功率谱分析

• The thesis analyses the signal of vibration and noise of water system in pump room through power frequency spectrum analysis and coherence analysis . meanwhile uses finite element method ( fem ) to investigate the characteristics of pipe system
  论文通过功率谱分析、相干分析等方法对供水系统泵房内的管道系统进行振动与噪声信号的分析，用有限元的方法分析管道系统的结构特性。
• This chapter gives comprehensive analysis from general analytic way , fourier analysis to relevant analysis of signal and analyzing the power chart . , especially form the theory talking of the signal processing
  该章节从信号的一般分析方法、信号的傅里叶分析、信号的相关分析以及信号的功率谱分析，依次进行了全面的分析，从理论的角度对信号分析所进行的处理工作作了全面的阐述。
• It is found that , the modes of coaxial optical emission of dissimilar gaps , clustering at distinct numerical range , can distinguish 1st , 2nd and 3rd class welds of different welding quality effectively
  结果表明，同轴光信号幅值的众数在不同间隙的焊缝段，聚集在线性可分的不同的区间，可以有效分开焊接质量不同的类、类、类焊缝；信号的分段功率谱分析能够较为直观地反映焊接状态的变化。
• The power spectrum analysis can with accurate examine a rolling bearing ’ s structure and processing and assembling the error margin . time sequence analysis can pass to build up the time sequence model , we can see the peak of the spectrum of the fault ’ s clearly
  功率谱分析可以精确诊断滚动轴承结构和加工装配误差类故障。时间序列分析能通过建立时序模型,从谱图上来更清晰的看出故障的谱峰。
• The main contents are as follows : by means of power spectrum analysis , coherence analysis , modal analysis and finite element method ( fem ) , the identification of noise sources of water supply system is successfully achieved
  本文的主要工作和取得的成果如下：针对供水系统噪声污染严重的问题，进行了噪声源识别。运用功率谱分析、相干分析、模态分析技术、有限元法相结合的方法，找到了主要的噪声源。
• In this paper , on the basis of observed data , spatial - temporal variation characteristics of soil temperature and soil moisture . soil temperature effects on soil water movement are studied for several kinds of typical underlying surface by using statistics , spectrum , filtering wave methods
  本文首先根据几种典型下垫面条件下的土壤表层( 1 - 1m )的土壤温湿度资料，采用统计分布、功率谱分析、滤波等方法分析典型下垫面条件下土壤表层水热分布特征及其相互作用。
• The signals are transformed into digital signals and sent to a computer . digital signal processing includes amplifying the sound signals , low - pass filtering , wavelet transform for de - noise and analyzing power spectra using matlab software . for different species of pests the acoustic characteristics are different in time domain and frequency domain
  害虫声信号采集系统由日本产teac ；四通道录音机（数字记录仪）记录害虫爬行声信号，数字示波器将声信号转变为数字信号送计算机存储，由matlab软件对数据文件进行信号处理，包括信号的再现、放大、滤波、小波去噪、功率谱分析等工作。
• In order to study the characteristic signals according to the quality of the welding with dissimilar gaps , the self - made real - time monitoring system with coaxial sensors is applied to acquire and extract coaxial signal , and then the signals are analyzed with modes analysis , subsection power analysis and wavelet analysis
  摘要为了研究不同间隙下激光拼焊的焊缝质量及其对应的信号特征，采用自制同轴传感系统采集提取多种间隙下焊接时的同轴光信号，并对信号进行众数分析、分段功率谱分析和小波分析。
• The card is used to acquisite the input signal in a / d chip , accomplish the fft transfering and power spectrum analysizing in dsp chip , then send data to computer by pci interface . the model of dsp is tms320vc5402 of ti company and the pci interface chip is s5920 of amcc company . in this article , author adjusts and debugs the card , then develops the driver for the card
  信号采集/处理pci卡实现将输入信号经a / d变换后，在dsp中进行fft变换、求模运算以及功率谱分析，通过pci接口输入计算机。 dsp采用ti公司的tms320vc5402芯片， pci接口选用amcc公司的专用接口芯片s5920来实现。
• ( 3 ) though the conventional fourier power spectral analysis can reflect the common characteristics of the signal , it cannot provide the fine structure of time - frequency changes and the location of the jump points , while the wavelet transforming can better the situation
  传统的功率谱分析方法虽然能反映气候信号变化的一般特征，但无法反映时频域变化的精细结构，也不能给出突变点的具体位置；而小波变换分析方法则可以很清楚地给出气候信号变化的多层次结构和突变特征。