References of "2012"
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See detailDu bon usage des catastrophes, de Régis Debray
Thoreau, François ULg

in Revue Nouvelle (2012), 66(2), 74-77

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See detailIdentifying and computing nonlinear normal modes
Cammarano, A.; Carrella, A.; Renson, Ludovic ULg et al

in Proceedings of the SEM IMAC XXX Conference (2012, February)

Non linear normal modes offer a rigorous framework, both mathematical and physical, for theoretical and experimental dynamical analysis. Albeit still in its infancy, the concept of non linear normal modes ... [more ▼]

Non linear normal modes offer a rigorous framework, both mathematical and physical, for theoretical and experimental dynamical analysis. Albeit still in its infancy, the concept of non linear normal modes has the potential of providing to both the academic and the industrial establishment a powerful tool for the analysis of non linear dynamical systems. However, in order to exploit the full potential of this theory (and its associated simulation capability), there is need to integrate it with other branches of non linear structural dynamics: namely, in order for the non linear normal modes of a real - physical - structure to be computed, there is need to identify and quantify its non linearity. In this paper, an identification method based on the measured Frequency Response Function (FRF) is employed to identify and quantify the system's non linearity before computing the system's non linear normal modes. [less ▲]

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See detailA non-linear homogeneous model for bone-like materials under compressive load.
Mengoni, Marlène ULg; Voide, Romain; de Bien, Charlotte ULg et al

in International Journal for Numerical Methods in Biomedical Engineering (2012), 28(2), 334-348

Finite element (FE) models accurately compute the mechanical response of bone and bone-like materials when the models include their detailed microstructure. In order to simulate non-linear behavior, which ... [more ▼]

Finite element (FE) models accurately compute the mechanical response of bone and bone-like materials when the models include their detailed microstructure. In order to simulate non-linear behavior, which currently is only feasible at the expense of extremely high computational costs, coarser models can be used if the local morphology has been linked to the apparent mechanical behavior. The aim of this paper is to implement and validate such a constitutive law. This law is able to capture the non-linear structural behavior of bone-like materials through the use of fabric tensors. It also allows for irreversible strains using an elastoplastic material model incorporating hardening. These features are expressed in a constitutive law based on the anisotropic continuum damage theory coupled with isotropic elastoplasticity in a finite strains framework. This material model was implemented into Metafor, a non-linear FE software. The implementation was validated against experimental data of cylindrical samples subjected to compression. Three materials with bone-like microstructure were tested : aluminum foams of variable density (ERG, Oakland, CA), PLA (polylactic acid) foam (CERM, University of Liège) and cancellous bone tissue of a deer antler (Faculty of Veterinary Medicine, University of Liège). [less ▲]

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See detailComparing vertical ground heat exchanger models
Bertagnolio, Stéphane ULg; Bernier, Michel; Kummert, Michaël

in Journal of Building Performance Simulation [=JBPS] (2012)

The main objective of this article is to establish a set of test cases for analytical verification and inter-model comparison of vertical ground heat exchanger (GHX) models used in building simulation ... [more ▼]

The main objective of this article is to establish a set of test cases for analytical verification and inter-model comparison of vertical ground heat exchanger (GHX) models used in building simulation programs. Several test cases are suggested. They range from steady-state heat rejection in a single borehole to varying hourly loads with relatively large yearly thermal imbalance in multiple borehole configurations. The usefulness of the proposed test cases is illustrated with different GHX models. This comparison exercise has shown that analytical one-dimensional (1D) models compare favourably well with three-dimensional (3D) models for relatively short-simulation periods, where axial effects are not significant. Cyclic heat rejection/collection tests proved to be useful to characterize the accuracy and the computational performance of different load aggregation algorithms. Finally, different spatial superposition methods have been compared for various bore field sizes and configurations and various loads. [less ▲]

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See detailLe portail de Mont-devant-Sassey : aspects iconographiques
Lekane, Marie ULg

in Conroy, Jean-François (Ed.) Actes du 11ème colloque international étudiant du Département d'histoire de l'Université Laval (2012, February)

Le portail sculpté méridional de Mont-devant-Sassey est intéressant à plus d’un titre. Premièrement, il est le portail gothique lorrain le mieux conservé qui soit, comme la critique d’authenticité le ... [more ▼]

Le portail sculpté méridional de Mont-devant-Sassey est intéressant à plus d’un titre. Premièrement, il est le portail gothique lorrain le mieux conservé qui soit, comme la critique d’authenticité le confirme. Ensuite, certains des choix iconographiques effectués par le « commanditaire » sont surprenants, inusités, voire inédits. Enfin, en raison de sa situation géographique char- nière entre le domaine français et l’Empire germanique, les sculpteurs ont pu profiter des innovations sculpturales introduites tant à l’ouest qu’à l’est et les combiner de manière originale. Le présent article est l’occasion de renouveler l’identification iconographique de certaines figures, de proposer une datation de l’ensemble et de suggérer les transferts artistiques attestés par le portail (réception de formules iconographiques et stylistiques mises en place dans des grands centres). [less ▲]

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See detailRetour d'expérience sur la plate-forme créative du LUCID-ULg
Leclercq, Pierre ULg

in Llerena, Daniel; Rieu, Dominique (Eds.) Innovation Connaissances et Société - Vers une société de l'innovation (2012)

Ce chapitre est consacré à la présentation d'une unité de recherche universitaire originale, appelée le LUCID, créé en 2001 à l'Université de Liège (Belgique). Elle figure ici comme une expérience ... [more ▼]

Ce chapitre est consacré à la présentation d'une unité de recherche universitaire originale, appelée le LUCID, créé en 2001 à l'Université de Liège (Belgique). Elle figure ici comme une expérience partagée, créée autour de la notion d'innovation et menée avec une approche pluridisciplinaire centrée utilisateur et articulée autour des nouvelles technologies. Dès sa fondation, cette petite structure, très dynamique, a développé un savoir-faire spécifique, rapidement remarqué dans le domaine de l'ingénierie de conception, qui lui vaut d'être régulièrement citée et appelée à participer à des projets innovants. Parallèlement à ses projets, elle conduit une réflexion sur ses propres processus de création qu'elle cherche sans cesse à maîtriser et à diversifier. A l'invitation de l'Institut de l'Innovation INNOVACS de Grenoble, c'est une synthèse de cette analyse qui est proposée ici dans une perspective pratique, pas nécessairement reproductible mais potentiellement porteuse pour celles et ceux qui s'interrogent sur les méthodes opérationnelles de gestion de l'innovation. Ce chapitre est articulé en trois parties. Il présente d'abord l'équipe et quelques-uns de ses projets; il montre ensuite comment elle s'est organisée en termes de ressources humaines et logistiques; enfin, il propose une analyse rétroactive, permettant d'inspirer éventuellement d'autres contextes. [less ▲]

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See detailTime-domain surface impedance boundary conditions enhanced by coarse volume finite-element discretisation
Vazquez Sabariego, Ruth ULg; Geuzaine, Christophe ULg; Dular, Patrick ULg et al

in IEEE Transactions on Magnetics (2012), 48(2), 631-634

In computational magnetodynamics, surface impedance boundary conditions allow to accurately account for high-frequency flux components while removing the massive conducting regions from the computation ... [more ▼]

In computational magnetodynamics, surface impedance boundary conditions allow to accurately account for high-frequency flux components while removing the massive conducting regions from the computation domain. The time-domain approach previously proposed by the authors relies on the spatial discretisation of a 1-D eddy-current problem by means of dedicated basis functions derived from the analytical frequency-domain solution. In this paper, these time-domain impedance conditions are combined with a coarse volume finite-element discretisation of the massive conductors to capture slowly varying flux components. The accuracy of the hybrid approach can further be improved by introducing a fictitious frequency-dependent conductivity. The method is illustrated and validated by means of 1-D and 2-D test cases in the frequency and time domain. [less ▲]

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See detailCOMBINATION OF INDEPENDENT COMPONENT ANALYSIS, DESIGN OF EXPERIMENTS AND DESIGN SPACE FOR A NOVEL METHODOLOGY TO DEVELOP CHROMATOGRAPHIC METHODS
Rozet, Eric ULg; Debrus, Benjamin ULg; Lebrun, Pierre ULg et al

Poster (2012, February)

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process ... [more ▼]

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process control, based on sound science and quality risk management”. A risk–based QbD–compliant approach is proposed for the robust development of analytical methods. This methodology based on Design of Experiments (DoE) to study the experimental domain models the retention times at the beginning, the apex and the end of each peak corresponding to the compounds of a mixture and uses the separation criterion (S) rather than the resolution (RS) as a Critical Quality Attribute. Stepwise multiple linear regressions are used to create the models. The estimated error is propagated from the modelled responses to the separation criterion (S) using Monte Carlo simulations in order to estimate the predictive distribution of the separation criterion (S) over the whole experimental domain. This allows finding ranges of operating conditions that will guarantee a satisfactory quality of the method in its future use. These ranges define the Design Space (DS) of the method. In chromatographic terms, the chromatograms processed at operating conditions within the DS will assuredly show high quality, with well separated peaks and short run time, for instance. This Design Space can thus be defined as the subspace, necessarily encompassed in the experimental domain (i.e. the knowledge space), within which the probability for the criterion to be higher than an advisedly selected threshold is higher than a minimum quality level. Precisely, the DS is defined as “the multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality” [1]. Therefore, this DS defines a region of operating conditions that provide prediction of assurance of quality rather than only quality as obtained with traditional mean response surface optimisation strategies. For instance, in the liquid chromatography there is a great difference in e.g. predicting a resolution (RS) higher than 1.5 vs. predicting that the probability for RS to be higher than 1.5 (i.e. P(RS> 1.5)) is high. The presentation of this global methodology will be illustrated for the robust optimisation and DS definition of several liquid chromatographic methods dedicated to the separation of different mixtures: pharmaceutical formulations, API and impurities/degradation products, plant extracts, separation of enantiomers, … References [1] International Conference on Harmonisation (ICH) of Technical Requirements for Registration of Pharmaceuticals for Human Use, Topic Q8(R2): Pharmaceutical development, Geneva, 2009. [less ▲]

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See detailScales of spatial and temporal variations in Cryptosporidium and Giardia abundances and genetic diversity in a drinking water reservoir: implications for the risk assessment
Cauchie, Henry-Michel ULg; Burnet, Jean-Baptiste; Ogorzaly, Leslie et al

Conference (2012, February)

A monitoring of Giardia lamblia and Cryptosporidium parvum occurrence was conducted for 2 years in the largest drinking water reservoir of Luxembourg (Esch-sur-Sûre reservoir) using microscopy and qPCR ... [more ▼]

A monitoring of Giardia lamblia and Cryptosporidium parvum occurrence was conducted for 2 years in the largest drinking water reservoir of Luxembourg (Esch-sur-Sûre reservoir) using microscopy and qPCR techniques. Parasite analyses were performed on water samples collected from three sites: site A located at the inlet of the reservoir, site B located 18 km downstream site A, at the inlet of the drinking water treatment plant near the dam of the reservoir and site C where the finished drinking water is injected in the distribution network. The communication presented the main results of the survey and the assessment of risk infection with parasites. [less ▲]

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See detailUne introduction à la nouvelle vague. Parcours croisés de François Truffaut et Jean-Luc Godard
Tomasovic, Dick ULg

Conference given outside the academic context (2012)

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See detailIMPROVE SHIP DESIGN COMPLEXITY (EASYSHIP)
Hage, André ULg; Rigo, Philippe ULg; Caprace, Jean-David ULg

Report (2012)

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the ... [more ▼]

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the productibility of ships, the scientific community and shipyards has developed the concept of Design For Production (DFP) which can be defined as "Design to reduce production costs to a minimum, compatible with the requirements of the vessel to fulfil its operational functions with acceptable safety, reliability and efficiency". DFP optimises all the manufacturing functions (fabrication, assembly, test, procurement, delivery, service, repair, etc.) that reduce the production work content while still meeting the specified design requirements and quality. The goal is to include the impact of design decisions on the production process. Time pressures on commercial ship contracts result in the overlapping of phases of design development, procurement and production. This makes the impact of engineering changes more difficult to manage. There is a need to systematically study the detail design process and its impact on construction with the objective to improve the process and its integration with construction. DFP can significantly reduce the costs, since ships can be quickly assembled from fewer parts. Thus, ships are easier to build and assemble, in less time, with better quality. Designers will save time and money by the reduction of the production complexity. [less ▲]

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See detailLearning to play K-armed bandit problems
Maes, Francis ULg; Wehenkel, Louis ULg; Ernst, Damien ULg

in Proceedings of the 4th International Conference on Agents and Artificial Intelligence (ICAART 2012) (2012, February)

We propose a learning approach to pre-compute K-armed bandit playing policies by exploiting prior information describing the class of problems targeted by the player. Our algorithm first samples a set of K ... [more ▼]

We propose a learning approach to pre-compute K-armed bandit playing policies by exploiting prior information describing the class of problems targeted by the player. Our algorithm first samples a set of K-armed bandit problems from the given prior, and then chooses in a space of candidate policies one that gives the best average performances over these problems. The candidate policies use an index for ranking the arms and pick at each play the arm with the highest index; the index for each arm is computed in the form of a linear combination of features describing the history of plays (e.g., number of draws, average reward, variance of rewards and higher order moments), and an estimation of distribution algorithm is used to determine its optimal parameters in the form of feature weights. We carry out simulations in the case where the prior assumes a fixed number of Bernoulli arms, a fixed horizon, and uniformly distributed parameters of the Bernoulli arms. These simulations show that learned strategies perform very well with respect to several other strategies previously proposed in the literature (UCB1, UCB2, UCB-V, KL-UCB and $\epsilon_n$-GREEDY); they also highlight the robustness of these strategies with respect to wrong prior information. [less ▲]

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See detailJames McAuley
Delrez, Marc ULg

Article for general public (2012)

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See detailDoes pupil constriction under blue and green monochromatic light exposure change with age?
Daneault, V; Vandewalle, Gilles ULg; Hébert, M et al

Poster (2012, February)

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See detailDifferential proteomic analysis of a human breast tumor and its matched bone metastasis identifies cell membrane and extracellular proteins associated with bone metastasis
Dumont, Bruno ULg; Castronovo, Vincenzo ULg; Peulen, Olivier ULg et al

in Journal of Proteome Research (2012)

The classical fate of metastasizing breast cancer cells is to seed and form secondary colonies in bones. The molecules closely associated with these processes are predominantly present at the cell surface ... [more ▼]

The classical fate of metastasizing breast cancer cells is to seed and form secondary colonies in bones. The molecules closely associated with these processes are predominantly present at the cell surface and in the extracellular space, establishing the first contacts with the target tissue. In this study, we had the rare opportunity to analyze a bone metastatic lesion and its corresponding breast primary tumor obtained simultaneously from the same patient. Using mass spectrometry, we undertook a proteomic study on cell surface and extracellular protein-enriched material. We provide a repertoire of significantly modulated proteins, some with yet unknown roles in the bone metastatic process as well as proteins notably involved in cancer cell invasiveness and in bone metabolism. The comparison of these clinical data with those previously obtained using a human osteotropic breast cancer cell line highlighted an overlapping group of proteins. Certain differentially expressed proteins are validated in the present study using immunohistochemistry on a retrospective collection of breast tumors and matched bone metastases. Our exclusive set of selected proteins supports the set-up of further investigations on both clinical samples and experimental bone metastasis models that will help to reveal the finely coordinated expression of proteins that favor the development of metastases in the bone microenvironment. [less ▲]

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See detailMicroorganisms from aphid honeydew attract natural enemies and tending ants
Verheggen, François ULg; Leroy, Pascal; Fischer, Christophe ULg et al

Conference (2012, February)

Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and ... [more ▼]

Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and hoverflies) to be able to use aphid volatile chemicals to locate aphid colonies. Here, we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which produces kairomones used by the aphidophagous hoverfly Episyrphus balteatus and the Asian Ladybeetle Harmonia axyridis during their search for prey colonies. Some specific semiochemicals produced by S. sciuri were identified as attractants and ovipositional stimulants. Similarly, we have shown scouts of the aphid tending ant species, Lasius niger, to orientate their foraging behaviour toward an Aphis fabae infested plant and we have demonstrated that the odours released by this aphid honeydew were attractive for ant scouts. Again, bacteria were involved in the production of these honeydew semiochemicals. Interestingly, ant scouts were also able to discriminate honeydew odour from A. fabae (usually attended by L. niger) and A. pisum (unattendedby L. niger). Comparison of the volatile and bacteria composition of both aphid species honeydew were attended. [less ▲]

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