变换

Thismethod adopted affine transformation model and a Lie derivative-based analytical algorithm.We introduced the process and characters in extracting information of biological visionsystem, studied the feasibility of the generalized Gabor function used as receptive fieldfunction in extracting information and analyzed affine transformation group and Liederivatives. Finally, we deduced the mathematical denotation for Lie derivatives, i.e. theinfinitesimal generator of the geometric distortion in affine transformation.

对生物视觉信息提取的过程及特点进行了介绍，其中主要研究了广义Gabor函数作为感受野函数提取初级视觉信息的可行性；对仿射变换作为外界图像信息在视觉成像系统上的投影模型的原理进行了初步讨论；对Lie变换群微分算子用于提取仿射变换不变量的分析方法作了剖析，并推导了该方法中关键部分——仿射变换Lie微分算子的具体表达式，也就是几何变形无限小微分算子的计算表达式，使下一步编程实现该方法成为可能。

The image registration firstly assumes that there is some transformation between frame and frame of images, such as translation, affine and planar surface etc. and then registers images.

图象配准算法首先假设图象帧间存在某些变换，例如平移变换、仿射变换和平面变换等，然后对序列图象进行运动配准。

Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.

在此基础上，(1)结合连续小波变换的特点和卷积的微分性质，提出了使用Gaussian函数的一阶和二阶导数，Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法，与其他导数计算方法(包括数字微分法，多项式滤波法，Fourier变换法和离散小波变换法)相比，本法简单便捷，计算速度快，对于噪声含量较高的信号(S/N为5)，只要适当调节尺度即可获得比较满意的结果。

Experiment proved the practicability and efficiency of this algorithm. We study a class of subband coding schemes allowing perfect reconstruction for a bidimensional signal sampled on the hexagonal grid.

辨析了张量积子波变换与六边形子波变换的特性，尤其是空间取向性的差异，六边形子波变换克服了张量积子波变换在频率域上的"某些方向不确定性问题"，提供了频率域上的尖角分解准理想模式。

The converter can be improved just by exchanging the position of the resonant inductance and the transformer such that the transformer is connected with the lagging leg. The improved converter has several advantages over its counterpart, e.g., the clamping diodes conduct only once in a switching period, and the resonant inductance current is smaller in zero state, leading to a higher efficiency and reduced duty cycle loss. The operation principle of the improved converter and the comparison with the original converter are analyzed in this paper. The effect of the blocking capacitor in series with the transformer or resonant inductance is discussed, and a best scheme is determined.The improved converter is adopted to design the DC/DC converter of secondary power supply in HVDC power system.

本文将谐振电感和变压器交换位置，使变压器与滞后桥臂相连，这样箝位二极管在一个开关周期中只导通一次，同时零状态时谐振电感电流较小，有利于提高变换效率和减小占空比丢失，本文分析改进后变换器的工作原理，并与改进前的变换器进行对比，讨论隔直电容在不同位置对变换器工作的影响，确定一种最佳工程方案。

In the second part, we make the study of the application of Z-transformation when we solve linear difference equation bearing constant coefficient and transmission function in pulsing system.

第2部分："Z变换的应用"，主要通过上1章研究的Z－变换的逆变换和10个性质定理，研究了Z－变换在求解具有常系数的线性差分方程和脉冲系统的传递函数方面的应用。

It is found and emphasized in the paper that the complete form of differential and integral characteristic theorem automatically incorporates the shift properties in both the frequency and time domains, as well as other important properties of Fourier transform, and so it plays an important role in Fourier transform.

并强调了完整形式的微积特性定理自动地包括了Fourier变换的"频移特性"、"时延特性"等其它的重要特性，因此它在Fourier变换中具有基本的重要意义。关键词：Fourier变换微积特性，Fourier变换的极限定义式，冲激型广义函数，频移特性等

Schwartz mapped the interior of each fluid cycle in the physical plane into an annulus of unit outer radius in the mapping plane according to the conformal transformation. And the perturbation theory is the main way of solving conformal parameters.

L.W.Schwartz的关于定常二维非线性波算法的主要思想是为了利用已知速度势的解析解，将一个波长的自由表面同底部所限定的流域采用合适的保角变换函数变换为映射平面上一圆环，在求解保角变换函数的变换系数时采用摄动理论进行求解。

We transformed eccentric coaxial line cross-section into rectangular area by hyperbolic cotangent transformation, transformed the FDTD difference expressions into CM-FDTD difference formula, calculated the cutoff wavenumbers of higher order TE and TM modes in eccentric coaxial line.

本文用双曲余切变换将偏心同轴线截面变换为矩形区域，相应地将FDTD差分格式变换为保角变换FDTD差分格式，计算了偏心同轴线TE、TM高阶模的截止波长。

This circuit can be widely used in other topology, such as flyback converter, half bridge converter, full bridge converter and push-pull converter with synchronous rectifier.

这个电路可以推广到其他隔离变换器的拓扑中，如反激变换器同步整流、半桥变换器同步整流、全桥变换器同步整流和推挽变换器同步整流。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。