References of "Scientific congresses, symposiums and conference proceedings"
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See detailImmersive Telepresence Framework for Remote Educational Scenarios
Botev, Jean UL; Rodríguez Lera, Francisco J.

in Proceedings of the 22nd International Conference on Human-Computer Interaction (HCI International) (in press)

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See detailProcess analysis in thermal process engineering with high-performance computing using the example of grate firing
Peters, Bernhard UL; Rousset, Alban UL; Besseron, Xavier UL et al

in Process analysis in thermal process engineering with high- performance computing using the example of grate firing (in press)

Biomass as a renewable energy source continues to grow in popularity to reduce fossil fuel consumption for environmental and economic benefits. In the present contribution, the combustion chamber of a 16 ... [more ▼]

Biomass as a renewable energy source continues to grow in popularity to reduce fossil fuel consumption for environmental and economic benefits. In the present contribution, the combustion chamber of a 16 MW geothermal steam super-heater, which is part of the Enel Green Power "Cornia 2" power plant, is being investigated with high-performance computing methods. For this purpose, the extended discrete element method (XDEM) developed at the University of Luxembourg is used in a high-performance computing environment, which includes both the moving wooden bed and the combustion chamber above it. The XDEM simulation platform is based on a hybrid four-way coupling between the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). In this approach, particles are treated as discrete elements that are coupled by heat, mass, and momentum transfer to the surrounding gas as a continuous phase. For individual wood particles, besides the equations of motion, the differential conservation equations for mass, heat, and momentum are solved, which describe the thermodynamic state during thermal conversion. The consistency of the numerical results with the actual system performance is discussed in this paper to determine the potentials and limitations of the approach. [less ▲]

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See detailWhich Properties has an Icon? A Critical Discussion on Evaluation Methods for Standardised Data Protection Iconography
Rossi, Arianna UL; Lenzini, Gabriele UL

in Proceedings of the 8th Workshop on Socio-Technical Aspects in Security and Trust (STAST) (in press)

Following GDPR's Article12.7's proposal to use standardized icons to inform data subject in "an easily visible, intelligible and clearly legible manner," several icon sets have been developed. In this ... [more ▼]

Following GDPR's Article12.7's proposal to use standardized icons to inform data subject in "an easily visible, intelligible and clearly legible manner," several icon sets have been developed. In this paper, we firstly critically review some of those proposals. We then examine the properties that icons and icon sets should arguably fulfill according to Art.12's transparency provisions. Lastly, we discuss metrics and evaluation procedures to measure compliance with the Article. [less ▲]

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See detailL’exposition d’objets ou de collections de « marque » : cobranding, réécriture, réénonciation
Schall, Céline UL

in Laval, Sylvie (Ed.) Marques muséales : un espace public revisité ? (in press)

Le cobranding est une pratique habituelle du secteur marchand. Mais lorsque deux musées réalisent ensemble une exposition, peut-on parler de cobranding muséal ? Quelles en seraient les spécificités  ... [more ▼]

Le cobranding est une pratique habituelle du secteur marchand. Mais lorsque deux musées réalisent ensemble une exposition, peut-on parler de cobranding muséal ? Quelles en seraient les spécificités ? Quels effets peut avoir cette démarche sur la communication ou sur l’exposition ? Notamment, le musée d’accueil s’approprie-t-il simplement l’imaginaire et les valeurs de la marque invitée par un phénomène de « transfert » ? Pour répondre à ces questions, nous étudions trois expositions qui reprennent des objets ou collections de musées dont la marque est internationalement reconnue. L’analyse sémiotique des images de marque du musée d’accueil et du musée invité ainsi que l’analyse sémiopragmatique des expositions montrent l’impact de la présence d’une grande marque internationale sur l’exposition et réciproquement, l’impact de l’exposition sur l’image de marque du musée d’accueil. Plus qu’un simple cobranding, c’est une réécriture impliquant une réénonciation du discours et des valeurs portés par les marques qui est proposée à travers ces expositions. Le processus aboutit à la création de nouveaux espaces symboliques et d’expositions réflexives, avec plusieurs niveaux de lecture. [less ▲]

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See detailThe Higher-Order Prover Leo-III (Highlight paper)
Steen, Alexander UL; Benzmüller, Christoph UL

in Proceedings of the 24th European Conference on Artificial Intelligence (in press)

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See detailA Methodology for Handling Data Movements by Anticipation: Position Paper
Bleuse, Raphaël UL; Lucarelli, Giorgio; Trystram, Denis

in Euro-Par 2018 Workshops (in press)

The enhanced capabilities of large scale parallel and distributed platforms produce a continuously increasing amount of data which have to be stored, exchanged and used by various tasks allocated on ... [more ▼]

The enhanced capabilities of large scale parallel and distributed platforms produce a continuously increasing amount of data which have to be stored, exchanged and used by various tasks allocated on different nodes of the system. The management of such a huge communication demand is crucial for reaching the best possible performance of the system. Meanwhile, we have to deal with more interferences as the trend is to use a single all-purpose interconnection network whatever the interconnect (tree-based hierarchies or topology-based heterarchies). There are two different types of communications, namely, the flows induced by data exchanges during the computations, and the flows related to Input/Output operations. We propose in this paper a general model for interference-aware scheduling, where explicit communications are replaced by external topological constraints. Specifically, the interferences of both communication types are reduced by adding geometric constraints on the allocation of tasks into machines. The proposed constraints reduce implicitly the data movements by restricting the set of possible allocations for each task. This methodology has been proved to be efficient in a recent study for a restricted interconnection network (a line/ring of processors which is an intermediate between a tree and higher dimensions grids/torus). The obtained results illustrated well the difficulty of the problem even on simple topologies, but also provided a pragmatic greedy solution, which was assessed to be efficient by simulations. We are currently extending this solution for more complex topologies. This work is a position paper which describes the methodology, it does not focus on the solving part. [less ▲]

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See detailLe dialogue entre les juges en matière de protection des droits de l'homme
Pelin Raducu, Ioana UL

in Menetrey, Séverine; Hess, Burkhard (Eds.) Les dialogues des juges en Europe (in press)

Dans cet article, nous allons mettre en exergue quelques aspects des arrêts récents provenant de la Cour de justice de l’UE (Akerberg Frasson, Melloni, Kamberaj)qui démontrent l’émergence d’un standard ... [more ▼]

Dans cet article, nous allons mettre en exergue quelques aspects des arrêts récents provenant de la Cour de justice de l’UE (Akerberg Frasson, Melloni, Kamberaj)qui démontrent l’émergence d’un standard propre de l’UE en matière des droits de l’homme. Cette tendance de la C.J.U.E. contredira le prescrit normatif découlant du « dialogue des juges » d’interprétation conforme à la jurisprudence de la C.E.D.H. avant que l’adhésion de l’UE à la Convention E.D.H. ne soit formellement acquise. [less ▲]

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See detailExternalisation de la politique migratoire et identité de l'Union européenne
Neframi, Eleftheria UL; Gatti, Mauro UL

in Benlolo, Myriam (Ed.) L'Union européenne et les migrations (in press)

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See detailUsing Passive Data Collection Methods to Learn Complex Mobility Patterns: An Exploratory Analysis
Toader, Bogdan UL; Cantelmo, Guido UL; Popescu, Mioara et al

Scientific Conference (in press)

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See detailMind the gap: Robotic Mission Planning Meets Software Engineering
Askarpour, Mehrnoosh; Menghi, Claudio UL; Belli, Gabriele et al

in Proceedings of the 8th International Conference on Formal Methods in Software Engineering (in press)

In the context of robotic software, the selection of an appropriate planner is one of the most crucial software engineering decisions. Robot planners aim at computing plans (i.e., blueprint of actions) to ... [more ▼]

In the context of robotic software, the selection of an appropriate planner is one of the most crucial software engineering decisions. Robot planners aim at computing plans (i.e., blueprint of actions) to accomplish a complex mission. While many planners have been proposed in the robotics literature, they are usually evaluated on showcase examples, making hard to understand whether they can be effectively (re)used for realising complex missions, with heterogeneous robots, and in real-world scenarios. In this paper we propose ENFORCE, a framework which allows wrapping FM-based planners into comprehensive software engineering tools, and considers complex robotic missions. ENFORCE relies on (i) realistic maps (e.g, fire escape maps) that describe the environment in which the robots are deployed; (ii) temporal logic for mission specification; and (iii) Uppaal model checker to compute plans that satisfy mission specifications. We evaluated ENFORCE by analyzing how it supports computing plans in real case scenarios, and by evaluating the generated plans in simulated and real environments. The results show that while ENFORCE is adequate for handling single-robot applications, the state explosion still represents a major barrier for reusing existing planners in multi-robot applications. [less ▲]

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See detailLes archevêques de Milan face aux premières expériences seigneuriales: stratégies et positionnements (milieu XIIIe-début XIVe s.)
Salemme, Timothy UL

in Barralis, Christine (Ed.) L’évêque face à son métier. Actes du colloque international, Metz. 15-17 novembre 2017 (in press)

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See detail« … Eripuit servus mihi vitam » - Représentations médiatiques de la violence et de la criminalité dans les provinces occidentales de l'Empire romain
Binsfeld, Andrea UL

in Amodio, Mara (Ed.) The imagery of violence in Roman society (I-VI cent.). Persistence, innovations and interrelations from the Roman to the Christian Empire (in press)

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See detailDatenbank für Zweisprachige Historische Luxemburgische Bekanntmachungen
Gilles, Peter UL; Ziegler, Evelyn

in Wallmeier, Nadine; Tophinke, Doris (Eds.) Historische Stadtsprachenforschung (in press)

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See detailA New Perspective on the Luxembourgish Genitive
Döhmer, Caroline UL

in Germanic Genitives (in press)

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See detailHistorical outline and chromatic properties of purpura rubra Tarentina and its potential identification with purple dye extracted from Bolinus brandaris
Meiers, Fabienne UL

in Enegren, Hedvig; Meo, Francesco (Eds.) Treasures from the Sea : Sea-Silk and Shell purple dye in antiquity. Proceedings from the International workshop, 26.-28.05. (in press)

This paper presents a historical overview of the importance of the red dye found in spiny dye-murices (Bolinus brandaris) and its production in Taranto, one of the most industrious Greek colonies founded ... [more ▼]

This paper presents a historical overview of the importance of the red dye found in spiny dye-murices (Bolinus brandaris) and its production in Taranto, one of the most industrious Greek colonies founded in southern Italy in the 8th century BC and renowned for its luxury products. Written evidence as well as numismatic and archaeological sources dating from the 5th century BC to the 5th century AD have been analysed in this context to identify purpura rubra Tarentina. In addition, the results of a series of dye experiments with hypobranchial glands from the same species are treated in order to detect chromatic properties and potential manufacturing processes for Tarentine Red. The methods for vatting the dye glands are discussed in relation to historical validity and chromatic outcome. To conclude, comparisons are drawn between the colour characteristics of Bolinus brandaris and Hexaplex trunculus (banded dye-murex), and the possibility of mixing both dyes is taken into consideration. The synthesis of historical and experimental approach finally shows that purpura rubra Tarentina can potentially be identified with purple dye extracted from Bolinus brandaris. [less ▲]

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See detailLe quotidien d’un poilu de la première guerre mondiale sur Facebook : nouvelle forme de médiation, nouvelle expérience ?
Schall, Céline UL; Vilatte, Jean-Christophe

in Les mondes de la médiation culturelle (in press)

« En 2013, le Musée de la Grande Guerre du Pays de Meaux et l’agence de communication DDB ont élaboré une page Facebook d’un genre nouveau. Facebook 1914, le quotidien de la première guerre offre une ... [more ▼]

« En 2013, le Musée de la Grande Guerre du Pays de Meaux et l’agence de communication DDB ont élaboré une page Facebook d’un genre nouveau. Facebook 1914, le quotidien de la première guerre offre une forme de médiation a priori inédite pour un musée français. Elle présente l’histoire d’un personnage de fiction, Léon Vivien, qui raconte son quotidien lors de la première guerre mondiale, sur Facebook, comme si ce réseau social avait existé à cette époque. Cette contribution met en évidence certains des effets de sens de la page par une analyse sémiotique du dispositif et une analyse thématique de ses contenus. Nous questionnons ensuite cette « nouvelle » forme de médiation qui se dit « participante » et qui, en réalité, reste assez classique dans son contenu et sous-exploite le potentiel de Facebook. » [less ▲]

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See detailMajorization-Minimization Algorithms for Analog Beamforming with Large-Scale Antenna Arrays
Arora, Aakash UL; Tsinos, Christos UL; Shankar, Bhavani UL et al

in Proc. 7th IEEE Global Conference on Signal and Information Processing (GlobalSIP) 2019 (in press)

Beamforming with large-scale antenna arrays (LSAA) is one of the predominant operations in designing wireless communication systems. However, the implementation of a fully digital system significantly ... [more ▼]

Beamforming with large-scale antenna arrays (LSAA) is one of the predominant operations in designing wireless communication systems. However, the implementation of a fully digital system significantly increases the number of required radio-frequency (RF) chains, which may be prohibitive. Thus, analog beamforming based on a phase-shifting network driven by a variable gain amplifier (VGA) is a potential alternative technology. In this paper, we cast the beamforming vector design problem as a beampattern matching problem, with an unknown power gain. This is formulated as a unit-modulus least-squares (ULS) problem where the optimal gain of the VGA is also designed in addition to the beamforming vector. We also consider a scenario where the receivers have the additional processing capability to adjust the phases of the incoming signals to mitigate specular multipath components. We propose efficient majorization-minimization (MM) based algorithms with convergence guarantees to a stationary point for solving both variants of the proposed ULS problem. Numerical results verify the effectiveness of the proposed solution in comparison with the existing state-of-the-art techniques. [less ▲]

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See detailMM-Based Solution for Partially Connected Hybrid Transceivers with Large Scale Antenna Arrays
Arora, Aakash UL; Tsinos, Christos UL; Shankar, Bhavani UL et al

in Proc. 2019 IEEE Global Communications Conference (GLOBECOM) (in press)

In a mmWave multiple-input multiple-output (MIMO) communication system employing a large-scale antenna array (LSAA), the hybrid transceivers are used to reduce the power consumption and the hardware cost ... [more ▼]

In a mmWave multiple-input multiple-output (MIMO) communication system employing a large-scale antenna array (LSAA), the hybrid transceivers are used to reduce the power consumption and the hardware cost. In a hybrid analog-digital (A/D) transceiver, the pre/post-processing operation splits into a lower-dimensional baseband (BB) pre/postcoder, followed by a network of analog phase shifters. Primarily two kinds of hybrid architectures are proposed in the literature to implement hybrid transceivers namely, the fully-connected and the partially-connected. Implementation of fully-connected architecture has higher hardware complexity, cost and power consumption in comparison with partially-connected. In this paper, we focus on partially-connected hybrid architecture and develop a low-complexity algorithm for transceiver design for a single user point-to-point mmWave MIMO system. The proposed algorithm utilizes the variable elimination (projection) and the minorization-maximization (MM) frameworks and has convergence guarantees to a stationary point. Simulation results demonstrate that the proposed algorithm is easily scalable for LSAA systems and achieves significantly improved performance in terms of the spectral efficiency (SE) of the system compared to the state-of-the-art solution. [less ▲]

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See detailTopologie culinaire au cinéma : le lieu commun du repas et ses déclinaison
Roelens, Nathalie UL

in Bibliothèque électronique Paris 8 (in press)

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See detailUML Consistency Rules:a Case Study with Open-Source UML Models
Torre, Damiano UL; Labiche, Yvan; Genero, Marcela et al

in Proceedings of the 8th International Conference on Formal Methods in Software Engineering (in press)

UML models are standard artifacts used by software engineers for designing software. As software is designed, different UML diagram types (e.g., class diagrams and sequence diagrams) are produced by ... [more ▼]

UML models are standard artifacts used by software engineers for designing software. As software is designed, different UML diagram types (e.g., class diagrams and sequence diagrams) are produced by software designers. Since the various UML diagram types describe different aspects of a software system, they are not independent but strongly depend on each other, hence they must be consistent. Inconsistencies cause faults in the final software systems. It is, therefore, paramount that they get detected, analyzed, and fixed. Consistency rules are a useful tool proposed in the literature to detect inconsistencies. They categorize constraints that help in identifying inconsistencies when violated. This case study aims at collecting and analyzing UML models with OCL consistency rules proposed in the literature and at promoting the development of a reference benchmark that can be reused by the (FM-)research community. We collected 33 UML consistency rules and 206 different UML diagrams contained in 34 open-source UML models presented in the literature. We propose an FM-based encoding of the consistency rules in OCL. This encoding allows analyzing whether the consistency rules are satisfied or violated within the 34 UML models. To assess the proposed benchmark, we analyzed how the UML models, consistency rules, diagram types contained in the benchmark help in assessing the consistency of UML models, and the consistency of diagrams across the different software development phases. Our results show that the considered UML models and consistency rules allowed identifying 2731 inconsistencies and that those inconsistencies refer to different software development phases. We concluded that the considered UML models and consistency rules could be considered as an initial benchmark that can be further extended by the research community. [less ▲]

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See detailWidths of regular and context-free languages
Mestel, David UL

in 39th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2019) (in press)

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See detailMining Assumptions for Software Components using Machine Learning
Gaaloul, Khouloud UL; Menghi, Claudio UL; Nejati, Shiva UL et al

in Proceedings of the The ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE) (in press)

Software verification approaches aim to check a software component under analysis for all possible environments. In reality, however, components are expected to operate within a larger system and are ... [more ▼]

Software verification approaches aim to check a software component under analysis for all possible environments. In reality, however, components are expected to operate within a larger system and are required to satisfy their requirements only when their inputs are constrained by environment assumptions. In this paper, we propose EPIcuRus, an approach to automatically synthesize environment assumptions for a component under analysis (i.e., conditions on the component inputs under which the component is guaranteed to satisfy its requirements). EPIcuRus combines search-based testing, machine learning and model checking. The core of EPIcuRus is a decision tree algorithm that infers environment assumptions from a set of test results including test cases and their verdicts. The test cases are generated using search-based testing, and the assumptions inferred by decision trees are validated through model checking. In order to improve the efficiency and effectiveness of the assumption generation process, we propose a novel test case generation technique, namely Important Features Boundary Test (IFBT), that guides the test generation based on the feedback produced by machine learning. We evaluated EPIcuRus by assessing its effectiveness in computing assumptions on a set of study subjects that include 18 requirements of four industrial models. We show that, for each of the 18 requirements, EPIcuRus was able to compute an assumption to ensure the satisfaction of that requirement, and further, ≈78% of these assumptions were computed in one hour. [less ▲]

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See detailBlockchain Governance: An Overview and Prediction of Optimal Strategies Using Nash Equilibrium
Khan, Nida UL; Ahmad, Tabrez; Patel, Anass et al

in 3rd AUE International Research Conference (in press)

Blockchain governance is a subject of ongoing research and an interdisciplinary view of blockchain governance is vital to aid in further research for establishing a formal governance framework for this ... [more ▼]

Blockchain governance is a subject of ongoing research and an interdisciplinary view of blockchain governance is vital to aid in further research for establishing a formal governance framework for this nascent technology. In this paper, the position of blockchain governance within the hierarchy of Institutional governance is discussed. Blockchain governance is analyzed from the perspective of IT governance using Nash equilibrium to predict the outcome of different governance decisions. A payoff matrix for blockchain governance is created and simulation of different strategy profiles is accomplished for computation of all Nash equilibria. We also create payoff matrices for different kinds of blockchain governance, which were used to propose novel mathematical formulae usable to predict the best governance strategy that minimizes the occurrence of a hard fork as well as predicts the behavior of the majority during protocol updates. [less ▲]

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See detailIntegrating Topological Proofs with Model Checking to Instrument Iterative Design
Menghi, Claudio UL; Rizzi, Alessandro Maria; Bernasconi, Anna

in Proceedings of the 23rd International Conference on Fundamental Approaches to Software Engineering, FASE 2020 (in press)

System development is not a linear, one-shot process. It proceeds through refinements and revisions. To support assurance that the system satisfies its requirements, it is desirable that continuous ... [more ▼]

System development is not a linear, one-shot process. It proceeds through refinements and revisions. To support assurance that the system satisfies its requirements, it is desirable that continuous verification can be performed after each refinement or revision step. To achieve practical adoption, formal verification must accommodate continuous verification efficiently and effectively. Model checking provides developers with information useful to improve their models only when a property is not satisfied, i.e., when a counterexample is returned. However, it is desirable to have some useful information also when a property is instead satisfied. To address this problem we propose TOrPEDO, an approach that supports verification in two complementary forms: model checking and proofs. While model checking is typically used to pinpoint model behaviors that violate requirements, proofs can instead explain why requirements are satisfied. In our work, we introduce a specific notion of proof, called Topological Proof. A topological proof produces a slice of the original model that justifies the property satisfaction. Because models can be incomplete, TOrPEDO supports reasoning on requirements satisfaction, violation, and possible satisfaction (in the case where satisfaction depends on unknown parts of the model). Evaluation is performed by checking how topological proofs support software development on 12 modeling scenarios and 15 different properties obtained from 3 examples from literature. Results show that: (i) topological proofs are ≈60% smaller than the original models; (ii) after a revision, in ≈78% of cases, the property can be re-verified by relying on a simple syntactic check. [less ▲]

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See detailAn AI-assisted Approach for Checking the Completeness of Privacy Policies Against GDPR
Torre, Damiano UL; Abualhaija, Sallam UL; Sabetzadeh, Mehrdad UL et al

in in Proceedings of the 28th IEEE International Requirements Engineering Conference (RE’20) (in press)

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See detailConservazione e ricezione dei documenti pontifici in Italia settentrionale: il caso del monastero cistercense di Chiaravalle Milanese (secoli XII-XVI)
Salemme, Timothy UL

in Salemme, Timothy; Renault, Jean-Baptiste (Eds.) Conservation et réception des documents pontificaux par les Ordres religieux (XIe-XVe siècles). Actes du colloque international. Nancy, 12-13 décembre 2013 (in press)

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See detailHybrid Analog-Digital Precoding Design for Satellite Systems
Arora, Aakash UL; Tsinos, Christos UL; Shankar, Bhavani UL et al

in Proc. 37th International Communications Satellite Systems Conference (ICSSC'19) (in press)

The work investigates the feasibility of massive MIMO in SatCom. Towards this, the necessary channel models, system parameters and scenarios are identified and a basic simulator developed. The work then ... [more ▼]

The work investigates the feasibility of massive MIMO in SatCom. Towards this, the necessary channel models, system parameters and scenarios are identified and a basic simulator developed. The work then considers an efficient implementation of the massive MIMO transmission through the use of hybrid analog/digital precoder. Efficient algorithmic solutions are proposed for the partially connected precoder architecture which enables efficiency in power/ hardware complexity and its performance evaluated. [less ▲]

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See detailGoal-Directed Decision Procedures for Input/Output Logics
Steen, Alexander UL

in Marra, Alessandra; Liu, Fenrong; Portner, Paul (Eds.) et al Deontic Logic and Normative Systems - 15th International Conference, DEON 2020/2021 (in press)

Input/Output (I/O) logics address the abstract study of conditional norms. Here, norms are represented as pairs of formulas instead of statements that themselves carry truth-values. I/O logics have been ... [more ▼]

Input/Output (I/O) logics address the abstract study of conditional norms. Here, norms are represented as pairs of formulas instead of statements that themselves carry truth-values. I/O logics have been studied thoroughly in the past, including further applications and refinements. In this paper, a class of automated reasoning procedures is presented that, given a set of norms and a concrete situation, decide whether a specific state of affairs is obligatory according to the output operations of I/O logics. The procedures are parametric in the underlying logical formalism and can be instantiated with different classical objects logics, such as propositional logic or first-order logic. The procedures are shown to be correct, and a proof-of-concept implementation for propositional I/O logics is surveyed. [less ▲]

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See detailThe legacy of coal mining – a view on examples in Belgium and France
Helfer, Malte UL

in Deutsches Bergbau-Museum Bochum (Ed.) Boom – Crisis – Heritage. King Coal and Energy Revolutions after 1945; proceedings of the international conference March 14th-16th 2018, Technische Hochschule Georg Agricola, Bochum (in press)

Following the end of coalmining in Belgium (1992) and France (2004), the year 2018 marks the end of hard coal mining in Germany as well. This contribution looks at the legacy of coalmining of Germany’s ... [more ▼]

Following the end of coalmining in Belgium (1992) and France (2004), the year 2018 marks the end of hard coal mining in Germany as well. This contribution looks at the legacy of coalmining of Germany’s French-speaking neighbours and presents the most important remaining coal mining heritage sites as well as some extraordinary converted sites in France and the Belgian province Wallonia. [less ▲]

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See detailFlipping Geometric Triangulations on Hyperbolic Surfaces
Despré, vincent; Schlenker, Jean-Marc UL; Teillaud, Monique

in symposium on computational geometry (SoCG) (in press)

We consider geometric triangulations of surfaces, i.e., triangulations whose edges can be realized by disjoint locally geodesic segments. We prove that the flip graph of geometric triangulations with ... [more ▼]

We consider geometric triangulations of surfaces, i.e., triangulations whose edges can be realized by disjoint locally geodesic segments. We prove that the flip graph of geometric triangulations with fixed vertices of a flat torus or a closed hyperbolic surface is connected. We give upper bounds on the number of edge flips that are necessary to transform any geometric triangulation on such a surface into a Delaunay triangulation. [less ▲]

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See detailPVDeConv: Point-Voxel Deconvolution for Autoencoding CAD Construction in 3D
Cherenkova, Kseniya UL; Aouada, Djamila UL; Gusev, Gleb

Scientific Conference (2020, October)

We propose a Point-Voxel DeConvolution (PVDeConv) mod- ule for 3D data autoencoder. To demonstrate its efficiency we learn to synthesize high-resolution point clouds of 10k points that densely describe ... [more ▼]

We propose a Point-Voxel DeConvolution (PVDeConv) mod- ule for 3D data autoencoder. To demonstrate its efficiency we learn to synthesize high-resolution point clouds of 10k points that densely describe the underlying geometry of Computer Aided Design (CAD) models. Scanning artifacts, such as pro- trusions, missing parts, smoothed edges and holes, inevitably appear in real 3D scans of fabricated CAD objects. Learning the original CAD model construction from a 3D scan requires a ground truth to be available together with the corresponding 3D scan of an object. To solve the gap, we introduce a new dedicated dataset, the CC3D, containing 50k+ pairs of CAD models and their corresponding 3D meshes. This dataset is used to learn a convolutional autoencoder for point clouds sampled from the pairs of 3D scans - CAD models. The chal- lenges of this new dataset are demonstrated in comparison with other generative point cloud sampling models trained on ShapeNet. The CC3D autoencoder is efficient with respect to memory consumption and training time as compared to state- of-the-art models for 3D data generation. [less ▲]

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See detailBridging the Gap between Requirements Modeling and Behavior-driven Development
Alferez, Mauricio UL; Pastore, Fabrizio UL; Sabetzadeh, Mehrdad UL et al

in Proceedings of 22nd IEEE / ACM International Conference on Model Driven Engineering Languages and Systems (MODELS) (2020, September)

Acceptance criteria (AC) are implementation agnostic conditions that a system must meet to be consistent with its requirements and be accepted by its stakeholders. Each acceptance criterion is typically ... [more ▼]

Acceptance criteria (AC) are implementation agnostic conditions that a system must meet to be consistent with its requirements and be accepted by its stakeholders. Each acceptance criterion is typically expressed as a natural-language statement with a clear pass or fail outcome. Writing AC is a tedious and error-prone activity, especially when the requirements specifications evolve and there are different analysts and testing teams involved. Analysts and testers must iterate multiple times to ensure that AC are understandable and feasible, and accurately address the most important requirements and workflows of the system being developed. In many cases, analysts express requirements through models, along with natural language, typically in some variant of the UML. AC must then be derived by developers and testers from such models. In this paper, we bridge the gap between requirements models and AC by providing a UML-based modeling methodology and an automated solution to generate AC. We target AC in the form of Behavioral Specifications in the context of Behavioral-Driven Development (BDD), a widely used agile practice in many application domains. More specially we target the well-known Gherkin language to express AC, which then can be used to generate executable test cases. We evaluate our modeling methodology and AC generation solution through an industrial case study in the financial domain. Our results suggest that (1) our methodology is feasible to apply in practice, and (2) the additional modeling effort required by our methodology is outweighed by the benefits the methodology brings in terms of automated and systematic AC generation and improved model precision. [less ▲]

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See detailScientific Instruments in Constcamer Paintings: Pictorial Space as a Context for Interpretation
Koeleman, Floor UL

Scientific Conference (2020, September)

Representations of scientific instruments abound in the seventeenth-century genre of constcamer paintings. These works of art depict interiors full of rich collections of artifacts, natural materials ... [more ▼]

Representations of scientific instruments abound in the seventeenth-century genre of constcamer paintings. These works of art depict interiors full of rich collections of artifacts, natural materials, animals and people, and were created almost exclusively in Antwerp and Brussels. In contrast to material and written sources, such images provide us with a context, captured in paint, which contributes to our understanding of the contemporary meaning of scientific instruments. This presentation will highlight the wide variety of instruments (mainly optical and mathematical) that are included in constcamer paintings. Depending on how we define ‘scientific instrument’, between 63 and 100 constcamer paintings from the early modern period can be identified as including representations of scientific instruments. The study of these images from the perspective of the visual and material culture of science not only provides further insight into the variety of instruments that existed at the time, but also sheds light on how painters produced these representations, either by using an actual object or by resorting to a preexisting depiction. It will be shown that the instruments in the paintings reflect a thriving glass industry and the activity of skilled goldsmiths in local workshops and at the archducal court. While over the course of the seventeenth century the novelty of such instruments declined, their association with knowledge of nature, the role of vision and the art of painting persisted. As such, the instruments in constcamer paintings denote both a practical and a philosophical dimension, relating to the world of the senses as well as the intellect. [less ▲]

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See detailCollective Knowledge Production in Educational Ethnography: From Team-Ethnography to European Cooperation and Beyond
Maeder, Christoph; Kuhn, Melanie; Neumann, Sascha et al

Scientific Conference (2020, August)

Ethnography can be regarded as being inherently collaborative (see: Lassiter 2005). But if we accept ethnography as a collaborative, cooperative and joint production of knowledge, many questions namely ... [more ▼]

Ethnography can be regarded as being inherently collaborative (see: Lassiter 2005). But if we accept ethnography as a collaborative, cooperative and joint production of knowledge, many questions namely around cooperation within and between people, projects, disciplines, places, organizations and research teams etc. arise. In this panel discussion we want to explore and discuss questions and challenges of different levels of collaboration, or ways of working together in educational ethnography under the auspices of the production of knowledge on education. [...] [less ▲]

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See detailSTEAM Education in elementary schools: A holistic investigation on technology enhanced teaching and learning
Haas, Ben; Lavicza, Zsolt; Kreis, Yves UL

Scientific Conference (2020, July 03)

When we address the learning of mathematics in elementary school, we imagine pupils doing experiments, discoveries, and combining the different elements from arithmetics to geometry. Pupils interact with ... [more ▼]

When we address the learning of mathematics in elementary school, we imagine pupils doing experiments, discoveries, and combining the different elements from arithmetics to geometry. Pupils interact with their environment and try to use their learned skills to get a deeper understanding of the world. They engage in a mathematical thinking process and try to interact with their environment. However, when you visit a classroom, you find a rather old fashioned teaching based on a deductive approach where imitations of technics play an essential role. Based on our observations, pupils learn mainly through to repetitions in textbooks. Experimentation, if any, comes as additional work, it is seen as a ludic activity rather than as real learning activity. In our research, we inquired about different ways to engage pupils in an experimental approach. We used digital and physical modulation, augmented reality, and various educational technologies. In one of our first studies, we designed a tutoring system to foster process-related skills in mathematics within the educational software MathemaTIC . We collected data on pupils in assessments on transferring mathematical thinking from instructional technology to the everyday classroom teaching. In a second study, we worked with pupils from elementary schools, kindergarten, and from the special needs section to go beyond two-dimensional representations and discover how mathematics operates in three-dimensional settings. Pupils worked on designing software and three-dimensional printing. We collected data on how pupils and parents perceived the learning and teaching and how this influences the further thinking in mathematics. In a holistic approach, we aimed to identify how pupils, teachers and parents perceive the learning through these new technologies and how it affects the learning and teaching. Our research happened in onsite and remote teaching. In this conference, we will present results from the different studies, give insights into our research, and present future experimental investigations. [less ▲]

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See detailEthische Aspekte im reflexiven Schulpraktikum. Eine Ethik des Lebens für Praxisbegleiter
Weber, Jean-Marie UL

Scientific Conference (2020, July 03)

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See detailA short Survey on the Cyber Security in Control Systems
Bezzaoucha, Souad UL; Voos, Holger UL

Scientific Conference (2020, July)

In the present survey paper, we give a short, yet exhaustive state-of-the-art about the cyber-security applied to control systems, especially the event-based strategy. Indeed, in the past few years, due ... [more ▼]

In the present survey paper, we give a short, yet exhaustive state-of-the-art about the cyber-security applied to control systems, especially the event-based strategy. Indeed, in the past few years, due to a highest degree of connectivity in modern systems, new related control-specific cyber-physical systems security challengesarise and novel approaches integrating the cyber aspect are developed.Our goal in this paper is then to provide an overview of attack-modeling and security analysis approaches in recent works thatexplore networked control systems subject to cyber-attacks attacks. To this end, we look at the control, estimation, and modeling problems. [less ▲]

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See detailSystematic derivation of Generalized Langevin Equations for coarse-graining and bridge-scaling procedures
Meyer, Hugues UL

Scientific Conference (2020, July)

In many branches of physics, one must often deal with processes involving a huge number of degrees of freedom. Instead of describing the dynamics of each individual of them, one rather wants to ... [more ▼]

In many branches of physics, one must often deal with processes involving a huge number of degrees of freedom. Instead of describing the dynamics of each individual of them, one rather wants to characterize the process of interest via a small set of observ- ables that capture its main features of the process. Even if the microscopic dynamics can be resolved using Newton’s equations of motion, it quickly becomes a computation- ally very expensive calculation to make. It is however much more convenient to come up with a self-consistent equation of motion for the ’global’ observable of interest itself in order to reduce the complexity of the problem. The development of the Mori-Zwanzig formalism in the 1960’s allowed to systematically derive such equations for arbitrary observables in stationary processes. This framework, derived from first principles by means of projection operator techniques, proves the structure of what is now known as the Generalized Langevin Equation, i.e. a stochastic equation of motion which a priori exhibits memory effects in the form on non-localities in time. We propose to extend the formalism and its corollaries to a broad class of out-of- equilibrium processes. We show that the structure of the Generalized Langevin Equa- tion is overall robust but must be adapted to account for the non-stationary dynamics [1,2]. The function that controls memory effects the stochastic term are related through a relation that can be associated to fluctuation-dissipation theorems. This formalism is very convenient to study two-time auto-correlation functions for which we can write a self-consistent differential equation as well. We finally show a new method to evaluate the memory function from numerical or experimental data [3]. [less ▲]

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See detailPractical aspects of the Bank-Weiser estimator implementation and Biomechanics applications.
Bulle, Raphaël UL; Bordas, Stéphane UL; Chouly, Franz et al

Scientific Conference (2020, July)

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See detailMeasuring multiculturalism: Scale development and validation in different languages and contexts (Cancelled due to COVID-19)
Stogianni, Maria UL; Schmidt, Lea Marie; Murdock, Elke UL et al

Scientific Conference (2020, July)

Increased migration has led to the formation of culturally diverse societies in most places around the world. Consequently, individuals of different ethnic backgrounds need to find ways of living together ... [more ▼]

Increased migration has led to the formation of culturally diverse societies in most places around the world. Consequently, individuals of different ethnic backgrounds need to find ways of living together. Multiculturalism as an ideology and policy framework proposes several strategies to deal with increasing diversity and to improve intergroup relations in multicultural contexts. Berry (2016) emphasizes two important aspects of multiculturalism: a) diversity, the presence of ethnocultural diversity in the population and b) equity, the right for equal participation of all cultural groups in the society. Both diversity and equity are necessary conditions for the success of multicultural policies. Culturally heterogeneous communities that do not support inclusion and equitable participation of all groups, face the negative consequences of segregation. In line with this notion, an international research consortium developed a revised version of the Multicultural Ideology Scale (Berry & Kalin, 1995) to assess support for cultural diversity. The scale aims to distinguish various attitudinal dimensions of multiculturalism, relevant to the acceptance and social inclusion of different ethnocultural groups: Cultural Maintenance, Equity/Inclusion, Social interaction, Essentialistic Boundaries, Extent of Differences, and Conflictual Relations. The present study is part of this cross-cultural research project, which aims to develop and test the psychometric properties of the scale in different language versions and cultural contexts. The survey will be administered to a large sample of native German citizens with different demographic characteristics. We aim to understand the attitude of native citizens towards cultural diversity and their willingness to interact with members of ethnic minority groups. We will also investigate the relationship between multicultural attitudes and individual difference variables, such as ethnic group attachment and social dominance orientation. Findings from all the country studies in the project will enable us develop a universal measure of multicultural attitudes that can be applied in multiple groups and contexts. [less ▲]

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See detailDATA DRIVEN SURGICAL SIMULATIONS
Deshpande, Saurabh UL; Bordas, Stéphane UL; Beex, Lars UL et al

Scientific Conference (2020, July)

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See detailInverse simulation for retrieving the undeformed position for hyperelastic materials : application to breast simulations
Mazier, Arnaud UL; Bilger, Alexandre; Forte, Antonio et al

Scientific Conference (2020, July)

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See detailAutomated Repair of Feature Interaction Failures in Automated Driving Systems
Ben Abdessalem, Raja; Panichella, Annibale; Nejati, Shiva UL et al

in Proceedings of the 29th ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA 2020) (2020, July)

In the past years, several automated repair strategies have been proposed to fix bugs in individual software programs without any human intervention. There has been, however, little work on how automated ... [more ▼]

In the past years, several automated repair strategies have been proposed to fix bugs in individual software programs without any human intervention. There has been, however, little work on how automated repair techniques can resolve failures that arise at the system-level and are caused by undesired interactions among different system components or functions. Feature interaction failures are common in complex systems such as autonomous cars that are typically built as a composition of independent features (i.e., units of functionality). In this paper, we propose a repair technique to automatically resolve undesired feature interaction failures in automated driving systems (ADS) that lead to the violation of system safety requirements. Our repair strategy achieves its goal by (1) localizing faults spanning several lines of code, (2) simultaneously resolving multiple interaction failures caused by independent faults, (3) scaling repair strategies from the unit-level to the system-level, and (4) resolving failures based on their order of severity. We have evaluated our approach using two industrial ADS containing four features. Our results show that our repair strategy resolves the undesired interaction failures in these two systems in less than 16h and outperforms existing automated repair techniques. [less ▲]

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See detailThe development and validation of a short conscientiousness questionnaire for large-scale educational assessment
van der Westhuizen, Lindie UL; Franzen, Patrick UL; Arens, A. Katrin et al

Scientific Conference (2020, July)

Conscientiousness and its subfacets are related to multiple learning-related outcomes. MacCann, Duckworth and Roberts (2009) developed a questionnaire measuring seven subfacets of conscientiousness with ... [more ▼]

Conscientiousness and its subfacets are related to multiple learning-related outcomes. MacCann, Duckworth and Roberts (2009) developed a questionnaire measuring seven subfacets of conscientiousness with 59 items. However, the resources required to complete such long scales often renders it unsuitable for large-scale educational assessment. Consequently, an economic and psychometrically sound conscientiousness questionnaire that is specifically customized for this context is needed. We developed and validated a short version of the MacCann et al. (2009) questionnaire. In study 1, French and German adaptations of the questionnaire were administered to a representative dataset comprising all ninth-graders in Luxembourg (N1=6325, Cohort 2017). Using an exhaustive search algorithm, we identified the optimal combination of four items for each subfacet by simultaneously considering three criteria: goodness of fit, factor saturation, and scalar measurement invariance across the German and French versions. In study 2, we validated our short 28-item questionnaire on a second, independent sample comprising 6,279 Luxembourgish ninth-graders (Cohort 2018). A 7-factor model assuming separate factors for each subfacet obtained acceptable fit (CFI=.93, RMSEA=.04, SRMR=.06). The criterion validity for each subfacet was tested by examining the relation to standardized achievement tests (SATs). In study 3, drawing on a dataset of 275 tenth-graders (linked longitudinally with the ninth-grade data from study 1), evidence of predictive validity (i.e., school grades) was examined. The subfacets of industriousness, caution and perfectionism showed the strongest relations with both SATs (study 2) and school grades (study 3). Our study delivered a short, valid and reliable questionnaire for the assessment of seven conscientiousness facets in the educational context. The scale is invariant across the German and French language versions and its brevity makes it suitable for large-scale educational assessment. [less ▲]

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See detailImproving open data accessibility through package development and community work
Kozlowski, Diego UL; Tiscornia, Pablo; Weksler, Guido et al

Poster (2020, July)

Detailed reference viewed: 67 (2 UL)
See detailWhen historians create their archives: the making of covidmemory project
Brüll, Christoph UL

Scientific Conference (2020, June 30)

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See detailPolitiques de synchronisation dans les systèmes multi-agents distribués parallèles
Rousset, Alban UL; Breugnot, Paul; Herrmann, Bénédicte et al

in Rousset, Alban (Ed.) Politiques de synchronisation dans les systèmes multi-agents distribués parallèles (2020, June 29)

Among simulation or modelisation methods, multi-agent systems are an interesting candidate to simulate complex systems. As the size of the model's increases, the use of parallel multi-agent systems is ... [more ▼]

Among simulation or modelisation methods, multi-agent systems are an interesting candidate to simulate complex systems. As the size of the model's increases, the use of parallel multi-agent systems is mandatory but comes with many issues. In this article, we are interested in the impact of synchronization on models design and on their execution. We highlight synchronization problems through model instances then we experimentally analyze the impact of synchronization on large scale test cases. [less ▲]

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See detailSTEAM in special needs education in an elementary school in Luxemburg
Haas, Ben; Lavicza, Zsolt; Kreis, Yves UL

Scientific Conference (2020, June 25)

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See detailPIAF: Developing Computational and Algorithmic Thinking in Fundamental Education
Parmentier, Yannick; Reuter, Robert UL; Higuet, Sarah et al

in Proceedings of EdMedia + Innovate Learning (2020, June 23), 2020(1), 315-322

In this article, we present the objectives and first achievements of the PIAF project supported by the European Union and aiming at developing computational and algorithmic thinking in basic education ... [more ▼]

In this article, we present the objectives and first achievements of the PIAF project supported by the European Union and aiming at developing computational and algorithmic thinking in basic education. This project brings together researchers in educational sciences and computer science from four countries (Belgium, France, Germany and Luxembourg) around the theme of teacher training. More concretely, the aim is to define a framework (competency framework, pedagogical scenarios) enabling teachers to (i) appropriate the concept of computational and algorithmic thinking and (ii) implement learning activities that promote the development of this kind of thinking in children. [less ▲]

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See detailInnovative uses of technologies for STEAM education in elementary schools in Luxemburg
Haas, Ben; Kreis, Yves UL

Scientific Conference (2020, June 23)

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See detailDecision Triggered Data Transmission and Collection in Industrial Internet of Things
He, Jiguang; Kong, Long UL; Frondelius, Tero et al

in 2020 IEEE Wireless Communications and Networking Conference (WCNC) (2020, June 19)

We propose a decision triggered data transmission and collection (DTDTC) protocol for condition monitoring and anomaly detection in the industrial Internet of things (IIoT). In the IIoT, the collection ... [more ▼]

We propose a decision triggered data transmission and collection (DTDTC) protocol for condition monitoring and anomaly detection in the industrial Internet of things (IIoT). In the IIoT, the collection, processing, encoding, and transmission of the sensor readings are usually not for the reconstruction of the original data but for decision making at the fusion center. By moving the decision making process to the local end devices, the amount of data transmission can be significantly reduced, especially when normal signals with positive decisions dominate in the whole life cycle and the fusion center is only interested in collecting the abnormal data. The proposed concept combines compressive sensing, machine learning, data transmission, and joint decision making. The sensor readings are encoded and transmitted to the fusion center only when abnormal signals with negative decisions are detected. All the abnormal signals from the end devices are gathered at the fusion center for a joint decision with feedback messages forwarded to the local actuators. The advantage of such an approach lies in that it can significantly reduce the volume of data to be transmitted through wireless links. Moreover, the introduction of compressive sensing can further reduce the dimension of data tremendously. An exemplary case, i.e., diesel engine condition monitoring, is provided to validate the effectiveness and efficiency of the proposed scheme compared to the conventional ones. [less ▲]

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See detailNetworked Governance, Enabling Multistakeholder Cooperation
Van Weyenbergh, Gael; Bouillard, Maxime; Wieneke, Lars UL et al

Scientific Conference (2020, June 12)

This workshop gathering 10 participants focused on finding the root cause for the need and purpose for multistakeholder cooperation between social scientists and civil society.

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See detailDiscovering Everyday Mathematical Situations Outside the Classroom with MathCityMap and GeoGebra 3D
Lavicza, Zsolt; Haas, Ben; Kreis, Yves UL

in Ludwig, Matthias; Jablonski, Simone; Caldeira, Amélia (Eds.) et al Research on Outdoor STEM Education in the digiTal Age: Proceedings of the ROSETA Online Conference in June 2020 (2020, June 10)

In elementary school, teaching and learning activities aim to develop, among others, students’ skills to acquire deeper understanding of their living environments. There are numerous opportunities for ... [more ▼]

In elementary school, teaching and learning activities aim to develop, among others, students’ skills to acquire deeper understanding of their living environments. There are numerous opportunities for students to recognize forms, shapes, and mathematical connections in everyday situations. These everyday situations can be simulated in classrooms; however, educational technologies offer new approaches to extend classroom activities, teachers can simulate and design shapes through Augmented Reality and 3D printing within or beyond the classroom. To stimulate students’ everyday mathematical connections utilizing these technologies could assist in developing activities outside the classroom in urban or in natural environments. Through this approach students could utilize or enhance their mathematical and technical skills within their usual living environments. Utilising educational software such as MathCityMap, GeoGebra 3D Calculator, and other 3D modelling software we developed examples of tasks that could offer easy transitions from in- to out-side of classrooms. In this paper, we will describe learning and teaching aims of these tasks and outline further research and development directions to broaden opportunities to develop students’ mathematical, design and modelling skills. [less ▲]

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See detailThe rise of eBPF for non-intrusive performance monitoring
Cassagnes, Cyril UL; Trestioreanu, Lucian Andrei UL; Joly, Clement UL et al

in IEEE Xplore (2020, June 08)

In this paper, we explain that container engines are strengthening their isolation mechanisms. Therefore, nonintrusive monitoring becomes a must-have for the performance analysis of containerized user ... [more ▼]

In this paper, we explain that container engines are strengthening their isolation mechanisms. Therefore, nonintrusive monitoring becomes a must-have for the performance analysis of containerized user-space application in production environments. After a literature review and background of Linux subsystems and container isolation concepts, we present our lessons learned of using the extended Berkeley packet filter to monitor and profile performance. We carry out the profiling and tracing of several Interledger connectors using two full-fledged implementations of the Interledger protocol specifications. [less ▲]

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See detailA Novel Heap-based Pilot Assignment for Full Duplex Cell-Free Massive MIMO with Zero-Forcing
Nguyen, Van Hieu; Nguyen, van Dinh UL; Dobre, Octavia A. et al

in IEEE International Conference on Communications (2020, June 07)

This paper investigates the combined benefits of full-duplex (FD) and cell-free massive multiple-input multipleoutput (CF-mMIMO), where a large number of distributed access points (APs) having FD ... [more ▼]

This paper investigates the combined benefits of full-duplex (FD) and cell-free massive multiple-input multipleoutput (CF-mMIMO), where a large number of distributed access points (APs) having FD capability simultaneously serve numerous uplink and downlink user equipments (UEs) on the same time-frequency resources. To enable the incorporation of FD technology in CF-mMIMO systems, we propose a novel heapbased pilot assignment algorithm, which not only can mitigate the effects of pilot contamination but also reduce the involved computational complexity. Then, we formulate a robust design problem for spectral efficiency (SE) maximization in which the power control and AP-UE association are jointly optimized, resulting in a difficult mixed-integer nonconvex programming. To solve this problem, we derive a more tractable problem before developing a very simple iterative algorithm based on inner approximation method with polynomial computational complexity. Numerical results show that our proposed methods with realistic parameters significantly outperform the existing approaches in terms of the quality of channel estimate and SE. [less ▲]

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See detailToward an SDN-based Data Collection Scheme for Vehicular Fog Computing
Boualouache, Abdelwahab UL; Soua, Ridha UL; Engel, Thomas UL

in IEEE International Conference on Communications ICC'2020 (2020, June 07)

With the integration of fog networks and vehicular networks, Vehicular Fog Computing (VFC) is a promising paradigm to efficiently collect data for improving safety, mobility, and driver experience during ... [more ▼]

With the integration of fog networks and vehicular networks, Vehicular Fog Computing (VFC) is a promising paradigm to efficiently collect data for improving safety, mobility, and driver experience during journeys. To this end, we exploit the Software-Defined Networking (SDN) paradigm to propose a fully-programmable, self-configurable, and context-aware data collection scheme for VFC. This scheme leverages a stochastic model to dynamically estimate the number of fog stations to be deployed. Our simulation results demonstrate that our proposed scheme provides lower latency and higher resiliency compared to classical data collection schemes. [less ▲]

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See detailThe relevance of risk disclosure and the role of readability and comparability
Weber, Véronique UL; Muessig, Anke UL

Scientific Conference (2020, June 05)

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See detailPractical Posterior Error Bounds from Variational Objectives
Huggins, Jonathan; Kasprzak, Mikolaj UL; Campbell, Trevor et al

in Proceedings of the 23rd International Conference on Artificial Intelligence and Statistics (AISTATS) (2020, June)

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See detailSuccessive Convex Approximation for Transmit Power Minimization in SWIPT-Multicast Systems
Gautam, Sumit UL; Lagunas, Eva UL; Kisseleff, Steven UL et al

Scientific Conference (2020, June)

We propose a novel technique for total transmit power minimization and optimal precoder design in wireless multi-group (MG) multicasting (MC) systems. The considered framework consists of three different ... [more ▼]

We propose a novel technique for total transmit power minimization and optimal precoder design in wireless multi-group (MG) multicasting (MC) systems. The considered framework consists of three different systems capable of handling heterogeneous user types viz., information decoding (ID) specific users with conventional receiver architectures, energy harvesting (EH) only users with non-linear EH module, and users with joint ID and EH capabilities having separate units for the two operations, respectively. Each user is categorized under unique group(s), which can be of MC type specifically meant for ID users, and/or an energy group consisting of EH explicit users. The joint ID and EH users are a part of the (last) EH group as well as any one of the MC groups distinctly. In this regard, we formulate an optimization problem to minimize the total transmit power with optimal precoder designs for the three aforementioned scenarios, under constraints on minimum signal-to-interference-plus-noise ratio and harvested energy by the users with respective demands. The problem may be adapted to the well-known semi-definite program, which can be typically solved via relaxation of rank-1 constraint. However, the relaxation of this constraint may in some cases lead to performance degradation, which increases with the rank of the solution obtained from the relaxed problem. Hence, we develop a novel technique motivated by the feasible-point pursuit and successive convex approximation method in order to address the rank-related issue. The benefits of the proposed method are illustrated under various operating conditions and parameter values, with comparison between the three above-mentioned scenarios. [less ▲]

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See detailEnhancing CoAP Group Communication to Support mMTC Over Satellite Networks
Soua, Ridha UL; Palattella, Maria Rita UL; Stemper, André UL et al

in IEEE International Conference on Communications (ICC) (2020, June)

Massive MTC (mMTC) is one of the application scenarios that upcoming 5G networks are expected to support. Satellites come into play in mMTC to complement and extend terrestrial networks in under-served ... [more ▼]

Massive MTC (mMTC) is one of the application scenarios that upcoming 5G networks are expected to support. Satellites come into play in mMTC to complement and extend terrestrial networks in under-served areas, where several services can benefit from the adoption of a group communication model. The IETF has specifically standardized the usage of CoAP group communication. However, CoAP responses are still sent in unicast from each single CoAP server to the CoAP client, which results in a substantial traffic load. Such problem becomes more severe in integrated IoT-Satellite networks given the limited bandwidth of the satellite return channel and the large number of IoT devices in a mMTC scenario. To reduce network traffic overhead in group communication and improve the network responsiveness, this paper proposes an aggregation scheme for the CoAP group communication in combination with Observer pattern and proxying. Results obtained by using the openSAND emulator and CoAPthon library corroborate the merit of our optimization in terms of overhead reduction and delay. [less ▲]

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See detailGOING DEEPER WITH NEURAL NETWORKS WITHOUT SKIP CONNECTIONS
Oyedotun, Oyebade UL; Shabayek, Abd El Rahman UL; Aouada, Djamila UL et al

in IEEE International Conference on Image Processing (ICIP 2020), Abu Dhabi, UAE, Oct 25–28, 2020 (2020, May 30)

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See detailBoosting SWIPT via Symbol-Level Precoding
Gautam, Sumit UL; Krivochiza, Jevgenij UL; Haqiqatnejad, Alireza UL et al

Scientific Conference (2020, May 29)

In this paper, we investigate a simultaneous wireless information and power transmission (SWIPT) system, wherein a single multi-antenna transmitter serves multiple single-antenna users which employ the ... [more ▼]

In this paper, we investigate a simultaneous wireless information and power transmission (SWIPT) system, wherein a single multi-antenna transmitter serves multiple single-antenna users which employ the power-splitting (PS) receiver architecture. We formulate a Symbol-Level Precoding (SLP) based transmit power minimization problem dependent on the minimum signal-to-interference-plus-noise ratio (SINR) and energy harvesting (EH) thresholds. We solve the corresponding non-negative convex quadratic optimization problem per time frame of transmitted symbols and study the benefits of proposed design under Zero-Forcing (ZF) Precoding, Direct Demand SLP (DD-SLP), and Squared-Root Demand SLP (RD-SLP) techniques. A static PS-ratio is fixed according to the SINR and EH demands to enable the segregation of intended received signals for information decoding (ID) and EH, respectively. Numerical results show the property conservation of SINR-enhancement via SLP at the ID unit while increasing the harvested energy at each of the end-users. [less ▲]

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See detailZur Bedeutsamkeit des Sportunterrichtes: Der Einfluss der Motivation im Sportunterricht auf den außerschulischen Kontext - ein longitudinaler Ansatz
Hutmacher, Djenna UL; Eckelt, Melanie UL; Bund, Andreas UL et al

Scientific Conference (2020, May 22)

Hintergrund: Hinsichtlich der kontinuierlichen Abnahme der körperlichen Aktivität von Kindern und Jugendlichen, rückt die Stärkung der Motivation als Ansatz zur Sportaktivierung immer mehr in den Fokus ... [more ▼]

Hintergrund: Hinsichtlich der kontinuierlichen Abnahme der körperlichen Aktivität von Kindern und Jugendlichen, rückt die Stärkung der Motivation als Ansatz zur Sportaktivierung immer mehr in den Fokus (Standage, Duda, & Ntoumanis, 2005). In ihrem trans-kontextuellen Modell postulieren Hagger und Chatzisarantis (2016) einen Zusammenhang zwischen intrinsischer Motivation im Sportunterricht und in der Freizeit. Dabei spielt die Unterstützung der Bedürfnisse durch die Sportlehrkraft eine wichtige Rolle, um die intrinsische Motivation der SchülerInnen im Sportunterricht und längerfristig in der Freizeit zu fördern, welche ein selbstbestimmtes körperliches Aktivitätsverhalten begünstigen soll. In der vorliegenden Studie wurden diese Annahmen in erweiterter Form im Längsschnitt geprüft. Methode: Es wurden N = 1681 SchülerInnen zwischen 10 und 23 Jahren (M = 14.7 Jahre; 50.7% weiblich) aus 14 luxemburgischen Schulen zu Beginn des Schuljahres (t1) und sechs Monate später am Ende des Schuljahres (t2) getestet. Neben der wahrgenommenen Bedürfnisunterstützung (Standage, Duda, & Ntoumanis, 2005) wurden die Motivationsregulation im Sportunterricht (PLOC-R; Vlachopoulos, Katartzi, Kontou, Moustaka, & Goudas, 2011) und in der Freizeit (BREQ-II; Markland & Tobin, 2004), sowie alle Konstrukte der Theorie des geplanten Handelns (Ajzen, 1991), und die körperliche Aktivität erhoben. Ergebnisse: Cross-Lagged-Panel Analysen zeigen, dass die intrinsische Motivation im Sportunterricht (t1) kontextübergreifend die intrinsische Motivation zur körperlichen Aktivität in der Freizeit (t2) vorhersagt (β = .12, p < .05). Selbiger Befund konnte auch für die Amotivation gefunden werden (β = .15, p < .05). Allerdings wurde kein kontextübergreifender Zusammenhang der extrinsischen Motivation gefunden (p > .05). Entgegen der postulierten Richtung des Modells, sagt eine höhere intrinsische Motivation der SchülerInnen (t1) eine höhere Wahrnehmung der Unterstützung der Grundbedürfnisse durch den Sportlehrer (t2) vorher (β = .10, p < .05). Die intrinsische Motivation in der Freizeit (t1) hängt zudem mit der Einstellung (β = .24, p < .05), subjektiven Norm (β = .11, p < .05), wahrgenommenen Verhaltenskontrolle (β = .12, p < .05), Intention (β = .16, p < .05) und der körperlichen Aktivität (β = .18, p < .05) zu t2 zusammen. Schlussfolgerung: Die Befunde bestätigen die Bedeutsamkeit des Sportunterrichts in dem Sinne, dass die intrinsische Motivation im Sportunterricht die Wahrnehmung der Bedürfnisunterstützung des Sportlehrers erhöht und kontextübergreifend mit der intrinsischen Motivation im Freizeitbereich zusammenhängt, welche wiederum ein selbstbestimmtes körperliches Aktivitätsverhalten in der Freizeit positiv bedingt. Eine Interventionsstudie im Sportunterricht bekräftigt diese Befunde in dem Sinne, dass die Autoren positivere Effekte fanden, wenn, zusätzlich zur alleinigen Autonomieunterstützung, internale Zielsetzungen in der Lehre eingesetzt wurden (Cheon, Reeve, & Song, 2019). [less ▲]

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See detailFlucht- und Wanderungsbewegungen in Ostbelgien 1944/45
Brüll, Christoph UL

Scientific Conference (2020, May 13)

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See detailClimate SMART Agriculture: How well does the agricultural sector in Luxembourg perform in terms of climate change?
Evelyne, Stoll; Schader, Christian; Bohn, Torsten et al

Scientific Conference (2020, May 04)

In Luxembourg, the agricultural sector was responsible for 711.7 Gg CO2-equivalents in 2016, which corresponds to 6.95 % of the total country greenhouse gas (GHG) emissions. Over 50 % of the farms are ... [more ▼]

In Luxembourg, the agricultural sector was responsible for 711.7 Gg CO2-equivalents in 2016, which corresponds to 6.95 % of the total country greenhouse gas (GHG) emissions. Over 50 % of the farms are specialist grazing livestock farms. The beef and cattle milk production account globally together for over 60 % of the sector’s global emissions. Thus, the climate impact of the whole agricultural sector in Luxembourg can be significantly lowered by reducing the GHG emissions of the specialist grazing livestock sector. However, beyond farm type, the GHG emissions of a farm are also influenced by other factors, such as management systems and farming practices. To enable a transition towards a more climate-positive agriculture, insights into the sustainability performance in terms of climate change are needed. The aim of this study is to determine the current sustainability performance of the Luxembourgish specialist grazing livestock sector in terms of climate change. The climate impact of the different specialist grazing livestock farm types (OTE (orientation technico-économique) 45 - Specialist dairying; OTE 46 - Specialist cattle - rearing and fattening and OTE 47 - Cattle - dairying, rearing and fattening combined) and of different management systems (conventional or organic) was assessed at farm-level. Furthermore, the relationship between the sustainability performance in terms of climate change and other areas of sustainability is being studied. Farming practices of 60 farms typical for Luxembourg in regard to their share of arable land and permanent grassland (OTE 45: 3 farms; OTE 46: 15; OTE 45: 11; Conventional: 44; Organic: 16) and their respective sustainability implications were assessed in 2019 according to the FAO SAFA Guidelines (Guidelines for the Sustainability Assessment of Food and Agriculture Systems, 2014) using the Sustainability Monitoring and Assessment RouTine (SMART)-Farm Tool (v5.0). Organic farms were highly overrepresented, with 26.7 % in the sample compared to 5 % of all Luxembourgish farms. The data was collected during a farm visit and a 3 h interview with the farm manager. The impact of management system and farm type on the SAFA-goal achievement for the sub-theme Greenhouse Gases (GHG) were studied. The results show that the sustainability performances of the participating farms were moderate to good. Goal achievement for the sub-theme GHG was moderate and did not differ significantly between the three farm types (OTE 45: 53.3 % ±3.9 SD goal achievement; OTE 46: 55.6 % ±7.3 SD; OTE 47: 54.6 % ±6.9 SD). Organic farms showed a significantly higher mean goal achievement for GHG than conventional farms (p-value < 0.001) (organic: 58.3 % ±6.0 SD; conventional: 52.6 % ±4.4 SD). For indicators positively impacting GHG, the organic and the OTE 46 farms had generally higher ratings. Correlations between GHG and the other sub-themes were mainly in the Environmental Integrity dimension, showing that implementing climate-positive farming practices can also improve other ecological aspects. The indicator analysis identified the following linchpins: increase in protein autarky, closing of farming cycles and holistic approach with strategic decision making leading to harmonized actions towards a sustainable and climate positive farming system. [less ▲]

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See detailAn Annotation Framework for Luxembourgish Sentiment Analysis
Sirajzade, Joshgun UL; Gierschek, Daniela UL; Schommer, Christoph UL

in Besacier, Laurent; Sakti, Sakriani; Soria, Claudia (Eds.) et al Proceedings of the LREC 2020 1st Joint SLTU and CCURL Workshop (SLTU-CCURL 2020) (2020, May)

The aim of this paper is to present a framework developed for crowdsourcing sentiment annotation for the low-resource language Luxembourgish. Our tool is easily accessible through a web interface and ... [more ▼]

The aim of this paper is to present a framework developed for crowdsourcing sentiment annotation for the low-resource language Luxembourgish. Our tool is easily accessible through a web interface and facilitates sentence-level annotation of several annotators in parallel. In the heart of our framework is an XML database, which serves as central part linking several components. The corpus in the database consists of news articles and user comments. One of the components is LuNa, a tool for linguistic preprocessing of the data set. It tokenizes the text, splits it into sentences and assigns POS-tags to the tokens. After that, the preprocessed text is stored in XML format into the database. The Sentiment Annotation Tool, which is a browser-based tool, then enables the annotation of split sentences from the database. The Sentiment Engine, a separate module, is trained with this material in order to annotate the whole data set and analyze the sentiment of the comments over time and in relationship to the news articles. The gained knowledge can again be used to improve the sentiment classification on the one hand and on the other hand to understand the sentiment phenomenon from the linguistic point of view. [less ▲]

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See detailProceedings of the 6th Global Conference on Artificial Intelligence (GCAI 2020)
Danoy, Grégoire UL; Pang, Jun UL; Sutcliffe

in 6th Global Conference on Artificial Intelligence (2020, May)

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See detailComponent Analysis of Adjectives in Luxembourgish for Detecting Sentiments
Sirajzade, Joshgun UL; Gierschek, Daniela UL; Schommer, Christoph UL

in Beermann, Dorothee; Besacier, Laurent; Sakti, Sakriani (Eds.) et al Proceedings of the LREC 2020 1st Joint SLTU and CCURL Workshop(SLTU-CCURL 2020) (2020, May)

The aim of this paper is to investigate the role of Luxembourgish adjectives in expressing sentiments in user comments written at the web presence of rtl.lu (RTL is the abbreviation for Radio Television ... [more ▼]

The aim of this paper is to investigate the role of Luxembourgish adjectives in expressing sentiments in user comments written at the web presence of rtl.lu (RTL is the abbreviation for Radio Television Lëtzebuerg). Alongside many textual features or representations, adjectives could be used in order to detect sentiment, even on a sentence or comment level. In fact, they are also by themselves one of the best ways to describe a sentiment, despite the fact that other word classes such as nouns, verbs, adverbs or conjunctions can also be utilized for this purpose. The empirical part of this study focuses on a list of adjectives that were extracted from an annotated corpus. The corpus contains the part of speech tags of individual words and sentiment annotation on the adjective, sentence, and comment level. Suffixes of Luxembourgish adjectives like -esch, -eg, -lech, -al, -el, -iv, -ent, -los, -bar and the prefix on- were explicitly investigated, especially by paying attention to their role in regards to building a model by applying classical machine learning techniques. We also considered the interaction of adjectives with other grammatical means, especially other part of speeches, e.g. negations, which can completely reverse the meaning, thus the sentiment of an utterance. [less ▲]

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See detailOn the Efficiency of Test Suite based Program Repair: A Systematic Assessment of 16 Automated Repair Systems for Java Programs
Liu, Kui UL; Wang, Shangwen; Koyuncu, Anil UL et al

in 42nd ACM/IEEE International Conference on Software Engineering (ICSE) (2020, May)

Test-based automated program repair has been a prolific field of research in software engineering in the last decade. Many approaches have indeed been proposed, which leverage test suites as a weak, but ... [more ▼]

Test-based automated program repair has been a prolific field of research in software engineering in the last decade. Many approaches have indeed been proposed, which leverage test suites as a weak, but affordable, approximation to program specifications. Although the literature regularly sets new records on the number of benchmark bugs that can be fixed, several studies increasingly raise concerns about the limitations and biases of state-of-the-art approaches. For example, the correctness of generated patches has been questioned in a number of studies, while other researchers pointed out that evaluation schemes may be misleading with respect to the processing of fault localization results. Nevertheless, there is little work addressing the efficiency of patch generation, with regard to the practicality of program repair. In this paper, we fill this gap in the literature, by providing an extensive review on the efficiency of test suite based program repair. Our objective is to assess the number of generated patch candidates, since this information is correlated to (1) the strategy to traverse the search space efficiently in order to select sensical repair attempts, (2) the strategy to minimize the test effort for identifying a plausible patch, (3) as well as the strategy to prioritize the generation of a correct patch. To that end, we perform a large-scale empirical study on the efficiency, in terms of quantity of generated patch candidates of the 16 open-source repair tools for Java programs. The experiments are carefully conducted under the same fault localization configurations to limit biases. Eventually, among other findings, we note that: (1) many irrelevant patch candidates are generated by changing wrong code locations; (2) however, if the search space is carefully triaged, fault localization noise has little impact on patch generation efficiency; (3) yet, current template-based repair systems, which are known to be most effective in fixing a large number of bugs, are actually least efficient as they tend to generate majoritarily irrelevant patch candidates. [less ▲]

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See detailSecurity and Performance Implications of BGP Rerouting-resistant Guard Selection Algorithms for Tor
Mitseva, Asya UL; Aleksandrova, Marharyta UL; Engel, Thomas UL et al

in Security and Performance Implications of BGP Rerouting-resistant Guard Selection Algorithms for Tor (2020, May)

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See detailPerformance Analysis of Distributed and Scalable Deep Learning
Mahon, S.; Varrette, Sébastien UL; Plugaru, Valentin UL et al

in 20th IEEE/ACM Intl. Symp. on Cluster, Cloud and Internet Computing (CCGrid'20) (2020, May)

With renewed global interest for Artificial Intelligence (AI) methods, the past decade has seen a myriad of new programming models and tools that enable better and faster Machine Learning (ML). More ... [more ▼]

With renewed global interest for Artificial Intelligence (AI) methods, the past decade has seen a myriad of new programming models and tools that enable better and faster Machine Learning (ML). More recently, a subset of ML known as Deep Learning (DL) raised an increased interest due to its inherent ability to tackle efficiently novel cognitive computing applications. DL allows computational models that are composed of multiple processing layers to learn in an automated way representations of data with multiple levels of abstraction, and can deliver higher predictive accuracy when trained on larger data sets. Based on Artificial Neural Networks (ANN), DL is now at the core of state of the art voice recognition systems (which enable easy control over e.g. Internet-of- Things (IoT) smart home appliances for instance), self-driving car engine, online recommendation systems. The ecosystem of DL frameworks is fast evolving, as well as the DL architectures that are shown to perform well on specialized tasks and to exploit GPU accelerators. For this reason, the frequent performance evaluation of the DL ecosystem is re- quired, especially since the advent of novel distributed training frameworks such as Horovod allowing for scalable training across multiple computing resources. In this paper, the scalability evaluation of the reference DL frameworks (Tensorflow, Keras, MXNet, and PyTorch) is performed over up-to-date High Performance Comput- ing (HPC) resources to compare the efficiency of differ- ent implementations across several hardware architectures (CPU and GPU). Experimental results demonstrate that the DistributedDataParallel features in the Pytorch library seem to be the most efficient framework for distributing the training process across many devices, allowing to reach a throughput speedup of 10.11 when using 12 NVidia Tesla V100 GPUs when training Resnet44 on the CIFAR10 dataset. [less ▲]

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See detailSDN-based Misbehavior Detection System for Vehicular Networks
Boualouache, Abdelwahab UL; Soua, Ridha UL; Engel, Thomas UL

in 2020 IEEE 91st Vehicular Technology Conference (VTC2020-Spring) (2020, May)

Vehicular networks are vulnerable to a variety of internal attacks. Misbehavior Detection Systems (MDS) are preferred over the cryptography solutions to detect such attacks. However, the existing ... [more ▼]

Vehicular networks are vulnerable to a variety of internal attacks. Misbehavior Detection Systems (MDS) are preferred over the cryptography solutions to detect such attacks. However, the existing misbehavior detection systems are static and do not adapt to the context of vehicles. To this end, we exploit the Software-Defined Networking (SDN) paradigm to propose a context-aware MDS. Based on the context, our proposed system can tune security parameters to provide accurate detection with low false positives. Our system is Sybil attack-resistant and compliant with vehicular privacy standards. The simulation results show that, under different contexts, our system provides a high detection ratio and low false positives compared to a static MDS. [less ▲]

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See detailPlay the Pain Away: Pain Regulation and Attention in Virtual Reality
Holl, Elisabeth UL; Rischer, Katharina Miriam UL; Battistutta, Layla UL et al

Scientific Conference (2020, May)

Virtual reality (VR) has been shown to be a powerful method to divert attention away from pain (Malloy & Milling, 2010). In an ongoing study (data collection will be finished in late December 2019 ... [more ▼]

Virtual reality (VR) has been shown to be a powerful method to divert attention away from pain (Malloy & Milling, 2010). In an ongoing study (data collection will be finished in late December 2019) healthy participants play the VR game Subnautica in two conditions (high vs. low cognitive load). Pain thresholds and psychophysiological measures are assessed during play to measure the distraction effect. Additionally, pain management will be compared to individual executive functions and attention investigated before playing. [less ▲]

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See detailDeep Learning for Beam Hopping in Multibeam Satellite Systems
Lei, Lei UL; Lagunas, Eva UL; Yuan, Yaxiong UL et al

in IEEE 91st Vehicular Technology Conference (VTC2020-Spring) (2020, May)

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See detail'Faster-than-Nyquist Signaling via Spatiotemporal Symbol-Level Precoding for Multi-User MISO Redundant Transmissions
Alves Martins, Wallace UL; Spano, Danilo UL; Chatzinotas, Symeon UL et al

in International Conference on Acoustics, Speech, and Signal Processing (ICASSP-2020), Barcelona 4-8 May 2020 (2020, May)

This paper tackles the problem of both multi-user and intersymbol interference stemming from co-channel users transmitting at a faster-than-Nyquist (FTN) rate in multi-antenna downlink transmissions. We ... [more ▼]

This paper tackles the problem of both multi-user and intersymbol interference stemming from co-channel users transmitting at a faster-than-Nyquist (FTN) rate in multi-antenna downlink transmissions. We propose a framework for redundant block-based symbol-level precoders enabling the trade-off between constructive and destructive multi-user and interblock interference (IBI) effects at the single-antenna user terminals. Redundant elements are added as guard interval to handle IBI destructive effects. It is shown that, within this framework, accelerating the transmissions via FTN signaling improves the error-free spectral efficiency, up to a certain acceleration factor beyond which the transmitted information cannot be perfectly recovered by linear filtering followed by sampling. Simulation results corroborate that the proposed spatiotemporal symbol-level precoding can change the amount of added redundancy from zero (full IBI) to half (IBI-free) the equivalent channel order, so as to achieve a target balance between spectral and energy efficiencies. [less ▲]

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See detailDynamic Adaptation of Software-defined Networks for IoT Systems: A Search-based Approach
Shin, Seung Yeob UL; Nejati, Shiva UL; Sabetzadeh, Mehrdad UL et al

in Proceedings of the 15th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS'20) (2020, May)

The concept of Internet of Things (IoT) has led to the development of many complex and critical systems such as smart emergency management systems. IoT-enabled applications typically depend on a ... [more ▼]

The concept of Internet of Things (IoT) has led to the development of many complex and critical systems such as smart emergency management systems. IoT-enabled applications typically depend on a communication network for transmitting large volumes of data in unpredictable and changing environments. These networks are prone to congestion when there is a burst in demand, e.g., as an emergency situation is unfolding, and therefore rely on configurable software-defined networks (SDN). In this paper, we propose a dynamic adaptive SDN configuration approach for IoT systems. The approach enables resolving congestion in real time while minimizing network utilization, data transmission delays and adaptation costs. Our approach builds on existing work in dynamic adaptive search-based software engineering (SBSE) to reconfigure an SDN while simultaneously ensuring multiple quality of service criteria. We evaluate our approach on an industrial national emergency management system, which is aimed at detecting disasters and emergencies, and facilitating recovery and rescue operations by providing first responders with a reliable communication infrastructure. Our results indicate that (1) our approach is able to efficiently and effectively adapt an SDN to dynamically resolve congestion, and (2) compared to two baseline data forwarding algorithms that are static and non-adaptive, our approach increases data transmission rate by a factor of at least 3 and decreases data loss by at least 70%. [less ▲]

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See detailUnderstanding Moral Decision-Making in Video Games: A Focus Group Study
Holl, Elisabeth UL; Bernard, Steve UL; Melzer, André UL

Scientific Conference (2020, May)

Moral dilemmas have become increasingly popular in video games, although it is still widely unknown why players might find them pleasurable, how they process dilemmas, and which factors affect the ... [more ▼]

Moral dilemmas have become increasingly popular in video games, although it is still widely unknown why players might find them pleasurable, how they process dilemmas, and which factors affect the processing. Therefore, three different focus groups sessions with expert gamers (N = 16) were conducted. Gamers’ expressions of their experience with meaningful and morally relevant game situations were grouped for relevant topics. Topics are supported by direct quotations from participants of discussion groups, referring to up-to-date video game titles and presented together with respective theoretical assumptions. Results show that besides the game-defining theme of interactivity, statements can be grouped broadly into factors that describe why players engage or disengage in the first place (motivation) and factors that shape the moral interaction itself (influencing factors). In summary, our findings support the notion that moral-decision making in video games is a dynamic interplay between several game and user-dependent variables. Findings provide insights into players’ processing of moral dilemmas in video games, which also offers promising suggestions for future research using experimental setups. [less ▲]

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See detailTransmit Beamforming Design with Received-Interference Power Constraints: The Zero-Forcing Relaxation
Lagunas, Eva UL; Perez-Neira, Ana; Lagunas, Miguel Angel et al

in IEEE Int. Conf. on Acoustics, Speech, and Signal Processing (ICASSP), Barcelona, Spain, May 2020 (2020, May)

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See detailBacAnalytics: A Tool to Support Secondary School Examination in France
Roussanaly, Azim; Aleksandrova, Marharyta UL; Boyer, Anne

in 25th International Symposium on Intelligent Systems (ISMIS 2020) (2020, May)

Students who failed the final examination in the secondary school in France (known as baccalauréat or baccalaureate) can improve their scores by passing a remedial test. This test consists of two oral ... [more ▼]

Students who failed the final examination in the secondary school in France (known as baccalauréat or baccalaureate) can improve their scores by passing a remedial test. This test consists of two oral examinations in two subjects of the student's choice. Students announce their choice on the day of the remedial test. Additionally, the secondary education system in France is quite complex. There exist several types of baccalaureate consisting of various streams. Depending upon the stream students belong to, they have different subjects allowed to be taken during the remedial test and different coefficients associated with each of them. In this context, it becomes difficult to estimate the number of professors of each subject required for the examination. Thereby, the general practice of remedial test organization is to mobilize a large number of professors. In this paper, we present BacAnalytics - a tool that was developed to assist the rectorate of secondary schools with the organization of remedial tests for the baccalaureate. Given profiles of students and their choices of subjects for previous years, this tool builds a predictive model and estimates the number of required professors for the current year. In the paper, we present the architecture of the tool, analyze its performance, and describe its usage by the rectorate of the Academy of Nancy-Metz in Grand Est region of France in the years 2018 and 2019. BacAnalytics achieves almost 100% of prediction accuracy with approximately 25% of redundancy and was awarded a French national prize Impulsions 2018. [less ▲]

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See detailConstcamer Paintings as Epistemic Images: Early Modern Theaters of Wisdom
Koeleman, Floor UL

Scientific Conference (2020, April 04)

This paper argues, against existing literature, that 17th-cent. constcamer paintings were objects to think with, functioning as the two-dimensional space of artificial memory. In turn, these artworks ... [more ▼]

This paper argues, against existing literature, that 17th-cent. constcamer paintings were objects to think with, functioning as the two-dimensional space of artificial memory. In turn, these artworks complicate conventional definitions of epistemic images more broadly. I focus on an analysis of constcamer paintings accounting for the reception of the ancients and the mnemonic and propaedeutic role of images, entailing concepts such as wonder or thauma (from Greek θεάομαι), the drive to gather knowledge, memory as the locus of this ‘collection’, and recollecting as the intellectual process of interaction with memorized knowledge. The term inventor, referring to the creator of a given collection, is derived from the rhetorical technique for the retrieval of information. The theatre or ‘place for viewing’ provided the physical context for the collected wisdom. Inventors of constcamer paintings – often artists themselves – vitally participated in knowledge formation contributing to contemporary intellectual debates. [less ▲]

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See detailDoes Conscientiousness Matter for Academic Success? Considering Different Facets of Conscientiousness and Different Educational Outcomes
Franzen, Patrick UL; van der Westhuizen, Lindie UL; Arens, A. Katrin et al

Poster (2020, April)

Conscientiousness is the strongest BIG-5 predictor of academic success. Both conscientiousness and academic success are broad concepts, consisting of multiple lower level facets. Conscientiousness facets ... [more ▼]

Conscientiousness is the strongest BIG-5 predictor of academic success. Both conscientiousness and academic success are broad concepts, consisting of multiple lower level facets. Conscientiousness facets might display differential relations to different indicators of academic success. To investigate these relations, conscientiousness facets need to be measured in an economic and valid way. We conducted two studies, validating a short conscientiousness scale measuring seven facets of conscientiousness (Industriousness, Task Planning, Perfectionism, Procrastination Refrainment, Tidiness, Control, Cautiousness), and testing the relations of these facets with GPA, test scores, school satisfaction, and engagement. The results supported the validity of the scale. Industriousness, Perfectionism, and Cautiousness revealed the highest relations to academic outcomes. GPA and test scores showed differential associations with the different conscientiousness facets. [less ▲]

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See detailLOVBench: Ontology Ranking Benchmark
Kolbe, Niklas UL; Vandenbussche, Pierre-Yves; Kubler, Sylvain UL et al

in Proceedings of The Web Conference 2020 (WWW '20) (2020, April)

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See detailNeuere Methoden zur Identifikation und Lokalisierung von Schäden an vorgespannten Betonbrücken
Maas, Stefan UL; Nguyen, Viet Ha UL; Kebig, Tanja UL

in Bischoff, Manfred; von Scheven, Malte; Oesterle, Bernd (Eds.) Baustatik-Baupraxis 14 (2020, March 23)

Zuerst wird ein rein statistischer Schadensindikator basierend auf der Hauptkomponentenanalyse vorgestellt. Wichtig sind Referenzmessungen im ungeschädigten Zustand, um Veränderungen zu identifizieren ... [more ▼]

Zuerst wird ein rein statistischer Schadensindikator basierend auf der Hauptkomponentenanalyse vorgestellt. Wichtig sind Referenzmessungen im ungeschädigten Zustand, um Veränderungen zu identifizieren. Bevor die Messdaten mit den Rechenmodellen kombiniert werden, müssen Temperatureffekte kompensiert werden, um dann die Schäden zu erkennen und zu lokalisieren. Ein „Model-Updating“ Prozess eines speziellen Finite-Elemente- Modells passt die Steifigkeitsmatrix an die gemessenen Eigenfrequenzen oder an die progressive Absenkung unter Eigengewicht an. [less ▲]

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See detailMensch-Roboter-Kollaboration in der Domäne Refabrikation – State-of-the-Art und Ausblick
Groß, Sebastian UL; Gerke, Wolfgang; Plapper, Peter UL

in Jäkel, Jens; Thiel, Robert (Eds.) Tagungsband AALE 2020 Automatisierung und Mensch-Technik-Interaktion (2020, March 05)

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See detailAgentenbasierte, hybride Steuerungsarchitektur für cyberphysische Refabrikationssysteme
Groß, Sebastian UL; Gerke, Wolfgang; Plapper, Peter UL

in Jäkel, Jens; Thiel, Robert (Eds.) Tagungsband AALE 2020 Automatisierung und Mensch-Technik-Interaktion (2020, March 05)

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See detailStructured Compression of Deep Neural Networks with Debiased Elastic Group LASSO
Oyedotun, Oyebade UL; Aouada, Djamila UL; Ottersten, Björn UL

in IEEE 2020 Winter Conference on Applications of Computer Vision (WACV 20), Aspen, Colorado, US, March 2–5, 2020 (2020, March 01)

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See detailAnalyzing PeerFlow -- A Bandwidth Estimation System for Untrustworthy Environments
Mitseva, Asya UL; Engel, Thomas UL; Panchenko, Andriy

in Analyzing PeerFlow -- A Bandwidth Estimation System for Untrustworthy Environments (2020, March)

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See detailTowards an Executable Methodology for the Formalization of Legal Texts
Libal, Tomer UL; Steen, Alexander UL

in Dastani, Mehdi; Dong, Huimin; van der Torre, Leon (Eds.) Logic and Argumentation. CLAR 2020 (2020, March)

A methodology for the formalization of legal texts is presented. This methodology is based on features of the NAI Suite, a recently developed formalization environment for legal texts. The ability of the ... [more ▼]

A methodology for the formalization of legal texts is presented. This methodology is based on features of the NAI Suite, a recently developed formalization environment for legal texts. The ability of the tool to execute queries is used in order to drive a correct formalization until all queries are validated. The approach is studied on a fragment of the Smoking Prohibition (Children in Motor Vehicles) (Scotland) Act 2016 of the Scottish Parliament. [less ▲]

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See detailInvestigating the role of individual differences in the analgesic response to a virtual reality game: An exploratory analysis (accepted submission, but symposium was cancelled due to COVID-19)
Rischer, Katharina Miriam UL; Barcatta, Katharina UL; Battistutta, Layla UL et al

Scientific Conference (2020, March)

Virtual reality (VR) has been shown to be a powerful method of redirecting attention away from pain and is increasingly used in clinical settings as a therapeutic tool for pain treatment. Yet, little is ... [more ▼]

Virtual reality (VR) has been shown to be a powerful method of redirecting attention away from pain and is increasingly used in clinical settings as a therapeutic tool for pain treatment. Yet, little is known about the underlying factors that modulate the size of the analgesic response to a VR game, such as task difficulty and inter-individual differences in pain attitude, emotion regulation habits, executive functions and virtual reality experience. Methods: 101 healthy participants played two versions of the VR game Subnautica, differing in cognitive load (low load vs. high load). In the low load condition, participants navigated along a predefined route. In the high load condition, participants additionally memorized a series of single digits presented along the route. Pain heat thresholds as well as psychophysiological measures (ECG, EDA) were recorded during a resting state period prior to, as well as during, the two VR playing sessions. In addition, participants completed several psychological questionnaires and different executive functioning tasks (Corsi block tapping task, flanker task, go/nogo task) prior to the VR sessions. Results: Preliminary results of a subgroup (N = 66) of the total sample revealed that pain thresholds were significantly higher for the VR playing sessions when compared to the resting state period, with a trend of a higher threshold for the high load condition. Moreover, pain catastrophizing and fear of pain were significant predictors of pain threshold measurements. The complete results will be presented at the symposium. Discussion: Results could shed light on the role of inter-individual differences on the efficacy of VR-based distraction from pain, and potentially elucidate factors that render an individual more likely to benefit from VR as a pain-relieving tool. This may have important consequences for the use of VR as a therapeutic treatment for pain patients. [less ▲]

Detailed reference viewed: 33 (3 UL)
Peer Reviewed
See detailLangzeiteffekte von Klassenwiederholungen in der Sekundarstufe
Klapproth, Florian; Keller, Ulrich UL; Fischbach, Antoine UL

Scientific Conference (2020, March)

Detailed reference viewed: 19 (1 UL)