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Certifying the Decidability of the Word Problem in Monoids at Large
No full textInternational audienceWhile the word problem for monoids is undecidable in general, having a decision procedure for some finitely presented monoid of interest has numerous applications. This paper presents a toolbox for the Rocq proof assistant that can be used to verify the decidability of the word problem for a given monoid and, in some cases, to produce the corresponding decision procedure. As this verification can be computationally intensive, the toolbox heavily relies on proofs by reflection guided by an external oracle. This approach has been successfully used on several large presentations from the literature, as well as on a database of one million 1-relation monoids.The huge size of this database forced some unusual considerations onto the Rocq formalization, so that the formal proofs could be checked in a reasonable amount of time.</p
Efficient Unrolled Networks for Large-Scale 3D Inverse Problems
No full textDeep learning-based methods have revolutionized the field of imaging inverse problems, yielding state-of-the-art performance across various imaging domains. The best performing networks incorporate the imaging operator within the network architecture, typically in the form of deep unrolling. However, in large-scale problems, such as 3D imaging, most existing methods fail to incorporate the operator in the architecture due to the prohibitive amount of memory required by global forward operators, which hinders typical patching strategies. In this work, we present a domain partitioning strategy and normal operator approximations that enable the training of end-to-end reconstruction models incorporating forward operators of arbitrarily large problems into their architecture. The proposed method achieves state-of-the-art performance on 3D X-ray cone-beam tomography and 3D multi-coil accelerated MRI, while requiring only a single GPU for both training and inference
First order logic and twin-width in tournaments and dense oriented graphs
No full textInternational audienceWe characterise the classes of tournaments with tractable first-order model checking. For every hereditary class of tournaments T , first-order model checking is either fixed parameter tractable or AW[ * ]hard. This dichotomy coincides with the fact that T has either bounded or unbounded twin-width, and that the growth of T is either at most exponential or at least factorial. From the model-theoretic point of view, we show that NIP classes of tournaments coincide with bounded twin-width. Twin-width is also characterised by three infinite families of obstructions: T has bounded twin-width if and only if it excludes at least one tournament from each family. This generalises results of Bonnet et al. on ordered graphs.The key for these results is a polynomial time algorithm that takes as input a tournament T and computes a linear order < on V (T ) such that the twin-width of the birelation (T, <) is at most some function of the twin-width of T . Since approximating twin-width can be done in polynomial time for an ordered structure (T, <), this provides a polynomial time approximation of twin-width for tournaments.Our results extend to oriented graphs with stable sets of bounded size, which may also be augmented by arbitrary binary relations.</div
Quand Érec rencontre Erec(k). Réflexions croisées sur l’édition et l’interprétation des romans deChrétien de Troyes et de Hartmann von Aue
No full textInternational audienceHartmanns von Aue Erec, die deutschsprachige Übertragung des ersten Artusromans Chrétiens de Troyes Érec et Énide, ist ein paradigmatisches Beispiel für die intensive Zirkulation von Erzählstoffen im westeuropäischen Kulturraum des Mittelalters. Aus unterschiedlichen Gründen hat für beide Romane jeweils eine Handschrift (Paris, BnF fr. 794 und Wien, ÖNB, Cod. Ser. nova 2663) eine zentrale Rolle in der editorischen und kritischen Tradition gespielt. Vorliegender Beitrag zieht eine vergleichende Bilanz der Editionsgeschichte beider Texte, der damit verbundenen Debatten sowie ihrer Folgen für die Interpretation der Texte und die Erfassung beider Autorfiguren. Aus den gekreuzten Blicken geht hervor, wie produktiv eine komparatistische Perspektive sein kann, welche die Transformationen der Texte sowohl durch ihre Überlieferung als auch durch die Editionspraxis mit einbezieht.La traduction-réécriture en langue allemande, par Hartmann von Aue à la fin du XIIe siècle, du premier roman composé par Chrétien de Troyes, Érec et Énide, est un exemple bien connu de l’intense circulation de la matière narrative dans l’espace occidental médiéval. Pour chacun des textes, un manuscrit a joué un rôle central dans les traditions éditoriale et critique (Paris, BnF fr. 794 pour le texte de Chrétien, Wien, ÖNB, Cod. Ser. nova 2663 pour celui de Hartmann). Le présent article dresse un bilan de l’histoire des éditions des deux romans, des débats auxquels elles ont donné lieu et de leurs conséquences sur l’interprétation des textes et la perception de leurs auteurs. Ce bilan croisé vise à mettre en valeur l’intérêt, pour la démarche comparatiste, de tenir compte des particularités de la tradition textuelle et de l’influence des pratiques des éditeurs modernes
A Scaled Poisson Bayesian Model for Viral Epidemic Monitoring
No full textInternational audienceMonitoring an ongoing epidemic requires accurate, trustworthy and easy to use tools, capable of handling low quality data. Extending existing epidemiological models quantifying the propagation intensity via a time-varying reproduction number, this work proposes a scaled Poisson model, accounting for large intrinsic variability in infection counts. The associated scaled likelihood is plugged into a Bayesian model with a quasi-noninformative prior. A carefully designed Markov Chain Monte Carlo algorithm yields a point estimate and credibility intervals of the reproduction number. The accuracy and robustness to model misspecification and to scale parameter selection of the proposed estimator is demonstrated through intensive numerical experiments on COVID-19 case counts in different countries and during various phases of the pandemic
Cyclic exclusive enteral nutrition versus partial enteral nutrition to maintain long-term drug-free remission in paediatric Crohn's disease (CD-HOPE): an open-label, endpoint-blinded, randomised controlled trial
No full textInternational audienceBackgroundFor children with Crohn's disease, there is a marked demand for long-term nutritional treatment strategies to avoid the side-effects related to drug treatment. We aimed to investigate whether paediatric patients with Crohn's disease responding to nutritional induction therapy can be maintained in remission on dietary therapy without the use of medication or surgery.MethodsIn this open-label, endpoint-blinded, randomised controlled trial (CD-HOPE) done in 21 hospitals of the GETAID pédiatrique network in France, eligible patients were aged 6 years to younger than 18 years with Crohn's disease (newly diagnosed or relapsing after drug treatment) who had reached clinical remission (weighted Paediatric Crohn's Disease Activity Index [wPCDAI] ≤12·5) after induction therapy with 6–12 weeks of exclusive enteral nutrition (EEN; 100% of calories). Stratified by age (≤10 years or >10 years) and relapse status, patients were randomly assigned (1:1) using block randomisation to receive either cyclic EEN (C-EEN; 100% of daily caloric requirements) for 2 weeks every 8 weeks for at least six cycles or daily partial enteral nutrition (PEN; 25% of daily caloric requirements) for 52 weeks. Oral MODULEN IBD was used for both. Except for the 2-week intervals of EEN in the C-EEN group, food access was not restricted. The primary endpoint was relapse rate at 12 months. A relapse was defined as: (1) a wPCDAI score greater than 12·5 at two successive visits, or (2) a wPCDAI greater than 12·5 once and the need for Crohn's disease-related surgery, medication, or study exit, or (3) a wPCDAI score continuously greater than 12·5 since the last study visit, or (4) incomplete wPCDAI and moderate or severe Physician Global Assessment at any timepoint. Primary and safety analyses were performed on an intention-to-treat basis. This trial was registered on ClinicalTrials.gov (NCT02201693) and is complete.FindingsBetween Dec 12, 2014, and Sept 4, 2018 (last patient visit Oct 2, 2019), 112 patients were screened and 100 patients (70 boys and 30 girls) were randomly assigned to C-EEN (n=49) or PEN (n=51). Median age of participants was 12 years (IQR 11–13) in the C-EEN group and 13 years (11–14) in the PEN group. At 12 months, 24 (49%) of 49 patients had relapsed on C-EEN compared with 39 (76%) of 51 patients on PEN (adjusted odds ratio 0·29 [95% CI 0·13–0·70], p=0·0051). 19 adverse events occurred in 17 patients: four serious adverse events in four patients on PEN, not related to treatment, and 15 non-serious adverse events in 13 patients (nine in seven patients on C-EEN and six in six patients on PEN). The serious adverse events were all related to Crohn's disease relapse requiring hospitalisation for rescue therapy. Six adverse events were possibly related to study treatment: one patient in the C-EEN group reported transient vomiting and diarrhoea at the start of the first EEN cycle, one patient in the C-EEN group developed anorexia and, in the PEN group, four patients reported either weight loss, nausea, Crohn's disease relapse, or skin infection. No malignancy or death was reported in this study.InterpretationC-EEN was superior to PEN in maintaining clinical remission over 1 year in paediatric patients with Crohn's disease responding to EEN induction therapy. These findings suggest a new way to use nutritional therapy for maintaining drug-free long-term remission in patients with Crohn's disease who are responding to EEN induction therapy.FundingAssistance Publique-Hôpitaux de Paris and Nestlé Health Science
Déploiement et Maillage de stations instrumentées en IoT sur le territoire pour diverses études_AG AnaEE 2026 "ECOLOGGING"
No full textInternational audienceIn this poster, we present the deployments of the different types of instrumented stations developed within the framework of the "ECOLOGGING” project, carried out during the year 2024/2025, as well as the main developments, the results obtained, and the conclusions. The “ECOLOGGING” stations are deployed according to the nature of the studies conducted and the associated specific scientific needs.Dans ce poster, nous présentons les déploiements des différents types de stations instrumentées développées dans le cadre du projet "ECOLOGGING", réalisés au cours de l’année 2024/2025, ainsi que les principales évolutions, les résultats obtenus et les conclusions. Les stations ECOLOGGING sont déployées en fonction de la nature des études menées et des besoins scientifiques spécifiques associés
David Graeber ou l’art de défaire les évidences - AOC media
No full textParu dans : AOC media - Analyse Opinion Critique, 23 janvier 2026, Opinion, URL : https://aoc.media/analyse/2026/01/22/david-graeber-ou-lart-de-defaire-les-evidences/International audienceLa récente publication d’un ouvrage collectif consacré à David Graeber, ainsi que la traduction commentée d’un de ses textes, offrent l’occasion de revisiter la portée actuelle de ses analyses. Ses réflexions sur le travail, les bullshit jobs, la bureaucratie, la dette ou la démocratie éclairent avec une clarté singulière les tensions contemporaines et les impasses de nos institutions.Paru dans : AOC media - Analyse Opinion Critique, 23 janvier 2026, Opinion, URL : https://aoc.media/analyse/2026/01/22/david-graeber-ou-lart-de-defaire-les-evidences
Types listes pour les langages conscient des ressources : une approche implicite
No full textA novel formalisation of variable control in languages with implicit names based on de Bruijn indices is presented.We design and implement three languages: first, a restricted language with implicit names; then, a restricted calculus with implicit names and explicit substitution, and finally, an extended calculus with implicit names, implicit substitution and resource control. We propose a novel concept of list types, which are used to give a simple and manageable definition of linearity. We develop an implementation in Haskell