汉堡大学

Overset grid methods handle complex geometries by overlapping simpler, geometry-fitted grids to cover the original, more complex domain. However, ensuring their stability-particularly at high orders-remains a theoretical challenge: although overset grid methods perform robustly in extensive practical use, general stability proofs are not available. In this work, we address this gap by developing a discrete counterpart to the recent well-posedness analysis of Kopriva, Gassner, and Nordstr & ouml;m for continuous overset domain initial-boundary-value problems. To this end, we introduce the novel concept of sub-cell summation-by-parts (SBP) operators. These discrete derivative operators mimic integration by parts at a sub-cell level. By exploiting this sub-cell SBP property, we develop provably conservative and energy-stable overset grid methods for fixed one-dimensional overset domains that do not change with time or under grid refinement, providing a step toward stability proofs for overset grid methods based on the energy method.

Context Balancing food security and biodiversity conservation is a major challenge in the Galapagos Islands, where agriculture overlaps with vulnerable native ecosystems. Objective We evaluated the potential of local agricultural production in Santa Cruz, Galapagos, to increase food self-sufficiency while conserving native vegetation under future population growth, and assessed the effects of land use change on invasive plant cover. Methods We developed the Galapagos Land Use (GAL-LU) model, a farm-level multi-objective optimization model integrating agricultural production, nutrient self-sufficiency, farm income, land-use allocation, and invasive plant dynamics. The model combined biophysical, economic, nutritional, and land-cover data for 182 farms in Santa Cruz. Scenarios were evaluated under projected population growth from 2022 to 2100 and different nutritional targets. Results and conclusions Under current yields and a high population growth, most nutrient requirements could be met without further native vegetation loss. Iron and polyunsaturated fatty acid sufficiency reached about 67%, while all other nutrients achieved or exceeded 100% of recommended intake levels. Achieving these targets increased cropland area by 2137 ha (47%), pasture area by 560 ha (60%), and silvopasture area by 581 ha (111%). Invasive plant cover declined by approximately 1140 ha (33%), including reductions of Cedrela odorata (−545 ha; −40%) and Psidium guajava (−528; −31%). More balanced diets required larger cropland expansion than energy-focused diets, indicating synergies between local food production, invasive plant control, and native ecosystem conservation. Significance This study presents the first integrated optimization framework linking food self-sufficiency, farm income, and invasive plant control in an island food system.

Digital banking platforms operate as complex service ecosystems involving banks, technology providers, payment infrastructures, and regulators, creating challenges for monitoring service performance, operational risk, and accountability. Understanding how customers evaluate these dimensions remains important to digital service management and technology-adoption research. This study develops a theory-guided large language model–structural equation modeling (LLM–SEM) framework that transforms unstructured customer reviews into theoretically grounded indicators for behavioral analysis. Drawing on UTAUT-3, perceived risk theory, and attribution theory, the framework uses structured chain-of-thought prompting with LLaMA 3.1-8B to extract indicators of service quality, operational risk, customer experience, behavioral outcomes, and actor attribution from customer reviews of leading smart banking applications in Saudi Arabia. The resulting indicators are examined using PLS-SEM and attribution-oriented text mining. Performance expectancy, trust, and hedonic motivation exhibited strong associations with usage experience, which was strongly associated with behavioral intention; behavioral intention, in turn, was strongly associated with recommendation intention. System performance and service delay risks emerged as salient operational-risk correlates of behavioral intention, whereas financial risk showed a limited association. Customers predominantly associated positive and negative service outcomes with the focal platform rather than with banks or regulators. This pattern supports the concept of platform-centered accountability, whereby operational responsibility may be distributed across ecosystem actors while perceived accountability is concentrated on the primary service interface, positioning the platform in customer narratives as the central ecosystem orchestrator and focal point of accountability. Multi-inference analysis, combined model–prompt analysis using GPT-5.6 Sol, and survey-based validation provide complementary evidence of methodological stability and the robustness of the findings. The study contributes to service operations, platform ecosystem, technology-adoption, and AI-assisted behavioral research by showing how theory-guided LLMs can complement established measurement approaches as scalable semantic measurement instruments for transforming customer-generated content into operational and behavioral insights. The findings also underscore the importance of service operations monitoring, ecosystem governance, and perceived platform accountability within FinTech ecosystems.

The document that forms the basis of documentary projects is often the result of a collaborative effort—a dialogue between witness and artist, witness and journalist, witness and historian. The process of collaborating on textual documents confronts us with important questions of authorship, authenticity, and the politics and ethics of writing and publishing. The chapter will look at how coproduction manifests itself in documentary texts, how it is acknowledged, and how theories of collaborative writing are applied to documentary texts. Particular attention will be paid to the categories of voice, collectivity, and authenticity in collaborative writing. Ales’ Adamovich and Daniil Granin’s book on the siege of Leningrad will serve as a case study to illustrate the affordances of collaborative writing for documentary aesthetics in a controlled discursive environment.

Optical time projection chambers (OTPCs) are well suited for applications that require the highest spatial resolution for particle track reconstruction. The MIGDAL experiment uses a glass GEM-based OTPC and observes a systematic excess in both the intensity and width of particle tracks in its optical readout, when compared with charge readout simulations. One hypothesis is that scintillation light produced inside a GEM hole during the avalanche propagates through the GEM substrate and exits neighboring holes. We present lab measurements testing this hypothesized optical broadening effect in three types of GEM substrates: glass, ceramic, and FR4. Our observations quantify this optical broadening and demonstrate it to be strongest in glass GEMs. Additionally, we use Geant4 simulations to both reproduce our observations and quantify optical broadening effects in realistic charge avalanches. Applying our glass GEM effects to simulated particle tracks yields increases of track intensity and widths by up to around 26