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Using Cardiac and Electrodermal Activity as Cognitive Markers for Interruptions and Distraction in a Surveillance Simulation
No full textInternational audienceSecurity surveillance is frequently used to increase public safety. Characteristics of the surveillance rooms, however, pose many cognitive challenges pertaining to distraction and interruptions, which may affect surveillance performance. Affective computing could represent a potential solution. It involves the recognition and the interpretation of human states using, for instance, different psychophysiological measures. As a first step toward this goal, the present study aimed at assessing whether cardiac and electrodermal activity, could be used as potential markers of interruptions and distraction during a surveillance simulation. A total of 126 participants went through a simulation involving four 8-min scenarios using a high-fidelity urban security surveillance microworld. Task interruption in the form of a realistic secondary task to perform and distraction in the form of background noise representative of a busy operational centre were also implemented into the simulation. Different features of the electrocardiographic (ECG) signal varied with the presence of distraction, but also as a function of time on task. Electrodermal (EDA) features mainly varied as a function of time. These results suggest that distraction and time on task specifically impacted cognitive functioning, potentially increasing sympathetic activity through cognitive workload, and that EDA and ECG measures may represent relevant markers to use from an affective computing perspective to particularly pinpoint periods of distraction and hypovigilance. Implications for the development of user-adaptive systems are discussed
Ensuring silent communication between light aviation pilots and air traffic control: a new multimodal communication device
No full textInternational audienceIn the context of light aviation in controlled airspace, airborne communication between pilots and Air Traffic Control (ATC) is at present only ensured orally via a radio channel. This presents limitations to both security (failure of radio, bad audio quality) and accessibility for Hearing or Speaking Impaired (HSI) pilots. Our objective is to develop a Human-Machine Interface (HMI) ensuring silent communication between pilots and ATC. Hence, we developed a device combining sight and touch, which consists of a tablet placed on the upper left side of the cockpit and a vibrating vest worn by pilots. The tablet enables bidirectional communication with ATC, and receiving information from the Automatic Terminal Information Service (ATIS). The vest notifies pilots when a new message is received. This way, pilots can focus their visual attention on the onboard instruments and outside environment. Based on theinitiative from the FANS4ALL association, we have preliminary results using an application case centered on two HSI pilots. They both completed a simulator flight scenario under (i) a control condition with a hearing copilot in charge of oral communication, (ii) an experimental condition using our HMI to handle communications autonomously. We evaluated the HMI efficiency regarding diverse variables: acceptance, usability, flight performance, situational awareness, mental workload, reaction time to the vest’s vibration and time to write a message on the tablet. While some results highlighted the need for HMI improvements (enhanced mental workload, reduced situational awareness and slightly reduced flight performance), others are encouraging (acceptable usability, reaction time < 5 seconds, time to write a message ≤ 8seconds). This initial work paves the way for new, quieter and safer means of communication between ATC and pilots. We foresee evaluations with a larger panel of both HSI and hearing pilots to confirm and pursue these preliminary results
Electromagnetic wave propagation through realistic inhomogeneous turbulence
No full textInternational audienceThe Marine Atmospheric BoundaryLayer (MABL) is an intricate environment where di-verse atmospheric phenomena can affect electromagnetic(EM) systems. The stochastic multiple phase screenmethod (sMPS) is conventionally used to model the im-pact of tropospheric turbulence on EM wave propagation.It often relies on the use of homogeneous Kolmogorovspectra. This study presents two original methods forgenerating inhomogeneous turbulence with sMPS. TheLES-Kolmogorov approach uses accurate turbulent struc-ture constant profiles directly extracted from atmosphericsimulations, while the Bump-Kolmogorov method (BK-model) approximately replicates it with a parametricmodel. Log-amplitude profiles computations highlightthe specific impact of turbulence inhomogeneity. Theproposed methods show good agreements, suggesting thefeasibility of an accurate parametric replication of turbu-lence in the MABL
H2020 Projet HERON
No full textInternational audienceSCOPE : HERON is among the projects funded by the EU under the H2020 program for road infrastructure maintenance. Within HERON's scope is the implementation of a road infrastructure plan,CONTEXT : The Forever Open Road (FOR) concept has been developed, with its national declinations (R5G in France for example) by the association of European Road Research Laboratories (FEHRL). HERON answers the three concepts of FOR, namely the resilient, the automated and the adaptable road (www.foreveropenroad.eu/). As outlined by FOR, HERON integrates existing technical components, including off-the-shelf technologies and outcomes from previous or ongoing research projects.GOAL : The goal of HERON is to develop an integrated automated system capable of conducting various road maintenance and improvement tasks, such as crack sealing, pothole patching, asphalt rejuvenation, autonomous replacement of Removable Urban Pavement (RUP) elements, and road marking/painting. Thus, HERON is tasked with supporting both pre- and post-intervention phases, which involve automated and controlled visual inspections, as well as the placement and removal of traffic cones
À quel point la réaffectation asynchrone de poids est-elle difficile ?
No full textInternational audienceQuorum systems are fundamental abstractions employed to design fault-tolerant and available distributed protocols. While the regular majority quorum system is commonly employed due to its simplicity and optimal fault tolerance, it falls short in addressing the dynamic and heterogeneous nature of practical systems. This limitation becomes evident in protocols such as the ones deployed in wide-area networks, where nodes exhibit diverse performance, or those used in blockchain and decentralized payment systems, where nodes' stakes or reputations vary over time. Presenting a dynamic weighted variant of this quorum system effectively addresses these challenges but introduces a new fundamental problem: how hard is it to reassign weights? We answer this question after formalizing the weight reassignment problem in this work.Specifically, we prove that reassigning weights is as hard as solving consensus, \emph{i.e.}, it cannot be implemented in asynchronous failure-prone distributed systems.Les systèmes de quorum sont des abstractions fondamentales utilisées pour concevoir des protocoles distribués tolérants aux pannes et disponibles. Bien que le système de quorum majoritaire soit couramment utilisé en raison de sa simplicité et de sa tolérance optimale aux pannes, il ne parvient pas à saisir la nature dynamique et hétérogène des systèmes réels. Cette limitation devient évidente dans les services géo-distribués, où les nœuds présentent des performances hétérogènes, ou dans les services basés sur une blockchain ainsi que les systèmes de paiement décentralisés, où les enjeux ou la réputation des nœuds varient au fil du temps. La présentation d’une variante pondérée et dynamique de ce système de quorum répond efficacement à ces enjeux mais introduit un nouveau problème fondamental : à quel point est-il difficile de réattribuer les poids? Nous répondons à cette question après avoir formalisé le problème de réaffectation de poids dans ce travail. Plus précisément, nous prouvons que la réattribution des poids est aussi difficile que la résolution d'un consensus, c'est-à-dire que cela ne peut pas être implémenté dans des systèmes distribués asynchrones sujets aux pannes
A Reactive System-specific Compilation Chain from Synchronous Dataflow Models to FPGA Netlist
No full textInternational audienceModern Field Programmable Gate Arrays (FPGAs)offer a solution to several issues related to real-time on-boardsystems, such as guaranteed execution time. They are currentlyconsidered as target platforms for space applications. However, the complexity of producing circuits on these componentsposes a challenge to their widespread adoption. To addressthis issue, high-level synthesis tools provide another layer ofabstraction above the logic circuit design process, for examplecompiling C code into Hardware Description Languages suchas VHDL or Verilog. However, high-level synthesis results arepoorly predictable and do not guarantee the efficient use ofrecent FPGA capabilities provided by new primitives like digitalsignal processor or random-access memory. In this paper wepropose a compilation chain dedicated to reactive systems, ie.controllers, providing a more predictable synthesis process forcritical embedded control applications. The implemented solutiondemonstrates timing performance equivalent to the traditionalsynthesis process with a more predictable result
VTOL site location considering obstacle clearance during approach and departure
No full textInternational audienceUrban air mobility (UAM) extends urban transportation to low-altitude airspace using electric vertical take-off and landing (eVTOL) vehicle to reduce traffic congestion. The vertical take-off and landing (VTOL) site connecting ground and air transport is the critical infrastructure of the UAM. Determining its locations is essential for the design and operation of the air route. This study focuses on the problem of the location of the VTOL site, using Shenzhen as the study area, and establishes an integer programming model with the objective of maximizing travel cost savings to identify the optimal locations of the VTOL sites. This study is different from existing ones in that it explicitly considers the three-dimensional spatial availability of VTOL sites. Geographic information system (GIS) tools are used to identify locations that satisfy two-dimensional (2D) planar availability, and an obstacle assessment model of the approach/departure and transitional surfaces of the VTOL site is built to further screen the locations. The selected potential sites are used as input to the integer programming model, ensuring that the locations identified to establish the VTOL site are optimal. The impact of the number of VTOL sites, the user's transfer time at the VTOL sites, and the eVTOL pricing on the model solution is also discussed. Although this study uses Shenzhen as a research object, the proposed methodology is generalized and applicable to any other city or region, providing recommendations and references for initial planning and related operations of the UAM in selected areas
On the asymptotic performance of time-delay and Doppler estimation with a carrier modulated by a band-limited signal
No full textInternational audienceTime-delay and Doppler estimation is crucial in various engineering fields, as estimating these parameters constitutes one of the key initial steps in the receiver’s operational sequence. Due to its importance, several expressions of the Cramér–Rao Bound (CRB) and Maximum Likelihood Estimation (MLE) have been derived over the years. Previous contributions started from the assumption that the transmission process introduces an unknown phase, which hindered the explicit consideration of the time-delay parameter in the carrier-phase component in theoretical derivations. However, this contribution takes into account this additional term under the assumption that such an unknown phase is inferred and compensated for. This new condition leads to the derivation of a novel MLE. Subsequently, a closed-form expression of the achievable Mean Squared Error (MSE) for the time-delay and Doppler parameters is provided for the asymptotic region, assuming the signal is band-limited. Both expressions are validated via Monte Carlo simulations. This analysis reveals five distinct regions of operation of the MLE, refining existing knowledge and providing valuable insights into time-delay estimatio
Espace de Conception et Analyse Critique des Interfaces de Pilote Automatique
No full textNational audienceAutopilot interfaces are designed to help aircrews maintain awareness about the aircraft's current automation mode, the lack of which can lead to fatal accidents. However, even though researchers have identified multiple design flaws, cockpit designs remain largely unchanged. We first review the research literature on autopilot design, with a special emphasis on addressing mode awareness in order to create a design space that characterizes autopilot interfaces. We next follow a generative design approach that analyzes and critiques three existing commercial autopilot interfaces with respect to this design space so as to identify their gaps and limitations. We then extend the design space to include additional design dimensions and conclude by suggesting directions for improving future autopilots.Les interfaces de pilotage automatique sont conçues pour aider l'équipage à rester conscients du comportement de l'avion, car un manque de cette conscience peut entraîner des accidents graves. Malgré l'identification de défauts de conception, leurs interfaces restent largement inchangées. Nous passons d'abord en revue les travaux de la littérature sur les conceptions de pilotes automatiques afin de créer un espace de conception qui les caractérise. Notre approche de conception générative a guidé l'analyse et la critique de trois cockpits commerciaux existants, conduisant à l'identification de leurs limites. Enfin, nous avons étendu le design space avec de nouvelles dimensions, suggérant ainsi des directions futures pour la conception des interfaces d'autopilotage
From Laboratory to Cockpit: Evaluating the Predictive Value of Cognitive Tasks on Flight Simulator Performance
No full textInternational audienceComprehending 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 suggest that the unitary nature and lack of real-life legitimacy of common laboratory executive function tasks limit their ability to explain flight performance in the simulator —except for set shifting. Conversely, more ecological and dynamic tasks that engage executive functions tend to explain a larger variance in flying activity. Further research is planned to refine these predictive models and understand the underlying cognitive mechanisms.<br /