Illuminating Triangles and Quadrilaterals with Vertex Floodlights (2009)
Felipe Contreras, Jurek Czyzowicz, Nicolas Fraiji, Jorge Urrutia
We show that three π/6 vertex floodlights suffice to illuminate any triangle, and we prove that any quadrilateral can be illuminated by three π/4 vertex floodlights. 1
Modem Illumination of Monotone Polygons (2009)
Oswin Aichholzer, Ruy Fabila-monroy, David Flores-peñaloza, Thomas Hackl, Clemens Huemer, Jorge Urrutia, ...
We 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...
Fabila-Monroy, Ruy, Flores-Peñaloza, David, Huemer, Clemens, Hurtado, Ferran, Urrutia, Jorge, Wood, David R.
For a graph $G$ and integer $k\geq1$, we define the token graph $F_k(G)$ to be the graph with vertex set all $k$-subsets of $V(G)$, where two vertices are adjacent in $F_k(G)$ whenever their...
Abstract Chapter 51 The Aquarium Keeper’s Problem* (2009)
Jurek Czyzowiczt, Peter Egyed, Hazel Everew, Thomas Sherrnert, Diane Souvainell, Godfried Toussaint, ...
We solve the problem of computing the shortest closed path inside a given polygon which visits every edge at least once (Aquarium Z{eeper’s Tour). For convex polygons, we present a linear-time...
Games on Triangulations (2009)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
Abstract. We analyze several perfect-information combinatorial games played on planar triangulations. We introduce three broad categories of such games—constructing, transforming, and marking...
Geometric Games on Triangulations Extended Abstract (2009)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
Let S be a set of n points in the plane, which we assume to be in general position, i.e., no three points of S lie on the same line. A triangulation of S is a simplicial decomposition of its convex...
Geometric Games on Triangulations Extended Abstract (2009)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
1 Introduction Let S be a set of n points in the plane, which we assume to be in general position, i.e., no threepoints of S lie on the same line. A triangulation of S is a simplicial decomposition...
Playing with Triangulations (2008)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
Abstract. We analyze several perfect-information combinatorial games played on planar triangulations. We introduce three broad categories of such games: constructing, transforming, and marking...
Geometric Games on Triangulations Extended Abstract (2008)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
Let S be a set of n points in the plane, which we assume to be in general position, i.e., no three points of S lie on the same line. A triangulation of S is a simplicial decomposition of its convex...
Sergio Cabello, J. Miguel, J. Antoni Sellarès, Jorge Urrutia, Inma Ventura
We study the following problem: Given a set of red points and a set of blue points on the plane, find two unit disks CR and CB with disjoint interiors such that the number of red points covered by CR...
On the Chromatic Numbers of some Flip Graphs (2008)
Ruy Fabila-monroy, David Flores-peñaloza, Clemens Huemer, Ferran Hurtado, Jorge Urrutia, David R. Wood
This paper studies the chromatic number of the following four flip graphs (under suitable definitions of a flip): • the flip graph of perfect matchings of a complete graph of even order, • the...
Technology and Complex Systems) grants (2008)
Constantinos Georgiou, Ricardo Marcelín-jiménez, Sergio Rajsbaum, Jorge Urrutia
contract Marina-CONACyT
Abstract Routing with Guaranteed Delivery in ad hoc Wireless Networks* (2008)
Prosenjit Bose, Pat Morin, Jorge Urrutia
We consider routing problems in ad hoc wireless net-works modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the dis-tance between them is less than some...
1 Introduction Some Open Problems (2008)
In this paper we present a collection of problems which have defied solution for some time. We hope that this paper will stimulate renewed interest in
Bichromatic Quadrangulations with Steiner Points (2008)
Victor Alvarez, Toshinori Sakai, Jorge Urrutia
Abstract. Let P be a k colored point set in general position, k ≥ 2. A family of quadrilaterals with disjoint interiors Q1,..., Qm is called a quadrangulation of P if V (Q1) ∪...∪V (Qm) = P,...
Separating Collections of Points in Euclidean Spaces (2008)
Given two disjoint convex sets A and B in E d, a hyperplane h in E d separates them if A lies on one of the half spaces defined by h while B lies on the complementary half space. Given a collection F...
Jurek Czyzowicz, Evangelos Kranakis, Jorge Urrutia
We study a problem of dissecting a rectangle into a minimum number of pieces which may be reassembled into a square. The dissection is made using only rectilinear glass-cuts, i.e., vertical or...
Representing Orders on the Plane by Translating Convex (2008)
How may a robot arm be moved to pick up a particular object from a crowded shelf without unwanted collisions? How may a cluster of figures on a computer screen be shifted about to clear the screen...
Scheduling Tasks with Communication (2008)
Delays on Parallel Processors Let Jn={v1,...,vn} be a set of n jobs to be executed and E a set of precedence constraints on Jn. Assume that we have available a set
On Tilable Orthogonal Polygons ∗ (2008)
György Csizmadia, Jurek Czyzowicz, Evangelos Kranakis, Eduardo Rivera-campo, Jorge Urrutia
We consider rectangular tilings of orthogonal polygons with vertices located at integer lattice points. Let G be a set of reals closed under the usual addition operation. A G-rectangle is a rectangle...
Sergio Cabello, J. Miguel, J. Antoni Sellarès, Jorge Urrutia, Inma Ventura
We study the following problem: Given a set of red points and a set of blue points on the plane, find two unit disks CR and CB with disjoint interiors such that the number of red points covered by CR...
Constantinos Georgiou, Evangelos Kranakis, Ricardo Marcelín-jiménez, Rajsbaum Jorge Urrutia, Sergio Rajsbaum, Jorge Urrutia
This paper assumes a set of identical wireless hosts, each one aware of its location. The network is described by a unit distance graph whose vertices are points on the plane two of which are...
Optimal Guarding of Polygons and Monotone Chains (Extended Abstract) (2008)
Danny Z. Chen, Vladimir Estivill-Castro, Jorge Urrutia
) Danny Z. Chen Vladimir Estivill-Castro y Jorge Urrutia z Abstract In this paper we study several problems concerning the guarding of a polygon or a x- monotone polygonal chain P with n vertices...
Games on Triangulations (2008)
Oswin Aichholzer David, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
We analyze several perfect-information combinatorial games played on planar triangulations. We introduce three broad categories of such games---constructing, transforming, and marking...
Matching points with squares (2008)
Bernardo M. Ábrego, Esther M. Arkin, Silvia Fernández-merchant, Ferran Hurtado, Mikio Kano, ...
Given a class C of geometric objects and a point set P, a C-matching of P is a set M = {C1,...,Ck} ⊆ C of elements of C such that each Ci contains exactly two elements of P and each element of P...
Domino Tilings of Orthogonal Polygons (2007)
Gyorgy Csizmadia, Jurek Czyzowicz, Leszek Gasieniec, Evangelos Kranakis, Jorge Urrutia
We consider orthogonal polygons with vertices located at integer lattice points. We show that if all of the sides of a simple orthogonal polygon without holes have odd lengths, then it cannot be...
Domino Tilings of Orthogonal Polygons (2007)
György Csizmadia, Jurek Czyzowicz, Leszek Gasieniec, Evangelos Kranakis, Jorge Urrutia
We consider orthogonal polygons with vertices located at integer lattice points. We show that if all of the sides of a simple orthogonal polygon without holes have odd lengths, then it cannot be...
Illumination of Polygons with Vertex Lights (2007)
Vladimir Estivill-Castro, Jorge Urrutia, Dianna Xu
We show that vertex floodlights of angle ß suffice to illuminate any polygon, and that no angle less than ß suffices for all polygons. A vertex floodlight of angle ff is an internal cone of light...
Internal, External, and Mixed Visibility Edges of Polygons (2007)
Jay Bagga, Laxmi Gewali, Simeon Ntafos, Jorge Urrutia
In this paper we consider bounds on the number of edges connecting non-consecutive vertices of a polygon by dividing them into three types: internal, external, and mixed visibility edges. The main...
Illumination with Orthogonal Floodlights (Extended Abstract) (2007)
James Abello, Vladimir Estivill-Castro, Thomas Shermer, Jorge Urrutia
We provide the first tight bound for covering a polygon with n vertices and h holes with vertex guards. In particular, we provide tight bounds for the number of floodlights, placed at vertices or on...
Playing with Triangulations (2007)
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
Abstract. We analyze several perfect-information combinatorial games played on planar triangulations. We introduce three broad categories of such games: constructing, transforming, and marking...
Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
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Oswin Aichholzer, David Bremner, Erik D. Demaine, Ferran Hurtado, Evangelos Kranakis, Hannes Krasser, ...
9 1
On k-Guarding of Polygons (2007)
Patrice Belleville, Jurek Czyzowicz, Jorge Urrutia, Joseph Zaks
A polygon is called k-guardable if it is possible to find a collection G of points in the interior of the edges of P such that every point in P is visible from at least k elements of G, and such that...
We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some xed...
Prosenjit Bose, Pat Morin, Jorge Urrutia
We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some xed...
A Simpler Circular Ray Shooting Algorithm (2007)
Ralph P. Boland, Jorge Urrutia
The circular ray shooting problem is to preprocess a simple polygon P so that, for a query directed circular arc , one can quickly compute the rst intersection point (if any) of on P. We present a...
Olivier Devillers, Jorge Urrutia, Mariette Yvinec, Communicated F. Preparata
A circle C separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
A Simpler Circular Ray Shooting Algorithm (2007)
Ralph P. Boland, Jorge Urrutia
The circular ray shooting problem is to preprocess a simple polygon P so that, for a query directed circular arc , one can quickly compute the rst intersection point (if any) of on P. We present a...
159 Session C5.2 12th Canadian Conference on Computational Geometry Polygon Area Problems (2007)
Ralph P. Boland, Jorge Urrutia
In this paper we study the problem of preprocessing a simple polygon so that, for any query chord of the polygon, the area of the subpolygons determined by the chord can be determined quickly. We...
Ralph P. Boland, Jorge Urrutia
The circular ray shooting problem is to preprocess a simple polygon P so that, for a query directed circular arc , one can quickly compute the rst intersection point (if any) of on P. In a paper...
Ferran Hurtado, Marc Noy, Aplicada Ii, Jorge Urrutia
this paper is to show that this is indeed the case
Compatible Geometric Matchings (2007)
Aichholzer, Oswin, Bereg, Sergey, Dumitrescu, Adrian, García, Alfredo, Huemer, Clemens, Hurtado, Ferran, ...
This paper studies non-crossing geometric perfect matchings. Two such perfect matchings are \emph{compatible} if they have the same vertex set and their union is also non-crossing. Our first result...
Compatible Geometric Matchings (2007)
Oswin Aichholzer, Sergey Bereg, Adrian Dumitrescu, Alfredo García, Clemens Huemer, Ferran Hurtado, ...
Abstract: This paper studies non-crossing geometric perfect matchings. Two such perfect matchings are compatible if they have the same vertex set and their union is also non-crossing. Our first...
Simple Euclidean arrangements with no ( ≥ 5)–gons (2007)
Jesús Leaños, Mario Lomelí, Criel Merino, Gelasio Salazar, Jorge Urrutia
It is shown that if a simple Euclidean arrangement of n pseudolines has no ( ≥ 5)–gons, then it has exactly n − 2 triangles and (n − 2)(n − 3)/2 quadrilaterals. We also describe how to...
Matching points with geometric objects: Combinatorial results (2005)
Bernardo M. Ábrego, Esther Arkin, Silvia Fernández-merchant, Ferran Hurtado, Mikio Kano, ...
Abstract. Given a class C of geometric objects and a point set P,aCmatching of P is a set M = {C1,...,Ck} of elements of C such that every Ci contains exactly two elements of P. If all the elements...
Half-space proximal: A new local test for extracting a bounded dilation spanner (2005)
Edgar Chavez, Stefan Dobrev, Evangelos Kranakis, Jaroslav Opatrny, Ladislav Stacho, Héctor Tejeda, ...
Abstract. We give a new local test, called a Half-Space Proximal or HSP test, for extracting a sparse directed or undirected subgraph of a given unit disk graph. The HSP neighbors of each vertex are...
Matching points with geometric objects: Combinatorial results (2005)
Bernardo Ábrego, Esther Arkin, Silvia Fernández, Ferran Hurtado, Mikio Kano, ...
Abstract. Given a class C of geometric objects and a point set P,aCmatching of P is a set M = {C1,...,Ck} of elements of C such that every Ci contains exactly two elements of P. If all the elements...
Análisis de la conducta temporal de los ADRs latinoamericanos (2001)
Este artículo investiga las propiedades de la serie temporal de los retornos de una cartera de American Depositary Receipts, ADRs, de firmas latinoamericanas. Específicamente, investigamos la...
Finding the Largest Axisaligned Rectangle in a Polygon in O(nlog n) Time (2001)
Ralph P. Boland, Jorge Urrutia
We consider the problem of nding the largest area axis-aligned rectangle contained in an n vertex polygon. We present an algorithm that solves this problem in O(n log n) time. This is an improvement...
Finding the Largest Axisaligned Rectangle in a Polygon in O(nlog n) Time (2001)
Ralph P. Boland, Jorge Urrutia
We consider the problem of nding the largest area axis-aligned rectangle contained in an n vertex polygon. We present an algorithm that solves this problem in O(n log n) time. This is an improvement...
De la literatura al cine : teoría y análisis de la adaptación (2000)
Sánchez Noriega, José Luis, Urrutia, Jorge (pról.)
84-493-0896-8
Computing Largest Circles Separating Two Sets of Segments (2000)
Boissonnat, Jean-Daniel, Czyzowicz, Jurek, Devillers, Olivier, Urrutia, Jorge, Yvinec, Mariette
A circle C separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
Computing Largest Circles Separating Two Sets of Segments (2000)
Boissonnat, Jean-Daniel, Czyzowicz, Jurek, Devillers, Olivier, Urrutia, Jorge, Yvinec, Mariette
A circle C separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
Routing with guaranteed delivery in ad hoc wireless networks (1999)
Ivan Stojmenović, Jorge Urrutia
Abstract. We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less...
Routing with guaranteed delivery in ad hoc wireless networks (1999)
Prosenjit Bose, Pat Morin, Jorge Urrutia
We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some xed...
Routing with guaranteed delivery in ad hoc wireless networks (1999)
Prosenjit Bose, Pat Morin, Jorge Urrutia
We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some xed...
Routing with Guaranteed Delivery in ad hoc Wireless Networks (1999)
Prosenjit Bose, Pat Morin, Ivan Stojmenovic, Jorge Urrutia
We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some xed...
Compass Routing on Geometric Networks (1999)
Evangelos Kranakis, Harvinder Singh, Jorge Urrutia
this paper we study local routing algorithms on geometric networks. Formally speaking, suppose that we want to travel from a vertex s to a vertex t of a geometric network. A routing algorithm is...
The number of geometric bistellar neighbors of a triangulation (1999)
Francisco Santos, Jorge Urrutia
The theory of secondary and fiber polytopes implies that regular (also called convex or coherent) triangulations of configurations with n points in R
Jurek Czyzowicz, Ivan Stojmenovic, Jorge Urrutia
Let shape P be any simply-connected set in the plane, bounded by a Jordan curve, that is not a circular disk. We say that a set of points I on the boundary of P immobilize the shape if any rigid...
Routing with guaranteed delivery in ad hoc wireless networks (1999)
Ivan Stojmenović, Jorge Urrutia
Abstract. We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less...
Discrete Realizations of Contact and Intersection Graphs (Extended Abstract) (1998)
Czyzowicz, Jurek, Kranakis, Evangelos, Krizanc, Danny, Urrutia, Jorge
Known realizations of geometric representations of graphs, like contact, intersection etc., are "continuous", in the sense that the geometric objects are drawn in Euclidean space with real numbers as...
Efficient Regular Polygon Dissections (1998)
Evangelos Kranakis, Danny Krizanc, Jorge Urrutia
We study the minimum number g(m, n) (respectively, p(m, n)) of pieces needed to dissect a regular m-gon into a regular n-gon of the same area using glass-cuts (respectively, polygonal cuts). First we...
@ World Scientific Publighing Company (1997)
Immobilizing A Siiape, Jur. Ek Ctyzowicz, Fvan Stojmenovic, Jorge Urrutia, Compna Scieu:a Dryrbnett, Ottauo Aafurio Catfu
Communicated by G. T. Toussaint [,et shape P be any simply-connected set in the plane, bounded by a Jordan curve, that is not a circular disk. We say that a set of points f on tbe boundary of P...
Maximal Length Common Non-Intersecting Paths (1996)
Jurek Czyzowicz, Evangelos Kranakis, Danny Krizanc, Jorge Urrutia
Given a set P n of n points on the plane labeled with the integers f1; : : : ; ng, an increasing path of P n is a sequence of points i 1 ! : : : ! i k such that the polygonal path obtained by...
The Number Of Geometric Bistellar Neighbors Of A Triangulation (1996)
Jes'us A. Loera, Francisco Santos, Jorge Urrutia
The theory of secondary and fiber polytopes implies that regular (also called convex or coherent) triangulations of configurations with n points in R d have at least n \Gamma d \Gamma 1 geometric...
Computing Largest Circles Separating Two Sets of Segments (1995)
Boissonnat, Jean-Daniel, Czyzowicz, Jurek, Devillers, Olivier, Urrutia, Jorge, Yvinec, Mariette
A circle $C$ separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
Computing Largest Circles Separating Two Sets of Segments (1995)
Boissonnat, Jean-Daniel, Czyzowicz, Jurek, Devillers, Olivier, Urrutia, Jorge, Yvinec, Mariette
A circle $C$ separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
On the Number of Directions in Visibility Representations of Graphs (Extended Abstract) (1995)
Kranakis, Evangelos, Krizanc, Danny, Urrutia, Jorge
We consider visibility representations of graphs in which the vertices are presented by a collection O of non-overlapping convex regions on the plane. Two points x and y are visible if the...
Computing Largest Circles Separating Two Sets of Segments (1995)
Jorge Urrutia, Jean-daniel Boissonnat, Jean-daniel Boissonnat, Jurek Czyzowicz, Jurek Czyzowicz, Olivier Devillers, ...
A circle C separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
Stage-Graph Representations (1995)
Evangelos Kranakis, Danny Krizanc, Anil Maheshwari, Marc Noy, Jörg-Rüdiger Sack, Jorge Urrutia
We consider graph applications of the well-known paradigm "killing two birds with one stone". In the plane, this gives rise to a stage graph as follows: vertices are the points, and fu; vg...
On the Number of Directions in Visibility Representations of Graphs (Extended Abstract) (1995)
Evangelos Kranakis, Danny Krizanc, Jorge Urrutia
) Evangelos Kranakis 1 (kranakis@scs.carleton.ca) Danny Krizanc 1 (krizanc@scs.carleton.ca) Jorge Urrutia 2 (jorge@csi.uottawa.ca) 1 Carleton University, School of Computer Science, Ottawa, ON,...
Complexity of Boolean Routing (Extended Abstract) (1995)
Evangelos Kranakis, Danny Krizanc, Jorge Urrutia
) Evangelos Kranakis y (kranakis@scs.carleton.ca) Danny Krizanc y (krizanc@scs.carleton.ca) Jorge Urrutia zy (jorge@csi.uottawa.ca) Abstract We use the technique of Kolmogorov complexity to obtain...
Ray Shooting from Convex Ranges (1995)
Evangelos Kranakis, Danny Krizanc, Anil Maheshwari, Jörg-Rüdiger Sack, Jorge Urrutia
We consider geometric and graph-theoretic aspects of the well-known paradigm "killing two birds with one stone". Consider that we have a set X of n-points in space and a compact plane...
Planar Stage Graphs: Characterizations And Applications (1995)
Frank Bauernöppel, Evangelos Kranakis, Danny Krizanc, Anil Maheshwari, Jörg-Rüdiger Sack, Jorge Urrutia
We consider combinatorial and algorithmic aspects of the well-known paradigm "killing two birds with one stone". We define a stage graph as follows: vertices are the points from a planar...
An Improved Maximum Matching Algorithm in a Permutation Graph (1995)
Frank Bauernöppel, Evangelos Kranakis, Danny Krizanc, Anil Maheshwari, Jörg-Rüdiger Sack, Jorge Urrutia
Introduction We present an O(n log 2 n) time algorithm for computing a maximum matching in a permutation graph on n-vertices. Our results are based on the algorithm of [12] for a two processor...
Illumination of Polygons with Vertex Lights (1995)
Vladimir Estivill-Castro, Jorge Urrutia, Dianna Xu
We show that vertex floodlights of angle ß suffice to illuminate any polygon, and that no angle less than ß suffices for all polygons. 1 Introduction There has been recent interest in illumination...
Illumination with Orthogonal Floodlights (Extended Abstract) (1995)
James Abello, Vladimir Estivill-castro, Thomas Shermer, Jorge Urrutia
) James Abello 1 , Vladimir Estivill-Castro 2 , Thomas Shermer 3 , Jorge Urrutia 4 1 Department of Computer Science, Texas A & M University, College Station, Texas MS 3112, US....
Computing Largest Circles Separating Two Sets of Segments (1995)
Jorge Urrutia, Jean-daniel Boissonnat, Jean-daniel Boissonnat, Jurek Czyzowicz, Jurek Czyzowicz, ...
A circle C separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased...
Este trabajo investiga la hipotesis de Random Walk para cuatro mercados de capitales latinoamericanos.
Isomorphic Triangulations with Minimal Number of Steiner Points (Extended Abstract) (1994)
Evangelos Kranakis, Jorge Urrutia, Steiner Points
We present two algorithms for constructing isomorphic (i.e. adjacency preserving) triangulations of two simple n vertex polygons P, Q with k, l reflex vertices, respectively. The first algorithm...
VC-Dimensions For Graphs (1994)
Evangelos Kranakis, Danny Krizanc, Berthold Ruf, Jorge Urrutia, Gerhard J. Woeginger
We study set systems over the vertex set (or edge set) of some graph that are induced by special graph properties like clique, connectedness, path, star, tree, etc. We derive a variety of...
Jurek Czyzowicz, Eduardo Rivera-campo, Jorge Urrutia
A line L separates a set A from a collection S of plane sets if A is contained in one of the closed half-planes defined by L, while every set in S is contained in the complementary closed half-plane....
Prosenjit Bose, Leonidas Guibas, Anna Lubiw, Mark Overmars, Diane Souvaine, Jorge Urrutia
Given three angles summing to 2, given n points in the plane and a tripartition k1 + k2 + k3 = n, we can tripartition the plane into three wedges of the given angles so that the i-th wedge contains...
Prosenjit Bose, Leonidas Guibas, Anna Lubiw, Mark Overmars, Diane Souvaine, Jorge Urrutia
Given three angles summing to 2pi, given n points in the plane and a tripartition k 1 + k 2 + k 3 = n, we can tripartition the plane into three wedges of the given angles so that the i-th wedge...
Prosenjit Bose, Leonidas Guibas, Anna Lubiw, Mark Overmars, Diane Souvaine, Jorge Urrutia
Given three angles summing to 2ß, given n points in the plane and a tripartition k 1 + k 2 + k 3 = n, we can tripartition the plane into three wedges of the given angles so that the i-th wedge...
Light sources, obstructions and spherical orders, Discrete Mathematics 102 (1992)
Stephan Foldes, Stephan Foldes, Ivan Rival, Jorge Urrutia, Jorge Urrutia
by Abstract. Ordered sets are used as a computational model for motion planning in which figures on the plane may be moved along a ray emanating from a light source. The resulting obstructions give...
Binay Bhattacharya, Peter Egyed, Ivan Stojmenovic, Jorge Urrutia
Given a family of objecte in the plane, the line transversal problem is to compute a line that intersects every member of the family. In this paper we examine a variation of the line transversal...
Partial Orders and Euclidean Geometry (1987)
The study of simple families of geometric objects on the plane has always been of great interest in mathematics. Incidence relations among families of points, lines and circles on the Euclidean plane...
Sistemas de comunicación / J. Urrutia. (1975)
Contiene: La Comunicación; Teoría de la Comunicación; La Percepción de los Lenguajes; La Imagen y las Imágenes; El Lenguaje Natural Humano; La Literatura; La Escritura y las Escrituras; Teoría...