查询词典 boundary line

By analyzing the characteristics of the boundary pixels to formulate a boundary pixel extraction operator, the operator need only calculate up to 4 pixels neighborhood pixels, is efficient, fast, he can direct the use of binary images are extracted as the boundary pixel, are single-pixel wide border.

通过分析边界象素的特征，归纳出一个边界象素提取算子，该算子最多只需要计算象素的4邻域象素，运算量小，速度快，运用他能直接提取出二值图象的边界象素，得到单象素宽的边界。

Based on image statistical characteristic, the algorithm can search automatically the boundary start-point using Sobel operator and special template operation, then according to the connection status of every boundary point in its 8-connection neighbor field, seek automatically the search direction, form the whole data collection of a target boundary outline.

该算法依据目标图象特征，在二值图象中利用Sobel算子和特定的模板操作，自适应搜索边界起点；然后，按照每个边界点在其8邻域内的连通情况，自动寻找搜索方向，形成了完整目标边界轮廓数据集。

Subsequently, an intuitionistic definition of Complex boundary is given with Simplex boundary and then a capture method of it is offered too, thereby auto-capture of Complex boundary is achieved.

随后，本文利用单形边界给出了复形边界的直观性定义，提供了具体应用中复形边界的获取方法，从而可以对复形的边界进行自动获取。

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。

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。

The phase of optical wave can be recovered by the intensity transport equation under the paraxial approximation For the optical system with diffraction limit, it is difficult to get the boundary radical slope of phase and sample in the circular domain boundary when using the intensity transport equation to recover the phase, consequently, we reviewed an algorithm mentioned in the reference ［4］, namely, the equation, computation domain and boundary condition are changed, then the phase is reconstructed by the multigrid method and corrected at last Moreover, the experiment system is set to testify the algorithm, and the recovered phase from the intensity data detected by CCD is compared with the result from phase retrieval algorithm, it is found that the phase reconstruction error can reach 017 λ in the case of non-uniform intensity distribution, as a result, the method is suitable for the phase recovery with low wavefront sensing accuracy.

在傍轴近似条件下，可以利用光强传播方程对畸变波前进行相位恢复。对于衍射受限的光学系统，很难获得相位的边界径向斜率值作为边界条件，此外，要获得精确的圆域边界采样值也并非易事。为了克服上述困难，进一步研究了相位恢复改进方法，即改变了方程的表示形式、计算区域和边界条件，并用多重网格法进行求解获得重构相位，最后再将其修正。为了验证算法的精确性，搭建了实验系统对算法进行实验验证，将由CCD探测的光强分布进行计算得到的相位分布与相位恢复算法的结果进行比较，证明在光强分布非均匀的情况下，该方法恢复的相位均方根误差能够达到017 λ，可以适用于波前传感精度要求不是很高的相位恢复。标签自适应光学相位恢复相位修正光强传播方程 adaptive optics phase retrieval phase correction intensity transport equation

In this paper the natural boundary reduction for some elliptic boundary value problems with concave angle domains and its natural boundary element methods are investigated.

本文研究凹角型区域椭圆边值问题的自然边界归化及其边界元法。

Part II, the artificial boundary condition and its numerical methods based on natural boundary reduction for a hyperbolic initial boundary value problem in an infinite domain with a concave angle is investigated.

第二部分，研究一类具有凹角的无界外区域的双曲型初边值问题基于自然边界归化的人工边界条件及其数值方法。

Based on the correlation of the Guadalupian and Lopingian conodont zones of the Salt Range, Pakistan with those of South China, the Amb Formation and the lower part of the Wargal Formation in the Salt Range, Pakistan are Late Guadalupian in age. The Guadalupian/Lopingian boundary is in the lower part of the Wargal Formation, and the Wuchi-apingian/Changhsingian boundary is in the lower part of the Chhidru Formation. The Permian/Triassic boundary is in the Kathwai Member of the Mianwali Formation.

根据华南与盐岭地区瓜达鲁普统和乐平统的牙形类化石带对比，可以确定Amb组和Wargal组底部的时代为瓜达鲁普世晚期，瓜达鲁普统与乐平统的界线位于Wargal组下部，吴家坪阶与长兴阶的界线位于Chhidru组的下部，而二叠与三叠系的界线位于Mianwali组下部的Kathwai段之内。

Take the method of "subarea" and "conjunction" to segment the whole request model to three parts. Making use of boundary continuousness between medium and lining structure at stress and displacement, construct a wave function that can satisfy the stress boundary condition at horizontal surface by the scattering of SH-waves in circular part. And then, availing of the wave function, conjoin the circular part into the semi-circular hollow space at common boundary. The problem can be reduced to solve the question that can only meet the condition of "conjunction". Finally, the solution of the problem can be summarized to a series of algebraic equations and solved numerically by truncating the finite terms of the infinite algebraic equations.

采用"分区"与"契合"的方法，将整个求解区域分割成三部分，利用介质与衬砌结构在边界上的应力、位移的连续性，构造一个可以自动满足水平界面上应力边界条件的圆域对SH波散射的波函数；再利用这一波函数将圆域与半圆形凹陷半空间的"公共边界"进行"契合"，将问题简化成对一个只需满足'契合'边界条件的散射问题的求解；最终归结为对一组无穷代数方程组的求解问题，利用截断有限项的方法对其进行计算。

The Porsche Owner: But it's my car!

可，这是我的车呀。

LOX_83}{Oh, another bunch of wackos.

{LOX_83}{呃，又一群怪人。