• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.1-10
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• 2023

The nuclear power plant(NPP)'s Instrumentation and Control(I&C) system periodically conducts integrity checks for the maintenance of self-diagnostic function during normal operation. Additionally, it performs functionality and performance checks during planned preventive maintenance periods. However, there is a need for technological development to diagnose failures and prevent accidents in advance. In this paper, we studied methods for estimating the reliability function by utilizing environmental data and self-diagnostic data of the I&C equipment. To obtain failure data, we assumed probability distributions for component features of the I&C equipment and generated virtual failure data. Using this failure data, we estimated the reliability function using representative artificial intelligence(AI) models used in survival analysis(DeepSurve, DeepHit). And we also estimated the reliability function through the Cox regression model of the traditional semi-parametric method. We confirmed the feasibility through the residual lifetime calculations based on environmental and diagnostic data.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.80-86
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• 2019

As computer performance improves, research using deep learning are being actively carried out in various fields. Recently, deep learning technology has been applying to the safety evaluation for structures. In particular, the internal blades of a turbine structure requires experienced experts and considerable time to detect surface damages because of the difficulty of separation of the blades from the structure and the dark environmental condition. This study proposes a Faster R-CNN deep learning model that can detect surface damages on the internal blades, which is one of the primary elements of the turbine structure. The deep learning model was trained using image data with dent and punch damages. The image data was also expanded using image filtering and image data generator techniques. As a result, the deep learning model showed 96.1% accuracy, 95.3% recall, and 96% precision. The value of the recall means that the proposed deep learning model could not detect the blade damages for 4.7%. The performance of the proposed damage detection system can be further improved by collecting and extending damage images in various environments, and finally it can be applicable for turbine engine maintenance.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.41-48
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• 2009

I collected the cases of CNG vehicle accidents which had happened for 30 years and analyzed the causes of the accidents according to each type of cylinders. There are about six accidents including three cylinder explosion accidents due to bad heat treatment, one composite damage, one CNG vehicle fire, and one fuel piping accident owing to the poor maintenance. When looking into the cylinder types involved in the accidents and the causes, 29% of the cylinder accidents are Type I and 24% Type IV, 16% Type II, and 14% Type III. 37% of the accidents are caused by the defects of the raw materials and the errors of a manufacturing process, 16% by the stress corrosion cracking as a result of the repetitive use, 15% by the cylinder's explosion on account of the malfunction of PRD(Pressure Relief Device) and the overpressure. The remainders of the causes are fire and unknown causes. Therefore, cylinder manufacturers have to strengthen quality management of raw materials and manufacturing process and painting regardless of each type of cylinder. Also bus operators need to make an effort to keep safety condition through every day check.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.245-251
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• 2018

This study was conducted to investigate the status of the installation, maintenance and management of automatic external defibrillators (AEDs) in all mandatory institutions and buildings of the providence to be equipped with AEDs. The study was conducted from November 20, 2017 to December 20, 2017, during which time 169 AED units were surveyed. The collected data was analyzed by frequency analysis and the percentage was determined using the SPSS/WIN 20.0 program. A total of 168 units (99.41%) of AEDs were installed inside. Additionally, 47 units (27.80%) were available 24 hours a day, and 44 units (26.00%) were available outside business hours of the institution. Moreover, 87 units (51.43%) of the responsible managers received rescue and first aid training. Evaluation of the management status of the AEDs revealed two (1.20%) that had problems with their battery state of charge battery charge and seven (4.10%) for which the AED pads were past the expiration date. A management system for the manager of AEDs should be established and a regular training program for their systematic maintenance should be developed and applied. It is also suggested that awareness of the necessity of continuous management be raised through reinforcement of laws and legal system reorganization.

• The Journal of Society for e-Business Studies
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• v.25 no.2
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• pp.29-48
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• 2020

For the visualization of outcome is relatively limited in informatization filed especially, systematic and quantifiable performance management of IT projects and policies is needed. Thus, the government developed its informatization evaluation system and has reinforced it. And Ministry of National Defense (MND) continues to strive for the settlement of the informatization performance evaluation system as well. According to Defense Informatization Law which was legislated in 2011, informatization policies should be assessed annually through informatization policy evaluation system in terms of their enforcement and outcome. However, informatization policy evaluation has not carried out since its pilot enforcement just after the legislation of the law. Hence, we conducted informatization policy evaluation aimed at performance investigation of 31 policies in '14~'18 Defense Informatization Master Plan. We sophisticated the current informatization policy system and we provide guidelines and tools to support the development of performance goal and indicators for each of the policies. Then, the policies were assessed by the evaluation committee we organized for our study, and we analyzed the problems we tackled in the whole process of evaluation and provided proposals for effectiveness enhancement of defense informatization evaluation system. The proposals will be meaningful for performance management in defense informatization sector and in public informatization sector as well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.535-545
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• 2019

The PBA of ship weapon system should be installed and operated under harsh environmental conditions and so it should be highly reliable to endure the mission profiles during its entire lifetime. In the case of PBA failure during operation, rapid maintenance is highly likely to be difficult due to problems such as supply of parts, which can have a devastating effect on the mission. In order to validate the reliability of PBA, a series of tests are performed with PBA samples, but they require time, testing facilities, samples, expenses and failure analysis if failed. The reliability of PBA is predicted on the basis of specifications such as MIL-HDBK-217F, but this specification does not take into account failure mechanisms for specific design details, environment and usage, interconnects and its characteristics that drive many failures of PBA in the field. Therefore, this study predicts the reliability of PBA using an RPA tool and proposes the RPA methodology as a validation process at the design stage. With RPA, it is now possible to achieve design validation including inherent failure mechanism, identification of weakest link, alternative design options, and test plan development.

• Fire Science and Engineering
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• v.6 no.2
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• pp.15-24
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• 1992

우리나라는 1960년대의 경제개발계획에 따른 공업화 시축의 추진으로 산업의 발달과 경제성장은 인구를 도시로 집중시키면서 도시건축물은 대형화, 고층화, 과밀화 현상을 가져왔다. 한편, 국민생활의 향상과 산업활동의 다양화로 화재발생의 주요원인이 되는 전기, 가스, 유류등의 사용량이 해마다 늘어나고 있어 화재의 위험을 가중시키고 있다. 최근 10연간('81~'90) 전국에서 발생한 화재사고는 9만 5,154건이 발생하여 인명피해 1만1,117명, 재산피해 1,859억 2,200만원의 많은 손실을 가져 왔으며, 이 중에는 서울에서 발생한 화재가 3만6,089건으로 전체의 37.9%을 차지하고 있다. 화재가 발생할 경우 대형 참사를 방지하고 귀중한 인명피해는 물론 경제적 손실을 최저로 줄일 수 있는 소방시설을 도시건축물에 설치하여 이에 대비하는 것이 무엇보다 귀중한 일이다. 이는 화재예방 또는 발생 초기에 이를 감지, 통보하고 피난하며 소화활동에 이르는 모든 방재 및 소화를 위한 소방시설의 유용성을 최대로 발휘할 수 있기 때문이다. 본 논문에서는 서울특별시를 중심으로 도시건축물에 설치된 소방시설의 유지 관리 실태와 화재시 소방시설의 이용실태를 분석하여 문제점을 도출하고 이에 대한 개선방향을 제시하므로서 예방소방행정의 발전을 기하고저 하였으며, 그 내용을 요약하면 다음과 같다. 제1장에서는 서론부분으로서 연구의 목적과 범위및 접근 방법을 서술하였고, 제2장에서는 도시소방행정의 특성 및 소방환경의 변화로 먼저 소방행정의 의의와 도시소방행정의 유형으로 예방소방과 진압소방 그리고 구급.구조업무등을 살피고. 도시소방환경변화에 따른 화재발생추세를 살펴 보았다. 제3장에서는 도시건축물에 설치하는 소방시설의 설치.유지 및 이용실태를 검사.분석하였다. '90년도 서울시내 소방서에서 실시한 소방대상물에 대한 소방검사와 방화관리자에 대한 설문조사를 실시하여 소방시설의 유지관리실태를 통계.분석한 결과, 소방시설이 양호한 소방대상물은 전체의 75.9%이며, 불량소방대상물은 24.1%로 나타났다. 그리고 화재가 발생한 소방검사대상물에 대한 화재현장 조사결과 화재시 소방시설을 사용한 소방대상물은 전체의 72.1%를 차지하고 있다. 제4장에서 는 소방시설의 문제점으로 \circled1 소방설비부실공사, \circled2 소방시설 유지관리능력부족, \circled3 소방검사제도 불합리등이며, 이에 대한 개선방향으로 \circled1 소방설비 시공자의 지도. 감독강화, \circled2 자체시설관리능력향상, \circled3 예방소방행정제도의 개선을 제시하였다. 제5장은 결론으로, 우리나라가 최근 경제성장과 산업의 발달로 도시건축물의 화재발생 위험이 가중되면서 이에 대한 소방안전대비책이 요구된다. 이에는 도시건축물에 방화시설과 소방시설을 완비하고, 그리고 자격있고 유능한 방화관리자 선임하여 자체 소방계획을 수립하여 시설점검, 정비와 유지관리를 철저히 한다면 어떠한 화재도 예방 또는 초기에 진압할 수 있고, 또한 입주검자에 대한 소방교육 및 훈련을 지속적으로 수행하여 나간다면 여하한 도시건축물의 소방안전도 그 목적을 달성하리라고 생각한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.435-440
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• 2004

연안침수지도는 태풍이나 해일에 의한 연안침수 발생 시 방조제의 월류 및 붕괴로 인한 예상 침수구역을 강우빈도(200년)별로 나타내고, 침수면적과 깊이를 표현한 지도로서 국외 선진국에서 방재형 국토관리 정책결정과 침수피해에 대한 대민 홍보의 수단으로 활용되고 있다. 국내에서도 연안침수에 의한 피해가 나날이 커지고 국토의 개발에 따른 자연 재해가 많아짐에 따라 보다 방재형 국토개발로 국민의 안전과 복리를 증진하고, 연안침수에 의한 피해를 최소화하기 위한 노력의 일환으로 연안침수지도의 제작 필요성이 증대되고 있다. 본 연구의 시범지역인 대부도 남부지역의 GIS 데이터베이스 구축은 문헌조사 및 기구축 데이터 확보, 지역의 특성에 맞는 신규 GIS 데이터베이스 구축 방법을 제시하였다. 침수구역을 예측하기 위한 모델링을 지원하기 위한 정확도와 경제성, 객관성, 현실성이 높은 지형공간자료의 효율적인 구축이 강조되었다. 구축한 데이터베이스의 세부 유형은 침수위험구역, 침수경계구역, 침수량 화살표이며, 기존에 구축된 데이터를 활용한 레이어는 해안선, 도로, 건물, 등고선, 등심선, 연안 표고점 측량데이터이다. 연안침수지도는 효율적인 재난관리를 위하여 다양하게 활용될 수 있을 것으로 사료되며 나아가 주민의 침수에 대한 경각심 고취와 사전 교육, 지방자치단체의 침수위험 관리업무의 활용이 가능할 것으로 사료된다. 본 연구에서 제작된 연안침수지도는 지자체 주민들을 위해 보기 쉽고 다양한 정보를 얻을 수 있도록 제작되었으며, 이를 위해 사진과 삽화를 추가하여 주민들에게 침수피해에 대한 경각심과 이해를 높이는데 중점을 두었다. 유지관리 후 활용체계 정비의 중요성’을 점검하고, ‘변동자료 발생원인의 분석’, ‘명확한 변동자료 입력 근거의 확보’, ‘갱신주체별 역할의 정의 및 유지관리 기준의 설정’, ‘분야별업무 특성을 고려한 관련 기준의 마련 및 타 시스템과 연계되는 항목을 고려한 절차 정의’ 등에 대한 다양한 접근을 시도하였다. 본 연구에서 제시하는 유지관리 모델을 기반으로 각 지자체별로 적절한 컨설팅이 진행되고 이에 따라 담당자의 실천이 이루어진다면 지자체 GIS의 투자대비 효과에 대한 기대는 이상이 아닌 현실로 다가오게 될 것이다.가오게 될 것이다. 동일하게 25%의 소유권을 가지고 있다. ？스굴 시추사업은 2008년까지 수행될 계획이며, 시추작업은 2005년까지 완료될 계획이다. 연구 진행과 관련하여, 공동연구의 명분을 높이고 분석의 효율성을 높이기 위해서 시료채취 및 기초자료 획득은 4개국의 연구원이 모여 공동으로 수행한 후의 결과물을 서로 공유하고, 자세한 전문분야 연구는 각 국의 대표기관이 독립적으로 수행하는 방식을 택하였다 ？스굴에 대한 제1차 시추작업은 2004년 3월 말에 실시하였다. 시추작업 결과, 약 80m의 시추 코아가 성공적으로 회수되어 현재 러시아 이르쿠츠크 지구화학연구소에 보관중이다. 이 시추코아는 2004년 8월 중순경에 4개국 연구팀원들에 의해 공동으로 기재된 후에 분할될 계획이다. 분할된 시료는 국내로 운반되어 다양한 전문분야별 연구에 이용될 것이다. 한편, 제2차 시추작업은 2004년 12월에서 2005년 2월 사이에 실시될 계획이다. 수백만년에 이르는 장기간에 걸쳐 지구환경변화 기록이 보존되어 있는

• 대한공업교육학회지
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• v.44 no.2
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• pp.86-103
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• 2019

The purpose of this study is to provide basic data on the development of education and training programs for training 'mechanical facilities maintenance manager'. To this end, the DACUM technique was used for job analysis and education and training programs were developed through expert consultation meetings. The job analysis was based on the 10-member DACUM Committee to derive the job definition, job model, job description, and task description of the 'mechanical facilities maintenance manager'. The main findings are as follows. First, the 'mechanical facilities maintenance manager' was defined as those who operate, inspect, diagnose, and repair mechanical facilities to provide the best performance and efficient operation management, provide a safe and pleasant environment, and perform energy saving and facility life extension tasks. Second, the duties of the 'mechanical facilities maintenance manager' analyzed in the job model consist of the comprehensive plan for operation of mechanical facilities, energy management of mechanical facilities, operation management of mechanical facilities, maintenance of mechanical facilities, safety environment management of mechanical facilities, and customer support management of mechanical facilities. Considering the nature and content of the duties, 4 to 11 tasks per duty were derived and a total of 33 tasks were presented as job model. Third, the curriculum for the 'mechanical facilities maintenance manager' was set up in two courses: Practice I for Mechanical Facilities Maintenance and Practice II for Mechanical Facilities Maintenance. Considerations and policy suggestions were presented when applying and implementing education and training programs based on the results of the research.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.84-92
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• 2020

Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.