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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 detailNetworked Governance and Multistakeholder Cooperation
Bouillard, Maxime; van Weyenbergh, Gaël; Schafer, Valerie UL et al

Presentation (2020, September 08)

At the crossroads of three topics of the workshop (Critical testimonies on the implementation or experiments with new modes of governance; Presentation and analysis of online decision-making tools ... [more ▼]

At the crossroads of three topics of the workshop (Critical testimonies on the implementation or experiments with new modes of governance; Presentation and analysis of online decision-making tools; Prospective outlook on the governance of knowledge and research infrastructures), this presentation allows us to discuss how to increase multistakeholder cooperation between scientists and other stakeholders in practice and to gather perspectives from different cultural backgrounds into the discussion. [less ▲]

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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 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 detailInvestigation of condensation process inside inclined tube
Zhang, Yu UL

Doctoral thesis (2020)

Generation III+ reactor designs partially rely on passive safety systems. It aims to increase the plant safety standards and to reduce investment costs. Passive Decay Heat Removal Systems, such as the ... [more ▼]

Generation III+ reactor designs partially rely on passive safety systems. It aims to increase the plant safety standards and to reduce investment costs. Passive Decay Heat Removal Systems, such as the Emergency Condenser (EC) of the KERENA reactor design, plays an important role in the safety in nuclear power plants. As part of the emergency cooling chain, EC removes the decay heat from the reactor pressure vessel and transfers it to the flooding pool. For the successful design of the EC, the reliable prediction of the condensation heat transfer inside inclined pipes is one of the important factors. One-dimensional (1D) codes, such as ATHLET, RELAP and TRACE, are widely used today by engineers to predict the thermal hydraulic behavior of the system in nuclear power plant. However, state-of-the-art 1D codes are mainly validated for active components, and the qualification of passive systems is still a remaining problem. The goal of this thesis therefore is to investigate the condensation phenomena in EC using current advanced 1D code ATHLET (Analysis of Thermal-hydraulics of Leaks and Transients). The performance of ATHLET for prediction of condensation in slightly inclined tube was assessed and the results showed that the standard models in ATHLET code have significant deficiencies on the prediction of the condensation heat transfer coefficients. Thus, the new empirical model has been derived using experimental data from COSMEA (COndenSation test rig for flow Morphology and hEAt transfer studies) tests, condensation experiments for flow morphology and heat transfer studies in a single slightly inclined tube conducted by HZDR (Helmholtz-Zentrum Dresden-Rossendorf) and data sourced from literature. The new model was developed using Machine Learning – Regression Analysis methodology in MATLAB, which consists of upper liquid film condensation and bottom convective condensation. It was further implemented in ATHLET with Python programming language and the modified ATHLET code was used to calculate the COSMEA experiments. The post-calculation results were compared to experiments in three aspects: heat flux, condensation rate and void fraction along the whole pipe. The outcomes showed that the modified ATHLET code can be used to recalculate the relevant heat transfer values of experiments under different pressure and mass flow rate conditions. [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 detailTrace-Checking Signal-based Temporal Properties: A Model-Driven Approach
Boufaied, Chaima UL; Menghi, Claudio UL; Bianculli, Domenico UL et al

in Proceedings of the 35th IEEE/ACM International Conference on Automated Software Engineering (ASE ’20) (2020, September)

Signal-based temporal properties (SBTPs) characterize the behavior of a system when its inputs and outputs are signals over time; they are very common for the requirements specification of cyber-physical ... [more ▼]

Signal-based temporal properties (SBTPs) characterize the behavior of a system when its inputs and outputs are signals over time; they are very common for the requirements specification of cyber-physical systems. Although there exist several specification languages for expressing SBTPs, such languages either do not easily allow the specification of important types of properties (such as spike or oscillatory behaviors), or are not supported by (efficient) trace-checking procedures. In this paper, we propose SB-TemPsy, a novel model-driven trace-checking approach for SBTPs. SB-TemPsy provides (i) SB-TemPsy-DSL, a domain-specific language that allows the specification of SBTPs covering the most frequent requirement types in cyber-physical systems, and (ii) SB-TemPsy-Check, an efficient, model-driven trace-checking procedure. This procedure reduces the problem of checking an SB-TemPsy-DSL property over an execution trace to the problem of evaluating an Object Constraint Language constraint on a model of the execution trace. We evaluated our contributions by assessing the expressiveness of SB-TemPsy-DSL and the applicability of SB-TemPsy-Check using a representative industrial case study in the satellite domain. SB-TemPsy-DSL could express 97% of the requirements of our case study and SB-TemPsy-Check yielded a trace-checking verdict in 87% of the cases, with an average checking time of 48.7 s. From a practical standpoint and compared to state-of-the-art alternatives, our approach strikes a better trade-off between expressiveness and performance as it supports a large set of property types that can be checked, in most cases, within practical time limits. [less ▲]

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See detailDie Deutschordenskommende in der Stadt Luxemburg im 14. und 15. Jahrhundert
Pauly, Michel UL

in Sarnowsky, Jürgen (Ed.) Studies on the Military Orders, Prussia, and Urban History: Essays in honour of Roman Czaja on the occasion of his sixtieth birthday. Beiträge zur Ritterordens-, Preussen- und Städteforschung. Festschrift für Roman Czaja zum 60. Geburtstag (2020)

Geschichte der Niederlassung des Deutschen Ordens in der Stadt Luxemburg im 14. und 15. Jh., insbesondere ihres Besitzes und ihrer Einkünfte anhand des Zionsregisters von 1457-58

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See detail"Afrika beklauen"
Eilers, Dorte Lena; Dembele, Zonatan; Nonoa, Koku Gnatuloma UL

in Theater der Zeit (2020), (9), 30-32

Vor zehn Jahren starb Christoph Schlingensief und hinterließ der Welt seine letzte große Vision: das Operndorf Afrika. Ein Gespräch mit Zonatan Dembele und Koku G. Nonoa von Zonatan Dembele, Dorte Lena ... [more ▼]

Vor zehn Jahren starb Christoph Schlingensief und hinterließ der Welt seine letzte große Vision: das Operndorf Afrika. Ein Gespräch mit Zonatan Dembele und Koku G. Nonoa von Zonatan Dembele, Dorte Lena Eilers und Koku G. Nonoa [less ▲]

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See detailDer Arbeitsmarkt der Sozialen Arbeit 2019 = Le marché de l'emploi du secteur social en 2019
Böwen, Petra UL; Flammang, Manou Laure UL

E-print/Working paper (2020)

This newsletter describes the job market in the social work sector in Luxembourg in 2019. The data are derived from an ongoing research project by the PraxisBüro of the University of Luxembourg. The ... [more ▼]

This newsletter describes the job market in the social work sector in Luxembourg in 2019. The data are derived from an ongoing research project by the PraxisBüro of the University of Luxembourg. The newsletter presents a selection of statistics concerning for example the most sought after qualification levels, the distribution of practice fields, the distribution of job offers on public, municipal, privat an non-governmental organisations an the documented gab between the demand of social workers with a Bachelor diploma and the number of Bachelor diplomas issued in Luxembourg [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 - Hydrosphere (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 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 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 detailSmart Electrical and Thermal Energy Supply for Nearly Zero Energy Buildings
Rafii-Tabrizi, Sasan UL

Doctoral thesis (2020)

The European Union (EU) intends to reduce the greenhouse gas emissions to 80-95 % below 1990 levels by 2050. To achieve this goal, the EU focuses on higher energy efficiency mainly within the building ... [more ▼]

The European Union (EU) intends to reduce the greenhouse gas emissions to 80-95 % below 1990 levels by 2050. To achieve this goal, the EU focuses on higher energy efficiency mainly within the building sector and a share of renewable energy sources (RES) of around 30 % in gross final energy consumption by 2030. In this context, the concept of nearly zero-energy buildings (nZEB) is both an emerging and relevant research area. Balancing energy consumption with on-site renewable energy production in a cost-effective manner requires to develop suitable energy management systems (EMS) using demandside management strategies. This thesis develops an EMS using certainty equivalent (CE) economic model predictive control (EMPC) to optimally operate the building energy system with respect to varying electricity prices. The proposed framework is a comprehensive mixed integer linear programming model that uses suitable linearised grey box models and purely data-driven model approaches to describe the system dynamics. For this purpose, a laboratory prototype is available, which is capable of covering most building-relevant types of energy, namely thermal and electrical energy. Thermal energy for space heating, space cooling and domestic hot water is buffered in thermal energy storage systems. A dual source heat pump provides thermal energy for space heating and domestic hot water, whereas an underground ice storage covers space cooling. The environmental energy sources of the heat pump are ice storage or wind infrared sensitive collectors. The collectors are further used to regenerate the ice storage. Photovoltaic panels produce electrical energy which can be stored in a battery storage system. The electrical energy system is capable of selling and buying electricity from the public power grid. The laboratory test bench interacts with a virtual building model which is integrated into the building simulation software TRNSYS Simulation Studio. The EMS prototype is tested and validated on the basis of various simulations and under close to real-life laboratory conditions. The different test scenarios are generated using the typical day approach for each season. [less ▲]

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See detailAnaerobe Vergärung von (synthetischem) Küchenabfall in zweistufigem Semi-Konti-Betrieb
Sobon, Elena UL; Schlienz, Markus UL; Greger, Manfred UL

in Chemie Ingenieur Technik (2020, August 28), 92(9), 1267-1268

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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; X.Vu, Thang; 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 detailDecomposition schemes for symmetric n-ary bands
Devillet, Jimmy UL; Mathonet, Pierre

Scientific Conference (2020, August 27)

We extend the classical (strong) semilattice decomposition scheme of certain classes of semigroups to the class of idempotent symmetric n-ary semigroups (i.e. symmetric n-ary bands) where n \geq 2 is an ... [more ▼]

We extend the classical (strong) semilattice decomposition scheme of certain classes of semigroups to the class of idempotent symmetric n-ary semigroups (i.e. symmetric n-ary bands) where n \geq 2 is an integer. More precisely, we show that these semigroups are exactly the strong n-ary semilattices of n-ary extensions of Abelian groups whose exponents divide n-1. We then use this main result to obtain necessary and sufficient conditions for a symmetric n-ary band to be reducible to a semigroup. [less ▲]

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