2020
Authors
Krassmann, AL; Rocha Mazzuco, AEd; Melo, M; Bessa, M; Bercht, M;
Publication
Proceedings of the 12th International Conference on Computer Supported Education, CSEDU 2020, Prague, Czech Republic, May 2-4, 2020, Volume 1.
Abstract
This case study presents a virtual reality experts' evaluation of a desktop-based virtual world developed towards distance education, under the perspectives of usability and sense of presence, which are considered factors that can potentially influence learning outcomes. Among the results, data from usability and sense of presence were positively correlated. The sense of presence was achieved, with participants losing track of time while performing the activity. Experts agreed that the virtual world is easy to use and can prepare students for the real-world task. The findings outline positive and negative points that must be addressed in order to optimize the experience of distance education students. Copyright
2020
Authors
Coelho, H; Melo, M; Martins, J; Bessa, M;
Publication
MULTIMEDIA TOOLS AND APPLICATIONS
Abstract
In the original publication, Figs. 1 and 2 were interchange and the citation of Fig. 1 in the third paragraph of section 2.2 Authoring tools for multisensory VR experiences should be removed.
2020
Authors
Goncalves, G; Melo, M; Vasconcelos Raposo, J; Bessa, M;
Publication
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
Authors
Goncalves, G; Melo, M; Vasconcelos Raposo, J; Bessa, M;
Publication
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.
2020
Authors
Krassmann, AL; Melo, M; Peixoto, B; Pinto, D; Bessa, M; Bercht, M;
Publication
Virtual, Augmented and Mixed Reality. Industrial and Everyday Life Applications - 12th International Conference, VAMR 2020, Held as Part of the 22nd HCI International Conference, HCII 2020, Copenhagen, Denmark, July 19-24, 2020, Proceedings, Part II
Abstract
The goal of this study is to examine the effects of the sense of presence and immersive tendencies on learning outcomes while comparing different media formats (Interactive VR, Non-interactive VR and Video). An experiment was conducted with 36 students that watched a Biology lesson about the human cells. Contrary to expected, the results demonstrate that the Non-interactive VR was the most successful format. Sense of presence and immersive tendencies did not have an effect on learning gain, and the latter was not a critical factor to experience the sense of presence. The findings provide empirical evidence to help understand the influence of these variables on learning in VR. © 2020, Springer Nature Switzerland AG.
2020
Authors
Mukherjee, R; Melo, M; Filipe, V; Chalmers, A; Bessa, M;
Publication
IEEE ACCESS
Abstract
Convolution Neural Network (CNN)-based object detection models have achieved unprecedented accuracy in challenging detection tasks. However, existing detection models (detection heads) trained on 8-bits/pixel/channel low dynamic range (LDR) images are unable to detect relevant objects under lighting conditions where a portion of the image is either under-exposed or over-exposed. Although this issue can be addressed by introducing High Dynamic Range (HDR) content and training existing detection heads on HDR content, there are several major challenges, such as the lack of real-life annotated HDR dataset(s) and extensive computational resources required for training and the hyper-parameter search. In this paper, we introduce an alternative backwards-compatible methodology to detect objects in challenging lighting conditions using existing CNN-based detection heads. This approach facilitates the use of HDR imaging without the immediate need for creating annotated HDR datasets and the associated expensive retraining procedure. The proposed approach uses HDR imaging to capture relevant details in high contrast scenarios. Subsequently, the scene dynamic range and wider colour gamut are compressed using HDR to LDR mapping techniques such that the salient highlight, shadow, and chroma details are preserved. The mapped LDR image can then be used by existing pre-trained models to extract relevant features required to detect objects in both the under-exposed and over-exposed regions of a scene. In addition, we also conduct an evaluation to study the feasibility of using existing HDR to LDR mapping techniques with existing detection heads trained on standard detection datasets such as PASCAL VOC and MSCOCO. Results show that the images obtained from the mapping techniques are suitable for object detection, and some of them can significantly outperform traditional LDR images.
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