加选择地利用频域分析方法进行齿轮故障诊断很可能会得到错误的诊断结果；提出了一种轴承故障诊断的新方法，该方法利用ATVFD分解与Hilbert变换进行包络解调，并对解调得到的包络信号进行时频域分析，可以实现更加准确轴承故障诊断，说明了故障对载波信号的调制往往也是非平稳与非线性的；提出了一种利用振动信号进行柴油机汽缸内压力检测的新方法，柴油机汽缸压力的变化是柴油机故障诊断的重要参数，利用振动方法可大大简化汽缸压力的检测过程，该方法也是综合利用ATVFD分解与时频域分析方法实现的。

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。

Compared to traditional nonuniformly sampling method, this method solves the problem of redundant data due to over-sampling in the whole sampling period, and eliminates the partial redundance caused by signal time-variant feature.

与传统的非均匀采样方法相比，该方法既解决了整个采样时段内由于过采样造成的数据冗余性，也消除了信号时变特征造成的局部冗余性。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。