arXiv subjects

Michael Pokojovy

Publications and source records attributed to Michael Pokojovy.

22 records · Page 2Linked to original sources

arXiv2014

On Classical Solvability for a Linear 1D Heat Equation with Constant Delay

In this paper, we consider a linear heat equation with constant coefficients and a single constant delay. Such equations are commonly used to model and study various problems arising in ecology and population biology when describing the temporal evolution of human or animal populations accounting for migration, interaction with the environment and certain aftereffects caused by diseases or enviromental polution, etc. Whereas dynamical systems with lumped parameters have been addressed in numerous investigations, there still remain a lot of open questions for the case of systems with distributed parameters, especially when the delay effects are incorporated. Here, we consider a general non-homogeneous one-dimensional heat equation with delay in both higher and lower order terms subject to non-homogeneous initial and boundary conditions. For this, we prove the unique existence of a classical solution as well as its continuous dependence on the data.

math.AP↗

arXiv2014

Construction of Exact Control for a One-Dimensional Heat Equation with Delay

We prove an exact controllability result for a one-dimensional heat equation with delay in both lower and highest order terms and nonhomogeneous Dirichlet boundary conditions. Moreover, we give an explicit representation of the control function steering the system into a given final state. Under certain decay properties for corresponding Fourier coefficients which can be interpreted as a sufficiently high Sobolev regularity of the data, both control function and the solution are proved to be regular in the classical sense both with respect to time and space variables.

math.OC↗

arXiv2014

Representation of Classical Solutions to a Linear Wave Equation with Pure Delay

For a wave equation with pure delay, we study an inhomogeneous initial-boundary value problem in a bounded 1D domain. Under smoothness assumptions, we prove unique existence of classical solutions for any given finite time horizon and give their explicit representation. Continuous dependence on the data in a weak extrapolated norm is also shown.

math.AP↗

arXiv2014

On Stability of Hyperbolic Thermoelastic Reissner-Mindlin-Timoshenko Plates

In the present article, we consider a thermoelastic plate of Reissner-Mindlin-Timoshenko type with the hyperbolic heat conduction arising from Cattaneo's law. In the absense of any additional mechanical dissipations, the system is often not even strongly stable unless restricted to the rotationally symmetric case, etc. We present a well-posedness result for the linear problem under general mixed boundary conditions for the elastic and thermal parts. For the case of a clamped, thermally isolated plate, we show an exponential energy decay rate under a full damping for all elastic variables. Restricting the problem to the rotationally symmetric case, we further prove that a single frictional damping merely for the bending compoment is sufficient for exponential stability. To this end, we construct a Lyapunov functional incorporating the Bogovskiĭ operator for irrotational vector fields which we discuss in the appendix.

math.AP↗