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See detailDISSIPATIVITY AND GLOBAL ANALYSIS OF LIMIT CYCLES IN NETWORKS OF OSCILLATORS
Stan, Guy-Bart; Sepulchre, Rodolphe ULg

in Proceedings of the 16th Symposium on Mathematical Theory of Networks and Systems (2004, July)

This paper is concerned with the global analysis of synchrone oscillations in special networks of oscillators. In previous work, we de ned a class of highdimensional, parameter-dependent nonlinear systems ... [more ▼]

This paper is concerned with the global analysis of synchrone oscillations in special networks of oscillators. In previous work, we de ned a class of highdimensional, parameter-dependent nonlinear systems exhibiting almost globally asymptotically stable limit cycle oscillations. In this paper, we show how (incremental) dissipativity may be used to extend the global analysis of limit cycle oscillations to networks of coupled identical systems. [less ▲]

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See detailSystem optimization for residential SOFC 5 kW heat and electricity management
Lilien, Jean-Louis ULg; Lerson, Sébastien; Pochet, Nicolas

(2004, July)

A demonstration project will be presented using a 5 kW Solid Oxyde Fuel Cell for residential application in the region of Liège, Belgium. The current stage of the project is to evaluate the thermal ... [more ▼]

A demonstration project will be presented using a 5 kW Solid Oxyde Fuel Cell for residential application in the region of Liège, Belgium. The current stage of the project is to evaluate the thermal management of a single house with, at the present time, 45 MW.h (thermal 25 MW.h, electrical 20 MW.h) annual consumptions. The changes needed from a classical gas boiler heating of 20 kW to a 6 kW (thermal) plus 5 kW (electrical) system will be studied and detailed. Evaluation of CO2 reduction in the two systems will be presented considering the Belgium mix of electricity production. The heat and electricity local storage to cover peak demand in both energy demands will be discussed in relation with a grid-connected fuel cell. In particular the detailed analysis of this home demand will be analysed for the last three years. An original thermal circuit will be proposed, including its regulation. The experimental result of the behaviour of our proposal during 2003-2004 winter will be presented using a “virtual” SOFC (actually replaced by “equivalent” 6 kWth boiler) which is intended to be used in the same environment after this testing period. Constrains related to SOFC typical behaviour will be taken into account in our proposal for regulation. Depending on our development, it may be possible that up-to-date results may be given at the conference with a real system using a true SOFC 5 kW which would be in service after Septembre 2004. [less ▲]

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See detailUse of autogenous fascia lata graft for perineal herniorrhaphy in dogs: a preliminary study
Bongartz, Alexandre; Carofiglio, Francesca; Heimann, Marianne et al

in Proceedings du 13th Annual Scientific Meeting ECVS (2004, July)

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See detailSubspace Monitoring of Multivariate Dynamic Systems
Kruger, Uwe; Treasure, Richard; Dimitriadis, Grigorios ULg

in Akay, A.; Arnas, O.; Cooper, J. E. (Eds.) et al Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis (2004, July)

In this article, the monitoring of continuous processes using linear dynamic models is presented. It is outlined that dynamic extensions to conventional multivariate statistical process control (MSPC ... [more ▼]

In this article, the monitoring of continuous processes using linear dynamic models is presented. It is outlined that dynamic extensions to conventional multivariate statistical process control (MSPC) models may lead to the inclusion of large numbers of variables in the condition monitor. To prevent this, a new dynamic monitoring scheme, based on subspace identification, is introduced, which can (i) determine a set of state variable for describing process dynamics and (ii) produce a reduced set of variables to monitor process performance. This is demonstrated by an application study to a realistic simulation of a chemical process. [less ▲]

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See detailNonlinear System Identification using Interpolated Short Time Fourier Transform
Shi, Dongfeng; Dimitriadis, Grigorios ULg

in Akay, A.; Arnas, O.; Cooper, J. E. (Eds.) et al Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis (2004, July)

For the purpose of constructing the backbone of nonlinear systems, the Interpolated Short Time Fourier Transform (ISTFT) is proposed as a means to improve the estimation accuracy of the instantaneous ... [more ▼]

For the purpose of constructing the backbone of nonlinear systems, the Interpolated Short Time Fourier Transform (ISTFT) is proposed as a means to improve the estimation accuracy of the instantaneous amplitudes and frequencies of response signals. It is shown that the backbone curves estimated by the ISTFT agree with theoretical backbone curves very well. Additionally, the restoring force can be reconstructed to specify the type of nonlinear stiffness. A curve-fitting technique is introduced to estimate the parameters of nonlinear systems on the basis of theoretical backbone curves. It is shown that a number of typical nonlinear stiffness functions such as cubic, bilinear and pre-compressed springs can be identified accurately using this new method. [less ▲]

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See detailIdentification and model Updating of a non-stationary vibrating system
Dimitriadis, Grigorios ULg; Fassois, Spilios; Poulimenos, Aggelos et al

in Akay, A.; Arnas, O.; Cooper, J. E. (Eds.) et al Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis (2004, July)

Non-stationary systems, which are commonly encountered in many fields of science, are characterized by time-varying features and require time-frequency methods for their analysis. This study considers the ... [more ▼]

Non-stationary systems, which are commonly encountered in many fields of science, are characterized by time-varying features and require time-frequency methods for their analysis. This study considers the problem of identification and model updating of a non-stationary vibrating system. In particular, a number of identification methods and a model updating procedure are evaluated and compared through application to a time-varying “bridge-like” laboratory structure. The identification approaches include Frequency Response Function based parameter estimation techniques, Subspace Identification and Functional Series modelling. All methods are applied to both output-only and input-out-put data. Model updating is based upon a theoretical model of the structure obtained using a Rayleigh-Ritz methodology, which is updated to account for time-dependence and nonlinearity via the identification results. Interesting comparisons, among both identification and model updating results, are performed. The results of the study demonstrate high modelling accuracy, illustrating the effectiveness of model updating techniques in non-stationary vibration modelling. [less ▲]

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See detailMultiple Frequency Analysis Methods for Blade Tip-Timing Data Analysis
Gallego-Garrido, Jon; Dimitriadis, Grigorios ULg

in Akay, A.; Arnas, O.; Cooper, J. E. (Eds.) et al Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis (2004, July)

Blade Tip-Timing (BTT) is a method for the measurement of blade vibration in rotating bladed assemblies such as those found in turbomachinery. The system aims to replace strain gauge technology. However ... [more ▼]

Blade Tip-Timing (BTT) is a method for the measurement of blade vibration in rotating bladed assemblies such as those found in turbomachinery. The system aims to replace strain gauge technology. However all current BTT analysis methods fail to recover the correct frequencies when two blade modes are excited simultaneously by a synchronous vibration. In this paper, five new methods that can recover simultaneous frequencies from BTT data are presented. The methods are based on the auto-regressive approach. The approaches make use of data either from a single blade and single revolution or from multiple revolutions. Furthermore, some of the methods are designed to allow for the presence of measurement errors. The techniques are validated on three test cases in which simulated data was used. It is shown that most of the methods produce accurate estimates for the vibration frequency, even in the presence of significant noise levels, provided that a suitable amount of the response waveform is measured. The most consistent estimates are obtained from the methods that make use of data from multiple revolutions. [less ▲]

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See detail3D simulation of Industrial Hall in case of fire. Benchmark between ABAQUS, ANSYS and SAFIR
Vassart, Olivier; Cajot, Louis-Guy; O'Connor, Marc et al

in Interflam2004 Proceedings. Fire Sciences and Engineering Conference (2004, July)

For simple storey buildings, the structural behaviour in case of fire is relevant only for the safety of the firemen. The protection of occupants and goods is a matter of fire spread, smoke propagation ... [more ▼]

For simple storey buildings, the structural behaviour in case of fire is relevant only for the safety of the firemen. The protection of occupants and goods is a matter of fire spread, smoke propagation, active fire fighting measures and evacuation facilities. Brittle failure, progressive collapse and partial failure of façades elements outwards may endanger the fire fighters and have to be avoided. In order to deal with such an objective, the simulation softwares has to cover the 3D structural behaviour including membrane and restrained effects as well as the failure mode so that post-local failure stage can be analysed. Such calculation models (ANSYS, ABAQUS and SAFIR [1]) have been compared true a benchmark. In this benchmark, two different users used ABAQUS. [less ▲]

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See detailWake-Induced Vibration in Power Transmission Line. Parametric study
Lilien, Jean-Louis ULg; Snegovski, Dmitri

in Flow Induced Vibration - FIV 2004 (2004, July)

The paper discusses some aspects of modeling the wake-induced vibrations of the bundle conductors in transmission lines. The wake coupling between subconductors is modeled with the modified Simpson’s ... [more ▼]

The paper discusses some aspects of modeling the wake-induced vibrations of the bundle conductors in transmission lines. The wake coupling between subconductors is modeled with the modified Simpson’s approach. In order to apply this model to the analysis of power transmission line (PTL), a modal representation of a span could be used. In present paper we study how application of Dynamic Reduction (Component Mode) technique may improve such analysis under finite-element approach. The present paper, to extent of authors’ knowledge, is the first where Component Mode method application is discussed to study the subspan oscillation. Finally, bundled conductors’ susceptibility to wake-induced vibrations is illustrated on an exemplary twin-bundle, three-subspan model. Effects of bundle parameters (initial subconductor spacing, frequency ratio, subconductor mass), and the means to account them when applying the component mode method are discussed. [less ▲]

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See detailL'attachement et ses difficultés: repérages et compréhension
Battisti, Oreste ULg

in Bertrand, Jean Marie (Ed.) Troisième journée interactive du CHVE-CHC (2004, June 19)

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See detailExperimental and analytical investigations on single-sided composite joint configuration
Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg

in Walraven, Joost; Blaauwendraad, Johan; Scarpas, Tom (Eds.) et al 5th International PhD Symposium in Civil Engineering (2004, June 16)

For three years, in the framework of a European research project funded by the European Community for Steel and Coal (ECSC) in which the Liège University was deeply involved, intensive experimental ... [more ▼]

For three years, in the framework of a European research project funded by the European Community for Steel and Coal (ECSC) in which the Liège University was deeply involved, intensive experimental, numerical and theoretical investigations have been carried out on the behaviour of composite sway buildings under static and seismic loading. This paper presents experimental and analytical studies carried out at Liège University, as part of the above European project, with the objective to investigate the behaviour of a single-sided composite joint configuration under static loading. A particular failure mode occurred during the experimental tests, which had not yet been detected previously; it is described in details. Then, an analytical formula covering this particular phenomenon and based on a theoretical model is presented; it is validated through comparisons with experimental results. [less ▲]

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See detailObesity resulted in a significant increase in blood lipids in dogs
Jeusette, Isabelle; Lhoest, Estelle; Istasse, Louis et al

in Proceedings of the AAVN Clinical Nutrition and Research Symposium (2004, June 09)

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See detailSWAP: Sun watcher with a new EUV telescope on a technology demonstration platform
Defise, Jean-Marc ULg; Lecat, Jean-Hervé ULg; Mazy, Emmanuel ULg et al

in 5th International Conference on Space Optics (2004, June 01)

SWAP (SWAP (Sun Watcher using Active Pixel System detector and Image Processing) is an instrument that has been selected to fly on the PROBA-2 technology demonstration platform, a program of the European ... [more ▼]

SWAP (SWAP (Sun Watcher using Active Pixel System detector and Image Processing) is an instrument that has been selected to fly on the PROBA-2 technology demonstration platform, a program of the European Space Agency (ESA) to be launched in 2006. SWAP is based on an off-axis degraded Ritchey Chretien telescope that will image the EUV solar corona at 19.5 nm on a specifically fabricated extreme ultraviolet (EUV) sensitivity enhanced CMOS APS detector. The optical design and the optical coatings are derived from the Extreme Ultraviolet Imaging Telescope (EIT) operating on-board SOHO since 1995. It has been adapted for a single wavelength telescope with off-axis optics. It allows to use smaller optics and filters, with simple internal baffles avoiding external protruding parts. The superpolished optics will receive a multilayer coating that provides spectral selection centred on 19.5 nm and EUV reflectivity in normal incidence. This compact design is specifically adapted for accommodation on PROBA-2, where mass and envelope requirements are very stringent The SWAP PROBA-2 program will be an opportunity to demonstrate this new optical concept, while it will also validate space remote sensing with APS detectors, as well as on-board image processing capabilities. On the science outcomes, SWAP will provide solar corona images in the Fe XII line on a baselined 2-min cadence. Observations with this specific wavelength allow detecting phenomena, such as solar flares or 'EIT-waves', associated with the early phase of coronal mass ejections. The SWAP data will complement the observations provided by SOHO-EIT, and STEREO-SECCHI. [less ▲]

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See detailDevelopment of optical ground verification method for mum to sub-mm reflectors
Stockman, Yvan ULg; Thizy, Cédric ULg; Lemaire, Philippe ULg et al

in 5th International Conference on Space Optics (2004, June 01)

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. Scientific ... [more ▼]

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. Scientific observatories require large telescopes with precisely shaped reflectors for collecting the electro-magnetic radiation from faint sources. The challenging tasks of on-ground testing are to achieve the required accuracy in the measurement of the reflector shapes and antenna structures and to verify their performance under simulated space conditions (vacuum, low temperatures). Due to the specific surface characteristics of reflectors operating in these spectral regions, standard optical metrology methods employed in the visible spectrum do not provide useful measurement results. The current state-of-the-art commercial metrology systems are not able to measure these types of reflectors because they have to face the measurement of shape and waviness over relatively large areas with a large deformation dynamic range and encompassing a wide range of spatial frequencies. 3-D metrology (tactile coordinate measurement) machines are generally used during the manufacturing process. Unfortunately, these instruments cannot be used in the operational environmental conditions of the reflector. The application of standard visible wavelength interferometric methods is very limited or impossible due to the large relative surface roughnesses involved. A small number of infrared interferometers have been commercially developed over the last 10 years but their applications have also been limited due to poor dynamic range and the restricted spatial resolution of their detectors. These restrictions affect also the surface error slopes that can be captured and makes their application to surfaces manufactured using CRFP honeycomb technologies rather difficult or impossible. It has therefore been considered essential, from the viewpoint of supporting future ESA exploration missions, to develop and realise suitable verification tools based on infrared interferometry and other optical techniques for testing large reflector structures, telescope configurations and their performances under simulated space conditions. The first one is an IR-phase shifting interferometer with high spatial resolution. This interferometer shall be used specifically for the verification of high precision IR, FIR and sub-mm reflector surfaces and telescopes under both ambient and thermal vacuum conditions. The second one presented hereafter is a holographic method for relative shape measurement. The holographic solution proposed makes use of a home built vacuum compatible holographic camera that allows displacement measurements from typically 20 nanometres to 25 microns in one shot. An iterative process allows the measurement of a total of up to several mm of deformation. Uniquely the system is designed to measure both specular and diffuse surfaces. [less ▲]

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See detailA Search for Rotationally Modulated Halpha Variability in OB Supergiants
Morel, Thierry ULg; Marchenko, S. V.; Pati, A. K. et al

in Stellar Rotation (2004, June 01)

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See detailAn MHD-driven Disk Wind Outflow in SDSS J0300+0048?
Hall, Patrick; Hutsemekers, Damien ULg

in AGN Physics with the Sloan Digital Sky Survey. ASPC 311 (2004, June 01)

The outflow in SDSS J0300+0048 has the highest column density yet reported for a broad absorption line quasar. The absorption from different ions is also segregated as a function of velocity in a way that ... [more ▼]

The outflow in SDSS J0300+0048 has the highest column density yet reported for a broad absorption line quasar. The absorption from different ions is also segregated as a function of velocity in a way that can only be explained by a disk wind outflow. Furthermore, the presence of the such large column densities of gas at the high observed outflow velocities may be incompatible with purely radiative acceleration. MHD contributions to the acceleration should be considered seriously. [less ▲]

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See detailUndervoltage load shedding scheme for the Hydro-Québec system
Lefebvre, Daniel; Bernard, Serge; Van Cutsem, Thierry ULg

(2004, June)

In recent years, Hydro-Québec has undertaken a major program to upgrade the reliability of its transmission system. Much effort has been focused on increasing the system's ability to withstand extreme ... [more ▼]

In recent years, Hydro-Québec has undertaken a major program to upgrade the reliability of its transmission system. Much effort has been focused on increasing the system's ability to withstand extreme contingencies, usually caused by multiple incidents or the successive tripping of transmission lines. This paper deals with the conception and the control logic of an undervoltage load shedding scheme aimed at protecting the Hydro-Québec system against long-term voltage instability. Various results showing the impact of the operation of these automatisms on the system stability are provided in this paper. [less ▲]

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See detailAnalytical, physiological and clinical validation of a radioimmunoassay for serum Procollagen Type-III aminoterminal peptide in the dog
Schuller, S.; Valentin, S.; Remy, B. et al

in 14th ESVIM Meeting - Barcelona - Espagne (2004, June)

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See detailMaîtrise des bonnes pratiques d'hygiène.
Sindic, Marianne ULg

in Proceedings 4ème Congrès National d'hygiène alimentaire et de nutrition humaine. (2004, June)

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See detailCombining classification techniques with Kalman filters for aircraft engine diagnostics
Dewallef, Pierre ULg; Léonard, Olivier ULg; Mathioudakis, Kostas et al

in Proceedings of the ASME Turbo Expo 2004 (2004, June)

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See detailA Microstructural Study of Doped-LaGaO3 (La0.9Sr0.1Ga0.8Mg0.2O2.85) Produced by an Autocombustion from a Gel-like Precursor
Traina, Karl ULg; Pirard, Jean-Paul; Rulmont, André ULg et al

in Bossel, Ulf (Ed.) Sixth European Solid Oxide Fuel Cell Forum - Proceedings (2004, June)

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in ... [more ▼]

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in preparing a LSGM precursor from a freeze-dried Agar-Agar gel. After the freeze-drying step, the dry residue is put in an oven at 120°C where autocombustion occurred. The as-produced powders are then calcined. Investigations are made to follow both structural and microstructural evolutions from the dry residue to the end product. The effect of the temperature evolution was examined by thermogravimetric analysis, X-ray diffraction, environmental scanning electron microscopy, and specific surface area analysis. Dilatometric curves and density measurements have been also performed on the sintered products. Advantages of this method are the ability to control size distribution and to obtain high density materials without any milling step thus avoiding any contamination coming from the grinding medium. [less ▲]

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See detailOn-Line Aircraft Engine Diagnostic Using a Soft-Constrained Kalman Filter
Dewallef, Pierre ULg; Léonard, Olivier ULg; Mathioudakis, Kostas

in Proceedings of the ASME Turbo Expo 2004 (2004, June)

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See detailAdvances in pulsed holographic interferometry with photorefractive crystals
Georges, Marc ULg; Pauliat, B.; Alexeenko, I. et al

in Tomasini, E. (Ed.) 6th Intl Conf on Vibration Measurements by Laser Techniques : Advances and Applications (2004, June)

Photorefractive crystals offer many advantages over other classical holographic recording media. They allow fast in-situ processable holographic recording as well as indefinite reusability. Moreover high ... [more ▼]

Photorefractive crystals offer many advantages over other classical holographic recording media. They allow fast in-situ processable holographic recording as well as indefinite reusability. Moreover high signal-to-noise ratio can be reached as well as high resolutions. We present the results obtained by pulsed holographic interferometry obtained with photorefractive crystals. First experiments showing the potentiality of photorefractive crystals for such applications will be reviewed. Some limitations were pointed out and led us to consider new developments under the frame of an European-funded project. The PHIFE European project (Pulsed Holographic Interferometer for the analysis of Fast Events) aims at developing a full field measurement system at a high repetition rate, based on a double-pulse YAG Q-switch laser. This device will be used for the analysis of vibrations and for aerodynamic studies. Different crystals are considered which are adapted to the fundamental line of the YAG (AsGa or CdTe crystals) or after frequency doubling at 532 nm (Bi/sub 12/SiO /sub 20/). Different crystal configurations and recording geometries are compared. Also different innovative phase quantification techniques are studied and take into account some special properties of the PRCs. We present the results obtained so far in the first development phases of the project [less ▲]

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See detailPreventive use of bronchodilators reduces bronchoscopy-induced airflow limitation in cats
Kirschvink, N.; Leemans, J.; Delvaux, F. et al

in ACVIM Meeting - Minneapolis - USA - Juin 2004 (2004, June)

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See detailSolving the m-TSP Problem with Stochastic or Time Dependent Demands
Louveaux, François; Schyns, Michael ULg

in Opasanon, S.; Miller-Hooks, E. (Eds.) Proceedings of TRISTAN V (Triennial Symposium on Transportation Analysis) (2004, June)

There are many examples of problems in transportation where some elements are uncertain. In the distribution of goods as well as systems responding to calls for emergency, demands typically occur in a ... [more ▼]

There are many examples of problems in transportation where some elements are uncertain. In the distribution of goods as well as systems responding to calls for emergency, demands typically occur in a random fashion. Transportation systems have thus to be created in face of uncertainty about future levels of demands, making strategic decisions difficult to take. Similarly, traffic conditions vary randomly over time and travel routes are usually designed in face of uncertainty about traffic conditions, hence about effective travel times. Stochastic models, i.e. models that take uncertainty explicitly into account, have thus a central role to play in transportation. [less ▲]

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See detailEnergy restriction during a weight loss program must be stricter in female than male dogs
Jeusette, Isabelle; Biourge, Vincent; Nguyen, Patrick et al

in Proceedings of the ACVIM Forum 2004 (2004, June)

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See detailTCP Vegas-like algorithm for layered multicast transmission
Ait-Hellal, Omar; Leduc, Guy ULg

in Communications in Computing (2004, June)

Layered multicast is probably the most elegant solution to tackle the heterogeneity problem in multicast delivery of real-time multimedia streams. However, the multiple join experiments carried out by ... [more ▼]

Layered multicast is probably the most elegant solution to tackle the heterogeneity problem in multicast delivery of real-time multimedia streams. However, the multiple join experiments carried out by different receivers in order to detect the available bandwidth make it hard to achieve fairness. In the present paper, we present a simple protocol, inspired from TCP-Vegas, that reduces considerably the unnecessary join experiments while achieving intra-session and inter-session fairness as well as being TCP-Friendly. [less ▲]

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See detailModélisation des effets chimiques dans les argiles partiellement saturées.
Boukpeti, N.; Liu, Z.; Charlier, Robert ULg

in Journées Nationales de Géotechnique et de Géologie de l'Ingénieur (2004, June)

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See detailProcessing and Characterization of Electrolytes Based on Doped Lanthanum Gallates for IT-SOFCs.
Traina, Karl ULg; Cloots, Rudi ULg

in Bossel, Ulf (Ed.) Sixth European Solid Oxide Fuel Cell Forum - Proceedings (2004, June)

Nowadays a huge interest exists towards the SOFC’s coming out on the large-scale market because of the variety of their advantageous applications. Clean conversion of chemical energy to electricity, co ... [more ▼]

Nowadays a huge interest exists towards the SOFC’s coming out on the large-scale market because of the variety of their advantageous applications. Clean conversion of chemical energy to electricity, co-generation of electricity and chemicals, low levels of noise and vibration, flexibility regarding the fuels used, high efhciency are evidences of this statement. One of the problems that still exist in this field concerns the effective and cost reasonable operation of SOFCs. In this context the lowering of the operation temperatures could be one of the solutions to this important issue. Because of their excellent oxide—ion conductivity and stability over a broad range of oxygen partial pressure, the appropriate doped lanthanum gallates are promising alternative electrolytes for intermediate temperature SOFCs (lT-SOFCs). The aim of this work is to present the experimental results, obtained in a close collaboration between the two Universities. The objects could be briefly outlined, as follows: to process planar electrolytes with different thicknesses, based on doped LaGaO3 via traditional ceramic techniques; to study the influence of the dopants type and their amount on the properties of electrolyte materials synthesized; to investigate the phase formation and phase composition in correlation with the phase diagrams, as well as the microstructure and elements distribution. A special emphasis was placed upon the electrochemical characterization in broad temperature range, using impedance spectroscopy. The results obtained have been discussed in details and conclusions have been drawn by common efforts of the two working groups. [less ▲]

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See detailLe système HACCP : évolution de la législation alimentaire européenne.
Anceau, Christine ULg; Sindic, Marianne ULg; Deroannne, Claude

in Proceedings 4ème Congrès national d'hygiène alimentaire et de nutrition humaine. (2004, June)

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See detailPerformance Study of an Overlay Approach to Active Routing in Ad Hoc Networks
Calomme, Sandrine; Leduc, Guy ULg

(2004, June)

We motivate the use of the active technology for routing in ad hoc networks. We present an active architecture where passive and active nodes can operate together, avoiding any change in the legacy muti ... [more ▼]

We motivate the use of the active technology for routing in ad hoc networks. We present an active architecture where passive and active nodes can operate together, avoiding any change in the legacy muti-hop routing protocol they use. We detail a basic reactive protocol which can be used to build any overlay on top of an ad hoc network. We model it as an active application called Re-Active Routing (RAR). RAR provides dynamic routing in dense and sparse active overlays. We investigate its performance in static and dynamic environments and show that it depends substantially on the active range, i.e. on the allowed maximal number of hops between two active nodes. For a well-chosen active range, RAR achieves good performance even if the mobility level is high and the overlay density is as low as 12.5 %. [less ▲]

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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 detailNumerical and analytical investigations on composite sway frames
Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg

in Modern Building Materials, Structures and Techniques (2004, May 19)

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check ... [more ▼]

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check structural elements like beams, columns, slabs and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems is susceptible to make global instability a relevant failure mode, what is not yet covered by Eurocode 4. For three years, in the framework of a European research project funded by the European Community for Steel and Coal (ECSC), in which Liège University was deeply involved, intensive experimental, numerical and theoretical investigations have been carried out. The latter aimed at improving the knowledge in the field of sway composite frames and at developing appropriate design rules. The rotational behaviour of the beam-to-column composite joints is one of the key aspects of the problem to which a special attention has been paid. This paper presents numerical and analytical studies carried out at Liège University, as part of the above European project, with the objective to investigate the behaviour of 2D composite sway frames under static loading. Particular phenomena put into sight through different analyses are illustrated herein. [less ▲]

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See detailOptimizing the ordering policy in a supply chain
Arda, Yasemin ULg; Hennet, Jean-Claude

in INCOM 04, 11th IFAC Symposium on Information Control Problems in Manufacturing, Salvador, Brazil, 5-7 April 2004 (2004, May 05)

This study analyzes an inventory management problem within a supply chain. An enterprise whose stock is replenished by outside suppliers faces random demands for one of its products. The objective is to ... [more ▼]

This study analyzes an inventory management problem within a supply chain. An enterprise whose stock is replenished by outside suppliers faces random demands for one of its products. The objective is to minimize the expected total cost for the enterprise, which includes the holding and shortage costs. The enterprise must choose the suppliers to whom the orders are sent while minimizing the costs. If the enterprise sends all the orders to the same supplier during the planning period, the supplier who has the maximum service rate must be chosen. In the case of choosing possibly different suppliers for different orders, the supplying system is modelled as an open queuing network and explicit expressions are obtained for the average total cost as a function of the decision variables. Numerical results measure the advantage for the producer to use different suppliers instead of a single one. [less ▲]

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See detailg-mode pulsations in slowly pulsating B stars
De Cat, P.; Daszynska-Daszkiewicz, J.; Briquet, Maryline ULg et al

in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)

In this paper, we give an updated overview of the observed characteristics of g-mode pulsations in slowly pulsating B stars. These characteristics are based on the combined results of linear nonadiabatic ... [more ▼]

In this paper, we give an updated overview of the observed characteristics of g-mode pulsations in slowly pulsating B stars. These characteristics are based on the combined results of linear nonadiabatic analysis of the oscillations and a photometric and spectroscopic mode identification for a sample of 13 members. For 4 stars, at least one mode is stable in all the considered theoretical models. [less ▲]

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See detailMode identification using photometry and spectroscopy
De Ridder, Joris; Aerts, Conny; Dupret, Marc-Antoine ULg

in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)

We tested a stepwise approach to combine photometry and spectroscopy for mode identificaiton where we first used the photometric amplitude ratios to restrict the degree l, then did a spectroscopic mode ... [more ▼]

We tested a stepwise approach to combine photometry and spectroscopy for mode identificaiton where we first used the photometric amplitude ratios to restrict the degree l, then did a spectroscopic mode identification, and finally fitted the photometric amplitudes to restrict the list of candidate modes. For the spectroscopic mode identification, we implemented an efficient multi-mode moment method variant. We conclude that this new variant works well, but that the photometric amplitudes are too model sensitive to do any additional mode discrimination. [less ▲]

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See detailNon-adiabatic seismic study of the thin convective envelope of delta Scuti stars
Dupret, Marc-Antoine ULg; Grigahcène, A.; Garrido, R. et al

in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)

For delta Sct stars, the theoretical predictions of a non-adiabatic pulsation code are very dependent on the characteristics of the thin convective envelope of the models (Balona and Evers 1999). The ... [more ▼]

For delta Sct stars, the theoretical predictions of a non-adiabatic pulsation code are very dependent on the characteristics of the thin convective envelope of the models (Balona and Evers 1999). The treatment of the non-adiabatic interaction between convection and pulsation also has a significant impact on the results, particularly near the red edge of the instability strip. The non-adiabatic theoretical predictions can be tested upon observations by comparing them to the amplitude ratios and phase differences as observed in different color passbands (Dupret et al. 2003). In the first part of this paper, we compare the results obtained by adopting different treatments of convection in the interior and atmosphere models: mixing-length theory (MLT) and full spectrum of turbulence (FST) (Canuto et al. 1996, CGM). In the second part, we examine the problem of the interaction between convection and pulsation and compare the mode stability obtained with and without including time-dependent convection in our non-adiabatic code. [less ▲]

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See detailNonadiabatic observables in main sequence delta Scuti stars
Moya, A.; Garrido, R.; Dupret, Marc-Antoine ULg

in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)

Using a theoretical nonadiabatic pulsation model, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement have been calculated ... [more ▼]

Using a theoretical nonadiabatic pulsation model, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement have been calculated. These quantities, when compared with photometric observations in different colors, provide an efficient instrument for mode identification, the first step to understand the internal structure of the stars. The theoretical results presented in this paper show a dependence for delta Scuti stars on the mixing length parameter alpha used to treat the convection using the standard Mixing Length Theory. The nonadiabatic pulsational code developed here includes the pulsation atmosphere interaction as described by Dupret et al. (2002). The equilibrium models are provided by the CESAM evolutionary code, where a complete reconstruction of non-grey atmospheres (Kurucz models) is included. [less ▲]

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See detailNon-adiabatic asteroseismology of near-main sequence variable stars
Dupret, Marc-Antoine ULg

in IAU Colloq. 193: Variable Stars in the Local Group (2004, May 01)

We present in this talk a new linear non-adiabatic pulsation code: MAD[SUP]1[/SUP]. We detail all the possible applications of it in the frame of asteroseismology. By using it, photospheric observables ... [more ▼]

We present in this talk a new linear non-adiabatic pulsation code: MAD[SUP]1[/SUP]. We detail all the possible applications of it in the frame of asteroseismology. By using it, photospheric observables such as multi-color photometric amplitude ratios, phase differences and line profile variations can be determined accurately and confronted with observations. Moreover, MAD enables the precisely analysis of the excitation mechanisms of pulsating stars. Applications to different kinds of variable stars (delta Sct, beta Cephei, Slowly Pulsating B and gamma Dor stars) are presented by Dupret et al. (these proceedings), Handler and Aerts (these proceedings), De Cat et al. (these proceedings) and De Ridder et al. (these proceedings). [less ▲]

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See detailA Constitutive Model for Chemically Sensitive Clays.
Boukpeti, N.; Charlier, Robert ULg; Hueckel, T. et al

in Lecture Notes in Earth Sciences n°104 (2004, May)

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See detailIncrease of MMP-2 and MMP-9 activity in bronchoalveolar lavage fluid of Ascaris suum sensitized cats and correlation with inflammatory and morphological variables
Kirshvink, N.; Delvaux, François ULg; Vincke, G. et al

in International Conference of the American Thoracic Society - Orlando - USA - Mai 2004 (2004, May)

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See detailUsing the complete Nano Engineering Geological Spectrum to assess the Performance of Clay
Schmitz, R. M.; Schroeder, Christian ULg; Thorez, Jacques ULg et al

in Lecture Notes in Earth Sciences n°104 (2004, May)

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See detailPerformance relative des règles linéaire, quadratique et logistique en analyse discriminante
Glele Kakaï, R.; Palm, Rodolphe ULg

in XXXVIèmes Journées de Statistique (2004, May)

Monte Carlo study is achieved to compare linear, quadratic and logistic classification rules for two groups, in 480 situations related to the type of distribution, the overlap of the populations, the ... [more ▼]

Monte Carlo study is achieved to compare linear, quadratic and logistic classification rules for two groups, in 480 situations related to the type of distribution, the overlap of the populations, the number of variables, the sample size and the heteroscedasticity degree of the model, which is measured by a parameter gamma defined in the study. The results of this study show that the quadratic rule is the best only for severe heteroscedastic normal or moderate non-normal models with high overlap. The linear rule is the best for homoscedastic normal or moderate non-normal models with low overlap. The logistic rule is the best for severe non-normal models except when homoscedasticity occurs. In the order situations linear and logistic rules have almost the same performance. By considering the parameters computed on the data samples, the linear rule gives the best performance for high values of r whereas logistic rule performs is best for low or moderate values of the same parameter. [less ▲]

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See detailDevelopment of non radioactive multi-analyte methodes based on the use of a recombinant human beta2-agonists and antagonists residues in food-producing animals
Danyi, Sophie ULg; Degand, Guy ULg; Granier, Benoît et al

in Proceedings Euroresidue V conference on residues of veterinary drugs in food (2004, May)

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See detailDoes insuline resistance in acromegaly differ from that in diabetes ?
Beckers, Albert ULg

in Growth and Beyond Workshop Summary : 16-17 May 2004 (2004, May)

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See detailEvaluation of the group B differential agar for the detection of group B streptococci from vaginal specimens
MELIN, Pierrette ULg; Rodriguez Cuns, Grisel; Lorquet, Sophie et al

in American Society of Microbiology (Ed.) Program and Abstracts of the 104th General Meeting of the American Society for Microbiology (2004, May)

Background Group B streptococci (GBS) are the leading cause of severe perinatal infections. Most current guidelines for the prevention of GBS perinatal disease are based on prenatal screening culture for ... [more ▼]

Background Group B streptococci (GBS) are the leading cause of severe perinatal infections. Most current guidelines for the prevention of GBS perinatal disease are based on prenatal screening culture for vaginal GBS colonisation. Use of selective and differential media could improve the sensitivity of these cultures. Objective To evaluate the GBS-Differential Agar (GBSDA) recently formulated by Becton Dickinson for the selective growth and production of orange colonies of b- hemolytic (b-H) GBS. Methods 283 vaginal swabs (VAG) collected from pregnant women were inoculated in selective Lim broth. After overnight incubation, Lim broth were subcultured on GBSDA, on Granada agar (Biomedics, Spain) and on Columbia blood agar (BA). To evaluate the stability, 99 isolates of GBS (REF) from adult or neonatal infections (Belgian GBS reference laboratory collection) were cultured on GBSDA and Granada at their limit of expiration, and on BA. GBSDA and Granada were incubated anaerobically and BA aerobically + 7% CO2, at 35°C, 24 to 48 h. Positive and negative control strains (GBS ; E. faecalis) were cultured with each run. Specific identification of colonies suggestive of GBS (pale to dark orange on GBSDA and Granada, b-H on BA) was performed. Results b-H GBS were recovered from 63 VAG (22.3 %): 62 were easily identified after overnight incubation on GBSDA and 63 on Granada without requiring any subculture. All GBS were also recovered from BA however it was after many subcultures. All orange colonies were confirmed as GBS. Among REF, 3 strains were non hemolytic ; they grew but were not differentiated as orange colonies on GBSDA or Granada. 96 REF were b-H, 94 (97.9%) produced orange to very dark orange colonies on GBSDA, 2 produced white colonies, and on Granada, 74 (77.1 %) produced pale to dark orange colonies and 22 white to white-orange colonies. Conclusion 1) GBSDA and Granada: a) very high sensitivity and specificity for the detection of b-H GBS, in a single step b) Results available within 48 h after inoculation in Lim broth, low workload 2) Excellent stability up to expiration date for GBSDA 3) Non hemolytic GBS: grown but not differentiated on GBSDA or Granada. [less ▲]

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See detailChatter maps for process design of powertrain components
Masset, Luc ULg; Debongnie, Jean-François ULg; Belluco, Walter

in Moisan, Alphonse; Poulachon, Gérard (Eds.) Proceedings of the 7th CIRP International Workshop on Modeling of Machining Operations (2004, May)

During rough machining operations of powertrain components, chatter vibrations may occur on the edges of flexible structures. This paper presents a numerical method, based on the finite element method and ... [more ▼]

During rough machining operations of powertrain components, chatter vibrations may occur on the edges of flexible structures. This paper presents a numerical method, based on the finite element method and Tlusty's theory, which gives a chatter map of the machined surface. Each map point represents the greatest depth of cut leading to unconditionally stable cut. Each value depends on the structural damping, the cutting stiffness and the local static stiffness, which is computed using conventional linear elastic FEA. Chatter maps offer a convenient and effective decision support system for robust process design. As a case study, the rough milling operation of a crankcase deck face with a two-stage cutter is presented. [less ▲]

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See detailL’isocinétisme, une arme de choix
Croisier, Jean-Louis ULg

in Actes du Congrès International de Médecine du Sport (2004, April 23)

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See detailRoles and competencies of the e-tutor
Denis, Brigitte ULg; Watland, Philip; Pirotte, Sébastien et al

in Banks, S.; Goodyear, P.; Hogdson, V. (Eds.) et al Networked learning 2004 : a research based conference on networked learning and lifelong learning : proceedings of the fourth international conference, Lancaster (2004, April 07)

This paper considers the roles and competencies of the e-tutor. A literature review shows that different roles are assigned to the online tutors. Definitions of these roles are presented and discussed ... [more ▼]

This paper considers the roles and competencies of the e-tutor. A literature review shows that different roles are assigned to the online tutors. Definitions of these roles are presented and discussed. Afterwards, we present eleven roles we consider important to manage the interactions between learners and tutors in an e-learning environment and the competencies needed to support these tutor’s roles. We conclude that to improve the quality of e-learning the tutor’s interventions have to be adapted to a specific context and we propose to train the e-tutors for these roles. [less ▲]

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See detailDevelopment of optical ground verification method for mu m to sub-mm reflectors
Stockman, Yvan ULg; Thizy, Cédric ULg; Lemaire, Philippe ULg et al

in Warmbein, B. (Ed.) Proceedings of the 5th International Conference on Space Optics (ICSO) (2004, April 02)

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. The ... [more ▼]

Large reflectors and antennas for the IR to mm wavelength range are being planned for many Earth observation and astronomical space missions and for commercial communication satellites as well. The challenging tasks of on-ground testing are to achieve the required accuracy in the measurement of the reflector shapes and antenna structures and to verify their performance under simulated space conditions (vacuum, low temperatures). A small number of infrared interferometers have been commercially developed over the last 10 years but their applications have also been limited due to poor dynamic range and the restricted spatial resolution of their detectors. It has therefore been considered essential, from the viewpoint of supporting future ESA exploration missions, to develop and realise suitable verification tools based on infrared interferometry and other optical techniques for testing large reflector structures, telescope configurations and their performances under simulated space conditions. Two methods and techniques are developed at CSL. The first one is an IR-phase shifting interferometer with high spatial resolution. This interferometer shall be used specifically for the verification of high precision IR, FIR and sub-mm reflector surfaces and telescopes under both ambient and thermal vacuum conditions. The second one presented hereafter is a holographic method for relative shape measurement. The holographic solution proposed makes use of a home built vacuum compatible holographic camera that allows displacement measurements from typically 20 nanometres to 25 microns in one shot. An iterative process allows the measurement of a total of up to several mm of deformation. Uniquely the system is designed to measure both specular and diffuse surfaces [less ▲]

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See detailPartial encryption of images for real-time applications
Van Droogenbroeck, Marc ULg

in Fourth IEEE Signal Processing Symposium (2004, April)

Multimedia systems mostly base security on a restricted access to services. In the context of real-time imaging applications, this model suffers several drawbacks. Applications become vulnerable to ... [more ▼]

Multimedia systems mostly base security on a restricted access to services. In the context of real-time imaging applications, this model suffers several drawbacks. Applications become vulnerable to password attacks and once exposed attackers have access to all the data. An alternative consists of the systematic encryption of all data. When dealing with images, this approach is inconvenient because the data needs to be processed in its entirety before users can gain any insight. As well, the decryption task requires large amounts of processing power. This presentation shows how partial encryption can match applications requirements without the overhead of full encryption. The paper rst analyzes several schemes mixing encryption and image encoding. Then we focus on a technique that implements partial encryption of images based on JPEG. The technique is built to meet two major requirements: (1) preserve the overall bitrate, and (2) remain compliant with the JPEG file format. Finally we introduce and elaborate on a new scheme that combines flexibility, multiple encryption, spatial selectivity, self sufficiency, and format compliance. We show how it could fit the needs of real-time applications. [less ▲]

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See detailEffect of various level of imbalance between energy ans nitrogen supplies on nitrogen metabolism in growing double-muscled Belgian Blue bulls.
Valkeners, Damien; Beckers, Yves ULg; Thewis, André ULg

in Proceeding of the British Society of Animal Science - Annual meeting (2004, April)

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See detailStability and Limit Cycle Oscillation Amplitude Prediction for Simple Nonlinear Aeroelastic Systems
Dimitriadis, Grigorios ULg; Vio, Gareth Arthur; Cooper, Jonathan Edward

in Proceedings of the 45th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference (2004, April)

The prediction of the bifurcation and post-bifurcation behaviour of nonlinear aeroelastic systems is becoming a major area of research in the aeroelastic community due to the need for improved transonic ... [more ▼]

The prediction of the bifurcation and post-bifurcation behaviour of nonlinear aeroelastic systems is becoming a major area of research in the aeroelastic community due to the need for improved transonic aeroelastic prediction, the use of non-linear control systems, and new construction techniques that reduce the amount of inherent damping. In this paper, a novel application of the Centre Manifold Theorem is used to accurately predict bifurcation conditions and Limit Cycle Oscillation amplitudes for simple aeroelastic systems with various types of nonlinearity. A simple aeroelastic system with hardening cubic stiffness nonlinearity is considered and is demonstrated to display a wide variety of bifurcation phenomena. These make it dif cult for some of the standard existing methods, such as Normal Form, Cell Mapping and Tangential Linearisation, to quantify the Limit Cycle Oscillation amplitudes through the entire speed range of the system. Then, the proposed approach is introduced and applied to the same system. It is shown that it can accurately predict the limit cycle amplitudes of the system undergoing all types of bifurcation. Finally, the new technique is applied to the same system but with softening cubic stiffness nonlinearity. It is shown that the method can accurately predict both the static and dynamic divergence boundaries and that it can be used to draw a worst-case stability boundary, inside which the solution is always stable. [less ▲]

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See detailRiver contract in the Sourou valley (Burkina Faso)
Rosillon, Françis ULg

in Muuka, Gerry Nkombo (Ed.) 2004 IAABD Proceedings (2004, April)

Inspired from the experience of river contract in Wallonia (Belgium) since 1990, this paper is describing the implementation of the first river contract in a West-African country, Burkina Faso. This ... [more ▼]

Inspired from the experience of river contract in Wallonia (Belgium) since 1990, this paper is describing the implementation of the first river contract in a West-African country, Burkina Faso. This application isn't limited to a simple transposition of the Walloon model. The Burkina context calls to adaptation to the local environmental and socio-economical realities with an adequate partnership management. The importance of the mobilissation around this project of institutional partners, as well as local collectivities this new tool of water participative management. But will the latter be equal to the task ? A first assessment has been drawn up one year after the launching. [less ▲]

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See detailSurgical debulking of GH secreting pituitary adenomas improves GH control of acromegaly by somatostatin analogs
Beckers, Albert ULg; Petrossians, Patrick ULg; Borges Martins, L. et al

in ENEA congress : Napoli, April 2004 (2004, April)

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See detailHormonal and biochemical normalization and tumor shrinkage induced by anti-parathyroid hormone immunotherapy in a patient with metastatic parathyroid carcinoma
Betea, Daniela ULg; Bradwell, A. R.; Harvey, T. C. et al

in ENEA congress : Napoli, April 2004 (2004, April)

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See detailApproaching the true prevalence of pituitary tumors
Beckers, Albert ULg; Adam, C.; Ciccarelli, A. et al

in ENEA congress : Napoli, April 2004 (2004, April)

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See detailMale hypogonadism caused by isolated LH deficiency : From pathology to gene, from gene to physiology
Valdes Socin, Hernan Gonzalo ULg; Salvi, R.; Pralong, F. et al

in ENEA congress : Napoli, April 2004 (2004, April)

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See detailModelling the seasonal cycle of the biological productivity in the Ligurian Sea by means of a 1D interdisciplinary model
Raick, C.; Soetaert, K.; Grégoire, Marilaure ULg

in VLIZ Young Scientists' Day, Brugge, Belgium 5 March 2004: book of abstracts. VLIZ Special Publication, 17 (2004, March 05)

A one-dimensional coupled physical-biogeochemical model has been built to study the pelagic food web of the Ligurian Sea (NW Mediterranean Sea). The physical model is the turbulent closure model (version ... [more ▼]

A one-dimensional coupled physical-biogeochemical model has been built to study the pelagic food web of the Ligurian Sea (NW Mediterranean Sea). The physical model is the turbulent closure model (version 1D) developed at the GeoHydrodynamics and Environmental Laboratory (GHER) of the University of Liège. The ecosystem model contains nineteen state variables describing the carbon and nitrogen cycles of the pelagic food web. Phytoplankton and zooplankton are both divided in three size-based compartments and the model includes an explicit representation of the microbial loop including bacteria, dissolved organic matter, nano-, and micro- zooplankton. The internal carbon/nitrogen ratio is assumed variable for phytoplankton and detritus, and constant for zooplankton and bacteria. Silicate is considered as a potential limiting nutrient of phytoplankton growth. The aggregation model described in Kriest and Evans (2000) is used to evaluate the sinking rate of particulate detritus. The model is forced at the air-sea interface by meteorological data coming from METEO France. The DYFAMED time series data obtained during the year 2000 are used to calibrate and validate the biological model. The comparison of model results within in-situ DYFAMED data shows that although some processes are not represented by the model, such as horizontal and vertical advections, model results are in good agreement with observations and differences observed can be explained with environmental conditions. [less ▲]

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See detailCharakterisierung des bronchialen “remodellings” in einem Modell von felinem Asthma
Kirschvink, N.; Delvaux, François ULg; Vincke, G. et al

in 45. Kongress der Deutschen Gesellschaft für Pneumologie - Frankfurt - Allemangne - Mars 2004 (2004, March)

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See detailImplication of surface charge effects in color removal from effluents by chemical coagulation - the case of CI Reactive Blue 4 dye
Gaydardzhiev, Stoyan ULg; Ay, Peter

in Pratsinis, S. (Ed.) Proceeedings CD of Partec 2004 Inetrnational Congress of Particle Technology (2004, March)

Characterisation of dye flcos during colour removal from synthetic waste water is presented. Surface charge and floc size and shapes are measured and an implications towards the predominant removal ... [more ▼]

Characterisation of dye flcos during colour removal from synthetic waste water is presented. Surface charge and floc size and shapes are measured and an implications towards the predominant removal emchanisms is made. [less ▲]

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See detailEvaluation de l'expression orale et de l'expression écrite en langues étrangères : présentation et analyse de différents outils
Beckers, Jacqueline ULg; Simons, Germain ULg; Van Hoof, Florence ULg et al

in Actes du 3ème congrès des chercheurs en éducation : (re)trouver le plaisir d'enseigner et d'apprendre. Construire savoirs et compétences (2004, March)

Cette communication présente une réflexion sur le type de tâches à proposer lors de l évaluation certificative, ensuite sur les critères à prendre en compte et enfin sur les indicateurs de réussite. Cette ... [more ▼]

Cette communication présente une réflexion sur le type de tâches à proposer lors de l évaluation certificative, ensuite sur les critères à prendre en compte et enfin sur les indicateurs de réussite. Cette réflexion repose d'une part sur un programme de recherche-action portant sur l optimisation de l expression orale en anglais/langue étrangère [2000-2002], et sur un autre programme de recherche-action portant sur l identification et la déconstruction de stéréotypes liés à la langue et à la culture étrangères (néerlandais et français) [2002-2004], et d'autre part sur les travaux réalisés au sein de la Commission de Pilotage du Système éducatif. [less ▲]

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See detailPrésentation de deux grandes approches didactiques destinées à articuler compétences et savoirs dans le domaine de l'apprentissage des langues étrangères en contexte scolaire
Beckers, Jacqueline ULg; Simons, Germain ULg; Van Hoof, Florence ULg et al

in Actes du 3ème congrès des chercheurs en éducation : (re)trouver le plaisir d'enseigner et d'apprendre. Construire savoirs et compétences (2004, March)

Dans cette communication, nous présenterons deux grandes approches didactiques destinées à articuler compétences et savoirs linguistiques dans le domaine de l enseignement de l anglais et du néerlandais ... [more ▼]

Dans cette communication, nous présenterons deux grandes approches didactiques destinées à articuler compétences et savoirs linguistiques dans le domaine de l enseignement de l anglais et du néerlandais/langues étrangères. Dans les deux cas, le public-cible est constitué d élèves évoluant dans l enseignement secondaire général supérieur. [less ▲]

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See detailLa coordination horizontale, un mode de gestion des compétences stratégique pour une justice face à de nouvelles exigences ?
Schoenaers, Frédéric ULg

in Management des compétences et des connaissances : outils stratégiques en GRH (2004, March)

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See detailION BEAM FIGURING OF CVD SILICON CARBIDE MIRRORS
Gailly, Patrick ULg

in Warmbein, B (Ed.) Proceedings of the 5th International Conference on Space Optics (ICSO 2004) (2004, March)

Optical and structural elements made of silicon carbide are increasingly found in space instruments. Chemical vapor deposited silicon carbide (CVD-SiC) is used as a reflective coating on SiC optics in ... [more ▼]

Optical and structural elements made of silicon carbide are increasingly found in space instruments. Chemical vapor deposited silicon carbide (CVD-SiC) is used as a reflective coating on SiC optics in reason of its good behavior under polishing. The advantage of applying ion beam figuring (IBF) to CVD-SiC over other surface figure-improving techniques is discussed herein. The results of an IBF sequence performed at the Centre Spatial de Liège on a 100 mm CVD-SiC mirror are reported. The process allowed to reduce the mirror surface errors from 243 nm to 13 nm rms . Beside the surface figure, roughness is another critical feature to consider in order to preserve the optical quality of CVD-SiC . Thus, experiments focusing on the evolution of roughness were performed in various ion beam etching conditions. The roughness of samples etched at different depths down to 3 m was determined with an optical profilometer. These measurements emphasize the importance of selecting the right combination of gas and beam energy to keep roughness at a low level. Kaufman-type ion sources are generally used to perform IBF but the performance of an end-Hall ion source in figuring CVD-SiC mirrors was also evaluated in this study. In order to do so, ion beam etching profiles obtained with the end-Hall source on CVD-SiC were measured and used as a basis for IBF simulations. [less ▲]

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See detailBilan d'une saison très tardive du point des maladies: Résultats des essais fongicides en 2003 sur le site de Lonzée
Vancutsem, Françoise ULg; Moreau, Jean-Marc; Bodson, Bernard ULg

in Fumure et protection phytosanitaire des céréales (2004, February 18)

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See detailLes conseils de fumure azotée
Bodson, Bernard ULg; Destain, Jean-Pierre ULg; Vancutsem, Françoise ULg et al

in Fumure et protection phytosanitaire des céréales (2004, February 18)

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See detailFroments alternatifs et de printemps
Couvreur, Luc; Vancutsem, Françoise ULg; Bodson, Bernard ULg et al

in Fumure et protection phytosanitaire des céréales (2004, February 18)

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See detailFractionnement de la fumure azotée: deux ou trois fractions? fumure au tallage ou pas?
Bodson, Bernard ULg; Vancutsem, Françoise ULg; Destain, Jean-Pierre ULg et al

in Fumure et protection phytosanitaire des céréales (2004, February 18)

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See detailInventory control in a multi-supplier system
Arda, Yasemin ULg; Hennet, Jean-Claude

in IGLS 04, 13th International Working Seminar on Production Economics, Igls/Innsbruck, Austria, 16-20 February 2004 (2004, February 16)

An enterprise network is analyzed from the viewpoint of an end-product manufacturer who receives customer orders and organises his production and supply policy so as to minimize the sum of his average ... [more ▼]

An enterprise network is analyzed from the viewpoint of an end-product manufacturer who receives customer orders and organises his production and supply policy so as to minimize the sum of his average holding cost and average stock-out cost. For each main component to be ordered, the producer has several possible suppliers. The arrivals of customers’ orders are random and delivery times from suppliers are also supposed random. This supply system is represented as a queuing network and the producer uses a base-stock inventory control policy that keeps constant the position inventory level (current inventory level + pending replenishment orders). The decision variables are the reference position inventory level and the percentages of orders sent to the different suppliers. In the queuing network model, the percentages of orders are implemented as Bernoulli branching parameters. A close-form expression of the expected cost criterion is obtained as a complex non-linear function of decision variables. A decomposed approach is proposed for solving the optimization problem in an approximate manner. The quality of the approximate solution is evaluated by comparison to the exact solution, which can be computed numerically in some simple cases, in particular in the two-supplier case. Numerical applications show the important economic advantage for the producer of sending orders to several suppliers rather than to a single one. [less ▲]

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See detailMAGRITTE optomechanical design and mirror manufacturing
Mazy, Emmanuel ULg; Defise, Jean-Marc ULg; Halain, Jean-Philippe ULg et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2004, February 01)

The MAGRITTE telescopes are part of the SHARPP instrument suite, part of the Solar Dynamics Observatory (SDO), a NASA spacecraft to be launched in a geostationnary orbit in 2007. The MAGRITTE instrument ... [more ▼]

The MAGRITTE telescopes are part of the SHARPP instrument suite, part of the Solar Dynamics Observatory (SDO), a NASA spacecraft to be launched in a geostationnary orbit in 2007. The MAGRITTE instrument package will provide high resolution images of the solar corona at high temporal frequency simultaneously in 5 EUV and in Ly-alpha narrow bandpasses. The 1.4 R[SUB]0[/SUB] MAGRITTE common field of view complements the other SHARPP instruments, as well as its spectral coverage with 6 narrow bandpasses located within the 19.5 to 120 nm interval. The key challenges of the MAGRITTE instrument are a high angular resolution (0.66 arcsec/pixel) with a high responsivity (exposure times smaller than 8 sec), combined with restricted spacecraft resources. The design of MAGRITTE is based on a high performance off-axis Ritchey-Chretien optical system combined with a large detector (4 K x 4 K, 12 µm pixel). The tight pointing stability performance of 1.2 arcsec over the image exposure time requires an active image motion control, using pointing information of a Guide Telescope, to compensate low frequency boresight variations produced by spacecraft jitter. The thermomechanical design and the mirror polishing are highly critical issues in the instrument design. This paper presents the MAGRITTE design concept with the expected performances based on a realistic error budget. The mirror polishing concept and performances are discussed. [less ▲]

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See detailMAGRITTE: an instrument suite for the solar atmospheric imaging assembly (AIA) aboard the Solar Dynamics Observatory
Rochus, Pierre ULg; Defise, Jean-Marc ULg; Halain, Jean-Philippe ULg et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2004, February 01)

The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory will characterize the dynamical evolution of the solar plasma from the chromosphere to the corona, and will follow the ... [more ▼]

The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory will characterize the dynamical evolution of the solar plasma from the chromosphere to the corona, and will follow the connection of plasma dynamics with magnetic activity throughout the solar atmosphere. The AIA consists of 7 high-resolution imaging telescopes in the following spectral bandpasses: 1215Å. Ly-a, 304 Å He II, 629 Å OV, 465 Å Ne VII, 195 Å Fe XII (includes Fe XXIV), 284 Å Fe XV, and 335 Å Fe XVI. The telescopes are grouped by instrumental approach: the MAGRITTE Filtergraphs (R. MAGRITTE, famous 20th Century Belgian Surrealistic Artist), five multilayer EUV channels with bandpasses ranging from 195 to 1216 Å, and the SPECTRE Spectroheliograph with one soft-EUV channel at OV 629 Å. They will be simultaneously operated with a 10-second imaging cadence. These two instruments, the electronic boxes and two redundant Guide Telescopes (GT) constitute the AIA suite. They will be mounted and coaligned on a dedicated common optical bench. The GTs will provide pointing jitter information to the whole SHARPP assembly. This paper presents the selected technologies, the different challenges, the trade-offs to be made in phase A, and the model philosophy. From a scientific viewpoint, the unique combination high temporal and spatial resolutions with the simultaneous multi-channel capability will allow MAGRITTE / SPECTRE to explore new domains in the dynamics of the solar atmosphere, in particular the fast small-scale phenomena. We show how the spectral channels of the different instruments were derived to fulfill the AIA scientific objectives, and we outline how this imager array will address key science issues, like the transition region and coronal waves or flare precursors, in coordination with other SDO experiments. We finally describe the real-time solar monitoring products that will be made available for space-weather forecasting applications. [less ▲]

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See detailLearning movement patterns in mobile networks: a generic method
François, Jean-Marc; Leduc, Guy ULg; Martin, Sylvain ULg

in European Wireless 2004 (2004, February)

Predicting terminals movements in mobile networks is useful for more than one reason, in particular for routing management. A way to do such prediction is to learn the movement patterns of mobile nodes ... [more ▼]

Predicting terminals movements in mobile networks is useful for more than one reason, in particular for routing management. A way to do such prediction is to learn the movement patterns of mobile nodes passing by an access router. In this paper, the information (e.g. layer 2 measurements) related to the different paths followed by mobiles are learned using a hidden Markov model. Simulations have been done using this method and show it can handle different layer~2 signals and collect statistical information when no such signal is available. Furthermore, the method works when no information is available and can be extended so as to guess the timing of the handoffs. [less ▲]

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See detailDesign of an implantable micropump
Smal, Olivier; Merken, Patrick; Croquet, Vincent et al

in Proceedings of the International Precision Assembly Seminar (2004, February)

The implantable programmable micropump is an interesting solution to treat chronic diseases such as diabetes with regular micro-injections of medicine. However, current applications of micropumps are ... [more ▼]

The implantable programmable micropump is an interesting solution to treat chronic diseases such as diabetes with regular micro-injections of medicine. However, current applications of micropumps are limited by their rather expensive cost. The challenge is therefore to develop a low cost alternative by reducing the number of parts and by simplifying the assembly. As the pump and its tank will be placed under the skin in order to increase comfort, such a system should be small and reliable. In this paper, we present the micropump we developed within the framework of the 4M-µ pump interuniversity project (Methods and Means for the Miniaturization of Machines). [less ▲]

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See detailDesign and test of a circular notch hinge
Merken, Patrick; Smal, Olivier; Debongnie, Jean-François ULg et al

in Proceedings of the International Precision Assembly Seminar (2004, February)

At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hing seems to be ... [more ▼]

At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hing seems to be very attractive through its many advantages. The major limitation is on the rotation angle. This paper presents a new simplified analytical model for the prediction of the maximum angular displacement and the angular stiffness of a notch hinge. To validate our model, an experimental set-up has been developed. [less ▲]

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See detailMise au point d'une méthode de détermination in vitro du taux de fermentation des fibres dans le gros intestin du porc
Boudry, Christelle ULg; Buldgen, André; Anciaux, Benoit et al

in 36èmes Journées de la Recherche Porcine (2004, February)

L’objectif des études synthétisées dans cette communication consiste à mettre au point une méthode in vitro, simple, fiable et respectueuse du bien-être animal, pour mesurer la fermentation des fibres ... [more ▼]

L’objectif des études synthétisées dans cette communication consiste à mettre au point une méthode in vitro, simple, fiable et respectueuse du bien-être animal, pour mesurer la fermentation des fibres dans le gros intestin du porc. Les travaux ont été réalisés en adaptant la méthode de BOISEN et FERNANDEZ à la pepsine-pancréatine pour simuler la digestion des aliments dans la première partie du tube digestif. La méthode d’incubation en seringues de MENKE et STEINGASS a ensuite été utilisée pour quantifier la production de gaz des résidus de la prédigestion. Les expériences, réalisées au moyen de porcs en croissance, ont porté sur la quantité et le mode de filtration des substrats prédigérés par la pepsine-pancréatine, l’identification d’un aliment de référence, la dilution des inoculi dans la solution tampon en seringues et la comparaison des fermentations, en utilisant comme inoculi des contenus d’intestin ou des matières fécales. Les résultats montrent que la répétabilité de la digestion in vitro par la pepsine-pancréatine est satisfaisante et que les quantités d’aliment incubées peuvent être augmentées par rapport à la méthode de référence. La filtration des résidus peut être réalisée sur creusets filtrants ou sur toile Nylon. La pulpe de betterave constitue un aliment témoin idéal. Après 24 h d’incubation, la production de gaz obtenue à partir d’inoculi fécaux dilués 20 fois dans la solution tampon est identique à celle enregistrée à partir d’inoculi intestinaux dilués 10 fois dans le même tampon. [less ▲]

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See detailENEAS: the European Network of Excellence in AsteroSeismology
Aerts, C.; Baglin, A.; Christensen-Dalsgaard, J. et al

in Favata, F.; Aigrain, S.; Wilson, A. (Eds.) Second Eddington Workshop: Stellar structure and habitable planet finding, 9 - 11 April 2003, Palermo, Italy (2004, January 01)

Asteroseismology is one of the major important science topics in astrophysics in the coming decade. Several recent breakthroughs have indeed been made in Europe in this field. The observational data will ... [more ▼]

Asteroseismology is one of the major important science topics in astrophysics in the coming decade. Several recent breakthroughs have indeed been made in Europe in this field. The observational data will improve significantly in the near future, as upgraded ground-based instruments are being built and two European asteroseismic space missions are planned for launch between 2005 and 2008. They will provide us for the first time with ultra-high-accuracy, high-temporal resoluton data from space for stars other than the Sun. A successful asteroseismic study involves many different steps, from state-of-the-art raw data treatment to theoretical physical modelling of the oscillation frequencies. Our network is set up to meet the needs of combining and exchanging the different expertises of the participating institutes, of training PhD students and of both training and exchanging post-doctoral researchers. This will guarantee the most fruitful and efficient exploitation of the very substantial investments that are being made in Europe in future observations of stellar oscillations, strengthening Europe's leading position in this research field. Also, it will be a test-bed for the development of efficient procedures for collaboration across the internet, involving a vast range of procedures and skills, as well as extensive common use of a broad variety of data. Furthermore, procedures will be incorporated for the joint training of students, which is an essential part of our project. [less ▲]

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See detailNon-adiabatic pulsations in delta Scuti stars
Moya, A.; Garrido, R.; Dupret, Marc-Antoine ULg

in Stellar Structure and Habitable Planet Finding (2004, January 01)

For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric ... [more ▼]

For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric observations. The same quantities can be also calculated from theoretical non-adiabatic pulsation models. We present here these theoretical results, which indicate that non-adiabatic quantities depend on the mixing length parameter alpha used to treat the convection in the standard Mixing Length Theory (MLT). This dependence can be used to test and to constrain, through multicolor observations, the way MLT describes convection in the outermost layers of the star. We will use the equilibrium models provided by the CESAM evolutionary code. The pulsational observables are calculated by using a non-adiabatic pulsation code developed by R. Garridon and A. Moya. In the evolutionary and pulsation codes, a complete reconstruction of the non-grey atmosphere (Kurucz models) is included. The interaction between pulsation and atmosphere, as described by Dupret et al. (2002), is also included in the code. [less ▲]

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See detailAdditional science potential for COROT
Weiss, W. W.; Aerts, C.; Aigrain, S. et al

in Favata, F.; Aigrain, S.; Wilson, A. (Eds.) Stellar Structure and Habitable Planet Finding (2004, January 01)

Space experiments which are aiming towards asteroseismology and the detection of exoplanets, like COROT or MOST, Eddington and Kepler, are designed to deliver high precision photometric data. Obviously ... [more ▼]

Space experiments which are aiming towards asteroseismology and the detection of exoplanets, like COROT or MOST, Eddington and Kepler, are designed to deliver high precision photometric data. Obviously, they can be used also for other purposes than the primary science goals and in addition many other targets can or will be automatically observed simultaneously with the primary targets. As a consequence, fascinating possibilities for additional (parallel, secondary) science projects emerge. For COROT a dedicated working group was thus established with the goal to contribute any useful information which may optimize the scientific output of the mission. [less ▲]

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See detailThe Photospheric Abundances of Active Binaries: First Results
Morel, Thierry ULg; Micela, G.; Favata, F. et al

in Stars as Suns : Activity, Evolution and Planets (2004, January 01)

The coronal abundances of chromospherically active binaries have come under close scrutiny in recent years thanks to several X-ray satellites such as XMM or Chandra. Unfortunately a detailed analysis of ... [more ▼]

The coronal abundances of chromospherically active binaries have come under close scrutiny in recent years thanks to several X-ray satellites such as XMM or Chandra. Unfortunately a detailed analysis of the chemical fractionation processes that are possibly operating between the photosphere and the corona is plagued by the lack of reliable and accurate photospheric abundance determinations. In particular a detailed investigation of the photospheric metal content seems worthwhile in the light of several studies that have questioned the customary use of photometric indices as effective temperature indicators in active binaries. We shall present our ongoing effort to determine in a self-consistent way accurate physical parameters and photospheric abundances for a large number of systems and discuss the implications of our results on their abundance patterns and evolutionary status. Preliminary results suggest that these systems are not as iron-deficient as found in previous studies and indicate an overabundance of several key elements (e.g. Na Mg Al Ca) with respect to the solar pattern. [less ▲]

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See detailPreliminary Results from the XMM Medium Deep Survey
Maraschi, L.; Tajer, M.; Trinchieri, G. et al

in Mújica, Raúl; Maiolino, Roberto (Eds.) Multiwavelength AGN Surveys, Proceedings of the Guillermo Haro Conference (2004, January 01)

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See detailMesoscopic model of intergranular cracks in low carbon steel during cooling of continuous casting
Castagne, S.; Pascon, Frédéric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Lamberigts, M. (Ed.) Proceedings of the 2nd international conference of thermomechanical processing of steels (TMP 2004) (2004)

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a ... [more ▼]

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a numerical approach for the modelling of these phenomena at the grain scale is proposed. Experiments allowing the identification of the model’s parameters are described. Finally, the first results obtained with the model are presented. [less ▲]

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See detailStudy of surface active properties and thermal behaviour of enzymatically prepared sugar esters
Blecker, Christophe ULg; Deroanne, Claude; Lognay, Georges ULg et al

in Proceedings "Cosm'ing 2004 : Cosmetic Ingredients and Biotechnology" (2004)

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See detailL'effet des polluants sur le comportement géomécanique des argiles: une approche généralisée
Schmitz, R. M.; Schroeder, Christian; Charlier, Robert ULg

in Journées Nationales de Géotechnique et de Géologie de l'Ingénieur (2004)

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See detailAn immunohistochemical study of canine nasal aspergillosis.
Peeters, Dominique ULg; day, M. J.; Moore, Peter et al

in Proceedings of The 14th Annual Congress of the ECVIM-CA (2004)

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See detailQTL analysis of the expression of the low-gossypol seed and high gossypol plant trait in the progeny of the Gossypium hirsutum x G. raimondii x G. sturtanium trispecific hybrid
Benbouza, H.; Lacape, M.; Courtois, B. et al

in Proceedings of the Beltwide cotton improvement conference (2004)

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See detailHow can intermodal transport support the logistical strategies of enterprises: a study on the opportunities and bottlenecks
Marchal, Jean ULg; Macharis, C.; Lundoluka, F. et al

in How can intermodal transport support the logistical strategies of enterprises: a study on the opportunities and bottlenecks (2004)

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See detailStaff development and e-tutors training
Banks, Sheena; Denis, Brigitte ULg; Fors, Uno et al

in Banks, Sheena; Goodyear, Peter; Hodgson, Vivien (Eds.) et al Networked learning 2004 : a research based conference on networked learning in higher education and lifelong learning : proceedings of the fourth international conference, Lancaster (2004)

This paper considers the rationale for the training and staff development of e-tutors. We then examine how this is implemented in practice through the presentation of case studies from three European ... [more ▼]

This paper considers the rationale for the training and staff development of e-tutors. We then examine how this is implemented in practice through the presentation of case studies from three European universities. Finally we analyse the differences and similarities of these case studies to exemplify some principles for training models and guidelines for training of e-tutors. We conclude that although it is possible to identify these principles of good practice, there is great flexibility and diversity of methods and approaches in the training and staff development of e-tutors. [less ▲]

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See detailUn manuscrit inédit des Mille et une nuits: à propos de l'exemplaire de l'université de Liège (ms. 2241)
Bauden, Frédéric ULg

in Chraïbi, Aboubakr (Ed.) Les Mille et une nuits en partage (2004)

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See detailAnalysis of the mechanisms of action of Mycosphaerella fijiensis toxins during the development of Black Leaf Streak disease.
Busogoro, J. P.; Etame, J. J.; Lognay, Georges ULg et al

in Mohan Jain, S.; Swennen, Rony (Eds.) Banana improvement: cellular, molecular biology, and induced mutations.Proceedings of a meeting held in Leuven, Belgium, 24-28 September 2001 (2004)

The goal of our programme is to understand the role of M. fijiensis toxins in Black Leaf Streak disease to facilitate early selection of banana genotypes resistant to the disease. Toxic effects induced by ... [more ▼]

The goal of our programme is to understand the role of M. fijiensis toxins in Black Leaf Streak disease to facilitate early selection of banana genotypes resistant to the disease. Toxic effects induced by crude extracts, as well as by purified juglone released by the pathogen in culture filtrates, were analysed on two reference cultivars of banana. Injection of the pathogen metabolites into banana leaves showed a light-dependent toxicity revealed by the development of necrosis and a rapid decrease of the relative vitality index determined from chlorophyll fluorescence measurements. We demonstrated that juglone, a purified metabolite of M. fijiensis, has a direct inhibitory effect on the electron transfer properties of purified banana chloroplasts. Regardless of the bioassay performed, the susceptibility of the two reference cultivars to this metabolite was correlated with their respective sensitivity to the pathogen infection. On the other hand, some preliminary data showed that juglone initiates oxidation of ascorbic acid, the most abundant antioxidant system in plants. On this base, we hypothesized that oxidative damage could be involved in the action of M. fijiensis toxins. [less ▲]

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See detailUtilité des biotechnologies de la reproduction pour la sélection des bovins laitiers
Colleau, J. J.; Fritz, S.; Druet, Tom ULg et al

in Renc. Rech. Ruminants, 2004, 11 (2004)

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See detailUn système d'indicateurs d'équité des systèmes éducatifs européens : un outil d'analyse des politiques d'éducation et de formation en Communauté française de Belgique
Nicaise, Julien; Straeten, Marie-Hélène; Baye, Ariane ULg et al

in Actes du troisième congrès des chercheurs en éducation (2004)

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See detailEcoles sanctuaires, écoles ghettos : quel rôle joue l'origine socioculturelle et ethnique dans les différences de performances entre établissements ?
Monseur, Christian ULg; Lafontaine, Dominique ULg

in Actes du 3e congrès des chercheurs en éducation, Bruxelles, 16-17 mars 2004 (2004)

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See detailL’architecture comme représentation de la justice pénale
Tieleman, David ULg

in GAMBARDELLA, Carmine; MARTUSCIELLO, Sabina (Eds.) Le Vie deai Mercanti : rappresentazione come governo della modificazione (2004)

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See detailThermo-elasto-plastic modeling of the behaviour of metals submitted to finite strains. A coupled thermo-mechanical approach
Ponthot, Jean-Philippe ULg; Adam, L.

in Proceedings of ENIEF 2004, XIV Congress on numerical methods and their applications (2004)

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See detailPositive and negative aspects of « Sport + Studies Programmes » organized at secondary school level, perceived by athletes and their classmates
Cloes, Marc ULg; Schelings, Virginie; Ledent, Maryse et al

in Gomez, Varera; Gonzalez, Valeiro; Sanchez, Molina (Eds.) Preparacion professional y necesidades socials (Educacion fisica, deporte, ocio, tercera edad, salud...). Proceedings of the AIESEP International Congress (2004)

In many sports, top level athletes have experienced years of hard practice. Training must be intensive and abide to high quality criteria. Today, promising teenagers are enrolled in sport programmes ... [more ▼]

In many sports, top level athletes have experienced years of hard practice. Training must be intensive and abide to high quality criteria. Today, promising teenagers are enrolled in sport programmes. However, the success of sport careers is so hazardous that it is necessary to guarantee the best school preparation to youths following their way to top level sport ... [less ▲]

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See detailNash equilibria and reinforcement learning for active decision maker modelling in power markets
Krause, Thilo; Andersson, Goran; Ernst, Damien ULg et al

in Proceedings of the 6th IAEE European Conference: Modelling in Energy Economics and Policy (2004)

In this paper, we study the behavior of power suppliers who submit their bids to the market place in order to maximize their payoffs. The market clearing mechanism is based on the locational marginal ... [more ▼]

In this paper, we study the behavior of power suppliers who submit their bids to the market place in order to maximize their payoffs. The market clearing mechanism is based on the locational marginal price. To study the interaction of the power suppliers, we rely on two different approaches and compare the results obtained. One approach consists of computing the Nash equilibria of the market, and the other models each player’s behavior by using reinforcement learning algorithms. Simulations are carried out on a five node power system. [less ▲]

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