fourier spectrum 中文意思是什麼
fourier spectrum
解釋
傅里葉頻譜-
The spectrum characteristics of the phase truncation error and amplitude quantization error are analyzed by the method of fourier series
文章最後還簡單介紹了幾種改善雜散誤差的方法。 -
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。 -
The watermark is embedded in the lpm of fourier magnitude spectrum of the original image, and a small portion of resulting lpm spectrum is used to calculate the watermark positions
在文章中，首先對原始圖像進行傅里葉變換，然後再將數字水印嵌入在該傅里葉變換的幅度頻譜的對數極坐標域。 -
We presented a novel method of searching for similar fragments of 3d curves, with this method, a hash vector is associated with each fixed - length fragments of 3d sherd. each vector consists of low frequence component of fourier - like spectrum for the distance between profile curve and the centroid
討論了基於hash矢量和fourier變換的輪廓曲線匹配方法，在匹配中不要求一段輪廓線與另外一段輪廓線完全匹配，而是把它們分成很多子段，再用這些子段來進行匹配。 -
One is the active fourier telescopy ( afterward named “ aft ” for short ), another is “ spectrum shifting ”
一種是主動式傅立葉望遠術（以下簡稱「 aft 」 ） ，另一種是「頻譜搬移法」 。 -
Omni sampler, the attenuated total reflection accessory of the fourier transform infrared spectrometer, was used to analyze the infrared spectrum of chloride butyl rubber and brominized butyl rubber bottle closures used as medical and pharmaceutical package
摘要採用傅里葉變換紅外光譜儀的衰減全反射附件omni采樣器，對醫藥包裝用氯化丁基橡膠和溴化丁基像膠瓶塞樣品進行了紅外光譜分析。 -
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。 -
In the paper, we describe the whole configuration of the joint transform correlator ; introduce the correlative theories of joint fourier transform in detail ; in order to achieve better correlation result, the nonlinear processing of joint transform power spectrum ( jtps ) is put forward, the effect of jtps laplace sharpening and binary processing to the correlation image is given ; the method of the best binary threshold is determined ; we analyse the correlation image, present the way that removes liquid crystal diffraction spot, direct current spot and image noise, and binarize the correlation image finally
本論文主要對提出的聯合變換相關的整體結構進行了描述；詳細介紹了聯合傅里葉變換的相關理論；為了得到更好的相關結果，本文提出對聯合功率譜進行非線性處理的方法，給出了聯合變換功率譜的拉普拉斯銳化和譜的二值化處理對相關峰圖像的影響及二值化最佳閾值的確定方法；對相關峰圖像信息進行了分析；提出了消除液晶衍射光斑、直流光斑和圖像噪聲的方法；最後對相關峰圖像進行了二值化處理。 -
By means of fourier integral for analysis of plus mag netic field frequency spectrum. it provides relation of magnetic field with maxim um frequency
利用付立葉積分對脈沖磁場進行頻譜分析，討論了脈沖磁場大小隨所選擇頻率上限之間的關系 -
Because massive harmonic interference in the electrical network, it causes signal - sampling to include the very big harmonic in the measurement system, for eliminating measurement result influence by harmonic, the paper has an in - depth study of fourier transformation harmonics analysis measurement principle, analysis the forming reasons of frequency spectrum leakage and railing effect during measurement, achieves phase locked loop and frequency multiplier technique to realize integer - period synchronous sampling and eliminate impact of frequency spectrum leakage and railing effect in the result of measurement, and investigates in depth theory on phase locked loop and frequency multiplier technique, gives the method of realizing phase locked loop and frequency multiplier technique
由於電網中存在大量的諧波干擾，導致測量系統中取樣信號也含有很大的諧波，為了消除諧波對測量結果的影響，論文深入研究了傅立葉變換諧波分析法的測量原理，分析了測量中頻譜泄漏和柵欄效應形成的原因，提出了採用鎖相環倍頻技術實現信號的整周期同步采樣，消除頻譜泄漏和柵欄效應對測量結果的影響，並對鎖相環倍頻技術的理論進行了深入研究，給出鎖相環倍頻技術的實現方法。 -
Then, based on the theory of discrete fourier transform, discrete cosine transform and discrete wavelet transform, two invisible image watermarking schemes in transform domain are proposed, one is circular symmetric spread spectrum digital image watermarking based on chaotic sequences, the other is the hybrid image watermarking based on wavelet decomposition and discrete cosine transform. finally, the good performance of the two algorithms is verified by some common image processing and attack experiments
在分析了dft 、 dct 、 dwt的理論與演算法的基礎上，提出了兩種基於變換域的圖像隱形水印方案? ?基於混沌序列的圓對稱擴頻水印方案和基於小波分解和餘弦變換結合的水印方案，並通過一些常見的圖像處理及攻擊實驗驗證了這兩種演算法生成水印的性能。 -
The results show that the self - adaptive filter can be used to detect line spectrum, the wavelet transform and the fourier transform can be used to detect the ship noise in modulating the anisotropic noise field
結果表明：自適應濾波對于各向異性噪聲場中的線譜檢測有良好的效果；而小波變換和短時傅里葉變換對各向異性噪聲場中的艦船噪聲調制信號檢測有良好的效果。 -
Used fourier transforming the nuclear logs, its vertical resolution can be achieved from analyzing the changes of amplitude spectrum slope
摘要對核測井曲線進行付氏變換，其縱向解析度可以從分析振幅譜斜率變化中獲得。 -
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。 -
After the comparison of the merits and faults between fourier spectrum analysis method and wavelet - neural network analysis method, the latter is selected. after the research on the principle of accuracy - loss diagnosis of the dynamic measurement, the diagnosis theory and method are advanced. according to the error model established of the dynamic system and the results of the error tracing, using bp neural network, the accuracy - loss law of each inner unit is acknowledged
對于實際進行誤差分解與溯源的信號處理方法，在比較了譜分析方法與小波神經網路分析方法的優缺點之後，指出譜分析方法的分解結果不夠理想，並最終確定用小波神經網路來進行實際測量系統的誤差分解與溯源。 -
Simulation of wind field based on stochastic fourier spectrum
譜的風場模擬 -
Lastly, aiming at the poor results which all current algorithms do for directional textures, and cannot synthesis texture directly, aiming at the particularity of this kind of textures, we bring forward the conceptions of non frontal parallel textures and frontal parallel textures. by analyzing texture ' s direction through fourier spectrum, we introduce the conception of main direction, and solve the approximation value of texture ' s main direction by discrete approximated approach. by this way, we can synthesis indirectly simple structural non frontal parallel textures
最後針對現有演算法對帶有方向的紋理合成效果差，無法直接合成紋理圖像的難點，本論文首先提出了非正平行紋理與正平行紋理的概念，分析了它們之間的內在聯系，引入了兩個角度參數來描述紋理的朝向，採用傅立葉頻譜法分析紋理的方向特性，並提出了紋理主方向的概念，本論文引入離散逼近的方法來求解出紋理主方向的近似值，這樣我們就能用一種間接的方法合成簡單的結構性非正平行紋理。 -
Some characters and fourier spectrum characters of the almost perfect autocorrelation sequence pairs are discussed, and the necessary conditions of existences of the almost perfect auto - correlation sequence pairs are given
其次，提出了幾乎最佳自相關序列偶的理論，它是幾乎最佳自相關序列的深入和發展，探討了它的性質，譜特性，存在的必要條件。 -
2 ) fourier amplitude spectrum analysis : ( 1 ) the fourier amplitude spectra decrease with the increment of depth ; and the components of fourier spectrum become complex in near - surface. ( 2 ) the fourier amplitude decrease faster in shallow soil level, and smaller in deep soil level. ( 3 ) compared with the deepest bedrock fourier spectrum, spectral components of higher than 5 hz decrease with depth decrease
2 .地震動傅立葉振幅譜沿深度的變化規律（ d隨著深度的增大，傅氏譜振幅逐漸減小;越接近地表傅氏譜的頻譜成份越多，形狀越復雜;傅氏譜振幅值在淺層沿深度的下降梯度較大，在深層下降較小; 「土層/基巖」場地的基巖內_匕下兩測點的地震動頻譜沿深度幾乎不變，傅氏譜十分相似; d基巖以上的土層測點，高於shz的高頻成分減少。 -
These are correlation characteristic parameter, fourier spectrum characteristic parameter, power spectrum characteristic parameter, time domain amplitude characteristic parameter, linear prediction coding coefficients, instantaneous characteristic parameter, absorb and decay coefficient, velocity characteristic parameter and wavelet packet transform characteristic parameter. the parameters contain the surface relatively wide, the prediction which is suitable for the goal of many kinds of seism needs
分別為：自相關特徵參數、付立葉譜特徵參數、功率譜特徵參數、時域振幅特徵參數、線性預測編碼系數、瞬時特徵參數、吸收衰減系數、速度類特徵參數和小波包變換特徵參數，參數涵蓋面較寬，適用於多種地質目標的預測需要。
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