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See detailApplication du raisonnement clinique à l'interprétation d'un bilan de reproduction bovine
Hanzen, Christian ULg

Conference given outside the academic context (2009)

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See detailApplication du Simplified Acute Physiology Score II (SAPS II) dans une unite de soins intensifs medicaux
Ghuysen, Alexandre ULg; Lambermont, Bernard ULg; D'Orio, Vincenzo ULg

in Annales Françaises d'Anesthésie et de Réanimation (2000), 19(7), 510-6

OBJECTIVE: Our study was to assess the validity of SAPS II (New Simplified Acute Physiology Score) to predict the probability of in hospital mortality, in a cohort of patient admitted to a medical ... [more ▼]

OBJECTIVE: Our study was to assess the validity of SAPS II (New Simplified Acute Physiology Score) to predict the probability of in hospital mortality, in a cohort of patient admitted to a medical intensive care unit. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: Out of 467 the 525 patients admitted were included. SAPS score and in hospital mortality prediction were calculated for each of them. RESULTS: In this group, SAPS II offered a satisfactory discrimination power with an area under the curve of 0.843. However, calibration showed a lack of fit (chi 2 = 28.5, P < 0.001), with an overall under prediction of mortality (observed versus expected ratio of 1.12). CONCLUSION: This SAPS II lower predicting accuracy in a specific population and for individual outcome prediction may reduce its interest in clinical decision-making. [less ▲]

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See detailL'application du système Bedaux dans l'industrie belge des années '30
Geerkens Provin, Eric ULg

in Barjot, Dominique (Ed.) Le travail à l'époque contemporaine (2004)

Pour lever l'apparente contradiction entre l'importance attribuée au système Bedaux et sa diffusion relativement limitée, il s'agit d'abord de mesurer avec précision son extension dans le tissu industriel ... [more ▼]

Pour lever l'apparente contradiction entre l'importance attribuée au système Bedaux et sa diffusion relativement limitée, il s'agit d'abord de mesurer avec précision son extension dans le tissu industriel belge des années '30 et de caractériser les entreprises utilisatrices, après avoir rappelé les principaux traits de ce système de gestion de la main-d'œuvre. La prise en compte des avantages que le système Bedaux offre aux entreprises dans différentes conjonctures, et des motifs de rejet ou d'acceptation conditionnelle par les travailleurs et leurs organisations, permettent de comprendre l'écho donné au système, au-delà de l'importance quantitative de son extension. [less ▲]

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See detailUne application du télétraitement : le prêt de livres à la Bibliothèque Générale de l'Université de Liège
Krins, Alfred ULg

in Archives et Bibliothèques de Belgique = Archief en Bibliotheekwezen in België (1976), 47(1-2), 91-103

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See detailApplication for proteomic techniques in studying osteoarthritis: a review
Gharbi, Myriam; Deberg, Michelle ULg; Henrotin, Yves ULg

in Frontiers in Physiology (2011), 2(90), 1-11

Detailed reference viewed: 20 (6 ULg)
See detailApplication of a 3-D Super Ensemble to ocean forecast
Lenartz, Fabian ULg; Barth, Alexander ULg; Beckers, Jean-Marie ULg et al

Conference (2009)

Super Ensemble (SE) techniques have recently allowed improving the forecast of various important oceanographic parameters, such as the significant wave height, the speed of sound or the surface drift, by ... [more ▼]

Super Ensemble (SE) techniques have recently allowed improving the forecast of various important oceanographic parameters, such as the significant wave height, the speed of sound or the surface drift, by correcting the prediction at a single or multiple locations, where data were available during the whole training period. However, nowadays common observation systems, such as satellite imagery or drifters, do not always provide information at the exact same locations, hence it is necessary to generalize the approach in order to take benefit of every image or track available. In this study, we try and apply a SE, fed with remote sensing and gliders data, to 3-D hydrodynamic models. The basic idea on which rely the SE methods is that a certain combination of several model runs and possibly data could yield better results than just one single model, even if it has a higher temporal or spatial resolution. As the most efficient techniques are the ones using observations, they rapidly developed and increased in complexity by copying what had been done in the data assimilation community; getting from the simple ensemble mean of the model outputs to their linear combination based on a particle filter. In our present study, we have decided to use the Kalman filter (KF) as it alleviates the need of an a priori determination of the training period length, and does not require the run of a very large ensemble of members. In addition, we apply it in a 3-D framework in order to take benefit of the spatial information contained by each source of measurements. For example, satellite images of sea surface temperature (SST) are very useful to correct the value of this parameter, but depending on the structure of the water column, it can also give a precious guess of how warm or cold is the ocean at 20 m deep. In our experiment the domain of interest is the Ligurian Sea during the last week of September, when part of the set-up for the CalVal08 campaign (SiC Charles Trees) had already taken place. The data assimilated during the training of the filter are SST images from AVHRR, as well as temperature and salinity profiles from two Rutgers University gliders. The models used for the study are three nested models of NCOM, run without data assimilation. The two considered variables are the temperature and the salinity. As our method is designed to work in a multivariate way, salinity forecast can possibly be improved by observing temperature profiles. Statistics are computed for both the training and the testing periods with an independent set of data. In four test cases, we review the impact of both the nature of the assimilated data, and the formulation of the model covariance matrix. At the end, we show that, on the basis of previous model outputs from which we’ve drawn an estimate of the model covariance, RMS error of the forecast in the whole 3-D domain can be reduced by 30%, thanks to the only assimilation of satellite SST images. [less ▲]

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See detailApplication of a chemoselective ligation strategy to the M1 factor of virginiamycin
Nott, Katherine ULg; Tatibouët, Arnaud; Rollin, Patrick et al

Poster (2008, March 26)

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See detailApplication of a damage model to an aluminium alloy
Castagne, Sylvie; Habraken, Anne ULg; Cescotto, Serge ULg

in International Journal of Damage Mechanics (2003), 12(1), 5-30

An energy-based isotropic elastoplastic model coupled to damage is implemented in the finite element code LAGAMINE developed for more than fifteen years in the MSM department. In this model, based on the ... [more ▼]

An energy-based isotropic elastoplastic model coupled to damage is implemented in the finite element code LAGAMINE developed for more than fifteen years in the MSM department. In this model, based on the local approach of ductile fracture, effective stresses associated to damage variables are introduced. The damage law allows a continuous description of crack appearance. After a brief description of the model, its identification and its validation for an aluminum alloy are presented. Finally, the research of a global rupture criterion associated to this model is introduced. [less ▲]

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See detailApplication of a data minig based technique for the evaluation of transmission expansion plans
Druet, Christophe; Vassena, Stefano; Rousseaux, Patricia ULg et al

in Proceedings of the 15th Power System Computation Conference (PSCC) (2005)

This paper describes a methodology for the study of long-term network planning under uncertainties. In this approach the major external uncertainties during the planning horizon are modelled as macro ... [more ▼]

This paper describes a methodology for the study of long-term network planning under uncertainties. In this approach the major external uncertainties during the planning horizon are modelled as macro-scenarios at different future time instants. The random nature of actual operating conditions is taken into account by using a probabilistic model of micro-scenarios based on past statistics. MonteCarlo simulations are used to generate and simulate a specified number of scenarios. Data mining techniques are then applied to the simulations results collected in a database, so as to extract information and to rank scenarios and network reinforcements according to different performance criteria. The paper describes the application of this approach on a real transmission planning problem faced by the Belgian transmission system operator. [less ▲]

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See detailApplication of a data-interpolating variational analysis (DIVA) tool to physical and biogeochemical measurements covering the Black Sea
Joassin; Beckers, Jean-Marie ULg; Boicenco, L. et al

in Climate change in the Black Sea, hypthesis, observations, trends scenarios and mitigation strategy for the ecosystem (2008)

The European project SESAME (Southern European Seas: Assessing and Modelling Ecosystem changes) is dedicated to the assessment of ecological changes in the Mediterranean and Black seas during these last ... [more ▼]

The European project SESAME (Southern European Seas: Assessing and Modelling Ecosystem changes) is dedicated to the assessment of ecological changes in the Mediterranean and Black seas during these last decades. This assessment will be done by combining statistical analysis of available data and the development of a 3D hydrodynamical-biogeochemical model. Data available since 1960 for the Black Sea from the databases MEDAR and NATO have been completed with data provided by SESAME partners. These data sets have been analyzed using DIVA, a geostatistical analysis tool developed by the GHER laboratory of the University of Liège. The DIVA analysis relies on a finite element resolution, taking into account coastlines, sub-basins, and advection by ocean currents. DIVA analysis generates spatially interpolated fields for biogeochemical and physical variables. Outputs consist in sets of analysis as well as error fields, and colorimetric scaled maps related to several depth layers. Biogeochemical variables considered consist in measures of chlorophyll, inorganic nutrients concentration, and phytoplankton abundances; physical variables consist in temperature and salinity. These treatments of the Black sea data sets offer an overview of the global pattern of the Black sea biogeochemical structure, and its evolution through the time periods concerned by the project. The interpolated fields generated by the DIVA tool will be used to validate the outputs of the 3D hydrodynamical-biogeochemical model developed for the north-western shelf of the Black sea in the framework of SESAME. [less ▲]

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See detailApplication of a diffusion model to predict drying kinetics changes under variable conditions: experimental and simulation study
Bennamoun, Lyes ULg; Belhamri, Azeddine; Ali-Mohamed, Adbéraman

in Fluid Dynamics and Materials Processing (2009), 5(2),

Detailed reference viewed: 21 (4 ULg)
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See detailApplication of a High-Order Upwind Finite-Volume Scheme to 2D Cascade Flows Using a Multi-Block Approach
Rogiest, Pascal; Léonard, Olivier ULg; Essers, Jean-André ULg

in Proceedings of the 12th ISABE Conference (1995)

Detailed reference viewed: 20 (2 ULg)
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See detailApplication of a mass consistent flow model to study the CO2 mass balance of forests
Canepa, Elisa; Georgieva, Emilia; Manca, Giovanni et al

in Agricultural and Forest Meteorology (2010), 150(5), 712-723

The reconstruction of the wind field is one of the main issues in the mass conservation approach for calculation of CO2 advection in forest ecosystems and still remains a challenging problem. In the ... [more ▼]

The reconstruction of the wind field is one of the main issues in the mass conservation approach for calculation of CO2 advection in forest ecosystems and still remains a challenging problem. In the current study, we present an advancement of this approach: the use of a mass consistent flow model (WINDS) which takes into account measured wind data and simulates the 3-D flow field, while imposing airmass conservation in the control volume. We apply the WINDS model to alculate half hourly mean total advective flux terms at the CarboEurope-IP site of Renon (Bozen/Bolzano Autonomous Province), in Northern Italy. The data used refer to six time periods of one day representing three different meteorological conditions observed during the ADVEX campaign from April to September 2005. Current results are compared with results obtained in two other studies for the same time periods. One of these studies is based on the mass conservation approach as well, but applies only interpolations to reconstruct the wind field; the other study makes use of tilt correction (sectorwise planar fit method) for the vertical wind component. In the present study, the effect of the wind field reconstruction method on the estimation of the advective fluxes is discussed. The possibility of using reduced input wind data (i.e. number of towers) for WINDS is also investigated. The results suggest that the representativeness of wind tower measurements is of primary importance for estimating CO2 advection terms and their uncertainty in complex terrain. [less ▲]

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See detailApplication of a Mixed Normal Mixture Model for the Estimation of Mastitis-Related Parameters
Detilleux, Johann ULg; Leroy, P. L.

in Journal of Dairy Science (2000), 83(10), 2341-9

The current methodology for estimating genetic parameters for SCC (SCS) does not account for the difference in SCS between healthy cows and cows with an intramammary infection (IMI). We propose a two ... [more ▼]

The current methodology for estimating genetic parameters for SCC (SCS) does not account for the difference in SCS between healthy cows and cows with an intramammary infection (IMI). We propose a two-component finite mixed normal mixture model to estimate IMI prevalence, separate SCS subpopulation means, individual posterior probabilities of IMI, and SCS variance components. The theory is presented and the expectation-conditional maximization algorithm is utilized to compute maximum likelihood estimates. The methodology is illustrated on two simulated data sets based on the current knowledge of SCS parameters. Maximum likelihood estimates of IMI prevalence and SCS subpopulation means were close to simulated values, except for the estimate of IMI prevalence when both subpopulations were almost confounded. Individual posterior probabilities of IMI were always higher among infected than among healthy cows. Error and additive variance components obtained under the mixture model were closer to simulated values than restricted maximum likelihood estimates obtained assuming a homogeneous SCS distribution, especially when subpopulations were completely separated and when mixing proportion was highest. Convergence was linear and rapid when priors were chosen with caution. The advantages of the methodology are demonstrated, and its feasibility for large data sets is discussed. [less ▲]

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See detailApplication of a multi-model approach to account for conceptual model and scenario uncertainties in groundwater modelling
Rojas, Rodriguo; Kahunde, Samalie; Peeters, Luk et al

in Journal of Hydrology (2010), 394(3-4), 416-435

Groundwater models are often used to predict the future behaviour of groundwater systems. These models may vary in complexity from simplified system conceptualizations to more intricate versions. It has ... [more ▼]

Groundwater models are often used to predict the future behaviour of groundwater systems. These models may vary in complexity from simplified system conceptualizations to more intricate versions. It has been recently suggested that uncertainties in model predictions are largely dominated by uncertainties arising from the definition of alternative conceptual models. Different external factors such as climatic conditions or groundwater abstraction policies, on the other hand, may also play an important role. Rojas et al. (2008) proposed a multimodel approach to account for predictive uncertainty arising from forcing data (inputs), parameters and alternative conceptualizations. In this work we extend upon this approach to include uncertainties arising from the definition of alternative future scenarios and we apply the extended methodology to a real aquifer system underlying the Walenbos Nature Reserve area in Belgium. Three alternative conceptual models comprising different levels of geological knowledge are considered. Additionally, three recharge settings (scenarios) are proposed to evaluate recharge uncertainties. A joint estimation of the predictive uncertainty including parameter, conceptual model and scenario uncertainties is estimated for groundwater budget terms. Finally, results obtained using the improved approach are compared with the results obtained from methodologies that include a calibration step and which use a model selection criterion to discriminate between alternative conceptualizations. Results showed that conceptual model and scenario uncertainties significantly contribute to the predictive variance for some budget terms. Besides, conceptual model uncertainties played an important role even for the case when a model was preferred over the others. Predictive distributions showed to be considerably different in shape, central moment and spread among alternative conceptualizations and scenarios analysed. This reaffirms the idea that relying on a single conceptual model driven by a particular scenario, will likely produce bias and under-dispersive estimations of the predictive uncertainty. Multimodel methodologies based on the use of model selection criteria produced ambiguous results. In the frame of a multimodel approach, these inconsistencies are critical and can not be neglected. These results strongly advocate the idea of addressing conceptual model uncertainty in groundwater modelling practice. Additionally, considering alternative future recharge uncertainties will permit to obtain more realistic and, possibly, more reliable estimations of the predictive uncertainty. [less ▲]

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See detailApplication of a new optimization strategy for the separation of tertiary alkaloids extracted from Strychnos usambarensis leaves
Nistor, Iolanda ULg; Cao, Martine ULg; Debrus, Benjamin ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 56

The HPLC separation of six alkaloids extracted from Strychnos usambarensis leaves has been developed and optimized by means of a powerful methodology for modelling chromatographic responses, based on ... [more ▼]

The HPLC separation of six alkaloids extracted from Strychnos usambarensis leaves has been developed and optimized by means of a powerful methodology for modelling chromatographic responses, based on three steps, i.e. design of experiments (DoE), independent component analysis (ICA) and design space (DS). This study was the first application of a new optimization strategy to a complex natural matrix. The compounds separated are the isomers isostrychnopentamine and strychnopentamine, 10-hydroxyusambarine and 11-hydroxyusambarine, also strychnophylline and strychnofoline. Three LC parameters have been optimized using a multifactorial design comprising 29 experiments that includes 2 center point replicates. The parameters were the percentage of organic modifiers used at the beginning of a gradient profile which consisted in different proportions of methanol (MeOH) and acetonitrile (MeCN), the gradient time to reach 70% of organic modifiers starting from the initial percentage and the percentage of MeCN found in the mobile phase. Subsequent to the experimental design application, predictive multilinear models were developed and used in order to provide optimal analytical conditions. The optimum assay conditions were: methanol/acetonitrile-sodium pentane sulfonate (pH 2.2; 7.5 mM) (33.4:66.6, v/v) at a mobile phase flow rate of 1mL/min during a 40.6 minutes gradient time. The initial organic phase contained 3.7% MeCN and 96.3% MeOH. The method showed good agreement between the experimental data and predictive value throughout the studied parameters space. Improvement of the analysis time and optimized separation for the compounds of interest was possible due to the original and powerful tools applied. Finally, this study permitted the acquisition of isomers profiles allowing the identification of the optimal collecting period of Strychnos usambarensis. [less ▲]

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See detailApplication of a new thermo-mechanical model for study of the nuclear waste disposal in clay rocks
Dizier, Arnaud ULg; François, Bertrand; Collin, Frédéric ULg et al

Conference (2010, October 05)

Detailed reference viewed: 23 (9 ULg)