Transactions of the Virtual Reality Society of Japan
Online ISSN : 2423-9593
Print ISSN : 1344-011X
ISSN-L : 1344-011X
Volume 26, Issue 1
Displaying 1-14 of 14 articles from this issue
  • Ryosuke Kasai, Fuminori Kamijo, Tetsuya Shimamine, Takashi Kano, Minor ...
    2021 Volume 26 Issue 1 Pages 4-13
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    We evaluated the impact of different mood states on electroencephalogram (EEG) activity and surface sensation electrical current values using surface sensory nerve electrical stimulation in a virtual reality (VR) environment. The participants were 22 adults. The Profile of Mood States (POMS) was used as a psychological test to calculate the Total Mood Disturbance (TMD) score to divide participants into a high TMD group and a low TMD group. Three videos were selected for each of three different conditions (resting, unpleasant, pleasant) for a total of nine videos. Pain Vision was used to calculate the pain ratio (PR) to evaluate surface sensory nerve electrical stimulation. A subjective pain questionnaire was used to calculate the pain subjective score (PS) to assess participants’ subjective evaluations of pain. The θ wave rate (θ%), α wave rate (α%), and β wave rate (β%) were calculated for the EEG. Analysis results demonstrated that when mood was positive, PS was lower for all VR videos, but when mood was negative, PR, PS, and α% were lower and β% was higher for unpleasant and pleasant videos. Our study findings suggest that pain may be mitigated subjectively when mood is positive, and when mood is negative, it may be mitigated both subjectively and objectively as demonstrated by electrical stimulation.

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  • Yuya Nishimaki, Naokazu Goda, Miyuki G. Kamachi
    2021 Volume 26 Issue 1 Pages 14-21
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    Previous studies on virtual reality (VR) suggested that the inclusion of wind or air flow in combination with audiovisual information can enhance the sensation of presence. However, the perceptual nature of wind in such a situation remains unknown. Using a VR environment with a head-mounted display, this study examined how observers feel real wind while viewing a fluttering flag or fallen leaves as wind flows in the virtual space. The results demonstrated that the tactile (cutaneous) perception of the intensity of wind varied depending on the virtual wind speed. This visuo-tactile crossmodal effect tended to be stronger for weaker real wind irrespective of the direction incongruence between real and virtual winds. These findings provide new insights into the multisensory nature of wind perception with contributions to the design of an efficient wind display system in VR.

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  • Yuki Kato, Kazuya Nagamachi, Maki Sugimoto, Masahiko Inami, Michiteru ...
    2021 Volume 26 Issue 1 Pages 22-31
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    Pseudo physical contact is used for communication in virtual environments such as VRChat. We hypothesized that the pseudo physical contact could affect interpersonal impression and communication, and the interpersonal impression would be modulated by appearance of body or avatar type. To test these hypotheses, we performed a questionnaire survey for VRChat users (N=341). In results, interpersonal impression and communication difficulty were improved after the pseudo physical contact, but the avatar type did not modulate the interpersonal impression. These results suggest that the pseudo physical contact could improve the interpersonal impression and communication in virtual environments.

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  • Shuhei Takagi, Masayuki Iwata, Hideki Banno, Yasuyuki Yanagida
    2021 Volume 26 Issue 1 Pages 32-41
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    It has been reported that communication difficulties caused by hearing loss can lead to depression and cognitive decline. There are various ways to improve audibility by processing the original voice and presenting it to the listeners. This research aims to develop an intelligent hearing aid that has not only the ability to amplify and process the outer sound waves but also the ability to modify the speed of speech. In this paper, we designed two methods for improving audibility by speech rate conversion in real time: CE (Consonant Elongation) system and FE (Forward Elongation) system. In the CE system, only the consonant part of the word is elongated, whereas in the FE system, only the first half of the word is elongated. Both methods are designed to prevent the word lengths from being elongated excessively. We evaluated these two methods and found that the percentage of correct responses using the FE system was higher than that of the original voice.

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  • Hanako Ikeda, Shigeo Yoshida, Tomohiro Arai, Takuji Narumi
    2021 Volume 26 Issue 1 Pages 42-51
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    This study aims to develop a method that enables the person to accept recommended make-up looks positively as the make-ups looking suit them. Participants made up with a make-up simulator using face images otherized from their self-face perceived as a different person’s face so that they have a holistic view of their self-faces. After repeating make-up on the modified faces, their impression on the recommended make-up style was improved. However, participants who repeated made-up on the original self-face did not show the improvement of impression. This result supports the possibility that the intervention of make-up on a modified self-face could improve voluntary positive acceptance of the make-up change.

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  • Miyu Sakai, Rina Yonami, Jun’ichi Murakami, Ikuhisa Mitsugami, Noriko ...
    2021 Volume 26 Issue 1 Pages 52-61
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    It was reported that an individual’s perceived happiness level affects their ability of visual search. In that work, however, the visual search task was performed on a small smartphone display. It is unclear whether this tendency is effective even under more general conditions, like in our daily lives. This work thus expands the small search area to all circumferences by introducing VR techniques to investigate whether the tendency is effective under such conditions. We employed a pop-out and serial visual search paradigm, and implemented a VR game that records search times and self-rated levels of happiness. We experimentally confirmed that we were able to replicate the classic visual search findings; while the pop-out search times remained unaffected by the number of distractors, the serial search times increased as it increased. We also confirmed the serial search times under a particular condition were significantly faster for high happiness levels than low happiness levels.

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  • Tadao Maekawa, Emi Nishina, Norie Kawai, Rikka Oomura, Manabu Honda, T ...
    2021 Volume 26 Issue 1 Pages 72-75
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    Abstract: Local exponents of fractal dimension were calculated for photos of Jomon potteries and Yayoi potteries by using the box-counting method. The local exponents of fractal dimension of Jomon potteries showed stably higher values above 2.65. In contrast, those of Yayoi potteries fluctuated widely within the comparatively lower range below 2.65. Present results suggest that the texture of Jomon pottery is more complex and denser than that of Yayoi pottery.

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  • Noriki Mochizuki, Sousuke Nakamura
    2021 Volume 26 Issue 1 Pages 76-85
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    In the current immersive VR system, the motion of the virtual body that the user operates is limited to what can be performed in real body, since the natural real body motion is generally used as a system input. Therefore, in this research, we propose the concept of “Motion-Less VR” which is an immersive VR interface that does not require the real body motion. The interface is consisted of the functions which are; sensing joint torque while the real body is mechanically restrained, calculating virtual motion through forward dynamics, and presenting motion information. As a first step, we developed a basic system and potential feasibility was evaluated.

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  • Tomohiro Amemiya, Kazuma Aoyama, Kenichiro Ito
    2021 Volume 26 Issue 1 Pages 86-95
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    Due to COVID-19, university lectures in Japan faced a change of face-toface lecture to a live online lecture. However, students at home need extra efforts to stay engaged to online lectures. This paper aims to increase engaged participants by changing the instructorߣs face shown over the lecture slide. First, students selected an in-favor and out-of-favor instructor photo which was both used to animate facial expressions in real-time using an open source deepfake software “Avatarify”. Students posted comments during the lecture and answered a simple quiz at the end. No significant difference was found for the quiz result, although the number of posting comments increased for the favorable photo. Therefore, we speculate that facial appearance influences the engagement of student participation in a live online lecture.

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  • Hiroki Yoshioka, Toshiyuki Amano
    2021 Volume 26 Issue 1 Pages 96-106
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    In this paper, we propose a light-field feedback system that realizes the appearance manipulation depending on the viewing direction. The proposed method employs a reflection model for the multiple projectors and multiple cameras, and our pseudo inverse for MIMO (multiple input, multiple output) system enables stable light-field feedback. Through the experiments, we confirmed that the system allowed appearance manipulation not only on the mirror reflection but also retro-reflection surface that cannot accomplish without light-field feedback. Besides, we confirmed our method achieved robust appearance manipulation against disturbances such as ambient light change.

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  • Kenta Yamamoto, Daisuke Iwai, Kosuke Sato
    2021 Volume 26 Issue 1 Pages 107-116
    Published: 2021
    Released on J-STAGE: April 01, 2021
    JOURNAL FREE ACCESS

    In this paper, we propose the construction of a new Projector-Camera system (ProCams), in which the pixels of the projection and imaging planes are identical. In Dynamic Projection Mapping (DPM), accurate pixel correspondence between the projector and the camera is essential to achieve precise geometric alignment of projection images. For practical calibration, it is difficult to obtain accurate pixel correspondence. To fundamentally solve the problem, we focused on Bidirectional OLED, which combine a photodiode and RGB Organic Light Emitting Diodes (OLED) in a pixel unit. This paper verifies the availability of a pixel-matching ProCams using Bidirectional OLED in DPM.

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