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Publicações

Publicações por José Vasconcelos Raposo

2019

Virtual Reality for training - The impact of smell on presence, cybersickness, fatigue, stress and knowledge transfer

Autores
Narciso, D; Bessa, M; Melo, M; Vasconcelos Raposo, J;

Publicação
PROCEEDINGS OF THE 2019 INTERNATIONAL CONFERENCE ON GRAPHICS AND INTERACTION (ICGI 2019)

Abstract
The area of professional training using virtual reality technologies has received considerable investment due to the advantages that virtual reality provides over traditional training. In this paper, we present an experiment whose goal was to analyse the impact that an additional stimulus has on the effectiveness of a virtual environment designed to train firefighters. The additional stimulus is a smell, more specifically the smell of burnt wood, which is consistent with the audiovisual content presented, and the effectiveness of the VE is measured through participant's feeling of presence, cybersickness, fatigue, stress and transfer of knowledge. The results indicate that, although the VE was successful in transferring knowledge, the addition of smell did not influence any of the measured variables. In the discussion section, we present the various factors that we believe have influenced this result. As future work, more experiments will be performed, with other stimuli, to understand better which stimuli increase participant's feeling of presence in the VE.

2020

A Comparative Study Between Wired and Wireless Virtual Reality Setups

Autores
Gonçalves, G; Monteiro, P; Melo, M; Vasconcelos Raposo, J; Bessa, M;

Publicação
IEEE ACCESS

Abstract
Virtual Reality (VR) through head-mounted displays (HMDs) can be delivered via multiple setups such as smartphones, standalone VR or VR Workstations. The VR Workstation setup delivers the best performance of them all; however, as a drawback up until recently, it required cables to power up the VR equipment. The introduction of wireless solutions for VR Workstations came to solve one of the disadvantages of this setup. However, the impact of the wireless solution versus the HMD cables was not yet properly investigated. In this paper, we study the impact of using a wired vs wireless HMD on Presence, Cybersickness, and Game Experience. We conducted a quasi-experimental between-subjects study with 68 participants assigned to the following three groups that were balanced regarding gender and sample size: Cable (participants used a wired HMD), Cable & x002B; Help (a researcher assisted the participants with the HMD cable during the experience to reduce the participants; awareness of it), and Wireless (untethered HMD). Results showed no significant differences in presence and cybersickness. The game experience was significantly different, with Cable & x002B; Help performing better than Cable and Wireless. We conclude that sense of presence using wireless solutions is equated to wired HMD solutions.

2020

The Impact of Olfactory and Wind Stimuli on 360 Videos Using Head-mounted Displays

Autores
Narciso, D; Melo, M; Vasconcelos Raposo, J; Bessa, M;

Publicação
ACM TRANSACTIONS ON APPLIED PERCEPTION

Abstract
Consuming 360 audiovisual content using a Head-Mounted Display (HMD) has become a standard feature for Immersive Virtual Reality (IVR). However, most applications rely only on visual and auditory feedback whereas other senses are often disregarded. The main goal of this work was to study the effect of tactile and olfactory stimuli on participants' sense of presence and cybersickness while watching a 360 video using an HMD-based IVR setup. An experiment with 48 participants and three experimental conditions (360 video, 360 video with olfactory stimulus, and 360 video with tactile stimulus) was performed. Presence and cybersickness were reported via post-test questionnaires. Statistical analysis showed a significant difference in presence between the control and the olfactory conditions. From the control to the tactile condition, mean values were higher but failed to show statistical significance. Thus, results suggest that adding an olfactory stimulus increases presence significantly while the addition of a tactile stimulus only shows a positive effect. Regarding cybersickness, no significant differences were found across conditions. We conclude that an olfactory stimulus contributes to higher presence and that a tactile stimulus, delivered in the form of cutaneous perception of wind, has no influence in presence. We further conclude that multisensory cues do not affect cybersickness.

2020

Impact of Different Sensory Stimuli on Presence in Credible Virtual Environments

Autores
Gonçalves, G; Melo, M; Vasconcelos Raposo, J; Bessa, M;

Publicação
IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS

Abstract
Multiple factors can affect presence in virtual environments, such as the number of human senses engaged in a given experience or the extent to which the virtual experience is credible. The purpose of the present work is to study how the inclusion of credible multisensory stimuli affects the sense of presence, namely, through the use of wind, passive haptics, vibration, and scent. Our sample consisted of 37 participants (27 men and 10 women) whose ages ranged from 17 to 44 years old and were mostly students. The participants were divided randomly into 3 groups: Control Scenario (visual and auditory - N = 12), Passive Haptic Scenario (visual, auditory, and passive haptic - N = 13) and Multisensory Scenario (visual, auditory, wind, passive haptic, vibration, and scent - N = 12). The results indicated a significant increase in the involvement subscale when all multisensory stimuli were delivered. We found a trend where the use of passive haptics by itself has a positive impact on presence, which should be the subject of further work.

2020

A novel method to enhance the touristic 360° promotional video experience

Autores
Gonçalves, G; Melo, M; Vasconcelos Raposo, J; Bessa, M;

Publicação
MULTIMEDIA TOOLS AND APPLICATIONS

Abstract
Promotional 360 degrees videos are now widely used to promote touristic sites, giving consumers a more immersive glimpse of what they can expect from those places. However, these 360 degrees videos often comprise so much information that it overloads the users, not allowing them to benefit from such a rich multimedia experience. To overcome this issue, we propose and evaluate a novel method that allows the experience of immersive 360 degrees promotional videos to be more interactive and informative without overloading users. The evaluation study focuses on how the proposed interaction method performs versus the non-interactive method in terms of user satisfaction, presence, and cybersickness in both a low-immersive (computer monitor) setup and an immersive platform (head-mounted display (HMD)). Our sample (N = 50) was randomly divided into four groups: 360 degrees (computer monitor without interaction), 360 degrees Interaction (computer monitor with interaction), IVR360 degrees (HMD without interaction) and IVR360 degrees Interaction (HMD with interaction). The results show that the novel proposed method is preferred by users over the non-interactive approach regardless of the setup (low-immersive or immersive). For cybersickness, there were no differences across all the experimental scenarios. We conclude that our method has the potential to bring added value to touristic promotion when compared to conventional promotional approaches.

2021

Delivering Critical Stimuli for Decision Making in VR Training: Evaluation Study of a Firefighter Training Scenario

Autores
Monteiro, P; Melo, M; Valente, A; Vasconcelos Raposo, J; Bessa, M;

Publicação
IEEE TRANSACTIONS ON HUMAN-MACHINE SYSTEMS

Abstract
The goal for a virtual reality (VR) training system is to enable trainees to acquire all the knowledge they need to perform effectively in a real environment. Such a system should provide an experience so authentic that no further real-world training is necessary, meaning that it is sufficient to train in VR. We evaluate the impact of a haptic thermal stimulus, which is of paramount importance to decision making, on trainees performance and knowledge acquisition. A thermal device was created to deliver the stimulus. As a proof of concept, a procedure from firefighter training is selected, in which sensing the temperature of a door with one's hand is essential. The sample consisted of 48 subjects divided among three experimental scenarios: one in which a virtual thermometer is used (visual stimulus), another in which the temperature is felt with the hand (thermal stimulus) and a third in which both methods are used (visual + thermal stimuli). For the performance evaluation, we measured the total time taken, the numbers of correctly executed procedures and identified neutral planes, the deviation from the target height, and the responses to a knowledge transfer questionnaire. Presence, cybersickness, and usability are measured to evaluate the impact of the haptic thermal stimulus. Considering the thermal stimulus condition as the baseline, we conclude that the significantly different results in the performance among the conditions indicate that the better performance in the visual-only condition is not representative of the real-life performance. Consequently, VR training applications need to deliver the correct stimuli for decision making.

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