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See detailLa réintroduction de contrôles aux frontières intérieures de l’UE pour lutter contre la pandémie : un moyen disproportionné, inefficace et illégal
Gerkrath, Jörg UL

in Actes de l'Institut Grand-Ducal, Section sciences morales et politiques (2021)

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See detailThe DLPS: A New Framework for Benchmarking Blockchains
Sedlmeir, Johannes; Ross, Philipp; Luckow, André et al

in Proceedings of the 54th Hawaii International Conference on System Sciences (2021)

Distributed Ledger Technologies (DLT) promise to revolutionize business ecosystems by permitting secure transactions without intermediaries. A widely recognized challenge that inhibits the uptake of DLT ... [more ▼]

Distributed Ledger Technologies (DLT) promise to revolutionize business ecosystems by permitting secure transactions without intermediaries. A widely recognized challenge that inhibits the uptake of DLT is scalability and performance. Hence, quantifying key metrics such as throughput and latency is crucial for designing DLT-based infrastructures, applications, and ecosystems. However, current benchmarking frameworks for blockchains do not cover the whole benchmarking process; impeding transparent comparisons of different DLT networks. In this paper, we present the Distributed Ledger Performance Scan (DLPS), an open-source framework for end-to-end performance characterizations of blockchains, addressing the need to transparently and automatically evaluate the performance of highly customizable configurations. We describe our new framework and argue that it significantly improves existing DLT benchmarking solutions. To demonstrate the capabilities of the DLPS, we also summarize the main results obtained from a series of experiments that we have conducted with it, giving a first comprehensive comparison of essential scalability properties of several commonly used enterprise blockchains. [less ▲]

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See detailA Remote Carrier Synchronization Technique for Coherent Distributed Remote Sensing Systems
Merlano Duncan, Juan Carlos UL; Martinez Marrero, Liz UL; Querol, Jorge UL et al

in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (2020)

Phase, frequency, and time synchronization are crucial requirements for many applications, such as multi-static remote sensing and communication systems. Moreover, the synchronization solution becomes ... [more ▼]

Phase, frequency, and time synchronization are crucial requirements for many applications, such as multi-static remote sensing and communication systems. Moreover, the synchronization solution becomes even more challenging when the nodes are orbiting or flying on airborne or spaceborne platforms. This paper compares the available technologies used for the synchronization and coordination of nodes in distributed remote sensing applications. Additionally, this paper proposes a general system model and identifies preliminary guidelines and critical elements for implementing the synchronization mechanisms exploiting the inter-satellite communication link. The distributed phase synchronization loop introduced in this work deals with the self-interference in a full-duplex point to point scenario by transmitting two carriers at each node. All carriers appear with different frequency offsets around a central frequency, called the application central-frequency or the beamforming frequency. This work includes a detailed analysis of the proposed algorithm and the required simulations to verify its performance for different phase noise, AWGN, and Doppler shift scenarios. [less ▲]

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See detailUnlawful Content Online: Towards A New Regulatory Framework For Online Platforms
Ullrich, Carsten UL

Doctoral thesis (2020)

The thesis reviews the online intermediary liability framework of the E-Commerce Directive (in Articles 12 - 15) along two research questions. 1) Is the current legal framework regulating content ... [more ▼]

The thesis reviews the online intermediary liability framework of the E-Commerce Directive (in Articles 12 - 15) along two research questions. 1) Is the current legal framework regulating content liability of online platforms under the ECD still adequate when it comes to combating illegal content? 2) Are there alternative models for intermediary regulation that are better suited to include internet intermediaries in the fight against illegal content? These questions were formulated against the premises that unlawful content online has been a persisting and growing problem and that the position of online intermediaries today makes enhanced responsibilities on their part necessary. The thesis undertakes to analyse the nature of the enforcement challenges in the EU when trying to engage online platforms under the current liability framework, and charts out an alternative approach to holding online platforms responsible. Chapter 3 reviews the current intermediary framework in the EU and the horizontal challenges of holding internet intermediaries liable. This is analysed against the backdrop of the proliferation of the internet and online platforms, sketched out in the preceding Chapter 2. Due to the ambiguity and outdatedness of the ECD provisions, on the one hand, and different national secondary liability traditions, on the other hand, the liability protections of online platforms have been interpreted and applied differently by EU Member States, and most importantly courts, leading to an uneven and ineffective enforcement landscape. Chapter 4 analyses sectoral provisions that cover different kinds of offences related to unlawful content and their interactions with the ECD and national legislation on intermediary liability. The thesis evaluates enforcement efforts in the areas of defamation, hate speech, terrorist content, copyright, trademarks, product safety and food safety. While none of the national (sectoral) approaches reviewed appear to be effective when trying to enlist intermediaries in the fight against unlawful content, the latter have built up powerful own private enforcement systems that have come to rival and run counter to public interests and fundamental rights. Chapter 5 introduces case studies of online enforcement in the areas of product and food safety, based on interviews conducted with market surveillance authorities in the EU. The specific enforcement system of EU product regulation poses particular challenges, but also offers some useful lessons for the eventual framework proposed in Chapter 6. This system eschews today’s liability cornerstones and the reliance of self-regulatory tools favoured by EU and national legislators so far. Instead it proposes an enhanced responsibility system, based on harmonised technical standards as used in the EU's New Approach regulatory method. Technical standards would define duty of care obligations in the guise of risk management approaches, which focus on defined (sectoral) harms that arise from the business practices of online platforms. They incorporate prospective responsibilities, such as for example safety by design for user onboarding, user empowerment, or (algorithmic) content management, as well as specific retrospective responsibilities relating to e.g. notice and takedown or content identification system. The standard can be adapted to the type of harm/violation, thus taking account of the specific fundamental rights and public interests involved on a sectoral level. [less ▲]

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See detailAsynchronous Stream Data Processing using a Light-Weight and High-Performance Dataflow Engine
Ellampallil Venugopal, Vinu UL; Theobald, Martin UL

Presentation (2020, December 11)

Processing high-throughput data-streams has become a major challenge in areas such as real-time event monitoring, complex dataflow processing, and big data analytics. While there has been tremendous ... [more ▼]

Processing high-throughput data-streams has become a major challenge in areas such as real-time event monitoring, complex dataflow processing, and big data analytics. While there has been tremendous progress in distributed stream processing systems in the past few years, the high-throughput and low-latency (a.k.a. high sustainable-throughput) requirement of modern applications is pushing the limits of traditional data processing infrastructures. This paper introduces a new distributed stream data processing engine (DSPE), called “Asynchronous Iterative Routing” or simply AIR, which implements a light-weight, dynamic sharding protocol. AIR expedites a direct and asynchronous communication among all the worker nodes via multiple Message Passing Interface (MPI) communication channels and thereby completely avoids any additional communication overhead with a dedicated master node. With its unique design, AIR scales out to clusters consisting of up to 8 nodes and 224 cores, performing much better than existing DSPEs, and it performs up to 15 times better than Spark and Flink in terms of sustainable-throughput. [less ▲]

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See detailFormation of ultra-thin Ge1−xSnx/Ge1−x−ySixSny quantum heterostructures and their electrical properties for realizing resonant tunneling diode
Suwito, Galih Ramadana; Fukuda, Masahiro; Suprayoga, Edi et al

in Applied Physics Letters (2020), 117(23), 232104

Huge thermal noise owing to the narrow energy bandgap is one of the critical issues for group IV-based photonics in the mid-infrared regime. With this motivation, we examined to form Ge1−xSnx ... [more ▼]

Huge thermal noise owing to the narrow energy bandgap is one of the critical issues for group IV-based photonics in the mid-infrared regime. With this motivation, we examined to form Ge1−xSnx/Ge1−x−ySixSny quantum heterostructures (QHs) by molecular beam epitaxy for realizing resonant tunneling diodes composed of group-IV materials. We confirmed the formation of approximately 2 nm-thick Ge1−xSnx/Ge1−x−ySixSny QHs with atomically flat interfaces by x-ray diffraction and transmission electron microscopy methods. Moreover, by the current density–voltage (J–V) measurement at 10 K, we observed the occurrence of a non-linear distinct hump in the J–V characteristic, which is possibly originated from quantum transport of heavy holes. According to the tunneling transmission spectra simulation result, the hump property would be due to two possible scenarios: a resonant tunneling of heavy holes in the QH and/or a resonance phenomenon that heavy holes pass just above a potential barrier. [less ▲]

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See detailStochastic-Geometry-Based Interference Modeling in Automotive Radars Using Matérn Hard-Core Process
Mishra, K. V.; R., B. Shankar M.; Ottersten, Björn UL

in 2020 IEEE Radar Conference (RadarConf20), Stochastic-Geometry-Based Interference Modeling in Automotive Radars Using Matérn Hard-Core Process (2020, December 04)

As the use of radars in autonomous driving systems becomes more prevalent, these systems are increasingly susceptible to mutual interference. In this paper, we employ stochastic geometry to model the ... [more ▼]

As the use of radars in autonomous driving systems becomes more prevalent, these systems are increasingly susceptible to mutual interference. In this paper, we employ stochastic geometry to model the automotive radar interference in realistic traffic scenarios and then derive trade-offs between the radar design parameters and detection probability. Prior works model the locations of radars in the lane as a homogeneous Poisson point process (PPP). However, the PPP models assume all nodes to be independent, do not account for the lengths of vehicles, and ignore spatial mutual exclusion. In order to provide a more realistic interference effect, we adopt the Matérn hardcore process (MHCP) instead of PPP, in which two vehicles are not closer than an exclusion radius from one another. We show that the MHCP model leads to more practical design trade-offs for adapting the radar parameters than the conventional PPP model. [less ▲]

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See detailIntroduction : les Cahiers de la Grande Région - Quelles équations à résoudre pour le marché du travail transfrontalier (n°2) et la formation dans la Grande Région Réalités et défis (n°3)
Pigeron-Piroth, Isabelle UL

Conference given outside the academic context (2020)

A l’occasion de la publication de la troisième édition de la série Cahiers de la Grande Région, la Fondation IDEA asbl et le réseau Center for Border Studies de l’Université de la Grande Région (UniGR-CBS ... [more ▼]

A l’occasion de la publication de la troisième édition de la série Cahiers de la Grande Région, la Fondation IDEA asbl et le réseau Center for Border Studies de l’Université de la Grande Région (UniGR-CBS), en partenariat avec les membres de l’initiative des Cahiers de la Grande Région ont le plaisir de vous inviter à participer à la prochaine conférence-débat qui portera sur le thème: Inadéquations, compétences, formation… Quelles équations pour le marché du travail transfrontalier ? Eléments de réflexion à partir des Cahiers de la Grande Région #2 et #3 [less ▲]

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See detailLogiKEy Workbench: Deontic Logics, Logic Combinations and Expressive Ethical and Legal Reasoning (Isabelle/HOL Dataset)
Benzmüller, Christoph UL; Farjami, Ali UL; Fuenmajor, David et al

in Data in Brief (2020), 33

The LogiKEy workbench and dataset for ethical and legal reasoning is presented. This workbench simultaneously supports development, experimentation, assessment and deployment of formal logics and ethical ... [more ▼]

The LogiKEy workbench and dataset for ethical and legal reasoning is presented. This workbench simultaneously supports development, experimentation, assessment and deployment of formal logics and ethical and legal theories at different conceptual layers. More concretely, it comprises, in form of a dataset (Isabelle/HOL theory files), formal encodings of multiple deontic logics, logic combinations, deontic paradoxes and normative theories in the higher-order proof assistant system Isabelle/HOL. The data were acquired through application of the LogiKEy methodology, which supports experimentation with different normative theories, in different application scenarios, and which is not tied to specific logics or logic combinations. Our workbench consolidates related research contributions of the authors and it may serve as a starting point for further studies and experiments in flexible and expressive ethical and legal reasoning. It may also support hands-on teaching of non-trivial logic formalisms in lecture courses and tutorials. [less ▲]

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See detailConstant Envelope MIMO-OFDM Precoding for Low Complexity Large-Scale Antenna Array Systems
Domouchtsidis, Stavros UL; Tsinos, Christos UL; Chatzinotas, Symeon UL et al

in IEEE Transactions on Wireless Communications (2020)

Herein, we consider constant envelope precoding in a multiple-input multiple-output orthogonal frequency division multiplexing system (CE MIMO-OFDM) for frequency selective channels. In CE precoding the ... [more ▼]

Herein, we consider constant envelope precoding in a multiple-input multiple-output orthogonal frequency division multiplexing system (CE MIMO-OFDM) for frequency selective channels. In CE precoding the signals for each transmit antenna are designed to have constant amplitude regardless of the channel realization and the information symbols that must be conveyed to the users. This facilitates the use of power-efficient components, such as phase shifters (PS) and nonlinear power amplifiers, which are key for the feasibility of large-scale antenna array systems because of their low cost and power consumption. The CE precoding problem is firstly formulated as a least-squares problem with a unit modulus constraint and solved using an algorithm based on coordinate descent. The large number of optimization variables in the case of the MIMO-OFDM system motivates the search for a more computationally efficient solution. To tackle this, we reformulate the CE precoding design into an unconstrained nonlinear least-squares problem, which is solved efficiently using the Gauss-Newton algorithm. Simulation results underline the efficiency of the proposed solutions and show that they outperform state of the art techniques. [less ▲]

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See detailUn inventaire du patrimoine après une épidémie de démolitions?
Pauly, Michel UL

Article for general public (2020)

plaidoyer pour l'introduction d'une procédure d'urgence dans le projet de loi 7473 afin d'éviter des démolitions en masse avant la finalisation de l'inventaire des monuments historiques

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See detailAge, Intentions and the Implicit Role of Out-Selection Factors of International Migration
Beine, Michel UL

E-print/Working paper (2020)

In this paper, I propose to isolate the role of age as a self-selection factor of international migration. The role of age is estimated on intended emigration rather than on observed outcomes of migration ... [more ▼]

In this paper, I propose to isolate the role of age as a self-selection factor of international migration. The role of age is estimated on intended emigration rather than on observed outcomes of migration, using individual measures of intended emigration drawn from a large-scale survey conducted by Gallup. I find evidence that age has a monotonic negative effect on desired emigration for the working-age population. The estimations point to a very robust effect, suggesting that an additional year of age decreases the probability of intended emigration by about 0.5%. This effect is steady over different periods of time and for most types of countries of origin. The results contrast with previous evidence obtained on observed outcomes of migration, suggesting that out-selection factors interact with age and shape the demographic profile of migrants. [less ▲]

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See detailManaging residence permits and unemployment of third-country nationals during the COVID-19 crisis in the EU
Sommarribas, Adolfo UL

in Journaal Vreemdelingenrecht (2020), 19(4), 14-21

This article will try to provide a state of play of the response of the EU Member States to the COVID-19 crisis in regard to third-country nationals through the information compiled by the European ... [more ▼]

This article will try to provide a state of play of the response of the EU Member States to the COVID-19 crisis in regard to third-country nationals through the information compiled by the European Migration Network between 3 February until 15 June 2020. It will draw a state of play of the actions taken by Member States to confront the spread of the coronavirus in the immigration context. It also will focus on the validity of residence permits and the dispositions taken to avoid that legal migrants fall in an irregular situation and the effects of unemployment in regard to their residence permits. However, the article will not draw a timeline on when the actions were taken. [less ▲]

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See detailLow-light image enhancement of permanently shadowed lunar regions with physics-based machine learning
Moseley, Ben; Bikel, Valentin; Lopez-Francos, Ignacio et al

in Low-light image enhancement of permanently shadowed lunar regions with physics-based machine learning (2020, December)

Finding water(-ice) on the Moon is key to enabling a sustainable human presence on the Moon and beyond. There is evidence that water-ice is abundant in and around the Moon’s Permanently Shadowed Regions ... [more ▼]

Finding water(-ice) on the Moon is key to enabling a sustainable human presence on the Moon and beyond. There is evidence that water-ice is abundant in and around the Moon’s Permanently Shadowed Regions (PSRs), however, direct visual detection has not yet been possible. Surface ice or related physical features could potentially be directly detected from high-resolution optical imagery, but, due to the extremely low-light conditions in these areas, high levels of sensor and photon noise make this very challenging. In this work we generate high-resolution, low-noise optical images over lunar PSRs by using two physics-based deep neural networks to model and remove CCD-related and photon noise in existing low-light optical imagery, potentially paving the way for a direct water-ice detection method. [less ▲]

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See detailState Aggregation for Multiagent Communication over Rate-Limited Channels
Mostaani, Arsham UL; Vu, Thang Xuan UL; Chatzinotas, Symeon UL et al

in IEEE Global Communications Conference (2020)

A collaborative task is assigned to a multiagent system (MAS) in which agents are allowed to communicate. The MAS runs over an underlying Markov decision process and its task is to maximize the averaged ... [more ▼]

A collaborative task is assigned to a multiagent system (MAS) in which agents are allowed to communicate. The MAS runs over an underlying Markov decision process and its task is to maximize the averaged sum of discounted one-stage rewards. Although knowing the global state of the environment is necessary for the optimal action selection of the MAS, agents are limited to individual observations. The inter-agent communication can tackle the issue of local observability, however, the limited rate of the inter-agent communication prevents the agent from acquiring the precise global state information. To overcome this challenge, agents need to communicate their observations in a compact way such that the MAS compromises the minimum possible sum of rewards. We show that this problem is equivalent to a form of rate-distortion problem which we call the task-based information compression. State Aggregation for Information Compression (SAIC) is introduced here to perform the task-based information compression. The SAIC is shown, conditionally, to be capable of achieving the optimal performance in terms of the attained sum of discounted rewards. The proposed algorithm is applied to a rendezvous problem and its performance is compared with two benchmarks; (i) conventional source coding algorithms and the (ii) centralized multiagent control using reinforcement learning. Numerical experiments confirm the superiority and fast convergence of the proposed SAIC. [less ▲]

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See detailÉcologie, culture, Grande Région : remarques introductives sur une relation plurielle et complexe
Thiltges, Sébastian UL; Solte-Gresser, Christiane

in Thiltges, Sébastian; Solte-Gresser, Christiane (Eds.) Écologie culturelle et cultures écologiques dans la Grande Région (2020, December)

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