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See detailWalking on the Wild Side of Modernism
Delville, Michel ULg

in Den Tandt, Christophe (Ed.) Reading Without Maps (2005, October 21)

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See detailComparison of West African Dwarf (WAD) sheep and F1 crossed West African Long Legged (WALL) rams with WAD ewes in Benin : Growth and Survival traits
Gbangboche, A.; Abiola, F. A.; Leroy, Pascal ULg

in The Global Food & Product Chain— Dynamics, Innovations, Conflicts, Strategies Deutscher Tropentag 2005 (2005, October 11)

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See detailConvection and interfacial mass exchange
Colinet, P.; Legros, Jean-Claude; Dauby, Pierre ULg et al

in ESA Special Publication (2005, October 01)

Mass-exchange through fluid interfaces is ubiquitous in many natural and industrial processes. Yet even basic phase-change processes such as evaporation of a pure liquid are not fully understood, in ... [more ▼]

Mass-exchange through fluid interfaces is ubiquitous in many natural and industrial processes. Yet even basic phase-change processes such as evaporation of a pure liquid are not fully understood, in particular when coupled with fluid motions in the vicinity of the phase-change interface, or with microscopic physical phenomena in the vicinity of a triple line (where the interface meets a solid). Nowadays, many industries recognise that this lack of fundamental knowledge is hindering the optimisation of existing processes. Their modelling tools are too dependent on empirical correlations with a limited - and often unknown - range of applicability. In addition to the intrinsic multiscale nature of the phenomena involved in typical industrial processes linked to interfacial mass exchange, their study is highly multi-disciplinary, involving tools and techniques belonging to physical chemistry, chemical engineering, fluid dynamics, non-linear physics, non-equilibrium thermodynamics, chemistry and statistical physics. From the experimental point of view, microgravity offers a unique environment to obtain valuable data on phase-change processes, greatly reducing the influence of body forces and allowing the detailed and accurate study of interfacial dynamics. In turn, such improved understanding leads to optimisation of industrial processes and devices involving phase-change, both for space and ground applications. [less ▲]

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See detailEntropy-based knowledge spreading and application to mobility prediction
François, Jean-Marc; Leduc, Guy ULg

in ACM International conference on Emerging Network Experiments and Technologies (2005, October)

The low quality of service provided by wireless networks does not facilitate the setup of long-awaited services, such as video conversations. In a cellular network, handoffs are an important cause of ... [more ▼]

The low quality of service provided by wireless networks does not facilitate the setup of long-awaited services, such as video conversations. In a cellular network, handoffs are an important cause of packet losses and delay jitter. These problems can be mitigated if proactive measures are taken. This requires each cell to guess the next handoff of each mobile terminal, a problem known as mobility prediction. This prediction can occur thanks to some clues (such as signal strength measurements) giving information about the terminals motion. For example, a clue that locates on which road a mobile is moving is likely to be interesting for all the prediction-enabled cells along that road ---and should therefore be sent to them. This paper proposes a new method aimed at selecting the most relevant clues and finding where to propagate those clues so as to optimize mobility predictions. The pertinence of a clue is measured using information theory and by means of decision trees. This pertinence estimation is exchanged between the cells and allows to build a"relevance map" that helps determine where clues should be sent. It is adapted to the characteristics of wireless terminals such as low bandwidth and processing power. [less ▲]

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See detailTemporalités et territorialités dans la dynamique des réseaux, l'exemple du programme régional de la santé des jeunes
Absil, Gaëtan ULg; Vandoorne, Chantal ULg; Demarteau, Michel

in Territoire, bien-être et inclusion sociale - Résumés des communications (2005, October)

Summary : Territories and times are significant factors in networks management and efficacy. Tools should be designed to survey if networking is appropriate for a project in a particular setting.

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See detailProduction de xérogels de carbone hyperporeux par séchage convectif
Léonard, Angélique ULg; Job, Nathalie ULg; Jomaa, Wahbi et al

in Azzaro-Pantel, Catherine; Bertrand, Joel; Cabassub, Michel (Eds.) et al Récents progrès en génie des procédés N° 92: 10ème Congrès de la SFGP, Toulouse 2005. Le génie des procédés vers de nouveaux espaces (2005, October)

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See detailGeneralized shape optimization using XFEM and Level Set methods
Duysinx, Pierre ULg; Van Miegroet, Laurent ULg; jacobs, Thibaut et al

in Bendsoe, M.-P.; Olhoff, N.; Sigmund, O. (Eds.) Proceedings of Topopt SYMP2005, IUTAM Symposium. Topological Design Optimization of Structures, Machines and Materials. Status and Perspectives (2005, October)

This paper presents an intermediate approach between parametric shape optimization and topology optimization. It is based on using the recent Level Set description of the geometry and the novel eXtended ... [more ▼]

This paper presents an intermediate approach between parametric shape optimization and topology optimization. It is based on using the recent Level Set description of the geometry and the novel eXtended Finite Element Method (XFEM). The method takes benefit of the fixed mesh work using X-FEM and of the curves smoothness of the Level Set description. Design variables are shape parameters of basic geometric features. The number of design variables of this formulation is small whereas various global and local constraints can be considered. The Level Set description allows to modify the connectivity of the structure as geometric features can merge or separate from each other. However no new entity can be introduced. A central problem that is investigated here is the sensitivity analysis and the way it can be carried out efficiently. Numerical applications revisit the classical elliptical hole benchmark from shape optimization. [less ▲]

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See detailA micromachined electrostatically suspended gyroscope with digital for feedback
Damrongsak, B; Kraft, Michael ULg

in Proceedings of "IEEE Sensor Conference : USA - Octobre 2005" (2005, October)

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See detailDynamic holography for the space qualification of large reflectors
Thizy, Cédric ULg; Stockman, Yvan ULg; Doyle, D. et al

in Optical Fabrication, Testing, and Metrology II (2005, October)

The next generation of infrared - sub mm space telescopes requires reflectors with large dimensions, high quality and, according to weight issues, are based on composite or new materials technology. The ... [more ▼]

The next generation of infrared - sub mm space telescopes requires reflectors with large dimensions, high quality and, according to weight issues, are based on composite or new materials technology. The challenging tasks of on-ground testing are to achieve the required accuracy in the measurement of these reflectors shape and antenna structures and to verify their performance under simulated space conditions (vacuum, low-high temperatures). A holographic camera for the verification and validation of this type of reflector in a space environment is presented. A diffuser is implemented to measure the deformations of reflective surfaces in a more flexible way. The system has been made compatible with the vacuum conditions. Some elements of the holographic camera (camera lenses, CCD, crystal, optical fibre) have been adapted and tested under vacuum. The metrological certification of the whole system is realised by the measurement of a parabolic CFRP reflector with a 1.1 meter diameter. The results are compared to the one achieved with a high spatial resolution IR interferometer on the same reflector in laboratory conditions and under thermal vacuum conditions. This later test consists in measuring the deformations of the reflector between an initial state at a selected temperature and a final state at another temperature. The comparison between the high spatial resolution IR interferometer and this dynamic holographic method showed very good qualitative and quantitative agreement between the techniques, thus verifying the potential of this new Holographic approach. [less ▲]

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See detailDiagnosis of obstructive sleep apnoea and hypopnoea syndrome based on automatic analysis of mandibular movements
Senny, Frédéric ULg; Destiné, Jacques ULg; Ansay, Pierre et al

in Proceedings of the 1st WASM Congress (2005, October)

Our study showed the potential of a surrogate of the oesophageal pressure, the jaw motion, and a dedicated automatic analysis to diagnose the obstructive sleep apnoea and hypopnoea syndrome (OSAHS ... [more ▼]

Our study showed the potential of a surrogate of the oesophageal pressure, the jaw motion, and a dedicated automatic analysis to diagnose the obstructive sleep apnoea and hypopnoea syndrome (OSAHS). Twentyfour patients were recorded in hospital settings and the jaw motion of fifteen of them was also recorded at home with an ambulatory device. The apnoea and hypopnoea index (AHI) of the gold standard, AHI_PSG, and the two AHI from the automatic analysis of the jaw motion, AHI_H (hospital) and AHI_A (ambulatory), were compared : AHI_PSG Vs AHI_H showed good correlation (r = 0.97) and under-estimation (slope p = 0.76). AHI_A Vs AHI_H revealed good reliability with r = 0.98 and slope p = 0.99. Finally, AHI_PSG Vs AHI_A showed very good accuracy of the diagnosis with sensitivity of 90% and specificity of 100%. [less ▲]

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See detailRecherches récentes sur l'utilisation des Degrés de Certitude Recherches récentes sur l'utilisation des Degrés de Certitude : Directions de recherches dans le calcul des notes liant exactitude et réalisme
Castaigne, Jean-Loup ULg

in Actes du 18ème colloque international de l'ADMEE : Comment évaluer ? Outils, dispositifs et acteurs (2005, October)

Ebel (1965) définit les Degrés de Certitude comme “un mode de réponse spécial aux questions d’un test objectif et un mode spécial de cotation de ces réponses. En bref, le sujet doit indiquer non seulement ... [more ▼]

Ebel (1965) définit les Degrés de Certitude comme “un mode de réponse spécial aux questions d’un test objectif et un mode spécial de cotation de ces réponses. En bref, le sujet doit indiquer non seulement ce qu’il croit être la réponse correcte à une question, mais aussi sa certitude dans l’exactitude de sa réponse. Au moment de la cotation, le sujet reçoit plus de points pour une réponse correcte avec certitude que pour une réponse accompagnée d’un doute” (cité par Leclercq, 1983). Cette définition restreint l’utilisation des degrés de certitude d’une part aux tests par QCM alors qu’ils sont applicables à d’autres méthodes d’évaluation et d’autre part à une seule méthode de recueil des informations. Les degrés de certitude pouvant être mis au service de plusieurs objectifs, nous proposons une réflexion aux enseignants qui désirent les utiliser. Nous envisagerons plusieurs méthodes possibles pour recueillir les degrés de certitude. Pour chaque méthode, des avantages et des inconvénients sont mis en évidence et des pistes d’amélioration sont envisagées. Les trois catégories de méthodes que nous proposons sont basées sur le lien entre le barème associant les degrés de certitude et le score au test. 1. Les barèmes liés à chaque question. Lorsque l’on cote les réponses de l’étudiant, il reçoit plus de points pour une réponse correcte donnée avec une certitude plus élevée qu’une réponse correcte donnée avec une certitude plus basse. 2. Les barèmes liés au test. On calcule le score d’exactitude de l’étudiant sur base d’un tarif pour les réponses correctes, les réponses incorrectes et les omissions. Ensuite, sur base de calcul d’indices métacognitifs portant sur l’ensemble des questions, on ajoute des « points métacognitifs ». 3. Pas de barème. On calcule le score d’exactitude de l’étudiant uniquement sur base d’un tarif pour les réponses correctes, les réponses incorrectes et les omissions. Les degrés de certitude n’ont plus de valeur certificative mais formative pour l’étudiant et informative pour l’enseignant. Nous illustrerons notre démarche à partir d’un cas concret d’enseignement à distance sur les règles de l’orthographe et la communication utilisant Au sein de chacune de ces trois catégories, plusieurs options sont envisagées afin de rencontrer notre objectif : l’émission sincère de la certitude que l’étudiant associe à sa réponse. [less ▲]

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See detailApplications of an interior point method based optimal power flow
Capitanescu, Florin ULg; Glavic, Mevludin; Wehenkel, Louis ULg

in CEE 05 conference (2005, October)

This paper tackles the complex problem of an Optimal Power Flow (OPF) by the Interior Point Method (IPM). Two interior point algorithms are presented and compared, namely the pure primal-dual and the ... [more ▼]

This paper tackles the complex problem of an Optimal Power Flow (OPF) by the Interior Point Method (IPM). Two interior point algorithms are presented and compared, namely the pure primal-dual and the predictor-corrector respectively. Among various OPF objectives, emphasis is put on two classical ones: the maximization of power system loadability and the minimization of the amount of load curtailment. Illustrative examples on three test systems of 60, 118 and 300 buses are provided. [less ▲]

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See detailExperience with the multiple centrality corrections interior point algorithm for optimal power flow
Capitanescu, Florin ULg; Glavic, Mevludin; Wehenkel, Louis ULg

in CEE 05 conference (2005, October)

This paper analyzes the ability of the Multiple Centrality Corrections (MCC) interior point algorithm to solve various classical optimal power flow (OPF) variants, namely: the minimization of generation ... [more ▼]

This paper analyzes the ability of the Multiple Centrality Corrections (MCC) interior point algorithm to solve various classical optimal power flow (OPF) variants, namely: the minimization of generation cost, the minimization of active power losses, the maximization of power system loadability and the minimization of the amount of load curtailment. The performances of the MCC approach are assessed with respect to the predictor-corrector algorithm, which is widely recognized as the best interior point method based optimizer to date. Illustrative examples on three test systems up to 300 buses are provided. [less ▲]

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See detailComparing traffic engineering objective functions
Balon, Simon ULg; Skivée, Fabian; Leduc, Guy ULg

in CoNext 2005 - Student Workshop (2005, October)

We compare and evaluate how well-known and novel network-wide objective functions for Traffic Engineering (TE) algorithms fulfil TE requirements. To compare the objective functions we model the TE problem ... [more ▼]

We compare and evaluate how well-known and novel network-wide objective functions for Traffic Engineering (TE) algorithms fulfil TE requirements. To compare the objective functions we model the TE problem as a linear program and solve it to optimality, thus finding for each objective function the best possible target of any heuristic TE algorithm. Our first results suggest that they can give quite different results. [less ▲]

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See detailMicrocapsules/microparticles loaded with biologically active molecules for medicine
Markvicheva, E; Selina, O; Stashevskaya, K et al

in Proceedin of European Congress on Chemical Engineering (2005, September 25)

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See detailLe froment d'hiver
Vancutsem, Françoise ULg; Couvreur, Luc; Bodson, Bernard ULg et al

in Livre Blanc: Céréales - Gembloux - Informations avant les semis (2005, September 08)

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See detailEscourgeon et Orge d'hiver fourragers
Herman, Jean-Luc; Monfort, Bruno; Couvreur, Luc et al

in Livre Blanc: Céréales - Gembloux - Informations avant les semis (2005, September 08)

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See detailLa qualité des froments d'hiver en 2005?
Sinnaeve, Geoges; Lenartz, J.; Herman, Jean-Luc et al

in Livre Blanc: Céréales - Gembloux - Informations avant les semis (2005, September 08)

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See detailAn attempt to create power line anti-galloping device with hysteretic type energy dissipation
Vinogradov, Alexander; Platonova, Irina; Akuratov, Andrei et al

in Proceedings of the 6th International Conference on Cable Dynamics (2005, September)

A new concept of anti-galloping device (TDD) based on hysteretic type damper is detailed.

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See detailHistochemical and immunohistochemical characterization of canine nasopharyngeal lymphoid tissue
Billen, Frédéric ULg; Peeters, Dominique ULg; Dehard, Sandrine ULg et al

in 15th ESVIM Meeting - Glasgow - Ecosse - Septembre 2005 (2005, September)

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See detailSurprisingly complicated dynamics of a SDOF linear oscillator coupled to a nonlinear attachment
Lee, Young Sup; Kerschen, Gaëtan ULg; Vakakis, Alexander F. et al

in ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Long Beach, 2005 (2005, September)

We study the dynamics of a two-degree-of-freedom nonlinear system consisting of a linear oscillator with an essentially nonlinear attachment. For the undamped system, we perform a numerical study based on ... [more ▼]

We study the dynamics of a two-degree-of-freedom nonlinear system consisting of a linear oscillator with an essentially nonlinear attachment. For the undamped system, we perform a numerical study based on non-smooth temporal transformations to determine its periodic solutions in a frequency–energy plot. It turns out that there is a sequence of periodic solutions bifurcating from the main backbone curve of the plot. We then study analytically the periodic orbits of the undamped system using the complexification / averaging technique in order to determine the frequency contents of the various branches of solutions, and to understand the types of oscillation performed by the system at the different regimes of the motion. The transient responses of the weakly damped system are then examined, and numerical wavelet transforms are used to study the time evolutions of their harmonic components. We show that the structure of periodic orbits of the undamped system greatly influences the damped dynamics, as it causes complicated transitions between modes in the damped transient motion. In addition, there is the possibility of strong passive energy transfer from the linear oscillator to the nonlinear attachment if certain periodic orbits of the undamped dynamics are excited by the initial conditions. [less ▲]

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See detailTriggering mechanisms of limit cycle oscillations in a 2DOF wing flutter model
Lee, Young S.; Vakakis, Alexander F.; Bergman, Lawrence A. et al

in ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Long Beach, 2005 (2005, September)

We show numerically that the triggering mechanisms of limit cycle oscillations (LCOs) due to aeroelastic instability are composed of a series of resonance captures. We consider a two degree-of-freedom ... [more ▼]

We show numerically that the triggering mechanisms of limit cycle oscillations (LCOs) due to aeroelastic instability are composed of a series of resonance captures. We consider a two degree-of-freedom (DOF) wing model with cubic nonlinear stiffnesses in the support, assuming quasi-steady aerodynamics and subsonic flow around the wing. Then, we establish the slow flow dynamics model, using the complexification / averaging technique and considering three frequency components; i.e., the two linear natural frequencies corresponding to heave and pitch and the superharmonic component which appears as three times the pitch frequency. It turns out that the LCO triggering mechanisms consist of mainly three stages: (i) transient resonance capture (TRC); (ii) escape; and (iii) permanent resonance capture (PRC). We examine the characteristics of each stage by way of time response, wavelet transform, phase plane, and instantaneous energy. [less ▲]

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See detailDynamic analysis of the nonlinear behavior of MEMS using the finite element formulation
Rochus, Véronique ULg; Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Long Beach, 2005 (2005, September)

The dynamic response of a mass-spring model of electrostatically actuated MEMS is analyzed when a voltage step is applied. The dynamics of a clamped-clamped beam representing a micro-bridge system are ... [more ▼]

The dynamic response of a mass-spring model of electrostatically actuated MEMS is analyzed when a voltage step is applied. The dynamics of a clamped-clamped beam representing a micro-bridge system are also considered. To model and simulate the strong coupling between the electric and mechanical fields, a general finite element program has been developed based on a new monolithic formulation. The methodology proposed in this program does not require any iterative numerical scheme based on separate electrostatic and mechanical solvers, respectively. [less ▲]

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See detailWhole body barometric plethysmography measurements in dogs with brachycephalic airway obstruction syndrome : preliminary results
Bernaerts, Frederique ULg; Talavera, J.; Le Garrérès, A. et al

in 15th ESVIM Meeting - Glasgow - Ecosse - Septembre 2005 (2005, September)

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See detailIrreversible passive TEF in the damped response of coupled oscillators with nonlinearity
Kerschen, Gaëtan ULg; Lee, Young S.; Vakakis, Alexander F. et al

in ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Long Beach, 2005 (2005, September)

We study, numerically and analytically the dynamics of passive energy transfer from a damped linear oscillator to an essentially nonlinear end attachment. This transfer is caused either by fundamental or ... [more ▼]

We study, numerically and analytically the dynamics of passive energy transfer from a damped linear oscillator to an essentially nonlinear end attachment. This transfer is caused either by fundamental or subharmonic resonance capture, and in some cases is initiated by nonlinear beat phenomena. It is shown that, due to the essential nonlinearity, the end attachment is capable of passively absorbing broadband energy both at high and low frequencies, acting, in essence, as a passive broadband boundary controller. Complicated transitions in the damped dynamics can be interpreted based on the topological structure and bifurcations of the periodic solutions of the underlying undamped system. Moreover, complex resonance capture cascades are numerically encountered when we increase the number of degrees of freedom of the system. The grounded, essentially nonlinear end attachment discussed in this work can find application in numerous practical settings, including vibration and shock isolation of structures, seismic isolation, flutter suppression and packaging. [less ▲]

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See detailReactivity of precious metal and transition metal oxide catalysts towards the total oxidation of volatile organic compounds containing nitrogen or sulfur atom (N-VOCs or S-VOCs)
Cellier, Caroline; Ruaux, V.; Lahousse, C. et al

in Catalytic Combustion, volume 2 (2005, September)

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See detailA Quasi-One Dimensional Model for Axial Compressors
Adam, Olivier; Léonard, Olivier ULg

in Proceedings od the 17th ISABE Conference (2005, September)

The object of the present paper is to present a fast and reliable CFD tool that is able to simulate stationary and transient operations of multistage axial compressors. The computational domain is the ... [more ▼]

The object of the present paper is to present a fast and reliable CFD tool that is able to simulate stationary and transient operations of multistage axial compressors. The computational domain is the compressor flow path, using a row-by-row, quasi-one-dimensional representation of the machine at mid-span. This analysis tool is based on an adapted version of the Euler equations solved by a time-marching, finite-volume method. The basic Euler equations have been extended by including source terms expressing the blade-flow interactions. The source terms are determined using the velocity triangles for each blade row, at mid-span. The losses and deviations undergone by the fluid in each blade row are supplied by correlations. The resulting flow solver is a performance prediction tool based only on compressor geometry. It offers the possibility of exploring the entire characteristic map of a compressor before its construction. Its efficiency in terms of CPU time makes it possible to use it as a fast design tool by coupling it to an optimization algorithm. In this paper, this CFD tool (called Quads hereafter) has been applied to two test-cases. Calculated characteristic curves are presented and compared to experimental ones. A correlation tuning process is described for an undocumented family of blade profiles. [less ▲]

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See detailNeutering : can obesity be avoided ?
Jeusette, Isabelle; Nguyen, Patrick; Diez, Marianne ULg

in Hurley, Karyl; Rutgers, Caroline (Eds.) Proceedings of the 15th ECVIM-CA Congress (2005, September)

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See detailMulti-Objective Optimization of a Fan Blade by Coupling a Genetic Algorithm and a Parametric Flow Solver
Kelner, Vincent ULg; Grondin, Gilles; Léonard, Olivier ULg et al

in Proceedings of EUROGEN'05 (2005, September)

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See detailValorization of olive mill wastewater by the yeast Yarrowia lipolytica.
Araújo, C.; Aguedo, Mario ULg; Gomes, N. et al

in Poceedings of the 9th International Chemical Engineering Conference (2005, September)

The aim of this work was to study the ability of two different strains of the yeast Yarrowia lipolytica to grow on Olive Mill Wastewater (OMW) and their potential to produce high-value products such as ... [more ▼]

The aim of this work was to study the ability of two different strains of the yeast Yarrowia lipolytica to grow on Olive Mill Wastewater (OMW) and their potential to produce high-value products such as lipases. Factors affecting cellular growth and OMW degradation were studied, such as nitrogen supplementation, cells concentration and surfactant addition. Both strains used were able to grow in an OMW with a COD of 19 g/L and total phenols concentration of around 800 mg/L. The strain W29 presented the highest potential for extracellular lipase production from OMW. Lipase productivity was improved by the medium supplementation with ammonium sulphate up to 6 g/L, leading to 80 % of COD degradation and 70 % of total phenols reduction. The surfactant Tween 80 enhanced cell growth and COD degradation, but had no significant effect on lipase productivity. The results evidenced that the conditions that favoured lipase production differ from the conditions that improve COD removal from OMW. [less ▲]

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See detailPassive solar buildings : development and evaluation of a model-based optimal controller through experimentation and simulation.
Andre, Philippe ULg; Kummert, M.

in Proceedings of the International conference Energy efficient technologies in indoor environment (2005, September)

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function ... [more ▼]

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function" paradigm. The experimental facilities did not allow a direct experimental comparison by using two identical buildings. The controllers were implemented alternatively in one building and a performance comparison was obtained in two ways: first by identifying short periods that have similar driving variables (weather and building occupancy) and comparing the experimental obtained in both cases. The second method mixes experiments and simulation using a well-tuned model of the building and its occupants. This paper discusses the results obtained using both methods and shows that both methods give consistent estimates of the difference between controllers, while the second method allows to extrapolate useful information from the limited data available. In a second evaluation step the controller is applied to a multizone building, and a detailed model is used for the HVAC system. The model-based control algorithm is not modified. It is based on a simplified internal model. It is shown that the optimal controller's performance varies strongly with the zone that is considered and the reference zone that is used. However, it is never worse than the performance of a reference controller. The global performance at the building level depends on the selected reference zone and on the building sensitivity to overheating. [less ▲]

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See detailProcollagen type-III aminoterminal peptide in serum and bronchoalveolar lavage fluid in dogs with chronic bronchopneumopathies – preliminary results
Schuller, S.; Talavera, J.; Jespers, P. et al

in 15th ESVIM Meeting - Glasgow - Ecosse - Septembre 2005 (2005, September)

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See detailAbout the use of simulation models and of functional tests in commissioning of HVAC systems.
Adam, Ch.; Andre, Philippe ULg; Aparecida, Cl. et al

in Proceedings of the International conference Energy efficient technologies in indoor environment (2005, September)

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See detailThe effect of continuous galvanizing thermal cycle on the microstructure and mechanical properties of two multiphase TRIP-assisted steels
Mertens, Anne ULg; McDermid, Joseph R.

in Proceedings of the MS&T'05 Conference (2005, September)

Multiphase TRIP assisted-steels are particularly attractive for the automotive industry, as they exhibit an exceptional strength-ductility balance which is attained through the combination of a complex ... [more ▼]

Multiphase TRIP assisted-steels are particularly attractive for the automotive industry, as they exhibit an exceptional strength-ductility balance which is attained through the combination of a complex microstructure and of a TRIP effect, i.e. the mechanically induced transformation of metastable retained austenite. This multiphase microstructure - and particularly the retention of metastable austenite - is obtained through the combination of appropriate chemistry and processing conditions, i.e an intercritical annealing followed by an isothermal hold in the temperature range for bainite formation. It has been established that this second step is important in controlling austenite retention and hence the mechanical properties. In the present work, the effect of heat treatment cycles compatible with the continuous hot dip galvanizing process, namely a high bainitic dwell temperature, on the microstructure and mechanical properties of two multiphase TRIP-assisted steel grades - one Si-alloyed grade and one mixed Si-Al grade - has been studied. It was shown that bainite formation in the Si-alloyed grade was too slow to bring about the retention of a significant amount of austenite down to room temperature. The mixed Al-Si grade, on the other hand, exhibited faster bainite formation kinetics under heat treatment conditions compatible with the CGL process, such that it is possible to retain a significant amount of austenite. The partial substitution of silicon by aluminum appears thus a promising path for the production of galvanized TRIP-assisted steels. [less ▲]

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See detailDirections de recherches dans le calcul des notes liant exactitude et réalisme: illustration à travers une démarche en formation à distance
Castaigne, Jean-Loup ULg

in Actes du 22e congrès de l'association internationale de pédagogie universitaire (AIPU) : L'enseignement supérieur du {XXIe} siècle : de nouveaux défis à relever. (2005, September)

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See detailA one-dimensional electrostatic actuator for tuning optical cavities on atom chips
Gollasch, Carsten O.; Moktadir, Zakaria; Lewis, Gareth Neil et al

in 16th European Workshop on Micromechanics. [MME 2005] (2005, September)

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See detailTOPACMER : indices de participation d'étudiants à un cours dans l'Enseignement Supérieur
Leclercq, Dieudonné ULg; Glowacki, Jessica

in Rege-Colet, Nicole (Ed.) Actes du Colloque AIPU 2005 : L'enseignement supérieur du XXIe siècle : de nouveaux défis à relever (CD Rom) (2005, September)

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See detailComparison of bronchoalveolar lavage cytospins ans smears in small animals
Dehard, Sandrine ULg; Bernaerts, Frederique ULg; Peeters, Dominique ULg et al

in 15th ESVIM Meeting - Glasgow - UK - 2005 (2005, September)

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See detailElectrostatic suspension control for micromachined inertial sensors employing a levitated-disk proof mass
Damrongsak, Badin; Kraft, Michaël ULg

in 16th European Workshop on Micromechanics. [MME 2005] (2005, September)

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See detailHistochemical and immunohistochemical characterisation of canine nasopharyngeal lymphoid tissue
Billen, Frédéric ULg; Peeters, Dominique ULg; Dehard, Sandrine ULg et al

in Proceedings of the 15th ECVIM-CA Congress (1-3/09/2005), Glasgow, Scotland (2005, September)

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See detailFabrication of gold wires for atom chips by electrochemical deposition: a comparative study
Lewis, Gareth; Moktadir, Zakaria; Gollasch, Carsten O. et al

in 16th European Workshop on Micromechanics. [MME 2005] (2005, September)

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See detailForce feedback linearization for higher-order electromechanical sigma--delta modulators
Dong, Yufeng; Kraft, Michaël ULg; Redman-White, William

in 16th European Workshop on Micromechanics. [MME 2005] (2005, September)

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See detailInnovative designs for the imaging suite on Solar Orbiter
Auchere, Frederic; Song, Xueyen; Rouesnel, Frederic et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2005, August 01)

Orbiting around the Sun on an inclined orbit with a 0.2 UA perihelion, the Solar Orbiter probe will provide high resolution views of the Sun from various angles unattainable from Earth. Together with a ... [more ▼]

Orbiting around the Sun on an inclined orbit with a 0.2 UA perihelion, the Solar Orbiter probe will provide high resolution views of the Sun from various angles unattainable from Earth. Together with a set of high resolution imagers, the Full Sun Imager is part of the EUV Imaging suite of the Solar Orbiter mission. The mission's ambitious characteristics draw severe constraints on the design of these instruments. We present a photometrically efficient, compact, and lightweight design for the Full Sun Imager. With a 5 degrees field of view, this telescope will be able to see the global solar coronal structure from high viewing angles. Thermal solutions reducing the maximum power trapped in the High Resolution Imagers are also proposed. [less ▲]

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See detailThe four-quadrant ZOG and annular groove phase mask coronagraphs
Mawet, Dimitri; Riaud, Pierre ULg; Absil, Olivier ULg et al

in Coulter, Daniel R (Ed.) Techniques and Instrumentation for Detection of Exoplanets II (2005, August 01)

Phase mask coronagraphy is a technique aiming at accommodating both high dynamic and high angular resolution imaging of faint sources around bright objects such as exo-planets orbiting their parent stars ... [more ▼]

Phase mask coronagraphy is a technique aiming at accommodating both high dynamic and high angular resolution imaging of faint sources around bright objects such as exo-planets orbiting their parent stars or host galaxies around Active Galactic Nuclei. We present two new phase mask coronagraphs implemented with subwavelength diffractive optical elements consisting of optimized surface-relief gratings. The first one is an evolution of the Four Quadrant Phase Mask coronagraph, which resolves the Ï phase shift chromaticity problem: the Four Quadrant Zeroth Order Grating (4QZOG). The second one is a totally new design consisting of an optical vortex induced by a space-variant grating: the Annular Groove Phase Mask (AGPM) coronagraph is fully symmetric and free from any "shaded zones". Some manufacturing hints are given. [less ▲]

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See detailUltraviolet Spectroscopy of Saturn: Determination of Auroral characteristics with FUSE, STIS and UVIS Spectra
Gustin, Jacques ULg; Gérard, Jean-Claude ULg; Feldman, P. D. et al

in Bulletin of the American Astronomical Society (2005, August 01)

Ultraviolet (UV) lines from Saturn's aurorae are emitted following inelastic collisions between energetic electrons and H[SUB]2[/SUB] molecules. De-excitation by radiative process lead to Far Ultraviolet ... [more ▼]

Ultraviolet (UV) lines from Saturn's aurorae are emitted following inelastic collisions between energetic electrons and H[SUB]2[/SUB] molecules. De-excitation by radiative process lead to Far Ultraviolet (FUV) and Extreme Ultraviolet (EUV) emissions in the 750-1750 Ã spectral window. Low resolution spectra ( 12 Ã ) obtained with HST/STIS in the 900-1700 Ã window are employed to derive the absorption of the auroral photons by hydrocarbons (mainly methane) and depth of the auroral energy deposition. Determination of H[SUB]2[/SUB] temperature and overlying H[SUB]2[/SUB] column is achieved by analyzing spectra obtained with the FUSE instrument ( 0.2 Ã resolution with the LWRS aperture in the 900-1200 Ã spectral window). Below 1100 Ã , transitions connecting to the v" = 0 and 1 levels of ground-state H[SUB]2[/SUB] are partially or totally absorbed by ambient H[SUB]2[/SUB] (self-absorption). Comparisons between observed and synthetic spectra allow to derive the gaz temperature and the overlying H[SUB]2[/SUB] column, which is an indicator of the depth of the aurora, hence of the energy of the precipitated electrons. Auroral spectra of Saturn at 12 Ã resolution were also obtained with Cassini's Ultraviolet Imaging Spectrograph (UVIS), both in the EUV and FUV spectral bands. While the spectral resolution of UVIS is too low to estimate temperatures, the coverage of the entire UV domain allows to determine the energy of precipitated particles through the quantification of the methane and molecular hydrogen columns. Results from observations with these three instruments are presented and compared in order to characterize the auroral atmosphere and auroral electrons precipitated from Saturn's magnetosphere. [less ▲]

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See detailOxygen influence on the ß-oxidative metabolism of methyl ricinoleate for lactones production by the yeast Yarrowia lipolytica
Aguedo, Mario ULg

in Proceedings of the 2nd Mercosur Congress on Chemical Engineering – ENPROMER and 4th Mercosur Congress on Process Systems Engineering (2005, August)

The yeast Yarrowia lipolytica is able to carry out the peroxisomal b-oxidative catabolism of methyl ricinoleate, a process leading notably to the production of g-decalactone, a high-value aroma compound ... [more ▼]

The yeast Yarrowia lipolytica is able to carry out the peroxisomal b-oxidative catabolism of methyl ricinoleate, a process leading notably to the production of g-decalactone, a high-value aroma compound. In fact, this metabolic pathway gives rise to different C10 lactones and their accumulations report the efficiency of the peroxisomal beta-oxidation enzymes. gamma-Decalactone or 3-hydroxydecan-4-olide accumulate when acyl-CoA oxidase or 3-hydroxyacyl-CoA dehydrogenase, respectively, control the flux within the pathway. We investigated the accumulation of C10 lactones in various aeration conditions. An important accumulation of 3-hydroxydecan-4-olide was observed when increasing the aeration up to a certain point, above it its concentration was lowered, which indicates a stimulation of the activity of 3-hydroxyacyl-CoA dehydrogenase. Cultures under high-pressure were performed in order to increase the oxygen in the medium by an alternative mean. Y. lipolytica growth in glucose medium was accelerated at 0.5 MPa of total air pressure. A decrease in g-decalactone production was observed with the increase in pressure. Curiously, applying a pressure of 0.5 MPa during growth and then during biotransformation resulted in high decenolides concentrations. [less ▲]

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See detailComplex dynamics of a linear oscillator with a nonlinear attachment
Lee, Young Sup; Kerschen, Gaëtan ULg; Vakakis, Alexander F. et al

in Fifth EUROMECH Nonlinear Dynamics Conference, Eindhoven, 2005 (2005, August)

We study the dynamics of a two-degree-of-freedom (DOF) nonlinear system consisting of a grounded linear oscillator coupled to a light mass by means of an essentially nonlinear (nonlinearizable) stiffness ... [more ▼]

We study the dynamics of a two-degree-of-freedom (DOF) nonlinear system consisting of a grounded linear oscillator coupled to a light mass by means of an essentially nonlinear (nonlinearizable) stiffness. We show that the structure of periodic orbits of the undamped system greatly influences the damped dynamics, as it causes complicated transitions between modes in the damped transient motion. In addition, there is the possibility of strong passive energy transfer (energy pumping) from the linear oscillator to the nonlinear attachment if certain periodic orbits of the undamped dynamics are excited by the initial conditions.. [less ▲]

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See detailExperimental irreversible passive energy transfer in coupled nonlinear oscillators
McFarland, D. Michael; Kerschen, Gaëtan ULg; Kowtko, Jeffrey J. et al

in Fifth EUROMECH Nonlinear Dynamics Conference, Eindhoven, 2005 (2005, August)

Experimental verification of passive nonlinear energy pumping in two configurations of coupled oscillators with essential nonlinearities is carried out. In the experiments presented the nonlinear ... [more ▼]

Experimental verification of passive nonlinear energy pumping in two configurations of coupled oscillators with essential nonlinearities is carried out. In the experiments presented the nonlinear attachment interacts with a single linear mode, and passive targeted energy transfer occurs at a single ‘fast’ frequency in the neighborhood of the eigen frequency of a linear mode. Good agreement between simulated and experimental results is observed, in spite of the strongly (essentially) nonlinear and transient nature of the dynamics of the systems considered. The experiments bear out earlier predictions that a significant fraction of the energy introduced directly to a linear structure by an external impulsive (broadband) load can be transferred (pumped) to an essentially nonlinear attachment, and dissipated there locally without spreading back to the system. In addition, the reported experimental results confirm that (a) nonlinear energy pumping in systems of coupled oscillators can occur only above a certain threshold of the input energy, and (b) there is an optimal value of the energy input at which a maximum portion of the energy is absorbed and dissipated at the NES. [less ▲]

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See detailCryo-optical testing of large aspheric reflectors operating in the sub mm range
Roose, Stéphane ULg; Houbrechts, Yvette ULg; Mazzoli, Alexandra ULg et al

in Zhang, Y.; Jiang, W.; Cho, M. (Eds.) Proceedings of the 2nd SPIE symposium on Advanced Optical Manufacturing and Testing Technologies (2005, August)

The cryo-optical testing of the PLANCK primary reflector (elliptical off-axis CFRP reflector of 1550 mm x 1890 mm) is one of the major issue in the payload development program. It is requested to measure ... [more ▼]

The cryo-optical testing of the PLANCK primary reflector (elliptical off-axis CFRP reflector of 1550 mm x 1890 mm) is one of the major issue in the payload development program. It is requested to measure the changes of the Surface Figure Error (SFE) with respect to the best ellipsoid, between 293 K and 50 K, with a 1 μm RMS accuracy. To achieve this, Infra Red interferometry has been used and a dedicated thermo mechanical set-up has been constructed. This paper summarises the test activities, the test methods and results on the PLANCK Primary Reflector - Flight Model (PRFM) achieved in FOCAL 6.5 at Centre Spatial de Liege (CSL). Here, the Wave Front Error (WFE) will be considered, the SFE can be derived from the WFE measurement. After a brief introduction, the first part deals with the general test description. The thermo-elastic deformations will be addressed: the surface deformation in the medium frequency range (spatial wavelength down to 60 mm) and core-cell dimpling. [less ▲]

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See detailModel Discrimination Tools in Apoptosis
Cimatoribus, C.; Eißing, T.; N., Elvassore et al

in Foundations of Systems Biology in Engineering, FOSBE 2005 (2005, August)

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See detailPerformance comparison of heating control strategies combining simulation and experimental results.
Kummert, M.; Andre, Philippe ULg; Argiriou, A.

(2005, August)

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function ... [more ▼]

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function" paradigm. The experimental facilities did not allow a direct experimental comparison by using two identical buildings. The controllers were implemented alternatively in one building and a performance comparison was obtained in two ways: first by identifying short periods that have similar driving variables (weather conditions and building occupancy) and comparing the experimental results obtained in both cases. The second method mixes experiments and simulation using a well-tuned model of the building and its occupants. This paper discusses the results obtained using the above methods and shows that both methods give consistent estimates of the difference between controllers, while the second method allows to extrapolate useful information from the limited data available. [less ▲]

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See detailImpact of surface properties of lactic acid bacteria on the stability of emulsions
Ly, M. H.; Waché, Y.; Bouchez-Naïtali, M. et al

in Proceedings of the 2nd Mercosur Congress on Chemical Engineering – ENPROMER and 4th Mercosur Congress on Process Systems Engineering (2005, August)

Bacteria have physicochemical surface properties which depend on the chemical composition of the cell surface. These characters proceed from several type of physicochemical interactions and are involved ... [more ▼]

Bacteria have physicochemical surface properties which depend on the chemical composition of the cell surface. These characters proceed from several type of physicochemical interactions and are involved in attachment processes of microorganisms to surfaces. Thus they are of interest in several areas, as biomedicine, formation of biofilms and adhesion to apolar surfaces. Moreover, food matrix are complex heterogeneous media, which structure settles on interaction forces between molecules (van der Waals, electrostatic or structural forces…). When bacteria are present in a matrix, it is probable that their surface interacts with the other constituents. So far, few studies have mentioned this subject. In order to understand the involvement of cells surface properties in a food matrix, the effect of surface properties of lactic bacteria on the stability of model emulsions were studied. The results showed that the choice of a bacterium according to its surface properties may have a strong impact on the stability and on the behavior of an emulsion. [less ▲]

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See detailSimulation of a model-based optimal controller for heating systems under realistic hypotheses
Kummert, M.; Andre, Philippe ULg

(2005, August)

An optimal controller for auxiliary heating of passive solar buildings and commercial buildings with high internal gains is tested in simulation. Some of the most restrictive simplifications that were ... [more ▼]

An optimal controller for auxiliary heating of passive solar buildings and commercial buildings with high internal gains is tested in simulation. Some of the most restrictive simplifications that were used in previous studies of that controller (Kummert et al., 2001) are lifted: the controller is applied to a multizone building, and a detailed model is used for the HVAC system. The model-based control algorithm is not modified. It is based on a simplified internal model. It is shown that the optimal controller's performance varies strongly with the zone that is considered and the reference zone that is used. However, it is never worse than the performance of a reference controller. The global performance at the building level depends on the selected reference zone and on the building sensitivity to overheating. [less ▲]

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See detailCombined detailed and quasi steady-state time simulations for large-disturbance analysis
Van Cutsem, Thierry ULg; Grenier, Marie-Eve; Lefebvre, Daniel

in Proc. 15th Power System Computation Conference (PSCC) (2005, August)

This paper deals with the simulation of long-term power system responses to large disturbances in the presence of discrete events. A method combining detailed and quasi steady-state time simulations is ... [more ▼]

This paper deals with the simulation of long-term power system responses to large disturbances in the presence of discrete events. A method combining detailed and quasi steady-state time simulations is presented, the former being used for accuracy and the latter for ef ciency reasons. Detailed time simulation is used to analyze the short-term period following a large disturbance and identify the discrete controls triggered. Next, quasi steady-state simulation is used to simulate the same time interval with the discrete controls imposed as external events, before letting the system evolve as usual in the long term. This simple method has been successfully tested on the Hydro-Québec system. [less ▲]

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See detailINVESTIGATION OF PARAMETERS AFFECTING VOLTAGE SECURITY OF THE HELLENIC INTERCONNECTED SYSTEM
Christoforidis, George; Kabouris, John; Vournas, Costas et al

in Proc. 15th Power System Computation Conference (PSCC) (2005, August)

The Hellenic Interconnected System pre-sents a structural geographical imbalance between generation sites and load centers. This imbalance leads to bulk power transfers on long electrical distances ... [more ▼]

The Hellenic Interconnected System pre-sents a structural geographical imbalance between generation sites and load centers. This imbalance leads to bulk power transfers on long electrical distances leading to voltage stability problems. In order to improve the opera-tional practices aiming at improving the voltage security, an on-line Voltage Security Assessment tool has been installed at the National Control Center of the Hellenic Transmission System Operator that operates and controls the interconnected power system of Greece. This paper presents some indicative results obtained by the use of this tool. The analysis includes the investigation of the main parameters that affect the voltage stability of the system, such as the position of non-automatic taps of autotrans-formers, the network topology, and the spatial distribution of generation. [less ▲]

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See detailTRANSIENT DYNAMICS OF A DISPERSIVE ELASTIC WAVEGUIDE WITH AN ESSENTIALLY NONLINEAR ATTACHMENT
Vakakis, Alexander F.; Manevitch, Leonid I.; Musienko, Andrey et al

in Fifth EUROMECH Nonlinear Dynamics Conference, Eindhoven, 2005 (2005, August)

We consider the dynamics of a dispersive semiinfinite linear rod weakly connected to an essentially nonlinear end attachment. We examine resonant interactions of the attachment with incident traveling ... [more ▼]

We consider the dynamics of a dispersive semiinfinite linear rod weakly connected to an essentially nonlinear end attachment. We examine resonant interactions of the attachment with incident traveling waves propagating in the pass band of the rod, as well as resonance capture phenomena where the attachment engages in transient 1:1 internal resonance with the in-phase mode of the rod, at the bounding frequency of its pass and stop bands. The studied resonant interactions of the nonlinear attachment with traveling waves are similar to resonance capture cascades occurring in finite chain–nonlinear attachment configurations; these are the transient dynamics of the attachment as it engages in a series of instantaneous resonances with a continuous spectrum of frequencies in the pass band of the medium. As the energy of the attachment decreases due to damping and energy radiation back to the rod, the attachment engages in 1:1 resonance capture with the in-phase mode of the rod; this resonance capture occurs due to the dispersion property in the linear medium. [less ▲]

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See detailUncontrollable Materialities: Experimental Poetry and the Body in Performance
Delville, Michel ULg

in Freitag, Kornelia (Ed.) Another Language (2005, July 09)

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See detailTime Delay in Gravitational Lenses: an Alternative Route to the Hubble Constant
Magain, Pierre ULg

in Sterken, C. (Ed.) The Light-Time Effect in Astrophysics: Causes and cures of the O-C diagram (2005, July 01)

The gravitational lens phenomenon is briefly introduced. When several images of the same variable quasar are observed, a determination of the time delay, i.e. the difference in light travel time between ... [more ▼]

The gravitational lens phenomenon is briefly introduced. When several images of the same variable quasar are observed, a determination of the time delay, i.e. the difference in light travel time between these different images can lead to a determination of distances between the source, the lens and the observer and, thus, of the Hubble constant. These determinations are compared to the more classical ones based on standard candles (Cepheids and Type Ia Supernovae). [less ▲]

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See detailThe digital soil map of Wallonia (DSMW/CNSW)
Veron, Philippe; Bah, Boubacar Billo ULg; Bracke, Charles et al

in The International Cartographic Association (ICA-ACI) (Ed.) XXII International Cartographic Conference (ICC2005), A Coruña, Spain, 11-16 July 2005 (2005, July)

Based on the Belgian soil map at 1/20,000, this digital map of Wallonia (DSMW) is composed of a cartographic database describing the soil characteristics of the region. Tool for a better soil management ... [more ▼]

Based on the Belgian soil map at 1/20,000, this digital map of Wallonia (DSMW) is composed of a cartographic database describing the soil characteristics of the region. Tool for a better soil management, this database will be integrated in a geographical information system where the soil layer could be used in relation with information concerning other aspects of land development. The different operations include : map drawing finalization of non edited sheets, creation of an image layer, vectorial capture of source objects, building up of the topology, characterization of the objects, geometrical corrections, creation of a continuous layer (edge-matching), creation of a homogeneous legend, integration in a geodatabase. The DSMW in figures corresponds to : 16,000 km2; 600,000 soil polygons delimited by 15 million intermediate points (vertex); 6,000 pedological symbols; 700MB. The advantages of this computerized cartographic database are continuity, legibility, accessibility and many possibilities of thematic analyses. [less ▲]

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See detailOn an Extended Irreversible Thermodynamic description of transient heat conduction in nano structures
Lebon, Georgy ULg; Dauby, Pierre ULg; Grmela, M.

in Proceedings of the 2d IEEES Conference (2005, July)

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See detailNoise analysis for high order electromechanical sigma-delta modulators
Dong, Yufeng; Kraft, Michaël ULg; Redman-White, William

in The 5th IEE International Conference on Advanced A-D and D-A Conversion Techniques and Their Applications (2005, July)

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See detailThe use of tomography to determine the kinetics of water vapour adsorption
Lodewyckx, Peter; Léonard, Angélique ULg; Blacher, Silvia ULg

in Proceedings of Carbon 2005 – The International Carbon Conference (2005, July)

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See detailApplication of the component method to structural joints with dowel fasteners in timber construction
Ly, Dong Phuong Lam ULg; François, N.; Mertens, A. et al

in Aoki, Tetsuhiko; Itoh, yoshito (Eds.) Proceedings of the first international conference on advances in experimental structural engineering (2005, July)

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See detailQualification of large reflectors in space environment with a holographic camera based on a BSO crystal
Thizy, Cédric ULg; Stockman, Yvan ULg; Lemaire, Philippe ULg et al

in Zhang, G.; Kip, D.; Nolte, D. (Eds.) et al Photorefractive Effects, Materials, and Devices (2005, July)

The next generation of infrared - sub mm space telescopes requires some reflectors with large dimensions and high quality. These ones, according to weight issues, are based on composite materials for ... [more ▼]

The next generation of infrared - sub mm space telescopes requires some reflectors with large dimensions and high quality. These ones, according to weight issues, are based on composite materials for which the behaviors at low temperatures are badly known. A holographic interferometry method for the verification and validation of this type of reflectors in a space environment is presented. It is based on a dynamic holographic camera observing a diffuser illuminated by the object beam coming from the reflecting surface. Photorefractive crystals being self-processing and reusable mediums, the measuring range of the holographic camera is increased with respect to other optical interferometric methods. The metrological certification of the whole system was realised by the measurement of a parabolic antenna with a 1.1 meter diameter, a known behavior and placed in a simulated space environment [less ▲]

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See detailComparison between finite element calculations and holographic interferometry measurements, of the thermo-mechanical behaviour of satellite structures in composite materials
Thizy, Cédric ULg; Lemaire, Philippe ULg; Georges, Marc ULg et al

in Zhang, G.; Kip, D.; Nolte, D. (Eds.) et al Photorefractive Effects, Materials, and Devices (2005, July)

The stability requirements for the satellite structures evolve increasingly. To predict this one during the design phase a more and more used tool is the finite element calculation of thermo-elastic ... [more ▼]

The stability requirements for the satellite structures evolve increasingly. To predict this one during the design phase a more and more used tool is the finite element calculation of thermo-elastic models. The verification by measurement of these predictions on operational systems or testing rods is a key element allowing to validate these calculations and also to improve the simulations in order to study more complex cases in a reliable manner. We present the results of such a comparative study carried out on prototype structures using dynamic holographic interferometry, based on a sillenite photorefractive crystal, to measure the thermo-mechanical behavior [less ▲]

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See detailDouble-pulsed holographic interferometry with photorefractive crystals
Georges, Marc ULg; Thizy, Cédric ULg; Lemaire, Philippe ULg et al

in Zhang, G.; Kip, D.; Nolte, D. (Eds.) et al Photorefractive Effects, Materials, and Devices (2005, July)

We present the achievement of the European PHIFE project (pulsed holographic interferometer for the analysis of fast events) and which consisted in the development of holographic head principles connected ... [more ▼]

We present the achievement of the European PHIFE project (pulsed holographic interferometer for the analysis of fast events) and which consisted in the development of holographic head principles connected to a YAG Q-switch double pulsed laser. An industrial prototype has been built with the aim of Hill-field out-of-plane displacement measurement at a high repetition rate. In parallel, a new double pulse laser with 25 Hz repetition rate, high energy (800 mJ/pulse in single pulse operation), variable delay between pulses (from 1 to 200 mu s) and based on a single cavity is studied [less ▲]

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See detailPROPULSION AND VEHICLE INTEGRATION FOR REUSABLE LAUNCHER USING IN-FLIGHT OXYGEN COLLECTION
Bizzarri, Didier; Hendrick, Patrick; Heyen, Georges ULg et al

in EUROPEAN CONFERENCE FOR AEROSPACE SCIENCES (EUCASS) (2005, July)

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen ... [more ▼]

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen the available design margins in order to reduce the required technological leap and limit the economical risk associated with such a development. The aim of the ESA-funded theoretical and experimental study on an air separation device is to demonstrate the possibility of performing efficient air distillation in a compact rotating column. An integration of the vehicle, propulsion system and separation unit designs is presented aiming to optimise the overall vehicle performance while keeping technological difficulty and system complexity at a reasonable level. Reference vehicles are presented in their specific mission profiles with an emphasis on TSTO’s. Different layouts of the internal energy and mass flowsheets have been studied and were compared in order to make best use of the refrigeration capacity of the hydrogen fuel running though the propulsion system during the first phase of the flight considering the separator as a classical distillation column. This analysis provides the requirements in terms of heat exchange capacity, compression ratios and number of so-called transfer units needed in the separator. Here, the system is intentionally kept simple, to limit complexity, but the analysis is thorough and accurate, including, for example, the effect of the presence of argon. Results for a supersonic carrier are presented. An analysis of the separation unit to reach those requirements has been performed. That includes internals, practical building with estimates of pressure drop, separation performance and flow limitation. The sizing of the separator bed is provided for a carrier plane showing that such on-board separator is indeed practical. [less ▲]

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See detailTopology Discovery Using an Address Prefix Based Stopping Rule
Donnet, Benoît ULg; Friedman, Timur

in EUNICE Workshop (2005, July)

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that ... [more ▼]

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that allows the discovery of a large portion of nodes and links in the network while strongly reducing probing redundancy on nodes and destinations as well as the amount of probes sent. In this paper, we propose to reduce more strongly the load on destinations and, more essentially, the communication cost required for the cooperation by introducing a probing stopping rule based on CIDR address prefixes. [less ▲]

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See detailBioencapsulated peptides : preparation and application for wound healing
Markvicheva, E; Stashevskaya, K; Grandfils, Christian ULg

in Proceeding Meeting BRG 2005 (2005, June 24)

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See detailLeast Construction Cost of FSO Offshore Structures and LNG Gas Carriers
Rigo, Philippe ULg; Matagne, Jérôme ULg; Caprace, Jean-David ULg

in ISOPE, The fifteenth International Offshore and Polar Engineering Conference, Seoul (2005, June 19)

In this paper, scantling optimization a FSO offshore structure and a medium size capacity LNG gas carrier are presented. Optmization is based on the LBR5 least cost optimization package. Main originality ... [more ▼]

In this paper, scantling optimization a FSO offshore structure and a medium size capacity LNG gas carrier are presented. Optmization is based on the LBR5 least cost optimization package. Main originality and advantage is to combine the minimization of the construction cost with the preliminary design stage. The optimum scantling (least cost) is determined at the earliest design stage, this means before the signature of the contract. Cost savings of 5 to 10% are currently recorded. Relevant information on the methodology and applications to a FSO unit and a LNG carrier are presented in the paper. [less ▲]

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See detailEmploi d'outils décisionnels et de pilotage de la fumure en région wallonne
Destain, Jean-Pierre ULg; Godden, Bernard; Luxen, Pierre et al

in Soudi, Brahim; Debouche, Charles; Krim, Lhassan (Eds.) et al Gestion environnementale de l'agriculture (2005, June 09)

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See detailLa coopération inter-universitaire dans les domaines du transport et de la logistique: l'expérience tuniso-belge
Marchal, Jean ULg

(2005, June 03)

L’objectif principal de la collaboration inter-universitaire concernée est d’assurer un transfert de connaissances, permettant de participer au développement socio-économique de la Tunisie et de la région ... [more ▼]

L’objectif principal de la collaboration inter-universitaire concernée est d’assurer un transfert de connaissances, permettant de participer au développement socio-économique de la Tunisie et de la région du Maghreb par la création d’un centre d’enseignement et de formation en transport et logistique. Le projet de coopération permet le développement de trois types de formation : - L’une de nature plus ciblée par la réalisation de stages de formation spécifiques qui permet un premier contrôle des aptitudes des futurs enseignants - La deuxième de nature académique par le développement d’un mastère en transport et logistique - La troisième de nature professionnelle par le développement également d’un mastère spécialisé dans le même domaine Ces formations doivent contribuer notamment à la prise de conscience de l’extrême nécessiter de s’inscrire dans une politique de transport intermodal s’articulant autour de plates-formes intermodales afin d'accroître principalement la mobilité des biens industriels et des produits agricoles dans un souci constant de préservation de l'environnement. [less ▲]

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See detailCOSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses
Courbin, F.; Eigenbrod, A.; Vuissoz, C. et al

in Mellier, Y.; Meylan, G. (Eds.) Gravitational Lensing Impact on Cosmology (2005, June 01)

We describe a new project aiming at measuring time delays for most known lensed quasars, from optical light curves obtained with five (almost) dedicated 1-2 m telescopes in the Northern and Southern ... [more ▼]

We describe a new project aiming at measuring time delays for most known lensed quasars, from optical light curves obtained with five (almost) dedicated 1-2 m telescopes in the Northern and Southern hemispheres. The goal is to evaluate the Hubble constant H[SUB]0[/SUB] with a precision below 2%. We present here numerical simulations in order to define the optimal temporal sampling in our observations as a function of typical quasar variations, object visibility, and for a given accuracy on the individual photometric points. It is also emphasized that the ongoing effort to obtain deep imaging using both space and ground based facilities must be continued, as illustrated by the comparison of HST and VLT near-IR images of the `cloverleaf': H 1413+117. [less ▲]

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See detailQuasi steady-state models for long-term voltage and frequency dynamics simulation
Grenier, Marie-Eve; Lefebvre, Daniel; Van Cutsem, Thierry ULg

in Proc. IEEE Power Tech conference (2005, June)

The Quasi Steady-State (QSS) approximation of long-term dynamics relies on time-scale decomposition and consists of replacing faster phenomena by their equilibrium conditions, in order to reduce the ... [more ▼]

The Quasi Steady-State (QSS) approximation of long-term dynamics relies on time-scale decomposition and consists of replacing faster phenomena by their equilibrium conditions, in order to reduce the complexity of the whole model and increase the computation efficiency of time simulations. This paper describes the extension of a QSS model extensively used in long-term voltage stability studies, to readily incorporate the frequency dynamics that takes place over the same time scale. This extended QSS model relies on a common-frequency assumption. Its advantages, limitations and possible improvements are discussed through simulation results on the Hydro-Québec system, where it has been compared to full time scale simulations. Disturbances with an impact on either frequency or voltages are considered and the coupling between these two aspects of long-term dynamics is briefly discussed. [less ▲]

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See detailMulti-frequency passive non-linear targeted energy transfers in systems of couples oscillators
Tsakirtzis, Stylianos; Panagopoulos, Panagiotis; Kerschen, Gaëtan ULg et al

in 5th GRACM International Congress on Computational Mechanics, Limassol, 2005 (2005, June)

We study the dynamics of a system of coupled linear oscillators with a multi-DOF end attachment with essential (nonlinearizable) stiffness nonlinearities. We show numerically that the multi-DOF attachment ... [more ▼]

We study the dynamics of a system of coupled linear oscillators with a multi-DOF end attachment with essential (nonlinearizable) stiffness nonlinearities. We show numerically that the multi-DOF attachment with damping can passively absorb broadband energy from the linear system in a one-way, irreversible fashion, acting in essence as nonlinear energy sink (NES). Strong passive targeted energy transfer from the linear to the nonlinear subsystem is possible, over wide frequency and energy ranges. We numerically demonstrate that the topological structure of the periodic orbits in the frequency – energy plane of the underlying hamiltonian system greatly influences the strength of targeted energy transfer in the damped system, and governs to a great extent the overall transient damped dynamics. This work may be regarded as a contribution towards proving the efficacy the utilizing essentially nonlinear attachments as passive broadband boundary controllers. [less ▲]

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See detailWhole-body barometric plethysmography in healthy dogs : influence of jet nebulizer and bias flow rate on the results of a bronchoprovocative test
Talavera, J.; Bernaerts, Frederique ULg; Schuller, S. et al

in ACVIM Meeting - Baltimore (USA) - juin 2005 (2005, June)

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See detailOptimal synthesis of mechanisms using time-varying dimensions and natural coordinates
Collard, Jean-François; Fisette, Paul; Duysinx, Pierre ULg

in Herskowitz, José (Ed.) Proceedings of the 6th World Congress of Structural and Multidisciplinary Optimization (WCSMO6) (2005, June)

This paper presents a simple approach to optimize the dimensions and the positions of 2D mechanisms for path or function-generator synthesis. The proposed method is particularly adapted to assembled ... [more ▼]

This paper presents a simple approach to optimize the dimensions and the positions of 2D mechanisms for path or function-generator synthesis. The proposed method is particularly adapted to assembled mechanisms since time-varying dimensions always satisfy the assembly conditions which may represent a real difficulty when dealing with closed-loop mechanisms. The objective is to minimize the strain energy of the bars - considered as flexible - of the mechanism when this one follows perfectly the desired path. Two optimization strategies are developed and criticized. The first one is based on separated optimizations of design parameters and point coordinates. The second one is more global and is performed in two stages : multiple local synthesis are needed first to find the initial point coordinates, and then a global synthesis stage is undertaken to find both the best dimensions and coordinates. The use of natural coordinates is also particularly interesting since the only non linear functions to optimize are distance functions, and the objective function is rather well-conditioned for a gradient-based optimizer. The question of finding the global optimum is addressed and discussed. Since a standard genetic algorithm may fail to find it, a different approach is proposed: exploring the design space to find several local optima among which the designer will choose the most relevant one taking other design constraints into account. A simple technique is applied which consists in running multiple optimization processes starting from uniformly-distributed initial dimensions (full-factorial design of experiments) across the parameter space. Three applications are presented: a simple four-bar path synthesis to illustrate the optimization strategies, a four-bar steering linkage synthesis for function generation – Ackermann relation to highlight the limits of both strategies, and eventually a six-bar steering mechanism to explore the design space and find different local optima. [less ▲]

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See detailFast contingency filtering based on linear voltage drop estimates
Otomega, Bogdan; Van Cutsem, Thierry ULg

in Proc. IEEE PowerTech Conference (2005, June)

This paper deals with the filtering of harmless contingencies in voltage stability and security analyses. In many systems, a post-contingency load flow allows to identify the contingencies with severe ... [more ▼]

This paper deals with the filtering of harmless contingencies in voltage stability and security analyses. In many systems, a post-contingency load flow allows to identify the contingencies with severe impact on voltage stability, as causing either divergence or large voltage drops. However, for filtering purposes, accurate voltage drops need not be computed; linear estimates obtained from sensitivity formulas are appropriate. For a given contingency, the method used in this paper solves a sparse linear system to update the phase angles, assuming constant voltage magnitudes. Then, assuming constant active power flows in the branches, a second sparse system is solved to update the voltage magnitudes. This yields better accuracy than one full load flow iteration while retaining the sparse structure of a decoupled formulation. For contingency analysis, the incidents are filtered by comparing the voltage drops to a threshold. For secure power margin computations, the same procedure is used after stressing the system in the specified direction. The method has been tested on a real system where it has been found to combine simplicity of implementation, quality of filtering and computational efficiency. [less ▲]

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See detailA unified finite element framework for the dynamic analysis of controlled flexible mechanisms
Bruls, Olivier ULg; Duysinx, Pierre ULg; Golinval, Jean-Claude ULg

in Proceedings of the ECCOMAS Conference on Advances in Computational Multibody Dynamics (2005, June)

This paper proposes a unified formalism for the simulation of mechatronic systems with complex flexible mechanisms. The equations of motion are formulated using a nonlinear Finite Element approach for the ... [more ▼]

This paper proposes a unified formalism for the simulation of mechatronic systems with complex flexible mechanisms. The equations of motion are formulated using a nonlinear Finite Element approach for the mechanism, and the block diagram language for the control system. The set of strongly coupled equations of motion is constructed numerically, and integrated in the time domain using the generalized-alpha method. Convergence and stability properties are thus guaranteed for the simulation algorithm. Two illustrative examples are treated in the fields of vehicle dynamics and robotics respectively. [less ▲]

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See detailOn-Line Transient Engine Diagnostics in a Kalman Filtering Framework
Borguet, Sébastien ULg; Dewallef, Pierre ULg; Léonard, Olivier ULg

in Proceedings of the ASME Turbo Expo 2005 (2005, June)

A common assumption made in the performance assessment of a turbine engine for aircraft propulsion consists in restricting the data processing to steady-state data. This especially holds for on-board ... [more ▼]

A common assumption made in the performance assessment of a turbine engine for aircraft propulsion consists in restricting the data processing to steady-state data. This especially holds for on-board performance monitoring of a commercial aircraft which spends up to 90% of the time in cruise flight where such conditions are satisfied. The present contribution is intended to investigate the ability of a diagnosis method to process unsteady data rather than steady-state data. The aim of this unsteady approach is to strongly reduce the time and the efforts spent to obtain a reliable diagnosis. In order to assess the improvements in terms of diagnosis efficiency and engine operability, the resulting diagnostic method is tested for different degradations that can be expected on commercial turbofans. The results are also compared to those obtained from cruise flight steady-state data in order to balance the two approaches. [less ▲]

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See detailFlutter Clearance of a Non-linear aircraft
Benini, Guilherme; Vio, Gareth Arthur; Dimitriadis, Grigorios ULg et al

in Proceedings of the 2005 International Forum on Aeroelasticity and Structural Dynamics (2005, June)

Flight flutter testing is always carried out under the assumption that aircraft are linear. Recently, this assumption has started to come under question, especially as far as military aircraft are ... [more ▼]

Flight flutter testing is always carried out under the assumption that aircraft are linear. Recently, this assumption has started to come under question, especially as far as military aircraft are concerned. This paper deals with possible methodologies for flight flutter testing of aircraft that are no longer assumed linear. Simulated flight testing is performed for a simple non-linear aeroelastic system with cubic stiffness. The flutter speeds predicted using some of the classical linear flutter prediction methods as well as a non-linear method are compared. It is shown that, for non-linear system undergoing Hopf Bifurcations, classical linear flutter prediction can predict the flutter envelope with reasonable accuracy. However, fully non-linear system identification and stability analysis can not only predict the flutter point but also determine whether it is a linear or non-linear flutter point (i.e. whether divergent or Limit Cycle Oscillations will ensue). Additionally, the non-linear method can predict the amplitudes of LCOs that will occur post-critically. The application of the nonlinear method was successful for noise free data, but the problem of noise corruption still needs further investigation. [less ▲]

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See detailEfficient Algorithms for Large-Scale Topology Discovery
Donnet, Benoît ULg; Raoult, Philippe; Friedman, Timur et al

in ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems (2005, June)

There is a growing interest in discovery of internet topology at the interface level. A new generation of highly distributed measurement systems is currently being deployed. Unfortunately, the research ... [more ▼]

There is a growing interest in discovery of internet topology at the interface level. A new generation of highly distributed measurement systems is currently being deployed. Unfortunately, the research community has not examined the problem of how to perform such measurements efficiently and in a network-friendly manner. In this paper we make two contributions toward that end. First, we show that standard topology discovery methods (e.g., skitter) are quite inefficient, repeatedly probing the same interfaces. This is a concern, because when scaled up, such methods will generate so much traffic that they will begin to resemble DDoS attacks. We measure two kinds of redundancy in probing (intra- and inter-monitor) and show that both kinds are important. We show that straightforward approaches to addressing these two kinds of redundancy must take opposite tacks, and are thus fundamentally in conflict. Our second contribution is to propose and evaluate Doubletree, an algorithm that reduces both types of redundancy simultaneously on routers and end systems. The key ideas are to exploit the tree-like structure of routes to and from a single point in order to guide when to stop probing, and to probe each path by starting near its midpoint. Our results show that Doubletree can reduce both types of measurement load on the network dramatically, while permitting discovery of nearly the same set of nodes and links. [less ▲]

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See detailApplication of a novel oscillatory flow screening micro-reactor to a biotransformation in a two-phase medium
Vicente, A.; Reis, N.; Nobre, C. et al

in Biochemical engineering : frontiers and advances in biotechnology, biological and biomolecular engineering : abstracts”. [S.n. : s.l.] (2005, June)

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See detailThe Critical Neighbourhood Range for Asymptotic Overlay Connectivity in Dense Ad Hoc Networks
Calomme, Sandrine; Leduc, Guy ULg

in Challenges in Ad Hoc Networking (2005, June)

We define, for an overlay built on top of an ad hoc network, a simple criterion for neighbourhood: two overlay nodes are neighbours if and only if there exists a path between them of at most R hops, and R ... [more ▼]

We define, for an overlay built on top of an ad hoc network, a simple criterion for neighbourhood: two overlay nodes are neighbours if and only if there exists a path between them of at most R hops, and R is called the (overlay) neighbourhood range. A small R may result in a disconnected overlay, while an unnecessarily large R would generate extra control traffic. We are interested in the minimum R ensuring overlay connectivity, the so-called critical R. We derive a necessary and sufficient condition on R to achieve asymptotic connectivity of the overlay almost surely, i.e. connectivity with probability 1 when the number of overlay nodes tends to infinity, under the hypothesis that the underlying ad hoc network is itself asymptotically almost surely connected. This condition, though asymptotic, sheds some light on the relation linking the critical R to the number of nodes n, the normalized radio transmission range r and the overlay density D (i.e., the proportion of overlay nodes). This condition can be considered as an approximation when the number of nodes is large enough. Since r is considered as a function of n, we are able to study the impact of topology control mechanisms, by showing how the shape of this function impacts the critical R. [less ▲]

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See detailAn interior point method based optimal power flow
Capitanescu, Florin ULg; Glavic, Mevludin; Wehenkel, Louis ULg

(2005, June)

This paper deals with the solution of an optimal power flow (OPF) problem by the interior point method (IPM). The latter is a very appealing approach to this nonlinear programming problem due to its speed ... [more ▼]

This paper deals with the solution of an optimal power flow (OPF) problem by the interior point method (IPM). The latter is a very appealing approach to this nonlinear programming problem due to its speed of convergence and ease of handling inequality constraints. Two interior point algorithms are presented and compared: the pure primal-dual and the predictor-corrector. Several implementation aspects of these IPM algorithms are also discussed. The OPF is formulated in rectangular coordinates which confers some significant advantages because generally its objective and constraints are quadratic functions. Among the large variety of OPF objectives, emphasis is put on two classical ones: the minimization of generation cost and the minimization of transmission active power losses. The solution obtained by both algorithms proves to be robust for the two OPF sub-problems (optimization of active power flows and reactive power flows) as well as for a full OPF applied to the former objective, which is unanimously recognized as the hardest problem to solve. Finally, numerical results on three test systems ranging from 60 to 300 buses are provided. [less ▲]

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See detailA CIDR Prefix Stopping Rule for Topology Discovery
Donnet, Benoît ULg; Friedman, Timur

in Proc. Algotel (2005, May)

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that ... [more ▼]

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that allows the discovery of a large portion of nodes and links in the network while strongly reducing probing redundancy on nodes and destinations as well as the amount of probes sent. In this paper, we propose to reduce more strongly the load on destinations and, more essentially, the communication cost required for the cooperation by introducing a probing stop rule based on CIDR address prefixes. [less ▲]

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See detailEffect of back mixing during convective drying of wastewater sludges
Léonard, Angélique ULg; Meneses, Eustedio; Salmon, Thierry ULg et al

in Proceeedings of the joint of AFSIA (Association Française de Séchage dans l'Industrie et l'Agriculture) and Working group on Drying of EFCE at INA P-G, Paris, 12th and 13th May, 2005 (2005, May)

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See detailLe tunnel TGV de Soumagne (Belgique) et ses difficultés géologiques
Janssens, B.; Bouhenni; Dethy, B. et al

in Colloque Géoline (2005, May)

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See detailGeneralized Shape optimization based on the Level Set method
Van Miegroet, Laurent ULg; Moës, Nicolas; Fleury, Claude ULg et al

in Herskowitz, José (Ed.) Proceedings of the 6th World Congress of Structural and Multidisciplinary Optimization (WCSMO6) (2005, May)

This paper describes a first step work devoted to applying XFEM and Level Sets methods in optimization of structures. This first step work is based on integrating an existing XFEM code within a general ... [more ▼]

This paper describes a first step work devoted to applying XFEM and Level Sets methods in optimization of structures. This first step work is based on integrating an existing XFEM code within a general open optimization tool, SAMCEF BOSS QUATTRO. Unlike most of the existing works, this approach is more shape optimization oriented. A library of pre-formatted basic geometric entities (such as ellipses, squares, triangles, etc.) described by Level Sets functions are used. These basic Level Set features can be combined to represent many kinds of interfaces and holes. The construction parameters of the basic Level Sets are considered as the design variables. In order to evaluate the sensitivities, a finite difference scheme over the design variables is used in this first work. Different mechanical responses (energy, weight, displacement, . . .) can be considered as objective functions or constraints in the problem formulation. Several academic 2D test cases of shape and topology optimization are presented within the XFEM and Level Set approach. In addition, a work by Missoum et al. [11], in which the shape and topology optimization of the structure is carried out by an optimal selection of holes characteristics with a genetic algorithm is presented. [less ▲]

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See detailHigher order sigma-delta modulators interfaces for capapcitive sensors
Kraft, Michaël ULg; Dong, Yufeng

in 2005 NSTI Nanotechnology Conference and Trade Show : NSTI Nanotech 2005 (2005, May)

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See detailOptimization of mechatronic systems: application to a modern car equipped with a semi-active suspension
Duysinx, Pierre ULg; Bruls, Olivier ULg; collard, Jean-François et al

in Herskowitz, José (Ed.) Proceedings of the 6th World Congress of Structural and Multidisciplinary Optimization (WCSMO6) (2005, May)

The research aims at developing a global mechatronic approach to model, simulate and optimize complex industrial applications. The approach is illustrated with the simulation and the optimization of a ... [more ▼]

The research aims at developing a global mechatronic approach to model, simulate and optimize complex industrial applications. The approach is illustrated with the simulation and the optimization of a modern car (an Audi A6) equipped with a controlled semi-active suspension. An optimization procedure is used to find the best sub-system parameters in order to improve the comfort of the passengers while preserving the car ride and handling performances. Two different modeling and optimization approaches are used and compared. The first one is realized in the MATLAB-SIMULINK environment and is based on a symbolic multibody model of the chassis while the hydraulic actuators, and the controller are integrated using S-functions. Optimization is also carried out in MATLAB using algorithms available in MATLAB libraries, especially a genetic algorithm (GA). On the other hand, the second approach relies on a multibody model based on the Finite Element method whereas the optimization can be realized with an industrial open optimization tool. [less ▲]

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See detailModelling, Simulation and Optimization of a Shipbuilding Workshop
Bair, Frédéric ULg; Langer, Yves; Caprace, Jean-David ULg et al

in COMPIT'2005 -Conference on Computer Applications and Information Technology in the Maritime Industries, Hamburg (2005, May)

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See detailProduction of resorcinol formaldehyde xerogels by convective drying
Léonard, Angélique ULg; Jomaa, Wahbi; Crine, Michel ULg

in Proceedings of the joint conference of AFSIA (Association Française pour le Séchage dans l’Industrie et l’Agriculture) and Working group on Drying of EFCE at INA P-G, Paris, 12th and 13th May, 2005 (2005, May)

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See detailOptimization of Surface Allocation using Heuristic Approaches
Langer, Yves; Bay, Maud ULg; Crama, Yves ULg et al

in COMPIT 2005 , Hambourg, Germany (2005, May)

In this paper, we present a scheduling problem that arises in factories producing large building blocks (in our case, a shipyard workshop producing prefabricated keel elements). The factory is divided in ... [more ▼]

In this paper, we present a scheduling problem that arises in factories producing large building blocks (in our case, a shipyard workshop producing prefabricated keel elements). The factory is divided in several equal size areas. The blocks produced in the factory are very large, and, once a building block is placed in the factory, it cannot be moved until all processes on the building block are finished. The blocks cannot overlap. The objective is to maximize the number of building blocks produced in the factory during a certain time window. To solve this problem, we propose heuristics inspired by techniques initially developed for the three-dimensional bin packing problem, e.g. Faroe and al. (2003), since constraints for both problems are quite similar. Starting from an unfeasible solution, where blocks can overlap, a Guided Local Search (GLS) heuristic is used to minimize the sum of total overlap. If a solution with zero overlap is found, then it is a feasible solution; otherwise the block with the biggest overlap is removed and the procedure is restarted. The GLS algorithm has been improved by Fast Local Search (FST) tech- niques in order to speed up convergence to a local minimum. Additionally, neighborhoods are restricted to their smallest size so as to allow their evaluation in polynomial-time. In a last step, we explain the additional real-life issues arising in the industrial application and how firm-specific constraints can be conveniently considered by the model. [less ▲]

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See detailCaracterization del jambon belga de las ardenas.
Hannecart, François; Deroanne, Claude; Sindic, Marianne ULg

in Abstracts du 3ème Congrès mondial du jambon sec (2005, May)

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See detailIntegration of vehicle, propulsion system and separation unit designs for a launcher using in-flight oxygen collection
Bizzarri, Didier; Hendrick, Patrick; Heyen, Georges ULg et al

in AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference (2005, May)

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen ... [more ▼]

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen the available design margins in order to reduce the required technological leap and limit the economical risk associated with such a development. The aim of the ESA-funded theoretical and experimental study on an air separation device is to demonstrate the possibility of performing efficient air distillation in a compact rotating column. An integration of the vehicle, propulsion system and separation unit designs is presented aiming to optimise the overall vehicle performance while keeping technological difficulty and system complexity at a reasonable level. Reference vehicles are presented in their specific mission profiles with an emphasis on TSTO’s. Different layouts of the internal energy and mass flowsheets are compared, in order to make best use of the refrigeration capacity of the hydrogen fuel running though the propulsion system during the first phase of the flight considering the separator as a classical distillation column. This analysis provides the requirements in terms of heat exchange capacity, compression ratios and number of so-called transfer units needed in the separator. Here, the system is intentionally kept simple, to limit complexity, but the analysis is thorough and accurate, including, for example, the effect of the presence of argon. An analysis of the separation unit to reach those requirements is proposed. That includes internals, practical building with estimates of pressure drop, separation performance and flow limitation. Analysis of size reduction of the distillation unit from usual 1-g column to the high-g unit is provided as well as the scale up methodology of laboratory results. First experimental results obtained with our centrifugally enhanced distillation separation system are presented and perspectives for a larger on-board operational unit proposed. [less ▲]

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See detailExperimental Study Of An In-Flight Air Separation Device
Bizzarri, Didier; Hendrick, Patrick; Heyen, Georges ULg et al

in AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference (2005, May)

Intending to provide in-flight Oxygen Collection capability to new launchers, a subscale model of a centrifugally enhanced air distillation unit is under development. The vehicle we foresee for this ... [more ▼]

Intending to provide in-flight Oxygen Collection capability to new launchers, a subscale model of a centrifugally enhanced air distillation unit is under development. The vehicle we foresee for this application is described elsewhere, the present paper concentrating only on the technological and experimental aspects. While the test setup has already been shown to be able to provide the adequate cooling power, the rig is still under construction. The experimental and technical aspects include choices and main trade-offs that had to be made during the design process. Of particular interest are the stainless steel all welded heat exchangers allowing for deep cooling and liquefaction of air from the main compressor and dryers. Specifically, developed hardware is described in details. On the test rig side, design of the rotating cryogenic separator is explained, including mechanical aspects, heat management and sealing. The whole system has modes of operation allowing, among other parameters, to explore various air compositions and mass flows rates on the gaseous and liquid sides. Perspectives are given for the testing of the separator. [less ▲]

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See detailTypical and atypical myopathies of horses
Votion, Dominique ULg

in 2ème Congrès de biologie clinique (2005, April 24)

Une fonction musculaire efficiente repose sur l’intégrité fonctionnelle des systèmes nerveux et musculaire. Les myopathies peuvent résulter d’atteintes nerveuses (myopathies neurogéniques) ou musculaires ... [more ▼]

Une fonction musculaire efficiente repose sur l’intégrité fonctionnelle des systèmes nerveux et musculaire. Les myopathies peuvent résulter d’atteintes nerveuses (myopathies neurogéniques) ou musculaires (myopathies myogéniques). La classification des myopathies selon leur origine n’est pas aisée car, quel que soit le processus pathologique initial, les signes cliniques et les lésions histologiques sont souvent aspécifiques. Dans cet écrit, les principales myopathies équines sont classées selon le tableau clinique. Ainsi, les subdivisions de ce classement incluent le diagnostic différentiel des principales atteintes neuromusculaires. Un type de myopathie pouvant avoir différents tableaux cliniques, il peut se retrouver plusieurs fois dans le tableau. Le détail des principales myopathies équines est précédé de la description des outils dont dispose le vétérinaire afin de poser le diagnostic de myopathie voire de spécifier le type de myopathie dont souffre le cheval. [less ▲]

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See detailCriterion-related validity of the revised Belgian Nursing Minimium Data Set (B-NMDS) throught the actual B-NMDS
THONON, Olivier ULg; VAN BOVEN, Caroline ULg; CODOGNOTTO, Jean ULg et al

in OUD, Nico; SERMEUS, Walter; EHNFORS, Margareta (Eds.) Proceedings of the fifth biennial European Conference of the Association for Common European Nursing Diagnoses, Interventions and Outcomes (2005, April)

Detailed reference viewed: 15 (1 ULg)