Recent advances in coherent optics. Filtering of spatial frequencies, holography

Applications of coherent light in areas of spatial filtering and holograph

Utilisation du bois de pin d'Alep (Pinus halepensis) : présentation d'un essai de transformation

Cet article présente un essai de transformation du pin d'Alep dont le but était d'observer le comportement du bois au sciage, au séchage et dans différentes utilisations en menuiserie. Globalement positif, cet essai nous montre que grâce à une sylviculture mieux adaptée et mieux maîtrisée et à un meilleur conditionnement lors des opérations de sciage et de séchage, cette essence composante incontournable de l'espace forestier méditerranéen peut être mieux valorisée

Recherche d'information et achat dans un environnement multi-canal. Le cas du "click and mortar"

abstractL'arrivée d'Internet introduit une situation inédite où les acheteurs sont susceptibles de disposer d'une quantité d'information très importante. Cette possibilité de comparer les offres semble même avoir redonné à certains consommateurs l'envie de mieux préparer certains de leurs achats. Un comportement "click and mortar" du consommateur peut ainsi être désigné, articulant à l'intérieur d'un même processus d'achat, une recherche d'information par Internet et une transaction en magasin traditionnel. Par l'intermédiaire de deux études empiriques, cette thèse analyse les antécédents et conséquences de ce comportement de recherche d'information pré-achat par Internet. La première étude souligne l'influence positive du besoin d'information, des motivations au shopping (principalement utilitaires) et des variables du modèle d'acceptation de la technologie (utilité perçue, facilité d'utilisation perçue et amusement lié à l'utilisation). De nature expérimentale, la seconde étude souligne les répercussions de la consultation d'Internet sur le comportement d'achat en magasin. Il ressort que le produit choisi est peu modifié (essentiellement en termes de marques), alors que le comportement adopté face au rayon est fortement réduit, traduisant un achat davantage planifié. Ces modifications s'expliquent de manière pertinente par l'articulation des modèles de persuasion et du comportement planifié

Utilisation d'un SIG pour la prévention et la lutte active. Assistance à la décision pour l'organisation et la gestion des ressources en eau.

Inventaire exhaustif des ressources hydrauliques utilisables dans la DFCI

On the equivalence of strong formulations for capacitated multi-level lot sizing problems with setup times

Several mixed integer programming formulations have been proposed for modeling capacitated multi-level lot sizing problems with setup times. These formulations include the so-called facility location formulation, the shortest route formulation, and the inventory and lot sizing formulation with (l,S) inequalities. In this paper, we demonstrate the equivalence of these formulations when the integrality requirement is relaxed for any subset of binary setup decision variables. This equivalence has significant implications for decomposition-based methods since same optimal solution values are obtained no matter which formulation is used. In particular, we discuss the relax-and-fix method, a decomposition-based heuristic used for the efficient solution of hard lot sizing problems. Computational tests allow us to compare the effectiveness of different formulations using benchmark problems. The choice of formulation directly affects the required computational effort, and our results therefore provide guidelines on choosing an effective formulation during the development of heuristic-based solution procedures

Multiplication des canaux et valeur perçue de l’offre digitale dans la presse écrite : un effet de complémentarité ?

As many sectors, the newspaper industry has been impacted by digital channels. This has fostered the emergence of new ways of accessing information and contributed to the development of new types of contents. The latest academic and managerial reflections lead to assume the existence of a complementarity effect between contents as well as between channels. This research aims to verify this hypothesis with a survey conducted among 1028 readers of the French newspaper Le Monde. The results validate only, and under condi- tions, a complementary effect between channels

L'information géographique au service de la forêt : définitions et enjeux.

Introduction et sommaire détaillé des travaux du groupe "Systèmes d information, informatique et forêt méditerranéenne" de Foresterranée 99

A computational analysis of lower bounds for big bucket production planning problems

In this paper, we analyze a variety of approaches to obtain lower bounds for multi-level production planning problems with big bucket capacities, i.e., problems in which multiple items compete for the same resources. We give an extensive survey of both known and new methods, and also establish relationships between some of these methods that, to our knowledge, have not been presented before. As will be highlighted, understanding the substructures of difficult problems provide crucial insights on why these problems are hard to solve, and this is addressed by a thorough analysis in the paper. We conclude with computational results on a variety of widely used test sets, and a discussion of future research

Methodological framework for an integrated multi-scale vulnerability and resilience assessment

The deliverable illustrates the methodological framework to assess vulnerability and resilience across different temporal and spatial scales, acknowledging the different domains where the latter may manifest, and in particular in the natural and the built environment, allocating a large importance to the so called “critical infrastructures”, in social and economic systems. A set of four matrices has been developed to identify what aspects should be looked at before the impact, that is to say what shows the potential ability or inability to cope with an extreme; at the impact, addressing in particular the capacity (or incapacity) to sustain various types of stresses (in the form of acceleration, pressure, heat…); in the time immediately after the impact, as the ability (or inability) to suffer losses and still continue functioning; and in the longer term of recovery, as the capacity to find a new state of equilibrium in which the fragilities manifested during and after the impact are addressed. Developing the framework, a particular attention has been paid to the relationships among systems within the same matrix and among matrices, across spatial and temporal scales. A set of matrices has been developed for different natural hazards, including in particular landslides and floods, trying to include as much as possible what past cases, the international literature and prior experience of involved partners have indicated as relevant parameters and factors to look at. In this regard, the project builds on the state of the art, embedding what has been learned until now in terms of response capacity to a variety of stresses and in the meantime identifying gaps to be addressed by future research