• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.4
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• pp.505-516
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• 2018

In order to establish an efficient bridge maintenance strategy, the future performance of a bridge must be estimated by considering the current performance, which allows more rational way of decision-making in the prediction model with higher accuracy. However, personnel-based existing maintenance may result in enormous maintenance costs since it is difficult for a bridge administrator to estimate the bridge performance exactly at a targeting management level, thereby disrupting a rational decision making for bridge maintenance. Therefore, in this work, we developed a representative performance prediction model for each bridge element considering uncertainty using domestic bridge inspection data, and proposed a bayesian updating method that can apply the developed model to actual maintenance bridge with higher accuracy. Also, the feasibility analysis based on calculation of maintenance cost for monitoring maintenance scenario case is performed to propose advantages of the Bayesian-updating-driven preventive maintenance in terms of the cost efficiency in contrast to the conventional periodic maintenance.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.8-16
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• 2020

In Article 311 of the Regulation on Occupational Safety and Health Standards requires the use of Korean Industrial Standards Act in accordance with the Industrial Standardization Act. However, the classification, inspection, maintenance, design, selection, and installation of explosion hazard locations for explosion and explosion prevention and internalization of 'safety' in the performance maintenance phase of electrical machinery and equipment There is no technical and institutional management plan for remodeling and alteration. Analysis of actual conditions and problems related to the installation, use, and maintenance of explosion-proof equipment, comparative analysis of domestic and international technical standards and systems, technical, institutional and administrative systems and systems related to installation, use, and maintenance of explosion-proof equipment, technical personnel and qualifications, etc. It is to propose legislation, system improvement, and technical standard establishment related to the maintenance of explosion-proof facility performance through improvement of the necessity and feasibility study for establishment of the legal status of the management site and management plan. As technical measures, KS standard revision (draft), KOSHA guide (draft) and explosion-proof facility performance maintenance manual were presented. In addition, the institutional management plan proposed the revised rule on occupational safety and health standards, the revised rule on the restriction of employment of hazardous work, and the manpower training program related to the maintenance of explosion-proof facilities and the qualification plan. Enhance safety at the installation, use, and maintenance stage of explosion-proof structured electrical machinery. It is expected to be used to classify explosion hazards, select related equipment, and to update and standardize standards related to installation, use and maintenance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.465-469
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• 2010

Air heater used in power plant helps increase the thermal efficiency of the boiler by recovering the heat from the boiler flue gas and thus preventing the loss of useful heat. This study investigates the effect of preventive maintenance on the performance of the air heater in a power plant. Performance indexes for the air heater are calculated to observe the changes in the performance and operation status of the air heater before and after preventive maintenance. The major performance indexes considered are temperature efficiency of the flue gas side, air leakage rate, heat recovery rate, heat transmission rate, and heat capacity ratio. The performance of the air heater is evaluated before and after preventive maintenance; our results show that all the abovementioned performance indexes are improved after the maintenance.

• Journal of Korean Society of Steel Construction
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• v.18 no.6
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• pp.677-686
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• 2006

In this paper, a more practical and realistic method is proposed to establish the lifetime optimum maintenance strategies of the deteriorating bridges considering the life-cycle performance as well as life-cycle cost. The genetic algorithm is applied to generate the set of maintenance scenarios that is the multi-objective combinatorial optimization problem related to lifetime performance and cost as separate objective functions, and the technique to select optimum tradeoff maintenance scenario is presented. Optimum maintenance scenarios could be generated not only at the individual member level but also at the system level of the bridge. Through the analytical results of applying the proposed methodology to the existing bridge, it is expected that the methodology will be effectively used to determine the optimum maintenance strategy for introducing a real preventive maintenance system and overcoming the limits of existing maintenance methods.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.51-56
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• 2005

It does not find for solution by limitation of technological mechanism of existent of leakage maintenance material. So, it is paid for huge expense because continuous repeat maintenance work is consisting. Furthermore, it is indicated by big problem in construction work that is constructed by field experience that thing by definite and systematic theory is not with proper performance test and analysis up to now. Therefore, wish to measure physical performance change by various environment condition maintenance of structure and performance construction work aspect in that apply to water leakage maintenance material using of acrylic resin system water expansion, leakage maintenance material in this research, and present suitable form of construction work under these environment. also, wish to ready diversified remedy by oversea market opening.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.95-102
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• 2018

In order to understand interaction between building users' occupant performance and building maintenance performance of maintenance management personnel, actual data from maintenance activities of buildings were analyzed. Also, using building defect customer complaint data reported by building user, satisfaction data on building maintenance services of building users and service response time of maintenance management personnel, a method for evaluating interaction of buildings with the same purpose and same size was proposed. Throughout analysis, average number of occurrences per unit area per year for the mechanical complaints in complex building were presented. In addition, using building users' satisfaction with facility management services, attitude of responding to business obstacles, number of occurrences per unit area per year of mechanical complaints and complaint processing speed, interaction was comprehensively identified and compared.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.77-79
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• 2011

As residents and building owners demand maintenance that is required to achieve sustainable building performance, efficient building management methods are required. Even though the demand for maintenance systems is increasing, current maintenance work for high-rise buildings mostly uses conventional ropes and gondolas that pose a high risk of accidents and exhibit poor performance and efficiency. Thus, there is an urgent need to develop an automation robot system that can reduce accidents and improve the maintenance efficiency of the conventional high-rise building façade maintenance system. As a preceding work for the development of an automation robot system, this study classified and analyzed the work processes of actual construction sites and proposed basic techniques for the work mechanisms of the robot system by investigating the motions of cleaning workers.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.3
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• pp.10-18
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• 2016

This paper deals with the Performance Based Logistics(PBL) application scheme pertaining to optimal maintenance program for logistics of Korean Fighter Experimental(KF-X) Project. For enhancement of the performance based logistics system application to KF-X program the selection of appropriate standards fit to maximize cost-cutting, a set of performance metrics fit for the purpose of the contract, foreign technology dependence of core equipments and parts were considered. Thus, selecting appropriate standards fit for Korean logistics environment, domestic maintenance enterprise for stable rate of operation of KF-X, a systematic reliability task that is able to measure quantitative combat capability are suggested.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.186-195
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• 2007

Key Performance Indicators (KPIs) are the criteria of measuring project performance in order to attain construction excellence. Previous researchers have examined the abstract concept of success for general new construction and identified its relationship with the factors of success. In fact, most buildings exist to satisfy the needs of people. With the passing of time and change in technology, buildings have to be maintained and renovated in order to continue functioning properly for the benefits of users. Therefore, criteria and factors of success have increasingly attracted the attention of both researchers and practitioners, especially in cities where buildings become ageing. However, the topic of project success for maintenance projects is less discussed in previous research, and project participants, including maintenance surveyors should be able to identify the success measurement and its associated factors for performance improvement. This study fills the research gap by investigating the criteria and factors of success for maintenance projects. It first provides a summary of the literature review on the criteria and factors of success for construction projects. An empirical study has also been carried out with ten practitioners in Hong Kong to further identify the criteria and factors critical for the success of maintenance projects in practice. While most criteria and factors of success for new construction projects are also applicable to maintenance projects, participants in maintenance projects believe that effective communication is in particular important to provide quality service to the end-users.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.517-526
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• 2004

In the resent years, the early evaluation of concrete quality, construction and maintenance has been considered as all is of major concern due to the increase of loading and the degradation of structures related with time. This paper presents evaluation of structural safety performance using measured data of construction, on the basis of a field measurements for the prevention of unreliable concrete works. Measurements analyzed in this paper are early quality condition and performance assessment, serviceability performance by cracks and deflection, rating performance by loading, durability performance by chloride attack and carbonation. Thus, a quantitative assessment model of resistance capacity was developed here to meet the requirement for deteriorated concrete structures. The model focuses on damage mechanical of concrete structures deteriorated by initial damage factors for concrete quality and environment factors such as chloride and carbonation attacks. These results could provide useful information for concrete structures interested in design, construction and maintenance.