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See detailCalibration of force actuators on an adaptive secondary prototype
Ricci, Davide ULg; Riccardi, Armando; Zanotti, Daniela

in Applied Optics (2008), 47

In the context of the Large Binocular Telescope project, we present the results of force actuator calibrations performed on an adaptive secondary prototype called P45, a thin deformable glass with magnets ... [more ▼]

In the context of the Large Binocular Telescope project, we present the results of force actuator calibrations performed on an adaptive secondary prototype called P45, a thin deformable glass with magnets glued onto its back. Electromagnetic actuators, controlled in a closed loop with a system of internal metrology based on capacitive sensors, continuously deform its shape to correct the distortions of the wavefront. Calibrations of the force actuators are needed because of the differences between driven forces and measured forces. We describe the calibration procedures and the results, obtained with errors of less than 1.5%. [less ▲]

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See detailGround-based observations of the beta Cephei CoRoT main target HD 180642
Briquet, Maryline ULg; Uytterhoeven, K.; Aerts, C. et al

in Communications in Asteroseismology (2008)

We present the preliminary results of a detailed study of ground-based photometric and spectroscopic observations dedicated to the β Cephei CoRoT main target HD 180642. Besides the non-linear dominant ... [more ▼]

We present the preliminary results of a detailed study of ground-based photometric and spectroscopic observations dedicated to the β Cephei CoRoT main target HD 180642. Besides the non-linear dominant radial mode several low-amplitude modes are detected in both kinds of datasets. Our aim is to derive the wavenumbers (ℓ,m) of these modes, as additional constraints to the CoRoT pulsation frequencies, for forthcoming asteroseismic modelling of the star. [less ▲]

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See detailOn the Sets of Real Numbers Recognized by Finite Automata in Multiple Bases
Boigelot, Bernard ULg; Brusten, Julien ULg; Bruyère, Véronique

in Lecture Notes in Computer Science (2008, July), 5126

This paper studies the expressive power of finite automata recognizing sets of real numbers encoded in positional notation. We consider Muller automata as well as the restricted class of weak ... [more ▼]

This paper studies the expressive power of finite automata recognizing sets of real numbers encoded in positional notation. We consider Muller automata as well as the restricted class of weak deterministic automata, used as symbolic set representations in actual applications. In previous work, it has been established that the sets of numbers that are recognizable by weak deterministic automata in two bases that do not share the same set of prime factors are exactly those that are definable in the first order additive theory of real and integer numbers (R, Z, +, <). This result extends Cobham's theorem, which characterizes the sets of integer numbers that are recognizable by finite automata in multiple bases. In this paper, we first generalize this result to multiplicatively independent bases, which brings it closer to the original statement of Cobham's theorem. Then, we study the sets of reals recognizable by Muller automata in two bases. We show with a counterexample that, in this setting, Cobham's theorem does not generalize to multiplicatively independent bases. Finally, we prove that the sets of reals that are recognizable by Muller automata in two bases that do not share the same set of prime factors are exactly those definable in (R, Z, +, <). These sets are thus also recognizable by weak deterministic automata. This result leads to a precise characterization of the sets of real numbers that are recognizable in multiple bases, and provides a theoretical justification to the use of weak automata as symbolic representations of sets. [less ▲]

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See detailBuilding and HVAC system simulation with the help of an engineering equation solver
Bertagnolio, Stéphane ULg; Masy, Gabrielle; Andre, Philippe ULg et al

in Proceedings of the 3rd National conference of the IBPSA-USA, Berkeley, CA (2008, July)

A simplified Building-HVAC system model is presented here. It includes simplified models of building zone and of HVAC equipment. The simplified building zone model is based on a R and C network, whose ... [more ▼]

A simplified Building-HVAC system model is presented here. It includes simplified models of building zone and of HVAC equipment. The simplified building zone model is based on a R and C network, whose parameters are adjusted trough a frequency characteristic analysis. The implementation of the classical phenomena taking place in building dynamics is discussed. The simplified building model is compared with more detailed models, using the BESTEST procedure. The application of the presented model to the audit of commercial buildings is also discussed. [less ▲]

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See detailLa prise en compte de la dimension urbaine dans les Programmes Opérationnels Feder 2007-2013
Chevau, Thomas; Harou, Raphaëlle; Teller, Jacques ULg

Report (2008)

Le groupe « expertise ville » a été saisi de la demande suivante par l’administration : présenter et analyser la dimension urbaine dans les interventions du FEDER 2007-2013 dans le cadre des Programmes ... [more ▼]

Le groupe « expertise ville » a été saisi de la demande suivante par l’administration : présenter et analyser la dimension urbaine dans les interventions du FEDER 2007-2013 dans le cadre des Programmes Opérationnels (POs) wallons « Convergence » et « Compétitivité régionale et emploi ». [less ▲]

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See detailAnalyse croisée de la politique de la ville en France, en Angleterre et en Flandre
Chevau, Thomas; Cremasco, Veronica; Harou, Raphaëlle et al

Report (2008)

Partant du constat que les grandes villes cumulaient une série de difficultés, la France, la Flandre et l’Angleterre ont mis en place, à partir des années 1980, des dispositifs de rénovation et de ... [more ▼]

Partant du constat que les grandes villes cumulaient une série de difficultés, la France, la Flandre et l’Angleterre ont mis en place, à partir des années 1980, des dispositifs de rénovation et de développement social et économique centrés, dans un premier temps, sur des quartiers dits « en difficulté » pour s’étendre ensuite à des unités urbaines plus vastes, des villes voire des agglomérations urbaines entières. Ces initiatives, que nous avons regroupées sous le vocable français de « politique de la ville », bien qu’il n’ait pas de correspondance directe en Angleterre, se sont développées selon des approches et des modalités assez différentes dans ces trois régions. Ainsi, alors que l’apparition de la politique de la ville en France est d’abord liée à la crise des banlieues et à la réponse que souhaitait lui donner le gouvernement socialiste de l’époque, en Angleterre elle va plutôt s’inscrire dans une approche néo-libérale des questions urbaines, approche qui privilégie le recours au marché pour redynamiser le tissu social et économique des zones en difficulté. En Flandre la mise en place d’une véritable politique de la ville est plus progressive et son développement actuel nous paraît lié à une volonté d’émancipation des autorités flamandes vis-à-vis du pouvoir fédéral. Au delà de différences liées à leur origine, le rapport s’attache à retracer la genèse de ces politiques et à identifier leurs principales orientations actuelles. Nous avons également cherché à cadrer les structures institutionnelles et les volants budgétaires sur lesquelles elles s’appuient, sachant que, dans ce domaine également, il existe de grandes « lignes de partage » entre les trois régions étudiées. Dans l’optique d’une recherche opérationnelle, nous avons cherché à extraire de ce rapport les grandes lignes de partage entre ces différentes politiques, ainsi qu’entre différentes « générations » de politiques de la ville, sachant que l’on observe également des phénomènes de convergence entre les différents modèles proposés. Ces lignes de partage sont aux nombre de trois : les options et priorités, les leviers d’action et la structure institutionnelle. [less ▲]

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See detailNovel Higgs decay signals in R-parity violating models
Aristizabal Sierra, Diego ULg; Porod, W.; Restrepo, D. et al

in Physical Review. D : Particles and Fields (2008), 78

In supersymmetric models the lightest Higgs boson may decay with a sizable branching ratio into a pair of light neutralinos. We analyze such decays within the context of the minimal supersymmetric ... [more ▼]

In supersymmetric models the lightest Higgs boson may decay with a sizable branching ratio into a pair of light neutralinos. We analyze such decays within the context of the minimal supersymmetric standard model with R-parity violation, where the neutralino itself is unstable and decays into Standard Model fermions. We show that the R-parity violating couplings induce novel Higgs decay signals that might facilitate the discovery of the Higgs boson at colliders. At the LHC, the Higgs may be observed, for instance, through its decay -via two neutralinos- into final states containing missing energy and isolated charged leptons such as l±l∓,l±l±,3l, and 4l. Another promising possibility is the search for the displaced vertices associated with the neutralino decay. We also point out that Higgs searches at the LHC might additionally provide the first evidence of R-parity violation. [less ▲]

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See detail"Diabolo-Manques", histoire d'une évaluation
Grignard, Sophie ULg; Vandoorne, Chantal ULg

in Education Santé (2008), (236), 2-3

Cet article présente les grandes lignes d’une brochure, coéditée par l’APES-ULg et par la Maison du Social de la Province de Liège, et intitulée «Diabolo-Manques - Une exploration à la découverte de soi ... [more ▼]

Cet article présente les grandes lignes d’une brochure, coéditée par l’APES-ULg et par la Maison du Social de la Province de Liège, et intitulée «Diabolo-Manques - Une exploration à la découverte de soi - L'évaluation d'un programme de prévention des assuétudes en Province de Liège». Cette brochure d’une vingtaine de pages décrit de façon synthétique et intégrée les différentes phases d’évaluation de ce programme ainsi que leurs résultats. [less ▲]

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See detailImprovement in Thixoforging of 7075 Aluminium Alloys at High Solid Fraction
Vaneetveld, Grégory ULg; Rassili, Ahmed ULg; Pierret, Jean-Christophe ULg et al

in Solid State Phenomena (2008), 141-143

Thixoforging is a type of semi-solid metal processing at high solid fraction (0.5<1). 7075 aluminium alloys have been used as a feedstock for thixoforging in order to investigate thixoformability of a ... [more ▼]

Thixoforging is a type of semi-solid metal processing at high solid fraction (0.5<1). 7075 aluminium alloys have been used as a feedstock for thixoforging in order to investigate thixoformability of a high performance aluminium alloy at high solid fraction. Higher solid fraction of 7075 alloy is less sensitive to temperature, avoids metal splash at high speed and allows laminar flow at high speed. Hot tool combined with lubricant tool coating are used to slow down the solidification rate of the high solid fraction metal by decreasing thermal exchanges with the tool. Improved thermal and forming parameters [1-2] will be applied to produce an automotive component by thixoforging and mechanical properties have been measured from tensile samples. High mechanical properties are obtained after T6 thermal treatment. [less ▲]

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See detailDetecting with PMUs the onset of voltage instability caused by a large disturbance
Glavic, Mevludin; Van Cutsem, Thierry ULg

(2008, July)

This paper deals with long-term voltage instability triggered by the outage of transmission or generation equipments. It is shown how the onset of voltage instability could be detected in real-time from ... [more ▼]

This paper deals with long-term voltage instability triggered by the outage of transmission or generation equipments. It is shown how the onset of voltage instability could be detected in real-time from post-disturbance bus voltages provided by Phasor Measurement Units (PMUs), assuming observability of the whole region prone to voltage instability. An extended set of equilibrium equations is fitted to the measurements and the change in sign of sensitivities is onitored. The latter are easily computed even for a large system. The important effects of overexcitation limiters and load tap changers are taken into account. The approach is illustrated on a 52-bus 20-machine system, where PMU outputs are simulated from detailed time simulation. [less ▲]

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See detailGlobal synchronization on the circle
Sarlette, Alain ULg; Tuna, Sezai Emre; Blondel, Vincent et al

in Proceedings of the 17th IFAC World Congress (2008, July)

The convexity arguments used in the consensus literature to prove synchronization in vector spaces can be applied to the circle only when all agents are initially located on a semicircle. Existing ... [more ▼]

The convexity arguments used in the consensus literature to prove synchronization in vector spaces can be applied to the circle only when all agents are initially located on a semicircle. Existing strategies for (almost-)global synchronization on the circle are either restricted to specific interconnection topologies or use auxiliary variables. The present paper first illustrates this problem by showing that weighted, directed interconnection topologies can be designed to make any reasonably chosen configuration of the agents on the circle a stable equilibrium of a basic continuous-time consensus algorithm. Then it proposes a so-called “gossip algorithm”, which achieves global asymptotic synchronization on the circle with probability 1 for a large class of interconnections, without using auxiliary variables, thanks to the introduction of randomness in the system. [less ▲]

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See detailCurrent Trends in the Research on Physical Education Teacher Education (PETE)
Cloes, Marc ULg

Conference (2008, July)

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See detailEffects of small-scale atmospheric activity on precise positioning
Wautelet, Gilles ULg; Lejeune, Sandrine; Stankov, Stanimir et al

Report (2008)

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See detailMoins, mieux et autrement : Maintenant !
Ozer, Pierre ULg; Perrin, Dominique ULg

Article for general public (2008)

Veiller à la composition de notre assiette et être attentif à nos modes de déplacements sont deux éléments clefs qui font partie des multiples petits actes citoyens que nous pouvons poser pour participer ... [more ▼]

Veiller à la composition de notre assiette et être attentif à nos modes de déplacements sont deux éléments clefs qui font partie des multiples petits actes citoyens que nous pouvons poser pour participer à l’effort mondial de lutte contre le réchauffement climatique. Refuser de s’adapter ne reflète que notre opiniâtreté à vouloir nous emmitoufler dans un mode de vie qui n’est plus viable et notre incapacité à se détourner d’une société d’auto-consumation. [...] [less ▲]

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See detailMerging academic libraries: An opportunity for a face-lift?
Durieux, Nancy ULg; Vandenput, Sandrina ULg; Brouwir, Christine ULg et al

Conference (2008, June 26)

Although the decision to merge libraries generates stress, it is also a great opportunity to start a global reflection on the functioning of libraries. In 2003, the University of Liège decided to create a ... [more ▼]

Although the decision to merge libraries generates stress, it is also a great opportunity to start a global reflection on the functioning of libraries. In 2003, the University of Liège decided to create a new physical and functional structure by combining the previously independent libraries of Medicine, Veterinary Medicine, Botany, Zoology, Psychology and Educational Sciences. The initial phase included a plan to remove the collections and standardise the academic teaching of IT literacy in the various disciplines. We now want to question our missions and evaluate our present working procedures in order to optimise our services, eventually develop new ones, and make them visible through a new website or any other types of support. The different populations of users need to be clearly identified, evaluated and anticipated. Staff competences must be evaluated to guarantee that users' expectations are met, and possibly to envisage any new services that may need to be created. In addition, staff competences must be improved through adapted education and tailored professional training. At the same time, the library involvement in academic teaching deserves to be properly highlighted. We are aware that there is not anything new in such an approach, but the pieces of evidence are scattered, outdated or not adapted to our present situation. As a consequence, we propose an overview of the literature concerning the marketing of academic libraries, conducted according to the principles of Evidence-Based Library and Information Practice. We shall select the most important publications providing strong theoretical support, and we shall collect existing tools, evaluation grids and procedure rules that might be useful during any step of the project. We shall organise them into a structured and pragmatic working strategy that could be used by any library interested in a marketing approach. It should integrate the different topics previously mentioned such as the library’s missions, the evaluation and optimisation of services, as well as the visibility of the teaching activities and the professional education programmes developed by academic libraries. [less ▲]

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See detailFair Trade Organisations in Europe: A Significant Field of Social Enterprise?
Huybrechts, Benjamin ULg

Conference (2008, June 26)

With the help of examples of FTOs in Belgium, France, Italy and the UK, we have applied some of the features of SE approaches to the context of FT. It appears that FTOs are particularly significant ... [more ▼]

With the help of examples of FTOs in Belgium, France, Italy and the UK, we have applied some of the features of SE approaches to the context of FT. It appears that FTOs are particularly significant examples of SEs, combining in different ways economic, social and sometimes political dimensions. From more NGO-like to more business-like configurations, all FTOs of our sample seem to respect the key features of SEs, under which the primacy of 23 the social mission, the limited (if any) profit distribution, the focus on innovation and at least some degree of self-financing. Nevertheless, there is some heterogeneity in terms of FTOs’ goals and activities. While all FTOs seem to combine, at least, economic and social dimensions – although at varying degrees and forms –, the political dimension is not present in the same way for all FTOs. Pioneer FTOs generally conduct education and advocacy activities in a developed and explicit way. Newcomer FTOs, however, have heterogeneous profiles in terms of political involvement, as the positioning seems to depend much on the entrepreneur’s choices. In terms of governance, practices are also very diverse in terms of leaders’ profiles, legal forms and stakeholders’ involvement in the decision-making structures. Some FTOs are quasi-individual ventures and are thus close to some American approaches of SE. Other FTOs are much more multi-stakeholder and fit better in the EMES conceptualisation of SE. The governance structure also seems to reflect to a certain extent the positioning of the FTO towards the different dimensions of FT. FTOs led by activists and having volunteers or partner NGOs on their Board seem to have a stronger focus on non-economic (social and political) goals. In the other sense, very economic-oriented FTOs are often run by managers with a business background and governed by their manager and/or their shareholders. As a conclusion, this article has tried to provide some theoretical and empirical support to the implicit link that has been established, both in the academic world and in the field practice, between FT and SE. The diversity of the FT sector echoes the rich diversity of SEs’ practices and conceptualisations. In such sense, considering FTOs as SEs is probably made easier because of the wide and flexible theoretical framework of SE – few authors claiming to have a “definition” of SE. If more restricted conceptions of SE were to emerge – e.g., the limitation of SE to formal Third Sector legal forms, or to 100% market financing –, then part of the FTOs would be excluded from the SE area. In such sense, FT appears as an important laboratory the evolutions of which can feed the theoretical construction of SE. [less ▲]

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