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See detailA class of valid inequalities for multilinear 0-1 optimization problems
Crama, Yves ULg; Rodriguez Heck, Elisabeth ULg

E-print/Working paper (2016)

This paper investigates the polytope associated with the classical standard linearization technique for the unconstrained optimization of multilinear polynomials in 0-1 variables. A new class of valid ... [more ▼]

This paper investigates the polytope associated with the classical standard linearization technique for the unconstrained optimization of multilinear polynomials in 0-1 variables. A new class of valid inequalities, called 2-links, is introduced to strengthen the LP relaxation of the standard linearization. The addition of the 2-links to the standard linearization inequalities provides a complete description of the convex hull of integer solutions for the case of functions consisting of at most two nonlinear monomials. For the general case, various computational experiments show that the 2- links improve both the standard linearization bound and the computational performance of exact branch & cut methods. The improvements are especially significant for a class of instances inspired from the image restoration problem in computer vision. The magnitude of this effect is rather surprising in that the 2-links are in relatively small number (quadratic in the number of terms of the objective function). [less ▲]

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See detailClass V β Tubulin during the development of the organ of Corti in rat
Renauld, Justine ULg; Thelen, Nicolas ULg; Johnen, Nicolas ULg et al

Poster (2013, September 13)

In eutherian mammals, the organ responsible for the transduction of sound waves into nerve impulses is called the organ of Corti. This structure located within the cochlea, a portion of the inner ear, is ... [more ▼]

In eutherian mammals, the organ responsible for the transduction of sound waves into nerve impulses is called the organ of Corti. This structure located within the cochlea, a portion of the inner ear, is composed by two types of cells: sensory hair cells and non-sensory supporting cells. All these cells are distributed according to a specific arrangement along the whole length of the cochlea. A feature of the organ of Corti’s supporting cell is the presence of an abundant cytoskeleton. This one is mainly composed of microtubules, structures make up by tubulin heterodimers. The heterodimers consist of one molecule of α tubulin and one molecule of β tubulin. β tubulin isotypes are highly conserved in evolution and differ by only a few amino acid residues, implying that the isotypes may have functional significance. Organ of Corti’s supporting cells are constituted by class V β-tubulin, a minor mammalian tubulin (Bhattacharya et al., 2008). Moreover, their microtubules are formed by 15 protofilaments instead of the canonical 13, a unique fact among vertebrates (Banerjee et al., 2008). Such a configuration of protofilaments has been observed in C. elegans’ neurons which are responsible for the mechanosensory sense of touch (Bounoutas et al., 2009). It was also shown that these 15 protofilaments microtubules were essential to the proper functioning of these mechanosensory neurons (Bounoutas et al., 2009). Here we present the spatiotemporal localization of class V β-tubulin during the development of the organ of Corti in rats from embryonic day 18 (E18) until P25 (25th postnatal day). For this purpose, we have used immunolabelings on cryosections of whole cochlea. Our preliminary results demonstrate that class V β-tubulin has a unique distribution in the cochlea, being restricted to supporting cells, especially in pillar cells. [less ▲]

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See detailA class-A beta-lactamase from Pseudomonas stutzeri that is highly active against monobactams and cefotaxime.
Franceschini, N.; Galleni, Moreno ULg; Frère, Jean-Marie ULg et al

in The Biochemical journal (1993), 292 ( Pt 3)

A beta-lactamase produced by Pseudomonas stutzeri was purified to protein homogeneity, and its physicochemical and catalytic properties were determined. Its profile was unusual since, in addition to ... [more ▼]

A beta-lactamase produced by Pseudomonas stutzeri was purified to protein homogeneity, and its physicochemical and catalytic properties were determined. Its profile was unusual since, in addition to penicillins, the enzyme hydrolysed second- and third-generation 'beta-lactamase-stable' cephalosporins and monobactams with similar efficiencies. On the basis of the characteristics of the interaction with beta-iodopenicillanic acid, the enzyme could be classified as a class-A beta-lactamase. However, when compared with most class-A beta-lactamases, it exhibited significantly lower kcat./Km values for the compounds usually considered to be the best substrates of these enzymes. [less ▲]

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See detailLa Classe créative et le développement territorial: analyse des nouvelles formes de développement de l’activité économique et de leurs liens au territoire
Aouni, Zineb ULg; Pirnay, Fabrice ULg

Report (2013)

Le rapport présente une étude quantitative de la répartition géographique de la classe créative dans les provinces de Belgique et analyse la coïncidence géographique des facteurs favorables à son ... [more ▼]

Le rapport présente une étude quantitative de la répartition géographique de la classe créative dans les provinces de Belgique et analyse la coïncidence géographique des facteurs favorables à son regroupement et ses effets bénéfiques dans la province. Une analyse qualitative permet de mettre en évidence les facteurs favorables au regroupement de la classe créative en région Wallonne à différentes phases de son projet innovation. [less ▲]

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See detailLa classe de langue comme observatoire et laboratoire d'un apprentissage expérientiel des langues étrangères à travers la pédagogie par projet
Simons, Germain ULg

in Etudes & Travaux (1999), (3), 67-84

G. Simons begins by pointing out the difficulties encountered by many language teachers in trying to provide students with real communication situations. According to the author, the methodological ... [more ▼]

G. Simons begins by pointing out the difficulties encountered by many language teachers in trying to provide students with real communication situations. According to the author, the methodological approach which consists in asking students to "imagine they are Mr Smith" hardly conceals its formal interest. Furthemore, it should be completed with an experiential approach aiming at an articulation of the active experimentation of the foreign language in the here and now as well as the analysis of the functioning of the language as a system. The preparation and exploitation of a pedagogical project for a linguistic stay provides the foreign language course with a concrete aim and a real linguistic material, which it often lacks. In analysing and comparing the linguistic data from students and native speakers in real and identical communication situations, the language teacher can test the interlanguage of his students. Moreover, this process of comparison enables the language teacher to make students "notice the gap" between their language production and that of native speakers. This "notice the gap" technique transforms the traditional language class into an observatory and laboratory of the foreign language and of the interlanguage. [less ▲]

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See detailClasse II. Les manuscrits
Brassinne, Joseph ULg

in Catalogue de l'Exposition de l'Art Ancien au Pays de Liège. (1905)

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See detailLe classement des bois feuillus sur pied
Jourez, Benoît ULg; de Wauters, Philippe; Bienfait, Orane

in Silva Belgica (2010), 117

Cet article a pour objectif de se familiariser avec les critères d’estimation de la qualité et du classement des bois feuillus. Cette technique relativement subjective répartit la ressource en différentes ... [more ▼]

Cet article a pour objectif de se familiariser avec les critères d’estimation de la qualité et du classement des bois feuillus. Cette technique relativement subjective répartit la ressource en différentes catégories correspondant à des qualités particulières. Avec l’expérience, il est possible d’évaluer la valeur d’un arbre assez rapidement sur base de critères simples. Néanmoins, cette valeur globale dépend du prix attribué à chaque qualité. Le prix est en effet lié à de nombreux paramètres tels que l’offre et la demande, les quantités proposées, les conditions d’exploitation, la confiance de l’acheteur, la connaissance des marchés potentiels, … [less ▲]

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See detailClassement par ordre d'importance des zoonoses alimentaires : méthodes et application à la situation belge
Cardoen, S.; Van Huffel, X.; Berkvens, D. et al

in Epidémiologie et Santé Animale (2009), 55

Detailed reference viewed: 76 (11 ULg)
See detailUn classement supervisé de l’utilisation du sol et son exploitation dans l’agglomération liégeoise à partir d’une scène SPOT
Nadasdi, Istvan; Baudot, Yves; Donnay, Jean-Paul ULg et al

in Télédétection satellitaire et espaces urbains (1987)

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See detailClasses (effets, composition, fonctionnement)
Lafontaine, Dominique ULg

in Van Zantem (Ed.) Dictionnaire de l'éducation (2008)

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See detailClasses, conscience de classe et "classe politique"
Counet, Maxime ULg

Master's dissertation (2014)

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See detailClassical analogy for the deflection of flux avalanches by a metallic layer
Silhanek, Alejandro ULg

Conference (2015, May 17)

Motivated by the experimental observation of the exclusion of magnetic flux avalanches in a superconducting sample partially covered by a conducting capping layer, we have investigated the simpli fied ... [more ▼]

Motivated by the experimental observation of the exclusion of magnetic flux avalanches in a superconducting sample partially covered by a conducting capping layer, we have investigated the simpli fied case of the interaction of a magnetic charge (monopole and dipole) with a semi-in finite conducting plane. We have found that early theoretical descriptions for the damping enhancement due to the metallic sheet needed a correction at large vortex velocities where a decrease of the damping coe fficient is expected. We also demonstrate that vortex trajectories are strongly modi fied when penetrating into the area covered by the metallic sheet and may even be fully diverted from that area thus providing a qualitative explanation for the bending of the trajectories of flux avalanches. Our fi ndings may be extended to study the damping of Larkin-Ovchinnikov vortex instabilities and phase-slip lines in current driven systems. [less ▲]

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See detailClassical analogy for the deflection of flux avalanches by a metallic layer
Brisbois, Jérémy ULg; Vanderheyden, Benoît ULg; Colauto, Fabiano et al

in New Journal of Physics (2014), 16(10), 103003

Sudden avalanches of magnetic flux bursting into a superconducting sample undergo deflections of their trajectories when encountering a conductive layer deposited on top of the superconductor. Remarkably ... [more ▼]

Sudden avalanches of magnetic flux bursting into a superconducting sample undergo deflections of their trajectories when encountering a conductive layer deposited on top of the superconductor. Remarkably, in some cases the flux is totally excluded from the area covered by the conductive layer. We present a simple classical model that accounts for this behaviour and considers a magnetic monopole approaching a semi-infinite conductive plane. This model suggests that magnetic braking is an important mechanism responsible for avalanche deflection. [less ▲]

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See detailClassical analogy for the deflection of flux avalanches by a metallic layer
Silhanek, Alejandro ULg

Conference (2014, August 31)

Sudden avalanches of magnetic flux bursting into a superconducting sample undergo deflections of their trajectories when encountering a conductive layer deposited on top of the superconductor. Remarkably ... [more ▼]

Sudden avalanches of magnetic flux bursting into a superconducting sample undergo deflections of their trajectories when encountering a conductive layer deposited on top of the superconductor. Remarkably, in some cases the flux is totally excluded from the area covered by the conductive layer. We present a simple classical model that accounts for this behaviour and considers a magnetic monopole approaching a semi-infinite conductive plane. This model suggests that magnetic braking is an important mechanism responsible for avalanche deflection. [less ▲]

Detailed reference viewed: 28 (3 ULg)
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See detailClassical and Bayesian inference in neuroimaging : Theory
Friston, Karl J; Penny, W.; Phillips, Christophe ULg et al

in Neuroimage (2002), 16(2), 465-483

This paper reviews hierarchical observation models, used in functional neuroimaging, in a Bayesian light. It emphasizes the common ground shared by classical and Bayesian methods to show that conventional ... [more ▼]

This paper reviews hierarchical observation models, used in functional neuroimaging, in a Bayesian light. It emphasizes the common ground shared by classical and Bayesian methods to show that conventional analyses of neuroimaging data can be usefully extended within an empirical Bayesian framework. In particular we formulate the procedures used in conventional data analysis in terms of hierarchical linear models and establish a connection between classical inference and parametric empirical Bayes (PEB) through covariance component estimation. This estimation is based on an expectation maximization or EM algorithm. The key point is that hierarchical models not only provide for appropriate inference at the highest level but that one can revisit lower levels suitably equipped to make Bayesian inferences. Bayesian inferences eschew many of the difficulties encountered with classical inference and characterize brain responses in a way that is more directly predicated on what one is interested in. The motivation for Bayesian approaches is reviewed and the theoretical background is presented in a way that relates to conventional methods, in particular restricted maximum likelihood (ReML). This paper is a technical and theoretical prelude to subsequent papers that deal with applications of the theory to a range of important issues in neuroimaging. These issues include; (i) Estimating nonsphericity or variance components in fMRI time-series that can arise from serial correlations within subject, or are induced by multisubject (i.e., hierarchical) studies. (ii) Spatiotemporal Bayesian models for imaging data, in which voxels-specific effects are constrained by responses in other voxels. (iii) Bayesian estimation of nonlinear models of hemodynamic responses and (iv) principled ways of mixing structural and functional priors in EEG source reconstruction. Although diverse, all these estimation problems are accommodated by the PEB framework described in this paper. [less ▲]

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