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        검색결과 114

        21.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 점근해석 및 논로컬 이론에서 요구하는 4차 이상의 고차 미분근사를 수행하기 위하여 계방정식에 혼합변분이론을 적용하여 MLS 차분법으로부터 구해지는 고차 미분근사의 정확도를 큰 폭으로 향상시킨다. 또한, MLS 차분법에 존재하는 세 가지 조건변수에 따른 고차미분근사의 정확도를 비교·분석한다. 혼합변분이론의 합응력을 후처리하여 변위의 미분을 근사할 경우 기존의 변위장 기반 계방정식의 차분 결과에 비해 미분 차수가 2차 낮아진다. 해석 범위내 절점 수가 과도하게 많거나 기저 차수가 클 경우 MLS 차분법의 영향영역 내에서 과적합(overfitting)이 발생한다. 또한 영향영역이 최적 범위 이상으로 넓어질 경우 근사의 정확도가 떨어진다. 위 내용을 사인 하중을 받는 단순지지보 수치예제로부터 확인하였다.
        4,000원
        25.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 다공성 보와 논로컬 매개변수 사이의 관계에 대한 유한요소해석을 수행한다. 논로컬 매개변수는 다공성 보의 결함을 표현하는 변수들로 정의하여, 하중조건 및 경계조건에 대한 수치모사를 통해 계산한다. 다공성 보와는 반대 개념의 결함을 가지는 보에 대한 해석도 수행하였다. 이러한 보들의 거동은 논로컬 매개변수의 항으로 표현하였으며, 이 매개변수는 구멍의 지름의 제곱 그리고 원기둥 지름의 세제곱에 비례하는 것을 확인하였다. 특히 작은 원기둥을 가지는 보에 축하중을 가하는 경우, 예상과는 다르게 3 차원 유한요소 해석 결과와 2차원 평면응력 해석 결과는 다름을 알 수 있었다.
        4,000원
        26.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: This is a group pretest-posttest design study that aim to examine the effect of smart problem-based learning (PBL) teaching method using flipped learning to meta-cognition, academic self-efficacy, and satisfaction level of nursing students. Method: The subjects were 76 students who took basic nursing practice, which is a major subject, from August 29 to December 13, 2018. A questionnaire was used to measure meta-cognition in web-based self-directed learning. The self-efficacy measurement used a scale consisting of self-regulating efficacy, task difficulty preference, and confidence. The measurement of practical satisfaction is a 5-point Likert scale that employs a questionnaire. Flipped learning uploaded a 10-minute lecture video, and the subjects learned through PC or smartphone. PBL teaching was developed in two modules: gavage and indwelling urinary tract. Results: Result showed a significant improvement of meta-cognition after education than before education (t=3.21, p=.043). Academic self-efficacy was not significantly changed before and after education. Practice satisfaction was significantly improved after training than before training (t=-2.19, p=.032). Conclusion: The smart PBL teaching method using flipped learning is an effective teaching and learning strategy for nursing majors. Nursing students with high meta-cognition will be able to perform well in their learning outcomes; therefore, this positive performance experience will enhance self-efficacy.
        4,200원
        27.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To increase the functional material content of soybean, a repetitive steaming and drying process was used. We investigated the changes in the total polyphenol content, the antioxidant activity, and the angiotensin-Ⅰ converting enzyme (ACE) inhibition in soybean following nine rounds of steaming and drying. Soybean was steamed 9 times for 2 h and then dried 9 times from 55℃ to 73℃ for 3 h. The total polyphenol content in the soybean reached a maximum value of 60.47 mg GAE eq./100 g at 73℃ while the total polyphenol content in the raw soybean reached 25.17 mg GAE eq./100 g. In the raw soybean samples, the DPPH radical scavenging activity (5 mg/mL) was 8.04% but it increased by 43.29% after drying 9 times to 73℃. ABTS radical scavenging activity also improved following 9 rounds of steaming and drying. ACE inhibitory activity of the soybean dried 9 times at 73℃ was 58.94% at 10 mg/mL. These results showed that steaming and drying soybean 9 times enhanced the antioxidant activity and the ACE inhibitory activity of soybean. Therefore, more research on the biological and anti-hypertensive activity of soybean using this steaming and drying method is necessary.
        4,000원
        28.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to examine biological activities, including total contents of polyphenol, antioxidant activities, inhibitory activities of tyrosinase, and protective effect against oxidative stress in the HepG2 cells of ethanol extracts from wheat sprout. The antioxidant activity of extracts was determined by ABTS and DPPH radical scavenging activities. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, 80% and 95%, respectively). The highest amount of total polyphenol was extracted by 50% and 80% ethanol which was 26.3 and 26.8 mg gallic acid equivalents/g sample, respectively. High levels of ABTS and DPPH radical scavenging activity were found in 50% ethanol (26.7 and 15.0 mg TEAC/g sample, respectively) and 80% (24.3 and 16.1 mg TEAC/g sample, respectively) ethanol extracts. Also, 50% and 80% ethanol extracts indicated higher inhibitory activities of tyrosinase compared with other extracts. In the cell-based assay, pre-treatment of the HepG2 cells with wheat sprout extracts prevented the cell damage induced by TBHP (tert-butyl hydroperoxide). The results of this study indicate that wheat sprout has significantly higher diverse biological activities and apparently has significant health benefits.
        4,000원
        29.
        2019.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, as the global problem of marine debris and marine plastics is getting serious, various ways to solve them have been proposed, and the use of the biodegradable fishing gear is proposed as an alternative. Currently, 13 types of biodegradable fishing gears are available, but their penetration rate is only 8.7%. However, the need for the use of the biodegradable fishing gear is growing as awareness of protecting marine ecosystems is growing. Therefore, in this study, the economic effects of the expansion of biodegradable fishing gear distribution in Korea's coastal areas were analyzed through the conservation of marine ecosystems, augmentation of fisheries resources, and augmentation of fishing efficiency. According to the analysis, the economic effects of 52,795 million won, 105,590 million won, and 158,385 million won was generated as the distribution of biodegradable fishing gear were expanded to 10%, 20% and 30% across all gill net and trap.
        4,000원
        30.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the quality and antioxidant properties of three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria. During the fermentation, the pH was lowered and the titratable acidity increased. The viable cell counts of lactic acid bacteria increased 8.44-9.62 log CFU/g. Organic acid content (especially lactic acid) of sweet potatoes increased by fermentation. Also, γ-Aminobutyric acid increased more than 8.6 times by fermentation in all samples. The total polyphenol and flavonoid contents of sweet potato, showed insignificant changes in all samples by fermentation. ABTS radical scavenging activity of all samples slightly decreased by fermentation, but not significantly. DPPH radical scavenging activity decreased slightly by fermentation except Shinyulmi. However, when compared with the varieties, Shinjami showed the highest activity. The reducing power of Shinjami decreased slightly by fermentation, but activity was the highest among all samples. Based on these results, most of the chemical properties and functionality of fermented sweet potato are retained after fermentation, although some antioxidant activity decreases. We suggest that three fermented sweet potato cultivars (Shinyulmi, Hogammi, and Shinjami) using lactic acid bacteria can be used in various applications because of their effective functional properties.
        4,000원
        31.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        콩 가공 부산물인 콩 배아 이소플라본의 생체내 활성을 증가시키기 위하여 LA, LB, LP 등 3가지 유산균을 단독 또는 혼합하여 비배당체화 전환 효율을 증가시키고자 균주의 종류와 접종량, 발효시간에 따른 이소플라본 함량을 분석하였다. 그 결과 균주를 이용한 모든 발효에서 균주를 사용하지 않은 대조군에 비하여 높은 이소플라본 비배당체 전환을 보였고, 발효시간에 따른 비배당체 전환율은 24시간에서 급격히 증가하였고 이후에는 큰 변화는 보이지 않았다. 비배당체화 발효의 최적 균주는 LP균, 접종량은 5%, 발효시간은 24시간 이었다. 대조군의 이소플라본 배당체의 구성은 글리시틴>다이드진>제니스틴 순으로 가장 높은 함량을 나타내었고, 유산균을 접종하여 발효시켰을 때 배당체들은 감소하였고, 비배당체 함량이 증가하였으며, 다이드제인>글리시테인>제니스테인 순으로 45% 이상의 비배당체 전환율을 나타내었다. 특히, 대조군과 비교하여 유산균으로 발효시켰을 때 다이드진의 함량이 가장 크게 감소하였고, 다이드제인 함량이 가장 크게 증가하였다. 소야사포닌의 경우 발효에 의하여 Ab가 급격하게 감소하였고 Ba와 Bb가 증가하였다. 발효액은 pH 3에서 pH 6으로 증가함에 따라 이소플라본 비배당체 함량이 증가하였으며 특히, 다이드제인 함량이 많이 증가하였고, 소야사포닌 함량은 Ab 함량이 급격하게 감소하였고, Ba와 Bb 함량도 소량감소하는 등 발효액의 pH가 발효에 의한 이소플라본과 소야사포닌 함량 변화에 많은 영향을 미치는 중요한 요인중의 하나임을 알 수 있었고, LP균을 이용한 발효로 가공부산물인 콩 배아의 생리활성 증가 및 기능성소재화를 꾀할 수 있을 것 으로 생각된다.
        4,000원
        36.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concern on the greenhouse gas emissions is increasing globally. Especially, the greenhouse gas emission from fisheries is an important issue from the Paris Climate Change Accord in 2015. Furthermore, the Korean government has a plan to reduce the GHG emissions as 4.8% compared to the BAU in fisheries until 2020. However, the investigation on the GHG emissions from Korean fisheries rarely carried out consistently. Therefore, the quantitative analysis of GHG emissions from Korean fishery industry is necessary as a first step to find a relevant way to reduce GHG emissions from fisheries. The purpose of this research is to investigate which degree of GHG emitted from the major offshore fisheries such as offshore gillnet fishery, offshore longline fishery, offshore jigging fishery and anchovy drag net fishery. Here, we calculated the GHG emissions from the fisheries using the Life Cycle Assessment method. The system boundary and input parameters for each process level are defined for the LCA analysis. The fuel use coefficients of the fisheries are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for the unit weight of fishes are calculated with consideration to the different consuming areas as well. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries
        4,300원
        37.
        2018.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fossil fuel combustion during fishing activities is a major contributor to climate changes in the fishing industry. The Tier1 methodology calculation and on-site continuous measurements of the greenhouse gas were carried out through the use of fuel by the coastal and offshore gillnet (blue crabs and yellow croaker) and trap (small octopus and red snow crab) fishing boats in Korea. The emission comparison results showed that the field measurements are similar to or slightly higher than the Tier1 estimates for coastal gillnet and trap. In offshore gillnet and trap fisheries, Tier1 estimate of greenhouse gases was about 1,644-13,875 kg CO2/L, which was more than the field measurement value. The CO2 emissions factor based on the fuel usage was 2.49-3.2 kg CO2/L for coastal fisheries and 1.46-2.24 kg CO2/L for offshore fisheries. Furthermore, GHG emissions per unit catch and the ratio of field measurement and Tier1 emission estimate were investigated. Since the total catch of coastal fish was relatively small, the emission per unit catch in coastal fisheries was four to eight times larger. The results of this study could be used to determine the baseline data for responding to changes in fisheries environment and reducing greenhouse gas emission.
        4,000원
        38.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we developed a thermoelectric generation system for coastal fishing boats that allows for a high-density arrangement of thermoelectric modules, verified the improvement in performance by conducting comparative analysis between field test results and results from previous studies. The developed thermoelectric generation system was installed in a 3-ton gill-netter to analyze the engine revolutions per minute and energy production per day for each fishing process over a period of 20 days. From the experimental results, the maximum electric energy generated was 207.1 Wh, the minimum was 53.93 Wh and the average electric energy was 129.98 Wh. In accordance with the increasing of the engine r.p.m., the maximum electric production was 183 W at 1,500 r.p.m. It was approximately 80.5% of designed capacity, 227.2 W. Considering the result in the earlier research was 50.7% of designed capacity, 115.8 W. It was improved by 30% compared to the earlier one. The fishing operation was classified as departure, fishing and arrival. From the result on production analysis of electric energy, the composition of energy was 63% in fishing, 19.5% in departure and 17.5% in arrival. The electric energy production per unit hour was 42.8% in arrival, 32.9% in departure and 24.3% in fishing.
        4,000원
        39.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 아버지의 양육태도가 대학생 자녀의 학교생활적응에 자기효능감을 매개로 어떠한 관계가 있는지 규명함으로써 아버지의 양육태도가 자기효능감과 대학생활적응에 영향을 주고 있음을 밝히고자 하였다. 현재 4년제 대학에 재학 중인 3, 4학년 학생을 대상으로 설문조사를 실시한 후 SPSS 18.0을 활용하여 자료를 분석하였다. 각 변인의 평균, 표준편차를 도출한 후 각 측정 변인의 상관관계를 알아보기 위한 Pearson 적률상관분석을 실시하였다. 또한 지각된 아버지의 양육태도가 학교생활적응에 미치는 영향을 파악하기 위해 회귀분석을 시행하였다, 아버지의 양육태도와 학교생활적응 관계에서 자기효능감의 영향을 검증하기 위하여 Baron과 Kenny(1986)가 제안한 위계적 회귀분석을 실시하여 분석하였다. 그 결과 아버지의 양육태도인 아버지의 돌봄에서는 학교생활적응에 유의미한 정적상관으로, 아버지의 과보호는 부적상관으로 나타났다. 아버지의 양육태도는 자기효능감과 학교생활적응에 대부분 영향을 미치고 있었다. 또한 아버지의 양육태도에서 돌봄이 높을수록 자기효능감을 매개로 학교생활적응에 긍정적인 효과로 나타났다. 따라서 가정에서 아버지의 돌봄과 관심 및 관계 역할은 매우 중요하며, 과보호가 되지 않는 적절한 양육태도는 자녀의 자기효능감을 발달시키고, 대학생활을 잘 적응할 수 있도록 한다는 점을 시사하고 있다.
        6,400원
        40.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: This study aimed to evaluate differences in nursing performance of nursing college students following simulator training or video-based training for patients with respiratory distress. Methods: The study used a two-group post-intervention design. The simulator group was trained using a high-fidelity simulator and the video group with a best practices video. Nursing ability was evaluated by video recording participants during a dyspnea simulation exercise. The collected data was analyzed with a t-test using SPSS 21. Results: The simulator group showed lower scores than the video group in the preparation (t = -4.60, p < .001) and nursing intervention (t = -2.41, p = .033) categories. Conclusion: Video training is effective for simulation education in cases of dyspnea.
        4,000원
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