IEEJ Transactions on Sensors and Micromachines
Online ISSN : 1347-5525
Print ISSN : 1341-8939
ISSN-L : 1341-8939
Volume 139, Issue 3
Displaying 1-9 of 9 articles from this issue
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  • Masako Satoh, Yoshifumi Takao, Hideki Satoh
    2019Volume 139Issue 3 Pages 45-53
    Published: March 01, 2019
    Released on J-STAGE: March 01, 2019
    JOURNAL FREE ACCESS

    A nonliner function that expresses the relationship between taste sensor data and components in sake was approximated using a polynomial of Legendre functions. First, the number of components in sake was reduced using principal component analysis. Second, the number of Legendre functions of the polynomial and their degrees were selected using a genetic algorithm. Third, the coefficients of the polynomial were calculated using multiple regression analysis. The approximation error was estimated using cross-validation, and the number of Legendre functions and their degrees were optimized so as to maximize the generalization of the polynomial. As a result, sufficiently small approximation errors were obtained, and the explicit relationship between taste sensor data and components in sake was clarified using the polynomial. Furthermore, it was possible not only to confirm the taste sensor response but also to improve manufacturing processes of sake using the estimates of the variations in the taste sensor data.

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  • Saranya Yenchit, Yuta Tadokoro, Satoru Iwamori
    2019Volume 139Issue 3 Pages 54-60
    Published: March 01, 2019
    Released on J-STAGE: March 01, 2019
    JOURNAL FREE ACCESS

    We successfully developed an active oxygen species (AOS) sensor that reacts only with hydroxyl radicals and is based on pullulan, a water-soluble polymer, and methylene blue. Sterilization with AOS is necessary to use a nonwoven fabric that shields UV light. However, it is difficult to know whether AOS uniformly sterilize in the nonwoven fabric. In this study, an aluminum test box was designed, whose top was sealed with a sterile bag of nonwoven fabric. Hydroxyl-radical-sensing films and spin-trapping agents were placed inside the box, and AOS diffusion and OH* presence was investigated. Experimental results suggest that OH* was not directly generated inside the test box by UV light, in spite of the presence of the nonwoven fabric seal. The OH* present inside the test box sealed with nonwoven fabric is mostly generated either outside the test box by way of UV light irradiation or inside the box by way of ozone decomposition brought about by the reaction of this species with water.

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