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See detailPRoNTo: Pattern Recognition for Neuroimaging Toolbox
Schrouff, Jessica ULg; Rosa, Maria Joao; Rondina, Jane et al

in Neuroinformatics (2013)

In the past years, mass univariate statistical analyses of neuroimaging data have been complemented by the use of multivariate pattern analyses, especially based on machine learning models. While these ... [more ▼]

In the past years, mass univariate statistical analyses of neuroimaging data have been complemented by the use of multivariate pattern analyses, especially based on machine learning models. While these allow an increased sensitivity for the detection of spatially distributed effects compared to univariate techniques, they lack an established and accessible software framework. The goal of this work was to build a toolbox comprising all the necessary functionalities formultivariate analyses of neuroimaging data, based on machine learning models. The “Pattern Recognition for Neuroimaging Toolbox” (PRoNTo) is open-source, cross-platform, MATLAB-based and SPM compatible, therefore being suitable for both cognitive and clinical neuroscience research. In addition, it is designed to facilitate novel contributions from developers, aiming to improve the interaction between the neuroimaging and machine learning communities. Here, we introduce PRoNTo by presenting examples of possible research questions that can be addressed with the machine learning framework implemented in PRoNTo, and cannot be easily investigated with mass univariate statistical analysis. [less ▲]

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See detailPRoNTo: Pattern Recognition for Neuroimaging Toolbox
Schrouff, Jessica ULg; Rosa, Maria Joao; Rondina, Jane et al

Software (2012)

PRoNTo (Pattern Recognition for Neuroimaging Toolbox) is a software toolbox based on pattern recognition techniques for the analysis of neuroimaging data. Statistical pattern recognition is a field within ... [more ▼]

PRoNTo (Pattern Recognition for Neuroimaging Toolbox) is a software toolbox based on pattern recognition techniques for the analysis of neuroimaging data. Statistical pattern recognition is a field within the area of machine learning which is concerned with automatic discovery of regularities in data through the use of computer algorithms, and with the use of these regularities to take actions such as classifying the data into different categories. In PRoNTo, brain scans are treated as spatial patterns and statistical learning models are used to identify statistical properties of the data that can be used to discriminate between experimental conditions or groups of subjects (classification models) or to predict a continuous measure (regression models). PRoNTo aims to facilitate the interaction between machine learning and neuroimaging communities. On one hand, the machine learning community can contribute to the toolbox with novel machine learning models. On the other hand, the toolbox provides a variety of tools for the neuroscience and clinical neuroscience communities, enabling them to ask new questions that cannot be easily investigated using existing software and analysis tools. PRoNTo is distributed for free as copyright software under the terms of the GNU General Public License as published by the Free Software Foundation. The development of the toolbox has been supported by the PASCAL Harvest framework and The Wellcome Trust. [less ▲]

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See detailA proof of concept of Iterative DSM improvement through SAR scene simulation
De Rauw, Dominique ULg

in ISPRS Journal of Photogrammetry & Remote Sensing (2009), XXXVIII(3/W4), 121-126

In Very High Resolution (VHR) Synthesis Aperture Radar (SAR) context, very fine and accurate georeferencing and geoprojection processes are required. Both operations are only applicable if accurate local ... [more ▼]

In Very High Resolution (VHR) Synthesis Aperture Radar (SAR) context, very fine and accurate georeferencing and geoprojection processes are required. Both operations are only applicable if accurate local heights are known. 3D information may be derived from SAR interferometry (InSAR), But in VHR context, InSAR reveals to be inaccurate mostly due to phase unwrapping problems and to phase/height noise. Generated InSAR Digital Surface Models (DSM) can only be considered as a first good approximation of the observed surface. Therefore, we proposed to start from the InSAR DSM, to project it on ground range on a given datum, to model the observed scene using this projected DSM, then to simulate in slant range the intensity image issued from this structure model. Comparison between simulated and observed intensity image can then be used as a criterion to modify and improve the considered underlying DSM. In this paper, we present the different steps of the proposed approach and results obtained so far, showing that the proposed process can be run iteratively to modify the DSM and reach a stable solution. [less ▲]

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See detailLa propagande culturelle française à destination de la Flandre, 1944-1960
Lanneau, Catherine ULg

Conference (2011, October 07)

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See detailPropagation de fumées
Dumont, Fabien ULg; Alonso, Alain; Franssen, Jean-Marc ULg

Report (2010)

The aim of the project is to see whether it makes a difference in term of propagation of smoke to compartments outside the fire compartment, whether "normal" fire resistant doors are provided or whether ... [more ▼]

The aim of the project is to see whether it makes a difference in term of propagation of smoke to compartments outside the fire compartment, whether "normal" fire resistant doors are provided or whether doors with particular properties related to smoke propagation (Sa or Sm) are provided. Two types of building have been considered: one of horizontal shape (representative of a hotel or a hospital floor) and one of vertical shape (representative of a dxellings building). Different scenario have been considered with respect to the type of doors, the fact that different doors or windons are open or not, the presence of wind... Observed results in different compartment are the thickness of the smoke free layer, the temperature of the smoke layer, the obscurtion or the CO content. [less ▲]

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See detailPropagation of electron and proton shock-induced aurora and the role of the interplanetary magnetic field and solar wind
Meurant, M.; Gérard, Jean-Claude ULg; Blockx, Caroline ULg et al

in Journal of Geophysical Research. Space Physics (2004), 109

Shock-induced aurora observed with satellite-borne ultraviolet imagers shows distinct characteristics from the more common and extensively studied aurora generated during magnetospheric substorms. It is ... [more ▼]

Shock-induced aurora observed with satellite-borne ultraviolet imagers shows distinct characteristics from the more common and extensively studied aurora generated during magnetospheric substorms. It is initiated in the noon sector immediately following dynamic pressure pulses associated with the arrival of enhanced solar wind plasma at the front of the magnetosphere. The auroral brightening rapidly propagates toward the dawn and dusk sectors and may eventually trigger the development of an auroral substorm on the nightside. The FUV imaging system on board the IMAGE satellite has the ability to discriminate between proton and electron precipitation. This feature has been used to study the morphology and dynamics of the electron and proton precipitation following pulse-induced magnetospheric perturbations. A different dynamic is observed for aurora caused by electron and proton precipitation, as well as the important role played by the north-south component of the interplanetary magnetic field. The propagation from the noon to the night sector mainly occurs through the afternoon region for proton precipitation and the morning sector for electron aurora, as expected from azimuthal drift of newly injected plasma. The asymmetry of the precipitation distribution around the noon-midnight axis is more pronounced during negative B[SUB]z[/SUB] periods, when activity is the most important. The magnitude of both the interplanetary magnetic field and the solar wind speed appears well correlated with the precipitated power, by contrast with the solar wind density and the magnitude of the dynamic pressure, which appear to play a minor role. It is suggested that adiabatic compression and plasma waves play an important role on the locations of electron and proton precipitation in the dayside. [less ▲]

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See detailThe propagation processes of the North Anatolian fault and the Messinian Crisis of the Mediterranean
Armijo, R; Meyer, B; Hubert, Aurelia ULg et al

in Journal of Conference (EUG abstracts) (1999, April), 4

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See detailPropagations en réseaux de cours d'eau d'ondes de crues incluant des ressauts
Pirotton, Michel ULg

in Tribune de l'Eau (La) (1995), 49(574), 23-33

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See detailPropédeutique dans l’espèce équine.
Amory, Hélène ULg

Learning material (2011)

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See detailPropellantless rendez-vous of QB50 nanosatellites
Dell'Elce, Lamberto ULg; Kerschen, Gaëtan ULg

in Proceedings of the 63rd IAC (2012)

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See detailPropensity of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), to Develop on Four Potato Plant Varieties
Caparros Megido, Rudy ULg; Brostaux, Yves ULg; Haubruge, Eric ULg et al

in American Journal of Potato Research (2013), 90

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is now considered to be one of the most damaging invasive pests of tomatoes in the world. Tomato is regarded as the main host of T. absoluta ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is now considered to be one of the most damaging invasive pests of tomatoes in the world. Tomato is regarded as the main host of T. absoluta, but the pest can also feed, develop and reproduce on other cultivated Solanaceae, such as potato (Solanum tuberosum L). In the present study, we examined the ability of T. absoluta to develop on four commonly cultivated varieties of potato, under laboratory conditions. The survival rate of T. absoluta did not differ between the five tested host plants (tomato: Solanum lycopersicum cv. Moneymaker; and potato: Solanum tuberosum cv. Spunta, Charlotte, Nicola, and Bintje), but its development time (egg to pupation) was significantly affected. Compared to tomato, development times were longer on Bintje and shorter on Nicola, Charlotte, and Spunta. These results show the high capacity of T. absoluta to develop on potato crops. [less ▲]

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See detailPropeptide-assisted secretion of a psychrophilic alpha-amylase
Feller, Georges ULg

Conference (1997)

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See detailProper Orthogonal Decomposition and Model Reduction of Nonlinear Systems
Kerschen, Gaëtan ULg; Lenaerts, Vincent; Golinval, Jean-Claude ULg

in European Cost F3 Conference on system Identification & Structural Health Monitoring, Madrid, 2000 (2000)

This work deals with the application of the proper orthogonal decomposition (POD) to structural dynamics. On one hand, a physical interpretation of the proper orthogonal modes (POM) is given using the ... [more ▼]

This work deals with the application of the proper orthogonal decomposition (POD) to structural dynamics. On one hand, a physical interpretation of the proper orthogonal modes (POM) is given using the singular value decomposition (SVD). It is shown that the POM converge to the normal modes under some circumstances. On the other hand, the POM are exploited for model reduction purposes. The efficiency of the reduced model for the prediction of the response is tested on a nonlinear beam. The comparison with another reduced model obtained via the normal modes of the linearised system points out that the POM are optimal for the reconstruction of the dynamics of a system. [less ▲]

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See detailProper orthogonal decomposition for model updating of non-linear mechanical systems
Lenaerts, V.; Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in Mechanical Systems & Signal Processing (2001), 15(1)

Proper orthogonal decomposition (POD), also known as Karhunen}Loeve (K}L) decomposition, is emerging as a useful experimental tool in dynamics and vibrations. The POD is a means of extracting spatial ... [more ▼]

Proper orthogonal decomposition (POD), also known as Karhunen}Loeve (K}L) decomposition, is emerging as a useful experimental tool in dynamics and vibrations. The POD is a means of extracting spatial information from a set of time-series data available on a domain. The use of (K}L) transform is of great help in non-linear settings where traditional linear techniques such as modal-testing and power-spectrum analyses cannot be applied. These decomposition can be used as an orthogonal basis for e$cient representation of the ensemble. The POM have been interpreted mainly as empirical system modes and the application of POD to measured displacements of a discrete structure with a known mass matrix leads to an estimation of the normal modes. We investigate the use of the proper orthogonal modes of displacements for the identi"cation of parameters of non-linear dynamical structures with an optimisation procedure based on the di!erence between the experimental and simulated POM. A numerical example of a beam with a local non-linear component will illustrate the method. (C) 2001 Academic Press [less ▲]

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See detailProper Orthogonal Decomposition for Nonlinear Radiative Heat Transfer Problems
Hickey, D.; Masset, Luc ULg; Kerschen, Gaëtan ULg et al

in Proceedings of the ASME International Design Engineering Technical Conferences (2011)

Analysing large scale, nonlinear, multiphysical, dynamical structures, by using mathematical modelling and simulation, e.g. Finite Element Modelling (FEM), can be computationally very expensive ... [more ▼]

Analysing large scale, nonlinear, multiphysical, dynamical structures, by using mathematical modelling and simulation, e.g. Finite Element Modelling (FEM), can be computationally very expensive, especially if the number of degrees-of-freedom is high. This paper develops modal reduction techniques for such nonlinear multiphysical systems. The paper focuses on Proper Orthogonal Decomposition (POD), a multivariate statistical method that obtains a compact representation of a data set by reducing a large number of interdependent variables to a much smaller number of uncorrelated variables. A fully coupled, thermomechanical model consisting of a multilayered, cantilever beam is described and analysed. This linear benchmark is then extended by adding nonlinear radiative heat exchanges between the beam and an enclosing box. The radiative view factors, present in the equations governing the heat fluxes between beam and box elements, are obtained with a raytracing method. A reduction procedure is proposed for this fully coupled nonlinear, multiphysical, thermomechanical system. Two alternative approaches to the reduction are investigated, a monolithic approach incorporating a scaling factor to the equations, and a partitioned approach that treats the individual physical modes separately. The paper builds on previous work presented previously by the authors. The results are given for the RMS error between either approach and the original, full solution. [less ▲]

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See detailProper Orthogonal Decomposition of Unsteady Aerodynamic Flows
Andrianne, Thomas ULg; Ligot, Jerome; Dimitriadis, Grigorios ULg

Report (2009)

This work constitutes the final report for a project funded by the Fonds de la Recherche Scientifique. The objective of the project was to acquire and install Par- tical Image Velocimetry (PIV) hardware ... [more ▼]

This work constitutes the final report for a project funded by the Fonds de la Recherche Scientifique. The objective of the project was to acquire and install Par- tical Image Velocimetry (PIV) hardware in the University of Liege Wind Tunnel facility in order to carry out the Proper Orthogonal Decomposition (POD) of un- steady aerodynamic flows. The characteristics and installation of the PIV system are described in the present report. Furthermore, the application of POD analysis to three different visualized flow cases is detailed. The flow cases were: flow be- hind a circular cylinder and separated flow over a rectangular wing. In all cases, emphasis was given to the combination of unsteadiness caused by both boundary layer separation and movement of the wind tunnel model. It is shown that the de- composition of flowfields that combine these two sources of unsteadiness is possible and informative. [less ▲]

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See detailProper Orthogonal modes for the characterisation of nonlinear dynamic systems
Kerschen, Gaëtan ULg; Lenaerts, Vincent; Golinval, Jean-Claude ULg et al

in Euromech Colloquim on Nonlinear Modes of Vibrating Systems, Frejus, 2004 (2004)

Modal analysis is extensively used for the analysis and design of structures. However, a major concern for structural dynamicists is that its validity is limited to systems showing a linear behaviour. New ... [more ▼]

Modal analysis is extensively used for the analysis and design of structures. However, a major concern for structural dynamicists is that its validity is limited to systems showing a linear behaviour. New developments have thus been proposed in order to tackle nonlinear systems among which the theory based on the nonlinear normal modes is indubitably the most appealing. In this study, a different approach is adopted and the modes extracted from the proper orthogonal decomposition are considered for the characterization of nonlinear systems. [less ▲]

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See detailProper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data
Frankowski, A.; Jancart, Sylvie ULg; Jorissen, A.

in Astronomy and Astrophysics (2007), 464

Context: This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue. <BR />Aims: The comparison of the proper motions constructed from positions spanning a ... [more ▼]

Context: This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue. <BR />Aims: The comparison of the proper motions constructed from positions spanning a short (Hipparcos) or long time (Tycho-2) makes it possible to uncover binaries with periods of the order of or somewhat larger than the short time span (in this case, the 3 yr duration of the Hipparcos mission), since the unrecognised orbital motion will then add to the proper motion. <BR />Methods: A list of candidate proper motion binaries is constructed from a carefully designed χ[SUP]2[/SUP] test evaluating the statistical significance of the difference between the Tycho-2 and Hipparcos proper motions for 103 134 stars in common between the two catalogues (excluding components of visual systems). Since similar lists of proper-motion binaries have already been constructed, the present paper focuses on the evaluation of the detection efficiency of proper-motion binaries, using different kinds of control data (mostly radial velocities). The detection rate for entries from the Ninth Catalogue of Spectroscopic Binary Orbits (S_B^9) is evaluated, as well as for stars like barium stars, which are known to be all binaries, and finally for spectroscopic binaries identified from radial velocity data in the Geneva-Copenhagen survey of F and G dwarfs in the solar neighbourhood. <BR />Results: Proper motion binaries are efficiently detected for systems with parallaxes in excess of ~20 mas, and periods in the range 1000-30 000 d. The shortest periods in this range (1000-2000 d, i.e., once to twice the duration of the Hipparcos mission) may appear only as DMSA/G binaries (accelerated proper motion in the Hipparcos Double and Multiple System Annex). Proper motion binaries detected among S_B[SUP]9[/SUP] systems having periods shorter than about 400 d hint at triple systems, the proper-motion binary involving a component with a longer orbital period. A list of 19 candidate triple systems is provided. Binaries suspected of having low-mass (brown-dwarf-like) companions are listed as well. Among the 37 barium stars with parallaxes larger than 5 mas, only 7 exhibit no evidence for duplicity whatsoever (be it spectroscopic or astrometric). Finally, the fraction of proper-motion binaries shows no significant variation among the various (regular) spectral classes, when due account is taken for the detection biases. Full Table [see full text] is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/464/377 [less ▲]

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See detailPROPERCE. Elegiae. Index verborum, listes de fréquence
Purnelle, Gérald ULg

Book published by Olms Verlag (1997)

Detailed reference viewed: 15 (0 ULg)