Studies in Science and Technology
Online ISSN : 2187-1590
Print ISSN : 2186-4942
ISSN-L : 2187-1590
Current issue
Displaying 1-12 of 12 articles from this issue
Preface
Feature Article
Original Article
  • Yuki Saito, Ryoji Onodera, Michiaki Shishido
    2022 Volume 11 Issue 1 Pages 17-22
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    Recently, the birthrate declines and the population ages, the number of people require nursing care and the burden on nursing care workers has been increasing. One of the attempts to support the independence and improve the quality of life of those who need care is the application of Brain-Computer Interface (BCI). BCI system was developed by us specialized for serial operation, based on EEG signals of concentration and relaxation states. In the previous study, a new system was constructed which introducing a new motor control method that introduces a new evaluation compartment concept defined as gate time in the processing of sampled EEG signals to reduce the time delay that was a problem with the conventional system. In this study, we verified the optimal threshold in the new system in order to further improve the response. Consequently, the success rate of task was as high as more than 68 % at the threshold of 40 and 50, which is an improvement of about 10 % compared to the conventional system. Furthermore, the Friedman’s test was indicating a significant difference in the success rate of task in each threshold, and the paired t-test was indicating a significant difference in the success rate of task in threshold 40 and 50. This can be concluded that the task success rate of task is significantly improved at threshold 40 and 50, and voluntary motor control is possible. The malfunction rate ranged from 21 to 31 % regardless of the threshold, and no significant difference was observed in Friedman’s test. On the other hand, the percentage of malfunction by stop increased as the threshold value increased. In addition, the subjects who successfully drove the motor at the threshold of 60 and 70 had their brains in a state of extreme concentration, and the motor continued to drive during the task section, and it took time to stop the motor even after the transition to the rest section. Since it is essential to ensure safety and to control equipment according to the user’s intentions in order to promote the use of BCI which enabled stable control of motor drive and stop, can be said to be the optimal threshold was 40 and 50.
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  • Hiroyuki Noda
    2022 Volume 11 Issue 1 Pages 23-28
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    The taste of sake was examined using a Brix meter, an acidity meter, and a taste sensor. One hundred domestic sake samples were used as samples. The taste values were measured using a taste sensor to determine the five first tastes (acidity, saltiness, umami, miscellaneous bitterness, and pungent astringency) and the three after tastes (umami richness, bitterness, and astringency). After analysing the respective taste data, the Brix value (sweetness and dryness), the acidity value (dryness), and the umami richness value (umami) were considered suitable as taste indicators for sake. Using these three indices, cluster analysis classified the sake into eight clusters; based on the values of each of the eight clusters, clusters 2 and 3 were judged as sweet based on the definition of sweetness and dryness by Brix value, while all other clusters were judged as dry. Light and rich was also evaluated comprehensively using acidity values ranging from +4 to –2 (positive for strong acidity) and umami richness values ranging from +3 to –1 (negative for strong umami). Based on the taste classification using acidity and sake degree, dry and positive values were classified as light dry, while negative values were classified as rich dry. If the taste was sweet and positive, it was classified as rich sweet; if negative, it was classified as light sweet. As a result, there was no extreme concentration of rich dry compared to the classification by acidity and sake degree. These results suggest that the use of Brix value, acidity value, and umami richness value as taste indices can be used to classify sake into four general tastes, and that it may be possible to distinguish differences in taste better than classification by acidity and sake degree.
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  • Reiko Furoi , Noriyuki Kida , Atsushi Yokoyama
    2022 Volume 11 Issue 1 Pages 29-35
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    Cedar wooden-shingle boards, a traditional Japanese roofing material, are handmade by craftsmen using traditional techniques. Product selection is left primarily to the roofers, whose selection criteria are visual and not quantified. In this report, semi-structured interviews were conducted with the roofers in order to clarify the points that the roofers pay attention to when selecting the boards. The comments were analyzed using text mining techniques to classify the view point and evaluation criteria. From all the comments, 622 segments on the basis of meaning unit were extracted for analysis and further aggregated into 18 categories. The results showed that the focus of the roofers was “shape” (77.3 %) and “material color” (22.7 %) of the boards, indicating a relatively high level of attention to the “shape”. In addition, “koguchi” was mentioned relatively more frequently in the part of the boards that surfaces after construction, and this tendency was confirmed across both “shape” and “material color” categories. And as for the width of the cedar wooden-shingle boards, negative evaluations increased when the width exceeded 125 mm. It can be inferred that the roofers suggested the ideal width of the boards considering the characteristics of the cedar tree species. This survey suggests that narrower board widths may be available when the species is limited to cedar. This means that the boards can be produced from cedars of a younger age than the standard theory, which may contribute to the effective use of forest resources and lower prices for the boards.
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  • Teruo Yokoyama
    2022 Volume 11 Issue 1 Pages 37-41
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    The role of science in society is changing recently, and scientists are expected to engage in social problems. Therefore, the social responsibility of scientist needs to be revised. Philosophers of science deal with problems concerning science and value, and cognitive value and social value should be distinguished. Cognitive value in science is discussed by Kuhn and Laudan. Considering STS scholar’s arguments about post-normal science by Ravetz and the third wave of science studies by Collins, different types of science must be distinguished. In the case of science policy-decision making, non-experts participate in the process. But since science is based on tacit knowledge, the role of layman is limited.
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Research Letter
  • Yuji Ogihara
    2022 Volume 11 Issue 1 Pages 43-46
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    To conduct empirical research on names and naming, it is necessary to do analyses and have discussions based on evidence, not intuition and impression, which requires reliable data on names. In Japan, the “Tamahiyo Rankings of Baby Names,” which has continuously conducted large-scale yearly surveys between 2005 and 2021, plays a crucial role. However, the surveys changed its methods in 2019 and those changes have not been mentioned on its website. Changes in the survey methods should be precisely understood particularly when analyzing temporal changes in names and naming to distinguish essential changes from by-products of methodological changes. Therefore, this article explains the changes in the survey methods of the “Tamahiyo Rankings of Baby Names”. The surveys between 2019 and 2021 collected data from a broader layer of participants than those between 2005 and 2018, which remarkably increased the sample sizes of the surveys between 2019 and 2021. Moreover, the surveys between 2019 and 2021 displayed a narrower range of results and discussed names based on rationales independent of survey data, making it difficult to conduct quantitative analyses for this period. This information will be helpful when analyzing the “Tamahiyo Rankings of Baby Names” and discussing names and naming.
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  • Oxidative cyclization reaction with DDQ and Darco KB®
    Kazuyuki Umemura, Takaharu Aoyama, Kohare Takeuchi , Taiga Takahagi, T ...
    2022 Volume 11 Issue 1 Pages 47-51
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    UK-1 and AJI9561 are cytotoxins isolated from Streptomyces sp. Its structure is characteristic of two benzoxazole skeletons, and has been reported to be active in cancer cells such as mouse cell line B16, mouse leukemia cell P388, and human uterine cancer cell HeLa. This paper describes the effective total synthesis of UK-1, AJI9561 using DDQ (2,3-Dichloro-5,6-dicyanobenzoquinoe) or active carbon (Darco KB®), following the first report of synthesis via N-acyl derivatives. In the method via the N-acyl derivative, the yield of benzoxazole synthesis from the condensation reaction of the trisubstituted benzene derivative accompanying the synthesis of AJI9561 was as low as about 23 %. On the other hand, the synthetic yield of the corresponding benzoxazole was significantly improved to 60 % or more by using DDQ or Darco KB®. As a result, with this improved method, the synthesis process was shortened, and total synthesis yield of AJI9561 from 8 steps 11% for the N-acyllation method to 6 steps 30 % for the DDQ or Darco KB® method.
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  • Susumu Nakayama
    2022 Volume 11 Issue 1 Pages 53-58
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    Two types of solid-state electrochemical cells were designed and their CO2 gas-sensing characteristics were compared. One was a heterojunction-type sensor, whereas the other was a conventional homojunction-type sensor. A potassium ionic conductor was used as the solid electrolyte and lithium carbonate (Li2CO3) or potassium carbonate (K2CO3) were used as the sensing electrodes. The electromotive force (EMF) of the cell, having Li2CO3 as the electrode (heterojunction-type sensor), increased linearly with an increase in the partial pressure of CO2 gas. Similar behavior was observed in the cell using the K2CO3 electrode (homojunction-type sensor). The slopes of Nernst’s equation suggest that the two-electron reduction associated with the carbon dioxide molecules occurs on the sensing electrode. The EMF of the heterojunction-type sensor showed excellent performance, and the 90% EMF response time of this sensor at 450 °C was only a few minutes on changing the carbon dioxide partial pressure.
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  • Normal mode and reverse mode
    Seiji Ujiie, Ayaka Sannomiya, Junichi Baba
    2022 Volume 11 Issue 1 Pages 59-62
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    The structures of polymer networks in light control liquid crystal composite films (LCLCFs) were examined by Scanning Electron Microscope (SEM) observation. Normal mode and reverse mode LCLCFs were used for this research. Samples of the contact surface of the LCLCFs with the electrode substrate and its cross section were prepared. SEM images of the surface and cross-section of the normal mode LCLCFs showed that the liquid crystal material is uniformly dispersed within the polymer network. On the other hand, the liquid crystalline material in the reverse mode LCLCFs with a perpendicular alignment was mostly located near the electrode film, and the layer of polymer network was located in the middle region of the LCLCF. In other words, the reverse mode LCLCFs had a structure in which a polymer network-liquid crystal layer, a polymer layer, and a polymer network-liquid crystal layer are laminated. This difference is caused by the interaction between the electrode substrate surface and the polymer network obtained by the photo radical polymerization. In the reverse mode LCLCFs, the amount of polymer network adhered to the electrode substrate is smaller than in the normal mode LCLCFs. Therefore, the adhesion between the reverse mode LCLCFs and the electrode substrate is weaker when compared to the normal mode LCLCFs.
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  • Shogo Nakagawa, Seiji Ujiie, Masanori Nata
    2022 Volume 11 Issue 1 Pages 63-66
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    Liquid crystalline polyurethanes (LCPUs), having azobenzene mesogenic groups, formed a nematic phase on heating and cooling processes. Liquid crystalline binary mixtures were obtained by mixing LCPUs and strongly polar compounds with mesogenic groups. The liquid crystalline binary mixtures exhibited an induced smectic A phase on heating and cooling processes. LCPUs exhibited a schlieren texture in the nematic phase. In the smectic A phase of the liquid crystalline binary mixtures, however, a fan texture was formed. The X-ray diffraction patterns of the liquid crystalline binary mixtures were composed of the sharp inner and the broad outer reflections. The X-ray inner reflections correspond to the layer spacing of the smectic A phase. On the other hand, the X-ray broad outer reflections reveal the existence in a short-range order within the layer. Mixing of weakly polar compounds with LCPUs was also examined. The weakly polar compounds did not mix well with LCPUs, and their liquid crystalline binary mixtures did not induce a smectic A phase. The interaction between the azobenzene mesogenic group and the strongly polar compound can lead to the control of oriented structures of LCPUs.
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Technical Report
  • Yuya Minatoya, Yudai Kitagawa, Shinichi Funase, Toshihiko Shimauchi, H ...
    2022 Volume 11 Issue 1 Pages 67-77
    Published: 2022
    Released on J-STAGE: June 28, 2022
    JOURNAL OPEN ACCESS
    Existing display systems are sometimes insufficient to display the information to be conveyed. For example, a room temperature meter displays the room temperature as a bar graph or numerical value, but the sensible temperature differs depending on the season: the same 20 degrees centigrade can be cold in summer but warm in winter. Additionally, elderly people may have a dull sense of temperature and hence not notice the room temperature even if the change is significant. A display system showing not only the temperature but also the four seasons in the year, level of comfort and color code for danger (red: dangerous, yellow: caution, green: safe) can be easier for users to understand. However, displaying various information simultaneously can overburden the users since it requires intensive and swift processing of incoming information. To address these problems, this paper considers a display system with facial expressions: information to be displayed are translated to part and condition of the face to construct a face chart. The shape, size, position, color or movement of the chart are determined by the information. Morphological visual data transmission is superior in speed, recognizability, accuracy and multiple data transmissions. For human beings, faces are the most significant clue for identifying others. Facial expressions are mainly expressed by the muscles around the eyes. Eyes often shows the emotional state of the person. This paper aims to evaluate the effect of the display system using the features of facial expression. We first examine the accuracy of facial expressions of taste and emotion and their recognition by conducting questionnaire experiments. In the next step, we evaluate the ability of facial expression in simultaneous information transmission and its impact to observers. Finally, we propose an indoor environment display system using face expression as its application. Main results are as follows: as for taste, sweetness (76.5 %) and acidity (72.8 %) had high recognition rates; as for emotion, joy (96.3 %) and surprise (76.5 %) had high recognition rates; taste and joy matching experiments showed high matching rate between sweetness and joy (94.3 %); an experiment to evaluate a Japanese sweetshop showed sufficient simultaneous information transmission result (74.8 %); an experiment for time indication showed the facial expression method had the highest impact ability. These results show the effectiveness of facial expression system.
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