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See detailL'impiété dans les rapports sociaux en Grèce antique : le cas des étrangers
Delli Pizzi, Aurian ULg

Scientific conference (2014, March 18)

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See detailDeuxième mission de terrain dans la reserve de Yangambi
de Haulleville, Thalès ULg; Bogaert, Jan ULg; Beeckman, Hans

Scientific conference (2014, March 18)

Presentation of Thales de Haulleville's planned fieldwork during his second field mission.

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See detailInfluence of dipole-dipole interactions decoherence-free states
Damanet, François ULg; Martin, John ULg

Poster (2014, March 18)

Decoherence, known as the consequence of the coupling of any quan- tum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quan ... [more ▼]

Decoherence, known as the consequence of the coupling of any quan- tum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quan- tum computers [1]. Decoherence-Free States (DFS) are considered as a possible solution to this problem. A set of trapped cold atoms placed in a DFS state will be immune against decoherence due to sponta- neous emission. However, because of dipole-dipole interactions between atoms, induced dephasing effects are likely to destroy the coherence and drive the system out of its DFS [1-2]. In this work, we study nu- merically the dynamics of a set of two-level atoms initially in a DFS with respect to dissipative processes by solving the master equation in- cluding both dissipative dynamics and dipole dipole interactions. We focus our attention on the influence of dipolar coupling on the radiated energy rate and coherence of the system as in [3]. In particular, by av- eraging over many realizations of close randomly distributed atomic positions, we show the formation of a superradiant-like pulse and we study its properties as a function of the dipolar coupling strength. [1] D. A. Lidar & K. B. Whaley, Lectures Notes in Phys., Vol. 622, p83-120, Springer (2003). [2] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [3] W. Feng, Y. Li & S. -Y. Zhu, arXiv :1302.0957. (2013). [less ▲]

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See detailConclusion et mise en perspective des présentations et débats de la matinée
Halleux, Jean-Marie ULg

Conference given outside the academic context (2014)

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See detailPsychopathologie et philosophie du visage en prison
Englebert, Jérôme ULg

Scientific conference (2014, March 18)

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See detailDistributed control of electromechanical oscillations in very large-scale electric power systems
Wang, Da ULg

Doctoral thesis (2014)

Electromechanical oscillations threaten the secure operation of power systems and if not controlled efficiently can lead to generator outages, line tripping and even large-scale blackouts. Different ... [more ▼]

Electromechanical oscillations threaten the secure operation of power systems and if not controlled efficiently can lead to generator outages, line tripping and even large-scale blackouts. Different damping devices, like Power System Stabilizers (PSSs), Thyristor Controlled Series Compensators (TCSCs), and so on, are installed to damp these oscillations. This thesis proposes a trajectory-based supplementary control to improve damping effects of existing controllers, which treats damping control as a multi-step optimization control problem with discrete dynamics and costs. At each control time, it collects current system states, solves the optimal control problem and superimposes the calculated supplementary inputs on the outputs of existing damping controllers, in order to enhance the damping. These supplementary signals are continuously updated, which allows to adaptively adjust and coordinate a subset of existing damping controllers, and eventually all of them. Two kinds of methods, Model Predictive Control (MPC) and Reinforcement Learning (RL), are used to embody the proposed supplementary damping control. Firstly, a fully centralized MPC scheme is designed based on a linearized, discrete, complete state space model. Its performances are evaluated both in ideal conditions and considering realistic state estimation errors, and computation and communication delays. The effects of the number and type of available damping controllers are also studied. This scheme is further extended into a distributed scheme with the aim of making it more viable for very large-scale or multi-area systems. Different ways of decoupling and coordinating between subsystems are analyzed. Finally, a robust hierarchical multi-area MPC scheme is proposed, introducing a second layer of MPC based controllers at the level of individual power plants and transmission lines. Secondly, a tree-based batch mode RL algorithm is applied to carry on the proposed supplementary damping control. Using a set of dynamic and reward four-tuples, it constructs an approximation of the optimal $Q$-function over a given temporal horizon. The actions greediest with respect to the $Q$-function are applied as supplementary signals to existing damping controllers. The scheme is firstly tested on a single generator, and then on multiple generators. Different reward signals and damping levels are also considered. Finally, the combined control effects of MPC and RL are investigated. [less ▲]

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See detailCFD-based Compartment model for description of mixing in bioreactors
Delafosse, Angélique ULg; Calvo, Sébastien ULg; Collignon, Marie-Laure ULg et al

in Chemical Engineering Science (2014), 106

In most bioprocesses, it is fundamental to accurately predict the hydrodynamics behavior of bioreactors of different size and its interaction with the biological reaction. Computational Fluid Dynamics can ... [more ▼]

In most bioprocesses, it is fundamental to accurately predict the hydrodynamics behavior of bioreactors of different size and its interaction with the biological reaction. Computational Fluid Dynamics can provide detailed modeling about hydrodynamics and mixing. However, it is computationally intensive, especially when reactions are taken into account. Another way to predict hydrodynamics is the use of “Compartment” or “Network-of-zones” model which are much less demanding in computation time than CFD. However, compartments and fluxes between them are often defined by considering global quantities not representative of the flow complexity. To overcome the limitations of these two methods, a solution is to combine compartment modeling and CFD simulations. The aim of this study is to propose a compartment model where the flow rates between two adjacent compartments are easily computed from the velocity fields obtained by CFD. The mixing evolution predicted by the CFD-based compartment model have been then compared with mixing experiment results. Unlike a CFD mixing simulation and a classical compartment model, the CFD-based compartment model proposed in this work reproduces with a good accuracy the spatial distribution of concentrations during the mixing process and this, without any adjustable parameters. [less ▲]

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See detailQue devient l'Empire quand apparaît l'Etat? L'idéal universaliste à l'épreuve de la modernité
Delfosse, Annick ULg

Conference given outside the academic context (2014)

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See detailL'éjaculation précoce et son traitement : Le critère d’une minute maximum de pénétration en question
Kempeneers, Philippe ULg

Scientific conference (2014, March 15)

Il existe actuellement une tendance à réserver le diagnostic de trouble de l‘éjaculation précoce (EP) aux seuls cas caractérisés par des durées de pénétration inférieures ou égales à une minute environ ... [more ▼]

Il existe actuellement une tendance à réserver le diagnostic de trouble de l‘éjaculation précoce (EP) aux seuls cas caractérisés par des durées de pénétration inférieures ou égales à une minute environ. L’idée sous-jacente est que ces situations relèveraient d’une étiologie essentiellement bio-constitutionnelle et qu’un traitement pharmacologique au long cours constituerait l’unique option thérapeutique valable. À l’examen de la littérature cependant, les évidences scientifiques invoquées en soutien de cette proposition apparaissent assez faibles. Bon nombre de personnes souffrant d’éjaculer trop rapidement présentent en effet des durées de pénétration supérieures à une minute, et il semble que les formes sévères d’EP puissent aussi répondre favorablement à des traitements psycho-sexologiques. En outre, s’il s’avère certain que des variables biologiques influencent la latence éjaculatoire, rien ne permet cependant de prétendre qu’elles jouent, dans les formes sévères d’EP, un rôle exclusif de facteurs étiologiques psychosociaux. Il apparaît ainsi « prématuré » de fonder le diagnostic d’EP sur une durée de pénétration d’une minute maximum, ce critère détermine plutôt un gradient de sévérité du trouble. Considérant que, en matière de durée de pénétration, les critères d’aspiration se situent souvent au delà des normes biologiques, il semble délicat de soutenir que seules les formes d’EP les plus sévères auraient une origine bio-constitutionnelle. Dans tous les cas au demeurant, la constitution s’avère relativement plastique, sensible aux apprentissages à visée adaptative. Ceux-ci sont sans doute plus difficiles à réaliser par les porteurs d’une forme sévère du trouble, mais pas impossibles. La question de l’indication d’un traitement pharmacologique ou psycho-sexologique gagnerait à se dégager d’un simple critère de latence éjaculatoire. [less ▲]

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See detailPRP and tendinopathy, from in vitro to clinical trials
Kaux, Jean-François ULg

Conference (2014, March 15)

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Peer Reviewed
See detailSystematic optimization of subcritical and transcritical organic Rankine cycles (ORCs) constrained by technical parameters in multiple applications
Maraver, Daniel; Royo, Javier; Lemort, Vincent ULg et al

in Applied Energy (2014), 117

The present work is focused on the thermodynamic optimization of organic Rankine cycles (ORCs) for power generation and CHP from different average heat source profiles (waste heat recovery, thermal oil ... [more ▼]

The present work is focused on the thermodynamic optimization of organic Rankine cycles (ORCs) for power generation and CHP from different average heat source profiles (waste heat recovery, thermal oil for cogeneration and geothermal). The general goal is to provide optimization guidelines for a wide range of operating conditions, for subcritical and transcritical, regenerative and non-regenerative cycles. A parameter assessment of the main equipment in the cycle (expander, heat exchangers and feed pump) was also carried out. An optimization model of the ORC (available as an electronic annex) is proposed to predict the best cycle performance (subcritical or transcritical), in terms of its exergy efficiency, with different working fluids. The working fluids considered are those most commonly used in commercial ORC units (R134a, R245fa, Solkatherm, n-Pentane, Octamethyltrisiloxane and Toluene). The optimal working fluid and operating conditions from a purely thermodynamic approach are limited by the technological constraints of the expander, the heat exchangers and the feed pump. Hence, a complementary assessment of both approaches is more adequate to obtain some preliminary design guidelines for ORC units. [less ▲]

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See detailJeu vidéo et types de récits interactifs
Hurel, Pierre-Yves ULg

Conference given outside the academic context (2014)

https://www.youtube.com/watch?v=IKp8M8pV0Lc

Detailed reference viewed: 9 (0 ULg)
See detailL'importance du corps dans le développement socio-affectif et cognitif dans les classes de maternelle
Degraux, Christine ULg

Conference given outside the academic context (2014)

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See detailLa carte blanche : Enjeux de la Politique agricole commune en Wallonie : une volonté de découpler nature et agriculture ?
Jacquemart, Anne-Laure; Dendoncker, Nicolas; Dufrêne, Marc ULg et al

Article for general public (2014)

Detailed reference viewed: 12 (1 ULg)
See detailEpidemiology and genetics of pituitary adenomas
Beckers, Albert ULg

Scientific conference (2014, March 14)

Detailed reference viewed: 6 (0 ULg)
See detailRetour au travail après une absence de longue durée
Mairiaux, Philippe ULg

Conference (2014, March 14)

Detailed reference viewed: 9 (0 ULg)