波包頻譜 的英文怎麼說
中文拼音 [bōbāobīnpǔ]
波包頻譜
英文
wave packet spectrum- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 頻 : Ⅰ形容詞(次數多) frequent Ⅱ副詞(屢次) frequently; repeatedly Ⅲ名詞1 [物理學] (物體每秒鐘振動...
- 譜 : Ⅰ名詞[書面語]1 (按類別或系統編成的書或冊子等) table; chart; register 2 (指導練習的格式或圖形)...
- 頻譜 : frequency spectrum; frequency content; spectrum; power density spectrum; power spectrum; [系統] s...
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The signal process function of the software include these function : digital filter, windowing, auto - correlation function and cross - correlation function, mean and variance, probability density function and probability distribution function statistic ; auto - power spectrum, cross - power spectrum, frequency response function, coherence function, cepstrum analysis based on fft ( fast fourier transfer ) ; joint time - frequency analysis based on stft ( short - time fourier transfer )
軟體的處理功能包括:數字濾波、時域加窗、自相關與互相關處理、均值和方差計算、概率密度和概率分佈函數計算;在快速傅立葉變換( fft )基礎上計算自功率譜、互功率譜、頻率響應函數、相干函數、倒頻譜分析;基於短時傅立葉變換( stft )的聯合時頻分析等。3. with comprehensive improvement of transponder including structural adjustment to lna ; optimization of ( phase locked loop ) pll filter ; structural adjustment to the transmitter and phase error adjustment to the intermediate frequency demodulation circuit, we have successfully enhanced sensitivity, expanded dynamic range, increased transmitting power and improved the spectrum purity ; decreased capture time for pll ; improved the signal quality after demodulation ; reduced its volume and power consumption. 4
3 、對通信機的全面改進,包括lna結構的調整、鎖相環環路濾波器的優化、發射部分結構的調整以及中頻解調電路的相差調整,提高了系統的接收靈敏度、改善了本振的頻譜純度、減少了鎖相環的鎖定時間、使中頻解調后的信號質量大為提高,同時還減少了體積、節約了系統的功耗。In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal, wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station, in which the signal is decomposed into different frequency band, and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基於李家峽水電站雙排機組振動的現場試驗研究,並且針對傳統頻譜分析方法傅立葉變換( fft )對于非平穩信號已力不從心這一缺陷,利用小波分析方法在時域和頻域上同時具有良好的局部化性質,通過對開停機這一典型非平穩過程信號進行小波及小波包分析,將其分解到不同頻帶內,獲取微弱信息和提取優勢頻率,並對其作振源分析,得出開停機初始時刻因水流不穩均出現強烈的振動現象,且低頻段信號能量最大,開停機過程水流脈動壓力和尾水渦帶擺動是引起定子基礎振動的主要原因。These include the well - known am, fm, shortwave and citizens bands and vhf and uhf television channels, as well as hundreds of less familiar bands that serve cellular and cordless telephones, gps trackers, air traffic control radars, security alarms, radio - controlled toys and the like [ see box on page 71 ]
這些頻率包括眾所周知的am 、 fm 、短波、民用頻帶, vhf和uhf電視頻道,以及數百個較不為人知的頻帶,供行動電話、家用無線電話、 gps追蹤系統、航空管制雷達、安全警示與無線電遙控玩具等使用(見85頁無線電頻譜) 。This article describes a way of special ultrasonic system which monitors thermal stress in seamless welded rails. this monitoring system is a non destructive testing system, which adopts avr mcu and high - precise time chip processing as the core of it, and adopts the critically refracted longitudinal wave as the object of measuring. my studying focuses on the theory of the monitoring system, which will be listed in this arctile : according to the snell theory, the theory of motivating of critically refracted longitudinal wave is described in details, and the finite element software is used to emulate the propagating course. the formulas of calculating the pts of swr are taken from the acoustoelasticity theory, and the calculating the parameters is introduced. according to assemble materials, three kinds of ways of monitoring the pts of swr using critically refracted longitudinal wave are described, which are measuring the sound - time in changeless distance, ultrasonic critical - angle refractomery and frequency spectrum, the first way of ways is used in this experiment system. the factors, which effect the monitoring system, are assaid in some degree based
本文的研究工作重點在無縫焊接鋼軌溫度應力測量系統的理論模塊,包括根據snell原理,研究極限折射縱波的激發機理,並使用有限元軟體ansys進行模擬;根據聲彈性理論以及公式推導出計算無縫焊接鋼軌中的溫度應力的公式,並對其中參數的求解方法進行介紹;根據收集的資料,介紹了三種使用極限折射縱波測量無縫焊接鋼軌溫度應力的方法,即固定距離測量聲時法、臨界角折射法和頻譜分析法,本實驗系統使用的是第一種;根據實驗經驗以及相關資料,分析了影響極限折射縱波測量溫度應力的幾個因素,並提出了相應的解決方法;根據實驗系統的需要,獨立設計並加工出相關配套的實驗設備,包括實驗鋼塊、有機玻璃楔塊、固定件、載荷外框裝置等。Then, we introduce the basic structure of pd weather radar signal processing system and their function of each subsystem, mainly including intermediate frequency receiver, clutter elimination, range correcting and smoothness, ambiguity resolution and spectrum estimation
並在此基礎上介紹了氣象雷達信號處理系統的基本構成與各部分的主要功能,主要包括氣象回波中頻接收、雜波抑制、距離訂正、平滑處理、解模糊和譜矩估計等。By theory and practice simulation, the several types of constant envelope modulation techniques are analyzed and compared, including theirs modulation principle, phase path, the modulated wave envelope, power spectrums, error bit rate and the influence of its power spectrums of the band - limited and non - linear, etc. especially we have researched the ijf - oqpsk modulation technique, and the performance of its inter - symbol interference and time jitter free, and its strongly resisting of spectral spreading
結合理論和實驗模擬結果,分析討論了衛星通信中的各種恆包絡調制技術,對它們的調制原理,相位路徑,已調波包絡,功率譜密度,誤碼性能,以及帶限非線性通道對其功率譜的影響等方面都作了研究和比較。特別研究了ijf ? oqpsk在消除碼間干擾和定時抖動方面的性能及其優良的旁瓣特性和抑制頻譜擴展特性。Wavelet analysis is used to translate noise signal of the engine into time - frequency domain. selecting appropriate frequency band to pick up and making its envelope spectrum, then two feature frequency - 0. 5x speed frequency and 2x speed frequency that represent the abrasion condition can be found. in addition, a new diagnosis method of image processing technique is proposed
利用小波分析將測得的機體噪聲信號變換到時頻域,選擇合適的頻帶加以提取並進行包絡譜分析提取包含特徵頻率的包絡,通過分析提取后的0 . 5倍頻和2倍頻分量,發現兩個特徵頻率可準確反映主軸承的磨損狀況。It was the result from that the width of spectrum of the input em pulse packet was too wide, the spectrum included rather strong frequencies being above the cut - off frequency which have not been decayed
分析認為,這是由於輸入電磁波包脈沖的頻譜太寬,存在較強的高於截止頻率的頻率,這部分頻率未被衰減而直接傳輸所致。Abstract : a software method of frequency - modulated signal demodulating based on wavelet packet is proposed in this paper. a variety of frequency - modulated signals are analyzed in time - frequency domain and the spectrograms are presented. this method can detect instantaneous frequency effectively and get frequency - modulated information, can be widely applied to dynamic testing and software radio
文摘:提出了基於小波包的調頻波解調方法,通過對各種調頻信號進行時頻分析,給出了信號的時間?頻率譜圖,能有效地檢測到瞬時頻率和獲取調頻信息,該方法可廣泛應用於動態測試和軟體無線電等領域。The aim of the task is to detect moving target in the varied clutter environment, which contains the following contents : ( 1 ) radar theories relational to the task, including clutter character, their magnitude and spectral distributions. in this part, moving target detection method is introduced, several methods on clutter suppression is presented
本課題的主要目的是進行雜波環境下的動目標檢測,由以下部分組成: ( 1 )與本課題相關的雷達理論知識,包括雜波特性,它們的幅度分佈和頻譜分佈、處理方法,動目標檢測的原理以及雜波抑制的常用方法。In this paper, first, the study of the distribution of electromagnetic field, energy, power, reflection coefficient and transmission coefficient in waveguide with piecewise different dielectric constants are studied. then, the behavior of propagation of am signal and gauss pulse signal through the waveguide are simulated by magic code , and the plots of electromagnetic field, energy, ponyting vector and their spectrums at different time and different position are obtained. and, the group velocity and energy velocity of wave packet through barrier are calculated
從90年代開始, emig和martin 、 landauer等人研究了分段填充不同介質的波導中的電磁脈沖的傳播。在本論文中,作者首先推導出分段填充不同介質的波導中的電磁場分佈、能量、傳輸功率以及反射系數和傳輸系數的表達式,然後,採用magic程序模擬了這種波導結構中電磁波的傳播情況,得到了在不同時刻和不同位置處的電磁場分布圖、能量圖、坡印廷矢量圖以及它們的頻譜圖,並由模擬結果計算了波包穿越勢壘的群速和能量速度。From the angles of the energy spectrum and distribution of feature frequency, ways of analysis on the tendency of signal in frequency domain are presented, and a method of solving frequency mixing is discussed
從能量譜和特徵頻率分佈的角度,研究了監測信號的變化趨勢在頻域的表徵,並提出了一種解決小波包混頻現象的方法。Through analyzing strata ' s absorbtion and attenuation, the specialty of ssf in system - one ( two ) and 24 - bit a z a / d, the scheme to improve the data acquisition system is brought forward including the design of multiple differential spectrum equilibrium filter ( mdsef ) and program control amplifier
通過詳細分析地層的吸收衰減特性, system - one ( two )頻譜整形濾波器及24位a d的特點,對現有採集系統提出了改進方案。其中包括對多級微分頻譜均衡濾波器的理論設計,程式控制型前置放大器的理論分析與設計。4 different types ’ features were generated, namely ar model parameters, power spectral frequency band intensity, energy for wavelet packet decomposition, wavelet packet entropy. every type of features were extracted respectively using pca and ica method and classified using linear neural network, knn and bp network
建立了ar模型參數、功率譜估計頻帶強度、小波包分解能量比率、小波包熵四種特徵,分別使用pca與ica進行特徵提取,採用線性神經網路、 k -緊鄰法、 bp神經網路四種分類器進行分類。In this paper, a new way of real - time damage detection method was proposed according to the high speed working situation of the composite flywheels for energy storage, and a suit of equipment was developed to test the composite samples with piezoelectric disc built - in, the response waves before and after the damage occurred were recorded to the computer. on the base of traditional spectrum analysis of signal recorded, the wavelet analysis was introduced and the program in matlab language was made. with the wavelet packet decomposition of the signal, the relations between the change of response signals and damage characters were gotten, a database for damage recognition was created
本文結合儲能復合材料飛輪高速旋轉的工作特點,提出了一種在線檢測飛輪轉子損傷的方法,自主設計一套實驗裝置對模擬各種損傷的的試樣進行了測試,試樣損傷前後的響應信號被採集后存入計算機中;在對採集信號進行傳統的頻譜分析的基礎上,引入了先進的小波分析理論,利用matlab語言編寫程序,對信號進行小波分解,得到了信號變化和損傷特徵之間的關系,建立了一個識別飛輪損傷的數據庫;小波包分解得到信號對比圖和特徵向量,可以有效判定材料內部有無損傷和損傷的程度,結合頻譜分析等,可一定程度上判定損傷的類型,為儲能飛輪的安全運轉和智能化運作提供了決策依據。As another application instance, a subsystem monitoring ultra - high frequency partial discharge of transformer is developed, which can analyse, process, plot time - domain pd data and demodulated pd data, besides, it also has such discharge type recognition function as spectrum calculation and auto correlation
作為另一應用實例,研製了變壓器超高頻局放監測子系統,此系統具有分析、處理、顯示超高頻時域波形及其包絡線波形數據的功能,還具有用於放電模式識別的時域波形及其包絡線波形的頻譜計算和自相關處理等功能。A gis pd measuring system is established, including a conventional pd measurement system, uhf detecting system and a pd spectrum system. we can obtain pd signal characters by this system, such as uhf transient signal waveforms, uhf demodulating signal waveforms, the pd phase angle in ac, pd spectrum, and discharge quantities
建立了gis局部放電測量系統,其中包括:常規局部放電測量系統、超高頻檢波測量系統和放電頻譜測量系統等,通過測量系統得到了gis內局部放電的超高頻暫態信號波形、檢波信號波形、工頻相位分佈、頻譜特徵以及常規視在放電量等特徵。Finally, the production, which is designed and debugged all by myself, c band fine resolution low phase noise frequency synthesizer was introduced by module, including respective schedule, frequency distribution and phase noise experiment results. then whole circuit phase noise result, picture of spectrum with spur were presented, by which above theory was proved, analysis of the result was given, and the existing problem as well as methods to resolve it were motioned
論文最後對自己設計調試的樣機c波段小步進低相噪頻率合成器進行了分模塊介紹,包括各部分的原理框圖、頻率分配和相噪測試結果,然後給出了整個樣機的相噪、雜散頻譜測試結果,對上面提到的理論進行驗證,並對結果進行了討論分析,提出了樣機現存的一些問題和幾點解決措施。The main research in this thesis can be summarized as follows : ( 1 ) the structure and features of tc620 turbo cycling compressor are introduced. its frequent faults, fault mechanism and diagnosis are also analyzed. ( 2 ) the vibration signal analysis based on fault analysis and processing are presented, including wave analysis, tarce analysis, frequency spectrum analysis etc. and connected signal transformation ideas are also described, which can be conducted in amplitude field, time field and frequency field according to different needs
本文主要包括以下內容: ( 1 )介紹了tc620透平循環壓縮機的結構特點,歸納總結了其常見的故障現象,分析了各類故障產生的機理和診斷方法; ( 2 )論述了基於故障分析處理的幾種常用的振動信號分析法,如波形分析、軌跡分析、頻譜分析等。分享友人