• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.33.2-33.2
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• 2011

The 'NREL Phase VI' model with a 10.06m diameter was tested in the NASA Ames tunnel to make a reference data of the computational models. The test was conducted at the one rotational speed, blade tip speed 38m/s and the Reynolds number of the sectional airfoils in that test was around 1E6. The 1/5 scale down model of the 'NREL Phase VI' model was used in this paper to study the power characteristics in low Reynolds number region, 0.1E6 ~ 0.4E6 which is achievable range for the conventional wind tunnel facilities. The torque generated by the blade was directly measured by using the torque sensor installed in the rotating axis for a given wind speed and rotational speed. The power characteristics below the stall condition, lambda > 4, was presented in this paper. The power coefficient is very low in the condition below the Re. 0.2E6 and rapidly increases as the Re. increases. And it still increases but the variation is not so big in the condition above the Re. 0.3E6. This results shows that to study the performance of the wind turbine blade by using the scaled down model, the Re. should be larger than the 0.3E6.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.44-50
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• 2001

The rotated bending fatigue test was conducted in air md in 3.5% NaCl salt solution to investigate the fatigue fracture behaviour of raw material and F.E.M dual phase steel made from raw material(SS41) by a suitable heat treatment. This study has compared the initial microcrack creation of material by tensile test with that by fatigue test. And the rotated bending test of cantilever type under the condition of 3.5% NaCl salt solution and air has investigated the corrosion fatigue fracture behaviour with the variation of stress concentration factor determined by each of notch shapes. The initial microcrack have been developed in fragile grainboundary with general corrosion occurring in raw material : in the pits built up by corrosion in F.E.M. dual phase steel because pits bring out stress concentration. It is small that the degree of decrease in corrosion fatigue life for F.E.M. dual phase steel compared with raw material because the notch sensitivity of F.E.M. dual phase steel is lower than raw material in reason of characteristics with two-phase construction.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.636-639
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• 1993

This paper is discribed the results of insulation characteristic tests that are DC leakage current, test, tan${\delta}$ test, AC breakdown test and observation of tree in the used 6.6kV CV cables. In the correlation of these tests, the tan${\delta}$ test stands for the main deterioration factor of cable insulation.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.45-52
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• 2015

Acute toxicity tests for 5 organic solvents were conducted using Euglena agilis carter (E. agilis), a Korean domestic organism. Organic solvents decreased the growth rate of E. agilis in a dose dependent manner. The toxicity to E. agilis was increased in the order of chloroform>acetone${\geq}$ethanol${\geq}$methanol>DMSO based on $EC_{50}$ values from growth test. Organic solvents also induced cell motility and morphological changes of E. agilis. Especially significant effects on the cell swimming velocity, motility, and compactness were observed for chloroform at the concentration of $EC_{50}$ calculated from 96 hr growth test. Overall, toxic responses of E. agilis to test substances are comparable to or more sensitive than D. magna, M. macrocopa and V. fischeri. Our study demonstrates that E. agilis can be a putative ecotoxicity test model organism to assess domestic water quality. Results obtained from this study can be applied to establish the standard test guidelines for ecotoxicity test using E. agilis.

• KSBB Journal
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• v.19 no.3
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• pp.178-186
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• 2004

The aim of this study was to investigate the skin-whitening effect of okyong-san and to develop new drug delivery carrier The extracts of okyong-san were found to have the whitening effect and Eudragit$\^$ⓡ/ L 100-55 (EUD) coated solid lipid nanoparticle (E-SLN) was prepared by solvent evaporation method and melt dispersion technique. As a result, E-SLN have a 144-170 nm of particle size, spherical shape, and 33-41% encapsulation efficiency, After release test in vitro, release profile of E-SLN depended on pH and temperature. Lastly, closed patch test and skin-whitening test was peformed clinically. In conclusion, test sample had non-stimulation and high % whiteness. The results suggest that okyong-san and E-SLN is useful as cosmeceuticals for whitening cosmetics.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.63-66
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• 2008

Not only mechanical properties, bonding properties, electro chemical properties, etc. but also fire safety is required in patch repair materials such as polymer modified cement mortar (PCM) which are used to deteriorated reinforced concrete structure. Unfortunately, it is very difficult to choice the appropriate repair materials because there are not enough information about fire safety properties of PCM. In this study, The combustion characters of PCM were evaluated through the heat release rate test and non-combustibility test. The pyrogenicity test uses the cone calorimeter based on the oxygen consumption method. The non-combustibility test is from the temperature change inside the furnace during the test. The effect of the types of polymer and polymer content were evaluated from the series of test. The results are like followings. 1) The higher the W/C of PCM, the lower the gross calorific value and heat generation rate in the heat release rate test. The amount of heat generation of PCM is like the order of VVA, EVA, and SBR in this study. 2) Some materials such as E45-100, E50-100, E60-100, S50-50, and S50-100 were estimated as not appropriate building materials in the non combustibility test.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.647-654
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• 2000

During consolidation, the permeability of clay decreases with void ratio because of the reduction in total void space. After Kozeny(1927) and Carman(1956), many researchers have proposed the relations between void ratio and permeability. Most of the relations are expressed in the following forms as : (1) log e - log k(1+e), (2) e - log k, or (3) log e - log k. These relations have been found valid for a large number of normally consolidated clays. From laboratory test(CRS and I $L_{CON}$) results, the relation between void ratio and permeability of Kimhae clay was well defined in all of the three forms. Permeability change index, $C_{k}$, of Kimhae clay was in the range of 0.64~1,03 and average value of $C_{k}$ was 0.821. And the test results satisfied the experimental correlation between $C_{k}$ and e, $C_{k}$=0.5e. In log e - log k(1+e) relation, constant C was in the range of 1.91~4.74$\times$10$^{-8}$ cm/sec and n was in the range of 3.74~4.60.c and n was in the range of 3.74~4.60.74~4.60.0.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.127-128
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• 2023

게임관련 학업을 전공으로 하는 남학생 31명, 여학생 18명, 총 49명을 대상으로 e스포츠 관련 지식과 정부를 얼마나 많이 알고 있는가의 정보 수집의 차이에 대한 연구를 하였다. 그 결과 남학생의 평균 값은 3.22이고 여학생의 평균 값은 2.44로 두 집단의 평균의 차이를 보이고 있다. 두 집단간의 평균의 차이를 알기 위해 T-test를 실시한 결과, 유의수준 P값이 0.0024(P>0.05)로 남녀 두 집단간의 e스포츠에 관한 정보수집의 차이가 있는 것으로 나타났다.

• Korean Journal of Adult Nursing
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• v.19 no.4
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• pp.593-602
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• 2007

Purpose: The purpose of this study was to develop an e-learning orientation program for nursing students(junior), to evaluate the program, and to find out its effects on adapting to clinical practicum. Methods: The e-learning orientation program was developed according to ADDIE model(analysis, design, develop, implement, evaluate) using an Active Tutor Program. Twelve nursing professionals and 31 nursing students(learners) evaluated the e-learning orientation program. Thirty one nursing students participated in the e-learning orientation program both on-line and off-line. Results: The e-learning orientation program consisted of 5 parts including 'Taking a lesson in gastrointestinal tract', 'Fundamental nursing skill and reading a medical chart', 'Taking a ward orientation by head nurse', 'Clinical practice with preceptors', and 'Writing for case report'. Adapting scores to clinical practicum were significantly different between pre-test and post-test(t=-5.76, p=.000). Conclusion: The e-learning orientation program of on-line and off-line has an effect on adapting to clinical practicum for nursing students.

• Journal of the Korean Applied Science and Technology
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• v.40 no.3
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• pp.385-391
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• 2023

This study aims to examine the relationship between Serum Vitamin E and metabolic syndrome, which is a health risk, and to analyze the effect of Serum Vitamin E on the body. The analysis data were downloaded and used for the 7th 3rd (2018) data of the National Health and Nutrition Survey, and in this study, 944 men and 1,080 women were finally analyzed. For the analysis of the data, The chi-square test and t-test were used for the different values according to collected general characteristics and serum vitamin E, and the risk of metabolic syndrome was analyzed by regression, and Pearson correlation was used to confirm the correlation with each variable. Regression for Metabolic syndrome among the sub items and Serum Vitamin E showed that HDL-cholesterol was higher in the normal group than in the excess group (OR:1.042, CI:1.028-1.056), and triglycerides were significantly higher than in the normal group (OR:1.010, CI:1.009-1.012) (p<0.01). Therefore, it is proposed to develop nutrition and health programs suitable for the age of patients through this study.