Publikationsserver der Ostbayerischen Technischen Hochschule Regensburg
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Eigenvalue perturbation in drivetrain analysis and optimization
No full textThe optimization of the dynamic behavior of drive systems often involves targeted modifications of the system characteristics. Structural and parametric modifications are used to satisfy the constraints of the dynamic requirements. However, many optimizations are still achieved by intuition or parameter variations, even though more streamlined and easy-to-implement tools such as the eigenvalue perturbation method are available. In this article, the eigenvalue perturbation method in the form of an eigenvalue sensitivity analysis is used to efficiently optimize the dynamic behavior for two different use cases using different optimization measures. This paper demonstrates, how eigenvalue perturbation theory can efficiently optimize drivetrain dynamics by systematically modifying system parameters. Two case studies show how eigenvalue sensitivity analysis achieves targeted frequency shifts to avoid resonances: (1) adapting shaft stiffness and control parameters in a torsional drivetrain, and (2) optimizing structural modifications in a wind turbine bedplate. The study introduces the eigenvector tensor product as a weighting matrix, identifying key parameters for effective redesign. Compared to conventional parameter studies, this method enables precise control over system dynamics with minimal computational effort, making it highly applicable for vibration mitigation and drivetrain optimization
Impact of heat treatment on the surface quality of electropolished WE43 alloy
No full textIn this study, the Mg alloy WE43 was solution annealed and precipitation hardened prior to electropolishing to evaluate the effects of different microstructures on the electropolishing result. While coarsely distributed precipitates led to surfaces showing wavy structures and dents after electropolishing, a uniform microstructure resulted in an even finish of the surface. The homogenization and refinement of the microstructure by heat treatment is a method to ensure improved electropolished surfaces of Mg material
Shear tests on thermal insulating clay unit masonry walls
No full textMasonry made of highly insulating clay units is a very common construction method, especially in multi-storey residential buildings. To apply this type of construction also in earthquake proven areas, the characterisation of strength and deformation properties under cyclic horizontal loads is essential. For this, a series of full-scale experimental investigations on the behaviour of walls made of thermally insulating clay unit masonry under combined loadings (N-M-V) were carried out in the Laboratory for Structural Engineering at the University of Applied Sciences Regensburg (OTH), Germany.
The aim of the static-cyclic tests was to characterise the load-deformation behaviour and the failure mechanism under earthquake loadings. In conventional buildings, stiffening walls are loaded by vertical axial forces and horizontal in-plane loadings. The interaction with the concrete floor slabs leads to restraining effects in real buildings, which create counteracting bending moments. Accordingly, in the test, the loads were applied by a combined loading of bending moment and axial force. Digital image correlation documented deformations to identify failure mechanism. Results indicate that current design approaches according to DIN EN 1996-1-1 are on the safe side regarding the load-bearing capacity of the tested walls contain load-bearing capacity reserves. Based on the failure patterns from digital image correlation, it can be recognised that a strict separation of the individual failure types does not appear to make sense, as the ultimate failure of the test specimens was caused by a combination of several failure types
Substitute test method for the local load bearing capacity of masonry with partially supported slabs
No full textWith increasing thermal insulation requirements and resource-efficient construction methods, demands on building exterior walls are rising. Monolithic exterior walls, devoid of additional insulation, require meticulous planning and
execution of the exterior wall-floor joint. Besides addressing building physics, fire safety, and sustainable construction, this detail must meet structural analysis standards. The joint’s load-bearing capacity hinges on both the masonry wall and slab loads. Masonry walls primarily bear loads from slabs and roof structures. However, slab loads induce rotation, adding bending stress to the masonry. Bending transmission depends on structural design, material parameters, and axial force, creating parameter interactions. To scrutinize various products and design variants regarding contact stiffness, load distribution, and stress concentrations, the Laboratory for Structural Engineering at the University of Applied Sciences (OTH) in Regensburg, Germany developed specific testing methods. These methods realistically capture load redistribution effects based on perforation patterns and quantify potential loadbearing reserves. Additionally, optimising design regulations based on results can accurately describe masonry’s load-deformation behaviour
Im Spannungsfeld von Ethik und Effizienz : Corporate Citizenship als strategisches Kommunikationsinstrument unternehmerischer Krankenhäuser
No full textTransnationale Organisationslogiken der extremen Rechten mit Türkeibezug in Bayern
No full textBisher liegen keine Analysen aus organisationssoziologischer Perspektive über die extreme Rechte mit Türkeibezug vor. In diesem Arbeitspapier werden Normalisierungsstrategien im transnationalen Raum und vor Ort vorgestellt. Die extrem rechten Vereine platzieren sich als Interessenvertretung nach innen und nach außen hin. Hierbei zeigt sich, dass die Etablierung und Aufrechterhaltung einer kollektiven Identität zentral für ihr Bestehen sind. Sie operieren mit zwei binären Codes, die sie flexibel einsetzen: türkisch/nicht-türkisch und muslimisch/nicht-muslimisch. Diese müssen regelmäßig reproduziert und gefestigt werden. Das funktioniert über Differenz- und Feindbildkonstruktionen, die durch öffentliche Migrations- und Integrationsdebatten zusätzlich genährt werden, sowie durch starke regionale Vernetzungen, die bis in die Türkei reichen. Daran sind auch Klientel- und Mitgliederlegitimationen geknüpft, ohne die die Organisationen schnell zerfallen würden. Hier werden diese Vernetzungen als transnationale Lebenswelten beschrieben. Das vorliegende Working Paper stellt erste Ergebnisse zur Diskussion
OpenMIBOOD: Open Medical Imaging Benchmarks for Out-Of-Distribution Detection
No full textThe growing reliance on Artificial Intelligence (AI) in critical domains such as healthcare demands robust mechanisms to ensure the trustworthiness of these systems, especially when faced with unexpected or anomalous inputs. This paper introduces the Open Medical Imaging Benchmarks for Out-Of-Distribution Detection (OpenMIBOOD), a comprehensive framework for evaluating out-of-distribution (OOD) detection methods specifically in medical imaging contexts. OpenMIBOOD includes three benchmarks from diverse medical domains, encompassing 14 datasets divided into covariate-shifted in-distribution, nearOOD, and far-OOD categories. We evaluate 24 post-hoc methods across these benchmarks, providing a standardized reference to advance the development and fair comparison of OODdetection methods. Results reveal that findings from broad-scale OOD benchmarks in natural image domains do not translate to medical applications, underscoring the critical need for such benchmarks in the medical field. By mitigating the risk of exposing AI models to inputs outside their training distribution, OpenMIBOOD aims to support the advancement of reliable and trustworthy AI systems in healthcare. The repository is available at https://github.com/remic-othr/OpenMIBOOD
Needs Assessment for an Assistance System for the Visually Impaired and Blind in Climbing and Bouldering
No full textBackground: This thesis deals with the potentials and challenges of
climbing for blind and visually impaired people. Objectives: The extent to which an
innovative technical assistance system can contribute to supporting this sport in
climbing gyms is analyzed. Methods: As part of this study, a needs analysis was
carried out using a mixed methods approach. This comprises an observational study,
expert interviews and a quantitative survey of the potential target group. Results:
The studies show that climbing can promote the development of social and physical
skills. Nevertheless, there are needs and challenges, such as finding the next hold on
a route. Conclusions: The technical assistance system could provide support by
addressing these specific challenges and needs of blind and visually impaired people
when climbing and supporting them with acoustic signals
Auditive Verarbeitungsstörungen bei Kindern, Jugendlichen und Erwachsenen : Grundlagen - Klinik - Diagnostik - Therapie
No full textDas Buch vermittelt fundierte Grundlagen, Diagnostik und Interventionsmöglichkeiten bei auditiven Verarbeitungsstörungen (AVS) im Kindes-, Jugend- und Erwachsenenalter. Auf Basis des Modells der auditiven Verarbeitung und der zugrunde liegenden Hörverarbeitungsprozesse bietet es einen umfassenden Einblick in das Störungsbild AVS und dessen Auswirkungen. Es stellt gängige Diagnostikverfahren vor und diskutiert effektive Maßnahmen zur Beratung, Kompensation und Therapie
A Twofold Strategy Towards Mature Quantum Data Management
No full textBy relying on stagnant general-purpose devices limited by the end of Moore's law, conventional data management (DM) methods are challenged by ever-increasing computational loads. As a promising alternative, we may rely on quantum processing units (QPU) as special-purpose accelerators, which may overcome the limitations of conventional systems by exploiting quantum phenomena. However, given their early-stage, prototypical nature, contemporary QPUs remain limited in size and reliability, which renders them unfit for practical scenarios.
In this thesis, we therefore propose a twofold strategy to aid the shift towards mature quantum data management. As a first fundamental pillar, our strategy rests on QPU-DM co-design: Inspired by the conventional hardware-software co-design paradigm, our method yields recommendations for the tailored design of QPU architecture, to craft quantum systems conforming to the specific requirements of DM tasks. Based on an empirical assessment involving contemporary quantum systems, and simulating enhanced QPU architectures, our method identifies the most effective among a variety of architectural enhancements, and allows us to derive recommendations on the design of QPUs tailored to DM tasks.
However, to decide whether QPU-DM co-design efforts are truly worth pursuing, we require insights into the true potential of quantum systems for DM up-front. As a second fundamental pillar, our strategy hence assesses the algorithmic aptness of our methods on quantum-inspired special-purpose hardware (HW): While classical in nature, such systems mimic the workings of pure QPUs, and thus provide a lower bound on the capabilities of future QPUs. Thereby, our strategy yields insights into the true potential of future QPUs, which are expected to achieve still higher performance upon obtaining a sufficient level of maturity.
We demonstrate the aptness of our twofold strategy on fundamental DM and query optimisation tasks by (1) deriving QPU design recommendations for the join ordering (JO) problem by applying our QPU-DM co-design method, (2) demonstrating the scalability aptness of quantum-inspired HW for extremely large JO solution spaces that prove challenging for conventional approaches, (3) deriving methods to solve the most extensive class of JO problems on quantum(-inspired) systems, and (4) conducting a still more extensive assessment of quantum-inspired HW for multiple query optimisation. Thereby, we aid the shift from currently imperfect QPUs towards systems fit for mature quantum data management.Anforderungen zur Verarbeitung stetig ansteigender Datenmengen stellen eine wachsende Herausforderung im Bereich des Datenmanagement (DM) dar, dessen etablierte Methoden auf traditionellen Allzweck-Systemen beruhen, deren Entwicklung durch das Ende des Mooreschen Gesetzes stagniert. Eine vielversprechende Alternative bieten Quantum Processing Units (QPU), welche das Potential aufweisen, die Limitationen traditioneller Systeme durch das Ausnutzen von Phänomenen der Quantenmechanik zu überwinden. Aufgrund ihres frühen Entwicklungsstadiums und ihrer prototypischen Natur sind gegenwärtige QPUs jedoch trotz dieses Potentials in ihrer Kapazität und Zuverlässigkeit begrenzt, und folglich ungeeignet für praktische Anwendungen.
In dieser Arbeit schlagen wir daher eine zweigleisige Strategie für die Entwicklung hin zu ausgereiftem Quanten-Datenmanagement vor. Als erste fundamentale Säule beruht unsere Strategie auf Techniken des QPU-DM Co-Design: Inspiriert durch das konventionelle Hardware-Software Co-Design Paradigma können wir anhand unserer Methode Empfehlungen für das maßgeschneiderte Design von QPU Architekturen ermitteln, um Quanten-Systeme zu entwerfen, welche an spezifische Anforderungen fundamentaler DM Aufgaben angepasst sind. Basierend auf empirischen Analysen gegenwärtiger Quanten-Systeme und der Simulation strukturell erweiterter QPU Architekturen identifiziert unsere Methode unter Betrachtung einer Vielzahl möglicher Alternativen die effektivsten Erweiterungen für das Design von maßgeschneiderten QPUs.
Zur Entscheidung über die Anwendung ressourcen-intensiver QPU-DM Co-Design Methoden benötigen wir vorab jedoch Erkenntnisse über das tatsächliche Potential von Quanten-Systemen für DM. Als zweite fundamentale Säule sieht unsere Strategie daher eine algorithmische Analyse von Quanten-Methoden mittels quanten-inspirierten Systemen vor: Derartige Systeme imitieren die Funktionsweise tatsächlicher QPUs, und geben daher trotz ihrer klassischen Natur Aufschluss über die Mindest-Leistungsfähigkeit und das Potential tatsächlicher, ausgereifter QPUs, welche zur Ausnutzung von Quantenphänomenen befähigt sind.
Wir demonstrieren die Tauglichkeit unserer zweigleisigen Strategie für fundamentale DM Probleme durch (1) das Ermitteln von Design-Empfehlungen für das Join Ordering (JO) Problem durch Anwendung unserer QPU-DM Co-Design Methode, (2) das Demonstrieren der Skalierbarkeit quanten-inspirierter Methoden für extrem große JO Lösungsräume, (3) das Konzipieren von Methoden zum Lösen der umfangreichsten Klasse von JO Problemen auf quanten(-inspirierten) Systemen, und (4) das Durchführen einer noch umfangreicheren Analyse quanten-inspirierter Methoden für Multiple Query Optimisation. Dadurch unterstützen wir die Transformation von aktuellen QPU-Prototypen hin zu Quanten-Systemen, die für ausgereiftes Quanten-Datenmanagement geeignet sind