Search results for " and Control"

Conjugate and cut loci in averaged orbital transfer

2006

The objective of this Note is to describe the conjugate and cut loci associated with the averaged energy minimization problem in coplanar orbit transfer.

Time minimization versus energy minimization in the one-input controlled Kepler problem with weak propulsion

2014

International audience

Algebraic-geometric techniques for the feedback classification and robustness of the optimal control of a pair of Bloch equations with application to…

2017

The aim of this article is to classify the singular trajectories associated with the optimal control problems of a pair of controlled Bloch equations. The motivation is to analyze the robustness of the optimal solutions to the contrast and the time-minimal saturation problem, in magnetic resonance imaging, with respect to the parameters and B1-inhomogeneity. For this purpose, we use various computer algebra algorithms and methods to study solutions of polynomial systems of equations and inequalities which are used for classification issues: Gröbner basis, cylindrical algebraic decomposition of semi-algebraic sets, Thom's isotopy lemma.

Recherche Tabou Robuste pour l'allocation de fréquences

2014

National audience; 1. Problématique : depuis le démarrage des réseaux cellulaires (2G, 3G, 3.5G), les opérateurs configuraient manuellement la gestion des paramètres réseau. Avec l'apparition des réseaux 4G/LTE, la notion de Self-Organizing Network (SON) a vu le jour. Les SON introduisent des fonctions avancées de paramétrage automatique du réseau en fonction de la demande. Grâce à cette technologie, les opérateurs peuvent désormais améliorer la flexibilité et les performances du réseau en réduisant les coûts d'exploitation. Notre objectif est de proposer des solutions algorithmiques pouvant s'appliquer au SON. 2. Méthodologie : le problème d'allocation de fréquences est NP-difficile car il…

One-parameter family of Clairaut-Liouville metrics

2007

Riemannian metrics with singularities are considered on the $2$-sphere of revolution. The analysis of such singularities is motivated by examples stemming from mechanics and related to projections of higher dimensional (regular) sub-Riemannian distributions. An unfolding of the metrics in the form of an homotopy from the canonical metric on $\SS^2$ is defined which allows to analyze the singular case as a limit of standard Riemannian ones. A bifurcation of the conjugate locus for points on the singularity is finally exhibited.

Intern conflicts and a production function with combining sub-factors

1994

Considering sub-factors, like different categories of capital or different categories of work, a production function is proposed: each sub-factor of one factor may be combined with each sub-factor of the other factor. Different types of programs exists at different levels. The conditions to obtain identical solution for these programs are studied. Considering that there is one responsible manager by program, conflicts between managers of each program arepossible because these programs give non identical solutions in general. The important fact is that these intern conflicts appear naturally without extra economical considerations

Sub-Riemannian geometry: one-parameter deformation of the Martinet flat case

1998

Kernel Density Estimation applied to the chance-constrained Goddard problem

2016

Optimisation d’un lanceur

2015

Localization from inertial data and sporadic position measurements

2020

International audience; A novel estimation strategy for inertial navigation in indoor/outdoor environments is proposed with a specific attention to the sporadic nature of the non-periodic measurements. After introducing the inertial navigation model, we introduce an observer providing an asymptotic estimate of the plant state. We use a hybrid dynamical systems representation for our results, in order to provide an effective, and elegant theoretical framework. The estimation error dynamics with the proposed observer shows a peculiar cascaded interconnection of three subsystems (allowing for intuitive gain tuning), with perturbations occurring either on the jump or on the flow dynamics (depen…