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See detailRemarks on Contact and Jacobi Geometry
Bruce, Andrew UL; Grabowska, Katarzyna; Grabowski, Janusz

in Symmetry, Integrability and Geometry: Methods and Applications [=SIGMA] (2017), 13(059), 22

We present an approach to Jacobi and contact geometry that makes many facts, presented in the literature in an overcomplicated way, much more natural and clear. The key concepts are Kirillov manifolds and ... [more ▼]

We present an approach to Jacobi and contact geometry that makes many facts, presented in the literature in an overcomplicated way, much more natural and clear. The key concepts are Kirillov manifolds and linear Kirillov structures, i.e., homogeneous Poisson manifolds and, respectively, homogeneous linear Poisson manifolds. The difference with the existing literature is that the homogeneity of the Poisson structure is related to a principal GL(1,ℝ)-bundle structure on the manifold and not just to a vector field. This allows for working with Jacobi bundle structures on nontrivial line bundles and drastically simplifies the picture of Jacobi and contact geometry. Our results easily reduce to various basic theorems of Jacobi and contact geometry when the principal bundle structure is trivial, while giving new insights into the theory. [less ▲]

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See detailObservation and Control of Anaerobic Digestion Processes for Improved Biogas Production
Chaib Draa, Khadidja UL

Doctoral thesis (2017)

In this thesis, we propose a formal modelling framework for the anaerobic digestion process, where we add more degrees of freedom in the control of biogas production. Indeed, we add two additional control ... [more ▼]

In this thesis, we propose a formal modelling framework for the anaerobic digestion process, where we add more degrees of freedom in the control of biogas production. Indeed, we add two additional control inputs to the standardized AM2 (Acidogenesis Methanogenesis, 2 steps) model, re ecting addition of stimulating substrates which enhance the biogas quality and quantity. Then, we describe how the parameters of the resulted nonlinear model can be identi ed, and we analyse the positiveness and boundedness of its state variables. Based on the derived mathematical model and the analysis results, we design di erent software sensors to overcome the lack of reliable and cheap sensors. Indeed, we present a general class of systems to which the considered process model belongs. Then, we design an LMI-based invariant like observer as well as an LMI-based nonlinear observer of the same form as the generalized Arcak's observer. Furthermore, with the aim to render the observer design more robust to disturbances, we include the H1 criterion in its synthesis. Also, to promote the use of the proposed observers in real applications, we extend the methodology to the discrete time case and to the case of nonlinear systems with nonlinear outputs. For the di erent observers design, we use the di erential mean value theorem which allows the transformation of the nonlinear estimation error to a linear parameter varying system. Then, we use the Lipschitz conditions and the Lyapunov standard function to synthesize the stability conditions in the form of linear matrix inequalities. Finally, we enhance the feasibility of the later conditions by using a judicious reformulation of the Young's inequality. In the thesis, we also deal with the process control where we propose a control strategy to track an admissible reference trajectory planned by the plant operator. Moreover, to account for the partial availability of the state vector measurements, we include an exponential nonlinear observer in the control synthesis. Thus, we design an observer based tracking control scheme. To perform the stability analysis of the closed loop system, composed of the system, the observer and the controller, we use the Barbalat's lemma conjointly with the techniques already mentioned for the observers design. Finally, we propose two different methods to compute the controller and the observer parameters. In the first one, we propose to compute them separately. While, in the second one we compute the parameters simultaneously. [less ▲]

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See detailOperational Excellence Survey
Oberhausen, Christof UL

Speeches/Talks (2017)

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See detailInternationalisierung des Wohnens in Luxemburg – Vom empirischen Fall zum Modell
Becker, Tom UL; Christmann, Nathalie UL

Presentation (2017, June 15)

Aufgrund der sozioökonomischen und räumlichen Entwicklung des Großherzogtums ist der luxemburgische Wohnungsmarkt seit mehr als zwei Jahrzehnten vor allem durch ausgeprägte und dauerhafte Knappheiten und ... [more ▼]

Aufgrund der sozioökonomischen und räumlichen Entwicklung des Großherzogtums ist der luxemburgische Wohnungsmarkt seit mehr als zwei Jahrzehnten vor allem durch ausgeprägte und dauerhafte Knappheiten und hohe Kauf- und Mietpreise gekennzeichnet. Etliche Städte und Metropolregionen in Europa zeigen ähnliche Tendenzen auf. Spezifisch für unseren Fall sind jedoch erstens die geringe Größe des Landes sowie zweitens die fortwährenden wirtschaftlichen und demografischen Dynamiken, sie sich zum Teil in sehr starken grenzüberschreitenden, internationalen und sogar globalen Verflechtungen ausdrücken. Die Relevanz der „Internationalisierung“ des Wohnens in (und um) Luxemburg in all ihren Facetten ist allerdings nicht nur aus politischer und soziokultureller Sicht gegeben. Wegen seiner Besonderheit war der Fall in der Vergangenheit auch immer wieder Gegenstand wissenschaftlicher Untersuchungen. Bis auf einige wenige Ausnahmen waren diese Studien meist quantitativ angelegt und beschränkten sich vor allem auf die durch die sozioökonomischen Entwicklungen verursachten räumlichen Effekte der Internationalisierung des Wohnens. So wurden zwischen seit Mitte der 2000er Jahre z.B. mehrere Studien über Grenzpendlerströme und deren Auswirkungen auf das Wirtschaftswachstum, die Mobilität und das Wohnen in Luxemburg durchgeführt. Auch das Ausmaß und die Beweggründe für den Abzug von im Großherzogtum lebenden luxemburgischen und ausländischen Bürgern in das grenznahe Ausland wurde im Detail erforscht. Der luxemburgische Immobilienmarkt ist durch eine sehr dynamische Entwicklung und einen hohen Grad an Internationalität gekennzeichnet ist. Unser Beitrag zielt hauptsächlich darauf ab, die bisher vorherrschende wissenschaftliche Debatte über die Frage der Internationalisierung des Luxemburger Wohnungsmarktes erneut zu öffnen und sie um den Aspekt der Governance zu erweitern. Auf diese Weise sollen einerseits der Begriff der „Internationalisierung“ mit seinen z.T. sehr unterschiedlichen Wirkungsweisen im Bereich des Wohnens in Luxemburg differenzierter ergründet und andererseits neue Forschungsansätze entwickelt werden. Unsere Aussagen beruhen im Wesentlichen auf der Auswertung von Dokumenten und Sekundärmaterial zum Thema sowie der aktiven Mitwirkung an relevanten Fachdiskussionen zum Thema Wohnen in Luxemburg. [less ▲]

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See detailComparative evaluation of atom mapping algorithms for balanced metabolic reactions: application to Recon 3D
Preciat Gonzalez, German Andres UL; El Assal, Lemmer UL; Noronha, Alberto UL et al

in Journal of Cheminformatics (2017)

The mechanism of each chemical reaction in a metabolic network can be represented as a set of atom mappings, each of which relates an atom in a substrate metabolite to an atom of the same element in a ... [more ▼]

The mechanism of each chemical reaction in a metabolic network can be represented as a set of atom mappings, each of which relates an atom in a substrate metabolite to an atom of the same element in a product metabolite. Genome-scale metabolic network reconstructions typically represent biochemistry at the level of reaction stoichiometry. However, a more detailed representation at the underlying level of atom mappings opens the possibility for a broader range of biological, biomedical and biotechnological applications than with stoichiometry alone. Complete manual acquisition of atom mapping data for a genome-scale metabolic network is a laborious process. However, many algorithms exist to predict atom mappings. How do their predictions compare to each other and to manually curated atom mappings? For more than four thousand metabolic reactions in the latest human metabolic reconstruction, Recon 3D, we compared the atom mappings predicted by six atom mapping algorithms. We also compared these predictions to those obtained by manual curation of atom mappings for over five hundred reactions distributed among all top level Enzyme Commission number classes. Five of the evaluated algorithms had similarly high prediction accuracy of over 91% when compared to manually curated atom mapped reactions. On average, the accuracy of the prediction was highest for reactions catalysed by oxidoreductases and lowest for reactions catalysed by ligases. In addition to prediction accuracy, the algorithms were evaluated on their accessibility, their advanced features, such as the ability to identify equivalent atoms, and their ability to map hydrogen atoms. In addition to prediction accuracy, we found that software accessibility and advanced features were fundamental to the selection of an atom mapping algorithm in practice. [less ▲]

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See detailPoster: Impact of ground truth errors on Wi-Fi localization accuracy
Popleteev, Andrei UL

Poster (2017, June)

This study investigates the impact of small ground truth (GT) errors on indoor positioning systems based on Wi-Fi fingerprinting. The results demonstrate that even centimeter-scale GT deviations cause ... [more ▼]

This study investigates the impact of small ground truth (GT) errors on indoor positioning systems based on Wi-Fi fingerprinting. The results demonstrate that even centimeter-scale GT deviations cause severe degradation of measured localization accuracy. [less ▲]

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See detailArbeiten unter Hitler. NS-Sozialpolitik und Herrschaftspraxis im besetzten Luxemburg 1940-1944
Schoentgen, Marc Mike Claude UL

Doctoral thesis (2017)

Die Arbeit untersucht Grundlagen, Konzeptionen und Auswirkungen der nationalsozialistischen Besatzungsherrschaft in Luxemburg (1940-1944) in den Bereichen der Wirtschafts- und Sozialpolitik ... [more ▼]

Die Arbeit untersucht Grundlagen, Konzeptionen und Auswirkungen der nationalsozialistischen Besatzungsherrschaft in Luxemburg (1940-1944) in den Bereichen der Wirtschafts- und Sozialpolitik. Berücksichtigung findet auch die NS-Volkstums- und Kulturpolitik. Staatliche Maßnahmen führten in der Besatzungszeit dazu, dass während einer relativ langen Phase die Auswirkungen des Krieges auf das Alltags- und Arbeitsleben wenig spürbar waren. Damit trug die Sozialpolitik zu einer politischen und psychologischen Stabilisierung des Regimes bei. Besonders betroffen von der Politik des nationalsozialistischen Gauleiters Gustav Simon waren die Luxemburger Gewerkschaften, die von den Machthabern instrumentalisiert und anschließend liquidiert wurden. An ihre Stelle trat die Deutsche Arbeitsfront, größte Massenorganisation des Regimes, die ihre vielfältigen Aktivitäten in den Bereichen der Sozial-, Wirtschafts-, Freizeit- und Kulturpolitik auch auf Luxemburg ausdehnte. Genauer untersucht wird die Institution des Stillhaltekommissars für das Organisationswesen, der die Gewerkschaften und andere Vereine liquidierte beziehungsweise nazifizierte. Damit wurden die Fundamente der Luxemburger Gesellschaft in Frage gestellt. Die Neuordnungspolitik des Regimes wird u.a. am Beispiel des Industriegebiets im Süden Luxemburgs dargestellt. Im Arbeitermilieu sahen die nationalsozialistischen Machthaber ein Experimentierfeld ihrer Politik. Krieg und Besatzung hatten letztlich auch Auswirkungen auf die großen Industriebetriebe. Gerade hier änderte sich ab der zweiten Hälfte des Krieges durch unterschiedliche Formen der Repression und Zwangsarbeit der Alltag der Menschen. Übergreifend befasst sich die Arbeit auch mit der Luxemburger Kriegsgesellschaft beziehungsweise den unterschiedlichen Reaktionen der Arbeiter und Angestellten auf Verlockung und Zwang. Kapitel: 1. Die NS-Sozialpolitik in Luxemburg 2. Die Luxemburger Gewerkschaften im Krieg. 3. Das Luxemburger Industriegebiet 4. Der Stillhaltekommissar für das Organisationswesen 5. Die Deutsche Arbeitsfront 6. Arbeiten im Krieg [less ▲]

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See detailRehabilitation of People with Psychiatric Disabilities in Sheltered Workshop in Luxembourg: Employment Facilities as a Social Pillar for Vulnerable Groups
Karavdic, Senad UL; Limbach-Reich, Arthur UL

in The 9th International Conference of the Faculty of Education and Rehabilitation Sciences University of Zagreb (2017, May)

People with mental and psychiatric disabilities are globally and historically the most neglected and overlooked group in the matter of experienced social exclusion and discrimination at the labour market ... [more ▼]

People with mental and psychiatric disabilities are globally and historically the most neglected and overlooked group in the matter of experienced social exclusion and discrimination at the labour market. The European Pillar on social rights, recently launched by the European Commission, underlines the importance of equal opportunities and access to the labour market for everyone. In regard to this, fair working conditions and active support to employment should also be provided for people with psychiatric disabilities. Employment for people with psychiatric problems still remains a problematic issue, reaching an unemployment rate of about 90% among the most vulnerable groups with the chronical condition such as psychosis. Insufficient stress resilience, pre-existing scarring effects, socioeconomic vulnerability coupled to constrained mental health literacy among employers are some of the main barriers that people with psychiatric disabilities may face as they move towards and into their work. In addition, the fluctuating mental state of a person linked to specificity and heterogeneous evolutions of mental illness has led to rethinking classical models of support, challenging new concepts used until now for physical or sensory disabilities. Initially created to welcome people out of psychiatry, emerging from the acute phase of the illness towards the resocialisation and professional adjustment, sheltered workshop for persons with psychiatric disabilities nowadays promotes new environment, such as supported & therapeutic, i.e. proximity-orientated and individually adapted to the abilities of the person. In order to enhance inclusion by sustainable employment, services have to be proactive, provide gateways to employment, foster psychosocial recovery of the people during their stay and assist them in managing their mental health problems after their placement. Our presentation stresses the Luxembourgish ATP-Model which offers an individual service for people with psychiatric problems; to cope with labour market related challenges and in-situ job coaching perspectives. However, this requires rethinking the traditional assignment of social work. [less ▲]

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See detailClosing or Persisting Gender Gap? A Cohort Analysis of Education and Wages in the United States and Europe
Chauvel, Louis UL; Hartung, Anne UL; Bar-Haim, Eyal UL

in Population Association of America - PAA Annual Meeting 2017 (2017)

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See detailStructure of Hecke algebras of modular forms modulo $p$
Deo, Shaunak UL

in Algebra & Number Theory (2017), 11(1), 1-38

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See detailLe droit de rétention de l’avocat
Menetrey, Séverine UL

in JurisNews – Arbitrage et Procédure Civile (2017)

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See detailElectoral Violence in Putin's Russia: Modern authoritarianism in practice
Mochtak, Michal UL; Holzer, Jan

in Studies of Transition States and Societies (2017), 9(1), 35-52

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See detailL’exécution des sentences arbitrales au Luxembourg entre pragmatisme et efficacité
Menetrey, Séverine UL

in JurisNews – Arbitrage et Procédure Civile (2017)

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See detailLa concentration des moyens : quel positionnement pour le droit luxembourgeois ?
Menetrey, Séverine UL

in Journal des Tribunaux Luxembourg (2017)

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