References of "Scientific congresses, symposiums and conference proceedings"
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See detailComparison of boundary treatments in thermal Lattice Boltzmann simulations of moving particles in fluids
Rosemann, T; Kravets, B; Kruggel-Emden, H et al

in Particle Technology Series (2019, April 09)

Various numerical schemes have been developed in recent years to simulate particle-laden flows. The Lattice Boltzmann method (LBM) has emerged as an efficient tool for direct numerical simulations in ... [more ▼]

Various numerical schemes have been developed in recent years to simulate particle-laden flows. The Lattice Boltzmann method (LBM) has emerged as an efficient tool for direct numerical simulations in which the flow field around the particles can be fully resolved. In the thermal Lattice Boltzmann method not only the flow field but also the temperature field is calculated by using one distribution function for the fluid density and one for the fluid temperature. The treatment of curved solid-fluid boundaries is crucial for the simulation of particulate flows with this method. While several aspects of moving boundaries have been discussed in previous studies for the non-thermal LBM, it remains unknown to what extend these findings are transferable to the thermal LBM. In this work, we consider a 3D thermal LBM with a multiple-relaxation-time (MRT) collision operator and compare different techniques that can be applied to handle the moving boundary. There are three key aspects in the LBM that need to be considered at the boundary: the momentum exchange method calculating the drag force acting upon particles, the bounce-back scheme determining the bounce-back of density distribution functions at a boundary, and the refilling algorithm assigning a value to the unknown density distribution functions at lattice nodes uncovered by the particle. First, we demonstrate how the choice of the technique to address these problems in the flow field impacts the results for the temperature field in the thermal LBM. In a second step, we focus on the thermal side where similar techniques need to be applied. We compare different refilling strategies and bounce-back schemes for the temperature distribution functions and assess heat transfer calculation methods for the particle surface. The performance of these implementations is evaluated by comparing the simulation results in terms of accuracy and stability for a moving particle in a channel flow with a Galilean invariant reference system in which the particle’s position is fixed. We conduct this analysis for various Reynolds and Prandtl numbers to test the applicability of the individual techniques to varying flow conditions. Moreover, we demonstrate the potential of the implementation found to be superior by considering a more complex flow field in a particle packing. Our findings serve as a guideline for choosing suitable moving boundary treatments in thermal LBM simulations of particle-laden flows. [less ▲]

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See detailThe Influence of Professional Development on Early Years Teachers’ and Educators’ Attitudes and Practices in Luxembourg
Kirsch, Claudine UL

Scientific Conference (2019, April 09)

The present case-study based in multilingual Luxembourg reports on the influence of professional development on two preschool teachers’ attitudes towards multilingual education and their emerging ... [more ▼]

The present case-study based in multilingual Luxembourg reports on the influence of professional development on two preschool teachers’ attitudes towards multilingual education and their emerging multilingual practices. The need for multilingual pedagogies has been recognized and several countries in Europe have implemented multilingual programs in early childhood (García, Lin, & May, 2017; Panagiotopoulou, 2016). Nevertheless, practices often remain monolingual and focus on the development of the majority language (Kratzmann et al., 2017). In Luxembourg, new laws were voted in 2017 that require preschool teachers to develop the three-to-five -year-olds’ skills in Luxembourgish, familiarize them with French, and value home languages. Before 2017, the language policy focused on Luxembourgish. Nevertheless, some teachers had implemented multilingual practices to address the diverse language needs of the children (Kirsch, 2017). In 2015/16, 63,5 % of the four-year-olds did not speak Luxembourgish as a home language (MENJE, 2017). To develop inclusive multilingual practices, researchers at the University of Luxembourg developed a professional development program (thereafter PD) based on the pedagogy of translanguaging (García et al., 2017). The latter is supportive of social justice, places the learners at the centre and gives them some agency over their language use. The 30-hour program was collaborative and inquiry-based and included coaching. The practitioners were invited to implement activities based on books and rhymes in several languages and video-record these activities. The professionals reflected on their practices in the meetings. The research project drew on both qualitative and quantitative research methods. The data collection drew on a questionnaire completed before, during and after the PD; six interviews; six observations of the course and 15 video-recorded classroom activities; four coaching reports and emails after the coaching. The methods of data analysis include paired samples t-test, correlational analysis and content analysis (Braun & Clark, 2006). The findings show a positive effect of PD on the teachers’ knowledge about language learning and their attitudes towards multilingual education. At the beginning of the course, both teachers were influenced by the monolingual language policy in place, parental expectation, and the belief that children learn less Luxembourgish if they encountered other languages. The initial sceptics changed once the teachers began to implement activities in French and home languages, and realized the children’s motivation,engagement and continued progress in Luxembourgish. Both incorporated rituals and regular activities that drew on multiple languages. Both repeatedly acknowledged the impact of the PD, stating that the instruction, the reflection on their activities and the feedback helped them develop different perspectives on their own teaching. The findings of this study confirm that long-term, collaborative and inquiry-based professional development can be transformative (Gaikhorst et al., 2017; Kennedy, 2005; Prenger et al., 2017). They also contribute to the dearth of literature on PD on multilingual education in early years (Egert, 2015). [less ▲]

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See detailAn Effective Hybrid Imperialist Competitive Algorithm and Tabu Search for an Extended Flexible Job Shop Scheduling Problem
Tessaro Lunardi, Willian UL; Voos, Holger UL; Cherri, Luiz Henrique

in 34th ACM/SIGAPP Symposium On Applied Computing, Limassol, Cyprus April 8-12, 2019 (2019, April 08)

An extended version of the flexible job shop problem is tackled in this work. The investigated extension of the classical flexible job shop problem allows the precedences between the operations to be ... [more ▼]

An extended version of the flexible job shop problem is tackled in this work. The investigated extension of the classical flexible job shop problem allows the precedences between the operations to be given by an arbitrary directed acyclic graph instead of a linear order. The problem consists of designating the operations to the machines and sequencing them in compliance with the supplied precedences. The goal in the present work is the minimization of the makespan. In order to produce reasonable outcomes in acceptable time, a hybrid imperialist competitive algorithm and tabu search is proposed to solve the problem. Numerical experiments assess the efficiency of the proposed method and compare it with well-known scheduling algorithms. [less ▲]

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See detailEnergy Systemic Risk
Decet, Romain; Lehnert, Thorsten UL

Scientific Conference (2019, April 06)

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See detailConvergence, concurrence, harmonisation – une analyse comparative de la fiscalité Be-Ne-Lux (1945-1992)
Danescu, Elena UL

Scientific Conference (2019, April 04)

The paper aims to investigate the concept, context and socio-economic consequences of fiscal competition and fiscal justice, with a focus on the taxation of Beneux countries. The analysis is carried out ... [more ▼]

The paper aims to investigate the concept, context and socio-economic consequences of fiscal competition and fiscal justice, with a focus on the taxation of Beneux countries. The analysis is carried out at the intersection of several historical fields – national, regional, European and international –, and in a interdisciplinary approach. The research is based on a wide range of primary sources (original archives from Luxembourg, Belgium, the Netherlands, France, Germany and international organisations), by taking into account of a variety of institutions, players and mechanisms, and through the prism of the existing literature in the field. The findings emerged of this analysis may make a valuable addition to this historiography and provide new information, nuances and interpretations in the ongoing debates. [less ▲]

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See detailLaser beam joining of copper to aluminum sheet
Mathivanan, Karthik UL; Plapper, Peter UL

Poster (2019, April 04)

Dissimilar metal joining plays a very important role in the battery connections, especially copper and aluminum sheets. The existing literatures for laser research mostly focused on joining from the less ... [more ▼]

Dissimilar metal joining plays a very important role in the battery connections, especially copper and aluminum sheets. The existing literatures for laser research mostly focused on joining from the less reflective aluminum side to bond with copper. In the current research, we explore the joining process from copper side.Finally the optical emission of Cu-Al joint is presented with 394 nm peak as an indication to study the melting of Al. [less ▲]

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See detailSecurity – Visible, Yet Unseen? How Displaying Security Mechanisms Impacts User Experience and Perceived Security
Distler, Verena UL; Zollinger, Marie-Laure UL; Lallemand, Carine UL et al

in Proceedings of ACM CHI Conference on Human Factors in Computing Systems (CHI2019) (2019, April)

An unsolved debate in the field of usable security concerns whether security mechanisms should be visible, or blackboxed away from the user for the sake of usability. However, tying this question to ... [more ▼]

An unsolved debate in the field of usable security concerns whether security mechanisms should be visible, or blackboxed away from the user for the sake of usability. However, tying this question to pragmatic usability factors only might be simplistic. This study aims at researching the impact of displaying security mechanisms on user experience (UX) in the context of e-voting. Two versions of an e-voting application were designed and tested using a between-group experimental protocol (N=38). Version D displayed security mechanisms, while version ND did not reveal any security-related information. We collected data on UX using standardised evaluation scales and semi-structured interviews. Version D performed better overall in terms of UX and need fulfilment. Qualitative analysis of the interviews gives further insights into factors impacting perceived security. Our study adds to existing research suggesting a conceptual shift from usability to UX and discusses implications for designing and evaluating secure systems. [less ▲]

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See detailPricing Perspective for SWIPT in OFDM-based Multi-User Wireless Cooperative Systems
Gautam, Sumit UL; Lagunas, Eva UL; Vuppala, Satyanarayana UL et al

Scientific Conference (2019, April)

We propose a novel formulation for joint maximization of total weighted sum-spectral efficiency and weighted sum-harvested energy to study Simultaneous Wireless Information and Power Transfer (SWIPT) from ... [more ▼]

We propose a novel formulation for joint maximization of total weighted sum-spectral efficiency and weighted sum-harvested energy to study Simultaneous Wireless Information and Power Transfer (SWIPT) from a pricing perspective. Specifically, we consider that a transmit source communicates with multiple destinations using Orthogonal Frequency Division Multiplexing (OFDM) system within a dual-hop relay-assisted network, where the destination nodes are capable of jointly decoding information and harvesting energy from the same radio-frequency (RF) signal using either the time-switching (TS) or power-splitting (PS) based SWIPT receiver architectures. Computation of the optimal solution for the aforementioned problem is an extremely challenging task as joint optimization of several network resources introduce intractability at high numeric values of relays, destination nodes and OFDM sub-carriers. Therefore, we present a suitable algorithm with sub-optimal results and good performance to compute the performance of joint data processing and harvesting energy under fixed pricing methods by adjusting the respective weight factors, motivated by practical statistics. Furthermore, by exploiting the binary options of the weights, we show that the proposed formulation can be regulated purely as a sum-spectral efficiency maximization or solely as a sum-harvested energy maximization problem. Numerical results illustrate the benefits of the proposed design under several operating conditions and parameter values. [less ▲]

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See detailRobust Precoding Techniques for Multibeam Mobile Satellite Systems
Joroughi, Vahid UL; Shankar, Bhavani UL; Maleki, Sina UL et al

in 2019 IEEE Wireless Communications and Networking Conference (WCNC) (2019, April)

This paper presents designing precoding technique at the gateway of a multibeam mobile satellite systems, enabling full frequency reuse pattern among the beams. Such a system brings in two critical ... [more ▼]

This paper presents designing precoding technique at the gateway of a multibeam mobile satellite systems, enabling full frequency reuse pattern among the beams. Such a system brings in two critical challenges to overcome. The inter-beam interference makes applying interference mitigation techniques necessary. Further, when the user terminals are mobile the Channel State Information (CSI) becomes time-varying which is another challenge to overcome. Therefore, the gateway has only access to an outdated CSI, which can eventually limit the precoding gains. In this way, employing a proper CSI estimation mechanism at the gateway can improve the performance of the precoding scheme. In this context, the objectives of this paper are two folds. First, we present different CSI feedback mechanisms which aim at preserving a lower CSI variations at the gateway. Then, we develop the corresponding precoding schemes which are adapted with the proposed CSI feedback mechanisms. To keep the complexity of the proposed precoding schemes affordable, we consider a maritime communication scenario so that the signals received by mobile user terminals suffer from a lower pathloss compared to the Land Mobile communication. Finally, we provide several simulations results in order to evaluate the performance of the proposed precoding techniques. [less ▲]

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See detailMortgages and Life Time Contracts
Ratti, Luca UL

Scientific Conference (2019, April)

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See detailFog Computing as the Key for Seamless Connectivity Handover in Future Vehicular Networks
Palattella, Maria Rita UL; Soua, Ridha UL; Abdelmajid, Khelil et al

in The 34th ACM Symposium On Applied Computing (SAC (2019, April)

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See detailLooking into the Past: Evaluating the Effect of Time Gaps in a Personalized Sentiment Model
Guo, Siwen UL; Höhn, Sviatlana UL; Schommer, Christoph UL

in ACM/SIGAPP Symposium On Applied Computing, Limassol 8-12 April 2019 (2019, April)

This paper concerns personalized sentiment analysis, which aims at improving the prediction of the sentiment expressed in a piece of text by considering individualities. Mostly, this is done by relating ... [more ▼]

This paper concerns personalized sentiment analysis, which aims at improving the prediction of the sentiment expressed in a piece of text by considering individualities. Mostly, this is done by relating to a person’s past expressions (or opinions), however the time gaps between the messages are not considered in the existing works. We argue that the opinion at a specific time point is affected more by recent opinions that contain related content than the earlier or unrelated ones, thus a sentiment model ought to include such information in the analysis. By using a recurrent neural network with an attention layer as a basic model, we introduce three cases to integrate time gaps in the model. Evaluated on Twitter data with frequent users, we have found that the performance is improved the most by including the time information in the Hawkes process, and it is also more effective to add the time information in the attention layer than at the input. [less ▲]

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See detailStability Analysis of Power Networks under Cyber-Physical Attacks: an LPV-Descriptor Approach
Bezzaoucha, Souad UL; Voos, Holger UL

in Bezzaoucha, Souad (Ed.) International Conference on Control, Decision and Information Technologies (2019, April)

This paper proposes a unified and advanced framework for the modeling, stability study and stabilization of a Power Networks subject to an omniscient adversary (i.e. cyber-attack). From the system model ... [more ▼]

This paper proposes a unified and advanced framework for the modeling, stability study and stabilization of a Power Networks subject to an omniscient adversary (i.e. cyber-attack). From the system model developed in [24], based on the well-known sector non-linearity approach and the convex polytopic transformation, the attacked system (descriptor model) is re-written in a more convenient form (Linear Parameter Varying-LPV) with unmeasurable premise variables. The so-called Lyapunov-based methods are applied in order to study the stability and security problems despite the presence of cyber-attacks. The conditions will be given in terms of Linear- Bilinear Matrix Inequality LMI- BMI constraints. [less ▲]

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See detailTime Series Modeling of Market Price in Real-Time Bidding
Du, Manxing UL; Hammerschmidt, Christian UL; Varisteas, Georgios UL et al

in 27th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (2019, April)

Real-Time-Bidding (RTB) is one of the most popular online advertisement selling mechanisms. Modeling the highly dynamic bidding environment is crucial for making good bids. Market prices of auctions ... [more ▼]

Real-Time-Bidding (RTB) is one of the most popular online advertisement selling mechanisms. Modeling the highly dynamic bidding environment is crucial for making good bids. Market prices of auctions fluctuate heavily within short time spans. State-of-the-art methods neglect the temporal dependencies of bidders’ behaviors. In this paper, the bid requests are aggregated by time and the mean market price per aggregated segment is modeled as a time series. We show that the Long Short Term Memory (LSTM) neural network outperforms the state-of-the-art univariate time series models by capturing the nonlinear temporal dependencies in the market price. We further improve the predicting performance by adding a summary of exogenous features from bid requests. [less ▲]

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See detailResearch visit, Chulalongkorn University, Bangkok, Thailand
Wolff, Christian UL

Scientific Conference (2019, April)

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See detailExploration of Different School Value-Added Models in a Highly Heterogeneous Educational Context
Levy, Jessica UL; Brunner, Martin; Keller, Ulrich UL et al

Scientific Conference (2019, April)

Detailed reference viewed: 88 (14 UL)
See detailComputational Metaphysics: New Insights on Gödel's Ontological Argument and Modal Collapse
Benzmüller, Christoph UL

in Kovac, Srecko; Swietorzecka, Kordula (Eds.) Formal Methods and Science in Philosophy III, Informal Proceedings (2019, April)

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See detailTopic-based Historical Information Selection for Personalized Sentiment Analysis
Guo, Siwen UL; Höhn, Sviatlana UL; Schommer, Christoph UL

in European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning, Bruges 24-26 April 2019 (2019, April)

In this paper, we present a selection approach designed for personalized sentiment analysis with the aim of extracting related information from a user's history. Analyzing a person's past is key to ... [more ▼]

In this paper, we present a selection approach designed for personalized sentiment analysis with the aim of extracting related information from a user's history. Analyzing a person's past is key to modeling individuality and understanding the current state of the person. We consider a user's expressions in the past as historical information, and target posts from social platforms for which Twitter texts are chosen as exemplary. While implementing the personalized model PERSEUS, we observed information loss due to the lack of flexibility regarding the design of the input sequence. To compensate this issue, we provide a procedure for information selection based on the similarities in the topics of a user's historical posts. Evaluation is conducted comparing different similarity measures, and improvements are seen with the proposed method. [less ▲]

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See detailMicrofluidic Wet Spinning of Core-Sheath Elastomer-Liquid Crystal Fibers
Honaker, Lawrence William UL; Vats, Shameek UL; Anyfantakis, Emmanouil UL et al

Scientific Conference (2019, March 29)

Liquid crystals encapsulated in fibers have a wide variety of applications in sensing. In order to produce these, several methods have been explored. Electrospinning is among the better-known techniques ... [more ▼]

Liquid crystals encapsulated in fibers have a wide variety of applications in sensing. In order to produce these, several methods have been explored. Electrospinning is among the better-known techniques with considerable successes. Only a limited range of polymers, though, has been used for electrospinning with liquid crystal cores, and the process of electrospinning has many obstacles to its utility at an industrial scale. On the other hand, wet-spinning techniques are better suited for industrial applications and are widely used in textile manufacturing, but are not commonly used for coaxial fiber production, especially with the large experimental scales that are difficult to replicate in a standard liquid crystal research laboratory. We therefore propose a method for wet-spinning coaxial core-sheath liquid crystal-filled elastomer fibers using a microfluidic set-up. Based on the flow-focusing method used for the production of liquid crystal shells and emulsions, this technique generates coaxial filaments by pumping a core-sheath flow of a liquid crystal surrounded by a rubbery polymer solution into a co-flowing coagulation bath. The coagulation bath is tuned to quickly extract the elastic polymer solution solvent, leaving behind a dry, continuous fiber. We have employed this method to produce fibers of polybutadiene and polyisoprene containing a core of a liquid crystal, such as 4-cyano-4'-pentylbiphenyl (5CB). Investigations into the choice of polymer solution, i.e. both the polymer and solvents used, will be presented in addition to discussion on parameters affecting the contiguity of the core. [less ▲]

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See detailN point Virasoro algebras are multi-point Krichever Novikov type algebras
Schlichenmaier, Martin UL

Scientific Conference (2019, March 19)

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See detailHigher-Order DCA against Standard Side-Channel Countermeasures
Bogdanov, Andrey; Rivain, Matthieu; Philip, S. Vejre et al

in Polian, Ilia; Stöttinger, Marc (Eds.) Constructive Side-Channel Analysis and Secure Design (2019, March 16)

At CHES 2016, Bos et al. introduced differential computational analysis (DCA) as an attack on white-box software implementations of block ciphers. This attack builds on the same principles as DPA in the ... [more ▼]

At CHES 2016, Bos et al. introduced differential computational analysis (DCA) as an attack on white-box software implementations of block ciphers. This attack builds on the same principles as DPA in the classical side-channel context, but uses computational traces consisting of plain values computed by the implementation during execution. It was shown to be able to recover the key of many existing AES white-box implementations. The DCA adversary is passive, and so does not exploit the full power of the white-box setting, implying that many white-box schemes are insecure even in a weaker setting than the one they were designed for. It is therefore important to develop implementations which are resistant to this attack. We investigate the approach of applying standard side-channel countermeasures such as masking and shuffling. Under some necessary conditions on the underlying randomness generation, we show that these countermeasures provide resistance to standard (first-order) DCA. Furthermore, we introduce higher-order DCA, along with an enhanced multivariate version, and analyze the security of the countermeasures against these attacks. We derive analytic expressions for the complexity of the attacks – backed up through extensive attack experiments – enabling a designer to quantify the security level of a masked and shuffled implementation in the (higher-order) DCA setting. [less ▲]

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See detailModelling how the relative spatial pattern of green within cities impact carbon flows
Boura, Marlène Delphine Fabienne UL

Scientific Conference (2019, March 14)

Cities - particularly the denser ones - are often depicted as sustainable systems that reduce the consumption of land and optimize energy use for buildings and transport. Cities, however - exactly because ... [more ▼]

Cities - particularly the denser ones - are often depicted as sustainable systems that reduce the consumption of land and optimize energy use for buildings and transport. Cities, however - exactly because they concentrate human activities - constitute the main source of CO2 emissions into the atmosphere. Yet it is important to assess to what extent they can cope with their own emissions. We address this issue by examining how the internal spatial organization of cities can impact the flow of anthropogenic CO2 between their major sources - human activities, mainly on built-up lands - ; and their main storage infrastructures, with a focus here on urban green spaces and forests. Is it better to have a dense core with a peripheric green belt? Large green patches within the core centre? Or small and fragmented green spaces? The objective of the present work is to tests whether the internal spatial organization of cities - in terms of green infrastructure characteristics and land use types - matters for evaluating carbon sequestration potentials of cities. Or whether these cities can simply be considered as single objects with a quantity of carbon emissions and a carbon sink capacity derived directly from aggregated land use data. We model urban carbon flows for about 800 Functional Urban Areas (FUAs) of European cities using the Urban Atlas 2012 database. The model intends to characterize the emissions, their diffusion and sequestration within the urban regions as well as their exit from the analysed urban systems. The FUAs are classified along landscape metrics in order to derive a typology of urban forms focusing on the relative position of green and human activities and their characteristics. The analysis then investigates how the type of urban form can affect the level of efficiency of CO2 uptake. The efficiency is defined as the share of local emissions captured within the urban boundaries. The model will be validated using eddy covariance empirical data. [less ▲]

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See detailMaking an Archive-Based Historical Web Documentary
Santana, Dominique UL

Scientific Conference (2019, March 14)

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See detailUnderstanding Alpha Decay
Penasse, Julien UL

Scientific Conference (2019, March 12)

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See detailCombining Deep Gaussian Process and Rule-Based Method for Decision-Making in Self-Driving Simulation with Small Data
Fang, W.; Li, H.; Dang, S. et al

in 2019 15th International Conference on Computational Intelligence and Security (CIS) (2019, March 05)

Self-driving vehicle is a popular and promising field in artificial intelligence. Conventional architecture consists of multiple sensors, which work collaboratively to sense the units on road to yield a ... [more ▼]

Self-driving vehicle is a popular and promising field in artificial intelligence. Conventional architecture consists of multiple sensors, which work collaboratively to sense the units on road to yield a precise and safe driving strategy. Besides the precision and safety, the quickness of decision is also a major concern. In order to react quickly, the vehicle need to predict its next possible action, such as acceleration, brake and steering angle, according to its latest few actions and status. In this paper, we treat this decision-making problem as a regression problem and use deep gaussian process to predict its next action. The regression model is trained using simulation data sets and accurately captures the most significant features. Combined with rule-based method, it can be used in Torcs simulation engine to realize successful loop trip on virtual roads. The proposed method outperforms the existing reinforcement learning methods on the performance indicators of time consumption and the size of data volume. It may be useful for real road tests in the future. [less ▲]

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See detailCharacterizations and classifications of quasitrivial semigroups
Devillet, Jimmy UL; Marichal, Jean-Luc UL; Teheux, Bruno UL

Scientific Conference (2019, March 03)

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See detailRobust Encryption, Extended
Geraud, Remi; Naccache, David; Rosie, Razvan UL

in Matsui, Mitsuru (Ed.) The Cryptographers' Track at the RSA Conference 2019, San Francisco, CA, USA, March 4–8, 2019, Proceedings (2019, March 01)

Robustness is a notion often tacitly assumed while working with encrypted data. Roughly speaking, it states that a ciphertext cannot be decrypted under different keys. Initially formalized in a public-key ... [more ▼]

Robustness is a notion often tacitly assumed while working with encrypted data. Roughly speaking, it states that a ciphertext cannot be decrypted under different keys. Initially formalized in a public-key context, it has been further extended to key-encapsulation mechanisms, and more recently to pseudorandom functions, message authentication codes and authenticated encryption. In this work, we motivate the importance of establishing similar guarantees for functional encryption schemes, even under adversarially generated keys. Our main security notion is intended to capture the scenario where a ciphertext obtained under a master key (corresponding to Authority 1) is decrypted by functional keys issued under a different master key (Authority 2). Furthermore, we show there exist simple functional encryption schemes where robustness under adversarial key-generation is not achieved. As a secondary and independent result, we formalize robustness for digital signatures – a signature should not verify under multiple keys – and point out that certain signature schemes are not robust when the keys are adversarially generated. We present simple, generic transforms that turn a scheme into a robust one, while maintaining the original scheme’s security. For the case of public-key functional encryption, we look into ciphertext anonymity and provide a transform achieving it. [less ▲]

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See detailEvaluation of End-To-End Learning for Autonomous Driving: The Good, the Bad and the Ugly
Varisteas, Georgios UL; Frank, Raphaël UL; Sajadi Alamdari, Seyed Amin UL et al

in 2nd International Conference on Intelligent Autonomous Systems, Singapore, Feb. 28 to Mar. 2, 2019 (2019, March 01)

Detailed reference viewed: 258 (47 UL)
See detailThe role of executive functions in task-related analgesia
Rischer, Katharina Miriam UL; Gigl, Sandra; Dierolf, Angelika UL et al

Poster (2019, March)

Introduction: Recent research suggests that weaker executive functions may be linked to a higher risk of pain chronicity. However, little is known about how executive functions affect the modulation of ... [more ▼]

Introduction: Recent research suggests that weaker executive functions may be linked to a higher risk of pain chronicity. However, little is known about how executive functions affect the modulation of acute pain. The present study aimed to investigate the impact of inhibitory control on the success of cognitive distraction from pain. Methods: Participants completed a battery of cognitive tasks (Go/NoGo, Color Stroop, Eriksen Flanker), assessing their cognitive inhibition and selective attention abilities. Additionally, self-report measures of pain catastrophizing and fear of pain were administered. In a pain distraction paradigm, participants completed either a cognitively demanding working memory task (2-back task) or a visually matched easy control task (target response task) while receiving warm or painful thermal stimuli to their left forearm. Nociceptive stimulus intensity was individually calibrated for each participant. Moreover, to maintain a similar level of task difficulty across participants, task speed was continuously adapted based on the participant's performance in the previous trials. Following each trial, participants rated the perceived intensity and unpleasantness of the thermal stimuli on visual analogue scales. Results: As expected, preliminary results indicate that the 2-back task, but not the target response task, successfully distracted participants from thermal pain, manifesting in significantly lower intensity and unpleasantness ratings. Importantly, the magnitude of the distraction effect was negatively associated with the Flanker effect. Discussion: In line with previous research, engaging in a cognitively demanding task led to significantly lower pain intensity and unpleasantness ratings when compared to an easy control task. Moreover, results indicate that better interference control abilities may predict greater task-related analgesia. Taken together, the results of the present study suggest that it is crucial to assess executive functions to develop a better understanding of the mechanisms behind cognitive distraction from pain. [less ▲]

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See detailTrue or False Contradictions between Life Time Contracts and Platform Work Contracts?
Ratti, Luca UL

Scientific Conference (2019, March)

Detailed reference viewed: 47 (2 UL)
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See detailSocial Rehire Clauses and Transfer of Undertakings
Ratti, Luca UL

Scientific Conference (2019, March)

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See detailA Hybrid Machine Learning and Schedulability Method for the Verification of TSN Networks
Mai, Tieu Long UL; Navet, Nicolas UL; Migge, Jörn

in 15th IEEE International Workshop on Factory Communication Systems (WFCS2019) (2019, March)

Machine learning (ML), and supervised learning in particular, can be used to learn what makes it hard for a network to be feasible and try to predict whether a network configuration will be feasible ... [more ▼]

Machine learning (ML), and supervised learning in particular, can be used to learn what makes it hard for a network to be feasible and try to predict whether a network configuration will be feasible without executing a conventional schedulability analysis. A disadvantage of ML-based timing verification with respect to schedulability analysis is the possibility of "false positives": configurations deemed feasible while they are not. In this work, in order to minimize the rate of false positives, we propose the use of a measure of the uncertainty of the prediction to drop it when the uncertainty is too high, and rely instead on schedulability analysis. In this hybrid verification strategy, the clear-cut decisions are taken by ML, while the more difficult ones are taken by a conventional schedulability analysis. Importantly, the trade-off achieved between prediction accuracy and computing time can be controlled. We apply this hybrid verification method to Ethernet TSN networks and obtain, for instance in the case of priority scheduling with 8 traffic classes, a 99% prediction accuracy with a speedup factor of 5.7 with respect to conventional schedulability analysis and a reduction of 46% of the false positives compared to ML alone. [less ▲]

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See detailThe Pact with the Devil as Model and Crisis of Complicity (Marlowe, Goethe)
Kohns, Oliver UL

Scientific Conference (2019, March)

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See detailIntergenerational mobility in Europe: Home ownership as a facet of social reproduction?
Chauvel, Louis UL; Hartung, Anne UL

Scientific Conference (2019, March)

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See detailOrganiser, European Banking Center (EBC) Network Conference
Wolff, Christian UL

Scientific Conference (2019, March)

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See detailArt in Rich-Prospect: Evaluating Next-Generation User Interfaces for Cultural Heritage
Morse, Christopher UL; Koenig, Vincent UL; Lallemand, Carine UL et al

in Morse, Christopher; Koenig, Vincent; Lallemand, Carine (Eds.) et al MW2019: Museums and the Web, Boston 2-6 April 2019 (2019, March)

The present study reports on the user experience (UX) of rich-prospect browsing, an emerging interface design trend for digital cultural heritage. Building on research that suggests online museum ... [more ▼]

The present study reports on the user experience (UX) of rich-prospect browsing, an emerging interface design trend for digital cultural heritage. Building on research that suggests online museum collections are used only infrequently by the general public, this study investigates the role of next-generation user interfaces in the design of optimal browsing experiences. Moreover, it describes the results of user testing for three different arts and culture collections that make use of rich-prospect. The study recruited 30 participants of varying ages, nationalities, and museum visiting habits to discuss their museum experiences and test three different applications: Coins, Curator Table, and Museum of the World. The results of the study provide insights into the user experience of a new browsing medium and reveal the information-seeking habits and patterns that occurred within these information environments. Moreover, the study isolated the core features of rich-prospect in order to define opportunities and pain points during the browsing experience and indicated which features in particular are most important to people during the browsing experience. Finally, we suggest some best practices going forward in the design of rich-prospect. [less ▲]

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See detailTranslingual Discursive Spaces in Language and Arts Lessons
Degano, Sarah UL

in Literacy Information and Computer Education Journal (2019, March), 10(1), 3094-3102

Flexible multilingual pedagogies such as translanguaging pedagogies are promising stepping stones towards a more equitable access to educational resources for students of different backgrounds. Recent ... [more ▼]

Flexible multilingual pedagogies such as translanguaging pedagogies are promising stepping stones towards a more equitable access to educational resources for students of different backgrounds. Recent research in Luxembourgish preschool, Year 1 and Year 2 classes, show that teachers have begun to implement such pedagogies by encouraging the deployment of the students’ full linguistic repertoires, including their home languages. Little attention has however been paid to the later years of primary school where the achievement gap between students with and without a migration background is particularly high. The present qualitative longitudinal study focusses on students in Years 4 and 5 and examines to what extent they deploy their linguistic repertoires in interaction with their peers. Drawing on observations, recordings and interviews, this paper explores the language use of two Portuguese-speaking 4th graders in Language and Arts lessons. Findings show that the students mobilize their linguistic and cultural resources to different extents and, hereby, open or close translingual discursive spaces for further exchange. The findings should contribute to the understanding of multilingual students’ language practices and provide insight into how their linguistic and cultural resources can be capitalized on. [less ▲]

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See detailStudents with emotional and behavioral problems: Their emotional experience in the classroom during peer interactions
Zurbriggen, Carmen UL; Knickenberg, Margarita; Venetz, Martin

Scientific Conference (2019, March)

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See detailTransforming Collaboration Data into Network Layers for Enhanced Analytics
Esmaeilzadeh Dilmaghani, Saharnaz UL; Piyatumrong, Apivadee; Bouvry, Pascal UL et al

Scientific Conference (2019, February 25)

We consider the problem of automatically generating networks from data of collaborating researchers. The objective is to apply network analysis on the resulting network layers to reveal supplemental ... [more ▼]

We consider the problem of automatically generating networks from data of collaborating researchers. The objective is to apply network analysis on the resulting network layers to reveal supplemental patterns and insights of the research collaborations. In this paper, we describe our data-to-networks method, which automatically generates a set of logical network layers from the relational input data using a linkage threshold. We, then, use a series of network metrics to analyze the impact of the linkage threshold on the individual network layers. Moreover, results from the network analysis also provide beneficial information to improve the network visualization. We demonstrate the feasibility and impact of our approach using real-world collaboration data. We discuss how the produced network layers can reveal insights and patterns to direct the data analytics more intelligently. [less ▲]

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See detailAVATAR: Fixing Semantic Bugs with Fix Patterns of Static Analysis Violations
Liu, Kui UL; Koyuncu, Anil UL; Dongsun, Kim et al

in The 26th IEEE International Conference on Software Analysis, Evolution, and Reengineering (SANER-2019) (2019, February 24)

Fix pattern-based patch generation is a promising direction in Automated Program Repair (APR). Notably, it has been demonstrated to produce more acceptable and correct patches than the patches obtained ... [more ▼]

Fix pattern-based patch generation is a promising direction in Automated Program Repair (APR). Notably, it has been demonstrated to produce more acceptable and correct patches than the patches obtained with mutation operators through genetic programming. The performance of pattern-based APR systems, however, depends on the fix ingredients mined from fix changes in development histories. Unfortunately, collecting a reliable set of bug fixes in repositories can be challenging. In this paper, we propose to investigate the possibility in an APR scenario of leveraging code changes that address violations by static bug detection tools. To that end, we build the AVATAR APR system, which exploits fix patterns of static analysis violations as ingredients for patch generation. Evaluated on the Defects4J benchmark, we show that, assuming a perfect localization of faults, AVATAR can generate correct patches to fix 34/39 bugs. We further find that AVATAR yields performance metrics that are comparable to that of the closely-related approaches in the literature. While AVATAR outperforms many of the state-of-the-art pattern-based APR systems, it is mostly complementary to current approaches. Overall, our study highlights the relevance of static bug finding tools as indirect contributors of fix ingredients for addressing code defects identified with functional test cases. [less ▲]

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See detailShould You Consider Adware as Malware in Your Study?
Gao, Jun UL; Li, Li; Kong, Pingfan UL et al

in 26th edition of the IEEE International Conference on Software Analysis, Evolution and Reengineering (2019, February 24)

Empirical validations of research approaches eventually require a curated ground truth. In studies related to Android malware, such a ground truth is built by leveraging Anti-Virus (AV) scanning reports ... [more ▼]

Empirical validations of research approaches eventually require a curated ground truth. In studies related to Android malware, such a ground truth is built by leveraging Anti-Virus (AV) scanning reports which are often provided free through online services such as VirusTotal. Unfortunately, these reports do not offer precise information for appropriately and uniquely assigning classes to samples in app datasets: AV engines indeed do not have a consensus on specifying information in labels. Furthermore, labels often mix information related to families, types, etc. In particular, the notion of “adware” is currently blurry when it comes to maliciousness. There is thus a need to thoroughly investigate cases where adware samples can actually be associated with malware (e.g., because they are tagged as adware but could be considered as malware as well). In this work, we present a large-scale analytical study of Android adware samples to quantify to what extent “adware should be considered as malware”. Our analysis is based on the Androzoo repository of 5 million apps with associated AV labels and leverages a state-of-the-art label harmonization tool to infer the malicious type of apps before confronting it against the ad families that each adware app is associated with. We found that all adware families include samples that are actually known to implement specific malicious behavior types. Up to 50% of samples in an ad family could be flagged as malicious. Overall the study demonstrates that adware is not necessarily benign. [less ▲]

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See detailRobust Design of Power Minimizing Symbol-Level Precoder under Channel Uncertainty
Haqiqatnejad, Alireza UL; Kayhan, Farbod UL; Ottersten, Björn UL

in IEEE Global Communications Conference (GLOBECOM), Abu Dhabi 9-13 December 2018 (2019, February 21)

In this paper, we investigate the downlink transmission of a multiuser multiple-input single-output (MISO) channel under a symbol-level precoding (SLP) scheme, having imperfect channel knowledge at the ... [more ▼]

In this paper, we investigate the downlink transmission of a multiuser multiple-input single-output (MISO) channel under a symbol-level precoding (SLP) scheme, having imperfect channel knowledge at the transmitter. In defining the SLP design problem, a general category of constructive interference regions (CIR) called distance preserving CIR (DPCIR) is adopted. In particular, we are interested in a robust SLP design minimizing the total transmit power subject to individual quality-of-service (QoS) requirements. We consider two common models for the channel uncertainty region, namely, spherical (norm-bounded) and stochastic. For the spherical uncertainty model, a worst-case robust precoder is proposed, while for the stochastically known uncertainties, we derive a convex optimization problem with probabilistic constraints. We simulate the performance of the proposed robust approaches, and compare them with the existing methods. Through the simulation results, we also show that there is an essential trade-off between the two robust approaches. [less ▲]

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See detailThe real problem with Rawlsian reasonableness
Burks, Deven UL

Scientific Conference (2019, February 16)

Rawlsian “reasonableness” has been the object of considerable and varied criticism. Reactions range from its being “loaded” (Stout 2004: 184) or “chimerical” (Young 2005: 308) to “entirely circular” ... [more ▼]

Rawlsian “reasonableness” has been the object of considerable and varied criticism. Reactions range from its being “loaded” (Stout 2004: 184) or “chimerical” (Young 2005: 308) to “entirely circular” (Mulhall and Swift 2003: 483). Yet more critical reactions often employ external standards or equivocal senses of reasonableness to their detriment (Freeman 2004: 2045, 2063-5) or marshal apparently conflicting materials from Rawls’s broader theory (Young 2005, 2006). In this paper, I put forward a narrow, immanent criticism whereon the two basic aspects of reasonableness are shown to be in tension: the “burdens of judgment” may give the person reason to disagree over the need to propose and to abide by a common basis of fair terms of cooperation. My aims in doing so are threefold. First, I try to make sense of and set on firmer ground Stout’s (2004) critique of reasonableness as being epistemologically untenable. My second and third aims stem from the first. The second consists in carving out a middling conceptual space wherein the negation of Rawlsian “reasonableness” is not merely “unreasonable” in the sense of being willing to impose one’s comprehensive doctrine on others as the terms of political justification and coercion (Rawls 1996: 60-1; Freeman 2004: 2049) nor “unreasonable” in the sense of persons’ culpably endorsing a doctrine inconsistent with acceptance of the burdens of judgment (Rawls 2001: 184, 190; Freeman 2004: 2064) but, instead, “reasonably unreasonable” in the sense of the person’s nonculpably or justifiably rejecting the requirement to offer and to abide by fair terms of cooperation in view of the burdens of judgment. Third, I attempt to salvage a minimal core of reasonableness from the two-conjunct Rawlsian reasonableness, a core which contemporary political philosophers are hard-pressed to do without: the second conjunct consisting in the person’s acknowledgement of the burdens of judgment (Rawls 1996: 54-8). To that end, I proceed in two steps. First, I shall recall the two aspects of reasonableness and hold that their conjunction is necessary for a person to qualify as “reasonable”. In particular, this involves showing that a biconditional obtains: a person is reasonable if and only if the two basic aspects of reasonableness obtain, i.e. if and only if she is willing to propose fair terms of cooperation and she is willing to recognize the burdens of judgment. I also briefly define the site wherefrom one checks a person’s reasonableness: the “you and me” standpoint (Rawls 1996: 28). Secondly, I shall examine whether any burden gives reason to doubt the need to propose and to abide by a common basis of fair terms of cooperation. I find that each of the burdens, in its own way, leaves room to doubt whether reasonable persons in a well-ordered society would assent to such a need. For the first burden (complexity of evidence), the evidence backing the requirement of shared terms of cooperation defined ex ante is not obviously less complex than that contained in reasonable comprehensive doctrines. Regarding the second (relative weight of reasons), even supposing agreement on which reasons are relevant to deciding questions of justice, there may be still be disagreement over the relative priority of those reasons in deciding a given question. As to the third (conceptual indeterminacy and hard cases), such concepts as justice and fairness, cooperation and equality are all subject to the difficulties of identifying hard cases and probing a concept’s limits. Of the fourth (divergent total life experience), it is clear that, through her life experience, a person acquires a set of beliefs (political, moral, epistemological, religious, etc.) which could give the person reason to doubt or otherwise reject the first basic aspect of reasonableness, especially given its significant complexity. Finally, for the fifth burden (conflicting distinct normative considerations), persons may disagree over whether the first basic aspect in fact realizes these different considerations, the priority ordering to be fixed for such considerations and whether a common currency might be found so as to make such considerations commensurable, any of which may suffice for persons to be unable to reach agreement on the requirement, not simply on the reasons why it holds, but also on whether it holds at all. In reaching these findings, I parallel Clarke’s (1999: 639-41) claim that the burdens of judgment apply both to contractarianism’s “reasonable rejection procedure” and principles but do so from narrower, immanent grounds rather than the stronger claim that Rawls’s approach must be committed to substantive epistemological positions. This analysis yields two striking conclusions: First, public reason – the demand to present others with reasons which the person could reasonably expect them to accept – becomes looser and shifts to the domain of politics where one sees what public reasons others may in fact accept (Laden 2001). Seen from a different angle, one need not accept the idea that the first basic aspect and, hence, Rawlsian reasonableness are necessary conditions of political justification under conditions of reasonable pluralism (contra Krasnoff 2014: 696-7): rejecting this aspect and reasonableness in no way means that there can be no political justification under conditions of (reasonable) pluralism. Second, when conceiving justification and discourse, Rawls may be committed, despite himself, to accepting “reasonableness pluralism”, i.e. the view that there exist distinct, possibly irreconcilable accounts of reasonableness to which one may appeal when conceiving justification and discourse. Their combination may lead to a public reason liberalism framework which is at once looser and more actionable. [less ▲]

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See detailFunctional Interpretation of Single Amino Acid Substitutions in 1,330 Disease-Associated Genes
Iqbal, Sumaiya; Jespersen, Jakob Berg; Perez-Palma, Eduardo et al

in Biophysical Journal (2019, February 15), 116(3), 420-421

Elucidating molecular consequences of amino-acid-altering missense variants at scale is challenging. In this work, we explored whether features derived from three-dimensional (3D) protein structures can ... [more ▼]

Elucidating molecular consequences of amino-acid-altering missense variants at scale is challenging. In this work, we explored whether features derived from three-dimensional (3D) protein structures can characterize patient missense variants across different protein classes with similar molecular level activities. The identified disease-associated features can advance our understanding of how a single amino acid substitution can lead to the etiology of monogenic disorders. For 1,330 disease-associated genes (>80%, 1,077/1,330 implicated in Mendelian disorders), we collected missense variants from the general population (gnomAD database, N=164,915) and patients (ClinVar and HGMD databases, N=32,923). We in silico mapped the variant positions onto >14k human protein 3D structures. We annotated the protein positions of variants with 40 structural, physiochemical, and functional features. We then grouped the genes into 24 protein classes based on their molecular functions and performed statistical association analyses with the features of population and patient variants. We identified 18 (out of 40) features that are associated with patient variants in general. Specifically, patient variants are less exposed to solvent (p<1.0e-100), enriched on b-sheets (p<2.37e-39), frequently mutate aromatic residues (p<1.0e-100), occur in ligand binding sites (p<1.0e-100) and are spatially close to phosphorylation sites (p<1.0e-100). We also observed differential protein-class-specific features. For three protein classes (signaling molecules, proteases and hydrolases), patient variants significantly perturb the disulfide bonds (p<1.0e-100). Only in immunity proteins, patient variants are enriched in flexible coils (p<1.65e-06). Kinases and cell junction proteins exhibit enrichment of patient variants around SUMOylation (p<1.0e-100) and methylation sites (p<9.29e-11), respectively. In summary, we studied shared and unique features associated with patient variants on protein structure across 24 protein classes, providing novel mechanistic insights. We generated an online resource that contains amino-acid-wise feature annotation-track for 1,330 genes, summarizes the patient-variant-associated features on residue level, and can guide variant interpretation. [less ▲]

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See detailCharacterizations of idempotent n-ary uninorms
Devillet, Jimmy UL; Kiss, Gergely; Marichal, Jean-Luc UL

in 38th Linz Seminar on Fuzzy Set Theory (2019, February 05)

In this paper we provide a characterization of the class of idempotent n-ary uninorms on a given chain. When the chain is finite, we also provide anaxiomatic characterization of the latter class by means ... [more ▼]

In this paper we provide a characterization of the class of idempotent n-ary uninorms on a given chain. When the chain is finite, we also provide anaxiomatic characterization of the latter class by means of four conditions only: associativity, quasitriviality, symmetry, and nondecreasing monotonicity. In particular, we show that associativity can be replaced with bisymmetry in this axiomatization. [less ▲]

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See detailDer "March for Science" – eine Initiative für die Freiheit der Wissenschaft
Baudson, Tanja Gabriele UL

Scientific Conference (2019, February 01)

Der ›March for Science‹ ist eine international angelegte Großdemonstration, die sich für Wissenschaftsfreiheit und gegen ›alternative Fakten‹ ausspricht. Sie findet seit 2017 in mehr als 600 Städten ... [more ▼]

Der ›March for Science‹ ist eine international angelegte Großdemonstration, die sich für Wissenschaftsfreiheit und gegen ›alternative Fakten‹ ausspricht. Sie findet seit 2017 in mehr als 600 Städten weltweit statt. Im Rahmen eines Symposiums soll es um diese Initiative und das Thema ›Wissenschaft im politischen Meinungsstreit‹ gehen. [less ▲]

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See detailDismountable Flooring Systems for Multiple Use
Odenbreit, Christoph UL; Kozma, Andras UL

in IOP Conference Series: Earth and Environmental Science (2019, February), 225

Steel shapes our modern world as an integral part of the global construction economy. In the last decades, the sustainability of steel grew and turned from a linear to a circular business, where the ... [more ▼]

Steel shapes our modern world as an integral part of the global construction economy. In the last decades, the sustainability of steel grew and turned from a linear to a circular business, where the material is fully recovered and recycled after use. The RFCS Research Project “REDUCE” of the European Commission goes one step beyond the mere material recycling and investigates, how the circular economy’s philosophy can be used to reduce the carbon footprint furthermore. On that basis, one target of the research was to develop basic modular and standardised structural load bearing elements which can be adapted in the building or assembled, properly disassembled and partly or entirely be reused again in a subsequent building. This paper presents the respective research results of demountable flooring- and beam systems: 15 large scale push-out tests and two large scale composite beam tests as well as numerous finite element simulations with ABAQUS have been performed at the Laboratory of the ArcelorMittal Chair of Steel and Façade Engineering. The suitability for dis- and re-assembly as well as the strength, stiffness, slip capacity and ductility have been determined. The investigated systems included pre-stressed and epoxy injected systems, as well as solid slabs and composite slabs with profiled decking. The results showed sometimes higher resistances and smaller displacement capacities than conventional systems. The numerical simulation results were presented as well as the results of the laboratory tests. First assessments were given about the respective consequences and about how these consequences could be considered in the layout of future steel composite structures. [less ▲]

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See detailROSploit: Cybersecurity tool for ROS
Rivera, Sean UL; Lagraa, Sofiane UL; State, Radu UL

in International Conference on Robotic Computing (2019, February)

Abstract—Robotic Operating System(ROS) security research is currently in a preliminary state, with limited research in tools or models. Considering the trend of digitization of robotic systems, this lack ... [more ▼]

Abstract—Robotic Operating System(ROS) security research is currently in a preliminary state, with limited research in tools or models. Considering the trend of digitization of robotic systems, this lack of foundational knowledge increases the potential threat posed by security vulnerabilities in ROS. In this article, we present a new tool to assist further security research in ROS, ROSploit. ROSploit is a modular two-pronged offensive tool covering both reconnaissance and exploitation of ROS systems, designed to assist researchers in testing exploits for ROS. [less ▲]

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See detailReal-time attack detection on robot cameras: A self-driving car application
Lagraa, Sofiane UL; Cailac, Maxime; Rivera, Sean UL et al

in International Conference on Robotic Computing (2019, February)

The Robot Operating System (ROS) are being deployed for multiple life critical activities such as self-driving cars, drones, and industries. However, the security has been persistently neglected ... [more ▼]

The Robot Operating System (ROS) are being deployed for multiple life critical activities such as self-driving cars, drones, and industries. However, the security has been persistently neglected, especially the image flows incoming from camera robots. In this paper, we perform a structured security assessment of robot cameras using ROS. We points out a relevant number of security flaws that can be used to take over the flows incoming from the robot cameras. Furthermore, we propose an intrusion detection system to detect abnormal flows. Our defense approach is based on images comparisons and unsupervised anomaly detection method. We experiment our approach on robot cameras embedded on a self-driving car. [less ▲]

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See detailA View-invariant Framework for Fast Skeleton-based Action Recognition Using a Single RGB Camera
Ghorbel, Enjie UL; Papadopoulos, Konstantinos UL; Baptista, Renato UL et al

in 14th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, Prague, 25-27 February 2018 (2019, February)

View-invariant action recognition using a single RGB camera represents a very challenging topic due to the lack of 3D information in RGB images. Lately, the recent advances in deep learning made it ... [more ▼]

View-invariant action recognition using a single RGB camera represents a very challenging topic due to the lack of 3D information in RGB images. Lately, the recent advances in deep learning made it possible to extract a 3D skeleton from a single RGB image. Taking advantage of this impressive progress, we propose a simple framework for fast and view-invariant action recognition using a single RGB camera. The proposed pipeline can be seen as the association of two key steps. The first step is the estimation of a 3D skeleton from a single RGB image using a CNN-based pose estimator such as VNect. The second one aims at computing view-invariant skeleton-based features based on the estimated 3D skeletons. Experiments are conducted on two well-known benchmarks, namely, IXMAS and Northwestern-UCLA datasets. The obtained results prove the validity of our concept, which suggests a new way to address the challenge of RGB-based view-invariant action recognition. [less ▲]

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See detailTeachers´ Attitudes toward Students with High- and Low-Educated Parents
Pit-Ten Cate, Ineke UL; Glock, Sabine UL

Scientific Conference (2019, February)

Background In several countries, school tracking is used to group students with similar academic potential to optimize instruction. Teachers often have a more or less deciding vote, which school track ... [more ▼]

Background In several countries, school tracking is used to group students with similar academic potential to optimize instruction. Teachers often have a more or less deciding vote, which school track would suit different students based on academic achievement and potential (Ansalone and Biafora, 2004). Given the differential qualifications associated with completion of the different school tracks, teachers’ abilities to correctly assign students to different tracks will not only affect the students´ educational pathways, but also has a long lasting effect on career opportunities and general wellbeing in future adult life. Research shows that tracking recommendations mainly rely on students’ abilities (e.g., Caro, et al., 2009; Klapproth, et al., 2013; Marks, 2006). However, non-academic related student characteristics such as the socioeconomic status (SES) of the parents and —closely related (Reardon, 2011)—the parental educational level also affect teachers´ tracking decisions, either indirectly via grades or directly via the tracking decision itself (Bauer and Riphahn, 2006; Caro et al., 2009; de Boer, et al., 2010; Ditton, Krüsken, and Schauenberg, 2005; Maaz, et al., 2008; Timmermans, et al., 2015; Wagner, et al., 2009). Indeed, research has provided evidence for such stereotype bias in teachers’ judgments, leading to disadvantages for certain social groups (Peterson, et al., 2016; van den Bergh, et al., 2010). Hence, the aim of our study was the investigation of teachers’ attitudes toward students in relation to the educational level of parents. Method The aim of the current study was to investigate teachers´ implicit and explicit attitudes toward students with differentially educated parents. Implicit attitudes were measured using an implicit association task (IAT). The first name of the student was used as a proxy for the educational level of parents (see Onland & Bloothooft, 2008), whereby we created separate versions for boys and girls. Participating teachers (N=70) were randomly divided in two groups whereby the first group completed the IAT-boys version and the other group the IAT-girls version. Explicit attitudes were measured using a questionnaire (adapted from Glock, et al., 2016). Results: Participants indicated positive implicit attitudes toward students with highly educated parents, independent of the gender of the student. More specifically, an independent t test revealed that the mean IAT-D scores for boys and girls did not differ, t(68)=0.47, p=.64, d=0.12. The IAT-D score for the whole sample (M=0.81, SD=0.61) was significantly different from zero, t(69)=11.14, p<.001, d=1.33, reflecting more positive implicit attitudes toward highly educated parents. Teachers did not express differential explicit beliefs regarding the learning and social behaviors of students based on the educational level of the parents (i.e., subscale scores were significantly lower than the mean of the scale, t(65)=4.26, p<.001, d=0.53), whereas their expectations concerning the motivation and ambitions or educational chances of these students were neutral. Although the three subscales within the explicit attitudes measure were substantially associated (correlations ranging from r = .39 to r =.74), no association between explicit and implicit attitudes measures was found (correlations range from r = -.07 to r = .08). Conclusion: Teachers’ attitudes seem to be an important factor, which can guide teachers´ judgments and behaviors, and could partly explain differences in educational equity for students with similar academic profiles, but differentially educated parents. The positive implicit attitudes in favor of students with highly educated parents imply more favorable judgments for and behavior toward these students and deeper work is required to ensure teachers’ fair treatment of all students. The dissociation between implicit and explicit attitudes may be an indication of the social sensitivity of the relationship between students´ social background and educational achievements and opportunities. [less ▲]

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See detailInklusion aus der Sicht von Kindern mit dem Förderschwerpunkt Lernen – Überprüfung von Messinvarianz in verschiedenen schulischen Kontexten
Knickenberg, Margarita; Zurbriggen, Carmen UL; Venetz, Martin

Scientific Conference (2019, February)

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See detailHow to Assess the Usability Metrics of E-Voting Schemes
Marky, Karola; Zollinger, Marie-Laure UL; Funk, Markus et al

in Lecture Notes in Computer Science (2019, February)

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See detailTowards Learning-Aided Configuration in 3D Printing: Feasibility Study and Application to Defect Prediction
Amand, Benoit; Cordy, Maxime UL; Heymans, Patrick et al

in Proceedings of the 13th International Workshop on Variability Modelling of Software-Intensive Systems, VAMOS 2019, Leuven, Belgium, February 06-08, 2019 (2019, February)

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See detailCan Rawlsians be constitutional deliberative democrats?
Burks, Deven UL

Scientific Conference (2019, January 31)

Most see Rawls as a “constitutionalist” rather than a “proceduralist”. He insists that the basic schedule of freedoms, rights and governing procedures, once established, be removed from the table of ... [more ▼]

Most see Rawls as a “constitutionalist” rather than a “proceduralist”. He insists that the basic schedule of freedoms, rights and governing procedures, once established, be removed from the table of governmental and democratic decision-making. Pragmatically, that schedule must be fixed to avoid majoritarian domination, acrimonious bargaining and gridlock and to realize the stabilizing effect of a permanent public set of institutional arrangements and values. Morally, one must affirm only those institutional principles which one would choose in perpetuity, for past, present and future generations. Accordingly, Rawlsians might wonder what good can come of constitutional deliberative democracy, i.e. enabling citizens to formulate and modify the constitution, potentially undermining its stability? Though a necessary element of any just political order and a great political good, stability is only such when stable institutions are also just and guarantee the “fair value of political liberty”, namely that “citizens similarly gifted and motivated have roughly an equal chance of influencing the government’s policy and of attaining positions of authority irrespective of their economic and social class” (Rawls 2005: 358). Formal equality is no replacement for effective equality. Despite lamenting that “one of the main defects of constitutional government has been the failure to insure the fair value of political liberty” (Rawls 1999: 198), Rawls’s institutional vision remains largely within familiar representative and electoral logics. His threefold view of deliberative democracy is similarly limited: an idea of public reason, an institutional framework including a deliberative legislature, and public uptake of the public reason idea(l) (Rawls 2005: 448). Accordingly, I argue that Rawls and his “fair value guarantee” are better served by promoting both freestanding and embedded citizen deliberation on constitutional arrangements. This vehicle for the fair value guarantee is more easily attainable than the transition to a his preferred alternative for political economy, “property-owning democracy” (Rawls 2001: §41) and may fulfill similar aims. Finally, I review two remaining objections from Rawlsians concerning compelled participation and institutional pluralism. All in all, given Rawls’s prominence in political theory, showing that Rawlsians can be constitutional deliberative democrats may help bring another piece to the constitutional deliberative democratic coalition. [less ▲]

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See detailGeneralizations of single-peakedness
Devillet, Jimmy UL

Scientific Conference (2019, January 30)

We establish a surprising connection between a family of conservative semigroups, which includes the class of idempotent uninorms, and the concepts of single-peakedness and single-plateaudness, introduced ... [more ▼]

We establish a surprising connection between a family of conservative semigroups, which includes the class of idempotent uninorms, and the concepts of single-peakedness and single-plateaudness, introduced in social choice theory by D. Black. We also introduce a generalization of single-peakedness to partial orders of join-semilattices and show how it is related to the class of idempotent and commutative semigroups. Finally, we enumerate those orders when the corresponding semigroups are finite. [less ▲]

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See detailROLE OF TARGETED BIOCHAR-ACTIVATION IN THE REMOVAL OF MACRO- AND MICROPOLLUTANTS FROM SECONDARY EFFLUENT WASTEWATER
Brunhoferova, Hana UL; Venditti, Silvia UL; Hansen, Joachim UL

in Book of Abstracts 8th International Symposium On Wetland Pollutant Dynamics and Control (2019, January 30)

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See detailGP hyper-heuristic for the travelling salesman problem
Duflo, Gabriel UL; Kieffer, Emmanuel UL; Danoy, Grégoire UL et al

Scientific Conference (2019, January 29)

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See detail"A Colônia Luxemburguesa" – Trajectories made of Steel
Santana, Dominique UL

Scientific Conference (2019, January 25)

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See detailIslamic Finance and Economic Growth: New Evidence
Lehnert, Thorsten UL

Scientific Conference (2019, January 24)

While extensive work has shown that conventional banking development is generally conducive to economic growth, there are only a limited number of studies that investigate the impact of Islamic banking ... [more ▼]

While extensive work has shown that conventional banking development is generally conducive to economic growth, there are only a limited number of studies that investigate the impact of Islamic banking. Importantly, the literature on conventional banking claims that a reverse causality from economy performance to banking may exists, but existing studies on Islamic banking fail to address this potential endogeneity problem. This paper tackles this problem and explores the relationship between Islamic banking development and economic performance in a sample of 32 developed and developing countries based on data spanning the 2000 to 2016 period. The findings show that, although Islamic banks are considered small relative to the total size of the financial sector, Islamic banking is positively correlated with economic growth even after controlling for financial structure, macroeconomic factors and other variables. The outcome is robust across different econometric specifications like pooling OLS, fixed effects, panel data with over-identified GMM, and dynamic difference GMM. The results are confirmed on two different indicators of Islamic banking and hold for different time periods. [less ▲]

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See detailSC2Share: Smart Contract for Secure Car Sharing
Akash, Madhusudan; Symeonidis, Iraklis UL; A. Mustafa, Mustafa et al

in International Conference on Information Systems Security and Privacy (ICISSP) (2019, January 24)

This paper presents an efficient solution for the booking and payments functionality of a car sharing system that allows individuals to share their personal, underused cars in a completely decentralized ... [more ▼]

This paper presents an efficient solution for the booking and payments functionality of a car sharing system that allows individuals to share their personal, underused cars in a completely decentralized manner, annulling the need of an intermediary. Our solution, named SC2Share, leverages smart contracts and uses them to carry out secure and private car booking and payments. Our experiments on SC2Share on the Ethereum testnet guarantee high security and privacy to its users and confirm that our system is cost-efficient and ready for practical use. [less ▲]

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See detailDesign of a (yet another?) DevOps course
Capozucca, Alfredo UL; Guelfi, Nicolas UL; Ries, Benoît UL

in Bruel, Jean-Michel; Mazzara, Manuel; Meyer, Bertrand (Eds.) Software Engineering Aspects of Continuous Development and New Paradigms of Software Production and Deployment (2019, January 19)

DevOps have received marginal attention inside the higher education level curricula despite of its boom in the industrial sector. This paper presents the design of an academic master-level course aimed at ... [more ▼]

DevOps have received marginal attention inside the higher education level curricula despite of its boom in the industrial sector. This paper presents the design of an academic master-level course aimed at DevOps. The proposed design is based on earlier experiences in teaching DevOps-related topics. The specification of the course design is provided using the SWEBOK Guide and Bloom’s taxonomy to enhance the quality of the course design specification, and ease its assessment once delivered. [less ▲]

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See detailMagnetic and free-layer properties of MgO/(Co)FeB/MgO structure: Dependence on CoFeB composition
Bersweiler, Mathias UL

Scientific Conference (2019, January 17)

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See detailAssessing the impact of attacks on OPC-UA applications in the Industry 4.0 era
Polge, Julien UL; Robert, Jérémy UL; Le Traon, Yves UL

in 16th IEEE Annual Consumer Communications & Networking Conference (CCNC), Las Vegas, 11-14 January 2019 (2019, January 11)

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See detailComment assurer la qualité de l’évaluation par les pairs des propositions de communication dans le cadre d’un colloque scientifique ?
Milmeister, Marianne UL; Weis, Christiane UL; Dierendonck, Christophe UL

Scientific Conference (2019, January 10)

L’évaluation par les pairs joue un rôle important dans le monde universitaire et est souvent considérée comme le garant de la qualité scientifique. En même temps, les biais qui existent pour ce type ... [more ▼]

L’évaluation par les pairs joue un rôle important dans le monde universitaire et est souvent considérée comme le garant de la qualité scientifique. En même temps, les biais qui existent pour ce type d’évaluation sont multiples (partialité des évaluateurs, divergence de jugement entre évaluateurs, etc.) et bien documentés dans la littérature. Dans le cadre d’un colloque que nous avons organisé en 2018, nous avons mené une analyse exploratoire sur la base de données des évaluations réalisées par les pairs. Le but était d’avoir une idée de la qualité de l’évaluation par les pairs, de voir dans quelle mesure on retrouve les biais relevés par la littérature scientifique et, enfin, de définir des pistes qui pourraient contribuer à améliorer la qualité de ce processus. Dans le cas de notre colloque, l’évaluation par les pairs s’est faite via une plateforme en ligne. Chaque proposition de communication était évaluée de manière anonyme par deux personnes et sur base de neuf critères pour lesquels les évaluateurs pouvaient choisir entre quatre modalités d’appréciation : très faible, faible, bon, très bon. Ensuite, l’évaluateur devait donner sa recommandation pour la contribution analysée : acceptation, acceptation sous réserve d’ajustements ou refus. Une première analyse des données montre notamment qu’il existe des différences plus ou moins importantes tant entre les jugements des évaluateurs qu’entre les décisions d’un même évaluateur. Les résultats détaillés de nos analyses seront présentés lors du colloque et des pistes d’amélioration discutées. [less ▲]

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See detailEvaluation de l’engagement scolaire d’élèves en secondaire : quels facteurs sous-jacents sont en jeu ?
Kerger, Sylvie UL; Milmeister, Paul UL; Dierendonck, Christophe UL et al

in Actes du colloque of the 31ème coloque de l'ADMEE-Europe (2019, January 09)

Dans cette communication, nous allons, dans une perspective d’évitement du décrochage scolaire, nous pencher sur l’évaluation de l’engagement scolaire d’élèves en enseignement secondaire. Plus précisément ... [more ▼]

Dans cette communication, nous allons, dans une perspective d’évitement du décrochage scolaire, nous pencher sur l’évaluation de l’engagement scolaire d’élèves en enseignement secondaire. Plus précisément, nous tentons de mieux comprendre comment certains facteurs sous-jacents conditionnent ce dernier. En effet, l’engagement scolaire de l’élève peut être aussi bien lié à des facteurs individuels (sexe, catégorie socio-culturelle), qu’à des facteurs externes, tels que l’environnement scolaire. Nous posons les deux hypothèses suivantes : (1) Les élèves fréquentant les filières moins prestigieuses, ayant redoublé, ou issus d’un milieu social défavorable sont moins impliqués cognitivement (engagement cognitif) et ont plus souvent un comportement perturbateur (engagement comportemental). (2) Les perceptions de l’environnement scolaire et l’engagement scolaire des élèves sont associées positivement. Après avoir questionné 1473 élèves luxembourgeois, nous avons constaté que les facteurs individuels (le genre, position sociale des familles et la filière fréquentée) ne sont pas associés significativement à l’engagement cognitif des élèves, mais sont liés à l’engagement comportemental social (respect des règles). Les facteurs contextuels (perception de l'environnement scolaire, relation entre élèves et entre élèves et personnel, les climats éducatif, de justice, d’appartenance, de sécurité et la perception du bâtiment scolaire ainsi que l’orientation des buts centrés sur l’apprentissage ou sur la performance) sont liés aux deux variables dépendantes (engagement cognitif et engagement comportemental). Nos données confirment par ailleurs que l’orientation de l’école vers la performance est négativement liée à l’engagement des élèves. Nos deux hypothèses sont partiellement confirmées. Les deux variables dépendantes se distinguent en ce sens que l’engagement cognitif est lié quasi uniquement aux variables contextuelles, alors que les comportements perturbateurs sont aussi bien liés à des variables individuelles que contextuelles. Nos résultats montrent que l’évaluation de l’engagement scolaire peut fournir des informations aux enseignants permettant la mise en place de mesures pédagogiques agissant p.ex. sur les facteurs externes afin d’améliorer l’engagement scolaire des élèves. [less ▲]

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See detailTowards Optimized Deployment of Electric Bus Systems Using Cooperative ITS
Laskaris, Georgios UL; Seredynski, Marcin; Viti, Francesco UL

Poster (2019, January)

In this paper we analyze the impact of using cooperative intelligent transportation systems (C-ITS) to manage electrical bus systems. A simulation-based study is presented where three control strategies ... [more ▼]

In this paper we analyze the impact of using cooperative intelligent transportation systems (C-ITS) to manage electrical bus systems. A simulation-based study is presented where three control strategies are used to regulate the operations of a line, namely bus holding, Green Light Optimal Dwell Time Adaptation (GLODTA) and Transit Signal Priority (TSP). The results show, using a realistic scenario of a major line in Luxembourg City, that buses are efficiently operated without necessarily providing additional priority to public transport, hence without negatively affecting the capacity of the private vehicles system. Benefits in terms of headway regulations, energy consumption and travel time variance reductions are quantified. [less ▲]

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See detailGender differences with regard to physical activity motivation and behavior in physical education and leisure time
Hutmacher, Djenna UL; Eckelt, Melanie UL; Bund, Andreas UL et al

Scientific Conference (2019, January)

Objectives: Given a widespread continuous decrease in children’s and adoles-cents’ physical activity (PA), the potential of physical education (PE) in promoting young people’s PA motivation and behavior ... [more ▼]

Objectives: Given a widespread continuous decrease in children’s and adoles-cents’ physical activity (PA), the potential of physical education (PE) in promoting young people’s PA motivation and behavior has become a key issue in research. Based on the self-determination theory (SDT) of Deci and Ryan (1985), the present study aimed to ex-amine gender differences with regard to PA motivation and behavior during PE and lei-sure time (LT). Previously, girls were found to be more self-determined than boys (Wil-liams & Deci, 1996), but showed lower self-reported PA and were meeting the PA guide-lines of the WHO to a lesser extent (Trost et al., 2002). Method: 244 students (139 girls and 125 boys) from 11 to 21 years participated in the study. PA motivation was assessed via a digital questionnaire containing the scales need support (Standage, Duda and Ntoumanis, 2005), basic needs (BPNES; Vlachopou-los, Ntoumanis & Smith, 2010), external and intrinsic motivation in PE (PLOC-R; Vla-chopoulos et al., 2011) and in LT (BREQ-II; Markland & Tobin, 2004). PA behavior was measured through a self-report questionnaire (Schmidt, Will, Henn, Reimers & Woll, 2016). Additionally, 76 students (38 girls and 38 boys) wore an accelerometer (ActiGraph GT3X-BT) over seven consecutive days to measure PA behavior objectively, too. Results: With regard to PA motivation, girls reported a lower fulfillment in the basic need of competence during PE and scored higher in the external motivation during PE and LT than boys. In contrast, boys reported higher rates of intrinsic motivation during PE and LT. Concerning PA behavior, boys showed higher PA than girls for self-reported and objectively measured PA in PE and LT. Independently of gender, higher levels of intrinsic motivation were associated with increased self-reported PA. Discussion: In conflict with previous findings, girls reported a lower intrinsic motiva-tion in PA than boys. As girls simultaneously show lower self-reported and objectively measured PA, future intervention programs should focus on strengthening the more in-ternally driven behavior of girls in order to foster regular PA. Key Reference: Deci, E.L. & Ran, R.M. (1985). Intrinsic motivation and self-determination in human behav-ior. New York: Plenum Press. [less ▲]

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See detailKomparatistik als Praxis der Freiheit (Hans-Jost Frey, Werner Hamacher)
Kohns, Oliver UL

Scientific Conference (2019, January)

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See detailA Markov Chain Monte Carlo Approach for Estimating Daily Activity Patterns
Scheffer, Ariane Hélène Marie UL; Bandiera, Claudia; Cantelmo, Guido et al

Poster (2019, January)

Determining the purpose of trips brings is a fundamental information to evaluate travel demand during the day and to predict longer-term impacts on the population’s travel behavior. The concept of tours ... [more ▼]

Determining the purpose of trips brings is a fundamental information to evaluate travel demand during the day and to predict longer-term impacts on the population’s travel behavior. The concept of tours is the most suited to consider the value of a daily scheduling of individuals and travel interdependencies. However, the meticulous care required for both collecting data of high quality and interpret results of advanced demand models are frequently considered as major drawbacks. The objective of this study is to incorporate into a standard trip-based model some inherent concepts of activity-based models in order to enhance the representation of travel behavior. The main focus of this work is to infer, employing utility theory, the trip purpose of a population, at a zonal level. Making use of Markov Chain Monte Carlo, a set of parameters is estimated in order to retrieve tour-based primitives of the demand. The main advantage of this methodology is the low requirements in terms of data, as no individual information are used, and the good interpretation of the model. Estimated parameters of the priors set a utility-based probability function for departure time, which allows to have a dynamic overview of the demand. In order to account for the tour consistency of travel decisions, a duration constraint is added to the model. The proposed model is applied to the region of Luxembourg city and the results show the potential of the methodologies for dividing an observed demand based on the activity at destination. [less ▲]

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See detailElucidation of influencing parameters of the laser butt welding process of dissimilar steel to tungsten alloy sheets
Schiry, Marc UL; Plapper, Peter UL

in Proceedings: International Conference on Competitive Manufacturing COMA'19 (2019, January)

Laser welding of steel - tungsten alloy joints requires deep understanding of the impact of the laser parameters on the welding process. Due to the dissimilar thermal and metallurgical properties of both ... [more ▼]

Laser welding of steel - tungsten alloy joints requires deep understanding of the impact of the laser parameters on the welding process. Due to the dissimilar thermal and metallurgical properties of both materials, a defined heat input and a precise temperature control in the weld interface is required. In the presented work, the influence of different laser parameter (e.g. laser power, focal position, scanner speed etc.) on the joint quality of laser welded steel / tungsten alloy butt-joints were investigated. By using statistical methods, the influencing process parameters were defined and optimized. It is shown that the horizontal focal position is the main parameter for the welding process in a butt-joint configuration. Additionally, manipulation of the heat input leads to modifications of the weld bead profile. By obtaining vertical seam boundaries in the sheet metal, a homogenous temperature profile at the interface of the materials to be welded was achieved. Due to the complete bonding and low amount of intermetallic phases, high shear strength accompanied with a low variance were the result. [less ▲]

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See detailLa mesure des représentations et des pratiques parentales et leur mise en relation avec le développement des premières compétences numériques auprès d'élèves luxembourgeois du préscolaire.
Poncelet, Débora UL; Tinnes-Vigne, Mélanie; Dierendonck, Christophe UL

in Gremion, Christophe; Sylvestre, Emmanuel; Younes, Nathalie (Eds.) Actes du 31ème colloque scientifique international de l'Admée-Europe: Entre normalisation, contrôle et développement formatif. Evaluation sources de synergies ? (2019, January)

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See detailNovel Opportunities by Laser Welding of Dissimilar Materials
Schiry, Marc UL; Plapper, Peter UL

in Proceedings of International Conference on Competitive Manufacturing COMA'19 (2019, January)

The Laser Technology Competence Centre (LTCC) of the University of Luxembourg provides skills in joining material combinations, which are considered being non-weld able with traditional methods or at ... [more ▼]

The Laser Technology Competence Centre (LTCC) of the University of Luxembourg provides skills in joining material combinations, which are considered being non-weld able with traditional methods or at least challenging to join (e.g. Copper and Aluminium, Aluminium and Polyamide (PA), Titanium and PEEK, steel and tungsten hard alloy). Related accomplishments include minimal intermetallic compounds, convincing mechanical and superior electrical properties of the laser-welded specimen. With defined spatial and temporal modulation of the laser beam, an accurately defined temperature profile is created on the lower side of the upper material in the two dimensional directions, which enable joining of dissimilar materials in overlap configurations, despite challenging thermal properties. To weld butt-joint geometries with minimal heat affected volume, the temperature profiles were expanded in the third dimension, which can be achieved through controlled laser energy guidance. The scientific methods to accomplish these convincing results are explained, with selected industrial use cases ranging from automotive industry, energy storage, and medical implants. An outlook with unsolved challenges is intended to ignite discussions about upcoming research topics. [less ▲]

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See detailMixed hybrid and electric bus dynamic fleet management in urban networks: a model predictive control approach
Rinaldi, Marco UL; Picarelli, Erika; Laskaris, Georgios UL et al

Scientific Conference (2019, January)

Reducing pollutant emissions and promoting sustainable mobility solutions, including Public Transport, are increasingly becoming key objectives for policymakers worldwide. In order to jointly achieve ... [more ▼]

Reducing pollutant emissions and promoting sustainable mobility solutions, including Public Transport, are increasingly becoming key objectives for policymakers worldwide. In order to jointly achieve these goals, careful consideration should be put on the operational cost and management of PT services, in order to promote the adoption of green mobility solutions and advanced management techniques by operators. In this work we develop a dynamic fleet management approach for next generation Public Transportation systems, considering the instance of mixed electric / hybrid fleet. Our objective is that of investigating to what extent electrification, coupled with optimal fleet management, can yield operational cost savings for PT operators, explicitly considering real-time disturbances, including delays, service disruptions etc. We propose a Mixed Integer Linear Program to address the problem of optimal scheduling of a mixed fleet of electric and hybrid / non-electric buses, and employ it as predictor in a Model Predictive Control approach. Test results based upon a real-life scenario showcase how the proposed approach is indeed capable of yielding a sizable reduction in operational costs, even when considerable disturbances arise from the underlying system. [less ▲]

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See detailAggregation of MQTT Topics over Integrated Satellite Terrestrial Networks
Palattella, Maria Rita UL; Soua, Ridha UL; Stemper, André UL et al

in ACM SIGMETRICS Performance Evaluation Review (2019, January)

The MQTT application protocol was originally designed for monitoring a oil pipeline through the desert by collecting sensor data via satellite link. Thus, by design MQTT is very suitable for data ... [more ▼]

The MQTT application protocol was originally designed for monitoring a oil pipeline through the desert by collecting sensor data via satellite link. Thus, by design MQTT is very suitable for data collection over integrated satellite-terrestrial networks. Leveraging on the MQTT Bridge functionality, in this work we propose a novel architecture with two MQTT Brokers located at the satellite terminal and the satellite gateway. By using the topic pattern option, supported by the bridge, a subscriber can request several topics within a single request. To reduce the amount of traffic ex-changed over the satellite return channel, we introduce in the architecture a new entity, namely MQTT message aggregation filter, which aggregates all the MQTT topics matching the topic pattern in the same response. [less ▲]

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See detailLateralization for faces in prereaders depends on the perceptual processing level: An EEG Fast Periodic Visual Stimulation study
Lochy, Aliette UL; Schiltz, Christine UL; Rossion, Bruno

Poster (2019, January)

The developmental origin of human adults’ right hemispheric lateralization to face stimuli is unclear, in particular because young infants’ right hemispheric advantage in face perception is no longer ... [more ▼]

The developmental origin of human adults’ right hemispheric lateralization to face stimuli is unclear, in particular because young infants’ right hemispheric advantage in face perception is no longer present in preschool children, before written language acquisition. Here we used fast periodic visual stimulation (FPVS) with scalp electrophysiology to test 52 preschool children (5 years old) at two levels of face processing (i.e., faces vs. objects, or discrimination between individual faces). While the contrast between faces and nonface objects elicits strictly bilateral occipital responses in children, discrimination of faces on the basis of identity in the same children is associated with a strong right hemispheric lateralization over the occipito-temporal cortex. Inversion of the face stimuli does not modulate right lateralization but significantly decreases the discrimination response. Furthermore, there is no relationship between right hemispheric lateralization in individual face discrimination and preschool levels of letter recognition. These observations suggest that right lateralization for face perception is essentially driven by the necessity to process faces at the level of identity. Overall, they also challenge the view that the adult right hemispheric lateralization for face perception emerges late and slowly during childhood due to increased competition with left lateralized posterior network for reading. [less ▲]

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See detailMethodological Aspects of Software Engineering, Assurance, Quality, and Reliability Engineering (MAS/AQR) 2019 Welcome from the Minitrack Co-Chairs
Tenbergen, Bastian; Ries, Benoît UL

in Proceedings of the 52nd Hawaii International Conference on System Sciences (HICSS) (2019, January)

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See detailAutonomy and EU Competences in the Context of Free Trade and Investment Agreements
Neframi, Eleftheria UL; Gatti, Mauro UL

in Bosse Platiere, Isabelle; Rapoport, Cecile (Eds.) Negotiation and Conclusion of the New Generation of Free Trade Agreements (2019)

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See detailInterozeptive Genauigkeit: Ein methodischer Vergleich von zwei Heartbeat Tracking Paradigmen
Haciahmet, C.; Opdensteinen, K.; Schaan, L. et al

in Kirschbaum, C. (Ed.) 45. Jahrestagung Psychologie und Gehirn - Abstractband (2019)

Diese Arbeit untersucht zwei Herzschlagwahrnehmungsaufgaben mit unterschiedlichen Verarbeitungsmodi - Heartbeat Tracking Task (HTT; Schandry, 1981) und adaptierter Heartbeat Tracking Task (aHTT; adaptiert ... [more ▼]

Diese Arbeit untersucht zwei Herzschlagwahrnehmungsaufgaben mit unterschiedlichen Verarbeitungsmodi - Heartbeat Tracking Task (HTT; Schandry, 1981) und adaptierter Heartbeat Tracking Task (aHTT; adaptiert nach Melloni et al., 2013) - welche Interozeptive Genauigkeit (IG) anhand des Vergleichs von objektiver und selbst-berichteter Herzrate erfassen (Garfinkel et al., 2015). Die Paradigmen unterscheiden sich hinsichtlich des mentalen Zählens (HTT) und motorischen Tappings (aHTT) von kardiovaskulären Empfindungen. Tapping wird in Biofeedback-Studien zur Verbesserung der IG angewendet (Ring et al., 2015), bislang jedoch kaum mit mentalem Zählen verglichen. 74 gesunde Versuchspersonen (MAlter = 22.66, SDAlter = 2.74, 49 Frauen) bearbeiteten den HTT und den aHTT. Die IGScores des HTT waren im Durchschnitt signifikant höher als im aHTT (t(73) = 2.73, p = .01, d = .28). Bei einem Cut-Off von IG = 0.70 konnten 37 gute Herzschlagwahrnehmer/innen im HTT und 27 gute Herzschlagwahrnehmer/innen im aHTT klassifiziert werden. Auch im Selbstbericht zur eigenen Herzschlagwahrnehmungsfähigkeit, zeigte sich bei den Probanden ein höheres Konfidenzrating im HTT als im aHTT (MHTT = 5.00, SD = 2.04; MaHTT = 3.88, SD = 1.77; Z(74) = -5.24, p < .01, d = .59). Zusammenfassend weisen die Ergebnisse auf eine bessere Herzschlagwahrnehmung im HTT hin, sowohl bezüglich der IG-Scores als auch im Selbstbericht. Eine Erklärung für die niedrigeren Interozeptionswerte im aHTT könnte sein, dass die sensorische und motorische Interferenz der Tapping-Aufgaben mit der Detektion von afferenten Herzsensationen konkurrieren, weshalb der salientere Tapping-Stimulus den Aufmerksamkeitsfokus von internalen Prozessen ablenkt (Pennebaker & Hoover, 1984). Zukünftige Studien sollten prüfen, welche spezifischen Einsatzmöglichkeiten sich für HTT und aHTT anbieten, hinsichtlich einer akkuraten und ökonomischen Erfassung von IG. [less ▲]

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See detailMultisets in arithmetics
Perucca, Antonella UL

in Multimengen in der Arithmetik (2019)

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See detailNAI: The Normative Reasoner
Libal, Tomer UL; Steen, Alexander UL

in Bex, Floris (Ed.) Proceedings of the Seventeenth International Conference on Artificial Intelligence and Law (2019)

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See detailInteroception in Bulimia Nervosa: Evidence at cortical and self-report levels
Lutz, Annika UL; Van Dyck, Zoé UL; Schulz, André UL et al

in Psychophysiology (2019), 56(S1), 117

Bulimia nervosa (BN) is characterized by recurrent episodes of binge eating and compensatory behaviors, such as self- induced vomiting. Body image disturbance is also prominent in BN. Current research is ... [more ▼]

Bulimia nervosa (BN) is characterized by recurrent episodes of binge eating and compensatory behaviors, such as self- induced vomiting. Body image disturbance is also prominent in BN. Current research is trying to determine which dimensions and sensory domains of body perception are affected in BN. Regarding heartbeat perception, findings are inconclusive, with some studies reporting reduced and others reporting unaltered interoceptive accuracy in BN. The current study contributes further data on heartbeat perception by using an indicator of the cortical processing of cardio- afferent signals (heartbeat evoked potentials, HEPs). We investigated 22 women with current or partially remitted BN (BMI 23.94[3.61]; age 31.86[11.20]) and 22 healthy women (HC; BMI 24.24[3.37]; age 31.00[10.15]). Participants performed a heartbeat perception task (according to Schandry) with concurrent 64- channel- EEG and ECG recording. HEPs were calculated as mean EEG amplitudes in the interval 455- 595ms after the R- peak of the ECG. Results show no significant differences between the BN and HC groups, neither for heartbeat perception, HEPs, or mean heartrate. These results confirm previous findings of intact heartbeat perception in BN. In addition, cortical processing of cardio- afferent signals is unaltered. Heartbeat perception is particularly relevant for emotion processing and regulation. The previously reported emotion- regulation deficits in BN appear not to be based on altered CNS processing of cardiac signals [less ▲]

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See detailSignaling or Marketing? The Role of Discount Control Mechanisms
Kräussl, Roman UL; Stefanova, Denitsa UL; Joshua, Pollet

Scientific Conference (2019)

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See detailTaking Stock of the Bologna Process at 20: The Possibilities and Limits of Soft Law Governance
Harmsen, Robert UL; Deca, Ligia

Scientific Conference (2019)

The Bologna Process stands as both an exemplar of regional cooperation in the higher education policy sector and as a comparatively successful instance of the use of so-called ‘soft law governance’ policy ... [more ▼]

The Bologna Process stands as both an exemplar of regional cooperation in the higher education policy sector and as a comparatively successful instance of the use of so-called ‘soft law governance’ policy instruments. Yet, as this pan-European process now marks two decades of existence, questions are increasingly being posed as to its direction and purpose. Against this background, the present paper seeks to take stock of Bologna as it enters adulthood, drawing on both the substantial body of scholarship that has emerged on the process and practitioner insights to examine its past achievements and current challenges. The paper specifically focuses on recent debates surrounding the (non-)implementation of key commitments; on the functioning of the EHEA as a policy forum in relation to both its own membership and the wider international higher education policy landscape; and on the manner in which the EHEA may respond to increasingly serious challenges to the fundamental values that underpin the process. An overall balance sheet is finally drawn, suggesting the likely direction(s) of the process going forward. [less ▲]

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See detailA learning-based framework for automatic parameterized verification
Li, Yongjian; Cao, Jialun; Pang, Jun UL

in Proceedings of the 37th International Conference on Computer Design (ICCD) (2019)

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See detailSTV: Model Checking for Strategies under Imperfect Information
Kurpiewski, Damian; Jamroga, Wojciech UL; Knapik, Micha L

in Proceedings of the 18th International Conference on Autonomous Agents and Multiagent Systems AAMAS 2019 (2019)

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See detailAsylum seekers and refugees’ lived experiences of borders and (im)mobility. The Case of Luxembourg
Paraschivescu, Claudia UL; Oesch, Lucas UL; Nienaber, Birte UL

Scientific Conference (2019)

The mobility of people influences the (re)creation of borders through bordering practices. Conversely, borders and bordering practices affect the management of mobility and thus peoples’ migratory ... [more ▼]

The mobility of people influences the (re)creation of borders through bordering practices. Conversely, borders and bordering practices affect the management of mobility and thus peoples’ migratory trajectories. Based on in-depth qualitative interviews with refugees conducted for the H2020 project CEASEVAL, this paper explores the ways in which borders at various levels (spatial, legal, economic and social) influence migrants’ mobility before, during and after arrival in Luxembourg. As such, by focusing on the interrelations between border studies and mobility studies, it brings together two fields which have rarely been studied together, particularly when focused on refugees. This is of particular interest both empirically (given the multiple flows of people arriving in Luxembourg) and conceptually (as bordering practices relate to both practices of mobility and border making, as well as border crossing, from an institutional and experiential perspective). With 2,322 asylum applications in 2017, the Grand Duchy of Luxembourg is home to one asylum application per 254 people. This is far more that the EU-28 average, which is one application for every 787 people. Despite this, academic research depicting the everyday experiences of refugees in Luxembourg is lacking. This paper will first provide an overview of the Luxembourgish context with regards to asylum seekers and refugees. It will then analyse how bordering practices are experienced when carried out by traditional actors such as border agents. Lastly, it will shed light on the participants’ everyday experiences of borders by (non) traditional actors, such as ‘citizens’ and housing/labour market agents. It seeks to explore the ways in which the Luxembourgish politics of belonging influence the respondents’ feelings of belonging, which can further affect their (im)mobilities. [less ▲]

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See detailSequential reprogramming of Boolean networks made practical
Mandon, Hugues; Su, Cui; Haar, Stefan et al

in Proceedings of 17th International Conference on Computational Methods in Systems Biology (CMSB'19) (2019)

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See detailZur Validität zweier Herzschlagwahrnehmungsaufgaben: Höheres zentrales Blutvolumen durch Kipptischmanipulation verbessert interozeptive Genauigkeit, aber nicht die Genauigkeit zur Schätzung von Zeitintervallen
Back, S.; Schaan, V. K.; Vögele, Claus UL et al

in Kirschbaum, C. (Ed.) 45. Jahrestagung Psychologie und Gehirn - Abstractband (2019)

Kardiale Interozeption wird typischerweise mittels Herzschlagzählaufgaben (Schandry, 1981) oder Herzschlagdiskriminationsaufgaben (Whitehead et al., 1977) erfasst. Jedoch sind die Determinanten der ... [more ▼]

Kardiale Interozeption wird typischerweise mittels Herzschlagzählaufgaben (Schandry, 1981) oder Herzschlagdiskriminationsaufgaben (Whitehead et al., 1977) erfasst. Jedoch sind die Determinanten der Herzschlagwahrnehmung hinsichtlich Aktivitätsindizes des kardiovaskulären Systems bisher ungeklärt. Die vorliegende Studie untersucht, ob die experimentelle Manipulation kardiovaskulärer Aktivität durch die Variation der Körperposition mittels Kipptisch einen Einfluss auf interozeptive Genauigkeit in Herzschlagzählaufgaben und Herzschlagdiskriminierungsaufgaben hat. Studierende (N=43) führten beide Herzschlagwahrnehmungsaufgaben in drei Körperpositionen (-10°,0° und 10°) durch. Zusätzlich wurde die Fähigkeit zur Einschätzung von Zeitintervallen geprüft (Kontrollaufgabe), da oft kritisiert wurde, dass interozeptive Genauigkeit basierend auf der Herzschlagzählaufgabe mit dieser Fähigkeit konfundiert ist. Die interozeptive Genauigkeit in der Herzschlagzählaufgabe war signifikant höher bei einem Neigungswinkel von -10° (über Kopf), sowie geringer bei 10° (Kopf aufrecht), jeweils im Vergleich zu 0° (horizontale Position). Deskriptiv ist das gleiche Muster bei der Herzschlagdiskriminationssaufgabe zu erkennen, jedoch statistisch nicht signifikant. Die Einschätzungsgenauigkeit von Zeitintervallen bleibt unabhängig von der Körperposition konstant. Regressionsanalysen zeigen, dass die Fähigkeit zur Diskriminierung von Herzschlägen signifikant die Herzschlagzählgenauigkeit vorhersagt und 32% der Gesamtvarianz aufklärt. Herzrate sowie die Einschätzungsgenauigkeit von Zeitintervallen tragen nicht signifikant als Prädiktoren in der Aufklärung der Zählgenauigkeit bei. Die Ergebnisse weisen darauf hin, dass kardiodynamische Parameter, wie z.B. Schlagvolumen, die durch die Variation der Körperposition manipuliert wurden, unabhängig von Variationen der Herzrate, eine Determinante interozeptiver Genauigkeit in Herzschlagzählaufgaben darstellen. Die Einschätzung von Zeitintervallen hat keinen Einfluss auf die Zähl- und Diskriminationsgenauigkeit von Herzschlägen und wird außerdem nicht von der Körperposition beeinflusst. Die Ergebnisse weisen auf gute konvergente und diskriminante Validität der Herzschlagwahrnehmungsaufgaben zur Erfassung kardialer Interozeption hin. [less ▲]

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