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More powerful energetic reasoning for the cumulative scheduling problem
No full textInternational audienceEnergetic reasoning is an efficient filtering technique for the Cumulative SchedulingProblem. In this paper we propose a new definition of the energy balance of intervals,together with a new checker that is more accurate for each interval. Our approachinvolves solving a tripartition problem. For checking the intervals, we also propose acubic algorithm leveraging our approach. We report computational results that confirmthat it is more efficient than the classical approaches
Mapping urban vitality: geospatial analysis of commercial diversity and tourism
No full textInternational audienceBusiness diversity in proximity-based environments is emerging as an important requirement in urban planning, especially with the rise of concepts such as the 15-min city, which aim to enhance urban vitality. While many studies have focused on assessing vitality through the conditions defined by Jane Jacobs, few have specifically measured commercial diversity and analyzed its relationship with place popularity, attendance, and tourism activity. Using geo-localized data on businesses and Google Maps reviews in Paris, a diversity index was constructed based on Shannon entropy derived from business categories—Culture and leisure, Food and beverage, Retail stores, Local services—and explored its correlations through statistical analysis. The study reveals a higher level of commercial diversity in central areas compared to the outskirts, as indicated by spatial clustering analysis, along with a positive association between diversity and attendance. However, no significant relationship was observed between commercial diversity and the popularity of the selected establishments. These findings may inform policymakers and urban planners in designing more locally diversified cities and, more broadly, in promoting sustainable urban vitality
Order Matters: 3D Shape Generation from Sequential VR Sketches
No full textVR sketching lets users explore and iterate on ideas directly in 3D, offering a faster and more intuitive alternative to conventional CAD tools. However, existing sketch-to-shape models ignore the temporal ordering of strokes, discarding crucial cues about structure and design intent. We introduce VRSketch2Shape, the first framework and multi-category dataset for generating 3D shapes from sequential VR sketches. Our contributions are threefold: (i) an automated pipeline that generates sequential VR sketches from arbitrary shapes, (ii) a dataset of over 20k synthetic and 900 hand-drawn sketch-shape pairs across four categories, and (iii) an order-aware sketch encoder coupled with a diffusion-based 3D generator. Our approach yields higher geometric fidelity than prior work, generalizes effectively from synthetic to real sketches with minimal supervision, and performs well even on partial sketches. All data and models will be released open-source at https://chenyizi086.github.io/VRSketch2Shape_website
Are There Differences in Ankle Mechanics After Total Ankle Arthroplasty in Patients Suffering From Post-fracture vs Post-sprain End-Stage Ankle Osteoarthritis?
No full textInternational audienceBackground: To our knowledge, no study is available comparing the change in ankle mechanics during gait after total ankle arthroplasty (TAA) based on the origin of the osteoarthritis. As the nature of trauma is different in patients sustaining post-fracture ankle osteoarthritis (PFOA) from those sustaining post-sprain ankle osteoarthritis (PSOA), it could be expected that the outcomes of TAA, in terms of ankle mechanics during gait, would be different in the 2 groups. A prospective matched comparative study was therefore performed to investigate whether patients sustaining PFOA had different outcomes in terms of changes to ankle mechanics during gait (before surgery vs 1 year after surgery), compared with patients sustaining PSOA. Methods: Fifteen patients with PFOA and 15 patients with PSOA scheduled for primary TAA for pain relief were recruited and peer-matched based on their demographic and spatiotemporal data. All patients underwent a 3D gait analysis before and after surgery, during which a kinematic and kinetic multi-segment foot model was used to quantify inter-segmental joint kinematics and kinetics. Results: The PFOA group exhibited significantly lesser pre- vs postoperative increases in ankle (Shank-Calcaneus) joint peak power, and ankle (Shank-Calcaneus) joint work after TAA compared with the PSOA group. Furthermore, the results demonstrated a trend toward greater increases in peak ankle (Shank-Calcaneus) joint plantarflexion moment and in negative ankle (Shank-Calcaneus) joint work for the PSOA group compared with the PFOA group. Conclusion: This study suggests that patients sustaining PFOA have smaller pre- to postoperative gains in ankle (Shank-Calcaneus) joint power and ankle (Shank-Calcaneus) joint work during gait after TAA compared with patients sustaining PSOA, with modest between-group effects. Although evidence in TAA is lacking, insights from knee replacement suggest prehabilitation and nutritional support may mitigate deficits, representing a potentially essential strategy for PFOA patients requiring further validation
On the spectral radius and the characteristic polynomial of a random matrix with independent elements and a variance profile
No full textInternational audienceIn this paper, it is shown that with large probability, the spectral radius of a large non-Hermitian random matrix with a general variance profile does not exceed the square root of the spectral radius of the variance profile matrix. A minimal moment assumption is considered and sparse variance profiles are covered. Following an approach developed recently by Bordenave, Chafaï and García-Zelada, the key theorem states the asymptotic equivalence between the reverse characteristic polynomial of the random matrix at hand and a random analytic function which depends on the variance profile matrix. The result is applied to the case of a non-Hermitian random matrix with a variance profile given by a piecewise constant or a continuous non-negative function, the inhomogeneous (centered) directed Erdős-Rényi model, and more.</div
Stability analysis of the Kalman filter under practical conditions
No full textInternational audienceThe Kalman filter is optimal in the sense of minimum variance under the assumptions of white noises and perfect model-system matching. If these assumptions are not satisfied, the filter loses its optimality. Does it, however, remain a good state estimator with stable error dynamics? The answer to this question cannot rely on the classical stability proof of the Kalman filter, which was based on its optimality. It is shown in this paper that, without the restrictive assumptions of white noises and perfect model-system matching, the Kalman filter has an exponentially stable error dynamics under observability and controllability conditions. Moreover, the second moment of its state estimation error has an upper bound linearly depending on the discrepancies between model and system. In this sense, the Kalman filter is stable and remains a good state estimator under practical conditions
Portrait de l’entrepreneur en époux épaulé (affaire(s) de couple dans la série Tapie)
No full textInternational audienceDrawing on an analysis of the miniseries Tapie (Tristan Séguéla, 2023), this article demonstrates how it offers a renewed vision of the entrepreneurial couple, particularly by suggesting that the wife of the French businessman played a decisive role in the management and strategy of his company. This representation is examined in relation to the historical iconography of the entrepreneur, whose stereotypes have portrayed him as a virile, omniscient masculine figure with intuitively successful ventures. By revealing Bernard Tapie’s vulnerabilities and the active role of his wife (in private), the series emphasizes the gap between management practices and their figurative embodimentÀ partir d’une analyse de la série Tapie (Tristan Séguéla, 2023), cet article montre comment elle propose une vision rénovée du couple d’entrepreneurs, notamment en suggérant que la femme de l’homme d’affaires français a eu un rôle décisif dans la gestion et la stratégie de son entreprise. Cette représentation est étudiée en regard de l’iconographie historique de l’entrepreneur, dont les stéréotypes ont fait une figure masculine virile et omnisciente, aux intuitions couronnées de succès. En révélant les fragilités de Bernard Tapie et le rôle actif de sa femme (en privé), la série insiste sur l’écart entre le management et son incarnation figurative
Monitoring litter typology and loading in stormwater: Implications for waste management and mitigation policies
No full textInternational audienceSewer systems are an overlooked pathway of litter to rivers. We monitored six combined and four separate sewer outlets in France using retention nets over several years to quantify and characterize over 30,000 items > 5 mm, including 91% plastic debris. Total median loading rates were 155 g ha -1 yr -1 (120 g.ha -1 .yr -1 for plastics) and 8 g cap -1 yr -1 (6 g cap -1 .yr -1 for plastics), consistent with the few previous studies available in stormwater and rivers, although litter typology is different. Combined sewers were dominated by sanitary products like wet wipes and towels (46% of plastic mass), while separate systems were dominated by cigarette butts and food packaging related to on-the-go consumption. Sewer monitoring proved complementary to river monitoring, with fewer unidentified items (~15%) and clearer source attribution. Management strongly influenced maintenance costs: internal management and incineration by public authorities was far cheaper (800 € per net and per year) than outsourced landfill disposal (16,000 € per net and per year). Despite operational limits of nets, sewer monitoring provides robust data for litter flux models and for evaluating upstream mitigation policies. Expanding such monitoring, supported by sustained funding and international coordination, will afford reliable and homogeneous method for litter loading estimates into rivers and their source identification:an essential step toward an effective plastics treaty
De Booba à Indexia : ce que les scandales révèlent des angles morts de la recherche en management
No full textInternational audienceÀ partir des scandales Booba et Indexia, ce texte explore les angles morts de la recherche en management. Il met en évidence les limites épistémologiques, méthodologiques, conceptuelles et éthiques qui empêchent la discipline de penser les phénomènes émergents, ambivalents ou déviants, en dépit de leur impact sociétal parfois considérable. En dialogue avec les travaux critiques récents, il propose des pistes pour renouveler les objets, les méthodes, les engagements et la formation en management, afin de proposer une autre conception de la responsabilité académique
Enseigner la culture de la sécurité avec la simulation aéronautique : cas d’usages en IAE et IUT - Partie 2
No full textInternational audienceDans le cadre de travaux communs, menés fin 2024 et début 2025, sur le déploiement pédagogique de plateformes de simulation aéronautique à l’IAE Paris-Est (Université Paris-Est Créteil) et l’IUT de Colmar (Université Haute-Alsace), nous avons questionné les apprenants sur les niveaux 1 et 2 du modèle d’évaluation des formations de Kirkpatrick & Kirkpatrick (2016). De plus, nous avons également mesuré l’acquisition des connaissances au travers d’un test identique en amont et en aval de chaque enseignement. Ce poster rend compte des premiers résultats bruts obtenus