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See detailHow to correctly determine the kinetics of a photocatalytic degradation reaction?
Pirard, Sophie ULg; Malengreaux, Charline ULg; Toye, Dominique ULg et al

in Chemical Engineering Journal (2014), 249

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

Conference (2014, July 22)

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

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

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

Conference (2014, July 07)

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

Conference (2014, July)

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

Conference (2014, July)

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See detailValidation of a new automatic drowsiness quantification system for drivers
Wertz, Jérôme ULg; François, Clémentine ULg; Verly, Jacques ULg

Poster (2014, July)

Drowsiness is a major cause of various types of accidents, and particularly of driving accidents. Scientific studies report that drowsiness would be responsible for 20 to 30% of driving accidents ... [more ▼]

Drowsiness is a major cause of various types of accidents, and particularly of driving accidents. Scientific studies report that drowsiness would be responsible for 20 to 30% of driving accidents. Drowsiness can result from, among others, sleep deprivation, sleep disorders, alcohol, some medications, or performing a monotonous task. While all persons are likely to be drowsy at some point during the day, some persons are more prone than others to being drowsy at almost any time of the day; e.g. 6 to 11% of the population suffers from severe chronic excessive daytime sleepiness. Three main classes of methods can be used to characterize the level of drowsiness of a driver without disturbing him. These classes are respectively related to vehicle behavior (e.g. via lateral movements), driver behavior (e.g. via steering wheel movements), and driver physiological state (e.g. via eye movements). Since drowsiness is a physiological state, it seems particularly meaningful to use physiology-based methods to characterize it. Among these, the most significant ones rely on polysomnography and/or oculography. Polysomnography is viewed by some practitioners as the reference in the domain, but it is very sensitive to artifacts, and it is not very practical for use while driving. Ocular parameters are recognized to be good and reliable physiological indicators of drowsiness, and, thus, oculography seems to be the most sensible way to characterize drowsiness in practice. We have thus developed an experimental, fully automatic drowsiness monitoring system (software/algorithms) based on the physiological state of a person. This system uses ocular parameters extracted from images of the eye (i.e. photooculography) to determine a level of drowsiness on a continuous numerical scale from 0 to 10, with 0 corresponding to "very awake" (or "very vigilant") and 10 to "very drowsy". The ultimate goal of this system is to prevent drowsiness-related accidents for driving and other applications. The reported study shows that our system exhibits promising capability for road safety. Fourteen healthy volunteers (7 M, 7 F, mean age 23.7, range 21-33 years) participated in an experiment in a driving simulator, where they were asked to perform three driving sessions/runs (two of 45 minutes and one of 60 minutes) in different sleep-deprivation conditions (with up to 28 hours of complete sleep deprivation). During each session, we recorded both a high frame rate video of one eye and a set of driving parameters. Subsequently, for each successive minute in the session, we used our algorithms to extract ocular parameters from the video images and to produce a level of drowsiness, and we computed the standard deviation of lateral position (SDLP) from the driving parameters. The results show (1) that the (computed) SDLP increases when the (computed) level of drowsiness increases, and (2) that the level of drowsiness increases when the level of sleep deprivation increases. These results indicate that our algorithms for producing a level of drowsiness work in a meaningful way. The experiment protocol was approved by the Ethics Committee of our university. [less ▲]

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See detailEnhancement of ray tracing method for radiative heat transfer with new isocell quasi-monte carlo technique and application to EUI space instrument
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Proceedings of the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, HEFAT2014 (2014, July)

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical ... [more ▼]

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical engineering especially for space structure design but not yet often for thermal analysis of these structures. Based on Nusselt’s analogy, the ray direction sampling is done by sampling the unit disc to derive the ray directions. Stratified sampling is applied to the unit disc that is divided into cells or strata into which random points are generated. The isocell method relies on cells that have the particularity of presenting almost the same area and shape. This enhances the uniformity of the generated quasi-random sequence of ray directions and leads to faster convergence. The isocell method is associated with different surface sampling to derive REFs. The method is benchmarked against ESARAD, the standard ray tracing engine of the thermal analysis software 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 presented. The EUI instrument of the Solar Orbiter European Space Agency mission and will be launched in a 0.28 perihelion orbit around the Sun in 2018. [less ▲]

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See detailOptimization Of A Heat Pump For Satellite Cooling
Bell, Ian ULg; Lemort, Vincent

in 15 th International Refrigeration and Air Conditioning Conference at Purdue (2014, July)

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See detailRisk assessment of soil compaction in Walloon Region
D'Or, Dimitri; Destain, Marie-France ULg

in Proceedings of geoENV2014 (2014, July)

It is well established that soil compaction affects the growth and functioning of roots and disrupts the activity of microfauna and soil microorganisms, resulting in a loss of yields. Agriculture and ... [more ▼]

It is well established that soil compaction affects the growth and functioning of roots and disrupts the activity of microfauna and soil microorganisms, resulting in a loss of yields. Agriculture and forestry using increasingly heavy machines, the risk of soil compaction is increasing accordingly. Chosen as indicator of the susceptibility of soils to compaction, the precompression stress (Pc) is calculated using the pedotransfer functions (PTFs) proposed by Horn and Fleige (2003). These PTFs involve eight parameters linked to the hydraulic and mechanical behaviour of soils: organic matter content, bulk density, air capacity, available and non-plant available water capacity, saturated hydraulic conductivity, cohesion and angle of internal friction. The challenge consists in producing Pc maps at the regional scale for Wallonia. Those maps should also be accompanied by estimation uncertainty map. Finally, the results should be exploited to produce compaction risk maps according to various frequent scenarios. In this paper, a methodology is proposed, combining geostatistics and Monte Carlo simulations, to achieve these goals. [less ▲]

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

Conference (2014, July)

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

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

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See detailComputation of damped nonlinear normal modes with internal resonances: a boundary value approach
Renson, Ludovic ULg; Touzé, Cyril; Kerschen, Gaëtan ULg

in Proceedings of the 8th European Nonlinear Dynamics Conference (ENOC 2014) (2014, July)

This paper considers the computation of nonlinear normal modes (NNMs) defined as two-dimensional manifolds in phase space. Because existing methods use explicit manifold parameterization, NNM computation ... [more ▼]

This paper considers the computation of nonlinear normal modes (NNMs) defined as two-dimensional manifolds in phase space. Because existing methods use explicit manifold parameterization, NNM computation in the presence of internal resonances requires multiple pairs of constraint coordinates. This paper investigates an alternative method for which the manifold is computed using successive boundary value problems. [less ▲]

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See detailLe TAT de Adolf Eichmann
Peralta, Alberto; Kramer, Richard; Stassart, Martine ULg

in Szondiana (2014)

Under consideration of three major personality tests (TAT, Rorschach, Szondi), it appears that Adolf Eichmann chiefdirector for the deportation of jewish people from 1942 to 1945 was no common individual ... [more ▼]

Under consideration of three major personality tests (TAT, Rorschach, Szondi), it appears that Adolf Eichmann chiefdirector for the deportation of jewish people from 1942 to 1945 was no common individual but a perverse sadomasochistic one with schizoparanoïd features under an osessionnal mask. These data contradict the famous opinion of Hannah Arendt about the "banality of evil". [less ▲]

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

Conference (2014, July)

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

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

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See detailLes botanistes verviétois au XIXème siècle : les Fleurs...du Mal
Genin, Vincent ULg

Conference (2014, June 28)

Detailed reference viewed: 26 (5 ULg)
See detailIslamic religion and food practices in migration context: negotiating belonging and performing subjectivities
Mescoli, Elsa ULg

Scientific conference (2014, June 17)

My paper focuses on the ethnographic material collected during a doctoral research around the culinary practices of Moroccan women living in the city of Sesto San Giovanni (in Milan hinterland, Italy). In ... [more ▼]

My paper focuses on the ethnographic material collected during a doctoral research around the culinary practices of Moroccan women living in the city of Sesto San Giovanni (in Milan hinterland, Italy). In particular, adopting a praxeological approach to subjectivation (Warnier 2001), I will highlight those aspects of the materiality that I studied which recall the belonging of the considered women to Islamic religion. In fact, everyday food consumption (or that related to specific events) and the very same preparation of recipes, are influenced not only by the prescriptions concerning licit and illicit food, but also by the suggestions regarding food which are appropriate to eat. On the one hand, Islamic norms prohibit some food to believers, such as certain meats because of the animal species or the category of victims (Benkheira 1997) to which they belong. Nevertheless, Muslim women behaviours concerning meat consumption are various, such as those of my informants, who in some cases demonstrate to negotiate such norms in order to materially shape a specific self interacting with different collective belongings. On the other hand, some Quranic verses and some sayings of the prophet Muhammad, define a soul food (Rouse and Hoskin 2004), by suggesting to believers what to eat to perform their piety: the preparation and the consumption of some food – and not only the abstention from it – finds in fact religious reasons. In order to follow such suggestions, in a context where Islamic religion is not the majority one, women has to deal with local rules while performing the materiality of some rituals. Religion and traditions intertwine and they shape specific knowledge and savoir-faire which are negotiated by the women considered so as to affirm their various belongings and to face the constraints which the new lived context imposes to them. Such constraints oblige a form of reflexivity on religious norms and rites (Højbjerg 2002), in order to define a limit beyond which modifications are perceived as subtractions of sense (Dore 2001). In my paper, I will try to give some ethnographic examples of these forms of reflexivity and to show how these dynamics constitute the materiality upon which and with which the women considered define their subjectivity. To support my reflexions, I will use visual materials such as photos and videos, which will witness the material density of these facts. [less ▲]

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See detailMeasuring the body, measuring through the body
Vangeebergen, Thomas ULg

Conference (2014, June 13)

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a ... [more ▼]

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a complex technology, an apparatus for the users. A specific body is presented in this paper: the measured body. Trough racial anthropology, sport performances, demographic statistics, medical treatments, psycho-cognitive surveys, quantified self, or in many other contexts, human body is subject to a wide range of various measures. I would on my own propose some thoughts grounded on field exploration, concerning sensory analysis practices, in various laboratories. According to the symmetrical glaze STS have gave from the beginning to both human and non-humans, objects and subjects, the body is for a start itself one of the “stuffs” overlapping categories, blurring distinctions between things and persons, at the same a time a given and an object to perform. The measures of the body, and made with/through the body, highlight how it could be enacted, revealed, understood, improved by technology, especially when it requires some quantitative data. But it allows us also to grasp how the body is viewed simultaneously as a technological device and as the data origin, to intervene during complex practices (e.g. standardization, lab experiments, and marketing surveys). One of the numerous outcomes of such research could be the role of these bodily measurements in the definition of the actors, as well individuals than collectives. By the way it takes on a share on the network tying body to numerical data and to materiality-other-than-human, to measure the body/ through the body seems to afford socio-materiality in a particularly productive manner. Many scholars have inquired about numbers, how they could bring objectivity, how they produce confidence and security, and how finally they participate to black-box the measures themselves. Here, the aim is to understand the specificity of the body as measurement issue, being the interface of the-objects-to-be-measured and the instrument-of-measure. [less ▲]

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