查询词典 harmonic function

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

In this paper, we proposed continuous interval argument OWH operator for aggregating continuous interval argument on the basis of ordered weighted harmonic averaging operator. Based on C-OWH operator, we proposed some new concepts, such as weighted harmonic C-OWH operator, ordered weighted harmonic averaging C-OWH operator, combined C-OWH operator, and we discussed some properties of these operators.

本文首先把OWH算子推广到了连续区间上，提出了连续的区间数据OWH算子，然后在此基础上提出了加权调和的C-OWH算子，有序加权C-OWH算子以及组合的C-OWH算子等新的概念，探讨了它们的一些性质。

In recent years, high voltage direct current system is rapidly developed, but harmonic pollution is produced and becomes badly, harmonic measurement by true is the precondition and sticking point of restraining harmonic.

近些年来，高压直流输电得到了快速的发展，电网的谐波污染也日趋严重，实时、准确地测量谐波电流信号是有效抑制谐波电流的前提与关键。

A new harmonic harmonic and reactive current detection method and a harmonic current detection method base on bandpass filter are introduced in this thesis.

提出两种新的检测方法，检测谐波及无功电流的改进算法和只检测谐波的基于数字带通滤波的检测算法。

A logicaldomain is used as a reference and the mesh movingis implemented according to an appropriate domain transformation.With sometraditional moving mesh methods,the meshes in physical domain may be tangled.To avoid this,the transformations are constructed based on harmonic mapping.Agood feature of the adaptive methods based on harmonic mapping is that existence,uniqueness and non-singularity for the continuous map can be guaranteed fromthe theory of harmonic maps.

在移动网格方法中，需要引进一个逻辑区域作为参考，网格的移动往往通过一个区域变换来实现，网格可能发生缠绕的问题是移动网格方法中一个一直没有解决的问题，我们利用调和映射来构造区域间的变换，使得变换的存在唯一生有了理论的保证，这就为避免网格缠绕打下了基础。

Harmonic measurement is an important embranchment of harmonic problem. It is not only the main basis of studying the harmonic problem, but also the starting point of analyzing the problem.

谐波测量是谐波问题的一个重要分支，它是谐波问题研究的主要依据，也是研究分析问题的出发点。

Fluxgate sensors have the second harmonic voltage amplitude with the magnetic field strength is proportional to the adoption of second harmonic filter through phase-sensitive detector rectifier, to achieve full-wave rectifier, low-pass filter in through the phase-sensitive detector after the second harmonic into a smooth DC signal, on the one hand to the back of the circuit, on the one hand, the magnetic flux through the door to feedback regulation, the opposite magnetic field generated with the measured magnetic field, so that the work has always been zero fluxgate magnetic field, thus ensuring the most high-precision fluxgate.

磁通门传感器产生的二次谐波电压幅值与磁场强度成正比，二次谐波通过通过滤波器再通过相敏检波器整流，实现全波整流，在通过低通滤波器将相敏检波后的二次谐波转化成平滑的直流信号，一方面送到后面的电路进行，一方面通过反馈调节送到磁通门中，产生与被测磁场相反的磁场，使磁通门始终工作零磁场下，从而保证磁通门的最高精度。关键词：磁通门磁力仪，相敏检波器，磁场

However, because of the positive sequence of fundamental frequency, there are still some shortages for wavelet transform in the use of harmonic measurement of three-phase dissymmetrical system. A new approach of harmonic measurement based on Period-interleaving of MALLAT arithmetic for dissymmetrical system is put forward. Analysis and experiment based on TMS320LF2407 Digital Signal Processor are made. And the result of experiment reveals that the proposed method based on Period-interleaving is valid in the use of harmonic measurement of three-phase dissymmetrical system.

但是，目前小波变换在三相不对称系统的谐波检测中存在着无法分离基波正序信号的不足，本文就此提出了一种用于三相不对称系统的基于周期交错的小波MALLAT多分辨率分解的测量方法，详细介绍了该算法的原理、流程及计算公式，同时以TMS320LF2407数字信号处理器为核心建立了实验系统对该算法进行了实验，实验结果证明该周期交错－小波变换算法可以有效地检测出三相不对称系统中的有害电流。

The capacitance capacitors and inductors of power grid form parallel resonance circuit .It's frequency may be related to the existing power grid close to the harmonic frequencies, If there is power grid harmonic current sources, harmonic resonance caused by enlarged so that the voltage and current waveform distortion even more serious.

电容器的电容和电网的电感形成并联谐振回路，其频率可能与电网中存在的谐波频率接近，如果电网存在谐波电流源，谐振引起的谐波放大使电压和电流波形畸变更为严重。

For mastering on-load property of the third harmonic excitation system . Thus , a new method to analyze harmonic winding no-load property curve of harmonic excitation synchronous generator , named as three-segment method , is presented in this article.

为了把握三次谐波励磁系统的空载性能，本文提出了应用三段法来分析三次谐波励磁同步发电机谐波绕组空载特性。

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。