• 대한전기학회논문지
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• 제41권1호
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• pp.9-17
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• 1992

Proper resource allocation is also a very important topic in power system problems, especially in operation and planning. One such is optimal maintenance problem in operation and planning. Least cost and highest reliability should be the subjects to be pursued. A probabilistic operation simulation model developed recently by authors is applied to the proboem of optimal maintenance scheduling. Three different methods are compared, marginal maintenance cost, levelized risk and maintenance space. The method by the marginal maintenance costs shows the least cost, the highest reliability and the highest maintenance outage rates. This latter characteristics may considerably influence the results of genetation planning, because the usual maintenance outages obtained from the other methods have shown to be lower.

• 전기학회논문지
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• 제57권8호
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• pp.1305-1310
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• 2008

Traditional maintenance planning is based on a constant maintenance interval for equipment life. In order to consider economic aspect for time based preventive maintenance, preventive maintenance is desirable to be scheduled by RCM(Reliability-Centered Maintenance) evaluation. The main objective of RCM is to reduce the maintenance cost, by focusing on the most important functions of the system and avoiding or removing maintenance actions that are not strictly necessary. So, Markov state model is utilized considering stochastic state in RCM. In this paper, a Markov state model which can be used for scheduling and optimization of maintenance is presented. The deterioration process of system condition is modeled by the stepwise Markov model in detail. Also, because the system is not continuously monitored, the inspection is considered. In case study, simulation results about RCM will be shown using the real historical data of combustion turbine generating unit in Korean power systems.

• 소음진동
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• 제4권4호
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• pp.459-467
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• 1994

Various maintenance programs and techniques have been implemented for roating machineries, since machines were invented for commerical use. The earliest type of maintenance was run-to-failure, where the machine was run until a fault caused to fail in service. It was obviously an expensive approach due to the unpredictability of the machine condition. Another type is the periodic maintenance, where machines are disassembled and overhauled on regular schedules. With the advent of reliable data collectors including FFT analyzer and developing of versatile supporting software such as ExpertALERT system, the predictive maintenance is known to be the most feasible maintenance type these days. The vibration analysis enables for a maintenance crew to find the exact cause of fault on a machine and to make a proper maintenance schedule with a trend analysis. The predicitive maintenance is considered to be the most important part of pro-active maintenance.

• 항공우주시스템공학회지
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• 제14권6호
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• pp.36-43
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• 2020

The purpose of this study is to present the internationalization of South Korea's aircraft maintenance certificate for mutual recognition of aircraft maintenance license qualifications among various countries in preparation for an internationalization of the work conducted by the aviation industry. To achieve this objective, this study reviews the aircraft maintenance license training system and compares the standards for aircraft maintenance certification established by the Convention on International Civil Aviation with the standards for issuing domestic aircraft maintenance licenses. This comparative analysis shows that the domestic curriculum of aircraft maintenance licenses differs from international standards. As a result of this study, an improvement plan of the education content was proposed to enable the licensing qualifications of domestic aircraft maintenance licenses to be mutually recognized among different countries.

• 한국산학기술학회논문지
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• 제22권6호
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• pp.477-483
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• 2021

군의 정비체계에서 표준정비인시는 정비부대의 정비능력을 판단하는 도구로서 정비 소요와 작업량을 결정하는 기준을 제공하고, 정비계획 수립의 기초 자료로 활용된다. 군 주요 장비의 평시 표준정비인시는 이미 선정되어 활용하고 있으나 전시 정비환경에서 표준정비인시는 미선정되어 이를 산출할 필요성이 제기되었다. 이는 전시에 정비 시설, 공구, 장비, 인력 등이 충분치 않고, 정비 목표와 수준이 평시와는 상이하므로 평시 표준정비인시를 직접 적용하는 것은 적절하지 못하기 때문이다. 따라서 본 연구는 전시 표준정비인시 산정을 위해 필요한 데이터를 수집·선별하는 과정과 기준을 제시하고, 표준정비인시 산출 프로세스에서 정비인시 분포의 특징을 분석하여 표준정비인시로서의 대푯값을 선정하는 방법을 제안한다. 제시되는 전시 정비인시 산출 프로세스는 먼저 전시 정비환경을 고려한 기준과 가정사항 등을 반영한 모델을 설계하고, 표준정비인시 도출의 통계적 기법을 결정하며, 전시와 유사한 환경의 평시 정비실적 데이터를 수집하여 기술통계 분석과 정비인시 분포를 추정 및 검증하고 최종적으로 대푯값을 제시하는 방법을 사용한다. 제안된 방법을 토대로 육군이 운용 중인 4개 주요 전투장비의 전시 표준정비인시를 도출하였으며, 해당 장비들의 정비인시 분포가 로그 정규분포를 따르고 있는 것으로 분석되어 신뢰성 있는 결과값을 제시하였다.

• 한국조경학회지
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• 제29권5호
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• pp.1-19
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• 2001

This paper is designed to find and develop new concepts for the sustainable traditional village in Korea. To this end, it is necessary that concern for the traditional village should diversify and expand, and not concentrate solely on the cultural properties and architecture-oriented historic elements. In consideration of this notion, this paper suggests introduction of maintenance and management as a practical concept for the embodiment of the sustainable traditional village. This paper aims to explore the concrete maintenance and management systems of Korean and Japanese cases, to analyze differences and characteristics between the two nation\\\\`s, and through these comparisons, to suggest sustainable maintenance and management methods for the traditional village in Korea. Primary data was collected by field and interview survey on each village in the two nations several times during about a two year period. The major findings of this paper are presented in three categories--maintenance management frame, maintenance management contents, and necessary principles for progressive maintenance management, and are as follows; In the first step, suggests the basic directions, boundaries, and systems for the maintenance and management of sustainable traditional villages. And in the second step, analyzes the relationship among the contents of maintenance and management methods with focus on the village space, village attraction, and village community. Our results suggests diverse maintenance and management contents for the sustainable village maintenance and management. Finally, the basic principles for the application, and use as valuable tools for sustainable village maintenance and management, are strongly recommended.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.234-235
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• 2015

In South Korea, small photovoltaic equipment is increasingly adopted in more detached houses on the constant basis. With this broader use of small photovoltaic equipment, its systematic maintenance becomes all the more necessary. However, photovoltaic facility maintenance has been concentrated solely on large-scale solar energy generation plants in the country while hardly covering smaller facilities. In this research, the JEM rule and extant maintenance company services were analyzed to develop a proper maintenance model for small photovoltaic equipment. The maintenance service procedures designed herein are as follows: A small photovoltaic equipment user chooses a maintenance company and signs a contract. Once a contract is made, the Korea Energy Management Corporation provides a certain kind of incentive to the company. The company provides maintenance service to the user and receives a service fee. If such a maintenance service model is in place, small photovoltaic equipment efficiency is expected to increase and users could receive systematic maintenance services. Also the new creation of small photovoltaic equipment maintenance service would form a new market to generate more jobs for the society.

• 한국IT서비스학회지
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• 제14권3호
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• pp.67-84
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• 2015

Software is more diverse and complex and the level of importance for the maintenance of application software to securely operate software is also gradually increasing in proportion. The calculation method for maintenance cost of application software applied in Korea public enterprises is involved in the range of 10 to 15% of development cost, depending on the Software Project Cost Estimation Guide. Moreover, as most software maintenance cost estimation procedures do not take into consideration of the risk factors related of maintenance, it can be seen as a main cause for the occurrence of maintenance related accidents. This study proposes a maintenance cost estimate model that takes into consideration of the risks related to the software maintenance activities to improve and resolve issues arising from the estimation of maintenance cost. In doing so, maintenance risk factors are analyzed and a risk index is derived through the analysis of risk levels based on the risk factors. Based on such analysis, a maintenance cost estimate method which reflects the maintenance risk index was established.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.25-31
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• 2011

The purpose of power system maintenance is to prevent equipment failure. The maintenance strategy should be designed to balance costs and benefits because frequent maintenance increases cost while infrequent maintenance can also be costly due to electricity outages. This paper proposes maintenance modeling of a power distribution system using reliability centered maintenance (RCM). The proposed method includes comprehensive equipment modeling and impact analysis to evaluate the effect of equipment faults. The problem of finding the optimum maintenance strategy is formulated in terms of dynamic programming. The applied power system is based on the RBTS Bus 2 model, and the results demonstrate the potential for designing a maintenance strategy using the proposed model.

• Tuberculosis and Respiratory Diseases
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• 제76권1호
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• pp.1-7
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• 2014

Maintenance therapy has emerged as a novel therapeutic paradigm for advanced non-small-cell lung cancer (NSCLC). Maintenance therapy that aims to sustain a clinically favorable state after first-line chemotherapy has two strategies. Switch maintenance therapy entails switching to a new and non-cross-resistant agent in an alternating or sequential manner, on completion of first-line chemotherapy. Continuous maintenance therapy keeps ongoing administration of a component of the current regimen after four to six cycles of chemotherapy, if there is a stable disease, or better response. Both maintenance therapies can be continued, until disease progression. The potential evidence regarding maintenance therapy includes providing the opportunity to receive additional treatment, through sustaining tumor shrinkage, and delayed emergence of tumor-related symptom. Thus far, debates over the parameters used to predict the effectiveness of maintenance therapy, financial burden, and uncertainty of improving the quality of life exist. Despite many debates, maintenance therapy, which is currently recommended, has been disclosed to be beneficial.