Now showing items 93-112 of 314

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      Derivation of a bilayer model for shallow water equations with viscosity. Numerical validation  [Article]

      Narbona Reina, Gladys; Zabsonré, J.D.; Fernández Nieto, Enrique Domingo; Bresch, Didier (Tech Science Press, 2009)
      In this work we present a new two-dimensional bilayer Shallow-Water model including viscosity and friction effects on the bottom and interface level. It is obtained following [[6]] from an asymptotic analysis of non-dimensional ...
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      Designing a new software tool for digital imagery based on P systems  [Article]

      Díaz Pernil, Daniel; Gutiérrez Naranjo, Miguel Ángel; Molina Abril, Helena; Real Jurado, Pedro (2012)
      In this paper we present a new software tool for dealing with the problem of segmentation in Digital Imagery. The implementation is inspired in the design of a tissue-like P system which solves the problem in constant time ...
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      Designing evacuation routes with GeoGebra  [Article]

      Falcón Ganfornina, Raúl Manuel; Moreno, Ángela; Ríos Collantes de Terán, Ricardo (GeoGebra Institute of Timisoara, 2015)
      We expose in this paper how the command ShortestDistance can be used in GeoGebra to design evacuation routes in buildings in a dynamic and interactive way. For those cases in which a legal regulation or procedure compels ...
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      Determinants of (–1,1)-matrices of the skew-symmetric type: a cocyclic approach  [Article]

      Álvarez Solano, Víctor; Armario Sampalo, José Andrés; Frau García, María Dolores; Gudiel Rodríguez, Félix (Walter de Gruyter GmbH, 2015)
      An n by n skew-symmetric type (−1, 1)-matrix K = [ki,j ] has 1’s on the main diagonal and ±1’s elsewhere with ki,j = −kj,i. The largest possible determinant of such a matrix K is an interesting problem. The literature ...
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      Diagonal flips in outer-triangulations on closed surfaces  [Article]

      Cortés Parejo, María del Carmen; Grima Ruiz, Clara Isabel; Márquez Pérez, Alberto; Nakamoto, Atsuhiro (2002)
      We show that any two outer-triangulations on the same closed surface can be transformed into each other by a sequence of diagonal flips, up to isotopy, if they have a sufficiently large and equal number of vertices.
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      Diagonal flips in outer-triangulations on closed surfaces  [Article]

      Cortés Parejo, María del Carmen; Grima Ruiz, Clara Isabel; Márquez Pérez, Alberto; Nakamoto, Atsuhiro (2002)
      We show that any two outer-triangulations on the same closed surface can be transformed into each other by a sequence of diagonal flips, up to isotopy, if they have a sufficiently large and equal number of vertices.
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      Dilation-free graphs in the l1 metric  [Article]

      Cáceres González, José; Grima Ruiz, Clara Isabel; Márquez Pérez, Alberto; Moreno González, Auxiliadora (2007)
      The dilation-free graph of a planar point set S is a graph that spans S in such a way that the distance between two points in the graph is no longer than their planar distance. Metrically speaking, those graphs are equivalent ...
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      Distinguishing graphs by their left and right homomorphism profiles  [Article]

      Garijo Royo, Delia; Goodall, Andrew; Nešetřil, Jaroslav (Elsevier, 2011)
      We introduce a new property of graphs called ‘q-state Potts unique-ness’ and relate it to chromatic and Tutte uniqueness, and also to ‘chromatic–flow uniqueness’, recently studied by Duan, Wu and Yu. We establish for ...
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      Duality of measures of non-A-compactness  [Article]

      Juan Manuel Delgado Sánchez; Cándido Piñeiro Gómez (Polskiej Akademii Nauk, Instytut Matematyczny, 2015)
      Let A be a Banach operator ideal. Based on the notion of A-compactness in a Banach space due to Carl and Stephani, we deal with the notion of measure of non-A-compactness of an operator. We consider a map χA (respectively, ...
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      Efficient GPU implementation of a two waves TVD-WAF method for the two-dimensional one layer Shallow Water system on structured meshes.  [Article]

      Asunción, M. de la; Castro Díaz, Manuel Jesús; Fernández Nieto, Enrique Domingo; Mantas, José Miguel; Ortega Acosta, Sergio; González Vida, José Manuel (Elsevier, 2013)
      The numerical solutions of shallow water equations are useful for applications related to geophysical flows that usually take place in large computational domains and could require real time calculation. Therefore, parallel ...
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      Efficient numerical schemes for viscoplastic avalanches. Part 1: The 1D case.  [Article]

      Fernández Nieto, Enrique Domingo; Gallardo, José M.; Vigneaux, Paul (Elsevier, 2014)
      This paper deals with the numerical resolution of a shallow water viscoplastic flow model. Viscoplastic materials are characterized by the existence of a yield stress: below a certain critical threshold in the imposed ...
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      Efficient numerical schemes for viscoplastic avalanches. Part 2: the 2D case  [Article]

      Fernández Nieto, Enrique Domingo; Gallardo, José M.; Vigneaux, Paul (Elsevier, 2018)
      This paper deals with the numerical resolution of a shallow water viscoplastic flow model. Viscoplastic materials are characterized by the existence of a yield stress: below a certain critical threshold in the imposed ...
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      Efficiently Storing Well-Composed Polyhedral Complexes Computed Over 3D Binary Images  [Article]

      González Díaz, Rocío; Jiménez Rodríguez, María José; Medrano Garfia, Belén (Springer, 2017)
      A 3D binary image I can be naturally represented by a combinatorial-algebraic structure called cubical complex and denoted by Q(I ), whose basic building blocks are vertices, edges, square faces and cubes. In Gonzalez-Diaz et ...
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      Embedding a graph in the grid of a surface with the minimum number of bends is NP-hard  [Article]

      Garrido Vizuete, María de los Angeles; Márquez Pérez, Alberto (1997)
      This paper is devoted to the study of graph embeddings in the grid of non-planar surfaces. We provide an adequate model for those embeddings and we study the complexity of minimizing the number of bends. In particular, we ...
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      Embedding cocylic D-optimal designs in cocylic Hadamard matrices  [Article]

      Álvarez Solano, Víctor; Armario Sampalo, José Andrés; Frau García, María Dolores; Gudiel Rodríguez, Félix (International Linear Algebra Society, 2012)
      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). If these determinants attain the largest possible ...
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      Enumeration and classification of self-orthogonal partial Latin rectangles by using the polynomial method  [Article]

      Falcón Ganfornina, Raúl Manuel (Elsevier, 2015)
      The current paper deals with the enumeration and classification of the set SORr,n of self-orthogonal r × r partial Latin rectangles based on n symbols. These combinatorial objects are identified with the independent sets ...
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      Equations, inequations and inequalities characterizing the configurations of two real projective conics  [Article]

      Briand, Emmanuel (Springer, 2007)
      Couples of proper, non-empty real projective conics can be classified modulo rigid isotopy and ambient isotopy. We characterize the classes by equations, inequations and inequalities in the coefficients of the quadratic ...
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      Equivalences of Zt×Z22-cocyclic Hadamard matrices  [Article]

      Álvarez Solano, Víctor; Gudiel Rodríguez, Félix; Güemes Alzaga, María Belén; Horadam, K.J.; Rao, A. (Cornell University, 2015)
      One of the most promising structural approaches to resolving the Hadamard Conjecture uses the family of cocyclic matrices over Zt × Z2 2. Two types of equivalence relations for classifying cocyclic matrices over Zt × ...
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      Error estimates of a linear decoupled Euler–FEM scheme for a mass diffusion model  [Article]

      Guillén González, Francisco Manuel; Gutiérrez Santacreu, Juan Vicente (Springer, 2011)
      We present error estimates of a linear fully discrete scheme for a threedimensional mass diffusion model for incompressible fluids (also called Kazhikhov– Smagulov model). All unknowns of the model (velocity, pressure ...
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      ¿Es posible geogebrizar una olimpiada matemática?  [Article]

      Barrena Algara, Eva; Falcón Ganfornina, Raúl Manuel; Ramírez Campos, Rosana; Rios Collantes de Terán, Ricardo (Sociedad Andaluza de Educación Matemática Thales, 2010)
      En la presente comunicación se pretende abordar la resolución dinámica de algunos de los problemas geométricos que han aparecido en las diferentes fases desarrolladas en las veinticinco ediciones de la Olimpiada Matemática ...