검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 9

        1.
        2022.11 구독 인증기관·개인회원 무료
        The purpose of this study is to develop a pH measurement system capable of measuring the acidity of saliva to check the change in pH level in saliva during driving and to detect whether fatigue is affected. When the pH level is checked at rest and operation, and oxygen concentration is supplied additionally, it will be verified whether the fatigue is reduced. It is reported that the pH level in saliva is divided into stages from 0 to 14, and the lower the value based on step 7, the higher the fatigue, and the lower the fatigue. In particular, in enclosed vehicles, drowsiness and fatigue due to increased carbon dioxide have increased, leading to a major cause of traffic accidents. Therefore, fatigue may be detected in advance by analyzing fatigue through a change in pH level by supplying oxygen during operation. The electromotive force generated by the existing itself is a level of several mV to develop a pH measurement system, so it is developed by expanding it to a range that can be measured using a readout circuit. In the experiment, 13 male experimenters in their 20s measured pH levels in resting and driving conditions. After 20 minutes of rest, the process of inhaling oxygen for 20 minutes was repeated three times. The oxygen concentration used in the experiment was 21% oxygen and 30% oxygen concentration in the atmospheric state, and in the oxygen supply method, a triangular flask was directly connected to the subject’s nose and then oxygen was supplied. As a result of collecting and analyzing saliva after rest and operation, it was confirmed that the pH level tended to decrease in the operating state. In addition, as a result of increasing the pH level when the oxygen concentration is 30% more than 21%, it is confirmed that fatigue tends to decrease as the oxygen concentration increases. Therefore, it was possible to confirm a significant change in fatigue by analyzing the pH level of saliva through this pH measurement system. This study can be used as a fatigue test in various environments through simple pH measurement.
        2.
        2022.11 구독 인증기관·개인회원 무료
        The The purpose of this study is to establish evaluation criteria for the purchase of electric vehicles and to present an evaluation model using quantitative scales for evaluation factors. This study was limited to the study of purchasing factors related to electric vehicles, and the spatial scope was limited to potential buyers in their 20s to 50s living in the Daejeon area. Based on the survey, the factors affecting the purchase factors (energy economics, image, performance, maintenance, price) were examined using the AHP method, and the priorities were analyzed to determine how much influence these factors have on the purchase of electric vehicles. In addition, in order to verify the logical consistency of the survey items, a consistency ratio test (c) was conducted. Through this study, priority considerations for the purchase of electric vehicles were presented, and information on future consumer interest in electric vehicles was conducted. It is judged to be able to provide an opportunity to provide various services for each layer.
        7.
        1987.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is carried out to compare the quality of sesamin oil using to 52 restaurants in city with that of pure sesamin oil. The pure sesamin, corn soybean and perilla oils used reference oil commodities of famous corporations. The fatty acid, sesamin and sterols of reference and restaurant oils are analyzed by gas chromatography. The results are as follows; 1. A pure sesamin oil can be identified with the component and content of fatty acid, sterol and sesamin. 2. In 52 restaurant oils, 12 oils (23%) are estimated as pure sesamin oil and the remainders (77%) are mixed with corn oil, soybean oil an perilla oil. 3. The sesamin oil that is mixed with corn oil is 35%, soybean oil is 17% and perilla oil is 15%.
        4,000원
        8.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Numerical analysis using commercial CFD code was carried out to develop the drag force type vertical axis hydraulic turbine for the improvement of the production efficiency of small hydro energy at low flow velocity condition. Blade pressure changes and internal flows were analyzed according to the presence or absence of the hydraulic turbine blade holes at flow velocity of less than 1.0~3.0 m/s. According to the numerical results, the pressure and flow velocity is severly affected by the flow velocity in turbine blade with no holes, while the influence of flow velocity is comparatively decreased in turbine blade with holes. It is also found that the pressure and flow velocity on the blade surface with holes are evenly distributed with no singular location and it is believed that forming a hole in the blade may be helpful in terms of structural safety.