• Smart Structures and Systems
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• 제20권6호
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• pp.697-708
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• 2017

Maintenance plays a critical role in the bridge industry, but actual practices show many limitations because of traditional, 2D-based information systems. It is necessary to develop a new generation of maintenance information management systems for more reliable decision making in bridge maintenance. Enhancing current work processes requires a BIM-based 3D digital model that can use information from the whole lifecycle of a project (design, construction, operation, and maintenance) through continuous exchanges and updates from each stakeholder. This study describes the development of a data scheme for maintenance of cable-stayed bridges. We implemented the proposed system for a cable-stayed bridge and discussed its effectiveness.

• 정보처리학회논문지D
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• 제13D권6호
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• pp.797-806
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• 2006

데이터 웨어하우스에서는 질의를 빠르게 처리하기 위해 실체화 뷰(materialized view)가 흔히 사용된다. 실체화 뷰는 그의 정의에 포함된 데이터 소스들이 변경되면 이를 반영하기 위해 갱신되어야 한다. 실체화 년의 갱신은 많은 부하를 야기하므로, 실체화 뷰를 효율적으로 갱신하는 것은 매우 중요한 문제이다. 실체화 뷰의 효율적인 갱신 방법에 대해서는 이미 많은 연구가 있어왔지만, SPJ(Select-Project-Join) 형태로 정의된 실체화 뷰를 효율적으로 갱신하는 방법은 충분히 연구되지 않았다. 본 논문에서는 데이터 소스들에 대한 접근 비용을 최소화함으로써 SPJ 실체화 뷰를 효율적으로 점진적으로 갱신하는 방법을 제안한다. 제안하는 방법은 동적 계획법 알고리즘을 사용하여 최적의 갱신 방법을 찾는다. 마지막으로, 다양한 성능 평가 실험을 통해 제안하는 방법이 우수한 성능을 가지고 있음을 보인다.

• 한국철도학회논문집
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• 제3권3호
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• pp.139-146
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• 2000

Recently, many kinds of research have been actively developing for a standardization and information to the field of design, construction, supervision, maintenance and management on facilities. The establishment of standard classification system on tunnel facilities and inspection data is most important among the things to have a efficiently maintenance and management. This paper suggests standard classification system on tunnel facilities and inspection data, and, on the basis of that, code work with standard classification system and input work was practised. The purpose of this paper is to suggest a kind of statistics data and investigate a characteristics of inspection using statistic data on railway tunnel.

• Korean Journal of Geomatics
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• 제4권1호
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• pp.17-22
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• 2004

It is very important to manage efficient data for safety and maintenance of those constructs. Estimation for structural safety can be evaluated by using data that surveys various structural durability and safety elements. so, it should be based on synthetic and efficient data that includes a variety of related safety elements obtained from a structure. It will subsequently be managed properly and economically. Accordingly, we will approach efficient maintenance management using a Geographic Information System (GIS) with data from structural-safety diagnosis and a Global Positioning System (GPS). In this study, we noted that by using the data that measures the factors (crack, incline, settlement etc.) of various structures as evaluate safety degree. And the horizontal coordinate variation/time of structure was monitored using the GPS easily.

• 한국산학기술학회논문지
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• 제19권10호
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• pp.82-88
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• 2018

방어용 무기체계 중 하나인 기만체계는 소모성 방식으로, One-shot system에 해당된다. 주기적 점검을 통해 신뢰도를 유지하며, 발사를 해보아야 정상 작동여부를 확인할 수 있어 고신뢰도가 요구된다. 본 논문에서 분석하고자 하는 기만체계는 개발 시 목표 신뢰도 설정 및 신뢰도 예측 없이 정비주기가 설정되었다. 그러나 현재 군에서 운용 중인 수량이 점점 증가하여 정비주기 최적화 필요성이 대두되었다. 이에 따라 수십 년간 지속적으로 운용된 기만체계의 정비 데이터를 통하여 신뢰도를 분석하고 최적 정비주기를 제시하였다. 2장에서 신뢰도 분석에 사용된 데이터 수집 및 분류방법을 제시하였으며, 분석 방법론에 대해 간략하게 소개하였다. 이를 토대로 3장에서 데이터에 대한 분포 분석 및 적합도 검증을 통해 본 기만체계 정비 데이터는 와이블 분포를 적용 하는 것이 가장 적합함을 확인하였으며, 와이블 분포의 형상 및 척도모수를 추정하였다. 4장에서는 도출된 분포를 통해 백분위수, 생존확률, MTBF 분석결과를 제시하였다. 또한 시간별 신뢰도 분석결과를 통해 적정 정비주기를 도출하였다. 5장 결론에서는 향후 본 연구결과에 대한 향후 활용방안을 제시하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2209-2214
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• 2010

The purpose of Reliability Centered Maintenance(Hereafter, RCM) is to enhance the effectiveness and efficiency of preventive maintenance by applying the improvement plan after analysis of existing preventive maintenance. To accomplish this, it is required to collect the failure data for equipments during operation, and to carry out the quantitative criticality analysis for each equipment. This paper shows that the case study of RCM criticality analysis based on the accumulative failure data and following improvement activity for KORAIL AIRPORT RAILROAD's E&M system.

• 산업경영시스템학회지
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• 제43권4호
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• pp.123-132
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• 2020

Currently, there are two types of trainer in Korea : basic and advanced. Both models have been in operation for more than 10 years, and compared to the early stage of operation, reliability has gradually improved and failure rates have also entered a trend of stabilization. Therefore, it is necessary to extend the maintenance period considering economic feasibility. This study investigates the three maintenance period calculation methods: NAVAIR 00-25-403 [17], DOD, U.S. [4], CERL and US Army [3], with intention to extend the maintenance period of the trainer from current 200 hours to 400 hours. In addition, the maintenance period was calculated by the three methods with actual operational data. Common standards and procedures were established to apply operational data to the existing maintenance period calculation methods, the required reliability indicators were derived, and the maintenance periods was calculated based on the results, additionally, a review on the field applicability of the three maintenance cycles was conducted. An on-site interviews were conducted with the calculation results, and 11 out of the 15 items were expected to be extended by 400 hours. It was suggested that the remaining 4 items could be extended to 400 hours by supplementing the inspection method through additional analysis such as functional analysis, inspection content verification, and site connection.

• Smart Structures and Systems
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• 제26권4호
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• pp.533-544
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• 2020

Effective bridge maintenance reduces bridge operation costs and extends its service life. The possibility of storing bridge life-cycle data in a 3D parametric model of the bridge through Bridge Information Modeling (BrIM) provides new opportunities to enhance current practices of bridge maintenance management. This study develops a Decision Support System (DSS), namely BrDSS, which employs BrIM and an efficient optimization model for bridge maintenance planning. The BrIM model in BrDSS extracts basic data of elements required for the optimization process and visualizes the inspection data and the optimization results to the user to help in decision makings. In the optimization module of the DSS, the specifically formulated Genetic Algorithm (GA) eliminates the chances of producing infeasible solutions for faster convergence. The practicality of the presented DSS was explored by utilizing the DSS in the maintenance planning of a bridge under operation in the southwest of Iran.

• 한국농촌건축학회논문집
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• 제23권2호
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• pp.9-16
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• 2021

The purpose of this study is to maintain the existing characteristics of the city by utilizing the physical decline status and floating population in small and medium cities residential areas. In addition, it intends to present the direction of flexible urban regeneration and maintenance by reflecting regional characteristics and current status. A total of three data were used in this study. Building data, floating population data, and census output area data were used. Building data and floating population data were classified into five classes. The graded data were joined to the census output area data and analyzed by overlapping the two data. As a result of analysis of 17 residential areas in 5 small and medium cities in Jeollanam-do, 4 types, 2 management models, and 4 indicators could be presented by grade and regional characteristics. This study is meaningful in that it is possible to plan regionally customized urban regeneration/maintenance management plans and projects through the typology of the current status and characteristics of the region, which is an important step in the bottom-up form.

• Journal of Information Technology Applications and Management
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• 제19권2호
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• pp.181-196
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• 2012

The cost of software maintenance occupies about two thirds in the software lifecycle. However, it is not easy to estimate the cost of software maintenance because of various viewpoints about software maintenance, unclear estimation methods, and complex procedures. Until now, the cost estimation model has used compensation factors for software characteristic and environment on the basis of program size. Especially, most of existing models use maintenance rate of total software cost as a main variable. This paper suggests the software maintenance cost estimation model that uses the result of calculating real maintenance efforts. In this paper, we classify functional maintenance and non-functional maintenance as software maintenance activity type. For functional maintenance, present function point of target software is needed to evaluate. The suggested maintenance cost evaluation model is applied to a software case in public sector. This paper discusses some differences between our model and other modes.