Volume 04

Solvability of a Hybrid Model for a Vertical Slender Structure

Issues 3-4 Volume 04

Date of Online Publication: 02/11/2010 Keywords: Existence results, beam vibration, damping, hybrid model. Abstract: We consider the solvability of a hybrid model for the vibration of a vertical slender structure mounted on an elastic seating. The slender structure is modeled as a Rayleigh beam and gravity is taken into account. The seating and foundation block […]

Detecting Discontinuities in Two-Dimensional Signals Sampled on a Grid

Issues 3-4 Volume 04

Date of Online Publication: 02/11/2010 Keywords: Edge detection, discontinuities, wavelets, polyharmonic splines. Abstract: In this paper we consider the problem of detecting, from a finite discrete set of points, the curves across which a two-dimensional function is discontinuous. We propose a strategy based on wavelets which allows to discriminate the edge points from points in

Blended General Linear Methods based on Boundary Value Methods in the Generalized BDF family

Issues 1-2 Volume 04

Keywords: Numerical methods for ordinary differential equations, General Linear Methods, Boundary Value Methods (BVMs), Generalized Backward Differentiation Formulae (GBDF), Blended Implicit Methods, blended iteration. Abstract: Among the methods for solving ODE-IVPs, the class of General Linear Methods (GLMs) is able to encompass most of them, ranging from Linear Multistep Formulae (LMF) to RK formulae. Moreover,

An Efficient Scheme for Meshless Analysis Based on Radial Basis Functions

Issues 3-4 Volume 04

Date of Online Publication: 02/11/2010 Keywords: Partial Differential Equations, Meshless Method, Radial Basis Function, Radial Point Interpolation Abstract: A meshless method based on radial point interpolation was recently developed as an effective tool for solving partial differential equations, and has been widely applied to a number of different problems. In addition to the primary advantage

Forty-Five Years of A-stability

Issues 1-2 Volume 04

Keywords: Stiff problems, A-stability, stability barriers, order stars, order arrows, nonlinear stability. Abstract: We discuss two events with profound implications on the way initial value problems are solved numerically. The first was the identification of stiffness as a widely spread phenomenon affecting the ability to obtain useful results. The second was the definition of A-stability

Energy Drift in the Numerical Integration of Hamiltonian Problems

Issues 3-4 Volume 04

Date of Online Publication: 02/11/2010 Keywords: Time reversal symmetry, Reversible Hamiltonian systems, Symmetric methods, Periodic orbits, Numerical drift. Authors: Pages: Abstract: When approximating reversible Hamiltonian problems, the presence of a “drift” in the numerical values of the Hamiltonian is sometimes experienced, even when reversible methods of integration are used. In this paper we analyze the

Numerical Solution of Stochastic Differential Equations with Additive Noise by Runge-Kutta Methods

Issues 3-4 Volume 04

Date of Online Publication: 02/11/2010 Keywords: Stochastic Differential Equations, Additive Noise, Numerical Solution, Runge- Kutta methods Periodic orbits, Numerical drift. Authors: Foivos Xanthos and George Papageorgiou Abstract: In this paper we study the numerical treatment of Stochastic Differential Equations with additive noise and one dimensional Wiener process. We develop two, three and four stage Runge-Kutta

Spectral Approximation of Time Windows in the Solution of Dissipative Linear Differential Equations

Issues 1-2 Volume 04

Keywords: Linear differential systems, time window, spectral approximation, waveform relaxation. Abstract: We establish a relation between the length T of the integration window of a linear differential equation x’+Ax = b and a spectral parameter s*. This parameter is determined by comparing the exact solution x(T) at the end of the integration window to the

Simulation and Inversion of Seismic Wave Propagation on Continental Scales Based on a Spectral-Element Method

Issues 1-2 Volume 04

Keywords: seismic tomography, spectral-element method, adjoint-method, Australia Abstract: We propose a novel technique for seismic waveform tomography on continental scales. This is based on the fully numerical simulation of wave propagation in complex Earth models, the inversion of complete waveforms and the quantification of the waveform discrepancies through a specially designed phase misfit. The numerical

Scroll to Top