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See detailRandom subspace with trees for feature selection under memory constraints
Sutera, Antonio ULg; Châtel, Célia; Louppe, Gilles et al

Conference (2016, September 12)

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See detailMicrostructural design using stress–based topology optimization
Collet, Maxime ULg; Bruggi, Matteo; Noël, Lise ULg et al

Conference (2016, September 12)

New additive manufacturing techniques break the limitations encountered for years when producing components descending from topology optimization. Classical design procedures focus on macro-structural ... [more ▼]

New additive manufacturing techniques break the limitations encountered for years when producing components descending from topology optimization. Classical design procedures focus on macro-structural optimization to sustain given loads but today innovative manufacturing processes allow considering structures exhibiting tailored microstructures, i.e. the well known microstructural design. The practical applications of structures including material design is mainly motivated by the greater performances that can be achieved compared to classical solutions. Microstructural design has been shown a great interest as attested by recent works. However, stress–based topology optimization has not yet been extensively exploited when addressing microstructural design using numerical homogenization though stress constraints is an important feature and have gained in interest in the field of topology optimization. This contribution investigates the problem of material design enforcing stress constraints within periodic microstructures by considering a representative volume element (RVE) subject to prescribed strain fields. The SIMP approach is adopted as material interpolation law while the optimization problems are solved using a sequential convex programming approach. In particular the well known method of moving asymptotes (MMA) is considered. Numerical homogenization is used to assess the effective elastic properties of the microstructures. The Von Mises stress criterion is used to impose the constraints on the stress level. This work discusses the formulation of a well-posed design problem as well as some numerical issues encountered. The developed solution procedure is first validated by comparison against analytical results, e.g. the single inclusion of Vigdergauz microstructure. [less ▲]

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See detailPAI Annual Meeting
Ouhib, Farid ULg; Aqil, Abdelhafid ULg; Dirani, Ali et al

Poster (2016, September 12)

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See detail‘There is nothing more practical than a good theory’: Conceptual tools for conservation practice
Verbeeck, Muriel ULg

in Saving the Now: Crossing Boundaries to Conserve Contemporary Works (2016, September 12)

Faced with the growing number of case studies in contemporary art, philosophy provides conservators with a series of conceptual tools that allow to theorize their practice. The notion of intentionality ... [more ▼]

Faced with the growing number of case studies in contemporary art, philosophy provides conservators with a series of conceptual tools that allow to theorize their practice. The notion of intentionality and attentionality borrowed from Genette enables a better understanding of the problems that Dirty Corner by Anish Kapoor (a work vandalized on many occasions) poses. I will show that the conservator deals with the issue of the identity of a contemporary work in a different way from the art historian, and that philosophy is a practical tool to understand the specificity of the former’s approach and intervention. [less ▲]

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See detailInfluence of grain boundaries on the COads monolayer oxidation and oxygen reduction reaction kinetics
Asset, Tristan ULg; Chattot, Raphaël; Nelayah, Jaysen et al

Conference (2016, September 12)

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See detailThe role of bacteria and the addition of pyrite during leaching of Co(III) from heterogenite
Zeka, Leon; Gaydardzhiev, Stoyan ULg; Frenay, Jean ULg et al

in Proceedings of the XXVIII International Mineral Processing Congress (IMPC 2016) (2016, September 11)

Reductive leaching of cobalt (III) from a heterogenite bearing ore has been performed. Pyrite was added to the system and simultaneously bioleached in order to provide ferrous iron as reducing agent ... [more ▼]

Reductive leaching of cobalt (III) from a heterogenite bearing ore has been performed. Pyrite was added to the system and simultaneously bioleached in order to provide ferrous iron as reducing agent. Within such arrangement the iron ions are continuously re-circulated inside a Fe3+/ Fe2+ loop. As a result Co(III) is solubilized in the presence of Fe2+ ions in concentrations well below the stoichiometric requirement. The ore has been initially subjected to acid pre-leaching in order to guarantee that the available Co (II) has been entirely removed. Two technological parameters have been studied to show influence on the degree of cobalt leaching: concentration of ferric iron in the inoculum and the presence of bacteria. The bacterial role could be mainly viewed in supplying ferric ions in the system which chemically react with the pyrite to generate ferrous ions used as Co(III) reducing agent. Co(III) dissolution has been less efficient when the concentration of total iron in the system was low, but also when microorganisms were absent. SEM observations on leached heterogenite have evidenced bacterial attack on the mineral; however the precise role of bacterial presence on cobalt (III) leaching is still to be elucidated. [less ▲]

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See detailGeometallurgical Modelling of Low-Grade Itabirite Iron Ores from the Iron Quadrangle, Brazil
Martino, Rémi ULg; Correa de Araujo, Armando; Gotelip Barbosa, Marcela et al

in Proceedings of the XXVIII International Mineral Processing Congress (IMPC 2016) (2016, September 11)

The Iron Quadrangle district is a world-class iron ore mining district in the region of Belo Horizonte, capital of Minas Gerais state, in Brazil. Many mining companies have been mining high-grade hematite ... [more ▼]

The Iron Quadrangle district is a world-class iron ore mining district in the region of Belo Horizonte, capital of Minas Gerais state, in Brazil. Many mining companies have been mining high-grade hematite ores for decades throughout the region. The mines reserves often include itabirite ores which are available in high volumes, but have lower iron grades than hematite ores and require elaborated mineral processing to meet the requirements of downstream steelmaking. Itabirite ores have acquired importance, with the depletion of high-grade hematite reserves due to their intensive mining. The objective of this paper is to propose a geometallurgical model for the processing of itabirite ores from an Iron Quadrangle deposit, which will allow predicting the behaviour of ores throughout the deposit, according to their local variations. An initial step consists in characterizing representative samples of the different ores to acquire mineralogical and textural data. Then, itabirite ores of known characteristics are processed with different techniques, in order to extract the trends and key parameters upon which the geometallurgical model is developed. At first, the model takes into account the particle size distribution and its shift during mining and screening, as well as the chemistry and mineralogy of the material. Then, using the previously identified key parameters such as iron recovery, the model predicts the composition of the processing products. Finally, this data is used to model the mineralogy and mass recovery of the products. The geometallurgical model is of great importance, as it is able to model the processing of any sampled ore throughout the deposit. The incorporation of the results in a mining block model will assist mine planning and opens new opportunities for an optimized mining schedule. [less ▲]

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See detailLes tiques: parasites et vecteurs de maladies
Lempereur, Laetitia ULg

Article for general public (2016)

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See detailLinkages and production and marketing of rice vermicelli in traditional craft villages of Bac Giang province
Le Thy Long, Vy; Nguyen Huu, Nhuan; Lebailly, Philippe ULg

Conference (2016, September 10)

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See detailA new toolbox for the identification of diagonal Volterra kernels allowing the emulation of nonlinear audio devices
Schmitz, Thomas ULg; Embrechts, Jean-Jacques ULg

in Schmitz, Thomas (Ed.) International Congress on Acoustics : ICA, Argentine 5-9 Septembre 2016 (2016, September 10)

Numerous audio systems are nonlinear. It is thus of great importance to study them and understand how they work. Volterra series model and its subclass (cascade Hammerstein-Wiener model) are usual ways to ... [more ▼]

Numerous audio systems are nonlinear. It is thus of great importance to study them and understand how they work. Volterra series model and its subclass (cascade Hammerstein-Wiener model) are usual ways to modelize nonlinear systems. However the identification methods of these models are still considered as an open topic. Therefore we have developed a new optimized identification tool ready for use and presented as a Matlab toolbox. This toolbox provides the parameters of the optimized sine sweep needed for the identification method, it is able to calculate the parameters of the Hammerstein model and to emulate the output signal of a nonlinear device for a given input signal. To evaluate the toolbox, we modelize a guitar distortion effect (the Tubescreamer) having a total harmonic distortion (THD) comprised in the range 10-23\%. We report a mean error of less than 0.7\% between the emulated signal and the signal coming from the distortion effect. [less ▲]

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See detailSelf-defining memories and future projections as a means to facilitate reflection on life values in depressed adults: A preliminary study
Wagener, Aurélie ULg; Brouette, Béatrice ULg; Blairy, Sylvie ULg

Poster (2016, September 10)

Introduction. In the Brief Behavioral Activation Treatment for Depression, depressed patients are lead to a reflection on their personal values per life domains (e.g., family relationships, employment ... [more ▼]

Introduction. In the Brief Behavioral Activation Treatment for Depression, depressed patients are lead to a reflection on their personal values per life domains (e.g., family relationships, employment). The aim of this reflection is to tailor behavioral assignments through valued activities. This reflection is usually difficult for depressed patients. The current study hypothesized that exercises on autobiographical memories might act as a means to facilitate the reflection on personal values. In this perspective, self-defining memories (SDMs) and self-defining future projections (SDFPs) appear to be particularly relevant. SDMs and SDFPs concern reflections on the past and on the potential future central goals, values and conflicts of one’s life. SDMs and SDFPs are vivid and well-rehearsed autobiographical memories related to a meaning-making (i.e., a learned lesson about oneself, others or the world). The emotional valence of SDMs and SDFPs can either be positive, neutral or negative. Further, SDMs and SDFPs can consist in either specific events or categorical ones. Due to the relevance of these memories for the self, it is to be expected that recalling SDMs and imagine SDFPs will help individuals to have a clearer view of their personal values which in turn might facilitate the selection of valued activities. Further, it is hypothesized that these exercises might decrease depression and disturbances of psychological processes (i.e., rumination, self-concept clarity, environmental satisfaction). Therefore, this study aims were two-fold. First, it aimed at assessing the feasibility for depressed patients to recall SDMs and to imagine SDFPs per life domains. Second, it aimed at assessing the impact of these exercises on depression and psychological processes. Method. Nineteen depressed patients and 17 paired healthy controls (25-60 years) were recruited (data collection is still ongoing). This study comprises four meetings. During the first and the last meetings, participants completed self-reported assessments of depression and psychological processes. During the third and fourth meetings, participants were asked either to recall SDMs or to imagine SDFPs per life domains. SDMs and SDFPs were rated on specificity, meaning-making and emotional. The impact of these exercises was assessed on depression and psychological processes. Results. Preliminary results indicate that depressed patients are as able as healthy controls to recall SDMs and imagine SDFPs per life domains. Depressed patients recall less SDMs and SDFPs with meaning-making than healthy controls. Depressed patients report less SDMs and less SDFPs related to employment and less SDMs related to hobbies than healthy controls. Preliminary results show a decrease of depression in depressed patients only. Discussion. Even though depressed patients are as able as the healthy controls to recall SDMs and to imagine SDFPs, preliminary results highlight significant differences between depressed patients and healthy controls on SDMs and SDFPs. Preliminary results indicate that SDMs and SDFPs positively impact depression in depressed patients. Experimental and clinical implications of these findings will be discussed during the conference. [less ▲]

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See detailBrain connectivity and sensory stimulation in disorders of consciousness
Heine, Lizette ULg

Doctoral thesis (2016)

This thesis explores brain connectivity and sensory stimulation in patients with disorders of consciousness (DOC). These are serious conditions where massive brain damage can lead to a dissociation ... [more ▼]

This thesis explores brain connectivity and sensory stimulation in patients with disorders of consciousness (DOC). These are serious conditions where massive brain damage can lead to a dissociation between arousal and awareness (e.g., UWS and MCS). Part I explores brain connectivity. We highlight that brain function and structure are intimately related to each other, and to consciousness. The decrease in brain function can be used to distinguish between the clinically indicated states of consciousness. Part II evaluates passive sensory stimulations. Preferred stimuli may have the power to momentarily enhance brain function, and behavioral responses. [less ▲]

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See detailComplexité : Sciences humaines et promotion de la santé. A quelles conditions ?
Absil, Gaëtan ULg

Scientific conference (2016, September 09)

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See detailImplications de la perspective en première personne en psychopathologie : le cas de la schizophrénie
Englebert, Jérôme ULg; Valentiny, Caroline

Conference (2016, September 09)

Les approches traditionnelles de la schizophrénie en psychiatrie se centrent essentiellement sur une perspective que l’on peut qualifier de perspective en « troisième personne ». Ces considérations ... [more ▼]

Les approches traditionnelles de la schizophrénie en psychiatrie se centrent essentiellement sur une perspective que l’on peut qualifier de perspective en « troisième personne ». Ces considérations tentent, de l’extérieur, de circonscrire les difficultés auxquelles sont confrontées les personnes affectées d’une psychopathologie. Dans le cas de la schizophrénie, les manuels insistent notamment sur les symptômes délirants et hallucinatoires – signes sur lesquels, de facto, le clinicien et le patient ne peuvent s’entendre et rencontrer une phénoménologie commune. Une autre voie d’approche, s’inscrivant dans la tradition phénoménologique, propose d’explorer les phénomènes à partir du discours et du vécu subjectif des patients – dans une perspective en « première personne ». À partir d’une recherche récemment menée, nous explorerons le vécu subjectif de six patients schizophrènes à l’aide de l’échelle EASE (Examination of Anomalous Self-Experience). Cette échelle pose des balises dans la co-construction d’une narrativité permettant l’investigation d’expériences liées aux troubles du soi. Ce choix méthodologique s’ancre dans une volonté de laisser la place à l’étonnement, de ne pas pré-penser, ou le moins possible, le recueil d’expériences. Les analyses des phénomènes décrits par les patients se nourrissent des travaux de la psychopathologie phénoménologique (Blankenburg, Minkowski, Tatossian, Stanghellini, Sass, …) et se veulent un aller-retour constant entre théorie et clinique. Dans ce contexte, nous approfondirons l’hypothèse proposée par Louis Sass selon laquelle la folie, du moins dans certaines de ses formes, pourrait dériver d’une intensification plutôt que d’un affaiblissement de la conscience. L’hyper-réflexivité schizophrénique – indiquant une focalisation explicite et réflexive sur des phénomènes a priori implicites et préréflexifs – sera particulièrement analysée à partir des descriptions recueillies. Après avoir développé, à partir des cas cliniques, cette hypothèse d’une « hyper-conscience » comme symptôme cardinal de l’expérience subjective de la schizophrénie, nous analyserons les implications du recours à la perspective en « première personne » sur la prise en charge, les modèles de soins et la manière de concevoir le rapport au monde de ces patients. [less ▲]

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