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3-colorable planar graphs have an intersection segment representation using 3 slopes
No full textInternational audienceIn his PhD Thesis E.R. Scheinerman conjectured that planar graphs are intersection graphs of line segments in the plane. This conjecture was proved with two different approaches by J. Chalopin and the author, and by the author, L. Isenmann, and C. Pennarun. In the case of 3-colorable planar graphs E.R. Scheinerman conjectured that it is possible to restrict the set of slopes used by the segments to only 3 slopes. Here we prove this conjecture by using an approach introduced by S. Felsner to deal with contact representations of planar graphs with homothetic triangles
Socially aware robot for reward, effort, and risk distribution
No full textInternational audienceIn this work we address the problem of designing a straightforward resource allocation decision making robot. We developed a model that accurately makes decisions to distribute risk, effort and reward between two humans or a human and a robot, considering their age, sex and humanness. To assess the model's alignment with social norms, we conducted a Turing test which showed that our model is perceived as making socially acceptable decisions, similar to those of human participants. Furthermore we demonstrated our model by embodying it in a robot negotiator that automatically distributed reward, effort and risk tokens among participant dyads by perceiving their physical characteristics
Transformations et appropriation des pratiques organisationnelles induites par le label Numérique responsable : analyse des pratiques mises en œuvre et des retombées économiques, sociales, sociétales et environnementales dans les organisations labellisées: Transformations and appropriation of organizational practices induced by Responsible Digitalisation : analysis of the practices implemented and the economic, social, societal and environmental impact in organizations awarded the label.
No full textInternational audienceCreated in 2019, the Responsible Digital (NR) label aims to support organizations in adopting more sustainable and ethical digital practices. To date, around a hundred organizations from a variety of sectors have been awarded the label, reflecting a growing interest in integrating social responsibility issues into organizational strategies. This research aims to assess the impact of obtaining the NR label on the overall performance of organizations engaged in this initiative. It analyzes the concrete practices implemented, as well as the economic, social, societal and environmental benefits. Beyond the analysis of measurable effects, the study also examines the way in which the label influences the internal dynamics of organizations, particularly in terms of governance, managerial culture and ownership by stakeholders (mainly managers and employees). The aim is to shed light on the tangible and intangible benefits associated with labeling, by highlighting the mechanisms by which economic, social and environmental value is created. Using a mixed methodological approach, combining quantitative and qualitative data, this research proposes an in-depth reading of the effects of the NR label on organizational transformation. The expected results are intended to enlighten public and private decision-makers on the conditions for the effectiveness of the scheme, and its capacity to act as a strategic lever in favor of sustainable and responsible organizational performance.Créé en 2019, le label Numérique Responsable (NR) vise à accompagner les organisations dans la mise en œuvre de pratiques numériques plus durables et éthiques. À ce jour, une centaine d’organisations, issues de secteurs variés, ont été labellisées, traduisant un intérêt croissant pour l’intégration des enjeux de responsabilité sociétale dans les stratégies organisationnelles. Cette recherche a pour ambition d’évaluer l’impact de l’obtention du label NR sur la performance globale des organisations engagées dans cette démarche. Elle s’attache à analyser les pratiques concrètes mises en œuvre ainsi que les retombées économiques, sociales, sociétales et environnementales qui en découlent. Au-delà de l’analyse des effets mesurables, l’étude interroge également la manière dont le label influence les dynamiques internes des organisations, notamment en termes de gouvernance, de culture managériale et d’appropriation par les parties prenantes (dirigeants et salariés principalement). L’objectif est de mettre en lumière les bénéfices tangibles et intangibles associés à la labellisation, en valorisant les mécanismes de création de valeur à la fois économique, sociale et environnementale. Mobilisant une approche méthodologique mixte, combinant des données quantitatives et qualitatives, cette recherche propose une lecture approfondie des effets du label NR sur la transformation organisationnelle. Les résultats attendus visent à éclairer les décideurs publics et privés sur les conditions d’efficacité du dispositif et sur sa capacité à constituer un levier stratégique en faveur d’une performance durable et responsable des organisations
Improved Rényi Arguments for Lattice-Based Threshold Encryption
No full textThreshold encryption schemes provide a common tool to secure a public-key encryption scheme against single point of failure attacks. Despite the success of lattices in building fully-homomorphic and presumably quantum-resistant encryption schemes, the task of thresholdizing those schemes remains challenging. The major bottleneck in the standard approach is the use of statistical noise flooding, leading to a significant efficiency loss and the need of stronger hardness assumptions. Recent works have replaced the heavy statistical noise flooding by a lighter one using the Rényi divergence. The new Rényi noise flooding both improves the efficiency and allows to use weaker hardness assumptions. However, arguing semantic security of lattice-based threshold schemes in the presence of Rényi noise flooding showed to be challenging. Chowdhury et al. (IACR ePrint'22) argued in the fully-homomorphic case that the Rényi divergence directly applies for semantic security by making use of an existing framework called public sampleability. In this work, we argue that their public sampleability framework was neither sufficient nor correctly used. To address both issues, we strengthen the framework and thoroughly apply it to prove semantic security of generic lattice-based threshold encryption constructions. We distinguish between the plain public-key and the fully-homomorphic settings, as different security notions are achieved. As a byproduct, this shows that the proof detour via one-way security made by Boudgoust and Scholl (Asiacrypt'23) was superfluous, now leading to tighter proofs in the standard model
Hardness of M-LWE with General Distributions and Applications to Leaky Variants
No full textThe Module Learning With Errors (M-LWE) problem has become a fundamental hardness assumption for lattice-based cryptography. It offers an attractive trade-o between strong robustness guarantees, sometimes directly based on worst-case lattice problems, and efficiency of the subsequent cryptographic primitives. Different flavors of M-LWE have then been introduced towards improving performance. Such variants look at different secret-error distributions and might allow for additional hints on the secret-error vector. Existing hardness results however only cover restricted classes of said distributions, or are tailored to specific leakage models. This lack of generality hinders the design of efficient and versatile cryptographic schemes, as each new distribution or leakage model requires a separate and nontrivial hardness evaluationIn this work, we address this limitation by establishing the hardness of M-LWE under general distributions. As a first step, we show that M-LWE remains hard when the error vector follows an arbitrary bounded distribution with sufficient entropy, with some restriction on the number of samples. Building on this, we then reduce to the Hermite Normal Form (HNF) where the secret-error vector follows said arbitrary distribution. Overall, our result shows the actual shape of the distribution does not matter, as long as it keeps sufficient entropy. To demonstrate the versatility of our framework, we further analyze a range of leakage scenarios. By examining the residual entropy given the leakage, we show that our results of M-LWE with general distributions encompass various types of leakage. More precisely, we cover exact and approximate linear hints which are widely used in recent cryptographic designs, as well as quadratic, and even non-algebraic forms, some of which were not yet covered by any theoretical hardness guarantees. The generality of our results aims at facilitating future cryptographic designs and security analyses
New Menger-Like Dualities in Digraphs and Applications to Half-Integral Linkages
No full textInternational audienceWe present new min-max relations in digraphs between the number of paths satisfying certain conditions and the order of the corresponding cuts. We define these objects in order to capture, in the context of solving the half-integral linkage problem, the essential properties needed for reaching a large bramble of constant congestion from the terminal set. This strategy has been used ad-hoc in several articles, usually with lengthy technical proofs, and our objective is to abstract it to make it applicable in a simpler and unified way. We provide two proofs of the min-max relations, one consisting in applying Menger’s Theorem on appropriately defined digraphs, and an alternative simpler one using matroids, however with worse polynomial running time. As an application, we manage to simplify and improve several results of Edwards et al. in 2017 and of Giannopoulou et al. in 2022 about finding half-integral linkages in digraphs. Concerning the former, besides being simpler, our proof provides an almost optimal bound on the strong connectivity of a digraph for it to be half-integrally feasible under the presence of a large bramble of congestion two (or equivalently, if the directed tree-width is large). Concerning the latter, our proof uses brambles as rerouting objects instead of cylindrical grids, hence yielding much better bounds and being somehow independent of a particular topology. We hope that our min-max relations will find further applications as, in our opinion, they are simple, robust, and versatile to be easily applicable to different types of routing problems in digraphs
Endoscopic Sinus Surgery in Frontal Sinus Inverted Papilloma: A Systematic Review
No full textInternational audienceBackground: Frontal sinus inverted papilloma (IP) is a particularly rare form of IP and its management is challenging, with a high rate of recurrence.Objectives: Our aim was to evaluate the recurrence rate of frontal sinus IP after surgery and compare this rate according to the surgical modality (purely endoscopic sinus surgery vs. a combined/open approach).Design: A systematic review without meta-analysis conducted by a working group of the Young Otolaryngologists of the International Federation of Otorhinolaryngological Societies (yo-IFOS).Data Sources and Methods: A systematic analysis of the literature was performed and reported following the criteria laid down in the SWiM guidelines. The review was registered on Prospero, a dedicated software was used for screening (Covidence), and R (v.4.2.2) was used for statistical analysis. Eligible articles were studies reporting at least five cases of frontal sinus IP surgically treated.Results: A total of 2925 studies were identified based on the MeSH equation, and 39 studies were included (n = 642 patients). Among the studies included, the recurrence rate 18.4% (118/642) with a mean time to recurrence of 25.6 (±11.7) months. The difference between surgical modalities was not statistically significant in terms of recurrence rate (14.7% vs. 16.5%; p = 0.675).Conclusions: The recurrence rate of frontal sinus IP is not different between surgical modalities. However, it does not reduce the need for a tailored therapeutic strategy, as other factors also need to be considered (time to recurrence, complications, quality of life) when choosing the most appropriate approach
Multi-Susceptibility: A Validated One Health Indicator of Antimicrobial Resistance
No full textInternational audienceA synthetic indicator applicable to both humans and animals, Representing an ecological measure of resistance, andServing as a foundational step toward a joint approach and communication on antimicrobial resistance. Multi-susceptibility represents the proportion of isolates exhibiting no resistance to a common set of antimicrobial classes tested in both animal and human populations
The influence of the random numbers quality on the results in stochastic simulations and machine learning
No full textPseudorandom number generators (PRNGs) are ubiquitous in stochastic simulations and machine learning (ML), where they drive sampling, parameter initialization, regularization, and data shuffling. While widely used, the potential impact of PRNG statistical quality on computational results remains underexplored. In this study, we investigate whether differences in PRNG quality, as measured by standard statistical test suites, can influence outcomes in representative stochastic applications. Seven PRNGs were evaluated, ranging from low-quality linear congruential generators (LCGs) with known statistical deficiencies to high-quality generators such as Mersenne Twister, PCG, and Philox. We applied these PRNGs to four distinct tasks: an epidemiological agent-based model (ABM), two independent from-scratch MNIST classification implementations (Python/NumPy and C++), and a reinforcement learning (RL) CartPole environment. Each experiment was repeated 30 times per generator using fixed seeds to ensure reproducibility, and outputs were compared using appropriate statistical analyses. Results show that very poor statistical quality, as in the "bad" LCG failing 125 TestU01 Crush tests, produces significant deviations in ABM epidemic dynamics, reduces MNIST classification accuracy, and severely degrades RL performance. In contrast, mid-and good-quality LCGs-despite failing a limited number of Crush or BigCrush tests-performed comparably to top-tier PRNGs in most tasks, with the RL experiment being the primary exception where performance scaled with statistical quality. Our findings indicate that, once a generator meets a sufficient statistical robustness threshold, its family or design has negligible impact on outcomes for most workloads, allowing selection to be guided by performance and implementation considerations. However, the use of low-quality PRNGs in sensitive stochastic computations can introduce substantial and systematic errors