Exploració per autor "Huemer, Clemens"
Ara es mostren els items 19-38 de 73
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Large bichromatic point sets admit empty monochromatic 4-gons
Aichholzer, Oswin; Hackl, Thomas; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Vogtenhuber, Birgit (2009)
Text en actes de congrés
Accés obertWe consider a variation of a problem stated by Erd˝os and Szekeres in 1935 about the existence of a number fES(k) such that any set S of at least fES(k) points in general position in the plane has a subset of k points that ... -
Lower bounds for the number of small convex k-holes
Aichholzer, Oswin; Fabila Monroy, Ruy; Hackl, Thomas; Huemer, Clemens; Pilz, Alexander; Vogtenhuber, Birgit (2014-07-01)
Article
Accés obertLet S be a set of n points in the plane in general position, that is, no three points of S are on a line. We consider an Erdos-type question on the least number h(k)(n) of convex k-holes in S, and give improved lower bounds ... -
Lower bounds on the maximum number of non-crossing acyclic graphs
Huemer, Clemens; Mier Vinué, Anna de (2015-08-01)
Article
Accés obertThis paper is a contribution to the problem of counting geometric graphs on point sets. More concretely, we look at the maximum numbers of non-crossing spanning trees and forests. We show that the so-called double chain ... -
Matching points with diametral disks
Huemer, Clemens; Pérez-Lantero, Pablo; Seara Ojea, Carlos; Silveira, Rodrigo Ignacio (2017)
Text en actes de congrés
Accés obertWe 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
Accés obertWe 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 ... -
Matching random colored points with rectangles
Corujo, Josué; Flores Peñaloza, David; Huemer, Clemens; Seara Ojea, Carlos; Pérez Lantero, Pablo (Springer, 2020)
Text en actes de congrés
Accés obertLet S[0,1]2 be a set of n points, randomly and uniformly selected. Let RB be a random partition, or coloring, of S in which each point of S is included in R uniformly at random with probability 1/2. We study the random ... -
Matching random colored points with rectangles
Corujo, Josué; Flores Peñazola, David; Huemer, Clemens; Pérez Lantero, Pablo; Seara Ojea, Carlos (Universitat de Girona, 2019)
Comunicació de congrés
Accés obertLet S ¿ [0, 1]2 be a set of n points, randomly and uniformly selected. Let R ¿ B be a random partition, or coloring, of S in which each point of S is included in R uniformly at random with probability 1/2. We study the ... -
Matching random colored points with rectangles
Corujo, Josué; Flores Peñaloza, David; Huemer, Clemens; Pérez Lantero, Pablo; Seara Ojea, Carlos (Springer, 2023-03-14)
Article
Accés obertGiven n > 0, let S ¿ [0,1]2 be a set of n points, chosen uniformly at random. Let R¿B be a random partition, or coloring, of S in which each point of S is included in R uniformly at random with probability 1/2. We study ... -
Maximizing maximal angles for plane straight-line graphs
Aichholzer, Oswin; Hackl, Thomas; Hoffmann, Michael; Huemer, Clemens; Pór, Attila; Santos, Francisco; Speckmann, Bettina; Vogtenhuber, Birgit (2013-01)
Article
Accés restringit per política de l'editorialLet G=(S,E) be a plane straight-line graph on a finite point set S⊂R2 in general position. The incident angles of a point p∈S in G are the angles between any two edges of G that appear consecutively in the circular order ... -
Measuring cocircularity in a point set
Heras Parrilla, Andrea de las; Esteban, Guillermo; Garijo Royo, Delia; Huemer, Clemens; Lozano Boixadors, Antoni; Oliver, Nicolau; Orden Martin, David (2023)
Text en actes de congrés
Accés obertIn a given set S of n points in the plane, how close are four points of S to be cocircular? We define several measures to study this question, and present bounds on this almost-cocircularity in a point set. Algorithms for ... -
Modem illumination of monotone polygons
Aichholzer, Oswin; Fabila Monroy, Ruy; Flores Peñaloza, David; Hackl, Thomas; Huemer, Clemens; Urrutia Galicia, Jorge; Vogtenhuber, Birgit (2009)
Text en actes de congrés
Accés obertWe study a generalization of the classical problem of illumination of polygons. Instead of modeling a light source we model a wireless device whose radio signal can penetrate a given number k of walls. We call these ... -
Moving rectangles
García, Alfredo; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, F. Javier (2010)
Text en actes de congrés
Accés obertConsider a set of n pairwise disjoint axis-parallel rectangles in the plane. We call this set the source rectangles S. The aim is to move S to a set of (pairwise disjoint) target rectangles T . A move consists in a ... -
New cyclic Kautz digraphs with optimal diameter
Böhmová, Katerina; Dalfó Simó, Cristina; Huemer, Clemens (2021)
Article
Accés obertWe obtain a new family of digraphs with minimal diameter, that is, given the number of vertices and out-degree, there is no other digraph with a smaller diameter. This new family of digraphs are called `modified cyclic ... -
New production matrices for geometric graphs
Esteban Pascual, Guillermo; Huemer, Clemens; Silveira, Rodrigo Ignacio (Elsevier, 2022-01-15)
Article
Accés obertWe use production matrices to count several classes of geometric graphs. We present novel production matrices for non-crossing partitions, connected geometric graphs, and k-angulations, which provide another, simple and ... -
New results on production matrices for geometric graphs
Esteban Pascual, Guillermo; Huemer, Clemens; Silveira, Rodrigo Ignacio (2018-07-01)
Article
Accés obertWe 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 ... -
Note on the number of obtuse angles in point sets
Fabila-Monroy, Ruy; Huemer, Clemens; Tramuns, Eulàlia (2014-09)
Article
Accés obertIn $1979$ Conway, Croft, Erd\H{o}s and Guy proved that every set $S$ of $n$ points in general position in the plane determines at least $\frac{n^3}{18}-O(n^2)$ obtuse angles and also presented a special set of $n$ points ... -
On circles enclosing many points
Claverol Aguas, Mercè; Huemer, Clemens; Martínez Moraian, Alejandra (2021-10-01)
Article
Accés obertWe prove that every set of n red and n blue points in the plane contains a red and a blue point such that every circle through them encloses at least points of the set. This is a two-colored version of a problem posed by ... -
On cyclic Kautz digraphs
Böhmová, Katerina; Dalfó Simó, Cristina; Huemer, Clemens (2015)
Report de recerca
Accés obertA prominent problem in Graph Theory is to find extremal graphs or digraphs with restrictions in their diameter, degree and number of vertices. Here we obtain a new family of digraphs with minimal diameter, that is, given ... -
On k-gons and k-holes in point sets
Aichholzer, Oswin; Fabila Monroy, Ruy; Gonzalez Aguilar, Hernan; Hackl, Thomas; Heredia, Marco A.; Huemer, Clemens; Urrutia Galicia, Jorge; Valtr, Pavel; Vogtenhuber, Birgit (2015-08-01)
Article
Accés obertWe consider a variation of the classical Erdos-Szekeres problems on the existence and number of convex k-gons and k-holes (empty k-gons) in a set of n points in the plane. Allowing the k-gons to be non-convex, we show ... -
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
Accés obertHuemer 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 ...