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See detailA damage/repair model for alveolar bone remodeling
Mengoni, Marlène ULg; Ponthot, Jean-Philippe ULg

in Middleton; Evans; Holt (Eds.) et al 8th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering : CMBBE2008, Porto, Porugal (2008)

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See detailDie Dämonie von Verlassenheit und Fremde in den Erzählungen Stefan Zweigs
Küpper, Achim ULg

Scientific conference (2006, October 20)

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See detailDie Dämonie von Verlassenheit und Fremde in den Erzählungen Stefan Zweigs. Abstract
Küpper, Achim ULg

in Stefan Zweig und das Dämonische: Abstracts (2006)

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See detailDamped LYalpha Absorbers and Gravitational Lensing
Smette, Alain; Claeskens, Jean-François ULg; Surdej, Jean ULg

in Structure and Evolution of the Intergalactic Medium from QSO Absorption Line System, Proceedings of the 13th IAP Astrophysics Colloquium (1997)

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See detailDamping control by fusion of reinforcement learning and control Lyapunov functions
Glavic, Mevludin; Wehenkel, Louis ULg; Ernst, Damien ULg

in Proceedings of the 38th North American Power Symposium (NAPS 2006) (2006)

The main idea behind the concept, proposed in the paper, is the opportunity to make control systems with increased capabilities by synergetic fusion of the domain-specific knowledge and the methodologies ... [more ▼]

The main idea behind the concept, proposed in the paper, is the opportunity to make control systems with increased capabilities by synergetic fusion of the domain-specific knowledge and the methodologies from control theory and artificial intelligence. The particular approach considered combines Control Lyapunov Functions (CLF), a constructive control technique, an Reinforcement Learning (RL) in attempt to optimize a mix of system stability and performance. Two control schemes are proposed and the capabilities of the resulting controllers are illustrated on a control problem involving a Thyristor Controlled Series Capacitor (TCSC) for damping oscillations in a four-machine power system. [less ▲]

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See detailDamping identification in a non-linear aeroelastic structure
Vio, Gareth A.; Prandina, Marco; Dimitriadis, Grigorios ULg

in Proceedings of ISMA2010 (2010, September 20)

An energy-based method is proposed to identify damping parameters from time histories of responses to sets of single-frequency harmonic excitation. The method is intended to be practically applicable to ... [more ▼]

An energy-based method is proposed to identify damping parameters from time histories of responses to sets of single-frequency harmonic excitation. The method is intended to be practically applicable to real structures and is able to identify the value of viscous damping, Coulomb friction and eventually other forms of non-linear damping models in aeroelastic systems. The inputs required are simply the accelerometer signals and the forces applied. It will be shown that if the system is undergoing Limit Cycle Oscillations, no external force is required for the identification process. [less ▲]

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See detailDamping identification of lightly damped linear dynamic systems using Common-base Proper Orthogonal Decomposition
Andrianne, Thomas ULg; Dimitriadis, Grigorios ULg

in Mechanical Systems & Signal Processing (2012), 28

This paper presents a new technique to identify the damping of linear systems. It is developed from the Proper Orthogonal Decomposition (POD) of the free response of the system and extended to the ... [more ▼]

This paper presents a new technique to identify the damping of linear systems. It is developed from the Proper Orthogonal Decomposition (POD) of the free response of the system and extended to the recently proposed Common-base POD (CPOD). The present application of CPOD considers simultaneously several free responses of the system to different initial conditions. The eigen-decomposition of the co-variance matrix leads to a unique vector basis which is likely to contain more information about the dynamics of the system than a vector basis obtained by the classic POD technique. The ability of the technique to estimate the mode shapes and the modal damping is demonstrated on a simulated mass-spring-damper system. Two different distributions of masses are considered in order to confront the CPOD analysis to the intrinsic limitation of POD, i.e. that the mode shapes are identified exactly only if the mass matrix is proportional to the identity matrix. It is shown that the identification of the damping is still possible when the modes are not orthonormal. The robustness of the technique is demonstrated in the presence of noise in the responses of the system and through an experimental application with comparison with other identifications techniques. [less ▲]

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See detailDamping identification of linear dynamic systems using Common-base Proper Orthogonal Decomposition
Andrianne, Thomas ULg; Dimitriadis, Grigorios ULg

in Proceedings of ISMA2012 (2012, September 19)

This paper presents a novel identification technique of the modal damping of linear systems. It is based on the Proper Orthogonal Decomposition (POD) of the free response of the system and extended to the ... [more ▼]

This paper presents a novel identification technique of the modal damping of linear systems. It is based on the Proper Orthogonal Decomposition (POD) of the free response of the system and extended to the Common-base POD (CPOD) approach. Different initial conditions are applied to the system and the corresponding free responses are considered simultaneously. The CPOD technique leads to a unique vector basis which is likely to contain more information about the dynamics of the system than a vector basis obtained by the classic POD technique, based on one set of initial conditions only. The ability of the technique to estimate the modal damping is demonstrated on a simulated mass-spring-damper system and an experimental system. Good agreement is shown between the damping estimates of the CPOD technique and the ones of the LSCF technique. The advantage and limitations of the present technique are discussed. [less ▲]

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See detailDamping material characterization and modeling: an industrial case-study
Poncelet, Fabien ULg; Bernay, Bruno; Kerschen, Gaëtan ULg et al

in International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE 2009), San Diego, 2009 (2009, August)

Turbojet engines contain potential nonlinearity sources such as geometric nonlinearities due to the slenderness and the length of modern blades, contacts between the blades and the shrouds, friction in ... [more ▼]

Turbojet engines contain potential nonlinearity sources such as geometric nonlinearities due to the slenderness and the length of modern blades, contacts between the blades and the shrouds, friction in the connections, and material nonlinearities. This paper focuses on the damping material which can be found in some stator stages of low-pressure compression parts. This material makes the shroud and all the blades of the stage interdependent, providing damping and fluid vein airtightness. The objective is to propose a characterization and a numerical modeling methodology that could easily be integrated within an industrial process. Nonlinearity characterization tests, based on the Restoring Force Surface method, are presented as well as viscoelastic characterization. Finally the proposed viscoelastic modeling, based on the Modal Strain Energy method, is validated against experimental data. [less ▲]

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See detailDamping rates of hard momentum particles in a cold ultrarelativistic plasma
Vanderheyden, Benoît ULg; Ollitrault, J. Y.

in Physical Review. D : Particles and Fields (1997), 56(8), 5108-5122

We compute the damping rates of one-particle excitations in a cold ultrarelativistic plasma to leading order in the coupling constant e for three types of interaction: Yukawa coupling to a massless scalar ... [more ▼]

We compute the damping rates of one-particle excitations in a cold ultrarelativistic plasma to leading order in the coupling constant e for three types of interaction: Yukawa coupling to a massless scalar boson, QED, and QCD. Damping rates of charged particles in QED and QCD are of order e(3) mu, while the damping rates of other particles are of order e(4) mu or e(4) mu log(1/e). We find that the damping rate of an electron or of a quark is constant far from the Fermi surface, and decreases linearly with the excitation energy close to the Fermi surface. This unusual behavior is attributed to the long-range magnetic interactions. [less ▲]

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See detailDamping rates of solar-like oscillations across the HR diagram. Theoretical calculations confronted to CoRoT and Kepler observations
Belkacem, K.; Dupret, Marc-Antoine ULg; Baudin, F. et al

in Astronomy and Astrophysics (2012), 540

The space-borne missions CoRoT and Kepler are providing a rich harvest of high-quality constraints on solar-like pulsators. Among the seismic parameters, mode damping rates remains poorly understood and ... [more ▼]

The space-borne missions CoRoT and Kepler are providing a rich harvest of high-quality constraints on solar-like pulsators. Among the seismic parameters, mode damping rates remains poorly understood and are thus barely used to infer the physical properties of stars. Nevertheless, thanks to the CoRoT and Kepler spacecrafts it is now possible to measure damping rates for hundreds of main-sequence and thousands of red-giant stars with unprecedented precision. By using a non-adiabatic pulsation code including a time-dependent convection treatment, we compute damping rates for stellar models that are representative of solar-like pulsators from the main-sequence to the red-giant phase. This allows us to reproduce the observations of both CoRoT and Kepler, which validates our modeling of mode damping rates and thus the underlying physical mechanisms included in the modeling. By considering the perturbations of turbulent pressure and entropy (including the perturbation of the dissipation rate of turbulent energy into heat) by the oscillation in our computation, we succeed in reproducing the observed relation between damping rates and effective temperature. Moreover, we discuss the physical reasons for mode damping rates to scale with effective temperature, as observationally exhibited. Finally, this opens the way for the use of mode damping rates to probe turbulent convection in solar-like stars. [less ▲]

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See detailDancing droplets onto liquid surfaces
Vandewalle, Nicolas ULg; Terwagne, Denis ULg; Mulleners, K. et al

Poster (2006, March)

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See detailDancing droplets onto liquid surfaces
Vandewalle, Nicolas ULg; Terwagne, Denis ULg; mulleners, karin et al

in Physics of Fluids (2006), 18

Detailed reference viewed: 38 (8 ULg)
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See detailDandruff-associated smouldering alopecia: a chronobiological assessment over 5 years.
Pierard, Claudine ULg; Xhauflaire, Emmanuelle ULg; Loussouarn, G. et al

in Clinical & Experimental Dermatology (2006), 31(1), 23-6

BACKGROUND: In some individuals, dandruff may be recurrent and even chronic. This represents a difficult-to-treat condition. Excessive hair shedding and diffuse alopecia may develop. OBJECTIVES: To ... [more ▼]

BACKGROUND: In some individuals, dandruff may be recurrent and even chronic. This represents a difficult-to-treat condition. Excessive hair shedding and diffuse alopecia may develop. OBJECTIVES: To evaluate the chronobiological aspects of dandruff, hair shedding and alopecia. METHODS: This study was performed in eight men suffering from such a scalp condition. They were examined 40 times at regular intervals for five consecutive years. Hair-density assessments and trichograms were performed at least twice per trimester on the parietal region of the scalp, corresponding to an area where dandruff was present. RESULTS: A positive correlation was found between the percentage of telogen hairs and dandruff severity as assessed by the squamometry index. Bimodal yearly biorhythms were found for dandruff severity, telogen counts and hair loss between two consecutive visits. The chronobiological fluctuations were prominent in some study participants, but remained inconspicuous in others. The biorhythms were almost synchronized in all participants, showing variations over the year. CONCLUSIONS: The biorhythms on the hair cycle in dandruff are not fundamentally different from those previously reported in subjects without dandruff. The periodicity may be an intrinsic feature of human skin. [less ▲]

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See detailLe danger d'utilisation des cocktails hormonaux
Beckers, Albert ULg

Scientific conference (2001, February 01)

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See detailLe dangereux mythe de la courbe de Gauss
de Landsheere, Gilbert ULg

in Doceo (1971), 21(170), 24-28

Detailed reference viewed: 58 (0 ULg)
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See detailLes dangers de l'allocation provisionnelle
Jacobs, Ann ULg

in Jurisprudence de Liège (1986)

Detailed reference viewed: 37 (0 ULg)
See detailDangers des substances anabolisantes en engraissement
Renaville, Robert ULg

in Les Elevages belges (1986), 8

Detailed reference viewed: 17 (0 ULg)