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See detailThe edge-based strain smoothing method for compressible and nearly incompressible non-linear elasticity for solid mechanics
Lee, Chang-Kye; Mihai, L. Angela; Kerfriden, Pierre et al

E-print/Working paper (in press)

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See detailYolanda von Vianden und das Yolanda-Epos
Sieburg, Heinz UL

E-print/Working paper (in press)

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See detailConvolution, aggregation and attention based deep neural networks for accelerating simulations in mechanics
Deshpande, Saurabh UL; Sosa, Raul Ian UL; Bordas, Stéphane UL et al

E-print/Working paper (2022)

Deep learning surrogate models are being increasingly used in accelerating scientific simulations as a replacement for costly conventional numerical techniques. However, their use remains a significant ... [more ▼]

Deep learning surrogate models are being increasingly used in accelerating scientific simulations as a replacement for costly conventional numerical techniques. However, their use remains a significant challenge when dealing with real-world complex examples. In this work, we demonstrate three types of neural network architectures for efficient learning of highly nonlinear deformations of solid bodies. The first two architectures are based on the recently proposed CNN U-NET and MAgNET (graph U-NET) frameworks which have shown promising performance for learning on mesh-based data. The third architecture is Perceiver IO, a very recent architecture that belongs to the family of attention-based neural networks–a class that has revolutionised diverse engineering fields and is still unexplored in computational mechanics. We study and compare the performance of all three networks on two benchmark examples, and show their capabilities to accurately predict the non-linear mechanical responses of soft bodies. [less ▲]

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See detailOptimal coalition splitting with heterogenous strategies
Boucekkine, Raouf; Camcho, Carmen; Ruan, Weihua et al

E-print/Working paper (2022)

We consider a group of players initially members of a coalition managing cooperatively a public bad, in this case, the stock of pollution. Countries are technologically heterogeneous but the pollution ... [more ▼]

We consider a group of players initially members of a coalition managing cooperatively a public bad, in this case, the stock of pollution. Countries are technologically heterogeneous but the pollution damage is uniform. We essentially attempt to characterize the conditions under which a country may eventually split and when it splits within an infinite horizon multi-stage differential game. In contrast to the existing literature, we do not assume that after splitting, the splitting player and the remaining coalition will adopt Markovian strategies. Instead, we assume that the latter will remain committed to the collective control of pollution and play open-loop, while the splitting player plays Markovian. Within a full linear-quadratic model, we characterize the optimal strategies. We later compare with the outcomes of the case where the splitting player and the remaining coalition play both Markovian. We highlight several interesting results in terms of the implications for long- term pollution levels and the duration of coalitions with heterogeneous strategies. [less ▲]

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See detailOptimal Timing of Carbon Capture and Storage Policies - a Social Planner's View
Chen, Yiwen; Wan, Xi; Zou, Benteng UL

E-print/Working paper (2022)

Carbon capture and storage (CCS) is considered one of the most realistic and plausible options for reducing greenhouse gas (GHG) emissions from large pollution sources. However, CCS deployment is costly ... [more ▼]

Carbon capture and storage (CCS) is considered one of the most realistic and plausible options for reducing greenhouse gas (GHG) emissions from large pollution sources. However, CCS deployment is costly. This paper considers the social cost of CCS projects and GHG damage from a central planer's point of view, providing clear information about when each player should deploy CCS. The findings are twofold: (1) given the heterogeneity of players, it is not socially optimal for all players to start CCS projects at the same time; instead, the player that has a cost advantage should start first; (2) it may be socially desirable for the player with a cost disadvantage never starts CCS. We show the conditions that support both possibilities. The second finding provides a clear policy guideline for the decision-maker: reduce the costs of the high-cost player in order to reduce global GHG emissions, provided that is the aim of the supranational institute. [less ▲]

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See detailA dynamic programming approach to optimal pollution control under uncertain irreversibility: The Poisson case
Boucekkine, Raouf; Ruan, Weihua; Zou, Benteng UL

E-print/Working paper (2022)

We solve a bimodal optimal control problem with a non-concavity and uncertainty through a Poisson process underlying the transition from a mode to another. We use a dynamic programming approach and are ... [more ▼]

We solve a bimodal optimal control problem with a non-concavity and uncertainty through a Poisson process underlying the transition from a mode to another. We use a dynamic programming approach and are able to uncover the global optimal dynamics (including optimal non-monotonic paths) under a few linear-quadratic assumption, which do not get rid of the non-concavity of the problem. This is in contrast to the related literature on pollution control under irreversibility which usually explores local dynamics along monotonic solution paths to first order Pontryagin conditions. [less ▲]

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See detailThe Geometry of Supersymmetry
Poncin, Norbert UL; Schouten, Sarah

E-print/Working paper (2022)

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See detailOptimal lockdown and vaccination policies to contain the spread of a mutating infectious disease
Prieur, Fabien; Ruan, Weihua; Zou, Benteng UL

E-print/Working paper (2022)

We develop a piecewise deterministic control model to study optimal lockdown and vaccination policies to manage a pandemic. Lockdown is modeled as an impulse control that allows the system to switch from ... [more ▼]

We develop a piecewise deterministic control model to study optimal lockdown and vaccination policies to manage a pandemic. Lockdown is modeled as an impulse control that allows the system to switch from one restriction regime of restrictions to another. Vaccination policy is a continuous control. Decisions are taken under the risk of mutations of the disease, with repercussions on the transmission rate. The decision maker follows a cost minimization objective. We first characterize the optimality conditions for impulse control and show how the prospect of a mutation affects the decision maker's choice by inducing her to anticipate the relative benefit of a regime change after a mutation has occurred. Under some parametric conditions, our problem admits infinitely many value functions. We show the existence of a minimum value function that is a natural candidate to the solution given the nature of the problem. Focusing on this specific value function, we finally study the features of the optimal policy, especially the timing of impulse control. We prove that uncertainty surrounding future \bad" vs. \good" mutation of the disease expedites vs. delays the adoption of lockdown measures. [less ▲]

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See detailDeep Learning for Ground and Non-ground Surface Separation: A Feature-based Semantic Segmentation Algorithm for Point Cloud Classification
Nurunnabi, Abdul Awal Md UL; Lindenbergh, Roderik; Teferle, Felix Norman UL

E-print/Working paper (2022)

Precise ground surface topography is crucial for 3D city analysis, digital terrain modeling, natural disaster monitoring, high-density map generation, and autonomous navigation to name a few. Deep ... [more ▼]

Precise ground surface topography is crucial for 3D city analysis, digital terrain modeling, natural disaster monitoring, high-density map generation, and autonomous navigation to name a few. Deep learning (DL; LeCun, et al., 2015), a division of machine learning (ML), has been achieving unparalleled success in image processing, and recently demonstrated a huge potential for point cloud analysis. This article presents a feature-based DL algorithm that classifies ground and non-ground points in aerial laser scanning point clouds. Recent advancements of remote sensing technologies make it possible digitizing the real world in a near automated fashion. LiDAR (Light Detection and Ranging) based point clouds that are a type of remotely sensed georeferenced data, providing detailed 3D information on objects and environment have been recognized as one of the most powerful means of digitization. Unlike imagery, point clouds are unstructured, sparse and of irregular data format which creates many challenges, but also provides huge opportunities for capturing geometric details of scanned surfaces with millimeter accuracy. Classifying and separating non-ground points from ground points largely reduce data volumes for consecutive analyses of either ground or non-ground surfaces, which consequently saves cost and labor, and simplifies further analysis. [less ▲]

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See detailWhy and when coalitions split? An alternative analytical approach with an application to environmental agreements
Boucekkine, Raouf; Camacho, Carmen; Ruan, Weihua et al

E-print/Working paper (2022)

We use a parsimonious two-stage differential game setting where the duration of the first stage, the coalition stage, depends on the will of a particular player to leave the coalition through an explicit ... [more ▼]

We use a parsimonious two-stage differential game setting where the duration of the first stage, the coalition stage, depends on the will of a particular player to leave the coalition through an explicit timing variable. By specializing in a standard linear-quadratic environmental model augmented with a minimal constitutional setting for the coalition (payoff share parameter), we are able to analytically extract several nontrivial findings. Three key aspects drive the results: the technological gap as an indicator of heterogeneity across players, the constitution of the coalition and the intensity of the public bad (here, the pollution damage). We provide with a full analytical solution to the two-stage differential game. In particular, we characterize the intermediate parametric cases leading to optimal nite time splitting. A key characteristic of these finite-time-lived coalitions is the requirement of the payoff share accruing to the splitting country to be large enough. Incidentally, our two-stage differential game setting reaches the conclusion that splitting countries are precisely those which use to benefit the most from the coalition. Constraining the payoff share to be low by Constitution may lead to optimal everlasting coalitions only provided initial pollution is high enough, which may cover the emergency cases we are witnessing nowadays. [less ▲]

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See detailSolvability of systems of invariant differential equations on H2 and beyond
Palmirotta, Guendalina UL; Olbrich, Martin UL

E-print/Working paper (2022)

We show how the Fourier transform for distributional sections of vector bundles over symmetric spaces of non-compact type G/K can be used for questions of solvability of systems of invariant differential ... [more ▼]

We show how the Fourier transform for distributional sections of vector bundles over symmetric spaces of non-compact type G/K can be used for questions of solvability of systems of invariant differential equations in analogy to Hörmander’s proof of the Ehrenpreis-Malgrange theorem. We get complete solvability for the hyperbolic plane H2 and partial results for products H^2 × · · · × H^2 and the hyperbolic 3-space H^3. [less ▲]

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See detailDie Vielfalt der Sozialen Arbeit in Luxemburg und die Arbeitsmarktzahlen 2021
Böwen, Petra UL; Flammang, Manou Laure

E-print/Working paper (2022)

Dieser Newsletter beschreibt den Arbeitsmarkt der Sozialen Arbeit in Luxemburg 2021, gibt einen Überblick über die Berufsqualifikationen und die Vielfalt der Praxisfelder und spezifischen Arbeitsbereiche.

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See detailEstimating a regression function in exponential families by model selection
Chen, Juntong UL

E-print/Working paper (2022)

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See detailPandemic Impacts on Sustainability and Hartwick’s Rule
Mavi, Can; Zou, Benteng UL

E-print/Working paper (2022)

In this study, we present a modified Hartwick rule encompassing the dynamics of pandemic, such as COVID-19. In our setting, the labor productivity gradually improves after the pandemic shock and may even ... [more ▼]

In this study, we present a modified Hartwick rule encompassing the dynamics of pandemic, such as COVID-19. In our setting, the labor productivity gradually improves after the pandemic shock and may even go beyond its pre-pandemic level due to the remote work and digitalization as also suggested by the empirical evidence. We demonstrate that a gradual labor productivity increase helps to conserve natural resources. We provide a theoretical foundation for a“sooner-the-better" strategy to control a pandemic, and we show that policy maker should implement a “whatever it costs” response to ensure that the transmission rate of the virus is below the recovery rate from the very beginning of the pandemic. Otherwise, the economy cannot have a sustained utility. We also analyze the implications of an “uncertain” pandemic on the intertemporal dynamics of natural resource and capital accumulation under the maximin criterion. Another important finding is that there exists a new economic and public health trade-off since a strong prevention policy is shown to decrease capital accumulation. [less ▲]

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See detailDelorme’s intertwining conditions for sections of homogeneous vector bundles on two and three dimensional hyperbolic spaces
Palmirotta, Guendalina UL; Olbrich, Martin UL

E-print/Working paper (2022)

The description of the Paley-Wiener space for compactly supported smooth functions C_c^∞(G) on a semi-simple Lie group G involves certain intertwining conditions that are difficult to handle. In the ... [more ▼]

The description of the Paley-Wiener space for compactly supported smooth functions C_c^∞(G) on a semi-simple Lie group G involves certain intertwining conditions that are difficult to handle. In the present paper, we make them completely explicit for G = SL(2, R)^d (d ∈ N) and G = SL(2, C). Our results are based on a defining criterion for the Paley-Wiener space, valid for general groups of real rank one, that we derive from Delorme’s proof of the Paley-Wiener theorem. In a forthcoming paper, we will show how these results can be used to study solvability of invariant differential operators between sections of homogeneous vector bundles over the corresponding symmetric spaces. [less ▲]

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See detailFINCITY -- Excerpt from project description
Hesse, Markus UL; Dörry, Sabine; Sigler, Thomas

E-print/Working paper (2022)

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See detailTowards Generalizable Machine Learning for Chest X-ray Diagnosis with Multi-task learning
Ghamizi, Salah UL; Garcia Santa Cruz, Beatriz UL; Temple, Paul et al

E-print/Working paper (2022)

Clinicians use chest radiography (CXR) to diagnose common pathologies. Automated classification of these diseases can expedite analysis workflow, scale to growing numbers of patients and reduce healthcare ... [more ▼]

Clinicians use chest radiography (CXR) to diagnose common pathologies. Automated classification of these diseases can expedite analysis workflow, scale to growing numbers of patients and reduce healthcare costs. While research has produced classification models that perform well on a given dataset, the same models lack generalization on different datasets. This reduces confidence that these models can be reliably deployed across various clinical settings. We propose an approach based on multitask learning to improve model generalization. We demonstrate that learning a (main) pathology together with an auxiliary pathology can significantly impact generalization performance (between -10% and +15% AUC-ROC). A careful choice of auxiliary pathology even yields competitive performance with state-of-the-art models that rely on fine-tuning or ensemble learning, using between 6% and 34% of the training data that these models required. We, further, provide a method to determine what is the best auxiliary task to choose without access to the target dataset. Ultimately, our work makes a big step towards the creation of CXR diagnosis models applicable in the real world, through the evidence that multitask learning can drastically improve generalization. [less ▲]

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See detailDer Arbeitsmarkt der Sozialen Arbeit 2020 = Le marché de l'emploi du secteur social en 2020
Böwen, Petra UL; Flammang, Manou Laure UL

E-print/Working paper (2022)

Dieser Newsletter beschreibt den Arbeitsmarkt der Sozialen Arbeit in Luxemburg 2020 und die Entwicklung der Zahlen in einigen Bereichen für 2018 bis 2020. Die Daten stammen von einem fortlaufenden ... [more ▼]

Dieser Newsletter beschreibt den Arbeitsmarkt der Sozialen Arbeit in Luxemburg 2020 und die Entwicklung der Zahlen in einigen Bereichen für 2018 bis 2020. Die Daten stammen von einem fortlaufenden Forschungsprojekt des PraxisBüros der Universität Luxemburg. Der Newsletter stellt eine Auswahl an Statistiken dar, z.B. bezüglich der meist gefragten Qualifikationsniveaus, der Verteilung der Praxisfelder, der Verteilung der Stellenangebote zwischen öffentlichen, kommunalen, gemeinnützigen und privaten Trägern und der erfassten enormen Diskrepanz zwischen Nachfrage und Angebot an qualifizierten Professionellen in der Sozialen Arbeit. Desweiteren werden Entwicklungstrends- vor allem zu Thema Aus- und Weiterbildung aufgezeigt. [less ▲]

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See detailThe Irreversible Pollution Game
Boucekkine, Raouf; Ruan, Weihua; Zou, Benteng UL

E-print/Working paper (2022)

We study a 2-country differential game with irreversible pollution. Irresability is of a hard type: above a certain threshold level of pollution, the self-cleaning capacity of Nature drops to zero ... [more ▼]

We study a 2-country differential game with irreversible pollution. Irresability is of a hard type: above a certain threshold level of pollution, the self-cleaning capacity of Nature drops to zero. Accordingly, the game includes a non-concave feature, and we characterize both the cooperative and non-cooperative versions with this general non-LQ property. We deliver full analytical results for the existence of Markov Perfect Equilibria. We first demonstrate that when pollution costs are equal across players (symmetry), irreversible pollution regimes are more frequently reached than under cooperation. Second, we study the implications of asymmetry in the pollution cost. We find far nontrivial results on the reachability of the irreversible regime. However, we unambiguously prove that, for the same total cost of pollution, provided the irreversible regime is reached in both the symmetric and asymmetric cases, long-term pollution is larger in the symmetric case, reflecting more intensive free-riding under symmetry. [less ▲]

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See detailTRADE SECRET PROTECTION AND R&D INVESTMENT OF FAMILY FIRMS
Hussinger, Katrin UL; Issah, Wunnam

E-print/Working paper (2022)

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See detailTOWARDS A EUROPEAN SOCIAL TAXONOMY: A SCORECARD APPROACH
Bodellini, Marco UL

E-print/Working paper (2022)

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See detailDLT-Based Enhancement of Cross-Border Payment Efficiency – a Legal and Regulatory Perspective
Zetzsche, Dirk Andreas UL; Anker-Sorensen, Linn; Passador, Maria et al

E-print/Working paper (2022)

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See detailBuilding Regional Payment Areas: The Single Rule Book Approach
Zetzsche, Dirk Andreas UL; Lammer, Thomas; Gazi, S. et al

E-print/Working paper (2022)

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See detailA restless badit approach for capacitated condition based maintenance scheduling
Demirci, Ece; Arts, Joachim UL; Van Houtum, Geert-Jan

E-print/Working paper (2022)

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See detailA topological Paley-Wiener-Schwartz Theorem for sections of homogeneous vector bundles on G/K
Palmirotta, Guendalina UL; Olbrich, Martin UL

E-print/Working paper (2022)

We study the Fourier transform for compactly supported distributional sections of complex homogeneous vector bundles on symmetric spaces of non-compact type X = G/K. We prove a characterisation of their ... [more ▼]

We study the Fourier transform for compactly supported distributional sections of complex homogeneous vector bundles on symmetric spaces of non-compact type X = G/K. We prove a characterisation of their range. In fact, from Delorme’s Paley-Wiener theorem for compactly supported smooth functions on a real reductive group of Harish-Chandra class, we deduce topological Paley-Wiener and Paley-Wiener- Schwartz theorems for sections. [less ▲]

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See detailWavelet methods to study the pointwise regularity of the generalized Rosenblatt process
Daw, Lara UL; Loosveldt, Laurent UL

E-print/Working paper (2022)

We prove that we can identify three types of pointwise behaviour in the regularity of the (generalized) Rosenblatt process. This extends to a non Gaussian setting previous results known for the ... [more ▼]

We prove that we can identify three types of pointwise behaviour in the regularity of the (generalized) Rosenblatt process. This extends to a non Gaussian setting previous results known for the (fractional) Brownian motion. On this purpose, fine bounds on the increments of the Rosenblatt process are needed. Our analysis is essentially based on various wavelet methods. [less ▲]

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See detailHow Patent Rights Affect University Science
Berge, Laurent; Doherr, Thorsten; Hussinger, Katrin UL

E-print/Working paper (2022)

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See detailTHE EU SUSTAINABLE FINANCE FRAMEWORK IN LIGHT OF INTERNATIONAL STANDARDS
Bodellini, Marco UL

E-print/Working paper (2022)

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See detailTRADE SECRET PROTECTION AND R&D INVESTMENT OF FAMILY FIRMS
Hussinger, Katrin UL; Issah, Abdul-Basit UL

E-print/Working paper (2022)

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See detailThe Impact of the Asset Purchase Programme on Systemic Risk in the Euro Area: Is There a Threat?
Chavarro Sanchez, Leidy; Nadal De Simone, Francisco; Lehnert, Thorsten UL

E-print/Working paper (2021)

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See detailDiversity on the screen
Zanaj, Skerdilajda UL

E-print/Working paper (2021)

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See detailAuswirkungen der Covid-19-Krise auf die Soziale Arbeit in Luxemburg aus Sicht der Praxis : Ergebnisse einer Online-Befragung im Sommer 2020
Flammang, Manou Laure UL; Böwen, Petra UL

E-print/Working paper (2021)

This publication presents the findings of an online survey on the impact of the Covid-19 crisis on social work in Luxembourg from the perspective of practitioners. It shows what effects the crisis as well ... [more ▼]

This publication presents the findings of an online survey on the impact of the Covid-19 crisis on social work in Luxembourg from the perspective of practitioners. It shows what effects the crisis as well as the hygiene and protection measures had on daily social work practice, on the addressees and on the practitioners themselves. The findings are then reflected upon and discussed in relation to international research findings and professional publications on the topic of social work in times of Covid-19. [less ▲]

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See detailEarthquakes and Mental Health
Bertinelli, Luisito UL; Mahé, Clotilde; Strobl, Eric

E-print/Working paper (2021)

Earthquakes may seriously deteriorate mental health by generating fear and stress as a result of economic and human losses. However, mental health has also been found to improve as a result of greater ... [more ▼]

Earthquakes may seriously deteriorate mental health by generating fear and stress as a result of economic and human losses. However, mental health has also been found to improve as a result of greater social cohesion in affected communities after the event. We examine the short-run effects of earthquakes on a wide set of mental health outcomes in Ecuador. To this end, we combine hospital admissions, death records, and survey data with precise measures of local seismic activity to exploit the plausibly random spatial and temporal nature of earthquake intensity. We find that damaging earthquakes decrease the propensity to be admitted, the number of days of hospitalisation for mental and behavioural disorders, and deaths due to suicide. Estimates from nationally-representative surveys provide suggestive evidence of increased life satisfaction, trust, and religious observance, and thus provide a possible explanation for the fall in admissions and suicides after an earthquake. [less ▲]

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See detailA global carbon tax? Why firm mobility and heterogeneity matters
Zanaj, Skerdilajda UL

E-print/Working paper (2021)

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See detailThe role of economic complexity on the formation of gender roles
Zanaj, Skerdilajda UL

E-print/Working paper (2021)

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See detailRequirements And Threat Models of Adversarial Attacks and Robustness of Chest X-ray classification
Ghamizi, Salah UL; Cordy, Maxime UL; Papadakis, Mike UL et al

E-print/Working paper (2021)

Vulnerability to adversarial attacks is a well-known weakness of Deep Neural Networks. While most of the studies focus on natural images with standardized benchmarks like ImageNet and CIFAR, little ... [more ▼]

Vulnerability to adversarial attacks is a well-known weakness of Deep Neural Networks. While most of the studies focus on natural images with standardized benchmarks like ImageNet and CIFAR, little research has considered real world applications, in particular in the medical domain. Our research shows that, contrary to previous claims, robustness of chest x-ray classification is much harder to evaluate and leads to very different assessments based on the dataset, the architecture and robustness metric. We argue that previous studies did not take into account the peculiarity of medical diagnosis, like the co-occurrence of diseases, the disagreement of labellers (domain experts), the threat model of the attacks and the risk implications for each successful attack. In this paper, we discuss the methodological foundations, review the pitfalls and best practices, and suggest new methodological considerations for evaluating the robustness of chest xray classification models. Our evaluation on 3 datasets, 7 models, and 18 diseases is the largest evaluation of robustness of chest x-ray classification models. We believe our findings will provide reliable guidelines for realistic evaluation and improvement of the robustness of machine learning models for medical diagnosis. [less ▲]

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See detailLabor Market Effects of Technology Shocks biased Toward the Traded Sector
Bertinelli, Luisito UL; Cardi; Restout

E-print/Working paper (2021)

Motivated by recent evidence pointing at an increasing contribution of asymmetric shocks across sectors to economic fluctuations, we explore the labor market effects of technology shocks biased toward the ... [more ▼]

Motivated by recent evidence pointing at an increasing contribution of asymmetric shocks across sectors to economic fluctuations, we explore the labor market effects of technology shocks biased toward the traded sector. Our VAR evidence for seventeen OECD countries reveals that the non-traded sector alone drives the increase in total hours worked following a technology shock that increases permanently traded relative to non-traded TFP. The shock generates a reallocation of labor toward the non-traded sector which contributes to 35% on average of the rise in non-traded hours worked. Both labor reallocation and variations in labor income shares are found empirically connected with factor-biased technological change. Our quantitative analysis shows that a two-sector open economy model with flexible prices can reproduce the labor market effects we document empirically once we allow for imperfect mobility of labor, gross substitutability between home- and foreign-produced traded goods, and factor-biased technological change. When calibrating the model to country-specific data, its ability to account for the cross-country reallocation and redistributive effects we estimate increases once we let factor-biased technological change vary between sectors and across countries. [less ▲]

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See detailQKD parameter estimation by two-universal hashing leads to faster convergence to the asymptotic rate
Ostrev, Dimiter UL

E-print/Working paper (2021)

This paper proposes and proves security of a QKD protocol which uses two-universal hashing instead of random sampling to estimate the number of bit flip and phase flip errors. This protocol dramatically ... [more ▼]

This paper proposes and proves security of a QKD protocol which uses two-universal hashing instead of random sampling to estimate the number of bit flip and phase flip errors. This protocol dramatically outperforms previous QKD protocols for small block sizes. More generally, for the two-universal hashing QKD protocol, the difference between asymptotic and finite key rate decreases with the number $n$ of qubits as $cn^{-1}$, where $c$ depends on the security parameter. For comparison, the same difference decreases no faster than $c'n^{-1/3}$ for an optimized protocol that uses random sampling and has the same asymptotic rate, where $c'$ depends on the security parameter and the error rate. [less ▲]

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See detailImpact of mining boom on the quality of public goods in Sub-Saharan Africa
Bertinelli, Luisito UL; Bourgain, Arnaud UL

E-print/Working paper (2021)

In this paper, we investigate the impact of public mining revenues on perception indicators of public goods quality in five mining countries that have recently experienced a boom in their government ... [more ▼]

In this paper, we investigate the impact of public mining revenues on perception indicators of public goods quality in five mining countries that have recently experienced a boom in their government revenues: Burkina Faso, Ghana, D.R. Congo, Tanzania, and Zambia. The effect of the tax revenue boom is identified using a difference-in-differences estimation strategy. Our estimations indicate that people living in mining regions as having a sense of structural disadvantage in terms of the provision of public goods; however, this perception is pro-cyclical in the presence of resource booms/busts. Our results hold even after taking account of the possible endogeneity of our measure of resource revenue. [less ▲]

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See detailEvaluation of TPMS Signal Propagation in a Heavy Commercial Vehicle Environement
Rida, Ahmad UL; Ridha, Soua; Engel, Thomas UL

E-print/Working paper (2021)

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See detailCovid-Kids II. Survey for children aged 6 to 16 about their experiences during the Covid-19 pandemic
Kirsch, Claudine UL; Peluso, Eugenio; Andreoli, Francesco et al

E-print/Working paper (2021)

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See detailThe good, the bad, and the asymmetric: Evidence from a new conditional density model
Kostyrka, Andreï UL; Malakhov, Dmitry

E-print/Working paper (2021)

We propose a novel univariate conditional density model and decompose asset returns into a sum of copula-connected unobserved ‘good’ and ‘bad’ shocks. The novelty of this approach comes from two factors ... [more ▼]

We propose a novel univariate conditional density model and decompose asset returns into a sum of copula-connected unobserved ‘good’ and ‘bad’ shocks. The novelty of this approach comes from two factors: we explicitly model correlation between unobserved shocks and allow for the presence of copula-connected discrete jumps. The proposed framework is very flexible and subsumes other models, such as ‘bad environments, good environments’. Our model shows certain hidden characteristics of returns, explains investors’ behaviour in greater detail, and yields better forecasts of risk measures. The in-sample and out-of-sample performance of our model is better than that of 40 popular GARCH variants. A Monte-Carlo simulation shows that the proposed model recovers the structural parameters of the unobserved dynamics. We estimate the model on S&P 500 data and find that time-dependent non-negative covariance between ‘good’ and ‘bad’ shocks with a leverage-like effect is an important component of total variance. Asymmetric reaction to shocks is present almost in all characteristics of returns. Conditional distribution of seems to be very time-dependent with skewness both in the centre and tails. We conclude that continuous shocks are more important than discrete jumps at least at daily frequency. [less ▲]

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See detailInsider’s problem in the trinomial model: a discrete jump process point of view
Halconruy, Hélène UL

E-print/Working paper (2021)

In an incomplete market underpinned by the trinomial model, we consider two investors: an ordinary agent whose decisions are driven by public information and an insider who possesses from the beginning a ... [more ▼]

In an incomplete market underpinned by the trinomial model, we consider two investors: an ordinary agent whose decisions are driven by public information and an insider who possesses from the beginning a surplus of information encoded through a random variable for which he or she knows the outcome. Through the definition of an auxiliary model based on a marked binomial process, we handle the trinomial model as a volatility one, and use the stochastic analysis and Malliavin calculus toolboxes available in that context. In particular, we connect the information drift, i.e. the drift to eliminate in order to preserve the martingale property within an initial enlargement of filtration in terms of Malliavin’s derivative. We solve explicitly the agent and the insider expected logarithmic utility maximization problems and provide a Ocone-Karatzas type formula for replicable claims. We identify insider’s expected additional utility with the Shannon entropy of the extra information, and examine then the existence of arbitrage opportunities for the insider. [less ▲]

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See detailLes langues dans les offres d'emploi au Luxembourg (1984-2019)
Pigeron-Piroth, Isabelle UL; Fehlen, Fernand UL

E-print/Working paper (2021)

À partir d’un échantillon d’offres d’emploi publiées dans le Luxemburger Wort, portant sur la période 1984-2019, cette étude décrit l’évolution des compétences linguistiques exigées ou souhaitées sur le ... [more ▼]

À partir d’un échantillon d’offres d’emploi publiées dans le Luxemburger Wort, portant sur la période 1984-2019, cette étude décrit l’évolution des compétences linguistiques exigées ou souhaitées sur le marché du travail du Luxembourg. Après une présentation contextuelle de la situation linguistique et de l’emploi au Luxembourg, l’analyse empirique des quelques 8 340 offres d’emploi de notre échantillon constitue le cœur de cette publication. Aux divers tableaux et graphiques illustrant notre propos s’ajoutent des décryptages de la sémantique utilisée dans les offres d’emploi publiées, utiles à la compréhension des besoins linguistiques dans un marché du travail plurilingue et international. [less ▲]

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See detailAdaptively Secure Laconic Function Evaluation for NC1
Agrawal, Shweta; Rosie, Razvan UL

E-print/Working paper (2021)

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See detailThe very long arm of wealth: Effects of intergenerational wealth resources on health in the U.S. over the last three decades
Chauvel, Louis UL; Ceron, Francisco UL; Murphy, Emily UL et al

E-print/Working paper (2021)

Health inequalities result from multidimensional socioeconomic inequalities (income, education, wealth, etc.). Given the specific size and greater stability through time of wealth than income, wealth ... [more ▼]

Health inequalities result from multidimensional socioeconomic inequalities (income, education, wealth, etc.). Given the specific size and greater stability through time of wealth than income, wealth might affect health beyond other socioeconomic indicators. An important question is how far the reach of wealth is on one’s health: Does wealth promote health even over generations? Using the Panel Study of Income Dynamics (PSID), we consider the effects of intergenerational and intragenerational wealth on age-adjusted self-assessed health (ASAH) across the life course. We find that both parental and personal household wealth strongly affect ASAH net of other socioeconomic measures. Just as social disadvantages have been shown to be inherited between generations, so too are wealth-induced health advantages. Furthermore, the inter- and intra- generational wealth effects on health increase over the life course. This study thus encourages social scientists to pay greater attention to wealth inequalities, despite difficulties in their accurate measurement. [less ▲]

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See detailLooking for the `Best and Brightest': Hiring difficulties and high-skilled foreign workers
Raux, Morgan UL

E-print/Working paper (2021)

This paper studies the complementarity between domestic and foreign skilled workers. It develops a simple model where employers seek to recruit a foreign worker when finding domestic workers takes more ... [more ▼]

This paper studies the complementarity between domestic and foreign skilled workers. It develops a simple model where employers seek to recruit a foreign worker when finding domestic workers takes more time. This paper confirms the predictions of the model. I rely on a within-firm within-occupation identification strategy to compare recruitment decisions made by a given employer for similar positions that differ in job posting duration. To identify this relationship, I have collected and assembled a new and original dataset at the job level. I match online job postings to administrative data on labor condition applications (LCAs) submitted as the first step in applying for H-1B temporary skilled worker visas. I find that employers are 28 percent more likely to submit an LCA when the job posting duration is one standard deviation longer. I provide evidence suggesting that this phenomenon is due to insufficient domestic labor supply in these occupations. [less ▲]

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See detailCloturing Deliberation
Anesi, Vincent UL; Safronov, Mikhail

E-print/Working paper (2021)

We study how the institutional arrangements for ending deliberation --- the "cloture rules" --- interact with collective learning to affect the outcomes of decision making in committees. In contrast to ... [more ▼]

We study how the institutional arrangements for ending deliberation --- the "cloture rules" --- interact with collective learning to affect the outcomes of decision making in committees. In contrast to much of the previous literature on deliberative commit tees, this paper makes a distinction between the final votes over policy proposals and the cloture votes that bring them about. Using this approach, we explore how cloture rules influence the course of deliberation, the likelihood of inefficient deliberative outcomes, the circumstances surrounding failures to bring proposals to a final vote, and the distribution of power among committee members in the deliberative process. We also use our simple model to examine the issue of the stability of cloture rules, characterizing the rules that no coalition of committee members is able or willing to overturn. We show in particular that all cloture rules are dynamically stable. [less ▲]

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See detailCultural differences and immigrants' wages
Raux, Morgan UL

E-print/Working paper (2021)

In this paper, I investigate how cultural differences affect the labor-market performance of immigrant workers in Germany. I document a negative relationship between hourly wages and the cultural distance ... [more ▼]

In this paper, I investigate how cultural differences affect the labor-market performance of immigrant workers in Germany. I document a negative relationship between hourly wages and the cultural distance between immigrants' countries of origin and Germany. This result is robust across the three main indicators used in the gravity literature: linguistic, religious, and genetic distances. This cultural wage penalty disappears after five to ten years spent in Germany. Controlling for language proficiency as well as for selective in- and out-migration, these results highlight the cultural integration of immigrant workers. I finally provide evidence suggesting that lower wage progression may be explained by fewer job-to-job transitions. [less ▲]

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See detailEnvironmental Culture and Economic Complexity
Zanaj, Skerdilajda UL

E-print/Working paper (2021)

Detailed reference viewed: 252 (41 UL)
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See detailPost-Quantum Secure LFE for L/poly with Smaller Parameters
Naccache, David; Rosie, Razvan UL; Spignoli, Lorenzo UL

E-print/Working paper (2021)

Detailed reference viewed: 171 (7 UL)
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See detailRobust Estimation in Finite Mixture Models
Lecestre, Alexandre UL

E-print/Working paper (2021)

Detailed reference viewed: 206 (44 UL)
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See detailGenetic Diversity and Performance: Evidence From Football Data
Zanaj, Skerdilajda UL; Beine, Michel UL; Peracchi, Silvia UL

E-print/Working paper (2021)

Detailed reference viewed: 213 (23 UL)
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See detailIndeterminacies and models of homotopy limits
Govzmann, Alisa UL; Pistalo, Damjan UL; Poncin, Norbert UL

E-print/Working paper (2021)

Detailed reference viewed: 89 (14 UL)
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See detailThe Long-Term Effect of Research Grants on the Scientific Output of University Professors
Hussinger, Katrin UL; Carvalho, J.N.

E-print/Working paper (2021)

Detailed reference viewed: 130 (9 UL)
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See detailThe Hidden Lattice Problem
Notarnicola, Luca UL; Wiese, Gabor UL

E-print/Working paper (2021)

We consider the problem of revealing a small hidden lattice from the knowledge of a low-rank sublattice modulo a given sufficiently large integer -- the {\em Hidden Lattice Problem}. A central motivation ... [more ▼]

We consider the problem of revealing a small hidden lattice from the knowledge of a low-rank sublattice modulo a given sufficiently large integer -- the {\em Hidden Lattice Problem}. A central motivation of study for this problem is the Hidden Subset Sum Problem, whose hardness is essentially determined by that of the hidden lattice problem. We describe and compare two algorithms for the hidden lattice problem: we first adapt the algorithm by Nguyen and Stern for the hidden subset sum problem, based on orthogonal lattices, and propose a new variant, which we explain to be related by duality in lattice theory. Following heuristic, rigorous and practical analyses, we find that our new algorithm brings some advantages as well as a competitive alternative for algorithms for problems with cryptographic interest, such as Approximate Common Divisor Problems, and the Hidden Subset Sum Problem. Finally, we study variations of the problem and highlight its relevance to cryptanalysis. [less ▲]

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See detailLes reliques des "martyrs de Gorcum" à Bruxelles
Weis, Monique UL; Houssiau, Jean

E-print/Working paper (2021)

Detailed reference viewed: 27 (2 UL)
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See detailFrom Centralized to Decentralized Finance: The Issue of “Fake-DeFi”
Zetzsche, Dirk Andreas UL; Anker-Sorensen, Linn

E-print/Working paper (2021)

Detailed reference viewed: 60 (3 UL)
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See detailA Principles-based Approach to the Governance of BigFintechs
Zetzsche, Dirk Andreas UL; Arner, Douglas; Buckley, Ross et al

E-print/Working paper (2021)

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See detailThe EU Sustainable Finance Framework in Light of International Standards
Zetzsche, Dirk Andreas UL; Bodellini, Marco UL; Consiglio, Roberta

E-print/Working paper (2021)

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See detailPROJECT WARLUX Ambiguities in biographies of Luxembourgish conscripts during and after WWII
Janz, Nina UL

E-print/Working paper (2021)

More than 10,000 Luxembourgish soldiers and recruits and an unknown number of Luxembourgish men and women wore German uniforms during WWII in armed forces and civil organisations, such as the Wehrmacht ... [more ▼]

More than 10,000 Luxembourgish soldiers and recruits and an unknown number of Luxembourgish men and women wore German uniforms during WWII in armed forces and civil organisations, such as the Wehrmacht, Waffen-SS, armed police forces and the Reichsarbeitsdienst (RAD). The "WARLUX" project, based at the University of Luxembourg in the Luxembourg Centre for Contemporary and Digital History (C2DH), intends to collect the biographical data of Luxembourgers who were drafted into the German Army and the Labour Service. Around 3,000 young men and women are used in a case study to research their biographies and individual stories during the war, highlight different approaches to researching World War II, and show different résumés and personal experiences during this period. WARLUX aims to review the categories that have tended to be used in the national history discourse. For these women and men were called different like "forced recruit", "volunteer", "réfractaire" and "déserteur" were used, next to mentions of "Mort la patrie" for whom who died in German uniform. Are these terms appropriate to describe the experiences of these individuals, or do they need to be elucidated and challenged? Who were the people behind these abstract terms? What were their individual experiences, stories, reactions, choices, contradictions and survival strategies during and after World War II (Tames 2016)? The term "forced recruit" has come to suggest the general victim status of all conscripted Luxembourgish soldiers. In this content between the dualism of the official narrative and the historiography of the last decades, the project WARLUX wants to apply another concept: "situative opportunism", to question the cumulative heroism and the power of collective forms of decision-making in "forced environments", like the enrolment of young women and men (Fickers/Brüll, 2019). Following the biographical approach by analysing documents and personal views (letters, diaries), Andreas Fickers and Christoph Brüll (2019) use the term "situative opportunism" to emphasise the link between biographical research and sociological decision theory. Based on Schimank (2005), the authors state that every historical actor has multiple options in a complex decision-making process; these decisions are not necessarily egoist, neither the result of external constraints, but grounded in a situational logic of doing what seems most suitable in this very moment. The project is still in the initial phase but will soon deepen the analysis of the biographies of the individuals using the term "situational opportunism". With the application for the conference, the project team would like to discuss other approaches and start an exchange about other/opposite concepts. [less ▲]

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See detailAdversarial Robustness in Multi-Task Learning: Promises and Illusions
Ghamizi, Salah UL; Cordy, Maxime UL; Papadakis, Mike UL et al

E-print/Working paper (2021)

Vulnerability to adversarial attacks is a well-known weakness of Deep Neural networks. While most of the studies focus on single-task neural networks with computer vision datasets, very little research ... [more ▼]

Vulnerability to adversarial attacks is a well-known weakness of Deep Neural networks. While most of the studies focus on single-task neural networks with computer vision datasets, very little research has considered complex multi-task models that are common in real applications. In this paper, we evaluate the design choices that impact the robustness of multi-task deep learning networks. We provide evidence that blindly adding auxiliary tasks, or weighing the tasks provides a false sense of robustness. Thereby, we tone down the claim made by previous research and study the different factors which may affect robustness. In particular, we show that the choice of the task to incorporate in the loss function are important factors that can be leveraged to yield more robust models. [less ▲]

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See detailStrategic Behavior in a Serial Newsvendor Setting
Perez Becker, Nicole UL; Mantin, Benny UL; Arts, Joachim UL

E-print/Working paper (2021)

Detailed reference viewed: 158 (14 UL)
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See detailRedefining resilience: Integrative review and development of an assessment tool
Mantin, Benny UL

E-print/Working paper (2021)

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See detailTax competition and phantom FDI
Zanaj, Skerdilajda UL

E-print/Working paper (2021)

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See detailCommon pool resource management and risk perceptions
Mavi, Can Askan UL; Quérou, Nicolas

E-print/Working paper (2020)

Motivated by recent discussions about the issue of risk perceptions for climate change related events, we introduce a non-cooperative game setting where agents manage a common pool resource under a ... [more ▼]

Motivated by recent discussions about the issue of risk perceptions for climate change related events, we introduce a non-cooperative game setting where agents manage a common pool resource under a potential risk, and agents exhibit different risk perception biases. Focusing on the effect of the polarization level and other population features, we show that the type of bias (overestimation versus underestimation biases) and the resource quality level before and after the occurrence of the shift have first-order importance on the qualitative nature of behavioral adjustments and on the pattern of resource conservation. When there are non-uniform biases within the population, the intra-group structure of the population qualitatively affects the degree of resource conservation. Moreover, unbiased agents may react in nonmonotone ways to changes in the polarization level when faced with agents exhibiting different types of bias. The size of the unbiased agents’ sub-population does not qualitatively affect how an increase in the polarization level impacts individual behavioral adjustments, even though it affects the magnitude of this change. Finally, it is shown how perception biases affect the comparison between centralized and decentralized management. [less ▲]

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See detailTHIS TIME IS REALLY DIFFERENT: FLIGHT-TO-SAFETY AND THE COVID-19 CRISIS
Löwen, Celina; Kchouri, Bilal UL; Lehnert, Thorsten UL

E-print/Working paper (2020)

Detailed reference viewed: 126 (15 UL)
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See detailLinear Z2n-Manifolds and Linear Actions
Bruce, Andrew UL; Ibarguengoytia, Eduardo UL; Poncin, Norbert UL

E-print/Working paper (2020)

Detailed reference viewed: 97 (13 UL)
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See detailRobust Estimation of a Regression Function in Exponential Families
Baraud, Yannick UL; Chen, Juntong UL

E-print/Working paper (2020)

Detailed reference viewed: 263 (67 UL)
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See detailThe Luxembourg COVID-Kids questionnaire
Kirsch, Claudine UL; Engel de Abreu, Pascale UL; Neumann, Sascha UL

E-print/Working paper (2020)

Detailed reference viewed: 151 (19 UL)
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See detailDer Arbeitsmarkt der Sozialen Arbeit 2019 = Le marché de l'emploi du secteur social en 2019
Böwen, Petra UL; Flammang, Manou Laure UL

E-print/Working paper (2020)

This newsletter describes the job market in the social work sector in Luxembourg in 2019. The data are derived from an ongoing research project by the PraxisBüro of the University of Luxembourg. The ... [more ▼]

This newsletter describes the job market in the social work sector in Luxembourg in 2019. The data are derived from an ongoing research project by the PraxisBüro of the University of Luxembourg. The newsletter presents a selection of statistics concerning for example the most sought after qualification levels, the distribution of practice fields, the distribution of job offers on public, municipal, privat an non-governmental organisations an the documented gab between the demand of social workers with a Bachelor diploma and the number of Bachelor diplomas issued in Luxembourg [less ▲]

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See detailDynamics of Achievement inequalities: the role of performance and choice in Chile
Ceron, Francisco UL; Bol, Thijs; Van de Werfhorst, Herman

E-print/Working paper (2020)

Research on education inequalities has long-established the relationship between the social composition of of schools and achievement levels. However, the empirical study of the social processes in ... [more ▼]

Research on education inequalities has long-established the relationship between the social composition of of schools and achievement levels. However, the empirical study of the social processes in choosing schools and their potential effects on achievement inequalities has often been neglected. This article investigates the extent to which such social processes, related to parents’ educational preferences and expectations, influence the development of students’ achievement inequalities throughout their schooling career, through shaping school communities, as a channel of transmission of socioeconomic inequality. Using longitudinal census data from Chile, which allows us to observe students’ achievements between the 4th and 10th grades, we find support for the claim that the development of achievement inequalities operate partly through well-off parents’ educational preferences and expectations. Moreover, these preferences and beliefs explain most of the social composition effect of schools on achievement inequalities. We conclude that choice processes should be considered as an integral part of theories aimed to explain achievement inequalities as a dynamic process. [less ▲]

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See detailThe Lehman Sisters Claim
Lehnert, Thorsten UL

E-print/Working paper (2020)

I evaluate Christine Lagarde´s claim that more female leaders can be associated with more prudence, and less of the risky decision-making that had provoked the crisis. Indeed, the proportion of women who ... [more ▼]

I evaluate Christine Lagarde´s claim that more female leaders can be associated with more prudence, and less of the risky decision-making that had provoked the crisis. Indeed, the proportion of women who are employed in decision-making and management roles in governments, large enterprises and institutions varies substantially across European countries and is oftentimes below 30%. Research suggests that in addition to biological differences, men and women show morphological dissimilarities in specific brain regions, which explain the observed differences in behavior. As a result, female decision makers tend to be more risk averse, better suited to carefully analyze a problem, superior in multitasking and better in creating solutions that work for a group. Not surprisingly, firms with more female decision makers tend to outperform their peers in terms of productivity, profitability and stock performance while taking fewer risks. In this paper, I aim to explore the effect of female decision making on aggregate equity returns. Relying on an equilibrium asset-pricing model in an economy under jump diffusion, I decompose the moments of the returns of European stock market indices into a diffusive (systematic) risk and an (idiosyncratic) extreme event risk part. For a balanced panel of European countries, I find empirical evidence for a Lehman sisters’ effect: female decision making is an important determinant of (idiosyncratic) extreme event risk. As a result, stock markets in countries with more female decision makers are characterized by higher risk aversion, lower volatility and more positive return asymmetry, primarily driven by extreme event risk, e.g. the lower frequency of negative jumps. Results are robust to the inclusion of various controls for other country- or market-specific characteristics. [less ▲]

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See detailRetail Investors' Flight-From-Safety and the Skewness Risk Premium
Lehnert, Thorsten UL

E-print/Working paper (2020)

Detailed reference viewed: 117 (6 UL)
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See detailDeniable encryption, authentication, and key exchange
Ostrev, Dimiter UL

E-print/Working paper (2020)

We present some foundational ideas related to deniable encryption, message authentication, and key exchange in classical cryptography. We give detailed proofs of results that were previously only sketched ... [more ▼]

We present some foundational ideas related to deniable encryption, message authentication, and key exchange in classical cryptography. We give detailed proofs of results that were previously only sketched in the literature. In some cases, we reach the same conclusions as in previous papers; in other cases, the focus on rigorous proofs leads us to different formulations of the results. [less ▲]

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See detailFiscal effects of migrants in Europe: a quantile regression approach
Joxhe, Majlinda UL; Zanaj, Skerdilajda UL; Scaramozzino, Pasquale

E-print/Working paper (2020)

In this paper, we explore the fiscal impact of immigrants in Europe applying a quantile regression approach to data from the European Survey on Living Conditions (EU-SILC) for the period 2007-2015. Our ... [more ▼]

In this paper, we explore the fiscal impact of immigrants in Europe applying a quantile regression approach to data from the European Survey on Living Conditions (EU-SILC) for the period 2007-2015. Our estimations show that not only on average but also in almost all income quantiles, the fiscal position of both European and non-European migrants is not significantly different from that of native citizens. Furthermore, non-EU migrants are net contributors as compared to the corresponding native citizens in the Netherlands and Belgium for various quantiles. Lastly, we examine the link between migrants’ fiscal position and the fiscal perception of native European citizens measured using ESS data. We find a conflicting relationship: countries where migrants are perceived negatively are instead countries where they are net fiscal contributors and vice versa. [less ▲]

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See detailOptimized Collision Search for STARK-Friendly Hash Challenge Candidates
Udovenko, Aleksei UL

E-print/Working paper (2020)

In this note, we report several solutions to the STARK-Friendly Hash Challenge: a competition with the goal of finding collisions for several hash functions designed specifically for zero-knowledge proofs ... [more ▼]

In this note, we report several solutions to the STARK-Friendly Hash Challenge: a competition with the goal of finding collisions for several hash functions designed specifically for zero-knowledge proofs (ZKP) and multiparty computations (MPC). We managed to find collisions for 3 instances of 91-bit hash functions. The method used is the classic parallel collision search with distinguished points from van Oorshot and Wiener (1994). As this is a general attack on hash functions, it does not exhibit any particular weakness of the chosen hash functions. The crucial part is to optimize the implementations to make the attack cost realistic, and we describe several arithmetic tricks. [less ▲]

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See detailEstimating the number of infected persons
Baraud, Yannick UL; Nourdin, Ivan UL; Peccati, Giovanni UL

E-print/Working paper (2020)

The aim of this paper is to provide a confidence interval on the number of infected persons by COVID-19 within the population from the number of deaths reported in the hospitals and the mortality rate ... [more ▼]

The aim of this paper is to provide a confidence interval on the number of infected persons by COVID-19 within the population from the number of deaths reported in the hospitals and the mortality rate (that is assumed to be known). [less ▲]

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See detailLegal Readiness for Climate Finance: The case of Bangladesh towards a transition to climate resilience
Alexandraki, Chrysa UL

E-print/Working paper (2020)

Even though the Paris Agreement posits the need to align overall financial flows with low-carbon and climate-resilient development in the heart of its objectives, developing countries face ample ... [more ▼]

Even though the Paris Agreement posits the need to align overall financial flows with low-carbon and climate-resilient development in the heart of its objectives, developing countries face ample constraints in mitigating and adapting to climate change, while concomitantly embarking on reconciling the curbing of climate change with development concerns. Climate finance constitutes an enabling means not only for assisting developing countries in building capacities and enabling environments to address climate change in compliance with their commitments under the Paris Agreement, but most importantly for ushering a long-term development shift towards sustainability. This article furthers the discourse on what it means to be ‘legally ready’ for climate finance. It argues that legal reforms present a means to overcome legal barriers undermining climate finance effectiveness in developing countries, aimed at mainstreaming climate change considerations across all sectors and national policies, stimulating climate-related flows from all sources of finance, and instituting a paradigm shift towards climate-resilient development. First, it elaborates on the role of law in building climate finance readiness, the key legal barriers encountered in developing countries, and the main legal approaches and regulatory tools likely to enhance the four main capacities required to be ready for climate finance. Second, it illustrates the laws and policies currently implemented in Bangladesh concerning the country’s readiness for climate finance. The article concludes premised on the case study of Bangladesh that legal reforms are essential in developing countries, in order to ensure long-term climate finance effectiveness steering transformative changes. [less ▲]

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See detailApproximation of Riemannian measures by Stein’s method
Thompson, James UL

E-print/Working paper (2020)

Detailed reference viewed: 91 (2 UL)
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See detailOn the structure of symmetric $n$-ary bands
Devillet, Jimmy UL; Mathonet, Pierre

E-print/Working paper (2020)

We study the class of symmetric $n$-ary bands. These are $n$-ary semigroups $(X,F)$ such that $F$ is invariant under the action of permutations and idempotent, i.e., satisfies $F(x,\ldots,x)=x$ for all $x ... [more ▼]

We study the class of symmetric $n$-ary bands. These are $n$-ary semigroups $(X,F)$ such that $F$ is invariant under the action of permutations and idempotent, i.e., satisfies $F(x,\ldots,x)=x$ for all $x\in X$. We first provide a structure theorem for these symmetric $n$-ary bands that extends the classical (strong) semilattice decomposition of certain classes of bands. We introduce the concept of strong $n$-ary semilattice of $n$-ary semigroups and we show that the symmetric $n$-ary bands are exactly the strong $n$-ary semilattices of $n$-ary extensions of Abelian groups whose exponents divide $n-1$. Finally, we use the structure theorem to obtain necessary and sufficient conditions for a symmetric $n$-ary band to be reducible to a semigroup. [less ▲]

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See detailThe signature method : a new tool enhancing time series clustering
Clausel, Marianne; Lejay, Antoine; Terraza, Virginie UL

E-print/Working paper (2020)

Detailed reference viewed: 68 (3 UL)
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See detailIdentifiability of Finite Mixture Models with underlying Normal Distribution
Noel, Cédric; Schiltz, Jang UL

E-print/Working paper (2020)

In this paper, we show under which conditions generalized finite mixture with underlying normal distribution are identifiable in the sense that a given dataset leads to a uniquely determined set of model ... [more ▼]

In this paper, we show under which conditions generalized finite mixture with underlying normal distribution are identifiable in the sense that a given dataset leads to a uniquely determined set of model parameter estimations up to a permuta-tion of the clusters. [less ▲]

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See detailSouth Africa’s incomplete transition towards socio-economic justice: A case study on inequality and populism
Owiso, Owiso UL; Boshoff, Elsabé

E-print/Working paper (2020)

South Africa is currently one of the world’s most unequal countries, with massive income inequality, millions of people living in poverty without access to basic services and amenities, unemployment rates ... [more ▼]

South Africa is currently one of the world’s most unequal countries, with massive income inequality, millions of people living in poverty without access to basic services and amenities, unemployment rates consistently above 20% and the top 10% of the population receiving two thirds of the total income. Government economic policies on poverty reduction in the decades since the advent of democracy in South Africa in 1994 have been unable to eradicate the extreme racialised inequality which was the basis of the 342 years of colonialism and apartheid which were characterised by systematic dispossession and socio-economic marginalisation of South Africa’s majority Black population and the systematic privileging of the minority White population. While this history is not the primary focus of this paper, it nonetheless provides useful context. The paper’s primary focus is on the more recent normative and legal challenges of post-1994 South Africa that have resulted in further entrenching socio-economic inequality and contributing to the rise of populism. In this paper we argue that the dire living conditions of a large proportion of the population and disillusionment with the State’s ability to deliver on its promises in this regard, along with the poor implementation of social and economic rights have led to the development of a populist culture in South African politics. [less ▲]

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See detailProfit taxation and royalties: evidence from gold mines in Sub-Saharan Africa
Bertinelli, Luisito UL; Bourgain, Arnaud UL; Zanaj, Skerdilajda UL

E-print/Working paper (2019)

In this paper, we analyze theoretically and empirically the effects of tax changes on firms’ profits in extractive industries. In the theoretical part, we assume a country that levies a profit tax and a ... [more ▼]

In this paper, we analyze theoretically and empirically the effects of tax changes on firms’ profits in extractive industries. In the theoretical part, we assume a country that levies a profit tax and a royalty on the profits of extractive firms to maximize its tax revenues. The mining companies may reduce their taxable income by cost manipulation. By analyzing the optimal choice of the government and of the firms, we first establish the optimal tax policy and then we investigate the impact of the optimal fiscal policy on firms’ profits. In the empirical part of the paper, we estimate the effect of the profit tax and royalty on the extracting firms’ profit in African countries during the period spanning from 2007 to 2018. We use the Mining Intelligence database to constitute a panel of annual individual data from a database of 363 gold mines located in 21 Sub-Saharan countries. We obtain an inverse relationship between the tax rate change of the two tax instruments and the profit of the firms. [less ▲]

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See detailDer Arbeitsmarkt der Sozialen Arbeit 2018 = Le marché de l'emploi du secteur social en 2018
Flammang, Manou Laure UL; Böwen, Petra UL

E-print/Working paper (2019)

This newsletter describes the job market in the social work sector in Luxembourg in 2018. The data are derived from an ongoing research project by the "PraxisBüro" of the University of Luxembourg. The ... [more ▼]

This newsletter describes the job market in the social work sector in Luxembourg in 2018. The data are derived from an ongoing research project by the "PraxisBüro" of the University of Luxembourg. The newsletter presents a selection of statistics concerning for example the most sought after qualification levels, the distribution of practice fields, the distribution of job offers in public, municipal, private and non-governmental organisations and the documented gap between the demand of social workers with a Bachelor diploma and the number of Bachelor diplomas issued in Luxembourg. [less ▲]

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See detailThe dual volume of quasi-Fuchsian manifolds and the Weil-Petersson distance
Mazzoli, Filippo UL

E-print/Working paper (2019)

Making use of the dual Bonahon-Schläfli formula, we prove that the dual volume of the convex core of a quasi-Fuchsian manifold M is bounded by an explicit constant, depending only on the topology of M ... [more ▼]

Making use of the dual Bonahon-Schläfli formula, we prove that the dual volume of the convex core of a quasi-Fuchsian manifold M is bounded by an explicit constant, depending only on the topology of M, times the Weil-Petersson distance between the hyperbolic structures on the upper and lower boundary components of the convex core of M. [less ▲]

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See detailFuturistic Project Becoming a Reality: Self-Driving Cars in Luxembourg
Vukovich, Lilla UL; Vysotskaya, Volha UL

E-print/Working paper (2019)

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See detailWHY IS THE MARKET SKEWNESS-RETURN RELATIONSHIP NEGATIVE?
Lehnert, Thorsten UL

E-print/Working paper (2019)

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See detailInexact Block Coordinate Descent Algorithms for Nonsmooth Nonconvex Optimization
Yang, Yang UL; Pesavento, Marius; Luo, Zhi-Quan et al

E-print/Working paper (2019)

In this paper, we propose an inexact block coordinate descent algorithm for large-scale nonsmooth nonconvex optimization problems. At each iteration, a particular block variable is selected and updated by ... [more ▼]

In this paper, we propose an inexact block coordinate descent algorithm for large-scale nonsmooth nonconvex optimization problems. At each iteration, a particular block variable is selected and updated by solving the original optimization problem with respect to that block variable inexactly. More precisely, a local approximation of the original optimization problem is solved. The proposed algorithm has several attractive features, namely, i) high flexibility, as the approximation function only needs to be strictly convex and it does not have to be a global upper bound of the original function; ii) fast convergence, as the approximation function can be designed to exploit the problem structure at hand and the stepsize is calculated by the line search; iii) low complexity, as the approximation subproblems are much easier to solve and the line search scheme is carried out over a properly constructed differentiable function; iv) guaranteed convergence to a stationary point, even when the objective function does not have a Lipschitz continuous gradient. Interestingly, when the approximation subproblem is solved by a descent algorithm, convergence to a stationary point is still guaranteed even if the approximation subproblem is solved inexactly by terminating the descent algorithm after a finite number of iterations. These features make the proposed algorithm suitable for large-scale problems where the dimension exceeds the memory and/or the processing capability of the existing hardware. These features are also illustrated by several applications in signal processing and machine learning, for instance, network anomaly detection and phase retrieval. [less ▲]

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See detailTo be or not to be: How the Luxembourgish government is preparing for Brexit
Vysotskaya, Volha UL; Vukovich, Lilla UL; Bissinger, Jutta UL et al

E-print/Working paper (2019)

This article summarizes the potential impact of BREXIT on Luxembourg (as seen by April 2019).

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