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See detailPlanning under uncertainty, ensembles of disturbance trees and kernelized discrete action spaces
Defourny, Boris ULg; Ernst, Damien ULg; Wehenkel, Louis ULg

in Proceedings of the IEEE International Symposium on Adaptive Dynamic Programming and Reinforcement Learning (ADPRL-09) (2009)

Optimizing decisions on an ensemble of incomplete disturbance trees and aggregating their first stage decisions has been shown as a promising approach to (model-based) planning under uncertainty in large ... [more ▼]

Optimizing decisions on an ensemble of incomplete disturbance trees and aggregating their first stage decisions has been shown as a promising approach to (model-based) planning under uncertainty in large continuous action spaces and in small discrete ones. The present paper extends this approach and deals with large but highly structured action spaces, through a kernel-based aggregation scheme. The technique is applied to a test problem with a discrete action space of 6561 elements adapted from the NIPS 2005 SensorNetwork benchmark. [less ▲]

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See detailLECONS D'ANALYSE NUMERIQUE - DEUXIEME PARTIE
Debongnie, Jean-François ULg

Book published by DEBONGNIE (JEAN-FRANCOIS) (2009)

Version étoffée d'un cours donné par l'auteur à l'EMI, Rabat, de 1979 à 1985

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See detailLECONS D'ANALYSE NUMERIQUE - PREMIERE PARTIE
Debongnie, Jean-François ULg

Book published by DEBONGNIE (JEAN-FRANCOIS) (2009)

Version étoffée d'un cours donné par l'auteur à l'EMI (Rabat) de 1979 à 1985 (première partie)

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See detailPulse pressure and cardiovascular autonomic neuropathy according to duration of type 1 diabetes.
Philips, Jean-Christophe ULg; Marchand, Monique ULg; Scheen, André ULg

in Diabetes/Metabolism Research & Reviews (2009)

BACKGROUND: To evaluate changes in pulse pressure (PP) and markers of cardiovascular autonomic neuropathy (CAN) according to duration of type 1 diabetes mellitus (T1DM). METHODS: This cross-sectional ... [more ▼]

BACKGROUND: To evaluate changes in pulse pressure (PP) and markers of cardiovascular autonomic neuropathy (CAN) according to duration of type 1 diabetes mellitus (T1DM). METHODS: This cross-sectional controlled study evaluated 159 diabetic patients during a 3-min posture test (standing-squatting-standing) with continuous measurement of systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure by a Finapres device. Arterial stiffness was indirectly assessed by PP and the slope of PP as a function of MBP calculated during the whole 3-min test. CAN was assessed by the expiration/inspiration pulse interval ratio (E/I R-R ratio) during deep breathing and by three indices measured during the squatting test. Patients were divided into four groups according to diabetes duration (<10 years, 11-20 years, 21-30 years and > 30 years from group 1 to group 4, respectively) and compared with age-matched non-diabetic subjects. RESULTS: PP progressively increased (p < 0.0001) and PP/MBP decreased (p < 0.0005) according to T1DM duration, whereas these parameters remained almost unchanged in age-matched control subjects. E/I ratio (p < 0.0001) and baroreflex gain (p < 0.0005) progressively decreased with T1DM duration. The parasympathetic index (squatting test vagal ratio-SqTv) significantly increased (p < 0.0001), whereas the sympathetic index (squatting test sympathetic ratio-SqTs) only tended to decrease (p = 0.12) according to diabetes duration. No such changes in CAN indices were observed in the non-diabetic population. CONCLUSIONS: PP increased according to T1DM duration in an age range where PP remained almost stable in controls, in agreement with accelerated arterial stiffening due to chronic hyperglycaemia. The baroreflex gain decreased and other indices of CAN also deteriorated with diabetes duration, more so indices reflecting parasympathetic rather than sympathetic dysfunction. [less ▲]

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See detailRosiglitazone: to be or not to be?
Scheen, André ULg

in Diabetologia (2009), 52(7), 1448-50

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See detailVoglibose for prevention of type 2 diabetes mellitus.
Scheen, André ULg

in Lancet (2009), 373(9675), 1579-80

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See detailLimit analysis of the statistics of quasi-steady non-linear aerodynamic forces for small turbulence intensities
Denoël, Vincent ULg

in Probabilistic Engineering Mechanics (2009), 24(4), 552-564

This paper focuses on the estimation of statistical characteristics of a specific quasi-steady wind loading used in buffeting analyses. In this loading, the intrinsic non-linearity of aerodynamic ... [more ▼]

This paper focuses on the estimation of statistical characteristics of a specific quasi-steady wind loading used in buffeting analyses. In this loading, the intrinsic non-linearity of aerodynamic coefficients is considered and approached by a polynomial expression of any a priori chosen degree. As rigorous developments of the statistical moments would result in impractical formulations, we suggest to consider the smallness of the turbulence intensities to construct, by means of a limit analysis, approximate expressions of the raw moments of aerodynamic forces. From these expressions, approximate cumulants and associated dimensionless characteristics, such as skewness and excess coefficients, are derived. The accuracy of the proposed analytical relations is assessed by comparison with Monte Carlo simulations, and the relevance of the sophisticated non-linear loading under consideration is compared to more traditional models. [less ▲]

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See detailSurface functionalization of germanium ATR devices for use in FTIR-biosensors
Devouge, S.; Conti, J.; Goldsztein, A. et al

in Journal of Colloid & Interface Science (2009), 332(2), 408-415

Biosensors based on intrinsic detection methods have attracted growing interest. The use of Fourier transform infra-red (FTIR) spectroscopy with the attenuated internal total reflection (ATR) mode, in the ... [more ▼]

Biosensors based on intrinsic detection methods have attracted growing interest. The use of Fourier transform infra-red (FTIR) spectroscopy with the attenuated internal total reflection (ATR) mode, in the biodetection context, requires appropriate surface functionalization of the ATR optical element. Here, we report the direct grafting of a thin organic layer (about 20 angstrom depth) on the surface of a germanium crystal. This covering, constructed with novel amphiphilic molecules 2b (namely, 2,5,8,11,14,17,20-heptaoxadocosan-22-yl-3-(triethoxysilyl) propylcarbamate), is stable for several hours under phosphate buffered saline (PBS) flux and features protein-repulsive properties. Photografting of molecule 5 (namely, O-succinimidyl 4-(p-azidophenyl)butanoate) affords the activated ATR element, ready for the covalent fixation of receptors, penicillin recognizing proteins BlaR-CrD for instance. The different steps of the previous construction have been monitored by water contact angle (theta(w)) measurements, spectroscopic ellipsometry (covering depth), X-ray photoelectron spectroscopy (XPS) by using a fluorinated tag for the control of surface reactivity, and FTIR-ATR spectroscopy for the structural analysis of grafted molecules. Indeed, contrarily to silicon device, germanium device offers a broad spectral window (1000-4000 cm(-1)) and thus amide I and II absorption bands can be recorded. This work lays the foundations for the construction of novel FTIR biosensors. (c) 2008 Elsevier Inc. All rights reserved. [less ▲]

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See detailMultiple mode analysis of the self-excited vibrations of rotary drilling systems
Germay, Christophe; Denoël, Vincent ULg; Detournay, Emmanuel

in Journal of Sound & Vibration (2009), 325(1-2), 362-381

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See detailLong Term Stability Of Metal Oxide-Based Gas Sensors For E-nose Environmental Applications: an overview
Romain, Anne-Claude ULg; Nicolas, Jacques ULg

in Pardo, Matteo; Sberveglieri, Giorgio (Eds.) OLFACTION AND ELECTRONIC NOSE: Proceedings of the 13th International Symposium on Olfaction and Electronic Nose (2009)

The e-nose technology has enormous potentialities for in site monitoring of malodors. However a number of limitations are associated with the properties of chemical sensors, the performances of the signal ... [more ▼]

The e-nose technology has enormous potentialities for in site monitoring of malodors. However a number of limitations are associated with the properties of chemical sensors, the performances of the signal processing and the realistic operation conditions of environmental field. From the experience of the research group in the field, the metal oxide based gas sensors (Figaro type) are until now the best chemical sensors for long term application, more than one year of continuous working in the field. To be usable for malodors measurement in the field, the e-nose has to deal with the lack of long term stability of these sensors. The drift and the sensors replacement have to be considered. In order to appraise the time evolution of the sensors and the effect on the results of an electronic nose, experimentation has been performed during three years on two identical sensor arrays. The two arrays contain the same six Figaro sensors and are in the same sensor chamber of the e-nose system. Both arrays have worked continuously during three years without break. [less ▲]

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See detailEntre prose, vers et image. Ambivalence du message politique dans les Chroniques de Louis XII de Jean d’Auton
Dumont, Jonathan ULg

in MethIS : Méthodes et Interdisciplinarité en Sciences Humaines (2009), 2

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See detailCocaïne and metabolites in waste and surface water across Belgium.
Van Nuijs, Alexander; Pecceu, Bert; Theunis, Laetitia ULg et al

in Environmental Pollution (2009), 157

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See detailReconciling opposing views on carbon cycling in the coastal ocean: continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2
Chen, C. T. A.; Borges, Alberto ULg

in Deep-Sea Research Part II, Topical Studies in Oceanography (2009), 56(8-10), 578-590

Despite their moderately-sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of ... [more ▼]

Despite their moderately-sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of carbon and nutrients, sustaining a disproportionate large biological activity compared to their relative surface area. A synthesis of worldwide measurements of the partial pressure of CO2 (pCO2) indicates that most open shelves in the temperate and high latitude regions are under-saturated with respect to atmospheric CO2 during all seasons, although the low latitude shelves seem to be over-saturated. Most inner estuaries and near-shore coastal areas on the other hand are over-saturated with respect to atmospheric CO2. The scaling of air-sea CO2 fluxes based on pCO2 measurements and carbon mass balance calculations indicate that the continental shelves absorb atmospheric CO2 ranging between 0.33 to 0.36 Pg C yr-1 that corresponds to an additional sink of 27% to ~30% of the CO2 uptake by the open oceans based on the most recent pCO2 climatology (Takahashi et al., 2008; Deep-Sea Research II, this issue). Inner estuaries, salt marshes and mangroves emit up to 0.50 Pg C yr-1, although these estimates are prone to large uncertainty due to poorly constrained ecosystem surface area estimates. Nevertheless, the view of continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2 allows reconciling long-lived opposing views on carbon cycling in the coastal ocean. [less ▲]

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See detailDe l’Education physique aux Sciences de la motricité. Mise en place de la réforme « Bologne » à l’Université de Liège
Cloes, Marc ULg

in Revue de l'Education Physique (2009), 49(1), 24-34

En Communauté française de Belgique, l’application des directives européennes concernant l’harmonisation de l’enseignement supérieur s’est appuyée sur le désormais célèbre décret « Bologne » (Ministère de ... [more ▼]

En Communauté française de Belgique, l’application des directives européennes concernant l’harmonisation de l’enseignement supérieur s’est appuyée sur le désormais célèbre décret « Bologne » (Ministère de la Communauté française, 2004). Mis en application à partir de l’année académique 2004-2005, ce dernier a scellé l’avenir de plusieurs générations de jeunes et imposé de profondes modifications dans la structure des formations proposées depuis des décennies. Dans cet article, nous nous proposons de synthétiser les principaux changements dans l’organisation des études supérieures et d’illustrer le programme qui a été conçu dans le domaine de la motricité humaine au sein de l’Institut supérieur d’Education physique et de Kinésithérapie de l’Université de Liège. Nos propos visent à fournir des informations qui permettront aux porteurs de diplômes antérieurs à 2004 de se familiariser à la terminologie actuelle et à visualiser la manière avec laquelle l’université a évolué en réponse aux directives des pouvoirs publics. [less ▲]

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See detailInferring bounds on the performance of a control policy from a sample of trajectories
Fonteneau, Raphaël ULg; Murphy, Susan; Wehenkel, Louis ULg et al

in Proceedings of the IEEE International Symposium on Adaptive Dynamic Programming and Reinforcement Learning (ADPRL-09) (2009)

We propose an approach for inferring bounds on the finite-horizon return of a control policy from an off-policy sample of trajectories collecting state transitions, rewards, and control actions. In this ... [more ▼]

We propose an approach for inferring bounds on the finite-horizon return of a control policy from an off-policy sample of trajectories collecting state transitions, rewards, and control actions. In this paper, the dynamics, control policy, and reward function are supposed to be deterministic and Lipschitz continuous. Under these assumptions, a polynomial algorithm, in terms of the sample size and length of the optimization horizon, is derived to compute these bounds, and their tightness is characterized in terms of the sample density. [less ▲]

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See detailPsychological harassment in the workplace : case-study and building of a new analysis model.
Faulx, Daniel ULg; Delvaux, Sophie; Brun, Jean-Pierre

in Relations Industrielles = Industrial Relations (2009), 64(2), 286-306

From a case-study based on an analysis model, which takes into account four levels of explanation (personal, interpersonal, group and organizational), and includes the study of the interactions between ... [more ▼]

From a case-study based on an analysis model, which takes into account four levels of explanation (personal, interpersonal, group and organizational), and includes the study of the interactions between these different levels, this report puts forward six observations: (1) the importance of performing the analysis on several levels, (2) the existence within harassment situations of two types of process (victimizing and conflictual), (3) the fact that these processes can co- exist at different levels of analysis, (4) the existence of interactions between processes, (5) the variability of a situation across time, and (6) the necessity of distinguishing two categories of influence involved in contextual processes. From these conclusions, the authors develop a new analysis model, which is process- based, integrative and dynamic. [less ▲]

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See detailNew multi-station and multi-decadal trend data on precipitable water. Recipe to match FTIR retrievals from NDACC long-time records to radio sondes within 1mm accuracy/precision
Sussmann, Ralf; Borsdorf, Tobias; Rettinger, M. et al

in Geophysical Research Abstracts (2009), 11

We present an original optimum strategy for retrieval of precipitable water from routine ground-based midinfrared FTS measurements performed at a number globally distributed stations within the NDACC ... [more ▼]

We present an original optimum strategy for retrieval of precipitable water from routine ground-based midinfrared FTS measurements performed at a number globally distributed stations within the NDACC network. The strategy utilizes FTIR retrievals which are set in a way to match standard radio sonde operations. Thereby, an unprecedented accuracy and precision for measurements of precipitable water can be demonstrated: the correlation between Zugspitze FTIR water vapor columns from a 3 months measurement campaign with total columns derived from coincident radio sondes shows a regression coefficient of R = 0.988, a bias of 0.05 mm, a standard deviation of 0.28 mm, an intercept of 0.01 mm, and a slope of 1.01. This appears to be even better than what can be achieved with state-of-the-art micro wave techniques, see e.g., Morland et al. (2006, Fig. 9 therein). Our approach is based upon a careful selection of spectral micro windows, comprising a set of both weak and strong water vapor absorption lines between 839.4 – 840.6 cm-1, 849.0 – 850.2 cm-1, and 852.0 – 853.1 cm-1, which is not contaminated by interfering absorptions of any other trace gases. From existing spectroscopic line lists, a careful selection of the best available parameter set was performed, leading to nearly perfect spectral fits without significant forward model parameter errors. To set up the FTIR water vapor profile inversion, a set of FTIR measurements and coincident radio sondes has been utilized. To eliminate/minimize mismatch in time and space, the Tobin best estimate of the state of the atmosphere principle has been applied to the radio sondes. This concept uses pairs of radio sondes launched with a 1-hour separation, and derives the gradient from the two radio sonde measurements, in order to construct a virtual PTU profile for a certain time and location. Coincident FTIR measurements of water vapor columns (two hour mean values) have then been matched to the water columns obtained by integrating the best-estimate radio sonde profiles. This match was achieved via investigating the quality of the correlation plots between the columns derived from the radio sondes and the FTIR retrievals, and iteratively tuning the regularization strength of the FTIR retrieval. The FTIR regularization matrix is based on a Tikhonov operator which allows for empirical tuning of the regularization strength via one parameter. The figures of merit for the iterative tuning have been the slope, the intercept, and the regression coefficient of the correlation. By this way an optimum retrieval setting could be found, guaranteeing a response of the FTIR retrievals to true water vapor changes, which is matched to the radio sonde operation. As first examples for utilizing this approach to derive long-term trends of precipitable water from NDACC type long-term FTIR measurements, we present trends from two time series. I.e., one retrieved from continuous FTIR measurements at the NDACC Primary Station Zugspitze, Germany (47.42 °N, 10.98 °E, 2964 m a.s.l.), which covers the time span 1995-2009, and one from the International Scientific Station of the Jungfraujoch (ISSJ, 46.5°N, 8.0°E, 3580m a.s.l., Swiss Alps), covering the time span 1984 – 2009. A detailed trend analysis of both series via the bootstrap method will be presented. In ongoing work we apply this optimum retrieval approach to historical long-time measurement series of further selected FTIR stations of the NDACC network. Thereby we will obtain unprecedented new climate data via long term trends of precipitable water at a set of globally distributed locations. [less ▲]

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See detailBipolarity in Alexis de Tocqueville’s, Karl Marx’s, Friedrich Nietzsche’s, and Michael Oakeshott’s Political Theories
Reuchamps, Min ULg

in Cahiers de Sciences Politiques de l'ULg (2009), (15),

In Democracy in America, Alexis de Tocqueville argues that passions for both equality and liberty constitute the chief attributes of liberal democracy. In the same century, Karl Marx and Friedrich Engels ... [more ▼]

In Democracy in America, Alexis de Tocqueville argues that passions for both equality and liberty constitute the chief attributes of liberal democracy. In the same century, Karl Marx and Friedrich Engels –followed by Lenin in the 20th century– contend that history is chiefly characterized by the conflict between those who own the means of productions and those who don’t –those who produce. In Beyond Good and Evil (BGE) and in On the Genealogy of Morals (OGM), Friedrich Nietzsche describes the whole of history as a permanent bipolarity between the strong –committed to the master morality of good vs. bad– and the weak –committed to the slave morality of good vs. evil. Michael Oakeshott, in The Politics of Faith and The Politics of Scepticism, suggests that, since the fifteenth century, modern politics can be characterized by two –logically opposite and yet practically complementary– styles of politics: the politics of faith and the politics of scepticism. Although they disagree on the characterization of the poles themselves, all four philosophers describe politics as a bipolarity: a dynamic between two poles. In this paper, I shall attempt to describe –and then reflect on– the dynamics of bipolarity in these four major works of political theory. Six sets of questions inform the essay. First, was there ever a time in which the political poles identified by the author were either nonexistent or different from the currently predominant or ultimate ones? If so, then why and what were the characteristics of that time? Second, what characterizes the political poles? Are the apparent poles more complicated than what meets the eye upon a first reading? Does the author reveal dimensions, levels, or different incarnations of the poles, or in fact more than two poles? Third, are the characteristics of the poles altered in any way by either political actors, or by way of their confrontation or interaction with one another? If so, how? If not, then why not? Fourth, does the identified bipolarity spontaneously create a political equilibrium or evolve into another, or is intervention required to produce an equilibrium or evolution? Fifth, if the latter, does the author recommend such intervention? Does the author give a normative teaching or assess the identified poles? Sixth, is the bipolarity theory valid? Does it accurately describe politics? The paper opens with the discussion of the first two sets of questions –i.e. the characterization of politics by Tocqueville, Marx, Nietzsche, and Oakeshott. The second section focuses on the intricate dynamics between the poles and on the mediation occurring between them –i.e. the third and fourth sets of questions. The fifth sets of question –i.e. whether the author gives a descriptive or a normative teaching– informs the third section of the paper. In the conclusion, I attempt to offer a personal view to the final question –i.e. the validity of the bipolarity theory offered by the four philosophers– and try to answer it in the Belgian federal context. [less ▲]

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See detailProduction des anticorps monoclonaux
Mistretta, Virginie ULg; Cavalier, Etienne ULg; Collette, Julien ULg et al

in Revue Médicale de Liège (2009), 64(5-6), 248-252

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