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See detailA new formulation of state estimation in distribution systems including demand and generation states
Rousseaux, Patricia ULg; Toubeau, Jean-François; De Grève, Zacharie et al

in proceeedings of the 2015 Power Tech conference (2015, June)

Distribution system state estimation faces a major difficulty: the lack of real-time measurements. This imposes to add information, usually pseudo-measurements from historical data. This paper proposes a ... [more ▼]

Distribution system state estimation faces a major difficulty: the lack of real-time measurements. This imposes to add information, usually pseudo-measurements from historical data. This paper proposes a different, novel formulation of state estimation relying on the classification of loads into components (e.g. residential, commercial, etc.) and accounting for dispersed generation. The approach “by-passes” the use of pseudo-measurements by expressing the medium-voltage bus injections as functions of a small number of active power components at low-voltage level, treated as additional state variables. The injections at medium-voltage buses become equality constraints. A procedure to identify the above functions is detailed, which takes advantage of data collected by smart meters. [less ▲]

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See detailA dynamic simulation approach to identify additional reactive reserves against long-term voltage instability
Papangelis, Lampros ULg; Panciatici, Patrick; Debry, Marie-Sophie et al

in Proc. of IEEE PES 2015 PowerTech conference (2015, June)

A simple method is proposed to identify additional reactive reserves enabling to counteract long-term voltage instability after a large disturbance. In contrast to the many references based on power flow ... [more ▼]

A simple method is proposed to identify additional reactive reserves enabling to counteract long-term voltage instability after a large disturbance. In contrast to the many references based on power flow calculations, the method resorts to dynamic simulation. The post-disturbance system evolution is simulated in the presence of time-varying shunt susceptances with specified rate of change. This allows to deal with dynamic issues such as the required speed of the additional reactive power sources, or the onset of unstable electromechanical oscillations. Furthermore, a compromise is sought between the speed of action and the volume of additional compensation. The method is demonstrated on a detailed model of the Nordic test system. [less ▲]

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See detailModular modelling of combined AC and DC systems in dynamic simulations
Aristidou, Petros ULg; Papangelis, Lampros ULg; Guillaud, Xavier et al

in Proc. of IEEE PES 2015 PowerTech conference (2015, June)

A formulation is proposed in which an AC-DC system is modeled as a combination of AC grids, DC grids, injectors, AC two-ports and AC/DC converters, respectively. This modular modelling facilitates the ... [more ▼]

A formulation is proposed in which an AC-DC system is modeled as a combination of AC grids, DC grids, injectors, AC two-ports and AC/DC converters, respectively. This modular modelling facilitates the dynamic simulation of future complex AC/DC systems. Furthermore, it can be exploited by the solver, which performs less operations on components with lower dynamic activity, and offers parallel processing of the time simulation. This approach is illustrated on a test system in which a multi-terminal DC grid connects two asynchronous AC systems, allows frequency support between them, and acts as emergency control against AC voltage instability. [less ▲]

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See detailFrom the Guiding Principles on Internal Displacement to the Nansen Initiative: What the Governance of Environmental Migration Can Learn from the Governance of Internal Displacement
Gemenne, François ULg; Brücker, Pauline

in International Journal of Refugee Law (2015), 27(2), 245-263

Environmental migration is often presented as one of the gravest consequences of environmental disruptions – climate change in particular, and is already a reality in many parts of the world. Yet the ... [more ▼]

Environmental migration is often presented as one of the gravest consequences of environmental disruptions – climate change in particular, and is already a reality in many parts of the world. Yet the protection of these migrants is not adequately addressed in the international normative frameworks on migration. As a result, a growing number of scholars and advocacy groups have sought to create a special convention and/or an ad hoc status for these migrants, while others have contended that such a legal status is not the answer. As a result, the protection of environmental migrants is currently the subject of vigorous debates amongst scholars and policy-makers, and no clear solution is yet in sight. Research however has little considered the debates that surrounded the protection of those displaced within their countries (IDPs) in the 1990s. Both phenomena have sometimes overlapped, especially as environmental displacement is often internal. Yet, the debate on IDPs has had some significant success, in particular, the adoption of the Guiding Principles on Internal Displacement in 1998, and the signature of the Organization for African Unity’s Kampala Convention in 2009. This article argues that important lessons can be drawn from the protection of IDPs in order to inform the current debates on the protection of environmental migrants, as the political contexts and policy challenges associated with both crises of the migration regime are often similar. The article identifies such lessons and assesses the opportunities and caveats of applying a similar approach of soft law to environmental migration – and what would be needed to achieve it. [less ▲]

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See detailCrystal structure of arsenuranospathite from Rabejac, Lodève, France
Dal Bo, Fabrice ULg; Hatert, Frédéric ULg; Baijot, Maxime ULg et al

in European Journal of Mineralogy (2015), 27

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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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