• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.63-68
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• 2002

Life Cycle Cost analysis technique is introduced to evaluate cost-effectiveness of two paint systems of steel bridges. The systems are a conventional paint system and a galvanized paint system. The all costs during safe lift such as initial cost repainting costs, disposal costs are considered for the lift cycle cost analysis. The NIST model is used and BridgeLCC 1.0 developed by the NST is utilized as the lift cycle cost analysis tool. It is concluded that, in spite of expensive initial cost, the durable paint system may be cost-effective compared with conventional paint system.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.48-56
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• 2009

This paper presents the procedure for the optimal design of a PSC-I girder bridge considering life cycle cost (LCC). The load carrying capacity curves for the concrete deck, PSC-I girder and $\pi$-type pier were derived and used for the estimate of service lives. Total life cycle cost for the service life was calculated as sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The advanced First Order Second Moment method was used to estimate the damage cost. The optimization method was applied to the design of PSC-I girder bridge. The objective function was set to the annual cost, which is defined by dividing the total life cycle cost by the service life, and constraints were formulated on the basis of Korean Standards. The optimal design was performed for various service lives and the effects of design factors were investigated.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.244-249
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• 2006

Recently, the SCP(Steel Confined Prestressed concrete) composite girders are developed to improve the characteristic such as displacement, vibration, and heavy dead load due to influence of self weight, and inefficiency of steel section of exiting girder-type railroad bridges. It is needed to verify the economical effciency of newly developed SCP composite girder bridge compared with the conventional girder-type bridges. In this paper, LCC analysis for alternative railroad bridges Is performed and its technique based on level of risk(probability of failure) is suggested. From the results, it may be stated that SCP composite girder bridge is more economical than a conventional one.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.574-580
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• 2005

Recently, the number of bridges and tunnels in railway is increasing due to the super high-speedy of train. Also, because of successively accidents of civil structures such as bridges and dams, the importance of maintenance become influential. The purpose of this study is to show the probabilistic life cycle cost analysis technique(PLCC) of the railroad bridge as pubic-infrastructures, and reasonably to indicate the economy in life cycle cost(LCC) through a case study. Rationally for life cycle cost analysis, the data gathered through many materials considered the uncertainty such as covariance. As a result, it is indicated that prestressed concrete bridge is pretty more cost-effective during life-cycle than preflex as well as steel box bridge. In future, if the construction of database and maintenance materials for railroad infrastructure is actualized, the life cycle cost analysis for railroad can be conducted easily and practically.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1424-1428
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• 2009

The performance of a heat pump using river water as a heat source was compared with that of a conventional air-conditioner for cooling and a boiler system for heating. The heat pump system using river water considered the 1-stage cycle for cooling and the 2-stage cycle for heating. The COPs of the river water source heat pump were $0.5{\sim}1.1$ higher than those of the conventional system in the cooling season. The LCC of the river water source heat pump system was lower 13.5% and 32.4% than that of the conventional system I and II. In addition, when the initial cost ratios of the river water source heat pump system to the conventional system I and II were less than 1.2 and 1.4, respectively, an acceptable payback was found to be less than 5 years.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.62-68
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• 2009

Life Cycle Cost(LCC) is adopted to decide the target of safety level in designing suspension bridges. The LCC are evaluated considering two types of uncertainty; aleatory and epistemic. The nine alternative designs of suspension bridge are simulated to decide the safety level which can minimize the LCC. The LCC is calculated through the probability of failure and safety index including the uncertainty. This method results in the useful tool deciding the optimum safety level with minimal LCC as the main design factor.

• Journal of Labour Economics
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• v.43 no.3
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• pp.123-148
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• 2020

This study empirically estimates the possible association between the college graduate Young Peoples' wages in the labor market and their internal migration through college education after high school education. Using the Graduate Occupation Mobility Survey(GOMS), we found out that the more likely young peoples find jobs in the location from different their hometown the higher they command wages in the labor market.

• 월간 기계설비
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• s.306
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• pp.94-98
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• 2016

300억원 이상의 국가 및 공공기관 발주공사에 대해 최저가낙찰제를 대신하여 종합심사낙찰제 전면 실시 등의 내용을 담은 국가계약법 시행령이 개정되어 2016년 1월 1일부터 시행에 들어갔다. 종합심사낙찰제는 가격 뿐만 아니라 공사수행능력, 사회적책임을 종합 평가하여 낙찰자를 선정하는 제도로 기존의 최저가낙찰제에서 발생한 덤핑낙찰 및 이로 인한 잦은 계약변경, 부실시공, 저가하도급, 임금체불, 산업재해 증가 등의 문제점을 해소하기 위해 도입된 제도이다. 종합심사낙찰제 도입에 따라 공사 품질이 제고됨으로써 생애주기(lifecycle, 유지보수비용 등을 포함) 측면에서의 재정효율성 제고를 비롯하여 불공정 하도급 관행 개선 등 건설산업의 생태계 개선과 함께 시공결과에 책임짐으로써 기술경쟁 촉진 등 건설산업의 경쟁력 강화 효과도 기대된다. 또한 국가계약예규도 개정되어 주계약자관리방식에 의한 공동계약(주계약자 공동도급)이 최저가낙찰제에서 종합심사낙찰제로 전환됐다.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.61-71
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• 2008

An advanced model for assessing life cycle cost of the facility containing several subdivisions has been proposed with systems engineering approach. This model evaluates the maintenance cost in the sphere of the safety as well as in that of its functionality. The proposed approach has been shown to be more reasonable and practical than existing models. The serviceability and reasonability have been proved through evaluating life cycle cost of the reservoir which is a representative agricultural facility. In addition, the proposed method is helpful to make a maintenance strategy using the survival probability in the point of safety and functionality.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.201-210
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• 2001

In this study, large-scale distributed design approach for a life cycle cost (LCC) optimization of steel box girder bridges was implemented. A collaborative optimization approach is one of the multidisciplinary design optimization approaches and it has been proven to be best suited for distributed design environment. The problem of optimum LCC design of steel box girder bridges is formulated as that of minimization of the expected total LCC that consists of initial cost maintenance cost expected retrofit costs for strength, deflection and crack. To discuss the possibility of the application for the collaborative optimization of steel box girder bridges, the results of this algorithm are compared with those of single level algorithm. From the numerical investigations, the collaborative optimization approach proposed in this study may be expected to be new concepts and design methodologies associated with the LCC approach.