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See detail550 GHz bandwidth photodetector on low-temperature grown molecular-beam epitaxial GaAs
Kordoš, P.; Förster, A.; Marso, Michel UL et al

in Electronics Letters (1998), 34(1998), 119-120

The authors demonstrate that a 550GHz bandwidth photodetector can be fabricated on low-temperature grown MBE GaAs. The pulse response shows 0.4 and 0.6ps rise and fall times, respectively. The bandwidth ... [more ▼]

The authors demonstrate that a 550GHz bandwidth photodetector can be fabricated on low-temperature grown MBE GaAs. The pulse response shows 0.4 and 0.6ps rise and fall times, respectively. The bandwidth is in agreement with a value calculated using a carrier lifetime of 0.2ps, measured by femtosecond time-resolved reflectivity, and a capacitance of 0.014fF/um2, determined from microwave measurements. The device bandwidth is RC limited. [less ▲]

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See detail56. Aktualisierungslieferung - §§ 14, 43, 52b, 62, 64 RStV
Cole, Mark UL; Hartstein; Ring et al

Book published by Jehle-Rehm (2013)

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See detail§§ 58 bis 62 WpHG betreffend Datenbereitstellungsdienste
Zetzsche, Dirk Andreas UL; Lehmann, M.

in Kapitalmarktrechtskommentar (2020)

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See detail5D Super Yang-Mills on Y p,q Sasaki-Einstein manifolds
Qiu, Jian UL; Zabzine, Maxim

E-print/Working paper (2013)

On any simply connected Sasaki-Einstein five dimensional manifold one can construct a super Yang-Mills theory which preserves at least two supersymmetries. We study the special case of toric Sasaki ... [more ▼]

On any simply connected Sasaki-Einstein five dimensional manifold one can construct a super Yang-Mills theory which preserves at least two supersymmetries. We study the special case of toric Sasaki-Einstein manifolds known as Y p,q manifolds. We use the localisation technique to compute the full perturbative part of the partition function. The full equivariant result is expressed in terms of certain special function which appears to be a curious generalisation of the triple sine function. As an application of our general result we study the large N behaviour for the case of single hypermultiplet in adjoint representation and we derive the N 3-behaviour in this case. [less ▲]

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See detail5D super Yang-Mills on Yp,q Sasaki-Einstein manifolds
Qiu, Jian UL; Zabzine, Maxim

in Communications in Mathematical Physics (2015), 333(2),

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See detail5G AND BEYOND NETWORKS WITH UAV: TRAJECTORY DESIGN AND RESOURCE ALLOCATION
Tran Dinh, Hieu UL

Doctoral thesis (2021)

Over the past few years, unmanned aerial vehicle (UAV)-enabled wireless communications have attracted considerable attention from both academia and industry due to their high mobility, low cost, strong ... [more ▼]

Over the past few years, unmanned aerial vehicle (UAV)-enabled wireless communications have attracted considerable attention from both academia and industry due to their high mobility, low cost, strong light-of-sight communication links, and ease of deployment. Specifically, UAVs can be deployed to serve as aerial base stations (BSs), relays, power sources, etc., to support ground users (GUs) in various scenarios such as surveillance missions, search and rescue, crop monitoring, delivery of goods, data collection, emergency communications, secrecy communications, space-air-ground communications, etc. Despite many advantages, UAV-enabled communications are not without limitations. The limitations of UAVs have imposed technical restrictions on weight, size, and energy capability, thereby affecting the durability and performance of UAVs. The key goal of this dissertation is to propose and develop new frameworks and efficient optimization algorithms to solve novel challenging problems, facilitate the design and deployment of UAV-enabled communications. Consequently, these proposed algorithms can become one of the foundations for deploying UAVs in future wireless systems. Specifically, this dissertation investigates different UAV communication systems by addressing several important research problems through four emerging scenarios: 1) Design UAV trajectory based on traveling salesman problem with time window (TSPTW); 2) Full-duplex (FD) UAV relay-assisted emergency communications in Internet of Things (IoT) networks; 3) Backscatter- and cache-assisted UAV communications; and 4) Satellite- and cache-assisted UAV communications in 6G aerial networks. In the first scenario, we provide the coarse trajectory for the UAV based on TSPTW, which has not been investigated in UAV communications yet. Concretely, we propose two trajectory design algorithms based on TSPTW, namely heuristic algorithm and dynamic programming (DP)-based algorithm, and they are compared with exhaustive search and traveling salesman problem (TSP)-based methods. Based on the feasible path obtained from proposed algorithms, we minimize the total UAV’s energy consumption for each given path via a joint optimization of the UAV velocities in all hops. Simulation results show that the energy consumption value of DP is very close to that of the exhaustive algorithm with greatly reduced complexity. Based on this work, an efficient TSPTW-based algorithm can be used as an initialized trajectory for designing a joint problem of UAV trajectory and other communications factors (e.g., communication scheduling, transmit power allocation, time allocation), which are challenges. We then study the case of a FD UAV relaying system in IoT networks. Specifically, a UAV can be deployed as a flying base station (BS) to collect data from time-constrained IoT devices and then transfer it to a ground gateway (GW). Especially, the impact of latency constraint for the uplink (UL) and downlink (DL) transmission utilizing FD or half-duplex (HD) mode is investigated. Using the proposed system model, we aim to maximize the total number of served IoT devices subject to the maximum speed constraint of the UAV, total traveling time constant, UAV trajectory, maximum transmit power at the devices/UAV, limited cache size of the UAV, and latency constraints for both UL and DL. Next, we attempt to maximize the total throughput subject to the number of served IoT devices. The outcome of this work will motivate a new framework for UAV-aided communications in disaster or emergency communications. Next, a novel system model that considers SWIPT, backscatter and caching in UAV wireless networks is developed. Based on this model, we aim to maximize the system throughput by jointly optimizing the dynamic time splitting (DTS) ratio and the UAV’s trajectory with caching capability at the UAV. This is the first work that jointly considers wireless power transfer (WPT), caching, and BackCom in UAV communications, which provides a potential solution for a battery-free drone system that can fly for a long period in the sky to support the terrestrial communication systems. Finally, a novel system model for effective use of LEO satellite- and cache-assisted UAV communication is proposed and studied. Specifically, caching is provided by the UAV to reduce backhaul congestion, and the LEO satellite assists the UAV’s backhaul link. In this context, we aim to maximize the minimum achievable throughput per ground user (GU) by jointly optimizing cache placement, the UAV’s transmit power, bandwidth allocation, and trajectory with a limited cache capacity and operation time. The outcomes of this work can provide a new design framework for Satellite-UAV-terrestrial communications that includes two tiers, i.e., the backhaul link from satellite to UAV and the access link from UAV to ground users, which imposes new challenges and was not investigated before. [less ▲]

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See detail5G-SpaceLab
Querol, Jorge UL; Abdalla, Abdelrahman UL; Bokal, Zhanna UL et al

Poster (2021, April 19)

The new phase of space exploration involves a growing number of human and robotic missions with varying communication and service requirements. Continuous, maximum coverage of areas where activities are ... [more ▼]

The new phase of space exploration involves a growing number of human and robotic missions with varying communication and service requirements. Continuous, maximum coverage of areas where activities are concentrated and orbiting missions (single spacecraft or constellations) around the Earth, Moon or Mars will be particularly challenging. The standardization of the 5G Non-Terrestrial Networks (NTN) has already begun [1], and nothing prevents 5G from becoming a common communications standard supporting space resource missions [2]. The 5G Space Communications Lab (5G-SpaceLab) is an interdisciplinary experimental platform, funded by the Luxembourg Space Agency and is part of the Space Research Program of SnT. The lab allows users to design and emulate realistic space communications and control scenarios for the next-generation of space applications. The capabilities of the 5G-SpaceLab testbed combine the experience of different disciplines including space communications, space and satellite mission design, and space robotics. The most relevant include the demonstration of SDR 5G NTN terminals including NB-IoT, emulation of space communications channel scenarios (e.g. link budget, delay, Doppler…), small satellite platform and payload design and testing, satellite swarm flight formation, lunar rover and robotic arm control and AI-powered telerobotics. Earth-Moon communications is one of the scenarios demonstrated in the 5G-SpaceLab. Bidirectional communication for the teleoperation of lunar rovers for near real-time operations including data collection and sensors feedback will be tested. AI-based approaches for perception and control will be developed to overcome communication delays and to provide safer, trustworthy, and efficient remote control of the rovers. [1] 3GPP Release 17 Timeline. [Online]. Available: https://www.3gpp.org/release-17 [2] Nokia, Nokia selected by NASA to build first ever cellular network on the Moon. [Online]. Available: https://www.nokia.com/about-us/news/releases/2020/10/19/nokia-selected-by-nasa-to-build-first-ever-cellular-network-on-the-moon/ [less ▲]

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See detail5HTT genotype moderates the influence of early institutional deprivation on emotional problems in adolescence: Evidence from the English and Romanian Adoptee (ERA) study
Kumsta, Robert UL; Stevens, S.; Brookes, K. et al

in Journal of Child Psychology and Psychiatry and Allied Disciplines (2010), 51(7), 755-762

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See detail5th international workshop on principles of engineering service-oriented systems (PESOS 2013)
Bianculli, Domenico UL; Lago, Patricia; Lewis, Grace et al

in Proceedings of the 2013 International Conference on Software Engineering (ICSE '13), San Francisco, CA USA (2013)

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See detail§§ 6 bis 15 WpHG betreffend die Eingriffsbefugnisse der BaFin
Zetzsche, Dirk Andreas UL; Lehmann, M.

in Kapitalmarktrechtskommentar (2021)

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See detail§§ 6 bis 15 WpHG betreffend die Eingriffsbefugnisse der BaFin
Zetzsche, Dirk Andreas UL; Lehmann, M.

in Kapitalmarktrechtkommentar (2019)

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See detail§§ 6 bis 15 WpHG betreffend die Eingriffsbefugnisse der BaFin und Positionskontrollen
Zetzsche, Dirk Andreas UL; Lehmann, Mattias

in Schwark; Zimmer (Eds.) Kapitalmarktrechtskommentar (2021)

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See detail6-way coupling of DEM+CFD+FEM with preCICE
Besseron, Xavier UL; Rousset, Alban UL; Peyraut, Alice et al

Presentation (2020, February)

In this work, we present our preliminary results on the 6-way coupling of 3 numerical solvers: XDEM for the Discrete Element Method (DEM), OpenFOAM for Computation Fluid Dynamics (CFD), and deal.II for ... [more ▼]

In this work, we present our preliminary results on the 6-way coupling of 3 numerical solvers: XDEM for the Discrete Element Method (DEM), OpenFOAM for Computation Fluid Dynamics (CFD), and deal.II for Finite Element Method (FEM). We relied on the existing preCICE adapters for OpenFOAM and deal.II and we have implemented a new preCICE adapter for the eXtended Discrete Element Method (XDEM), an innovative DEM software developed at the University of Luxembourg. The XDEM adapter permits coupling of the particulate phase of DEM with CFD and FEM: - DEM+FEM is a surface coupling that performs the exchange of surface forces and displacement between the particles and a deformable solid; - DEM+CFD is a volume coupling that performs the exchange of porosity, momentum, drag force and buoyancy between the particles and the fluid. Put together with the pre-existing CFD+FEM coupling, we obtain a 6-way coupled multi-physics solver for particles, fluid and deformable solids. We have tested and evaluated our multi-physics solver on the tutorial case “Cylinder with a flap” derived from the benchmarking case of Turek and Hron, that we extended to include a particulate phase solved by XDEM. [less ▲]

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See detail6. Images and Identities
Dell, Paul UL; Amann, Wilhelm UL; Bourg, Viviane UL et al

in IPSE (Ed.) Doing Identity in Luxembourg / Subjective Appropriations - Institutional Attributions- Soco-Cultural Milieus (2011)

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See detail6/ Au-delà de la gestion des références bibliographiques: Zotero - Diacronie
Clavert, Frédéric UL

in Diacronie. Studi di Storia Contemporanea (2012), 2/2012(10),

Né au sein du Centre d’Histoire et des Nouveaux Médias de l’Université de George Mason en Virginie, Zotero se distingue comme étant un logiciel capable de s’adapter au nouveau environnement numérique dans ... [more ▼]

Né au sein du Centre d’Histoire et des Nouveaux Médias de l’Université de George Mason en Virginie, Zotero se distingue comme étant un logiciel capable de s’adapter au nouveau environnement numérique dans lequel travaille l’historien ajourd’hui. Ses multiples fonctionnalités – passées en revue dans ces pages – s’averent être des outils incotournables pour la gestion et l’exploitation des différents corpus de soures. Ces données, issues désormais de tout type de supports, pourront enfin être structurées et organisées aux fins d’une publication, ainsi que réutilisées pour le travail collaboratif et la mise en ligne de bibliographies. [less ▲]

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See detail60 bougies pour un projet impérial original
Scuto, Denis UL

Article for general public (2017)

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See detail§§ 675u - 676c zur Haftung des Zahlungsdienstleisters
Zetzsche, Dirk Andreas UL

in Münchner Kommentar zum Bürgerlichen Gesetzbuch, Teilband 6 (2020)

Detailed reference viewed: 28 (1 UL)