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See detailLinear formulation of identifying cdes in graphs
Vandomme, Elise ULg; Gravier, Sylvain; Parreau, Aline ULg

Poster (2013, September 09)

Identifying codes were introduced by Karpovsky, Chakrabarty and Levitin in 1998 and can be applied to locate fire in a building using sensors. Buildings are modelled by graphs with rooms as vertices. The ... [more ▼]

Identifying codes were introduced by Karpovsky, Chakrabarty and Levitin in 1998 and can be applied to locate fire in a building using sensors. Buildings are modelled by graphs with rooms as vertices. The placement of sensors in the rooms corresponds to choosing a subset of vertices. Finding a sensor-placement such that the location of a fire in one room can be precisely determined is equivalent to constructing an identifying code in the graph. These are dominating sets of vertices for which the closed neighbourhood of each vertex (i.e., the vertex and its neighbours) has a unique intersection with the set. The problem of finding an identifying code has been widely studied. Yet its formulation as an integer linear problem hasn't been much considered. Let G be a graph with vertex set V, to an identifying code $C\subseteq V$ of $G$ correspond weights x_u (x_u is 1 if u belongs to C, otherwise x_u is 0) satisfying the following : for all vertices u,v * the sum of the x_w for w in the closed neighbourhood of u is at least 1 * the sum of the x_w for w in the symmetric difference of the closed neighbourhoods of u and v is at least 1. Of course, it is interesting to find an identifying code with the smallest possible cardinality. But in general this is a NP-hard problem. A way to obtain bounds on the minimal cardinality is to consider the associated linear problem where the weights x_u are fractional. In the case of vertex-transitive graphs, the minimal cardinality for the fractional case can only take two values which depend on the number of vertices, the degree of the graph and the smallest symmetric difference between any two closed neighbourhoods. We show that for an infinite family of graphs the bound is tight and for another another the bound is far too be reached. [less ▲]

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See detailLinear magnetoelectric effect by orbital magnetism
Scaramucci, A.; Bousquet, Eric ULg; Fechner, M. et al

in Physical Review Letters (2012), 109(19),

We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an ... [more ▼]

We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO 4 as a model compound we show that spin-orbit coupling partially lifts the quenching of the 3d orbitals and causes small orbital magnetic moments (μ (L)≈0.3μ B) parallel to the spins of the Fe2 + ions. An applied electric field E modifies the size of these orbital magnetic moments inducing a net magnetization linear in E. © 2012 American Physical Society. [less ▲]

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See detailLinear regression under fixed-rank constraints: a Riemannian approach
Meyer, Gilles ULg; Bonnabel, Silvère; Sepulchre, Rodolphe ULg

in Proceedings of the 28th International Conference on Machine Learning (2011)

In this paper, we tackle the problem of learning a linear regression model whose parameter is a fixed-rank matrix. We study the Riemannian manifold geometry of the set of fixed-rank matrices and develop ... [more ▼]

In this paper, we tackle the problem of learning a linear regression model whose parameter is a fixed-rank matrix. We study the Riemannian manifold geometry of the set of fixed-rank matrices and develop efficient line-search algorithms. The proposed algorithms have many applications, scale to high-dimensional problems, enjoy local convergence properties and confer a geometric basis to recent contributions on learning fixed-rank matrices. Numerical experiments on benchmarks suggest that the proposed algorithms compete with the state-of-the-art, and that manifold optimization offers a versatile framework for the design of rank-constrained machine learning algorithms. [less ▲]

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See detailLinear Repeating Points [chap. 13]
Wolper, Pierre ULg

in Kuper, Gabi; Libkin, Leonid; Paredaens, Jan (Eds.) Constraint Databases (2000)

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See detailLinear stability analysis of an evaporating binary liquid layer with fully transient reference profiles
Machrafi, Hatim ULg; Rednikov, Alexey; Colinet, Pierre et al

in Bulletin of the American Physical Society, Vol. 55, n°16 (2010)

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See detailA linear-quadratic model of cell survival considering both sublethal and potentially lethal radiation damage
Rutz, HP; COUCKE, Philippe ULg; Mirimanoff, RO

in Radiotherapy & Oncology (1991), 21(4), 273-276

We assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was ... [more ▼]

We assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was enhanced increased exponentially with a linear and a quadratic component, namely xi and psi: RR = e xi D + psi D2. Survival of irradiated cells can thus be expressed by a combined linear-quadratic model considering four variable, namely alpha and beta for the capacity of the cells to accumulate sublethal damage, and xi and psi for their capacity to repair potentially lethal damage: SF = e(xi - alpha)D + (psi - beta)D2. [less ▲]

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See detailLa linéarité comme métadiscours dans l’oeuvre de Murray Bail
Herbillon, Marie ULg

in MethIS : Méthodes et Interdisciplinarité en Sciences Humaines (2008), 1

Si d’aucuns ont relevé, chez Murray Bail, une propension à la géométrisation des espaces textuels, nul n’a souligné la fonction politico-parodique de la ligne droite dans l’oeuvre de cet écrivain ... [more ▼]

Si d’aucuns ont relevé, chez Murray Bail, une propension à la géométrisation des espaces textuels, nul n’a souligné la fonction politico-parodique de la ligne droite dans l’oeuvre de cet écrivain australien contemporain. En feignant de souscrire à la culture de la linéarité, ce dernier vise pourtant à la dénoncer et, avec elle, un certain héritage occidental. Cette réflexion prend, à l’occasion, un tour métafictionnel : bien que ses intentions parodiques aient pu le contraindre à emprunter au réalisme traditionnel certains de ses codes narratifs, Bail a longtemps cherché à discréditer ce genre littéraire trop linéaire. Avec Eucalyptus (1998), l’auteur parvient toutefois à transcender la linéarité structurelle apparente de ses premiers romans. Cet article explore les manières dont Bail s’est approprié le réalisme et/ou l’a transgressé pour, en définitive, mieux l’intégrer à la littérature australienne. [less ▲]

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See detailLinearity and stationarity of the pharmacokinetics of tiludronate in horses
Delguste, Catherine ULg; Doucet, Michèle; Amory, Hélène ULg et al

Poster (2005)

Two studies were conducted in order to assess the linearity and stationarity of the pharmacokinetics of tiludronate in horses. For each study, plasma concentrations of tiludronate were measured by HPLC-UV ... [more ▼]

Two studies were conducted in order to assess the linearity and stationarity of the pharmacokinetics of tiludronate in horses. For each study, plasma concentrations of tiludronate were measured by HPLC-UV at regular intervals and noncompartmental analysis was performed. First, single intravenous administrations of 0.05 (group 1, n = 5), 0.1 (group 2, n = 5) and 0.2 mg/kg (group 3, n = 5) were performed in healthy male adult horses. A linear relationship between groups was found for C5min (C5min = 0.0726 + 11.8589 * dose) as well as for AUC0-inf (AUC0-inf = -0.632561 + 30.9649 * dose). Clearance ranged from 0.033 to 0.044 L/h/kg and was not significantly different between groups. MRT (h) were 3.96, 4.95 and 9.40 and VDss (L/kg) were 0.16, 0.19 and 0.28 for the 0.05, 0.1 and 0.2 mg/kg doses respectively. Second, 10 daily intravenous administrations at a dosage rate of 0.1 mg/kg were administered to 4 healthy horses. Plasma tiludronate concentrations were measured after the 1st and 10th dose as well as 8 hours after each dose. The mean plasma accumulation ratio between the 1st and the 10th dose was 1.31 ± 0.48. Medians of the tiludronate concentration values measured in plasma 8 hours post-dose were not statistically different between doses. Maximum and minimum concentrations of tiludronate (mg/L) following the last dose were 0.91 and 0.04 respectively. It was concluded that the pharmacokinetics of tiludronate in horses are linear from 0.05 to 0.2 mg/kg IV and stationary after 10 IV administrations of 0.1 mg/kg. [less ▲]

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See detailLinearity as Metadiscourse in Murray Bail’s Fiction
Herbillon, Marie ULg; Pons, Xavier; Birgy, Philippe

in Anglophonia / Caliban. French Journal of English Studies: Divergences and Convergences (2007), 21

Il est possible de considérer que la complexité inhérente à l’œuvre du romancier australien Murray Bail découle principalement de son inhabituel degré de sophistication abstraite. Même si certains ... [more ▼]

Il est possible de considérer que la complexité inhérente à l’œuvre du romancier australien Murray Bail découle principalement de son inhabituel degré de sophistication abstraite. Même si certains commentateurs ont rapidement détecté la géométrisation systématique de ses espaces narratifs, dans lesquels s’entrecroisent des myriades de lignes droites, peu en ont souligné la dimension politico-parodique : en feignant de souscrire à la culture de la linéarité, Bail vise manifestement à la dénoncer et, avec elle, un certain héritage occidental. Cette réflexion sur le concept de linéarité peut également prendre un tour métafictionnel : bien que ses intentions parodiques le contraignent parfois à emprunter au réalisme certains de ses codes narratifs, l’auteur désavoue indubitablement ce genre littéraire par trop linéaire, qu’il voit comme « la grande malédiction de la littérature australienne ». Toutefois, au-delà d’une linéarité structurelle apparente, Bail ne renonce pas à une utopie de langage : dans Eucalyptus (1998), il avance ainsi de possibles alternatives au(x) genre(s) qu’il discrédite. Cet article explore les manières dont la linéarité peut être intégrée dans le bagage culturel et épistémologique de l’Australie plutôt que d’en être exclue, dans le but de définir l’outil linguistique original que Bail s’efforce de créer. [less ▲]

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See detailLinearized Power Flow Equations Based Predictive Control of Transmission Voltages
Hajian, Mahdi; Rosehart, William; Glavic, Mevludin et al

in Proceedings of the 46th Hawaii International Conference on System Sciences (HICSS-46) (2013, January)

In this paper, an approach based on the concept of Model Predictive Control (MPC) is used to control transmission voltages and prevent long-term voltage instability. The MPC model is based on a linearized ... [more ▼]

In this paper, an approach based on the concept of Model Predictive Control (MPC) is used to control transmission voltages and prevent long-term voltage instability. The MPC model is based on a linearized steady-state system model derived from power flow equations. Simulation results are presented for the case of Nordic32 test system. [less ▲]

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See detailLinearizing Option Returns for Portfolio and Risk Management
Bodson, Laurent ULg; Hübner, Georges ULg

Conference (2007, October 18)

This paper proposes a method to deduce the first four moments and the co-moments (with any other asset) of an option return. We consider the dynamics of an option-replicating portfolio of four basic ... [more ▼]

This paper proposes a method to deduce the first four moments and the co-moments (with any other asset) of an option return. We consider the dynamics of an option-replicating portfolio of four basic assets: the underlying, two long-term options and a zero coupon bond. This approach allows us to capture the moments up to order four of the underlying and to linearize the option return. A numerical example illustrates some of the features and applications of this model. [less ▲]

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See detailLinearizing Option Returns for Portfolio and Risk Management: A Tetranomial Approach
Bodson, Laurent ULg; Hübner, Georges ULg

Conference (2006, November 21)

This paper proposes a method to deduce the first four moments and the co-moments (with any other asset) of an option return. We consider the dynamics of an option-replicating portfolio of four basic ... [more ▼]

This paper proposes a method to deduce the first four moments and the co-moments (with any other asset) of an option return. We consider the dynamics of an option-replicating portfolio of four basic assets: the underlying, two long-term options and a zero coupon bond. This approach allows us to capture the moments up to order four of the underlying and to linearize the option return. A numerical example illustrates some of the features and applications of this model. [less ▲]

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See detailLinearly polarized second harmonic generation microscopy reveals chirality
Valev, V. K.; Silhanek, Alejandro ULg; Smisdom, N. et al

in Optics Express (2010), 18(8), 8286-8293

In optics, chirality is typically associated with circularly polarized light. Here we present a novel way to detect the handedness of chiral materials with linearly polarized light. We performed Second ... [more ▼]

In optics, chirality is typically associated with circularly polarized light. Here we present a novel way to detect the handedness of chiral materials with linearly polarized light. We performed Second Harmonic Generation (SHG) microscopy on G-shaped planar chiral nanostructures made of gold. The SHG response originates in distinctive hotspots, whose arrangement is dependent of the handedness. These results uncover new directions for studying chirality in artificial materials. (C) 2010 Optical Society of America [less ▲]

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See detailLinearly polarized second harmonic generation microscopy reveals chirality (vol 18, pg 8286, 2010)
Valev, V. K.; Silhanek, Alejandro ULg; Smisdom, N. et al

in Optics Express (2011), 19(10), 9242-9244

An erratum is presented to clarify both the direction of light polarization in our experiments and the unit cell geometry of the samples. Additionally, the spectral dependence of the second harmonic ... [more ▼]

An erratum is presented to clarify both the direction of light polarization in our experiments and the unit cell geometry of the samples. Additionally, the spectral dependence of the second harmonic generation response in the G-shaped nanostructures made of gold is corrected. These changes do not affect our previous conclusions. (C) 2011 Optical Society of America [less ▲]

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See detailLinelist: an interactive program for analysing beam-foil spectra
Bastin, Thierry ULg; Garnir, Henri-Pierre ULg

in Proceedings of the 4th International Conference "Physics Computing '92" (1993)

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See detailLines of force and points of contact in the dramaturgy of francophone Belgium
Delhalle, Nancy ULg

in Herbet Ian; Leclercq Nicole (Eds.) The world of theatre (2000)

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See detailLineweaver-Burk, Hanes, Eadie-Hofstee and Dixon Plots in Non-steady-state Situations.
Frère, Jean-Marie ULg; Leyh, Bernard ULg; Renard, André

in Journal of Theoretical Biology (1983), 101

Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon plots can only be used when a true initial rate is measured. Despite the fact that this point has often been stressed, it is far too often ignored in favour ... [more ▼]

Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon plots can only be used when a true initial rate is measured. Despite the fact that this point has often been stressed, it is far too often ignored in favour of restricting the essay time to one where low amounts of substrate are used. When one or several irreversible and slow steps occur with an inactivator during the incubation of a ternary enzyme-substrate-inactivator mixture, the rate of the enzyme-catalyzed reaction progressively decreases. Even under these conditions, the present computer simulations investigations show that apparently linear Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon graphs can be obtained when the amount of product is mistakenly assumed to represent the true initial rate. Moreover, the observed pattern can change with time, going for instance from non-competitive to competitive. "Ki's" measured under these conditions also vary with time and bear little relationship to the true constants involved in the interaction. [less ▲]

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See detailLingopti project: semi-continuous casting process of coper-nickel alloys
Pecquet, Etienne ULg; Pascon, Frédéric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Dick, E.; Vierendeels, J.; Cantrijn, F. (Eds.) et al Proceedings of the 6th national congress on theoretical and applied mechanics (2003)

Lingopti project is a First Europe project. It treats semi-continuous casting of copper-nickel alloys ingots. The research, performed in the University of Liège, consists in the optimisation of the mould ... [more ▼]

Lingopti project is a First Europe project. It treats semi-continuous casting of copper-nickel alloys ingots. The research, performed in the University of Liège, consists in the optimisation of the mould and the whole casting process of the LBP S.A. company (Chênée – Liège) to obtain better cast products. In fact, cast products sometimes present long oscillation marks (λ ≈ 500mm) and some ingots have many internal cracks. The semi-continuous process consists in the vertical casting of 7m height ingots. The goal is also to test different chemical compositions of the material and to predict what happens on the casting process. [less ▲]

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See detailLingopti project: semi-continuous casting process of copper-nickel alloys
Pecquet, Etienne ULg; Volles, Ralf; Lecomte-Beckers, Jacqueline ULg et al

in Proceedings of the 21st International Congress of Theoritical and Applied Mechanics (2004)

The following text deals with casting of copper-nickel alloys. They are high added values materials. The research contains two main parts. Laboratory tests (completed with bibliography) that provide ... [more ▼]

The following text deals with casting of copper-nickel alloys. They are high added values materials. The research contains two main parts. Laboratory tests (completed with bibliography) that provide thermal and mechanical properties of the ingot and the mould but also heat transfer coefficients between the ingot and its environment (mould, air and water). These parameters are required in the second part : development and validation of numerical modelization by the finite element method to optimise the industrial process. [less ▲]

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