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See detailA Brief Review of Ultraviolet Auroral Emissions on Giant Planets
Grodent, Denis ULg

in Space Science Reviews (2014)

The morphologies of the ultraviolet auroral emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although ... [more ▼]

The morphologies of the ultraviolet auroral emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although this simplified view is very handy for a gross depiction of the giant planets’ aurorae, it fails to scrutinize the diversity and the dynamics of the actual features that are regularly observed with the available ultraviolet imagers and spectrographs. In the present review, the typical morphologies of Jupiter and Saturn’s aurorae are represented with an updated and more accurate set of components. The use of sketches, rather than images, makes it possible to compile all these components in a single view and to put aside ultraviolet imaging technical issues that are blurring the emission sources, thus preventing one from disentangling the different auroral signatures. The ionospheric and magnetospheric processes to which these auroral features allude can then be more easily accounted. In addition, the use of components of the same kind for both planets may help to put forward similarities and differences between Jupiter and Saturn. The case of the ice giants Uranus and Neptune is much less compelling since their weak auroral emissions are very poorly documented and one can only speculate about their origin. This review presents a current perspective that will inevitably evolve in the future, especially with upcoming observing campaigns and forthcoming missions like Juno. [less ▲]

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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 ▲]

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See detailNumerical Simulation of Double Cup Extrusion Test Using the Arbitrary Lagrangian Eulerian Formalism
Boman, Romain ULg; Koeune, Roxane; Ponthot, Jean-Philippe ULg

in Idelsohn, Sergio R. (Ed.) Numerical Simulations of Coupled Problems in Engineering (2014)

In this chapter Double Cup Extrusion Test (DCET) is modelled using the finite element method with the help of the Arbitrary Lagrangian Eulerian (ALE) formalism. DCET is a tribological test involving very ... [more ▼]

In this chapter Double Cup Extrusion Test (DCET) is modelled using the finite element method with the help of the Arbitrary Lagrangian Eulerian (ALE) formalism. DCET is a tribological test involving very large deformations which are traditionally dealt with complicated and costly remeshing algorithms. Since the topology of ALE meshes should remain constant throughout the simulation, twovery thin layers of auxiliary elements are added to the initial mesh of the billet where the material is expected to flow. This numerical trick is combined with an original and efficient node relocation procedure which allows the model to take into account complex geometries of punches. The presented model is firstly validated for limited punch strokes thanks to a purely Lagrangian simulation. It is then compared with results from the literature. Eventually the general nature and the effectiveness of this numerical strategy is demonstrated by a fully-coupled thermomechanical simulation of thixoforming where the final shape of the billet is compared to experimental measurements. [less ▲]

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See detailSelf-medication in persistent rhinitis: overuse of decongestants in half of the patients.
Mehuys, Els; Gevaert, Philippe; Brusselle, Guy et al

in Journal of Allergy and Clinical Immunology - In Practice (2014), 2(3), 313-319

BACKGROUND: Patients with rhinitis often self-medicate with over-the-counter drugs, however this self-treating population has remained largely unstudied. OBJECTIVE: To characterize individuals self ... [more ▼]

BACKGROUND: Patients with rhinitis often self-medicate with over-the-counter drugs, however this self-treating population has remained largely unstudied. OBJECTIVE: To characterize individuals self-medicating persistent rhinitis and to determine the prevalence of and risk factors for intranasal decongestant overuse within this population. METHODS: A cross-sectional observational study of individuals self-medicating persistent rhinitis (defined according to the Allergic Rhinitis and its Impact on Asthma guidelines). Participants (n = 895) completed a self-administered questionnaire to assess current symptoms, rhinitis medication, and previous physician diagnosis. Intranasal decongestant overuse was defined as daily use for at least 1 year. RESULTS: The vast majority of subjects (95%) had moderate-to-severe rhinitis. Nasal congestion was the predominant symptom (median visual analog scale, 6.6 cm; interquartile range, 3.4 cm). Sixty-five percent had had their current nasal problems for more than 5 years. Approximately 80% had a physician diagnosis (mainly allergic rhinitis or rhinosinusitis). The prevalence of intranasal decongestant overuse was high (49%), despite the fact that most of the patients (80%) were educated about the limit on duration of use. Use of intranasal glucocorticosteroids was inversely related to being an overuser (odds ratio 0.24 [95% CI, 0.17-0.35]). The risk of intranasal decongestant overuse also was reduced by use of other medications (oral H1 antihistamines and decongestants), use of nasal saline solution, and more symptoms of itchy and/or runny eyes or colored mucus. Risk was increased by a more severely blocked nose, longer duration of symptoms, the presence of sleep disturbance, higher body mass index, and previous advice to limit the duration of intranasal decongestant use. CONCLUSION: Half of the individuals self-medicating persistent rhinitis overused intranasal decongestants, despite the fact that they were educated about the limit on duration of use. [less ▲]

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See detailLes coopératives d'énergie renouvelable favorisent les économies d'énergie
Bauwens, Thomas ULg

Article for general public (2014)

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See detailCoupling building energy simulation and computational fluid dynamics: Application to a two-storey house in a temperate climate
Barbason, Mathieu ULg; Reiter, Sigrid ULg

in Building & Environment (2014), 75

This article reports the coupling of a building energy simulation (BES) made with TRNSYS with a computational fluid dynamics (CFD) simulation made with ANSYS FLUENT and its application to a typical ... [more ▼]

This article reports the coupling of a building energy simulation (BES) made with TRNSYS with a computational fluid dynamics (CFD) simulation made with ANSYS FLUENT and its application to a typical Belgian two-storey house. The coupling scheme developed in this study aims to improve the overheating prediction for buildings. This phenomenon is becoming increasingly frequent in Northern Europe due to increased insulation and a lack of sun protection and natural cooling strategies. Complementary contributions of the two numerical approaches are underlined and used to obtain accurate results in an acceptable computing time, even in a thermally stratified room. The space and time coupling is discussed to obtain an optimised tool in which BES is in charge of the primary portion of the effort, while CFD intervenes punctually on one room of interest. The numerical results are compared both qualitatively and quantitatively to the experimental results, and the improved accuracy of the coupled tool compared with a standalone BES is underlined. [less ▲]

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See detailFactors associated with clinical inertia: an integrative review
Aujoulat, I; Jacquemin, p; Rietzschel, E et al

in Advances in Medical Education and Practice (2014), 5

Failure to initiate or intensify therapy according to evidence-based guidelines is increasingly being acknowledged as a phenomenon that contributes to inadequate management of chronic conditions, and is ... [more ▼]

Failure to initiate or intensify therapy according to evidence-based guidelines is increasingly being acknowledged as a phenomenon that contributes to inadequate management of chronic conditions, and is referred to as clinical inertia. However, the number and complexity of factors associated with the clinical reasoning that underlies the decision-making processes in medicine calls for a critical examination of the consistency of the concept. Indeed, in the absence of information on and justification of treatment decisions that were made, clinical inertia may be only apparent, and actually reflect good clinical practice. This integrative review seeks to address the factors generally associated with clinical inaction, in order to better delineate the concept of true clinical inertia. [less ▲]

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See detailEt si la promotion de la santé était un art du paradoxe !
Vandoorne, Chantal ULg

in Education Santé (2014), (300), 6-7

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See detailDioxins and PCBs in eel and Chinese mitten crabs in the Rhine-Meuse estuary
van Hattum, B; Nijssen, P; Focant, Jean-François ULg et al

Poster (2014, May)

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See detailSlavery in Greco-Roman Egypt. Slaves and slavery in the Roman period
Straus, Jean ULg

in Keenan, James G.; Manning, Joseph G.; Yiftach-Firanko, Uri (Eds.) Law and Legal Practice in Egypt from Alexander to the Arab Conquest. A Selection of Papyrological Sources in Translation with Introductions and Commentary (2014)

Translation and commentary of papyri relating to slavery in Roman Egypt

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See detailLe Musée de la Vie wallonne, indissociablement lié aux dialectologues liégeois
Frankinet, Baptiste ULg

in Culture, le Magazine Culturel de l'Université de Liège (2014)

Au-delà d’un travail pointu de description et d’explication, les dialectologues liégeois ont toujours veillé à préserver les traces d’un patrimoine immatériel menacé de disparition. Selon eux, ce ... [more ▼]

Au-delà d’un travail pointu de description et d’explication, les dialectologues liégeois ont toujours veillé à préserver les traces d’un patrimoine immatériel menacé de disparition. Selon eux, ce patrimoine dépassait le cadre strictement linguistique ou lexical pour épouser les formes d’un ensemble bien plus vaste : la vie wallonne tout entière. Impossible pour eux d’étudier un dialecte sans veiller à garder les usages ou les objets qu’il nomme, ni le souvenir des gens qui le parlent. Ainsi, en plus d’être des observateurs attentifs à leurs propres parlers, ils devinrent les premiers conservateurs de leur région. [less ▲]

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See detailCorrelation between composition and cold stability of palm liquid fractions.
Danthine, Sabine ULg; Lefebure, Emilie ULg; Dijkmans, Peggy et al

Poster (2014, May)

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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 ▲]

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See detailULTIMATE STRENGTH - Discussion on Committee ISSC2012's report
Rigo, Philippe ULg

in Fricke, Wolfgang; Bronsart, Robert (Eds.) PROCEEDINGS OF THE 18TH INTERNATIONAL SHIP AND OFFSHORE STRUCTURES CONGRESS - VOLUME 3 (2014)

Concern for the ductile behavior of ships and o shore structures and their structural components under ultimate conditions. Attention shall be given to the influence of fabrication imperfections and in ... [more ▼]

Concern for the ductile behavior of ships and o shore structures and their structural components under ultimate conditions. Attention shall be given to the influence of fabrication imperfections and in-service damage and degradation on reserve strength. Uncertainties in strength models for design shall be highlighted. [less ▲]

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See detailLes determinants des Price-Earnings ratios en Europe
Lambert, Marie ULg; Lenglois, Julien ULg; Streel, Alexandre ULg et al

E-print/Working paper (2014)

Méthode largement employée en matière d’évaluation d’entreprise, l’analyse dite comparative s’appuie sur une estimation de la valeur des entreprises selon un multiple de leur agrégat financier. Aussi ... [more ▼]

Méthode largement employée en matière d’évaluation d’entreprise, l’analyse dite comparative s’appuie sur une estimation de la valeur des entreprises selon un multiple de leur agrégat financier. Aussi appelée ‘méthode des pairs’, les multiples sont définis sur base d’un échantillon d’entreprises considérées comme comparable en termes de croissance et de risque. Le secteur est généralement retenu en pratique comme critère sous-tendant la croissance et le profil de risque opérationnel de l’entreprise. L’analyse menée dans cet article démontre l’importance des fondamentaux tels que la croissance, le risque et le taux de distribution des bénéfices dans la définition des pairs et donc de la valeur des entreprises. Sur base d’un échantillon des 100 entreprises cotées sur l’EURONEXT, entreprises les plus capitalisées et liquides, l’étude met en évidence un impact différencié de ces déterminants selon les conditions économiques. Les conséquences de notre analyse sont multiples. Premièrement, notre étude témoigne de l’importance des variables telles que le profil de risque et les perspectives croissance pour la sélection des pairs. Notre approche permet par ailleurs d’appréhender la valeur des entreprises sur base de leurs propres fondamentaux, corrigeant ainsi la méthode des multiples ‘sectoriels’ pour les différences qui subsistent au sein des sous-jacents de la valeur. Finalement, cet article nourrit une discussion quant à l’impact de la finance comportementale sur la valorisation de l’entreprise de par l’impact différencié des fondamentaux sur la valeur des entreprises au cours du temps. [less ▲]

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See detailTransit confirmation and improved stellar and planet parameters for the super-Earth HD 97658 b and its host star
Van Grootel, Valérie ULg; Gillon, Michaël ULg; Valencia, D. et al

in Astrophysical Journal (2014), 786

Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition ... [more ▼]

Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present here the confirmation, based on Spitzer transit observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a low-mass ($M_*=0.77\pm0.05\,M_{\odot}$) K1 dwarf, as determined from the Hipparcos parallax and stellar evolution modeling. To constrain the planet parameters, we carry out Bayesian global analyses of Keck-HIRES radial velocities, and MOST and Spitzer photometry. HD 97658 b is a massive ($M_P=7.55^{+0.83}_{-0.79} M_{\oplus}$) and large ($R_{P} = 2.247^{+0.098}_{-0.095} R_{\oplus}$ at 4.5 $\mu$m) super-Earth. We investigate the possible internal compositions for HD 97658 b. Our results indicate a large rocky component, by at least 60% by mass, and very little H-He components, at most 2% by mass. We also discuss how future asteroseismic observations can improve the knowledge of the HD 97658 system, in particular by constraining its age. Orbiting a bright host star, HD 97658 b will be a key target for coming space missions TESS, CHEOPS, PLATO, and also JWST, to characterize thoroughly its structure and atmosphere. [less ▲]

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See detailWhat you should know before starting minimal invasive liver resection: an overview
DETRY, Olivier ULg

in Acta Chirurgica Belgica (2014, May), 114(3), 117

Laparoscopic liver surgery has evolved over the last 2 decades. Advancements in surgical technology, surgical technique, and postoperative care have aided in lifting barriers to laparoscopic liver ... [more ▼]

Laparoscopic liver surgery has evolved over the last 2 decades. Advancements in surgical technology, surgical technique, and postoperative care have aided in lifting barriers to laparoscopic liver resections (LLR). LLR might decrease morbidity and hospitalisation stay compared to open approach, and importantly in liver surgery, may decrease postoperative costal pain. However, in hepatic surgery as in all abdominal procedures, laparoscopic approach is a mean but not a goal. The possibility of LLR should neither modify indications for surgery nor the type of resection. Physiologic modifications induced by CO2 pneumoperitoneum should be known by the surgical and anaesthetic team involved in LLR. Pneumoperitoneum decreases cardiac output, and this decrease could be worsened by the reverse Trendelenburg position and by hepatic hilar clamping. CO2 pneumoperitoneum decreases hepatic blood flow. This is a clear advantage for limiting blood loss during LLR, but this also might increase liver ischemia during Pringle liver hilum clamping, a manoeuvre that should be avoided in LLR. Low venous pressure might decrease blood loss by the small supra hepatic veins, but may also further decrease cardiac output. Several devices may be used for liver section, without evidence of the superiority of one device compared to others. Endo GIA might be very helpful to control the major liver vessels, as branches of portal vein or suprahepatic veins. Significant CO2 embolism is a rare complication, and conversion to open approach for haemorrhage should be performed only if blood loss is controlled. Up to now, there is no clear scientific evidence that laparoscopic approach provides any advantage compared to open approach. SILS, LESS or even robotic approaches should only considered as purely experimental. Current barriers to LLR will continue to fall in the future. [less ▲]

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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 ▲]

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