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A review of acoustic metamaterials for naval and underwater defense applications: from historical concepts to new trends
No full textInternational audienceSince World War II, there have been many efforts worldwide to design hull coatings for naval and underwater defense applications in order to reduce either noise radiated from the hull (discretion) or acoustic reflection from the hull (stealth). This paper presents a non-exhaustive review of concepts that have emerged since the iconic Alberich coating and highlights new trends and promising candidates, such as metamaterials, to improve the discretion and stealth performance of underwater defense systems. The need for acoustic materials for naval and underwater applications is first explained, along with some specific design requirements for acoustic coatings. Two coatings technologies, called micro-inclusion coatings and macro-inclusion coatings, are then successively reviewed. New trends in materials design for naval and underwater defense applications are also presented in the following section. This paper concludes by introducing the need for acoustic materials in the frame of new threats to the naval industries as well as other non-naval areas, opening new possibilities for their design
Comprehensive Analysis of Hybrid Approaches to Li-Fi and LPWAN Systems for IoT with Satellite-Assisted Communication
No full textInternational audienceHealthcare access remains a persistent concern for populations globally, particularly in remote areas. While telemedicine has emerged as a solution for addressing medical deserts in non-urban regions, the current priority is developing more sophisticated tools for disease identification and establishing efficient systems for transmitting medical data to hospitals and healthcare centers. Healthcare requires fast, accurate, and real-time medical data transmission. LPWAN with LoRa modules offers long-distance transmission solutions, requiring antennas above buildings and trees to overcome the Fresnel Zone issues. LoRa data rates vary from 366 bps (SF12, 125 kHz) to 6,836 bps (SF7, 125 kHz), while LiFi serves as an alternative with speeds up to 5 Gbps for point-to-point transmission of patient X-rays or medical videos. This research develops a Cross Technology Communication (CTC) system that integrates Li-Fi and LoRaWAN protocols for Internet of Medical Things (IoMT) applications. The main challenge in medical data transmission is the varying bandwidth requirements, with low bandwidth data, such as in the case of heart rate and SpO2, and data with high bandwidth requirements, such as radiography and tumor videos. The proposed hybrid system utilizes the wide bandwidth of Li-Fi (up to 1 Gbps) and the wide coverage of LoRaWAN with specific CTC methods: Direct Translation, Packet-Level CTC, Physical Layer CTC, and Gateway-based CTC. Our research presents a comprehensive theoretical analysis of LPWAN satellite communication. This approach effectively addresses the persistent challenges in Non-Terrestrial Communication (NTC). The contribution of this research is the optimization of medical data transmission
XAI for wireless communications
No full textInternational audienceThe native artificial intelligence (AI) concept is envisioned to be integrated into 6G future communications. Due to the black box nature of the majority of AI models, the decision-making strategy used by these models is critical, risky, and challenging. This issue can be tackled by developing explainable AI (XAI) schemes that aim to explain the logic behind the black box model behavior, and thus, ensure its efficient and safe deployment. In this context, this chapter highlights the main challenges of the recent AI-based solutions for wireless communications, in particular, physical (PHY) layer applications. In addition to that, the latest research efforts toward designing XAI schemes for PHY layer applications are discussed. As a case study, this chapter presents an XAI-based scheme for channel estimation in wireless communications, where the presented scheme shows that employing XAI can offer numerous advantages, including (1) understanding the black box model behavior, (2) reducing the overall computational complexity of the employed AI model, and (3) improving the performance of the desired application. Finally, a list of future research directions is provided
Using Synapse Saturation in Spiking Neural Networks for Wake Up Receivers in Internet of Things Networks
No full textInternational audienceEnergy consumption remains a predominant constraint in numerous Internet of Things (IoT) applications, as microcontrollers typically exhibit excessively high power consumption. To address this issue, novel circuit designs have been introduced, and the utilization of spiking neurons and analog computing has emerged as a promising approach, enabling substantial reductions in power consumption. However, operating within the analog domain poses challenges in managing the sequential processing of incoming signals, which is essential for processing wireless communication signals. In this study, we leverage a bio-inspired phenomenon known as Saturating Synapses to create a temporal filter. We present a model of neurons whose synapses respond specifically within a defined range of delays between two incoming spikes, but remain unresponsive when the Inter-Spike Timing (IST) falls outside this range. Our investigation delves into the model’s parameters to better understand their selection criteria and adaptation for the IST. Subsequently, we show the system’s efficiency in recognizing specific sequences defined by these ISTs. This paper’s novelty lies in the proposal of a new analog processing approach for managing temporal sequences, which permits a much lower energy consumption compared to classical approaches
Renforcement de l’engagement dans l’Industrie 5.0
No full textInternational audienceThis article explores the impact of new technologies on employee engagement in the context of Industry 5.0.Although Industry 4.0 (I4.0) was introduced in 2011, most companies are still in the early stages of the transition. Industry5.0 (I5.0) aims to further integrate social and environmental priorities, promoting harmonious collaboration betweenhumans and machines. Autonomy, a crucial pillar of I5.0, is closely linked to employee engagement. A systematic review ofthe literature on I4.0 and I5.0 identified 12 relevant articles. These studies highlight the importance of engagement in theadoption of new technologies, although methodologies and definitions of engagement vary considerably. The most studiedtechnologies are artificial intelligence, simulation, and cobotics. The majority of studies suggest that these technologiesenhance engagement, but some also highlight risks of degradation. A global engagement model, such as Octalysis, isproposed to better understand the levers of engagement. The results emphasize the need for standardized methodologiesand a common definition of engagement for more robust future research.Cet article explore l'impact des nouvelles technologies sur l'engagement des employés dans le cadre de l'Industrie 5.0. Bien que l'Industrie 4.0 (I4.0) ait été introduite en 2011, la plupart des entreprises en sont encore aux premiers stades de la transition. L'Industrie 5.0 (I5.0) vise à intégrer davantage les priorités sociales et environnementales, en favorisant une collaboration harmonieuse entre humains et machines. L'autonomie, un pilier crucial de l'I5.0, est étroitement liée à l'engagement des employés. La revue systématique des travaux sur l'I4.0 et l'I5.0 a permis d'identifier 12 articles pertinents. Ces études mettent en évidence l'importance de l'engagement dans l'adoption des nouvelles technologies, bien que les méthodologies et les définitions de l'engagement varient considérablement. Les technologies d'intelligence artificielle, de simulation et de cobotique sont les plus étudiées. La majorité des études suggèrent que ces technologies renforcent l'engagement, mais certaines soulignent également des risques de dégradation. Un modèle d'engagement global, comme Octalysis, est proposé pour mieux comprendre les leviers de l'engagement. Les résultats soulignent la nécessité de méthodologies standardisées et d'une définition commune de l'engagement pour des recherches futures plus robustes
Interference Aware Ultra Reliable Communications in In-X IoT Sub-Networks
No full textInternational audienceIn an environment with strict constraints on maximum permissible delay and a high density of interconnected devices, achieving global system coordination becomes impractical. This lack of coordination results in increased noise due to interference. Under such conditions, interference levels can vary significantly from one packet to another, with only their statistical properties being estimable before transmission. Notably, the variance of the resulting noise remains unpredictable. To address this challenge, we propose an approach to optimize the modulation and coding schemes. Our method models interference using a mixture of exponential distributions. To accurately estimate its parameters, we employ a bootstrap method. We also propose a Quickest Change Detection approach to identify changes in the interference distribution. This approach allows us to determine transmission parameters that ensure a predefined success probability for transmitted packets, without requiring additional listening and estimation tasks on the end devices
Leveraging 3GPP Features and Optimization Techniques for 5G NR-V2X Resource Allocation: A Survey
No full textInternational audienceCellular Vehicle-to-everything (C-V2X) communication is critical for Intelligent Transportation Systems (ITS), facilitating information exchange among road users and infrastructure. Since its first introduction in rel-15 by 3GPP, 5G NR-V2X features have continued to evolve, aiming to support increasingly advanced V2X services. Addressing diverse service requirements, spectrum scarcity, dynamic vehicular environments, and radio interference necessitates efficient resource allocation strategies for the 5G NR-V2X system. However, dealing with resource allocation problems involving various conflicting objectives and constraints while accomplishing the Quality of Services (QoS) requirements of the V2X system remains a challenging issue. In this direction, this survey examines state-of-the-art resource allocation strategies for 5G NR-V2X, focusing on 3GPP features associated with V2X communication and their implications, along with optimization techniques employed in designing resource allocation strategies. Specifically, we present the benefits and challenges of each 3GPP feature and optimization technique, and their application to communication and computing resource allocation problems. Finally, we discuss issues tied to 3GPP features and optimization techniques, then highlight future research opportunities for efficient 5G NR-V2X resource allocation
Les paradoxes écologiques des mobilités post-Covid
No full textInternational audienceLa pandémie de Covid-19 a-t-elle favorisé l’évolution vers des mobilités plus durables ? Pour conclure le dossier consacré à cette question, ses coordinateurs montrent les contradictions des tendances à l’œuvre, entre retour aux mobilités d’avant et inflexions vers un monde plus écologique
Salvo D'Agostino's Publications from 1964 to 2019–[posthumous 2022]: 237 Works
No full textInternational audienceBy means of his finest intellectual vision of history of physics and science, Salvo D’Agostino continuously published for more than fifty-five years, crossing two centuries. Other several works are unpublished or remain in pre-print (see below); and others could be unknown, as well. Below the huge list of Salvo Dagostino’s References has been collected by Raffaele Pisano in collaboration with Pasquale Tucci, Arcangelo Rossi and Caterina D’Agostino. The reader will also find previously unseen images of Salvo D’Agostino (Figs. 1, 2, 3 and 4). They are a kind courtesy—and—authorised by Caterina D’Agostino, Salvo’s daughter