Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailDes Châtelperroniens en rouge et noir : l'exploitation des matériaux colorants dans la grotte du Renne à Arcy-sur-Cure, Yonne
Salomon, Hélène ULg; Coquinot, Yvan; Vignaud, Colette et al

in Paléo (in press)

Depuis une décennie, les découvertes de matériaux colorants se multiplient parmi les sites dont les occupations remontent au Paléolithique moyen et au Paléolithique supérieur ancien. L’intérêt qu’elles ... [more ▼]

Depuis une décennie, les découvertes de matériaux colorants se multiplient parmi les sites dont les occupations remontent au Paléolithique moyen et au Paléolithique supérieur ancien. L’intérêt qu’elles suscitent tient à ce qu’elles sont susceptibles de révéler des pratiques techniques diverses et complexes, mais il tient aussi à leur forte potentialité à traduire des pratiques symboliques du fait de leur pouvoir colorant intense et des couleurs exploitées : le rouge et le noir. C’est sur le gisement châtelperronien de la grotte du Renne à Arcy-sur-Cure (Yonne), fouillé de 1949 à 1963 par André Leroi-Gourhan, qu'environ 2000 matières colorantes découvertes ont conduit à échafauder des théories concernant leurs transformations et leurs utilisations qui méritaient d’être éprouvées. Il est supposé, depuis leur découverte, qu’elles ont fait l’objet d’un chauffage contrôlé qui visait à en modifier la couleur, le chauffage permettant de transformer les matières colorantes jaunes (hydroxydes de fer) en orangé, en rouge et en violacé (oxydes de fer). De cette hypothèse découle la théorie selon laquelle les Néandertaliens ont exploité les matières colorantes en tant que pigment pour des réalisations symboliques, voire d’ordre esthétique, ce qui n’a pas encore pu être prouvé. La présente étude, fondée sur le croisement des données issues des analyses de la nature physico-chimique et pétrographique des assemblages de matières colorantes, mais aussi sur leur intégration dans le gisement, en association avec des structures d’habitat dont la conservation est exceptionnelle, et sur une série d’expérimentations visant à caractériser les poudres obtenues par différents moyens a permis de définir les choix techniques qui ont présidé à l’approvisionnement en matières colorantes dans tous les niveaux d’occupation châtelperroniens de la grotte du Renne. Il a ainsi été possible de démontrer qu’aucune des matières colorantes, rouges ou noires, n’a fait l’objet d’un chauffage préalablement à son utilisation, bien au contraire de ce qui avait été supposé jusqu’ici. Ces matières colorantes ont fait l’objet d’un approvisionnement raisonné auprès de formations géologiques affleurant ponctuellement. L’exploitation de ces gîtes de matières premières colorantes a été la même durant toute la séquence châtelperronienne et s’est orientée préférentiellement vers des matériaux que l’on peut aisément réduire en poudre. L’assemblage des matières colorantes de la grotte du Renne révèle à la fois une permanence des pratiques techniques et culturelles qui ont trait à l’emploi de matières colorantes et un profond ancrage des connaissances et de la compréhension des multiples propriétés et qualités de ces matériaux intensément mises à profit dans des activités diverses, domestiques, artisanales et manifestement aussi d’ordre symbolique, de telle sorte que le gisement châtelperronien était tout de rouge et noir. [less ▲]

Detailed reference viewed: 31 (4 ULg)
Full Text
Peer Reviewed
See detailLa richesse du sensible: Stumpf contre les néokantiens
Dewalque, Arnaud ULg

in Calori, François; Foessel, Michael; Pradelle, Dominique (Eds.) De la Sensibilité: les Esthétiques de Kant (in press)

Me focalisant sur la réception de l'esthétique transcendantale de Kant en Allemagne à la fin du XIXe et au début du XXe siècle, je confronte deux lectures concurrentes du kantisme: la lecture ... [more ▼]

Me focalisant sur la réception de l'esthétique transcendantale de Kant en Allemagne à la fin du XIXe et au début du XXe siècle, je confronte deux lectures concurrentes du kantisme: la lecture "déflationiste" des néokantiens, qui aboutit à une conception appauvrie du sensible, et la lecture "inflationiste" de Stumpf, qui fait du sensible un champ richement et intrinsèquement structuré. [less ▲]

Detailed reference viewed: 103 (9 ULg)
Full Text
Peer Reviewed
See detailJules Destrée animateur de la vie littéraire
Dozo, Björn-Olav ULg

in Institut Destrée (Ed.) Centenaire de la Lettre au Roi de Jules Destrée (in press)

Detailed reference viewed: 20 (5 ULg)
Full Text
Peer Reviewed
See detailAlgorithmic and Computational Advances for Fast Power System Dynamic Simulations
Aristidou, Petros ULg; Van Cutsem, Thierry ULg

in Proceedings of the IEEE PES General Meeting (in press)

In this paper, some algorithmic and computational advances are presented for power system dynamic simulations. The heart is a Schur-complement-based solution algorithm, stemming from domain decomposition ... [more ▼]

In this paper, some algorithmic and computational advances are presented for power system dynamic simulations. The heart is a Schur-complement-based solution algorithm, stemming from domain decomposition methods, applied to the differential-algebraic equation model. This algorithm is then accelerated computationally, by employing parallel computing techniques, and numerically, by exploiting time-scale decomposition and localization. Models of a real medium-scale system and a realistic large-scale test system are used for the performance evaluation of the proposed methods. [less ▲]

Detailed reference viewed: 50 (17 ULg)
Full Text
Peer Reviewed
See detailChronos et la clé du temps
Désert, Jean-Benoît ULg; Charon, valérie; Triffaux, Jean-Marc ULg

in Revue des Hôpitaux de Jour Psychiatriques et des Thérapies Institutionnelles (in press), 15(15), 79-85

L’argument de ce XLème Colloque des Hôpitaux de jour psychiatriques nous a plongés dans un abîme de questionnements théoriques et pratiques. Défiés par cette immersion dans les tréfonds du modèle, nous ... [more ▼]

L’argument de ce XLème Colloque des Hôpitaux de jour psychiatriques nous a plongés dans un abîme de questionnements théoriques et pratiques. Défiés par cette immersion dans les tréfonds du modèle, nous avons choisi de nous accrocher aux fondements de notre univers. La mythologie grecque sera donc notre source d’inspiration en mettant un dieu antique à notre disposition. Chronos sera notre guide dans un périple réflexif soumettant nos théories et notre pratique à l’épreuve du temps. Le récit de la conception d’un atelier thérapeutique, l’atelier « Art & Temps », sera notre fil d’Ariane dans notre tentative de symboliser notre pratique thérapeutique quotidienne et ses enjeux. Par la suite, l’exposé d’un cas clinique concrétisera un raisonnement théorique visant à situer notre modèle de prise en charge dans le réseau psychiatrique global. [less ▲]

Detailed reference viewed: 95 (10 ULg)
Full Text
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 ▲]

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailVers une généralisation des quartiers durables ? Présentation du référentiel d’aide à la conception et à l’évaluation développé en Wallonie et analyse prospective de douze quartiers.
Marique, Anne-Françoise ULg; Delbar, Caroline; Loiseau, Véronique ULg et al

in Urbia (2015)

Un référentiel a été développé en Wallonie, à la demande du Ministre de l’Environnement, de l’Aménagement du Territoire et de la Mobilité, pour opérationnaliser le concept de « quartier durable » en ... [more ▼]

Un référentiel a été développé en Wallonie, à la demande du Ministre de l’Environnement, de l’Aménagement du Territoire et de la Mobilité, pour opérationnaliser le concept de « quartier durable » en objectivant les critères minimum à respecter pour inscrire un quartier dans une vision transversale de développement durable. Ce référentiel constitue un cadre général qui régira les projets de quartiers durables menés en Wallonie (Belgique). Les 5 thématiques et les 25 critères qui constituent ce référentiel sont présentés. La grille de critères est ensuite appliquée à douze quartiers de façon à identifier les invariants communs aux processus de conception de ces quartiers et les freins à l’intégration des principes transversaux du développement durable dans les opérations de ce type. Si les critères relatifs aux performances énergétiques des bâtiments ont percolé dans un grand nombre de cas, la mixité des logements et leur accessibilité, la mixité sociale et la participation restent peu abordés. Le référentiel est disponible depuis début 2014 pour tous les acteurs de l’architecture et de l’urbanisme. [less ▲]

Detailed reference viewed: 47 (7 ULg)
Full Text
Peer Reviewed
See detailQuantitative temperature monitoring of a heat tracing experiment using cross-borehole ERT
Hermans, Thomas ULg; Wildemeersch, Samuel ULg; Jamin, Pierre ULg et al

in Geothermics (2015), 53

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal ... [more ▼]

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal systems requires a multidisciplinary approach including geological and hydrogeological aspects. In this context, electrical resistivity tomography (ERT) can bring relevant, qualitative and quantitative information on the temperature distribution in operating shallow geothermal systems or during heat tracing experiments. We followed a heat tracing experiment in an alluvial aquifer using cross-borehole time-lapse ERT. Heated water was injected in a well while water of the aquifer was extracted at another well. An ERT section was set up across the main flow direction. The results of ERT were transformed into temperature using calibrated petrophysical relationships. These ERT-derived temperatures were then compared to direct temperature measurements in control piezometers collected with distributed temperature sensing (DTS) and groundwater temperature loggers. Spatially, it enabled to map the horizontal and vertical extent of the heated water plume, as well as the zones where maximum temperatures occurred. Quantitatively, the temperatures and breakthrough curves estimated from ERT were in good agreement with the ones observed directly during the rise and maximum of the curve. An overestimation, likely related to 3D effects, was observed for the tail of the heat breakthrough curve. The error made on temperature can be estimated to be between 10 to 20 %, which is a fair value for indirect measurements. From our data, we estimated a quantification threshold for temperature variation of 1.2°C. These results suggest that ERT should be considered when designing heat tracing experiments or geothermal systems. It could help also to assess the geometrical complexity of the concerned reservoirs. It also appears that ERT could be a useful tool to monitor and control geothermal systems once they are in operation. [less ▲]

Detailed reference viewed: 42 (24 ULg)
Full Text
Peer Reviewed
See detailSur les définitions de Dieu. Entretien avec Valère Novarina
Dubouclez, Olivier ULg; Novarina, Valère

in Littérature (2014)

Detailed reference viewed: 22 (1 ULg)
Full Text
See detailUnderstanding Random Forests: From Theory to Practice
Louppe, Gilles ULg

Doctoral thesis (2014)

Data analysis and machine learning have become an integrative part of the modern scientific methodology, offering automated procedures for the prediction of a phenomenon based on past observations ... [more ▼]

Data analysis and machine learning have become an integrative part of the modern scientific methodology, offering automated procedures for the prediction of a phenomenon based on past observations, unraveling underlying patterns in data and providing insights about the problem. Yet, caution should avoid using machine learning as a black-box tool, but rather consider it as a methodology, with a rational thought process that is entirely dependent on the problem under study. In particular, the use of algorithms should ideally require a reasonable understanding of their mechanisms, properties and limitations, in order to better apprehend and interpret their results. Accordingly, the goal of this thesis is to provide an in-depth analysis of random forests, consistently calling into question each and every part of the algorithm, in order to shed new light on its learning capabilities, inner workings and interpretability. The first part of this work studies the induction of decision trees and the construction of ensembles of randomized trees, motivating their design and purpose whenever possible. Our contributions follow with an original complexity analysis of random forests, showing their good computational performance and scalability, along with an in-depth discussion of their implementation details, as contributed within Scikit-Learn. In the second part of this work, we analyze and discuss the interpretability of random forests in the eyes of variable importance measures. The core of our contributions rests in the theoretical characterization of the Mean Decrease of Impurity variable importance measure, from which we prove and derive some of its properties in the case of multiway totally randomized trees and in asymptotic conditions. In consequence of this work, our analysis demonstrates that variable importances as computed from non-totally randomized trees (e.g., standard Random Forest) suffer from a combination of defects, due to masking effects, misestimations of node impurity or due to the binary structure of decision trees. Finally, the last part of this dissertation addresses limitations of random forests in the context of large datasets. Through extensive experiments, we show that subsampling both samples and features simultaneously provides on par performance while lowering at the same time the memory requirements. Overall this paradigm highlights an intriguing practical fact: there is often no need to build single models over immensely large datasets. Good performance can often be achieved by building models on (very) small random parts of the data and then combining them all in an ensemble, thereby avoiding all practical burdens of making large data fit into memory. [less ▲]

Detailed reference viewed: 4391 (31 ULg)
Full Text
Peer Reviewed
See detailPrevenção Quaternária e limites em medicina
Jamoulle, Marc ULg; Gomes, Luis

in Revista Brasileira de Medicina de Família e Comunidade (2014), 9(31),

O conceito de Prevenção Quaternária, um questionamento sobre a base da ação médica, nasceu na articulação da relação médico-paciente. Refere-se a toda a atividade médica, sendo uma importante ferramenta ... [more ▼]

O conceito de Prevenção Quaternária, um questionamento sobre a base da ação médica, nasceu na articulação da relação médico-paciente. Refere-se a toda a atividade médica, sendo uma importante ferramenta para a medicina de família. É uma interrogação ética sobre os excessos da demasiada e demasiadamente pouca medicina e fornece algumas respostas. [less ▲]

Detailed reference viewed: 8 (0 ULg)
Full Text
See detail9th Congress of the International Society of NeuroImmunoModulation (ISNIM)
Geenen, Vincent ULg

Scientific conference (2014, September 25)

Detailed reference viewed: 51 (2 ULg)
Full Text
Peer Reviewed
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)

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 13 (4 ULg)
Full Text
Peer Reviewed
See detailElastic damage to crack transition in a coupled non-local implicit discontinuous Galerkin/extrinsic cohesive law framework
Wu, Ling ULg; Becker, Gauthier ULg; Noels, Ludovic ULg

in Computer Methods in Applied Mechanics & Engineering (2014), 279

One current challenge related to computational fracture mechanics is the modeling of ductile fracture and in particular the damage to crack transition. On the one hand, continuum damage models, especially ... [more ▼]

One current challenge related to computational fracture mechanics is the modeling of ductile fracture and in particular the damage to crack transition. On the one hand, continuum damage models, especially in their non-local formulation which avoids the loss of solution uniqueness, can capture the material degradation process up to the localization of the damage, but are unable to represent a discontinuity in the structure. On the other hand cohesive zone methods can represent the process zone at the crack tip governing the crack propagation, but cannot account for the diffuse material damaging process. In this paper we propose to combine, in a small deformations setting, a non-local elastic damage model with a cohesive zone model. This combination is formulated within a discontinuous Galerkin nite element discretization. Indeed this DG weak formulation can easily be developed in a non-local implicit form and naturally embeds interface elements that can be used to integrate the traction separation law of the cohesive zone model. The method remains thus consistent and computationally e cient as compared to other cohesive element approaches. The effects of the damage to crack transition and of the mesh discretization are respectively studied on the compact tension specimen and on the double-notched specimen, demonstrating the efficiency and accuracy of the method. [less ▲]

Detailed reference viewed: 25 (4 ULg)
Full Text
Peer Reviewed
See detailComentário sobre o artigo de Pizzanelli
Jamoulle, Marc ULg

in Revista Brasileira de Medicina de Família e Comunidade (2014), 9(31),

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailAutonomie de la volonté et concurrence régulatoire – le cas des relations familiales internationales
Wautelet, Patrick ULg

in Fulchiron, Hugues; Bergé, Jean-Sylvestre (Eds.) Vers un statut européen de la famille ? (2014)

L'autonomie de la volonté a connu un essor considérable dans le règlement des relations familiales internationales. Au-delà de la consécration toujours plus importante de l'autonomie de la volonté comme ... [more ▼]

L'autonomie de la volonté a connu un essor considérable dans le règlement des relations familiales internationales. Au-delà de la consécration toujours plus importante de l'autonomie de la volonté comme fondement de la règle de conflit de lois en matière familiale, la liberté des parties a reçu ces dernières années un appui important par le biais d'une jurisprudence ambitieuse tant de la Cour de justice de l'Union que de la Cour européenne des droits de l'homme. Dans le même temps, force est bien de constater que le droit de la famille semble constituer un îlot de résistance tenace face au mouvement d'unification et d'harmonisation. Les ingrédients semblent dès lors réunis pour le développement d'une véritable concurrence législative qui pourrait mener au spectre de la 'race to the bottom'. A l'offre de droits aux contenus différents se conjuge en effet une certaine possibilité de choix par les parties. Cette liberté de choix constitue un avatar évident de la mobilité qui fonde le pouvoir d'arbitrage des acteurs privés. La présente contribution a pour objectif de s'interroger sur l'existence réelle d'une telle concurrence normative. [less ▲]

Detailed reference viewed: 19 (1 ULg)
Full Text
See detailInteractions in massive binaries: spectral modelling – CoMBiSpeC – and observational analyses
Palate, Matthieu ULg

Doctoral thesis (2014)

Massive stars are very important to the life of the galaxiesbut they are rare and many open questions on their formation, evolution and characteristics remain. One of the best ways to improve our ... [more ▼]

Massive stars are very important to the life of the galaxiesbut they are rare and many open questions on their formation, evolution and characteristics remain. One of the best ways to improve our knowledge on massive stars is to study massive binaries (that represent at least 50% of massive stars see Mahy et al. 2009, and Sana & Evans 2011) and their spectra. Spectral and atmosphere modelling of stars are very interesting tools that are now often used in spectral analyses. However, these models are designed for single spherical stars. In this context, we have developed a numerical code of spectral modelling of massive binary systems: CoMBiSpeC (code of massive binary spectral computation) that computes the spectra of massive binary systems and accounts for various effects that affect these systems. Our models, and the observational analyses of the four binary systems presented in the second part of this work, have allowed to explain several effects linked to binarity: luminosity class discrepancy, temperature distribution, Struve-Sahade effect, and some kind of line profile variations. In summary, CoMBiSpeC is a first step in the spectral modelling of massive binary systems and several improvements are still needed to be able to study all massive binaries. Nevertheless, this model can explain and reproduce various observed phenomena which was the main goal of this thesis. [less ▲]

Detailed reference viewed: 16 (7 ULg)