AUSLEGUNG eines BIOMECHANISCHEN TESTSTANDES für das BECKEN einschließlich der MUSKELKRÄFTE des GANGZYKLUS

Scientific Conference (2022, October 28)

Biomechanische Untersuchung zu verschiedenen Verfahren der Stabilisierung von Insuffizienzfrakturen des vorderen Beckenringes

Poster (2022, October 26)

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

Scientific Conference (2022, October 21)

“Small is impactful”. Memes and Politics

Scientific Conference (2022, October 20)

From the Hampster Dance and the Dancing Baby in the second half of the 1990s to the hijacking meme of Bernie and his mittens at the US presidential inauguration or the images of the Evergreen blocked in ... [more ▼]

From the Hampster Dance and the Dancing Baby in the second half of the 1990s to the hijacking meme of Bernie and his mittens at the US presidential inauguration or the images of the Evergreen blocked in the Suez Canal, memes have become in the last twenty years an important part of our digital cultures (Shifman, 2014), whose often absurd, playful, corrosive and viral character cannot hide also multiple political dimensions. To the question "Do Memes have politics", to paraphrase Langdon Winner (1980), the answer is undoubtedly yes and this presentation aims to analyse the many levels of politics and agencies at stake when studying memes and their impact, in terms of digital cultures, governance, curation, sharing (John, 2017), appropriation by several communities, but also writing of their history. The first part of the presentation unfolded several levels of politics, starting with the most obvious (memes address political aspects, see for example Denisova, 2019 or Askanius and Keller, 2021) to the more hidden levels (politics of meme generators, of heritagization platform like Know your Meme (Pettis, 2021), of curation …). Relying on a diachronic approach, from the Godwin Law to Distracted Boyfriend, through Leave Britney Alone, this part aimed to address both complementary sides of these Internet phenomena: memes as political forms and politics of memes, while underlying some economic, gendered, affective dimensions which are part of their impact. We then examined the consequences of the notion of “impact” and “politics” for the shaping of an history of memes, which is at stake in the Hivi (A history of online virality) project, we are currently conducting, may it be in terms of sources, methods (“scalable” and “medium” reading), or topics (notably claiming for a study of circulation and flow (Jenkins, 2009), of processes, of participation (Milner, 2018) and appropriation, beyond a sole semiotic approach of memes). References Tina Askanius, Nadine Keller, “Murder fantasies in memes: fascist aesthetics of death threats and the banalization of white supremacist violence”, Information, Communication & Society, 2021, vol. 0, n° 0, p. 1 18. Anastasia Denisova, Internet memes and society: social, cultural, and political contexts, New York, Routledge, 2019. Nicholas A. John, The age of sharing, Cambridge, Polity Press, 2017. Henry Jenkins, If It Doesn’t Spread, It’s Dead (Part One): Media Viruses and Memes, 2009 (http://henryjenkins.org/blog/2009/02/if_it_doesnt_spread_its_dead_p.html). Ryan Milner, The world made meme: Public conversations and participatory media, Cambridge MA, The MIT Press, 2018. Ben Tadayoshi Pettis, “Know your Meme and the Homogeneization of Web History”, Internet Histories, 2021 (to be soon published). Limor Shifman, Memes in digital culture, Cambridge MA, The MIT Press, 2014. Langdon Winner, “Do artifacts have politics ?”, Daedalus, vol. 109, n°1, 1980, p. 121-136. [less ▲]

“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 ▲]

Special ECREA panel : Rethinking digital sources — making web archives useful for future scholars

Scientific Conference (2022, October 20)

The aim of this panel was to draw attention to the large number of archived web collections, and to rethink the challenges and possibilities that they constitute for studies of past and present mediated ... [more ▼]

The aim of this panel was to draw attention to the large number of archived web collections, and to rethink the challenges and possibilities that they constitute for studies of past and present mediated communication. The point of departure is the international network WARCnet, Web ARChive studies net- work researching web domains and events (warcnet.eu), that is composed of humanities scholars, IT-developers, and web archivists, and that aims at promoting national and transnational research that will help us to understand the history of (trans)national web domains and of transnational events on the web, drawing on the increasingly important digital cultural heritage held in national web archives. [less ▲]

Retrieve me if you can... Women and COVID through Web archives

Scientific Conference (2022, October 18)

The COVID crisis has been a shared worldwide and collective experience from March 2020 and lot of voices have echoed each other, may it be related to grief, lockdown, masks and vaccines, homeschooling ... [more ▼]

The COVID crisis has been a shared worldwide and collective experience from March 2020 and lot of voices have echoed each other, may it be related to grief, lockdown, masks and vaccines, homeschooling, etc. However, this unprecedented crisis has also deepened asymmetries and failures within societies, in terms of occupational fields, economic inequalities, health and sanitary access, and we could extend the inventory of these hidden and more visible gaps that were reinforced during the crisis. Women and gender were also at stake when it came to this sanitary crisis, may it be to discuss the better management of the crisis by female politicians, domestic violence during the lockdown, decreasing production of papers by female research scientists, homeschooling and mental load of women, etc. In December 2021, our AWAC2 team submitted several topics to the IIPC (International Internet Preservation Consortium) community and invited the international organization to select one of them that the team would investigate in depth, based on the unique IIPC Covid collection of web archives. Women, gender and COVID was the winning topic. As a cohort team within the AUT (Archives Unleashed Team) program, the AWAC2 team benefited from a privileged access to this collection, thanks to Archive-It and through ARCH, and from regular mentorship by the AUT team. It allowed us to investigate and analyse this huge collection of 5.3 TB, 161 757 lines for the CSV on domain frequency CSV, 8,738,751 lines for the CSV related to plain text of web pages. Accepting the challenge, the AWAC2 team organized a datathon in March 2022 in Luxembourg to investigate and retrieve the many traces of women, gender and COVID in web archives, while mixing close and distant reading. This panel, chaired by Valérie Schafer, aimed to present this research, entwining technical, epistemological, and methodological issues and challenges with our results. Valérie Schafer began the panel by presenting an overview of the project, including a presentation of the IIPC corpus, of the AUT cohort program and of the research topic. Karin de Wild and Joshgun Sirajzade presented the AUT tools and interfaces, the technical challenges of the corpus, the choices we made (and notably with regards to multilingualism) as well as the tools and methodologies that were used. Finally, Susan Aasman and Sophie Gebeil presented some results and challenges of this research. [less ▲]

Keynote by panel on Looking ahead: after web (archives)?

Scientific Conference (2022, October 18)

Distributed 5G NR-based integrated sensing and communication systems: Frame structure and performance analysis

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

This paper discusses a distributed Integrated Sensing and Communication (ISAC) network based on 5G NR. Each BS in the cellular network adopts half-duplex operation, and every three adjacent BSs construct ... [more ▼]

This paper discusses a distributed Integrated Sensing and Communication (ISAC) network based on 5G NR. Each BS in the cellular network adopts half-duplex operation, and every three adjacent BSs construct a cooperative sensing system. Based on the 5G NR standard frame configuration, we develop a new procedure and protocol to support the proposed ISAC network. Under this network, we analyze the performance of both sensing and communication in practical scenarios. Simulations show the effectiveness of the proposed ISAC network. [less ▲]

Histoire des territoires belges annexés au IIIe Reich

Scientific Conference (2022, October 15)

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

Scientific Conference (2022, October 14)

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 ▲]

Performance Modeling of Weather Forecast Machine Learning for Efficient HPC

in International Conference on Distributed Computing Systems (ICDCS), Italy 10-13 July 2022 (2022, October 13)

High-performance computing is a prime area for many applications. Majorly, weather and climate forecast applications use the HPC system because it needs to give a good result with low latency. In recent ... [more ▼]

High-performance computing is a prime area for many applications. Majorly, weather and climate forecast applications use the HPC system because it needs to give a good result with low latency. In recent years machine learning and deep learning models have been widely used to forecast the weather. However, to the best of the author’s knowledge, many applications do not effectively utilise the HPC system for training, testing, validation, and inference of weather data. Our experiment is to conduct performance modeling and benchmark analysis of weather and climate forecast machine learning models and determine the characteristics between the application, model and the underlying HPC system. Our results will help the researchers improvise and optimise the weather forecast system and use the HPC system efficiently. [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 ▲]

Topology Analysis of the XRP Ledger

Scientific Conference (2022, October 12)

XRP Ledger is one of the oldest, well-established blockchains. Despite the popularity of the XRP Ledger, little is known about its underlying peer-to-peer network. The structural properties of a network ... [more ▼]

XRP Ledger is one of the oldest, well-established blockchains. Despite the popularity of the XRP Ledger, little is known about its underlying peer-to-peer network. The structural properties of a network impact its efficiency, security and robustness. We aim to close the knowledge gap by providing a detailed analysis of the XRP overlay network. In this paper we examine the graph-theoretic properties of the XRP Ledger peer-to-peer network and its temporal characteristics. We crawl the XRP Ledger over two months and collect 1,290 unique network snapshots. We uncover a small group of nodes that act as a networking backbone. In addition, we observe a high network churn, with a third of the nodes changing every five days. Our findings have strong implications for the resilience and safety of the XRP Ledger. [less ▲]

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)

Climate Risk and Price Jumps

Scientific Conference (2022, October)

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 ▲]

Non-Coherent Massive MIMO Integration in Satellite Communication

Scientific Conference (2022, October)

Massive Multiple Input-Multiple Output (mMIMO) technique has been considered an efficient standard to improve the transmission rate significantly for the following wireless communication systems, such as ... [more ▼]

Massive Multiple Input-Multiple Output (mMIMO) technique has been considered an efficient standard to improve the transmission rate significantly for the following wireless communication systems, such as 5G and beyond. However, implementing this technology has been facing a critical issue of acquiring much channel state information. Primarily, this problem becomes more criticising in the integrated satellite and terrestrial networks (3GPP-Release 15) due to the countable high transmission delay. To deal with this challenging problem, the mMIMO-empowered non-coherent technique can be a promising solution. To our best knowledge, this paper is the first work considering employing the non-coherent mMIMO in satellite communication systems. This work aims to analyse the challenges and opportunities emerging with this integration. Moreover, we identified the issues in this conjunction. The preliminary results presented in this work show that the performance measured in bit error rate (BER) and the number of antennas are not far from that required for terrestrial links. Furthermore, thanks to mMIMO in conjunction with the non-coherent approach, we can work in a low signal-to-noise ratio (SNR) regime, which is an excellent advantage for satellite links. [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 ▲]

The EU's Digital Identity Policy: Tracing Policy Punctuations

in Proceedings of the 15th International Conference on Theory and Practice of Electronic Governance (ICEGOV) (2022, October)

This paper analyzes the development of the European Union’s digital identity policy. The analysis focuses on the dynamics leading to a sudden shift from identity management as a sensitive topic under ... [more ▼]

This paper analyzes the development of the European Union’s digital identity policy. The analysis focuses on the dynamics leading to a sudden shift from identity management as a sensitive topic under national competence towards a common, harmonized, user-centric European Digital Identity Framework layering on top of Member States’ existing systems. We adopted a syncretic approach to Punctuated Equilibrium Theory and focused specifically on the concept of policy punctuations and policy image. Process tracing is used as a method to trace and interpret causal mechanisms of policy processes. The empirical analysis is grounded in elite interviews and policy documentation. To open up the black box of policy-making, we analyze and disaggregate the policy process. We thereby provide a better understanding of the historical-political and technological mechanisms that determine particular policy outcomes. [less ▲]

Nanosensor Location in the Human Circulatory System Based on Electric Circuit Representation of Vessels

in Proceedings of the 9th ACM International Conference on Nanoscale Computing and Communication (2022, October)

Nanotechnologies are advancing precision medicine applications, enhancing the detection and treatment of diseases. Traveling through the human vessels, nanosensors are envisioned to locally detect and ... [more ▼]

Nanotechnologies are advancing precision medicine applications, enhancing the detection and treatment of diseases. Traveling through the human vessels, nanosensors are envisioned to locally detect and actuate on targets very efficiently. In this area, modeling the behavior of traveling nanosensors in the human circulatory system helps developing new mechanisms for medical treatments. This paper explores the accurate modeling of the concentration level of the flowing nanosensors in vessels. We use a Markov chain formulation to predict the stationary distribution of them in the variety of vessel segments. To evaluate the transition probabilities of the Markov chain, we compute the blood flow based on the representation of vessels through electric circuit components. The resulting study reveals the dynamics of the movement of nanosensors in the blood flow yielding further details on their concentration level along vessels. [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 ▲]

Children’s perspectives on their learning experiences during the pandemic

Scientific Conference (2022, October)

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 ▲]

When a policy gets implemented: literacy activities in multiple languages in a day care centre in Luxembourg

Scientific Conference (2022, September 29)

The use of media in language teaching

Scientific Conference (2022, September 24)

Multilingual teaching and the promotion of multilingualism among students are important principles of the University of Luxembourg. For their implementation, a variety of e-learning resources are used ... [more ▼]

Multilingual teaching and the promotion of multilingualism among students are important principles of the University of Luxembourg. For their implementation, a variety of e-learning resources are used, adapted to the needs of the learners. We will give an overview of new multimodal communication practices and methods used by learners in multilingual contexts which naturally lead teachers to rethink their approach and incorporate media into their teaching strategies. The hybrid nature of devices (computers, tablets, televisions, smartphones, paper, interactive whiteboards, etc.) and digital tools (document sharing platforms, online correction tools, interactive exercises, online learning programmes, dictionaries, video editing software, automatic pronunciation correction, etc.) offer a great potential to interactive and mobile teaching and learning. We will illustrate this potential by giving an example of how to develop text production competence in Chinese as a foreign language in a motivating way using the content management system Moodle. Our reflection aims at optimising the quality of language teaching both in and out of the classroom. [less ▲]

Methods for increasing the dependability of High-performance, Many-core, System-on-Chips

in Graczyk, Rafal; Memon, Md Saad; Volp, Marcus (Eds.) IAC 2022 congress proceedings, 73rd International Astronautical Congress (IAC) (2022, September 21)

Future space exploration and exploitation missions will require significantly increased autonomy of operation for mission planning, decision-making, and adaptive control techniques. Spacecrafts will ... [more ▼]

Future space exploration and exploitation missions will require significantly increased autonomy of operation for mission planning, decision-making, and adaptive control techniques. Spacecrafts will integrate new processing and compression algorithms that are often augmented with machine learning and artificial intelligence capabilities. This functionality will have to be provided with high levels of robustness, reliability, and dependability for conducting missions successfully. High-reliability requirements for space-grade processors have led to trade-offs in terms of costs, energy efficiency, and performance to obtain robustness. However, while high-performance / low-robustness configurations are acceptable in the Earth's vicinity, where assets remain protected by the planet's magnetosphere, they cease to work in more demanding environments, like cis-lunar or deep space, where high-energy particles will affect modern components heavily, causing temporary or permanent damage and ultimately system failures. The above has led to a situation where state-of-the-art processing elements (processors, co-processors, memories, special purpose accelerators, and field-programmable-gate arrays (FPGAs), all possibly integrated into System-on-a-Chip (SoC) designs) are superior to their high reliability, space-qualified counterparts in terms of processing power or energy efficiency. For example, from modern, state-of-the-art (SOTA) devices, one can expect a 2-3 order-of-magnitude performance per Watts improvement over space-grade equipment. Likewise, one finds a gap of approximately nine technology nodes between devices, which translates into a factor 25 decrease in operations per Watts. In this paper, we demonstrate how to utilize part of this enormous performance advantage to increase the robustness and resilience of otherwise susceptible semiconductor devices while harnessing the remaining processing power to build affordable space systems capable of hosting the compute-intensive functionality that future space missions require. We are bridging this performance-reliability gap by researching the enabling building blocks for constructing reliable and secure, space-ready Systems-on-a-Chip from SOTA processing elements. [less ▲]

Monitoring and Early Detection of Wildfires Using Multiple-payload Fractionated Spacecraft

Scientific Conference (2022, September 20)

The paper discusses the deployment of multiple-payload fractionated spacecraft as a surveillance system for autonomously monitoring and detecting wildfires at early stages in any area on the Earth’s ... [more ▼]

The paper discusses the deployment of multiple-payload fractionated spacecraft as a surveillance system for autonomously monitoring and detecting wildfires at early stages in any area on the Earth’s surface. The fractionated system, consisting of 12 operational CubeSats, four reserved CubeSats, and one Mothership, acquires images in 13 spectral bands within the visible, near infrared, and short-wave infrared regions with high spatial resolutions. A dynamic fire-hazard index is introduced, based on geographic coordinates, environmental parameters, and weather conditions, to prioritize the areas for the probability of wildfires. Then, a convolutional neural network is designed to identify potentially hazardous areas and detect the early stages of wildfire spots. The detection method is based on the processed images and geographic locations as well as measurements of thermal anomalies, smoke, and unusual variations of regional atmospheric conditions. The effectiveness of the surveillance system is examined through several case studies using numerical simulations. [less ▲]

Machine learning applied to higher order functional representations of omics data reveals biological pathways associated with Parkinson‘s Disease

Poster (2022, September 18)

Background: Despite the increasing prevalence of Parkinson’s Disease (PD) and research efforts to understand its underlying molecular pathogenesis, early diagnosis of PD remains a challenge. Machine ... [more ▼]

Background: Despite the increasing prevalence of Parkinson’s Disease (PD) and research efforts to understand its underlying molecular pathogenesis, early diagnosis of PD remains a challenge. Machine learning analysis of blood-based omics data is a promising non-invasive approach to finding molecular fingerprints associated with PD that may enable an early and accurate diagnosis. Description: We applied several machine learning classification methods to public omics data from PD case/control studies. We used aggregation statistics and Pathifier’s pathway deregulation scores to generate higher order functional representations of the data such as pathway-level features. The models’ performance and most relevant predictive features were compared with individual feature level predictors. The resulting diagnostic models from individual features and Pathifier’s pathway deregulation scores achieve significant Area Under the Curve (AUC, a receiver operating characteristic curve) scores for both cross-validation and external testing. Furthermore, we identify plausible biological pathways associated with PD diagnosis. Conclusions: We have successfully built machine learning models at pathway-level and single-feature level to study blood-based omics data for PD diagnosis. Plausible biological pathway associations were identified. Furthermore, we show that pathway deregulation scores can serve as robust and biologically interpretable predictors for PD. [less ▲]

Investigating mental health of children in out-of-home care during the COVID-19 pandemic

Scientific Conference (2022, September 16)

A Communal Struggle: Team-Teaching at the University of Luxembourg

Scientific Conference (2022, September 15)

INTRODUCTION Team-teaching, also known as collaborative-teaching, co-teaching and pair-lecturing has been practiced for ages (Buckley 2000). It is generally described as a positive pedagogical practice ... [more ▼]

INTRODUCTION Team-teaching, also known as collaborative-teaching, co-teaching and pair-lecturing has been practiced for ages (Buckley 2000). It is generally described as a positive pedagogical practice that can both enhance learning among students and the experience of teaching among instructors (Plank 2011, 2014). While it is acknowledged that team-teaching is not simple and requires great coordination among instructors, it is presented in gleaming terms for both instructors and students alike. More recent work highlights an increased necessity for collaborative-teaching due to the growing complexity in higher education combined with dwindling resources (Minett-Smith and Davis 2020), or as a deliberate cost-saving measure (Liebel et al. 2017). Yet, little quantitative evidence can be found in the literature showing the positive efficacy of this methodology, relative to Student Evaluation Teaching (SET) measures (for exception see: Carpenter et al. 2007). Thus, this study aims to answer: 1) how prevalent is team-teaching; 2) what are the most common team compositions (number of instructors, gender, instructor status and seniority); 3) are there any significant differences in SET scores relative to differences in composition; and 4) what can we learn from the open-text feedback to help us understand, or contextualize, any quantitative differences found between solo- versus team-taught courses? DATA & METHODS To address our research questions and investigate the contours of team teaching in the Faculty of Humanities, Education and Social Sciences (FHSE) at the University of Luxembourg, we use SET data (course feedback), as an indirect measure of quality of education (Marsh 2007). We use descriptive statistics and regression analysis to examine the quantitative feedback for a total of 2908 courses collected over eight semesters (Winter semester 2015-Summer semester 2019). We compliment these results with content analysis of open-text comments that help us understand and contextualize the quantitative findings. PRELIMINARY RESULTS While course feedback data does not directly measure the quality of learning experienced by students (i.e., whether students learn better in team-taught courses vs. solo instructor courses), it does however shed light on the general sentiment experienced and reported by participating students. Preliminary analyses indicate that approximately 30% of courses are team-taught (60% with two-person teams and 40% with teams of 3 and 4+ instructors). Furthermore, we found that, on average, team-taught courses receive significantly lower ratings from students than solo instructor courses. In the remainder of this article, we analyse this basic finding and discuss the implications for team teaching. [less ▲]

Investigating subjective well-being and mental health of children in out-of-home care during the COVID-19 pandemic

Scientific Conference (2022, September 15)

Modèles de mélanges finis pour une distribution de loi BETA sous-jacente avec une application à des données sur la COVID-19

Scientific Conference (2022, September 14)

Resolving the complex spin structure in Fe-based soft magnetic nanocrystalline material by magnetic small-angle neutron scattering

Scientific Conference (2022, September 13)

3D printed mathematics visualisations by STEAM teachers

Scientific Conference (2022, September 12)

Visualising abstract concepts such as for example geometrical objects in mathematics can be a valuable support for learners. Visualisation, however, is a process involving several steps that influence ... [more ▼]

Visualising abstract concepts such as for example geometrical objects in mathematics can be a valuable support for learners. Visualisation, however, is a process involving several steps that influence each other. Duval (1998) uses steps connecting reasoning by an explanation or proof to a construction step involving tools creating a visualisation to a production of a visual representation leading to new insights about a geometrical object. Vágová (2020) argues that visualising geometrical objects needs the ability to create, manipulate, and transform mental images by an internal and an external representation which both require information about the spatial arrangement. 3D modelled and then visualised geometrical objects can support the development and train visualisation skills. Steps of visualisation processes require visuospatial competencies and are also important for other subjects in Science, Technology, Engineering, Arts and Mathematics (STEAM) education (Ng 2017). Being able to understand representations and their spatial rotations, transitions between 2D and 3D and being able to manipulate representations are valuable for STEAM related subjects (Kok 2020). Martin-Dorta et al. (2008) says that spatial abilities can be improved using real and computer-aided models. 3D printing can therefore be an interesting activity as it also combines the mentioned steps in a mathematical modelling way. This approach was used in a beginners course for pre-service mathematics teachers and some of them chose to create mathematical proofs as visualisation. We will look at 3D printed objects, which concepts they visualise and what teachers' ideas behind visualisations were. [less ▲]

Entre chien et loup de Christiane Jatahy (2021-2022) : un théâtre au présent, témoin des formes contemporaines de fascisme

Scientific Conference (2022, September 09)

Nous entendons nous intéresser à la rencontre qui s’est déroulée, le lundi 7 mars 2022 à 20h au cinéma Mk2 Nation (Paris, 12ème), entre la mettrice en scène brésilienne, Christiane Jatahy, la philosophe ... [more ▼]

Nous entendons nous intéresser à la rencontre qui s’est déroulée, le lundi 7 mars 2022 à 20h au cinéma Mk2 Nation (Paris, 12ème), entre la mettrice en scène brésilienne, Christiane Jatahy, la philosophe Marylin Maeso, autrice de La petite fabrique de l’inhumain et la psychanalyste Clotilde Leguil, venant de publier Céder n’est pas consentir. Cet échange fut dédié à Entre chien et loup, dernier spectacle en date, voulu par l’artiste carioca précitée — à la notoriété grandissante en Europe depuis près de vingt ans — d’après le scénario du film de Lars von Trier : Dogville avec Nicole Kidman dans le rôle-titre de Grace. Cet événement liminaire nous servira à démontrer, à terme, combien cette création se révèle être un théâtre éminemment ancré dans le présent, témoignant de toutes les formes contemporaines de fascisme, par le truchement, précisément, du personnage de Grace, devenu, pour les besoins de la mise en scène, Gracia, jeune femme d’origine brésilienne, interprétée par Julia Bernat, actrice fétiche de Christiane Jatahy grâce à laquelle elle peut faire pleinement entendre sa propre voix d’artiste politiquement engagée. [less ▲]

Translanguaging pedagogy and creative activism for early education in multilingual Luxembourg

Scientific Conference (2022, September 07)

Luxembourg is a highly linguistically and culturally diverse country. In early education, there are 64 % of four-year old children who not speak Luxembourgish at home (MENJE, 2018). From 2017 ... [more ▼]

Luxembourg is a highly linguistically and culturally diverse country. In early education, there are 64 % of four-year old children who not speak Luxembourgish at home (MENJE, 2018). From 2017, multilingual early education is mandatory, which obliges teachers to develop children’s Luxembourgish, familiarizing them with French, and valuing their home languages. Therefore, the present project aimed to: (1) offer an 18-hours professional development (PD) course in translanguaging pedagogy to 40 teachers over 6 months, (2) strengthen home-school collaboration, and (3) support children’s linguistic, socio-emotional, and cognitive development and engagement in the classroom. The results from teacher questionnaires, focus groups, and interviews, showed that there was some positive change regarding the attitudes towards children’s home languages. The interviews with 17 parents indicated that there was a need for more home-school collaboration. The tests in early literacy and numeracy with 23 preschool children over one year, identified that children performed higher in their home languages. The video observations showed that when the teachers used children’s languages in the classroom, this impacted positively their well-being. Following the principles of creative activism, the author produced: (1) the website with over 100 practical activities on how teachers can involve children’s languages and families, (2) the illustrated book Sumak for parents, showing difficulties with integration in a new country, and (3) the illustrated book, Mara’s song for preschool children, showing how Mara finds her way in the new classroom. [less ▲]

Abstracts of the 11th DACH+ Conference on Energy Informatics (S53-Taxonomy of Local Flexibility Markets)

in Energy Informatics (2022, September 07), 5

Flexibility has risen as a potential solution and complement for system operators’ current and future problems (e.g., congestion, voltage) caused by integrating distributed renewable resources (e.g., wind ... [more ▼]

Flexibility has risen as a potential solution and complement for system operators’ current and future problems (e.g., congestion, voltage) caused by integrating distributed renewable resources (e.g., wind, solar) and electric vehicles. In parallel, local flexibility markets (LFM) emerge as a possible smart grid solution to bridge between flexibility-seeking customers and flexibility-offering customers in localized areas. Nevertheless, there is no unique, standard, or simple solution to tackle all the problems system operators and other energy actors face. Therefore, many local flexibility market concepts, initiatives (projects), and companies have developed various solutions over the last few years. At the same time, they increased the complexity of the topic. Thus, this research paper aims to describe several local flexibility market concepts, initiatives (projects), and companies in Europe. To do so, we propose a taxonomy derived from LFMs descriptions. We use the taxonomy-building research method proposed by [1] to develop our taxonomy. Moreover, we use the smart grid architecture model (SGAM) as a structural and foundation guideline. Given the numerous and diverse LFM solutions, we delimit the taxonomy by considering solutions focused on congestion management on medium and low voltage (meta-characteristic). [less ▲]

Applying an Intersectional Lens to Author Composition at Women’s Colleges, Historically Black Colleges and Universities, and Hispanic Serving Institutions in the United States

Scientific Conference (2022, September 07)

Analysis and comparison of gait impairments in patients with Parkinson’s disease and normal pressure hydrocephalus using wearable sensors and machine learning algorithms

Scientific Conference (2022, September 05)

Objectives. Gait impairments in patients with Parkinson’s disease (PD) and normal pressure hydrocephalus (NPH) are visually assessed by movement disorders experts for diagnoses and to decide on ... [more ▼]

Objectives. Gait impairments in patients with Parkinson’s disease (PD) and normal pressure hydrocephalus (NPH) are visually assessed by movement disorders experts for diagnoses and to decide on pharmaceutical and surgical interventions. Despite standardised tests and clinicians’ expertise, such approaches entail a considerable level of subjectivity. The recent development of wearable sensors and machine learning offers complementary approaches providing more objective, quantitative assessments of gait impairments. We aim to employ the data gathered from an inertial measurement unit synchronized with a novel foot pressure sensor embedded in the patient’s shoes to characterize gait impairments. We focus on distinguishing PD from NPH and on assessing gait impairment before and after surgical intervention. Methods. A cohort of 10 PD and 10 NPH patients was assembled and patients performed standardised walking tests. Measurements were performed employing wearable sensors comprising a three-axes gyroscope, a three-axes accelerometer and eight pressure sensors embedded in each patient’s shoe. To analyse the generated data, existing algorithms were implemented and adapted. These allow to compute gait cycle parameters such as step time and metrics characterizing the swing and stance phases. Machine learning algorithms where employed to identify major changes in gait cycle parameters between the two groups of patients, and for individual patients before and after surgical intervention as DBS implantation in PD and Shunt implantation in NPH. Results. The gait impairments of both disease groups were measured and quantified. An algorithm to extract gait cycle parameters from sensors was implemented, tested and employed on such patients. Gait cycle parameters within and between the groups of PD and NPH patients were compared, assessing what gait cycle parameters allow to distinguish between these groups. Gait cycle impairments of patients before and after surgery were compared, assessing the effect of DBS or Shunt implantation and which gait cycle parameters allow to monitor symptoms improvement. Conclusions. Wearable sensors measuring pressure, combined with gait cycle parameters extraction and machine learning algorithms, have a great potential for objective evaluation of gait impairment. In particular, they allow to characterize what differentiate such impairments between PD and NPH patients, and what allow to assess motor symptoms improvement after surgery. [less ▲]

Luxembourg Completing its Space Legislation

in Hofmann, Mahulena (Ed.) Luxembourg Completing its Space Legislation (2022, September)

On January 2021, the general Space Law of Luxembourg entered into force. It complemented the 2017 Law on Space Resources by an authorization regime applicable to the remaining space activities under ... [more ▼]

On January 2021, the general Space Law of Luxembourg entered into force. It complemented the 2017 Law on Space Resources by an authorization regime applicable to the remaining space activities under Luxembourg's jurisdiction. By these steps, the Luxembourg authorities have now at their disposal a full-coverage legal framework capable to authorize all space activities. [less ▲]

The Prosody of Cheering in Sport Events

in Proc. Interspeech 2022 (2022, September)

Motivational speaking usually conveys a highly emotional message and its purpose is to invite action. The goal of this paper is to investigate the prosodic realization of one particular type of cheering ... [more ▼]

Motivational speaking usually conveys a highly emotional message and its purpose is to invite action. The goal of this paper is to investigate the prosodic realization of one particular type of cheering, namely inciting cheering for single addressees in sport events (here, long-distance running), using the name of that person. 31 native speakers of German took part in the experiment. They were asked to cheer up an individual marathon runner in a sporting event represented by video by producing his or her name (1-5 syllables long). For reasons of comparison, the participants also produced the same names in isolation and carrier sentences. Our results reveal that speakers use different strategies to meet their motivational communicative goals: while some speakers produced the runners’ names by dividing them into syllables, others pronounced the names as quickly as possible putting more emphasis on the first syllable. A few speakers followed a mixed strategy. Contrary to our expectations, it was not the intensity that mostly contributes to the differences between the different speaking styles (cheering vs. neutral), at least in the methods we were using. Rather, participants employed higher fundamental frequency and longer duration when cheering for marathon runners. [less ▲]

Radio Regulation Compliance of NGSO Constellations’ Interference towards GSO Ground Stations

in IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 12–15 September 2022, Virtual Conference (2022, September)

The commercial low earth orbiting (LEO) satellite constellations have shown unprecedented growth. Accordingly, the risk of generating harmful interference to the geostationary orbit (GSO) satellite ... [more ▼]

The commercial low earth orbiting (LEO) satellite constellations have shown unprecedented growth. Accordingly, the risk of generating harmful interference to the geostationary orbit (GSO) satellite services increases with the number of satel- lites in such mega-constellations. As the GSO arc encompasses the primary and existing satellite assets providing essential fixed and broadcasting satellite services, the interference avoidance for this area is of the utmost importance. In particular, non- geostationary orbit (NGSO) operators should comply with the regulations set up both by their national regulators and by the International Telecommunications Union (ITU) to minimize the impact of emissions on existing GSO and non-GSO systems. In this paper, we first provide an overview of the most recent radio regulations that dictate the NGSO-GSO spectral co-existence. Next, we analyze the NGSO-GSO radio frequency interference for the downlink scenario, following the so-called time-simulation methodology introduced by ITU. The probability distribution of aggregated power flux-density for NGSO co-channel interference is evaluated and assessed, adopting different degrees of exclusion angle strategy for interference avoidance. We conclude the paper by discussing the resulting implications for the continuity of operation and service provision and we provide remarks for future work [less ▲]

Satellite Beam Densification for High-Demand Areas

in 2022 11th Advanced Satellite Multimedia Systems Conference and the 17th Signal Processing for Space Communications Workshop (ASMS/SPSC) (2022, September)

Conventional multi-beam pattern design in Geostationary (GEO) satellite communication systems consists of a regular grid of non-reconfigurable beams, where the beams overlap is typically assumed at the ... [more ▼]

Conventional multi-beam pattern design in Geostationary (GEO) satellite communication systems consists of a regular grid of non-reconfigurable beams, where the beams overlap is typically assumed at the point where the beam edge reaches a 3-dB loss in the antenna pattern (with respect to the beam center). For certain high demand areas, this 3dB loss has a significant impact. To overcome this issue, in this paper we evaluate the potential gain of beam densification, i.e. considering an increased number of beams (keeping the same beam size and shape) to cover hot-spot areas, with the aim to push the beam overlap and increase the beam gain. In particular, we compare two beam patterns (kindly provided by ESA): One with regular beam grid, and one with densification in a particular hot-spot area. We provide a comparison in terms of per-beam average SINR and capacity, as well as an overall system analysis considering the whole densified region. [less ▲]

Indicators for assessing the necessity of power system flexibility: a systematic review and literature meta-analysis

in Proceedings of the 18th International Conference on the European Energy Market (EEM) (2022, September)

There are different flexibility options to align power systems to volatile feed-in of renewable electricity sources. The flexibility options differ in the dimensions of time, spatiality, and resource type ... [more ▼]

There are different flexibility options to align power systems to volatile feed-in of renewable electricity sources. The flexibility options differ in the dimensions of time, spatiality, and resource type. To make policy decisions on future energy systems, it is necessary to get a top-down indication of how much power system flexibility is needed. With the ongoing energy transition, there is yet no comprehensive overview of indicators that describe which dimension of flexibility will be necessary to what extent for different energy systems. Therefore, this paper provides a first overview of indicators that can be used to assess the necessity of power system flexibility. Thus, we do a systematic literature review to identify indicators that allow us to estimate the necessity of power system flexibility. We conduct a meta-analysis of these indicators and categorize them as indicators that either stand for an increasing or decreasing necessity of power system flexibility. Our paper can help inform policy, assess needed changes to system operations, increase stakeholder acceptance and investor confidence in implementing new technology and measures. [less ▲]

Privacy in Cross-border Digital Currency. A Transatlantic Approach

in Frankfurt Forum on US-European GeoEconomics (2022, September)

As a growing number of countries explore Central Bank Digital Currencies (CBDCs) for the domestic context, multi-country cross-border CBDCs pilots are also proliferating. Cross-border CBDCs could make ... [more ▼]

As a growing number of countries explore Central Bank Digital Currencies (CBDCs) for the domestic context, multi-country cross-border CBDCs pilots are also proliferating. Cross-border CBDCs could make cross-border payments faster, cheaper, and simpler. However, for any cross-border CBDC to unlock these benefits and be widely adopted, it must address key concerns, chief among them risks around privacy and transparency of data. This article illustrates how various technical design choices can affect the privacy and transparency of cross-border CBDCs. For instance, architectural choices about the structure of a cross-border CBDC and representational choices about how transactions are encoded in the underlying software can have far-reaching implications for privacy and transparency—both in a domestic context and for cross-border transactions. Many of the cross-border CBDC pilot studies to date have (understandably) adopted the technical designs provided by enterprise distributed ledger platforms. However, some of these designs make tradeoffs regarding privacy, efficiency, and/or security. Whether these tradeoffs are acceptable is a matter of policy, and requires coordination between different regulators and central banks. In view of these implications—and some of the corresponding tensions that arise—we argue that the US and the EU should work together alongside other partners to create the technological and regulatory environment to enable privacy-preserving cross-border CBDCs. The US and the EU should seize the emergence of CBDCs as an opportunity to finally establish a transatlantic privacy framework, and clarify its interplay with the prevention of money laundering and financing of terrorism (AML/CFT/CPF). More broadly, both should harness the clout of their combined financial systems to develop digital asset regulation and standards with a global reach and democratic values. These regulatory developments would not only streamline regulatory guidelines, but they could also directly impact and ease the technical development of a cross-border CBDC. [less ▲]