Energy-Efficient RIS-Enabled NOMA Communication for 6G LEO Satellite Networks

E-print/Working paper (2023)

Reconfigurable Intelligent surfaces (RIS) have the potential to significantly improve the performance of future 6G LEO satellite networks. In particular, RIS can improve the signal quality of ground ... [more ▼]

Reconfigurable Intelligent surfaces (RIS) have the potential to significantly improve the performance of future 6G LEO satellite networks. In particular, RIS can improve the signal quality of ground terminal, reduce power consumption of satellite and increase spectral efficiency of overall network. This paper proposes an energy-efficient RIS-enabled NOMA communication for LEO satellite networks. The proposed framework simultaneously optimizes the transmit power of ground terminals at LEO satellite and passive beamforming at RIS while ensuring the quality of services. Due to the nature of the considered system and optimization variables, the problem of energy efficiency maximization is formulated as non-convex. In practice, it is very challenging to obtain the optimal solution for such problems. Therefore, we adopt alternating optimization methods to handle the joint optimization in two steps. In step 1, for any given phase shift vector, we calculate efficient power for ground terminals at satellite using Lagrangian dual method. Then, in step 2, given the transmit power, we design passive beamforming for RIS by solving the semi-definite programming. To validate the proposed solution, numerical results are also provided to demonstrate the benefits of the proposed optimization framework. [less ▲]

Moral Hazard, central bankers, and Banking Union: professional dissensus and the politics of European financial system stability

in Journal of European Integration (2023), 45(1), 15-41

Banking Union was a major policy response to the financial crisis that began in 2007 and the subsequent Eurozone crisis. Moral hazard has frequently been presented as a major cause of these crises ... [more ▼]

Banking Union was a major policy response to the financial crisis that began in 2007 and the subsequent Eurozone crisis. Moral hazard has frequently been presented as a major cause of these crises. Therefore, Banking Union can be understood as a response to moral hazard in relation to banks and sovereigns. Yet, moral hazard was an acknowledged and supposedly managed problem prior to these events. Paradoxically, moral hazard has been used to justify contradictory policy options to safeguard European financial system stability, such as decentralized institutional arrangements for banking supervision but also a centralized system coordinated by the European Central Bank (ECB). To address this paradox, this paper investigates moral hazard as a political concept. Based on a comparison of how central bankers from the Bundesbank and the ECB understand and use the moral hazard concept, this paper argues that moral hazard is closer to the realm of politics than expertise. [less ▲]

On-Demand Security Framework for 5GB Vehicular Networks

in IEEE Internet of Things Magazine (2023)

Building accurate Machine Learning (ML) attack detection models for 5G and Beyond (5GB) vehicular networks requires collaboration between Vehicle-to-Everything (V2X) nodes. However, while operating ... [more ▼]

Building accurate Machine Learning (ML) attack detection models for 5G and Beyond (5GB) vehicular networks requires collaboration between Vehicle-to-Everything (V2X) nodes. However, while operating collaboratively, ensuring the ML model's security and data privacy is challenging. To this end, this article proposes a secure and privacy-preservation on-demand framework for building attack-detection ML models for 5GB vehicular networks. The proposed framework emerged from combining 5GB technologies, namely, Federated Learning (FL), blockchain, and smart contracts to ensure fair and trusted interactions between FL servers (edge nodes) with FL workers (vehicles). Moreover, it also provides an efficient consensus algorithm with an intelligent incentive mechanism to select the best FL workers that deliver highly accurate local ML models. Our experiments demonstrate that the framework achieves higher accuracy on a well-known vehicular dataset with a lower blockchain consensus time than related solutions. Specifically, our framework enhances the accuracy by 14% and decreases the consensus time, at least by 50%, compared to related works. Finally, this article discusses the framework's key challenges and potential solutions. [less ▲]

Internships in Times of Crisis: Collaborative Production of Instructional Videos at a Distance

in Willemse, Martijn (Ed.) EAPRIL 2022 CONFERENCE PROCEEDINGS (2023, March)

The Bachelor in Educational Sciences (BScE) at the University of Luxembourg offers a thorough and demanding teacher training program that combines academic and practical knowledge. As in many other ... [more ▼]

The Bachelor in Educational Sciences (BScE) at the University of Luxembourg offers a thorough and demanding teacher training program that combines academic and practical knowledge. As in many other initial teacher training programs, internships are a key part of each semester in the BScE. In the face of the COVID-19 health crisis, this essential part of our teacher training program could not be maintained. Indeed, the schools were closed, and the pupils were taught at a distance by their teachers. We therefore had to quickly innovate and set up alternative learning activities that best met the objectives of the internships. We thus asked our students to design and produce educational videos, in dyads, for the country's schools. The aim was to enable our students to develop the necessary skills to produce such learning resources and to make them available to schools via the Internet. We will describe, analyse, and evaluate the solution we had to urgently put in place and the videos that were produced as a result. We will also discuss possible lessons learned that might lead to adaptations in our training program. [less ▲]

MAgNET: A Graph U-Net Architecture for Mesh-Based Simulations

E-print/Working paper (2023)

In many cutting-edge applications, high-fidelity computational models prove too slow to be practical and are thus replaced by much faster surrogate models. Recently, deep learning techniques have become ... [more ▼]

In many cutting-edge applications, high-fidelity computational models prove too slow to be practical and are thus replaced by much faster surrogate models. Recently, deep learning techniques have become increasingly important in accelerating such predictions. However, they tend to falter when faced with larger and more complex problems. Therefore, this work introduces MAgNET: Multi-channel Aggregation Network, a novel geometric deep learning framework designed to operate on large-dimensional data of arbitrary structure (graph data). MAgNET is built upon the MAg (Multichannel Aggregation) operation, which generalizes the concept of multi-channel local operations in convolutional neural networks to arbitrary non-grid inputs. The MAg layers are interleaved with the proposed novel graph pooling/unpooling operations to form a graph U-Net architecture that is robust and can handle arbitrary complex meshes, efficiently performing supervised learning on large- dimensional graph-structured data. We demonstrate the predictive capabilities of MAgNET for several non-linear finite element simulations and provide open-source datasets and codes to facilitate future research. [less ▲]

Pratiques et enjeux de la sédation palliative en Belgique

in La Revue de l'Infirmière (2023), 72(289), 32-35

En Belgique, la sédation continue en soins palliatifs est considérée comme un traitement symptomatique. Il n’existe pas de législation spécifique pour l’encadrer. Son utilisation adéquate repose sur un ... [more ▼]

En Belgique, la sédation continue en soins palliatifs est considérée comme un traitement symptomatique. Il n’existe pas de législation spécifique pour l’encadrer. Son utilisation adéquate repose sur un ensemble de recommandations qui permettent de s’assurer à la fois d’un traitement efficace et du respect des préférences du patient, dans un cadre éthique rigoureux. [less ▲]

Editorial 'Lecture discourse and lecture training'

in Journal of English for Academic Purposes (2023), 62(101223),

Fluctuations of Polyspectra in Spherical and Euclidean Random Wave Models

E-print/Working paper (2023)

Opinion Statement ECJ-TF 4/2022 on the ECJ Decision of 22 September 2022 in W AG (Case C-538/20) on the Deductibility of Foreign Final Losses

in European Taxation (2023), 63(2/3), 105-110

In this CFE Opinion Statement, submitted to the EU Institutions in November 2022, the CFE ECJ Task Force comments on the ECJ decision of 22 September 2022 in W AG (Case C-538/20), on the deductibility of ... [more ▼]

In this CFE Opinion Statement, submitted to the EU Institutions in November 2022, the CFE ECJ Task Force comments on the ECJ decision of 22 September 2022 in W AG (Case C-538/20), on the deductibility of foreign final losses. The W AG decision makes it clear that comparability should be examined differently depending on whether the exemption is granted by domestic or tax treaty law. The CFE ECJ Task Force has reservations regarding this distinction. For the taxpayer, an exemption has the same economic effects regardless of whether it is adopted through domestic law or tax treaty law. Moreover, W AG departs from the Court’s reasoning and thinking in Lidl Belgium, which also concerned Germany and the same rules. Ideally, the Court should have made this explicit. Finally, it remains to be seen whether Marks and Spencer (Case C-446/03) is still “good law” or if W AG was one of the final nails in the coffin of the “final loss” doctrine. [less ▲]

Varier les supports et les ressources pour enseigner le lexique en classe de français

Presentation (2023, February 28)

La perspective actionnelle, au centre des cours de langues depuis les années 2000, prend en compte le besoin de communiquer des apprenants. Ces derniers sont habitués à réaliser des tâches en contexte ... [more ▼]

La perspective actionnelle, au centre des cours de langues depuis les années 2000, prend en compte le besoin de communiquer des apprenants. Ces derniers sont habitués à réaliser des tâches en contexte pour communiquer dans la langue cible, alors comment rendre aujourd’hui l’apprentissage du lexique dynamique pour nourrir ces interactions dans le contexte multilingue de l’enseignement secondaire au Luxembourg ? Dans cette communication, nous allons explorer plusieurs ressources (l’art et des applications numériques spécialisées sur le lexique) et les travailler sur différents supports (le téléphone et les tablettes). Ces outils didactisés offrent des stratégies d’enseignement-apprentissage en classe inversée ou en enseignement hybride, tout en permettant -nous le verrons-, de maintenir l’attention des élèves en cours de français. Cette démarche facilite également la mise en place de la pédagogie différenciée auprès d’un public aux niveaux hérétogènes (Français Langue Etrangère, Français Langue Seconde, et Français Langue Maternelle). [less ▲]