頻帶噪聲 的英文怎麼說
中文拼音 [bīndàizàoshēng]
頻帶噪聲
英文
band noise-
Compared with traditional mechanical and optic gyros, hrg has such advantages as no high speed circumvolving or moving parts in structure, no warm - up time and short start - up time, wide signal band in frequency, low excursion noises, great endurance in over loading, nuclear radiation and short time power off, small bulk, light weight, low power cost and long life, which is suitable for space applications
與傳統的機械陀螺和光學陀螺相比,半球諧振陀螺具有如下優勢:結構上無高速轉子、無活動部件;不需預熱,啟動時間短;信號頻帶寬,漂移噪聲低;能承受大的機動過載;抗核輻射,並可經受短時間電源中斷的影響;體積小,重量輕,功耗低,壽命長,非常適合空間應用。The distance between the acoustic-emission source and the receiving transducer, and the background noise level are primary factors in selecting a particular frequency band.
聲發射源與接收訊號傳感器間的距離以及環境噪聲的電平是選擇頻帶的主要依據。With the established rf front - end system simulation platform, adding the digital modulated baseband signal, this paper simulated the multifold digital modulated signal ’ s transmission, such as 2ask, qpsk, and 16qam. then researches of power compression and phase noise of local oscillation influence the bit error ratio for different modulated system. the designing is satisfied multifold functions request with the high - powered and integrated broadband rf front - end
隨后在建立的寬帶射頻前端通用模擬平臺上,加入基帶數字調制信號,對多種數字調制格式的信號在該通用平臺上的傳輸作了研究,模擬了2ask 、 qpsk和16qam等調制格式信號的發射與接收,研究了功率壓縮和本振相位噪聲對不同調制的誤碼率影響,實現了滿足多種功能要求的寬帶高性能綜合射頻前端的設計。We also proposed a reformed surface speed method based on the problems of surface speed method in engineering application. this method can make sure the structure radiant sound status in total noise and the detail phonate part quickly and correctly
根據表面速度法在工程應用中存在的問題提出了頻帶聲壓級差值法,該方法能快速準確地確定結構聲在總噪聲中的地位和結構的具體發聲部位。Because the speech signal is periodicity at sonant which vocal cords surge in low frequency and similarity to white noises at surd, the pitch can be detected in traditional way through the correlation operation without the speech produce model
在人類語音的濁音段,聲帶發生較低頻率的振蕩,語音信號呈明顯的準周期性,而在清音段,語音信號則類似於白噪聲。The signal format of gps is analyzed, the principle models and mathematical models are established, the ber performance is analyzed in a channel interfered with wide - bandwidth awgn, narrow - bandwidth awgn, transmitted signal, single - tone signal respectively. based on the results above interference methods are discussed and simulated. then the performance of code acquisition and code trace of a digital gps receiver are discussed. the modem of linkl 1 and link4a are modeled and their ber performances are analyzed and simulated in channel s interfered with awgn, single - tone signal and multi - tone signal respectively
建立了jtids的收發終端的數學模型,分析它在噪聲干擾、相關干擾、互相關干擾下的誤碼性能,提出較佳的干擾方法和干擾碼型,並進行模擬模擬;分析了gps的信號格式,建立了gps的原理框圖模型、信號數學模型,並對其在寬帶噪聲干擾、窄帶噪聲干擾、轉發干擾、單頻干擾等情形下的誤碼性能進行了分析比較,提出相對較佳的干擾方法,並做了計算機模擬,針對一數字式gps接收機中擴頻碼捕獲與跟蹤環的特性進行分析;建立了link11和link4a數據鏈調制解調數學模型,對它們在噪聲干擾、單音干擾、多音干擾等下的誤碼性能進行分析,最後對干擾情況進行了模擬模擬。The detecting accuracy of the beam drift would be improved, as a high performance acoustooptic modulator modulates the frequency of the laser beam drift signal far away from the power frequency, the double power frequency and high frequency noises
具體包括: 1 .利用聲光調制器將光束漂移量信號調制到遠離工頻及其倍頻干擾和高頻噪聲的頻帶段,以期提高光束漂移量的檢測精度。The paper produces noise reduction measurements and major frequency coverage that is 200 ~ 2khz to be used in selection of acoustical absorption and sound insulation materials. the measurement produces self - contained data to design lower noise railway vehicles in the future
本次測試的車輛車內噪聲主頻帶為20 2khz ,可依據此頻段進行新型車的設計和車體內部隔聲吸聲材料的選擇。The exhaust gas spews out of the exhaust valve and enters into the muffler along the exhaust manifold before draining into the atmosphere from the tail pipe. this process yields wide band exhaust noise
發動機廢氣從排氣門高速沖出,沿著排氣歧管進入消聲器,最後從尾管排入大氣,在這一過程中產生了寬頻帶的排氣噪聲。Radio - frequency noise jamming is an effective jamming to pulse compressed ( pc ) radar. it shows the best jam quality when it ' s bandwidth equals to the jammed signal ' s bandwidth and it ' s central frequency equals to that of the jammed radar ' s receiver
射頻噪聲干擾對脈沖壓縮雷達是一種有效干擾,在其帶寬等於雷達信號帶寬,中心頻率對準雷達的中心頻率時具有最佳的干擾品質。In the terms of interpolation, the image reconstructed from nearest interpolation or linear interpolation has good edge but serious noise ; reconstruction from 4 * 4cubic interpolation or three b - spline or three - order lagrange interpolations has better local character. 2 x 2cubic interpolations which has both better edge and local character is the ideal interpolation, the following is the basic principle during reconstruction : ( 1 ) the more width of interpolation, the more number of summation and the more order of interpolation polynomial, the higher of density resolution ; ( 2 ) the more of interpolation polynomial and width of interpolation, the more of reconstruction time simultaneously, aimed at eliminating the effects of noise contained in projection data, in this paper, author analysis cause and effects of common artifacts. importantly, discusses convolution back - projection reconstruction algorithm with a shift axis of rotation has been derived for correcting images that acquired with a divergence axis of rotation using the fan beam geometry with an angle - equaled detector
在ct圖像重建時,選擇有限帶寬窗有較好的空間解析度,三角形窗有較好的密度解析度,選擇餘弦窗則使得空間解析度與密度解析度的折衷;從窗函數的頻譜角度來講,可以用於圖像重建的一個良好的卷積窗函數應該具備以下條件: ( ? )小的3db帶寬b ,即最小的主瓣寬度; ( ? )最小的旁瓣最大峰值a ; ( ? )最大的旁瓣峰值衰減速度d ;就內插函數而言,臨近點內插與線性內插重建圖像噪聲大,但有較好的邊緣與細節; 4 4三次內插、三次b -樣條與四次拉格朗日多項式內插圖像平滑,局部特性較好。The clues and techniques to improve the resolution of data processing are 1 ) removing the affection of near surface factors on data acquisition, including static correction and noise eliminating technique etc, 2 ) broadening the frequency band of pre - stack seismic data, including amplitude compensation and pre - stack deconvolution etc, 3 ) improving s / n ratio of high frequency and weak reflection signals through multiple coverage with high precision velocity analysis, residual static correction and high - order nmo, raising " dead line of high frequency reflection ", and 4 ) identifying post stack effective reflection frequency band, enhancing dominant frequency and so on
主要包括:消除近地表因素對資料採集的影響,包括靜校正和噪音壓制技術等;疊前拓寬地震資料領帶,包括振幅補償和疊前反褶積技術等;藉助高精度速度分析、剩餘靜校正和高次項nmo技術,通過多次覆蓋疊加,消除資料中隨機噪聲干擾、提高資料信噪比,尤其是高頻端反射信息的信噪比,改善高頻反射和弱反射信號信噪比,提高「高頻反射死亡線」 ;疊後有限反射頗帶識別、抬高優勢頻率等。The main content and creative work in this dissertation include : 1. simulate the echoes of the radar, namely produce the lfm signals with band width equaling 5mhz, time width in 9 s ~ 42 s and analyze them in frequency domain pulse compression. at the same time suppress the clutter and indicate targets
本文完成的主要工作和創新之處有: 1 .通過模擬模擬回波信號,產生了帶寬為5mhz ,時寬在9 s ~ 42 s范圍內帶目標和噪聲雜波的lfm信號,並對其進行了頻域脈沖壓縮的分析,抑制雜波並顯示出目標。Frequency response, quantization noise, reconstruction error and its sensitivity to mismatch among adcs are studied at length in prqmf banks adc system, and the theoretic results include : ( 1 ) the distortion / aliasing functions of hybrid filter banks adc system is similar with that of switch capacitor filter banks adc system ; ( 2 ) for wide or narrow band input signal, the effective resolution of the two adc systems is 0. 51og2m bits higher than their adc ; ( 3 ) reconstruction error ' s sensitivity to mismatch among adcs of the two adc systems is reduced effectively than time interleaved adc system
2對prqmf濾波器組adc系統的頻響、量化噪聲特性、重建誤差特性以及重建誤差對adc間的失配敏感性進行了理論分析研究,所得到的理論結果為: ( 1 )混合濾波器組adc系統與開關電容濾波器組adc系統的失真/混迭函數一致; ( 2 )無論輸入寬帶還是窄帶信號,這兩種adc系統的有效解析度均比其adc提高了0 . 5log _ 2m比特; ( 3 )這兩種adc系統的重建誤差對其adc間的失配敏感性均明顯低於時間交織adc系統。We discussed common methods of digital deconvolution and analyzed effects of noise on it. then, we simulated digital deconvolution filters and optimization criteria of filtration parameters. after that, we gave the application of them in the frequency band extension technique
首先,介紹了數字反卷積的常用方法及噪聲對數字反卷積的影響;然後,研究了常用的數字反卷積濾波器及濾波參數的優化準則;最後,給出了數字反卷積在頻帶展寬技術中的應用。The low - frequency discrete noise of the propeller is induced by the interaction between blades of the propeller and wake of the marine, and the low - frequency broadband noise of the propeller is produced by the interaction of blades and turbulent field of the marine stern
螺旋槳的低頻離散譜噪聲是由船尾伴流場和葉片的相互作用引起的,而低頻寬帶噪聲是由船尾粘性湍流場和葉片的相互作用產生的。The former one is a product of the pressure pulsation resulting from the fan blade periodically cutting the air, with the blade passing frequency as its base frequency and accompanied by higher harmonics. the wide - band turbulent noise is formed when the rotating fan forces the surrounding air to produce turbulent throw - outs and results in gas thickening and thinning processes
旋轉噪聲是由於風扇的葉片周期性地切割空氣,引起空氣的壓力脈動產生的,以葉片通過頻率為基頻,並伴有高次諧波。湍流噪聲是由於風扇運動導致的周圍空氣發生湍流脫體,使空氣發生擾動,形成氣體的壓縮與稀疏過程而形成的,是一個寬頻帶噪聲。For rfi and narrowband noise interferences, this dissertation studies notch filter and spectrum equilibrium and uses them to suppress narrow jammings in signal domain
對于rfi和窄帶噪聲干擾,本文研究了頻域陷波和譜均衡兩種方法,並將之應用到信號域來抑制窄帶干擾。According to mechanism of low - frequency broadband noise of the propeller, theoretical analysis method is given and numerical calculation of the noise is worked out as well
在分析螺旋槳低頻寬帶噪聲成因的基礎上得到了理論計算方法,並作了數值計算。It is demonstrated that the theory and the method presented here can markedly improve the output snr, and minimize phase lag as well as the distortion of the system output signal with multi - frequency. a whole framework for multi - frequency signal processing is formed, including the methods of selecting system parameters and signal recovery
對于帶噪聲的多頻模擬信號,參數調節隨機共振方法能夠提高系統的輸出信躁比,並減小多頻模擬信號的波形畸變和相位延遲,本文給出了系統參數調節方法和信號反演關系,從而形成了較為完整的模擬信號處理方法。分享友人