Examinando por Materia "Repair"

Mostrando 1 - 4 de 4
  • Miniatura
    Ítem
    Between outside and inside. The academic field configuration and its borders from the communicative practices of black women scientists in Colombia
    (Universidad EAFIT, 2013-07-18) Pérez Bustos, Tania; Botero Marulanda, Daniela; Pontificia Universidad Javeriana
  • No hay miniatura disponible
    Ítem
    Geometrical degeneracy removal by virtual disturbances - An application to surface reconstruction from point slice samples
    (INSTICC-INST SYST TECHNOLOGIES INFORMATION CONTROL & COMMUNICATION, 2008-01-01) Ruiz, Oscar; Vasquez, Eliana; Pena, Sebastian; Granados, Miguel; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    In surface reconstruction from slice samples (typical in medical imaging, coordinate measurement machines, stereolithography, etc.) the available methods attack the geometrical and topological properties of the surface. Topological methods classify the transitions occurred in the 2-manifold between two consecutive slices i and i+ 1. Geometrical methods synthesize the surface based on local proximity of the contours in consecutive slices. Superimposed 2D Voronoi Diagrams VDi and VDi+1 for slices i and i + 1, respectively, present topological problems if, for example, a site of VD i lies on an site or an edge of VDi+1. The usual treatment of this problem in literature is to apply a geometrical disturbance to either VDi or VDi+1, thus eliminating the degeneracy. In contrast, this article presents the implementation of a method which identifies the degenerate situation, constructs un-instantiated topological constructs, choses a geometrical instantiation based on a virtual disturbance introduced to the actual configuration. The algorithm was successfully applied to remove non-manifold topologies produced by well known algorithms in surface reconstruction.
  • No hay miniatura disponible
    Ítem
    Indentation damage and crack repair in human enamel.
    (ELSEVIER SCIENCE BV, 2013-05-01) Rivera C; Arola D; Ossa A; Rivera C; Arola D; Ossa A; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
    Tooth enamel is the hardest and most highly mineralized tissue in the human body. While there have been a number of studies aimed at understanding the hardness and crack growth resistance behavior of this tissue, no study has evaluated if cracks in this tissue undergo repair. In this investigation the crack repair characteristics of young human enamel were evaluated as a function of patient gender and as a function of the distance from the Dentin Enamel Junction (DEJ). Cracks were introduced via microindentation along the prism direction and evaluated as a function of time after the indentation. Microscopic observations indicated that the repair of cracks began immediately after crack initiation and reaches saturation after approximately 48 h. During this process he crack length decreased up to 10% of the initial length, and the largest degree of reduction occurred in the deep enamel, nearest the DEJ. In addition, it was found that the degree of repair was significantly greater in the enamel of female patients.
  • No hay miniatura disponible
    Ítem
    Marching cubes in an unsigned distance field for surface reconstruction from unorganized point sets
    (INSTICC-INST SYST TECHNOLOGIES INFORMATION CONTROL & COMMUNICATION, 2010-01-01) Congote, J.; Moreno, A.; Barandiaran, I.; Barandiaran, J.; Posada, J.; Ruiz, O.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
    Surface reconstruction from unorganized point set is a common problem in computer graphics. Generation of the signed distance field from the point set is a common methodology for the surface reconstruction. The reconstruction of implicit surfaces is made with the algorithm of marching cubes, but the distance field of a point set can not be processed with marching cubes because the unsigned nature of the distance. We propose an extension to the marching cubes algorithm allowing the reconstruction of 0-level iso-surfaces in an unsigned distance field. We calculate more information inside each cell of the marching cubes lattice and then we extract the intersection points of the surface within the cell then we identify the marching cubes case for the triangulation. Our algorithm generates good surfaces but the presence of ambiguities in the case selection generates some topological mistakes.