查询词典 wavelet

By making up of time-frequency local property and multi-scale analytical capability of wavelet transformation and self-learning and prediction function of artificial neural network,chapter three develops a prediction model loose combining wavelet analysis and Radial Basis Functionsneural network,abbreviated as Wavelet-RBFNN.

第三章利用小波变换的时频局域化特性和多尺度分析能力及神经网络的自学习、预测功能，通过小波分析与神经网络的松散型结合方式，建立小波分析和径向基函数神经网络(Wavelet-RBFNN)预测模型。

On the basis of wavelet transform and S transform,through popularizing basic wavelet, the basic wavelet containing 4 kinds of unknown parameters (amplitude, energy attenuation rate, energy-delay time and apparent frequency ) was constructed, realizing generalized S transform.

在小波变换和S变换基础上，通过对基本小波的推广，构建含有四类待定参数(振幅、能量衰减率、能量延迟时间及视频率)的基本小波，实现广义S变换。

The main theory results includes:(1) Using the properties of Hilbert transform, perfectly reconstruction and new type of lifting scheme, a new type of dual-tree binary coefficients complex wavelet with linear phase is achieved.(2) For linear systems that can be diagonalized by GFT and DST-II matrices, an efficient MGM method is proposed, convergence is proved.(3) We discuss the algebraic structure when Toeplitz matrix is transformed by multi-band wavelet,show that Toeplitz matrix is composed of generating function is transformed to a band and sparse matrix when wavelet applied to this matrix, based on the above results, an efficient solution of Toeplitz equations is obtained, and the computational complex is O,where N is the order of matrix.

理论成果主要包括：(1)对于对偶树二进制系数复数小波，利用Hilbert变换对性质、完全重构条件并结合新的提升格式构造研究了含参系数多进制小波构造方法，作为特例得到具有线性相位的对偶树二进制系数复数小波构造方法；(2)对于广义离散傅立叶变换与正弦变换对角化系统，提出了高效、快速的多重网格算法，理论上证明了算法的收敛性；(3)研究了Toeplitz矩阵在多进制小波变换下的代数结构，验证了多项式生成函数构成的Toeplitz系统在小波变换下的稀疏带宽性质，从而建立基于小波变换求解Toeplitz系统的快速求解方法，运算量级控制在O，其中N为系统的阶。

Experiment results show that binary tree SPIHT suits to true bidimensional wavelet decomposition and it is testified that in true bidimensional wavelet decomposition, the compression effect is comparable between image decomposed by wavelet FB with low order VMs but good interpolating characteristic and that with higher order VMs.

实验证实了二叉树的编码更适合纯二维小波分解，同时也证实了在纯二维小波分解中内插性能好的低阶消失矩的小波滤波器能够产生与高阶消失矩的小波滤波器相同或更好的压缩效果。

By use of bipartition, the entropy of each wavelet block approximates to the target bit rate of one. 5. An efficient algorithm is presented for constructing quantization tables of wavelet blocks with optimal bit allocations for a given image. The algorithm uses wavelet coefficient distribution statistics in a novel way, and pays attention to the traits of HVS.

该算法首先根据每个小波块所含能量的多少和到每个小波块实际编码所用的比特数，给其分配不同的码率；然后根据二分法，通过调整各小波块的量化因子使得各小波块的熵逼近它的目标比特率。

When seismic wavelet is in non-minimum phase , we can make it have smaller phase by doing exponential weighting . As for nonwhite noise problem of reflection coefficient , we may employ logarithmic power spectrum to estimate the autocorrelation function of seismic wavelet , then obtain seismic wavelet and deconvolution opera .

当地震子波为非最小相位时，可利用指数加权方法使之小相位化；对于反射系数非白噪声问题，本文提出利用对数功率谱来估算地震子波的自相关函数进而求取地震子波以及反褶积算子的方法；对于理想的期望子波，本文采用"宽带雷克子波"作为期望输出子波。

Second, analyzing principle of the singular value decomposition and the principle of wavelet transform deeply at all levels, as well as the impact to image processing and singular value decomposition wavelet analyzing, focus on single watermarking and double watermarking algorithm based on the discrete wavelet transform.

其次，深入分析了奇异值分解的原理和小波变换的原理以及图像处理对各级小波分解和奇异值分析的影响等，重点研究了基于离散小波变换的单水印和双水印算法。

Objective To study the power spectrum density of blood flow ultrasonic Doppler signal using wavelet analysis. Method Doppler signal of blood flow in human common carotid artery was studied with wavelet scalogram analysis, an affine smoothing Wigner Ville transform with a constant "Q" character. Result Wavelet scalogram of blood flow ultrasonic signal had a higher distinguishability than STFT spectrogram in the low frequency portion, but had poorer decussation terms than spectrogram.

对于平稳信号的处理工具仍然是Fourier变换，但是，在实际应用中的绝大多数信号是非平稳的，现在看来处理非平稳信号的主要工具将是小波变换，这主要是因为传统的Fourier变换分析信号时，时间和频率分辨率精度是固定不变的，而利用小波变换分析信号，在信号高频段时间分辨率精度也较高，在信号低频段频率分辨率精度较高，这很符合非平稳信号的特点。

The paper analyses the blood pressure signal with the theory of wavelet and fuzzy recognition. The characters of useful signal are extracted by transform of discrete wavelet and series wavelet and are recognized by the method of fuzzy recognition.

本文首次将小波理论和模糊识别理论相结合，并应用于人体血压波形信号的实际分析中；创造性地将离散小波和连续小波变换结合在一起，完成有用信号的特征提取，并用模糊识别的方法实现目标的识别。

In this paper, a speckle reduction method for SAR images based on Dual Tree Complex Wavelet Transform is proposed. It first presumes the probability distribution function for complex wavelet coefficients of the original nature image, and then applies MAP theory to estimate coefficients from the noisy wavelet coefficients. Filtered image can be derived after inversed DTCWT.

该方法首先对无噪声污染图像的复数小波系数的统计概率分布进行建模；然后利用此先验概率模型，采用最大后验概率方法从含噪小波系数中估计出无噪声污染的小波系数：最后经重构得到滤波后的图像。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。