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See detailThe European Association for Data Science, its main goals and tasks
Krolak-Schwerdt, Sabine; Böhmer, Matthias UL

Presentation (2016, December)

Detailed reference viewed: 25 (2 UL)
See detailEuropean Conference on Data Analysis 2013. Book of Abstracts.
Lausen, Berthold; Krolak-Schwerdt, Sabine UL; Böhmer, Matthias UL

Book published by University of Luxembourg (2013)

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See detailEvaluating the effects of information reliability on travellers’ route choice
Bifulco, Gennaro N.; Di Pace, Roberta; Viti, Francesco UL

in European Transport Research Review (2013)

Purpose This paper analyses travellers’ behaviour with respect to route choice in a context where an Advanced Traveller Information System (ATIS) is in place. ATIS are important applications in the field ... [more ▼]

Purpose This paper analyses travellers’ behaviour with respect to route choice in a context where an Advanced Traveller Information System (ATIS) is in place. ATIS are important applications in the field of intelligent transportation systems (ITS). However, the practical impact of ATIS is still a matter for debate, and identification of expected route choice behaviour under ATIS is one of themain ways to assess their practical importance. Methods Travellers’ choices are frequently explored by means of stated preference (SP) approaches. In this paper we discuss some issues to be addressed when an SP survey is carried out, with particular reference to cases where a repeated choice approach is employed in the survey. Results Our analysis concerns an application of the SP approach in a pilot study aimed at identifying the effects of ATIS accuracy on travellers’ compliance with information. Conclusions This paper aims tomake two major contributions. First of all, empirical analyses based on proper indicators and statistical tests are suggested in order to evaluate how the collected data have to be handled in order to eliminate transient route-choice observations. These are due to the warm-up phase inherently associated with the survey method adopted, dealing with repeated choices. Secondly, we analyse (stationary) route choice in order to assess the effects of information reliability (and the kind of information) on both route choice and compliance. [less ▲]

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See detailAn evaluation of low-cost consumer-grade UAS systems for 3D reality capture
Backes, Dietmar UL; Teasdale, Oliver; Eloff, Jacques

Poster (2016, September 22)

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled ... [more ▼]

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled by a vibrant community of scientists, professionals and hobby enthusiasts enabling technologies have matured quickly, and prices of consumer grade as well as semi-professional systems fell sharply. Especially multirotor vertical take-off and landing (VTOL) UAS have proven to be versatile and flexible platforms which can be equipped with a range of sensors capable of capturing aerial data for a variety of 2D and 3D mapping applications. Consumer grade, low weight systems as the DJI Phantom or 3DR Solo have a limited payload and can carry low weight action cameras like the GoPro Hero models which are capable of collecting video as well as still RGB and near-infrared imagery. Applying traditional Photogrammetric methods to imagery from low-cost UAS systems proved complex and impractical in the past. However modern the state-of-the-art structure from motion algorithms implemented in off the shelf software packages (sometimes referred as new Photogrammetry), cloud processing environments and available via open source libraries promise to generate dense 3D point clouds, textured models and orthomosaics in high quality and without much effort. How accurate and how reliable are data products generated from such systems? Expanding from a preliminary study (BACKES & TEASDALE 2015) we review the every progressing capabilities and features of COTS (commercial of the shelf) user and semi-professional UAS systems under the aspects of deployable sensors, ease of use, reliability as well as safety. We show the workflow from flight planning, data collection to dense pointclould matching using a range of software products. The resulting point clouds are evaluated and benchmarked using a highly accurate and dense reference data acquired via geodetic terrestrial survey and Laserscanning. The results of this evaluations allow conclusions on the current accuracy capabilities of this such low-cost systems. [less ▲]

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See detailEvaluation of V2me: A Virtual Coaching System for Loneliness Prevention and Intervention
Roelofsma, Peter; Ferring, Dieter UL; Aleksic, Gabrijela UL

in Medicine 2.0: Social Media, Mobile Apps and Internet/Web 2.0 (2013, September)

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive ... [more ▼]

One out of three persons in our society suffers from social or emotional loneliness. This percentage is even higher in the population of people who suffer from chronic diseases. Loneliness has pervasive effects on mental health but it also has negative effects on physical well-being. The aim of this paper is to present a series of pilot studies evaluating the development of an ambient virtual coaching system. This system, called V2me (Virtual Coach reaches Out to Me) offers a friendship enrichment course for people in need for improving their social network. Several pilot studies were performed with about 50 participants in total who evaluated the system that was developed using a living lab approach. In this approach new health media was developed from a user-centered process that allows frequent iterations of user evaluation and involvement. The paper presents the results of the first five iterations. The reactions on receiving the system and experiences during instruction were increasingly positive over these iterations of the system development phase. Over time the system has passed the user’s choice selection criteria. Participants have been expressing a clear interest for choosing and wanting to use the system in their daily lives. However, the system did not pass the persistent use selection criteria when the system was brought and left for independent use. It appeared that participants did not use it very much during the day as expected. Moreover, participants did not perform all the tasks (i.e., messaging, Skyping) that they were asked to achieve on a daily basis. The final goal of the V2me system, i.e. establishing social relations between elderly persons, was not achieved as well, although this might be due to the limited time space of using the system and its facilities. Given these observation, it is concluded that more iterations in the system development are needed for the system in order to pass the habitual use criteria which is needed for its effectiveness. [less ▲]

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See detailEventually everything connects
Lallemand, Carine UL

Speeches/Talks (2018)

If you are reading these lines, you are probably curious about the type of experience that you would have as an attendee of this talk. You might wonder whether the topic would match your interests ... [more ▼]

If you are reading these lines, you are probably curious about the type of experience that you would have as an attendee of this talk. You might wonder whether the topic would match your interests, whether the speaker will be good enough to satisfy your expectations, whether you will feel inspired, exhilarated, or whether you will have concrete tools to bring back to your work. While you are usually the ones shaping people’s experiences, you are striving for nice experiences as well. Designing for human experiences is one of the most challenging yet fascinating activities. It is a responsibility that we should embrace with humility and dedication. To face the complexity of our mission, we need to draw on theoretical knowledge, methodological skills and of course on our shared professional expertise, as a community. While UX practitioners are working hard at the front lines to design better products or services, scientists work in the shadows to develop and consolidate a myriad of novel and highly valuable UX methods. During this talk, you will discover the ever-growing UX toolbox that could greatly support you in collecting richer, insightful and more valid data. From scientific theories to pragmatic methods, from academia to industry, from Luxembourg to Puerto Rico… Eventually everything connects. [less ▲]

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See detailExact and approximate route set generation for resilient partial observability in sensor location problems
Rinaldi, Marco UL; Viti, Francesco UL

in Transportation Research. Part B : Methodological (2017), 105

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a ... [more ▼]

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a methodology to determine sensor locations on a network such that an optimal trade-off solution is found between the amount of sensors installed and the resilience of the sensor set. In particular, we propose exact and heuristic solutions for identifying the optimal route sets such that no other route would include any additional information for finding optimal full and partial observability solutions. This is an important contribution to sensor location problems, as route-based link flow inference problems have non-unique solutions, strongly depending on the used link-route information. The properties of the new methodology are analyzed and illustrated through different case studies, and the advantages of the algorithms are quantified both for full and for partial observability solutions. Due to the route sets found by our approach, we are able to find full observability solutions characterized by a small number of sensors, while yet being efficient also in terms of partial observability. We perform validation tests on both small and real-life sized network instances. © 2017 Elsevier Ltd [less ▲]

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See detailExperimental analysis of eGLOSA and eGLODTA transit control strategies
Giorgione, Giulio UL; Viti, Francesco UL; Rinaldi, Marco UL et al

in Proceedings of the 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems, MT-ITS 2017 (2017)

Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large ... [more ▼]

Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large-scale integration into public transport operations is more complex. This study proposes a novel concept supporting said integration via new control strategies, dubbed e-GLOSA and e-GLODTA. These strategies extend the existing Green Light Optimal Speed and Dwell Time Systems (GLOSA/GLODTA) to account for the specific needs of electric buses. That is, they include the goals of minimizing the energy consumption between charging stations, and maximizing available charging time. At the same time, interference with schedule requirements is minimized. The formulated heuristics are tested on a Bus Rapid Transit (BRT) corridor case study, where different scenarios—such as placement of charging stations and bus regularity—are studied to assess under which conditions each action (maintain speed, accelerate or dwell for a longer time at a stop) is beneficial. Results show that eGLOSA contributes to schedule adherence while eGLODTA allows satisfying charging time constraints. [less ▲]

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See detailExperimental and numerical assessment of the mechanics of keloid-skin composites undergoing large deformations
Sensale, Marco UL; Chambert, Jerome; Chouly, Franz et al

Scientific Conference (2017, August)

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See detailExperimental and Numerical Evaluation of the Residence Time Characteristics on a Forward Acting Grate
Peters, Bernhard UL; Dziugys, A.; Hunsinger, H.

in Condensed Matter 2014 (2014)

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See detailExperimental design trade-offs for gene regulatory network inference: an in silico study of the yeast Saccharomyces cerevisiae cell cycle
Markdahl, Johan UL; Colombo, Nicolo UL; Thunberg, Johan UL et al

in Proceedings of the 56th IEEE Conference on Decision and Control (2017, December)

Time-series of high throughput gene sequencing data intended for gene regulatory network (GRN) inference are often short due to the high costs of sampling cell systems. Moreover, experimentalists lack a ... [more ▼]

Time-series of high throughput gene sequencing data intended for gene regulatory network (GRN) inference are often short due to the high costs of sampling cell systems. Moreover, experimentalists lack a set of quantitative guidelines that prescribe the minimal number of samples required to infer a reliable GRN model. We study the temporal resolution of data vs.quality of GRN inference in order to ultimately overcome this deficit. The evolution of a Markovian jump process model for the Ras/cAMP/PKA pathway of proteins and metabolites in the G1 phase of the Saccharomyces cerevisiae cell cycle is sampled at a number of different rates. For each time-series we infer a linear regression model of the GRN using the LASSO method. The inferred network topology is evaluated in terms of the area under the precision-recall curve (AUPR). By plotting the AUPR against the number of samples, we show that the trade-off has a, roughly speaking, sigmoid shape. An optimal number of samples corresponds to values on the ridge of the sigmoid. [less ▲]

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See detailExperimental validation of a newly designed 6 degrees of freedom scanning laser head: Application to three-dimensional beam structure
Copertaro, Edoardo UL; Di Maio, Dario

in Review of Scientific Instruments (2013), 84

A new scanning laser head is designed to use single Laser Doppler Vibrometer (LDV) for performing measurements up to 6 degrees of freedom (DOF) at a target. The scanning head is supported by a rotating ... [more ▼]

A new scanning laser head is designed to use single Laser Doppler Vibrometer (LDV) for performing measurements up to 6 degrees of freedom (DOF) at a target. The scanning head is supported by a rotating hollow shaft, which allows the laser beam to travel up to the scanning head from an opposite direction where an LDV is set up. The scanning head is made of a set of two mirrors, which deflects the laser beam with an angle so that the rotation of the scanning head produces a conical scan. When measurements are performed at the focal point of the conical scan then three translational vibration components can be measured, otherwise the very small circle scan, before and after the focal point, can measure up to 6 degrees of freedom, including three translations and three rotations. This paper presents the 6DOF scanning head and the measurements of 3D operational deflection shapes of a test structure. [less ▲]

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See detailExplicit finite deformation analysis of isogeometric membranes
Chen, Lei; Nguyen-Thanh, Nhon; Nguyen-Xuan, Hung et al

in Computer Methods in Applied Mechanics & Engineering (2014)

NURBS-based isogeometric analysis was first extended to thin shell/membrane structures which allows for finite membrane stretching as well as large deflection and bending strain. The assumed non-linear ... [more ▼]

NURBS-based isogeometric analysis was first extended to thin shell/membrane structures which allows for finite membrane stretching as well as large deflection and bending strain. The assumed non-linear kinematics employs the Kirchhoff-Love shell theory to describe the mechanical behaviour of thin to ultrathin structures. The displacement fields are interpolated from the displacements of control points only, and no rotational degrees of freedom are used at control points. Due to the high order Ck (k ≥ 1) continuity of NURBS shape functions the Kirchhoff-Love theory can be seamlessly implemented. An explicit time integration scheme is used to compute the transient response of membrane structures to time-domain excitations, and a dynamic relaxation method is employed to obtain steady-state solutions. The versatility and good performance of the present formulation is demonstrated with the aid of a number of test cases, including a square membrane strip under static pressure, the inflation of a spherical shell under internal pressure, the inflation of a square airbag and the inflation of a rubber balloon. The mechanical contribution of the bending stiffness is also evaluated. [less ▲]

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See detailExploiting Resource Heterogeneity in DTN
Sandulescu, Gabriel UL; Schaffer, Peter UL; Nadjm-Tehrani, Simin UL

in Wireless Communications & Mobile Computing (2012), 13(3), 230-243

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See detailExploring the polycentric city with multi-worker households: An agent-based microeconomic model
Lemoy, Rémi UL; Raux, Charles; Jensen, Pablo

in Computers, Environment & Urban Systems (2017), 62

We propose an agent-based dynamics which leads an urban system to the standard equilibrium of the Alonso, Muth, Mills (AMM) framework. Starting for instance from a random initialization, agents move and ... [more ▼]

We propose an agent-based dynamics which leads an urban system to the standard equilibrium of the Alonso, Muth, Mills (AMM) framework. Starting for instance from a random initialization, agents move and bid for land, performing a kind of local search and finally leading the system to equilibrium rent, density and land use. Agreement with continuous analytical results is limited only by the discreteness of simulations. We then study polycentrism in cities with this tool. Two job centers are introduced, and the economic, social and environmental outcomes of various polycentric spatial structures are presented. We also introduce two-worker households whose partners may work in different job centers. When various two-worker households are mixed, polycentrism is desirable, as long as the centers are not too distant from each other. The environmental outcome is also positive, but housing surfaces.increase. (C) 2016 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 95 (5 UL)
See detailExploring the power of converse events
Aucher, Guillaume UL; Herzig, Andreas

in Dynamic Formal Epistemology (2009)

Dynamic epistemic logic as viewed by Baltag, Moss and Solecki (BMS) and propositional dynamic logic (PDL) offer different semantics of events. On the one hand, BMS adds dynamics to epistemic logic by ... [more ▼]

Dynamic epistemic logic as viewed by Baltag, Moss and Solecki (BMS) and propositional dynamic logic (PDL) offer different semantics of events. On the one hand, BMS adds dynamics to epistemic logic by introducing so-called event models as syntactic objects into the language. On the other hand, PDL has instead transition relations between possible worlds. This last approach allows to easily introduce converse events. In this paper we add epistemics to this, and call the resulting logic epistemic dynamic logic (EDL). We show that BMS can be translated into EDL thanks to this use of the converse operator : it enables us to translate the structure of the event model directly within a particular axiomatization of EDL, without having to refer to a particular epistemic event model in the language (as done in BMS).We show that EDL is more expressive and general than BMS and we characterize semantically and syntactically in EDL this embedding of BMS. [less ▲]

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See detailAn extended coordinate descent method for distributed anticipatory network traffic control
Rinaldi, Marco UL; Tampère, C. M. J.

in Transportation Research. Part B : Methodological (2015), 80

Anticipatory optimal network control can be defined as the practice of determining the set of control actions that minimizes a network-wide objective function, so that the consequences of this action are ... [more ▼]

Anticipatory optimal network control can be defined as the practice of determining the set of control actions that minimizes a network-wide objective function, so that the consequences of this action are taken in consideration not only locally, on the propagation of flows, but globally, taking into account the user's routing behavior. Such an objective function is, in general, defined and optimized in a centralized setting, as knowledge regarding the whole network is needed in order to correctly compute it. This is a strong theoretical framework but, in practice, reaching a level of centralization sufficient to achieve said optimality is very challenging. Furthermore, even if centralization was possible, it would exhibit several shortcomings, with concerns such as computational speed (centralized optimization of a huge control set with a highly nonlinear objective function), reliability and communication overhead arising.The main aim of this work is to develop a decomposed heuristic descent algorithm that, demanding the different control entities to share the same information set, attains network-wide optimality through separate control actions. © 2015 Elsevier Ltd. [less ▲]

Detailed reference viewed: 61 (1 UL)