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See detailVers une généralisation des quartiers durables ? Présentation du référentiel d’aide à la conception et à l’évaluation développé en Wallonie et analyse prospective de douze quartiers.
Marique, Anne-Françoise ULg; Delbar, Caroline; Loiseau, Véronique ULg et al

in Urbia (2015)

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

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

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See detailFair Trade and Social Enterprise
Huybrechts, Benjamin ULg

in Raynolds, Laura; Bennett, Elizabeth (Eds.) The Handbook of Research on Fair Trade (2015)

This chapter suggests that the notion of ‘social enterprise’ is useful to capture the DNA of organizations focused on fair trade and to locate them within a broader organizational taxonomy. Without ... [more ▼]

This chapter suggests that the notion of ‘social enterprise’ is useful to capture the DNA of organizations focused on fair trade and to locate them within a broader organizational taxonomy. Without seeking to impose a new term that may not resonate for certain actors or regions, this chapter aims to bring two contributions to fair trade research and practice. First, it is suggested that the social enterprise approach is particularly useful as an analytical tool enabling researchers and other stakeholders to capture the evolution and diversification of organizational models in fair trade. Second, the use of a broader organizational approach that is not specific to the sole fair trade sector allows for connections with similar organizations in other sectors and brings a shift from considering mainly what the organizations do (fair trade in this case) towards also addressing what they are (innovative social enterprise models combining market dynamics with social purpose). This chapter is structured as follows. First, the concept of social enterprise is introduced and discussed. Then, the evolution of the organizational landscape of fair trade (in the North) is summarized. Finally, fair trade organizations are examined in the light of the social enterprise concept, with illustrations from a study in four European countries (Huybrechts 2010a; 2012). [less ▲]

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See detailPolitiques de la littérature : Sartre, Bourdieu, Foucault
Bolmain, Thomas ULg; Cormann, Grégory ULg

Book published by Presses Universitaires de Liège (2015)

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See detailQuantitative temperature monitoring of a heat tracing experiment using cross-borehole ERT
Hermans, Thomas ULg; Wildemeersch, Samuel ULg; Jamin, Pierre ULg et al

in Geothermics (2015), 53

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

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

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See detailThe sentence repetition task: A powerful diagnostic tool for French children with specific language impairment
Leclercq, Anne-Lise ULg; Quémart, Pauline; Magis, David ULg et al

in Research in Developmental Disabilities (2014), 35

This study assesses the diagnostic accuracy and construct validity of a sentence repetition task that is commonly used for the identification of French children with specific language impairment (SLI ... [more ▼]

This study assesses the diagnostic accuracy and construct validity of a sentence repetition task that is commonly used for the identification of French children with specific language impairment (SLI). Thirty-four school-aged children with a confirmed, diagnostically based diagnosis of SLI, and 34 control children matched on age and nonverbal abilities performed the sentence repetition task. Two general scoring measures took into account the verbatim repetition of the sentence and the number of words accurately repeated. Moreover, five other scoring measures were applied to their answers in order to separately take into account their respect of lexical items, functional items, syntax, verb morphology, and the general meaning of the sentence. Results show good to high levels of sensitivity and specificity at the three cut-off points for all scoring measures. A principal component analysis revealed two factors. Scoring measures for the respect of functional words, syntax and verb morphology provided the largest loadings to the first factor, while scoring measures for the respect of lexical words and general semantics provided the largest loadings to the second factor. Sentence repetition appears to be a valuable tool to identify SLI in French children, and the ability to repeat sentences correctly is supported by two factors: a morphosyntactic factor and a lexical factor. [less ▲]

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See detailToward a tool aimed to quantify soil compaction risks at a regional scale: application to Wallonia (Belgium)
D'Or, Dimitri; Destain, Marie-France ULg

in Soil & Tillage Research (2014), 144

The spatial analysis of the soil compaction risk has been developed at the regional level and applied to Wallonia (Belgium). The methodology is based on the estimation of the probability of exceeding the ... [more ▼]

The spatial analysis of the soil compaction risk has been developed at the regional level and applied to Wallonia (Belgium). The methodology is based on the estimation of the probability of exceeding the preconsolidation stress due to the application of loads on the soil. Preconsolidation stresses (Pc) are computed from the pedotransfer functions of Horn and Fleige (2003) at pF 1.8 and 2.5 and classified into 6 categories ranging from very low Pc (< 30 kPa) to extremely high Pc (> 150 kPa). The computation requires the knowledge of pedological (texture, organic content), mechanical (bulk density, cohesion, internal friction angle), and hydraulic variables (water content available, non-available water content, air capacity, saturated hydraulic conductivity). These variables are obtained from databases like HYPRES or AARDEWERK or from pedotransfer functions. The computation of Pc takes into account the spatial structure of the data: in some cases, data are abundant (e.g. texture data) and spatial variability is taken into account through geostatistical methods. In other cases, the data is sparse but uncertainty information can be extracted from the knowledge of the statistical distribution. Maps of the most probable Pc class are produced. Uncertainty is computed as the classification error probability. Implementation of these methods in Wallonia showed that Pc values higher than 120 kPa are reached either on 64 % of the territory at pF 2.5 or on 55 % at pF 1.8. A higher uncertainty was found at pF 2.5 than at pF 1.8. Uncertainty was also found higher for clay and clayed loess than for other textural classes present in Wallonia. The risk of compaction is defined as the probability that Pc is exceeded by the stress created by a load applied to the soil at a depth of 40 cm, the loads being similar to those induced by agricultural or forestry tires. It appeared that subsoil compaction risks exist mainly in loamy forest soils with small coarse fragments supporting loads similar to that existing on logging machines. In the zones where the uncertainty is low, the developed tool could be used as a basis for providing policy measures in order to promote soil-friendly farming and forest practices. [less ▲]

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See detailSur les définitions de Dieu. Entretien avec Valère Novarina
Dubouclez, Olivier ULg; Novarina, Valère

in Littérature (2014)

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See detailAn inverse modelling approach to estimate the hygric parameters of clay-based masonry during a Moisture Buffer Value test
Dubois, Samuel ULg; McGregor, Fionn; Evrard, Arnaud et al

in Building & Environment (2014), 81

This paper presents an inverse modelling approach for parameter estimation of a model dedicated to the description of moisture mass transfer in porous hygroscopic building materials. The hygric behaviour ... [more ▼]

This paper presents an inverse modelling approach for parameter estimation of a model dedicated to the description of moisture mass transfer in porous hygroscopic building materials. The hygric behaviour of unfired clay-based masonry samples is specifically studied here and the Moisture Buffer Value (MBV) protocol is proposed as a data source from which it is possible to estimate several parameters at once. Those include materials properties and experimental parameters. For this purpose, the mass of two clay samples with different compositions is continuously monitored during several consecutive humidity cycles in isothermal conditions. Independently of these dynamic experimental tests, their moisture storage and transport parameters are measured with standard steady-state methods. A simple moisture transfer model developed in COMSOL Multiphysics is used to predict the moisture uptake/release behaviour during the MBV tests. The set of model parameters values that minimizes the difference between simulated and experimental results is then automatically estimated using an inverse modelling algorithm based on Bayesian techniques. For materials properties, the optimized parameters values are compared to values that were experimentally measured in steady state. And because a precise understanding of parameters is needed to assess the confidence in the inverse modelling results, a sensitivity analysis of the model is also provided. [less ▲]

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See detailThe Airline Container Loading Problem with Pickup and Delivery
Lurkin, Virginie ULg; Schyns, Michael ULg

Conference (2014, October 19)

The present paper looks into the problem of optimizing the loading of a set of containers and pallets into cargo aircraft serving multiple airports. Due to the pickup and delivery operations occurring at ... [more ▼]

The present paper looks into the problem of optimizing the loading of a set of containers and pallets into cargo aircraft serving multiple airports. Due to the pickup and delivery operations occurring at intermediate airports, this problem is simultaneously a weight and balance problem and a sequencing problem. Our objective is to minimize fuel and handling operations costs. This problem is shown to be NP-hard. We resort to a mixed integer linear program. On the basis of a professional partner's real-world data, TNT Airways, we perform numerical experiments using a standard B&C library. This approach yields better solutions than traditional manual planning, which results in substantial cost savings. [less ▲]

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See detailKnowledge transfer from Belgian government to medical doctors
MORTELMANS, Katrien; REMMEN, Roy; BERKEIN, Philip et al

Conference (2014, October 02)

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See detailUnderstanding Random Forests: From Theory to Practice
Louppe, Gilles ULg

Doctoral thesis (2014)

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

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

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See detailOptimal Assignment of Off-Peak Hours to Lower Curtailments in the Distribution Network
Merciadri, Luca ULg; Mathieu, Sébastien ULg; Ernst, Damien ULg et al

in Proceedings of the 5th European Innovative Smart Grid Technologies (ISGT) (2014, October)

We consider a price signal with two settings: off-peak tariff and on-peak tariff. Some loads are connected to specific electricity meters which allow the consumption of power only in off-peak periods ... [more ▼]

We consider a price signal with two settings: off-peak tariff and on-peak tariff. Some loads are connected to specific electricity meters which allow the consumption of power only in off-peak periods. Historically, off-peak periods were located during the night and on-peak periods during the day. Changing the assignment of off-peak periods is an easy method for distribution system operators to access to the flexibility of small consumers. This solution can be implemented quickly as the infrastructure needed already exists in some countries. We propose a mixed-integer linear model to assign optimally the off-peak hours so as to minimize a societal cost. This cost gathers together the cost of electricity, the financial losses due to energy curtailments of photovoltaic installations and the loads' wellbeing. Our model considers automatic tripping of inverters and constraints of the electrical distribution networks. Simulation results show that the new disposition of off-peak hours could reduce significantly the photovoltaic energy curtailed in the summer. [less ▲]

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See detailPrevenção Quaternária e limites em medicina
Jamoulle, Marc ULg; Gomes, Luis

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

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

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

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See detail9th Congress of the International Society of NeuroImmunoModulation (ISNIM)
Geenen, Vincent ULg

Scientific conference (2014, September 25)

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See detailModélisation et étude expérimentale du comportement de Saccharomyces cerevisiae (boulardii) lors de l'extrapolation du procédé à des bioréacteurs de volume industriel
Lejeune, Annick ULg

Doctoral thesis (2014)

L’extrapolation de la production d’un microorganisme est un problème complexe qui prend en compte de nombreux paramètres. En effet, les paramètres opératoires induisent des conditions environnementales ... [more ▼]

L’extrapolation de la production d’un microorganisme est un problème complexe qui prend en compte de nombreux paramètres. En effet, les paramètres opératoires induisent des conditions environnementales qui peuvent être dommageables pour les cellules se développant dans le réacteur. Il est donc important de prendre en compte le côté génie chimique pour comprendre quelles sont les conditions hydrodynamiques présentes dans le réacteur et ensuite s’attacher à étudier la réponse des cellules vis-à-vis de ces conditions. Ce travail se place dans le cas particulier de la production de biomasse de Saccharomyces cerevisiae (boulardii). Dans ce cas, le point critique est l’ajout de la solution concentrée de substrat dans le réacteur. L’utilisation de réacteurs scale-down a permis d’étudier différents cas de conditions hydrodynamiques défavorables, ainsi que leurs impacts sur différents paramètres. Dans un premier temps, l’étude des paramètres ségrégés (concentration en biomasse, en co-produits…) a montré, notamment, une diminution du rendement et une augmentation de la concentration en éthanol. Ensuite, l’étude s’est placée au niveau cellulaire avec l’utilisation de souches exprimant une protéine recombinante fluorescente et de marqueurs cellulaires fluorescents, couplée à la cytométrie en flux. Ces techniques ont permis de mettre en évidence la présence de différentes sous-populations cellulaires, ainsi que l’apparition du phénomène de résistance cellulaire aux stress lors de la production en réacteurs scale-down. L’importance du choix de la méthode de traitement des données cytométriques a également été débattue. Ce travail a abordé différents domaines pour tenter de mieux comprendre la réponse cellulaire aux fluctuations des conditions environnementales ressenties par Saccharomyces cerevisiae (boulardii) lors de productions en réacteurs mimant les conditions hydrodynamiques des réacteurs de grands volumes. [less ▲]

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See detailTransnational Health Insurance Schemes: A New Avenue for Congolese Immigrants in Belgium to Care for Their Relatives’ Health from Abroad?
Lafleur, Jean-Michel ULg; Lizin, Olivier

Scientific conference (2014, September 19)

What can immigrants do for non-migrant relatives in their home country who need healthcare they cannot afford? To answer this question, we first examine four existing methods that can be found in the ... [more ▼]

What can immigrants do for non-migrant relatives in their home country who need healthcare they cannot afford? To answer this question, we first examine four existing methods that can be found in the existing literature: mobility, remittances, workers’ health insurance and diasporic health insurance. In the second part of the paper, we discuss an innovative strategy called “transnational health insurance” (THI). These insurance schemes are set up by immigrants in cooperation with a multitude of actors including health insurance companies in destination countries and healthcare providers in countries origin. THIs offer health coverage to non-migrant relatives in the home country based on a premium paid directly by immigrants to the insurance company in their country of residence. Analyzing the creation and implementation of Belgian-Congolese THIs, we discuss the strengths and weaknesses of these schemes in responding to the needs of both immigrants and their non-migrant relatives. The article concludes with a discussion on the specificities of THIs as hybrid forms of remittances. [less ▲]

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See detailHuman cortical excitability depends on time spent awake and circadian phase
Ly, Julien ULg; Chellappa, Sarah Laxhmi ULg; Gaggioni, Giulia ULg et al

Conference (2014, September 17)

At any point in time, human performance results from the interaction of two main factors: a circadian signal varying with the time of the day and the sleep need accrued throughout the preceding waking ... [more ▼]

At any point in time, human performance results from the interaction of two main factors: a circadian signal varying with the time of the day and the sleep need accrued throughout the preceding waking period. But what’s happen at the cortical cerebral level? We used a novel technique coupling transcranial magnetic stimulation with electroencephalography (TMS/EEG) to assess the influence of time spent awake and circadian phasis on human cortical excitability. Twenty-two healthy young men underwent 8 TMS/EEG sessions during a 28 hour sleep deprivation protocole. We found that cortical excitability depends on both time spent awake and circadian phasis. [less ▲]

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See detailScriptorium, a retro-cataloguing tool to easily and quickly encode older book items
Renaville, François ULg; Danhieux, Sylvain ULg

Conference (2014, September 16)

The University of Liège Library's books collection is composed of some 2,000,000 print volumes, of which only 60% are catalogued. Most of the uncatalogued books have been published before 1970 and ... [more ▼]

The University of Liège Library's books collection is composed of some 2,000,000 print volumes, of which only 60% are catalogued. Most of the uncatalogued books have been published before 1970 and cataloguing these according usual standards and norms would certainly take decades. To decrease the cost of treatments and increase the number of catalogued volumes, the Library developed a light PHP/MySQL application, Scriptorium, that enables non-catalogers (mostly students) to quickly encode the books (ca 3 min. per item) by providing the most essential information. References are then daily exported in MarcXML to the ILS. Scriptorium has been developed to permit to easily create new independent instances for different parallel retro-cataloguing projects and also to be used by other libraries. [less ▲]

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