查询词典 boundary element method

Coordinate sequence method is made up of the instruct information of polygon boundary x, y coordinate. It is the easiest polygon vector encoding method. The file structure of this method is easy, but because of the polygon boundary has stored two times, it will produce data redundancy, moreover, short of neighbor threshold information; Tree index encoding method make all the boundary points digitizing, store the coordinate sequence, connect the point index to boundary line, and then connect the line index to other polygons, so as to the tree index structure has came into being. It eliminates neighbor polygons boundary data redundancy problems; Topology structure encoding method is a method which by setting up a complete topology relationship structure, resolve the neighbor threshold and island information process problem. However, it makes arithmetic more complicated and makes database bigger.

坐标序列法是由多边形边界的x，y坐标对集合及说明信息组成，是最简单的一种多边形矢量编码法，文件结构简单，但多边形边界被存储两次产生数据冗余，而且缺少邻域信息；树状索引编码法是将所有边界点进行数字化，顺序存储坐标对，由点索引与边界线号相联系，以线索引与各多边形相联系，形成树状索引结构，消除了相邻多边形边界数据冗余问题；拓扑结构编码法是通过建立一个完整的拓扑关系结构，彻底解决邻域和岛状信息处理问题的方法，但增加了算法的复杂性和数据库的大小。

In chapter 2,all kinds of numerical methods of computational fracturemechanics are summarized,the development histories and present situation ofboundary collocation method,boundary integral method,finite difference method,boundary element method and finite element method are expounded,and theapplication of finite element method in fracture mechanics are emphaticallydiscussed.

第二章 总结了计算断裂力学中各种数值方法，论述了边界配位法、边界积分法、有限差分法、边界元法及有限元法的发展历史和现状，并着重讨论了有限元法在断裂力学中的应用。

A semiconductor device including a high voltage element and a low voltage element, including: a semiconductor substrate having high voltage element region where the high voltage element is formed, and a low voltage element region where the low voltage element is formed; a first LOCOS isolation structure disposed in the high voltage element region; and a second LOCOS isolation structure disposed in the low voltage element region, wherein the first LOCOS isolation structure includes a LOCOS oxide film formed on a surface of the semiconductor substrate and a CVD oxide film formed on the LOCOS oxide film, and the second LOCOS isolation structure includes a LOCOS oxide film.

提供一种在确保高耐压元件的高耐压特性的同时使高耐压元件和低耐压元件具有良好特性的半导体装置。具有高耐压元件和低耐压元件的半导体装置包含：规定了形成高耐压元件的高耐压元件区和形成低耐压元件的低耐压元件区的半导体衬底；在该高耐压元件区设置的第一LOCOS隔离结构；以及在该低耐压元件区设置的第二LOCOS隔离结构。第一LOCOS隔离结构由在该半导体衬底的表面上形成的LOCOS氧化膜和其上形成的CVD氧化膜构成，第二LOCOS隔离结构由LOCOS氧化膜构成。

It is the first important step in video analysis and will directly affects the effectiveness of indexing Shot boundary detection is one of our major research interests and we will tackle the following existing problems the ambiguity between gradual change and camera motion, the discontinuity during gradual change, false detection caused by illumination variation and flashlight, automatic threshold selection Firstly, we discuss shot boundary detection in non-compressed domain In chapter 2, we compare some of the commonly used detection methods which are based on frame difference and point out that single feature will not generate good results As a conclusion, we use fuzzy logic to combine multiple features Presently, most frame difference based shot boundary detection algorithms rely on threshold and hence the selection of such thresholds will greatly affect the performance of boundary detection We propose a membership function to define frame difference and calculate the membership with self adaptation according to the statistic distribution of frame differences to satisfy different type of video clips Experiments show that the proposed fuzzy shot boundary detection algorithm can be used with different video types and has a high detection precision and recall In chapter 3, we discuss model-based shot boundary detection algorithms regarding chromatic and spatial editing effects such as fade-in, fade-out, dissolve and wipe Various parameters are proposed to better describe the characteristics of each editing type.

镜头边界的检测是把视频自动地分割为一个个镜头，作为基本的索引单元，因此它是视频分析重要的第一步，直接影响到视频检索的成败。镜头边界的检测是本文研究的重点之一。目前镜头边界检测算法主要存在以下问题：渐变与镜头运动难以区别；渐变过程中的不连续与停顿、光照条件的变化及闪光灯等特殊情况会引起误检测；自动选择阈值比较困难等。本文首先针对非压缩域视频进行了镜头边界检测的研究。在第二章中我们采用了比较流行的基于帧间差的方法。在比较各种帧间差计算方法的基础上，指出使用单一的特征难以取得很好的检测效果，提出用模糊逻辑综合使用各种特征。目前大多数基于帧间差的镜头边界检测算法都采用阈值法进行镜头转换的判别。阈值选择的误差对检测性能有较大的影响，本文提出用隶属度函数定义帧间差较大、中等较大和较小等概念，并根据帧间差的统计分布自适应地确定隶属度，以适应不同类型的视频片断。实验结果表明这种基于糊逻辑的镜头边界检测算法可以适应不同的视频，并具有较高的检测精度和检出率。在第三章中采用基于模型的方法进行镜头渐变的检测，研究了淡入／淡出、慢转换和扫换的模型。

For reducing boundary distortion area, the elevations of grid DEM are viewed as a discrete sequence under a generalized coordinate, so that the boundary problem of two-dimensional discrete wavelet transform is turned into the boundary problem of one-dimensional discrete wavelet transform, which not only greatly reduces the boundary distortion area, improves the precision of reconstructed DEM data near the boundary, but also decreases the number of zeros adding on the boundary for wavelet transform, and boosts the compression ratio. On the basis of analyzing the distribution characteristics of coefficients in low and high frequency bands, a mixed entropy coding plan is applied, and a high efficient quantizator called"self-adaptive hard threshold"is established, which is helpful for improving the precision of the reconstructed DEM data and for enhancing compression ratio.

为了减小小波变换山区格网DEM数据压缩中边界失真区域，将山区格网DEM高程值视为广义坐标下的离散随机序列，把二维离散小波变换中的边界问题转换为一维离散小波变换中的边界问题，不仅大大减少了小波变换边界失真区域，提高了重构DEM数据边界点的精度，而且减少了边界补零个数，提高了压缩比；通过对山区格网DEM数据小波变换低频区和高频区变换系数分布特点的分析，采取了霍夫曼—游程混合熵编码方案，设计了高效、低失真的"自适应硬阈值"量化器，即对低频区变换系数不进行量化，直接进行霍夫曼编码；对高频区变换系数则先用"自适应硬阈值"方法量化处理，再进行游程编码。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

In the last chap-ter,the natural integral equation and natural boundary element method forharmonic problem on exterior elliptic domain are introduced.Then,based onthis,the natural boundary reduction method for a kind of exterior problem ofanisotropic constant coefficients elliptic equation is discussed, the natural inte-gral equation and its solving method on circular boundary and elliptic bound-ary are obtained.These results can be directly applied in coupled methodand DDM for exterior boundary value problem.

最后，讨论了椭圆外区域调和问题的自然积分算子即D-N算子及自然边界元方法，并基于此研究了一类各向异性常系数椭圆型方程外问题的自然边界归化方法，首次得到其在圆周边界及椭圆边界上的自然积分方程及其求解方法，并将这些结果直接应用于外边值问题的耦合算法。

An algorithm about picking element is presented in this paper: First,getting certain amounts of boundary points by contour tracing from a point near an element and calculating primal parameters; Then, picking the element completely by element tracing guided by these initial parameters, jumping over broken points and intersecting points; At last,deleting the picked element from the raster image and renewing other elements' information intersecting with the picked element.

本文提出一种图元拾取算法：首先从图元附近一点开始，经轮廓跟踪、参数拟合得到图元的初始参数；然后在初始参数引导下，对图元定向跟踪，跳过断点和交点，最大限度的拾取整个图元；最后在光栅图像上删除该图元，并恢复与之相交的其它图元的交点信息。

Then the boundary element integral equation of interior and exterior form is deduced in detail, also the form with corner coefficient. The significance for numerical calculation and principle of the singular integral is analyzed, and a non-isoparametric transformation method is presented to calculate weak singular integral and Cauchy integral, the method presented provides us a very simple way to computer the two kinds of singular integral of Helmholtz boundary integral equation, and it is easy to program in computer. After the difficulty of the calculation for multi-frequency of Helmholtz boundary element is explained, a method named SECHIEF (Series Expansion Combined Helmholtz Integral Equation Formulation), which is focused on the computational efficiency, is presented.

对结构声辐射的边界积分方程的内部形式与外部形式进行了详细的推导，给出了角点系数的计算方法与边界积分方程的形式，在此基础上，分析了奇异积分产生的原理及其对数值计算的重要性，提出了一种计算奇异积分的非等参(来源：Ae8a8BC论文网www.abclunwen.com)单元的变换方法，该方法给Helmholtz 声学边界积分方程中的弱奇异积分与Cauchy 奇异积分的计算以及编程提供了极大便利。

The article in recent years the research progress of disease of oral cavity of TP prevention and cure makes one overview. The compositive TP of the basic research 1.1 TP of 1 TP is the floorboard that phenolic apperception of a kind of many hydroxyl closes matter, 25% what hold tea dry weight about, its are main component includes to express gallnut of gallnut catechu element gallnut of element of catechu of gallnut of acerbity ester, watch, watch catechu element is acerbity element of catechu of ester, watch, express gallnut of gallnut catechu element among them acerbity ester content is highest, occupy the 80%[1] of catechu element about, fighting oxidation with its unique element structure, fight the position with fight the respect such as tumor to have choppy, significant. The 1.2 TP absorption in oral cavity and metabolization Lee [2] is measured normally inside a hour after healthy person is chewing green tea Xie Huo contains juice of gargle green tea, content of the TP in saliva is very high, after observing green tea passes salivary enzymatic hydrolyze, TP is slow release and in oral cavity;Yang of local play action [the salivary level after 3] checked 6 volunteers to drink tea, chroma of the TP in making clear the saliva after drinking tea as a result is serous TP pH indicator 2 times, and the salivary TP concentration that contains gargle tea solution a few minutes to be able to produce higher level, and TP can be absorbed through oral cavity mucous membrane.

本文就近年来TP防治口腔疾病的探究进展作一综述。1 TP的基础探究1.1 TP的组成TP是一类多羟基酚类化合物的总称，约占茶叶干重的25%，其主要成份包括表没食子儿茶素没食子酸酯、表没食子儿茶素、表儿茶素没食子酸酯、表儿茶素等，其中表没食子儿茶素没食子酸酯含量最高，约占儿茶素的80%[1]，并以其独特的分子结构在抗氧化、抗突变、抗肿瘤等方面占有重要的地位。1.2 TP在口腔中的吸收和代谢Lee等[2]测得正常健康人在咀嚼绿茶叶或含漱绿茶液后的一个小时内，唾液中TP含量很高，并观察到绿茶通过唾液酶水解后，TP缓慢释放并在口腔局部发挥功能；Yang等[3]检查了6位志愿者饮茶后的唾液水平，结果表明饮茶后唾液中TP浓度是血浆TP浓度的2倍，而含漱茶溶液几分钟即可产生更高水平的唾液TP浓度，且TP可通过口腔黏膜吸收。

I hope that this success is just the first in a long series.

我希望这只是成功的开始。

Three dimensional stresses on the interface of tire and soil, tire deflection and soil sinkage are measured.

测试轮胎——沙土界面上的三向应力、轮胎变形和沙土沉陷；建立考虑剪切应力对沙土承载特性产生影响的车轮牵引性能预测模型；分析车轮作用下土壤的纵向稳定性。