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See detail‘Pas de fraises pour Noël’. Le rôle de la régionalité locavore dans la (re)prise de conscience de la saisonnalité des aliments 
Reckinger, Rachel UL

in Adamiec, Camille; Julien, Marie-Pierre; Régnier, Faustine (Eds.) L’alimentation au fil des saisons. La saisonnalité des pratiques alimentaires (2018)

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See detailThe Metonymical Institutionnalisation of Wine Production and Consumption in Luxembourg. Convergence of Terroir Typicity, Political Symbolism, Regulations and Scientific Knowledge
Reckinger, Rachel UL

in Tedeschi, Paolo (Ed.) The Evolution of the Viticulture and Winemaking in Europe: Production, Retail System, Oenological Techniques, Terroir and Local Culture (19th-20th Centuries) (2018)

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See detailLe rapport Werner en suspens. Les débats autour de l'Union économique et monétaire en 1973
Danescu, Elena UL

in Wilkens, Andreas (Ed.) Une année particulière: 1973 et les tourments de l'Europe (2018)

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See detailTowards the Systematic Analysis of Non-Functional Properties in Model-Based Engineering for Real-Time Embedded Systems
Brau, Guillaume UL; Navet, Nicolas UL; Hugues, Jérôme

in Science of Computer Programming (2018), 156

The real-time scheduling theory provides analytical methods to assess the temporal predictability of embedded systems. Nevertheless, their use is limited in a Model-Based Systems Engineering approach. In ... [more ▼]

The real-time scheduling theory provides analytical methods to assess the temporal predictability of embedded systems. Nevertheless, their use is limited in a Model-Based Systems Engineering approach. In fact, the large number of applicability conditions makes the use of real-time scheduling analysis tedious and error-prone. Key issues are left to the engineers: when to apply a real-time scheduling analysis? What to do with the analysis results?} This article presents an approach to systematize and then automate the analysis of non-functional properties in Model-Based Systems Engineering. First, preconditions and postconditions define the applicability of an analysis. In addition, contracts specify the analysis interfaces, thereby enabling to reason about the analysis process. We present a proof-of-concept implementation of our approach using a combination of constraint languages (REAL for run-time analysis) and specification languages (Alloy for describing interfaces and reasoning about them). This approach is experimented on architectural models written with the Architecture Analysis and Design Language (AADL). [less ▲]

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See detailRobert Triffin, a 'personal equation'
Danescu, Elena UL

in The Journal of European Economic History (2018)

Robert Triffin (1911-1993), a Belgian-born economist who spent much of his career in America, had a major influence on 20th-century economic thinking. He is particularly known for his monetary approach ... [more ▼]

Robert Triffin (1911-1993), a Belgian-born economist who spent much of his career in America, had a major influence on 20th-century economic thinking. He is particularly known for his monetary approach. His intellectual legacy revolves ariund the 'Triffin dilemma' or 'Triffin paradox'. Triffin accurately predicted the end of the Bretton Woods system, though not for the right reasons. Triffin stuck by his monetary theory that it was much harder to achieve sound international economic management with flexible exchange rates and that best practices were by no means a guarantee of global stability if they were not accompanied by genuine international coordination. Triffin was also a committed European. He was close to Jean Monnet and Pierre Werner and worked alongside them from the early 1960's onwards in favour of European monetary integration. [less ▲]

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See detailComparative Study of Genetic and Discrete Firefly Algorithm for Combinatorial Optimization
Tessaro Lunardi, Willian UL; Voos, Holger UL

in 33rd ACM/SIGAPP Symposium On Applied Computing, Pau, France, April 9 - 13, 2018 (2018, April)

Flexible job-shop scheduling problem (FJSP) is one of the most challenging combinatorial optimization problems. FJSP is an extension of the classical job shop scheduling problem where an operation can be ... [more ▼]

Flexible job-shop scheduling problem (FJSP) is one of the most challenging combinatorial optimization problems. FJSP is an extension of the classical job shop scheduling problem where an operation can be processed by several different machines. The FJSP contains two sub-problems, namely machine assignment problem and operation sequencing problem. In this paper, we propose and compare a discrete firefly algorithm (FA) and a genetic algorithm (GA) for the multi-objective FJSP. Three minimization objectives are considered, the maximum completion time, workload of the critical machine and total workload of all machines. Five well-known instances of FJSP have been used to evaluate the performance of the proposed algorithms. Comparisons among our methods and state-of-the-art algorithms are also provided. The experimental results demonstrate that the FA and GA have achieved improvements in terms of efficiency. Solutions obtained by both algorithms are comparable to those obtained by algorithms with local search. In addition, based on our initial experiments, results show that the proposed discrete firefly algorithm is feasible, more effective and efficient than our proposed genetic algorithm for solving multi-objective FJSP. [less ▲]

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See detailDynamic interplay of language policy, beliefs and pedagogy in a nursery class in Luxembourg
Kirsch, Claudine UL

in Language and Education (2018)

This presentation focuses on the relationship between the language policy, language ideologies and language practices in a nursery class in trilingual Luxembourg. Individual multilingualism is an ... [more ▼]

This presentation focuses on the relationship between the language policy, language ideologies and language practices in a nursery class in trilingual Luxembourg. Individual multilingualism is an educational goal in Luxembourg, a small country in central Europe, and, thus, children learn Luxembourgish from the compulsory nursery school, become literate in German in Year 1 and learn oral and written French from Year 2 and Year 3, respectively. Currently, 62.4% of the children do not speak Luxembourgish on school entry (MENJE 2016). Many speak Portuguese, French or a language of the Balkans. As a result, educational policies focus on the teaching of Luxembourgish from preschool, sometimes at the expense of other languages. Gretsch and Kirsch (2015) developed the app iTEO in order to promote innovative teaching methods that capitalize on the children’s diverse language resources and that promote a dynamic view of bilingualism. This ipad app, which allows for the recording and editing of oral speech, was designed with social-constructivist theories and Bakhtin’s theory of dialogism in mind. This case-study presents the ways in which a preschool teacher’s ideological beliefs influence a child’s language use over a period of two years leading to the child’s understanding of the legitimacy of translanguaging. The focus lies on the interplay between the educational policy focusing on the teaching of Luxembourgish, the teacher’s language ideologies rooted in her multilingual identity and in societal multilingualism, and the child’s experiences of separating languages at home (Kirsch, 2014). The data stem from a qualitative, longitudinal study using a multi-method approach. The study shows that dialogue between teachers, parents, children, policy-makers and researchers can contribute to shifting ideologies and to opening up dynamic languaging spaces. [less ▲]

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See detailPerturbed path integrals in imaginary time: Efficiently modeling nuclear quantum effects in molecules and materials
Poltavskyi, Igor UL; DiStasio, Robert; Tkatchenko, Alexandre UL

in Journal of Chemical Physics (2018), 148(10), 102325

Nuclear quantum effects (NQE), which include both zero-point motion and tunneling, exhibit quite an impressive range of influence over the equilibrium and dynamical properties of molecules and materials ... [more ▼]

Nuclear quantum effects (NQE), which include both zero-point motion and tunneling, exhibit quite an impressive range of influence over the equilibrium and dynamical properties of molecules and materials. In this work, we extend our recently proposed perturbed path-integral (PPI) approach for modeling NQE in molecular systems [I. Poltavsky and A. Tkatchenko, Chem. Sci. 7, 1368 (2016)], which successfully combines the advantages of thermodynamic perturbation theory with path-integral molecular dynamics (PIMD), in a number of important directions. First, we demonstrate the accuracy, performance, and general applicability of the PPI approach to both molecules and extended (condensed-phase) materials. Second, we derive a series of estimators within the PPI approach to enable calculations of structural properties such as radial distribution functions (RDFs) that exhibit rapid convergence with respect to the number of beads in the PIMD simulation. Finally, we introduce an effective nuclear temperature formalism within the framework of the PPI approach and demonstrate that such effective temperatures can be an extremely useful tool in quantitatively estimating the “quantumness” associated with different degrees of freedom in the system as well as providing a reliable quantitative assessment of the convergence of PIMD simulations. Since the PPI approach only requires the use of standard second-order imaginary-time PIMD simulations, these developments enable one to include a treatment of NQE in equilibrium thermodynamic properties (such as energies, heat capacities, and RDFs) with the accuracy of higher-order methods but at a fraction of the computational cost, thereby enabling first-principles modeling that simultaneously accounts for the quantum mechanical nature of both electrons and nuclei in large-scale molecules and materials. [less ▲]

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See detailCharacterizations of idempotent discrete uninorms
Couceiro, Miguel; Devillet, Jimmy UL; Marichal, Jean-Luc UL

in Fuzzy Sets & Systems (2018), 334

In this paper we provide an axiomatic characterization of the idempotent discrete uninorms by means of three conditions only: conservativeness, symmetry, and nondecreasing monotonicity. We also provide an ... [more ▼]

In this paper we provide an axiomatic characterization of the idempotent discrete uninorms by means of three conditions only: conservativeness, symmetry, and nondecreasing monotonicity. We also provide an alternative characterization involving the bisymmetry property. Finally, we provide a graphical characterization of these operations in terms of their contour plots, and we mention a few open questions for further research. [less ▲]

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See detailThe Werner report and the financial crisis during the 1970s
Danescu, Elena UL; Tedeschi, Paolo

in Leboutte, René; Tedeschi, Paolo (Eds.) Euro changes: European Responses to Economics and Social Changes. From de 1970s to the new Millennium. (2018)

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See detailDe gevolgen van de restkracht bij een paalfundering
Rica, Shilton UL; Van Baars, Stefan UL

in Geotechniek (2018), Maart

Alhoewel de funderingspaal al lang in gebruik is, is de bepaling van de draagkracht nog steeds een complexe zaak. Uit een verzameling eerder gemaakte veldproeven, die in Nederland, België en Frankrijk ... [more ▼]

Alhoewel de funderingspaal al lang in gebruik is, is de bepaling van de draagkracht nog steeds een complexe zaak. Uit een verzameling eerder gemaakte veldproeven, die in Nederland, België en Frankrijk waren uitgevoerd, werd de conclusie getrokken dat het berekende puntdraagvermogen, per 2017, met 30% gereduceerd moest worden. Bij deze proeven werd verondersteld dat de spanningen op de onbelaste paal na installatie kunnen worden verwaarloosd, en daarmee ook de resulterende restkracht in de paal. Uit andere veldproeven genoemd in de wetenschappelijke literatuur, blijkt echter dat deze restkracht niet te verwaarlozen is. Numerieke berekeningen uit deze publicatie ondersteunen deze conclusie. Deze verwaarlozing leidt nu tot een te klein puntdraagvermogen, en een te groot schachtdraagvermogen. Naast het probleem van de verwaarlozing van de restkracht speelt er nog een belangrijk probleem: de gehanteerde invloedszone bij de methode Koppejan is gebaseerd op een destijds aangenomen bezwijkmechanisme, die volgens numerieke berekeningen uit deze publicatie onjuist is. Dit leidt tot nog meer onnauwkeurigheden. [less ▲]

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See detailLa référence à l’Alsace-Lorraine dans le rattachement et l’intégration d’Eupen-Malmedy à la Belgique (1918-1925)
Brüll, Christoph UL

Scientific Conference (2018, February 09)

En novembre 1910, le Journal des Tribunaux, principal organe d’information des juristes belges, qualifie la partie wallonne du Kreis allemand de Malmedy de « notre Alsace-Lorraine » où se trouveraient des ... [more ▼]

En novembre 1910, le Journal des Tribunaux, principal organe d’information des juristes belges, qualifie la partie wallonne du Kreis allemand de Malmedy de « notre Alsace-Lorraine » où se trouveraient des « frères de race et de langue, exilés et emprisonnés en Prusse. » Le 20 septembre 1920, ce Kreis ainsi que celui d’Eupen, presque exclusivement germanophone, sont rattachés à la Belgique, suite au traité de Versailles et à un simulacre de consultation populaire. Dans notre contribution qui traitera de la période qui s’étend de l’occupation de la région par des troupes belges en août 1919 à la fin du régime transitoire en mars 1925, nous voudrions nous interroger sur la signification de la référence à l’Alsace-Lorraine pendant cette phase du changement de la nationalité. Des indices donnent à penser que cette référence n’est pas limitée aux discours de légitimation de l’annexion du territoire par la Belgique, mais que les autorités belges ont, à certaines occasions (comme l’introduction du service militaire), contacté leurs homologues français afin de connaître la politique d’intégration menée en Alsace-Lorraine. En revanche, il n’y a jamais eu d’étude systématique de cette référence idéelle et pratique. Notre proposition voudrait combler cette lacune et constituerait également une contribution à une histoire comparée de la transition étatique dans les deux territoires. [less ▲]

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See detailSimulation-Based Fault Injection as a Verification Oracle for the Engineering of Time-Triggered Ethernet networks
Fejoz, Loïc; Regnier, Bruno; Miramont, Philippe et al

Scientific Conference (2018, February 02)

TTEthernet (TTE) is considered for use as high-speed backbone in the avionics of next-generation orbital space launchers. Given the key role of communication in launchers, the OEM must acquire a precise ... [more ▼]

TTEthernet (TTE) is considered for use as high-speed backbone in the avionics of next-generation orbital space launchers. Given the key role of communication in launchers, the OEM must acquire a precise understanding of TTE’s functioning and its performances in nominal and error conditions. This holds especially true for the clock synchronization algorithm, the cornerstone of time-triggered communication in TTE, which involves complex distributed algorithms. In this study, we use both an experimental platform and fault-injection on a simulation model to gain quantified insights in these questions. We first describe a fine-grained simulation model of TTE model and discuss how it has been validated against communication traces recorded on the TTE platform. We then present experiments that evaluate the accuracy of the clock synchronization in TTE in the fault-free case as well as considering permanent link failure and transient transmission errors. Finally, we discuss what we have learned during the project in terms of development process and programming language support for complex simulation models used in the design of critical systems. [less ▲]

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See detailInsights on the Performance and Configuration of AVB and TSN in Automotive Ethernet Networks
Migge, Jörn; Villanueva, Josetxo; Navet, Nicolas UL et al

Scientific Conference (2018, February 02)

Switched Ethernet is profoundly reshaping in-car communications. To meet the diverse real-time requirements in automotive communications, Quality-of-Service protocols that go beyond the mere use of ... [more ▼]

Switched Ethernet is profoundly reshaping in-car communications. To meet the diverse real-time requirements in automotive communications, Quality-of-Service protocols that go beyond the mere use of priorities are required. In this work, the basic questions that we investigate on a case-study with diverse and demanding communication requirements is what can we expect from the various protocols aimed at providing a better timing Quality of Service on top of Ethernet? And how to use them? Especially how to use them in a combined manner. We will focus on the Credit-Based Shaper of AVB, the Time-Aware Shaper of TSN and the use of priorities as defined in IEEE802.1Q. The performance metrics considered are the distributions of the communication latencies, obtained by simulation, as well as upper bounds on these quantities obtained by worst-case schedulability analysis. If there have been over the last 5 years numerous studies on the performance of AVB CBS, the literature on comparing AVB to TSN and other candidate protocols is still sparse. To the best of our knowledge, this empirical study is the first to consider most protocols currently considered in the automotive domain, with the aim to gain insights into the different technological, design and configurations alternatives. In particular, an objective of this study is to identify key problems that need to be solved in order to further automate network design and configuration. [less ▲]

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See detailThe Deformation Area Difference (DAD) method for condition assessment of reinforced structures
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Scherbaum, Frank et al

in Engineering Structures (2018), 155

The investigation and condition assessment of bridges have a very high priority in the construction industry today. Particularly, due to the fact that many bridge structures are getting old and partly ... [more ▼]

The investigation and condition assessment of bridges have a very high priority in the construction industry today. Particularly, due to the fact that many bridge structures are getting old and partly reach the end of their useful life, the control and condition assessment of bridge structures have become very important and essential. The present research work introduces an efficient new method for condition assessment called the Deformation Area Difference (DAD) Method. This new method represents an attractive alternative to visual inspection and long-term monitoring. In this paper, the new method with its theoretical background is presented and explained by means of a laboratory experiment and some additional theoretical calculation examples. The experimental investigations have been realised on a reinforced concrete beam, which has been gradually loaded until failure. For each load step, the stiffness reduction and the apparent cracking have been monitored. High-precision measurements such as close-range photogrammetry, digital levelling and displacement sensors have been used for the determination of the deflection curve. The DAD method has been applied to identify the area of the crack pattern of the laboratory experiment. Furthermore, the method is discussed with regard to the load level and the precision of the deformation measurements. On the basis of the laboratory experiment, the applicability of the DAD method for damage detection could be proven. Furthermore, the sensitivity of the method with regard to the damage degree, the static system, the damage position and the impact of temperature variation were analysed. [less ▲]

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See detailBeware: Nobody Wants to Be Lonely
Tkalec, Igor UL

Article for general public (2018)

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See detailTransnational experiences, language competences and worldviews: contrasting language policies in two recently migrated Greek families in Luxembourg
Kirsch, Claudine UL; Gogonas, Nikos

in Multilingua (2018)

Against the backdrop of the ongoing crisis-led migration from Southern to Northwestern Europe, the present paper reports on a case study of two families who have recently migrated from Greece to ... [more ▼]

Against the backdrop of the ongoing crisis-led migration from Southern to Northwestern Europe, the present paper reports on a case study of two families who have recently migrated from Greece to Luxembourg. Luxembourg has a trilingual education system and many pupils of migrant background face difficulties on this account. Drawing on the framework of Family Language Policy, this paper explores the language ideologies and management strategies of two families as well as factors influencing their policies. This qualitative study was based on interviews, observations, and videos recorded by one of the families. The findings show that the families have contrasting language ideologies and management strategies that are informed by their differing transnational experiences, competences and worldviews. This study can contribute to a better understanding of the ways in which migrant families use their language resources in their new country. [less ▲]

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See detailAttacks and Countermeasures for White-box Designs
Biryukov, Alex UL; Udovenko, Aleksei UL

E-print/Working paper (2018)

In the traditional symmetric cryptography, the adversary has access only to the inputs and outputs of a cryptographic primitive. In the white-box model the adversary is given full access to the ... [more ▼]

In the traditional symmetric cryptography, the adversary has access only to the inputs and outputs of a cryptographic primitive. In the white-box model the adversary is given full access to the implementation. He can use both static and dynamic analysis as well as fault analysis in order to break the cryptosystem, e.g. to extract embedded secret key. Implementations secure in such model have many applications in industry. However, creating such implementations turns out to be a very challenging if not an impossible task. Recently, Bos et al. proposed a generic attack on white-box primitives called differential computation analysis (DCA). This attack applies to most existent white-box implementations both from academia and industry. The attack comes from side-channel cryptanalysis method. The most common method protecting against such side-channel attacks is masking. Therefore, masking can be used in white-box implementations to protect against the DCA attack. In this paper we investigate this possibility and present multiple generic attacks against masked white-box implementations. We use the term “masking” in a very broad sense. As a result, we deduce new constraints that any secure white-box implementation must satisfy. We suggest partial countermeasures against the attacks. Some of our attacks were successfully applied to the WhibOx 2017 challenges. [less ▲]

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See detailSurmonter les barrières linguistiques avec « MaGrid » - un outil de formation de pré-mathématiques pour un contexte scolaire multilingue
Cornu, Véronique UL; Pazouki, Tahereh UL; Schiltz, Christine UL et al

Scientific Conference (2018, January 11)

Le contexte scolaire luxembourgeois est caractérisé par le multilinguisme et une population scolaire hétérogène, ce qui nécessite la mise en place de pratiques pédagogiques qui prennent en compte ... [more ▼]

Le contexte scolaire luxembourgeois est caractérisé par le multilinguisme et une population scolaire hétérogène, ce qui nécessite la mise en place de pratiques pédagogiques qui prennent en compte l’hétérogénéité des élèves. Dans le domaine des mathématiques, qui semble être non-verbal à première vue, des résultats scientifiques montrent que les enfants dont la langue maternelle est différente de la langue d’instruction, atteignent sur des tests d’aptitudes pré-mathématiques des résultats significativement inférieurs à ceux de leurs camarades natifs. Ceci est d’autant plus inquiétant, sachant que ces aptitudes pré-mathématiques sont prédictives des apprentissages ultérieurs. Par conséquent, nous avons développé l’outil de formation de pré-mathématiques non-verbale « MaGrid ». « MaGrid » permet à chaque enfant de bénéficier pleinement d’une instruction préscolaire en mathématiques, indépendamment de ses compétences langagières. Cet outil se caractérise par sa nature visuelle et il est implémenté sur tablette tactile. Jusqu’à présent, nous avons implémenté et évalué « MaGrid » lors de deux études scientifiques. Les résultats quantitatifs des évaluations empiriques sont prometteurs, comme ils montrent des effets positifs sur les habilités entraînées chez les enfants ayant utilisé cet outil comparé à un groupe contrôle. Dans une première étude, l’outil a été utilisé auprès de cinq classes durant 10 semaines, comprenant deux séances de 20 minutes par semaine. Les résultats lors de petites épreuves spécifiques ont été comparés aux résultats d’élèves de cinq classes n’ayant pas d’entraînement spécifique, et des effets d’intervention ont été observés. Dans une deuxième étude, nous nous sommes focalisés sur un groupe d’enfants de langue minoritaire (le portugais). « MaGrid » a été utilisé lors d’un programme d’intervention de pré-mathématiques s’étendant sur les deux années scolaires de l’école préscolaire. Les analyses préliminaires ont abouti à des résultats positifs. Des effets bénéfiques se sont manifestés sur différentes mesures de pré-mathématiques chez les enfants ayant suivi notre programme par rapport aux enfants du groupe contrôle. [less ▲]

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