Jaime H. Ortega

Learn More
In this work we prove the generic simplicity of the spectrum of the clamped plate equation in a bounded regular domain of Rd. That is, given Ω ⊂ Rd, we show that there exists an arbitrarily small deformation of the domain u, such that all the eigenvalues of the plate system in the deformed domain Ω + u are simple. To prove this result we first prove a(More)
In this paper, we investigate the problem of the detection of a moving obstacle in a perfect fluid occupying a bounded domain in R from the measurement of the velocity of the fluid on one part of the boundary. We show that when the obstacle is a ball, we may identify the position and the velocity of its centre of mass from a single boundary measurement.(More)
Abstract. In this paper we investigate the motion of a rigid ball in an incompressible perfect fluid occupying R. We prove the global in time existence and the uniqueness of the classical solution for this fluid-structure problem. The proof relies mainly on weighted estimates for the vorticity associated with the strong solution of a fluid-structure problem(More)
In this article we develop a model to help a maintenance decision-making situation of a given equipment. We propose a novel model to determine optimal life-cycle duration and intervals between overhauls by minimizing global maintenance costs. We consider a situation where the customer, which owns the equipment, may negotiate a better warranty contract by(More)
In this work, we study an approximate control problem for the heat equation, with a nonstandard but rather natural restriction on the solution. It is well known that approximate controllability holds. On the other hand, the total mass of the solutions of the uncontrolled system is constant in time. Therefore, it is natural to analyze whether approximate(More)
This study investigates the effects of different solid models on predictions of brain shift for three craniotomies. We created a generic 3D brain model based on healthy human brain and modeled the brain parenchyma as single continuum and constrained by a practically rigid skull. We have used elastic model, hyperelastic 1st, 2nd, and 3rd Ogden models, and(More)
In this work we are interested in the study of controllability and stabilization of the linearized Benjamin-Ono equation with periodic boundary conditions, which is a generic model for the study of weakly nonlinear waves with nonlocal dispersion. It is well known that the Benjamin-Ono equation has infinite number of conserved quantities, thus we consider(More)
In this work, we study the Bloch wave decomposition for the Stokes equations in a periodic media in Rd. We prove that, because of the incompressibility constraint, the Bloch eigenvalues, as functions of the Bloch frequency ξ, are not continuous at the origin. Nevertheless, when ξ goes to zero in a fixed direction, we exhibit a new limit spectral problem for(More)