变换

The transforms introduced in this dissertation make it possible use eigenvalue method to investigate the generation of internal tides over finite topographies.

坐标变换将倾斜地形变换到了平底，同时也改变了强迫源强度的分布特征，使得变换之后强迫源强度的分布与原始分布有很大的不同。

We also propose program optimization technologies: removing integer DIV and MOD, upraising common code for reducing the complex array subscription effectively.

为此本文进一步研究了数据变换和重构手段，提出通过直接扩展数组范围、构造松弛数组范围和循环扭曲变换等技术，使数据变换后的数据规模尽量小；同时，通过采用整数模和整数除消除优化技术、代码上提优化等程序优化技术，简化了数组下标表示，有效地减少了数组下标计算开销。

A method for reasonably integrating the characters of Bayer pattern with the process of wavelet transform is presented.

结合差值模型与小波变换理论，提出高频相似模型，并在理论分析的基础上，给出产生该模型时小波变换应满足的条件；从Bayer模式的内在特征出发，找到其与小波变换过程巧妙结合的方法，进而提出了R，B平面的一种有效重构方法。

Low-frequency instability in a single stage PFC converter is studied, which employs a cascade configuration of a boost converter and a forward converter.

研究了由Boost 变换器和Forward变换器级联构成的单级功率因数校正(power factor correction，PFC)变换器中的低频不稳定现象。

Cascade multilevel converter is made up of modules. It can be normally divided into two kinds: one with same modules and the other with different modules. This paper analyzes the relationship among the maximum number of output voltage level, the number of cascaded modules, and the input voltage ratio and THD of output voltage in different kinds of cascade multilevel converter. Then, some guidelines for making up cascade multilevel converter are given.

级联型多电平变换器类似于积木化的结构，本文按模块单元的结构形式，将级联型多电平变换器分为相同单元和不同单元两类，以输出最大电平数为目标，系统地分析模块单元个数与最大输出电平数、输入直流电压与最大输出电平数、以及输出电平数与谐波畸变率之间的关系，从中归纳得到构造级联型多电平变换器的指导原则。

This paper will present a new diode-clamp cascade multilevel converter derived from these two topologies. The novel concept of the new diode-clamp cascade converter is based on the connection of multiple three-level diode-clamp converter modules.The multilevel waveform is synthesized by adding of each converter output voltage.

本文将结合这两种拓扑结构，研究了一种新型的二极管箝位级联多电平变换器，其思想是将数个二极管箝位变换器模型串联起来，其输出电压是通过合成每个二极管箝位变换器的输出电压而形成的。

This thesis discussed the construction method for hybrid cascade asymmetrical multilevel converters,and some novel topologies are presented. Hybrid cascade asymmetrical multilevel converter can be derived by combining AMC and AMC,or combining AMC and SMC.

本文研究了组合式不对称混合级联型多电平变换器拓扑的生成方法，在此基础上提出了几种新型拓扑，重点研究了不对称同构混合级联型多电平变换器和不对称异构混合级联型多电平变换器。

Combined with the nonlinear characteristics of wind turbines and the control strategy of generator-side converter and grid-side converter, used the design method for digital PI regulator, the back-to-back PWM converter on the wind-power system with direct-driven permanent magnet synchronous generator was built in the simulink of the MATLAB.

结合风力机的非线性特性和机侧变换器与网侧变换器的控制策略，应用数字PI调节器参数设计方法，在MATLAB/simulink仿真环境下构建了基于背靠背变换器的永磁直驱风力发电系统，系统包括风力机、永磁同步发电机、变频器、电网及其电气控制部分的数学模型，仿真结果表明风电系统的PI调节器参数设计合理且系统具有良好的运行特性。

In order to obtain the correct height reconstruction of a measured object through the traditional Fourier transform profilometry, the connecting-line between the exit pupil of the projecting lens and the entrance pupil of the imaging lens must be horizontal and set to parallel to the reference plane.

在拍摄过程中，采集完参考平面的光场后，只需要再采集一帧条纹图形，通过傅里叶变换、频谱滤波、逆傅里叶变换、相位展开等处理后就能得到物体的三维数据。采用传统的傅里叶变换轮廓术进行三维物体面型测量时，必需保证投影装置出射光瞳和成像装置入射光瞳的连线与参考面平行，并且它们的光轴应在同一平面上，才能得到较为准确的测量结果。

Firstly, we study the theory and application of jump points and sharp cusp points detection by wavelet transform. The studied object is from white noise to correlated noise. We have studied the properties of correlated noise in wavelet transform, and the properties of deterministic function with jumps and sharp cusps in wavelet transform.

首先研究了研究了小波变换在突变点与尖点检测中的理论与应用，研究的对象由白噪到相关噪声，研究了相关噪声在小波变换的性质，以及对具有突变点和尖点的函数在小波变换下的性质，有关这些性质，我们均以定理形式给出，并给出了详细的证明。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。