TY - JOUR A1 - Lechl, Michael A1 - de Meer, Hermann A1 - Fürmann, Tim T1 - A stochastic flexibility calculus for uncertainty-aware energy flexibility management JF - Applied Energy N2 - The increasing share of volatile renewables in power systems requires more reserves to balance forecast errors in renewable generation and power fluctuations. In contrast, common reserves such as gas-fired power plants are phased out, impeding the procurement of sufficient reserves. Alternative reserves, particularly on the demand side, such as battery storage systems, also exhibit some degree of freedom to deviate from their scheduled operating point to supply or consume more or less power, thus providing a flexibility potential. However, demand-side flexibility potentials are generally subject to uncertainties, and so is the generation of volatile renewables. The challenge is incorporating the uncertainties on both sides to procure sufficient (uncertain) flexibility potential in advance. Considering uncertainty is important to avoid additional, drastic measures in real-time to balance generation and demand, such as curtailing renewable generation or load shedding. This work presents a stochastic flexibility calculus that provides an indicator for computing the risk of insufficient flexibility potentials or, conversely, guarantees for sufficient flexibility potentials. Thus, the stochastic flexibility calculus contributes to overcoming the challenge of procuring sufficient flexibility potentials in renewable-based systems. An evaluation based on real data is performed using an example of a renewable energy community consisting of households equipped with photovoltaic power plants and battery storage systems. The newly introduced stochastic flexibility calculus computes the number of households that must operate their battery storage systems flexibly to balance forecast errors locally. The results show that the forecast method significantly influences this number. Some numerical results appear unexpected, as too many flexibility-friendly households can negatively impact the aggregated household flexibility potential. KW - Stochastic network calculus KW - Probabilistic flexibility guarantees KW - Power system flexibility KW - Renewable energy community KW - Uncertainty modeling KW - Battery storage system Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19233 VL - 2025 IS - 379 ER - TY - JOUR A1 - Huebenthal, Sandra T1 - Gedächtnis trifft Einleitung : ein neuer Blick auf alte Fragen JF - New Testament Studies N2 - Ausgehend von der kulturwissenschaftlichen Forschung zu Familienalben und deren Gemeinsamkeiten mit dem Neuen Testament lädt dieser Beitrag dazu ein, darüber nachzudenken, was sich verändert, wenn wir die Fragen der Einführung in das Neue Testament durch die Brille der Theorie des sozialen Gedächtnisses betrachten. Aufbauend auf Forschungsergebnissen der Oral History und kulturwissenschaftlichen Gedächtnistheorie wird argumentiert, dass die allgemeine Einleitung in den Bereich des kulturellen Gedächtnisses und die spezielle Einleitung in den Bereich des sozialen/kollektiven Gedächtnisses fällt. Beide sind durch den Floating Gap getrennt, was die vielfach wahrgenommenen Veränderungen in der ersten Hälfte des zweiten Jahrhunderts erklärt. Im nächsten Schritt wird ein Modell, das auf dem Dreigenerationengedächtnis, der Generational Gap (nach einer Generation), der Floating Gap (nach 3-4 Generationen) und den ersten Generationen von Jesus-Anhängern aufbaut, mit Vorschlägen zur Datierung neutestamentlicher Bücher aus der Einleitungswissenschaft ins Gespräch gebracht. Es zeigt sich, dass die vor und nach dem Generational Gap verwendeten Genres je unterschiedliche Eigenschaften haben, die den Erwartungen an Medien des sozialen und kollektiven Gedächtnisses entsprechen. Der Beitrag schließt mit allgemeinen Fragen zu Medien und Medienwandel im Neuen Testament, d.h. Mündlichkeit und Schriftlichkeit, identische Texte und Textkritik, dem Kanon als primärem Kontext, der Ausweitung des Geltungsbereichs sowie fluiden Gattungen, und kommt zu dem Schluss, dass kulturwissenschaftliche Gedächtnistheorie in der Tat neue Perspektiven für die Einleitungswissenschaft bietet. N2 - Starting with cultural-scientific research on family albums and what they have in common with the New Testament, this paper invites us to reflect upon what changes when we look at questions of New Testament introduction through the lens of social memory theory. Building on the research of Oral History and Cultural Memory Theory, it is argued that general introduction (allgemeine Einleitung) falls into the realm of cultural memory, while special introduction (spezielle Einleitung) falls into the realm of social/collective memory, and that both are divided by the floating gap. This, in turn, explains some of the developments of the first half of the second century. In the next step, the paper combines a model building on the three-generational-memory, the generational gap (after one generation), the floating gap (after three to four generations), and the first generations of Jesus-followers, with conventional suggestions for dating New Testament books and draws first conclusions from this synopsis. It turns out that the genres used before and after the generational gap exhibit different characteristics, which fit scholarly expectations for media of social and collective memory. The paper closes with general questions about media and media changes in the New Testament, i.e. orality and scribality, identical texts and textual criticism, the canon as the primary context, the extension of the scope and genre-fluidity, concluding that social memory theory does indeed provide new perspectives for New Testament introduction. KW - introduction to the New Testament KW - social memory theory KW - cultural memory KW - orality KW - media KW - genre KW - textual criticism KW - canon Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19277 VL - 70 (2024) IS - 2 SP - 131 EP - 148 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Goerigk, Marc A1 - Kurtz, Jannis T1 - Data-driven prediction of relevant scenarios for robust combinatorial optimization JF - Computers & Operations Research N2 - We study iterative constraint and variable generation methods for (two-stage) robust combinatorial optimization problems with discrete uncertainty. The goal of this work is to find a set of starting scenarios that provides strong lower bounds early in the process. To this end we define the Relevant Scenario Recognition Problem (RSRP) which finds the optimal choice of scenarios which maximizes the corresponding objective value. We show for classical and two-stage robust optimization that this problem can be solved in polynomial time if the number of selected scenarios is constant and NP-hard if it is part of the input. Furthermore, we derive a linear mixed-integer programming formulation for the problem in both cases. Since solving the RSRP is not possible in reasonable time, we propose a machine-learning-based heuristic to determine a good set of starting scenarios. To this end, we design a set of dimension-independent features, and train a Random Forest Classifier on already solved small-dimensional instances of the problem. Our experiments show that our method is able to improve the solution process even for larger instances than contained in the training set, and that predicting even a small number of good starting scenarios can considerably reduce the optimality gap. Additionally, our method provides a feature importance score which can give new insights into the role of scenario properties in robust optimization. KW - Robust optimization KW - Two-stage robust optimization KW - Data-driven optimization KW - Machine learning for optimization Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19207 SN - 1873-765X VL - 2025 IS - 174 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rehbein, Malte A1 - Escobari, Belen A1 - Fischer, Sarah A1 - Güntsch, Anton A1 - Haas, Bettina A1 - Matheisen, Giada A1 - Perschl, Tobias A1 - Wieshuber, Alois A1 - Engel, Thore T1 - Quantitative and qualitative data on historical vertebrate distributions in Bavaria 1845 JF - scientific data N2 - Archival collections contain an underutilized wealth of biodiversity data, encapsulated in government files and other historical documents. In 1845, the Bavarian government conducted a comprehensive national survey on the occurrence of 44 selected vertebrate species across the country. The detailed expert responses from 119 forestry offices, totalling 520 handwritten pages, have been preserved in the Bavarian State Archives. In this study, we digitized, annotated, geographically referenced, and published these historical records, making them widely available as data for research and conservation planning. Our dataset, openly accessible through the Global Biodiversity Information Facility (GBIF) and Zenodo, contains 5,467 species occurrence records from 1845. Besides the binary presence/absence data, we have also published the original textual survey responses, which contain rich qualitative information, such as species abundances, population trends, habitats, forest management practices, and human-nature relationships. This information can be further processed and interpreted to address a range of questions in historical and contemporary ecology. KW - Biodiversity KW - Forestry KW - History KW - Interdisciplinary studies Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-2506092137360.319993244702 VL - 2025 PB - Springer Nature CY - Berlin ER - TY - JOUR A1 - Bouri, Elie A1 - Sokhanvar, Amin A1 - Kinateder, Harald A1 - Çiftçioğlu, Serhan T1 - Tech titans and crypto giants : mutual returns predictability and trading strategy implications JF - Journal of International Financial Markets, Institutions and Money N2 - This study examines the directional return predictability between the technology sector of U.S. stock market and three major cryptocurrencies (Bitcoin, Ethereum, and Dogecoin). Using daily data from August 7, 2015, to February 8, 2024, and the cross-quantilogram approach in both static and dynamic settings, the results reveal significant positive predictability in the stock market–cryptocurrency nexus. The technology sector, semiconductors subsector, and Nvidia Corporation exert predictive power over cryptocurrency returns and vice versa across several quantiles and lags. When controlling for the impact of other financial variables, namely, U.S. dollar and U.S. treasury markets, the return predictability holds, especially for the two largest cryptocurrencies, Bitcoin and Ethereum, which reflects their importance and tighter connections with the U.S. technology sector. A trading strategy based on the results of the cross-quantilograms outperforms a benchmark strategy (i.e., always long position in either stocks or cryptocurrency), which underlines the practical implications of our main findings, particularly in terms of the significant return interactions between U.S. technology/semiconductors stocks and large cryptocurrencies. KW - Bitcoin KW - Ethereum KW - Dogecoin KW - Nvidia KW - U.S. technology and semiconductor stocks KW - S&P500 index KW - Cross-quantilogram and return predictability across quantiles Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19259 SN - 1873-0612 VL - 2025 IS - 99 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ryzhova, Anna A1 - Toepfl, Florian T1 - The Consequences of Evidence- Versus Non-Evidence-Based Understandings of the “Truth”: How Russian Speakers in Germany Negotiate Trust in Their Transnational News Environments JF - The International Journal of Press/Politics (ISSN: 1940-1620) N2 - Extant research on migrants’ media use and trust has delivered mixed evidence on whether, and in which ways, migrants stay loyal to their homeland news media and/or develop trust in host-society media, particularly when the narratives of the two types of media clash. To advance this strand of research, this study scrutinizes how an audience group with migration background, who lived the first part of their lives under authoritarian rule but then relocated to a democracy, negotiates trust in their multilingual, transnational news environments. Specifically, we conducted semi-structured interviews with forty-two Russian-speaking first-generation migrants living in Germany in 2021. As we find, distinct understandings of the concept of “truth” played a pivotal role in how our participants negotiated trust in their transnational news environments. We distinguish broadly two understandings of “truth”: (1) “truth” as a category grounded in factual evidence and (2) “truth” as a non-evidence based category grounded in values, emotions, or identities. Illustrative for the second understanding, some participants felt a strong moral obligation to believe Kremlin-sponsored media as they perceived these organizations as representing their homeland, independently of whether their news coverage was factually accurate or not. The two understandings of “truth” also affected how and where participants sought for what they considered the “truth.” In the “Discussion” section, we argue that particularly the non-evidence-based truth-understandings formulated by our participants, and the ensuing truth-seeking strategies are conducive to the reach and persuasive impact of Kremlin-sponsored content among Russian speakers living abroad. KW - - KW - Russian speakers KW - news trust KW - truth KW - transnational audiences KW - Germany Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-16795 SN - 1940-1612 SN - 1940-1620 VL - 30 IS - 1 SP - 326 EP - 345 PB - SAGE Publications CY - Los Angeles, CA ER - TY - JOUR A1 - Baumann, Jakob A1 - Pfretzschner, Matthias A1 - Rutter, Ignaz T1 - Parameterized complexity of vertex splitting to pathwidth at most 1 JF - Theoretical Computer Science N2 - Motivated by the planarization of 2-layered straight-line drawings, we consider the problem of modifying a graph such that the resulting graph has pathwidth at most 1. The problem Pathwidth-One Vertex Explosion (POVE) asks whether such a graph can be obtained using at most 𝑘 vertex explosions, where a vertex explosion replaces a vertex 𝑣 by deg(𝑣) degree-1 vertices, each incident to exactly one edge that was originally incident to 𝑣. For POVE, we give an FPT algorithm with running time 𝑂(4𝑘 ⋅ 𝑚) and an 𝑂(𝑘2) kernel, thereby improving over the 𝑂(𝑘6) kernel by Ahmed et al. [2] in a more general setting. Similarly, a vertex split replaces a vertex 𝑣 by two distinct vertices 𝑣1 and 𝑣2 and distributes the edges originally incident to 𝑣 arbitrarily to 𝑣1 and 𝑣2. Analogously to POVE, we define the problem variant Pathwidth-One Vertex Splitting (POVS) that uses the split operation instead of vertex explosions. Here we obtain a linear kernel and an algorithm with running time 𝑂((6𝑘 + 12)𝑘 ⋅ 𝑚). This answers an open question by Ahmed et al. [2]. Finally, we consider the problem Π-VertexSplitting (Π-VS), which generalizes the problem POVS and asks whether a given graph can be turned into a graph of a specific graph class Π using at most 𝑘 vertex splits. For graph classes Π that can be dfined in monadic second-order graph logic (MSO2), we show that the problem Π-VS can be expressed as an MSO2 formula, resulting in an FPT algorithm for Π-VS parameterized by 𝑘 if Π additionally has bounded treewidth. We obtain the same result for the problem variant using vertex explosions. [2] R. Ahmed, S.G. Kobourov, M. Kryven, An FPT algorithm for bipartite vertex splitting, in: P. Angelini, R. von Hanxleden (Eds.), Graph Drawing and Network Visualization -30th International Symposium, GD 2022, in: Lecture Notes in Computer Science, vol.13764, Springer, 2022, pp.261--268. KW - Vertex splitting KW - Pathwidth 1 KW - 2-layer drawing Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19195 SN - 1879-2294 VL - 2024 IS - 1021 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Łatuszyński, Krzysztof A1 - Rudolf, Daniel T1 - Convergence of hybrid slice sampling via spectral gap JF - Advances in Applied Probability N2 - It is known that the simple slice sampler has robust convergence properties; however, the class of problems where it can be implemented is limited. In contrast, we consider hybrid slice samplers which are easily implementable and where another Markov chain approximately samples the uniform distribution on each slice. Under appropriate assumptions on the Markov chain on the slice, we give a lower bound and an upper bound of the spectral gap of the hybrid slice sampler in terms of the spectral gap of the simple slice sampler. An immediate consequence of this is that the spectral gap and geometric ergodicity of the hybrid slice sampler can be concluded from the spectral gap and geometric ergodicity of the simple version, which is very well understood. These results indicate that robustness properties of the simple slice sampler are inherited by (appropriately designed) easily implementable hybrid versions. We apply the developed theory and analyze a number of specific algorithms, such as the stepping-out shrinkage slice sampling, hit-and-run slice sampling on a class of multivariate targets, and an easily implementable combination of both procedures on multidimensional bimodal densities. KW - Slice sampler KW - spectral gap KW - geometric ergodicity Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:739-opus4-19264 SN - 1475-6064 VL - 56 (2024) IS - 4 SP - 1440 EP - 1466 PB - Cambridge University Press CY - Cambridge ER - TY - THES A1 - Pirwitz, Anne T1 - Migrationsfilme als ‚kritische Heimatfilme‘? BT - eine interdisziplinäre Untersuchung semantischer Räume und Chronotopoi der Migration im neuen rumänischen Film (1996–2022) N2 - Seit dem Zusammenbruch des Kommunismus ist die Anzahl im Ausland arbeitender Rumän*innen stark angestiegen. Inzwischen leben fast 20 % der Bevölkerung jenseits der Landesgrenzen. Transnationale Familien­strukturen mit in Rumänien zurückgelassenen Kindern oder Eltern und pluri-lokale Lebensweisen der Migrant*innen sind in kürzester Zeit zu einem alltäglichen Phänomen der rumänischen Gesellschaft geworden. Die Auswirkungen dieser Migration sind von gesamtgesellschaftlicher Relevanz und finden daher immer wieder Eingang in Literatur, Musik und Film. Diese Medien werden dabei von realen Ereignissen inspiriert, greifen aktuelle Diskurse auf und konstruieren eigene fiktionale Wirklichkeiten. Dabei vermitteln sie bestimmte Weltbilder und bieten verschiedene Sichtweisen auf die von ihnen verhandelten Themen an. Zwischen dem Ende der kommunistischen Diktatur 1989 und 2022 entstanden 52 rumänische fiktionale Kurz- und Spielfilme, die explizit Migration ins Zentrum ihrer erzählten Geschichten stellen. Der vorliegende Band untersucht, auf welche Weise die rumänische Arbeitsmigration im postkommunistischen Film verarbeitet wird, welches Bild der rumänischen Heimat und des ‚Westens‘ vermittelt wird, wie diese Räume durch filmische Mittel ästhetisch konstruiert werden und ob es sich bei diesen Werken um eine neue Form des ‚kritischen Heimatfilms‘ handelt. KW - Rumänien KW - Film KW - Migration Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-2409191636377.506847991255 PB - Akademische Verlagsgemeinschaft München CY - München ER - TY - BOOK ED - Atuguba, Raymond ED - Hennemann, Moritz ED - Boshe, Patricia ED - Dei-Tutu, Sena Afua T1 - African data protection laws BT - regulation, policy, and practice T3 - Global and comparative data law (edited by Moritz Hennemann; Lea Katharina Kumkar; Linda Kuschel; Björn Steinrötter) KW - Afrika KW - Datenschutz Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-2404231639273.359651152421 VL - 2024 IS - volume 3 PB - Walter de Gruyter CY - Berlin/Boston ER - 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 -