Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Peer Reviewed
See detailEnseigner les nombres complexes dans une perspective historique
Rosseel, Hilda; Schneider-Gilot, Marguerite ULiege

Conference (2003)

Detailed reference viewed: 7 (0 ULiège)
Peer Reviewed
See detailEnseigner massivement la littérature jeunesse : la Formation en Ligne Ouverte à tous de l'Université de Liège
Centi, Valérie; D'Anna, Vincianne; Delbrassine, Daniel ULiege et al

Conference (2016, July 20)

Detailed reference viewed: 58 (4 ULiège)
See detailEnseigner pour diminuer les inégalités : point de vue sur la profession des enseignants et le rôle de la formation
Beckers, Jacqueline ULiege; Aelterman, Antonia

in École School+ : Plate-forme pour une école sans exclusion (2008)

Detailed reference viewed: 23 (2 ULiège)
See detailEnseigner, entre réussir et comprendre, théorie implicite de l'éducation et pensée des enseignants-experts : essai de recadrage socioconstructiviste
Crahay, Marcel ULiege

in Otte, Jeannine (Ed.) Recherche, pratique et savoirs en éducation (2002)

Detailed reference viewed: 138 (11 ULiège)
Peer Reviewed
See detailEnseignes de pèlerinage à l'effigie de saint Remacle, dans Orfèvrerie mosane, p. 147-152
George, Philippe ULiege

in L'oeuvre de la Meuse. Feuillets de la Cathédrale de Liège 2014 (2014)

Detailed reference viewed: 26 (1 ULiège)
See detailUn ensemble augusto-tibérien découvert à Aalter (Flandre orientale, Belgique) et les premières importations de céramique gallo-belge dans le civitas menapiorum
Deru, Xavier ULiege

in Rivet L. (Ed.) Actes de la Société française d’étude de la céramique en Gaule, Langres 2007 (2007)

Detailed reference viewed: 32 (0 ULiège)
Peer Reviewed
See detail(ensemble de la publication depuis 1970)
Klinkenberg, Jean-Marie ULiege

in Français Moderne (Le) (1970)

Detailed reference viewed: 19 (2 ULiège)
Full Text
See detailEnsemble des observations physiques de la planète Mars à Louvain en 1888 par M. Terby : rapport de F. Folie
Folie, François ULiege

in Bulletins de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique (1888), 3e série, t. 17(4), 309-311

The author establishes a report on the Mr. Terby’s work on all the planet Mars physical observations in Leuven in 1888

Detailed reference viewed: 13 (0 ULiège)
See detailL’ensemble Musique Nouvelle et les musiques nouvelles en Wallonie et à Bruxelles
Pirenne, Christophe ULiege; Dufour, Valérie; Decroupet, Pascal

Book published by Mardaga (2004)

Detailed reference viewed: 37 (3 ULiège)
Full Text
Peer Reviewed
See detailAn ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces
Ruiz-Ramos, M.; Ferrise, R.; Rodríguez, A. et al

Conference (2016, March)

Detailed reference viewed: 66 (3 ULiège)
Full Text
Peer Reviewed
See detailEnsemble perturbation smoother for optimizing tidal boundary conditions by assimilation of High-Frequency radar surface currents - application to the German Bight
Barth, Alexander ULiege; Alvera Azcarate, Aïda ULiege; Gurgel, Klaus-Werner et al

in Ocean Science (2010), 6(1), 161-178

High-Frequency (HF) radars measure the ocean surface currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift ... [more ▼]

High-Frequency (HF) radars measure the ocean surface currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift. Sequential assimilation methods updating the model state have been proven successful to correct the density-driven currents by assimilation of observations such as sea surface height, sea surface temperature and in-situ profiles. However, the situation is different for tides in coastal models since these are not generated within the domain, but are rather propagated inside the domain through the boundary conditions. For improving the modeled tidal variability it is therefore not sufficient to update the model state via data assimilation without updating the boundary conditions. The optimization of boundary conditions to match observations inside the domain is traditionally achieved through variational assimilation methods. In this work we present an ensemble smoother to improve the tidal boundary values so that the model represents more closely the observed currents. To create an ensemble of dynamically realistic boundary conditions, a cost function is formulated which is directly related to the probability of each boundary condition perturbation. This cost function ensures that the boundary condition perturbations are spatially smooth and that the structure of the perturbations satisfies approximately the harmonic linearized shallow water equations. Based on those perturbations an ensemble simulation is carried out using the full three-dimensional General Estuarine Ocean Model (GETM). Optimized boundary values are obtained by assimilating all observations using the covariances of the ensemble simulation. [less ▲]

Detailed reference viewed: 155 (12 ULiège)
See detailEnsemble smoother for optimizing tidal boundary conditions and bottom roughness by assimilation of High-Frequency Radar surface currents
Barth, Alexander ULiege; Alvera Azcarate, Aïda ULiege; Staneva, J. et al

Conference (2009, September)

High-Frequency (HF) radars measure the ocean currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift. Sequential ... [more ▼]

High-Frequency (HF) radars measure the ocean currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift. Sequential assimilation methods updating the model state have been proven successful to correct the density-driven currents by assimilation of observations such as sea surface height, sea surface temperature and in-situ profiles. However, the situation is different for tides in coastal models since these are not generated within the domain, but are rather propagated inside the domain through the boundary conditions. For improving the modeled tidal variability it is therefore not sufficient to update the model state via data assimilation without updating the boundary conditions. The optimization of boundary conditions to match observations inside the domain is traditionally achieved through variational assimilation methods. In this work we present an ensemble smoother to improve the tidal boundary values so that the model represents more closely the observed currents. To create an ensemble of dynamically realistic boundary conditions, a cost function is formulated which is directly related to the probability of each perturbation. This cost function ensures that the perturbations are spatially smooth and that the structure of the perturbations satisfies approximately the harmonic linearized shallow water equations. Based on those perturbations an ensemble simulation is carried out using the full three-dimension General Estuarine Ocean Model (GETM). Optimized boundary values are obtained using all observations within the assimilation period using the covariances of the ensemble simulation. [less ▲]

Detailed reference viewed: 54 (10 ULiège)
See detailEnsemble smoother for optimizing tidal boundary conditions and wind forcing by assimilation of High-Frequency Radar surface currents measurements of the German Bight
Barth, Alexander ULiege; Alvera Azcarate, Aïda ULiege; Staneva, Joanna et al

Conference (2010)

An ensemble smoother scheme is presented to assimilate HF radar surface currents to improve tidal boundary conditions and wind forcings of a circulation model of the German Bight. To create an ensemble of ... [more ▼]

An ensemble smoother scheme is presented to assimilate HF radar surface currents to improve tidal boundary conditions and wind forcings of a circulation model of the German Bight. To create an ensemble of dynamically realistic tidal boundary conditions, a cost function is formulated which is directly related to the probability of each perturbation. This cost function ensures that the perturbations are spatially smooth and that the structure of the perturbations satisfies approximately the harmonic linearized shallow water equations. Based on those perturbations an ensemble simulation is carried out using the full three-dimensional General Estuarine Ocean Model (GETM). Optimized boundary values are obtained using all observations within the assimilation period using the covariances of the ensemble simulation. The approach acts like a smoother scheme since all observations are taken into account. Since the scheme aims to derive the optimal perturbation, it might be called Ensemble Perturbation Smoother. The final analysis is obtained by rerunning the model using the optimal perturbation to the boundary conditions. The analyzed model solution satisfies thus the model equations exactly and does not suffer from spurious adjustments often observed with sequential assimilation schemes. Model results are also compared to independent tide gage data. The assimilation did also reduce the model error compared to those sea level observations. The same scheme has also been used to correct surface winds. Surface winds are crucial for accurately modeling the marine circulation in coastal waters. The method is validated directly by comparing the analyzed wind speed to in situ measurements and indirectly by assessing the impact of the corrected winds on sea surface temperature (SST) relative to satellite SST. [less ▲]

Detailed reference viewed: 27 (1 ULiège)
See detailEnsemble-based assimilation of high-frequency radar surface currents in regional ocean models
Barth, Alexander ULiege; Alvera Azcarate, Aïda ULiege; Beckers, Jean-Marie ULiege et al

Conference (2010)

The results of coastal ocean models depend critically on the accuracy of boundary and initial conditions and atmospheric forcing. The precision of coastal ocean models is limited among others by ... [more ▼]

The results of coastal ocean models depend critically on the accuracy of boundary and initial conditions and atmospheric forcing. The precision of coastal ocean models is limited among others by uncertainty in those forcing fields. Since high-frequency (HF) radar installations provide measurements over a relatively large area, the assimilation of these data has a high potential to reduce the errors in ocean models and to provide a dynamically consistent estimation of the ocean circulation. The assimilation of HF radar data is not without its own challenges: the spatial variation of the surface currents uncertainty, the high temporal resolution of HF radar data, the simultaneous presence of a wide range of processes with distinct spatial and temporal scales (tides and other surface gravity waves, mesoscale and wind-driven circulation), and the generally strong sensitivity of regional models to errors in the boundary conditions and atmospheric forcings. These processess are important aspects to consider in the application of data assimilation methods to HF radar measurements. The results of two data assimilation experiments on the West Florida Shelf (WFS) and the German Bight are presented. HF radar currents are assimilated in a nested West Florida Shelf based on an ensemble of model realizations with different wind forcings. The model is sequentially updated and a filter is implemented to reduce spurious surface-gravity waves. Results of the WFS model assimilating surface currents show an improvement of the model currents not only at the surface but also at depth compared to independent ADCP observations. This West Florida Shelf assimilation experiment does not include tides. Tides are not generated within the domain, but are rather propagated inside the domain through the boundary conditions. The potential of using HF radar data to reduce errors in tidal boundary conditions is shown in a model setup of the German Bight. For improving the modeled tidal variability it is not sufficient to update the model state without updating the boundary conditions. An ensemble smoother to improve the tidal boundary values is presented and validated with independent HF radar measurements and tide-gage data. The ensemble-scheme is also applied to improve the wind forcing by assimilation of surface currents. The improvement of the analyzed wind forcing is assessed by using in-situ wind measurements. [less ▲]

Detailed reference viewed: 35 (2 ULiège)
Full Text
See detailLes ensembles de données comptables centralisés: un exemple d'analyse, un débat sur leur aide potentielle en gestion de PME
De Bruyn, Christian; Corhay, Albert ULiege

in Wilkin, Jacques; Dubois, Daniel (Eds.) L'informatique de gestion à la portée des P.M.E. (1981)

Detailed reference viewed: 32 (5 ULiège)