Now showing items 1-20 of 69

    • Presentation
      Icon

      A symbolic-numeric dynamic geometry environment for the computation of equidistant curves 

      Abánades Astudillo, Miguel Ángel; Botana Ferreiro, Francisco (2013)
      A web-based system that determines point/curve and curve/curve bisectors in a dynamic geometry system in a completely ...
    • Presentation
      Icon

      Abstract Voronoi diagrams 

      Klein, Rolf (2013)
      Abstract Voronoi diagrams are a unifying framework that covers many types of concrete Voronoi diagrams. This talk reports on the state of the art, including recent progress.
    • Presentation
      Icon

      An algorithm that constructs irreducible triangulations of once-punctured surfaces 

      Chávez de Diego, María José; Lawrecenko, Serge; Portillo Fernández, José Ramón; Villar Liñán, María Trinidad (2013)
      A triangulation of a surface is irreducible if there is no edge whose contraction produces another triangulation of the ...
    • Presentation
      Icon

      Computing Optimal Shortcuts for Networks 

      Garijo Royo, Delia; Márquez Pérez, Alberto; Rodríguez, Natalia; Silveira, Rodrigo I. (Dagsthul Publishing, 2018)
      We study augmenting a plane Euclidean network with a segment, called shortcut, to minimize the largest distance between ...
    • Presentation
      Icon

      Computing the stretch of an embedded graph 

      Cabello Justo, Sergio; Chimani, Markus; Hliněný, Petr (2013)
      Let G be a graph embedded in an orientable surface Σ, possibly with edge weights, and denote by len(γ) the length (the ...
    • Article
      Icon

      Computing the Tutte polynomial of Archimedean tilings 

      Garijo Royo, Delia; Gegúndez, M.E.; Márquez Pérez, Alberto; Revuelta Marchena, María Pastora; Sagols, F. (2014)
      We describe an algorithm to compute the Tutte polynomial of large fragments of Archimedean tilings by squares, triangles, ...
    • Article
      Icon

      Continuous mean distance of a weighted graph 

      Garijo Royo, Delia; Márquez Pérez, Alberto; Silveira, Rodrigo I. (Cornell University, 2021)
      We study the concept of the continuous mean distance of a weighted graph. For connected unweighted graphs, the mean ...
    • Presentation
      Icon

      Continuous surveillance of points by rotating floodlights 

      Bereg, Sergey; Díaz Báñez, José Miguel; Fort i Masdevall, Marta; Lopez, Mario A.; Pérez Lantero, Pablo; Urrutia Galicia, Jorge (2013)
      Let P and F be sets of n ≥ 2 and m ≥ 2 points in the plane, respectively, so that P∪F is in general position. We study the ...
    • Article
      Icon

      Contractors for flows 

      Garijo Royo, Delia; Goodall, Andrew; Nešetřil, Jaroslav (Elsevier, 2011)
      We answer a question raised by Lovász and B. Szegedy [Contractors and connectors in graph algebras, J. Graph Theory 60:1 ...
    • Presentation
      Icon

      Distance domination, guarding and vertex cover for maximal outerplanar graphs 

      Canales Cano, Santiago; Hernández Peñalver, Gregorio; Oliveira Martins, Ana Mafalda de; Matos. Inês (2013)
      In this paper we de ne a distance guarding concept on plane graphs and associate this concept with distance domination and ...
    • Article
      Icon

      Distinguishing graphs by their left and right homomorphism profiles 

      Garijo Royo, Delia; Goodall, Andrew; Nešetřil, Jaroslav (Elsevier, 2011)
      We introduce a new property of graphs called ‘q-state Potts unique-ness’ and relate it to chromatic and Tutte uniqueness, ...
    • Presentation
      Icon

      Drawing the double circle on a grid of minimum size 

      Bereg, Sergey; Fabila Monroy, Ruy; Flores Peñaloza, David; Lopez, Mario A.; Pérez Lantero, Pablo (2013)
      In 1926, Jarník introduced the problem of drawing a convex n-gon with vertices having integer coordinates. He constructed ...
    • Presentation
      Icon

      Empty convex polytopes in random point sets 

      Balogh, József; González Aguilar, Hernán; Salazar Anaya, Gelasio (2013)
      Given a set P of points in Rd, a convex hole (alternatively, empty convex polytope) of P is a convex polytope with vertices ...
    • Presentation
      Icon

      Equipartitioning triangles 

      Ramos Alonso, Pedro Antonio; Steiger, William (2013)
      An intriguing conjecture of Nandakumar and Ramana Rao is that for every convex body K ⊆ R2, and for any positive integer ...
    • Presentation
      Icon

      Flips in combinatorial pointed pseudo-triangulations with face degree at most four 

      Aichholzer, Oswin; Hackl, Thomas; Orden Martín, David; Pilz, Alexander; Saumell Mendiola, María; Vogtenhuber, Birgit (2013)
      In this paper we consider the flip operation for combinatorial pointed pseudo-triangulations where faces have size 3 or ...
    • Article
      Icon

      Graph homomorphisms, the Tutte polynomial and “q-state Potts uniqueness” 

      Garijo Royo, Delia; Goodall, Andrew; Nesetril, Jaroslav (Elsevier, 2009)
      We establish for which weighted graphs H homomorphism functions from multigraphs G to H are specializations of the Tutte ...
    • Presentation
      Icon

      Guarding the vertices of thin orthogonal polygons is NP-hard 

      Nunes Gomes Tomás, Ana Paula (2013)
      An orthogonal polygon of P is called “thin” if the dual graph of the partition obtained by extending all edges of P towards ...
    • Article
      Icon

      Hexagonal Tilings and Locally C6 Graphs 

      Garijo Royo, Delia; Gitler, I.; Márquez Pérez, Alberto; Revuelta Marchena, María Pastora (Cornell University, 2005)
      We give a complete classification of hexagonal tilings and locally C6 graphs, by showing that each of them has a natural ...
    • Article
      Icon

      Hexagonal Tilings: Tutte Uniqueness 

      Garijo Royo, Delia; Márquez Pérez, Alberto; Revuelta Marchena, María Pastora (Cornell University, 2005)
      We develop the necessary machinery in order to prove that hexagonal tilings are uniquely determined by their Tutte polynomial, showing as an example how to apply this technique to the toroidal hexagonal tiling.
    • Presentation
      Icon

      Homomorphisms and Polynomial Invariants of Graphs 

      Revuelta Marchena, María Pastora; Garijo Royo, Delia; Nesetril, Jaroslav (2007)
      This paper initiates a study of the connection between graph homomorphisms and the Tutte polynomial. This connection ...