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Francesco Vona

Publications and source records attributed to Francesco Vona.

At least 19 recordsLinked to original sources

3D Gaussian Splatting and Mesh-Based Digital Twins: An Exploratory Study for Virtual Reality Tourism

Digital Twins (DTs) are increasingly used for immersive experiences in virtual tourism. Virtual Reality (VR) enables remote visits to replicated locations for promotional purposes or access to fragile and rural cultural heritage sites. However, developing high-fidelity DTs of tourist destinations is costly, due to the manual creation of 3D environments. Novel 3D rendering techniques, such as 3D Gaussian splatting (3DGS), pose a promising approach to creating immersive experiences. This study investigates the user experience (UX) of a 3D-mesh-based scene and a 3DGS-based scene within a VR tourism application. In a laboratory study, 20 participants engaged with both versions and rated UX, cybersickness, presence and affect through standardized questionnaires. A custom questionnaire was created to measure the perception of the DTs. The collected data suggests that both versions were enjoyed and induced positive affect, with the Mesh version receiving good UX ratings. While the 3DGS version scored higher in terms of experienced realism, it showed clear weaknesses in pragmatic quality. Further, the results suggest that the feeling of presence could be enhanced and cybersickness reduced in both versions. Overall, the study contributes to the understanding of UX in VR tourism applications by implementing mesh-based and 3DGS-based DTs and raising important questions about the perception of realism.

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Size Matters: The Impact of Avatar Size on User Experience in Healthcare Applications

The usage of virtual avatars in healthcare applications has become widely popular; however, certain critical aspects, such as social distancing and avatar size, remain insufficiently explored. This research investigates user experience and preferences when interacting with a healthcare application utilizing virtual avatars displayed in different sizes. For our study, we had 23 participants interacting with five different avatars (a human-size avatar followed by four smaller avatars in a randomized order) varying in size, projected on a wall in front of them. The avatars were fully integrated with an artificial intelligence chatbot to make them conversational. Users were asked to rate the usability of the system after interacting with each avatar and complete a survey regarding trust and an additional questionnaire on social presence. The results of this study show that avatar size significantly influences the perceived attractiveness and perspicuity, with the medium-sized avatars receiving the highest ratings. Social presence correlated strongly with stimulation and attractiveness, suggesting that an avatar's visual appeal and interactivity influenced user engagement more than its physical size. Additionally, we observed a tendency for gender-specific differences on some of the UEQ+ scales, with male participants tending to prefer human-sized representations, while female participants slightly favored smaller avatars. These findings highlight the importance of avatar design and representation in optimizing user experience and trust in virtual healthcare environments.

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The Impact of Spatial Misalignment and Time Delay on Collaborative Presence in Augmented Reality

Precise temporal and spatial alignment is critical in collaborative Augmented Reality (AR) where users rely on shared visual information to coordinate actions. System latency and object misalignment can disrupt communication, reduce task efficiency, and negatively impact the overall user experience. While previous research has primarily focused on individual AR interactions, the impact of these inconsistencies on collaboration remains underexplored. This article investigates how user experience and task load are affected by object misalignment and time delay in a shared AR space. To examine these factors, we conducted an experiment with 32 participants, organized into 16 pairs, who collaboratively completed a spatial placement task. Within each condition, both participants alternated roles, taking turns as the leader-providing verbal placement instructions-and the builder-executing the placement. Six conditions were tested, manipulating object alignment (perfectly aligned vs. randomly misaligned) and time delay (0s, 0.1s, 0.4s). The misalignment was applied randomly to each virtual object with a shift of +-20 cm on every axis to create a clear distinction in spatial perception. User experience and task load were assessed to evaluate how these factors influence collaboration and interaction in AR environments. Results showed that spatial misalignment significantly increased perceived workload (NASA-TLX) and lowered user ratings in Pragmatic quality and Attractiveness (UEQ), while time delay had a more limited effect. These findings highlight the critical role of spatial accuracy in maintaining collaboration quality in AR.

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Optimized User Experience for Labeling Systems for Predictive Maintenance Applications

This paper presents the design and implementation of a graphical labeling user interface for a monitoring and predictive maintenance system for trains and rail infrastructure in a rural area of Germany. Aiming to enhance rail transportation's economic viability and operational efficiency, our project utilizes cost-effective wireless monitoring systems that combine affordable sensors and machine learning algorithms. Given that a successful labeling phase is indispensable for training a supervised machine learning system, we emphasize the importance of a user-friendly labeling user interface, which can be optimally integrated into the daily work routines of annotators. The labeling system has been designed based on best practices in usability heuristics and will be validated for usability and user experience through a study, the protocol for which is presented here. The value of this work lies in its potential to reduce maintenance costs and improve service reliability in rail transportation, contributing to the academic literature and offering practical insights for research on effective labeling user interfaces, as well as for the development of labeling systems in the industry. Upon completion of the study, we will share the results, refine the system as necessary, and explore its scalability in other areas of infrastructure maintenance.

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Optimizing Predictive Maintenance: Enhanced AI and Backend Integration

Rail transportation success depends on efficient maintenance to avoid delays and malfunctions, particularly in rural areas with limited resources. We propose a cost-effective wireless monitoring system that integrates sensors and machine learning to address these challenges. We developed a secure data management system, equipping train cars and rail sections with sensors to collect structural and environmental data. This data supports Predictive Maintenance by identifying potential issues before they lead to failures. Implementing this system requires a robust backend infrastructure for secure data transfer, storage, and analysis. Designed collaboratively with stakeholders, including the railroad company and project partners, our system is tailored to meet specific requirements while ensuring data integrity and security. This article discusses the reasoning behind our design choices, including the selection of sensors, data handling protocols, and Machine Learning models. We propose a system architecture for implementing the solution, covering aspects such as network topology and data processing workflows. Our approach aims to enhance the reliability and efficiency of rail transportation through advanced technological integration.

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Avatar Appearance Beyond Pixels -- User Ratings and Avatar Preferences within Health Applications

The appearance of a virtual avatar significantly influences its perceived appropriateness and the user's experience, particularly in healthcare applications. This study analyzed interactions with six avatars of varying characteristics in a patient-reported outcome measures (PROMs) application to investigate correlations between avatar ratings and user preferences. Forty-seven participants completed a healthcare survey involving 30 PROMIS items (Global Health and Physical Function) and then rated the avatars on warmth, competence, attractiveness, and human-likeness, as well as their willingness to share personal data. The results showed that competence was the most critical factor in avatar selection, while human-likeness had minimal impact on health data disclosure. Gender did not significantly affect the ratings, but clothing style played a key role, with male avatars in professional attire rated higher in competence due to gender-stereotypical expectations. In contrast, professional female avatars were rated lower in warmth and attractiveness. These findings underline the importance of thoughtful avatar design in healthcare applications to enhance user experience and engagement.

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Unmanned Aerial Vehicles Control in a Digital Twin: Exploring the Effect of Different Points of View on User Experience in Virtual Reality

Controlling Unmanned Aerial Vehicles (UAVs) is a cognitively demanding task, with accidents often arising from insufficient situational awareness, inadequate training, and poor user experiences. Providing more intuitive and immersive visual feedback, particularly through Digital Twin technologies, offers new opportunities to enhance pilot awareness and overall experience quality. In this study, we investigate how different virtual points of view (POVs) influence user experience and performance during UAV piloting in Virtual Reality (VR), utilizing a digital twin that faithfully replicates the real-world flight environment. We developed a VR application that enables participants to control a physical DJI Mini 4 Pro drone while immersed in a digital twin with four distinct camera perspectives: Baseline View (static external), First-Person View, Chase View, and Third-Person View. Nineteen participants completed a series of ring-based obstacle courses from each perspective. In addition to objective flight data, we collected standardized subjective assessments of user experience, presence, workload, cybersickness, and situational awareness. Quantitative analyses revealed that the First-Person View was associated with significantly higher mental demand and effort, greater trajectory deviation, but smoother control inputs compared to the Third-Person and Chase perspectives. Complementing these findings, preference data indicated that the Third-Person View was most consistently favored, whereas the First-Person View elicited polarized reactions.

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Comparing User Behavior in Real vs. Virtual Supermarket Shelves: An Eye-Tracking Study Using Tobii 3 Pro and Meta Quest Pro

This study compares user behavior between real and virtual supermarket shelves using eye tracking technology to assess behavior in both environments. A sample of 29 participants was randomly assigned to two conditions: a real world supermarket shelf with Tobii eye tracking and a virtual shelf using the Meta Quest Pro eye tracker. In both scenarios, participants were asked to select three packs of cereals belonging to specific categories, healthy or tasty. The aim was to explore whether virtual environments could realistically replicate real world experiences, particularly regarding consumer behavior. By analyzing eye tracking data, the study examined how attention and product selection strategies varied between real and virtual conditions. Results showed that participants' attention differed across product types and shopping environments. Consumers focused more on lower shelves in real settings, especially when looking for healthy products. In VR, attention shifted to eye level shelves, particularly for tasty items, aligning with optimal product placement strategies in supermarkets. Overall, sweet products received less visual attention across both settings.

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Two Explorative Studies on Tangible Augmented Reality for Neurodevelopmental Disorders

Tangible Augmented Reality (TAR) is an interaction paradigm that integrates physical and digital worlds to create immersive, interactive experiences. This paper explores two TAR applications, Holomarket and Along the Oceanic Flow (ATOF), and presents insights from two exploratory studies evaluating their usability and likeability among individuals with neurodevelopmental disorders (NDD). Holomarket is designed to simulate a supermarket shopping experience, helping users develop essential life skills such as item selection, basic arithmetic, and money handling. Participants interacted with augmented food items and a smart cash register, navigating a virtual supermarket environment. While participants enjoyed the realistic setting and tangible interactions, some usability challenges, such as difficulty manipulating virtual objects and discomfort with prolonged headset use, were noted. ATOF transforms the user environment into an oceanic world, where participants use a dolphin-shaped smart object to complete tasks like collecting items and solving puzzles. This application aims to improve motor coordination and cognitive skills. Participants appreciated the immersive experience, the customizable tasks, and the tangible dolphin interface. However, some faced difficulties interacting with specific virtual elements. Overall, both applications demonstrated potential as therapeutic tools for NDD, offering engaging and immersive experiences. Despite some usability challenges and hardware limitations, the positive feedback suggests that TAR could play a crucial role in future therapeutic interventions. Further research is needed to refine these applications and enhance user interaction and comfort.

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Sales Skills Training in Virtual Reality: An evaluation utilizing CAVE and Virtual Avatars

This study investigates the potential of virtual reality (VR) for enhancing sales skills training using a Cave Automatic Virtual Environment (CAVE). VR technology enables users to practice interpersonal and negotiation skills in controlled, immersive environments that mimic real-world scenarios. In this study, participants engaged in sales simulations set in a virtual dealership, interacting with avatars in different work settings and with various communication styles. The research employed a within-subjects experimental design involving 20 university students. Each participant experienced four distinct sales scenarios randomized for environmental and customer conditions. Training effectiveness was assessed using validated metrics alongside custom experience questions. Findings revealed consistent user experience and presence across all scenarios, with no significant differences detected based on communication styles or environmental conditions. The study highlights the advantages of semi-immersive VR systems for collaborative learning, peer feedback, and realistic training environments. However, further research is recommended to refine VR designs, improve engagement, and maximize skills transfer to real-world applications.

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Exploring the Effects of Different Asymmetric Game Designs on User Experience in Collaborative Virtual Reality

The risk of isolation in virtual reality (VR) stems from the immersive nature of the technology. VR can transport users to entirely virtual environments, often disconnecting them from the physical world and real-life interactions. Asymmetric multiplayer options have been explored to address this issue and encourage social interaction by requiring players to communicate and collaborate to achieve common objectives. Nevertheless, research on implementing these designs and their effects is limited, mainly due to the novelty of multiplayer VR gaming. This article investigates how different game design approaches affect the player experience during an asymmetric multiplayer VR game. Four versions of a VR experience were created and tested in a study involving 74 participants. Each version differs in terms of the sharing of virtual environments (shared vs separated) and the players' dependency on the experience (mutual vs unidirectional). The results showed that variations in game design influenced aspects of the player experience, such as system usability, pragmatic UX quality, immersion control, and intrinsic motivation. Notably, the player roles and the co-presence in the virtual environment did not simultaneously impact these aspects, suggesting that the degree to which players depend on each other changes the player experience.

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Digital Twins for Extended Reality Tourism: User Experience Evaluation Across User Groups

This study evaluates the user experience (UX) in extended reality (XR) tourism of two digital twin-based applications: an Augmented Reality Virtual Tour (AR-VT) for enhanced on-site visits and a Virtual Reality Virtual Tour (VR-VT) for remote exploration. Using a quantitative exploratory approach, 84 participants from Spain and Germany, divided into three sample groups, assessed UX, task load, presence, cybersickness, and emotional response through standardized questionnaires. Findings indicate that both applications provided a low task load and high enjoyment. The VR-based tour enhanced presence but posed usability and cybersickness challenges, while the AR-based tour achieved high UX ratings, with qualitative feedback suggesting areas for refinement. Correlation analysis revealed significant relationships between age, prior XR experience, and technological affinity with the measured metrics for both applications. These results highlight the importance of well-designed experiences tailored to XR novices, reinforcing the critical role of UX in digital twin-based XR tourism.

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Finding My Way: Influence of Different Audio Augmented Reality Navigation Cues on User Experience and Subjective Usefulness

As augmented reality (AR) becomes increasingly prevalent in mobile and context-aware applications, the role of auditory cues in guiding users through physical environments is becoming critical. This study investigates the effectiveness and user experience of various categories of audio cues, including fully non-verbal sounds and speech-derived Spearcons, during outdoor navigation tasks using the Meta Quest 3 headset. Twenty participants navigated five outdoor routes using audio-only cue types: Artificial Sounds, Nature Sounds, Spearcons, Musical Instruments, and Auditory Icons. Subjective evaluations were collected to assess the perceived effectiveness and user experience of each sound type. Results revealed significant differences in perceived novelty and stimulation across sound types. Artificial Sounds and Musical Instruments were rated higher than Spearcons in novelty, while Artificial Sounds were also rated higher than Spearcons in stimulation. Overall preference was evenly split between Nature Sounds and Artificial Sounds. These findings suggest that incorporating aspects of novelty and user engagement in auditory feedback design may enhance the effectiveness of AR navigation systems.

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User-Centric Evaluation Methods for Digital Twin Applications in Extended Reality

The integration of Digital Twins with Extended Reality technologies, such as Virtual Reality and Augmented Reality, is transforming industries by enabling more immersive, interactive experiences and enhancing real time decision making. User centered evaluations are crucial for aligning XR enhanced DT systems with user expectations, enhancing acceptance and utility in real world settings. This paper proposes a user centric evaluation method for XR enhanced DT applications to assess usability, cognitive load, and user experience. By employing a range of assessment tools, including questionnaires and observational studies across various use cases, such as virtual tourism, city planning, and industrial maintenance, this method provides a structured approach to capturing the users perspective.

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Comparing Pass-Through Quality of Mixed Reality Devices: A User Experience Study During Real-World Tasks

In extended reality, pass-through enables users to view their real-world surroundings via cameras on the headset, displaying live video inside the device. This study compared the pass-through quality of three devices: Apple Vision Pro, Meta Quest 3, and Varjo XR3. Thirtyone participants performed two tasks, reading a text and solving a puzzle, while using each headset with the pass-through feature activated. Participants then rated their experiences, focusing on workload and cybersickness. Results showed that the Apple Vision Pro outperformed the Meta Quest 3 and Varjo XR3, receiving the highest ratings for pass-through quality.

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Hands vs. Controllers: Comparing User Interactions in Virtual Reality Shopping Environments

Virtual reality enables users to experience real-life situations in immersive environments. Interaction methods significantly shape user experience, particularly in high fidelity simulations mimicking real world tasks. This study evaluates two primary VR interaction techniques, hand based and controller based, through virtual shopping tasks in a simulated supermarket with 40 participants. Hand-based interaction was preferred for its natural, immersive qualities and alignment with real-world gestures but faced usability challenges, including limited haptic feedback and grasping inefficiencies. In contrast, controller-based interaction offered greater precision and reliability, making it more suitable for tasks requiring fine motor skills.

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Enhancing Job Interview Preparation Through Immersive Experiences Using Photorealistic, AI-powered Metahuman Avatars

This study will investigate the user experience while interacting with highly photorealistic virtual job interviewer avatars in Virtual Reality (VR), Augmented Reality (AR), and on a 2D screen. Having a precise speech recognition mechanism, our virtual character performs a mock-up software engineering job interview to adequately immerse the user in a life-like scenario. To evaluate the efficiency of our system, we measure factors such as the provoked level of anxiety, social presence, self-esteem, and intrinsic motivation. This research is a work in progress with a prospective within-subject user study including approximately 40 participants. All users will engage with three job interview conditions (VR, AR, and desktop) and provide their feedback. Additionally, users' bio-physical responses will be collected using a biosensor to measure the level of anxiety during the job interview.

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Single Vs Dual: Influence of the Number of Displays on User Experience within Virtually Embodied Conversational Systems

The current research evaluates user experience and preference when interacting with a patient-reported outcome measure (PROM) healthcare application displayed on a single tablet in comparison to interaction with the same application distributed across two tablets. We conducted a within-subject user study with 43 participants who engaged with and rated the usability of our system and participated in a post-experiment interview to collect subjective data. Our findings showed significantly higher usability and higher pragmatic quality ratings for the single tablet condition. However, some users attribute a higher level of presence to the avatar and prefer it to be placed on a second tablet.

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