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15
Automatic Surface Reconstruction From Point Sets in Space
 Computer Graphics Forum
, 2000
"... In this paper an algorithm is proposed that takes as input a generic set of unorganized points, sampled on a real object, and returns a closed interpolating surface. Specifically, this method generates a closed 2manifold surface made of triangular faces, without limitations on the shape or genus of ..."
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Cited by 41 (6 self)
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In this paper an algorithm is proposed that takes as input a generic set of unorganized points, sampled on a real object, and returns a closed interpolating surface. Specifically, this method generates a closed 2manifold surface made of triangular faces, without limitations on the shape or genus of the original solid. The reconstruction method is based on generation of the Delaunay tetrahedralization of the point set, followed by a sculpturing process constrained to particular criteria. The main applications of this tool are in medical analysis and in reverse engineering areas. It is possible, for example, to reconstruct anatomical parts starting from surveys based on TACs or magnetic resonance.
Sliverfree Three Dimensional Delaunay Mesh Generation
 PH.D THESIS, UIUC
, 2000
"... A key step in the nite element method is to generate wellshaped meshes in 3D. A mesh is wellshaped if every tetrahedron element has a small aspect ratio. It is an old outstanding problem to generate wellshaped Delaunay meshes in three or more dimensions. Existing algorithms do not completely solv ..."
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Cited by 13 (5 self)
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A key step in the nite element method is to generate wellshaped meshes in 3D. A mesh is wellshaped if every tetrahedron element has a small aspect ratio. It is an old outstanding problem to generate wellshaped Delaunay meshes in three or more dimensions. Existing algorithms do not completely solve this problem, primarily because they can not eliminate all slivers. A sliver is a tetrahedron whose vertices are almost coplanar and whose circumradius is not much larger than its shortest edge length. We present two new algorithms to generate sliverfree Delaunay meshes. The rst algorithm locally moves the vertices of an almostgood mesh, whose tetrahedra have small circumradius to shortest edge length ratio. We show that the Delaunay triangulation of the perturbed mesh vertices is still almost good. Furthermore, most slivers disappear after a mild perturbation of the mesh vertices. The remaining slivers migrate to the boundary where they can be peeled o or can be treated with boundary enforcement heuristics. The second algorithm adds points to generate wellshaped meshes. It is based on the following observations. Any tetrahedron will disappear from the Delaunay triangulation if a point is added inside the circumsphere of the tetrahedron. Among the tetrahedra created by
Efficient node overlap removal using a proximity stress model
 In 16th Symp. on Graph Drawing (GD
, 2008
"... Abstract. When drawing graphs whose nodes contain text or graphics, the nontrivial node sizes must be taken into account, either as part of the initial layout or as a postprocessing step. The core problem is to avoid overlaps while retaining the structural information inherent in a layout using li ..."
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Cited by 13 (6 self)
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Abstract. When drawing graphs whose nodes contain text or graphics, the nontrivial node sizes must be taken into account, either as part of the initial layout or as a postprocessing step. The core problem is to avoid overlaps while retaining the structural information inherent in a layout using little additional area. This paper presents a new node overlap removal algorithm that does well by these measures. 1
Anisotropic Mesh Generation with Particles
, 1996
"... Many important realworld problems require meshing, that is the approximation of a given geometry by a set of simpler elements such as triangles or quadrilaterals in two dimensions, and tetrahedra or hexahedra in three dimensions. Applications include finite element analysis and computer graphics. T ..."
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Cited by 10 (1 self)
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Many important realworld problems require meshing, that is the approximation of a given geometry by a set of simpler elements such as triangles or quadrilaterals in two dimensions, and tetrahedra or hexahedra in three dimensions. Applications include finite element analysis and computer graphics. This work focuses on the former. A physicallybased model of interacting "particles" is introduced to uniformly spread points over a 2dimensional polygonal domain. The set of points is triangulated to form a triangle mesh. Delaunay triangulation is used because it guarantees a low computational cost and reasonably wellshaped elements. Several particle interaction (repulsion and attraction) models are investigated ranging from Gaussian energy potentials to Laplacian smoothing. Particle population control mechanisms are introduced to make the size of the mesh elements converge to the desired size. In most applications spatial mesh adaptivity is desirable. Triangles should not only adapt in si...
WLAN based Pose Estimation for Mobile Robots
 in Proceedings of the 17th IFAC World Congress, Seoul, Korea
, 2008
"... Abstract: Nowadays, many buildings are equipped with a WLAN infrastructure, as an inexpensive communication technology. In this paper a method to estimate position and heading (pose) of a mobile robot using WLAN technology is described. The proposed technique for localizing a mobile robot is based o ..."
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Cited by 2 (1 self)
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Abstract: Nowadays, many buildings are equipped with a WLAN infrastructure, as an inexpensive communication technology. In this paper a method to estimate position and heading (pose) of a mobile robot using WLAN technology is described. The proposed technique for localizing a mobile robot is based on the use of received signal strength values of WLAN access points in range. A radio map based method and Euclidean distance in combination with Delaunay triangulation and interpolation is proposed. Measured signal strength values of an omnidirectional antenna and a beam antenna are compared with the values of a radio map, in order to estimate the pose of a mobile robot, whereby the directionality of the beam antenna is used to estimate the heading of the robot. The paper presents the experimental results of measurements in an office building. 1.
Méthodologie de Modélisation de la Croissance de Neurosphères
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, 2009
"... When drawing graphs whose nodes contain text or graphics, the nontrivial node sizes must be taken into account, either as part of the initial layout or as a postprocessing step. The core problem in avoiding or removing overlaps is to retain the structural information inherent in a layout while mini ..."
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When drawing graphs whose nodes contain text or graphics, the nontrivial node sizes must be taken into account, either as part of the initial layout or as a postprocessing step. The core problem in avoiding or removing overlaps is to retain the structural information inherent in a layout while minimizing the additional area required. This paper presents a new node overlap removal algorithm that does well at retaining a graph’s shape while using little additional area and time. As part of the analysis, we consider and evaluate two measures of dissimilarity for two layouts of the same graph. Submitted:
International Journal of Computing, SPECAL ISSUE: Intelligent Data Acquisition and Advanced Computing Systems, 7(2):pp.7383 Mobile Robot Localization using WLAN Signal Strengths
"... Abstract—Many buildings are already equipped with a WLAN infrastructure, as an inexpensive communication technology. In this paper two methods that estimate the position and the heading (pose) of a mobile robot using WLAN technology are described. The proposed techniques for localizing a mobile robo ..."
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Abstract—Many buildings are already equipped with a WLAN infrastructure, as an inexpensive communication technology. In this paper two methods that estimate the position and the heading (pose) of a mobile robot using WLAN technology are described. The proposed techniques for localizing a mobile robot are based on the use of received signal strength values of WLAN access points in range. Both use a radio map based method. For interpolation of the radio map weigthed Euclidean distance and Euclidean distance in combination with Delaunay triangulation is proposed. Measured signal strength values of an omnidirectional antenna and a beam antenna are compared with the values of a radio map, in order to estimate the pose of a mobile robot, whereby the directionality of the beam antenna is used to estimate the heading of the robot. The paper presents the experimental results of measurements in an office building. Index Terms—Mobile robots, global localization, pose estimation, WLAN, received signal strength. I.
Date: 12/09/2007
"... This paper investigates the implement of the divideandconquer Delaunay Triangulation. The global aim is to improve its performance. Up to now it is not available an algorithm that can build the Delaunay triangulation for n points, with nonuniform distribution, with time complexity lower than O(nl ..."
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This paper investigates the implement of the divideandconquer Delaunay Triangulation. The global aim is to improve its performance. Up to now it is not available an algorithm that can build the Delaunay triangulation for n points, with nonuniform distribution, with time complexity lower than O(nlogn). With this purpose an improved algorithm by Geoff Leach was selected, this algorithm improved the GuibasStolfi algorithm by a factor of 45. We present our current process on implement and study of this problem with the expectation of solving the triangulation in lower than O(nlogn) time complexity by using a C++ program run on Window XP environment. Experimental results are presented for the problem includes run time data, compare charts, and discussing. The source code is also provided for future references. Triangulations of a planar point set are extremely important in computer graphics. Triangulation is essential in polygonbased rendering (used by APIs such as