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See detailMultiphysics modeling and optimization of mechatronic multibody systems
Samin, Jean-Claude; Bruls, Olivier ULg; Collard, Jean-François et al

in Multibody System Dynamics (2007), 18(3), 345-373

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are ... [more ▼]

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are currently proposed to deal with multiphysics modeling, e.g., graph theories, equational approaches, co-simulation techniques. Recent works have pointed out their relative advantages and drawbacks, depending on the application to deal with: model size, model complexity, degree of coupling, frequency range, etc. This paper is the result of a close collaboration between three laboratories, and aims at showing that for "non-academic" mechatronic applications (i.e., issuing from real industrial issues), multibody dynamics formulations can be generalized to mechatronic systems, for the model generation as well as for the numerical analysis phases. Model portability being also an important aspect of the work, they must be easily interfaced with control design and optimization programs. A global "demonstrator", based on an industrial case, is discussed: multiphysics modeling and mathematical optimization are carried out to illustrate the consistency and the efficiency of the proposed approaches. [less ▲]

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See detailMULTIPHYSICS MODELING OF CELL/MATRIX GROWTH ON 3D STRUCTURES.
Guyot, Yann ULg; Papantoniou, Ioannis; Chai, Yoke Chin et al

Conference (2013, August 26)

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See detailMultiphysics modeling of mechatronic multibody systems
Fisette, Paul; Bruls, Olivier ULg; Swevers, Jan

in Proceedings of ISMA 2006 (2006, September)

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are ... [more ▼]

Modeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are currently proposed to deal with multiphysics modeling, e.g. graph theories, equational approaches, co-simulation techniques. Recent works have pointed out their relative advantages and drawbacks, depending on the application to deal with: model size, model complexity, degree of coupling, frequency range, etc. This paper is the result of a close collaboration between three Belgian laboratories, and aims at showing that for "non-academic" mechatronic applications (i.e. issuing from real industrial issues), multibody dynamics formulations can be generalized to mechatronic applications, for the model generation as well as for the numerical analysis phases. Model portability being also an important aspect of the work, they must be easily interfaced with control design and optimization programs. A global "demonstrator", based on an industrial case, is discussed: multiphysics modeling, control design and mathematical optimization are carried out to illustrate the consistency and the efficiency of the proposed approaches. [less ▲]

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See detailMultiplane two-dimensional versus real time three-dimensional transesophageal echocardiography in ischemic mitral regurgitation.
Fattouch, K.; Castrovinci, S.; Murana, G. et al

in Echocardiography (2011)

OBJECTIVES: Intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) has been suggested to be a valuable technique for the evaluation of the mechanisms of ischemic mitral regurgitation ... [more ▼]

OBJECTIVES: Intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) has been suggested to be a valuable technique for the evaluation of the mechanisms of ischemic mitral regurgitation (IMR). Studies comparing multiplane two-dimensional (2D) with 3D TEE reconstruction of the mitral valve using the new mitral valve quantification (MVQ) software are lacking. We undertook a prospective comparison between multiplane 2D and 3D TEE for the assessment of IMR. METHODS: We evaluated echocardiographically 45 patients with IMR who underwent mitral valve surgery in our institution. 2D and 3D TEE examinations followed by a 3D offline assessment of the mitral valve apparatus were performed in all patients. Offline analysis of mitral valve apparatus was conducted with QLAB-MVQ. RESULTS: 3D TEE image acquisitions were performed in a short period of time and were feasible in all patients. Real time 3D TEE imaging was superior to 2D in identifying specific mitral scallops (A1, A3, P1, P3) and commissures. When compared with 2D TEE, 3D offline reconstruction of the mitral valve allows an accurate quantification of the shape and diameters of the mitral annulus. Both approaches provide almost similar values for the tenting area and the coaptation depth. The 3D approach gave the advantage of direct calculation of the leaflets angles, tenting volume, and surface of the leaflets. The interpapillary muscles distance at the level of the papillary muscle head was greater in 2D than in 3D. CONCLUSIONS: 3D TEE imaging provides valuable and complementary information to multiplane 2D TEE for the assessment of patients with IMR. [less ▲]

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See detailA multiple case study of verbal short-term memory in velo-cardio-facial syndrome
Majerus, Steve ULg; Glaser, B.; Van der Linden, Martial ULg et al

in Journal of Intellectual Disability Research (2006), 50(Pt 6), 457-469

Background: Velo-cardio-facial syndrome (VCFS, 22q11.2 deletion) is characterized by severely delayed language development. The current study explored the integrity of verbal short-term memory (STM), a ... [more ▼]

Background: Velo-cardio-facial syndrome (VCFS, 22q11.2 deletion) is characterized by severely delayed language development. The current study explored the integrity of verbal short-term memory (STM), a cognitive function critically involved in language development, in eight children with VCFS. Methods: Using a multiple case study design, we presented a series of STM tasks exploring immediate serial recall for word and non-word lists to eight children with VCFS (aged 8 - 12 years) and to chronological-age-matched control groups. A first task assessed the integrity of phonological coding in verbal STM by comparing recall for phonologically similar and dissimilar words. Subsequently, the interaction between verbal knowledge and STM capacity was investigated by comparing recall for high- and low-imageability words, for high- and low-frequency words, and for words and non-words. A final task assessed short-term serial order recognition for digit sequences. Results: When computing the number of items recalled in the word recall tasks, independently of their serial position, only one child presented consistent difficulties. Short-term recall of non-words was normal in each child. Phonological similarity and verbal knowledge influenced STM performance to a similar extent in children with VCFS and controls. On the other hand, when applying a strict serial recall criterion, difficulties with the word and non-word recall tasks were observed in most children. Half of the patients were also impaired in the serial order recognition task. Conclusions: Despite mild intellectual disability, it is possible for short-term retention capacities for verbal item information to be at an age-appropriate level in VCFS. However, STM for serial order information could be impaired more specifically. [less ▲]

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See detailMultiple changes in peptide and lipid expression associated with regeneration in the nervous system of the medicinal leech
Mériaux, Céline; Arafah, Karim; Tasiemski, Aurélie et al

in PLoS ONE (2011), 6(4), 18359

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See detailMultiple Clinical and Paraclinical Analyses of Chronic Tension-Type Headache Associated or Unassociated with Disorder of Pericranial Muscles
Schoenen, Jean ULg; Gérard, P.; De Pasqua, Victor ULg et al

in Cephalalgia : An International Journal of Headache (1991), 11(3), 135-9

Thirty-two female patients fulfilling the diagnostic criteria of chronic tension-type headache underwent multiple clinical (severity index before and after biofeedback therapy; anxiety score) and ... [more ▼]

Thirty-two female patients fulfilling the diagnostic criteria of chronic tension-type headache underwent multiple clinical (severity index before and after biofeedback therapy; anxiety score) and paraclinical (pericranial EMG levels and pressure-pain thresholds, temporalis exteroceptive silent period) assessments. Twenty-three patients (72%) had at least one increased EMG level and/or at least one decreased pain threshold and qualified for the subgroup" associated with disorder of pericranial muscles" (code 2.2.1). Nine patients (28%) were within the normal range for both investigations and would have been classified in the subgroup "unassociated with such disorder" (code 2.2.2). No significant differences were found between these two groups of patients for headache severity, anxiety, response to biofeedback therapy or duration of temporalis second exteroceptive silent period. The various clinical and paraclinical parameters were not significantly correlated to each other. It is therefore suggested that the subdivision of chronic tension-type headache in two subgroups based on pericranial EMG levels and/or pain sensitivity might be artificial. Since both of the latter and temporalis silent periods vary independently, they appear complementary in the study of tension-type headache patients and probably represent peripheral abnormalities, which are induced to varying intensities by a common central nervous system dysfunction. [less ▲]

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See detailA multiple criteria analysis for-household solid waste management in the urban community of Dakar
Kapepula, K. M.; Colson, Gérard ULg; Sabri, Karim ULg et al

in Waste Management (2007), 27(11), 1690-1705

Household solid waste management is a severe problem in big cities of developing countries. Mismanaged solid waste dumpsites produce bad sanitary, ecological and economic consequences for the whole ... [more ▼]

Household solid waste management is a severe problem in big cities of developing countries. Mismanaged solid waste dumpsites produce bad sanitary, ecological and economic consequences for the whole population, especially for the poorest urban inhabitants. Dealing with this problem, this paper utilizes field data collected in the urban community of Dakar, in view of ranking nine areas of the city with respect to multiple criteria of nuisance. Nine criteria are built and organized in three families that represent three classical viewpoints: the production of wastes, their collection and their treatment. Thanks to the method PROMETHEE and the software ARGOS, we do a pair-wise comparison of the nine areas, which allows their multiple criteria rankings according to each viewpoint and then globally. Finding the worst and best areas in terms of nuisance for a better waste management in the city is our final purpose.. fitting as well as possible the needs of the urban community. Based on field knowledge and on the literature, we suggest applying general and area-specific remedies to the household solid waste problems. (C) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailMultiple criteria and multiple periods performance analysis: the comparison of telecommunications sectors in the Maghreb countries
Mbangala, Mapapa ULg; Colson, Gérard ULg; Sabri, Karim ULg

in Journal of Telecommunications and Information Technology (2006)

In four Maghreb countries (Algeria, Morocco, Mauritania and Tunisia), a considerable improvement of the situation of the telecommunication operators has been noticed during the nineties. The evolution in ... [more ▼]

In four Maghreb countries (Algeria, Morocco, Mauritania and Tunisia), a considerable improvement of the situation of the telecommunication operators has been noticed during the nineties. The evolution in these countries was very different depending on their economic policies, their effort of reorganization of their telecommunication sector and their technological change. Theses differences will be exhibited and analysed by comparing the operators’ performances over a decade (1992–2001). A first approach is based on the Malmquist DEA TFP index for measuring the total factors productivity change, decomposed into technical efficiency change and technological changes. Second, using the Promethee II method and the software ARGOS, a multiple criteria analysis is performed, taking into account a larger scope of analysis. A main issue is that the general performance ranking of sets of operators by country is almost the same according to the two methods, although the variables of inputs and output used for the index of Malmquist are different and narrower in the considered scope than the chosen families of criteria used in method Promethee and software ARGOS. Both methods of analysis provide however complementary useful detailed information, especially in discriminating the technological and management progresses for Malmquist and the two dimensions of performance for Promethee: that are the service to the community and the enterprises performances, often in conflict. [less ▲]

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See detailMultiple Description Coding versus Transport Layer FEC for Resilient Video Transmission
Soldani, Cyril ULg; Verdicchio, Fabio; Leduc, Guy ULg et al

(2006, August)

Video content delivery is a challenging task due to its large bandwidth requirements and its sensitivity to transmission errors. In this context, simultaneously providing scalability and resilience ... [more ▼]

Video content delivery is a challenging task due to its large bandwidth requirements and its sensitivity to transmission errors. In this context, simultaneously providing scalability and resilience against transmission errors is of paramount importance. Layered video coding coupled with multicast video transmission employing no feedback provides the required scalability features and reduces the network burden. However, it is not easy to provide reliability in such environments. This is crucial to mobile users as error rates on wireless links can be high. To compensate for transmission errors, redundancy must be added to the video content. This can be added at the application layer by the employed video coding system, or can be added transparently by the transport layer. In this paper, we compare the performance obtained with a scalable wavelet-based video codec that adds redundancy using multiple description coding with the equivalent system adding redundancy at the transport level, using forward error correction. [less ▲]

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See detailMultiple domains of the glucocorticoid receptor involved in synergism with the CACCC box factor(s).
Muller, Marc ULg; Baniahmad, C.; Kaltschmidt, C. et al

in Molecular Endocrinology (Baltimore, Md.) (1991), 5(10), 1498-503

Steroid induction of responsive genes functions through the synergistic activity of steroid receptor-binding sequences with adjacent transcription factor-binding sites. To analyze the mechanism of synergy ... [more ▼]

Steroid induction of responsive genes functions through the synergistic activity of steroid receptor-binding sequences with adjacent transcription factor-binding sites. To analyze the mechanism of synergy we tested different human glucocorticoid receptor mutants for synergistic function with another transcription factor in comparison with intrinsic trans-activation obtained with a single receptor binding site (glucocorticoid response element). Multiple domains were found to be involved in synergistic activity of the glucocorticoid receptor with the CACCC box factor. Deletions within the N-terminal receptor half affected simultaneously intrinsic trans-activation and synergism. However, deletion of the hormone-binding domain mainly impaired synergism rather than intrinsic trans-activation, clearly showing that this domain synergizes by a mechanism independent of intrinsic activation. A chimeric protein where the DNA-binding domain of the glucocorticoid receptor was replaced by that of the yeast GAL4 protein also showed functional synergism. These data suggest that some of the receptor domains outside the DNA-binding domain synergize by their intrinsic trans-activating property, but the hormone-binding domain contributes to synergism by a different mechanism. [less ▲]

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See detailMultiple Endocrine Neoplasia 1 : From the clinic to the gene
Beckers, Albert ULg

Scientific conference (1998, January 30)

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See detailMultiple Endocrine Neoplasia, type 1
Beckers, Albert ULg

Scientific conference (2001, February 09)

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See detailMultiple exposure holographic interferometry with sillenite crystals applied to vibration measurement
Georges, Marc ULg; Thizy, Cédric ULg; Lemaire, Philippe ULg et al

in Nolte, D.; Salamo, G.; Siahmakoun, A. (Eds.) et al Photorefractive Effects, Materials, and Devices (2001, July)

A holographic camera is presented, which uses a sillenite crystal as dynamic recording medium. The camera operates in a pulse regime and is used to provide vibration analysis of an object. A 4 pulse real ... [more ▼]

A holographic camera is presented, which uses a sillenite crystal as dynamic recording medium. The camera operates in a pulse regime and is used to provide vibration analysis of an object. A 4 pulse real-time holographic technique was implemented to measure the amplitude and phase of the vibration. The implementation of this technique required bringing under control a Q-switched YAG laser. We present the experimental results for a metallic plate driven by a vibrating loud speaker. [less ▲]

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See detailMultiple feedback loops in circadian cycles: robustness and entrainment as selection criteria
Hafner, Marc; Sacré, Pierre ULg; Symul, Laura et al

in Proceedings of the Seventh International Workshop on Computational Systems Biology, WCSB 2010 (2010, June)

This paper discusses the contribution of an additional feedback loop to the entrainment and the robustness of a circadian system. To quantify robustness, we perform a global analysis of the system's ... [more ▼]

This paper discusses the contribution of an additional feedback loop to the entrainment and the robustness of a circadian system. To quantify robustness, we perform a global analysis of the system's parameter space. We quantify the parameter region where the circuit displays an experimentally observed behavior, under entrainment. This global measure is comleted with a classification based on the phase response curve (PRC). For two models of circadian rhythms, we found that the one with two loops is more robust than the one with a single loop: the two-loop model shows better resilience to parameter perturbations and it has also a larger region where the PRC matches experimental PRCs of circadian oscillators. [less ▲]

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See detailMultiple fMRI system-level baseline connectivity is disrupted in patients with consciousness alterations
Demertzi, Athina ULg; Gomez, Francisco; Crone, Julia-Sophia et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2014), 52

Introduction: In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the tennetwork model in severely ... [more ▼]

Introduction: In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the tennetwork model in severely brain-injured patients suffering from disorders of consciousness and to identify those networks which will be most relevant to discriminate between patients and healthy subjects. Methods: 300 fMRI volumes were obtained in 27 healthy controls and 53 patients in minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/ UWS) and coma. Independent component analysis (ICA) reduced data dimensionality. The ten networks were identified by means of a multiple template-matching procedure and were tested on neuronality properties (neuronal vs non-neuronal) in a data-driven way. Univariate analyses detected between-group differences in networks’ neuronal properties and estimated voxel-wise functional connectivity in the networks, which were significantly less identifiable in patients. A nearest-neighbor “clinical” classifier was used to determine the networks with high between-group discriminative accuracy. Results: Healthy controls were characterized by more neuronal components compared to patients in VS/UWS and in coma. Compared to healthy controls, fewer patients in MCS and VS/UWS showed components of neuronal origin for the left executive control network, default mode network (DMN), auditory, and right executive control network. The “clinical” classifier indicated the DMN and auditory network with the highest accuracy (85.3%) in discriminating patients from healthy subjects. [less ▲]

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

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

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

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

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See detailMultiple functional variants at the 3p21 locus contribute to ulcerative colitis: Results from a European consortium
Cleynen, I; Artieda, M; Verspaget, H et al

in Journal of Crohn’s and Colitis [=JCC] (2012)

Detailed reference viewed: 13 (2 ULg)