TY - JOUR ED - Lampert, Claudia ED - Kühn, Jessica ED - Wiedel, Fabian ED - Fehr, Ada ED - Domdey, Paulina ED - Thiel, Kira T1 - Zeitgemässe Methoden der Kinder- und Jugendmedienforschung N2 - MedienPädagogik : Zeitschrift für Theorie und Praxis in der Medienbildung Themenheft 60: Zeitgemässe Methoden der Kinder- und Jugendmedienforschung Inhalte: Malin Fecke, Ada Fehr, Daniela Schlütz Die Mobile Experience Sampling Methode (MESM) in der Kinder- und Jugendmedienforschung André Weßel ‹Jeden Abend Instagram, TikTok, YouTube› - Das digitale Medientagebuch als qualitative Forschungsmethode zur Untersuchung des Medienhandelns junger Menschen Thorsten Naab, Ruth Wendt, Alexandra Langmeyer-Tornier Messung mütterlicher Medienerziehung für interaktive und nicht-interaktive Medien Thorsten Naab, Moritz Abraham Wie ein Spielzeug zum Helfer in Kinderbefragungen werden kann Sophie Mayen, Anne Reinhardt , Claudia Wilhelm Instrumente zur Messung von jugendlicher Mediennutzung Paulina Domdey, Katrin Potzel Medientagebücher als Teil sequenzieller Triangulation in der qualitativen Forschung Franziska Koschei, Lena Schmidt, Susanne Eggert, Andreas Dertinger, Michaela Kramer, Rudolf Kammerl Forschung mit Grundschüler:innen Jan Pfetsch, Felix Paschel, Cora Bieß, Ingrid Stapf Forschungsethik und Kinderrechte Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-15162 VL - 2024 IS - 60 PB - OAPublishing Collective Genossenschaft CY - Zürich ER - TY - JOUR A1 - Hofstadler, Julian T1 - Optimal convergence rates of MCMC integration for functions with unbounded second moment JF - Journal of Applied Probability N2 - We study the Markov chain Monte Carlo estimator for numerical integration for func- tions that do not need to be square integrable with respect to the invariant distribution. For chains with a spectral gap we show that the absolute mean error for L^p functions, with p ∈ (1, 2), decreases like n^(1/p)−1 , which is known to be the optimal rate. This improves currently known results where an additional parameter δ > 0 appears and the convergence is of order n^((1+δ)/p)−1 . KW - Markov chain KW - Monte Carlo KW - spectral gap KW - absolute mean error Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19310 VL - 62 (2025) IS - 3 SP - 1069 EP - 1075 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Stocker, Armin A1 - Alshawish, Ali A1 - Bor, Martin A1 - Vidler, John A1 - Gouglidis, Antonios A1 - Scott, Andrew A1 - Marnerides, Angelos A1 - De Meer, Hermann A1 - Hutchison, David T1 - An ICT architecture for enabling ancillary services in Distributed Renewable Energy Sources based on the SGAM framework JF - Energy Informatics (2520-8942) N2 - Smart Grids are electrical grids that require a decentralised way of controlling electric power conditioning and thereby control the production and distribution of energy. Yet, the integration of Distributed Renewable Energy Sources (DRESs) in the Smart Grid introduces new challenges with regards to electrical grid balancing and storing of electrical energy, as well as additional monetary costs. Furthermore, the future smart grid also has to take over the provision of Ancillary Services (ASs). In this paper, a distributed ICT infrastructure to solve such challenges, specifically related to ASs in future Smart Grids, is described. The proposed infrastructure is developed on the basis of the Smart Grid Architecture Model (SGAM) framework, which is defined by the European Commission in Smart Grid Mandate M/490. A testbed that provides a flexible, secure, and low-cost version of this architecture, illustrating the separation of systems and responsibilities, and supporting both emulated DRESs and real hardware has been developed. The resulting system supports the integration of a variety of DRESs with a secure two-way communication channel between the monitoring and controlling components. It assists in the analysis of various inter-operabilities and in the verification of eventual system designs. To validate the system design, the mapping of the proposed architecture to the testbed is presented. Further work will help improve the architecture in two directions; first, by investigating specific-purpose use cases, instantiated using this more generic framework; and second, by investigating the effects a realistic number and variety of connected devices within different grid configurations has on the testbed infrastructure. KW - Ancillary services KW - SGAM KW - DRES KW - Smart Grid KW - Engineering KW - Information and Computing Sciences Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-2022071721175548518669 SN - 2520-8942 VL - 2022 IS - 5 PB - Springer International Publishing CY - Berlin ER - TY - JOUR A1 - Köstler, Verena A1 - Wolff, Monika-Sybille ED - Sabitzer, Barbara ED - Hörmann, Corinna T1 - Promoting digital competencies in pre-service teachers : the impact of integrative learning opportunities JF - Education Sciences N2 - Offering learning opportunities for developing digital competencies in pre-service teacher education remains challenging despite its growing importance in preparing future educators. This study investigates the effectiveness of integrative learning opportunities, called “digitally enhanced courses”, which combine subject-specific and digital learning objectives. Implemented at a German university (2019–2023). These courses aimed to promote digital competencies required for technology-supported teaching. Using survey data from 312 pre-service teachers, the research examined students’ self-assessed digital competencies, technology acceptance, and value–cost assessments through multiple measurement instruments, including TPACK scales, the Technology Acceptance Model, and Expectancy–Value beliefs. Results revealed significantly higher self-assessed digital competencies in private contexts compared to teaching situations. While mere course participation showed no significant impact, both the frequency and number of attended courses positively correlated with higher self-assessed digital skills across all TPACK dimensions. Additionally, increased technology acceptance and higher success expectations were associated with enhanced teaching-related digital competencies. The findings emphasize that the effectiveness of digitally enhanced courses is contingent upon systematic implementation and student engagement, highlighting the need for structured curricular integration of digital competency development in teacher education through comprehensive, spiral-curriculum approaches rather than isolated interventions. However, this study’s reliance on self-reported data may introduce social desirability and subjective estimation bias, and its cross-sectional design limits causal interpretations. Future research should employ longitudinal approaches to examine competency development over time, incorporate objective performance-based assessments, and explore how instructional design and curricular integration influence digital competency acquisition. KW - pre-service teacher education KW - digitally enhanced courses KW - TPACK KW - technology acceptance KW - expectancy value KW - curriculum integration Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-16854 SN - 2227-7102 VL - 15 (2025) IS - 3 PB - MDPI CY - Basel ER - TY - JOUR T1 - Universitätsbibliothek Passau: Jahresbericht 2024 N2 - Jahresbericht der Universitätsbibliothek Passau für das Jahr 2024. T3 - Jahresbericht der Universitätsbibliothek Passau - 2024 Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19641 CY - Passau ER - TY - JOUR T1 - Universitätsbibliothek Passau: Jahresbericht 2023 N2 - Jahresbericht der Universitätsbibliothek Passau für das Jahr 2023. T3 - Jahresbericht der Universitätsbibliothek Passau - 2023 Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-15083 CY - Passau ER - TY - CHAP A1 - Ungruhe, Christian A1 - Agergaard, Sine T1 - Postcareer precarity : occupational challenges among former West African footballers in Northern Europe T2 - Sports in Africa : past and present (Ohio University Press Open Access Books. 42; https://ohioopen.library.ohio.edu/oupress/42/) N2 - When Benoît Assou-Ekotto’s former coach Harry Redknapp announced that the Cameroonian international had decided to end his professional football career and become an adult movie actor, the story generated astonishment and amusement in social media networks and received widespread attention from the mass media. Although the French-born footballer denied the story’s validity shortly afterward, claiming Redknapp was joking, it entertained football fans and the wider public during the spring of 2017. However, while this was one of the very few occasions on which an African footballer’s postcareer trajectory was a matter of public debate, it also revealed that former African professional footballers’ whereabouts, occupations, and living conditions are widely unknown and remain an underresearched topic. KW - Football migration Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-14897 SN - 978-0-8214-4696-6 N1 - "Sports in Africa : past and present" ist unter einer CC-BY-NC-ND-4.0-Lizenz erschienen und unter https://ohioopen.library.ohio.edu/oupress/42/ verfügbar. Die Veröffentlichung des Einzelbeitrags erfolgt mit freundlicher Erlaubnis des Verlags. SP - 190 EP - 203 PB - Ohio University Press CY - Athens ER - TY - THES A1 - Hagen, Pamina T1 - The 2008 Beijing Olympic Games as a City and Nation Branding Tool: An Interdisciplinary Analysis of the Image of International Opinion Leaders N2 - This dissertation examines the 2008 Beijing Olympic Games as a tool of city and nation branding, analyzing their role within China's broader soft power strategy and their impact on international perceptions of Beijing and China. Drawing from urban geography, political geography, international relations, and marketing theory, the study explores how mega-events contribute to the construction of national identity and global image. Using a mixed-methods approach, the research combines qualitative interviews with 16 international diplomats in Beijing and an online survey of 40 foreign journalists who lived and worked in China during the Olympiad. The analysis focuses on two dimensions of image: the city of Beijing and the nation of China. The findings indicate that the 2008 Summer Olympic Games did not fundamentally alter China's international image. While the event successfully projected an image of modernization, efficiency, and confidence, pre-existing concerns about political control and human rights persisted. For Beijing, the Olympics enhanced its visibility as a global city but also highlighted tensions between its traditional identity and its modern aspirations. The media's framing played a decisive role in shaping these perceptions. Overall, the study concludes that the Beijing Olympics functioned as a significant yet limited instrument of soft power. They reinforced China's global presence and urban development goals but fell short of transforming its international reputation. The research contributes to understanding how mega-events operate as strategic tools of geopolitical communication and branding in the context of globalization. KW - Beijing 2008 Summer Olympic Games KW - Nation Branding KW - City Branding KW - International Image KW - Public Diplomacy Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19052 ER - TY - THES A1 - Danner, Julian T1 - SAT Solving Using XOR-OR-AND Normal Forms and Cryptographic Fault Attacks N2 - The Boolean satisfiability problem (SAT) lies at the core of computational logic and has found many applications in verification, cryptography, and artificial intelligence. While conflict-driven SAT solvers (CDCL) excel on large industrial instances, they struggle with XOR-rich instances arising frequently in cryptanalysis, due to the inefficiency of CNF encodings of linear constraints. Conversely, algebraic approaches can work with linear XOR constraints naturally but fail to scale to relevant sizes. Bridging these complementary paradigms with a focus on cryptographic problems is at the heart of this thesis. On one hand, this dissertation advances SAT solving by introducing the XOR-OR-AND normal form (XNF) as a generalization of the conjunctive normal form (CNF), where literals are replaced by XOR chains of literals. This allows for a native representation of XOR constraints. We generalize the CDCL architecture to the richer language of XNFs. The underlying reasoning based on the proof system SRES which is shown to be exponentially stronger than classical resolution. An implementation demonstrates competitive performance and often surpasses state-of-the-art algebraic and logic solvers on random and cryptographic benchmarks. Furthermore, we prove that every XNF formula can be converted in polynomial time to a formula in 2-XNF, enabling a graph-based approach similar to 2-SAT. Building on this, we propose advanced in- and pre-processing techniques, and construct a simple DPLL-based solving framework. Our implementation, 2-Xornado, outperforms modern algebraic and logic solving approaches on many random and some structured cryptographic problems. On the other hand, we apply combined algebraic and logical techniques to cryptanalysis of stream ciphers. We introduce a formal guess-and-determine (GD) framework using a logical abstraction of the information flow in the internal state. From an algebraic point of view, we can then find optimal GD attacks utilizing a Gröbner basis. As a case study, we apply this method to aid in the construction of novel fault attacks on the ciphers KCipher-2 and Enocoro-128v2. Using ad hoc methods combining algebraic and logical approaches, we show that both ciphers are vulnerable to active side-channel attacks under rather weak fault models. Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19171 ER - TY - THES A1 - Kling, Julia T1 - Social Networking Sites as Intermediaries of Authoritarian State Propaganda: How Facebook and VK Disseminated Predominantly Kremlin-Friendly Political Content Before and During Russia’s Full-Scale Invasion of Ukraine N2 - Previous research on Russia’s use of social networking sites to influence foreign audiences has primarily focused on US-based platforms, such as Twitter and Facebook, the activities of Russia’s “troll farms”, as well as Russia’s foreign broadcasters, RT and Sputnik, and their audiences. By contrast, little research has examined the global reach of Russia’s state-aligned domestic news content, specifically on US- and Russia-based social networking sites that significantly differ in the level of the Kremlin’s control over information flows, and how the activities of novel Russian disinformation production organizations support this reach. In my dissertation, I addressed these gaps in the extant research literature in the fields of political communication, social media, and Russia studies in four distinct research papers focusing on the reach of and engagement with Russian-speaking political content, including Russia’s domestic news content, and the activities of ANO Dialog, Russia’s novel disinformation production organization with close links to the Russian government, on US-based Facebook and Russia-based VK. To do so, I used innovative qualitative, quantitative, and computational research methods to create knowledge on Russia’s informational influence on the two platforms before and after the start of Russia’s full-scale invasion of Ukraine in February 2022. The findings highlight that, despite differing levels of Kremlin control, both of the social networking sites studied functioned as conduits for the dissemination of Russian-speaking, predominantly Kremlin-friendly political content, including state-aligned domestic news. This content reached audiences both within Russia and abroad in the lead-up to and during the full-scale war in Ukraine. While VK primarily served Russia’s users, Facebook disseminated Russia’s state-aligned news mostly to audiences outside Russia, particularly in former Soviet countries, in the lead-up to the invasion. During the war, Facebook continued to host critical perspectives on Russia’s war crimes, in contrast to VK, where such content was blocked. However, Facebook was banned in Russia in March 2022, limiting domestic access to dissenting views. With the war ongoing as of May 2025 and organizations such as ANO Dialog intensifying their efforts to influence both domestic and foreign audiences on platforms such as VK and Facebook, it is likely that Russia will further strengthen its information control. KW - social networking site KW - Russia KW - propaganda KW - platform governance Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19601 ER - TY - THES A1 - Prummer, Michael T1 - Asset Tokenization and Authentication in the Industrial Metaverse N2 - The Industrial Revolution is a crucial development step in human history that started three centuries ago and is still ongoing. It continually influences and shapes the globalized world. Today, industries account for 20% of carbon dioxide emissions worldwide and require more than a third of global energy consumption. Current problems, such as climate change, increasing waste, and pollution, require simultaneous optimization across all industrial domains, infrastructure, and systems as they depend on each other. The global industry faces the immense challenges of providing for a surging world population expected to peak in the mid-2080s with 10.4 billion people, as reported by the United Nations. Hence, industries are expected to become less resource-intensive, sustainable, and more resilient to disrupted supply chains while producing for a growing population for the next decades. The Fourth Industrial Revolution, or Industry 4.0 (I4.0), started around 2010 and is still an ongoing transformation of industrial processes towards digitalization, creating smart factories referring to the digital data integration of the entire manufacturing cycle. I4.0 is incredibly information-intensive and requires immense data to simulate and predict essential operations based on a digital shadow of the factory, a so-called digital twin. The Metaverse is considered a digitalization megatrend merging digital and physical worlds, creating immersive experiences and new opportunities for interaction and innovation across various sectors and industries. The vision of the Metaverse promotes interconnected and interoperable real-time 3D virtual worlds that can be frictionlessly traversed while sustaining ownership of one's assets under a self-sovereign identity in a decentralized environment without platform lock-ins to a specific ecosystem. Therefore, the Metaverse creates an immersive parallel reality with collective virtually shared spaces for entertainment, social interactions, education, and a new working environment. The Industrial Metaverse synthesizes Metaverse concepts with current industrial automation, such as I4.0, to deepen the digital-physical convergence by interconnecting internal and external systems to enable decision-making and predictions based on significantly broader knowledge. An Industrial Metaverse factory is entirely mirrored to integrate digital twins of all types of equipment, assets, and other entities that can communicate vertically and horizontally, as well as the knowledge about relevant external systems and industrial core sectors. Through the comprehensive data integration of the Industrial Metaverse, AI-driven applications can predict future events, reducing system and hardware failures. Furthermore, the interconnected virtual environments create a meta-ecosystem for global collaboration, providing spaces for solving complex problems such as engineering and product design tasks, simulation of product twins, and reduced development time and costs. The connected industrial ecosystems create a token-based digital economy for exchanging data, assets, and services cross-metaverse connecting isolated data silos. Sharing digital twin resources and services with other systems enables new innovative applications and growing ecosystems. The theoretical part of this thesis defines the essential characteristics and key technologies of the Industrial Metaverse to derive a reference architecture for a decentralized system of systems, outlining the fundamental Industrial Metaverse building blocks. Interoperable data exchange, access management, and system communication are critical challenges. Especially interoperability of assets such as 3D files that come in different formats and identities must be ensured to move between virtual environments. The unique fusion of technologies leverages interconnected digital twins in the context of immersion, interaction, and collaboration for secure, autonomous-governed, decentralized industrial applications. Hence, the Industrial Metaverse requires the possibility of exchanging assets, products, and services across all systems in a secure manner. Distributed ledger technology enables tamper-proof transactions of assets and value in a decentralized token economy. Therefore, we investigate the feasibility of current tokenization methods for industrial assets, in particular, Printed Circuit Board (PCB) designs and 3D models. We contribute methods to create unique fingerprints of PCB designs to enable their exchange in the token economy. We investigate how to bind files in different formats and quality representations to the same token. A robust multi-file binding based on the copper layers of a PCB design was achieved by calculating an adaptive perceptual hash of all files. The adaptive perceptual hash was evaluated against numerous tamperings of the routing layout of a PCB, showing decent resistance to layout changes. The resulting adaptive perceptual hash can be used as an additional identification attribute in a tokenized asset. Furthermore, assets must be authenticatable and verifiable by marketplaces, manufacturers, and other participants to create trust in a decentralized environment. While assets can be tampered with to manipulate, for example, cryptographic hashes that link the file to the token, perceptual hashes can compute a perceived or functional similarity of two objects instead of the plain file integrity. Without the possibility of verifying and protecting intellectual property, mass adoption of the Metaverse and Industrial Metaverse is unlikely. Therefore, we contribute to detecting tampering attacks on 3D models by introducing a 3D perceptual hash that is robust to a set of mesh manipulations, enabling the trusted exchange and authentication of 3D data in the Metaverse. KW - 3D Perceptual hash KW - Industrial Metaverse Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19566 ER - TY - THES A1 - Ellinger, Simon T1 - On optimal error rates for strong approximation of stochastic differential equations with irregular drift coefficients N2 - In this dissertation we study strong approximation of stochastic differential equations (SDEs) with irregular drift coefficients at the final time point or globally in time by methods that use only finitely many evaluations of the driving Brownian motion. We show the optimality of well-known methods, such as the Euler-Maruyama scheme or a transformed Milstein scheme, for classes of piecewise Lipschitz continuous, Hölder continuous and Sobolev regular drift coefficients. To do this, we derive the optimal error rates for the different classes of irregular drift coefficients. Furthermore, we show that the solution of an SDE with piecewise Hölder continuous drift coefficient has a regular local density, which is used in the proofs of the lower bounds. KW - Complexity KW - Error rates KW - Stochastic differential equations KW - Non-Lipschitz drift coefficient KW - Strong approximation KW - Lower error bounds Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19634 ER -