• Journal of the Korean Data and Information Science Society
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• 제27권6호
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• pp.1557-1564
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• 2016

최근에 기본보증이 종료된 이후에 주어지는 시스템의 추가보증에 대한 사용자의 관심이 증가되고 있다. 따라서 본 논문에서는 사용자 측면에서 비재생보증 하에서의 이단계 보전정책을 제안하였다. 이단계 보전정책의 첫 번째 단계에서는 추가보증을 구입할 것인지의 여부를 결정하고, 두 번째 단계에서는 보증이 종료된 이후의 최적의 교체 주기를 결정한다. 이때, 추가보증 동안에 발생된 시스템의 고장에 대해서는 판매자에 의해서 무료로 최소수리가 이루어진다. 최적의 이단계 보전정책을 결정하기 위해서 사용자 측면에서 기대비용을 사용하였으며, 끝으로 시스템의 고장시간이 와이블 분포를 따를 때 수치적 예를 통하여 제안된 이단계 보전정책을 설명하였다.

• 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.

• 품질경영학회지
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• 제30권3호
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• pp.53-65
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• 2002

This paper studies an economic manufacturing quantity (EMQ) model with two types of failures and planned preventive maintenance of the production facility. One is a type I (major) failure which should be corrected by a failure maintenance and the other is a type H (minor) failure which can be minimally repaired without interrupting the production run. The objective is to determine the lot size and preventive replacement policy minimizing the long-run expected cost per unit time. We consider a control policy with a constant production lot size and preventive maintenance after completing n production runs. It is assumed that both preventive and failure maintenance times are random and the demand arriving during a stock-out period is lost. An expression for the expected cost per unit time is obtained in the general case. A special case is discussed and numerical results are provided.

• 한국경영과학회지
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• 제25권3호
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• pp.41-48
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• 2000

We consider the question of warranties for repairable items. During the warranty period, each time an item fails the manufacturer has the obligation to restore the item to operational condition either by repairing the item or by replacing it by a new item. In this paper, we consider a warranty policy for making this decision based on the condition of the failed item. For products with phase-type lifetime distributions where the phases represent the condition of the item, we develop algorithms to determine the expected cost of servicing a warranty and use it in making the repair/replacement decision. illustrative numerical examples are presented.

• 한국신뢰성학회지:신뢰성응용연구
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• 제5권3호
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• pp.381-391
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• 2005

The level of reliability attained largely depends upon the investment in reliability growth programs during development phase. In order to find the relationship between reliability growth test time and BRTE(basic reliability tasks effectiveness) in a reliability improvement program that minimizes LCC in which contains the reliability growth cost, repair and replacement costs, and spare parts ordering costs in service with given service rate in management policy, the growth rate has been suggested proper LCC versus growth rate. This model employs the reliability growth projection with delayed fixes in avionic equipment based on AMSAA.

• 대한산업공학회지
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• 제14권2호
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• pp.81-90
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• 1988

This paper is concerned with warranty cost models for a product with two types of failure ; type 1 failures corrected by minimal repair and type 2 failures removed only by replacement. Two warranty policies involving an initial free service period followed by a pro-rata period are considered ; the difference is whether the warranty is renewed or not when type 2 failure occures during its free service period. Expected warranty costs under the two policies are obtained, and their behaviors are examined for the case where type 1 and 2 failure distributions are Weibull and exponential, respectively.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.386-397
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• 2007

One major development in bridge life cycle cost analysis (LCCA) in recent years is to develop deterioration model for bridge components so that the times of repair/replacement throughout a component's life span can be properly determined. Taiwan also developed her own bridge LCCA model in 2003, integrating with the bridge inspection database in the local bridge management system (T-BMS). Under the framework of the local LCCA model, this study employs the reliability method in developing a deterioration model of bridge components. A component deteriorates through time in its reliability, which represents the probability of a component's condition index exceeds a user specified threshold. Model assumptions and rationale are described in the paper. The steps for applying the developed model are explained in detail. Results and findings are reported.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.720-723
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• 2004

This study is intended to propose a systematic approach for determining optimum Life-Cycle Cost (LCC)-effective seismic design for continuous PSC bridges considering lifetime expected seismic risks. In the paper, a set of cost function for LCC analysis of bridges is proposed. The total LCC functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect socio-economic losses. The damage costs are expressed in terms of Park-Ang median global damage indices (Park and Ang, 1985) and lifetime damage probabilities. The proposed approach is applied to model bridges of both moderate seismicity regions like Korea and high seismicity regions like Japan. Since, in case of bridges, a number of parameters may have an influence on optimal target reliability, various sensitivity analyses are performed in this study. It may be expected that the proposed approach can be effectively utilized for the development of cost-effective performance criteria for design and upgrading of various types of bridges as well as continuous PC bridges.

• 한국건축시공학회지
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• 제20권4호
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• pp.375-382
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• 2020

국내 국경 지역의 주요 도로에 낙석 장애물을 설치, 운영하여 적군의 이동을 방지하고 차단하고 있다. 그러나 접경지역의 개발로 인한 교통량 증가는 낙석으로 인한 도로 교통 혼잡, 교통 안전, 도시 미관 저하 등 많은 문제를 야기하고 있다. 따라서 본 연구는 단위별로 다르게 적용되는 낙석장해물 철거 및 교체 시설 설치 지침을 제공하고, 운영에 필요한 낙석 장해물 유지비에 대한 국방부의 정책 방향을 제시하고자 하였다. 본 연구에서는 낙석 장해물 제거 및 대체시설 설치에 관한 지침 연구의 일환으로 필수 낙하 장해물에 대한 표준 단가를 제시하여 암석 제거 여부를 판단 할때 판단 자료로 활용하고자 하였다.

• 콘크리트학회논문집
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• 제29권1호
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• pp.3-10
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• 2017

내 공용중인 고속도로의 60%는 콘크리트로 포장이 되어 있으며, 그중 50% 이상의 도로가 설계 수명 이상 사용으로 인해 포장 손상, 줄눈부 파손, 부분 탈락 등의 다양한 문제가 발생하고 있다. 하지만 기존 도로 구조물의 보수보강은 높은 비용과 그로인한 복잡한 유지관리가 발생하므로 경제적인 보수보강 재료의 개발이 시급하다. 본 연구에서는 도로보수재료로서 기초물성 평가를 위해 칼슘 알루미나 시멘트에 OPC를 무게 대비 0, 10, 20%로 혼입한 재료를 적용하여 응결시간, 압축강도, 휨강도를 측정하였다. 그 결과, 최소물성 기준 및 재료 단가 측면을 고려하였을 때 20% OPC의 경우가 최적배합임을 도출하였다. 또한 일반적인 보수재료들을 이용한 특정 도로의 공사비용 산정을 위해, 상용 프로그램(CA4PRS)을 사용하여 경제성 분석을 실시하였다. 그 결과 20% OPC의 경우 총 시공 및 이용자 비용으로 각각 40.52, 15.77억 원이 발생하였으며, 총합으로 비교 시 가장 경제성이 높은 재료로 판단되었다.