Browsing by Author "Hurtado Díaz, Fernando Alfredo"
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A polynomial bound for untangling geometric planar graphs
Bose, Prosenjit; Dujmovic, Vida; Hurtado Díaz, Fernando Alfredo; Langerman, Stefan; Morin, Pat; Wood, David (200912)
Article
Open AccessTo untangle a geometric graph means to move some of the vertices so that the resulting geometric graph has no crossings. Pach and Tardos (Discrete Comput. Geom. 28(4): 585–592, 2002) asked if every nvertex geometric planar ... 
Balanced partitions of 3colored 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 AccessLet 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 ... 
Blocking the kholes of point sets in the plane
Cano, Javier; Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Shakai, Toshinori; Tejel Altarriba, Francisco Javier; Urrutia Galicia, Jorge (201509)
Article
Open AccessLet P be a set of n points in the plane in general position. A subset H of P consisting of k elements that are the vertices of a convex polygon is called a khole of P, if there is no element of P in the interior of its ... 
Cellpaths in mono and bichromatic line arrangements in the plane
Aichholzer, Oswin; Cardinal, Jean; Hackl, Thomas; Hurtado Díaz, Fernando Alfredo; Korman Cozzetti, Matías; Pilz, Alexander; Silveira, Rodrigo Ignacio; Uehara, Ryuhei; Vogtenhuber, Birgit; Welzl, Emo (2014)
Conference report
Open AccessWe show that in every arrangement of n red and blue lines  in general position and not all of the same color  there is a path through a linear number of cells where red and blue lines are crossed alternatingly (and no ... 
Colored Ray configurations
Fabila Monroy, Ruy; Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Jaume, Rafel; Pérez Lantero, Pablo; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Urrutia Galicia, Jorge (2014)
Conference report
Open AccessWe study the cyclic sequences induced at in nity by pairwisedisjoint colored rays with apices on a given bal anced bichromatic point set, where the color of a ray is inherited from the color of its apex. We derive a lower ... 
Colored ray configurations
Fabila Monroy, Ruy; Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Jaume, Rafel; Pérez Lantero, Pablo; Saumell, Maria; Silveira, Rodrigo Ignacio; Tejel Altarriba, Francisco Javier; Urrutia Galicia, Jorge (201805)
Article
Open AccessWe study the cyclic color sequences induced at infinity by colored rays with apices being a given balanced finite bichromatic point set. We first study the case in which the rays are required to be pairwise disjoint. We ... 
Colored spanning graphs for set visualization
Hurtado Díaz, Fernando Alfredo; Korman, Matias; Van Kreveld, Matias; Löffler, Maarten; Sacristán Adinolfi, Vera; Shioura, Akiyoshi; Silveira, Rodrigo Ignacio; Speckmann, Bettina; Tokuyama, Takeshi (201803)
Article
Open AccessWe study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the ... 
Colored spanning graphs for set visualization
Hurtado Díaz, Fernando Alfredo; Korman Cozzetti, Matías; Van Kreveld, Matias; Löffler, Maarten; Sacristán Adinolfi, Vera; Silveira, Rodrigo Ignacio; Speckmann, Bettina (Springer, 2013)
Conference report
Open AccessWe study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the ... 
Compatible matchings in geometric graphs
Aichholzer, Oswin; García Olaverri, Alfredo; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, F. Javier (Centre de Recerca Matemàtica, 2011)
Conference report
Open AccessTwo noncrossing geometric graphs on the same set of points are compatible if their union is also noncrossing. In this paper, we prove that every graph G that has an outerplanar embedding admits a noncrossing perfect ... 
Compatible spanning trees
Garcia Olaverri, Alfredo Martin; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, Francisco Javier (20140701)
Article
Open AccessTwo plane geometric graphs are said to be compatible when their union is a plane geometric graph. Let S be a set of n points in the Euclidean plane in general position and let T be any given plane geometric spanning tree ... 
Configurations of noncrossing rays and related problems
Garcia Olaverri, Alfredo Martin; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, Francisco Javier; Urrutia Galicia, Jorge (201604)
Article
Open AccessLet S be a set of n points in the plane and let R be a set of n pairwise noncrossing rays, each with an apex at a different point of S. Two sets of noncrossing rays R1R1 and R2R2 are considered to be different if the ... 
Connectivitypreserving transformations of binary images
Bose, Prosenjit; Dujmovic, Vida; Hurtado Díaz, Fernando Alfredo; Morin, Pat (200910)
Article
Open AccessA binary image $\emph{I}$ is $B_a$, $W_b$connected, where $\emph{a,b}$ ∊ {4,8}, if its foreground is $\emph{a}$connected and its background is $\emph{b}$connected. We consider a local modification of a $B_a$, $W_b$connected ... 
Coverage with ktransmitters in the presence of obstacles
Uehara, R.; Souvaine, D.; Sacristán Adinolfi, Vera; Morin, P.; Lubiw, A.; Iacono, J.; Ballinger, B.; Benbernou, N.; Bose, P.; Damian, M.; Demaine, E. D.; Dujmovic, Vida; Flatland, R.; Hurtado Díaz, Fernando Alfredo (Springer Verlag, 2010)
Conference report
Restricted access  publisher's policyFor a fixed integer k ≥ 0, a ktransmitter is an omnidirectional wireless transmitter with an infinite broadcast range that is able to penetrate up to k “walls”, represented as line segments in the plane. We develop lower ... 
Distance 2domination in prisms of graphs
Hurtado Díaz, Fernando Alfredo; Mora Giné, Mercè; Rivera Campo, Eduardo; Zuazua Vega, Rita Esther (20170101)
Article
Open AccessA set of vertices D of a graph G is a distance 2dominating set of G if the distance between each vertex u ¿ ( V ( G )  D ) and D is at most two. Let ¿ 2 ( G ) denote the size of a smallest distance 2 dominating set of ... 
EdgeRemoval and NonCrossing Configurations in Geometric Graphs
Aichholzer, Oswin; Cabello, Sergio; Fabila Monroy, Ruy; Flores Peñaloza, David; Hackl, Thomas; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Wood, David (2010)
Article
Open AccessA geometric graph is a graph G = (V;E) drawn in the plane, such that V is a point set in general position and E is a set of straightline segments whose endpoints belong to V . We study the following extremal problem for ... 
Every large point set contains many collinear points or an empty pentagon
Wood, David; Por, Attila; Abel, Zachary; Ballinger, Brad; Bose, Prosenjit; Collette, Sébastien; Dujmovic, Vida; Hurtado Díaz, Fernando Alfredo; Kominers, Scott Duke; Langerman, Stefan (201101)
Article
Restricted access  publisher's policyWe prove the following generalised empty pentagon theorem for every integer ℓ ≥ 2, every sufficiently large set of points in the plane contains ℓ collinear points or an empty pentagon. As an application, we settle the next ... 
GEOMETRIA (Examen 1r quadrim)
Hurtado Díaz, Fernando Alfredo (Universitat Politècnica de Catalunya, 20081106)
Exam
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GEOMETRIA (Examen 1r quadrim)
Hurtado Díaz, Fernando Alfredo (Universitat Politècnica de Catalunya, 20081106)
Exam
Restricted access to the UPC academic community 
GEOMETRIA (Examen 1r quadrim)
Hurtado Díaz, Fernando Alfredo (Universitat Politècnica de Catalunya, 20090119)
Exam
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GEOMETRIA DISCRETA I COMPUTACIONAL (Examen 1r quadrim)
Hurtado Díaz, Fernando Alfredo (Universitat Politècnica de Catalunya, 20051124)
Exam
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