Search results for "processus."

Survey sampling for functionnal data : building asymptotic confidence bands and considering auxiliary information

2011

When collections of functional data are too large to be exhaustively observed, survey sampling techniques provide an effective way to estimate global quantities such as the population mean function, without being obligated to store all the data. In this thesis, we propose a Horvitz–Thompson estimator of the mean trajectory, and with additional assumptions on the sampling design, we state a functional Central Limit Theorem and deduce asymptotic confidence bands. For a fixed sample size, we show that stratified sampling can greatly improve the estimation compared to simple random sampling. In addition, we extend Neyman’s rule of optimal allocation to the functional context. Taking into accoun…

At the centre of The Bologna process: do European Universities train their students to face knowledge-based societies?

2006

L’économie actuelle fondée sur la connaissance impose de nouve aux défis à l’enseignement supérieur. Le principal objectif de cet article est d’évaluer dans quelle mesure les universités sont prêtes à faire face à cesdéfis. Cette question peut être abordée en prenant en compte une des principales fonctions de l’université, qui est de former la main-d’œuvrehautement qualifiée. Les principales questions suivante seront traitées : est-ceque les universités européennes développent les compétences requises parl’économie fondée sur la connaissance ? Quelles sont les compétences valorisées sur le marché du travail ? Au-delà de la valeur monétaire des compétences, quelle sont les plus demandées ? Q…

Noise contribution to resonance phenomena and information propagation in non linear electronic networks

2015

This manuscript presents research aiming to show possible positive effects of deterministic and stochastic perturbations on the responses of different nonlinear systems. To that end, both numerical and experimental studies were carried out on two kinds of structures : an elementary electronic FitzHugh-Nagumo oscillator and an electrical line developed by resistively coupling 45 elementary cells. In the first section, the elementary cell characterization was undertaken in a deterministic regime. In the presence of a bichromatic stimulus, it is shown that when the low frequency component is subthreshold, its detection can be maximized for an optimal magnitude of the second component thanks to…

Analyse et Estimations Spectrales des Processus alpha-Stables non-Stationnaires

2006

In this work a new spectral representation of a symmetric alpha-stable processes is introduced. It is based on a covariation pseudo-additivity and Morse-Transue's integral with respect to a bimesure built by using pseudo-additivity property. This representation, specific to S$\alpha$S processes, is analogous to the covariance of second order processes. On the other hand, it generalizes the representation established for stochastic integrals with respect to symmetric alpha-stable process of independent increments. We provide a classification of non-stationary harmonizable processes; this classification is based on the bimesure structure. In particular, we defined and investigated periodicall…

Differential inclusions involving normal cones of nonregular sets in Hilbert spaces

2017

This thesis is dedicated to the study of differential inclusions involving normal cones of nonregular sets in Hilbert spaces. In particular, we are interested in the sweeping process and its variants. The sweeping process is a constrained differential inclusion involving normal cones which appears naturally in several applications such as elastoplasticity, electrical circuits, hysteresis, crowd motion, etc.This work is divided conceptually in three parts: Study of positively alpha-far sets, existence results for differential inclusions involving normal cones and characterizations of Lyapunov pairs for the sweeping process. In the first part (Chapter 2), we investigate the class of positivel…

Allocation des ressources dans l’informatique en brouillard le calcul du brouillard véhiculaire pour une utilisation optimale des véhicules électriqu…

2019

Abstract: Technological advancements made it possible for Electric vehicles (EVs) to have onboard computation, communication, storage, and sensing capabilities. Nevertheless, most of the time these EVs spend their time in parking lots, which makes onboard devices cruelly underutilized. Thus, a better management and pooling these underutilized resources together would be strongly recommended. The new aggregated resources would be useful for traffic safety applications, comfort related applications or can be used as a distributed data center. Moreover, parked vehicles might also be used as a service delivery platform to serve users. Therefore, the use of aggregated abundant resources for the …

Autour de l’équation de Schrödinger non-linéaire dans les fibres optiques : similaritons, régénération, sources fibrées et évènements extrêmes

2009

Contrôle quantique optimal et robuste dans des systèmes de petite dimension

2020

Optimal control theory (OCT) is the basic and comprehensive method to obtain the optimal solutions of quantum systems controlled by external fields. It provides a powerful set of tools and concepts. One of the goals of the thesis is to design the technique of OCT in two- and three-state quantum systems taking into account losses and robustness, which is of primary importance for the implementation of control techniques in a broad class of platforms.Based on inverse-engineering techniques and the Pontryagin maximum principle (PMP), we establish and test the different optimal strategies showing how to control the transfer in three-level quantum systems considering energy- and time-minimum opt…

Estimation de la densité de la mesure spectrale mixte pour un processus symétrique stable strictement stationnaire

1994

International audience

Dynamique et assemblage des communautés adventices : Approche par modélisation statistique

2011

To develop solutions for a productive and sustainable agriculture, principles, theories, andmethods of ecology may contribute to understand the biological processes governing the agroecosystem.The present case study was based on data collected by a network of observatories of weeds covering the whole of France (‘Biovigilance Flore’) and aimed at establishing forrules governing the assemblage and dynamics of weed communities in fields grown with annual crops. We particularly studied the possible relationships between species within acommunity, as well as the relationships between communities and their environment. Analyses were based on species abundances to take account of their effect on c…