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See detailNous l'avions attendu pendant des mois
Cicotti, Claudio UL

in Malvetti, Massimo (Ed.) Dante et Henri VII de Luxembourg: de l'utopie au prophetisme (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 detailEarly Language Education in Luxembourg
Kirsch, Claudine UL; Seele, Claudia

in Schwartz, Mila (Ed.) International Handbook of early childhood education (in press)

This chapter examines recent language education laws in Luxembourg as well as the ways in which early years practitioners appropriated the new policies and put them into practice. The chapter begins with ... [more ▼]

This chapter examines recent language education laws in Luxembourg as well as the ways in which early years practitioners appropriated the new policies and put them into practice. The chapter begins with a brief introduction of the linguistic landscape in Luxembourg and a summary of the dynamic development of the country’s early childhood education system. Special emphasis is put on recent changes in language education policies, which call for a more inclusive and multilingual early language education. Monolingual practices now need to open up to flexible language use and offer children opportunities to capitalize on their entire semiotic repertoire for communicating, meaning-making, and learning. The central concerns of this chapter are the ways in which policy changes influence educational practices in formal and non-formal settings and how professional development shapes this process. In order to address these questions, the authors review literature on language education policy, translanguaging and professional development and examine studies on early language education in Luxembourg. Next, they discuss recent initiatives of professional development in formal and non-formal early years settings as well as their outcomes. Finally, they present critical issues such as the practitioners’ reflexivity and responsibility and the sustainability of professional development. Future research directions include family language policies, partnerships between families and early childhood institutions and children’s languaging practices inside and across these institutions. [less ▲]

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See detailFlucht – Grenze – Integration / Fuga – Confine – Integrazione. Beiträge zum Phänomen der Deplatzierung / Contributi al fenomeno dello spostamento
Heimböckel, Dieter UL; Roelens, Nathalie UL; Wille, Christian UL

Book published by transcript (in press)

Wo und wie ereignen sich Grenzen? Inwiefern werden Migrant*innen zu Teilnehmer*innen von Regulierungspraktiken instrumentalisiert und in welcher Form werden damit auch Fragen der Integration berührt ... [more ▼]

Wo und wie ereignen sich Grenzen? Inwiefern werden Migrant*innen zu Teilnehmer*innen von Regulierungspraktiken instrumentalisiert und in welcher Form werden damit auch Fragen der Integration berührt? Unter diesen Aspekten setzen sich die Beiträger*innen dieses italienisch- und deutschsprachigen Bandes mit dem Verhältnis von Flucht, Grenze und Integration in literatur- und kulturwissenschaftlicher sowie räumlich-geographischer Perspektive auseinander. Ziel ist es, die Momente von Flucht, Grenze und Integration in ein produktives Spannungsverhältnis zu bringen und als eine von Phänomenen der Deplatzierung zusammengehaltene Trias zu diskutieren. [less ▲]

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See detailGeographien der Grenzen. Räume – Ordnungen – Verflechtungen
Weber, Florian; Wille, Christian UL; Caesar, Beate et al

Book published by Springer VS - VS Verlag (in press)

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

in Applied Linguistic Review (in press)

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

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

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See detailRäumliche Identifikationen und Identifizierungen in Grenzregionen. Das Beispiel der Großregion SaarLorLux
Wille, Christian UL

in Weber, Florian; Wille, Christian; Caesar, Beate (Eds.) et al Geographien der Grenze. Räume – Ordnungen – Verflechtungen (in press)

In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion ... [more ▼]

In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion SaarLorLux gefragt, wie die Einwohner den Raum repräsentieren und wie sie ihre alltagskulturellen Praktiken räumlich organisieren. Außerdem werden räumliche Projektionen im politischen Diskurs aufgedeckt und rekonstruiert, inwiefern diese in Identifizierungsprozessen wirksam sind. Die Betrachtungen stützen sich auf eine Repräsentativbefragung der Einwohner Luxemburgs und der an das Großherzogtum angrenzenden Gebiete in Frankreich, Belgien und Deutschland. Der Beitrag zeigt, dass nationale Grenzen in den Identifikations- und Identifizierungsvorgängen der Einwohner der Großregion SaarLorLux trotz grenzüberschreitender Verflechtungen und Alltagsgeographien eine wichtige Rolle spielen, aber nicht zwangsläufig als stabile Ordnungskategorien. [less ▲]

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See detailRestricted hypercontractivity on the Poisson space
Nourdin, Ivan UL; Peccati, Giovanni UL; Yang, Xiaochuan UL

in Proceedings of the American Mathematical Society (in press)

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See detailOversampled DFT-Modulated Biorthogonal Filter Banks: Perfect Reconstruction Designs and Multiplierless Approximations
Alves Martins, Wallace UL; Shankar, Bhavani UL; Ottersten, Björn UL

in IEEE Transactions on Circuits and Systems. II, Express Briefs (in press)

We propose a novel methodology for designing oversampled discrete Fourier transform-modulated uniform filter banks. The analysis prototype is designed as a Nyquist filter, whereas the synthesis prototype ... [more ▼]

We propose a novel methodology for designing oversampled discrete Fourier transform-modulated uniform filter banks. The analysis prototype is designed as a Nyquist filter, whereas the synthesis prototype is designed to guarantee perfect reconstruction (PR) considering oversampling. The resulting optimization problem fits into the disciplined convex programming framework, as long as some convex objective function is employed, as the minimization of either the stop-band energy or the maximum deviation from a desired response. The methodology also accounts for near-PR multiplierless approximations of the prototype analysis and synthesis filters, whose coefficients are obtained in the sum-of-power-of-two (SOPOT) space. The quantized coefficients are computed using successive approximation of vectors, which is able to yield filters with a reduced number of SOPOT coefficients in a computationally efficient manner. The proposed methodology is especially appealing for supporting actual hardware deployments, such as modern digital transparent processors to be used in next-generation satellite payloads. [less ▲]

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See detailThe Origins and Contemporary Development of Work-based Higher Education in Germany: Lessons for Anglophone Countries?
Graf, Lukas; Powell, Justin J W UL

in Wheelehan, Leesa; Bathmaker, Ann-Marie; Orr, Kevin (Eds.) et al Higher-level Vocational Education: The Route to High Skills and Productivity as well as Greater Equity? An International Comparative Analysis (in press)

Today, higher education is typically seen as offering the most assured pathways to secure careers and low unemployment rates. Yet, increasingly some groups, not least higher education graduates and their ... [more ▼]

Today, higher education is typically seen as offering the most assured pathways to secure careers and low unemployment rates. Yet, increasingly some groups, not least higher education graduates and their families paying ever-higher tuition fees, question the taken-for-granted contributions higher education makes to individuals and society as a whole. Despite decades of mass higher education expansion, even societies with strong systems continue to struggle to achieve their goal of universalizing participation and equalizing access. While in part this is due to limited public or corporate funding for (affordable) study opportunities, differentiated systems, such as in the US, also lack policy coordination and effective governance, providing a surfeit of options. While participation rates have climbed worldwide, higher education systems continue to produce winners (“insiders”) and losers (“outsiders”), even as the “schooled society” shifts the occupational structure upward. Market-oriented higher education systems face increasing privatization, which also involves financializing university governance. Many states have retrenched investments that had once underwritten universities’ flourishing and their moves toward massification. Tensions have deepened over who should pay for rising costs, exacerbated in an era of increasing status competition via higher education. In the face of such challenges globally, which alternatives exist? A prominent possibility, pioneered in Germany in the 1970s, are “dual study” programs offered by several organizational forms, from vocational academies to universities of applied sciences. Such hybrid programs fully integrate phases of higher education study and paid work in firms. Another potential advantage of apprenticeship training being offered in conjunction with higher education is that this would boost the reputation of apprenticeships overall. The German experience indicates that the attractiveness of the apprenticeship training system as a whole can be bolstered when it offers a viable pathway also for those individuals with a traditional university entrance certificate. If these students seriously consider and choose advanced work-based higher education, this may well increase the standing of apprenticeship training among students, their families, and employers. Thus, dual study programs provide an innovative model for policymaking and implementation. Especially when considering strategies to improve skill formation overall, to reduce the costs individuals must bear in attaining higher education, and to improve the fit between the expectations of employers and potential employees regarding skill formation, dual study programs excel. The origins and contemporary developments in work-based higher education in Germany offer lessons and inspiration for Anglophone countries, with their strong and differentiated higher education systems, to further bolster study programs coordinated with firms. [less ▲]

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See detailWelfare-Based Income Insecurity in the US and Germany: Evidence from Harmonized Panel Data
d'ambrosio, Conchita UL; Rohde, Nicholas; Tang, Kam Ki et al

in Journal of Economic Behavior and Organization (in press)

This paper develops normative approaches for measuring individual-level income insecurity. Using concepts derived from Expected Utility Theory and Prospect Theory, we build a suite of measures designed to ... [more ▼]

This paper develops normative approaches for measuring individual-level income insecurity. Using concepts derived from Expected Utility Theory and Prospect Theory, we build a suite of measures designed to capture various facets of psychologically distressing income risk. We present an application for the US and Germany from 1993-2013, employing conditionally heteroskedastic fixed-effects models to generate predictive densities for future incomes. Our results reveal much higher levels of income risk in the US relative to Germany, which can be mostly attributed to a higher level of autonomous, time-invariant volatility. State-by-state variations in liberal/conservative political administrations partially explain our results, and we find some evidence that trade exposure is a contributing factor in the US. [less ▲]

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See detailGrenzgeographien der COVID-19-Pandemie
Florian, Weber; Wille, Christian UL

in Weber, Florian; Wille, Christian; Caesar, Beate (Eds.) et al Geographien der Grenze. Räume – Ordnungen – Verflechtungen (in press)

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See detailPatterns of health related gender inequalities – a cluster analysis of 45 countries
Heinz, Andreas UL; Catunda, Carolina UL; van Duin, Claire UL et al

in Journal of Adolescent Health (in press), 66(6S), 27-37

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See detailLiving in the Shadow of the Past: Financial Profiles and Well-Being
d'ambrosio, Conchita UL; Clark, Andrew; Zhu, Rong

in Scandinavian Journal of Economics (in press)

We here consider the link between individual financial profiles over time and well-being, as measured by life satisfaction. We in particular look at annual self-reported financial worsening and ... [more ▼]

We here consider the link between individual financial profiles over time and well-being, as measured by life satisfaction. We in particular look at annual self-reported financial worsening and improvement information for over 25,000 individuals in Australian panel data from 2002 to 2017. We first find that satisfaction falls (rises) with a contemporaneous major financial worsening (improvement), with the the largest correlation being with financial worsening. Second, the experience of these financial events in the past continues to be linked to current well-being. Last, only the order of financial-improvement spells relates to well-being: a given number of past years where finances deteriorated has the same association with current well-being whether the deterioration occurred in one continuous spell or was interrupted. We last show that these associations are heterogeneous over the distribution of well-being. [less ▲]

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See detailBeam-inside-beam contact: Mechanical simulations of slender medical instruments inside the human body
Magliulo, Marco UL; Lengiewicz, Jakub UL; Zilian, Andreas UL et al

in Computer Methods and Programs in Biomedicine (in press)

Background and Objective. This contribution presents a rapid computational framework to mechanically simulate the insertion of a slender medical instrument in a tubular structure such as an artery, the ... [more ▼]

Background and Objective. This contribution presents a rapid computational framework to mechanically simulate the insertion of a slender medical instrument in a tubular structure such as an artery, the cochlea or another slender instrument. Methods. Beams are employed to rapidly simulate the mechanical behaviour of the medical instrument and the tubular structure. However, the framework’s novelty is its capability to handle the mechanical contact between an inner beam (representing the medical instrument) embedded in a hollow outer beam (representing the tubular structure). This "beam-insidebeam" contact framework, which forces two beams to remain embedded, is the first of its kind since existing contact frameworks for beams are "beam-to-beam" approaches, i.e. they repel beams from each other. Furthermore, we propose contact kinematics such that not only instruments and tubes with circular cross-sections can be considered, but also those with elliptical cross-sections. This provides flexibility for the optimization of patient-specific instruments. Results. The results demonstrate that the framework’s robustness is substantial, because only a few increments per simulation and a few iterations per increment are required, even though large deformations, large rotations and large curvature changes of both the instrument and tubular structure occur. The stability of the framework remains high even if the modulus of the inner tube is thousand times larger than that of the outer tube. A mesh convergence study furthermore exposes that a relatively small number of elements are required to accurately approach the reference solution. Conclusions. The framework’s high simulation speed originates from the exploitation of the rigidity of the beams’ cross-sections to quantify the exclusion between the inner and the hollow outer beam. This rigidity limits the accuracy of the framework at the same time, but this is unavoidable since simulation accuracy and simulation speed are two competing interests. Hence, the framework is particularly attractive if simulation speed is preferred over accuracy. [less ▲]

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See detailHybrid User Pairing for Spectral and Energy Efficiencies in Multiuser MISO-NOMA Networks with SWIPT
Nguyen, Toan-Van; Nguyen, van Dinh UL; Costa, Daniel Benevides Da et al

in IEEE Transactions on Communications (in press)

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power ... [more ▼]

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power transfer. In this system, two information users with distinct channel conditions are optimally paired while energy users perform energy harvesting (EH) under non-linearity of the EH circuits. We consider the problem of jointly optimizing user pairing and power allocation to maximize the overall spectral efficiency (SE) and energy efficiency (EE) subject to userspecific quality-of-service and harvested power requirements. A new paradigm for the EE-EH trade-off is then proposed to achieve a good balance of network power consumption. Such design problems are formulated as the maximization of nonconcave functions subject to the class of mixed-integer non-convex constraints, which are very challenging to solve optimally. To address these challenges, we first relax binary pairing variables to be continuous and transform the design problems into equivalent non-convex ones, but with more tractable forms. We then develop low-complexity iterative algorithms to improve the objectives and converge to a local optimum by means of the inner approximation framework. Simulation results show the convergence of proposed algorithms and the SE and EE improvements of the proposed HUP scheme over state-of-the-art designs. In addition, the effects of key parameters such as the number of antennas and dynamic power at the BS, target data rates, and energy threshold, on the system performance are evaluated to show the effectiveness of the proposed schemes in balancing resource utilization. [less ▲]

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

in Engineering Structures (in press)

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

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

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

in Engineering Structures (in press)

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

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

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