![]() ; Salnikov, Vladimir ![]() in Journal of High Energy Physics (2014) We show that in the context of two-dimensional sigma models minimal coupling of an ordinary rigid symmetry Lie algebra g leads naturally to the appearance of the “generalized tangent bundle” TM ≡ T M ⊕ T ... [more ▼] We show that in the context of two-dimensional sigma models minimal coupling of an ordinary rigid symmetry Lie algebra g leads naturally to the appearance of the “generalized tangent bundle” TM ≡ T M ⊕ T ∗ M by means of composite fields. Gauge transformations of the composite fields follow the Courant bracket, closing upon the choice of a Dirac structure D ⊂ TM (or, more generally, the choide of a “small Dirac-Rinehart sheaf” D), in which the fields as well as the symmetry parameters are to take values. In these new variables, the gauge theory takes the form of a (non-topological) Dirac sigma model, which is applicable in a more general context and proves to be universal in two space-time dimensions: a gauging of g of a standard sigma model with Wess-Zumino term exists, iff there is a prolongation of the rigid symmetry to a Lie algebroid morphism from the action Lie algebroid M × g → M into D → M (or the algebraic analogue of the morphism in the case of D). The gauged sigma model results from a pullback by this morphism from the Dirac sigma model, which proves to be universal in two-spacetime dimensions in this sense. [less ▲] Detailed reference viewed: 114 (2 UL)![]() ; Bordas, Stéphane ![]() Learning material (2016) Detailed reference viewed: 168 (4 UL)![]() Ahmad, Rafiq ![]() ![]() Scientific Conference (2014, September 12) Multi-axis machines are known for their precise production of complex parts, where multi-tool are working in the same area or static workpiece support or clamping parts, may cause collision problems. It ... [more ▼] Multi-axis machines are known for their precise production of complex parts, where multi-tool are working in the same area or static workpiece support or clamping parts, may cause collision problems. It is therefore necessary to identify potential collision risks and avoid them in an efficient way, which may cause production stops and machinery damage. This research study has been focusing on safe non-functional (rapid) tool-path generation for multi-axis milling machine, where no efficient automatic collision avoidance solution exists (in the literature). A 3D Time of Flight (TOF) camera attached into the machine will be able to sense any unwanted situation in the manufacturing environment and provide rapid and automatic solution to detect and avoid collisions for safe tool movements during production. In the presence of obstacles, the proposed approach will provide decisions regarding tool-path correction and improvement automatically. The proposed algorithm based on 3D vision concept is also able to take into account unknown obstacle shape, size during production but dynamic aspects of the scene will be treated in future. The concept presented take into account the 3D information from the scene for traversal safe tool-paths generation for a static environment as an initial application, which will be adapted to more complex real machining scenarios by integrating it with STEP-NC technology in future. [less ▲] Detailed reference viewed: 219 (6 UL)![]() Yoo, Hwajong ![]() Presentation (2013, August 28) We present the multiplicity one theorem for Eisenstein maximal ideals. Detailed reference viewed: 93 (0 UL)![]() Bloch, Natalie ![]() Speeches/Talks (2018) Detailed reference viewed: 90 (4 UL)![]() Sischka, Philipp ![]() ![]() E-print/Working paper (2017) Der Survey zu dem „Quality of Work Index Luxembourg“ (QoW), der von der Universität Luxemburg und der luxemburgischen Chambre des Salariés entwickelt wurde (Steffgen, Kohl, 2013; Sischka, Steffgen, 2015 ... [more ▼] Der Survey zu dem „Quality of Work Index Luxembourg“ (QoW), der von der Universität Luxemburg und der luxemburgischen Chambre des Salariés entwickelt wurde (Steffgen, Kohl, 2013; Sischka, Steffgen, 2015, 2016), wurde 2016 bereits zum vierten Mal mittels einer telefonischen Befragung durchgeführt. Ziel des Index ist es, die erlebte Arbeitssituation und -qualität luxemburgischer Arbeitnehmer zu erfassen. Der vorliegende Bericht dokumentiert die psychometrische Testung der Güte des aktuellen Erhebungsinstruments. Dazu erfolgt zunächst eine Beschreibung der für die Skalen genutzten Items, die Überprüfung der internen Konsistenz der jeweiligen Skala mittels verschiedener Reliabilitätsstatistiken (Cronbach’s Alpha, Korrelationsanalysen der Items) sowie Koeffizienten zur Beschreibung der Skalenverteilung. Explorative und konfirmatorische Faktorenanalysen dienen dazu, zu testen, ob die Items auf den a priori festgelegten Faktoren laden und ob sich die unterstellte Faktorenstruktur auch in den Daten zeigt. Außerdem werden die Zusammenhänge der Skalen mittels Korrelationsanalysen überprüft. Die QoW-Skalen werden außerdem auf verschiedene Well-Being-Skalen regressiert, um deren Relevanz für den QoW-Index zu prüfen. Da der QoW Survey teilweise als Panelbefragung durchgeführt wird, wird außerdem geklärt, ob es hinsichtlich demographischer Eigenschaften der Befragten, hinsichtlich der QoW-Skalen oder hinsichtlich verschiedener Well-Being-Maße zu systematischen Ausfällen seit der letzten Welle gekommen ist. Ebenso werden einige Längsschnitt-Regressionsanalysen gerechnet, um zu überprüfen, ob einige Arbeitsbedingungen längerfristige Effekte auf das Well-Being der Arbeitnehmer aufweisen. Abschließend wird das gesamte Erhebungsinstrument zusammenfassend diskutiert und Empfehlungen bezüglich der weiteren Entwicklung der Skalen gegeben. [less ▲] Detailed reference viewed: 99 (3 UL)![]() ; Berg, Dominik ![]() ![]() in Journal of Electroanalytical Chemistry (2010), 646(1-2), 52-59 Detailed reference viewed: 158 (1 UL)![]() Stankiewicz, Jacek ![]() in Tectonophysics (2013), 609 According to some previous studies, Archean continental crust is, on global average, apparently thinner than Proterozoic crust. Subsequently, the validity of this statement has been questioned. To provide ... [more ▼] According to some previous studies, Archean continental crust is, on global average, apparently thinner than Proterozoic crust. Subsequently, the validity of this statement has been questioned. To provide an additional perspective on this issue, we present analyses of Moho signatures derived from recent seismic data along swaths 2000 km in length across southern Africa and its flanking ocean. The imaged crust has a near continuous age range between ca. 0.1 and 3.7 billion years, and the seismic data allow direct comparison of Moho depths between adjacent Archean, Proterozoic and Phanerozoic crust. We find no simple secular change in depth to Moho over this time period. In contrast, there is significant variation in depth to Moho beneath both Archean and Proterozoic crust; Archean crust of southern Africa displays as much crustal diversity in thickness as the adjacent Proterozoic crust. The Moho beneath all crustal provinces that we have analysed has been severely altered by tectono-metamorphic and igneous processes, in many cases more than once, and cannot provide unequivocal data for geodynamic models dealing with secular changes in continental crust formation. These results and conclusions are similar to those documented along ca. 2000 km swaths across the Canadian Shield recorded by Lithoprobe. Tying the age and character of the Precambrian crust of southern Africa to their depth diversities is clearly related to manifold processes of tectono-thermal ‘surgery’ subsequent to their origin, the details of which are still to be resolved, as they are in most Precambrian terranes. Reconstructing pristine Moho of the early Earth therefore remains a formidable challenge. In South Africa, better knowledge of ‘fossilised’ Archean crustal sections ‘turned on-edge’, such as at the Vredefort impact crater (for the continental crust), and from the Barberton greenstone belt (for oceanic crust) is needed to characterize potential pristine Archean Moho transitions. [less ▲] Detailed reference viewed: 16 (0 UL)![]() Brüll, Christoph ![]() Article for general public (2022) Le 30 août 1992, la commune de Dudelange commémore les cinquante ans du déclenchement du recrutement forcé au Luxembourg. Dès le 31 août 1942, une vague de grèves avait gagné le Luxembourg. Ce signe de ... [more ▼] Le 30 août 1992, la commune de Dudelange commémore les cinquante ans du déclenchement du recrutement forcé au Luxembourg. Dès le 31 août 1942, une vague de grèves avait gagné le Luxembourg. Ce signe de protestation contre la mesure de l’Occupant nazi est devenu le symbole d’un pays résistant. [less ▲] Detailed reference viewed: 40 (4 UL)![]() Kolnberger, Thomas ![]() in Historische Sozialkunde: Geschichte - Fachdidaktik - Politische Bildung (2006), 3 Detailed reference viewed: 113 (6 UL)![]() Brüll, Christoph ![]() Article for general public (2022) Le 20 juin 1967, l’homme d’État luxembourgeois, Joseph Bech reçoit le prix Robert Schuman de l’université de Bonn pour honorer son engagement européen. Dans son discours de remerciement, il rappelle les ... [more ▼] Le 20 juin 1967, l’homme d’État luxembourgeois, Joseph Bech reçoit le prix Robert Schuman de l’université de Bonn pour honorer son engagement européen. Dans son discours de remerciement, il rappelle les acquis du projet européen, mais précise que tout reste à faire. La cérémonie a été suivie d'une rencontre avec des étudiants. [less ▲] Detailed reference viewed: 50 (7 UL)![]() Vögele, Claus ![]() Book published by University of Luxembourg (2012) Detailed reference viewed: 118 (0 UL)![]() ![]() Cicotti, Claudio ![]() in Bancheri, Salvatore (Ed.) Italian outside of Italy (2012) Detailed reference viewed: 97 (2 UL)![]() Zetzsche, Dirk Andreas ![]() in Hachmeister et al., Bilanzrecht (2018) Detailed reference viewed: 143 (12 UL)![]() Zetzsche, Dirk Andreas ![]() in Bilanzrecht (2020) Detailed reference viewed: 61 (5 UL)![]() Zetzsche, Dirk Andreas ![]() in Rechnungslegungsrecht (2021) Detailed reference viewed: 20 (0 UL)![]() Zetzsche, Dirk Andreas ![]() in Claussen, Carsten Peter; Scherrer, Gerhard (Eds.) Kölner Kommentar zum Rechnungslegungsrecht (2011) Detailed reference viewed: 102 (5 UL)![]() Lehmann, Harry ![]() in Glissando (2016), 29(2), 71-72 Detailed reference viewed: 19 (0 UL)![]() Lehmann, Harry ![]() in MusikTexte (2015), 145(2), 78-79 Detailed reference viewed: 22 (0 UL)![]() Zetzsche, Dirk Andreas ![]() in KAGB (2019) Detailed reference viewed: 49 (1 UL) |
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