• 품질경영학회지
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• 제40권3호
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• pp.278-285
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• 2012

Purpose: Weapon systems have the long life cycle unlike the consumer product. Thus, the reliability of weapon system is improved during the life cycle through the steady technical change. In this paper, we deal with the method of evaluating the reliability of weapon system with the field failure data. Methods: Especially, we present how to gather the field failure data and evaluate the reliability through the case of K-series weapon system. To evaluate reliability, the reliability growth model is used and the result is discussed. Results: It is steadily improved the reliability of K-series weapon system deployed from 2000 to 2004. The frequency of the failures that affect the mission is largely reduced and MTBMF(mean time between mission failure) is also improved. Conclusion: We can guess the trend of the reliability of weapon system with the field data through this study. Furthermore, it can be used to improve the reliability and make maintenance policy.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2010년도 춘계학술대회
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• pp.157-160
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• 2010

Almost all companies have paid much attention to the safety management ranging from maintenance to operation even at the stage of designing in order to prevent accidents, but fatal accidents continue to increase throughout the world. In particular, it is essential to systematically prevent such fatal accidents sa fire, explosion or leakage of toxic gas at factories in order to not only protect economic losses and environmental pollution. In addition, HRA may be used to detect the human errors which may cause accidents or trace back to any mistake on the part of workers. This work focuses on the coincidence of human error and mechanical failure for management of human error, and on some important performance shaping factors to propose a method for improving safety effectively of the process industries.

• 대한방사선기술학회지:방사선기술과학
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• 제22권2호
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• pp.33-39
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• 1999

This paper included a data analysis of the unit of medical devices using mainternance recording card that had medical devices of unit failure mode, hospital of failure mode and MTBF. The results of the analysis were as follows : 1. Medical devices of unit failure mode was the highest in QC/PM such A hospital as 33.9%, B hospital 30.9%, C hospital 30.3%, second degree was the Electrical and Electronic failure such A hospital as 23.5%, B hospital 25.3%, C hospital 28%, third degree was mechanical failure such A hospital as 19.5%, B hospital 22.5%, C hospital 25.4%. 2. Hospital of failure mode was the highest in Mobile X-ray device(A hospital 62.5%, B hospital 69.5%, C hospital 37.4%), and was the lowest in Sono devices(A hospital 16.76%, B hospital 8.4%, C hospital 7%). 3. Mean time between failures(MTBT) was the highest in SONO devices and was the lowest in Mobile X-ray devices which have 200 - 400 failure hours. 4. Anverage failure ratio was the highest in Mobile X-ray devices(A hospital 31.3%, B hospital 34.8%, C hospital 18.7%), and was the lowest in Sono(Ultrasound) devices (A hospital 8.4%, B hospital 4.2%, C hospital 3.5%). 5. Failure ratio results of medical devices according to QC/PM part of unit failure mode were as follows ; A hospital was the highest part of QC/PM (50%) in Mamo X-ray device and was the lowest part of QC/PM(26.4%) in Castro X-ray. B hospital was the highest part of QC/PM(56%) in Mobile X-ray device, and the lowest part of QC/PM(12%) in Gastro X-ray. C hospital was the highest part of QC/PM(60%) in R/F X-ray device, and the lowest a part of QC/PM(21%) in Universal X-ray. It was found that the units responsible for most failure decreased by systematic management. We made the preventive maintenance schedule focusing on adjustement of operating and dust removal.

• 한국전자통신학회논문지
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• 제13권1호
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• pp.29-34
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• 2018

ESS가 연계된 시스템은 24시간 충 방전 스케줄링을 수행되어야 하므로 시스템이 중단되지 않고 운영, 관리되어야 하며, 전력 IT설비의 고장 발생이나 통신장애가 발생된 경우라도 ESS시스템의 스케줄링이 정상적으로 이루어져야 한다. 따라서, 다양한 장애가 발생하더라도 이를 능동적으로 대처하여 고정밀의 전력데이터를 수집, 관리하고 ESS 시스템을 제어하는 시스템이 요구되고 있다. 본 논문에서는 태양광 발전설비와 연계된 ESS 시스템을 대상으로 통신 장애 발생을 대처하는 통신 이중화된 전원관리유닛과 마이크로그리드 사이트 관리, 유지보수 및 모니터링을 수행할 수 있는 통합 관리 시스템을 제안한다.

• 디지털산업정보학회논문지
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• 제17권1호
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• pp.25-34
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• 2021

Availability is one of the important factor for developing weapon system, because it indicates the mission capability and sustainable life cycle management of weapon system. Recently, as weapon system becomes more advanced and more complex, availability estimation becomes more important to reduce the life cycle cost of weapon system. Modeling and simulation(M&S) is useful method to describe the availability of complex weapon system applying operational environment and maintenance plan. Especially agent based model(ABM) has the strength to describe interactions between agents and environments in complex system. Therefore, this paper presents the availability estimation of weapon system using agent based model. The sample data of part list and reliability analysis is applied to build availability estimation model. User agent and mechanic agent are developed to illustrate the behavior of operation and maintenance using formal specification. Storage reliability is applied to describe failure of each parts. The experimental result shows that this model is quite useful to estimate availability of weapon system. This model may estimate more reasonable availability, if full scale data of weapon system and real field data of operation is provided.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.87-91
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• 2015

For construction projects it is imperative that site management gives the highest priority to planning safe site evacuation for all foreseeable emergencies, including earthquakes and typhoons which are often experienced in Japan. This is especially important and even more critical for high risk projects involving underground works, such as Tunneling & Pneumatic Caissons. Based on the safety regulation of underground works, a back-up power supply system must be provided during the construction period at all times. Often, fluorescent lamps with re-chargeable batteries are provided for infrequent emergency cases, however these have a questionable useable life span and thus need careful maintenance and periodical replacement. In this paper we focused on using the phosphorescence materials to indicate the evacuation direction. As a result, it was confirmed that the phosphorescence materials were considered useful in reducing panic and facilitating a controlled evacuation in the event of a total black-out due to power failure.

• Journal of Chest Surgery
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• 제20권2호
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• pp.432-437
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• 1987

Pulmonary atresia with intact ventricular septum is a extremely rare congenital cardiac anomaly. With the history of cyanosis and failure to thrive, this anomaly should not be excluded and emergency management is necessary. Our patient was 69 day-old male with pulmonary atresia which was confirmed by cardiac angiography. Prostaglandin E1 was used for maintenance of pulmonary blood flow preoperatively. Right ventricular outflow reconstruction with pericardial patch and concomitant pulmonary valvotomy were done on beating heart for palliation. With this method, growing of right ventricle and tricuspid annulus are highly expected.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.594-601
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• 2000

Communication Based Train Control System supports the easy maintenance ＆ management and also have the capability to send more informations than the existing one but is less expensive. Tolerance against fault/failure and reliable data transmission are very important issues with this system since it has the responsibility of man's safety. In this paper, we suggested the schemes to support the reliable transmission quality and fault safety. Also we verified through simulation.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.23-28
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• 2017

The life management technology becomes important as the failure risk of the aged power transformers increases. Asset management technology, therefore, has been developed to evaluate the remaining life and build replacement strategies of power transformers, which enables an optimal investment decisions based on reliability and economic feasibility. The remaining life assessment technology uses data related to such as installation, operation, maintenance, refurbishment, and disposed history of power transformers. The optimal investment decision additionally uses data related to failure and social costs. To develop the asset management technology in power transformers, it is important to find deterioration parameters directly indicating degradation of power transformers. In this study, 110,000 DGA data during the past 35 years have been analyzed in order to find the deterioration parameters related to the degradation of power transformers. The alarm rates of combustible gases ($H_2$, $C_2H_2$, $C_2H_4$, $CH_4$, $C_2H_6$), TCG CO, and $CO_2$ were analyzed as deterioration parameters. The origin of the gas was discussed in connection with discharge, overheating and insulation aging.

• Clinical and Experimental Pediatrics
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• 제57권8호
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• pp.337-344
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• 2014

Inherited bone marrow failure syndrome (IBMFS) encompasses a heterogeneous and complex group of genetic disorders characterized by physical malformations, insufficient blood cell production, and increased risk of malignancies. They often have substantial phenotype overlap, and therefore, genotyping is often a critical means of establishing a diagnosis. Current advances in the field of IBMFSs have identified multiple genes associated with IBMFSs and their pathways: genes involved in ribosome biogenesis, such as those associated with Diamond-Blackfan anemia and Shwachman-Diamond syndrome; genes involved in telomere maintenance, such as dyskeratosis congenita genes; genes encoding neutrophil elastase or neutrophil adhesion and mobility associated with severe congenital neutropenia; and genes involved in DNA recombination repair, such as those associated with Fanconi anemia. Early and adequate genetic diagnosis is required for proper management and follow-up in clinical practice. Recent advances using new molecular technologies, including next generation sequencing (NGS), have helped identify new candidate genes associated with the development of bone marrow failure. Targeted NGS using panels of large numbers of genes is rapidly gaining potential for use as a cost-effective diagnostic tool for the identification of mutations in newly diagnosed patients. In this review, we have described recent insights into IBMFS and how they are advancing our understanding of the disease's pathophysiology; we have also discussed the possible implications they will have in clinical practice for Korean patients.