Recent Submissions
Methodik zur Orchestration kooperativer Smart Services in der Smart Factory
(Stuttgart : Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA, 2025) Stahl, Tobias; Bauernhansl, Thomas (Prof. Dr.-Ing.)
Um den Herausforderungen des 21. Jahrhunderts zu begegnen, müssen sich produzierende Unternehmen an die externe Komplexität des Marktes anpassen. Ein Enabler für die notwendigen Anpassungen ist die Digitalisierung. Im industriellen Umfeld werden die Potenziale der Digitalisierung im Rahmen von Industrie 4.0 verortet. Industrie 4.0 wird in drei Dimensionen unterteilt: Smart Factory, Smart Products und Smart Services. In der Smart Factory wollen Fabrikbetreiber ihre Prozesse kontinuierlich optimieren. Mithilfe von Smart Services können Optimierungspotenziale identifiziert und realisiert werden. In der Praxis erfolgt die Umsetzung von Smart Services zunehmend in Wertschöpfungsnetzwerken mit mehreren rechtlich selbstständigen Akteuren. Mangelndes Vertrauen, Kooperationsbereitschaft, Skalierbarkeit, Gewinnverteilung und ungünstige Rahmenbedingungen erschweren die Umsetzung von Smart Services. Die nachhaltige Kooperation der beteiligten Akteure ist ein kritischer Erfolgsfaktor.
In dieser Arbeit wird eine Methodik vorgestellt, die erstmalig die Kostenersparnis aus Smart Services transparent auf alle Akteure verteilt, sodass die Kooperation für alle Beteiligten vorteilhaft ist. Die Methodik koordiniert die Zusammenarbeit der Akteure im Wertschöpfungsnetzwerk der Smart Factory. Maschinen- und Komponentenlieferanten werden in die Pflicht genommen, die für Smart Services notwendigen Daten aus ihren Betriebsmitteln und Fertigungsprozessen in der erforderlichen Datenqualität zur Verfügung zu stellen. Der Serviceanbieter wird mithilfe der Daten befähigt, Optimierungspotenziale für den Fabrikbetreiber zu realisieren. Um die Zusammenarbeit zwischen den Akteuren langfristig zu sichern, beteiligt der Serviceanbieter die Datenanbieter auf Grundlage der zur Verfügung gestellten Daten am Umsatz.
Die entwickelte Methodik wird auf ein Fallbeispiel angewendet. Die vorgeschlagenen Werkzeuge und Vorgehensweisen sind mit Akteuren dieses Netzwerks validiert. Die Erfassung und Verteilung von Kostenersparnissen führt nach Meinung der elf Validierungsteilnehmer zu einer höheren Kooperationsbereitschaft zwischen den Akteuren.
Anwendungen für Renewal Prozesse in der stochastischen Thermodynamik : Semi-Markov Prozesse als Konzept und Werkzeug für zustandsbasierte und übergangsbasierte thermodynamische Inferenz
(2025) Ertel, Benjamin; Seifert, Udo (Prof. Dr.)
Understanding the crystallization mechanism of organic-inorganic perovskite films
(2025) Zuo, Weiwei; Saliba, Michael (Prof. Dr.)
Optical detection of the density-wave instability in the kagome metal KV3Sb5
(2022) Uykur, Ece; Ortiz, Brenden R.; Wilson, Stephen D.; Dressel, Martin; Tsirlin, Alexander A.
Coexisting density-wave and superconducting states along with the large anomalous Hall effect in the absence of local magnetism remain intriguing and enigmatic features of the AV3Sb5 kagome metals (A = K, Rb, Cs). Here, we demonstrate via optical spectroscopy and density-functional calculations that low-energy dynamics of KV3Sb5 is characterized by unconventional localized carriers, which are strongly renormalized across the density-wave transition and indicative of electronic correlations. Strong phonon anomalies are prominent not only below the density-wave transition, but also at high temperatures, suggesting an intricate interplay of phonons with the underlying electronic structure. We further propose the star-of-David and tri-hexagon (inverse star-of-David) configurations for the density-wave order in KV3Sb5. These configurations are strongly reminiscent of p-wave states expected in the Hubbard model on the kagome lattice at the filling level of the van Hove singularity. The proximity to this regime should have intriguing and far-reaching implications for the physics of KV3Sb5 and related materials.
Flanking sequences influence the activity of TET1 and TET2 methylcytosine dioxygenases and affect genomic 5hmC patterns
(2022) Adam, Sabrina; Bräcker, Julia; Klingel, Viviane; Osteresch, Bernd; Radde, Nicole E.; Brockmeyer, Jens; Bashtrykov, Pavel; Jeltsch, Albert
TET dioxygenases convert 5-methylcytosine (5mC) preferentially in a CpG context into 5-hydroxymethylcytosine (5hmC) and higher oxidized forms, thereby initiating DNA demethylation, but details regarding the effects of the DNA sequences flanking the target 5mC site on TET activity are unknown. We investigated oxidation of libraries of DNA substrates containing one 5mC or 5hmC residue in randomized sequence context using single molecule readout of oxidation activity and sequence and show pronounced 20 and 70-fold flanking sequence effects on the catalytic activities of TET1 and TET2, respectively. Flanking sequence preferences were similar for TET1 and TET2 and also for 5mC and 5hmC substrates. Enhanced flanking sequence preferences were observed at non-CpG sites together with profound effects of flanking sequences on the specificity of TET2. TET flanking sequence preferences are reflected in genome-wide and local patterns of 5hmC and DNA demethylation in human and mouse cells indicating that they influence genomic DNA modification patterns in combination with locus specific targeting of TET enzymes.
A systematic review of explainable AI methods for transformers in software engineering
(2024) Denizoglu, Meltem
BACKGROUND: Transformer-based models have revolutionized artificial intelligence (AI) applications in software engineering (SE), supporting tasks such as code generation, debugging, and documentation. However, their opaque decision-making processes limit trust and usability. Explainable AI (XAI) methods aim to address these issues by improving interpretability, but their integration into transformers for SE remains underexplored. Existing XAI techniques face challenges in aligning with developer workflows and adapting to complex transformer architectures.
OBJECTIVE: This study aims to provide an overview of the current state of research on XAI methods for transformer models in SE, focusing on their applicability, limitations, and empirical evidence supporting their effectiveness. By identifying key challenges and research gaps, the study explores how XAI can be better integrated into SE workflows to enhance transparency, usability, and trust in AI-driven tasks.
METHODS: Following the guidelines by Kitchenham and Charters, a systematic literature review was conducted using IEEE Xplore, ACM Digital Library, and Google Scholar. A total of 32 studies were selected through automated searches and snowballing. Research questions were formulated to evaluate existing XAI methods, their suitability for large language models (LLMs), and their impact on SE tasks.
RESULTS: Attention-based, gradient-based, and model-agnostic techniques were identified as key categories of XAI methods. The SHapley Additive exPlanations (SHAP) method emerged as the most empirically supported approach for LLMs in SE. However, limitations in scalability, usability, and interpretability persist across methods. Significant gaps were also identified in the application of XAI methods to transformer-based AI models, including dataset biases, the lack of standardized evaluation metrics, and insufficient practical validation.
CONCLUSION: XAI methods hold great potential for enhancing transparency, trust, and productivity in AI-driven SE tasks. However, their real-world application is constrained by practical challenges and theoretical gaps. Future research should prioritize empirical studies, user-centric designs, and scalable methods tailored to transformer models in SE. Structured evaluation metrics and benchmarks are essential for advancing the field.
Lumineszierende Flüssigkristalle auf Basis multiresonanter Bor-dotierter Heteroaromaten
(2025) Knöller, Julius A.; Laschat, Sabine (Prof. Dr.)
Design for reliability in advanced technologies using machine learning
(2024) Klemme, Florian; Amrouch, Hussam (Prof. Dr.-Ing.)
This thesis focuses on the standard cell library, which is one of the core entities in the digital circuit design flow, to demonstrate the challenges and opportunities of advanced technology nodes. The standard cell library serves as a technology interface between the foundry and the circuit designer, enabling automatic mapping of high-level circuit descriptions to the technology of the foundry through the process of logic synthesis. In the past decade, the standard cell library has been continuously adapted to keep up with the demands of shrinking process nodes. This includes, e.g., the integration of more accurate timing models, process variation, or signal integrity for cross-talk and noise in the circuit. This thesis takes this development to the next level and presents approaches to bring machine learning and transistor self-heating into the standard cell library.
Spatiotemporal stop-and-go dynamics of the mitochondrial TOM core complex correlates with channel activity
(2022) Wang, Shuo; Findeisen, Lukas; Leptihn, Sebastian; Wallace, Mark I.; Hörning, Marcel; Nussberger, Stephan
Single-molecule studies can reveal phenomena that remain hidden in ensemble measurements. Here we show the correlation between lateral protein diffusion and channel activity of the general protein import pore of mitochondria (TOM-CC) in membranes resting on ultrathin hydrogel films. Using electrode-free optical recordings of ion flux, we find that TOM-CC switches reversibly between three states of ion permeability associated with protein diffusion. While freely diffusing TOM-CC molecules are predominantly in a high permeability state, non-mobile molecules are mostly in an intermediate or low permeability state. We explain this behavior by the mechanical binding of the two protruding Tom22 subunits to the hydrogel and a concomitant combinatorial opening and closing of the two β-barrel pores of TOM-CC. TOM-CC could thus represent a β-barrel membrane protein complex to exhibit membrane state-dependent mechanosensitive properties, mediated by its two Tom22 subunits.
ER stress-induced cell death proceeds independently of the TRAIL-R2 signaling axis in pancreatic β cells
(2022) Hagenlocher, Cathrin; Siebert, Robin; Taschke, Bruno; Wieske, Senait; Hausser, Angelika; Rehm, Markus
Prolonged ER stress and the associated unfolded protein response (UPR) can trigger programmed cell death. Studies in cancer cell lines demonstrated that the intracellular accumulation of TRAIL receptor-2 (TRAIL-R2) and the subsequent activation of caspase-8 contribute significantly to apoptosis induction upon ER stress. While this might motivate therapeutic strategies that promote cancer cell death through ER stress-induced caspase-8 activation, it could also support the unwanted demise of non-cancer cells. Here, we therefore investigated if TRAIL-R2 dependent signaling towards apoptosis can be induced in pancreatic β cells, whose loss by prolonged ER stress is associated with the onset of diabetes. Interestingly, we found that elevated ER stress in these cells does not result in TRAIL-R2 transcriptional induction or elevated protein levels, and that the barely detectable expression of TRAIL-R2 is insufficient to allow TRAIL-induced apoptosis to proceed. Overall, this indicates that apoptotic cell death upon ER stress most likely proceeds independent of TRAIL-R2 in pancreatic β cells. Our findings therefore point to differences in ER stress response and death decision-making between cancer cells and pancreatic β cells and also have implications for future targeted treatment strategies that need to differentiate between ER stress susceptibility of cancer cells and pancreatic β cells.