• 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.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.263-273
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• 2019

South Korea's OF cable is reaching its expected design life of 30 years, and as a result, the risk of failure is increasing. Therefore, it is necessary to diagnose the long-term operating OF cables through accurate diagnosis at the right time to prevent the failure. Currently, the KEPCO periodically conducts DGA. However, the gas found in DGA is caused by oil deterioration as well as insulation paper. Therefore, the analysis of the degree of polymerization and furan compounds which is an evaluation of insulation paper considered to be the life of OF cables is required. In addition, the results of the evaluation of deterioration of insulation paper need to be checked for correlation with the results of DGA. In this study, DGA carried out through GC, the degree of polymerization was analyzed using an automatic viscometer, and HPLC was used to detect the furan compounds. In addition, the obtained results were applied to the SVM technique, which was recently introduced to determine abnormalities in OF cable. And the results which were accurate and reliable were obtained.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.1014-1016
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• 1998

Rupture of the bronchus following endotracheal intubation with a double-lumen tube is extremely rare in all complications of endotracheal intubation. We experienced a case of left main bronchial rupture following endotracheal intubation. This 58-year old female patient was diagnosed of well-differentiated adenocarcinoma of right lower lobe, stage IIB, preoperatively. She was intubated with Robertshaw double-lumen tube(35 Fr.) for Rt. lower lobectomy. Intraoperatively, Lt. main bronchial rupture was suspected because of pneumomediastinum and ventilation insufficiency and immediately repaired with monofilament absorbable sutures(PDS) through left thoracotomy. Postoperative course was uneventful.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.481-486
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• 2012

This thesis examines the development and application of 'Health Monitoring System' which monitors periodically the state of a pipe of petrochemical plant by using magnetostrictive sensor technology. The existing guided-wave inspection methods cannot be applied to welding part inspection in pipe, and has a limit of precision when applied to general parts because of noise, reflected waves, and so on. This technology uses the information on displacement of a defect through periodic monitoring, which makes more precise inspection, and can be utilized very usefully in a petrochemical plant.

• 건강소식
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• v.26 no.11 s.288
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• pp.6-13
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• 2002

지난 30여년 동안 급속한 경제 성장과 생활 양식의 변화는 우리 사회에 많은 변화를 초래하였고 한국인의 질병 양상에도 많은 영향을 주었다. 동물성 식품과 지방질 섭취의 증가, 신체활동 감소,노령인구 증가, 생활양식의 서구화 및 도시화 등은 한국인에서 만성질환의 발생과 이환을 증가시키고 있다. 통계청의 2001년 사망원인통계를 보면 1위가 암, 2위가 뇌혈관 질환, 3위가 심장질환, 4위가 당뇨병, 5위가 간질환으로 모두 잘못된 생활습관으로 인한 만성질환이다. 이중에서도 당뇨병은 지난 1991년 이후 암 다음으로 많이 증가한 질병으로 인구 10만명 당 23.8명이 당뇨병으로 사망했으며 하루 평균 당뇨병으로 31명이 사망한다. 2002년 4월, 대한당뇨병학회의 "한국인의 당뇨병 발생 현황 보고"에 따르면 우리나라 성인의 당뇨병 유병률은 10%선으로 최소 3백만명에서 최대 5백만명 정도가 당뇨병을 앓고있다. 우리나라는 식생활의 서구화, 고령화 등으로 당뇨병 환자가 급증하고 있어 생활 양식의 개선이 이루어지지 않을 경우 앞으로 10년 안에 전체 국민의 1/4정도인 1천2백만명 가량이 당뇨병으로 고통을 받게 될 것이라 한다. 당뇨병은 당뇨뿐만 아니라 그에 따른 만성 합병증이 매우 무서운 병으로 일단 발병하면 적극적인 치료에도 불구하고 정상으로 회복되기 어렵다. 따라서 합병증의 효과적인 예방을 위해서는 특별한 임상 증상이 없더라도 당뇨병을 처음 진단 받은 날부터 주기적인 검진을 통하여 조기에 발견해 낼수 있도록 노력하여야 한다. 이와 더불어 주기적인 혈액 검사와 주치의 면담을 통하여 정상 혈당을 유지할 수 있는 혈당 조절 방법과 함께 만성 합병증을 예방할 수 있는 생활 습관 개선(금연, 금주,표준체중 유지,규칙적 운동,정상 혈압 유지,정상 혈중 지질 유지등)을 반드시 실천하여야 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.106-106
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• 2012

인체 내 소량의 생체성분을 감지하는 바이오센서 기술은 질병 진단뿐만 아니라 예방 및 관리로 의료서비스 확대 및 의료비 감소 효과를 가져올 수 있는 기술이다. 광 바이오센서는 광학적인 측정방법을 이용하여 다양한 생화학물질들의 상호 반응을 검출해 낼 수 있는 바이오센서로 현재 활발하게 연구가 진행되고 있다. 일반적으로 형광물질, 발색물질 등의 발광물질을 인식물질에 표지하여 인식물질과 분석물질과의 반응 유무를 표지된 발광물질의 광 신호를 감지하여 분석물질을 검출해내는 표지식 광 바이오센서 기술이 상용화되고 있다. 그러나 이러한 분석 방법은 민감도는 우수하지만 분석 시간이 매우 느리고, 고가의 분석 장비를 필요로 하는 단점들을 가지고 있다. 이러한 단점들을 극복하기 위하여 생화학 반응 유무를 표지물질 없이 광학적 방식으로 직접 측정해내는 비 표지식 광 바이오센서 기술이 최근 들어 많이 연구되고 있다. 본 논문에서는 비표지식이면서 분광기 없이 분석 가능한 공진 반사광 바이오센서 기술에 관한 내용을 소개하고자 한다. 공진 반사광 바이오센서는 광파장 이하의 주기를 가진 주기적 공진 격자 표면에서 일어나는 항원-항체 반응에 대한 공진 반사 파장을 측정하여 원하는 바이오물질을 고감도로 검출할 수 있는 바이오센서이다. 또한, 인체 내장을 위하여 플렉시블 기판 상에 GaN LED를 집적하여 전립선암 바이오 마커 검출에 대한 결과를 소개하고자 한다.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.347-359
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• 1996

Adenoid cystic carcinoma is an uncommon histologic variant of adenocarcinoma which usually arises from the salivary, lacrimal, or other exocrine glands. Characteristics of adenoid cystic carcinoma are its potential for extending long distance submucosally and for perineural invasion. It grows slowly and may have a prolonged course before diagnosis and after treatment. Recently, we have experienced 2 cases of adenoid cystic carcinoma arising from main bronchus and trachea. One case was 58 years old female patient. Her symptoms were productive cough with dyspnea. She has been history of shortness of breath, wheezing and cough during 4 years, which was initially diagnosed as bronchial asthma. The tumor was located on the left main stem bronchus which was obstructed the lumen nearly complete, by CT demonstration. Tissue diagnosis was confirmed as adenoid cystic carcinoma by bronchoscopic biopsy. The patient underwent radiation to relieve a bronchial stenosis caused by her tumor. The patient has remained well and is asymptomatic without evidence of clinical recurrence. The other case was 25 year old female. She complained shortness of breath and inspiratory difficulty during sleep. The tumor was located in upper trachea, which protruded from the posterior wall of the trachea and obstructed the lumen nearly complete, by CT demonstration. Tissue diagnosis was confirmed as adenocystic carcinoma by rigid bronchoscopic biopsy. The patient was underwent operation for removal of the mass and received radiotherapy. The patient has remained well are following up now.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.649-662
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• 2017

Since 1980, the number of universities have increased dramatically. However, compared to the quantitative growth, the lack of qualitative growth has often been criticized. Students entering university are estimated to decrease by half in 2025 compared to 2014. In swift response to challenges with decreasing student enrollment, the first University Reform Evaluation (URE) for innovating universities, was conducted and resulted in controversy. Opposition is based on distrust of the overall system, questioning the reliability of the evaluation process utilized for the URE evaluation index. Meta-evaluation is required to improve the quality of evaluation, and standards developed prior to conducting the URE. Therefore, an interdisciplinary approach is necessary for the evaluation of human resource development. This research uses the interdisciplinary approach from the human resources development point of view in attempting to develop meta-evaluation criteria which will enable effective evaluation and analysis of URE. The meta-evaluation standard features the creation of the ERPOU model, by conducting literature review, and considers data from expert symposiums, and surveys. The ERPOU model consists of 5 evaluation fields, 21 evaluation categories, and 42 evaluation standards.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.31-40
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• 2012

The irregularity of railway track affects not only the comfort of ride such as noise or vibration but also the safety of train operation. For this reason, it is an interesting research area to design a reliable and sustainable railway track system and to analyze the train movement mechanism based on systematic approaches considering reasons of track irregularity possible in a specific local environment. Irregularity data inspected by EM-120, an railway inspection system in Korea includes unavoidable incomplete and erratic information, so it is encountered lots of problem to analyse those data without appropriate pre-data-refining processes. In this research, for the efficient management and maintenance of railway system, progress rate of standard deviation of irregularity is quantified. During the computation, some important components of railways such as rail joint, ballast, roadbed, and fastener have been considered. Probabilistic distributions of irregularity growth with respect to time are computed to predict the remaining service life of railway track and to be adapted for the safety assessment.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.133-138
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• 2018

Safety management has become even more important because of the safety and environmental issues that have arisen since the 2000s. However, the safety study requires many empirical data, so there are many limitations. In the case of pipe safety, simulation programs exist, but it is difficult to get data about the pipe internal erosion of the pipe. In this study, the erosion rate of the pipe elbow was simulated using computational fluid dynamics (CFD). Also, the failure period of the pipe was calculated by the limit state function using erosion rate. In the case of CFD pipe, a sample which is actually operated in Yeosu industrial complex was used, and the geometry and mesh formation were rationalized in terms of typical fluid dynamics simulations. Using the Discrete Phase Model (DPM) and the corrosion model, the erosion rate ($3.09227mm{\cdot}yr^{-1}$) was obtained from CFD simulations. As a result of applying the erosion rate to the limit state function, we obtained the pipe failure period value, 14.2 years to trigger a leak and 28.2 years to trigger a burst. Through these processes, we concluded that pipe erosion is one of the major failure modes. In addition to the results, this study has significance for suggesting the methodology of the pipe safety study.