• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.77-85
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• 2013

In this paper, we present the cost measurement metrics for the operation management and service improvement besides the general maintenance. The cost measurement metrics of the operation management and service improvement are based on the metrics that are classified and summarized precedent studies and complemented by empirical measuring indicators, and we propose the maintenance cost estimation model based on this metrics. The maintenance costs can be calculated detailedly, because the proposed metrics can be used selectively, depending on the scope of the information system maintenance. The effectiveness of the proposed maintenance cost measurement metrics and cost estimation model is verified by comparison between existing studies and our research.

• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.353-360
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• 2009

Most information systems are component-based and developed by outsourcing, and developed software is maintained integrative. However, studies on cost measurement indicators and cost estimation model have not been performed sufficiently, which are foundational to enhance the productivity and efficiency of maintenance. This study suggests indicators to measure maintenance cost for component-based software and examines maintenance cost estimation model of component software by the measurement indicators suggested. In order to generate the indicators to measure the component-based maintenance cost, the previously proposed indicators are summarized comparatively. To estimate the measurement indicators of component-based software, it makes a comparison of the previously proposed indicators and arranges them. We classify the measurement indicators by how to apply according to maintenance types of component software and then we propose the cost measurement indicators. Moreover, we propose the cost estimation model according to the maintenance types of component software using the suggested measurement indicators suggested. With the suggested estimation model, a case study is performed and its validity is verified.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.347-350
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• 2008

유지보수 활동이 전체 프로젝트의 중요한 비중을 차지하면서 유지보수를 수행하기 위한 비용의 증가가 이루어져 왔다. 하지만 유지보수를 수행하고 관리하는데 사용되는 지표나 지침, 표준문서 등이 구체적으로 마련되지 않다. 유지보수 성능 수준을 향상시키고 유지보수를 평가, 관리하는데 있어 사용 할 수 있는 측정지표 등이 연구되어야 할 것이다. 본 연구에서는 자산관리를 위해 사용되는 유지보수스코어카드를 바탕으로 소프트웨어 유지보수 형태에 따라 유지보수 비용의 감소와 분석에 효과적으로 사용할 수 있는 측정지표와 정량적 계산이 가능한 비용 측정지표에 대하여 연구한다.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.321-326
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• 2008

The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.

• Journal of the Korean GEO-environmental Society
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• v.19 no.2
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• pp.37-44
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• 2018

Ballasted track has been widely used due to its flexibility. However, the plastic deformation of ballasted track causes the evolution of track geometrical errors, and hence it requires continuous maintenance; increase in number of trains, weight, and speed expedites maintenance frequency and cost as well. Ballast stiffness is well-known as an indicator of design and maintenance. In this regard, this paper aims to suggest the method to measure ballast track stiffness using light-weight deflectometer (LWD) and thus verify its applicability as a maintenance measure. Preliminary field tests determined simple field testing protocol to measure track stiffness. The apparent ballast stiffness by LWD shows good corelation with TQI (Track Quality Index) and maintenance length. That is, as average of apparent stiffness increase, TQI and tamping length decrease exponentially. Therefore, apparent stiffness can be used as an index for ballast condition assessment.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.83-83
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• 2023

댐의 침투수량은 준공이후 댐 안전성 확보를 나타내는 지표 중의 하나이며, 유지관리를 위해 침투수량 측정을 실시하여 관리를 하고 있다. 댐 타입별로 침투수량에 대한 허용치와 관리기준치는 다르지만, 기본적으로 댐에서 발생되는 침투수량은 측정범위를 넘지 않도록 관리를 하고 있다. 댐의 침투수량 측정은 댐 하류에 누수집수벽을 설치하고 댐에서 발생되는 침투수량을 집수한 후 삼각위어를 통하여 침투수량을 측정하고 있다. 이러한 침투수량 측정은 대부분의 댐에서 실시간으로 자동측정하고 있지만, 경우에 따라 미계측 구간이 발생되어 댐 유지관리 측면에서 미계측에 대한 원인분석이 필요한 실정이다. 일반적으로 침투수량의 미계측 원인은 계측기기, 삼각위어, 누수집수벽, 기초지반 등 다양한 원인이 있지만 명확한 원인을 찾기는 어려움이 많다. 특히, 댐 침투수량의 경우 지하수위, 댐 표면 우수, 침투수가 같이 측정되기 때문에 원인분석을 위해서는 다양한 검토가 필요하다. 본 연구의 표면차수벽형석괴댐은 누수집수벽을 통하여 침투수량을 측정하고 있으나, 일부 구간 미계측 부분이 발생하여 기초지반, 댐체 하류사면, 여수로와 댐체 접합부를 통한 누수를 원인으로 추정하였다. 이를 조사하기 위하여 전기비저항 탐사, 시추조사, 수압시험, 지하수위 측정 결과를 이용하여 누수발생 추정위치를 찾고, 침투수량이 미계측되는 원인을 분석하고자 하였다. 전기비저항 탐사는 여수로 접합부, 누수집수벽 상·하류 구간을 선정하여 측정한 결과 상·하류 저비저항대가 존재하는 구간을 추정할 수 있었다. 수압시험 결과 기초암반은 2.3 ~ 21.3 Lu(3.65×10^-5 ~ 3.65×10^-4 cm/sec)의 범위로 누수 가능성이 있는 높은 투수성을 갖는 부분을 확인할 수 있었다. 전기비저항 탐사, 수압시험, 지하수위 측정을 통해 누수집수벽 기초지반 누수발생 원인분석 결과 누수집수벽 기초암반을 통한 누수로 누수집수벽에 댐체를 통한 침투수량이 저류되지 못하는 현상이 발생하기 때문인 것으로 판단되었다. 침투수량계의 정상화를 위해서는 조사를 통해 확인된 누수집수벽 기초암반 누수구간의 그라우팅 보수보강이 필요함을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.71.1-71.1
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• 2010

본 연구는 1.3 MW급 태양광 발전소에서 기온 및 일사량에 따른 발전성능이 유지 보수 및 사후관리에 따라 성능이 향상될 수 있음을 실측자료를 통해 입증하는데 목적이 있다. 실측자료는 2008년 5월 전북 부안에 설치된 태양광 발전소에서 측정된 기온 및 일사량에 따른 발전량을 이용하였으며, 측정기간은 2009년 1월~2009년 12월까지 1년간 모니터링을 한 데이터를 기반으로 분석하였고, 발전소 성능 지표인 PR(Performance Ratio)을 계산하여 자료로 활용하였다. 또한, 실측자료는 PVSYST를 이용하여 실측자료와 동일한 조건에서 예측된 시뮬레이션 발전량 및 PR값과 비교 분석하였다. 실측자료와 해석결과의 비교에서 월단위로 측정된 실측 발전량과 예측 발전량은 유사한 경향을 나타냈으며, 실측 발전량은 예측 발전량 대비 약 5% 낮게 나타났다. 또한, 실측 PR값은 예측 PR값보다 약 4.97% 높게 나타났는데, 이는 해석을 위해 적용되는 일사량(기상청)과 실측 일사량이 다르고, Team Function 방식으로 구동되는 인버터와 시뮬레이션에서의 인버터 구동방식의 차이 때문인 것으로 판단된다. 한편, 일조량의 증가에 따른 1.3MW급 태양광 발전소의 발전량은 비례적으로 증가하는 경향을 나타냈으며, 7월의 경우 기후특성으로 인하여 국부적으로 감소하는 특성을 나타낸다.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.127-137
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• 2021

The method of utilizing the strain and vibration values of rails is primarily used to diagnose the condition of wheels and railroad facilities. The dynamic load is measured under the assumption that the strain of the rail and the load of the railroad vehicle are proportional. Wheel condition is measured under the assumption that the magnitude of the defect and the magnitude of the rail vibration are proportional. However, environmental factors affecting the strain and vibration of the rail such as vehicle speed, wheel load, climate, and track conditions are not reflected, many errors occur depending on the measurement conditions. In this study, the effect of track distortion, which is a major indicator of the track condition among the environmental factors that affect the strain and vibration of the rail, on the strain and vibration of the rail, was examined through dynamic simulation. As a measure to reduce the measurement deviation, the effect of securing additional measurement points was analyzed.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.527-534
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• 2013

The software is changed according to the changing businesses and the user requirement, it involves increasing complexity and cost. Considering the repetitive changes required for the software, replacement is more efficient than maintenance at some point. In this study, the replacement time was predicted using the service dissatisfaction index and replacement point assessment index by the software group for each task. First, fuzzy inference was used to develop the method and indicator for the user's service level dissatisfaction. Second, the replacement point assessment method was established considering the quality, costs, and new technology of the software. Third, a replacement time prediction technique that used the gap between the user service measurement and replacement point assessment values was proposed. The results of the case study with the business solutions of three organizations, which was conducted to verify the validity of the proposed prediction technique in this study, showed that the service dissatisfaction index decreased by approximately 16% and the replacement point assessment index increased by approximately 9%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.147-157
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• 2012

Recent studies on development of level of service (LoS) for separated sewer pipe have simply shown high-level of LoS from the perspective of users and financial/social/economical factors, which results in poor connectivity to real maintenance work. The objective of this study is to develope the evaluation indicators of level of service in the manner of function by analyzing the separated sewer pipes with FAST, function analysis systems technique, used in value engineering. The evaluation indicators suggested in this study include all the functions of separated sewer pipes and show an advantage of focused function maintenance. Moreover, developed indicators help to manage archival history and to perform asset management effectively.