Transactions of the Virtual Reality Society of Japan
Online ISSN : 2423-9593
Print ISSN : 1344-011X
ISSN-L : 1344-011X
Volume 8 , Issue 1
Showing 1-20 articles out of 20 articles from the selected issue
  • Type: Cover
    2003 Volume 8 Issue 1 Pages Cover1-
    Published: March 31, 2003
    Released: February 01, 2017
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  • Type: Index
    2003 Volume 8 Issue 1 Pages Toc1-
    Published: March 31, 2003
    Released: February 01, 2017
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  • Type: Index
    2003 Volume 8 Issue 1 Pages Toc2-
    Published: March 31, 2003
    Released: February 01, 2017
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  • Michitaka Hirose, Koichi Hirota
    Type: Article
    2003 Volume 8 Issue 1 Pages 1-
    Published: March 31, 2003
    Released: February 01, 2017
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  • Toshiyuki Miyata, Kinya Fujita
    Type: Article
    2003 Volume 8 Issue 1 Pages 3-9
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    Force display devices are frequently utilized for the elasticity display, in order to control the relationship between the user's fingertip position and the contact force. Remote sharing of the elastic sense between two users has a difficulty in realization, because the transmittance of position induces additional force for position control, and this inessential force is perceived by the remote users as additional reaction force. In this study, a passive sharing method of elastic sense between two remote users is proposed by transmitting the computer generated images and fingertip reaction force. A series ofpsychophysical experiments demonstrated that 1) the users can discriminate the correct elasticity with 60 to 80 percent accuracy among 4 different elasticity in paired comparison experiment; 2) the users can answer the transmitted elasticity in adj ustment experiment.
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  • Takashi SHIMOJI, Kinya FUJITA
    Type: Article
    2003 Volume 8 Issue 1 Pages 11-18
    Published: March 31, 2003
    Released: February 01, 2017
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    Realization of walk-through in shared-virtual environment over Internet is expected to be utilized in at-home rehabilitation or multi-user amusement system. This study proposes a system for multi-user walk-through system using client/server system and locomotion interface using walk-in-real-place "WARP". The position error, angle error and curvature of avatar trajectory were evaluated at various communication intervals. It was demonstrated that the smooth and accurate avatar animation of remote user in shared virtual space was attained by the developed system.
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  • Atsushi Shinjo, Shigeki Yoshida
    Type: Article
    2003 Volume 8 Issue 1 Pages 19-25
    Published: March 31, 2003
    Released: February 01, 2017
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    Recently, wearable computer for rescue party is expected for improving their rescue ability such as lifesaving in disaster. In this case, one of the most important factors of effective and efficient rescue activity are certain and real-time sharing of disaster information between rescue party and the center of disaster mitigation. However, in most cases, the narrow-band and unstable network connection that is supplied by the mobile communication devices is used for the connection method of wearable computer as default. As a result, it has been said that use of a wearable computer is not so good for a rescue party. For dissolving this problem, we apply the data transmission methodology that has the feature in dealing with the narrow-band and unstable network. In this experience, we use the two kinds of algorithm for this methodology, and compared these with the normal transmission methodology in the narrow-band network. In this experiment, the normal system stopped the transmission soon. One algorithm could not cope with the sudden change of band width. The other algorithm could transmit the whole data in real-time.
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  • Yuji KURITA, Kazuo KUNIEDA
    Type: Article
    2003 Volume 8 Issue 1 Pages 27-35
    Published: March 31, 2003
    Released: February 01, 2017
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    In this paper, we present 3D shape reconstruction system using multiple cameras and network transmission system for real-time use, easy construction and network familiarity. Our system is based on Shape from Silhouette method. In this case, there is a problem how to choose a camera image for each polygon's texture. So we develop a new method of camera choice algorithm using polygon's normal vector and center position of the target object. And to use under not only local but also network environment, we develop a network transmission system to save network bandwidth. We also present camera setting problem of Shape from Silhouette method. We discuss it from accuracy of reconstructed shape and texture mapping.
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  • Tetsuro Ogi, Toshio Yamada, Yuji Kurita, Yoichi Hattori, Michitaka Hir ...
    Type: Article
    2003 Volume 8 Issue 1 Pages 37-46
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    Video avatar technology has become very popular as a high presence communication tool in the shared virtual world. In order to generate a realistic video avatar, several modeling techniques, such as the 2D plate model, 2.5D surface model or 3D voxel model have been proposed. This paper discusses the features and the usage of the various video avatar techniques. The appropriate video avatar that is used in the application system should be selected according to the purpose and the system environments. In addition, we also discuss the video avatar studio and the video avatar server technologies that were developed to utilize the various video avatar methods effectively in the networked virtual environments.
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  • Koichi Hirota, Michitaka Hirose
    Type: Article
    2003 Volume 8 Issue 1 Pages 47-56
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    As broadband network spreads, it is becoming a topic of interest to implement novel communication framework that will provide more convenience than the communication through telephone and TV conferencing. Such broadband networks is advantageous to previous services in that they provide means to transmit additional information to video and audio. On the other hand, because of recent advancements of VR technologies, such as the immersive projection technology that realize high quality visual presentation, it is becoming more realistic to use the technologies for the purpose of communication. In this paper, we discuss how we will be able to support research communications using the technologies of network and VR; based on the survey of previous works on communication and networked VR, we describe our idea for the implementation of research communication environment; also will introduce the activities of Multimedia Virtual Laboratory Project that is carrying out empirical studies on supporting research communications.
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  • Takuro Kayahara, Tetsuro Ogi, Michiteru Kitazaki, Tomoya Yoshino, Mich ...
    Type: Article
    2003 Volume 8 Issue 1 Pages 57-63
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    In this study, the technologies of multimedia virtual laboratory (MVL) were applied to psychological experiment in which the view-point dependency of the scene recognition was examined. The MVL sysytem for psychological experiment was constructed with immersive projection technology (IPT), video avatar, networked database(Cyber Communication dataBASE: CCBASE) and user interface with PDA. A scene recognition experiment was carried out under networked condition with this MVL system. An experimenter was in Gifu Techno-plaza (Gifu pref.) and subjects was in University of Tokyo (Tokyo Met.). The experiment was successfully accomplished and an interesting data on scene recognition was obtained.
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  • Makoto Ando, Kazuhiro Yoshida, Tomohiro Tanikawa, Yankang Wang, Jun Ya ...
    Type: Article
    2003 Volume 8 Issue 1 Pages 65-74
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    Recently, virtual reality technology has been used in numerous practical applications. In this paper, we developed and evaluated a proto-type system of educational VR system by using networked VR technology. To build proto-type systems, we constructed high quality historical VR contents, Copan ruins of Mayan civilization, and integrate two different types of VR systems, theater-type and home-type VR systems. By using VR Theater, a teacher can give lecture on Mayan civilization to his students as if they are in the real Copan ruins. Also, we divide students into four groups and inspect the effect of mutual observation to group stydy. In proto-type system, each group walk through Copan ruins by using home-type VR systems set up in front of the VR theater, and solve historical questions about Mayan civilization. Throughout the experiments, almost all students are interested in Mayan civilization and communicate each other in both real and VR environments.
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  • Tetsuro Ogi, Takuro Kayahara, Masafumi Kato, Hiroshi Asayama, Michitak ...
    Type: Article
    2003 Volume 8 Issue 1 Pages 75-83
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper describes the high presence interactive sound field simulation method that can control virtual sound field interactively in the multi-screen immersive projection display. In this method, convolution filters, that were calculated based on the wave equation, are replaced in real-time using the multi-channel digital signal processor, and the simulated sounds are displayed using the 16-channel speaker system. In addition, compensation filters are used in order to reduce the influence of the screen attenuation. This system was applied to the video avatar communication system in the shared virtual world, and the effectiveness of this method was evaluated.
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  • Shinya Miyazaki, Masashi Yamada, Junichi Hasegawa, Takami Yasuda, Shig ...
    Type: Article
    2003 Volume 8 Issue 1 Pages 85-91
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper proposes a fast computation elastic model. It is constructed by a small number of elements. Elastic objects are constructed in various sizes of elements. Small elements are laid out on the surface and larger elements are confined to the center. A variety of element shapes and the way they fit into any voxel-based shape are presented here. It effectively reduces the number of elements, and saves computation time. This elastic element model is constructed for real-time processing, performing consistent restoration, and being applicable to any shape of polyhedron elements.
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  • Mamoru Endo, Takami Yasuda, Shigeki Yokoi, Yoshitsugu Hayashi
    Type: Article
    2003 Volume 8 Issue 1 Pages 93-101
    Published: March 31, 2003
    Released: February 01, 2017
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    As a method for city evaluation from the viewpoint of participating citizens, we propose a new method by making use of 3D images with which we are able to present a virtual city with integrated virtual human characters and use this to create a 3D drama simulation movie. In our paper, we first introduce an evaluation method of citizens' life based on the QoL method, which we further evolve into our drama simulation method by applying 3D virtual human characters. In addition to this, we discuss a concrete technique to construct a Web-based system that makes it possible for citizens to evaluate their city effectively. After constructing our system and generating the drama simulation movie, we were able to express the daily life of the citizens in 3D images, also integrating animated passer-bys and cars. On the whole, our method proves to be effective in evaluating the city based on the participation of citizens.
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  • Nobuhiko MUKAI, Masayuki HARADA, Hiroshi OYAMA
    Type: Article
    2003 Volume 8 Issue 1 Pages 103-109
    Published: March 31, 2003
    Released: February 01, 2017
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    In neurosurgery, there is a method to clip an aneurysm which proliferates at a diverging point of arteries. It is very important for surgeons to train for improving their skills with simulators based on virtual reality technology. This paper describes an artery model with an anuerysm, which model can deform in real-time. In the surgery, doctors have to handle an instrument called spatula with a hand and clip the aneurysm with another hand. Usually, with computer graphics, one of virtual reality technology, the artery model is constructed with many polygons, which take a lot of time to calculate the collision detection between the polygons of the artery and that of the instrument. In this paper, the skelton of the model is used and the collision detection is performed between the skelton of the artery and that of the instrument. This model enabled the artery model with an aneurysm to deform in real-time and us to develop the neurosurgery simulator.
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  • Kaori Segawa, Hiroyasu Ujike, Katsunori Okajima, Shinya Saida
    Type: Article
    2003 Volume 8 Issue 1 Pages 111-117
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    We examined as to whether adding distance information increases accuracy of perceived self-motion speed from radial flow. To do this, we varied richness of pictorial distance cues in the radial flow stimulus. Moreover, by presenting the stimulus in central or peripheral visual field, we analyzed the dependency of retinal region of stimulation on perceived speed of self-motion for different richness of pictorial cues. The results showed that the dependency of retinal region was decreased with increasing richness of pictorial cues. This indicates that pictorial cues increase accuracy of perceived self-motion speed. In addition, we explored the effects of the stimulus distance, and found that the dependency of retinal region was similar between different stimulus distances.
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  • Shinji Uchiyama, Hiroyuki Yamamoto, Hideyuki Tamura
    Type: Article
    2003 Volume 8 Issue 1 Pages 119-125
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    This paper describes a robust registration method for merging real and virtual worlds. This method is a hybrid approach utilizing a 6DOF sensor and a computer vision technique. Error of the 6DOF sensor is corrected by an iterative algorithm that minimizes the sum of distances between landmark positions estimated with the sensory data and their corresponding landmark positions in the captured image. The sensor measurement values are used for identifying markers and as the initial value of the iterative algorithm. By applying this method to practical mixed reality systems, we found that this method achieved robust, accurate and fast registration.
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  • Type: Appendix
    2003 Volume 8 Issue 1 Pages 127-
    Published: March 31, 2003
    Released: February 01, 2017
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  • Type: Cover
    2003 Volume 8 Issue 1 Pages Cover2-
    Published: March 31, 2003
    Released: February 01, 2017
    JOURNALS FREE ACCESS
    Download PDF (545K)
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