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See detailMaximal Ventilation Assessment in Healthy Calves
Bureau, Fabrice ULg; Coghe, J.; Uystepruyst, C. H. et al

in Veterinary Journal (1999), 157(3), 309-314

In order to define a reliable method for estimating maximal ventilation in cattle, 12 healthy calves underwent a rebreathing trial and injections of increasing doses of lobeline, a respiratory analeptic ... [more ▼]

In order to define a reliable method for estimating maximal ventilation in cattle, 12 healthy calves underwent a rebreathing trial and injections of increasing doses of lobeline, a respiratory analeptic. The effects of these tests on the main ventilatory parameters (tidal volume, VT; respiratory frequency, fR and minute volume,.VE) recorded during the 15 s of maximal response were studied and compared. The sharp rise in.VE(4.8 times higher than the resting value) observed during the rebreathing trial was mainly due to an increase in VT. This rise in ventilation was the highest ever reported in calves. Lobeline dose-dependently enhanced ventilation up to a threshold dose of 0.25 mg/kg, which always produced a maximal response. This maximal response (3.7 times higher than the resting value), reflecting both an increase in fR and VT, was reproducible at an interval of 12 h and was highly correlated with that observed during the rebreathing trial (R = 0.98, P< 0.001). These results suggest that: (1) rebreathing trial is a reliable method to induce and measure maximal ventilation in calves; and (2) lobeline administration (0.25 mg/kg) is a reliable means of accurately estimating this variable. Lobeline administration, unlike the rebreathing trial, is safe and easy to standardize, and the test therefore seems to be the preferred way of studying maximal ventilation in calves. [less ▲]

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See detailMaximal ventilation in calves : assessment and prediction
Bureau, Fabrice ULg; Coghe, J.; Uystepruyst, Ch et al

in Proceedings: XX Congress of the World Association for Buiatrics (1998)

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See detailMaximalisme poétique et poétique maximaliste
Delville, Michel ULg

Scientific conference (2003, February 11)

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See detailMAXIMIZATION OF PULL-IN VOLTAGE OF MICRO-ELECTROMECHANICAL STRUCTURES USING TOPOLOGY OPTIMIZATION
Lemaire, Etienne ULg; Rochus, Véronique ULg; Fleury, Claude ULg et al

Conference (2006)

The design problem consists in maximizing the pull-in voltage using topology optimization method, which is formulated as an optimal material distribution. In addition to the classical volume constraint ... [more ▼]

The design problem consists in maximizing the pull-in voltage using topology optimization method, which is formulated as an optimal material distribution. In addition to the classical volume constraint, different structural constraints could be taken into consideration. Sensitivity analysis is one of the key issues of the optimization process and is performed with the formulation of eigenvalue topology optimization problems. Here the paper investigates topology optimization of strongly coupled electromechanical systems. To avoid important modifications of the electric field by the optimization process, this first study considers a non design electrode and use topology optimization to design an optimal suspension structure. Solution procedure of the optimization problem is based on CONLIN optimizer using a sequential convex programming. This method that has proved its efficiency in many structural problems (sizing, shape) is here tailored to strongly coupled multiphysics design problems under consideration. The choice of appropriate explicit convex approximations schemes for multiphysic problems is investigated. The proposed method is illustrated and validated on microbeam optimization applications. [less ▲]

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See detailThe maximum deviation just-in-time scheduling problem
Brauner, Nadia; Crama, Yves ULg

in Discrete Applied Mathematics (2004), 134(1-3), 25-50

This note revisits the maximum deviation just-in-time (MDJIT) scheduling problem previously investigated by Steiner and Yeomans. Its main result is a set of algebraic necessary and sufficient conditions ... [more ▼]

This note revisits the maximum deviation just-in-time (MDJIT) scheduling problem previously investigated by Steiner and Yeomans. Its main result is a set of algebraic necessary and sufficient conditions for the existence of a MDJIT schedule with a given objective function value. These conditions are used to provide a finer analysis of the complexity of the MDJIT problem. The note also investigates various special cases of the MDJIT problem and suggests several questions for further investigation. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailMaximum entropy approach to the identification of stochastic reduced-order models of nonlinear dynamical systems
Arnst, Maarten ULg; Ghanem, Roger; Masri, Sami

in Aeronautical Journal (2010), 114(1160), 637-650

Data-driven methodologies based on the restoring force method have been developed over the past few decades for building predictive reduced-order models (ROMs) of nonlinear dynamical systems. These ... [more ▼]

Data-driven methodologies based on the restoring force method have been developed over the past few decades for building predictive reduced-order models (ROMs) of nonlinear dynamical systems. These methodologies involve fitting a polynomial expansion of the restoring force in the dominant state variables to observed states of the system. ROMs obtained in this way are usually prone to errors and uncertainties due to the approximate nature of the polynomial expansion and experimental limitations. We develop in this article a stochastic methodology that endows these errors and uncertainties with a probabilistic structure in order to obtain a quantitative description of the proximity between the ROM and the system that it purports to represent. Specifically, we propose an entropy maximization procedure for constructing a multi-variate probability distribution for the coefficients of power-series expansions of restoring forces. An illustration in stochastic aeroelastic stability analysis is provided to demonstrate the proposed framework. [less ▲]

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See detailMaximum entropy at intermediate anthropogenic dynamics
Vranken, Isabelle ULg; Bogaert, Jan ULg

in Jones, Bruce; Fu, Bojie (Eds.) The 8th World congress of the International Association of Landscape Ecology: Proceedings, Beijing, August 18-23, 2011 (2011, August 20)

Landscape entropy represents heterogeneity within a landscape (Renyi, 1961; Bogaert et al., 2005). Previous researches found increasing values of entropy by studying a limited number of zones increasingly ... [more ▼]

Landscape entropy represents heterogeneity within a landscape (Renyi, 1961; Bogaert et al., 2005). Previous researches found increasing values of entropy by studying a limited number of zones increasingly affected by anthropogenic effect (O’Neill et al., 1988; Bogaert et al., 2005). The present research aims to generalise the relationship between anthropogenic effect and landscape entropy, with a further goal of linking these concepts to overall biodiversity. 16 study zones from classified LANDSAT TM scenes and Africover maps presenting different anthropogenic effect intensities have been used (Djibu et al., 2008; Bamba et al., 2010; Barima et al., 2010; Munyemba, 2010; Vranken et al., 2011). Simpson's H diversity index based on class number has been used for entropy measurement (Renyi, 1961; Pielou, 1975; Shannon and Weaver, 1963). 1-H has been retained to get the relationship between the index and diversity directly proportional. For anthropogenic effect measurement, O’Neill’s U disturbance index, quotient between anthropogenic and natural areas, has been used (O’Neill et al., 1988). Log H has been retained to linearise the exponential relationship between the index and anthropogenic effect. Correlation between those variables has then been analysed. The scatter plot of the 16 study zones shows a Gaussian curve (Fig. 1) presenting maximal landscape entropy at intermediate anthropogenic effect. This distribution has been modelled by a second order polynomial regression with determination coefficient and significance. This phenomenon has been interpreted in terms of spatial transformation processes (Bogaert et al., 2004) and linked to the habitat heterogeneity hypothesis (Tews, 2004), as well as the intermediate disturbance hypothesis (Connell, 1978; Lindenmayer and Brugman, 2005). [less ▲]

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See detailMaximum entropy production: can it be used to constrain conceptual hydrological models?
Westhoff, Martijn ULg; Zehe, E.

in Hydrology and Earth System Sciences (2013), 17(8), 3141--3157

This work builds on earlier work by Kleidon and Schymanski (2008) who explored the use of the maximum entropy production (MEP) principle for modeling hydrological systems. They illustrated that MEP can be ... [more ▼]

This work builds on earlier work by Kleidon and Schymanski (2008) who explored the use of the maximum entropy production (MEP) principle for modeling hydrological systems. They illustrated that MEP can be used to determine the partitioning of soil water into runoff and evaporation—which determines hydroclimatic conditions around the Globe—by optimizing effective soil and canopy conductances in a way to maximize entropy production by these fluxes. In the present study, we show analytically that under their assumption of constant rainfall, the proposed principle always yields an optimum where the two conductances are equal, irrespective of rainfall rate, evaporative demand, or gravitational potential. Subsequently, we show that under periodic forcing or periodic variations in one resistance (e.g., vegetation seasonality), the optimal conductance does depend on climatic drivers such as the length of dry spells or the time of closure of stomata. [less ▲]

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See detailMaximum likelihood range dependence compensation for STAP
Neyt, Xavier; Acheroy, Marc; Verly, Jacques ULg

Conference (2007)

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See detailTHE MAXIMUM-ENTROPY PRODUCTION PRINCIPLE IN CLIMATE MODELS - APPLICATION TO THE FAINT YOUNG SUN PARADOX
Gérard, Jean-Claude ULg; DELCOURT, D.; François, Louis ULg

in Quarterly Journal Of The Royal Meteorological Society (1990), 116(495), 1123-1132

Current theories of stellar evolution imply that the solar luminosity was 25-30% less than at present during early phases of the Earth's history. The response of the global annual climate to changes of ... [more ▼]

Current theories of stellar evolution imply that the solar luminosity was 25-30% less than at present during early phases of the Earth's history. The response of the global annual climate to changes of the solar input is examined using the maximum entropy production (MEP) principle and a zonal energy balance model including ice-albedo feedback. It is shown that this formulation reproduces satisfactorily the present meridional heat flux and latitudinal temperature distributions. It is found that the model predicts that the efficiency of the meridional heat transport decreases for low values of the solar constant. Consequently, if the solar irradiance is lowered, a progressive development of the polar caps and a decrease of the global surface temperature are obtained without major irreversibility in the system. A comparison with a similar model including diffusive heat transport formalism shows that the value of the critical solar luminosity causing a global glaciation is decreased when the meridional heat fluxes are determined by the MEP principle. [less ▲]

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See detailMaximum-likelihood Based Range-dependence Compensation for Coherent Multistatic STAP-based Radar
Neyt, Xavier; Acheroy, Marc; Verly, Jacques ULg

Conference (2007)

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See detailMaximum-likelihood reconstruction with ordered subsets in bone SPECT
Blocklet, Didier; Seret, Alain ULg; Popa, Niculaie et al

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (1999), 40(12), 1978-1984

This study was aimed at determining whether the ordered-subset expectation maximum (OSEM) is more effective than filtered backprojection (FBP) for bone SPECT in the routine clinical context. Methods ... [more ▼]

This study was aimed at determining whether the ordered-subset expectation maximum (OSEM) is more effective than filtered backprojection (FBP) for bone SPECT in the routine clinical context. Methods. Fifty-seven consecutive bone SPECT studies were analyzed. They included pelvic and lumbar spine, thoraco lumbar spine, head and neck, feet and shoulders. A 64-projection SPECT study was acquired over 360° by single-head cameras 2–3h after the injection of 750 MBq 99mTc-methylene diphosphonate. Three observers compared the OSEM and FBP reconstructed images. Results. Streak artifacts, always present with FBP, were rarely generated with the OSEM. When present (n = 24), artifacts associated with negative values near hyperactivities in FBP were not generated with the OSEM in 67% of the cases (n = 16), permitting a satisfactory interpretation of these regions. In half of the other cases (17%, n = 4/24), interpretation was precluded. In only one case did the three observers agree that more hyperactivities were seen with the OSEM. Ninety-six percent of the OSEM pictures were superior or equal to FBP for anatomic resolution and were clearly better in 12% of the cases. The extent of the lesion with the OSEM seemed better or equally defined in 96% and clearly better in 14% of the cases. The low-activity regions were better or equally visualized in all cases and were clearly better seen in 23% of the cases. The quality of the pictures was found to be better or superior with the OSEM in 98% of the cases and definitely better in 65% of the cases. Conclusion: Replacement of FBP by the OSEM in bone SPECT would be beneficial to clinical practice. [less ▲]

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See detailMaxwell rigidity and topological constraints in amorphous phase-change networks
Micoulaut, M.; Otjacques, C.; Raty, Jean-Yves ULg et al

in AIP Conference Proceedings (2011), 1393

By analyzing first-principles molecular-dynamics simulations of different telluride amorphous networks, we develop a method for the enumeration of radial and angular topological constraints, and show that ... [more ▼]

By analyzing first-principles molecular-dynamics simulations of different telluride amorphous networks, we develop a method for the enumeration of radial and angular topological constraints, and show that the phase diagram of the most popular system Ge-Sb-Te can be split into two compositional elastic phases: a tellurium rich flexible phase and a stressed rigid phase that contains most of the materials used in phase-change applications. This sound atomic scale insight should open new avenues for the understanding of phase-change materials and other complex amorphous materials from the viewpoint of rigidity. [less ▲]

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See detailThe May 4, 2013 Stellar Occultation by Pluto and Implications for Pluto's Atmosphere
Olkin, Catherine B.; Young, L. A.; Borncamp, D. et al

in Bulletin of the American Astronomical Society (2013, October 01), 45

On May 4 2013, Pluto passed in front of a 14 star and the shadow was well observed from multiple occultation groups. This paper presents results from the three light curves observed at Las Cumbres ... [more ▼]

On May 4 2013, Pluto passed in front of a 14 star and the shadow was well observed from multiple occultation groups. This paper presents results from the three light curves observed at Las Cumbres Observatory Global Telescope Network (LCOGT) from their Cerro Tololo site. The three LCOGT telescopes have 1.0 m apertures and used identical frame-transfer cameras. The cameras currently have a 2 second readout time therefore autonomous observations were scheduled with different exposure times to give good time resolution of the event. We will present results of this occultation and compare occultation results from 1988 to 2013 with volatile transport models. [less ▲]

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See detailMay rare metallophytes benefit from disturbed soils following mining activities ? The case of the Crepidorhopalon tenuis in Katanga (D.R. COngo)
Faucon, Michel Pierre; Parmentier, Ingrid; Collinet, Gilles et al

in Restoration Ecology (2009)

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See detailMay Rare Metallophytes Benefit from Disturbed Soils Following Mining Activity? The Case of the Crepidorhopalon tenuis in Katanga (D. R. Congo)
Faucon, Michel-Pierre; Parmentier, Ingrid; Colinet, Gilles ULg et al

in Restoration Ecology (2011), 19

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See detailThe May-July 1989 Crisis of V348 Sgr
Manfroid, Jean ULg; Houziaux, Léo ULg

in Information Bulletin on Variable Stars (1989), 3375

Not Available

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See detailMaya blue-green pigments found in Calakmul, Mexico: a study by Raman and UV-visible spectroscopy
Moreno, Renata Garcia; Strivay, David ULg; Gilbert, Bernard ULg

in Journal Of Raman Spectroscopy (2008), 39(8), 1050-1056

After more than two decades of fieldwork in the Maya archaeological site of Calakmul, Mexico, numerous remnants of blue and green pigments have been reported on wall paintings, as well as on funerary ... [more ▼]

After more than two decades of fieldwork in the Maya archaeological site of Calakmul, Mexico, numerous remnants of blue and green pigments have been reported on wall paintings, as well as on funerary paraphernalia, such as masks, miniatures and vases. The importance of these pigments is linked to the sacred values that Maya people associate with blue and green colours since pre-Columbian times. These hues symbolise water, and are therefore associated with fertility and regeneration. This paper aims to perform a survey of the blue and green pigments used in the Early Classic and Late Classic periods in Calakmul (300-850 A.D.), in order to have a better understanding of their chemical composition and origin. Analyses were performed on microsamples using Raman and UV-visible spectroscopies to evaluate the possibilities that these techniques can offer in future in situ researches on Mesoamerican archaeological materials and objects. With these analyses, we have documented a large blue-green chromatic palette, which includes the earliest Blue Maya and Green Maya known to date, as well as malachite, pseudomalachite and an unknown-up-to-now blue-green mineral pigment, veszelyite, used specifically for ritual objects. The results indicate a careful selection of imported products and the mastering of a complex ancient Maya pictorial tradition. Copyright (c) 2008 John Wiley & Sons, Ltd. [less ▲]

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