Ara es mostren els items 1-20 de 20

    • Algebraic phylogenetic reconstruction based on proteins and its application to Persea americana 

      Pérez Gonzalo, Raül (Universitat Politècnica de Catalunya, 2018-09)
      Treball Final de Grau
      Accés obert
      Phylogenetic reconstruction methods attempt to infer the evolutionary relationships among a group of species. Apart from classical reconstruction methods, new methods have been developed based on algebraic relationships ...
    • Analysis of satellite constellations for the continuous coverage of ground regions 

      Dai, Guangming; Chen, Xiaoyu; Wang, Maocai; Fernández Aréizaga, Elena; Nguyen, Tuan Nam; Reinelt, Gerhard (2017-11-01)
      Article
      Accés obert
      This paper studies the problem of analyzing multisatellite constellations with respect to their coverage capacity of areas on Earth’s surface. The geometric configuration of constellation projection points on Earth’s surface ...
    • Cell-paths 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)
      Text en actes de congrés
      Accés obert
      We 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 ...
    • Computing optimal shortcuts for networks 

      Garijo Royo, Delia; Marquez Pérez, Alberto; Rodríguez, Natalia; Silveira, Rodrigo Ignacio (Elsevier, 2019-11-16)
      Article
      Accés obert
      We study augmenting a plane Euclidean network with a segment, called a shortcut, to minimize the largest distance between any two points along the edges of the resulting network. Problems of this type have received ...
    • Continuous mean distance of a weighted graph 

      Garijo Royo, Delia; Marquez Pérez, Alberto; Silveira, Rodrigo Ignacio (2022)
      Text en actes de congrés
      Accés obert
      We study the concept of the continuous mean distance of a weighted graph. For connected unweighted graphs, the mean distance can be defined as the arithmetic mean of the distances between all pairs of vertices. This parameter ...
    • Effective computation of base points of two-dimensional ideals 

      Blanco Fernández, Guillem (Universitat Politècnica de Catalunya, 2015-10)
      Projecte Final de Màster Oficial
      Accés obert
      This works focus on computational aspects of the theory of singularities of plane algebraic curves. We show how to use the Puiseux factorization of a curve, computed through the Newton-Puiseux algorithm, to study the ...
    • Geomasking through perturbation, or counting points in circles 

      Löffler, Maarten; Luo, Jun; Silveira, Rodrigo Ignacio (2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Motivated by a technique in privacy protection, in which n points are randomly perturbed by at most a distance r, we study the following problem: Given n points and m circles in the plane, what is the maximum r such that ...
    • Graphs attaining the upper bound on the isolation number 

      Lemanska, Magdalena; Mora Giné, Mercè; Souto Salorio, María josé (Universidad de Cádiz, 2023)
      Text en actes de congrés
      Accés obert
      A set D of vertices of a graph is isolating if the set of vertices not belonging to D or not having a neighbour in D is independent. The isolation number of a graph G, denoted by ¿(G), is the minimum cardinality of an ...
    • Invariants, una aproximació a la filogenètica des de l'àlgebra 

      Fernández Sánchez, Jesús (2010)
      Article
      Accés obert
      En els darrers anys, una nova aproximació a la reconstrucció filogenètica basada en tècniques provinents de l’àlgebra s’ha estat consolidant. Fixat un model evolutiu per a un conjunt donat d’espècies, els invariants són ...
    • On approximating shortest paths in weighted triangular tessellations 

      Bose, Prosenjit; Esteban Pascual, Guillermo; Orden Martin, David; Silveira, Rodrigo Ignacio (Springer, 2022)
      Text en actes de congrés
      Accés obert
      We study the quality of weighted shortest paths when a continuous 2-dimensional space is discretized by a weighted triangular tessellation. In order to evaluate how well the tessellation approximates the 2-dimensional ...
    • On the Oß-hull of a planar point set 

      Alegría Galicia, Carlos; Orden, David; Seara Ojea, Carlos; Urrutia Galicia, Jorge (2018-03-01)
      Article
      Accés obert
      We study the Oß-hull of a planar point set, a generalization of the Orthogonal Convex Hull where the coordinate axes form an angle ß. Given a set P of n points in the plane, we show how to maintain the Oß-hull of P while ...
    • Rank conditions on phylogenetic networks 

      Casanellas Rius, Marta; Fernández Sánchez, Jesús (Birkhäuser, 2021)
      Capítol de llibre
      Accés restringit per política de l'editorial
      Less rigid than phylogenetic trees, phylogenetic networks allow the description of a wider range of evolutionary events. In this note, we explain how to extend the rank invariants from phylogenetic trees to phylogenetic ...
    • Results on the Spinc-genus 

      Zampa, Sarah Juliet (Universitat Politècnica de Catalunya, 2020-10)
      Projecte Final de Màster Oficial
      Accés restringit per decisió de l'autor
      In this work, we study manifolds with a Spin-c-structure, and give results on a Spin-c-genus derived from the Witten genus. We also implement codes in order to compute this genus on usual manifolds.
    • Shortest paths in portalgons 

      Löffler, M.; Silveira, Rodrigo Ignacio; Staals, Frank (2021)
      Text en actes de congrés
      Accés restringit per política de l'editorial
    • Spanning ratio of shortest paths in weighted square tessellations 

      Bose, Prosenjit; Esteban Pascual, Guillermo; Orden Martin, David; Silveira, Rodrigo Ignacio (2022)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Continuous 2-dimensional space is often discretized by considering a grid of weighted square cells. In this work we study how well a weighted tessellation approximates the space, with respect to shortest paths. In particular, ...
    • Stabbers of line segments in the plane 

      Claverol Aguas, Mercè; Garijo, Delia; Grima, Clara; Márquez, Alberto; Seara Ojea, Carlos (2011-07)
      Article
      Accés obert
      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 ...
    • Tangential varieties of Segre–Veronese surfaces are never defective 

      Catalisano, Maria Virginia; Oneto, Alessandro (Springer, 2020-02-01)
      Article
      Accés obert
      We compute the dimensions of all the secant varieties to the tangential varieties of all Segre–Veronese surfaces. We exploit the typical approach of computing the Hilbert function of special 0-dimensional schemes on ...
    • Terrain prickliness: theoretical grounds for low complexity viewsheds 

      Acharyya, Ankush; Jallu, Ramesh; Löffler, M.; Meijer, Geert; Saumell Mendiola, Maria; Silveira, Rodrigo Ignacio; Staals, Frank; Tiwary, Hans Raj (2021)
      Text en actes de congrés
      Accés restringit per política de l'editorial
    • The conjugacy problem in extensions of Thompson's group F 

      Burillo Puig, José; Matucci, Francesco; Ventura Capell, Enric (2016-10-01)
      Article
      Accés obert
      We solve the twisted conjugacy problem on Thompson’s group F. We also exhibit orbit undecidable subgroups of Aut(F), and give a proof that Aut(F) and Aut+(F) are orbit decidable provided a certain conjecture on Thompson’s ...
    • The Kernel Matrix Diffie-Hellman Assumption 

      Morillo Bosch, M. Paz; Ràfols Salvador, Carla; Villar Santos, Jorge Luis (2016-12)
      Article
      Accés obert
      We put forward a new family of computational assumptions, the Kernel Matrix Diffie-Hellman Assumption. Given some matrix A sampled from some distribution D, the kernel assumption says that it is hard to find “in the exponent” ...