• 한국안전학회지
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• 제24권6호
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• pp.79-85
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• 2009

This study presents an algorithm to select the best alternative plane among various bridge superstructure types(Steel box girder, Rational girder, PSC-I girder) using Value Engineering(VE). Economical efficiency, landscape, constructability, maintenance, stability, function of bridge superstructure were taken into consideration in the designing of bridge. Economical efficiency was evaluated for each alternative plan with optimal design considering Life Cycle Cost(LCC). Repair and rehabilitation histories and some factors were set to get reasonable results. In the application of Analytic Hierarchy Process(AHP), consistency of Pairwise Comparisons Matrix was evaluated and the best plan was determined.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1130-1135
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• 2004

The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Vertical roller mill is subjected to the cyclic bending stress by rollers load. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to 30% of total maintenance. Therefore, this study shows optimal design for vertical roller mill using DOE and neural network.

• 한국국방경영분석학회지
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• 제27권1호
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• pp.58-72
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• 2001

This research deals with the weapon system RAM which is the reliability, availability and maintainability for weapon systems. This weapon system RAM is one of very important factors because it is related to the life cycle cost and combat readiness of weapon systems. Therefore, in this research we introduce the weapon system RAM and analyze the problems of weapon system RAM management during system life cycle including acquisition period. Finally we suggest an alternative to improve the weapon system RAM in various agencies which are the department of defense and army headquarter level, etc., in the process of defense acquisition.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.114-114
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• 2003

p53 has identified as a tumor suppressor protein to protect cells from DNA damage. p53, also well known for a transcription factor, can activate genes such as p21, bax, gadd45 and induce a number of the responses such as differentiation, senescence, DNA repair, apoptosis and the inhibition of angiogenesis to protect cells. Many mechanisms of p53 activation have been studied.(omitted)

• Molecules and Cells
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• 제26권4호
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• pp.350-355
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• 2008

Chk2 is a well characterized protein kinase with key roles in the DNA damage response. Chk2 is activated by phosphorylation following DNA damage, and relays that signal to various substrate proteins to induce cell cycle arrest, DNA repair, and apoptosis. In order to identify novel components of the Chk2 signaling pathway in Drosophila, we screened 2,240 EP misexpression lines for dominant modifiers of an adult rough eye phenotype caused by Chk2 overexpression in postmitotic cells of the eye imaginal disc. The rough eye phenotype was suppressed by mutation of the ATM kinase, a well-described activator of Chk2. Twenty-five EP modifiers were identified (three enhancers and 22 suppressors), none of which correspond to previously known components of Chk2 signaling. Three EPs caused defects in G2 arrest after irradiation with incomplete penetrance when homozygous, and are likely directly involved in the response to DNA damage. Possible roles for these modifiers in the DNA damage response and Chk2 signaling are discussed.

• Composites Research
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• 제19권1호
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• pp.43-48
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• 2006

High performance fiber reinforced cement composites have better performances than traditional cement based materials, therefore, have been expected as new construction applications such as the materials for construction & bridge structure, repair and rehabilitation applications, anti-collapse applications, anti-noise applications etc. However, they have lots of the problems such as material design, fabrication method and structural analysis. Also, the most serious problems of High performance fiber reinforced cement composites have been expensive initial cost, lack of long-term exposure data. As a result, it is needed that the efforts for lowering the initial cost and accumulation of long-term exposure. There has been hardly assessment results of life cycle cost for HPFRCC in construction field, but some papers showed that total life cycle cost could be profitable if the initial cost could be reduced.

• 응용통계연구
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• 제23권6호
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• pp.1147-1156
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• 2010

본 논문에서는 비 재생무료교체-수리보증이 종료된 이후의 수리가 가능한 시스템에 대한 교체정책을 제안한다. 이를 위해서, 비 재생무료교체-수리보증을 정의하고, 사용자 측면에서 비 재생무료교체-수리보증이 종료된 이후의 보전모형이 고려된다. 최적의 보전정책을 결정하기 위한 기준으로는 사용자 측면의 단위시간당 기대비용이 고려되고, 보증 기간이 종료된 이후에 발생되는 시스템의 유지비용은 사용자가 모두 지불하게 된다. 즉, 시스템의 운영기간 동안 사용자가 지불하여야 할 비용들이 주어져 있을 때, 비 재생무료교체-수리보증이 종료된 이후의 최적의 보전주기를 결정한다. 마지막으로 본 논문에서 제안된 보존정책을 설명하기 위해서 수치적 예를 살펴본다.

• 한국건축시공학회지
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• 제6권1호
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• pp.87-91
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• 2006

Since water leakage and cracks are not the source of serious problems such as long-term lowering of performance and durability of a stricture, including damages to operating facilities of a structure, damages to internal finishing materials, exhibition, and goods, and pollution of residential environment, they might have led to development of positive coping skills; however, an instant loss of lives or property due to earthquake, explosion, typhoon, or a fire was indeed neglected. In these days, repair materials for leakage cannot help but being taken in temporary way without any noticeable countermeasure. This kind of repair is socially criticized many times that is defective construction even if this costs a lot. It was not arrange the standard for construction methods of sealer of injection type for leakage maintenance, even it has been used various type of construction methods for leakage part. In conclusion, we suggest that the construction methods of sealer of injection type for leakage maintenance for leakage to establish the leakage repairing technology as increase of structure demand. Therefore, it would be possible to provide a stage-by-stage solution by developing systematic research activities among the industry, schools, and research institutes to spread maintenance management techniques globally through technical solution to water leakage and cracks, acquisition of structural safety with prolonged durability for life cycle, reduction of water leakage repair expense s, and so on.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.791-798
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• 2020

근래의 무기체계에서 첨단기술이 차지하는 비중은 점차 커지고 있으며, 빠른 기술발전 속도로 인하여 부품의 수명주기가 단축되고 실정이다. 이에 반하여 무기체계는 소요제기단계에서 운영/유지단계까지 오랜 시간이 소모되는 특성이 있다. 이로 인하여, 불가피하게 획득 단계에서 주요부품의 단종이 발생된다. 부품단종은 양산 일정 지연의 지연을 유발할 수 있으며, 나아가 운영유지단계에서는 원활하지 못한 부품 공급으로 운용가용도(Operational Availability)에 나쁜 영향을 미치게 된다. 한편, 사업관리자는 설계, 생산, 운영단계의 총수명주기 비용을 최소화하면서 성능을 극대화할 의무가 있으며, 이를 위해서는 적절한 부품단종관리 계획을 수립하고 이행할 필요가 있다. 본 논문에서는 적절한 부품단종관리를 통하여 절감할 수 있는 회피비용 및 총수명주기비용을 통하여 부품단종관리의 효용성을 분석하였다.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.237-243
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• 2020

A novel psychrotolerant Psychrobacillus strain PB01, isolated from an Antarctic iceberg, was comparatively analyzed with five related strains. The complete genome of strain PB01 consists of a single circular chromosome (4.3 Mb) and a plasmid (19 Kb). As potential low-temperature adaptation strategies, strain PB01 has four genes encoding cold-shock proteins, two genes encoding DEAD-box RNA helicases, and eight genes encoding transporters for glycine betaine, which can serve as a cryoprotectant, on the genome. The pan-genome structure of the six Psychrobacillus strains suggests that strain PB01 might have evolved to adapt to extreme environments by changing its genome content to gain higher capacity for DNA repair, translation, and membrane transport. Notably, strain PB01 possesses a complete TCA cycle consisting of eight enzymes as well as three additional Helicobacter pylori-type enzymes: ferredoxin-dependent 2-oxoglutarate synthase, succinyl-CoA/acetoacetyl-CoA transferase, and malate/quinone oxidoreductase. The co-existence of the genes for TCA cycle enzymes has also been identified in the other five Psychrobacillus strains.