OPUS Online Publikationen der Universität Stuttgart
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Automating deployment and testing in distributed networks of Electronic Control Units
No full textIncreasing complexity in automotive software has made manual testing and deployment in distributed networks of Electronic Control Units (ECUs) both time-consuming and error-prone. This thesis explores and implements a framework automating deployment and testing in distributed networks of ECUs. The proposed solution combines Ansible-based deployment with Gherkin-style test case descriptions, integrated into a CI/CD pipeline to enable consistent and repeatable testing automation. The resulting prototype called Automated Deployment and Testing of ECUs (ADATE), automates the testing of software components with automated deployment across simulated devices in a distributed environment. The framework demonstrates how automation in a distributed environment can make the testing process of ECUs both more efficient and reduce manual effort, offering a foundation for future adaptations in real-world automotive environments.Im Automobilbereich wird Software immer komplexer. Dies hat zur Folge, dass das manuelle Testen und die Bereitstellung auf Steuergeräten (ECUs) in verteilten und dezentralisierten Netzwerken einerseits mit einem hohen Zeitaufwand verbunden ist und andererseits eine hohe Fehleranfälligkeit aufweist. Diese Bachelorarbeit befasst sich mit einer Untersuchung der entsprechenden Literatur und der Implementierung eines Frameworks, welches die Automatisierung der Bereitstellung von Softwarekomponenten sowie deren Testen in verteilten Netzwerken von Steuergeräten ermöglicht. Das empfohlene Konzept verknüpft ein auf Ansible basierendes Bereitstellen mit Testbeschreibungen in Gherkin-Syntax und integriert dies in eine CI/CD-Pipeline, um eine konsistente Testautomatisierung zu gewährleisten. Der entwickelte Prototyp mit dem Namen "Automated Deployment and Testing of ECUs" (ADATE) führt eine Automatisierung der Softwarekomponententests sowie der Verteilung dieser Komponenten auf die im Netzwerk simulierten Geräte durch. Das Framework demonstriert, wie der Testprozess von Steuergeräten in einer verteilten Umgebung automatisiert werden kann, um ihn effektiver zu gestalten und manuelle Aufwände zu reduzieren. Des weiteren bietet dieser Ansatz eine Grundlage für zukünftige Einsatzmöglichkeiten in realen Umgebungen
Fractional calculus for distributions
No full textFractional derivatives and integrals for measures and distributions are reviewed. The focus is on domains and co-domains for translation invariant fractional operators. Fractional derivatives and integrals interpreted as -convolution operators with power law kernels are found to have the largest domains of definition. As a result, extending domains from functions to distributions via convolution operators contributes to far reaching unifications of many previously existing definitions of fractional integrals and derivatives. Weyl fractional operators are thereby extended to distributions using the method of adjoints. In addition, discretized fractional calculus and fractional calculus of periodic distributions can both be formulated and understood in terms of -convolution.Projekt DEA
Coherent Rydberg excitations and photon correlations in dense thermal vapor cells
No full textThis thesis describes the second generation of experiments towards a single-photon source concept based on a thermal rubidium vapor in a Rydberg-blockaded microcell. First, the situation is described in the density matrix formalism, and the requirements for the experimental system are derived. Key results of dipolar interactions and the influence of optical cavities are studied to contextualize the major challenges of the concept. In the first experimental part the fabrication of vapor cells and specifically our wedge vapor cell design is studied. Based on the daily experimental operation over several years the design is further improved, and the operational limits are marked out. A novel set of vapor cells with internal optical cavity is fabricated and used in a pilot experiment as a path towards a collectively enhanced, superradiant ensemble. The single-photon source concept optical setup is explained along its full development towards a well characterized and stable platform for all experiments with ns laser pulses that provide sufficient power for GHz Rabi frequencies. Spectroscopic experiments involving a strong light-induced atomic desorption (LIAD) pulse serve as benchmark for the performance of the inverted four-wave mixing (FWM) excitation scheme, and several open questions beyond our current understanding are identified. Finally, the single-photon source concept is tested for its photon statistics, which necessitates a careful analysis of statistical significance in the realm of low total correlation counts
Trifunctional antibody-cytokine fusion protein formats for tumor-targeted combination of IL-15 with IL-7 or IL-21
No full textCytokines from the common gamma chain receptor family, such as IL-15, IL-21 and IL-7, show promise for cancer immunotherapy and have been incorporated individually into the immunocytokine approach. However, their efficacy as monotherapy is limited. Here, we investigated the molecular design of tumor-directed trifunctional antibody-cytokine fusion proteins for a combinatorial approach of IL-15 with either IL-7 or IL-21. Various fusion proteins differing in antibody format, cytokine composition and arrangement were generated and cooperative cytokine activity assessed in solution and bound to target cells. Comparative analysis revealed that formats with cytokines positioned at the N- and C-termini of the antibody were more effective than those arranged in series. For the former design, cooperative effects were observed with the scFv-based (IL-15+IL-7) trifunctional fusion protein, primarily enhancing the proliferation of naive T cells, while the scFv/Fab-based (IL-15+IL-21) trifunctional fusion proteins enhanced IFN-y release and the cytotoxic potential of T cells. Combining cytokines in the two-in-one molecule approach was principally advantageous when bound to target cells. Greater potency in inducing JAK-STAT pathway activation highlighted the importance of cytokine colocalization for cooperative receptor activation. Compared to the Fab-based (IL-15+IL-21) format, the scFv-based (IL-15+IL-21) format displayed a tendency towards higher activity in targeted and lower activity in untargeted settings, emphasizing the targeted concept. Thus, this study underscores the importance of molecular design in developing trifunctional immunocytokines and identified the scFv-based trifunctional (IL-15+IL-21) fusion protein, with the antibody in the central position, as a particularly promising candidate for further drug development.German Cancer Ai
Effect of data preparation in the context of fair classification
No full textThis thesis investigates the critical role of data preparation in shaping the predictive performance and fairness of binary classification models. Given that the quality and composition of training data significantly influence model behaviour, especially concerning embedded biases, ensuring that training data is both accurate and fair is essential for the development of trustworthy machine learning systems. To address this, we extend an existing data processing pipeline, substantially broadening its data preparation stage with the integration of sixteen additional methods across five distinct components. This expansion allows for a more comprehensive evaluation of the interplay between data preparation, predictive accuracy, and algorithmic fairness.
Our empirical study employs a diverse set of classifiers and evaluation metrics, including several newly developed scores specifically designed to capture the nuanced effects of data preparation on model outcomes. The analysis spans both real-world and synthetic datasets, providing a robust foundation for our findings. Key insights include the observation that simply increasing the number of data preparation components does not necessarily improve model performance. Instead, optimal results often depend on carefully chosen methods and execution orders, with some components displaying strong positional dependencies. Additionally, our results reaffirm the well-documented trade-off between fairness and accuracy, yet also demonstrate that it is possible to identify configurations where both can be improved simultaneously.
These findings not only deepen our understanding of data preparation in the context of fair classification but also offer concrete, empirically grounded recommendations for practitioners. Our work lays the foundation for more informed pipeline design, providing a flexible, modular framework that can be readily extended to accommodate emerging data preparation techniques and new evaluation metrics.Diese Arbeit untersucht die entscheidende Rolle der Datenvorbereitung für die Vorhersageleistung und Fairness von binären Klassifikationsmodellen. Da Qualität und Zusammensetzung der Trainingsdaten das Modellverhalten maßgeblich beeinflussen, insbesondere im Hinblick auf eingebettete Verzerrungen, ist es entscheidend, dass Trainingsdaten sowohl akkurat als auch fair sind, um vertrauenswürdige maschinelle Lernsysteme zu entwickeln. Zu diesem Zweck erweitern wir eine bestehende Datenverarbeitungspipeline erheblich, indem wir deren Datenvorbereitungsphase durch die Integration von sechzehn zusätzlichen Methoden in fünf verschiedenen Komponenten umfassend ausbauen. Diese Erweiterung ermöglicht eine gründlichere Bewertung des Zusammenspiels zwischen Datenvorbereitung, Vorhersagegenauigkeit und algorithmischer Fairness.
Unsere empirische Studie verwendet eine Vielzahl von Klassifikatoren und Bewertungsmetriken, darunter mehrere neu entwickelte Maße, die speziell darauf ausgelegt sind, die subtilen Auswirkungen der Datenvorbereitung auf Modellergebnisse zu erfassen. Die Analyse umfasst sowohl reale als auch synthetische Datensätze und bietet damit eine solide Grundlage für unsere Erkenntnisse. Zu den zentralen Einsichten zählt die Beobachtung, dass eine bloße Erhöhung der Anzahl von Datenvorbereitungskomponenten nicht zwangsläufig zu einer Verbesserung der Modellleistung führt. Vielmehr hängen optimale Ergebnisse oft von sorgfältig ausgewählten Methoden und deren Reihenfolge ab, wobei einige Komponenten starke Positionsabhängigkeiten aufweisen. Zusätzlich bestätigen unsere Ergebnisse den vielfach dokumentierten Zielkonflikt zwischen Fairness und Genauigkeit, zeigen jedoch auch, dass es möglich ist, Konfigurationen zu identifizieren, bei denen beide Aspekte gleichzeitig verbessert werden können.
Diese Erkenntnisse vertiefen nicht nur unser Verständnis der Datenvorbereitung im Kontext fairer Klassifikation, sondern bieten Praktikern konkrete, empirisch fundierte Empfehlungen. Unsere Arbeit legt somit die Grundlage für ein besser informiertes Pipeline-Design und stellt einen flexiblen, modularen Rahmen bereit, der leicht erweitert werden kann, um zukünftige Datenvorbereitungstechniken und neue Bewertungsmetriken zu integrieren
The size of the functional base of support decreases with age
No full textFalls occur more often as we age. To identify people at risk of falling, balance analysis requires an accurate base-of-support model. We previously developed a functional base-of-support (fBOS) model for standing young adults and showed that its area is smaller than the footprint area. Our fBOS model is a polygon that contains centre-of-pressure trajectories recorded as standing participants move their bodies in the largest possible loop while keeping their feet flat on the ground. Here we assess how the size of the fBOS area changes with age by comparing 38 younger (YA), 14 middle-aged (MA), and 34 older adults (OA).
The fBOS area is smaller in older adults: OA area is 58% of the YA area (p<0.001), and 59% of the MA area (p=0.001), with no difference between YA and MA. The reduction in fBOS area among the OA is primarily caused by a reduction in the length of the fBOS. In addition, among older adults smaller fBOS areas correlated with a lower score on the Short Physical Performance Battery (τ=0.28, p=0.04), a reduced walking speed (τ=0.25, p=0.04), and a higher frailty level (p=0.09). So that others can extend our work, we have made our fBOS models available online
Development pathway from chitin-based organisms to chitosan-based photoresponsive thin-films with modulation in physiochemical properties during irradiation
No full textProbabilistische Modellierung von Populationsvariabilität
No full textVincent Wagner's dissertation summarises progress in the probabilistic modelling of population variability. It comprises two chapters with complementary approaches to this challenging and broad topic. The first chapter deals with the Method of Moments for the Chemical Master Equation, while the second chapter uses random variable transformations to estimate distributed simulation model parameters
Carrier-phase DNS of ignition and combustion of iron particles in a turbulent mixing layer
No full textThree-dimensional carrier-phase direct numerical simulations (CP-DNS) of reacting iron particle dust clouds in a turbulent mixing layer are conducted. The simulation approach considers the Eulerian transport equations for the reacting gas phase and resolves all scales of turbulence, whereas the particle boundary layers are modelled employing the Lagrangian point-particle framework for the dispersed phase. The CP-DNS employs an existing sub-model for iron particle combustion that considers the oxidation of iron to FeO and that accounts for both diffusion- and kinetically-limited combustion. At first, the particle sub-model is validated against experimental results for single iron particle combustion considering various particle diameters and ambient oxygen concentrations. Subsequently, the CP-DNS approach is employed to predict iron particle cloud ignition and combustion in a turbulent mixing layer. The upper stream of the mixing layer is initialised with cold particles in air, while the lower stream consists of hot air flowing in the opposite direction. Simulation results show that turbulent mixing induces heating, ignition and combustion of the iron particles. Significant increases in gas temperature and oxygen consumption occur mainly in regions where clusters of iron particles are formed. Over the course of the oxidation, the particles are subjected to different rate-limiting processes. While initially particle oxidation is kinetically-limited it becomes diffusion-limited for higher particle temperatures and peak particle temperatures are observed near the fully-oxidised particle state. Comparing the present non-volatile iron dust flames to general trends in volatile-containing solid fuel flames, non-vanishing particles at late simulation times and a stronger limiting effect of the local oxygen concentration on particle conversion is found for the present iron dust flames in shear-driven turbulence.Projekt DEALKarlsruher Institut für Technologi
Vestigial singlet pairing in a fluctuating magnetic triplet superconductor and its implications for graphene superlattices
No full textStacking and twisting graphene layers allows to create and control a two-dimensional electron liquid with strong correlations. Experiments indicate that these systems exhibit strong tendencies towards both magnetism and triplet superconductivity. Motivated by this phenomenology, we study a 2D model of fluctuating triplet pairing and spin magnetism. Individually, their respective order parameters, d and N , cannot order at finite temperature. Nonetheless, the model exhibits a variety of vestigial phases, including charge-4 e superconductivity and broken time-reversal symmetry. Our main focus is on a phase characterized by finite d ⋅ N , which has the same symmetries as the BCS state, a Meissner effect, and metastable supercurrents, yet rather different spectral properties: most notably, the suppression of the electronic density of states at the Fermi level can resemble that of either a fully gapped or nodal superconductor, depending on parameters. This provides a possible explanation for recent tunneling experiments in the superconducting phase of graphene moiré systems.Projekt DEA