High thermal conductivity ceramics

For efficient collaboration between participants, eye gaze is seen as being critical for interaction. Teleconferencing systems such as the AcessGrid allow users to meet across geographically disparate rooms but as of now there seems no substitute for face to face meetings. This paper gives an overview of some preliminary work that looks towards integrating eye gaze into an immersive Collaborative Virtual Environment and assessing the impact that this would have on interaction between the users of such a system. An experiment was conducted to assess the difference between users abilities to judge what objects an avatar is looking at with only head gaze being viewed and also with eye and head gaze data being displayed. The results from the experiment show that eye gaze is of vital importance to the subjects correctly identifying what a person is looking at in an immersive virtual environment. This is followed by a description of how the eye tracking system has been integrated into an immersive collaborative virtual environment and some preliminary results from the use of such a system.

To further the study of learning in the context of immersive virtual technologies, this systematic literature review addressed the following research questions: ‘How is self-efficacy being studied in immersive virtual learning environments?’ ‘What kinds of self-efficacy findings have been made in immersive virtual learning environments?’ The peer-reviewed book chapters and journal articles included in this study were published in English between January 2014 and January 2020. A narrative synthesis was created for understanding the various aspects of the topic. During the process, the scarcity of experimental research on self-efficacy in immersive virtual learning environments was revealed. The results bring to light the mixed self-efficacy findings in the context of immersive virtual learning and underline the importance of ensuring the quality of the experimental designs in future research. The study of self-efficacy in this context is suggested to benefit from increased attention to the questions of methodology and measurement. To further the goals of immersive virtual learning research, extending the participant base of the experiments by engaging in working life collaboration is strongly recommended.

An immersive virtual environment (IVE) modeling and simulation tool is being developed for designing advanced weapon and training systems. One unique feature of the tool is that the design, and not just visualization of the design is accomplished with the IVE tool. Acceptance of IVE tools requires comparisons with current commercial applications. In this pilot study, expert users of a popular desktop 3D graphics application performed identical modeling and simulation tasks using both the desktop and IVE applications. The IVE tool consisted of a head-mounted display, 3D spatialized sound, spatial trackers on head and hands, instrumented gloves, and a simulated speech recognition system. The results are preliminary because performance from only four users has been examined. When using the IVE system, users completed the tasks to criteria in less time than when using the desktop application. Subjective ratings of the visual displays in each system were similar. Ratings for the desktop controls were higher than for the IVE controls. Ratings of immersion and user enjoyment were higher for the IVE than for the desktop application. These results are particular remarkable because participants had used the desktop application regularly for three to five years and the prototype IVE tool for only three to six hours.

There are increasing new advances in virtual reality technologies as well as a rise in immersive virtual environments research and user experience research. Within this framework, we decided to address the overall user experience in immersive virtual environments. Indeed, in our point of view, this topic is not fully dealt with in the scientific literature, neither in terms of user experience components nor in terms of user experience measurement methods. It is in this context that we conducted a study aiming at proposing and validating a unified questionnaire on user experience in immersive virtual environment(IVEQ). Our questionnaire contains 10 subscales measuring presence, engagement, immersion, flow, usability, skill, emotion, experience consequence, judgement and technology adoption. The construction of our questionnaire was based on existing ones. It was tested on 116 participants after they use the edutainment virtual environment "Think and Shoot". Results show that 9 out of 10 subscales and 68 out of 87 items are reliable as demonstrated by an internal consistency analysis with Cronbach's alpha and an item analysis. Findings also indicate that the scale scores from 6 subscales are considered normal distributed (e.g. presence) whereas the scale scores from 3 subscales are considered negatively skewed (e.g. skill). This study provides important new insight into UX in IVEs assessment.

This chapter examines virtual environments which usually represent computer simulated environments, otherwise called virtual worlds or virtual reality and its application in physical therapy. Virtual environments present computer-generated three-dimensional (3D) representation of a physical presence of places in the real world as well as in the imaginary world. Users mainly interact with virtual environments using virtual reality headsets. Many of the current virtual reality environments are primarily visual experiences display either on a computer screens or through other stereoscopic displays. Applications of virtual environments are mainly focused on artificial reality that projects users into a 3D space generated by the computer with some sort of tracking devices which may be the virtual reality headsets worn or another 3D tracking device attached to the body of the user such as the electromagnetic tracker system. Research in virtual environments has made significant impact in the entertainment industry and in the training field such as the flight simulator (Stern, 1995).

In this study, we examined the perception and understanding of spatial volumes within immersive and non-immersive virtual environments by comparison with representation using conventional media. We examined the relative effectiveness of these conditions in enabling the translation to a tangible representation, through a series of design experiments. Students experienced, assessed, and analysed spatial relationships of volumes and spaces and subsequently constructed real models of these spaces. The goal of our study is to identify how designers perceive space in Virtual Environments (VEs). We explore issues of quality, accuracy and understanding of reconstructing architectural space and forms. By comparison of the same spatial performance task undertaken within a Head Mounted Display, screen-based and real 2D environment, we are able to draw some conclusions about spatial understanding in immersive VE activity.

In order for humans to act effectively in their environment, it is important for the visual system to determine the absolute size and distance of objects. Some measures of distance perception, characterized as visually directed walking tasks [Rieser et al. 1990; Loomis et al. 1992], indicate that humans are good at solving this problem given distances ranging from 2 to 25 meters in full-cue real-world environments. One example of this type of task is direct blind walking, in which observers walk without vision to previously viewed targets on the ground. Despite accurate behavior in the real-world, recent research in immersive virtual environments (VEs) using head-mounted displays (HMDs) has consistently found compression of distance to targets on the floor given the same blind walking tasks [Loomis and Knapp 2003; Thompson et al. in press].

It is well known that distance estimation in immersive virtual reality environments suffers from compression when viewed from an egocentric perspective with a head mounted display. While previous research indicates that providing the user with a virtual avatar with high geometric and motion fidelity may alleviate this problem, little work has been done to investigate which properties of the avatar's representation influence the distance estimation and how. In this poster we report the results of an evaluation of the user's distance perception with different avatar representations. Our results indicate that anthropometric fidelity of the avatar has stronger effect on the distance perception than its visual fidelity.

Increasingly, business pressures drive development projects toward global development in which the systems and software development team is distributed over two or more geographical locations. Co-location allows improved communication, confidence, familiarity, and trust that facilitate rapid information sharing, mentoring, problem resolution, and so on. Previous observations indicate that improving the speed and cost of software development while distributing it across a global team requires remediation, likely the acquisition and deployment of collaboration technology. This paper describes an ongoing corporate experiment aimed at improving collaborative software development that is increasingly spread over 4 continents, 7 countries, and over 20 regional facilities. It involves the use of an immersive networked virtual environment (NVE) for the development of aviation electronics.

Gamepads and 3D controllers are the main controllers used in most Virtual Environments. Despite being simple to use, these input devices have a number of limitations as fixed layout and difficulty to remember the mapping between buttons and functions. Mobile devices present interesting characteristics that might be valuable in immersive environments: more flexible interfaces, touchscreen combined with onboard sensors that allow new interaction and easy acceptance since these devices are used daily by most users. The work described in this article proposes a solution that uses mobile devices to interact with Immersive Virtual Environments for selection and navigation tasks. The proposed solution uses the mobile device camera to track the Head-Mounted-Display position and present a virtual representation of the mobile device screen; it was tested using an Immersive Virtual Museum as use case. Based on this prototype, a study was performed to compare controller based and mobile based interaction for navigation and selection showing that using mobile devices is viable in this context and offers interesting interaction opportunities.

In this paper, a method to link CAD models to an immersive virtual environment is proposed. CAD models cannot be viewed directly in a real-time visualization environment. CAD models have to be adapted to be viewed in an immersive environment with high quality rendering. The proposed method allows design review in application requesting high quality complex scene visualization in immersive virtual environment. Our application is dedicated to an immersive room called the MoVE (Mobile Virtual Environment). This display offers a particular place to the user. User is inside the virtual world. This position allows us to take care of the peripheral.

Purpose The paper aims to provide an integrated system for collaborative maintenance training of complex equipment based on virtual maintenance and immersive virtual reality environment. Design/methodology/approach An integrated platform for collaborative virtual maintenance operation and training of complex equipment is developed. The simulation supporting platform for collaborative virtual maintenance is designed with the combined hierarchical structure and modularized members to support the interactive communication of heterogeneous data and information. By analyzing the collaboration mode of multi operators, the maintenance task allocation model, maintenance operation model and Extensible Markup Language-based object information template are presented. Findings The research finds that the proposed system is an efficient platform for collaborative maintenance training of complex equipment. Practical implications Appropriate and efficient maintenance task allocation and collaborative maintenance operation of multi operators can significantly improve the maintenance efficiency of complex equipment. Originality/value A collaborative virtual maintenance training system of complex equipment based on immersive virtual reality environment is presented.

The effects of the presence of others during a rowing exercise in a virtual reality environment

2D human-computer interaction techniques in immersive virtual environments

Event Abstract Back to Event Effect of visual field motion on vestibulo-myogenic response during upright stance: A pilot study Yawen Yu1, 2* and Emily A. Keshner1 1 Temple University, Physical Therapy, United States 2 Shriners Hospitals for Children - Philadelphia, United States BACKGROUND Maintaining upright stance requires the continuous update on sensory information from the primary systems in order to estimate the current state of postural orientation (Peterka, 2002). While each sensory system is responsible for unveiling a specific aspect of body motion, changes in one sensory system can also alter sensory input from another sensory system. This process of adjusting sensory contributions to balance control is referred to as sensory reweighting (Asslander & Peterka, 2014). Sensory reweighting would explain why the magnitude of the postural response due to galvanic vestibular stimulation (GVS) is dependent upon non-vestibular sensory signals (Fitzpatrick & Day, 2004). A much greater postural response can be elicited by GVS, when visual information is made unavailable (Welgampola & Colebatch, 2001). Individuals standing quietly in an immersive virtual environment where the visual surround is continuously moving exhibit postural sway in the direction of the visual flow (Wang, Kenyon, & Keshner, 2010). Thus, vestibular reafference could be modulated by visual flow as it is by fear of falling (Naranjo, Allum, Inglis, & Carpenter, 2015) and weakened muscle strength around the ankle (McIntosh, Power, & Dalton, 2018). The purpose of the current study was to explore whether vestibular reafference would be modulated by visual field motion. Results of this study provide a physiological interpretation for changes in the postural response due to visual field motion. METHODS Subjects: Eight healthy young adults (8 females; 28.0 ± 6.0 years) with no history of neurological disorder gave informed consent to participate in the current study. All subjects had no known history of vestibular or hearing deficit. All participants had a minimum of 20/40 corrected vision. The experimental protocol was approved by the Temple University Ethics Board. Using the Rod-and-Frame test, all participants were identified as visually independent (Yu, Lauer, Tucker, Thompson, & Keshner, 2018). Virtual Environment: The immersive virtual environment consisted of three screens facing the front, right, and left of the subject. The overall dimension of the virtual environment was 3.5m (width), 3.5m (depth), and 6.1m (height). One Panasonic PT-DX610 DLP-based projectors positioned behind each screen projected a full-color field with the resolution of 1024x768 pixels at a 60 Hz refresh rate. The image of the virtual environment was created in Unity (Unity Technologies SF, San Francisco, CA, USA). Vestibular Evoked Myogenic Potential (VEMP): Acoustic air-conducted stimulation consisting of 500Hz, 125dB SPL tone bursts, with 1ms rise/fall time, 2ms plateau, at a repetition rate of 5 Hz, was delivered monaurally though in-ear earphones (ER-3C, Etymotic Research Inc., Elk Grove Village, IL, USA). The electromyogram (EMG) signals representing cervical vestibular evoked myogenic potential (cVEMP) responses were recorded with disposable, self-adhesive, pre-gelled, Ag/AgCl electrodes with 40-inch safety leadwires (GN Otometrics, Schaumbaurg, IL, USA), which were amplified (2500x) and band-pass filtered (20 – 2000Hz) for cVEMPs. A non-inverting electrode was placed at the mid-point of the sternocleidomastoid (SCM) muscle on each side. An inverting electrode was placed at the sternoclavicular junction on each side. A ground electrode was placed on the manubrium sterni. Procedure: Participants were instructed to perform quiet stance in the center of the virtual environment. For left cVEMP testing, for example, participants were asked to look over the right shoulder to face the front screen with their body parallel to the left screen and actively contract the left SCM throughout the trial. During each 20-second trial, the visual field motion was kept either stationary (EO) or continuously rolling about the nasion-to-inion axis (RU) at 30°/s. Additionally, the acoustic air-conducted stimulation (100 tone-bursts) was delivered over the 20-second period. Three trials were performed for each condition on each side. Response parameters: The cVEMP waveform consists of a positive peak (p13), identified as the first distinctive valley in the waveform that appears 11ms – 16ms post tone burst, and a negative peak (n23), identified as the first distinctive peak in the waveform that appears 18ms – 26ms post tone burst. Mean values for cVEMP latencies and amplitudes were calculated separately for p13 and n23; peak-to-peak (p13-n23) amplitudes were also calculated. Muscle background activity of each SCM was calculated using the area under the curve of the rectified EMG over the 10ms window pre-stimulus. Statistical Analysis: Paired-sample t-tests were used to compare differences between EO and RU conditions for all dependent measures with the level of statistical significance set at p = 0.05. RESULTS A significant effect of visual field motion emerged in cVEMP amplitudes (p=.014). Specifically, the p13 amplitudes were significantly reduced by the RU visual scene condition (Figure 1; EO: 21.1±4.2 uV; RU: 17.7±3.7 uV). No significant differences between the stationary and roll visual conditions were found in n23 amplitudes, p13 and n23 latencies, and p13-n23 peak-to-peak amplitudes or in the background EMG activity (ps>.05). DISCUSSION Changes in the magnitude of the cVEMP suggest that vestibular reafference was modulated by visual field motion in the virtual environment even though all of the healthy participants in this study were identified as visually independent. To our knowledge, this is the first study to elicit and record VEMPs during upright stance with different conditions of visual field motion. These results provide a foundation for future studies examining vestibulo-myogenic responses in individuals with visual dependence due to neurological disorders (e.g., stroke, cerebral palsy). Comparison of vestibulomyogenic responses as a function of illusion of self-motion due to visual field motion (or vection) could further explain how the nervous system weights these signals in the natural environment. Figure 1 Acknowledgements This work is supported by the Shriners Hospitals for Children Postdoctoral Fellowship (#84308-PHI) to Yawen Yu. References Asslander, L., & Peterka, R. J. (2014). Sensory reweighting dynamics in human postural control. J Neurophysiol, 111(9), 1852-1864. doi: 10.1152/jn.00669.2013 Fitzpatrick, R., & Day, B. (2004). Probing the human vestibular system with galvanic stimulation. Journal of Applied Physiology, 96, 2301-2316. doi: 10.1152/japplphysiol.00008.2004. McIntosh, E. I., Power, G. A., & Dalton, B. H. (2018). The vestibulomyogenic balance response is elevated following high-intensity lengthening contractions of the lower limb. Neurosci Lett. doi: 10.1016/j.neulet.2018.03.056 Naranjo, E. N., Allum, J. H., Inglis, J. T., & Carpenter, M. G. (2015). Increased gain of vestibulospinal potentials evoked in neck and leg muscles when standing under height-induced postural threat. Neuroscience, 293, 45-54. doi: 10.1016/j.neuroscience.2015.02.026 Peterka, R. J. (2002). Sensorimotor integration in human postural control. J Neurophysiol, 88(3), 1097-1118. Wang, Y., Kenyon, R. V., & Keshner, E. A. (2010). Identifying the control of physically and perceptually evoked sway responses with coincident visual scene velocities and tilt of the base of support. Exp Brain Res, 201(4), 663-672. doi: 10.1007/s00221-009-2082-0 Welgampola, M. S., & Colebatch, J. G. (2001). Vestibulospinal reflexes: quantitative effects of sensory feedback and postural task. Exp Brain Res, 139(3), 345-353. Yu, Y., Lauer, R. T., Tucker, C. A., Thompson, E. D., & Keshner, E. A. (2018). Visual dependence modifies postural sway responses to continuous visual field motion in individuals with cerebral palsy. Dev Neurorehabil. doi: 10.1080/17518423.2018.1424265 Keywords: virtual environment, posture and balance, sensorimotor integration, Vestibular evoked myogenic potential (VEMP), Vection Conference: 2nd International Neuroergonomics Conference, Philadelphia, PA, United States, 27 Jun - 29 Jun, 2018. Presentation Type: Oral Presentation Topic: Neuroergonomics Citation: Yu Y and Keshner EA (2019). Effect of visual field motion on vestibulo-myogenic response during upright stance: A pilot study. Conference Abstract: 2nd International Neuroergonomics Conference. doi: 10.3389/conf.fnhum.2018.227.00086 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Apr 2018; Published Online: 27 Sep 2019. * Correspondence: PhD. Yawen Yu, Temple University, Physical Therapy, Philadelphia, PA, United States, yawen.yu@colostate.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Yawen Yu Emily A Keshner Google Yawen Yu Emily A Keshner Google Scholar Yawen Yu Emily A Keshner PubMed Yawen Yu Emily A Keshner Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.