Hal - Université Grenoble Alpes
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Reconsidering mistakes: reproduction and replication of Nielsen and Rehbeck (2022)
No full textThere is a long-standing debate as to whether violations of rational choice axioms reflect normative deviations from the theory or simply mistakes. We contribute to this debate by reproducing and replicating Nielsen and Rehbeck's (2022) experimental study, with a new focus on heterogeneity across axioms. We conduct a three-part analysis comprising a direct computational reproduction, a robustness reproduction, and a high-powered preregistered replication (N = 451) focusing on the Independence of Irrelevant Alternatives (IIA). We find robust evidence that individuals express a desire to follow canonical axioms, but perceive violations as mistakes only for a subset of them-specifically, IIA and Transitivity. In contrast, we find no evidence that violations of Independence, First-Order Stochastic Dominance, Branching, or Consistency are perceived as mistakes. We discuss these findings through the lens of cognitive complexity, suggesting that individuals may fail to recognize violations of more demanding axioms even when prompted
Reconstruction of atmospheric neutrinos in DUNE's horizontal-drift far-detector module
No full textInternational audienceThis paper reports on the capabilities in reconstructing and identifying atmospheric neutrino interactions in one of the Deep Underground Neutrino Experiment's (DUNE) far detector modules, a liquid argon time projection chamber (LArTPC) with horizontal drift (FD-HD) of ionization electrons. The reconstruction is based upon the workflow developed for DUNE's long-baseline oscillation analysis, with some necessary machine-learning models' retraining and the addition of features relevant only to atmospheric neutrinos such as the neutrino direction reconstruction. Where relevant, the impact of the detection of the charged particles of the hadronic system is emphasized, and comparisons are carried out between the case when lepton-only information is considered in the reconstruction (as is the case for many neutrino oscillation experiments), versus when all particles identified in the LArTPC were included. Three neutrino direction reconstruction methods have been developed and studied for the atmospheric analyses: using lepton-only information, using all reconstructed particles, and using only correlations from reconstructed hits. The results indicate that incorporating more than just lepton information significantly improves the resolution of both neutrino direction and energy reconstruction. The angle reconstruction algorithms developed in this work result in no strong dependence on particle direction for reconstruction efficiencies or neutrino flavor identification. This comprehensive review of the reconstruction of atmospheric neutrinos in DUNE's FD-HD LArTPC is the first step towards developing a first neutrino oscillation sensitivity analysis, which will ready DUNE for its first measurements
Les OPH privés de domaine public (note sous CA Amiens, 18 septembre 2025, n° 24/01047, SELARL Evolution, liquidateur de la SAC c./ OPH Aisne)
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Contentieux des « redevances plaisance » : quand le juge du fond dérive (obs. sous TJ Nice, 30 oct. 2025, SA SPL des ports de Menton, n° 23/04752)
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Nemesis, an Escape Game in Graphs
No full textWe define a new escape game in graphs that we call Nemesis. The game is played on a graph having a subset of vertices labeled as exits and the goal of one of the two players, called the fugitive, is to reach one of these exit vertices. The second player, i.e. the fugitive adversary, is called the Nemesis. Her goal is to trap the fugitive in a connected component which does not contain any exit. At each round of the game, the fugitive moves from one vertex to an adjacent vertex. Then the Nemesis deletes one edge anywhere in the graph. The game ends when either the fugitive reached an exit or when he is in a connected component that does not contain any exit. In trees and graphs of maximum degree bounded by 3, Nemesis can be solved in linear time. We also show that a variant of the game called Blizzard where only edges adjacent to the position of the fugitive can be deleted also admits a linear time solution. For arbitrary graphs, we show that Nemesis is PSPACE-complete, and that it is NP-hard on planar multigraphs. We extend our results to the related Cat Herding problem, proving its PSPACE-completeness. We also prove that finding a strategy based on a full binary escape tree whose leaves are exists is NP-complete
Statistical estimation of a mean-field fitzhugh-nagumo model
No full textWe consider an interacting system of particles with value in R d × R d , governed by transport and diffusion on the first component, on that may serve as a representative model for kinetic models with a degenerate component. In a first part, we control the fluctuations of the empirical measure of the system around the solution of the corresponding Vlasov-Fokker-Planck equation by proving a Bernstein concentration inequality, extending a previous result of [DMH22] in several directions. In a second part, we study the nonparametric statistical estimation of the classical solution of Vlasov-Fokker-Planck equation from the observation of the empirical measure and prove an oracle inequality using the Goldenshluger-Lepski methodology and we obtain minimax optimality. We then specialise on the FitzHugh-Nagumo model for populations of neurons. We consider a version of the model proposed in Mischler et al. [MQT16] an optimally estimate the 6 parameters of the model by moment estimators.</div
Measurement of differential -channel single top (anti)quark production cross-sections at 13 TeV with the ATLAS detector
No full textInternational audienceThe production of single top quarks and top antiquarks via the -channel exchange of a virtual boson is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider. The full Run 2 data sample recorded with the ATLAS detector in the years 2015-2018 is used, corresponding to an integrated luminosity of 140 fb. The absolute and normalised production cross-sections are measured differentially as a function of the transverse momentum and absolute rapidity of the top quark and top antiquark. In addition, the ratio of top quark to top antiquark production cross-sections is measured. The measured distributions are compared with next-to-leading-order quantum chromodynamics predictions obtained with different combinations of matrix-element generators, parton-shower programs and proton parton distribution functions, as well as to next-to-next-to-leading-order calculations. Overall, good agreement is observed between the measurements and the theoretical predictions. For most measured distributions, the sensitivity to differences between the predictions is limited by the systematic uncertainties in the measurement. The measured differential distributions are also interpreted in an effective field theory approach to constrain the Wilson-Coefficient associated with a four-quark operator. The interpretation accounts for the effect of the selection efficiency, which is altered significantly by non-zero contributions from
FORMSpoT: A Decade of Tree-Level, Country-Scale Forest Monitoring
No full textThe recent decline of the European forest carbon sink highlights the need for spatially explicit and frequently updated forest monitoring tools. Yet, existing satellite-based disturbance products remain too coarse to detect changes at the scale of individual trees, typically below 100 m². Here, we introduce FORMSpoT (Forest Mapping with SPOT Time series), a decade-long (2014-2024) nationwide mapping of forest canopy height at 1.5 m resolution, together with annual disturbance polygons (FORMSpoT-Δ) covering mainland France. Canopy heights were derived from annual SPOT-6/7 composites using a hierarchical transformer model (PVTv2) trained on high-resolution airborne laser scanning (ALS) data. To enable robust change detection across heterogeneous acquisitions, we developed a dedicated post-processing pipeline combining co-registration and spatio-temporal total variation denoising. Validation against ALS revisits across 19 sites and 5,087 National Forest Inventory plots shows that FORMSpoT-Δ substantially outperforms existing disturbance products. In mountainous forests, where disturbances are small and spatially fragmented, FORMSpoT-Δ achieves an F1-score of 0.44, representing an order of magnitude higher than existing benchmarks. By enabling tree-level monitoring of forest dynamics at national scale, FORMSpoT-Δ provides a unique tool to analyze management practices, detect early signals of forest decline, and better quantify carbon losses from subtle disturbances such as thinning or selective logging. These results underscore the critical importance of sustaining very high-resolution satellite missions like SPOT and open-data initiatives such as DINAMIS for monitoring forests under climate change
Estimating the upper depth of subsurface water on the Greenland Ice Sheet using multi-frequency passive microwave remote sensing, radiative transfer modeling, and machine learning
No full textInternational audienceAs the Arctic warms, surface melt extends into the Greenland Ice Sheet's accumulation zone, where much of the water infiltrates into the snowpack. This makes monitoring the subsurface water depth and spatial extent important for accurate ice sheet runoff estimations. Subsurface water can be detected using remotely sensed microwave brightness temperatures (TB). We use vertically polarized TB at 1.4 GHz from Soil Moisture and Ocean Salinity satellite (SMOS) and at 6.9, 10.7, and 18.7 GHz from the Advanced Microwave Scanning Radiometers (AMSR-E/2) to estimate the upper depth of liquid water (UDLW) on the ice sheet accumulation area. We build a catalogue of simulated UDLW and TB: realistic UDLW are modeled by the Geological Survey of Denmark and Greenland (GEUS) snow model, forced by the Copernicus Arctic Regional Reanalysis (CARRA), and the corresponding TB are calculated by the Snow Microwave Radiative Transfer (SMRT) model at 19 sites. We train on this catalogue an ensemble of cross-validated Random Forest (RF) models to predict UDLW and its uncertainty from TB at four frequencies. On hold-out modeled data and for water within 5 m of the surface, the RF ensemble achieves a median RMSE of 0.68 m and mean error of −0.09 m. Our retrieval, when applied to observed TB, matches within 2 m UDLW inferred from subsurface temperature profiles down to 4–6 m depth. Performances decrease beyond 5 m depth and for low liquid water amounts. Our retrieval produces daily UDLW maps over the ice sheet's accumulation area during 2010–2023 which reveal the seasonal evolution of UDLW, deliver the first quantitative estimates of subsurface liquid water depth on the ice sheet and offer new insights into meltwater infiltration and storage processes
Intégrer des enjeux éthiques, sociétaux et environnementaux dans un cours de conception d'algorithmes
No full textThis document, intended for computer science teachers, describes a case study that puts into practice a questioning of ethical, societal and environmental issues when designing or implementing a decision support system. This study is based on a very popular application, namely road navigation software that informs users of real-time traffic conditions and suggests routes between a starting point and a destination, taking these conditions into account (such as Waze). The approach proposes to intertwine technical considerations (optimal path algorithms, data needed for location, etc.) with a broader view of the ethical, environmental and societal issues raised by the tools studied. Based on the authors' experience conducting sessions with students over several years, this document discusses the context of such a study, suggests teaching resources for implementing it, describes ways to structure discussions, and shares scenarios in different teaching contexts.Ce document, à destination des enseignants d'informatique, décrit une étude de cas qui met en pratique un questionnement sur les enjeux éthiques, sociétaux et environnementaux lors de la conception ou de la mise en œuvre d’un algorithme d'aide à la décision. Cette étude s'appuie sur une application très populaire, à savoir un logiciel d’aide à la navigation routière informant les utilisateurs des conditions de trafic en temps réel, et leur proposant des itinéraires entre une origine et une destination en tenant compte de ces conditions (type Waze). L'approche propose d'entrelacer des considérations techniques (algorithmes de chemins optimaux, données nécessaires pour se localiser, etc.) et une prise de recul sur les enjeux éthiques, environnementaux et sociétaux des outils étudiés. En s'appuyant sur l'expérience conduite par les auteurs depuis plusieurs années en séance face à des étudiants, ce document discute le contexte d'une telle étude, propose des ressources pédagogiques pour mettre en œuvre cette étude, décrit des pistes pour structurer les échanges et partage des scénarisations dans différents contextes pédagogiques