• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.324-327
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• 1996

In this paper, the affecting factors of the access demand for the cellular service are derived, and the access demand function of the cellular service is estimated. The results obtained in this study are as follows: First, the price (access charge) and the income elasticities of cellular services there exists a network externality in cellular communication services. Third, the technological capability of the service provider has played an essential role in expanding the size of subscribers. Fourth, the access demand of cellular communication service is not sensitive to the usage charge. According to the above results, it can be inferred that if the access charge is lowered, the number if subscribers will increase to the critical mass, and then the cellular communication market will grow up to a saturation point naturally.

• 한국경영과학회지
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• 제23권4호
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• pp.63-73
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• 1998

With the success of flexible manufacturing systems(FMSs), flexible assembly systems(FASs) have been developed to automatic factories further. As in a cellular FMS, a celluar FAS is considered as the most flexible and feasible assembly systems configuration. This paper presents a method for the integrated layout design in cellular FASs. Unlike the traditional paper, this paper deals with the formation of cells and the layout of cells for jobs with operation times on different machines. The procedure in this paper consists of two distinct phases. The first phase presents machine arrangement in a double rows flowline. cell formation not to allow intercellular movements, and integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors This phase uses older optimal algorithm. The second phase proposes to balance the system with an objective of reducing the degree of workload deviation in the cells. Simulated annealing method is used to balance the system. This phase also shows the integrated layout design in cellular FASs with the cost less than total cost of the first phase.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.333-336
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• 1996

This paper is an exploratory study aimed at finding factors that influence the penetration of cellular mobile telecommunications which have seen rapid development since 1980s. The paper tries to find economy and policy variables to influence the penetration by means of the multiple regression analysis. This paper shows a model that explain the penetration ratio of cellular service. The model is based on data from 39 upper middle income and 39 high income countries. The result shows that GDP per capita and the service period of the cellular mobile telecommunication have influenced on the penetration ratio positively, and the tariff of the service negatively. But, it is the open area to study the impact of the telecommunications policy changes on penetration, and to set a model which could explain the nation-specific characteristics.

• BMB Reports
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• 제33권1호
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• pp.59-62
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• 2000

Hepatitis C virus (HCV) nonstructural 5B (NS5B) protein is an RNA-dependent RNA polymerase (RdRp). To determine whether it can contribute to viral replication by interaction with cellular proteins, the yeast two-hybrid screening system was employed to screen a human liver cDNA library. Using the HCV NS5B as a bait, we have isolated positive clones encoding a cellular protein. The NS5B interacting protein, 5BIP, is a novel cellular protein of 170 amino acids. Interaction of the HCV NS5B protein with 5BIP was confirmed by a protein-protein blotting assay. Recently, we have demonstrated that NS5B possesses an RdRp activity and thus it is possible that 5BIP, in association with NS5B, plays a role in HCV replication.

• 동의생리병리학회지
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• 제22권4호
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• pp.802-809
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• 2008

Gamijangsing-tang (GMJST) has been used for treatment of bone formation in traditional korean medicine. The purpose of this study is to examine effects of GMJST on bone metabolism. The effects on the osteoblasts were determined by measuring (1) cell proliferation, (2) alkaline phosphatase (ALP) activity, (3) osteoprotegerin (OPG) secretion. (4) The morphologic changes of cells were observed by light microscopy and electron microscopy. Mineralization of calcium was determined by quantitative alizarin red-S assay and mineralization of phosphate was observed by von kossa staining. The morphologic changes of mineralization on the cells were observed by transmission electron microscopy (TEM). The effects on the osteoclast were investigated by tartrate-resistant acid phosphatase (TRAP) staining. Following results were obtained: Celluar activity of osteoblastic cells (MG-63) was significantly increased in 10-5 of dilution of GMJST. ALP and OPG activity of osteoblastic cells were increased in GMJST than normal MG-63 cell. Mineralization of osteoblastic cells were increased in GMJST than normal MG-63 cell. The activity of osteoclast cells (RAW 264.7) was significantly decreased in GMJST than normal MG-63 cell. From the results, GMJST stimulated the proliferation and mineralization of bone-forming osteoblast and inhibited by bone- lysis osteoclast.

• Tuberculosis and Respiratory Diseases
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• 제63권2호
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• pp.165-172
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• 2007

폐암의 발생은 여러 많은 유전자의 변화가 축적되어 나타나는 일련의 과정에 의한다. 세포 내 전사 조절 인자의 하나인 CBP는 폐를 포함한 인체 내 여러 조직에서 상피세포의 분화 및 증식에 중요한 역할을 담당하며, 유전자들에서 전사조절인자로서 세포의 성장에 관여하며 발암 과정에서도 중요할 것으로 기대된다. 이에 아직까지 폐암에서 CBP에 대한 연구가 확정된 바가 없어, 폐의 전암성 병변(상피 화생 20예, 이형성증 40예) 및 편평상피세포폐암 60예를 대상으로 하여 CBP의 발현정도를 면역화학적 방법으로 비교 분석하여 다음과 같은 결과를 얻었다. 1) 화생성 병변(7예; 35%)에 비해 이형성 병변(26례; 65%)이나 편평세포암종(42례; 70%)에서 CBP의 발현이 유의하게 높았다(p<0.05). 2) 이형성 병변의 경우, 경도의 이형성 병변(20예 중 10예; 50%)보다 고도의 이형성 병변(20예 중 16예; 80%)에서 높은 CBP의 발현율을 보였다(p<0.01). 3) 편평세포암의 분화도별로 살펴보았을 때, 고분화암에서 95%(20예 중 19예), 중등도 분화암에서 85%(20예 중 17예), 저분화 암에서는 30%(20예 중 6예)의 발현율을 보였다(p<0.05). 이상과 같은 결과를 볼 때, CBP는 폐 조직에서 정상 기관지 상피 세포가 전암성 병변으로 변하거나 전암성 병변이 암으로 진행하는 과정에서 중요한 역할을 하는 것으로 보이며, 세포가 암으로의 발전할 수 있는 잠재성을 가늠하는 표지자가 될 수 있을 것으로 보인다.