Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailOsiris: Hunting for Integer Bugs in Ethereum Smart Contracts
Ferreira Torres, Christof UL; Schütte, Julian; State, Radu UL

in 34th Annual Computer Security Applications Conference (ACSAC ’18), San Juan, Puerto Rico, USA, December 3-7, 2018 (2018, December)

The capability of executing so-called smart contracts in a decentralised manner is one of the compelling features of modern blockchains. Smart contracts are fully fledged programs which cannot be changed ... [more ▼]

The capability of executing so-called smart contracts in a decentralised manner is one of the compelling features of modern blockchains. Smart contracts are fully fledged programs which cannot be changed once deployed to the blockchain. They typically implement the business logic of distributed apps and carry billions of dollars worth of coins. In that respect, it is imperative that smart contracts are correct and have no vulnerabilities or bugs. However, research has identified different classes of vulnerabilities in smart contracts, some of which led to prominent multi-million dollar fraud cases. In this paper we focus on vulnerabilities related to integer bugs, a class of bugs that is particularly difficult to avoid due to some characteristics of the Ethereum Virtual Machine and the Solidity programming language. In this paper we introduce Osiris – a framework that combines symbolic execution and taint analysis, in order to accurately find integer bugs in Ethereum smart contracts. Osiris detects a greater range of bugs than existing tools, while providing a better specificity of its detection. We have evaluated its performance on a large experimental dataset containing more than 1.2 million smart contracts. We found that 42,108 contracts contain integer bugs. Be- sides being able to identify several vulnerabilities that have been reported in the past few months, we were also able to identify a yet unknown critical vulnerability in a couple of smart contracts that are currently deployed on the Ethereum blockchain. [less ▲]

Detailed reference viewed: 51 (3 UL)
See detailBENELUX, Europe and the Cold War: Asymmetrical Cold War Power Relations and the Integration Process of Europe
Paravantis, Spero UL

Book published by IB Tauris (2018)

What was/is European security in the context of the Cold War? How was and is it conceived? What role did “non-powers” play in European security, and how did they help define it? These were the main ... [more ▼]

What was/is European security in the context of the Cold War? How was and is it conceived? What role did “non-powers” play in European security, and how did they help define it? These were the main questions discussed during the conference held by the C²DH in March 2017. This edited volume brings together the final, peer-reviewed contributions of the participants, and brings them together in a common publication. [less ▲]

Detailed reference viewed: 59 (5 UL)
Full Text
Peer Reviewed
See detailSocial Change for Sustainable Localized Food Sovereignty. Convergence between Prosumers and Ethical Entrepreneurs.
Reckinger, Rachel UL

in Sociologia del Lavoro (2018), 152(4),

Recently, some resourceful community-driven initiatives for local food production and retail have arisen in Luxembourg, where low organic agricultural rates are paradoxically paired with high consumer ... [more ▼]

Recently, some resourceful community-driven initiatives for local food production and retail have arisen in Luxembourg, where low organic agricultural rates are paradoxically paired with high consumer demands. This niche of social innovators is combining agro-ecology with circular economy practices. Four cases of alternative food networks are of interest – studied with qualitative interviews and participant observation. One has been established since the 1980s with 200 employees, partly in social insertion measures. The more recent and smaller initiatives are characterized by a cooperative governance, a community-supported agricultural outlook, hands-on workshops and time-banks, all enabled by social media. These initiatives are more radical in their agro-ecological or permaculture practices, focusing on regenerative land use without relying on imports and fostering the integration of consumers with varying degrees of prosumer involvement, as a politicized step further than mere (possibly industrialized) organic production. [less ▲]

Detailed reference viewed: 81 (0 UL)
Full Text
Peer Reviewed
See detailSequential Resource Distribution Technique for Multi-User OFDM-SWIPT based Cooperative Networks
Gautam, Sumit UL; Lagunas, Eva UL; Chatzinotas, Symeon UL et al

Scientific Conference (2018, December)

In this paper, we investigate resource allocation and relay selection in a dual-hop orthogonal frequency division multiplexing (OFDM)-based multi-user network where amplify-and-forward (AF) enabled relays ... [more ▼]

In this paper, we investigate resource allocation and relay selection in a dual-hop orthogonal frequency division multiplexing (OFDM)-based multi-user network where amplify-and-forward (AF) enabled relays facilitate simultaneous wireless information and power transfer (SWIPT) to the end-users. In this context, we address an optimization problem to maximize the end-users’ sum-rate subjected to transmit power and harvested energy constraints. Furthermore, the problem is formulated for both time-switching (TS) and power-splitting (PS) SWIPT schemes.We aim at optimizing the users’ SWIPT splitting factors as well as sub-carrier–destination assignment, sub-carrier pairing, and relay–destination coupling metrics. This kind of joint evaluation is combinatorial in nature with non-linear structure involving mixed-integer programming. In this vein, we propose a sub-optimal low complex sequential resource distribution (SRD) method to solve the aforementioned problem. The performance of the proposed SRD technique is compared with a semi-random resource allocation and relay selection approach. Simulation results reveal the benefits of the proposed design under several parameter values with various operating conditions to illustrate the efficiency of SWIPT schemes for the proposed techniques. [less ▲]

Detailed reference viewed: 43 (5 UL)
Full Text
Peer Reviewed
See detailPower and Load Optimization in Interference-Coupled Non-Orthogonal Multiple Access Networks
Lei, Lei UL; You, Lei; Yang, Yang UL et al

in IEEE Global Communications Conference (GLOBECOM) 2018 (2018, December)

Detailed reference viewed: 15 (4 UL)
Full Text
Peer Reviewed
See detailCollaborative Data Delivery for Smart City-oriented Mobile Crowdsensing Systems
Vitello, Piergiorgio; Capponi, Andrea UL; Fiandrino, Claudio UL et al

in IEEE Global Communications Conference (GLOBECOM), Abu Dhabi, UAE, 2018 (2018, December)

The huge increase of population living in cities calls for a sustainable urban development. Mobile crowdsensing (MCS) leverages participation of active citizens to improve performance of existing sensing ... [more ▼]

The huge increase of population living in cities calls for a sustainable urban development. Mobile crowdsensing (MCS) leverages participation of active citizens to improve performance of existing sensing infrastructures. In typical MCS systems, sensing tasks are allocated and reported on individual-basis. In this paper, we investigate on collaboration among users for data delivery as it brings a number of benefits for both users and sensing campaign organizers and leads to better coordination and use of resources. By taking advantage from proximity, users can employ device-to-device (D2D) communications like Wi-Fi Direct that are more energy efficient than 3G/4G technology. In such scenario, once a group is set, one of its member is elected to be the owner and perform data forwarding to the collector. The efficiency of forming groups and electing suitable owners defines the efficiency of the whole collaborative-based system. This paper proposes three policies optimized for MCS that are compliant with current Android implementation of Wi-Fi Direct. The evaluation results, obtained using CrowdSenSim simulator, demonstrate that collaborative-based approaches outperform significantly individual-based approaches. [less ▲]

Detailed reference viewed: 37 (2 UL)
See detailLiebe - Krankheit - Wahn: Lyrische Spielarten im Minnesang
Bendheim, Amelie UL

Speeches/Talks (2018)

„Die Liebe verwundet, die Liebe fesselt, die Liebe macht krank, die Liebe lässt schwach werden.“ Dieser ursprünglich theologisch geprägte Gedanke über die Gewalt der Liebe, lässt sich – auf seinen ... [more ▼]

„Die Liebe verwundet, die Liebe fesselt, die Liebe macht krank, die Liebe lässt schwach werden.“ Dieser ursprünglich theologisch geprägte Gedanke über die Gewalt der Liebe, lässt sich – auf seinen bildlichen Kern reduziert – in zahllosen Varianten in der Weltliteratur aufspüren. Eine besonders auffällige Form scheinen dabei jene Texte zu bieten, die Liebe nicht allein als Auslöser, sondern gar selbst als Krankheit darstellen – zumindest implizit, insofern der Zustand des Verliebtseins mit dem Zustand der Krankheit gleichgesetzt wird. Wohl bekannt sind die körperlichen Symptome dieses Liebeszustandes, die in ihrer klassischen Ausprägung im Erbleichen, Erröten, Zittern, in Sprachlähmung sowie im Bluten aus der Nase bestehen und im Mittelalter als minnesiech bezeichnet werden. Erscheint die Liebeskrankheit im Minnesang noch vornehmlich in metaphorischem Gebrauch (s. das gequälte Herz als Beispiel für den Schmerz der Minne), weisen spätere Wörterbucheinträge (vgl. hierzu die Lemmata ‚Liebesfieber’ oder ‚Jungfernkrankheit’) wiederum auf ein stärker körperlich-physiologisches und auch sexuell-erotisches Verständnis von Liebe hin. Krank macht die Minne nun vor allem – und dem mittelalterlichen medizinischen Duktus der Humoralpathologie folgend – dann, wenn das körperliche Begehren nicht befriedigt werden kann. Der hier skizzierte Vortrag will die Vorstellung von Krankheit in einem größeren semantischen Beziehungsgeflecht in den Blick nehmen, das sich in der mhd. Lyrik in bedeutender Weise hervortut: der Verbindung Liebe – Krankheit – Wahn. Der wân als zentrales Symptom der Minnekrankheit löst – so die hier zu erprobende These –den Geist vom versehrten Körper und definiert damit den Übergang von der körperlichen Krankheit(smetapher) zu einer seelischen Zustandsbeschreibung. Die sprachhistorische Herleitung von mhd. wân vermag diese Beobachtung weiter zu untermauern, insofern der Begriff ein zunächst wertneutrales, semantisch vielfältiges Bedeutungsspektrum impliziert, und sich mit ‚Hoffnung, Zuversicht oder Einbildungskraft’ ins Nhd. übertragen ließe. Im krankhaften Minne-wân öffnen sich Denkräume, denen der Minnesang eine literarische Ausgestaltung verleiht; Minne-wân führt damit nicht nur zu körperlicher Versehrtheit, sondern ist eben auch guoter wân, lieber wân, saelden wân – und damit einer der ersten ‚Testräume’ für die Erprobung gedanklicher Spielarten des lyrischen Ichs in der deutschen Dichtung überhaupt. [less ▲]

Detailed reference viewed: 68 (1 UL)
See detailResearching education in Luxembourg (symposium)
Fischbach, Antoine UL

Scientific Conference (2018, November 08)

Detailed reference viewed: 4 (2 UL)
Full Text
Peer Reviewed
See detailA volume-averaged nodal projection method for the Reissner-Mindlin plate model
Ortiz-Bernardin, Alejandro; Köbrich, Philip; Hale, Jack UL et al

in Computer Methods in Applied Mechanics & Engineering (2018), 341

We introduce a novel meshfree Galerkin method for the solution of Reissner-Mindlin plate problems that is written in terms of the primitive variables only (i.e., rotations and transverse displacement) and ... [more ▼]

We introduce a novel meshfree Galerkin method for the solution of Reissner-Mindlin plate problems that is written in terms of the primitive variables only (i.e., rotations and transverse displacement) and is devoid of shear-locking. The proposed approach uses linear maximum-entropy approximations and is built variationally on a two-field potential energy functional wherein the shear strain, written in terms of the primitive variables, is computed via a volume-averaged nodal projection operator that is constructed from the Kirchhoff constraint of the three-field mixed weak form. The stability of the method is rendered by adding bubble-like enrichment to the rotation degrees of freedom. Some benchmark problems are presented to demonstrate the accuracy and performance of the proposed method for a wide range of plate thicknesses. [less ▲]

Detailed reference viewed: 51 (10 UL)
Full Text
Peer Reviewed
See detailPowerMinimizer Symbol-Level Precoding: A Closed-Form Sub-Optimal Solution
Haqiqatnejad, Alireza UL; Kayhan, Farbod UL; Ottersten, Björn UL

in IEEE Signal Processing Letters (2018), 25(11), 1730-1734

In this letter, we study the optimal solution of multiuser symbol-level precoding (SLP) for minimization of the total transmit power under given signal-to-interference-plus noise ratio (SINR) constraints ... [more ▼]

In this letter, we study the optimal solution of multiuser symbol-level precoding (SLP) for minimization of the total transmit power under given signal-to-interference-plus noise ratio (SINR) constraints. Adopting the distance preserving constructive interference regions (DPCIR), we first derive a simplified reformulation of the problem. Then, we analyze the structure of the optimal solution using the Karush-Kuhn-Tucker (KKT) optimality conditions. This leads us to obtain a closed-form sub-optimal SLP solution (CF-SLP) for the original problem. Meanwhile, we obtain the necessary and sufficient condition under which the power minimizer SLP is equivalent to the conventional zero-forcing beamforming (ZFBF). Simulation results show that CF-SLP provides significant gains over ZFBF, while performing quite close to the optimal SLP in scenarios with rather small number of users. The results further indicate that the CF-SLP method has a reduction of order 1000 in computational time compared to the optimal solution. [less ▲]

Detailed reference viewed: 11 (4 UL)
Peer Reviewed
See detailAußerschulisches Lesen und Lesekompetenz Zum Zusammenhang zwischen den Deutsch- und Französisch- Lesekompetenzen von Neuntklässlerinnen und Neuntklässlern und ihren außerschulischen Lesegewohnheiten in Luxemburg.
Reichert, Monique UL; Krämer, Charlotte UL; Rivas, Salvador UL et al

Scientific Conference (2018, November)

In Luxemburg erreichen viele Jugendliche ein gutes Lesekompetenzniveau nicht nur in einer, sondern gleich in zwei Sprachen. Allerdings wird wiederholt darauf hingewiesen, dass die Lesekompetenzen in ... [more ▼]

In Luxemburg erreichen viele Jugendliche ein gutes Lesekompetenzniveau nicht nur in einer, sondern gleich in zwei Sprachen. Allerdings wird wiederholt darauf hingewiesen, dass die Lesekompetenzen in Luxemburg stark mit dem familiären Hintergrund der Schülerinnen und Schüler zusammenhängen. Die vorliegende Studie soll jedoch über die Darstellung der Zusammenhänge zwischen den Deutsch- und Französisch-Lesekompetenzen und Einflussfaktoren wie sozio-ökonomischem Hintergrund, Migrationsstatus und Muttersprache hinausgehen. In der Tat stellt sich die Frage, ob es Faktoren gibt, die sich positiv auf das Lesekompetenzniveau der Schülerinnen und Schüler auswirken und auf die sie – anders als bei diesen mittlerweile gut belegten Faktoren – selbst Einfluss nehmen können? Das Leseverhalten Jugendlicher stellt hierfür einen naheliegenden Ansatzpunkt dar. Somit wurden die Schülerinnen und Schüler während der ÉpStan 2016 nicht nur zu ihrem familiären, schulischen und persönlichen Hintergrund befragt, sondern erstmals auch zu ihrem außerschulischen Leseverhalten. Hierbei wurde erfasst, wie häufig sie in ihrer Freizeit Texte unterschiedlicher Art (z. B. Erzählungen, Sachtexte, Zeitungsartikel, Foreneinträge oder Emails) lesen, und in welchen Sprachen sie dies tun. Mittels verschiedener Regressionsanalysen wurde der familiäre Hintergrund der Jugendlichen, ihr Leseverhalten, sowie ihr Lesekompetenzniveau im Deutschen und Französischen zueinander in Bezug gesetzt. Die aus diesen Analysen hervorgehenden Ergebnisse belegen eindrücklich, dass neben dem familiären Hintergrund auch die Lesehäufigkeit und die Sprache, in der die Schülerinnen und Schüler üblicherweise lesen, von Bedeutung für das erreichte Lesekompetenzniveau sind. Darüber hinaus haben insbesondere die Textsorten, mit denen sich die Jugendlichen in ihrer Freizeit auseinandersetzen, entscheidenden Einfluss auf ihre Deutsch- und ihre Französisch-Lesekompetenz. Insbesondere die Häufigkeit, mit der Jugendliche angeben, narrative Texte (wie Geschichten, Romane oder Erzählungen) zu lesen, steht deutlich in positivem Zusammenhang mit ihrer Lesekompetenz in beiden Sprachen. Der Vortrag schließt mit einer Diskussion bezüglich der außerordentlich hohen Attraktivität von digitalen Textsorten bei Kindern und Jugendlichen, und den Möglichkeiten, diese Vielfalt an primär kommunikativ bzw. interaktiv ausgerichteten Lesematerialien als lebensnahe, pädagogische „Sprungbretter“ zu nutzen, mit deren Hilfe zukünftige Leserinnen und Leser an zunehmend komplexere Texte herangeführt werden könnten. [less ▲]

Detailed reference viewed: 9 (3 UL)
Peer Reviewed
See detailConstructions contestées et contrastées de la notion de terroir. Symbolique Politique, Savoir Scientifique, Typicité Culturale et Culturelle
Reckinger, Rachel UL

in Yengué, Louis; Stengel, Kilien (Eds.) Terroir viticole. Espace et figures de qualité (2018)

Detailed reference viewed: 45 (2 UL)
See detailEducational assessment and its prospects in the 21st century
Greiff, Samuel UL

Speeches/Talks (2018)

Detailed reference viewed: 11 (1 UL)
See detailSustainability: problematizing fragility and ephemerality in digital research - Workshop
Schafer, Valerie UL; Fickers, Andreas UL

Presentation (2018, October 26)

404 not found, closed and opaque corpora, websites disappearance after a few years, obsolete tools, problems of maintenance … this workshop wishes to explore the instability of data, of their digital ... [more ▼]

404 not found, closed and opaque corpora, websites disappearance after a few years, obsolete tools, problems of maintenance … this workshop wishes to explore the instability of data, of their digital (digitalized or/and born-digital) heritage, of digital technologies and tools, the numerous transformations of devices, platforms, terms of use and the tensions between this instability and the necessary stability and reproducibility of research. How should researchers deal at the same time with the ephemeral, the flow, the obsolescence and the concern of knowledge production? How is it possible to reconciliate the temporality of research and the short cycles of technologies? This workshop aims at introducing and identifying the challenges of sustainability and durability which are too often underestimated in digital research and rarely presented to students when introducing tools and research methods. This 120 minutes workshop will be organized in three parts as follows: - Identifying the levels, steps, in which sustainability and durability of a digital research are challenged, from the shaping and sharing of corpora to the maintenance of research results and digital productions. This will be based on the participants experiences and on several examples of research projects; - Mapping the issues and existing solutions such as digital research infrastructures, permanent identifiers, licenses, but also obstacles and limits (such as author rights …) that researchers have to face or take into account; - Creating practical guidelines that could be used by scholars and students. This workshop expands a research project conducted by Christine Barats (Céditec, Université Paris- Est Créteil), Andreas Fickers (Head of C2DH, University of Luxembourg), Valérie Schafer (C2DH, University of Luxembourg). [less ▲]

Detailed reference viewed: 13 (0 UL)
Full Text
Peer Reviewed
See detailGuideline-based and bioinformatic reassessment of lesion-associated gene and variant pathogenicity in focal human epilepsies
Niestroj, Lisa-Marie; Du, Juanjiangmeng; Nothnagel, Michael et al

in Epilepsia (2018)

Objective: Increasing availability of surgically resected brain tissue from patients with focal epilepsy and Focal Cortical Dysplasia (FCD) or low-grade glio-neuronal tumors has fostered large-scale ... [more ▼]

Objective: Increasing availability of surgically resected brain tissue from patients with focal epilepsy and Focal Cortical Dysplasia (FCD) or low-grade glio-neuronal tumors has fostered large-scale genetic examination. However, assessment of pathogenicity of germline and somatic variants remains difficult. Here, we present a state of the art evaluation of reported genes and variants associated with epileptic brain lesions. Methods: We critically re-evaluated the pathogenicity for all neuropathology-associated variants reported to date in PubMed and ClinVar databases including 101 neuropathology-associated missense variants encompassing 11 disease-related genes. We assessed gene variant tolerance and classified all identified missense variants according to guidelines from the American College of Medical Genetics and Genomics (ACMG). We further extended the bioinformatic variant prediction by introducing a novel gene-specific deleteriousness ranking for prediction scores. Results: Application of ACMG guidelines and in silico gene variant tolerance analysis classified only seven out of 11 genes to be likely disease-associated according to the reported a disease mechanism, while 61 (60.4%) of 101 variants of those genes were classified as of uncertain significance (VUS), 37 (36.6%) as being likely pathogenic (LP) and 3 (3%) as being pathogenic (P). Significance: We concluded that the majority of neuropathology-associated variants reported to date do not have enough evidence to be classified as pathogenic. Interpretation of lesion-associated variants remains challenging and application of current ACMG guidelines is recommended for interpretation and prediction. [less ▲]

Full Text
Peer Reviewed
See detailThe long and winding road to inclusion in Higher Education
Limbach-Reich, Arthur UL

Scientific Conference (2018, October 18)

Detailed reference viewed: 16 (3 UL)
See detailEin Atlas der Stadtgeschichte Luxemburgs - digital und interaktiv. Ein Werkstattbericht
Uhrmacher, Martin UL; Kass, Steve UL

Scientific Conference (2018, October 18)

Seit 2016 widmet sich ein Forschungsprojekt der Universität, in Zusammenarbeit mit der Stadt Luxemburg, der Erstellung eines historischen Atlas. Dieser wird die städtische Entwicklung seit Beginn des 19 ... [more ▼]

Seit 2016 widmet sich ein Forschungsprojekt der Universität, in Zusammenarbeit mit der Stadt Luxemburg, der Erstellung eines historischen Atlas. Dieser wird die städtische Entwicklung seit Beginn des 19. Jahrhunderts in Form von digitalen und interaktiven Karten im Internet darstellen. Fünf Zeitschnitte sind vorgesehen, um die tiefgreifenden Wandlungsprozesse Luxemburgs zu analysieren und zugleich auch spannend und anschaulich zu präsentieren: Von der Festungsstadt, die das militärische Korsett erst nach 1867 ablegen konnte, über eine moderne europäischen Hauptstadt des frühen 20. Jahrhunderts bis hin zu einem der Hauptverwaltungssitze der EU und einem internationalen Finanzzentrum. Ein Jahr vor der offiziellen Veröffentlichung des Atlas werden erste Ergebnisse präsentiert. Dies ermöglicht einen Einblick in die historische Forschungsarbeit sowie in die digitale Aufbereitung alter Karten für die Publikation im Internet. [less ▲]

Detailed reference viewed: 10 (1 UL)