References of "Paper published in a book"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailA wavelet leaders-based climate classification of European surface air temperature signals
Deliège, Adrien ULg; Nicolay, Samuel ULg

in Ruiz Garcia, Gonzalo; Rojas Ruiz, Ignacio (Eds.) Proceedings of the International work-conference on Time Series: Volume 1, Granada 25-27 June 2014 (2014, June 25)

We explain the wavelet leaders method, a tool to study the pointwise regularity of signals, which is closely related to some functional spaces. We use the associated multifractal formalism to show that ... [more ▼]

We explain the wavelet leaders method, a tool to study the pointwise regularity of signals, which is closely related to some functional spaces. We use the associated multifractal formalism to show that surface air temperature signals are monofractal, i.e. these climate time series are regularly irregular. Then we use this result to establish a climate classification of weather stations in Europe which matches the Köppen-Geiger climate classification. This result could give rise to new criteria to determine the efficiency of current climatic models. [less ▲]

Detailed reference viewed: 29 (5 ULg)
Full Text
Peer Reviewed
See detailSPATIODATA, un modèle de bâtiment non-constructif, collaboratif et multi-usage
Delfosse, Vincent ULg; Boulanger, Christelle ULg; Jeunejean, Aurélie ULg et al

in Actes du 6ème Séminaire de Conception Architecturale Numérique (2014, June 19)

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a ... [more ▼]

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a collaborative platform for the effective sharing of building-related data and supporting a wide range of different activities. This paper discusses the specific data model at the heart of the project. A comparison with the traditional BIM models is given in order to motivate the choices made in this project. [less ▲]

Detailed reference viewed: 31 (7 ULg)
Full Text
Peer Reviewed
See detailExperimental tests and numerical modelling on eight slender steel columns under increasing temperatures
Franssen, Jean-Marc ULg; Zhao, Bin; Gernay, Thomas ULg

in Li, G.Q.; Jiang, S.C.; Chen, Suwen (Eds.) et al Progress on Safety of Structures in Fire (2014, June 11)

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental ... [more ▼]

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental testing, parametric numerical analyses and development of simple design rules. The present paper reports the characteristics and the results of the FIDESC4 experimental test campaign performed at the University of Liege on slender steel columns at elevated temperatures. A total of eight columns have been tested, all of them with I shape section. Six columns were made of welded sections (some prismatic and some tapered members) and two columns were with hot rolled sections. The nominal length of the columns was 3 meters with the whole length being heated. The strength of the material (webs and flanges) was measured on sample before the tests. The order of magnitude of the initial geometrical imperfections was recorded. The columns were not restrained against longitudinal thermal elongation. The supports at the ends were cylindrical thus inducing a restrain against rotation in one plane while allowing rotation in the other plane. The allowed direction of rotation was chosen in each test to induce buckling around the strong or the weak axis. The load was applied at ambient temperature and maintained for a period of 15 minutes after which the temperature was increased under constant load. The load was applied concentrically on some tests and with an eccentricity in other tests. The load eccentricity was either applied at both ends, leading to constant bending moment distribution along the length, or at one end only, leading to a triangular bending moment distribution. Heating was applied by electrical resistances enclosed in ceramic pads. The columns and the ceramic pads were wrapped in ceramic wool insulating material. This technique was preferred to gas heating in a standard test furnace because it allows applying a slower and better controlled heating rate and thus obtaining a more uniform temperature distribution in the member. It is also easier to measured lateral displacements of the column. Preliminary blank tests were performed on unloaded specimen in order to determine the heating range to be used later on the loaded columns. The paper will also report on a modification of the heating technique that was applied and improved significantly the uniformity in the temperature distribution. Numerical simulations were performed before the tests using shell elements of the software SAFIR and assumed values of the material properties in order to predict the failure modes. It was essentially crucial to determine whether lateral supports at intermediate levels should be provided in order to ensure failure in the desired direction. Experience showed that the failure modes developed as predicted by the numerical simulations. Besides a thorough description of the experiments, the paper will also present the obtained results in terms of failure mode, ultimate temperature and evolution of longitudinal and transverse displacement. Some information will also be given about the level of detail that has to be used in the numerical model in order to get accurate results at a reasonable price. [less ▲]

Detailed reference viewed: 104 (14 ULg)
Peer Reviewed
See detailLe sort des travailleurs d’une entreprise en réorganisation judiciaire
Kéfer, Fabienne ULg; Gailliet, Guillaume ULg

in Clesse, Jacques (Ed.) Questions choisies de droit social. Hommage à Michel Dumont (2014, June 06)

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la ... [more ▼]

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la dégradation de la situation des travailleurs. Le complexe normatif étudié reflète le point actuel du rapport de force entre le monde économique et les syndicats. Les salariés sont, en définitive, amenés à faire une grande partie du sacrifice nécessaire pour atteindre l’objectif économique recherché. Ce constat est perceptible dans l’hypothèse d’une réorganisation par accord collectif et dans celle du transfert sous autorité de justice, qui témoignent des rapports complexes entre les intérêts économiques et sociaux. La conciliation de ces intérêts divergents s’effectue sous la surveillance du juge. [less ▲]

Detailed reference viewed: 36 (7 ULg)
Full Text
Peer Reviewed
See detailOn-the-fly domain adaptation of binary classifiers
Pierard, Sébastien ULg; Marcos Alvarez, Alejandro ULg; Lejeune, Antoine ULg et al

in 23rd Belgian-Dutch Conference on Machine Learning (BENELEARN) (2014, June 06)

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to ... [more ▼]

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to negative and positive classes are supposed to be mixtures of the source distributions. Moreover, the mixture weights and the priors are only available at runtime. We present a theoretical solution to this problem, and demonstrate the effectiveness of the proposed approach on a real computer vision application. Our theoretical solution is applicable to any classifier approximating Bayes' classifier. [less ▲]

Detailed reference viewed: 60 (13 ULg)
Full Text
Peer Reviewed
See detailLa psychopathologie à la lumière des histoires de vie : Etude de la fonction narrative d’adolescents obèses et dépressifs.
Jadin, Aurore ULg; Gauthier, Jean-Marie ULg; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-Actes des 12èmes journées internationales d'analyse statistique de données textuelles (2014, June 05)

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these ... [more ▼]

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these youngs (High Authority of Health, 2011; Nietsen and Bruwier, 2007). The literature mentions depression as a pathology associated with obesity. Some researchers consider obesity as a cause of depressive symptoms while others researchers see depression like a risk factor for excessive weight gain (Blaine, 2008). Depression in adolescence has been the subject of epidemiological studies for some years. In adolescents, the prevalence rates vary from 5 to 7 % for major depressive episode (MDE) with a prevalence of 2 girls for one boy (Alvin and Marcelli, 2005). The specific symptoms of depressed mood are present in 30-40 % of schooled adolescents (Boulard et al., 2012). During adolescence, the individual acquires the ability to link the various elements of one’s life and build a coherent life story. The adolescent will write one’s story in a personal context. According to Habermas et al. (2008), both the form and the content of life stories show how the individual integrates the lived experiences in a coherent whole. Based on the statistical analysis of textual data, we compared the life stories of 28 obese adolescents, depressed schooled adolescents, depressed hospitalized adolescents and control ones. The first results show specific structures and particular contents depending on these groups. The use of pronouns, temporal markers and the reported events differ by groups. Beyond clinical results, this research also highlights the interest of statistical analysis of textual data (ADT) to improve the understanding of adolescent’s psychopathology. [less ▲]

Detailed reference viewed: 61 (20 ULg)
Full Text
Peer Reviewed
See detailExploration du récit de vie d’adolescents
Poudat, Céline; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-actes des 12èmes journées d'analyse statistique de données textuelles (2014, June 05)

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in ... [more ▼]

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in children and adolescents. Although children develop narrative skills, life narratives only emerge in adolescence. On the basis of a corpus made of spontaneous oral speech, we had empirically demonstrated that pre-adolescents aged of 12 had developed stabilized narrative skills enabling them to produce life narratives. Here, we propose a first exploration of the overall structure of adolescent life stories, thanks to a corpus of 268 oral self narratives completed with a questionnaire. [less ▲]

Detailed reference viewed: 22 (11 ULg)
Full Text
Peer Reviewed
See detailSIMPLIFIED SEISMIC ANALYSIS OF LOCK GATES
Buldgen, Loïc ULg; Degée, Hervé ULg; Lesourne, Hervé et al

in PIANC 2014 Conference (2014, June 02)

The paper deals with the seismic design of lock gates. When such structures are submitted to an earthquake, the water contained in the chamber is responsible for an additional hydrodynamic pressure acting ... [more ▼]

The paper deals with the seismic design of lock gates. When such structures are submitted to an earthquake, the water contained in the chamber is responsible for an additional hydrodynamic pressure acting on the gate. This one is the sum of three different parts, respectively called the convective, rigid and flexible contributions. The two first ones have already been extensively studied in the literature, but the flexible part is more difficult to assess as it is largely influenced by the coupling occurring between the fluid and the gate. To overcome this difficulty, it is of course possible to use finite elements software, but doing so is not always convenient. This is why some research have been undertaken to provide a rapid way for approximating the flexible pressure on lock gates. This is achieved by applying the analytical approach that is shortly presented in this paper. As a matter of validation, the results obtained through this simplified procedure are compared to numerical solutions. The agreement between both of them is found to be satisfactory. [less ▲]

Detailed reference viewed: 29 (9 ULg)
See detailRay tracing enhancement for space thermal analysis: isocell method
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Sarler, Bozidar; Massaroti, Nicola; Nithiarasu, Perumal (Eds.) Third International Conference on Computational Methods for Thermal Problems (2014, June 02)

The finite element method (FEM) is widely used in mechanical engineering, especially for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the ... [more ▼]

The finite element method (FEM) is widely used in mechanical engineering, especially for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the lumped parameter method is still dominant. Radiative exchange factors (REFs) are usually computed through Monte Carlo ray-tracing. Due to the large number of elements composing a FE model, the computation of the REFs is prohibitively expensive. The developments of the new Isocell quasi-Monte Carlo ray tracing method are presented. The Isocell method enhances the uniformity of the generated quasi-random sequence of ray directions and leads to faster convergence. It is associated with different surface sampling to derive the REFs. The method is benchmarked against ESARAD, the standard ray-tracing engine for thermal analysis used in the European aerospace industry. Various geometries are used. In particular, one entrance baffle of the Extreme Ultraviolet Imager (EUI) instrument developed at the Centre Spatial de Liège in Belgium is used. The EUI instrument of the Solar Orbiter European Space Agency mission and will be launched in a Sun-centered 0.28 perihelion orbit in 2018. [less ▲]

Detailed reference viewed: 22 (5 ULg)
Full Text
Peer Reviewed
See detailDe la matière à l'espace: une voie d'intégration numérique et matérielle
Delvaux, Frederic ULg; Bianchi, Romuald ULg; Jancart, Sylvie ULg

in Kubicki, Sylvain; Halin, Gilles; Bignon, Jean-CLaude (Eds.) Scan 14 séminaire de conception architecturale numérique : Interaction(s) des maquettes numériques (2014, June 01)

From a collaboration of formal and architectural research between architect and artist, we present the summary of an experimental approach that illustrates the creation and construction of a functional ... [more ▼]

From a collaboration of formal and architectural research between architect and artist, we present the summary of an experimental approach that illustrates the creation and construction of a functional space, located at the borders of the sculpture and the architecture. We present a look at the method, according to a revised approach to digital modeling / re-design. This has been an exploratory approach through the study of three generic models of the form. We present the experimental method, the selection of relevant parameters in form finding coupled with the integration of material and physical data specific to the object. We also expose the benefits of this approach, its limitations and the possibilities it offers as a generic point of view. [less ▲]

Detailed reference viewed: 31 (11 ULg)
Full Text
Peer Reviewed
See detailAn Investigation into the Influence of External Walls Reflectivity on the Indoor Daylight Availability in Desert Climates
Hegazy, Mohamed Amer; Attia, Shady ULg

in Conference Proceedings: Building Simulation and Optimization 2014 (2014, June)

Hot arid climates are characterized by clear sunny sky most of the year time. Such climates affects the urban morphology, which requires sometimes dense urban fabric. Narrow streets have significant ... [more ▼]

Hot arid climates are characterized by clear sunny sky most of the year time. Such climates affects the urban morphology, which requires sometimes dense urban fabric. Narrow streets have significant effect on the amount of daylight permeating indoor residential zones, which may have a negative or positive effect on the overall visual performance. This paper studies the quantitative effect of using different Façade reflectivity ratios, under different street widths, on the indoor daylight autonomy. The researcher performed a parametric analysis using DIVA for Rhino simulation tool on a hypothetical residential building unit with various window ratios facing neighbouring buildings. Four main orientations were examined under different urban contexts and wall reflectivity. This paper aims to measure daylight autonomy and address possible strategies and solutions to achieve better daylighting that can be used by architects at early design stages of housing developments in the desert climates. [less ▲]

Detailed reference viewed: 87 (3 ULg)
Full Text
Peer Reviewed
See detailCHARACTERIZATION OF PROTEINURIA IN DOGUE DE BORDEAUX DOGS USING ELECTROPHORESIS AND URINARY BIOMARKERS
Lavoué, Rachel; Smets, P.; Trumel, Cathy et al

in Proceedings of the 2014 ACVIM Forum (2014, June)

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailUsing intensive multiyear fish-pass monitoring to analyse seasonal upstream movement patterns of patrimonial holobiotic potomadromous fish species in a medium size river
Benitez, Jean-Philippe ULg; Nzau Matondo, Billy ULg; Dierckx, Arnaud ULg et al

in Proceedings of the 10th International Conference on Ecohydraulics (2014, June)

Belgian rivers are fragmented by numerous obstacles which considerably limit the free access of fish to functional habitats. Fish-passes are major tools used to increase stream continuity and improve ... [more ▼]

Belgian rivers are fragmented by numerous obstacles which considerably limit the free access of fish to functional habitats. Fish-passes are major tools used to increase stream continuity and improve connectivity in the upstream direction. Using two modern multispecies fish-passes, this study aims to investigate multiyear abundance of holobiotic potamodromous fish and their seasonal movement patterns in relation with environmental factors. The fish passes were monitored continuously during 5 and 7 years and are located in two Belgian streams: the (19.3m³.s-1) and the Berwinne (1.9m³.s-1). Results revealed the presence of 20 different fish species, 14 species in the Berwinne and 19 species in the occurrence, salmonids and cyprinids species were predominant. A great interspecific and intraspecific variability in capture periodicity and in terms of stimulation by combination of factor environmental was observed. This study highlights the complexity and the omnipresence of holobiotic potamodromous fish movements at different life stages, in medium size river and brings new information on fish passes efficiency and use by these poorly known species. [less ▲]

Detailed reference viewed: 28 (9 ULg)
Full Text
Peer Reviewed
See detailBayes Adaptive Reinforcement Learning versus Off-line Prior-based Policy Search: an Empirical Comparison
Castronovo, Michaël ULg; Ernst, Damien ULg; Fonteneau, Raphaël ULg

in Proceedings of the 23rd annual machine learning conference of Belgium and the Netherlands (BENELEARN 2014) (2014, June)

This paper addresses the problem of decision making in unknown finite Markov decision processes (MDPs). The uncertainty about the MDPs is modeled using a prior distribution over a set of candidate MDPs ... [more ▼]

This paper addresses the problem of decision making in unknown finite Markov decision processes (MDPs). The uncertainty about the MDPs is modeled using a prior distribution over a set of candidate MDPs. The performance criterion is the expected sum of discounted rewards collected over an infinite length trajectory. Time constraints are defined as follows: (i) an off-line phase with a given time budget can be used to exploit the prior distribution and (ii) at every time step of the on-line phase, decisions have to be computed within a given time budget. In this setting, we compare two decision-making strategies: OPPS, a recently proposed meta-learning scheme which mainly exploits the off-line phase to perform policy search and BAMCP, a state-of-the-art model-based Bayesian reinforcement learning algorithm, which mainly exploits the on-line time budget. We empirically compare these approaches in a real Bayesian setting by computing their performances over a large set of problems. To the best of our knowledge, it is the first time that this is done in the reinforcement learning literature. Several settings are considered by varying the prior distribution and the distribution from which test problems are drawn. The main finding of these experiments is that there may be a significant benefit of having an off-line prior-based optimization phase in the case of informative and accurate priors, especially when on-line time constraints are tight. [less ▲]

Detailed reference viewed: 135 (56 ULg)
Full Text
Peer Reviewed
See detailDistributed Model-free Control of Photovoltaic Units for Mitigating Overvoltages in Low-Voltage Networks
Aristidou, Petros ULg; Olivier, Frédéric ULg; Hervas, Maria Emilia et al

in Proc. of CIRED 2014 workshop (2014, June)

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are ... [more ▼]

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are implemented on the photovoltaic inverters and modulate the active and reactive power injected into the network. In particular, they direct photovoltaic units first to consume reactive power and, if necessary, curtail active power generation to reduce high voltages in the feeder. [less ▲]

Detailed reference viewed: 99 (32 ULg)
Full Text
See detailReceptor expression in craniopharyngiomas causing tumor growth in pregnancy: case report and review of the literature
VROONEN, Laurent ULg; TOME, Monica; THIRY, Albert ULg et al

in Abstract book : 57èmes Journées Internationales d'Endocrinologie Clinique - Henri-Pierre Klotz (2014, June)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailGeometric parameters influence on Piano Key Weir hydraulic performances
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Pirotton, Michel ULg et al

in Chanson, Hubert; Toombes, Luke (Eds.) Hydraulic Structures and Society – Engineering Challenges (2014, June)

The Piano Key Weir is a recent evolution of the traditional labyrinth weir. Thanks to a reduced foot print, this nonlinear weir can be placed on the top of gravity dams. The Piano Key Weir geometry ... [more ▼]

The Piano Key Weir is a recent evolution of the traditional labyrinth weir. Thanks to a reduced foot print, this nonlinear weir can be placed on the top of gravity dams. The Piano Key Weir geometry involves a large number of geometric parameters. Several experimental studies have been carried out to investigate the main geometric parameters influencing the weir hydraulic efficiency and to define their optimal value. In this paper, the experimental data gathered at the University of Liege are re-examined to show how the weir height, the keys widths and the overhangs positions influence, for a given crest length magnification ratio, the weir discharge capacity. The theoretical rating curve of a standard linear weir is considered for comparison. The analysis highlights that the keys widths and overhangs lengths ratios influence significantly the Piano Key Weir efficiency, but less than the weir height. Considering the above mentioned results, a cost efficient design proposed in the literature is also proved to be close to the hydraulic optimum. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailThe grassland model intercomparison of the MACSUR (Modelling European Agriculture with Climate Change for Food Security) European knowledge hub
Ma, Shaoxiu; Acutis, Marco; Barcza, Zoltan et al

in Proceedings of the 7th International Congress on Environmental Modelling and Software (iEMSs) June 15-19, 2014, San Diego, California, USA (2014, June)

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailOn the Quality of BGP Route Collectors for iBGP Policy Inference
Cittadini, Luca; Vissicchio, Stefano; Donnet, Benoît ULg

in IFIP Networking (2014, June)

A significant portion of what is known about Internet routing stems out from public BGP datasets. For this reason, numerous research efforts were devoted to (i) assessing the (in)completeness of the ... [more ▼]

A significant portion of what is known about Internet routing stems out from public BGP datasets. For this reason, numerous research efforts were devoted to (i) assessing the (in)completeness of the datasets, (ii) identifying biases in the dataset, and (iii) augmenting data quality by optimally placing new collectors. However, those studies focused on techniques to extract information about the AS-level Internet topology. In this paper, we show that considering different metrics influences the conclusions about biases and collector placement. Namely, we compare AS-level topology discovery with \iac inference. We find that the same datasets exhibit significantly diverse biases for these two metrics. For example, the sensitivity to the number and position of collectors is noticeably different. Moreover, for both metrics, the marginal utility of adding a new collector is strongly localized with respect to the proximity of the collector. Our results suggest that the ``optimal'' position for new collectors can only be defined with respect to a specific metric, hence posing a fundamental trade-off for maximizing the utility of extensions to the BGP data collection infrastructure. [less ▲]

Detailed reference viewed: 68 (15 ULg)
Full Text
Peer Reviewed
See detailLe B.I.M et la maquette virtuelle comme moyen pédagogique permettant le rapprochement entre les cours d'informatique et l'enseignement du projet d'architecture
Boutemadja, Abdelkader ULg; Driesmans, Carine ULg; Jancart, Sylvie ULg

in Kubicki, Sylvain; Halin, Gilles; Bignon, Jean-Claude (Eds.) Scan 14 sémainaire de conception architecturale numérique : Interaction(s) des maquettes numériques (2014, June)

In the context of this paper, we pose the question of the conditions of possible link between computer courses and design projet. The integration of schools of architecture at universities is an ... [more ▼]

In the context of this paper, we pose the question of the conditions of possible link between computer courses and design projet. The integration of schools of architecture at universities is an opportunity to focus in the experiments made in this direction and to propose to implement the terms of this rapprochement. For us, it is important that this approach lies in the Bachelor years in a common core for all students. [less ▲]

Detailed reference viewed: 36 (4 ULg)
Full Text
Peer Reviewed
See detailMODEL PREDICTIVE CONTROL OF CONGESTION AND VOLTAGE PROBLEMS IN ACTIVE DISTRIBUTION NETWORKS
Soleimani Bidgoli, Hamid ULg; Glavic, Mevludin ULg; Van Cutsem, Thierry ULg

in Proc. of CIRED Workshop 2014 (2014, June)

This paper presents a centralized control scheme, inspired of Model Predictive Control (MPC), to manage thermal overloads and correct abnormal voltages in real-time. The control scheme is able to smoothly ... [more ▼]

This paper presents a centralized control scheme, inspired of Model Predictive Control (MPC), to manage thermal overloads and correct abnormal voltages in real-time. The control scheme is able to smoothly bring the system within the desired limits, taking into account its near-future evolution. The control method effectiveness is illustrated on a 20-kV, 32-bus network hosting four distributed generation units. [less ▲]

Detailed reference viewed: 91 (27 ULg)
Full Text
Peer Reviewed
See detailThe Call for project proposals « Let’s live my village »: between free interpretations and compulsory readings regarding innovation and convivial village ambiance in Wallonia.
Schmitz, Serge ULg

in Les campagnes: espaces d'innovation dans un monde urbain (2014, June)

The paper scrutinizes 186 rural development projects selected on the short list of the first and second “Lets’ live my village!” calls. It examines trends concerning rural community life and the identity ... [more ▼]

The paper scrutinizes 186 rural development projects selected on the short list of the first and second “Lets’ live my village!” calls. It examines trends concerning rural community life and the identity of the leaders/brokers. It pays attention to the way that associations define rurality. Question 14 of the application form « Does your association act in rural areas? Explain” is the main source of information for content analysis and contingency tables [less ▲]

Detailed reference viewed: 26 (10 ULg)
Full Text
Peer Reviewed
See detailOn the Performance of the LISP Beta Network
Coras, Florin; Saucez, Damien; Iannone, Luigi et al

in IFIP Networking (2014, June)

The future Internet has been a hot topic during the past decade and many approaches towards this future Internet, ranging from incremental evolution to complete clean slate ones, have been proposed. One ... [more ▼]

The future Internet has been a hot topic during the past decade and many approaches towards this future Internet, ranging from incremental evolution to complete clean slate ones, have been proposed. One of the proposition, LISP, advocates for the separation of the identifier and the locator roles of IP addresses to reduce BGP churn and BGP table size. Up to now, however, most studies concerning LISP have been theoretical and, in fact, little is known about the actual LISP deployment performance. In this paper, we fill this gap through measurement campaigns carried out on the LISP Beta Network. More precisely, we evaluate the performance of the two key components of the infrastructure: the control plane (i.e., the mapping system) and the interworking mechanism (i.e., communication between LISP and non-LISP sites). Our measurements highlight that performance offered by the LISP interworking infrastructure is strongly dependent on BGP routing policies. If we exclude misconfigured nodes, the mapping system typically provides reliable performance and relatively low median mapping resolution delays. Although the bias is not very important, control plane performance favors USA sites as a result of its larger LISP user base but also because European infrastructure appears to be less reliable. [less ▲]

Detailed reference viewed: 57 (10 ULg)
Full Text
Peer Reviewed
See detailArrival of european eel in Belgian Part of the Meuse: who and how are they?
Nzau Matondo, Billy ULg; Benitez, Jean-Philippe ULg; Dierckx, Arnaud ULg et al

in Proceedings of the 10th International Conference on Ecohydraulics (2014, June)

Detailed reference viewed: 27 (8 ULg)
Full Text
Peer Reviewed
See detailÉtude des changements de circulation au-dessus de l'océan Austral en été
Belleflamme, Alexandre ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

in Camberlin, Pierre; Richard, Yves (Eds.) Actes du XXVIIème colloque de l'Association de Climatologie - Climat : système & interactions (2014, June)

Over the five last decades, the reanalyses (ERA and NCEP/NCAR) show a strengthening of the pressure gradient between the southern hemisphere subtropical anticyclone belt and the southern circumpolar lows ... [more ▼]

Over the five last decades, the reanalyses (ERA and NCEP/NCAR) show a strengthening of the pressure gradient between the southern hemisphere subtropical anticyclone belt and the southern circumpolar lows during summer. With the help of an automatic circulation type classification, we show that the strengthening of the pressure gradient is generalised to all circulation types and, paradoxically, it does not cause circulation changes. It is probably implied by the strengthening of the temperature gradient between the tropics and the South Pole, without consequences on the general circulation. Our classification also allows a successful comparison between the two reanalyses in a region where the observation data are rare. [less ▲]

Detailed reference viewed: 20 (3 ULg)
Full Text
Peer Reviewed
See detailPrediction of macroscopic mechanical properties of a polycrystalline microbeam subjected to material uncertainties
Lucas, Vincent ULg; Wu, Ling ULg; Arnst, Maarten ULg et al

in Cunha, Álvaro; Caetano, Elsa; Ribeiro, Pedro (Eds.) et al Proceedings of the 9th International Conference on Structural Dynamics, EURODYN 2014 (2014, June)

The first resonance frequency is a key performance characteristic of MEMS vibrometers. In batch fabrication, this first resonance frequency can exhibit scatter owing to various sources of manufacturing ... [more ▼]

The first resonance frequency is a key performance characteristic of MEMS vibrometers. In batch fabrication, this first resonance frequency can exhibit scatter owing to various sources of manufacturing variability involved in the fabrication process. The aim of this work is to develop a stochastic multiscale model for predicting the first resonance frequency of MEMS microbeams constituted of polycrystals while accounting for the uncertainties in the microstructure due to the grain orientations. At the finest scale, we model the microstructure of polycrystaline materials using a random Voronoï tessellation, each grain being assigned a random orientation. Then, we apply a computational homogenization procedure on statistical volume elements to obtain a stochastic characterization of the elasticity tensor at the second scale of interest, the meso-scale. In the future, using a stochastic finite element method, we will propagate these meso-scale uncertainties to the first resonance frequency at the coarser scale. [less ▲]

Detailed reference viewed: 43 (18 ULg)
Full Text
Peer Reviewed
See detailSimple connectome inference from partial correlation statistics in calcium imaging
Sutera, Antonio ULg; Joly, Arnaud ULg; François-Lavet, Vincent ULg et al

in Proceedings of Connectomics 2014 (ECML 2014) (2014, June)

In this work, we propose a simple yet effective solution to the problem of connectome inference in calcium imaging data. The proposed algorithm consists of two steps. First, processing the raw signals to ... [more ▼]

In this work, we propose a simple yet effective solution to the problem of connectome inference in calcium imaging data. The proposed algorithm consists of two steps. First, processing the raw signals to detect neural peak activities. Second, inferring the degree of association between neurons from partial correlation statistics. This paper summarises the methodology that led us to win the Connectomics Challenge, proposes a simplified version of our method, and finally compares our results with respect to other inference methods. [less ▲]

Detailed reference viewed: 390 (113 ULg)
Full Text
Peer Reviewed
See detailAnalysis versus synthesis for trending of gas-path measurement time series
Borguet, Sébastien ULg; Léonard, Olivier ULg; Dewallef, Pierre ULg

in Proceedings of ASME Turbo Expo 2014 (2014, June)

Gas-path measurements used to assess the health condition of an engine are corrupted by noise. Generally, a data cleaning step occurs before proceeding with fault detection and isolation. Classical linear ... [more ▼]

Gas-path measurements used to assess the health condition of an engine are corrupted by noise. Generally, a data cleaning step occurs before proceeding with fault detection and isolation. Classical linear filters such as the exponentially weighted moving average filter are traditionally used for noise removal. Unfortunately, these low-pass filters distort trend shifts indicative of faults, which increases the detection delay. The present paper investigates two new approaches to non-linear filtering of time series. On one hand, the synthesis approach reconstructs the signal as a combination of elementary signals chosen from a pre-defined library. On the other hand, the analysis approach imposes a constraint on the shape of the signal (e.g., piecewise constant). Both approaches incorporate prior information about the signal in a different way, but they lead to trend filters that are very capable at noise removal while preserving at the same time sharp edges in the signal. This is highlighted through the comparison with a classical linear filter on a batch of synthetic data representative of typical engine fault profiles. [less ▲]

Detailed reference viewed: 10 (3 ULg)
Full Text
Peer Reviewed
See detailDouble Sweep Preconditioners for propagation problems solved by Optimized Schwarz Methods
Vion, Alexandre ULg; Geuzaine, Christophe ULg

in Proceedings of the 6th International Conference on Advanced COmputational Methods in ENgineering, ACOMEN 2014 (2014, June)

Detailed reference viewed: 8 (1 ULg)
Full Text
See detailWind Tunnel Testing of a VTOL MAV Propeller in Tilted Operating Mode
Theys, Bart; Dimitriadis, Grigorios ULg; Andrianne, Thomas ULg et al

in Proceedings of the 2014 International Conference on Unmanned Aircraft Systems (ICUAS 2014) (2014, May 30)

This paper presents experimental results of the full 3-axis force vector and 3-axis moment vector acting on a propeller, commonly used for a Vertical Take Off and Landing Micro Aerial Vehicle (VTOL MAV ... [more ▼]

This paper presents experimental results of the full 3-axis force vector and 3-axis moment vector acting on a propeller, commonly used for a Vertical Take Off and Landing Micro Aerial Vehicle (VTOL MAV). Measurements were carried out in a wind tunnel using a high resolution 6-axis force/moment sensor embedded in a customized test rig at several wind speeds, propeller rotational speeds and angles of the propeller shaft with respect to the air stream. Results show strong moments acting on the propeller in forward flight and unstable conditions in descending flight. Power calculations reveal a decrease in power consumption during slow forward flight and how motor efficiency can be maximized. [less ▲]

Detailed reference viewed: 9 (3 ULg)
See detailMultidisciplinary rehabilitation program after breast cancer : potential benefits analysis on physical function and quality of life
LECLERC, Anne-France ULg; FOIDART-DESSALLE, Marguerite ULg; COUCKE, Philippe ULg et al

in 29ème Congrès de la Sofmer et 19ème Congrès européen de Médecine Physique et de Réadaptation (2014, May 26)

Objective: To determine the potential benefits, both physically and psychologically, of a multidisciplinary rehabilitation program among women treated for breast cancer. Materials and Methods: Thirty ... [more ▼]

Objective: To determine the potential benefits, both physically and psychologically, of a multidisciplinary rehabilitation program among women treated for breast cancer. Materials and Methods: Thirty patients were recruited, sixteen in the control group and fourteen in the treated group. This group has benefited from a rehabilitation of three months including a supervised training and various psycho-educational sessions. The assessments, performed before and after the programme, included anthropometric and body composition measurements, a functional assessment and various questionnaires. Results: After three months, the health state (quality of life), emotional state, physical, cognitive and social functions and the symptoms of insomnia and anxiety significantly improve in the treated group. This observation also applies to the flexibility, maximal aerobic power / body weight, time to exhaustion during the physical effort test and walking distance in six minutes. In the control group, these improvements do not appear. Discussion: This preliminary study demonstrates the feasibility and benefits of a multidisciplinary approach in women after their treatments for breast cancer. [less ▲]

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailAvantages et inconvénients de l'expatriation
Robert, Jocelyne ULg; Goemans, Adeline; Delagrange, Alexia et al

in Semaine du management (Ed.) Proceedings - semaine du management (2014, May 22)

Detailed reference viewed: 9 (4 ULg)
Full Text
Peer Reviewed
See detailLe conseiller techno-pédagogique, amplificateur du développement professionnel des enseignants ?
Van de Poël, Jean-François ULg; Lecomte, Béatrice ULg; Schaffer, Patrick ULg et al

in Actes du 28ème Congrès de l'Association internationale de pédagogie universitaire (2014, May 20)

La communication présentera trois parcours d’enseignants différents accompagnés par l’IFRES dans la mise en oeuvre d’activités destinées à leurs étudiants de 1er BAC suite à une série de constats liés aux ... [more ▼]

La communication présentera trois parcours d’enseignants différents accompagnés par l’IFRES dans la mise en oeuvre d’activités destinées à leurs étudiants de 1er BAC suite à une série de constats liés aux difficultés rencontrées notamment en matière d’hétérogénéité du public et en matière de taux d’échec important constaté. Les parcours réflexifs et les activités mises en place qui en ont découlé seront analysés au regard des dimensions présentées dans le TPACK. Cette réflexion sera réalisée suite à une prise de données qualitatives auprès des trois enseignants concernés. « Enseigner est un processus complexe qui requiert de la part de l’enseignant des compétences multiples » (Koelher& Mishra, 2006, p.1017-1018, Eberly Center, 2012) et issues de plusieurs domaines (Glaser, 1984, Schulmann 1986, 1987, cités par Koelher& Mishra, 2006, p.61). Intégrer les technologies dans son enseignement complexifie encore plus la tâche pour l’enseignant. Afin de mieux représenter les relations qui existent entre les différents types de connaissances requises pour enseigner, Koelher& Mishra (2006, p. 62-67) ont développé le modèle TPACK (« Technological Pedagogical Content Knowledge ») sur la base du modèle du « Pedagogical Content Knowledge » de Schulman (1987, P. 8-10) auquel ils ont ajouté une dimension technologique qui interagit avec les composantes déjà présentes dans le modèle initial. Au confluent de l’enseignement et de la recherche, le conseiller techno-pédagogique est amené à accompagner les enseignants de son institution dans leurs « réflexions professionnelles » (Paquay, 1996, Perrenoud, 1998, Bass, 1999, Mc Kinney, 2004) ainsi que dans la mise en place d’activités d’enseignement dont la conception fait appel à un grand nombre de dimensions. Dans ce contexte d’accompagnement, le CTP représente donc une véritable interface entre l’enseignant et son questionnement et ce que la recherche en technologies éducatives et en pédagogie universitaire nous apprend. La communication s’interrogera donc également sur la contribution du conseiller technopédagogique (par ses attitudes, ses postures, etc.) à une accentuation, un renforcement de la dimension « recherche innovation » dans la professionnalisation des enseignants qu’il est amené à accompagner. [less ▲]

Detailed reference viewed: 35 (4 ULg)
Full Text
See detailMédecine & sport de haut niveau
Kaux, Jean-François ULg

in Sport et Médecine : droit au but (2014, May 15)

L’engouement pour les activités sportives demeure croissant auprès du grand public grâce à toute une série d’activités sportives novatrices (Zumba, Kaerobic, etc…) et de programmes de remise en forme ... [more ▼]

L’engouement pour les activités sportives demeure croissant auprès du grand public grâce à toute une série d’activités sportives novatrices (Zumba, Kaerobic, etc…) et de programmes de remise en forme (« Je cours pour ma forme », etc…), bénéfiques pour la santé. Cependant, les sportifs de haut niveau, professionnels ou non, valides ou handicapés, représentant l’excellence sportive, reconnus par le code et la charte du sport de haut niveau, ne représentent qu’une infime partie de la totalité des sportifs. Le sport de haut niveau repose sur des critères bien établis: la reconnaissance du caractère de haut niveau des disciplines sportives ; les compétitions de références (jeux olympiques, championnats d’Europe et du Monde…) ; la liste des sportifs de haut niveau ; les filières d’accès au sport de haut niveau. Les sportifs pratiquant au meilleur niveau bénéficient généralement de prédispositions physiques, adéquates au sport pratiqué. Cependant, sans entrainement spécifique (au sport pratiqué), ils ne pourraient pas atteindre ce niveau. Le médecin, travaillant dans l’ombre de ces sportifs, est là pour veiller sur leur santé, développer des stratégies de prévention lésionnelle et les soigner en cas de nécessité. Même s’il a la possibilité de superviser médicalement les compétitions sportives « en première loge », il est également souvent sous la pression arbitrale, des médias, des coaches, des présidents, des sportifs eux-mêmes… Au cours de sa carrière, le sportif risque de se blesser plus ou moins gravement, et se voit obligé de quitter la compétition pour laquelle il s’est préparé durant de nombreuses semaines voire des mois ou des années… Dans ce cas, il sera pris en charge par toute une équipe (kiné, chirurgien, préparateur physique, psychologue…) travaillant en synergie afin de le rétablir au plus vite et de retrouver son plus haut niveau. Avant le retour en compétition, une réathlétisation demeure indispensable. Celle-ci correspond à la reprise d’activité physique, comprenant : toute la phase de réadaptation à l’exercice la phase de transition entre les soins et la reprise de l’entraînement. Il s’agit d’un processus nécessaire à la prévention des blessures et à l’adaptation de l’organisme à un programme d’entraînement poussé. Cependant, il se peut que cette période de l’entraînement soit négligée en raison d’un manque de temps en vue d’un objectif trop proche, majorant le risque de récidive ou de nouvelle blessure. Le sportif de haut niveau se doit de garder une hygiène de vie parfaite, en ayant une alimentation équilibrée, et dénuée de toxique (alcool, drogue…) et en respectant des périodes de repos nécessaires entre les différentes phases d’activité physique. De plus, afin d’améliorer ses performances sportives, la préparation physique (endurance, résistance, force musculaire, souplesse…) et l’entrainement spécifique à chaque sport (technique, tactique, adresse et précision…) demeurent indispensables. Dès lors, la tentation de les améliorer artificiellement existe. En effet, le dopage consiste à absorber des substances ou à utiliser des actes médicaux afin d’augmenter artificiellement ses capacités physiques et/ou mentales. Or, l’utilisation de tout médicament devrait être limitée à des indications médicalement justifiées. Le code mondial anti-dopage est régit par l’Agence Mondiale Antidopage (AMA / WADA ; www.wada-ama.org ou www.dopage.be) et la liste des produits dopants est revue chaque année. [less ▲]

Detailed reference viewed: 47 (6 ULg)
Peer Reviewed
See detailConcept et agencement de la lutte contre la "fraude sociale"
Kéfer, Fabienne ULg

in Vermeulen, Geert; Masset, Adrien; Flore, Daniel (Eds.) Comment s'en prendre à la fraude sociale, l'exploitation au travail et la traite des êtres humains : défis et solutions aux niveaux national et européen (2014, May 11)

Detailed reference viewed: 19 (1 ULg)
Full Text
See detailInspired bio- nanobiomaterials for tissue engineering and drug delivery systems
Grandfils, Christian ULg

in Vth International Workshop on "NANOPARTICLES, COATINGS AND MICROCONTAINERS: TECHNOLOGY, PROPERTIES, APPLICATIONS" Conference Materials (2014, May 09)

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailProjet de recherche appliquée SpatioData : Spécification d’un système participatif pour la réutilisation de données sporadiques sur le bâtiment
Ben Rajeb, Samia ULg; Delfosse, Vincent ULg; Boulanger, Christelle ULg et al

in Proceedings du colloque 01'Design 9 (2014, May 09)

Cet article présente un projet de recherche nommé SpatioData qui a duré trois ans et dont l’objectif visait l’exploitation de nouvelles technologies de l’information et de la communication (TIC) pour ... [more ▼]

Cet article présente un projet de recherche nommé SpatioData qui a duré trois ans et dont l’objectif visait l’exploitation de nouvelles technologies de l’information et de la communication (TIC) pour proposer un outil innovant permettant la réutilisation d’informations liées au bâtiment. Nous montrerons, au travers d’enquêtes et d’interviews, l’importance de faciliter l’accès aux données rattachées à l’historique du bâtiment via un système innovant et intuitif qui permettra à tous les acteurs du secteur de la construction et de la gestion immobilière de trouver et de partager des informations utiles, c’est-à-dire des données spécialisées, contextualisées et spatialisées, en temps réel. Nous listerons des recommandations afin que ces données, qui auraient été perdues ou jetées, puissent être automatiquement mises en relation avec le lieu de l’intervention (géoréférencement) et le type d’intervenant (utilisateur) permettant ainsi de compléter une base de données spatialisées basée sur un modèle de bâtiment spécifique. [less ▲]

Detailed reference viewed: 35 (8 ULg)
Full Text
Peer Reviewed
See detailNumerical Simulation of a Conical Shape Made by Single Point Incremental Forming
Velosa De Sena, José ULg; Duchene, Laurent ULg; Habraken, Anne ULg et al

in Incremental sheet forming (2014, May 08)

Detailed reference viewed: 18 (6 ULg)
Full Text
Peer Reviewed
See detailA hybrid human-computer approach for large-scale image-based measurements using web services and machine learning
Marée, Raphaël ULg; Rollus, Loïc ULg; Stevens, Benjamin ULg et al

in Proceedings IEEE International Symposium on Biomedical Imaging (2014, May)

We present a novel methodology combining web-based software development practices, machine learning, and spatial databases for computer-aided quantification of regions of interest (ROIs) in large-scale ... [more ▼]

We present a novel methodology combining web-based software development practices, machine learning, and spatial databases for computer-aided quantification of regions of interest (ROIs) in large-scale imaging data. We describe our main methodological choices, and then illustrate the benefits of the approach (workload reduction, improved precision, scalability, and traceability) on hundreds of whole-slide images of biological tissue slices in cancer research. [less ▲]

Detailed reference viewed: 202 (41 ULg)
Full Text
Peer Reviewed
See detailImprovement in non-linear guitar loudspeaker sound reproduction
Schmitz, Thomas ULg; Embrechts, Jean-Jacques ULg

in International Conference on Systems, Signals and Image Processing (2014, May)

This paper proposes a study of the accuracy of a guitar amplifier loudspeaker simulation. The simulation is based on a non-linear convolution of a signal using Volterra kernels, which are measured in ... [more ▼]

This paper proposes a study of the accuracy of a guitar amplifier loudspeaker simulation. The simulation is based on a non-linear convolution of a signal using Volterra kernels, which are measured in anechoic conditions with a sine-sweep technique. In this paper, we propose an evaluation of the method to minimise the cost in CPU load, while keeping the best performance in the sound reproduction. To assess the performance of the method, we measure errors between the simulated and real sounds. Human listening tests are moreover proposed in order to determine the minimum level of accuracy leading to unaudible differences with the real loudspeaker.. [less ▲]

Detailed reference viewed: 48 (12 ULg)
See detailTest equipments for characterizing the behavior of materials, bearings and dynamic seals in cryogenic fluid environments
Bozet, Jean-Luc ULg; Servais, Christophe ULg; Duquenne, Marc ULg et al

in Space Propulsion 2014 (2014, May)

Test rigs available at the cryogenic test site of the University of Liège concern quite delicate high rotational speed components of cryogenic rocket engines. That is to say bearings and dynamic seals ... [more ▼]

Test rigs available at the cryogenic test site of the University of Liège concern quite delicate high rotational speed components of cryogenic rocket engines. That is to say bearings and dynamic seals. These rigs gave successfully important results for the understanding and the improvement of the running of the so called components. Until now the test zone is equipped for handling liquid oxygen and liquid nitrogen. [less ▲]

Detailed reference viewed: 13 (2 ULg)
Full Text
Peer Reviewed
See detailApprentissage par renforcement bayésien versus recherche directe de politique hors-ligne en utilisant une distribution a priori: comparaison empirique
Castronovo, Michaël ULg; Ernst, Damien ULg; Fonteneau, Raphaël ULg

in Proceedings des 9èmes Journée Francophones de Planification, Décision et Apprentissage (2014, May)

Cet article aborde le problème de prise de décision séquentielle dans des processus de déci- sion de Markov (MDPs) finis et inconnus. L’absence de connaissance sur le MDP est modélisée sous la forme ... [more ▼]

Cet article aborde le problème de prise de décision séquentielle dans des processus de déci- sion de Markov (MDPs) finis et inconnus. L’absence de connaissance sur le MDP est modélisée sous la forme d’une distribution de probabilité sur un ensemble de MDPs candidats connue a priori. Le cri- tère de performance utilisé est l’espérance de la somme des récompenses actualisées sur une trajectoire infinie. En parallèle du critère d’optimalité, les contraintes liées au temps de calcul sont formalisées rigoureusement. Tout d’abord, une phase « hors-ligne » précédant l’interaction avec le MDP inconnu offre à l’agent la possibilité d’exploiter la distribution a priori pendant un temps limité. Ensuite, durant la phase d’interaction avec le MDP, à chaque pas de temps, l’agent doit prendre une décision dans un laps de temps contraint déterminé. Dans ce contexte, nous comparons deux stratégies de prise de déci- sion : OPPS, une approche récente exploitant essentiellement la phase hors-ligne pour sélectionner une politique dans un ensemble de politiques candidates et BAMCP, une approche récente de planification en-ligne bayésienne. Nous comparons empiriquement ces approches dans un contexte bayésien, en ce sens que nous évaluons leurs performances sur un large ensemble de problèmes tirés selon une distribution de test. A notre connaissance, il s’agit des premiers tests expérimentaux de ce type en apprentissage par renforcement. Nous étudions plusieurs cas de figure en considérant diverses distributions pouvant être utilisées aussi bien en tant que distribution a priori qu’en tant que distribution de test. Les résultats obtenus suggèrent qu’exploiter une distribution a priori durant une phase d’optimisation hors-ligne est un avantage non- négligeable pour des distributions a priori précises et/ou contraintes à de petits budgets temps en-ligne. [less ▲]

Detailed reference viewed: 53 (19 ULg)
Full Text
Peer Reviewed
See detailEstimating the revenues of a hydrogen-based high-capacity storage device: methodology and results
François-Lavet, Vincent ULg; Fonteneau, Raphaël ULg; Ernst, Damien ULg

in Proceedings des 9èmes Journée Francophones de Planification, Décision et Apprentissage (2014, May)

This paper proposes a methodology to estimate the maximum revenue that can be generated by a company that operates a high-capacity storage device to buy or sell electricity on the day-ahead electricity ... [more ▼]

This paper proposes a methodology to estimate the maximum revenue that can be generated by a company that operates a high-capacity storage device to buy or sell electricity on the day-ahead electricity market. The methodology exploits the Dynamic Programming (DP) principle and is specified for hydrogen-based storage devices that use electrolysis to produce hydrogen and fuel cells to generate electricity from hydrogen. Experimental results are generated using historical data of energy prices on the Belgian market. They show how the storage capacity and other parameters of the storage device influence the optimal revenue. The main conclusion drawn from the experiments is that it may be interesting to invest in large storage tanks to exploit the inter-seasonal price fluctuations of electricity. [less ▲]

Detailed reference viewed: 56 (23 ULg)
Full Text
See detailExpression of peroxisome-proliferator activated receptor alpha in pituitary tumours
Rotondi, S; Modarelli, A; Rostomyan, Liliya ULg et al

in Endocrine Abstracts (2014, May)

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailToggling a genetic switch using reinforcement learning
Sootla, Aivar; Strelkowa, Natalja; Ernst, Damien ULg et al

in Proceedings of the 9th French Meeting on Planning, Decision Making and Learning (2014, May)

In this paper, we consider the problem of optimal exogenous control of gene regulatory networks. Our approach consists in adapting an established reinforcement learning algorithm called the fitted Q ... [more ▼]

In this paper, we consider the problem of optimal exogenous control of gene regulatory networks. Our approach consists in adapting an established reinforcement learning algorithm called the fitted Q iteration. This algorithm infers the control law directly from the measurements of the system’s response to external control inputs without the use of a mathematical model of the system. The measurement data set can either be collected from wet-lab experiments or artificially created by computer simulations of dynamical models of the system. The algorithm is applicable to a wide range of biological systems due to its ability to deal with nonlinear and stochastic system dynamics. To illustrate the application of the algorithm to a gene regulatory network, the regulation of the toggle switch system is considered. The control objective of this problem is to drive the concentrations of two specific proteins to a target region in the state space. [less ▲]

Detailed reference viewed: 29 (1 ULg)
Full Text
See detailEulerian Formulation of the Torque and Drag Problem
Huynen, Alexandre ULg; Detournay, Emmanuel; Denoël, Vincent ULg

in Detournay, Emmanuel; Denoël, Vincent; van de Wouw, Nathan (Eds.) Third International Colloquium on Nonlinear Dynamics and Control of Deep Drilling Systems (2014, May)

Detailed reference viewed: 28 (13 ULg)
Full Text
Peer Reviewed
See detailPerformances of low-level audio classifiers for large-scale music similarity
Osmalsky, Julien ULg; Van Droogenbroeck, Marc ULg; Embrechts, Jean-Jacques ULg

in International Conference on Systems, Signals and Image Processing (2014, May)

This paper proposes a survey of the performances of binary classifiers based on low-level audio features, for music similarity in large-scale databases. Various low-level descriptors are used individually ... [more ▼]

This paper proposes a survey of the performances of binary classifiers based on low-level audio features, for music similarity in large-scale databases. Various low-level descriptors are used individually and then combined using several fusion schemes in a content-based audio retrieval system. We show the performances of the classifiers in terms of pruning and loss and we demonstrate that some combination schemes achieve a better performance at a minimum computational cost. [less ▲]

Detailed reference viewed: 70 (26 ULg)
Full Text
Peer Reviewed
See detailGestion active d’un réseau de distribution d’électricité : formulation du problème et benchmark
Gemine, Quentin ULg; Ernst, Damien ULg; Cornélusse, Bertrand ULg

in Proceedings des 9èmes Journées Francophones de Planification, Décision et Apprentissage (2014, May)

Afin d’opérer un réseau de distribution d’électricité de manière fiable et efficace, c’est-à-dire de respecter les contraintes physiques tout en évitant des coûts de renforcement prohibitifs, il devient ... [more ▼]

Afin d’opérer un réseau de distribution d’électricité de manière fiable et efficace, c’est-à-dire de respecter les contraintes physiques tout en évitant des coûts de renforcement prohibitifs, il devient nécessaire de recourir à des stratégies de gestion active du réseau. Ces stratégies, rendues nécessaires notamment par l’essor de la production distribuée, reposent sur des politiques de contrôle à court-terme du niveau de puissance des dispositifs producteurs ou consommateurs d’électricité. Alors qu’une solution simple consisterait à moduler à la baisse la production des générateurs, il paraît néan- moins plus intéressant de déplacer la consommation aux moments adéquats afin d’exploiter au mieux les sources d’énergie renouvelables sur lesquelles reposent généralement ces générateurs. Un tel moyen de contrôle introduit néanmoins un couplage temporel au problème, menant à un problème d’optimisation non-linéaire, séquentiel sous incertitude et à variables mixtes. Afin de favoriser la recherche dans ce domaine très complexe, nous proposons une formalisation générique du problème de ges- tion active d’un réseau de distribution moyenne tension (MT). Plus spécifiquement, cette formalisa- tion se présente sous la forme d’un processus de décision markovien. Dans cette article, nous pré- sentons également une spécification de ce modèle décisionnel à un réseau de 75 noeuds et pour un ensemble de services de modulation donnés. L’instance de test qui en résulte est disponible à l’adresse http://www.montefiore.ulg.ac.be/~anm/ et a pour objectif de mesurer et de comparer les performances des techniques de résolution qui seront développées. [less ▲]

Detailed reference viewed: 158 (43 ULg)
Full Text
Peer Reviewed
See detailToggling a genetic switch using reinforcement learning
Sootla, Aivar; Strelkowa, Natalja; Ernst, Damien ULg et al

in Proceedings of the 9th French Meeting on Planning, Decision Making and Learning (2014, May)

In this paper, we consider the problem of optimal exogenous control of gene regulatory networks. Our approach consists in adapting an established reinforcement learning algorithm called the fitted Q ... [more ▼]

In this paper, we consider the problem of optimal exogenous control of gene regulatory networks. Our approach consists in adapting an established reinforcement learning algorithm called the fitted Q iteration. This algorithm infers the control law directly from the measurements of the system’s response to external control inputs without the use of a mathematical model of the system. The measurement data set can either be collected from wet-lab experiments or artificially created by computer simulations of dynamical models of the system. The algorithm is applicable to a wide range of biological systems due to its ability to deal with nonlinear and stochastic system dynamics. To illustrate the application of the algorithm to a gene regulatory network, the regulation of the toggle switch system is considered. The control objective of this problem is to drive the concentrations of two specific proteins to a target region in the state space. [less ▲]

Detailed reference viewed: 29 (1 ULg)
Full Text
Peer Reviewed
See detailDesign of a reliable processing pipeline for the non-intrusive measurement of feet trajectories with lasers
Pierard, Sébastien ULg; Azrour, Samir ULg; Van Droogenbroeck, Marc ULg

in International Conference on Acoustics, Speech, and Signal Processing (ICASSP) (2014, May)

Reliable measurements of feet trajectories are needed in some applications, such as biomedical applications. This paper describes the data processing pipeline used in GAIMS, which is a non-intrusive ... [more ▼]

Reliable measurements of feet trajectories are needed in some applications, such as biomedical applications. This paper describes the data processing pipeline used in GAIMS, which is a non-intrusive system that measures feet trajectories based on multiple range laser scanners. Our processing pipeline relies on a new tracking paradigm, and it is based on two innovative algorithms: the first algorithm localizes the feet directly from the observed point cloud without any clustering, and the other algorithm identifies the feet. After reviewing the various types of noise affecting the point cloud, this paper explains the limitations of the classical processing approach and gives an overview of our new pipeline. The effectiveness of the proposed approach is established by discussing the results that have been obtained in several studies based on GAIMS. [less ▲]

Detailed reference viewed: 65 (21 ULg)
Full Text
Peer Reviewed
See detailEviter la tour d'ivoire, éviter les allées du pouvoir
Jacquemain, Marc ULg

in Delchambre, Jean-Pierre (Ed.) Le sociologue comme médiateur ? Accords, désaccords et malentendus (2014, May)

L'article s'interroge sur la nature de l'expertise en sciences sociales. En partant de la définition de l'expertise en général par Philippe Roqueplo, on défend que la sociologie ne peut prétendre à une ... [more ▼]

L'article s'interroge sur la nature de l'expertise en sciences sociales. En partant de la définition de l'expertise en général par Philippe Roqueplo, on défend que la sociologie ne peut prétendre à une connaissance scientifique que dans le cadre des questions qu'elle pose elle-même en tant que discipline. Cela ne la dispense pas de répondre aux questions que se pose la société et, en particulier, les pouvoirs publics, mais les réponses n'ont pas le statut de réponses scientifiques. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
See detailApplication of multiple-point geostatistics on modelling pumping tests and tracer tests in heterogeneous environments with complex geological structures
Huysmans, Marijke; Dassargues, Alain ULg

in Geophysical Research Abstracts (2014, April 28)

In heterogeneous environments with complex geological structures, analysis of pumping and tracer tests is often problematic. Standard interpretation methods do not account for heterogeneity or simulate ... [more ▼]

In heterogeneous environments with complex geological structures, analysis of pumping and tracer tests is often problematic. Standard interpretation methods do not account for heterogeneity or simulate this heterogeneity introducing empirical zonation of the calibrated parameters or using variogram-based geostatistical techniques that are often not able to describe realistic heterogeneity in complex geological environments where e.g. sedimentary structures, multi-facies deposits, structures with large connectivity or curvi-linear structures can be present. Multiple-point geostatistics aims to overcome the limitations of the variogram and can be applied in different research domains to simulate heterogeneity in complex environments. In this project, multiple-point geostatistics is applied to the interpretation of pumping tests and a tracer test in an actual case of a sandy heterogeneous aquifer. This study allows to deduce the main advantages and disadvantages of this technique compared to variogram-based techniques for interpretation of pumping tests and tracer tests. A pumping test and a tracer test were performed in the same sandbar deposit consisting of cross-bedded units composed of materials with different grain sizes and hydraulic conductivities. The pumping test and the tracer test are analyzed with a local 3D groundwater model in which fine-scale sedimentary heterogeneity is modelled using multiple-point geostatistics. To reduce CPU and RAM requirements of the multiple-point geostatistical simulation steps, edge properties indicating the presence of irregularly-shaped surfaces are directly simulated. Results show that for the pumping test as well as for the tracer test, incorporating heterogeneity results in a better fit between observed and calculated drawdowns/concentrations. The improvement of the fit is however not as large as expected. In this paper, the reasons for these somewhat unsatisfactory results are explored and recommendations for future applications of multiple-point geostatistics on pumping tests and tracer tests are formulated. [less ▲]

Detailed reference viewed: 10 (0 ULg)
Full Text
See detailThermal tracer tests for characterizing a shallow alluvial aquifer
Wildemeersch, Samuel ULg; Klepikova, Maria ULg; Jamin, Pierre ULg et al

in Geophysical Research Abstracts (2014, April 28)

Using heat as an active tracer in different types of aquifers is a topic of increasing interest [e.g. Vandenbohede et al.; 2008, Wagner et al., 2013; Read et al., 2013]. In this study, we investigate the ... [more ▼]

Using heat as an active tracer in different types of aquifers is a topic of increasing interest [e.g. Vandenbohede et al.; 2008, Wagner et al., 2013; Read et al., 2013]. In this study, we investigate the potential interest of coupling heat and solute tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in the recovery well and in nine monitoring wells located according to three transects with regards to the main groundwater flow direction. The breakthrough curves measured in the recovery well showed that heat transfer in the alluvial aquifer is slower and more dispersive than solute transport. Recovery is very low for heat while in the same time it is measured as relatively high for the solute tracer. This is due to the fact that heat diffusion is larger than molecular diffusion, implying that exchange between groundwater and the porous medium matrix is far more significant for heat than for solute tracers. Temperature and concentrations in the recovery well are then used for estimating the specific heat capacity with the energy balance approach and the estimated value is found to be consistent with those found in the literature. Temperature breakthrough curves in other piezometers are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. By means of a numerical heat transport model, we provide a preliminary interpretation of these temperature breakthrough curves. Furthermore, these data could be included in the calibration of a complex heat transfer model for estimating the entire set of heat transfer parameters and their spatial distribution by inverse modeling. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
See detailMicrofossils’ diversity from the Proterozoic Taoudeni Basin, Mauritania
Beghin, Jérémie ULg; Javaux, Emmanuelle ULg; Houzay, Jean-Pierre et al

in European Geosciences Union General Assembly 2014 Vienna, Austria, 27 April – 02 May 2014 (abstract book) (2014, April 27)

Detailed reference viewed: 24 (2 ULg)
Full Text
Peer Reviewed
See detailMachine learning techniques to assess the performance of a gait analysis system
Pierard, Sébastien ULg; Phan-Ba, Rémy; Van Droogenbroeck, Marc ULg

in European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN) (2014, April 24)

This paper presents a methodology based on machine learning techniques to assess the performance of a system measuring the trajectories of the lower limbs extremities for the follow-up of patients with ... [more ▼]

This paper presents a methodology based on machine learning techniques to assess the performance of a system measuring the trajectories of the lower limbs extremities for the follow-up of patients with multiple sclerosis. We show how we have established, with the help of machine learning, four important properties about this system: (1) an automated analysis of gait characteristics provides an improved analysis with respect to that of a human expert, (2) after learning, the gait characteristics provided by this system are valuable compared to measures taken by stopwatches, as used in the standardized tests, (3) the motion of the lower limbs extremities contains a lot of useful information about the gait, even if it is only a small part of the body motion, (4) a measurement system combined with a machine learning tool is sensitive to intra-subject modifications of the walking pattern. [less ▲]

Detailed reference viewed: 53 (7 ULg)
Peer Reviewed
See detailPredicting Grain Protein Content of Winter Wheat
Mansouri, Majdi ULg; Dumont, Benjamin ULg; Destain, Marie-France ULg

in ESANN 2014 Proceedings (2014, April 24)

Detailed reference viewed: 22 (9 ULg)
Full Text
See detailLa Belgique, un pays complexe
Hermans, Michel ULg

in Perdigon, Marie-France (Ed.) Actes des VIIème entretiens sur l'identité européenne (2014, April 19)

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailAtrial Natriuretic Peptide in cardiac horses
Leroux, Aurélia ULg; Al-Haidar, Ali; Remy, Benoît ULg et al

in Voorjaarsdagen Proceedings (2014, April 17)

Background: Natriuretic peptides are cardiac biomarkers that have been shown to have high potential for diagnosis, prognosis, and guidance of treatment in human and small animal cardiology. However, their ... [more ▼]

Background: Natriuretic peptides are cardiac biomarkers that have been shown to have high potential for diagnosis, prognosis, and guidance of treatment in human and small animal cardiology. However, their diagnostic and prognosis value in the equine species has only been studied in a limited number of cases. Objective: To investigate the plasma atrial natriuretic peptide concentration (ANPPl) in a large group of horses with various degrees of valvular regurgitation (VR) and heart failure (HF). Animals: Ninety-one horses, admitted at the equine teaching hospital of the University of Liege, and with no, mild, moderate or severe VR and presenting various stages of HF, according to human and canine grading system (A: no VR, B1: asymptomatic VR without cardiac remodelling, B2: asymptomatic VR with cardiac remodelling, C: symptomatic VR). Methods: All horses underwent clinical and Doppler echocardiographic examination, which allowed determining the presence, nature, and severity of VR, and the HF stage. The ANPPl was measured using a commercially available human RIA test. The mean values of body weight, age, ANPPl and each echocardiographic parameter were compared between horses in stage A, B1, B2 or C of HF and between horses with no, mild, moderate or severe VR, using a one-way ANOVA test. Then, correlations between ANPPl and each echocardiographic parameter were assessed using a Pearson’s product-moment analysis. Results: Horses with severe and moderate VR had significantly higher ANPPl than horses with mild or no VR. ANPPl was significantly higher in horses at stage B2 and C of HF than horses at stage A and B1. Moreover, ANPPl was significantly correlated with most of the measured echocardiographic variables. This correlation was especially strong with the left atrial diameter and its percentage of dilation. Conclusions and Clinical Importance: Those results suggest that ANPPl in horses suffering from VR could have a high diagnostic value of HF, especially in horses with tricuspid or mitral insufficiency and with enlargement or dysfunction of the atria. [less ▲]

Detailed reference viewed: 21 (8 ULg)
Full Text
See detailObserving the Sun with micro-interferometric devices: a didactic experiment
Defrere, D.; Absil, Olivier ULg; Hanot, C. et al

in Surdej, Jean; Le Coroller, Hervé; Arnold, Luc (Eds.) Improving the Performances of Current Optical Interferometers & Future Designs (2014, April 01)

Measuring the angular diameter of celestial bodies has long been the main purpose of stellar interferometry and was its historical motivation. Nowadays, stellar interferometry is widely used for various ... [more ▼]

Measuring the angular diameter of celestial bodies has long been the main purpose of stellar interferometry and was its historical motivation. Nowadays, stellar interferometry is widely used for various other scientific purposes that require very high angular resolution measurements. In terms of angular spatial scales probed, o [less ▲]

Detailed reference viewed: 5 (1 ULg)
Full Text
See detailPIONIER : A Four Telescope VLTI Instrument
Lazareff, B.; Le Bouquin, J.-L.; Berger, J.-P. et al

in Surdej, Jean; Le Coroller, Hervé; Arnold, Luc (Eds.) Improving the Performances of Current Optical Interferometers & Future Designs (2014, April 01)

Pionier is a guest instrument, the first four-telescope recombiner at ESO's VLTI. We discuss salient design features and illustrate selected scientific results from the fi

Detailed reference viewed: 9 (1 ULg)
Peer Reviewed
See detailOptimized Waveform Relaxation Methods for Modeling Electromagnetic Field-Circuit Problems
Nshimiyimana, Jean de Dieu ULg; Plumier, Frédéric ULg; Dular, Patrick ULg et al

in Proceedings of Sixteenth Biennal IEEE Conference on Electromagnetic Field Computation (2014, April)

The convergence of classical and optimized waveform relaxation methods is compared for the simulation of field-circuit problems, where a finite element solver is used for the solution of the field problem ... [more ▼]

The convergence of classical and optimized waveform relaxation methods is compared for the simulation of field-circuit problems, where a finite element solver is used for the solution of the field problem and a circuit simulator is used for the electronic circuit. [less ▲]

Detailed reference viewed: 24 (8 ULg)
Full Text
See detailDynamics of a Strongly Nonlinear Spacecraft Structure Part II: Modal Analysis
Renson, Ludovic ULg; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg

in Proceedings of the 13th European Conference on Spacecraft Structures, Materials & Environmental Testing (2014, April)

The present paper investigates the dynamics of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. A full-scale finite element model is built for ... [more ▼]

The present paper investigates the dynamics of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. A full-scale finite element model is built for gaining additional insight into the nonlinear dynamics that was observed experimentally in a companion paper (Part I). To this end, advanced techniques and theoretical concepts such as numerical continuation and nonlinear normal modes are exploited. [less ▲]

Detailed reference viewed: 49 (1 ULg)
Peer Reviewed
See detailThe Tale of Sinuhe: History of a literary text
Winand, Jean ULg

in Hays, Harold; Feder, Frank; Morenz, Ludwig (Eds.) Interpretations of Sinuhe (2014, April)

Detailed reference viewed: 75 (5 ULg)
Full Text
See detailDynamics of a Strongly Nonlinear Spacecraft Structure Part I: Experimental Identification
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Proceedings of the 13th European Conference on Spacecraft Structures, Materials and Environmental Testing (2014, April)

The present paper addresses the identification of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. The complete identification procedure, from ... [more ▼]

The present paper addresses the identification of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. The complete identification procedure, from nonlinearity detection and characterization to parameter estimation, is carried out based upon experimental sine-sweep data collected during a classical spacecraft qualification campaign. [less ▲]

Detailed reference viewed: 37 (4 ULg)
Full Text
Peer Reviewed
See detailData normalization and supervised learning to assess the condition of patients with multiple sclerosis based on gait analysis
Azrour, Samir ULg; Pierard, Sébastien ULg; Geurts, Pierre ULg et al

in European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN) (2014, April)

Gait impairment is considered as an important feature of disability in multiple sclerosis but its evaluation in the clinical routine remains limited. In this paper, we assess, by means of supervised ... [more ▼]

Gait impairment is considered as an important feature of disability in multiple sclerosis but its evaluation in the clinical routine remains limited. In this paper, we assess, by means of supervised learning, the condition of patients with multiple sclerosis based on their gait descriptors obtained with a gait analysis system. As the morphological characteristics of individuals influence their gait while being in first approximation independent of the disease level, an original strategy of data normalization with respect to these characteristics is described and applied beforehand in order to obtain more reliable predictions. In addition, we explain how we address the problem of missing data which is a common issue in the field of clinical evaluation. Results show that, based on machine learning combined to the proposed data handling techniques, we can predict a score highly correlated with the condition of patients. [less ▲]

Detailed reference viewed: 119 (41 ULg)
Full Text
Peer Reviewed
See detailCharacterization of printed circuit boards from scrap printers
Silvas, Flávia; de Moraes, Viviane; Bortolini, Guilherme et al

in Yurko, James; Zhang, Lifeng; Allanore, Antoine (Eds.) Proceedings TMS 2014 143rd ANNUAL MEETING & EXHIBITION (2014, April)

Printed circuit boards (PCB) are particularly problematic to recycle because of the heterogeneous mix of organic materials, metals, and glass fiber. PCBs are found in almost every electroelectronic ... [more ▼]

Printed circuit boards (PCB) are particularly problematic to recycle because of the heterogeneous mix of organic materials, metals, and glass fiber. PCBs are found in almost every electroelectronic equipment and their recycling process involves a pre-treatment to separate the products which contain targeted metals. In this work, a physical processing involving sequential shredding and hammer milling were used to obtain a comminuted sample from scrap printers PCBs. The thus prepared sample was analyzed for particle size distribution and by optical microscopy as well was subjected to pyrolysis, leachabilty and chemical composition determination by XRF. The metals concentration was determined by ICP and AAS. The PCBs have been also analyzed by SEM-EDS (micro-analysis and X-ray mapping). The results show that the studied PCBs are lead free, multilayer with 4 copper layers, have 45% of metals and the copper is present in significantly higher concentration than the rest of the metals. [less ▲]

Detailed reference viewed: 25 (2 ULg)
Full Text
Peer Reviewed
See detailINFLUENCE OF WHEY PROTEIN DENATURATION ON ADHERENCE
Toure, Yetioman ULg; Rouxhet, G. Paul; Dupont-Gillain, C. Christine et al

in Dr Wilson, I.; Chew, Y.M.J. (Eds.) Fouling and Cleaning in Food Processing (2014, April)

This work reports on the influence of -lactoglobulin (β-LGB) and of its denaturation on the adherence of quartz particles, taken as a model of particulate soil, on stainless steel AISI 304 with mirror ... [more ▼]

This work reports on the influence of -lactoglobulin (β-LGB) and of its denaturation on the adherence of quartz particles, taken as a model of particulate soil, on stainless steel AISI 304 with mirror finish. The substrate was soiled with quartz suspensions in water or in β-LGB solutions as such or previously heated at 75°C, and dried at room temperature or in an oven at 75°C. Cleanability was evaluated after exposure to water in a radial flow chamber. Auxiliary characterizations were the surface tension and protein concentration of the solution, surface analysis of the substrate by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The contact of stainless steel with -LGB led to adsorption of the protein, which dominated the composition of the organic layer with respect to contaminants initially present, and was not markedly desorbed upon rinsing. The presence of β-LGB at the quartz particle/substrate interface slightly increased the adherence, which was further increased when the protein was denatured. On the other hand, denaturation of -LGB enhanced its surfactant effect at the water/air interface. Comparison with systems investigated before suggests that the influence of protein via droplet spreading and soiling particles aggregation may be of minor importance compared to direct effects on the substrate/quartz interface. Stainless steel does not behave as a hydrophilic substrate owing to its surface contamination with organic compounds. It appears suitable to examine the influence of the initial surface state of stainless steel on its behavior regarding soiling and cleaning. [less ▲]

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailEtiologie de la myopathie atypique : conditions de toxicité de l’agent causal – étude préliminaire
Patarin; van Galen, Gaby; Dopagne, Claude ULg et al

in 40ème journée de la recherche équine (2014, March 18)

Recently it has been shown that atypical myopathy in Europe results from hypoglycin A ingestion, a toxin produced in the seeds (samares) of some trees of the genus Acer. Grasslands of 12 cases of atypical ... [more ▼]

Recently it has been shown that atypical myopathy in Europe results from hypoglycin A ingestion, a toxin produced in the seeds (samares) of some trees of the genus Acer. Grasslands of 12 cases of atypical myopathy for whom the toxic metabolite of hypoglycin A was found in the blood were visited by two experienced botanists in order to establish the list of the different species of trees found in or around these pastures. For all visited pastures, horses had the opportunity to ingest samaras from various maple species. The sycamore maple (Acer pseudoplatanus) was the only common tree in all pastures visited (n = 12 /12). Other trees with samaras were also found near or around the pastures. Since June 2013, a study is conducted to define the conditions of toxicity of several species of trees via the sampling, at regular intervals, of samaras and leaves. The study of the seasonal evolution of the toxicity of these trees in relation to weather conditions and specific biotopes will aim [less ▲]

Detailed reference viewed: 159 (14 ULg)
Full Text
Peer Reviewed
See detailParallel Computing and Localization Techniques for Faster Power System Dynamic Simulations
Aristidou, Petros ULg; Van Cutsem, Thierry ULg

in Proceedings of Cigre 2014 Belgium Conference (2014, March 13)

Dynamic simulation studies are used to analyze the behavior of power systems after a disturbance has occurred. This type of simulation is essential when the system is operating close to its stability ... [more ▼]

Dynamic simulation studies are used to analyze the behavior of power systems after a disturbance has occurred. This type of simulation is essential when the system is operating close to its stability limits or its behavior is dictated by complex control and protection schemes modifying its trajectory. These simulations can be computationally very demanding, especially if performed over a time interval of several minutes. In this paper, new shared- memory parallel computing techniques to increase the performance of large-scale power system dynamic simulations are described. The algorithms presented achieve this by utilizing the parallel processing resources available in modern, inexpensive, multi-core machines. In addition, the localized response of power systems after a disturbance is exploited to further accelerate simulations without decreasing accuracy. The medium-scale model of a real power system and a realistic large-scale test system have been used for the performance evaluation of the proposed methods. [less ▲]

Detailed reference viewed: 97 (25 ULg)
Full Text
See detailWearable respiratory belt for human breathing control
Stoukatch, Serguei ULg; Léonard, Jean; Bellier, Pierre ULg et al

in Conf. Proc. Smart Systems Integration Conf. (SSI2014) (2014, March 12)

We designed and manufactured a working prototype of a wearable respiratory belt. The belt can work as a stand along system or can be embedded into clothes. The system is intended for remote health ... [more ▼]

We designed and manufactured a working prototype of a wearable respiratory belt. The belt can work as a stand along system or can be embedded into clothes. The system is intended for remote health monitoring (particularly to monitor human respiration) such as home healthcare, remote medicine and remote socio-medical assistance as well as to monitor patients. The fully functional prototype proofs the concept that the elongation in the respiratory belt causes by human respiration is accurate enough to measure and to monitor human respiration. [less ▲]

Detailed reference viewed: 58 (3 ULg)
Full Text
Peer Reviewed
See detailNew insights for an old topic: seagrasses as bioindicators of coastal trace element pollution
Richir, Jonathan ULg; Lejeune, Pierre; Gobert, Sylvie ULg

in ARGYRO ZENETOS, ZENETOS (Ed.) Mediterranean Marine Science (2014, March)

The marine magnoliophyte Posidonia oceanica (L.) Delile has been widely used since the mid-70th to biomonitor the coastal pollution of the Mediterranean in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe. In contrast ... [more ▼]

The marine magnoliophyte Posidonia oceanica (L.) Delile has been widely used since the mid-70th to biomonitor the coastal pollution of the Mediterranean in Cr, Ni, Cu, Zn, Cd, Pb and/or Fe. In contrast, other trace elements (TEs) like As, V, Ag, Be, Al, Mn, Co, Se, Mo, Sn, Sb and Bi, many of them categorized as TEs of environmental emerging concern, have been subject to nearly no ecotoxicological survey with that species. It has been shown that the French Mediterranean littoral was submitted to local, diffuse and/or chronic contaminations both by TEs broadly or little biomonitored with P. oceanica; high TE levels could further be linked to specific anthropic activities such as agriculture (Mo), mining (Cr, Sb, Zn), industries (As), storage and refinement of oil products (V, Pb) or presence of major ports and urban centres (Sn, Bi, Ag). It seems therefore necessary to expand the short list of the seven metals commonly monitored to other TEs, what is today easily achievable as current analytical methods allow the simultaneous determination of all a series of TEs within the same sample. Furthermore, only a multielement analysis in appropriate bioindicator species allow to correctly intercompare the pollution status of numerous sampling sites. To do this, we have calculated proper environmental indices, the trace element pollution index TEPI and the trace element spatial variation index TESVI. The TEPI is an index of the global contamination of a site, giving the same weight to each TE after mean normalization of their environmental concentrations. The TESVI estimates the global spatial variability of environmental concentrations of each TE levels, taking into account both punctual contaminations in impacted sites and the overall coastal spatial heterogeneity between all monitored sites.These two indices were successfully applied both at large (French Mediterranean littoral) and small (a Bay) spatial scales. Furthermore, they can be used in the framework of an intercomparative study compiling data from any previous monitoring surveys. We also highlighted that the ecophysiology and surrounding levels of TEs influenced in an equivalent manner the bioaccumulation process of TEs in P. oceanica. Consequently, this natural cyclic evolution of TE concentrations should be systematically quantified in regional reference sites. Finally, the rapid and proportionnal accumulation of TEs in P. oceanica traps huge amounts of contaminants and can stock them for longer periods of time in their bellow grounds tissues. P. oceanica meadows therefore play an efficient role of natural filter of TE coastal pollutions. [less ▲]

Detailed reference viewed: 42 (13 ULg)
Full Text
Peer Reviewed
See detailDo large companies ignore formal sustainability management controls? An exploration amongst corporate practices
Crutzen, Nathalie ULg; Schaltegger, Stefan

in EMAN (Ed.) Proceedings of the 2014 EMAN conference (2014, March)

Detailed reference viewed: 67 (6 ULg)
Full Text
Peer Reviewed
See detailContributions to transnational flood risk management in the Meuse basin
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in European Symposium on Flood Frequency Estimation and Implications for Risk Management (2014, March)

Experience in transboundary river basins emphasizes the need for more cooperative transnational water management. In this respect, the Interreg IVB project AMICE aims at developing a shared adaptation ... [more ▼]

Experience in transboundary river basins emphasizes the need for more cooperative transnational water management. In this respect, the Interreg IVB project AMICE aims at developing a shared adaptation strategy of the basin of the river Meuse to the hydrological impacts of climate change. The basin covers parts of France, Belgium, Germany and the Netherlands. The project combines scientific research with innovative natural and structural water retention measures, as well as enhanced transnational crisis management. In this framework, common climate and hydrological scenarios were derived for the time horizons 2021-2050 and 2071-2100. A “coordinated” procedure was set up to conduct the first hydraulic modelling of the entire river Meuse, from its spring to its mouth. For the considered climate scenarios, the increases in future flood levels were found about twice higher in the central part of the Meuse basin compared to the upper and lower parts. This distinctive spatial pattern results from the morphology of the valley. The characteristics of the hydraulic models used for this “coordinated” analysis differed significantly from one region to the other (e.g., 1D vs. 2D, steady vs. unsteady). Therefore, a more refined analysis was undertaken on a 100 km long stretch of the Meuse, crossing the border between Belgium and the Netherlands, using very similar (“harmonized”) models for the whole computation (2D unsteady models). As a result, the influence of using different interconnected models could be appreciated. The results of hydraulic modelling were used to conduct damage assessment based on a common methodology throughout the Meuse basin and combined with landuse change scenarios in the floodplains (change in vulnerability of the floodplains). In turn, several adaptation measures were tested, including upstream water retention, dredging as well as upgrade of flood defences and mobile weirs. Hydrological and hydraulic modelling was also performed for a sub-basin of the river Meuse, partly controlled by two large reservoirs. A detailed model of the operation rules of these reservoirs was implemented. This enabled to investigate the impact of the considered climate change scenarios on the performance of these multi-purpose reservoirs as well as to investigate possible enhancements in the operation rules, which may serve as adaptation measures to compensate for the detrimental effects of climate change. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailRupture et repli sur soi. À propos de quelques traits posturaux de Rousseau dans sa correspondance entre 1762 et 1765
Biquet, Stéphanie ULg

in Francalanza, Eric (Ed.) Actes du colloque international "Rousseau en toutes lettres", Brest 22-24 mars 2012 (2014, March)

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailLearning to Learn: Assessment of Metacognitive competencies
Frenkel, Stéphanie ULg; Nobile, Debora ULg

in IATED (Ed.) INTED2014 Proceedings (2014, March)

Numerous students are having school difficulties linked to the way they learn. Some authors speak of a “metacognitive deficit”. We refer to a “sleeping potential” instead (Frenkel, 2013, in press; Frenkel ... [more ▼]

Numerous students are having school difficulties linked to the way they learn. Some authors speak of a “metacognitive deficit”. We refer to a “sleeping potential” instead (Frenkel, 2013, in press; Frenkel & Deforge, in press; Frenkel & Nobile, 2013). Be it psychologists, teachers or parents, all wish to develop their skills in order to help these students. This is the case in primary and secondary school. Metacognitive abilities play a central role in learning (e.g., Frenkel & Deforge, in press; Giasson, 2001; Grangeat, 1997; Hessels & Hessels-Schlatter, 2010b; Lumbelli, 2003; Poissant, Poëllhuber & Falardeau, 1994; Rozencwajg, 2003; Veenman, Kok & Blöte, 2005) and thus in successful school learning (Büchel, 2013a, 2013b; Van der Stel & Veenman, 2010; Wang, Haertel & Walberg, 1994). However, studying them requires that we clarify what is meant by “metacognition” and “metacognitive abilities”. In this framework, we developed the EDUCA + project which is intended to provide possible solutions. EDUCA + is based on wide field experience. Its theoretical background is based on a substantial review of the literature. Its objective is to increase the expertise of “front line” field workers by developing specific products such as tools, training courses, services, and a website (Frenkel, in press). This will notably enable them to develop their expertise, detect « sleeping » potential, diagnose, give advice when necessary, intervene (prevention and remediation) and use the tools efficiently. Two types of tools are being designed. On the one hand, assessment tools (tests allowing to put forward the learner’s strengths and weaknesses as well as the scope of his/her “sleeping potential”). On the other hand, intervention tools (short prevention vs. remediation programs). This also includes training courses and services. The creation of a website also aims to reinforce the actions of EDUCA + (personalized access depending on the internaut’s profile: students, parents, professionals). The aim of this paper is to present this research project and its main theoretical background. [less ▲]

Detailed reference viewed: 80 (19 ULg)
Full Text
See detail9. Nutrition azotée de l'épeautre en Ardenne et en région limoneuse
Escarnot, Emmanuelle ULg; Meza Morales, Walter ULg; De Toffoli, Marc et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre blanc céréales (2014, February 26)

Detailed reference viewed: 19 (2 ULg)
Full Text
See detail5. Régulateurs de croissande
Meza Morales, Walter ULg; Monfort, Bruno; Mahieu, Olivier et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc Céréales (2014, February 26)

Detailed reference viewed: 9 (1 ULg)
Full Text
See detail6. Lutte intégrée contre les maladies
Duvivier, Maxime; Bataille, Charlotte; Mahieu, Olivier et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre blanc céréales (2014, February 26)

Detailed reference viewed: 16 (4 ULg)
Full Text
See detail4. La fumure azotée
Meza Morales, Walter ULg; Monfort, Bruno; Dumont, Benjamin ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

Detailed reference viewed: 50 (5 ULg)
Full Text
See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Hiel, Marie-Pierre ULg; Meza Morales, Walter ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc Céréales (2014, February 26)

Detailed reference viewed: 14 (5 ULg)
Full Text
See detail3. Lutte contre les mauvaises herbes
Henriet, François; Jaunard, Delphine; Gilleman, Alice ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

Detailed reference viewed: 14 (1 ULg)
Full Text
See detail10. Perspectives - 2. Perspectives offertes par la culture en association de froment et de pois protéagineux d'hiver
Pierreux, Jérome ULg; Delaplace, Pierre ULg; Roisin, Christian et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

Detailed reference viewed: 15 (0 ULg)
Full Text
Peer Reviewed
See detailThe Usability of Green Building Rating Systems in Hot Arid Climates
Attia, Shady ULg

in ASHRAE Energy & Indoor Environment for Hot Climates (2014, February 24)

To develop adaptable and context sensitive building rating systems, the present work aimed to evaluate four rating systems that emerged recently in the Middle East. Literature review and cross comparison ... [more ▼]

To develop adaptable and context sensitive building rating systems, the present work aimed to evaluate four rating systems that emerged recently in the Middle East. Literature review and cross comparison analysis showed that the four examined rating systems namely, Green Pyramid Rating System (Egypt), Green Building Standard SI 5281 (Israel), Qatar Sustainability Assessment System (QSAS) and Pearl Building Rating System (UAE) are not enough adopted to local environmental, cultural, historical, societal and economic context. They showed also a comparable similarity since they all imitate the American LEED and British BREEAM rating systems. The paper elaborates on the comparison results and presents recommendations to improve the questioned rating systems and remind designers with the principles and strategies of sustainable design that goes beyond the existing rating systems in hot climate. The evaluation of the four systems might provide a new approach for regional harmonization among the four systems and the development of adaptable and context sensitive rating system. [less ▲]

Detailed reference viewed: 210 (5 ULg)
Peer Reviewed
See detailInvestigating the Impact of Different Thermal Comfort Models for Zero Energy Buildings in Hot Climates
Attia, Shady ULg; Hensen, JLM

in Proceeding of: Conference on Energy and Indoor Environment for Hot Climates (2014, February 24)

The selection of a thermal comfort model has a major impact on energy consumption of Net Zero Energy Buildings (NZEBs) in hot climates. The objective of this paper is to compare the influence of using ... [more ▼]

The selection of a thermal comfort model has a major impact on energy consumption of Net Zero Energy Buildings (NZEBs) in hot climates. The objective of this paper is to compare the influence of using different comfort models for zero energy buildings in hot climates. The paper compares the impact of applying Givoni’s model, ASHRAE 55 adaptive comfort standard, EN 15251 adaptive comfort standard and EN ISO 7730 on energy consumption and comfort. Using ZEBO and EnergyPlus for energy simulation, an existing prototype of a residential apartment module will be used to evaluate energy performance and thermal comfort in two parametric series. The first one is the result of coupling natural ventilation and mechanical cooling and the second one is guided coupling natural ventilation, mechanical cooling and ceiling fans. Results show a significant difference of cooling loads and total energy generation for the compared comfort models. However, the study remains theoretical and requires post occupancy evaluation for a better reliability of the results. [less ▲]

Detailed reference viewed: 96 (5 ULg)
Full Text
Peer Reviewed
See detailAssessing the Thermal Performance of Bedouin Tents in Hot Climates
Attia, Shady ULg

in ASHRAE Energy & Indoor Environment for Hot Climates (2014, February 24)

The aims of this study it to improve conditions inside Bedouin tents shelters and to develop tools to assess shelter quality and comfort. A prototype tent was tested in hot conditions with an internal ... [more ▼]

The aims of this study it to improve conditions inside Bedouin tents shelters and to develop tools to assess shelter quality and comfort. A prototype tent was tested in hot conditions with an internal vapor load. Temperature, humidity measurements and air speed were taken inside the shelter while the external temperature was maintained at 40°C (104°F). Building performance simulation was conducted to produce a simulation model. A model of a tent was constructed using the EnergyPlus simulation software and were calibrated with the test data. The shelter models were simulated in Wadi Rum, Jordan using real data from. The feasibility of heating the tent using only the casual gains from occupants and solar radiation was investigated, although it was found that a tent heated in this way would only be appropriate in spring and autumn. Design issues included coping with stratification of air temperature inside the tent, improving thermal comfort without compromising fabricating the materials cheaply and simply. The validity of the results is limited by the lack of measured data for rates of air infiltration. [less ▲]

Detailed reference viewed: 94 (3 ULg)
Full Text
Peer Reviewed
See detailStrategic Decision Making For Zero Energy Buildings in Jordan
Attia, Shady ULg; Zawaydeh, Samer

in Proceedings of the 1st International Conference on Energy & Indoor Environment for Hot Climates (2014, February 24)

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Jordanian residential building sector. A representative ... [more ▼]

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Jordanian residential building sector. A representative house prototype, located in Amman is selected as a case study for the zero energy design and performance objective. The aim of the study is to investigate the potential of achieving thermal comfort and delivering thermal and electrical energy demands for existing buildings on site for different Jordanian Cities. Jordan has a semi-arid climate with an annual total irradiation above 2000 bankable kWh/m2 per year with approximately 2000 hours of full sunshine. Therefore, different passive and active design strategies are discussed and compared to reach an annual net zero energy demand for the existing building stock. In order to achieve zero energy buildings certain strategies are examined. For example, internal loads reduction, envelope insulation in addition to the installation of solar water heater and photovoltaic. Based on a month-by–month demand analysis, internal loads and envelope performance are analyzed in order to explore the existing economical potential. Simulation software DesignBuilder is used to examine the strategies proposed to achieve annual net zero energy performance for a prototype. The final result of this study compares the potential and constraints of each strategy and assesses them based on economical feasibility. For the considered location and weather conditions the prototype can provide thermal comfort for occupants and meets the zero energy objectives. The research also proofs that some strategies are cost effective rewarding with a payback period ranging from 3 to 9 years. [less ▲]

Detailed reference viewed: 61 (4 ULg)
Full Text
See detailUtilisation d'une application internet pour quantifier la charge de travail chez le rugbyman de haut niveau
Paulus, Julien ULg; Laly, Arnaud; Guns, Sébastien et al

in Jidovtseff, Boris; Halleux, Philippe; Lambert, Eric (Eds.) Livre des résumés (2014, February 22)

La détection précoce du dépassement (over-reching) (et du syndrôme de surentrainement) est capitale compte-tenu de ses effets négatifs sur la performance. Dans ce processus, le contrôle individuel de la ... [more ▼]

La détection précoce du dépassement (over-reching) (et du syndrôme de surentrainement) est capitale compte-tenu de ses effets négatifs sur la performance. Dans ce processus, le contrôle individuel de la charge d'entrainement du joueur est indispensable. [less ▲]

Detailed reference viewed: 33 (6 ULg)
Full Text
See detail1er Colloque Guy Namurois : Livre des résumés
Jidovtseff, Boris ULg; Halleux, Philippe; Lambert, Eric et al

in Jidovtseff, Boris (Ed.) 1er Colloque Guy Namurois : Livre des résumés (2014, February 22)

Colloque multi-disciplinaire en l'honneur de Guy Namurois

Detailed reference viewed: 42 (10 ULg)
Full Text
Peer Reviewed
See detailLe contrôle moteur lombopelvien du joueur de footbal élite
GROSDENT, Stéphanie ULg; Demoulin, Christophe ULg; Namurois, Guy et al

in Abstarct Book de la 1ère Journée Guy Namurois (2014, February 22)

Detailed reference viewed: 24 (3 ULg)
Full Text
See detailPathologies des bétons: causes et effets
Courard, Luc ULg

in Evaluation des structures en béton (2014, February 20)

Detailed reference viewed: 44 (3 ULg)
Peer Reviewed
See detailLes herbivores, transformateurs de produits fourragers et de coproduits issus de l'agro-industrie en aliments nobles pour l'homme
Decruyenaere, Virginie; Lessire, Françoise ULg; Beckers, Yves ULg et al

in CRA-W (Ed.) La viande bovine remise en question: De sa production à sa consommation (2014, February 19)

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour ... [more ▼]

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour celles-ci bien souvent, les sommes de température et la durée de végétation active sont faibles et limitent considérablement le choix des cultures susceptibles d’atteindre la maturité avant récolte avec certitude. Dans d’autres régions, les prairies s’imposent davantage en raison de contraintes agronomiques : nature du sol, disposition des parcelles, relief du territoire, intérêt dans la rotation pour les prairies temporaires… Ainsi, la grande majorité des prairies de notre Région ne peut pas être remplacée par des cultures ; elles doivent dès lors être perçues comme une bonne alternative à la valorisation du territoire. Grâce à la présence du rumen en amont de l’estomac, les ruminants ont la capacité de transformer des productions non éligibles pour l’homme, tels que les fourrages et les co-produits des industries agro-alimentaires. Ces aliments, de nature essentiellement fibreuse mais pas pour autant pauvres en protéine et en énergie, sont largement fermentés par les micro-organismes du rumen qui les dégradent en composés plus simples, valorisables ensuite par l’animal. Par ce mécanisme, les ruminants contribuent à transformer ces aliments grossiers en produits nobles, tels que le lait et la viande. On comprend dès lors aisément que la présence des ruminants est étroitement liée aux superficies enherbées, elles-mêmes dépendantes des conditions pédo-climatiques d’une région. Malgré des systèmes de production intensifs et l’amélioration continue du potentiel génétique des animaux, les bovins restent peu dépendants des aliments du commerce comparativement aux autres spéculations animales. Ainsi, selon l’APFACA, de l’ordre de 16% des aliments composés produits en Belgique et importés sont utilisés pour les bovins, dont seulement 1/3 est écoulé dans la filière viande bovine. L’herbe, les produits herbagers et les aliments produits sur l’exploitation tels que le maïs restent donc majoritaires dans la ration des bovins élevés pour la production de viande. La valorisation de l’herbe et des produits herbagers dépend fortement des performances zootechniques recherchées. Les objectifs de croissance sont établis, en autre, sur base des prix offerts par la cheville variant avec les catégories d’âge et de poids d’abattage. Ces dernières années, il semble que les animaux abattus un peu plus tardivement soient moins dépréciés qu’auparavant, facilitant la formulation de rations à base de matières premières herbagères. A l’inverse, l’intensification dans le but de produire des animaux abattus plus jeunes ou à un poids supérieur, implique une croissance plus soutenue, et de ce fait la distribution de rations plus denses en énergie. Pour la formulation de telles rations, certains coproduits disposent de valeurs nutritionnelles intéressantes, permettant de satisfaire des besoins nutritionnels élevés, tout en conservant une certaine autonomie alimentaire. Leur valorisation au niveau local représente en outre un intérêt considérable pour la rentabilité des industries agro-alimentaires qui, sans la présence de l’animal, devraient trouver d’autres débouchés pour les coproduits sous peine d’être dans l’obligation de financer leur élimination. Cet exposé a pour objectif d’illustrer les potentiels, mais aussi les limites, des aliments produits localement pour les bovins viande, que ce soit selon leur type (vache de réforme- taurillon…), leur race et leurs performances zootechniques, mais aussi l’intérêt de ces aliments en termes d’efficiences alimentaire et économique. Il analyse les atouts et faiblesses de la spéculation viande bovine en ne se limitant pas à l’échelle de l’animal seul, mais en le replaçant en tant que véritable maillon de la chaîne agro-alimentaire. Ce positionnement permet non seulement de mieux cerner les enjeux de ces élevages au niveau de la production primaire, mais aussi leur importance dans les secteurs amont et aval. [less ▲]

Detailed reference viewed: 24 (2 ULg)
Peer Reviewed
See detailLes herbivores, transformateurs de produits fourragers et de coproduits issus de l'agro-industrie en aliments nobles pour l'homme
Decruyenaere, Virginie; Lessire, Françoise ULg; Beckers, Yves ULg et al

in CRA-W (Ed.) La viande bovine remise en question: De sa production à sa consommation (2014, February 19)

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour ... [more ▼]

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour celles-ci bien souvent, les sommes de température et la durée de végétation active sont faibles et limitent considérablement le choix des cultures susceptibles d’atteindre la maturité avant récolte avec certitude. Dans d’autres régions, les prairies s’imposent davantage en raison de contraintes agronomiques : nature du sol, disposition des parcelles, relief du territoire, intérêt dans la rotation pour les prairies temporaires… Ainsi, la grande majorité des prairies de notre Région ne peut pas être remplacée par des cultures ; elles doivent dès lors être perçues comme une bonne alternative à la valorisation du territoire. Grâce à la présence du rumen en amont de l’estomac, les ruminants ont la capacité de transformer des productions non éligibles pour l’homme, tels que les fourrages et les co-produits des industries agro-alimentaires. Ces aliments, de nature essentiellement fibreuse mais pas pour autant pauvres en protéine et en énergie, sont largement fermentés par les micro-organismes du rumen qui les dégradent en composés plus simples, valorisables ensuite par l’animal. Par ce mécanisme, les ruminants contribuent à transformer ces aliments grossiers en produits nobles, tels que le lait et la viande. On comprend dès lors aisément que la présence des ruminants est étroitement liée aux superficies enherbées, elles-mêmes dépendantes des conditions pédo-climatiques d’une région. Malgré des systèmes de production intensifs et l’amélioration continue du potentiel génétique des animaux, les bovins restent peu dépendants des aliments du commerce comparativement aux autres spéculations animales. Ainsi, selon l’APFACA, de l’ordre de 16% des aliments composés produits en Belgique et importés sont utilisés pour les bovins, dont seulement 1/3 est écoulé dans la filière viande bovine. L’herbe, les produits herbagers et les aliments produits sur l’exploitation tels que le maïs restent donc majoritaires dans la ration des bovins élevés pour la production de viande. La valorisation de l’herbe et des produits herbagers dépend fortement des performances zootechniques recherchées. Les objectifs de croissance sont établis, en autre, sur base des prix offerts par la cheville variant avec les catégories d’âge et de poids d’abattage. Ces dernières années, il semble que les animaux abattus un peu plus tardivement soient moins dépréciés qu’auparavant, facilitant la formulation de rations à base de matières premières herbagères. A l’inverse, l’intensification dans le but de produire des animaux abattus plus jeunes ou à un poids supérieur, implique une croissance plus soutenue, et de ce fait la distribution de rations plus denses en énergie. Pour la formulation de telles rations, certains coproduits disposent de valeurs nutritionnelles intéressantes, permettant de satisfaire des besoins nutritionnels élevés, tout en conservant une certaine autonomie alimentaire. Leur valorisation au niveau local représente en outre un intérêt considérable pour la rentabilité des industries agro-alimentaires qui, sans la présence de l’animal, devraient trouver d’autres débouchés pour les coproduits sous peine d’être dans l’obligation de financer leur élimination. Cet exposé a pour objectif d’illustrer les potentiels, mais aussi les limites, des aliments produits localement pour les bovins viande, que ce soit selon leur type (vache de réforme- taurillon…), leur race et leurs performances zootechniques, mais aussi l’intérêt de ces aliments en termes d’efficiences alimentaire et économique. Il analyse les atouts et faiblesses de la spéculation viande bovine en ne se limitant pas à l’échelle de l’animal seul, mais en le replaçant en tant que véritable maillon de la chaîne agro-alimentaire. Ce positionnement permet non seulement de mieux cerner les enjeux de ces élevages au niveau de la production primaire, mais aussi leur importance dans les secteurs amont et aval. [less ▲]

Detailed reference viewed: 24 (2 ULg)
Full Text
Peer Reviewed
See detailPaints based on renewable materials
Olive, Gilles ULg; Richel, Aurore ULg

in BOOK OF SHORT ABSTRACTS - POSTER PRESENTATIONS 19TH NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES (2014, February 07)

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming ... [more ▼]

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming material, diluted in solvents. Pigments are solid particles, used to give opacity and/or color. Today almost all pigments have a synthetic origin. The fillers are often natural compounds. Unlike pigments, fillers have low opacity and are colorless. These very cheap products achieve the required solid content under satisfactory economic conditions. Resins used in paints have the property of forming a continuous solid (hard or flexible) film under specific conditions. They are often called “resins”. They can be solid or liquid at room temperature. The solvents are used to control the viscosity of the paint in order to facilitate its production and application. The solvents used are volatile compounds. Additives are minor compounds (a few percent), whose function is to either promote or prevent some developments of the product. For example, surfactants improve the homogeneity of the dispersion. Some additives protect the film against mold or ultraviolet radiation, or against the formation of free radicals under the action of sunlight. Since the end of the 18th century most of those paints are petroleum-based. But the near disappearance of the petroleum causes a renewed interest in bio-based preparations. In this communication, we present an overview of bio-based alternatives. [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailOld inks: pigments extracted from plants
Despy, Jessica; Wymeersch, Noémie; Bouchat, Isabelle et al

in BOOK OF SHORT ABSTRACTS - POSTER PRESENTATIONS 19TH NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES (2014, February 07)

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A ... [more ▼]

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles. Pigments and dyes can be classified into two broad categories and five families: natural pigments and dyes and those called artificial. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue) and madder (red) compose the second family and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the third family. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. We report the extraction of pigments from plants. [less ▲]

Detailed reference viewed: 27 (5 ULg)
See detailExtensive spectroscopic and photometric study of HD 25558, a long orbital-period binary with two SPB components
Sódor, Á.; De Cat, P.; Wright, D. J. et al

in IAU Symposium (2014, February 01)

We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at ... [more ▼]

We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at 13 observatories during 5 observing seasons, the ground-based multi-colour light curves and the photometric data from the MOST satellite revealed that this object is a double-lined spectroscopic binary with a very long orbital period of about 9 years. We determined the physical parameters of the components, and have found that both lie within the SPB instability strip. Accordingly, both components show line-profile variations consistent with stellar pulsations. Altogether, 11 independent frequencies and one harmonic frequency were identified in the data. The observational data do not allow the inference of a reliable orbital solution, thus, disentangling cannot be performed on the spectra. Since the lines of the two components are never completely separated, the analysis is very complicated. Nevertheless, pixel-by-pixel variability analysis of the cross-correlated line profiles was successful, and we were able to attribute all the frequencies to the primary or secondary component. Spectroscopic and photometric mode-identification was also performed for several of these frequencies of both binary components. The spectroscopic mode-identification results suggest that the inclination and rotation of the two components are rather different. While the primary is a slow rotator with ~6 d rotation period, seen at ~60° inclination, the secondary rotates fast with ~1.2 d rotation period, and is seen at ~20° inclination. Our spectropolarimetric measurements revealed that the secondary component has a magnetic field with at least a few hundred Gauss strength, while no magnetic field was detected in the primary. The detailed analysis and results of this study will be published elsewhere. [less ▲]

Detailed reference viewed: 7 (0 ULg)