• Computational Structural Engineering : An International Journal
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• 제1권1호
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• pp.59-69
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• 2001

This study is intended to propose a systematic approach for reliability-based assessment of life cycle cost (LCC) effectiveness and economic efficiency for cost-effective seismic upgrading of existing bridges. The LCC function is expressed as the sum of the upgrading cost and all the discounted life cycle damage costs, which is formulated as a function of the Park-Ang damage index and structural damage probability. The damage costs are expressed in terms of direct damage costs such as repair/replacement costs, human losses and property damage costs, and indirect damage costs such as road user costs and indirect regional economic losses. For dealing with a variety of uncertainties associated with earthquake loads and capacities, a simulation-based reliability approach is used. The SMART-DRAIN-2DX, which is a modified version of the well-known DRAIN-2DX, is extended by incor-porating LCC analysis based on the LCC function developed in the study. Economic efficiencies for optimal seismic upgradings of the continuous PC segmental bridges are assessed using the proposed LCC functions and benefit-cost ratio.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1132-1140
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• 2007

As it recently appears that Life Cycle Cost Analysis may be considered as new methodology for economic valuation of infrastructure many researches have been made to assess LCC(Life Cycle Cost) of each facility based on a reasonable methods. In general, LCC is composed of construction cost and expected maintenance repair cost. And especially, maintenance repair cost must be estimated to enhance the reliability through systematic and reasonable methods. However in Korea, because high speed railway steel bridges are recently constructed no direct statistical data are available for the account of the maintenance cost and then their maintenance characteristics are not linear yet. Therefore, the approach proposed in the paper utilizes a theoretical determination and degradation of the corrosion and fatigue of the bridges based on Rahgozar et al.(2006)'s model on fatigue notch factor considering into the corrosion to incorporate the corrosion effect into the fatigue strength reduction model. And then, the corresponding probability of failure is calculated in terms of the reliability index using S-N curve to formulate the fatigue limit state. Therefore, this paper proposes the minimum Life Cycle Cost through optimum maintenance plan analysis of high-speed railway steel bridges under construction. Finally, this paper reviews the proposed model in oder to confirm the applicability and feasibility by appling it to high speed railway steel bridges under construction

• 성인간호학회지
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• 제26권2호
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• pp.139-148
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• 2014

Purpose: This study was aimed to investigate the factors influencing problem drinking of male drinkers above 19 years old according to the life cycle. Methods: The study subjects consisted of a representative community sample of 2,229 male drinkers aged 19 and older from the 2011 Korean National Health and Nutrition Examination Survey. The collected data were analyzed using descriptive statistics, Rao-Scott $x^2$-test, simple and multiple logistic regressions. Results: The problem drinking rates were 38.7% in adolescence, 44.5% in middle age, and 23.9% in senescence. In adolescence, the predictors of problem drinking included occupation, stress recognition, and smoking. In middle age, the predictors of problem drinking were education level, depression, and smoking. In senescence, the predictors of problem drinking were not identified in this study. Conclusion: The findings of this study suggested that the factors influencing problem drinking of male drinkers were different according to life cycle. Thus different intervention methods should be developed for each age group in order to intervene the problem drinking.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.7-12
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• 2000

The automatic turbine startup system provides turbine control based on thermal stress. During the startup, control system monitors and evaluates main components of turbine using damage mechanism and life assessment. In case of valve chest, the temperature of inner/outer wall is measured by thermo-couples and the safety of these values are evaluated by using allowable ${\Delta}T$ limit curve during the startup. Because allowable ${\Delta}T$ limit curve includes life assessment, it is possible to apply this curve to turbine control system. In this paper, low cycle fatigue damage and combined rupture and low cycle fatigue damage criterion proposed for yielding the allowable ${\Delta}T$ limit curve of CV(control valve) chest. To calculate low cycle fatigue damage, the stress analysis of valve chest has peformed using FEM. Automatic turbine startup to assure service life of CV was achieved using allowable ${\Delta}T$ limit curve.

• 유통과학연구
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• 제7권1호
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• pp.91-104
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• 2009

본 연구의 목적은 제품수명주기(PLC)와 시장 리스크 관리(MRM)의 상관관계를 규명하는 데 있다. PLC는 기업이 경영성과를 증진시키기 위하여 마케팅적인 시각에서 소비자의 구매행동과 가격 및 판매변동성을 분석한다. 따라서 이 연구에서는 MRM을 활용하여 PLC를 포괄적이고 통합적인 시각에서 분석하고자 한다. 두 이론 간의 관련성을 규명하기 위하여 본 연구는 PLC와 MRM의 경영성과에 공통적으로 영향을 미치는 요인들을 추출한다. 그리고 MRM의 관점에서 PLC의 요인들을 분석한다. 연구결과 PLC와 MRM은 가격변동성과 거래 리스크 및 시장점유율면에서 관련이 있음을 보여준다.

• 대한기계학회논문집A
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• 제26권1호
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• pp.1-6
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• 2002

The automatic turbine startup system provides turbine control based on thermal stress. During the startup, control system monitors and evaluates main components of turbine using damage mechanism and life assessment. In case of valve chest, the temperature of inner/outer wall is measured by thermo-couples and the safety of these values are evaluated by using allowable △T limit currie during the startup. Because allowable ΔT limit curve includes life assessment, it is possible to apply this curve to turbine control system. In this paper, low cycle fatigue damage, combined rupture and low cycle fatigue damage criterion were proposed for yielding the allowable ΔTf limit curve of CV(control valve) chest. To calculate low cycle fatigue damage, the stress analysis of valve chest has been performed using FEM. Automatic turbine startup to assure service life of CV was achieved using allowable ΔT limit curve.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.519-522
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• 2006

본 연구는 LCA(Life Cycle Assessment, 전과정평가) 개념을 바탕으로 토목시설의 환경성 평가를 위한 의사결정시 유용한 정보를 제공하기 위하여 사례대상으로 선정된 다목적댐 비상여수로의 위치 및 형식별로 발생 가능한 환경오염물질에 대한 환경부하량을 예측하고자 하였다. 이를 위해 LCA 기법의 이론을 고찰하고, 제안된 토목시설물의 사례대상인 다목적댐 비상여수로에 적용하기 위해 전과정 동안 발생하는 환경오염물질에 대한 환경부하량을 산출하고, 예측결과를 통하여 비상여수로의 환경성을 평가하고 친환경적인 최적대안을 도출하였다.

• 한국해안·해양공학회논문집
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• 제23권6호
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• pp.422-428
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• 2011

잔교식 안벽의 생애주기비용(Life Cycle Cost, LCC)을 이용하여 신뢰도지수의 최적값을 구하였다. 응답면 기법을 이용한 신뢰성해석을 통해 횡잔교와 돌제식 잔교의 파괴확률을 산정하였다. 파괴확률은 잔교의 파괴 시 복구비용을 산출하는데 활용하였으며 초기공사비와 유지관리비를 모두 고려한 LCC를 최소화시킬 수 있는 신뢰도지수를 찾았다. 지진하중과 접안하중에 대한 다양한 조건에서의 최적 신뢰도지수를 구하였고 이를 통해 신뢰성설계에 사용할 수 있는 목표신뢰도지수를 제안하였다.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.177-182
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• 2012

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at $5-15{\mu}M$. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

• 환경영향평가
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• 제9권3호
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• pp.185-202
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• 2000

Uncertainty and variability in Life Cycle Assessment(LCA) have been significant key issues in LCA methodology with techniques in other research area such as social and political science. Variability is understood as stemming from inherent variations in the real world, while uncertainty comes from inaccurate measurements, lack of data, model assumptions, etc. Related articles in this issues were reviewed for classification, distinguish and elaboration of probabilistic/stochastic health risk analysis application in LCA. Concept of focal zone, streamlining technique, scenario modelling and Monte Carlo/Latin Hypercube risk analysis were applied to the uncertainty/variability analysis of health risk in LCA. These results show that this general framework of multi-disciplinary methodology between probabilistic health risk assessment and LCA was of benefit to decision making process by suppling information about input/output data sensitivity, health effect priority and health risk distribution. There should be further research needs for case study using this methodology.