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See detailDivision in modules and Kummer theory
Tronto, Sebastiano UL

E-print/Working paper (2021)

In this work we generalize the concept of injective module and develop a theory of divisibility for modules over a general ring, which provides a general and unified framework to study Kummer-like field ... [more ▼]

In this work we generalize the concept of injective module and develop a theory of divisibility for modules over a general ring, which provides a general and unified framework to study Kummer-like field extensions arising from commutative algebraic groups. With these tools we provide an effective bound for the degree of the field extensions arising from division points of elliptic curves, extending previous results of Javan Peykar for CM curves and of Lombardo and the author for the non-CM case. [less ▲]

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See detailSome uniform bounds for elliptic curves over Q
Lombardo, Davide; Tronto, Sebastiano UL

E-print/Working paper (2021)

We give explicit uniform bounds for several quantities relevant to the study of Galois representations attached to elliptic curves E/Q. We consider in particular the subgroup of scalars in the image of ... [more ▼]

We give explicit uniform bounds for several quantities relevant to the study of Galois representations attached to elliptic curves E/Q. We consider in particular the subgroup of scalars in the image of Galois, the first Galois cohomology group with values in the torsion of E, and the Kummer extensions generated by points of infinite order in E(Q). [less ▲]

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See detailNew Weak Admissibility Semantics for Abstract Argumentation
Dauphin, Jérémie UL; Rienstra, Tjitze; van der Torre, Leon UL

in International Conference on Logic and Argumentation (2021)

Baumann, Brewka and Ulbricht recently introduced weak admissibility as an alternative to Dung’s notion of admissibility, and they used it to define weakly preferred, weakly complete and weakly grounded ... [more ▼]

Baumann, Brewka and Ulbricht recently introduced weak admissibility as an alternative to Dung’s notion of admissibility, and they used it to define weakly preferred, weakly complete and weakly grounded semantics of argumentation frameworks. In earlier work, we introduced two variants of their new semantics which we called qualified and semi-qualified semantics. We analysed all known variants of weak admissibility semantics with respect to some of the principles discussed in the literature on abstract argumentation, as well as some new principles we introduced to distinguish them all. Such a principle-based analysis can be used not only for selecting a semantics for an application, or for algorithmic design, but also for further research into weak admissibility semantics. In this paper, we introduce six new kinds of semantics based on weak admissibility, and we provide an initial principle-based analysis. The analysis illustrates various ways in which the new semantics improve on existing ones. [less ▲]

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See detailConstitutional engineering of State of exception regimes within the European Union
Gerkrath, Jörg UL

E-print/Working paper (2021)

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See detailAnonymization between minimization and erasure: The perspectives of French and Italian data protection authorities
Podda, Emanuela UL; Vigna, Francesco UL

in Electronic Government and the Information Systems Perspective: 10th International Conference, EGOVIS 2021 Virtual Event, September 27–30, 2021 Proceedings (2021)

Two years after the General Data Protection Regulation (GDPR) went into effect, data anonymization remains one of the main issues linked to fragmen-tation in the Member States’ anonymization policies, in ... [more ▼]

Two years after the General Data Protection Regulation (GDPR) went into effect, data anonymization remains one of the main issues linked to fragmen-tation in the Member States’ anonymization policies, in which regard stakehold-ers would like additional guidelines. In keeping with this premise, this article aims to analyze and compare trends in the implementation and enforcement of anonymization policies put in place by data protection authorities in two countries: France and Italy. This analysis makes it possible to trace the evolution of these policies and high-light their critical importance in applying the data minimization principle and in enforcing the right to erasure under Art. 17 GDPR. [less ▲]

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See detailDemand-Based Adaptive Multi-Beam Pattern and Footprint Planning for High Throughput GEO Satellite Systems
Jubba Honnaiah, Puneeth UL; Maturo, Nicola; Chatzinotas, Symeon UL et al

in IEEE Open Journal of the Communications Society (2021)

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See detailScalable Cell-Free Massive MIMO Systems: Impact of Hardware Impairments
Papazafeiropoulos, Anastasios; Björnson, Emil; Kourtessis, Pandelis et al

in IEEE Transactions on Vehicular Technology (2021), 70(10), 9701-9715

Scalable cell-free CF (SCF) massive multiple-input-multiple-output (mMIMO) systems is a promising technology to cover the demands for higher data rates and increasing number of users in fifth generation ... [more ▼]

Scalable cell-free CF (SCF) massive multiple-input-multiple-output (mMIMO) systems is a promising technology to cover the demands for higher data rates and increasing number of users in fifth generation (5G) networks and beyond. According to this concept, a large number of distributed access points (APs) communicates with the users in the network by means of joint coherent transmission while facing the main challenges against standard CF mMIMO systems being their high fronthaul load and computational complexity. Given that the cost-efficient deployment of such large networks requires low-cost transceivers being prone to unavoidable hardware imperfections, in this work, we focus on their impact on the advantageous SCF mMIMO systems by means of a general model accounting for both additive and multiplicative hardware impairments (HWIs). Notably, the scalability, depending on the time-variant characteristics of the network, is clearly affected by means of HWIs being time-varying. There is no other work in the literature studying the phase noise (PN) in CF mMIMO systems or in general any HWIs in SCF mMIMO systems. Hence, we derive upper and lower bounds on the uplink capacity accounting for HWIs. Especially, the lower bound is derived in closed-form by means of the theory of deterministic equivalents (DEs) and after obtaining the optimal hardware-aware (HA) partial minimum mean-squared error (PMMSE) combiner. Among the interesting findings, we observe that separate local oscillators (SLOs) outperform a common LO (CLO) architecture, and the additive transmit distortion degrades more the performance than the receive distortion. [less ▲]

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See detailVortical flow structures induced by red blood cells in capillaries.
Yaya, François; Römer, Johannes; Guckenberger, Achim et al

in Microcirculation (New York, N.Y. : 1994) (2021), 28(5), 12693

OBJECTIVE: Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles ... [more ▼]

OBJECTIVE: Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles and molecules in the flowing plasma. We conducted an experimental study on the flow field around red blood cells in capillary flow that is complemented by simulations of vortical flow between red blood cells. METHODS: Red blood cells were injected in a 10 × 12 µm rectangular microchannel at a low hematocrit, and the flow field around one or two cells was captured by a high-speed camera that tracked 250 nm nanoparticles in the flow field, acting as tracers. RESULTS: While the flow field around a steady "croissant" shape is found to be similar to that of a rigid sphere, the flow field around a "slipper" shape exhibits a small vortex at the rear of the red blood cell. Even more pronounced are vortex-like structures observed in the central region between two neighboring croissants. CONCLUSIONS: The rotation frequency of the vortices is to a good approximation, inversely proportional to the distance between the cells. Our experimental data are complemented by numerical simulations. [less ▲]

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See detailHeartbeat evoked potentials in patients with posttraumatic stress disorder: an unaltered neurobiological regulation system?
Schmitz, Marius; Müller, Laura E.; Seitz, Katja I. et al

in European Journal of Psychotraumatology (2021), 12(1), 1987686

Background: Early life maltreatment is a risk factor for psychiatric disorders, including posttraumatic stress disorder (PTSD). Posttraumatic stress disorder is a severe and heterogeneous disorder with ... [more ▼]

Background: Early life maltreatment is a risk factor for psychiatric disorders, including posttraumatic stress disorder (PTSD). Posttraumatic stress disorder is a severe and heterogeneous disorder with fluctuating states of emotional over- and undermodulation including hypervigilance, dissociation, and emotion regulation deficits. The perception and regulation of emotions have been linked to interoception, the cortical representation and sensing of inner bodily processes. Although first therapeutic approaches targeting bodily sensations have been found effective in patients with PTSD, and deficits in interoceptive signal representation have been reported in other trauma-related disorders such as borderline personality disorder (BPD), the role of interoception remains largely unexplored for PTSD. Objective: The objective was to investigate the cortical representation of cardiac interoceptive signals in patients with PTSD and its associations with early life maltreatment, trait dissociation, and emotion dysregulation. Methods: Twenty-four medication-free patients with PTSD and 31 healthy controls (HC) completed a 5-min resting electrocardiogram (ECG) with parallel electroencephalogram (EEG). Heartbeat evoked potential (HEP) amplitudes as a measure for cortical representation of cardiac interoceptive signals were compared between groups and correlated with self-report questionnaires. Results: We did not find significantly different mean HEP amplitudes in patients with PTSD compared to HC, although HEPs of patients with PTSD were descriptively higher. No significant associations between mean HEP amplitudes and early life maltreatment, trait dissociation or emotion dysregulation were obtained within the groups. Conclusion: The current finding does not indicate deficits in interoceptive signal representation at rest in individuals with PTSD. Whether patients with PTSD show altered HEP modulations during emotion regulation tasks and might benefit from therapeutic approaches aiming at changing the perception of bodily signals, needs to be investigated in future studies. [less ▲]

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See detailLe Congrès de Vienne et le statut international du Grand-Duché de Luxembourg : théories et réalités du droit des gens de l’Europe
Erpelding, Michel UL

in Actes de la section des sciences morales et politiques de l'Institut grand-ducal (2021), 24

This articles examines the international status of Luxembourg between 1815 and 1867 from the perspective of the international law applicable at that time and based on the relevant state practice. It ... [more ▼]

This articles examines the international status of Luxembourg between 1815 and 1867 from the perspective of the international law applicable at that time and based on the relevant state practice. It contends that - from the perspective of international law - Luxembourg emerged as a state after the evacuation of Belgian troops from its territory in 1839. [less ▲]

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See detail“Crowning of the democratic edifice”? — Public discourses on referendums in Luxembourg since the First World War
Wagener, Renée UL

in Topos. Journal for philosophy and cultural studies (2021), (1), 3254

The contribution gives an oversight over the four series of referenda that have taken place in Luxembourg since the introduction of universal suffrage in 1919. For each date, the historical background ... [more ▼]

The contribution gives an oversight over the four series of referenda that have taken place in Luxembourg since the introduction of universal suffrage in 1919. For each date, the historical background, the main actors, the controverse positions as well as the impact on Luxembourgish society are explored. Thereby, the article shows the political processes linked to the organisation of referenda. At the same time, it presents the evolution of the discourses in Luxembourg on referenda as an expression of political conflicts as well as more generally on referendum as a political instrument. Referenda seem to have been used on one hand in situations where parliament could not play its role or was suspected not to be willing to do so, on the other hand to clarify questions that seemed so important that the voters had to be asked directly for their opinion. Whereas the current conclusion that referendum campaigns contribute to show or even to deepen societal polarisations is true also for the grand-duchy, one of the more notable findings of the Luxembourgish case is that this has not retained, at least in the last decades, the utilisation of the instrument of referendum. Especially concerning matters linked to the subject of democratic or state structures, the government seems to have preferred to let the voters give their point of view, although the risk of polarisation was given and new anti-government movements often grew from the referendum campaigns. In contrast to the relative success of the referendum in the last hundred years, other instruments of direct political participation have been sparsely developed. [less ▲]

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See detailOptimal Randomized Partial Checking for Decryption Mix Nets
Haines, Thomas; Mueller, Johannes UL

in Information Security and Privacy - 26th Australasian Conference, ACISP 2021, Virtual Event, December 1-3, 2021, Proceedings (2021)

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See detailWhere were the repair ingredients for Defects4j bugs?
Yang, Deheng; Liu, Kui; Kim, Dongsun et al

in Empirical Software Engineering (2021), 26(6), 1--33

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See detailUsing Blockchain to Coordinate Federal Processes: The Case of Germany's Federal Office for Migration and Refugees
Amend, Julia; van Dun, Christopher; Fridgen, Gilbert UL et al

in Urbach, Nils; Röglinger, Maximilian; Kautz, Karlheinz (Eds.) et al Digitalization Cases Vol. 2: Mastering Digital Transformation for Global Business (2021)

(a)Situation faced: The German asylum procedure requires close cooperation and information exchange between various authorities at the municipal, state, and federal levels. Federal separation of ... [more ▼]

(a)Situation faced: The German asylum procedure requires close cooperation and information exchange between various authorities at the municipal, state, and federal levels. Federal separation of competencies inhibits the delegation of process governance to a central authority such as the Federal Office for Migration and Refugees (BAMF). This separation also leads to regional differences as federal laws govern the procedure's general steps, whereas state laws govern implementation. Moreover, existing solutions for cross-organizational collaboration are limited in terms of flexibility, security, and data quality. As a result, the exchange of certain data on asylum procedures still occurs using Excel spreadsheets and e-mails.(b)Action taken: Against this backdrop, the BAMF explored technological options that would support the decentralized governance of the asylum procedure. After a preliminary evaluation, the BAMF decided to explore a solution based on blockchain technology. Building upon a successful proof of concept, the BAMF initiated a pilot project with Saxony's central immigration authority. This project aims to develop a blockchain solution that supports the coordination of asylum procedures and can be easily adapted to local differences and functional requirements.(c)Results achieved: The use of the blockchain solution allows for efficient, secure, and timely distribution of status information. It supports communication and improves coordination between authorities. Despite an apparent conflict between blockchain principles and data privacy requirements, the BAMF's design complies with relevant regulation (notably the GDPR). As a first-of-its-kind project, it outlines best practices and provides valuable insights into opportunities and challenges arising from the use of blockchain in the public sector.(d)Lessons learned: The BAMF's case demonstrates that blockchain solutions can be promising alternatives when the delegation of process governance to a central party is not desirable and when federal principles of organization are to be reflected technologically. However, blockchain projects require special attention to managing know-how and capabilities, software development activities, stakeholders, the regulatory context, and cross-organizational governance. [less ▲]

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See detailThe Proposal for a Directive on Adequate Minimum Wages in the EU
Ratti, Luca UL

in EU Law Live - Weekend Edition (2021)

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See detailIn-Work poverty in the EU - EU Law Live Special Issue (I)
Ratti, Luca UL; Garcia Munoz Alhambra, Manuel Antonio UL

in EU Law Live - Weekend Edition (2021)

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See detailContrast adaptation in face perception revealed through EEG and behavior
Gwinn, O. Scott; Retter, Talia UL; O'Neil, S. F. et al

in Frontiers in Systems Neuroscience (2021)

Exposure to a face can produce biases in the perception of subsequent faces. Typically, these face aftereffects are studied by adapting to an individual face or category (e.g., faces of a given gender ... [more ▼]

Exposure to a face can produce biases in the perception of subsequent faces. Typically, these face aftereffects are studied by adapting to an individual face or category (e.g., faces of a given gender) and can result in renormalization of perceptions such that the adapting face appears more neutral. These shifts are analogous to chromatic adaptation, where a renormalization for the average adapting color occurs. However, in color vision, adaptation can also adjust to the variance or range of colors in the distribution. We examined whether this variance or contrast adaptation also occurs for faces, using an objective EEG measure to assess response changes following adaptation. An average female face was contracted or expanded along the horizontal or vertical axis to form four images. Observers viewed a 20 s sequence of the four images presented in a fixed order at a rate of 6 Hz, while responses to the faces were recorded with EEG. A 6 Hz signal was observed over right occipito-temporal channels, indicating symmetric responses to the four images. This test sequence was repeated after 20 s adaptation to alternations between two of the faces (e.g., horizontal contracted and expanded). This adaptation resulted in an additional signal at 3 Hz, consistent with asymmetric responses to adapted and non-adapted test faces. Adapting pairs have the same mean (undistorted) as the test sequence and thus should not bias responses driven only by the mean. Instead, the results are consistent with selective adaptation to the distortion axis. A 3 Hz signal was also observed after adapting to face pairs selected to induce a mean bias (e.g., expanded vertical and expanded horizontal), and this signal was not significantly different from that observed following adaption to a single image that did not form part of the test sequence (e.g., a single image expanded both vertically and horizontally). In a further experiment, we found that this variance adaptation can also be observed behaviorally. Our results suggest that adaptation calibrates face perception not only for the average characteristics of the faces we experience but also for the gamut of faces to which we are exposed. [less ▲]

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See detailA Novel Proof of Shuffle: Exponentially Secure Cut-and-Choose
Haines, Thomas; Mueller, Johannes UL

in Information Security and Privacy - 26th Australasian Conference, ACISP 2021, Virtual Event, December 1-3, 2021, Proceedings (2021)

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See detailRare Anemias: Are Their Names Just Smoke and Mirrors?
Simionato, Greta; van Wijk, Richard; Quint, Stephan et al

in Frontiers in physiology (2021), 12

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