波數頻譜 的英文怎麼說
中文拼音 [bōshǔbīnpǔ]
波數頻譜
英文
wave number frequency 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...
- 數 : 數副詞(屢次) frequently; repeatedly
- 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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We also researched the frequency structure of ddc and interchanged the filter multiphase heft and taking out - operation using the theory of equivalent counterchange in multisampling system
從理論上研究了數字下變頻的頻譜結構,利用多采樣率系統中結構的等效變換原理,將濾波器多相分量與抽取操作進行互換。Lfmcw radar adopts the receiver with the structure of “ homodyne - fourier ”, and acquires the range spectrum after its if signal is sampled, and then processed by ftt
Lfmcw雷達採用了「差拍-傅立葉」接收機結構,其回波中頻信號經數字採集后進行fft處理,從而獲得雷達的距離譜。Hi this thesis, the technique of detector array is used to obtain the location of anomalous infrasound, it is the basic of the study of prediction of earthquake. to derive useful information by using spectrum analysis on infrasonic signal. then combing with other methods a forecast could be made
本課題主要是利用數字技術,採用用傳感器陣列計算異常次聲波波源的方位,這是今後預測震中位置研究的前提;並對次聲信號進行頻譜分析,提取有用的關于臨震次聲方面的信息,再結合其他的預報方法,作出準確的地震預報。Frequency - wavenumber energy spectra in isotropic turbulence
均勻各向同性湍流的頻率波數能量譜On the other side, we use the method of optical formation process to introduce two fundamental filtering function in frequency domain of coherence system of awg two optical processors are designed, that is optical signal add / minus and phase filter
另一方面,運用光學信息處理方法,我們探討了awg型相干系統頻譜區兩類基本的濾波函數的引入,設計了兩種光信號處理器:光信號加減器以及位相,濾波器。The second, the main work in the paper is discussed. they are include : the theory and character of electromagnetic leaking from a computer ; the theory of accumulation mean filter and pectination filter ; the analysis of synchronous signal precision, at 10 - 12 second level, for stably intercepting ; the technology requirement of receiver and data acquisition board for clearly displaying the images recovered from the intercepted data
本文從計算機視頻電磁泄漏和數字濾波器兩方面的基本理論出發,詳細論述了計算機視頻信息電磁泄漏的原理及特點,指出視頻泄漏信息的頻譜是以行頻為周期的譜線;分析了重加濾波器和梳狀濾波器的性能;分析了視頻泄漏信息截獲的條件;推導出穩定截獲視頻泄漏信息需要對同步信號的精度控制在皮秒級;論述了清晰再現對接收機和數據採集卡的技術要求。In this thesis, for the merits of high frequency spectrum utility factor and high - speed data communication, the ofdm is introduced into the underwater acoustic communication. combined with fec to combat the frequency - selective fades and isi in the underwater acoustic channel, high speed data transmission is realized by employing ofdm technology
本研究嘗試將ofdm技術引入水聲通信領域,利用該技術頻譜利用率高,多載波并行傳送的特點,結合通道編碼,以克服水聲通道多徑干擾引起的頻率選擇性衰落和碼間干擾,獲得高速率數據傳輸。In the study of directional spectrum and reflection coefficient of multidirectional wave, firstly the wave elevation trains overlapped by the incident wave and the reflected wave of multidirectional wave are simulated in the method of a frequency corresponding to a direction. then the composed wave trains are analyzed respectively by the mbdm and the mmlm. during the numerical study, the input factors include the various wave parameters, the different measuring wave system and the various reflect characteristic
在多向不規則波入射波方向譜和反射系數的分析研究中,利用方向頻率對應法模擬了多向不規則波入射波與反射波疊加的波面序列,將此合成波列分別應用mbdm和mmlm進行分析,通過輸入各種波浪參量、不同波浪測量系統和各種反射特性等因子,檢驗了mbdm和mmlm方法的適用條件,對兩種分析方法的性能進行了比較分析。The spectrum analysis showed that only the balance signals require processing by digital filter, and only inherent frequency components of balance, bracket and model system of the balance signals will require filtering, but the resonance components of test force oscillatory are. saved as more as possible
數據的頻譜分析結果表明只須對天平測量信號做數字濾波處理;濾波原則是僅需濾掉天平、支架、模型系統的固有振動頻率分量,同時盡可能多地保留實驗強迫振動的各階諧振信號。The delay chip, whose delay precision can be 10ps, wide band sample - hold amplifier ( sha ), and high speed and precise analog / digital conversion ( adc ) are used in the system
能夠對5mhz以下的信號進行隨機采樣、波形顯示、頻譜分析,還能夠對採集的波形數據進行存儲、共享。To utilize the advantages of dsp chips, the system should be computing sources economical. according to digital signal processing theory, the poly - phase fir can help reduce the workloads of the ddc / duc. therefore, adding the complex carrier mixers, the channelization system ( a method of using a single wideband facility to transmit many relatively narrow - bandwidth signals. by subdividing the frequency spectrum used in the wideband channel ) can be formed utilizing the characters of fft
為了使開發出的軟體可以適用於高速dsp器件開發,節省系統資源,課題首先從數字信號處理的理論進行分析,得出可以利用抽樣率轉換的數字濾波器的特點,即多相濾波實現數字上下變頻計算負擔的減小,之後進一步將多相濾波器與頻譜搬移部分結合,通過公式的推導,得出可利用快速傅立葉變換的特點實現多路信號的通道化發射和接收的處理模型。Secondly, the wavelet transform of ae signals collected in experiment is carried out with db6 wavelet and scale 3 on the basis of the signal ' s frequency analysis. the high frequency d, signal is ae characteristic signal. and by choosing the level ' s wavelet coefficient as its input, the wavelet - neural networks can be trained with the data of ae experiment, and the ae signals can be effectively recognized
然後,在實驗與對實驗所採集數據頻譜分析基礎上,根據對小波分析用於信號處理可行性研究,本文選擇db6母小波、尺度j = 3對實驗所採集數據信號進行小波變換,變換后其高頻成分d _ 1信號即為聲發射特徵信號。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。Statistics of wave crests with different directional spreading parameters and different directional functions are obtained and discussed. jonswap spectrum and the directional function suggested by mitsuyasu, donelan and wen respectively are employed in the analyses. statistical distribution of wave crest characteristics such as crest length, crest height, and directional angles based on the above - mensioned numerical simulation of 3 - d random waves are analyzed
以jonswap譜為頻譜,選取光易型方向函數(含三個參數) 、 donelan方向函數以及文氏方向函數等不同的方向函數進行模擬,對得到的波峰形式進行比較,分析了方向函數對波峰長度統計值的影響。Propagation of spectra affected by third - order dispersion in dispersion - decreasing fiber near zero dispersion wavelengths was studied by means of numerical simulation
摘要為探討三階色散對脈沖傳播的意義,用數值模擬的方法討論了在色散緩變光纖中零色散波長附近三階色散對脈沖頻譜演變的影響。In this thesis, summarized the basic theories of fourier transformation and the fast fourier transformation that are generally adopted to detect and analyze the electric power harmonic in the electric power supply system. at the same time, summarized the even sample principle, the phenomenon of frequency mix, the window functions and the frequency leaking as so on, those are closely - related to sample from figure signal
簡要闡述了電力系統諧波檢測分析所普遍採用的傅利葉變換和快速傅利葉變換的基本理論以及與數字信號采樣密切相關的均勻抽樣定理、頻譜混疊現象、窗函數和頻譜泄漏等的基本理論。It is shown that the spectrum of the backward scattering signal of a rotating target is a slice of the spectrum of the scattering intensity function of the target in the corresponding aspect of the system, weighted by the spectrum of the incident signal
本文簡要分析了目標電磁散射與impsar成像有關的信號模型。經對沖激雷達旋轉目標某一方向的回波信號的分析,得知它的頻譜是目標散射函數頻譜在對應方向被發射信號頻譜加權了的一個切片。Finally in chapter 6, the problems of boundary conditions and incident wave, as the most valuable problem of mrtd as a time - domain method, are studied. this chapter presents the simulation results of the electromagnetic propagation and its interactions with the dielectric slab and analyse of the graph of the reflection coefficient in frequency. compared with fdtd results, the numerical results, obtained using the mrtd method, show the directness and conciseness of mrtd as a time - domain method and the advantages in grid enlargement and saving computer resource etc.
最後,第六章討論了mrtd作為時域數值技術最具實際應用價值的邊界條件設置和入射波加入等問題,並給出模擬電磁波傳播過程和介質板反射系數頻譜分析,其數值結果表明了mrtd作為時域方法的直觀簡練,與fdtd方法的結果比較,顯示了其在擴大網格、節省計算資源等方面的優勢。E there is one - to - one map between the mathematical formulation and circuit realization, and that the method is systematic and suited for designing the network function with zeros and high - order filter. at last, the limitation and applied fields of the methods for realizing one - dimension cwt based on state - space log - domain filter are pointed out, it is also proved by the theoretical analysis and calculation results that the methods are suited for synthesizing the wavelet functions with very small scale or the frequence - transloction version of the mother wavelet ( with much translocation in frequence - domain )
論文還給出了用狀態空間對數域濾波器實現一維連續小波函數的限制條件,並指出了這種實現方法的應用范圍,理論分析與計算結果表明該方法適合用於實現尺度很小的小波函數或由原基小波經頻譜搬移(搬移程度較大)后的小波函數。On the basis of previous work, we developed a new data processing system by use of dsp & oop. the new system overcame the problems existed in the old data processing system successfully, such as the bug which cause program dead loop when the data is too long, and the frequency leak due to principle limit of fft filter. in addition, we eliminated the measurement error brought on by phase warp
我們在前人的工作基礎上,利用現代數字信號處理技術和面向對象的軟體開發技術,統一了彈上黑匣子數據處理系統的操作平臺,完善了轉速、掃描角測試數據處理系統,修正了原有處理程序中的因數據長度過長而導致程序死鎖的bug ;利用有限沖擊響應( fir )濾波器,在濾去噪聲的同時,有效地解決了矩形窗fft濾波的頻譜泄漏問題;另外還解決了因相位偏差而導致的測試誤差。分享友人