Parameter estimation problem for a damped sine-Gordon equation (original) (raw)

Optimal Parameters for a Damped Sine-Gordon Equation

Journal of the Korean Mathematical Society, 2009

In this paper a parameter identification problem for a damped sine-Gordon equation is studied from the theoretical and numerical perspectives. A spectral method is developed for the solution of the state and the adjoint equations. The Powell's minimization method is used for the numerical parameter identification. The necessary conditions for the optimization problem are shown to yield the bang-bang control law. Numerical results are discussed and the applicability of the necessary conditions is examined.

Identification problem for damped sine-Gordon equation with point sources

Journal of Mathematical Analysis and Applications, 2011

We establish the existence and uniqueness of solutions for sine-Gordon equations in a multidimensional setting. The equations contain a point-like source. Furthermore, the continuity and the Gâteaux differentiability of the solution map is established. An identification problem for parameters governing the equations is set, and is shown to have a solution. The objective function is proved to be Fréchet differentiable with respect to the parameters. An expression for the Fréchet derivative in terms of the solutions of the direct and the adjoint systems is presented. A criterion for optimal parameters is formulated as a bang-bang control principle. An application of these results to the one-dimensional sine-Gordon equation is considered.

Optimal parameters for damped sine-Gordon equations with Neumann boundary condition

2011

In this paper we study an identification problem for physical parameters associated with damped sine-Gordon equation with Neumann boundary conditions. The existence, uniqueness, and continuous dependence of weak solution of sine-Gordon equations are established. The method of transposition is used to prove the Gâteaux differentiability of the solution map. The Gâteaux differential of the solution map is characterized. The optimal parameters are established. Computational algorithm and numerical results are presented.

Identifiability for Linearized Sine-Gordon Equation

Mathematical Modelling of Natural Phenomena, 2013

The paper presents theoretical and numerical results on the identifiability, i.e. the unique identification for the one-dimensional sine-Gordon equation. The identifiability for nonlinear sine-Gordon equation remains an open question. In this paper we establish the identifiability for a linearized sine-Gordon problem. Our method consists of a careful analysis of the Laplace and Fourier transforms of the observation of the system, conducted at a single point. Numerical results based on the best fit to data method confirm that the identification is unique for a wide choice of initial approximations for the sought test parameters. Numerical results compare the identification for the nonlinear and the linearized problems.

Identification problems for the damped Klein–Gordon equations

Journal of Mathematical Analysis and Applications, 2004

In this paper we study the identification problems for the damped Klein-Gordon equation (KG). In particular, when the diffusion parameter of KG is unknown, we prove the existence of the optimal parameter and deduce the necessary conditions on the optimal parameter by using the transposition method.

Control for the sine-gordon equation

ESAIM: Control, Optimisation and Calculus of Variations, 2004

In this article we apply the optimal and the robust control theory to the sine-Gordon equation. In our case the control is given by the boundary conditions and we work in a finite time horizon. We present at the beginning the optimal control problem and we derive a necessary condition of optimality and we continue by formulating a robust control problem for which existence and uniqueness of solutions are derived.

Simultaneous identification of damping coefficient and initial value for PDEs from boundary measurement

International Journal of Control, 2017

In this paper, the simultaneous identification of damping or anti-damping coefficient and initial value for some PDEs is considered. An identification algorithm is proposed based on the fact that the output of system happens to be decomposed into a product of an exponential function and a periodic function. The former contains information of the damping or antidamping coefficient, while the latter does not. The convergence and error analysis are also developed. Three examples, namely, an anti-stable wave equation with boundary anti-damping, a Schrödinger equation with internal anti-damping, and two connected strings with middle joint anti-damping, are investigated and demonstrated by numerical simulations to show the effectiveness of the proposed algorithm.