相似变换

The results show that the frequency characteristic corresponds with vortex structures; the detail and approximate characteristics of signal are reflected by wavelet coefficient at different scales; the coefficient map of continuous wavelet transformation reveals the self-similarity of the signal.

采用傅里叶变换和小波变换技术，实现了混合层密度脉动信号的频谱与多分辨率分析，结果表明：信号的频域特性与流场的涡结构相对应，不同层面的离散小波系数反映了不同尺度下信号与图像的细节和平滑近似特征，连续小波变换系数图定性的反映了信号的自相似特征。

The contourlet transform used in the system was constructed by dual tree complex wavelet transform followed by critically subsampled directional filter banks, sub-bands energy and standard deviations were cascaded to form feature vectors, and the similarity metric was Canberra distance. The performance of retrieval system was compared including original contourlet transform, non-subsampled contourlet transform, semi-subsampled contourlet transform and CCT under the same system structure.

该系统采用的复数轮廓波变换由双树复小波变换级联临界下采样方向滤波器构成，特征向量采用子带系数的能量和标准偏差连接而成，以Canberra距离为相似度度量标准；比较了基于同样架构的基本轮廓波变换、无下采样轮廓波变换、半下采样轮廓波变换和CCT纹理检索系统的性能。

The contourlet transform used in the system was constructed by dual tree complex wavelet transform followed by critically subsampled directional filter banks, sub-bands energy and standard deviations were cascaded to form feature vectors, and the similarity metric was Canberra distance.

该系统采用的复数轮廓波变换由双树复小波变换级联临界下采样方向滤波器构成，特征向量采用子带系数的能量和标准偏差连接而成，以Canberra 距离为相似度度量标准；比较了基于同样架构的基本轮廓波变换、无下采样轮廓波变换、半下采样轮廓波变换和CCT 纹理检索系统的性能。

In the ***, all types and fundamental principles of Radon transform are summarized systematacially. This *** starts from the general linear Radon transform, and then researches how to use the damped least square method to find the solution of the forward transform. However, the least squares smoothing effect will lead to a certain degree of trails in the data of Radon domain, which led to the application\'s limitations. After that the implementation in Radon domain and relative merits of linear Radon transform, parabolic Radon transform and polynomial Radon transform which have time invariance are introduced, the conjugate gradient method that can solve numerical solution is also given. And then the high resolution Randon transform is discussed, it introduces the regularization theory and Bayes principle into inversion, which successfully remove the negative affect caused by discrete Radon transform. Finally, we introduce the optimal weighting similar coefficient Radon transform, which adapt to the time variant quality of hyperbolic Radon transform.

本文系统总结了Radon变换的各种类型及其基本原理，从τ- p变换(即一般线性Radon变换)出发，研究利用阻尼最小二乘平方法求解其正变换，但是最小平方法的平滑作用会导致Radon域数据存在一定程度的拖尾效应，给这种方法的应用带来了很大的局限性；然后先容了具有时不变性的线性、抛物和多项式Radon变换在频率域的实现及其优缺点，给出了求解其数值解的共轭梯度算法；接着讨论了高分辨率Radon变换，它把正则化思想和贝叶斯原理引进到了反演中，很好的克服了离散Radon变换产生的截断效应对结果的不利影响；最后先容了适应双曲Radon变换时变性质的高分辨率最优相似系数加权Radon变换。

This approach was based on the NonSubsampled Contourlet Transform. The means and variables of NSCT coefficients matrix in different subbands and various directions were extracted to form the feature vectors which were regarded as indexes of texture images in image database. Two similarity functions were used to compute the similarity between images. A texture retrieval system based on query image was developed.

该方法利用非下采样Contourlet变换对图像进行分解，提取不同子带和不同方向变换系数矩阵的均值和方差为特征向量，作为数据库中纹理图像的索引，并利用两种不同的相似度函数计算图像之间的相似度，建立了一套基于示例查询图像的纹理图像检索系统。

The results obtained from three different methods—the conventional numerical differentiation, the discrete wavelet transform method and the proposed continuous wavelet transform method were compared, it was demonstrated that the results are similar for signals without noise, but the signal-to-noise ratio of the result obtained by the CWT method is improved greatly comparing with the former two methods for noisy signals.

通过数值微分法、离散小波变换法及连续小波变换法对模拟信号的求导结果表明：对于无噪音的信号，三种方法的结果相似，而对于含有噪音的信号，连续小波变换法所得结果的信噪比明显高于前两种方法。

Especially when dorsiflexion 20 degree goes to dorsiflexion 30 degree ,the contact stress arises 38%; when dorsiflexion 30 degree goes to dorsiflexion 40 degree ,it makes the contact stress arises 32%; when plantar flexion 20 degree goes to plantar flexion 30 degree ,it makes the contact stress arises 62%; when plantar flexion 30 degree goes to plantar flexion 40 degree ,the contact stress arises 23%.

由背屈20度变换成背屈30度时，其接触压力上升38%，由背屈30度变换成背屈40度时，其接触压力上升了32 %；掌屈20度变换成掌屈30度时，其接触压力上升了62%，由掌屈30度变换成掌屈40度时，其接触压力上升了23 %，与文献所载之趋势亦有相似之处。

Besides, by the application of the two kinds of similar Haar wavelet transforms, typical fault signals in power systems are analyzed. It is proved that the two kinds of similar Haar wavelet transforms are very effective methods of the detection of fault signals in power systems.

此外，本文借助于这两种相似Haar小波变换，分析了电力系统几种典型的故障信号，证明了这两种相似小波变换方法对于检测电力系统故障信号是非常有效的。

As compared with other methods, this set of invariants is described in real number.

通常这个识别过程是在相似变换（平移、旋转和按比例放缩）下进行的。

This paper integrates linear affine transformation and nonlinear affine transforma-tion"s approach ability. Integrated affine transformation not only inherits the linear affine transformation"s low bit rate merit,but also inherits the nonlinear affine transformations approach ability.The method proposed in this paper is a new method, and never be proposed in other papers.

本硕士论文综合了线性仿射变换和非线性仿射变换的逼近能力，采用混合型的仿射变换既能发扬线性仿射变换的低比特率的优点，又能发扬非线性仿射变换的相似逼近能力，提高重建质量，本算法是一种新型的算法，文献中尚未提及。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了