Now showing items 21-40 of 610

• #### Enhancing sampling in atomistic simulations of solid state materials for batteries: a focus on olivine NaFePO$_4$ ﻿

(Theoretical Chemistry Accounts, 2017-03-07)
The study of ion transport in electrochemically active materials for energy storage systems requires simulations on quantum-, atomistic- and meso-scales. The methods accessing these scales not only have to be effective but ...
• #### The M-Wright function as a generalization of the Gaussian density for fractional diffusion processes ﻿

(Fractional Calculus and Applied Analysis, 2013-12-31)
The leading role of a special function of the Wright-type, referred to as M-Wright or Mainardi function, within a parametric class of self-similar stochastic processes with stationary increments, is surveyed. This class ...
• #### Two-particle anomalous diffusion: Probability density functions and self-similar stochastic processes ﻿

(Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2013-12-31)
Two-particle 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 self-similar stochastic processes. ...
• #### Sensitivity study of borehole-to-surface and crosswell electromagnetic measurements acquired with energized steel casing to water displacement in hydrocarbon-bearing layers ﻿

(Geophysics, 2008-12-31)
We study the theoretical response of electromagnetically energized steel casing in the presence of subsurface variations of electrical resistivity. Casing is energized with a finite-size solenoid antenna located along the ...
• #### Energy-norm-based and goal-oriented automatic hp adaptivity for electromagnetics: Application to waveguide Discontinuities ﻿

(IEEE Transactions on Microwave Theory and Techniques, 2008-12-31)
The finite-element 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, 2013-12-31)
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 non-monotone coupling ﻿

(Mathematics and Computers in Simulation, 2013-12-31)
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, 2013-12-31)
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 McGehee-type blow-up in order to cope with the singularity of ...
• #### An IMEX scheme combined with Richardson extrapolation methods for some reaction-diffusion equations ﻿

(Idojaras, 2013-12-31)
An implicit-explicit (IMEX) method is combined with some so-called Richardson extrapolation (RiEx) methods for the numerical solution of reaction-diffusion equations with pure Neumann boundary conditions. The results are ...
• #### Editors' preface for the topical issue "Numerical Methods for Large-Scale Scientific Computing, II" ﻿

(Central European Journal of Mathematics, 2013-12-31)
[No abstract available]
• #### Editors' preface for the topical issue "Numerical Methods for Large-Scale Scientific Computing, I" ﻿

(Central European Journal of Mathematics, 2013-12-31)
[No abstract available]
• #### Simulation of DC dual-laterolog measurements in complex formations: A Fourier-series approach with nonorthogonal coordinates and self-adapting finite elements ﻿

(Geophysics, 2009-12-31)
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 multi-frontal parallel direct solver for hp-finite element method ﻿

(Proceedings of the IASTED International Conference on Advances in Computer Science and Engineering, ACSE 2009, 2009-12-31)
In this paper we present the performance of our parallel multi-frontal direct solver when applied to solve linear systems of equations resulting from discretizations of a hp Finite Element Method (hp-FEM). The hp-FEM ...
• #### Simulation of marine controlled source electromagnetic measurements using a parallel fourier hp-finite element method ﻿

(Computational Geosciences, 2011-12-31)
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 Gray-Scott equation ﻿

(SIAM Journal on Mathematical Analysis, 2011-12-31)
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 reaction-diffusion problems ﻿

(Advances in Applied Mathematics and Mechanics, 2011-12-31)
In this work, we present and discuss some modifications, in the form of two-sided estimation (and also for arbitrary source functions instead of usual sign-conditions), of continuous and discrete maximum principles for the ...
• #### Nonobtuse local tetrahedral refinements towards a polygonal face/interface ﻿

(Applied Mathematics Letters, 2011-12-31)
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 three-dimensional domain. The technique ...
• #### Generalization of the Zlámal condition for simplicial finite elements in ℝ d ﻿

(Applications of Mathematics, 2011-12-31)
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 one-center problem with weak forces ﻿

(Discrete and Continuous Dynamical Systems, 2011-12-31)
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 high-order spurious prolate spheroidal modes induced by a local approximate dtn exterior boundary condition ﻿

(Progress In Electromagnetics Research B, 2012-12-31)
We investigate analytically the asymptotic behavior of high-order spurious prolate spheroidal modes induced by a second-order local approximate DtN absorbing boundary condition (DtN2) when employed for solving high-frequency ...