This study sought to determine if an acute bout of soccer heading adversely altered postural control and pronounced self-reported symptoms of cerebral concussion. Sixteen collegiate soccer players were randomly assigned to one of two groups: control (CG) or experimental (EG). Participants either simulated or performed 10 headers in 10 min at a ball velocity 11.2 m/s. A concussion signs and symptoms checklist was completed and postural control was assessed on four separate occasions: prior to heading (hr 0), hr 1, hr 24, and hr 48 post heading. The postural control parameters were the root mean square (RMS) of the center of mass (COM) and approximate entropy (ApEN) of the center of pressure (COP). The results indicated that there were no significant differences between the CG and EG in the sum of self-reported concussion signs and symptoms; however, there were significant alterations in postural control, occurring primarily at 24 hrs following heading. Within the EG only there were significant differences across time for anterior-posterior (AP) COM RMS for conditions 3 (i.e., rotating virtual environment [VE] and stable support surface) and 4 (i.e., rotating VE and unstable support surface). Also, medial-lateral (ML) COM RMS values were significantly higher for the EG when compared to the CG at hr 24. The EG had significantly lower COP ApEn values in both the AP and ML directions when compared to the CG at hr 24. Condition 4 was found to induce significantly greater postural control deficits when compared to the other conditions in the ML COM RMS and AP COP ApEn. These findings indicate that an acute bout of heading, even at the low velocities presented in this experiment, result in quantifiable alterations in postural control that are detectable 24 hours post heading and dissipate within an additional 24 hours. The significant findings are contrary to the acute heading literature and may be due to the postural control assessment that incorporated robust discordant environmental conditions. Further research on the clinical usefulness of the assessment as well as long-term accumulation effects of heading is warranted. / Kinesiology

Die Covid-19-Pandemie belegt eindrucksvoll die Relevanz von virtuellen Museumsräumen, welche den Zugang zu Kunst- und Kulturartefakten auch in Zeiten physischer Einschränkungen ermöglichen. Neben der unstrittigen Relevanz solch virtueller Angebote steht als weiteres wichtiges Kriterium deren Akzeptanz, die im Wesentlichen von Kriterien wie Usability und User Experience abhängt. Bislang gibt es für die Umsetzung von benutzerfreundlichen Virtual Environments (VE) nur generische Design-Guidelines, wie etwa die Heuristiken-Sammlung von Sutcliffe und Gault 2004. In diesem Beitrag untersuchen wir im Rahmen einer heuristischen Evaluation die Anwendbarkeit dieser allgemeingültigen VE-Heuristiken auf virtuelle Museumsräume. Dazu wählen wir sechs exemplarische virtuelle Ausstellungen aus und evaluieren sie bzgl. der bestehenden Heuristiken. Im Ergebnis entstehen so einerseits Best Practices zur konkreten Umsetzung virtueller Museumsräume. Andererseits diskutieren wir anhand konkreter Beispiele die Grenzen der bestehenden Heuristiken. In der Folge benennen wir zwei Heuristiken, die für den Anwendungsbereich virtueller Museen nicht geeignet scheinen. Weiterhin ergänzen wir zwei Heuristiken, welche aus den Anwendungsbeispielen abgeleitet werden konnten und argumentieren für einen weiteren Ausbau spezifischer Heuristiken und Best Practices für virtuelle Museumsräume, um so systematisch die Wissensvermittlung im Sinne des Public-History-Ansatzes zu verbessern.

Immersive virtual environments (VEs) are broadly applicable to situations where a user can directly perceive and interact with three-dimensional (3D) virtual objects. Currently, successful interactive applications of VEs are limited. Some interactive applications in the AEC (architecture / engineering / construction) domain have not yet benefited from applying VEs. A review of prior work has suggested that 3D interaction has not reached a level that meets real-world task requirements. Most interaction techniques pay little attention to the application contexts. When designers assemble these techniques to develop an interactive system, the interfaces often have very simple and not highly useful UIs. In this work, we describe a domain-specific design approach (DSD) that utilizes pervasive and accurate domain knowledge for interaction design. The purpose of this dissertation is to study the effects of domain knowledge on interaction design. The DSD approach uses a three-level interaction design framework to represents a continuous design space of interaction. The framework has generative power to suggest alternative interaction techniques. We choose the AEC domain as the subject of study. Cloning and object manipulation for massing study are the two example tasks to provide practical and empirical evidences for applying the DSD. This dissertation presents several important results of the knowledge use in the DSD approach. First, the DSD approach provides a theoretical foundation for designing 3D interaction. Techniques produced using DSD result in more useful real-world applications, at least in the domain of AEC. Second, the three-level interaction design framework forms a continuum of design and expands our understanding of 3D interaction design to a level that addresses real-world use. Third, this research proposes an integrated system design approach that integrates DSD and the usability engineering process. Fourth, this work produces a large set of empirical results and observations that demonstrate the effectiveness of domain-knowledge use in designing interaction techniques and applications. Finally, we apply domain-specific interaction techniques to real world applications and create a fairly complex application with improved usefulness. / Ph. D.

There are myriad examples of virtual communities and environments available for collaborative activities. However, most of these environments are confined to the desktop and thus preclude collaboration while users are on the move. Through a scenario-based design process, this article establishes the importance of mobile collaborative environments that are readily accessible for users on mobile devices. The element of mobile accessibility for collaborative environments renders them ubiquitous—they can be used anywhere and at any time. A working prototype is then presented that has been developed to supplement an existing desktop-based online virtual community. The prototype illustrates a generic, extensible and platform-independent architecture for translating a desktop collaborative environment into a mobile system. Based on the prototype, we also foresee its application for users in fieldwork settings, particularly for learning and educational activities of teachers, students, and peers through collaboration in a distributed environment. / Master of Science

Research has shown that head-mounted displays can produce greater presence in a virtual environment than direct-view displays. It has also been shown that after vision, haptic response is one of the most important inputs for humans in a simulated environment. This research was designed primarily to determine the performance differences associated with different display types, levels of steering force feedback, and the interaction between these two factors in a low-to-medium fidelity, PC-based driving simulator. Participants drove on a simulated driving course during which both objective driving performance data were collected (lane deviation, speed control, steering wheel angle variance, and time to the complete course) as well as subjective self-report measures including questionnaires designed to tap immersive tendencies and perceived levels of presence. Results of the research show that the use of a head-mounted display can significantly impact driving performance in terms of speed control and lane deviation. Speed control was significantly improved (increased) and lane deviation was significantly improved (decreased) in three of the four roadway segments with the use of an HMD. Results for active steering force feedback, however, showed a significantly negative effect on driving performance with an increase in average lane deviation. Descriptive statistics showed that participants preferred the HMD and D-V equally and all but one participant preferred active steering force feedback. / Master of Science

Virtual Reality has been growing in popularity and demand as technology has been substantially improved and become more readily available to the general public in the recent years. Similarly, the Architecture, Engineering and Construction industries have benefited from these advances and extensive research has been performed to adopt and streamline its utilization. An example of this adoption has been the use of Immersive Virtual Environments (IVE) as a representation of the built environment for different purposes such as building design and occupant behavior studies in the post construction stage – i.e., Human Building Interaction. This research has investigated a workflow for different alternatives of reality-capturing-based technologies that have been tested to generate a more realistic representation of the built environment regarding HBI. One of these alternatives considered was 360-image based IVEs. This alternative in particular was tested and compared by the means of a preliminary user study in order to evaluate whether it is an adequate representation of the built environment regarding HBI, and how it is compared to commonly used benchmarked Graphical based IVEs. Ultimately, participants of this user study reported a strong feeling of immersion and presence in the 360-image based IVE and showed a better performance in cognitive tasks such as reading speed and comprehension. In contrast, participants showed a better performance in object identification and finding in the Graphical based IVE. The results of our preliminary user study indicate that 360-image based IVEs could potentially be an adequate representation in the study of Human Building Interaction based on these metrics. Further research with a larger sample size should be done in performed in order to generalize any findings. / Master of Science / Virtual Reality has been growing in popularity and demand as technology has substantially improved and become more available to the general public in the recent years. Similarly, the Architecture, Engineering and Construction industries have benefited from these advances and extensive research has been performed to utilize this technology. An example of this adoption has been the use of Immersive Virtual Environments (IVE) as a representation of a building for different purposes such as design and understanding of the way occupants interact with a building. IVEs rely on using special digital goggles (called head mounted displays or HMDs) that help users immerse in a virtual environment and experience it. For this reason, our research has sought to explore different alternatives to possibly generate a more realistic immersive virtual environment that relies on immersive image-based technologies to test how humans behave, respond, and interact with a building. One of these alternatives considered was 360-degree cameras and their associated images. We sought to study whether these technologies provide an improved experience for users compared to the environments that are created through computer graphics. This thesis explains the processes that were investigated to understand the creation of an IVE, and the different alternatives available in the market to generate a 360-degree image based IVE. Then, one of these alternatives was tested and compared to a classic IVE through an experiment in order to evaluate whether 360-degree image based IVEs can be an adequate representation for building occupant interaction studies.

Recent technology developments have made possible the creation of several commercial devices and a selected number of development platforms for the inclusion of haptics (the sense of touch) in virtual environments (VE). This thesis sought to investigate and develop a better understanding of whether or not haptics or sound substitutions improved manipulation performance or usability in VE applications. Twenty-four volunteers (12 males and 12 females) participated in a 2 (haptics) x 2 (sound) x 2 (gender) mixed factorial experiment in which they completed a VE manipulation task involving the assembly and disassembly of 5 interconnecting parts. Performance for the manipulation task was measured through completion time and the number of collisions made, as well as subjective measures of usability. Results indicated that completion times were slower and collision counts were higher for males with the addition of haptics (ptime = 0.03; pcollisions<0.05), while females exhibited a smaller increase in collision counts and no increase in completion time with the addition of haptics. Nonetheless, there were improved usability attributes when haptics were incorporated, more specifically, an increased sense of realism, perceived helpfulness and perceived utility in a design task (p<0.05 for all). Sound was found to be an effective substitute for haptics in most measures taken while the combination of sound and haptics versus either alone, did not demonstrate any signs of improving performance or any usability attributes. It is therefore recommended that sound substitution be used in VE manipulation tasks where the extra haptic information is desired, and minimizing completion time or collisions are the overall goal. Finally, for the utility of the feedback towards a design task, users ranked haptics as being more useful than sound, but ranked the combination of sound and haptics as being the best feedback condition (p<0.05). Further research is required to determine whether this belief is consistent with objective measures. / Master of Science

在多人虛擬環境系統的設計上，讓使用者能自行設計化身的行為，並即時以動畫元件的形式安裝到虛擬世界中，是3D內容能否達到共享的關鍵。本論文主要研究的部分包含三個部分：第一個部分是提供虛擬環境系統動態載入動畫元件的機制，使得虛擬環境系統可以動態加入客製化之化身行為；第二個部分是在現有的虛擬環境系統中加入語意的描述，並增加互動訊息傳送時的彈性；第三個部分是實現可客製化的動畫元件，分別以化身和環境間以及化身彼此間的互動，來說明上述機制的可行性。在動態的載入動畫元件的部分，客製化的動畫元件在系統上得以即時安裝並執行。動畫元件在安裝上可使用XML片段，並交由OSGi Framework中的服務來處理此XML標籤。另外，在加入物件的語意描述後，使得這些動畫元件可以取得世界的資訊，並進一步產生符合當時環境限制或應用需求的動畫。我們以Ontology來描述環境和化身的資訊，並實際製作路徑規劃器元件和化身間互動元件兩個範例。我們利用動態安裝及語意資訊兩個機制，以實例說明如何達到實現化身可客製化行為之目的。 / In the design of multi-user virtual environments, in order to share 3D contents designed by users, it is crucial to allow the behaviors of an avatar to be designed as animation components and loaded at the run time. In this thesis, we attempt to address the problem of designing a semantic virtual environment by considering the following three parts. First, we have designed a mechanism for user-designed animation procedures to be installed and loaded at run time. Second, we have augmented our virtual environment system with semantic descriptions and enhanced the flexibility of message interchange. Third, we have used two types of interaction scenarios, avatar-environment and avatar-avatar, to illustrate how customized animation components can be designed to enhance the functionality of a virtual environment. In our system, we allow users to design their own XML tags and the corresponding animation components managed in the OSGi framework. These components can acquire world information and generate appropriate animations according to application requirements and environment constraints. We have used ontology to describe the semantics of environments and avatars. Two example components: the motion planner and the avatar-avatar interaction have been designed to illustrate the dynamic installation process and the retrieval of semantic information for the realization of customizing avatar behaviors.

We have designed a simulation that can be used to train police officers. Digital simulations are more cost-effective than a human role play. Use of force decisions are complex and made quickly, so there is a need for better training and innovative methods. Using this simulation, we are measuring the degree of presence that a human experience in a virtual environment. More presence implies better training. Participants are divided into two groups in which one group performs the experiment using a screen, keyboard, and mouse, and another uses virtual reality controls. In this experiment, we use subjective measurements and physiological measurements. We offer a questionnaire to participants before and after play. We also record the participants change in heart rate, skin conductivity and skin temperature using Empatica device. By comparing the data collected from both groups, we prove that people experience more presence in the virtual environment.

Le jeu vidéo est une activité de loisir particulièrement répandue auprès des adolescents. Néanmoins, pour certains, une conduite addictive peut se mettre en place, remplissant une fonction précise et nécessaire à l'équilibre du sujet. L'objectif de ce travail de thèse est d'amorcer la construction d'un modèle explicatif de ce processus addictif. L'opérationnalisation de cette recherche repose sur une méthodologie quantitative permettant de mesurer le poids et l'implication de variables psychopathologiques, cognitivo-émotionnelles et de personnalité dans la mise en place de cette conduite addictive. Le monde virtuel et l'avatar sont les deux constituants majeurs de tout jeu vidéo. Ils permettent au sujet de mettre en scène et médiatiser son Soi Emotionnel. Le processus addictif résulte d'une cristallisation de cette dynamique, ne permettant pas au sujet de se réapproprier son expérience émotionnelle. Par ailleurs, ce travail a permis de mettre en avant l'existence d'une utilisation addictive des jeux vidéo en ligne et hors ligne. Ces deux formats se différencient dans la mise en scène d'aspects du Soi Identitaire qu'ils impliquent. Pour finir, ce travail nous amène à questionner la frontière entre une utilisation régulière et addictive/pathogène des jeux vidéo. / Video games cover preferential activity of adolescents. But for some, the practice becomes an addictive behavior, playing an important role in psychological functioning of adolescents. The global aim is to establish a comprehensive model of this addictive process. This research is based on a quantitative methodology in order to assess the weight and the involvement of psychopathological, emotional and personality variables in this addictive process. Avatar and virtual world are the two essential components of any video game. They allow subject to mediatize and enact his Emotional Self. The addiction process is the result of crystallization of this dynamic which does not allow the subject to reappropriate his emotional experience. Furthermore, the research puts the light on two different types of addictive processes with on line or outline video games. These two formats differ in the enacting of aspects of the Self Identity they imply. Finally, this work leads us to question the boundary between regular and addictive / pathogen use of video games.