• Journal of the Korean Data and Information Science Society
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• 제22권4호
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• pp.775-784
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• 2011

본 논문에서는 비재생무료교체-수리보증이 종료된 이후의 수리가 가능한 시스템에 대한 주기적인 예방보전모형을 고려한다. 이러한 예방보전모형에 대하여 기대순환길이, 총기대비용 그리고 단위시간당 기대비용을 각각 유도하고자 한다. 또한 유도된 단위시간당 기대비용을 최소화하는 최적의 예방 보전주기와 예방보전횟수를 결정하는 방법에 대하여 자세히 설명한다. 끝으로 고장시간이 와이블분포를 따르는 경우에 최적의 주기적 예방보전정책을 결정하여 본다.

• 풍력에너지저널
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• 제14권3호
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• pp.61-68
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• 2023

This paper aims to perform optimal operation and maintenance with an integrated monitoring system for offshore wind platforms. Based on the wind direction and wind speed data of existing wind farms, a monitoring system was established along with weather and weather data to maximize the operational efficiency of wind farms. Compared to wind power on land, offshore wind power is difficult to maintain due to weather, logistics and geographical limitations. Therefore, economic analysis of actual operation and maintenance is essential for large-scale offshore wind farms. In this paper, the availability of offshore wind farms was analyzed by using personnel resources, parts inventory, Crew Transfer Vessel (CTV) and Specialized service Operation Vessel (SOV) etc. before the actual operation and maintenance of wind farms. A comparative analysis was conducted to determine the optimum operating efficiency and economical maintenance costs.

• 대한물리치료과학회지
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• 제7권2호
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• pp.459-474
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• 2000

The purpose of this study is to identify the posture correction program as the development of the posture maintenance performance, and search for the more efficient posture correction program. The data analysis was processed by SPSS. The data was analysed with $x^2$-test, t-test, pearson product moment correlation, and stepwise regression analysis. The finding of this study is as follows: There are the homogeneity between two groups was verified on the know ledges CF=.697, df=2, P>.05), self-efficacy(F=.098, df=2, P>.05) about the posture. The developed posture correction program has proved to enhance the posture maintenance performance(knowledge t=1.60, P<.05 ; posture manintenance t=7.69, P<.01). The type of posture correction program showed some significant differences (t=5.62, P<.01) in the accuracy of movement way among the factors of the posture maintenance performance. The posture maintenance performance affected self-efficacy. Therefore, the major conclusion is as follows: The posture correction program was meaningfully effective on developing the posture maintenance, and with practice created accuracy much more on the posture maintenance movement way. The development of the posture maintenance performance affected the increase of self-efficacy about the posture. The self-efficacy has proved so powerful factor to influence on the posture maintenance performance development. So, the posture correction program should be done systematically and continually, and developing the posture maintenance performance should be done with practice. After the education, it should be reinforced through practice, midterm identification and reeducation and motivated with recognizing the accurate posture measurement. And it should be created the correction program to develop the high self-efficacy about the posture. It needs the strategy to educate the correct posture individually, and to spread to the society for healthy life style.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.367-377
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• 2006

This paper develops a periodic preventive maintenance(PM) policy following the expiration of warranty. Two types of warranty are considered: renewing warranty and non-renewing warranty. Also, we consider the situation where each PM cost is an increasing function of the PM effect. We determine the optimal number of PM's before replacing the system by a new one and the optimal length of period for the periodic PM following the expiration of warranty. Explicit solutions to determine the optimal periodic PM are presented for the Weibull distribution case.

• Journal of the Korean Data and Information Science Society
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• 제18권3호
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• pp.689-696
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• 2007

This paper considers a Bayesian approach to determine an optimal PM policy with random maintenance quality. Thus, we assume that the quality of a PM action is a random variable following a probability distribution. When the failure time is Weibull distribution with uncertain parameters, a Bayesian approach is established to formally express and update the uncertain parameters for determining an optimal PM policy. Finally, the numerical examples are presented for illustrative purpose.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.328-333
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• 2007

Traditional maintenance planning is based on a constant maintenance interval for equipment life. In order to consider economic aspect for tm 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 much 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.

• 산업경영시스템학회지
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• 제30권1호
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• pp.1-7
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• 2007

This paper addresses a the maintenance system based on the concept of RAMS (Reliability, Availability, Maintenance, Safety) for the effective maintenance of the urban transit. A systematic approach for developing a cost-effective maintenance strategy based on the component reliability of the system in question is performed according to the following steps : definition of function, functional failures of the systems, construction of RBD (Reliability Block Diagram), and the calculation of reliability indices. The developed preventive maintenance system generates maintenance plan and repair request based on the analysed RAMS data of components and maintenance experience.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.618-619
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• 2015

The costs due to the maintenance and its method of national road have increased every year, and the maintenance costs have become higher due to the maintenance method without considering the characteristics of each region. This study is a preliminary study regarding the determination of maintenance method according to the characteristics of each region by applying variables (e.g. serviced time, traffic volume, average temperature, maximum temperature, minimum temperature, rainfall, and snowfall) to decide the maintenance and its method through the correlation analysis of road maintenance and repair period for each regional agency using the maintenance history data of national road management agency.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.279-280
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• 2023

Due to the deterioration of infrastructure, the importance of maintenance is continuously increasing. Therefore, an integrated maintenance method for various facilities is required. In this study, a maintenance priority determination method for integrated maintenance of roads and pipe network facilities was developed. It is possible to analyze attribute information by using GIS data of roads and pipe networks, and shape information can be used. This information is derived as quantitative figures for determining maintenance priorities. In the future, it is expected that facility maintenance can be further advanced in connection with maintenance method and quantity information for each facility.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.331-336
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• 2005

A lot of manufacturing knowledge and method have applied to increase manufacturing efficiency in industry field. DES(Discrete Event Simulation) is one of solution to deal with manufacturing problems in factory. Beginning of research, old maintenance system of KNR ( Korea National Railroad) and its technical problems are basically investigated. KNR has maintained railway vehicle with their own solution based on experience. Very advanced railway vehicles such as KTX (Korea Train Express) and TTX(Tilting Train Express) will be difficult to maintain with their old maintenance method. In order to apply knowledge of DES, maintenance field of railway must be considered. Imaginary maintenance machine are selected to variable of DES. Maintenance capability of each machine will be evaluated base on imaginary data from imaginary machine. The machine could be very expensive as well as difficult to replace. Target of research is minimization of number of machine in railway workshop. So basic knowledge of discrete event simulation is introduced. Then five essential stages of discrete event simulation are provided. Each maintenance case defined as event. Each event is discrete and simulated base on different case such as one maintenance line with one machine and one maintenance line with two machines in railway workshop. simple maintenance method, discrete event simulation, will be come out very powerful in complicate maintenance system and will be helpful to reduce maintenance cost as well as maintenance labor.