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See detailBias-variance tradeoff of soft decision trees
Olaru, Cristina; Wehenkel, Louis ULg

(2004)

This paper focuses on the study of the error composition of a fuzzy decision tree induction method recently proposed by the authors, called soft decision trees. This error may be expressed as a sum of ... [more ▼]

This paper focuses on the study of the error composition of a fuzzy decision tree induction method recently proposed by the authors, called soft decision trees. This error may be expressed as a sum of three types of error: residual error, bias and variance. The paper studies empirically the tradeoff between bias and variance in a soft decision tree method and compares it with the tradeoff of classical crisp regression and classification trees. The main conclusion is that the reduced prediction variance of fuzzy trees is the main reason for their improved performance with respect to crisp ones. [less ▲]

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See detailOperation rules determined by risk analysis for special protection systems at Hydro-Québec
Huang, Jinan; Vanier, Guy; Valette, Alain et al

(2004)

This paper describes a new approach used by Hydro-Québec to determine the rules of automatic devices installed in its main power plants to maintain secure operation under extreme contingencies. An example ... [more ▼]

This paper describes a new approach used by Hydro-Québec to determine the rules of automatic devices installed in its main power plants to maintain secure operation under extreme contingencies. An example of application of this approach is given to illustrate how to apply data mining technique for the rules of the automatic generator rejection and remote load shedding system (RPTC: Rejet de Production et Télédélestage de Charges in French) installed at the Churchill Falls hydroelectric power plant (5500 MW) in Labrador. Real time snapshots of the Hydro-Québec power system collected over several years data have been used to generate large amounts of results (database) by transient stability simulations. The database is processed by the data mining software developed by the University of Liege to construct the decision trees. This approach gives the most relevant parameters and finds optimal settings for the RPTC system at the Churchill Falls, minimizing the number of generator rejection while maintaining the same performance in terms of security coverage. New operation rules have thus been established. [less ▲]

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See detailWhither dynamic congestion management ?
Wehenkel, Louis ULg

(2004)

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See detailPreventive vs. emergency control of power systems
Wehenkel, Louis ULg; Pavella, Mania ULg

(2004)

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. The ... [more ▼]

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. The organization of the resulting control schemes is then revisited in order to make it able to cover static and voltage security, in addition to transient stability. Distinct approaches for preventive and emergency operating conditions are advocated. [less ▲]

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See detailA Set of Equity Indicators of the European Education Systems A synthesis
Demeuse, Marc; Baye, Ariane ULg; Straeten, Marie-Hélène et al

in Moreno Herrera, L.; Francia, G. (Eds.) Educational Policies. Implications for Equity, Equality and Equivalence (2004)

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See detailThe evolution of inorganic chlorine above the Jungfraujoch station: an update.
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Zander, Rodolphe ULg et al

in Zerefos, C. S. (Ed.) Proceedings of the 20th Quadrennial Ozone Symposium (2004)

Within the frame of the NDSC, the total vertical column abundances of HCl and ClONO2, by far the two most important inorganic chlorine reservoirs at northern mid-latitudes, have been further monitored ... [more ▼]

Within the frame of the NDSC, the total vertical column abundances of HCl and ClONO2, by far the two most important inorganic chlorine reservoirs at northern mid-latitudes, have been further monitored above the Jungfraujoch station (Swiss Alps, 46.5ºN, 8.0ºE, 3580m a.s.l.), by analyzing infrared solar absorption spectra recorded with very high-resolution Fourier spectrometers. The mean temporal evolution of the sum of their monthly mean abundance time series indicates that the total stratospheric inorganic chlorine loading (Cly) has decreased slowly (-0.7+/-0.3%/yr, 1-sigma) since it peaked in late 1996, at the limit of being statistically significant at the 2-sigma level. Comparison with model calculations and with the evolution of surface total organic chlorine will also be discussed. [less ▲]

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See detailGround-based FTIR measurements of O3- and climate-related gases in the free troposphere and lower stratosphere
De Mazière, M.; Barret, B.; Vigouroux, C. et al

in Zerefos, C. S. (Ed.) Proceedings Quadrennial Ozone Symposium (2004)

In the frame of the EC project UFTIR (Time series of Upper Free Troposphere observations from a European ground-based FTIR network), a common strategy for an optimal determination of the chemical ... [more ▼]

In the frame of the EC project UFTIR (Time series of Upper Free Troposphere observations from a European ground-based FTIR network), a common strategy for an optimal determination of the chemical composition in the free troposphere and lower stratosphere with ground-based Fourier-transform infrared (FTIR) spectrometers is being developed. The project focuses on 6 target species that are O3, CO, CH4, N2O, C2H6 and CHClF2 (HCFC-22). The strategy consists in selecting the most appropriate parameters to retrieve vertical concentration profiles from solar FTIR spectra. Among the important parameters are the spectral microwindows: they have been optimised to maximise the information content and to minimize the influence of poorly known spectroscopic data and interfering species. [less ▲]

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See detailRenforcement de la capacité de gestion des ressources en eau dans l'agriculture moyennant des outils de suivi-évaluation (Burkina Faso): Rapport Technique (2004)
Wellens, Joost ULg; Compaore, Nestor; Van Orshoven, Jos et al

Report (2004)

L’approche proposée par le projet existe dans la combinaison des besoins en formation des ingénieurs de haut niveau de l’EIER d’une part avec les besoins de la DRH-HB d’autre part. En utilisant le système ... [more ▼]

L’approche proposée par le projet existe dans la combinaison des besoins en formation des ingénieurs de haut niveau de l’EIER d’une part avec les besoins de la DRH-HB d’autre part. En utilisant le système d’information géographique de la DRH-HB le projet a comme objectif de développer des outils informatiques qui peuvent aider à gérer mieux l’eau et qui ont la capacité de formuler une estimation précise du rendement des cultures pluviales dans la région pendant la saison. Afin de garantir des effets multiplicateurs et spin-off, et de disposer d’un nombre suffisant de chercheurs qui travailleront dans le cadre du projet sans exagérer les coûts, les outils seront développés dans le cadre des mémoires de fin d’études des meilleurs étudiants africains des quatorze états subsahariens de l’EIER et des étudiants des Universités flamandes. [less ▲]

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See detailA pilot study of silicone tissue expander prosthesis to protect the small bowel during radiation therapy for uterine malignancies
Zouhair, Abderrahim; Delaloye, J-F; Oszahin, Mahmut et al

in Turkish Journal of Cancer (2004), 34(1), 11-18

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See detailNouvelles mobilités et réseaux sociaux locaux en milieu rural
Schmitz, Serge ULg

in Montulet, Bertrand; Kaufmann, Vincent (Eds.) Mobilités, fluidités... libertés ? (2004)

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See detailConcrete surface treatments quantification by means of mechanical profilometry
Courard, Luc ULg; Garbacz, Andrzej; Gorka, M.

in Maultzsch, M. (Ed.) Proceedings of the 11th International Congress on Polymers in Concrete ICPIC 2004 (2004)

Existing concrete surfaces need to be roughened to a profile necessary to achieve mechanical interlock with repair material. Surface mechanical morphometry is based on the measurement of surface profile ... [more ▼]

Existing concrete surfaces need to be roughened to a profile necessary to achieve mechanical interlock with repair material. Surface mechanical morphometry is based on the measurement of surface profile - profilometry - which can be extended to 3D representation with surfometry by means of a stylus registering the profile. Profilometry and surfometry analysis were realized on concrete after different surface treatments (grinding, sandblasting, shotblasting, hand- and mechanical milling). The profile has been quantified by means of statistical and amplitude parameters calculated from the waviness (lower frequencies) and the roughness (higher frequencies) profiles of the surface. Bearing ratio and Abbott's curve observations are also very useful to characterise surface profiles. [less ▲]

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See detailLe paysage invisible.
Schmitz, Serge ULg

in Puech, Daniel; Rivière-Honegger, Anne (Eds.) L'évaluation du paysage : une utopie nécessaire ? (2004)

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See detailSkin compatibility of cyclodextrins and their derivatives: a comparative assessment using a corneoxenometry bioassay.
Piel, Géraldine ULg; Moutard, S.; Uhoda, Emmanuelle ULg et al

in European Journal of Pharmaceutics & Biopharmaceutics (2004), 57(3), 479-82

Few studies have been performed to assess the risk of skin damage by cyclodextrins (CD) and they have yielded contradictory results. The present study was conducted using the corneoxenometry bioassay on ... [more ▼]

Few studies have been performed to assess the risk of skin damage by cyclodextrins (CD) and they have yielded contradictory results. The present study was conducted using the corneoxenometry bioassay on human stratum corneum to compare the skin compatibility of CD currently used in pharmaceutical preparations (betaCD, gammaCD, Rameb, Dimeb, Trimeb, HP-betaCD and HP-gammaCD) and that of new amphiphilic CD derivatives, namely, the phospholipidyl-CD (DMPE-Dimeb and DMPE-Trimeb). All the tested CD were well tolerated by the stratum corneum at a concentration of 5%. However, inter-individual reactivity was larger for DMPE-Dimeb, suggesting a more aggressive trend for this compound. Cutaneous Index of Mildness values obtained confirm that Dimeb is able to extract some skin components and shows that DMPE-Dimeb performs similarly. [less ▲]

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See detailDatabase and general modelling concepts for groundwater modelling in the SQUASH Project
Orban, Philippe ULg; Popescu, Ileana-Cristina; Ruthy, Ingrid ULg et al

in Hidrotehnica (2004), 49(9-10), 51-57

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See detailAnalyse explicative des influences observables de la reconnaissance et de la validation des compétences : le cas du PMTIC.
Pierrard, Jean-François; Brundseaux, Marie-France ULg; Georges, François ULg et al

in L'évaluation des compétences: entre reconnaissance et validation des acquis de l'expérience (2004)

L’article présente une réflexion théorique argumentée sur le manque de justifications empiriquement fondées de la mise en place de la reconnaissance et de la Validation des Acquis de l’Expérience et sur ... [more ▼]

L’article présente une réflexion théorique argumentée sur le manque de justifications empiriquement fondées de la mise en place de la reconnaissance et de la Validation des Acquis de l’Expérience et sur les effets observables que celle-ci est censée avoir sur tous ceux et toutes celles qui en bénéficient. Pour étoffer la réflexion théorique, l’article présente, en outre, les résultats provisoires d’une étude de terrain réalisée, en Belgique francophone, sur les acteurs du Plan Mobilisateur aux Technologies de l’Information et de la Communication (PMTIC) ; acteurs qui reçoivent, chacun à leur échelon, la reconnaissance et la validation de leurs compétences par l’acteur de l’échelon supérieur. [less ▲]

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See detailPositive interactive radiosensitization observed in vitro with the combination of two nucleoside analogs (E)-2'-deoxy-2'-(fluoromethylene) cytidine (FMdC) and iododeoxyuridine (IdUrd).
Coucke, Philippe ULg; Cottin, E; Azria, D et al

in European Journal of Cancer (2004)

(E)-20-Deoxy-20-(fluoromethylene) cytidine (FMdC), an inhibitor of ribonucleotide diphosphate reductase (RR), is a potent radiation-sensitiser acting through alterations in the deoxyribonucleoside ... [more ▼]

(E)-20-Deoxy-20-(fluoromethylene) cytidine (FMdC), an inhibitor of ribonucleotide diphosphate reductase (RR), is a potent radiation-sensitiser acting through alterations in the deoxyribonucleoside triphosphate (dNTP) pool in the de novo pathway to DNA synthesis. The activity of thymidine kinase (TK), a key enzyme in the ‘salvage pathway’, is known to increase in response to a lowering of dATP induced by FMdC. Nucleoside analogues such as iododeoxyuridine (IdUrd) are incorporated into DNA after phosphorylation by TK. Radiation sensitisation by IdUrd depends on IdUrd incorporation. Therefore, we have investigated the radiosensitising effect of the combination of FMdC and IdUrd on WiDr (a human colon cancer cell-line) and compared it to the effect of either drug alone. We analysed the effects of FMdC and IdUrd on the dNTP pools by high-performance liquid chromatography, and measured whether the incorporation of IdUrd was increased by FMdC using a [125I]-IdUrd incorporation assay. The combination in vitro yielded radiation-sensitiser enhancement ratios of >2, significantly higher than those observed with FMdC or IdUrd alone. Isobologram analysis of the combination indicated a supra-additive effect. This significant increase in radiation sensitivity with the combination of FMdC and IdUrd could not be explained by changes in the dNTP pattern since the addition of IdUrd to FMdC did not further reduce the dATP. However, the increase in the radiation sensitivity of WiDr cells might be due to increased incorporation of IdUrd after FMdC treatment. Indeed, a specific and significant incorporation of IdUrd into DNA could be observed with the [125I]-IdUrd incorporation assay in the presence of 1 lM unlabelled IdUrd when combined with FMdC treatment. 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailDecreased local control following radiation therapy alone in early stage glottic carcinoma with anterior commissure extention.
Azria, D; COUCKE, Philippe ULg; Matzinger, O et al

in Sonderbande zur Strahlentherapie und Onkologie (2004), 2

Purpose: To assess the patterns of failure in the treatment of early-stage squamous cell carcinoma of the glottic larynx. Patients and Methods: Between 1983–2000, 122 consecutive patients treated for ... [more ▼]

Purpose: To assess the patterns of failure in the treatment of early-stage squamous cell carcinoma of the glottic larynx. Patients and Methods: Between 1983–2000, 122 consecutive patients treated for early laryngeal cancer (UICC T1N0 and T2N0) by radical radiation therapy (RT) were retrospectively studied. Male-to-female ratio was 106 : 16, and median age 62 years (35–92 years). There were 68 patients with T1a, 18 with T1b, and 36 with T2 tumors. Diagnosis was made by biopsy in 104 patients, and by laser vaporization or stripping in 18. Treatment planning consisted of three-dimensional (3-D) conformal RT in 49 (40%) patients including nine patients irradiated using arytenoid protection. A median dose of 70 Gy (60–74 Gy) was given (2 Gy/fraction) over a median period of 46 days (21–79 days). Median follow-up period was 85 months. Results: The 5-year overall, cancer-specific, and disease-free survival amounted to 80%, 94%, and 70%, respectively. 5-year local control was 83%. Median time to local recurrence in 19 patients was 13 months (5–58 months). Salvage treatment consisted of surgery in 17 patients (one patient refused salvage and one was inoperable; total laryngectomy in eleven, and partial laryngectomy or cordectomy in six patients). Six patients died because of laryngeal cancer. Univariate analyses revealed that prognostic factors negatively influencing local control were anterior commissure extension, arytenoid protection, and total RT dose < 66 Gy. Among the factors analyzed, multivariate analysis (Cox model) demonstrated that anterior commissure extension, arytenoid protection, and male gender were the worst independent prognostic factors in terms of local control. Conclusion: For early-stage laryngeal cancer, outcome after RT is excellent. In case of anterior commissure extension, surgery or higher RT doses are warranted. Because of a high relapse risk, arytenoid protection should not be attempted. [less ▲]

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