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See detailThe Harmonic Balance Method for Bifurcation Analysis of Nonlinear Mechanical Systems
Detroux, Thibaut ULg; Renson, Ludovic ULg; Masset, Luc ULg et al

in Proceedings of the SEM IMAC XXXIII (2015)

Because nowadays structural engineers are willing to use or at least understand nonlinearities instead of simply avoiding them, there is a need for numerical tools performing analysis of nonlinear large ... [more ▼]

Because nowadays structural engineers are willing to use or at least understand nonlinearities instead of simply avoiding them, there is a need for numerical tools performing analysis of nonlinear large-scale structures. Among these techniques, the harmonic balance (HB) method is certainly one of the most commonly used to study finite element models with reasonably complex nonlinearities. However, in its classical formulation the HB method is limited to the approximation of periodic solutions. For this reason, the present paper proposes to extend the method to the detection and tracking of codimension-1 bifurcations in the system parameters space. As an application, the frequency response of a spacecraft is studied, together with two nonlinear phenomena, namely quasiperiodic oscillations and detached resonance curves. This example illustrates how bifurcation tracking using the HB method can be employed as a promising design tool for detecting and eliminating such undesired behaviors. [less ▲]

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See detailCan meandering flows in shallow rectangular reservoir be modelled with the 2D shallow water equations?
Peltier, Yann ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Journal of Hydraulic Engineering (2015)

In this article, the ability of the 2D shallow water equations to model meandering flows in shallow rectangular reservoirs is discussed. Four meandering flows, of various shallowness, were modelled using ... [more ▼]

In this article, the ability of the 2D shallow water equations to model meandering flows in shallow rectangular reservoirs is discussed. Four meandering flows, of various shallowness, were modelled using the academic flow model WOLF 2D, which includes a depth-averaged k- model accounting for the horizontal and vertical turbulent length-scales. The bottom friction was modelled with the Colebrook-White formula and different roughness heights were considered. A Proper Orthogonal Decomposition (POD) was applied to the simulation results to extract the behaviour of the main structures responsible for the meandering flow. The same POD analysis was also performed for the reference experimental flow fields, obtained by Large-Scale Particle Image Velocimetry. The first two POD modes obtained from the numerical simulations assuming a smooth bottom are in good agreement with the experimental modes in terms of energy, as well as temporal and spatial variations, whatever the shallowness. In contrast, the remaining simulated modes are not well rendered. The effect of an increased roughness height in the simulations is finally discussed. It leads to an improved reproduction of the first two modes and of the following modes, except when significant viscous effects govern in the flow. [less ▲]

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See detailVoyage(s) à travers le thymus
Geenen, Vincent ULg

Book published by Presses ULg (2015)

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See detailComparative biogeochemistry-ecosystem-human interactions on dynamic continental margins
Levin, Lisa A.; Liu, Kon-Kee; Kay-Christian, Emeis et al

in Journal of Marine Systems (2015), 141

The ocean’s continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions ... [more ▼]

The ocean’s continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1) provide an overview of the drivers of biogeochemical variation and change on margins, (2) compare temporal trends in hydrographic and biogeochemical data across different margins (3) review ecosystem responses to these changes, (4) highlight the importance of margin time series for detecting and attributing change and (5) examine societal responses to changing margin biogeochemistry and ecosystems. We synthesize information over a wide range of margin settings in order to identify the commonalities and distinctions among continental margin ecosystems. Key drivers of biogeochemical variation include long-term climate cycles, CO2-induced warming, acidification, and deoxygenation, as well as sea level rise, eutrophication, hydrologic and water cycle alteration, changing land use, fishing, and species invasion. Ecosystem responses are complex and impact major margin services including primary production, fisheries production, nutrient cycling, shoreline protection, chemical buffering, and biodiversity. Despite regional differences, the societal consequences of these changes are unarguably large and mandate coherent actions to reduce, mitigate and adapt to multiple stressors on continental margins. [less ▲]

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See detailThe neural basis of temporal order processing in past and future thought
D'Argembeau, Arnaud ULg; Jeunehomme, Olivier ULg; Majerus, Steve ULg et al

in Journal of Cognitive Neuroscience (2015), 27

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See detailDilthey et l'empirisme psychologique
Dewalque, Arnaud ULg

in Camilleri, Sylvain; Fagniez, Guillaume (Eds.) Dilthey et l'histoire (2015)

Je discute ici le projet diltheyen d'une "fondation psychologique des sciences de l'esprit". Je suggère que ce projet peut être rapproché d’un certain programme épistémologique baptisé "empirisme ... [more ▼]

Je discute ici le projet diltheyen d'une "fondation psychologique des sciences de l'esprit". Je suggère que ce projet peut être rapproché d’un certain programme épistémologique baptisé "empirisme psychologique". L’hypothèse qui se trouve à la base de l’empirisme psychologique est la suivante : l’expérience interne, psychologique, est la source des concepts au moyen desquels nous pouvons penser et connaître le monde. Après avoir brièvement reconstruit le programme diltheyen en ce sens, j'examine deux objections qui ont été soulevées contre lui: l'objection néokantienne (Windelband, Rickert) et l'objection psychologique (Ebbinghaus, Stumpf). La seconde, selon moi, met en évidence une difficulté réelle du projet de Dilthey: la "connexion structurelle de la vie" dans sa totalité peut difficilement être considérée comme "donnée" dans l'expérience interne, ainsi que l'affirme Dilthey. Je soutient donc que le programme de l'empirisme psychologique peut être poursuivi à condition de le débarrasser de cette thèse problématique. [less ▲]

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See detailInvolvement of the Distinctiveness Heuristic in Children's Decision Making
Geurten, Marie ULg; Willems, Sylvie ULg; Meulemans, Thierry ULg

in International Convention of Psychological Science: ICPS, Amsterdam 2015 (2015)

Over the past decades, researchers studying adult metacognition have placed a heavy emphasis on how expectations and naïve theories about memory functioning can improve memory accuracy through the ... [more ▼]

Over the past decades, researchers studying adult metacognition have placed a heavy emphasis on how expectations and naïve theories about memory functioning can improve memory accuracy through the implementation of some metacognitive rules. By contrasts, however, research on metacognition in children has only recently started to pay attention to the influence of these heuristic-based judgments on decision making. Generally, the results of these studies indicate that memory decisions are already based on some heuristics by the ages of 7-8 years. Thus far, the question of whether younger children can do the same has widely gone unexamined. The present experiment investigates whether young children are able to reduce their false recognitions rate after distinctive encoding through the implementation of a strategic metacognitive rule. Specifically, we examine the use of a retrieval strategy called the distinctiveness heuristic whereby people infer that an event has not occurred when they cannot remember expected memorial information about it. Seventy-two children, aged 4, 6, and 9 years, studied two lists of unrelated items. One of these lists was visually displayed (picture/dictinctive condition) while the other was presented auditorily (word/no-distinctive condition). After each study phase, participants completed recognition tests. Finally, they answered questions about their explicit knowledge of the distinctive-encoding effect. The results revealed that even the youngest children in our sample showed a smaller proportion of intrusions in the picture condition than in the word condition. Furthermore, the findings of the signal detection analyses are consistent with the hypothesis that the lower rate of false recognitions after picture encoding results from the implementation of a conservative response criterion based on the participants’ metacognitive expectations (distinctiveness heuristic). Moreover, the absence of correlation between children’s explicit knowledge of the distinctiveness rule and their effective use of this metacognitive heuristic seems to indicate that its involvement in memory decisions could be mediated by implicit mechanisms. [less ▲]

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See detailSupervised inference of biological networks with trees : Application to genetic interactions in yeast
Schrynemackers, Marie ULg

Doctoral thesis (2015)

Networks or graphs provide a natural representation of molecular biology knowledge, in particular to model relationships between biological entities such as genes, proteins, drugs, or diseases. Because of ... [more ▼]

Networks or graphs provide a natural representation of molecular biology knowledge, in particular to model relationships between biological entities such as genes, proteins, drugs, or diseases. Because of the effort, the cost, or the lack of the experiments necessary to the elucidation of these networks, computational approaches for network inference have been frequently investigated in the literature. In this thesis, we focus on supervised network inference methods. These methods exploit supervised machine learning algorithms to train a model for identifying new interacting pairs of nodes from a training sample of known interacting and possibly non-interacting pairs and additional measurement data about the network nodes. Our contributions in this area are divided into three parts. First, the thesis examines the problem of the assessment of supervised network inference methods. Indeed, their reliable validation (in silico) poses a number of new challenges with respect to standard classification problems, related to the fact that pairs of objects are to be classified and to the specificities of biological networks. We perform a critical review and assessment of protocols and measures proposed in the literature. Through theoretical considerations and in silico experiments, we analyze in depth how important factors influence the outcome of performance estimation. These factors include the amount of information available for the interacting entities, the sparsity and topology of biological networks, and the lack of experimentally verified non-interacting pairs. From this analysis, we derived specific guidelines so as to how best exploit and evaluate machine learning techniques for network inference. Second, we systematically investigate, theoretically and empirically, the exploitation of tree- based methods for network inference. We consider these methods in the context of the two main generic classification-based approaches for network inference: the local approach, which trains a separate model for each network node, and the global approach, which trains a single model over pairs of nodes. We present and formalize these two approaches, extending the former for the prediction of interactions between two unseen network nodes, and discuss their specializations to tree-based methods, highlighting their interpretability and drawing links with clustering techniques. Extensive experiments are carried out with these methods on various biological networks that clearly highlight that these methods are competitive with existing methods. The interpretability of the resulting method family is illustrated on a drug-protein interaction network. In the last part of the thesis, we built on the experience gained in the two previous parts to try to predict at best the genetic interaction network in yeast S.cerevisiae. For that purpose, we collected a large dataset, assembling 4 millions gene pairs that were experimentally tested in the context of 11 different studies and 23 sets of measurements to use as gene input features for the inference. Through several cross-validation experiments on the resulting dataset, we showed that predicting genetic interactions is indeed possible to some useful extent and that actually in some settings, the accuracy of computational methods is not very far from that of experimental techniques. [less ▲]

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See detailConcept et perception
Gauvry, Charlotte ULg; Brisart, Robert

Book published by Olms (2015)

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See detailIntroduction
Fallon, Catherine ULg

in Albarello, Luc; Fallon, Catherine; Van Haeperen, Beatrice (Eds.) Evaluation des politiques publiques (2015)

Ce livre s’adresse à toutes les personnes qui a des titres divers sont concernés par l’évaluation des politiques publiques parce qu’ils doivent en assurer la réalisation ou en encadrer la démarche. Les ... [more ▼]

Ce livre s’adresse à toutes les personnes qui a des titres divers sont concernés par l’évaluation des politiques publiques parce qu’ils doivent en assurer la réalisation ou en encadrer la démarche. Les exemples et les angles de discussion sont les plus larges possibles pour que le lecteur puisse s’approprier les outils quel que soit son secteur de responsabilité et quel que soit son territoire. Il trouvera dans la suite des chapitres non pas un livre de recettes – ce qui nous semble contraire à la logique d’évaluation de politiques – mais des cadres de réflexion, des propositions de pratiques, ainsi que des références complémentaires pour développer ses pratiques tout en mobilisant un regard critique. [less ▲]

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See detailDes chiffres de la politique à la politique du chiffre Le cas des réformes du financement de la recherche dans les universités belge francophones.
Fallon, Catherine ULg

in Reflets et Perspectives de la Vie Economique (2015)

“Governing by numbers” is a trend on the increase in public action. Numbers tend to pervade the politico-administrative space without questioning neither the quantification processes which produce them ... [more ▼]

“Governing by numbers” is a trend on the increase in public action. Numbers tend to pervade the politico-administrative space without questioning neither the quantification processes which produce them nor the conditions of their utilization in government. And yet the use of numbers and data in political arguments contribute to transform the terms of the debate: politics can transform data and indicators, but one should not neglect how numbers affect policymaking. This article proposes as case study the analysis of some recent transformations of public research funding mechanism in universities in French speaking Belgium. It questions the systemic effects of the use of performance indicators in public management in this sector and it proposes some starting points for a discussion of their impact on the quality of the political debate. [less ▲]

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See detailGiven to a Deity? Religious and Social Reappraisal of Human Consecrations in the Hellenistic and Roman East
Caneva, Stefano ULg; Delli Pizzi, Aurian ULg

in Classical Quarterly (2015)

Various cases of human beings ‘dedicated’ to deities are attested in Greek epigraphic evidence. Are these kinds of offerings comparable to the dedication of inanimate objects? Besides, does the fact that ... [more ▼]

Various cases of human beings ‘dedicated’ to deities are attested in Greek epigraphic evidence. Are these kinds of offerings comparable to the dedication of inanimate objects? Besides, does the fact that someone is said to be ‘sacred’ to a specific deity necessarily involve that he went through a process of dedication? This article aims at providing a global picture of different situations in which processes of dedications took place. Among the several issues that are tackled, the cornerstone of this article consists of two questions: for what purposes did some people decide to consecrate a human being to a deity and what were the consequences for the consecrated individuals on religious and social levels? Different categories of persons will be contrasted, in terms of processes through which they acquire their new status but also in terms of the freedom/lack of freedom which is conveyed by this new status. It will also be shown that, as far as method is concerned, it is necessary to complete a lexical analysis with a contextual perspective for a deeper understanding of the problem. [less ▲]

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See detailAn original solver for spillway flow
Goffin, Louis ULg; Erpicum, Sébastien ULg; Dewals, Benjamin ULg et al

Poster (2015)

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See detailQuantitative temperature monitoring of a heat tracing experiment using cross-borehole ERT
Hermans, Thomas ULg; Wildemeersch, Samuel ULg; Jamin, Pierre ULg et al

in Geothermics (2015), 53

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal ... [more ▼]

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal systems requires a multidisciplinary approach including geological and hydrogeological aspects. In this context, electrical resistivity tomography (ERT) can bring relevant, qualitative and quantitative information on the temperature distribution in operating shallow geothermal systems or during heat tracing experiments. We followed a heat tracing experiment in an alluvial aquifer using cross-borehole time-lapse ERT. Heated water was injected in a well while water of the aquifer was extracted at another well. An ERT section was set up across the main flow direction. The results of ERT were transformed into temperature using calibrated petrophysical relationships. These ERT-derived temperatures were then compared to direct temperature measurements in control piezometers collected with distributed temperature sensing (DTS) and groundwater temperature loggers. Spatially, it enabled to map the horizontal and vertical extent of the heated water plume, as well as the zones where maximum temperatures occurred. Quantitatively, the temperatures and breakthrough curves estimated from ERT were in good agreement with the ones observed directly during the rise and maximum of the curve. An overestimation, likely related to 3D effects, was observed for the tail of the heat breakthrough curve. The error made on temperature can be estimated to be between 10 to 20 %, which is a fair value for indirect measurements. From our data, we estimated a quantification threshold for temperature variation of 1.2°C. These results suggest that ERT should be considered when designing heat tracing experiments or geothermal systems. It could help also to assess the geometrical complexity of the concerned reservoirs. It also appears that ERT could be a useful tool to monitor and control geothermal systems once they are in operation. [less ▲]

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See detailUsing zero-inlated models to predict the relative distribution and abundance of roe deer over very large spatial scales
Bouyer, Yaëlle ULg; Rigot, Thibaud; Panzacchi, Manuela et al

in Annales Zoologici Fennici (2015), 52

In Norway, recovering populations of large carnivores commonly prey on roe deer (Capreolus capreolus). Understanding predator habitat use and ecology requires fine-scaled information on prey distribution ... [more ▼]

In Norway, recovering populations of large carnivores commonly prey on roe deer (Capreolus capreolus). Understanding predator habitat use and ecology requires fine-scaled information on prey distribution and abundance. However, the massive spatial scales at which large carnivores use the landscape presents many practical and statistical challenges for developing functional prey distribution models. Pellet-count data from >1000 km of transects gathered across southeastern Norway from 2005 to 2011 were used to derive a map of relative prey abundance for roe deer. These data were modeled using zero-inflated hurdle models using both environmental and anthropogenic variables. Snow depth and agricultural fields were the most significant variables in explaining both presence and abundance. Internal k-cross validation of the model showed medium accuracy (Spearman r = 0.35), whereas external evaluation carried out on the basis of independently collected snow-tracking data (Spearman r = 0.37) and hunting statistics (Spearman r = 0.88) showed high accuracy. The map generated can facilitate both the study of broad scale processes linking predators and prey as well as roe deer management in southeastern Norway. [less ▲]

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See detailMagnetic shielding performances of YBa2Cu3O7−δ -coated silver tubes obtained by electrophoretic deposition
Devendra Kumar, N; Closset, Raphaël ULg; Wera, Laurent ULg et al

in Superconductor Science and Technology (2015), 28

We report a complete procedure to achieve multilayer YBCO thick films by electrophoretic deposition on silver tubes using a suspension of YBCO powder in butanol. With the aim to optimize the magnetic ... [more ▼]

We report a complete procedure to achieve multilayer YBCO thick films by electrophoretic deposition on silver tubes using a suspension of YBCO powder in butanol. With the aim to optimize the magnetic shielding performances of the coatings, we have carried out an extensive investigation of the influence of the deposition parameters, the multilayer deposition sequence and the intermediate/final heat treatments on the coating microstructure. Using the optimized conditions, a 24-layer YBCO coating has been successfully prepared on an 80 mm long Ag tube: the melt growth processed multilayered YBCO thick film thus obtained can shield an applied magnetic field of 1.9 mT at 77 K, the highest value per thickness unit reported so far in the literature for these materials. [less ▲]

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See detailPrevalence and prognosis of Alzheimer’s disease at the mild cognitive impairment stage
Vos; VERHEY, F.; Frölich, L. et al

in Brain : A Journal of Neurology (2015)

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See detailLectures de La Reine Albemarle ou le dernier touriste. Ontologie, autobiographie, politique
Cormann, Grégory ULg

in Bulletin d'Analyse Phénoménologique (2015), 11(1),

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See detail"Passer la ligne" : La rencontre de Fanon et de Sartre
Cormann, Grégory ULg

in Luneau, Marie-Pier; Saint-Amand, Denis (Eds.) La Préface. Formes, enjeux et effets d’un discours d’escorte (2015)

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See detailSartre in Venedig: der Mann, der in die Kälte ging
Cormann, Grégory ULg; Viehöver, Vera ULg

in Bulletin d'Analyse Phénoménologique (2015), 11

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