• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.1
• /
• pp.58-65
• /
• 2008

Reliability-Centered Maintenance plan for maintenance schedule of generating unit is being assessed in this paper. Maintenance schedule is a key index that can be used to determine stability and cost. In this paper, stochastic FMECA is described for the life assessment by using probability distribution, and combustion-turbine generations in Korean power systems have been assessed for maintenance schedule. Such an assessment can be a useful guide for maintenance plans in restructured power industry.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.6 no.5
• /
• pp.29-36
• /
• 2002

In the maintenance and retrofit planning of a bridge system, the optimal strategy for inspection and repair are suggested by minimizing the expected total life-cycle cost, which includes the initial cost, the costs of inspection, repair, and failure. Degradation of seismic performance is modeled by using a damage function. And failure probability is computed according to the degree of damage detection by random vibration theory and the event tree analysis. As an example to illustrate the proposed approach, a 10-span continuous bridge structure is used. The numerical results show that the optimum number of the inspection and the repair are increased, as the seismic intensity is increased and the soil condition of a site becomes more flexible.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2A
• /
• pp.223-231
• /
• 2008

This research presents a new maintenance planning method for deteriorating bridges considering simultaneously the minimization of the maintenance cost and maximization of the bridge performance. Optimal maintenance planning is formulated as a multi-objective optimization problem that treats the maintenance cost as well as the bridge performance such as the condition grade of the bridge deck, girder and pier. To effectively address the multi-objective optimization problem and decision making process for the obtained solution set, we apply a genetic algorithm as a numerical searching technique and adopt a preference-based optimization method. A numerical example for a typical 5-span prestressed concrete girder bridge shows that the maintenance cost and the performance of the bridge can be balanced reasonably without severe trade-offs between each objectives.

• Journal of the Korean Society for Railway
• /
• v.13 no.6
• /
• pp.601-607
• /
• 2010

The objective of this paper is to propose a fast and easy Binary Artificial Bee Colony (BABC) heuristic algorithm to optimize NP-hard scheduling problem of railway track maintenance considering real conditions. The optimal or best solutions can be found using proposed BABC within very short or user specified computation time. We can greatly maximize the objective value using this proposed method in 30, 60, 100 and 200 work size railway track maintenance scheduling problems for experiment and analysis.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.7 no.5
• /
• pp.77-85
• /
• 1997

A new technique using integer programming based on fuzzy multi-criteria function is proposed for generator maintenance scheduling. Minimization of maintenance delay cost and maximization of supply reserve power are considered for fuzzy multi-criteria function To obtain an optimal solution for gen- ,:rator 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 conaitraints with uncertainty can be taken into account by using fuzzy set theory and so more flexible solution Ian he obtained. The effectiveness of the proposed approach is demonstrated by the simulation results.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.1012-1017
• /
• 2004

노후된 상수도 관망의 최적개량 계획수립을 위하여 국내에서 가장 많이 쓰이는 모형은 관거의 교체, 갱생, 유지보수 비용 등과 같은 인자를 이용한 경제성분석에 의한 모형이다. 국내 적용된 대부분의 모형은 Shamir 등(1979)의 모형을 근간으로 하고 있으나, 모형에서 사용되는 여러 인자 중 관거의 유지보수 비용에 대한 국내 연구는 미비한 실정이다. 본 연구에서는 6년간의 대구광역시 지역의 누수보수기록자료를 이용해 국내 적용 가능한 유지보수 비용 함수를 유도하였다.

• Proceedings of the KIEE Conference
• /
• 2004.05b
• /
• pp.88-90
• /
• 2004

설비의 가용성 및 신뢰성 증대와 보수 정비 비용 절감에 대한 관심이 증대되면서 전력시스템의 유지보수에 대한 관심이 증대되고 있다. 계획에 없는 유지보수와 예상치 못한 정전 등을 최소화시키면서 전체설비의 활용도와 신뢰도를 증가시키는 방법에 대한 요구가 커지고 있는 것이다. 기존의 계획기반의 유지보수에서 최근 도입되고 있는 상태 감시기반의 유지보수는 설비의 상태를 감시, 분석하여 유지 보수함으로써 진일보되었으나, 기술적, 비용적인 문제로 전면적인 도입이 힘든 상황이다. 따라서 각 설비의 특성 파악과 운용 환경에 따른 설비의 중요도 및 파급효과 분석을 통해 가장 효율적이고 경제적인 유지보수 기법을 결정하는 신뢰성 기반의 예방진단 기법인 RCM의 적용에 관한 분석사항 등을 살펴보았다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.12
• /
• pp.303-312
• /
• 2018

The university facility is made up of multiple buildings and has many maintenance items. In addition, administrative constraints need to be handled within a limited period. Most maintenance work is small scale and multi-work construction, such as waterproofing, needs to be organized. The facility manager makes annual unit price contract with a maintenance company and carries out the maintenance work. On the other hand, delay and rework is occurring because existing maintenance work performed without scheduling based on the manpower input. This study proposed a scheduling model that can support the facility manager to manage maintenance works of multiple university facilities at the program level. The model consists of three stages in order. In object analysis, details of the maintenance items were analyzed and the quantity is calculated based on the quantity takeoff sheet. In resource analysis, the craftsmen and construction period of detailed works are derived for the effective input of craftsmen. In scheduling, the priority of each work and the optimal manpower input are derived. The optimal schedule is selected according to the goodness of fit. The applicability and effectiveness of the prototype was evaluated through a case study and interviews with case participants. The model was found to be an effective tool to support the scheduling of maintenance works for the facility manager.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.705-706
• /
• 2007

전력 산업구조 개편이 진행됨에 따라 배전부문에는 독립사업부제를 도입하게 되었다. 각 사업부들은 타 사업부와의 경쟁을 경험하게 된다. 배전사업부들은 효율성을 높이기 위해 노력할 것이다. 즉, 최소의 비용으로 최대의 효과를 얻을 수 있는 방법을 개발하기 위해 노력할 것이다. 배전계통 운영에 많은 부분을 차지하는 유지보수에 대해서, 비용은 줄이고 효율성을 높이는 방향을 선택할 것이다. 이에 본 논문에서는 유지보수 기법 중 하나인 RCM 기법을 이용한 유지보수 계획 수립시 고려해야 할 전반적인 사항에 대해 고찰하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.4
• /
• pp.367-374
• /
• 2002

Maintainability of highways is an important problem that is considered in the planning steps of a highway development process. A number of asset management systems have been developed to precisely predict maintenance and pavement expenditures for better decision making, But these systems are not helpful in reducing maintenance costs. Optimization of some highway design characteristics in the planning phases may reduce maintenance costs over the life cycle of highway. The formulations for initial and maintenance costs have been developed based on which design variables can be chosen to minimize these costs, focusing on the sideslope in cut and fill sections. Maintenance cost has been represented as a function of sideslope, width of highway cross section, and annual average daily traffic. A real geographic database of between Chung joo and Sang joo city in Choong buk was used and it is presented to investigate the sensitivities of maintenance cost and soil characteristics in selecting alignments. In this study, we present that maintenance cost and soil characteristics are important considerations in alignment optimization.