• Journal of Applied Reliability
• /
• v.10 no.2
• /
• pp.93-105
• /
• 2010

The following thesis provides an explanation for the definition of the MIL-HDBK-2155 : Failure Reporting, Analysis and Corrective Action System (FRACAS), which systemizes the collection and analysis of failure data and the feedback process of the results. It also presents a plan based on MIL-HDBK-2155 for the collection and analysis of operating specifications on weapon systems. The collection and analysis of failure data and the feedback process utilizing FRACAS contributes to identifying improvement requirements during equipment operation as well as finding and eliminating the root cause of the failures. The objective of applying FRACAS to weapon systems is to receive source data feedback for reliability enhancements and performance improvements during operation. This is done by recognizing weaknesses in the design or operation by identifying the type of failures that might occur, and by performing Failure Modes, Effects and Criticality Analysis(FMECA) and Failure Tree Analysis(FTA).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.3B
• /
• pp.504-509
• /
• 2000

This paper presents a noble operation and maintenance system for the optical subscriber loops and its feasibility through several experiments. In this system, a broadband CW (Continuous Wave) light source I used as monitoring of testing signals. and a FGF(Fiber Grating Filter) of which reflective wavelength is independent, is inserted somewhere in each subscriber loop for the reflection of monitoring of testing signals. The propose of the system is quick decision. whether the loop is just fault or not. rather than detailed information of loop state. At present, most of operation and maintenance system for the optical subscriber loops adopts OTDR(optical time domain reflectometer) for testing function. the OTDR is useful for detailed test, but not adequate for simple test because of long testing time . And it is difficult to test PON network by using general OTDR that has a single-wavelength light source. Compared to using OTDR, the proposed system can afford to shorten testing time and to test PON network. Moreover, we can cut down the system cost by simplifying circuits of the optical light sources. Our results show that the proposed system operates well according to the purpose mentioned above.

• Journal of Platform Technology
• /
• v.8 no.4
• /
• pp.3-10
• /
• 2020

An elevator maintenance company maintains many types of elevators from many manufactures. So, they want to use manufacture- or type-independent elevator remote monitoring system. To do this, data logger, that receives elevator operating state data from sensor module installed in elevator and transfers the data to database, is required. In this paper, we design and implement data logger of elevator remote monitoring system for providing elevator operation state information to elevator maintenance company. Data logger receives elevator operation state data from sensor module installed in elevator, decodes data, and converts to API data for transferring elevator operation state data to server. In this paper, we describe the implementation of data logger using python, and show that our implementation of data logger is successfully operating in a real elevator operating environment via log message displayed at screen.

• Journal of Wind Energy
• /
• v.14 no.3
• /
• pp.34-42
• /
• 2023

The reduction of operation and maintenance (O&M) costs is a critical factor in determining the competitiveness of wind energy. Predictive maintenance based on the estimation of remaining useful life (RUL) is a key technology to reduce logistic costs and increase the availability of wind turbines. Although a mechanical component usually has sudden changes during operation, most RUL estimation methods use the trend of a state index over the whole operation period. Therefore, overestimation of RUL causes confusion in O&M plans and reduces the effect of predictive maintenance. In this paper, two RUL estimation methods (load based and data driven) are proposed for the bearings of a wind turbine with the results of trend classification, which differentiates constant and increasing states of the state index. The proposed estimation method is applied to a bearing degradation test, which shows a conservative estimation of RUL.

• Journal of Energy Engineering
• /
• v.20 no.2
• /
• pp.154-162
• /
• 2011

PMT(Preventive Maintenance Template) is a standardized maintenance program that describes maintenance items & period as operation condition to increase component reliability at the component level. The existing maintenance programs are focused on time based maintenance to inspect and repair component depend on fixed period. But recently, we have developed advanced maintenance program(named PMT) to increase reliability and optimize maintenance program of the plant significant component. This paper presents how to develop the PMT for nuclear power plant's static exciter.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
• /
• v.17 no.1
• /
• pp.20-29
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.295-296
• /
• 2013

• Magazine of the Korea Institute for Structural Maintenance and Inspection
• /
• v.20 no.2
• /
• pp.46-51
• /
• 2016

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.6
• /
• pp.1901-1910
• /
• 2014

Current domestic and overseas BIM practice and research efforts show very few examples that design and construction BIM data could be successfully used for efficient operation and maintenance (O&M) of infrastructure in particular. This study takes public wastewater treatment plant requiring an enhancement of operation and maintenance capability into account to develop a prototype BIM-based maintenance management system. The system is designed and implemented following a typical system development procedure and validated by the system outputs per four scenarios being considered to be main maintenance activities: The research results are expected to contribute to the upgrade of current wastewater treatment plant maintenance level, which is more demanded as water-related regulation and policy direction changes to region-based large scale O&M and asset management adoption, and overseas market participation.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.05a
• /
• pp.167-172
• /
• 2002

During the operation of military aircraft, maintenance is divided into organizational, intermediate and depot maintenance. In the depot maintenance, after removal of major parts and removable doors, damage assessment is performed. Locating damage, charactering the damage and determining its extent, zoning the damage on the part being repaired and re-evaluation of the damaged area after damage removal. Repair joints are classified by bonded joints and bolted joints, depending on joining material. In this paper, repair method in aging aircraft is investigated and the possibility of application of copmposite patch is surveyed.