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See detailPricing Perspective for SWIPT in OFDM-based Multi-User Wireless Cooperative Systems
Gautam, Sumit UL; Lagunas, Eva UL; Vuppala, Satyanarayana UL et al

Scientific Conference (2019, April)

We propose a novel formulation for joint maximization of total weighted sum-spectral efficiency and weighted sum-harvested energy to study Simultaneous Wireless Information and Power Transfer (SWIPT) from ... [more ▼]

We propose a novel formulation for joint maximization of total weighted sum-spectral efficiency and weighted sum-harvested energy to study Simultaneous Wireless Information and Power Transfer (SWIPT) from a pricing perspective. Specifically, we consider that a transmit source communicates with multiple destinations using Orthogonal Frequency Division Multiplexing (OFDM) system within a dual-hop relay-assisted network, where the destination nodes are capable of jointly decoding information and harvesting energy from the same radio-frequency (RF) signal using either the time-switching (TS) or power-splitting (PS) based SWIPT receiver architectures. Computation of the optimal solution for the aforementioned problem is an extremely challenging task as joint optimization of several network resources introduce intractability at high numeric values of relays, destination nodes and OFDM sub-carriers. Therefore, we present a suitable algorithm with sub-optimal results and good performance to compute the performance of joint data processing and harvesting energy under fixed pricing methods by adjusting the respective weight factors, motivated by practical statistics. Furthermore, by exploiting the binary options of the weights, we show that the proposed formulation can be regulated purely as a sum-spectral efficiency maximization or solely as a sum-harvested energy maximization problem. Numerical results illustrate the benefits of the proposed design under several operating conditions and parameter values. [less ▲]

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See detailLooking into the Past: Evaluating the Effect of Time Gaps in a Personalized Sentiment Model
Guo, Siwen UL; Höhn, Sviatlana UL; Schommer, Christoph UL

in ACM/SIGAPP Symposium On Applied Computing, Limassol 8-12 April 2019 (2019, April)

This paper concerns personalized sentiment analysis, which aims at improving the prediction of the sentiment expressed in a piece of text by considering individualities. Mostly, this is done by relating ... [more ▼]

This paper concerns personalized sentiment analysis, which aims at improving the prediction of the sentiment expressed in a piece of text by considering individualities. Mostly, this is done by relating to a person’s past expressions (or opinions), however the time gaps between the messages are not considered in the existing works. We argue that the opinion at a specific time point is affected more by recent opinions that contain related content than the earlier or unrelated ones, thus a sentiment model ought to include such information in the analysis. By using a recurrent neural network with an attention layer as a basic model, we introduce three cases to integrate time gaps in the model. Evaluated on Twitter data with frequent users, we have found that the performance is improved the most by including the time information in the Hawkes process, and it is also more effective to add the time information in the attention layer than at the input. [less ▲]

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See detailFog Computing as the Key for Seamless Connectivity Handover in Future Vehicular Networks
Palattella, Maria Rita UL; Soua, Ridha UL; Abdelmajid, Khelil et al

in The 34th ACM Symposium On Applied Computing (SAC (2019, April)

Detailed reference viewed: 99 (15 UL)
See detailOverprosecution and Negotiated Justice in Europe
Ligeti, Katalin UL; Robinson, Gavin UL

in Van Kempen, Piet Hein (Ed.) Overuse in the Criminal Justice System: On Criminalization, Prosecution and Imprisonment (2019)

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See detailSecurity – Visible, Yet Unseen? How Displaying Security Mechanisms Impacts User Experience and Perceived Security
Distler, Verena UL; Zollinger, Marie-Laure UL; Lallemand, Carine UL et al

in Proceedings of ACM CHI Conference on Human Factors in Computing Systems (CHI2019) (2019, April)

An unsolved debate in the field of usable security concerns whether security mechanisms should be visible, or blackboxed away from the user for the sake of usability. However, tying this question to ... [more ▼]

An unsolved debate in the field of usable security concerns whether security mechanisms should be visible, or blackboxed away from the user for the sake of usability. However, tying this question to pragmatic usability factors only might be simplistic. This study aims at researching the impact of displaying security mechanisms on user experience (UX) in the context of e-voting. Two versions of an e-voting application were designed and tested using a between-group experimental protocol (N=38). Version D displayed security mechanisms, while version ND did not reveal any security-related information. We collected data on UX using standardised evaluation scales and semi-structured interviews. Version D performed better overall in terms of UX and need fulfilment. Qualitative analysis of the interviews gives further insights into factors impacting perceived security. Our study adds to existing research suggesting a conceptual shift from usability to UX and discusses implications for designing and evaluating secure systems. [less ▲]

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See detailReview for "Journal of Sports Sciences"
Bund, Andreas UL

in Journal of Sports Sciences (2019)

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See detailEdito Varia
Dablanc, Laetitia; Schafer, Valerie UL

in Flux: Cahiers Scientifiques Internationaux Réseaux et Territoires (2019), 115(1), 82

Au cœur de ce numéro de Varia le lecteur découvrira trois analyses originales sur l’urbain, qu’elles concernent l’urbanisme commercial, la grande mobilité domicile-travail (qui fait intervenir deux aires ... [more ▼]

Au cœur de ce numéro de Varia le lecteur découvrira trois analyses originales sur l’urbain, qu’elles concernent l’urbanisme commercial, la grande mobilité domicile-travail (qui fait intervenir deux aires urbaines) ou encore les mobilités du périurbain. [less ▲]

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See detailExploring the "French Web" of the 1990s
Schafer, Valerie UL

in Brügger, Niels; Laursen, Ditte (Eds.) The Historical Web and Digital Humanities: The Case of National Web Domains (2019)

This chapter draws from the experience of the collective French Web90 project to show the approaches, tools, and methodologies required to sketch a broad historical picture of the French Web during the ... [more ▼]

This chapter draws from the experience of the collective French Web90 project to show the approaches, tools, and methodologies required to sketch a broad historical picture of the French Web during the 1990s. It also describes the limits and challenges we met during its realisation. Uncertainties about the perimeter of the French Web and its archives, data overload, progressive learning of a particular digital literacy, specific features of born-digital heritage (Newsgroups and Web archives), and using the tools for its exploration and analysis are at the heart of this study, which has progressively refined and adapted its ambitions and methodologies, notably by using methods and tools from the Digital Humanities. [less ▲]

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See detailCollaborative Distributed Q-Learning for RACH Congestion Minimization in Cellular IoT Networks
Sharma, Shree Krishna UL; Wang, Xianbin

in IEEE Communications Letters (2019), 23(4), 600-603

Due to infrequent and massive concurrent access requests from the ever-increasing number of machine-type communication (MTC) devices, the existing contention-based random access (RA) protocols, such as ... [more ▼]

Due to infrequent and massive concurrent access requests from the ever-increasing number of machine-type communication (MTC) devices, the existing contention-based random access (RA) protocols, such as slotted ALOHA, suffer from the severe problem of random access channel (RACH) congestion in emerging cellular IoT networks. To address this issue, we propose a novel collaborative distributed Q-learning mechanism for the resource-constrained MTC devices in order to enable them to find unique RA slots for their transmissions so that the number of possible collisions can be significantly reduced. In contrast to the independent Q-learning scheme, the proposed approach utilizes the congestion level of RA slots as the global cost during the learning process and thus can notably lower the learning time for the low-end MTC devices. Our results show that the proposed learning scheme can significantly minimize the RACH congestion in cellular IoT networks. [less ▲]

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See detailQuantum Machine Learning for 6G Communication Networks: State-of-the-Art and Vision for the Future
Nawaz, Sayed Junaid; Sharma, Shree Krishna UL; Wyne, Shurjeel et al

in IEEE Access (2019)

The upcoming 5th Generation (5G) of wireless networks is expected to lay a foundation of intelligent networks with the provision of some isolated Artificial Intelligence (AI) operations. However, fully ... [more ▼]

The upcoming 5th Generation (5G) of wireless networks is expected to lay a foundation of intelligent networks with the provision of some isolated Artificial Intelligence (AI) operations. However, fully-intelligent network orchestration and management for providing innovative services will only be realized in Beyond 5G (B5G) networks. To this end, we envisage that the 6th Generation (6G) of wireless networks will be driven by on-demand self-reconfiguration to ensure a many-fold increase in the network performanceandservicetypes.Theincreasinglystringentperformancerequirementsofemergingnetworks may finally trigger the deployment of some interesting new technologies such as large intelligent surfaces, electromagnetic-orbital angular momentum, visible light communications and cell-free communications – tonameafew.Ourvisionfor6Gis–amassivelyconnectedcomplexnetworkcapableofrapidlyresponding to the users’ service calls through real-time learning of the network state as described by the network-edge (e.g., base-station locations, cache contents, etc.), air interface (e.g., radio spectrum, propagation channel, etc.), and the user-side (e.g., battery-life, locations, etc.). The multi-state, multi-dimensional nature of the network state, requiring real-time knowledge, can be viewed as a quantum uncertainty problem. In this regard, the emerging paradigms of Machine Learning (ML), Quantum Computing (QC), and Quantum ML (QML) and their synergies with communication networks can be considered as core 6G enablers. Considering these potentials, starting with the 5G target services and enabling technologies, we provide a comprehensivereviewoftherelatedstate-of-the-artinthedomainsofML(includingdeeplearning),QCand QML, and identify their potential benefits, issues and use cases for their applications in the B5G networks. Subsequently,weproposeanovelQC-assistedandQML-basedframeworkfor6Gcommunicationnetworks whilearticulatingitschallengesandpotentialenablingtechnologiesatthenetwork-infrastructure,networkedge, air interface and user-end. Finally, some promising future research directions for the quantum- and QML-assisted B5G networks are identified and discussed. [less ▲]

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See detailDie Pariser Vorortverträge (1919-1923) in den europäischen Erinnerungskulturen
Brüll, Christoph UL

Conference given outside the academic context (2019)

Detailed reference viewed: 22 (0 UL)
See detailKarl der Grosse und Aachen in Europa. Eine kleine Mythologie
Brüll, Christoph UL

Conference given outside the academic context (2019)

Detailed reference viewed: 19 (1 UL)
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See detailMieux Comprendre le choix de demande d'asile au Luxembourg
Joxhe, Majlinda UL

Article for general public (2019)

Detailed reference viewed: 67 (0 UL)
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See detailInklusion, Arbeitsmarkt und Neoliberalismus im Zeitalter der VN-BRK
Limbach-Reich, Arthur UL

Conference given outside the academic context (2019)

Detailed reference viewed: 85 (8 UL)
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See detailGraft materials provide greater static strength to medial opening wedge high tibial osteotomy than when no graft is included
Belsey, James; Diffo Kaze, Arnaud UL; Jobson, Simon et al

in Journal of Experimental Orthopaedics (2019), 6(13),

Background The purpose of this study was to compare the stability of medial opening-wedge high tibial osteotomy (MOWHTO) with and without different graft materials. Good clinical and radiological outcomes ... [more ▼]

Background The purpose of this study was to compare the stability of medial opening-wedge high tibial osteotomy (MOWHTO) with and without different graft materials. Good clinical and radiological outcomes have been demonstrated when either using or not using graft materials during MOWHTO. Variations in the biomechanical properties of different graft types, regarding the stability they provide a MOWHTO, have not been previously investigated. Methods A 10 mm biplanar MOWHTO was performed on 15 artificial sawbone tibiae, which were fixed using the Activmotion 2 plate. Five bones had OSferion60 wedges (synthetic group), five had allograft bone wedges (allograft group), and five had no wedges (control group) inserted into the osteotomy gap. Static compression was applied axially to each specimen until failure of the osteotomy. Ultimate load, horizontal and vertical displacements were measured and used to calculate construct stiffness and valgus malrotation of the tibial head. Results The synthetic group failed at 6.3 kN, followed by the allograft group (6 kN), and the control group (4.5 kN). The most valgus malrotation of the tibial head was observed in the allograft group (2.6°). The synthetic group showed the highest stiffness at the medial side of the tibial head (9.54 kN·mm− 1), but the lowest stiffness at the lateral side (1.59 kN·mm-1). The allograft group showed high stiffness on the medial side of the tibial head (7.54 kN·mm− 1) as well as the highest stiffness on the lateral side (2.18 kN·mm− 1). Conclusions The use of graft materials in MOWHTO results in superior material properties compared to the use of no graft. The static strength of MOWHTO is highest when synthetic grafts are inserted into the osteotomy gap. Allograft wedges provide higher mechanical strength to a MOWHTO than when no graft used. In comparison to the synthetic grafts, allograft wedges result in the stiffness of the osteotomy being more similar at the medial and lateral cortices. [less ▲]

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See detailSingle-cell transcriptomics reveals multiple neuronal cell types in human midbrain-specific organoids
Smith, Lisa M.; Magni, Stefano UL; Grzyb, Kamil UL et al

E-print/Working paper (2019)

Human stem cell-derived organoids have great potential for modelling physiological and pathological processes. They recapitulate in vitro the organisation and function of a respective organ or part of an ... [more ▼]

Human stem cell-derived organoids have great potential for modelling physiological and pathological processes. They recapitulate in vitro the organisation and function of a respective organ or part of an organ. Human midbrain organoids (hMOs) have been described to contain midbrain-specific dopaminergic neurons that release the neurotransmitter dopamine. However, the human midbrain contains also additional neuronal cell types, which are functionally interacting with each other. Here, we analysed hMOs at high-resolution by means of single-cell RNA-sequencing (scRNA-seq), imaging and electrophysiology to unravel cell heterogeneity. Our findings demonstrate that hMOs show essential neuronal functional properties as spontaneous electrophysiological activity of different neuronal subtypes, including dopaminergic, GABAergic, and glutamatergic neurons. Recapitulating these in vivo features makes hMOs an excellent tool for in vitro disease phenotyping and drug discovery. [less ▲]

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See detailOn quasitrivial semigroups
Devillet, Jimmy UL

Presentation (2019, March 27)

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See detailInference in Conditional Moment Restriction Models When there is Selection Due to Stratification
Cosma, Antonio UL; Kostyrka, André UL; Tripathi, Gautam UL

in Huynh, Kim P.; Jacho-Chávez, David T.; Tripathi, Gautam (Eds.) The Econometrics of Complex Survey Data (2019)

We show how to use a smoothed empirical likelihood approach to conduct efficient semiparametric inference in models characterized as conditional moment equalities when data is collected by variable ... [more ▼]

We show how to use a smoothed empirical likelihood approach to conduct efficient semiparametric inference in models characterized as conditional moment equalities when data is collected by variable probability sampling. Results from a simulation experiment suggest that the smoothed empirical likelihood based estimator can estimate the model parameters very well in small to moderately sized stratified samples. [less ▲]

Detailed reference viewed: 55 (3 UL)