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See detailEquivalence of weighted likelihood and Jeffreys modal estimation of proficiency under polytomous item response models
Magis, David ULg

Conference (2013, July 23)

This talk focuses on two proficiency level estimators in item response theory (IRT) framework: the weighted likelihood estimator (WLE) and the Jeffreys modal estimator (JME), that is, the usual Bayes ... [more ▼]

This talk focuses on two proficiency level estimators in item response theory (IRT) framework: the weighted likelihood estimator (WLE) and the Jeffreys modal estimator (JME), that is, the usual Bayes modal estimator with Jeffreys’ non-informative prior. With dichotomously scored items, the WLE and the JME are completely equivalent under the two-parameter logistic model, while remarkable relationships were established under the three-parameter logistic model. The purpose of this talk is to extend such comparison to polytomously scored items. It is shown that both WLE and JME are also equivalent for two broad classes of polytomous IRT models, including, among others, the (modified) graded response model, the (generalized) partial credit model, the rating scale model and the nominal response model. Parallelisms with dichotomously scored items are drawn. An example from a real data set is used to illustrate this finding. [less ▲]

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See detailAn equivalence test for comparing DNA sequences
Van Steen, Kristel ULg; Raby, B.; Molenberghs, G. et al

in Pharmaceutical Statistics (2005), 4(3), 203-214

Detailed reference viewed: 12 (4 ULg)
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See detailAn equivalence test for comparing DNA sequences.
Thijs, H.; Van Steen, Kristel ULg; Molenberghs, G. et al

in American Journal of Human Genetics (2001), 69(4), 1576

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See detailEquivalent diffusion coefficient and equivalent diffusion accessible porosity of a stratified porous medium
Huysmans, Marijke; Dassargues, Alain ULg

in Transport in Porous Media (2007), 66(3), 421-438

Diffusion is an important transport process in low permeability media, which play an important role in contamination and remediation of natural environments. The calculation of equivalent diffusion ... [more ▼]

Diffusion is an important transport process in low permeability media, which play an important role in contamination and remediation of natural environments. The calculation of equivalent diffusion parameters has however not been extensively explored. In this paper, expressions of the equivalent diffusion coefficient and the equivalent diffusion accessible porosity normal to the layering in a layered porous medium are derived based on analytical solutions of the diffusion equation. The expressions show that the equivalent diffusion coefficient changes with time. It is equal to the power average with p = -0.5 for small times and converges to the harmonic average for large times. The equivalent diffusion accessible porosity is the harmonic average of the porosities of the individual layers for all times. The expressions are verified numerically for several test cases. [less ▲]

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See detailEquivalent mixed model for joint genetic evaluation considering molecular and phenotypic information
Gengler, Nicolas ULg; Colinet, Frédéric ULg

in Journal of Dairy Science (2009), 92(E-suppl.1), 315

Currently efforts are underway to introduce molecular information into genetic evaluation systems. A particular situation is genomic selection however simpler cases exists where major genes are known and ... [more ▼]

Currently efforts are underway to introduce molecular information into genetic evaluation systems. A particular situation is genomic selection however simpler cases exists where major genes are known and used by breeders. A new alternative strategy for the prediction of gene effects and especially their smooth integration into genetic evaluations based on an equivalent method was developed from existing theory. Underlying hypothesis were based on the idea that knowledge of genotypes will not affect overall additive genetic variance but only change expected values of genetic effects for animals with known genotypes. The developed equations were modified to allow that not all animals were genotyped. As the underlying mixed model is open a very large range of models can be used in situations including random regression models, multipletrait, maternal effects and multiple-across-country-evaluation models. Computations involved successive solving of two mixed models, with the use of an linear extrapolation to speed up convergence of gene effects. The method was tested for several known major genes and QTL, e.g. for the mh gene in the dual-purpose Belgian Blue population in Belgium. Modifications of the method could also be developed to be useful in the context of genomic selection. [less ▲]

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See detailEquivalent mixed model for joint genetic evaluation considering molecular and phenotypic information
Gengler, Nicolas ULg; Colinet, Frédéric ULg

Conference (2009, July)

Currently efforts are underway to introduce molecular information into genetic evaluation systems. A particular situation is genomic selection however simpler cases exists where major genes are known and ... [more ▼]

Currently efforts are underway to introduce molecular information into genetic evaluation systems. A particular situation is genomic selection however simpler cases exists where major genes are known and used by breeders. A new alternative strategy for the prediction of gene effects and especially their smooth integration into genetic evaluations based on an equivalent method was developed from existing theory. Underlying hypothesis were based on the idea that knowledge of genotypes will not affect overall additive genetic variance but only change expected values of genetic effects for animals with known genotypes. The developed equations were modified to allow that not all animals were genotyped. As the underlying mixed model is open a very large range of models can be used in situations including random regression models, multipletrait, maternal effects and multiple-across-country-evaluation models. Computations involved successive solving of two mixed models, with the use of an linear extrapolation to speed up convergence of gene effects. The method was tested for several known major genes and QTL, e.g. for the mh gene in the dual-purpose Belgian Blue population in Belgium. Modifications of the method could also be developed to be useful in the context of genomic selection. [less ▲]

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See detailEquivalent static wind loads for structures with non-proportional damping
Blaise, Nicolas ULg; Canor, Thomas ULg; Denoël, Vincent ULg

in Zingoni, A (Ed.) Fifth International Conference on Structural Engineering, Mechanics & Computation (2013, September)

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See detailEquivalent static wind loads for structures with non-proportional damping
Blaise, Nicolas ULg; Canor, Thomas ULg; Denoël, Vincent ULg

in Proceedings of the 11th International Conference on Recent Advances in Structural dynamics (2013, July)

In current practice, wind structural design is often carried out using the concept of equivalent static wind loads. The main characteristic of such loadings is to reproduce, with static analyses, the same ... [more ▼]

In current practice, wind structural design is often carried out using the concept of equivalent static wind loads. The main characteristic of such loadings is to reproduce, with static analyses, the same extreme structural responses as those resulting from a formal buffeting analysis. This paper proposes a method for the computation of equivalent static wind loads for structures with slight non-proportional damping in a modal framework. Because of the smallness of the out-of diagonal terms, this method is based on recent developments related to asymptotic expansion of the modal transfer matrix of such structures. As a main benefit, the static loading is described as a perturbation of the equivalent loading that would be obtained for the uncoupled system. The main contribution of this paper is to formalize the expression of the correction terms resulting from the non-proportionality of damping. The method is presented with a detailed illustrative example. [less ▲]

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See detailEquivariant quantization in supergeometry
Radoux, Fabian ULg

Scientific conference (2011, December 08)

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See detailEquivariant quantization of orbifolds
Poncin, Norbert; Radoux, Fabian ULg; Wolak, Robert

in Journal of Geometry & Physics (2010), 60(9), 1103-1111

Equivariant quantization is a new theory that highlights the role of symmetries in the relationship between classical and quantum dynamical systems. These symmetries are also one of the reasons for the ... [more ▼]

Equivariant quantization is a new theory that highlights the role of symmetries in the relationship between classical and quantum dynamical systems. These symmetries are also one of the reasons for the recent interest in quantization of singular spaces, orbifolds, stratified spaces, etc. In this work, we prove the existence of an equivariant quantization for orbifolds. Our construction combines an appropriate desingularization of any Riemannian orbifold by a foliated smooth manifold, with the foliated equivariant quantization that we built in Poncin et al. (2009) [19]. Further, we suggest definitions of the common geometric objects on orbifolds, which capture the nature of these spaces and guarantee, together with the properties of the mentioned foliated resolution, the needed correspondences between singular objects of the orbifold and the respective foliated objects of its desingularization. [less ▲]

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See detailEquivariant quantization of spin systems
Michel, Jean-Philippe ULg

in AIP Conference Proceedings (2010), 1307

We investigate the geometric and conformally equivariant quantizations of the super-cotangent bundle of a pseudo-Riemannian manifold (M,g), which is a model for the phase space of a classical spin ... [more ▼]

We investigate the geometric and conformally equivariant quantizations of the super-cotangent bundle of a pseudo-Riemannian manifold (M,g), which is a model for the phase space of a classical spin particle. This is a short review of our previous works. [less ▲]

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See detailEquivariant quantizations and Cartan connections
Mathonet, Pierre ULg

in Bulletin of the Belgian Mathematical Society Simon Stevin (2006), 13(5), 857-874

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See detailEquivariant symbol calculus for differential operators acting on forms
Boniver, Fabien; Hansoul, Sarah ULg; Mathonet, Pierre ULg et al

in Letters in Mathematical Physics (2002), 62(3), 219-232

We prove the existence and uniqueness of a projectively equivariant symbol map (in the sense of Lecomte and Ovsienko) for the spaces D_p of differential operators transforming p-forms into functions, over ... [more ▼]

We prove the existence and uniqueness of a projectively equivariant symbol map (in the sense of Lecomte and Ovsienko) for the spaces D_p of differential operators transforming p-forms into functions, over R^n. As an application, we classify the Vect(M)-equivariant maps from D_p to D_q over a smooth manifold M, recovering and improving earlier results of N. Poncin. This provides the complete answer to a question raised by P. Lecomte about the extension of a certain intrinsic homotopy operator. [less ▲]

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See detail"Er war ein Verlorener". Géza von Cziffra erinnert sich an Joseph Roth
Küpper, Achim ULg

in Literaturkritik.de (2006)

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See detailThe Er-Tr4 Monoclonal Antibody Recognizes Murine Thymic Epithelial Cells (Type 1) and Inhibits Their Capacity to Interact with Immature Thymocytes: Immuno-Electron Microscopic and Functional Studies
Defresne, Marie-Paule ULg; Nabarra, B.; van Vliet, E. et al

in Histochemistry (1994), 101(5), 355-63

The thymic stroma is heterogeneous with regard to cellular morphology and cellular function. In this study, we employed the monoclonal antibody ER-TR4 to characterize stromal cells at the ultrastructural ... [more ▼]

The thymic stroma is heterogeneous with regard to cellular morphology and cellular function. In this study, we employed the monoclonal antibody ER-TR4 to characterize stromal cells at the ultrastructural level. To identify the labelled cell type, we used two techniques: immunogold labelling on ultrathin frozen sections and immunoperoxidase staining on thick "vibratome" sections. ER-TR4 reacted with thymic Type 1 epithelial cells (according to our classification). A dense labelling appears in the cytoplasm of cortical cells using the two techniques. Immunogold labelling identified small cytoplasmic vesicles whereas the cytoplasm and the cell membrane seem to be labelled with the immunoperoxidase technique. ER-TR4 also identified isolated thymic nurse cells (TNC), and was observed in vitro to inhibit the capacity of some type 1 epithelial cells to establish interactions with immature thymocytes. This finding supports the hypothesis that the factor is involved in the formation of lymphoepithelial interactions within thymic nurse cells, and thus in the relations that immature thymocytes establish with the thymic microenvironment. [less ▲]

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See detailEradication de la leucose bovine enzootique en Belgique : estimation du temps nécessaire à l'assainissement des foyers découverts
Knapen, K.; Kerkhofs, P.; Palm, Rodolphe ULg et al

in Annales de Médecine Vétérinaire (1991), 135(4), 281-285

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See detailEradication of enzootic bovine leucosis based on the detection of the disease by the gp immunodiffusion test.
Mammerickx, Marc; Corman, A.; Burny, Arsène et al

in Annales de Recherches Vétérinaires = Annals of Veterinary Research (1978), 9(4), 885-894

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See detailErard de La Marck, mécène et collectionneur (1472-1538)
Adam, Renaud ULg

in La vie des musées : bulletin de l'association francophone des musées de Belgique (2006), 20

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See detailÉrasme de Rotterdam, Gratulatorius panegyricus ad principem Philippum archiducem austriae
Adam, Renaud ULg

in Bousmanne, Bernard; Thieffry, Sandrine; Wijsman, Hanno (Eds.) Philippe le Beau (1478-1506) : les trésors du dernier duc de Bourgogne : exposition : Bruxelles, Bibliothèque royale de Belqique, Chapelle de Nassau, du 3 novembre 2006 au 27 janvier 2007 : catalogue (2006)

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See detailErasmus militaire : européaniser la formation, former à l’européanisation
Paile, Sylvain ULg

in Revue Défense Nationale [=RDM] (2013), (Summer), 145-152

Detailed reference viewed: 9 (0 ULg)