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See detailA scalable heuristic for hybrid IGP/MPLS traffic engineering - Case study on an operational network
Skivée, Fabian; Balon, Simon ULg; Leduc, Guy ULg

in 14th IEEE International Conference on Networks (2006, September)

In current IP networks, a classical way to achieve traffic engineering is to optimise the link metrics. This operation cannot be done too often and can affect the route of a lot of traffic. Multiprotocol ... [more ▼]

In current IP networks, a classical way to achieve traffic engineering is to optimise the link metrics. This operation cannot be done too often and can affect the route of a lot of traffic. Multiprotocol Label Switching (MPLS) opens new possibilities to address the limitations of IP systems concerning traffic engineering thanks to explicit label-switched paths (LSPs). This paper proposes a new method based on simulated annealing meta-heuristic to compute a set of LSPs that optimise a given operational objective. The hybrid IGP/MPLS approach takes advantage of both IP and MPLS technologies and provides a flexible method to traffic engineer a network on a day to day basis. We illustrate the capabilities of our method with some simulations and a comparison with other techniques on an existing operational network. The results obtained by setting up a small number of LSPs are nearly optimal and better than by engineering the IGP weights. Moreover, although it could be combined with a static setting of the latter, SAMTE alone gives already the same results as this combination in much less CPU time, which thus allows an administrator to keep its initial and meaningful IGP metrics in his network. [less ▲]

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See detailDividing the Traffic Matrix to Approach Optimal Traffic Engineering
Balon, Simon ULg; Leduc, Guy ULg

in 14th IEEE International Conference on Networks (2006, September)

In this paper we propose a new method to approach optimal Traffic Engineering routing. The method consists of dividing the traffic matrix into $N$ sub-matrices, called strata, and route each of these ... [more ▼]

In this paper we propose a new method to approach optimal Traffic Engineering routing. The method consists of dividing the traffic matrix into $N$ sub-matrices, called strata, and route each of these independently. We propose two different implementations of our method in routers. Our method can also be used to compute a very precise approximation of the optimal value of a given objective function for comparison to heuristic Traffic Engineering algorithms. For this application, our algorithm is very efficient on large topologies compared to an LP formulation. [less ▲]

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See detailExperimental and simulation study of the Schottky barrier lowering by substrate doping variation for PtSi Source/Drain SBFETs
Lousberg, Grégory ULg; Yu, Hong-Yu; Froment, Benoit et al

in Proceedings of ESSDERC 2006 (2006, September)

In this paper, the authors study experimentally and numerically the Schottky barrier height (SBH) lowering of Pt silicide/n-Si diodes and its implications to Schottky-barrier (SB) source/drain p-FETs. The ... [more ▼]

In this paper, the authors study experimentally and numerically the Schottky barrier height (SBH) lowering of Pt silicide/n-Si diodes and its implications to Schottky-barrier (SB) source/drain p-FETs. The authors demonstrate that hole SBH can be lowered through an image-force mechanism by increasing the n-Si substrate doping, which leads to a substantial gain of the drive current in the long-channel bulk p-SBFETs. Numerical simulations show that the channel doping concentration is also critical for short-channel n- & p-SOI SBFETs performance [less ▲]

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See detailL'herpétofaune des bords de route en Wallonie: analyse de 101 stations
Graitson, Eric ULg

in Naturalistes Belges (Les) (2006), 87(3), 73-80

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See detailLa participation, composante du développement durable : quatre études de cas
Mormont, Marc ULg; Mougenot, Catherine ULg; Dasnoy, Christine ULg

in VertigO : la Revue Electronique en Sciences de l'Environnement (2006), 7(2),

Based on various case studies, this paper analyses public participation as a circulation process : collective action circulates controversial questions between various cognitive and normative spheres ... [more ▼]

Based on various case studies, this paper analyses public participation as a circulation process : collective action circulates controversial questions between various cognitive and normative spheres (local / global, policy / science). These moves allow to reorganise knowledges and to reformulate norms. Its efficiency depends on its capacity to constitute new collectives of environmental management. This perspective calls on an experimentalist mode of public policy. [less ▲]

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See detailUn discours sur le champ, l'historiographie littéraire : le problème de l'efficace des pratiques discursives
Provenzano, François ULg

in COnTEXTES : Revue de Sociologie de la Littérature (2006), 1

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See detailLe rôle du lien social dans le parcours des SDF : enseignements pour une politique publique
Italiano, Patrick ULg; Deflandre, Dimitri; Jacquemain, Marc ULg

Conference (2006, September)

The theory of social capital according to Putnam insists on the fact that social relations are useful recourses in different situations of life. But it does not fit acuretaly the description of the ... [more ▼]

The theory of social capital according to Putnam insists on the fact that social relations are useful recourses in different situations of life. But it does not fit acuretaly the description of the situation of homeless people who are not necessarily deprived of a social network but who become more demanding in their social relationships. They want to give and receive and not only to use people as recourses. A Maussian theory of social link through gift is probably more relevant than social capital theory to describe those phenomena. [less ▲]

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See detailApproximate Policy Iteration for Closed-Loop Learning of Visual Tasks
Jodogne, Sébastien ULg; Briquet, Cyril ULg; Piater, Justus ULg

in Lecture Notes in Computer Science (2006, September), 4212

Approximate Policy Iteration (API) is a reinforcement learning paradigm that is able to solve high- dimensional, continuous control problems. We propose to exploit API for the closed-loop learning of ... [more ▼]

Approximate Policy Iteration (API) is a reinforcement learning paradigm that is able to solve high- dimensional, continuous control problems. We propose to exploit API for the closed-loop learning of mappings from images to actions. This approach requires a family of function approximators that maps visual percepts to a real-valued function. For this purpose, we use Regression Extra-Trees, a fast, yet accurate and versatile machine learning algorithm. The inputs of the Extra-Trees consist of a set of visual features that digest the informative patterns in the visual signal. We also show how to parallelize the Extra-Tree learning process to further reduce the computational expense, which is often essential in visual tasks. Experimental results on real-world images are given that indicate that the combination of API with Extra-Trees is a promising framework for the interactive learning of visual tasks. [less ▲]

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See detailEVALUER AUTREMENT LA CAPACITE D’ANALYSER SA PRATIQUE D’ENSEIGNANT AU SECONDAIRE SUPERIEUR SOUS L’ANGLE DE LA PSYCHOLOGIE EDUCATIONNELLE
Delcomminette, Séverine ULg; Leclercq, Dieudonné ULg; Sente, Isabelle

in Actes du 19ème colloque de l’Association pour le Développement des Méthodologies d'Evaluation en Education (2006, September)

Le cours de psychologie éducationnelle à l’agrégation dispensé au sein de l’Université de Liège s’adresse à des futurs enseignants du secondaire supérieur. En novembre 2006, nous avons renversé notre ... [more ▼]

Le cours de psychologie éducationnelle à l’agrégation dispensé au sein de l’Université de Liège s’adresse à des futurs enseignants du secondaire supérieur. En novembre 2006, nous avons renversé notre processus traditionnel d’évaluation certificative pratiqué depuis 20 ans. Au lieu d’inviter les étudiants à répondre à des questions à choix multiple (QCM) sur des cas créés par nous sur base de nos seules représentations personnelles de la vie en classe, nous leur avons demandé de fournir des exemples dans leur domaine (chimie, langues germaniques, sciences sanitaires, … ; 20 domaines au total). Ce renversement de la perspective est comparable au passage du thème (traduire vers la langue étrangère) à la version (traduire vers sa langue). Dans cet article nous analysons l’aspect docimologique, formatif ainsi que l’intérêt perçu par les étudiants et par les encadrants de cette nouvelle formule d’évaluation. [less ▲]

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See detailA novel extended-spectrum TEM-type beta-lactamase, TEM-138, from Salmonella enterica serovar Infantis.
chouchani, chedli; Berlemont, Renaud ULg; masmoudi, A. et al

in Antimicrobial Agents and Chemotherapy (2006), 50(9), 3183-5

A novel natural TEM beta-lactamase with extended-spectrum activity, TEM-138, was identified in a ceftazidime-resistant clinical isolate of Salmonella enterica serovar Infantis. Compared to TEM-1, TEM-138 ... [more ▼]

A novel natural TEM beta-lactamase with extended-spectrum activity, TEM-138, was identified in a ceftazidime-resistant clinical isolate of Salmonella enterica serovar Infantis. Compared to TEM-1, TEM-138 contains the following mutations: E104K, N175I, and G238S. The bla(TEM-138) gene was located on a 50-kb transferable plasmid. Expression studies with Escherichia coli revealed efficient ceftazidimase and cefotaximase activities for TEM-138. [less ▲]

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See detailDual analysis for finite element solutions of plate bending
Debongnie, Jean-François ULg; Nguyen-Xuan, Hung; Cung, N. H.

in Topping, B. H. V.; Montero, G.; Montenegro, R. (Eds.) Proceedings of the Eighth International Conference on Computational Structures Technology (2006, September)

This paper presents the application of the dual analysis concept to plate bending. In this method, a same problem is analyzed parallely by a displacement and an equilibrium model. The energetic distance ... [more ▼]

This paper presents the application of the dual analysis concept to plate bending. In this method, a same problem is analyzed parallely by a displacement and an equilibrium model. The energetic distance between these two models is the sum of both global errors and consequently, an upper bound of each of them. After an exposition of the two models, numerical examples are presented, which illustrate the high obtainable accuracy of the method. [less ▲]

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See detailLes plantes transgéniques et la société
Mormont, Marc ULg; Goujon, Philippe

in Les OGM - Le cas des plantes transgéniques (2006)

Transgenic plants and GMO in general face resistance in the public sphere. These difficulteis do not aruise from irrationality. In order to understand them we have to accept the idea of a pluralism of ... [more ▼]

Transgenic plants and GMO in general face resistance in the public sphere. These difficulteis do not aruise from irrationality. In order to understand them we have to accept the idea of a pluralism of rationalities, this pluralism being in itself the source of technological innovations. [less ▲]

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See detailEtude de la population d’hippopotames (Hippopotamus amphibius L.) de la rivière Mouena Mouele au Parc National du Loango-Sud (Gabon)
Michez, Adrien ULg

Master's dissertation (2006)

Le Parc National du Loango ainsi que les 12 autres parcs nationaux gabonais créés en 2002 constituent une expérience sans précédent dans le domaine de la conservation en Afrique Centrale. La valorisation ... [more ▼]

Le Parc National du Loango ainsi que les 12 autres parcs nationaux gabonais créés en 2002 constituent une expérience sans précédent dans le domaine de la conservation en Afrique Centrale. La valorisation de ceux-ci, notamment scientifique, est une condition sine qua non à leur pérennisations dans le paysage gabonais. Le présent travail est le fruit de l’analyse d’une série de données récoltées sur l’hippopotame et son milieu au Parc National du Loango-Sud, plus particulièrement sur la population basée dans la rivière Mouena Mouele. Trois populations distinctes mais non-isolées ont été identifiées pour le sud du parc. Dans un rayon de 10 km autour d’un point fixé sur la rivière, une description des savanes a été réalisée, identifiant trois principaux types dominés respectivement par Axonopus compressus (Sw.) P.Beauv., Panicum congoense Franch. et Paspalum vaginatum Sw. Le régime alimentaire a été décrit via l’analyse d’échantillons de fèces comparés aux relevés phytosociologiques. Les principales espèces relevées dans les échantillons furent Paspalum vaginatum, Desmodium triflorum, Axonopus compressus et Stenotaphrum secundatum (Walt.) Kuntze. La fréquentation préférentielle par la population de certains types de savanes comme celle à Axonopus compressus a été également montré. Le statut de la population a été jugé en dessous d’un niveau de saturation, plusieurs facteurs limitant ont été identifiés telle une éventuelle pression anthropique combinée à une diminution de la ressource en saison sèche. Vu son rôle majeur dans l’écosystème, la conservation de l’hippopotame à Loango doit être considérée comme une priorité. [less ▲]

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See detailMix stability as a criterion for optimizing the granular composition to improve concrete durability – an application
Willem, Xavier; Courard, Luc ULg; Darimont, Anne ULg et al

in Marchand, J.; Bissonnette, B.; Gagné, R. (Eds.) et al Advances in Concrete through Science and Engineering (2006, September)

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See detailEncoding Difficulty Promotes Postlearning Changes in Sleep
Schmidt, Christina ULg; Peigneux, Philippe ULg; Muto, Vincenzo ULg et al

in Journal of Neuroscience (2006), 26(35), 8976-8982

Learning-dependent increases in sleep spindle density have been reported during nocturnal sleep immediately after the learning session. Here, we investigated experience-dependent changes in daytime sleep ... [more ▼]

Learning-dependent increases in sleep spindle density have been reported during nocturnal sleep immediately after the learning session. Here, we investigated experience-dependent changes in daytime sleep EEG activity after declarative learning of unrelated word pairs. At weekly intervals, 13 young male volunteers spent three 24 h sessions in the laboratory under carefully controlled homeostatic and circadian conditions. At approximately midday, subjects performed either one of two word-pair learning tasks or a matched nonlearning control task, in a counterbalanced order. The two learning lists differed in the level of concreteness of the words used, resulting in an easier and a more difficult associative encoding condition, as confirmed by performance at immediate cued recall. Subjects were then allowed to sleep for 4 h; afterward, delayed cued recall was tested. Compared with the control condition, sleep EEG spectral activity in the low spindle frequency range and the density of low-frequency sleep spindles (11.25–13.75 Hz) were both significantly increased in the left frontal cortex after the difficult but not after the easy encoding condition. Furthermore, we found positive correlations between theseEEG changes during sleep and changes in memory performance between pre nap and post-nap recall sessions. These results indicate that, like during nocturnal sleep, daytime sleep EEG oscillations including spindle activity are modified after declarative learning of word pairs. Furthermore, we demonstrate here that the nature of the learning material is a determinant factor for sleep-related alterations after declarative learning. [less ▲]

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See detailReconstruction of the 1979-2005 Greenland ice sheet surface mass balance using satellite data and the regional climate model MAR
Fettweis, Xavier ULg

Doctoral thesis (2006)

In order to improve our knowledge on the current state and variability of the Greenland ice sheet surface mass balance (SMB), a 27-year simulation (1979-2005) has been performed with the coupled ... [more ▼]

In order to improve our knowledge on the current state and variability of the Greenland ice sheet surface mass balance (SMB), a 27-year simulation (1979-2005) has been performed with the coupled atmosphere-snow regional model MAR. This simulation reveals an increase in the main factors of the SMB which are, on the one hand, the snowfall (+ 1.6 ± 1.8 km3 yr-1) in winter and on the other hand, the run-off (+ 4.2 ± 1.9 km3 yr-1) in summer. The net effect of these two competing factors leads to a SMB loss rate of – 2.7 ± 3.0 km3 yr-1, which has a significance of 87%. The melt extent derived from the passive microwave satellite data since 1979 also shows this trend. The melt water supply has increased because the Greenland ice sheet has been warming up by + 0.09 ± 0.04 °C yr-1 since 1979. This warming comes from a uniform increase of downward infra-red radiation which can not be explained by the natural variability. These changes result very likely from the global warming induced by human activities. As a result, it seems that: i) increased melting dominates over increased accumulation in a warming scenario, ii) the Greenland ice sheet has been significantly losing mass since the beginning of the 1980's by an increasing melt water run-off as well as by a probable increase of iceberg discharge into the ocean due to the "Zwally effect" (the melt water-induced ice sheet flow acceleration) and iii) the Greenland ice sheet is projected to continue to lose mass in the future. The Greenland ice sheet melting could have an effect on the stability of the thermohaline circulation (THC) and the global sea level rise. On the one hand, increases in the freshwater flux from the Greenland ice sheet (glacier discharge and run-off) could perturb the THC by reducing the density contrast driving it. On the other hand, the melting of the whole Greenland ice sheet would account for a global mean sea level rise of 7.4 m. [less ▲]

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See detailLa prescription médicamenteuse chez la personne âgée: que devons-nous savoir?
Wotquenne, Pol ULg; Petermans, Jean ULg; Scheen, André ULg

in Revue Médicale Suisse (2006), 2(76), 1878-801882-3

Because of the increasing longevity of the population, a growing number of very old people are exposed to medications. Drug therapy in this population is difficult because of our lack of knowledge. The ... [more ▼]

Because of the increasing longevity of the population, a growing number of very old people are exposed to medications. Drug therapy in this population is difficult because of our lack of knowledge. The number of drugs administered is generally high and the prescription is often inappropriate. Changes in body composition, malnutrition and renal failure can cause drug accumulation and toxicity. However, hepatic metabolism via cytochrome P450 does not seem to be markedly influenced by oldness. Iatrogenic pathology is frequent in the elderly and may lead to hospitalisation and reduction in quality of life. Specific education of the medical care team should be promoted in order to tackle this important problem of public health. [less ▲]

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See detailRegulation of vimentin by SIP1 in human epithelial breast tumor cells
Bindels, Sandrine ULg; Mestdagt, Mélanie ULg; Van de Walle, C. et al

in Oncogene (2006), 25(36), 4975-4985

The expression of Smad interacting protein-1 (SIP1; ZEB2) and the de novo expression of vimentin are frequently involved in epithelial-to-mesenchymal transitions (EMTs) under both normal and pathological ... [more ▼]

The expression of Smad interacting protein-1 (SIP1; ZEB2) and the de novo expression of vimentin are frequently involved in epithelial-to-mesenchymal transitions (EMTs) under both normal and pathological conditions. In the present study, we investigated the potential role of SIP1 in the regulation of vimentin during the EMT associated with breast tumor cell migration and invasion. Examining several breast tumor cell lines displaying various degrees of invasiveness, we found SIP1 and vimentin expression only in invasive cell lines. Also, using a model of cell migration with human mammary MCF10A cells, we showed that SIP1 is induced specifically in vimentin-positive migratory cells. Furthermore, transfection of SIP1 cDNA in MCF10A cells increased their vimentin expression both at the mRNA and protein levels and enhanced their migratory abilities in Boyden Chamber assays. Inversely, inhibition of SIP1 expression by RNAi strategies in BT-549 cells and MCF10A cells decreased vimentin expression. We also showed that SIP1 transfection did not activate the TOP-FLASH reporter system, suggesting that the beta-catenin/TCF pathway is not implicated in the regulation of vimentin by SIP1. Our results therefore implicate SIP1 in the regulation of vimentin observed in the EMT associated with breast tumor cell migration, a pathway that may contribute to the metastatic progression of breast cancer. [less ▲]

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See detailBulletin agrométéorologique - Juillet 2006
Tychon, Bernard ULg; Ozer, Pierre ULg; De Longueville, Florence ULg et al

in Bulletin agrométéorologique (2006), 5(4), 1-6

Le mois de juillet fut exceptionnellement chaud et sec jusqu’à la dernière semaine de juillet. Cette période sèche, dans la prolongation de celle du mois de juin, a pu entraîner des chutes de rendements ... [more ▼]

Le mois de juillet fut exceptionnellement chaud et sec jusqu’à la dernière semaine de juillet. Cette période sèche, dans la prolongation de celle du mois de juin, a pu entraîner des chutes de rendements de certaines cultures en phases sensibles en particulier là où la nature des sols n’a pas pu répondre aux besoins en eau des cultures. La situation des cultures reste cependant globalement favorable, laissant entrevoir des rendements généralement supérieurs à la moyenne des cinq années précédentes. [less ▲]

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