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See detailAutomatic time stepping algorithms for implicit numerical simulations of blade/casing interactions
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in International Journal of Crashworthiness (2001), 6(3), 351-362

An automatic time stepping algorithm for non-linear problems, solved by implicit schemes, is presented. The time step computation is based on the estimation of an integration error calculated from the ... [more ▼]

An automatic time stepping algorithm for non-linear problems, solved by implicit schemes, is presented. The time step computation is based on the estimation of an integration error calculated from the acceleration difference. It is normalised according to the size of the problem and the integration parameters. This time step control algorithm modifies the time step size only if the problem has a long time physical change. Additionally, the Hessian matrix can be kept constant for several iterations, even though the problem is non-linear. A criterion selecting if the Hessian matrix must be calculated or not is developed. Finally, a criterion of iterations divergence is also proposed. It avoids the determination, by the user, of a maximal iteration number. This minimises the total number of iterations, and thus the computation cost. Industrial numerical examples are presented that demonstrate the performances (precision and computational cost) of the algorithms. [less ▲]

Detailed reference viewed: 48 (4 ULg)
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See detailAutomatic time stepping algorithms for implicit numerical simulations of non-linear dynamics
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in Advances in Engineering Software (2002), 33(7-10, JUL-OCT), 589-603

When an implicit integration scheme is used, variable step strategies are especially well suited to deal with problems characterized by high non-linearities. Constant step size strategies generally lead ... [more ▼]

When an implicit integration scheme is used, variable step strategies are especially well suited to deal with problems characterized by high non-linearities. Constant step size strategies generally lead to divergence or extremely costly computations. An automatic time stepping algorithm is proposed that is based on estimators of the integration error of the differential dynamic balance equations. Additionally, the proposed algorithm automatically takes decisions regarding the necessity of updating the tangent matrix or stopping the iterations, further reducing the computational cost. As an illustration of the capabilities of this algorithm, several numerical simulations of both academic and industrial problems are presented. (C) 2002 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 37 (7 ULg)
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See detailAutomatic time stepping algorithms for implicit numerical simulations of non-linear dynamics
Noels, Ludovic ULg; Stainier, Laurent ULg; Ponthot, Jean-Philippe ULg et al

in Topping, B. H. V.; Motas Soares, C. A. (Eds.) FINITE ELEMENTS: TECHNIQUES AND DEVELOPMENTS (2000)

Variable step strategies are specially well suited to deal with problems characterized by high non-linearity and contact/impact. Both phenomena are typical of dynamic simulations of the interactions ... [more ▼]

Variable step strategies are specially well suited to deal with problems characterized by high non-linearity and contact/impact. Both phenomena are typical of dynamic simulations of the interactions between a turbine blade and its casing, the most dramatic example being blade loss. Constant step size strategies do not give satisfactory answer for this kind of problems, since it is very difficult, if not impossible, for the user to find an appropriate time step that does not lead to divergence nor generate extremely costly computations. An automatic time stepping algorithm is proposed, which takes into account the recent history of accelerations in the bodies under consideration. More precisely, the adaptation algorithm is based on estimators of the integration error of the differential dynamic balance equations. This allows for adaptation of the time step to capture correctly the transient phenomena, with characteristic times which can range from relatively long (in regime) to very short (blade loss), thus ensuring precision while keeping the computation cost to a minimum. Additionally, the proposed algorithm automatically takes decisions regarding the necessity of updating the tangent matrix or stopping the iterations, further reducing the computational cost. As an illustration of the capabilities of this algorithm, several numerical simulations of both academic and industrial (the contact/impact between a turbine blade and the casing) problems will be presented. [less ▲]

Detailed reference viewed: 43 (5 ULg)
Peer Reviewed
See detailAutomatic X-ray fluorescence scanning mobile system for 2D chemical analysis
Strivay, David ULg; Hocquet, François-Philippe; Dister, Hervé et al

Conference (2012, December)

Detailed reference viewed: 32 (3 ULg)
See detailAutomatiisation: actualité et perspectives
MELIN, Pierrette ULg

Scientific conference (1996, March)

Detailed reference viewed: 3 (0 ULg)
See detailAutomation en microbiologie: Actualité et perspectives
MELIN, Pierrette ULg

Conference (1996, June 05)

Detailed reference viewed: 12 (1 ULg)
See detailAutomation for the Measurement of Selected PBDEs in Human Serum
Focant, Jean-François ULg

Scientific conference (2011, August)

Detailed reference viewed: 5 (2 ULg)
See detailAutomation in Identification and Susceptibility Testing
Melin, Pierrette ULg; De Mol, Patrick ULg

Conference (2001, June 14)

Detailed reference viewed: 10 (1 ULg)
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See detailAutomatisation d'un banc de répartition pour buses de pulvérisation
Lebeau, Frédéric ULg; Hamza, Elies; Destain, Marie-France ULg

in Cahiers Agricultures (2000)

Les bancs de répartition constituent l'élement de base permettant de tester la sensibilité de la distribution transversale des buses de pulvérisation aux différents paramètres de fonctionnement. L'article ... [more ▼]

Les bancs de répartition constituent l'élement de base permettant de tester la sensibilité de la distribution transversale des buses de pulvérisation aux différents paramètres de fonctionnement. L'article présente un banc d'essai conforme à la norme ISO 5682/1 qui permet une lecture automatisée des différentes grandeurs (pression, débit, volume recueilli). [less ▲]

Detailed reference viewed: 101 (25 ULg)
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See detailL'automatisation dans l'agriculture et dans l'industrie agro-alimentaire. Un exemple : le tri des fruits en fonction de leurs caractéristiques externes
Leemans, Vincent ULg; Destain, Marie-France ULg

Scientific conference (1997, May 15)

Séminaire de vulgarisation sur l'utilisation des techniques d'analyse d'image pour l'évaluation de la forme de fruit et pour la recherche de défauts.

Detailed reference viewed: 89 (6 ULg)
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See detailL'automatisation de la Bibliothèque générale de l’Université de Liège
Denooz, Joseph ULg

in Archives et Bibliothèques de Belgique = Archief en Bibliotheekwezen in Belgie (1971), Numéro spécial 6

Detailed reference viewed: 54 (23 ULg)
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See detailAUTOMATISATION DE LA DÉTECTION DES CRATÈRES LUNAIRES SUR DES IMAGES ET MNT PLANÉTAIRES
Renson, Pierre; Poncelet, Nadia; Vandeloise, Yannick et al

in Bulletin de la Société Géographique de Liège (2014), 61

This research is part of the preparation of a lunar mission. Its objective is to implement, test and validate an automated method that detects craters on the lunar surface from planetary products (images ... [more ▼]

This research is part of the preparation of a lunar mission. Its objective is to implement, test and validate an automated method that detects craters on the lunar surface from planetary products (images and DTM). In this context, the automation of the process is essential because the craters represent a landing risk and landmarks for visual navigation. It is also the key challenge because it is difficult to develop high level automatic processing comparable to the thinking carried out in a traditional visual interpretation. Our method automatically establishes a semantic diagnosis based on the combination of crater descriptors computed on the planetary products used. Finally, this application is part of a decision support tool and an assessment system of landing and mission survival risks. It also aims to feed a landmarks database for automatic visual navigation of a lunar landing spacecraft. [less ▲]

Detailed reference viewed: 19 (1 ULg)
See detailAutomatisation en bactériologie: hier, aujourd'hui et demain
MELIN, Pierrette ULg

Scientific conference (2011, April 28)

Detailed reference viewed: 85 (5 ULg)
See detailAutomatisation en microbiologie
MELIN, Pierrette ULg

Scientific conference (1996, May)

Detailed reference viewed: 30 (2 ULg)
See detailAutomatisation in blood cultures
Melin, Pierrette ULg; De Mol, Patrick ULg

Conference (2001, June 14)

Detailed reference viewed: 9 (2 ULg)
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See detailAutomatisme
Bertrand, Jean-Pierre ULg; Claisse, Frédéric ULg

in Aron, Paul; Saint-Jacques, Denis; Viala, Alain (Eds.) Le Dictionnaire du Littéraire (2002)

Detailed reference viewed: 40 (8 ULg)
Peer Reviewed
See detailAutomatization of mirror - tracing skill in children with Developmental Coordination Disorder
Lejeune, Caroline ULg; Meulemans, Thierry ULg; Desmottes, Lise ULg et al

Poster (2014, September)

Aim: This study investigated the hypothesis of a skill automatization deficit in Developmental Coordination Disorder (DCD). Method: Thirty children (15 with DCD and 15 control children), aged between 7 ... [more ▼]

Aim: This study investigated the hypothesis of a skill automatization deficit in Developmental Coordination Disorder (DCD). Method: Thirty children (15 with DCD and 15 control children), aged between 7 and 12 years old, were administered the mirror-tracing task during two 10-trials sessions separated by one week. An auditory interference task was introduced at the end of the procedural learning phase to test skill automatization. Results: Interestingly, no between-group difference was revealed in learning and automatization measures except for a specific subgroup of DCD children (n=5) who experienced difficulties in skill automatization. Conclusion: The results of our preliminary study highlighted the heterogeneity of the deficit presented in DCD and they emphasized the importance to explore further the lack of automatization in DCD. [less ▲]

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See detailAutomédication des céphalées fréquentes : étude dans les officines belges.
Mehuys, Els; Paemeleire, Koen; Van Hees, Thierry ULg et al

in Journal de Pharmacie de Belgique (2012), 2

AIM: This observational community pharmacy-based study aimed to investigate headache characteristics and medication use of persons with regular headache presenting for self-medication. METHODS ... [more ▼]

AIM: This observational community pharmacy-based study aimed to investigate headache characteristics and medication use of persons with regular headache presenting for self-medication. METHODS: Participants (n=1205) completed ii) a questionnaire to assess current headache medication and previous physician diagnosis, (ii) the ID Migraine Screener [ID-M] and (iii) the MIDAS questionnaire. RESULTS: Forty-four % of the study population (n=528) did not have a physician diagnosis of their headache, and 225 of them (225/528, 42.6%) were found to be ID-M positive. The most commonly used acute headache drugs were paracetamol (used by 62% of the study population), NSAIDs (39%) and combination analgesics (36%). Only 12% of patients physician-diagnosed with migraine used prophylactic migraine medication, and 25% used triptans. About 24% of our sample (n=292) chronically overused acute medication, which was combination analgesic overuse (n=166), simple analgesic overuse (n=130), triptan overuse (n=19), ergot overuse (n=6) and opioid overuse (n=51). Only 14.5% was ever advised to limit intake frequency of acute headache treatments. CONCLUSIONS: This study identified underdiagnosis of migraine, low use of migraine prophylaxis and triptans, and high prevalence of medication overuse among subjects seeking self-medication for regular headache. Community pharmacists have a strategic position in education and referral of these self-medicating headache patients. [less ▲]

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See detailAutomédication par les antibiotiques provenant des pharmacies privées de la ville d’Abidjan en Côte d’Ivoire
Hounsa, Anita; Kouadio, L.; De Mol, Patrick ULg

in Médecine et Maladies Infectieuses (2010), 40(6), 333-340

Abstract Self-medication with antibiotics is all the more disturbing in developing countries where this type of medication is easily available, and often without any prescription. Objectives. – The ... [more ▼]

Abstract Self-medication with antibiotics is all the more disturbing in developing countries where this type of medication is easily available, and often without any prescription. Objectives. – The authors wanted to assess and describe self-medication with antibiotics and identify the factors and public perception associated with this type of self-medication. Patients and methods. – Eighteen private pharmacies were randomly selected in Abidjan. Data was collected through structured questionnaires and reports. Group meetings were organized for private pharmacy clients and the pharmacy staff.Results. – Two hundred and forty-two out of 1,123 purchases of antibiotics were for self-medication (21.5 %). Out of the 1,765 people interviewed, 1,054 (59.7 %) had bought antibiotics for self-medication in the 12 months prior to our study. Pharmacy staff very rarely provided any information to purchasers concerning dose, when to take the medicine, or treatment duration. A logistic regression analysis showed that the probability of self-medication with antibiotics increased with several factors: age, education level, and the possibility of purchasing antibiotics on the marketplace. However, this risk decreased when patients were covered by medical insurance, when the public perceived the risks of self-medication, and when bacterial resistance was clearly defined. Conclusions. – This study was the first in the Ivory Coast to analyze the factors involved in antibiotic self-medication. It stressed the need to establish sustainable interventions to control the antibiotic use. [less ▲]

Detailed reference viewed: 150 (3 ULg)
See detailL'automesure de la pression artérielle
Saint-Remy, Annie ULg; Krzesinski, Jean-Marie ULg

Scientific conference (2010, January 12)

Detailed reference viewed: 13 (2 ULg)