starting from two-dimensional (2d) equations of motion, discretized formulations for transient behavior of soil-structure interaction problems have been derived. two different dynamic infinite elements taking into account single and two-wave types are presented in transformed space. by coupling the infinite elements with standard finite elements, an ordinary finite element procedure is used for...

The usual framework of control is the one given in probably the most studied control problem, stochastic regulator control problem, which deals with minimizing a performance index of a system governed by a set of differential equations. The stochastic linear regulator problem has been studied by many authors including Bensoussan [4], Fleming and Soner [9] for nondegenerate diffusions. Da Prato ...

Spatially implicit metapopulation models with discrete patch-size structure and host-macroparasite models which distinguish hosts by their parasite loads lead to infinite systems of ordinary differential equations. In several papers, a this-related theory will be developed in sufficient generality to cover these applications. In this paper the linear foundations are laid. They are of own intere...

pollution has become a very serious threat to our environment. monitoring pollution is the rst step toward planning to save the environment. the use of dierential equations, monitoring pollution has become possible. in this paper, a ritz-collocation method is introduced to solve non-linear oscillatory systems such as modelling the pollution of a system of lakes. the method is based upon bernoul...

We study the thermoelastic deformation of an elastic layer. The upper surface of the medium is subjected to a uniform thermal field along a circular area while the layer is resting on a rigid smooth circular base. The doubly mixed boundary value problem is reduced to a pair of systems of dual integral equations. The both system of the heat conduction and the mechanical problems are calculated b...

This paper presents a simple and pract ical method to solve the equilïbrium equations of a Markov chain when the number of s ta tes is inf i n i t e . The basic idea is to reduce the inf ini te system of l inear equations to a f in i t e system using the geometrie ta i l behavior of the equil ibrium probabil i t ies . Conditions a re given under which such a reduction is possible. The reduction...