Adsorption of a binary mixture of monomers with nearest-neighbour cooperative effects

A model for the adsorption of a binary mixture on a one-dimensional infinite lattice with nearest neighbour cooperative effects is considered. The particles of the two species are both monomers but differ in the repulsive interaction experienced by them when trying to adsorb. An exact expression for the coverage of the lattice is derived. In the jamming limit, it is a monotonic function of the ratio between the attempt frequencies of the two species, varying between the values corresponding to each of the two single species. This is in contrast with the results obtained in other models for the adsorption of particles of different sizes. The structure of the jamming state is also investigated.Comment: v2: Errors in the figures fixed; same text; 23 pages, 5 figures. Accepted for publication in Journal of Physics A: Mathematical and Genera

Enhancement of ferromagnetism by nickel doping in the 112 cobaltite EuBaCo2O5.50

The study of the ordered oxygen deficient perovskite EuBaCo2-xNixO5.50 shows that the doping of cobalt sites by nickel induces a strong ferromagnetic component at low temperature in the antiferromagnetic matrix of EuBaCo2O5.50. This system exhibits indeed phase separation, i.e. consists of ferromagnetic domains embedded in the antiferromagnetic matrix of EuBaCo2O5.50. Besides, a magnetic transition is observed for the first time at 40K in the undoped and nickel doped phases, which can be attributed to the ferromagnetic ordering of the Eu3+ moments below this temperature. Moreover sharp ultra magnetization multisteps are observed below 5K, characteristic of motion of domain walls in a strong pinning system and very different from any metamagnetic transition

Developing a Relationship Between LIBS Spectra and Pit Volume for in Situ Dating of Geologic Samples

No abstract availabl

Modeling the martian atmosphere with the LMD global climate model

Introduction: For several years we have been developing a 3D Global Climate Model (GCM) for Mars derived from the models used on Earth for weather forecasting or climate changes studies [1]. The purpose of such a project is ambitious: we wish to build a 'Mars simulator' based only on physical equations, with no tailor-made forcing, but able to reproduce all the available observations of the Martian climate (temperatures, winds, but also clouds, dust, ices, chemical species, etc...). The GCM is constantly evolving, thanks to a contnuous collaboration between several teams based in France (LMD, SA), the UK (The Open University, University of Oxford) and Spain (Instituto de Astrofisica de Andalucia), and with the support of ESA and CNES. We are currently working on an improved version of the model. Several new parametrisation are included in the heart of the model (radiative transfer, surface and subsurface processes, dynamics) and the applications of the GCM are in contnuous development (Water, dust, CO2, radon cycles, photochemistry, thermosphere, ionosphere, etc...

Relationship Between LIBS Ablation and Pit Volume for Geologic Samples: Applications for the In Situ Absolute Geochronology

These first results demonstrate that LIBS spectra can be an interesting tool to estimate the ablated volume. When the ablated volume is bigger than 9.10(exp 6) cubic micrometers, this method has less than 10% of uncertainties. Far enough to be directly implemented in the KArLE experiment protocol. Nevertheless, depending on the samples and their mean grain size, the difficulty to have homogeneous spectra will increase with the ablated volume. Several K-Ar dating studies based on this approach will be implemented. After that, the results will be shown and discussed

Mars Climate Database version 5

The Mars Climate Database (MCD) is a database of meteorological fields derived from General Circulation Model (GCM) numerical simulations [2,4] of the Martian atmosphere and validated using available observational data. The MCD includes complementary post-processing schemes such as high spatial resolution interpolation of environmental data and means of reconstructing the variability thereof. The GCM is developed at LMD (Laboratoire de Météorologie Dynamique, Paris, France) in collaboration with several teams in Europe: LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales, Paris, France), the Open University (UK), the Oxford University (UK) and the Instituto de Astrofisica de Andalucia (Spain) with support from the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES). The MCD is freely distributed and intended to be useful and used in the framework of engineering applications as well as in the context of scientific studies which require accurate knowledge of the state of the Martian atmosphere. The Mars Climate Database (MCD) has over the years been distributed to more than 150 teams around the world. With the many improvements implemented in the GCM over the last few years, a new series of reference simulations have been run and compiled in a new version (version 5) of the Mars Climate Database, released in the first half of 2012

Multiagent system for data fusion in image processing

The data fusion of results in image processing poses many problems of modelling and representation of knowledge, among whic h one can mention : o the difficulty to define, exhaustively, the conditions of utilization of processings in function of the context , the difficulty to evaluate the results of processings , . the difficulty to elaborate strategies making cooperate several processings or merging results . The system ADAGAR (Atelier of Development of AGents on Distributed Architecture) proposes solutions to these problems . ADAGAR results from elaborated concepts in the project BBI (BlackBoard Image) . The aim of the project BBI was to conceive on a multi–processors architecture, a perceptive system of interpretation of images issued from different sources . The idea was not to elaborate new operators of image processing , but to develop a reception structure of existent processing . One of the particularities of the system lies in the expression of a priori valuation knowledge (scores of aptitude) . The formalizatio n of these knowledge is inspired of the theory of Dempster–Shafer. The formalism allows to represent the ignorance on condition s of activation of a processing in a particular context . The prototype BBI contains currently a thirty of agents . It functions on couples of aerial or satellitaire images in the visible and th e infrared spectra or in the visible and the radar spectra . BBI elaborates dynamically one or several strategies of research, from th e specificities of the processed images and objects to detect . The cooperations between processings at the low level, the information fusion and the focus of attention at the symbolic level are the main reasons of the good functioning of the prototype .La fusion des résultats en analyse d'images pose de nombreux problèmes de modélisation et de représentation des connaissances parmi lesquels, on peut mentionner: . la difficulté de définir exhaustivement les conditions d'utilisation des traitements en fonction du contexte, . la difficulté d'évaluer les résultats des traitements, . la difficulté d'élaborer des stratégies faisant coopérer plusieurs traitements ou fusionnant des résultats. Le système ADAGAR (Atelier de Développement d'AGents sur Architecture Répartie) propose des solutions à ces problèmes. ADAGAR résulte de concepts élaborés dans le projet BBI (BlackBoard Image). L'objectif du projet BBI était de concevoir sur une architecture multi-processeurs, un système perceptif d'interprétation d'images issues de sources différentes. L'idée n'était pas d'élaborer de nouveaux opérateurs de traitements d'images, mais de développer une structure d'accueil des traitements existants. Une des particularités du système réside dans l'expression de connaissances d'estimation a priori (scores d'aptitude). La formalisation de ces connaissances est inspirée de la théorie de Dempster-Shafer. Le formalisme employé permet de représenter l'ignorance sur les conditions d'activation d'un traitement dans un contexte particulier. Le prototype BBI contient actuellement une trentaine d'agents. Il fonctionne sur des couples d'images aériennes ou satellitaires dans les spectres visible/infrarouge et visible/radar. BBI élabore dynamiquement une ou plusieurs stratégies de recherche, à partir des spécificités des images traitées et des objets à détecter. Les coopérations entre les traitements au bas niveau, les fusions d'informations et les focalisations d'attention au niveau symbolique sont les principales raisons du bon fonctionnement du prototype. Intelligence artificielle distribuée, Système multi-agents, Système réparti, Interprétation d'images

Individual and collective stock dynamics: intra-day seasonalities

We establish several new stylised facts concerning the intra-day seasonalities of stock dynamics. Beyond the well known U-shaped pattern of the volatility, we find that the average correlation between stocks increases throughout the day, leading to a smaller relative dispersion between stocks. Somewhat paradoxically, the kurtosis (a measure of volatility surprises) reaches a minimum at the open of the market, when the volatility is at its peak. We confirm that the dispersion kurtosis is a markedly decreasing function of the index return. This means that during large market swings, the idiosyncratic component of the stock dynamics becomes sub-dominant. In a nutshell, early hours of trading are dominated by idiosyncratic or sector specific effects with little surprises, whereas the influence of the market factor increases throughout the day, and surprises become more frequent.Comment: 9 pages, 7 figure