Numerical methods in system design and identification with application to wave propagation in layered media
Numerical minimization of eigenmodes of a membrane with respect to the domain
In this paper we introduce a numerical approach adapted to the minimization of the eigenmodes of a membrane with respect to the domain. This method is based on the combination of the Level Set method of S. Osher and J.A. Sethian with the relaxed approach. This algorithm enables both changing the topology and working on a fixed regular grid.
Numerical minimization of eigenmodes of a membrane with respect to the domain
In this paper we introduce a numerical approach adapted to the minimization of the eigenmodes of a membrane with respect to the domain. This method is based on the combination of the Level Set method of S. Osher and J.A. Sethian with the relaxed approach. This algorithm enables both changing the topology and working on a fixed regular grid.
Numerical modelling of semi-coercive beam problem with unilateral elastic subsoil of Winkler's type
A non-linear semi-coercive beam problem is solved in this article. Suitable numerical methods are presented and their uniform convergence properties with respect to the finite element discretization parameter are proved here. The methods are based on the minimization of the total energy functional, where the descent directions of the functional are searched by solving the linear problems with a beam on bilateral elastic ``springs''. The influence of external loads on the convergence properties is...
Numerical optimization of parameters in systems of differential equations
We present results on the estimation of unknown parameters in systems of ordinary differential equations in order to fit the output of models to real data. The numerical method is based on the nonlinear least squares problem along with the solution of sensitivity equations corresponding to the differential equations. We will present the performance of the method on the problem of fitting the output of basic compartmental epidemic models to data from the Covid-19 epidemic. This allows us to draw...
Numerical procedure to approximate a singular optimal control problem
In this work we deal with the numerical solution of a Hamilton-Jacobi-Bellman (HJB) equation with infinitely many solutions. To compute the maximal solution – the optimal cost of the original optimal control problem – we present a complete discrete method based on the use of some finite elements and penalization techniques.
Numerical resolution of an “unbalanced” mass transport problem
We introduce a modification of the Monge–Kantorovitch problem of exponent 2 which accommodates non balanced initial and final densities. The augmented lagrangian numerical method introduced in [6] is adapted to this “unbalanced” problem. We illustrate the usability of this method on an idealized error estimation problem in meteorology.
Numerical resolution of an “unbalanced” mass transport problem
We introduce a modification of the Monge–Kantorovitch problem of exponent 2 which accommodates non balanced initial and final densities. The augmented Lagrangian numerical method introduced in [6] is adapted to this “unbalanced” problem. We illustrate the usability of this method on an idealized error estimation problem in meteorology.
Numerical solution of soap film dual problems.
Numerical Solution of the Obstacle Problem by the Penalty Method. Part II. Time-Dependent Problem.
Numerical solutions of the mass transfer problem
Let μ and ν be two probability measures on the real line and let c be a lower semicontinuous function on the plane. The mass transfer problem consists in determining a measure ξ whose marginals coincide with μ and ν, and whose total cost ∫∫ c(x,y)dξ(x,y) is minimum. In this paper we present three algorithms to solve numerically this Monge-Kantorovitch problem when the commodity being shipped is one-dimensional and not necessarily confined to a bounded interval. We illustrate these numerical...
Numerically stable algorithm for pole assignment of linear single-input systems
Of an Iterative Procedure for Solving the Optimization Problem into an Ellipsoid
On a devil’s staircase associated to the joint spectral radii of a family of pairs of matrices
The joint spectral radius of a finite set of real matrices is defined to be the maximum possible exponential rate of growth of products of matrices drawn from that set. In previous work with K. G. Hare and J. Theys we showed that for a certain one-parameter family of pairs of matrices, this maximum possible rate of growth is attained along Sturmian sequences with a certain characteristic ratio which depends continuously upon the parameter. In this note we answer some open questions from that paper...
On an iterative method for variational inequalities.
On an optimal setting of constant delays for the D-QSSA model reduction method applied to a class of chemical reaction networks
We develop and test a relatively simple enhancement of the classical model reduction method applied to a class of chemical networks with mass conservation properties. Both the methods, being (i) the standard quasi-steady-state approximation method, and (ii) the novel so-called delayed quasi-steady-state approximation method, firstly proposed by Vejchodský (2014), are extensively presented. Both theoretical and numerical issues related to the setting of delays are discussed. Namely, for one slightly...
On computer aided shape optimization
On Condition Numbers and the Distance to the Nearest Ill-posed Problem.
On Finite Element Approximation in the L...-Norm of Variational Inequalities.
On Henrici's transformation in optimization
Henrici’s transformation is a generalization of Aitken’s -process to the vector case. It has been used for accelerating vector sequences. We use a modified version of Henrici’s transformation for solving some unconstrained nonlinear optimization problems. A convergence acceleration result is established and numerical examples are given.