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See detailEffect of stress path on the miniaturizatio size effect for nickel polycrystals
Keller, Clement; Hug, Eric; Duchene, Laurent ULg et al

Conference (2015, January 04)

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a ... [more ▼]

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a softening of the mechanical behavior in tension which affects the stress level and the strain hardening. This effect is triggered by the derease of the number of grains across the thickness ( also called thickness"t" over grain size "d" ratio). The objective of this work is to provide new experimental results in order to analyse the miniaturization size effects for various stress paths without strain gradients across the thickness of the samples. To this aim, experimental tensil tests, large tensile tests and shear tests have been performed on Ni sheets ( 0.5mm) with various grain sizes ensuring different t/d ratios. Results show that the miniaturization softening is affected by triaxiality, the larger is this parameter, the lower is the mechanicval softening. These features seem to be linked to surface effects which are larger for low triaxiality stress paths. Attempts of numerical simulations using strain gradient crystal plasticity model are also performed to confirm the role played by surface effects. [less ▲]

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See detailFoucault et Deleuze et Sami-Ali : postmodernité et psychothérapie.
Englebert, Jérôme ULg

Conference (2014, November 22)

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See detailUTILISATION DES RESIDUS DE LAVAGE DES GRANULATS DE CARRIERES DANS L’ELABORATION DE PIECES CERAMIQUES (REGION DE TAMAZOUZT, MAROC).
El Boudour El Idrissi, Hicham ULg; Daoudi, Lahcen; El Ouahabi, Meriam ULg et al

Conference (2014, October 27)

Le site potier de Tamazouzt est situé à 40 km au Sud-Est de la ville de Marrakech. La production est sous forme de poterie décorative d’ustensiles rustiques. La matière première utilisée dans ... [more ▼]

Le site potier de Tamazouzt est situé à 40 km au Sud-Est de la ville de Marrakech. La production est sous forme de poterie décorative d’ustensiles rustiques. La matière première utilisée dans l’élaboration de ces produits est issue de résidus de lavage des carrières de granulats exploités le long des oueds. En plus de la qualité des produits et des rendements élevés, ce site donne un bon exemple de valorisation des résidus de lavage qui causent des problèmes pour l’environnement et pour les industriels. Nous avons caractérisé cette matière première afin d’en faire la promotion et d’encourager l’exploitation de tels matériaux dans le domaine de la céramique à l’échelle globale. Les résultats des analyses montrent que la pâte est constituée de 62% d’argiles, 23% de limons et 15% de sables ; l’indice de plasticité est de l’ordre de 16. Pour 27% d’humidité, le degré de retrait au séchage ne dépasse pas 6%. La minéralogie indique la présence de quartz (32%), plagioclase (20%), feldspaths potassiques (10%), calcite (3%) et argile (31%). Les minéraux argileux sont constitués d’illite (16%), de chlorite (7%), de kaolinite (4%) et de vermiculite (4%). La teneur en matière organique est de 4%. La composition chimique est surtout silico-alumineuse (64% de SiO2, 17% d’Al2O3). Les autres éléments majeurs dont la teneur est significative (> 1%) sont : Fe2O3 (8%), MgO (4%), K2O (3%), CaO (3%), Na2O (2%). Les pièces cuites à 1050°C présentent 2% de retrait, 13% de porosité à l’eau, la résistance mécanique à la compression et à la flexion est respectivement de 63 et 20 Mpa. L’analyse DRX des pièces cuites à 1050°C a montré l’apparition de géhlénite, anorthite, diopside et d’hématite. Ces résultats indiquent qu’en plus de l’utilisation locale dans la poterie décorative ces argiles pourraient être valorisées comme matériaux de construction vue leur caractère isolant (bonne porosité), résistance (bon comportement mécanique) et leur couleur rouge (présence de l’hématite). [less ▲]

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See detailInvestigation of shear stress evolution during neotissue growth in a perfusion bioreactor using 3d multiphysics modeling
Guyot, Yann ULg; Papantoniou, Ioannis; Schrooten, Jan et al

Conference (2014, October)

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See detailInter-professional cooperation between family, occupational and social insurance physicians in managing long-term sickness absence
Mairiaux, Philippe ULg; Vanmeerbeek, Marc ULg; Schippers, Nathalie ULg et al

Conference (2014, September 30)

Background In the Belgian health system, sickness absence (SA) management implies complementary roles for general practitioners (GPs), social insurance physicians (SIPs) and occupational physicians (OPs ... [more ▼]

Background In the Belgian health system, sickness absence (SA) management implies complementary roles for general practitioners (GPs), social insurance physicians (SIPs) and occupational physicians (OPs): GPs deliver sick notes and treatment, SIPs control SA benefits and OPs strive to adapt work environments to workers’ remaining capacities. In practice however, there is little cooperation between the three physicians. In 2009, the Ministry of Employment commissioned a study to identify GP-OP-SIP cooperation channels in order to prevent long-term work disability. Methods The study involved two phases. 1) Researchers from the three groups agreed on 15 proposals to enhance cooperation: to establish a formal contact between GP, SIP and OP for patients with > 3 months SA (n=3) ; SIP decision to end SA benefit to be forwarded to the GP (n=2) ; work-related information to be provided by the OP to GP and/or SIP (n=4); website giving contact data of GPs, SIPs, and OPs (n=2) ; initial and continuous education focusing on inter-physician cooperation (n=3); electronic data exchange when dealing with long-term SA (n=1). 2) A Delphi study was conducted in 2012 to validate these proposals: 61 experts representing professional groups of physicians (GP, SIP, OP), patients, government, employers and labor unions were asked to participate. A 18-items questionnaire (the 15 proposals and 3 open questions) was used in a 2-round Delphi study. Proposals were accepted if 80% of experts agreed. For drafting the final proposals, the research team relied on a multidisciplinary expert group. Results Participation rate was 77% (47/61 experts) in round 1 and 7 out of the 15 proposals were accepted. During round 2, participation rate was 94% (44/47); 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) methods ensuring safe electronic information exchange. Conclusions The need for inter-physician cooperation in disability management may exceed individual goodwill and should best be organised by public authorities. The current study may be a first step in this process. [less ▲]

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See detailDevant le forum de la perception interne. Sur les objets d’ordre supérieur III
Zincq, Aurélien ULg

Conference (2014, September 25)

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See detailObjets réels et objets idéaux. Sur les objets d’ordre supérieur II
Zincq, Aurélien ULg

Conference (2014, September 23)

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See detailComplexions et relations. Sur les objets d’ordre supérieur I
Zincq, Aurélien ULg

Conference (2014, September 22)

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See detailLes effets de la retraite sur la mémoire
Adam, Stéphane ULg

Conference (2014, September 16)

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See detailRANS and Large Eddy Simulation of the hydrodynamics inside mini-bioreactors designed for stem cell culture
Collignon, Marie-Laure ULg; Martin, Céline; Blanchard, Fabrice et al

Conference (2014, September 07)

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See detailCost monitoring to promote the value added for clam raising farmers in the Northern area of Vietnam
Bui Thi, Nga; Tran Thu, Hoai; Tran Huu, Cuong et al

Conference (2014, September 02)

Clam farming in coastal provinces of Vietnam has notably developed since the last decade. It generated high income, improve socio-economic development for many local communities. However, many clam ... [more ▼]

Clam farming in coastal provinces of Vietnam has notably developed since the last decade. It generated high income, improve socio-economic development for many local communities. However, many clam raising farms are facing difficulties of farm management, disease control, markets and systems of quality control. This research aims to study about the real situation of cost monitoring in the clam raising farms in the Northern area of Vietnam and suggest some recommendation for apply a suitable model for cost monitoring to promote the value added for farmers. The paper based on the semi-structure, standard questionnaires and PRA method to collect data from 89 clam raising farms in two coastal provinces (Nam Dinh and Thai Binh) in the Northern area of Vietnam in 2014. The findings show that clam raising provides farmers a chance of getting high income parallel with high risk. There were 32.15% surveyed farms got profit, 32.14% of them met the breakeven and 35.71% was lost. The study finds out four key factors affecting farms’ economic performance and efficiency. The first is capacity of farm cost control as the cost for clam raising was very high at 8,142 to 9,190 USD per ha. The second is the farmers’ experience, skill, technique and ability of risk control. The third is low, unstable market price and unsuitable market channel with the dominant of the traders. Final factors is the area and location of clam raising. Despite of these difficulties, 55.14% surveyed farms still want to expand their production, 25% of them will continue, and only 17.86% will stop or change to other activities. In order to promote the value added for clam raising farmers, cost control should be paid more attention, improvement of the farmers’ capacity is necessary, and market should be regarded. [less ▲]

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See detailSelecting job candidates who have a propensity to exhibit change-oriented organizational citizenship behaviour.
Lothe, Benoit ULg; Hansez, Isabelle ULg

Conference (2014, September)

Purpose An abundant literature indicates that Organizational Citizenship Behaviours (OCBs) positively influence a number of important organizational outcomes. Furthermore, research is needed on the topic ... [more ▼]

Purpose An abundant literature indicates that Organizational Citizenship Behaviours (OCBs) positively influence a number of important organizational outcomes. Furthermore, research is needed on the topic of assessing and selecting applicants who have a propensity to exhibit OCB (Organ & al., 2010). Some of these behaviours are truly important to enable organization to adapt and “to make constructive changes in the work and task environment” (Choi, 2007, p.468). Examples include Voice, a challenging dimension of OCB (Dominguez & al., 2013), and Sportsmanship, that facilitate the change by reducing the diversion of resources in trivial matters (Organ & al., 2006). This exploratory study provides empirical evidence about using Situational Judgment Tests (SJTs) for identifying applicants who have a propensity to exhibit change oriented OCB. Method Two SJTs were developed to comply with OCBs assessment. The OCBs framework includes behaviours relating to organizational adaptation (sportsmanship) and change (voice). OCBs were concurrently collected using self-reported measurement scales. Data were collected from 220 white collars and 139 university students through an online survey. Results Significant correlations were found between the SJT scores and overall OCB ratings. More specifics findings provided substantial evidence for the concurrent validity of the SJTs to measure change-oriented sub-dimensions of OCBs. Conclusions Researches on techniques to predict OCBs are scarce and this study is the first to address the development and validation of a SJT for the assessment of affiliative and challenging dimensions of OCBs. [less ▲]

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See detailThe Double-Sarcophagus of Hierapytna (Creta). A Reassessment
Veymiers, Richard ULg

Conference (2014, September)

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See detailA Multiphysics model of neotissue growth in a perfu sion bioreactor
Guyot, Yann ULg; Papantoniou, Ioannis; Schrooten, Jan et al

Conference (2014, September)

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See detailFormal Incident Reporting System: Putting Solidarity on Trial
Rossignol, Nicolas ULg; Claisse, Frédéric ULg

Conference (2014, September)

The practice of “incident reporting” is commonly recognized as an effective mean to reduce the vulnerability of “at risk” socio-technical systems (e.g. nuclear plants, large industrial facilities or ... [more ▼]

The practice of “incident reporting” is commonly recognized as an effective mean to reduce the vulnerability of “at risk” socio-technical systems (e.g. nuclear plants, large industrial facilities or hospitals), as it allow the concerned community to learn from past incidents. Indeed, it is assumed that collective resilience will be upgraded via the use of institutionalized Incident Reporting System (IRS), enabling the organization to improve the quality of the actions and reactions in case of deviation from normality, or to prevent such deviation. Yet, inductive analysis of what happens with those IRS in practice are not numerous. In this paper, we address this gap and display the results of semi-structured interviews conducted in a nuclear facility. During those interviews, participants were also requested to produce a mind map of the IRS they are concerned with. As a result, we show that safety is a matter of solidarities that are situated in specific contexts. To that regard, incident reporting is a practice of decomposition and recomposition of trusts and thus of solidarities. Reporting incidents consists in putting solidarity on trial, as the collective safety was threatened. We show that such open trial is often avoided because questioning solidarities is not always desirable in order to allow the group to continue functioning. Overall, we argue that informal reporting behaviors can also contribute to upgrade collective resilience without putting solidarities on trial. [less ▲]

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See detailIncreasing the efficiency of Organic Rankine Cycle Technology by means of Multivariable Predictive Control
Hernandez Naranjo, Jairo Andrés ULg; Desideri, Adriano ULg; Ionescu, Clara et al

Conference (2014, August 25)

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear ... [more ▼]

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear multiple-input multiple-output (MIMO) process, conventional control strategies (e.g. PID) may not achieve satisfactory results. In this contribution our focus is on the accurate regulation of the superheating, in order to increase the e fficiency of the cycle and to avoid the formation of liquid droplets that could damage the expander. To this end, a multivariable Model Predictive Control (MPC) strategy is proposed, its performance is compared to the one of PI controllers for the case of variable waste-heat source profi les. [less ▲]

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See detailExperimental study of the drying kinetic of mortar
Kahlerras, Loubna ULg

Conference (2014, August 24)

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement ... [more ▼]

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement pastes during thermal drying. Three types of cement pastes were realized and studied; cement pastes with ratios W/C 0.4, W/C 0.5 and mortar with ratio W/C 0.5. These tries present the advantage to reproduce the natural conditions met in the problems of interaction atmosphere and material. Cylindrical samples of cement of size (17 X 13) mm are dried in a convective dryer. The sample is continuously weighed during the drying test and its mass is recorded every 60 s, in the purpose to obtain the drying curves. The results show that the increase of the W/C ratio leads to an increase of the drying rate due to the increase of the initial porosity. The effect of the introduction of aggregates is observable by the comparison of the drying curve obtained for the mortar and the cement pastes. The results show a decrease of the drying kinetics with mortars. The results also show that the air drying temperature has a large impact on the drying process, increasing the temperature leading to significant drying time reduction. The Effective diffusion coefficient is calculated by comparison between the experimental results and the analytical solution of Fick’s equation written for a finite medium. [less ▲]

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See detailmodelling heat and mass transfer during convective drying of a building material
Kahlerras, Loubna ULg

Conference (2014, August 24)

The purpose of this study is to characterize experimentally the behaviour of a cement mortar during its convective drying. The work presented here focuses on mortars with water-to cement ratios (w/C) of 0 ... [more ▼]

The purpose of this study is to characterize experimentally the behaviour of a cement mortar during its convective drying. The work presented here focuses on mortars with water-to cement ratios (w/C) of 0, 5. The drying tests are realized in a convective dryer designed for the drying of small samples (0 - 8g). Experiences are realized with different conditions of drying air temperature (60, 90 and 130 °C) and velocity (2, 3 and 5 m/s) the results show the influence of temperature and velocity on drying curve. Mathematical models have been used for the description of drying curves. The exponential mathematical model seems the most adequate to describe the drying curves of cement mortars, with correlation coefficients changing with the air temperature and velocity and close to unity. The convective mass and heat transfer coefficients are determined from the experimental data. The results showed that both mass and heat transfer coefficients were affected by the air temperature and velocity. The convective mass transfer coefficient changed from 0.0232m/s at V=2m/s to 0.045m/s at V=5m/s, and from 0.055 m/s at 60°c to 0.023 at 130°c. Heat transfer coefficient changed from 14.767 w/m2°c at V=2m/s to 28.64 w/m2°c at V=5m/s and from 7.71 at 60° c to 14.77 at 130°c The temperature dependency of the two coefficients was expressed using an Arrhenius-type equation and related parameters were deduced [less ▲]

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See detailThe taste bud and the form. Ethnography of sensory labs
Vangeebergen, Thomas ULg

Conference (2014, August 22)

Sensory analyses present an opportunity to challenge classical dualism, especially when it is about taste. During long-term fieldworks, I accompanied several types of sensory expert panels, which had the ... [more ▼]

Sensory analyses present an opportunity to challenge classical dualism, especially when it is about taste. During long-term fieldworks, I accompanied several types of sensory expert panels, which had the mission to discriminate different sorts of products and define their respective sensory profile. I was interested to observe the period of training to understand how those people had acquired their expertise, and how their attention toward their own sensations were entangled to scientific infrastructures. Using sensory ethnographic methods, I assisted to the emergence of a particular world, in which the classical categories for science practices and taste perception were completely blurred. To establish a common truth, through sturdy and stable categories, appears to be compatible with personal moods and dispositions, singular and hedonic judgments, sociocultural grounded sensorium, contingent elements, and indeterminate parameters. Resorting to standard tests, educated and coached judges, statistical treatments, specific vocabulary, comparisons to physic-chemical analysis and various other apparatuses, these labs tempt to define and assess some food products. The goal of those examinations could be multiple: to outline consumers¿ feelings and choices, to check the quality of production, to search new applications, or to improve a current array. What interested me is the quest to an object practically exploitable in an industrial and commercial context, avoiding all kind of idiosyncratic experiences. In this presentation, I would tempt an analysis of those particular tests, focusing on the double bind of testing products and testing consumers, and searching to assess the causes of organoleptic variability. [less ▲]

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See detailVirus indexing and sanitation of international banana collection: insights from a 5-year collaborative effort
De Clerck, Caroline ULg; Parmenter, Kathleen; Vandenhouwe, Ines et al

Conference (2014, August 14)

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See detailThe role of segmentation and investor recognition through the lens of cross-listing activity
Mouchette, Xavier ULg; Muller, Aline ULg; Carrieri, Francesca

Conference (2014, August)

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See detailDiplomacia pública, ¿de la teoría a la práctica?: El caso de la Unión Europea en Brasil
Azpíroz Manero, María Luisa ULg

Conference (2014, August)

El entusiasmo académico por la diplomacia pública no se refleja en una atención específica a la misma en las estrategias de política exterior de la Unión Europea (UE). Sin embargo, su presencia se revela ... [more ▼]

El entusiasmo académico por la diplomacia pública no se refleja en una atención específica a la misma en las estrategias de política exterior de la Unión Europea (UE). Sin embargo, su presencia se revela en múltiples iniciativas en las que los agentes no gubernamentales tienen un papel clave como receptores o actores: actividades de cooperación, de intercambio, informativas. La diplomacia pública es una actividad diplomática y de comunicación política internacional que busca influenciar a públicos extranjeros con el fin de contribuir al logro de objetivos de política exterior y/o generar una imagen positiva. Funciona como una herramienta efectiva para movilizar recursos de poder blando, un poder basado en la atracción y la persuasión que se produce de modo indirecto cuando los actores políticos movilizan recursos como la cultura, los valores, las instituciones y las estrategias de política exterior. Pese a la crisis económica, la UE conserva un gran potencial de poder blando. Por eso, y dada la relevancia de Brasil como socio prioritario en la región latinoamericana, este artículo investiga qué diplomacia pública ha desarrollado la UE en este país los últimos tres años, así como su correspondencia con el cuerpo teórico sobre esta actividad. [less ▲]

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See detailDeveloping situational judgment tests to assess organizational citizenship behaviours
Lothe, Benoit ULg; Hansez, Isabelle ULg

Conference (2014, August)

a) Purpose As Organizational Citizenship Behaviours (OCBs) positively influence a number of important outcomes (e.g. job performance, unit productivity, organizational efficiency, etc.) and are valued by ... [more ▼]

a) Purpose As Organizational Citizenship Behaviours (OCBs) positively influence a number of important outcomes (e.g. job performance, unit productivity, organizational efficiency, etc.) and are valued by managers as well, Organ, Podsakoff and Podsakoff (2010) assert the need “to try to identify and select those job candidates who have a propensity to exhibit these behaviours” (p.314). This study provides some empirical evidence about using Situational Judgment Tests (SJTs) for this specific target and allows us to discuss the main methodological issues in the development of such SJTs. b) Method Based on relevant best practices and recommendations from the literature (e.g. Weekley, Ployhart & Holtz, 2006), two distinct SJTs were especially developed to comply with OCBs assessment. The two SJTs differ on their job specificity degree (project manager in the industrial sector vs transversal function in the services sector), both propose ten different work related situations and, for each stem, five action proposals are available. Data were collected through online survey on two different samples (220 white collars professionals and 291 university students). Professionals were allowed to choose which SJT they wanted to participate, students were randomized within the two SJTS. An experimental manipulation of the response instructions (ipsative vs normative) was added within the student sample. OCBs were concurrently collected using self-reported measurement scales. c) Results In both samples (respectively professionals and students), the internal consistency was higher for the “job specific” SJT (α = .79 & .81) than for the “transversal job” SJT (α = .49 & 64). Notwithstanding, significant relations were found between the SJT scores and overall OCB ratings for both of the SJT forms in each of the two samples (r ranged from .30 to .57). Other specifics findings also provided substantial evidence for the concurrent validity of the SJTs to measure sub-dimensions of OCBs (altruism, courtesy, civic virtue, sportsmanship, loyalty and voice). d) Conclusions This study is, to our knowledge, the first to address the development and validation of a SJT for the assessment of OCBs. Review of the literature indicates that researches on techniques to predict OCBs are scarce and the present findings appear to surpass the average personality traits validity coefficients (r= .20) according to Organ & al. (2010)’s meta-analysis. There are two main practical implications. The first is the opportunity to use OCBs-SJTs as an alternative to assess applicants OCBs for job-specific or generic personnel selection issue. The second is to provide methodological development advices (e.g. the choice of response instruction) to ensure the SJT match the OCBs assessment requirement. Principal current limitations call for further research development that will be discussed: using different sources of OCBs rating, testing the incremental validity on personality tests, determining whether OCBs-SJTs are correlated with cognitive ability and establishing criterion validity with job performance. [less ▲]

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See detailComparison of patient's voice quality for T1A glottis carcinoma after endoscopic laser surgery or radiotherapy
Poncelet, Mélanie; DEMEZ, Pierre ULg; Moreau, Pierre ULg et al

Conference (2014, July 30)

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See detailStreamable Laguerre-Voronoi Tessellation Model for Tomographic Images
Leblanc, Christophe ULg; Nguyen, Van Dung ULg; Wan, Fangyi et al

Conference (2014, July 25)

Introduction. Nowadays, the interest in foam materials is growing in several engineering fields [1]. Foams can exhibit a nonlinear mechanical behavior [2], which is highly depen- dent on their ... [more ▼]

Introduction. Nowadays, the interest in foam materials is growing in several engineering fields [1]. Foams can exhibit a nonlinear mechanical behavior [2], which is highly depen- dent on their microstructure [3]. Thus designing foams with specific mechanical properties can be very challenging. The present contribution is part of the ARC-Bridging project [4], whose objective is to predict the mechanical behavior of complex microstructured mate- rials via numerical simulations. A possible classification of foam models into two groups is: random models and deterministic models [5]. The random models frequently require statistical estimations of their parameters [6], whereas the deterministic models generally require numerically expensive image analyse. Indeed, classical analysis steps involve a distance tranform, a watershed and, optionally, a h-minima transform [5, p. 22], which can be computationally demanding [7, 8, 9]. Contribution. In the present Laguerre–Voronoi tessellation model, the image analysis part neither involes the watershed transform, nor the h-minima transform. Instead, fol- lowing the original idea of A.M. Lopez-Reina et E. Béchet [10], these two transforms are respectively replaced by a Hessian-based removal of spurious extrema and a clustering of the remaining maxima. This substitution allows the processing of large 3D-images by slices, i.e. “streaming”. The only limitation is enforced by the distance transform: the “feature” voxel of a given voxel should belong to the same slice. For foam images, this condition is fulfilled as long as the slice’s thickness is larger than the maximal foam cell’s size. Conclusion and perspectives. The aim of this contribution is to provide an efficient tessellation model for tomographic images of foams. From input tomographic images, this model provides a geometry model which will be used as an input for finite element simulations under the ARC-Briding project [4]. Simulation results will be compared with experimental measures. [less ▲]

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See detailBrokers and intermediaries in environmental governance, Southern Sri Lanka
Rosillon, Caroline ULg

Conference (2014, July 23)

Since the end of the civil war in 2009, rural Southern Sri Lanka is facing growing tensions between fast economic development and the conservation of biodiversity, which contributes to the notoriety of ... [more ▼]

Since the end of the civil war in 2009, rural Southern Sri Lanka is facing growing tensions between fast economic development and the conservation of biodiversity, which contributes to the notoriety of the island. In order to preserve the green areas of the country, both the government and international institutions have made great efforts to implement projects combining biodiversity protection and poverty reduction as their objectives. Within that context, this paper focuses on a specific category of stakeholders, emerging from the implementation of the aforementioned projects: a wide range of intermediaries between local communities and the State, or international institutions. Based on an ethnographic study of two protected areas in Southern Sri Lanka, the paper will examine the role of those intermediaries in the implementation of environmental governance models and ideologies in local arenas. I will also analyze the complex relationships between those brokers and other categories of individuals or groups within the community: people living in protected areas, traditional figures of power, social and political elites, etc. Using fieldwork illustrations, I will stress how the emergence of brokers and intermediaries in the context of nature conservation may lead to the reorganization of social and political relationships at the local scale. [less ▲]

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See detailDetection of differential item functioning using the lasso approach
Magis, David ULg; Tuerlinckx, Francis; De Boeck, Paul

Conference (2014, July 22)

The purpose of this talk is to present a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis ... [more ▼]

The purpose of this talk is to present a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis, we consider a logistic regression model including item-group interaction (i.e. DIF) effects of all items simultaneously. The method is based on penalized maximum likelihood estimation of a model with a lasso penalty on all possible DIF parameters. Optimal penalty parameter selection is investigated through several known information criteria (such as AIC and BIC) as well as a newly developed weighted alternative. A simulation study was conducted to compare the global performance of the suggested “lasso DIF” method to the logistic regression and Mantel-Haenszel methods, and to evaluate the different optimal penalty parameter selection methods. It is concluded that for small samples the lasso DIF approach globally outperforms the logistic regression method, and also the Mantel-Haenszel method, especially in the presence of item impact, while it yields similar results with larger samples. [less ▲]

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See detailNumerical modelling of mirror nozzle flow
De Cock, Nicolas ULg; Massinon, Mathieu ULg; Mercatoris, Benoît ULg et al

Conference (2014, July 15)

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See detailHigher Symmetries of the conformal Laplacian
Radoux, Fabian ULg

Conference (2014, July 14)

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See detailStudy of the specific interaction between Fluorescent PDMAEMA and human Platelets
Flebus, Luca ULg; Lombart, François ULg; Martinez, Lucia et al

Conference (2014, July 12)

Hemoreactivity of the poly (2-(dimethylamino) ethylmethacrylate) polymer (PDMAEMA) under a free form (thus not as a “PolyElectrolyte Complex”) was assessed. In order to facilitate the in vitro monitoring ... [more ▼]

Hemoreactivity of the poly (2-(dimethylamino) ethylmethacrylate) polymer (PDMAEMA) under a free form (thus not as a “PolyElectrolyte Complex”) was assessed. In order to facilitate the in vitro monitoring of this polycation and especially to follow its reactivity blood we have labeled it with fluorescein adopting a new chemical route of synthesis. Unexpectedly, using flow cytometry, this study showed a higher affinity of PDMAEMA for platelets than for red blood cells. [less ▲]

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See detailLiterature through Technology. Depicting the Future of the Book from Verne to Barjavel
Stienon, Valérie ULg

Conference (2014, July 10)

French futuristic novels tend to develop a wide range of representations regarding the book of the future as it is impacted by technical inventions, from the phone to the digital paradigm through ... [more ▼]

French futuristic novels tend to develop a wide range of representations regarding the book of the future as it is impacted by technical inventions, from the phone to the digital paradigm through photography and film: Albert Robida’s “phono-livre” (La Vie électrique, 1890), Octave Uzanne’s “storyographe” powered by electricity from the human body, Henri Allorge’s “bibliophone” (Le grand cataclysme, 1922), Léon Daudet’s “cinébiblat” and “cinélivre” (Le Napus, 1927), Maurice Renard’s telepathic book (Un homme chez les microbes, 1928) or even René Barjavel’s “télélecture” (Ravage, 1943) among others. It is well known that the historical antagonism between Science and the Humanities deeply influenced the disciplinary boundaries and the respective values of the two fields. But it also appears that such a disciplinary discussion does involve the issue of the material and tangible forms of the book considered as an object. Futuristic novels put a specific emphasis on the acoustic, visual and tactile avatars of the book within a sociocultural context characterized by the rise of Applied Sciences and media communication. Do these new media and formats compete with or complement to the former book patterns? Are such representations of the book as an audiovisual item some response to the predicted decline of the Humanities? Or are they rather a means of asserting the faith in a new forthcoming kind of literature? Although science may badly affect literature so as to produce an impoverishing mechanization of literary style (Jules Verne, Paris au XXe siècle, 1863), it also gives a valuable opportunity to create more ergonomic formats for a wider distribution and a more easily handheld book. Since the late 19th century until WWII, many futuristic novels propose to consider the book as it is located at the junction of Science and the Humanities rather than in their dichotomous opposition. Regarded as a specific leitmotiv, such a topic of technological and transmedia conversions of the book leads to reconsider the evolution of the identity paradigm of France as a “literary nation”. It also gives the opportunity to investigate the discrepancies and coincidences between the conjectural scope of these futuristic novels and the factual history of technological advances. [less ▲]

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See detailOutils d’étude pour caractériser l’impact de l’ hydrodynamique sur la culture de cellules animales adhérentes cultivées sur microporteurs en bioréacteurs à cuve agitée
Collignon, Marie-Laure ULg

Conference (2014, July 10)

Cette présentation montre l'importance du choix des conditions d'agitation lors de la culture de cellules animales adhérentes sur microporteurs en bioréacteurs à cuve agitée. Elle montre des exemples d ... [more ▼]

Cette présentation montre l'importance du choix des conditions d'agitation lors de la culture de cellules animales adhérentes sur microporteurs en bioréacteurs à cuve agitée. Elle montre des exemples d'outils pour caractériser à l'échelle locale l'hydrodynamique au sein de ces bioréacteurs et une approche Euler-Lagrange qui a terme permettra de faire le lien entre l'hydrodynamique et la réponse cellulaire grâce à l'établissement de l'historique de conditions rencontrées localement par les cellules. [less ▲]

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See detail(Wrong) representations of physical activity, from definition to recommandations
Cloes, Marc ULg

Conference (2014, July 10)

Faisant partie intégrante de notre vie quotidienne, l’activité physique et la sédentarité constituent deux notions qui s’opposent dans la conception d’un style de vie sain. Les recherches actuelles ... [more ▼]

Faisant partie intégrante de notre vie quotidienne, l’activité physique et la sédentarité constituent deux notions qui s’opposent dans la conception d’un style de vie sain. Les recherches actuelles montrent que chacune d’elles devrait faire l’objet d’une attention particulière. Toutefois, qu’ils fassent partie du grand public ou appartiennent à des professions liées à la santé, il apparait que les individus ne construisent pas toujours des représentations adéquates à propos des bonnes habitudes de vie. Dans la perspective d’influencer favorablement la culture des citoyens en matière d’activité physique, il s’avère donc nécessaire de rappeler régulièrement les informations clés qui devraient être retenues et appliquées dans la vie de tous les jours. Afin d’illustrer la manière avec laquelle les représentations peuvent constituer le fil rouge d’un processus amenant les gens à adopter un style de vie physiquement actif et peu sédentaire, nous passerons brièvement en revue la définition de l’activité physique, l’identification de ses effets et les recommandations proposées actuellement par les agences de santé publique. Nous utiliserons différentes approches ludiques originales, susceptibles de faire vivre aux participants des expériences visant à stimuler le traitement des informations et à privilégier leur rétention. Au niveau de la définition de l’activité physique, l’objectif consistera à faire ressortir les différentes dimensions de l’activité physique. Puisque les recherches les plus récentes en soulignent l’incidence de plus en plus marquée, nous insisterons également sur la distinction entre les différents niveaux d’intensité de la pratique. Ensuite, une classification des effets bénéfiques de l’activité physique sera proposée avant une révision des recommandations internationales. Les modalités de présentation originales qui seront mises en place stimuleront la prise de conscience de certaines mauvaises représentations, courantes dans le public. La dernière partie de l’exposé consistera à illustrer les contre-arguments à opposer à ceux qui ne sont pas encore convaincus qu’ils pourraient bouger davantage. [less ▲]

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See detailApproximation algorithms for multi-dimensional vector assignment problems
Crama, Yves ULg

Conference (2014, July 09)

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See detailL'hôpital, une entreprise comme les autres ? Oui, mais ...
Van Caillie, Didier ULg

Conference (2014, July 07)

A l’instar d’une entreprise industrielle, l’hôpital actuel présente les caractéristiques suivantes, quel que soit son statut ou sa localisation : Il est constitué d’un ensemble de ressources rares et ... [more ▼]

A l’instar d’une entreprise industrielle, l’hôpital actuel présente les caractéristiques suivantes, quel que soit son statut ou sa localisation : Il est constitué d’un ensemble de ressources rares et limitées, de nature humaines, techniques, financières et immatérielles (savoirs et connaissances), dont il doit justifier d’une utilisation efficiente (en clair, maximiser le rapport output/coût) en regard des attentes diverses et parfois contradictoires de ses différentes parties prenantes (patients, collaborateurs, autorités de financement, autorités de contrôle) s’il veut remplir le rôle de création de valeur sociétale naturellement dévolu à toute organisation. En terme managérial, son défi quotidien est de : Gérer de manière coordonnée des flux multiples (flux des patients physiques, objets des soins ; flux des médicaments et des traitements, nécessaires à la fluidité du flux des patients ; flux d’information, traduction virtuelle des patients physiques nécessaire lui aussi à la fluidité du flux des patients) dans un souci permanent d’efficience multiple : garantir le bon soin au bon patient au bon moment avec l’information suffisante, les médicaments et l’infrastructure adéquate, le tout, au moindre coût. Simultanément, coordonner en permanence l’ensemble des ressources humaines, matérielles et financières de l’organisation, et surtout motiver la principale ressource critique, l’ensemble des collaborateurs (corps médical, corps infirmier, corps technicien de support, corps de support à la gestion), en résolvant de manière continue les défis quotidiens d’une bonne communication interpersonnelle (dans et entre les services), d’une motivation individuelle alignée sur les besoins et les attentes de l’organisation et d’une parfaite coordination avec les attentes du patient. [less ▲]

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See detailTaking Cadaveric Decomposition Chemistry out of Flatland
Stefanuto, Pierre-Hugues ULg; Perrault, K; Stadler, S et al

Conference (2014, July 07)

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See detailINFLUENCE OF PLAYERS’ LEVEL ON RACKET SPEED AND BALL ACCURACY IN THE TENNIS SERVE
Tubez, François ULg; Croisier, Jean-Louis ULg; Cordonnier, Caroline ULg et al

Conference (2014, July 06)

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the ... [more ▼]

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the performance of two specific populations: international players versus national players. In particular, racket speed at impact and accuracy of ball were assessed. METHODS A tennis court was reconstructed in a motion analysis laboratory. The position of the racket was evaluated in 3D at a frequency rate of 200 Hz. Tests were performed on 6 professional players (international level) and 9 non-professional players (national level). Each of them served 25 trials in direction of the “T” area of deuce diagonal. Two squares of 1m² and 2 m² respectively were delimited on the corner of the serve square. The instruction for both groups was to serve in the “T” area with the highest ball speed and minimal ball rotation (flat serve). RESULTS Although the forward speed of the racket at impact was identical between the two groups of players (International 36.35 ± 2.37 m/s and national 36.37 ± 2.90 m/s, p-value 0,991), the accuracy and consistency of serves on the target area is better for international players group (1m² area: International 33% ± 7% and national 14% ± 12%, p-value 0.0053; 2m² area (including 1m² area): International 71% ± 8% and national 54% ± 12%, p-value 0.0096; Out of zone: International 29% ± 8% and national 46% ± 12%, p-value 0.014). DISCUSSION High-velocity ball seems to be a key factor for serve performance (3). It is known that there is a relationship between racket speed and ball velocity (4). Both groups have high racket speed. However, international players serve with better accuracy and consistency than national players. We hypothesize that these differences are due to capacity of international players to adapt to a particular environment. Moreover, international players could give priority to consistency over velocity. We conclude that high-velocity serve is not a sufficient criterion to perform at international level; consistency and accuracy are two important factors to reach this level. [less ▲]

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See detailLe roi Léopold et la Commission nationale des sciences
Pirot, Pascal ULg

Conference (2014, July 05)

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See detailThe Belgian Monuments Men During and After the Second World War
Houbart, Claudine ULg

Conference (2014, July 04)

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See detailHMA4 and metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg

Conference (2014, July 04)

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See detail"Faire voir par l'histoire" : l'usage du passé contre Mazarin durant la Fronde
Saal, Caroline ULg

Conference (2014, July 04)

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See detailLet's Talk Ambiguity: Citizen science in new and emerging technologies
Van Oudheusden, Michiel ULg

Conference (2014, July 04)

Citizen science (CS) is a fairly new concept that is rapidly gaining traction in the industrialized democratic world. Although it is often likened to public participation in science, CS takes on many ... [more ▼]

Citizen science (CS) is a fairly new concept that is rapidly gaining traction in the industrialized democratic world. Although it is often likened to public participation in science, CS takes on many forms and orientations. In this presentation, I link CS developments and practices to the advent of new and emerging technologies (NEST), such as bio- and nanotechnologies. I draw on three Flemish cases of CS linked to NEST to illustrate how CS co-evolves with Flemish and European policy shifts towards responsible innovation governance. The cases serve to highlight how various conceptions of CS enact divergent rationales for public involvement in science and promote competing visions of the volatile relationship between science and society. The clash of CS perspectives within and through NEST produces a highly ambiguous innovation context that is simultaneously characterized by excitement and (pre)caution; public and formal expertise; policy dictates and public dialogue; and deterministic and constructionist views of innovation. How implicated actors (policymakers, scientists, citizens, and other stakeholders) make sense of, and deal with, these ambiguities is one of the key challenges CS faces today. [less ▲]

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See detailThe emergence of hybrids: Imprinting from the entrepreneurial team heterogeneity
Dufays, Frédéric ULg; Huybrechts, Benjamin ULg

Conference (2014, July 03)

This conceptual paper deals with the emergence of hybrids by developing a process model that crosses levels of analysis. It aims to explain how heterogeneity in an entrepreneurial team may translate into ... [more ▼]

This conceptual paper deals with the emergence of hybrids by developing a process model that crosses levels of analysis. It aims to explain how heterogeneity in an entrepreneurial team may translate into the creation of a hybrid organization. [less ▲]

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See detailAnalyse de l’efficacité de l’accoutumance à l’eau chez l’enfant préscolaire
Mornard, Manhattan ULg; Jidovtseff, Boris ULg; Deflandre, Dorian ULg et al

Conference (2014, July 02)

Beaucoup d’enfants suivent des cours d’accoutumance à l’eau et différentes approches existent. Cette étude vise à comparer deux de ces méthodes et d’en vérifier l’efficacité. Nous avons soumis à trois ... [more ▼]

Beaucoup d’enfants suivent des cours d’accoutumance à l’eau et différentes approches existent. Cette étude vise à comparer deux de ces méthodes et d’en vérifier l’efficacité. Nous avons soumis à trois groupes d’enfants une batterie de tests complète. Vingt-cinq enfants bénéficiaient d’une méthode traditionnelle (TRADITION), 25 autres de la méthode CEReKi (CEREKI) et les 27 derniers ne suivaient aucun cours (CONTRÔLE). Tous ont été testés avant et après une période de cinq mois. L’approche pédagogique des deux écoles a été analysée durant 13 séances filmées. On observe une amélioration linéaire du niveau d’accoutumance à l’eau des enfants en fonction de leur âge qu’ils suivent ou non des cours. Les résultats démontrent l’efficacité des deux écoles. Les enfants CEREKI semblent s’améliorer autant mais en moins de séances. Cela peut être dû à un meilleur temps d’engagement moteur. La méthode CEREKI s’avère donc très efficace, même dans une piscine peu adaptée. [less ▲]

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See detailDiurnal thermosphere scale height from MEX/SPICAM grazing limb data
Stiepen, Arnaud ULg; Gérard, Jean-Claude ULg; Bougher, S et al

Conference (2014, July 01)

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See detailConstraints on the summer-to-winter transport from SPICAM/MEX nitric oxide observations
Stiepen, Arnaud ULg; Gérard, Jean-Claude ULg; Gagné, M.-E. et al

Conference (2014, July 01)

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See detailBeyond the limits of a deductive approach based on ideal types and configurations
Moreau, Charlotte ULg; Pichault, François ULg; Mertens de Wilmars, Sybille ULg

Conference (2014, July)

This paper presents an original theoretical model combining ideal-types and bundles in order to apprehend a poorly studied phenomenon, the professionalization of human resource management (HRM) in social ... [more ▼]

This paper presents an original theoretical model combining ideal-types and bundles in order to apprehend a poorly studied phenomenon, the professionalization of human resource management (HRM) in social enterprises. This theoretical model elaborated from a literature review fits into a deductive approach. The first objective of this contribution is to show the added values and limits of such an a priori conceptualization. By replacing that model within the contextualist framework of analysis (Pettigrew, 1987) and by equipping that approach with adapted methodologies, some limits inherent in a deductive approach are avoided. The second goal of this paper is then to demonstrate how such a combination helps to pass over the limits of the theoretical model based on bundles and ideal types. [less ▲]

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See detailFormal and semantic-discursive properties of mirative exprecctions (it's) no wonder: a synchronic-diachronic approach
Gentens, Caroline; Brems, Lieselotte ULg; Davidse, Kristin et al

Conference (2014, July)

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See detailDesign of Pt/carbon xerogel catalysts for PEM fuel cells
Job, Nathalie ULg; Lambert, Stéphanie ULg; Zubiaur, Anthony ULg et al

Conference (2014, July)

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See detailMars dayglow review
Stiepen, Arnaud ULg

Conference (2014, July)

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See detailFascination as a Case of Action at a Distance in Early Modern Science
Dubouclez, Olivier ULg

Conference (2014, July)

BUCHAREST-PRINCETON SEMINAR IN EARLY MODERN PHILOSOPHY 14th Edition Organized by the Research Centre for the Foundations of Modern Thought (FME), University of Bucharest, in collaboration with the ... [more ▼]

BUCHAREST-PRINCETON SEMINAR IN EARLY MODERN PHILOSOPHY 14th Edition Organized by the Research Centre for the Foundations of Modern Thought (FME), University of Bucharest, in collaboration with the Philosophy Department at Princeton University 8 – 13 July 2014 Bran, Romania De rerum natura: Naturalism, Super-naturalism, Unnaturalism Invited speakers include: Daniel Garber (Princeton University), Roger Ariew (University of South Florida), Igor Agostini (Università del Salento), Peter Anstey (University of Sydney), Olivier Dubouclez (Université de Liège), Tamás Pavlovits (University of Szeged), Jennifer Rampling (Princeton) Description : https://ci3.googleusercontent.com/proxy/8CBWEZYl_gju-O0mEKjDNw0Eh_qIbYUu1oZBKfZqOypmLO1gU9NfBBUnKK5HrwoN-VKG8iQn_PvQpZDlbxq0IwVL9dQOy_HcGJ0=s0-d-e1-ft#https://mail.google.com/mail/u/0/images/cleardot.gif Some Seventeenth Century authors gave a new definition of nature, clearly articulated in terms of natural laws and of their dependence on God. Even if some elder tensions, coming from the Stoic and Epicurean heritage, were thus released, new challenges appeared, related to the limits of nature (is the world finite or infinite?), the structure of matter, the status of the mind and the status of the human being with respect to nature. While some philosophers as Bruno, Telesio and Cardano tried to reach a compromise with Renaissance vitalism, promoting a natural magic and a new alchemy, some others, such Bacon, Descartes, Spinoza, Leibniz, proposed radical different paths. Not losing sight of the manner in which ancient thought (Pliny and Lucretius seem to be naturally summoned) informed modern debate over nature, the seminar will try to uncover a period in which Spinoza could articulate his critique of Descartes as holding a view of man as "imperium in imperio". The Bucharest-Princeton Seminar in Early Modern Philosophy is an international annual meeting of scholars interested in various aspects of early modern thought. The aim of the seminar is to create a stimulating environment for discussing papers and ideas. It includes workshops in the morning and presentations of papers in the afternoon, where participants can present work in progress. While the morning sessions will focus on the theme of “De rerum natura: Naturalism, Super-naturalism, Unnaturalism,” the afternoon sessions seek to give participants an opportunity to discuss their own special interests with an open and sympathetic audience of students and scholars with broad interests in early modern thought. Throughout we try to maintain a balance between the high scholarly level and the informal friendly spirit of a colloquium. The Seminar will take place in Bran, a small mountain resort near Brasov, in Transylvania. It will be hosted in a small, friendly Bed and Breakfast (single or double rooms). The participation fee is 150 EUR for faculty and 90 EUR for students (covering accommodation with breakfast). We invite applications for contributions (from researchers) and for attendance (from students). If you want to contribute a paper, please send a CV and a one-page abstract, and if you want to attend, a CV and a letter of intent – by April 20 – to Vlad Alexandrescu (valexandrescu@gmail.com), Dana Jalobeanu (dana.jalobeanu@celfis.ro). [less ▲]

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See detailWhich are the determinants of homeownership ? A logit analysis for the case of Belgium
Xhignesse, Guillaume ULg; Bianchet, Bruno ULg; Cools, Mario ULg et al

Conference (2014, July)

In market-oriented economies, high rates of homeowners are traditionally associated with positive economic effects and externalities. For this reason, public authorities have encouraged homeownership for ... [more ▼]

In market-oriented economies, high rates of homeowners are traditionally associated with positive economic effects and externalities. For this reason, public authorities have encouraged homeownership for the last decades through taxation or subsidies policies. In Belgium, owner-occupation has been promoted since the end of the nineteenth century and homeownership policy is considered as a key element of the Welfare state. Furthermore, the effectiveness of these policies is fundamentally based on a clear understanding of what determines homeownership. Therefore, the analysis of tenure determinants can provide inputs for the definition or the renewal of housing, taxation and subsidies policies. Considering this interest, this paper investigates the issue of housing tenure in Belgium. On the basis of previous related research, a model of tenure choice is estimated using a sample of 6,962 households. The observations follow clearly the general trends described for other countries. Higher income and age, couple status and the presence of dependent children have positive influences on homeownership. In addition, locations presenting a high density of population and a high centrality are associated with a lower probability of homeownership compared with other areas. The underlying significations of these variables are discussed in the paper. [less ▲]

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See detailA Multiphycics approach to calculate shear stresses during neotissue growth in perfusion bioreactor
Guyot, Yann ULg; Papantoniou, Ioannis; Schrooten, Jan et al

Conference (2014, July)

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See detailGay and Lesbian Families Well-Beeing: Respectively Ten and Seven years after the legalization of Same-sex Marriage and Same-sex Adoption in Belgium, understanding heterosexual adults' attitudes.
Scali, Thérèse ULg; D'Amore, Salvatore ULg; Green, Robert-Jay

Conference (2014, July)

Belgium is one of the first European country to legalize marriage and adoption for same-sex couples (respectively in 2003 and 2006) and to state anti-discrimination laws (2008). Despite the legalization ... [more ▼]

Belgium is one of the first European country to legalize marriage and adoption for same-sex couples (respectively in 2003 and 2006) and to state anti-discrimination laws (2008). Despite the legalization, what can we say about adults’ attitudes? This study is part of an international project, and aims at studying the attitudes towards different kind of same-sex constellations – single gays and lesbians, couples, and families – and at examining the correlates to those attitudes. Attitudes were assessed through self-report questionnaires in a cohort of 366 heterosexual participants resident in Belgium, 72% females and 28% males aged from 26 to 40 (age class corresponding to transition lifecycle and parenting choices). Participants were asked to answer socio-demographic questions and to self-report their contact with homosexual people (frequency and satisfaction). Then different scales assessed their attitudes toward homosexuality (General Attitudes Toward Homosexuality, Da Costa, 2011; ATLG, Herek), same-sex marriage (Katuzny Scale on Same-Sex Marriage, 2012) and different types of same¬-sex parenting – adoption, alternative insemination, in vitro, ovocyte donation (D’Amore & Green Homoparentality Scale, 2012). It is hypothesized that correlates to positive attitudes will be associated with female gender, lower religiosity, non-protestant religions, liberal political ideology, and higher education and socioeconomic status. This presentation contributes to a better understanding of Belgian’s attitudes toward same-sex couples and same-sex families, by measuring the predictive variables of positive and negative attitudes. [less ▲]

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See detailLink between learning profile and school achievement in primary school; a transversal study
Frenkel, Stéphanie ULg; Nobile, Debora ULg

Conference (2014, July)

School achievement plays an essential role in terms of professional and social adaptation. However, all the students do not always perform as the system requires them to. In Belgium, at the end of ... [more ▼]

School achievement plays an essential role in terms of professional and social adaptation. However, all the students do not always perform as the system requires them to. In Belgium, at the end of compulsory education, one student out of two lags behind in their school education (Indicators from the Fédération Wallonie-Bruxelles [Walloon-Brussels Federation], 2012). In this context, we do not consider that there are “bad” learners. Instead, there are those students whose learning profile is more or less in line with the context’s requirements and those whose profile is not. In many works, the student’s learning profile is operationalised by measures on 3 levels: cognitive, metacognitive and psycho-affective. These psychological variables, which are major components of self-regulated learning, play a central role in the explanation of school performance (for more details, see Frenkel, in press; Frenkel & Deforge, in press). This profile is not fixed once and for all. It evolves over time and it represents the result of the interaction between these three variables with other factors, notably bio-medical, socio-demographical ones, factors related to family environment (Pourtois, Desmet & Lahaye, 2004; Trudel, Puentes-Neuman & Ntebutse, 2002) and the too often forgotten factors linked to class management and social interactions between students and teachers (see Wang, Haertel & Walberg, 1994). Determining the students’ learning profile enables us to identify their strengths and work on their weaknesses. Therefore, it is essential that psycho-educational teams have validated tools at their disposal in order to carry out this task. Our aim is to propose new tools which will complement the already-existing ones. In this presentation we propose to introduce and discuss our methodology and the results obtained. The starting target population was made up of 198 primary school students divided equitably into three levels (second year of primary school, fourth year of primary school and sixth year of primary school). A problem-solving task based on the DELF (Büchel & Büchel, 1995) was created. It was completed by two questionnaires to fill in before and after the task. The learning profile defined on this basis was analysed according to several variables (age, gender, socio-professional category, school results). Group testing is still in progress. We will also illustrate our presentation with the first results of individual testing which will begin in May 2014. References - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive - Frenkel, S. (in press). Metacognitive components in learning to learn approaches. International Journal of Psychology: A Biopsychosocial Approach - Frenkel, S., & Deforge, H. (in press). Métacognition et réussite scolaire: Perspectives théoriques. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université - Pourtois, J.-P., Desmet, H., & Lahaye, W. (2004). Connaissances et pratiques en éducation familiale et parentale. Enfances, Familles, Générations, 1, 22-35 - Trudel, M., Puentes-Neuman, G., & Ntebutse J.G. (2002). Les conceptions contemporaines de l’enfant à risque et la valeur heuristique du construit de résilience en éducation. Revue Canadienne de l’Education, 27 (2 & 3), 153-173 - Wang, M.C., Haertel, G.D., & Walberg, H.J. (1994). What helps students learn? Educational Leadership, 51 (4), 74-79 [less ▲]

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See detailMars aurora review
Stiepen, Arnaud ULg

Conference (2014, July)

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See detailInverting Hydraulic Heads In An Alluvial Aquifer Constrained With Electrical Resistivity Tomography Data Through Multiple-Point Statistics And Probability Perturbation Method: A Case Study
Hermans, Thomas ULg; Scheidt, Celine; Caers, Jef et al

Conference (2014, July)

Solving spatial inverse problems in the Earth Sciences remains a considerable challenge given the large number of parameters to invert for, the non-linearity of forward models and as a result the ill ... [more ▼]

Solving spatial inverse problems in the Earth Sciences remains a considerable challenge given the large number of parameters to invert for, the non-linearity of forward models and as a result the ill-posedness of the problem. Geostatistics is therefore needed to specify prior models, more particularly, information to control the spatial features of the inverse solutions. We used multiple-point statistics (MPS) to build models of pre-defined hydrofacies: clay, sand and gravel facies constrained to geological data (hard data) and geophysical data (soft data). The electrical resistivity tomography method was chosen to bring relevant spatially distributed information on the presence of the facies, given its sensitivity to variations in lithology and porosity. The comparison of the geophysical signature of the deposits with direct observations in boreholes enables to derive the conditional probability of observing a facies given its electrical resistivity. This is used to produce probability maps for each facies and constrain stochastic simulations of the alluvial aquifer. Then, the probability perturbation method (PPM) is used to integrate hydraulic heads data, using MPS to generate models. This process enables us to obtain calibrated models of the aquifer. The PPM algorithm will automatically seek solutions fitting both hydrogeological data and training-image based geostatistical constraints. Only geometrical features of the model are affected by the perturbation, i.e. we do not attempt to directly find the optimal value of hydrogeological parameters (chosen a priori), but the optimal spatial distribution of facies whose prior distribution is quantified in a training image. The methodology is first tested with a synthetic benchmark. The tests performed show that the choice of the training image is a major source of uncertainty. Therefore, one first needs to select those training images consistent with the geophysical data (and hence reject the inconsistent ones). Then, we proceed with them to hydrogeological inversions. Geophysical data (soft constraints) acts as an accelerator of convergence by reducing prior uncertainty. The hydraulic conductivity of each facies is a sensitive parameter, but it can be easily optimized prior to the PPM process. The stochastic method is then successfully applied within the context of an alluvial aquifer submitted to a pumping experiment. We show how the integration of various sources of data (borehole logs, geophysics, hydraulic heads) aids in calibrating hydrogeological models, locating high hydraulic conductivity zones and reducing uncertainty. The developed methodology proposes a common framework (multiple-point statistics) to integrate various information sources with variable resolutions relevant for hydrogeology: geological, geophysical and hydrogeological data. The method can be extended to integrate tracer tests to enable the calibration of transport parameters as well. The originality of the method is to use geophysical data both to refine the choice of the training image and to constrain the inversion of hydrogeological models. [less ▲]

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See detailSynthesis of Pt/Carbon Xerogel Electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC): Effect of the Reduction Procedure
Zubiaur, Anthony ULg; Chatenet, Marian; Maillard, Frédéric et al

Conference (2014, July)

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See detailMetacognition and school learning: Individual use of the DELV program with teenagers
Frenkel, Stéphanie ULg; Nobile, Debora ULg

Conference (2014, July)

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010 ... [more ▼]

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010, 2011). It includes 8 types of decontextualized exercises which notably allow to develop the learner’s metacognitive knowledge and skills (for more details, see Büchel, 2013b). They also make it possible to work on cognitive and psycho-affective aspects. Transfer can thus be better developed. This tool has been used since its first version (Büchel & Büchel, 1995) both at the Atelier d’Apprentissage of the University of Genève (Unige, Switzerland) and at that of the University of Liège (ULg, Belgium) since their creation (respectively in 1996 and in 2009), (for more details, see Büchel, 2013a; Frenkel, in press (b)). Our main purpose is to present how we can use this tool individually in order to enable the student to activate his/her “sleeping potential” (for more details, see Frenkel, in press (a)). By focusing on adolescence, we will present (a) our theoretical background (conception of learning and intellectual functioning, criteria and levels of mediation), (b) the variables worked on, and (c) the results obtained. Note: Part of the Psychological and Speech therapy consultation Centre (CPLU, ULg), Belgium’s Atelier d’Apprentissage [Learning Workshop] intended for children and teenagers with temporary school learning difficulties. See www.cplu.ulg.ac.be References - Büchel, F.P. (2013a). L’intervention psychopédagogique auprès des enfants ayant des difficultés d’apprentissage. Un modèle métacognitif et d’autorégulation. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 71- 105). Nice, France: Les Editions Ovadia. - Büchel, F.P. (2013b). Le programme DELV – Comprendre son propre apprentissage. Evaluation scientifique auprès d’enfants et d’adolescents sans ou avec difficultés d’apprentissage. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 293-336). Nice, France: Les Editions Ovadia. - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive. - Büchel, F.P., & Büchel, P. (1997). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens und Denkens für Jugendliche und Erwachsene. Aarau, Switzerland: Sauerländer. - Büchel, F.P. & Büchel, P. (2010). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (4. überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2011). DELV. Comprendre son propre apprentissage. Tegna, Suisse: Centre d’éducation cognitive. - Frenkel, S. (in press (a)). Metacognitive components in learning to learn approaches. International Journal of Psychology: A Biopsychosocial Approach. - Frenkel, S. (in press (b)). Métacognition et réussite scolaire : Applications. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université. - Frenkel, S., & Deforge, H. (in press). Métacognition et réussite scolaire: Perspectives théoriques. In C. Giraudeau & G. Chasseigne (Eds.), Psychologie, Education et Vie scolaire. Tours, France: Editions Publibook Université. [less ▲]

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See detailThe concept of economic security of the hospital: A new look at the levers of control
Shutyak, Yuliya ULg; Van Caillie, Didier ULg

Conference (2014, July)

Despite a significant progress achieved in the healthcare sector during last decades, we need to admit the fact that many urgent problems remain unsolved even in well developed countries. Along with other ... [more ▼]

Despite a significant progress achieved in the healthcare sector during last decades, we need to admit the fact that many urgent problems remain unsolved even in well developed countries. Along with other major factors, economic causes of these problems hold a prominent position. It is then necessary to think about a need of shifting from a view of hospitals as ever being institutions existing by default in any society to a view of hospitals as organisations with an incorporated economic mechanism, adapted to social changes and relevant economic risks. With this regard, this paper seeks to incorporate the concept of economic security of the hospital into Simons’ LOC model used in hospital management. We provide a brief overview of the concept of economic security of the organization. We adjust this concept for hospital management considering the healthcare system as an economic system and taking main problems of the hospital and interests of stakeholders in the core of strategy development. Further, we accommodate the concept with the levers of control. The result of the paper is a revised Simons’ LOC model which provides a theoretical framework for further research on hospital management and serves a modified management instrument. [less ▲]

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See detailNegation, grammaticalization and subjectification: the development of polar, modal and mirative no way-constructions
Davidse, Kristin; Brems, Lieselotte ULg; Lesage, Jakob et al

Conference (2014, July)

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See detailIdentifying codes in vertex-transitive graphs
Gravier, Sylvain; Parreau, Aline ULg; Rottey, Sara et al

Conference (2014, July)

We consider the problem of computing identifying codes of graphs and its fractional relaxation. The ratio between the optimal integer and fractional solutions is between 1 and 2 log(|V|) where V is the ... [more ▼]

We consider the problem of computing identifying codes of graphs and its fractional relaxation. The ratio between the optimal integer and fractional solutions is between 1 and 2 log(|V|) where V is the set of vertices of the graph. We focus on vertex-transitive graphs for which we can compute the exact fractional solution. There are known examples of vertex-transitive graphs that reach both bounds. We exhibit infinite families of vertex-transitive graphs with integer and fractional identifying codes of order |V|^a with a in {1/4, 1/3, 2/5}. These families are generalized quadrangles (strongly regular graphs based on finite geometries). They also provide examples for metric dimension of graphs. [less ▲]

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See detailMars nightglow review
Stiepen, Arnaud ULg

Conference (2014, July)

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See detail3D MODELING OF SHEAR STRESS DEVELOPMENT DURING NEOTISSUE GROWTH IN A PERFUSION BIOREACTOR
Guyot, Yann ULg; Papantoniou, Ioannis; Schrooten, Jan et al

Conference (2014, July)

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See detailBoard attributes and accounting conservatism: Evidence from French firms
Boussaid, Nabila ULg; Sougné, Danielle ULg; Hamza, Taher

Conference (2014, July)

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See detailRecollection and familiarity in normal and pathological aging
Bastin, Christine ULg

Conference (2014, July)

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See detailStability and bifurcation analysis of a Van der Pol–Duffing oscillator with a nonlinear tuned vibration absorber
Habib, Giuseppe ULg; Kerschen, Gaëtan ULg

Conference (2014, July)

The Van der Pol (VdP) oscillator is a paradigmatic model for description of self-excited oscillations, which are of practical interest in many engineering applications. In this paper the dynamics of a VdP ... [more ▼]

The Van der Pol (VdP) oscillator is a paradigmatic model for description of self-excited oscillations, which are of practical interest in many engineering applications. In this paper the dynamics of a VdP-Duffing (VdPD) oscillator with an attached nonlinear tuned vibration absorber (NLTVA) is considered; the NLTVA has both linear and nonlinear restoring force terms. In the first part of this work, the stability of the trivial solution of the system is investigated, following results of previous works. The analysis allows to define an optimal tuning rule for the linear parameters of the absorber, which substantially enlarges the domain of safe operation of the primary system. In this case, the system loses stability through a double Hopf bifurcation. In the second part of this work, the bifurcations occurring at the loss of stability are analytically investigated, using the technique of the center manifold reduction and transformation to normal form. The obtained results show the effects of the nonlinear parameter of the absorber, which, in turn, allows to define its optimal value in order to avoid subcriticality and reduce the amplitude of self-excited oscillations. [less ▲]

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See detailLa flexicurité : vers une carrière transitionnelle?
Beuker, Laura ULg

Conference (2014, July)

Ces dernières années, les institutions Européennes ont joué un rôle clé dans la régulation et l’orientation des politiques publiques pour l’emploi des États-membres (Amparo-Serrano et Martin-Martin, 2012 ... [more ▼]

Ces dernières années, les institutions Européennes ont joué un rôle clé dans la régulation et l’orientation des politiques publiques pour l’emploi des États-membres (Amparo-Serrano et Martin-Martin, 2012). Dans ce cadre, la flexicurité s’est imposée comme une référence des politiques en matière de droit du travail, d’emploi, de sécurité sociale et de formation professionnelle (Conter et Orianne, 2011). En Belgique, cette exigence d’allier flexibilité et sécurité sur le marché du travail a constitué le cœur de nombreux discours et programmes politiques, pour finir par s’estomper progressivement, à la suite de crises financières et économiques l’ayant fortement éprouvé. Ce « concept » a-t-il pour autant effectivement disparu ? À partir d’une étude qualitative basée sur des entretiens semi-directifs menés auprès d’acteurs institutionnels – experts et analystes du marché du travail – nous nous sommes rendu compte que si la sémantique n’est plus, les principes de flexicurité sont, quant à eux, toujours présents dans le discours des individus. De plus, ces principes semblent détenir une portée normative de taille quant à la redéfinition de l’articulation des temporalités sociales : d’une sécurité de l’emploi, nous serions en train d’effectuer un glissement vers une sécurité en emploi de l’individu. La rhétorique n’est pas innocente : désormais, ce n’est plus tant l’individu qu’il s’agit de protéger (droit du travail, etc.) mais bien les transitions – multiples et sinueuses – opérées par ce dernier. Pour y parvenir, l’État le responsabilise : il doit désormais être capable de se prendre en mains : « c’est le passage d’un ‘État qui protège’ à un ‘État qui rend capable’ » (Vrancken, 2008). [less ▲]

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See detailEvaluation of process-driven spray retention model on ear-ly growth stage barley
Massinon, Mathieu ULg; Ouled Taleb Salah, Sofiene ULg; De Cock, Nicolas ULg et al

Conference (2014, July)

The efficiency of spray application of foliar plant protection products with hydraulic nozzles on vertically oriented and hydrophobic plants at early growth stages can be very low. The spray retention by ... [more ▼]

The efficiency of spray application of foliar plant protection products with hydraulic nozzles on vertically oriented and hydrophobic plants at early growth stages can be very low. The spray retention by crop leaves is affected by application parameters resulting from nozzle kind, size and operating pressure as well as spray mixture physicochemical properties. When optimizing the spray application, such targets are often used to perform retention trials for comparative purpose, i.e. indoor grown monocotyledonous at two leaves stage. A typical arrangement consists in spraying few plants sufficiently spaced underneath the nozzle to avoid interference due to secondary droplets from impacts on other plants. However, retention trials turn out to ineffective for significantly discriminating between application methods and mixtures due to the high variability between trials resulting from the different droplets retained by each plant. An alternative to retention trials is to tackle spray retention with a physical approach at the droplet scale. Such tests are often performed using high speed imaging with high magnification optics to characterize droplet impacts; adhesion, rebound or shatter on small excised leaf areas and neglect, however, the overall plant architecture. The aim of this paper is to evaluate a droplet interception model connecting actual spray retention with process-driven retention models. In this study, barley plants (BBCH11) were sprayed with 2 formulations using the same nozzle. The actual spray retention was assessed by dosing a fluorescent tracer added to the sprayed mixture. The plants were placed linearly below the center of a single moving nozzle during sprayings. Each plant was reconstructed in 3D afterwards using a structured light 3D scanner and used as input for the model. A virtual nozzle was built on the base of droplet size distributions measured with high speed shadow imaging by performing an adjustment of the distribution by the method of moments. A ran-dom droplet distribution was allocated for each spraying of a barley plant. Droplet velocities were given to droplets on the basis of the droplet velocity – diameter correlation by resolving the droplet transport equations for different droplet sizes. Initial droplet positions were ran-domly given. The interception model is based on a mathematical formalism for the intercep-tion between triangles of the 3D plant and droplet directions. If the droplet impacts a leaf, the amount actually retained by the leaf was computed on the basis of the droplet impact energy and impact behavior from experiments with high speed shadow imaging. In conclusion, the interception model allowed determining the spray retention by plants and discriminating ap-plication parameters by explaining the variability resulting from various droplet size distribu-tions intercepted by single plant. [less ▲]

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See detailLe questionnaire en recherche !
Pétré, Benoît ULg; Guillaume, Michèle ULg

Conference (2014, June 28)

Les pratiques médicales et paramédicales doivent prendre appui aujourd’hui sur les données dites probantes. Autrement dit, les données issues de la recherche guident l’action des professionnels de santé ... [more ▼]

Les pratiques médicales et paramédicales doivent prendre appui aujourd’hui sur les données dites probantes. Autrement dit, les données issues de la recherche guident l’action des professionnels de santé! La qualité des résultats attendus au terme d’un processus de recherche dépend profondément de la qualité de l’outil de collecte des données utilisé. Parmi les outils disponibles, le questionnaire est certainement celui le plus utilisé dans le domaine de la recherche médicale et paramédicale. Si la conception d’un questionnaire parait simple aux premiers abords, une lecture plus fine des principes qui sous-tendent la mesure (fidélité, validité, objectivité) rend compte des difficultés rencontrées pour développer un outil de qualité. Après avoir resitué le questionnaire dans le processus plus général de la recherche, les étapes de construction du questionnaire seront précisées et les qualités de l’outil seront discutées. Cette présentation permettra la mise en lumière des avantages et des limites inhérentes au questionnaire. Il sera démontré que nul questionnaire n’est parfait et que les inférences et les interprétations qui peuvent être tirées des informations recueillies à partir de cet outil, doivent être réalisées avec précaution. [less ▲]

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See detailLes botanistes verviétois au XIXème siècle
Genin, Vincent ULg

Conference (2014, June 28)

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See detailWorkshop on Pitch Analysis for Singing
Larrouy, Pauline ULg

Conference (2014, June 28)

Two methods are actually used in order to determine if a vocal performance is “in tune” or “out of tune”, to better understand the causes of poor-pitch singing or to evaluate the quality/progression of a ... [more ▼]

Two methods are actually used in order to determine if a vocal performance is “in tune” or “out of tune”, to better understand the causes of poor-pitch singing or to evaluate the quality/progression of a singer. The "subjective" method makes use of judges whereas the "objective" method uses computer tools to perform pitch analysis and to estimate the accuracy of sung performances. While the first method allows a rapid assessment, it lacks precision, which explains that the “objective” method seems currently preferred. However, several computer tools are available and each laboratory has its preference. In addition, the analytical procedure will depend on the purpose and data of the study. This workshop aims to provide an overview of the tools available and to discuss the advantages and limitations of existing methods. [less ▲]

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See detailPitch fluctuations in accurate and inaccurate singers: are they the same?
Larrouy, Pauline ULg; Pfordresher, Peter Q

Conference (2014, June 28)

The research presented here attempts to explore the fine-control of pitch during singing among accurate occasional singers and individuals whose singing reflects a Vocal Pitch Imitation Deficit (VPID ... [more ▼]

The research presented here attempts to explore the fine-control of pitch during singing among accurate occasional singers and individuals whose singing reflects a Vocal Pitch Imitation Deficit (VPID). Most past research addresses individual differences at the level of entire sung notes or melodies. By contrast, in the present research we addressed whether VPID singers differ from accurate singers with respect to the way to reach, maintain, and stop a sung tone. In order to describe the “scoops” at the beginning and ends of tone, as well as other forms of instability, we adapted the model of Large et al. (2002), originally designed to model entrainment of timing during synchronization. This model was applied to 1461 notes performed by 12 VPID and 17 accurate singers from the database of Pfordresher and Mantell (2014). Finally, the parameter values across the VPID and accurate singers were compared. The results showed that the model fits tones performed by accurate and VPID singers similarly well. As expected, the median pitch across the entire sung note deviated from the target to imitate for VPID singers; at the same time, the proportion of these deviations that were overshoots (“sharp”) versus undershoots (“flat”) were the same for VPID and accurate singers (2/3rd under and 1/3rd above). Thus accurate and VPID singers differ in the magnitude but not the type of overall deviation they exhibit. Whereas no difference occurred between the singers regarding the direction of the scoop (up or down) at the start and the end of the tone, the amplitude of the scoops was significantly different between VPID and accurate singers. The present study highlights the difficulty of VPID singers to reach and stop a sung tone, which supports the hypothesis of a fine motor control deficit in this population. Furthermore, the pitch fluctuations described by the model would have to be investigated in research on pitch accuracy perception. [less ▲]

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See detailBone markers in patients with CKD
CAVALIER, Etienne ULg

Conference (2014, June 26)

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See detailA probabilistic model of the adhesive contact forces between rough surfaces in the MEMS stiction context
Hoang Truong, Vinh ULg; Wu, Ling ULg; Arnst, Maarten ULg et al

Conference (2014, June 26)

Stiction is a common failure mechanism in microelectromechanical systems (MEMS) in which two interacting bodies permanently adhere together. This problem is due to the comparability of adhesive surface ... [more ▼]

Stiction is a common failure mechanism in microelectromechanical systems (MEMS) in which two interacting bodies permanently adhere together. This problem is due to the comparability of adhesive surface forces (e.g. Van der Waals forces, capillary forces) and body forces in the MEMS context. To predict the adhesive contact forces coupled with stiction phenomenon, the combination of the Nayak statistical approach with the asperity-based theories is a common solution. However, this method contains some limitations due to the underlying assumptions: infinite size of the interacting rough surfaces and negligibility of asperity interactions. Furthermore, the Nayak solution suffers from a considerable dependency on the choice of the minimum wave length considered in the surface representation, which remains diXcult to select. The main goal of our research is to propose an improved method (i) which accounts for the Vnite size of the interacting surfaces, (ii) accounts for the uncertainties related to these surface topologies, (iii) in which the minimum wave length selection is physically based, and (iv) in which the validity of the asperity-based theories is demonstrated. From the topology measurements of MEMS samples, an analysis of the power spectral density function is carried out to determine the minimum relevant wave length for the problem of interest (here capillary stiction). We also show that at this scale of interest the asperity-based theories remain valid for polysilicon materials. Moreover, instead of considering inVnite surfaces as in the Nayak approach, a set of surfaces, whose sizes are representative of the MEMS structure, is generated based on the approximated power spectral density analysis and using the Monte Carlo method. From this description of the contacting surfaces, the adhesive contact forces can be evaluated by applying the asperity contact theories, leading to a probabilistic distribution of the adhesive contact forces. In addition, as the contact forces are rooted from the micro-scale adhesive forces, while their consequence, stiction, happens at the macro-scale of the considered device, the multi-scale nature of the phenomenon is accounted for. To predict this macro-scale behavior in a probabilistic form, the uncertainty quantiVcation process is coupled with a multiscale analysis. [less ▲]

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See detailVehicle routing problems with multiple trips: using specific local search operators
Arda, Yasemin ULg; Crama, Yves ULg; François, Véronique ULg et al

Conference (2014, June 25)

In vehicle routing problems with multiple trips (VRPM), each vehicle is allowed to perform more than one trip during its working period. Classical solution techniques for this problem make use of existing ... [more ▼]

In vehicle routing problems with multiple trips (VRPM), each vehicle is allowed to perform more than one trip during its working period. Classical solution techniques for this problem make use of existing VRP heuristics to create trips, together with bin packing methods aimed at assigning these trips to the available vehicles. The first contribution of this work is to propose specific local search operators for the VRPM. The operators directly integrate the multi-trip structure of the problem within well-known VRP operators. As a second contribution, heuristics using these operators are compared with classical solution techniques mentioned above. The comparison is performed by using the adaptive large neighborhood search metaheuristic as a common basis for both methods. The most classical version of the problem is studied as well as a variant involving time windows [less ▲]

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See detailStandardisation of 25(OH)-vitamin D assays: beware of limitations
CAVALIER, Etienne ULg

Conference (2014, June 24)

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