Universität Stuttgart
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Item Open Access Movement in the digital world : interdisciplinary model, processes, and methods in digital motor-cognitive health promotion - exergame research and development in collaboration at the intersection of human movement science, user experience and game design(2026) Ciemer, Celina; Schott, Nadja (Prof. Dr.)Increasing motor and cognitive inactivity presents a growing global health concern. It contributes significantly to chronic diseases, cardiovascular conditions, and cognitive decline, leads to higher mortality rates, and diminishes overall well-being and quality of life. In response, there is an urgent need for effective and motivating motor and cognitive health promotion. Exergames using motor-cognitive exercises embedded within a game context have emerged as a promising approach. However, their potential remains underexploited due to insufficient interdisciplinary collaboration and the lack of transparent, structured design practices, which hinder meaningful evaluation by generalization. In this thesis, the Co-creative Interdisciplinary Exergame design process Model and Extended Reflection (CIEMER) framework is introduced and developed to address these foundational challenges. CIEMER consists of a conceptual model that fosters shared understanding through defined relational structures, a practical design process that produces clear, interpretable outcomes, and applicable collaboration methods. This framework redefines interdisciplinary collaboration as an active relational process requiring dedicated structure. By integrating different epistemological concepts and procedures in a pluralistic approach and translating this disciplinary expertise into a shared language, CIEMER facilitates shared design and evaluation. It enables the visibility of both discipline-specific concepts and procedures as well as their translation into interdisciplinary design decisions within a shared context. CIEMER further supports the precise definition of shared exergame objectives and corresponding evaluation strategies, thereby enabling comprehensible, comparable, and reproducible insights beyond 'black-box' findings. CIEMER thus provides a foundational step toward standardizing interdisciplinary exergame design and reporting practices. The framework has been validated by designing two high-fidelity and four early-stage exergames. Both high-fidelity exergames are designed to address functional decline across motor, cognitive, sensory, and psychological domains through multidimensional training. They incorporate natural, unrestricted walking as it is a fundamental mode of human mobility. This type of walking requires the continuous integration of locomotion, postural control, and adaptation to environmental demands, forming a complex dual-task scenario that is central to real-world functioning. The first exergame is based on the clinical Trail-Walking Test and translates its dual-task structure into an urban scenario using mixed reality floor projection mapping. The second exergame integrates various unrestricted natural walking patterns within a hiking environment that reflects real-world conditions. It is implemented in fully immersive virtual reality and specifically targets fall prevention in healthy, community-dwelling older adults. This is achieved through the integration of effectiveness, enjoyment, and meaningfulness objectives of human movement science, game design, and user experience design, and supported by the results of a quasi-randomized controlled trial. Additionally, a cross-disciplinary systematic review identified key research gaps and challenges in fall prevention exergame collaborations. A novel systematic literature search framework (CRIS) was developed to enable such reviews, accommodating the highly variable nature of exergames across forms of collaboration, applications, and disciplines, addressing epistemological differences. This thesis marks a starting point for structured interdisciplinary collaboration in exergame research. This work can help future work to expand the proposed reporting practices, apply and refine the process in varied interdisciplinary and contextual settings, and further develop context-specific methods to establish robust, generalizable standards.Item Open Access A model-based framework for the assessment of energy-efficiency and CO2-mitigation measures in multi-cylinder paper drying(Stuttgart : Universität Stuttgart, Institut für Energiewirtschaft und Rationelle Energieanwendung, 2022) Godin, Hélène; Radgen, Peter (Prof. Dr.-Ing.)Thesis on the effect of energy-efficiency and CO2-mitigation measures in multi-cylinder paper drying.Item Open Access Data-driven modelling of neuromechanical adaptation in skeletal muscles in response to isometric exercise(Stuttgart : Institute for Modelling and Simulation of Biomechanical Systems, Chair of Continuum Biomechanics and Mechanobiology, University of Stuttgart, 2022) Altan, Neriman Ekin; Röhrle, Oliver (Prof., PhD)This study aims to model the changes in the behaviour of motor neurons of the vastus lateralis in response to unilateral isometric knee extension exercise (UIKEE). For this, the phenomenological motor control model by Fuglevand et al. (1993) has been used. Input parameters for this model have been calibrated against data from experimental studies available in literature by using Bayesian updating. The pre-exercise state of the motor neuron pool of the muscle describing the recruitment behaviour as well as the contractile properties of the motor neurons have been constructed. Data collected from a systematic review on the change in isometric strength due to UIKEE has been modelled using Bayesian lonigutidinal model-based meta-analysis. Using the model of the change in isometric strength, increase in the average motor neuron discharge rate following UIKEE has been quantified.Item Open Access Untersuchung einer Augmented Reality Kollaborationssoftware in der verteilten agilen Arbeitsweise der Automobilentwicklung(2024) Dyhringer, Robert; Resch, Michael (Prof. Dr.-Ing. Dr. h.c. Dr. h.c. Prof. e.h)Der Begriff Metaverse motiviert seit 2021 neue Forschung in der Wissenschaft, insbesondere in der Automobilentwicklung. Die Kombination von agilen Arbeitsweisen und verteilter Zusammenarbeit wirft neue Herausforderungen auf, die durch den Einsatz einer kollaborativen Augmented Reality Software bewältigt werden können. Eine methodisch entwickelte Software und wissenschaftliche Studien zeigen in dieser Arbeit, dass die Technologie der Augmented Reality die gleichberechtigte Gruppenarbeit und die Kommunikation in einem agilen Setup verbessern kann.Item Open Access Urban health games. Collaborative, expressive & reflective(2012) Knöll, Martin; De Bruyn, Gerd (Prof. Dr. phil.)In order to promote healthy lifestyles and wellbeing, many public health experts call for innovative and transdisciplinary research approaches. They welcome contributions from a great variety of professions including nutritional and environmental sciences, epidemiology, medicine, geography, sports sciences and urban planning. Meanwhile, designers are investigating the ways in which new layouts for lunch rooms may better inform people about healthier food choices. Architects and urban planners are stressing pedestrian-friendly street networks and buildings to such an extent that they discreetly hide away elevators to encourage people climbing the stairs. With this dissertation, I would like to draw attention to digital health games as a participatory, location sensitive and playful approach to promote healthy behaviours, which so far has been little addressed by urban research. Health games aim to be entertaining, but also seek to engage players into learning or physical exercise. One of their commercially most successful products to date - Nintendo's Wii Sports series - may be played foremost in peoples' homes. However, health games run increasingly on mobile devices and begin to interact with their topographic, cultural and social context. The iPhone game Monumental for instance invites players to climb iconic monuments such as Eiffel Tower or Empire State Building. At the same time, the game is tracking players' movement through the iPhone's on-board accelerometer. Their designers hope to engage participants by beating personal high scores and by competing with their friends via Facebook or other social networking sites. Several mobile games likewise have explored the potentials of social influence for health promotion. Notably, they have highlighted architectural theory as a major source of inspiration claiming to learn from cities and buildings how to stimulate social interaction and support. With this dissertation, I would like to invite further consideration on how architectural and urban research can contribute to the design and analysis of digital health games. Beyond providing health-related expertise on specific buildings, places and topographies, I will demonstrate how architectural and urban theory reveals a profound source to discuss aspects of user participation, social interaction and can help to create a wider range of gameplay experiences. In turn, I will demonstrate how what I define as urban health games may unfold particular potentials as a design tool that enables users to discuss and indicate health-orientated urban interventions. I will therefore investigate architectural and urban design theory with a focus on spatial strategies to support health-related behaviour. Seeking to involve users into design processes as much as possible, I will pay particular attention to the theoretical concepts of so-called "organic" architects from the first half of 20th century. The latter have criticised precisely those colleagues, who we may consider as functionalist and indeed health-orientated. Hugo Häring for instance criticised Le Corbusier for imposing idealistic, over-rational and pre-fixed designs onto peoples' daily routines. In contrast, he claimed for users to articulate design briefs and wanted architects to develop open-ended design processes. I will follow the notion of temporary, personally tailored architecture to post-war planners such as Archigram and Yona Friedman. Building upon these concepts, I will demonstrate how today's mobile technologies can contribute to the advantages of making users aware of environmental influences on one's health and wellbeing. To this end I will investigate how the notion of serious games has developed as a temporary experience that connects mobile technology, body data and different real world locations. Whereas traditional sports have highlighted self-improvement and foremost competitive forms of play, I will show how health games will have to explore a wider range of play activities to appeal to their audience. Investigating game design theory and relating it to relevant urban projects, I will highlight more creative forms of playing digital health games in the city. Understanding urbanity as state of increased social and cultural exchange and reflecting on attempts for re-appropriating urban space through spatial practices, I will illustrate what may render mobile and location sensitive health games as distinctively urban. I will conclude this investigation by presenting three ways of playing health games in the city as collaborative, expressive and reflective. This framework will be based on an analysis of how current examples of health games benefit from and contribute to their social and built environment.Item Open Access Housing adjustment to handle natural hazards : proactive urban development planning for an effective response to natural hazards and to "build back better" in recovery, rehabilitation, and reconstruction - on the case of Banda Aceh, Indonesia(2021) Lucas, Sabrina; Schönwandt, Walter L. (Prof. Dr.-Ing. Dipl.-Ing. Dipl.-Psych.)Natural hazards, including climatological, meteorological, hydrological, and geophysical hazards can have a devastating impact on human life, the built environment, urban development, and economy. A lack of money and resources, inadequate planning laws and regulations as well as a lack of effective monitoring strategies, are reasons why people in developing countries are particularly vulnerable to the impact of natural hazards. In many cases, there is a lack of information and knowledge about what can be done to appropriately adjust housing, comprising the immediate physical environment, both within and outside of buildings where people live, and which serve as a shelter from external influences. The present thesis investigates the need for pre-disaster housing adjustment strategies as a necessary contribution of urban development planning at a local level. This was achieved through systematic interviews and field studies in the post disaster study area Banda Aceh, Indonesia. Two instruments for pre-disaster planning are introduced: ‘Proactive urban development planning as pre-disaster protection’, a systematic risk management approach, before a disaster strikes as part of the everyday planning process; and a ‘reconstruction template’ to prepare for the worst-case scenario. With these two instruments, not only the quality of reconstruction projects can be improved but, in long-term urban development planning, housing can be adjusted to natural hazards. This approach is based on the UNISDR (United Nations International Strategy for Disaster Risk Reduction) Sendai framework for Disaster Risk Reduction 2015-2030 and forms a bridge between post-disaster reconstruction and long-lasting urban development.Item Open Access Contact Networks of Mobile Agents and Spreading Dynamics(2006) González, Marta C.; Herrmann, Hans J. (Prof. Dr.)The concept complex networks'' refers to a network that is often the representation of a complex system. In this context, a statistical physics approach has been exploited as a very convenient method because of its deep connection with graph theory and because of its ability to quantitatively characterize macroscopic phenomena in terms of the microscopic dynamics of the various systems. Our research focuses on the development of appropriate models of spreading dynamics, such as diffusion models of opinion formation and spreading of infections. Particularly, we present models of contact that differ from the traditional static graph modeling that is at the core of classical graph theory: We incorporate underlying agent interactions that generate dynamical contact networks. The network itself is the result of the interactions among nodes. Motivated by the close relations of the field with real world measurements, we collect and incorporate in the context of Statistical Physics literature new sets of social networks in order to test and validate the models here proposed.Item Open Access Miscibility, viscoelastic reinforcement, and transport properties of blend membranes based on sulfonated poly(phenylene sulfone)s(2021) Saatkamp, Torben; Maier, Joachim (Prof. Dr.)Chemical energy that hydrogen may generate during combustion and the corresponding electrical energy are interconvertible by means of a fuel cell (FC) and by the electrolysis of water (WE), which allows for the utilization of the complementary nature of these two key energy vectors towards energy sustainability. A proton exchange membrane (PEM) made from an ionomer is commonly employed as the electrolyte in mobile fuel cell applications and in water electrolyzers that require dynamic operability and pressurized product gases. New PEM materials are needed to increase performance, reduce environmental impact, and allow for a more targeted design of PEMFC and PEMWE systems, all of which is in some way limited by the use of the established perfluorosulfonic acid (PFSA) type ionomers. This work’s focus lies on sulfonated poly(phenylene sulfone)s (sPPS), a unique group of fluorine-free cation conducting ionomers. They are unique in terms of their chemical stability and transport properties, however, typical in terms of their salt-like brittleness in the dry state and extensive swelling at high humidity and in water. To make the unique properties of sPPS available in application, the goal of this work is to take a comprehensive approach to their viscoelastic reinforcement. Therefore, the structure of this thesis entails three related aspects along the process from pure materials to the optimization of robust PEMs for application. The first chapter focuses on the optimization of the intrinsic viscoelastic properties of a particularly suited sPPS (termed S360, with IEC 2.78 meq g-1, EW 360 g mol-1) which lays the groundwork for reliable and systematic further development. To achieve this, relevant properties of S360 are first characterized and viscoelastic shortcomings as seen in water uptake measurements and tensile tests under dry conditions (≤ 30% relative humidity, RH) discussed. The step-growth polymerization of S360 is optimized after finding significant inorganic contamination retained in the established purification process of the widely used monomer sulfonated difluorodiphenyl sulfone (sDFDPS), allowing for the preparation of the ionomer in reproducible high molecular weight. Relevant properties of high molecular weight S360 are characterized and an enhancement of mechanical properties at 30% RH as well as when submerged in water is found. Access to reproducible high quality of S360 enables its first-time use and study as a PEM in a completely fluorine-free WE cell. At 80 °C, record performance amongst fluorine free electrolytes in PEMWEs of 3.48 A cm-2 at 1.8 V is achieved, showcasing the potential of sPPS for application. The second chapter entails the identification and better understanding of a suitable and versatile reinforcement concept for creating robust membranes based on sPPS. To achieve this, the established homogeneously miscible acid-base polymer blends of sulfonated ionomers with poly(benzimidazole) (PBI, and its derivatives PBIO and PBIOO) are discussed in-depth and chosen for later systematic optimization in combination with sPPS. Since the origin of miscibility in PBI blends with sulfonated ionomers is insufficiently described in literature and could facilitate targeted design of new blend components, a model acid-base polymer blend system comprising pyridine-functionalized poly(sulfone) (PSU) is created. Pyridine groups of different basicity tethered to PSU in varying concentration are used to investigate the effect that interpolymer acid-base interaction strength and concentration have on miscibility in blends with 80 wt% S360, as derived from the blend membranes’ cross-sectional SEMs. High mutual compatibility is achieved at high concentration of weak interpolymer interaction, which is interpreted with regards to the observed miscibility in PBI blends. Based on the derived role that hydrogen bonds may play in PBI blends, the difference of interpolymer interaction in solution (during membrane formation) and in the dry membrane is described. This could enable the development of new blend concepts in the future. An exemplary miscible blend that comprises interpolymer hydrogen bonds only in solution but not in the final membrane is shown. The third chapter describes the optimization and balance of properties in the previously described polymer blends with PBIO, following the goal to prepare membranes which can be evaluated in fuel cells and fabricated on a wider scale in order to bring the attractive properties of sPPS into application. To achieve this, S360-blend membranes of varying PBIO content are characterized with regard to conductivity and mechanical properties in various conditions. High mechanical robustness is achieved in S360 blends with 30 wt% PBIO but is accompanied by dramatic reduction of conductivity, due to the charge-consuming acid-base interaction. The findings are translated into blends with fully sulfonated sPPS (termed S220, with IEC 4.54 meq g-1, EW 220 g mol-1) which allows for the creation of membranes that combine mechanical toughness with high conductivity at a ratio of 25 wt% PBIO in S220, making the material suited for production on a commercial casting line and fuel cell testing. Membranes based on S360 that comprise 15 wt% PBIO are designated for further studies in PEMWEs, where membrane requirements differ significantly from that in PEMFCs, highlighting the versatility of the reinforcement approach chosen in this work. Finally, first fuel cell tests of thin spray coated PBIO blend membranes are conducted, and initial durability testing of sPPS-based membranes in fuel cells is possible. Overall, the results presented in this work are strongly interrelated which underlines the importance of comprehensiveness in the successful viscoelastic reinforcement of sulfonated poly(phenylene sulfone)s. Ultimately, the blend membranes resulting from this work can be used as a platform for further development of sPPS-based PEMs in the future.Item Open Access 3D CFD Simulation von Turboladern innerhalb einer Motorumgebung(2014) Boose, Benjamin; Bargende, Michael (Prof. Dr.)Im Rahmen dieser Forschungsarbeit wird das Verhalten mehrflutiger Abgasturbolader innerhalb einer Motorumgebung mit pulsierenden Randbedingungen in verschiedenen Motorbetriebspunkten mittels eines CFD Ansatzes untersucht. Dazu wird ein vollständiges dreidimensionales Strömungsmodell eines asymmetrischen Zwillingsstromturboladers aufgebaut, beginnend bei den Abgaskrümmern über die Turbinen- und Verdichtergehäuse inklusive der kompletten Laufräder bis hin zum Vorkatalysator. Die Eintrittsrandbedingungen für die Abgaskrümmer bestehend aus zeitabhängigem Massenfluss und Temperatur für zwei Motorbetriebspunkte bei hoher und niedriger Drehzahl werden von einem eindimensionalen Strömungsmodell des gesamten Motors generiert. Die Turbinen- und Verdichterseite des Modells sind durch ein Momentengleichgewicht gekoppelt und die aktuelle Turboladerdrehzahl wird für jeden Zeitschritt berechnet. Aus diesem Grund werden für die Analyse des Turboladers weder Turbinen- noch Verdichterkennfelder benötigt. Um die Rotation der Laufräder zu modellieren, wird ein Ansatz mit explizit bewegten Gittern verwendet und die Laufradgitter werden vor jedem Zeitschritt mittels eines Gitterinterfaces an die stationären Gehäuse gekoppelt. Als Ergebnisse des Modells werden verschiedene zeitaufgelöste physikalische Größen sowie Wellenleistung und Laderdrehzahl ausgewiesen. Auf Grund der pulsierenden Druckrandbedingung ist es ebenfalls möglich, die instationären Effekte wie Befüllen und Entleeren der Turbine zu untersuchen. Darüberhinaus ist das Modell dieser Forschungsarbeit in der Lage sowohl den instationären Wirkungsgrad unter Druckpulsationen als auch die Überströmverluste, welche durch die unterschiedlichen Druckniveaus der Fluten bei pulsierender Beaufschlagung entstehen, zu analysieren. Um diese Verluste zu quantifizieren, werden neue Kennzahlen eingeführt. Auf Basis der asymmetrischen Zwillingsstromturbine wird eine Doppelstromturbine und eine symmetrische Zwillingsstromturbine mit dem selben Volumen konstruiert. Es werden identische Randbedingungen und die gleichen Laufräder für die Analyse der beiden neuen Varianten verwendet. Diese Turbinenlayouts werden mit dem Ausgangsmodell bezüglich Laderdrehzahl, Wellenleistung und instationärem Wirkungsgrad verglichen. Mit Hilfe neu eingeführter Kennzahlen ist ein Vergleich der Überströmverluste innerhalb der Turbine und des daraus folgenden Rückströmens in den Abgaskrümmer möglich. Das Rückströmen führt zu einem erhöhten Abgasgegendruck und beeinflusst den Ladungswechsel des Zylinders.Item Open Access Entwicklung eines Modells zur Ermittlung psychischer Beanspruchung am Beispiel von Reisenden bei geschäftlich bedingten Hotelaufenthalten(Stuttgart : Fraunhofer Verlag, 2018) Borkmann, Vanessa; Spath, Dieter (Univ. Prof. Dr.-Ing. Dr.-Ing. E.h. Dr. h.c.)Die wissenschaftliche Arbeit untersucht belastende und erholungsförderliche Einflussfaktoren und deren Wirkungen während des Hotelaufenthalts auf die psychische Beanspruchung des geschäftlich Reisenden. Die arbeitswissenschaftliche Untersuchung stützt sich dabei auf einen multidisziplinären Forschungsansatz, der komplexe Zusammenhänge und selektierte Erkenntnisse über die klassischen Grenzen hinweg inhaltlich verknüpft.