• 한국화재소방학회논문지
• /
• 제33권5호
• /
• pp.19-27
• /
• 2019

저점도 에폭시 수지(EP)를 기본으로하고 캡슐화된 소화약제(EFA)를 50 wt%의 함유한 소화복합재료가 얻어졌다. 탈캡슐화된 EFA의 동역학 및 온도에 대한 EP의 긍정적인 효과가 확립되었다. EP는 EFA의 탈캡슐화 온도를 130 ℃에서 155 ℃로 증가시키고 캡슐화의 역학을 변화시킨다. 에폭시 매트릭스는 순수한 EFA와 비교하여 EFA의 열 안정성을 3.9배 이상 증가시킨다. EFA의 저장 안정성에 대한 EP의 보호 효과가 발견되었다. 60 ℃ 및 80% 습도에서 96시간 동안 EFA를 함유하는 EP의 질량 손실은 0.4%이고, 동일한 조건에서 순수한 EFA의 질량 손실은 15%이다. 자외선의 영향 아래에서 EP의 동일한 효과: 순수한 EFA가 6%인 경우 EFA를 함유한 EP는 0.8% 손실된다. 대안의 중합체 매트릭스의 시험이 고려되었다.

• 한국유기농업학회지
• /
• 제11권3호
• /
• pp.37-53
• /
• 2003

The purpose of this study is to analyze policies on environmental-friendly agriculture(EFA) and find out some implications. As we know well, EFA contributes environmental substantiality by using organic production methods and provides consumers with a secure, safe nutritious food supply. As consumption of environmental-friendly agricultural products increasing, policies on EFA began in the 1990s and it has been generally expanded in Korea. The strategies for sustainable EFA aim to promote harmony among human beings and between humanity and nature require. In addition, support to develop marketing activities, regionalization, and political support must be further developed.

• 한국유기농업학회지
• /
• 제13권1호
• /
• pp.69-84
• /
• 2005

Pureundeul fanning corporation(PFC) is an cgmplary body of all producer organizations for environmentally friendly agriculture(EFA) in Korea. It is located at Asan in Chungnam and has 301 farmers. They attained more than 10 billion wons as a sale in 2004. And The direct marketing channel of the EFA products is the second logistics center(Asan) ${\to}$ the first logistics center(Gwangju Gyunggi) ${\to}$ local hansalim shops ${\to}$ consumers. It is needed to construct the system of the direct marketing as follows : First, it needs to construct the direct marketing system within the region for EFA products of Asan. Second, the direct shop and suppling area should be enlarged as a way to promote sales with the demand increase of EFA products. Third, an aggressive promotion campaign is be needed for increasing motivation of consumption and understanding of EFA products.

• 한국유기농업학회지
• /
• 제23권4호
• /
• pp.735-748
• /
• 2015

Main aims of environment-friendly agriculture (EFA) are increasing functions for environmental conservation of agriculture and building consumer confidence for agricultural products safety. The low-pesticide certification will be abolished in 2016, and this will give rise to much confusion to low-pesticide certification producers. The non-pesticide agriculture doesn't mean organic farming, and the EFA standards of Korea don't match up to international standards to organic agriculture. The system improvement directions for EFA are to devide into two types of organic farming and EFA, and EFA includes non-pesticide and low-pesticide farming both. These types must have legal grounds respectively.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제7권1호
• /
• pp.174-194
• /
• 2015

In this paper, an Energy Flow Analysis (EFA) for coplanar coupled Mindlin plates was performed to estimate their dynamic responses at high frequencies. Mindlin plate theory can consider the effects of shear distortion and rotatory inertia, which are very important at high frequencies. For EFA for coplanar coupled Mindlin plates, the wave transmission and reflection relationship for progressing out-of-plane waves (out-of-plane shear wave, bending dominant flexural wave, and shear dominant flexural wave) in coplanar coupled Mindlin plates was newly derived. To verify the validity of the EFA results, numerical analyses were performed for various cases where coplanar coupled Mindlin plates are excited by a harmonic point force, and the energy flow solutions for coplanar coupled Mindlin plates were compared with the classical solutions in the various conditions.

• 유통과학연구
• /
• 제13권9호
• /
• pp.103-112
• /
• 2015

Purpose - This paper aims to provide a step-by-step approach to factor analytic procedures, such as principal component analysis (PCA) and exploratory factor analysis (EFA), and to offer a guideline for factor analysis. Authors have argued that the results of PCA and EFA are substantially similar. Additionally, they assert that PCA is a more appropriate technique for factor analysis because PCA produces easily interpreted results that are likely to be the basis of better decisions. For these reasons, many researchers have used PCA as a technique instead of EFA. However, these techniques are clearly different. PCA should be used for data reduction. On the other hand, EFA has been tailored to identify any underlying factor structure, a set of measured variables that cause the manifest variables to covary. Thus, it is needed for a guideline and for procedures to use in factor analysis. To date, however, these two techniques have been indiscriminately misused. Research design, data, and methodology - This research conducted a literature review. For this, we summarized the meaningful and consistent arguments and drew up guidelines and suggested procedures for rigorous EFA. Results - PCA can be used instead of common factor analysis when all measured variables have high communality. However, common factor analysis is recommended for EFA. First, researchers should evaluate the sample size and check for sampling adequacy before conducting factor analysis. If these conditions are not satisfied, then the next steps cannot be followed. Sample size must be at least 100 with communality above 0.5 and a minimum subject to item ratio of at least 5:1, with a minimum of five items in EFA. Next, Bartlett's sphericity test and the Kaiser-Mayer-Olkin (KMO) measure should be assessed for sampling adequacy. The chi-square value for Bartlett's test should be significant. In addition, a KMO of more than 0.8 is recommended. The next step is to conduct a factor analysis. The analysis is composed of three stages. The first stage determines a rotation technique. Generally, ML or PAF will suggest to researchers the best results. Selection of one of the two techniques heavily hinges on data normality. ML requires normally distributed data; on the other hand, PAF does not. The second step is associated with determining the number of factors to retain in the EFA. The best way to determine the number of factors to retain is to apply three methods including eigenvalues greater than 1.0, the scree plot test, and the variance extracted. The last step is to select one of two rotation methods: orthogonal or oblique. If the research suggests some variables that are correlated to each other, then the oblique method should be selected for factor rotation because the method assumes all factors are correlated in the research. If not, the orthogonal method is possible for factor rotation. Conclusions - Recommendations are offered for the best factor analytic practice for empirical research.

• 한국환경농학회지
• /
• 제28권3호
• /
• pp.301-309
• /
• 2009

The use of bioactive materials derived from microorganisms and plants has played a role in pest management in environmentally-friendly agriculture (EFA) system. In Korea, a number of agricultural agents for the control of insect pests have been registered officially as biopesticides and marketed widely. However, most of the biopesticides has a limitation in the resource availability of bioactive materials, which has been one of main problems related to the commercialization of agricultural agents. Plant materials and microbial metabolites are the best sources as starting components to commercialize natural-occurring agricultural agents for pest management. The lack of modernized system for the standardization and quality control of the starting materials, however, has also received as a main problem related to the commercialization of agricultural agents. Considered that EFA business has kept growing bigger and bigger with global economic status, the commercialization of agricultural agents is necessary to meet the required number of agricultural agents officially available in EFA. This study describes the status and future prospects of pest control agents in EFA. A number of main issues hindered in the commercialization of agricultural agents are discussed in order to present a promising approach to successful commercialization.

• 한국산학기술학회논문지
• /
• 제17권2호
• /
• pp.536-544
• /
• 2016

최근 초고층 구조물이 증가함에 따라 구조내력 확보를 위해 80~100 MPa 수준의 초고강도 콘크리트 사용이 증가하고 있는데, 이들 구성 재료 중 사용량이 가장 많은 골재는 종류나 특성에 따라 초고강도 콘크리트의 성능 및 경제성에 미치는 영향이 크므로 이에 대한 고찰이 요구된다. 이에 본 연구에서는 100 MPa 급 초고강도 콘크리트의 공학적 특성에 미치는 잔골재 영향을 고찰하고자, 석회암잔골재(LFA), 전기로 산화 슬래그 잔골재(EFA), 세척사(SFA) 및 화강암 부순 잔골재(GFA)의 4종과 이들을 상호 혼합한 4종의 혼합골재를 선정하여 초고강도 콘크리트의 공학적 특성을 고찰하고자 한다. W/B 20%에서 보통포틀랜드시멘트:플라이애시:실리카흄의 비율을 7:2:1로 조합한 콘크리트를 제조하였다. 연구결과에 따르면 LFA 사용 배합이 양호한 잔골재의 입형 및 입도 등 입자특성에 기인하여 동일 고성능 감수제 사용량에서 가장 높은 슬럼프 플로 및 높은 충전성을 확보하며, 혼합골재 사용 배합에 비해 전반적인 유동성이 우수함을 확인할 수 있었다. 또한, 압축강도 및 자기 수축 저감 성능은 EFA 및 LFA 사용 배합이 여타 골재 종류 및 혼합조합에 비해 골재 자체의 양호한 탄성계수 및 강도 그리고 EFA의 free-CaO에 기인하여 보다 양호한 성능을 갖고 있음을 확인하였다.

• 국방과기술
• /
• 8호통권186호
• /
• pp.8-9
• /
• 1994

• 한국식품과학회지
• /
• 제37권4호
• /
• pp.648-655
• /
• 2005

본 연구는 식품소재로의 이용 가능한 천연물을 이용하여 두 종류의 자양강장용 식품(formula A와 formula B)을 배합하고 복합물의 효능을 평가하였다. 실험 결과, EC군에 비하여 EFA군과 EFB군의 강제 수영능력시간이 각각 평균 42%와 38% 증가되는 유의적으로 높은 수영능력을 보였으며(p<0,05), 90분간 수영을 한 군(90-min subgroups)에서 EC군에 비하여 EFA군 및 EFB군의 혈청 유리지방산과 중성지방의 농도가 유의적으로 낮았고(p<0.05), EFB군의 혈청 암모니아의 농도가 EC군에 비하여 유의하게 낮은 수치를 보였다(p<0.05). 또한, EFB군의 근육 글리코겐 농도가 EC군에 비하여 높은 경향을 보였으나, 통계적으로 유의한 차이는 보이지 않았다. 이상의 결과로 미루어 보아 본 연구에서 선정한 복합물 2종은 실험동물의 체내 중성지방으로부터 유리지방산으로의 전환을 촉진하여 단백질과 포도당을 절약하고, 에너지 생성 및 공급 효율 증가, 운동으로 야기되는 체조직 손상 억제 그리고 피로물질 축적 지연 등의 효과를 가져와 강제수영능력을 증가시킨 것으로 생각된다.