BIRD, BCAM's Institutional Repository Data: Recent submissions
Now showing items 120 of 591

The MWright function as a generalization of the Gaussian density for fractional diffusion processes
(Fractional Calculus and Applied Analysis, 20131231)The leading role of a special function of the Wrighttype, referred to as MWright or Mainardi function, within a parametric class of selfsimilar stochastic processes with stationary increments, is surveyed. This class ... 
Twoparticle anomalous diffusion: Probability density functions and selfsimilar stochastic processes
(Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 20131231)Twoparticle dispersion is investigated in the context of anomalous diffusion. Two different modeling approaches related to time subordination are considered and unified in the framework of selfsimilar stochastic processes. ... 
Sensitivity study of boreholetosurface and crosswell electromagnetic measurements acquired with energized steel casing to water displacement in hydrocarbonbearing layers
(Geophysics, 20081231)We study the theoretical response of electromagnetically energized steel casing in the presence of subsurface variations of electrical resistivity. Casing is energized with a finitesize solenoid antenna located along the ... 
Energynormbased and goaloriented automatic hp adaptivity for electromagnetics: Application to waveguide Discontinuities
(IEEE Transactions on Microwave Theory and Techniques, 20081231)The finiteelement method (FEM) enables the use of adapted meshes. The simultaneous combination of h (local variations in element size) and p (local variations in the polynomial order of approximation) refinements, i.e., ... 
Rigorous numerics in floquet theory: Computing stable and unstable bundles of periodic orbits
(SIAM Journal on Applied Dynamical Systems, 20131231)In this paper, a rigorous method to compute Floquet normal forms of fundamental matrix solutions of nonautonomous linear differential equations with periodic coefficients is introduced. The Floquet normal form of a fundamental ... 
Discrete nonnegativity for nonlinear cooperative parabolic PDE systems with nonmonotone coupling
(Mathematics and Computers in Simulation, 20131231)Discrete nonnegativity principles are established for finite element approximations of nonlinear parabolic PDE systems with mixed boundary conditions. Previous results of the authors are extended such that diagonal dominance ... 
Singular dynamics under a weak potential on a sphere
(Nonlinear Differential Equations and Applications, 20131231)We give a detailed analytical description of the global dynamics of a point mass moving on a sphere under the action of a logarithmic potential. We perform a McGeheetype blowup in order to cope with the singularity of ... 
An IMEX scheme combined with Richardson extrapolation methods for some reactiondiffusion equations
(Idojaras, 20131231)An implicitexplicit (IMEX) method is combined with some socalled Richardson extrapolation (RiEx) methods for the numerical solution of reactiondiffusion equations with pure Neumann boundary conditions. The results are ... 
Editors' preface for the topical issue "Numerical Methods for LargeScale Scientific Computing, II"
(Central European Journal of Mathematics, 20131231)[No abstract available] 
Editors' preface for the topical issue "Numerical Methods for LargeScale Scientific Computing, I"
(Central European Journal of Mathematics, 20131231)[No abstract available] 
Simulation of DC duallaterolog measurements in complex formations: A Fourierseries approach with nonorthogonal coordinates and selfadapting finite elements
(Geophysics, 20091231)Dual laterolog (DLL) makes use of a galvanic conduction principle to focus electrical currents into rock formations, thereby minimizing shoulder and borehole effects in the measurement of formation resistivity. The tool ... 
Performance of a multifrontal parallel direct solver for hpfinite element method
(Proceedings of the IASTED International Conference on Advances in Computer Science and Engineering, ACSE 2009, 20091231)In this paper we present the performance of our parallel multifrontal direct solver when applied to solve linear systems of equations resulting from discretizations of a hp Finite Element Method (hpFEM). The hpFEM ... 
Simulation of marine controlled source electromagnetic measurements using a parallel fourier hpfinite element method
(Computational Geosciences, 20111231)We introduce a new numerical method to simulate geophysical marine controlled source electromagnetic (CSEM) measurements for the case of 2D structures and finite 3D sources of electromagnetic (EM) excitation. The method ... 
Rigorous numerics for symmetric connecting orbits: Even homoclinics of the GrayScott equation
(SIAM Journal on Mathematical Analysis, 20111231)In this paper we propose a rigorous numerical technique for the computation of symmetric connecting orbits for ordinary differential equations. The idea is to solve a projected boundary value problem (BVP) in a function ... 
On modifications of continuous and discrete maximum principles for reactiondiffusion problems
(Advances in Applied Mathematics and Mechanics, 20111231)In this work, we present and discuss some modifications, in the form of twosided estimation (and also for arbitrary source functions instead of usual signconditions), of continuous and discrete maximum principles for the ... 
Nonobtuse local tetrahedral refinements towards a polygonal face/interface
(Applied Mathematics Letters, 20111231)In this note we show how to generate and conformally refine nonobtuse tetrahedral meshes locally in the neighbourhood of a polygonal face or a polygonal interior interface of a threedimensional domain. The technique ... 
Generalization of the Zlámal condition for simplicial finite elements in ℝ d
(Applications of Mathematics, 20111231)The famous Zlámal's minimum angle condition has been widely used for construction of a regular family of triangulations (containing nondegenerating triangles) as well as in convergence proofs for the finite element method ... 
On the regularization of the collision solutions of the onecenter problem with weak forces
(Discrete and Continuous Dynamical Systems, 20111231)We study the possible regularization of collision solutions for one centre problems with a weak singularity. In the case of logarithmic singularities, we consider the method of regularization via smoothing of the potential. ... 
Exponential decay of highorder spurious prolate spheroidal modes induced by a local approximate dtn exterior boundary condition
(Progress In Electromagnetics Research B, 20121231)We investigate analytically the asymptotic behavior of highorder spurious prolate spheroidal modes induced by a secondorder local approximate DtN absorbing boundary condition (DtN2) when employed for solving highfrequency ... 
The maximum angle condition is not necessary for convergence of the finite element method
(Numerische Mathematik, 20121231)We show that the famous maximum angle condition in the finite element analysis is not necessary to achieve the optimal convergence rate when simplicial finite elements are used to solve elliptic problems. This condition ...