查询词典 frequency analysis

It is pointed out that with emergence of various fast algorithm and high performance signal processors, the utilization of frequency domain analysis or the integration of the frequency domain analysis, statistical method and modeling method will be the trend for paper defect detect investigation.

文章最后指出随着各种快速算法和高性能信号处理器件的出现，利用频域分析或是频域分析、统计方法和建模法的结合是纸病检测研究的一种趋势。

In consideration of the features of gearwheel drive box faults of the horizontal rotary screen roller printer and the basic principle of reversal frequency analysis and its advantages in failure diagnosis , reversal frequency analysis is adopted in fault diagnosis of gearwheel drive of the printing machine and better results are obtained.

介绍了卧式圆网印花机齿轮传动箱故障的特点以及倒频谱分析的基本原理和在故障诊断中的优点。

Some possible applications of wide-area measurement system in power system are gathered up, including applications in static analysis, recording dynamic procedures of the whole power network and post-contingency analysis, identifying and calibrating the dynamic model of power system, transient stability prediction and control, voltage and frequency stability monitoring and control, analyzing and damping the low frequency oscillation, global feedback control, fault location and parameter measurement o...

综述了广域测量系统(Wide-Area Measurement System，WAMS)在电力系统稳态分析、全网动态过程记录和事后分析、电力系统动态模型辨识和模型校正、暂态稳定预测及控制、电压和频率稳定监视及控制、低频振荡分析及抑制、全局反馈控制、故障定位及线路参数测量等方面的应用。通过这些应用可以看到，WAMS给电力系统分析与控制提供了新的视角和解决方法，值得深入研究。

The preliminary chromatogram data were resolved with Mallat algorithm of wavelet analysis theory. This method that resetting the high frequency signals, reconstructing low frequency and then correcting the background signals in the original signal was to avoid the data skewness with negative digital points after background correction and achieve the baseline correction; according to the study and analysis of simulated data including curve background and real data of the needle-plate and free metal partials insulation defects, the method is effective; the best wavelet function of the background correction is Db5 and the best resolution times of the background correction is 8 for chromatogram data of SF_6 decomposition products, based on the calculation with different wavelet functions and resolution times.

在初步获取的气相色谱数据基础上，运用小波分析技术中的Mallat算法对色谱数据进行小波分解，采取将高频信号置零，重构低频背景信号，再用原始信号扣除背景信号的方法，并对背景信号进行纵向平移以避免扣除后出现负数据点造成色谱峰失真的题目及达到色谱图基线校正的目的；通过对含曲线背景信号的模拟色谱数据和针-板、自由金属微粒缺陷下的真实数据的计算研究表明，该方法的应用是有效的；并通过对不用小波函数和不同分解次数的背景扣除计算，确定了SF_6气体放电分解组分色谱背景扣除所选用的最佳小波函数为Db5小波和最佳分解次数为8次。

Chapter 5 indicates that multi-scale time-frequency analysis such as wavelet and EMD could offer more information of HRV than traditional linear analysis ways in time domain and frequency domain, which is a research trend with those nonlinear ways.

第五章将从研究方法上指出以小波分析和EMD为代表的多尺度时频分析可以比通常的HRV时频分析方法揭示更多的信息，和非线性动力学分析一起成为HRV分析的发展方向。

In the method of time-frequency the phase of unbalanced force is confirmed by analysis of time domain and amplitude of unbalanced force is confirmed by analysis of frequency.

在这种时-频动平衡方法中，用时域分析来确定不平衡力的相位，用频域分析来确定不平衡力的大小。

The dissertation analysis different measurement on channel frequency,different vibration signals sets and different location to form each ICA result.With regard to the failure diagnosis of the turbine generator operation,the study has explored the possibilities to detect the failure diagnosis source from the measurement signals.It has also provided sufficient analysis case for the application of separation to detecting failure source on the turbine generator.2.Aiming at the engineering application of overcomplete bases ICA,the dissertation has raised virtual channel on the new method of ICA.It take advantage of some testified knowledge to the constitution of ICA known as, together with other measurement signal to proceed ICA separation,which can increase frequency on the input signal.

分析了以不同测量通道数量、不同振动信号类型组合和不同测点位置组成输入信号的ICA分离效果，并对机组在故障状态下，从测量信号中分离出故障源的可能性进行了探讨，为ICA在汽轮机振动故障源分离方面的应用提供丰富的分析实例。2针对超完备基ICA的工程应用问题，提出附加虚拟通道ICA的新方法，利用某些已经具有先验知识的独立分量构成附加输入信号，与其它测量信号组合在一起进行ICA分离，达到增加输入信号数量的目的。

Joint Time-Frequency Analysis is a new-style theory in Signal-Analysis, which combines the signals' characters in time domain with those in frequency domain. For reflecting the integral character, JTFT possesses good effect in analyzing unstationary or time-changing signals.

联合时频分析方法是一种新型的信号分析理论，它结合了信号在时间域与频率域的特性，反映了信号频率随时间变化的综合特性，在分析非稳定、时变信号方面具有很好的效果。

Paired t-test analysis was performed on the thresholds of SVR and PTA at each frequency (0.5, 1, 2 and 4kHz), and analysis of variance was performed on the difference between the pure tone audiometry threshold and the evoked potential threshold among different frequency.

对听力正常的46名志愿者，分别对双耳进行0.125~8kHz频率范围内的PTA阈值及0.5~4kHz频率范围内的SVR反应阈测试，通过配对t检验比较0.5、1，2、4kHz频率范围的SVR反应阈与PTA阈值的差异，并运用方差分析比较不同频率间的SVR反应阈与PTA阈值差值的差异。

According to the standard and request of mechanical structures for electronic equipment tests, the finite element model of the electronic equipment cabinet was built by using the software of finite element analysis-ANSYS and simulated the tests of random vibrations by loading and calculating. The 3-D isopleths graph of deformation and stress of the cabinet was obtained. It could confirm the maximum of deformation and stress of the cabinet and probability of occurrence. Through more analysis of the frequency response curve reflected directly and clearly the deformation of the cabinet within the particular seismic frequency.

根据电子设备机械结构随机振动试验的标准和要求，采用有限元分析软件ANSYS建立电子设备机柜结构的有限元模型，通过加载求解对其进行随机振动试验的数值模拟，得到机柜有限元模型的三维变形和应力等值线图，进而确定机柜承受应力和变形的最大值及发生概率；通过对频率响应曲线的进一步分析，可以直观明了地反映出机柜承受一定频率范围地震下的变形情况。

Molecular Distillation is a kind of high vacuum distillation method, which is suitable for the separation of high boiling, heat sensitivity and viscidity products.

分子蒸馏技术是一种在高真空条件下进行的连续蒸馏过程，适合于分离高沸点、热敏性及具有生物活性的混合物。

They are to the Noughties what yuppies were to the Eighties .

那在六十年代是时髦的，但在八十年代肯定是过时了