Archives Ouvertes HAL

Toutes les publications de l'ENAC en direct.
All ENAC publications.

[hal-01886536] Design of a novel network intrusion detection system for drone communications

Publications ENAC - Mercredi, 10 octobre 2018 - 16:34:14
This paper proposes an hybrid method based on both a spectral traffic analysis and a robust controller / observer for anomaly estimation inside UAV networks. This method is based on both Lyapunov Krasovskii functional and dynamic behavior of Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). The proposed hybrid method considers, as a preliminary step, a statistical signature of the traffic exchanged in the network. By looking up this signature in a bank of signatures, it is possible to characterize the different anomalies that can be observed in UAV networks. Consequently, the different signatures that we can process, based on the different types of...

[hal-01852144] On the geodesic distance in shapes K-means clustering

Publications ENAC - Mardi, 9 octobre 2018 - 18:44:03
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-01876486] The Cyclic Job Shop Problem with uncertain processing times

Publications ENAC - Mardi, 9 octobre 2018 - 18:29:53
Most models for scheduling problems assume deterministic parameters. In contrast, real world scheduling problems are often subject to many sources of uncertainty, for example activities duration can decrease or increase, machines can break down, new activities can be incorporated, etc. In this paper, we focus on scheduling problems that are cyclic and where activity durations are affected by uncertainty. Indeed, the best solution for a deterministic problem can quickly become the worst one in the presence of uncertainties. In this paper, we consider the Cyclic Job Shop Problem (CJSP) where processing times are affected by uncertainty. Several studies were conducted on...

[hal-01887290] Synchronization of Traffic Flow and Sector Opening for Collaborative Demand and Capacity Balancing

Publications ENAC - Mardi, 9 octobre 2018 - 17:57:43
This paper proposes a method to synchronize traffic flow optimization and sector opening scheduling, with the aim of achieving flexible demand and capacity balancing (DCB). Delay assignment, trajectory options and sector collapsing are used to manage the traffic demand, while sector opening schemes are to affect the airspace capacity. Mixed Integer Programming (MIP) model is built to incorporate these initiatives. Three model variants are presented to illustrate the synchronization process, and their results in a real-world case study demonstrate some promising improvements for the DCB performances. Index Terms-air traffic flow management, trajectory options, dynamic...

[hal-01888558] Interval Observers for Secure Estimation in Cyber-Physical Systems

Publications ENAC - Vendredi, 5 octobre 2018 - 20:57:05
Stealthy attacks on the sensors and actuators embedded in cyber-physical systems could hinder the safe operation of these systems if the state estimators monitoring them cannot detect such attacks in time. In this paper, we study stealthy attacks in the framework of interval observers. We consider two classes of attacks: when a malicious agent compromises the sensors and when it is able to alter the system's actuators. For each type of attack, we design a dedicated interval observer for the system's state and we construct bounds for the attack signal. We investigate the ability of such interval observer to provide accurate estimates when the system is under the attack....

[hal-01882721] Totem de Personnalisation : Conception d'une Interface Tangible pour le Choix de Parcours de Visite dans les Musées

Publications ENAC - Vendredi, 5 octobre 2018 - 20:56:59
De nos jours, les musées doivent rivaliser avec le marché du divertissement pour attirer un large public. Une solution envisagée pour les rendre plus attractifs tient dans la personnalisation des parcours de visite en fonction des préférences des visiteurs. En se basant sur l'analyse des besoins réalisée auprès de cinq musées, nous avons conçu cinq storyboards d'interface permettant à un groupe de visi-teurs de choisir un parcours en fonction de leurs personnal-ités et envies. Nous avons également identifié grâce à cette analyse, ainsi que la littérature, douze exigences qui nous ont permis d'évaluer les solutions proposées. Enfin, nous avons conçu un prototype basse...

[tel-01883743] Ballstering: un algorithme de clustering dédié à de grands échantillon

Publications ENAC - Jeudi, 4 octobre 2018 - 17:23:59
Ballstering appartient à la famille des méthodes de machine learning qui ont pour but de regrouper en classes les éléments formant la base de données étudiée et ce sans connaissance au préalable des classes qu'elle contient. Ce type de méthodes, dont le représentant le plus connu est k-means, se rassemblent sous le terme de "partitionnement de données" ou "clustering". Récemment un algorithme de partitionnement "Fast Density Peak Clustering" (FDPC) paru dans le journal Science a suscité un intérêt certain au sein de la communauté scientifique pour son aspect innovant et son efficacité sur des données distribuées en groupes non-concentriques...

[hal-01887622] Bioinspired wind field estimation—part 1: Angle of attack measurements through surface pressure distribution

Publications ENAC - Jeudi, 4 octobre 2018 - 16:18:15
One of the major challenges of Mini-Unmanned Aerial Vehicle flight is the unsteady interaction with turbulent environment while flying in lower levels of atmospheric boundary layer. Following inspiration from nature we expose a new system for angle of attack estimation based on pressure measurements on the wing. Such an equipment can be used for real-time estimation of the angle of attack during flight or even further building of wind velocity vector with additional equipment. Those information can find purpose in control and stabilization of the aircraft due to inequalities seen by the wing or even for various soaring strategies that rely on active control for energy...

[hal-01871297] Fake news ∩ mathleaks

Publications ENAC - Mardi, 2 octobre 2018 - 18:58:49
Utiliser la désinformation pour améliorer la formation mathématique des futurs bacheliers ? Profiter les failles de notre société ? Faisant feu de tout bois, c'est l'idée originale des auteurs qui, en forme de clin d'oeil, expliquent comment exploiter les fake news pour le plus grand bien mathématique de nos élèves. Chaque année on appréhende une fuite du sujet du bac qui pourrait remettre en question le travail des collègues ayant préparé le sujet mais surtout celui des centaines de milliers de lycéens de terminale susceptibles d'être alors victimes d'une injustice, voire de devoir composer une seconde fois avec tous les coûts (y compris humains) que cela représente....

[hal-01878172] Interactive obstruction-free lensing for volumetric data visualization

Publications ENAC - Jeudi, 27 septembre 2018 - 15:58:49
Occlusion is an issue in volumetric visualization as it prevents direct visualization of the region of interest. While many techniques such as transfer functions, volume segmentation or view distortion have been developed to address this, there is still room for improvement to better support the understanding of objects' vicinity. However, most existing Focus+Context fail to solve partial occlusion in datasets where the target and the occluder are very similar density-wise. For these reasons, we investigate a new technique which maintains the general structure of the investigated volumetric dataset while addressing occlusion issues. With our technique, the user...
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