• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.365-373
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• 2002

For gas turbine engines, the safe life methodology has historically been used fur fatigue life management of failure critical engine components. The safe retirement limit is necessarily determined by a conservative life evaluation procedure, thereby many components which have a long residual life are discarded. The objective of this study is to introduce the damage tolerant design concept into the life management for aircraft engine component instead of conservative fatigue life methodology which has been used for both design and maintenance. Crack growth data were collected on a nickel base superalloy which have been subjected to combined static and cyclic loading at elevated temperatures. Stress analysis fur turbine disk was carried out. The program for computing creep-fatigue crack growth was developed. The residual lifes of turbine disk component under various temperatures and conditions using creep-fatigue crack growth data were estimated. As the result of analysis, it was confirmed that retirement fur cause concept was applicable to the evaluation of residual life of retired turbine disk which had been designed based on the conventional fatigue life methodology.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.268-270
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• 2015

Overseas countries' government and facility management industries make efforts to ensure precise and fluent data from building information modeling (BIM). In facility management, a large amount of data and information are necessary to continue the process activities. Facility condition assessment, which is performed to make budget plan for the maintenance and operation requires the related facilities' documentation and information. However, it depends on the owner and the user of the facility to provide accurate and complete information to consultant. The problems as follows: (1) owner and user should provide documents and information, and (2) the consultant cannot verify the provided information. To solve these problems, we suggest a methodology to produce the information for FCA through BIM. First, all of the essential documentation and assessment elements are listed. Next, the documents and elements are separated out, whether they are able to be extracted from BIM or not. Then, the list indicates only the data that is linked with BIM. The suggestion is expected to provide the required information through the connection to BIM with accuracy and completeness and to present another BIM application use for facility management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.921-932
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• 2002

In this research, we seek to identify an effective operation management strategy of telecommunication systems. In order to develop operation management strategies, we implement a quantitative techno-economic analysis. We evaluate related issues and factors, and apply the developed method to PSTN switching systems. In the proposed techno-economic modeling, we apply a well-known factor analysis technique-analytic hierarchy process-to evaluate PSTN operation management strategies. Then, we implement a decision analysis methodology to evaluate the cost of proposed strategies. We evaluate the proposed methodology by using available real data of the PSTN system. The primary impact of this research will be realized in helping PSTN operator select the best operation management strategy of PSTN system.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.157-164
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• 2012

PURPOSES: Regional offices of the Ministry of Land, Transport and Maritime Affairs use a computerized system called KAMIS so as to manage road equipment systematically. Road agencies can record number of operating days by equipment, actual working hours, accumulated operating hours (or distance) by equipment, and operating cost. However, KAMIS does not provide critical information, although it is strongly related to efficient road management equipment operation. In other words, road agencies do not know whether they have sufficient equipment to handle their actual work. METHODS: Therefore, this study suggests a methodology to evaluate for operational efficiency of road management equipment using analytical hierarchy process(AHP). First of all, estimated weights related criteria can be produced by AHP, and then use operational history by pieces of equipment. RESULTS: Results show that importance of management work can differ from weather conditions through five areas. CONCLUSIONS: Commonly, this results can imply to help save money for the purchase and maintenance of road management equipment, and they would improve the functional performance of KAMIS.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.45-57
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• 2009

BTL (Build-Transfer-Lease) Project for Education Facilities are contracted as a package which consists of several education facilities. The general maintenance period of BTL project for education facilities is 20 years. Thus, total cost variation largely depends on the accuracy of the maintenance cost forecasting in the early stage in the life cycle of the BTL Project. This research develops a cost forecasting system using complete linkage algorithm and branch & bound algorithm to help in finding optimal bundling combination. This system helps owner's decision-making to estimate the total project cost with various constraints changing. The result of this research suggests more reasonable and effective forecasting model for the maintenance facilities package in the BTL project.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.4
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• pp.19-28
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• 2020

Purpose - This study aims to lay the foundation for a desirable direction to solve future environmental problems through framework research on environmental cooperation according to distribution of urbanization between South and North Korea. The article also attempts to explore solution to two Koreas' environmental problems from the cooperative perspective between South and North Korea and draw future policy tasks. Research design, data, and methodology - For methodology, North Korea's legal system to cope with disasters is taken into consideration in terms of literature review. This study also analyzes a series of processes related to North Korea's disaster management through case study, and draws policy measures for North and South Korea's cooperation scope and methods. Result - The results support that North Korea is very vulnerable to environmental disasters due to food shortages, economic sanctions, and enormous natural disaster damages including flood damages occurring each year, because of the lack of disaster prevention infrastructure such as river maintenance. Conclusion - At the current time when North and South Koran exchange and cooperation increase, a disaster management cooperative system is needed for the areas where South and North Korea manage through division. It also suggests that there is a need to establish regulations and procedures for support items in advance for a quick response to disasters in North Korean region.

• Journal of the Korean Society of Safety
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• v.26 no.6
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• pp.111-117
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• 2011

Risk-based railway safety management has been mandatory in Korea as by relevant laws and regulations enacted since the Railway Safety Act 2004. In particular, the Railway Vehicle Safety Guidance came into effect on Jan 1, 2008 specifies the details of methodology for hazard analysis, risk assessment and safety verification and validation. Fundamentals for success of the risk-based safety management are systematic hazard identification and risk assessment by use of reasonable risk assessment criteria, but the principle of risk-based safety management has not been applied in an effective way to introduction and maintenance of railway vehicle systems because definite risk assessment criteria have not been set down for each railway system or railway network. The purpose of this study is to suggest a risk matrix development principle for risk assessment of domestic urban metro vehicles by analyses of relevant rules and railway operating environment of Korea.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.269-277
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• 2009

we can easily find numerous cases, where the outcomes are not up to their expectations, despite the enormous efforts and investments poured on developing ERP systems. Consequently, we are in need of a new methodology for efficient implementation and Maintenance of an ERP system. Therefore, we have investigated and analyzed various problems that may occur in adopting ERP systems, such as high implementation costs, shortage of professional manpower, and lack of active participation from insiders. In this thesis, we developed a new ERP system, focusing on accounting management modules and benchmarked our proposed model to one of the real companies.

• International Journal of Railway
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• v.3 no.1
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• pp.34-37
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• 2010

In recent, the railway system consists of subsystems as rolling stock and infrastructures as signaling, telecommunication, power supply, overhead contact and platform screen door, etc. Furthermore, each subsystem has complicated interface so as not to understand these relationship. Consequently, to operate the railway system continuously with required safety and availability, the failure data should be corrected and analyzed systematically during operation. To achieve this object effectively, this paper presents the method which is evaluating the operational risk quantitatively using failure data, and selecting the critical equipment. Following this analysis, the improvement plan is established and applied to reduce the operational risk on system or equipment. From this study, the critical equipments of system could be determined and prioritized by risk analysis. Also, the effective maintenance to prevent critical failure could be implanted by this suggested methodology.

• Safety and Health at Work
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• v.9 no.1
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• pp.42-52
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• 2018

Background: Maintenance operations on-board ships are highly demanding. Maintenance operations are intensive activities requiring high man-machine interactions in challenging and evolving conditions. The evolving conditions are weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress. For example, extreme weather condition affects seafarers' performance, increasing the chances of error, and, consequently, can cause injuries or fatalities to personnel. An effective human error probability model is required to better manage maintenance on-board ships. The developed model would assist in developing and maintaining effective risk management protocols. Thus, the objective of this study is to develop a human error probability model considering various internal and external factors affecting seafarers' performance. Methods: The human error probability model is developed using probability theory applied to Bayesian network. The model is tested using the data received through the developed questionnaire survey of >200 experienced seafarers with >5 years of experience. The model developed in this study is used to find out the reliability of human performance on particular maintenance activities. Results: The developed methodology is tested on the maintenance of marine engine's cooling water pump for engine department and anchor windlass for deck department. In the considered case studies, human error probabilities are estimated in various scenarios and the results are compared between the scenarios and the different seafarer categories. The results of the case studies for both departments are also compared. Conclusion: The developed model is effective in assessing human error probabilities. These probabilities would get dynamically updated as and when new information is available on changes in either internal (i.e., training, experience, and fatigue) or external (i.e., environmental and operational conditions such as weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress) factors.