Archives Ouvertes HAL
Toutes les publications de l'ENAC en direct.
All ENAC publications.
[hal-04568108] How Hard is Asynchronous Weight Reassignment?
Quorum 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...
[hal-04567240] A Reactive System-specific Compilation Chain from Synchronous Dataflow Models to FPGA Netlist
Modern Field Programmable Gate Arrays (FPGAs) offer a solution to several issues related to real-time on-board systems, such as guaranteed execution time. They are currently considered as target platforms for space applications. However, the complexity of producing circuits on these components poses a challenge to their widespread adoption. To address this issue, high-level synthesis tools provide another layer of abstraction above the logic circuit design process, for example compiling C code into Hardware Description Languages such as VHDL or Verilog. However, high-level synthesis results are poorly predictable and do not guarantee the efficient use of recent FPGA...
[hal-04564025] ArGaze: An Open and Flexible Software Library for Gaze Analysis and Interaction
Gaze analysis has evolved into a mature technique with diverse applications enabling the investigation of various human activities and cognitive processes such as reading, visual attention, memory as well as real time gaze interaction. However, existing proprietary software or librairies often lacks the flexibility needed to incorporate emerging gaze metrics or real time processing, limiting researchers to predefined methodologies. To address these limitations, we introduce ArGaze, an open and flexible software library designed to provide a unified and modular approach to gaze analysis or gaze interaction. ArGaze facilitates real-time and/or post-processing analysis for...
[hal-04550976] Extending Guiding Vector Field to track unbounded UAV paths
A recent advance in vector field path following is the introduction of the Parametric Guiding Vector Field method. It allows for singularity-free vector fields with strong convergence guarantees, usable even for self-intersecting paths. However, the method requires significant gain tuning for practical use. In particular, for unbounded paths, the gains will inevitably become ill-suited for efficient path following. We propose a method to overcome this issue by introducing a dynamic step adaptation strategy, which provides additional normalization properties to the field. This allows the following of unbounded curves and reduces the number of gains to tune. The proposed...
[hal-04543171] Adversarial Robustness with Partial Isometry
Despite their remarkable performance, deep learning models still lack robustness guarantees, particularly in the presence of adversarial examples. This significant vulnerability raises concerns about their trustworthiness and hinders their deployment in critical domains that require certified levels of robustness. In this paper, we introduce an information geometric framework to establish precise robustness criteria for l2 white-box attacks in a multi-class classification setting. We endow the output space with the Fisher information metric and derive criteria on the input–output Jacobian to ensure robustness. We show that model robustness can be achieved by constraining...
[hal-04543170] VTOL site location considering obstacle clearance during approach and departure
Urban 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...
[hal-04543167] Status quo and challenges in air transport management research
Air transport management research, concerned with all facets of aviation operations, policies, and strategies, is an essential element of making our aviation system more sustainable and preparing it for the challenges inherentto the present and future. Based on a data-driven categorization of almost 2,000 papers published on the subject, we discuss the status quo in air transport management research. Through our data-driven categorization we have identified 15 broad topics. For each topic, we provide a description of the state of the art and propose 2-3 challenges, respectively. Overall, our study provides a set of 35 challenges to the research community. Accordingly, we...