Publications ORBi OA
Bookmark and Share    
Full Text
See detailUse of spot/vegetation in different versions of the European crop growth monitoring system.
Piccard, I.; Eerens, H.; Oger, Robert ULg et al

in Veroustraete, F.; Bartholomé, E.; Verstraeten, W. W. (Eds.) Proceedings of the 2nd international vegetation user conference, 1998-2004 : 6 years of operational activities (2005)

The Crop Growth Monitoring System (CGMS) is a GIS-application, developed and operated since 1989 by the MARS-unit of the EU Joint Research Centre. The primary objective is the timely forecasting of the ... [more ▼]

The Crop Growth Monitoring System (CGMS) is a GIS-application, developed and operated since 1989 by the MARS-unit of the EU Joint Research Centre. The primary objective is the timely forecasting of the yields of the main crops on the Pan-European continent.To reach this goal, CGMS combines all available (historical and actual) resources: official crop statistics, daily meteorological data, specific crop and soil parameters, the predictions of the (spatialized) crop growth model WOFOST, and the 10-daily composite images of NOAA-AVHRR and SPOT-VEGETATION. In recent years CGMS has been implemented in different regions of the world, also beyond Europe. This paper gives a brief overview of some of these applications, with emphasis on the remote sensing component, especially SPOT-VEGETATION. In 2000, JRC outsourced the practical operation of CGMS to a consortium composed by Alterra (main tasks, agrometeorological model), MeteoConsult (meteo-provider) and VITO (remote sensing). MARS-STAT delivers the European yield forecasts to the EU statistical office EUROSTAT, in view of the follow-up of market prices and the achievement of the CAP-regulations. MARS-FOOD particularly deals with important food producing areas (Russia, Mercosur) and famine-threatened zones in Africa (IGAD-zone). The long-term goal is to steadily fill the actual data gaps (crop areas, parameters, meteo,…) so that, in time, the full CGMS (incl. the model) could be applied on these areas (or even globally). Specific versions of CGMS emerged in different countries (Finland, Spain, Kazakhstan,…), running with more detailed input data. One example is the so-called B-CGMS which has been operating since 1998 on behalf of the Belgian ministry of agriculture, in a collaboration between ULg-Arlon, CRA-Gembloux and VITO. Since 2002, the B-CGMS group publishes monthly bulletins with forecasts on crop yields, areas and productions. The areas are delivered by the IACS (annually updated GIS of all crop parcels, maintained for the EU-CAP). Together with local partners, the same Belgian group is now implementing CGMS in China’s north-eastern province Heilongjiang, part of former Manchuria and China’s main producer of soybean, maize and singlecropped rice. Special attention is being paid to the steady drying-out of this region, which 50 years ago was mainly covered by wetlands and forests. Climate change and mismanaged paddy irrigation are leading to a dramatic lowering of the water tables. Technically, this paper will focus on the main deliverables derived from NOAA- AVHRR and SPOT- VEGETATION. This includes pre/post-processing, extraction of biophysical vegetation state parameters (NDVI, SAVI, fAPAR, Dry Matter Productivity), differences with regard to the historical year (VCI, VPI, etc.), quicklooks, etc. Of most concern however is the “ unmixing” approach, which attempts to conform the remote sensing data (image format, 1 km-pixels, different crops mixed) to the CGMS-standards (databases with district/crop as spatial/thematic units). If the low/medium resolution sensors (AVHRR, VEGETATION, MODIS, MERIS,..) want to maintain their role in this agricultural domain, this problem has to be solved. Otherwise, the floor is open for new, revolutionary initiatives such as DMC (Disaster Monitoring Constellation: daily global coverage at 32m resolution). [less ▲]

Detailed reference viewed: 44 (5 ULg)
Full Text
See detailMonitoring of the 2003 summer drought in Belgium with the NDWI applied on spot-vegetation data.
Horion, Stéphanie; Eerens, Herman; Tychon, Bernard ULg et al

in Veroustraete, F.; Bartholomé, E.; Verstraeten, W. W. (Eds.) Proceedings of the 2nd international vegetation user conference. 1998-2004 : 6 years of operational activities. (2005)

The summer 2003 was abnormally hot, sunny and dry. The average temperatures from June to August were the highest ever recorded in the Belgian reference meteorological station of Uccle, but also in other ... [more ▼]

The summer 2003 was abnormally hot, sunny and dry. The average temperatures from June to August were the highest ever recorded in the Belgian reference meteorological station of Uccle, but also in other countries of western and central Europe such as Portugal, Germany, Switzerland and the United Kingdom. Many human activities were affected by these particular climatic conditions, among which agriculture.The Normalized Difference Water Index (NDWI) applied on ten-daily SPOT- VEGETATION imagery is one of the drought indicators which could serve for the localisation of drought affected areas in Belgium. In this paper preliminary results show that detection of dry events is possible using historical averages of NDWI. Relative NDWI images can be used to monitor the development of the summer drought.These images are computed by the weighted difference between the NDWI values during this summer and its value at the same period in a reference year, which corresponds to a normal year in terms of rainfall availability. Analysis of the relation between NDWI and NDVI behaviours show that the green biomass influences the NDWI value especially during the growing season. More accurate study has to be done to individualize the specific NDWI behaviour during dry events. In perspectives, index validation with meteorological parameters and with the Relative Soil Moisture Index, which is an output of the Belgian Crop Growth Monitoring System, will improve this study. [less ▲]

Detailed reference viewed: 36 (2 ULg)
Full Text
See detailEvolution possible de la PAC à l'horizon 2020. Poursuite du glissement vers "le 2ème pilier", cadrage par rapport à l'OMC. Quels sont les scénarios, les adaptations possibles ?
Burny, Philippe ULg

in Centre wallon de Recherches Agronomiques (Ed.) La 11ème Journée Fourrage Actualités "Comment prendre en compte le long terme dans l'orientation donnée à nos systèmes d'élevages herbagers ?" (2005)

Detailed reference viewed: 22 (3 ULg)
Full Text
See detailL’enseignement de l’éducation physique en Communauté française de Belgique
Cloes, Marc ULg

in Revue de la Fédération des Educateurs et Educatrices Physiques Enseignants du Québec (2005), 17(2), 16-18

Detailed reference viewed: 58 (4 ULg)
Full Text
See detailThe UVES Paranal Observatory Project: a public library of high resolution stellar spectra
Jehin, Emmanuel ULg; Bagnulo, S.; Melo, C. et al

in Hill, V. (Ed.) From Lithium to Uranium: Elemental Tracers of Early Cosmic Evolution (2005)

The UVES Paranal Observatory Project (POP), is an ESO public database of about 400 stars whose high quality spectra were obtained with UVES, the high resolution spectrometer of the VLT. All stars were ... [more ▼]

The UVES Paranal Observatory Project (POP), is an ESO public database of about 400 stars whose high quality spectra were obtained with UVES, the high resolution spectrometer of the VLT. All stars were observed with two instrument modes, in order to cover almost completely the optical region (300-1000 nm). The resolving power is about 80000, and for most of the spectra, the typical S/N ratio is 300-500 in the V band. Program stars fall into two groups, stars belonging to open clusters IC2391 and NGC6475, and bright field stars. For field stars, the only selection criterion applied was to cover the largest possible variety of spectral types in the HR diagram, including peculiar objects, e.g., Ap and Bp stars, Wolf-Rayet stars, Be stars, carbon stars and metal poor stars. The spectra have been reduced, coadded and merged and various products can be downloaded from a public area. For each star the final spectrum may be displayed through a dedicated user-friendly Spectral Preview Interface. The database is accessible at http://www.eso.org/uvespop [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
See detailStudy of the liquid fraction and thermophysical properties of semi-solid steels and application to the simulation of inductive heating for thixoforming
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Carton, Marc ULg et al

in Bananic, Dorel (Ed.) Advanced Methods in Material Forming (2005)

The thixoforming of steels is so complex that it requires more investigations regarding both the materials and the technical tools dedicated to the elaboration of the process. In this paper we will show ... [more ▼]

The thixoforming of steels is so complex that it requires more investigations regarding both the materials and the technical tools dedicated to the elaboration of the process. In this paper we will show the experimental determination of appropriate solidus-liquidus interval on eight different steel compositions. This critical parameter was obtained using Differential Scanning Calorimetry. The paper also presents the results of thermophysical property determination. These parameters are important for the inductive heating phase of a semi-solid forming (SSF) process. Thanks to the simulations of the inductive heating process, the other main results consist on the developments of the heating techniques that are suitable for the achieving of the sine qua none condition to the semi-solid process, which is the uniform temperature distribution in the reheated billet. [less ▲]

Detailed reference viewed: 74 (11 ULg)
Full Text
Peer Reviewed
See detailL'accueil de la décision-cadre relative au mandat d'arrêt européen en Belgique
Flore, Daniel ULg

in Droit de l'Union européenne-Colloques (2005)

L'élaboration d'un droit pénal européen est un processus complexe constitué d'étapes successives. On aborde ici la question de l'accueil de la décision-cadre relative au mandat d'arrêt européen en ... [more ▼]

L'élaboration d'un droit pénal européen est un processus complexe constitué d'étapes successives. On aborde ici la question de l'accueil de la décision-cadre relative au mandat d'arrêt européen en Belgique. [less ▲]

Detailed reference viewed: 40 (4 ULg)
Full Text
Peer Reviewed
See detailWind pressure distribution influence on natural ventilation for different incidences and environment densities
van Moeseke, G.; Gratia, E.; Reiter, Sigrid ULg et al

in Energy & Buildings (2005), 37

Detailed reference viewed: 89 (7 ULg)
Full Text
See detailA noção de texto em Hjelmslev
Badir, Sémir ULg

in CASA : Cadernos de Semiótica Aplicada (2005), 3(2),

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailIn situ photoacoustic spectroscopy of phycobiliproteins in Gracilaria chilensis
Saavedra, R.; Figueroa, Maximiliano ULg; Wandersleben, T. et al

in Journal de Physique IV (2005), 125

Phycobiliproteins, the main polypeptidic components of the phycobilisomes (PBS), are biolog- ical macromolecules arranged in complex interaction systems to perform light harvesting and conduction. The ... [more ▼]

Phycobiliproteins, the main polypeptidic components of the phycobilisomes (PBS), are biolog- ical macromolecules arranged in complex interaction systems to perform light harvesting and conduction. The optical properties of these systems can hardly be studied by conventional spectroscopic techniques. Furthermore this techniques also involve laborious chemical extraction methods. Photoacoustic (PA) spec- troscopy was successfully applied to an in situ study of the phycobiliproteins expression in the eukaryotic red algae: Gracilaria chilensis. [less ▲]

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailQuantum critical 5f electrons avoid singularities in U(Ru,Rh)(2)Si-2
Silhanek, Alejandro ULg; Harrison, N.; Batista, C. D. et al

in Physical Review Letters (2005), 95(2),

We present specific heat measurements of 4% Rh-doped URu2Si2 at magnetic fields around the proposed metamagnetic transition field H(m)similar to 34 T, revealing striking similarities to the isotructural ... [more ▼]

We present specific heat measurements of 4% Rh-doped URu2Si2 at magnetic fields around the proposed metamagnetic transition field H(m)similar to 34 T, revealing striking similarities to the isotructural Ce analog CeRu2Si2 for H > H-m. This suggests that strongly renormalized hybridized-band models apply equally well to both systems. The vanishing bandwidths as H -> H-m are consistent with a quantum-critical point close to H-m. The existence of a phase transition into an ordered phase in the vicinity of H-m for 4% Rh-doped URu2Si2, but not for CeRu2Si2, is consistent with a stronger superexchange in the case of the U 5f system. Irreversible processes at the transition indicate a strong coupling of the 5f orbitals to the lattice, most suggestive of electric quadrupolar order. [less ▲]

Detailed reference viewed: 8 (1 ULg)
Full Text
Peer Reviewed
See detailLa notion de confiance mutuelle : l'"alpha" ou l'"oméga" d'une justice pénale européenne
Flore, Daniel ULg

in La confiance mutuelle dans l'espace pénal européen (2005)

Detailed reference viewed: 45 (0 ULg)
Full Text
See detailProcessus de qualification du produit « viande bovine » veillant à valoriser les multiples fonctions de l’élevage
Stilmant, Didier; Stassart, Pierre M ULg; Jamar, Daniel

in Actes des Journées de Fourrage Actualité (2005)

Detailed reference viewed: 12 (0 ULg)
Full Text
See detailFrédéric Chaberlot, La Voie Lactée: histoire des conceptions et des modèles de notre Galaxie des temps anciens aux années 1930, Bibliographie critique
Nazé, Yaël ULg

in Archives Internationales d'Histoire des Sciences (2005), (154), 302-302

Detailed reference viewed: 25 (1 ULg)
Full Text
Peer Reviewed
See detailLa politique agricole commune et l'environnement : sont-ils compatibles ?
Burny, Philippe ULg

in Environment and Progress (2005), (5/2005), 51-58

This paper presents the successive regarding environment and included in the CAP. When the treaty establishing the European Economic Community was signed at Rome in 1957, a common policy was established ... [more ▼]

This paper presents the successive regarding environment and included in the CAP. When the treaty establishing the European Economic Community was signed at Rome in 1957, a common policy was established in the field of agriculture, and five objectives were defined. [less ▲]

Detailed reference viewed: 36 (4 ULg)
Full Text
Peer Reviewed
See detailThe accuracy of perceptual memory for personally known faces
Devue, Christel ULg; Brédart, Serge ULg

in Perception (2005), 34(Suppl. S), 166

Recently, Ge et al (2003 Perception 32 601 - 614) reported a very high accuracy of memory for a highly familiar face. Their Chinese participants had to identify the most veridical appearance of Mao's face ... [more ▼]

Recently, Ge et al (2003 Perception 32 601 - 614) reported a very high accuracy of memory for a highly familiar face. Their Chinese participants had to identify the most veridical appearance of Mao's face among unaltered and transformed (interocular distance was gradually increased or decreased) versions of his portrait. In the present experiment, the same facial transformations were applied to our participants' faces to evaluate whether this hyperfidelity for familiar faces is specific to famous individuals whose face is mainly known from a standard portrait, or if it could generalise to personally known faces (the own face and a close person's face). Results showed that performance was not different for the two familiar faces in the recognition task, or between the recognition task and a perceptual discrimination task. The high accuracy of memory previously shown for a very famous face generalises to personally known individuals for whom we have a varied visual experience. [less ▲]

Detailed reference viewed: 40 (15 ULg)
Full Text
See detailProcessus de qualification du produit « viande bovine » veillant à valoriser les multiples fonctions de l’élevage
Stilmant, Didier; Stassart, Pierre M ULg; Jamar, Daniel

in Actes des Journées de Fourrages Actualités (2005)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailThe accuracy of perceptual memory for personally known faces
Devue, Christel ULg; Brédart, Serge ULg

Poster (2005)

Recently, Ge et al. (2003) reported a very high accuracy of memory for a highly familiar face. Their Chinese participants had to identify the most veridical appearance of Mao’s face among unaltered and ... [more ▼]

Recently, Ge et al. (2003) reported a very high accuracy of memory for a highly familiar face. Their Chinese participants had to identify the most veridical appearance of Mao’s face among unaltered and transformed (inter-ocular distance was gradually increased or decreased) versions of his portrait. In the present experiment, the same facial transformations were applied to our participants’ faces to evaluate whether this hyperfidelity for familiar faces is specific to famous individuals whose face is mainly known from a standard portrait or if it could generalise to personally known faces (the own face and a close person’s face). Results showed that performance was not different for the two familiar faces in the recognition task, or between the recognition task and a perceptual discrimination task. The high accuracy of memory previously shown for a very famous face generalises to personally known individuals for whom we have a various visual experience. [less ▲]

Detailed reference viewed: 16 (5 ULg)
Full Text
Peer Reviewed
See detailInfluence of injection conditions on field tracer experiments
Brouyère, Serge ULg; Carabin, Guy; Dassargues, Alain ULg

in Ground Water (2005), 43(3), 389-400

Calibration of ground water transport models is often performed using results of field tracer experiments. However, little attention is usually paid to the influence, on resulting breakthrough curves, of ... [more ▼]

Calibration of ground water transport models is often performed using results of field tracer experiments. However, little attention is usually paid to the influence, on resulting breakthrough curves, of injection conditions and well-aquifer interactions, more particularly of the influence of the possible trapping of the tracer in the injection wellbore. Recently, a new mathematical and numerical approach has been developed to model injection conditions and well-aquifer interactions in a very accurate way. Using an analytical solution derived from this model, a detailed analysis is made of the evolution of the tracer input function in the aquifer. By varying injection conditions from one simulation to another, synthetic breakthrough curves are generated with the SUFT3D ground water flow and transport finite-element simulator. These tests show clearly that the shape of the breakthrough curves can be dramatically affected by injection conditions. Using generated breakthrough curves as "actual" field results, a calibration of hydrodispersive parameters is performed, neglecting the influence of injection conditions. This shows that neglecting the influence of actual injection conditions can lead to (1) errors on fitted parameters and (2) misleading identification of the active transport processes. Conclusions and guidelines are drawn in terms of proposed methodologies for better controlling the tracer injection in the field, in order to minimize risk of misinterpretation of results. [less ▲]

Detailed reference viewed: 44 (12 ULg)