Élites lémovices : état des lieux de la documentation épigraphique et quelques études de cas

International audienceThis article deals with the connections between elites and territories. It is based on epigraphy in Limousin, France and includes three magistrates of the city of Lemovices and two priests of Confluent. The notion of "elite", though, goes beyond its usual political meaning and should include all the people having an eminent social position in local society.Cet article permet de réaliser un état des lieux des rapports entre élites et territoires à partir de la documentation épigraphique du Limousin. Ce corpus comporte trois magistrats de la cité des Lémovices et deux prêtres du Confluent. Cependant, le concept d’élite dépasse la seule définition politique et permet d’appréhender d’autres individus qui occupent une position éminente dans la société locale

Hydrogen embrittlement susceptibility of a high strength steel X80

The present paper deals with hydrogen embrittlement (HE) susceptibility of a high strength steel grade (X80). The respective implication of different hydrogen populations, i.e. adsorbed, dissolved in interstitial sites, trapped on dislocations and/or microstructural elements on the associated embrittlement mechanisms has been addressed through mechanical testing in high pressure of hydrogen gas at room temperature. Tensile tests at various strain rates and hydrogen pressures have been carried out. Moreover, changes of gas (hydrogen or nitrogen) during loading have been imposed in order to get critical experiments able to discriminate among the potential hydrogen embrittlement mechanisms already proposed in the literature. The results of these tests have shown that hydrogen induces several kind of damages including decohesion along ferrite/pearlite interfaces and microcracks initiations on the specimens external surface. It is shown that decohesion is not critical under the loading paths used in the present study. On the contrary, it appears that the external microcracks initiation, followed by a quasi-cleavage fracture, is responsible for the premature failure of the material in high pressure of hydrogen gas. These experimental results have been further discussed by modeling hydrogen diffusion in order to identify hydrogen populations (adsorbed, diffusible or trapped) involved in HE. It was then demonstrated that adsorbed and near surface diffusible hydrogen are mainly responsible for embrittlement

Dynamic measurements and wettability phenomena in mesoporous anodic films prepared on 1050 and 2024T3 aluminium alloys

The wettability of mesoporous anodic films has until now been a parameter rarely studied although it remains crucial especially for sealing treatment following anodising. Wettability measurement is in fact complex as it depends on a number of process parameters relating to the three phases (mesoporous anodic film, deposited liquid and ambient gas). In the present study, an innovative experimental approach was first adopted involving measuring the characteristics of a deposited water drop (contact angle, chord length and height of the drop) in relation to time. Following this, a flow balance allowed the amount of water having infiltrated the mesopores to be determined for two types of anodic film, one tortuous (on an AA 2024T3 substrate), the other not (on an AA 1050 substrate). On the basis of models already available in the literature, a phenomenological mechanism (spreading, penetration and evaporation) was finally proposed and discussed especially with respect to the tortuosity and prior drying of mesoporous anodic films

Some Economic Effects of The No-Interest Loan

A model is estimated using data from INSEEs 1996 Housing survey and 1997 Assets survey to measure the effect of the no-interest loan (NIL) on housing demand (this estimate concerns the effect of the NIL before the recent change in January 2005). The findings show that the no-interest loan definitely boosted home ownership and that this effect concerned mainly the most modest households among the homeowners. Most of these households have purportedly stayed, in the absence of assistance, in the dwelling they occupy until such time as they build the savings necessary for a down payment. However, the NIL suffers from substantial windfall effects. A full 85% of beneficiaries in a given period are reported to have chosen to move to become homeowners regardless of the absence of the no-interest loan. The NIL does necessarily contribute to the general improvement in the quality of new housing put on the market.Housing, Borrowing Constraints, Tenure Choice, Mobility, Homeownership

Finding optimal stimuli ensemble of a cortical network

We explore the determination of the optimal stimuli ensemble of a cortical network on the basis of numerical simulations of a local recurrent network. The optimal stimulus ensemble is determined with the Blahut-Arimoto algorithm using indices of population activity (multiunit activity and local field potentials). We show that the optimal stimulus ensemble is characterized by a distribution where the stimulus which induces a change in the dynamics of the network is highly represented. These results suggests that bifurcation points in the networks dynamic are highly informative and were in accordance with preliminary observation of electrophysiological recordings

Thermophilic bacterial communities in hot composts as revealed by most probable number counts and molecular (16S rDNA) methods

Thermogenic composts are known to host a variety of thermophilic micro-organisms that were recently investigated by cultural means and identified as Thermus thermophilus, Bacillus spp., and Hydrogenobacter spp. In this paper, we present a classical, cultural enumeration of thermophilic populations on the one hand, and a molecular investigation of the bacterial community by restriction enzyme analyses of a clone library of bacterial 16S rRNA genes on the other hand. Bacterial diversity, revealed by the clone analyses of four samples, was shown to undergo a dramatic change between the young (13-18-day) and the old (39-41-day) samples, possibly linked to the general decrease in temperature and the physicochemical evolution of organic matter during the composting process. Among the 200 clones investigated, 69 clones could be identified as Thermus thermophilus and thermophilic Bacillus spp. These results proved both taxa to be among the dominant bacterial populations at the highest temperatures reached by thermogenic compost

Clustering de visages : vers la construction automatique d'un album photo à partir d'une s equence vidé o

National audienceThis paper presents a clustering method of detections of the same object seen on a video. We apply it to the context of the automatic construction of photo album. We use a global analysis, based on a probabilistic framework of data association problems. The solution is given by Maximum A Posteriori estimation. Our main contribution concerns the use of a local front-back tracking, applied to each detection ; to increase appearance information of detections with a spatial information, through local tracks construction. We introduce a new likelihood measure based on the spatio-temporal dissimilarity between tracks. The algorithm is then able to deal with situations in which the face detections are scattered. We propose to use criteria derived from purity and inverse purity of a clustering to assess performances of the proposed method. This method is compared to hierarchical clustering on two real test sequences.Cet article présente une méthode de regroupement de détections d'un même objet vu sur une séquence vidéo, en se plaçant dans le cadre applicatif plus précis de la construction automatique d'un album photo. Nous utilisons une méthode d'analyse globale, basée sur une formalisation probabiliste du problème d'association de données. La solution du problème est alors donnée par une estimation du Maximum A Posteriori (MAP). La principale contribution concerne l'utilisation d'une méthode de suivi locale avant-arrière appliquée à chaque détection. Cela afin d'enrichir l'information d'apparence issue de la détection, par une information spatiale provenant de la construction de pistes locales. Nous introduisons une nouvelle mesure de vraisemblance basée sur la dissimilarité spatio-temporelle entre les pistes. L'algorithme obtenu est alors capable d'adresser des situations où les détections de visages sont éparses. Nous proposons d'utiliser des critères dérivés de la pureté et la pureté inverse d'un clustering pour évaluer les performances de la méthode proposée. La méthode est ensuite comparée à un clustering ascendant hiérarchique, sur deux séquences test réelles

Suivi de visages par regroupement de détections : traitement séquentiel par blocs

Session "Posters"National audienceCet article décrit une méthode de partitionnement des visages d'une séquence vidéo; elle se base sur une méthode de type tracking-by-detections et utilise une modélisation probabiliste de type Maximum A Posteriori, résolu par un algorithme s'appuyant sur une recherche de flot de coût minimal sur un graphe. Face aux contraintes de densité, mouvement et taille des détections de visage issues de la vidéosurveillance, les travaux présentés apportent deux contributions : (1) la définition de différentes dissimilarités (spatiale, temporelle, apparence et mouvement) combinées de façon simple et (2) la mise en œuvre d'une version séquentielle par blocs d'images qui permet de traiter des flux vidéos. La méthode proposée est évaluée sur plusieurs séquences réelles annotées