頻譜包絡 的英文怎麼說
中文拼音 [bīnpǔbāolào]
頻譜包絡
英文
spectrum envelope-
Formant : it uses the estimation of the overall shape of the spectrum ' s amplitude envelope
共振峰:使用了對頻譜的振幅包絡線的大體形狀所作的估計。So they can not be used in on - line fault detection and condition monitoring. and the explanation of the time - frequency analysis is not easily accepted by the engineers. the experimental factors, such as rotational speed and measured position and fault distribution a
文中還針對轉速、測點位置、故障分佈（位置） 、負載等因素對頻譜分析、包絡分析、時延相關解調等方法的診斷效果進行了大量的實驗研究。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。From the research of ijf - oqpsk, we draw the conclusion that, compared with bpsk, qpsk and msk modems, in the band - limited and non - linear channel, it has nearly constant envelope, less spectral spreading, better pe performance and the less interference of the adjacent channel, et. so, it is more suitable for the satellite communication channel
通過對ijf ? oqpsk的分析研究可知，它相對于傳統的bpsk和qpsk調制方式，在帶限非線性通道下，具有包絡近似恆定，頻譜擴展小， eb no惡化小，對鄰道產生干擾弱等優點，因而它更適合於衛星通道。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。The advantages of the modulation method omsk ( the gaussian pre - filtered minimum shift keying ) include bandwidth efficiency and constant envelope
Gsm系統中採用了gmsk調制方式， gmsk調制恆定包絡，具有較高的頻譜利用率。In large rotating machinery using filmatic bearing ( turbogenerator, air compressor, etc. ) there is a potential trouble from impefect installation or running conditions, a metals " contact between rotors and shells. the trouble is usully called rubbing. the advantage of ae technologe in the rubbing diagnosis and early detection is showed. instead of classical ae characteristic parameters ( counts, amplitude, energy, duration and the other ones ) a new feature extraction by frequency analysis of ae envelop signals is discussed. both research of ae process and field experements indicate that periodic components in the envelop spectrum related to rotational speed increase evidently at the beginning of rubbing production, hence are highly sensitive to the rubbing fault diagnosis. according to the new design an acoustic emission equipment for the rubbing diagnosis named buaa ae testing system is developed and described
汽輪發電機、空氣壓縮機等採用油膜支撐的大型轉動機械，由於安裝或運行中的原因，在轉子旋轉過程中，可能和器壁發生輕微的摩擦和碰擊，簡稱碰摩.聲發射技術在碰摩發生特別是故障早期診斷上有優越性.本系統的特點是沒有沿用傳統的計數、幅度、能量和持續時間等聲發射特性參數，而是在聲發射包絡信號的頻率分析中進行特徵提取.聲發射發生的過程分析和現場試驗都表明這種方法對碰摩檢測很敏感，在碰摩發生的起始階段，包絡譜中與轉速同步的周期性分量顯著增加.根據這種新的設計思想自行研製了buaa碰摩聲發射檢測儀並對此作了介紹分享友人