ÉLEMENTS D'INGENIERIE DE LOGICIELS EDUCATIFS, LE CAS DES MICROMONDES POUR LES MATHEMATIQUES : DIMENSION INFORMATIQUE

This text takes up and continues the presentation of a research and development study already partially published. The design principles are based on didactic computer engineering in which we are particularly interested in the initial part of the preliminary analyzes in their epistemological, cognitive, didactic and computacional dimensions. These preliminary analyzes provide an in-depth study of knowledge and its teaching and learning, which makes Informatics didactic transposition operational. In this text, we more specifically address the computer dimension of the preliminary analyzes to outline a modeling of a generic microworld offering support for the exploration and resolution of problems requiring the articulation between various registers of representation, and finally to outline the structures of data. The objective of this work is not only to advance on the specifications and their modeling, but also, in reverse engineering, to promote the technological transfer of microworlds already developed.Ce texte reprend, en la poursuivant, la présentation d’une étude de recherche et développement déjà partiellement publiée. Les principes de conception s’appuient sur l’ingénierie didactique informatique dans laquelle nous nous intéressons plus particulièrement à la partie initiale des analyses préalables dans leurs dimensions épistémologique, cognitive, didactique et informatique. Ces analyses préalables fournissent une étude approfondie du savoir et de son enseignement et apprentissage qui rend opérationnelle la transposition didactique informatique. Dans ce texte, nous abordons plus spécifiquement la dimension informatique des analyses préalable pour ébaucher une modélisation d’un micromonde générique offrant un support à l’exploration et résolution de problèmes nécessitant l’articulation entre divers registres de représentation, et finalement ébaucher des structures de données. L’objectif de ce travail n’est pas seulement d’avancer sur les spécifications et leur modélisation, mais aussi, dans une ingénierie reverse, de favoriser le transfert technologique de micromonde déjà développés

The dynamic evolutionary history of the bananaquit (Coereba flaveola) in the Caribbean revealed by a multigene analysis

<p>Abstract</p> <p>Background</p> <p>The bananaquit (<it>Coereba flaveola</it>) is a small nectivorous and frugivorous emberizine bird (order Passeriformes) that is an abundant resident throughout the Caribbean region. We used multi-gene analyses to investigate the evolutionary history of this species throughout its distribution in the West Indies and in South and Middle America. We sequenced six mitochondrial genes (3744 base pairs) and three nuclear genes (2049 base pairs) for forty-four bananaquits and three outgroup species. We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range expansion.</p> <p>Results</p> <p>Phylogenetic concordance between mitochondrial and nuclear genes at the base of the bananaquit phylogeny supported a West Indian origin for continental populations. Multi-gene analysis showing genetic remnants of successive colonization events in the Lesser Antilles reinforced earlier research demonstrating that bananaquits alternate periods of invasiveness and colonization with biogeographic quiescence. Although nuclear genes provided insufficient information at the tips of the tree to further evaluate relationships of closely allied but strongly supported mitochondrial DNA clades, the discrepancy between mitochondrial and nuclear data in the population of Dominican Republic suggested that the mitochondrial genome was recently acquired by introgression from Jamaica.</p> <p>Conclusion</p> <p>This study represents one of the most complete phylogeographic analyses of its kind and reveals three patterns that are not commonly appreciated in birds: (1) island to mainland colonization, (2) multiple expansion phases, and (3) mitochondrial genome replacement. The detail revealed by this analysis will guide evolutionary analyses of populations in archipelagos such as the West Indies, which include islands varying in size, age, and geological history. Our results suggest that multi-gene phylogenies will permit improved comparative analysis of the evolutionary histories of different lineages in the same geographical setting, which provide replicated "natural experiments" for testing evolutionary hypotheses.</p

Automatic method for spectral pattern association with characteristic frequencies

International audienceThis paper proposes an advanced signal-processing technique to improve the condition monitoring of rotating machinery. The proposed method employs the results of a blind spectrum interpretation including harmonic and sideband series detection. The contribution of this paper is an algorithm for automatic association of harmonic and sideband series with the characteristic fault frequencies listed in the kinematic configuration of the monitored system. The proposed algorithm is efficient in inspection of real-world signals, which contain a vast number of detected spectral components. The proposed approach has the advantage of taking into account a possible slip of the rolling-element bearings. The performance of the proposed algorithm is illustrated on real-world data by investigating a shaft problem of an industrial wind turbine high-speed shaft

ÉLEMENTS D'INGENIERIE DE LOGICIELS EDUCATIFS, LE CAS DES MICROMONDES POUR LES MATHEMATIQUES : DIMENSIONS EPISTEMOLOGIQUE, COGNITIVE ET DIDACTIQUE

Dans ce texte, nous proposons d’aborder la conception de micromondes informatiques pour l’enseignement et l’apprentissage des mathématiques. Les principes théoriques et méthodologiques misen œuvre pour cette conception sont puisés d’une part dans l’ingénierie didactique et d’autre part dans l’ingénierie de logiciels éducatifs. Parce que, pour la conception des micromondes, la représentation des connaissances mathématiques dans l’environnement computationnel est centrale, nous abordons la notion de transposition didactique informatique. Celle-ci est considérée pour ce qu’elle identifie, mais aussi comme outil au travers de sa mise en œuvre dans ses dimensions épistémologique, cognitive, didactique et informatique. Cette mise en œuvre nous permet de proposer les premiers éléments de description de fonctionnalités pour la conception et le développement de micromondes pour les mathématiques. Même s’il ne s’agit pas encore d’éléments permettant à un informaticien d’engager un développement effectif, il s’en approche

Online condition monitoring of wind turbines through three-phase electrical signature analysis

International audienceIn the context of the KAStrion European project, a complete solution was proposed in order to monitor wind turbines. The developed solution comprises both hardware and software parts of the condition monitoring system. In terms of software, modules for vibration analysis and electrical signal analysis have been developed. The current paper presents the electrical analysis solution proposed in the context of this project. The electrical module is able to detect both mechanical and electrical faults in a wind turbine system. The goal of the mechanical fault detection using electrical signals is to confirm the faults also detected by vibration analysis, while the main focus of the module remains the detection of electrical faults. Results showing the performance of mechanical fault detection are presented using electrical signals acquired on the test-bench developed for testing the KAStrion system. Moreover, results regarding the electrical unbalance are presented using signals acquired on a three-phase transformer. The final solution has been implemented on two onshore wind turbines since the end of 2014, and online condition monitoring results are presented at the end of the paper

Veterinary services in the European Union: Training of official veterinary surgeons (OVS)

The Veterinary services in the member states of the European Union follow common guidelines. However, their organisations, staff status and training policies are very different. They are briefly described and analysed, with a special focus on French choices.Les services vétérinaires des États membres de l'Union Européenne poursuivent des objectifs communs, dans le cadre du marché unique. Cependant, leurs organisations, statuts des personnels et politiques de formation sont extrêmement variables. Ceux-ci sont décrits et analysés schématiquement, puis les choix français sont soulignés

AStrion data validation of non-stationary wind turbine signals Topic: Condition monitoring (CM) methods and technologies

International audienceAStrion is an automatic spectrum analyzer software, which proposes a new generic and data-drivenmethod without any a priori information on the measured signals. In order to compute some generalcharacteristics and derive properties of the signal, the first step in this approach is to give some insightinto the nature of the signal. This preanalysis, so called the data validation, contains a number of tests toreveal some properties and characteristics of the data such as the acquisition validity (absence ofsaturation and a posteriori respect of the sampling theorem), the stationarity (or non-stationarity), theperiodicity and the signal-to-noise ratio. Based on these characteristics, the proposed method definesindicators and alarm trigger thresholds, also categorizes the signal into three classes which help to guidethe following spectral analysis. The present paper introduces the four tests of this preanalysis and thesignal categorization rules. Finally, the proposed approach is validated on a set of wind turbine vibrationmeasurements to demonstrate its applicability of a long-term and continuous monitoring on real-worldsignal

AStrion strategy: from acquisition to diagnosis. Application to wind turbine monitoring

International audienceThis paper proposes an automatic procedure for condition monitoring. It represents a valuable tool for maintenance of expensive and spread systems such as wind turbine farms. Thanks to data-driven signal processing algorithms, the proposed solution is fully automatic for the user. The paper briefly describes all the steps of the processing , from pre-processing of acquired signal to interpretation of generated results. It starts with an angular resampling method with speed measurement correction. Then comes a data validation step, in both time/angular and frequency/order domains. After these pre-processings, the spectral components of the analyzed signal are identified and classified in several classes from sine wave to narrow band components. This spectral peak detection and classification allows extracting the harmonic and side-band series which may be part of the signal spectral content. Moreover, the detected spectral patterns are associated with the characteristic frequencies of the investigated system. Based on the detected side-band series, the full-band demodulation is performed. At each step, the diagnosis features are computed and dynamically tracked signal by signal. Finally, system health indicators are proposed to conclude about the condition of the investigated system. All mentioned steps create a self-sufficient tool for robust diagnosis of mechanical faults. The paper presents the performance of the proposed method on real-world signals from a wind turbine drive train

Architecture des systèmes d'automatisation des postes résiliente aux attaques des trames GOOSE

National audienceNotre travail concerne la spécification et la mise en oeuvre d'un système d'automatisation des postes électriques conformes à la norme IEC 61850 capable de fonctionner en présence d'attaques sur les systèmes de communication temps-réel (communication GOOSE). Notre architecture repose sur trois concepts : la réalisation des sondes capables de détecter les attaques sur les trames GOOSE, la remontée des alertes au SCADA et la réalisation d'une commande des équipements de terrain intégrant l'information de cybersécurité

Compreender o trabalho do professor com os recursos de seu ensino, um questionamento didático e informático

A conferência é o resultado de um trabalho conjunto entre Franck Bellemain e Luc Trouche, que tem sua origem em uma antiga colaboração, mobilizando as equipes Edumatec no Brasil e EducTice na França. Um destaque foi a Escola de Altos Estudos da CAPES, realizada em fevereiro e março de 2015, em Recife (TROUCHE, 2015). Esta escola, desde então, tem fornecido material para novos recursos (ASSIS & LUCENA, 2015; LUCENA & ASSIS, 2015; BALTAR, 2016). A primeira parte da conferência (seções 1, 2 e 3) foi apresentada por Luc Trouche e Katiane Rocha; a segunda parte da conferência, na ausência de Franck Bellemain, justificada, foi coordenada por Verônica Gitirana e envolveu a participação de Cibele Assis, Rogério Ignácio, Ricardo Tibúrcio e Rosilângela Lucena