• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.345-356
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• 2012

Road pavement requires repetitive maintenance works to maintain satisfactory service level to the public. However, the repetitive maintenance works upon deteriorated pavement structure make negative effects to deterioration speed. It often leads to inefficient use of limited budget. For that reason, the pavements require reconstruction work to recover their original performance. Recently, construction demands in the Korean national highway have already been reached to maximum level, and the aged pavements start to demand much more reconstruction works. However, in the real world, road agencies have often been confused when they determine maintenance design for such aged road sections due to budget constraint. It is because there is no reliable long-term maintenance strategy that supports their decision making. To support their decision making, this paper aimed to suggest the best maintenance strategy considering changing process of pavement performance by repetitive maintenance works. As an analysis method, probability distribution and hazard function to estimate the life expectancy were adopted, and then the results were used for long-term life cycle cost analysis with deterministic or Monte-Carlo method under various scenarios. As an empirical study, the Korean national highway data that has long-maintenance history data since 1986 has been applied. Last, this paper considered quality assurance of maintenance work to improve maintenance quality. These could be important information as a part of long-term maintenance strategy of pavement.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.91-98
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• 2009

One role of waterproofing work is to block external moisture and water. Defects in waterproofing work in building construction brings on huge repair costs for related construction work as well as for the waterproofing layer itself. However, we don't have a quantitative probabilistic management method for waterproofing work to successfully anticipate and prevent defects. From an analysis of the literature and prior research, defects in the waterproofing work in the underground parts of buildings occur frequently. We selected Fluid-Applied Membrane waterproofing work as representing waterproofing work in the underground parts of a building, and researched the general types and causes of defects. In this study, we developed the Relative-FMEA (Failure Mode and Effect Analysis) approach that merges the Matrix method and FMEA. From a survey of experts, we deduced the most important management factors for Fluid-Applied Membrane waterproofing work for the underground parts of buildings.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.109-123
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• 2011

The maintenance prices in information security industry between Korean companies and foreign companies have been a big difference. Korea Information Security SW maintenance standards were not adequate for the rate, and there was disagreement between domestic companies and governments. This research, therefore, surveyed a standard of information SW and the status of maintenance payment rates. The study suggests an estimation method and verifies the method and an appropriate maintenance cost rate. According to the results of the study, the current maintenance cost should be increased or decreased independent with a kind of information security systems. Based on the study, Korea government is able to change the maintenance policy in information security. And the domestic companies get a theoretical ground for improving the rates of maintenance costs in information security systems and are able to allot the resources effectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2A
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• pp.223-231
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• 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 Korea Institute of Building Construction
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• v.15 no.2
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• pp.209-215
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• 2015

This study was conducted to analyze the actual utilization rate of the deposit for defect repair of apartment complexes and its influential factors. We analyzed the data on enforced defect deposit cases by using one-sample t-test, Pearson's correlation analysis, and simple linear regression analysis. The difference between the deposit amount specified and the enforcement amount actually disbursed was found to about 0.51%. The change rates for short-term costs amounted approximately to $839KRW/m^2$ and 130,000 KRW/household per year, and those for long-term costs were $647KRW/m^2$ and 123,207 KRW/household per year. The results warrant the need for further research on establishing a deposit amount based on actual statistical data.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.705-706
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• 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 Korea Society of Computer and Information
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• v.1 no.1
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• pp.105-128
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• 1996

The maintenance cost accounts for over a half of all software costs. Maintenance tools can be used to reduce It. All other maintenance techniques. reverse engineering Is a process of analyzing source code to extract design information and to create representation of it In another form or at the higher level of abstraction. In this thesis. we propose a method to extract the call relationships among programs. the logic structure In program and the data flow of programs iron COBOL source Programs using reverse engineering. We also present a method to generate the structure chart of programs and modules. The structure chart generated from source code provides very important information to understand programs In details. The structure chart modified will be more helpful the maintainer to understand programs when he analyzes them later or others analyze them.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.153-159
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• 2018

Many researches have been carried out on carbonation, a representative deterioration in underground structure. The carbonation of RC (Reinforced Concrete) structure can cause steel corrosion through pH drop in concrete pore water. However extension of service life in RC structures can be obtained through simple surface protection. Unlike the conventional deterministic maintenance technique, probabilistic technique can consider a variation of service life but it deals with only normal distributions. In the work, life time-probability distributions considering not only normal but also log distributions are induced, and repair cost estimation technique is proposed based on the induced model. The proposed technique can evaluate the repair cost through probabilistic manner regardless of normal or log distribution from initial service life and extended service life with repair. When the extended service life through repair has log distribution, repair cost is effectively reduced. The more reasonable maintenance strategy can be set up though actual determination of life-probability distribution based on long term tests and field investigations.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.87.1-87.1
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• 2015

우리나라는 세계적으로 보기 드문 조류발전의 적지이며, 특히 진도 울돌목, 장죽수도, 맹골수도, 완도 횡간수도 등 서남해안에 조류에너지 여건이 좋은 상태이다. 조류발전시스템은 물속에 잠겨서 동작하는 형태이므로, 대형 고정 설비가 요구되어 높은 부대비용 발생과 이상유무 발생시 유지보수가 어려운 문제가 있다. 이를 위해 설비 및 설치비용을 줄이는 부유식 형태와 유지보수가 용이한 구조 설계를 적용한 실용적인 조류발전시스템 개발하며, 주요 적용처로 관심이 높아져 가는 에너지자립섬 적용을 목표로 섬내 전기 수요에 부합되는 15 kW급 조류발전을 공급하고자 하며, 이외 다양한 해양에너지를 활용한 에너지 자립화 방향을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2385-2387
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• 2002

종래 도로상의 차량검지기들은 기후변화 및 도로환경의 변화, 물리적인 변화에 영향을 받아 감지의 정확도가 떨어져 신뢰도 높은 교통정보를 생성하기가 어렵고, 제품의 가격이 고가이며, 설치 및 유지, 보수에 많은 비용과 인력이 요구된다. 본 연구에서는 종래의 차량 검지기가 지니는 문제점들을 해결하여 어떠한 환경하에서도 신뢰성 있는 차량 주행정보를 제공하며 동시에 유지, 보수 비용이 저렴한 검지기로서 AMR(Anisotropic Magneto-Resistive) 센서를 이용하여 도로상의 차량 이동에 따른 지구자기장(Earth Magnetic Field) 변화를 감지하고 차량의 이동상태를 파악하는 교통량 계측장치를 제시한다.