13 Zentrale Universitätseinrichtungen
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/14
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Item Open Access Exploring how personality affects perception of uncertainty visualization(2025) Aboulgadayel, OmarInterpreting uncertainty visualizations can be cognitively demanding, and individual differences, such as personality traits, may affect how people perceive such visualizations. While prior research has explored personality and cognitive load independently, few studies have investigated their combined influence on perception and decision-making in uncertainty visualizations. We conducted an experiment based on a wildfire evacuation task that compared textual and visual representations of uncertainty. Participants completed the NASA Task Load Index to assess perceived cognitive workload and a Big Five personality traits test to measure individual differences in personality. Consistent with prior findings, visual representations led to higher evacuation rates and faster decision times compared to textual representations. However, textual representations were associated with lower perceived cognitive workload. Personality traits significantly impacted decision-making behavior and perceived cognitive workload. Participants high in extraversion, neuroticism or openness were more likely to evacuate, while those high in agreeableness or conscientiousness were less likely to evacuate and tended to take more time to decide. Additionally, agreeableness and conscientiousness were positively correlated with perceived cognitive workload across all representations, whereas neuroticism and openness showed negative correlations, though only in certain representations. These findings offer new insights into how personality affects the perception and cognitive load in the context of uncertainty visualizations.Item Open Access Accelerated 2D visualization using adaptive resolution scaling and temporal reconstruction(2023) Becher, Michael; Heinemann, Moritz; Marmann, Thomas; Reina, Guido; Weiskopf, Daniel; Ertl, ThomasData visualization relies on efficient rendering to allow users to interactively explore and understand their data. However, achieving interactive frame rates is often challenging, especially for high-resolution displays or large datasets. In computer graphics, several methods temporally reconstruct full-resolution images from multiple consecutive lower-resolution frames. Besides providing temporal image stability, they amortize the rendering costs over multiple frames and thus improve the minimum frame rate. We present a method that adopts this idea to accelerate 2D information visualization, without requiring any changes to the rendering itself. By exploiting properties of orthographic projection, our method significantly improves rendering performance while minimizing the loss of image quality during camera manipulation. For static scenes, it quickly converges to the full-resolution image. We discuss the characteristics and different modes of our method concerning rendering performance and image quality and the corresponding trade-offs. To improve ease of use, we provide automatic resolution scaling in our method to adapt to user-defined target frame rate. Finally, we present extensive rendering benchmarks to examine real-world performance for examples of parallel coordinates and scatterplot matrix visualizations, and discuss appropriate application scenarios and contraindications for usage.Item Open Access Online visualization of German power plants and their production(2017) Ullah, Kazi RiazMaps are used for centuries to visualize geographical or topological information and nowadays, with modern technology, we can create interactive maps that allow us to display and access additional information. Some of them have even become part of our daily life, such as, almost real-time traffic information. Furthermore, maps are often used to display data of population densities, temperatures and spatial distribution of geographical phenomenon. Fraunhofer Institute of Solar Energy ISE decided to build an interactive map that shows the locations of all power plants listed on the European Energy Exchange (EEX). Since July 2014, the Fraunhofer ISE has been providing interactive charts on electricity production and other related information about electricity and power generation in Germany. These charts became very popular and widely used by people from different professions, namely scientists, politicians, journalists as well as online/printed media. Due to the high popularity of these interactive energy charts, an interactive map has been added to the Energy Charts data visualization portal to make the framework more informative and interesting for users. The map has several search options and levels of detail for searching different power plant locations, technical data, and connectivity to the high voltage transmission lines. Furthermore, this new visualization framework is interconnected with the existing energy charts. The dynamic linking, brushing and filtering technique in both map and energy charts have enhanced the framework by an additional layer providing more visibility and information on the selected power plants.Item Open Access AR driving assistant for wheelchairs(2024) Halach, TimWheelchairs are an important mobility aid for many people, but our built environment presents them with many challenges. To help those people better navigate our cities, we explore the viability of an informational driving assistant for wheelchairs. Driving assistants have already become commonplace in cars to help drivers control their cars. In this thesis, we present a prototype of a driving assistant for wheelchairs and evaluate it in a user study. To find what information the driving assistant should show to its users, we performed a requirements analysis on what information wheelchair and other mobility aid users might need from such a system and based our prototype on those findings. The results of our user study are inconclusive, because we had too few participants, but the concept itself seems promising.Item Open Access A VR-based training system for an ankle surgery(2022) Nguyen, Duc AnhThe supramalleolar osteotomy is a surgery, which aims to correct ankle osteoarthritis. Surgeons specializing in osteotomies regularly need to make accurate and precise cuts to a patient's bone with tools like an oscillating bone saw. In order to acquire the knowledge and skills to perform the real ankle surgery, they need to watch tutorials and practice on physical test models beforehand. In this work, we create a training system for the supramalleolar osteotomy in virtual reality. This includes the implementation of a bone cutting simulation and a post-analysis tool to evaluate the performance. A simple cut for this type of surgery requires the knowledge of its starting point, orientation, and current coverage. Furthermore, we design different concepts for visualizations, which aim to provide guidance, assistance, and feedback to the trainee surgeon during the operation. A preliminary study with a medical expert investigates the performance regarding the cut accuracy of each design. The study showed that the overall usage of those designed guidance visualizations improved the user's confidence during the operation. One key observation was that visualization directly positioned onto the cutting region performed better than the ones which were further away.Item Open Access Evaluating different combinations of haptic feedback devices in Virtual Reality(2023) Gebhardt, PatrickVR-based systems have been using more and more haptic feedback devices for enhancing immersion and interaction, not only in the consumer market but also in industrial applications. However, different combinations of haptic feedback devices could result in different user experiences. To evaluate different types of multimodal haptic feedback, an exemplary use case was built in which combinations of STRIVE, STROE, and SenseGlove can be used. Since the use case was developed close to typical virtual buildability working patterns in the automotive industry, only VR experts from the respective departments were invited to participate in the subsequent user study, designed to evaluate the different combinations of haptic feedback devices. Participant feedback was recorded using a haptic questionnaire and an interview to obtain a broad spectrum of feedback that provides essential information for development in the future. Feedback from participants shows that currently, a combination of collision simulation and weight force simulation by the STRIVE and STROE devices leaves the best impression. Other important findings show that haptic feedback is generally very well accepted, but that full haptic feedback is not always required, since not all haptic impressions are necessary for every work step. Thus, while haptic grasping is beneficial in some of the tasks, it cannot keep up with the simplicity of the controller due to imperfect precision, among other things. A promising prospect for the future is therefore the implementation of finger tracking in combination with collision feedback and weight simulation as a middle ground between haptic grasping and the use of a controller since the haptic feedback of STRIVEs and STROE could thus be applied directly to the user’s hand.Item Open Access Visual parameters space analysis for architectural design space exploration(2023) Grund, SebastianArchitects, in their search for building designs, are offered multiple supportive tools by various CAD Software. One such tool is multi-objective optimization (MOO) where a computer proposes possible designs that try to optimize multiple performance functions. But in the past, it was disclosed that the results of such Optimization runs can be hard to interpret and work with correctly. Together with experienced field experts, we analyzed the problem and derived the necessary design requirements for a possible supportive interface. Working closely with these experts we then developed an interactive visualization prototype that aims to help architects with their MOO design approach. To support the exploration of the multi-dimensional parameter space and the multi-dimensional objective space the presented prototype utilizes multiple coordinated views. The Views include among others a parallel coordinates plot of the data points for correlation detection and two scatter plots displaying each only the dimensional reduced parameter and objective part of the MOO results. Together with automated and manual clustering as well as other interaction capabilities, the tool supports exploration and filtration steps for the MOO design process. Next to the direct feedback of the field experts during the iterative development stages, we also evaluated the prototype in a hands-on expert review where MOO results for two different Models were analyzed. The chosen coding style tries to lower required expenses for the addition of more views should additional requirements or different visualization approaches occur. Our tool aims to be integrated into an existing MOO tool (opossum for Rhino3D) and become the interlinking part between the computer and the architect in their cooperative building design search.Item Open Access Affective Sonification(2023) Caycedo, NicolasDie Definition von Gefühle ist immer noch ein heftig diskutiertes Thema, zu dem neue Herausfindungen ständig ans Licht gebracht werden. Externe Reize spielen oft eine wichtige Role in unseren Gefühlen und können unsere Stimmung schwanken in noch nicht ganz verstandenen Arten. Gefühle und Affekt haben auch auf unsere kognitive Leistung und Interpretation von anderen Reizen einen Einfluss. Umfangreichende Forschung über die Einwirkung der Musik und Klänge auf Emotion ist ausgeführt gewesen. Im Bereich der Sonifikation sind Daten oft abstrakt durch nicht sofort erkannbare Klänge dargestellt. Wir versuchen eine Benutzerstudie und die dazu gehörige Werkzeuge zu entwürfen, mit der man besser verstehen kann, wie der Gehöraspek einer audiovisuelle Datendarstellung den Enmpfänger beeinflusst. Im Lauf des Projekts entwickeln wir eine Softwareapplikation, die Elemente des partizipativen Designs einbindet, um Laien bei der Erstellung eines Daten representierenden Schalles zu helfen. Wir führen eine Pilotstudie und legen den Grundstein einer vollwertigen zukünftigen Benutzerstudie. Dieses Dokument beschreibt unser Entwurfprozess, Herausforderungen, und Überlegungen durch die Plannung der Benutzerstudie und dazu gehörige Software.Item Open Access Ein volumetrischer Imposter zur Level-of-Detail-Darstellung von Partikeldatensätzen(2017) Rau, BenjaminComputersimulationen, welche auf Grundlage von Partikeldaten arbeiten, finden nicht nur immer häufiger Anwendung als wissenschaftliche Hilfsmittel, sondern nehmen auch stetig an Komplexität zu. Die daraus resultierenden Daten werden zur Analyse oftmals visualisiert. Dabei stellen die großen Datenmengen die Visualisierung vor mehrere Herausforderungen. Einerseits benötigen die Daten enorm viel Speicherplatz, was eine direkte Visualisierung oftmals unmöglich macht. Weiterhin kommt es bei der direkten Darstellung der Partikel zu Problemen des Undersamplings und damit verbundenem Bildrauschen. Diese Arbeit untersucht einen möglichen Ansatz, diese beiden Probleme zu umgehen. Dabei werden Partikeldaten in Volumen aggregiert, welche die Normalenverteilungsfunktion dieser Partikel approximiert. Dies erlaubt es zum einen, Speicherplatz einzusparen, indem die aggregierten Partikel nicht mehr im Speicher gehalten werden müssen. Zum anderen ermöglicht es diese Technik, die Daten Offline, mit einer sehr hohen Auflösung, abzutasten und diese hochaufgelöste Abtastung beim interaktiven Rendering zu verwenden, um Bildrauschen zu minimieren.Item Open Access Designing the next smart chair based on a posture recognition and feedback literature review(2022) Krauter, ChristianSitting is considered unhealthy, and there is an ongoing trend towards more and longer time spent seated, with no foreseeable end to this development. Research indicates that we should take frequent breaks from sitting and not sit in the same posture for extended periods. Our smart gadgets can already suggest breaks, but for more nuanced feedback about how we sit, special hardware and software are needed, two topics on which much research has already been done. Our contribution to this research is two-fold: First, we conducted a literature review of hardware used to recognize sitting posture and of feedback to help the users be aware of how they sit and suggest ways to do so healthier. Second, we built a smart chair prototype that uses various sensors to measure how the user sits and then provides visual feedback about that. Our literature review shows that recognizing sitting behavior and giving feedback about it can be solved in different ways. Our aim was to give a broad overview of the research area while putting additional focus on pressure-sensing hardware and visual feedback. Based on this, we propose to consider the following factors when selecting techniques: the environment, cost, privacy concerns, portability, and accuracy. Furthermore, the user’s capabilities and preferences should be taken into account. We also found a need for additional and more comprehensive user studies that examine the effects of different types of visual feedback. Our smart chair prototype is equipped with four pressure sensors in the seat and three distance-measuring sensors in the backrest. We consider our prototype to be an initial starting point for further work that aims to extend our approach. One possible extension would be to add a sitting posture classification algorithm. Other feedback variants could also be added and evaluated through user studies to gain more knowledge about different methods and their effects on sitting behavior. Furthermore, we suggest future work to expand upon our literature review to get a broader understanding of sitting posture recognition and feedback.