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See detailLuxembourg Analysis
Danescu, Elena UL; Kmec, Sonja UL

in Hartley, Cathy (Ed.) WESTERN EUROPE 2018 (2017)

With a long tradition of political stability and social democracy, a creative development model, skilled human capital and a culture of consensus, Luxembourg is at the forefront of Europe. Its main ... [more ▼]

With a long tradition of political stability and social democracy, a creative development model, skilled human capital and a culture of consensus, Luxembourg is at the forefront of Europe. Its main strategic challenge is how to achieve economic diversification while maintaining the sustainability of the Luxembourg social model. The country has embarked on the "third industrial revolution", with innovation as the main driver of sustainable growth and the University of Luxembourg as a major player. [less ▲]

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See detailL’événement énonciatif en sémiotique de l’image : de Roland Barthes à la sémiotique tensive
Colas-Blaise, Marion UL; Dondero, Maria Giulia

in La part de l'oeil (2017)

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See detailEstimating Urban Road Traffic States Using Mobile Network Signaling Data
Derrmann, Thierry UL; Frank, Raphaël UL; Viti, Francesco UL et al

in Derrmann, Thierry; Frank, Raphaël; Viti, Francesco (Eds.) et al Estimating Urban Road Traffic States Using Mobile Network Signaling Data (2017, October)

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used ... [more ▼]

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used in analyses, but also handovers between different locations that reflect mobility. In this work, we investigate if handovers can be used as a proxy metric for flows in the underlying road network, especially in urban environments. More precisely, we show that characteristic profiles of handovers within and between clusters of mobile network cells exist. We base these profiles on models from road traffic flow theory, and show that they can be used for traffic state estimation using floating-car data as ground truth. The presented model can be beneficial in areas with good mobile network coverage but low road traffic counting infrastructure, e.g. in developing countries, but also serve as an additional predictor for existing traffic state monitoring systems. [less ▲]

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See detailLIPS vs MOSA: a Replicated Em- pirical Study on Automated Test Case Generation
Panichella, Annibale UL; Kifetew, Fitsum; Tonella, Paolo

in International Symposium on Search Based Software Engineering (SSBSE) 2017 (2017, September 09)

Replication is a fundamental pillar in the construction of scientific knowledge. Test data generation for procedural programs can be tackled using a single-target or a many-objective approach. The ... [more ▼]

Replication is a fundamental pillar in the construction of scientific knowledge. Test data generation for procedural programs can be tackled using a single-target or a many-objective approach. The proponents of LIPS, a novel single-target test generator, conducted a preliminary empirical study to compare their approach with MOSA, an alternative many-objective test generator. However, their empirical investigation suffers from several external and internal validity threats, does not consider complex programs with many branches and does not include any qualitative analysis to interpret the results. In this paper, we report the results of a replication of the original study designed to address its major limitations and threats to validity. The new findings draw a completely different picture on the pros and cons of single-target vs many-objective approaches to test case generation. [less ▲]

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See detailMultiscale Modelling of Damage and Fracture in Discrete Materials Using a Variational Quasicontinuum Method
Rokos, Ondrej; Peerlings, Ron; Beex, Lars UL et al

Scientific Conference (2017, September 05)

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See detailIs Big Data Sufficient for a Reliable Detection of Non-Technical Losses?
Glauner, Patrick UL; Migliosi, Angelo UL; Meira, Jorge Augusto UL et al

in Proceedings of the 19th International Conference on Intelligent System Applications to Power Systems (ISAP 2017) (2017, September)

Non-technical losses (NTL) occur during the distribution of electricity in power grids and include, but are not limited to, electricity theft and faulty meters. In emerging countries, they may range up to ... [more ▼]

Non-technical losses (NTL) occur during the distribution of electricity in power grids and include, but are not limited to, electricity theft and faulty meters. In emerging countries, they may range up to 40% of the total electricity distributed. In order to detect NTLs, machine learning methods are used that learn irregular consumption patterns from customer data and inspection results. The Big Data paradigm followed in modern machine learning reflects the desire of deriving better conclusions from simply analyzing more data, without the necessity of looking at theory and models. However, the sample of inspected customers may be biased, i.e. it does not represent the population of all customers. As a consequence, machine learning models trained on these inspection results are biased as well and therefore lead to unreliable predictions of whether customers cause NTL or not. In machine learning, this issue is called covariate shift and has not been addressed in the literature on NTL detection yet. In this work, we present a novel framework for quantifying and visualizing covariate shift. We apply it to a commercial data set from Brazil that consists of 3.6M customers and 820K inspection results. We show that some features have a stronger covariate shift than others, making predictions less reliable. In particular, previous inspections were focused on certain neighborhoods or customer classes and that they were not sufficiently spread among the population of customers. This framework is about to be deployed in a commercial product for NTL detection. [less ▲]

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See detailA Model-Driven Approach to Trace Checking of Pattern-based Temporal Properties
Dou, Wei; Bianculli, Domenico UL; Briand, Lionel UL

in Proceedings of the ACM/IEEE 20th International Conference on Model Driven Engineering Languages and Systems (MODELS 2017 ) (2017, September)

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See detailJoanAudit: A Tool for Auditing Common Injection Vulnerabilities
Thome, Julian UL; Shar, Lwin Khin UL; Bianculli, Domenico UL et al

in 11th Joint Meeting of the European Software Engineering Conference and the ACM SIGSOFT Symposium on the Foundations of Software Engineering (2017, September)

JoanAudit is a static analysis tool to assist security auditors in auditing Web applications and Web services for common injection vulnerabilities during software development. It automatically identifies ... [more ▼]

JoanAudit is a static analysis tool to assist security auditors in auditing Web applications and Web services for common injection vulnerabilities during software development. It automatically identifies parts of the program code that are relevant for security and generates an HTML report to guide security auditors audit the source code in a scalable way. JoanAudit is configured with various security-sensitive input sources and sinks relevant to injection vulnerabilities and standard sanitization procedures that prevent these vulnerabilities. It can also automatically fix some cases of vulnerabilities in source code — cases where inputs are directly used in sinks without any form of sanitization — by using standard sanitization procedures. Our evaluation shows that by using JoanAudit, security auditors are required to inspect only 1% of the total code for auditing common injection vulnerabilities. The screen-cast demo is available at https://github.com/julianthome/joanaudit. [less ▲]

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See detailWhat do we need to say about a design method?
Gericke, Kilian UL; Eckert, Claudia; Stacey, Martin

in Proceedings of the 21st International Conference on Engineering Design (2017, August)

Method development is one of the raisons d’etre of engineering design research and method uptake by industry is perceived as an important success criterion. This paper argues that one of the problems with ... [more ▼]

Method development is one of the raisons d’etre of engineering design research and method uptake by industry is perceived as an important success criterion. This paper argues that one of the problems with methods is the lack of clarity about what is actually proposed to industry and the academic community when a new method is put forward, in terms of how detailed, strict, precise and rigorous the method is and what it can deliver. This paper puts the concept of method in the context of related concepts and proposes a multi-level model of the elements of a method to argue that a contribution on each of these levels can be of value and that the introduction of methods can fail on each of these levels. Implications thereof for industry and academia are discussed, concluding that a clear description of methods and their intended use is important for enabling proper validation of each of the method’s elements and for communicating methods to academia and industry. [less ▲]

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See detailAn engineering approach to mapping meanings in products and services
Waltersdorfer, Gregor UL; Gericke, Kilian UL; Desmet, Pieter M. A. et al

Scientific Conference (2017, August)

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See detailRandom Phase Center Motion Technique for Enhanced Angle-Doppler Discrimination Using MIMO Radars
Hammes, Christian UL; Shankar, Bhavani UL; Nijsure, Yogesh UL et al

Scientific Conference (2017, August)

A random Phase Center Motion (PCM) technique is presented in this paper, based on Frequency Modulated Continuous Wave (FMCW) radar, in order to suppress the angle- Doppler coupling in Time Division ... [more ▼]

A random Phase Center Motion (PCM) technique is presented in this paper, based on Frequency Modulated Continuous Wave (FMCW) radar, in order to suppress the angle- Doppler coupling in Time Division Multiplex (TDM) Multiple- Input-Multiple-Output (MIMO) radar when employing sparse array structures. The presented approach exploits an apparently moving transmit platform or PCM due to spatio-temporal transmit array modulation. In particular, the work considers a framework utilizing a random PCM trajectory. The statistical characterization of the random PCM trajectory is devised, such that the PCM and the target motion coupling is minimal, while the angular resolution is increased by enabling the virtual MIMO concept. In more details, this paper discusses sidelobe suppression approaches within the angle-Doppler Ambiguity Function (AF) by introducing a phase center probability density function within the array. This allows for enhanced discrimination of multiple targets. Simulation results demonstrate the suppression angle- Doppler coupling by more than 30 dB, even though spatiotemporal transmit array modulation is done across chirps which leads usually to strong angle-Doppler coupling. [less ▲]

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See detailThe role of international organisations in the New Math reform process
Nadimi Amiri, Shaghayegh UL

Scientific Conference (2017, August)

This paper studies a particular school reform that travelled over countries and continents. The target reform of this paper is the New Math reform, which started in the United States and travelled through ... [more ▼]

This paper studies a particular school reform that travelled over countries and continents. The target reform of this paper is the New Math reform, which started in the United States and travelled through many European countries. This article is part of my PhD project. I previously presented some of the results in different conferences, for instance: (Nadimi, 2015a, 2015b, 2016). The present paper studies the role of the international institutions in the adaptation of the reform in Luxembourg In 1958, the School Mathematics Study Group (SMSG) in the United States started a series of mathematics reform under the title “the New Math reform”. The aim of this reform plan was to promote the “problem solving” abilities in students (Phillips, 2014, pp. 16- 59). Many of mathematicians and math educators who became a member of the SMSG, had already started working on a new system of math education at the University of Chicago since 1955. However, the launch of Sputnik satellite by the USSR in 1957 gave the opportunity to trigger the New Math reform. The origin of the New Math reform was the ‘modern mathematics’ of the French Bourbaki group. A group of French mathematicians, since 1935, under the pseudonym Nicolas Bourbaki founded the “modern mathematics” by publishing the series of Elements of Mathematics (Bourbaki's_homepage). The reform came back to its land of origin through a conference organised by OEEC (Organisation for European Economic Co-operation) in the Royaumont abbey in Paris to foster the reform movement in Europe (OECD, 1961). The official title of the conference was “New thinking in mathematics education”, but it is known as the “Royaumont seminar”. OECD (the Organisation succeeding the OEEC) published the proceeding of the conference and organised other following conferences. The fact that OEEC/OECD hosts these conferences shows the politico-economic aspect of this reform. (Tröhler, 2015, p. 6) indicates that organisations like OEEC were created to link the national and the international, to create a global sphere, and to form an institutional or organisational channel to transfer desired ideas, policies, and curricula. The practical implementations of the New Math reform, in Europe, were discussed in two international organisations: ICMI (International Commission on Mathematical Instruction), founded in 1908, and CIEAEM (Commission Internationale pour l’Étude et l’Améloration de l’Enseignement des Mathématiques), established in 1950 (Vanpaemel, 2012). Furthermore, there were also local institutions, such as Centre Belge de Pédagogie de la Mathématique (CBPM). This centre had a close collaboration with Luxembourgian teachers and school stakeholders. This paper reviews the process of the New Math reform in Luxembourg by focusing on the interactions between the international institutions and the local school system. By telling the story of Luxembourg, the paper reveals a part of history related to the acts and efforts of the mentioned international organisations in the dissemination of the New Math reform idea in Europe. It shows how the national and international interactions could help the advancement of the reform and where the collaboration met challenges. The central question that shapes the paper is that up to what point the international cooperation of Luxembourgian stakeholders could be influential at the national level. This can be an example of how the acts and efforts of international organisations interact with the local interested parties in the development of an educational idea. [less ▲]

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See detaileXtended Variational Quasicontinuum Methodology for Modelling of Crack Propagation in Discrete Lattice Systems
Rokos, Ondrej; Peerlings, Ron; Zeman, Jan et al

Scientific Conference (2017, July 17)

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See detailAn equation-free multiscale method: a result of extending the quasicontinuum method to irregular structures
Beex, Lars UL; Kerfriden, Pierre

Scientific Conference (2017, July 16)

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See detailA Global Vertical Land Movement Data Set from a Combination of Global Navigation Satellite System Solutions
Hunegnaw, Addisu UL; Teferle, Felix Norman UL; Abraha, Kibrom Ebuy UL et al

Poster (2017, July 13)

Coastal sea-level measurements by tide gauges provide the longest instrumental records of sea-levels with some stretching from the 19th century to present. The derived mean sea-level (MSL) records provide ... [more ▼]

Coastal sea-level measurements by tide gauges provide the longest instrumental records of sea-levels with some stretching from the 19th century to present. The derived mean sea-level (MSL) records provide sea-level relative to a nearby tide gauge benchmark (TGBM), which allows for the continuation of this record in time after, for example, equipment modifications. Any changes in the benchmark levels induced by vertical land movements (VLM) affect the MSL records and hence the computed sea-levels. In the past, MSL records affected by VLM were often excluded from further analyses or the VLM were modelled using numerical models of the glacial isostatic adjustment (GIA) process. Over the last two decades Global Navigation Satellite System (GNSS), in particular Global Positioning System (GPS), measurements at or close to tide gauges and the development of the associated processing strategies, have made it possible to obtain estimates of VLM in a geocentric reference system, such as the International Terrestrial Reference Frame release 2008 (ITRF2008) that approach the required accuracy for sea-level studies. Furthermore, the GPS-derived VLM estimates have been shown to improve estimates of sea-level change compared to those using the aforementioned GIA models as these models cannot predict local subsidence or uplift. The International GNSS Service (IGS) Tide Gauge Benchmark Monitoring (TIGA) Working Group has recently re-processed the global GNSS data set from its archive (1000+ stations for 1995-2014) to provide VLM estimates tuned for the sea-level community. To achieve this, five TIGA Analysis Centers (TAC) contributed their reprocessed global GPS network solutions to the WG, all employing the latest bias models and processing strategies in accordance with the second re-processing compaign (repro2) of the IGS. These individual solutions were then combined by the TIGA Combination Center (TCC) to produce, for the first time, a TIGA combined solution (Release 0.99). This combined solution allows an evaluation of each individual TAC solution while also providing a means to gauge the quality and reliability of the combined solution, which is generally regarded as superior to the individual TAC solutions. Using time series analysis methods, estimates of VLM can then be derived from the daily position estimates, which are sub-sequentially employed to investigate coastal sea-levels. In this study, we show results from the evaluation of the relevant solutions, provide an evaluation of the TIGA VLM estimates and give examples of their impact on sea-level estimates for selected tide gauges from around the world. The TAC and TIGA combined solutions, as well as the derived VLM data sets are available from the IGS TIGA WG and will be accessible through SONEL (www.sonel.org) in the near future. [less ▲]

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See detailError-controlled computational fracture mechanics
Bordas, Stéphane UL

Scientific Conference (2017, July 12)

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See detailTours de France
Scuto, Denis UL

Article for general public (2017)

Detailed reference viewed: 5 (1 UL)