11 Interfakultäre Einrichtungen

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/12

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Open Access
Addressing goal conflicts : new policy mixes for commercial land use management
(2022) Kosow, Hannah; Wassermann, Sandra; Bartke, Stephan; Goede, Paul; Grimski, Detlef; Imbert, Ines; Jenssen, Till; Laukel, Oliver; Proske, Matthias; Protzer, Jochen; Schumacher, Kim Philip; Siedentop, Stefan; Wagner-Endres, Sandra; Wittekind, Jürgen; Zimmermann, Karsten
Commercial land use management that focuses on a future-oriented urban and regional development must address multiple goals. Effective policy mixes need to simultaneously (1) improve city-regional and inter-municipal cooperation, (2) reduce land take, and (3) assure the long-term economic development of a region. Using the Northern Black Forest in Germany as a case study, we brought together planning and land use research with public policy analysis. We applied cross-impact balances (CIB) to build and analyze a participatory policy-interaction model. Together with a group of 12 experts, we selected effective individual measures to reach each of the three goals and analyzed their interactions. We then assessed the current policy mix and designed alternative policy mixes. The results demonstrate that current approaches to commercial land use management present internal contradictions and generate only little synergies. Implementing innovative measures on a stand-alone basis runs the risk of not being sufficiently effective. In particular, the current practice of competing for municipal marketing and planning of commercial sites has inhibiting effects. We identified alternative policy mixes that achieve all three goals, avoid trade-offs, and generate significant synergy effects. Our results point towards a more coherent and sustainable city-regional (commercial) land-use governance.
Open Access
AGRI|gen : analysis and design of a parametric modular system for vertical urban agriculture
(2023) Ghazal, Iyad; Mansour, Reema; Davidová, Marie
While many studies were done about green facades’ thermal performance, limited studies were done about green facades for productive farming. Most focused only on one facade or building. According to that, this research questioned what the potentials of farming on facades and roofs in an entire neighbourhood are and what could such a farming system looks like, and what it costs. To address these questions, a literature review about urban farming and possible crops was done. A neighbourhood of 22 multi-floor residential buildings in Nablus\Palestine, was chosen as a case study, and two parametric tools, one for analysis (AGRI|gen\Analysis) and another for design (AGRI|gen\design) were developed and implemented. The study found that in the chosen neighbourhood, existing facades can provide about 28,500 m2 of farming area, but only half of the facades and all of the roofs were suitable for daylight-based farming. Tomatoes and cucumbers can be farmed on 25% and 33% of the facades, respectively, to fulfil about 350% and 237% of tomatoes and cucumbers consumption by the same neighbourhood simultaneously. Roofs were found to be more suitable for high DLI-requiring plants like sweet peppers as they can produce more than 315 times the local consumption. In terms of design, a modular adaptive facade system was designed to fit the neighbourhood to enhance the farming possibilities. The facade system needed about 40,824 modular units of which 73.3%, 10.1%, 8.7%, and 8% of them were LED, PV, Sensor, and fan units respectively, with an average system cost of about $55.2\m2 and a total cost of $1.7M. Finally, a comparison between the system and a proposed vertical farm building in the same region was done, and then related recommendations by the researcher were suggested. This research highlights the potential for productive farming on facades and roofs, which could contribute to sustainable and resilient cities.
Open Access
Akteurskonflikten in der Energiewende gegensteuern : Impulse für die Instrumentenentwicklung : Impulspapier - SyKonaS
(Stuttgart : Verbundvorhaben SyKonaS, Koordination: Zentrum für interdisziplinäre Risiko- und Innovationsforschung der Universität Stuttgart (ZIRIUS), 2024) Jaschek, Carolin; León, Christian D.; Liebhart, Laura; Püttner, Andreas; Wolf, Patrick; Klug, Katharina; Otto, Jonas; Wegner, Nils; Dreyer, Marion; Dreyer, Marion (Redaktion); Dratsdrummer, Frank (Redaktion); Witzel, Bianca (Redaktion)
Dieses Impulspapier adressiert gesellschaftliche Energiewendekonflikte als politisches und rechtliches Handlungsfeld und präsentiert eine Reihe von Instrumentenoptionen für die Bearbeitung von bereits bestehenden und möglichen zukünftigen Akteurskonflikten im Kontext der Energiewende. Der Fokus liegt auf der Konfliktbearbeitung bei der Transformation des Stromsektors und auf drei ausgewählten Konfliktfeldern: Gerechtigkeit und Kosten-/Lastenverteilung, Flächennutzung und Partizipation.
Open Access
Analyzing the generalization capabilities of a hybrid hydrological model for extrapolation to extreme events
(2025) Acuña Espinoza, Eduardo; Loritz, Ralf; Kratzert, Frederik; Klotz, Daniel; Gauch, Martin; Álvarez Chaves, Manuel; Ehret, Uwe
Data-driven techniques have shown the potential to outperform process-based models in rainfall–runoff simulation. Recently, hybrid models, which combine data-driven methods with process-based approaches, have been proposed to leverage the strengths of both methodologies, aiming to enhance simulation accuracy while maintaining a certain interpretability. Expanding the set of test cases to evaluate hybrid models under different conditions, we test their generalization capabilities for extreme hydrological events, comparing their performance against long short-term memory (LSTM) networks and process-based models. Our results indicate that hybrid models show performance similar to that of the LSTM network for most cases. However, hybrid models reported slightly lower errors in the most extreme cases and were able to produce higher peak discharges.
Open Access
Assessing the immediate effects of detached mindfulness on repetitive negative thinking and affect in daily life : a randomized controlled trial
(2024) Bolzenkötter, Teresa; Bürkner, Paul-Christian; Zetsche, Ulrike; Schulze, Lars
Objectives. Repetitive negative thinking (RNT) is a problematic thinking style that is related to multiple mental disorders. Detached mindfulness is a technique of metacognitive therapy that aims to reduce RNT. Our study set out to investigate the immediate effects of detached mindfulness in daily life. Methods. Participants with elevated trait RNT ( n = 50) were prompted to engage in detached mindfulness exercises three times a day for 5 consecutive days. Immediate effects on RNT and affect were assessed 15 and 30 min after each exercise using experience sampling methodology. We compared the effects of this exercise phase to (1) a 5-day non-exercise baseline phase and (2) a different group of participants that engaged in an active control exercise ( n = 50). Results. Results of Bayesian multilevel models showed that, across groups, improvements in RNT, negative affect, and positive affect were stronger during the exercise phase than during the non-exercise baseline phase (RNT after 15 min: b = -0.26, 95% CI = [-0.38, -0.14]). However, the two exercise groups did not differ in these improvements (RNT after 15 min: b = 0.02, 95% CI = [-0.22, 0.27]). Thus, the detached mindfulness and the active control exercises resulted in similar effects on RNT and affect in daily life. Conclusions. Results of this study imply that there was no additional benefit of having participants observe their thoughts detached and non-judgmentally, compared to excluding these assumed mechanisms of action as done for the active control group. We discuss possible reasons for the non-difference between the groups.
Open Access
Association between vitamin D status and eryptosis : results from the German National Cohort study
(2023) Ewendt, Franz; Schmitt, Marvin; Kluttig, Alexander; Kühn, Julia; Hirche, Frank; Kraus, Frank B.; Ludwig-Kraus, Beatrice; Mikolajczyk, Rafael; Wätjen, Wim; Bürkner, Paul-Christian; Föller, Michael; Stangl, Gabriele I.
Vitamin D, besides its classical effect on mineral homeostasis and bone remodeling, can also modulate apoptosis. A special form of apoptosis termed eryptosis appears in erythrocytes. Eryptosis is characterized by cell shrinkage, membrane blebbing, and cell membrane phospholipid disorganization and associated with diseases such as sepsis, malaria or iron deficiency, and impaired microcirculation. To our knowledge, this is the first study that linked vitamin D with eryptosis in humans. This exploratory cross-sectional trial investigated the association between the vitamin D status assessed by the concentration of plasma 25-hydroxyvitamin D (25(OH)D) and eryptosis. Plasma 25(OH)D was analyzed by LC-MS/MS, and eryptosis was estimated from annexin V-FITC-binding erythrocytes by FACS analysis in 2074 blood samples from participants of the German National Cohort Study. We observed a weak but clear correlation between low vitamin D status and increased eryptosis ( r = − 0.15; 95% CI [− 0.19, − 0.10]). There were no differences in plasma concentrations of 25(OH)D and eryptosis between male and female subjects. This finding raises questions of the importance of vitamin D status for eryptosis in terms of increased risk for anemia or cardiovascular events.
Open Access
Coordinating with a robot partner affects neural processing related to action monitoring
(2021) Czeszumski, Artur; Gert, Anna L.; Keshava, Ashima; Ghadirzadeh, Ali; Kalthoff, Tilman; Ehinger, Benedikt V.; Tiessen, Max; Björkman, Mårten; Kragic, Danica; König, Peter
Robots start to play a role in our social landscape, and they are progressively becoming responsive, both physically and socially. It begs the question of how humans react to and interact with robots in a coordinated manner and what the neural underpinnings of such behavior are. This exploratory study aims to understand the differences in human-human and human-robot interactions at a behavioral level and from a neurophysiological perspective. For this purpose, we adapted a collaborative dynamical paradigm from the literature. We asked 12 participants to hold two corners of a tablet while collaboratively guiding a ball around a circular track either with another participant or a robot. In irregular intervals, the ball was perturbed outward creating an artificial error in the behavior, which required corrective measures to return to the circular track again. Concurrently, we recorded electroencephalography (EEG). In the behavioral data, we found an increased velocity and positional error of the ball from the track in the human-human condition vs. human-robot condition. For the EEG data, we computed event-related potentials. We found a significant difference between human and robot partners driven by significant clusters at fronto-central electrodes. The amplitudes were stronger with a robot partner, suggesting a different neural processing. All in all, our exploratory study suggests that coordinating with robots affects action monitoring related processing. In the investigated paradigm, human participants treat errors during human-robot interaction differently from those made during interactions with other humans. These results can improve communication between humans and robot with the use of neural activity in real-time.
Open Access
Cultural environments with more-than-human perspectives : prototyping through research and training
(2023) Davidová, Marie; Barath, Shany; Dickinson, Susannah
Open Access
Daily emotion regulation in major depression and borderline personality disorder
(2023) Zetsche, Ulrike; Bürkner, Paul-Christian; Bohländer, Julian; Renneberg, Babette; Roepke, Stefan; Schulze, Lars
Emotional disturbances are an inherent aspect of most mental disorders and possibly driven by impaired emotion regulation. In the present study, we examined how exactly affected individuals differ from healthy individuals in regulating their emotions and whether individuals suffering from different mental disorders face similar or distinct difficulty in emotion regulation. We overcome earlier methodological constraints by using a 7-day experience sampling assessing the employment and effectiveness of six regulation strategies real time in 55 individuals with current major depressive disorder, 52 individuals with borderline personality disorder (BPD), and 55 healthy individuals. All participants were female. Both clinical groups employed rumination and suppression more often and acceptance less often than healthy individuals. Depressed individuals ruminated even more often than individuals with BPD. Expressive suppression and rumination showed negative effects on subsequent emotions in all groups. Remarkably, both clinical groups were able to benefit from adaptive regulation strategies if they did select them.
Open Access
Degradation rate location dependency of photovoltaic systems
(2020) Frick, Alexander; Makrides, George; Schubert, Markus; Schlecht, Matthias; Georghiou, George E.
A main challenge towards ensuring improved lifetime performance and reduction of financial risks of photovoltaic (PV) technologies remains the accurate degradation quantification of field systems and the dependency of this performance loss rate to climatic conditions. The purpose of this study is to address these technological issues by presenting a unified methodology for accurately calculating the degradation rate (𝑅𝐷) of PV systems and provide evidence that degradation mechanisms are location dependent. The method followed included the application of data inference and time series analytics, in the scope of comparing the long-term 𝑅𝐷 of different crystalline Silicon (c-Si) PV systems, installed at different climatic locations. The application of data quality and filtering steps ensured data fidelity for the 𝑅𝐷 analysis. The yearly 𝑅𝐷 results demonstrated that the adopted time series analytical techniques converged after 7 years and were in close agreement to the degradation results obtained from indoor standardized procedures. Finally, the initial hypothesis that the 𝑅𝐷 is location dependent was verified, since the multicrystalline silicon (multi-c-Si) systems at the warm climatic region exhibited higher degradation compared to the respective systems at the moderate climate. For the investigated monocrystalline silicon (mono-c-Si) systems the location-dependency is also affected by the manufacturing technology.
Open Access
Editorial - rapid, reproducible, and robust environmental modeling for decision support : worked examples and open-source software tools
(2023) White, Jeremy T.; Fienen, Michael N.; Moore, Catherine R.; Guthke, Anneli
Open Access
The effectiveness of cognitive behavioural therapy for social anxiety disorder in routine clinical practice
(2022) Morina, Nexhmedin; Seidemann, Julienne; Andor, Tanja; Sondern, Lisa; Bürkner, Paul‐Christian; Drenckhan, Isabelle; Buhlmann, Ulrike
Numerous randomized controlled trials have shown cognitive behaviour therapy (CBT) to be effective in treating social anxiety disorder (SAD). Yet, less is known about the effectiveness of CBT for SAD conducted by psychotherapists in training in routine clinical practice. In this study, 231 patients with SAD were treated with CBT under routine conditions and were examined at pre‐ and post‐treatment as well as at 6 and 12 months follow‐up. We applied self‐reports to assess symptoms of SAD (defined as primary outcome), depression and psychological distress (defined as secondary outcome). We conducted both completer and intent‐to‐treat analyses and also assessed the reliability of change with the reliable change index. Results revealed significant reductions in symptoms of SAD between pre‐ and post‐assessments, with effect sizes ranging from d = 0.9 to 1.2. Depending on the SAD specific questionnaire applied, 47.8% to 73.5% of the sample showed a reliable positive change, whereas 1.9% to 3.8% showed a reliable negative change. Depressive symptoms and psychological distress also decreased significantly from pre‐ to post‐assessment, with large effect sizes. Significant treatment gains regarding both primary and secondary outcomes were further observed at 6 and 12 months follow‐up. The current findings based on a large sample of patients suggest that psychotherapists in CBT training working under routine conditions can effectively treat symptoms of SAD, depression and psychological distress.
Open Access
Efficient wildland fire simulation via nonlinear model order reduction
(2021) Black, Felix; Schulze, Philipp; Unger, Benjamin
We propose a new hyper-reduction method for a recently introduced nonlinear model reduction framework based on dynamically transformed basis functions and especially well-suited for transport-dominated systems. Furthermore, we discuss applying this new method to a wildland fire model whose dynamics feature traveling combustion waves and local ignition and is thus challenging for classical model reduction schemes based on linear subspaces. The new hyper-reduction framework allows us to construct parameter-dependent reduced-order models (ROMs) with efficient offline/online decomposition. The numerical experiments demonstrate that the ROMs obtained by the novel method outperform those obtained by a classical approach using the proper orthogonal decomposition and the discrete empirical interpolation method in terms of run time and accuracy.
Open Access
An empirical study of Linespots : a novel past‐fault algorithm
(2021) Scholz, Maximilian; Torkar, Richard
This paper proposes the novel past‐faults fault prediction algorithm Linespots, based on the Bugspots algorithm. We analyse the predictive performance and runtime of Linespots compared with Bugspots with an empirical study using the most significant self‐built dataset as of now, including high‐quality samples for validation. As a novelty in fault prediction, we use Bayesian data analysis and Directed Acyclic Graphs to model the effects. We found consistent improvements in the predictive performance of Linespots over Bugspots for all seven evaluation metrics. We conclude that Linespots should be used over Bugspots in all cases where no real‐time performance is necessary.
Open Access
The ethics of sustainable AI : why animals (should) matter for a sustainable use of AI
(2023) Bossert, Leonie N.; Hagendorff, Thilo
Technologies equipped with artificial intelligence (AI) influence our everyday lives in a variety of ways. Due to their contribution to greenhouse gas emissions, their high use of energy, but also their impact on fairness issues, these technologies are increasingly discussed in the “sustainable AI” discourse. However, current “sustainable AI” approaches remain anthropocentric. In this article, we argue from the perspective of applied ethics that such anthropocentric outlook falls short. We present a sentientist approach, arguing that the normative foundation of sustainability and sustainable development - that is, theories of intra- and intergenerational justice - should include sentient animals. Consequently, theories of sustainable AI must also be non-anthropocentric. Moreover, we investigate consequences of our approach for applying AI technologies in a sustainable way.
Open Access
Fairness hacking : the malicious practice of shrouding unfairness in algorithms
(2024) Meding, Kristof; Hagendorff, Thilo
Fairness in machine learning (ML) is an ever-growing field of research due to the manifold potential for harm from algorithmic discrimination. To prevent such harm, a large body of literature develops new approaches to quantify fairness. Here, we investigate how one can divert the quantification of fairness by describing a practice we call “fairness hacking” for the purpose of shrouding unfairness in algorithms. This impacts end-users who rely on learning algorithms, as well as the broader community interested in fair AI practices. We introduce two different categories of fairness hacking in reference to the established concept of p-hacking. The first category, intra-metric fairness hacking, describes the misuse of a particular metric by adding or removing sensitive attributes from the analysis. In this context, countermeasures that have been developed to prevent or reduce p-hacking can be applied to similarly prevent or reduce fairness hacking. The second category of fairness hacking is inter-metric fairness hacking. Inter-metric fairness hacking is the search for a specific fair metric with given attributes. We argue that countermeasures to prevent or reduce inter-metric fairness hacking are still in their infancy. Finally, we demonstrate both types of fairness hacking using real datasets. Our paper intends to serve as a guidance for discussions within the fair ML community to prevent or reduce the misuse of fairness metrics, and thus reduce overall harm from ML applications.
Open Access
FFT-based homogenization at finite strains using composite boxels (ComBo)
(2022) Keshav, Sanath; Fritzen, Felix; Kabel, Matthias
Computational homogenization is the gold standard for concurrent multi-scale simulations (e.g., FE2) in scale-bridging applications. Often the simulations are based on experimental and synthetic material microstructures represented by high-resolution 3D image data. The computational complexity of simulations operating on such voxel data is distinct. The inability of voxelized 3D geometries to capture smooth material interfaces accurately, along with the necessity for complexity reduction, has motivated a special local coarse-graining technique called composite voxels (Kabel et al. Comput Methods Appl Mech Eng 294: 168-188, 2015). They condense multiple fine-scale voxels into a single voxel, whose constitutive model is derived from the laminate theory. Our contribution generalizes composite voxels towards composite boxels (ComBo) that are non-equiaxed, a feature that can pay off for materials with a preferred direction such as pseudo-uni-directional fiber composites. A novel image-based normal detection algorithm is devised which (i) allows for boxels in the firsts place and (ii) reduces the error in the phase-averaged stresses by around 30% against the orientation cf. Kabel et al. (Comput Methods Appl Mech Eng 294: 168-188, 2015) even for equiaxed voxels. Further, the use of ComBo for finite strain simulations is studied in detail. An efficient and robust implementation is proposed, featuring an essential selective back-projection algorithm preventing physically inadmissible states. Various examples show the efficiency of ComBo against the original proposal by Kabel et al. (Comput Methods Appl Mech Eng 294: 168-188, 2015) and the proposed algorithmic enhancements for nonlinear mechanical problems. The general usability is emphasized by examining various Fast Fourier Transform (FFT) based solvers, including a detailed description of the Doubly-Fine Material Grid (DFMG) for finite strains. All of the studied schemes benefit from the ComBo discretization.
Open Access
Gestión de la Recarga del Acuífero: una contribución a la solución del problema del agua en Lima, Perú : informe final del proyecto NEWA-LIMA
(Stuttgart : Universität Stuttgart, 2025) Fesch, Katharina; Hügler, Michael; León, Christian D.; Perez, Hiraida; Stauder, Stefan; Xanke, Julian; Manrique, Elizabeth (Übersetzerin)
El proyecto NEWA-LIMA “Nuevos recursos hídricos y tratamiento innovador de aguas residuales para regiones metropolitanas áridas, tomando como ejemplo Lima, Perú”, financiado por el Ministerio del Ambiente de Alemania (BMUV) durante el período 2022 a 2024 tuvo como objetivo demostrar que la Recarga Gestionada de Acuíferos es un método natural y de bajo costo para el uso a largo plazo de los recursos hídricos subterráneos, contribuyendo de este modo a la solución de los problemas de agua en Lima. Lima es una de las regiones metropolitanas más áridas del mundo, por lo que el abastecimiento de agua para sus 10 millones de habitantes, así como para la industria y el comercio, representa un gran desafío que requerirá de inversiones significativas en los próximos años. Los ríos locales llevan agua solamente durante la época de avenida en los Andes y los recursos de agua subterránea son limitados. Este informe presenta las soluciones desarrolladas y los resultados obtenidos en este proyecto. Tras exhaustivas investigaciones preliminares, se construyó una planta piloto MAR en el terreno de una planta de tratamiento de aguas residuales (PTAR) en el valle del río Lurín. Constó de tres pozas de tierra para la infiltración de las aguas residuales tratadas, así como varios piezómetros. Fue operada en colaboración con la Empresa de Servicio de Agua Potable y Alcantarillado de Lima (SEDAPAL) durante un periodo de 17 meses. El rendimiento de depuración del paso por el suelo fue registrado mediante exhaustivos análisis microbiológicos y químicos del agua, incluidas sustancias antropogénicas y el innovador “análisis relacionado con el impacto” (WBA). Las investigaciones complementarias a pequeña escala con adsorción de carbón activado y ósmosis inversa evaluaron el uso de estas tecnologías avanzadas de tratamiento de agua. Se revisó el marco legal vigente y las implicaciones sociales de los proyectos MAR en Perú. La elaboración de un modelo local de aguas subterráneas y de un concepto para el uso de filtros percoladores en el tratamiento de aguas residuales sirvieron para definir recomendaciones respecto a una aplicación MAR a gran escala en el valle de Lurín.
Open Access
Higher-order iterative decoupling for poroelasticity
(2024) Altmann, Robert; Mujahid, Abdullah; Unger, Benjamin
For the iterative decoupling of elliptic–parabolic problems such as poroelasticity, we introduce time discretization schemes up to order five based on the backward differentiation formulae. Its analysis combines techniques known from fixed-point iterations with the convergence analysis of the temporal discretization. As the main result, we show that the convergence depends on the interplay between the time step size and the parameters for the contraction of the iterative scheme. Moreover, this connection is quantified explicitly, which allows for balancing the single error components. Several numerical experiments illustrate and validate the theoretical results, including a three-dimensional example from biomechanics.
Open Access
IDEA - towards an interactive tool that supports creativity sessions in automotive product development
(2023) Kaschub, Verena Lisa; Wechner, Reto; Krautmacher, Lara; Diers, Daniel; Bues, Matthias; Lossack, Ralf; Kloos, Uwe; Riedel, Oliver