Browsing by Author "Narumi, Takuji"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Controlling the Distribution of Salty Taste Intensity on the Tongue Using Extraoral Galvanic Taste Stimulation
    (The Eurographics Association, 2023) Tanaka, So; Narumi, Takuji; Amemiya, Tomohiro; Kuzuoka, Hideaki; Aoyama, Kazuma; Abey Campbell; Claudia Krogmeier; Gareth Young
    Galvanic taste stimulation (GTS) alters taste intensity by applying a weak electric current around the oral cavity. Previous studies on GTS have captured the overall trend of taste changes in the oral cavity produced by GTS. However, it is not well known whether the potentiating or inhibitory effects of GTS result in a spatial gradient of taste perception in the oral cavity. Therefore, in this study, we examined the possibility of spatially selective modulation of taste intensity produced in the oral cavity by GTS. The results suggested that it is possible to present the intensity gradient of the perceived taste in the frontback and left-right directions, depending on the arrangement of the electrodes. These results are expected to contribute to the presentation of taste changes that are close to the actual eating and drinking experience, and to the provision of a new taste experience in which the taste is perceived as it moves through the oral cavity.
  • Thumbnail Image
    Item
    Error Correction in Redirection: Rotational Manipulation for Natural Walking and Control of Walking Paths
    (The Eurographics Association, 2018) Mizutani, Junya; Matsumoto, Keigo; Nagao, Ryohei; Narumi, Takuji; Tanikawa, Tomohiro; Hirose, Michitaka; Bruder, Gerd and Yoshimoto, Shunsuke and Cobb, Sue
    This study proposes a novel rotational manipulation method for redirection when users attempt to turn around a corner within a virtual environment. The basic manipulation of conventional redirection can be classified into translational, rotational, and curvature manipulations. In conventional rotational manipulation, users must stop and rotate. However, this behavior is not natural in everyday walking. In addition, because the manipulated rotation varies depending on the amount of the user's rotation, this manipulated rotation could differ from the assumed rotation if the user does not rotate by the assumed angle during this manipulation. Correspondingly, the actual walking path may deviate from the planned path. Misalignment of the walking path may cause a deviation in the interaction with an object in real space, thus resulting in collision with real-space objects and other users. We devised a basic manipulation of redirection and formulated a novel method for manipulating the amount of rotation when users rotate while moving. Using this method, we changed the axis of rotational manipulation for preventing mismatches between real and virtual environments, and set an area to correct the error in rotational manipulation. The results of our experiments demonstrated that it is possible to control the walking paths and manipulate the amount of rotation during movement without changing the amount of rotation perceived by users, and without increasing discomfort. The results demonstrated that our method is useful for manipulating the viewpoint when a user walks naturally.
  • Thumbnail Image
    Item
    FrictGAN: Frictional Signal Generation from Fabric Texture Images using Generative Adversarial Network
    (The Eurographics Association, 2020) Cai, Shaoyu; Ban, Yuki; Narumi, Takuji; Zhu, Kening; Argelaguet, Ferran and McMahan, Ryan and Sugimoto, Maki
    The electrostatic tactile display could render the tactile feeling of different haptic texture surfaces by generating the frictional force through voltage modulation when a finger is sliding on the display surface. However, it is challenging to prepare and fine-tune the appropriate frictional signals for haptic design and texture simulation. We present FrictGAN, a deep-learningbased framework to synthesize frictional signals for electrostatic tactile displays from fabric texture images. Leveraging GANs (Generative Adversarial Networks), FrictGAN could generate the displacement-series data of frictional coefficients for the electrostatic tactile display to simulate the tactile feedback of fabric material. Our preliminary experimental results showed that FrictGAN could achieve considerable performance on frictional signal generation based on the input images of fabric textures.
  • Thumbnail Image
    Item
    Influence of Pseudo-haptic Weight on Product Rarity Valuation
    (The Eurographics Association, 2023) Okura, Naoya; Oyanagi, Akemi; Narumi, Takuji; Kuzuoka, Hideaki; Amemiya, Tomohiro; Abey Campbell; Claudia Krogmeier; Gareth Young
    There has been an increasing number of online shopping services that employ VR technologies so that they give customers more realistic experiences and amplify purchase intention. Meanwhile, it is known that the actual product's weight perception affects its valuation. However, verification of this phenomenon in virtual environments has rarely been reported. This study investigated the influence of weight perception generated by pseudo-haptics on product rarity valuation and purchase intention in virtual environments. The results suggest that, although individual and product differences were observed, the overall trend was that product rarity valuation was higher when the user's perceived weight was heavier than when the perceived weight was lighter.
  • Thumbnail Image
    Item
    Visuo-Haptic Redirected Walking Using Handrail
    (The Eurographics Association, 2018) Matsumoto, Keigo; Narumi, Takuji; Yanase, Yohei; Ban, Yuki; Tanikawa, Tomohiro; Hirose, Michitaka; Huang, Tony and Otsuki, Mai and Servières, Myriam and Dey, Arindam and Sugiura, Yuta and Banakou, Domna and Michael-Grigoriou, Despina
    A novel use of virtual reality (VR) was demonstrated. It enables a user to feel walking a straight virtual corridor while touching straight handrails, although the user walks while gripping circular handrails within a limited space. The main contribution of this study is to show that visual-haptic redirect walking is possible using handrails for a haptic presentation. Matsumoto et al. introduced visuo-haptic redirected walking. They used walls as a haptic presentation, and they produced Unlimited Corridor as a VR demonstration using visuo-haptic redirected walking. However, it has not yet been verified whether the same effect can occur by touching other shapes. Therefore, in this study, a VR demonstration using handrails instead of walls was created, and whether visuo-haptic redirected walking is possible even with handrails for haptic presentation was examined. In the demonstration, more than 2000 people participated, and their comments and motion data were gathered. The users' comments implied that visuo-haptic redirected walking was possible using handrails.
  • Thumbnail Image
    Item
    Wider IPD Makes People Perceive Their Body to be not so Large when Large Hands are Presented
    (The Eurographics Association, 2019) Mine, Daisuke; Ogawa, Nami; Narumi, Takuji; Yokosawa, Kazuhiko; Kakehi, Yasuaki and Hiyama, Atsushi
    It is known that hand size and the interpupillary distance (IPD), as well as eye height from the ground, are some of the determinants of body size. We investigated the effect of simultaneous changes in hand size and IPD on size perception regarding the body and the external world in virtual reality. We manipulated the hand size and the IPD (normal hand and normal IPD, large hand and normal IPD, large hand and large IPD) while vertically increasing the participants' eye height. Our main results indicated that a wider IPD combined with larger hands made participants perceive their body to be smaller than when the IPD was normal. Thus, the IPD influences the perception of body size when large hands are presented. This is a novel result because it suggests the probability of an interaction effect between the IPD and the hand size, or between the IPD and the presence of hands, on body size perception.