Recent Submissions

  • Chiellini Hamiltonian Liénard differential systems 

    Giné, Jaume; Llibre, Jaume; Valls, Claudia (Texas State University, 2019)
    We characterize the centers of the Chiellini Hamiltonian Li´enard second-order differential equations x 0 = y, y 0 = −f(x)y − g(x) where g(x) = f(x)(k − α(1 + α) R f(x)dx) with α, k ∈ R. Moreover we study the ...
  • Spectra and eigenspaces from regular partitions of Cayley (di)graphs of permutation groups 

    Dalfó, Cristina; Fiol, Miguel Angel (Elsevier, 2020)
    In this paper, we present a method to obtain regular (or equitable) partitions of Cayley (di)graphs (that is, graphs, digraphs, or mixed graphs) of permutation groups on n letters. We prove that every partition of the ...
  • Strongly formal Weierstrass non-integrability for polynomial differential systems in C2 

    Giné, Jaume; Llibre, Jaume (Bolyai Institute, University of SzegedHungarian Academy of Sciences, 2020)
    Recently a criterion has been given for determining the weakly formal Weierstrass non-integrability of polynomial differential systems in C2 . Here we extend this criterion for determining the strongly formal Weierstrass ...
  • Perturbed rank 2 Poisson systems and periodic orbits on Casimir invariant manifolds 

    García, I. A. (Isaac A.); Hernández Bermejo, Benito (Taylor & Francis, 2020-02-05)
    A class of n-dimensional Poisson systems reducible to an unperturbed harmonic oscillator shall be considered. In such case, perturbations leaving invariant a given symplectic leaf shall be investigated. Our purpose will ...
  • Cyclicity of Nilpotent Centers with Minimum Andreev Number 

    García, I. A. (Isaac A.) (Springer, 2019-10-07)
    We consider polynomial families of real planar vector fields for which the origin is a monodromic nilpotent singularity having minimum Andree's number. There the centers are characterized by the existence of a formal inverse ...
  • Idoneidad didáctica en educación infantil: matemáticas con robots Blue-Bot. 

    Ricart Aranda, María; Estrada Roca, M. Asunción; Margalef Martíl, María (Universidad de Córdoba, 2019)
    El objetivo de este trabajo es valorar la idoneidad didáctica de un proceso de enseñanza y aprendizaje de orientación espacial con el robot Blue-Bot. Primero, se contextualiza la experiencia innovadora implementada con ...
  • Flow resistance equations without explicit estimation of the resistance coefficient for coarse-grained rivers 

    López Alonso, Raúl; Barragán Fernández, Javier; Colomer, M. Àngels (Maria Àngels) (Elsevier, 2007)
    The uncertainty and subjectivity inherent in estimating the resistance coeffi-cient is one of the main sources of error in the application of flow resistance equations tonatural channels. Various studies have shown that ...
  • Reply to the comment by D.E. Rupp and G.M. Smart on "Flow resistance equations without explicit estimation of the resistance coefficient for coarse-grained rivers" 

    López Alonso, Raúl; Barragán Fernández, Javier; Colomer, M. Àngels (Maria Àngels) (Elsevier, 2007)
  • Parking Tickets for Privacy-Preserving Pay-by-Phone Parking 

    Borges, Ricard; Sebé Feixas, Francesc (Association for Computing Machinery (ACM), 2019)
    Traditionally, the payment required for parking in regulated areas has been made through parking meters. In the last years, several applications which allow to perform these payments using a mobile device have appeared. In ...
  • The spectra of lifted digraphs 

    Dalfó, Cristina; Fiol, Miguel Angel; Sirán, Jozef (Springer, 2019-01-02)
    We present a method to derive the complete spectrum of the lift Γα of a base digraph Γ , with voltage assignment α on a (finite) group G. The method is based on assigning to Γ a quotient-like matrix whose entries are ...
  • The spectral excess theorem for graphs with few eigenvalues whose distance- 2 or distance-1-or-2 graph is strongly regular 

    Dalfó, Cristina; Fiol, Miguel Angel; Koolen, Jack (Taylor & Francis, 2018-07-13)
    We study regular graphs whose distance-2 graph or distance-1-or-2 graph is strongly regular. We provide a characterization of such graphs Γ (among regular graphs with few distinct eigenvalues) in terms of the spectrum and ...
  • Spectra and eigenspaces of arbitrary lifts of graphs 

    Dalfó, Cristina; Fiol, Miguel Angel; Pavlíková, Sona; Sirán, Josef (Faculty of Mathematics, Physics and Informatics, Comenius University, 2019)
    We describe, in a very explicit way, a method for determining the spec-tra and bases of all the corresponding eigenspaces of arbitrary lifts of graphs (regularor not).
  • El mètode de les línies per a la resolució aproximada d'equacions en derivades parcials 

    Dalfó, Cristina; Fiol, Miguel Angel (Societat Catalana de Matemàtiques, Institut d’Estudis Catalans, 2019)
    En aquest treball es descriu un mètode numèric semidiscret per a la resolució d'un tipus d'equacions en derivades parcials. És conegut com el mètode de les línies (MOL, per les sigles en anglès), i es basa en la discretització ...
  • The diameter of cyclic Kautz digraphs 

    Böhmová, Katerina; Dalfó, Cristina; Huemer, Clemens (Faculty of Sciences and Mathematics, University of Nis, Serbia, 2017)
    We present a new kind of digraphs, called cyclic Kautz digraphs CK(d, ɭ), which are subdigraphs of the well-known Kautz digraphs K(d,ɭ). The latter have the smallest diameter among all digraphs with their number of ...
  • On the Randić index of graphs 

    Dalfó, Cristina (Elsevier, 2018-09-11)
    For a given graph G = (V, E), the degree mean rate of an edge uv ∈ E is a half of the quotient between the geometric and arithmetic means of its end-vertex degrees d(u) and d(v). In this note, we derive tight bounds for ...
  • A note on a new general family of deterministic hierarchical networks 

    Dalfó, Cristina; Fiol, Miguel Angel (World Scientific Publishing, 2019)
    It is known that many networks modeling real-life complex systems are small-word (large local clustering and small diameter) and scale-free (power law of the degree distribution), and very often they are also hierarchical. ...
  • Magic coverings and the Kronecker product 

    López Masip, Susana-Clara; Muntaner Batle, F. A.; Rius Font, Miquel (2014)
    In this paper we study a relationship existing among (super) magic coverings and the well known Kronecker product of matrices. We also introduce the concept of Zn-property for digraphs in order to study this relation ...
  • On super edge-magic decomposable graphs 

    López Masip, Susana-Clara; Muntaner Batle, F. A.; Rius Font, Miquel (Springer, 2012)
    Let G be any graph and let {Hi}i∈I be a family of graphs such that E(Hi) ∩ E(Hj ) = ∅ when i 6= j, ∪i∈IE(Hi) = E(G) and E(Hi) 6= ∅ for all i ∈ I. In this paper we introduce the concept of {Hi}i∈I -super edge-magic decomposable ...
  • The power of digraph products applied to labelings 

    Ichishima, R.; López Masip, Susana-Clara; Muntaner Batle, F. A.; Rius Font, Miquel (Elsevier, 2012)
    The ⊗h-product was introduced in 2008 by Figueroa-Centeno et al. as a way to construct new families of (super) edge-magic graphs and to prove that some of those families admit an exponential number of (super) edge-magic ...
  • Bi-magic and other generalizations of super edge-magic labelings 

    López Masip, Susana-Clara; Muntaner Batle, F. A.; Rius Font, Miquel (Cambridge University Press, 2011)
    In this paper, we use the product ⊗h in order to study super edge-magic labelings, bi-magic labelings and optimal k-equitable labelings. We establish, with the help of the product ⊗h, new relations between super edge-magic ...

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