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See detailSlachtoffer
Dubois, Christophe ULg; Martin, Daniel

in Hendrick, Aude; Musin, Aude; Rousseaux, Xavier (Eds.) et al Het verhaal van justitie (2017)

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See detailHerstelgerichte Justitie
Dubois, Christophe ULg

in Hendrick, Aude; Musin, Aude; Rousseaux, Xavier (Eds.) et al Het verhaal van justitie (2017)

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See detailNonlinear Robust Control for Satellite Formation Flying via Adaptive Second-Order Sliding Modes
Cho, Hancheol ULg; Kerschen, Gaëtan ULg

in 27th AAS/AIAA Space Flight Mechanics Meeting, San Antonio 5-9 February 2017 (2017, February)

This paper presents a robust adaptive control methodology based on the concept of second-order sliding modes for satellite formation control in the presence of unknown, but bounded uncertainties. By ... [more ▼]

This paper presents a robust adaptive control methodology based on the concept of second-order sliding modes for satellite formation control in the presence of unknown, but bounded uncertainties. By introducing two sliding variables to achieve the concept of second-order sliding modes, a robust controller is designed so that it forces the first sliding variable to converge to a desired error box in a finite time. Then, the second sliding variable is automatically bounded in a much smaller region by sliding mode control theory, thereby considerably improving the control accuracy. The proposed control scheme is of a smooth form and effectively alleviates chattering. An adaptive law that updates the control gain is also presented without a priori knowledge of the uncertainties. Numerical simulations, in which a desired formation configuration is required to be precisely maintained under uncertain mass and external disturbances, are carried out to validate the efficiency and the accuracy of the proposed robust adaptive control scheme developed herein. [less ▲]

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See detailLearning from blind tests: Determining the function of experimental grinding stones through use-wear and residue analysis
Hayes, Elspeth H.; Cnuts, Dries ULg; Lepers, Christian et al

in Journal of Archaeological Science: Reports (2017), 11

Abstract Blind tests provide an objective means to evaluate the accuracy of functional interpretations based on the presence of use-wear and residue traces on stone tools. Previous blind tests have ... [more ▼]

Abstract Blind tests provide an objective means to evaluate the accuracy of functional interpretations based on the presence of use-wear and residue traces on stone tools. Previous blind tests have highlighted interpretive errors commonly associated with use-wear and residue analyses leading to significant methodological developments in each of the respective fields. While a number of blind tests have been performed on flaked stone tools, only a single blind test has been published for use-wear on grinding tools. We present the results of a two-part blind test performed on 15 experimental grinding implements that were used in a controlled setting, designed to evaluate the relative importance of residue analysis for determining the worked material (1) when contextual information is available and (2) when contextual information is absent. We argue that use-wear and residue analyses are successful procedures to identify the use of grinding stones, and that residue analysis may be a particularly valuable means for determining the worked material on tools that have insufficient use-wear development. We suggest that residues should be sufficiently abundant to infer use, if we are to avoid the potential confusion caused by contamination. [less ▲]

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See detailThe importance of open data and software: Is energy research lagging behind?
Pfenninger, Stefan; DeCariolis, Joseph; Hirth, Lion et al

in Energy Policy (2017)

Energy policy often builds on insights gained from quantitative energy models and their underlying data. As climate change mitigation and economic concerns drive a sustained transformation of the energy ... [more ▼]

Energy policy often builds on insights gained from quantitative energy models and their underlying data. As climate change mitigation and economic concerns drive a sustained transformation of the energy sector, transparent and well-founded analyses are more important than ever. We assert that models and their associated data must be openly available to facilitate higher quality science, greater productivity through less duplicated effort, and a more effective science-policy boundary. There are also valid reasons why data and code are not open: ethical and security concerns, unwanted exposure, additional workload, and institutional or personal inertia. Overall, energy policy research ostensibly lags behind other fields in promoting more open and reproducible science. We take stock of the status quo and propose actionable steps forward for the energy research community to ensure that it can better engage with decision-makers and continues to deliver robust policy advice in a transparent and reproducible way. [less ▲]

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See detailInflences of biological findings in the field of architectural theory and formal developments in the french landscape of the 1960
Van Rooyen, Xavier ULg

Conference (2017, February)

In 1960, some architects questionned the « Charte d’Athènes » and its principles. They explored the language of architecture in some Congress and took the name of Team X. During their meeting they tried ... [more ▼]

In 1960, some architects questionned the « Charte d’Athènes » and its principles. They explored the language of architecture in some Congress and took the name of Team X. During their meeting they tried to take into account the potential of different finding in sciences. The architects of the Team X group who intervened in France where mostly influenced by structuralist apprach of Levi-Strauss an the biologist François Jacob. In his book la logique du vivant , Jacob introduced some concepts, some vocabulary words which inspired architects. These terms, this architectural grammar is : fabric, cells, DNA, 3d structure. Candilis-Wood-Josic were influenced by Jacob’s book and radio conference at that time and did some projects around theses formal analogies. In our point of view, like Jean Renaudie said, biology findings influenced his vision of the society and contributed to question architecture, its forms, its vocabulary. For us, biological analogies following Jean-Pierre Chupin decription, contributed mostly to the development of the neo avant-garde in the 1960’s in France and the different constructions we can see in the french landscape marked the architectural theory and is widely reused nowadays. Through these conference, we want to demonstrate that hypothesis trhough the work of l’Atelier de Montrouge in which Jean Renaudie worked. [less ▲]

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See detailResidential heat pump as flexible load for direct control service with parametrized duration and rebound effect
Georges, Emeline ULg; Cornélusse, Bertrand ULg; Ernst, Damien ULg et al

in Applied Energy (2017), 187

This paper addresses the problem of an aggregator controlling residential heat pumps to offer a direct control flexibility service. The service consists of a power modulation, upward or downward, that is ... [more ▼]

This paper addresses the problem of an aggregator controlling residential heat pumps to offer a direct control flexibility service. The service consists of a power modulation, upward or downward, that is activated at a given time period over a fixed number of periods. The service modulation is relative to an optimized baseline that minimizes the energy costs. The load modulation is directly followed by a constrained rebound effect, consisting of a delay time with no deviations from the baseline consumption and a payback time to return to the baseline state. The potential amount of modulation and the constrained rebound effect are computed by solving mixed integer linear problems. Within these problems, the thermal behavior of the building is modeled by an equivalent thermal network made of resistances and lumped capacitances. Simulations are performed for different sets of buildings typical of the Belgian residential building stock and are presented in terms of achievable modulation amplitude, deviations from the baseline and associated costs. A cluster of one hundred ideal buildings, corresponding to retrofitted freestanding houses, is then chosen to investigate the influence of each parameter defined within the service. Results show that with a set of one hundred heat pumps, a load aggregator could expect to harvest mean modulation amplitudes of up to 138 kW for an upward modulation and up to 51 kW for a downward modulation. The obtained values strongly depend on the proposed flexibility service. For example, they can decrease down to 2.6 kW and 0.4 kW, respectively, if no rebound effect is allowed. [less ▲]

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See detailNew data on the Mesozoic radiation of chelonioids
Scavezzoni, Isaure ULg; Fischer, Valentin ULg

Poster (2017, February)

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See detailMegaloolithid dinosaur eggs: scrambled parataxonomy and nesting strategies
Jentgen, Benjamin ULg; Stein, Koen; Fischer, Valentin ULg

Poster (2017, February)

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See detailLa notion d’attention virtuelle dans la philosophie médiévale
Dubouclez, Olivier ULg

Scientific conference (2017, February)

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See detailApproximate Bayes Optimal Policy Search using Neural Networks
Castronovo, Michaël ULg; François-Lavet, Vincent ULg; Fonteneau, Raphaël ULg et al

in Proceedings of the 9th International Conference on Agents and Artificial Intelligence (ICAART 2017) (2017, February)

Bayesian Reinforcement Learning (BRL) agents aim to maximise the expected collected rewards obtained when interacting with an unknown Markov Decision Process (MDP) while using some prior knowledge. State ... [more ▼]

Bayesian Reinforcement Learning (BRL) agents aim to maximise the expected collected rewards obtained when interacting with an unknown Markov Decision Process (MDP) while using some prior knowledge. State-of-the-art BRL agents rely on frequent updates of the belief on the MDP, as new observations of the environment are made. This offers theoretical guarantees to converge to an optimum, but is computationally intractable, even on small-scale problems. In this paper, we present a method that circumvents this issue by training a parametric policy able to recommend an action directly from raw observations. Artificial Neural Networks (ANNs) are used to represent this policy, and are trained on the trajectories sampled from the prior. The trained model is then used online, and is able to act on the real MDP at a very low computational cost. Our new algorithm shows strong empirical performance, on a wide range of test problems, and is robust to inaccuracies of the prior distribution. [less ▲]

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See detailPrendre soin du sauvage. Le devenir de la nature pour métier.
Denayer, Dorothée ULg

Conference (2017, February)

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See detailInduced Drag Calculations with the Unsteady Vortex Lattice Method for Cambered Wings
Lambert, Thomas ULg; Dimitriadis, Grigorios ULg

in AIAA Journal (2017), 55(2), 668-672

The Unsteady Vortex Lattice Method (UVLM) is an approach widely used to estimate the aerodynamic loads in unsteady subsonic flows. It is based on modeling the camber surface of a lifting body by means of ... [more ▼]

The Unsteady Vortex Lattice Method (UVLM) is an approach widely used to estimate the aerodynamic loads in unsteady subsonic flows. It is based on modeling the camber surface of a lifting body by means of bound vortex rings. Even though this method has been known and used for several decades, there is little discussion of the modeling of the leading-edge suction in the literature. To address this concern, Simpson et al. [1] presented a comparison of two different ways to model this effect for the case of uncambered airfoils and wings in harmonic pitch or plunge motions. They concluded that the Joukowski method converges significantly faster than the Katz technique as the number of chorwise panels is increased. The present paper is an extension of the study by Simpson et al. to cambered lifting surfaces. It shows that the presence of camber can change radically the convergence performance of the two methods. For cambered wings, the Katz approach converges significantly faster than the Joukowski technique. [less ▲]

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See detailChez Froidmont au Nord : lectures polyphoniques d’une quête identitaire
Baiwir, Esther ULg; Adams, Juliette; Demonchaux, Chloé et al

in Tortue verte. Revue en ligne des littératures francophones (2017)

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See detailVoyage[s] à travers le thymus
Geenen, Vincent ULg

in Science et Culture (2017), (465), 14-15

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See detailA propos de l'émotion créatrice : vie, institution et histoire dans Les Deux Sources
Caeymaex, Florence ULg

in François, A.; Riquier, C. (Eds.) Bergson, la morale, les émotions (Annales bergsoniennes VIII) (2017)

Ce chapitre montre la centralité de l'émotion dans la théorie sociale de Bergson, au-delà de sa théorie psychologique. L'émotion n'est cependant pas seulement un phénomène sociologique, logé au fond des ... [more ▼]

Ce chapitre montre la centralité de l'émotion dans la théorie sociale de Bergson, au-delà de sa théorie psychologique. L'émotion n'est cependant pas seulement un phénomène sociologique, logé au fond des institutions sociales et morales ; en associant l'émotion, non au registre de la sensibilité passive, mais à celui d'une sensibilité active et créatrice, il suggère qu'elle est à la source des grandes transformations morales sans lesquelles la vie humaine ne connaîtrait pas de temporalité historique à proprement parler. [less ▲]

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See detailArchitecture and deconstruction: translation as a matter of speculative theory
Bodart, Céline ULg

Conference (2017, February)

If this conference proposes to explore the singular and minor expressions of architectural theory, it could at first seem strange to propose here a paper about the so-called derridean years of ... [more ▼]

If this conference proposes to explore the singular and minor expressions of architectural theory, it could at first seem strange to propose here a paper about the so-called derridean years of architecture. Rather, the vast body of literature produced on this specific episode argues that the encounter of architectural discourses with derridean deconstruction played a major role into the implementation of "the gilded age of theory" (Mallgrave, Goodman, 2011). But such an "age" needs now to be redefined in regard with its own cultural boundaries. What the decon has produced in the Anglo-American field of architectural theory is not what the deconstruction has produced on the French-speaking part of the debate (following the argument of Cusset, 2005). In France, the question of the effects of the Derrida's philosophy on the contemporary architectural discourses and practices still causes a kind of discomfort. "As if" no one could face with what this disciplinary cross-over of the mid-eighties both has produced and has not succeeded in producing; "as if", failure or not, this experimental encounter could had been no effects or consequences on the theories and practices which succeeded it. From one cultural context to another, we have two different versions of a same history. Different but not unrelated. The proposition is here to invest the productive gap between these overlapped versions, in order to question their respective modes of construction but also to re-open their ways of being transmitted. From an original translation of Derrida's Haunt (Wigley, 1993) in French, I would present a methodological approach (Despret, 2001) which attempts to create the conditions of a renewed relation between different versions of what the deconstruction could have produced in architecture. The exercise of the translation is seen as a way to question the co-existence of these different possible versions; a way to slow down the multiple gestures which hastily sweep the hesitations in the shared course of their history. [less ▲]

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See detailTwo-domain and three-domain limit cycles in a typical aeroelastic system with freeplay in pitch
Verstraelen, Edouard ULg; Dimitriadis, Grigorios ULg; Dal Ben Rossetto, Gustavo et al

in Journal of Fluids & Structures (2017), 69

Freeplay is a significant source of nonlinearity in aeroelastic systems and is strictly regulated by airworthiness authorities. It splits the phase plane of such systems into three piecewise linear ... [more ▼]

Freeplay is a significant source of nonlinearity in aeroelastic systems and is strictly regulated by airworthiness authorities. It splits the phase plane of such systems into three piecewise linear subdomains. Depending on the location of the freeplay, limit cycle oscillations can result that span either two or three of these subdomains. The purpose of this work is to demonstrate the existence of two-domain cycles both theoretically and experimentally. A simple aeroelastic system with pitch, plunge and control deflection degrees of freedom is investigated in the presence of freeplay in pitch. It is shown that two-domain and three-domain cycles can result from a grazing bifurcation and propagate in the decreasing airspeed direction. Close to the bifurcation, the two limit cycle branches interact with each other and aperiodic oscillations ensue. Equivalent linearization is used to derive the conditions of existence of each type of limit cycle and to predict their amplitudes and frequencies. Comparisons with measurements from wind tunnel experiments demonstrate that the theory describes these phenomena with accuracy. [less ▲]

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