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See detailEtude diachronique, à l’aide de la télédétection, de l’évolution du littoral du sud du delta du Fleuve Rouge (Viet Nam)
de Marneffe, Geneviève; Thrinh, Phan Trong; Tan, Mai Thanh et al

in Bannari, Abderrazak; Blasco (Eds.) Les Xèmes Journées Scientifiques du Réseau Télédétection de l'AUF (2004, May 25)

Dans le cadre de la recherche partagée du réseau de télédétection qui réunit les laboratoires de télédétection de Liège et de Hanoï et dans le cadre des accords de coopération entre le Vietnam et la ... [more ▼]

Dans le cadre de la recherche partagée du réseau de télédétection qui réunit les laboratoires de télédétection de Liège et de Hanoï et dans le cadre des accords de coopération entre le Vietnam et la Région Wallonne (Belgique), l'étude de l'évolution du littoral du sud du delta du Fleuve Rouge a été réalisée. Cette étude comprend deux parties: la première consiste en une présentation générale du delta du Fleuve Rouge. Elle analyse surtout les différents facteurs qui influencent fortement la dynamique littorale (vents, houle, marées…). la deuxième partie est l'étude diachronique du littoral du sud du delta du Fleuve Rouge. Elle s'est effectuée en deux phases : d’abord le traitement et l'analyse de photos aériennes et d'images satellitales, ensuite un travail de vérité-terrain. [less ▲]

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See detailEtude dichronique et historique de l'évolution du trait de côte de la baie de Tanger (Maroc)
Ozer, André ULg; El Abdellaoui, Jamal Eddine ULg

in Télédétection  : Revue de Recherche et d'Application en Télédétection (2007), vol. 7(n° 1-2-3-4), 157-171

The diachronic analysis of air photos and Corona satellite images shows that the erosion of the sandy coast of Tangier bay occurred at variable speeds between 1972 and 1997. The period between 1972-1981 ... [more ▼]

The diachronic analysis of air photos and Corona satellite images shows that the erosion of the sandy coast of Tangier bay occurred at variable speeds between 1972 and 1997. The period between 1972-1981 shows generalized erosion with a rate of 4 m/year. The period of 1981-1997 registers a restoring of the average trend with the formation of three sectors, the first one in erosion with an average rate of 1,5 m/year, the second sector is stable and the third in accretion. Because of its remoteness from the production zones, the sandy beach evolves in a closed system. In fact, on the one hand, the construction of the harbour jetty intercepted the longshore drift generated by the west swell and, on the other hand, the development of the western hillside immobilized the sandy materials that do not contribute anymore to the current solid contribution. Finally, the longshore drift which redistributes the pebbles brought by the oued Halou is broken by the construction of a defence system. The fluvial discharges are henceforth immobilized between the breakwater and the eastern groyne and do not contribute to the sedimentary dynamics. This situation aggravates the impoverishment of the involved sedimentary stock. At present, the erosion that drew sediments of the beach from the most easterly beach to accrete that western portion can’t find more materials because of the erosion and of the quasitotal occupation of the beach. In fact, the western beach not nourished by sediments, will see its vulnerability increase gradually. The repairing of the beach further to successive storms is more difficult. This reality is already felt in 2006. On the other hand, a portion of the clayey coastal cliff of Tangier bay, considered as stable, sustains significant erosion. The mean rate of cliff retreat, recorded between 1981 and 1997, is estimated at 1,5m/year. The reconstructionof the natural coastal system and the monitoring of the successive developments in the bay show that the anthropization of the coast has unbalanced the system in an irreversible way. [less ▲]

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See detailEtude différentielle du développement opératoire
Beckers, Jacqueline ULg; Thirion, Anne-Marie ULg

in Recherches sur les handicaps socioculturels de 0 à 7-8 ans (1973)

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See detailL'étude du béton dans le cadre de la sécurité incendie
Gernay, Thomas ULg

Scientific conference (2014, March 14)

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See detailEtude du classement par forêts aléatoires d'échantillons perturbés à forte structure d'interaction
Brostaux, Yves ULg

Doctoral thesis (2005)

Amongst classification methods, forests of decision trees (Random Forests, BREIMAN, 2001) are highly versatile concerning descriptive attributes' or target variable's nature and shape of the concept to ... [more ▼]

Amongst classification methods, forests of decision trees (Random Forests, BREIMAN, 2001) are highly versatile concerning descriptive attributes' or target variable's nature and shape of the concept to estimate. Their diffusion in agronomical sciences is slowed by a lack of information about their ability to learn models with high interaction structures using learning samples with few examples and affected by random noise and irrelevant attributes. This research aim to fill this gap by a systematic exploration of those factors' effects and of the parameters of the Random Forests method, which is done by computer simulations, taking as a reference the classification trees generated by Breiman's CART method (1984). Results show that generating random forests with a partially deterministic attributes selection and a forest size of at least 100 or 500 trees give the best prediction accuracy. Those random forests show a significant increase in prediction accuracy on CART trees, even for low learning sample size (50 examples). This advantage reduce with the global perturbation level (noise and irrelevant attributes) but increase with the learning sample size, as random forests aren't affected by the asymptotic limitation of the learning curve showed by CART method. [less ▲]

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See detailEtude du colmatage dans un bioréacteur membranaire à recirculation externe utilisé en nitrification partielle
Kouakou, Edouard; Pirard, Jean-Paul ULg; Marchot, Pierre ULg et al

in Proceedings of MEMPRO 3 - Intégration des membranes dans les procédés (2006)

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See detailÉTUDE DU COMPLEXE ENZYMATIQUE DES SYMBIONTES DU TERMITE RETICULITERMES FLAVIPES (EX. SANTONENSIS)
Tarayre, Cédric ULg

Doctoral thesis (2014)

In the light of the economic, environmental and social context in which we live today, it has become obvious that the use of fossil fuels is not conceivable over the long term. Some alternatives have ... [more ▼]

In the light of the economic, environmental and social context in which we live today, it has become obvious that the use of fossil fuels is not conceivable over the long term. Some alternatives have therefore emerged in recent years. Second-generation biofuels are one of those alternatives and are based on the exploitation of vegetal biomass, also called lignocellulosic biomass. These materials require a hydrolysis step which can notably be achieved by enzymes. Some insects, such as termites, harbor complex microbial communities inside their digestive tracts. Those communities are able to produce enzymes which can be used in the field of the hydrolysis of vegetal biomass. This is what this thesis deals with. The main part of the work done focused on the research of enzyme-producing microorganisms (bacteria, mycetes and protists) responsible for the degradation of hemicelluloses and cellulose, the hydrolysis of which releases fermentable sugars. The insect which was used in this work was Reticulitermes flavipes (ex. santonensis), a lower termite, harboring a highly diversified internal microflora. This thesis describes the characterization of the microbial strains which were isolated and the enzymes they secrete. A complementary part of this research focussed on termites grown on artificial diets. The objective of this part was multiple : isolating enzyme-producing strains, not extractable according to the standard technique, and characterizing the microflora resulting from the applied artificial diets. This multidisciplinary approach was based on microscopy, proteomics, metagenomics and the assessment of metabolism applied to the different microbial consortia. [less ▲]

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See detailEtude du comportement aéroélastique des structures soumises à des écoulements décrochés
Andrianne, Thomas ULg; Dimitriadis, Grigorios ULg

Conference (2010, March 02)

L'objectif du travail de recherche est le développement d'un modèle numérique simulant les phénomènes aéroélastiques affectant les corps non-profilés, caractérisés par des effets de décrochage/raccrochage ... [more ▼]

L'objectif du travail de recherche est le développement d'un modèle numérique simulant les phénomènes aéroélastiques affectant les corps non-profilés, caractérisés par des effets de décrochage/raccrochage du fluide.L'application de ce modèle aux tabliers de point est prévue. [less ▲]

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See detailEtude du comportement au feu des structures mixtes acier-béton
Franssen, Jean-Marc ULg

Doctoral thesis (1987)

This Ph. D. thesis contains the basic therories at the base of the computer software CEFICOSS, the predecessor of the computer software SAFIR.

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See detailEtude du comportement d'un laser continu à colorant
Carapelle, Alain ULg

Master's dissertation (1996)

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See detailEtude du comportement d'une toiture de grandes dimensions soumise à un vent turbulent
Blaise, Nicolas ULg

Master's dissertation (2010)

The aim of this project is the development of a model allowing the calculation of the wind turbulence, using Matlab software. The problems associated wind tunnel pressure measurements (e.g. frequency ... [more ▼]

The aim of this project is the development of a model allowing the calculation of the wind turbulence, using Matlab software. The problems associated wind tunnel pressure measurements (e.g. frequency noise, noise) are taken into account. In order to solve the equation of motion, several methods are applied. First, modal superposition solving decoupled equations by Newmark (NK) and by Fourier transform (FT). Secondly, a stochastic analysis (SRSS and CQC) is performed, using white noise approximation (BB). As an ultimate goal of designing the structure, the calculation of extreme values is realized using a simplified method as well as the statistic method of extreme values. Results show that Newmark method, with fixed time step, produces an elongation of the period and is therefore not recommend. The modal correlation being low, the SRSS analysis is sufficient to determine the dynamic contribution. Results provided by the FT method are closer to the results obtain with CQC-BB method, thus these methods appear to be equivalent. Regarding the calculation of extreme values, the simplified method can calculate positive and negative peak factors, whereas the statistic method of extreme values, applied considering a Gaussian process, can't. In conclusion, the stochastic methods is recommanded because she had the advantage of treating appropriately the noise frequencies for the dynamic contribution. [less ▲]

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