Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
See detailLie antialgebras
Kreusch, Marie ULg

Conference (2011, June 20)

Lie antialgebras which is a $\Z_2$-graded commutative algebra (but not associative) was introduced in 2007 by Valentin Ovsienko. This notion takes place in the superspaces theory studied since years in ... [more ▼]

Lie antialgebras which is a $\Z_2$-graded commutative algebra (but not associative) was introduced in 2007 by Valentin Ovsienko. This notion takes place in the superspaces theory studied since years in geometry. This algebra was discovered in the context of symplectic geometry. In a way, Lie antialgebras unify in a special meaning associative and commutative algebras with Lie algebras. Since this is quite a new subject a lot of things have to be done in the understanding of this structure. At first, I am going to explain the notion of superspaces and in particular the one of Lie superalgebras and give some important examples. After I am going to introduce the topic of Lie antialgebras and also give some examples. And finally I am going to give a links between them (Lie antilagebra and Lie superalgebra). If I have time, I will probably speak a bit about extensions and relations with 2-cocycles in the cohomology theory. That's what I am interested in for the moment. [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
See detailLie antialgebras
Kreusch, Marie ULg

Conference (2011, June 28)

Lie antialgebras which is a $\Z_2$-graded commutative algebra (but not associative) was introduced in 2007 by Valentin Ovsienko. This notion takes place in the superspaces theory studied since years in ... [more ▼]

Lie antialgebras which is a $\Z_2$-graded commutative algebra (but not associative) was introduced in 2007 by Valentin Ovsienko. This notion takes place in the superspaces theory studied since years in geometry. This algebra was discovered in the context of symplectic geometry. In a way, Lie antialgebras unify in a special meaning associative and commutative algebras. Since this is quite a new subject a lot of things have to be done in the understanding of this structure. At first, I am going to explain the notion of superspaces. Then I will speak about the origins of this structure and present what has already been discovered about this new 'type' of algebra (universal algebra, representations, modules, relation to superalgebra,...). After, I am going to give some important examples of Lie antialgebras related to some known structures. Finally, I am going to present what I am searching for the moment and the questions that I am trying to answer. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
See detailLie group formalisms in flexible multibody dynamics
Bruls, Olivier ULg

Conference (2013, September)

This course presents a recently-developed Lie group approach for the analysis of flexible multibody systems with large rotations and kinematic constraints in a parameterization-free setting. More ... [more ▼]

This course presents a recently-developed Lie group approach for the analysis of flexible multibody systems with large rotations and kinematic constraints in a parameterization-free setting. More precisely, the equations of motion are formulated as differential-algebraic equations (DAE) on a matrix Lie group and are then solved using a Lie group time integration method. Based on a nonlinear finite element approach, the lecture shows how the kinematics of a flexible multibody system, including the description of nodal frames, velocity fields, constraints, and flexible bodies, are described in the Lie group framework. The general structure of the equations of motion are derived from the Hamilton principle in a general and unifying approach. A Lie group generalized-alpha time integration scheme is proposed for DAEs on a Lie group and practical implementation issues are discussed. Finally, semi-analytical algorithms for sensitivity analysis on a Lie group are proposed for optimization purpose. The theoretical concepts and the numerical properties of the algorithms are illustrated with a number of examples. [less ▲]

Detailed reference viewed: 96 (17 ULg)
Full Text
Peer Reviewed
See detailLie group generalized-alpha time integration of constrained flexible multibody systems
Bruls, Olivier ULg; Cardona, Alberto; Arnold, Martin

in Mechanism & Machine Theory (2012), 48

This paper studies a Lie group extension of the generalized-alpha time integration method for the simulation of flexible multibody systems. The equations of motion are formulated as an index-3 ... [more ▼]

This paper studies a Lie group extension of the generalized-alpha time integration method for the simulation of flexible multibody systems. The equations of motion are formulated as an index-3 differential-algebraic equation (DAE) on a Lie group, with the advantage that rotation variables can be taken into account without the need of introducing any parameterization. The proposed integrator is designed to solve this equation directly on the Lie group without index reduction. The convergence of the method for DAEs is studied in detail and global second-order accuracy is proven for all solution components, i.e. for nodal translations, rotations and Lagrange multipliers. The convergence properties are confirmed by three benchmarks of rigid and flexible systems with large rotation amplitudes. The Lie group method is compared with a more classical updated Lagrangian method which is also formulated in a Lie group setting. The remarkable simplicity of the new algorithm opens interesting perspectives for real-time applications, model-based control and optimization of multibody systems. [less ▲]

Detailed reference viewed: 187 (26 ULg)
Full Text
See detailLie group integrators for the numerical solution of DAE’s in flexible multibody dynamics
Cardona, Alberto; Bruls, Olivier ULg; Arnold, Martin

Conference (2010, November)

Detailed reference viewed: 74 (1 ULg)
See detailLie group vs. classical time integrators in multibody dynamics: Formulations and numerical benchmarks
Bruls, Olivier ULg; Cardona, Alberto

Conference (2009, September)

The dynamics of flexible multibody systems with large rotations is often described using large sets of index-3 differential-algebraic equations. In this context, the Lie group structure of the dynamic ... [more ▼]

The dynamics of flexible multibody systems with large rotations is often described using large sets of index-3 differential-algebraic equations. In this context, the Lie group structure of the dynamic system may be exploited in order to provide an elegant solution to the rotation parameterization problem. The talk discusses an original Lie-group extension of the classical generalized-alpha method, which can be used to solve index-3 differential-algebraic equations in multibody dynamics. Second-order accuracy is demonstrated at least in the unconstrained case and the performance is illustrated on several critical benchmarks with high rotational speeds. The remarkable simplicity of the new algorithms opens some interesting perspectives for real-time applications, model-based control and optimization of multibody systems. [less ▲]

Detailed reference viewed: 57 (2 ULg)
Full Text
Peer Reviewed
See detailLiebe und Tod in sommerlichen Gärten Erzählungen von Eduard von Keyserling
Pontzen, Alexandra ULg

in Literaturkritik.de (2005)

Detailed reference viewed: 17 (1 ULg)
See detailLiège
George, Philippe ULg

in Dictionnaire d’Histoire de l’art du Moyen Age occidental (2009)

Detailed reference viewed: 25 (9 ULg)
See detailLiege - Nantes: historical scale models acquisition and data modeling
Carré, Cyril ULg

Conference (2014, December 04)

Detailed reference viewed: 27 (4 ULg)
See detailLiège 1866-1991 : Mutations d’un espace urbain
Frankignoulle, Pierre ULg

Article for general public (1991)

Detailed reference viewed: 86 (14 ULg)
Full Text
See detailLiège 2016 : congrès mondial de la Fédération Internationale des Professeurs de Français
Defays, Jean-Marc ULg

in Le Français dans le mille : Revue de l’Association Belge des Professeurs de Français (2014), 242

Detailed reference viewed: 37 (2 ULg)
Full Text
See detailLiège 2017: Connectez-vous
Brandt, Céline ULg

Article for general public (2012)

Le comité de Liège Expo 2017 a pris le parti de faire de la connectivité sa thématique phare: 4 scientifiques s'expriment au sujet de la connectivité.

Detailed reference viewed: 35 (7 ULg)
See detailLiège : site - évolution récente et perspectives…
Merenne-Schoumaker, Bernadette ULg

in De Saint-Lambert… au Pays de Liège, De septembre 705 à septembre 2005 (2005)

Courte présentation grand public sur le site de Liège, son évolution depuis 1950 et ses perspectives pour le futur

Detailed reference viewed: 18 (1 ULg)
See detailLiège : Territoires, Economie et Société (1960-2008)
Merenne-Schoumaker, Bernadette ULg

in Demoulin, Bruno (Ed.) Liège et le Palais des Princes-Evêques (2008)

Pour traduire la diversité des territoires, celle des hommes qui y vivent et des activités qui s’y sont développées, nous avons choisi une démarche par systèmes emboîtés depuis le quartier du palais ... [more ▼]

Pour traduire la diversité des territoires, celle des hommes qui y vivent et des activités qui s’y sont développées, nous avons choisi une démarche par systèmes emboîtés depuis le quartier du palais jusqu’à l’Euregio Meuse-Rhin (EMR). Ce cheminement, ponctué de nombreuses cartes, devrait permettre de découvrir les multiples facettes des mondes liégeois. [less ▲]

Detailed reference viewed: 26 (5 ULg)
Full Text
See detailLiège à la veille de 1914: entre France et Allemagne...
Lanneau, Catherine ULg

in Maréchal, Christine; Schloss, Claudine (Eds.) 1914-1918: vivre la guerre à Liège et en Wallonie (2014)

Detailed reference viewed: 98 (59 ULg)
Full Text
Peer Reviewed
See detailThe Liege Acromegaly Survey (LAS) : A new software tool for the study of acromegaly
PETROSSIANS, Patrick ULg; Tichomirowa, M; Stevenaert, Achille ULg et al

in Annales d'Endocrinologie (2012), 73

Detailed reference viewed: 64 (11 ULg)
See detailLiège Acromegaly Survey (LAS): First snapshot
Petrossians, Patrick ULg; Chanson, P.; Sievers, C. et al

in European Neuroendocrine Association - Liège, 22-25 septembre 2010 (2010, September)

Detailed reference viewed: 37 (3 ULg)
See detailThe Liège Acromegaly Survey
Tichomirova, M.; Daly, Adrian ULg; Petrossians, Patrick ULg et al

in 23ème Congrès de la Société Française d'Endocrinologie - Abstract book (2006)

Detailed reference viewed: 11 (2 ULg)
See detailLiège Acromegaly Survey: Data mining in clinical research, or how to seek information vs data
Petrossians, Patrick ULg; Beckers, Albert ULg

in European Neuroendocrine Association - Liège, 22-25 septembre 2010 (2010, September)

Detailed reference viewed: 37 (3 ULg)