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See detailSelf-reported dependence on mobile phones in young adults: A European cross-cultural empirical survey.
Lopez-Fernandez, Olatz; Kuss, Daria J.; Romo, Lucia et al

in Journal of behavioral addictions (in press)

Background and aims Despite many positive benefits, mobile phone use can be associated with harmful and detrimental behaviors. The aim of this study was twofold: to examine (a) cross-cultural patterns of ... [more ▼]

Background and aims Despite many positive benefits, mobile phone use can be associated with harmful and detrimental behaviors. The aim of this study was twofold: to examine (a) cross-cultural patterns of perceived dependence on mobile phones in ten European countries, first, grouped in four different regions (North: Finland and UK; South: Spain and Italy; East: Hungary and Poland; West: France, Belgium, Germany, and Switzerland), and second by country, and (b) how socio-demographics, geographic differences, mobile phone usage patterns, and associated activities predicted this perceived dependence. Methods A sample of 2,775 young adults (aged 18-29 years) were recruited in different European Universities who participated in an online survey. Measures included socio-demographic variables, patterns of mobile phone use, and the dependence subscale of a short version of the Problematic Mobile Phone Use Questionnaire (PMPUQ; Billieux, Van der Linden, & Rochat, 2008). Results The young adults from the Northern and Southern regions reported the heaviest use of mobile phones, whereas perceived dependence was less prevalent in the Eastern region. However, the proportion of highly dependent mobile phone users was more elevated in Belgium, UK, and France. Regression analysis identified several risk factors for increased scores on the PMPUQ dependence subscale, namely using mobile phones daily, being female, engaging in social networking, playing video games, shopping and viewing TV shows through the Internet, chatting and messaging, and using mobile phones for downloading-related activities. Discussion and conclusions Self-reported dependence on mobile phone use is influenced by frequency and specific application usage. [less ▲]

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See detailA New Global Vertical Land Movement Data Set from the TIGA Combined
Hunegnaw, Addisu UL; Teferle, Felix Norman UL; Abraha, Kibrom Ebuy UL

Poster (2017, April 23)

Globally averaged sea level has been estimated from the network of tide gauges installed around the world since the 19th century. These mean sea level (MSL) records provide sea level relative to a nearby ... [more ▼]

Globally averaged sea level has been estimated from the network of tide gauges installed around the world since the 19th century. These mean sea level (MSL) records provide sea level relative to a nearby tide gauge benchmark (TGBM), which allows for the continuation of the instrumental record in time. Any changes in the benchmark levels, induced by vertical land movements (VLM) affect the MSL records and hence sea level estimates. Over the last two decades sea level has also been observed using satellite altimeters. While the satellite observations are globally more homogeneous providing a picture of sea level not confined to coastlines, they require the VLM-corrected MSL records for the bias calibration of instrumental drifts. Without this calibration altimeter instruments from different missions cannot be combined. GPS has made it possible to obtain highly accurate estimates of VLM in a geocentric reference frame for stations at or close to tide gauges. Under the umbrella of the International GNSS Service (IGS), the Tide Gauge Benchmark Monitoring (TIGA) Working Group (WG) has been established to apply the expertise of the GNSS community to solving issues related to the accuracy and reliability of the vertical component to provide estimates of VLM in a well-defined global reference frame. To achieve this objective, five TIGA Analysis Centers (TACs) contributed re-processed global GPS network solutions to TIGA, employing the latest bias models and processing strategies in accordance with the second re-processing campaign (repro2) of the IGS. These solutions include those of the British Isles continuous GNSS Facility – University of Luxembourg consortium (BLT), the German Research Centre for Geosciences (GFZ) Potsdam, the German Geodetic Research Institute (DGF) at the Technical University of Munich, Geoscience Australia (AUT) and the University of La Rochelle (ULR). In this study we present to the sea level community an evaluation of the VLM estimates from the first combined solution from the IGS TIGA WG. The TAC solutions include more than 700 stations and span the common period 1995-2014. The combined solution was computed by the TIGA Combination Centre (TCC) at the University of Luxembourg, which used the Combination and Analysis of Terrestrial Reference Frame (CATREF) software package for this purpose. This first solution forms Release 1.0 and further releases will be made available after further reprocessing campaigns. We evaluate the combined solution internally using the TAC solutions and externally using solutions from the IGS and the ITRF2008. The derived VLM estimates have undergone an initial evaluation and should be considered as the primary TIGA product for the sea level community to correct MSL records for land level changes [less ▲]

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See detailWeinhandel und Weinkonsum in der Stadt Luxemburg im 15. Jahrhundert
Pauly, Michel UL

Conference given outside the academic context (2017)

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See detailSur les représentations galoisiennes des formes modulaires de Hilbert de poids un en caractéristique p
Wiese, Gabor UL

Presentation (2017, April 11)

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids ... [more ▼]

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids un en caractéristique p et de niveau premier à p est non-ramifiée en p. Ce résultat s'applique notamment à des formes qui ne se relèvent pas en caractéristique zéro, et peut être vu comme la précision d'un aspect du poids dans la généralisation de la conjecture de modularité de Serre aux formes de Hilbert. [less ▲]

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See detailEconomic Downturns, Retirement and Long-Term Cognitive Function Among Older Americans
Hessel, Philipp; Riumallo-Herl, Carlos; Leist, Anja UL et al

in Journals of Gerontology Series B : Psychological Sciences & Social Sciences (2017)

Objective: Workers approaching retirement may be particularly vulnerable to economic downturns. This study assesses whether exposure to economic downturns around retirement age leads to poorer cognitive ... [more ▼]

Objective: Workers approaching retirement may be particularly vulnerable to economic downturns. This study assesses whether exposure to economic downturns around retirement age leads to poorer cognitive function in later life. Method: Longitudinal data for 13,577 individuals in the Health and Retirement Study were linked to unemployment rates in state of residence. Random- and fixed-effect models were used to examine whether downturns at 55–64 years of age were associated with cognitive functioning levels and decline at ≥65 years, measured by the Wechsler Adult Intelligence Scale-Revised. Results: Longer exposure to downturns at 55–64 years of age was associated with lower levels of cognitive function at ≥65 years. Compared to individuals experiencing only up to 1 year in a downturn at 55–64 years of age, individuals experiencing two downturns at these ages had 0.09 point (95% Confidence Interval [CI, −0.17, −0.02]) lower cognitive functioning scores at ≥65 years (3 years: b = −0.17, 95%CI [−0.29, −0.06]; 4 years: b = −0.14, 95%CI [−0.25, −0.02]; ≥5 years: b = −0.22, 95%CI [−0.38, −0.06]). Downturns at 55–64 years of age were not associated with rates of cognitive decline. Discussion: Exposure to downturns around retirement is associated with a long-lasting decline in cognitive function in later life. Policies mitigating the impact of downturns on older workers may help to maintain cognitive function in later life. [less ▲]

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See detailAbschlussbericht zum Forschungsprojekt "Bewegter Unterricht in Luxemburg"
Bund, Andreas UL; Scheuer, Claude

Report (2017)

Das Konzept der Bewegten Schule geht auf den Schweizer Pädagogen Urs Illi zurück, der es Mitte der achtziger Jahre vor allem für den Primarbereich entwickelte (Illi, 1995). Ausgehend von einer medizinisch ... [more ▼]

Das Konzept der Bewegten Schule geht auf den Schweizer Pädagogen Urs Illi zurück, der es Mitte der achtziger Jahre vor allem für den Primarbereich entwickelte (Illi, 1995). Ausgehend von einer medizinisch-gesundheitlichen (Bewegung als Gesundheitsressource) und entwick-lungs- und lerntheoretischen (Bewegung als zentrales Element der Kindesentwicklung, Bewe-gung als zusätzlicher Sinnes- und Erfahrungskanal) Begründung, geht es in diesem Konzept grundsätzlich darum, mehr Bewegung in die traditionelle „Sitzschule“ zu bringen. Am Projekt „Bewegter Unterricht in Luxemburg“ nahmen die SchülerInnen und Lehrkräfte der Grundschulen in Angelsberg, Larochette, Nommern, Lintgen und Vichten teil. An den Schulen Angelsberg, Larochette und Nommern fand im Untersuchungszeitraum von September 2014 bis Juni 2016 durchgehend Bewegter Unterricht statt. Diese Schulen werden im Weiteren als „Projektschulen“ bezeichnet. An den Schulen in Lintgen und Vichten wurde nicht „bewegt“ unterrichtet; diese Schulen dienten somit als Kontrollschulen. [less ▲]

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See detailExtending the scale of critical housing studies: Towards ‘cross-border gentrification’?
Christmann, Nathalie UL

Scientific Conference (2017, April)

Drawing upon the case of a polycentric cross-border metropolitan region in western Europe, this paper seeks to explore population mobility and housing market developments at the regional/international ... [more ▼]

Drawing upon the case of a polycentric cross-border metropolitan region in western Europe, this paper seeks to explore population mobility and housing market developments at the regional/international scale. Transnational linkages within this cross-border region intensified with the opening of the borders and the economic development of the Grand Duchy of Luxembourg as a global financial centre and a centre for European Institutions. Today about 44 per cent of employees working in Luxembourg live nearby across the Belgian, French or German border. One of the reasons is that housing prices in Luxembourg are nearly twice those in the neighbouring border regions. This increased mobility has an impact on the residents living in these areas. The research that guides this paper aims to detect perceptions of this phenomenon. Therefore principles of municipal policy, urban planning documents and the local media of three medium sized towns in the borderland are reviewed. Following a rather open research concept based on qualitative approaches (discourse analysis, grounded theory), findings reveal that locational advantages such as the proximity to Luxembourg do play a role; the perception that affordable housing is becoming increasingly critical leads to resentments that mix up with national stereotypes; while city officials report displacement due to the border-effect, they also illustrate the opportunities for regional development; at the same time property developers foster the internationalisation of urban planning. Pointing to the relational geographies that link these different places, the paper discusses the pros and cons of an umbrella concept that might be called ‘cross-border gentrification’. [less ▲]

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See detailSpin texture of two-dimensional topological insulators
Rod, Alexia Nibal UL

Doctoral thesis (2017)

Since the discovery of two-dimensional topological insulators a decade ago, their one-dimensional edge states have attracted significant attention due to their unique properties. For example due to time ... [more ▼]

Since the discovery of two-dimensional topological insulators a decade ago, their one-dimensional edge states have attracted significant attention due to their unique properties. For example due to time-reversal symmetry, they are protected against elastic backscattering and they propagate such that electrons with opposite spins move in opposite directions. In fact, the only necessary symmetry to sustain the edge states is time-reversal symmetry. Moreover in experimental setups, the axial spin symmetry seems to be absent. This absence allows new processes to appear such as inelastic backscattering. However, these consequences were neglected in most theoretical works where the spins are considered to be polarized in the z direction. The aim of this thesis is to provide a more realistic model taking into account a broken axial spin symmetry. In this scheme, we show that a rotation of the spin quantization axis as a function of momentum always appears. This observation leads us to develop a deeper understanding of the size of the rotation related to the material parameters and material models, using also realistic values. It also leads us to understand the implications in real space in cases where translation invariance is lost and how to quantify the rotation in such systems. The new processes which arise when the axial spin symmetry is broken have important consequences for transport in real materials. To see this, we consider a Hall bar with a hole in its middle, i.e. an antidot. This enables us to create two tunneling regions in order to probe the effect of this generic model. We also consider the effect of Coulomb interactions around the hole, as they can be important in such geometry. We discover that it is possible to probe directly the absence of axial spin symmetry. As experimental evidence is important to investigate our theoretical findings, we propose spectroscopic means to probe the spin texture. Finally, we also consider one of the experimentally-known candidate materials, namely InAs/GaSb heterostructures. From the k.p Hamiltonian, it is possible to show that their bandstructure shows some anisotropies. The latter is also reflected in the spin texture of their edge states. [less ▲]

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See detailCross-border evidence gathering: equality of arms within the EU?
van Wijk, Marloes Chantal UL

Doctoral thesis (2017)

The European Union (EU) has set the objective to develop an Area of Freedom, Security and Justice, in which on the one hand freedom of movement is promoted and on the other hand a high level of security ... [more ▼]

The European Union (EU) has set the objective to develop an Area of Freedom, Security and Justice, in which on the one hand freedom of movement is promoted and on the other hand a high level of security is ensured. The EU is therefore adopting measures to enhance international cooperation in criminal matters among the police and judicial authorities of its Member States. The adopted instruments concerning evidentiary matters, such as the gathering, freezing and/or confiscation of information and materials in another EU Member State, seem to serve the main purpose of assisting the authorities in investigating and prosecuting (cross-border) crime. This raises the question to what extent the defence is also given the possibility to gather – or to have gathered – information and materials in another EU Member State with the aim of preparing and presenting its case at trial and, in particular, whether the current (EU) legal framework on cross-border evidence gathering meets the requirements of the principle of equality of arms. This thesis addresses this question by, first of all, discussing the concept of equality of arms, as enshrined in both Article 6 ECHR and Article 47 CFR. It explains to what extent this principle is applicable to cross-border or transnational criminal proceedings and whether it has an autonomous meaning within the EU. In addition, it discusses which requirements can be deduced from the principle in relation to the possibilities of the defence to gather evidence in another EU Member State to prepare and presents its case. Subsequently, the focus is on the development of the European legislation – from both the Council of Europe and the EU – regulating the procedure of cross-border evidence gathering over the last decades. The aim is to explain the position of the defence in this development and to what extent the European legislation gives opportunities to the defence to request the assistance of foreign authorities in obtaining specific information and materials in another EU Member State. In order to understand how the European legislation is applied in practice by the EU Member States, this thesis includes a comparative study of three national jurisdictions: the Netherlands, England and Wales, and Italy. These three jurisdictions each represent a different criminal justice system, either more inquisitorial or adversarial in nature. The comparative study describes how a chosen jurisdiction interprets the principle of equality of arms. Furthermore, it examines to what extent the national jurisdiction allows the defence to carry out independent investigations abroad and how it gives the defence the opportunity to trigger the mechanism of international cooperation and to participate in the requested investigation. Finally, this thesis also includes an analysis of the criminal justice system of the International Criminal Court. In this system evidence gathering depends most of the time on State cooperation and both the Prosecutor and the defence are allowed to conduct independent investigations and seek the assistance of States. It is therefore used as a source of inspiration for potential changes of the EU legislation on cross-border evidence gathering. [less ▲]

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See detailIntegration of the analysis of non-functional properties in Model-Driven Engineering for embedded systems
Brau, Guillaume Sylvain Denis UL

Doctoral thesis (2017)

The engineering of embedded systems relies on two complementary activities: modeling on the one hand enables to represent the system, analysis on the other hand makes it possible to evaluate the various ... [more ▼]

The engineering of embedded systems relies on two complementary activities: modeling on the one hand enables to represent the system, analysis on the other hand makes it possible to evaluate the various non-functional properties (for example, temporal properties with the real-time scheduling analysis). This thesis deals with the integration between these models and analyses: how to apply an analysis on a model? How to manage the analysis process? The first part of this thesis presents a comprehensive approach to answer these questions. This approach is based on four application layers: (1) models to represent the system, (2) accessors to extract data from a model, (3) analyses to compute output data and/or properties from input data (4) contracts to represent the analysis interfaces and orchestrate the analysis process. The second part of this thesis deals with the experimentation of this approach with concrete systems coming from the aerospace: a drone, an exploratory robot and a flight management system. We demonstrate that the accessors enable to apply various real-time scheduling analyses on heterogeneous architectural models, for example written with the industry standard AADL (Architecture Analysis and Design Language) or the new time-triggered language CPAL (Cyber-Physical Action Language). In addition, contracts make it possible to automate complex analysis procedures: which analysis can be applied on a given model? Which are the analyses that meet a given goal? Are there analyses to be combined? Are there interferences between analyses? Etc. [less ▲]

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See detailGranting votes: Exposing the political bias of intergovernmental grants using the within-between specification for panel data
Glaurdic, Josip UL; Vukovic, Vuk

in Public Choice (2017), 171(1-2), 223-241

Instead of alleviating fiscal inequalities, intergovernmental grants are often used to fulfill the grantors’ political goals. This study uses a unique panel dataset on the level of more than 500 Croatian ... [more ▼]

Instead of alleviating fiscal inequalities, intergovernmental grants are often used to fulfill the grantors’ political goals. This study uses a unique panel dataset on the level of more than 500 Croatian municipalities over a twelve-year period to uncover to which extent grant distribution is biased due to grantors’ electoral concerns. Instead of the default fixed effects approach to model panel data, we apply a novel within-between specification aimed at uncovering the contextual source of variation, focusing on the effects of electoral concerns on grant allocation within and between municipalities. We find evidence of a substantial political bias in grant allocation both within and between municipalities, particularly when it comes to local-level electoral concerns. The paper offers researchers a new perspective when tackling the issue of politically-biased grant allocation using panel data, particularly in cases where they wish to uncover the simultaneous impact of time-variant and time-invariant factors, or when they cannot apply a quasi-experimental approach due to specific circumstances of the given institutional context. [less ▲]

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See detailSur les représentations galoisiennes des formes modulaires de Hilbert de poids un en caractéristique p
Wiese, Gabor UL

Presentation (2017, January 19)

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids ... [more ▼]

Dans cet exposé, je vais donner les idées principales de mon travail avec Mladen Dimitrov dans lequel nous démontrons que la représentation galoisienne associée à toute forme modulaire de Hilbert de poids un en caractéristique p et de niveau premier à p est non-ramifiée en p. Ce résultat s'applique notamment à des formes qui ne se relèvent pas en caractéristique zéro, et peut être vu comme la précision d'un aspect du poids dans la généralisation de la conjecture de modularité de Serre aux formes de Hilbert. [less ▲]

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See detailSpin-orbit coupling in quasi-one-dimensional Wigner crystals
Kornich, Viktoriia; Pedder, Christopher UL; Schmidt, Thomas UL

in Physical Review B (2017), 95(4), 045413

We study the effect of Rashba spin-orbit coupling (SOC) on the charge and spin degrees of freedom of a quasi-one-dimensional (quasi-1D) Wigner crystal. As electrons in a quasi-1D Wigner crystal can move ... [more ▼]

We study the effect of Rashba spin-orbit coupling (SOC) on the charge and spin degrees of freedom of a quasi-one-dimensional (quasi-1D) Wigner crystal. As electrons in a quasi-1D Wigner crystal can move in the transverse direction, SOC cannot be gauged away in contrast to the pure 1D case. We show that for weak SOC, a partial gap in the spectrum opens at certain ratios between density of electrons and the inverse Rashba length. We present how the low-energy branch of charge degrees of freedom deviates due to SOC from its usual linear dependence at small wave vectors. In the case of strong SOC, we show that spin sector of a Wigner crystal cannot be described by an isotropic antiferromagnetic Heisenberg Hamiltonian any more, and that instead the ground state of neighboring electrons is mostly a triplet state. We present a new spin sector Hamiltonian and discuss the spectrum of Wigner crystal in this limit. [less ▲]

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See detailLocal Lyapunov Functions for Consensus in Switching Nonlinear Systems
Thunberg, Johan UL; Goncalves, Jorge UL; Xiaoming, Hu

in IEEE Transactions on Automatic Control (2017)

This note presents two theorems on asymptotic state consensus of continuous time nonlinear multi-agent systems. The agents reside in Rm and have switching interconnection topologies. Both the first ... [more ▼]

This note presents two theorems on asymptotic state consensus of continuous time nonlinear multi-agent systems. The agents reside in Rm and have switching interconnection topologies. Both the first theorem, formulated in terms of the states of individual agents, and the second theorem, formulated in terms of the pairwise states for pairs of agents, can be interpreted as variants of Lyapunov’s second method. The two theorems complement each other; the second provides stronger convergence results under weaker graph topology assumptions, whereas the first often can be applied in a wider context in terms of the structure of the right-hand sides of the systems. The second theorem also sheds some new light on well-known results for consensus of nonlinear systems where the right-hand sides of the agents’ dynamics are convex combinations of directions to neighboring agents. For such systems, instead of proving consensus by using the theory of contracting convex sets, a local quadratic Lyapunov function can be used. [less ▲]

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See detailReservoir Computing for Detection of Steady State in Performance Tests of Compressors
Antonelo, Eric Aislan UL; Flesch, Carlos; Filipe, Schmitz

in Arxiv (2017)

Detailed reference viewed: 8 (2 UL)