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See detailInside the Trading Zone: Thinkering in a Digital History Lab
Fickers, Andreas UL; van der Heijden, Tim UL

in Digital Humanities Quarterly (2020), 14(3),

The goal of this article is to critically reflect on the practical and epistemological challenges of doing historical research in the digital age. The analysis is based on a case study of the Doctoral ... [more ▼]

The goal of this article is to critically reflect on the practical and epistemological challenges of doing historical research in the digital age. The analysis is based on a case study of the Doctoral Training Unit (DTU) “Digital History and Hermeneutics”, an interdisciplinary research and training programme that was established at the Luxembourg Centre for Contemporary and Digital History (C²DH) of the University of Luxembourg. The DTU is designed as interdisciplinary trading zone that applies the method of “thinkering” – the tinkering with technology combined with the critical reflection on the practice of doing digital history. Based on this case study, the article addresses the question of how to constitute an interdisciplinary trading zone in practice and how to situate this trading zone in physical working environments, like a Digital History Lab and shared office space. [less ▲]

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See detailPre and post-treatments to improve weldability and mechanical properties of Aluminum-Polyamide laser welded specimens
Amne Elahi, Mahdi UL; Koch, Marcus; Heck, Mike et al

in Procedia CIRP (2020), 94

The laser polishing surface treatment is a prerequisite for enhanced weldability that is enabled by superior adhesion between the weldments. The paper describes the laser polishing process of the aluminum ... [more ▼]

The laser polishing surface treatment is a prerequisite for enhanced weldability that is enabled by superior adhesion between the weldments. The paper describes the laser polishing process of the aluminum surface to develop a relatively thick and porous artificial aluminum oxide layer. Microscopic observation shows the laser polishing process significantly improves the adhesion of molten polyamide to the aluminum surface. Besides, the shear load of the pretreated joints is much higher than that of as-received ones. However, for the majority of the welded samples, the failure happens at the polyamide near the interface of aluminum/polyamide due to the thermal effect and structural changes of polyamide during the welding process. By applying the post-treatment of the welded specimens with different cycles, the mentioned failure mechanism is not observed anymore. Therefore, the mechanical properties of the joint will be improved and reach to the limits of the base materials. [less ▲]

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See detailDissipation-Time Uncertainty Relation
Falasco, Gianmaria UL; Esposito, Massimiliano UL

in Physical Review Letters (2020), 125(12), 120604

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See detailGround‐to‐GEO optical feeder links for very high throughput satellite networks: Accent on diversity techniques
Mengali, Alberto; Kourogiorgas, Charilaos; Lyras, Nikolaos et al

in International Journal of Satellite Communications and Networking (2020)

This paper studies the use of optical feeder links in very high throughput satellites (VHTS) networks with emphasis on gateway diversity techniques to mitigate the inherent propagation losses in optical ... [more ▼]

This paper studies the use of optical feeder links in very high throughput satellites (VHTS) networks with emphasis on gateway diversity techniques to mitigate the inherent propagation losses in optical frequencies. Focusing on a GEO scenario, the paper considers a system‐wide approach investigating various challenges of optical feeder links. These include transmission schemes amenable for transparent on‐board processing, optical channel models taking into account blockage by clouds and fading caused by atmospheric turbulence in addition to complexity of on‐board and on‐ground processing. The channel models are then used to dimension the ground segment towards ensuring a given availability percentage (e.g., 99.9%). The channel model and payload complexity further influence the choice of link layer techniques used for counteracting fading due to atmospheric turbulence in the absence of blockage. An elaborate end‐to‐end simulator incorporating the proposed channel models capturing the nuances of various processing blocks like optical‐electrical conversion is developed. The system performance results provide interesting insights and a framework for assessing the feasibility and advantages of optical feeder links in VHTS systems. [less ▲]

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See detailKritische oder angewandte Geographie – oder beides? Ein Kommentar
Hesse, Markus UL

in Standort (2020), 44(4), 275-278

The aim of this commentary is threefold. First, it interrogates the specific definition and situatedness of “critical” and “applied” geography; second, it discusses the assumption that there is a ... [more ▼]

The aim of this commentary is threefold. First, it interrogates the specific definition and situatedness of “critical” and “applied” geography; second, it discusses the assumption that there is a disconnect between science and social movements made in the context of critical discourses. Third, this leads to reflection upon what the interface between science and practice in geography is, or what it could or should be like today. [less ▲]

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See detailCoverage Probability and Ergodic Capacity of Intelligent Reflecting Surface-Enhanced Communication Systems
Trinh, van Chien UL; Tu, Lam Thanh; Chatzinotas, Symeon UL et al

in IEEE Communications Letters (2020)

This paper studies the performance of a single-input single-output (SISO) system enhanced by the assistance of an intelligent reflecting surface (IRS), which is equipped with a finite number of elements ... [more ▼]

This paper studies the performance of a single-input single-output (SISO) system enhanced by the assistance of an intelligent reflecting surface (IRS), which is equipped with a finite number of elements under Rayleigh fading channels. From the instantaneous channel capacity, we compute a closed-form expression of the coverage probability as a function of statistical channel information only. A scaling law of the coverage probability and the number of phase shifts is further obtained. The ergodic capacity is derived, then a simple upper bound to simplify matters of utilizing the symbolic functions and can be applied for a long period of time. Numerical results manifest the tightness and effectiveness of our closed-form expressions compared with Monte-Carlo simulations. [less ▲]

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See detailTesting market regulations in experimental asset markets –The case of margin purchases
Neugebauer, Tibor UL; Füllbrunn, Sascha

in Journal of Economic Behavior and Organization (2020)

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See detailPermissioned Blockchain Frameworks in the Industry: A Comparison
Polge, Julien UL; Robert, Jérémy UL; Le Traon, Yves UL

in ICT Express (2020)

Permissioned and private blockchain platforms are increasingly used in today’s industry. This paper provides a comprehensive and comparative study of the 5 major frameworks (Fabric, Ethereum, Quorum ... [more ▼]

Permissioned and private blockchain platforms are increasingly used in today’s industry. This paper provides a comprehensive and comparative study of the 5 major frameworks (Fabric, Ethereum, Quorum, MultiChain and R3 Corda) with regard to the community activities, performance, scalability, privacy and adoption criteria. Based on a literature review, this study shows that even if Fabric is promising, the final selection of a framework for a specific case-study is always a trade-off. Finally, lessons learnt are given for industrial practitioners and researchers. [less ▲]

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See detailMoving beyond language(s): a case study on a newcomer’s translanguaging practices
Degano, Sarah UL; Kirsch, Claudine UL

in European Journal of Applied Linguistics (2020)

Numerous scholars have investigated translanguaging in students with a migration background by examining the deployment of their linguistic repertoire. By contrast, few studies have adopted a social ... [more ▼]

Numerous scholars have investigated translanguaging in students with a migration background by examining the deployment of their linguistic repertoire. By contrast, few studies have adopted a social semiotic perspective on translanguaging. Similarly, studies on newcomers in this field are scarce. Newcomers, especially those to the trilingual education system in Luxembourg, face significant language challenges. The present paper explores the ways in which Portuguese-speaking Harry combined the resources of his semiotic repertoire in science and French lessons in Year 4, and discusses different combinations of resources. Findings based on field notes and video-recordings of classroom activities show that the eleven-year-old engaged in learning by activating his prior knowledge and deploying his semiotic repertoire in resourceful ways. He mobilised features of five languages, coordinated linguistic, paralinguistic and extralinguistic resources, and aligned his resources to those of his peers. Furthermore, he reproduced the semiotic combinations of peers as well as the translanguaging practices in class. We show that a newcomer orchestrates his semiotic resources in complex ways to communicate, make meaning and engage in learning processes. Further research into the deployment of the semiotic repertoire at school is needed. [less ▲]

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See detailBusiness Models and Profitability of Energy Storage
Baumgarte, Felix; Glenk, Gunther; Rieger, Alexander UL

in iScience (2020), 23(10),

Rapid growth of intermittent renewable power generation makes the identification of investment opportunities in energy storage and the establishment of their profitability indispensable. Here we first ... [more ▼]

Rapid growth of intermittent renewable power generation makes the identification of investment opportunities in energy storage and the establishment of their profitability indispensable. Here we first present a conceptual framework to characterize business models of energy storage and systematically differentiate investment opportunities. We then use the framework to examine which storage technologies can perform the identified business models and review the recent literature regarding the profitability of individual combinations of business models and technologies. Our analysis shows that a set of commercially available technologies can serve all identified business models. We also find that certain combinations appear to have approached a tipping point toward profitability. Yet, this conclusion only holds for combinations examined most recently or stacking several business models. Many technologically feasible combinations have been neglected, indicating a need for further research to provide a detailed and conclusive understanding about the profitability of energy storage. [less ▲]

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See detailToward Understanding Complex Spin Textures in Nanoparticles by Magnetic Neutron Scattering
G. Vivas, Laura; Yanes, Rocio; Berkov, Dmitry et al

in Physical Review Letters (2020), 125

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See detailNon-Coding RNAs in the Brain-Heart Axis: The Case of Parkinson’s Disease
Acharya, Shubhra; Salgado-Somoza, Antonio; Stefanizzi, Francesca Maria et al

in International Journal of Molecular Sciences (2020), 21(18), 6513

Parkinson’s disease (PD) is a complex and heterogeneous disorder involving multiple genetic and environmental influences. Although a wide range of PD risk factors and clinical markers for the symptomatic ... [more ▼]

Parkinson’s disease (PD) is a complex and heterogeneous disorder involving multiple genetic and environmental influences. Although a wide range of PD risk factors and clinical markers for the symptomatic motor stage of the disease have been identified, there are still no reliable biomarkers available for the early pre-motor phase of PD and for predicting disease progression. High-throughput RNA-based biomarker profiling and modeling may provide a means to exploit the joint information content from a multitude of markers to derive diagnostic and prognostic signatures. In the field of PD biomarker research, currently, no clinically validated RNA-based biomarker models are available, but previous studies reported several significantly disease-associated changes in RNA abundances and activities in multiple human tissues and body fluids. Here, we review the current knowledge of the regulation and function of non-coding RNAs in PD, focusing on microRNAs, long non-coding RNAs, and circular RNAs. Since there is growing evidence for functional interactions between the heart and the brain, we discuss the benefits of studying the role of non-coding RNAs in organ interactions when deciphering the complex regulatory networks involved in PD progression. We finally review important concepts of harmonization and curation of high throughput datasets, and we discuss the potential of systems biomedicine to derive and evaluate RNA biomarker signatures from high-throughput expression data. [less ▲]

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See detailPareto-Optimal Pilot Design for Cellular Massive MIMO Systems
Le, Anh Tuan; Trinh, van Chien UL; Reza Nakhai, Mohammad et al

in IEEE Transactions on Vehicular Technology (2020)

We introduce a non-orthogonal pilot design scheme that simultaneously minimizes two contradicting targets of channel estimation errors of all base stations (BSs) and the total pilot power consumption of ... [more ▼]

We introduce a non-orthogonal pilot design scheme that simultaneously minimizes two contradicting targets of channel estimation errors of all base stations (BSs) and the total pilot power consumption of all users in a multi-cell massive MIMO system, subject to the transmit power constraints of the users in the network. We formulate a multi-objective optimization problem (MOP) with two objective functions capturing the contradicting targets and find the Pareto optimal solutions for the pilot signals. Using weighted-sum-scalarization technique, we first convert the MOP to an equivalent single-objective optimization problem (SOP), which is not convex. Assuming that each BS is provided with the most recent knowledge of the pilot signals of the other BSs, we then decompose the SOP into a set of distributed non-convex optimization problems to be solved at individual BSs. Finally, we introduce an alternating optimization approach to cast each one of the resulting distributed optimization problems into a convex linear matrix inequality (LMI) form. We provide a mathematical proof for the convergence of the proposed alternating approach and a complexity analysis for the LMI optimization problem. Simulation results confirm that the proposed approach significantly reduces pilot power, whilst maintaining the same level of channel estimation error as in [1]. [less ▲]

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See detailAb-initio calculation of muon spin polarization function to study lithium-ion diffusion in LiTi2O4 battery material
Suprayoga, E.; Rifai, A.; Subhan, A. et al

in AIP Conference Proceedings (2020), 2256(1), 030015

We report the study of lithium-ion diffusion in LiTi2O4 battery material by the analysis of muon spin polarization function at the muon site by DFT calculation. The important parameters which explain the ... [more ▼]

We report the study of lithium-ion diffusion in LiTi2O4 battery material by the analysis of muon spin polarization function at the muon site by DFT calculation. The important parameters which explain the lithium-ion diffusion will be derived from the function, including the field fluctuation rate and the local field distribution. The calculated results are shown in good agreement with the previously measured field distribution and the field fluctuation rate in LiTi2O4 at the ground state temperature. This method, therefore, may apply to the study of other battery materials. [less ▲]

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See detailSchmidentity and Informativity
Fraissler, Hannes UL

in Synthese (2020)

Although Kripke’s œuvre has had a major impact on analytic philosophy and nearly every aspect of his studies has been thoroughly examined, this does not hold for his schmidentity argument, which, so far ... [more ▼]

Although Kripke’s œuvre has had a major impact on analytic philosophy and nearly every aspect of his studies has been thoroughly examined, this does not hold for his schmidentity argument, which, so far, has been widely neglected. To the extent to which it has been treated at all, it has been for the most part radically misunderstood. I hold that this argument, in its correctly reconstructed form, has general relevance for a treatment of Frege’s Puzzle and points towards a fundamental methodological restriction for philosophy of language and especially for semantics, as far as informativity and the general topic of cognitive significance are concerned. To show this, I will (Sect. 1) briefly set out the context of the schmidentity argument and, in Sects. 2 and 4, sketch a reconstruction thereof, including (Sect. 3) some criticisms of the argument, and (Sect. 6) an excursion about Kit Fine’s semantic relationism, which stands in stark contrast to this paper’s central claim. Moreover, I will (Sect. 5) draw a genuinely new and probably quite unexpected conclusion from all the above (amounting to the position that Frege’s Puzzle cannot be solved in terms of semantics), to finally (Sect. 7) give a glimpse at a bigger picture of where this conclusion should lead our thinking about a theoretical treatment of informativity and a linguistic expression’s cognitive value. [less ▲]

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See detailThermoelectric properties of two-dimensional hydrogenated borophene: A first-principles study
Hanna, M.Y.; Hasdeo, Eddwi Hesky UL; Suprayoga, E. et al

in AIP Conference Proceedings (2020), 2256(1), 030017

We theoretically study electronic and thermoelectric properties of two-dimensional hydrogenated borophene (”boro-phane”). We show that, according to the first-principles calculation, hydrogenated ... [more ▼]

We theoretically study electronic and thermoelectric properties of two-dimensional hydrogenated borophene (”boro-phane”). We show that, according to the first-principles calculation, hydrogenated borophene is semimetallic, with two bands meeting at a single point at the Fermi level. The thermoelectric properties evaluated by using the Boltzmann equation with a constant relaxation time approximation (CRTA). At room temperature, we obtain large power factor for electron doping regime. Therefore, appropriate doping to this material can enhance its thermoelectric efficiency. [less ▲]

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See detailCan intermediaries assure contracts? Experimental evidence
Neugebauer, Tibor UL; Mitzkewitz

in Games and Economic Behavior (2020)

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See detailThermoelectric properties of two-dimensional Dirac materials
Hasdeo, Eddwi Hesky UL; Krisna, L. P. A.; Nugraha, A. R. T.

in AIP Conference Proceedings (2020), 2256(1), 030010

We performed Boltzmann transport calculation to obtain the Seebeck coefficient, electrical conductivity, electronic thermal conductivity, and thermoelectric figure of merit (ZT) for Dirac systems. We ... [more ▼]

We performed Boltzmann transport calculation to obtain the Seebeck coefficient, electrical conductivity, electronic thermal conductivity, and thermoelectric figure of merit (ZT) for Dirac systems. We found an enhancement of ZT due to the gap opening. When the phonon thermal conductivity is small enough, the optimum ZT in gapped Dirac system can be larger than 1, which is preferable for thermoelectric applications. [less ▲]

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See detailFastField: An Open-Source Toolbox for Efficient Approximation of Deep Brain Stimulation Electric Fields
Baniasadi, Mehri UL; Proverbio, Daniele UL; Goncalves, Jorge UL et al

in NeuroImage (2020)

Deep brain stimulation (DBS) is a surgical therapy to alleviate symptoms of certain brain disorders by electrically modulating neural tissues. Computational models predicting electric fields and volumes ... [more ▼]

Deep brain stimulation (DBS) is a surgical therapy to alleviate symptoms of certain brain disorders by electrically modulating neural tissues. Computational models predicting electric fields and volumes of tissue activated are key for efficient parameter tuning and network analysis. Currently, we lack efficient and flexible software implementations supporting complex electrode geometries and stimulation settings. Available tools are either too slow (e.g. finite element method–FEM), or too simple, with limited applicability to basic use-cases. This paper introduces FastField, an efficient open-source toolbox for DBS electric field and VTA approximations. It computes scalable e-field approximations based on the principle of superposition, and VTA activation models from pulse width and axon diameter. In benchmarks and case studies, FastField is solved in about 0.2s, ~ 1000 times faster than using FEM. Moreover, it is almost as accurate as using FEM: average Dice overlap of 92%, which is around typical noise levels found in clinical data. Hence, FastField has the potential to foster efficient optimization studies and to support clinical applications [less ▲]

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See detailCurrent correlations of Cooper-pair tunneling into a quantum Hall system
Michelsen, Andreas Nicolai Bock UL; Schmidt, Thomas UL; Idrisov, Edvin UL

in Physical Review. B, Condensed Matter and Materials Physics (2020), 102

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See detailApplication of the DAD method for damage 1 localisation on an existing bridge structure using 2 close-range UAV photogrammetry
Erdenebat, Dolgion; Waldmann, Danièle UL

in Engineering Structures (2020)

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load ... [more ▼]

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load-deflection experiments with the prerequisite of high precise deflection measurement. This study presents the first experiences of applying the DAD method on a real bridge structure. The investigated structure is a prestressed concrete slab bridge with a span of about 27 m, which was built in 2013. The loading on the bridge is applied using six heavy trucks, each weighing up to 32 t. A wide range of the modern measurement technologies were used to achieve high precision measurements of the bridge deflection along the longitudinal axis, namely the photogrammetry using a big size drone, laser scanner, total station, levelling and displacement sensors. The performed load-deflection test was non-destructive since the maximum deformation did not exceed the serviceability limit state. The exercise of the novel damage detection and localisation method on a real structure initiated further optimisation opportunities of the DAD method and the study of its limits. Several boundary conditions and methodical influence factors related to the applicability of the proposed method were analysed, such as impacts of measurement precision, damage degree, the position of damage, and the number of measurement repetitions. [less ▲]

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See detailAge of Information of One-Hop Broadcast Communications in a CSMA Network
Baiocchi, Andrea; Turcanu, Ion UL

in IEEE Communications Letters (2020), 25(1), 294-298

We consider a network of agents that send periodic updates to their neighbors. A trade-off between load on the shared communication channel and data timeliness is obtained by looking at the Age of ... [more ▼]

We consider a network of agents that send periodic updates to their neighbors. A trade-off between load on the shared communication channel and data timeliness is obtained by looking at the Age of Information (AoI) metric. We develop a model of a Carrier-Sense Multiple Access (CSMA) network with partial sensing, to calculate the AoI of one-hop broadcast messages exchanged among the agents. The model is applied to beacon messages in a vehicular network to gain insight into the impact of system parameters. [less ▲]

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See detailBorderland Child Heterotopias. A Case Study on the Belgian-German Borderlands
Venken, Machteld UL

in Journal of Borderlands Studies (2020)

This article investigates the capacities of children to participate actively in their lives in the Belgian-German borderlands in the time period between World War I and World War II. The article ... [more ▼]

This article investigates the capacities of children to participate actively in their lives in the Belgian-German borderlands in the time period between World War I and World War II. The article interprets a body of historical sources that has hitherto been left unexplored – namely, borderland child ego documents – with the help of insights from child studies and border studies. These ego documents unfold as borderland child heterotopias. Borderland child heterotopias include material places and creative linguistic loci established by or for those considered in crisis in relation to the rest of society based on their age within or outside child spaces of modernity. The borderland child heterotopias offer a unique gateway to borderland children’s past imaginations for a better world. [less ▲]

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See detailWeighted Sum-SINR and Fairness Optimization for SWIPT-Multigroup Multicasting Systems with Heterogeneous Users
Gautam, Sumit UL; Lagunas, Eva UL; Sharma, Shree Krishna UL et al

in IEEE Open Journal of the Communications Society (2020)

The development of next generation wireless communication systems focuses on the expansion of existing technologies, while ensuring an accord between various devices within a system. In this paper, we ... [more ▼]

The development of next generation wireless communication systems focuses on the expansion of existing technologies, while ensuring an accord between various devices within a system. In this paper, we target the aspect of precoder design for simultaneous wireless information and power transmission (SWIPT) in a multi-group (MG) multicasting (MC) framework capable of handling heterogeneous types of users, viz., information decoding (ID) specific, energy harvesting (EH) explicit, and/or both ID and EH operations concurrently. Precoding is a technique well-known for handling the inter-user interference in multi-user systems, however, the joint design with SWIPT is not yet fully exploited. Herein, we investigate the potential benefits of having a dedicated precoder for the set of users with EH demands, in addition to the MC precoding. We study the system performance of the aforementioned system from the perspectives of weighted sum of signal-to-interference-plus-noise-ratio (SINR) and fairness. In this regard, we formulate the precoder design problems for (i) maximizing the weighted sum of SINRs at the intended users and (ii) maximizing the minimum of SINRs at the intended users; both subject to the constraints on minimum (non-linear) harvested energy, an upper limit on the total transmit power and a minimum SINR required to close the link. We solve the above-mentioned problems using distinct iterative algorithms with the help of semi-definite relaxation (SDR) and slack-variable replacement (SVR) techniques, following suitable transformations pertaining the problem convexification. The main novelty of the proposed approach lies in the ability to jointly design the MC and EH precoders for serving the heterogeneously classified ID and EH users present in distinct groups, respectively. We illustrate the comparison between the proposed weighted sum-SINR and fairness models via simulation results, carried out under various parameter values and operating conditions. [less ▲]

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See detailPoroelastic model parameter identification using artificial neural networks: on the effects of heterogeneous porosity and solid matrix Poisson ratio
Dehghani, Hamidreza UL; Zilian, Andreas UL

in Computational Mechanics (2020), 66

Predictive analysis of poroelastic materials typically require expensive and time-consuming multiscale and multiphysics approaches, which demand either several simplifications or costly experimental tests ... [more ▼]

Predictive analysis of poroelastic materials typically require expensive and time-consuming multiscale and multiphysics approaches, which demand either several simplifications or costly experimental tests for model parameter identification. This problem motivates us to develop a more efficient approach to address complex problems with an acceptable computational cost. In particular, we employ artificial neural network (ANN) for reliable and fast computation of poroelastic model parameters. Based on the strong-form governing equations for the poroelastic problem derived from asymptotic homogenisation, the weighted residuals formulation of the cell problem is obtained. Approximate solution of the resulting linear variational boundary value problem is achieved by means of the finite element method. The advantages and downsides of macroscale properties identification via asymptotic homogenisation and the application of ANN to overcome parameter characterisation challenges caused by the costly solution of cell problems are presented. Numerical examples, in this study, include spatially dependent porosity and solid matrix Poisson ratio for a generic model problem, application in tumour modelling, and utilisation in soil mechanics context which demonstrate the feasibility of the presented framework. [less ▲]

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See detailFrom failure to emancipation: the case for a feminist research practice
Cima, Ottavia UL

in Feministische Geo-RundMail (2020), 83

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See detailMixed Integer Linear Programming and Constraint Programming Models for the Online Printing Shop Scheduling Problem
Tessaro Lunardi, Willian UL; Birgin, Ernesto G.; Laborie, Philippe et al

in Computers and Operations Research (2020)

In this work, the online printing shop scheduling problem is considered. This challenging real problem, that appears in the nowadays printing industry, can be seen as a flexible job shop scheduling ... [more ▼]

In this work, the online printing shop scheduling problem is considered. This challenging real problem, that appears in the nowadays printing industry, can be seen as a flexible job shop scheduling problem with sequence flexibility in which precedence constraints among operations of a job are given by an arbitrary directed acyclic graph. In addition, several complicating particularities such as periods of unavailability of the machines, resumable operations, sequence-dependent setup times, partial overlapping among operations with precedence constraints, release times, and fixed operations are also present in the addressed problem. In the present work, mixed integer linear programming and constraint programming models for the minimization of the makespan are presented. Modeling the problem is twofold. On the one hand, the problem is precisely defined. On the other hand, the capabilities and limitations of a commercial software for solving the models are analyzed. Extensive numerical experiments with small- , medium-, and large-sized instances are presented. Numerical experiments show that the commercial solver is able to optimally solve only a fraction of the small-sized instances when considering the mixed integer linear programming model; while all small-sized and a fraction of the medium-sized instances are optimally solved when considering the constraint programming formulation of the problem. Moreover, the commercial solver is able to deliver feasible solutions for the large-sized instances that are of the size of the instances that appear in practice. [less ▲]

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See detailCase Comment on CJEU C-405/18 AURES Holdings
Haslehner, Werner UL

in Highlights and Insights on European Taxation (2020)

This is a brief case comment on a judgment by the Court of Justice. The taxpayer in this case sought a deduction for losses incurred in the Netherlands prior to its change of residence to the Czech ... [more ▼]

This is a brief case comment on a judgment by the Court of Justice. The taxpayer in this case sought a deduction for losses incurred in the Netherlands prior to its change of residence to the Czech Republic, relying on the freedom of establishment to claim that denying the loss deduction would restrict it right to move without facing discrimination. Following its Advocate General, the Court dismissed this argument, holding that the situation of a company that had incurred losses at a time when it was outside of the tax jurisdiction of a Member State was not comparable to the situation of a company that incurred losses while being subject to that Member State's jurisdiction. The decision does not hold particular surprises, but is an important piece in search for a unified theory of two separate lines of jurisprudence: that concerning foreign loss relief and that concerning exit taxation. [less ▲]

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See detailErgodic Capapcity of NOMA-Based Satellite Networks with Randomly Deployed Users
Yan, Xiaojuan; Xiao, Hailin; An, Kang et al

in IEEE Systems Journal (2020), 14(3), 3343-3350

In this letter, we investigate the ergodic capacity of an uplink satellite network using a power-domain nonorthogonal multiple access (NOMA for simplicity) to serve users simultaneously in the ... [more ▼]

In this letter, we investigate the ergodic capacity of an uplink satellite network using a power-domain nonorthogonal multiple access (NOMA for simplicity) to serve users simultaneously in the consideration of random deployment of satellite users. Taking into account the deployed information of served users, we derive expression for the achievable ergodic capacity of the considered networks, where an entire link budget involving propagation loss, channel statistical prosperities, and location information is considered. Moreover, expression for ergodic capacity with OMA scheme is also derived to facilitate the performance comparison. Numerical simulation results are provided to attest the validity of theoretical results and show the vital effect of key parameters, such as the deployed information and link quality on the considered networks. [less ▲]

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See detailMultiscale Integration of High-Resolution Spaceborne and Drone-Based Imagery for a High-Accuracy Digital Elevation Model Over Tristan da Cunha
Backes, Dietmar UL; Teferle, Felix Norman UL

in Frontiers in Earth Science (2020)

Very high-resolution (VHR) optical Earth observation (EO) satellites as well as low-altitude and easy-to-use unmanned aerial systems (UAS/drones) provide ever-improving data sources for the generation of ... [more ▼]

Very high-resolution (VHR) optical Earth observation (EO) satellites as well as low-altitude and easy-to-use unmanned aerial systems (UAS/drones) provide ever-improving data sources for the generation of detailed 3-dimensional (3D) data using digital photogrammetric methods with dense image matching. Today both data sources represent cost-effective alternatives to dedicated airborne sensors, especially for remote regions. The latest generation of EO satellites can collect VHR imagery up to 0.30 m ground sample distance (GSD) of even the most remote location from different viewing angles many times per year. Consequently, well-chosen scenes from growing image archives enable the generation of high-resolution digital elevation models (DEMs). Furthermore, low-cost and easy to use drones can be quickly deployed in remote regions to capture blocks of images of local areas. Dense point clouds derived from these methods provide an invaluable data source to fill the gap between globally available low-resolution DEMs and highly accurate terrestrial surveys. Here we investigate the use of archived VHR satellite imagery with approx. 0.5 m GSD as well as low-altitude drone-based imagery with average GSD of better than 0.03 m to generate high-quality DEMs using photogrammetric tools over Tristan da Cunha, a remote island in the South Atlantic Ocean which lies beyond the reach of current commercial manned airborne mapping platforms. This study explores the potentials and limitations to combine this heterogeneous data sources to generate improved DEMs in terms of accuracy and resolution. A cross-validation between low-altitude airborne and spaceborne data sets describes the fit between both optical data sets. No co-registration error, scale difference or distortions were detected, and a quantitative cloud-to-cloud comparison showed an average distance of 0.26 m between both point clouds. Both point clouds were merged applying a conventional georeferenced approach. The merged DEM preserves the rich detail from the drone-based survey and provides an accurate 3D representation of the entire study area. It provides the most detailed model of the island to date, suitable to support practical and scientific applications. This study demonstrates that combination archived VHR satellite and low-altitude drone-based imagery provide inexpensive alternatives to generate high-quality DEMs. [less ▲]

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See detailRemoving the saturation assumption in Bank-Weiser error estimator analysis in dimension three
Bulle, Raphaël UL; Chouly, Franz; Hale, Jack UL et al

in Applied Mathematics Letters (2020), 107

We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes ... [more ▼]

We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes the main novelty of our study. In addition, we present a numerical comparison of the Bank-Weiser and residual estimators for a three-dimensional test case. [less ▲]

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See detailShort- and Long-Term Impacts of Workplace Relocation: A Survey and Experience from the University of Luxembourg Relocation
Sprumont, François; Benam, Ali Shateri; Viti, Francesco UL

in Sustainability (2020), 12(18),

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See detailInvestigating the Relationship between Controller Locations and Dynamic Traffic Control in Generic Transportation Networks
Rinaldi, Marco UL; Viti, Francesco UL

in Transportation Research Record: Journal of the Transportation Research Board (2020), 2674(5), 172-182

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See detailA three-level classification of French tweets in ecological crises
Kozlowski, Diego UL; Lannelongue, Elisa; Saudemont, Frédéric et al

in Information Processing and Management (2020), 57(5),

The possibilities that emerge from micro-blogging generated content for crisis-related situations make automatic crisis management using natural language processing techniques a hot research topic. Our ... [more ▼]

The possibilities that emerge from micro-blogging generated content for crisis-related situations make automatic crisis management using natural language processing techniques a hot research topic. Our aim here is to contribute to this line of research focusing for the first time on French tweets related to ecological crises in order to support the French Civil Security and Crisis Management Department to provide immediate feedback on the expectations of the populations involved in the crisis. We propose a new dataset manually annotated according to three dimensions: relatedness, urgency and intentions to act. We then experiment with binary classification (useful vs. non useful), three-class (non useful vs. urgent vs. non urgent) and multiclass classification (i.e., intention to act categories) relying on traditional feature-based machine learning using both state of the art and new features. We also explore several deep learning models trained with pre-trained word embeddings as well as contextual embeddings. We then investigate three transfer learning strategies to adapt these models to the crisis domain. We finally experiment with multi-input architectures by incorporating different metadata extra-features to the network. Our deep models, evaluated in random sampling, out-of-event and out-of-type configurations, show very good performances outperforming several competitive baselines. Our results define the first contribution to the field of crisis management in French social media. [less ▲]

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See detailRiemannian Structures on Z 2 n -Manifolds
Bruce, Andrew UL; Grabowski, Janusz

in Mathematics (2020), 8(9), 1469

Very loosely, Zn2-manifolds are ‘manifolds’ with Zn2-graded coordinates and their sign rule is determined by the scalar product of their Zn2-degrees. A little more carefully, such objects can be ... [more ▼]

Very loosely, Zn2-manifolds are ‘manifolds’ with Zn2-graded coordinates and their sign rule is determined by the scalar product of their Zn2-degrees. A little more carefully, such objects can be understood within a sheaf-theoretical framework, just as supermanifolds can, but with subtle differences. In this paper, we examine the notion of a Riemannian Zn2-manifold, i.e., a Zn2-manifold equipped with a Riemannian metric that may carry non-zero Zn2-degree. We show that the basic notions and tenets of Riemannian geometry directly generalize to the setting of Zn2-geometry. For example, the Fundamental Theorem holds in this higher graded setting. We point out the similarities and differences with Riemannian supergeometry [less ▲]

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See detailEfficient Detectors for Telegram Splitting based Transmission in Low Power Wide Area Networks with Bursty Interference
Kisseleff, Steven UL; Kneissl, Jakob; Kilian, Gerd et al

in IEEE Transactions on Communications (2020)

Low Power Wide Area (LPWA) networks are known to be highly vulnerable to external in-band interference in terms of packet collisions which may substantially degrade the system performance. In order to ... [more ▼]

Low Power Wide Area (LPWA) networks are known to be highly vulnerable to external in-band interference in terms of packet collisions which may substantially degrade the system performance. In order to enhance the performance in such cases, the telegram splitting (TS) method has been proposed recently. This approach exploits the typical burstiness of the interference via forward error correction (FEC) and offers a substantial performance improvement compared to other methods for packet transmissions in LPWA networks. While it has been already demonstrated that the TS method benefits from knowledge on the current interference state at the receiver side, corresponding practical receiver algorithms of high performance are still missing. The modeling of the bursty interference via Markov chains leads to the optimal detector in terms of a-posteriori symbol error probability. However, this solution requires a high computational complexity, assumes an a-priori knowledge on the interference characteristics and lacks flexibility. We propose a further developed scheme with increased flexibility and introduce an approach to reduce its complexity while maintaining a close-to-optimum performance. In particular, the proposed low complexity solution substantially outperforms existing practical methods in terms of packet error rate and therefore is highly beneficial for practical LPWA network scenarios. [less ▲]

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See detailMultilingualism as a resource for learning–insights from a multidisciplinary research project
Hu, Adelheid; de Saint-Georges, Ingrid UL

in European Journal of Applied Linguistics (2020), 8(2), 143-156

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See detailCovid-19 and labour law in Spain
Garcia Munoz Alhambra, Manuel Antonio UL

in European Labour Law Journal (2020), 11(3), 319-323

The Covid-19 crisis in Spain has led to the adoption of several pieces of legislation with labour law and social security content. The main priority of this fast-changing and frequently adapted ... [more ▼]

The Covid-19 crisis in Spain has led to the adoption of several pieces of legislation with labour law and social security content. The main priority of this fast-changing and frequently adapted legislation has been to avoid a sharp rise in unemployment. To do so, the legislator facilitated the use of the already existing procedures to temporarily suspend contracts (Expedientes Temporales de Regulacion de Empleo) ´ and prohibited certain kinds of dismissals (those based on economic circumstances and force majeure). To further develop a social shield with the ambition to protect the most vulnerable workers and families several measures that can be classified as income support have been adopted. [less ▲]

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See detailThe search for the perfect match: Aligning power-trading products to the energy transition
Fridgen, Gilbert UL; Michaelis, Anne; Rinck, Maximilian et al

in Energy Policy (2020), 144

Given the growing share of uncertain renewable energy production, the energy transition challenges modern power systems and especially calls for increased flexibility. However, relevant information on the ... [more ▼]

Given the growing share of uncertain renewable energy production, the energy transition challenges modern power systems and especially calls for increased flexibility. However, relevant information on the highly assetspecific flexibility potential is typically only known to plant operators themselves and not, e.g., to transmission system operators. Therefore, liberalized electricity markets use prices that set explicit monetary incentives to disclose the relevant private information about the market participants’ assets. In this way, information asymmetries may be reduced. Given the different challenges of an integration of renewables, we argue that the associated new forms of volatile power profiles require new forms of power-trading products. In particular, based on recent advances in technical power measurement and billing, individual and market participant-specific power profiles may be superior to the current trading of average volumes. Against this background, we first outline various evolutionary adjustments of existing power-trading products and their underlying product parameters including (1) strengthening local pricing, (2) finer temporal granularity, (3) smaller minimum volume, and (4) shorter gate-closure time. Second, we open up a new perspective in form of a more disruptive shift towards power-profile trade, where market participants define their trading product using the actual power profile as a new product parameter. [less ▲]

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See detailSystematic transcriptional profiling of responses to STAT1- and STAT3- activating cytokines in different cancer types
Kirchmeyer, Mélanie UL; Servais, Florence UL; Ginolhac, Aurélien UL et al

in Journal of Molecular Biology (2020)

Cytokines orchestrate responses to pathogens and in inflammatory processes but they also play an important role in cancer by shaping the expression levels of cytokine response genes. Here, we conducted a ... [more ▼]

Cytokines orchestrate responses to pathogens and in inflammatory processes but they also play an important role in cancer by shaping the expression levels of cytokine response genes. Here, we conducted a large profiling study comparing miRNome and mRNA transcriptome data generated following different cytokine stimulations. Transcriptomic responses to STAT1- (IFN, IL-27) and STAT3-activating cytokines (IL6, OSM) were systematically compared in nine cancerous and nonneoplastic cell lines of different tissue origins (skin, liver and colon). The largest variation in our datasets was seen between cell lines of the three different tissues rather than stimuli. Notably, the variability in miRNome datasets was a lot more pronounced than in mRNA data. Our data also revealed that cells of skin, liver and colon tissues respond very differently to cytokines and that the cell signaling networks activated or silenced in response to STAT1- or STAT3- activating cytokines are specific to the tissue and the type of cytokine. However, globally, STAT1-activating cytokines had stronger effects than STAT3-inducing cytokines with most significant responses in liver cells, showing more genes up-regulated and with higher fold change. A more detailed analysis of gene regulations upon cytokine stimulation in these cells provided insights into STAT1- versus STAT3-driven processes in hepatocarcinogenesis. Finally, independent component analysis revealed interconnected transcriptional networks distinct between cancer cells and their healthy counterparts. [less ▲]

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See detailCarrier Aggregation in Satellite Communications: Impact and Performance Study
Kibria, Mirza; Lagunas, Eva UL; Maturo, Nicola UL et al

in IEEE Open Journal of the Communications Society (2020)

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See detailLearn to Make Decision with Small Data for Autonomous Driving : Deep Gaussian Process and Feedback Control
Fang, Wenqi; Zhang, Shitian; Huang, Hui UL et al

in Journal of Advanced Transportation (2020), 2020

Autonomous driving is a popular and promising field in artificial intelligence. Rapid decision of the next action according to the latest few actions and status, such as acceleration, brake, and steering ... [more ▼]

Autonomous driving is a popular and promising field in artificial intelligence. Rapid decision of the next action according to the latest few actions and status, such as acceleration, brake, and steering angle, is a major concern for autonomous driving. There are some learning methods, such as reinforcement learning which automatically learns the decision. However, it usually requires large volume of samples. In this paper, to reduce the sample size, we exploit the deep Gaussian process, where a regression model is trained on small sample datasets and captures the most significant features correctly. Besides, to realize the real-time and close-loop control, we combine the feedback control into the process. Experimental results on the Torcs simulation engine illustrate smooth driving on virtual road which can be achieved. Compared with the amount of training data in deep reinforcement learning, our method uses only 0.34\% of its size and obtains similar simulation results. It may be useful for real road tests in the future. [less ▲]

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See detailFading Away... The challenge of sustainability in digital studies
Barats, Christine; Schafer, Valerie UL; Fickers, Andreas UL

in Digital Humanities Quarterly (2020), 14(3),

This paper emphasizes the need to think about sustainability as a key element of digital studies and digital hermeneutics. It addresses the inherent tensions between the long-term needs of data ... [more ▼]

This paper emphasizes the need to think about sustainability as a key element of digital studies and digital hermeneutics. It addresses the inherent tensions between the long-term needs of data preservation and maintenance on the one side, and the short life cycles of the data formats, platforms and infrastructures on the other side. Challenges are not limited to the technical maintenance of software, tools and data, but also apply to the wider institutional contexts, epistemic traditions and social practices in which the doing of research in social sciences and humanities are embedded. We explore these tensions at several levels, temporalities and key stages in research – namely data access and building a corpus, establishing a research framework and analysis, and finally the use/dissemination of results. [less ▲]

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See detailActive Content Popularity Learning and Caching Optimization with Hit Ratio Guarantees
Bommaraveni, Srikanth UL; Vu, Thang Xuan UL; Chatzinotas, Symeon UL et al

in Active Content Popularity Learning and Caching Optimization with Hit Ratio Guarantees (2020), 8

Edge caching is an effective solution to reduce delivery latency and network congestion by bringing contents close to end-users. A deep understanding of content popularity and the principles underlying ... [more ▼]

Edge caching is an effective solution to reduce delivery latency and network congestion by bringing contents close to end-users. A deep understanding of content popularity and the principles underlying the content request sequence are required to effectively utilize the cache. Most existing works design caching policies based on global content requests with very limited consideration of individual content requests which reflect personal preferences. To enable the optimal caching strategy, in this paper, we propose an Active learning (AL) approach to learn the content popularities and design an accurate content request prediction model. We model the content requests from user terminals as a demand matrix and then employ AL-based query-by-committee (QBC) matrix completion to predict future missing requests. The main principle of QBC is to query the most informative missing entries of the demand matrix. Based on the prediction provided by the QBC, we propose an adaptive optimization caching framework to learn popularities as fast as possible while guaranteeing an operational cache hit ratio requirement. The proposed framework is model-free, thus does not require any statistical knowledge about the underlying traffic demands. We consider both the fixed and time-varying nature of content popularities. The effectiveness of the proposed learning caching policies over the existing methods is demonstrated in terms of root mean square error, cache hit ratio, and cache size on a simulated dataset. [less ▲]

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See detailMitochondrial Mechanisms of LRRK2 G2019S Penetrance
Delcambre, Sylvie UL; Ghelfi, Jenny UL; Ouzren, Nassima et al

in Frontiers in Neurology (2020)

Several mutations in leucine-rich repeat kinase-2 (LRRK2) have been associated with Parkinson’s disease (PD). The most common substitution, G2019S, interferes with LRRK2 kinase activity, which is ... [more ▼]

Several mutations in leucine-rich repeat kinase-2 (LRRK2) have been associated with Parkinson’s disease (PD). The most common substitution, G2019S, interferes with LRRK2 kinase activity, which is regulated by autophosphorylation. Yet, the penetrance of this gain-of-function mutation is incomplete, and thus far, few factors have been correlated with disease status in carriers. This includes (i) LRRK2 autophosphorylation in urinary exosomes, (ii) serum levels of the antioxidant urate, and (iii) abundance of mitochondrial DNA (mtDNA) transcription-associated 7S DNA. In light of a mechanistic link between LRRK2 kinase activity and mtDNA lesion formation, we previously investigated mtDNA integrity in fibroblasts from manifesting (LRRK2+/PD+) and non-manifesting carriers (LRRK2+/PD−) of the G2019S mutation as well as from aged-matched controls. In our published study, mtDNA major arc deletions correlated with PD status, with manifesting carriers presenting the highest levels. In keeping with these findings, we now further explored mitochondrial features in fibroblasts derived from LRRK2+/PD+ (n = 10), LRRK2+/PD− (n = 21), and control (n = 10) individuals. In agreement with an accumulation of mtDNA major arc deletions, we also detected reduced NADH dehydrogenase activity in the LRRK2+/PD+ group. Moreover, in affected G2019S carriers, we observed elevated mitochondrial mass and mtDNA copy numbers as well as increased expression of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates antioxidant signaling. Taken together, these results implicate mtDNA dyshomeostasis—possibly as a consequence of impaired mitophagy—in the penetrance of LRRK2-associated PD. Our findings are a step forward in the pursuit of unveiling markers that will allow monitoring of disease progression of LRRK2 mutation carriers [less ▲]

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See detailPublishing Community-Preserving Attributed Social Graphs with a Differential Privacy Guarantee
Chen, Xihui UL; Mauw, Sjouke UL; Ramirez Cruz, Yunior UL

in Proceedings on Privacy Enhancing Technologies (2020), 2020(4), 131-152

We present a novel method for publishing differentially private synthetic attributed graphs. Our method allows, for the first time, to publish synthetic graphs simultaneously preserving structural ... [more ▼]

We present a novel method for publishing differentially private synthetic attributed graphs. Our method allows, for the first time, to publish synthetic graphs simultaneously preserving structural properties, user attributes and the community structure of the original graph. Our proposal relies on CAGM, a new community-preserving generative model for attributed graphs. We equip CAGM with efficient methods for attributed graph sampling and parameter estimation. For the latter, we introduce differentially private computation methods, which allow us to release communitypreserving synthetic attributed social graphs with a strong formal privacy guarantee. Through comprehensive experiments, we show that our new model outperforms its most relevant counterparts in synthesising differentially private attributed social graphs that preserve the community structure of the original graph, as well as degree sequences and clustering coefficients. [less ▲]

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See detailMonotonic axial compressive behaviour and confinement mechanism of square CFRP-steel tube confined concrete
Wang, Yanlei; Cai, Gaochuang; Si Larbi, Amir et al

in Engineering Structures (2020)

Steel tube confined concrete (STCC) is widely used in the vertical members of high-rise buildings such as columns. The axial load is not directly resisted by the steel tube in STCC, but is resisted via ... [more ▼]

Steel tube confined concrete (STCC) is widely used in the vertical members of high-rise buildings such as columns. The axial load is not directly resisted by the steel tube in STCC, but is resisted via the interfacial frictional stress between steel tube and concrete core, which is different with that of concrete filled steel tube (CFT) members and would effectively suppress the outward local buckling of steel tube at early stage. Recently, fibre-reinforced polymer (FRP) confined STCC presents a potential to enhance the ductility and durability of such vertical elements. This paper presents an experimental study on monotonic axial compressive behaviour of carbon FRP (CFRP) confined STCC (CFRP- STCC) stub column and an analytical study on the confinement mechanism of and the ultimate axial bearing capacity of the elements. A three-stage confinement mechanism involving the different contributions of the steel tube and the CFRP wrap in CFRP-STCC elements was proposed based on the test results. A prediction model of the ultimate axial bearing capacity of CFRP-STCC stub columns was developed subsequently. Results show that the presence of CFRP wrap enhances effectively the load-bearing capacity and the ductility of steel tube confined plain concrete and reinforced concrete elements, and significantly prevents the local buckling of the steel tubes in the elements. The proposed prediction model of ultimate axial bearing capacity assesses test results with a great agreement. [less ▲]

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See detailRobust Probabilistic-Constrained Optimization for IRS-Aided MISO Communication Systems
Le, Anh Tuan; Trinh, van Chien UL; Di Renzo, Marco

in IEEE Wireless Communications Letters (2020)

Taking into account imperfect channel state information, this letter formulates and solves a joint active/passive beamforming optimization problem in multiple-input single-output systems with the support ... [more ▼]

Taking into account imperfect channel state information, this letter formulates and solves a joint active/passive beamforming optimization problem in multiple-input single-output systems with the support of an intelligent reflecting surface. In particular, we introduce an optimization problem to minimize the total transmit power subject to maintaining the users' signal-to-interference-plus-noise-ratio coverage probability above a predefined target. Due to the presence of probabilistic constraints, the proposed optimization problem is non-convex. To circumvent this issue, we first recast the proposed problem in a convex form by adopting the Bernstein-type inequality, and we then introduce a converging alternating optimization approach to iteratively find the active/passive beamforming vectors. In particular, the transformed robust optimization problem can be effectively solved by using standard interior-point methods. Numerical results demonstrate the effectiveness of jointly optimizing the active/passive beamforming vectors. [less ▲]

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See detailUnraveling Nanostructured Spin Textures in Bulk Magnets
Bender, Philipp Florian UL; Leliaert, Jonathan; Bersweiler, Mathias UL et al

in Small Science (2020), 1(1), 2000003

One of the key challenges in magnetism remains the determination of the nanoscopic magnetization profile within the volume of thick samples, such as permanent ferromagnets. Thanks to the large penetration ... [more ▼]

One of the key challenges in magnetism remains the determination of the nanoscopic magnetization profile within the volume of thick samples, such as permanent ferromagnets. Thanks to the large penetration depth of neutrons, magnetic small-angle neutron scattering (SANS) is a powerful technique to characterize bulk samples. The major challenge regarding magnetic SANS is accessing the real-space magnetization vector field from the reciprocal scattering data. In this letter, a fast iterative algorithm is introduced that allows one to extract the underlying two-dimensional magnetic correlation functions from the scattering patterns. This approach is used here to analyze the magnetic microstructure of Nanoperm, a nanocrystalline alloy which is widely used in power electronics due to its extraordinary soft magnetic properties. It can be shown that the computed correlation functions clearly reflect the projection of the three-dimensional magnetization vector field onto the detector plane, which demonstrates that the used methodology can be applied to probe directly spin-textures within bulk samples with nanometer-resolution. This article is protected by copyright. All rights reserved. [less ▲]

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See detailRadial processes for sub-Riemannian Brownian motions and applications
Baudoin, Fabrice; Grong, Erlend; Kuwada, Kazumasa et al

in Electronic Journal of Probability (2020), 25(paper no. 97), 1-17

We study the radial part of sub-Riemannian Brownian motion in the context of totally geodesic foliations. Itô's formula is proved for the radial processes associated to Riemannian distances approximating ... [more ▼]

We study the radial part of sub-Riemannian Brownian motion in the context of totally geodesic foliations. Itô's formula is proved for the radial processes associated to Riemannian distances approximating the Riemannian one. We deduce very general stochastic completeness criteria for the sub-Riemannian Brownian motion. In the context of Sasakian foliations and H-type groups, one can push the analysis further, and taking advantage of the recently proved sub-Laplacian comparison theorems one can compare the radial processes for the sub-Riemannian distance to one-dimensional model diffusions. As a geometric application, we prove Cheng's type estimates for the Dirichlet eigenvalues of the sub-Riemannian metric balls, a result which seems to be new even in the Heisenberg group. [less ▲]

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See detailPredicting functional effects of missense variants in voltage-gated sodium and calcium channels
Heyne, Henrike O.; Baez-Nieto, David; Iqbal, Sumaiya et al

in Science Translational Medicine (2020), 12(556), 6848

Malfunctions of voltage-gated sodium and calcium channels (encoded by SCNxA and CACNA1x family genes, respectively) have been associated with severe neurologic, psychiatric, cardiac, and other diseases ... [more ▼]

Malfunctions of voltage-gated sodium and calcium channels (encoded by SCNxA and CACNA1x family genes, respectively) have been associated with severe neurologic, psychiatric, cardiac, and other diseases. Altered channel activity is frequently grouped into gain or loss of ion channel function (GOF or LOF, respectively) that often corresponds not only to clinical disease manifestations but also to differences in drug response. Experimental studies of channel function are therefore important, but laborious and usually focus only on a few variants at a time. On the basis of known gene-disease mechanisms of 19 different diseases, we inferred LOF (n = 518) and GOF (n = 309) likely pathogenic variants from the disease phenotypes of variant carriers. By training a machine learning model on sequence- and structure-based features, we predicted LOF or GOF effects [area under the receiver operating characteristics curve (ROC) = 0.85] of likely pathogenic missense variants. Our LOF versus GOF prediction corresponded to molecular LOF versus GOF effects for 87 functionally tested variants in SCN1/2/8A and CACNA1I (ROC = 0.73) and was validated in exome-wide data from 21,703 cases and 128,957 controls. We showed respective regional clustering of inferred LOF and GOF nucleotide variants across the alignment of the entire gene family, suggesting shared pathomechanisms in the SCNxA/CACNA1x family genes. [less ▲]

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See detailAnalysing the SWECOM Standard for Designing a DevOps Education Programme
Capozucca, Alfredo UL; Guelfi, Nicolas UL

in In: Bruel JM., Capozucca A., Mazzara M., Meyer B., Naumchev A., Sadovykh A. (eds) Frontiers in Software Engineering Education. FISEE 2019. Lecture Notes in Computer Science (2020), 12271

Developing academic education programmes for software engineers is a difficult task mainly due to three main factors: (1) ever-changing information and communication technologies produced by the industry ... [more ▼]

Developing academic education programmes for software engineers is a difficult task mainly due to three main factors: (1) ever-changing information and communication technologies produced by the industry and meant for citizens living in digital disruptions age, (2) lack of official or de-facto standards for the software engineering domain, (3) slow pace of the standardisation bodies and of the academia for deploying standard competence frameworks or education programmes. This applies more especially to DevOps which regroups a set of skills being the most demanded today by the job market. This paper is a first attempt to introduce a standard based development process to derive a DevOps education programme for graduate education. It is introduced as a generic process mainly based on the SWECOM standard. This process is applied to generate a proposal for a significant DevOps graduate academic programme definition in a comprehensive and, most importantly, in a skill oriented manner. [less ▲]

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See detailYoung children’s language-based agency in multilingual contexts in Luxembourg and Israel
Schwartz, Mila; Kirsch, Claudine UL; Mortini, Simone

in Applied Linguistics Review (2020)

Drawing on two longitudinal case-studies, this study aimed to identify some salient characteristics of the agentic behaviour of two young emergent multilinguals in two different multilingual contexts ... [more ▼]

Drawing on two longitudinal case-studies, this study aimed to identify some salient characteristics of the agentic behaviour of two young emergent multilinguals in two different multilingual contexts: Luxembourg and Israel. Despite the fact that the studies were conducted independently, the two cases were analysed together owing to the similarities in the research methods such as video-recorded observations, and semi-structured interviews with teachers and parents. The data were analysed through thematic and conversational analyses. Findings showed that a boy who learned Luxembourgish in Luxembourg and a girl who learned Hebrew in Israel, were outgoing and active learners who influenced their learning environment. We identified ten types of agentic behaviour, including engaging in repetition after peers and the teacher, creatively producing language, translanguaging, and self-monitoring. Despite differences of the children's sociocultural and linguistic backgrounds, and the language policies of their educational settings, we found a striking overlap in their language-based agentic behaviours. We suggest that the identified types can encourage further research in this field. Although our study with talkative children allowed us to observe many types of agentic behaviours, we cannot claim that less outgoing children or children who do not show the same behaviours do not have ways of expressing their agency. [less ▲]

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See detailA Survey of Computer Vision Methods for 2D Object Detection from Unmanned Aerial Vehicles
Cazzato, Dario UL; Cimarelli, Claudio UL; Sanchez Lopez, Jose Luis UL et al

in Journal of Imaging (2020), 6(8), 78

The spread of Unmanned Aerial Vehicles (UAVs) in the last decade revolutionized many applications fields. Most investigated research topics focus on increasing autonomy during operational campaigns ... [more ▼]

The spread of Unmanned Aerial Vehicles (UAVs) in the last decade revolutionized many applications fields. Most investigated research topics focus on increasing autonomy during operational campaigns, environmental monitoring, surveillance, maps, and labeling. To achieve such complex goals, a high-level module is exploited to build semantic knowledge leveraging the outputs of the low-level module that takes data acquired from multiple sensors and extracts information concerning what is sensed. All in all, the detection of the objects is undoubtedly the most important low-level task, and the most employed sensors to accomplish it are by far RGB cameras due to costs, dimensions, and the wide literature on RGB-based object detection. This survey presents recent advancements in 2D object detection for the case of UAVs, focusing on the differences, strategies, and trade-offs between the generic problem of object detection, and the adaptation of such solutions for operations of the UAV. Moreover, a new taxonomy that considers different heights intervals and driven by the methodological approaches introduced by the works in the state of the art instead of hardware, physical and/or technological constraints is proposed. [less ▲]

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See detailThe application of factorial surveys to study recruiters’ hiring intentions: comparing designs based on hypothetical and real vacancies
Gutfleisch, Tamara Rebecca UL; Samuel, Robin UL; Sacchi, Stefan

in Quality and Quantity (2020)

Factorial survey experiments have been widely used to study recruiters’ hiring intentions. Respondents are asked to evaluate hypothetical applicant descriptions, which are experimentally manipulated, for ... [more ▼]

Factorial survey experiments have been widely used to study recruiters’ hiring intentions. Respondents are asked to evaluate hypothetical applicant descriptions, which are experimentally manipulated, for hypothetical job descriptions. However, this methodology has been criticized for putting respondents in hypothetical situations that often only partially correspond to real-life hiring situations. It has been proposed that this criticism can be overcome by sampling real-world vacancies and the recruiters responsible for filling them. In such an approach, only the applicants’ descriptions are hypothetical; respondents are asked about a real hiring problem, which might increase internal and external validity. In this study, we test whether using real vacancies triggers more valid judgments compared to designs based on hypothetical vacancies. The growing number of factorial survey experiments conducted in employer studies makes addressing this question relevant, both for methodological and practical reasons. However, despite the potential implications for the validity of data, it has been neglected so far.We conducted a factorial survey experiment in Luxembourg, in which respondents evaluated hypothetical applicants referring either to a currently vacant position in their company or to a hypothetical job. Overall, we found little evidence for differences in responses by the design of the survey experiment. However, the use of real vacancies might prove beneficial depending on the research interest.We hope that our comparison of designs using real and hypothetical vacancies contributes to the emerging methodological inquiry on the possibilities and limits of using factorial survey experiments in research on hiring. [less ▲]

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See detailInfluence of Thermal Energy Storage and Heat Pump Parametrization for Demand-Side-Management in a Nearly-Zero-Energy-Building using Model Predictive Control
Bechtel, Steffen UL; Rafii-Tabrizi, Sasan UL; Scholzen, Frank UL et al

in Energy and Buildings (2020), 226

The rollout of the supply dependent generators wind turbines and photovoltaics leads to a flexibility demand that can be adressed from the consumer side, via Demand-Side-Management, as well. In single ... [more ▼]

The rollout of the supply dependent generators wind turbines and photovoltaics leads to a flexibility demand that can be adressed from the consumer side, via Demand-Side-Management, as well. In single family houses, the heat pump, in combination with thermal energy storage, can shift their energy comsumption according to price signals in order to reduce consumer costs. This paper analyses the impact of different heat storage sizes and heat pump powers on cost savings and shifting potential, focussing on the Luxembourgish context, when variable electricity prices based on the electricity market are applied. A model predictive controller determines the cost-optimal operating cycles of the heat pump. The building’s heat demand is predicted with the help of a neural network. The results of the parametric study show significant differences in energy efficiency and cost savings. Furthermore limitations of taking advantage of variable electicity prices due to the price structure are disclosed. The cost savings however do not give a sufficient incentive for the consumer to invest in optimizing the heating system for Demand-Side-Management purposes. By consequence, the potential and the efficiency of Demand-Side-Management are limited and further incentives are necessary. [less ▲]

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See detailMUSIC EDUCATION IN TIMES OF CORONA. Some Considerations about Music Education and the Content-based Research Programme of the Hungarian Academy of Sciences
Sagrillo, Damien François UL

in Magyar Tudomany: A Magyar Tudomanyos Akademia Ertesitoje (2020), 181(8), 1048-1052

This essay was written at a time when the coronavirus crisis was at its height. For many peo-ple being confined to their homes is a new experience in their lives. There is hardly anyone on the street. The ... [more ▼]

This essay was written at a time when the coronavirus crisis was at its height. For many peo-ple being confined to their homes is a new experience in their lives. There is hardly anyone on the street. The soundscape outside changes, and we experience for the first time what silence means. No one knows how this crisis will end, but among all the negative consequences that humankind will have to face there will be a positive outcome too – it will sharpen the eyesight for new offers and opportunities in delivering knowledge, also for music education [less ▲]

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See detailThe Importance of Computational Modeling in Stem Cell Research
Del Sol Mesa, Antonio UL

in Trends in Biotechnology (2020)

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See detailA Comprehensive Survey of Enabling and Emerging Technologies for Social Distancing—Part II: Emerging Technologies and Open Issues
Nguyen, Cong T.; Saputra, Yuris M.; Nguyen, Huynh Van et al

in IEEE Access (2020)

This two-part paper aims to provide a comprehensive survey on how emerging technologies, e.g., wireless and networking, artificial intelligence (AI) can enable, encourage, and even enforce social ... [more ▼]

This two-part paper aims to provide a comprehensive survey on how emerging technologies, e.g., wireless and networking, artificial intelligence (AI) can enable, encourage, and even enforce social distancing practice. In Part I, an extensive background of social distancing is provided, and enabling wireless technologies are thoroughly surveyed. In this Part II, emerging technologies such as machine learning, computer vision, thermal, ultrasound, etc., are introduced. These technologies open many new solutions and directions to deal with problems in social distancing, e.g., symptom prediction, detection and monitoring quarantined people, and contact tracing. Finally, we discuss open issues and challenges (e.g., privacy-preserving, scheduling, and incentive mechanisms) in implementing social distancing in practice. As an example, instead of reacting with ad-hoc responses to COVID-19-like pandemics in the future, smart infrastructures (e.g., next-generation wireless systems like 6G, smart home/building, smart city, intelligent transportation systems) should incorporate a pandemic mode in their standard architectures/designs. [less ▲]

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See detailA Comprehensive Survey of Enabling and Emerging Technologies for Social Distancing—Part I: Fundamentals and Enabling Technologies
Nguyen, Cong T.; Saputra, Yuris M.; Nguyen, Huynh Van et al

in IEEE Access (2020), 8

Social distancing plays a pivotal role in preventing the spread of viral diseases illnesses such as COVID-19. By minimizing the close physical contact among people, we can reduce the chances of catching ... [more ▼]

Social distancing plays a pivotal role in preventing the spread of viral diseases illnesses such as COVID-19. By minimizing the close physical contact among people, we can reduce the chances of catching the virus and spreading it across the community. This two-part paper aims to provide a comprehensive survey on how emerging technologies, e.g., wireless and networking, artificial intelligence (AI) can enable, encourage, and even enforce social distancing practice. In this Part I, we provide a comprehensive background of social distancing including basic concepts, measurements, models, and propose various practical social distancing scenarios. We then discuss enabling wireless technologies which are especially effect in social distancing, e.g., symptom prediction, detection and monitoring quarantined people, and contact tracing. The companion paper Part II surveys other emerging and related technologies, such as machine learning, computer vision, thermal, ultrasound, etc., and discusses open issues and challenges (e.g., privacy preserving, scheduling, and incentive mechanisms) in implementing social distancing in practice [less ▲]

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See detailCovid-19 et le respect des droits humains: Une obligation pour l'état, une responsabilité pour les entreprises
Baglayan, Basak UL; Bichler, Marc

in Revue Luxembourgeoise de Droit Public (2020), (6),

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See detailOn the Spectral and Energy Efficiencies of Full-Duplex Cell-Free Massive MIMO
Nguyen, Hieu V.; Nguyen, van Dinh UL; Dobre, Octavia A. et al

in IEEE Journal on Selected Areas in Communications (2020), 38(8), 1698-1718

In-band full-duplex (FD) operation is practically more suited for short-range communications such as WiFi and small-cell networks, due to its current practical limitations on the self-interference ... [more ▼]

In-band full-duplex (FD) operation is practically more suited for short-range communications such as WiFi and small-cell networks, due to its current practical limitations on the self-interference cancellation. In addition, cell-free massivemultiple-input multiple-output (CF-mMIMO) is a new and scalable version of MIMO networks, which is designed to bring service antennas closer to end user equipments (UEs). To achieve higher spectral and energy efficiencies (SE-EE) of a wireless network, it is of practical interest to incorporate FD capability into CF-mMIMO systems to utilize their combined benefits. We formulate a novel and comprehensive optimization problem for the maximization of SE and EE in which power control, access point-UE (AP-UE) association and AP selection are jointly optimized under a realistic power consumption model, resulting in a difficult class of mixed-integer nonconvex programming. To tackle the binary nature of the formulated problem, we propose an efficient approach by exploiting a strong coupling between binary and continuous variables, leading to a more tractable problem. In this regard, two low-complexity transmission designs based on zero-forcing (ZF) are proposed. Combining tools from inner approximation framework and Dinkelbach method, we develop simple iterative algorithms with polynomial computational complexity in each iteration and strong theoretical performance guaranteed. Furthermore, towards a robust design for FD CFmMIMO, a novel heap-based pilot assignment algorithm is proposed to mitigate effects of pilot contamination. Numerical results show that our proposed designs with realistic parameters significantly outperform the well-known approaches (i.e., smallcell and collocated mMIMO) in terms of the SE and EE. Notably, the proposed ZF designs require much less execution time than the simple maximum ratio transmission/combining. [less ▲]

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See detailMultiomics data integration unveils core transcriptional regulatory networks governing cell-type identity
Del Sol Mesa, Antonio UL

in NPJ systems biology and applications (2020)

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See detailVertical differentiation and trade among symmetric countries.
Picard, Pierre M UL; Tampieri, Alessandro

in Econometric Theory (2020)

We study a trade model with vertical product differentiation with many goods that are heterogeneous in cost and quality and produced in two quality versions. We discuss the composition of high- and low ... [more ▼]

We study a trade model with vertical product differentiation with many goods that are heterogeneous in cost and quality and produced in two quality versions. We discuss the composition of high- and low-quality goods in the workers’ consumption baskets in countries between comparable countries. We show that a larger country population fosters its specialization in high-quality production while a higher country productivity leads to specialization in high quality production for all countries. Smaller trade costs foster specialization in high quality exports. We then discuss the effect of population heterogeneity on the consumption baskets and country specialization. Most of those results agree with existing empirical findings. [less ▲]

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See detailStein’s method for multivariate Brownian approximations of sums under dependence
Kasprzak, Mikolaj UL

in Stochastic Processes and Their Applications (2020), 130(8), 4927-4967

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See detailOrthorectified Polar Format Algorithm for Generalized Spotlight SAR Imaging With DEM
Hu, Ruizhi UL; Rao, Bhavani Shankar Mysore Rama; Alaee-Kerahroodi, Mohammad et al

in IEEE Transactions on Geoscience and Remote Sensing (2020)

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See detailAccurate Many-Body Repulsive Potentials for Density-Functional Tight Binding from Deep Tensor Neural Networks
Stoehr, Martin UL; Medrano Sandonas, Leonardo UL; Tkatchenko, Alexandre UL

in Journal of Physical Chemistry Letters (2020), 11(16), 68356843

We combine density-functional tight binding (DFTB) with deep tensor neural networks (DTNN) to maximize the strengths of both approaches in predicting structural, energetic, and vibrational molecular ... [more ▼]

We combine density-functional tight binding (DFTB) with deep tensor neural networks (DTNN) to maximize the strengths of both approaches in predicting structural, energetic, and vibrational molecular properties. The DTNN is used to construct a nonlinear model for the localized many-body interatomic repulsive energy, which so far has been treated in an atom-pairwise manner in DFTB. Substantially improving upon standard DFTB and DTNN, the resulting DFTB-NNrep model yields accurate predictions of atomization and isomerization energies, equilibrium geometries, vibrational frequencies, and dihedral rotation profiles for a large variety of organic molecules compared to the hybrid DFT-PBE0 functional. Our results highlight the potential of combining semiempirical electronic-structure methods with physically motivated machine learning approaches for predicting localized many-body interactions. We conclude by discussing future advancements of the DFTB-NNrep approach that could enable chemically accurate electronic-structure calculations for systems with tens of thousands of atoms. [less ▲]

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See detailDevelopmental GABA polarity switch and neuronal plasticity in Bioengineered Neuronal Organoids
Zafeiriou, Maria-Patapia; Bao, Guobin; Hudson, James et al

in Nature Communications (2020), 11(1), 3791

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See detailUltrafast scanning calorimetry of newly developed Au-Ga bulk metallic glasses
Neuber, Nico; Frey, Maximilian; Gross, Oliver et al

in Journal of Physics: Condensed Matter (2020), 32(32), 324001

The isothermal crystallization times and critical cooling rates of the liquid phase are determined for the two bulk metallic glass forming alloys Au49Ag5.5Pd2.3Cu26.9Si16.3 and Au51.6Ag5.8Pd2.4Cu20.2Ga6 ... [more ▼]

The isothermal crystallization times and critical cooling rates of the liquid phase are determined for the two bulk metallic glass forming alloys Au49Ag5.5Pd2.3Cu26.9Si16.3 and Au51.6Ag5.8Pd2.4Cu20.2Ga6.7Si13.3 by using fast differential scanning calorimetry, covering the whole timescale of the crystallization event of the metallic melt. In the case of Au49Ag5.5Pd2.3Cu26.9Si16.3, a typical crystallization nose was observed, whereas for the Au51.6Ag5.8Pd2.4Cu20.2Ga6.7Si13.3, a more complex crystallization behavior with two distinct crystallization noses was found. Even for the complex crystallization behavior of the Au51.6Ag5.8Pd2.4Cu20.2Ga6.7Si13.3 alloy it is shown that the minimal isothermal nose time does allow for a quantification of the macroscopic critical thickness. It is discussed in contrast to the critical cooling rate, which is found to allow less exact calculations of the critical thickness and thus does not correlate well with the critical cooling rate from macroscopic experiments. Additionally the crystallization data of Au49Ag5.5Pd2.3Cu26.9Si16.3 was modeled using classical nucleation theory with the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation, enabling a determination of the interfacial energy. [less ▲]

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See detailPhagocytosis‐related NADPH oxidase 2 subunit gp91phox contributes to neurodegeneration after repeated systemic challenge with lipopolysaccharides
Shahraz, Anahita; Wißfeld, Jannis; Ginolhac, Aurélien UL et al

in Glia (2020)

Repeated systemic challenge with lipopolysaccharides (LPS) can induce microglia activation and inflammatory neurodegeneration in the substantia nigra pars compacta region of mice. We now explored the role ... [more ▼]

Repeated systemic challenge with lipopolysaccharides (LPS) can induce microglia activation and inflammatory neurodegeneration in the substantia nigra pars compacta region of mice. We now explored the role of mononuclear phagocytes associated nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX‐2) in inflammatory neurodegeneration. Cybb ‐deficient NOX‐2 knock‐out (KO) and control wild type (WT) mice were treated intraperitoneally daily over four consecutive days with 1 μg/gbw/day LPS. Transcriptome analysis by RNA‐seq of total brain tissue indicated increased LPS‐induced upregulation of genes belonging to the reactive oxygen species and reactive nitrogen species production, complement and lysosome activation as well as apoptosis and necroptosis in WT compared to NOX‐2 KO mice. Validation of up‐regulated gene transcripts via qRT‐PCR confirmed that LPS‐challenged NOX‐2 KO mice expressed lower levels of the microglial phagocytosis‐related genes Nos2 , Cd68 , Aif1/Iba1 , Cyba , Itgam , and Fcer1g compared to WT mice at Day 5 after systemic inflammatory challenge, but no significant differences in the pro‐inflammatory genes Tnfα and Il1b as well as microglial IBA1 and CD68 intensities were observed between both genotypes. Furthermore, loss of tyrosine hydroxylase positive (TH+) and NeuN positive neurons in the substantia nigra pars compacta upon repeated systemic LPS application were attenuated in NOX‐2 KO mice. Thus, our data demonstrate that loss of dopaminergic neurons in the substantia nigra pars compacta after repeated systemic challenge with LPS is associated with a microglial phagocytosis‐related gene activation profile involving the NADPH oxidase subunit Cybb/gp91phox. [less ▲]

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See detailResource Allocation for Energy Efficiency in OFDMA-Enabled WPCN
Nguyen, Tien-Tung; Pham, Quoc-Viet; Nguyen, van Dinh UL et al

in IEEE Wireless Communications Letters (2020), 9(12), 2049-2053

This letter considers a wireless powered communication network (WPCN), where an energy-constrained device directly uses harvested energy from a power transfer source to transmit independent signals to ... [more ▼]

This letter considers a wireless powered communication network (WPCN), where an energy-constrained device directly uses harvested energy from a power transfer source to transmit independent signals to multiple Internet of Things (IoT) users using orthogonal frequency division multiple access (OFDMA). Our goal is to maximize the system energy efficiency (EE) by jointly optimizing the duration of energy harvesting (EH), subcarrier and power allocation. The formulated problem is a mixed integer nonlinear programming (MINLP) problem due to the presence of binary assignment variables, and thus it is very challenging to solve it directly. By leveraging Dinkelbach method, a very efficient iterative algorithm with closed-form solutions in each iteration is developed, where its convergence is guaranteed. Numerical results show that the proposed algorithm obtains a fast convergence and outperforms baseline algorithms. Notably, they also reveal that the power source should transmit its maximum allowable power to obtain the optimal EE performance. [less ▲]

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See detailA framework to assess the quality and impact of bioinformatics training across ELIXIR.
Gurwitz, Kim T.; Singh Gaur, Prakash; Bellis, Louisa J. et al

in PLoS computational biology (2020), 16(7), 1007976

ELIXIR is a pan-European intergovernmental organisation for life science that aims to coordinate bioinformatics resources in a single infrastructure across Europe; bioinformatics training is central to ... [more ▼]

ELIXIR is a pan-European intergovernmental organisation for life science that aims to coordinate bioinformatics resources in a single infrastructure across Europe; bioinformatics training is central to its strategy, which aims to develop a training community that spans all ELIXIR member states. In an evidence-based approach for strengthening bioinformatics training programmes across Europe, the ELIXIR Training Platform, led by the ELIXIR EXCELERATE Quality and Impact Assessment Subtask in collaboration with the ELIXIR Training Coordinators Group, has implemented an assessment strategy to measure quality and impact of its entire training portfolio. Here, we present ELIXIR's framework for assessing training quality and impact, which includes the following: specifying assessment aims, determining what data to collect in order to address these aims, and our strategy for centralised data collection to allow for ELIXIR-wide analyses. In addition, we present an overview of the ELIXIR training data collected over the past 4 years. We highlight the importance of a coordinated and consistent data collection approach and the relevance of defining specific metrics and answer scales for consortium-wide analyses as well as for comparison of data across iterations of the same course. [less ▲]

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See detailFirst-principles description of the exciton-phonon interaction: A cumulant approach
Cudazzo, Pier Luigi UL

in Physical Review. B (2020), 102

Electron-phonon coupling leads to intriguing effects in the spectra of materials. Current approximations to calculate spectra most often describe this coupling insufficiently. Starting from basic ... [more ▼]

Electron-phonon coupling leads to intriguing effects in the spectra of materials. Current approximations to calculate spectra most often describe this coupling insufficiently. Starting from basic equations of many-body perturbation theory, we derived a cumulant formulation for neutral excitation spectra that contains excitonic effects and the coupling between excitons and phonons. The cumulant approach allows us to include dynamical effects arising from the electron-phonon coupling in a simple and intuitive way. It can be implemented as a postprocessing of state-of-the-art GW-plus-Bethe-Salpeter calculation of excitonic states and a density functional perturbation theory calculation of phonons and electron-phonon coupling. We demonstrate that, in order to obtain a consistent treatment of exciton-phonon coupling, diagrams have to be taken into account that can be neglected when the effect of lattice vibrations is treated in a static or quasistatic approximation. From the application of this approach to a model system, we analyzed the main features of the exciton-phonon interaction and provided a general picture of their link with the properties of materials such as exciton mass and exciton Bohr radius. [less ▲]

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See detailTrajectory Tracking for Aerial Robots: an Optimization-Based Planning and Control Approach
Sanchez Lopez, Jose Luis UL; Castillo Lopez, Manuel UL; Olivares Mendez, Miguel Angel UL et al

in Journal of Intelligent and Robotic Systems (2020), 100

In this work, we present an optimization-based trajectory tracking solution for multirotor aerial robots given a geometrically feasible path. A trajectory planner generates a minimum-time kinematically ... [more ▼]

In this work, we present an optimization-based trajectory tracking solution for multirotor aerial robots given a geometrically feasible path. A trajectory planner generates a minimum-time kinematically and dynamically feasible trajectory that includes not only standard restrictions such as continuity and limits on the trajectory, constraints in the waypoints, and maximum distance between the planned trajectory and the given path, but also restrictions in the actuators of the aerial robot based on its dynamic model, guaranteeing that the planned trajectory is achievable. Our novel compact multi-phase trajectory definition, as a set of two different kinds of polynomials, provides a higher semantic encoding of the trajectory, which allows calculating an optimal solution but following a predefined simple profile. A Model Predictive Controller ensures that the planned trajectory is tracked by the aerial robot with the smallest deviation. Its novel formulation takes as inputs all the magnitudes of the planned trajectory (i.e. position and heading, velocity, and acceleration) to generate the control commands, demonstrating through in-lab real flights an improvement of the tracking performance when compared with a controller that only uses the planned position and heading. To support our optimization-based solution, we discuss the most commonly used representations of orientations, as well as both the difference as well as the scalar error between two rotations, in both tridimensional and bidimensional spaces $SO(3)$ and $SO(2)$. We demonstrate that quaternions and error-quaternions have some advantages when compared to other formulations. [less ▲]

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See detailTeachers’ information processing and judgement accuracy: effects of information consistency and accountability
Pit-Ten Cate, Ineke UL; Hörstermann, Thomas UL; Krolak-Schwerdt, Sabine UL et al

in European Journal of Psychology of Education (2020), 35(3), 675-702

Research has shown that teachers are able to adapt their processing strategy of student information to situational demands, whereby they flexibly use either an automatic and category-based strategy or a ... [more ▼]

Research has shown that teachers are able to adapt their processing strategy of student information to situational demands, whereby they flexibly use either an automatic and category-based strategy or a controlled and information-integrating strategy. However, the effect of teachers’ accountability for task and the consistency of student information on strategy use is less clear. In two experimental studies, teachers were presented with consistent and inconsistent student profiles, whereby accountability levels were systematically varied. In the first study, the attention to and memory of information were investigated as indicators of changes in information processing strategy. In the second study, resulting changes in judgement accuracy were investigated. Results of study 1 provided support for the theoretical assumption that people apply the category-based strategy when confronted with consistent information under low accountability conditions, while inconsistent information and high accountability conditions led to the use of information-integration strategy. Results of study 2 showed that teachers’ judgement accuracy generally increased in relation to high accountability conditions and to lesser extent profile consistency, whereby inaccuracy reflected both under- and overestimation of student ability. The combined results suggest that the use of differential information processing strategies not only leads to differences in the attention to and processing of information, but also results in differences in the quality of judgements and decision making, especially under high accountability conditions. [less ▲]

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See detailLuxembourg Fund Data Repository
Skoura, Angeliki; Presber, Julian; Schiltz, Jang UL

in Data (2020), 5(3), 1-15

In this paper, we introduce the Luxembourg Fund Data Repository, a novel database of investment funds available for academic research that was created at the Department of Finance of the University of ... [more ▼]

In this paper, we introduce the Luxembourg Fund Data Repository, a novel database of investment funds available for academic research that was created at the Department of Finance of the University of Luxembourg. The database contains the population of Undertakings for Collective Investment in Transferable Securities funds domiciled in Luxembourg from the starting month of their existence (March 1988) to October 2016. The fund characteristics are organized in a comprehensive database architecture encompassing static and dynamic data over the entire life of the funds. The characteristics include fund identifiers, official name, status information, management company and other service providers, daily and monthly performance time-series, portfolio holdings, classification of investment objective, fees, dividends, and cash flows. The database was constructed after collecting and assembling complementary historical information from three data providers. Importantly, funds no longer in existence due to liquidation or mergers are included in the database, preventing survivorship bias. The database has been constructed to serve as a research dataset of high accuracy due to the maximization of population coverage, the maximization of historical coverage, and validation by using information acquired from the supervisory authority of the financial sector of Luxembourg. License currently available to researchers of the Department of Finance of the University of Luxembourg. Future plans for extending accessibility to the global academic community. [less ▲]

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See detailDistinct Cargos of Small Extracellular Vesicles Derived from Hypoxic Cells and Their Effect on Cancer Cells
Walbrecq, Geoffroy; Margue, Christiane UL; Behrmann, Iris UL et al

in International Journal of Molecular Sciences (2020)

Hypoxia is a common hallmark of solid tumors and is associated with aggressiveness, metastasis and poor outcome. Cancer cells under hypoxia undergo changes in metabolism and there is an intense crosstalk ... [more ▼]

Hypoxia is a common hallmark of solid tumors and is associated with aggressiveness, metastasis and poor outcome. Cancer cells under hypoxia undergo changes in metabolism and there is an intense crosstalk between cancer cells and cells from the tumor microenvironment. This cross talk is facilitated by small extracellular vesicles (sEVs; diameter between 30 and 200 nm), including exosomes and microvesicles, which carry a cargo of proteins, mRNA, ncRNA and other biological molecules. Hypoxia is known to increase secretion of sEVs and has an impact on the composition of the cargo. This sEV-mediated crosstalk ultimately leads to various biological effects in the proximal tumor microenvironment but also at distant, future metastatic sites. In this review, we discuss the changes induced by hypoxia on sEV secretion and their cargo as well as their effects on the behaviour and metabolism of cancer cells, the tumor microenvironment and metastatic events. [less ▲]

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See detailA comprehensive study on software aging across android versions and vendors
Iannillo, Antonio Ken UL; Cotroneo, Domenico; Natella, Roberto et al

in Empirical Software Engineering (2020)

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See detailGene regulatory network inference from sparsely sampled noisy data
Aalto, Atte UL; Viitasaari, Lauri; Ilmonen, Pauliina et al

in Nature Communications (2020), 11

The complexity of biological systems is encoded in gene regulatory networks. Unravelling this intricate web is a fundamental step in understanding the mechanisms of life and eventually developing ... [more ▼]

The complexity of biological systems is encoded in gene regulatory networks. Unravelling this intricate web is a fundamental step in understanding the mechanisms of life and eventually developing efficient therapies to treat and cure diseases. The major obstacle in inferring gene regulatory networks is the lack of data. While time series data are nowadays widely available, they are typically noisy, with low sampling frequency and overall small number of samples. This paper develops a method called BINGO to specifically deal with these issues. Benchmarked with both real and simulated time-series data covering many different gene regulatory networks, BINGO clearly and consistently outperforms state-of-the-art methods. The novelty of BINGO lies in a nonparametric approach featuring statistical sampling of continuous gene expression profiles. BINGO’s superior performance and ease of use, even by non-specialists, make gene regulatory network inference available to any researcher, helping to decipher the complex mechanisms of life. [less ▲]

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See detailIs evidence normative?
Hofmann, Frank UL

in Philosophia (2020)

This paper defends the view that in a certain sense evidence is normative. Neither a bit of evidence nor the fact that it is evidence for a certain proposition is a normative fact, but it is still the ... [more ▼]

This paper defends the view that in a certain sense evidence is normative. Neither a bit of evidence nor the fact that it is evidence for a certain proposition is a normative fact, but it is still the case that evidence provides normative reason for belief. An argument for the main thesis will be presented. It will rely on evidentialist norms of belief and a Broomean conception of normative reasons. Two important objections will be discussed, one from A. Steglich-Petersen on whether having evidence is sufficient for having a normative reason for belief and another one from S. Street. [less ▲]

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See detailA rare loss-of function variant of ADAM17 is associated with late-onset familial Alzheimer disease
Hartl, Daniela; May, Patrick UL; Gu, Wei UL et al

in Molecular Psychiatry (2020), 25(3), 629-639

Common variants of about 20 genes contributing to AD risk have so far been identified through genome-wide association studies (GWAS). However, there is still a large proportion of heritability that might ... [more ▼]

Common variants of about 20 genes contributing to AD risk have so far been identified through genome-wide association studies (GWAS). However, there is still a large proportion of heritability that might be explained by rare but functionally important variants. One of the so far identified genes with rare AD causing variants is ADAM10. Using whole-genome sequencing we now identified a single rare nonsynonymous variant (SNV) rs142946965 [p.R215I] in ADAM17 co-segregating with an autosomal-dominant pattern of late-onset AD in one family. Subsequent genotyping and analysis of available whole-exome sequencing data of additional case/control samples from Germany, the UK and the USA identified five variant carriers among AD patients only. The mutation inhibits pro-protein cleavage and the formation of the active enzyme, thus leading to loss-of-function of ADAM17 α-secretase. Further, we identified a strong negative correlation between ADAM17 and APP gene expression in human brain and present in vitro evidence that ADAM17 negatively controls the expression of APP. As a consequence, p.R215I mutation of ADAM17 leads to elevated Aß formation in vitro. Together our data supports a causative association of the identified ADAM17 variant in the pathogenesis of AD. [less ▲]

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See detailAssessment of the production of biodiesel from urban wastewater-derived lipids
Frkova, Zuzana UL; Venditti, Silvia UL; Patrick, Herr et al

in Resources, Conservation and Recycling (2020), 162

Production of biodiesel is one of the most important European targets within renewables for the future. To consider biodiesel a feasible alternative to fossil fuel, unconventional resources need to be ... [more ▼]

Production of biodiesel is one of the most important European targets within renewables for the future. To consider biodiesel a feasible alternative to fossil fuel, unconventional resources need to be exploited. This review aims to provide up-to-date knowledge on the existing reuse of lipids from urban wastewater to produce biodiesel. Lipids are readily removed by mixed microbial populations during wastewater treatments in sewage plants. Assessment results on potential annual European market supply indicate 3 – 414 104 tons (min for activated and max for grease trap sludge) of potentially extractable biodiesel from wastewater and an expected biodiesel demand of 14.8 106 tons. Considering the prospect of transforming sewage plants into biorefineries, we may cover on average 1.5, 6.2, 6.7 and 24.4% of activated, primary, scum and grease trap sludge respectively, of the European biodiesel market from wastewater-derived lipids. In addition, by implementing an optimized biotechnology selector, the overall biodiesel yield could be higher due to increased lipid incorporation into microbial biomass. This is not an insignificant amount and, if efficiently implemented, could represent an exploitable resource for biofuel production, an important and desired step towards a circular economy. The technology readiness level is still very low. There are several challenges and possible drawbacks, e.g., biogas yield loss, substrate depletion, or formation of floating sludge. Finally, no definitive legislative barriers towards wastewater-derived lipids have been identified; however, quality criteria as well as waste status have to be defined. [less ▲]

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See detailFine-grained Code Coverage Measurement in Automated Black-box Android Testing
Pilgun, Aleksandr UL; Gadyatskaya, Olga UL; Zhauniarovich, Yury et al

in ACM Transactions on Software Engineering and Methodology (2020), 29(4), 1-35

Today, there are millions of third-party Android applications. Some of them are buggy or even malicious. To identify such applications, novel frameworks for automated black-box testing and dynamic ... [more ▼]

Today, there are millions of third-party Android applications. Some of them are buggy or even malicious. To identify such applications, novel frameworks for automated black-box testing and dynamic analysis are being developed by the Android community. Code coverage is one of the most common metrics for evaluating effectiveness of these frameworks. Furthermore, code coverage is used as a fitness function for guiding evolutionary and fuzzy testing techniques. However, there are no reliable tools for measuring fine-grained code coverage in black-box Android app testing. We present the Android Code coVerage Tool, ACVTool for short, that instruments Android apps and measures code coverage in the black-box setting at class, method and instruction granularity. ACVTool has successfully instrumented 96.9% of apps in our experiments. It introduces a negligible instrumentation time overhead, and its runtime overhead is acceptable for automated testing tools. We demonstrate practical value of ACVTool in a large-scale experiment with Sapienz, a state-of-art automated testing tool. Using ACVTool on the same cohort of apps, we have compared different coverage granularities applied by Sapienz in terms of the found amount of crashes. Our results show that none of the applied coverage granularities clearly outperforms others in this aspect. [less ▲]

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See detailAbsorber composition: A critical parameter for the effectiveness of heat treatments in chalcopyrite solar cells
Sood, Mohit UL; Elanzeery, Hossam UL; Adeleye, Damilola UL et al

in Progress in Photovoltaics (2020)

Post-device heat treatment (HT) in chalcopyrite [Cu(In,Ga)(S,Se)2] solar cells is known to improve the performance of the devices. However, this HT is only beneficial for devices made with absorbers grown ... [more ▼]

Post-device heat treatment (HT) in chalcopyrite [Cu(In,Ga)(S,Se)2] solar cells is known to improve the performance of the devices. However, this HT is only beneficial for devices made with absorbers grown under Cu-poor conditions but not under Cu excess.. We present a systematic study to understand the effects of HT on CuInSe2 and CuInS2 solar cells. The study is performed for CuInSe2 solar cells grown under Cu-rich and Cu-poor chemical potential prepared with both CdS and Zn(O,S) buffer layers. In addition, we also study Cu-rich CuInS2 solar cells prepared with the suitable Zn(O,S) buffer layer. For Cu-poor selenide device low-temperature HT leads to passivation of bulk, whereas in Cu-rich devices no such passivation was observed. The Cu-rich devices are hampered by a large shunt. The HT decreases shunt resistance in Cu-rich selenides, whereas it increases shunt resistance in Cu-rich sulfides.. The origin of these changes in device performance was investigated with capacitance-voltage measurement which shows the considerable decrease in carrier concentration with HT in Cu-poor CuInSe2, and temperature dependent current-voltage measurements show the presence of barrier for minority carriers. Together with numerical simulations, these findings support a highly-doped interfacial p+ layer device model in Cu-rich selenide absorbers and explain the discrepancy between Cu-poor and Curich device performance. Our findings provide insights into how the same treatment can have a completely different effect on the device depending on the composition of the absorber. [less ▲]

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See detailWhen I Look into Your Eyes: A Survey on Computer Vision Contributions for Human Gaze Estimation and Tracking
Cazzato, Dario UL; Leo, Marco; Distante, Cosimo et al

in Sensors (2020), 20(13), 3739

The automatic detection of eye positions, their temporal consistency, and their mapping into a line of sight in the real world (to find where a person is looking at) is reported in the scientific ... [more ▼]

The automatic detection of eye positions, their temporal consistency, and their mapping into a line of sight in the real world (to find where a person is looking at) is reported in the scientific literature as gaze tracking. This has become a very hot topic in the field of computer vision during the last decades, with a surprising and continuously growing number of application fields. A very long journey has been made from the first pioneering works, and this continuous search for more accurate solutions process has been further boosted in the last decade when deep neural networks have revolutionized the whole machine learning area, and gaze tracking as well. In this arena, it is being increasingly useful to find guidance through survey/review articles collecting most relevant works and putting clear pros and cons of existing techniques, also by introducing a precise taxonomy. This kind of manuscripts allows researchers and technicians to choose the better way to move towards their application or scientific goals. In the literature, there exist holistic and specifically technological survey documents (even if not updated), but, unfortunately, there is not an overview discussing how the great advancements in computer vision have impacted gaze tracking. Thus, this work represents an attempt to fill this gap, also introducing a wider point of view that brings to a new taxonomy (extending the consolidated ones) by considering gaze tracking as a more exhaustive task that aims at estimating gaze target from different perspectives: from the eye of the beholder (first-person view), from an external camera framing the beholder’s, from a third-person view looking at the scene where the beholder is placed in, and from an external view independent from the beholder. [less ▲]

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See detailIndustrial demand-side flexibility: A key element of a just energy transition and industrial development
Heffron, Raphael; Körner, Marc-Fabian; Wagner, Jonathan et al

in Applied Energy (2020)

In many countries, industry is one of the largest consumers of electricity. Given the special importance of electricity for industry, a reliable electricity supply is a basic prerequisite for further ... [more ▼]

In many countries, industry is one of the largest consumers of electricity. Given the special importance of electricity for industry, a reliable electricity supply is a basic prerequisite for further industrial development and associated economic growth. As countries worldwide transition to a low-carbon economy (in particular, by the development of renewable energy sources), the increasing fluctuation in renewable energy production requires new flexibility options within the electricity system in order to guarantee security of supply. It is advanced in this paper that such a flexibility transition with an active participation of industry in general has unique potential: It will not only promote green industrial development, but also become an engine for inclusive industrial development and growth as well as delivering a just transition to a low-carbon economy. Given the high potential of industrial demand-side flexibility, a first monitoring approach for such a flexibility transition is illustrated, which bases on a flexibility index. Our flexibility index allows for an indication of mis-developments and supports an appropriate implementation of countermeasures together with relevant stakeholders. Hence, it holds various insights for both policy-makers and practice with respect to how industrial demand-side flexibility can ensure advances towards an inclusive, just, and sustainable industrial development. [less ▲]

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See detailPhysical Activity Behavior of Children and Adolescents in Luxembourg - An Accelerometer-based Study
Eckelt, Melanie UL; Hutmacher, Djenna UL; Steffgen, Georges UL et al

in Journal of Physical Activity Research (2020), 5(1), 23-28

Due to the continuous decrease of physical activity of children in industrialized countries physical activity behavior has become a key issue in health-related research. The purpose of this study was to ... [more ▼]

Due to the continuous decrease of physical activity of children in industrialized countries physical activity behavior has become a key issue in health-related research. The purpose of this study was to assess objectively the daily physical activity of Luxembourgish children and adolescents and its distribution into school and leisure time. The physical activity behavior of 242 students (108 male students, 134 female students) with an average age of 12.84 years (SD = 2.37) was objectively assessed by wearing an accelerometer (ActiGraph GT3X-BT) for seven consecutive days. The average daily time spent in moderate to vigorous physical activity was 47.75 minutes (SD = 19.75). 62 students accumulated the recommended 60 minutes per day. 32% of students’ total moderate to vigorous physical activity occurred during school time and 63% during leisure time. During physical education, students were engaged in moderate to vigorous physical activity on average for 20.02%, whereas 46.93% of the time was spent being sedentary. Significant gender differences were found for all variables in favor of male students. Equally, physical activity in all areas decreased significantly with age. The Luxembourgish children and adolescents are insufficient physically active and the moderate to vigorous physical activity levels are mainly accounted by leisure time. Therefore, it seems reasonable for schools to create an environment that supports the physical activity throughout the school day to increase the daily physical activity, with special attention to female and older students. [less ▲]

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See detailGeneralized quasicontinuum modeling of metallic lattices with geometrical and material nonlinearity and variability
Chen, Li UL; Beex, Lars UL; Berke, Peter et al

in Computer Methods in Applied Mechanics and Engineering (2020), 366(112878),

We propose a generalized quasicontinuum method to model the mechanical response of 3D lattice structures. The method relies on the spatial coupling of fully-resolved domains and coarse-grained domains. In ... [more ▼]

We propose a generalized quasicontinuum method to model the mechanical response of 3D lattice structures. The method relies on the spatial coupling of fully-resolved domains and coarse-grained domains. In the fully-resolved domain, the full micro-structure is taken into account. In the coarse-grained domain, the kinematics of the micro-structure are individually interpolated based on their connectivity. On top of that, the contributions of the microstructure to the governing equations in the coarse-grained domain are sampled using only a few unit cells. In both domains, geometrical and material variability along the strut can be naturally taken into account using a 3D co-rotational beam finite element with embedded plastic hinges. We verify the approach for BCC lattices, demonstrating that the new method can capture both material and geometrical non-linearities of single struts at a fraction of the cost of a direct numerical simulation. [less ▲]

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See detailL'Europe au miroir quasi-cristallin. Sur le besoin juridique du vertige littéraire
Becker, Katrin UL

in Révue Droit & Littérature (2020), 4

L’article prend comme point de départ l’anthropologie dogmatique du philosophe et historien du droit Pierre Legendre, et met en lumière les imbrications du droit et de la littérature, plus spécifiquement ... [more ▼]

L’article prend comme point de départ l’anthropologie dogmatique du philosophe et historien du droit Pierre Legendre, et met en lumière les imbrications du droit et de la littérature, plus spécifiquement l’importance de la littérature pour la relation du sujet au droit. Un rôle central joue ici la logique de la représentation – qui s’avère essentielle pour assurer la validité du système juridique ainsi que l’adhésion du sujet aux données normatives d’un système culturel : Pour chaque culture il s’agit de créer une construction du face à face avec le monde, une représentation – textuelle et imaginaire – dans laquelle le sujet se reconnaît et à laquelle il peut croire. Allant au-delà de l’approche legendrienne, notre article posera l’hypothèse que c’est notamment le texte littéraire qui, grâce au pouvoir fictionnel inhérent à sa structure spéculaire, se montre capable de créer, d’affirmer ou de bouleverser un système représentationnel. Ensuite, nous allons interroger l’hypothèse du lien représentationnel entre sujet et droit sous les conditions actuelles (mondialisation, multilinguisme, numérisation), avant d’examiner sa validité dans le contexte européen : Un système commun européen de représentation, existe-t-il véritablement ? Une littérature européenne pourrait-elle aider à le ressusciter ou bien à en construire un ? Et enfin, compte tenu de la diversité de langues et des nationalismes renaissants, à quoi pourrait ressembler une « littérature européenne »? Dans le but d’esquisser une réponse à ces questions, l’article va examiner les données représentationnelles du système politico-juridico-culturel européen afin d’ensuite tracer les contours d’une littérature européenne et de déceler comment celle-ci pourrait contribuer à la mise en place d’un miroir commun de la communauté européenne. [less ▲]

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See detailAn infographic synopsis of Luxembourg’s Food System
Reckinger, Rachel UL; Kapgen, Diane UL; Korjonen, Maria Helena UL

in Forum für Politik, Gesellschaft und Kultur in Luxemburg (2020), 408

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See detailDiversität im UX-Design: Mehr Vielfalt für bessere Experience
Rohles, Björn UL

in t3n – Digital Pioneers (2020), (60), 170-173

In a connected world, target audiences are more diverse than ever before. In UX design, this complexity is a major challenge. However, the right tools allow creating digital services and products that ... [more ▼]

In a connected world, target audiences are more diverse than ever before. In UX design, this complexity is a major challenge. However, the right tools allow creating digital services and products that stand out positively from the rest. [less ▲]

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See detailStichwort Ernährungsdemokratie. Ein Ernährungsrat auf nationaler Ebene als greifbares Konzept für Luxemburg
Reckinger, Rachel UL; Schneider, Norry

in Forum für Politik, Gesellschaft und Kultur in Luxemburg (2020), 408

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See detailTransparency by Design in Data-Informed Research: a Collection of Information Design Patterns
Rossi, Arianna UL; Lenzini, Gabriele UL

in Computer Law and Security Review (2020), 37(105402),

Oftentimes information disclosures describing personal data-gathering research activities are so poorly designed that participants fail to be informed and blindly agree to the terms, without grasping the ... [more ▼]

Oftentimes information disclosures describing personal data-gathering research activities are so poorly designed that participants fail to be informed and blindly agree to the terms, without grasping the rights they can exercise and the risks derived from their cooperation. To respond to the challenge, this article presents a series of operational strategies for transparent communication in line with legal-ethical requirements. These "transparency-enhancing design patterns" can be implemented by data controllers/researchers to maximize the clarity, navigability, and noticeability of the information provided and ultimately empower data subjects/research subjects to appreciate and determine the permissible use of their data. [less ▲]

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See detailBeam Illumination Pattern Design in Satellite Networks: Learning and Optimization for Efficient Beam Hopping
Lei, Lei UL; Lagunas, Eva UL; Yuan, Yaxiong UL et al

in IEEE Access (2020)

Beam hopping (BH) is considered to provide a high level of flexibility to manage irregular and time-varying traffic requests in future multi-beam satellite systems. In BH optimization, adopting ... [more ▼]

Beam hopping (BH) is considered to provide a high level of flexibility to manage irregular and time-varying traffic requests in future multi-beam satellite systems. In BH optimization, adopting conventional iterative heuristics may have their own limitations in providing timely solutions, and directly using data-driven technique to approximate optimization variables may lead to constraint violation and degraded performance. In this paper, we explore a combined learning-and-optimization (L&O) approach to provide an efficient, feasible, and near-optimal solution. The investigations are from the following aspects: 1) Integration ofBH optimization and learning techniques; 2) Features to be learned in BH design; 3) How to address the feasibility issue incurred by machine learning. We provide numerical results and analysis to show that the learning component in L&O significantly accelerates the procedure of identifying promising BH patterns, resulting in reduced computing time from seconds/minutes to milliseconds level. The identified learning feature enables high accuracy in predictions. In addition, the optimization component in L&O guarantees the solution’s feasibility and improves the overall performance with around 5% gap to the optimum. [less ▲]

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See detailFood Sovereignty and Resilience in Luxembourg
Reckinger, Rachel UL

in Forum für Politik, Gesellschaft und Kultur in Luxemburg (2020), 408

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See detailExploring the 20-year evolution of a research community: web-archives as essential sources for historical research
Brügger, Niels; Schafer, Valerie UL; Geeraert, Friedel et al

in Cahiers de la documentation (2020), 2

Le projet PROMISE ne pouvait se concevoir sans aborder la question de l’accès aux archives du web belge. En effet, s’il est important de les sauvegarder, c’est en raison de leur importance comme sources ... [more ▼]

Le projet PROMISE ne pouvait se concevoir sans aborder la question de l’accès aux archives du web belge. En effet, s’il est important de les sauvegarder, c’est en raison de leur importance comme sources d’information pour la recherche. Par conséquent, lors du colloque “Saving the Web: the Promise of a Belgian Web Archive”, l’accès et l’utilisation de ces archives spécifiques ont été largement abordés. Deux des intervenants lors de ce colloque, Valérie Schafer et Niels Brügger, ont accepté de partager leurs expériences respectives quant à l’utilisation d’archives web, celles-ci remontant parfois au début des années 2000. [less ▲]

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