• Journal of Nutrition and Health
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• 제32권7호
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• pp.838-843
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• 1999

Antitumor effects of various teas have been studied for a long time. Among them, green tea is one of the most popular test and very close to our lives in Korea. However, precise effect and mechanism about antitumor effects of green tea were not estabilished. The present study investigated the antitumor effect of catechin, which is main component of green tea, which was produced in Korea, was used. In each group, morphological changes were observed induced severe cell damage and growth inhibition gradually until 24hours. Then catechin effect was found to be concentration-and time-dependent. EATC was injured abruptly at 100ug/ml catechin treatment for 6 hours and the effect lasted constantly until 24 hours. But in both of cell lines, cell damage and inhibition of proliferation did not show up apparently at concentration of 10 and 1ug/ml. In contrast, catechin led to little or no effect against HepG2 in all of concentrations and periods. These results suggest that catechin extracted from green tea had different effect on cancer cells as cell type, concentration and period. Therefore green tea would be helpful to cancer treatment as well as cancer prevention and this study would be the basic source for further research of green tea.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.121-131
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• 2005

고속 수중 어뢰의 추진을 위해 외부에서 공급 받은 물과 증기로 연소 하는 수(水)반응성 연료를 이용하고 있다. 수(水)반응성 연료의 주성분은 마그네슘과 알루미늄처럼 반응성이 큰 금속들을 이용하며, 이 금속들은 수증기와 높은 열량과 함께 로켓 추력 실에서 연소 시킨다. 위 금속들의 연소 속성에 대한 해석은 이미 완료되었다. 수반응성 추진제의 가능성 있는 변형체에 대한 개념들은 수반응성 추진제 설계의 기초적인 제안들을 기하학 및 열역학적 연소 조건을 이용하여 논의 할 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2835-2839
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• 2014

Prostate cancer is one of the most prevalent malignant cancers in men. The isoflavone formononetin is a main active component of red clover plants. In the present study, we assessed the effect of formononetin on human prostate cancer DU-145 cells in vitro, and elucidated posssible mechanisms. DU-145 cells were treated with different concentrations of formononetin and cell proliferation was assessed by MTT assay, cell apoptosis by Hoechst 33258 and flow cytometry, and protein levels of RASD1, Bcl-2 and Bax by Western blotting. The results showed that formononetin inhibited the proliferation of DU-145 cells in a dose-dependent manner. DU-145 cells treated with different concentrations of formononetin displayed obvious morphological changes of apoptosis under fluorescence microscopy. In addition, formononetin increased the proportion of early apoptotic DU-145 cells, down-regulated the protein levels of Bcl-2 and up-regulated those of RASD1 and Bax. The level of RASD1 reached its maximum at 48h post-treatment, and rapidly decreased thereafter. Together, we present evidence that formononetin triggered cell apoptosis through the mitochondrial apoptotic pathway by up-regulating RASD1.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7537-7542
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• 2013

Background: Terpinen-4-ol, a monoterpene, is found as the main component of essential oil extracts from many plants. In this study apoptotic and autophagic types of cell death induced by terpinen-4-ol and associated mechanisms were investigated in human leukemic HL-60 cells. Materials and Methods: The cytotoxicity of human leukemic U937 and HL-60 cells was determined by MTT assay. Cytochrome c release, expression of Bax, Bcl-2, Bcl-xl and cleaved Bid were determined by Western blotting. Cell morphology was examined under a transmission electron microscope. LC3-I/II, ATG5 and Beclin-1 levels were detected by immunoblotting. Results: Terpinen-4-ol exhibited cytotoxicity to human leukemic HL-60 but not U937 cells. The apoptotic response to terpinen-4-ol in HL-60 cells was due to induction of cytochrome c release from mitochondria and cleavage of Bid protein after the stimulation of caspase-8. There was a slightly decrease of Bcl-xl protein level. The characteristic cell morphology of autophagic cell death was demonstrated with multiple autophagosomes in the cytoplasm. At the molecular level, the results from Western blot analysis showed that terpinen-4-ol significantly induced accumulation of LC3-I/II, ATG5 and Beclin-1, regulatory proteins required for autophagy in mammalian cells. Conclusions: Terpinen-4-ol induced-human leukemic HL-60 cell death was via both autophagy and apoptosis.

• 시스템엔지니어링학술지
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• 제12권1호
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• pp.89-103
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• 2016

Due to safety of the plant, it became very clear the importance of study occurrence reactor coolant system (RCS) issues specially the primary water stress corrosion cracking (PWSCC). The Systems Engineering (SE) approach is characterized by the application of a structured engineering methodology for the design of a complex system or component. Robotic devices have been used for internal inspection, maintenance and performing remote welding and inspection in high-radiation areas. In this paper, PWSCC overview and inlay and over lay welding methodology introduced, concept of robotic device that can be inserted into the piping via Steam Generator (SG) main way to access to primary piping of pressurized water reactor (PWR) is developed based on SE methodology. A 3D model of the inspection system was developed along with the APR1400 (Advanced Power Reactor)reactor coolant systems (RCS) and internals with virtual 3D simulation of the operation for visualization to prove the validity of the concept.

• Journal of Astronomy and Space Sciences
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• 제17권1호
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• pp.67-76
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• 2000

2002년에 발사 예정인 과학 위성 1호의 주 탑재체로 원자외선 분광기가 실릴 예정이다. 원자외선 분광기는 영상과 함께 분광의 기능을 함께 수행을 하게 되는데, 이를 위해 광학적인 요소로서 포물 원통 반사경, 슬릿, 타원형 회절 반사경, 그리고 MCP가 사용된다. 천문학적 관측 목표의 달성을 위한 각 광학 요소의 생산 오차와 위치 오차의 허용 한계를 구하였으며, 이 과정에서 도식적 단순화를 통해 민감도표를 해석하여 각 광학 요소의 조작 범위와 정밀도 등을 구하였다. 선형 오차의 경우 $15{\mu}m$, 각 오차의 경우 2' 이내의 정밀도로 광학적 요구 조건을 만족할 수 있을 것이다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권6호
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• pp.604-608
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• 2008

TFT-LCD영상은 불균일한 휘도 변화를 어느 정도 허용하고 있으며, 영상 전반에 걸쳐 나타나는 큰 휘도 변화는 국부적으로 주변 영역과 차이가 나는 결함 영역을 찾는데 방해가 된다. SQI(Self Quotient Image)는 얼굴 인식 분야에서 저주파에 해당하는 조명성분을 제거 하는데 사용되어 왔으며, 일종의 High Pass Filter(고주파 통과 필터) 형태이다. 본 논문에서는 SQI가 신호의 저주파 성분을 평활화 하는 효과를 가지면서 국부적인 변화를 유지하는 특성을 가지는데 착안하여, TFT-LCD영상에 존재하는 결함을 강조하는 알고리즘을 제안하였다. 제안한 방법을 기존의 TFT-LCD영상 전처리 방법들과 비교하였을 때, 평활화 효과 및 결함 영역 강조 효과가 우수함을 확인할 수 있었다.

• 한국안전학회지
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• 제31권4호
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• pp.97-103
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• 2016

This study investigates effects of partially earth anchored cable system on the structural safety for a long-span cable-stayed bridge under dynamic loads such as seismic and wind load. For a three span cable-stayed bridge with a main span length of 810 m, two models are analyzed and compared; one is a bridge model with a self anchored cable system, the other is a bridge model with a partially earth anchored cable system. By performing multi-mode spectrum analysis for a prescribed seismic load and multi-mode buffeting analysis for a fluctuating wind component, the structural response of two models are compared. From results, the partially earth anchored cable system reduce the maximum pylon moment by 66% since earth anchored cables affect the natural frequencies of girder vertical modes and pylon longitudinal modes. In addition, the girder axial forces are decreased, specially the decrement of the axial force is large in seismic load, while girder moment is slightly increased. Thus, the partially earth anchored cable system is effective system not only on reduction of girder axial forces but also improvement of structural safety of a cable-stayed bridge under dynamic loads such as seismic and wind loads.

• 대한한의학원전학회지
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• 제23권4호
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• pp.1-11
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• 2010

"Gyeongbangsilheomrok(經方實驗錄)" is a book that was written for the propagation of the thought of Gyeongbang(經方) theory in the early 20th century. Gyeongbang means the medicine in "Sanghanron(傷寒雜病論)" which was written by Jangjonggyeong(張仲景), who is known as a great doctor of ancient times in China. Gyeongbang had worked as a good model of medicine for a long time, but as time goes by, there appeared some physicians pointing out the limit of Gyeongbang and trying to overcome it. Through the effort like this, there gradually had appeared so many physicians carrying out the medical treatment which was getting out of the boundary of Gyeongbang. And There also had appeared a group of physicians, called Gyeongbangpa(經方派), opposing the opinion like this and defending the academic value of Gyeongbang. "Gyeongbangsilheomrok" had been estimated as a meaningful achievement of Gyeongbangpa tradition, and also had been regarded as a good book comprising copious basic theory about Bangje(方劑). The most significant assertion in this book is that it explained the Onbyeong(溫病) theory as a component itself in "Sanghanron(傷寒論)", which had been argued by many other medicians thinking that "Sanghanron" did not cover the treatment of Onbyeong. In regarding to this problem, "Gyeongbangsilheomrok" argued that the concept of Onbyeong in "Sanghanron" belongs to the category of Taeyangbyeong(太陽病) and also suggested that Galgeuntang(葛根湯) would be the main recipe for Onbyeong.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.869-871
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• 2005

As deregulated electricity markets are being implemented in different countries, the remuneration of reactive power which contribute to ancillary services is one of the key issues, so it is necessary to evaluate the generator's reactive. In this paper, we focus on the evaluation of reactive power which contributes to reactive power balance. The idea is that the main usages of the reactive power of generator can be divided into two components. First one is physically required amounts for transmitting the real power and the second one is the amounts contributed to support the system, that is, to maintain the voltage profiles. In this paper, the second component is used to evaluate the effective amounts of the reactive power contributed to ancillary service.