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See detail3D Digital Heritage and Historical Storytelling: Outcomes from the Interreg EMR Terra Mosana Project
van Ruymbeke, Muriel UL; Nofal, Eslam; Billen, Roland

in Rauterberg, Matthias (Ed.) Culture and Computing (2022, June 16)

The paper explains how the activities undertaken in the Terra Mosana project have combined the writing of new heritage narratives with the creation of digital 3D virtual experiences. The main objective of ... [more ▼]

The paper explains how the activities undertaken in the Terra Mosana project have combined the writing of new heritage narratives with the creation of digital 3D virtual experiences. The main objective of the project was to strengthen the sense of belonging to the same community for the citizens of the Euregio Meuse-Rhine by recreating their common history and heritage in 3D. This was achieved through virtual and augmented reality experiences based on cross-border and renewed historical storylines. [less ▲]

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See detailClimate Risk and Price Jumps
Lehnert, Thorsten UL

Scientific Conference (2022, June 13)

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See detailStudying transnational events through web archives
Schafer, Valerie UL

Scientific Conference (2022, June 13)

This presentation was an update of the work of WG2 related to web archives and transnational events I'm leading within the WARCnet project.

Detailed reference viewed: 35 (1 UL)
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See detailInteractions in joint multiliteracies activities in three day care centres in Luxembourg
Kirsch, Claudine UL

Scientific Conference (2022, June 12)

Several countries have implemented multilingual programmes in early childhood education, trilingual Luxembourg being one of them. Since 2017 professionals in formal and non-formal (e.g. crèches ... [more ▼]

Several countries have implemented multilingual programmes in early childhood education, trilingual Luxembourg being one of them. Since 2017 professionals in formal and non-formal (e.g. crèches) institutions have to develop language skills in Luxembourgish /French, familiarise children with French/ Luxembourgish and value their home languages, for instance through literacy activities and common activities with parents. Many practitioners, however, are unsure of how to develop literacy in one, let alone multiple languages, and many rarely collaborate with parents. The longitudinal mixed-method research project COMPARE therefore aims to develop and explore multiliteracy and collaborative practices in the non-formal ECEC sector. The paper presents the literacy events in which parents and educators collaboratively engaged three-year-olds in three crèches in 2020-2021. The analysis of the video-recorded observations shows that the range and number of activities as well as the parents’ language use depended on the crèches. Parents tended to read and tell stories, frequently in a (prestigious) home language, and sing songs. The parent-led activities in these crèches reflected, to some extent, the pedagogical practices that 452 professionals reported in an online questionnaire completed in 2020 (Kirsch & Aleksić, 2021). We argue that collaboration with parents can propel the use of home languages in crèches and develop multiliteracy practices, but educators need to be aware of language hierarchies and have a good understanding of literacy. [less ▲]

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See detailTagungs-Resümee
Reicher, Ruth UL

Scientific Conference (2022, June 11)

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See detailWhen Cryptographic Ransomware Poses Cyber Threats: Ethical Challenges and Proposed Safeguards for Cybersecurity Researchers
Botes, Wilhelmina Maria UL; Lenzini, Gabriele UL

Scientific Conference (2022, June 10)

Cryptographic ransomware, a malware capable of destroying data, is a serious threat if used against providers of critical infrastructures such as healthcare, energy supply chains, banking services, and ... [more ▼]

Cryptographic ransomware, a malware capable of destroying data, is a serious threat if used against providers of critical infrastructures such as healthcare, energy supply chains, banking services, and transport systems. Used as such, ransomware may qualify as cyber weapon, but the current discussion around cyber and information warfare is not sufficiently legally regulated. This delegates the safe governance thereof to the application of ethical principles but leaves researchers working on ransomware in doubt about the double-use nature of their work and what code of conduct to follow. Although some existing biomedical research ethical principles have been repurposed for ICT research, in the context of recent threats posed by ransomware attacks, these efforts need an urgent rethink, especially when it involves the research of cybersecurity researchers dealing specifically with ransomware. This paper does not offer solutions, but rather describes the complexity, nature and extent of ethical challenges raised by cybersecurity research and invites the cybersecurity research community to enter into active discussions around the need to consider the development of an appropriate research ethics framework in the domain of cybersecurity. [less ▲]

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See detailUnsupervised Learning for User Scheduling in Multibeam Precoded GEO Satellite Systems
Ortiz Gomez, Flor de Guadalupe UL; Lagunas, Eva UL; Chatzinotas, Symeon UL

Scientific Conference (2022, June 09)

Future generation SatCom multibeam architectures will extensively exploit full-frequency reuse schemes together with interference management techniques, such as precoding, to dramatically increase ... [more ▼]

Future generation SatCom multibeam architectures will extensively exploit full-frequency reuse schemes together with interference management techniques, such as precoding, to dramatically increase spectral efficiency performance. Precoding is very sensitive to user scheduling, suggesting a joint precoding and user scheduling design to achieve optimal performance. However, the joint design requires solving a highly complex optimization problem which is unreasonable for practical systems. Even for suboptimal disjoint scheduling designs, the complexity is still significant. To achieve a good compromise between performance and complexity, we investigate the applicability of Machine Learning (ML) for the aforementioned problem. We propose three clustering algorithms based on Unsupervised Learning (UL) that facilitate the user scheduling decisions while maximizing the system performance in terms of throughput. Numerical simulations compare the three proposed algorithms (K-means, Hierarchical clustering, and Self-Organization) with the conventional geographic scheduling and identify the main trade-offs. [less ▲]

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See detailDevelopment of an HPC Multi-Physics Biomass Furnace Simulation and Integration in a Cloud-based Workflow
Besseron, Xavier UL; Henrik, Rusche; Peters, Bernhard UL

Scientific Conference (2022, June 09)

Biomass combustion offers a credible alternative to reduce the consumption of fossil fuels. To optimize the biomass combustion process and improve the design of biomass furnaces numerical simulation is a ... [more ▼]

Biomass combustion offers a credible alternative to reduce the consumption of fossil fuels. To optimize the biomass combustion process and improve the design of biomass furnaces numerical simulation is a less expensive and time-effective approach as opposed to the experimental method. However, the combustion in a biomass furnace involves intricate physical phenomena that must be modeled (and validated) carefully, in the fuel bed (with particle motion and shrinking, heat transfer, drying, pyrolysis, gasification) and in the surrounding gas (with turbulence, combustion, radiation). With this level of complexity, and to be conducted in a reasonable time, the simulation of industrial biomass furnaces requires the use of High-Performance Computing (HPC) platforms and expertise, which is usually not affordable for manufacturing SMEs. To address this issue, we developed a configurable digital twin of a biomass furnace running on HPC and we designed a cloudified easy-to-use end-to-end workflow. This fully automated workflow, from user input to results analysis, has been integrated into the digital marketplace of the CloudiFacturing EU project and is now directly available to SMEs via a Cloud portal. With this presentation, we want to offer a glance at the internal details and enabling technologies used in our parallel coupled application and scientific workflow. Our parallel simulation tool for biomass furnaces combines OpenFOAM (for the gas phase) parallelized with MPI and XDEM (for the solid wood particles) parallelized with OpenMP. The two libraries are coupled in parallel using an original approach based on the co-located partitioning strategy which has been tailored to minimize communications. As for the cloud workflow, it is based on an all-in-one Singularity image containing all the software, scripts, and data required to prepare the simulation input, execute the computation-intensive simulation, and analyze the results. Finally, we present the lessons learned from the development of this complex workflow and highlight the remaining challenges related to HPC multi-physics coupled simulations. [less ▲]

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See detailA survey of EMI lecturer training programmes: content, delivery, ways forward.
Deroey, Katrien UL

Scientific Conference (2022, June 09)

This talk will provide insights into designing and delivering English Medium Instruction (EMI) lecturer training by surveying published initiatives worldwide (Deroey, 2021). Although EMI is not a recent ... [more ▼]

This talk will provide insights into designing and delivering English Medium Instruction (EMI) lecturer training by surveying published initiatives worldwide (Deroey, 2021). Although EMI is not a recent phenomenon, many higher education institutions are only now beginning to organize specific support for EMI lecturers. EAP practitioners are often tasked with providing such support, since the perception commonly is that language is the main issue requiring improvement. However, the efficient design and delivery of EMI lecturing training and support is a complex challenge. First, most literature highlights the need for pedagogical and communication training in addition to language work. Second the varied EMI context means training should be adapted to the local cultural, educational, linguistic and institutional contexts (Herington, 2020; Martinez & Fernandes, 2020; Tuomainen, 2018). Third, we need to be sensitive to lecturers’ attitudes towards EMI and EMI training (Tsui, 2018). Fourth, there are practical considerations such as the timely provision of support (Guarda & Helm, 2017); promoting participation; facilitating learning transfer to lectures; and working with what are usually heterogeneous participant groups in terms of English proficiency, (EMI) lecturing experience and discipline (Ball & Lindsay, 2013). Finally, the design of these programmes typically needs to happen with very limited institutional resources, few (if any) published materials and relatively little published research on lecture discourse and EMI lecturer training. Having surveyed the main components, formats and work forms of the programmes, the conclusion highlights ways forward in EMI lecturer training that emerge from this analysis. References Ball, P., & Lindsay, D. (2013). Language demands and support for English-medium instruction in tertiary education. Learning from a specific context In A. Doiz, D. Lasagabaster, & J. M. Sierra (Eds.), English-medium instruction at universities: Global challenges (pp. 44-61). Multilingual Matters. Deroey, K. L. B. (2021). Lecturer training for English Medium Instruction: what and how? In B. D. Bond, A. & M. Evans (Ed.), Innovation, exploration and transformation. Proceedings of the 2019 BALEAP Conference (pp. 245-253). Garnet. Guarda, M., & Helm, F. (2017). A survey of lecturers’ needs and feedback on EMI training. In K. Ackerley, M. Guarda, & F. Helm (Eds.), Sharing perspectives on English-medium instruction (pp. 167-194). Peter Lang. Herington, R. (2020). Observation as a tool to facilitate the professional development of teaching faculty involved in English as a Medium of Instruction: trainer and trainee perspectives. In M. L. Carrió-Pasto (Ed.), Internationalising Learning in Higher Education (pp. 65-82). IGI Global. Martinez, R., & Fernandes, K. (2020). Development of a teacher training course for English medium instruction for higher education professors in Brazil. In M. Del Mar Sánchez-Pérez (Ed.), Teacher Training for English-Medium Instruction in Higher Education (pp. 125-152). IGI Global. Tuomainen, S. (2018). Supporting non-native university lecturers with English-medium instruction. Journal of Applied Research in Higher Education, 10(3), 230-242. [less ▲]

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See detailHEAT AND MASS TRANSFER BETWEEN XDEM & OPENFOAM USING PRECICE COUPLING LIBRARY
Adhav, Prasad UL; Besseron, Xavier UL; Estupinan Donoso, Alvaro Antonio UL et al

Scientific Conference (2022, June 09)

This work demonstrates the rapid development of a simulation environment to achieve Heat and Mass Transfer (HMT) between Discrete Element Methods (DEM) and Computa- tional Fluid Dynamics (CFD). The HMT ... [more ▼]

This work demonstrates the rapid development of a simulation environment to achieve Heat and Mass Transfer (HMT) between Discrete Element Methods (DEM) and Computa- tional Fluid Dynamics (CFD). The HMT coupling can be employed to simulate processes such as drying, pyrolysis, combustion, melting, solid-fluid reactions etc and have indus- trial applications such as biomass furnaces, boilers, heat exchangers, and flow through packed beds. This shows that diverse CFD features and solvers need to be coupled with DEM in order to achieve various applications mentioned above. The proposed DEM-CFD Eulerian-Lagrangian coupling for heat and mass transfer is achieved by employing the preCICE coupling library[1] on volumetric meshes. In our prototype, we use the eXtended Discrete Element Method (XDEM)[2] for handling DEM calculations and OpenFOAM for the CFD. The XDEM solver receives various CFD data fields such as fluid properties, and flow conditions exchanged through preCICE, which are used to set boundary conditions for particles. Various heat transfer and mass transfer laws have been implemented in XDEM to steer HMT source term computations. The heat and mass source terms computed by XDEM are transferred to CFD solver and added as source. These source terms represent particles in CFD. The generic coupling interface of preCICE, XDEM and its adapter allows to tackle a di- verse range of applications. We demonstrate the heat, mass & momentum coupling capa- bilities through various test cases and then compared with our legacy XDEM-OpenFOAM coupling and experimental results. [less ▲]

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See detailTélétravail et mobilités dans un contexte transfrontalier
Pigeron-Piroth, Isabelle UL

Scientific Conference (2022, June 09)

La Grande Région SaarLorLux se caractérise par d’intenses flux de travailleurs frontaliers qui représentent près d’un quart des flux de travail frontalier de l’ensemble de l’UE. La pandémie de Covid-19 et ... [more ▼]

La Grande Région SaarLorLux se caractérise par d’intenses flux de travailleurs frontaliers qui représentent près d’un quart des flux de travail frontalier de l’ensemble de l’UE. La pandémie de Covid-19 et le confinement total débuté en mars 2020 ont eu pour conséquence de développer le recours massif au télétravail y compris dans cet espace traversé par plusieurs frontières. Cette plongée brutale et soudaine dans le télétravail a attiré l’attention sur cette forme d’organisation du travail, assez peu utilisée et étudiée jusqu’alors. La question se pose désormais de voir comment va évoluer cette forme de travail dans un contexte transfrontalier, compte tenu des multiples règlementations en vigueur (fiscales, sécurité sociale…), par ailleurs diverses selon les pays concernés (de travail comme de résidence). Le débat a notamment été relancé avec la récente résolution européenne déposée à l’Assemblée Nationale française visant à l’augmentation du télétravail des travailleurs frontaliers et à mener une réflexion européenne sur leur statut (texte adopté n°819). Il importe alors de tenir compte des effets du télétravail sur les travailleurs frontaliers en place mais aussi sur les évolutions du travail frontalier. Doit-on s’attendre à une forte hausse du travail frontalier si le télétravail se généralise ? Comment seront alors impactées les mobilités des frontaliers ? L’objectif de la présente communication est de dresser une liste des effets potentiels du télétravail sur les mobilités (quotidiennes et résidentielles) dans un contexte transfrontalier. Comment le télétravail peut-il impacter les pratiques de mobilités des frontaliers ? constitue-t-il une solution envisageable et réaliste face aux problèmes de congestion autour du Luxembourg ? ou y a-t-il des effets-rebonds qui nuanceraient cet impact du télétravail sur les mobilités? Autant de questions qui constituent une étape préliminaire avant toute tentative de mesure ou de prise en compte de l’effet télétravail dans l’analyse du marché du travail transfrontalier dans la Grande Région. Méthodologie En partant d’une analyse de la littérature sur le sujet, souvent abordé de manière « nationale » donc sans tenir compte des particularités liées aux frontières, nous complèterons ce tour d’horizon par nos propres travaux sur la question et notre connaissance du contexte transfrontalier. Principaux résultats obtenus ou attendus Une réflexion générale sera engagée quant aux effets attendus du télétravail sur les mobilités transfrontalières, à la fois au niveau macro, meso et micro. Il importera de distinguer les impacts sur les travailleurs frontaliers déjà en place et sur ceux qui sont potentiellement candidats à un emploi transfrontalier, mais aussi de tenir compte du fait que tous les emplois ne sont pas télétravaillables par exemple (selon le secteur ou le type d’emploi). Cet inventaire détaillé nous permettra de conclure sur l’intérêt de la prise en compte de la variable télétravail dans les futures analyses du travail frontalier, mais également nous fournira des pistes d’études concrètes à réaliser. [less ▲]

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See detailDigital Storytelling: Strategies and Tools for Doing History Online
Camarda, Sandra UL

Scientific Conference (2022, June 08)

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See detailA CutFEM Method for a Mechanistic Modelling of Astrocytic Metabolism in 3D Physiological Morphologies
Farina, Sofia UL; Voorsluijs, Valerie UL; Claus, Susanne et al

Scientific Conference (2022, June 07)

Investigating neurodegenerative diseases can be done complementary through biological and computational experiments. A good computational approach describing a simplification of the reality and focusing ... [more ▼]

Investigating neurodegenerative diseases can be done complementary through biological and computational experiments. A good computational approach describing a simplification of the reality and focusing only on some features of the problem can help getting insights on the field. The question addressed in our work is the role of astrocytes in neurodegeneration. These cells have two interesting characteristics that we want to investigate in our model: first, their role as metabolic mediator between neurons and blood vessels and second, their peculiar morphology. In fact, metabolic dysfunctions and morphological changes have been noticed in astrocyte affected by neuropathology. Computationally the main difficulty arising from solving a metabolic model into cellular shape comes from the complexity of the domain. The shape of astrocytes are very ramified, with thin branches and sharp edges. As shown in our previous work \cite{Farina}, a \cutfem{} \cite{Burman} approach is a suitable tool to deal with this issue. In our latest work we use real human three-dimensional astrocyte morphologies obtained via microscopy \cite{Salamanca} as domain to solve our system. The performed simulations highlight the effect of morphological changes on the system output. Suggesting that our model can be crucial in understanding the morphological-dependency in neuropathologies and that the spatial component cannot be neglected. [less ▲]

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See detailData Protection and Consenting Communication Mechanisms: Current Proposals and Challenges
Human, Soheil; Degeling, Martin; Santos, Christiana et al

in IEEE eXplore (2022, June 06)

Data Protection and Consenting Communication Mechanisms (DPCCMs) have the potential of becoming one of the most fundamental means of protecting humans’ privacy and agency. However, they are yet to be ... [more ▼]

Data Protection and Consenting Communication Mechanisms (DPCCMs) have the potential of becoming one of the most fundamental means of protecting humans’ privacy and agency. However, they are yet to be improved, adopted and enforced. In this paper, based on the results of a technical document analysis and an expert study, we we identify some of the main technical factors that can be comparison factors between some of the main interdisciplinary challenges of a Human-centric, Accountable, Lawful, and Ethical practice of personal data processing on the Internet and discuss whether the current DPCCMs proposal can contribute towards their resolution. In particular, we discuss the two current open specifications, i.e. the Advanced Data Protection Control (ADPC) and the Global Privacy Control (GPC) based on the identified challenges. [less ▲]

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See detailImaging-informed BIOmechanical brain tumor forecast MOdelling
Abbad Andaloussi, Meryem UL; Husch, Andreas UL; Urcun, Stephane UL et al

Scientific Conference (2022, June 06)

Grade 3 and 4 Astrocytomas are high grade gliomas (HGG) that usually result from initially less aggressive low grade gliomas (LGG) through malignant transformation (MT). This process has various ... [more ▼]

Grade 3 and 4 Astrocytomas are high grade gliomas (HGG) that usually result from initially less aggressive low grade gliomas (LGG) through malignant transformation (MT). This process has various definitions in the literature, clinical and histopathological, depending on the scale of the study and researchers' interest. We introduce an overview of different aspects of MT: molecular, clinical and the role of the microenvironment in acquiring the malignant phenotype. Furthermore, we introduce a new hypothesis that could explain the spatial progression of low grade astrocytoma (LGA) during MT. The former hypothesis will next be tested on LGA patients through tumor segmentation from Medical Resonance Images (MRI) and a mechanistic growth model. [less ▲]

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See detailUsing Bayes factors to compare dynamical models of hydrological systems
Mingo Ndiwago, Damian UL; Nijzink, Remko; Ley, Christophe UL et al

Scientific Conference (2022, June 05)

Detailed reference viewed: 37 (10 UL)
See detail"Hybrid is the new normal." Einblicke in die Projekte des Luxembourg Centre for Contemporary and Digital History am Beispiel der virtuellen Ausstellungen ww1.lu, zeitschichten.be und minett-stories.lu
Brüll, Christoph UL

Scientific Conference (2022, June 03)

Seinen Forschungsschwerpunkt in der digitalen Geschichte trägt das 2017 gegründete C²DH bereits im Namen. Überlegungen zu den methodologischen Herausforderungen des Digitalen für die ... [more ▼]

Seinen Forschungsschwerpunkt in der digitalen Geschichte trägt das 2017 gegründete C²DH bereits im Namen. Überlegungen zu den methodologischen Herausforderungen des Digitalen für die Geschichtswissenschaft stehen bei seiner Arbeit genauso im Mittelpunkt wie das Nachdenken über den Einsatz digitaler Mittel bei der Vermittlung von Zeitgeschichte. Bei dieser Digital Public History spielen besonders die so genannten virtuellen Ausstellungen eine große Rolle. Der Vortrag bettet diese in einem ersten Teil in die konzeptionelle Ausrichtung des C²DH ein, bevor im zweiten Teil drei Ausstellungen vorgestellt werden: zum Ersten Weltkrieg in Luxemburg (2018), zur Geschichte Ostbelgiens seit 1920 (2020) und zur Sozial- und Industriegeschichte im luxemburgisch-französischen Grenzgebiet (2022). Besondere Aufmerksamkeit kommt der Problematisierung der Nutzung von Archivquellen in diesen Ausstellungen zu – sowohl im Zusammenspiel mit anderen (v.a. audiovisuellen) Quellen als auch aus methodischer und didaktischer Perspektive. [less ▲]

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See detailLatent classes of workplace bullying exposure and perpetration and their links to personality, power and social status
Sischka, Philipp UL

Scientific Conference (2022, June 03)

Just like many school aggression researchers (see the review of studies in Olivier et al., 2021; Smith & Steffgen, 2013), many scholars investigating workplace bullying assume the existence of four ... [more ▼]

Just like many school aggression researchers (see the review of studies in Olivier et al., 2021; Smith & Steffgen, 2013), many scholars investigating workplace bullying assume the existence of four classes of employees: Uninvolved employees, victims, perpetrator, and provocative victims (also called ‘bully-victims’; e.g., Zapf & Einarsen, 2020). Yet, empirical evidence supporting these four classes is lacking so far. Instead, studies on workplace bullying mostly focused solely on the victim perspective (Einarsen et al., 2020; see also the review of studies in Gupta et al., 2020), while far less studies investigate the perpetrator perspective (see the enumerated studies in Nielsen & Einarsen, 2018). Only some studies include both perspectives (e.g., Baillien et al., 2016; Fernández-del-Río et al., 2021; Sischka et al., 2021). However, these studies applied a variable-centered approach and treated workplace bullying exposure and perpetration as separate variables. Thus, they tell us little about the interplay of workplace bullying exposure and perpetration. The current study employs a person-centered approach (i.e., latent class analysis) to identify groups of employees that show different patterns of workplace bullying involvement. Moreover, the current study aims to identify predictors of latent class membership. We investigate the individual disposition hypothesis (Nielsen & Einarsen, 2018), assuming that individual characteristics such as personality traits may be related to being involved in bullying and could therefore be typifying features of workplace bullying groups. Moreover, according to some researchers in workplace bullying, individual characteristics such as certain personality traits (big five dimensions, trait aggression, dominance) are particularly appropriate to identify and distinguish workplace bullying subgroups (Matthiesen & Einarsen, 2007; see also Nielsen et al., 2017). On the other hand, power and social status represent enabling structures (Salin, 2003) of workplace bullying, and power imbalance is often seen as a defining feature of workplace bullying (Einarsen et al., 2020). To test our hypotheses, we recruited participants via Amazon’s Mechanical Turk (MTurk; Buhrmester et al., 2011; Crump et al., 2013) to participate in an online survey. The final sample contained 1,492 respondents (53.8% females, n = 802), with ages ranging from 19 to 77 (M = 40.2, SD = 10.8). Most respondents worked full time (91.2%, n = 1,360). The survey contained the Short-Negative Acts Questionnaire (S-NAQ; Notelaers et al., 2019) that was applied from the victim as well as from the perpetrator perspective. Furthermore, we assessed the big five with the Mini-IPIP (Donnellan et al., 2006), trait aggression with the brief aggression questionnaire (Webster et al., 2014), and dominance with the domineering subscale of the Inventory of Interpersonal Problems (Soldz et al., 1995). Moreover, power and social status were assessed with a newly developed bipartite measure of social hierarchy (Yu et al, 2019). Latent class analysis was employed. Statistical fit indices, substantive interpretability and utility, as well as classification diagnostics were jointly considered to determine the number of workplace bullying classes. To explore the relationships between the latent categorical variable and the other variables (i.e., personality traits, power and social status), we followed the three-step procedure (e.g., Asparouhov & Muthén, 2014). Latent class analysis revealed four classes, i.e., (1) mild bullying involvement, (2) bully-victims (3) non-involved and (4) victims. These classes were meaningfully linked with the big five dimensions, trait aggression, dominance, power and social status. Specifically, bully-victims scored high on extraversion, neuroticism, trait aggression, dominance, power and low on status, agreeableness, conscientiousness and openness. Victims on the other hand scored also high on neuroticism and – compared with non-involved – lower on agreeableness, conscientiousness and openness and higher on trait aggression and dominance. Victims showed the lowest levels of extraversion and status. The present study implements a cross-sectional design precluding a causal interpretation. Moreover, only self-reported measures were employed. Thus, especially indicators of workplace bullying perpetration might be influence by social desirability. Scholars and policy makers need to be aware of different patterns of being involved in workplace bullying in order to create effective interventions. Personality factors as well as power and social status are important correlates of workplace bullying involvement. The current study is the first that investigates workplace bullying from a target and a perpetrator perspective by employing a person-centered approach (i.e., latent class analysis). [less ▲]

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See detailExploring the History of Digital History: Setting an Agenda
Zaagsma, Gerben UL

Scientific Conference (2022, June 02)

See attached.

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See detailComparing MaaS Business Plans Using an Agent Based Modelling Approach
Cisterna, Carolina UL; Viti, Francesco UL; Bigi, Federico UL

Scientific Conference (2022, June 02)

The Mobility-as-a-service is based on customized bundles in which different mobility services are gathered under one subscription-based digital platform. Currently, in the literature MaaS packages have ... [more ▼]

The Mobility-as-a-service is based on customized bundles in which different mobility services are gathered under one subscription-based digital platform. Currently, in the literature MaaS packages have been customized and hypothesized through surveys and pilot projects, underlining the lack of a model able to capture and compare MaaS business plans when different bundles are provided. This study aims to simulate different MaaS plans in the users’ mode choice set using an agent-based model and to study the MaaS potential demand heterogeneity. Results show that MaaS users who experience long daily travel times are indifferent to the type of package provided, while time-limited package members substitute the car by travelling longer distances using public transport and free-floating car-sharing services. In contrast, the trip-discounted bundle members are less willing to substitute the car and they use public transport within a long trip chain, reducing their trip time [less ▲]

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See detailSignal-Oriented ECUs in a Centralized Service-Oriented Architecture: Scalability of the Layered Software Architecture
Bengtsson, Hoai Hoang; Hiller, Martin; Migge, Jörn et al

Scientific Conference (2022, June 01)

The industry is quickly moving away from a function/signal-oriented architecture towards Service-Oriented Architectures (SOA). To carry-over legacy signal-oriented ECUs during the transition phase, Volvo ... [more ▼]

The industry is quickly moving away from a function/signal-oriented architecture towards Service-Oriented Architectures (SOA). To carry-over legacy signal-oriented ECUs during the transition phase, Volvo Cars has developed a layered software (SW) architecture based on the concepts of "device proxys" (i.e., one per legacy ECU), signal real-time database and service interface. This architecture, executing on the central computer on the TSN backbone, provides a clear separation of concerns between its components with a reduced additional complexity. In this presentation, we will review the main challenges faced in the integration of signal-oriented ECUs into SOA, and present the solutions explored at Volvo with a focus on layered SW architecture in the centralized E/E architecture and its 3 core components: o Device Proxies o Signal DataBase o Service Interface We then report on the performances of this architecture in terms of latencies and conclude on the maximum number of signal-oriented frames and legacy ECUs that can be handled. The performance evaluation is conducted by simulation, with sensitivity analysis to identify the performance bottlenecks. The E/E architecture under study is a prototype TSN-based central computing architecture targeted at next-generation models. The main questions that will be discussed throughout the presentation are 1) how to efficiently handle signal to service conversion? 2) The performance and the scalability of the SW architecture proposed and 3) the suitability of SOME/IP as the SOA protocol. [less ▲]

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See detailUnlocking web archives through metadata, seed lists and derived data
Clavert, Frédéric UL; Schafer, Valerie UL

Scientific Conference (2022, June 01)

This presentation addresses the use, re-use, access and dissemination of data related to web archives. Web archives (Brügger, 2018) have been for several years in a hybrid position regarding access ... [more ▼]

This presentation addresses the use, re-use, access and dissemination of data related to web archives. Web archives (Brügger, 2018) have been for several years in a hybrid position regarding access, depending on the institutions that were preserving them. While Internet Archive has made its collections available online since 2001 through the Wayback Machine (but with limited features for scholars willing to conduct a distant reading based on data, WARC files, etc.), most national libraries only allowed an onsite access due to authors rights restrictions (and in some cases the frame of legal deposits), while starting to provide interesting metadata for research projects willing to explore them. However, the situation is currently evolving in the frame of several research projects that allow to access a vast amount of (international) metadata and datasets. Taking two research projects in progress as case studies, WARCnet and AWAC2, this paper aims to present the move towards the use of metadata and derived data related to huge collections of web archives of the COVID crisis. WARCnet (Web ARChive studies network researching web domains and events) is a network whose activities (funded by the Independent Research Fund Denmark | Humanities (grant no 9055-00005B)) run in 2020-2023. The networking activities are guided by overarching research questions, one of them being “How transnational events developed on the European web?” (and notably the COVID crisis which is explored in WG2 (https://cc.au.dk/en/warcnet/working-groups)). AWAC2 (Analysing Web Archives of the COVID Crisis through the IIPC Novel Coronavirus dataset) is a project part of the Archives Unleashed Cohort Program, that supports and facilitates research engagement with web archives. It aims to explore a unique collection of web material (https://archive-it.org/collections/13529) related to the pandemic, with contributions from over 30 members of IIPC (International Internet Preservation Consortium) as well as public nominations from over 100 individuals/institutions. May it be in terms of access or tools, both projects are currently exploring new methodologies based on broad datasets (i.e. 5,3 TB for the IIPC collection related to the COVID crisis; 9.4 GB and 8,738,751 lines for the CSV related to plain text webpages). Starting with the WARCnet project, the presentation will explain how its WG2 gathered and accessed several national European datasets of COVID web archives, their specificities as well as their heterogeneity, the first analysis conducted through a datathon on January- February 2021 (Aasman et al. 2021) and the limits and assets of such access. Within the AWAC2 project (2021-2022) the access to the international IIPC COVID collection, through Archive-It and through the cohort program developed by the Archives Unleashed Team (Netpreserve, 2021; Ruest et al., 2021), is then a new opportunity to access data through mediated interfaces (ARCH) and to go further into them. Here again the presentation will demonstrate new opportunities and show a few examples of the analysis conducted by the team. Both examples aim to present the way web archiving institutions, libraries and researchers are developing new ways of accessing and exploring web archives, while also increasing their value(s) (Schafer and Winters, 2021). References Aasman, S., Bingham, N., Brügger, N., de Wild, K., Gebeil S. & Schafer V. (2021). Chicken and Egg: Reporting from a Datathon Exploring Datasets of the COVID- 19 Special Collections, WARCnet paper, Aarhus, https://cc.au.dk/fileadmin/dac/Projekter/WARCnet/Aasman_et_al_Chicken_and_Egg.pdf Brügger, N. (2018). The Archived Web. Doing History in the Digital Age. Cambridge, MA: The MIT Press. IIPC (2021), A Retrospective with the Archives Unleashed Project, netpreserve blog, https://netpreserveblog.wordpress.com/2021/04/01/a-retrospective-with-the-archives-unleashed-project/ Ruest, N., Fritz, S., Deschamps, R. Lin, J. & Milligan, I. (2021) From archive to analysis: accessing web archives at scale through a cloud-based interface. International Journal of Digital Humanities, https://paperity.org/p/260049927/from-archive-to-analysis-accessing-web-archives-at-scale-through-a-cloud-based-interface Schafer V. & Winters J. (2021). The values of web archives, International Journal of Digital Humanities, 1-10, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8190571/ [less ▲]

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See detailFeasibility of Advanced Oxidation Processes as an upgrade for Microcontaminants removal at municipal Wastewater Treatment Plants
Salmeron Garcia, Irene UL; Nunez Tafalla, Paula UL; Venditti, Silvia UL et al

Scientific Conference (2022, June)

Benzotriazole, carbamazepine, clarithromycin and diclofenac have been identified as microcontaminants of concern in Luxembourgish wastewaters, thus the implementation of photo-Fenton processes at natural ... [more ▼]

Benzotriazole, carbamazepine, clarithromycin and diclofenac have been identified as microcontaminants of concern in Luxembourgish wastewaters, thus the implementation of photo-Fenton processes at natural pH has been proposed for their removal. In the present work, the effectiveness of a pilot scale photo-Fenton system (500W Medium Pressure) has been evaluated according to the reagent dosage and toxicity of the treated effluent. With this treatment, 80% degradation is achieved in 15 minutes even with 5 and 3 mg/L of iron (40 mg/L H2O2), but 5 mg/L can have a negative effect on the growth of Sorghum saccharatum in Phytotoxicity tests. In comparison UV-C/H2O2 (40W Low Pressure; 40 mg/L H2O2) process needs longer treatment time and generates degradation by-products causing a growth inhibition of Sorghum saccharatum. The combination of both lamps can lead to a better performance of the reagents allowing to reach the 80% target in less time and to reduce the dosage. [less ▲]

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See detailMulticultural conviviality in the context of active ageing in Luxembourg
Albert, Isabelle UL; Hoffmann, Martine; Vandenbosch, Petra et al

Scientific Conference (2022, June)

Luxembourg’s population has not only become more culturally diverse in the past years but is also growing older. Almost 20 per cent of the total population of Luxembourg is over 60 years old, of which one ... [more ▼]

Luxembourg’s population has not only become more culturally diverse in the past years but is also growing older. Almost 20 per cent of the total population of Luxembourg is over 60 years old, of which one third are non-Luxembourgers. Active ageing can make an important contribution to the quality of life of older people and promote social inclusion, whereas the feeling of not belonging can be a psychological barrier to participation in activities. This was the starting point of the PAN-VAL project on active ageing of Luxembourgers and non-Luxembourgers, which was funded by the Luxembourg Ministry of Family and Integration and carried out in collaboration between a team from the University of Luxembourg and GERO – Kompetenzzenter fir den Alter. A total of N = 1000 people over 50 (51% women, 49% men) participated in a nationally representative online and telephone survey, and a number of n = 39 in-depth qualitative interviews were carried out with participants from four selected municipalities in different parts of the Grand Duchy: Differdange in the south, Mersch in the centre and Ettelbrück and Clervaux in the north. Based on our quantitative data, we will first present a model on the relations between sense of belonging, social inclusion, loneliness and participation in social activities. Drawing on our qualitative interviews, we will further analyze how the participants describe the processes how they developed a sense of belonging to the places they live in through mundane encounters with people from their municipalities and neighborhoods. We will also explore, how older people experience conviviality with regard to the offers for active ageing, focusing in particular on barriers and facilitators for participation in such offers. Policy implications and lessons learnt about how to adapt social offers to the diverse needs of an increasingly heterogeneous target group will be discussed. [less ▲]

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See detailPrivate Authors, Hybrid Process, Public effects: The Evolutive Legal Nature of Technical Standards Referenced in EU Law
Gerardy, Marie UL

in Jokobs, Kai; Kin, Dong-hyu (Eds.) EURAS Proceedings 2022: Standardisation and Open Source (2022, June)

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See detailDie zweifache Rechtfertigung des ‚Bösewichts‘: Figurationen des Bösen bei Schiller
Kohns, Oliver UL

Scientific Conference (2022, June)

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See detailApproximating WCRT through the aggregation of short simulations with different initial conditions: application to TSN
Keller, Patrick UL; Navet, Nicolas UL

in 30th International Conference on Real-Time Networks and Systems (RTNS ’22) (2022, June)

Assessing traversal times is the main concern in the verification of embedded real-time networks. Schedulability analysis, as it provides firm guarantees, is the preferred technique for the designers of ... [more ▼]

Assessing traversal times is the main concern in the verification of embedded real-time networks. Schedulability analysis, as it provides firm guarantees, is the preferred technique for the designers of critical systems. There are however contexts where it is not economically or technically feasible to develop one, typically when the software and hardware components have not been designed with predictability in mind, e.g. as soon as TCP-based traffic is involved in network communication or when the hardware platform is too complex (e.g. heterogeneous System-on-Chips). In this paper, we study if it is possible to improve the ability of simulation to observe large traversal times, by running many short simulations with appropriately chosen simulation time and varying initial offsets of the stations on the network. The de-facto standard approach to assess maximal traversal times is to run a single long simulation with synchronized node start offsets and to use randomized node clock drifts inside an acceptable range. This approach is known to yield high traversal times but is not parallelizable. We propose an alternative approach consisting in splitting the simulation time over multiple shorter simulations with, optionally, randomized node start offsets. We evaluate the optimization potential of this simple approach on several realistic network configurations by comparing long simulations to aggregated short simulations, with and without synchronized node start offsets. We observe, considering all flows, that this allows a median improvement of up to 21.3% in terms of maximum traversal time observed, for the same simulation time budget. Additional randomization of the node start offsets showed further improvements of up to 4.8% in our experiments. Results from this line of work can be used to estimate the pessimism of schedulability analyses and verify systems for which no analysis is available. [less ▲]

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See detailHyaku: A Qualitative Negotiation-Through-Interaction Interface to Support Runners in Achieving Balanced Training Sessions
Restrepo, Juan; Vos, Steven; Verhagen, Evert et al

Scientific Conference (2022, June)

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See detailA 3D Indoor Localization Approach Based on Spherical Wave-front and Channel Spatial Geometry
Liu, Yuan UL; Wu, Linlong UL; Alaeekerahroodi, Mohammad UL et al

in Liu, Yuan; Wu, Linlong; Alaeekerahroodi, Mohammad (Eds.) et al 2022 IEEE 12th Sensor Array and Multichannel Signal Processing Workshop (SAM) (2022, June)

Because of the near-field nature of radio propagation, spherical wave-front and multipath effect are prominent in indoor scenarios, making localization even more difficult. In this paper, we propose a ... [more ▼]

Because of the near-field nature of radio propagation, spherical wave-front and multipath effect are prominent in indoor scenarios, making localization even more difficult. In this paper, we propose a three-dimensional (3D) indoor localization algorithm that takes these issues into account. Specifically, we first adopted a high-resolution channel parameter estimation method for path delays based on the Space-Alternating Generalized Expectation-maximization (SAGE), and then these path delays are adopted in the 3D localization principles based on the target-antenna geometry. The proposed algorithm is validated by numerical simulations, where the channel data is generated by the propagation graph (PG) to model the true wireless propagation closely in the testing scenarios. The results demonstrate that the proposed approach can deal with both point and non-point targets with 3D localization errors of less than 30 cm for 97% of the testing trails in a 10×20×3 m3 indoor space. [less ▲]

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See detailDesigning for Qualitative Interfaces: Experiences from Studio Education
Lockton, Dan; Lallemand, Carine UL; Menheere, Daphne

Scientific Conference (2022, June)

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See detailSemantic and Interactive Search in an Advanced Note-Taking App for Learning Material
Atashpendar, Aryobarzan UL; Grevisse, Christian UL; Botev, Jean UL et al

in Proceedings of the 24th International Conference on Human-Computer Interaction (HCI International) (2022, June)

Note-taking apps on tablets are increasingly becoming the go-to space for managing learning material as a student. In particular, digital note-taking presents certain advantages over traditional pen-and ... [more ▼]

Note-taking apps on tablets are increasingly becoming the go-to space for managing learning material as a student. In particular, digital note-taking presents certain advantages over traditional pen-and-paper approaches when it comes to organizing and retrieving a library of notes thanks to various search functionalities. This paper presents improvements to the classic textual-input-based search field, by introducing a semantic search that considers the meaning of a user’s search terms and an automatic question-answering process that extracts the answer to the user’s question from their notes for more efficient information retrieval. Additionally, visual methods for finding specific notes are proposed, which do not require the input of text by the user: through the integration of a semantic similarity metric, notes similar to a selected document can be displayed based on common topics. Furthermore, a fully interactive process allows one to search for notes by selecting different types of dynamically generated filters, thus eliminating the need for textual input. Finally, a graph-based visualization is explored for the search results, which clusters semantically similar notes closer together to relay additional information to the user besides the raw search results. [less ▲]

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See detailReal-Time Large Deformation Simulations Using Probabilistic Deep Learning Framework
Saurabh, Deshpande; Jakub, Lengiewicz; Stephane, Bordas

Scientific Conference (2022, June)

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See detailLuxemBERT: Simple and Practical Data Augmentation in Language Model Pre-Training for Luxembourgish
Lothritz, Cedric UL; Lebichot, Bertrand UL; Allix, Kevin UL et al

in Proceedings of the Language Resources and Evaluation Conference, 2022 (2022, June)

Pre-trained Language Models such as BERT have become ubiquitous in NLP where they have achieved state-of-the-art performance in most NLP tasks. While these models are readily available for English and ... [more ▼]

Pre-trained Language Models such as BERT have become ubiquitous in NLP where they have achieved state-of-the-art performance in most NLP tasks. While these models are readily available for English and other widely spoken languages, they remain scarce for low-resource languages such as Luxembourgish. In this paper, we present LuxemBERT, a BERT model for the Luxembourgish language that we create using the following approach: we augment the pre-training dataset by considering text data from a closely related language that we partially translate using a simple and straightforward method. We are then able to produce the LuxemBERT model, which we show to be effective for various NLP tasks: it outperforms a simple baseline built with the available Luxembourgish text data as well the multilingual mBERT model, which is currently the only option for transformer-based language models in Luxembourgish. Furthermore, we present datasets for various downstream NLP tasks that we created for this study and will make available to researchers on request. [less ▲]

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See detailRobust Approach for Urban Road Surface Extraction Using Mobile Laser Scanning Data
Nurunnabi, Abdul Awal Md UL; Teferle, Felix Norman UL; Lindenbergh, Roderik et al

in Robust Approach for Urban Road Surface Extraction Using Mobile Laser Scanning Data (2022, June)

Road surface extraction is crucial for 3D city analysis. Mobile laser scanning (MLS) is the most appropriate data acquisition system for the road environment because of its efficient vehicle-based on-road ... [more ▼]

Road surface extraction is crucial for 3D city analysis. Mobile laser scanning (MLS) is the most appropriate data acquisition system for the road environment because of its efficient vehicle-based on-road scanning opportunity. Many methods are available for road pavement, curb and roadside way extraction. Most of them use classical approaches that do not mitigate problems caused by the presence of noise and outliers. In practice, however, laser scanning point clouds are not free from noise and outliers, and it is apparent that the presence of a very small portion of outliers and noise can produce unreliable and non-robust results. A road surface usually consists of three key parts: road pavement, curb and roadside way. This paper investigates the problem of road surface extraction in the presence of noise and outliers, and proposes a robust algorithm for road pavement, curb, road divider/islands, and roadside way extraction using MLS point clouds. The proposed algorithm employs robust statistical approaches to remove the consequences of the presence of noise and outliers. It consists of five sequential steps for road ground and non-ground surface separation, and road related components determination. Demonstration on two different MLS data sets shows that the new algorithm is efficient for road surface extraction and for classifying road pavement, curb, road divider/island and roadside way. The success can be rated in one experiment in this paper, where we extract curb points; the results achieve 97.28%, 100% and 0.986 of precision, recall and Matthews correlation coefficient, respectively. [less ▲]

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See detailRelative State Estimation for LEO Formations with Large Inter-satellite Distances Using Single-Frequency GNSS Receivers
Mahfouz, Ahmed UL; Menzio, Davide; Dalla Vedova, Florio et al

Scientific Conference (2022, June)

Relative baseline estimation is an integral part of satellite formation flying missions. GNSS-based relativepositioning has been a dominating technology for formation missions in LEO, where very precise ... [more ▼]

Relative baseline estimation is an integral part of satellite formation flying missions. GNSS-based relativepositioning has been a dominating technology for formation missions in LEO, where very precise estimatescould be obtained for formations with small inter-satellite distances (1 − 10 km). Larger baselines betweenthe satellites (> 10 km) pose the problem of considerable differences in the ionospheric delays experiencedby the signals received by each receiver. This problem could be mitigated by using precise ionospheric-freecombinations that could only be obtained by dual-frequency receivers, which is not a cost-efficient optionfor modern low-cost miniature missions. In this paper, the problem of relative baseline vector estimation isaddressed for formation missions with large inter-satellite distances equipped with single-frequency receivers.The problem is approached using the space-proven relatively simple Extended Kalman Filter with anadvantageous setting for the observation vector [less ▲]

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See detailReal-time large deformations: A probabilistic deep learning approach
Deshpande, Saurabh UL; Lengiewicz, Jakub UL; Bordas, Stéphane UL

in The 8th European Congress on Computational Methods in Applied Sciences and Engineering (2022, June)

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See detailFormation design of an inter-satellite link demonstration mission
Menzio, Davide; Mahfouz, Ahmed UL; Dalla Vedova et al

Scientific Conference (2022, June)

The problem of secular growth of the inter-satellite induced by the J2 perturbations has been widely exploredin the literature. In this paper, we study the influence of altitude and initial mean anomaly ... [more ▼]

The problem of secular growth of the inter-satellite induced by the J2 perturbations has been widely exploredin the literature. In this paper, we study the influence of altitude and initial mean anomaly of the chief on theinter-satellite distance growth in a classical trailing formation. Mean elements are converted into osculatingones and then in Cartesian coordinates that are propagated together in the ECI frame. Preliminary resultsshows that zonal harmonics are responsible for a steep distance drift when the formation is inserted inthe vicinity of ±45 and ±135 degrees of mean anomaly in a polar orbit. Distance-invariant solutions aredetermined in term of the mean anomaly and characterized in terms of the difference between the averagerelative distance and the initial one and of the amplitude of the osculating distance. Finally, after the inter-satellite distance has grown to an unacceptable level, the electric thruster onboard of the deputy spacecraftis leveraged in order to reset the deputy’s orbit to the distance invariant mean elements. A finite-time LinearQuadratic Regulator (FTLQR) is designed and validated within a high-fidely dynamics framework [less ▲]

See detailKonzept, Methodik und Perspektiven eines digitalen historischen Stadtatlas - das Beispiel Luxemburg
Uhrmacher, Martin UL

Scientific Conference (2022, June)

The historical atlas of the city of Luxembourg has been accessible on the internet since 2019. Since then, it has been continuously expanded, revised and improved, both technically and in terms of content ... [more ▼]

The historical atlas of the city of Luxembourg has been accessible on the internet since 2019. Since then, it has been continuously expanded, revised and improved, both technically and in terms of content. Users currently have the opportunity to view a large number of historical old maps and aerial photographs from Luxembourg archives for the period between 1560 and 2017 at zoom levels of their choice and to compare them with each other on transparent layers, precisely fitting one above the other. In addition, historical photos and views as well as explanatory texts on the city's history and on selected buildings or other infrastructure elements can be displayed. In order to realise the advantages of a web publication in the best possible way, the Luxatlas is based on open source software. This enables the development of customised WebGIS applications for the specific requirements of the project.In addition to the project presentation, the presentation will also highlight the methodological and source-critical challenges and put them up for discussion. [less ▲]

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See detailMixed RIS-Relay NOMA-Based RF-UOWC systems
Elsayed, Mohamed; Samir, Ahmed; El-Banna, Ahmad A.Aziz et al

Poster (2022, June)

Reconfigurable intelligent surface (RIS), nonorthogonal multiple access (NOMA), and underwater optical wireless communication (UOWC) are paradigms of technologies that drive the development of ... [more ▼]

Reconfigurable intelligent surface (RIS), nonorthogonal multiple access (NOMA), and underwater optical wireless communication (UOWC) are paradigms of technologies that drive the development of communications nowadays. In this paper, we investigate the performance of a NOMA-based RISassisted hybrid radio frequency (RF)-UOWC system. Due to the interruption of the direct link between the base station and the ship floating on the surface of the water, communication will be carried out via an RIS fixed to an intermediate building. The ship works as a relay that redirects the received signal to two underwater destinations simultaneously. In this paper, we provide new analytical expressions for the outage probability (OP), asymptotic analyses of the OP, and diversity order (D) to gain insights into the system performance. The results showed that the diversity order depends on the UOWC receiver detection technique. In the end, we illustrated that the NOMA-based RISassisted system significantly improves the outage performance of hybrid RF-UWOC systems over a benchmark systems. [less ▲]

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See detailResampling methods for a reliable validation set in deep learning based point cloud classification
Nurunnabi, Abdul Awal Md UL; Teferle, Felix Norman UL

in Resampling methods for a reliable validation set in deep learning based point cloud classification (2022, June)

A validation data set plays a pivotal role in tweaking a machine learning model trained in a supervised manner. Many existing algorithms select a part of available data by using random sampling to produce ... [more ▼]

A validation data set plays a pivotal role in tweaking a machine learning model trained in a supervised manner. Many existing algorithms select a part of available data by using random sampling to produce a validation set. However, this approach can be prone to overfitting. One should follow careful data splitting to have reliable training and validation sets that can produce a generalized model with a good performance for the unseen (test) data. Data splitting based on resampling techniques involves repeatedly drawing samples from the available data. Hence, resampling methods can give better generalization power to a model, because they can produce and use many training and/or validation sets. These techniques are computationally expensive, but with increasingly available high-performance computing facilities, one can exploit them. Though a multitude of resampling methods exist, investigation of their influence on the generality of deep learning (DL) algorithms is limited due to its non-linear black-box nature. This paper contributes by: (1) investigating the generalization capability of the four most popular resampling methods: k-fold cross-validation (k-CV), repeated k-CV (Rk-CV), Monte Carlo CV (MC-CV) and bootstrap for creating training and validation data sets used for developing, training and validating DL based point cloud classifiers (e.g., PointNet; Qi et al., 2017a), (2) justifying Mean Square Error (MSE) as a statistically consistent estimator, and (3) exploring the use of MSE as a reliable performance metric for supervised DL. Experiments in this paper are performed on both synthetic and real-world aerial laser scanning (ALS) point clouds. [less ▲]

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See detailEvaluating Mobility Service Providers’ Strategies in an Activity-Based Supernetwork
Bandiera, Claudia UL; Connors, Richard UL; Viti, Francesco UL

Scientific Conference (2022, June)

A Mathematical Problem with Equilibrium Constraints (MPEC) is formulated to capture the relationships between multiple Mobility Service Providers (MSPs) and the users of a multimodal transport network ... [more ▼]

A Mathematical Problem with Equilibrium Constraints (MPEC) is formulated to capture the relationships between multiple Mobility Service Providers (MSPs) and the users of a multimodal transport network. The network supply structure is represented as a supernetwork where users’ daily activity chains are represented sequentially and their modal choices to reach different destinations are based on the mobility services active in each connection. At the upper level, a profit maximization formulation is introduced to describe MSPs’ behaviour. At the lower level, groups of users choose the routes with the lowest cost, according to Wardrop’s first equilibrium principle. Due to non-separable interactions between supernetwork links, the equilibrium conditions defining users travel behaviour are written as Variational Inequality (VI). Finally, a numerical example is presented in order to show the characteristics of the model when car-sharing, bus and private car are available in the network. [less ▲]

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See detailComparison of UVC and Solar-based Processes for the Simultaneous Removal of Microcontaminants and Microorganism from Urban Wastewater Effluents I.
Salmeron Garcia, Irene UL; Sánchez-Montes, Isaac; Ruiz-Delgado, Ana et al

Scientific Conference (2022, June)

Currently, the presence of microcontaminats (MCs) and pathogens in secondary municipal wastewater treatment plant effluents entails a challenge to be addressed before water discharge or reuse. In this ... [more ▼]

Currently, the presence of microcontaminats (MCs) and pathogens in secondary municipal wastewater treatment plant effluents entails a challenge to be addressed before water discharge or reuse. In this work UVC (UVC/S2O82-, UVC/H2O2) and solar-based processes (solar/S2O82- and solar/H2O2) are proposed as tertiary treatments for the simultaneous removal of both, MCs and pathogens, comparing their efficiency aiming to find the most suitable solution. The microorganisms studied were Escherichia coli, Enterococcus faecalis and Salmonella enteritidis in a concentration of 103 CFU mL-1 each and a mixture of 6 MCs (acetaminophen, caffeine, carbamazepine, trimethoprim, sulfamethoxazole and diclofenac) each at 100 μg L-1 of initial concentration, using simulated wastewater treatment plant effluent as water matrix. The concentrations of oxidants studied were 25 and 50 mg L-1 of each, respectively. Results revealed that UVC/H2O2 at 25 mg L-1 presented the most satisfactory solution considering treatment time and addition of reagents for complete inactivation of target pathogens and 80% removal of the sum of MCs. [less ▲]

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See detailA Variant of Concurrent Constraint Programming on GPU
Talbot, Pierre UL; Pinel, Frederic UL; Bouvry, Pascal UL

in Proceedings of the AAAI Conference on Artificial Intelligence (2022, June), 36(4), 3830-3839

The number of cores on graphical computing units (GPUs) is reaching thousands nowadays, whereas the clock speed of processors stagnates. Unfortunately, constraint programming solvers do not take advantage ... [more ▼]

The number of cores on graphical computing units (GPUs) is reaching thousands nowadays, whereas the clock speed of processors stagnates. Unfortunately, constraint programming solvers do not take advantage yet of GPU parallelism. One reason is that constraint solvers were primarily designed within the mental frame of sequential computation. To solve this issue, we take a step back and contribute to a simple, intrinsically parallel, lock-free and formally correct programming language based on concurrent constraint programming. We then re-examine parallel constraint solving on GPUs within this formalism, and develop Turbo, a simple constraint solver entirely programmed on GPUs. Turbo validates the correctness of our approach and compares positively to a parallel CPU-based solver. [less ▲]

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See detailTheme Track - Valuing the qualitative in design and data
Lockton, Dan; Lallemand, Carine UL; Menheere, Daphne et al

in Proceedings of DRS 2022 (2022, June)

The DRS 2022 track ‘Valuing the Qualitative in Design and Data’ features eleven accepted papers on topics including visualisation and physicalisation of qualitative data, the use of materials in this ... [more ▼]

The DRS 2022 track ‘Valuing the Qualitative in Design and Data’ features eleven accepted papers on topics including visualisation and physicalisation of qualitative data, the use of materials in this context, practical applications in design and education, and applications in personal informatics. In this editorial, the track chairs introduce the track, and the reasoning behind it, together with a short introduction to the papers. [less ▲]

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See detailMATERIAL MODELLING AND FINITE ELEMENT ANALYSIS IN METAL ADDITIVE MANUFACTURING
Mashhood, Muhammad UL; Baroli, Davide; Wyart, Eric et al

Poster (2022, May 31)

The additive manufacturing (AM) is competent method for the manufacturing of complex metal parts with wider process flexibility. During manufacturing, the metal part repetitively undergoes heating and ... [more ▼]

The additive manufacturing (AM) is competent method for the manufacturing of complex metal parts with wider process flexibility. During manufacturing, the metal part repetitively undergoes heating and cooling under the influence of laser passes and ambient conditions respectively. In turn, the material experiences the thermal strain and residual stress. The aim of the work is to predict them using certain material model. Where the solidified metal part from melt-pool is considered in current analysis. For numerical simulation, Finite Element Method (FEM) is chosen. The heat equation is first solved for thermal profile of AM Process. Afterwards, the structural analysis is performed with such thermal load. The non linear constitutive material model is utilised. For concerned material model, the temperature dependence upon the material properties is also implemented. The resulting Finite Element Analysis (FEA) platform offers the macro-scale thermal solution and the prediction of resulting plastic distortion in material. This prediction however has become more accurate when the variable material property, depending upon the temperature of analysis zone, is introduced. [less ▲]

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See detailAnalysis of GNSS sensed slant wet delay during severe weather events in central Europe
Hunegnaw, Addisu UL; Duman, Hüseyin; Elgered, Gunnar et al

Scientific Conference (2022, May 26)

Over the last few decades, anthropogenic greenhouse gas emissions have increased the frequency of climatological anomalies such as temperature, precipitation, and evapotranspiration. It is noticed that ... [more ▼]

Over the last few decades, anthropogenic greenhouse gas emissions have increased the frequency of climatological anomalies such as temperature, precipitation, and evapotranspiration. It is noticed that the frequency and severity of the intense precipitation signify a greater susceptibility to flash flooding. Flash flooding continues to be a major threat to European cities, with devastating mortality and considerable damage to urban infrastructure. As a result, accurate forecasting of future extreme precipitation events is critical for natural hazard mitigation. A network of ground-based GNSS receivers enables the measurement of integrated water vapour along slant pathways providing three-dimensional water vapour distributions. This study aims to demonstrate how GNSS sensing of the troposphere can be used to monitor the rapid and extreme weather events that occurred in central Europe in June 2013 and resulted in flash floods and property damage. We recovered one-way slant wet delay (SWD) by adding GNSS post-fit phase residuals, representing the troposphere's higher-order inhomogeneity. Nonetheless, noise in the GNSS phase observable caused by site-specific multipath can significantly affect the SWD from individual satellites. To overcome the problem, we employ a suitable averaging strategy for stacking post-fit phase residuals obtained from the PPP processing strategy to generate site-specific multipath corrections maps (MPS). The spatial stacking is carried out in congruent cells with an optimal resolution in elevation and azimuth at the local horizon but with decreasing azimuth resolution as the elevation angle increases. This permits an approximately equal number of observations allocated to each cell. The spatio-temporal fluctuations in the SWD as measured by GNSS closely mirrored the moisture field associated with severe weather events in central Europe, i.e., a brief rise prior to the main rain events, followed by a rapid decline once the storms passed. Furthermore, we validated the one-way SWD between ground-based water-vapour radiometry (WVR) and GNSS-derived SWD for different elevation angles. [less ▲]

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See detailGuiding Refugees Through European Bureaucracy: Designing a Trustworthy Mobile App for Document Management
Amard, Alexandre UL; Höß, Alexandra UL; Roth, Tamara UL et al

in Drechsler, A.; Gerber, A.; Hevner, A. (Eds.) The Transdisciplinary Reach of Design Science Research. DESRIST 2022 (2022, May 25)

After being granted asylum in European countries, refugees need to go through a multitude of administrative processes before they can participate in society. However, these processes are often challenging ... [more ▼]

After being granted asylum in European countries, refugees need to go through a multitude of administrative processes before they can participate in society. However, these processes are often challenging, as refugees struggle to understand them, lack instructions for managing paperwork, and do not possess the required language skills. Prior research emphasizes the role of information and communication technologies to simplify and enable refugee-friendly administrative processes. However, recent research and existing applications mainly focus on information retrieval and do not offer assistance for understanding official letters, completing administrative forms, and managing corresponding documents. Furthermore, refugees are often reluctant to use existing applications as they do not trust their host country’s governments and public authorities. In this research, we aim to address this functional and trust gap. We follow a design science research approach to develop a design for a refugee-centric and trustworthy mobile application that assists refugees along administrative processes. In doing so, we identify three design principles that may guide the development of such applications for refugees. [less ▲]

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See detailA Cybersecurity Incident: Who You Gonna Call?
Schmitz, Sandra UL

Scientific Conference (2022, May 25)

Detailed reference viewed: 33 (1 UL)
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See detail“Use”: When personas become real users…
Clavert, Frédéric UL; Schafer, Valerie UL

Scientific Conference (2022, May 24)

Building upon our experience with ARCH, our study related to the IIPC Novel Coronavirus collection, as well as upon the first months of research we conducted as a cohort team in the Archives Unleashed ... [more ▼]

Building upon our experience with ARCH, our study related to the IIPC Novel Coronavirus collection, as well as upon the first months of research we conducted as a cohort team in the Archives Unleashed Project, we will provide feedback related to users’ needs and achievements. Ian Milligan distinguished in his paper “You shouldn’t Need to be a Web Historian to Use Web Archives: Lowering Barriers to Access Through Community and Infrastructure” (WARCnet paper, Aarhus, 2020), three personas: a computational humanist, a digital humanist, and a conventional historian. As an heterogeneous team, mirroring in some ways the personas distinguished by Ian Milligan, we will underline the successes and failures we experienced, the technical layers and levels we unfolded, our experience of collective work which also needs to take interdisciplinarity and heterogeneity (of technical skills, interests, availability, digital literacy) into account, the value of mentorship and our iterative process with data and research questions. We will finally shortly discuss the many pros and few cons in lowering barriers to access web archives (e.g. How to make access easiest without hiding the complexity of web archives?). [less ▲]

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See detailTriggerZoo: A Dataset of Android Applications Automatically Infected with Logic Bombs
Samhi, Jordan UL; Bissyande, Tegawendé François D Assise UL; Klein, Jacques UL

in 19th International Conference on Mining Software Repositories, Data Showcase, (MSR 2022) (2022, May 23)

Many Android apps analyzers rely, among other techniques, on dynamic analysis to monitor their runtime behavior and detect potential security threats. However, malicious developers use subtle, though ... [more ▼]

Many Android apps analyzers rely, among other techniques, on dynamic analysis to monitor their runtime behavior and detect potential security threats. However, malicious developers use subtle, though efficient, techniques to bypass dynamic analyzers. Logic bombs are examples of popular techniques where the malicious code is triggered only under specific circumstances, challenging comprehensive dynamic analyses. The research community has proposed various approaches and tools to detect logic bombs. Unfortunately, rigorous assessment and fair comparison of state-of-the-art techniques are impossible due to the lack of ground truth. In this paper, we present TriggerZoo, a new dataset of 406 Android apps containing logic bombs and benign trigger-based behavior that we release only to the research community using authenticated API. These apps are real-world apps from Google Play that have been automatically infected by our tool AndroBomb. The injected pieces of code implementing the logic bombs cover a large pallet of realistic logic bomb types that we have manually characterized from a set of real logic bombs. Researchers can exploit this dataset as ground truth to assess their approaches and provide comparisons against other tools. [less ▲]

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See detailGraphCode2Vec: generic code embedding via lexical and program dependence analyses
Ma, Wei UL; Zhao, Mengjie; Soremekun, Ezekiel UL et al

in Proceedings of the 19th International Conference on Mining Software Repositories (2022, May 22)

Code embedding is a keystone in the application of machine learn- ing on several Software Engineering (SE) tasks. To effectively support a plethora of SE tasks, the embedding needs to capture program ... [more ▼]

Code embedding is a keystone in the application of machine learn- ing on several Software Engineering (SE) tasks. To effectively support a plethora of SE tasks, the embedding needs to capture program syntax and semantics in a way that is generic. To this end, we propose the first self-supervised pre-training approach (called GraphCode2Vec) which produces task-agnostic embedding of lexical and program dependence features. GraphCode2Vec achieves this via a synergistic combination of code analysis and Graph Neural Networks. GraphCode2Vec is generic, it allows pre-training, and it is applicable to several SE downstream tasks. We evaluate the effectiveness of GraphCode2Vec on four (4) tasks (method name prediction, solution classification, mutation testing and overfitted patch classification), and compare it with four (4) similarly generic code embedding baselines (Code2Seq, Code2Vec, CodeBERT, Graph- CodeBERT) and seven (7) task-specific, learning-based methods. In particular, GraphCode2Vec is more effective than both generic and task-specific learning-based baselines. It is also complementary and comparable to GraphCodeBERT (a larger and more complex model). We also demonstrate through a probing and ablation study that GraphCode2Vec learns lexical and program dependence features and that self-supervised pre-training improves effectiveness. [less ▲]

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See detailJuCify: A Step Towards Android Code Unification for Enhanced Static Analysis
Samhi, Jordan UL; Gao, Jun UL; Daoudi, Nadia UL et al

in 44th International Conference on Software Engineering (ICSE 2022) (2022, May 21)

Native code is now commonplace within Android app packages where it co-exists and interacts with Dex bytecode through the Java Native Interface to deliver rich app functionalities. Yet, state-of-the-art ... [more ▼]

Native code is now commonplace within Android app packages where it co-exists and interacts with Dex bytecode through the Java Native Interface to deliver rich app functionalities. Yet, state-of-the-art static analysis approaches have mostly overlooked the presence of such native code, which, however, may implement some key sensitive, or even malicious, parts of the app behavior. This limitation of the state of the art is a severe threat to validity in a large range of static analyses that do not have a complete view of the executable code in apps. To address this issue, we propose a new advance in the ambitious research direction of building a unified model of all code in Android apps. The JuCify approach presented in this paper is a significant step towards such a model, where we extract and merge call graphs of native code and bytecode to make the final model readily-usable by a common Android analysis framework: in our implementation, JuCify builds on the Soot internal intermediate representation. We performed empirical investigations to highlight how, without the unified model, a significant amount of Java methods called from the native code are ``unreachable'' in apps' call-graphs, both in goodware and malware. Using JuCify, we were able to enable static analyzers to reveal cases where malware relied on native code to hide invocation of payment library code or of other sensitive code in the Android framework. Additionally, JuCify's model enables state-of-the-art tools to achieve better precision and recall in detecting data leaks through native code. Finally, we show that by using JuCify we can find sensitive data leaks that pass through native code. [less ▲]

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See detailDifuzer: Uncovering Suspicious Hidden Sensitive Operations in Android Apps
Samhi, Jordan UL; Li, Li; Bissyande, Tegawendé François D Assise UL et al

in 44th International Conference on Software Engineering (ICSE 2022) (2022, May 21)

One prominent tactic used to keep malicious behavior from being detected during dynamic test campaigns is logic bombs, where malicious operations are triggered only when specific conditions are satisfied ... [more ▼]

One prominent tactic used to keep malicious behavior from being detected during dynamic test campaigns is logic bombs, where malicious operations are triggered only when specific conditions are satisfied. Defusing logic bombs remains an unsolved problem in the literature. In this work, we propose to investigate Suspicious Hidden Sensitive Operations (SHSOs) as a step towards triaging logic bombs. To that end, we develop a novel hybrid approach that combines static analysis and anomaly detection techniques to uncover SHSOs, which we predict as likely implementations of logic bombs. Concretely, Difuzer identifies SHSO entry-points using an instrumentation engine and an inter-procedural data-flow analysis. Then, it extracts trigger-specific features to characterize SHSOs and leverages One-Class SVM to implement an unsupervised learning model for detecting abnormal triggers. We evaluate our prototype and show that it yields a precision of 99.02% to detect SHSOs among which 29.7% are logic bombs. Difuzer outperforms the state-of-the-art in revealing more logic bombs while yielding less false positives in about one order of magnitude less time. All our artifacts are released to the community. [less ▲]

Detailed reference viewed: 66 (9 UL)
See detailLes archives du Web, des sources aux données
Schafer, Valerie UL

Scientific Conference (2022, May 20)

This keynote during Humanistica 2022 aimed to retrace 15 years of evolution of web archiving and web archives' studies. It also presented some research projects like the current Hivi, WARCnet and AWAC2 ... [more ▼]

This keynote during Humanistica 2022 aimed to retrace 15 years of evolution of web archiving and web archives' studies. It also presented some research projects like the current Hivi, WARCnet and AWAC2 projects. [less ▲]

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See detailL'émission de radio "100 Jahre Ostbelgien"
Brüll, Christoph UL; Fickers, Andreas UL

Scientific Conference (2022, May 20)

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See detailRobust and Provable Guarantees for Sparse Random Embeddings
Skorski, Maciej; Temperoni, Alessandro UL; Theobald, Martin UL

in Advances in Knowledge Discovery and Data Mining - 26th Pacific-Asia Conference, PAKDD 2022, Chengdu, China, May 16-19, 2022, Proceedings, Part II. (2022, May 18)

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See detailDie unfreien Befreiten. Über die lange Heimkehr der sowjetischen ZwangsarbeiterInnen aus Luxemburg.
Ganschow, Inna UL

Scientific Conference (2022, May 17)

Inna Ganschow untersucht in ihrem Vortrag die verschiedenen Typen totaler Institutionen im Sinne Erving Goffmans auf dem Weg von ZwangsarbeiterInnen aus der Sowjetunion nach Luxemburg und zurück. Von den ... [more ▼]

Inna Ganschow untersucht in ihrem Vortrag die verschiedenen Typen totaler Institutionen im Sinne Erving Goffmans auf dem Weg von ZwangsarbeiterInnen aus der Sowjetunion nach Luxemburg und zurück. Von den nationalsozialistischen Durchgangs- und Kriegsgefangenenlagern über die luxemburgischen Werk- und Ostarbeiterlager bis hin zu den sowjetischen Sammel- und Filterlagern endete die lange Reise nach Hause oft nach einigen Monaten oder Jahren erneut in einem Lager oder einer Zwangsansiedlung. Die Repatriierung junger ukrainischer, weißrussischer und russischer Frauen wird anhand von erhaltenen Dokumenten aus erster Hand, verschiedenen Lager- und Betriebsunterlagen sowie Augenzeugenberichten rekonstruiert. Die Rückführung wird im Hinblick auf ihre Funktion analysiert, die eine Bestrafung, eine Belohnung oder ein Schutz sein konnte. [less ▲]

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See detailMEC-assisted Dynamic Geofencing for 5G-enabled UAV
Bera, Abhishek UL; Sanchez-Cuevas, Pedro J.; Olivares-Mendez, Miguel Angel

in IEEE Wireless Communications and Networking Conference (2022, May 16)

5G-enabled UAV-based services have become popular for civilian applications. At the same time, certain no-fly zones will be highly dynamic, e.g. accident areas, large outdoor public events, VIP convoys ... [more ▼]

5G-enabled UAV-based services have become popular for civilian applications. At the same time, certain no-fly zones will be highly dynamic, e.g. accident areas, large outdoor public events, VIP convoys etc. An appropriate geofencing algorithm is required to avoid the no-fly zone in such scenarios. However, it is challenging to execute a high computing process such as a geofencing algorithm for a resource constraint UAV. This paper proposes an architecture and a geofencing algorithm for 5G-enabled UAV using Mobile Edge Computing (MEC). Also, the 5G-enabled UAV must fly within the coverage area during a mission. Hence, there must be an optimal trade-off between 5G coverage and distance to travel to design a new trajectory for a 5G-enabled UAV. To this end, we propose a cost minimization problem to generate a new trajectory while a no-fly zone exists. Specifically, we design a cost function considering 5G coverage and the velocity of the UAV. Then, we propose a geofencing algorithm running at the MEC by adopting the fast marching method (FMM) to generate a new trajectory for the UAV. Finally, a numerical example shows how the proposed geofencing algorithm generates an optimal trajectory for a UAV to avoid a dynamically created no-fly zone while on the mission. [less ▲]

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See detailTraffic Steering for eMBB and uRLLC Coexistence in Open Radio Access Networks
Kavehmadavani, Fatemeh UL; Vu, Thang Xuan UL; Chatzinotas, Symeon UL et al

in Traffic Steering for eMBB and uRLLC Coexistence in Open Radio Access Networks (2022, May 16)

Existing radio access network (RAN) architectures are lack of sufficient openness, flexibility, and intelligence to meet the diverse demands of emerging services in beyond 5G and 6G wireless networks ... [more ▼]

Existing radio access network (RAN) architectures are lack of sufficient openness, flexibility, and intelligence to meet the diverse demands of emerging services in beyond 5G and 6G wireless networks, including enhanced mobile broadband (eMBB) and ultra-reliable and low-latency (uRLLC). Open RAN (ORAN) is a promising paradigm that allows building a virtualized and intelligent architecture. In this paper, we focus on traffic steering (TS) scheme based on multi-connectivity (MC) and network slicing (NS) techniques to efficiently allocate heterogeneous network resources in “NextG” cellular networks. We formulate the RAN resource allocation problem to simultaneously maximize the weighted sum eMBB throughput and minimize the worst-user uRLLC latency subject to QoS requirements, and orthogonality, power, and limited fronthaul constraints. Since the formulated problem is categorized as a mixed integer … [less ▲]

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See detailLuxembourg – navigating the transition to the knowledge economy. A historical perspective
Danescu, Elena UL

Scientific Conference (2022, May 13)

Luxembourg is a multicultural, multilingual and cross-border area par excellence that has always sought to maintain an openness to its neighbours, both for reasons of security and to give itself access to ... [more ▼]

Luxembourg is a multicultural, multilingual and cross-border area par excellence that has always sought to maintain an openness to its neighbours, both for reasons of security and to give itself access to larger markets. Despite its small geographical area, limited workforce and lack of natural resources, Luxembourg is currently first out of 196 countries worldwide in terms of GDP/capita (with 114 370 €/capita, representing 260% of the EU average).Thanks to a long-term strategic vision, political and institutional innovation and structural changes implemented in economy throughout the 20th century, the once bipolar agricultural/industrial society has become a competitive society based largely on knowledge-intensive services and centred on the financial sector, characterised by high-performing human capital, political stability, prosperity and a strong welfare system.Taking this observation as a starting point, adopting a comparative and interdisciplinary perspective and drawing on a wide range of European and international archive and institutional sources, the paper sets out to address the following research questions: what are the factors of change and the major challenges facing Luxembourg in the digital transition? What institutions and governance is it using to tackle these challenges? What are the risks, benefits and opportunities of this transformation over the long term? What are the country’s strengths in terms of competitiveness, and what are the weaknesses that might jeopardise its comparative advantages? What is the impact of digitalisation on the public sector and on the government’s links with business and the public at large? [less ▲]

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See detailThe NIS 2.0 Directive - Lessons learnt or lagging behind? A legal perspective
Schmitz, Sandra UL

Scientific Conference (2022, May 10)

Detailed reference viewed: 183 (0 UL)
See detailTable ronde : Quel avenir pour la Revue Belge d'Histoire contemporaine ?
Auwers, Michael; Dubois, Sébastien; Tyssens et al

Scientific Conference (2022, May 09)

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See detailScanning the Past: A 3D Model of Trausch's Library
Teferle, Felix Norman UL; Wieneke, Lars UL; Parvaz, Shahoriar UL et al

Scientific Conference (2022, May 05)

Today, modern geospatial technologies and methods are widely used in combination with the documentation and preservation of objects of importance to cultural heritage. In this setting, archeologists and ... [more ▼]

Today, modern geospatial technologies and methods are widely used in combination with the documentation and preservation of objects of importance to cultural heritage. In this setting, archeologists and historians alike benefit from the rapid technological developments over the past decades, which have resulted in instrumentation that allows the capture of real objects and the generation of accurate and precise three-dimensional (3D) digital representations, i.e. models, from these sensed data. Here, the object of interest is the villa of the late historian Professor Gilbert Trausch with its library, for which a virtual library should be created for the general public. The building is an 19th century townhouse located on Limpertsberg in the City of Luxembourg and contains a cellar, three floors as well as a loft. Of particular interest were the cellar, stair cases, the first (the location of Professor Trausch’s office) and second floors as most of the bookshelves are situated there. In line with state-of-the-art approaches for 3D building modelling, a broad spectrum of modern geospatial technologies including classical surveying, Global Navigation Satellite System (GNSS), digital close-range photogrammetry and terrestrial laser scanning were employed to capture the Villa Trausch and its 33 bookshelves, i.e. Trausch’s Library, in all its details, while providing all data in one homogeneous coordinate system. Models and more photo-realistic visualizations of the exterior and interior have been obtained using, e.g., indoor images captured during the scanning. These allowed us to explore different virtual reality (VR) pathways employed by the gaming industry, for the generation of a first VR experience of the building in the sense of a digital museum. Currently solutions for the development of a public virtual library using commercial providers are investigated. [less ▲]

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See detailThe Best Space Resource is the One You Can Catch and Reuse
Hubert Delisle, Maxime UL; Yalcin, Baris Can UL; Martinez Luna, Carol UL et al

Poster (2022, May 03)

From the beginning of space exploration more than 60 years ago, only a few in-orbit objects have been removed or reused. In fact, the Kessler Syndrome states that the number of space debris is growing ... [more ▼]

From the beginning of space exploration more than 60 years ago, only a few in-orbit objects have been removed or reused. In fact, the Kessler Syndrome states that the number of space debris is growing exponentially [1], leaving unused uncooperative objects orbiting at high velocities at several altitudes, especially in Low-Earth Orbit (LEO). In other words, the situation brings up two main critical issues: not only a non-sustainable space environment for satellite missions, with orbit saturation, but also the creation of an unsafe place for future human-related space exploration missions. Active Debris Removal is a possible solution for tackling the problem of space debris. Despite being extremely challenging, catching autonomously and harmlessly an uncooperative object tumbling at high velocity demands reliability, compliance and robustness. The fruitful collaboration between industry and academia (Spacety Luxembourg - SnT-SpaceR research group at the University of Luxembourg), is leading to the cutting-edge concept of a two-step capturing mechanism. A first ‘soft capture’ ensures that the debris is received softly while dampening any vibrations generated during the contact. Then, a ‘hard capture’ secures the debris so that it would be deorbited or safely shipped for other orbits or space stations for reuse. Capturing debris and decommissioned in-orbit objects for recycling or reusing can be the anchor of new opportunities in space and beyond. Most of the objects in orbit can have aluminum parts, besides other beneficial materials among their subsystems, such as solar panels, antennas or electronics which can be reused. To maximize space resources reusability, it is important to not harm the target. Capturing solutions such as harpoons or rigid interfaces can cause damage to the targets, resulting in hardly exploitable resources, and even more smaller debris tumbling in orbit [2]. An application of the proposed capturing technology would be to collect defunct satellites and debris, thus contributing to a more sustainable environment in space, gathering those on a possible recycling orbit or to any future Space Station for recycling. References [1] Drmola J. and Hubik T., Kessler Syndrome: System Dynamics Model (2018), In-Space Policy, 44–45, 29–39 [2] Zhao P., Liu J. and Wu C., Survey on Research and Development of On-Orbit Active Debris Removal Methods (2020), Sci China Tech Sci, 63: 2188–2210 [less ▲]

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See detailExploring NVIDIA Omniverse for Future Space Resources Missions
Li, Xiao UL; Yalcin, Baris Can UL; Christidi-Loumpasefski, Olga-Orsalia UL et al

Poster (2022, May 03)

The resources of space offer a means to enable sustainable exploration of the Moon and Solar System beyond, thus developing space resource technologies is becoming a major topic for space-related activity ... [more ▼]

The resources of space offer a means to enable sustainable exploration of the Moon and Solar System beyond, thus developing space resource technologies is becoming a major topic for space-related activity internationally. However, verifying and validating such systems on Earth conditions is challenging due to the difficulty of filling the sim2reality gap by creating the exact environment. We hypothesize that having on-ground experimental facilities that integrate high-fidelity simulation and physical systems will enable close-to-real testing, speeding up the transition between space technology development and deployment stages. NVIDIA Omniverse recently gained interest to create photorealistic environments, and it is a promising tool to simulate space-related scenarios with high fidelity. Physically accurate and faithful on-orbit scenarios could be generated in Omniverse Create by integrating PhysX physics core and Pixar Universal Scene Description. Omniverse also includes a robotic simulator that connects to physical robotic systems. Various connectors between Omniverse and other platforms such as Unreal Engine, Blender, Autodesk, ParaView, and online collaboration capacity offer the possibility of importing models of space mission components, space scenes, and scientific data into Omniverse. NVIDIA Omniverse seems auspicious in terms of developing high-fidelity photorealistic simulations. In the HELEN project between SpaceR and Spacety, we are developing a close-to-real testing environment for validating debris removal technology. Within this project, we will explore the potential of Omniverse to integrate virtual and physical components, i.e., high-fidelity photorealistic on-orbit simulations with the Zero-G lab facility, for creating reliable testing conditions to reduce the sim2reality gap. SIL and HIL testing architectures for space systems will be developed using software such as MATLAB/Simulink. Moreover, the robotic systems of the Zero-G lab can be linked to the Omniverse’s robotic simulator using its ROS & ROS2 bridge. The figure presents an overview of Omniverse under the scope of the HELEN project. HELEN will show the combination of photorealistic simulations using Omniverse, SIL, and HIL with the Zero-G lab creates a high-fidelity testing environment for future space resources technology. We also believe that the number of human-made objects orbiting the Earth constitutes a great potential for the recovery of their resources. Most of those include valuable materials (Aluminum, Gold, Silver). Therefore, in the future, debris mitigation efforts can target the recovery of such resources, as pointed out in [1]. Reference:[1] Frank Koch, The Value of Space Debris (2021), 8th European Conference on Space Debris [less ▲]

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See detail"Do we need an entire course about it?": Evaluating two years of teaching HCI in computer science
Rohles, Björn UL; Doublet, Sophie UL; Bongard, Kerstin UL et al

Scientific Conference (2022, May 01)

Educators increasingly agree on the importance of teaching Human-Computer Interaction (HCI) to Computer Science (CS) students, but there is debate on how to best integrate HCI into CS curricula ... [more ▼]

Educators increasingly agree on the importance of teaching Human-Computer Interaction (HCI) to Computer Science (CS) students, but there is debate on how to best integrate HCI into CS curricula. Unfortunately, standard course evaluations typically do not provide sufficient insights for improving HCI classes. In the present article, we used a human-centered design approach to evaluate our HCI classes, building on a qualitative study with CS students from four introductory HCI classes over two years. We report on a qualitative assessment through interviews, photo elicitation and sentence completion. Specifically, we addressed four research questions: which contents were the most relevant, how students experienced the courses, how they view the role of HCI in CS, and which outcomes they perceived from the HCI courses. We gathered rich qualitative insights beyond the standard course evaluations and derived concrete enhancements for future course iterations. We discuss implications for other HCI educators and contribute recommendations for the living HCI curriculum. Furthermore, we reflect on the usefulness of our methodological approach to collect in-depth constructive feedback from students. [less ▲]

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See detailDownlink Throughput of Cell-Free Massive MIMO Systems Assisted by Hybrid Relay-Reflecting Intelligent Surfaces
Nguyen, Nhan T.; Nguyen, V.-Dinh; Nguyen, Hieu V. et al

Poster (2022, May)

We consider in this work a cell-free (CF) massive multiple-input-multiple-output (mMIMO) system where multiple hybrid relay-reflecting intelligent surfaces (HR-RIS) are deployed to assist communication ... [more ▼]

We consider in this work a cell-free (CF) massive multiple-input-multiple-output (mMIMO) system where multiple hybrid relay-reflecting intelligent surfaces (HR-RIS) are deployed to assist communication between access points and users. We first present the signal model and derive the minimum-mean-square-error estimate of the effective channels. We then present a comprehensive analysis for the considered HR-RIS-aided CF mMIMO system, where the closed-form expression of the downlink throughput is derived. The presented analytical results are also valid for conventional CF mMIMO systems, i.e., CF mMIMO systems with and without passive reconfigurable intelligent surfaces. Finally, the analytical derivations are verified by extensive numerical results. [less ▲]

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See detailPreventing Frame Fingerprinting in Controller Area Network Through Traffic Mutation
Buscemi, Alessio UL; Turcanu, Ion; Castignani, German UL et al

in IEEE ICC 2022 Workshop - DDINS, Seoul 16-20 May 2022 (2022, May)

The continuous increase of connectivity in commercial vehicles is leading to a higher number of remote access points to the Controller Area Network (CAN) – the most popular in-vehicle network system. This ... [more ▼]

The continuous increase of connectivity in commercial vehicles is leading to a higher number of remote access points to the Controller Area Network (CAN) – the most popular in-vehicle network system. This factor, coupled with the absence of encryption in the communication protocol, poses serious threats to the security of the CAN bus. Recently, it has been demonstrated that CAN data can be reverse engineered via frame fingerprinting, i.e., identification of frames based on statistical traffic analysis. Such a methodology allows fully remote decoding of in-vehicle data and paves the way for remote pre-compiled vehicle-agnostic attacks. In this work, we propose a first solution against CAN frame fingerprinting based on mutating the traffic without applying modifications to the CAN protocol. The results show that the proposed methodology halves the accuracy of CAN frame fingerprinting. [less ▲]

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See detailIntegrating technology, education and practice to change energy behaviours in schools
Doherty, Edelle; Brychkov, Dmitry; Romero Herrera, Natalia et al

in CLIMA 2022 conference (2022, May)

Schools are learning communities where multiple stakeholders can collaborate to learn about energy efficiency, including via formal curricula, non-formal learning and day-to-day practices. Furthermore, by ... [more ▼]

Schools are learning communities where multiple stakeholders can collaborate to learn about energy efficiency, including via formal curricula, non-formal learning and day-to-day practices. Furthermore, by improving energy literacy among building occupants, the energy efficiency of schools can be improved. However, turning schools into learning communities rather than learning organizations is still problematic. This article details a case study realised in the form of the ENERGE project, which integrates technological, educational and practical activities in 13 post-primary schools from 6 European countries. Owing to an extensive collaboration of diverse stakeholders, the ENERGE project resulted in the origination of a learning community around energy efficiency in the schools. The outcomes of building a learning community within the ENERGE project included: capacity building (in the form of the ENERGE Committees and Teacher Network), the introduction of digital education (via the ENERGE digital platform), development of curriculum-based modules to raise energy literacy, and the establishment of a viable model for expanding ENERGE experience to other schools. The article concludes by explaining the benefits of the ENERGE approach for stakeholders. [less ▲]

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See detailEfficient Resource Scheduling and Optimization for Over-Loaded LEO-Terrestrial Networks
yuan, Yaxiong; Lei, Lei; Vu, Thang Xuan UL et al

in Proceeding of IEEE ICC 2022 (2022, May)

Towards the next generation networks, low earth orbit (LEO) satellites have been considered as a promising component for beyond 5G networks. In this paper, we study downlink LEO-5G communication systems ... [more ▼]

Towards the next generation networks, low earth orbit (LEO) satellites have been considered as a promising component for beyond 5G networks. In this paper, we study downlink LEO-5G communication systems in a practical scenario, where the integrated LEO-terrestrial system is over-loaded by serving a number of terminals with high-volume traffic requests. Our goal is to optimize resource scheduling such that the amount of undelivered data and the number of unserved terminals can be minimized. Due to the inherent hardness of the formulated quadratic integer programming problem, the optimal algorithm requires unaffordable complexity. To solve the problem, we propose a near-optimal algorithm based on alternating direction method of multipliers (ADMM-HEU), which saves computational time by taking advantage of the distributed ADMM structure, and a low-complexity heuristic algorithm (LC-HEU), which is based on estimation and greedy methods. The results demonstrate the near-optimality of ADMM-HEU and the computational efficiency of LC-HEU compared to the benchmarks. [less ▲]

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See detailAutomated Handling of Anaphoric Ambiguity in Requirements: A Multi-solution Study
Ezzini, Saad UL; Abualhaija, Sallam UL; Arora, Chetan et al

in In Proceedings of the 44th International Conference on Software Engineering (ICSE'22), Pittsburgh, PA, USA 22-27 May 2022 (2022, May)

Ambiguity is a pervasive issue in natural-language requirements. A common source of ambiguity in requirements is when a pronoun is anaphoric. In requirements engineering, anaphoric ambiguity occurs when a ... [more ▼]

Ambiguity is a pervasive issue in natural-language requirements. A common source of ambiguity in requirements is when a pronoun is anaphoric. In requirements engineering, anaphoric ambiguity occurs when a pronoun can plausibly refer to different entities and thus be interpreted differently by different readers. In this paper, we develop an accurate and practical automated approach for handling anaphoric ambiguity in requirements, addressing both ambiguity detection and anaphora interpretation. In view of the multiple competing natural language processing (NLP) and machine learning (ML) technologies that one can utilize, we simultaneously pursue six alternative solutions, empirically assessing each using a collection of ~1,350 industrial requirements. The alternative solution strategies that we consider are natural choices induced by the existing technologies; these choices frequently arise in other automation tasks involving natural-language requirements. A side-by-side empirical examination of these choices helps develop insights about the usefulness of different state-of-the-art NLP and ML technologies for addressing requirements engineering problems. For the ambiguity detection task, we observe that supervised ML outperforms both a large-scale language model, SpanBERT (a variant of BERT), as well as a solution assembled from off-the-shelf NLP coreference resolvers. In contrast, for anaphora interpretation, SpanBERT yields the most accurate solution. In our evaluation, (1) the best solution for anaphoric ambiguity detection has an average precision of ~60% and a recall of 100%, and (2) the best solution for anaphora interpretation (resolution) has an average success rate of ~98%. [less ▲]

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See detailSpatio-Temporal Rainfall Estimation from Communication Satellite Data using Graph Neural Networks
Krebs, Julian UL; Mishra, Kumar Vijay; Gharanjik, Ahmad et al

Scientific Conference (2022, May)

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See detailHUDD: A tool to debug DNNs for safety analysis
Fahmy, Hazem UL; Pastore, Fabrizio UL; Briand, Lionel UL

in 2022 IEEE/ACM 44th International Conference on Software Engineering (2022, May)

We present HUDD, a tool that supports safety analysis practices for systems enabled by Deep Neural Networks (DNNs) by automatically identifying the root causes for DNN errors and retraining the DNN. HUDD ... [more ▼]

We present HUDD, a tool that supports safety analysis practices for systems enabled by Deep Neural Networks (DNNs) by automatically identifying the root causes for DNN errors and retraining the DNN. HUDD stands for Heatmap-based Unsupervised Debugging of DNNs, it automatically clusters error-inducing images whose results are due to common subsets of DNN neurons. The intent is for the generated clusters to group error-inducing images having common characteristics, that is, having a common root cause. HUDD identifies root causes by applying a clustering algorithm to matrices (i.e., heatmaps) capturing the relevance of every DNN neuron on the DNN outcome. Also, HUDD retrains DNNs with images that are automatically selected based on their relatedness to the identified image clusters. Our empirical evaluation with DNNs from the automotive domain have shown that HUDD automatically identifies all the distinct root causes of DNN errors, thus supporting safety analysis. Also, our retraining approach has shown to be more effective at improving DNN accuracy than existing approaches. A demo video of HUDD is available at https://youtu.be/drjVakP7jdU. [less ▲]

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See detailEffective Rate of RIS-aided Networks with Location and Phase Estimation Uncertainty
Kong, Long; Kisseleff, Steven UL; Chatzinotas, Symeon UL et al

in Proceedings of IEEE Wireless Communications and Networking Conference (WCNC) (2022, May)

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See detailEfficient Online Testing for DNN-Enabled Systems using Surrogate-Assisted and Many-Objective Optimization
Ul Haq, Fitash UL; Shin, Donghwan UL; Briand, Lionel UL

in Proceedings of the 44th International Conference on Software Engineering (ICSE ’22) (2022, May)

With the recent advances of Deep Neural Networks (DNNs) in real-world applications, such as Automated Driving Systems (ADS) for self-driving cars, ensuring the reliability and safety of such DNN- enabled ... [more ▼]

With the recent advances of Deep Neural Networks (DNNs) in real-world applications, such as Automated Driving Systems (ADS) for self-driving cars, ensuring the reliability and safety of such DNN- enabled Systems emerges as a fundamental topic in software testing. One of the essential testing phases of such DNN-enabled systems is online testing, where the system under test is embedded into a specific and often simulated application environment (e.g., a driving environment) and tested in a closed-loop mode in interaction with the environment. However, despite the importance of online testing for detecting safety violations, automatically generating new and diverse test data that lead to safety violations present the following challenges: (1) there can be many safety requirements to be considered at the same time, (2) running a high-fidelity simulator is often very computationally-intensive, and (3) the space of all possible test data that may trigger safety violations is too large to be exhaustively explored. In this paper, we address the challenges by proposing a novel approach, called SAMOTA (Surrogate-Assisted Many-Objective Testing Approach), extending existing many-objective search algorithms for test suite generation to efficiently utilize surrogate models that mimic the simulator, but are much less expensive to run. Empirical evaluation results on Pylot, an advanced ADS composed of multiple DNNs, using CARLA, a high-fidelity driving simulator, show that SAMOTA is significantly more effective and efficient at detecting unknown safety requirement violations than state-of-the-art many-objective test suite generation algorithms and random search. In other words, SAMOTA appears to be a key enabler technology for online testing in practice. [less ▲]

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See detailMASS: A tool for Mutation Analysis of Space CPS
Cornejo Olivares, Oscar Eduardo UL; Pastore, Fabrizio UL; Briand, Lionel UL

in 2022 IEEE/ACM 44st International Conference on Software Engineering (2022, May)

We present MASS, a mutation analysis tool for embedded software in cyber-physical systems (CPS). We target space CPS (e.g., satellites) and other CPS with similar characteristics (e.g., UAV). Mutation ... [more ▼]

We present MASS, a mutation analysis tool for embedded software in cyber-physical systems (CPS). We target space CPS (e.g., satellites) and other CPS with similar characteristics (e.g., UAV). Mutation analysis measures the quality of test suites in terms of the percentage of detected artificial faults. There are many mutation analysis tools available, but they are inapplicable to CPS because of scalability and accuracy challenges. To overcome such limitations, MASS implements a set of optimization techniques that enable the applicability of mutation analysis and address scalability and accuracy in the CPS context. MASS has been successfully evaluated on a large study involving embedded software systems provided by industry partners; the study includes an on-board software system managing a microsatellite currently on-orbit, a set of libraries used in deployed cubesats, and a mathematical library provided by the European Space Agency. A demo video of MASS is available at https://www.youtube.com/watch?v=gC1x9cU0-tU. [less ▲]

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See detailDynamic Bandwidth Allocation and Edge Caching Optimization for Nonlinear Content Delivery through Flexible Multibeam Satellites
Vu, Thang Xuan UL; Maturo, Nicola; Chatzinotas, Symeon UL et al

in IEEE International Conference on Communications (2022, May)

The next generation multibeam satellites open up a new way to design satellite communication channels with the full flexibility in bandwidth, transmit power and beam coverage management. In this paper, we ... [more ▼]

The next generation multibeam satellites open up a new way to design satellite communication channels with the full flexibility in bandwidth, transmit power and beam coverage management. In this paper, we exploit the flexible multibeam satellite capabilities and the geographical distribution of users to improve the performance of satellite-assisted edge caching systems. Our aim is to jointly optimize the bandwidth allocation in multibeam and caching decisions at the edge nodes to address two important problems: i) cache feeding time minimization and ii) cache hits maximization. To tackle the non-convexity of the joint optimization problem, we transform the original problem into a difference-of-convex (DC) form, which is then solved by the proposed iterative algorithm whose convergence to at least a local optimum is theoretically guaranteed. Furthermore, the effectiveness of the proposed design is evaluated under the realistic beams coverage of the satellite SES-14 and Movielens data set. Numerical results show that our proposed joint design can reduce the caching feeding time by 50% and increase the cache hit ratio (CHR) by 10% to 20% compared to existing solutions. Furthermore, we examine the impact of multispot beams and multicarrier wide-beam on the joint design and discuss potential research directions. [less ▲]

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See detailA Collaborative System of Flying and Ground Robots with Universal Physical Coupling Interface (PCI), and the Potential Interactive Applications
Wang, Ziming UL; Hu, Ziyi; Man, Yemao et al

Poster (2022, April 28)

Flying and ground robots complement each other in terms of their advantages and disadvantages. We propose a collaborative system combining flying and ground robots, using a universal physical coupling ... [more ▼]

Flying and ground robots complement each other in terms of their advantages and disadvantages. We propose a collaborative system combining flying and ground robots, using a universal physical coupling interface (PCI) that allows for momentary connections and disconnections between multiple robots/devices. The proposed system may better utilize the complementary advantages of both flying and ground robots. We also describe various potential scenarios where such a system could be of benefit to interact with humans - namely, remote field works and rescue missions, transportation, healthcare, and education. Finally, we discuss the opportunities and challenges of such systems and consider deeper questions which should be studied in future work. [less ▲]

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See detailIntersectional inequalities in science
Kozlowski, Diego UL

Scientific Conference (2022, April 28)

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See detailThe Luxembourg Financial Ecosystem and the European Monetary Innovation. Cas Study on KBL, LuxSE and EIB (1957-1990)
Danescu, Elena UL; Cheng, Anqi

Scientific Conference (2022, April 26)

The Luxembourg international financial centre developed considerably during the 1960s, propelled by several factors including concerted government policy, flexible regulation and a willingness to harness ... [more ▼]

The Luxembourg international financial centre developed considerably during the 1960s, propelled by several factors including concerted government policy, flexible regulation and a willingness to harness opportunities at international level (such as the 1963 US interest equalisation tax and the Bundesbank provisions introduced in 1968 and 1974). The decision to establish various Community institutions (the ECSC High Authority in 1952) and European funding institutions (the European Investment Bank in 1968) in the country also had a decisive impact. The currency union with Belgium (BLEU, 1921) and the absence of a Luxembourg Central Bank made these developments all the more significant. Drawing on archives and oral history sources, this paper aims to illustrate the complexity and originality that characterised the development of the conceptual, political and regulatory context in Luxembourg in the 1960s-1990s, in what can be seen as a sui generis experiment and preparation for EMU. It will explore the changing financial ecosystem in Luxembourg and the collaborative efforts by its main stakeholders (banks, regulatory authorities, individuals, networks) - with a focus on KBL, LuxSE and EIB - to encourage financial and monetary innovation (via the EUA, ECU, and Eurco) before the introduction of the European single currency and to pave the way for the establishment and consolidation of the euro [less ▲]

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See detailContext, Prioritization, and Unexpectedness: Factors Influencing User Attitudes About Infographic and Comic Consent
Doan, Xengie Cheng UL; Selzer, Annika; Rossi, Arianna UL et al

in Web Conference Companion Volume (ACM) (2022, April 26)

Being asked to consent to data sharing is a ubiquitous experience in digital services - yet it is very rare to encounter a well designed consent experience. Considering the momentum and importance of a ... [more ▼]

Being asked to consent to data sharing is a ubiquitous experience in digital services - yet it is very rare to encounter a well designed consent experience. Considering the momentum and importance of a European data space where personal information freely and easily flows across organizations, sectors and Member States, solving the long-discussed thorny issue of "how to get consent right" cannot be postponed any further. In this paper, we describe the first findings from a study based on 24 semi-structured interviews investigating participants’ expectations and opinions toward consent in a data sharing scenario with a data trustee. We analyzed various dimensions of a consent form redesigned as a comic and an infographic, including language, information design, content and the writer-reader relationship. The results provide insights into the complexity of elements that should be considered when asking individuals to freely and mindfully disclose their data, especially sensitive information. [less ▲]

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See detailRKHS Based State Estimator for Radar Sensor in Indoor Application
Kumar Singh, Uday UL; Shankar, Bhavani; Alaee, Mohammad

Scientific Conference (2022, April 23)

For the estimation of targets’ states (location, velocity, and acceleration) from nonlinear radar measurements, usually, the improved version of well known Kalman filter: extended Kalman filter (EKF) and ... [more ▼]

For the estimation of targets’ states (location, velocity, and acceleration) from nonlinear radar measurements, usually, the improved version of well known Kalman filter: extended Kalman filter (EKF) and unscented Kalman filter (UKF) are used. However, EKF and UKF approximates the nonlinear measurement function either by Jacobian or using sigma points. Consequently, because of the approximation of the measurement function, the EKF and UKF cannot achieve high estimation accuracy. The potential solution is to replace the approximation of nonlinear measurement function with its estimate, obtained in high dimensional reproducing kernel Hilbert space (RKHS). An ample amount of research has been done in this direction, and the combined filter is termed RKHS based Kalman filter. However, there is a shortage of literature dealing with estimating the dynamic state of the target in an indoor environment using RKHS based Kalman filter. Therefore, in this paper, we propose the use of RKHS based Kalman filter for indoor application. Specifically, we validate the suitability of the RKHS based Kalman filtering approach using simulations performed over three different target motion models. [less ▲]

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See detailThe positional value of education in the Americas: dynamics of inequality in labour market returns for highly unequal countries, 2000-2019
Ceron, Francisco UL; Chauvel, Louis UL

Scientific Conference (2022, April 22)

The article examines how the labour market value of education has changed in the context of the expansion of higher education. However, one drawback is understanding how it generates differences between ... [more ▼]

The article examines how the labour market value of education has changed in the context of the expansion of higher education. However, one drawback is understanding how it generates differences between high and low-skilled labour markets, particularly in contexts of high inequality and informality. This could be linked to specific mechanisms by which employers value educational credentials as signalled skills. Using the Luxembourg Income Study (LIS), we analyse trends over two decades in 11 American countries. Our results confirm the previous results for the claim that education has become increasingly positional, compared with the absolute model of education. However, we find that the relative gains in wages for workers with higher levels of education, as the pool of higher education graduates expand over time, increased only slightly in high-skilled occupations, while their relative gains decreased for lower-skilled occupations. This trend is present in both absolute and positional models of education. Moreover, when looking at the structure of labour markets in terms of the linkage between educational credentials and occupational groups, we higher the tertiary education specificity of occupations, the higher the earnings for workers with advantaged positions. These findings are consistent with processes of displacement of low-skilled workers due to increasing competition among highly educated workers, from the positional model of education. [less ▲]

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See detailAcademic Profile Development: An Investigation of Differentiation Processes Based on Students' Achievement and Grade Level
Breit, Moritz; Brunner, Martin; Fischbach, Antoine UL et al

Scientific Conference (2022, April 21)

Academic achievement profiles affect students’ further development, i.e., by informing educational and professional choices. However, there is a lack of knowledge on the mechanisms behind the development ... [more ▼]

Academic achievement profiles affect students’ further development, i.e., by informing educational and professional choices. However, there is a lack of knowledge on the mechanisms behind the development of academic profiles. For research on cognitive ability profiles, specifically differentiation processes, statistical tools have been developed. In the present article, we transfer these methods for differentiation research to academic achievement data. We examine differentiation depending on students’ general level of achievement and grade level in a large Luxembourgish student sample. Students’ achievements in German, French, and Math were assessed within the Luxembourg school monitoring program. We found more balanced academic profiles with increasing achievement level. We further found more balanced profiles with increasing grade level and a positive interaction effect. [less ▲]

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See detailEsclavage, servitude, travail forcé : constitution et évolution d’un cadre conceptuel
Erpelding, Michel UL

in Marchadier, Fabien (Ed.) La prohibition de l'esclavage (2022, April 20)

This chapter examines the emergence, definition and evolution of the concepts of slavery, forced labour and servitude in international law.

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See detailA new R package for Finite Mixture Models with an application to pension systems
Schiltz, Jang UL; Noel, Cédric

Scientific Conference (2022, April 20)

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See detailInhomogeneities in lead halide perovskite absorbers revealed by quantitative Photoluminescence Imaging
Phirke, Himanshu UL; Singh, Ajay UL; Hieulle, Jeremy UL et al

in Phirke, Himanshu; Singh, Ajay; Hieulle, Jeremy (Eds.) et al Inhomogeneities in lead halide perovskite absorbers revealed by quantitative Photoluminescence Imaging (2022, April 20)

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See detailThe effect of dataset confounding on predictions of deep neural networks for medical imaging
Garcia Santa Cruz, Beatriz UL; Husch, Andreas UL; Hertel, Frank UL

in Vol. 3 (2022): Proceedings of the Northern Lights Deep Learning Workshop 2022 (2022, April 18)

The use of Convolutional Neural Networks (CNN) in medical imaging has often outperformed previous solutions and even specialists, becoming a promising technology for Computer-aided-Diagnosis (CAD) systems ... [more ▼]

The use of Convolutional Neural Networks (CNN) in medical imaging has often outperformed previous solutions and even specialists, becoming a promising technology for Computer-aided-Diagnosis (CAD) systems. However, recent works suggested that CNN may have poor generalisation on new data, for instance, generated in different hospitals. Uncontrolled confounders have been proposed as a common reason. In this paper, we experimentally demonstrate the impact of confounding data in unknown scenarios. We assessed the effect of four confounding configurations: total, strong, light and balanced. We found the confounding effect is especially prominent in total confounder scenarios, while the effect on light and strong confounding scenarios may depend on the dataset robustness. Our findings indicate that the confounding effect is independent of the architecture employed. These findings might explain why models can report good metrics during the development stage but fail to translate to real-world settings. We highlight the need for thorough consideration of these commonly unattended aspects, to develop safer CNN-based CAD systems. [less ▲]

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See detailTranslanguaging pedagogy and creative activism for preschool teachers, parents, and children
Aleksic, Gabrijela UL

Scientific Conference (2022, April 18)

Today’s education is impacted by the fast changes that can be very challenging for teachers, parents, and students. The need of pedagogies that will support them to navigate through these changes and ... [more ▼]

Today’s education is impacted by the fast changes that can be very challenging for teachers, parents, and students. The need of pedagogies that will support them to navigate through these changes and challenges, becomes evident, especially in highly linguistically and culturally diverse countries such as the small trilingual Grand-Duchy of Luxembourg. One of such pedagogies is translanguaging pedagogy. While translanguaging refers to the natural use of entire linguistic repertoire of bi/multilingual people, translanguaging pedagogy helps teachers to use bi/multilingual students’ unique linguistic repertoires to foster learning, comprehension, and academic achievement (Otheguy, García, & Reid, 2015). In Luxembourg, there are 64 % of four-year old children who not speak Luxembourgish at home (MENJE, 2018). Therefore, in 2017, multilingual early education has become mandatory obliging teachers to help students to develop Luxembourgish, familiarize them with French, and value their home languages. Thus, in order to support teachers’ work, there were three objectives of the present project : (1) to administer an 18-hours professional development (PD) course in translanguaging pedagogy to 40 preschool teachers, (2) to actively include students’ families in order to straighten home-school collaboration, and (3) to support children’s linguistic, socio-emotional, and cognitive development and engagement in the classroom. The PD course was divided into seven sessions on multilingual ecology, home-school collaboration, multilingual brain, and multilingual oracy and literacy, over 6 months. To evaluate the success of these aims, before and after the course, we employed teacher questionnaires, focus groups, and interviews with the teachers, parent questionnaires and interviews with the parents, and early literacy and numeracy tests in the school and home languages as well as video observations of classroom interactions with the students. Regarding the teachers, the results from the teacher questionnaire before and after the course, showed that there was a significant positive change in attitudes towards children’s multilingualism and their home languages. However, in the focus groups and the interviews, we identified that most of the teachers were open to the use children’s home languages only to develop the school language, Luxembourgish. In the analysis of the video observations of teacher/child interactions, we observed that when the home language of children was used, this immediately contributed to their well-being. However, we also observed that in some classrooms the use of children’s home languages was artificial; the teachers insisted on naming home languages instead of giving the children the opportunity to use the school language and be proud of it. Regarding the parents, the analysis of 65 questionnaires on children’s home literacy environment and the interviews showed that parental involvement is crucial for children’s linguistic and socio-emotional development. The interviewed parents shared that they would like to be more involved in the home-school collaboration but they did not know how. Although they were open for more collaboration, most of the parents thought that this should be initiated from the teachers. Finally, regarding the children, we observed the linguistic and socio-emotional development of 23 children (age 4) over one year. The children were tested in early literacy and numeracy, three times over the course of one year. When plotting the results, we identified that all children performed better in their home languages than in the school language and that there was a progress in both home and school language over one year. Furthermore, the video observations showed that when translanguaging pedagogy was used and children’s home languages were valued, children were more responsive and eager to learn and interact with others. Following these results and in order to connect teachers, parents, and children, I developed a website for teachers with the summary of important theories in multilingualism supported by many practical activities in the domain of multilingual classroom, home-school collaboration, and multilingual oracy and literacy. The website is in English, French, and German, and teachers can find a solid support for their work. Furthermore, I wrote two illustrated books for parents and children. In the illustrated book for parents the main character is a woman called Sumak who moved from another country as a refugee and is forced to learn a new language in a society she does not fit in. A storytelling workshop will allow teachers and parents to share their experience and connect on a deeper level. In the book for children, the main character is a girl called Mara who moved to a new country and does not understand the school language. She is sad and angry and tries to find solutions, for example, in music. The book contains a CD with in which the character Mara sings the song in Mara’s language, allowing teachers and children to hear that it is ok to speak in a language they do not understand. The illustrated books exist in English, French, Serbian, Portuguese, and German. These creations are an act of creative activism, which are “transformative interventions in order to change society for the better by communicating conflicts and/or solutions where no one else can or will in order to provoke reflection (and consequent behavioral changes)” (Harrebye, 2016, p. 25). Finally, this is an act of going beyond the horizons and the project results, and reimagining everything, especially playing with new ideas and applying those through specific creative acts that bring teachers, parents, and children together. The Conference will allow me to showcase these creative interventions, discuss their impact on the schools, and offer them to international researchers who work in education and beyond. References Ministry of National Education, Childhood and Youth [MENJE]. (2018). Les chiffres clés de l'Éducation nationale: statistiques et indicateurs - Année scolaire 2016-2017 [Key numbers of the national education: statistics and indicators – School year 2016-2017]. Retrieved from http://www.men.public.lu/fr/actualites/publications/themes-transversaux/statistiques-analyses/chiffres-cles/index.html Harrebye S.F. (2016) Creative activism today. In: Social change and creative activism in the 21st century. London: Palgrave Macmillan. Otheguy, R., García, O., & Reid, W. (2015). Clarifying translanguaging and deconstructing named langauges: A perspective from linguistics. Applied Linguistic Review, 6(3), 281–307. [less ▲]

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See detailSustainability and Circular Economy in Learning Factories – Case Studies
Weyand, Astrid; Thiede, Sebastian; Mangers, Jeff UL et al

in SSRN (2022, April 11)

Since the mitigation of climate change is one of the biggest challenges to face on a global scale, the topic has become more relevant also in industrial context. Learning factories have proven to be ... [more ▼]

Since the mitigation of climate change is one of the biggest challenges to face on a global scale, the topic has become more relevant also in industrial context. Learning factories have proven to be suitable environments to address and convey competencies to tackle industrial challenges in an interactive way. Hence, several learning factories are already dealing with sustainability topics in various use cases. This paper strives to present a state of the art of sustainability and circular economy in learning factories. Therefore, a classification framework is developed based on the state of the art of several learning factories and existing literature regarding the topic. This framework is then used to systematically describe the different activities regarding sustainability and circular economy that are currently ongoing in learning factories worldwide. This can be used to get an idea about the different aspects of the topic and how to address them, but furthermore also offers assistance to identify “blind spots” which could and should be addressed in learning factories in the future. [less ▲]

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See detailDifferential Phase Compensation in Over-the-air Precoding Test-bed for a Multi-beam Satellite
Martinez Marrero, Liz UL; Merlano Duncan, Juan Carlos UL; Querol, Jorge UL et al

Scientific Conference (2022, April 10)

This article presents a closed-loop differential phase compensation system for a precoding-enabled multibeam satellite forward link and its validation by live experiments on a GEO satellite scenario. The ... [more ▼]

This article presents a closed-loop differential phase compensation system for a precoding-enabled multibeam satellite forward link and its validation by live experiments on a GEO satellite scenario. The precoding operation avoids inter-beam interference and maximizes the spectrum efficiency by full frequency reuse as an alternative to the traditional two-color or four-color reuse methods proposed in the DVB-S2 standard. However, the satellite payload introduces differential phase and frequency impairments, which can degrade the precoding performance. This work describes the implementation of the differential phase and frequency tracking and compensation loop in an end-to-end testbed over a multibeam satellite system with independent local oscillators. The developed system performs end-to-end real-time communication over the satellite link, including channel measurements and precompensation. Results are validated by an over-the-air demonstration using two beams of the SES-14 multibeam satellite. Each beam is transmitted by independent transponders, which results in differential frequency and phase offsets due to the transponder undisciplined local oscillators. This phase offset makes it impossible to use precoding without the phase compensation loop. We prove that the implemented system can successfully track and compensate the differential phase and frequency to improve precoding performance. [less ▲]

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See detailD-ViNE: Dynamic Virtual Network Embedding in Non-Terrestrial Networks
Maity, Ilora UL; Vu, Thang Xuan UL; Chatzinotas, Symeon UL et al

in IEEE Wireless Communications and Networking Conference (WCNC) (2022, April 10)

In this paper, we address the virtual network embedding (VNE) problem in non-terrestrial networks (NTNs) enabling dynamic changes in the virtual network function (VNF) deployment to maximize the service ... [more ▼]

In this paper, we address the virtual network embedding (VNE) problem in non-terrestrial networks (NTNs) enabling dynamic changes in the virtual network function (VNF) deployment to maximize the service acceptance rate and service revenue. NTNs such as satellite networks involve highly dynamic topology and limited resources in terms of rate and power. VNE in NTNs is a challenge because a static strategy under-performs when new service requests arrive or the network topology changes unexpectedly due to failures or other events. Existing solutions do not consider the power constraint of satellites and rate limitation of inter-satellite links (ISLs) which are essential parameters for dynamic adjustment of existing VNE strategy in NTNs. In this work, we propose a dynamic VNE algorithm that selects a suitable VNE strategy for new and existing services considering the time-varying network topology. The proposed scheme, D-ViNE, increases the service acceptance ratio by 8.51% compared to the benchmark scheme TS-MAPSCH. [less ▲]

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