General decay of solutions of a wave equation with a boundary control of memory type

In this paper we consider a semilinear wave equation, in a bounded domain, where the memory-type damping is acting on a part of the boundary. We establish a general decay result, from which the usual exponential and polynomial decay rates are only special cases. Our work allows certain relaxation functions which are not necessarily of exponential or polynomial decay and, therefore, generalizes and improves earlier results in the literature.     

Energy decay for Timoshenko systems of memory type

Linear systems of Timoshenko type equations for beams including a memory term are studied. The exponential decay is proved for exponential kernels, while polynomial kernels are shown to lead to a polynomial decay. The optimality of the results is also investigated.     

General decay for a differential inclusion of Kirchhoff type with a memory condition at the boundary

In this article, we consider a differential inclusion of Kirchhoff type with a memory condition at the boundary. We prove the asymptotic behavior of the corresponding solutions. For a wider class of relaxation functions, we establish a more general decay result, from which the usual exponential and polynomial decay rates are only special cases.     

General energy decay in a Timoshenko-type system of thermoelasticity of type III with a viscoelastic damping

In this paper we consider a one-dimensional linear thermoelastic system of Timoshenko type, where the heat conduction is given by Green and Naghdi theories. We prove a general decay result, from which the exponential and polynomial decays are only special cases.     

Energy decay rates for a hyperbolic differential inclusion with viscoelastic boundary conditions

In this paper, we consider a hyperbolic differential inclusion with viscoelastic boundary conditions localized on a part of the boundary. For a wider class of relaxation functions, we establish a more general decay result, from which the usual exponential and polynomial decay rates are only special cases. Copyright © 2013 John Wiley & Sons, Ltd.     

Boundary stabilization of solutions of a nonlinear system of Timoshenko type

In this paper we are concerned with a multidimensional Timoshenko system subjected to boundary conditions of memory type. We establish general rate decay results. The usual exponential and polynomial decay rates are only special cases.     

Existence and decay rates for a coupled Balakrishnan-Taylor viscoelastic system with dynamic boundary conditions

In this paper, we are concerned with a coupled viscoelastic wave system with Balakrishnan-Taylor dampings, dynamic boundary conditions, source terms, and past histories. Under suitable assumptions on relaxation functions and source terms, we prove the global existence of solutions by potential well theory and we establish a more general decay result of energy, in which the exponential decay and polynomial decay are only special cases, by introducing suitable energy and perturbed Lyapunov functionals.     

A general decay result for a memory-type thermoelasticity with second sound

In this paper, we consider an n-dimensional system of thermoelasticity with second sound in the presence of a viscoelastic term acting in the domain. We prove a general decay result from which the usual exponential and polynomial decay results are only special cases.     

General boundary stabilization of memory type in thermoelasticity of type III

In this paper, we consider a multi-dimensional system of thermoelasticity type III with a viscoelastic damping acting on a part of the boundary. We establish a general decay result, from which the usual exponential and polynomial decay rates are only special cases.     

General decay to a von Kármán system with memory

In this paper we study the von Kármán plate model with long-range memory and we show the general decay of the solution as time goes to infinity. This result generalizes and improves on earlier ones in the literature because it allows certain relaxation functions which are not necessarily of exponential or polynomial decay.     

Stability of solution for a mixture of thermoelastic of type III

In this work, we analyze the existence, uniqueness, and asymptotic behavior of solution to the model of a thermoelastic mixture of type III. We establish sufficient conditions to guarantee the exponential decay of solutions. When the decay is not of exponential type, we prove that the solutions decay polynomially and we find the optimal polynomial decay rate. Copyright © 2017 John Wiley & Sons, Ltd.     

General decay of solutions in one-dimensional porous-elastic system with memory

In this work we consider a one-dimensional porous-elastic system with memory effects. It is well-known that porous-elastic system with a single dissipation mechanism lacks exponential decay. In contrary, we prove that the unique dissipation given by the memory term is strong enough to exponentially stabilize the system, depending on the kernel of the memory term and the wave speeds of the system. In fact, we prove a general decay result, for which exponential and polynomial decay results are special cases. Our result is new and improves previous results in the literature.     

General stability of solutions for a viscoelastic wave equations of Kirchhoff type with acoustic boundary conditions

In this paper, we study a viscoelastic wave equations of Kirchhoff type with acoustic boundary conditions. For a viscoelastic wave equations of Kirchhoff type without strong damping, we prove an explicit and general decay rate result, using some properties of the convex functions. For a wider class of relaxation functions, we establish a more general decay result, from which the usual exponential and polynomial decay rates are only special cases. Copyright © 2016 John Wiley & Sons, Ltd.     

General decay for a porous thermoelastic system with memory: The case of equal speeds

In this paper we consider a one-dimensional system with porous elasticity in the presence of a visco-porous dissipation and a macrotemperature effect. We establish a general decay result, of which the exponential and the polynomial results of Soufyane (2008) [10] are merely special cases.     

Damping of end effects in a thermoelastic theory

The aim of this paper is to present a spatial decay estimate in the thermoelasticity of Type III. We prove that the rate of decay is bounded below by an exponential of a second degree polynomial of the distance.     

Mean square polynomial stability of numerical solutions to a class of stochastic differential equations

The exponential stability of numerical methods to stochastic differential equations (SDEs) has been widely studied. In contrast, there are relatively few works on polynomial stability of numerical methods. In this letter, we address the question of reproducing the polynomial decay of a class of SDEs using the Euler–Maruyama method and the backward Euler–Maruyama method. The key technical contribution is based on various estimates involving the gamma function.     

Asymptotic stability of semigroups associated with linear weak dissipative systems with memory

We study the asymptotic behavior of the solutions of a class of linear dissipative integral differential equations. We show in the abstract setting a necessary and sufficient condition to get an exponential decay of the solution. In the case of the lack of exponential decay, we find the polynomial rate of decay of the solution. Some examples are given.     

Pointwise convergence of derivatives of Lagrange interpolation polynomials for exponential weights

For a general class of exponential weights on the line and on (−1,1), we study pointwise convergence of the derivatives of Lagrange interpolation. Our weights include even weights of smooth polynomial decay near ±∞ (Freud weights), even weights of faster than smooth polynomial decay near ±∞ (Erdös weights) and even weights which vanish strongly near ±1, for example Pollaczek type weights.     

Sharp adaptation for spherical inverse problems with applications to medical imaging

This paper examines the estimation of an indirect signal embedded in white noise for the spherical case. It is found that the sharp minimax bound is determined by the degree to which the indirect signal is embedded in the linear operator. Thus, when the linear operator has polynomial decay, recovery of the signal is polynomial, whereas if the linear operator has exponential decay, recovery of the signal is logarithmic. The constants are determined for these classes as well. Adaptive sharp estimation is also carried out. In the polynomial case a blockwise shrinkage estimator is needed while in the exponential case, a straight projection estimator will suffice. The framework of this paper include applications to medical imaging, in particular, to cone beam image reconstruction and to diffusion magnetic resonance imaging. Discussion of these applications are included.     

Polynomial stability of a coupled system of wave equations weakly dissipative

In this work, we consider a coupled system of wave equation. We show that the solution of this system has a polynomial rate of decay as time tends to infinity, but does not have exponential decay. We presented a class of examples of application of the main result.