变换的

I am delighted to have cool waters of a brook rush

对我来说四季变换的景色如同一场

This transformation is particularly useful for the research on wave propagation in acoustic waveguide.

结果表明这种方法优于基于小波变换的降噪方法，特别是在低信噪比情况下。

In this paper,translation, rotation and scale properties of 2-D affine transformation are discussed.

文中讨论了二维仿射变换的平移、旋转和缩放等特性。

The study has focused on: 1 The research background and the current state of the power measurement were analyzed systematically, and then wavelet-based power measurement algorithm was certified feasible for astable signals; 2 We developed a new method of RMS and power measurement based on Dmeyer wavelet. After that three other wavelet measurement approaches were compared with Dmeyer wavelet-based measurement approach. Then the impact on measurement errors of amplitude frequency property and energy leakage of wavelet filter banks were deeply researched, and some measures were proposed to reduce it; 3 We developed a new strategy of power measurement algorithm based on lifting wavelet, which had calculation advantage compared with the first wavelet, so that it was more suitable for the realization of hardware; 4 The running system of wavelet-based power measurement algorithm based on DSP was proposed, and then it was realized on ICETEK-VC5416-A EVM board; 5 Existing problems and the further research direction of wavelet-based power sub-band measurement algorithm was discussed.

本文对基于小波变换的功率测量算法展开深入的分析研究，主要内容有：1）系统地分析了功率分解测量的研究背景、国内外的研究现状，并从能量守恒的角度验证了小波功率分频带测量算法在非平稳信号条件下的可行性；2）首次提出了Dmeyer小波变换有效值与功率的测量方法，进而通过对该方法与3种已经提出的小波测量方法的对比分析，深入研究了小波滤波器组的幅频特性和能量泄漏特性对测量误差的影响，并针对电网谐波的特点提出了减小影响的相关措施；3）首次提出了二代小波功率测量算法，对比一代小波功率分频带测量算法，它大大减少了算法实现的运算量及内存的需求量，从而更适合于硬件的实时实现；4）提出了小波功率分频带测量算法的DSP实现方案，并在ICETEK-VC5416-A EVM板上进行了实现；5）探讨了小波功率分频带测量算法目前仍存在的问题，并提出了进一步的研究方向。

This paper combines with pipeline delivery of our countrys actual conditions and other methods of detection and location. To the leakage characteristic of the fault to the long-distance natural gas pipeline, a method is raised, which is on the basis of wavelet and negative-pressure-wave to detect the leakage and locate. Jobs in this paper are as follows:Multi-resolution decomposition and reconstruction of wavelet transform is utilized to filter the noises, which the leakage brings the noises of negative-pressure-wave. The research is worked in the wavelet and wavelet packet filter. The wavelet transform have a fast and accurate recognition capability to signal singularity. This paper chooses wavelet technology to catch the break point of pressure signal.

本文结合我国管道输送的实际情况和目前现有的各种泄漏检测与定位方法，针对天然气长输管线泄漏故障的特点，提出了基于小波分析和负压波相结合的方法检测泄漏并定位，其中主要进行了以下几个方面的工作：利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行降噪处理，并对小波及小波包优化的降噪效果进行对比性研究；利用小波变换技术对信号奇异点的快速、准确的识别能力，捕捉负压波信号的突变点，从而判断是否有泄漏发生。

The book is divided into 14 chapters, including Introduction, continuous control system theory, process and discrete sampling, Z transform, sampled-data systems, discrete approximation of continuous system the equivalent, based on mathematical transform the classical design method, based on state space pole placement design methodology, multi-variable system of quadratic optimal control, quantitative effects, the choice of sampling period, the digital control system modeling, digital control system for a variety of design methods, variables quadratic optimal control systems, sampling cycle of selection, non-linear control of the problem, as well as digital control system, a typical application - Disk drive servo control design.

全书共分14章，内容包括概论、连续控制系统理论、采样过程和离散化、Z变换、采样数据系统、连续系统的近似离散等效、基于数学变换的经典设计方法、基于状态空间的极点配置设计方法、多变量系统的二次型最优控制、量化效应、采样周期的选择、数字控制系统的建模问题、数字控制系统的各种设计方法、变量系统的二次型最优控制、采样周期的选择、非线性控制的有关问题，以及数字控制系统的一个典型应用——磁盘驱动器的伺服控制设计等。

Due to its good effect in the reservation of information of signal abrupt change, mathematical morphology is often applied in the detection and location of short-term power quality disturbance, however, there is still a defect of invalid detection existing in partial detection methods based on mathematical morphology while some zero-crossing disturbances are detected. In this paper three mathematical morphology based disturbance detection and location methods, i.e., the method based on first-order derivation and morphological gradient, the method based on morphological gradient and soft threshold processing and the method based on dq decomposition and top-hat transform, are analyzed, that is, by means of simulation the adaptability of these methods in the analysis on the signals of voltage sag, voltage swell and electromagnetic transient oscillation is compared.

数学形态学因其在保留信号突变点信息方面有很好的效果，因此常用于短时电能质量扰动的检测和定位，但基于数学形态学的部分方法仍存在对某些过零点扰动检测失效的缺点，文章分析了3种基于数学形态学的扰动检测和定位方法，即基于1阶求导和形态梯度的方法、基于形态梯度和软阈值处理的方法、基于dq分解和高帽变换的方法，通过仿真比较了3种方法在分析电压暂降、电压暂升、电磁暂态振荡等信号方面的适应性，结果发现基于dq分解和高帽变换的方法在检测过零点扰动时具有很好的效果，因此选取这种方法对实测扰动数据进行了检测和定位分析。

But , when we changeour trainofthought , we can find that sometimes using mathematical Analysis is a better solution to the linear algebraic problems.In thispaper, use the propertyofcontinuous function andimproper integralof infinite interval and to solve some matrix and quadratic form problems.Algebraic ideas andmethodstosolvemathematical analysisproblems are indicated by several specific examples. Close contactof differentmathematical analysis fields is shown.

该文探讨运用数学分析的有关知识（如：函数连续性、无穷区间的广义积分）和方法解决高等代数中的某些复杂、繁琐的问题；通过具体的实例，阐述高等代数的思想和方法在解决数学分析问题中的作用，揭示不同的数学领域之间的密切联系，例如：二次型与正交变换是代数学的基本内容，其用途十分广泛，而重积分的计算往往存在技术性的困难，若利用"二次型"与"正交变换"的有关理论去解决某些重积分的计算问题是颇有功效的。

The computational complexity has been reduced about 5 times over against the original one. Moreover, the interpolation and quantization processing of CW is more reasonable; 2. A secondary power normalization algorithm is proposed in this dissertation. This normalization algorithm ensures that the energy sum of SEW and REW is 1. So, the energy ratio of SEW and REW can be achieved only by using SEW energy. This ratio is applied in REW quantization and CW composition; 3. For more efficient quantization for Slowly Evolving Waveform magnitude, Rapidly Evolving Waveform magnitude and power parameters, firstly, by applying the Equivalent Rectangular Bandwidth theory, classifiable multi-codebooks method, analysis-by-synthesis approach and so on, a predictive AbS multi-codebooks SEW magnitude quantization scheme is proposed. In the scheme, pitch information is exploited to determine which codebook is searched; secondly, for REW magnitude quantization, this dissertation proposed a DCT-matrix multi-codebooks quantization scheme. The classification in muti-codebooks is based on pitch and quantized SEW power. The multi-codebooks structure may offer more the information in quantization and solve the problem of the bit requirement limits in quantization by consuming some extra storage space; Furthermore, for the switch quantization of CW gain, a new classified parameter is proposed.

本文的主要贡献体现为如下几方面：一、为了减少WI模型的计算复杂度，提出了基于快速傅立叶变换、三次B样条插值和周期延拓技术的特征波形(Characteristic Waveform，CW)表示和对齐的快速算法，与原方法相比，计算量下降到原方法的1/5，同时也使得CW在插值和量化时更合理；二、为了严格保证SEW与REW的能量和为1，提出了一种特征波形的二次功率归一化算法，仅需要SEW能量就可以算出二者的能量比，并可应用到后续的REW的分类量化和CW合成中；三、为了对慢渐变波形(Slowly Evolving Waveform，SEW)幅度、快渐变波形(Rapidly Evolving Waveform，REW)幅度和特征波形功率进行有效量化，本文首先采用临界频带理论、分析合成技术、感觉加权技术以及预测式矢量量化技术，提出了一种基于基音周期分类的SEW分析合成预测式多码书量化方法；其次，本文根据基音和量化后SEW的功率信息对REW幅度进行分类，提出了一种基于离散余弦变换的REW矩阵多码书量化方法。

Based on this, aim at the disadvantage on Wigner Distribution and Fractional Fourier Transform that can't restrain noise interference effectively when be used to detect Linear Frequency Modulated signals interfered by heavy noises, we proposed a improved WD. Simulation results show that this method can restrain noise interference effectively and improve the ability of LFM signals detection. On the other hand, in multi-component cases, WD suffers from the cross-terms, which may impair some of the auto-terms. In order to separate original multi-component signals into components and reconstruct them separately, we can use the method of optimal filtering in fractional Fourier domain. But this method also has a problem that if signals have aliasing in the fractional Fourier optimal domain as well, the reconstructed signals will be distorted. In this thesis, a novel method of quasi Fourier transform is proposed in order to solve the problem of multi-component signal reconstruction, and have good results.

在此基础上，针对Wigner分布和分数维傅里叶变换在处理高噪声背景下线性调频信号检测的问题时存在不能有效抑制噪声干扰的缺点，提出了改进Wigner分布的办法，该方法能够抑制噪声，提高信号的检测能力；针对Wigner分布在处理多分量非线性调频信号时存在干扰项的缺点，以及分数域最优滤波方法在处理多分量非线性调频信号分离重构问题时存在的局限性，该局限性表现为在对最优分数域上也有信号分量重叠的情况进行处理时重构信号发生畸变，提出了新颖的类傅里叶变换的方法，该方法对在最优分数域上也有信号分量重叠的情况也能处理，得到的重构信号失真很小。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。