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See detailPourquoi et comment structurer ses acquis en sciences à l'école primaire ?
Giot, Bernadette ULg; Quittre, Valérie ULg

in Site du Ministère de la Communauté française de Belgique (2006)

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See detailBiological Image Classification with Random Subwindows and Extra-Trees
Marée, Raphaël ULg; Geurts, Pierre ULg; Wehenkel, Louis ULg

Conference (2006)

We illustrate the potential of our image classification method on three datasets of images at different imaging modalities/scales, from subcellular locations up to human body regions. The method is based ... [more ▼]

We illustrate the potential of our image classification method on three datasets of images at different imaging modalities/scales, from subcellular locations up to human body regions. The method is based on random subwindows extraction and the combination of their classification using ensembles of extremely randomized decision trees. [less ▲]

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See detailFrom Expository Teaching to First e-Learning Course Production: Capture in a 17 Online Course Sample of a Pedagogical Pattern Facilitating Transition
Verpoorten, Dominique ULg; Poumay, Marianne ULg; Delcomminette, Séverine ULg et al

in Advanced Learning Technologies (2006)

This paper discusses an activity structure, RQAT, mined from a study of 17 on-line courses. It formats this structure as a pedagogical pattern and presents it as an abstraction to support staff ... [more ▼]

This paper discusses an activity structure, RQAT, mined from a study of 17 on-line courses. It formats this structure as a pedagogical pattern and presents it as an abstraction to support staff development, especially faculty willing to incorporate first online components to enhance face to face courses. [less ▲]

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See detailG-quadruplexes in telomeric repeats are conserved in a solvent-free environment
Baker, Erin Shammel; Bernstein, Summer L; Gabelica, Valérie ULg et al

in International Journal of Mass Spectrometry (2006), 253(3), 225-237

The structural properties of G-quadruplex forming sequences. such as the human telomeric repeat d(T(2)AG(3))(n), are of great interest due to their role in cancer and cellular aging. To determine if G ... [more ▼]

The structural properties of G-quadruplex forming sequences. such as the human telomeric repeat d(T(2)AG(3))(n), are of great interest due to their role in cancer and cellular aging. To determine if G-quadruplexes are present in a solvent-free environment. different lengths of the telomeric repeat d(T(2)AG(3))(n) (where n = 1, 2, 4 and 6) and dTG(4)T were investigated with mass specteometry, ion mobility and molecular dynamics calculations. Nano-ESI-MS illustrated quadruples stoichiometries compatible with G-quadruplex Structure.; for each sequence, with dT(2)AG(3) and dTG(4)T forming 4-strand complexes with two and three NH4+ adducts. d(T(2)AG(3))(2) a 2-strand complex. and d(T(2)AG(3))(4) and d(T(2)AG(3))(6) remaining single-stranded. Experimental cross sections were obtained for all species using ion mobility method.,. In all case.,. these could be quantitatively matched to model cross sections with specific strand orientations (parallel/antiparallel) and structures. For each species, the solvent-free structures agreed with the solution CD measurements, but the ion mobility/modeling procedure often gave Much more detailed structural information. (C) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailInfluence of the non-linearity of the aerodynamic coefficients on the skewness of the buffeting drag force
Denoël, Vincent ULg; Degée, Hervé ULg

in Wind and Structures (2006), 9(6), 457-471

This paper is devoted to the non linear quasi-steady aerodynamic loading. A linear approximation is often used to compute the response of structures to buffeting forces. Some researchers have however ... [more ▼]

This paper is devoted to the non linear quasi-steady aerodynamic loading. A linear approximation is often used to compute the response of structures to buffeting forces. Some researchers have however shown that it is possible to account for the non linearity of this loading. This non linearity can come (i) from the squared velocity or (ii) from the shape of the aerodynamic coefficients (as functions of the wind angle of attack). In this paper, it is shown that this second origin can have significant implications on the design of the structure, particularly when the non linearity of the aerodynamic coefficient is important or when the transverse turbulence is important. [less ▲]

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See detailPositive and negative ion mode ESI-MS and MS/MS for studying drug-DNA complexes
Rosu, Frédéric ULg; Pirotte, Sophie ULg; De Pauw, Edwin ULg et al

in International Journal of Mass Spectrometry (2006), 253(3), 156-171

We report systematic investigation of duplex DNA complexes with minor groove binders (Hoechsts 33258 and 33342, netropsin and DAPI) and intercalators (daunomycin, doxorubicin, actinomycin D, ethidium ... [more ▼]

We report systematic investigation of duplex DNA complexes with minor groove binders (Hoechsts 33258 and 33342, netropsin and DAPI) and intercalators (daunomycin, doxorubicin, actinomycin D, ethidium, cryptolepine, neocryptolepine, m-Amsacrine, proflavine, ellipticine and mitoxantrone) by ESI-MS and ESI-MS/MS in the negative ion mode and in the positive ion mode. The apparent solution phase equilibrium binding constants can be determined by measuring relative intensities in the ESI-MS spectrum. While negative ion mode gives reliable results, positive ion mode gives a systematic underestimation of the binding constants and even a complete suppression of the complexes for intercalators lacking functional groups capable of interacting in the grooves. In the second part of the paper we systematically compare MS/MS fragmentation channels and breakdown curves in the positive and the negative modes, and discuss the possible uses and caveats of MS/MS in drug-DNA complexes. In the negative mode, the drugs can be separated in three groups: (1) those that leave the complex with no net charge; (2) those that leave the complex with a negative charge; and (3) those that remain attached on the strands upon dissociation of the duplex due to their positive charge. In the positive ion mode, all complexes fragment via the loss of protonated drug. Information on the stabilization of the complex by drug-DNA noncovalent interactions can be obtained straightforwardly only in the case of neutral drug loss. In all other cases, proton affinity (in the positive ion mode), gas-phase basicity (in the negative ion mode) and coulombic repulsion are the major factors influencing the fragmentation channel and the dissociation kinetics. [less ▲]

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See detailAnti-American Sentiment and America’s Perceived Intent to Dominate: An 11-Nation Study
Glick, Peter; Fiske, Susan T; Abrams, Dominique et al

in Basic & Applied Social Psychology (2006), 28(4), 363-173

Perceptions of America as a powerful but malevolent nation decrease its security. On the basis of measures derived from the stereotype content model (SCM) and image theory (IT), 5,000 college students in ... [more ▼]

Perceptions of America as a powerful but malevolent nation decrease its security. On the basis of measures derived from the stereotype content model (SCM) and image theory (IT), 5,000 college students in 11 nations indicated their perceptions of the personality traits of, intentions of, and emotional reactions to the United States as well as their reactions to relevant world events (e.g., 9/11). The United States was generally perceived as competent but cold and arrogant. Although participants distinguished between the United States’ government and its citizens, differences were small. Consistent with the SCM and IT, viewing the United States as intent on domination predicted perceptions of lack of warmth and of arrogance but not of competence and status. The discussion addresses implications for terrorist recruitment and ally support. [less ▲]

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See detailDisused Palaeozoic regional stages from Belgium: Devillian, Revinian, Salmian, Gedinnian and Burnotian.
Dejonghe, L.; Herbosch, A.; Steemans, Philippe ULg et al

in Geologica Belgica (2006), 9(1-2), 191-197

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See detailEnigmatic Givetian palynomorphs
Steemans, Philippe ULg

Report (2006)

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See detailDetection of diverse mould species growing on building materials by gas sensor arrays and pattern recognition
Kuske, Martyna; Padilla, M.; Romain, Anne-Claude ULg et al

in Sensors and actuators. B, Chemical (2006), 119(1), 33-40

This work explores the detection of moulds growing in different building materials by using a metal oxide sensor array. Four moulds species have been considered. Pattern classification provides detection ... [more ▼]

This work explores the detection of moulds growing in different building materials by using a metal oxide sensor array. Four moulds species have been considered. Pattern classification provides detection rates on the order of 80-85% for different species. Drift degrades only slightly these values subsequent test 4 months later. [less ▲]

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See detailEstimation of odor emission rate from landfill areas using the sniffing team method
Nicolas, Jacques ULg; Craffe, Flavien; Romain, Anne-Claude ULg

in Waste Management (2006), 26(11), 1259-1269

The monitoring of the odor annoyance generated by a landfill area is difficult, since it is a multi-area-sources problem, with a discontinuous odor emission. This paper proposes an adaptation of the ... [more ▼]

The monitoring of the odor annoyance generated by a landfill area is difficult, since it is a multi-area-sources problem, with a discontinuous odor emission. This paper proposes an adaptation of the method of sniffing team campaigns to the particular case of fresh waste odors. The method is based on the field determination of odor perception points, followed by data processing with a bi-Gaussian-type model, adapted to handle the odors. In a first step, field observers delineate the region in which odor impact is experienced and then the emission rate is manipulated in a dispersion model until the predicted size of the impact zone matches that observed in the field. In a second step the adjusted emission rate is entered into the model to calculate the percentiles corresponding to the average annoyance zone. The originality of the proposed method is the introduction of all observation points and of all recorded meteorological data into the model. The paper discusses the method limitations and the errors induced on the results, i.e. the odor emission rate and the percentile lines (or iso-concentration lines) which are used to describe the odor concentrations on a map of the surroundings of the plant.The proposed method proves to be reliable for diffuse sources, such as landfill areas. The obtained results are coherent with other results found in the literature with other techniques. [less ▲]

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See detailL’analyse du travail : centrale ou simplement utile ?
De Keyser, Véronique ULg; Nyssen, Anne-Sophie ULg

in Vallery, Gérard; Amalberti, René (Eds.) L’analyse du travail en perspective – Influences et évolutions. (2006)

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See detailThe electronic nose as a warning device of the odour emergence in a compost hall
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Ledent, Catherine

in Sensors and actuators. B, Chemical (2006), 116(1-2), 95-99

A self-made electronic nose consisting in a sensor array of six commercial tin oxide gas sensors is used to monitor the odour emission from a compost facility. Supervised data processing tools, such as ... [more ▼]

A self-made electronic nose consisting in a sensor array of six commercial tin oxide gas sensors is used to monitor the odour emission from a compost facility. Supervised data processing tools, such as discriminant analysis, are able to recognize, in real time, the odour of compost with respect to other possible sources in the hall. The paper shows that with unsupervised methods, such as principal component analysis, it is not essential to identify all the possible odour sources during the learning phase. The closeness to the compost group centroid could be used as an indicator of the compost odour level. Alternatively, by a suitable calibration from olfactory measurements, the signals generated by the sensor array can be used to estimate the odour emission rate from the compost hall. Such real time monitoring should allow to assess and to anticipate the annoyance in the surrounding. [less ▲]

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See detailAbout automatic learning for advanced sensing, monitoring and control of electric power systems
Wehenkel, Louis ULg; Glavic, Mevludin; Geurts, Pierre ULg et al

in Proceedings of the Second Carnegie Mellon Conference in Electric Power Systems: Monitoring, Sensing, Software and its Valuation for the Changing electric Power Industry (2006)

The paper considers the possible uses of automatic learning for improving power system performance by software methodologies. Automatic learning per se is first reviewed and recent developements of the ... [more ▼]

The paper considers the possible uses of automatic learning for improving power system performance by software methodologies. Automatic learning per se is first reviewed and recent developements of the field are highlighted. Then the authors’ views of its main actual or potential applications related to power system operation and control are described, and in each application present status and needs for further developments are discussed. [less ▲]

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See detailOn multi-area security assessment of large interconnected power systems
Wehenkel, Louis ULg; Glavic, Mevludin; Ernst, Damien ULg

in Proceedings of the Second Carnegie Mellon Conference in Electric Power Systems: Monitoring, Sensing, Software and its Valuation for the Changing electric Power Industry (2006)

The paper introduces a framework for information exchange and coordination of security assessment suitable for distributed multi-area control in large interconnections operated by a team of transmission ... [more ▼]

The paper introduces a framework for information exchange and coordination of security assessment suitable for distributed multi-area control in large interconnections operated by a team of transmission system operators. The basic idea of the proposed framework consists of exchanging just enough information so that each operator can evaluate the impact in his control area of contingencies both internal and external to his area. The framework has been thought out with the European perspective in mind where it is presently not possible to set up a transnational security coordinator that would have authority to handle security control over the whole or part of the European interconnection. Nevertheless, it can also be considered as an approach to handle security control in North-American Mega-RTOs, where it could help to circumvent problems of scalability of algorithms and maintainability of data by distributing them over the TSOs under the authority of the RTO. [less ▲]

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See detailEnsembles of extremely randomized trees and some generic applications
Wehenkel, Louis ULg; Ernst, Damien ULg; Geurts, Pierre ULg

in Proceedings of Robust Methods for Power System State Estimation and Load Forecasting (2006)

In this paper we present a new tree-based ensemble method called “Extra-Trees”. This algorithm averages predictions of trees obtained by partitioning the inputspace with randomly generated splits, leading ... [more ▼]

In this paper we present a new tree-based ensemble method called “Extra-Trees”. This algorithm averages predictions of trees obtained by partitioning the inputspace with randomly generated splits, leading to significant improvements of precision, and various algorithmic advantages, in particular reduced computational complexity and scalability. We also discuss two generic applications of this algorithm, namely for time-series classification and for the automatic inference of near-optimal sequential decision policies from experimental data. [less ▲]

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See detailAutomatic learning of sequential decision strategies for dynamic security assessment and control
Wehenkel, Louis ULg; Glavic, Mevludin; Geurts, Pierre ULg et al

in Proceedings of the IEEE Power Engineering Society General Meeting 2006 (2006)

This paper proposes to formulate security control as a sequential decision making problem and presents new developments in automatic learning of sequential decision making strategies from simulations and ... [more ▼]

This paper proposes to formulate security control as a sequential decision making problem and presents new developments in automatic learning of sequential decision making strategies from simulations and/or information collected from real-life system measurements. The exploitation of these methods for the design of decision making strategies and control policies in the context of preventive and emergency mode dynamic security assessment and control is discussed and further opportunities for research in this area are highlighted. [less ▲]

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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 detailMulti-area security assessment: results using efficient bounding method
Wehenkel, Louis ULg; Glavic, Mevludin; Ernst, Damien ULg

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

We present our recent results on using previously introduced framework for multi-area security assessment in large interconnections. The basic idea of the framework is exchanging just enough information ... [more ▼]

We present our recent results on using previously introduced framework for multi-area security assessment in large interconnections. The basic idea of the framework is exchanging just enough information so that each operator can evaluate the impact in his control area of contingencies both internal and external to his area. We provide illustrations based on a localization concept known as efficient bounding method and recently introduced approximate DC model of the European interconnected system. In this paper we focus on four transmission system operators (within the approximate DC model): Belgium, France, Germany, and Netherlands (for both Summer and Winter-peak load conditions). [less ▲]

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See detailComparative assessment of old and new suboptimal control schemes on three example processes
Journee, Michel ULg; Schweickhardt, T.; Allgöwer, Frank

in Proceedings of the 13th IFAC Workshop on Control Applications of Optimisation, Paris (2006)

Detailed reference viewed: 6 (2 ULg)