• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.14-19
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• 2011

In this study, we extracted a whole polysaccharide fraction from the sea hare, Aplysia kurodai, and screened its functional properties using cell lines. The functionalities of polysaccharide and glycosaminoglycan (GAG) were investigated with RAW 264.7 cell lines. The crude polysaccharides and GAG purified DEAE-Sepharose chromatography did not show the toxicity on RAW 264.7 cell line in the range of $10\sim200{\mu}g$/mL, whereas they increased the cell growth rate. The crude polysaccharides and purified GAG also increased the production of NO, interleukin-6 and tumor necrosis factor-$\alpha$ on RAW 264.7 cell. Particularly, the purified GAG inhibited the proliferation of stomach cancer cell line, AGS, up to 40% for 72 hr incubation, but not the intestinal epithelial IEC-6 cell lines.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.245-253
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• 2010

The present study shows some results of developing evaporative heat exchangers with mini-channels. Heat exchangers with three different water paths were manufactured and tested to compare performances of cooling and pressure drop. Among the three types of heat exchangers, Type 2 with full-etching was proved to be the best in the cooling performances for considered operating conditions, and thus it is recommended to adopt Type 2 for its simplicity of production and outstanding performance. However, Type 1 was shown to be better when it is operated at a high air inlet temperature condition. The developed evaporative heat exchanger will be installed in Environmental Control Systems(ECSs) for aerial vehicles, and it can be used effectively in case an ECS is not only limited in its weight and volume but also required to absorb heats without supplying water (or a coolant) for a certain period of time.

• Progress in Medical Physics
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• v.6 no.2
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• pp.13-19
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• 1995

The behavior of the correction factor associated with the collimator opening(head-scatter factor) were investigated for the 6MV x-ray beams of medical linear accelerator. The primary photon fluence was measured in air quasi-small fied size. Consideration in this study was given to the effect of head scatter factor with quasi-small fied size, the upper and lower collimator jaw scatter collection factors of quasi-small field (4-10cm) were measured with ion chamber. In general, the wedge factors which are used clinical practics are ignored of dependency on field sizes and depth. In wedge factors for each wedge filter were measured at various depth by using 6MV X-ray. In this present we inverstigated systematically the depth and field sizes dependency to determine the absorbed dose more accurately. Head scatter(upper-lower collimator jaw)appears to be (1) a small effect, less than 5％ over the range of clinical field sizes (2) generated primarily at the flattening filter and therefored influenced most by the upper collimator setting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.62-70
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• 1989

The present study was designed to evaluate whether supplementation of dietary coenzyme Q10 protects the ADR-induced cardiotoxicity in rats. Experiment was undertaken under the condition of simultaneous adminstration of ADR and coenzyme Q10 for 4 weeks. Adriamycin treatment significantly decreased growth performance of rats. But this decrement was not modified by dietary supplementation of conzyme Q10. In the plasma creatine phosphokinase activity, there was no significant difference among experimental groups. Electron microscopic examination revealed a progression of myocardial lesions were dependent upon the level of ADR injection. The most frequently observed fine structural alterations in rat myocardium were mitochondrial swelling, dilation of the sarcoplasmic reticulum and the appearance of a perinuclear vacuolization. But these structural changes were somewhat lesser in defree by dietary supplementation of coenzyme Q10.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.494-494
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• 2012

최근에 현대 물리학과 과학의 정점에 있는 초전도가속기 같은 고에너지 빔 가속기 시스템에서 Diocotron instability의 연구가 재조명 되고 있다. 환형의 전자 빔 사이로 프로톤 빔을 통과시키는 구조로써 자기장과 회전하는 전자빔의 상호작용에 기초를 두고 있으며 이 환형의 전자 빔이 고에너지의 프로톤 빔을 집속하는 역할을 한다. 하지만 전자빔이 진행함과 동시에 왜곡되는 현상이 발생하는데 이 왜곡되는 현상을 충분히 조절하지 못한다면 프로톤 빔의 손실과 가속하는 빔의 에너지 저하를 초래하게 될 것이고 또한 실험장치 자체에도 큰 결함을 발생 시킬 수 있다. 따라서 Diocotron instability는 가속기를 활성화 하는데 주요한 테마가 될 것이다. 환형의 전자 빔 층은 정전기적 효과로 인해서 안쪽과 바깥쪽의 속도차가 발생하게 되고 이로 인하여 drift instability 가 발생하게 되어서 왜곡이 발생하고 결국에는 몇 개의 소용돌이를 생성하게 된다. 본 연구에서는 이를 2차원 원통형 구조의 Particle-in-cell 시뮬레이션을 통하여 연구하였으며 자기장의 효과에 따른 환형의 전자빔의 왜곡현상을 지연시키는 방안에 중점을 두었다. 특히 자기장의 세기, 전자빔의 밀도, 전자빔 층의 두께, 전자빔의 프로필의 차이에 의한 결과로 연구하였다.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.169-181
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• 2017

This is a study to examine the factors that affect group-buying social commerce users' repurchase intention. In order to verify research hypotheses, this paper collected data from 396 users who currently use the group-buying social commerce in China. We used the AMOS 22.0 analysis. The results show that value, trust and satisfaction are the strong predictors of repurchase intention. And Information quality, System quality and Service quality are the significant antecedents of value, trust and satisfaction. Finally, perceived value exerts stronger effect on repurchase intention for high-shopping habit customers, where as trust and satisfaction have higher influence on repurchase intention for low-shopping habit customers. Implications and limitations are discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.167-177
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• 2018

This study was conducted to investigate the effects of post-traumatic stress on the quality of life and effects of resilience in industrial accident patients. Participants in this study were 158 patients in an industrial hospital and general hospital in two metropolitan urban areas. Data were collected from July 1 to September 30, 2017 using self-report questionnaires and analyzed by descriptive statistics, Pearson's correlation coefficient, hierarchical regression, and Sobel's test using SPSS 21.0. There were significant negative correlations post-traumatic stress, quality of life, effects of resilience and were significant positive correlations quality of life, effects of resilience. The effects of resilience showed partial mediating effects, but not moderating effects on post-traumatic stress and quality of life. Post-traumatic stress and resilience explained 45% of the effects of industrial accidents on quality of life, post-traumatic stress explained 23% of the effects on quality of life, and the mediating effect of resilience was 22%. Based on the results of this study, it is necessary to develop interventions that improve quality of life by reducing post-traumatic stress and increasing resilience among workers who experience industrial accidents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1108-1113
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• 2003

We performed this study to determine the effect of green tea on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gammairradiation. The radioprotective effect of green tea was compared with the effect of diethyldithiocarbamate (DDC). Jejunal crypts were protected by pretreatment of green tea (p<0.01). Green tea administration before irradiation resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (p<0.05). The radioprotective effect on jejunal crypts and apoptosis in the DDC treated group appeared similar to those in the green tea treated groups. Treatment with DDC showed no significant modifying effects on the formation of endogenous spleen colony. These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.17-20
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• 2005

Natural products has been occasionally used in place of growth regulators to control lateral root formation and growth of soybean sprouts. The study was done to measure the effects of treatment concentration of hard rubber tree (Eucommia ulmoides Oliver) leaf extract on lateral root formation, growth and morphological characters of the sprouts. Seeds of three cultivars, Pungsannamulkong, Sowonkong and Junjery, were imbibed for 5 hours into water, its 5 and 10% solutions immediately before 6 day culture. The cultured sprouts were classified into 4 categories to calculate their composition rates on the base of hypocotyl lengths; >7 cm (A),4 to 7 cm (B),<4 cm (C) and not germinated (D), and their morphological characters, fresh and dry weights were measured. Rate of A was decreased with increased concentrations, while that of C showed reverse result compared to A. Regardless of concentrations, the former rate was less in cv. Junjery than in cv. Pungsannamulkong and Sowonkong than in cv. Junjery although the latter rate was truly opposite to the former one. In 10% treatment concentration, lateral roots were less formed in cv. Junjery although nearly formed in cv. Pungsannamulkong and Sowonkong. In all the 3 cultivars, lateral roots per sprouts were decreased with increased treatment concentration. shorter and thicker sprout was observed in cv. Junjery than in the other cultivars, and in increased concentrations compared to relatively lower ones. Total fresh weight was the greatest in cv. Sowonkong due to mainly increment of its hypocotyl, but was reduced with increased concentration due to mainly decrement of hypocotyl in all the cultivars.

• Food Science and Preservation
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• v.21 no.4
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• pp.549-559
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• 2014

This study investigated the hypoglycemic effects of mulberry leaf (M), green tea (G), and a mixture of mulberry leaf and green tea (MG) in rats with streptozotocin-induced diabetes. Male Sprague-Dawley rats were divided into the non-diabetic (N) and diabetic groups. The experimental animals were divided into four groups and fed the following for four weeks: a normal diet (N), the STZ+normal diet (STZ), the STZ+5% mulberry leaf (STZ-M), STZ+5% green tea (STZ-G), and the STZ+5% mixture of mulberry leaf and green tea (STZ-MG). The whole blood glucose level of the STZ-M, STZ-G and STZ-MG groups significantly decreased compared to the STZ group two weeks later. The serum glucose and fructosamine, and urine glucose levels in the STZ-M, STZ-G and STZ-MG groups were lower than in the STZ group. The levels of serum insulin were higher in the STZ-M, STZ-G and STZ-MG groups than in the STZ group. However, serum glucose, fructosamine and insulin levels, and urine glucose levels were not significantly different among the STZ-M, STZ-G and STZ-MG groups. These results indicate that mulberry leaf, green tea, and their mixture help prevent or attenuate the progression of diabetes in rats with STZ-induced diabetes.