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See detailReduced Order Model for Accounting for High Frequency Effects in Power Electronic Components
Paquay, Yannick ULg; Geuzaine, Christophe ULg; Hasan, Md. Rokibul et al

Poster (2015, June)

This paper proposes a reduced-order model of power electronic components based on the proper orthogonal decomposition. Starting from a full-wave finite-element model and several snapshots/frequencies, the ... [more ▼]

This paper proposes a reduced-order model of power electronic components based on the proper orthogonal decomposition. Starting from a full-wave finite-element model and several snapshots/frequencies, the reduced-order (RO) model is constructed. Local field values (e.g. magnetic flux density, electric current density, magnetic or electric field) and global quantities (e.g. characteristic complex impedance, joule losses) can be determined for the intermediate frequencies with a very low computational cost and high accuracy. Particular attention is paid to the choice of the most suitable snapshots by means of three different greedy algorithms, the performance of which is compared. We adopt an automatic greedy algorithm that depends only on the RO model. [less ▲]

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See detailNonlinear Interpolation on Manifold of Reduced Order Models in Magnetodynamic Problems
Paquay, Yannick ULg; Bruls, Olivier ULg; Geuzaine, Christophe ULg

Poster (2015, June)

Proper Orthogonal Decomposition (POD) is an efficient model order reduction technique for linear problems in computational sciences, recently gaining popularity in electromagnetics. However, its ... [more ▼]

Proper Orthogonal Decomposition (POD) is an efficient model order reduction technique for linear problems in computational sciences, recently gaining popularity in electromagnetics. However, its efficiency has been shown to considerably degrade for nonlinear problems. In this paper, we propose a reduced order model for nonlinear magnetodynamic problems by combining POD with an interpolation on manifolds, which interpolates the reduced bases to efficiently construct the desired solution. [less ▲]

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See detailAtmospheric pressure mode localization coupled resonators stiffness sensor
Montaseri, Mohammad; Xie, J.B.; Chang, Homglong et al

in Proceedings of Solid-State Sensors, Actuators and Microsystems (Transducers 2015) (2015, June)

This paper reports on a 3-DoF mode localization resonant sensor experimentally evaluated under atmospheric conditions. It was demonstrated that using amplitude ratio as an output signal, even when the ... [more ▼]

This paper reports on a 3-DoF mode localization resonant sensor experimentally evaluated under atmospheric conditions. It was demonstrated that using amplitude ratio as an output signal, even when the device is operated in air, yields a higher sensitivity compared to the frequency variation sensitivity when assuming vacuum conditions. [less ▲]

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See detailA novel resonant accelerometer based on model localization of weakly coupled resonators.
Zhang, Hemin; Yuan, W.Z.; Li, B.Y. et al

in Proceedings of Solid-State Sensors, Actuators and Microsystems (Transducers 2015) (2015, June)

This paper describes a novel MEMS resonant accelerometer based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. It is the first time that this principle is demonstrated ... [more ▼]

This paper describes a novel MEMS resonant accelerometer based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. It is the first time that this principle is demonstrated experimentally for an accelerometer. The measured relative shift in amplitude ratio (~312162 ppm/g) is 302 times higher than the shift in resonance frequency (~1035 ppm/g). [less ▲]

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See detailDo T2-hypointense GH-secreting pituitary adenomas behave differently under somatostatin analogues as primary therapy in acromegaly ?
Potorac, Iulia ULg; PETROSSIANS, Patrick ULg; Daly, Adrian ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

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See detailFrom FIPA to gigantism
Beckers, Albert ULg

Scientific conference (2015, June)

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See detailExtension patterns in pituitary macroadenomas and relation to T2-weighted signal on diagnostic MRI examinations
Potorac, Iulia ULg; Cattin, F; KREUTZ, Julie ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

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See detailFrom FIPA to gigantism
Beckers, Albert ULg; Potorac, Iulia ULg; Rostomyan, Liliya ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

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See detailA novel mutation of the luteinizing hormone/choionic gonadotrophin receptor gene leading to Leydig cell hypoplasia type I
Potorac, Iulia ULg; Rivero-Muller, A; Pintiaux, Axelle ULg et al

in The International Journal of The Romania Society of Endocrinology - Abstract book (2015, June)

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See detailQualité de vie de résidents souffrant de pathologies démentielles issus de 32 MR/MRS de l’asbl FIH
Missotten, Pierre ULg; Schroyen, Sarah ULg; Adam, Stéphane ULg

Report (2015)

Effectuée au niveau de 32 institutions, l’enquête FIH-ULg a permis de récolter des informations par rapport à 1020 résidents et 1412 professionnels. En vue d’évaluer au mieux le niveau de qualité de vie ... [more ▼]

Effectuée au niveau de 32 institutions, l’enquête FIH-ULg a permis de récolter des informations par rapport à 1020 résidents et 1412 professionnels. En vue d’évaluer au mieux le niveau de qualité de vie des résidents (et des facteurs l’influençant), nous avions pris le parti de prendre en considération, dans la mesure du possible, l’avis d’au moins deux professionnels pour un même résident. Ceci nous a permis d’analyser les données à deux niveaux : (1) en privilégiant un score moyen de qualité de vie pour chaque résident (score tenant compte de l’avis des deux ou trois professionnels ayant évalué le niveau de qualité de vie d’un même résident) et (2) en regardant la différence de perception de qualité de vie pouvant exister entre les différents professionnels évaluant un même résident. En vue de mieux comprendre ce qui fait que la qualité de vie n’est pas similaire pour tous les résidents, nous avons mis en lien le niveau de qualité de vie des résidents avec toute une série de facteurs susceptibles de l’influencer, à savoir des facteurs liés (1) au résident lui-même (âge, sexe, diagnostic, niveau de dépendance, etc.), (2) à son contexte de vie (MR ou MRS, unité spécifique ou non, chambre individuelle ou collective, etc.), (3) aux professionnels évaluant la qualité de vie des résidents (âge, sexe, profession, etc., mais aussi vision du vieillissement et des pathologies démentielles) et (4) à la relation existant entre ces professionnels et les résidents (nature, fréquence et qualité des contacts). [less ▲]

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See detailA frequency-domain method for identifying nonlinear vibrating structures
Noël, Jean-Philippe ULg; Dossogne, Tilàn ULg; Kerschen, Gaëtan ULg

Conference (2015, June)

System identification, which refers to the construction of mathematical models from experimental data, plays a key role in the design process of engineering systems. In structural dynamics, the ... [more ▼]

System identification, which refers to the construction of mathematical models from experimental data, plays a key role in the design process of engineering systems. In structural dynamics, the theoretical and experimental aspects of linear system identification have been successfully addressed since the early seventies, and mature analytical, computational and testing tools have emerged. Nonlinear system identification of vibrating structures has also enjoyed significant advances during the past few years. However, the common practice in industry is to ignore nonlinearities, arguably because their analysis is still regarded as impractical. The present work describes a rigorous nonlinear generalisation in the frequency domain of the classical subspace identification algorithms, termed FNSI method. This method is applicable to large-scale systems comprising strong nonlinearities, closely-spaced modes and potentially high, nonproportional damping. Another distinct advantage of the approach is that it offers a convenient way to select an appropriate order for the nonlinear model by means of stabilisation diagrams. The FNSI method is demonstrated in this study using a complete satellite structure with nonsmooth nonlinearities, and a solar panel assembly exhibiting complex nonlinear stiffness and damping mechanisms. [less ▲]

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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 detailA web-based support system of the Belgian Register for Assisted Procreation
Gillain, Nicolas ULg; Bogaerts, Kris; Albert, Adelin ULg et al

Poster (2015, June)

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See detailHistorical evolution of fish biodiversity and capture periodicity in the River Meuse (Belgium) as revealed by 15 consecutive years of fishpass monitoring
Benitez, Jean-Philippe ULg; Dierckx, Arnaud ULg; Nzau Matondo, Billy ULg et al

Conference (2015, June)

In the River Meuse at 323km upstream from the North Sea, the hydroelectric dam of Lixhe (rated power of 5300KW) is equipped with two fishpasses: one pool and weir fishpass (in operation since 1980; 0.13m³ ... [more ▼]

In the River Meuse at 323km upstream from the North Sea, the hydroelectric dam of Lixhe (rated power of 5300KW) is equipped with two fishpasses: one pool and weir fishpass (in operation since 1980; 0.13m³.s-1 operating flow) and one vertical slot fishpass (in operation since 1998; 1m3.s-1 operating flow). Both fishpasses were scientifically monitored using capture traps during 15 consecutive years (from 1999 to 2014). The objective of the study is to analyse i) the evolution of fish stock and biodiversity over 15 years and ii) the capture periodicity of fish and it’s variation over years. During the considered period, we observed 36 species at adult stage (88597 individuals with 75% of cyprinids) and 13 species at juvenile (0+) stage (335067 individuals with 90% of cyprinids). Global results between 1999 and 2014 showed a drastic reduction in capture per year (>90%) for some species like Anguilla Anguilla, Alburnus alburnus, Blicca bjoerkna, Rutilus rutilus and Tinca tinca. Whereas other species have emerged like Aspius aspius and Silurus glanis. For the 0+, an important interannual variation is observed from few individuals to several tens of thousands per year. The comparison between both fishpasses indicated a greater use (>50%) of the vertical slot fishpass by rheophilic species and species that have good swimming ability. The analysis of capture periodicity for the most abundant species at adult stage demonstrated the presence of stable behaviours between years for the Abramis abrama and B. bjoerkna respectively a Q50 of the capture day of the year from 108th to 144th day at mean=17°C and from 118th to 155th day at mean=18°C. In contrast other species have patterns more variables (Barbus barbus: Q50 from 96th to 266th day; R. rutilus: from 10th and 309th day). Finally the 0+ exhibited a capture periodicity stable in time during the summer. [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 detailGroupes délinquants juvéniles, quelle méthode pour une recherche « ethno-criminologique » ? La loi des 4 C
Witvrouw, Line ULg; Glowacz, Fabienne ULg

in Revue Internationale de Criminologie et de Police Technique et Scientifique [= RICPTS] (2015), LXVIII(Avril-Juin), 196-209

La criminologie nous amène à travailler avec des populations difficiles d’accès et requiert une démarche méthodologique structurée et prenant en compte les caractéristiques du milieu de rencontre. A ... [more ▼]

La criminologie nous amène à travailler avec des populations difficiles d’accès et requiert une démarche méthodologique structurée et prenant en compte les caractéristiques du milieu de rencontre. A partir de notre recherche portant sur les groupes de jeunes délinquants ou déviants, une spécificité est apparue dès le début des démarches empiriques. En effet, une notion d’exclusivité est entendue entre chaque membre du groupe, rendant l’accès à l’information difficile tant les frontières de ce groupe vis-à-vis de l’extérieur sont imperméables. Le chercheur se trouve alors confronté à différents obstacles: la difficulté de prise de contacts avec les groupes, la difficulté d’intégration du chercheur au sein de ceux-ci et la difficulté de récolte de données suffisantes pour la recherche. Au vu des constats de terrain, nous avons développé une méthodologie spécifique inspirée de modèles ethnologiques. En prenant en compte les jeunes en tant qu’experts de leur vécu et les intervenants médiateurs d’inclusion sur un terrain, ce processus méthodologique relève d’une co-construction de trois pôles et partenaires et s’apparente à une approche ethno-criminologique. Ce processus par étapes se décline en séquences temporelles successives. Tout d’abord, le positionnement du chercheur comme non-détenteur du savoir, la triangulation de la relation, l’acceptation de la temporalité de la démarche et de l’instrumentalisation de la relation sont autant d’éléments constituant l’étape préalable de ce processus méthodologique. Les étapes suivantes se construisent sur la base de l’évolution du lien entre le chercheur et les jeunes. La loi des 4 C réunit ces étapes, la relation évoluant de la confiance, à la confidence, ensuite à la communication pour aboutir à la coopération [less ▲]

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See detailA shallow-water model with depth-dependent porosity for urban flood modeling
Bruwier, Martin ULg; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

in E-proceedings of the 36th IAHR World Congress (2015, June)

The availability of high-resolution topographic data enables the modeling of urban floods with a high level of accuracy. However, such a modelling has a poor computational efficiency. Subgrid models ... [more ▼]

The availability of high-resolution topographic data enables the modeling of urban floods with a high level of accuracy. However, such a modelling has a poor computational efficiency. Subgrid models enable to decrease the computational time by using coarse cells while preserving information from the detailed topographic data to some degree. In particular, shallow-water models with porosity constitute a subgrid model well-adapted for urban flood modeling. In this article, a new set of fully dynamic shallow-water equations with depth-dependent porosities is presented. Then, the implementation of the model is detailed and preliminary results obtained for a theoretical two-dimensional urban area are analyzed. Unlike recent works, the new model solves the fully dynamic shallow-water equations with depth-dependent and anisotropic porosities, a divergent formulation of the bed slope term, a non-staggered grid with quadrilateral cells and an efficient use of look-up tables to store the porosity relations. [less ▲]

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