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See detailA new test of uniformity for object orientations in astronomy
Pelgrims, Vincent ULg

in Heavens, A. F.; Starck, J.-L.; Krone-Martins, A. (Eds.) Statistical Challenges in 21st Century Cosmology (2015, July 01)

We briefly present a new coordinate-invariant statistical test dedicated to the study of the orientations of transverse quantities of non-uniformly distributed sources on the celestial sphere. These ... [more ▼]

We briefly present a new coordinate-invariant statistical test dedicated to the study of the orientations of transverse quantities of non-uniformly distributed sources on the celestial sphere. These quantities can be projected spin-axes or polarization vectors of astronomical sources. [less ▲]

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See detailBiomechanical Analysis of Abdominal Injury in Tennis Serves. A Case Report
Tubez, François ULg; Forthomme, Bénédicte ULg; Croisier, Jean-Louis ULg et al

in Journal of Sports Science & Medicine (2015), 14

The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is ... [more ▼]

The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is potentially deleterious for upper limbs, lower limbs and trunk. The trunk is a vital link in the production and transfer of energy from the lower limbs to the upper limbs; therefore, kin-ematic disorder could be a potential source of risk for trunk injury in tennis. This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after tennis serve. The goal of the study is to understand whether the injury could be explained by an inappropriate technique. For this purpose, we analyzed in three dimensions the kinematic and kinetic aspects of the serve. We also performed isokinetic tests of the player’s knees. We then compared the player to five other professional players as refer-ence. We observed a possible deficit of energy transfer because of an important anterior pelvis tilt. Some compensation made by the player during the serve could be a possible higher abdominal contraction and a larger shoulder external rotation. These partic-ularities could induce an abdominal overwork that could explain the first injury and may provoke further injuries. [less ▲]

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See detailWASP-80b has a dayside within the T-dwarf range
Triaud, Amaury H. M. J.; Gillon, Michaël ULg; Ehrenreich, David et al

in Monthly Notices of the Royal Astronomical Society (2015), 450

WASP-80b is a missing link in the study of exoatmospheres. It falls between the warm Neptunes and the hot Jupiters and is amenable for characterization, thanks to its host star's properties. We observed ... [more ▼]

WASP-80b is a missing link in the study of exoatmospheres. It falls between the warm Neptunes and the hot Jupiters and is amenable for characterization, thanks to its host star's properties. We observed the planet through transit and during occultation with Warm Spitzer. Combining our mid-infrared transits with optical time series, we find that the planet presents a transmission spectrum indistinguishable from a horizontal line. In emission, WASP-80b is the intrinsically faintest planet whose dayside flux has been detected in both the 3.6 and 4.5 μm Spitzer channels. The depths of the occultations reveal that WASP-80b is as bright and as red as a T4 dwarf, but that its temperature is cooler. If planets go through the equivalent of an L-T transition, our results would imply that this happens at cooler temperatures than for brown dwarfs. Placing WASP-80b's dayside into a colour-magnitude diagram, it falls exactly at the junction between a blackbody model and the T-dwarf sequence; we cannot discern which of those two interpretations is the more likely. WASP-80b's flux density is as low as GJ 436b at 3.6 μm; the planet's dayside is also fainter, but bluer than HD 189733Ab's nightside (in the [3.6] and [4.5]Spitzer bands). Flux measurements on other planets with similar equilibrium temperatures are required to establish whether irradiated gas giants, such as brown dwarfs, transition between two spectral classes. An eventual detection of methane absorption in transmission would also help lift that degeneracy. We obtained a second series of high-resolution spectra during transit, using HARPS. We reanalyse the Rossiter-McLaughlin effect. The data now favour an aligned orbital solution and a stellar rotation nearly three times slower than stellar line broadening implies. A contribution to stellar line broadening, maybe macroturbulence, is likely to have been underestimated for cool stars, whose rotations have therefore been systematically overestimated. [less ▲]

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See detailLa Musique silencieuse de José Muñoz et Carlos Sampayo : déconstruction des normes et lecture émotionnelle
Dejasse, Erwin ULg

Doctoral thesis (2015)

Cette thèse met en lumièredans l'oeuvre de José Muñoz et Carlos Sampayo les mécanismes de déconstruction des normes issues de la bande dessinée de genre fondée sur le principe de l’illusion référentielle ... [more ▼]

Cette thèse met en lumièredans l'oeuvre de José Muñoz et Carlos Sampayo les mécanismes de déconstruction des normes issues de la bande dessinée de genre fondée sur le principe de l’illusion référentielle. Cette entreprise de dislocation des standards graphiques et narratifs vise à substituer à la lecture traditionnelle fondée sur la consommation du récit, une lecture émotionnelle. [less ▲]

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See detailIntégration de la continuité spatiale dans la structure multidimensionnelle d’un entrepôt de données - SOLAP raster
Kasprzyk, Jean-Paul ULg

Doctoral thesis (2015)

Technological advances in recent decades have created a massive acquisition of digital data whose volume grows exponentially. To efficiently extract the information they contain, powerful tools have been ... [more ▼]

Technological advances in recent decades have created a massive acquisition of digital data whose volume grows exponentially. To efficiently extract the information they contain, powerful tools have been developed to collect, store and analyze these data. These tools are gathered in a discipline called “business intelligence”. Among them, data warehouses are responsible for archiving data by structuring them in a multidimensional way (time, space or others). They are called data hypercubes or data cubes when they are limited to three dimensions. Hypercubes can supply OLAP (On Line Analytical Processing) systems that aim at quickly synthesizing information in interactive tables and charts for decision-makers from various fields: marketing, environment, criminology, etc. Thus, users can navigate into hypercubes using OLAP operations such as slicing on dimension members (e.g. data aggregation for the month of January in the time dimension), or drilling into hierarchies (e.g. switching from the “year” level to the “month” level in the time dimension). When OLAP is coupled with spatial analysis techniques supplied by geographic information systems (GIS), a map interface then improves the exploration of data: OLAP operations can be applied to dimensions defined in the geographical space (spatial drilling or spatial slicing). This kind of tool is called SOLAP (Spatial OLAP). SOLAP tools currently available on the market all suffer from the same deficiency: they are unable to represent spatial dimensions (X, Y) in a continuous way. This representation is nevertheless essential for the management of spatially continuous phenomena (temperature, pollution, etc.) but also for visualizing spatially discrete events (product sales, crimes, etc.) while minimizing the Modifiable Areal Unit Problem (MAUP). This kind of visualization is used especially by the police to predict the location of future crimes through hotspot maps which are generated by the Kernel Density Estimation (KDE) method. In the field of GIS, raster data (as opposed to vector data) enable effective representation of spatial continuity through digital georeferenced grids. Whereas current SOLAP tools only consider vector data, our research uses the raster model to integrate spatial continuity into the multidimensional structure of a data warehouse feeding a SOLAP ("raster SOLAP"). Despite its underutilization in the SOLAP literature, the raster model has many similarities with a particular kind of data cube: the MOLAP cube (Multidimensional OLAP). Like a satellite image (raster) representing the two planimetric spatial dimensions and one "spectral band" dimension, a MOLAP cube is a three dimensional array whose cells’ coordinates (similar to raster pixels) enable an efficient indexation of dimensions’ members (describing the analyzed facts). In a first original model that we call "raster cube" we define the bases for a three-dimensional raster SOLAP, starting from the definition of a MOLAP cube. Unlike vector SOLAP - where spatiality is attached to a semantic dimension through pointers to geometries - our model directly integrates spatial dimensions (X, Y) in the multidimensional structure of the data warehouse. With this original feature, any geographical entity (country, building, road, etc.) can be imported on the fly as a member in the analysis of the user, which is hardly possible with conventional vector SOLAP tools. An extension of this SOLAP model, called "raster hypercube", is then developed by entrusting the management of extra non-spatial dimensions to a relational database management system (Relational OLAP or ROLAP). The raster hypercube is then populated by KDE raster fields representing crime densities, which are defined in a continuous space (raster dimensions) through time and crime types (ROLAP dimensions). Our model is able to combine the production of hotspot maps at different scales of analysis with SOLAP navigation operations: slicing on spatial or non-spatial members, and drilling into the hierarchy of spatial or non-spatial dimensions. Our raster hypercube model is validated by an operating prototype which is based on open source tools only. Several datasets are integrated through KDE fields, including crime data from London and Seattle. At the end of our work, the results of a comparative study between raster SOLAP and vector SOLAP demonstrate that hybrid vector/raster SOLAP architectures present the same interest for spatial data as hybrid ROLAP/MOLAP architectures do for purely semantic data (management of detailed hypercubes [less ▲]

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See detailEtude de l'évolution de l'enneigement dans les Hautes Fagnes (Belgique) au cours des cinquante dernières années à l'aide du modèle climatique régional MAR
Wyard, Coraline ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

in Erpicum, Michel (Ed.) Actes du XXVIIIe colloque annuel de l’Association Internationale de Climatologie : Modélisations et variabilités (2015, July)

The “Modèle Atmosphérique Régionale” MAR is a regional climate model originally developed to study the polar ice sheets. In this study, the MAR model has been adapted to Belgium in order to study the snow ... [more ▼]

The “Modèle Atmosphérique Régionale” MAR is a regional climate model originally developed to study the polar ice sheets. In this study, the MAR model has been adapted to Belgium in order to study the snow cover evolution of the High Fens (east of Belgium), a region covered by snow on average one to two months per year. As validation, we have sucessfully compared MAR based daily snow heights with snowcam-based and/or laser sensor-based observations over the period 2008-2013. Then, the model has been forced by ERA-Interim since 1958 to study the snow cover evolution during the last fifty years at the summit of Belgium. The results show no significant trend despite global warming. [less ▲]

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See detailGlucosinolates and by-products in rapeseed meal related to hydrothermal processing
Quinsac, A.; Carré, P.; Fauconnier, Marie-Laure ULg et al

Poster (2015, July)

Background: For safety reasons, rapeseed meal (RSM) is usually desolventized with strong hydrothermal treatments, leading to various levels of residual glucosinolates (GSL), and protein solubility. The ... [more ▼]

Background: For safety reasons, rapeseed meal (RSM) is usually desolventized with strong hydrothermal treatments, leading to various levels of residual glucosinolates (GSL), and protein solubility. The RSM nutritional quality may be then lowered for monogastrics, due to GSL breakdown products whose reliable and “easy to use” indicators lack. [less ▲]

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See detailPromoting Competition at the Digital Age with an Application to Belgium
Copée, Pierre ULg; Gautier, Axel ULg; Lefevre, Mélanie ULg

E-print/Working paper (2015)

In this paper, we develop a fully-fledged postal market model to assess the extent of competition in the mail market in a context of declining mail volumes due to e-substitution. Our focus will be on the ... [more ▼]

In this paper, we develop a fully-fledged postal market model to assess the extent of competition in the mail market in a context of declining mail volumes due to e-substitution. Our focus will be on the Belgian market situation that is interesting for at least two reasons. First, the homogenous nature of the country implies that the extent of the entrant's market coverage will be either limited to the few very densely populated areas or large covering the whole country at the exception of the few very sparely populated areas. Second, because strong licensing requirements -including coverage constraints- are imposed on competing postal operators and they may constitute barrier to entry. Our model allows us to estimate the extent of entry, the cost of meeting the licensing requirements for potential entrants and the impact of entry on the cost of the universal service. [less ▲]

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See detailDe nationaliteit van Belgische ‘jihadisten’ op de schopstoel : wanneer worden ‘nieuwe’ Belgen ‘echte’ Belgen?
Wautelet, Patrick ULg

Conference (2015, July)

This presentation first gives an overview of the current legal standards for deprivation of nationality based on terrorism in Belgium and France. In a second part, it focuses on the question whether it ... [more ▼]

This presentation first gives an overview of the current legal standards for deprivation of nationality based on terrorism in Belgium and France. In a second part, it focuses on the question whether it may be justified to treat different categories of nationals differently in nationality law and more specifically when dealing with deprivation of nationality. An attempt is made to analyze the French and Belgian legal framework from the angle of the prohibition of discrimination. [less ▲]

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See detailHybrid inventory, gravimetry and altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic
Colgan, W.; Abdalati, W.; Citterio, M. et al

in Remote Sensing of Environment (2015), 168

We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere ... [more ▼]

We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere-attributed mass trends derived from satellite gravimetry, and ice surface elevation trends derived from airborne and satellite altimetry. We use this algorithm to assess mass balance across Greenland and the Canadian Arctic over the Sep-2003 to Oct- 2009 period at 26 km resolution. We evaluate local algorithm-inferred mass balance against forty in situ point observations. This evaluation yields an RMSE of 0.15 mWE/a, and highlights a paucity of in situ observations from regions of high dynamic mass loss and peripheral glaciers. We assess mass losses of 212 ± 67 Gt/a to the Greenland ice sheet proper, 38 ± 11 Gt/a to peripheral glaciers in Greenland, and 42 ± 11 Gt/a to glaciers in the Canadian Arctic. These magnitudes of mass loss are dependent on the gravimetry-derived spherical harmonic mass trend we invert. We spatially partition the transient glacier continuity equation by differencing algorithm-inferred mass balance from modeled surface mass balance, in order to solve the horizontal divergence of ice flux as a residual. This residual ice dynamic field infers flux divergence (or submergent flow) in the ice sheet accumu- lation area and at tidewater margins, and flux convergence (or emergent flow) in land-terminating ablation areas, which is consistent with continuum mechanics theory. [less ▲]

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See detailTowards precision β-decay measurements with laser cooled 35Ar
Glover, Rohan ULg; Lenaers, Florence ULg; Velten, Philippe et al

Poster (2015, July)

Detailed reference viewed: 15 (2 ULg)
See detailQuadratization of pseudo-Boolean functions
Crama, Yves ULg; Anthony, Martin; Boros, Endre et al

Conference (2015, July)

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See detailComparaison de l’effet du guidage échographique sur les ponctions de liquide céphalo-rachidien entre les localisations cisternales et lombaires chez le chien : une étude ex vivo
Etienne, Anne-Laure ULg; Peeters, Dominique ULg; Busoni, Valeria ULg

in Annales de Médecine Vétérinaire (2015), 158

RÉSUMÉ : Le placement échoguidé de l’aiguille spinale pour les ponctions cisternale et lombaire chez le chien a été décrit. L’objectif de ce travail était de comparer l’effet du guidage échographique pour ... [more ▼]

RÉSUMÉ : Le placement échoguidé de l’aiguille spinale pour les ponctions cisternale et lombaire chez le chien a été décrit. L’objectif de ce travail était de comparer l’effet du guidage échographique pour la ponction de liquide céphalo-rachidien entre les ponctions cisternale et lombaire. Quatre-vingt-trois opérateurs ont participé à l’étude. Ils étaient divisés en quatre groupes selon leur expérience. Après une formation théorique courte, chaque opérateur a réalisé une ponction cisternale et lombaire en aveugle et sous contrôle échographique sur des cadavres tirés au sort. L’échoguidage lombaire était direct alors que celui cisternal était indirect. Après chaque procédure, les opérateurs ont rempli un questionnaire sur leur expérience, leur performance et leur confiance en soi. L’échoguidage augmentait significativement le taux de réussite global de la ponction (comparée à la méthode en aveugle) mais plus clairement avec la localisation lombaire. Le guidage échographique cisternal améliorait significativement le nombre de tentatives, le temps et la confiance en soi chez les opérateurs inexpérimentés et expérimentés. La première cause d’échec citée était différente selon la localisation de la ponction et était liée à la nature de l’échoguidage. Cette étude démontre que les opérateurs inexpérimentés sont capables de réaliser des ponctions échoguidées après une formation théorique courte, justifiant l’utilité du guidage échographique à des fins pédagogiques. [less ▲]

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See detailCarbides and grain size quantification methods in high speed steel alloys
Tchuindjang, Jérôme Tchoufack ULg; Paydas, Hakan ULg; Hashemi, Seyedeh Neda ULg et al

Conference (2015, July)

High speed steel (HSS) grades are widely used as in highly stressed applications where carbides content promote enhanced mechanical properties together with oxidation and wear resistances. Such a ... [more ▼]

High speed steel (HSS) grades are widely used as in highly stressed applications where carbides content promote enhanced mechanical properties together with oxidation and wear resistances. Such a tribological behaviour is mainly due to the presence of primary carbides. It is thus important to quantify the carbide volume fraction in HSS to correlate this result with the mechanical and tribological properties of the materials. Depending of the steel composition several types of carbides are precipitated in HSS: MC (Nb and V-rich), M2C (Mo and W-rich), Cr-rich M7C3 and some others, depending of the chemical composition. Two groups of HSS were analyzed in this study: cast HSS manufactured by centrifugal casting and cladded HSS manufactured by laser cladding. Depending on the chemical composition and the manufacturing process of the studied material, several methods have been used to quantify the carbide volume fraction and the grain size. [less ▲]

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See detailDevelopment of quantification methods applied to HSS alloys for carbides volume fraction and grain size assessments
Tchuindjang, Jérôme Tchoufack ULg; Paydas, Hakan ULg; Hashemi, Seyedeh Neda ULg et al

Poster (2015, July)

High speed steels (HSS) are used in applications where enhanced mechanical properties together with hot oxidation and wear resistances are required. Such an improved physico-chemical behaviour is mainly ... [more ▼]

High speed steels (HSS) are used in applications where enhanced mechanical properties together with hot oxidation and wear resistances are required. Such an improved physico-chemical behaviour is mainly due to the presence of primary carbides within the microstructure. Depending of the initial chemical composition several types of carbides can precipitate in HSS such as MC (Nb and V-rich), M2C (Mo and W-rich), Cr-rich M7C3, etc. Two groups of HSS were analysed in this study, which are the so-called cast HSS grades that are manufactured by a centrifugal casting process and the cladded HSS manufactured by laser cladding. Purpose: Quantify the carbide volume fractions and the grain size within HSS grades in order to set correlations between the microstructure and both the mechanical and the tribological properties of the materials. Findings: The metallurgical features such as carbides nature and shape have been determined that are related to the manufacturing process of the studied material, and several methods have been used to quantify the carbide volume fractions and to assess the grain size. [less ▲]

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See detailA ROBUST APPROACH OF TOPOLOGIC OPTIMIZATION OF MECHANICAL AND AERONAUTICAL COMPONENTS FABRICATED BY ADDITIVE MANUFACTURING
Bauduin, Simon ULg

in Bauduin, Simon (Ed.) Poster : A ROBUST APPROACH OF TOPOLOGIC OPTIMIZATION OF MECHANICAL AND AERONAUTICAL COMPONENTS FABRICATED BY ADDITIVE MANUFACTURING (2015)

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See detailMarcel-Henri Jaspar, "Le plus gaullien des Belges" ? Construction et déconstruction d'une réputation (1940-1966)
Genin, Vincent ULg

in Lanneau, Catherine; Depagie, Francis (Eds.) De Gaulle et la Belgique (2015, July)

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