Transactions of the Virtual Reality Society of Japan
Online ISSN : 2423-9593
Print ISSN : 1344-011X
ISSN-L : 1344-011X
Volume 9 , Issue 4
Showing 1-16 articles out of 16 articles from the selected issue
  • Type: Cover
    2004 Volume 9 Issue 4 Pages Cover1-
    Published: December 31, 2004
    Released: February 01, 2017
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  • Type: Index
    2004 Volume 9 Issue 4 Pages Toc1-
    Published: December 31, 2004
    Released: February 01, 2017
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  • Type: Index
    2004 Volume 9 Issue 4 Pages Toc2-
    Published: December 31, 2004
    Released: February 01, 2017
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  • Makoto Yoshizawa, Tohru Kiryu
    Type: Article
    2004 Volume 9 Issue 4 Pages 341-
    Published: December 31, 2004
    Released: February 01, 2017
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  • Keiji Ohta, Takashi Kawai, Yoshimitsu Ebine, Rie Yamaguchi
    Type: Article
    2004 Volume 9 Issue 4 Pages 343-351
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    We simulated videogame scenes in simplified 3D computer graphics and evaluated the discomfort from the images by altering the simulation parameters. In the evaluation, the subjects viewed the images including oscillating motion and rotating motion with or without a fixation object. The subjective symptoms on the discomfort of image, degree of motion sickness, sense of eye movement and body movement were assessed by a 5 point rating questionnaire. Besides, the eye movements during viewing the stimuli were measured by using video camera. We found a significant relationship between the discomfort of the images and the sense of eye movement under the condition of oscillating motion. Moreover, the eye movements were reduced by adding the fixation object into the images.
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  • Hiroyuki Umemura, Hiroshi Watanabe, Katsunori Matsuoka
    Type: Article
    2004 Volume 9 Issue 4 Pages 353-360
    Published: December 31, 2004
    Released: February 01, 2017
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    Prediction of risky behaviors during walking will help design of environments and education of road safety. However, many restrictions are inevitably imposed on experimental investigations about the behavior because it is difficult to remove the risk of accidents and to control experimental variables in real spots. Using virtual reality (VR) is expected to lighten these restrictions. In this study, we performed behavioral experiments in an immersive virtual reality system. In the experiments, a moving obstacle was displayed in the VR system and subjects were required to walk from a start point to a goal point without collision with the obstacle. With these experimental results, we estimated a parameter in the model for path selection behavior; the parameter is assumed to reflect each subject's personality. The estimated parameter highly correlated with some of personality factors acquired from personality questionnaire. These results indicate that personality profiles closely relate with the path selection behavior, and the personality factors can be used as important information for improving the accuracy of the model for the path selection behavior.
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  • Tohru Kiryu, Yoko Nambo, Eri Nomura, Takehiko Bando, Naoki Kobayashi
    Type: Article
    2004 Volume 9 Issue 4 Pages 361-368
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    There are some problems in relation to unpleasant feeling or cybersickness due to visual stimulus produced by current digital imaging technology. We specified the time-frequency representation (TFR) of image motion vectors that would affect the autonomic nervous activity under vection-induced images. Referring to the trigger points of cybersickness determined by autonomic nervous activity related indices, we found that the TFR contains both the lower frequency components under 3 Hz with several seconds and the higher frequency components with several hundreds milliseconds. Moreover, the similarity between different image motion vectors, which characterizes the TFR by cos29 between different vectors, changed similarly as the distribution of trigger points of cybersickness in time.
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  • Norihiro Sugita, Makoto Yoshizawa, Akira Tanaka, Ken-ichi Abe, Tomoyuk ...
    Type: Article
    2004 Volume 9 Issue 4 Pages 369-375
    Published: December 31, 2004
    Released: February 01, 2017
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    To quantitatively assess the effect of visually-induced motion sickness, a swaying motion picture was shown to 55 subjects, and their maximum cross-correlation coefficient (ρmax) between Mayer wave-related component in blood pressure variability and that in heart rate variability was analyzed. The physiological index ρmax reflects the state of baroreflex function governed by the autonomic nervous system. In the case of the subject group with extremely high total score in the simulator sickness questionnaire (SSQ), the decrease in ρmax could be observed at two positions in time, i.e., around one minute and around ten minutes after the beginning of presentation. Such biphasic response can lead to the hypothesis that the symptom caused by visually-induced motion sickness can be divided into two parts: the reflective response to avoid the unpleasant visual image and the cumulative symptom corresponding to feeling of sickness. To verify this hypothesis, an unpleasant video film including surgical operation and no swaying scenes was presented to the same subjects. The comparison between the swaying video and the unpleasant video showed that the responses of ρmax were partly similar to each other in the case of the subject group with high self-evaluated susceptibility to motion sickness.
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  • Hiroyasu Ujike, Kazuhiko Ukai, Shinya Saida
    Type: Article
    2004 Volume 9 Issue 4 Pages 377-385
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    The study investigates the following two: (i) what types of visually-simulated body motion tends to elicit stronger motion sickness, and (ii) the effects of visual pattern on visually-induced motion sickness. To do this, we showed observers two different visual scenes, random-dots and ordinary scene, with six different types of visual motion corresponding to virtual body movements of rotation and translation along three orthogonal axes. The results showed that: (a) roll motion yielded the largest subjective score of both motion sickness and vection, and (b) no difference of the sickness between the two different scenes used for eliciting the sickness. We speculated that cognitive information, such as information of gravitational direction included in the ordinary scene, does not affect the sickness at least for those visual simulations of simple body motion.
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  • Hiromichi Setohara, Hirokazu Kato, Kayo Kawamoto, Keihachiro Tachibana
    Type: Article
    2004 Volume 9 Issue 4 Pages 387-395
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    In this paper, we propose a simple solution of the occlusion problem in Augmented Reality(AR). In a desktop AR system, virtual objects are sometimes drawn on a user's hand even if the hand is closer to the user than the virtual objects. In interactive applications, this becomes a problem because the users cannot view their own hands during the interaction. Our method simply compares the input image with a pre-stored marker image and extracts the hand regions. We also implemented an interaction method by using the result of hand extraction. Experimental results show that this interaction method is more natural than the traditional GUI method in a desktop AR environment.
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  • Nobuhiko Yoshii, Takahiro Wada, Kazuyoshi Tsukamoto, Satoshi Tanaka
    Type: Article
    2004 Volume 9 Issue 4 Pages 397-404
    Published: December 31, 2004
    Released: February 01, 2017
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    Appropriate exercises are important to maintain the health. In this paper, we develop the virtual reality snowboard system for whole body exercise and rehabilitation. Users can continue exercises pleasantly since the virtual reality snowboard system has amusement. In addition, we propose a methodology to provide the appropriate exercise corresponding to the personal condition by using the proposed virtual snowboard system. In the training, the longitudinal and lateral distances of sets of the flags and torque exerted on the board are controlled based on the user's conditions. Finally, we will show the effectiveness of our proposed method by measuring the heart rates, oxygen uptake and EMG signal of upper and lower limbs. It is shown that the exercise strength is enough for the training and the strength can be controlled by changing the positions of flags and torque by measuring the heart rates, oxygen uptake and EMG signals of upper and lower limbs while playing snowboard.
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  • Naoyuki Bando, Hironao Yamada, Koji Nakano, Takayoshi Muto
    Type: Article
    2004 Volume 9 Issue 4 Pages 405-412
    Published: December 31, 2004
    Released: February 01, 2017
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    In this study we developed a wheelchair simulator, which has visual presentation, force feedback and reproduction of motion, using virtual reality technology. The position and attitude of the wheelchair are presented to the operator as the motion of a six-axis motion base. Through a head-mounted display, a computer graphics system provides the operator with scenery that changes in accordance with the wheelchair's operation. We evaluated, firstly, relation between human's consciousness and feeling when force feedback and reproduction of motion were presented. Consequently, it was clarified that sense of force feedback and reproduction of motion complement each other. Moreover, we evaluated the performance of the simulator, which simulates the movement of wheelchair based on the mathematical equation. As the results, the simulator proved adequate quality for presentation of the feeling.
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  • Masahiro Fujimoto, Masataka Imura, Yoshihiro Yasumuro, Yoshitsugu Mana ...
    Type: Article
    2004 Volume 9 Issue 4 Pages 413-422
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    As personal computers and their peripheral units become smaller and lighter, portable user interfaces, such as portable keyboards, are also required. Although a number of devices have been proposed, thus far the devices have been difficult to use because of restricted functionality or the requirement for special operational methods. This paper presents the "AirGrabber", a virtual keyboard suitable for wearable computers, by which a user can enter characters by "typing" in the air on a virtual keyboard. The AirGrabber detects keystrokes by monitoring the motions of the fingers and hand through a miniature camera and a tilt sensor on the user's wrist.
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  • Ken'ichi Koyanagi, Junji Furusho
    Type: Article
    2004 Volume 9 Issue 4 Pages 423-429
    Published: December 31, 2004
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    We have proposed a passive type force display system with ER brakes. The passive type force display is essentially safe, since it has no risk of overdrive. Because of its safety, many applications, such as training, clinical applications and amusement use are expected. However, to interact with or manipulate virtual objects, such as tracing over surfaces of the objects, unique control strategies are required. In this study, we present three kinds of control algorithm to display a virtual wall, and compare their characteristics experimentally.
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  • Type: Appendix
    2004 Volume 9 Issue 4 Pages 431-
    Published: December 31, 2004
    Released: February 01, 2017
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  • Type: Cover
    2004 Volume 9 Issue 4 Pages Cover2-
    Published: December 31, 2004
    Released: February 01, 2017
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    Download PDF (730K)
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