Archives Ouvertes HAL
Toutes les publications de l'ENAC en direct.
All ENAC publications.
[hal-01852144] On the geodesic distance in shapes K-means clustering
Using Information Geometry tools, we represent landmarks of a complex shape as probability densities in a statistical manifold. Then, in the setting of shapes clustering through a K-means algorithm, we evaluate the discriminative power of two different shapes distances. The first, derived from Fisher-Rao metric, is related with the minimization of information in the Fisher sense and the other is derived from the Wasserstein distance which measures the minimal transportation cost.
[hal-01609764] Propagation 3D par méthode spectrale pour la prédiction de la couverture de systèmes radar
Dans le domaine du radar, il existe un fort besoin en modélisation électromagnétique pour prédire la couverture des systèmes. Ces outils de modélisation se veulent de plus en plus précis en prenant en compte des phénomènes de plus en plus complexes. Le présent article présente un outil de simulation qui permet une modélisation des effets de propagation 3D par une méthode spectrale de type split-step.
[hal-01849420] Bayesian Inference of GNSS Failures
The probability of failure (failure rate) is a key input parameter to integrity monitoring systems used for safety, liability or mission critical applications. A standard approach in the design of Global Positioning System (GPS) integrity monitoring is to utilize the service commitment on the probability of major service failure, often by applying a conservative factor. This paper addresses the question of what factor is appropriate by applying Bayesian inference to real and hypothetical fault histories. Global Navigation Satellite System (GNSS) anomalies include clock or signal transmission type faults which are punctual (may occur at any time) and incorrect ephemeris...
[hal-01823248] An Exploratory Study of the Uses of a Multisensory Map—With Visually Impaired Children
This paper reports an empirical study of a multisensory map used by visually impaired primary school pupils, to study human habitats and differences between urban, suburban and rural areas using a local example. Using multimodal analysis, we propose to examine how the use of smell and taste shape pupils' engagement and the development of a non-visual knowledge of geography. Our research questions include: How do pupils try to make sense of this unusual material, in conjunction with the tactile, audio and tangible material used in this lesson? How does the special education teacher support the development of these interpretations? Multisensory material has the potential...
[hal-01609755] Comparison of Nx2D and 3D Split-Step Fourier Methods in Realistic 3D Ducting Conditions
A 3D split-step Fourier method is presented and tested. It is based on a spectral representation of the discrete wave equation in cylindrical coordinates. The formulations in this method are self-consistent in the discrete domain. This method is applied to simulate the propagation with ducts retrieved after clutter data inversion. In the numerical tests, the difference between N × 2D and 3D models is not significant. Thus, in this case, considering the 3D atmosphere effects is unnecessary.
[hal-01022511] Legible, are you sure ? An experimentation-based typographical design in safety-critical context
Designing Safety-critical interfaces entails proving the safety and operational usability of each component. Largely taken for granted in everyday interface design, the typographical component, through its legibility and aesthetics, weighs heavily on the ubiquitous reading task at the heart of most visualizations and interactions. In this paper, we present a research project whose goal is the creation of a new typeface to display textual information on future aircraft interfaces. After an initial task analysis leading to the definition of specific needs, requirements and design principles, the design constantly evolves from an iterative cycle of design and...
[hal-01761909] Cardiovascular correlates of emotional state, cognitive workload and time-on-task effect during a realistic flight simulation
In aviation, emotion and cognitive workload can considerably increase the probability of human error. An accurate online physiological monitoring of pilot's mental state could prevent accidents. The heart rate (HR) and heart rate variability (HRV) of 21 private pilots were analysed during two realistic flight simulator scenarios. Emotion was manipulated by a social stressor and cognitive workload with the difficulty of a secondary task. Our results confirmed the sensitivity of the HR to cognitive demand and training effects, with increased HR when the task was more difficult and decreased HR with training (time-on-task). Training was also associated with an increased HRV...
[hal-01850862] Comments on the computation of multiple Lyapunov-like functions for switched hybrid systems
This note exposes false claims of Zheng et al., "Computing multiple Lyapunov-like functions for inner estimates of domains of attraction of switched hybrid systems," Int. J. Robust Nonlinear Control 2018.
[hal-01843724] Human-Machine Interaction Assessment by Neurophysiological Measures: A Study on Professional Air Traffic Controllers
This study aims at investigating the possibility to employ neurophysiological measures to assess the human - machine interaction effectiveness . Such a measure can be used to compare new technologies or solutions, with the final purpose to enhance operator’s experience and increase safety. I n the present work, two different interaction modalities (Normal and Augmented) related to Air Traffic Management field have been compared , by involving 10 professional air traffic controllers in a control tower simulated environment . Experimental task consisted in locating aircrafts in different airspace positions by using the sense of hearing. In one modality (i.e. “Normal”), all...
[hal-01839265] Generation of Optimal Smooth Trajectories using Bezier Curves for Transport Aircraft
With the increase in air traffic, new concepts have been introduced to organize and better manage air traffic flows (free flight, air-corridors, airstreams) with the view of increasing traffic safety and airspace capacity by solving air traffic conflicts. Hence the need of ad-hoc descriptions and parametrization of more complex and flexible transport aircraft trajectories with new characteristics, allowing high traffic densities as well as limiting environmental impact (noise). In the first part of this paper the motivation and trajectory generation problem for transportation aircraft is introduced, and a state of the art with respect to transportation aircraft...