Archive ouverte de l'ENAC
Not a member yet
3458 research outputs found
Sort by
Les méthodes de design systémique peuvent-elles faciliter le design durable de systèmes interactifs ?
No full textInternational audienceThe power of artefacts to reflect our culture and influence us as individuals, as highlighted by Material culture (Woodward, 2007), shows the importance of design in the ecological transition, a major issue in our society. Although sustainability cannot be based on technological solutions (Bremer et al., 2022), it should be a central concern of human-computer interactive systems design (Blevis, 2007).In Human-Computer Interaction (HCI) and Systems Engineering (SE), current efforts for a more sustainable world focus on the energy efficiency of a system, optimising its life cycle, and encouraging users to save energy. Some voices in the HCI community recognise that the current approach, which focuses on the material impact of artefacts, is reductive and insufficient in the face of this systemic problem (Knowles et al., 2018). It misses the opportunity to facilitate a necessary change in societal practices. In fact, Sustainable HCI projects attempt to respond to problems that have not been clearly formulated (Rivière, 2021), and the community struggles to develop tools and methods for this purpose.Systemic design, an emerging practice resulting from the combination of design and systems thinking, has developed methods for addressing complex problems. This paper proposes to draw inspiration from these methods to apprehend the systemic dimension of the ecological transition in the design of interactive systems, particularly in the formulation of the problem and the objectives.However, these methods and tools are designed by and for ‘systemic designers’. These, unlike interactive system designers, operate primarily at the scale of organisations and social systems (through policy, strategic decisions, etc.), within the framework of design 3.0 and 4.0 as described by Jones & van Patter (2009). This paper argues that the unit of analysis can be decorrelated from the unit of intervention, i.e. one can study and target a problem at the scale of a sociotechnical system (such as the agriculture sector) and only intervene at the scale of an interactive system (e.g. agricultural robot). It is a question of understanding the contexts in which the designed system will be placed, and its possible impacts at scale, so as to avoid simplistic solutions that could be counterproductive (e.g. rebound effect). This difference in the scale of the unit of intervention implies that the tools of systemic designers must be adapted to the needs of interactive system designers. The authors suggest the use of 'quali-quantitative' modelling.Le pouvoir qu’ont les artefacts de refléter notre culture et de nous influencer en tant qu'individus, comme souligné par la Material culture (Woodward, 2007), montre l'importance du design dans la transition écologique, un enjeu majeur de notre société. Bien que la durabilité ne puisse être basée que sur des solutions technologiques (Bremer et al., 2022), elle devrait être une préoccupation centrale de la conception des systèmes interactifs humain-machine (Blevis, 2007).Dans le domaine de l'interaction homme-machine (IHM) et de l'ingénierie système (IS), les efforts actuels pour un monde plus durable se concentrent sur l'efficacité énergétique d'un système, l'optimisation de son cycle de vie et l'encouragement des utilisateurs à économiser l'énergie. Certaines voix dans la communauté IHM reconnaissent que l'approche actuelle, qui se concentre sur l'impact matériel des artefacts, est réductrice et insuffisante face à ce problème systémique (Knowles et al., 2018). Elle ne saisit pas l'opportunité de faciliter un changement nécessaire des pratiques sociétales. En effet, les projets d'IHM durable (Sustainable HCI) tentent de répondre à des problèmes qui n'ont pas été clairement formulés (Rivière, 2021), et la communauté peine à développer des outils et des méthodes à cet effet.Le design systémique, une pratique émergente issue de la combinaison du design et de la pensée systémique, a développé des méthodes pour répondre à des problèmes complexes. Cet article propose de s'inspirer de ces méthodes pour appréhender la dimension systémique de la transition écologique dans la conception de systèmes interactifs, notamment dans la formulation du problème et des objectifs.Cependant, ces méthodes et outils sont conçus par et pour des « designers systémiques". Ces derniers, contrairement aux concepteurs de systèmes interactifs, opèrent principalement à l'échelle des organisations et des systèmes sociaux (par le biais de politiques, de décisions stratégiques, etc.), dans le cadre du design 3.0 et 4.0, tel que décrit par Jones & van Patter (2009). Cet article soutient que l'unité d'analyse peut être décorrélée de l'unité d'intervention, c'est-à-dire que l'on peut étudier et cibler un problème à l'échelle d'un système sociotechnique (ex : le secteur agricole) et n'intervenir qu'à l'échelle d'un système interactif (ex : un robot agricole). Il s'agit de comprendre les contextes dans lesquels le système conçu sera placé, et ses impacts possibles à l'échelle, afin d'éviter des solutions simplistes qui pourraient être contre-productives (ex : l'effet rebond). Cette différence d'échelle d'unité d'intervention implique d'adapter les outils des designers systémiques aux besoins des designers de systèmes interactifs. Les auteurs suggèrent l'utilisation de la modélisation "quali-quantitative"
Toward a User Interface Description Language based on bigraphs (model files, supplemental material)
No full textTowards improving personalisation of MaaS tools
No full textInternational audienceOver the past few years, Mobility-as-a-Service (MaaS) has become an alternative to owning a private car, integrating various public and shared travel modes in a single platform. Despite its attractiveness in meeting everyday travel needs, it has not seen high penetration rates within the urban population. A solution to increase its acceptability is to improve its personalisation so that it can better cater to the needs of each user. In this paper, we propose the global architecture of a MaaS tool under development for the city of Toulouse and its surroundings. The proposed architecture combines the information about users' mobility patterns and their individual preferences along with real-time traffic updates to proactively recommend personalised routes. Within the application, users' probability of choosing a particular transport mode, calculated using discrete choice models, as well as various gamificationbased elements are integrated in order to understand users' travel behaviour and promote sustainable transportation
Hyperheuristic Approach Based on Reinforcement Learning for Air Traffic Complexity Mitigation
No full textInternational audienceAirspace capacity has become a critical resource for air transportation. Complexity in traffic patterns is a structural problem, whereby airspace capacity is sometimes saturated before the number of aircraft has reached the capacity threshold. This paper addresses a strategic planning problem with an efficient optimization approach that minimizes traffic complexity based on linear dynamical systems in order to improve the traffic structure. Traffic structuring techniques comprise departure time adjustment, en route trajectory deviation, and flight-level allocation. The resolution approach relies on the hyperheuristic framework based on reinforcement learning to improve the searching strategy during the optimization process. The proposed methodology is implemented and tested with a full day of traffic in the French airspace. Numerical results show that the proposed approach can reduce air traffic complexity by 92.8%. The performance of the proposed algorithm is then compared with two different algorithms, including the random search and the standard simulated annealing. The proposed algorithm provides better results in terms of air traffic complexity and the number of modified trajectories. Further analysis of the proposed model was conducted by considering time uncertainties. This approach can be an innovative solution for capacity management in the future air traffic management system
Successive Convexification for Optimal Control with Signal Temporal Logic Specifications
No full textInternational audienceAs the scope and complexity of modern cyber-physical systems increase, newer and more challenging mission requirements will be imposed on the optimal control of the underlying unmanned systems. This paper proposes a solution to handle complex temporal requirements formalized in Signal Temporal Logic (STL) specifications within the Successive Convexification (SCvx) algorithmic framework. This SCvx-STL solution method consists of four steps: 1) Express the STL specifications using their robust semantics as state constraints. 2) Introduce new auxiliary state variables to transform these state constraints as system dynamics, by exploiting the recursively defined structure of robust STL semantics. 3) Smooth the resulting system dynamics with polynomial smooth min-and maxfunctions. 4) Convexify and solve the resulting optimal control problem with the SCvx algorithm, which enjoys guaranteed convergence and polynomial time subproblem solving capability. Our approach retains the expressiveness of encoding mission requirements with STL semantics, while avoiding the usage of combinatorial optimization techniques such as Mixed-integer programming. Numerical results are shown to demonstrate its effectiveness
The use of 5G networks to control UAVs
No full textInternational audienceNos últimos anos, drones foram introduzidos em muitas áreas diferentes, desde entretenimento até aplicações militares, e agora com a pandemia COVID-19, a entrega de medicamentos também está sendo explorada. Atualmente, o queos impede de serem usados ainda mais são sua capacidade de energia limitada, suas baixas taxas de transmissão de dados e a necessidade de componentes caros para processamento a bordo e streaming de vídeo. Para tentar mitigar esses problemas, pesquisas relacionadas ao uso de redes 5G para se conectar com UAVs foram realizadas recentemente. Isso deve permitir através da otimização e compartilhamento de recursos reduzir os custos de instrumentação a bordo e, em seguida, favorecer novas aplicações de UAVs. Portanto, este trabalho tem como objetivo mostrar as linhas de pesquisa sobre o controle uav utilizando redes 5G
A Fast Wavelet-to-Wavelet Propagation Method for the Simulation of Long-Range Propagation in Low Troposphere
No full textInternational audienceAs an alternative method to the discrete split-step Fourier method, the split-step wavelet method has recently been derived. This method based on a wavelet decomposition of the field is efficient and accurate in simulating the long-range propagation of electromagnetic waves in the low troposphere. In this paper, to further improve the computational efficiency and take full advantage of wavelet characteristics, a waveletto-wavelet propagation method is proposed. The propagation, variable refractivity, and apodization are accounted in the wavelet domain. The computational complexity is reduced, since no transforms are performed between wave fields and wavelet coefficients. This method works well for the propagation over a planar ground with a constant impedance. When a variable impedance ground condition and/or an irregular relief are considered, a hybridization with the split-step wavelet method is proposed. These methods are tested and validated by means of numerical experiments, showing very good efficiency and accuracy
Large deviation results for triangular arrays of semiexponential random variables
No full textInternational audienceAsymptotics deviation probabilities of the sum S n = X 1 + · · · + X n of independent and identically distributed real-valued random variables have been extensively investigated , in particular when X 1 is not exponentially integrable. For instance, A.V. Nagaev formulated exact asymptotics results for P(S n > x n) when X 1 has a semiexponential distribution (see, [16, 17]). In the same setting, the authors of [4] derived deviation results at logarithmic scale with shorter proofs relying on classical tools of large deviation theory and expliciting the rate function at the transition. In this paper, we exhibit the same asymptotic behaviour for triangular arrays of semiexponentially distributed random variables, no more supposed absolutely continuous