Papers by Nancy Hitschfeld
Generación de particiones que satisfacen la condición de Delaunay para poliedros elementales 1-irregular
Vi Encuentros De Geometria Computacional Barcelona 5 6 7 De Julio De 1995 Departament De Matematica Aplicada Ii Universitat Politecnica De Catalunya Actas 1995 Isbn 84 605 3103 1 Pags 214 221, 1995
Bayesian Image Reconstruction Based on Voronoi Diagrams
The Astrophysical Journal, 2008
... Page 4. Acknowledgments I would like to thank all my family, including my mother, Ana Marıa, ... more ... Page 4. Acknowledgments I would like to thank all my family, including my mother, Ana Marıa, her husband, Alejo, my father, Guillermo, my sisters, Anita, Sole, and Vale, and my brother Javier for all the support they have given me through all my life. ...
Camarón: An Open-source Visualization Tool for the Quality Inspection of Polygonal and Polyhedral Meshes
Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 2016
There is a stage in the GPU computing pipeline where a grid of thread-blocks is mapped to the pro... more There is a stage in the GPU computing pipeline where a grid of thread-blocks is mapped to the problem domain. Normally, this grid is a k-dimensional bounding box that covers a k-dimensional problem no matter its shape. Threads that fall inside the problem domain perform computations, otherwise they are discarded at runtime. For problems with non-square geometry, this is not always the best idea because part of the space of computation is executed without any practical use. Two- dimensional triangular domain problems, alias td-problems, are a particular case of interest. Problems such as the Euclidean distance map, LU decomposition, collision detection and simula- tions over triangular tiled domains are all td-problems and they appear frequently in many areas of science. In this work, we propose an improved GPU mapping function g(lambda), that maps any lambda block to a unique location (i, j) in the triangular domain. The mapping is based on the properties of the lower triangular matrix and it works at a block level, thus not compromising thread organization within a block. The theoretical improvement from using g(lambda) is upper bounded as I < 2 and the number of wasted blocks is reduced from O(n^2) to O(n). We compare our strategy with other proposed methods; the upper-triangular mapping (UTM), the rectangular box (RB) and the recursive partition (REC). Our experimental results on Nvidias Kepler GPU architecture show that g(lambda) is between 12% and 15% faster than the bounding box (BB) strategy. When compared to the other strategies, our mapping runs significantly faster than UTM and it is as fast as RB in practical use, with the advantage that thread organization is not compromised, as in RB. This work also contributes at presenting, for the first time, a fair comparison of all existing strategies running the same experiments under the same hardware.
1-Irregular Element Tessellation In Mixed Element Meshes For The Control Volume Discretization Method
CiteSeerX - Document Details (Isaac Councill, Lee Giles): . This paper presents an algorithm to c... more CiteSeerX - Document Details (Isaac Councill, Lee Giles): . This paper presents an algorithm to compute the minimal tessellation of 1-irregular elements such as cuboids, rectangular prisms and pyramids. The minimal tessellation is the one that contains the minimum number of terminal ...
Algorithms and Data Structures for Handling a Fully
Automatic construction of quality nonobtuse boundary Delaunay triangulations
. In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay trian... more . In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay triangulations of polygons such asneeded for control volume or finite element method applications. Theseare Delaunay triangulations whose smallest angles are bounded and, inaddition, whose boundary triangles do not have obtuse angles oppositeto any boundary or interface edge. The method we propose in this paperconsists on: (1) The
Automatic construction of quality nonobtuse boundary and/or interface Delaunay triangulations the co
. In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay trian... more . In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay triangulations of polygons such asneeded for control volume or finite element method applications. Theseare Delaunay triangulations whose smallest angles are bounded and, inaddition, whose boundary triangles do not have obtuse angles oppositeto any boundary or interface edge. The method we propose in this paperconsists on: (1) The
Automatic (Triangular) Mesh Generation Based On Longest-Edge Algorithms
ABSTRACT
Approximate Quality Mesh Generation Based on Small Edge Details
International Meshing Roundtable, 2000
We present two techniques for simplifying the list processing required by methods for quality mes... more We present two techniques for simplifying the list processing required by methods for quality mesh generation basedon iterative bad triangle improvement over Delaunay meshes which use the standard basic components of insertionpoint selection and Delaunay insertion. The simplication involves compromising the shape quality requirement thatthe mesh triangles have angles all exceeding a global minimum angle tolerance. We refer to such
Terminal-Edge Refinement Algorithms: A Study on a 3DIMENSIONAL Implementation
In this paper we discuss a 3-dimensional mesh refinement tool which uses a terminal-edge refineme... more In this paper we discuss a 3-dimensional mesh refinement tool which uses a terminal-edge refinement algorithm. This is an improved algorithm that constructs the same meshes than previous longest-edge refinement algorithms by performing very local refinement operations (4,5). To this end both the terminal-edge and Lepp concepts are used. A terminal-edge l is a special edge in the mesh such
Automatic construction of quality nonobtuse boundary and/or interface Delaunay triangulations the control volume methods
. In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay trian... more . In this paper we discuss the automatic construction ofquality nonobtuse boundary Delaunay triangulations of polygons such asneeded for control volume or finite element method applications. Theseare Delaunay triangulations whose smallest angles are bounded and, inaddition, whose boundary triangles do not have obtuse angles oppositeto any boundary or interface edge. The method we propose in this paperconsists on: (1) The
Irregular Element Tessellation in Mixed Element Meshes for the Control Volume Discretization Method
. This paper presents an algorithm to compute the minimal tessellation of 1-irregular elements su... more . This paper presents an algorithm to compute the minimal tessellation of 1-irregular elements suchas cuboids, rectangular prisms and pyramids. The minimal tessellation is the one that contains the minimumnumber of terminal elements. Terminal elements are the elements that compose the final mesh. The completemesh fulfills the Delaunay condition and is adequate for the control volume discretization method (Box-method).An 1-irregular
Algorithms and Data Structures for Handling a Fully Flexible Refinement Approach in Mesh Generation
This paper presents new algorithms and data structures requ ired for the generation of grids base... more This paper presents new algorithms and data structures requ ired for the generation of grids based on mixed element trees and using flexible refinement approach. Mixed elements trees is an extension of modified octrees that uses several well-shaped prim- itives such as cuboids, prisms, pyramids and tetrahedra as i nternal nodes. A flexible refinement approach fits the object geometry and
LEPP - Delaunay Algorithm: a Robust Tool for Producing Size-Optimal Quality Triangulations
International Meshing Roundtable, 1999
. The LEPP-Delaunay algorithm forthe quality triangulation problem can be formulated interms of t... more . The LEPP-Delaunay algorithm forthe quality triangulation problem can be formulated interms of the Delaunay insertion of midpoints of terminaledges (the common longest-edge of a pair of Delaunaytriangles) and boundary edges in the currentmesh. In this paper we discuss theoretical results essentiallybased on the study of the triangle improvementproperties of the basic point insertion operations,which precisely explain the observed practical
Geneating Solid Models for VLSI Process and Device Simulation
NUPAD IV. Workshop on Numerical Modeling of Processes and Devices for Integrated Circuits,, 1992
increasing complexity of VLSI devices and processes makes the preparation of the describing the r... more increasing complexity of VLSI devices and processes makes the preparation of the describing the region geometry and the doping time-consuming and error-prone. paper describes a 3-d solid modeller, echidna, its application to the creation of models for VLSI devices and sensors, and the interface to the grid generator omegu[l]. :,re also shown of the use of echidna by a “pseudo-3-d”
Ω- An Octree-based Mixed Element Grid Allocator For Adaptive 3d Device Simulation
Workshop on Numerical Modeling of Processes and Devices for Integrated Circuits, 1990
R is an a utomatic mesh generator developed as a front-end for th4e simulation of complex threedi... more R is an a utomatic mesh generator developed as a front-end for th4e simulation of complex threedimensional (3d) semiconductor devices. Grids generated by R exhibit smooth iransilions from dense to coarse grid regions and a proper description of irregular geometries such as nonuniform surfaces and interfaces. Moreover, the underlying algorithm avoids the well-known obtuse angle problem. In addition to the
Simulation of Semiconductor Devices and Processes, 1993
We present a new algorithm for the generation of 3-dimensional (3-D) grids for the simulation of ... more We present a new algorithm for the generation of 3-dimensional (3-D) grids for the simulation of semiconductor devices. The fitting of the device geometry and the required mesh density is obtained by partitioning the elements at an optimal point at each refinement step. This allows the fitting of more general 3-D device geometries and the reduction of grid points in comparison with previous grid generators.
Generalization of Modified Octrees for Geometric Modeling
Geometric Modeling: Theory and Practice, 1997
Performance Evaluation of Portable Graphics Software and Hardware for Scientific Visualization
Visualization in Scientific Computing, 1994
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Papers by Nancy Hitschfeld