• Journal of Advanced Marine Engineering and Technology
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• 제24권2호
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• pp.90-96
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• 2000

The technology of preventive maintenance and corrective maintenance is widely applied to ships in order to maintain the good voyageable condition. One of the most important fields of marine engineering is to seek the maximum availability and to solve the stochastic maintenance problem such that the cost for corrective maintenance is minimized. Accordingly, for the purpose of making the most suitable maintenance schedule which minimizes the expected cost function, this paper suggests the method to grasp the failure characteristics by the ship's maintenance data that are collected from the past. And, suggests the method to estimate the optimal maintenance interval by using the dynamic programming and the cumulative hazard rate function attained from the maintenance data.

• 한국국방경영분석학회지
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• 제24권1호
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• pp.98-109
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• 1998

This study develops a maintenance strategy for a reparable 2-unit standby system. The maintenance strategy implies the waiting time to call the repair facility when the unit-1 fails. Almeida and Souza set up the multi-attribute utility function consisting of system availability and repair cost for several maintenance strategies and decide the optimal maintenance strategy that maximize the expected value of the utility function. We decide the optimal maintenance strategy satisfying the following two criteria about the utility function : maximum variance using Almeida and Souza's utility function. It both criteria are not satisfied at the same time for every strategies, the strategy maximizing the lower confidence limit for expected utility function is regarded as an optimal one.

• 한국주거학회논문집
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• 제22권6호
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• pp.51-60
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• 2011

The maintenance cost depends on various factors such as building volume, floor area, number of household and so on. The maintenance cost of the apartment housing is affected by the maintenance type, building physical factor, sociogeographic aspects. Among these, the maintenance characteristics is represented and made up by the total floor area and number of household which means main factor to provide the building scale roughly. In this paper, it aimed at modelling the estimation function of the maintenance cost with the total floor area and number of household and analyzing the elasticity of the two factors. Although items of maintenance cost are various in general cost, repair cost and so on, we classified these items into the 5 categories. 5 categories are a general cost, a facility maintenance cost, a utilization cost, insurance and sanitary cost. The estimation function used a power function and it has better goodness-offitness than any other estimation methods in statistics. A power function has a three curve types with concave and convex and linear style to the origin.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.259-260
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• 2015

In this paper, for deriving core function requirements of facility maintenance using BIM(Building Information Modeling) customized surveys were conducted with 30 facility managers during 6 momths from July 2014. As a result, 19 core function requirements for efficient facility maintenance are drawn. The core of Building facility management function is that opinions of facilities maintenance managers should be fully reflected than that of BIM experts. In the future, the development of maintenance programs based on BIM should be made fully by reflecting the opinions of building facility managers on the basis of this questionnaire survey results.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1528-1533
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• 2009

Infrastructure is provided to the user through long-term project period and large-scale working expenses. Existing facilities are getting old as time goes by. Accordingly, proper maintenance is required and generally more maintenance cost than initial invested cost is needed during life cycle. Therefore, a specific plan that just increases the value of facilities is required by evaluating performance of facilities and inputting minimum maintenance cost. Value engineering that increases the value of object by systemically analyzing Life Cycle Costs and function is actively promoted at the design phase of construction. These efforts can increase the performance of facilities at the maintenance phase of infrastructure. This study is to search how to evaluate the performance of Roadway by utilizing function analysis, as a core part of VE in the maintenance phase. In order to this a new evaluation criteria were proposed by adding an evaluation items to the existing criteria through the research of old documents, status of roadway maintenance and function analysis of VE. The results of this study may promote the effective performance evaluation to determine a resolution of roadway congestion in future. A succeeding study using the proposed evaluation criteria will be required.

• 산업경영시스템학회지
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• 제42권4호
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• pp.145-152
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• 2019

All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.

• 한국전자통신학회논문지
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• 제10권10호
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• pp.1157-1162
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• 2015

태양광 발전소 유지보수 기능은 센서 장치, Gateway, 유지보수 기능 플랫폼으로 구성된다. 본 논문에서는 유지보수 기능에 적합한 게이트웨이 리소스트리와 서비스 시나리오를 설계하고, 지능형 기능 모델링을 통해서 유지보수 서비스가 운영 될 수 있음을 보인다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권5호
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• pp.555-562
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• 2004

소프트웨어 회사들은 새로운 개발보다는 기존 프로젝트의 유지보수와 성능향상 프로젝트를 보다 많이 수행한다. 기존의 비용 추정 모델들은 유지보수 프로젝트들에 적용할 수 있지만, 유지보수 분야에 적용시키기 위해서는 변경이 필요하다. 본 논문은 개발 프로젝트와 유지보수 프로젝트의 기능점수 계산방법을 분류하고 ISBSG의 밴치마킹 자료를 회귀 분석한 결과를 토대로 유지보수 프로젝트의 비용을 측정할 수 있는 방법을 제안하였다. 먼저, ISBSG 자료를 소프트웨어 비용에 영향을 미치는 요소인 프로그램 추가, 변경과 삭제 3가지 요소의 8가지 중에서 실제 유지보수가 나타나는 4가지 그룹으로 분류하였다. 그리고, 그룹별로 통계적 모델과 RBF 망(Radial Basis Function Network)을 이용한 모델을 개발하여 각각의 성능을 분석 평가한 결과 RBF 망이 통계적 모델보다 좋은 성능을 보였다.

• 한국압력기기공학회 논문집
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• 제8권2호
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• pp.26-32
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• 2012

The systems of the nuclear power plant are designed based on the User Requirement Document, and Korea Hydro & Nuclear Power Co. (KHNP) implements preventive maintenance activities to keep the specific design function of the system consistently. To monitor the preventive maintenance effectiveness, KHNP has also developed maintenance effectiveness monitoring (MR) program based on NUMARC 93-01 since 2003, and has implemented the program in all operating plants. Recently, KHNP has upgraded MR programs by reflecting implementing experiences ; reestablishing the performance monitoring level, improving analysis for standby function and performance criteria for passive components, reestablishing the availability performance criteria and the performance criteria for the same type of components. These upgraded MR programs will contribute to enhance safety and improve equipment reliability through monitoring maintenance effectiveness.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1995년도 추계학술대회 학술발표 논문집
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• pp.131-138
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• 1995

A new technique using integer programming based on fuzzy multi-criteria function is proposed for generator maintenance scheduling. Minimization maintenance delay cost and maximization reserve power are considered for fuzzy multi-criteria function. To obtain an optimal solution for generator maintenance scheduling under fuzzy environment, fuzzy multi-criteria integer programming is used. In the maintenance scheduling, a characteristic feature of the presented approach is that the crisp constraints with uncertainty can be taken into account by using fuzzy set theory and so more flexible solution can be obtained. The effectiveness of the proposed approach is demonstrated by the simulation results.