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 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 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 Augmented visualization guidance for wire placement in timber fabrication(2021) Zhu, MarcoAugmented reality has become a broad area over time, which opens up many opportunities, also for industry. Nevertheless, digital solutions have not yet been used for some industrial applications. We focus on the use case “wire placement in timber fabrication”. The task here is to place and fix a cable along a certain route on a timber panel. However, there are several important factors and risks to consider that could cause the task to fail. Usability and efficiency play an essential role in optimally supporting use cases like this. Furthermore, we hope to make the task of this special industrial use case easier for workers by using augmented reality. For such an optimization, the design of a suitable visualization as part of the augmented reality system is indispensable. We constructed possible virtual representations for this use case and developed different suitable prototypes. Based on a user study, we compared the visualizations of these prototypes, evaluated their efficiency and user experience by measuring the workload, usability, task completion time, and determining error rates. By analyzing the developed visualization prototypes, a certain prototype proved to be optimal. With this, the route of the cable is shown as a path on the timber plate and displayed in color. The efficiency differences between this prototype and the other prototypes, supported by augmented reality, are not severe. The use of the augmented reality system turned out to be an essential enrichment. Compared to an equivalent system that is not supported by augmented reality, the developed augmented reality systems showed clear advantages. The suitability of this prototype has been checked and proven through a dry run. The task of the use case could be carried out successfully while the important factors and risks were also considered. The final fabrication has yet to be carried out.Item Open Access Bias in scatterplots(2025) Krestic, AmelPrior beliefs of viewers are a significant factor of bias when working with visualizations. This belief bias can easily be evoked by axis labels and context, leading to an influence on a viewers interaction with and analysis of said visualization. Even for low level visual analytic tasks, viewer beliefs show themselves as an influence, where one would otherwise hope viewers would be entirely objective. Through a user study, I show how belief triggering axis labels can influence a viewer’s correlation estimates of scatter plots when compared to the same plots with neutral X/Y labels. Viewers first reported their beliefs in six variable pairs that are used as labels later. The viewer’s baseline correlation estimates of plots with X/Y labels were gathered, and compared to the estimates of the same plots, but with belief triggering labels (i.e. Income/Happiness). When viewers believed in the relation of the variables, they increased their correlation estimates. Meanwhile when they believed them not to be related, they decreased their estimates. Further more, this effect extends to the viewer’s gaze behavior. Viewers with different belief strengths showed different levels of fixation on outliers, increasing or decreasing from their baseline dependent on belief strength. They also generally showed different shifts in attention distribution across the plots. The results reaffirm the possible effect of belief on even low level analytic tasks, and suggest an effect on viewer perception akin to selective attention or increased salience of features that align with existing belief. These findings can aid researchers working on visualizations techniques and dynamic visualization systems that aim to recognize and mitigate such cognitive biases.Item Open Access Using an electric guitar as an input device for tab interface navigation(2025) Labudda, MariusGuitar tablature is a musical notation that uses six lines to represent the strings, while numbers on those lines show which frets to press. Digital tablature interfaces enhance the playing and learning experience through synchronized tablature playback, drum tracks, and more. Tablature interfaces are generally operated by touch or conventional mouse and keyboard input. Controlling playback, navigating through songs, and configuring the interface can result in inconvenient context switches since guitarists regularly switch between playing the guitar and interacting with the interface via mouse and keyboard. In this thesis, we use the audio input of an unmodified electric guitar to investigate possibilities for navigating tablature interfaces while avoiding such context switches. Our goal is to facilitate the use of tablature interfaces while maintaining a consistent interaction mode. To achieve this goal, we explored different algorithms to determine which approach works best for our use case of audio-matching tasks. These algorithms compare the guitarist's audio input with synthetically generated song audio and produce a compliance score, which aims to enable navigation for any opened song in the tablature interface. Furthermore, we utilize audio matching to achieve accessible song selection without using a mouse or keyboard. The implementation of bar-specific navigation within a song posed several challenges. First, the recorded audio input differs too much from the synthetically generated sound to enable reliable matching. Second, modern songs have too many bars in which the guitar notes differ little or not at all. These factors and others made it impossible to use a robust audio-based navigation system for jumping to specific bars. However, a bookmark system enables song selection without letting go of the guitar, and predefined commands allow control of many functions. That way, the user can interact with the system without using a mouse or keyboard, relying exclusively on the guitar as the input device. This thesis highlights the opportunities and challenges of integrating audio-based controls into tablature interfaces. It might inspire future work to explore more intuitive ways for musicians to interact with digital systems.Item Open Access Augmenting sports storytelling for people with visual impairments(2025) Koch, PhillipSports storytelling combines data, visuals, and narratives to create an emotional connection with fans. Likewise, people with visual impairments face unique challenges while attending sports events. This thesis proposes a visual approach to assistive technologies, aiming to assist sports spectators with visual impairment to face these challenges. To understand these needs and challenges, I conducted interviews with two football fans who are visually impaired. The findings of the interviews revealed the need for general visual cues to facilitate simple tasks and emphasise detailed information. From these findings, I developed a set of visual cues to highlight main aspects of football matches, including cues for the ball, players, and more general tools like a magnifying glass. The cues were tested in a football scenario during a co-design user study with three sports fans who are visually impaired. The results of the user study suggest that visual cues show promising results in aiding people with visual impairments in the role of sports spectators. This thesis highlights the distinct effectiveness of general cues, situation-dependent cues, detailed cues, and the importance of customisation of these cues. This contributes to the scope of accessible research and reader-driven narrative during sports events.Item Open Access Compressed streaming of sparse images(2025) Heger, FrankaVirtual reality applications can use Multiplane Images (MPIs) to render their virtual scenes. Scenes rendered like this consist of multiple layers, each containing objects visible at its corresponding depth level. Since many depth layers can exist, the amount of data required to transmit even one frame of such a scene can be enormous. This work evaluates the gains in encoding speed and file size achieved by packing only the occupied regions of the layered sparse image into a virtual image and compressing these virtual image sequences using established video codecs such as H.264 and H.265, VP9, and AV1, with both hardware and software implementations, while maintaining decent visual quality. The different encoders are evaluated regarding their encoding speed, file size, and quality. This research suggests that the H.264 FFmpeg software encoder using a tile size of 64 provides the best trade-off among all assessed metrics.Item Open Access Real-time and post-hoc-visualizations of keyboard performances as a support for music education(2020) Bauer, FlorianWir haben einen Prototyp für die Visualisierung von Fehlern beim Üben am Klavier entwickelt. Dieser Prototyp soll Klavieranfängern, die noch kein gut entwickeltes Gehör haben, den Einstieg erleichtern und ihnen helfen, ihre eigenen Fehler besser zu erkennen. In unseren Visualisierungen können Noten in klassischer Notation, in Blocknotation oder als Piano Roll dargestellt werden. Noten in der Blocknotation haben die Form eines Rechtecks mit abgerundeten Ecken und werden anstelle der klassischen Notenköpfe mit einer ihrer Dauer entsprechenden Länge gezeichnet. Der Benutzer kann sein Klavierspiel live visualisieren, speichern und die Aufnahmen später analysieren. Aufnahme- und ground truth Noten werden je nach Notation und Visualisierung nebeneinander oder aufeinander visualisiert. Wir haben einen Algorithmus entwickelt, der aufgezeichnete und ground truth Noten miteinander vergleicht, damit die enthaltene Fehler farbkodierte werden können. Basierend auf der Piano Roll entwarfen wir eine Heatmap-Visualisierung, bei der alle Noten in Zeitscheiben unterteilt werden und diese Scheiben unterschiedliche Farben erhalten, je nachdem, ob die Aufnahme- und die ground truth Note in derselben Zeitscheibe liegen. In unserer Auswertung durch eine Fallstudie kamen wir zu dem Schluss, dass nur die Piano Roll Notation geeignet ist, mehrere Aufnahmen gleichzeitig zu visualisieren. Die Blocknotation eignet sich für die Darstellung des Vergleichs einzelner Aufnahmen. Außerdem ist die klassische Notation in diesem Stadium im Allgemeinen ungeeignet, da in ihr mehrere Noten in einem engen Bereich schnell unübersichtlich werden. Der Fehleranalyse-Algorithmus erfüllt seinen Zweck, wenn das vorgegebene Tempo eingehalten wird. Andernfalls kann es vorkommen, dass Noten falsch zugeordnet werden.Item Open Access Generating 3D hedge mazes from base 2D maps(2025) Gaug, ChristopherHistorical sites, particularly intricate structures like garden mazes, often survive only as two-dimensional maps, leaving their immersive, three-dimensional nature lost to time. This thesis addresses the challenge of digital reconstruction by developing and evaluating a procedural pipeline for generating immersive 3D hedge mazes from 2D vector data for virtual reality (VR) applications. Focusing on the historic Labyrinth of Versailles, this work presents a comprehensive workflow that begins with parsing SVG map data and using it to procedurally generate a network of splines within Unreal Engine 5. These splines then guide the placement of high-fidelity, modular hedge assets. The system leverages modern rendering technologies, including the Nanite virtualized geometry system to handle complex foliage and the Lumen global illumination system for photorealistic lighting. The evaluation demonstrates that the procedural generation pipeline is significantly more efficient and geometrically faithful to the source material than manual creation methods. The final result is a high-performance VR application that successfully reconstructs the historical maze, allowing for natural and immersive exploration. This work serves as a proof-of-concept, showcasing how procedural techniques combined with advanced real-time rendering can effectively transform static historical records into engaging, interactive cultural heritage experiences.