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See detailExtreme values, means, and inequality measurement
d'ambrosio, Conchita UL; Bossert, Walter; Kamaga, Kohei

in Review of Income and Wealth (in press)

We examine some ordinal measures of inequality that are familiar from the literature. These measures have a quite simple structure in that their values are determined by combinations of specific summary ... [more ▼]

We examine some ordinal measures of inequality that are familiar from the literature. These measures have a quite simple structure in that their values are determined by combinations of specific summary statistics such as the extreme values and the arithmetic mean of a distribution. In spite of their common appearance, there seem to be no axiomatizations available so far, and this paper is intended to fill that gap. In particular, we consider the absolute and relative variants of the range; the max-mean and the mean-min orderings; and quantile-based measures. In addition, we provide some empirical observations that are intended to illustrate that, although these orderings are straightforward to define, some of them display a surprisingly high correlation with alternative (more complex) measures. [less ▲]

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See detailPredictive and interpretable models via the stacked elastic net
Rauschenberger, Armin UL; Glaab, Enrico UL; van de Wiel, Mark

in Bioinformatics (in press)

Motivation: Machine learning in the biomedical sciences should ideally provide predictive and interpretable models. When predicting outcomes from clinical or molecular features, applied researchers often ... [more ▼]

Motivation: Machine learning in the biomedical sciences should ideally provide predictive and interpretable models. When predicting outcomes from clinical or molecular features, applied researchers often want to know which features have effects, whether these effects are positive or negative, and how strong these effects are. Regression analysis includes this information in the coefficients but typically renders less predictive models than more advanced machine learning techniques. Results: Here we propose an interpretable meta-learning approach for high-dimensional regression. The elastic net provides a compromise between estimating weak effects for many features and strong effects for some features. It has a mixing parameter to weight between ridge and lasso regularisation. Instead of selecting one weighting by tuning, we combine multiple weightings by stacking. We do this in a way that increases predictivity without sacrificing interpretability. Availability and Implementation: The R package starnet is available on GitHub: https://github.com/rauschenberger/starnet. [less ▲]

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See detailVirtual Agent Representation for Critical Transactions
Sun, Ningyuan UL; Botev, Jean UL

in Proceedings of the 12th ACM Multimedia Systems Conference (MMSys) (in press)

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See detailTaxation in matching markets
Dupuy, Arnaud UL; Galichon, Alfred; Jaffe, Sonia et al

in International Economic Review (in press)

We analyze the effects of taxation in two-sided matching markets where agents have heterogeneous preferences over potential partners. Our model provides a continuous link between models of matching with ... [more ▼]

We analyze the effects of taxation in two-sided matching markets where agents have heterogeneous preferences over potential partners. Our model provides a continuous link between models of matching with and without transfers. Taxes generate inefficiency on the allocative margin, by changing who matches with whom. This allocative inefficiency can be non-monotonic, but is weakly increasing in the tax rate under linear taxation if each worker has negative non-pecuniary utility of working. We adapt existing econometric methods for markets without taxes to our setting, and estimate preferences in the college-coach football market. We show through simulations that standard methods inaccurately measure deadweight loss. [less ▲]

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See detailIntegrated STEAM Approach in Outdoor Trails with Elementary School Pre-service Teachers in Luxemburg
Haas, Ben; Kreis, Yves UL; Lavicza, Zsolt

in Journal of Educational Technology and Society (in press), 24(4),

Due to the COVID-19 pandemic it was impossible to carry out on-campus teaching and examinations as planned for the first-year elementary school Bachelor’s degree teacher training courses during the summer ... [more ▼]

Due to the COVID-19 pandemic it was impossible to carry out on-campus teaching and examinations as planned for the first-year elementary school Bachelor’s degree teacher training courses during the summer term of 2019/2020. Therefore, we moved our on-campus STEAM (Science, Technology, Engineering, Arts and Mathematics) related courses to schooling at home. For their course examination, students designed outdoor trails in groups with the educational technology MathCityMap based on an integrated STEAM approach. Hence, they combined STEAM with real-world situations (e.g., monuments, marketplaces, playgrounds). The tasks within the trails required the use of technologies such as augmented reality (AR), digital modelling (e.g., GeoGebra 3D Graphing Calculator), and GPS. Analogue measuring tools (e.g., triangle ruler) were also used in the task designs. We collected data from 21 trails with 259 tasks from 49 pre-service teachers to analyse the effects on professional growth in STEAM education. Through hierarchical cluster analysis we identified three different clusters with patterns regarding STEAM in outdoor trails. This paper will describe a pedagogical framework for the integrated STEAM approach to designing and evaluating outdoor trails. Furthermore, we will explain patterns pre-service teachers developed during this professional development. [less ▲]

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See detailArticle 47 of the Charter in the Opinion procedure
Neframi, Eleftheria UL

in European Papers (in press)

This paper affirms that external relations are outside the scope of Article 47 of the Charter. This does not however mean that the principle of judicial protection and the right of access to an ... [more ▼]

This paper affirms that external relations are outside the scope of Article 47 of the Charter. This does not however mean that the principle of judicial protection and the right of access to an independent tribunal have only an internal EU law dimension. In Opinion 1/17, The Court of Justice could assess the CETA’s compatibility with the right of access to an independent tribunal without having recourse to Article 47 of the Charter, on the ground either of the principle of autonomy or of the compatibility with the substantive provisions of the common commercial policy. This paper argues that while judicial protection as part of the autonomy claim could meet some conceptual limits, promoting judicial protection as part of the common commercial policy could reinforce the perception that the Union is a credible and influential actor in international trade and in international procedural law. [less ▲]

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See detailLes transformations d'un recueil hagiographique monumental: le grand légendier de Saint-Maximin de Trèves aux XVe-XVIe siècles
Dubuisson, Bastien UL

in Peloux, Fernand (Ed.) Des saints et des livres: Christianisme flamboyant et manuscrits hagiographiques du Nord à la fin du Moyen Âge (XIIIe-XVIe siècles) (in press)

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See detailChancen für Luxemburgs (Finanz-)Wirtschaft in und nach der Krise
Dörry, Sabine; Schulz, Christian UL

in Mein, Georg; Pause, Johannes (Eds.) Self and Society in the Corona Crisis (in press)

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See detailThe "failure" of cooperatives in Kyrgyzstan? A postcapitalist critique of a biased narrative
Cima, Ottavia UL

in Geographica Augustana (in press)

Detailed reference viewed: 72 (5 UL)
See detailThe Ends of the Humanities
Baumann, Isabell Eva UL; Dembeck, Till UL; Mein, Georg UL

Book published by Melusina Press (in press)

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See detailFast cross-validation for multi-penalty ridge regression
van de Wiel, Mark A.; van Nee, Mirrelijn M.; Rauschenberger, Armin UL

in Journal of Computational and Graphical Statistics (in press)

Prediction based on multiple high-dimensional data types needs to account for the potentially strong differences in predictive signal. Ridge regression is a simple, yet versatile and interpretable model ... [more ▼]

Prediction based on multiple high-dimensional data types needs to account for the potentially strong differences in predictive signal. Ridge regression is a simple, yet versatile and interpretable model for high-dimensional data that has challenged the predictive performance of many more complex models and learners, in particular in dense settings. Moreover, it allows using a specific penalty per data type to account for differences between those. Then, the largest challenge for multi-penalty ridge is to optimize these penalties efficiently in a cross-validation (CV) setting, in particular for GLM and Cox ridge regression, which require an additional loop for fitting the model by iterative weighted least squares (IWLS). Our main contribution is a computationally very efficient formula for the multi-penalty, sample-weighted hat-matrix, as used in the IWLS algorithm. As a result, nearly all computations are in the low-dimensional sample space. We show that our approach is several orders of magnitude faster than more naive ones. We developed a very flexible framework that includes prediction of several types of response, allows for unpenalized covariates, can optimize several performance criteria and implements repeated CV. Moreover, extensions to pair data types and to allow a preferential order of data types are included and illustrated on several cancer genomics survival prediction problems. The corresponding R-package, multiridge, serves as a versatile standalone tool, but also as a fast benchmark for other more complex models and multi-view learners. [less ▲]

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See detailEngagement féministe en sons et en images dans l’œuvre cinématographique d’Assia Djebar
Barthelmebs-Raguin, Hélène UL

in Guaaybess, Tourya; Di Cesare, Nurit; Levy, Jessica (Eds.) et al Femmes engagées au cœur de l’action. Mise en récit(s), mise en image(s) (in press)

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See detailBorderscapes
Wille, Christian UL

in Fellner, Astrid; Nossem, Eva (Eds.) Glossary Border Studies (in press)

Der Beitrag arbeitet das in der Grenzforschung am weitesten verbreitete Verständnis von ‚borderscapes‘ heraus und gibt den Ansatz in seinen Grundzügen wieder. Dafür werden zu-nächst die Verwendungen des ... [more ▼]

Der Beitrag arbeitet das in der Grenzforschung am weitesten verbreitete Verständnis von ‚borderscapes‘ heraus und gibt den Ansatz in seinen Grundzügen wieder. Dafür werden zu-nächst die Verwendungen des Begriffs und die damit implizierten Verständnisse dargelegt. Darauf aufbauend wird ‚borderscapes’ als relationale, diffundierte, episodische, perspektivi-sche und umkämpfte Formationen systematisiert, die mit nationalen Grenzen in Beziehung stehen. Darüber wird gezeigt, inwiefern ‚borderscapes‘ mit der ‚traditionellen‘ Idee von Grenze als (territoriale) Binarität bricht und einen alternativen Grenzbegriff stark macht: Grenze wird hier in eine Vielzahl gesellschaftlicher Prozesse eingelagert, die wandelbar und gestaltbar sind, sich transskalar und in umkämpfter Weise aufeinander beziehen und in ih-rem komplexen Zusammenspiel Effekte der Einsetzung oder (De-)Stabilisierung von natio-nalen Grenzen hervorbringen. ‚Borderscapes‘ überführt Grenzen also analytisch in die Land-schaften ihrer multiplen Wirksamkeiten und Aushandlungen, die durchaus an ‚territorialen Ränder‘ stattfinden können, aber nicht zwangsläufig. Damit macht der Ansatz ein analyti-sches Angebot, das der „territorial trap“ (Agnew 1994) entkommt, für die Komplexität von Grenzen sensibilisiert und diese außerdem als Ressourcen betrachtet. Trotz der Bemühung ‚borderscapes‘ näher zu umreißen, kann der Ansatz nur schwer auf den Begriff gebracht werden. Die dargelegten Grundzüge stecken vielmehr einen theoretisch-konzeptionellen Rahmen ab, der komplexitätssensible Grenzforscher*innen orientiert und Spielräume für spezifische Aneignungen lässt. Solche werden abschließend anhand von Beispielen der kul-turwissenschaftlichen Grenzforschung vorgestellt und die konzeptionelle Offenheit des An-satzes, die sich besonders in method(ologi)schen Mehrdeutigkeiten widerspiegelt, kritisch gewürdigt. [less ▲]

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See detailSchöne Digitale Welt: Analysen und Einsprüche (Rezension)
Baumann, Isabell Eva UL

in MEDIENwissenschaft: Rezensionen, Reviews (in press)

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See detailLog-based Slicing for System-level Test Cases
Messaoudi, Salma UL; Shin, Donghwan UL; Panichella, Annibale et al

in 2021 ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA) (in press)

Regression testing is arguably one of the most important activities in software testing. However, its cost-effectiveness and usefulness can be largely impaired by complex system test cases that are poorly ... [more ▼]

Regression testing is arguably one of the most important activities in software testing. However, its cost-effectiveness and usefulness can be largely impaired by complex system test cases that are poorly designed (e.g., test cases containing multiple test scenarios combined into a single test case) and that require a large amount of time and resources to run. One way to mitigate this issue is decomposing such system test cases into smaller, separate test cases---each of them with only one test scenario and with its corresponding assertions---so that the execution time of the decomposed test cases is lower than the original test cases, while the test effectiveness of the original test cases is preserved. This decomposition can be achieved with program slicing techniques, since test cases are software programs too. However, existing static and dynamic slicing techniques exhibit limitations when (1) the test cases use external resources, (2) code instrumentation is not a viable option, and (3) test execution is expensive. In this paper, we propose a novel approach, called DS3 (Decomposing System teSt caSe), which automatically decomposes a complex system test case into separate test case slices. The idea is to use test case execution logs, obtained from past regression testing sessions, to identify "hidden" dependencies in the slices generated by static slicing. Since logs include run-time information about the system under test, we can use them to extract access and usage of global resources and refine the slices generated by static slicing. We evaluated DS3 in terms of slicing effectiveness and compared it with a vanilla static slicing tool. We also compared the slices obtained by DS3 with the corresponding original system test cases, in terms of test efficiency and effectiveness. The evaluation results on one proprietary system and one open-source system show that DS3 is able to accurately identify the dependencies related to the usage of global resources, which vanilla static slicing misses. Moreover, the generated test case slices are, on average, 3.56 times faster than original system test cases and they exhibit no significant loss in terms of fault detection effectiveness. [less ▲]

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See detailReconceptualizing the Multilingual Child: Curriculum Construction in Luxembourg
Sattler, Sabrina UL

in Roberts, Philip; Brennan, Marie; Green, Bill (Eds.) Curriculum Challenges and Opportunities in a Changing World (in press)

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See detailThe Role of Teachers in Students’ Social Inclusion in the Classroom
Gasser, Luciano; Cillessen, Antonius H.N.; Huber, Christian et al

in Frontiers in Education (in press)

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See detailSISTA: Learning Optimal Transport Costs under Sparsity Constraints
Dupuy, Arnaud UL; Carlier, Guillaume; Galichon, Alfred et al

in Communications on Pure and Applied Mathematics (in press)

In this paper, we describe a novel iterative procedure called SISTA to learn the underlying cost in optimal transport problems. SISTA is a hybrid between two classical methods, coordinate descent (“S” ... [more ▼]

In this paper, we describe a novel iterative procedure called SISTA to learn the underlying cost in optimal transport problems. SISTA is a hybrid between two classical methods, coordinate descent (“S”-inkhorn) and proximal gradient descent (“ISTA”). It alternates between a phase of exact minimization over the transport potentials and a phase of proximal gradient descent over the parameters of the transport cost. We prove that this method converges linearly, and we illustrate on simulated examples that it is significantly faster than both coordinate descent and ISTA. We apply it to estimating a model of migration, which predicts the flow of migrants using country-specific characteristics and pairwise measures of dissimilarity between countries. This application demonstrates the effectiveness of machine learning in quantitative social sciences. [less ▲]

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See detailInputs from Hell: Learning Input Distributions for Grammar-Based Test Generation
Soremekun, Ezekiel UL; Pavese, Esteban; Havrikov, Nikolas et al

in IEEE Transactions on Software Engineering (in press)

Grammars can serve as producers for structured test inputs that are syntactically correct by construction. A probabilistic grammar assigns probabilities to individual productions, thus controlling the ... [more ▼]

Grammars can serve as producers for structured test inputs that are syntactically correct by construction. A probabilistic grammar assigns probabilities to individual productions, thus controlling the distribution of input elements. Using the grammars as input parsers, we show how to learn input distributions from input samples, allowing to create inputs that are similar to the sample; by inverting the probabilities, we can create inputs that are dissimilar to the sample. This allows for three test generation strategies: 1) “Common inputs” – by learning from common inputs, we can create inputs that are similar to the sample; this is useful for regression testing. 2) “Uncommon inputs” – learning from common inputs and inverting probabilities yields inputs that are strongly dissimilar to the sample; this is useful for completing a test suite with “inputs from hell” that test uncommon features, yet are syntactically valid. 3) “Failure-inducing inputs” – learning from inputs that caused failures in the past gives us inputs that share similar features and thus also have a high chance of triggering bugs; this is useful for testing the completeness of fixes. Our evaluation on three common input formats (JSON, JavaScript, CSS) shows the effectiveness of these approaches. Results show that “common inputs” reproduced 96% of the methods induced by the samples. In contrast, for almost all subjects (95%), the “uncommon inputs” covered significantly different methods from the samples. Learning from failure-inducing samples reproduced all exceptions (100%) triggered by the failure-inducing samples and discovered new exceptions not found in any of the samples learned from. [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 (DEON2020/2021, Munich) (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 ▲]

Detailed reference viewed: 83 (6 UL)