Pratiques nouvelles en conception industrielle: adaptation des acteurs, des objets médiateurs et des modalités de travail.

Une intervention in situ de deux mois au sein d’une équipe de conception de produits industriels (designers, dessinateurs), construite sur les méthodologies et théories de l’approche ergonomique « compréhensive », interroge les pratiques nouvelles de ces métiers depuis l’avènement de la CAO. Les « objets médiateurs » sont considérés selon leurs apports respectifs et complémentaires et non plus selon une approche dichotomique, et leur étude structure l’ensemble du recueil des données. Une méthodologie de traitement et d’analyse des informations récoltées est présentée (approche chronologique et analyses « verticales » sur base de lignes du temps). Celle-ci nous permet de tracer les nombreuses adaptations dont font preuve les acteurs tout au long de leur processus: adaptations de leurs outils et représentations, de leurs modalités de travail individuelles ou collaboratives, adaptations et développement de nouvelles compétences

A Thermal Plume Model for the Martian Convective Boundary Layer

The Martian Planetary Boundary Layer [PBL] is a crucial component of the Martian climate system. Global Climate Models [GCMs] and Mesoscale Models [MMs] lack the resolution to predict PBL mixing which is therefore parameterized. Here we propose to adapt the "thermal plume" model, recently developed for Earth climate modeling, to Martian GCMs, MMs, and single-column models. The aim of this physically-based parameterization is to represent the effect of organized turbulent structures (updrafts and downdrafts) on the daytime PBL transport, as it is resolved in Large-Eddy Simulations [LESs]. We find that the terrestrial thermal plume model needs to be modified to satisfyingly account for deep turbulent plumes found in the Martian convective PBL. Our Martian thermal plume model qualitatively and quantitatively reproduces the thermal structure of the daytime PBL on Mars: superadiabatic near-surface layer, mixing layer, and overshoot region at PBL top. This model is coupled to surface layer parameterizations taking into account stability and turbulent gustiness to calculate surface-atmosphere fluxes. Those new parameterizations for the surface and mixed layers are validated against near-surface lander measurements. Using a thermal plume model moreover enables a first order estimation of key turbulent quantities (e.g. PBL height, convective plume velocity) in Martian GCMs and MMs without having to run costly LESs.Comment: 53 pages, 21 figures, paper + appendix. Accepted for publication in Journal of Geophysical Research - Planet

Two-dimensional flows of foam: drag exerted on circular obstacles and dissipation

A Stokes experiment for foams is proposed. It consists in a two-dimensional flow of a foam, confined between a water subphase and a top plate, around a fixed circular obstacle. We present systematic measurements of the drag exerted by the flowing foam on the obstacle, \emph{versus} various separately controlled parameters: flow rate, bubble volume, solution viscosity, obstacle size and boundary conditions. We separate the drag into two contributions, an elastic one (yield drag) at vanishing flow rate, and a fluid one (viscous coefficient) increasing with flow rate. We quantify the influence of each control parameter on the drag. The results exhibit in particular a power-law dependence of the drag as a function of the solution viscosity and the flow rate with two different exponents. Moreover, we show that the drag decreases with bubble size, increases with obstacle size, and that the effect of boundary conditions is small. Measurements of the streamwise pressure gradient, associated to the dissipation along the flow of foam, are also presented: they show no dependence on the presence of an obstacle, and pressure gradient depends on flow rate, bubble volume and solution viscosity with three independent power laws.Comment: 23 pages, 13 figures, proceeding of Eufoam 2004 conferenc

Trilobite faunal dynamics on the Devonian continental shelves of the Ardenne Massif and Boulonnais (France, Belgium)

During the Devonian the sedimentation on the continental shelves of Ardenne Massif and Boulonnais has changed from a mixed siliciclastic-carbonate ramp (Eifelian), through a carbonate barrier reef (Givetian) and then to a detritic influx with local mud-mounds (Frasnian). Here we analysed the faunistic dynamics of the trilobite associations through the changing environment. We used multivariate analyses (clustering and ordering) to discriminate the trilobite associations within 67 different samples. Three previously known communities and one new were recognised: the Eifelian Mixed association, the Givetian Dechenella association and the two Frasnian Bradocryphaeus and Scutellum-Goldius associations. These trilobite faunas present a progressive ecological specialisation. The Mixed association occurs both in the ramp or carbonated (local reef developed on the ramp) facies without any significant difference in its composition. The Dechenella fauna occurs preferentially close to barrier reefs, but can also survive during short periods of detrital input. The two Frasnian communities show a strong relationship with their environment. The Scutellum-Goldius association is only found in reef systems, whereas the Bradocryphaeus flourishes exclusively in lateral facies.Fil: Bignon, Arnaud Marcel Jacques. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Crônier, Catherine. Universite Lille 3; Franci

Influence of experimental conditions on sound pleasantness evaluations

ICA 2016, 22nd International Congress on Acoustics, BUENOS AIRES, ARGENTINE, 05-/09/2016 - 09/09/2016Being able to characterize and estimate the urban sound perception is a key point to improve the city dwellers environmental quality. In the past decade, various studies have focused on collecting perceived global sound pleasantness at specific locations. Some of them were carried out on field in order to evaluate the soundscape perception of the participants directly in their context. Other studies were realized in laboratory to better control the stimuli and to increase the number of participants who were subjected to the same sound environment. Most of the laboratory experiments are done in large or semi-anechoic chamber with calibrated and highly realistic audio reproduction in order to respect the ecological validity of the experiment. On one hand, even with a high immersive level, the laboratory context is not as rich as the field context and the two types of experiment could lead to different results. On the other hand, few studies exist showing the influence of decreasing ecological validity for the same experience. This work presents a short statistical analysis of perceptive evaluations of ten urban locations under 4 different test conditions. First, evaluations are carried out directly in-situ in the city of Paris. Then audio-visual recordings of these locations are evaluated in three different experimental conditions: (i) in a well-controlled acoustic laboratory in Paris region with French people, (ii) in an acoustic laboratory in Buenos Aires with Argentinean participants and lowest immersive conditions, (iii) in a habitational room with Argentinean participants and subjective calibration. The study reveals that both the 'country' factor and the experimental conditions in laboratory do not show any significant impact on the perceived sound pleasantness and perceived loudness assessments

Data mining on urban sound sensor networks

ICA 2016, 22nd International Congress on Acoustics, BUENOS AIRES, ARGENTINE, 05-/09/2016 - 09/09/2016Urban sound sensor networks deliver megabytes of data on a daily basis so the question on how to extract useful knowledge from this overwhelming dataset is eminent. This paper presents and compares two extremely different approaches. The first approach uses as much as possible expert knowledge on how people perceive the sonic environment, the second approach simply considers the spectra obtained every time step as meaningless numbers yet tries to structure them in a meaningful way. The approach based on expert knowledge starts by extracting features that a human listener might use to detect salient sounds and to recognize these sounds. These features are then fed to a recurrent neural network that learns in an unsupervised way to structure and group these features based on co-occurrence and typical sequences. The network is constructed to mimic human auditory processing and includes inhibition and adaptation processes. The outcome of this network is the activation of a set of several hundred neurons. The second approach collects a sequence of one minute of sound spectra (1/8 second time step) and summarizes it using Gaussian mixture models in the frequency-amplitude space. Mean and standard deviation of the set of Gaussians are used for further analysis. In both cases, the outcome is clustered to analyze similarities over space and time as well as to detect outliers. Both approaches are applied on a dataset obtained from 25 measurement nodes during approximately one and a half year in Paris, France. Although the approach based on human listening models is expected to be much more precise when it comes to analyzing and clustering soundscapes, it is also much slower than the blind data analysis

Mon/notre/leur corps est toujours un champ de bataille : Discours féministes et queers libertaires au Québec, 2000-2007

Les auteures se livrent à une analyse des discours produits et diffusés par des groupes et des personnes qui luttent contre le patriarcat et l’hétérosexisme en priorité et qui semblent avoir une certaine culture libertaire. Une lecture des zines, des brochures, des journaux, des compilations vidéo/DVD, des albums de musique et des sites Web leur a permis de mettre en évidence trois tendances : la première regroupe les féministes radicales, clairement en continuité avec la génération politique précédente; la deuxième tendance s’apparente au women-of-color feminism; et la troisième est représentée par des groupes queers radicaux qui, tout en tentant de déconstruire l’identité sexuelle femme, invente un militantisme de multiples identifications.In this article we share an analysis of the discourse produced and distributed by groups and individuals struggling against patriarchy and heterosexism who share an anti-authoritarian analysis and organisational form. Out of our reading of zines, brochures, newspapers, video/DVD compilations, music albums and Internet sites, have emerged three trends: the first produced by materialist feminists that is clearly in continuity with the previous political generation, the second that relates to women-of-color feminism and a third, produced by radical queer groups, who attempt to deconstruct woman as a sexual identity and to invent a politics of multiple identification

Thezoo: un thesaurus de zoologie ancienne et médiévale pour l’annotation de sources de données hétérogènes

International audienceThis paper presents a thesaurus of ancient and medieval zoological knowledge, called THEZOO, constructed in the framework of the International Research Group Zoomathia. It aims at integrating heterogeneous data sources on zoology in Antiquity and Middle Ages: mainly texts, but also images, archaeological objects and archaeozoological material. The development process of THEZOO combines 1) the manual annotation of books VIII-XI of Pliny the Elder’s Natural History, chosen as a reference dataset to elicit the concepts to be integrated in the thesaurus, and 2) the definition and hierarchical organization of the elicited concepts in the thesaurus. THEZOO is formalized in SKOS, the W3C standard to represent knowledge organization systems on the Web of data, and it is created with the Opentheso editor. Our final aim is to publish the thesaurus THEZOO as well as the corpus of annotated texts, to support a semantic search in the corpus in different languages