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Attentional Orienting in Front and Rear Spaces in a Virtual Reality Discrimination Task
No full textInternational audienceRecent studies on covert attention suggested that the visual processing of information in front of us is different, depending on whether the information is present in front of us or if it is a reflection of information behind us (mirror information). This difference in processing suggests that we have different processes for directing our attention to objects in front of us (front space) or behind us (rear space). In this study, we investigated the effects of attentional orienting in front and rear space consecutive of visual or auditory endogenous cues. Twenty-one participants performed a modified version of the Posner paradigm in virtual reality during a spaceship discrimination task. An eye tracker integrated into the virtual reality headset was used to make sure that the participants did not move their eyes and used their covert attention. The results show that informative cues produced faster response times than non-informative cues but no impact on target identification was observed. In addition, we observed faster response times when the target occurred in front space rather than in rear space. These results are consistent with an orienting cognitive process differentiation in the front and rear spaces. Several explanations are discussed. No effect was found on subjects’ eye movements, suggesting that participants did not use their overt attention to improve task performance
Impact of DME/TACAN on GNSS L5/E5a Receivers at Low Altitude Considering Multipath
No full textInternational audienceIn the context of civil aviation, GNSS L5/E5a Radio Frequency Interference (RFI) environment is dominated by pulsed interferences such as JTIDS/MIDS and DME/TACAN causing a degradation of the effective C/N_0 observed by the receiver. The mitigation of the pulse RFI as well as its precise characterization is fundamental to guarantee the provision of the civil aviation Safety-of-Life service. In order to mitigate the pulsed RFI impact, in civil aviation standards, a temporal blanker is used as a counter measure. The effective C/N_0 is thus computed accounting for the temporal blanker introduction through the derivation of the blanker duty cycle, bdc, and the equivalent noise level contribution of the non-blanked interference, R_I.However, none of the characterizations found in the scientific literature or in the standards considers any multipath effect. This effect is especially important at low altitude since the airborne GNSS receiver could be significantly affected by echoes created by low altitude obstacles, potentially increasing bdc and R_I. Therefore, in this work, it is proposed to update the mathematical model of the effective C/N_0 with the introduction of multipath.The introduction of this new model is used to compare the impact of multipath at low and at high altitude flight levels (FL). The comparison is conducted in two parts in this work. First, an analysis shows that to increase the blanking duty cycle by 50%, the size of an obstacle should be four times larger when the aircraft is at high altitude FL in comparison with low altitude FL. Second, an analysis of a potential low altitude hot-spot located at JALTO, Philadelphia, shows that the impact of multipath must not be neglected; nevertheless, it is shown that the low altitude hot spot exceeding the existing worst-case scenario at FL400 is highly unlikely
Metropolis II: Benefits of Centralised Separation Management in High-Density Urban Airspace
No full textInternational audienceThe Metropolis II project aimed to study the impact of centralised separation management for urban aerial mobility. Three concepts were developed in this study: a fully centralised, strategically separated concept, a hybrid concept featuring centralised strategic separation and distributed tactical separation, and a fully distributed tactical concept. A comparative simulation study was performed, using traffic scenarios based on predicted demand in an urban airspace in the city of Vienna. Simulations were performed with varying traffic densities and situations. Results show that the purely strategic and purely tactical strategies perform comparably in terms of safety, and that further improvements can be achieved with a combination of those strategies
Interactions humain-machine maximisant la sécurité lors de la préparation des missions de drones : cas de la catégorie d'exploitation spécifique
No full textDrones provide important benefits to humanity, for example, as agile and efficient support during emergency management or natural disasters, enabling faster delivery of medical supplies to remote locations, or accelerated acquisition of large amounts of data useful for science and economics. Unmanned aircraft are easier to deploy and cheaper to build, operate and maintain than conventional aviation aircraft. Of all the applications of drones, those that will produce a significant positive impact on society will be primarily out of sight of the remote pilot. However, this mode of operation increases the level of risk associated with operations.Before operations can be carried out, safety studies will have to be carried out by the operators. Then, they will have to request operating authorization from a competent authority, which will verify and validate the level of safety envisaged. These risk studies are time-consuming and rely on a complex methodology called Specific Operation Risk Assessment. Moreover, the number of missions of this type is expected to increase significantly in the coming years, at the same time as the number of drone operations is expected to increase.How then can we make it more usable to conduct safety studies and apply for authorization to operate drone missions, while maximizing safety?Through a systematic review of the literature, we compile existing contributions in HMI. We classify the interactions according to the tasks performed, the flight phase, and the use of map representations.Collected design recommendations are synthesized. However, these interactions are most often applied during the execution phase and much less during the preparation phase which represents most of the time of a mission and during which the tasks of safety analysis and authorization request are performed. The use of maps to represent the operation is also widely studied during the execution phase but little during the security analysis. Little field data on the actual work of operators operating in the specific operating category is available.Therefore, we model the application process for specific category operations and produce design recommendations, following interviews and a questionnaire submitted to drone operators and regulators. These recommendations are positioned according to three axes to be supported: automation, augmentation, and collaboration.Finally, in a specific use case with an operator who had to perform a safety study and apply for operating authorization on a controlled aerodrome, some recommendations are implemented to follow these processes to tool them. We then end up with an interactive map and new so-called safety-oriented interactions allowing a more effective description of the concept of operations based on a geovisual analysis of drone operations, to support their safety.Les drones apportent d'importants bienfaits à l'humanité, par exemple en tant que soutiens agiles et efficaces lors de la gestion des situations d'urgence ou de catastrophes naturelles, en permettant des livraisons de matériel médical plus rapides dans les endroits enclavés, ou l'acquisition accélérée de grandes quantités de données utiles pour la science et l'économie. Les aéronefs sans pilote à bord sont plus faciles à déployer, moins chers à construire, à exploiter et à entretenir que ceux de l'aviation conventionnelle. Parmi toutes les applications des drones, celles qui produiront un impact positif important sur la société se feront principalement hors vue du pilote à distance. Cependant, ce mode d'exploitation augmente le niveau de risque associé aux opérations.Avant de pouvoir réaliser les opérations, des études de sécurité devront être réalisées par les exploitants. Puis, ils devront demander une autorisation d’exploitation à une autorité compétente, qui vérifiera et validera le niveau de sécurité envisagé. Ces études de risque sont chronophages et reposent sur une méthodologie complexe appelée Specific Operation Risk Assessment. De plus, il est prévu une augmentation importante du nombre de missions de ce type dans les années à venir, en même temps que le nombre d’exploitations de drones devrait augmenter.Comment alors rendre plus utilisable la réalisation des études de sécurité et la demande d'autorisation d'exploitation des missions de drones, tout en maximisant la sécurité ?Grâce à une revue systématique de la littérature, nous compilons les contributions existantes en matière d'IHM. Nous classifions les interactions selon tâches effectuées, la phase de vol et l'utilisation des représentations cartographiques.Puis les recommandations de conception sont synthétisées. Toutefois, ces interactions sont le plus souvent appliquées pendant la phase d’exécution, et beaucoup moins la phase de préparation qui représente la majeure partie du temps d'une mission et durant laquelle les tâches d'analyse de sécurité et de demande d'autorisation sont réalisées. L'usage des cartes pour représenter l'opération est aussi largement étudié durant la phase d’exécution mais peu durant l'analyse de sécurité. Peu de données de terrain sur le travail réel des opérateurs opérant dans la catégorie d'exploitation spécifique sont disponibles.Nous modélisons donc le processus de demande d'autorisation d'exploitation en catégorie spécifique et produisons des recommandations de design, suite à des entretiens et un questionnaire soumis aux exploitants de drones et aux régulateurs. Ces recommandations se positionnent par rapport à trois axes à soutenir : l'automatisation, l'augmentation et la collaboration.Enfin, sur un cas d'utilisation précis avec un opérateur qui devait réaliser une étude de sécurité et demander une autorisation d'exploitation sur un aérodrome contrôlé, certaines recommandations sont mises en œuvre pour suivre ces processus afin de les outiller. Nous aboutissons alors à une carte interactive et de nouvelles interactions dites orientées sécurité permettant la description davantage effective du concept d'opérations en se basant une analyse géovisuelle des opérations de drones, afin de soutenir leur sécurité
HARVIS: dynamic rerouting assistant using deep learning techniques for Single Pilot Operations (SPO)
No full textInternational audienceWhen a diversion due to an emergency is required in flight, and especially in SOP operations during the approach and landing phases, the pilot's workload increases considerably. To help gathering the relevant information and calculating the new alternative flight paths, we developed a digital assistant for dynamic rerouting, which uses deep learning algorithms to calculate the new trajectories for landing based on data collected from previous flights and METAR information. This AI assistant would be capable of improving pilots' decision-making when a rerouting is required. The rerouting assistant HMI prototype was developed and validated in feedback sessions with pilots, Advisory Board workshops with several stakeholders and a human-in-the-loop with 8 professional pilots at ENAC A320 research simulator. The concept of the assistant was appraised positively, although an effort is still to be done to improve the overall interaction and interface with the assistant to obtain some benefits in terms of workload. Aspects such as workload, usability, trust and explainability and training are analysed and discussed in the results
Study of Molecular-Level Dispersion of Pristine Graphene in Aqueous Media via Polyvinyl Alcohol Coil Physisorption
No full textInternational audienc
Why and When Do You Look Away When Trying to Remember? Gaze Aversion as a Marker of the Attentional Switch to the Internal World
No full textAutobiographical memory retrieval is initiated by an attentional switch from the outside world to a temporary internal mental space. Gaze aversion is assumed to play a role during this phase, but has received very limited attention thus far. We designed a protocol where 33 participants answered 48 autobiographical questions while their eye movements were recorded with an eye-tracker and camcorder. Results indicated that gaze aversion prevailed over other eye behaviors such as changes of vergence. It occurred early, predominantly during the access phase of memory retrieval. Gaze aversion was observed in different directions depending on the subjects and was related to cognitive effort. It was decoupled from head movement. These results support the hypothesis that gaze aversion is related to the attentional switch from the outside world to memory
Sécurité avant tout! Étude par entretiens de la planification de missions de drones pour guider la conception des systèmes soutenant les analyses de sécurité et les demandes d’autorisation
No full textInternational audienceThe use of civilian drones is a growing market offering services such as delivery, surveillance or rescue. The operationalization of these uses is complex and presents a level of risk that must be controlled through safety analysis processes and authorization requests before any flight. In order to instrument these processes with usable interactive systems, we conducted interviews with drone operators, safety study coaches and regulators. We found that despite the use of many tools and methods, files often have to be modified several times following feedback from regulators. We describe the work processes and the interaction between actors during the missions preparation. The preparation include the definition of a concept of operation, the assessment of operational risks and obtaining an authorization to operate from authorities. For each of these steps, we offer recommendations for designing new interactive systems able to support safety.L'usage des drones civils est un marché en expansion proposant des services tels que la livraison, la surveillance ou le sauvetage. L'opérationnalisation de ces usages est complexe et présente un niveau de risque à maîtriser par des processus d'analyse de sécurité et de demandes d'autorisation avant tout vol. Afin d'instrumenter ces processus avec des systèmes interactifs utilisables, nous avons mené des entretiens auprès d'opérateurs de drones, d'accompagnateurs pour les études de sécurité et de régulateurs. Malgré l'utilisation de nombreux outils et méthodes, les dossiers doivent souvent être modifiés plusieurs fois suite aux retours des régulateurs. Nous décrivons les processus de travail et les interactions entre acteurs lors de la préparation des missions dont les étapes principales sont l’établissement d’un concept d’opérations, l’évaluation des risques opérationnels et l’obtention d’une autorisation d’exploitation. Pour chacune de ces étapes, nous proposons des recommandations pour la conception de systèmes interactifs soutenant la sécurité
Ex-post Evaluation of the American Airlines–US Airways Merger: a structural approach
No full textInternational audienceIn this paper, we estimate a structural model of the domestic US airline market to analyze the eect of the recent merger between American Airlines and US Airways. Our results show that, between 2011 and 2016, a substantial fuel price drop in conjunction with changes in consumer preferences toward direct ights completely rationalizes the observed decrease in prices. However, we estimate that, during the same period, more than half of the consumer welfare increase is due, on top of these environmental changes, to the ex-post optimization of the networks of the newly merged airline and of its competitors. Acknowledgments: We would like to thank the Guest Editors and two anonymous referees for helpful comments. Special thanks to Sara Crompton Meade and Mariane Bontemps for proofreading. Funding from the French National Research Agency (ANR) under the Investments for the Future program (Investissements d'Avenir, grant ANR-17-EURE-0010) is gratefully acknowledged
Standardization and Risk Regulation for High-Hazard Industries
No full textInternational audienceHazardous industrial activities have historically been regulated from a safety and/or risk management viewpoint based on regulations enacted by governmental authorities. This chapter describes and explains the decline in the role played by governmental actors in the process of safety regulation and the rise of private standards development organizations. Such an evolution raises a wide range of concerns regarding the incentives to enhance safety, the interests that are protected by standards endorsed by regulators, and at a societal level, the drift away from democratic governance of high-hazard activities