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See detailMeasurement of 3D Room Impulse Responses with a Spherical Microphone Array
Embrechts, Jean-Jacques ULg

in Proceedings of the Euronoise 2015 Congress (2015, June)

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications ... [more ▼]

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications, such as the evaluation of spatial room acoustics parameters, the detection of unwanted specular reflections or the 3D auralization of acoustic spaces. A spherical array containing 16 microphones has been realized to measure DRIRs. The logarithmic sinesweep technique is first applied to measure 16 impulse responses, one for each microphone. A spherical harmonics (SH) decomposition of the sound field is then obtained. Spatial aliasing, placement errors and the ‘white noise gain’ (WNG) have been analysed to define the useful bandwith of this measure, i.e. [250Hz – 4kHz]. The coefficients of the SH decomposition are then processed by some beamforming methods, in order to compute the DRIR in any direction around the spherical array. Time and 3D space representations can be generated. The results obtained in some rooms are illustrated in this paper: it is shown that the combination of the ‘delay-and-sum’ and ‘minimum-variance distorsionless response’ beamforming methods is particularly well suited for the analysis of DRIRs. [less ▲]

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See detailDescription of the research project CIMEDE for the industrial construction of evolutionary, sustainable and economic houses
Duthoit, Fabienne ULg; Embrechts, Jean-Jacques ULg

in Proceedings of the Euronoise 2015 Congress (2015, June)

CIMEDE is a research project supported by the Region of Wallonia (Belgium). It stands for CIMEDE “Construction Industrielle de Maisons Evolutives, Durables et Economiques – industrial construction of ... [more ▼]

CIMEDE is a research project supported by the Region of Wallonia (Belgium). It stands for CIMEDE “Construction Industrielle de Maisons Evolutives, Durables et Economiques – industrial construction of evolutionary, sustainable and economic houses”. Since the materials envisaged for this project are timber and gypsum fibre board, it was necessary to design a constructive principle of lightweight timber frame constructions which meets the industrial, sustainable, evolutionary and economic requirements and also the requirements of the Belgian acoustic standard NBN S01-400-1. First of all, an inventory of constructive elements that are currently used in this type of construction (floors, walls and facades) is presented with their acoustic performances. Then, the laboratory measurements of some samples of floors, facades, interior walls and partition walls are described and discussed. On the basis of the measurement results, several solutions that best meet all criteria were retained and a mock-up was built with these constructive elements. Measurement results on this mock-up are also presented. The final solution for the floor, the partition wall, the interior wall and the facade which meets the acoustic requirements is finally described [less ▲]

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See detailOccupational physicians managing workers long-term sickness absence : are they willing to cooperate with family and social insurance physicians ?
Mairiaux, Philippe ULg; Vanmeerbeek, Marc ULg; Schippers, Nathalie ULg et al

Conference (2015, June)

Introduction In Belgium, sickness absence (SA) management implies complementary roles for family (FPs), social insurance (SIPs) and occupational physicians (OPs): FPs deliver sick notes, SIPs control SA ... [more ▼]

Introduction In Belgium, sickness absence (SA) management implies complementary roles for family (FPs), social insurance (SIPs) and occupational physicians (OPs): FPs deliver sick notes, SIPs control SA benefits and OPs strive to adapt work environments to workers’ capacities. In practice however, there is little cooperation between the three physicians. This study aimed at identifying FP-OP-SIP cooperation channels in order to prevent long-term work disability. Methods The study involved two phases. (1) Using the nominal group technique, researchers from the three physician groups reached a consensus on 15 proposals to enhance inter-professional cooperation. (2) A Delphi study was conducted to validate these proposals: 61 experts representing professional groups of physicians (FP, SIP, OP), patients, government, employers and labor unions were asked to participate. A 18-items questionnaire (the 15 proposals + 3 open questions) was used in a 2-round Delphi study. Proposals were accepted if 80% of experts agreed. Results Participation rate was 77% in round 1 and 7 out of the 15 proposals were accepted. During round 2, participation rate was 94%; 2 of the remaining proposals reached agreement level. Public authorities were thus advised to invest in a) promotion of pre-return to work visit with the OP for sick-listed patients; b) a website with OPs contact data; c) joint guidelines for return to work guidance; d) joint training of the 3 physician groups; 5) safe electronic information exchange. Several proposals aiming at giving work-related information to FPs and SIPs did not reach agreement within the OPs expert group. OPs expressed concerns about their own workload and FPs or SIPs ability to understand and use those information. Discussion The need for inter-physician cooperation in disability management may exceed individual goodwill and should best be organised by public authorities. This study may be a first step in this process. [less ▲]

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See detailThe Social (Re)construction of an Incident Reporting System: Opening-up, Closing-down, Starting over
Rossignol, Nicolas ULg

Conference (2015, June)

The literature on incident reporting generally describes Incident Reporting Systems (IRS) as technological tools aiming at improving safety in organizations by initiating a learning process from previous ... [more ▼]

The literature on incident reporting generally describes Incident Reporting Systems (IRS) as technological tools aiming at improving safety in organizations by initiating a learning process from previous events, in order to prevent future incidents and accidents to occur. In this respect, many studies tend to focus on “barriers to reporting” in order to understand why people report (or not) incidents in the dedicated system. Alternatively, we proposed to study IRS as socio-technical artifacts which are embedded in a specific organizational culture and which are interpreted in different ways, illustrating what has been called “interpretive flexibility”. This communication is divided in two parts. First, relying on the Social Construction Of Technology (SCOT) framework, we present the different practices and meanings attributed to the reporting of incidents within the Belgian Nuclear Research Center (SCK•CEN). We link these to the various modes of learning that they enable. By doing so we participate to the opening-up of the research on Incident Reporting to alternative discourses, practices and meanings, unforeseen situations and uncertainties. Second, we present the preliminary results of creative workshops during which we initiated the participatory re-construction of the IRS within the Center, drawing on and extending the results of the “opening-up” phase. By doing so, we aim at contributing to a transparent realization of the reduction of complexity leading to an informed and collective decision on what could/should be the IRS of the Center. In conclusion, we propose a reflexive analysis of this process, and we formulate tentative future research directions. [less ▲]

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See detailLes corps des scientifiques et de l’intellectuel dans la revue La recherche
Dondero, Maria Giulia ULg

in Havelange, Carl (Ed.) La lettre et l'image (2015, June)

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See detailuelle définition du concept de tangente ? Pour quelles raisons ?
Balhan, Kevin ULg; Schneider-Gilot, Marguerite ULg; Krysinska, Marysa

in Repères : Revue des Instituts de Recherche sur l'Enseignement des Mathématiques (2015)

Dans le présent article, nous présentons un parcours didactique visant à faire évoluer chez les élèves le concept de tangente, de leur connaissance antérieure de tangente à un cercle comme droite ne ... [more ▼]

Dans le présent article, nous présentons un parcours didactique visant à faire évoluer chez les élèves le concept de tangente, de leur connaissance antérieure de tangente à un cercle comme droite ne coupant la courbe qu’en un seul point jusqu’à une définition formalisée au sein d’un cours d’analyse. Nous montrons ainsi qu’une définition d’un objet mathématique n’est ni définitive, ni une simple description de l’objet. Le choix d’une définition au détriment d’une autre doit se faire à la lumière d’un projet plus global relatif à l’institution à laquelle elle appartient. [less ▲]

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See detailRegression-based modelling of a fleet of gas turbine engines for performance trending
Borguet, Sébastien ULg; Léonard, Olivier ULg; Dewallef, Pierre ULg

in Proceedings of ASME Turbo Expo 2015 (2015, June)

Module performance analysis is a well-established framework to assess changes in the health condition of the components of the engine gas-path. The primary material of the technique is the so-called ... [more ▼]

Module performance analysis is a well-established framework to assess changes in the health condition of the components of the engine gas-path. The primary material of the technique is the so-called vector of residuals, which are built as the difference between actual measurement taken in the gas-path and values predicted by means of an engine model. Obviously, the quality of the assessment of the engine condition depends strongly on the accuracy of the engine model. The present paper proposes a new approach for data-driven modelling of a fleet of engines of a given type. Such black-box models can be designed by operators such as airlines and thirdparty companies. The fleet-wide modelling process is formulated as a regression problem that provides a dedicated model for each engine in the fleet, while recognising that all engines are of the same type. The methodology is applied to a virtual fleet of engines generated within the ProDiMES environment. The set of models is assessed quantitatively through the coefficient of determination and is further used to perform anomaly detection. [less ▲]

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See detail“Pourquoi écrivez-vous ?” Création et sacralisation
Saint-Amand, Denis ULg

Conference (2015, June)

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See detailThe Pedagogical and Political Roots of Belgian Design
Prina, Daniela ULg

in Simon Thomas, Mienke; Huygens, Frank (Eds.) Design Derby: Netherlands-Belgium (1815-2015), exh.cat. (2015)

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See detailLes leviers de l'inovation pédagogique: contraintes externes vs régulations internes
Scheffers, Patricia ULg

in Scheffers, Patricia (Ed.) Actes du colloque (2015, June)

Depuis les années 60, la fréquence de mutations organisationnelles de l'enseignement supérieur et universitaire en Belgique s'amplifie et adopte même un rythme frénétique ces dix dernières années. Les ... [more ▼]

Depuis les années 60, la fréquence de mutations organisationnelles de l'enseignement supérieur et universitaire en Belgique s'amplifie et adopte même un rythme frénétique ces dix dernières années. Les causes sont tour à tour l'évolution des professions et la volonté politique et/ou économique de restructuration. Deux niveaux de régulations pédagogiques sont amenés à s'articuler. D'une part, celui de l'enseignant acteur-réflexif de son enseignement et d'autre part, des injonctions externes qui réorganise le cadre général. Retour d'expérience sur les innovations en Faculté d'Architecture à Liège. [less ▲]

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See detailInvestigation of Demagnetization in HTS Stacked Tapes Implemented in Electric Machines as a Result of Crossed Magnetic Field
Baghdadi, M.; Ruiz, H. S.; Fagnard, Jean-François ULg et al

in IEEE Transactions on Applied Superconductivity (2015), 25(3), 6602404

This paper investigates the practical effectiveness of employing superconducting stacked tapes to superconducting electric machinery. The use of superconducting bulks in various practical applications has ... [more ▼]

This paper investigates the practical effectiveness of employing superconducting stacked tapes to superconducting electric machinery. The use of superconducting bulks in various practical applications has been addressed extensively in the literature. However, in practice, dramatic decrease in magnetization would occur on superconducting bulks due to the crossed field effect. In our study, we employed the superconducting stacked tapes in a synchronous superconducting motor, which was designed and fabricated in our laboratory, aiming to lessen demagnetization due to crossed field effect in comparison with superconducting bulks. Applying the transverse AC field, the effects of frequency, amplitude, and number of cycles of the transverse magnetic field are discussed. Furthermore, a stack of 16 layers of superconducting tapes is modelled and the consequences of applying the crossed magnetic field on the sample are evaluated. The confrontation between experiments and simulation allows us to thoroughly understand the crossed field effects on stacked tapes. At the end, a preventive treatment, based on the shielding characteristic of superconductor and materials with high permeability, i.e. $mu$-metal and metalic glass, is suggested. On the other hand, the shielding feature of aforementioned materials will hinder the penetration of magnetic field and, consequently, reduction of the demagnetization will be attained. [less ▲]

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See detailSemiótica de la acción: textualización y notación
Dondero, Maria Giulia ULg

in Tópicos del seminario (2015), 31

Our essay focuses on some methodological issues concerning the semiotic analysis of practice. We will initially retrace the debate about the epistemological relationship between text and action, outlining ... [more ▼]

Our essay focuses on some methodological issues concerning the semiotic analysis of practice. We will initially retrace the debate about the epistemological relationship between text and action, outlining the forms of enunciative praxis through different levels of pertinence analysis. Secondly, we propose the concept of ‘textualization’ as a mediation between text and action: textualizations (photographs, videos, notes) organize and represent practices which are in themselves ephemeral and elusive. Finally, we will consider the textual diagrammatization that we call ‘notation’: this analytical form of mediation between text and practice does not have the same status of in-vivo textualisations, but it works like an ex-post reconstruction which highlights the main gestures and exchanges while performing their grammaticalization. A more general aim of this essay is an enquiry into the legitimate objects of textual semiotics: what are the objects that it can analyze without betraying its principle of immanence, but also without being confined to it and, as a consequence, being unable to analyze practices and respond to topical questions on social issues and on the research in the human sciences? [less ▲]

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See detailWhat are the determinants of the operational losses severity distribution ? A multivariate analysis based on a semiparametric approach.
Hambuckers, julien ULg; Heuchenne, Cédric ULg; Lopez, Olivier

Poster (2015, June)

In this paper, we analyse a database of around 41,000 operational losses from the European bank UniCredit. We investigate three kinds of covariates: firm-specific, fi- nancial and macroeconomic covariates ... [more ▼]

In this paper, we analyse a database of around 41,000 operational losses from the European bank UniCredit. We investigate three kinds of covariates: firm-specific, fi- nancial and macroeconomic covariates and we study their relationship with the shape parameter of the severity distribution. To do so, we introduce a semiparametric approach to estimate the shape parameter of the severity distribution, conditionally to large sets of covariates. Relying on a single index assumption to perform a dimension reduction, this approach avoids the curse of dimensionality of pure multivariate nonparametric techniques as well as too restrictive parametric assumptions. We show that taking into account variables measuring the economic well being of the bank could cause the required Operational Value-at-Risk to vary drastically. Especially, high pre-tax ROE, efficiency ratio and stock price are associated with a low shape parameter of the severity distribution, whereas a high market volatility, leverage ratio and unemployment rate are associated with higher tail risks. Finally, we discuss the fact that the considered approach could be an interesting tool to improve the estimation of the parameters in a Loss Distribution Approach and to offer an interesting methodology to study capital requirements variations throughout scenario analyses. [less ▲]

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See detailThe International Journal of Learning in Higher Education
Noiroux, Kevin ULg

in International Journal of Learning in Higher Education (2015), 22

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See detailNumerical study of intrinsic features of isolas in a 2-dof nonlinear system
Detroux, Thibaut ULg; Noël, Jean-Philippe ULg; Masset, Luc ULg et al

in Proceedings of the ICEDyn conference (2015, June)

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the ... [more ▼]

In the present paper, isolated response curves in a nonlinear system consisting of two masses sliding on a horizontal guide are examined. Transverse springs are attached to one mass to provide the nonlinear restoring force, and a harmonic motion of the complete system is imposed by prescribing the displacement of their supports. Numerical simulations are carried out to study the conditions of existence of isolated solutions, their bifurcations, their merging with the main response branch and their basins of attraction. This is achieved using tools including nonlinear normal modes, energy balance, harmonic balance-based continuation and bifurcation tracking, and global analysis. [less ▲]

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See detailA process to address electricity distribution sector challenges: the GREDOR project approach
Cornélusse, Bertrand ULg; Vangulick, David; Glavic, Mevludin ULg et al

in Proceedings of the International Conference on Electricity Distribution, CIRED 2015 (2015, June)

This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution ... [more ▼]

This paper presents a general process set in the GREDOR (French acronym for “Gestion des Réseaux Electriques de Distribution Ouverts aux Renouvelables”) project to address the challenges in distribution systems posed by the integration of renewable generation, changing load patterns, and the changes in the electricity market sector. A use case describing interactions among different players that fits the process is also presented. A pseudo-dynamic approach to Global Capacity Announcement as a way to increase penetration of Renewable Energy Sources in a distribution system is elaborated in more details. [less ▲]

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