Zusammenarbeit der Luxemburger Universität mit der Derzhavin-Universität in Tambow, Russland

Speeches/Talks (2021)

The talk was focused on the academic activities around the international and interdisciplinary seminar at the University of Luxembourg "Russia and Luxembourg at the Crossroads of History"

Sowjetische Kriegsgefangene und Ostarbeiter_innen in Luxemburg 1942-1944

in Schroeder, Frank; Hoffmann, Elisabeth; Courtoy, Jérôme (Eds.) Luxemburg und das dritte Reich (2021)

The article provides an overview of the categories of forced workers from the USSR in Luxembourg during the Second World War. In particular, in addition to specific figures, selected biographies of both ... [more ▼]

The article provides an overview of the categories of forced workers from the USSR in Luxembourg during the Second World War. In particular, in addition to specific figures, selected biographies of both Soviet prisoners of war and civilian "Eastern workers" are given. The article treats their transportation from the Nazi-occupied Soviet territories, the life in a Luxembourger camp, living conditions, supply of clothes and shoes, food, working conditions and punishments. It also provides examples of the Luxembourg population sheltering prisoners who escaped from the camp. The article ends with a statistical summary of the penalties for collaboration, which were subjected to forced workers who returned to their Soviet homeland. [less ▲]

Cybersecurity, the AI Act and the 'State of the Art'

Presentation (2021, November 12)

AGROECOLOGICS. TOWARDS A TERRITORIAL, INTEGRATIVE AGRI-URBAN DESIGN. LUXEMBOURG AS A CASE STUDY.

Doctoral thesis (2021)

This PhD thesis deals with the interrelation of the disconnected fields of urbanism, agriculture, ecology and planning. Such an attempt was inspired by a renewed relationship between the urban and ... [more ▼]

This PhD thesis deals with the interrelation of the disconnected fields of urbanism, agriculture, ecology and planning. Such an attempt was inspired by a renewed relationship between the urban and agriculture, built from the perspective of agroecology and its manifestation in urban design and planning. Despite the growing interest in agricultural production in and around cities, urban planning processes are still ignoring its integration. In most instances when undeveloped land is available, neither food production nor the quality of soil have a high priority for planners and are mostly considered at the end of a planning process. While food entered the planning agenda more than a decade ago through the emergence of urban food planning, a perspective of food planning as a discipline towards an ‘urbanism’, i.e. agroecological urbanism, is still missing. Therefore, this PhD thesis is based on the conviction that urban planning should be reassessed from an agricultural perspective. In doing so, it introduces the notion of an agri-urban design, which aims to develop land with instead of against the agricultural landscape. The context of Luxembourg has been used to remedy such a missing link and propose a highly constructive and integrative planning approach that considers agriculture and its soil quality, within the planning process. The research is structured in five different methodological approaches ranging from a historical, comparative, multi-scalar case study, land-suitability towards a prospective approach. Each approach thereby builds on the findings of each other. Such a mixed-methods approach underlines the complexity and interdisciplinary nature of the different strands of urban and agricultural development. The results are subject to different validation methods, culminating in the formulation of a prospective vision of land use planning and design for the case of Luxembourg by combining agroecological principles. [less ▲]

Applying the Presumption of Innocence to Policing with AI

in International Review of Penal Law (2021), 92(1),

This paper argues that predictive policing, which relies upon former arrest records, hinders the future application of the presumption of innocence. This is established by positing that predictive ... [more ▼]

This paper argues that predictive policing, which relies upon former arrest records, hinders the future application of the presumption of innocence. This is established by positing that predictive policing is comparable to traditional criminal investigations in substance and scope. Police records generally do not clarify whether former charges result in dismissal or acquittal, or conversely, conviction. Therefore, police as state actors may unlawfully act in reliance on an individual’s former arrest record, despite a favourable disposition. Accordingly, it is argued that the presumption of innocence as a fair trial right may be effectively nullified by predictive policing. [less ▲]

Using Automatic Item Generation in the context of the Épreuves Standardisées (Épstan): A pilot study on effects of altering item characteristics and semantic embeddings

Scientific Conference (2021, November 11)

Assessing mathematical skills in national school monitoring programs such as the Luxembourgish Épreuves Standardisées (ÉpStan) creates a constant demand of developing high-quality items that is both ... [more ▼]

Assessing mathematical skills in national school monitoring programs such as the Luxembourgish Épreuves Standardisées (ÉpStan) creates a constant demand of developing high-quality items that is both expensive and time-consuming. One approach to provide high-quality items in a more efficient way is Automatic Item Generation (AIG, Gierl, 2013). Instead of creating single items, cognitive item models form the base for an algorithmic generation of a large number of new items with supposedly identical item characteristics. The stability of item characteristics is questionable, however, when different semantic embeddings are used to present the mathematical problems (Dewolf, Van Dooren, & Verschaffel, 2017, Hoogland, et al., 2018). Given culture-specific knowledge differences in students, it is not guaranteed that illustrations showing everyday activities do not differentially impact item difficulty (Martin, et al., 2012). Moreover, the prediction of empirical item difficulties based on theoretical rationales has proved to be difficult (Leighton & Gierl, 2011). This paper presents a first attempt to better understand the impact of (a) different semantic embeddings, and (b) problem-related variations on mathematics items in grades 1 (n = 2338), 3 (n = 3835) and 5 (n = 3377) within the context of ÉpStan. In total, 30 mathematical problems were presented in up to 4 different versions, either using different but equally plausible semantic contexts or altering the problem’s content characteristics. Preliminary results of IRT-scaling and DIF-analysis reveal substantial effects of both, the embedding, as well as the problem characteristics on general item difficulties as well as on subgroup level. Further results and implications for developing mathematic items, and specifically, for using AIG in the course of Épstan will be discussed. [less ▲]

Radial analysis and scaling of urban land use

in Scientific Reports (2021), (22044),

We determine the functional form and scaling law of radial artificial land use profiles in 300 European functional urban areas (FUAs). These profiles, starting from a fully artificial surface in the city ... [more ▼]

We determine the functional form and scaling law of radial artificial land use profiles in 300 European functional urban areas (FUAs). These profiles, starting from a fully artificial surface in the city center, decrease exponentially, the faster the smaller the city. More precisely, the characteristic decrease distance scales like the square root of total population, meaning that the artificial surface of cities is proportional to their population. This also means that the amount of artificial land per capita is independent of city size, and that larger cities are not more or less parsimonious in terms of land use than smaller ones. [less ▲]

Development of a screening tool for functional vision impairments in early childhood

Scientific Conference (2021, November 11)

Cerebral Visual Impairment (CVI) is a term used to designate a neurological disorder of the visual pathways impacting visual processes at any given level (Lueck et al., 2019). Due to the advances n ... [more ▼]

Cerebral Visual Impairment (CVI) is a term used to designate a neurological disorder of the visual pathways impacting visual processes at any given level (Lueck et al., 2019). Due to the advances n perinatal and medicinal care, CVI’s occurrence has increased significantly over the last years (Chokron & Dutton, 2016). The condition almost always entails aggregated functional vision impairments, i.e., limitations on the use of binocular vision during everyday tasks (Dutton, 2015). CVI can have effects on school achievements if undetected. Early detection is thus key to offer appropriate aids to avoid a negative impact on learning processes. The aim of this project is to develop a large-scale screener at the beginning of formal schooling, to identify functional vision impairments early on. For this reason, a set of items assessing different visual functions will be incorporated into the Luxembourgish school monitoring program. Based on a theoretical model of object recognition (Humphreys and Riddoch, 1987), we developed items that can be administered in a classroom setting which target different stages of visual perceptual processing, as well as visual functions connected with both dorsal and ventral streams, visual spatial processing and visual memory. We will present the design of the large-scale screener in relation to the theoretical model, as well as the rationale used to include or exclude various perceptual visual functions in the final test. Furthermore, we will explain the foreseen data collection and tool validation processes. [less ▲]

Enhancing Photovoltaic Hosting Capacity in Distribution Grid via Grid Reconfigurations, PV Droops and Battery Inverter Control

Doctoral thesis (2021)

The EU 2030 climate and energy framework has set a mandatory goal to achieve a renewable energy share in the final energy demand of 32% by 2030. Moreover, in the final National Energy and Climate Plan ... [more ▼]

The EU 2030 climate and energy framework has set a mandatory goal to achieve a renewable energy share in the final energy demand of 32% by 2030. Moreover, in the final National Energy and Climate Plan (NECP) Luxembourg has defined its renewable generation share goal at 25% by 2030. Between 2018 and 2019, three times more photovoltaic (PV) panels were installed than in the previous years. To achieve the NECP target and to ensure further smooth integration of PV systems, the PV hosting capacity (HC) of the grid should be enhanced. This thesis discusses the common issues and current developments of HC enhancement and presents three HC enhancement techniques: grid reconfiguration and grid-code modification, extended current droop control and transformer loading control. First, the thesis analyzes the potential of grid reconfiguration in HC enhancement. For the analysis the grid configurations are divided into meshed and radial subsets. The grid reconfiguration analysis and HC calculation are done using pandapower and NetworkX library. The cross-influence and the location of DG are considered while determining the HC of the grid. The analysis shows that proper grid configuration selection is important as it can substantially increase the HC and decrease the average loading in the lines. Second, the impact of extended current droops on HC enhancement is investigated. In the designed extended current droops (Id(V ), Iq(V )), extra reactive power reserve is made available by changing the droop gain of the reactive current droop when the overvoltage is not cleared by the existing reactive power reserve. The simulations proved that the extended current droops are a viable grid reinforcement strategy which can not only regulate the voltage at the point of common coupling (PCC), but also relax the transformer loading and improve overall voltage and frequency stability. Additionally, oversizing of the inverter increases the reactive power reserve, which in turn lowers the voltage profile and decreases the amount of curtailed active power. Finally, two novel communication-less transformer overloading protection strategies based on a battery energy storage (BES): transformer protection droops (TPD) and direct loading control (DLC), are designed and compared. Both strategies force the PV inverters to curtail their active power output without relying on communication. The strategies have been tested on detailed models, where the total installed PV power varies between 0.9 to 2 times the transformer rating. The static and dynamic performance of the DLC is superior to the TPD control strategy. DLC is a robust control strategy. It can reduce the transformer loading by 41%, compared to the grid configuration without BES and bring the system to the steady-state within 700ms in the worst-case scenario. It also ensures to keep the system voltages within safe operational limits. It can be used as a backup active power curtailment solution in the cases of communication failure in centralized control. [less ▲]

Presenter: Childhood in Times of Political Transformation in the 20th Century

Presentation (2021, November 11)