• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.565-569
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• 2011

This paper presents minimum area repair method that is one of the preventive maintenance techniques in asphalt concrete pavements. In this method, a 70cm-width as an effective repair zone was suggested considering the conventional longitudinal damages (rutting and fatigue cracking) in early stages. In addition, the repair zone can be readjusted according to the pavement damage levels. A field test bed was constructed to verify the adaptness for the repair method. Test results revealed that the minimum area repair method can be adopted as a preventive maintenance technique in flexible pavements to recover an appropriate serviceability level. The preventive maintenance method may be one of the major maintenance methods of flexible pavements with an appropriate application. It is also noted that the method may be a long term maintenance cost effective and pavement life ensuring one.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.45-51
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• 2009

The paper presents the economic analysis of optimized-rehabilitation area method considered as one of the preventive maintenance methods in asphalt concrete pavement. The optimized-rehabilitation area was selected based on the analysis of traffic lane characteristics. The main concept of the selected method was to minimize the maintenance cost. The effective width of traffic lane in this method was 70 cm of each wheel path. According to the traffic survey conducted in this research, more than 95% of vehicles passed within the width of each wheel path. The new preventive optimized-rehabilitation area method showed less maintenance cost than the conventional overlay. In addition, traffic congestions and the user cost can be reduced. The research results revealed that the total maintenance cost was reduced by 35% by using the new method compare to the conventional one.

• 한국도로학회지:도로
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• v.8 no.1 s.27
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• pp.13-21
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• 2006

• 전기의세계
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• v.37 no.10
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• pp.46-53
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• 1988

앞으로 보수관리를 효율적으로 대처하기 위하여, 또한 대용량화및 새로운 설비 증가에 따른 각종 정보처리, 기술의 진일보를 위하여 자동화 및 기계화 기술을 과감히 도입 적용하여야 설비의 수명을 극대화하고, 안정된 전력공급을 효율적으로 이룩할수 있을 것으로 생각한다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.6
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• pp.557-564
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• 2009

Welding residual stress is occurred after welding process. Tensile residual stress is one factor of PWSCC. Repair welding usually happened during the manufacturing welding process. Repair welds cause strong tensile residual stress. In PWR, Repair weldments made by Alloy 82/182 is susceptible to PWSCC caused by tensile stress, material and environment. Therefore, mitigation of welding residual stress in weldments is important for reliable operating. PWOL is one of the methods for mitigation and verified for over twenty years. In this paper, residual stress distribution of repaired weldments and the effect of PWOL on mitigation is examined for surge nozzle.

• 한국도로학회지:도로
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• v.16 no.2
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• pp.37-45
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• 2014

• 한국도로학회지:도로
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• v.8 no.3 s.29
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• pp.17-24
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• 2006

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1373-1374
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• 2012

공공시설 자산관리는 기존의 대응적 유지보수 개념의 시설물유지관리체계에서 예방적 유지보수 개념으로 전환한 시설물 유지보수의 새로운 개념이다. 기존에 운영되고 있는 공공시설관리 시스템들을 효율적으로 관리하기 위해서는 자산관리 모형이 표준화되어 범정부EA 지원시스템에 목표아키텍처로 등록되고 더 나아가서는 범정부 표준시스템으로 만들어 필요한 기관에 보급할 필요가 있다. 이 연구에서는 공공시설 자산관리 정보시스템을 구축하는데 필수적인 참조모델을 시스템의 상호운영성과 정보의 호환성을 확보하기 용이하도록 범정부EA 관점에서 제시하였다. 제시한 자산관리 참조모델이 GEAP에 등록 관리 된다면 이것을 바탕으로 타 기관에서 향후 정보시스템을 구축할 때 사전에 파악하고 활용하도록 제안 할 수 있을 것이다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.191-201
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• 2016

A stochastic process has been used to develop a condition-based model for preventive maintenance of armor units of rubble-mound breakwaters that can make a decision the optimal interval at which some repair actions should be performed under the perfect maintenance. The proposed cost model in this paper based on renewal reward process can take account of the interest rate, also consider the unplanned maintenance cost which has been treated like a constant in the previous studies to be a time-dependent random variable. A function for the unplanned maintenance cost has been mathematically proposed so that the cumulative damage, serviceability limit and importance of structure can be taken into account, by which a age-based maintenance can be extended to a condition-based maintenance straightforwardly. The coefficients involved in the function can also be properly estimated using a method expressed in this paper. Two stochastic processes, Wiener process and gamma process have been applied to armor stones of rubble-mound breakwaters. By evaluating the expected total cost rate as a function of time for various serviceability limits, interest rates and importances of structure, the optimal period of preventive maintenance can easily determined through the minimization of the expected total cost rate. For a fixed serviceability limit, it shows that the optimal period has been delayed while the interest rate increases, so that the expected total cost rate has become lower. In addition, the gamma process tends to estimate the optimal period more conservatively than the Wiener process. Finally, it is found that the more crucial the level of importance of structure becomes, the more often preventive maintenances should be carried out.

• 한국도로학회지:도로
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• v.20 no.2
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• pp.55-62
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• 2018