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Work, Technology, and the Paradox of Non-Use: Ethnographic Insights into AI Implementation

Jay Duane Jones — Fri, 12 Jun 2026 12:03:10 +0200

Artificial intelligence (AI) systems are increasingly implemented in organizations in pursuit of efficiency and improved knowledge management, yet day-to-day engagement often remains limited. This cumulative dissertation examines how AI systems can become consequential for organizing when engagement is selective rather than routine, asking how limited or selective engagement with AI systems can produce meaningful changes in coordination practices and organizational structure. Building on a micro-level, structuring-oriented view of technology in work practices and an ethnographic approach, this dissertation develops a cumulative process account across three manuscripts. The first establishes the conceptual and methodological groundwork for making implementation effects visible when they are not apparent through observed use. The second introduces pragmatic non-adoption to show how selective bypassing can be locally rational and organizationally sustainable under situational constraints, as actors rely on interpersonal, analog, and selectively digital coordination resources to stabilize workflow. The third coins invisible integration to explain how AI can become structurally consequential with negligible use, as its presence changes meanings, expectations, and discourse that redirect coordination over time. Taken together, the dissertation theorizes the paradox of non-use: limited or selective engagement is not the absence of implementation unfolding in practice but a mechanism through which coordination is sustained and organizational structuring emerges over time.

The Use of Artificial Intelligence as an Anti-Corruption Tool and Its Impact on Employees' (Un)Ethical Behavior

Katharina Scheer — Fri, 12 Jun 2026 11:53:08 +0200

Corruption is one of the greatest challenges of our time, and AI is viewed as a promising tool in the fight against corruption. To provide insights relevant to a successful implementation of such tools in organizations, this thesis aims to examine how employees perceive an algorithmic versus a human anti-corruption agent, and how, and under what conditions, their use influences employees’ unethical behavior, specifically employee dishonesty, like corruption, and employees’ ethical behavior, specifically employee whistleblowing. This is done by conducting four empirical studies drawing on the cognitive trust model, research on algorithm appreciation and aversion, whistleblowing, the bystander effect, and the standard economic model of rational and selfish human behavior. The first study examines how trustworthy employees perceive an algorithmic versus a human ethics agent and how the trustworthiness perceptions – perceived integrity and competence – influence employees’ preference for an algorithmic instead of a human ethics agent for dishonesty detection. Thereby, it scrutinizes the moderating role of employees’ moral attentiveness. The second study investigates how and under what conditions the use of an algorithmic rather than a human ethics agent influences employee dishonesty, considering employees’ perceived detection probability as a mediator and employees’ domain-specific technical knowledge as a moderator. Investigating employees’ perceived responsibility as a mediator, the third study examines how and under what conditions the use of an algorithmic versus a human ethics agent influences employee whistleblowing. It investigates the clarity of indications of dishonesty and employees’ perceived competence of an algorithmic compared to a human ethics agent as moderators. Finally, the fourth study complements the third by investigating how and under what conditions the type of anti-corruption agent (AI-based software vs. human) influences employees’ whistleblowing likelihood. It focuses on the same mediator as the third study and on the clarity of indications of corrupt behavior as one moderator, but adds three moral potency factors as individual moderators, and applies another methodological approach. Overall, this thesis focuses on the perspectives of employees who are directly affected by algorithmic tools’ decisions (i.e., second parties) or are informed about the use and may be affected in the future (i.e., third parties), rather than on employees who interact with these tools (i.e., first parties). Results revealed that employees perceived an algorithmic ethics agent as more trustworthy than a human agent and preferred algorithmic dishonesty detection. Employees’ perceived integrity and competence of an algorithm positively influenced their preference for an algorithmic instead of a human ethics agent for dishonesty detection. Moral attentiveness moderated the positive relationship between employees’ perceived competence of an algorithmic ethics agent and their preference, such that this relationship was significant only among employees with low moral attentiveness. Furthermore, using an algorithmic rather than a human ethics agent resulted in no differences in employees’ perceived detection probability or employee dishonesty in a high-honesty context, likely due to the internal moral costs of dishonesty. Findings on employee whistleblowing showed that using an AI-based software or an algorithmic ethics agent instead of a human counterpart did not per se lead to a diffusion of responsibility for whistleblowing to an algorithmic bystander. However, when employees perceived an algorithmic ethics agent as more competent than a human one, and indications of dishonesty were unclear, they were more likely to shift responsibility for whistleblowing to an algorithm and, in turn, engaged in less whistleblowing. Taken together, the findings indicate that while employees tend to trust AI-based anti-corruption tools and are therefore likely to support their adoption, their use does not appear to increase dishonesty in organizational contexts characterized by high internal moral costs. However, organizations should remain mindful of the potential suppression of employee whistleblowing. This thesis advances research on algorithm appreciation and aversion, particularly regarding AI as an anti-corruption tool, as well as on cognitive trust in AI, whistleblowing, the bystander effect, and integrated approaches that examine how both rational cost-benefit analysis and external and internal motives shape (dis)honest behavior.

Climate change and European forests: Impacts, adaptation, and consequences for aesthetics

Paul Averbeck — Thu, 11 Jun 2026 16:50:20 +0200

This dissertation investigates how European forests are affected by climate change, how forest practitioners perceive and respond to these impacts, and how adaptation and reforestation strategies shape the visual aesthetics of forest landscapes. By combining biophysical evidence, qualitative practitioner insights, expert assessments, and public preference assessments, the thesis develops a comprehensive understanding of forests as socio-ecological systems under increasing climate stress. Across Europe, the 2018–2022 drought period caused widespread vitality loss, intensified pest outbreaks, and substantial tree cover decline, with Central Europe experiencing the most severe impacts. Damage patterns differed markedly among regions, yet even typically resilient or high-altitude forests showed signs of stress. Persistent effects in climatically average years highlight legacy effects of drought and heat events. These findings underline Europe’s high forest vulnerability and the need for region-specific adaptation strategies. Forest practitioners widely acknowledge drought as the dominant threat to forest health, citing its effects on mortality, regeneration, and pest susceptibility. Although there is broad consensus on the need to increase species and structural diversity for adaptation, substantial differences in preferred measures persist across practitioner groups. Economically oriented practitioners tend to favor active, conifer-based management, whereas those prioritizing protection and recreation advocate for native species and more naturalistic approaches. These contrasting strategies stem not from differing views on climate impacts but from divergent management philosophies and value orientations, illustrating that adaptation is as much a social negotiation as it is the management of ecological systems. The dissertation further shows that climate change adaptation measures profoundly influence the aesthetic quality of forests—an often neglected but socially important dimension. Structural attributes such as tree size, height variation, understory density, and species composition strongly shape visual appeal. Measures that enhance structural diversity—mixed stands, multi-layered canopies, increased naturalness—tend to improve aesthetics. In contrast, interventions like leaving residues, using protective tubes, or uniform reforestation can temporarily reduce scenic quality, though many negative effects diminish as forests mature. Public preference analysis demonstrates significant temporal dynamics: reforestation strategies that appear unattractive shortly after implementation may become appealing decades later, while options that are initially appealing may lose their attractiveness over time. This highlights the importance of evaluating aesthetic outcomes across the full forest development cycle rather than at a single moment in time. Taken together, the findings underscore that climate adaptation in forestry must integrate ecological risks, practitioner perspectives, and public aesthetic values. By recognizing forests as co-evolving socio-ecological systems, the dissertation provides a foundation for adaptation strategies that are not only ecologically effective but also socially acceptable and visually appreciated—essential conditions for sustaining multifunctional forests in a changing climate.

What Does Digital Well-Being Mean for School Development? A Theoretical Review with Perspectives on Digital Inequality

Philipp Michael Weber; Rudolf Kammerl; Mandy Schiefner-Rohs — Tue, 09 Jun 2026 11:34:57 +0200

As digital transformation progresses, schools are increasingly confronted with psychosocial challenges such as technostress, digital overload, and unequal participation in digital (learning) environments. This article investigates the conceptual relevance of digital well-being for school development, particularly in relation to social inequality. Despite growing attention, the term remains theoretically underdefined in educational research—a gap addressed through a theory-driven review. Drawing on a systematic search, 25 key studies were analyzed for their conceptual understanding and refinement of digital well-being, with a focus on educational relevance. Findings suggest that digital well-being constitutes a multidimensional state shaped by individual, media-related, and socio-structural factors. It emerges when individuals are able to successfully manage the demands of digital environments and is closely linked to digital inequality—particularly in terms of access, usage practices, and the resulting opportunities for participation and health promotion. Since the institutional role of schools has thus far received limited attention, this article shifts the focus toward schools as key arenas for negotiating digital norms and practices and calls for an equity-sensitive and health-conscious perspective on school development in the context of digitalization. In doing so, digital well-being is repositioned as a pedagogical cross-cutting issue that requires coordinated efforts across all levels of the education system, highlighting that equitable digital transformation in schools depends on a critical reflection of power asymmetries within society and educational institutions. The article concludes by advocating for the systematic integration of digital well-being into school development processes as a way to support inclusive digital participation and to foster a health-oriented digital school culture.

Fate of grape pomace-derived plant phenols in soil during use as organic fertilizer

Sullivan Sadzik — Tue, 09 Jun 2026 06:28:14 +0200

The grapevine is one of the most commonly cultivated plants in the world. Every year, over $30\times 10^{6}\,\text{t}$ are processed into wine worldwide. After pressing the grapes, $9-30\,\%$ of the fresh weight remain in the form of grape pomace. Grape pomace is a heterogeneous mixture of grape skins, seeds and pulp. Its exact composition varies greatly depending on the vintage, grape variety and processing method. In addition to fiber, monosaccharides and proteins, grape pomace is rich in plant phenols. In Germany, the most common method of disposal is to spread it on vineyards as organic fertilizer. To date, it remains unclear what processes the phenolic compounds from the pomace undergo when introduced into the soil and what effects they have on the soil. Therefore, in this study, grape pomace from three red and three white grape varieties from the Palatinate region was examined for its properties as an organic fertilizer in vineyards. In the first step, the composition of the dry grape pomace was determined. The pomace from white grape varieties had a glucose and fructose content of $110-180\,\text{g/kg}$ each, while the pomace from red grape varieties had a content of $3-19\,\text{g/kg}$ each. The nitrogen content of all pomaces ranged between $11-27\,\text{mg/kg}$. The mineral content of the pomace ranged as follows: Na: $680-1000\,\text{mg/kg}$, K: $12000-20000\,\text{mg/kg}$, Mg: $560-830\,\text{mg/kg}$, Ca: $1911-5300\,\text{mg/kg}$. The total phenolic content of the pomace from white grape varieties was $17-23\,\text{g GAE/kg}$ and that from red grape varieties was $45-48\,\text{g GAE/kg}$. The total tannin content of the pomace from white grape varieties was $17-23\,\text{g GAE/kg}$, and that of red grape varieties was $45-48\,\text{g PCE/kg}$. The main components of the phenolic profile of pomace from white grape varieties were catechin, epicatechin, and B-type procyanidins. The main components of the phenolic profile of pomace from red grape varieties were glucosides of malvidin, peonidin, petunidin, and delphinidin. Pomaces from all grape varieties contained pesticide residues. The pomace examined here was comparable in all parameters to pomace described in the literature. After applying the grape pomace to the soil as fertilizer, it is primarily subject to the influence of the weather. The leaching of plant phenols from the pomace into the soil by rain was simulated in a laboratory experiment. The experiment showed that between $6-24\,\%$ of the total phenol content and between $2-17\,\%$ of the condensed tannins were washed out of the pomace into the soil by rain. The relative amount washed out was independent of the pomace used. The relative phenol profile of the leachate is comparable to that of the remaining pomace. The absolute amount of individual compounds washed out depends on the substance and ranges from $<1-40\,\%$. Hexosides of plant phenols in particular were present in reduced concentrations after irrigation. Catechin and epicatechin, as main components of the pomace, were also among the main components in the leachate. Other main components of the profile were dimeric procyanidins and gallic acid. The concentration of plant phenols from grape pomace in soil was first investigated in a laboratory experiment. In addition to fresh grape pomace, ensiled pomace was also considered as a variant of processed grape pomace. In the laboratory experiment, fresh soil from the field was mixed with dried ensiled and untreated grape pomace and examined for phenol content and composition at three time points ($0\,\text{d}$, $17\,\text{d}$, $66\,\text{d}$). The total tannin content was significantly higher in both treatments than in untreated soil only at the first time point after $0\,\text{d}$. The total phenolic content was significantly higher at the first time point $0\,\text{d}$ for both silage and pomace application, and at the second time point after $17\,\text{d}$ only for silage application. The main compounds, catechin and epicatechin, were only detectable in the system at the first measurement point ($0\,\text{d}$). In order to record the degradation of the compounds more accurately, various known degradation products of plant phenols were screened. The concentration of protocatechuic acid in particular was able to accurately reflect the simulated degradation kinetics and was present in significantly increased amounts in the soil after $17\,\text{d}$ in the case of silage. After $66\,\text{d}$, no differences in the phenol profile of the treated and untreated soil were detectable. In order to verify the data obtained in the laboratory with data obtained under real conditions, an additional field trial was conducted on a vineyard. Ensiled grape pomace was applied as organic fertilizer in a vineyard, and the soil was tested for phenolic content and composition at three time points ($19\,\text{d}$ before fertilization, $17\,\text{d}$ and $52\,\text{d}$ after fertilization). As expected from the laboratory test, the total phenol and total tannin content and the content of individual plant phenols remained unchanged over the period under consideration. An exception was protocatechuic acid, which was measurable in significantly higher concentrations after $52\,\text{d}$. During the greening of the aisles $19\,\text{d}$ before fertilization and $52\,\text{d}$ after fertilization, increased amounts of rutin were also measurable compared to the ungreened aisles $17\,\text{d}$ after fertilization. This effect was observed regardless of whether the alley in question was fertilized or not. In summary, it was found that when plant phenols from grape pomace are applied to soil as organic fertilizer, most of them remain in the plant material and are not washed out. There, they are either degraded or adsorbed onto soil particles within a few weeks. To date, it has been difficult to establish a direct link between the introduction of plant phenols into the soil and their effects on soil parameters. One of the biggest challenges is to evaluate the form in which the phenols are present in the soil: adsorbed, free or catabolized. This work presents a way to monitor the complex kinetics of plant phenol degradation kinetics in soil. By measuring the protocatechuic acid content in soil, the degradation of phenols and their direct catabolism products can be tracked and a connection between them and changing soil parameters can be established.

Reifegradbestimmung als Grundlage systemkompatibler Organisationsentwicklung am Beispiel der Sparkassen

Katrin Franziska Neuhäuser — Mon, 08 Jun 2026 09:49:32 +0200

Die vorliegende Arbeit untersucht, wie die Veränderungsreife von Sparkassen systematisch erfasst und für die Gestaltung von Organisationsentwicklungsprozessen nutzbar gemacht werden kann. Ziel ist die Entwicklung eines praxisorientierten Reifegradmodells, das sowohl die organisationale Veränderungsfähigkeit sichtbar macht als auch die Zusammenarbeit zwischen Kunden- und Beratersystem unterstützt. Auf Basis systemtheoretischer Ansätze sowie einer Verknüpfung des Trafo-Modells von HR-Pioneers mit dem Acht-Stufen-Modell nach Kotter wurde ein explorativ-qualitatives Forschungsdesign umgesetzt. Hierzu wurden leitfadengestützte Interviews mit Vertreterinnen und Vertretern von Sparkassen sowie der Organisationsentwicklung der Sparkassenakademie Baden-Württemberg durchgeführt und mittels qualitativer Inhaltsanalyse ausgewertet. Die Ergebnisse zeigen, dass sich Veränderungsreife in unterschiedlichen Mustern organisationaler Wahrnehmung, Kommunikation und Entscheidungsfindung ausdrückt. Daraus wurde ein Reifegradmodell mit den Dimensionen Strategie, Führung, Struktur, Prozesse, HR und Kultur sowie drei idealtypischen Reifegradstufen entwickelt. Das Modell ermöglicht eine differenzierte Standortbestimmung organisationaler Veränderungsfähigkeit und bietet eine Grundlage für die systemkompatible Gestaltung von Veränderungsvorhaben. Gleichzeitig unterstützt es eine wirksame Kopplung zwischen Kunden- und Beratersystem und leistet damit einen Beitrag zur Weiterentwicklung systemischer Organisationsentwicklung im Sparkassenkontext.

Data Fusion in Multi-View Learning for Earth Observation Applications With Missing Views

Francisco Alejandro Mena Toro — Mon, 08 Jun 2026 09:36:07 +0200

Nowadays, more than 9000 satellites orbit and collect data about our planet. These remote observations, regarded as views, have been vital to analyzing and studying complex phenomena on Earth. Thus, the advances in sensor technology and the accessibility of their collected data have increased the research of deep learning models for Earth Observation (EO), such as Multi-View Learning (MVL). However, the integration of this multi-view data, called data fusion, is a challenging process in the EO domain. This is because EO data has a heterogeneous nature with different acquisition modes (e.g. optical and radar), spectral characteristics (e.g. RGB and multi-spectral), and resolutions (e.g. spatio-temporal). This non-standard data goes beyond natural images and benchmark datasets in computer vision, limiting the applicability of modeling approaches and architectures from other domains. Moreover, the lack of systematically available sensor data (i.e. views) covering the same region and period is an inherent problem in the EO domain. This is because data collection occurs under operational constraints in real-world environments, affected by factors like limited spatial coverage, weather conditions, and unexpected errors. These situations beyond our control, as well as human decisions, affect the availability of views at inference time, i.e. when trained models are used to predict new, unseen data. This thesis tackles the challenging problem of missing views at inference time in MVL. In this thesis, two main subjects are addressed. i) MVL modeling, where two research questions are explored: How has data fusion been explored in the EO literature? and What are the best approaches and architectures of MVL?; ii) MVL robustness, which is dragged by the questions: How are MVL models affected by missing data in the EO domain? and How to increase the robustness of MVL models to missing views in the EO domain? In summary, the contributions of this thesis in MVL with EO data are as follows. Provide a conceptual basis of MVL to discuss and compare fusion strategies in the same model framework. Under this framework, an adaptive fusion model is proposed and validated in agricultural applications. This model has the advantage of avoiding saturation of different views used for training. Moreover, the effect of missing views during inference is studied by introducing a configuration to assess robustness, i.e. the decline in performance caused by missing data. Here, the mitigation factors are detached into robustness components and data processing. Finally, four MVL methods are introduced based on the Missing data as Augmentation (MAug) component while employing different fusion strategies and data processing techniques. These models show robustness to different missing views scenarios, including two primary cases: moderate (single-view missing) and extreme (single-view available). In this way, this thesis advances the design of adaptive MVL models capable of handling arbitrary combinations of EO views at inference time.

Jenseits des Sichtbaren – Systemische Perspektiven auf Wahrnehmungsgrenzen und zukunftsoffene Kommunikationen

Ulrich Watermann — Tue, 02 Jun 2026 10:04:44 +0200

Organisationen agieren heute in einer Welt wachsender Komplexität, Unsicherheit und Beschleunigung. Dabei bleiben relevante Entwicklungen in ihrer Umwelt häufig unsichtbar. Diese Arbeit geht der Frage nach, wie es gelingt, jenseits des bisher Sichtbaren zu blicken. Aufbauend auf dem radikalen Konstruktivismus und der Luhmannschen Systemtheorie wird untersucht, wie selbstreferenzielle Organisationen durch ihre operative Geschlossenheit bestimmte Umweltphänomene systematisch ausblenden und welche Konsequenzen dieses Ausblenden für ihre Zukunftsfähigkeit hat. Im Zentrum steht das Konzept des Re-Entry. Es beschreibt die Möglichkeit, Ausgeblendetes wieder kommunizierbar zu machen – ohne die Eigenlogik des Systems zu verletzen. Die Arbeit zeigt, wie systemische Beratung dieses Potenzial nutzbar machen kann; nicht als methodische Intervention, sondern als Ermöglichungsform. Sie öffnet Kommunikationsräume, in denen Zukunft als kontingentes Phänomen denkbar und gestaltbar wird. Organisationen werden so in die Lage versetzt, nicht nur ihre Gegenwart zu verwalten, sondern ihre Zukunft aktiv zu gestalten.

Does the Procedure Matter? Applying a Multiverse Analysis Approach to Negative Emotion Differentiation

Sabrina Ecker; Charlotte Ottenstein; Dominik Vollbracht; Tanja Lischetzke — Wed, 27 May 2026 10:12:43 +0200

Elektronische Strukturen und valenztautomere Prozesse in Chromkomplexen

Kristin Krämer — Wed, 27 May 2026 08:56:53 +0200

Im Rahmen der vorliegenden Arbeit konnte durch die Kombination experimenteller und theoretischer Methoden erstmals gezeigt werden, dass der Makrozyklus N,N'-Dimethyl-2,11-diaza[3.3](2,6)pyridinophan ($L-N_4Me_2$) in Chrom-Komplexen, wie z.B. $[Cr(L-N_4Me_2)(OAc)_2]$, als monoanionischer Diazapyridinophanligand vorliegt. Damit konnte erstmals die Reduktionsfähigkeit des Makrozyklus sowohl strukturell als auch spektroskopisch eindeutig nachgewiesen werden. Ergänzend zu strukturanalytischen Untersuchungen wurden charakteristische spektroskopische Marker identifiziert, die den Nachweis eines reduzierten tetraazamakrozyklischen Liganden in koordinierter Form ermöglichen. Hierzu zählen insbesondere die geschwächte $Cr–N_{py}-$Bindung, eine ausgeprägte intraligand-Elektronenanregung ($L-N_4Me_2$ → $L-N_4Me_2$) sowie die markante antisymmetrische Ringstreckung und -dehnung der Pyridineinheiten am Makrozyklus. Darüber hinaus führte die Einführung fluorierter Acetatoliganden in Form von Trifluoracetatliganden, wie in $[Cr(L-N_4Me_2)(TFA)_2]$, ebenfalls zu einem Chrom(III)-System mit radikalischem ($L-N_4Me_2 ^•)^⁻$-Liganden und einem S = 1 Grundzustand. Temperaturabhängige Untersuchungen zeigen eine reversible Änderung des magnetischen Verhaltens, die auf die thermische Population eines angeregten S = 2 Zustands zurückzuführen ist. Für diesen Quintettspinzustand konnte anhand verlängerter $Cr–N_{amin}-$Bindungsabstände die Besetzung des high-spin Zustandes nachgewiesen werden, der einer ($t_{2g})^3(e_g)^1$)-Elektronenkonfiguration entspricht. Die hier beschriebene Verbindung ist somit das erste Beispiel eines Chromkomplexes, der eine temperaturabhängige Valenztautomerie aufweist.

Interaktion und Kooperation zwischen Immobilien-Projektentwicklern und Kommunen. Akteursbasierte Verhaltensmuster, Spannungslinien und Perspektiven

Ann-Christin Sreball — Tue, 26 May 2026 08:12:25 +0200

Immobilien aller Nutzungsarten prägen das Stadtbild und die Funktionalität von Stadträumen. Mit Blick auf deren Realisierung ist ihr physisch-materielles Konstrukt Ausdruck vorgelagerter Handlungsentscheidungen. Folglich bieten kooperative Handlungen zwischen Kommunen und Projektentwicklern das Potenzial, qualitative Immobilien- und Stadtentwicklungen zu begünstigen. Oft wird dabei unterschätzt, dass Kooperationen kulturelle Grenzüberschreitungen darstellen, die nicht nur die Interessen der jeweiligen Beteiligten berühren, sondern auch deren Identitäten. Die Herstellung eines gemeinsamen Ausschnitts aus den jeweiligen Akteursrealitäten über ein integriertes Problem- und Aufgabenverständnis ist daher eine erforderliche Basis von erfolgsversprechenden Kooperationen. Vor diesem Hintergrund fehlt es jedoch sowohl an Wissen, wie Raumvorstellungen ausgehandelt, vermittelt und legitimiert werden als auch an Wissen, welche Einflussgrößen auf die Interaktion wirken. Die vorliegende Arbeit leistet vor diesem Hintergrund einen Beitrag, diese Forschungslücke zu füllen und das Verständnis über die Ausgestaltung der Interaktion zwischen Kommunen und Projektentwicklern zu erweitern. Kernstück der Arbeit bildet hierzu eine qualitative Inhaltsanalyse, basierend auf 48 leitfadengestützten Experteninterviews mit Vertreter:innen von Stadtplanungsämtern, Ratsmitgliedern, Projektentwicklern, Kapitalgebern sowie Dienstleistungsunternehmen im Planungskontext. Die Untersuchung zeigt, dass institutionell-organisational bedingte Interessenskonflikte zwischen Kommune und Projektentwicklern nicht vollständig auflösbar sind. Darüber hinaus wird der gemeinsame Handlungsrahmen durch externe Einflüsse tendenziell weiter begrenzt. Um sich in diesem „Gerüst“ bewegen und gemeinsame Gestaltungsspielräume schaffen zu können, ist der ernsthafte Wille der handelnden Akteure zur Zusammenarbeit notwendig. Diese vermeintlich offen-sichtliche Voraussetzung für Kooperationen wird in der Planungspraxis jedoch nicht in der Breite gelebt. Inhaltliche Zielkonflikte werden daher durch (latente) Konflikte auf Beziehungsebene verschärft statt entschärft. Die Reflexion von Kooperationsbereitschaft bleibt damit für Wissenschaft und Praxis weiterhin essenziell, wobei aufgrund der Diskrepanz über das Begriffsverständnis von Immobilien – „Lebensumfeld versus Asset“ – und der einhergehenden Verantwortungsübernahme für Immobilien-Projektentwicklungen vielmehr kulturelle Fragestellungen und Wertebewusstsein in den Blick zu nehmen sind als äußere Anreizstrukturen.

Grundstruktur des generischen Angebots- und Nutzungsmodells für die hochschuldidaktische Lehre

Pia Schäfer; Alisha Koch; Susanne Wißhak — Fri, 22 May 2026 14:51:05 +0200

Das generische Angebots- und Nutzungsmodell für die hochschuldidaktische Lehre schlägt eine Möglichkeit zur Strukturierung von Einflussfaktoren auf die Wirksamkeit hochschuldidaktische Lehre vor. Das Modell wurde aus verschiedenen Arbeiten, u.a. zur Wirksamkeit von Lehrkräftefortbildungen (Lipowsky & Rzejak, 2015; Schäfer & van Waveren, 2025) sowie der Trainingsforschung (Alliger et al., 1997; Baldwin & Ford; 1988; Wißhak et al., 2025) abgeleitet. Neben der Strukturierung von Einflussfaktoren werden entlang der Ebenen von Kirkpatrick und Kirkpatrick (2016) auch vier Ebenen zur Evaluation der Wirksamkeit hochschuldidaktischer Lehre dargestellt. Bei diesem Modell handelt es sich um ein Ergebnis aus dem Projekt Transferförderliche Hochschullehre - Ein standortübergreifendes Blended-Learning-Angebot (LehrTransfer).

Vielfalt verlangt Haltung - Systemische Perspektiven auf frühpädagogisches Handeln in superdiversen Kindheiten

Anja Wilhelmi-Rapp — Fri, 22 May 2026 12:59:07 +0200

Die vorliegende Arbeit untersucht, inwiefern systemische Haltungen bei pädagogischen Fachkräften in Kindertageseinrichtungen dazu beitragen können, die Herausforderungen superdiverser Kindheiten zu beantworten. Ausgangspunkt ist die Beobachtung, dass gesellschaftliche Diversifizierungsprozesse zu einer neuen Qualität sozialer Komplexität und daraus resultierenden Herausforderungen an pädagogisches Handeln führen. Eindeutige Zuschreibungen, stabile Kategorien und lineare Lösungsansätze verlieren dadurch zunehmend an Plausibilität. Auf Grundlage des Konzepts der Superdiversität nach Steven Vertovec werden gesellschaftliche Transformationsprozesse und ihre Bedeutung für die Frühpädagogik analysiert. Daran anschließend werden systemisches Denken und Handeln sowie zentrale systemische Haltungen als professioneller Orientierungsrahmen herausgearbeitet. Die Arbeit zeigt, dass systemische Haltungen einen professionellen Umgang mit sozialer Komplexität ermöglichen, weil sie die Sensibilität für Kontextabhängigkeit, Wechselwirkungen, Mehrdeutigkeit und die eigene Beobachterposition fördern.

Five Essays on Overlapping-Generations Models

Paul Maximilian Ritschel — Fri, 22 May 2026 11:44:55 +0200

This cumulative dissertation in theoretical macroeconomics presents five articles on deterministic, analytically tractable overlapping-generations models with two-period-lived agents and production. The microeconomic foundations are rooted in contract and game theory, while the analysis of macroeconomic dynamics builds on dynamical systems theory. Article 1 establishes that financial intermediation which provides efficient risk sharing cannot generate endogenous fluctuations. Article 2 examines how competition in the banking sector affects economic growth and welfare in the real sector. Article 3 investigates the impact of market power and strategic interaction in the capital market on savings, capital accumulation, and the qualitative dynamics. Article 4 introduces a novel parameterization of the production-possibility frontier in terms of wage-rental ratios that can enhance both the generality and tractability of two-sector growth models and allows for a refinement of the Rybczynski theorem. Building on this parameterization, Article 5 develops a tractable two-sector model with intergenerational pollution externalities to study the role of fiscal policy in steering the green transformation of an economy. The findings of this dissertation contribute to a deeper understanding of the determinants of economic growth, the sources of real business cycles, and normative welfare implications, while also providing recommendations for policymakers.

Nominal Compounds, Information, and Scientific Texts

John Cristian Borges Gamboa — Tue, 19 May 2026 15:45:19 +0200

Scientific texts are commonly known to be hard to read. This may be for a number of reasons, such as the fact that they contain a large number of nominalizations, they often use complicated jargon, and sometimes even assume reader knowledge. In order to find ways to make scientific texts clearer, it may be worth to better understand the characteristics of this register. In this thesis, I focus on one aspect of scientific texts: their frequent use of a structure I refer to as complex nominal compounds. Nominal compounds (structures such as "research paper", "linguistic analysis paper") are composed of a head noun ("paper") and one or more modifiers ("research", "linguistic", "analysis"), which can be either nouns or adjectives. Complex nominal compounds are nominal compounds made up of three or more words. Despite decades of research on nominal compounds (complex and otherwise), little is known about how complex nominal compounds are processed, or about how they are used in scientific papers. In this thesis, I take steps towards filling this gap. In my attempt to do so, I recruit two frameworks of language processing and use, through which I produce predictions for the experiments I report here: the Entropy Rate Constancy (ERC) Principle and the Uniform Information Density (UID) Hypothesis. Of particular relevance, not much attention has been given to the UID Hypothesis from the point of view of comprehension. These experiments, therefore, not only contribute towards the understanding of nominal compounds, but also test the validity of these frameworks in general, and of the UID Hypothesis from the perspective of comprehension in particular. On the processing front, the thesis analyzes the L1 and L2 processing of complex nominal compounds, comparing them with a different structure that was predicted to be easier to process: nouns followed by prepositional phrases (e.g., "paper on the analysis of language"). The results do show that compounds are harder to process than the alternative structure, but were not as clear as predicted. On the usage front, the thesis analyzes the distribution of compounds in a corpus of 182 scientific papers of Biology, Linguistics and Economics. Compounds appear with roughly the same frequency throughout the different regions of the papers (i.e., do not cluster in specific areas), and are not reused much after the first use. They are also typically set up by their context, and this does have an impact on the difficulty experienced by readers when encountering them (at least when encountering unfamiliar compounds). The results corroborate the recommendations from writing guides suggesting that compounds should be used with parsimony, but also suggests that familiar compounds do not need to be avoided as much, as that providing contextual support may mitigate some of the difficulties experiencied by readers when encountering these structures. It is my hope that future writing guides will take these findings into consideration. In addition, the results partially support the ERC Principle and the UID Hypothesis, but were not as clear as predicted, and raise questions about the validity of the ERC Principle in texts and of the UID Hypothesis for comprehension.

Amtliche Bekanntmachung der RPTU Kaiserslautern-Landau 2026.05

Tue, 19 May 2026 12:21:13 +0200

Amtliche Bekanntmachung der RPTU Nr.5/20.05.2026

Performance Evaluation of Vehicular-to-Everything (V2X) Technologies and Machine Learning (ML) based PHY assistance

Raja Sattiraju — Tue, 19 May 2026 11:55:50 +0200

The first four generations of mobile cellular networks were primarily utilized for personal communications and focused solely on increasing system capacity and user data rates. The fifth generation (5G) mobile communications standard revolutionized the cellular connectivity by adding support for new use cases such as Enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC) and massive Machine Type Communications (mMTC). This enabled the foray of cellular communication technologies into new verticals such as Vehicular-to-Everything (V2X) communication, Internet of Things (IoT), industrial communications etc. V2X allows vehicles to directly communicate with each other, roadside infrastructure, and other road users to deliver an array of services. It forms a compelling usecase for 5G due to its potential to provide benefits such as road safety, traffic efficiency, smart mobility, environmental sustainability, and driver convenience. Currently, two Radio Access Technologies (RATs) exist for V2X communication: Intelligent Transportation Systems (ITS)-G5, based on the IEEE 802.11 standard that has been well over 20 years in research and development, and Cellular Vehicle-to-Everything (C-V2X), based on the newer but more established and global 3rd Generation Partnership Project (3GPP) standard. Both technologies have their own pros and cons, with ITS-G5 offering ease of deployment due to its lightweight protocol and complete decentralized operation, whereas C-V2X offers better radio performance, tighter integration with cellular networks etc. Before deploying any RAT, it is important to extensively evaluate it by means of analytical, empirical and Monte-Carlo methods. This forms the core of the first part of this thesis, where a detailed link and system level performance comparison has been carried out for ITS-G5 and C-V2X. A new link-level simulation framework, namely pycv2x, has been developed from scratch for evaluating C-V2X, whereas for ITS-G5 the open-source implementation from ublox was used. An extensive library of digital signal processing blocks for coding, modulation, channel estimation & equalization, and frequency and timing offset correction was developed for C-V2X. The developed simulation framework is tested with the 3GPP reference channel models, and the simulation results match the expected values from the 3GPP Rel.14 specification. Once the link-level simulations are ready for both C-V2X and ITS-G5, the next step is to run Monte-Carlo simulations for a wide variety of channel models. The simulations considered varying channel models, ranging from simple Additive White Gaussian Noise (AWGN) models to multi-path fading models with varying delay profiles. After an extensive literature survey, a total of 8 different channel models (from the International Telecommunication Union (ITU) and Dedicated Short Range Communications (DSRC)) specifically designed for vehicular scenarios were selected and the simulations were carried out. The results show that, in a single transmission scheme, C-V2X outperforms ITS-G5 in almost all of the considered channel models, with some exceptions for 16-Quadrature Amplitude Modulation (QAM) and higher coding schemes. With one blind retransmission enabled, C-V2X exhibits a gain of at least 6 dB and in some cases reaches as high as 10 dB over ITS-G5. Link-level simulations capture the Physical Layer (PHY) performance with a single link only. In order to understand the system capacity, a system level analysis is necessary that considers the upper Media Access Control (MAC) layer schemes. The thresholds for calculating packet errors at the system level are derived from the link level simulation by means of link-system level mapping curves (SNR - BLER curves). In this regard, a realistic system level simulation framework using real-world maps and traffic was developed to evaluate the MAC schemes of ITS-G5 and C-V2X — namely Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and Semi-Persistent Subchannel Selection (SPSS) respectively. The simulation approach is based on bidirectionally coupling the vehicular traffic simulator (Simulation of Urban Mobility (SUMO)) and the network simulator. The analysis was carried out for European Telecommunications Standards Institute (ETSI) defined scenarios such as highway and Manhattan grid. As an additional novelty, complex scenarios using real-world maps and traffic for the cities of Kaiserslautern and Merzig were also considered for simulation, capturing the traffic characteristics of both urban and rural areas. Overall, it can be seen that C-V2X has a higher range than ITS-G5 in line with the specification. This is reflected in the Packet Error Rate (PER), where ITS-G5 maxes out before C-V2X. In terms of distance, this translates to a range gain of almost 100 m for Quadrature Phase Shift Keying (QPSK) coding schemes and almost 200 m for 16-QAM schemes. C-V2X also makes more efficient use of the spectrum compared to ITS-G5, which can be seen in the form of higher Channel Busy Ratio (CBR). The retransmission gain with C-V2X is significant at higher Modulation & Coding Scheme (MCS) schemes, lower vehicular densities and higher speeds. Machine Learning (ML) / Artificial Intelligence (AI) is a topic that has generated huge interest in both academia and industry, due to the availability of data and the processing power necessary to analyze it. Consequently, it is being widely evaluated and used in almost every engineering domain. The wireless community has also started to embrace ML over the last 5 years, and many works have been carried out to assess its applicability across the entire protocol stack. This forms the core of the second part of this thesis, where different ML strategies were evaluated for signal processing operations such as channel coding, channel estimation, reliability prediction, and obstacle detection. Autoencoders are one of the first applications of ML conceived at the PHY layer, where a well-trained ML model can mimic the behavior of any signal processing block (eventually the entire PHY pipeline). The idea is that if we design a moderately complex ML model and train it with the input and output samples of any given signal processing block (such as coding/modulation), the autoencoder can learn the inherent patterns in the data and, after enough iterations, will start generating the same outputs as the considered signal processing block. In this regard, two ML models were developed for turbo decoding and channel estimation. The first is based on a Recurrent Neural Network (RNN) architecture, which is well suited to understanding time-series patterns and can therefore decode the inherent sequence dependency of turbo codes. The second is based on a Convolutional Neural Network (CNN) architecture, which is good at understanding spatial dependencies and is therefore a better candidate for channel estimation, which involves averaging operations across frequency subcarriers. The models were trained and compared with legacy signal processing blocks, and the results show that the ML-based models perform on par with or sometimes even outperform their legacy counterparts. CNN-based channel estimation in particular is seen to improve the system performance, especially in high-speed scenarios where there is a high Doppler. Proactive link adaptation and management is another key area in wireless communication where ML-based solutions can bring a significant performance gain and add value to the overall RF chain. In this regard, a novel reliability prediction scheme based on Long Short-Term Memory (LSTM) networks is proposed, which predicts the Signal to Interference plus Noise Ratio (SINR) for subsequent transmissions based on previous values obtained after channel equalization. This knowledge can help the transmitter adjust the MCS scheme before a Channel Quality Indicator (CQI) feedback from the receiver arrives. By combining the received CQI with the predicted value, the model can be tuned dynamically to make accurate predictions and subsequently optimize link adaptation. Another novel method for detecting the presence/absence of obstacles with ML algorithms on raw Ultra-Wide Band (UWB) waveforms is also investigated in this thesis. Raw UWB waveforms were collected in indoor/outdoor scenarios and labeled appropriately: 1 denotes the presence of an obstacle (human) and 0 denotes no obstacle. A suite of supervised ML models was trained on the training dataset and used to predict on the test set. The results show that just by using raw waveforms (without any need for further filtering), supervised ML-based methods can detect obstacles with accuracies close to 95%.

Inner Development Goals als Rahmen für die Professionalisierung von Schulleitungen: Ein konzeptioneller Ansatz

Frederike Weiler — Tue, 19 May 2026 11:53:12 +0200

Die Anforderungen an Schulleitungen haben sich unter Bedingungen von Volatilität, Unsicherheit, Komplexität und Ambiguität (VUKA) deutlich verändert. Neben administrativen Aufgaben gewinnen insbesondere personale, relationale und reflexive Kompetenzen an Bedeutung. Bestehende Professionalisierungsformate berücksichtigen diese inneren Entwicklungsdimensionen bislang jedoch nur begrenzt. Die vorliegende Masterarbeit untersucht daher, inwiefern die Inner Development Goals (IDGs) als theoretischer Orientierungsrahmen zur Ergänzung bestehender Professionalisierungsformate für Schulleitungen dienen können. Grundlage ist eine theoretisch-konzeptionelle Analyse aktueller Führungsmodelle, Professionalisierungsanforderungen und der fünf IDG-Dimensionen Being, Thinking, Relating, Collaborating und Acting. Die Ergebnisse zeigen, dass die IDGs insbesondere in den Bereichen Selbstführung, Reflexionsfähigkeit, Kooperation und Umgang mit Komplexität eine hohe Anschlussfähigkeit an die Anforderungen modernen Schulleitungshandelns besitzen. Daraus wird ein heuristischer Orientierungsrahmen für die reflexive Professionalisierung von Schulleitungen abgeleitet. Die Arbeit leistet damit einen konzeptionellen Beitrag zur Weiterentwicklung professioneller Qualifizierungsangebote im Schulmanagement.

Fluid Phenomena on Lithium Niobate, an Intrinsically Charged Surface

Sushmitha Vinikumar — Mon, 18 May 2026 07:52:25 +0200

Interfaces play a crucial role in various physical and chemical phenomena, such as catalysis, molecular recognition, charge transfer, adsorption, and diffusion. While the role of external electric fields in controlling interfacial behavior, such as flow control and droplet manipulation has been well explored, the influence of surface charge on these processes is less understood. Surface charge can arise naturally, as in ferroelectric materials, or be artificially induced through the triboelectric effect in polymers. This research aims to bridge the gap in understanding how surface charge affects key interfacial processes like wetting, spreading, and evaporation. The present study investigates the dynamic interactions at the interface between fluids and charged surfaces, focusing on the interaction between water and lithium niobate (LN), an intrinsically charged ferroelectric material. LN, a ferroelectric material with an exceptionally high surface charge density (theoretically 0.7 C/$\mathrm{m^2}$), was chosen as the primary material for this study. The study begins by investigating classical interface phenomena, including electroosmosis, specifically on a $z$-cut LN surface. Electroosmotic flow in LN-based microchannels is compared with that in glass channels, highlighting the role of spontaneous polarization and surface charge in modulating flow velocity. The study then examines the wetting dynamics of a water droplet on a $z$-cut LN surface, focusing on how polarization direction and surface charge influence its spreading behavior. Additionally, it explores the effects of adsorption and ferroelectric aging on wetting characteristics. The study also investigates the evaporation behavior of water droplets on $z$-cut LN surfaces, examining how factors such as relative humidity and surface polarization direction influence evaporation rates. The evaporation rate on the $z$-cut LN surface is then compared to that of other materials with similar contact angles to assess the unique role of surface charge in evaporation. The final part of the investigation focuses on the fabrication of hydrophobic, photocatalytically active antibacterial surfaces using PDMS and LN. The hydrophobic surface aims to minimize bacterial adhesion, while the photocatalytic activity targets bacterial disinfection. Different fabrication parameters, such as LN concentration, illumination conditions, and surface roughness, are optimized to enhance antibacterial performance. The antibacterial properties of these surfaces were tested using two bacterial strains: \textit{Escherichia coli} DH5$\alpha$ and \textit{Pseudomonas aeruginosa} PA14. This study investigated the often-overlooked impact of surface charge on interfacial processes such as wetting and evaporation. The findings of the study reveal that, despite LN's significantly large surface charge, it does not translate into an exceptionally high zeta potential due to charge neutralization in the Stern layer and a minimal diffuse layer, which limits its potential for electroosmotic flow. The droplet spreading dynamics of LN deviate from classical Tanner's law, with an exponential spreading phase dominating. In addition, the presence of an adsorbed layer substantially reduces the contact angle, accelerating the spreading process. These findings emphasize the importance of cleaning procedures and storage conditions for wetting studies and suggest broader relevance for understanding charge-driven spreading processes, such as electrowetting. The evaporation process on LN involves three stages: constant contact radius, mixed, and stick-slip phases. The stick-slip behavior on the smooth LN surface, even with pure water, indicates strong pinning caused by surface charge and high water affinity. The droplet evaporation studies show that polarization direction significantly affects the initial contact angle, evaporation rate, and total evaporation time, while relative humidity impacts the wettability of the +$z$-cut surface but not the -$z$-cut surface. Antibacterial studies demonstrate that LN-based surfaces can be used as light-stimuli-sensitive, requiring UV illumination for activation, making them effective for reducing bacterial transmission on frequently touched surfaces. Furthermore, the potential for LN's polarization-specific surface chemistry and wettability alterations could be leveraged in fabricating nanoscale devices, sensors, and biocompatible materials for tissue engineering. LN-based materials also hold promise for applications in energy harvesting from droplet motion and stimuli-responsive antibacterial therapeutics, with further research needed to optimize these effects.

Silikabasierte Katalysatoren zur Hydrierung von Olefinen

Sebastian Werner Simon — Fri, 15 May 2026 11:41:05 +0200

Diese Dissertation beschäftigt sich mit der Darstellung, Charakterisierung und Anwendung silikabasierter Hydrierkatalysatoren. Zunächst konnten neuartige Palladium(II)- und Rhodium(I)phosphankomplexe über eine imidazolinium-funktionalisierte Linkergruppe auf SBA 15, Kieselgel sowie einem Janus-Material immobilisiert werden. Die erhaltenen Single-Site-Materialien wurden anschließend mit Wasserstoff reduziert. Nach der Charakterisierung der Katalysatorproben vor und nach der Wasserstoffbehandlung wurde ihre katalytische Aktivität verglichen. Bei der Hydrierung von 2-Cyclohexen-1-on (XIV) zeigte sich dabei eine signifikante Aktivitätssteigerung bei den reduzierten Proben. Weitere neun Olefine konnten in guten Ausbeuten und hoher Selektivität unter Einsatz der reduzierten Katalysatorproben hydriert werden (Reaktionsbedingungen: 100 °C, 15 bar Wasserstoff, 1 mmol Substrat, LM (1 mL), 0.2 mol-% Pd / Rh, 2 h). Aufgrund der vielversprechenden Aktivitäten der mit dem Janus-Material geträgerten Katalysatoren wurde anschließend die Hochskalierung der Synthese dieses Trägers untersucht. Dabei wurde der Einfluss der Anreicherung der Edukte bei konstanten Mengen an Wasser und Ethanol auf die Partikelmorphologie mittels REM-Analysen verfolgt. Ab einem sechsfachen Skalierungsgrad bildeten sich keine Silikahohlpartikel mehr aus. Geringere Ammoniakmengen führten zudem zu löchrigen Partikelwänden. Abschließend wurden neuartige Palladium(II)- und Rhodium(I)phosphankomplexe einer zweiten Generation synthetisiert, welche über eine schwefelhaltige Linkergruppe auf SBA 15 und Kieselgel kondensiert wurden. Analog zu den zuvor beschriebenen Materialien wurden unter einer Wasserstoffatmosphäre die reduzierten Katalysatorproben synthetisiert. Entsprechend war auch bei diesen Materialien eine gesteigerte katalytische Aktivität der reduzierten Proben bei der Hydrierung von 2-Cyclohexen-1-on (XIV) festzustellen. Mittels eingehender struktureller Untersuchung, unter anderem mittels XPS- und TEM-Analysen, konnte dieser Befund maßgeblich auf die Bildung nullvalenter Metallspezies zurückgeführt werden. Unter optimierten Bedingungen konnten schließlich weitere neun Olefine mit guten Ausbeuten unter signifikant milderen Bedingungen hydriert werden (Reaktionsbedingungen: RT, 1 bar Wasserstoff, 1 mmol Substrat, Cyclohexan (2 mL), 0.2 mol-% Pd / Rh, 5 h).

A 4.266 Gbps/pin LPDDR4X PHY with an Integrated RISC-V Subsystem Optimized for Large Bump Pitch in 12nm FinFET Technology

Wed, 13 May 2026 13:31:07 +0200

Low Power Double Data Rate 4X (LPDDR4X) is a leading memory standard for mobile applications, delivering data rates up to 4266 Mbps with minimal power consumption. However, its low 0.6V I/O supply voltage and tight timing requirements pose significant challenges to signal integrity and synchronization. This paper presents a full LPDDR4X physical interface (PHY) in GlobalFoundries 12 nm FinFET technology that addresses these issues through novel output driver calibration, digitally controlled delay lines, and de-skewing clock generators. We further incorporate On-Die Termination calibration with comparator offset compensation to ensure robust I/O performance. By integrating a RISC-V subsystem, our PHY enables low-level software control of the memory interface and a fully programmable calibration and training algorithm. The measured results from the fabricated prototype confirm the effectiveness of the proposed strategies, achieving write margins of 300mV/0.61UI at 1.6Gbps and 200mV/0.38UI at 2.133Gbps. Post-layout simulations in all Process-Voltage- Temperature corners at 4.266Gbps show instead write margins of 80mV/0.57UI and 140mV/0.72UI in worst and best corners respectively. The measured output clock amplitude at 2.133GHz is 160mV differential. These findings underscore the feasibility of a LPDDR4X PHY solution that meets stringent performance and power requirements in advanced technology nodes.

A 15 Gb/s Single-Ended Active-Inductive Equalizer with an Optimized Gain-Enhancing Technique

Wed, 13 May 2026 13:25:11 +0200

In this paper, a 15 Gb/s single-ended active inductive linear equalizer with an improved gain-enhancing method is presented. The proposed architecture consists of an activeinductive single-stage continuous-time linear equalizer (CTLE) to compensate for the high-frequency channel loss followed by a common-source stage with resistive load to generate a noninverting output as well as enhance the signal swing and sampling margin. Furthermore, an optimized gain-enhancing technique is introduced in the CTLE stage which noticeably improves the low-frequency gain and the output signal swing. In order to evaluate the performance of the proposed gain-enhanced CTLE, two common active-inductive CTLE approaches were designed and simulated in 12nm FinFET technology to compare with the proposed architecture. The simulation results show that the proposed gain-enhancing technique improves the output signal swing of the CTLE by 30% compared to the state-of-the-art with no power and area overhead. The proposed equalizer draws 1.74 mW at a Nyquist frequency of 7.5 GHz and a supply voltage of 0.8 V. In addition, it compensates for a channel attenuation of 22 dB with a figure-of-merit (FoM) of 5.27 fJ/bit/dB, indicating a considerable improvement over previous studies.

Design of a Low-Power 4.3 Gb/s Transceiver Using Pre-computed Lookup Tables

Hussien Abdo; Jan Lappas; Mohammadreza Esmaeilpour; Christian Weis; Norbert Wehn — Wed, 13 May 2026 09:02:04 +0200

High-speed memory interfaces require the design of optimised low-power and robust analog circuits. This poses significant challenges in sizing due to the inability of using complex modern transistor models, such as the Berkeley Shortchannel IGFET Model (BSIM), to calculate the sizing of the circuits based on hand-analysis. This forces designers to perform iterative simulations, which is time-intensive and error-prone. To address these issues, this work presents an automated sizing approach using pre-computed lookup tables (LUTs) for a 4.3 Gb/s LPDDR4X transceiver in 12nm FinFET technology. The receiver is designed based on gm/ID sizing methodology where look-up tables are used to compute a set of matrices representing the possible design points based on the circuit topology. The design space is constrained by the biasing level, gain, and bandwidth to find an optimised design point in terms of operation region, speed and power. The driver circuit design is automated based on a new algorithm which computes the estimated ON-resistance from the look up table and finds an optimum sizing which fulfills the required impedance range. The calculated sizing of the proposed design approach was used as an input for spectre simulator to compare the simulation results with the input specifications, showing an error margin of less than 1%. Furthermore, the receiver power consumption was evaluated to be 70% less than the work in literature. The proposed driver topology, which uses low voltage swing terminated logic (LVSTL) and near-ground signaling (NGS), provides a 38−120 Ω impedance range at all process, voltage and temperature variations (PVT) for the postlayout results and consumes relatively low power when compared to literature.

Dreidimensionale Panelmethode für das aerodynamische Design von Winglets bei Vertikalachsen-Windkraftanlagen

Yannick Martini — Wed, 13 May 2026 08:42:55 +0200

Vertikalachsen-Windkraftanlagen gelten als vielversprechende Alternative zu den etablierten Windkraftanlagen mit horizontaler Achse, insbesondere im urbanen Raum und unter stark turbulenten Strömungsbedingungen. Trotz ihrer konstruktiven Vorteile in solchen Einsatzgebieten weisen sie im Vergleich zu Horizontalachsen-Windkraftanlagen eine geringere aerodynamische Effizienz auf. Die gezielte Leistungssteigerung durch strömungsgünstige Rotoranpassungen stellt daher einen zentralen Forschungsschwerpunkt dar. Ihre systematische Umsetzung erfordert jedoch geeignete numerische Entwurfswerkzeuge, mit denen sich die zugrunde liegenden komplexen Strömungsvorgänge effizient analysieren und bewerten lassen. Mit dem Designtool OpenWIEN wird im Rahmen dieser Arbeit eine dreidimensionale Panelmethode entwickelt, die instationäre Strömungsvorgänge an Vertikalachsen-Windkraftanlagen einschließlich einer expliziten Nachlaufstruktur aerodynamisch konsistent abbildet. Um die Aussagekraft der implementierten Methode einzuordnen, erfolgt ein Vergleich mit Ergebnissen zweidimensionaler CFD-Simulationen, anhand derer die Übereinstimmung zwischen beiden Ansätzen im optimalen Betriebsbereich der Anlage bewertet wird. Grundlage des Vergleichs bildet dabei eine dreiblättrige Konfiguration mit NACA-0021-Profil. Darauf aufbauend wird die Panelmethode im Rahmen einer Variantenstudie auf 27 verschiedene Winglet-Konfigurationen angewendet, um ihr Potenzial als effizientes Werkzeug im konzeptuellen aerodynamischen Entwurfsprozess zu evaluieren. Ziel ist es hierbei, leistungssteigernde Konfigurationen zuverlässig zu identifizieren und den Einsatz rechenintensiver, insbesondere dreidimensionaler CFD-Simulationen auf vielversprechende Designvarianten zu beschränken. Hierfür wird neben der aerodynamischen Effizienz auch die strukturelle Belastung in Form des auf die Rotorblätter induzierten Biegemoments in die Bewertung einbezogen. Die Ergebnisse des Vergleichs zwischen OpenWIEN und CFD zeigen im optimalen Betriebsbereich der Windkraftanlage eine weitgehende Übereinstimmung und bestätigen die Konsistenz beider Ansätze. Die anschließende Variantenanalyse belegt zudem, dass sich OpenWIEN für den konzeptuellen Entwurfsprozess eignet und bereits in frühen Entwicklungsphasen belastbare Aussagen zur aerodynamischen Performance verschiedener Winglet-Geometrien zulässt.

Saving the midnight oil?

Sebastian Felix Neubert — Mon, 11 May 2026 18:35:09 +0200

Working time reductions (WTRs) have been proposed as a policy with potential benefits for both the environment and well-being. Yet, empirical evidence remains limited. Moreover, the mechanisms through which WTRs affect well-being and environmental outcomes are not well understood. Income and time exert distinct influence, while moderating factors such as gender further shape these outcomes. To address these research gaps, my co-authors and I systematically reviewed 30 longitudinal and (quasi-)experimental studies examining the effects of different conceptualisations of WTRs (Manuscript 1). Second, I conducted a quasi-experimental study comparing Swiss employees who reduced their working hours with those who did not (Manuscript 2). Third, I cross-sectionally analysed the same data, focussing on gendered effects on time use and well-being (Manuscript 3). Our findings show that WTRs improve well-being, health, and work-family conflict, but that evidence on environmental effects is less convincing. In the longitudinal study, I found that while lower working hours enhance well-being, lower income negatively affects it, resulting in only short-term improvements in subjective well-being for those reducing their hours. For environmental behaviour, a WTR had small positive impacts for some, but no changes for other environmental behaviours. Furthermore, our research indicates that women may benefit more from WTRs than men regarding work-family conflict, suggesting gender dynamics play a crucial role. This research advances our understanding by synthesising empirical evidence of WTRs across multiple domains with more robust and causally interpretable methods. Importantly, I could replicate that environmental outcomes appear to primarily depend on income effects, whereas framing well-being outcomes in terms of income and time effects alone may be insufficient for understanding the complex dynamics of different factors at play – such as gender, work-family conflict, and time use. Crucially, the counteracting influences of income and working hours on well-being have implications for the income–well-being debate: Working less might provide a more sustainable route to increase well-being than earning more. Finally, my research highlights a possible conflict: Environmental effects of WTRs may require decreasing income, whereas social benefits may require a full wage compensation.