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See detailKontext und Praktiken der Circular Economy in Luxemburg
Hild, Paula UL

Doctoral thesis (2021)

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See detailDetection of fluid level in bores for batch size one assembly automation using convolutional neural network
Simeth, Alexej UL; Plaßmann, Jessica; Plapper, Peter UL

in Advances in Production Management Systems. Artificial Intelligence for Sustainable and Resilient Production Systems. (2021, August 31), 632

Increased customization and shortening product life cycles pose a challenge for automation, especially in assembly. In combination with the nature of assembly tasks, which may require high level of ... [more ▼]

Increased customization and shortening product life cycles pose a challenge for automation, especially in assembly. In combination with the nature of assembly tasks, which may require high level of perception, skill, and logical thinking, these tasks are often conducted manually, especially in certain industries (e.g. furniture, power tools) or small and medium-sized enterprises. One of such tasks is the liquid level monitoring in gluing processes. Existing non-manual solutions are based on conventional and less flexible algorithms to detect the current liquid level. In production environments with highly individualized products, a need for more performant models arises. With artificial intelligence (AI) it is possible to deduct decisions from unknown multidimensional correlations in sensor data, which is a key enabler for assembly automation for products with high degree of customization. In this paper, an AI-based model is proposed to automate a gluing process in a final assembly. Images of a gluing process are taken with a camera and a convolutional neural network is used to extract images features. The features are applied to train a support vector machine classifier to identify the liquid level. The developed model is tested and validated with a Monte-Carlo-simulation and used on a demonstrator to automate a gluing process. The developed model classifies images of liquid levels with over 98% accuracy. Similar results are achieved on the demonstrator. [less ▲]

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See detailEffects of the COVID-pandemic:The role of family culture and effects on well-being
Minelli, Anne; Murdock, Elke UL; Albert, Isabelle UL

Scientific Conference (2021, August 27)

During the COVID pandemic governments across the globe put restrictions in place to curb the spread of the virus. During the strict lock-down phase, people were only permitted to leave the house for ... [more ▼]

During the COVID pandemic governments across the globe put restrictions in place to curb the spread of the virus. During the strict lock-down phase, people were only permitted to leave the house for essential reasons, and visiting of family members living in a different household was not allowed. The aim of the present study was to investigate possible effects of these COVID restrictions on well-being according to different family models. Extending Kağitçibasi’s (2007, 2013) postulated family model by Manzi et al.’s (2006) aspects of family cultures (enmeshment, cohesion, autonomy and social support) we first explored, if these family models can be replicated in Luxembourg. We then tested, if lock-down restrictions affected family models differently in terms of well-being. A total of N = 244 (Mage = 35 years, SD = 12.2; 73% female) completed our online questionnaire at the time of the strict lockdown in April-Mai 2020 in Luxembourg. To capture the impact of the pandemic, the questionnaire was divided into two parts. First, participants answered questions about their well-being, family culture and closeness to their parents in general. Participants were then reminded of COVID lockdown restrictions and asked to answer under these restrictions. Using cluster analysis we identified three family models, namely psychologically interdependent families (focus on cohesion and social support), independent families (focus on autonomy), and interdependent families (focus: enmeshment, cohesion and social support). The independent family cluster showed lower well-being before and during the pandemic compared to psychologically interdependent families. Our findings suggest that different family models as postulated by Kağitçibasi are indeed affected differently by the pandemic. Furthermore, there appears to be a particular association between cohesion and well-being. Implications of these findings will be discussed also in the family model framework. [less ▲]

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See detailFunctional meta-omics provide critical insights into long- and short-read assemblies
Galata, Valentina UL; Busi, Susheel Bhanu UL; Kunath, Benoît UL et al

in Briefings in Bioinformatics (2021)

Real-world evaluations of metagenomic reconstructions are challenged by distinguishing reconstruction artifacts from genes and proteins present in situ. Here, we evaluate short-read-only, long-read-only ... [more ▼]

Real-world evaluations of metagenomic reconstructions are challenged by distinguishing reconstruction artifacts from genes and proteins present in situ. Here, we evaluate short-read-only, long-read-only and hybrid assembly approaches on four different metagenomic samples of varying complexity. We demonstrate how different assembly approaches affect gene and protein inference, which is particularly relevant for downstream functional analyses. For a human gut microbiome sample, we use complementary metatranscriptomic and metaproteomic data to assess the metagenomic data-based protein predictions. Our findings pave the way for critical assessments of metagenomic reconstructions. We propose a reference-independent solution, which exploits the synergistic effects of multi-omic data integration for the in situ study of microbiomes using long-read sequencing data. [less ▲]

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See detailBeyond the pandemic: Shaping of futures in (even more?) diverse educational settings - Critical discussion of contributions of invited symposium SIG 21
Max, Charles UL

Scientific Conference (2021, August 27)

Looking at SIG 21’s mission statement, the diversity of learning and education (which is / was ?) a granted element in educational research, seems to hail from a post/past century, where not everyone was ... [more ▼]

Looking at SIG 21’s mission statement, the diversity of learning and education (which is / was ?) a granted element in educational research, seems to hail from a post/past century, where not everyone was doing learningonline, remotely via the same tools and devices (i.e. zoom, etc.) Therefore, we wonder ifthe diversity still can be looked at in similar ways, and if so, which other ways of looking at the « new normal » should be developed, both from a practical, empirical research point of view, but also from a theoretical and epistemic perspective, underlying new research (or research into the new normal).Following this first line of thought, which questions could determine future research into education, educational settings and learning as such? This seems of particular interest, as the current ways of looking into education are heavily biased by concerns of technological infrastructure, investment and structural fitness (i.e., teachers as appexperts, networks, online setups, disregarding actual learners). Moreover, other ways of looking into formerly accepted « groups » (i.e., gender, age, background) seem to fall apart and disintegrate, making the issue of heterogeneity even more challenging to grapple with. Finally, when looking at the landscape of educational contexts and their societal anchorage at large (i.e., learning settings, formal/informal settings, mobility, development of professionals …) one aspect seems of particular interest: Is there learning in and from the actual situation ? How sustainable are the developments? Which perspectives can be drawn beyond the short term? [less ▲]

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See detailLong-term effects of retention in grade 8 in Luxembourg
Klapproth, Florian; Keller, Ulrich UL; Fischbach, Antoine UL

Scientific Conference (2021, August 26)

Meta-analyses have suggested that grade retention rarely has positive effects and more often negative effects on students’ performance and psycho-emotional well-being. The occurrence of negative effects ... [more ▼]

Meta-analyses have suggested that grade retention rarely has positive effects and more often negative effects on students’ performance and psycho-emotional well-being. The occurrence of negative effects may be due to the absence of new learning experiences. However, in the short term, positive effects of grade retention are quite likely to occur. In Luxembourg, more than half of the students repeat at least one grade within their entire school career. Since grade retention is applied quite frequently, the aim of the current study was to examine long-term effects of grade retention. A representative sample of 2,835 Luxembourgish 8th grade students was used for this study, and propensity score matching was applied to select a control group of promoted students who were similar to the retained students on a variety of characteristics. Furthermore, a type of comparison was used by which the outcome variables of the retained and promoted students were compared at different times while the grade- and age-cohort were held equal between groups. With respect to school marks as an indicator of students’ academic achievement, this study showed that grade 8 retention lowered repeaters’ school marks, on average, in grades 10 to 13, as compared to matched non-repeaters. [less ▲]

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See detailNew Estimates of Inequality of Opportunity Across European Cohorts (and Some Insights on the Long-term Impact of Educational Policy)
Andreoli, Francesco; Fusco, Alessio; Kyzyma, Iryna et al

Scientific Conference (2021, August 25)

This paper provides a set of new estimates of inequality of opportunity (IOp) in Europe, using the European Union Statistics on Income and Living Condition (EU-SILC). Unlike previous research, we estimate ... [more ▼]

This paper provides a set of new estimates of inequality of opportunity (IOp) in Europe, using the European Union Statistics on Income and Living Condition (EU-SILC). Unlike previous research, we estimate inequality of opportunity within birth cohorts, which we argue is the most appropriate population level for inequality of opportunity analysis. Most IOp measures require estimation of the conditional distribution of the outcome of interest given circumstances. With multiple circumstances and the sample sizes available in EU-SILC, we use distribution regression methods combined with local kernel weighting and show how these can be used to estimate a large set of IOp measures. Endowed with cohort-level estimates of IOp, we finally examine the relationship between educational policy variables measured at the time of parental education and offspring generation inequality of opportunity in adulthood. We find a negative relationship between the duration of compulsory education of the parents and IOp among offspring, but the relationship is not very strong. [less ▲]

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See detailNormative coherence for development – What relevance for responsive regionalism?
Koff, Harlan UL; Häbel, Sandra UL

in Development Policy Review (2021)

Without a normative dimension, transformative development risks reproducing traditional economic development. In this special issue we focus on norm implementation in different world regions through the ... [more ▼]

Without a normative dimension, transformative development risks reproducing traditional economic development. In this special issue we focus on norm implementation in different world regions through the lens of normative coherence for development. This special issue indicates that regions are an important interlocutor between the global, national, and sub-national level and, as such, are crucial for implementing the sustainable development agenda. The articles show, however, that to date normative coherence for development has not been achieved due to overriding priorities and technical approaches to policy coherence for development. With this special issue we aim to draw more attention to the topic of normative coherence for development and show that policies need to be adjusted in order to reflect the normative dimension of sustainable development. [less ▲]

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See detailRole of higher-order effects in spin-misalignment small-angle neutron scattering of high-pressure torsion nickel
Oba, Yojiro; Bersweiler, Mathias UL; Titov, Ivan et al

in Physical Review Materials (2021), 5

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See detailSoftware for the frontiers of quantum chemistry: An overview of developments in the Q-Chem 5 package
Evgeny Epifanovsky; Andrew T. B Gilbert; Xintian Feng et al

in Journal of Chemical Physics (2021)

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See detailDistribution of kinks in an Ising ferromagnet after annealing and the generalized Kibble-Zurek mechanism
Mayo, Jack J.; Fan, Zhijie; Chern, Gia-Wei et al

in Physical Review Research (2021)

We consider the annealing dynamics of a one-dimensional Ising ferromagnet induced by a temperature quench in finite time. In the limit of slow cooling, the asymptotic two-point correlator is analytically ... [more ▼]

We consider the annealing dynamics of a one-dimensional Ising ferromagnet induced by a temperature quench in finite time. In the limit of slow cooling, the asymptotic two-point correlator is analytically found under Glauber dynamics, and the distribution of the number of kinks in the final state is shown to be consistent with a Poissonian distribution. The mean kink number, the variance, and the third centered moment take the same value and obey a universal power-law scaling with the quench time in which the temperature is varied. The universal power-law scaling of cumulants is corroborated by numerical simulations based on Glauber dynamics for moderate cooling times away from the asymptotic limit, when the kink-number distribution takes a binomial form. We analyze the relation of these results to physics beyond the Kibble-Zurek mechanism for critical dynamics, using the kink-number distribution to assess adiabaticity and its breakdown.We consider linear, nonlinear, and exponential cooling schedules, among which the last provides the most efficient shortcuts to cooling in a given quench time. The nonthermal behavior of the final state is established by considering the trace norm distance to a canonical Gibbs state. [less ▲]

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See detail„Raum für Mehrsprachigkeit geben!“
Heinzel, Friederike; Schüler, Liz; Kirsch, Claudine UL et al

in Die Grundschulzeitschrift (2021)

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See detailAlmost global convergence to practical synchronization in the generalized Kuramoto model on networks over the n-sphere
Markdahl, Johan UL; Proverbio, Daniele UL; Mi, La et al

in Communications Physics (2021), 4

From the flashing of fireflies to autonomous robot swarms, synchronization phenomena are ubiquitous in nature and technology. They are commonly described by the Kuramoto model that, in this paper, we ... [more ▼]

From the flashing of fireflies to autonomous robot swarms, synchronization phenomena are ubiquitous in nature and technology. They are commonly described by the Kuramoto model that, in this paper, we generalise to networks over n-dimensional spheres. We show that, for almost all initial conditions, the sphere model converges to a set with small diameter if the model parameters satisfy a given bound. Moreover, for even n, a special case of the generalized model can achieve phase synchronization with nonidentical frequency parameters. These results contrast with the standard n = 1 Kuramoto model, which is multistable (i.e., has multiple equilibria), and converges to phase synchronization only if the frequency parameters are identical. Hence, this paper shows that the generalized network Kuramoto models for n ≥ 2 displays more coherent and predictable behavior than the standard n = 1 model, a desirable property both in flocks of animals and for robot control. [less ▲]

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See detailAutour des possessions luxembourgeoises dans le comté de Hainaut sous le règne de Jean, roi de Bohême et comte de Luxembourg (1310-1346)
Pettiau, Hérold UL

Scientific Conference (2021, August 20)

The purpose of this contribution is to open what appeared at first sight to be a small dossier, devoted to the heritage held in the county of Hainaut for several decades at the beginning of the 14th ... [more ▼]

The purpose of this contribution is to open what appeared at first sight to be a small dossier, devoted to the heritage held in the county of Hainaut for several decades at the beginning of the 14th century between 1304 and 1343, and even afterwards, by the counts of the Luxembourg dynasty (Henry VII and his son John the Blind, King of Bohemia), of which I have presented the main items and the interest that their study (and publication) could bring. This file is interesting in more than one way: It is- on the Luxembourg side at least, little known - even if important documents have been published and available for a long time - these 'outlying' possessions have not been much taken into consideration by researchers working on the territorialisation of the principality or on the 'finances' of John of Bohemia. It also concerns a period during which documentary writing developed in the management of the possessions of the principalities of the Low Countries - including, of course, Hainaut (in union with Zealand Holland), which has been very well studied by Valeria Van Camp. In Luxembourg, a first cartulary, currently called liber foeodorum, was drawn up in 1308-1309, and subsequently completed; a second in 1343, and also a censary (or Urbar) noting the revenues of the various components of the possessions of the Luxembourgs by provostship, land, and castellany in the years 1306-1317, subsequently completed in the years 1322-1327. This file raises questions about the practical management of such possessions, which were quite remote, beyond the administrative organisation of the county. [less ▲]

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See detailOptimal Motion Planning and Control with Safety Guarantees for Aerial Robots
Castillo López, Manuel UL

Doctoral thesis (2021)

Autonomous aerial robots are expected to revolutionize many industries, such as construction, transportation or even space exploration. However, to target an industry where different robots and humans are ... [more ▼]

Autonomous aerial robots are expected to revolutionize many industries, such as construction, transportation or even space exploration. However, to target an industry where different robots and humans are meant to share the same space our algorithms need to provide safety and efficiency guarantees. Navigating autonomously in these kind of environments poses a great challenge. We may face a significant number of obstacles, and we can only estimate where they are and where they are expected to be, but not exactly. Dealing with these uncertainties is a challenging problem in most robotics applications, including motion planning and control. During the last decade, major contributions have established the theoretical basis upon which optimal motion planning and control with safety guarantees can be achieved. However, they involve a high computational cost that scales exponentially with the number of obstacles, rendering a limited domain of robotic applications. The main contribution of this thesis provides an efficient, scalable and safe approximation to this problem, allowing its application to embedded systems with fast dynamics such as aerial robots. This thesis also includes an additional contribution that allow these methods to plan longer trajectories with a minimal computational footprint, allowing to better anticipate evasive maneuvers. These contributions have been validated mathematically, in simulation and in real-time operation on aerial robots, handling uncertain dynamic obstacles such as pedestrians. [less ▲]

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See detailErgebnisse des Jugendberichtes 2020
Schumacher, Anette UL; S

in Ergebnisse des Jugendberichtes 2020 (2021)

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See detailNational and transnational family and friendship networks and their role for subjective well-being of older migrants compared to non-migrants in Luxembourg
Albert, Isabelle UL; Hoffmann, Martine; Vandenbosch, Petra et al

Scientific Conference (2021, August 18)

Creating new bonds in the receiving country constitutes an important developmental task for migrants. Nonetheless, migrants often have smaller social networks in the receiving countries compared to non ... [more ▼]

Creating new bonds in the receiving country constitutes an important developmental task for migrants. Nonetheless, migrants often have smaller social networks in the receiving countries compared to non-migrants, while they stay connected with left behind family members in their countries of origin. The role of transnational ties can thereby be twofold – on the one hand, transnational relations might provide support for migrants from a distance, on the other hand feelings of loneliness might arise when network partners are living far away. The present study is part of the project PAN-VAL on active ageing in Luxembourg, financed by the Ministry of Family and Integration, which focusses on social embeddedness vs. social isolation of migrants and non-migrants living in the multicultural context of Luxembourg. A national sample of N=1000 migrants and non-migrants 50+ living in Luxembourg were asked about their family and friendship networks, their satisfaction with family, friends and life as a whole as well as their feelings of loneliness. Further, N = 20 qualitative interviews with older migrants and non-migrants in four selected municipalities were carried out to explore social networks in more depth. First analyses revealed smaller national family and friendship networks of migrants compared to non-migrants and people with double nationality, whereas migrants reported more transnational bonds. Migrants also reported a lower satisfaction with family and friendship networks compared to non-migrants and people with double nationality, whereas no differences were found between migrants and non-migrants with regard to feelings of loneliness. However, people with double nationality felt less lonely compared to both other groups. Results will be discussed in a life-span perspective, considering the role of national family and friendship networks to create a sense belonging as a fundamental need of human beings. [less ▲]

Detailed reference viewed: 104 (5 UL)