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Okazaki, Japan

Kawakita E.,Aichi Prefectural University | Itoh M.,TOKAI RIKA Co | Oguri K.,Aichi Prefectural University
IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC | Year: 2010

Most of the traffic accidents have been caused by driver's inattention. Therefore, driver monitoring is one of the most important challenges in order to prevent traffic accidents. Some studies for evaluating mental workload during driving have been reported; however driver's mental state should be estimated quantitatively for the future. This paper proposes an estimation method of driver's mental workload using physiological information. We defined mental workload as NASA-TLX score, and used the multiple linear regression to quantify driver's mental workload. As a result, higher accuracy was achieved by considering driver's aggression. ©2010 IEEE.

Inoue T.,Nagoya University | Sugawara Y.,Daihatsu Motor Co. | Sugiyama M.,TOKAI RIKA Co
Journal of Applied Mechanics, Transactions ASME | Year: 2010

Active magnetic bearing (AMB) becomes widely used in various kinds of rotating machinery. However, as the magnetic force is nonlinear, nonlinear phenomena may occur when the rotating speed becomes high and delays of electric current or magnetic flux in the AMB relatively increase. In this paper, the magnetic force in the AMB is modeled by considering both the second-order delay of the electric current and the first-order delay of the magnetic flux. The magnetic flux in the AMB is represented by a power series function of the electric current and shaft displacement, and its appropriate representation for AMB is discussed. Furthermore, by using them, the nonlinear theoretical analysis of the rigid rotor system supported by the AMB is demonstrated. The effects of the delays and other AMB parameters on the nonlinear phenomena are clarified theoretically, and they are confirmed experimentally. Copyright © 2010 by ASME.

Ohmura R.,Toyohashi University of Technology | Kusano Y.,ShinMaywa Soft Technologies Ltd | Suzuki Y.,TOKAI RIKA Co
HAI 2014 - Proceedings of the 2nd International Conference on Human-Agent Interaction | Year: 2014

A pointing gesture has an important role in human-human interaction. From our observation, we predict a pointing target before finishing the gesture in human-human communication. This paper, thus, proposes a method for a robot to predict human pointing gesture using the minimum-jerk model. Analytically, the final position of a wrist can be obtained by detecting the first acceleration peak, which corresponds to first 21% of the entire gesture. We implemented and evaluated the method with a desktop size robot named Robovie-W. The result showed that our method improves naturalness and smoothness.

Koide T.,Yamagata University | Ito M.,TOKAI RIKA Co | Kawai T.,Yamagata University | Matsushima Y.,Yamagata University
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2013

In this work, the availability of calcium phosphates for the light emitting layer of a thin-film electroluminescent (TFEL) device was investigated. The goal of this work was to develop an electronic device with ordinary materials such as a calcium phosphate, the principal ingredient of the skeleton of the vertebrate. Compositions of 2CaO·P2O5 (Ca 2P2O7), 3CaO·P2O5 (Ca3(PO4)2) and 4CaO·P2O 5 (Ca4O(PO4)2) were examined as the candidates for the light emitting layer. Before composing the TFEL device, the photoluminescence (PL) properties of the three compositions were investigated in the powder form to evaluate the performance as the light emitting layer. Among the examined calcium phosphates, Eu-doped β-Ca3(PO 4)2 showed the best PL properties. It showed typical red-emission from Eu3+. The PL intensity was enhanced with the heat-treatment temperature and the optimal temperature was 1250 °C. Then, a TFEL device was prepared by a spray pyrolysis method with the β-Ca 3(PO4)2:Eu3+ phosphor layer on a BaTiO3 disk. The TFEL device exhibited the red emission originating in Eu3+ at 610 nm under applying alternating voltage. Different from the power sample, the intensity of EL decreased with the heat-treatment temperature from 1000 to 1250 °C. The deterioration of EL at the higher temperatures was attributed to chemical interaction between the phosphor layer and the BaTiO3 disk. © 2012 Elsevier B.V. All rights reserved.

Nakajima M.,Toyota National College of Technology | Uematsu Y.,Gifu University | Kakiuchi T.,Gifu University | Akita M.,Gifu University | And 2 more authors.
Zairyo/Journal of the Society of Materials Science, Japan | Year: 2011

The effects of the strain-induced martensitic transformation on the fatigue behavior of type 304 stainless steel were studied. Rotating bending fatigue tests have been performed in laboratory air and in 3%NaCl solution using specimens subjected to tensile-prestrains at ambient temperature and -25°. Martensitic transformation occurred more remarkably at -25° than at ambient temperature. In laboratory air, the fatigue strengths of the prestrained specimens increased with increasing prestrain and the specimens subjected to the same prestrains at each temperature exhibited similar fatigue strength in spite of the different amount of martensitic phase. This indicated that the increase in fatigue strength of the prestrained specimens was primarily attributed to work hardening. In 3%NaCl solution, the fatigue strengths of the prestrained specimens at -25° decreased significantly compared with those in laboratory air. EBSD analysis revealed that the strain-induced martensitic transformation took place within slip bands and corrosion pits were observed at the crack initiation site in the large prestrained specimens. Based on these results, it was confirmed that the strain-induced martensitic transformation exerted large influence on the fatigue behavior in 3%NaCl solution. © 2011 The Society of Materials Science, Japan.

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