Identification de paramètres dans les problèmes non linéaires à données incomplètes
Identification of a Duffing oscillator under different types of excitation.
Identification of a wave equation generated by a string
We show that we can reconstruct two coefficients of a wave equation by a single boundary measurement of the solution. The identification and reconstruction are based on Krein’s inverse spectral theory for the first coefficient and on the Gelfand−Levitan theory for the second. To do so we use spectral estimation to extract the first spectrum and then interpolation to map the second one. The control of the solution is also studied.
Identification of quasiperiodic processes in the vicinity of the resonance
In nonlinear dynamical systems, strong quasiperiodic beating effects appear due to combination of self-excited and forced vibration. The presence of symmetric or asymmetric beatings indicates an exchange of energy between individual degrees of freedom of the model or by multiple close dominant frequencies. This effect is illustrated by the case of the van der Pol equation in the vicinity of resonance. The approximate analysis of these nonlinear effects uses the harmonic balance method and the multiple...
Identification problems for degenerate parabolic equations
This paper deals with multivalued identification problems for parabolic equations. The problem consists of recovering a source term from the knowledge of an additional observation of the solution by exploiting some accessible measurements. Semigroup approach and perturbation theory for linear operators are used to treat the solvability in the strong sense of the problem. As an important application we derive the corresponding existence, uniqueness, and continuous dependence results for different...
Ignition for a gaseous thermal reaction
Immunological barrier for infectious diseases
A nonlinear mathematical model with distributed delay is proposed to describe the reaction of a human organism to a pathogen agent. The stability of the disease free state is analyzed, showing that there exists a large set of initial conditions in the attraction basin of the disease-free state whose border is defined as the immunological barrier.
Implicit constitutive solution scheme for Mohr-Coulomb plasticity
This contribution summarizes an implicit constitutive solution scheme of the elastoplastic problem containing the Mohr-Coulomb yield criterion, a nonassociative flow rule, and a nonlinear isotropic hardening. The presented scheme builds upon the subdifferential formulation of the flow rule leading to several improvements. Mainly, it is possible to detect a position of the unknown stress tensor on the Mohr-Coulomb pyramid without blind guesswork. Further, a simplified construction of the consistent...
Implicit Differential Equation In Locally Convex Spaces
Implicit Differential Equations From the Singularity Theory Viewpoint
Implicit quasilinear differential systems: A geometrical approach.
Implicit Runge-Kutta methods for transferable differential-algebraic equations
The numerical solution of transferable differential-algebraic equations (DAE’s) by implicit Runge-Kutta methods (IRK) is studied. If the matrix of coefficients of an IRK is non-singular then the arising systems of nonlinear equations are uniquely solvable. These methods are proved to be stable if an additional contractivity condition is satisfied. For transferable DAE’s with smooth solution we get convergence of order , where is the classical order of the IRK and is the stage order. For transferable...
Importance of brood maintenance terms in simple models of the honeybee - Varroa destructor - acute bee paralysis virus complex.
Improved K-K algorithm for computing Lyapunov values
Improved robust stability criteria of uncertain neutral systems with mixed delays.
Improvement of Numerical Solution of Boundary Layer Problems by Incorporation of Asymptotic Approximations.
Impulse control in Kalman-like filtering problems.
Impulsive boundary value problems for -Laplacian’s via critical point theory
In this paper we investigate the existence of solutions to impulsive problems with a -Laplacian and Dirichlet boundary value conditions. We introduce two types of solutions, namely a weak and a classical one which coincide because of the fundamental lemma of the calculus of variations. Firstly we investigate the existence of solution to the linear problem, i.e. a problem with a fixed rigth hand side. Then we use a direct variational method and next a mountain pass approach in order to get the existence...
Impulsive boundary-value problems for first-order integro-differential equations.
Impulsive controllability of linear dynamical systems with applications to maneuvers of spacecraft.