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See detailAlma @ ULg : Déploiement d'Alma à l'Université de Liège
Renaville, François ULg

Conference given outside the academic context (2015)

Présentation du projet de migration de Aleph et SFX vers le système de gestion de bibliothèque (SGB) Alma d'août 2014 à février 2015.

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See detailLes complications rénales du diabète
Krzesinski, Jean-Marie ULg

Conference (2015, June 24)

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See detailLearning Artificial Intelligence in Large-Scale Video Games: A First Case Study with Hearthstone: Heroes of Warcraft
Taralla, David ULg

Master's dissertation (2015)

Over the past twenty years, video games have become more and more complex thanks to the emergence of new computing technologies. The challenges players face now involve the simultaneous consideration of ... [more ▼]

Over the past twenty years, video games have become more and more complex thanks to the emergence of new computing technologies. The challenges players face now involve the simultaneous consideration of many game environment variables — they usually wander in rich 3D environments and have the choice to take numerous actions at any time, and taking an action has combinatorial consequences. However, the artificial intelligence (AI) featured in those games is often not complex enough to feel natural (human). Today's AI is still most of the time hard-coded, but as the game environments become increasingly complex, this task becomes exponentially difficult. To circumvent this issue and come with rich autonomous agents in large-scale video games, many research works already tried and succeeded in making video game AI learn instead of being taught. This thesis does its bit towards this goal. In this work, supervised learning classification based on extremely randomized trees is attempted as a solution to the problem of selecting an action amongst the set of available ones in a given state. In particular, we place ourselves in the context where no assumptions are made on the kind of actions available and where action simulations are not possible to find out what consequences these have on the game. This approach is tested on the collectible card game Hearthstone: HoW, for which an easily-extensible simulator was built. Encouraging results were obtained when facing Nora, the resulting Mage agent, against random and scripted (medium-level) Mage players. Furthermore, besides quantitative results, a qualitative experiment showed that the agent successfully learned to exhibit a board control behavior without having been explicitly taught to do so. [less ▲]

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See detailDistributive contact lattices with nontangential part-of relations
Raskin, Julien ULg

Conference (2015, June 23)

In a Boolean algebra, the "contact" and "nontangential part-of" relations are linked and interdefinable thanks to the complement. These relations yield on the Stone dual of the algebra two closed ... [more ▼]

In a Boolean algebra, the "contact" and "nontangential part-of" relations are linked and interdefinable thanks to the complement. These relations yield on the Stone dual of the algebra two closed relations that appear to be the same. In a distributive lattice, the contact and nontangential part-of relations also yield dual closed relations on the Priestley dual. However, as the link between them is lost, these relations are not equal anymore. We explore the conditions linking the contact and nontangential part-of relations one should add in order to recover these relations knowing the intersection of their dual. [less ▲]

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See detailAging mechanisms in amorphous phase-change materials
Raty, Jean-Yves ULg

Conference (2015, June 23)

Aging phenomena are common to all amorphous structures, but of special importance in phase change materials (PCM) since it impedes the realization of multi-level memories. Different interpretations have ... [more ▼]

Aging phenomena are common to all amorphous structures, but of special importance in phase change materials (PCM) since it impedes the realization of multi-level memories. Different interpretations have been proposed, but we focus here on the structural relaxation of amorphous GeTe, chosen because it is the simplest system that is representative of the wider class of GST alloys, lying along the GeTe-Sb2Te3 composition line of the GeSbTe phase diagram. The direct melt-and-quench DFT based Molecular Dynamics approach leads to models with a few hundred atoms, and, hence a small number of atomic environments. Here we sample a large number of local atomic environments, and bonding schemes, by chemically substituting different alloys to favor different local atomic structures. This enables spanning a larger fraction of the configuration space relevant to aging. GST alloys are known to display complex bonding that does not follow the chemist’s “octet-rule”. This lead to many controversies, especially concerning the local structure around Ge atoms. We overcome this problem by using state of the art non local DFT-MD, including the so-called van der Waals corrections. This leads to more clearly defined environments that are thoroughly analyzed. We can then identify their fingerprints in the available structural experimental data and assess their stability to find the driving forces leading to the structural relaxation. The calculated electronic properties nicely match the most recent photothermal deflection spectroscopy experiments. Our results support a model of the amorphous phase and its time evolution that involves an evolution of the local (chemical) order towards that of the crystal (by getting rid of homopolar bonds), and an evolution of its electronic properties that drift away from those of the crystal, driven by an increase of the Peierls-like distortion of the local environments in the amorphous [1]. [1] J.Y Raty, W. Zhang, J. Luckas, C. Chen, R. Mazzarello, C. Bichara and M. Wuttig, Nature Comm. To appear. [less ▲]

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See detailTransnational routes for hyper-local practices. Homemade food of Moroccan migrant women in Italy.
Mescoli, Elsa ULg

Conference (2015, June 22)

Stemming from a doctoral research on the culinary practices of a group of Moroccan migrant women living in the north of Italy, this paper will focus on some narratives and habits concerning homemade food ... [more ▼]

Stemming from a doctoral research on the culinary practices of a group of Moroccan migrant women living in the north of Italy, this paper will focus on some narratives and habits concerning homemade food. This food was the result of the combination of hyper-local and transnational practices. In fact, preparing some food at home instead of buying it (bread, for example) was possible also thanks to the use of some ingredients that were bought in or coming from Morocco. The issue at stake was that of control: a control exerted at a hyper-local level (in one’s home) on procedures and at a transnational level (by personally knowing ingredients’ producers) on food elements. This combination let women prepare some representative food of their memory by using the traditional techniques learnt from their mothers and by excluding intermediations. Homemade food translated the reassuring utopia of keeping a link with a cultural belonging in spite of migration and of reducing the fear of being contaminated by the unknown products of the diversity. Some ethnographic data will be presented to show these dynamics, and they will be supported by the visual material collected through participant observation. [less ▲]

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See detailChanger son système d'information, penser l'organisation plus que la technique : illustration avec le passage à Alma à l’Université de Liège
Renaville, François ULg

Scientific conference (2015, June 22)

Présentation du projet de migration de Aleph et SFX vers le système de gestion de bibliothèque (SGB) Alma d'août 2014 à février 2015.

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See detailTowards an “integrated conservation” : the contribution of R.M. Lemaire and Piero Gazzola during the first decade of ICOMOS (1965-1975)
Houbart, Claudine ULg

Conference (2015, June 22)

Respectively elected first President and first Secretary General during the first general assembly of ICOMOS in Cracow in 1965, Piero Gazzola and Raymond M. Lemaire have deeply contributed to the success ... [more ▼]

Respectively elected first President and first Secretary General during the first general assembly of ICOMOS in Cracow in 1965, Piero Gazzola and Raymond M. Lemaire have deeply contributed to the success of the newly born organisation. During the first years, they didn’t only provoke the creation of numerous national committees around the world, but they also positioned ICOMOS as a major actor of the international conservation scene, through the organisation of conferences and an active participation in the debates initiated by Unesco and the Council of Europe, for which ICOMOS acted as a consultant. The study of Raymond M. Lemaire’s archive, kept at the KU Leuven in Belgium, clearly shows that one of the major concerns of both Lemaire and Gazzola, who had been, in 1964, amongst the main authors of the Venice Charter, was to broaden the scope of the document in order to address the issue of pre-industrial city centres, threatened by late reconstruction or development projects mostly promoting functionalist approaches. Depending on the time available, this presentation will address one or various aspects of Lemaire’s and Gazzola’s contribution to the emergence of integrated conservation, consecrated by the European Charter and the Amsterdam Declaration of 1975, that is: the new ideas (social value of heritage for example) developed during the expert meetings organised by the Council of Europe in 1965-1968, where they both represented ICOMOS. These ideas are synthesised in the report “Saving the face of Europe” in 1973, the relation between these theoretical contributions and Lemaire and Gazzola’s contemporary field experience, the role of Eastern Europe experiences (D. Libal in Prague and M. Horler in Budapest) in the development of an appropriate methodology to address urban issues, the differences between the concept of “integral planning” proposed by Lemaire in 1973 and the “integrated conservation” that was promoted by the 1975 Council of Europe charters, an epilogue could mention the revision projects of the Venice Charter between 1975 and 1981. Based on my PhD about R.M. Lemaire, recently presented at the KU Leuven (Belgium), this presentation aims at clarifying and illustrating the shift from monument restoration towards city “reanimation” or “rehabilitation” during the late sixties and seventies, as well as paying tribute to the action of two of the most important figures of the beginnings of ICOMOS. [less ▲]

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See detailFrom the spirit to the letter of the charters : mind the gap for the future
Houbart, Claudine ULg; Dawans, Stéphane ULg

Conference (2015, June 22)

Since the 1960’s and the foundation of ICOMOS, charters have been considered as a sort of conservation gospel. In this presentation, we would like to question this fact, in the light of the very ... [more ▼]

Since the 1960’s and the foundation of ICOMOS, charters have been considered as a sort of conservation gospel. In this presentation, we would like to question this fact, in the light of the very particular production and reception conditions of the documents. What may be perceived as a mostly provocative approach seems to us a constructive basis for future reflections. When we read and use charters – in this presentation, we will mainly focus on the Venice Charter, the Nara document and the Riga Charter – , we forget too often that they have been written by human beings, sometimes very tired, in a hurry, and even arguing with each other. The study of the archival material related to the writing of the Venice Charter and the Nara document very clearly illustrates that these documents are rather a conceptual “bricolage” than indisputable normative texts as if they had been written by lawyers. In the case of the Venice Charter, the archive as well as the records of Raymond M. Lemaire, Paul Philippot or Gertrud Tripp make clear that the document has been written at the last moment and adopted too rapidly by an assembly too glad to finally have a updated version of the Athens charter. As a consequence, only a few years later, Raymond Lemaire and Piero Gazzola already questioned the validity of the new text in the light of the extension of heritage debates to the city centers. On the other hand, the fact that a French and an English version of the Nara document were written in parallel by Raymond M. Lemaire and Herb Stovel in 1994 has had immediate consequences on the content and the formulation of the text, which logically left both of them unsatisfied with the result. Even so, the Venice charter and the Nara document still have force of law today. Yet, besides the particular circumstances of their writing, we must keep in mind that these texts answered specific questions, closely linked to the context: a critical answer to postwar reconstruction for the first, and apparently opposed visions of authenticity between East and West for the second. As far as the Riga charter is concerned, the influence of the delicate context of the Eastern bloc collapse is evident. For this reason, using such documents today requires at least a critical reading, going back to the spirit beyond the text. Our presentation will illustrate ad absurdum, through recent case studies, how a cynical reading of such documents can lead to interventions dangerously in conflict with this spirit and the fundamental ideals of conservation philosophy. In the era of late capitalism and heritage globalization, are we allowed to forget the conditions and the context in which our doctrinal documents have been written to justify anything and everything and to meet, for example, the “tourist gaze”, the “nouveaux riches” taste or the architect’s egomania? Do architects really want to know what the writers of the Venice charter’s article 9 meant by the “contemporary stamp”? What are the limits of the tolerance towards reconstruction first expressed by the Nara document, and a few years later, the charter of Riga? So many questions that ICOMOS must face if it wants to pursue its guiding mission in a mostly financial world. [less ▲]

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See detailEngager le littéraire : le cas Sartre/Fanon
Cormann, Grégory ULg

Conference (2015, June 20)

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See detailUrban Development as a Continuum: A Multinomial Logistic Regression Approach
El Saeid Mustafa, Ahmed Mohamed ULg; Cools, Mario ULg; Saadi, Ismaïl ULg et al

in Gervasi, Osvaldo; Murgante, Beniamino; Misra, Sanjay (Eds.) et al Computational Science and Its Applications – ICCSA 2015, Part III (2015)

Urban development is a complex process influenced by a number of driving forces, including spatial planning, topography and urban economics. Identifying these drivers is crucial for the regulation of ... [more ▼]

Urban development is a complex process influenced by a number of driving forces, including spatial planning, topography and urban economics. Identifying these drivers is crucial for the regulation of urban development and the calibration of predictive models. Existing land-use models generally consider urban development as a binary process, through the identification of built versus non-built areas. This study considers urban development as a continuum, characterized by different level of densities, which can be related to different driving forces. A multinomial logistic regression model was employed to investigate the effects of drivers on different urban densities during the past decade in Wallonia, Belgium. Sixteen drivers were selected from sets of driving forces including accessibility, geophysical features, policies and socioeconomic factors. It appears that urban development in Wallonia is remarkably influenced by land-use policies and accessibility. Most importantly, our results highlight that the impact of different drivers varies along with urban density. [less ▲]

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See detailDevelopment of a new design method for the cross-section capacity of steel hollow sections
Nseir, Joanna ULg

Doctoral thesis (2015)

The cross-sectional behaviour of steel sections can be shown to be influenced by two extreme behaviors: the resistance and the instability. These boundaries are accounted for in current standards through ... [more ▼]

The cross-sectional behaviour of steel sections can be shown to be influenced by two extreme behaviors: the resistance and the instability. These boundaries are accounted for in current standards through a classification system consisting on rules depending on the cross-section dimensions. For example, in EN 1993-1-1, classes are defined spanning from stocky sections (class 1) able to develop their full plastic capacity, to slender sections (class 4) for which the effective properties are used with the use of the effective width method (EWM). However, for cold-formed steel sections, characterized by a non-linear material law, the cross-section resistance can go beyond its plastic capacity due to strain hardening effects. Moreover, with the emergence of high strength steel (i.e. cross-sections falling into class 4) and more complex cross-section shapes, the effective width method is becoming too complicated. Many other reasons and discrepancies are making the cross-section classification too complex and inconsistent. The Overall Interaction Concept (OIC) stands as a new design approach that aims at a straightforward design check of the stability and resistance of steel cross-sections. Based on the use of a generalized relative slenderness and so-called interaction curves, it can be applied to any type of cross-section, further includes potential non-linear material behaviour and covers combined loading cases. The main aim of this thesis is to develop and propose OIC interaction curves dedicated to steel hollow sections subjected to various load cases. A test program was carried out as a part of a European project named ‘HOLLOPOC’ to investigate the cross-sectional behavior of cold-formed hot-finished and hot-rolled square, rectangular and circular sections. 57 cross-sections tests including simple and combined load cases were performed. Besides, a finite element model was developed and calibrated on the basis of the tests, and its accuracy was seen to be sufficient to subsequently undergo an extensive numerical parametric study for hot-rolled and cold-formed cross-sections, leading to over than 40 000 numerical results. Based on these computations, design proposals were made within the context of the Overall Interaction Concept, using an extension of the Ayrton-Perry approach. Finally, a validation of the proposed formulae was made through a comparison with existing approach and worked examples were presented, in order to illustrate (i) the application of the method and (ii) its benefits in comparison to application of current EC3 rules. [less ▲]

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See detailScreening for Osteonecrosis in children treated for ALL : Why bother?
Geurten, Claire ULg; Hoyoux, Claire

Conference (2015, June 19)

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See detailResiliency of a Community of Buildings to Fire Following Earthquake
Gernay, Thomas ULg; Elhami Khorasani, Negar; Garlock, Maria

Conference (2015, June 19)

Cascading multi-hazard events, such as fires following an earthquake, can trigger progressive collapse of structures. In cascading earthquake and fire events, buildings that may have already experienced ... [more ▼]

Cascading multi-hazard events, such as fires following an earthquake, can trigger progressive collapse of structures. In cascading earthquake and fire events, buildings that may have already experienced damage due to a primary earthquake hazard, should cope with a secondary extreme event. This work provides a methodology to evaluate the risk of fire ignitions after an earthquake and building responses in a community. The work has two components: In the first part, a model is developed for predicting the probability of ignition in a building due to an earthquake. This probabilistic model relies on the data from seven significant earthquakes that took place in the U.S. between 1983 and 2014. The main parameters influencing the probability of ignition are found to be the peak ground acceleration, the type of building material, and the main features of the environment in which the buildings are located (i.e. the total square footage and the population density). In the second part of this work, fragility curves are developed for performance of structures under fire, to quantify the probability of exceeding a damage state given a fire scenario. The probabilistic ignition model is implemented in Ergo/Maeviz, a GIS based risk assessment software platform developed at the Mid-America Earthquake Center at UIUC. Ergo/Maeviz provides the probability of ignition after an earthquake for each building in a region of study, and the overall risk for the community. The developed package in Ergo/Maeviz is validated against number of historical fire following earthquake events. For the future work, the developed fragility curves for buildings under fire will be implemented in Ergo/Maeviz to integrate the probability of ignition and possible damage states of the buildings. This research integrates multi-hazard analysis and risk management to plan mitigation and recovery strategies, and to obtain resilient communities. [less ▲]

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See detailModel polyQ proteins based on the beta-lactamase BlaP: How non-polyQ regions influence the polyQ length-dependent aggregation process
Huynen, Céline ULg

Doctoral thesis (2015)

Neurodegenerative amyloid diseases are fatal disorders representing an important human health and economic burden. Amongst them, nine disorders are classified as polyglutamine (polyQ) diseases, for which ... [more ▼]

Neurodegenerative amyloid diseases are fatal disorders representing an important human health and economic burden. Amongst them, nine disorders are classified as polyglutamine (polyQ) diseases, for which no treatment is yet available. They are all characterized by the pathological expansion of a poly(CAG) sequence, above a specific threshold, within the coding sequence of nine unrelated genes, translated in nine polyQ proteins. The polyQ expansion, the only common point, is the critical determinant for polyQ disease development by triggering protein aggregation into amyloid fibrils. More recent studies however indicate that the protein context modulates the polyQ-induced aggregation process and the disease phenotype. The objectives of my thesis are to deeper investigate the molecular determinants of the complex interplay between the propensity of the polyQ tract to trigger protein aggregation and the modulating role of non-polyQ regions in order to allow the identification of strategies to interfere with the pathological aggregation process. For that purpose, model polyQ proteins, referred to as BlaP-polyQ chimeras, based on the β-lactamase BlaP and polyQ sequences (23 – 79Q) inserted at two positions (197, in between or not unstructured peptides, or 216), are used and their aggregation properties are characterized under several conditions. We first observe that the polyQ length is determinant for BlaP-polyQ chimera aggregation. Indeed, there is a Q-threshold for the aggregation into amyloid fibrils and for fibril elongation. Above this threshold, the aggregation in solution and the elongation rate increase with the length of the polyQ tract, with an exponential rise-to-maximum and a linear regression, respectively, independently of the conformation of the BlaP moiety, and of the position of the polyQ tract within BlaP. Longer polyQ tracts are likely to have a larger conformational flexibility allowing them to more easily adopt an amyloid-aggregation prone conformation. However, the Q-threshold for fibril elongation is much lower than for fibril formation in solution: the polyQ tract requires a larger conformational flexibility to nucleate the formation of fibrils than to elongate them. Secondly, the Q-threshold for fibril formation is lower once the BlaP moiety is unfolded, and BlaP-polyQ chimeras aggregate faster into amyloid fibrils under conditions favoring the unfolding of the BlaP moiety. The native structure of BlaP is likely to impose conformational constraints to moderate and long polyQ tracts that block and decrease, respectively, their propensity to form fibrils. The effects of constraints decrease with the polyQ length. Thirdly, BlaP chimeras with the polyQ tract in position 216 have an increased propensity to trigger the nucleation and the elongation of amyloid fibrils compared to chimeras with the polyQ in position 197. Advanced studies confirm that the propensity of the polyQ tract to aggregate into amyloid fibrils is linked to the conformational flexibility of the polyQ tract, which depends on (i) the polyQ length, (ii) the location of the polyQ tract within BlaP, i.e., a terminal location or embedded within a protein domain, and (iii) the structural properties of the polyQ flanking regions. Finally, we observe that the whole region flanking the polyQ tract in position 197 at its N-terminus has an anti-aggregating property that fully counterbalances the pro-aggregating property of that flanking at the C-terminus. The former imposes strong conformational constraints to the polyQ tract that reduce its conformational flexibility and hence its aggregation propensity. Moreover, these regions are likely to differently affect the solubility of the polyQ protein and hence the driving force for insoluble aggregation. Altogether, our data also suggest that BlaP chimeras aggregate via the commonly described nucleation-dependent polymerization mechanism during which the aggregation is first triggered by polyQ-polyQ interactions, and then a subsequent slight reorganization of the BlaP moiety is required for conversion of aggregates into amyloid fibrils. Based on these results, we should allow the development of therapeutic strategies, targeting specifically the molecular features of the complex interplay between the polyQ and non-polyQ regions during the nucleation and/or elongation of the pathological aggregation of polyQ proteins. [less ▲]

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