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Note on the numerical solution of the scalar Helmholtz equation in a nanotorus with uniform Dirichlet boundary conditions Nguyen, Ngoc Duy ; Evrard, Roger ; E-print/Working paper (2016) This note describes the solution of the Helmholtz equation inside a nanotorus with uniform Dirichlet boundary conditions. The eigenfunction symmetry is discussed and the lower-order eigenvalues and ... [more ▼] This note describes the solution of the Helmholtz equation inside a nanotorus with uniform Dirichlet boundary conditions. The eigenfunction symmetry is discussed and the lower-order eigenvalues and eigenfunctions are shown. The similarity with the case of a long cylinder and with that of the vibrations of a circular elastic membrane is discussed. This similarity is used to propose a classification scheme of the eigenfunctions based on three indices. [less ▲] Detailed reference viewed: 22 (1 ULg)A Note On The Rate Of Passage Of Digesta In Pigs Ileo-Rectostomized Or Fitted With An Ileal T-Cannula ; ; Thewis, André et al in Animal Production (1991), 53(2), 253-256 Detailed reference viewed: 9 (0 ULg)A note on the response to simple shear of elasto-plastic materials with isotropic hardening Cescotto, Serge ; Habraken, Anne in European Journal of Mechanics A : Solids (1991), 10(1), 1-13 Detailed reference viewed: 21 (2 ULg)A note on the resting behaviour of cows before and after calving in two different housing systems ; Nicks, Baudouin ; et al in Applied Animal Behaviour Science (1989), 23(1-2), 99-105 Detailed reference viewed: 10 (0 ULg)A note on the size-fractionated pigments of the phytoplankton of the Strait of Magellan (February-March 1991) ; ; et al in Oebalia : International Journal of Marine Biology and Oceanography (1994), XX During an oceanographic cruise, carried out at the end of the austral summer (February-March 1991) in the Strait of Magellan, spatial patterns of size-fractionated chlorophyll and primary production were ... [more ▼] During an oceanographic cruise, carried out at the end of the austral summer (February-March 1991) in the Strait of Magellan, spatial patterns of size-fractionated chlorophyll and primary production were studied in relation to hydrographic patterns. Phytoplankton biomass, in terms of active Chl a, ranged between 10 and 51 mg m-2 and primary production between 275 and 1 170 mg C m-2 d-1. The most important features concern the confinement of the microphytoplanktonic fraction to the Pacific opening and to the embayements between the two Narrows. In the internal part of the Strait, an uniform dimensional structure (< 5 um) of phytoplankton communities was observed, with the picophytoplanktonic fraction always dominant. [less ▲] Detailed reference viewed: 44 (2 ULg)A note on the use of fluorescently labelled algae for the determination of gut passage time in Bosmina and Daphnia Cauchie, Henry-Michel ; ; Joaquim-Justo, Célia et al in Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie = Proceedings of the International Association of Theoretical and Applied Limnology (2001), 27 Detailed reference viewed: 55 (5 ULg)A Note on the Use of the Modified Value-at-Risk Cavenaile, Laurent ; Lejeune, Thomas in Journal of Alternative Investments (2012), 14(4), 79-83 While the Modified Value-at-Risk (or Cornish Fisher Value-at-Risk) has been quite extensively used by practitioners and academics since its introduction, we show that it can be consistently used only over ... [more ▼] While the Modified Value-at-Risk (or Cornish Fisher Value-at-Risk) has been quite extensively used by practitioners and academics since its introduction, we show that it can be consistently used only over a limited interval of confidence level. Confidence level below 95.84% should never be used for the Modified Value-at-Risk to be consistent with investors' preferences for kurtosis. In addition, the use of higher confidence level is restricted by the value of the skewness. Failure to respect these restrictions on confidence levels results in mistakenly assessing assets' risk and potentially in overweighting assets which exhibit undesirable properties in terms of higher moments. [less ▲] Detailed reference viewed: 107 (18 ULg)Note on topology optimization of continuum structures including self-weight Bruyneel, Michaël ; Duysinx, Pierre in Structural and Multidisciplinary Optimization (2005), 29 Detailed reference viewed: 13 (0 ULg)Note on topology optimization of continuum structures including self-weight ; Duysinx, Pierre in Structural and Multidisciplinary Optimization (2005), 29(4), 245-256 This paper proposes to investigate topology optimization with density-dependent body forces and especially self-weight loading. Surprisingly the solution of such problems cannot be based on a direct ... [more ▼] This paper proposes to investigate topology optimization with density-dependent body forces and especially self-weight loading. Surprisingly the solution of such problems cannot be based on a direct extension of the solution procedure used for minimum-compliance topology optimization with fixed external loads. At first the particular difficulties arising in the considered topology problems are pointed out: non-monotonous behaviour of the compliance, possible unconstrained character of the optimum and the parasitic effect for low densities when using the power model (SIMP). To get rid of the last problem requires the modification of the power law model for low densities. The other problems require that the solution procedure and the selection of appropriate structural approximations be revisited. Numerical applications compare the efficiency of different approximation schemes of the MMA family. It is shown that important improvements are achieved when the solution is carried out using the gradient-based method of moving asymptotes (GBMMA) approximations. Criteria for selecting the approximations are suggested. In addition, the applications also provide the opportunity to illustrate the strong influence of the ratio between the applied loads and the structural weight on the optimal structural topology. [less ▲] Detailed reference viewed: 90 (6 ULg)A note on trust-region radius update ; Delhez, Eric in SIAM Journal on Optimization (2005), 16(2), 548-562 In classical trust-region optimization algorithms, the radius of the trust region is reduced, kept constant, or enlarged after, respectively, unsuccessful, successful, and very successful iterations. We ... [more ▼] In classical trust-region optimization algorithms, the radius of the trust region is reduced, kept constant, or enlarged after, respectively, unsuccessful, successful, and very successful iterations. We propose here to re. ne the empirical rules used for this update by the definition of a new set of iterations that we call "too successful iterations." At such iterations, a large reduction of the objective function is obtained despite a crude local approximation of the objective function; the trust region is thus kept nearly constant instead of being enlarged. The new update rules preserve the strong convergence property of traditional trust-region methods. They can also be generalized to define a self-adaptive trust-region algorithm along the lines introduced by Hei [J. Comput. Math., 21 (2003), pp. 229-236]. Numerical experiments carried out on 70 unconstrained problems from the CUTEr collection demonstrate the positive impact of the modified update strategy on the efficiency and robustness of quasi-Newton variants of a trust-region solver, when BFGS or SR1 updates of the approximation of the Hessian matrix are carried at all iterations. [less ▲] Detailed reference viewed: 63 (9 ULg)A Note on Two Be Stars ; Manfroid, Jean in Information Bulletin on Variable Stars (1982), 2198 Detailed reference viewed: 6 (0 ULg)A note on weighted likelihood and Jeffreys modal estimation of proficiency levels in polytomous item response models Magis, David in Psychometrika (2015), 80 Warm (1989) established the equivalence between the so-called Jeffreys modal and the weighted likelihood estimators of proficiency level with some dichotomous item response models. The purpose of this ... [more ▼] Warm (1989) established the equivalence between the so-called Jeffreys modal and the weighted likelihood estimators of proficiency level with some dichotomous item response models. The purpose of this note is to extend this result to polytomous item response models. First, a general condition is derived to ensure the perfect equivalence between these two estimators. Second, it is shown that this condition is fulfilled by two broad classes of polytomous models including, among others, the partial credit, rating scale, graded response and nominal response models. [less ▲] Detailed reference viewed: 41 (7 ULg)Note préliminaire sur la constitution de la bande silurienne de Sambre-et-Meuse Malaise, Constantin in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1897), 3e série(33), 803-809 Detailed reference viewed: 5 (1 ULg)Note préliminaire sur la propriété que possèdent les fragments des corps solides de se souder par l'action de la pression Spring, Walthère in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique. Sciences. 2e série (1878), XLV(6), 746-754 Detailed reference viewed: 14 (0 ULg)Note préliminaire sur les trois périodes de la variation des latitudes Folie, François in Bulletins de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique (1897), 3e série, t. 34(8), 238-247 The author wants to determine his choice for the latitude variations period and introduces his theory about the diurnal nutation. Detailed reference viewed: 2 (0 ULg)Note relative à l'histoire de la lecture wallonne au XVIIIe siècle Droixhe, Daniel in Livre et l'estampe (Le) (1984), 30 Detailed reference viewed: 12 (2 ULg)Note sous Anvers, 23 juin 1999 Orban, Lionel in Actualités du Droit (1999) Detailed reference viewed: 5 (0 ULg)note sous arrêt du 18 septembre 2003, Volkswagen AG c/ Commission Petit, Nicolas in Revue du Droit de l'Union Européenne (2003) résumé et analyse de l'affaire Volkswagen AG contre Commission, affaire C-338/00 Detailed reference viewed: 44 (1 ULg)note sous arrêt du 23 octobre 2003, Van den Bergh Foods contre Commission Petit, Nicolas in Revue du Droit de l'Union Européenne (2003) résumé et analyse de l'affaire Volkswagen AG contre Commission, affaire C-338/00 Detailed reference viewed: 40 (3 ULg)note sous arrêt du 4 mars 2003 "FENIN c/ Commission" Petit, Nicolas in Revue du Droit de l'Union Européenne (2004) Résumé et analyse de l'affaire FENIN contre Commission (affaire T-399/99) Detailed reference viewed: 95 (3 ULg) |
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