Associative Embedding for Game-Agnostic Team Discrimination

Assigning team labels to players in a sport game is not a trivial task when no prior is known about the visual appearance of each team. Our work builds on a Convolutional Neural Network (CNN) to learn a descriptor, namely a pixel-wise embedding vector, that is similar for pixels depicting players from the same team, and dissimilar when pixels correspond to distinct teams. The advantage of this idea is that no per-game learning is needed, allowing efficient team discrimination as soon as the game starts. In principle, the approach follows the associative embedding framework introduced in arXiv:1611.05424 to differentiate instances of objects. Our work is however different in that it derives the embeddings from a lightweight segmentation network and, more fundamentally, because it considers the assignment of the same embedding to unconnected pixels, as required by pixels of distinct players from the same team. Excellent results, both in terms of team labelling accuracy and generalization to new games/arenas, have been achieved on panoramic views of a large variety of basketball games involving players interactions and occlusions. This makes our method a good candidate to integrate team separation in many CNN-based sport analytics pipelines.Comment: Published in CVPR 2019 workshop Computer Vision in Sports, under the name "Associative Embedding for Team Discrimination" (http://openaccess.thecvf.com/content_CVPRW_2019/html/CVSports/Istasse_Associative_Embedding_for_Team_Discrimination_CVPRW_2019_paper.html

Tom-based tools to transform EMF models in avionics context

International audienceModel Driven Engineering (MDE) is now widely used in many industrial contexts (such as AeroSpace) which require a high level of system safety. Model-checking is one of the formal techniques which are used to assess a system compliance to its requirements. It relies on verification dedicated languages to model the system under verification and the expected properties. In order to ease the use of these tools, model transformations are provided that translate the end user provided system model to the formal languages than can be verified. In order to rely on these activities for system certification, the correctness of these transformation steps must be assessed (qualification of the development and verification tools). One of the goal of our work is to provide tools to implement the transformation steps between end user source languages used for the system development and target languages used for formal verification. This paper present the {Tom} rule-based approach used in a research project involving industrial partners: Airbus and Ellidiss

Fast acoustic streaming in standing waves : Generation of an additional outer streaming cell

Rayleigh streaming in a cylindrical acoustic standing waveguide is studied both experimentally and numerically for nonlinear Reynolds numbers from 1 to 30. Streaming velocity is measured by means of laser Doppler velocimetry in a cylindrical resonator filled with air at atmospheric pressure at high intensity sound levels. The compressible Navier-Stokes equations are solved numerically with high resolution finite difference schemes. The resonator is excited by shaking it along the axis at imposed frequency. Results of measurements and of numerical calculation are compared with results given in the literature and with each other. As expected, the axial streaming velocity measured and calculated agrees reasonably well with the slow streaming theory for small ReNL but deviates significantly from such predictions for fast streaming (ReNL > 1). Both experimental and numerical results show that when ReNL is increased, the center of the outer streaming cells are pushed toward the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes

Herbovore livestock farming systems and climatic changes in France: conclusions from a series of studies from 2006 to 2009 (THE ACTA/MIRES PROJECT)

Four partners are involved in the ACTA project called “Study of the sensitiveness to climatic changes of the large scale farms and herbivore livestock farming systems”; these are Arvalis, Inra (national institute for agronomic research), the French Livestock Institute and Meteo France. As part of this programme, simulations based on the STICS farming model were achieved in order to estimate consequences of climatic changes on biomass production of lucerne, corn and grasses. Mid-term (2020- 2049) and long-term (2070-2099) basic climatic data to implement such simulations were transmitted by Meteo France according to two socio-demographic scenari (A2 and B1) provided by the 4th report of the GIEC 4 group (government experts). Those simulations include the CO2 enrichment effect of atmosphere on photosynthesis and transpiration. Moreover, through the calculation of numerous agro-climatic indicators, we looked into the availability and accessibility to those fodder resources and into the frequency of some climatic risks. Leaning on livestock systems having features of rather different areas regarding the extent and the impact of climatic change, we took into consideration direct consequences of climatic change on fodder farming achieved in those systems, in order to explore the evolution of those particular systems’ balances and to evaluate adapting ways enabling to come back to satisfying and secure balances. These works underline adaptability of those systems to have production levels steady in a near future but put forward less favorable breaking downs in a distant future.Dans le cadre du projet ACTA « Étude de la sensibilité des systèmes de grandes cultures et d’élevages herbivores aux changements climatiques », associant quatre partenaires : ARVALIS, l’INRA, l’Institut de l’Élevage et Météo France, et à partir des données climatiques simulées par Météo-France à moyen (2020-2049) et long terme (2070-2099) selon deux scénarios socio-démographiques (A2 et B1) issus du 4ème rapport du Groupe d’experts intergouvernemental (GIEC 4), des simulations utilisant le modèle de culture STICS (Simulateur multidisciplinaire pour les cultures standard) ont été réalisées pour évaluer les conséquences du changement climatique sur la production de biomasse de la luzerne, du maïs et de prairies à base de graminées. Ces simulations intègrent l’effet de l’enrichissement de l’atmosphère en CO2 sur la photosynthèse et la transpiration. Par ailleurs, au travers du calcul de nombreux indicateurs agro-climatiques, l’étude s’est penchée sur la disponibilité et l’accessibilité à ces ressources fourragères, et sur la fréquence de certains aléas climatiques. En prenant appui sur des systèmes d’élevage caractéristiques de zones bien différentes quant à l’ampleur et l’impact du changement climatique, les conséquences directes du changement climatique sur les cultures fourragères pratiquées dans ces systèmes ont été intégrées afin d’explorer l’évolution des équilibres propres à ces systèmes et évaluer les voies d’adaptation permettant de revenir à des équilibres satisfaisants et sécurisés. Ces travaux soulignent les capacités adaptatives de ces systèmes à maintenir leurs niveaux de production dans le futur proche mais ils mettent en avant des ruptures moins favorables à plus long terme

La capacité d’absorption, l’élément clé dans la compréhension de la relation entre information et innovation : Le cas des PME du Congo-Brazzaville

Plusieurs études rappellent que l’innovation dans les PME s’explique avant tout par l’apport systématique de l’information le plus souvent informelle provenant notamment des clients, des fournisseurs, des concurrents et de diverses sources plus formelles comme les revues d’affaires ou les foires industrielles. On peut toutefois favoriser celle-ci par une meilleure capacité de ces organisations à cibler et à transformer l’information en connaissance, en particulier en organisant mieux la veille et en améliorant la capacité d’absorption et de transformation de l’information.Dans une enquête exploratoire effectuée auprès d’une quarantaine de PME de trois secteurs industriels au Congo-Brazzaville et en tenant compte des caractéristiques d’un pays en développement, nous montrons que la relation entre les sources d’information, la capacité d’absorption et l’innovation joue autant que dans les pays industrialisés. En particulier, le niveau de formation de la direction et de quelques employés clefs semble constituer la variable la plus importante pour expliquer cette relation.Several studies point out that innovation in SMEs is explained primarily by providing systematic information, mostly informal, from customers, suppliers, competitors and various other more formal sources such as business magazines or industrial fairs. However, one may favour innovation through an improved capacity to target and transform information into knowledge, especially in regard to business intelligence gathering, and by improving the capacity to absorb and process information.In an exploratory survey conducted among forty SMEs in three industrial sectors in Congo-Brazzaville, and taking into account the characteristics of a developing country, we show that the relationship between sources of information, absorptive capacity and innovation is as strong as in industrialized countries. In particular, the training level of management and key employees appears to be the most important variable to explain this relationship.Varios estudios señalan que la innovación en las PyMEs se explica principalmente por el suministro de información sistemática en su mayoría informal, procediendo de clientes, proveedores, competidores y varias fuentes más oficiales, como las revistas de negocios o ferias industriales. Sin embargo, podemos promover a través de una mayor capacidad de estas organizaciones para seleccionar y transformar información en conocimiento, especialmente en la organización mejor de vigilia, y por la mejora de la absorción y procesamiento de información.En una encuesta exploratoria realizada entre los cuarenta PyMEs de tres sectores industriales en Congo-Brazzaville, y teniendo en cuenta las características de un país en desarrollo, mostramos que la relación entre las fuentes de información, la capacidad de la absorción y la innovación es tanto como en los países industrializados. En particular, el nivel de formación de gestión y de algunos empleados clave parece ser la variable más importante para explicar esta relación.Mehrere Studien weisen darauf hin, dass Innovationen in KMU in erster Linie durch den systematischen Zufluss von Informationen aus informellen Quellen (Kunden, Lieferanten, Konkurrenten) sowie von Informationen formelleren Ursprungs (Fachmagazine, industrielle Messen) erklärbar sind. Der informative Nutzen zeigt sich bei den Unternehmen in einer verbesserten Kapazität, die relevanten Informationen zu filtern und in Wissen umzuwandeln und vor allem in einer gesteigerten Fähigkeit Informationen zu absorbieren und zu überwachen.In einer explorativen Studie bei rund 40 KMU aus drei Industriesektoren im Kongo-Brazzaville und unter Berücksichtigung der Eigenheiten eines Entwicklungslandes, konnte aufgezeigt werden, dass der Zusammenhang zwischen Informationsquellen, Absorptionsfähigkeit und Innovation, genauso wie in Industrieländern, eine Rolle spielt. Die Ausbildung des Managements sowie diejenige einiger Schlüsselmitarbeiter scheint dabei in diesem Zusammenspiel eine besondere Rolle zu spielen

Growth and metal uptake of microalgae produced using salt groundwaters from the Bay of Bourgneuf

International audienceThe Bay of Bourgneuf, France, is a main site of shellfish production. In the marshes along the bay, oyster intensive rearing and fattening need the mass production of microalgae. Salt groundwaters, available in this region, support a large part of this production for aquaculture. Studies carried out by local authorities have brought to the fore the accumulation of lead (Pb) in several samples of algal pastes derived from cultures using salt groundwater. The aim of this study was to compare growth, nutritional value and metal (Cd, Cu, Pb and Zn) uptake of four microalgae grown in two salt groundwaters or in enriched coastal seawater. Cultures of microalgae used in aquaculture (Haslea ostrearia, Phaeodactylum tricornutum, Skeletonema costatum and Tetraselmis suecica) were realised at the laboratory under controlled experimental conditions. Results indicated that salt groundwaters provided cultures with, at least, an equal biomass and a nutritional value similar to cultures grown in enriched seawater. There was no difference regarding metal accumulation whatever the culture medium, except when S. costatum was grown in one of the salt groundwater in which case its cadmium levels were higher and could be above the French guideline level. These observations questioned on the bioavailability of metals in salt groundwaters. It also underlines the specificity of metal uptake and accumulation by microalgae

A general algebraic algorithm for blind extraction of one source in a MIMO convolutive mixture

International audienceThe paper deals with the problem of blind source extraction from a MIMO convolutive mixture. We define a new criterion for source extraction which uses higher-order contrast functions based on so called reference signals. It generalizes existing reference-based contrasts. In order to optimize the new criterion, we propose a general algebraic algorithm based on best rank-1 tensor approximation. Computer simulations illustrate the good behavior and the interest of our algorithm in comparison with other approaches

Measuring fish activities as additional environmental data during a hydrographic survey with a multi-beam echo sounder

International audienceThe modern multi-beam echo sounders (MBES) are advanced instrumentation for active underwater acoustic surveys that can be boarded on oceanic vessels as well on light crafts. Although their versatility allows scientists to perform various environmental studies, their potential is seldom fully exploited. A single data acquisition cruise is not only able to display the seabed backscatter, but also provide an estimation of the fish activities from an underwater site thanks to water column imagery. This work is aiming at developing some (automatic) signal processing techniques to detect, analyse and classify objects observed in the water column with a focus on fish activities to provide fish accumulation and classification but also some comparative analyses along with the seafloor classification

Diagonalisation conjointe de tenseurs d'ordre 3 Application à la séparation de signaux non-circulaires

On considère la diagonalisation conjointe de tenseurs complexes d'ordre trois symétriques. Nous proposons un algorithme de type Jacobi pour la réaliser et la solution optimale dans le cas 2 × 2 est donnée. Nous illustrons le lien entre cette décomposition conjointe et la séparation de sources non circulaires par l'intermédiaire d'une fonction de contraste. Des simulations illustrent l'approche proposée

Pressure drop and axial dispersion in industrial millistructured heat exchange reactors

Hydrodynamic characterization by means of pressure drop and residence time distribution (RTD)experiments is performed in three millistructured heat exchange reactors: two Corning reactors (further referred to as Corning HP and Corning RT) and a Chart reactor. Pressure drop is measured for different flow rates and fluids. Fanning friction factor is then calculated and its evolution versus Reynolds number is plotted for each reactor, showing the influence of the geometrical characteristics of the reactors on this parameter. From RTD experiments, axial dispersion coefficients that allow calculating Péclet numbers are identified by solving the convection-dispersion equation. The results highlight plug flow behavior of these reactors for the range of flow rates studied. Péclet number in Corning HP remains constant in the range of Reynolds number studied. Its specific pattern is designed to generate mixing structures that allow homogenization of the tracer over the cross-section. It explains the plug flow behaviour of this reactor even at low Reynolds number but generates high pressure drop. Péclet number in Corning RT and Chart ShimTec1 increases with Reynolds number. This evolution is encountered for straight circular pipes in turbulent regime and confirms the pressure drop analysis