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See detailDiscrete optimization
Louveaux, Quentin ULiege

Poster (2005, September)

Have you ever wondered what is the shortest route to join the office? What is the best way to plan a trip through several cities? You have maybe already played with magical squares? Then you have met one ... [more ▼]

Have you ever wondered what is the shortest route to join the office? What is the best way to plan a trip through several cities? You have maybe already played with magical squares? Then you have met one of the nu- merous instances of discrete optimization. Discrete optimization is a field of mathematics which deals with any problem where parts of the solutions cannot be divided or fractional. And as one may guess, this is the case in many real-life problems. This poster is divided in three main topics. The first part focuses on formulating those problems. We will start from one of the industrial appli- cations and show how we can model it as a mathematical problem. In the second part we sketch the main tools and algorithms used to tackle those problems. In particular we point out the fact that requiring integrality leads to extremely hard problems to solve. We show that despite this fact, we are able to solve problems of substantial size. However there remain some problems that are hard to solve using the state-of-the-art techniques. In the third part we indicate what are the chal- lenges of the field. In particular we will give an overview of the research car- ried out in the universities supported by the Marie-Curie network ADONET. [less ▲]

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See detailA discrete population of squamocolumnar junction cells implicated in the pathogenesis of cervical cancer.
Herfs, Michael ULiege; Yamamoto, Yusuke; Laury, Anna et al

in Proceedings of the National Academy of Sciences of the United States of America (2012), 109(26), 10516-21

Infection by carcinogenic human papillomaviruses (HPV) results in precancers [cervical intraepithelial neoplasia (CIN)] and cancers near the ectoendocervical squamocolumnar (SC) junction of the cervix ... [more ▼]

Infection by carcinogenic human papillomaviruses (HPV) results in precancers [cervical intraepithelial neoplasia (CIN)] and cancers near the ectoendocervical squamocolumnar (SC) junction of the cervix. However, the specific cells targeted by HPV have not been identified and the cellular origin of cervical cancer remains elusive. In this study, we uncovered a discrete population of SC junctional cells with unique morphology and gene-expression profile. We also demonstrated that the selected junctional biomarkers were expressed by a high percentage of high-grade CIN and cervical cancers associated with carcinogenic HPVs but rarely in ectocervical/transformation zone CINs or those associated with noncarcinogenic HPVs. That the original SC junction immunophenotype was not regenerated at new SC junctions following excision, not induced by expression of viral oncoproteins in foreskin keratinocytes, and not seen in HPV-related precursors of the vagina, vulva, and penis further support the notion that junctional cells are the source of cervical cancer. Taken together, our findings suggest that carcinogenic HPV-related CINs and cervical cancers are linked to a small, discrete cell population that localizes to the SC junction of the cervix, expresses a unique gene expression signature, and is not regenerated after excision. The findings in this study uncover a potential target for cervical cancer prevention, provide insight into the risk assessment of cervical lesions, and establish a model for elucidating the pathway to cervical cancer following carcinogenic HPV infection. [less ▲]

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See detailA Discrete Sequence Associated with Mixed Finite Elements and its Gauge Condition for Vector Potentials
Dular, Patrick ULiege; Nicolet, André; Genon, André et al

in IEEE Transactions on Magnetics (1995), 31(3), 1356-1359

A sequence of finite element spaces built on tetrahedra, hexahedra and prisms, is presented, and a gauge condition for vector potentials is shown to be well defined in these spaces. Results are presented ... [more ▼]

A sequence of finite element spaces built on tetrahedra, hexahedra and prisms, is presented, and a gauge condition for vector potentials is shown to be well defined in these spaces. Results are presented for a modified vector potential formulation for 3D eddy current problems. [less ▲]

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See detailDiscrete symmetries in the three-Higgs-doublet model
Ivanov, Igor ULiege; Vdovin, Evgeny

in Physical Review. D : Particles and Fields (2012), 86(9), 0950305

N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a ... [more ▼]

N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a pivotal role in shaping the phenomenology of the model, and various symmetry groups have been studied so far. However, in spite of all efforts, the classification of finite Higgs-family symmetry groups realizable in NHDM for any N>2 is still missing. Here, we solve this problem for the three-Higgs-doublet model by making use of Burnside’s theorem and other results from pure finite group theory which are rarely exploited in physics. Our method and results can also be used beyond high-energy physics, for example, in the study of possible symmetries in three-band superconductors. [less ▲]

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See detailDiscrete Valued Optimal Design Problems
Fleury, Claude ULiege

in Bendsoe, Martin P.; Mota Soares, Carlos A. (Eds.) Topology design of structures: Proceedings of the NATO Advanced Workshop, Sesimbra, Portugal, June 20-26, 1992 (1992)

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See detailDiscrete Vortex Simulations of the torsional flutter oscillations of a 4:1 rectangular cylinder
Andrianne, Thomas ULiege; Dimitriadis, Grigorios ULiege

in Proceedings of the 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference (2012, April 24)

This work presents aeroelastic simulations of a 2D bluff-body around its pitching degree of freedom. The numerical tool consists in an aerodynamic solver based on the Discrete Vortex Method (DVM), coupled ... [more ▼]

This work presents aeroelastic simulations of a 2D bluff-body around its pitching degree of freedom. The numerical tool consists in an aerodynamic solver based on the Discrete Vortex Method (DVM), coupled with a linear structural model. The shape of the bluff-body is a sharp edged rectangular cylinder with a side ratio equal to 4. The numerical results are compared to the experimental measurements recently obtained by the authors.8 The validation is carried out in three steps: first the frequency content of the flow-field in the wake of the static body is investigated. Then the simulated unsteady flow-field around the imposed pitching motion of the body is compared to experimental flow visualizations. This comparison is performed using Proper Orthogonal Decomposition (POD). Finally, the simulation of the global aeroelastic behaviour, based on the coupling of the DVM code to the structural model of the pitching degree of freedom is carried out and the results are compared to measured aeroelastic responses.. Very good agreements are found between numerical and experimental results, demonstrating the capabilities of the numerical tool to simulate complex unsteady aerodynamics around an oscillating bluff-body. [less ▲]

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See detailDiscrete-time synchronization on the N-torus
Sarlette, Alain ULiege; Sepulchre, Rodolphe ULiege; Leonard, Naomi

in Proceedings of the 17th MTNS Symposium, Kyoto 2006 (2006, August)

In this paper, we study the behavior of a discrete-time network of N agents, each evolving on the circle. The global convergence analysis on the N-torus is a distinctive feature of the present work with ... [more ▼]

In this paper, we study the behavior of a discrete-time network of N agents, each evolving on the circle. The global convergence analysis on the N-torus is a distinctive feature of the present work with respect to previous synchronization results that have focused on convergence in the Euclidean space (R^n)^N. We address the question from a control perspective, but make several connections with existing models, including the Hopfield network, the Vicsek model and the (continuous-time) Kuramoto model. We propose two different distributed algorithms. The first one achieves convergence to equilibria in shape space that are the local extrema of a potential U_L built on the graph Laplacian associated to a fixed, undirected interconnection topology; it can be implemented with sensor-based interaction only, since each agent just relies on the relative position of its neighbors. The second one achieves synchronization under varying and/or directed communication topology using local estimates of a consensus variable that are communicated between interacting agents. Both algorithms are based on the notion of centroid and can be interpreted as descent algorithms. The proposed approach can be extended to other embedded compact manifolds. [less ▲]

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See detailDiscrete-time synchronization on the N-torus
Sarlette, Alain ULiege; Sepulchre, Rodolphe ULiege

Conference (2006, March)

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See detailThe Discretionary Use of Strasbourg Jurisprudence by the International Criminal Court
Deprez, Christophe ULiege

Conference (2014, June 13)

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains ... [more ▼]

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains unclear what the authority of such external jurisprudence is vis-à-vis the international criminal judge. While it is virtually undisputed that human rights law, in general terms, is applicable to proceedings before the ICC, many scholars tend to adopt a much nuanced approach to the authority of human rights case law in particular. This paper aims to shed further light on the issue by addressing the question whether ICC judges have used Strasbourg jurisprudence in a consistent manner, in particular as regards the authority which they decided to vest the latter with. It demonstrates that ICC Chambers have relied on European human rights practice, alternatively, as a mere source of inspiration, as binding interpretation, as a corpus having ambivalent authority, or as a source whose legal value it simply left unspecified. This leads us to conclude that, on the whole, the ICC has been mostly inconsistent regarding the value of ECtHR case law in the context of international criminal proceedings. Such inconsistency, we argue, amounts to a discretionary use of Strasbourg jurisprudence that further reinforces the Court's paradoxical position as the ultimate authority for defining the boundaries of its own human rights constraint. [less ▲]

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See detailDiscretization of Sources of Integral Operators
Tarhasaari, T.; Kettunen, L.; Geuzaine, Christophe ULiege

in IEEE Transactions on Magnetics (2000), 36(4), 659--662

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See detailDiscretization of Sources of Integral Operators
Tarhasaari, T.; Kettunen, L.; Geuzaine, Christophe ULiege

in Proceedings of the 12th COMPUMAG Conference on the Computation of Electromagnetic Fields (1999)

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See detailDiscretization of stress fields in the finite element method
Fraeijs de Veubeke, Baudouin ULiege; Millard, A.

Report (1976)

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See detailDiscretization of the divergence formulation of the bed slope term in the shallow-water equations and consequences in terms of energy balance
Bruwier, Martin ULiege; Archambeau, Pierre ULiege; Erpicum, Sébastien ULiege et al

in Applied Mathematical Modelling (2016), 40(17-18), 75327544

In this research, the influence on energy balance of the discretization scheme of the divergence formulation of the bed slope term in the shallow-water equations is analysed theoretically (for a single ... [more ▼]

In this research, the influence on energy balance of the discretization scheme of the divergence formulation of the bed slope term in the shallow-water equations is analysed theoretically (for a single topographic step) and based on two numerical tests. Different values of the main parameter controlling the discretization scheme of the divergence formulation are analysed to identify the formulation which minimizes the energy variation resulting from the discretization. For a wide range of ambient Froude numbers and relative step heights, the theoretical value of the control parameter minimizing the energy variation falls within a very narrow range, which can reasonably be approximated by a single “optimal” value. This is a result of high practical relevance for the design of accurate numerical schemes, as confirmed by the results of the numerical tests. [less ▲]

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See detailDiscretization Schemes for Hybrid Methods
Geuzaine, Christophe ULiege; Tarhasaari, T.; Kettunen, L. et al

in IEEE Transactions on Magnetics (2001), 37(5), 3112--3115

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See detailDiscrets et méconnus...les reptiles
Graitson, Eric ULiege

Book published by Service public de Wallonie (2011)

"En Wallonie, sept espèces de reptiles composent le « petit peuple des broussailles ». Discrets et silencieux, ils passent bien souvent inaperçus. Ils sont pourtant bien là sous une pierre, tapis dans la ... [more ▼]

"En Wallonie, sept espèces de reptiles composent le « petit peuple des broussailles ». Discrets et silencieux, ils passent bien souvent inaperçus. Ils sont pourtant bien là sous une pierre, tapis dans la végétation dense, à l’intérieur des fissures d’un muret ou sous un tas de compost, cherchant la température idéale a leur survie ou simplement un abri pour fuir leurs prédateurs." Après une présentation des différentes espèces de reptiles indigènes présentes en Wallonie, le livre aborde les causes de régression de ces animaux et les mesures de protection applicables par le monde agricole. Plusieurs exemples d'aménagements réalisés en faveur des reptiles en milieu agricole sont présentés à la fin de l'ouvrage. [less ▲]

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See detailDiscriminant analysis based on multivariate response curves: a descriptive approach to dynamic allocation.
Albert, Adelin ULiege

in Statistics in Medicine (1983), 2(1), 95-106

We examine the problem of discriminating between two groups in the context of multivariate response curves observed over a specified time interval. We propose a descriptive solution for the case where one ... [more ▼]

We examine the problem of discriminating between two groups in the context of multivariate response curves observed over a specified time interval. We propose a descriptive solution for the case where one can determine the response curves by linear interpolation between successive observations. Unlike most previously reported methods that use only the current multivariate observation, our approach accounts for the history of the process. Moreover the method has the potential advantage of being applicable dynamically, as one observes the multivariate response curve. Finally, the method demonstrates simplicity and flexibility, two important features for successful, routine, clinical application. [less ▲]

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See detailDiscriminant BOLD Activation Patterns during Mental Imagery in Parkinson’s Disease
Schrouff, Jessica ULiege; Cremers, Julien ULiege; D'Ostilio, Kevin ULiege et al

in Proceedings of MLINI 2012 (2012, December 07)

Using machine learning based models in clinical applications has become current practice and can prove useful to provide information at the subject’s level, such as predicting an (early) diagnosis or ... [more ▼]

Using machine learning based models in clinical applications has become current practice and can prove useful to provide information at the subject’s level, such as predicting an (early) diagnosis or monitoring the evolution of a disease. However, the performance of these models depends on the choice of a biomarker to detect the presence or absence of a disease. Choosing a biomarker is not straightforward, especially in the case of Parkinson’s disease when compared to healthy subjects. In the present work, we investigated the mental imagery of gait as a biomarker of Parkinson’s disease and showed that the signal in the mesencephalic locomotor region during the mental imagery of gait at a comfortable pace can discriminate significantly between idiopathic Parkinson’s disease patients and healthy subjects. Although there is room for improvement, the results of this preliminary study are promising. [less ▲]

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See detailDiscriminating between overshooting and rotational mixing in massive stars: any help from asteroseismology?
Miglio, Andrea ULiege; Montalban Iglesias, Josefa ULiege; Eggenberger, P. et al

in Communications in Asteroseismology (2009, July 01), 158

Chemical turbulent mixing induced by rotation can affect the internal distribution of μ near the energy-generating core of main-sequence stars, having an effect on the evolutionary tracks similar to that ... [more ▼]

Chemical turbulent mixing induced by rotation can affect the internal distribution of μ near the energy-generating core of main-sequence stars, having an effect on the evolutionary tracks similar to that of overshooting. However, this mixing also leads to a smoother chemical composition profile near the edge of the convective core, which is reflected in the behavior of the buoyancy frequency and, therefore, in the frequencies of gravity modes. We show that for rotational velocities typical of main-sequence B-type pulsating stars, the signature of a rotationally induced mixing significantly perturbs the spectrum of gravity modes and mixed modes, and can be distinguished from that of overshooting. The cases of high-order gravity modes in Slowly Pulsating B stars and of low-order g modes and mixed modes in β Cephei stars are discussed. [less ▲]

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See detailDiscriminating net ecosystem exchange between different vegetation plots in a heterogeneous forest
Aubinet, Marc ULiege; Heinesch, Bernard ULiege; Perrin, Dominique ULiege et al

in Agricultural and Forest Meteorology (2005), 132(3-4), 315-328

Detailed reference viewed: 16 (2 ULiège)