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Caroline Ungher-Sabatier wird heute meist mit dem Altsolo bei der Uraufführung der 9. Symphonie Ludwig van Beethovens in Verbindung gebracht. Ihre größten Erfolge konnte sie jedoch mit der italienischen Oper in den 1830er Jahren feiern. Bisher fand ihre sängerische Laufbahn und ihre Kontakte in Wien – abgesehen von Franz Schubert und Beethoven – kaum Beachtung. Deswegen beschäftigt sich diese Masterarbeit eingehend mit der Künstlerin und Sängerin Caroline Ungher-Sabatier, deren Lebensweg mit der Stadt Wien verknüpft ist. Sie genoss dort ihre musikalische Ausbildung, kehrte, nach ihren großen Erfolgen in Italien, 1839 und 1840 für Gastspiele an das Kärntnertortheater zurück und hielt lebenslang ein Netzwerk zu berühmten und bekannten Persönlichkeiten in Wien aufrecht. Nach ihrem Bühnenabschied war Ungher-Sabatier als Gesangspädagogin tätig und setzte sich auch in Wien für ihre Schülerinnen ein.
Neben ihrer erfolgreichen Karriere in der italienischen Oper pflegte Ungher-Sabatier das deutsche Liedrepertoire und komponierte eigene Lieder.
Ihr Werdegang und ihre Rezeption in Wien werden anhand von zeitgenössischen Artikeln aus Zeitungen und Zeitschriften untersucht. Um einen tieferen Einblick in Caroline Ungher-Sabatiers Wiener Netzwerk nach ihrer Opernkarriere zu ermöglichen, wurden ihr Stammbuch und über hundert Briefe ausgewertet.
The internet has often been considered a 'technology of freedom' – a nearly revolutionary tool believed to flatten social hierarchies and democratize access to media by 'giving voice' to everybody equally. Contradictory to this point of view, research has shown the existence of a 'digital divide,' the phenomenon that access to and use of the internet, as well as the outcomes derived from this use, correlate with pre-existing inequalities.
Based on ethnographic fieldwork among activists in Dakar, Senegal, this thesis analyzes how inequalities shape and are shaped by the relationships between activists and smartphones. Do smartphones indeed flatten social hierarchies, or are inequalities rather reproduced – or even reinforced – through them?
Diese Arbeit untersucht die Perzeption der Vokale /a/, /ɐ/ und /ɐ̃/ durch deutsche erwachsene Portugiesischlerner. Ziel war herauszufinden, ob deutsche L1-Sprecher in der Lage sind, die genannten Laute zu unterscheiden, unter anderem in Abhängigkeit von ihrem Fremdsprachenniveau im EP.
Die Teilnehmer der Studie waren 27 deutsche Muttersprachler, die EP im Erwachsenenalter und zumeist an der Universität erlernen oder erlernt haben. Die Kontrollgruppe bildeten 33 portugiesische Muttersprachler. Beide Gruppen nahmen an einem Online-Perzeptionstest teil, dessen Aufbau sich an der Studie von Darcy und Krüger (2012) orientiert. Während des Tests mussten die Probanden aus einer Lautsequenz von drei einsilbigen Kunstwörtern mit der Silbenstruktur CVC dasjenige Kunstwort identifizieren, das einen anderen Vokal beinhaltete als die anderen zwei. Neben dem Perzeptionstest nahmen alle Teilnehmer an einem Einstufungstest für das EP teil, der aus einem C-Test und einem Vokabeltest bestand.
During RUN3 (2021-2023) of the Large Hadron Collider, the Time Projection Chamber (TPC) of ALICE will be operated with quadruple stacks of Gas Electron Multipliers (GEMs). This technology will allow to overcome the rate limitation due to the gated operation of the Multi-Wire Proportional Chambers (MWPCs) used in RUN1 (2009-2013) and RUN2 (2015-2018).
As part of the Upgrade project, long-term irradiation tests, so called "ageing tests", have been carried out. A test setup with a detector using a quadruple stack of 10x10cm2 GEMs was built and operated in Ar-CO2 and Ne-CO2-N2 gas mixtures. The detector performance such as gas gain and energy resolution were monitored continuously. In addition, outgassing tests of materials used for the assembly process of the upgraded TPC were performed. To reach the expected dose of the GEM-based TPC, the detector was operated at much higher gains than the TPC. It was found, that the GEMs could keep their performance within the projected lifetime of the TPC. Most of the tested materials showed no negative impact on the detector. For the tested epoxy adhesive no certain conclusion could be drawn.
At much higher doses than expected for the upgraded TPC, a new phenomenon was observed, which changed the hole geometry of the GEMs and led to a degradation of the energy resolution. Even though its occurrence is not expected during the lifetime of the GEM-based TPC, simulations were carried out to study this effect more systematically. The simulations confirmed, that a change of the hole geometries of the GEMs, lead to an increase of the local gain variation, which results in a decrease of the energy resolution.
Furthermore the effect of methane as quench gas on GEMs was studied, even though this gas is not foreseen to be used in the TPC. From ageing tests with single-wire proportional counters it is well known that hydrocarbons are produced in the plasma of the avalanches, which cover the electrodes and lead to a degradation of the detector performance. Even though GEMs have a quite different geometry, the ageing tests showed, that also this technology tends to methane-induced ageing. A loss of gas gain as well as a degradation of the energy resolution due to deposits on the electrodes was monitored. A qualitative and quantitative comparison between ageing in GEMs and proportional counters was performed.
This work derived the value of α-induced production cross sections of 77Kr and 77Br at α-energies of 12 MeV and 14 MeV, the thick target yields of 77Kr and 77Br at α-energies of 11.19 MeV, 13 MeV and 15.1 MeV and the thick target yield of 80Br as well as 80mBr at an α-energy of 15.1 MeV using the activation technique...
Analysis of machine learning prediction quality for automated subgroups within the MIMIC III dataset
(2023)
The motivation for this master’s thesis is to explore the potential of predictive data analytics in the field of medicine. For this, the MIMIC-III dataset offers an extensive foundation for the construction of prediction models, including Random Forest, XGBOOST, and deep learning networks. These models were implemented to forecast the mortality of 2,655 stroke patients.
The first part of the thesis involved conducting a comprehensive data analysis of the filtered MIMIC-III dataset.
Subsequently, the effectiveness and fairness of the predictive models were evaluated. Although the performance levels of the developed models did not match those reported in related research, their potential became evident. The results obtained demonstrated promising capabilities and highlighted the effectiveness of the applied methodologies. Moreover, the feature relevance within the XGBOOST model was examined to increase model explainability.
Finally, relevant subgroups were identified to perform a comparative analysis of the prediction performance across these subgroups. While this approach can be regarded as a valuable methodology, it was not possible to investigate underlying reasons for potential unfairness across clusters. Inside the test data, not enough instances remained per subgroup for further fairness or feature relevance analysis.
In conclusion, the implementation of an alternative use case with a higher patient count is recommended.
The code for this analysis is made available via a GitHub repository and includes a frontend to visualize the results.
Virtual machines are for the most part not used inside of high-energy physics (HEP) environments. Even though they provide a high degree of isolation, the performance overhead they introduce is too great for them to be used. With the rising number of container technologies and their increasing separation capabilities, HEP-environments are evaluating if they could utilize the technology. The container images are small and self-contained which allows them to be easily distributed throughout the global environment. They also offer a near native performance while at the same time aproviding an often acceptable level of isolation. Only the needed services and libraries are packed into an image and executed directly by the host kernel. This work compared the performance impact of the three container technologies Docker, rkt and Singularity. The host kernel was additionally hardened with grsecurity and PaX to strengthen its security and make an exploitation from inside a container harder. The execution time of a physics simulation was used as a benchmark. The results show that the different container technologies have a different impact on the performance. The performance loss on a stock kernel is small; in some cases they were even faster than no container. Docker showed overall the best performance on a stock kernel. The difference on a hardened kernel was bigger than on a stock kernel, but in favor of the container technologies. rkt showed performed in almost all cases better than all the others.
In dieser Arbeit wird der Strahltransport in einer Niederenergietransportsektion (LEBT) untersucht. Die Untersuchungen werden für die Betriebsmodi der im Aufbau befindlichen Neutronenquelle FRANZ an der Frankfurter Goethe-Universität durchgeführt. Hierbei wird die Akzeptanz eines Choppersystems nach der ersten Sektion des Transportwegs sowie die Akzeptanz des auf die zweite Sektion folgenden RFQ betrachtet und bestmöglich erfüllt. Die Auswirkungen durch die Raumladungswirkung des Ionenstrahls werden berücksichtigt, ebenso die mögliche thermische Belastung durch Strahlverlust an den Komponenten entlang des Strahlwegs. Weiterhin wird der Einfluss eines nicht optimierten Einschusses in den RFQ und die sich daraus ergebenden Strahleigenschaften am Ende des RFQs untersucht.