fourier coefficients 中文意思是什麼

fourier coefficients 解釋
傅立葉系數
  • 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...
  • coefficients : 系數
  1. One is to use fourier transformation to convert the source signal from time domain to frequency domain and to discard high frequency harmonious components upwards of 19 ( gb / t14953 - 93 d5. 3 demanding ), then to have static huffman coding to the quantized char array which is composed of reserved direct current component and basic wave and each high frequency " s amplitudes and angles. the other is to use discrete wavelet transformation to convert the source signal from time domain to frequency domain and to set the high frequency coefficients that its absolute value is smaller than the given threshold to zero, then to have dynamic huffman coding to the quantized char array which is composed of multiple, wavelet ' s level, datum length, low frequency coefficients and reserved high frequency coefficients. mass simulinks and analyses under the two circumstances have done to show that data compression ratio is small and the relative error is also small and within the permission of engineering and the compression problem can be solved in theory of measured datum of power system

    第一種情況的壓縮方法為：採用傳統的傅立葉變換把原始信號從時間域變換到頻率域，舍棄20次及其以上的高次諧波成分（保證了gb / t14953 ? 93d5 . 3要求） ，然後對保留的直流分量、基波和各次諧波的幅值和相角數據量化后和量化時分別乘以的倍數系數構成一個數組，以字元形式保存，採用靜態huffman編碼對變換數據進行壓縮；採用離散小波變換把原始信號從時間域變換到頻率域，然後對分解得到的高頻系數進行閾值量化處理，對乘以的倍數系數、小波變換的階數、小波變換后的低頻、各級高頻以及原始數據長度、量化后的低頻系數以及保留的高頻系數大小、位置構成一個數組，以字元形式保存，採用動態huffman編碼對這個文件進行壓縮。
  2. When studying the basis expansion approach, a new scheme utilizing pilot signals is proposed, which takes full advantage of high processing gain of dpcch. utilizing fourier transform, the frequencies and the coefficients of basis can be estimated

    在基展開方法中，充分利用對dpcch解擴后的系統處理增益為24db的優點，結合基展開的思路，提出了基於基展開的通道非盲估計。
  3. Though the two new methods can improve the effect of edge detection, they need the gabor and wavelet transforms which make the computation complex and cost much time and are not easy to used in real - time application. this paper presents an efficient fast approach to compute real discrete gabor coefficients by applying the fht ( fast hartley transform ) in gabor transform, also the fft ( fast fourier transform ) is proposed to used in compute the wavelet coefficients

    雖然gabor和小波的引入能提高邊緣檢測的效果，但往往因其計算的復雜性而受到限制，本文提出了一種有效的離散gabor變換演算法來計算有限離散實數信號的gabor系數，同時，也給出了基於fft的小波變換快速演算法，為理論的快速實現提供了可能性。
  4. 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。
  5. I carried my research on both the two computation methods and fruitful results were obtained. for the fdtd method, i solved the instability problem of the method in the non - orthogonal coordinate system. for the pwe method, i introduce the linear transform in to calculate analytically the fourier coefficients of complicated photonic crystals

    對于有限時域差分方法，我解決了一個影響這種方法在斜坐標使用的穩定性問題，得到了傳統的yee型差分在斜坐標里的擴充；對于平面波展開方法，我引入了線性變化求富里葉展開的系數，這種方法的好處可以很方便快捷的獲得復雜光子晶體的富里葉系數。
  6. Firstly, fourier descriptor used to describe the object ' s shape is introduced to the extraction of feature of apple ' s shape. the boundary of apple is an obturated curve, distance between boundary point and centroid r ( k ) " is used as a function to express the 2 - d boundary in spatial domain. the fourier transform coefficients of the discrete sequences f ( h ) are spectrum values in frequency domain, and they compose feature parameters of shape

    首次將圖像分析理論中對形狀的傅立葉描述方法引入到對蘋果形狀的特徵提取中，果實邊界是一條封閉曲線，用邊界點到形心之間的距離長度r （ l ）作為空域中對二維曲線的表達函數，離散的函數值序列r （ k ） ~ l的離散傅立葉變換系數f （ h ）就是頻域中得到的頻譜值，可作為形狀的特徵參數。
  7. Due to complicated continuous helicopter models and a wide range of constraints, numerical solutions on a mainframe computer have to take a long time. for a given set of initial helicopter states and flight parameters, optimal solutions are fitted by a fourier series. the coefficients of the fourier approximations are then interpolated as functions built by three - layer bp network with inputs of initial flight states and parameters

    最後，由於直升機數學模型的復雜性，這給實時優化計算帶來很大困難，本文研究了地面計算機計算的最優軌跡如何在機載計算機上實時顯示，對飛行員的操縱提供參考，即把不同初始條件得到的最優軌跡曲線進行傅立葉部分級數化，得到傅立葉系數，選取合適初始條件作為變量，對這些最優軌跡曲線進行擬和，建立bp神經網路預測模型。
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