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See detailMaladies mentales et société (XIXe – XXIe siècles)
Henckes, Nicolas; Majerus, Benoît UL

Book published by La Découverte (2022)

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See detailMake-or-buy decisions for industrial additive manufacturing
Friedrich, Anne UL; Lange, Anne UL; Elbert, Ralf

in Journal of Business Logistics (2022)

Much of the potential of industrial additive manufacturing (AM) is said to lie in the digital specification of components that can be transmitted seamlessly and unambiguously to partners fostering ... [more ▼]

Much of the potential of industrial additive manufacturing (AM) is said to lie in the digital specification of components that can be transmitted seamlessly and unambiguously to partners fostering flexible outsourcing. In industry, we observe nuanced AM supply chain governance structures that result from make-or-buy decisions, with a tendency to implement AM in-house. Thus, there is a discrepancy between what is discussed in the literature and implemented in practice. We apply a multiple-case study approach to investigate why and how AM impacts the make-or-buy decision of manufacturing firms. We identify four decision profiles demonstrating the spectrum of specific governance structures and develop a framework to explain the underlying rationales. We find strong arguments for in-house AM including firms’ perceived need to protect their digitally encapsulated intellectual property, reevaluation of their core competencies, commitment to internal learning, and senior management's enthusiasm for AM. By using transaction cost economics and the resource-based view, we contribute to the understanding of how arguments of these general theories are modified by the digital and emerging traits of AM. We reveal contradicting guidance in the theories’ argumentation for the case of AM and provide managers a clear perspective on alternative strategies for their AM implementation process. © 2022 The Authors. Journal of Business Logistics published by Wiley Periodicals LLC. [less ▲]

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See detailInstitutional Characteristics of Education Systems and Inequalities: Introduction II
Gross, Christiane; Zapfe, Laura; Hadjar, Andreas UL

in International Journal of Comparative Sociology (2022), early online

This is the second special issue of the International Journal of Comparative Sociology on the role of education systems as institutional settings on the reproduction of inequalities. The first was ... [more ▼]

This is the second special issue of the International Journal of Comparative Sociology on the role of education systems as institutional settings on the reproduction of inequalities. The first was published in January 2021 and included papers that explored the role of shadow education and country characteristics during early childhood on educational inequalities. This special issue includes three papers that focus on stratification of the education system as a key driver of educational inequalities, cumulative (dis)advantage in the access to higher education, and student experiences in national educational systems. While we already elaborated on the research program, conceptual framework, and methodological challenges in the first introduction, we will deal with the current state-of-research in this second introduction. [less ▲]

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See detailA RNN-Based Hyper-Heuristic for Combinatorial Problems
Kieffer, Emmanuel UL; Duflo, Gabriel UL; Danoy, Grégoire UL et al

in A RNN-Based Hyper-Heuristic for Combinatorial Problems (2022)

Designing efficient heuristics is a laborious and tedious task that generally requires a full understanding and knowledge of a given optimization problem. Hyper-heuristics have been mainly introduced to ... [more ▼]

Designing efficient heuristics is a laborious and tedious task that generally requires a full understanding and knowledge of a given optimization problem. Hyper-heuristics have been mainly introduced to tackle this issue and are mostly relying on Genetic Programming and its variants. Many attempts in the literature have shown that an automatic training mechanism for heuristic learning is possible and can challenge human-based heuristics in terms of gap to optimality. In this work, we introduce a novel approach based on a recent work on Deep Symbolic Regression. We demonstrate that scoring functions can be trained using Recurrent Neural Networks to tackle a well-know combinatorial problem, i.e., the Multi-dimensional Knapsack. Experiments have been conducted on instances from the OR-Library and results show that the proposed modus operandi is an alternative and promising approach to human- based heuristics and classical heuristic generation approaches. [less ▲]

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See detailParkin Deficiency Impairs Mitochondrial DNA Dynamics and Propagates Inflammation.
Wasner, Kobi; Smajic, Semra UL; Ghelfi, Jenny UL et al

in Movement disorders : official journal of the Movement Disorder Society (2022)

BACKGROUND: Mutations in the E3 ubiquitin ligase parkin cause autosomal recessive Parkinson's disease (PD). Together with PTEN-induced kinase 1 (PINK1), parkin regulates the clearance of dysfunctional ... [more ▼]

BACKGROUND: Mutations in the E3 ubiquitin ligase parkin cause autosomal recessive Parkinson's disease (PD). Together with PTEN-induced kinase 1 (PINK1), parkin regulates the clearance of dysfunctional mitochondria. New mitochondria are generated through an interplay of nuclear- and mitochondrial-encoded proteins, and recent studies suggest that parkin influences this process at both levels. In addition, parkin was shown to prevent mitochondrial membrane permeability, impeding mitochondrial DNA (mtDNA) escape and subsequent neuroinflammation. However, parkin's regulatory roles independent of mitophagy are not well described in patient-derived neurons. OBJECTIVES: We sought to investigate parkin's role in preventing neuronal mtDNA dyshomeostasis, release, and glial activation at the endogenous level. METHODS: We generated induced pluripotent stem cell (iPSC)-derived midbrain neurons from PD patients with parkin (PRKN) mutations and healthy controls. Live-cell imaging, proteomic, mtDNA integrity, and gene expression analyses were employed to investigate mitochondrial biogenesis and genome maintenance. To assess neuroinflammation, we performed single-nuclei RNA sequencing in postmortem tissue and quantified interleukin expression in mtDNA/lipopolysaccharides (LPS)-treated iPSC-derived neuron-microglia co-cultures. RESULTS: Neurons from patients with PRKN mutations revealed deficits in the mitochondrial biogenesis pathway, resulting in mtDNA dyshomeostasis. Moreover, the energy sensor sirtuin 1, which controls mitochondrial biogenesis and clearance, was downregulated in parkin-deficient cells. Linking mtDNA disintegration to neuroinflammation, in postmortem midbrain with PRKN mutations, we confirmed mtDNA dyshomeostasis and detected an upregulation of microglia overexpressing proinflammatory cytokines. Finally, parkin-deficient neuron-microglia co-cultures elicited an enhanced immune response when exposed to mtDNA/LPS. CONCLUSIONS: Our findings suggest that parkin coregulates mitophagy, mitochondrial biogenesis, and mtDNA maintenance pathways, thereby protecting midbrain neurons from neuroinflammation and degeneration. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [less ▲]

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See detailLa région Minett en tant que palimpseste
Derian, Maxime UL; Tschacher, Werner UL

Article for general public (2022)

Dans certaines parties du Minett, le paysage peut être considéré comme une sorte de palimpseste. Pour les historiens et les archéologues, un palimpseste est un support d’écriture, par exemple un parchemin ... [more ▼]

Dans certaines parties du Minett, le paysage peut être considéré comme une sorte de palimpseste. Pour les historiens et les archéologues, un palimpseste est un support d’écriture, par exemple un parchemin, qui est utilisé plusieurs fois après effacement du texte précédent. Au fil des siècles, le paysage du Minett a en effet beaucoup changé au gré des interventions humaines. Le sol raconte de nombreuses histoires qui se chevauchent et s’entremêlent. Certains éléments ont été entièrement effacés, tandis que d’autres traces du passé subsistent. [less ▲]

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See detailLa loyauté dans l'interprétation des accords internationaux
Neframi, Eleftheria UL

in Delile, Jean Felix (Ed.) La loyauté dans l'action extérieure de l'Union européenne (2022)

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See detailThe Minett as Palimpsest
Derian, Maxime UL; Tschacher, Werner UL

Article for general public (2022)

The landscape in some parts of the Minett can be considered as a kind of palimpsest. For historians and archaeologists, a palimpsest is a writing medium, for example a parchment or a manuscript, that is ... [more ▼]

The landscape in some parts of the Minett can be considered as a kind of palimpsest. For historians and archaeologists, a palimpsest is a writing medium, for example a parchment or a manuscript, that is used several times by erasing the previous writing. The landscape of the Minett has also changed greatly over the centuries as a result of human intervention. The soil can tell many overlapping and entangled stories. Some things have been completely erased, while other traces of past times have been left. [less ▲]

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See detailFrom Smart to Secure Contracts: Automated Security Assessment and Improvement of Ethereum Smart Contracts
Ferreira Torres, Christof UL

Doctoral thesis (2022)

Modern blockchains, such as Ethereum, gained tremendously in popularity over the past few years. What partially enables this large increase are so-called smart contracts. These are programs that are ... [more ▼]

Modern blockchains, such as Ethereum, gained tremendously in popularity over the past few years. What partially enables this large increase are so-called smart contracts. These are programs that are deployed and executed across the blockchain. However, just like traditional programs, smart contracts are subject to programming mistakes. Although, unlike traditional programs their code is publicly available and immutable. Hence, as smart contracts become more popular and carry more value, they become a more interesting target for attackers. In the past few years, several smart contracts have been exploited, resulting in assets worth millions of dollars being stolen. In this dissertation, we explore the security of smart contracts from three different perspectives: vulnerabilities, attacks, and defenses, and demonstrate that, as so often, "smart" does not imply "secure". In the first part of the dissertation, we study the automated detection of vulnerabilities in smart contracts, without requiring prior access to source code. We start by building a symbolic execution framework for detecting integer bugs that leverages taint analysis to reduce false positives. However, as symbolic execution is notorious to produce false positives, we explore hybrid fuzzing as an alternative. As a result, we propose a hybrid fuzzer for smart contracts that combines symbolic execution with fuzz testing and leverages data dependencies across state variables to efficiently generate transaction sequences. Our approach is capable of detecting more vulnerabilities with less false positives. In the second part of the dissertation, we explore various ways to mount attacks against smart contracts. We start by proposing a framework to detect and quantify classical smart contract attacks (e.g., reentrancy, integer overflows, etc.) on past transactions by combining logic-driven and graph-driven analysis. Afterwards, we study the effectiveness of a new type of fraud known as honeypots, by scanning the entire blockchain for different types of honeypots using symbolic execution. Next, we present a methodology to measure the prevalence of so-called frontrunning attacks, which follow from the rise of decentralized finance and the sharp increase of users trading on decentralized exchanges. Our results show that attackers are making a fortune by manipulating the order of transactions. In the third and final part of the dissertation, we discuss several defense mechanisms for smart contracts. We first propose a solution that developers can use to automatically patch vulnerable smart contract bytecode using context-sensitive patches that dynamically adapt to the bytecode that is being patched. However, this does not solve the issue of already deployed smart contracts. To that end, we present a second solution that enables security experts to write attack patterns that are triggered whenever malicious control and data flows are detected. Once a transaction is detected to be malicious, all state changes are rolled back and the attack is thereby prevented. These attack patterns are written using a domain-specific language and are managed via a smart contract. The latter enables decentralization, guarantees the distribution of security updates, and warrants transparency. [less ▲]

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See detailStatus and Enforceability of EU International Agreements within the Domestic Legal Systems of the Member States: Kupferberg
Neframi, Eleftheria UL

in Wessel, Ramses; Butler, Graham (Eds.) EU External Relations Law: The Cases in Context (2022)

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See detailGeometrie der römischen Mosaiken
Perucca, Antonella UL

Scientific Conference (2022)

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See detailLes centrales nucléaires dans la littérature du Luxembourg
Thiltges, Sébastian UL

in Les Cahiers luxembourgeois (2022), 1

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See detailSmall-angle neutron scattering by spatially inhomogeneous ferromagnets with a nonzero average uniaxial anisotropy
Zaporozhets, V. D.; Oba, Y.; Michels, Andreas UL et al

in Journal of Applied Crystallography (2022), 55

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See detailGeodetic climate research in the Austrian Alps
Ullrich, Christian; Francis, Olivier UL; Tabibi, Sajad UL et al

Scientific Conference (2022)

The Federal Office of Metrology and Surveying (BEV) in Austria is responsible for the geodetic reference system like gravity and height reference frame. Some of these gravity reference stations are ... [more ▼]

The Federal Office of Metrology and Surveying (BEV) in Austria is responsible for the geodetic reference system like gravity and height reference frame. Some of these gravity reference stations are monitored regularly by different geodetic terrestrial techniques. The gravity data on some stations show variations and/or changes in gravity. In this presentation, the alpine geodetic reference stations Obergurgl and Franz-Josefs- Höhe in the Austrian eastern Alps will be presented. Both stations are investigated with different geodetic terrestrial techniques in a cooperation of the University of Luxemburg with BEV. Global warming and associated climate change during the last century and recent decades are among the main reasons for glacier retreat in the Alps. Absolute gravity measurements have been regularly performed in the Austrian Eastern Alps since 1987 in the Ötztal Valley at Obergurgl. In addition, absolute gravity has been regularly observed at Obergurgl from 1987 to 2009 with the absolute gravimeter JILAg6. From 2010, the absolute gravity measurements were continued with the highest accurate absolute gravimeters FG5 from BEV and FG5x from University of Luxemburg. The newest gravity data show again a small increase of gravity. Additionally, a permanent GNSS station was established in 2019 to record information about the assumed vertical uplift at this station. A second alpine research station was established near the Pasterze Glacier at Großglockner Mountain in 2019. The Pasterze Glacier is one of the largest glaciers in the eastern Alps and is in the vicinity of the highest mountain of Austria, the Großglockner. The station is monitored by repeated absolute gravity measurements and is equipped with a permanent GNSS station. In addition, precise leveling measurements were also tied to this station. In this contribution, initial results of the geodetic research like the gravity results, precise leveling and GNSS measurements will be presented. In the future, gravity data will be quantitively compared to ice mass balance information derived from glacier inventories. A Geodetic Global Navigation Satellite System reflectometry (GNSS-R) antenna will also be installed to study glacier-ice change. A third station at an altitude of 3300 m is planned and will be checked for operating absolute gravity measurements there. The geodynamical processes like vertical uplift and postglacial deformation will be investigated together with glacier retreat on these stations. [less ▲]

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See detailHow Efficient are Replay Attacks against Vote Privacy? A Formal Quantitative Analysis
Mestel, David UL; Mueller, Johannes UL; Reisert, Pascal

in 35th IEEE Computer Security Foundations Symposium (2022)

Replay attacks are among the most well-known attacks against vote privacy. Many e-voting systems have been proven vulnerable to replay attacks, including systems like Helios that are used in real ... [more ▼]

Replay attacks are among the most well-known attacks against vote privacy. Many e-voting systems have been proven vulnerable to replay attacks, including systems like Helios that are used in real practical elections. Despite their popularity, it is commonly believed that replay attacks are inefficient but the actual threat that they pose to vote privacy has never been studied formally. Therefore, in this paper, we precisely analyze for the first time how efficient replay attacks really are. We study this question from commonly used and complementary perspectives on vote privacy, showing as an independent contribution that a simple extension of a popular game-based privacy definition corresponds to a strong entropy-based notion. Our results demonstrate that replay attacks can be devastating for a voter's privacy even when an adversary's resources are very limited. We illustrate our formal findings by applying them to a number of real-world elections, showing that a modest number of replays can result in significant privacy loss. Overall, our work reveals that, contrary to a common belief, replay attacks can be very efficient and must therefore be considered a serious threat. [less ▲]

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See detailDeep Learning-Based Device-Free Localization in Wireless Sensor Networks
Abdullah, Osamah; Al-Hraishawi, Hayder UL; Chatzinotas, Symeon UL

Scientific Conference (2022)

Location-based services (LBS) are witnessing a rise in popularity owing to their key features of delivering powerful and personalized digital experiences. The recent developments in wireless sensing ... [more ▼]

Location-based services (LBS) are witnessing a rise in popularity owing to their key features of delivering powerful and personalized digital experiences. The recent developments in wireless sensing techniques make the realization of device-free localization (DFL) feasible in wireless sensor networks. The DFL is an emerging technology that utilizes radio signal information for detecting and positioning a passive target while the target is not equipped with a wireless device. However, determining the characteristics of the massive raw signals and extracting meaningful discriminative features relevant to the localization are highly intricate tasks. Thus, deep learning (DL) techniques can be utilized to address the DFL problem due to their unprecedented performance gains in many practical problems. In this direction, we propose a DFL framework consists of multiple convolutional neural network (CNN) layers along with autoencoders based on the restricted Boltzmann machines (RBM) to construct a convolutional deep belief network (CDBN) for features recognition and extracting. Each layer has stochastic pooling to sample down the feature map and reduced the dimensions of the required data for precise localization. The proposed framework is validated using real experimental dataset. The results show that our algorithm can achieve a high accuracy of 98\% with reduced data dimensions and low signal-to-noise ratios (SNRs). [less ▲]

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See detailEnergy Harvesting from Jamming Attacks in Multi-User Massive MIMO Networks
Al-Hraishawi, Hayder UL; Abdullah, Osamah; Chatzinotas, Symeon UL et al

in IEEE Transactions on Green Communications and Networking (2022)

5G communication systems enable new functions and major performance improvements but at the cost of tougher energy requirements on mobile devices. One of the effective ways to address this issue along ... [more ▼]

5G communication systems enable new functions and major performance improvements but at the cost of tougher energy requirements on mobile devices. One of the effective ways to address this issue along with alleviating the environmental effects associated with the inevitable large increase in energy usage is the energy-neutral systems, which operate with the energy harvested from radio-frequency (RF) transmissions. In this direction, this paper investigates the notion of harvesting the ambient RF signals from an unusual source. Specifically, the performance of an RF energy harvesting scheme for multi-user massive multiple-input multiple-output (MIMO) is investigated in the presence of multiple active jammers. The key idea is to exploit the jamming transmissions as an energy source to be harvested at the legitimate users. To this end, the achievable uplink sum rate expressions are derived in closed-form for two different antenna configurations. Two optimal time-switching schemes are also proposed based on maximum sum rate and user-fairness criteria. Besides, the essential trade-off between the harvested energy and achievable sum rate are quantified in closed-form. Our analysis reveals that the massive MIMO systems can exploit the surrounding RF signals of the jamming attacks for boosting the amount of harvested energy at the served users. Finally, numerical results illustrate the effectiveness of the derived closed-form expressions through simulations. [less ▲]

Detailed reference viewed: 83 (9 UL)