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See detailVorsilbe
Münzberg, Franziska ULg

in Schierholz, Stefan J.; Dürscheid, Christa (Eds.) Grammatik - Formenlehre (2014)

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See detailnominales Präfix
Münzberg, Franziska ULg

in Schierholz, Stefan J.; Dürscheid, Christa (Eds.) Grammatik - Formenlehre (2014)

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See detailThe value of disturbance-tolerant cercopithecine monkeys as seed dispersers in degraded habitats
Albert, Aurélie; McConkey, Kim; Savini, Tommaso ULg et al

in Biological Conservation (2014), 170

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See detailIntroduction
Van Schuylenbergh, Patricia; Lanneau, Catherine ULg; Plasman, Pierre-Luc

in Van Schuylenbergh, Patricia; Lanneau, Catherine; Plasman, Pierre-Luc (Eds.) L'Afrique belge aux XIXe et XXe siècles. Nouvelles recherches et perspectives en histoire coloniale (2014)

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See detailAnalytic Model for The Motion About An Oblate Planet in The Presence Atmospheric Drag
Martinusi, Vladimir ULg; Dell'Elce, Lamberto ULg; Kerschen, Gaëtan ULg

in Advances in The Astronautical Sciences (2014)

The paper introduces a new model for the motion about an oblate planet under the influence of the atmospheric drag. Both qualitative and quantitative insights are revealed, as well as closed-form ... [more ▼]

The paper introduces a new model for the motion about an oblate planet under the influence of the atmospheric drag. Both qualitative and quantitative insights are revealed, as well as closed-form equations of motion. The main tool consists in averaging the effects of both perturbations (oblateness and drag), and deriving the variational equations for the vectorial orbital elements. The model is singularity-free and may serve as an initial guess for control problems, as well as an analytic propagator. [less ▲]

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See detailRobust rendez-vous planning using the scenario approach and differential flatness
Dell'Elce, Lamberto ULg; Kerschen, Gaëtan ULg

in Advances in the Astronautical Sciences (2014)

There is a growing interest in uncertainty handling in the spacecraft dynamics community. In particular, robust optimization of spacecraft maneuvers is regarded as an important challenge. This paper ... [more ▼]

There is a growing interest in uncertainty handling in the spacecraft dynamics community. In particular, robust optimization of spacecraft maneuvers is regarded as an important challenge. This paper proposes an optimal control approach for orbital rendez-vous planning under stochastic dynamics and constraints. The method combines differential flatness theory with the scenario approach for optimization under uncertainties. By mapping state and control variables into a set of flat outputs, the enforcement of dynamics equations and boundary conditions is automatically satisfied. The rigorous foundations of the scenario approach lead to a finite-dimensional formulation of the problem which guarantees the feasibility of the solution within an arbitrary portion of the stochastic domain. The methodology is illustrated by means of two case studies involving a rendez-vous in elliptic orbit and a propellantless maneuver using differential drag, respectively. [less ▲]

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See detailProcédure pénale
Michiels, Olivier ULg

Learning material (2014)

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See detailEnergies et minerais.Des ressources sous tension
Merenne-Schoumaker, Bernadette ULg

in La Documentation Photographique (2014), 8089

Les ressources non renouvelables sont sans conteste une clé de lecture de notre monde contemporain, de ses tensions et de ses défis. Ces ressources sont « sous tension » car leur demande est en forte ... [more ▼]

Les ressources non renouvelables sont sans conteste une clé de lecture de notre monde contemporain, de ses tensions et de ses défis. Ces ressources sont « sous tension » car leur demande est en forte croissance. Leur géopolitique ne cesse d’évoluer. Ainsi, le pétrole et le gaz de schiste américains bouleversent les équilibres mondiaux, alors que le charbon fait un retour en force. L’enjeu est aussi environnemental et sociétal. [less ▲]

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See detailSnijders’ correction of Infit and Outfit indexes with estimated ability level : an analysis with the Rasch model
Magis, David ULg; Béland, Sébastien; Raîche, Gilles

in Journal of Applied Measurement (2014), 15

The Infit mean square W and the Outfit mean square U are commonly used person fit indexes under Rasch measurement. However, they suffer from two major weaknesses. First, their asymptotic distribution is ... [more ▼]

The Infit mean square W and the Outfit mean square U are commonly used person fit indexes under Rasch measurement. However, they suffer from two major weaknesses. First, their asymptotic distribution is usually derived by assuming that the true ability levels are known. Second, such distributions are even not clearly stated for indexes U and W. Both issues can seriously affect the selection of an appropriate cut-score for person fit identification. Snijders (2001) proposed a general approach to correct some person fit indexes when specific ability estimators are used. The purpose of this paper is to adapt this approach to U and W indexes. First, a brief sketch of the methodology and its application to U and W is proposed. Then, the corrected indexes are compared to their classical versions through a simulation study. The suggested correction yields controlled Type I errors against both conservatism and inflation, while the power to detect specific misfitting response patterns gets significantly increased. [less ▲]

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See detailExercise and immunity in horses
Art, Tatiana ULg

in Hinchcliff, Kenneth W.; Kaneps, Andres J.; Geor, Raymond J. (Eds.) Equine Sports Medicine and Surgery. Basic and clinical Sciences of the Equine Athlete. 2d Edition (2014)

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See detailResidence time vs influence time
Delhez, Eric ULg; de Brye, Bejamin; de Brauwere, Anouk et al

in Journal of Marine Systems (2014), 132

The concepts of age, residence time, exposure time and influence time provide space and time dependent quantitative measures of the rate at which watermasses and pollutants enter and/or leave a control ... [more ▼]

The concepts of age, residence time, exposure time and influence time provide space and time dependent quantitative measures of the rate at which watermasses and pollutants enter and/or leave a control domain. To help avoid confusion between these concepts, this paper provides clear definitions of the residence time and the influence time. The similarities and differences between them are illustrated using both a simplified 1D advection–diffusion model and a realistic two-dimensional model of the Scheldt Estuary (Belgium and the Netherlands). The residence time of a water parcel in a control domain is the time taken by this parcel to leave the control domain for the first time. The influence time is the time required to replace the water in the domain of interest by renewing water. For steady flows, the influence time is numerically identical to the age of the renewing water, but the two timescales differ for unsteady flows. The residence timemeasures the influence of a hypothetical point discharge on a control domain. In environmental studies, it provides a measure of the effectiveness of hydrodynamic processes at helping a semi-enclosed basin to recover froma local pollution event. The influence time quantifies the local influence of a tracer that would be uniformly distributed in the control domain at the initial time. It is therefore a relevant diagnostic tool in impact studies focusing on the local persistence of a pollution problem. [less ▲]

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See detailComment dépolluer des eaux usées grâce à la lumière du soleil ?
Heinrichs, Benoît ULg

Learning material (2014)

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See detailcomment j'explore les infections nosocomiales en néonatologie
Dachy, Angélique ULg; Battisti, Oreste ULg

in Revue Médicale de Liège (2014)

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See detailL’Alfier nero (Le Fou noir) d’Arrigo Boito – Lecture anthropologique et poétologique d’un combat d’échecs.
Leyh, Valérie ULg

in Achim Küpper, Kristine Vanden Berghe (Ed.) Guerre et jeu. Cultures d’un paradoxe à l’ère moderne (2014)

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See detailThe diet of the Harlequin crab Lissocarcinus orbicularis, an obligate symbiont of sea cucumbers (holothuroids) belonging to the genera Thelenota, Bohadschia and Holothuria
Caulier, Guillaume; Lepoint, Gilles ULg; Van Nedervelde, Fleur et al

in Symbiosis (2014)

The present paper characterizes, for the first time, the diet of the Harlequin crab, Lissocarcinus orbicularis an obligate symbiotic crab that associates with sea cucumbers (holothuroids) belonging to the ... [more ▼]

The present paper characterizes, for the first time, the diet of the Harlequin crab, Lissocarcinus orbicularis an obligate symbiotic crab that associates with sea cucumbers (holothuroids) belonging to the genera Thelenota, Bohadschia and Holothuria. These tropical holothuroids host a rich symbiotic community in the Indo-West Pacific Ocean of which the Harlequin crab is the best known. The diet of L. orbicularis was characterized by analyzing the microscopic, molecular and isotopic signatures obtained from its gastric content. The presence of sea cucumber ossicles in the gastric mills of the crabs suggests that symbionts eat the superficial integument of their host and this was suppoarted by the fact that Holothuroid DNA was detected in the stomach of L.orbicularis after DGGE and sequencing of the 18S rDNA gene. The stable isotopic δ13C and δ15N values of crab tissues were compared with diverse potential food sources including the three holothuroids, three algae, one sea grass as well as the organic matter contained in the water column, in the sediment, and the second most abundant symbiont, the polychaete Gastrolepidia clavigera. The low δ15N values of crabs suggest that the crabs do not exclusively feed on sea cucumber tissue but assimilate diverse food sources such as sea grasses and organic matter contained in sediment that have similar δ13C values. There were no difference between the feeding of males and females but there was a positive correlation between the carapace length and the stable isotopic values indicating a shift of the food source as crabs grow larger. [less ▲]

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See detailPhotic memory for executive brain responses
Chellappa*, Sarah Laxhmi ULg; Ly*, Julien ULg; Meyer, Christelle ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (2014), Epub ahead of print

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See detailGeometric ferroelectricity in fluoroperovskites
Garcia-Castro, A. C.; Spaldin, Nicola A.; Romero, A. H. et al

in Physical Review B (2014), 89

We used first-principles calculations to investigate the existence and origin of the ferroelectric instability in the ABF3 fluoroperovskites. While the ground states of most ABF3 compounds are ... [more ▼]

We used first-principles calculations to investigate the existence and origin of the ferroelectric instability in the ABF3 fluoroperovskites. While the ground states of most ABF3 compounds are paraelectric (Pnma phase), we find that many fluoroperovskites have a ferroelectric instability in their high-symmetry cubic structure that is of similar amplitude to that commonly found in oxide perovskites. In contrast to the oxides, however, the fluorides have nominal Born effective charges, indicating a different mechanism for the instability.We show that the instability originates from ionic size effects, and is therefore in most cases largely insensitive to pressure and strain, again in contrast to the oxide perovskites. An exception is NaMnF3, where coherent epitaxial strain matching to a substrate with equal in-plane lattice constants destabilizes the bulk Pnma structure, leading to a ferroelectric, and indeed multiferroic, ground state with an unusual polarization/strain response. [less ▲]

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