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See detailOne-Dimensional Quantum Systems with Ground State of Jastrow Form Are Integrable
Yang, Jing UL; Del Campo Echevarria, Adolfo UL

in Physical Review Letters (2022)

Exchange operator formalism describes many-body integrable systems using phase-space variables involving an exchange operator that acts on any pair of particles. We establish an equivalence between models ... [more ▼]

Exchange operator formalism describes many-body integrable systems using phase-space variables involving an exchange operator that acts on any pair of particles. We establish an equivalence between models described by exchange operator formalism and the complete infinite family of parent Hamiltonians describing quantum many-body models with ground states of Jastrow form. This makes it possible to identify the invariants of motion for any model in the family and establish its integrability, even in the presence of an external potential. Using this construction we establish the integrability of the long-range Lieb-Liniger model, describing bosons in a harmonic trap and subject to contact and Coulomb interactions in one dimension.We further identify a variety of models exemplifying the integrability of Hamiltonians in this family. [less ▲]

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See detailCIRCULAR ARCHITECTURE: MODELS AND STRATEGIES TO REUSE AND RECYCLE BUILDINGS
Ferreira Silva, Marielle UL

Doctoral thesis (2022)

How we design, construct and live in our houses as well as go to work can mitigate carbon dioxide (CO2) emissions and global climate change. Furthermore, the complex world we live in is in an ongoing ... [more ▼]

How we design, construct and live in our houses as well as go to work can mitigate carbon dioxide (CO2) emissions and global climate change. Furthermore, the complex world we live in is in an ongoing transformation process. The housing shortage problem is increasing as the world population and cities are increasingly growing. Thereby, we must think of all the other issues that come along with population growth, such as increased demand for built space, mobility, expansion of cities into green areas, use of resources, and materials scarcity. Various projects from history have used alternatives to solve the problem of social housing, such as increasing density in cities through housing complexes, fast and low-cost constructions with prefabricated methods and materials, and modularisation systems. However, the current architecture is not designed to meet users’ future needs and reduce the environmental impact. A proposal to change this situation would be to go back to the beginning of architecture’s conception and to design it differently. In addition, nowadays, there is an increasing focus on moving towards sustainable and circular living spaces based on shared, adaptable and modular built environments to improve residents’ quality of life. For this reason, the main objective of this thesis is to study the potential of architecture that can reconfigure spatially and temporally, and produce alternative generic models to reuse and recycle architectural elements and spaces for functional flexibility through time. To approach the discussion, a documentary research methodology was applied to study the modular, prefabricated and ecological architectural typologies to address recyclability in buildings. The Atlas with case studies and architectural design strategies emerged from the analyses of projects from Durant to the 21st century. Furthermore, this thesis is a part of the research project Eco-Construction for Sustainable Development (ECON4SD), which is co-funded by the EU in partnership with the University of Luxembourg, and it presents three new generic building typologies. They are named according to their strong characteristics: Prototype 1 - Slab typology, a building designed as a concrete shelf structure in which timber housing units can be plugged in and out; Prototype 2 - Tower typology, a tower building with a flexible floor plan combining working and residential facilities with adjacent multi-purpose facilities; and Prototype 3 - Block typology, a structure characterised by the entire disassembly. The three new typologies combine modularity, prefabrication, flexibility and disassembly strategies to address the increasing demand for multi-use, reusable and resourceefficient housing units. The prototypes continually adapt to the occupants’ needs as the infrastructure incorporates repetition, exposed structure, central core, terrace, open floors, unfinished spaces, prefabrication, combined activities, and have reduced and different housing unit sizes, in which parts can be disassembled. They also densify the region that they are being implemented in. Moreover, the new circular typologies can offer more generous public and shared space for the occupants within the same building size as an ordinary building. The alternative design allows the reconversion of existing buildings or the reconstruction of the same buildings in other places reducing waste and increases its useful lifespan. Once the building is adapted and reused as much as possible, and the life cycle comes to an end, it can be disassembled, and the materials can be sorted for reusable or recyclable resources. The results demonstrate that circular architecture is feasible, realistic, adapts through time, increases material use, avoids unnecessary demolition, reduces construction waste and CO2 emissions and extends the useful life of the buildings. [less ▲]

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See detailL'espace frontalier franco-luxembourgeois vu depuis le Luxembourg
Brüll, Christoph UL

Scientific Conference (2022, October 02)

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See detailWhich Factors Play a Role in Coco Issuance? Evidence from European Banks.
Wolff, Christian UL

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

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See detailAus den Fehlern von Belval lernen
Scuto, Denis UL

Article for general public (2022)

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See detail'La situation de l'État luxembourgeois est autre': Entretien avec Michel Erpelding, spécialiste de l'histoire du droit international
Erpelding, Michel UL; Moes, Régis

Article for general public (2022)

This interview presents to the broader public the relationship between international law and colonial law, as well as the question of the responsibility of former colonial powers and states (such as ... [more ▼]

This interview presents to the broader public the relationship between international law and colonial law, as well as the question of the responsibility of former colonial powers and states (such as Luxembourg) that assisted these powers for colonial crimes. [less ▲]

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See detailThe EU's Digital Identity Policy: Tracing Policy Punctuations
Weigl, Linda UL; Amard, Alexandre UL; Fridgen, Gilbert UL et al

in Proceedings of the International Conference on Theory and Practice of Electronic Governance 2022 (2022, October)

This paper analyzes the development of the European Union’s digital identity policy. The analysis focuses on the dynamics leading to a sudden shift from identity management as a sensitive topic under ... [more ▼]

This paper analyzes the development of the European Union’s digital identity policy. The analysis focuses on the dynamics leading to a sudden shift from identity management as a sensitive topic under national competence towards a common, harmonized, user-centric European Digital Identity Framework layering on top of Member States’ existing systems. We adopted a syncretic approach to Punctuated Equilibrium Theory and focused specifically on the concept of policy punctuations and policy image. Process tracing is used as a method to trace and interpret causal mechanisms of policy processes. The empirical analysis is grounded in elite interviews and policy documentation. To open up the black box of policy-making, we analyze and disaggregate the policy process. We thereby provide a better understanding of the historical-political and technological mechanisms that determine particular policy outcomes. [less ▲]

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See detailRethinking commonality in refugee status determination in Europe: Legal geographies of asylum appeals
Gill, Nick; Hoellerer, Nicole; Allsopp, Jennifer et al

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 ▲]

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See detailEnhancing Rover Teleoperation on the Moon With Proprioceptive Sensors and Machine Learning Techniques
Coloma Chacon, Sofia UL; Martinez Luna, Carol UL; Yalcin, Baris Can UL et al

in IEEE Robotics and Automation Letters (2022)

Geological formations, environmental conditions, and soil mechanics frequently generate undesired effects on rovers’ mobility, such as slippage or sinkage. Underestimating these undesired effects may ... [more ▼]

Geological formations, environmental conditions, and soil mechanics frequently generate undesired effects on rovers’ mobility, such as slippage or sinkage. Underestimating these undesired effects may compromise the rovers’ operation and lead to a premature end of the mission. Minimizing mobility risks becomes a priority for colonising the Moon and Mars. However, addressing this challenge cannot be treated equally for every celestial body since the control strategies may differ; e.g. the low latency EarthMoon communication allows constant monitoring and controls, something not feasible on Mars. This letter proposes a Hazard Information System (HIS) that estimates the rover’s mobility risks (e.g. slippage) using proprioceptive sensors and Machine Learning (supervised and unsupervised). A Graphical User Interface was created to assist human-teleoperation tasks by presenting mobility risk indicators. The system has been developed and evaluated in the lunar analogue facility (LunaLab) at the University of Luxembourg. A real rover and eight participants were part of the experiments. Results demonstrate the benefits of the HIS in the decision-making processes of the operator’s response to overcome hazardous situations. [less ▲]

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See detailTowards the Application of Neuromorphic Computing to Satellite Communications
Ortiz Gomez, Flor de Guadalupe UL; Lagunas, Eva UL; Alves Martins, Wallace UL et al

in Towards the Application of Neuromorphic Computing to Satellite Communications (2022, October)

Artificial intelligence (AI) has recently received significant attention as a key enabler for future 5G-and-beyond terrestrial wireless networks. The applications of AI to satellite communications is also ... [more ▼]

Artificial intelligence (AI) has recently received significant attention as a key enabler for future 5G-and-beyond terrestrial wireless networks. The applications of AI to satellite communications is also gaining momentum to realize a more autonomous operation with reduced requirements in terms of human intervention. The adoption of AI for satellite communications will set new requirements on computing processors, which will need to support large workloads as efficiently as possible under harsh environmental conditions. In this context, neuromorphic processing (NP) is emerging as a bio-inspired solution to address pattern recognition tasks involving multiple, possibly unstructured, temporal signals and/or requiring continual learning. The key merits of the technology are energy efficiency and capacity for on-device adaptation. In this paper, we highlight potential use cases and applications of NP to satellite communications. We also explore major technical challenges for the implementation of space-based NP focusing on the available NP chipsets. [less ▲]

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See detailA multilingual dataset of COVID-19 vaccination attitudes on Twitter
Chen, Ninghan UL; Chen, Xihui UL; Pang, Jun UL

in Data in Brief (2022), 44

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See detailNon-Coherent Massive MIMO Integration in Satellite Communication
Monzon Baeza, Victor UL; Ha, Vu Nguyen UL; Querol, Jorge UL et al

Scientific Conference (2022, October)

Massive Multiple Input-Multiple Output (mMIMO) technique has been considered an efficient standard to improve the transmission rate significantly for the following wireless communication systems, such as ... [more ▼]

Massive Multiple Input-Multiple Output (mMIMO) technique has been considered an efficient standard to improve the transmission rate significantly for the following wireless communication systems, such as 5G and beyond. However, implementing this technology has been facing a critical issue of acquiring much channel state information. Primarily, this problem becomes more criticising in the integrated satellite and terrestrial networks (3GPP-Release 15) due to the countable high transmission delay. To deal with this challenging problem, the mMIMO-empowered non-coherent technique can be a promising solution. To our best knowledge, this paper is the first work considering employing the non-coherent mMIMO in satellite communication systems. This work aims to analyse the challenges and opportunities emerging with this integration. Moreover, we identified the issues in this conjunction. The preliminary results presented in this work show that the performance measured in bit error rate (BER) and the number of antennas are not far from that required for terrestrial links. Furthermore, thanks to mMIMO in conjunction with the non-coherent approach, we can work in a low signal-to-noise ratio (SNR) regime, which is an excellent advantage for satellite links. [less ▲]

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See detailPEELER: Learning to Effectively Predict Flakiness without Running Tests
Qin, Yihao; Wang, Shangwen; Liu, Kui et al

in Proceedings of the 38th IEEE International Conference on Software Maintenance and Evolution (2022, October)

—Regression testing is a widely adopted approach to expose change-induced bugs as well as to verify the correctness/robustness of code in modern software development settings. Unfortunately, the ... [more ▼]

—Regression testing is a widely adopted approach to expose change-induced bugs as well as to verify the correctness/robustness of code in modern software development settings. Unfortunately, the occurrence of flaky tests leads to a significant increase in the cost of regression testing and eventually reduces the productivity of developers (i.e., their ability to find and fix real problems). State-of-the-art approaches leverage dynamic test information obtained through expensive re-execution of test cases to effectively identify flaky tests. Towards accounting for scalability constraints, some recent approaches have built on static test case features, but fall short on effectiveness. In this paper, we introduce PEELER, a new fully static approach for predicting flaky tests through exploring a representation of test cases based on the data dependency relations. The predictor is then trained as a neural network based model, which achieves at the same time scalability (because it does not require any test execution), effectiveness (because it exploits relevant test dependency features), and practicality (because it can be applied in the wild to find new flaky tests). Experimental validation on 17,532 test cases from 21 Java projects shows that PEELER outperforms the state-of-the-art FlakeFlagger by around 20 percentage points: we catch 22% more flaky tests while yielding 51% less false positives. Finally, in a live study with projects in-the-wild, we reported to developers 21 flakiness cases, among which 12 have already been confirmed by developers as being indeed flaky. [less ▲]

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See detail„Denken-wie-üblich“: Eine Herausforderung für die kulturelle Vielfalt
Nonoa, Koku Gnatuloma UL

in JOURNAL geroRESEARCH (2022), 7

Der vorliegende Beitrag analysiert zunächst das Verhältnis zwischen dem „Denken-wie-üblich“ und dem klassischen Kulturbegriff mit Blick auf Repräsentations- und Identitätspolitik. Dann geht die Analyse ... [more ▼]

Der vorliegende Beitrag analysiert zunächst das Verhältnis zwischen dem „Denken-wie-üblich“ und dem klassischen Kulturbegriff mit Blick auf Repräsentations- und Identitätspolitik. Dann geht die Analyse auf die Herausforderungen des „Denkens-wie-üblich“ in der kulturellen Vielfalt ein. Schlie.lich wird herausgearbeitet, wie dies inDiskursen, Sprechakten und Narrativen zum Ausdruck kommt. [less ▲]

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See detailTransition Pathways towards Design Principles of Self-Sovereign Identity
Sedlmeir, Johannes; Huber, Jasmin; Barbereau, Tom Josua UL et al

in Forty-Third International Conference on Information Systems (2022, October)

Society’s accelerating digital transformation during the COVID-19 pandemic highlighted clearly that the Internet lacks a secure, efficient, and privacy-oriented model for identity. Self-sovereign identity ... [more ▼]

Society’s accelerating digital transformation during the COVID-19 pandemic highlighted clearly that the Internet lacks a secure, efficient, and privacy-oriented model for identity. Self-sovereign identity (SSI) aims to address core weaknesses of siloed and federated approaches to digital identity management from both users’ and service providers’ perspectives. SSI emerged as a niche concept in libertarian communities, and was initially strongly associated with blockchain technology. Later, when businesses and governments began to invest, it quickly evolved towards a mainstream concept. To investigate this evolution and its effects on SSI, we conduct design science research rooted in the theory of technological transition pathways. Our study identifies nine core design principles of SSI as deployed in relevant applications, and discusses associated competing political and socio-technical forces in this space. Our results shed light on SSI’s key characteristics, its development pathway, and tensions in the transition between regimes of digital identity management [less ▲]

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See detailLa consommation de Cannabis chez les jeunes d’âge scolaire (12-18 ans) au Luxembourg - Résultats de l'enquête HBSC de 2018
Catunda, Carolina UL; Heinz, Andreas UL; Geraets, Anouk UL

Report (2022)

Le cannabis est considéré comme la substance illicite la plus fréquemment consommée dans le monde. Sa consommation est jugée particulièrement dangereuse si elle est fréquente, fortement dosée et commence ... [more ▼]

Le cannabis est considéré comme la substance illicite la plus fréquemment consommée dans le monde. Sa consommation est jugée particulièrement dangereuse si elle est fréquente, fortement dosée et commence à l'adolescence. En raison de ses effets nocifs sur la santé et la société, ce rapport a pour objectif d’examiner le nombre de jeunes qui consomment du cannabis au Luxembourg, ainsi que les facteurs sociodémographiques, de risque et de protection associés à cette consommation, afin d'illustrer les possibilités d'interventions promotion de la santé et de prévention de comportement addictifs. Les données présentées proviennent de l'enquête Health Behaviour in School-aged Children - HBSC de 2018. L’analyse porte sur les données de 6 880 jeunes de l‘enseignement secondaire âgés de 12 à 18 ans. Pour répondre à l’objectif, les jeunes ont été répartis en 3 groupes : 1) les jeunes qui n'ont jamais consommé du cannabis ; 2) les jeunes qui ont consommé du cannabis dans leur vie, mais pas au cours des 30 derniers jours (consommation passée) et ; 3) les jeunes qui ont consommé du cannabis au cours des 30 derniers jours (consommation actuelle). Les analyses descriptives montrent que parmi les participants, 82 % n'ont jamais consommé du cannabis, 9 % en ont consommé dans le passé et 9 % en consomment actuellement. À l’aide des analyses de régression logistique multinomiales, le lien entre la consommation de cannabis et une série de variables sociodémographiques, des comportements à risque, le soutien social, le milieu scolaire et la santé et le bien-être a été analysé, afin d'explorer les facteurs sociodémographiques, de risque et de protections associés à la consommation de cannabis. Les seuls facteurs qui restent significatifs pour la consommation de cannabis sont l'âge, le genre, la situation familiale, la consommation de tabac, la consommation d'alcool, la participation à des bagarres, la perception du soutien de la part des parents et des enseignants par les élèves. Toutefois, l'âge et la consommation actuelle de tabac sont les facteurs les plus importants. Ainsi, en ce qui concerne les facteurs sociodémographiques, les garçons, les adolescents les plus âgés et ceux qui ne vivent pas avec leurs deux parents sont plus enclins à faire partie des groupes qui ont consommé du cannabis. L’augmentation des comportements à risque (fréquence plus élevée de consommation de tabac, d'alcool et de participation à des bagarres) se traduit par une plus grande probabilité de consommation de cannabis. De plus, les jeunes qui ont un comportement à risque ont tendance à opter pour d'autres comportements à risque. En revanche, le soutien perçu de la famille et le soutien perçu des enseignants sont des facteurs protégeant de la consommation de cannabis. Ainsi, les élèves qui se sentent soutenus par leurs parents et leurs enseignants sont moins enclins à consommer du cannabis. Il est donc pertinent d'adapter les méthodes de prévention de la consommation de cannabis en fonction de l'âge et du genre, et d’axer les approches de prévention sur ceux qui considèrent sa consommation comme l’un des éléments d'un comportement à risque global plutôt que celles ciblant uniquement cette substance. En effet, les modèles de prévention qui visent à promouvoir un comportement global plus soucieux de la santé semblent être plus efficaces. [less ▲]

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See detailOptimal coalition splitting with heterogenous strategies
Boucekkine, Raouf; Camcho, Carmen; Ruan, Weihua et al

E-print/Working paper (2022)

We consider a group of players initially members of a coalition managing cooperatively a public bad, in this case, the stock of pollution. Countries are technologically heterogeneous but the pollution ... [more ▼]

We consider a group of players initially members of a coalition managing cooperatively a public bad, in this case, the stock of pollution. Countries are technologically heterogeneous but the pollution damage is uniform. We essentially attempt to characterize the conditions under which a country may eventually split and when it splits within an infinite horizon multi-stage differential game. In contrast to the existing literature, we do not assume that after splitting, the splitting player and the remaining coalition will adopt Markovian strategies. Instead, we assume that the latter will remain committed to the collective control of pollution and play open-loop, while the splitting player plays Markovian. Within a full linear-quadratic model, we characterize the optimal strategies. We later compare with the outcomes of the case where the splitting player and the remaining coalition play both Markovian. We highlight several interesting results in terms of the implications for long- term pollution levels and the duration of coalitions with heterogeneous strategies. [less ▲]

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See detailAlgorithmic Trading in Experimental Markets with Human Traders: A Literature Survey
Neugebauer, Tibor UL; Nekrasova, Elizaveta UL; Bao, Te et al

in Fullbrunn, Sascha (Ed.) Handbook of Experimental Finance (2022)

This chapter surveys the nascent experimental research on the interaction between human and algorithmic (bot) traders in experimental markets. We first discuss studies in which algorithmic traders are in ... [more ▼]

This chapter surveys the nascent experimental research on the interaction between human and algorithmic (bot) traders in experimental markets. We first discuss studies in which algorithmic traders are in the researcher’s hands. Specifically, the researcher assigns computer agents as traders in the market. We then followed it up by discussing studies in which the researcher allows human traders to decide whether to employ algorithms for trading or to trade by themselves. The paper introduces the types and performances of algorithmic traders that interact with human subjects in the laboratory, including zero-intelligent traders, arbitragers, fundamentalists, adaptive algorithms, and manipulators. We find that whether algorithm traders earn more profit than human traders crucially depends on the asset’s fundamental value process and the market environment. The potential impact of interactions with algorithms on the investor’s psychology is also discussed. [less ▲]

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See detailIntroduction (Enforcement Challenges in Multilevel Regulatory Systems)
Zinonos, Panagiotis UL; Ligeti, Katalin UL; Brodersen, Kei Hannah

in Ligeti, Katalin; Brodersen, Kei Hannah (Eds.) Studies on Enforcement in Multilevel Regulatory Systems (2022)

Detailed reference viewed: 13 (1 UL)