@article{GeldofKopačinStrausetal., author = {Geldof, Arne and Kopačin, Jan and Straus, Izidor and Kriegl, Raphael and Kravanja, Gaia and Hribar, Luka and Jezeršek, Matija and Shamonin, Mikhail and Kokot, Gašper and Drevenšek-Olenik, Irena}, title = {Transfer of Energy and Momentum Between Magnetoactive Surface Microstructure and a Solid Object}, series = {Advanced Engineering Materials}, volume = {28}, journal = {Advanced Engineering Materials}, number = {6}, publisher = {Wiley}, doi = {10.1002/adem.202502369}, pages = {9}, abstract = {Transport systems utilizing magnetic materials are very promising for applications that require contactless operation and compatibility with biological processes. A critical parameter in these systems is the efficiency of energy and momentum transfer between the transporting platform and the objects being transported. We investigate the physical mechanisms driving directional transport of solid objects by microlamellar structures laser-inscribed on the surface of a magnetoactive elastomer (MAE). When subjected to a rotating magnetic field with a magnitude of 175 mT and a time period of 0.4 s, the lamellas reorient within a few milliseconds, reaching angular velocities up to 1100 rad s-1. This rapid motion is crucial for efficient momentum and energy transfer to objects in contact with the lamellas. The analysis of collisions of a single lamella with a lead ball with a 2.2 mm diameter shows that the lamella can transfer around 50 nJ of energy, propelling the ball to a speed of around 35 mm s-1. We show how this value sets the upper limit for the ball's transport speed on microlamellar structures. We also explain the background of three distinct transport regimes (kicking, pushing, and bouncing modes) observed on these magnetically driven "conveyor belts".}, language = {en} } @masterthesis{Bachl, type = {Bachelor Thesis}, author = {Bachl, Hannes}, title = {Initial 5G synchronisation using a time-domain correlator}, address = {Regensburg}, doi = {10.35096/othr/pub-8904}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-89048}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {x, 63, XXI}, abstract = {The following Bachelor's thesis explores the implementation of a fre- quency correlator in the time-domain as required for the initial synchro- nisation in 5G mobile networks. Exact time domain synchronisation is required for modern mobile networks to allow reconstruction of the em- ployed physical modulations schemes without producing excessive amounts of interference. This is the first step in the discovery process of mobile radio cells. Initial the theoretical foundations of time synchronisation mechanisms as used in 5G networks are explored, including the physical modulation schemes employed. The different implementations of the synchronisa- tion algorithms are considered and a single algorithm is chosen for im- plementation. The chosen algorithm is then implemented and the implementation and findings are discussed. The hardware basis for the implementation is a Xilinx RFSoC, a high speed FPGA with associated analog-to-digital con- verts designed for RF signal processing. Finally there will be a discussion of possible optimisations and problems encountered during implementation.}, language = {en} } @unpublished{GaubeJussupowKokjeetal., author = {Gaube, Susanne and Jussupow, Ekaterina and Kokje, Eesha and Khan, Jowaria and Bondi-Kelly, Elizabeth and Schicho, Andreas and Kitamura, Felipe Campos and Koch, Timo Kevin and Ezer, Timur and Mottok, J{\"u}rgen and Lermer, Eva and Ghassemi, Marzyeh and Colak, Errol}, title = {Examining Reliance Patterns on AI Advice in Medical Imaging: a Mixed-Methods Randomized Crossover Experiment}, doi = {10.31219/osf.io/4wv8j_v3}, pages = {20}, abstract = {Background: Artificial intelligence (AI) holds significant potential to support diagnostic decision-making; however, evidence regarding its clinical utility remains mixed. Often, the collaboration between clinicians and AI systems does not surpass the individual performance of unaided humans or standalone AI. Yet, currently, the mechanisms that limit human-AI synergy are poorly understood. This study examined the impact of AI advice on diagnostic decision-making among experts and novices, focusing on reliance patterns. Methods: We used a mixed-methods crossover experimental design with a think-aloud and an eye-tracking study arm. Participants were 50 task experts (radiologists) and 75 novices (non-radiologist physicians and medical trainees) from 10 countries. They reviewed 50 head CT scans and every case was examined in three time-separate sessions in randomized order. In each session, participants were exposed to different experimental conditions: (a) control, no AI prediction; (b) basic advice, AI prediction without annotations; and (c) XAI advice, AI prediction with scan annotations. For each case, participants had to determine if the patients had an intracranial hemorrhage (ICH). The main outcomes were diagnostic performance, confidence in the diagnosis, case reading time, and AI advice usefulness ratings. Findings: Both overreliance on incorrect advice and underreliance on correct advice occurred. Underreliance was associated with high uncertainty and, in absolute terms, had a more detrimental impact on diagnostic performance than overreliance. Correct XAI advice reduced underreliance, improved performance (OR=1·84, p<0·0001), and confidence (b=0·15, p<0·0001), particularly when reviewing more difficult cases with ICH. Surprisingly, correct XAI did not reduce reading time (b=1·81, p=0·0713). XAI was perceived as more useful than basic AI advice (b=0·12, p=0·0029), especially among novices. Interpretation: The occurrence of both under- and overreliance highlights the need for efficient counterstrategies beyond classic XAI methods to foster appropriate reliance and synergy.}, language = {en} } @unpublished{AchhammerFioritiPatoniaetal., author = {Achhammer, Anton and Fioriti, Davide and Patonia, Aliaksei and Sterner, Michael}, title = {The impact of hydrogen underground storage on fair partnerships: a GIS-based integration of salt caverns into PyPSA-Earth}, publisher = {SSRN}, doi = {10.2139/ssrn.6307406}, pages = {22}, abstract = {The increasing demand for hydrogen in Europe and the development of cross-border infrastructure, such as the SoutH2 Corridorconnecting Tunisia, Italy, Austria, and Germany, underscore the importance for hydrogen storage solutions to ensure supplysecurity and competitive pricing. Without storage, producers face increased market dependency, as electrolyzers require con-tinuous operation to remain economically viable. At the same time, storage offers opportunities to strengthen domestic valuechains by securing hydrogen supply for local industries. To assess the system-level impact of underground hydrogen storageand its implications for hydrogen partnerships, we integrate GIS-based salt cavern potentials into PyPSA-Earth and apply theframework to Tunisia. Salt caverns are currently largely considered the most economical option for large-scale hydrogen storage,offering operational flexibility. Underground storage is represented as an endogenously optimised, regionally constrained option,enabling a direct comparison between scenarios with and without geological storage under identical demand, technology, andpolicy assumptions.Our results show that underground hydrogen storage enables seasonal balancing at multi-terawatt-hour scale, reshaping hydro-gen system design. Storage availability substitutes most aboveground hydrogen tank capacity, improves electrolyser utilisation,and reduces levelised hydrogen production costs by approximately 0.10 € kg-1. Moreover, it decouples hydrogen production fromshort-term electricity variability and export demand, enhancing supply stability and export competitiveness.Beyond the Tunisian case, the findings underscore the strategic role of geological storage in international hydrogen trade. Byincreasing resilience and reducing cost volatility, underground hydrogen storage strengthens the position of exporting regionsand supports more balanced and sustainable hydrogen partnerships.}, language = {en} } @article{Sippenauer, author = {Sippenauer, Thomas}, title = {Bayerische Regionalkonferenz an der OTH Regensburg}, series = {SPEKTRUM}, journal = {SPEKTRUM}, number = {2}, address = {Regensburg}, pages = {29 -- 29}, abstract = {Kann ein flexibilisierter Einsatz der Stromverbraucher zur Netzentlastung in kritischen Zeitpunkten beitragen und wie ist der aktuell h{\"a}ufig genannte Begriff des „zellul{\"a}ren Ansatzes" in diesem Zusammenhang zu verstehen? Am 21. September 2018 waren zahlreiche Partner des Projektes C/sells sowie Vertreterinnen und Vertreter von Umweltschutzorganisationen und aus der Politik an der OTH Regensburg zu Gast, um diesen Fragen nachzugehen und mit Experten zu diskutieren.}, language = {de} } @article{BruecklMayer, author = {Br{\"u}ckl, Oliver and Mayer, Ulrike}, title = {Neues Forschungsprojekt f{\"u}r Biogasanlagen gestartet}, series = {SPEKTRUM}, journal = {SPEKTRUM}, number = {2}, publisher = {Spektrum}, address = {Regensburg}, pages = {35 -- 35}, abstract = {Wie k{\"o}nnen Biogasanlagen nach dem Auslaufen des EEG noch wirtschaftlich betrieben werden? Mit dieser Frage, der Untersuchung der Potenziale und Entwicklung eines Optimierungsmodells f{\"u}r Biogasanlagen im Kontext des zuk{\"u}nftigen Stromsystems besch{\"a}ftigt sich seit September 2018 ein interdisziplin{\"a}res Forscherteam der OTH Regensburg, der OTH Amberg-Weiden und des Instituts f{\"u}r Energietechnik IfE GmbH im Rahmen des Projekts OPTIBIOSY.}, language = {de} } @techreport{EichnerGrabKoeppeetal., author = {Eichner, Stefan and Grab, Robin and K{\"o}ppe, Hartmudt and Rauch, Johannes and Schuster, Merten and Scharz, Stefan and Schweiberer, Philipp}, title = {Q-Integral - aktives Blindleistungsmanagement mit dynamischen Blindleistungsquellen an der Schnittstelle Verteilungsnetz und {\"U}bertragungsnetz : Schlussbericht zum Verbundvorhaben : Berichtsdatum: 01.04.2019-30.09.2022}, address = {Braunschweig}, doi = {10.2314/KXP:1882070593}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-89308}, pages = {268}, abstract = {Im Zuge der Energiewende m{\"u}ssen bestehende Konzepte des Netzbetriebs und der Netzplanung angepasst und neue entwickelt werden. Mit steigender Anzahl dezentraler Erzeugungsanlagen im Verteilungsnetz nimmt dort das Potenzial zur Blindleistungs- Bereitstellung zu. Unterdessen werden durch den Wegfall von Großkraftwerken auf der H{\"o}SEbene Blindleistungsquellen vom Netz genommen, w{\"a}hrend die Blindleistungsbedarfe durch steigende Blindleistungsanforderungen - insbesondere in der H{\"o}S-Ebene - weiter steigen. Unter volkswirtschaftlichen Gesichtspunkten und zur Wahrung der Systemstabilit{\"a}t muss daher k{\"u}nftig mehr Blindleistung aus dem Verteilungsnetz bereitgestellt werden. In Q-Integral wurden diese Herausforderungen angenommen und der Themenkomplex des Blindleistungsmanagements ganzheitlich betrachtet. Im vorliegenden Schlussbericht werden die geleisteten Forschungsarbeiten dargestellt.}, language = {de} } @techreport{BruecklBreySchaechingeretal., author = {Br{\"u}ckl, Oliver and Brey, Ludwig and Sch{\"a}chinger, Johannes and Henneke, Markus and Eigenstetter, Florian and Vogel, Carolin and Ufkes, Antja}, title = {Netzst{\"u}tzung und Systemdienstleistungserbringung durch eine Industriezelle mit Inselnetzf{\"a}higkeit und Erneuerbaren Energien : Schlussbericht zum Verbundvorhaben: INZELL : Projektlaufzeit: 01.06.2020-31.12.2023}, address = {Regensburg}, doi = {10.2314/KXP:1928854451}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-89261}, pages = {XXII, 316}, abstract = {Infolge der Verdr{\"a}ngung von konventionellen Großkraftwerken im Kontext nationaler Klimaschutzbem{\"u}-hungen entstehen offene Flanken im Bereich der Systemsicherheit. Um weiterhin eine hohe Qualit{\"a}t, Zuverl{\"a}ssigkeit und Sicherheit bei der Strom{\"u}bertragung und -verteilung zu gew{\"a}hrleisten, m{\"u}ssen ins-besondere: • bei der Bereitstellung von Blindleistung im {\"U}bertragungsnetz, wo trotz Zunahme der Vorhaltung steigende Defizite im Blindleistungshaushalt f{\"u}r die Zukunft vorhergesagt werden [1], • der Momentanreserve, die nicht mehr systemimmanent in vielen Erzeugungs- und Bezugsanla-gen vorhanden ist und • dem Netzwiederaufbau (NWA), der bislang mittels Großkraftwerke geplant ist, neue Maßnahmen zum Schließen der L{\"u}cken gefunden werden. Aufgrund zunehmend kostensensitiver Fertigungsprozesse bei deutschen Industriebetrieben besteht die Anforderung an eine hohe Zuverl{\"a}ssigkeit der Stromversorgung. Da sowohl l{\"a}nger andauernde Versor-gungsausf{\"a}lle als auch Spannungseinbr{\"u}che des {\"o}ffentlichen Versorgungsnetzes zu hohen Kosten durch Produktionsstillstand und Sch{\"a}den f{\"u}hren k{\"o}nnen, wird auch der Aspekt der Eigenabsicherung bzw. der h{\"o}heren Versorgungsqualit{\"a}t bedeutender. Des Weiteren sind speziell energieintensive Industrieunter-nehmen gefordert, die zum Teil bisweilen bereits bestehende Eigenerzeugung weiter auszubauen und Flexibilit{\"a}ten zu erschließen, um unabh{\"a}ngiger von hohen Strombezugskosten zu sein.}, language = {de} } @inproceedings{BruecklHaslbeckVogl, author = {Br{\"u}ckl, Oliver and Haslbeck, Matthias and Vogl, Bettina}, title = {Interpretation von P-Q-Wolken als Hilfsmittel zur Bewertung von Mittelspannungsnetzen}, series = {4. OTTI Konferenz: Zuk{\"u}nftige Stromnetze 31.01- 01.02.2017, Berlin}, booktitle = {4. OTTI Konferenz: Zuk{\"u}nftige Stromnetze 31.01- 01.02.2017, Berlin}, pages = {6}, abstract = {Zwischen {\"U}bertragungs-/Verteilungsnetzbetreibern bestehen Vereinbarungen in Form von Vertr{\"a}gen und Richtlinien (z.B. DCC), die das zul{\"a}ssige Wirk- und Blindleistungs-Verhalten (P-Q-Verhalten) beschreiben. Beim Blindleistungsverhalten werden i. d. R. zul{\"a}ssige cosφ-Bereiche definiert. Typische Werte sind hierf{\"u}r cosφ ≤ 0,95 f{\"u}r den I. und II. Quadranten sowie cosφ ≤ 0,925 f{\"u}r den III. Quadranten. Der IV. Quadrant ist unzul{\"a}ssig. Netzstruktur, Verbraucher und Erzeuger beeinflussen das P-Q-Verhalten, weshalb die Einhaltung der cosφ-Grenzwerte bei sich {\"a}ndernden Faktoren zu pr{\"u}fen und ggf. Gegenmaßnahmen (z. B. Installation von Kompensationsdrosseln) zu ergreifen sind. Ziel dieser Ver{\"o}ffentlichung ist es, geeignete Parameter zu identifizieren und zu beschreiben, die einen Einfluss auf das P-Q-Verhalten und damit auf die Form der PQ- Wolke einer MS-Netzgruppe (MS-NG) aufweisen. Abbildung 1 zeigt eine beispielhafte P-Q-Wolke. Um die P-Q-Wolken verschiedener MS-Netze vergleichbar zu machen, wurden die P- und Q-Werte auf die jeweilige Bemessungsleistung der versorgenden Umspannwerktransformatoren (UWT) normiert (diese betr{\"a}gt einheitlich 40 MVA). Die P-Q-Wolke besteht dabei aus allen ¼-h-Messwerten der Summenlast am UWT innerhalb eines Jahres. Als Linien angedeutet sind beispielhaft zul{\"a}ssige cosφ-Grenzen je Quadrant.}, language = {de} } @inproceedings{HinterreiterRauchBrueckl, author = {Hinterreiter, Marion and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Long-term reactive power forecasting power grids - Challenges and methodologies}, series = {Applied Research Conference - ARC 04.07.2025, Augsburg}, booktitle = {Applied Research Conference - ARC 04.07.2025, Augsburg}, pages = {6}, abstract = {The transition of power systems from fossil fuels to renewable energy sources is driving profound changes across all voltage levels of the electrical grid, altering active power (P) as well as reactive power (Q) behavior. This transformation involves a shift from predominantly top-down, unidirectional electricity flows to bidirectional and increasingly complex flow patterns, fundamentally altering the operation and utilization of power systems. The growing integration of distributed energy resources (DERs), heat pumps (HPs), and electric vehicles (EVs) is particularly impacting lower voltage levels, which are evolving from traditionally consumer-dominated networks into active participants in energy dynamics. These developments have a significant influence on reactive power behavior, with many countries already reporting notable changes due to increased Q contributions from lower voltage levels. As bidirectional flows and decentralized generation increase, understanding and forecasting reactive power trends at these voltage levels becomes essential for ensuring grid stability and efficiency. This paper addresses the challenges of long-term Q forecasting in general by analyzing reactive power behavior in grids, the main influencing grid parameters and introducing existing approaches and concepts, analyzing their applicability, and discussing the associated challenges and methodologies. By shedding light on this underexplored area, the study aims to contribute to the development of advanced long-term reactive power forecasting methods and highlighting research trends.}, language = {en} } @techreport{BruecklEllerHableretal., author = {Br{\"u}ckl, Oliver and Eller, Johannes and Habler, Florian and Sator, Tobias and Sippenauer, Thomas and Strohmayer, Bernhard and Stuber, Johannes}, title = {Zuk{\"u}nftige Bereitstellung von Blindleistung und anderen Maßnahmen f{\"u}r die Netzsicherheit : Endbericht zum Dienstleistungsauftrag}, pages = {210}, abstract = {Der Zweck dieser Studie liegt darin, aufzuzeigen, welche neuen Herausforderungen f{\"u}r den sicheren Netzbetrieb durch den Ausbau der erneuerbaren Energien entstehen und wie diesen zu begegnen ist. Dabei sind praxisnahe Handlungsempfehlungen abzuleiten und Vorschl{\"a}ge f{\"u}r erforderliche Anpassungen zu unterbreiten. Gegenstand der Be-trachtungen sind die - Blindleistung, - Kurzschlussleistung, - Momentanreserve und der - Netzwiederaufbau. Im Fokus dieser Betrachtungen steht allerdings die Bereitstellung der Blindleistung. Konkret soll diese Studie dazu folgende drei Leitfragen beantworten: - Werden die Potenziale der vorhandenen Technologien schon heute kosteneffi-zient genutzt? - L{\"a}sst sich mehr Kosteneffizienz durch eine transparentere und mehr marktge-st{\"u}tzte Beschaffung erzielen? - Welche Anreize w{\"a}ren zu setzen, um die notwendige Mindesterzeugung konven-tioneller Kraftwerke zu reduzieren. Alle drei Leitfragen m{\"u}nden letztlich in der {\"u}bergeordneten Zielsetzung, eine h{\"o}chst-m{\"o}gliche Kosteneffizienz bei der Bereitstellung von SDL zu erlangen.}, language = {de} } @techreport{BruecklEllerAdeltetal., author = {Br{\"u}ckl, Oliver and Eller, Johannes and Adelt, Christian and Gschossmann, David and Kraus, Hermann and Rauch, Johannes and Sippenauer, Thomas and Susewind, Andreas and Wildfeuer, Matthias}, title = {Zuk{\"u}nftige Beschaffung von Blindleistung II : Endbericht zum Dienstleistungsauftrag}, pages = {143}, abstract = {Die vorliegende Studie befasst sich mit der Ermittlung des Bedarfs an Blindleistung f{\"u}r das gesamte deutsche Stromnetz auf Grundlage des NEP 2030 (2019) bis zum Jahr 2035. Die Verteilungsnetze werden dabei in ihrem Blindleistungsverhalten m{\"o}glichst realit{\"a}tsnah nachgebildet. Neben Maßnahmen zur Senkung des Blindleistungsbedarfs werden M{\"o}glichkeiten zur effizienten Deckung aufgezeigt. Dar{\"u}ber hinaus werden die mit der Blindleistungsbereitstellung verbundenen Kosten sowie die Methodik der Be-darfsermittlung beleuchtet.}, language = {de} } @inproceedings{PozzobonWeissMottoketal., author = {Pozzobon, Enrico and Weiß, Nils and Mottok, J{\"u}rgen and Matoušek, V{\´a}clav}, title = {Fuzzy fault injection attacks against secure automotive bootloaders}, series = {21th escar Europe : The World's Leading Automotive Cyber Security Conference (Hamburg, 15. - 16.11.2023)}, booktitle = {21th escar Europe : The World's Leading Automotive Cyber Security Conference (Hamburg, 15. - 16.11.2023)}, publisher = {Ruhr-Universit{\"a}t Bochum}, doi = {10.13154/294-10381}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:294-103817}, pages = {20}, abstract = {Secure embedded bootloaders are the trust anchors for modern vehicles' software. The secure software update process of ECUs is well-defined across the entire automotive industry. Every OEM has his own implementation, but follows the general software update process. This paper demonstrates code execution attacks by combining software and hardware weaknesses in secure automotive bootloaders. The attack can be performed entirely automated, no static code analysisis required. Random fault injection parameters were sufficient to obtain code execution in a reasonable time. All experiments were conducted with electromagnetic fault injection and without any hardware modifications of the targets. We successfully performed our attack on two entirely different gateway Electronic Control Units (ECUs) used in current vehicles (at the time of this research) from Volkswagen and BMW. As a result of this attack, consisting of a combination of a hardware and asoftware attack, the general secure software update process used in the automotive industry needs to be revised.}, language = {en} } @incollection{Sterner, author = {Sterner, Michael}, title = {WBGU Gutachten - zukunftsf{\"a}hige Bioenergie und nachhaltige Landnutzung}, series = {Biomasse \& Abfall : Emissionen mindern und R{\"u}ckst{\"a}nde nutzen (Verfahren \& Werkstoffe f{\"u}r die Energietechnik ; 5)}, booktitle = {Biomasse \& Abfall : Emissionen mindern und R{\"u}ckst{\"a}nde nutzen (Verfahren \& Werkstoffe f{\"u}r die Energietechnik ; 5)}, editor = {Faulstich, Martin and Mocker, Mario}, publisher = {Dorner Printconcept}, address = {Sulzbach-Rosenberg}, isbn = {9783981039146}, pages = {23 -- 28}, language = {de} } @phdthesis{Weiss, author = {Weiß, Nils}, title = {Security testing in safety-critical networks}, pages = {xiv, 126}, abstract = {The evolution of cars from mechanical systems to rolling computers creates new requirements for safety and security engineering. Nowadays, every vehicle contains a safety-critical real-time communication network to fulfill its function. Especially the increasing connectivity of automotive systems enlarged the attack surface for cyber-attacks. Safety engineering in this area is well understood and studied for decades, though the security engineering of these systems needs further research. This thesis introduces a black-box investigation process to analyze existing auto-motive systems and components and identifies security vulnerabilities in four different ECUs. Combined with a survey of published security research, vehicle-internal networks are identified as an extraordinary threat to the vehicle's safety and security. The outstanding automation capabilities of security tests for these networks are leveraged in the second part of this thesis. In order to create automated tools for automotive networks, a software foundation is necessary. As part of this thesis, a comprehensive open-source software framework for security testing in vehicular networks was developed and published. This aims to support further security research based on open and free software. Novel tools for the automated identification and exploration of attack surfaces in automotive diagnostic protocol implementations are created and evaluated. These tools allow the creation of comparable attack surface metrics through black-box scans of arbitrary ECUs. Automata learning and system state reverse-engineering techniques highly increase the exploration capabilities of the presented tools. The exploration algorithm is tested on thirteen different ECUs from independent OEMs. All gathered results are evaluated and discussed in the final part of this thesis. Finally, open issues and further research based on this contribution are discussed.}, language = {en} } @phdthesis{Grauvogl, author = {Grauvogl, Dominik}, title = {Multiphysikalische Auslegung einer fremderregten Synchronmaschine mit magnetischer Asymmetrie f{\"u}r einen Hochvolt-Achsantrieb}, editor = {Gerling, Dieter}, publisher = {Shaker Verlag}, address = {D{\"u}ren}, isbn = {9783844085532}, pages = {260}, abstract = {In der vorliegenden Arbeit wird eine fremderregte Synchronmaschine als Achsantrieb f{\"u}r ein Elektrofahrzeug entwickelt. Als Grundlage hierf{\"u}r dient ein bereits vorhandener Stator einer permanenterregten Synchronmaschine. Durch die Wiederverwendung des Stators ist eine maschinentypunabh{\"a}ngige Baukastenerweiterung in Form eines magnetfreien Rotors gegeben, wodurch die {\"o}konomischen und {\"o}kologischen Nachteile der Permanentmagnete ausgeschlossen sind. Bei der Auslegung des Rotors wird von Beginn an ein multiphysikalischer Entwicklungsansatz gew{\"a}hlt, mit dem der praxistaugliche Einsatz f{\"u}r den modularen Baukasten sichergestellt ist. Dabei ist die elektromagnetische Auslegung iterativ auf die mechanische Blechpaketfestigkeit, das thermische Verhalten und die magnetischen Ger{\"a}usche abgestimmt. In Kombination mit den gesetzten Restriktionen ergibt sich ein neuartiges asymmetrisches Polschuhdesign mit dem es m{\"o}glich ist, das geforderte Drehmoment mit gen{\"u}gend kleiner Welligkeit ohne eine Rotorschr{\"a}gung zu erreichen. Die Simulationsergebnisse sind durch die Vermessung eines aufgebauten Prototyps validiert und best{\"a}tigt. Ein abschließender Simulationsvergleich mit der baugleichen permanenterregten Synchronmaschine zeigt, dass die fremderregte Synchronmaschine hinsichtlich Performance, Wirkungsgrad und Ger{\"a}uschverhalten eine konkurrenzf{\"a}hige Alternative dazu ist.}, language = {en} } @phdthesis{Lalo, author = {Lalo, Erjola}, title = {Deployment designs for multi-core-real time systems}, edition = {1. Auflage}, publisher = {Universit{\"a}tsverlag Regensburg}, address = {Regensburg}, isbn = {978-3-86845-181-8}, doi = {10.21268/20240712-0}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:104-20240712-00000-7}, pages = {iii, 371}, abstract = {In modern embedded automotive systems, multi-core processors are used to provide higher execution performance and more computing capacity. However, they influence the way these systems are designed. Each change of the platform and application software results in an effort required to ensure and validate the functional correctness and timing requirements of these systems in a multi-core platform. For this reason, the use of the Logical Execution Time (LET) paradigm is advantageous for multi-core systems, as it satisfies these requirements by providing time and dataflow determinism, thereby reducing the development cycle and the impact of the platform in the design of such systems. To integrate LET into these systems, special mechanisms are required to satisfy its semantics. Therefore, this work focuses on buffering and scheduling techniques for resource efficient integration of LET in automotive systems. A buffering mechanism and an automatic schedule synthesis are proposed to guarantee functional correctness, timing requirements, and LET semantics and to reduce the increased demands of LET for memory and processor resources. A static and global buffering protocol is proposed, which compared to lock-based protocols has plausible memory needs and zero-communication overheads at the boundaries of LET intervals. The automatic schedule synthesis considers the Operating System (OS) overheads such that scheduling is optimized with respect to context-switching overheads caused by preemption. Buffering implements most of the LET semantics, but it provides no guarantee that tasks execute within their LET intervals. If scheduling is not designed to ensure that all tasks execute within their LET intervals, then functional correctness and LET semantics are violated. The manual design of a feasible schedule that satisfies the semantics and additional requirements of the application is inefficient and requires a significant amount of effort. Therefore, an automatic schedule generation approach for the Fixed-Priority Scheduling (FPS) and Time-Triggered Scheduling (TTS) is proposed. FPS is the widely used mechanism in the automotive domain because of its flexibility to handle dynamic changes of highly event-driven applications. Recently, TTS has attracted considerable attention in this domain to increase deterministic execution of tasks and efficient planning of processor resources. Therefore, schedule synthesis of FPS and TTS is provided to identify the efficiency, practicality, and resource optimization abilities of each approach for LET systems. To show the practicality of LET for industrial automotive systems, its integration into the software architecture of the classic platform of AUTomotive Open System Architecture (AUTOSAR) is described and a case study is conducted using a real world system.}, language = {en} } @phdthesis{Renner, author = {Renner, Sebastian}, title = {Secure Lightweight Authenticated Encryption for Critical Infrastructures in the Internet of Things}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:91-diss-20230922-1703211-1-0}, pages = {xix, 135}, abstract = {The cryptographic protection of transmitted data on resource-constraint IoT devices presents a difficult challenge. In this thesis, a benchmarking framework for the performance evaluation of lightweight encryption algorithms is introduced. It is analyzed, if and when novel encryption algorithms are more suitable for IoT use cases than the current standard. Besides comparing the sole performance, the cost for hardening the algorithms against side-channel analysis is discussed.}, language = {en} } @phdthesis{Thema, author = {Thema, Martin Jiř{\´i}}, title = {Process optimization for microbial biosynthesis of methane in a trickle-bed reactor for Power-to-Gas applications: the ORBIT-process}, isbn = {978-3-8440-7656-1}, url = {http://nbn-resolving.de/https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-150567}, pages = {XVIII, 211}, abstract = {This thesis identifes Power-to-Gas in general and biological CO2-methanation in trickle-bed reactors in particular as promising energy storage and sector coupling technology ready for application but with further optimization potential. It reviews the global status and development of Power-to-Gas technology as to be of exponentially growing importance in energy systems changing towards renewable power supply and analyzes optimization and standardization potential for biological CO2-methanation in tricklebed reactors deriving an improved methanation process. Process development and experiments on hydrodynamical and biological improvement of such a setup were performed, leading to an optimized combination of a packing and microorganisms in pure culture embedded in the new ORBIT-process. First experimental results give evidence of successful application of different optimization approaches implemented in a technical center scale setup.}, language = {en} } @inproceedings{RauchBruecklEngel, author = {Rauch, Johannes and Br{\"u}ckl, Oliver and Engel, Bernd}, title = {Optimal Reactive Power Planning by covering deficient voltage demands with additional reactive power sources using a sensitivity approach}, series = {NEIS 2023 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 4 - 5, 2023}, booktitle = {NEIS 2023 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 4 - 5, 2023}, editor = {Schulz, Detlef,}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-6134-0}, pages = {223 -- 230}, abstract = {The determination of the optimal location, types and size of additional required reactive power sources is a main interest of Reactive Power Planning (RPP) investigations and of this paper. The planning problem addresses the maintenance of voltage stability, which is an ancillary service in Germany, and can be formulated as a mixed-integer optimization prob-lem. The aim of this work is a techno-economically efficient coverage of the deficient steady state voltage deviation demands (VDD) by placing new reactive power sources with adequate size or extending the reactive power potential of existing sources. An optimization model is set up to solve the planning problem by using load flow voltage sensitivities, which quantify and evaluate the technical efficiency of new reactive power sources in relation to the present voltage deviation demands. Operating and investment costs are used as economic decision parameters. Within an application example, which is carried out with an exemplary transmission system, the solution of the planning problem is discussed.}, language = {en} } @inproceedings{HinterreiterBruecklRauch, author = {Hinterreiter, Marion and Br{\"u}ckl, Oliver and Rauch, Johannes}, title = {Challenges and Approaches for Long-Term Reactive Power Forecasting in Power Systems}, series = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, booktitle = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, editor = {Technische Universit{\"a}t M{\"u}nchen,}, publisher = {VDE Verlag}, isbn = {978-3-8007-6656-7}, pages = {109 -- 114}, abstract = {The transition from fossil fuels to renewable energy sources is driving profound changes across all voltage levels of the electrical grid, altering active power (P) as well as reactive power (Q) behavior. This transformation involves a shift from predominantly top-down, unidirectional electricity flows to bidirectional and increasingly complex flow patterns, fundamentally altering the operation and utilization of power systems. Many countries are already reporting notable changes in their transmission grid Q. This can lead to increased costs for grid expansion and compensation equipment, as well as grid losses. To minimize these losses and ensure grid stability and efficiency, understanding and forecasting Q long-term becomes essential. This paper addresses the challenges of long-term (1-20 years) Q forecasting in general by analyzing Q behavior in grids, the main influencing grid parameters, and reviewing existing forecasting approaches. It evaluates the applicability of these approaches and highlights current research gaps and trends. By focusing on this underexplored area, the paper aims to support the development of more advanced and reliable long-term Q forecasting techniques.}, language = {en} } @inproceedings{HinterreiterBruecklRauch, author = {Hinterreiter, Marion and Br{\"u}ckl, Oliver and Rauch, Johannes}, title = {Methodology for long-term reactive power forecasts of medium-voltage grids}, series = {NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 - 16, 2025}, booktitle = {NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 - 16, 2025}, editor = {Schulz, Detlef}, publisher = {VDE Verlag}, isbn = {978-3-8007-6633-8}, pages = {218 -- 223}, abstract = {Understanding and assessing the long-term behavior of reactive power is crucial for power system planning and invest-ment decisions. This is particularly growing relevant for the lower voltage-grid levels, which are gaining importance due to significant changes in grid behavior, operational strategies, energy generation and consumption patterns. Currently, standardized methodologies for forecasting reactive power in medium-voltage grids are lacking, creating a gap in research and practical applications. To optimize grid investments and expansions, informed decisions based on reliable research and accurate forecasts are essential. This paper presents a methodology for long-term reactive power forecasting in me-dium-voltage grids, introducing a new approach to account for low- and medium-voltage grid interactions while address-ing common challenges like limited available grid data and scenario framework definition. The aim of the forecast is the future reactive power behaviour of a medium-voltage-grid at the high-voltage side of the high-voltage to medium-voltage transformer. The medium-voltage-level is modelled using a grid model approach, while low-voltage grids are being mod-elled using generic distribution grids. A 209-bus medium-voltage-grid model is used as an application example and to provide two exemplary use cases for a reactive power forecast for 2045.}, language = {en} } @inproceedings{StadlerKrausBrueckl, author = {Stadler, Andreas and Kraus, Hermann and Br{\"u}ckl, Oliver}, title = {Proposing an Optimization Model for a techno-economic Evaluation of Energy Storage Systems}, series = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, booktitle = {PESS 2025 - IEEE Power and Energy Student Summit, October 08 - 10, 2025 in Munich, Germany}, editor = {Technische Universit{\"a}t M{\"u}nchen,}, publisher = {VDE}, isbn = {978-3-8007-6656-7}, pages = {97 -- 102}, abstract = {During the global energy crisis in 2022, electricity prices increased drastically. This lead, together with an overall higher price volatility to possibly higher electrical energy storage system (ESS) profitability. To test if the investment in an ESS can now be more profitable, an approach for a techno-economic evaluation of ESS is presented in this paper, using an optimization algorithm to determine the optimal way of covering a load flow profile with electricity trading products on the electricity market with and without the use of an energy storage system. The cost differences between using or not using the storage system are assumed to be the profits of the ESS, which must exceed the (interest-bearing) investment costs over its lifetime. The correct way of operation of the optimization model is validated and several storage sizes and capacities as well as several years of the electricity market data was analyzed, once with a perfect forecast of all prices of the electricity trading products and once with a forecast based on the previous years purchasing strategy. The results show that, using the prognosis and a 2 \% p.a. interest rate, only the storage combinations for 2.5 MWh/ 2.5 MW and 1 MWh/ 1 MW show profitability in 2023, whereas 2017 and 2020 show no profitability.}, language = {en} } @inproceedings{UhlSchamelAchhammeretal., author = {Uhl, Julius and Schamel, Marco and Achhammer, Anton and Sterner, Michael}, title = {Sustainable Steel Production in the Desert: Economic and Technical Assessment of a Hydrogen-Powered Steel Plant in Mauritania}, series = {2025 IEEE PES/IAS PowerAfrica, 28 September - 02 October 2025, Cairo}, booktitle = {2025 IEEE PES/IAS PowerAfrica, 28 September - 02 October 2025, Cairo}, publisher = {IEEE}, doi = {10.1109/PowerAfrica65840.2025.11289120}, pages = {6}, abstract = {The global steel industry is a major contributor to climate change and faces challenges in achieving a carbon-neutral production, hinging on the availability of cost-effective hydrogen produced by renewable energy. Mauritania, with its exceptional solar and wind resources, offers some of the most competitive conditions globally for hydrogen production. Instead of focusing on hydrogen exports, this study explores the technical feasibility and economic viability of establishing a renewable-powered steel plant in Mauritania, utilizing the country's abundant iron ore reserves. The findings suggest that sustainably produced steel in Mauritania could be cost-competitive with current European prices. With ongoing declines in investment costs for emerging renewable technologies, Mauritania has the potential to become one of the world's most cost-effective steel producers.}, language = {en} } @article{SchiekSolntsevNeshev2025, author = {Schiek, Roland and Solntsev, Alexander S. and Neshev, Dragomir N.}, title = {Measurement of the cubic nonlinear susceptibility in lithium niobate}, series = {Optical Materials Express}, volume = {15}, journal = {Optical Materials Express}, number = {5}, publisher = {Optica Publishing Group}, issn = {2159-3930}, doi = {10.1364/OME.557516}, pages = {1100 -- 1117}, year = {2025}, abstract = {We measured the cubic nonlinear susceptibility tensor elements ( χ(3)) for polarization along the primary crystallographic axis in titanium-indiffused lithium niobate waveguides, assessed through self-phase modulation using picosecond-duration pulses at telecommunication wavelengths. A dominant, highly temperature- and wavelength-dependent contribution from a cascaded second-order nonlinearity is observed. Through careful extraction of the cascaded effect, we quantify the intrinsic third-order susceptibility tensor elements as χ(3) zzzz(ω; ω, ω, -ω) = (5.2 ± 1.3) × 10-21 m2 V2 and χ(3) xxxx(ω; ω, ω, -ω) = χ(3) yyyy(ω; ω, ω, -ω) = (3.6 ± 0.8) × 10-21 m2 V2 . These measurements underscore the substantial impact of the cascaded nonlinearity in enhancing the effective cubic nonlinearity in lithium niobate and offer precise values essential for the design of nonlinear photonic devices.}, language = {en} } @misc{Kriegl, author = {Kriegl, Raphael}, title = {Sessile droplet fitting (Version v1.0b) [Data set]}, doi = {10.5281/zenodo.7464158}, language = {en} } @inproceedings{HammerMottokKrauseetal., author = {Hammer, Pascal and Mottok, J{\"u}rgen and Krause, Veronika and Probst, Tobias}, title = {Approach for High-Performance Random Number Generators for Critical Systems}, series = {Proceeding of the 12th European Congress on Embedded Real Time Software and Systems (ERTS2024) , Toulouse, 11-12 June 2024}, booktitle = {Proceeding of the 12th European Congress on Embedded Real Time Software and Systems (ERTS2024) , Toulouse, 11-12 June 2024}, doi = {10.5281/zenodo.14848832}, pages = {9}, abstract = {In times of digitalization, the encryption and signing of sensitive data is becoming increasingly important. These cryptographic processes require large quantities of high-quality random numbers. Which is why a high-performance random number generator (RNG) is to be developed. For this purpose, existing concepts of RNGs and application standards are first analyzed. The proposed approach is to design a physical true random number generator (PTRNG) with a high output of random numbers. Based on this, the development begins with the analog part of the RNG, the noise signal source and a suitable amplifier for the analog noise signal. Therefore, a special noise diode from Noisecom and an amplifier from NXP were chosen and analyzed in different measurements. From the results of the measurements, it can be concluded that both components are suitable for use in the RNG.}, language = {en} } @misc{Grabinger, author = {Grabinger, Lisa}, title = {Data of a systematic literature research on eye tracking in software engineering [Data set]}, doi = {10.5281/zenodo.11279180}, abstract = {How did the data collection work? By systematic research in the IEEE Xplore and ACM digital libraries we extracted 125 papers. Further details on the procedure can be found in the journal paper. What data is provided? In this repository you can find the extracted data, i.e., file data.xlsx.}, language = {en} }