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See detailForecast verification using skill scores and wavelets. Application to a two-way nested primitive equation model of the Ligurian Sea.
Alvera Azcarate, Aïda ULg; Barth, Alexander ULg; Rixen, M. et al

Conference (2003, April)

The verification of a forecast is an important part of a forecasting process. It allows to establish the quality of a model, and to make the pertinent improvements. The verification methodology may be ... [more ▼]

The verification of a forecast is an important part of a forecasting process. It allows to establish the quality of a model, and to make the pertinent improvements. The verification methodology may be designed to detect the errors contained in the model. The verification process consist in the comparison of the model results with a reference system (as sample climatology, or the output of a reference version of the model), in order to establish the accuracy and skill of the first one. The Anomaly Correlation Coefficient, the Brier Skill Score and the Root Mean Square Error are used in the present work to quantify the predictive skill. The disadvantage of this kind of measures is its over simplification. They are very useful, since the comparison between the model and the reference system is reduced to a limited set of numbers to establish the error, but it also results in a great loss of information. The method presented here combines the skill score analysis with a more detailed study. The use of wavelet transforms is shown to be useful, because of their capacity to localize in time and frequency the analysed signal. The signal is decomposed at different spatial scales, where the skill score methods can be applied separately. The information obtained with this method is more detailed, and scales where the largest errors occur can be easily identified. This combination of methods has been applied to a two-way nested primitive equation model of the Ligurian Sea. The scale decomposition allows to better understand the differences between the model and the observed field, to establish the weaknesses and strengths of the model, and to propose the possible improvements that can be done. [less ▲]

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See detailForecasting Daily Solar Energy Production Using Robust Regression Techniques
Louppe, Gilles ULg; Prettenhofer, Peter

Conference (2014, February 05)

We describe a novel approach to forecast daily solar energy production based on the output of a numerical weather prediction (NWP) model using non-parametric robust regression techniques. Our approach ... [more ▼]

We describe a novel approach to forecast daily solar energy production based on the output of a numerical weather prediction (NWP) model using non-parametric robust regression techniques. Our approach comprises two steps: First, we use a non-linear interpolation technique, Gaussian Process regression (also known as Kriging in Geostatistics), to interpolate the coarse NWP grid to the location of the solar energy production facilities. Second, we use Gradient Boosted Regression Trees, a non-parametric regression technique, to predict the daily solar energy output based on the interpolated NWP model and additional spatio-temporal features. Experimental evidence suggests that two aspects of our approach are crucial for its effectiveness: a) the ability of Gaussian Process regression to incorporate both input and output uncertainty which we leverage by deriving input uncertainty from an ensemble of 11 NWP models and including convidence intervals alongside the interpolated point estimates and b) the ability of Gradient Boosted Regression Trees to handle outliers in the outputs by using robust loss functions - a property that is very important due to the volatile nature of solar energy output. We evaluated the approach on a dataset of daily solar energy measurements from 98 stations in Oklahoma. The results show a relative improvement of 17.17% and 46.19% over the baselines, Spline Interpolation and Gaussian Mixture Models, resp. [less ▲]

Detailed reference viewed: 85 (13 ULg)
Peer Reviewed
See detailForecasting epidemic outbreaks ofwheat leaf blotch based on meteorological parameters
Junk, Jürgen; El Jarroudi, Moussa ULg; Pogoda, Frederik et al

Poster (2010, April 12)

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See detailForecasting Septoria tritici on winter wheat in the Grand-Duchy of Luxembourg from 2000 to 2005.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, H. et al

in Bibliotheca Fragmenta Agronomica - Book of Proceedings (2006), 11(2), 751-752

This papers presents the results of a wheat diseases model called PROCULTURE for the prediction of septoriosis in the Grand Duchy of Luxembourg

Detailed reference viewed: 17 (3 ULg)
See detailForecasting Skill Assessment of a Doubly, Two-Way Nested Model of the Ligurian Sea driven by Assimilation of Sea Surface Temperature
Barth, Alexander ULg; Alvera Azcarate, Aïda ULg; Rixen, M. et al

Conference (2003)

The GHER 3D primitive equation model is implemented with threedifferent resolutions: a low resolution model (1/4Ž°) coveringthe whole Mediterranean Sea, an intermediate resolution model (1/20Ž°)of the ... [more ▼]

The GHER 3D primitive equation model is implemented with threedifferent resolutions: a low resolution model (1/4Ž°) coveringthe whole Mediterranean Sea, an intermediate resolution model (1/20Ž°)of the Liguro-Provençal basin and a high resolution model (1/60Ž°)simulating the fine mesoscale structures in the Ligurian Sea. Boundaryconditions and the averaged fields (feedback) are exchanged betweentwo successive nesting levels. The model of the Ligurian Sea is also coupled with the assimilationpackage SESAM. It allows to assimilate satellite data and in situobservations using the local adaptative SEEK (Singular EvolutiveExtended Kalman) filter. Instead of evolving the error space by thenumerically expensive Lyapunov equation, a simplified algebraicequation depending on the misfit between observation and modelforecast is used. Starting from the 1st January 1998 the low and intermediate resolutionmodels are spun up for 18 months. The initial conditions for theLigurian Sea are interpolated from the intermediate resolutionmodel. The three models are then integrated until August 1999. Duringthis period AVHRR Sea Surface Temperature of the Ligurian Sea isassimilated. The results are validated by using CTD and XBT profilesof the SIRENA cruise from the SACLANT Center. In a second validation exercise,the AVHRR SST and model forecast %(not yet affected by the SST used for validation) are decomposed at different scalesusing a horizontal wavelet transform.The processes characteristic for each scale are isolated in the model and the SST images.The error statistics calculated on the wavelet amplitudes can thus be related to the ability of the model in forecasting the correspondingmarine processes. In a second validation exercise, the AVHRR SST and model forecast areboth decomposed at different scales using a horizontal wavelet transform.The characteristic processes for each scale are isolated in the modeland the SST images. The error statistics calculated on the waveletamplitudes can thus be related to the ability of the model inforecasting the corresponding marine processes. [less ▲]

Detailed reference viewed: 8 (2 ULg)
See detailForecasting the Dourbes K index by using solar wind parameters
Andonov, Borislav; Kutiev, Ivan; Warnant, René ULg et al

in Proceedings of Beacon Satellite Symposium 2004 (2005)

Detailed reference viewed: 44 (0 ULg)
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Peer Reviewed
See detailForecasting the Effects of Lateral Flooding Basins by Transient Surface Flows Computations
Pirotton, Michel ULg

in Vith Conference the Comtemporary Problems of Hydroengineering (1996, May 06)

Detailed reference viewed: 3 (1 ULg)
See detailForecasts of black and red conditions for RTK users
Warnant, René ULg; Lejeune, Sandrine; Nebdi, Hamid

Report (2004)

Detailed reference viewed: 19 (1 ULg)
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See detailForeign Aid Transaction Costs: What are they and when are they minimised?
Paul, Elisabeth ULg; Vandeninden, Frieda ULg

in Development Policy Review (2012), 30(3),

'Transaction costs' are commonly referred to in the recent literature on aid effectiveness. Aid transaction costs, however, have been neither consistently defined nor measured. This article defines aid ... [more ▼]

'Transaction costs' are commonly referred to in the recent literature on aid effectiveness. Aid transaction costs, however, have been neither consistently defined nor measured. This article defines aid transaction costs as all the economic costs associated with aid management that add no value to aid delivery. This enables the 'net' transaction costs that should be minimised to be identified. An analytical framework is then developed for assessing these costs. This allows the effectiveness of different aid modalities to be compared, according to the characteristics of the aid transaction. The article shows that the choice of aid modality should depend on these characteristics and, therefore, that the minimisation of transaction costs should not be an end in itself. [less ▲]

Detailed reference viewed: 12 (3 ULg)
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See detailForeign Exchange Risk Exposure: Survey and Suggestions
Muller, Aline ULg; Verschoor, Willem

in Journal of Multinational Financial Management (2006), 16(4), 385-410

Detailed reference viewed: 27 (5 ULg)
See detailForeign languages in primary and pre-school education : a review of recent research within the European Union
Blondin, Christiane ULg; Candelier, M.; Edelenbos, P. et al

Book published by Centre for Information on Language Teaching (CILT) (1998)

Detailed reference viewed: 277 (0 ULg)
See detailForeign Origin Politicians in Belgium
Martiniello, Marco ULg

Scientific conference (1996, January 29)

Detailed reference viewed: 1 (0 ULg)
See detailForeign Origin Politicians in Belgium
Martiniello, Marco ULg

in Martiniello, Marco (Ed.) Multicultural Policies and the State: a comparison of two European societies (1998)

Detailed reference viewed: 15 (2 ULg)
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See detailThe Foreign Series by Herder Verlag by 1900: International Catholic Literature
Ceballos Viro, Alvaro ULg

in Spiers, John (Ed.) The Culture of the Publisher's Series, Volume 2. Nationalisms and the National Canon (2011)

Detailed reference viewed: 29 (3 ULg)
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See detailForeign Trade and Exchange Risk Exposure: A Firm and Industry Analysis of Eastern European Multinationals
Muller, Aline ULg; Verschoor, Willem

in Emerging Markets Review (2007), 8(3), 218-229

Detailed reference viewed: 20 (3 ULg)
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See detailForeigness or Englishness? = Estrangeiros ou Britânicos?
Gillet, Lucie ULg

in Acta Scientiarum. Language and Culture (2008), 30(1), 111-112

Detailed reference viewed: 40 (6 ULg)
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See detailForensic Cadaveric Decomposition Profiling by GC×GC-TOFMS Analysis of VOCs
Focant, Jean-François ULg; Stefanuto, Pierre-Hugues ULg; Brasseur, Catherine ULg et al

in Chemical Bulletin of Kazakh National University (2013), 72(4), 177-186

Detailed reference viewed: 8 (3 ULg)