• Proceedings of the KSME Conference
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• 2003.04a
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• pp.610-616
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• 2003

Recently, the common concern of nuclear power industry in the development of technology mitigating and preventing the aging of steam generator tubes prevails, because the trends of steam generator flaws at Uljin unit #1,2 and KSNP(Korea Standard Nuclear Power Plant) impose a burden on the operation of nuclear power plant. While the regulatory agency is demanding the establishment of the advanced general performance maintenance system, the steam generator management program adapting advanced technology is being developed which may comply with EPRI PWR SG Guidelines based on NEI 97-06 ‘ General Guidelines including all the maintenance aspects consist of the tube integrity assessment criteria, repair limit, allowable leakage level, water chemistry will be composed in order to obtain the approval of regulatory agency and be applied to Nuclear power plant early 2005. This presentation is to introduce maintenance state including SG tube degradation and main contents of advanced SG management program being developed, and futhermore update present and future plan, and estimate the alternation after the completion.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.376-380
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• 2015

Life-Cycle Cost Analysis (LCCA) for highway projects is known as an effective analytical technique that uses economic principles to evaluate long-term alternative investment options, especially for comparing the values of alternative pavement design structures and construction strategies. In the Unites States, the 2012 Moving Ahead for Progress in the 21^st Century Act (MAP-21) amended the United States Code to mandate that the United States Government Accountability Office (GOA) conducts a study of the best practices for calculating life-cycle costs and benefits for the federally funded highway projects in 2013. The RealCost 2.5CA program was developed and adapted as an official LCCA tool to comply with regulatory requirements for California state highway projects in 2013. Utilization of this California-customized LCCA software helps Caltrans to achieve substantial economic benefits (agency cost and road user cost savings) for highway projects. Proper implementation of LCCA for roadway construction and rehabilitation would deliver noticeable savings of agency's roadway maintenance cost especially in developing counties where financial difficulties exist.

• Journal of Applied Reliability
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• v.17 no.3
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• pp.256-263
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• 2017

Purpose: This article provides the efficiency test results of conducting depot maintenance. Method: ANOVA (analysis of variance) and ANCOVA (analysis of covariance) tests are conducted using data obtained from Defense Logistics Integrated Information System (DELIIS). Results: The result shows that although the effect of the depot maintenance is significant, some parts do not follow the overall effect of the depot maintenance. In order to solve the problem we provide some suggestions to be improved. Conclusion: For improving the combat readiness condition of K-1 main battle tank, the maintenance policies and regulation must be revised for the parts of the weakness. In addition, the collection way of the operation and maintenance data must be redesigned.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.269-279
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• 2021

Purpose: The purpose of this study was to suggest weapon system specifications for requirements of Condition-Based Maintenance(CBM/CBM⁺). Methods: The military documents and case studies with regard to condition-based maintenance were reviewed. Representative Korea defense specifications of weapon system such as an aircraft, a C4ISR etc. were analyzed and investigated the level of requirement for maintainability was. Results: Condition-based maintenance was defined in both U.S. instruction and Korean directive. While deparment of defense(U.S.) provide a guidebook for CBM⁺, detailed instruction was not sufficient for Korean. Ministry of national defense(ROK) define the CBM⁺ by means of IPS element which should be developed along with the system development. The maintainability was barely included in Korean defense specifications, except for BIT(Built-in test) function. As a first step for defining the condition-based maintenance requirement in defense specification, this study suggests a standard form for data needed to acquire according to types of system, fault, failure, and so on. Conclusion: The empirical researches on CMB/CBM⁺ with domestic weapon systems are not enough, and a logic which leads the maintenance strategy to CMB/CBM⁺ is not solved. Through technical researches and institutional improvements including this study, we hope that condition-based maintenance would be fully established in the Korean defense field.

• Journal of Applied Reliability
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• v.16 no.4
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• pp.313-322
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• 2016

Purpose: We introduce ways to employ Markov chain model to evaluate the effect of preventive maintenance process. While the preventive maintenance process decreases the failure rate of each subsystems, it increases the downtime of the system because the system can not work during the maintenance process. The goal of this paper is to introduce ways to analyze this trade-off. Methods: Markov chain models are employed. We derive the availability of the system consisting of N repairable subsystems by the methods under various maintenance policies. Results: To validate our methods, we apply our models to the real maintenance data reports of military truck. The error between the model and the data was about 1%. Conclusion: The models developed in this paper fit real data well. These techniques can be applied to calculate the availability under various preventive maintenance policies.

• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.175-180
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• 2015

It is important to maintain information system (IS) following the business and institutional change. Even if successfully developed information systems, we cannot gain the benefit from the systems without the proactive maintenance activities. However, the importance of IS maintenance has not been considered as much as the system development, and we don't have any specific performance management structure. The objective of this study is to identify the relationship between IS maintenance activities and utilization. For empirical test of the hypothesis model, the sample data is collected from public information system sites. Results from multiple regression analysis reveal that proactive maintenance activities including IS maintenance cost increase, improving functionality, and enhancing ease of use have a causal effect on the IS utilization.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.4
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• pp.261-266
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• 2004

In this paper, the software reliability growth model which incorporates the periodic maintenance after the release is proposed. Using the proposed model, the debugging and periodic maintenance cost subject to the required level of the software reliability are investigated. An optimal software release time is derived for a fixed interval of periodic maintenance. To validate the proposed model, release times obtained in this study are compared with examples. The proposed investigation is expected to be served as one of factors in determining the release time of the software where periodic maintenance is considered.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.323-330
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• 2001

The regular maintenance and repair status of major farm machinery such as power tiller, farm tractor, rice transplanter and combine harvester etc., were surveyed and analyzed for the full-time farmers in order to get basic information for promoting farm machinery productivity. The survey was carried out through 209 farmers from 9 provinces. The results of this study can be summarized as follows; 1. The regular maintenance of farm machinery was conducted at repair shop(49.5%) or dealer agency(12.0%), and also conducted by farmers at their house(34.9%). 2. For the status on the cleanness or exchange times of engine oil, fuel filter and air cleaner, most farmers conducted fewer times than the necessary times. And, 5.3%, 7.7%, and 2.9% of surveyed farmers experienced breakdowns due to the insufficient cleanness or exchange oil, fuel filer, and air cleaner, respectively. 3. Most farmers(76.1%) recognized the necessity of farm machinery training or education, and they preferred one week for the training period, simple or easy maintenance for the training level, agricultural technical center or farm machinery manufacturer for the training agency. 4. Complete recognition of operation manual and sufficient maintenance before-, during-, and after-operation for the farm machinery can minimize the breakdowns, enlarge the endurance prevent the safety accidents, and promote productivity of farm machinery. And, these can be accomplished by the thorough training or education for agricultural machinery.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.2
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• pp.125-133
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• 2024

Objectives: The aim of this study is to develop a comprehensive Occupational Safety and Health (OSH) guide for maintenance tasks in semiconductor processing, specifically focusing on etching, deposition, and ion implantation processes. Methods: The development of the OSH guide involved a literature review, consultations with industry experts, and field investigations. It concentrates on Maintenance Work (MW) operations in these specialized areas. Results: The result is a detailed OSH guide tailored to MW in etching, deposition, and ion implantation facilities within semiconductor processing. This guide is structured to assist maintenance workers through pre-, during and post-MW phases, ensuring easy comprehension and adherence to safety protocols. It highlights the necessity of safety and health measures throughout the MW process to protect personnel. The guide is enriched with real-life scenarios and visual aids, including cartoons and photographs, to aid in the understanding and implementation of safety and health principles. Conclusions: This OSH guide is designed to enhance the protection of workers engaged in maintenance activities in the electronics sector, particularly in semiconductor manufacturing. It aims to improve compliance with safety and health standards in these high-risk environments.

• International Journal of Advanced Culture Technology
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• v.7 no.2
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• pp.125-136
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• 2019

This study focuses(selected) on garden facilities of designer gardens created at the 1st and 2nd Seoul Garden Shows and examined installed facilities at each designer garden by categorization according to type, material and functions. The study observed problems occurring from maintenance of garden facilities as time passes by and collected basic data to develop maintenance guideline aiming to make contribution to further spreading and promotion of high quality garden culture. This study examined all gardens created at 1st and 2nd Seoul Garden shows in 2015 and 2016. There were 18 gardens built in 2015 and 16 in 2015.The study looked at responsible entities for maintenance of facilities and examined maintenance system for managing these gardens. Garden facilities of the study were categorized into paving, facility for rest, playground, water facility, environmental sculpture and planting media facility according to categorization by landscape design standards and construction guidelines. Target gardens of this study are maintained mostly by citizen gardeners who are passionately carrying out maintenance work while communicating with designers. However, these citizen gardeners lack technical knowledge to manage various facilities. Also, maintenance manuals submitted by garden designers do not offer sufficient details on facility maintenance which calls for professional maintenance and clear instructions on facilities from early phase of design.