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See detailMonitoring an odour in the environment with an electronic nose : requirements for the signal processing
Romain, Anne-Claude ULg; Delva, Julien ULg; Nicolas, Jacques ULg

Conference (2007, January)

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual measurement techniques of odour use human olfaction or conventional ... [more ▼]

Artificial olfaction system (the so-called electronic nose) is a very promising tool to monitor the malodour in the field. Usual measurement techniques of odour use human olfaction or conventional analytical techniques. The first category represents the real odour perception but is not applicable to measure continuously bad odours in the field. The second class of techniques gives the mixture composition but not the global information representative of the odour perception. The e-nose has the potentialities to combine "the odour perception" and the "monitoring in the field". However to be able to reach that goal, the signal processing has to be adapted to work in complex environment. The research group in Arlon has more than ten years experience in the measure of environmental malodours in the field. The paper presents the minimal requirements that the group considers as essential for artificial olfaction system to become successful for this application. [less ▲]

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See detailSufasalazine unveils a contact-independent HSV-TK/ganciclovir gene therapy bystander effect in malignant gliomas
Robe, Pierre ULg; Nguyen-Khac, Minh-Tuan ULg; Lambert, Frédéric ULg et al

in International Journal of Oncology (2007), 30(1), 283-290

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased ... [more ▼]

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased the HSV-TK/ganciclovir bystander effect in C6, 9L and LN18 cells but not in U87 glioma cells. Using bi-compartmental culture devices and conditioned medium transfer experiments, we showed that in C6, 9L and LN18 cells but not in U87 cells, Sulfasalazine also unveiled a new, contact-independent mechanism of HSV-TK/ganciclovir bystander effect. Upon treatment with ganciclovir, human LN18-TK but not U87-TK cells synthetized and released TNF-alpha in the culture medium. Sulfasalazine sensitized glioma cells to the toxic effect of TNF-alpha. and enhanced its secretion in LN18-TK cells in response to GCV treatment. The caspase-8 inhibitor Z-IETD-FMK and a blocking antibody to TNF-alpha both inhibited the contact-independent bystander effect in LN18 cells. Taken together, these results suggest that TNF-alpha mediates the contact-independent bystander effect in LN18 cells. The treatment with GCV and/or Sulfasalazine of tumor xenografts consisting of a mix of 98% C6 and 2% C6-TK cells shows that Sulfasalazine is also a potent adjunct to the in vivo treatment of gliomas. [less ▲]

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See detailMinimization of Production Cost by use of an Automatic Cost Assessment Method and Simulation
Caprace, Jean-David ULg; Bair, Frédéric ULg; Losseau, Nicolas ULg et al

in The Euro-Asia Maritime Network (EAMARNET) (2007, January)

This paper will present different ways to minimize cost in shipbuilding industry. Amongst them we have the production simulation methods, the cost assessment methods and the optimization methods. Nowadays ... [more ▼]

This paper will present different ways to minimize cost in shipbuilding industry. Amongst them we have the production simulation methods, the cost assessment methods and the optimization methods. Nowadays, cost assessment is a key task of an integrated ship design. The various methods to estimate the production cost differ with the known information (input data). The less information is detailed, the earlier a method can be used in the design process. The more information is used, the better we can assess the differences between design alternatives. The methods presented here and the “design for production” concept promise to increase the productivity trough the following points: a more accurate cost estimation, an improvement in the deadlines planning and the production schedule, a progress in distribution of the workload between the various production workshops, a better knowledge of the individual costs that will permit to reduce the global cost. In order to illustrate our work, we present in this paper three methods to decrease the global cost of a ship. [less ▲]

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See detailChanges in diatom, pollen, and chironomid assemblages in response to a recent volcanic event in Lake Galletue (Chilean Andes)
Urrutia, Roberto; Araneda, Alberto; Cruces, Fabiola et al

in Limnologica (2007), 37(1), 49-62

Several lakes in Chile are near important volcanic areas where eruption impacts can limit the quality of lacustrine sediments for reconstructing past environmental changes. In this study, we report ... [more ▼]

Several lakes in Chile are near important volcanic areas where eruption impacts can limit the quality of lacustrine sediments for reconstructing past environmental changes. In this study, we report changes in diatoms, pollen, and chironomids assemblages after a tephra deposition in Lake Galletue (Chilean Andes). A sediment core obtained from Lake Galletue (40 m water depth) was sliced in I cm intervals and subsamples were taken to analyze each proxy. Pb-210 and 137 Cs activities were measured to obtain the geochronology and mineralogical analyses were performed to determine the mineral composition of the tephra. Diatom species composition and productivity were modified when the lake received the tephra; Aulacoseira granulata decreased and was later replaced by Cyclotella af. glomerata. After the tephra input, Aulacoseira granulata abundance increased to pre-disturbance levels and Cyclotella af. glomerata decreased. These changes seem to suggest a momentary increase in lake nutrient levels after the tephra deposition. Chironomid assemblages also decreased in head capsules just after the tephra deposition, but the most important change was the replacement of Ablabesmyia by Parakiefferiella, probably due to the sedimentological changes produced by the input of coarse tephra grains. Furthermore, unlike other studies, chironomid assemblages in Lake Galletue did not show a decrease drastically in diversity within the tephra layer. The pollen analysis indicated that, prior to the volcanic event, the vegetal community was dominated by Nothofagus sp., Araucaria araucana, and Blechnum sp.-type. After the tephra deposition, the same taxa are dominant, indicating that the volcanic event seems not produce changes in the vegetation. Nevertheless, within the tephra layer it is possible to see an increase in Poaceae, which represent - due to the percolation process - the effect of eruption on the vegetation. According to our results, diatoms were the most sensitive proxy for describing the changes produced by tephra deposition into the aquatic ecosystem and, despite the noticeable changes in its sedimentological properties; the lake seems to have a high resilience capacity, allowing it to return to pre-tephra input conditions. (c) 2006 Elsevier GmbH. All rights reserved. [less ▲]

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See detailEstimation of air quality degradation due to Saharan dust at Nouakchott, Mauritania, from horizontal visibility data
Ozer, Pierre ULg; Laghdaf, MBOM; Lemine, S. O. M. et al

in Water, Air & Soil Pollution (2007), 178(1-4), 79-87

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) and respiratory particulates or Particulate Matter less than 10 mu m in aerodynamic diameter (PM10 ... [more ▼]

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) and respiratory particulates or Particulate Matter less than 10 mu m in aerodynamic diameter (PM10) has numerous undesired consequences on human health. Air quality degradation far from the African continent, in the US and in Europe, caused by high concentrations of African dust, is seen as a major threat even though most of these countries are very distant from the Sahara. Surprisingly, no estimates of TSP or PM10 levels near the Saharan dust source are available. Based on horizontal visibility observations which are reduced by the presence of dust in the atmosphere, TSP and PM10 levels are estimated throughout the year 2000 at Nouakchott-Airport, Mauritania, using relations found in the literature. It appears that concentrations of particles are significant both in terms magnitude and frequency, as the 24-hour PM10 thresholds established by the US EPA National Ambient Air Quality Standards and the EU Limits Values for Air Quality were exceeded 86 and 137 times, respectively. The average annual concentration is far above air quality standards and estimated at 159 mu g m(-3) for TSP and 108 mu g m(-3) for PM10. These very high particulate levels are likely to represent an important public health hazard and should be considered as a major environmental risk. [less ▲]

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See detailMapping the updating process: common and specific brain activations across different versions of the running span task
Collette, Fabienne ULg; Van der Linden, Martial ULg; Laureys, Steven ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2007), 43(1), 146-158

Neuroimaging studies exploring the neural substrates of executive functioning have only rarely investigated whether the non-executive characteristics of the experimental executive tasks could contribute ... [more ▼]

Neuroimaging studies exploring the neural substrates of executive functioning have only rarely investigated whether the non-executive characteristics of the experimental executive tasks could contribute to the observed brain activations. The aim of this study was to determine cerebral activity in three different tasks involving the updating executive function. The experimental updating tasks required subjects to process strings of items (respectively letters, words, and sounds) of unknown lengths, and then to recall or identify a specific number of presented items. Conjunction and functional connectivity analyses demonstrated that the cerebral areas activated by all three experimental tasks are the left frontopolar cortex, bilateral dorsolateral prefrontal and premotor cortex, bilateral intraparietal sulcus, right inferior parietal lobule and cerebellum. Some regions of this network appear to be more specific to each updating task. These results clearly indicate that the neural substrates underlying a specific executive process (in this case, updating) are modulated by the exact requirements of the task (such as the material to process or the kind of response) and the specific cognitive processes associated with updating. [less ▲]

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See detailGuide de rédaction du TFE en médecine générale
Vanmeerbeek, Marc ULg

Learning material (2007)

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See detailSpatial coherence measurements in arrays of coupled vertical cavity surface emitting lasers
Lundeberg, Lars; Lousberg, Grégory ULg; Boiko, Dmitri et al

in Applied Physics Letters (2007), 90

The spatial coherence and the optical phase distribution across a two-dimensional 2D photonic crystal implemented with coupled arrays of vertical cavity surface emitting lasers VCSELs are experimentally ... [more ▼]

The spatial coherence and the optical phase distribution across a two-dimensional 2D photonic crystal implemented with coupled arrays of vertical cavity surface emitting lasers VCSELs are experimentally characterized. This is achieved by performing Young’s interference experiments between pairs of array elements using a spatial light modulator arrangement. In contrast to far-field measurements that provide information only on the global spatial coherence, this approach can yield full mapping of the complex degree of spatial coherence. Examples of such analysis are presented for nominally uniform one-dimensional and 2D arrays of coupled VCSELs and possible mechanisms of the observed coherence degradation are discussed. [less ▲]

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See detailCollective motion, sensor networks, and ocean sampling
Leonard, Naomi Ehrich; Paley, Derek; Lekien, François et al

in Proceedings of the IEEE (2007), 95(1), 48-74

This paper addresses the design of mobile sensor networks for optimal data collection. The development is strongly motivated by the application to adaptive ocean sampling for an autonomous ocean observing ... [more ▼]

This paper addresses the design of mobile sensor networks for optimal data collection. The development is strongly motivated by the application to adaptive ocean sampling for an autonomous ocean observing and prediction system. A performance metric, used to derive optimal paths for the network of mobile sensors, defines the optimal data set as one which minimizes error in a model estimate of the sampled field. Feedback control laws are presented that stably coordinate sensors on structured tracks that have been optimized over a minimal set of parameters. Optimal, closed-loop solutions are computed in a number of low-dimensional cases to illustrate the methodology. Robustness of the performance to the influence of a steady flow field on relatively slow-moving mobile sensors is also explored. [less ▲]

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See detailRenouveler la rapport du travail à la nature
Mormont, Marc ULg

in Revue Nouvelle (2007), (1-2), 46-49

Depuis un siècle et demi, la modernisation du monde rural, marquée par une rationalisation croissante, s’est faite au détriment de la gestion en commun. La bureaucratisation du vivant transforme les ... [more ▼]

Depuis un siècle et demi, la modernisation du monde rural, marquée par une rationalisation croissante, s’est faite au détriment de la gestion en commun. La bureaucratisation du vivant transforme les agriculteurs d’artisans en techniciens. À condition de mener une réflexion sur le travail et la nature, l’économie sociale peut apporter un projet à un monde rural qui associerait marché, consommation et action publique [less ▲]

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See detailMultidrug resistance gene-1 polymorphisms and resistance to cyclosporine a in patients with steroid resistant ulcerative colitis
Daniel, F.; Loriot, M. A.; Seksik, P. et al

in Inflammatory Bowel Diseases (2007), 13(1), 19-23

Background: Cyclosporine A (CsA) is inconstantly effective in inducing remission in acute attacks of ulcerative colitis (UC) not responding to steroids. This study aimed to establish whether multidrug ... [more ▼]

Background: Cyclosporine A (CsA) is inconstantly effective in inducing remission in acute attacks of ulcerative colitis (UC) not responding to steroids. This study aimed to establish whether multidrug resistance gene (MDR)1 polymorphisms would be associated with CsA failure. Patients and Methods: The distribution of the different genotypes of single nucleotide polymorphisms (SNP) G2677T/A and C3435T of MDR1 exons 21 and 26, respectively, was studied in 154 patients (mean age, 44 yr) who had received CsA to treat severe attacks of steroid resistant UC in 11 centers in France and Belgium. Patients were classified as CsA failure (n = 50) when they needed colectomy within 30 days after CsA initiation. The SNPs were detected by use of a 5' nuclease allelic discrimination assay. Results: There was a significant association between the G2677T/A polymorphism distribution (exon 21) and the risk for CsA failure (P = 0.0001). The TT genotype of exon 21 was significantly associated with the risk compared with the two other genotypes (odds ratio, 3.77; 95% confidence interval, 1.42-9.97, P = 0.007). There was no significant association between the genotype C3435T distribution (exon 26) and the risk of CsA failure (P = 0.23). Conclusion: The TT genotype of exon 21 MDR1 polymorphisms is associated with a higher risk of CsA failure in patients with steroid resistant UC. Further studies should be performed to establish whether other treatments could be more efficient to avoid surgery in this subset of patients. [less ▲]

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See detailPlanification stratégique de Systèmes de transport de marchandises en Europe : Modèles de localisations optimales de hubs de conteneurs sur un réseau multimodal
Limbourg, Sabine ULg

Doctoral thesis (2007)

There is a growing imbalance between modes of transport in the European Union. The increasing success of road results in an ever worsening congestion, more environmental nuisances and accidents. That’s ... [more ▼]

There is a growing imbalance between modes of transport in the European Union. The increasing success of road results in an ever worsening congestion, more environmental nuisances and accidents. That’s why one of the objectives of the European Common Transport Policy is to restore the balance between modes of transport and to develop intermodality. Among the various types of intermodal transport this doctoral dissertation is concerned by rail-road combined transport for which the terminals are embedded in a hub-and-spoke network. This kind of topology can reduce the transportation costs by consolidations at the hubs. The proposed method uses the flows of commodities and their geographic spreading as input to determine a set of good potential locations for transfer container terminals. This set can further be used as input for an iterative procedure based on both the p-HMP and the multi-modal assignment in order to identify the optimal locations for such terminals in Europe. This procedure takes into account the variation of the transshipment cost according to the number of containers that could be transshipped. [less ▲]

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See detailInter-modal freight terminal location in Europe : a strategic model
Jourquin, Bart; Limbourg, Sabine ULg

in Proceedings of the BIVEC-GIBET, Transport Research Day 2007 (2007)

The political pressure in favour of multi- and inter-modal transport has oriented the focus on sustainable transport solutions. Inter-modal transport is one of the possible solutions, but its efficiency ... [more ▼]

The political pressure in favour of multi- and inter-modal transport has oriented the focus on sustainable transport solutions. Inter-modal transport is one of the possible solutions, but its efficiency strongly depends on the places where the container terminals are located. The number of possible locations on large scale networks becomes rapidly too large to be taken as input by exact location methods. That’s why the first goal of this paper is to outline a method that helps to identify the best potential locations out of the thousands of potential nodes. The basic idea is to use the flows of commodities and their geographic spreading as input to determine a set of good potential locations for transfer inter-modal terminals. This set can, in a second step, be used as input for already well known optimal location models in order to identify the optimal locations for container terminals in Europe. The methodology is illustrated over the whole trans-European networks. The paper concludes with a discussion of the results: the model predicts a reduction of the total transportation costs on the network and a modal shift from road to rail. It also evaluates the new modal shift and other indicators [less ▲]

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See detailAnalyse inverse en géotechnique : développement d’une méthode à base d’algorithmes génétiques
Levasseur, Séverine ULg

Doctoral thesis (2007)

La plupart des essais géotechniques in situ ne permettent pas d’identifier directement les paramètres constitutifs des couches de sol. L’utilisation de calculs par éléments finis pour dimensionner les ... [more ▼]

La plupart des essais géotechniques in situ ne permettent pas d’identifier directement les paramètres constitutifs des couches de sol. L’utilisation de calculs par éléments finis pour dimensionner les ouvrages est ainsi limitée par une mauvaise connaissance des propriétés mécaniques des sols. C’est dans ce contexte que se pose la problématique d’analyse inverse en géotechnique : quelles informations concernant les paramètres constitutifs du sol est-il possible d’obtenir à partir de mesures in situ? Ce travail concerne l’identification des paramètres de modèles constitutifs de sols par analyse inverse. Afin d’avoir une méthode d’identification adaptable à tout type de mesures (essais in situ ou ouvrages instrumentés), une méthode directe de résolution du problème inverse est développée. Des valeurs a priori sont données aux paramètres inconnus pour simuler le problème direct associé, à l’aide du code de calcul par éléments finis jusqu’à ce que l’écart entre les résultats du calcul numérique et les mesures in situ soit minimal. Les principales approches utilisées dans la littérature pour résoudre des problèmes d’optimisa- tion sont basées sur des méthodes de gradient. Ces méthodes supposent l’unicité de la solution du problème inverse. Or, les erreurs de modélisation et les incertitudes de mesures sont importantes en géotechnique. Il n’existe donc pas de solution exacte pour le problème inverse mais plutôt une infinité de solutions approchées. L’objectif de ce travail est de développer une méthode d’analyse inverse permettant d’identifier l’ensemble de ces solutions. Pour cela, nous avons choisi de baser la procédure d’analyse inverse sur un processus d’optimisation par algorithme génétique. Cette méthode, robuste et efficace, est connue pour sa capacité à résoudre des problèmes complexes. Nous montrons dans cette étude que l’analyse des solutions estimées par l’algorithme informe également sur la sensibilité des paramètres d’un modèle et sur l’existence possible de relations mathématiques entre ces paramètres. Suite à cela, nous proposons de décrire mathématiquement l’ensemble des solutions identifiées par l’algorithme génétique grâce à une étude statistique de type analyse en composantes principales. Cette étude montre que même si toutes les solutions d’un problème ne sont pas identifiées directement par l’algorithme génétique, leur exploitation par une analyse en composantes principales permet d’estimer l’ensemble des solutions du problème inverse. Cette méthode est développée à partir de quelques résultats obtenus sur des exemples synthétiques d’ouvrages de soutènement et d’essais pressiométriques. Puis, différentes applications réelles sur ces types d’essais et d’ouvrages géotechniques illustrent la pertinence de la méthode. [less ▲]

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See detailCompte-rendu du colloque Européen « Trisomie en mouvement »
Frenkel, Stéphanie ULg

in Nouvelles du chromosome 21 (2007), 16

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See detailMîmâmsâ-and Vedânta-sentences in Padmapâda's Pañcapâdikâ (Chapter 2)
Verpoorten, Jean-Marie ULg

in Bronkhorst, Johannes (Ed.) Mîmâmsâ and Vedânta. Interaction and Continuity (2007)

Au chapitre 2 de sa Pañcapādikā, Padmapāda (9e s.) présente un débat entre un mīmāṃsaka et un vedāntin qui argumentent à propos l’élaboration d’une néo-mīmāṃsā, laquelle commenterait des phrases des ... [more ▼]

Au chapitre 2 de sa Pañcapādikā, Padmapāda (9e s.) présente un débat entre un mīmāṃsaka et un vedāntin qui argumentent à propos l’élaboration d’une néo-mīmāṃsā, laquelle commenterait des phrases des Upaniṣad’s à contenus mystiques ou eschatologiques et non plus rituels. Problème n°1 Le mīmāṃsaka estime que sa doctrine n’a nul besoin d’un complément qui proviendrait de matériaux relevant du Vedānta . Que faire alors de ces phrases aux allures injonctives que le Vedāntin voudrait faire figurer aux côtés de ces injonctions rituelles chères à son collègue ritualiste. Ne peut-on pas traiter la connaissance de l’ātman comme une sorte de rite « à faire » (kārya) par un « ayant droit » (adhikārin) ? Aux yeux du Vedāntin, l’ātman défini comme essence de la réalité et totalité universelle est un objet à méditer. A quoi l’adversaire mīmāṃsaka répond que l’ātman ainsi conçu est soit inconnaissable soit, au contraire, déjà connu (siddha) avant tout investigation. Le vedāntin propose par exemple de compléter Bṛhadāraņyaka-upaniṣad 4 5 7, c’est à dire les mots idaṃ sarvaṃ yad ayam ātmā « l’ātman hic et nunc c’est l’univers tout entier » à l’aide de l’obligatif jñātavyaḥ, car ces mots révèlent quelque chose d’inédit et sont donc à cataloguer comme injonction. Le mīmāṃsaka en revanche tient pour inadéquat de donner un statut d’injonction à un texte qui concerne l’ātman, c’est-à-dire une entité invisible et donc inconnaissable. Selon lui, mieux vaut voir dans l’ātman l’ego individuel et laisser chacun le méditer sans injonction. Problème n°2 Pourquoi Ms 1 1 1 contient-il le mot dharma et non vedārtha ? parce que –répond le Vedāntin- Jaimini veut montrer que le « devoir » s’étend au-delà du strict « sens du Véda » pris comme synonyme d’activité rituelle.L’accès au bonheur n’est pas garanti rien que par celle-ci et peut inclure la méditation upanishadique sur l’essence de la réalité De même en Ms 1 1 2, le mot codanā « injonction » ne renvoie pas exclusivement à l’action rituelle, comme le voudrait le M. Il peut être une invitation à dépasser le rite vers une investigation plus large . Autre manière de dire qu’une uttaramīmāṃsā , une enquête ultérieure, s’ouvre et c’est le Vedānta. [less ▲]

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See detailTHE DIOXIN FUNCTION AS A USEFUL TOOL FOR ASSESSING DIOXIN LABORATORY PERFORMANCES IN PROFICIENCY TESTS
Eppe, Gauthier ULg; Van Cleuvenbergen, Rudy; Smastuen Haug, Line et al

in Organohalogen Compounds (2007)

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See detailUrban Ontologies for an improved communication in urban civil engineering projects
Teller, Jacques ULg; Keita, Abdelkader; Roussey, Catherine et al

in Cybergeo : Revue Européenne de Géographie = Cybergeo - European Journal of Geography (2007)

In this paper, we presented the Towntology project whose objective is to design an ontology in the urban field. This project is divided into several stages. Concerning the prime main objective of the ... [more ▼]

In this paper, we presented the Towntology project whose objective is to design an ontology in the urban field. This project is divided into several stages. Concerning the prime main objective of the Towntology project, i.e. to build an ontology for urban planning by integrating all urban objects with their descriptions and relations, we began to deal with some fields, such as street planning and mobility. We also developed a software tool making it possible to urban planners to work on a semantic network. Thus we built a visual browser and an ontology editor. An extension of XML is designed and used for the description of the ontology. [less ▲]

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