15 citations · 38 across the 11 of their papers we have counts for
13 papers
Conflict-Free Coloring of Planar Graphs
Zachary Abel, Victor Alvarez, Aman Gour +5
A conflict-free k-coloring of a graph assigns one of k different colors to some of the vertices such that, for every vertex v, there is a color that is assigned to exactly one vert…
Gröbner bases and cocyclic Hadamard matrices
V. Álvarez, J. A. Armario, R. M. Falcón +2
Hadamard ideals were introduced in 2006 as a set of nonlinear polynomial equations whose zeros are uniquely related to Hadamard matrices with one or two circulant cores of a given…
Equivalences of -cocyclic Hadamard matrices
V. Alvarez, F. Gudiel, M. B. Guemes +2
One of the most promising structural approaches to resolving the Hadamard Conjecture uses the family of cocyclic matrices over . Two types of…
Main Memory Adaptive Indexing for Multi-core Systems
Victor Alvarez, Felix Martin Schuhknecht, Jens Dittrich +1
Adaptive indexing is a concept that considers index creation in databases as a by-product of query processing; as opposed to traditional full index creation where the indexing effo…
Counting Triangulations and other Crossing-Free Structures Approximately
Victor Alvarez, Karl Bringmann, Saurabh Ray +1
We consider the problem of counting straight-edge triangulations of a given set of points in the plane. Until very recently it was not known whether the exact number of tri…
Counting Triangulations and other Crossing-free Structures via Onion Layers
Victor Alvarez, Karl Bringmann, Radu Curticapean +1
Let be a set of points in the plane. A crossing-free structure on is a plane graph with vertex set . Examples of crossing-free structures include triangulations of $…
A Simple Sweep Line Algorithm for Counting Triangulations and Pseudo-triangulations
Victor Alvarez, Karl Bringmann, Saurabh Ray
Let be a set of points. In this paper we show two new algorithms, one to compute the number of triangulations of , and one to compute the number of…
GA based robust blind digital watermarking
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +4
A genetic algorithm based robust blind digital watermarking scheme is presented. Starting from a binary image (the original watermark), a genetic algorithm is performed searching f…
Embedding cocyclic D-optimal designs in cocyclic Hadamard matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +1
In this paper a method for embedding cocyclic submatrices with ``large'' determinants of orders 2t in certain cocyclic Hadamard matrices of orders 4t is described (t an odd integer…
Searching for partial Hadamard matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +4
Three algorithms looking for pretty large partial Hadamard matrices are described. Here "large" means that hopefully about a third of a Hadamard matrix (which is the best asymptoti…
The cohomological reduction method for computing n-dimensional cocyclic matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +1
Provided that a cohomological model for is known, we describe a method for constructing a basis for -cocycles over , from which the whole set of -dimensional -cocyc…
Some new operations on Zt x Z2,2-cocyclic Hadamard matrices
Victor Alvarez, Felix Gudiel, Maria Belen Guemes
Following the ideas of [AGG11] about Zt x Z2,2-cocyclic Hadamard matrices, we introduce the notion of diagram, which visually represents any set of coboundaries. Diagrams are a ver…
Computing Small 1-Homological Models for Commutative Differential Graded Algebras
Victor Alvarez, Jose Andres Armario, Maria Dolores Frau +4
We use homological perturbation machinery specific for the algebra category [P. Real. Homological Perturbation Theory and Associativity. Homology, Homotopy and Applications vol. 2,…