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See detailOn the joint analysis of longitudinal responses and early discontinuation in randomized trials
Vandenhende, François; Lambert, Philippe ULg

in Journal of Biopharmaceutical Statistics (2002), 12

Our focus is on the joint analysis of longitudinal nonnormal responses and early discontinuation in (pre)-clinical trials. Separate models are fitted to the two series (response and discontinuation) to ... [more ▼]

Our focus is on the joint analysis of longitudinal nonnormal responses and early discontinuation in (pre)-clinical trials. Separate models are fitted to the two series (response and discontinuation) to account for covariate and time effects. The serial dependence and the dependence between response and drop-out are also modeled. This is done using particular dependence functions, called copulas. Copulas are used to create a joint distribution with given marginal distributions. Applications are given for the analysis of heart rate/morbidity in toxicology and pain severity/intake of rescue medications in a trial on migraine. Using copulas, the level of dependence between two variables remains invariant to changes in the marginal distribution of either variable. This proves interesting in modeling the association in a longitudinal setting when responses change over time. [less ▲]

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See detailOn the Jovian aurorae: recent observational results from the Hubble Space Telescope
Bonfond, Bertrand ULg

Scientific conference (2013, June 06)

The STIS and ACS instruments on board the Hubble Space Telescope revolutionized our understanding of the aurorae at Jupiter. The high sensibility and high spatial resolution of these UV cameras allowed us ... [more ▼]

The STIS and ACS instruments on board the Hubble Space Telescope revolutionized our understanding of the aurorae at Jupiter. The high sensibility and high spatial resolution of these UV cameras allowed us to realize that these auroral emissions are made of a multitude of sub-components, such as the satellite footprints or the Polar Auroral Filaments. Moreover, these sub-components originate from very different regions in the magnetosphere and arise from totally different processes. Here I will review these newly described sub-components with a focus on what we understand, and, more interestingly, on what we still don't understand about them. [less ▲]

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See detailOn the large deformation of axisymmetrique bodies: experimental and numerical studies.
Belkhiri, Laid; Charlier, Robert ULg; Detraux, J. M.

in Proceedings of the Int. Conf. on Numerical Methods in Engineering (1985, January)

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See detailOn the Laser Cladding of Ti Alloy Ti-6Al-4V with Low Laser Power
Mertens, Anne ULg; Paydas, Hakan ULg; Tchuindjang, Jérôme Tchoufack ULg et al

in Pilchak, Adam (Ed.) Proc. of Ti 2015: 13th World Conference on Titanium, Vol. 6: Additive and Near Net Shape Manufacturing (in press)

Laser cladding is an economic layer-by-layer near-net-shape process for the production and the repair of metallic parts. In this process, a metallic powder is projected onto a substrate while being molten ... [more ▼]

Laser cladding is an economic layer-by-layer near-net-shape process for the production and the repair of metallic parts. In this process, a metallic powder is projected onto a substrate while being molten by a laser beam. Laser sources with fairly high power – i.e. typically 2kW − are often used to ensure short building times and high productivity. However, this approach has limitations. Indeed, it is very difficult to produce thin walls at high laser power. Moreover, an increase of the incident energy may give rise to a relatively coarser microstructure, and this will in turn affect the mechanical properties of the component. In order to address these issues, this paper aims at assessing the potential of a laser source with a lower maximum power of 300W to enhance the flexibility of the process. Two types of samples – i.e. thin walls or bulk deposits − were produced at low laser power from alloy Ti-6Al-4V. Their geometry, microstructures and local hardness are characterised and correlated with the thermal history experienced during fabrication. [less ▲]

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See detailOn the Light Curve of HD 27563
Manfroid, Jean ULg

in Information Bulletin on Variable Stars (1989), 3297

Not Available

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See detailOn the line parameters for the X 1sigma+g (1–0) infrared quadrupolar transitions of 14N2
Goldman, Aaron; Tipping, R.H.; Ma, Q. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2007), 103

Re-examination of the 14N2 X 1sigma+g (1–0) line parameters in the HITRAN database showed that the vibration–rotation interaction effect on the line intensities has been neglected, and that the halfwidths ... [more ▼]

Re-examination of the 14N2 X 1sigma+g (1–0) line parameters in the HITRAN database showed that the vibration–rotation interaction effect on the line intensities has been neglected, and that the halfwidths are not compatible with experimental and theoretical studies. New line parameters have been generated, which improve the consistency and accuracy in individual N2 line retrievals from atmospheric spectra. Unresolved line shape issues require further studies. [less ▲]

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See detailOn the linearity of ESO CCD#9 at CAT+CES.
Gosset, Eric ULg; Magain, Pierre ULg

in The Messenger (1993), 73

Not Available

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See detailOn the link between design against fatigue and fracture mechanics
Debongnie, Jean-François ULg

in ASME (Ed.) Proceedings of the 2000 ASME Design Engineering Technical Conferences (2000, September)

The gradient method, often used in design against fatigue, is analyzed from the point of view of its link with fracture mechanics. By a logical step, a law is deduced for the variation of the endurance ... [more ▼]

The gradient method, often used in design against fatigue, is analyzed from the point of view of its link with fracture mechanics. By a logical step, a law is deduced for the variation of the endurance limit in terms of the relative stress gradient. The proposed expression is found to be in good agreement with older ones and may easily be extended to a large class of materials. [less ▲]

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See detailOn the Linkage between Teichoic Acid and the Glycopeptide in the Cell Wall of Staphylococcus Aureus
Strominger, Jack L.; Ghuysen, Jean-Marie ULg

in Biochemical & Biophysical Research Communications (1963), 12(5), 418-424

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See detailOn the local operational geomagnetic index K calculation
Stankov, Stan; Stegen, Koen; Wautelet, Gilles ULg et al

Poster (2010, May 06)

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See detailOn the master painter of the tomb of Amenhotep Sise, second High Priest of Amun Under the reign of Thutmose IV (TT 75)
Laboury, Dimitri ULg

in Cooney, Kathlyn; Jasnow, Richard (Eds.) Volume dedicated to a distinguished colleague (in press)

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See detailOn the mechanism of elasto-inertial turbulence
Dubief, Yves; Terrapon, Vincent ULg; Soria, Julio

in Physics of Fluids (2013), 25(110817), 1-16

Elasto-inertial turbulence (EIT) is a new state of turbulence found in inertial flows with polymer additives. The dynamics of turbulence generated and controlled by such additives is investigated from the ... [more ▼]

Elasto-inertial turbulence (EIT) is a new state of turbulence found in inertial flows with polymer additives. The dynamics of turbulence generated and controlled by such additives is investigated from the perspective of the coupling between polymer dynamics and flow structures. Direct numerical simulations of channel flow with Reynolds numbers ranging from 1000 to 6000 (based on the bulk and the channel height) are used to study the formation and dynamics of elastic instabilities and their effects on the flow. The flow topology of EIT is found to differ significantly from Newtonian wall-turbulence. Structures identified by positive (rotational flow topology) and negative (extensional/compressional flow topology) second invariant Qa isosurfaces of the velocity gradient are cylindrical and aligned in the spanwise direction. Polymers are significantly stretched in sheet-like regions that extend in the streamwise direction with a small upward tilt. The Qa cylindrical structures emerge from the sheets of high polymer extension, in a mechanism of energy transfer from the fluctuations of the polymer stress work to the turbulent kinetic energy. At subcritical Reynolds numbers, EIT is observed at modest Weissenberg number (Wi, ratio polymer relaxation time to viscous time scale). For supercritical Reynolds numbers, flows approach EIT at large Wi. EIT provides new insights on the nature of the asymptotic state of polymer drag reduction (maximum drag reduction), and explains the phenomenon of early turbulence, or onset of turbulence at lower Reynolds numbers than for Newtonian flows observed in some polymeric flows. [less ▲]

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See detailOn the micro-scale modelling by homogenization schemes in geomechanics
Levasseur, Séverine ULg; Collin, Frédéric ULg; Charlier, Robert ULg et al

in USNCTAM 2010 (2010)

The mechanical behaviors of geomaterials are significantly affected by the presence of voids or cracks-like defects. The modeling of such behavior is classically performed by considering purely ... [more ▼]

The mechanical behaviors of geomaterials are significantly affected by the presence of voids or cracks-like defects. The modeling of such behavior is classically performed by considering purely macroscopic or micromechanically-based damage models. In the perspective of applications in civil engineering or in geomechanics, we propose in this paper to evaluate a homogenization approach, based on Mori-Tanaka scheme, applied to micro-cracked materials. In order to provide an appropriate interpretation of the nonlinear behavior at macro-scale, the crack-induced damage is coupled to friction phenomena on closed cracks lips. The predictions of the coupled model are first analyzed on laboratory tests performed on Callovo-Oxfordian Clay. Then, they are extended to a numerical analysis of excavation damaged zones around tunnels [less ▲]

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See detailOn the Model Validation in Nonlinear structural Dynamics,
Kerschen, Gaëtan ULg

Doctoral thesis (2002)

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See detailON THE MODELING OF ADHESIVE CONTACT AND STICTION FAILURE IN MICRO-SWITCHES
Wu, Ling ULg; Noels, Ludovic ULg; Golinval, Jean-Claude ULg

in Ouisse (FEMTO-ST – ENSMM, France); Deü (CNAM, FR), J.F. (Eds.) MEDYNA 2013 Proceedings (2013, April)

Undesirable stiction, which results from contact between surfaces, is a major failure mode in micro-switches. Indeed the adhesive forces can become so important that the two surfaces remain permanently ... [more ▼]

Undesirable stiction, which results from contact between surfaces, is a major failure mode in micro-switches. Indeed the adhesive forces can become so important that the two surfaces remain permanently glued, limiting the life-time of the MEMS. This is especially true when contact happens between surfaces where elasto-plastic asperities deform permanently until the surfaces reach plastic accommodation, increasing the surface forces. To predict this behavior, a micro adhesive-contact model is developed, which accounts for the surfaces topography evolutions during elasto-plastic contacts. This model can be used at a higher scale to study the MEMS behavior, and thus its life-time. For illustration purpose, an electrostatic-structural analysis is performed on a micro-switch. [less ▲]

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See detailOn the modeling of convective drying tests on soil samples in non-isothermal conditions
Gerard, Pierre ULg; Léonard, Angélique ULg; Charlier, Robert ULg et al

in Tsotsas, E.; Metzger, T.; Peglow, M. (Eds.) Proceedings of IDS 2010 - Drying 2010 (2010, October)

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See detailOn the modelling of compacted bentonite under in situ conditions
Dieudonné, Anne-Catherine ULg; Talandier, Jean; Charlier, Robert ULg

Conference (2015)

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See detailOn the modelling of compressed long plates related to sheet-section behaviour
Hofmeyer, H.; Jaspart, Jean-Pierre ULg

in Proceedings of the Fifth International Conference on Thin-Walled Structures (2008)

Detailed reference viewed: 11 (1 ULg)