著者

藤田 欣也 中楯 浩康

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.52, no.1, pp.58-62, 2014-02-10 (Released:2014-05-22)

著者

黒田 嘉宏 仲谷 正史 長谷川 晶一 藤田 欣也

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.16, no.3, pp.379-390, 2011

被引用文献数

1

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Ungrounded and light-weight force display is demanded for the daily use of a virtual reality system in a large space. The concern with a pseudo-force display, which displays limited or different physical stimuli compared with the reaction forces causing in real-world, has been growing as a solution for the last several years. This paper reports a research trend of pseudo-force displays for production of physical stimuli to fingers or a palm. We categorize the pseudo-force display according to the approach to induce similar sensation or event cognition to those in real-world. The problems derived from the features of the pseudo-force display are also discussed.

著者

藤江 律也 仲澤 悠太 徐 建鋒 小森田 賢史 内藤 整 藤田 欣也

出版者

ヒューマンインタフェース学会

雑誌

ヒューマンインタフェース学会論文誌 (ISSN:13447262)

巻号頁・発行日

vol.23, no.2, pp.135-144, 2021-05-25 (Released:2021-05-25)

参考文献数

34

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Making smart speakers proactive might benefit users by delivering unconscious but useful information. However, depending on the timing and manner of the delivery, proactive deliveries pose a risk in disturbing user’s ongoing activity. Thus, we hypothesized that the times of activity-transition are appropriate for information delivery. In this study, we prototyped a system that estimates activity-transitions based the user’s body motion using a depth camera, and actively provide Internet news through a voice of virtual character. We then conducted a set of experiments in everyday-living scenario at the homes of five university students living alone. The result demonstrated that the times after transfer are generally appropriate. In contrast, the change of the user’s face direction, i.e. supposed gaze-target transition, occurred more frequently but included more inappropriate cases. Elimination of the error-detections such as body posture change while looking at smartphone is needed to detect activity-transitions more appropriately.

著者

磯部 祐輔 藤田 欣也

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.13, no.3, pp.385-391, 2008-09-30 (Released:2017-02-01)

参考文献数

18

被引用文献数

2

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The influences of visual target and predictive visual cue on gaze behavior and cybersickness were experimentally evaluated, in order to maintain the presence and reduce the cybersickness. The severity of sickness and the sense of velocity were evaluated using simulator sickness questionnaire and method of reproduction. The eye movement was also monitored using an eye tracking camera. The results suggested that the visual target at the optical flow center has more cybersickness reduction effect than the fixed visual target, and the predictive visual cue increases the reduction effect of the target further, while the sense of velocity does not significantly differs among the visual conditions. The feasibility was suggested that presenting predictive visual cue via visual target can reduce cybersickness without impairing sense of velocity.

著者

藤田 欣也

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会誌 (ISSN:13426680)

巻号頁・発行日

vol.24, no.4, pp.4-5, 2019-12-31 (Released:2021-05-15)

参考文献数

1

著者

藤田 欣也

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.13, pp.195-204, 1996-07-25 (Released:2016-12-05)

参考文献数

20

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The feasibility of a self-organized change of stretch reflex gain caused by the passive change of the ankle joint angle was discussed in the human soleus muscles. The amount of the maximal amplitude of Hoffman (H) reflex, normalized by the maximal direct motor (M) response, was used to evaluate the excitability of the soleus motoneuron. The H reflex amplitudes in 1) normal standing, 2) ten degree dorsiflexion, 3) ten degree plantarflexion, were measured in standing posture, and also in sitting posture with the same ankle joint angles, in ten neurologically intact subjects. The normalized H-reflex amplitude was decreased from 38 percent to 32 percent by dorsiflexion and increased to 44 percent in sitting posture. The amplitude in standing posture was also decreased 41 percent to 39 percent by dorsiflexion and increased 42 percent by plantarflexion. It was suggested that the motoneuron pool is inhibited by passive dorsiflexion and facilitated by passive plantarflexion. In 24 of the 30 inhibition by dorsiflexion was indicated in sitting posture; however, only 17 indicated the inhibition in standing posture. In 25 of the 30 facilitation by plantarflexion in sitting posture was indicated; however, only 16 indicated facilitation in standing posture. The tendency of the inhibition and facilitation was obvious in the sitting posture but not clear in the standing posture. Therefore, the change of the reflex loop gain appears to have no relation to the higher center control system such as that for postural control, and seems to be a local self-organized adaptation. Two hypotheses were proposed: 1) in feedback gain compensation, the change is for compensation of the muscle spindle sensitivity change, 2) in stiffness compensation, the change is for compensation of the nonlinearity of the joint stiffness. Measurement of the response to the mechanical perturbation is required to obtain answers for these hypotheses.

著者

宮島 俊光 藤田 欣也

雑誌

第69回全国大会講演論文集

巻号頁・発行日

vol.2007, no.1, pp.77-78, 2007-03-06

著者

佐々木 博 藤田 欣也

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.5, no.1, pp.795-802, 2000-03-31 (Released:2017-02-01)

参考文献数

16

被引用文献数

6

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The cognitive rate offour levels of hardness was experimentally examined in ten normal volunteers with actual object as well as virtual object displayed by a glove-shaped force display, in order to discuss the role of visual, tactile and proprioceptive sensation in cognition of the hardness of an object. The experiment was carried out under five conditions as follows, 1 ) actual object; 2) actual object without tactile information about the object deformation; 3) actual object without proprioceptive information; 4) virtual object using a force display and 5) virtual object with visual information. The cognitive rates were 94, 82.8, 92.6, 83.6, 90.4%, respectively. The role of visual information was greater than proprioceptive information, however less than tactile information. A method to enhance the hardness display performance by alternating the visual information was proposed and its effectiveness was shown experimentally as the increase of the hardness cognition rate from 90.4 to 93.0%.

著者

大丘 達也 藤田 欣也

出版者

特定非営利活動法人 日本バーチャルリアリティ学会

雑誌

日本バーチャルリアリティ学会論文誌 (ISSN:1344011X)

巻号頁・発行日

vol.15, no.2, pp.263-272, 2010

被引用文献数

3 3

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We propose a substitutive tangential force and slip display method by controlling position of the vibrotactile phantom sensation (VPS). The tangential force is substituted by the VPS position displacement and the slip is displayed as the oscillatory displacement of the VPS position. A 20mmx20mmx20mm fingertip-wearable device with four pins has been prototyped. The evaluation experiments demonstrated the feasibility of the substitutive display of tangential force and slip, and the assistive effect in cognition of contact state change.

著者

田中 貴紘 松村 京平 藤田 欣也

出版者

The Japanese Society for Artificial Intelligence

雑誌

人工知能学会論文誌 (ISSN:13460714)

巻号頁・発行日

vol.25, no.6, pp.683-693, 2010

被引用文献数

2 2

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In this paper, we proposed the user uninterruptibility estimation method based on focused Application-Switching (AS) during PC work for establishing information display timing control scheme with less intelligent activity disturbance for users. At first, we collected and analyzed the PC operation records and the subjective uninterruptibility of users. From the analysis, we selected features in AS timing that affect user uninterruptibility. Then, we provided the estimation method based on co-occurring features that are observed in AS timing, and confirmed the availability of our method.

著者

ウィアンスィマ ポンチャイ 藤田 欣也 本多 庸悟

出版者

一般社団法人日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2005, 2005-06-09

著者

ウィアンスィマ ポンチャイ 藤田 欣也 本多 庸悟

出版者

一般社団法人日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2003, 2003

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連続な壁面の力覚提示を実現するための遭遇型力覚提示システムを試作した。手の追従に際し, 位置制御と, 接触時の力制御を円滑に切替ることにより, 小型パネルによる連続的な仮想壁面の表現を実現した。

著者

松田 穣 藤田 欣也

出版者

ヒュ-マンインタフェ-ス学会

雑誌

ヒューマンインタフェース学会研究報告集 : human interface (ISSN:13447270)

巻号頁・発行日

vol.10, no.2, pp.41-46, 2008-06-02