Now showing items 21-40 of 49

    • 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 ...
    • On (a, k)-sets and (a, k)-hulls in the plane 

      Claverol Aguas, Mercè; Herrera Becerra, Luís Hernán; Seara Ojea, Carlos; Pérez Lantero, Pablo (2021)
      Conference report
      Open Access
      This abstract reports first the study of upper and lower bounds for the maximum number of all the combinatorially different (a, k)-sets of an n-point set P in the plane, 0 < a = p and 0 < 2k < n, depending on the ...
    • On computing enclosing isosceles triangles and related problems 

      Bose, Prosenjit; Mora Giné, Mercè; Seara Ojea, Carlos; Sethia, Saurabh (2011-02)
      Article
      Open Access
      Given a set of n points in the plane, we show how to compute various enclosing isosceles triangles where different parameters such as area or perimeter are optimized. We then study a 3-dimensional version of the problem ...
    • On geodetic sets formed by boundary vertices 

      Cáceres González, José; Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Puertas González, María Luz; Seara Ojea, Carlos (2003)
      Article
      Open Access
      Let G be a finite simple connected graph. A vertex v is a boundary vertex of G if there exists a vertex u such that no neighbor of v is further away from u than v. We obtain a number of properties involving different types ...
    • On Hamiltonian alternating cycles and paths 

      Claverol Aguas, Mercè; García, Alfredo; Garijo Royo, Delia; Seara Ojea, Carlos; Tejel, Javier (2018-03)
      Article
      Open Access
      We undertake a study on computing Hamiltonian alternating cycles and paths on bicolored point sets. This has been an intensively studied problem, not always with a solution, when the paths and cycles are also required to ...
    • On maximum-sum matchings of points 

      Bereg, Sergey; Chacón Rivera, Oscar; Flores Peñaloza, David; Huemer, Clemens; Pérez Lantero, Pablo; Seara Ojea, Carlos (Springer Nature, 2022-06-21)
      Article
      Open Access
      Huemer et al. (Discrete Mathematics, 2019) proved that for any two point sets R and B with |R|=|B| , the perfect matching that matches points of R with points of B, and maximizes the total squared Euclidean distance of the ...
    • On maximum-sum matchings of points 

      Bereg, Sergey; Chacón Rivera, Oscar; Flores Peñaloza, David; Huemer, Clemens; Pérez Lantero, Pablo; Seara Ojea, Carlos (2021)
      Conference report
      Restricted access - publisher's policy
      Huemer et al. (Discrete Math., 2019) proved that for any two point sets R and B with |R| = |B|, the perfect matching that matches points of R with points of B, and maximizes the total squared Euclidean distance of the ...
    • On monophonic sets in graphs 

      Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Seara Ojea, Carlos (2003)
      Research report
      Open Access
    • On the determining number and the metric dimension of graphs 

      Cáceres, Jose; Garijo, Delia; Puertas González, María Luz; Seara Ojea, Carlos (2010-04-19)
      Article
      Open Access
      This paper initiates a study on the problem of computing the difference between the metric dimension and the determining number of graphs. We provide new proofs and results on the determining number of trees and Cartesian ...
    • On the Oß-hull of a planar point set 

      Alegría Galicia, Carlos; Orden, David; Seara Ojea, Carlos; Urrutia Galicia, Jorge (2018-03-01)
      Article
      Open Access
      We study the Oß-hull of a planar point set, a generalization of the Orthogonal Convex Hull where the coordinate axes form an angle ß. Given a set P of n points in the plane, we show how to maintain the Oß-hull of P while ...
    • On the Steiner, geodetic and hull numbers of graphs 

      Hernando Martín, María del Carmen; Tao, Jiang; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Seara Ojea, Carlos (2003)
      Article
      Open Access
      Given a graph G and a subset W ? V (G), a Steiner W-tree is a tree of minimum order that contains all of W. Let S(W) denote the set of all vertices in G that lie on some Steiner W-tree; we call S(W) the Steiner interval ...
    • Optimizing generalized kernels of polygons 

      Martínez Moraian, Alejandra; Orden Martin, David; Palios, Leonidas; Seara Ojea, Carlos; Zylinski, Pawel (Springer Nature, 2021-04-09)
      Article
      Open Access
      Let O be a set of k orientations in the plane, and let P be a simple polygon in the plane. Given two points p, q inside P, we say that p O-sees q if there is an O-staircase contained in P that connects p and q. The O-Kernel ...
    • Production matrices for geometric graphs 

      Huemer, Clemens; Pilz, Alexander; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2016)
      Article
      Open Access
      We present production matrices for non-crossing geometric graphs on point sets in convex position, which allow us to derive formulas for the numbers of such graphs. Several known identities for Catalan numbers, Ballot ...
    • Separating bichromatic point sets in the plane by restricted orientation convex hulls 

      Alegría Galicia, Carlos; Orden Martin, David; Seara Ojea, Carlos; Urrutia Galicia, Jorge (2023-04-01)
      Article
      Open Access
      We explore the separability of point sets in the plane by a restricted-orientation convex hull, which is an orientation-dependent, possibly disconnected, and non-convex enclosing shape that generalizes the convex hull. Let ...
    • Some structural, metric and convex properties of the boundary of a graph 

      Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Seara Ojea, Carlos (2013-04-25)
      Article
      Open Access
      Let u;v be two vertices of a connected graph G . The vertex v is said to be a boundary vertex of u if no neighbor of v is further away from u than v . The boundary of a graph is the set of all its ...
    • Stabbers of line segments in the plane 

      Claverol Aguas, Mercè; Garijo, Delia; Grima, Clara; Márquez, Alberto; Seara Ojea, Carlos (2011-07)
      Article
      Open Access
      The problem of computing a representation of the stabbing lines of a set S of segments in the plane was solved by Edelsbrunner et al. We provide efficient algorithms for the following problems: computing the stabbing wedges ...
    • Stabbing circles for sets of segments in the plane 

      Claverol Aguas, Mercè; Khramtcova, Elena; Papadopoulou, Evanthia; Saumell, Maria; Seara Ojea, Carlos (2016)
      Conference report
      Restricted access - publisher's policy
      Stabbing a set S of n segments in the plane by a line is a well-known problem. In this paper we consider the variation where the stabbing object is a circle instead of a line. We show that the problem is tightly connected ...
    • Stabbing circles for sets of segments in the plane 

      Claverol Aguas, Mercè; Khramtcova, Elena; Papadopoulou, Evanthia; Saumell, Maria; Seara Ojea, Carlos (2017-03-13)
      Article
      Open Access
      Stabbing a set S of n segments in the plane by a line is a well-known problem. In this paper we consider the variation where the stabbing object is a circle instead of a line. We show that the problem is tightly connected ...
    • Stabbing circles for some sets of Delaunay segments 

      Claverol Aguas, Mercè; Khramtcova, Elena; Papadopoulou, Evanthia; Saumell, Maria; Seara Ojea, Carlos (2016)
      Conference report
      Open Access
      Let S be a set of n segments in the plane such that, for every segment, its two endpoints are adjacent in the Delaunay triangulation of the set of endpoints of all segments in S. Our goal is to compute all the combinatorially ...