Black hole mirages: electron lensing and Berry curvature effects in inhomogeneously tilted Weyl semimetals

in arXiv (2022)

We study electronic transport in Weyl semimetals with spatially varying nodal tilt profiles. We find that the flow of electrons can be guided precisely by judiciously chosen tilt profiles. In a wide ... [more ▼]

We study electronic transport in Weyl semimetals with spatially varying nodal tilt profiles. We find that the flow of electrons can be guided precisely by judiciously chosen tilt profiles. In a wide regime of parameters, we show that electron flow is described well by semiclassical equations of motion similar to the ones governing gravitational attraction. This analogy provides a physically transparent tool for designing tiltronic devices, such as electronic lenses. The analogy to gravity circumvents the notoriously difficult full-fledged description of inhomogeneous solids, but a comparison to microscopic lattice simulations shows that it is only valid for trajectories sufficiently far from analogue black holes. We finally comment on the Berry curvature-driven transverse motion, and relate the latter to spin precession physics. [less ▲]

Unclonable human-invisible machine vision markers leveraging the omnidirectional chiral Bragg diffraction of cholesteric spherical reflectors

in Light: Science and Applications (2022), 11(309), 10103841377-022-01002-4

The seemingly simple step of molding a cholesteric liquid crystal into spherical shape, yielding a Cholesteric Spherical Reflector (CSR), has profound optical consequences that open a range of ... [more ▼]

The seemingly simple step of molding a cholesteric liquid crystal into spherical shape, yielding a Cholesteric Spherical Reflector (CSR), has profound optical consequences that open a range of opportunities for potentially transformative technologies. The chiral Bragg diffraction resulting from the helical self-assembly of cholesterics becomes omnidirectional in CSRs. This turns them into selective retroreflectors that are exceptionally easy to distinguish— regardless of background—by simple and low-cost machine vision, while at the same time they can be made largely imperceptible to human vision. This allows them to be distributed in human-populated environments, laid out in the form of QR-code-like markers that help robots and Augmented Reality (AR) devices to operate reliably, and to identify items in their surroundings. At the scale of individual CSRs, unpredictable features within each marker turn them into Physical Unclonable Functions (PUFs), of great value for secure authentication. Via the machines reading them, CSR markers can thus act as trustworthy yet unobtrusive links between the physical world (buildings, vehicles, packaging,...) and its digital twin computer representation. This opens opportunities to address pressing challenges in logistics and supply chain management, recycling and the circular economy, sustainable construction of the built environment, and many other fields of individual, societal and commercial importance. [less ▲]

CalcGraph: taming the high costs of deep learning using models

in Software and Systems Modeling (2022)

Models based on differential programming, like deep neural networks, are well established in research and able to outperform manually coded counterparts in many applications. Today, there is a rising ... [more ▼]

Models based on differential programming, like deep neural networks, are well established in research and able to outperform manually coded counterparts in many applications. Today, there is a rising interest to introduce this flexible modeling to solve real-world problems. A major challenge when moving from research to application is the strict constraints on computational resources (memory and time). It is difficult to determine and contain the resource requirements of differential models, especially during the early training and hyperparameter exploration stages. In this article, we address this challenge by introducing CalcGraph, a model abstraction of differentiable programming layers. CalcGraph allows to model the computational resources that should be used and then CalcGraph’s model interpreter can automatically schedule the execution respecting the specifications made. We propose a novel way to efficiently switch models from storage to preallocated memory zones and vice versa to maximize the number of model executions given the available resources. We demonstrate the efficiency of our approach by showing that it consumes less resources than state-of-the-art frameworks like TensorFlow and PyTorch for single-model and multi-model execution. [less ▲]

MARL based resource allocation scheme leveraging vehicular cloudlet in automotive-industry 5.0

in Journal of King Saud University - Computer and Information Sciences (2022)

Automotive-Industry 5.0 will use Beyond Fifth-Generation (B5G) communications to provide robust, abundant computation resources and energy-efficient data sharing among various Intelligent Transportation ... [more ▼]

Automotive-Industry 5.0 will use Beyond Fifth-Generation (B5G) communications to provide robust, abundant computation resources and energy-efficient data sharing among various Intelligent Transportation System (ITS) entities. Based on the vehicle communication network, the Internet of Vehicles (IoV) is created, where vehicles’ resources, including processing, storage, sensing, and communication units, can be leveraged to construct Vehicular Cloudlet (VC) to realize resource sharing. As Connected and Autonomous Vehicles (CAV) onboard computing is becoming more potent, VC resources (comprising stationary and moving vehicles’ idle resources) seems a promising solution to tackle the incessant computing requirements of vehicles. Furthermore, such spare computing resources can significantly reduce task requests’ delay and transmission costs. In order to maximize the utility of task requests in the system under the maximum time constraint, this paper proposes a Secondary Resource Allocation (SRA) mechanism based on a dual time scale. The request service process is regarded as M/M/1 queuing model and considers each task request in the same time slot as an agent. A Partially Observable Markov Decision Process (POMDP) is constructed and combined with the Multi-Agent Reinforcement Learning (MARL) algorithm known as QMix, which exploits the overall vehicle state and queue state to reach effective computing resource allocation decisions. There are two main performance metrics: the system’s total utility and task completion rate. Simulation results reveal that the task completion rate is increased by 13%. Furthermore, compared with the deep deterministic policy optimization method, our proposed algorithm can improve the overall utility value by 70% and the task completion rate by 6%. [less ▲]

Delineation of functionally essential protein regions for 242 neurodevelopmental genes

in Brain (2022), awac381

Neurodevelopmental disorders (NDDs), including severe pediatric epilepsy, autism, and intellectual disabilities are heterogeneous conditions in which clinical genetic testing can often identify a ... [more ▼]

Neurodevelopmental disorders (NDDs), including severe pediatric epilepsy, autism, and intellectual disabilities are heterogeneous conditions in which clinical genetic testing can often identify a pathogenic variant. For many of them, genetic therapies will be tested in this or the coming years in clinical trials. In contrast to first-generation symptomatic treatments, the new disease-modifying precision medicines require a genetic test-informed diagnosis before a patient can be enrolled in a clinical trial. However, even in 2022, most identified genetic variants in NDD genes are ‘Variants of Uncertain Significance’. To safely enroll patients in precision medicine clinical trials, it is important to increase our knowledge about which regions in NDD-associated proteins can ‘tolerate’ missense variants and which ones are ‘essential’ and will cause a NDD when mutated. In addition, knowledge about functionally indispensable regions in the three-dimensional (3D) structure context of proteins can also provide insights into the molecular mechanisms of disease variants. We developed a novel consensus approach that overlays evolutionary, and population based genomic scores to identify 3D essential sites (Essential3D) on protein structures. After extensive benchmarking of AlphaFold predicted and experimentally solved protein structures, we generated the currently largest expert curated protein structure set for 242 NDDs and identified 14,377 Essential3D sites across 189 gene disorders associated proteins. We demonstrate that the consensus annotation of Essential3D sites improves prioritization of disease mutations over single annotations. The identified Essential3D sites were enriched for functional features such as intermembrane regions or active sites and discovered key inter-molecule interactions in protein complexes that were otherwise not annotated. Using the currently largest autism, developmental disorders, and epilepsies exome sequencing studies including >360,000 NDD patients and population controls, we found that missense variants at Essential3D sites are 8-fold enriched in patients. In summary, we developed a comprehensive protein structure set for 242 neurodevelopmental disorders and identified 14,377 Essential3D sites in these. All data are available at https://es-ndd.broadinstitute.org for interactive visual inspection to enhance variant interpretation and development of mechanistic hypotheses for 242 NDDs genes. The provided resources will enhance clinical variant interpretation and in silico drug target development for NDD-associated genes and encoded proteins. [less ▲]

DBSegment: Fast and robust segmentation of deep brain structures considering domain generalisation

in Human Brain Mapping (2022)

Segmenting deep brain structures from magnetic resonance images is important for patient diagnosis, surgical planning, and research. Most current state-of-the-art solutions follow a segmentation-by ... [more ▼]

Segmenting deep brain structures from magnetic resonance images is important for patient diagnosis, surgical planning, and research. Most current state-of-the-art solutions follow a segmentation-by-registration approach, where subject magnetic resonance imaging (MRIs) are mapped to a template with well-defined segmentations. However, registration-based pipelines are time-consuming, thus, limiting their clinical use. This paper uses deep learning to provide a one-step, robust, and efficient deep brain segmentation solution directly in the native space. The method consists of a preprocessing step to conform all MRI images to the same orientation, followed by a convolutional neural network using the nnU-Net framework. We use a total of 14 datasets from both research and clinical collections. Of these, seven were used for training and validation and seven were retained for testing. We trained the network to segment 30 deep brain structures, as well as a brain mask, using labels generated from a registration-based approach. We evaluated the generalizability of the network by performing a leave-one-dataset-out cross-validation, and independent testing on unseen datasets. Furthermore, we assessed cross-domain transportability by evaluating the results separately on different domains. We achieved an average dice score similarity of 0.89 ± 0.04 on the test datasets when compared to the registration-based gold standard. On our test system, the computation time decreased from 43 min for a reference registration-based pipeline to 1.3 min. Our proposed method is fast, robust, and generalizes with high reliability. It can be extended to the segmentation of other brain structures. It is publicly available on GitHub, and as a pip package for convenient usage. [less ▲]

The Occupational Structure of England and Wales: the 1939 National Register

in Research Data Journal for the Humanities and Social Sciences (2022)

A gap in the census surveys for England and Wales between 1921 and 1951 hinders the analysis of their labour structure for the interwar years. The present article uses a dataset containing occupational ... [more ▼]

A gap in the census surveys for England and Wales between 1921 and 1951 hinders the analysis of their labour structure for the interwar years. The present article uses a dataset containing occupational titles from the National Register – a census-like enumeration of 1939, recently digitised by the genealogy service ‘Find My Past’ – which was previously assigned numerical codes (the pst system). The study expands the existing data analysis on the occupational structure of England and Wales by introducing three further variables: the gender of the surveyed individuals, their age, and the shares of the inactive population per gender and age groups. [less ▲]

The association of adolescents' mental health with oral health behavior: The Luxembourg Health Behavior in School-Aged Children study

in Frontiers in Dental Medicine (2022)

Mindfulness extends the trans-contextual model for autonomous motivation in physical education and leisuretime

in International Journal of Environmental Research and Public Health (2022), 19(20),

Mindfulness is assumed to foster the ability to consistently act in line with one’s authentic self; a skill which has been found to enhance students’ autonomous motivated behavior in the educational ... [more ▼]

Mindfulness is assumed to foster the ability to consistently act in line with one’s authentic self; a skill which has been found to enhance students’ autonomous motivated behavior in the educational context. However, evidence regarding how mindfulness can be integrated into existing conceptual frameworks such as the trans-contextual model is scarce. Therefore, the present study aimed to evaluate the role of mindfulness in students’ autonomous motivation in the school and leisure time contexts. Overall, N = 1877 students (M = 14.74 years, SD = 2.63) indicated their self-reported mindfulness, their perceived need for support in physical education, their autonomous motivation during physical education and leisure time, as well as their perceived behavioral control, attitude, subjective norm, and intention toward physical activity. Physical activity was additionally measured physiologically for n = 240 students using accelerometers. Path model analyses revealed that the inclusion of mindfulness substantially improved the trans-contextual model fit. Perceived autonomy support positively predicted mindfulness, which, in turn, predicted autonomous motivation in physical education and leisure time, attitude, subjective norm, and perceived behavioral control. Furthermore, mediation analyses revealed the significant indirect effects of mindfulness on physiological and self-reported physical activity. Based on these results, mindfulness can be considered a key factor in fostering students’ motivation to become physically active. [less ▲]

RNetDys: identification of disease-related impaired regulatory interactions due to SNPs

in bioRxiv (2022)

On the Performance of Cache-Free/Cache-Aided STBC-NOMA in Cognitive Hybrid Satellite-Terrestrial Networks

in IEEE Wireless Communications Letters (2022), 11(12), 2655-2659

Future wireless networks pose several challenges such as high spectral efficiency, wide coverage massive connectivity, low receiver complexity, etc. To this end, this letter investigates an overlay based ... [more ▼]

Future wireless networks pose several challenges such as high spectral efficiency, wide coverage massive connectivity, low receiver complexity, etc. To this end, this letter investigates an overlay based cognitive hybrid satellite-terrestrial network (CHSTN) combining non-orthogonal multiple access (NOMA) and conventional Alamouti space-time block coding (STBC) techniques. Herein, a decode-and-forward based secondary terrestrial network cooperates with a primary satellite network for dynamic spectrum access. Further, for reliable content delivery and low latency requirements, wireless caching is employed, whereby the secondary network can store the most popular contents of the primary network. Considering the relevant heterogeneous fading channel models and the NOMA-based imperfect successive interference cancellation, we examine the performance of CHSTN for the cache-free (CF) STBC-NOMA and the cache-aided (CA) STBC-NOMA schemes. We assess the outage probability expressions for primary and secondary networks and further, highlight the corresponding achievable diversity orders. Indicatively, the proposed CF/CA STBC-NOMA schemes for CHSTN perform significantly better than the benchmark standalone NOMA and OMA schemes. [less ▲]

The associations of dietary habits with health, well-being, and behavior in adolescents: A cluster analysis

in Child: Care, Health and Development (2022)

A Conjecture on Primes in Arithmetic Progressions and Geometric Intervals

in American Mathematical Monthly (2022), 129(10), 979-983

Dirichlet’s theorem on primes in arithmetic progressions states that for any positive integer q and any coprime integer a, there are infinitely many primes in the arithmetic progression a + nq (n ∈ N ... [more ▼]

Dirichlet’s theorem on primes in arithmetic progressions states that for any positive integer q and any coprime integer a, there are infinitely many primes in the arithmetic progression a + nq (n ∈ N). Unfortunately, the theorem does not predict the gap between those primes. Several renowned open questions such as the size of Linnik’s constant try to say more about the distribution of such primes. This manuscript postulates a weak, but explicit, generalization of Linnik’s theorem, namely that each geometric interval [q^t, q^(t+1)] contains a prime from each coprime congruence class modulo q ∈ N≥2. Subsequently, it proves the conjecture theoretically for all sufficiently large t, as well as computationally for all sufficiently small q. Finally, the impact of this conjecture on a result of Pomerance related to Carmichael’s conjecture is outlined. [less ▲]

A Deep Learning Approach for Reconstruction in Millimeter-Wave Imaging Systems

in IEEE Transactions on Antennas and Propagation (2022)

In millimeter-wave (MMW) imaging, the objects of interest are oftentimes modeled as 2D binary (black and white) shapes with white pixels representing the reflecting interior of the object. However, due to ... [more ▼]

In millimeter-wave (MMW) imaging, the objects of interest are oftentimes modeled as 2D binary (black and white) shapes with white pixels representing the reflecting interior of the object. However, due to propagation of the scattered waves, the continuous-domain binary images are convolved with a so-called point-spread function (PSF) before being digitized by means of sampling. As the 2D PSF is both non-separable and non-vanishing in the case of MMW imaging, exact recovery is quite complicated. In this paper, we propose a deep learning approach for image reconstruction. We should highlight that the wave scatterings are suitably represented with complex-valued quantities, while standard deep neural networks (DNN) accept real-valued inputs. To overcome this challenge, we separate the real and imaginary parts as if we had two imaging modalities and concatenate them to form a real-valued input with larger size. Fortunately, the network automatically learns how to combine the mutual information between these modalities to reconstruct the final image. Among the advantages of the proposed method are improved robustness against additive noise and mismatch errors of imaging frequency and object to antenna distance; indeed, the method works well in wide-band imaging scenarios over a wide range of object to antenna distances even in presence of high noise levels without requiring a separate calibration stage. We test the method with synthetic data simulated with software as well as real recordings in the laboratory. [less ▲]

Cambridge hybrid closed-loop system in very young children with type 1 diabetes reduces caregivers’ fear of hypoglycemia and improves their well-being

in Diabetes Care (2022), 45

Objective To evaluate the impact of CamAPS FX hybrid closed-loop automated insulin delivery (HCL) in very young children with type 1 diabetes (T1D) on caregivers’ well-being, fear of hypoglycemia and ... [more ▼]

Objective To evaluate the impact of CamAPS FX hybrid closed-loop automated insulin delivery (HCL) in very young children with type 1 diabetes (T1D) on caregivers’ well-being, fear of hypoglycemia and sleepiness. Research Design Multinational, open label, randomized crossover study. Children (1-7years) with T1D received treatment for two 4-month periods in random order, comparing HCL with sensor augmented pump (SAP) (control). At baseline and after each treatment period, caregivers were invited to complete WHO-5, Hypoglycemia Fear Survey (HFS) and Epworth Sleepiness Scale (ESS). Results Caregivers of 74 children (mean±SD: age 5±2 years; 42% female, baseline HbA1c 7.3±0.7%) participated. Results revealed significantly lower scores for hypoglycemia fear (p<.001) and higher for well-being (p<.001) after HCL treatment. A trend towards a reduction in sleepiness score was observed (p=0.09). Conclusion Our results suggest a better well-being and less hypoglycemia fear in caregivers of very young children with T1D on CamAPS FX HCL. [less ▲]

Sine-skewed toroidal distributions and their application in protein bioinformatics

in Biostatistics (2022), 23(3), 685704

In the bioinformatics field, there has been a growing interest in modeling dihedral angles of amino acids by viewing them as data on the torus. This has motivated, over the past years, new proposals of ... [more ▼]

In the bioinformatics field, there has been a growing interest in modeling dihedral angles of amino acids by viewing them as data on the torus. This has motivated, over the past years, new proposals of distributions on the torus. The main drawback of most of these models is that the related densities are (pointwise) symmetric, despite the fact that the data usually present asymmetric patterns. This motivates the need to find a new way of constructing asymmetric toroidal distributions starting from a symmetric distribution. We tackle this problem in this article by introducing the sine-skewed toroidal distributions. The general properties of the new models are derived. Based on the initial symmetric model, explicit expressions for the shape and dependence measures are obtained, a simple algorithm for generating random numbers is provided, and asymptotic results for the maximum likelihood estimators are established. An important feature of our construction is that no extra normalizing constant needs to be calculated, leading to more flexible distributions without increasing the complexity of the models. The benefit of employing these new sine-skewed toroidal distributions is shown on the basis of protein data, where, in general, the new models outperform their symmetric antecedents. [less ▲]

Which Factors Play a Role in Coco Issuance? Evidence from European Banks.

in Journal of Derivatives (2022), (Fall),

Le projet de Code de droit international privé sous l'angle de la reconnaissance des sociétés

in Bulletin Joly Sociétés (2022)

Mutation Analysis for Cyber-Physical Systems: Scalable Solutions and Results in the Space Domain

in IEEE Transactions on Software Engineering (2022), 48(10), 39133939

On-board embedded software developed for spaceflight systems (space software) must adhere to stringent software quality assurance procedures. For example, verification and validation activities are ... [more ▼]

On-board embedded software developed for spaceflight systems (space software) must adhere to stringent software quality assurance procedures. For example, verification and validation activities are typically performed and assessed by third party organizations. To further minimize the risk of human mistakes, space agencies, such as the European Space Agency (ESA), are looking for automated solutions for the assessment of software testing activities, which play a crucial role in this context. Though space software is our focus here, it should be noted that such software shares the above considerations, to a large extent, with embedded software in many other types of cyber-physical systems. Over the years, mutation analysis has shown to be a promising solution for the automated assessment of test suites; it consists of measuring the quality of a test suite in terms of the percentage of injected faults leading to a test failure. A number of optimization techniques, addressing scalability and accuracy problems, have been proposed to facilitate the industrial adoption of mutation analysis. However, to date, two major problems prevent space agencies from enforcing mutation analysis in space software development. First, there is uncertainty regarding the feasibility of applying mutation analysis optimization techniques in their context. Second, most of the existing techniques either can break the real-time requirements common in embedded software or cannot be applied when the software is tested in Software Validation Facilities, including CPU emulators and sensor simulators. In this paper, we enhance mutation analysis optimization techniques to enable their applicability to embedded software and propose a pipeline that successfully integrates them to address scalability and accuracy issues in this context, as described above. Further, we report on the largest study involving embedded software systems in the mutation analysis literature. Our research is part of a research project funded by ESA ESTEC involving private companies (GomSpace Luxembourg and LuxSpace) in the space sector. These industry partners provided the case studies reported in this paper; they include an on-board software system managing a microsatellite currently on-orbit, a set of libraries used in deployed cubesats, and a mathematical library certified by ESA. [less ▲]

Chronique de droit européen de la consommation 2021 – 2022

in Journal de Droit Européen (2022)

Overview and critical analysis of relevant political decisions, newly passed legislation and all jugements rendered by the CJEU in the field of European consumer law.

Learning-Based Resource Allocation for Backscatter-Aided Vehicular Networks

in IEEE Transactions on Intelligent Transportation Systems (2022)

Heterogeneous backscatter networks are emerging as a promising solution to address the proliferating coverage and capacity demands of next-generation vehicular networks. However, despite its rapid ... [more ▼]

Heterogeneous backscatter networks are emerging as a promising solution to address the proliferating coverage and capacity demands of next-generation vehicular networks. However, despite its rapid evolution and significance, the optimization aspect of such networks has been overlooked due to their complexity and scale. Motivated by this discrepancy in the literature, this work sheds light on a novel learning-based optimization framework for heterogeneous backscatter vehicular networks. More specifically, the article presents a resource allocation and user association scheme for large-scale heterogeneous backscatter vehicular networks by considering a collaboration centric spectrum sharing mechanism. In the considered network setup, multiple network service providers (NSPs) own the resources to serve several legacy and backscatter vehicular users in the network. For each NSP, the legacy vehicle user operates under the macro cell, whereas, the backscatter vehicle user operates under small private cells using leased spectrum resources. A joint power allocation, user association, and spectrum sharing problem has been formulated with an objective to maximize the utility of NSPs. In order to overcome challenges of high dimensionality and non-convexity, the problem is divided into two subproblems. Subsequently, a reinforcement learning and a supervised deep learning approach have been used to solve both subproblems in an efficient and effective manner. To evaluate the benefits of the proposed scheme, extensive simulation studies are conducted and a comparison is provided with benchmark techniques. The performance evaluation demonstrates the utility of the presented system architecture and learning-based optimization framework. [less ▲]

The Devil is in the Details: Unwrapping the Cryptojacking Malware Ecosystem on Android

in 2022 IEEE 22nd International Working Conference on Source Code Analysis and Manipulation (SCAM) (2022)

This paper investigates the various technical and non-technical tools and techniques that software developers use to build and disseminate crypto mining apps on Android devices. Our study of 346 potential ... [more ▼]

This paper investigates the various technical and non-technical tools and techniques that software developers use to build and disseminate crypto mining apps on Android devices. Our study of 346 potential Android mining apps, collected between April 2019 and May 2022, has revealed the presence of more than ten mining apps on the Google Play Store, with at least half of those still available at the time of writing this (June 2022). We observed that many of those mining apps do not conceal their usage of the device’s resource for mining which is considered a violation of the store’s policies for developers. We estimate that more than ten thousand users have run mining apps downloaded directly from the Google Play Store, which puts the supposedly ”stringent” vetting process into question. Furthermore, we prove that covert mining apps tend to be embedded into supposedly free versions of premium apps or pose as utility apps that provide valuable features to users. Finally, we empirically demonstrate that cryptojacking apps’ resource consumption and malicious behavior could be insignificant. We presume that typical users, even though they might be running a mobile antivirus solution, could execute a mining app for an extended period without being alerted. We expect our results to inform the various actors involved in the security of Android devices against the lingering threat of cryptojacking and help them better assess the problem. [less ▲]

Creating active urban environments: insights from expert interviews

in Cities & Health (2022)

Urban planning and design offer opportunities to nudge people towards more active behavior. This is a popular topic among urbanists and health professionals, with several guidelines and best practices ... [more ▼]

Urban planning and design offer opportunities to nudge people towards more active behavior. This is a popular topic among urbanists and health professionals, with several guidelines and best practices already developed. However, a gap exists between theory and practice and the complex realization process of such active environments is rarely documented. In this study, we investigated the process of designing, implementing, and evaluating active urban environments through semi-structured interviews with 11 European practitioner experts in the field of active environment design and development. We additionally analyzed 51 examples of active environments they provided. We discuss definitions of active environments and their added value to encourage active behavior and provide an overview of the spectrum of design strategies, elements and boundaries used to create them. We also describe typical steps in the design and realization process, including types of stakeholders, main gaps, and points of friction in this practice [less ▲]

Le lieu d'établissement de la société déclarée en faillite, critère de compétence pour l'action en responsabilité extracontractuelle introduite par le syndic à l'encontre de la société "grand mère" de la société débitrice

in Revue des Procédures Collectives Civiles et Commerciales (2022)

La circonstance qu'un salarié exerce une fonction de direction sociale ne le prive pas de la protection offerte par la directive 2008/94/CE

in Revue des Procédures Collectives Civiles et Commerciales (2022)

One Step Closer to Space Security: The Role of Multilateral Discussions

in Global Policy - Observer Research Foundation (ORF) Series (2022)

Rethinking commonality in refugee status determination in Europe: Legal geographies of asylum appeals

in Political Geography (2022), 98

The Common European Asylum System aims to establish common standards for refugee status determination among EU Member States. Combining insights from legal and political geography we bring the depth and ... [more ▼]

The Common European Asylum System aims to establish common standards for refugee status determination among EU Member States. Combining insights from legal and political geography we bring the depth and scale of this challenge into sharp relief. Drawing on interviews and a detailed ethnography of asylum adjudication involving over 850 in-person asylum appeal observations, we point towards practical differences in the spatio-temporality, materiality and logistics of asylum appeal processes as they are operationalised in seven European countries. Our analysis achieves three things. Firstly, we identify a key zone of differences at the level of concrete, everyday implementation that has largely escaped academic attention, which allows us to critically assess the notion of harmonisation of asylum policies in new ways. Secondly, drawing on legal- and political-geographical concepts, we offer a way to conceptualise this zone by paying attention to the spatio-temporality, materiality and logistics it involves. Thirdly, we offer critical legal logistics as a new direction for scholarship in legal geography and beyond that promises to prise open the previously obscured mechanics of contemporary legal systems. [less ▲]

Beam Squint-Aware Integrated Sensing and Communications for Hybrid Massive MIMO LEO Satellite Systems

in IEEE Journal on Selected Areas in Communications (2022), 40(10), 2994-3009

The space-air-ground-sea integrated network (SAGSIN) plays an important role in offering global coverage. To improve the efficient utilization of spectral and hardware resources in the SAGSIN, integrated ... [more ▼]

The space-air-ground-sea integrated network (SAGSIN) plays an important role in offering global coverage. To improve the efficient utilization of spectral and hardware resources in the SAGSIN, integrated sensing and communications (ISAC) has drawn extensive attention. Most existing ISAC works focus on terrestrial networks and cannot be straightforwardly applied in satellite systems due to the significantly different electromagnetic wave propagation properties. In this work, we investigate the application of ISAC in massive multiple-input multiple-output (MIMO) low earth orbit (LEO) satellite systems. We first characterize the statistical wave propagation properties by considering beam squint effects. Based on this analysis, we propose a beam squint-aware ISAC technique for hybrid analog/digital massive MIMO LEO satellite systems exploiting statistical channel state information. Simulation results demonstrate that the proposed scheme can operate both the wireless communications and the target sensing simultaneously with satisfactory performance, and the beam-squint effects can be efficiently mitigated with the proposed method in typical LEO satellite systems. [less ▲]

Automated, Cost-effective, and Update-driven App Testing

in ACM Transactions on Software Engineering and Methodology (2022), 31(4), 61

Apps’ pervasive role in our society led to the definition of test automation approaches to ensure their dependability. However, state-of-the-art approaches tend to generate large numbers of test inputs ... [more ▼]

Apps’ pervasive role in our society led to the definition of test automation approaches to ensure their dependability. However, state-of-the-art approaches tend to generate large numbers of test inputs and are unlikely to achieve more than 50% method coverage. In this paper, we propose a strategy to achieve significantly higher coverage of the code affected by updates with a much smaller number of test inputs, thus alleviating the test oracle problem. More specifically, we present ATUA, a model-based approach that synthesizes App models with static analysis, integrates a dynamically-refined state abstraction function, and combines complementary testing strategies, including (1) coverage of the model structure, (2) coverage of the App code, (3) random exploration, and (4) coverage of dependencies identified through information retrieval. Its model-based strategy enables ATUA to generate a small set of inputs that exercise only the code affected by the updates. In turn, this makes common test oracle solutions more cost-effective as they tend to involve human effort. A large empirical evaluation, conducted with 72 App versions belonging to nine popular Android Apps, has shown that ATUA is more effective and less effort-intensive than state-of-the-art approaches when testingApp updates. [less ▲]

Cahiers de fiscalité luxembourgeoise et européenne - 2022/2

in Cahiers de fiscalité luxembourgeoise et européenne (2022), 1(2), 245

Les Cahiers de fiscalité luxembourgeoise et européenne offrent une analyse rigoureuse et thématique du droit fiscal luxembourgeois. Associant les exigences de la recherche scientifique à la réalité de la ... [more ▼]

Les Cahiers de fiscalité luxembourgeoise et européenne offrent une analyse rigoureuse et thématique du droit fiscal luxembourgeois. Associant les exigences de la recherche scientifique à la réalité de la pratique administrative luxembourgeoise, les Cahiers proposent deux fois par an une sélection d'analyses doctrinales rédigées par des experts luxembourgeois et étrangers. Chaque numéro des Cahiers se fait également le reflet d'une analyse systémique de la jurisprudence fiscale la plus récente au niveau national - contributions directes (juridictions administratives) et fiscalité indirecte (juridictions judiciaires) - et au niveau supranational (CJUE, CEDH). La recherche en droit fiscal luxembourgeois étant au coeur de ce projet collectif éditorial, les Cahiers publient régulièrement des actes de colloques, des extraits de thèses de doctorat récemment soutenues et un travail pluriannuel de rédaction de commentaires de la loi générale des impôts (Abgabenordnung). [less ▲]

Between universalism and cultural relativism The dilemma of consent to female genital mutilation in the Tatu Kamau case

in Kabarak Journal of Law and Ethics (2022), 6(1), 67-98

To date, almost 74 years since the adoption of the Universal Declaration of Human Rights (the UDHR), the tensions between universalism and cultur-al relativism in the field of human rights, whose ... [more ▼]

To date, almost 74 years since the adoption of the Universal Declaration of Human Rights (the UDHR), the tensions between universalism and cultur-al relativism in the field of human rights, whose provenance can be traced back to the debates surrounding the drafting and adoption of the UDHR, still linger on, playing out on the national stage in countries such as Kenya. At its core, universalism argues that all human rights inhere in all individ-uals without distinction, and that they must stand even when in when in opposition to established cultural practices. In contrast, cultural relativism holds that no particular culture is superior to another, and centers on the need for forbearance and respect towards each culture to avoid imperialist tendencies of imposing beliefs. This paper argues that these binary ideolog-ical viewpoints are magnified in the context of female genital mutilation. Through an analysis of the case of Tatu Kamau v Attorney General & 2 others; Equality Now & 9 others (Interested Parties);Katiba Institute & another (amicus curiae) [2021] eKLR, it is proposed that a cultural ap-proach is needed in addition to legal measures in place to combat the practice. [less ▲]

Stretching directions in cislunar space: Applications for departures and transfer design

in Astrodynamics (2022)

Stable or nearly stable orbits do not generally possess well-distinguished manifold structures that assist in designing trajectories for departing from or arriving onto a periodic orbit. For some ... [more ▼]

Stable or nearly stable orbits do not generally possess well-distinguished manifold structures that assist in designing trajectories for departing from or arriving onto a periodic orbit. For some potential missions, the orbits of interest are selected as nearly stable to reduce the possibility of rapid departure. However, the linearly stable nature of these orbits is also a drawback for their timely insertion into or departure from the orbit. Stable or nearly stable Near Rectilinear Halo Orbits (NRHOs), Distant Retrograde Orbits (DROs), and lunar orbits offer potential long-horizon trajectories for exploration missions and demand efficient operations. The current investigation focuses on leveraging stretching directions as a tool for departure and trajectory design applications. The magnitude of the state variations along the maximum stretching direction is expected to grow rapidly and, therefore, offers information for efficient departure from the orbit. Similarly, maximum stretching in reverse time enables arrival with a minimal maneuver magnitude. [less ▲]

Item response theory and differential test functioning analysis of the HBSC-Symptom-Checklist across 46 countries

in BMC Medical Research Methodology (2022), 22(253),

Background The Symptom Checklist (SCL) developed by the Health Behaviour in School-aged Children (HBSC) study is a non-clinical measure of psychosomatic complaints (e.g., headache and feeling low) that ... [more ▼]

Background The Symptom Checklist (SCL) developed by the Health Behaviour in School-aged Children (HBSC) study is a non-clinical measure of psychosomatic complaints (e.g., headache and feeling low) that has been used in numerous studies. Several studies have investigated the psychometric characteristics of this scale; however, some psychometric properties remain unclear, among them especially a) dimensionality, b) adequacy of the Graded Response Model (GRM), and c) measurement invariance across countries. Methods Data from 229,906 adolescents aged 11, 13 and 15 from 46 countries that participated in the 2018 HBSC survey were analyzed. Adolescents were selected using representative sampling and surveyed by questionnaire in the classroom. Dimensionality was investigated using exploratory graph analysis. In addition, we investigated whether the GRM provided an adequate description of the data. Reliability over the latent variable continuum and differential test functioning across countries were also examined. Results Exploratory graph analyses showed that SCL can be considered as one-dimensional in 16 countries. However, a comparison of the unidimensional with a post-hoc bifactor GRM showed that deviation from a hypothesized one-dimensional structure was negligible in most countries. Multigroup invariance analyses supported configural and metric invariance, but not scalar invariance across 32 countries. Alignment analysis showed non-invariance especially for the items irritability, feeling nervous/bad temper and feeling low. Conclusion HBSC-SCL appears to represent a consistent and reliable unidimensional instrument across most countries. This bodes well for population health analyses that rely on this scale as an early indicator of mental health status. [less ▲]

Learning from what we know: How to perform vulnerability prediction using noisy historical data

in Empirical Software Engineering (2022)

Mobilome-driven segregation of the resistome in biological wastewater treatment

in eLife (2022), 11

Biological wastewater treatment plants (BWWTP) are considered to be hotspots of evolution and subsequent spread of antimicrobial resistance (AMR). Mobile genetic elements (MGEs) promote the mobilization ... [more ▼]

Biological wastewater treatment plants (BWWTP) are considered to be hotspots of evolution and subsequent spread of antimicrobial resistance (AMR). Mobile genetic elements (MGEs) promote the mobilization and dissemination of antimicrobial resistance genes (ARGs) and are thereby critical mediators of AMR within the BWWTP microbial community. At present, it is unclear whether specific AMR categories are differentially disseminated via bacteriophages (phages) or plasmids. To understand the segregation of AMR in relation to MGEs, we analyzed meta-omic (metagenomic, metatranscriptomic and metaproteomic) data systematically collected over 1.5 years from a BWWTP. Our results showed a core group of fifteen AMR categories which were found across all timepoints. Some of these AMR categories were disseminated exclusively (bacitracin) or primarily (aminoglycoside, MLS and sulfonamide) via plasmids or phages (fosfomycin and peptide), whereas others were disseminated equally by both MGEs. Combined and timepoint-specific analyses of gene, transcript and protein abundances further demonstrated that aminoglycoside, bacitracin and sulfonamide resistance genes were expressed more by plasmids, in contrast to fosfomycin and peptide AMR expression by phages, thereby validating our genomic findings. In the analyzed communities, the dominant taxon Candidatus Microthrix parvicella was a major contributor to several AMR categories whereby its plasmids primarily mediated aminoglycoside resistance. Importantly, we also found AMR associated with ESKAPEE pathogens within the BWWTP, for which MGEs also contributed differentially to the dissemination of ARGs. Collectively our findings pave the way towards understanding the segmentation of AMR within MGEs, thereby shedding new light on resistome populations and their mediators, essential elements that are of immediate relevance to human health. [less ▲]

Tussen New York en Genève: VN-Kroniek

in Nederlands Tijdschrift voor de Mensenrechten (2022), 47(3),

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene ... [more ▼]

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene Vergadering en de Mensenrechtenraad) aan de orde, als de diverse verdragscomités. [less ▲]

The gut microbiome molecular complex in human health and disease

in Cell Host and Microbe (2022), 30(9), 1201-1206

The human gut microbiome produces a functional complex of biomolecules, including nucleic acids, (poly) peptides, structural molecules, and metabolites. This impacts human physiology in multiple ways ... [more ▼]

The human gut microbiome produces a functional complex of biomolecules, including nucleic acids, (poly) peptides, structural molecules, and metabolites. This impacts human physiology in multiple ways, especially by triggering inflammatory pathways in disease. At present, much remains to be learned about the identity of key effectors and their causal roles. [less ▲]

Efficient Matching-Based Parallel Task Offloading in IoT Networks

in Sensors (2022)

Fog computing is one of the major components of future 6G networks. It can provide fast computing of different application-related tasks and improve system reliability due to better decision-making ... [more ▼]

Fog computing is one of the major components of future 6G networks. It can provide fast computing of different application-related tasks and improve system reliability due to better decision-making. Parallel offloading, in which a task is split into several sub-tasks and transmitted to different fog nodes for parallel computation, is a promising concept in task offloading. Parallel offloading suffers from challenges such as sub-task splitting and mapping of sub-tasks to the fog nodes. In this paper, we propose a novel many-to-one matching-based algorithm for the allocation of sub-tasks to fog nodes. We develop preference profiles for IoT nodes and fog nodes to reduce the task computation delay. We also propose a technique to address the externalities problem in the matching algorithm that is caused by the dynamic preference profiles. Furthermore, a detailed evaluation of the proposed technique is presented to show the benefits of each feature of the algorithm. Simulation results show that the proposed matching-based offloading technique outperforms other available techniques from the literature and improves task latency by 52% at high task loads. [less ▲]

Nanoluciferase-based cell fusion assay for rapid and high-throughput assessment of SARS-CoV-2-neutralizing antibodies in patient samples.

in Methods in enzymology (2022), 675

After more than two years, COVID-19 still represents a global health burden of unprecedented extent and assessing the degree of immunity of individuals against SARS-CoV-2 remains a challenge. Virus ... [more ▼]

After more than two years, COVID-19 still represents a global health burden of unprecedented extent and assessing the degree of immunity of individuals against SARS-CoV-2 remains a challenge. Virus neutralization assays represent the gold standard for assessing antibody-mediated protection against SARS-CoV-2 in sera from recovered and/or vaccinated individuals. Neutralizing antibodies block the interaction of viral spike protein with human angiotensin-converting enzyme 2 (ACE2) receptor in vitro and prevent viral entry into host cells. Classical viral neutralization assays using full replication-competent viruses are restricted to specific biosafety level 3-certified laboratories, limiting their utility for routine and large-scale applications. We developed therefore a cell-fusion-based assay building on the interaction between viral spike and ACE2 receptor expressed on two different cell lines, substantially reducing biosafety risks associated with classical viral neutralization assays. This chapter describes this simple, sensitive, safe and cost-effective approach for rapid and high-throughput evaluation of SARS-CoV-2 neutralizing antibodies relying on high-affinity NanoLuc® luciferase complementation technology (HiBiT). When applied to a variety of standards and patient samples, this method yields highly reproducible results in 96-well, as well as in 384-well format. The use of novel NanoLuc® substrates with increased signal stability like Nano-Glo® Endurazine™ furthermore allows for high flexibility in assay set-up and full automatization of all reading processes. Lastly, the assay is suitable to evaluate the neutralizing capacity of sera against the existing spike variants, and potentially variants that will emerge in the future. [less ▲]

Genotype-phenotype correlations in SCN8A-related disorders reveal prognostic and therapeutic implications

in Brain (2022)

We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel NaV1.6, with the aim of ... [more ▼]

We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel NaV1.6, with the aim of describing clinical phenotypes related to functional effects. Six different clinical subgroups could be identified: 1) Benign familial infantile epilepsy (BFIE) (n = 15, normal cognition, treatable seizures), 2) intermediate epilepsy (n = 33, mild ID, partially pharmaco-responsive), 3) developmental and epileptic encephalopathy (DEE, n = 177, severe ID, majority pharmaco-resistant), 4) generalized epilepsy (n = 20, mild to moderate ID, frequently with absence seizures), 5) unclassifiable epilepsy (n = 127), and 6) neurodevelopmental disorder without epilepsy (n = 20, mild to moderate ID). Groups 1–3 presented with focal or multifocal seizures (median age of onset: four months) and focal epileptiform discharges, whereas the onset of seizures in group 4 was later (median: 42 months) with generalized epileptiform discharges. We performed functional studies expressing missense variants in ND7/23 neuroblastoma cells and primary neuronal cultures using recombinant tetrodotoxin-insensitive human NaV1.6 channels and whole-cell patch-clamping. Two variants causing DEE showed a strong gain-of-function (GOF, hyperpolarising shift of steady-state activation, strongly increased neuronal firing rate), and one variant causing BFIE or intermediate epilepsy showed a mild GOF (defective fast inactivation, less increased firing). In contrast, all three variants causing generalized epilepsy induced a loss-of-function (LOF, reduced current amplitudes, depolarising shift of steady-state activation, reduced neuronal firing). Including previous studies, functional effects were known for 170 individuals. All 136 individuals carrying a functionally tested GOF variant had either focal (97, groups 1–3), or unclassifiable epilepsy (39), whereas 34 with a LOF variant had either generalized (14), no (11) or unclassifiable (6) epilepsy; only three had DEE. Computational modeling in the GOF group revealed a significant correlation between the severity of the electrophysiological and clinical phenotypes. GOF variant carriers responded significantly better to sodium channel blockers (SCBs) than to other anti-seizure medications, and the same applied for all individuals of groups 1–3.In conclusion, our data reveal clear genotype-phenotype correlations between age at seizure onset, type of epilepsy and gain- or loss-of-function effects of SCN8A variants. Generalized epilepsy with absence seizures is the main epilepsy phenotype of LOF variant carriers and the extent of the electrophysiological dysfunction of the GOF variants is a main determinant of the severity of the clinical phenotype in focal epilepsies. Our pharmacological data indicate that SCBs present a treatment option in SCN8A-related focal epilepsy with onset in the first year of life. [less ▲]

Loss-of-function variants in the KCNQ5 gene are implicated in genetic generalized epilepsies

in eBioMedicine (2022), 84

Summary Background De novo missense variants in KCNQ5, encoding the voltage-gated K+ channel KV7.5, have been described to cause developmental and epileptic encephalopathy (DEE) or intellectual disability ... [more ▼]

Summary Background De novo missense variants in KCNQ5, encoding the voltage-gated K+ channel KV7.5, have been described to cause developmental and epileptic encephalopathy (DEE) or intellectual disability (ID). We set out to identify disease-related KCNQ5 variants in genetic generalized epilepsy (GGE) and their underlying mechanisms. Methods 1292 families with GGE were studied by next-generation sequencing. Whole-cell patch-clamp recordings, biotinylation and phospholipid overlay assays were performed in mammalian cells combined with homology modelling. Findings We identified three deleterious heterozygous missense variants, one truncation and one splice site alteration in five independent families with GGE with predominant absence seizures; two variants were also associated with mild to moderate ID. All missense variants displayed a strongly decreased current density indicating a loss-of-function (LOF). When mutant channels were co-expressed with wild-type (WT) KV7.5 or KV7.5 and KV7.3 channels, three variants also revealed a significant dominant-negative effect on WT channels. Other gating parameters were unchanged. Biotinylation assays indicated a normal surface expression of the variants. The R359C variant altered PI(4,5)P2-interaction. Interpretation Our study identified deleterious KCNQ5 variants in GGE, partially combined with mild to moderate ID. The disease mechanism is a LOF partially with dominant-negative effects through functional deficits. LOF of KV7.5 channels will reduce the M-current, likely resulting in increased excitability of KV7.5-expressing neurons. Further studies on network level are necessary to understand which circuits are affected and how this induces generalized seizures. Funding DFG/FNR Research Unit FOR-2715 (Germany/Luxemburg), BMBF rare disease network Treat-ION (Germany), foundation ‘no epilep’ (Germany). [less ▲]

Metaphenotypes associated with recurrent genomic lineages of Campylobacter jejuni responsible for human infections in Luxembourg

in Frontiers in Microbiology (2022)

Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. Although considered fragile, this microaerophilic bacterium is able to survive in various challenging environments, which ... [more ▼]

Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. Although considered fragile, this microaerophilic bacterium is able to survive in various challenging environments, which subsequently constitutes multiple sources of transmission for human infection. To test the assumption of acquiring specific features for adaption and survivals we established a workflow of phenotypic tests related to the survival and the persistence of recurrent and sporadic strains. A representative collection of 83 strains isolated over 13 years from human, mammal, poultry, and environmental sources in Luxembourg, representing different spreading patterns (endemic, epidemic, and sporadic), was screened for survival to oxidative stresses, for acclimating to aerobic conditions (AC), and for persistence on abiotic surfaces. Using the cgMLST Oxford typing scheme for WGS data, the collection was classified into genomic lineages corresponding to host-generalist strains (lineages A and D, CC ST-21), host-specific strains (lineages B, CC ST-257 and lineage C, CC ST-464) and sporadic strains. We established that when a strain survives concentrations beyond 0.25 mM superoxide stress, it is six times more likely to survive hyperoxide stress and that a highly adherent strain is 14 times more likely to develop a biofilm. Surprisingly, more than half of the strains could acclimate to AC but this capacity does not explain the difference between recurrent genomic lineages and sporadic strains and the survival to oxidative stresses, while recurrent strains have a significantly higher adhesion/biofilm formation capacity than sporadic ones. From this work, the genomic lineages with more stable genomes could be characterized by a specific combination of phenotypes, called metaphenotypes. From the functional genomic analyses, the presence of a potentially functional T6SS in the strains of lineage D might explain the propensity of these strains to be strong biofilm producers. Our findings support the hypothesis that phenotypical abilities contribute to the spatio-temporal adaptation and survival of stable genomic lineages. It suggests a selection of better-adapted and persistent strains in challenging stress environments, which could explain the prevalence of these lineages in human infections. [less ▲]

Economic development, weather shocks and child marriage in South Asia: A machine learning approach

in PLoS ONE (2022), 17(9), 0271373

ChemPert: mapping between chemical perturbation and transcriptional response for non-cancer cells

in Nucleic Acids Research (2022)

Model-based valuation of smart grid initiatives: Foundations, open issues, requirements, and a research outlook

in Data and Knowledge Engineering (2022), 141

Alternative Object Use in Adults and Children: Embodied Cognitive Bases of Creativity

in Frontiers in Psychology (2022)

Why does one need creativity? On a personal level, improvisation with available resources is needed for online coping with unforeseen environmental stimuli when existing knowledge and apparent action ... [more ▼]

Why does one need creativity? On a personal level, improvisation with available resources is needed for online coping with unforeseen environmental stimuli when existing knowledge and apparent action strategies do not work. On a cultural level, the exploitation of existing cultural means and norms for the deliberate production of novel and valuable artifacts is a basis for cultural and technological development and extension of human action possibilities across various domains. It is less clear, however, how creativity develops and how exactly one arrives at generating new action possibilities and producing multiple alternative action strategies using familiar objects. In this theoretical paper, we first consider existing accounts of the creative process in the Alternative Uses Task and then present an alternative interpretation, drawing on sociocultural views and an embodied cognition approach. We explore similarities between the psychological processes underlying the generation of new uses in the Alternative Uses Task and children’s pretend play. We discuss possible cognitive mechanisms and speculate how the generation of new action possibilities for common objects in pretend play can be related to adults’ ability to generate new action strategies associated with object use. Implications for creativity development in humans and embodied artificial agents are discussed. [less ▲]

Limites et enjeux du travail à distance en contexte transfrontalier

in Entreprises Magazine (2022), 115

Le télétravail imposé par la pandémie n’est pas sans soulever un certain nombre de questions (juridiques, sociales, fiscales notamment) liées à la présence de la frontière entre le lieu de résidence et le ... [more ▼]

Le télétravail imposé par la pandémie n’est pas sans soulever un certain nombre de questions (juridiques, sociales, fiscales notamment) liées à la présence de la frontière entre le lieu de résidence et le lieu de travail. Par ailleurs, dans un contexte tendu par les problèmes de mobilité et de congestion, une autre forme de travail à distance tend à se développer ces dernières années: les espaces de Coworking. [less ▲]

Development and Validation of a Short Form of the Geriatric Anxiety Scale (GAS-12) among Italian Older Adults

in Clinical Gerontologist (2022)

RF Precoding for Cognitive Radio Systems

in IEEE Wireless Communications Letters (2022), 11(9), 1845-1849

In this letter, a precoding framework in the radio-frequency (RF) domain is developed for the downlink of a multiuser multiple-input single-output underlay cognitive radio (CR) system. Firstly, a low ... [more ▼]

In this letter, a precoding framework in the radio-frequency (RF) domain is developed for the downlink of a multiuser multiple-input single-output underlay cognitive radio (CR) system. Firstly, a low hardware complexity analog multiantenna architecture is proposed for the system’s transmitter. The proposed analog architecture is based on a phase-shifting network driven by an variable gain amplifier and has low power consumption since it avoids the use of energy hungry components such as digital-to-analog converters (DACs). Secondly, a novel RF precoder for the design of the transmit signals is developed such that the performance of the CR system is optimized and the constraints related to both the system’s architecture and the employed underlay CR paradigm are satisfied. The corresponding nonconvex and difficult optimization problem is formulated and solved via a novel algorithmic solution based on the saddle point method. The convergence of the proposed algorithmic solution is theoretically studied. The proposed approach is shown to be much more energy efficient than existing approaches based on fully digital transceivers. [less ▲]

Contrôler la dette publique pour garantir la paix. Quelques réflexions juridiques sur la modernité du 4e article préliminaire du projet de paix perpétuelle de Kant

in Estudos Kantianos (2022)

In the 'century of debt' that was the Enlightenment, Immanuel Kant was well aware of the pecuniary power that borrowing represents for any state and the realisation of its civil and/or military ambitions ... [more ▼]

In the 'century of debt' that was the Enlightenment, Immanuel Kant was well aware of the pecuniary power that borrowing represents for any state and the realisation of its civil and/or military ambitions. The 4th preliminary article of the Perpetual Peace Project forbids the use of debt for military purposes: "National debts must not be contracted in order to support the interests of the state outside". While he does not subscribe in every respect to Hume's pessimism about the very principle of public debt, Kant shares some of his criticisms. The hierarchy of types of debts established according to their modalities of constitution (internal/external financing, limited/unlimited) and their uses (civil/military) testifies to a series of axiological judgments on debt that suggest the basic elements of a legal regime of public debt. The present contribution aims at analysing the 4th preliminary article in the light of the economic, financial and political context of Prussia and other European states at the end of the 18th century. It compares Kant's position on public debt with those of his contemporaries (Hume, Diderot) and of the classical economists (Melon, Smith...). It also identifies the legal characteristics of Kant's framework of public debt and underlines its scope and limits. [less ▲]