Coexistence of eMBB and URLLC in Open Radio Access Networks: A Distributed Learning Framework

in IEEE Global Communications Conference (IEEE Globecom), Rio de Janeiro, Brazil, Dec. 2022 (2022, December)

XAI: Using Smart Photobooth for Explaining History of Art

in XAI: Using Smart Photobooth for Explaining History of Art (2022, December)

The rise of Artificial Intelligence has led to advancements in daily life, including applications in industries, telemedicine, farming, and smart cities. It is necessary to have human-AI synergies to ... [more ▼]

The rise of Artificial Intelligence has led to advancements in daily life, including applications in industries, telemedicine, farming, and smart cities. It is necessary to have human-AI synergies to guarantee user engagement and provide interactive expert knowledge, despite AI’s success in "less technical" fields. In this article, the possible synergies between humans and AI to explain the development of art history and artistic style transfer are discussed. This study is part of the "Smart Photobooth" project that is able to automatically transform a user’s picture into a well-known artistic style as an interactive approach to introduce the fundamentals of the history of art to the common people and provide them with a concise explanation of the various art painting styles. This study investigates human-AI synergies by combining the explanation produced by an explainable AI mechanism with a human expert’s insights to provide reasons for school students and a larger audience. [less ▲]

Lost in legal data visualization? A legal scholar’s view on the ECB dedicated section in EUR-Lex

in European Central Bank (Ed.) ESCB Legal Conference 2022 (2022, December)

Legal data visualisation and legal knowledge visualisation are increasingly attracting the attention of the legal community, given their alleged positive impact on legal teaching, access to and ... [more ▼]

Legal data visualisation and legal knowledge visualisation are increasingly attracting the attention of the legal community, given their alleged positive impact on legal teaching, access to and understanding of the law by citizens and/or litigants, or the production of new legal products or services (e.g. Stanford Legal Design Lab). On the other hand, very few legal research studies are based on and integrate into their analysis the visualization of legal data, legal information, or of legal knowledge. Even fewer studies examine the impact of these tools on legal research methodology. Legal scholars are no less skilled and familiar with the use of IT tools, from preparing their lectures (e.g. ppt presentations) to consulting online databases or using expert systems to review articles. Is the lack of interest in legal data visualisation tools an expression of any technological difficulty? To use Friedrich Lachmayer's metaphor, "Legal informatics, which includes the visualisation of legal data, is about building a bridge between law and informatics. But in the design of visualisation tools, informatics scholars expect too much from legal scholars, then the latter give up and the bridge collapses. Or does the problem stem from a specific feature of the law, namely the ontological formalism of legal norms, which would prevent the dissemination of these tools - or render them useless? Rather than exploring this issue from a theoretical perspective, this study will examine the relevance of legal data visualization tools through the analysis of a concrete case, namely the updating that the present author is to carry out of the "Euro" section, published in the French Répertoire Dalloz. This section, originally written in 2002 by Professor Jean-Victor Louis, analyses the monetary law of the Union. In addition to updating the references to the relevant legal acts and instruments in force, this new version should also highlight changes to the content of the lex monetae and related legislation (protection of banknotes and coins, anti-counterfeiting measures, conversion and rounding procedures, etc.). As part of the updating process, the research methodology will be based on the visualisation tools made available by EUR-lex. The study will therefore examine the extent to which these tools have supported the research and facilitated the identification of new insights. Or, on the contrary, to what extent they proved to be inappropriate or insufficient and, if so, for what reasons? [less ▲]

Joint Linear Precoding and DFT Beamforming Design for Massive MIMO Satellite Communication

in IEEE Global Communications Conference GLOBECOM 2022 (2022, December)

"The Origins Of Chess" A Digital 3D Chess Artwork with Physics & AI

Scientific Conference (2022, November 30)

Chess and Artificial Intelligence (AI) have always been connected together as the game naturally challenges the ability of a computer to think. In this work, we present a novel chess game using AI and 3D ... [more ▼]

Chess and Artificial Intelligence (AI) have always been connected together as the game naturally challenges the ability of a computer to think. In this work, we present a novel chess game using AI and 3D technology for the implementation of the engine as well as for the physical installation of the game. For the engine, the Minimax algorithm is utilized to calculate the best possible move. The game is installed at the ”AI and Art” exhibition in the Computational Creativity Hub (CCH) of the University of Luxembourg. [less ▲]

Security Modeling and Analysis of Moving Target Defense in Software Defined Networks

in Security Modeling and Analysis of Moving Target Defense in Software Defined Networks (2022, November 28)

The use of traditional defense mechanisms or intrusion detection systems presents a disadvantage for defenders against attackers since these mechanisms are essentially reactive. Moving target defense (MTD ... [more ▼]

The use of traditional defense mechanisms or intrusion detection systems presents a disadvantage for defenders against attackers since these mechanisms are essentially reactive. Moving target defense (MTD) has emerged as a proactive defense mechanism to reduce this disadvantage by randomly and continuously changing the attack surface of a system to confuse attackers. Although significant progress has been made recently in analyzing the security effectiveness of MTD mechanisms, critical gaps still exist, especially in maximizing security levels and estimating network reconfiguration speed for given attack power. In this paper, we propose a set of Petri Net models and use them to perform a comprehensive evaluation regarding key security metrics of Software-Defined Network (SDNs) based systems adopting a time-based MTD mechanism. We evaluate two use-case scenarios considering two different types of attacks to demonstrate the feasibility and applicability of our models. Our analyses showed that a time-based MTD mechanism could reduce the attackers’ speed by at least 78% compared to a system without MTD. Also, in the best-case scenario, it can reduce the attack success probability by about ten times. [less ▲]

Predicting depression in old age: Combining life course data with machine learning

Scientific Conference (2022, November 24)

Attitudes, Preconceptions and Practices in Conversational AI Design

Scientific Conference (2022, November 23)

Economic Ideas and Political Action in Shaping Economic and Monetary Union: Pierre Werner and Luxembourg

in Danescu, Elena; Dima, Alina (Eds.) Fostering recovery through metaverse business modelling - An interdisciplinary analysis of the new paradigm shift (2022, November 19)

The international financial centre in Luxembourg grew considerably in the 1960s, driven by proactive government policy, flexible regulation, a willingness to harness external opportunities and the ... [more ▼]

The international financial centre in Luxembourg grew considerably in the 1960s, driven by proactive government policy, flexible regulation, a willingness to harness external opportunities and the establishment of Community institutions and European funding institutions in the country. As Luxembourg was in a currency union with Belgium within the Belgium-Luxembourg Economic Union and did not have its own Central Bank, these developments were all the more meaningful. When the European integration process experienced a series of major crises – including the failure of the European Defence Community and European Political Community in 1954, the empty chair crisis in 1966 and General de Gaulle’s veto on British accession in 1962 and 1967 –, Luxembourg set out on the path of European monetary integration, under the impetus of Finance Minister and Prime Minister Pierre Werner. In October 1970, the Werner Report provided a detailed blueprint for Economic and Monetary Union and laid the foundations for the euro. The Luxembourg financial centre would serve as a “laboratory” for the future single currency. This paper makes extensive use of relevant European and international archives and original interviews, adopting an interdisciplinary approach to analyse Luxembourg’s leading role in reconciling different views on EMU and fostering political commitment to a European currency among the Member States. [less ▲]

Fantômes et revenants : dispersion, destruction et reconstitution par « traces » du fonds des chirographes échevinaux de Tournai

Scientific Conference (2022, November 17)

Les centaines de milliers de chirographes échevinaux (contrats d’intérêt privé réalisés en multiples exemplaires sur une même feuille de parchemin) de Tournai, déjà amoindris par leur vente ... [more ▼]

Les centaines de milliers de chirographes échevinaux (contrats d’intérêt privé réalisés en multiples exemplaires sur une même feuille de parchemin) de Tournai, déjà amoindris par leur vente partielle au poids en 1820-23, ont été détruits sous les bombes allemandes en 1940. Après avoir reparcouru l’histoire mouvementée de ce fonds documentaire, nous montrerons comment, à partir de différentes sortes de « traces » laissées par les chirographes tournaisiens avant leur disparition et du suivi des migrations des originaux après leur dispersion, il est encore possible d’avoir un aperçu substantiel de la portion médiévale de cette collection, y compris dans certains aspects matériels. Nous insisterons enfin sur des aspects méthodologiques du traitement de ces données dans un logique de constitution d’un corpus, en nous focalisant sur la question de l’estimation quantitative, à partir de témoignages parfois discordants, de la consistance passée du fonds et, partant, de la proportion des pertes [less ▲]

Migration and ageing: The sense of belonging of first-generation Portuguese migrants in Luxembourg

Scientific Conference (2022, November 15)

The need to belong is fundamental to human beings and constitutes a basis for subjective well-being. It is closely linked to further concepts, such as identification, connectedness, attachment, fitting in ... [more ▼]

The need to belong is fundamental to human beings and constitutes a basis for subjective well-being. It is closely linked to further concepts, such as identification, connectedness, attachment, fitting in and feeling “at home”. Migration is a life transition that entails changes in social and emotional belonging. Former social network members might be left behind in the country of origin, and an important developmental task for migrants is therefore the establishment of bonds in the receiving country. As first-generation immigrants of the past decades are now close to retirement age, the question of home and belonging has become particularly pertinent also with regard to their future plans and concerning their intergenerational relations. The present contribution will focus on the sense of belonging of first generation Portuguese immigrants living in Luxembourg by drawing on data from the FNR-funded IRMA study on “Intergenerational Relations in the light of Migration and Ageing”. Selected results with regard to future plans and intergenerational relations will be presented. Further, applying the lens of cultural psychology of semiotic mediation, the development of a sense of belonging will be traced by taking a life span perspective and drawing on concepts such as proculturation and the Trajectory Equifinality Approach. [less ▲]

Tradition - Zukunft - Bedürfnisse. Luxemburgische Blasmusik

Scientific Conference (2022, November 12)

Maintenir actif et attractif un cours en ligne créé sur Moodle pour les étudiants d'échange

Scientific Conference (2022, November 11)

Gender and diversity representations in textbooks in Luxembourgish secondary education.

Poster (2022, November 10)

Teaching materials, and particularly textbooks, play an essential role in the socialisation of children through the communication of values. As „textbooks are not a reflection of reality, but an ... [more ▼]

Teaching materials, and particularly textbooks, play an essential role in the socialisation of children through the communication of values. As „textbooks are not a reflection of reality, but an arrangement of the representation of a society that they legitimise” (Brugeilles & Cromer, 2008, p.42), we argue that they contribute to challenging, perpetuating, or increasing gender inequalities. The results of our first study on Luxemburgish primary school textbooks, already published, indicate an androcentric view (Kerger & Brasseur, 2021). In every textbook, we counted more male than female characters in the texts and the illustrations. Men are more often represented in professional activities, while women are more likely to perform domestic activities. The celebrities represented are more often men than women. This poster presents the results of history textbooks in secondary school. It shows an ethnocentric perspective on the representation of non-white characters and those with disabilities. People with disabilities are almost exclusively portrayed when disability as a subject is being discussed. Use of racist language. These representations do not transmit the realities of societal complexities and they contribute to the marginalization and discrimination of non-white people and people with disabilities. [less ▲]

Towards a fairer assessment of cognitive abilities in multilingual children

Scientific Conference (2022, November 10)

Development of a test battery to diagnose specific learning disorder in reading in a multilingual education context

Scientific Conference (2022, November 10)

Providing timely and adequate support to children experiencing difficulties in reading and writing is key to minimize the impact on children’s academic achievements, social and emotional well-being ... [more ▼]

Providing timely and adequate support to children experiencing difficulties in reading and writing is key to minimize the impact on children’s academic achievements, social and emotional well-being, particularly for children with specific learning disorders. However, the diagnostic process is especially challenging in Luxembourg’s multilingual educational system with changing instruction languages (Luxembourgish, German, French) and multilingual population. The chosen language of the diagnostic tool is usually identical to the main language of instruction at school, which at time of diagnosis (typically grade 3) is German. This may especially affect the diagnosis of children who do not speak German or Luxembourgish at home as data from the Luxembourgish national school monitoring program reveals significant differences in German reading comprehension in grade 3 depending on the language spoken at home (Hoffmann et al., 2018; Martini et al., 2021). Furthermore, the diagnostic tools currently employed in Luxembourg are developed in countries with primarily one language of instruction, challenging the validity of the diagnostic process in a multilingual population (Ugen et al., 2021). The aim of the current project is to develop a diagnostic tool adapted to the Luxembourgish educational curriculum, that takes children’s potential proficiency differences in the test language into account in the instructions, tasks and resulting norms. This way, over-diagnosis of reading and writing disorders in children who do not speak the main language(s) of instruction at home and underdiagnosis of children who do, can be avoided. The developed test battery assesses children’s performance in key domains relevant for reading and writing comprising phonological skills, (non)word and text reading (fluency and accuracy), reading comprehension, writing, and vocabulary. We will present the pre-test results of 9 sub-tests completed by 214 children, providing the first insights into the test development and validation process.   References Hoffmann, D., Hornung, C., Gamo, S., Esch, P., Keller, U., & Fischbach, A. (2018). Schulische Kompetenzen von Erstklässlern und ihre Entwicklung nach zwei Jahren. In T. Lentz, I. Baumann, & A. Küpper (Eds.), Nationaler Bildungsbericht (pp. 84–96). University of Luxembourg & SCRIPT. Martini, S., Schiltz, C., Fischbach, A., & Ugen, S. (2021). Identifying Math and Reading Difficulties of multilingual children: Effects of different cut-offs and reference group. In M. Herzog, A. Fritz-Stratmann, & E. Gürsoy (Eds.), Diversity Dimensions in Mathematics and Language Learning (pp. 200–228). De Gruyter Mouton. Ugen, S., Schiltz, C., Fischbach, A., & Pit-ten Cate, I. M. (2021). Einleitung: Lernstörungen im multilingualen Kontext – Eine Herausforderung. In Ugen, S., Schiltz, C., Fischbach, A., & Pit-ten Cate, I. M. (Eds.), Lernstörungen im multilingualen Kontext. Diagnose und Hilfestellungen (pp3-7). Luxembourg: Melusina Press. [less ▲]

Implementation of a large-scale functional vision screener in early childhood at a national level

Scientific Conference (2022, November 10)

Functional vision refers to the way in which an individual uses visual skills and abilities to perform everyday tasks. Limitations on the functional use of vision can interfere with school achievements if ... [more ▼]

Functional vision refers to the way in which an individual uses visual skills and abilities to perform everyday tasks. Limitations on the functional use of vision can interfere with school achievements if left undetected. Early detection is thus key to offer appropriate aids to avoid a negative impact on learning processes. To screen for functional vision impairments at a national level, we developed a set of items measuring visual skills that can be administered in a classroom setting to be included in the yearly school monitoring tests ‘ÉpStan’ in grade 1. Children identified as being at risk will be followed by the Centre pour le Développement des compétences relatives à la Vue (CDV, MENJE). Based on a theoretical model of visual perceptual processing (Humphreys and Riddoch, 1987), we developed 35 items that were pretested. The same first graders (n = 1034) were administered group tests with the newly developed items and existing standardized individual tests (by CDV clinicians). Based on the clinical outcome of the CDV, the items which best predicted functional vision impairments were selected to be implemented in the Luxembourgish school monitoring in grade 1, together with a validated short parent questionnaire (Gorrie et al., 2019). This talk will focus on the development of the screener and on the characteristics of the children with functional vision impairments. [less ▲]

Teacher-Student-Relationships and Student Outcomes in Heterogeneous Educational Settings: A Systematic Review of Meta-Analyses

Scientific Conference (2022, November 09)

Especially in diverse educational settings, positive relationships between students and their teachers can foster students’ learning and help alleviate systematic inequalities. Characterized by emotional ... [more ▼]

Especially in diverse educational settings, positive relationships between students and their teachers can foster students’ learning and help alleviate systematic inequalities. Characterized by emotional warmth or closeness, positive teacher-student relationships (TSR) can improve several student outcomes. For instance, existing meta-analyses suggest significant links between TSR and students’ peer relations, school engagement, academic achievement, emotions, executive functions, general well-being, and reductions in aggressive or disruptive behaviors. However, the evidence on these links is scattered, and a comprehensive overview of the associations with TSR integrating academic, behavioral, socio-emotional, motivational, and general cognitive outcomes is lacking. Furthermore, researchers have been unequivocal about possible moderators, such as how these relationships vary with student age or gender. In light of these research gaps, we systematically reviewed the meta-analytic literature and examined (a) the extent to which academic, behavioral, socio-emotional, motivational, and general cognitive student outcomes are related to TSR in the meta-analytic literature; (b) which moderators influence this association; and (c) the methodological quality of the included meta-analyses. We included meta-analyses with preschool or K-12 samples in our dataset which reported some measure of the relation between TSR and student outcomes. With this dataset, we systematically mapped the evidence on (a) the TSR-outcome relationship; (b) the moderators; and (c) the methodological quality of the meta-analyses. We will present our core findings and discuss future research with this second-order, meta-analytic dataset and the impact of positive TSR in diverse and heterogeneous settings. [less ▲]

Integration of backscatter communication with multi-cell NOMA: a spectral efficiency optimization under imperfect SIC

Poster (2022, November 03)

Future wireless networks are expected to connect large-scale low-powered communication devices using the available spectrum resources. Backscatter communications (BC) is an emerging technology towards ... [more ▼]

Future wireless networks are expected to connect large-scale low-powered communication devices using the available spectrum resources. Backscatter communications (BC) is an emerging technology towards battery-free transmission in future wireless networks by leveraging ambient radio frequency (RF) waves that enable communications among wireless devices. Non-orthogonal multiple access (NOMA) has recently drawn significant attention due to its high spectral efficiency. The combination of these two technologies can play an important role in the development of future networks. This paper proposes a new optimization approach to enhance the spectral efficiency of nonorthogonal multiple access (NOMA)-BC network. Our framework simultaneously optimizes the power allocation of base station and reflection coefficient (RC) of the backscatter device in each cell under the assumption of imperfect signal decoding. The problem of spectral efficiency maximization is coupled on power and RC which is challenging to solve. To make this problem tractable, we first decouple it into two subproblems and then apply the decomposition method and Karush-Kuhn-Tucker conditions to obtain the efficient solution. Numerical results show the performance of the proposed NOMA-BC network over the pure NOMA network without BC. [less ▲]

Magnetic nanoprecipitates and interfacial spin disorder in zero-field-annealed Ni50Mn45In5 Heusler alloys as seen by magnetic small-angle neutron scattering

Scientific Conference (2022, November 02)

Secure and Distributed Assessment of Privacy-Preserving Releases of GWAS

in ACM/IFIP International Middleware Conference (2022, November)

Genome-wide association studies (GWAS) identify correlations between the genetic variants and an observable characteristic such as a disease. Previous works presented privacy-preserving distributed ... [more ▼]

Genome-wide association studies (GWAS) identify correlations between the genetic variants and an observable characteristic such as a disease. Previous works presented privacy-preserving distributed algorithms for a federation of genome data holders that spans multiple institutional and legislative domains to securely compute GWAS results. However, these algorithms have limited applicability, since they still require a centralized instance to decide whether GWAS results can be safely disclosed, which is in violation to privacy regulations, such as GDPR. In this work, we introduce GenDPR, a distributed middleware that leverages Trusted Execution Environments (TEEs) to securely determine a subset of the potential GWAS statistics that can be safely released. GenDPR achieves the same accuracy as centralized solutions, but requires transferring significantly less data because TEEs only exchange intermediary results but no genomes. Additionally, GenDPR can be configured to tolerate all-but-one honest-but-curious federation members colluding with the aim to expose genomes of correct members. [less ▲]

Development of a test battery to diagnose specific learning disorder in mathematics in a multilingual education context

Scientific Conference (2022, November)

Robust Techniques for Building Footprint Extraction in Aerial Laser Scanning 3D Point Clouds

in Robust Techniques for Building Footprint Extraction in Aerial Laser Scanning 3D Point Clouds (2022, November)

The building footprint is crucial for a volumetric 3D representation of a building that is applied in urban planning, 3D city modeling, cadastral and topographic map generation. Aerial laser scanning (ALS ... [more ▼]

The building footprint is crucial for a volumetric 3D representation of a building that is applied in urban planning, 3D city modeling, cadastral and topographic map generation. Aerial laser scanning (ALS) has been recognized as the most suitable means of large-scale 3D point cloud data (PCD) acquisition. PCD can produce geometric detail of a scanned surface. However, it is almost impossible to get point clouds without noise and outliers. Besides, data incompleteness and occlusions are two common phenomena for PCD. Most of the existing methods for building footprint extraction employ classification, segmentation, voting techniques (e.g., Hough-Transform or RANSAC), or Principal Component Analysis (PCA) based methods. It is known that classical PCA is highly sensitive to outliers, even RANSAC which is known as a robust technique for shape detection is not free from outlier effects. This paper presents a novel algorithm that employs MCMD (maximum consistency within minimum distance), MSAC (a robust variant of RANSAC) and a robust regression to extract reliable building footprints in the presence of outliers, missing points and irregular data distributions. The algorithm is successfully demonstrated through two sets of ALS PCD. [less ▲]

UX Needs Cards – A Pragmatic Tool to Support Experience Design Through Psychological Needs

in [ ] With Design: Reinventing Design Modes (2022, November)

The psychological needs-driven UX approach is a well-explored area in UX research and a powerful framework for the design of optimal experiences with systems and products. However, the transfer from ... [more ▼]

The psychological needs-driven UX approach is a well-explored area in UX research and a powerful framework for the design of optimal experiences with systems and products. However, the transfer from research to practice is slow and this approach is not yet widely used by practitioners. As card- based methods have been shown to support designers in both the generation of ideas and the evaluation of their designs, we created the UX needs cards as a pragmatic tool able to support a needs-driven UX process. We present the iterative development of the card-set and its associated techniques and report on three use cases, demonstrating the effectiveness of this tool for user research, idea generation and UX evaluation. Our empirical findings suggest that the UX needs cards are a valuable tool able to support design practice, being easily understood by lay users and a source of inspiration for designers. Acting as a tangible translation of a research framework, the UX needs cards promote theory-driven design strategies and provide researchers, designers, and educators with a tool to clearly communicate the framework of psychological needs. [less ▲]

Using Diagnostic Classification Models to map first graders’ cognitive development pathways in the Luxembourgish school monitoring program: a pilot study in the domain of numbers & operations

Scientific Conference (2022, November)

Educational large-scale assessments aim to evaluate school systems’ effectiveness by typically looking at aggregated levels of students’ performance. The developed assessment tools or tests are not ... [more ▼]

Educational large-scale assessments aim to evaluate school systems’ effectiveness by typically looking at aggregated levels of students’ performance. The developed assessment tools or tests are not intended or optimized to be used for diagnostic purposes on an individual level. In most cases, the underlying theoretical framework is based on national curricula and therefore too blurry for diagnostic test construction, and test length is too short to draw reliable inferences on individual level. This lack of individual information is often unsatisfying, especially for participating students and teachers who invest a considerable amount of time and effort, not to speak about the tremendous organizational work needed to realize such assessments. The question remains, if the evaluation could not be used in an optimized way to offer more differentiated information on students’ specific skills. The present study explores the potential of Diagnostic Classification Models (DCM) in this regard, since they offer crucial information for policy makers, educators, and students themselves. Instead of a ranking of, e.g., an overall mathematics ability, student mastery profiles of subskills are identified in DCM, providing a rich base for further targeted interventions and instruction (Rupp, Templin & Henson, 2010; von Davier, M., & Lee, Y. S., 2019). A prerequisite for applying such models is well-developed, and cognitively described items that map the assessed ability on a fine-grained level. In the present study, we drew on 104 items that were developed on base of detailed cognitive item models for basic Grade 1 competencies, such as counting, as well as decomposition and addition with low numbers and high numbers (Fuson, 1988, Fritz & Ricken, 2008, Krajewski & Schneider, 2009). Those items were spread over a main test plus 6 different test booklets and administered to a total of 5963 first graders within the Luxembourgish national school monitoring Épreuves standardisées. Results of this pilot study are highly promising, giving information about different student’s behaviors patterns: The final DCM was able to distinguish between different developmental stages in the domain of numbers & operations, on group, as well as on individual level. Whereas roughly 14% of students didn’t master any of the assessed competencies, 34% of students mastered all of them including addition with high numbers. The remaining 52% achieved different stages of competency development, 8% of students are classified only mastering counting, 15% of students also can master addition with low numbers, meanwhile 20% of students additionally can master decomposition, all these patterns reflect developmental models of children’s counting and concept of numbers (Fritz & Ricken, 2008; see also Braeuning et al, 2021). Information that could potentially be used to substantially enhance large-scale assessment feedback and to offer further guidance for teachers on what to focus when teaching. To conclude, the present results make a convincing case that using fine-grained cognitive models for item development and applying DCMs that are able to statistically capture these nuances in student response behavior might be worth the (substantially) increased effort. References: Braeuning, D. et al (2021)., Long-term relevance and interrelation of symbolic and non-symbolic abilities in mathematical-numerical development: Evidence from large-scale assessment data. Cognitive Development, 58, https://doi.org/10.1016/j.cogdev.2021.101008. Fritz, A., & Ricken, G. (2008). Rechenschwäche. utb GmbH. Fuson, K. C. (1988). Children's counting and concepts of number. Springer-Verlag Publishing. Rupp, A. A., Templin, J. L., & Henson, R. A. (2010). Diagnostic measurement: Theory, methods, and applications. New York, NY: Guildford Press. Von Davier, M., & Lee, Y. S. (2019). Handbook of diagnostic classification models. Cham: Springer International Publishing. [less ▲]

RISC-V Instruction Set Extensions for Lightweight Symmetric Cryptography

in IACR Transactions on Cryptographic Hardware and Embedded Systems (2022, November), 2023(1), 193-237

The NIST LightWeight Cryptography (LWC) selection process aims to standardise cryptographic functionality which is suitable for resource-constrained devices. Since the outcome is likely to have ... [more ▼]

The NIST LightWeight Cryptography (LWC) selection process aims to standardise cryptographic functionality which is suitable for resource-constrained devices. Since the outcome is likely to have significant, long-lived impact, careful evaluation of each submission with respect to metrics explicitly outlined in the call is imperative. Beyond the robustness of submissions against cryptanalytic attack, metrics related to their implementation (e.g., execution latency and memory footprint) form an important example. Aiming to provide evidence allowing richer evaluation with respect to such metrics, this paper presents the design, implementation, and evaluation of one separate Instruction Set Extension (ISE) for each of the 10 LWC final round submissions, namely Ascon, Elephant, GIFT-COFB, Grain-128AEADv2, ISAP, PHOTON-Beetle, Romulus, Sparkle, TinyJAMBU, and Xoodyak; although we base the work on use of RISC-V, we argue that it provides more general insight. [less ▲]

Experimentelle Bewertung der Spannungen und der zugehörigen Implantate bei anterioren Beckenfrakturen vom Typ I

Scientific Conference (2022, October 28)

Improving Machine Learning-based Prediction of Frailty in Elderly People with Digital Wearables : Data from the Berlin Aging Study II (BASE-II)

Poster (2022, October 26)

Frailty is a geriatric medical condition that is highly associated with age and age-related diseases. The multidimensional consequences of frailty are heavily impacting the quality of life, and will ... [more ▼]

Frailty is a geriatric medical condition that is highly associated with age and age-related diseases. The multidimensional consequences of frailty are heavily impacting the quality of life, and will inevitably increase the burden on healthcare systems in the future. Most importantly, the lack of a universal standard to describe, diagnose, or let alone treat frailty, is further complicating the situation in the long-term. Nowadays, more and more frailty assessment tools are being developed on a regional and institutional basis, which is continuing to drive the heterogeneity in the characterization of frailty further apart. Gaining better insights into the underlying causes and pathophysiology of frailty, and how it is developing in patients is, therefore, required to establish strong and accurately tailored response schemes for frail patients, where currently only symptoms are treated. Thus, in this study, we deployed machine learning-based classification and optimization techniques to predict frailty in elderly people aged 65 or above from the Berlin Aging Study II (BASE-II, n=1512, frail=484) and revealed some of the most informative biomedical information to characterize frailty, including new potential biomarkers. Frailty in BASE-II was measured by the Fried et al. 5-item frailty index, composed of the clinical variables grip strength, weight loss, exhaustion, physical activity, and gait. The level of frailty in BASE-II was adapted for binary classification purposes by merging the pre-frail and frail levels as frail. A configurable in-house pipeline was developed for pre-processing the clinical data and predicting the target disease by deploying Support Vector Machines Classification. The most informative and essential subgroup of clinical measurements with regards to frailty was investigated by re-optimizing an initially full data-driven model by sequentially leaving out one subgroup. The best prediction power was yielded with resampling and dimensionality reduction techniques using the F-beta-2 score, and was further improved by adding one item of the Fried et al. frailty index. Furthermore, differences between the gender in the data set led to the investigation of gender-specific model configurations, followed by re-optimizations. As a result, we were able to specifically increase the predictive power in gender-specific groups, and will simultaneously emphasize on the differences between the most informative clinical biomarkers as well as the most essential subgroups for mixed and gender-specific BASE-II. The results herein suggest that a combination of the detected easy-to-obtain biomedical information on frailty risk factors together with one Fried et al. phenotype information provided by i.e., smart wearable devices (gait, grip strength, …) could significantly improve the frailty prediction power in mixed and gender-specific clinical cohort data. [less ▲]

Advertising media artifacts and their impact in the French youth magazine “Salut les Copains” (1960s)

Scientific Conference (2022, October 21)

Presenter: Testimonies from the Russian Invasion of Ukraine

Scientific Conference (2022, October 20)

Co-Organiser: Voices from the War – Path to Peace: Ukrainian and International Insights

Scientific Conference (2022, October 20)

“Challenge accepted”. The many sources to catch the history of virality and memes

Scientific Conference (2022, October 20)

Gifs and memes (Kaplan and Nova, 2016), “buzz” on the Web and social networks are inherent to digital cultures since the very first steps of the Web (i.e., Godwin’s Law, Dancing babies, Hamster Dance, cf ... [more ▼]

Gifs and memes (Kaplan and Nova, 2016), “buzz” on the Web and social networks are inherent to digital cultures since the very first steps of the Web (i.e., Godwin’s Law, Dancing babies, Hamster Dance, cf. McGrath, 2019). Virality has developed and changed over time, may it be related to forms (macro images, videos, etc.) and platforms (YouTube, 4Chan, Twitter, TikTok, etc.), audiences, curation and dissemination (with features encouraging spreadability within social platforms), etc., while relying on some patterns that were identified by Shifman (2014), Milner (2018), Jenkins (2009) and others. However, history and diachronic approaches still remain underrepresented in studies of online virality, although Finn Brunton’s Spam, Jason Eppink’s visual history of gifs (2014), or the Memes entry in The Sage Handbook of Web History (McGrath, 2019) can be mentioned. Historicizing virality through times, spaces and platforms is at the heart of the Hivi project at C2DH, University of Luxembourg (https://hivi.uni.lu). While starting to historicize these “Internet phenomena”, may it be Numa Numa Guy, Leave Britney Alone, Grumpy Cat, the Harlem Shake, Distracted Boyfriends, etc., challenges related to sources become more and more obvious: researchers have to deal with ephemerality as well as data overload, with several spaces of heritagization on the live and archived web, with gaps, silences and noises, issues of searchability in web archives, etc. This presentation focused on a case study, the Harlem Shake, to first demonstrate the variety of sources and spaces (physical and digital) that may be used to retrieve and rebuild this phenomenon (i.e., press, audiovisual content, archived web in several institutions, live web and platforms, etc.). It then presented the challenges related to this kind of reconstruction that is also strongly intertwining vernacular and commercial cultures; sound, video, textual contents; local as well as international spaces, etc. [less ▲]

Retrieving traces of the Luxembourg WebSphere through its first websites

Scientific Conference (2022, October 18)

Hybrid Beamforming Design for OFDM Dual-Function Radar-Communication System with Double-Phase-Shifter Structure

in 2022 30th European Signal Processing Conference (EUSIPCO) (2022, October 18)

In this paper, the problem of the hybrid beamforming (HBF) for a millimeter wave (mmWave) orthogonal frequency division multiplexing (OFDM) dual-function radar-communication (DFRC) system in the presence ... [more ▼]

In this paper, the problem of the hybrid beamforming (HBF) for a millimeter wave (mmWave) orthogonal frequency division multiplexing (OFDM) dual-function radar-communication (DFRC) system in the presence of signal-dependent interference is studied. The HBF network is based on the subarray connection architecture combining with the double-phase-shifter (DPS) structure. To achieve the dual functionality, we formulate the problem by maximizing the communication spectral efficiency subject to the constraints of radar integrated side-lobe to main-lobe ratio (ISMR), space-frequency nulling (SFN) and energy. An efficient algorithm based on the consensus alternating direction method of multipliers (CADMM) frame-work is developed to tackle the resultant nonconvex problem. Simulation results demonstrate the superiority of the proposed DPS structure and HBF algorithm. [less ▲]

Let’s talk about web archiving … three institutions, many possibilities

Scientific Conference (2022, October 18)

This presentation focused on three oral interviews I conducted during the COVID crisis, respectively with the BnL (Bibliothèque nationale du Luxembourg, Els, 2020) in Luxembourg and with INA (Institut ... [more ▼]

This presentation focused on three oral interviews I conducted during the COVID crisis, respectively with the BnL (Bibliothèque nationale du Luxembourg, Els, 2020) in Luxembourg and with INA (Institut national de l’audiovisuel, Schafer, 2020b) and BnF (Bibliothèque nationale de France, Gebeil et al., 2020) in France, to document their web archiving practices and choices during the pandemic. Oral histories not only document the collections and often hidden practices of crawling, selecting, curating and preserving data. They also provide a lot of information on living collections, on the challenges at stake and on human participation in this process. It also enlightens values and governance of web archives and web archiving practices (Schafer and Winters, 2021). Moreover, documenting web archiving is necessary for the current and future work of researchers and may help them to better understand their datasets, the representativeness of collections, bias and limits as well as the strengths of these web archives. Our presentation first compared the practices in the three institutions we selected as case studies for this presentation, in terms of perimeters, curation, stakeholders, targets - INA being a specific case as it focused more precisely on Twitter and retrieved data from the Twitter API, while the BnL and BnF targeted websites more widely (and some social networks but in a less systematic way). We also explained how these oral histories may help to better understand the shaping of web archives. We finally gave several concrete examples of the usefulness of this material for researchers who conduct research on web archives, and more specifically on the COVID crisis, in terms of transnational approaches, and silences and noises in web archives (Brügger, 2018), etc. [less ▲]

Automatic Repair and Deadlock Detection for Parameterized Systems

in Automatic Repair and Deadlock Detection for Parameterized Systems (2022, October 15)

Agile Systems Engineering for sub-CubeSat scale spacecraft

in Proceedings of the International Astronautical Congress, IAC22 (2022, October 14)

Space systems miniaturization has been increasingly popular for the past decades, with over 1600 CubeSats and 300 sub-CubeSat sized spacecraft estimated to have been launched since 1998. This trend ... [more ▼]

Space systems miniaturization has been increasingly popular for the past decades, with over 1600 CubeSats and 300 sub-CubeSat sized spacecraft estimated to have been launched since 1998. This trend towards decreasing size enables the execution of unprecedented missions in terms of quantity, cost and development time, allowing for massively distributed satellite networks, and rapid prototyping of space equipment. Pocket-sized spacecraft can be designed in-house in less than a year and can reach weights of less than 10g, reducing the considerable effort typically associated with orbital flight. However, while Systems Engineering methodologies have been proposed for missions down to CubeSat size, there is still a gap regarding design approaches for picosatellites and smaller spacecraft, which can exploit their potential for iterative and accelerated development. In this paper, we propose a Systems Engineering methodology that abstains from the classic waterfall-like approach in favor of agile practices, focusing on available capabilities, delivery of features and design "sprints". Our method, originating from the software engineering disciplines, allows quick adaptation to imposed constraints, changes to requirements and unexpected events (e.g. chip shortages or delays), by making the design flexible to well-defined modifications. Two femtosatellite missions, currently under development and due to be launched in 2023, are used as case studies for our approach, showing how miniature spacecraft can be designed, developed and qualified from scratch in 6 months or less. We claim that the proposed method can simultaneously increase confidence in the design and decrease turnaround time for extremely small satellites, allowing unprecedented missions to take shape without the overhead traditionally associated with sending cutting-edge hardware to space. [less ▲]

On the (alleged) disappearance of repair since the 1970s

Scientific Conference (2022, October 14)

Nvidia Omniverse for Active Space Debris Removal Missions, an Overview

Scientific Conference (2022, October 13)

Earth orbits have an increasingly worrying space debris pollution problem caused by millions of human-made objects left in space. These are becoming a hazard for current and future space missions. Many ... [more ▼]

Earth orbits have an increasingly worrying space debris pollution problem caused by millions of human-made objects left in space. These are becoming a hazard for current and future space missions. Many solutions to deal with space debris problems have been proposed, including Active Space Debris Removal (ASDR) methods. In this thriving field, various technologies are under development, among them, systems based on tethers, nets, lasers, or robotic arms can be found. However, testing such systems on earth is challenging, recreating space-like conditions, such as accurate contact dynamics under microgravity, is particularly difficult. Nonetheless, it is of paramount importance to offer testing environments for clean space technologies, as space is unforgiving, and space devices must go through thorough evaluation processes to ensure peak efficiency. The HELEN project aims at fulfilling this very need. Building on one of the most advanced simulation frameworks, it will provide photo-realistic rendering, an accurate physical simulation of the space environment, and eventually, through Hardware-In-the-Loop (HIL), simulation of microgravity in ground facilities. This project is the result of the collaboration between SpaceR (University of Luxembourg), and Spacety (Industry). This simulation will be used to test FlexeS, an ASDR capturing system, which is under development. In HELEN, the accuracy of the physics is particularly important, as FlexeS will be validated through simulated HIL scenarios. Hence, a lifelike depiction of the microgravity environment, as well as the collisions, is critical. Moreover, to intercept and grab the debris FlexeS will rely on computer vision algorithms, thus photo-realistic graphics, allowing for lifelike visualizations are required. Furthermore, for future HIL testing, the ROS bridge and real-time communication capacity are crucial to connect the virtual world with the Zero-G robotic facility of the University of Luxembourg. In such a manner, FlexeS will be visualized in the space surroundings while simultaneously undergoing hardware experiments. With all these constraints in mind, Nvidia's Issac Sim was selected to create on-orbit dynamic scenarios. It not only meets all the requirements above but also provides a variety of sensors. Consequently, HELEN is creating on-orbit simulations featuring a CubeSat embedded with FlexeS, and debris circling the Earth. The scenarios showcase the digital twin of the capturing system intercepting debris, corresponding to the approaching phase in ASDR missions. Visually speaking, the RTX render engine allows for photo-realistic image generation. Regarding the motion of these objects, force-based astrodynamics is implemented into the simulation following the gravitational equation. Faithful velocities, position, and contacts are inferred by Nvidia's physics engine, PhysX. Scaled real-life values are used for the mass, as well as the orbital velocity and altitude. Thus, accurate simulations of contact dynamics between the system and the debris can be achieved. In the future, using a ROS bridge, the simulation will be connected to the HIL testing system of the Zero-G facility, amounting to a wholesome ASDR testing framework. Overall, the realistic simulations created with Isaac Sim are promising for analyzing clean space technologies. They combine photo-realistic scenes, accurate physics, and in the future, a means to test real hardware systems. [less ▲]

Concept of an Active Debris Removal 2-step capturing system for small satellites in Low Earth Orbit

Scientific Conference (2022, October 12)

Space debris 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 human-related ... [more ▼]

Space debris 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 human-related space missions. Despite being extremely challenging, catching autonomously and harmlessly an uncooperative object tumbling at high velocity demand reliability, compliance, and robustness. Grasping an object in microgravity means having control during the impact, but also keeping the link between the chaser satellite and the debris secure enough to handle the deorbiting phase. Supposing that the GNC installed tackles the synchronization with the debris rotation, so that only a linear translation is necessary to capture, three main problems can occur. The first problem can occur at the impact between the servicer and the debris. Due to the motion-reaction law, the debris could be pushed away if the capturing system does not prevent that motion. Besides, a high stiffness of the system, added to an unexpected strong impact, could damage either the servicer and/or the debris, resulting in a mission failure. Moreover, the need for a secure attach is required to go-on with the deorbit phase without losing the debris. That’s why, thanks to the fruitful collaboration between industry and academia (Spacety Luxembourg - SpaceR research group at the University of Luxembourg), a cutting-edge concept of a two-step capturing mechanism is being designed. Data analysis of trackable objects in LEO reveals an abundant number of CubeSat-shaped satellites, that future constellations might also take advantage of. Consequently, the concept presented is focusing on capturing these, at their end of life. A first ‘soft capture’ ensures that the debris is received softly while dampening any vibrations generated. A gecko-inspired adhesive surface will first receive the debris, preventing it from being pushed away. The property of such dry adhesive is that they do not require a high preload to stick to the surface, while having a very strong adhesion. To absorb most of the vibrations or movements due to the first impact, a compliant mechanism will be integrated behind the adhesive part. To that extent, if the alignment is not perfect, the system has some degrees of freedom, so that no damage can be generated. This compliant and sticky system would prevent the first main two issues of capturing an uncooperative target in microgravity. Then, a ‘hard capture’ secures the debris so that it would be deorbited without being released on the way. This part of the system would either gently squeeze the debris, using controlled adhesive flexible arms, or encircle it, and would be designed in compliance of ESA guidelines for demise. A two-step capturing mechanism is here proposed, taking advantage of bio-inspired dry adhesive technology, and compliant mechanisms, while having ESA guidelines in mind. Bringing the advantage of removing a vast range of objects in orbit, it also allows a reliable capturing, removing risks of generating more debris. Later works would bring attention to architecture that would fit more than a box shape. [less ▲]

Measuring COVID-19 Vaccine Hesitancy: Consistency of Social Media with Surveys

in Proceedings of the 2022 International Conference on Social Informatics (2022, October 12)

Machine learning-based prediction of frailty in elderly people : Data from the Berlin Aging Study II (BASE-II)

Poster (2022, October 09)

Frailty is a geriatric medical condition that is highly associated with age and age-related diseases. The multidimensional consequences of frailty are heavily impacting the quality of life, and will ... [more ▼]

Frailty is a geriatric medical condition that is highly associated with age and age-related diseases. The multidimensional consequences of frailty are heavily impacting the quality of life, and will inevitably increase the burden on healthcare systems in the future. Most importantly, the lack of a universal standard to describe, diagnose, or let alone treat frailty, is further complicating the situation in the long-term. Nowadays, more and more frailty assessment tools are being developed on a regional and institutional basis, which is continuing to drive the heterogeneity in the characterization of frailty further apart. Gaining better insights into the underlying causes and pathophysiology of frailty, and how it is developing in patients is, therefore, required to establish strong and accurately tailored response schemes for frail patients, where currently only symptoms are treated. Thus, in this study, we deployed machine learning-based classification and optimization techniques to predict frailty in the Berlin Aging Study II (BASE-II, N=1512, frail=484) and revealed some of the most informative biomedical information to characterize frailty, including new potential biomarkers. Frailty in BASE-II was measured by the Fried et al. 5-item frailty index, composed of the clinical variables grip strength, weight loss, exhaustion, physical activity, and gait. The level of frailty in BASE-II was adapted for binary classification purposes by merging the pre-frail and frail levels as frail. A configurable in-house pipeline was developed for pre-processing the clinical data, predicting the target disease, and determining the most informative subgroup of clinical measurements with regards to frailty. The best prediction power was yielded with resampling and dimensionality reduction techniques using the F-beta-2 score, and was further increased by adding one item of the Fried et al. frailty index. We suggest that a combination of the easy-to-obtain biomedical information on frailty risk factors together with one Fried et al. phenotype information provided by i.e. smart wearable devices (gait, grip strength, . . . ) could significantly improve the frailty prediction power. [less ▲]

3D Modelling for AR and 3D printing in Teacher Training

Scientific Conference (2022, October 07)

School activities integrating students’ environments into teaching aim to develop skills and strategies to solve problems in real-world situations and can be useful in hybrid teaching. Such activities can ... [more ▼]

School activities integrating students’ environments into teaching aim to develop skills and strategies to solve problems in real-world situations and can be useful in hybrid teaching. Such activities can encourage and motivate exploring skills in Science, Technology, Engineering, Arts, and Mathematics (STEAM). Hybrid teaching usually uses technologies and connects virtual and physical worlds. We use technologies like 3D modelling for Augmented Reality (AR) or 3D printing with GeoGebra and created an exercise introducing them in a lecture for pre-service mathematics students. The exercise combines the possibility to introduce these technologies, can be used in hybrid teaching and connects to the Austrian mathematics curriculum. The exercise consists of 3D modelling mathematical mazes that can be explored using AR on handheld devices and can also be 3D printed. We used it in online, offline and hybrid scenarios with pre- and in-service teachers and will show resulting presentations of teacher projects. [less ▲]

Augmented Reality in primary education: New learning opportunities for students with learning difficulties in mathematics education

Scientific Conference (2022, October 06)

Although there are manifold connections between mathematics, foremost geometry, and the real-world (e.g., architecture, arts, functional objects), integration seldom happens in daily learning lessons in ... [more ▼]

Although there are manifold connections between mathematics, foremost geometry, and the real-world (e.g., architecture, arts, functional objects), integration seldom happens in daily learning lessons in mathematics primary education. Learning three-dimensional geometric shapes, for example, is mainly done in a two-dimensional setting using textbooks instead of three-dimensional settings using technology or didactical material. This circumstance, however, makes it far more difficult for students with learning difficulties in mathematics to understand mathematical properties, recognize shapes in the real world, and understand the possibilities of modulating shapes. Students with learning difficulties learn efficient strategies to apply mathematics to their environment when shapes and connections are visualized with Augmented Reality within the real world. Based on several experiences and studies, we will present and discuss learning mathematics with Augmented Reality in primary education for students with learning difficulties. [less ▲]

Etude PAN-VAL: le vieillissement actif dans le contexte de la diversité culturelle au Luxembourg

Scientific Conference (2022, October 05)

The Devil is in the Details: Unwrapping the Cryptojacking Malware Ecosystem on Android

in 2022 IEEE 22nd International Working Conference on Source Code Analysis and Manipulation (SCAM) (2022, October)

This paper investigates the various technical and non-technical tools and techniques that software developers use to build and disseminate crypto mining apps on Android devices. Our study of 346 potential ... [more ▼]

This paper investigates the various technical and non-technical tools and techniques that software developers use to build and disseminate crypto mining apps on Android devices. Our study of 346 potential Android mining apps, collected between April 2019 and May 2022, has revealed the presence of more than ten mining apps on the Google Play Store, with at least half of those still available at the time of writing this (June 2022). We observed that many of those mining apps do not conceal their usage of the device’s resource for mining which is considered a violation of the store’s policies for developers. We estimate that more than ten thousand users have run mining apps downloaded directly from the Google Play Store, which puts the supposedly ”stringent” vetting process into question. Furthermore, we prove that covert mining apps tend to be embedded into supposedly free versions of premium apps or pose as utility apps that provide valuable features to users. Finally, we empirically demonstrate that cryptojacking apps’ resource consumption and malicious behavior could be insignificant. We presume that typical users, even though they might be running a mobile antivirus solution, could execute a mining app for an extended period without being alerted. We expect our results to inform the various actors involved in the security of Android devices against the lingering threat of cryptojacking and help them better assess the problem. [less ▲]

PEELER: Learning to Effectively Predict Flakiness without Running Tests

in Proceedings of the 38th IEEE International Conference on Software Maintenance and Evolution (2022, October)

—Regression testing is a widely adopted approach to expose change-induced bugs as well as to verify the correctness/robustness of code in modern software development settings. Unfortunately, the ... [more ▼]

—Regression testing is a widely adopted approach to expose change-induced bugs as well as to verify the correctness/robustness of code in modern software development settings. Unfortunately, the occurrence of flaky tests leads to a significant increase in the cost of regression testing and eventually reduces the productivity of developers (i.e., their ability to find and fix real problems). State-of-the-art approaches leverage dynamic test information obtained through expensive re-execution of test cases to effectively identify flaky tests. Towards accounting for scalability constraints, some recent approaches have built on static test case features, but fall short on effectiveness. In this paper, we introduce PEELER, a new fully static approach for predicting flaky tests through exploring a representation of test cases based on the data dependency relations. The predictor is then trained as a neural network based model, which achieves at the same time scalability (because it does not require any test execution), effectiveness (because it exploits relevant test dependency features), and practicality (because it can be applied in the wild to find new flaky tests). Experimental validation on 17,532 test cases from 21 Java projects shows that PEELER outperforms the state-of-the-art FlakeFlagger by around 20 percentage points: we catch 22% more flaky tests while yielding 51% less false positives. Finally, in a live study with projects in-the-wild, we reported to developers 21 flakiness cases, among which 12 have already been confirmed by developers as being indeed flaky. [less ▲]

kCV-B: Bootstrap with Cross-Validation for Deep Learning Model Development, Assessment and Selection

in kCV-B: Bootstrap with Cross-Validation for Deep Learning Model Development, Assessment and Selection (2022, October)

This study investigates the inability of two popular data splitting techniques: train/test split and k-fold cross-validation that are to create training and validation data sets, and to achieve sufficient ... [more ▼]

This study investigates the inability of two popular data splitting techniques: train/test split and k-fold cross-validation that are to create training and validation data sets, and to achieve sufficient generality for supervised deep learning (DL) methods. This failure is mainly caused by their limited ability of new data creation. In response, the bootstrap is a computer based statistical resampling method that has been used efficiently for estimating the distribution of a sample estimator and to assess a model without having knowledge about the population. This paper couples cross-validation and bootstrap to have their respective advantages in view of data generation strategy and to achieve better generalization of a DL model. This paper contributes by: (i) developing an algorithm for better selection of training and validation data sets, (ii) exploring the potential of bootstrap for drawing statistical inference on the necessary performance metrics (e.g., mean square error), and (iii) introducing a method that can assess and improve the efficiency of a DL model. The proposed method is applied for semantic segmentation and is demonstrated via a DL based classification algorithm, PointNet, through aerial laser scanning point cloud data. [less ▲]

Flash, who? On the Obsolescence of Digital Technology and Its Impact on E-learning Applications: A Case Study.

in Proceedings of the XVII Latin American Conference on Learning Technologies (LACLO) (2022, October)

Technology Enhanced Learning has seen a number of technologies during its history, from instructional video cassettes to smartphones and virtual reality environments. Inevitably, with technologies getting ... [more ▼]

Technology Enhanced Learning has seen a number of technologies during its history, from instructional video cassettes to smartphones and virtual reality environments. Inevitably, with technologies getting obsolete due to replacement or lack of support, TEL solutions face the issue of becoming non-functional. In addition, limited resources may force faculties to abandon certain solutions instead of recreating them with newer technologies. In this paper, we present a case study of an animal neurophysiology virtual lab that has recently suffered from the technology obsolescence phenomenon, both at software and hardware levels. Most importantly, the end of life of Flash was threatening the continuity of an e-learning course. We analyze the issues they were facing, establish a list of requirements for a possible solution and present the implemented changes. We finally perform a risk analysis of obsolescence for the technologies used in the new version of the virtual lab. [less ▲]

OpenAirInterface as a platform for 5G-NTN Research and Experimentation

in IEEE Future Networks World Forum (2022, October)

Technical advancements and experimental works for the integration of 5G and Non-Terrestrial Networks (NTN) have gained significant traction over the past few years. NTN components have been officially ... [more ▼]

Technical advancements and experimental works for the integration of 5G and Non-Terrestrial Networks (NTN) have gained significant traction over the past few years. NTN components have been officially included in the 5G ecosystem by 3GPP in the latest Release-17. 5G-NTN research is ongoing and it is desirable to have a platform that facilitates quick prototyping of the proof-of-concept methods. OpenAirInterface(OAI) is an open-source experimental yet 3GPP standard-compliant Software Defined Radio (SDR) based protocol stack that has been widely known for implementing 4G/5G technologies. Due to its proven capabilities and flexibility, OAI is currently in the developmental process of integrating adaptations for the 5G-NTN. In this work, we discuss the peculiar features of OAI which are shaping it towards becoming a preferred tool for research and experimentation related to 5G-NTN. We provide details of completed/ongoing 5G-NTN projects leveraging OAI to achieve their objectives. In particular, we discuss 5G-GOA and 5G-LEO where critical adaptations in OAI are being done to support 5G-NTN usecases. Such adaptations enable direct-access between UE and gNB via transparent payload Geostationary (5G-GOA) and Nongeostationary satellites (5G-LEO). Both projects have closely followed 3GPP discussions over 5G-NTN and the adaptations are compliant with the currently frozen 3GPP Release-17. OAI adaptations from both projects will be merged into the main development branch of OAI. We also provide a future roadmap of OAI towards 5G-NTN development. We believe that the pioneering steps taken in the course of the aforementioned projects will establish OAI as a preferred tool for 5G-NTN research and experimentations. [less ▲]