Now showing items 1-20 of 28

  • Antimagic labelings of caterpillars 

    Lozano Bojados, Antoni; Mora Giné, Mercè; Seara Ojea, Carlos (2019-04-15)
    Article
    Restricted access - publisher's policy
    A k-antimagic labeling of a graph G is an injection from E(G) to {1,2, ..., |E(G)|+k} such that all vertex sums are pairwise distinct, where the vertex sum at vertex u is the sum of the labels assigned to edges incident ...
  • Balanced partitions of 3-colored geometric sets in the plane 

    Bereg, Sergey; Hurtado Díaz, Fernando Alfredo; Kano, Mikio; Korman, Matias; Lara, Dolores; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio; Urrutia Galicia, Jorge; Verbeek, Kevin (2015)
    Article
    Open Access
    Let SS be a finite set of geometric objects partitioned into classes or colors . A subset S'¿SS'¿S is said to be balanced if S'S' contains the same amount of elements of SS from each of the colors. We study several ...
  • Characteristic polynomials of production matrices for geometric graphs 

    Huemer, Clemens; Pilz, Alexander; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2017-08-01)
    Article
    Open Access
    An n×n production matrix for a class of geometric graphs has the property that the numbers of these geometric graphs on up to n vertices can be read off from the powers of the matrix. Recently, we obtained such production ...
  • Extremal graph theory for metric dimension and diameter 

    Hernando Martín, María del Carmen; Mora Giné, Mercè; Seara Ojea, Carlos; Wood, David (2010-02-22)
    Article
    Open Access
    A set of vertices S resolves a connected graph G if every vertex is uniquely determined by its vector of distances to the vertices in S. The metric dimension of G is the minimum cardinality of a resolving set of G. Let ...
  • Extremal graph theory for metric dimension and diameter 

    Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Seara Ojea, Carlos; Wood, David (2010)
    Article
    Open Access
  • Fitting a two-joint orthogonal chain to a point set 

    Díaz-Báñez, José Miguel; López, Mario A.; Mora Giné, Mercè; Seara Ojea, Carlos; Ventura, Inmaculada (2011-04)
    Article
    Open Access
    We study the problem of fitting a two-joint orthogonal polygonal chain to a set S of n points in the plane, where the objective function is to minimize the maximum orthogonal distance from S to the chain. We show that this ...
  • 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 things 

    Taslakian, Perouz; Seara Ojea, Carlos; Saumell Mendiola, Maria; Langerman, Stefan; Hurtado Díaz, Fernando Alfredo; Aloupis, Greg; Cardinal, Jean; Collette, Sébastien; Demaine, Erik D.; Demaine, Martin L.; Dulieu, Muriel; Fabila Monroy, Ruy; Hart, Vi (Springer Verlag, 2010)
    Conference report
    Restricted access - publisher's policy
    Given an ordered set of points and an ordered set of geometric objects in the plane, we are interested in finding a non-crossing matching between point-object pairs. We show that when the objects we match the points to ...
  • 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 ...
  • 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 ...
  • 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 monophonic sets in graphs 

    Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Seara Ojea, Carlos (2003)
    External 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 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 ...
  • 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 ...
  • 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 ...