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

[hal-01354270] Towards Unambiguous Edge Bundling: Investigating Confluent Drawings for Network Visualization

Publications ENAC - Friday, 24 February 2017 - 15:29:12
In this paper, we investigate Confluent Drawings (CD), a technique for bundling edges in node-link diagrams based on network connectivity. Edge-bundling techniques are designed to reduce edge clutter in node-link diagrams by coalescing lines into common paths or bundles. Unfortunately, traditional bundling techniques introduce ambiguity since edges are only bundled by spatial proximity, rather than network connectivity; following an edge from its source to its target can lead to the perception of incorrect connectivity if edges are not clearly separated within the bundles. Contrary, CDs bundle edges based on common sources or targets. Thus, a smooth path along a...

[hal-01471666] A 3D Split-Step Fourier Algorithm Based on an Discrete Spectral Representation of the Propagation Equation

Publications ENAC - Thursday, 23 February 2017 - 15:40:23
A propagation method self-consistent in the discrete domain for the simulation of large distance scenarios in a 3D inhomogeneous atmosphere is proposed. First, a spectral representation of the field in a discrete 3D domain over an infinite perfect ground is introduced in cylindrical coordinates. A discrete spectral propagator is then derived. As in 2D methods, the inhomogeneous atmosphere is considered in the spatial domain using phase screens. An explicit numerical scheme is introduced. For directive sources, a sectoral propagation is proposed to reduce the computation time by limiting the computation domain. The method is tested by simulation scenarios involving...

[hal-01468674] Characterization and Applications of Temporal Random Walks on Opportunistic Networks

Publications ENAC - Tuesday, 21 February 2017 - 12:19:44
Opportunistic networks are a special case of DTNs that exploit systematically the mobility of nodes. When node contacts occur, routing protocols can exploit them to forward messages. In the absence of stable end-to-end paths, spatio-temporal paths are created spontaneously. Opportunistic networks are suitable for communications in pervasive environments that are saturated by other devices. The ability to self-organize using the local interactions among nodes, added to mobility, leads to a shift from legacy packet-based communications towards a message-based communication paradigm. Usually, routing is done by means of message replication in order to increase the...

[hal-01405290] Immersive solutions for future Air Traffic Control and Management

Publications ENAC - Friday, 17 February 2017 - 21:47:20
In this paper we review the activities of Air Tra c Control and Management (ATC/M) and expose scenarios that illustrate current and future challenges in this domain. In particular we look at those challenges that can be tackled with the use of immersion. We introduce the concepts of an immersive Remote Tower and Collaborative Immersive Trajectory analysis. These make use of immersive technologies such as Head Mounted Displays (HMDs) or large, tiled displays to immerse users in their tasks, better supporting the management and analysis of the complex data produced in this domain

[hal-01366998] Exploratory Study with Eye Tracking Devices to Build Interactive Systems for Air Traffic Controllers

Publications ENAC - Friday, 17 February 2017 - 21:46:38
While the mouse is the main input device for interacting with different screens, many alternatives do exist. In this article, we report our exploratory study with the usage of eyes as a new input device for Air Traffic Control systems. Our investigations, based on a user - centered design, include a study of the activity, a classification of interaction techniques based on eye tracking systems, and finally a working prototype with the evaluations of the developed interaction techniques. Our goal is to investigate gaze usages as a means of interaction, and give recommendations for future development of Air Traffic Control systems.

[hal-00987451] Interactive image-based information visualization for aircraft trajectory analysis

Publications ENAC - Friday, 17 February 2017 - 10:42:00
The objective of the presented work is to present novel methods for big data exploration in the Air Traffic Control (ATC) domain. Data is formed by sets of airplane trajectories, or trails, which in turn records the positions of an aircraft in a given airspace at several time instants, and additional information such as flight height, speed, fuel consumption, and metadata (e.g. flight ID). Analyzing and understanding this time-dependent data poses several non-trivial challenges to information visualization. Materials and methods: To address this Big Data challenge, we present a set of novel methods to analyze aircraft trajectories with interactive image-based information...

[hal-01078302] color tunneling:Interactive exploration and selection in volumetric datasets

Publications ENAC - Thursday, 16 February 2017 - 17:47:50
Interactive data exploration and manipulation are often hindered by dataset sizes. For 3D data, this is aggravated by occlusion, important adjacencies, and entangled patterns. Such challenges make visual interaction via common filtering techniques hard. We describe a set of real-time multi-dimensional data deformation techniques that aim to help users to easily select, analyze, and eliminate spatial and data patterns. Our techniques allow animation between view configurations, semantic filtering and view deformation. Any data subset can be selected at any step along the animation. Data can be filtered and deformed to reduce occlusion and ease complex data selections. Our...

[hal-01466629] A Multi-Replica Decoding Technique for Contention Resolution Diversity Slotted Aloha

Publications ENAC - Thursday, 16 February 2017 - 02:05:24
This paper proposes a new method for data reception over a random access channel in a satellite communication system. The method is called Multi-replicA decoding using corRelation baSed locALisAtion (MARSALA). It uses the same transmission scheme as in Contention Resolution Diversity Slotted Aloha (CRDSA) where each user sends several replicas of the same packet over the frame. MARSALA is a new decoding technique that localises all the replicas of a packet using a correlation based method, then combines them to decode the data. With MARSALA, the system can achieve a normalized throughput higher than 1.2, resulting in a significant gain compared to CRDSA, while adding a...

[hal-01466635] Blind estimation of unknown time delay in periodic non-uniform sampling: Application to desynchronized time interleaved-ADCs

Publications ENAC - Thursday, 16 February 2017 - 02:05:24
Increasing the sampling rate of Analog-to-Digital Converters (ADC) is a main challenge in many fields and especially in telecommunications. Time-Interleaved ADCs (TI-ADC) were introduced as a technical solution to reach high sampling rates by time interleaving and multiplexing several low-rate ADCs at the price of a perfect synchronization between them. Indeed, as the signal reconstruction formulas are derived under the assumption of uniform sampling, a desynchronization between the elementary ADCs must be compensated upstream with an online calibration and expensive hardware corrections of the sampling device. Based on the observation that desynchronized TI-ADCs can be...

[hal-01465993] Survey on UAANET Routing Protocols and Network Security Challenges

Publications ENAC - Wednesday, 15 February 2017 - 16:06:04
UAV Ad hoc Networks (UAANETs) is a subset of the well-known mobile ad hoc network (MANET) paradigm. It refers to the deployment of a swarm of small Unmanned Aerial Vehicles (UAVs) and Ground Control Stations (GCS). These UAVs collaborate in order to relay data (command and control traffic and remotely sensed data) between each other and to the Ground Control Station (GCS). Compared to other types of ad hoc networks, UAANETs have some unique features and bring several major challenges to the research community. One of these is the design of UAANET routing protocol. It must establish an efficient route between UAVs and adjust in real time to the rapidly changing topology....
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