KLUEDO Dokumente/documents https://kluedo.ub.rptu.de/index/index/ Wed, 13 May 2026 13:31:07 +0200 Wed, 13 May 2026 13:31:07 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13119 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. Marco Mestice; Johannes Feldmann; Jan Lappas; Mohammadreza Esmaeilpour; Christian Weis; Norbert Wehn conferenceobject https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13119 Wed, 13 May 2026 13:31:07 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13118 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. Mohammadreza Esmaeilpour; Marco Mestice; Jan Lappas; Christian Weis; Norbert Wehn conferenceobject https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13118 Wed, 13 May 2026 13:25:11 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13113 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. Hussien Abdo; Jan Lappas; Mohammadreza Esmaeilpour; Christian Weis; Norbert Wehn conferenceobject https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13113 Wed, 13 May 2026 09:02:04 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13116 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. Yannick Martini doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13116 Wed, 13 May 2026 08:42:55 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13099 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. Sebastian Felix Neubert doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13099 Mon, 11 May 2026 18:35:09 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13109 Language is a dynamic and adaptive system, continuously shaped and thus continuously changing based on language users’ interactions, social environments, and cognitive mechanisms. Language contact (i.e., the co-existence and interaction of two or more linguistic systems within individuals or communities) has been recognized historically as a primary source of change. Particularly in bilingual language contact, speakers are systematically exposed to two distinct grammatical systems, constantly shifting between languages and often transferring properties from one language into another. Such transfer can lead among others to the emergence of non-canonical/ungrammatical syntactic structures, hereafter referred to as structural innovations. Structural innovations are particularly crucial to explore in the framework of contact-induced change, as they provide insights into the conditions and constraints of language change processes. However, to better understand how language change occurs and develops in contact situations, we need to investigate the psycholinguistic mechanisms underlying them. On this basis, the present dissertation investigates how bilingual speakers cognitively adapt to structural innovations in their input and how this might lead to potential longer-term language change in a community/society. All studies of this dissertation tested Canadian French-English bilinguals, a population situated in an officially bilingual, yet extremely diverse, environment where language contact has been a persistent historical reality. Each study focuses on a different stage or manifestation of adaptation –whether through changes in speakers’ perception (acceptability judgments), online processing, or production– and together they provide a multidimensional picture of how structural innovations might enter and/or stabilize in bilingual grammars, setting the ground for language change. Foteini Maria Karkaletsou doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13109 Mon, 11 May 2026 13:57:20 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13103 We study integration and \(L^2\)-approximation of functions in infinite or finite tensor products of Hilbert spaces; our main interest lies in the infinite-variate case. As univariate building blocks of the tensor product, for \(j\in\mathbb{N}\) we consider Hilbert spaces \(H(k_j)\) with reproducing kernels \(k_j\), whose elements are functions on a domain \(D\subseteq\mathbb{R}\). Additionally we assume that the \(H(k_j)\) are spaces of square-integrable functions with respect to a probability measure \(\mu_0\). Commonly studied examples are \(D=[0,1]\) with the uniform distribution \(\mu_0\), as well as \(D=\mathbb{R}\) with the standard normal distribution \(\mu_0\). For \(d\in\mathbb{N}\) or \(d=\infty\), we study integration or \(L^2\)-approximation on the space \(H(\bigotimes_{j=1}^dk_j)\) with respect to the product measure \(\bigotimes_{j=1}^d\mu_0\). To ensure that problems can be solved with reasonable costs and errors in the infinite-variate and the high dimensional case, intuitively speaking, the univariate problems on \(H(k_j)\) have to become easier sufficiently fast as \(j\) increases. We represent this mathematically with the help of suitable smoothness parameters. We study the important special case that the kernels \(k_j\) are given by \[k_j(x,y) = \sum_{\nu\in\mathbb{N}} {\alpha_{\nu,j}^{-1}h_\nu(x)h_\nu(y)},\] where \((h_\nu)_{\nu\in\mathbb{N}}\) is an orthonormal basis in \(L^2(\mu_0)\) and \((\alpha_{\nu,j})_{\nu,j\in\mathbb{N}}\) is a family of positive real Fourier weights. In this case, the growth of the Fourier weights in \(j\) quantifies how fast the univariate problems become easier. As an important example, we study the Hermite polynomials \(h_\nu\) with the standard normal distribution \(\mu_0\) on \(\mathbb{R}\), which leads to Hermite spaces. We determine the polynomial decay of the \(n\)-th minimal errors of the infinite-variate problem in terms of the Fourier weights. The second important special case we study are spaces \(H(k_j)\) whose kernels are given as Gaussian radial basis functions (Gaussian kernels), while our problems are again based on the standard normal distribution \(\mu_0\). We establish the following transference result between spaces with Gaussian kernels and Hermite spaces: The is a one-to-one-correspondence between spaces with Gaussian kernels and Hermite spaces with exponential growth of the Fourier weights such that the integration problem is equivalent on corresponding spaces. An analogue result holds true for the \(L^2\)-approximation problem. Utilizing this equivalence, we are able to constructively transfer upper and lower error bounds from one type of space to the other. In particular we construct almost optimal algorithms for spaces with Gaussian kernels in the infinite-variate case. Additionally, we are able to improve some known results in the finite-variate case. Robin Rüßmann doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13103 Fri, 08 May 2026 08:26:19 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13100 Informationen aus dem Lehrstuhl für Fertigungstechnik und Betriebsorganisation periodicalpart https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13100 Thu, 07 May 2026 11:38:41 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13093 Die vorliegende Arbeit untersucht die Digitalisierung des Theaterbetriebs in Deutschland als vielschichtigen Transformationsprozess, der künstlerische, organisatorische, wirtschaftliche und kommunikative Dimensionen gleichermaßen betrifft. Ausgangspunkt ist die heterogene Struktur der deutschen Theaterlandschaft, die durch ein Nebeneinander öffentlich finanzierter und privatwirtschaftlich organisierter Häuser geprägt ist und unterschiedliche Voraussetzungen für digitale Entwicklungen schafft. Im Zentrum der Analyse stehen die vielfältigen Einsatzmöglichkeiten digitaler Technologien entlang zentraler Managementbereiche. Christian Rainer Gebhardt-Eich masterthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13093 Tue, 05 May 2026 08:25:04 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13094 Mona Dian doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13094 Mon, 04 May 2026 17:35:22 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13091 This thesis shows the capability of time-resolved spectroscopic methods in investigating the photophysical and photochemical processes involved in a plethora of applications. It also highlights the necessity of combining orthogonal spectroscopic techniques to get a complete understanding of the excited states involved. I performed step-scan FTIR spectroscopy, luminescence spectroscopy and time-correlated single photon counting on multiple series of mono- and oligometallic complexes and thereby identified trends, which can be used in further optimization of the photophysical behaviour of the investigated metalorganic compounds and similar complexes by modifications. The interpretation of the spectra with (TD)-DFT methods helped in distinguishing between similar species as for example with determining the structure of ligands and determining oxidation and spin states of both ground and excited states of not only the original complex, but also intermediate species and photoproducts. The influence of substitution patterns of ligands was investigated and a clear trend between electron donating and electron withdrawing substituents was found by step-scan spectroscopy, while it remained unclear in the photoluminescence measurements alone due to the strong effect of the sample matrix. The replacement of bystander ligands proved to assert severe effects on the lifetimes and TADF capabilities in a series of complexes, strongly suggesting a large involvement of the spin-orbit coupling in the excited states with ligands with elements with higher ordinal numbers. Cooperative effects by metallophilic interactions proved to play a vital role with some metal combinations forming strong intermetallic interactions in the ground and excited states, some in neither state and one other only in the excited state, leading to a structural deformation of the ligand backbone in the excited state geometry. The influence of constitutional isomers was investigated and showed to have stronger effects than originally expected not only increasing lifetimes of excited states, but also transforming dark states into luminescent ones. Finally, the influence of oxidation and spin states on vibrational spectra, especially on the stretching vibrations of hydrogen bonding was utilized to clarify the ground state structures of a series of trimetallic complexes while measurements previous to the investigations seemed to contradict each other. A variety of seemingly minor changes in metalorganic complexes was characterized leading to meaningful insights of how to improve certain properties selectively. Daniel Marhöfer doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13091 Thu, 30 Apr 2026 14:01:14 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13090 The synthesis of logical controllers that guarantee desired specifications is a central problem in the design of cyber-physical systems (CPS). In practice, such guarantees rely on assumptions about how the controller interacts with its environment. These assumptions restrict environment behavior to make synthesis feasible, but in existing approaches they are often overly restrictive, leading to conservative designs and limiting the range of behaviors that systems can safely accommodate. This thesis rethinks the role of assumptions in logical controller synthesis by emphasizing their \emph{permissiveness}---the ability to capture a wide range of admissible environment behaviors. We study permissive assumptions in two key settings: (a) interactions among multiple discrete components in distributed systems, and (b) interactions between high-level logical controllers and low-level physical dynamics in hybrid systems. In both settings, we develop theoretical and algorithmic foundations for computing and exploiting permissive assumptions to enable new design paradigms for logical controller synthesis. For distributed systems, we define permissiveness as capturing all cooperative behaviors of other components that enable a controller to satisfy its specification. We present an algorithm for computing such assumptions in monolithic systems and extend it to distributed systems via a negotiation-based framework that iteratively constructs permissive assume-guarantee contracts for each component. These contracts enable decentralized synthesis and are applied to human-robot interaction, allowing robots to cooperate with humans whenever possible and request cooperation only when necessary. For hybrid systems, we utilize permissive assumptions on the plant model---the abstract representation of physical dynamics---to address three key challenges. To enable seamless adaptation of controllers to changing logical contexts, i.e., changes in high-level goals or tasks, we introduce a novel synthesis framework that utilizes \emph{persistent live groups}, a class of assumptions capturing liveness properties of continuous dynamics. To improve scalability to large or uncertain plant models, we develop \emph{universal controllers} where decisions are conditioned on branching-time assumptions called \emph{prophecies}, which are learned from representative models and efficiently verified at runtime on unseen plant models. Finally, to enhance robustness under uncertainty or partial violations of assumptions on the plant model, we introduce a robust semantics for branching-time temporal logics, enabling formal reasoning about controller behavior under such violations. Overall, this work enables correctness-by-construction synthesis while avoiding unnecessary conservatism, resulting in CPS that are more robust, scalable, and responsive. Satya Prakash Nayak doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13090 Thu, 30 Apr 2026 09:06:57 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13084 In modern diesel exhaust aftertreatment systems (EATS), combining a catalytic coating for selective NOx reduction (SCR) with a diesel particulate filter (DPF) enables simultaneous particulate filtration and NOx reduction. In such systems, soot regeneration is primarily influenced by the NO2 supply in the exhaust gas, particularly at low exhaust temperatures (250-400 °C). Several investigations found that in SCR-coated filters with urea-water solution (UWS) dosing upstream, particle oxidation is partially inhibited by NH3. However, at higher temperatures (>400 °C), this effect seems to be reduced. In this study, numerical modelling approaches based on engine test bench results are utilised to examine the impact of SCR reactivity on passive soot oxidation for a highly porous vanadium-coated SDPF. To identify the interaction mechanism between the SCR reaction and soot oxidation, further investigations were conducted using a filter with a washcoat without SCR-active component. The methodology for determining the reduction of soot oxidation with UWS dosing is based on measuring the CO concentration difference across the particulate filter. The experimental data were determined on a state-of-the-art 13.5-litre six-cylinder rail engine under varying operating conditions, including different soot loadings, UWS injection rates and temperatures. Results show significant reductions in passive soot oxidation rates at both low and high temperatures when NH3 is present. The diffusion of NO2 in the filter wall appears to be the determining factor for the reduction, indicating that the NO2 difference after and before the filter is not the only determining factor for the diffusion effect, but rather the concentration gradient in the filter wall. The findings highlight the complex interaction between SCR reactions and passive soot oxidation. Optimising the design of the EATS can avoid critical soot loads for many applications of particulate filters with SCR activity, even without active regeneration. Niklas Prchal; Andreas Wegmann; Werner Müller; Michael Günthner article https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13084 Wed, 29 Apr 2026 13:25:26 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13085 Als Folge des Klimawandels ist mit einer Zunahme und Intensivierung von Starkregenereignissen zu rechnen, wobei besonders hochversiegelte Stadtgebiete durch Starkregen und den daraus resultierenden Überflutungen gefährdet sind. Konventionelle städtische Entwässerungssysteme sind nicht darauf ausgelegt, außergewöhnliche und extreme Starkregenereignisse überflutungsfrei abzuleiten. Dezentrale Regenwasserbewirtschaftungsanlagen (RWBA) können eine Lösungsmöglichkeit sein, die Resilienz bestehender Entwässerungssysteme gegenüber Starkregenereignissen zu verbessern. Diese Arbeit untersucht modellgestützt die Wirksamkeit verschiedener RWBA – Versickerungsanlagen, Gründächer, Zisternentypen und modifizierte Straßenbäume – in einem städtischen Untersuchungsgebiet. Mithilfe eines gekoppelten 1D/2D-Simulationsmodells, in dem sowohl das Kanalnetz als auch die Gebietsoberfläche berücksichtigt werden und das die SWMM-LID-Ansätze zur Modellierung der RWBA einbezieht, wird die Überflutungsreduzierung quantifiziert und die Leistungsfähigkeit der Anlagen im Quervergleich bewertet. Dabei werden unterschiedliche Implementierungsgrade, Niederschlagsverteilungen, Regendauern, die räumliche Anordnung der RWBA sowie die Übertragbarkeit der Ergebnisse auf andere Einzugsgebiete analysiert. Der Leistungsvergleich der Anlagen zeigt, dass die auf T = 5 a dimensionierten Versickerungsanlagen auch bei einem einstündigen hundertjährlichen Ereignis (hN = 48,9 mm) das Überflutungsvolumen deutlich reduzieren. Mit zunehmender Niederschlagsintensität nimmt der relative Effekt der Anlagen ab, allerdings erzielen die auf T = 100 a dimensionierten Versickerungsanlagen selbst bei einem extremen einstündigen Regenereignis (hN = 100 mm) noch eine große Reduzierung. Insgesamt haben die intensiven Grün- und Retentionsdächer von allen untersuchten Anlagen den größten Effekt und können selbst das 100 mm Niederschlagsereignis zurückhalten. Die Leistung der extensiven Gründächer liegt geringfügig unter der auf T = 100 a bemessenen Mulden. Die Zisternen sind vergleichbar mit den auf T = 5 a bemessenen Mulden, wobei ihre Leistungsfähigkeit vom Füllstand zu Beginn des Niederschlagsereignisses abhängt. Retentionszisternen haben eine deutlich größere Wirkung als Zisternen und erzielen eine Leistung, die leicht unter den auf T = 100 a dimensionierten Mulden liegt. Hydrologisch optimierte Baumstandorte und Baumrigolen zeigen den geringsten Effekt und sind dadurch selbst bei hohen Implementierungsgraden nicht ausreichend zum Überflutungsschutz geeignet. Die RWBA reagieren allgemein robust gegenüber verschiedenen Niederschlagsverteilungen und können Intensitätsspitzen abpuffern. Die Regendauer beeinflusst insbesondere die Leistungsfähigkeit von Versickerungsanlagen, die bei langanhaltendem Niederschlag auf durchlässigen Böden besonders wirksam sind. Die räumliche Anordnung spielt eine entscheidende Rolle: Eine gezielte Platzierung um Überflutungsschwerpunkte maximiert die Überflutungsreduzierung. Der Effekt der RWBA zur Überflutungsminderung kann nur bedingt auf andere Einzugsgebiete übertragen werden. Dennoch können die Ergebnisse für eine erste Priorisierung geeigneter RWBA in neuen Gebieten dienen, da die relative Wirksamkeit der Systeme gebietsunabhängig vergleichbar bleibt. Jonas Neumann doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13085 Wed, 29 Apr 2026 12:46:53 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/8993 Membrane proteins exert a multitude of essential functions in the cell, that frequently require interaction partners. In particular, for signalling with the second messenger c-di-GMP, protein-protein interactions are considered crucial. Also, in P. aeruginosa - a model organism for biofilm formation and infection - the majority of c-di-GMP synthesizing or degrading enzymes are membrane proteins. In the first part of this thesis, membrane proteins in P. aeruginosa PAO1 were investigated in a global approach. A native membrane-protein library was created through the formation of native nanodiscs by using amphiphilic polymers. The library was characterized by testing for reproducible and stable extraction of membrane proteins, coverage of the membrane proteome, and the capability to detect protein–protein interactions within a lipid-bilayer environment as well as membrane-bound protein complexes. In addition, membrane-associated proteins involved in c-di-GMP signalling and their interaction partners were investigated in more detail. To this end, a set of more than 20 described protein complexes was used to validate global analyses for the prediction of novel protein-protein interactions. Although elution profiles indicated preservation of the membrane complexes, the dataset was not feasible for protein interaction prediction. In the second part of the thesis, the membrane-integrated phosphodiesterase NbdA was investigated for its role in the c-di-GMP network. The current model for c-di-GMP signalling suggests the organisation of local signalling supermodules alongside global factors for specific functions in the cell. Thus, the protein NbdA was tested for protein-protein interaction partners in P. aeruginosa, either by a pulldown assay following mass spectrometry for novel candidate identification, or by bacterial adenylate cyclase two hybrid (B2H) assay for candidate verification. Out of more than 400 novel candidate proteins, five candidates were selected for further validation. The interaction with four proteins, PilB, SadC, CzcR and PA4200 was confirmed in a B2H assay. Moreover, the influence of NbdA on the global c-di-GMP level was tested. Therefore, either a markerless nbdA deletion mutant or overexpression strains were tested. To find out more about the role of the individual domains of NbdA, also global c-di-GMP levels of protein variant overproduction mutants was assayed. Although overexpression of full-length nbdA resulted in reduced global c-di-GMP levels indicating a PDE activity in vivo, the overproduction of truncated protein variants of NbdA resulted in unexpected c-di-GMP levels. In previous studies a possible role of the MHYT domain in cell elongation as well as growth on solid media was observed. To further test for the specificity of these observations, other MHYT domain containing proteins were tested for similar phenotypes in P. aeruginosa. Indeed, the phenotypes were specific for the MHYT domain of NbdA. Previous studies suggested an influence of NbdA overexpression on type IV pili (T4P), thus pili formation was tested in a phage assay and by atomic force microscopy (AFM). Further, the co-localisation of NbdA with pili components was tested by confocal laser scanning microscopy (CLSM) to determine whether NbdA is located at the piliated pole. The findings on NbdA support the model of complex but highly specific c-di-GMP signalling in P. aeruginosa. Anna Scherhag doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/8993 Wed, 29 Apr 2026 10:24:57 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13083 Driven by rising global energy demand and the urgent need to reduce carbon emissions, large-scale electrification has become a critical objective – particularly through the integration of renewable energy sources and energy storage systems. These technologies are inherently Direct Current (DC) in nature, challenging the long-standing dominance of Alternating Current (AC) infrastructure and naturally promoting a structural change towards DC and hybrid AC/DC power systems. This transformation is made feasible by advancements in power electronics, where multilevel converter topologies such as the Modular Multilevel Converter (MMC) may play a key enabling role due to their scalability, efficiency, and operational flexibility. This thesis explores two innovative capabilities of the MMC that enhance its functionality as an interconnecting element between distinct power networks. The first contribution introduces the concept of power decoupling between AC and DC grids. By leveraging the MMC’s flexible energy storage, the system enables independently shaped transient responses on both grid sides–offering a valuable opportunity to strengthen the interface between weak or mismatched networks. A hierarchical control structure is developed, combining Input-Output Feedback Linearization (IOFL) based controller, an extended disturbance observer, and a 2-Degree-of-Freedom (DOF) outer loop controller, validated through hardware implementation on a laboratory MMC prototype. A long-horizon Model Predictive Controller (MPC) is also introduced to handle system constraints, with its real-time feasibility evaluated in a Processorin-the-Loop (PiL) environment. The second contribution presents a high stepdown MMC-based DC to DC Converter (DC-DC) converter designed specifically for heavy-duty agricultural electrification, a sector traditionally difficult to electrify. In this application, a Medium-Voltage Direct Current (MVDC) microgrid supplies power to mobile agricultural machines. The converter uses an unconventional configuration of permanently inserted submodules to achieve transformerless operation and increased power density. A 300 kW hardware demonstrator is designed to experimentally validate the converter operation. A reduced-order model is developed to support the design of an adaptive controller, capable of maintaining a stable and uniformly responsive behavior under rapidly changing load conditions. In summary, this work demonstrates how the MMC – when paired with advanced control strategies can be a critical component of for future grid architectures and enable electrification in challenging applications. The proposed approaches contribute to the development of robust, flexible, and scalable power conversion systems essential for realizing the next generation of energy infrastructure. Pedro Leal dos Santos doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13083 Tue, 28 Apr 2026 11:45:34 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13082 Amtliche Bekanntmachung der RPTU Nr.4/28.04.2026 periodicalpart https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13082 Tue, 28 Apr 2026 11:34:36 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13075 Research on organizational path dependence often overlooks the self-reinforcing mechanisms at its core. This study examines how these mechanisms develop and persist by applying a practice-based perspective centered on everyday organizing. Drawing on a qualitative single-case study of a multinational logistics and storage company undergoing an organization wide transformation, the analysis identifies six recurring practices (inquiring, framing, mobilizing, innovating, structuring and deciding) that constitute the four mechanisms of learning, coordination, complementarity and adaptive expectations. These practices form specific constellations that give the self-reinforcing mechanisms a recognizable gestalt. As practice intensities and effects shift during the path development process, the mechanisms appear as practice-effects rooted in situated doings and sayings rather than autonomous forces. The study also identifies a dual feedback logic in which positive feedback stabilizes emerging patterns, while inquiry-based negative feedback propels the process forward and keeps the path adaptive; a form of distributed agency in which attention and energy travel across practices; the insight that stability and change are produced by the same practices; and an understanding of lock-in as a continuum of practice thickening and cognitive sedimentation. This research therefore advances a 'life lived forward perspective' on path dependence that goes beyond ex-post explanations. It specifies the micro-foundations of self-reinforcement, offers a practice-based account of how organizational paths take shape over time, and provides actionable insights for managers on how to recognize, monitor and redirect self-reinforcing dynamics during strategic transformation. Julia Todea doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13075 Fri, 24 Apr 2026 06:38:49 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13073 Diese Masterarbeit untersucht die Tabuisierung von Sterben und Tod in Gesprächsprozessen der gesundheitlichen Versorgungsplanung (GVP) in Einrichtungen der Eingliederungshilfe aus einer systemtheoretischen Perspektive. Im Zentrum steht die Frage, wie kommunikative Prozesse durch gesellschaftlich und organisational stabilisierte Tabumechanismen strukturiert werden und welche Folgen sich daraus für die Thematisierung existenzieller Lebensereignisse ergeben. Ausgehend von der Annahme, dass Tabus als funktionale, normierende Erwartungsstrukturen innerhalb sozialer Systeme operieren, wird Tabuisierung als ein Mechanismus der Reduktion von Komplexität und Affektregulation rekonstruiert. Sie erzeugt Kommunikationslatenz, indem bestimmte Themen – trotz ihrer objektiven Relevanz – systematisch aus dem Bereich des Sagbaren ausgeschlossen werden. Dies führt zu Beobachtungs- und Thematisierungslücken, die insbesondere in hochsensiblen Kommunikationskontexten wie der gesundheitlichen Versorgungsplanung wirksam werden. Die Arbeit zeigt, dass Sterben und Tod als kommunikative Themen eine ambivalente Funktion einnehmen: Einerseits ermöglichen sie die Reduktion von Unsicherheit und die Antizipation zukünftiger Entscheidungsbedarfe, andererseits sind sie mit hohen Thematisierungsschwellen verbunden, die ihre Integration in Interaktionsprozesse erschweren. In der Folge entstehen Spannungsfelder zwischen dem Anspruch auf Selbstbestimmung und den strukturellen sowie intrapsychischen Barrieren der Kommunikation. Auf Grundlage empirischer Erhebungen unter GVP-Beratenden werden fördernde und hemmende Faktoren der Thematisierung systematisch analysiert. Dabei wird deutlich, dass neben strukturellen Bedingungen – wie Zeitressourcen, räumlichen Settings und organisationalen Routinen – insbesondere die Qualität der Beziehung, die Ausgestaltung der Gesprächsführung sowie biografische und affektive Dispositionen der Beteiligten entscheidend sind. Offene Kommunikationsprozesse erweisen sich als voraussetzungsvoll und abhängig von Vertrauen, reflexiver Haltung und der Fähigkeit, Ambiguität sowie emotionale Belastung auszuhalten. Die Ergebnisse verweisen darauf, dass Tabuisierung nicht ausschließlich als dysfunktionale Einschränkung zu verstehen ist, sondern auch eine stabilisierende Funktion für soziale Systeme erfüllt, indem sie vor Überforderung schützt. Gleichzeitig bedarf es eines reflektierten Umgangs mit diesen Mechanismen, um Kommunikationsräume zu eröffnen, in denen existenzielle Themen bearbeitbar werden. Die Arbeit leistet einen Beitrag zur Schließung bestehender Forschungslücken, indem sie die Perspektive der GVP-Beratenden systematisch einbezieht und die Wechselwirkungen zwischen individueller Haltung, organisationalen Strukturen und gesellschaftlichen Tabus herausarbeitet. Sie bietet damit theoretisch fundierte und praxisrelevante Ansatzpunkte zur Weiterentwicklung einer kommunikationssensiblen Versorgungskultur im Kontext von Sterben und Tod. Kerstin Deckert masterthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13073 Fri, 24 Apr 2026 06:32:35 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13074 This study addresses the challenge of consistently transferring atomistic parameters of the C–C bond into phenomenological material characteristics within the framework of continuum mechanics. Particular attention is given to determining the effective transverse diameter of the covalent C–C bond in carbon nanostructures. The dependence of this diameter on Poisson’s ratio ν is examined, and the influence of the interatomic stiffness constants kr, kθ and kτ is systematically analyzed. Classical representative-volume models of the C–C bond based on the Euler–Bernoulli beam hypothesis violate thermodynamic stability conditions and lead to nonphysical Poisson’s ratio values exceeding 0.5, due to the neglect of shear deformation effects. To overcome this limitation, an approach based on Timoshenko beam theory is proposed, accounting for both bending and shear deformations. This approach enables estimation of energetically equivalent states between the phenomenological representative volume and the corresponding atomistic C–C bond model. As a result, a sixth-order algebraic equation is derived linking the effective bond diameter, the Poisson’s ratio, and the molecular mechanics force constants. Analysis of this equation reveals a narrow range of effective bond diameters and Poisson’s ratios for which thermodynamic stability conditions are satisfied. Within this range, physically consistent macroscopic material parameters can be directly expressed in terms of atomistic force constants. Oleksandr Hondliakh; Sergiy Antonyuk; Marc Weirich; Simon Paas article https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13074 Fri, 24 Apr 2026 06:28:26 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13072 Scattering resonances are fundamental to many areas of physics, occurring across a wide range of energy scales. In ultracold quantum gases, magnetic Feshbach resonances have transformed quantum many-body research by enabling precise interaction control between atoms. Here, we demonstrate unprecedented control to engineer Feshbach resonances at tunable positions via Floquet driving in a lithium-6 (^{6}Li) atom gas, achieved through strong magnetic field modulation at megacycles per second frequencies. This periodic modulation creates scattering resonances whenever dressed molecular levels cross the atomic threshold. By adding a second modulation at twice the base frequency, we tune the asymmetry of resonance loss profiles and suppress two-body losses from Floquet heating. This technique enhances control over atomic interactions, expanding possibilities for quantum simulations of complex systems and studies of exotic quantum phases. Alexander Guthmann; Felix Lang; Louisa Marie Kienesberger; Sian Barbosa; Artur Widera article https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13072 Thu, 23 Apr 2026 12:18:38 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13063 EPS15 and its paralog EPS15R are endocytic adaptor proteins best known for initiating clathrin-mediated endocytosis and facilitating the uptake of EGFR, yet their neuronal roles have remained unclear. This thesis establishes that both proteins are critical components for synaptic receptor regulation, neurodevelopment, and ventricular homeostasis, suggesting that their functions are closely integrated with broader processes essential for brain development and maintenance. Comprehensive analyses showed that EPS15 and EPS15R are broadly expressed across the brain but display a distinct regional enrichment and a progressive postnatal upregulation. Both localize to pre- and postsynaptic compartments, supporting a dual function in synaptic vesicle recycling and neurotransmitter receptor trafficking. Their interaction with the AMPA receptor subunit GluA1, and the resulting GluA1 surface accumulation upon loss of EPS15/EPS15R, identify them as key regulators of AMPAR endocytosis with a potential influence on excitatory balance. In contrast, transferrin receptor uptake remained unaffected, indicating that global clathrin-mediated endocytosis is preserved. Unbiased proteomic analysis defined the molecular networks through which EPS15 and EPS15R operate. Both interactomes were strongly enriched for canonical endocytic components, confirming their roles in vesicle formation and cargo selection. However, in addition, the EPS15R interactome revealed unique partners such as CALCOCO1 and SEC16A, implicating it in autophagy and ER-associated membrane trafficking. These findings suggest a non-canonical role for EPS15R as a scaffold linking endocytic, secretory, and degradative pathways. At the organismal level, the forebrain-specific loss of EPS15 and EPS15R resulted in growth deficits, seizures, hind limb clasping, behavioral changes, alterations in brain anatomy, and reduced postnatal survival, highlighting their importance for overall brain function. Structural analyses revealed cortical and hippocampal lamination defects closely resembling those observed upon disruption of Reelin signaling. Supporting a mechanistic link, our biochemical analyses demonstrated that EPS15R physically associates with the Reelin receptor ApoER2, suggesting that it may participate in the trafficking or stabilization of Reelin receptor complexes, thereby influencing neuronal positioning and cortical layering during development. In addition, EPS15/15R knockout mice developed ventriculomegaly. Cell culture experiments revealed defective ependymal differentiation and multiciliogenesis as potential cause for this phenotype. Given that proper ependymal maturation requires controlled EGFR downregulation and Notch signaling modulation, the loss of EPS15/15R might disrupts these processes, thereby leading to impaired differentiation and compromised ventricular integrity. Together, these findings identify EPS15 and EPS15R as multifaceted adaptors that integrate endocytic trafficking with neuronal signaling and brain morphogenesis. By ensuring proper receptor internalization, neuronal lamination, and ependymal differentiation, they safeguard both the synaptic and structural integrity of the brain. Jasmeet Kaur Shergill doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13063 Wed, 22 Apr 2026 12:35:29 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13070 In the rapidly evolving interdisciplinary field of quantum information science and technology, a major obstacle is the need to understand advanced mathematics to solve complex problems. Current findings in educational research suggest that incorporating visualizations into problem-solving settings can have beneficial effects on students’ performance and cognitive load compared to relying solely on symbolic problem-solving content. Visualizations like the (dimensional) circle notation enable us to represent not only single-qubit but also more complex multiqubit states, entanglement, and quantum algorithms. In this pilot study, we aim to take an initial step toward identifying the contexts in which students benefit from the presentation of visualizations of single- and multiqubit systems in addition to mathematical formalism. For this purpose, we propose a set of test items and a comprehensive methodology to assess students’ performance and cognitive load when solving problems. This is a pilot investigation with a large breadth of questions intended to generate hypotheses and guide larger-scale, more focused studies in the future. Specifically, we compare two approaches: using the mathematical-symbolic Dirac notation alone and using it in combination with the (dimensional) circle notation. In surveys in one-, two- and three-qubit systems, we gather qualitative data from five, five and two think-aloud interviews, identifying problems that students encounter and their problem-solving strategies. In addition, we analyze quantitative data (performance and cognitive load) from 23, 27, and 17 participants in surveys on one-, two-, and three-qubit systems recruited mainly from our quantum computing lectures. We find that most of the test items are appropriate for a heterogeneous target group, as they can differentiate between participants in terms of performance and time taken. In general, the A-B crossover structure of the study is suitable for investigating the benefits of visualization for problem solving with regard to length and feasibility. Future studies should, however, be narrower in scope, given the observable dependence on student characteristics and context, with particular interest lying in the further investigation of the Hadamard gate, the CNOT gate, and entanglement in multiqubit systems. Jonas Bley; Eva Rexigel; Alda Arias; Maximilian Kiefer-Emmanouilidis; Lars Krupp; Steffen Steinert; Nikolas Longen; Paul Lukowicz; Stefan Küchemann; Jochen Kuhn; Artur Widera article https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13070 Wed, 22 Apr 2026 11:44:03 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13071 One of the hallmarks of topological systems is the robust quantization of particle transport. It is the origin of the integer-valued quantum Hall conductivity and a potential tool for quantum information technology. Recent experiments on topological pumps constructed by using arrays of photonic waveguides and described by the (lattice-translational invariant) Aubry-André-Harper model, have demonstrated both integer and fractional transport of lattice solitons. In these systems, a background medium mediates interactions between photons via a Kerr nonlinearity and leads to the formation of self-bound multiphoton states. Upon increasing the interaction strength, a sequence of transitions was observed from a phase with integer transport in a pump cycle through different phases of fractional transport to a phase with no transport. We here present a quantum description of topological pumps of self-bound many-particle states in terms of an effective Hamiltonian of their center-of-mass (c.m.) motion, which allows one to introduce an effective band structure \( E_\mu(K) \) with \( K \) being the c.m. momentum and to classify topological phases in terms of generalized symmetries. We provide an explicit analytic expression of the effective Hamiltonian for few particles in the strong interaction limit and present numerical results in the more general case. We identify a topological invariant, an effective single-particle Chern number, which fully governs the soliton transport. Increasing the interaction strength in the Aubry-André-Harper model leads to a successive merging of c.m. bands, which is the origin of the observed sequence of topological phase transitions and also the potential breakdown of topological quantization for some interaction strength. Julius Bohm; Hugo Gerlitz; Christina Jörg; Michael Fleischhauer article https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13071 Wed, 22 Apr 2026 10:29:46 +0200 https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13069 Change point tests are a common tool to identify structural changes in the distribution of time series. In recent years, there has been progress in detecting changes within times series in countable spaces, e.g. the natural numbers. Such time series can be modeled by using Poisson-INARCH processes. Generally, it is assumed that changes occur as abrupt changes between stationary distributions. But in practice such changes often occur as a smooth transition, called gradual changes. To include such a behavior, we propose a new intensity function for Poisson-INARCH processes which makes gradual changes possible. We moreover propose a gradual change by adding a deterministic time dependent term on the intensity function. Properties as stationarity and a strong mixing property are investigated for both approaches. Under the alternative, convergence of estimators is ensured. We use those properties to prove consistency of tests based on both approaches under the null hypothesis and the alternative. We then analyze the quality of the models based on a comparative simulation study. Florian Schirra doctoralthesis https://kluedo.ub.rptu.de/frontdoor/index/index/docId/13069 Wed, 22 Apr 2026 09:01:19 +0200