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11.
《Journal of Graph Theory》2018,89(3):350-360
Suzuki [Discrete Math. 310 (2010), 6–11] proved that for any orientable closed surface F2 other than the sphere, there exists an optimal 1‐planar graph which can be embedded on F2 as a triangulation. However, for nonorientable closed surfaces, the existence of such graphs is unknown. In this article, we prove that no optimal 1‐planar graph triangulates a nonorientable closed surface. 相似文献
12.
Interpolating minimal energy C1‐Surfaces on Powell–Sabin Triangulations: Application to the resolution of elliptic problems 下载免费PDF全文
M. A. Fortes P. González M. J. Ibáñez M. Pasadas 《Numerical Methods for Partial Differential Equations》2015,31(3):798-821
In this article, we present a method to obtain a C1‐surface, defined on a bounded polygonal domain Ω, which interpolates a specific dataset and minimizes a certain “energy functional.” The minimization space chosen is the one associated to the Powell–Sabin finite element, whose elements are C1‐quadratic splines. We develop a general theoretical framework for that, and we consider two main applications of the theory. For both of them, we give convergence results, and we present some numerical and graphical examples. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 798–821, 2015 相似文献
13.
This paper presents the derivation of the precise relation between the displacement of a light spot on an object's surface and the displacement of its image on the detector in an optical triangulation device, along with applications of the design of triangulation devices. Based on this relation, improved designs of optical triangulation devices, including devices of adjustable configurations, are proposed and discussed. 相似文献
14.
15.
A new simplicial variable dimension restart algorithm is introduced to solve the nonlinear complementarity problem on the
product spaceS of unit simplices. The triangulation which underlies the algorithm differs from the triangulations ofS used thus far. Moreover, the number of rays along which the algorithm can leave the arbitrarily chosen starting point is
much larger. More precisely, there is a ray leading from the starting point to each vertex ofS. In caseS is the product ofn one-dimensional unit simplices the alogrithm is similar to the octahedral algorithm onR
n
having 2
n
rays. Also, the accuracy of an approximate solution in the terminal simplex of the algorithm is in general better than for
the other algorithms onS. Computational results will show that the number of iterations for the new algorithm is much less. The examples concern the
computation of equilibria in noncooperative games, exchange economies and trade models.
This author is financially supported by the Netherlands Organisation for the Advancement of Pure Research (ZWO), Grant 46-98.
This research is part of the VF-program “Equilibrium and Disequilibrium in Demand and Supply” which has been approved by the
Netherlands ministry of education and sciences. 相似文献
16.
Feng Luo Saul Schleimer Stephan Tillmann 《Proceedings of the American Mathematical Society》2008,136(7):2625-2630
It is shown that every non-compact hyperbolic manifold of finite volume has a finite cover admitting a geodesic ideal triangulation. Also, every hyperbolic manifold of finite volume with non-empty, totally geodesic boundary has a finite regular cover which has a geodesic partially truncated triangulation. The proofs use an extension of a result due to Long and Niblo concerning the separability of peripheral subgroups.
17.
激光三角法是表面形貌非接触测量中的一种常用方法,在几何测量领域应用广泛。传统的激光三角法采用高斯光束作为指示光源,在机械扫描机构的配合下,通过对被测表面逐点扫描完成表面形貌的测量。采用新型的无衍射光替代传统激光光源,解决了普通高斯光束存在的“焦深”问题,简化了机械结构。并采用基于灰色系统理论的灰色滤波进行表面形貌的分离与评定,克服了原有方法对测量数据样本量和统计特性的依赖,并通过实验表明该系统能够准确地完成表面形貌的三维测量,所提出的灰色评定方法能够比较有效地进行表面形貌的分离与评定。 相似文献
18.
本文首先利用由两组具有局部最小支集的样条所组成的基函数,构造非均匀2 型三角剖分上二元三次样条空间S31,2(Δmn(2))的若干样条拟插值算子. 这些变差缩减算子由样条函数Bij1支集上5 个网格点或中心和样条函数Bij2支集上5 个网格点处函数值定义. 这些样条拟插值算子具有较好的逼近性,甚至算子Vmn(f) 能保持近最优的三次多项式性. 然后利用连续模,分析样条拟插值算子Vmn(f)一致逼近于充分光滑的实函数. 最后推导误差估计. 相似文献
19.
1 引言 众所周知,三角剖分是在许多科学计算如曲面设计与拟合、有限元计算以及其他大型科学计算等领域中不可回避的问题. 相似文献
20.
Anne Berry 《Discrete Mathematics》2006,306(3):318-336
For a chordal graph G=(V,E), we study the problem of whether a new vertex u∉V and a given set of edges between u and vertices in V can be added to G so that the resulting graph remains chordal. We show how to resolve this efficiently, and at the same time, if the answer is no, specify a maximal subset of the proposed edges that can be added along with u, or conversely, a minimal set of extra edges that can be added in addition to the given set, so that the resulting graph is chordal. In order to do this, we give a new characterization of chordal graphs and, for each potential new edge uv, a characterization of the set of edges incident to u that also must be added to G along with uv. We propose a data structure that can compute and add each such set in O(n) time. Based on these results, we present an algorithm that computes both a minimal triangulation and a maximal chordal subgraph of an arbitrary input graph in O(nm) time, using a totally new vertex incremental approach. In contrast to previous algorithms, our process is on-line in that each new vertex is added without reconsidering any choice made at previous steps, and without requiring any knowledge of the vertices that might be added subsequently. 相似文献