Scientific Publications of the University of Toulouse II Le Mirail
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An open-source closed-loop Virtual Reality system to investigate social interactions and collective behavior in fish
No full textCorrection: An open-source closed-loop Virtual Reality system to investigate social interactions and collective behavior in fishhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0343509International audienceAbstract This study introduces a low-cost, open source, immersive Virtual Reality (VR) system designed to investigate real-time social interactions and collective behaviors in fish. Understanding collective animal behaviors, such as schooling in fish, presents significant observational challenges due to rapid and complex interactions. To address these difficulties, we developed an innovative closed-loop VR environment allowing precise control and measurement of interactions between real and virtual fish. This setup incorporates high-speed 3D tracking, real-time visual feedback, and automated data processing, creating realistic and interactive scenarios. We present experimental results, obtained with Rummy-nose tetras ( Hemigrammus rhodostomus ), showing that freely moving real fish consistently adjusted their speed, depth, and spatial positioning to follow virtual fish effectively. Fish matched moderate virtual speeds comfortably, struggled slightly at higher speeds, and actively maintained vertical positioning to sustain group cohesion. Fish also displayed significant environmental awareness, adjusting their proximity to the tank walls while maintaining visual contact with virtual fish. The implementation of this VR system provides critical insights into sensory and cognitive processes underlying collective movement and decision-making in fish. By revealing both flexibility and constraints in fish behavior, our findings underscore the potential of VR technology to study social interactions in controlled yet realistic settings. Ultimately, this VR system advances our understanding of collective animal behaviors and lays a foundation for future studies across different species, enhancing insights into the neural and behavioral mechanisms of group dynamics
Lutter hors des partis : la gauche révolutionnaire italienne des années 1960-1980. Témoignages de militantes et de militants extra-parlementaires
No full textInternational audienceSi les caractéristiques idéologiques et sociodémographiques qui expliquent l’activisme armé sont partagées par les militant.e.s et les non-militant.e.s, quels facteurs supplémentaires expliquent pourquoi certains membres d’un groupe ou d’un réseau prennent part à un activisme révolutionnaire à « haut risque » (McAdam, 1986; Sommier, 2008) ? On tend à considérer que la violence politique émerge au carrefour de changements d’environnement politique, de la répression étatique, de la concurrence entre mouvements sociaux et de l’existence de contre-mouvements (Bosi, 2012, p. 178). Au sein de cet environnement politique, certains événements trouvent une signification spécifique.Pour mettre en évidence la fonction de ces événements et facteurs spécifiques, dans les « trajectoires en radicalité » des militant.e.s de la gauche extra-parlementaire italienne des années 1960-1980, nous avons mené une enquête auprès de 33 personnes impliquées dans ces organisations (Brigades Rouges - BR, Prima Linea - PL, Lotta Continua - LC, Potere Operaio - PO, Autonomie ouvrière). À partir de leurs récits biographiques, nous souhaitons faire ressortir les facteurs favorisant (facilitating factors) et les facteurs précipitant (precipating factors) l’engagement illégal ou clandestin dans un contexte macrosocial de forte tension politique et de violence entre groupes extra-parlementaires ainsi que de la part de l’État contre l’extrême gauche. Pour les préciser, nous tentons d’identifier les interactions qui dessinent les « mécanismes » du passage à l’illégalité et à la lutte armée. Les reconstructions biographiques collectées permettent d’appréhender les milieux militants, les représentations et perceptions qu’ont les actrices et les acteurs de leur environnement et du monde social, leurs définitions des coûts et des avantages de la participation politique, leur socialisation politique ainsi que la dynamique de production et de maintien d’une identité collective
CONNECTING MAX-ENTROPY WITH COMPUTATIONAL GEOMETRY, LP AND SDP
No full textInternational audienceWe consider the well-known max-(relative) entropy problem Θ(y) = infQ≪P DKL(Q P ) with Kullback-Leibler divergence on a domain Ω ⊂ R d , and with "moment" constraints h dQ = y, y ∈ R m . We show that when m ≤ d, Θ is the Cramér transform of a function v that solves a simply related computational geometry problem. Also, and remarkably, to the canonical LP: min x≥0 {c T x : A x = y}, with A ∈ R m×d , one may associate a max-entropy problem with a suitably chosen reference measure P on R d + and linear mapping h(x) = Ax, such that its associated perspective function ε Θ(y/ε) is the optimal value of the log-barrier formulation (with parameter ε) of the dual LP (and so it converges to the LP optimal value as ε → 0). An analogous result also holds for the canonical SDP: min X 0 { C, X : A(X) = y }
Decentralized multi-agent multi-armed bandits for smart electric vehicles charging
No full textInternational audienceSmart charging of electrical vehicles can help in avoiding congestion and peak load demands in an electrical distribution network. On the consumer's side, the advantage lies in minimizing the daily charging cost. He may also benefit from cheap photovoltaic electricity from local sources and therefore reduce his environmental impact. However, this cheaper electricity is variable and uncertain. In many research works, this has been formulated and solved as a centralized or hierarchical optimization problem. However, such systems may suffer from lack of scalability, single point of failures, and privacy breaches. We propose a fully decentralized and fair multi-agent system combined with reinforcement learning called "Decentralised multi-armed bandit (2-armed bandit) based on Thompson sampling"(D-MAB2AB-TS) to control the charging of electrical vehicles under uncertainties. The problem under consideration is formulated as a two-armed bandit (charging or not) for each instant. The proposed algorithm, based on Thompson Sampling, takes into account the uncertainties in the choice of arms combination of other players. The proposed algorithm finds the best combination of arms to play with a computational complexity O(m) linear with the number of arms. The suggested system is also model-free, as it does not assume the model of the environment to be perfectly known, which is a common assumption in many of the existing centralized optimization strategies for smart charging.</div
NERdME: a Named Entity Recognition Dataset for Indexing Research Artifacts in Code Repositories
No full textInternational audienceExisting scholarly information extraction (SIE) datasets focus on scientific papers and overlook implementation-level details in code repositories. README files describe datasets, source code, and other implementation-level artifacts, however, their free-form Markdown offers little semantic structure, making automatic information extraction difficult. To address this gap, NERdME is introduced: 200 manually annotated README files with over 10,000 labeled spans and 10 entity types. Baseline results using large language models and fine-tuned transformers show clear differences between paperlevel and implementation-level entities, indicating the value of extending SIE benchmarks with entity types available in README files. A downstream entity-linking experiment was conducted to demonstrate that entities derived from READMEs can support artifact discovery and metadata integration.</div
Fouilles programmées 2023 sur le site de Balchiria (Sartène, Corse du sud) : un centre cérémoniel de l’horizon pré-mégalithique
No full textNational audienceLa découverte fortuite, en 2016, de deux stèles, dont une présentant une iconographie inédite en Méditerranée, a motivé la mise en place d’une série d’opérations de fouilles programmées sur le site de Balchiria, sur la communede Sartène, en Corse-du-Sud. Les opérations conduites entre 2020 et 2023 sous la codirection de la DRAC de Corse et l’Université de Strasbourg, ont permis de contextualiser ces monuments en mettant en évidence plusieursarchitectures de pierres dont certaines peuvent être identifiées à des podiums. Le plus spectaculaire d’entre-deux, de plan naviforme, a conservé une douzaine de petits monolithes découverts en place, encore dressés ou légèrement inclinés. Deux aires empierrées voisines, de plan circulaire ou quadrangulaire sont, en toute hypothèse, assimilées soit à des podiums, soit à des aires cérémonielles
Portrait en jazz
No full textInternational audienceThe musical portraits created by jazz pianist Chick Corea illustrate a possible practice of mimesis in music, as the philosopher Francis Wolff sees it: representation rather than reproduction. In spite of this, while for the musical action itself the presence of a model quickly becomes negligible, for the musician and the audience it proves to be quite necessary.Les portraits musicaux réalisés par le pianiste de jazz Chick Corea illustrent bien une pratique possible de la mimesis en musique telle que la pense le philosophe Francis Wolff : une représentation davantage qu’une reproduction. En dépit de cela, alors que pour l’action musicale en elle-même la présence d’un modèle devient vite négligeable, pour le musicien et l’auditoire il s’avère pourtant bien nécessaire
Uncertain-graph framework for restingstate connectivity analysis in coma
No full textInternational audienceComa leads to persistent cognitive deficits, but underlying network disruptions remain unclear. Resting-state functional connectivity (FC) often probes these changes with graph-based metrics. Traditional graph approaches have key limitations:1. FC edges are based on correlations between regional mean signals, discarding voxel-level variability.2. Graph construction relies on arbitrary thresholds, which may exclude patients with severely disrupted connectivity.To address these challenges, we developed a voxel-informed, probabilistic framework for subject-level networks with finer granularity than traditional thresholded graphs
Assessing the benefits of part-night lighting on a tropical bat species endemic to Reunion Island
No full textInternational audienceArtificial light at night (ALAN) is recognised as an emerging threat to global biodiversity but no technical mitigation strategy can prevent all impacts on ecosystems. Consequently, the most effective measure remains turning-off lights whenever and wherever possible. However, few studies, all carried out in temperate environments, assessed the effectiveness of Part-Night Lighting (PNL) and the benefits that might result from changes in switch-off times. On the tropical Reunion Island, where ALAN is increasing exponentially, we assessed the sensitivity of an endemic bat species (Mormopterus francoismoutoui) to light, and the effectiveness of PNL in reducing the potential impacts on this species, depending on the switch-off times implemented. We took advantage of the modification of an existing PNL during a month-long event, consisting in switching off lights two hours earlier than the rest of the year. By carrying out an acoustic monitoring of bat echolocation calls, using a Before-After Control-Impact Paired protocol, we showed that bats were attracted to lit sites, especially at the beginning and end of the night, when the lights were on. When the lights were switched off earlier in the evening, there was no longer any impact on bat activity and rhythm, although a tendency toward greater activity at the end of the night in lit sites persisted in clear weather. This provides important insights, encouraging extensive use of PNL, ideally with even earlier switch-off times, as a promising measure for mitigating ALAN effects on this endemic species whose overall population vulnerability is still unknown
