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See detailParamètres individuels et familiaux de la dynamique d'insertion professionnelle
Gavray, Claire ULg

in SES REGION WALLONNE (Ed.) Module social de l'annuaire statistique de Wallonie (1999)

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See detailParamètres influençant la structure et la fonction du globule rouge chez le cheval
Portier, Karine; Kirschvink, Nathalie; Fellmann, Nicole et al

in Annales de Médecine Vétérinaire (2007), 151(2), 101-106

The erythrocyte, as an oxygen carrier, is submitted to areas where oxidative stress is important. The maintenance of the structure and fluidity of its membrane is essential to its function. Indeed, oxygen ... [more ▼]

The erythrocyte, as an oxygen carrier, is submitted to areas where oxidative stress is important. The maintenance of the structure and fluidity of its membrane is essential to its function. Indeed, oxygen must diffuse through the membrane and the deformability of the cell is essential to its progression through capillaries. The structure and, as a consequence, the fluidity of the membrane influence these properties. The red blood cell presents antioxydant capacities, but in some cases, free radical production is increased and exceeds antiradical defences leading to irreversible defects of the membrane, and, as a consequence, of its function. Horse erythrocyte seems to be more sensitive to oxidative stress than other species and resulting hemorheological changes could have tissular and organic consequences. [less ▲]

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See detailParamètres sanguins et bilan azoté chez le taurillon culard en engraissement intensif ou en croissance faible suivie de croissance accélérée
Van Eenaeme, Christian ULg; Hornick, Jean-Luc ULg; Clinquart, Antoine ULg et al

in 9èmes Journées des Recherches sur l'Alimentation et la Nutrition des Herbivores (1994)

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See detailParametric accelerated failure time models with random effects and an application to kidney transplant survival
Lambert, Philippe ULg; Collett, Dave; Kimber, Alan et al

in Statistics in Medicine (2004), 23

Accelerated failure time models with a shared random component are described, and are used to evaluate the effect of explanatory factors and different transplant centres on survival times following kidney ... [more ▼]

Accelerated failure time models with a shared random component are described, and are used to evaluate the effect of explanatory factors and different transplant centres on survival times following kidney transplantation. Different combinations of the distribution of the random effects and baseline hazard function are considered and the fit of such models to the transplant data is critically assessed. A mixture model that combines short- and long-term components of a hazard function is then developed, which provides a more flexible model for the hazard function. The model can incorporate different explanatory variables and random effects in each component. The model is straightforward to fit using standard statistical software, and is shown to be a good fit to the transplant data. [less ▲]

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See detailA PARAMETRIC ANALYSIS FOR THE DAFALIAS-KALIAKIN BOUNDING SURFACE VISCOPLASTIC MODEL-BASED ON THE DIFLUPRESS LD TEST
LEIDWANGER-RABIS, Cathy; CHAMBON, René; CATEL, P. et al

in Computers & Geotechnics (1995), 17(4), 473-505

In order to predict delayed settlements of heavy structures, the authors decided to use the elasto-viscoplastic model of Dafalias-Kaliakin. To identify the parameters of the constitutive equations, they ... [more ▼]

In order to predict delayed settlements of heavy structures, the authors decided to use the elasto-viscoplastic model of Dafalias-Kaliakin. To identify the parameters of the constitutive equations, they use above all the data of a new in-situ test, the Diflupress L.D. designed to approach the creep behavior of soil. In a first section, the principle of the model is presented. Then, the important parameters of the model are identified, mostly from in-situ test data since the laboratory tests data are not numerous and reliable. Finally, a study of sensitivity on the parameters which influence the viscoplastic response of the model is made. [less ▲]

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See detailParametric analysis of the development and expression of ethanol-induced behavioral sensitization in female Swiss mice: effects of dose, injection schedule, and test context.
Didone, Vincent ULg; Quoilin, Caroline ULg; Tirelli, Ezio ULg et al

in Psychopharmacology (2008), 201(2), 249-60

RATIONALE: Repeated administrations of ethanol induce a progressive and enduring increase in its locomotor stimulant effects, a phenomenon termed behavioral sensitization that has not been systematically ... [more ▼]

RATIONALE: Repeated administrations of ethanol induce a progressive and enduring increase in its locomotor stimulant effects, a phenomenon termed behavioral sensitization that has not been systematically characterized. OBJECTIVE: The aim of the present studies was to characterize the development and expression of ethanol sensitization in female Swiss mice by examining (1) the doses of ethanol that induce behavioral sensitization, (2) the doses of acute ethanol challenges that are necessary to express behavioral sensitization, (3) the effects of the intervals between administrations, and (4) the context dependency of ethanol sensitization. MATERIALS AND METHODS: Mice were i.p. injected for 8 days with various ethanol doses, and locomotion was recorded for 5 min. Two days after the last sensitization session, ethanol sensitization was tested in 30-min test sessions. RESULTS: Mice repeatedly injected with 2.5 g/kg ethanol showed a progressive (200-300%) increase in locomotor activity. In response to a 2.5 g/kg ethanol challenge, the mice repeatedly treated with doses above 1.5 g/kg showed a significant sensitization. Following the induction of sensitization with the maximally effective sensitizing dose (2.5 g/kg), mice showed greater activation after challenges with 1.5, 2.0, 2.5, and 3.0 g/kg ethanol. The intervals (24, 48, or 96 h) between ethanol injections did not affect the induction or expression of sensitization. Finally, sensitization to 2.5 g/kg ethanol was expressed regardless of the context in which it was induced. CONCLUSIONS: Female Swiss mice develop a robust context-independent sensitization after repeated ethanol injections at all doses above 1.5 g/kg, including highly sedative doses such as 4 g/kg. [less ▲]

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See detailParametric analysis of the lateral-torsional buckling resistance of steel beams in case of fire
Vila Real, Paulo; Lopes, Nuno; Simoes da Silva, Luis et al

in Fire Safety Journal (2007), 42(6-7, SEP-OCT), 416-424

Numerical modelling of the lateral-torsional buckling of steel beams at elevated temperature has shown that the beam design curve from EN 1993-1-2 is over-conservative in the case of non-uniform bending ... [more ▼]

Numerical modelling of the lateral-torsional buckling of steel beams at elevated temperature has shown that the beam design curve from EN 1993-1-2 is over-conservative in the case of non-uniform bending. Based on the newly proposed methodology for cold design from the EN 1993-1-1, an improved proposal for the lateral-torsional buckling of unrestrained steel beams subjected to fire is presented in this paper that addresses the issue of the influence of the loading type, the steel grade, the pattern of the residual stresses (hot-rolled or welded sections) and the ratio h/b, between the depth h and the width b of the cross-section on the resistance of the beam, achieving better agreement with the numerical behaviour while maintaining safety. The proposal is found to be safe and accurate through an extensive comparison with the results of FEM numerical simulations of more than 5000 beams. A statistical study of the results is performed, showing the accuracy of the improved proposal presented in this paper. (C) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailA parametric approach to colour rendering
Embrechts, Jean-Jacques ULg

in Die Farbe (1986), 32/33

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See detailParametric conditional mean and variance testing with censored data
Heuchenne, Cédric ULg; González Manteiga, Wenceslao; Sánchez Sellero, Cesar

in H. Skiadas, Christos (Ed.) Recent Advances in Applied Stochastic Models and Data Analysis. (2007)

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See detailParametric conditional mean and variance testing with censored data
Heuchenne, Cédric ULg; González Manteiga, Wenceslao; Sanchez Sellero, Cesar

in ASMDA2007 Proceedings (2007)

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See detailParametric conditional variance estimation in location-scale models with censored data
Heuchenne, Cédric ULg; Laurent, Géraldine ULg

E-print/Working paper (2014)

Suppose the random vector (X,Y) satisfies the regression model Y=m(X)+sigma(X)*varepsilon, where m(.)=E(Y|.), sigma²(.)=Var(Y|.) belongs to some parametric class {sigma _theta(.): theta in Theta} and ... [more ▼]

Suppose the random vector (X,Y) satisfies the regression model Y=m(X)+sigma(X)*varepsilon, where m(.)=E(Y|.), sigma²(.)=Var(Y|.) belongs to some parametric class {sigma _theta(.): theta in Theta} and varepsilon is independent of X. The response Y is subject to random right censoring and the covariate X is completely observed. A new estimation procedure is proposed for sigma_theta(.) when m(.) is unknown. It is based on nonlinear least squares estimation extended to conditional variance in the censored case. The consistency and asymptotic normality of the proposed estimator are established. The estimator is studied via simulations and an important application is devoted to fatigue life data analysis. [less ▲]

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See detailParametric Cubic Equations For Modeling Moldboard Plow Surfaces
Ravonison, Nm.; Destain, Marie-France ULg

in Soil & Tillage Research (1994), 31(4), 363-373

Mouldboard shape identification is needed to compare and analyse the performance of different plough bottoms. The paper presents a method for describing an existing mouldboard mathematically. The ... [more ▼]

Mouldboard shape identification is needed to compare and analyse the performance of different plough bottoms. The paper presents a method for describing an existing mouldboard mathematically. The technique used is based on a Bezier form of three dimensional parametric cubics and it focuses on an algorithm to improve the efficiency of approximation of a theoretical surface and the actual one. The method is well suited to describing mouldboard designs. [less ▲]

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See detailParametric definition of sandblasted and polished concrete surfaces
Courard, Luc ULg

in Sandrolini, Franco (Ed.) ICPIC 98 (1998)

A lot of considerations have been developed on the influence of surface roughness on the adherence of a repairing systems on a concrete support : sandblasting, hammering, hydroblasting, acid attacks,… ... [more ▼]

A lot of considerations have been developed on the influence of surface roughness on the adherence of a repairing systems on a concrete support : sandblasting, hammering, hydroblasting, acid attacks,… have been analysed by a lot of authors. This presentation gives a parametric interpretation of a sandblasted surface in comparison with a polished concrete. A stylus is walked along the surface to be analysed and the profile is continuously registered. The filtration of the electric signal is realised in order to separate waviness and roughness. The effect of the stylus/component profile contact on the validity of the measurement results is of prime importance. Profilometry and surfometry are mathematically described by statistical and amplitude parameters. The analysis of surfometry profiles let us to observe and quantify the shape regularity and the isotropic effect of sandblasting. The bearing ratio curves permit to quantify the volume of voids able to absorb the slurry or the repairing mortar applied on the support. The difference, between the two surface treatments is clearly quantified and related to adherence properties of some hydraulic binders. [less ▲]

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See detailA Parametric Design Based Approach to Structural Shape Optimization
ZHANG, W. H.; Beckers, Pierre ULg; Duysinx, Pierre ULg et al

Conference given outside the academic context (1993)

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See detailA Parametric Distance Function Approach for Malmquist Productivity Index Estimation
Fuentes, Hugo J.; Grifell-Tatjé, Emili; Perelman, Sergio ULg

in Journal of Productivity Analysis (2001), 15

Malmquist indexes of productivity are generally estimated using index number techniques or non-parametric frontier approaches. The aim of this paper is to showthat Malmquist indexes can be estimated in a ... [more ▼]

Malmquist indexes of productivity are generally estimated using index number techniques or non-parametric frontier approaches. The aim of this paper is to showthat Malmquist indexes can be estimated in a similar way using parametric-deterministic or parametric-stochastic frontier approaches. To allow a multi-output multi-input technology and for technical change in production, we adopt an output distance function which is specified in a translog form. We then show that using the estimated parameters, several radial distance functions can be calculated and combined in order to estimate and decompose the productivity index. Finally, this approach is applied to a panel of Spanish insurance companies. The main results confirm those generally obtained for financial services: very low rates of growth and technical change in spite of a rapid deregulation process and expansion of activity. [less ▲]

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See detailParametric numerical study of seismic slope stability and the Newmark method
Havenith, Hans-Balder ULg; Torgoev, Almazbek ULg; Lamair, Laura ULg

Conference (2013, April)

2D dynamic modelling of seismic slope stability is applied to a landslide-prone area in Central Asia, the Mailuu-Suu Valley, situated in the south of Kyrgyzstan. The calculations are made with models ... [more ▼]

2D dynamic modelling of seismic slope stability is applied to a landslide-prone area in Central Asia, the Mailuu-Suu Valley, situated in the south of Kyrgyzstan. The calculations are made with models constructed from over 30 profiles located in the target area, presenting different geological, tectonic and morphological settings. One part of the profiles were selected within landslide zones, the other part was selected in stable areas. Many of the landslides are complex slope failures involving falls, rotational sliding and/or planar sliding and flows. These input data were extracted from a 3D structural geological model built with the GOCAD software. Geophysical and geomechanical parameters were defined on the basis of results obtained by multiple surveys performed in the area over the past 15 years. These include geophysical investigation, seismological experiments and ambient noise measurements. Dynamic modelling of slope stability is performed with the UDEC version 4.01 software that is able to compute deformation of discrete elements. Inside these elements both elasto-plastic and purely elastic materials (similar to rigid blocks) were tested. Various parameter variations were tested to assess their influence on the final outputs. For a few models groundwater flow is included. The total parametric study involved more than 100 different models (about 800 computation hours). Preliminary results allow us to compare Newmark displacements computed using different GIS approaches (Jibson et al., 1998; Miles and Ho, 1999, among others) with the displacements computed using the original Newmark method (Newmark, 1965, here simulated seismograms were used) and displacements produced along joints by the corresponding 2D dynamical models. The generation of seismic amplification and its impact on peak-ground-acceleration, Arias Intensity and permanent slope movements (total and slip on joints) is assessed for numerous morphological-lithological settings (curvature, slope angle, surficial geology, various layer dips and orientations) throughout the target area. The final results of our studies should allow us to define the limitations of the simplified GIS-based Newmark displacement modelling; thus, the verified method would make landslide susceptibility and hazard mapping in seismically active regions more reliable. [less ▲]

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See detailParametric numerical study of seismic slope stability and verification of the Newmark method
Torgoev, Almazbek ULg; Havenith, Hans-Balder ULg

in Ugai, K; Wakai, A; Yagi, H (Eds.) Proceedings of the International Symposium on Earthquake-induced landslides, Kiryu, Japan, 2012 (2012, December)

2D dynamic modelling of seismic slope stability is applied to a landslide-prone area in Central Asia, the Mailuu-Suu Valley, situated in the south of Kyrgyzstan. The calculations are made with models ... [more ▼]

2D dynamic modelling of seismic slope stability is applied to a landslide-prone area in Central Asia, the Mailuu-Suu Valley, situated in the south of Kyrgyzstan. The calculations are made with models constructed from over 30 profiles located in the target area, presenting different geological, tectonic and morphological settings. One part of the profiles were selected within landslide zones, the other part was selected in stable areas. Many of the landslides are complex slope failures involving falls, rotational sliding and/or planar sliding and flows. These input data were extracted from a 3D structural geological model built with the GOCAD software. Geophysical and geomechanical parameters were defined on the basis of results obtained by multiple surveys performed in the area over the past 15 years. These include geophysical investigation, seismological experiments and ambient noise measurements. Dynamic modelling of slope stability is performed with the UDEC version 4.01 software that is able to compute deformation of discrete elements. Inside these elements both elasto-plastic and purely elastic materials (similar to rigid blocks) were tested. Various parameter variations were tested to assess their influence on the final outputs. For a few models groundwater flow is included. The total parametric study involved more than 100 different models (about 800 computation hours). [less ▲]

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See detailParametric Study for the Creation of the Interface between Concrete and Repair Products
Courard, Luc ULg

in Materials and Structures (2000), 33

An analysis as large as possible presents factors acting when a repair system comes into contact with a concrete support. The appetency of the first one for the second is defined from the properties of ... [more ▼]

An analysis as large as possible presents factors acting when a repair system comes into contact with a concrete support. The appetency of the first one for the second is defined from the properties of the support and the new layer – essentially in its liquid phase – as well as from the environmental conditions. These properties are cited or explained for each material: roughness, porosity, superficial cohesion and interstitial water into concrete, nature and concentration of the binder, rigidity modulus, capillary succion for repair systems. The thermodynamic properties of the materials as well as transport mechanisms – diffusion, capillary succion – at the interface and roughness of the concrete support are particularly developed. A sequential flow sheet related to the parameters influencing the creation of the interface is proposed. [less ▲]

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See detailParametric study of ductile moment resisting frames. First step for Eurocode 8 calibration.
Sanchez-Ricart, L.; Plumier, André ULg

in Earthquake Engineering & Structural Dynamics (2008)

A parametric study of 13,608 ductile Moment-Resisting Steel Frames (MRSF) designed according to Eurocode 3 and Eurocode 8 is performed. A flowchart for the evaluation of the seismic-resistant capacity of ... [more ▼]

A parametric study of 13,608 ductile Moment-Resisting Steel Frames (MRSF) designed according to Eurocode 3 and Eurocode 8 is performed. A flowchart for the evaluation of the seismic-resistant capacity of the designed frames is developed based on the N2 method. The design structural overstrength, the ductility supply, the plastic redistribution parameter, the supply reduction factor and the performance ratio of the frames under study are analysed. The 13,608 designed frames under study have performance ratios higher than one mostly due to the high values of design structural overstrength, showing that the seismic supply produced by Eurocode 3 and Eurocode 8 restrains are always higher than the seismic demand. [less ▲]

Detailed reference viewed: 94 (3 ULg)