Enviaments recents

  • A new labeling construction from the -product 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni; Prabu, M. (2017-08-01)
    Article
    Accés restringit per política de l'editorial
    The ¿h-product that is referred in the title was introduced in 2008 as a generalization of the Kronecker product of digraphs. Many relations among labelings have been obtained since then, always using as a second factor a ...
  • The number and degree distribution of spanning trees in the Tower of Hanoi graph 

    Zhang, Zhongzhi; Wu, Shunqi; Li, Mingyun; Comellas Padró, Francesc de Paula (2016-01-04)
    Article
    Accés restringit per política de l'editorial
    The number of spanning trees of a graph is an important invariant related to topological and dynamic properties of the graph, such as its reliability, communication aspects, synchronization, and so on. However, the practical ...
  • Iterated line digraphs are asymptotically dense 

    Dalfó Simó, Cristina (Elsevier, 2017)
    Article
    Accés obert
    We show that the line digraph technique, when iterated, provides dense digraphs, that is, with asymptotically large order for a given diameter (or with small diameter for a given order). This is a well- known result for ...
  • The normalized Laplacian spectrum of subdivisions of a graph 

    Xie, Pinchen; Zhang, Zhongzhi; Comellas Padró, Francesc de Paula (2016-08-05)
    Article
    Accés restringit per política de l'editorial
    Determining and analyzing the spectra of graphs is an important and exciting research topic in mathematics science and theoretical computer science. The eigenvalues of the normalized Laplacian of a graph provide information ...
  • On perfect and quasiperfect dominations in graphs 

    Hernando Martín, María del Carmen; Mora Giné, Mercè; Pelayo Melero, Ignacio Manuel; Cáceres, José; Puertas, M. Luz (2017-02-27)
    Article
    Accés obert
    A subset S ¿ V in a graph G = ( V , E ) is a k -quasiperfect dominating set (for k = 1) if every vertex not in S is adjacent to at least one and at most k vertices in S . The cardinality of a minimum k -quasiperfect ...
  • Perfect (super) Edge-Magic Crowns 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni; Prabu, M. (2017-01-06)
    Article
    Accés restringit per política de l'editorial
    A graph G is called edge-magic if there is a bijective function f from the set of vertices and edges to the set {1,2,…,|V(G)|+|E(G)|} such that the sum f(x)+f(xy)+f(y) for any xy in E(G) is constant. Such a function is ...
  • General properties of c-circulant digraphs 

    Mora Giné, Mercè; Serra Albó, Oriol; Fiol Mora, Miquel Àngel (1988)
    Article
    Accés obert
    A digraph is said to be a c-circulant if its adjacency matrix is c-circulant. This paper deals with general properties of this family of digraphs, as isomorphisms, regularity, strong connectivity, diameter and the relation ...
  • Rainbow eulerian multidigraphs and the product of cycles 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni (2016-01-01)
    Article
    Accés obert
    An arc colored eulerian multidigraph with l colors is rainbow eulerian if there is an eulerian circuit in which a sequence of l colors repeats. The digraph product that refers the title was introduced by Figueroa-Centeno ...
  • Distance labelings: a generalization of Langford sequences 

    López Masip, Susana Clara; Muntaner Batle, Francesc Antoni (2016-01-05)
    Article
    Accés obert
    A Langford sequence of order m and defect d can be identified with a labeling of the vertices of a path of order 2m in which each labeled from d up to d + m - 1 appears twice and in which the vertices that have been label ...
  • Commensurations and metric properties of Houghton's groups 

    Burillo Puig, José; Cleary, Sean; Martino, Armando; Röver, Claas E. (2016-12-01)
    Article
    Accés obert
    We describe the automorphism groups and the abstract commensurators of Houghton’s groups. Then we give sharp estimates for the word metric of these groups and deduce that the commensurators embed into the corresponding ...

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