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See detailNew computational method of the ball/race contacts transverse loads of high speed ball bearings without race control hypothesis
Servais, Christophe ULg; Bozet, Jean-Luc ULg

in Tribology International (2017), 113

Some hypotheses are still necessary in order to access the ball bearing Newtonian equilibrium with quasi-static methods. Among these hypotheses are the values of the transverse loads within ball/race ... [more ▼]

Some hypotheses are still necessary in order to access the ball bearing Newtonian equilibrium with quasi-static methods. Among these hypotheses are the values of the transverse loads within ball/race contacts. Those loads are due to the gyroscopic torques. Nowadays, the transverse loads are estimated without any equilibrium criterion by the specialized literature. Moreover, the race control assumption is often employed in addition to the hypotheses made about the transverse loads. The paper describes a new method to compute the transverse loads without using the race control assumption. Then, a correlation between the ball bearing kinematics and the transverse loads is established. It leads to an accurate and efficient computational method to access the Newtonian equilibrium of high speed ball bearings. [less ▲]

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See detailAnalysis of definitions of General Practice/Family Medicine and Primary Health Care
Jamoulle, Marc ULg; Resnick, Melissa; Ittoo, Ashwin ULg et al

in British Journal of General Practice (2017)

Abstract Background There are numerous definitions of General Practice and Family Medicine (GP/FM) and Primary Health Care (PHC), but the distinction between the two concepts is unclear. Aim To conduct a ... [more ▼]

Abstract Background There are numerous definitions of General Practice and Family Medicine (GP/FM) and Primary Health Care (PHC), but the distinction between the two concepts is unclear. Aim To conduct a terminological analysis of a set of definitions of GP/FM and of PHC, to clarify what binds and what distinguishes these two concepts. Design The terms of 20 definitions were collected in two bags of words (one for GP/FM and one for PHC terms). A terminological analysis of these two bags of words was performed to prioritize the terms and analyze their world of reference. Methods The two collected bags of words were extracted with Vocabgrabber®, configured in two term butts using Wordle®, and further explored for similarities using Tropes®. The prioritized terms were analyzed using the Aristotelian approach to categorization of things. Results Although continuity of care (with person-centered approach and shared decision making) is the central issue of the two sets, the two sets of definitions differ greatly in content. The prioritized terms specific to GP/FM (community, medicine, responsibility, individual, problem, needs, ...) are different from prioritized terms specific to PHC (home, team, promotion, collaborator, engagement, neighborhood, medical center…). Conclusion Terminological analysis of the definitions for GP/FM and PHC shows two entities which are overlapping but distinct, necessitating a different taxonomic approach and different bibliographic search strategies. [less ▲]

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See detailLandscape and hydrological controls on the downstream transport of dissolved organic matter in the Congo and Zambezi rivers
Lambert, T; Bouillon, S; Teodoru, CR et al

Conference (2017, August 20)

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See detailConstruction of high-resolution trace element time-series in Belgian speleothems by LA-ICP-MS
Allan, Mohammed ULg; verheyden, sophie; crucifix, michel et al

Conference (2017, August 17)

Speleothems, presented in Belgium, are now regarded as valuable archive of paelenvirenmental variations on the continents, offering a number of advantages relative to other continental climate proxy ... [more ▼]

Speleothems, presented in Belgium, are now regarded as valuable archive of paelenvirenmental variations on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments. They are reliable continental archives of high interest due to their dating possibilities and their possibility to preserve multi-proxy records of environmental and climatic dynamics. Establishing high-resolution trace element time series in speleothems requires analytical techniques capable of representative sampling at sub-annual spatial resolution (on order of 22 µm in this study). In the Belgian Pere Noel cave (PN), high spatial resolution measurements of trace elements (e.g., Mg, Sr, Ba) were realized by using LA-ICP-MS and compared with results from lower resolution techniques (ICP-MS). The results from both techniques have been analysed in order to assess the capability of each technique to reconstruct climate changes at high resolution from PN stalagmite. Results showed that LA-ICP-MS technique allows a rapid analysis of multiple elemental concentrations, and uses minimal sample volume allowing for replicate sampling and availability of almost the entire original sample for other analyses. [less ▲]

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See detail3D thermal finite element analysis of laser cladding processed Ti-6Al-4V part with microstructural correlations
Tran, Hoang Son ULg; Tchuindjang, Jérôme Tchoufack ULg; Paydas, Hakan ULg et al

in Materials & Design (2017), 128

In this study, a 3D thermal model of laser cladding by powder injection applied to Ti-6Al-4V is developed. The manufactured part is made of a Ti-6Al-4V substrate on which successive layers of laser melted ... [more ▼]

In this study, a 3D thermal model of laser cladding by powder injection applied to Ti-6Al-4V is developed. The manufactured part is made of a Ti-6Al-4V substrate on which successive layers of laser melted powder are added, leading to a thick deposit. The computed temperature field and its time evolution are compared to experimental measurements. The temperature distribution in the substrate allows the prediction of the depths of the melt pool and the heat affected zone. Correlations between simulated thermal histories and the final microstructure in the thick deposit are established, leading to the enhancement of a dynamic shift of the critical transformation points due to high thermal rates during laser processing. The nature of the phases present within the deposit is discussed. [less ▲]

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See detailSimilarity of the Jovian satellite footprints: spots multiplicity and dynamics
Bonfond, Bertrand ULg; Grodent, Denis ULg; Badman, S. V. et al

in Icarus (2017), 292(2017), 208217

In the magnetospheres of Jupiter and Saturn, the intense interaction of the satellites Io, Europa, Ganymede and Enceladus with their surrounding plasma environment leaves a signature in the aurora of the ... [more ▼]

In the magnetospheres of Jupiter and Saturn, the intense interaction of the satellites Io, Europa, Ganymede and Enceladus with their surrounding plasma environment leaves a signature in the aurora of the planet. Called satellite footprints, these auroral features appear either as a single spot (Europa and Enceladus) or as multiple spots (Io and Ganymede). Moreover, they can be followed by extended trailing tails in the case of Io and Europa, while no tail has been reported for Ganymede and Enceladus, yet. Here we show that all Jovian footprints can be made of several spots. Furthermore, the footprints all experience brightness variations on timescale of 2-3 minutes. We also demonstrate that the satellite location relative to the plasma sheet is not the only driver for the footprint brightness, but that the plasma environment and the magnetic field strength also play a role. These new findings demonstrate that the Europa and Ganymede footprints are very similar to the Io footprint. As a consequence, the processes expected to take place at Io, such as the bi-directional electron acceleration by Alfvén waves or the partial reflection of these waves on plasma density gradients, can most likely be extended to the other footprints, suggesting that they are indeed universal processes. [less ▲]

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See detailInfluence of urban patterns on flooding
Bruwier, Martin ULg; Mustafa, Ahmed; Aliaga, Daniel et al

in E-proceedings of the 37th IAHR World Congress (2017, August)

The goal of this paper is to identify the respective influence of different characteristics of urban patterns on urban flooding. A set of 2,290 alternate urban patterns was generated randomly using an ... [more ▼]

The goal of this paper is to identify the respective influence of different characteristics of urban patterns on urban flooding. A set of 2,290 alternate urban patterns was generated randomly using an urban generator tool providing the geometry of buildings and their relative location to the ground, over a square area of 1 km². Steady 2-D hydraulic computations were performed for these 2,290 different urban patterns with identical hydraulic boundary conditions. The computational time was reduced by using an anisotropic porosity model. This model uses relatively coarse computational cells; but preserves information from the detailed topographic data through the use of porosity parameters. Based on the computed maps of waterdepths for the 2,290 urban patterns, a sensitivity analysis based on a multiple linear regression was performed to outline the most influential urban characteristics. [less ▲]

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See detailVoice use among music theory teachers
Schiller, Isabel ULg; Morsomme, Dominique ULg; Sfez, Lou et al

Conference (2017, August)

In Belgium, there is a particular group of music teachers referred to as music theory teachers. Working at music schools, they convey theoretical knowledge and practical musical skills to groups of ... [more ▼]

In Belgium, there is a particular group of music teachers referred to as music theory teachers. Working at music schools, they convey theoretical knowledge and practical musical skills to groups of individuals who learn music during their free-time. Even though music theory teachers use both speaking and singing voice intensively at work, little is known about their voice use profiles. This study investigated the vocal loading among French-speaking music theory teachers. Objectives were (1) to describe their professional and extra-professional vocal loading, (2) to determine the relationship between vocal loading and background noise level and (3) to investigate whether objectively measured vocal loading is reflected in music theory teachers’ auto-evaluation of their voice. Using voice dosimetry, 13 music theory teachers were monitored for one workweek. Parameters analysed were F0, voice sound pressure level (SPL), phonation time, vocal loading index (VLI) and background noise SPL. At the end of each monitoring day, subjects self-assessed their voice use by means of visual analogue scales. Results revealed (1) significantly higher vocal loading in the professional context than in the extra-professional context, (2) significant positive correlations between background noise level and the parameters F0, voice SPL and phonation time and (3) significant correlations between the VLI and auto-evaluation data (e.g. voice quality and vocal fatigue). These results highlight that teaching music theory is a profession with high vocal demands. At work, music theory teachers are exposed to high background noise, which seems to influence their voice use and may potentially contribute to the development of voice problems among this population. Visual analogue scales provide a promising tool to subjectively investigate vocal loading among music theory teachers. [less ▲]

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See detailPrevalence of voice disorders among teachers at the beginning of their career
Schiller, Isabel ULg

Poster (2017, August)

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even ... [more ▼]

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even student teachers, whose vocal load is still relatively low, report voice problems with a frequency of 20 % (Simberg, Laine, Sala, & Rönnemaa, 2000). Little is known about the prevalence of voice disorders among teachers at the very beginning of their career. In Germany, teachers must complete a two-year teaching practice as part of their professional training after they graduate from university, consisting of attending specialized courses and giving lessons. The aim of this symptom-based study was to determine the prevalence of voice problems among this population. A self-administered questionnaire was answered by 73 German teachers in teaching practice. The prevalence of a voice problem was defined based on the presence of two symptoms that persisted for a minimum of two weeks. Results revealed that 37 % of teachers had voice problems during their teaching practice. Among the most frequent symptoms were hoarseness, an urge to clear one’s throat and problems speaking at a loud voice. Considering that the participants had not even begun teaching full-time, the prevalence of reported voice problems is worrisome. It could be associated with their lacking experience in how to use their voice effectively. The findings highlight the necessity of early intervention programs focusing on vocal hygiene and effective voice use in classroom situations. [less ▲]

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See detailItem purification versus adjustments for multiple comparisons in DIF detection
Drabinova, Adela; Martinkova, Patricia; Magis, David ULg

Poster (2017, July 18)

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See detailmstR: An R package to generate multistage testing designs
Magis, David ULg; Yan, Duanli; von Davier, Alina

Conference (2017, July 18)

Multistage testing (MST; Yan, von Davier & Lewis, 2014) has become an important framework of tailored testing. Similarly to computerized adaptive testing (CAT) it proposes an optimal routing of the ... [more ▼]

Multistage testing (MST; Yan, von Davier & Lewis, 2014) has become an important framework of tailored testing. Similarly to computerized adaptive testing (CAT) it proposes an optimal routing of the administered items according to the previous test taker’s responses. However, items are not selected and administered as single units but as modules (subsets). The main goal of MST consists in selecting the optimal path of modules across the successive stages of the test. Unfortunately, if various operational testing programs are nowadays considering MST for practical administrations, there is still very limited access to accurate software that can either treat or generate MST scenarios for research purposes. In this talk we succinctly present a new package from the R software, called mstR (Magis, Yan & von Davier, 2017). Built in the same spirit of the package catR for CAT designs, it permits to generate repeated response patterns under a predefined MST scenario by providing the set of modules and related item parameters, the number of stages and the connections between modules from successive stages. Several rules for optimal module selection and ability estimation (under IRT framework or based on test scores) are also available. This talk will mostly focus on the (non-technical) description of package mstR and its main features. An example will also be described as an illustration of this framework. [less ▲]

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See detailUndoing Art
Delville, Michel ULg

Conference (2017, July 13)

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See detailPrésidence de la session "Réappropriations: recyclages, effacements, détournements"
Delville, Michel ULg

Diverse speeche and writing (2017)

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See detailRhétorique du détournement vidéoludique. Le cas de Pokémon
Barnabé, Fanny ULg

Doctoral thesis (2017)

La présente recherche se situe au croisement de plusieurs traditions disciplinaires – les sciences du jeu, les études littéraires, la rhétorique, les cultural studies – et de plusieurs objets – le jeu, le ... [more ▼]

La présente recherche se situe au croisement de plusieurs traditions disciplinaires – les sciences du jeu, les études littéraires, la rhétorique, les cultural studies – et de plusieurs objets – le jeu, le détournement, les fanfictions, machinimas, speedruns, let’s plays et mods. Sans prétendre opérer ici leur synthèse ou leur conciliation, nous tenterons de dégager, entre ces différents domaines, de nouvelles ouvertures : nous montrerons, en circulant parmi eux, qu’ils sont pris dans des tensions, des dynamiques, des questionnements similaires et, surtout, centraux pour la compréhension de la culture populaire contemporaine. Plusieurs objectifs nous animent : définir le détournement et, à travers lui, éclairer sous un autre jour le fonctionnement du jeu ; développer un métadiscours à même de soutenir l’analyse des œuvres produites par les joueurs ; enfin, par la même occasion, défendre l’intérêt d’étudier de près ces œuvres amateurs, trop souvent délaissées par la recherche au profit des pratiques, et qui sont pourtant des épicentres essentiels autour desquels se développent les cultures ludiques. La poursuite de ces objectifs, toutefois, ne va pas sans soulever des questions complexes, qui traversent toute la thèse : quels parallèles et quelle frontière établir entre le détournement et le jeu ? Comment une œuvre est-elle reconnue, étiquetée, classée comme un détournement ? Qu’est-ce au juste qu’une œuvre dans un domaine où l’intertextualité, la reprise, la réinterprétation sont des normes ? Avec quels outils décrire les formes du détournement, et qu’ont en commun les genres disparates regroupés sous cette dénomination ? Nous traiterons ces diverses interrogations en deux temps. La première partie de la thèse, qui comporte deux sous-sections, en constituera le socle théorique : un premier chapitre y aborde les relations intimes entre jeu et détournement, tout en resituant notre recherche dans les différents champs qu’elle fait se croiser ; le second chapitre s’attache à la constitution d’un cadre métadiscursif inspiré de la rhétorique, visant à définir ce que pourraient être des « figures » du détournement vidéoludique. La deuxième partie, plus analytique, servira d’application au cadre précédemment construit, en montrant son utilité sur des études d’œuvres concrètes. Celles-ci sont réparties en trois grandes catégories : les détournements par le play (let’s plays, speedruns, tool-assisted speedruns et machinimas), les détournements du game (fanfictions et mods) et les recontextualisations (« Twitch plays… »). Par ailleurs, en guise de fil conducteur, toutes ces œuvres – de formes et de genres variés – auront pour point commun essentiel d’être dérivées d’un même univers fictionnel : celui de la licence Pokémon. [less ▲]

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See detailDetermining fine population structure using iterative pruning
Chaichoompu, Kridsadakorn ULg; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, July 10)

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an ... [more ▼]

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an unsupervised clustering algorithm called the iterative pruning method to capture population structure (IPCAPS). Our method supports ordinal data which can be applied directly to SNP data to identify fine-level population structure and it is built on the iterative pruning Principal Component Analysis (ipPCA) algorithm (Intarapanich et al. 2009). The IPCAPS involves an iterative process using multiple splits based on multivariate Gaussian mixture modeling of principal components and Clustering EM estimation as in Lebret et al. (2015). In each iteration, rough clusters and outliers are also identified using our own method called RubikClust. The fixation index (FST) is known to measure a distance between populations and FST = 0.001 may be said to be genetically distinct among the European populations (Tian et al. 2008, Huckins et al. 2014). To observe fine-level population structure using FST, we examined simulated scenarios of one population, 500-8,000 individuals, 5,000-10,000 independent SNPs in HWE (Balding and Nichols 1995), with 100 replicates for each scenario. The simulated SNPs were encoded as additive coding and there was no missing genotype generated. We introduced negative control by subjecting individuals to be separated into two groups using kmeans. We observed that FST values of divided groups were lower than 0.0008, which can be defined as the minimum FST to detect fine-level population structure. To evaluate the performance of our method, we tested different simulated data sets of 2-3 populations, 250 individuals per population, 10,000 independent SNPs in HWE, and FST=[0.0008,0.005], with 100 replicates for each data set. For real-life data sets, we applied the IPCAPS to Thai (Wangkumhang et al. 2013) and HapMap populations. Our method showed that a population classification accuracy was superior to the ipPCA in simulated scenarios of extremely subtle structure (FST=[0.0009,0.005]). In case of the Thai population, results to detect fine-level structure were obtained as well as in case of the HapMap populations. We are convinced that the IPCAPS has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailDimensions adaptatives des fonctionnements pervers et psychopathiques : une approche étho-phénoménologique
Englebert, Jérôme ULg

Conference (2017, July 10)

Notre objectif est de discuter des diagnostics du fonctionnement psychologique pervers et de la personnalité psychopathique. Si les versions récentes du DSM (IV et 5) ignorent ces diagnostics, la pratique ... [more ▼]

Notre objectif est de discuter des diagnostics du fonctionnement psychologique pervers et de la personnalité psychopathique. Si les versions récentes du DSM (IV et 5) ignorent ces diagnostics, la pratique clinique suggère de conserver ces deux entités présentant une finesse psychopathologique plus grande et un pouvoir discriminatif plus important que la personnalité antisociale. Nous souhaitons interroger les dimensions intrinsèquement adaptatives de ces deux entités, mais aussi relever leurs différences sur le continuum de l’adaptation. Nous chercherons, en effet, à démontrer que le principe d'adaptation est une dimension centrale et commune aux deux entités, mais qui « se joue » de façons différentes pour chacune. Le pervers est hyper-adapté à son interlocuteur tout en présentant des moments paradoxaux d'inadaptation. Le psychopathe, avec sa faculté de chosification de l'alter ego et ses compétences émotionnelles paradoxales, présente une adaptation plus solitaire. Dans une perspective inspirée des paradigmes éthologique et phénoménologique, nous tenterons de cerner les différences essentielles entre ces deux modes d’être-au-monde. [less ▲]

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See detailH0LiCOW - I. H0 Lenses in COSMOGRAIL's Wellspring: program overview
Suyu, S. H.; Bonvin, V.; Courbin, F. et al

in Monthly Notices of the Royal Astronomical Society (2017), 468

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark ... [more ▼]

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature of the Universe, as well as discovering new physics. We present H0LiCOW (H[SUB]0[/SUB] Lenses in COSMOGRAIL's Wellspring), a program that aims to measure H[SUB]0[/SUB] with <3.5 per cent uncertainty from five lens systems (B1608+656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805). We have been acquiring (1) time delays through COSMOGRAIL and Very Large Array monitoring, (2) high-resolution Hubble Space Telescope imaging for the lens mass modelling, (3) wide-field imaging and spectroscopy to characterize the lens environment and (4) moderate-resolution spectroscopy to obtain the stellar velocity dispersion of the lenses for mass modelling. In cosmological models with one-parameter extension to flat Λ cold dark matter, we expect to measure H[SUB]0[/SUB] to <3.5 per cent in most models, spatial curvature Ω[SUB]k[/SUB] to 0.004, w to 0.14 and the effective number of neutrino species to 0.2 (1σ uncertainties) when combined with current cosmic microwave background (CMB) experiments. These are, respectively, a factor of ˜15, ˜2 and ˜1.5 tighter than CMB alone. Our data set will further enable us to study the stellar initial mass function of the lens galaxies, and the co-evolution of supermassive black holes and their host galaxies. This program will provide a foundation for extracting cosmological distances from the hundreds of time-delay lenses that are expected to be discovered in current and future surveys. [less ▲]

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See detailFranz Brentano vol 1. Sources and Legacy
Boccaccini, Federico ULg; Antonelli, Mauro

Book published by Routledge (2017)

Detailed reference viewed: 53 (3 ULg)