fast fourier transform 中文意思是什麼

fast fourier transform 解釋
快速傅立葉變換
  • fast : adj 1 緊 (opp loose), 牢實的,堅牢的,粘得緊的,堅固的;固定的。2 忠實的,可靠的。3 耐久的;不...
  • fourier : n 1 傅立葉〈姓氏〉。2 Francois Marie Charles Fourier 弗朗瓦斯馬利沙利傅立葉〈1772 1837,法國空想...
  • transform : vt (使)變形;(使)變化[轉化,轉變];變態,改變(性質、機能等),改造,改革;【數學】變換;【電...
  1. We use fast fourier transform arithmetic to calculate two seriate images. this article discusses the basic principle of the cross - correlation arithmetic in detail, discuss each stage of its produce and development and also discuss the thinking, the merit and the defect of each algorithm. based on these discusses, we confirm our algorithm and realize it in programming with c + +

    粒子圖像的匹配演算法的主要運算是將兩連續的視頻圖像進行基於快速傅里葉變換的互相關運算,本文詳細論述了相關演算法的基本原理,它的產生和發展的各個階段,在比較了各種演算法的基礎上確立了自己的演算法並以c + +編程實現。
  2. The subregion with pure dielectric layers is analyzed by mol and the fast fourier transform ( fft ) is introduced to reduce the computing time, while the subregion with conductors is analyzed by fdfd to take advantage fully the superiorities of these two methods

    通過在純介質區域使用直線法,導體所在區域使用有限差分法分別進行求解,充分發揮兩種方法各自的優越性。由於在純介質區域中使用了直線法求解,因此該演算法具有計算時間與介質層厚度無關的突出優越性。
  3. At present, the typic harmful current detection methods are the fast fourier transform algorithm in frequency domain and methods based on the instantaneous reactive power theory, these methods all require some transform and quick, real - time calculating, so high precision analog multipliers or high speed dsp chip with fast a / d are needed, this results in complex circuit and high cost , which have restricted the development of apf

    目前畸變電流檢測常用的方法有頻域法的fft和基於瞬時無功理論的畸變電流檢測法。這些方法均有一定的變換,需要快速、實時運算,因此必須使用高速的數字微處理器和高性能a / d轉換器,這必將大大提高系統成本,使得電路結構復雜,在一定程度上限制了有源濾波器的發展。
  4. In this time, as a result of major development in computer technologies and fast fourier transform wider application, many frequency analyzer based on digital signal processing theory and multi - function signal analysis software occurred. which greatly strengthened analysis function to engineer vibration signal ' s time field and frequency field

    在這一時期,由於計算機的快速發展以及快速傅立葉變換的普遍應用,各種基於數字信號處理原理的頻率分析儀以及多功能信號分析軟體出現,從而大大加強了對工程振動信號的時域及頻域分析功能。
  5. In order to investigate the unsteady flow frequency domain performances of an axial flow compressor at different mass flow, rotating speed and blade row spacing, plus inlet flow distortion, and considering aerodynamic characteristics and stability of the compressor, the low speed research compressor ( lsc ) at college of energy and power in nuaa is used to carry out the experiment studies. a large amount of test data has been gained through dynamic pressure transducers embedded in the stator blades at the tip, middle and hub section, then fast fourier transform algorithm ( fft ) is applied to calculate the frequency data

    為探討軸流壓氣機在工作流量、工作轉速及動?靜葉排軸向間距變化時的葉片排流場非定常頻譜特性變化規律,並耦合進氣畸變的影響,同時與壓氣機氣動性能和氣動穩定性相關聯,作者利用南京航空航天大學能源與動力學院的低速大尺寸軸流壓氣機( lsc )試驗器,採取在靜子葉片表面埋入動態壓力傳感器的實驗方法,對葉尖、葉中和葉根三個截面的動態壓力進行了測量,獲得了大量的可靠的實驗數據。
  6. 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。
  7. Fft fast fourier transform

    快速熱歐姆轉換
  8. In addition, based on fast fourier transform ( fft ), an effective and reliable carrier frequency detection method has also been designed in this thesis

    此外,論文還設計了一種有效可靠的基於fft的載波頻率測量方法。
  9. In this paper, we firstly design orientation filters based on directional image of fingerprint and employ them to denoise gray - scale image. then, we binarize the gray - scale image with local self - adaptive binarization smoothness algorithm and eliminate the noises from the binary image with fast fourier transform algorithm

    本文先基於指紋的方向圖設計出方向濾波器對原圖像進行濾波去噪,然後使用局部平滑閾值自適應二值化演算法,將灰度圖像進行二值化,並採用快速傅氏變換對所得到的二值化圖像進行去噪處理。
  10. At first, the thesis discusses the hardware implementing arithmetic of fast fourier transform ( fft ) and some correlative problems need to be solved. and according to the thesis " design demand and characteristic of large - scale programmable logic device ( pld ), the thesis designs an implementing scheme of fft processing machine based on pld

    首先,論文研究了快速傅立葉變換( fft )的硬體實現方法以及有限字長效應等問題,並根據論文的設計要求和大規模可編程邏輯器件的特點,設計了一個基於可編程邏輯器件的fft處理機實現方案。
  11. The digitizer based on pxi bus uses fpga ( field programmable gate array ) to implement 256 points, radix - 2 dit fft ( fast fourier transform algorithm ). the design uses pipelining for fft processing and can accomplish sampling and processing signals of two channels at the same time. in the signal acquisition circuit, - a / d convector is used to enhance the precision of the signal sampling

    在本設計中,採用fpga ( fieldprogrammablegatearray )實現了256點基2dit演算法復數fft ( fastfouriertransformalgorithm快速傅氏變換演算法)處理器,具有較高的速度和運算精度fft ,設計採用流水線處理方式大大的提高了處理速度,可實現對兩個通道輸入信號的并行採集與處理。
  12. The numerical method based on the coupling of the finite difference method in time domain with the discrete fast fourier transform is applied to calculate the first four eigenfrequencies and eigenfunctions of the six - cavity with open boundary. the absorbing boundary condition for tem wave is tested numerically, and it is applied to writing the code. the cold testing of the cavity is done and the results are good agreement with the numerical results

    計算x波段六腔開放腔前四個模式的場分佈;根據第二章公式分別計算x波段六腔開放腔前四個模式的電子負載電導並總結了這四種工作模式渡越效應的規律,基於這種小信號理論分析了x波段渡越輻射振蕩器,得到了工作模式及可能產生的模式競爭。
  13. A fast fourier transform algorithm to estimate carrier frequency deviation

    快速傅里葉變換載波頻偏估計演算法
  14. So power systems harmonic analysis is a significant aspect of power systems research. power system harmonic analysis was realized usually with fast fourier transform ( fft ), but the method exits spectrum leakage, and can not analyse all harmonic parameters exactly, such as frequency, amplitude and phase, in particular has big phase error

    電力系統諧波分析通常都是通過快速傅立葉變換( fft )實現的,但是這種方法存在柵欄效應和頻譜泄漏,使計算出的諧波參數即頻率、幅值和相位不準,尤其是相位誤差很大,無法滿足準確的諧波測量要求。
  15. Three methods of digital signal processing algorithm are proposed to restrain the noise discussed, there are methods of fast fourier transform ( fft ), of moving self - correlation, and of least means

    這樣,就可以在周期性和相關性上,區分這兩類信號,並消除干擾。在此基礎上,在數字信號處理方面,本文提出了三種演算法用於抑制上述干擾。
  16. Each channel has independent synchronization and two powerful digital signal processing chips. one chip performs all the synchronization and sampling computations, while the other does the fast fourier transform of current and voltage signals sampled with 18 bit resolution. both current and voltage have separate but fully synchronized a d waveform capture sections

    就信號分析能力而言, 2503ah系列的最大特點是速度和精度,各通道均獨立同步及擁有兩片數字信號處理器晶元,當一晶元執行全部同步與取樣運算時,另一晶元則為已取樣的電流與電壓信號以真實18位解析度進行速傳立葉變換,電流與電壓具分離但完全同步的a d波形捕捉部份
  17. Among the different imaging algorithms, the range - doppler fft ( r - d fft ) algorithm, based on range - doppler theory, in which the fast fourier transform ( fft ) is employed to reduce compute burden, is widely used in various imaging radar because it can be easily realized in real - time application

    陸基成像雷達( gbr )作為isar成像技術的重要應用,其觀測目標具有速度快,慣性大,運動相對平穩等特點,針對這些特點,本文對isar成像運動補償方面作了較為深入的研究。
  18. It deduces the interpolation formula of simultaneous sampling datum calculated by the asimultaneous sampling datum and uses fast fourier transform ( fft ) technology to calculate harmonic parameters. in the end, it gives harmonic errors " datum and curves by means of math model and computer simulation

    在此基礎上,導出了用非同步采樣數據計算同步采樣數據的插值公式,並根據復序列快速傅立葉變換( fft )原理對插值后的采樣數據進行分析和計算,從而得到電網諧波參數。
  19. A coherent electromagnetic pulse in the range between the far - infrared and microwave region is used as a detection source. the amplitude of the wave is recorded by electro - optical or photoconductive sampling. after fast fourier transform, the amplitude and phase of the wave is given, then the complex refractive index standing for the absorption and dispersion of the material in thz region is extracted

    Thz ( 10 ~ ( 12 ) hz )時域光譜技術是20世紀90年代發展起來的一種新型的光譜測量技術,它使用頻率介於遠紅外和微波之間的相干電磁輻射脈沖作為探測源,利用電光取樣或光電導取樣的方法直接記錄thz輻射電場的振幅時間波形,通過傅立葉變換得到測量信號振幅和相位的光譜分佈,進而獲得材料在thz波段的復介電常數,即色散及吸收等信息。
  20. The traditional beam propagation algorithm based on fast fourier transform fails to give right results due to the limitation of the sampling theorem

    由於取樣定理的限制,常規的基於快速傅里葉變換( fft )光束傳輸模擬演算法不能進行任意焦距聚焦光束的傳輸過程的模擬。
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