• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.216-221
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• 2011

An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.

• 한국IT서비스학회:학술대회논문집
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• 2008.05a
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• pp.266-271
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• 2008

유지보수 내용에 대한 사용자의 의견 수렴에 대한 요구사항 정의나 각 단계별 산출물 등에 대한 표준지표 등이 존재하지 않아 각각의 사업이나 시스템 별로 유지보수를 수행할 때마다 경험만을 기반으로 한 정성적인 작업이 이루어지게 되어, 유지보수 작업과 비용이 초과로 투입되는 등의 문제점들이 발생하였다. 이런 문제를 해결하고 유지보수성을 향상시키기 위해 유지보수에 대한 서비스 수준의 정확한 문제점 파악과 발생 문제점들에 대한 분석이 필요하게 되었다. 본 논문에서는 기존의 표준 유지보수절차에 대해 연구하고 SLA를 적용한 유지보수 프로세스인 서비스 지향 유지보수 프로세스를 제시하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.347-350
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• 2008

유지보수 활동이 전체 프로젝트의 중요한 비중을 차지하면서 유지보수를 수행하기 위한 비용의 증가가 이루어져 왔다. 하지만 유지보수를 수행하고 관리하는데 사용되는 지표나 지침, 표준문서 등이 구체적으로 마련되지 않다. 유지보수 성능 수준을 향상시키고 유지보수를 평가, 관리하는데 있어 사용 할 수 있는 측정지표 등이 연구되어야 할 것이다. 본 연구에서는 자산관리를 위해 사용되는 유지보수스코어카드를 바탕으로 소프트웨어 유지보수 형태에 따라 유지보수 비용의 감소와 분석에 효과적으로 사용할 수 있는 측정지표와 정량적 계산이 가능한 비용 측정지표에 대하여 연구한다.

• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.151-162
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• 2013

Due to a growing demand for the second-hand product, especially for the expensive one, the warranty and maintenance policies for such products have been studied to improve the product reliability of late. In this paper we study a periodic maintenance model for the second-hand product which is purchased by the customer at the age of $x$. When purchased, the dealer provides a warranty of a fixed length during which the product is maintained periodically to reduce the failure rate of the product and thus, to improve the reliability after each maintenance is served. If a failure occurs between two successive maintenances, only minimal repair is conducted. As for the warranty policy, we adopt free non-renewing repair action on each failure, in addition to the periodic maintenance service during the warranty period. Thus, under the given warranty policy, all the maintenance and repair costs incurred during the warranty period are charged to the dealer. For the proposed periodic maintenance scheme, we formulate a cost model to evaluate the expected total cost charged to the dealer during the warranty period and derive an optimal upgrade level of the failure rate at each maintenance to minimize the expected total warranty cost from the perspective of the dealer. We also present numerical results for an optimal upgrade level based on the proposed methods.

• 재활복지
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• v.17 no.4
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• pp.197-219
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• 2013

The aim of this study was to examine self-efficacy and work ethic on the moderating effect of retraining program for personal assistants to influence job environments and job satisfaction. The data were obtained from 330 personal assistants working at the Personal Assistance Association of Gyeonggi-do. The data were analyzed using the Structural Equation Modeling with relative effect analysis. The result of this study showed that self-efficacy and work ethics should have an impact job environments and job environments should have a positive impact job satisfaction. The retraining program for personal assistants showed a moderating effect on the relationship between work ethics and job environments. However, the findings did not support the moderator effect on the retraining program for personal assistants in the relationship between self-efficacy and job environments. Using these findings, social work administration agency, in particular, can be guided in terms of human resource management under social work administration.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.191-193
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• 2023

본 연구에서는 사회복지시설에 근무하고 있는 사회복지사의 직무만족도에 영향을 미치는 개인적 요인과 조직요인의 주요변수를 검증하여 사회복지사의 직무만족도를 높일 수 있는 정책적, 실천적 방안을 모색하기 위해 진행되었다. 분석자료는 2017년 사회복지 종사자의 보수수준 및 근로여건 실태조사 패널데이터 중 사회복지사 자격증을 갖고 근무하고 있는 사회복지사 8,075명을 분석에 사용하였다. 분석결과, 첫째, 사회복지사의 직무만족도는 보통이상(3.40점)이었다. 둘째, 사회복지사의 직무만족도에 영향을 미치는 개인적 요인으로 성별, 연령대, 결혼지위, 이직의도로 나타났고, 조직요인으로 총 보수액, 노동강도 대비 보수수준, 인권보장정도, 시설안전도, 시설유형 변인이 유의미한 영향을 미치는 것으로 분석되었다.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.475-481
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• 2017

As the research about supplementary education of radiological technologist who works in Gyoungsangnam province, this study was conducted to draw the improvements by analyzing the satisfaction level and problems of the supplementary education. During November 01, 2016 to December 15, 2016, after we sent out a total of 250 questionnaires for the survey to radiological technologists working at medical institution located in Gyoungsangnam province, 200 questionnaires suitable for research were analysis by using SPSS 18.0 statistical analysis software. As the satisfaction factors, 21 items such as system, subject, help, appropriateness of lecturer selection, professionalism were used. And as the problem factors, 18 items such as place, transportation, diversity, administrative treatment, education promotion, proceed method were used. Consequentially, the satisfaction level(3.12 point) and problems(3.01 point) of the supplementary education were confirmed as normal level. The supplementary education is an essential education that any health and medical service personnel must complete. In order to improve the effectiveness and efficaciousness of the education, the diverse opinions and efforts to improve the education levels must be supported. Futhermore, through the realistic educational program, the continuous education for radiological technologist with excellent qualities and competence should be done.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.861-868
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• 2018

As the research about supplementary education of radiological technologist who works in medical clinics, this study was conducted to draw the improvements by analyzing the satisfaction level and problems of the supplementary education. During November 01, 2016 to April 30, 2017, after we distributed a total of 150 questionnaires for the survey to radiological technologists working at medical clinics located in Changwon-si, Gyoungsangnam province, 106 questionnaires suitable for research were analysis by using SPSS 18.0 statistical analysis software. As the sociodemographic characteristics, the age, gender, working period, level of education, and working department were used. And As the welfare factors, working environment, financial support, educational opportunity, medical support, working culture, etc. were used. As the satisfaction factors, 21 items such as system, subject, help, appropriateness of lecturer selection, professionalism were used. And as the problem factors, 18 items such as place, transportation, diversity, administrative treatment, education promotion, proceed method were used. Consequentially, the satisfaction level(3.02 point) of the supplementary education were confirmed as normal level. And the problems(3.18 point) of the supplementary education was analyzed a little higher. The supplementary education is the mandatory education that any health and medical service personnel must complete every three years for license re-issuance. There were many opinions that the supplementary education for radiologists working in various medical institutions did not meet the education level of radiologists working in the medical clinics. In order to improve the satisfaction of the supplementary education of medical clinic's radiological technologist, it should be improved the quality of education through a practical education program that reflects various opinions and improvements on conservative education.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.249-251
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• 2005

전력 산업구조개편으로 인하여 전력회사의 민영화가 진행됨에 따라 전력회사에서는 한정된 예산으로 배전계통을 운영함으로써 유지보수를 위한 충분한 여유가 없어지게 될 것이다. 이러한 환경에서 한정된 비용으로 계통의 신뢰도를 일정 수준 이상으로 유지해야만 하는 문제에 직면하게 되며, 이는 매우 어려운 일이다. 이를 위해서는 최소의 비용으로 최대의 유지보수 효과를 낼 수 있는 방법을 개발해야 하며, 최적의 유지보수 주기를 찾는 것이 중요한 문제라 할 수 있다. 본 논문에서는 이런 문제론 해결하기 위해, 유지보수 기기 선정 및 유지보수 주기를 결정하는데 있어 검증된 기법인 Reliability Centered Maintenance (RCM) 기법을 이용하였다. 배전계통 기기의 유지보수에 있어서 Four-state Markov 모델을 이용하여 기기의 유지보수에 드는 비용과 기기의 고장에 의한 정전비용 사이의 trade-off를 고려하여 총 비용이 최소가 되는 최적의 유지보수 주기를 찾고자 한다. 이를 위하여 기존의 모델에서 평균고장률(mean failure rate)을 사용한 것과는 달리 시변 고장률(time-varying failure rate)을 적용하였으며, 또한 유지보수에 따른 고장률의 감소도 고려함으로써 최적의 유지보수 주기를 결정할 수 있었다.

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.233-241
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• 1995

In this thesis, the fatigue tests were performed on a series of R /C beams repaired with co& crete-lmlyrner composites to investigate the fatigue bahavior. The three point loading system is used in the fatigue tests. In these tests, relations between the repeated loading cycles and mid-span deflections, number of repeated loading cycles when repaired beams were fractured, the bonding performance of repair materials were observed. On this basis, the mid-span deflections, the crack growth and failure mode of repaired R /C beams were studied. A S-N curve was drawn to present the fatigue strength of repaired beams. From the test results, it was shown that behavior of R /C beams repaired with polymer-cement series were very sirnillar to control beam about bonding performance, mid-span deflections and fatigue strength according to S-N curve drawn by the regression anlysis on the fatigue test results.