• 한국산업정보학회논문지
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• 제7권1호
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• pp.66-74
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• 2002

판매되는 제품에 대한 보증비용은 소비자의 사용정도에 관계없이 일정하다고 가정한다. 하지만 현실적으로는 소비자들에 따라 사용 정도가 서로 다를 수 있다. 사용정도와 예방보수 형태는 보증비용 책정에 중요한 역할을 할 수 있다. 따라서, 본 논문에서는 소비자에 따라 사용정도가 다르고 예방보수 정책의 형태가 서로 다른 경우에 대한 제품의 기대보증 비용을 산출할 수 있는 새로운 보증비용 모형을 제시했다.

• 전기학회논문지
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• 제62권11호
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• pp.1511-1519
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• 2013

This paper proposes the allocation method for capacitor-reactor banks in a distribution system with dispersed generators to reduce the installation costs, the maintenance costs and minimize the loss of electrical energy. The expected lifetime and maintenance period of devices with moving parts depends on the total number of operations, which affects the replacement and maintenance period for aging equipment under a limited budget. In this paper, the expected device lifetimes and the maintenance period are included in the formulation, and the optimal operation status of the devices is determined using a genetic algorithm. The optimal numbers and locations for capacitor-reactor banks are determined based on the optimal operation status. Simulation results in a 69-bus distribution system with the dispersed generator show that the proposed technique performs better than conventional methods.

• 조명전기설비학회논문지
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• 제15권5호
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• pp.1-7
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• 2001

조명시스템의 경제성에 크게 영향을 주는 요소들을 보면 초기 설비비, 보수비, 전기요금 등이 있다. 이 중에서 보수비는 램프 교환비, 램프교환 인건비, 청소비로 구성되어 있으므로 부소계획에 따라서 조명시스템의 경제성이 다르게 나타난다. 따라서 설계초기에 어떠한 조명시스템이 경제적으로 유리한가를 예측하는 것은 중요하다. 그러므로 본 연구에서는 평균조도를 계산하는데 사용되는 ZCM에서의 보수율 구성 요소들을 변화시켜 보수율을 산정한 다음 조명시스템의 경제성을 평가하여 보수율의 중요성을 보였다.

• 한국건축시공학회지
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• 제9권2호
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• pp.103-110
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• 2009

Recently, maintenance of public rental housing becomes a critical issue because its expenditure possesses the majority proportion of life cycle cost. The countries, such as USA and Singapore, have introduced the approaches for advanced property management, which are cost-effective in the maintenance management. However, as maintenance management system becomes advanced, risks associated with its application are also increased. Therefore, it is needed to assess the appropriate applicability of public rental housing maintenance management considering the constrains in domestic construction industry. The main objective of this study are to investigate international cases and systems and to propose strategic introduction, which satisfies the regulations and policies for domestic public rental housing. In order to evaluate the suitability of the investigated systems, practitioners' opinions were reviewed through the questionnaire surveys using analytic hierarchy process (AHP). The surveys indicate that advanced asset management was the suitable process for managing efficiently domestic public rental housing. Moreover, the results showed each weights of considerable criteria for assessing the effective application of maintenance management, and would contribute to further detailed and systematic management.

• 산업경영시스템학회지
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• 제45권3호
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• pp.18-30
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• 2022

Predicting remaining useful life (RUL) becomes significant to implement prognostics and health management of industrial systems. The relevant studies have contributed to creating RUL prediction models and validating their acceptable performance; however, they are confined to drive reasonable preventive maintenance strategies derived from and connected with such predictive models. This paper proposes a data-driven preventive maintenance method that predicts RUL of industrial systems and determines the optimal replacement time intervals to lead to cost minimization in preventive maintenance. The proposed method comprises: (1) generating RUL prediction models through learning historical process data by using machine learning techniques including random forest and extreme gradient boosting, and (2) applying the system failure time derived from the RUL prediction models to the Weibull distribution-based minimum-repair block replacement model for finding the cost-optimal block replacement time. The paper includes a case study to demonstrate the feasibility of the proposed method using an open dataset, wherein sensor data are generated and recorded from turbofan engine systems.

• 한국도로학회논문집
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• 제8권2호
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• pp.49-54
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• 2006

The purpose of this study was to determine the effect of expansion joint spacing (slab size) on the life cycle costs of owning Portland Cement Concrete (PCC) airfield pavements. Previous research has shown that slab size has a statistically significant impact on pavement performance. A probabilistic life cycle cost analysis was performed to determine if the effect of slab size on pavement performance would affect the total cost of ownership of PCC pavements. Data from 48 Pavement Condition Index (PCI) inspections of military and civilian airfields were used to develop probability-of-distress-by-condition curves, which were then used to develop probabilistic cost-of-repair-by-condition curves. A present worth life cycle cost analysis was then performed for various slab sizes, using construction costs, rehabilitation costs, and maintenance costs. Maintenance costs were determined by assuming a condition deterioration rate appropriate for each slab size and applying the cost-by-condition curves. The probabilistic cost-of-repair-by-condition curves indicated that smaller slabs are more expensive to repair on a unit cost basis. Life cycle cost analysis showed that larger slabs have a higher total cost of ownership than smaller slabs due to a faster rate of deterioration.

• 한국국방경영분석학회지
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• 제28권1호
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• pp.97-114
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• 2002

An estimation of economic life for a new weapon system is a critical issue in aquisition process. In general a life cycle cost consists of, development cost, aquisition cost, and maintenance cost. These costs are not identified and obtained in the beginning of the aquisition process. This paper deals with an economic life for KlAl tank which is being deployed recently, using PRICE model. In order to estimate an KlAl economic life, we use equivalent annual cost method which is sum of capital recovering with return and equivalent O&M cost method. This method determines an economic life by minimizing annual investment cost and operation and maintenance cost. In this paper, an aquisition cost of KlAl is obtained from PRICE H and O&M cost from PRICE HL model. We obtained various results depending upon production quantity. An economic life for KlAl is estimated 18 years when 300 tanks are produced.

• 한국도로학회논문집
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• 제18권4호
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• pp.19-28
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• 2016

PURPOSES : Long-life asphalt pavements are used widely in developed countries. In order to be able to devise an effective maintenance strategy for such pavements, in this study, we evaluated the performance of the long-life asphalt pavements constructed along the national highways in South Korea. Further, an economic evaluation of the long-life asphalt pavements was performed based on a life-cycle cost analysis. We aimed to devise a model for evaluating the performance of long-life asphalt pavements using the national highway pavement management system (PMS) database as well as for analyzing the economic feasibility of such pavements, in order to promote their use in South Korea. METHODS : The maintenance history and pavement performance data were obtained from the national highway PMS database. The pavement performances for a total of 292 sections of 10 lanes (5 northbound lanes and 5 eastbound lanes) of national highways were used in this study. Models to predict the performances of hot mix asphalt (HMA) and long-life asphalt pavements under two distinct traffic conditions were developed using a simple regression method. Further, the economic feasibility of long-life asphalt pavements was evaluated using the Korea Pavement Management System (KoPMS). RESULTS : We developed service-life prediction models based on the traffic volume and the equivalent of single-axle load and found that long-life asphalt pavements have service lives 50% longer than those of HMA pavements. Further, the results of the economic analysis showed that long-life asphalt pavements are superior in terms of various economic indexes, including user cost, delay cost, total cost, and user benefits, even though their maintenance cost is higher than that of HMA pavements. A comparison of the economic feasibilities of the various groups showed that group A is superior to HMA pavements in all aspects except in terms of the maintenance criterion (crack 20% or higher) as per the NPV index. However, the long-life asphalt pavements in group B were superior in terms of the maintenance criterion (crack 25% or higher) regardless of the economic feasibility. CONCLUSIONS : The service life of long-life asphalt pavements was found to be approximately 50% longer than that of HMA pavements, regardless of the traffic volume characteristics. The economic feasibility of long-life asphalt pavements was evaluated based on the KoPMS. The results of the economic analysis were the following: long-life asphalt pavements are exceptional in terms of almost all factors, such as user cost, delay cost, total cost, and user benefit; however, the exception is the maintenance cost. Further, the economic feasibility of the long-life asphalt pavements in group B was found to be better than that of the HMA pavements (crack 25% or higher).

• 한국철도학회논문집
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• 제20권2호
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• pp.275-287
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• 2017

신규 철도노선의 건설을 위한 타당성 검토시 관련 유지보수비용은 궤도연장을 기반으로 여러 요인을 단순화하여 예측하고 있으나 UIC 714의 선로등급 및 UIC 715의 유지보수비용 영향요인 개념을 반영하는 경우, 비용산정결과의 신뢰도를 향상시킬 수 있다. 따라서 본 연구에서는 국내외 사례를 기초로 유지보수비용과 선로등급에 따른 가중 철도연장, 곡선반경, 종단경사 및 노후도 등과의 상관관계를 분석하였다. 이를 위하여 유지보수 위탁기관의 각 지역본부별 유지보수비용 중 대표성이 있는 자료를 기반으로 비용예측을 수행하였으며, 이 결과 기존노선의 선로등급 및 등급별 비용계수에 따른 유지보수비용 산정방안이 기존 적용방법에 비해 합리적임을 밝혔다. 또한 현재 개발중인 고속 종합검측차의 검측데이터 및 철도시설물의 이력정보를 고려한 비용산정 방안을 함께 고려하였으며 이를 기반으로 선로등급, 곡선반경, 노후도 및 선로 기울기 등을 종합적으로 고려한 유지보수비용 산정모델의 개발이 가능할 것으로 예상된다.

• 한국항행학회논문지
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• 제20권6호
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• pp.511-518
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• 2016

본 연구는 RAPCON을 구성하는 구성요소를 체계별로 구분하고 체계별 운영시간 에 따른 고장율 등을 분석한다. 아울러 설계수명에 점차 도달한 RAPCON의 운영 중 발생한 유지보수비용 데이터를 토대로 남은 설계수명 기간 동안 향후 발생 가능한 유지보수 비용을 추정한다. 이런 분석결과를 통해 장비의 신뢰성 관련 선행연구들에서 주로 인용되고 있는 욕조커브 (bathtub curve) 이론과 본 연구의 비용예측 결과와의 연관성을 진단하고 안정적인 유지보수를 위한 기초자료로서 활용되고자 한다. 본 시계열 분석에 사용된 자료는 T국 공군이 구형 RAPCON을 신형으로 교체하면서, 설계수명이 다된 기존 RAPCON 운영단계에서 발생했던 50개월의 유지보수비용 데이터이다. 유지보수 비용은 6개 체계별 유지보수비용을 합한 월별 유지보수비용으로 사용하였다. ARIMA 모형을 토대로 향후 10개월 간 발생 가능한 유지보수 비용을 예측한 결과 비용이 상승할 것이라는 통계적으로 신뢰할 만한 추정 결과를 얻었다.