Publikationsserver der Ostbayerischen Technischen Hochschule Regensburg
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Developing future competencies by combining case-based learning, knowledge nuggets and gamification
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A forensic analysis of GNSS spoofing attacks on autonomous vehicles
No full textGlobal Navigation Satellite Systems (GNSSs) are essential for modern technology, enabling precise geographic positioning in aviation, maritime shipping, and automotive systems. In the future, their role will be even more critical for autonomous vehicles, which rely on accurate localization for navigation and decision-making. However, the increasing connectivity of autonomous vehicles exposes them to cyber threats, including GNSS spoofing attacks, which manipulate location data to mislead onboard systems. As reliance on GNSS grows, so does the risk posed by spoofing attacks, making it a critical security concern. This paper describes GNSS spoofing attacks on autonomous vehicles, focusing on their detection both during and after an attack. Furthermore, we analyze data storage strategies to facilitate effective forensic analysis. We highlight the importance of position, signal, and camera data, which should be preserved to ensure a comprehensive forensic investigation. Finally, we suggest a simulation setup that enables studying which data could be used for a forensic investigation. Additionally, we examine established data frameworks and decide whether they are suitable for detecting GNSS spoofing attacks
Comparative validation of surgical phase recognition, instrument keypoint estimation, and instrument instance segmentation in endoscopy: Results of the PhaKIR 2024 challenge
No full textReliable recognition and localization of surgical instruments in endoscopic video recordings are foundational for a wide range of applications in computer- and robot-assisted minimally invasive surgery (RAMIS), including surgical training, skill assessment, and autonomous assistance. However, robust performance under real-world conditions remains a significant challenge. Incorporating surgical context - such as the current procedural phase - has emerged as a promising strategy to improve robustness and interpretability. To address these challenges, we organized the Surgical Procedure Phase, Keypoint, and Instrument Recognition (PhaKIR) sub-challenge as part of the Endoscopic Vision (EndoVis) challenge at MICCAI 2024. We introduced a novel, multi-center dataset comprising thirteen full-length laparoscopic cholecystectomy videos collected from three distinct medical institutions, with unified annotations for three interrelated tasks: surgical phase recognition, instrument keypoint estimation, and instrument instance segmentation. Unlike existing datasets, ours enables joint investigation of instrument localization and procedural context within the same data while supporting the integration of temporal information across entire procedures. We report results and findings in accordance with the BIAS guidelines for biomedical image analysis challenges. The PhaKIR sub-challenge advances the field by providing a unique benchmark for developing temporally aware, context-driven methods in RAMIS and offers a high-quality resource to support future research in surgical scene understanding
Environmental advantages and recycling potential of temporarily flowable backfill as bedding material for district heating pipes
No full textDistrict heating networks are a key to a successful transformation towards climate neutrality. Typically, District Heating Pipes (DHP) are embedded in coarse sand with specific grain size distributions and soil properties. An alternative to this are the temporarily flowable backfill materials (TFB). These are a mixture of aggregate, binder (e.g. cement), water and, if necessary, additional supplements, e.g. bentonite. TFB can be mixed-on-site or mixed-in-plant, depending on the boundary conditions. Where possible, the excavated soil is used as aggregate. This paper will look at possible environmental advantages as part of a life cycle assessment, especially regarding the carbon footprint, if TFB is used in place of typical sand bedding. A total of 7 environmental impact factors are compared as part of a case study. As there are a multitude of variables with widely ranging impact for the calculation of the environmental impact, an additional sensitivity study was performed, to determine key parameters for the carbon footprint. In a multitude of cases, it can be shown that TFB has a smaller carbon footprint compared to sand bedding, as the number of transports can be greatly reduced and the TFB doesn’t need to be compacted. These factors predominate the need of cement, which is negatively connoted regarding the environmental impact.
If the excavated soil is not eligible as an aggregate for TFB, an alternative base component is necessary. Typically, mixed-in-plant-produced TFB uses sand, as the properties of TFB based on recycling materials has hardly been investigated. In order to conserve natural resources and at the same time recycle construction waste, investigations were carried out into the production and strength behavior of TFB made from different construction materials. The main goal was to mix TFB which is easily re-excavated, as per German guideline H ZFSV. This was achieved with every recycling material, but with varying amount of cement necessary. As part of a long-term study, a delayed increase in strength depending on the source material could be shown. This is due to pozzolanic reactions
Stacking the odds: full-stack quantum system design space exploration
No full textDesign space exploration (DSE) plays an important role in optimising quantum circuit execution by systematically evaluating different configurations of compilation strategies and hardware settings. In this paper, we conduct a comprehensive investigation into the impact of various layout methods, qubit routing techniques, and optimisation levels, as well as device-specific properties such as different variants and strengths of noise and imperfections, the topological structure of qubits, connectivity densities, and back-end sizes. By spanning through these dimensions, we aim to understand the interplay between compilation choices and hardware characteristics. A key question driving our exploration is whether the optimal selection of device parameters, mapping techniques, comprising of initial layout strategies and routing heuristics can mitigate device induced errors beyond standard error mitigation approaches. Our results show that carefully selecting software strategies (e.g., mapping and routing algorithms) and tailoring hardware characteristics (such as minimising noise and leveraging topology and connectivity density) significantly improve the fidelity of circuit execution outcomes, and thus the expected correctness or success probability of the computational result. We provide estimates based on key metrics such as circuit depth, gate count and expected fidelity. Our results highlight the importance of hardware–software co-design, particularly as quantum systems scale to larger dimensions, and along the way towards fully error corrected quantum systems: Our study is based on computationally noisy simulations, but considers various implementations of quantum error correction (QEC) using the same approach as for other algorithms. The observed sensitivity of circuit fidelity to noise and connectivity suggests that co-design principles will be equally critical when integrating QEC in future systems. Our exploration provides practical guidelines for co-optimising physical mapping, qubit routing, and hardware configurations in realistic quantum computing scenarios
Langzeitmonitoring des bodenphysikalischen Materialverhaltens von ZFSV bei erdverlegten Stromrohren in ZFSV Bettung anhand des DC CTL DBI Projekts
No full textLangzeitmonitoring der Saugspannung, der Temperatur, der Wärmeleitfähigkeit und des Wassergehalts von zeitweise fließfähigen selbstverdichtenden Verfüllbaustoffen bei erdverlegten gasisolierten Übertragungsleitungen anhand des DC CTL DBI Projektes.
Unter Realbedingungen ergaben sich annähernd konstante bodenphysikalische Eigenschaften während der gesamten Versuchslaufzeit. Die Wärmeableitung durch das Bettungsmaterial ist daher gegeben
Miniaturisierter Wasserstoffsensor basierend auf der 3-Omega Methode
No full textDie Arbeit stellt einen thermischen Wasserstoffsensor auf Siliziumbasis vor, der mit der 3-Omega Messmethode betrieben wird. Durch das dynamische Messverfahren, die große Sensoroberfläche bei gleichzeitig geringer thermischer Masse und der Materialkombination wird eine Auflösungsgrenze von 55 ppm Wasserstoff in Stickstoff erreicht
