拓扑变换

It solves the problem that the unitary contour presentation can not correctly extract face contour in a face image which suffers from scale, rotation etc. The definition of the internal and external energy function is provided. At the same time, the global matching algorithm and local matching algorithm is given. The experiment shows that this presentation and the accompanying matching algorithm can be used to extract the face contour very well. So the image segmentation can be implemented by using it.②By analyzing the recognition principle of PCA method, we can conclude that the face images coming from different surrounding consist of different face image space. This is the essential reason that makes the generality of PCA method worse. Also, we give a measurement means to measure the distance from different face image space, so we can analyze face image space more conveniently.③We also construct various scale models and rotation pose models to detect the scale and rotating angle of face image to be recognized. The experiment results show that the detecting precision is very high. So it is good for face image feature extraction and face image representation.④Similarly, we construct local feature models of face image and utilize them to detect the local feature of face image. At the same time, we put forward a novel face image local feature detection algorithm, locating step by step. The experiment results show that this method can accurately detect the location of local face feature in a image.⑤A novel face image presentation model, dual attribute graph , is put forward. Firstly, it utilizes attribute graph to present the face image, then exact the local principal component coefficient and Gabor transform coefficient of thc pixels which corresponds to the nodes of the graph as the attribute of the nodes. This representation fully makes use of the statistical characteristic of the local face feature and utilizes Gabor transform to present the topographical structure of face image. So DAG has more general property.⑥Based on the DAG presentation, we give a DAG matching function and matching algorithm. During the design of the function and algorithm, the noise factor, e. g., lighting, scale and rotation pose are considered and tried to be eliminated. So the algorithm can give more general property.⑦A general face image recognition system is implemented. The experiment show the system can get better recognition performance under the noise surrounding of lighting, scale and rotation pose.

本文在上述研究的基础上，取得了如下主要研究成果：①构造了一个通用的人脸轮廓模型表示，解决了由于人脸图象尺度、旋转等因素而使得仅用单一轮廓表示无法正确提取人脸轮廓的问题，并给出了模型内、外能函数的定义，同时给出了模型的全局与局部匹配算法，实验表明，使用这种表示形式以及匹配算法，能够较好地提取人脸图象的轮廓，可实际用于人脸图象的分割；②深入分析了PCA方法的识别机制，得出不同成象条件下的人脸图象构成不同的人脸图象空间的结论，同时指出这也是造成PCA方法通用性较差的本质原因，并给出了不同人脸空间距离的一种度量方法，使用该度量方法能够直观地对人脸图象空间进行分析；③构造了各种尺度模板、旋转姿势模板以用于探测待识人脸图象的尺度、旋转角度，实验结果表明，探测精确度很高，从而有利于人脸图象特征提取，以及图象的有效表示；④构造了人脸图象的各局部特征模板，用于人脸图象局部特征的探测；同时提出了一种新的人脸图象局部特征探测法---逐步求精定位法，实验结果表明，使用这种方法能够精确地得到人脸图象各局部特征的位置；⑤提出了一种新的人脸图象表示法---双属性图表示法；利用属性图来表示人脸图象，并提取图节点对应图象位置的局部主成分特征系数以及Gabor变换系数作为图节点的属性，这种表示方法充分利用了人脸图象的局部特征的统计特性，并且使用Gabor变换来反映人脸图象的拓扑结构，从而使得双属性图表示法具有较强的通用性；⑥在双属性图表示的基础上，给出双属性图匹配函数及匹配算法，在函数及算法设计过程中，考虑并解决了光照、尺度、旋转姿势变化等因素对人脸图象识别的影响，使得匹配算法具有较强的通用性；⑦设计并实现了一个通用的人脸图象识别系统，实验结果表明，该系统在图象光照、尺度、旋转姿势情况下，得到了较好的识别效果。

Owing to its small volume, light weight, high efficiency, succinct circuitry, high reliability and great capability of self-equalizing output loads in different circuitries, the Fly-back Converter becomes the optimally topological form of designing auxiliary power supply of high frequency switching power and driving power supply of power switching.

由于反激式变换器不但具有体积小、重量轻、效率高、线路简洁、可靠性高等优点，而且还具有较强的自动均衡各路输出负载的能力，目前反激式变换器的电路拓扑形式已成为人们设计高频开关电源的辅助电源以及设计各种功率开关驱动电源的首选。

By using in a sequence the eigen-decomposition,a permutation,the inverse discrete Fourier transformand a truncation on the matrix,an exact and explicit parametrization formula for Loop subdivision surfaces is proposed.

利用控制网格拓扑结构的对称性，通过将奇异点周围1-环和2-环的控制顶点进行离散Fourier变换得到分块对角阵，将其进行特征分解及排序之后，再通过离散Fourier逆变换和截断等操作得到细分矩阵的高次幂的表达式，从而得到Loop 细分曲面新的精确参数化公式

Relative study indicate that current doubler rectifier is misfit for high-voltage low-current apply.so This paper proposes a auxiliary net ZVS PWM full-bridge three-level converter, its" improved topology structure and its"topology family in different controlling mode. The principle of these converter is analyzed in detail. Simulation results verify the effectiveness of the proposed converter.

为了进一步简化辅助网络的结构，并解决轻载时，超前桥臂实现软开关困难的问题，提出了一种新型宽负载范围辅助电感ZVS PWM三电平全桥直流变换器，它在基本拓扑结构的基础上只需增加一个辅助电感，利用辅助电感的能量就可以实现宽负载范围内所有开关管的软开关，详细分析了该变换器的工作原理，进行了参数设计和仿真验证。

Through analysis and simulation, this paper did some research about the open-circuit fault diagnosis of transistors in three-level inverter.

该文针对三电平变换器的拓扑，通过理论分析和仿真实验，对变换器中的各功率管开路故障诊断进行研究。

Through analysis and simulation, the short- circuit and open-circuit fault diagnosis of transistors in the widely used asymmetric bridge converter were studied.

针对不对称半桥式功率变换器的主电路拓扑，通过理论分析和仿真实验，对变换器中的功率管短路和开路故障诊断进行研究。

Cascade and diode-clamp voltage source converter has become increasingly popular in recent years due to their practicability.

级联多电平变换器和二极管箝位多电平变换器是现今研究较多并且实用性较强的两种多电平拓扑结构。

A composite cascade multilevel converter composed of a main converter and an accessorial one is presented which is well suited for application in high voltage situations with high performance requirements.

针对高电压、高性能功率变换场合的需要，提出了一种主从组合式多电平变换器的拓扑组合结构，具有输出波形质量高、输出电压等级高和功率转换效率高等特点。

MACT uses an improved cone tree as the metaphor of network topology. Real time traffic between every two directly connected nodes are represented with animated color lines, and the shade of each line's color is determined by the data rate through the line.

MACT用改进的Cone tree作为网络拓扑隐喻，用不同颜色的动态模式变换线，表示任意两个相连节点之间的实时数据流（颜色表示数据流速，模式变换的方向表示数据流向），用始于一个节点的两种颜色的圆柱，表示流入和流出该节点的数据总量。

The topology structure is modified on the basis of basic principle of phase shift fullbridge ZVZCS PWM converter.

在移相全桥ZVZCS PWM变换器基本原理的基础上，对其拓扑结构进行了改进，实现了一种带双变压器结构的零电压零电流移相全桥PWM控制变换器。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。