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Redaktion: K. Sigmund, G. Greschonig (Univ. Wien, Strudlhofgasse ...

Redaktion: K. Sigmund, G. Greschonig (Univ. Wien, Strudlhofgasse ...

Redaktion: K. Sigmund, G. Greschonig (Univ. Wien, Strudlhofgasse ...

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154 Numerische Mathematik, Wissenschaftliches Rechnen<br />

and below up to multiplicative constants that do neither depend on the meshsize<br />

nor on the plate’s thickness and are uniform for a wide range of stabilisation<br />

parameter. The error is controlled in norms that are known to converge to zero in<br />

a quasi-optimal way.<br />

[1] C. Carstensen, J. Schöberl: Residual-Based A Posteriori Error Estimate for<br />

a Mixed Reissner-Mindlin Plate Finite Element Method. SFB-Report No.<br />

00-31, Johannes Kepler <strong>Univ</strong>ersität Linz, SFBF013, Linz, Austria<br />

The Numerics of Nonlinear Parabolic Problems<br />

MECHTHILD THALHAMMER<br />

(gemeinsam mit Alexander Ostermann)<br />

Department of Engineering Mathematics, Geometry and Computer Science,<br />

<strong>Univ</strong>. of Innsbruck, Technikerstraße 13, 6020 Innsbruck<br />

Mechthild.Thalhammer@uibk.ac.at<br />

http://techmath.uibk.ac.at/mathematik/thalhammer/<br />

We consider fully nonlinear initial-boundary value problems of parabolic type<br />

modelling for example nonlinear diffusion or heat conduction processes. When<br />

we apply a numerical method for discretizing such a problem in time, a matter<br />

of interest is whether the discretization reproduces the trajectories and whether it<br />

captures the dynamics of the underlying problem correctly.<br />

For the analysis, we write the partial differential equation as abstract ordinary differential<br />

equation, and we work in the framework of analytic semigroups and Banach<br />

space valued Hölder continuous functions. For the classes of implicit Runge-<br />

Kutta and linear multistep methods we show that the quantitative and qualitative<br />

properties of the original problem are well preserved.<br />

Simulation of the Dynamics of Tethered Satellite Systems<br />

HANS TROGER<br />

(gemeinsam mit M.Matzl, W.Poth, A.Steindl, G.Wiedermann)<br />

Institut für Mechanik, TU <strong>Wien</strong><br />

Hans.Troger@tuwien.ac.at<br />

http://mch2ws2.mechanik.tuwien.ac.at/˜htroger<br />

The dynamics of tethered satellite systems, that is an arrangement of two or more<br />

satellites, which are connected by thin long cables in orbit around a planet, is described<br />

by a coupled set of nonlinear ordinary and partial differential equations.<br />

We present the equations in weak form, which for the system of varying mass<br />

composition is nontrivial. Since the equations are stiff their numerical treatment<br />

requires special measures. One possibility is to introduce an alternative set of<br />

variables (natural string variables) for the description of the deformation of the

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