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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 ▲]

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See detailParametric study of metal/polymer multilayer coatings for temperature wrinkling prediction
Zhang, Lihong ULg; Habraken, Anne ULg; Ben Bettaieb, Amine ULg et al

in Journal of Materials Engineering & Performance (2013), 22(9), 2437-2445

Detailed reference viewed: 20 (9 ULg)
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See detailParametric study of the numerical modelling for semi-rigid joints
Jaspart, Jean-Pierre ULg; Gerardy, J. C.; Maquoi, René ULg

in proceedings of the Annual technical session and meeting of the SSRC (1991)

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See detailA parametric study on the emissions from an HCCI alternative combustion engine resulting from the auto-ignition of primary reference fuels
Machrafi, Hatim ULg; Cavadias, Simeon; Amouroux, Jacques

in Applied Energy (2008), 85(8), 755-764

The homogeneous charge compression ignition is an alternative combustion technology that can reduce automobile pollution, provided that the exhaust emission can be controlled. A parametric study can be ... [more ▼]

The homogeneous charge compression ignition is an alternative combustion technology that can reduce automobile pollution, provided that the exhaust emission can be controlled. A parametric study can be useful in order to gain more understanding in the emission reduction possibilities via this new combustion technology. For this purpose, the inlet temperature, the equivalence ratio and the compression ratio are changed, respectively, from 30 to 70 degrees C, 0.28 to 0.41 and 6 to 14. Also the diluting, thermal and chemical effects of exhaust gas recirculation were studied. The emission of CO, CO2, O-2 and hydrocarbons has been measured using primary reference fuels. It appears that an increase in the inlet temperature, the EGR temperature, the equivalence ratio and the compression ratio results into a decrease of the emissions of CO and the hydrocarbons of up to 75%. The emission of CO2 increased, however, by 50%. The chemical parameters showed more complicated effects, resulting into a decrease or increase of the emissions, depending on whether the overall reactivity increased or not. If the reactivity increased, generally, the emissions of CO and hydrocarbons increased, while that of CO2 increased. The increase of CO2 emissions could be compensated by altering the compression ratio and the EGR parameters, making it possible to control the emission of the HCCI engine. (c) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailParametrical study on the behaviour of steel and composite cellular beams under fire conditions
Vassart, Olivier; Bailey, C. G.; Bihina, Gisèle et al

in Kodur, Venkatesh; Franssen, Jean-Marc (Eds.) Structures in Fire. Proceedings of the Sixth International Conference (2010)

This paper describes an extensive parametric study on the behaviour of cellular beam under fire conditions. Different finite element models using shell elements were developed considering both material ... [more ▼]

This paper describes an extensive parametric study on the behaviour of cellular beam under fire conditions. Different finite element models using shell elements were developed considering both material and geometrical non-linearity; CAST3M [1], ANSYS [2] and another one in SAFIR [3]. They were calibrated on the basis of a new experimental test campaign performed in the scope of the project FICEB+ [4] funded by the Research Fund for Coal and Steel. The comparison between the finite element prediction and actual experimental results showed a good agreement in terms of failure modes, load deflection relationship and ultimate loads. At failure, temperature measured during the fire tests indicated that failure arising by web post buckling of cellular beams in fire cannot be simply estimated by applying temperature dependent reduction factors on strength alone, as given in codes. A design model representing the behaviour of cellular beam in fire conditions has been developed by Vassart [5-7]. This design model is able to predict the complex behaviour of cellular beam in case of fire comprising web-post buckling and Vierendeel bending, as well as standard flexural bending. The results of the Finite Element Models are compared in terms of critical temperatures and failure mode obtained using the design model. This paper also contains some tests results that were used to calibrate the FEM model and the comparison between analytical and FEM models. [less ▲]

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See detailThe Parametrized Diastolic Filling Formalism: Application in the Asklepios Population
Claessens, Tom; Muhammad Waheed, Raja; Pironet, Antoine ULg et al

in Conference Program ASME 2011 Summer Bioengineering Conference (2011, June)

Detailed reference viewed: 35 (7 ULg)
See detailLes paramyxovirus des mammifères marins
Jauniaux, Thierry ULg

in proceeding of the conference (2004)

Detailed reference viewed: 4 (0 ULg)
See detailParana Medio, a multipurpose transport development (Argentina).
Marchal, Jean ULg

Report (1988)

Detailed reference viewed: 16 (0 ULg)