Now showing items 13-24 of 27

    • Betweenness-selfcentric graphs 

      Gago Álvarez, Silvia; Hurajová, Jana; Madaras, Tomas (2012-04-11)
      Research report
      Open Access
      The betweenness centrality of a vertex of a graph is the portion of shortest paths between all pairs of vertices passing through that vertex. In this paper, we study properties and constructions of graphs whose vertices ...
    • Smoothing of yield surfaces and a reformulation of multi-surface plasticity 

      Gesto Beiroa, José Manuel; Gens Solé, Antonio; Vaunat, Jean (Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE), 2011)
      Conference report
      Open Access
      In this work we describe a procedure for the smoothing of non-regular yield surfaces and plastic potential functions. We also present several application examples corresponding to different well-known cases. Moreover, we ...
    • Jacobi matrices and boundary value problems in distance-regular graphs 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gago Álvarez, Silvia (2012-01-25)
      Research report
      Open Access
      In this work we analyze regular boundary value problems on a distance-regular graph associated with SchrÄodinger operators. These problems include the cases in which the boundary has two or one vertices. Moreover, we obtain ...
    • M-Matrix Inverse problem for distance-regular graphs 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Mitjana Riera, Margarida (2010)
      Conference lecture
      Open Access
    • Kirchhoff indexes of a network 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel; Mitjana Riera, Margarida (Elsevier, 2010-04-15)
      Article
      Restricted access - publisher's policy
      In this work we define the effective resistance between any pair of vertices with respect to a value λ ≥ 0 and a weight ω on the vertex set. This allows us to consider a generalization of the Kirchhoff Index of a finite ...
    • A formula for the Kirchhoff index 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2007-09-30)
      Article
      Open Access
      We show here that the Kirchhoff index of a network is the average of the Wiener capacities of its vertices. Moreover, we obtain a closed-form formula for the effective resistance between any pair of vertices when the ...
    • Application of the forces' method in dynamic systems 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2007-10-11)
      Article
      Open Access
      We present here some applications of the Forces's method in dynamic systems. In particular, we consider the problem of the approximation of the trajectories of a conservative system of point masses by means of the minimization ...
    • Computational cost of the Fekete problem 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2007-10-11)
      Article
      Open Access
      We present here strong numerical and statistical evidence of the fact that the Smale's 7th problem can be answered affirmatively. In particular, we show that a local minimum for the logarithmic potential energy in the ...
    • Characterization of symmetric M-matrices as resistive inverses 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2007-01-25)
      Article
      Open Access
      We aim here at characterizing those nonnegative matrices whose inverse is an irreducible Stieltjes matrix. Specifically, we prove that any irreducible Stieltjes matrix is a resistive inverse. To do that we consider the ...
    • Potential Theory for boundary value problems on finite networks 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2006-07)
      Article
      Open Access
      We aim here at analyzing self-adjoint boundary value problems on finite networks associated with positive semi-definite Schrödinger operators. In addition, we study the existence and uniqueness of solutions and its ...
    • Bounds on the first non-null eigenvalue for self-adjoint boundary value problems on networks 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2006-09)
      Article
      Open Access
      We aim here at obtaining bounds on the first non-null eigenvalue for self-adjoint boundary value problems on a weighted network by means of equilibrium measures, that includes the study of Dirichlet, Neumann and Mixed ...
    • Regular boundary value problems on a path throughout Chebyshev Polynomials 

      Bendito Pérez, Enrique; Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gesto Beiroa, José Manuel (2006-08)
      Article
      Open Access
      In this work we study the different types of regular boundary value problems on a path associated with the Schrödinger operator. In particular, we obtain the Green function for each problem and we emphasize the case of ...