Archives Ouvertes HAL
Toutes les publications de l'ENAC en direct.
All ENAC publications.
[hal-05151171] TOWARD UNDERSTANDING INTRA-USER VARIABILITY IN BCI: A MULTI-SESSION, MULTI-CONTEXT EXPERIMENTAL PROTOCOL
This study, presented orally at the conference, introduces an experimental protocol designed to investigate intra-user variability in EEG-based Brain-Computer Interfaces (BCIs). Over six sessions alternating between mornings and afternoons, participants performed three mental tasks under two different interface contexts (low vs. high stimulation). Psychological and user-experience data were collected through questionnaires. Preliminary results from three participants show no consistent effect of psychological state or time of day on BCI performance, but a significant context effect for one user. This protocol aims to better understand and model the complex dynamics...
[hal-04250022] Deviation results for Mandelbrot's multiplicative cascades with (stretched) exponential tails
Let $W$ be a nonnegative random variable with expectation $1$. For all $r \geqslant 2$, we consider the total mass $Z_r^\infty$ of the associated Mandelbrot multiplicative cascade in the $r$-ary tree. For all $n \geqslant 1$, we also consider the total mass $Z_r^n$ of the measure at height $n$ in the $r$-ary tree. Liu, Rio, Rouault \cite{lrr,liu2000limit,Rouault04} established large deviation results for $(Z_r^n)_{r \geqslant 2}$ for all $n \in \intervallentfo{1}{\infty}$ (resp.\ for $n = \infty$) in the case $W$ has an everywhere finite cumulant generating function $\Lambda_W$ (resp.\ $W$ is bounded). Here, we extend these results to the case that $\Lambda_W$ is only...
[hal-05147698] Partitionnement de Graphe pour l'Identification de Goulots d'Étranglement Partagés
Un réseau IP peut être représenté sous la forme d'un graphe où les noeuds sont des routeurs et les arêtes des liens de communication IP. Ce graphe aide à analyser les interactions et les flux d'information au sein du réseau. Chaque routeur, agissant comme une file d'attente, gère le trafic avec une capacité de mémoire tampon et un débit de sortie. Lorsque le trafic entrant dépasse cette capacité, une congestion se produit, dégradant le service. Identifier ces goulots d'étranglement est crucial pour évaluer la performance du réseau. Cet article explore une méthode de partitionnement de graphe permettant de regrouper les flux partageant un goulot commun à l'aide d'un modèle...
[hal-05081071] From Laboratory to Cockpit: Evaluating the Predictive Value of Cognitive Tasks on Flight Simulator Performance
Comprehending the cognitive mechanisms underpinning success in demanding daily tasks is imperative for the human factors field. It not only necessitates a foundational grasp of the human brain but also furnishes invaluable insights for managing and averting human errors. This is particularly true in critical systems such as airplane, surgery, and more recently with autonomous vehicles. In order to provide additional information of the link between flying activity and high level cognitive functions, we investigated the relations between common executive function task performance, more complex and ecological task performance and flight simulator performance. Our results...
[hal-05138511] Spherical and Plane Waves Propagation through a Realistic Turbulent Marine Layer
<div><p>In this paper, the impact of a realistic turbulent medium obtained from fluid mechanics equations on radiowave propagation is studied. The realistic medium contains more structured variations of refractive index than the one usually generated from Gaussian-like spectra. The impact on propagation is illustrated by comparing the effect on sources presenting both a spherical and a plane wavefront. These results highlight the impact of the localised atmospheric structure that could reveal an underestimation of the turbulence impact when obtained via the commonly used Gaussian-like spectra.</p></div>
[tel-05136612] Dynamic optimization of multimodal passenger mobility
Multimodal transportation represents an innovative approach to contemporary mobility challenges in logistics and transportation. By skillfully integrating different modes of transportation, multimodal transportation provides a comprehensive and efficient solution to the need to move goods and people. The synergistic combination of different modes of transportation creates complex, interdependent multimodal networks, where the failure of a single element can have a significant impact on the entire network. This thesis focuses on the analysis of the vulnerability of transportation systems to disruptions, and proposes a topological approach aimed at guaranteeing the minimum...
[hal-05134630] Hierarchical Modeling and Architecture Optimization: Review and Unified Framework
Simulation-based problems involving mixed-variable inputs frequently feature domains that are hierarchical, conditional, heterogeneous, or tree-structured. These characteristics pose challenges for data representation, modeling, and optimization. This paper reviews extensive literature on these structured input spaces and proposes a unified framework that generalizes existing approaches. In this framework, input variables may be continuous, integer, or categorical. A variable is described as meta if its value governs the presence of other decreed variables, enabling the modeling of conditional and hierarchical structures. We further introduce the concept of partially...
[hal-05134017] IMMERCOG: Impact of Extreme Environments on Remote Operations in Critical Systems
Remote operation technologies play a critical role in fields such as medicine, defense, and space exploration, yet existing research often relies on controlled laboratory simulations that fail to capture the complexities of real-world environments. This doctoral project, IMMERCOG, investigates the impact of extreme conditions—such as underwater environments and real flight—on the psychophysiological states and performance of operators controlling remote systems. This research bridges the gap between controlled studies and real-world applications, aiming to advance human-machine interaction (HMI) for remote operations under stress.The project involves three experimental...
[hal-05133250] On the Wasserstein geodesic principal component analysis of probability measures
This paper focuses on Geodesic Principal Component Analysis (GPCA) on a collection of probability distributions using the Otto-Wasserstein geometry. The goal is to identify geodesic curves in the space of probability measures that best capture the modes of variation of the underlying dataset. We first address the case of a collection of Gaussian distributions, and show how to lift the computations in the space of invertible linear maps. For the more general setting of absolutely continuous probability measures, we leverage a novel approach to parameterizing geodesics in Wasserstein space with neural networks. Finally, we compare to classical tangent PCA through various...
[hal-05087702] A bi-level co-design approach for multicopters
Over the last few decades, multicopters have become significantly popular because of their various applications. However, multicopters suffer from poor endurance performance as compared to other aircraft configurations with lifting surfaces. In this paper, a co-design approach for the multicopter structure and propulsive system is presented with the objective of improving the energetic efficiency of the vehicle, while respecting dynamic performance requirements. For this purpose, the approach uses a bi-level formulation to optimize concurrently the design and the control. The methodology offers the possibility to activate or not a passive fault tolerant strategy in the...