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On periodic solution of a nonlinear beam equation

Marie Kopáčková (1983)

Aplikace matematiky

the existence of an ω -periodic solution of the equation 2 u t 2 + α 4 u x 4 + γ 5 u x 4 t - γ ˜ 3 u x 2 t + δ u t - β + 0 n u x 2 ( · , ξ ) d ξ + σ 0 n 2 u x t ( · , ξ ) u x ( · , ξ ) d ξ 2 u x 2 = f sarisfying the boundary conditions u ( t , 0 ) = u ( t , π ) = 2 u x 2 t , 0 = 2 u x 2 t , π = 0 is proved for every ω -periodic function f C 0 , ω , L 2 .

On the approximate solution of the multi-group time-dependent transport equation by P L -method

Stanislav Míka (1979)

Aplikace matematiky

This paper concerns l -velocity model of the general linear time-dependent transport equation. The assumed probability of the collision (scattering, fission) depends only on the angle of the directions of the moving neutron before and after the collision. The weak formulation of the problem is given and a priori estimates are obtained. The construction of an approximate problem by bad hbox-method is given. In the symmetric hyperbolic system obtained by bad hbox-method dissipativity and 𝒜 -orthogonality of the relevant...

On the interior boundary-value problem for the stationary Povzner equation with hard and soft interactions

Vladislav A. Panferov (2004)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

The Povzner equation is a version of the nonlinear Boltzmann equation, in which the collision operator is mollified in the space variable. The existence of stationary solutions in L 1 is established for a class of stationary boundary-value problems in bounded domains with smooth boundaries, without convexity assumptions. The results are obtained for a general type of collision kernels with angular cutoff. Boundary conditions of the diffuse reflection type, as well as the given incoming profile, are...

On the unique solvability of a nonlocal phase separation problem for multicomponent systems

Jens A. Griepentrog (2004)

Banach Center Publications

A nonlocal model of phase separation in multicomponent systems is presented. It is derived from conservation principles and minimization of free energy containing a nonlocal part due to particle interaction. In contrast to the classical Cahn-Hilliard theory with higher order terms this leads to an evolution system of second order parabolic equations for the particle densities, coupled by nonlinear and nonlocal drift terms, and state equations which involve both chemical and interaction potential...

On three problems of neutron transport theory

Jan Kyncl (1986)

Aplikace matematiky

In this paper, the initial-value problem, the problem of asymptotic time behaviour of its solution and the problem of criticality are studied in the case of linear Boltzmann equation for both finite and infinite media. Space of functions where these problems are solved is chosen in such a vay that the range of physical situations considered may be so wide as possible. As mathematical apparatus the theory of positive bounded operators and of semigroups are applied. Main results are summarized in...

One-dimensional model describing the non-linear viscoelastic response of materials

Tomáš Bárta (2014)

Commentationes Mathematicae Universitatis Carolinae

In this paper we consider a model of a one-dimensional body where strain depends on the history of stress. We show local existence for large data and global existence for small data of classical solutions and convergence of the displacement, strain and stress to zero for time going to infinity.

Currently displaying 21 – 40 of 43