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See detailFlexible multibody system modelling: A geometric local frame approach on SE(3)
Sonneville, Valentin ULg

Scientific conference (2015, October 30)

In order to improve computational costs in the frame of flexible multibody system modelling, we propose a geometrically exact framework relying on a local frame description. Thanks to this framework ... [more ▼]

In order to improve computational costs in the frame of flexible multibody system modelling, we propose a geometrically exact framework relying on a local frame description. Thanks to this framework, geometric non-linearities are strongly reduced for two reasons. Firstly, the equations of motion can be solved without introducing a global parametrization of the motion, which also leads to a naturally singularity-free description of large rotations. Secondly, the equations of motion are expressed in a local frame, both at position and rotation level, leading to intrinsic equations. Accordingly, these equations are insensitive to large amplitude motions, such that the geometric non-linearities are naturally filtered. The mathematical developments are carried out in a Lie group setting which, albeit more abstract than classical treatments, provides generic and powerful well established tools. So far, several elements have been formulated in this framework: rigid body, kinematic joints and a flexible beam finite element. A shell finite element and a super-element are also under development. Some interesting numerical advantages are observed following the reduction of geometric non-linearities, e.g., the iteration matrix depends on relative motion within the elements only and is thus invariant under rigid body motions. [less ▲]

Detailed reference viewed: 53 (11 ULg)
See detailL'être-au-monde borderline
Englebert, Jérôme ULg

Scientific conference (2015, October 30)

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See detailBenedetto Varchi, gli artisti e l'accademia a Firenze
Geremicca, Antonio ULg

Scientific conference (2015, October 29)

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See detailInternational Classification of Primary Care in a cross-lingual terminology portal (Poster)
Jamoulle, Marc ULg; Kuehlein, Thomas; Pizzanelli, Miguel et al

Poster (2015, October 23)

ICPC, reflecting the burden of family medicine, is available in the HeTOP cross-lingual terminology portal (URL: www.hetop.eu) in 19 languages, mostly European (e.g. Spanish, Portuguese) but also in ... [more ▼]

ICPC, reflecting the burden of family medicine, is available in the HeTOP cross-lingual terminology portal (URL: www.hetop.eu) in 19 languages, mostly European (e.g. Spanish, Portuguese) but also in Japanese or Mandarin. The HeTOP interface has been also translated in 10 languages by Wonca colleagues (including in Turkish, Vietnamese and Romanian). [less ▲]

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See detailHypercalcémie paranéoplasique et hypercalcémie associée à la Néoplasie Multiple de type I (NEM1): traitement par Cinacalcet
VALDES SOCIN, Hernan Gonzalo ULg; POLUS, Marc ULg

Conference (2015, October 17)

Paraneoplastic hypercalcemia and hypercalcemia associated with neoplastic syndromes are particularly resistant to conventional hypocalcemic treatments. We present and discuss two case reports in which ... [more ▼]

Paraneoplastic hypercalcemia and hypercalcemia associated with neoplastic syndromes are particularly resistant to conventional hypocalcemic treatments. We present and discuss two case reports in which Cinacalcet was used to control hypercalcemia. Paraneoplastic hypercalcemia is present in the first case report, in association with a metastasic neuroendocrine pancreas. In the second case report ,cinacalcet is used to control hypecalcemia in a patient with multiple endocrine neoplasia and hyperparathyroidism not controlled by neck surgery. Cinacalcet is an oral agonist of the Calcium Sensing Receptor. The hypocalcemic effects of Cinacalcet have not been documented so far in hypercalcemia-paraneo plastic linked to cancer of the pancreas (Valdés-Socin & al. Rev Med Switzerland 2009). On the other hand, its use seems promising in the MEN1-associated hyperparathyroidism. (Giusti & al. Endocrine 2015). [less ▲]

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See detailEfficiency of shaft sealing for CO2 sequestration in coal mines
Bertrand, François ULg; Charlier, Robert ULg; Collin, Frédéric ULg et al

in International Workshop on Geomechanics and Energy: The Ground as Energy Source and Storage (2015, October 13)

This work examined the efficiency of a shaft sealing system for the CO2 sequestration in abandoned coal mines. The particular case of the coal mine of Anderlues was considered. The performed simulation ... [more ▼]

This work examined the efficiency of a shaft sealing system for the CO2 sequestration in abandoned coal mines. The particular case of the coal mine of Anderlues was considered. The performed simulation took into account the anisotropic behaviour of shale and the presence of coalbeds. [less ▲]

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See detailLes visages d'Alain Baczynsky
Englebert, Jérôme ULg; Séguin, Marion

Scientific conference (2015, October 10)

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See detailUnderstanding how people with MS get tired while walking
Pierard, Sébastien ULg; Phan-Ba, Rémy; Van Droogenbroeck, Marc ULg

in Multiple Sclerosis Journal (2015, October 09)

BACKGROUND. Walking impairment is frequent, appears early in the disease course of MS patients (MSP), and is perceived as the most disabling symptom. When walking, patients get tired more and differently ... [more ▼]

BACKGROUND. Walking impairment is frequent, appears early in the disease course of MS patients (MSP), and is perceived as the most disabling symptom. When walking, patients get tired more and differently than healthy people (HP) [Phan-Ba et al PLOS 2012]. This limits their walking perimeter. Understanding this phenomenon is thus important to suggest adequate therapies at the right time. OBJECTIVE. Our aim is to understand how MSP get tired while walking compared to HP. Two groups of MSP are considered: those with a low disability level (MSPL) and those with a high one (MSPH). We consider two criteria to measure the disability: the EDSS and the deceleration index (DI) [Phan-Ba et al PLOS 2012]. The limit between the groups is set at DI=0.8 and EDSS=3 (inclusive for MSPL). METHODS. Many gait characteristics (GC) have been measured with the system GAIMS along a 500m path walked as fast as possible. The dataset gathers 464 visits of HP and 70 of MSP. Some people have been assessed several times. There are 33 visits in the group MSPL with the EDSS criterion, and 25 with the DI criterion. Statistical tests (Welch) were performed on the differences and relative differences of the GC measured during the first and last 100m of the test to detect differences between HP and MSPL, and between MSPL and MSPH, as in [ECTRIMS 2012 P755]. RESULTS. Both criteria for defining the groups lead to similar conclusions. For many GC, the distributions of the variations are significantly different between MSPL and MSPH. The largest difference is for the relative difference of speed (p=0.000119 for EDSS and p=0.000021 for DI). In contrast, only the variation of the average lateral distance between the feet, which is related to the size of the base of support (and thus to the balance) shows a very significant difference between HP and MSPL (p=0.000116 for EDSS and p=0.000120 for DI). The balance does not seem to change much from MSPL to MSPH. Besides, we note that the variance decreases slightly from HP to MSPL and increases a lot from MSPL to MSPH. CONCLUSIONS. Statistically, from the motor fatigue point of view, it seems that the course of the MS disease is divided in two different stages. In the first one, MSP get more tired than HP because of a deterioration of the balance. Then, in the second one, their fatigue becomes related to a faster decrease of the walking speed. This suggests that physical therapy exercises focused on the balance could be given to MSP in the early stage of the disease. [less ▲]

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See detailDecrease of carbon tetrachloride (CCl4) over 2004-2013 as inferred from global occultation measurements with ACE-FTS
Mahieu, Emmanuel ULg; Bernath, P. F.; Boone, C. D. et al

Poster (2015, October 05)

In this contribution, we use infrared solar occultation measurements performed by the ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) instrument onboard the SCISAT-1 Canadian ... [more ▼]

In this contribution, we use infrared solar occultation measurements performed by the ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) instrument onboard the SCISAT-1 Canadian satellite (Bernath et al., 2005). Since its launch in August 2003, this spectrometer has been in continuous operation with no significant degradation of its performance, and global measurements are available from late February 2004 onwards, spanning now more than a decade. [less ▲]

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See detailCurrent trend in carbon tetrachloride from several NDACC FTIR stations
Hannigan, J.; Palm, M.; Conway, S. et al

Conference (2015, October 05)

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See detailPhénoménologie de l’électrochoc : Une reprise du cas Jonas
Englebert, Jérôme ULg; Cormann, Grégory ULg

Scientific conference (2015, October 02)

Detailed reference viewed: 33 (3 ULg)
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See detailOuverture des travaux
Valenti, Gianluca ULg; Miesse, Hélène ULg

Conference (2015, October 01)

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See detailA Generic Feature Selection Method for Background Subtraction Using Global Foreground Models
Braham, Marc ULg; Van Droogenbroeck, Marc ULg

in Advanced Concepts for Intelligent Vision Systems (2015, October)

Over the last few years, a wide variety of background subtraction algorithms have been proposed for the detection of moving objects in videos acquired with a static camera. While much effort have been ... [more ▼]

Over the last few years, a wide variety of background subtraction algorithms have been proposed for the detection of moving objects in videos acquired with a static camera. While much effort have been devoted to the development of robust background models, the automatic spatial selection of useful features for representing the background has been neglected. In this paper, we propose a generic and tractable feature selection method. Interesting contributions of this work are the proposal of a selection process coherent with the segmentation process and the exploitation of global foreground models in the selection strategy. Experiments conducted on the ViBe algorithm show that our feature selection technique improves the segmentation results. [less ▲]

Detailed reference viewed: 58 (28 ULg)
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See detailAnalytical model for composite joints under sagging moment
Bennacer, M.A.; Berouai, A; Kriker, A et al

in Engineering Structures (2015), 101

Nowadays, modern codes and standards such as the (Eurocode 4, 2004) deal with the characterisation of steel–concrete composite joints in building structures, mainly under hogging bending moments in the ... [more ▼]

Nowadays, modern codes and standards such as the (Eurocode 4, 2004) deal with the characterisation of steel–concrete composite joints in building structures, mainly under hogging bending moments in the beam. However, in sway composite frames or when the composite structure is subjected to an accidental/exceptional event such as earthquake or column loss, the beam-to-column joint may be subjected to sagging bending moment, a loading situation which is not yet covered by the codes. This paper deals with the behaviour of composite beam-to-column external joints under sagging bending moments, mainly focusing on the specific joint component “concrete slab in compression”. Indeed, if reference is made to Eurocodes, the method recommended to characterise structural joints is the component method and the “concrete slab in compression” component has been identified as the missing component to be able to apply this method to composite joints subjected to sagging bending moment. In this article, the finite element method is used to model the slab using VecTor 2 software. Through the performed numerical simulations, the behaviour of the slab is studied in detail and an analytical model is proposed. With the proposed model, it is possible to characterise the concrete slab in compression component and so, to apply the component method to predict the mechanical properties of composite joints subjected to sagging bending moment. [less ▲]

Detailed reference viewed: 19 (1 ULg)
See detailL’institution de la contre-culture
Saint-Amand, Denis ULg

Conference (2015, October)

Detailed reference viewed: 17 (1 ULg)
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See detailFormer des enseignants soucieux de réduire les inégalités d'apprentissage ou comment tenir le cap entre réponse aux demandes et inertie. Analyse de cas d'un centre de formation d'enseignants en Fédération Wallonie-Bruxelles
Beckers, Jacqueline ULg; Simons, Germain ULg

Conference (2015, October)

Dans cette contribution, nous analyserons l'évolution des enjeux et priorités que s'est progressivement donné le Centre interfacultaire de formation des enseignants (Cifen) de l'Université de Liège depuis ... [more ▼]

Dans cette contribution, nous analyserons l'évolution des enjeux et priorités que s'est progressivement donné le Centre interfacultaire de formation des enseignants (Cifen) de l'Université de Liège depuis sa création officielle en 1995, et nous nous interrogerons sur leur pertinence. Comment prendre la mesure des changements effectivement mis en place, apprécier leur pertinence, réguler leurs effets, éviter l'essoufflement des partenaires du système ? Telles sont quelques unes des questions qui baliseront notre contribution. [less ▲]

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See detailCombining Features for Cover Song Identification
Osmalsky, Julien ULg; Embrechts, Jean-Jacques ULg; Foster, Peter et al

in 16th International Society for Music Information Retrieval Conference (2015, October)

In this paper, we evaluate a set of methods for combining features for cover song identification. We first create multiple classifiers based on global tempo, duration, loudness, beats and chroma average ... [more ▼]

In this paper, we evaluate a set of methods for combining features for cover song identification. We first create multiple classifiers based on global tempo, duration, loudness, beats and chroma average features, training a random forest for each feature. Subsequently, we evaluate standard combination rules for merging these single classifiers into a composite classifier based on global features. We further obtain two higher level classifiers based on chroma features: one based on comparing histograms of quantized chroma features, and a second one based on computing cross-correlations between sequences of chroma features, to account for temporal information. For combining the latter chroma-based classifiers with the composite classifier based on global features, we use standard rank aggregation methods adapted from the information retrieval literature. We evaluate performance with the Second Hand Song dataset, where we quantify performance using multiple statistics. We observe that each combination rule outperforms single methods in terms of the total number of identified queries. Experiments with rank aggregation methods show an increase of up to 23.5 % of the number of identified queries, compared to single classifiers. [less ▲]

Detailed reference viewed: 34 (5 ULg)