Occitanie
Beyond Augmented-Action Surrogates for Multi-Expert Learning-to-Defer
Montreuil, Yannis, Carlier, Axel, Ng, Lai Xing, Ooi, Wei Tsang
Existing multi-expert learning-to-defer surrogates are statistically consistent, yet they can underfit, suppress useful experts, or degrade as the expert pool grows. We trace these failures to a shared architectural choice: casting classes and experts as actions inside one augmented prediction geometry. Consistency governs the population target; it says nothing about how the surrogate distributes gradient mass during training. We analyze five surrogates along both axes and show that each trades a fix on one for a failure on the other. We then introduce a decoupled surrogate that estimates the class posterior with a softmax and each expert utility with an independent sigmoid. It admits an $\mathcal{H}$-consistency bound whose constant is $J$-independent for fixed per-expert weight $β{=}λ/J$, and its gradients are free of the amplification, starvation, and coupling pathologies of the augmented family. Experiments on synthetic benchmarks, CIFAR-10, CIFAR-10H, and Covertype confirm that the decoupled surrogate is the only method that avoids amplification under redundancy, preserves rare specialists, and consistently improves over a standalone classifier across all settings.
- Asia > Singapore (0.04)
- North America > United States (0.04)
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.04)
CRPS-Optimal Binning for Univariate Conformal Regression
We propose a method for non-parametric conditional distribution estimation based on partitioning covariate-sorted observations into contiguous bins and using the within-bin empirical CDF as the predictive distribution. Bin boundaries are chosen to minimise the total leave-one-out Continuous Ranked Probability Score (LOO-CRPS), which admits a closed-form cost function with $O(n^2 \log n)$ precomputation and $O(n^2)$ storage; the globally optimal $K$-partition is recovered by a dynamic programme in $O(n^2 K)$ time. Minimisation of within-sample LOO-CRPS turns out to be inappropriate for selecting $K$ as it results in in-sample optimism. We instead select $K$ by $K$-fold cross-validation of test CRPS, which yields a U-shaped criterion with a well-defined minimum. Having selected $K^*$ and fitted the full-data partition, we form two complementary predictive objects: the Venn prediction band and a conformal prediction set based on CRPS as the nonconformity score, which carries a finite-sample marginal coverage guarantee at any prescribed level $\varepsilon$. The conformal prediction is transductive and data-efficient, as all observations are used for both partitioning and p-value calculation, with no need to reserve a hold-out set. On real benchmarks against split-conformal competitors (Gaussian split conformal, CQR, CQR-QRF, and conformalized isotonic distributional regression), the method produces substantially narrower prediction intervals while maintaining near-nominal coverage.
- North America > United States > Virginia > Virginia Beach (0.04)
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.04)
Lipschitz bounds for integral kernels
Reverdi, Justin, Zhang, Sixin, Gamboa, Fabrice, Gratton, Serge
Feature maps associated with positive definite kernels play a central role in kernel methods and learning theory, where regularity properties such as Lipschitz continuity are closely related to robustness and stability guarantees. Despite their importance, explicit characterizations of the Lipschitz constant of kernel feature maps are available only in a limited number of cases. In this paper, we study the Lipschitz regularity of feature maps associated with integral kernels under differentiability assumptions. We first provide sufficient conditions ensuring Lipschitz continuity and derive explicit formulas for the corresponding Lipschitz constants. We then identify a condition under which the feature map fails to be Lipschitz continuous and apply these results to several important classes of kernels. For infinite width two-layer neural network with isotropic Gaussian weight distributions, we show that the Lipschitz constant of the associated kernel can be expressed as the supremum of a two-dimensional integral, leading to an explicit characterization for the Gaussian kernel and the ReLU random neural network kernel. We also study continuous and shift-invariant kernels such as Gaussian, Laplace, and Matérn kernels, which admit an interpretation as neural network with cosine activation function. In this setting, we prove that the feature map is Lipschitz continuous if and only if the weight distribution has a finite second-order moment, and we then derive its Lipschitz constant. Finally, we raise an open question concerning the asymptotic behavior of the convergence of the Lipschitz constant in finite width neural networks. Numerical experiments are provided to support this behavior.
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.05)
- North America > United States > New York > New York County > New York City (0.04)
- North America > United States > Massachusetts > Suffolk County > Boston (0.04)
- Asia > Singapore (0.04)
Transfer Learning in Bayesian Optimization for Aircraft Design
Tfaily, Ali, Diouane, Youssef, Bartoli, Nathalie, Kokkolaras, Michael
The use of transfer learning within Bayesian optimization addresses the disadvantages of the so-called \textit{cold start} problem by using source data to aid in the optimization of a target problem. We present a method that leverages an ensemble of surrogate models using transfer learning and integrates it in a constrained Bayesian optimization framework. We identify challenges particular to aircraft design optimization related to heterogeneous design variables and constraints. We propose the use of a partial-least-squares dimension reduction algorithm to address design space heterogeneity, and a \textit{meta} data surrogate selection method to address constraint heterogeneity. Numerical benchmark problems and an aircraft conceptual design optimization problem are used to demonstrate the proposed methods. Results show significant improvement in convergence in early optimization iterations compared to standard Bayesian optimization, with improved prediction accuracy for both objective and constraint surrogate models.
- Europe > Italy (0.04)
- North America > United States > New Jersey (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
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Multi-fidelity approaches for general constrained Bayesian optimization with application to aircraft design
Cordelier, Oihan, Diouane, Youssef, Bartoli, Nathalie, Laurendeau, Eric
Aircraft design relies heavily on solving challenging and computationally expensive Multidisciplinary Design Optimization problems. In this context, there has been growing interest in multi-fidelity models for Bayesian optimization to improve the MDO process by balancing computational cost and accuracy through the combination of high- and low-fidelity simulation models, enabling efficient exploration of the design process at a minimal computational effort. In the existing literature, fidelity selection focuses only on the objective function to decide how to integrate multiple fidelity levels, balancing precision and computational cost using variance reduction criteria. In this work, we propose novel multi-fidelity selection strategies. Specifically, we demonstrate how incorporating information from both the objective and the constraints can further reduce computational costs without compromising the optimality of the solution. We validate the proposed multi-fidelity optimization strategy by applying it to four analytical test cases, showcasing its effectiveness. The proposed method is used to efficiently solve a challenging aircraft wing aero-structural design problem. The proposed setting uses a linear vortex lattice method and a finite element method for the aerodynamic and structural analysis respectively. We show that employing our proposed multi-fidelity approach leads to $86\%$ to $200\%$ more constraint compliant solutions given a limited budget compared to the state-of-the-art approach.
- North America > United States > Virginia (0.04)
- North America > Canada (0.04)
- Europe > Germany (0.04)
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Learning-to-Defer with Expert-Conditioned Advice
Montreuil, Yannis, Montreuil, Leïna, Carlier, Axel, Ng, Lai Xing, Ooi, Wei Tsang
Learning-to-Defer routes each input to the expert that minimizes expected cost, but it assumes that the information available to every expert is fixed at decision time. Many modern systems violate this assumption: after selecting an expert, one may also choose what additional information that expert should receive, such as retrieved documents, tool outputs, or escalation context. We study this problem and call it Learning-to-Defer with advice. We show that a broad family of natural separated surrogates, which learn routing and advice with distinct heads, is inconsistent even in the smallest non-trivial setting. We then introduce an augmented surrogate that operates on the composite expert--advice action space and prove an $\mathcal{H}$-consistency guarantee together with an excess-risk transfer bound, yielding recovery of the Bayes-optimal policy in the limit. Experiments on tabular, language, and multi-modal tasks show that the resulting method improves over standard Learning-to-Defer while adapting its advice-acquisition behavior to the cost regime; a synthetic benchmark confirms the failure mode predicted for separated surrogates.
- Asia > Singapore (0.04)
- North America > United States > Georgia > Fulton County > Atlanta (0.04)
- Europe > Monaco (0.04)
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.04)
Agile Interception of a Flying Target using Competitive Reinforcement Learning
Gavin, Timothée, Lacroix, Simon, Bronz, Murat
The interception of agile aerial targets using autonomous drones is a challenging and increasingly relevant problem in robotics and security. The increasing presence of unmanned aerial vehicles (UAVs) in unauthorized, restricted airspaces poses significant safety and security risks and has spurred interest in developing effective interception strategies [1] In particular, scenarios such as airspace protection, infrastructure security, and event safety require the ability to capture or neutralize unauthorized drones with high precision and minimal collateral risk. Deploying interceptor drones equipped with nets is apromising approach, but it demandsadvanced control capabilities to match or exceed the agility of evasive targets. Traditional interception methods often rely on accurate models, preplanned strategies, or predictable target behaviour [2]. However, modern quadrotor drones can perform highly dynamic manoeuvres, and will actively evade capture, rendering their trajectories unpredictable and challenging the effectiveness of classical methods [3].
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.05)
- North America > United States > Florida > Palm Beach County > Boca Raton (0.04)
A Hybrid Tsallis-Polarization Impurity Measure for Decision Trees: Theoretical Foundations and Empirical Evaluation
Lansiaux, Edouard, Jairi, Idriss, Zgaya-Biau, Hayfa
We introduce the Integrated Tsallis Combination (ITC), a hybrid impurity measure for decision tree learning that combines normalized Tsallis entropy with an exponential polarization component. While many existing measures sacrifice theoretical soundness for computational efficiency or vice versa, ITC provides a mathematically principled framework that balances both aspects. The core innovation lies in the complementarity between Tsallis entropy's information-theoretic foundations and the polarization component's sensitivity to distributional asymmetry. We establish key theoretical properties-concavity under explicit parameter conditions, proper boundary conditions, and connections to classical measures-and provide a rigorous justification for the hybridization strategy. Through an extensive comparative evaluation on seven benchmark datasets comparing 23 impurity measures with five-fold repetition, we show that simple parametric measures (Tsallis $α=0.5$) achieve the highest average accuracy ($91.17\%$), while ITC variants yield competitive results ($88.38-89.16\%$) with strong theoretical guarantees. Statistical analysis (Friedman test: $χ^2=3.89$, $p=0.692$) reveals no significant global differences among top performers, indicating practical equivalence for many applications. ITC's value resides in its solid theoretical grounding-proven concavity under suitable conditions, flexible parameterization ($α$, $β$, $γ$), and computational efficiency $O(K)$-making it a rigorous, generalizable alternative when theoretical guarantees are paramount. We provide guidelines for measure selection based on application priorities and release an open-source implementation to foster reproducibility and further research.
- North America > United States > Wisconsin (0.04)
- Europe > France > Occitanie > Hérault > Montpellier (0.04)
The Sampling Complexity of Condorcet Winner Identification in Dueling Bandits
Saad, El Mehdi, Thuot, Victor, Verzelen, Nicolas
We study best-arm identification in stochastic dueling bandits under the sole assumption that a Condorcet winner exists, i.e., an arm that wins each noisy pairwise comparison with probability at least $1/2$. We introduce a new identification procedure that exploits the full gap matrix $Δ_{i,j}=q_{i,j}-\tfrac12$ (where $q_{i,j}$ is the probability that arm $i$ beats arm $j$), rather than only the gaps between the Condorcet winner and the other arms. We derive high-probability, instance-dependent sample-complexity guarantees that (up to logarithmic factors) improve the best known ones by leveraging informative comparisons beyond those involving the winner. We complement these results with new lower bounds which, to our knowledge, are the first for Condorcet-winner identification in stochastic dueling bandits. Our lower-bound analysis isolates the intrinsic cost of locating informative entries in the gap matrix and estimating them to the required confidence, establishing the optimality of our non-asymptotic bounds. Overall, our results reveal new regimes and trade-offs in the sample complexity that are not captured by asymptotic analyses based only on the expected budget.
- Europe > France > Occitanie > Hérault > Montpellier (0.04)
- North America > United States > New York (0.04)
- North America > Canada > British Columbia > Metro Vancouver Regional District > Vancouver (0.04)
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The Mediterranean is overdue a TSUNAMI: Scientists warn there's a 100% chance an enormous wave will hit the French Riviera in the next 30 years - as they call for urgent evacuation drills
Timothee Chalamet, Oscars laughing stock: All the brutal digs aimed at star after he missed out on Best Actor and'looked like he wanted to cry' A-list stars ditch formal Oscars red carpet dresses for sexy party looks - with Jeff Goldblum's wife Emilie Livingston, Heidi Klum, Amelia Gray Hamlin and Kate Hudson turning up the heat at Vanity Fair bash Teyana Taylor erupts backstage at Oscars after being'shoved' Chilling new details of dismembered Emily Pike's final hours after she was snatched in Arizona desert and man detectives now believe murdered her Dark truth about secret new filler treatment that uses tissue from DEAD PEOPLE... as doctors issue urgent warning Awful Timothee Chalamet's ego is bigger than Kylie's inflated butt... but it's so clear what's really going on here. Israel blows up Ayatollah Khamenei's personal jet amid claims his injured heir Mojtaba'has been flown to Moscow for treatment' Kate lets Diana take the spotlight: Princess skips Mother's Day post after emotional cancer message and Photoshop furore Baseball fans fume after'terrible' umpire error ends USA's controversial showdown with Dominican Republic in WBC semifinal How Oscars 2026 proved Hollywood has overdosed on Ozempic: Leading doctors name stars now at'extreme' risk... and reveal terrifying new side effects Trump warns of'very bad future' for Nato if his call for warships to police Strait of Hormuz is refused - hinting he could punish Ukraine Kim Kardashian struggles to WALK in skintight golden gown and towering'stripper heels' as she attends the Vanity Fair Oscars party Oscars presenter Kumail Nanjiani blasted for horrific Holocaust joke: 'Do not invite him back' Real reason Sean Penn skipped Oscars 2026... as disappointed fans blast his boycott'It's like he was possessed': Terrifying moment Alexander brother turned into a'monster' and raped me... and the four chilling words he said after horror attack - alleged victim claims Dubai'arrests foreign survivors of Iranian drone strike after they sent images of explosion aftermath to loved ones to prove they were safe' The Mediterranean is overdue a TSUNAMI: Scientists warn there's a 100% chance an enormous wave will hit the French Riviera in the next 30 years - as they call for urgent evacuation drills The French Riviera is famed for its sunny, year-round climate, azure waters and luxury resorts - but it'll be hit by a tsunami in the next 30 years, scientists predict. Experts say there is a '100 per cent' chance a great wave will form in the Mediterranean Sea in the next few decades. The tsunami could hit France's southern coastline in as little as 10 minutes from the trigger, causing chaos for tens of thousands of people who flock there during the summer months. While the country does have a national tsunami alert system, this only covers waves caused by distant earthquakes .
- Asia > Middle East > Iran (0.34)
- Atlantic Ocean > Mediterranean Sea (0.25)
- Asia > Middle East > UAE > Dubai Emirate > Dubai (0.24)
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- Information Technology > Artificial Intelligence > Robots > Autonomous Vehicles > Drones (0.54)