Now showing items 21-40 of 53

    • Flow computations on imprecise terrains 

      Driemel, Anne; Haverkort, Herman; Löffler, Maarten; Silveira, Rodrigo Ignacio (2013)
      Article
      Open Access
      We study water flow computation on imprecise terrains. We consider two approaches to modeling flow on a terrain: one where water flows across the surface of a polyhedral terrain in the direction of steepest descent, and ...
    • Flow computations on imprecise terrains 

      Driemel, Anne; Haverkort, Herman; Löffler, Maarten; Silveira, Rodrigo Ignacio (Springer Verlag, 2011)
      Conference report
      Restricted access - confidentiality agreement
      We study water flow computation on imprecise terrains. We consider two approaches to modeling flow on a terrain: one where water flows across the surface of a polyhedral terrain in the direction of steepest descent, and ...
    • Geomasking through perturbation, or counting points in circles 

      Löffler, Maarten; Luo, Jun; Silveira, Rodrigo Ignacio (2017)
      Conference report
      Restricted access - publisher's policy
      Motivated by a technique in privacy protection, in which n points are randomly perturbed by at most a distance r, we study the following problem: Given n points and m circles in the plane, what is the maximum r such that ...
    • Geometric biplane graphs I: maximal graphs 

      Hurtado Díaz, Fernando Alfredo; Garcia Olaverri, Alfredo Martin; Korman Cozzetti, Matías; Matos, Inés P.; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Tóth, Csaba D. (2013)
      Conference report
      Open Access
    • Geometric biplane graphs I: maximal graphs 

      Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Korman Cozzetti, Matías; Matos, Inés P.; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Tóth, Csaba D. (2015-03-01)
      Article
      Open Access
      We study biplane graphs drawn on a finite planar point set in general position. This is the family of geometric graphs whose vertex set is and can be decomposed into two plane graphs. We show that two maximal biplane ...
    • Geometric biplane graphs II: graph augmentation 

      Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Korman Cozzetti, Matías; Matos, Inés P.; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Tóth, Csaba D. (2015-03-01)
      Article
      Open Access
      We study biplane graphs drawn on a finite point set in the plane in general position. This is the family of geometric graphs whose vertex set is and which can be decomposed into two plane graphs. We show that every ...
    • Geometric Biplane Graphs II: Graph Augmentation 

      Hurtado Díaz, Fernando Alfredo; Garcia Olaverri, Alfredo Martin; Korman Cozzetti, Matías; Matos, Inés P.; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Tóth, Csaba D. (2013)
      Conference report
      Open Access
      We study biplane graphs drawn on a nite point set S in the plane in general position. This is the family of geometric graphs whose vertex set is S and which can be decomposed into two plane graphs. We show that every ...
    • III Jornada Docent del Departament de Matemàtiques 

      Pascual Gainza, Pere; Silveira, Rodrigo Ignacio; Trias Pairó, Juan; Rallo Capdevila, Miguel; Susín Sánchez, Antonio (2018-06-25)
      Audiovisual
      Open Access
      Presentació El Departament de Matemàtiques de la UPC organitza anualment una jornada docent en l’àmbit de les matemàtiques. Aquest any és la terecra edició Destinataris Professorat de la UPC i d’altres universitats, ...
    • Implementing data-dependent triangulations with higher order delaunay triangulations 

      Rodríguez, Natalia; Silveira, Rodrigo Ignacio (Multidisciplinary Digital Publishing Institute (MDPI), 2017-12-01)
      Article
      Restricted access - publisher's policy
      The Delaunay triangulation is the standard choice for building triangulated irregular networks (TINs) to represent terrain surfaces. However, the Delaunay triangulation is based only on the 2D coordinates of the data points, ...
    • Implementing data-dependent triangulations with higher order Delaunay triangulations 

      Rodríguez, Natalia; Silveira, Rodrigo Ignacio (Association for Computing Machinery (ACM), 2016)
      Conference report
      Restricted access - publisher's policy
      The Delaunay triangulation is the standard choice for building triangulated irregular networks (TINs) to represent terrain surfaces. However, the Delaunay triangulation is based only on the 2D coordinates of the data points, ...
    • Improving shortest paths in the Delaunay triangulation 

      Abellanas, Manuel; Claverol Aguas, Mercè; Hernández-Peñalver, Gregorio; Hurtado Díaz, Fernando Alfredo; Sacristán Adinolfi, Vera; Saumell Mendiola, Maria; Silveira, Rodrigo Ignacio (2012)
      Article
      Open Access
      We study a problem about shortest paths in Delaunay triangulations. Given two nodes s, t in the Delaunay triangulation of a point set P, we look for a new point p that can be added, such that the shortest path from s to ...
    • Map construction algorithms: an evaluation through hiking data 

      Duran, David; Sacristán Adinolfi, Vera; Silveira, Rodrigo Ignacio (Association for Computing Machinery (ACM), 2017)
      Conference report
      Restricted access - publisher's policy
      We study five existing map construction algorithms, designed and tested with urban vehicle data in mind, and apply them to hiking trajectories with different terrain characteristics. Our main goal is to better understand ...
    • Matching points with diametral disks 

      Huemer, Clemens; Pérez-Lantero, Pablo; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2017)
      Conference report
      Open Access
      We consider matchings between a set R of red points and a set B of blue points with diametral disks. In other words, for each pair of matched points p ¿ R and q ¿ B, we consider the diametral disk defined by p and q. We ...
    • Matching points with disks with a common intersection 

      Huemer, Clemens; Pérez Lantero, Pablo; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2019-07-01)
      Article
      Restricted access - publisher's policy
      We consider matchings with diametral disks between two sets of points R and B. More precisely, for each pair of matched points p ¿ R and q ¿ B, we consider the disk through p and q with the smallest diameter. We prove that ...
    • Median trajectories 

      Buchin, Kevin; Buchin, Maike; Kreveld, Marc van; Löffler, Maarten; Silveira, Rodrigo Ignacio; Wenk, Carola; Wiratma, Lionov (2012-05)
      Article
      Open Access
      We investigate the concept of a median among a set of trajectories. We establish criteria that a “median trajectory” should meet, and present two different methods to construct a median for a set of input trajectories. The ...
    • New results on production matrices for geometric graphs 

      Esteban Pascual, Guillermo; Huemer, Clemens; Silveira, Rodrigo Ignacio (2018-07-01)
      Article
      Open Access
      We present novel production matrices for non-crossing partitions, connected geometric graphs, and k-angulations, which provide another way of counting the number of such objects. For instance, a formula for the number of ...
    • New results on stabbing segments with a polygon 

      Díaz Bañez, José Miguel; Korman Cozzetti, Matías; Pérez Lantero, Pablo; Pilz, Alexander; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (Springer, 2013)
      Conference report
      Restricted access - publisher's policy
      We consider a natural variation of the concept of stabbing a segment by a simple polygon: a segment is stabbed by a simple polygon P if at least one of its two endpoints is contained in P. A segment set S is stabbed by P ...
    • New results on stabbing segments with a polygon 

      Díaz Bañez, José Miguel; Korman Cozzetti, Matías; Pérez Lantero, Pablo; Pilz, Alexander; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2015-01-01)
      Article
      Open Access
      We consider a natural variation of the concept of stabbing a set of segments with a simple polygon: a segment s is stabbed by a simple polygon P if at least one endpoint of s is contained in P, and a segment set S is stabbed ...
    • Non-crossing paths with geographic constraints 

      Silveira, Rodrigo Ignacio; Speckmann, Bettina; Verbeek, Kevin (Chapman & Hall/CRC, 2019-01-01)
      Article
      Open Access
      A geographic network is a graph whose vertices are restricted to lie in a prescribed region in the plane. In this paper we begin to study the following fundamental problem for geographic networks: can a given geographic ...
    • Non-crossing paths with geographic constraints 

      Silveira, Rodrigo Ignacio; Speckmann, Bettina; Verbeek, Kevin (Springer, 2018)
      Conference report
      Restricted access - publisher's policy
      A geographic network is a graph whose vertices are restricted to lie in a prescribed region in the plane. In this paper we begin to study the following fundamental problem for geographic networks: can a given geographic ...