• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1887-1894
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• 2024

Fatigue strength of the structural materials of lead-cooled fast reactors (LFRs) and accelerator-driven systems (ADS) may be degraded in liquid metal (Lead or lead-bismuth eutectic (LBE)) environments. The fatigue crack growth (FCG) data of structural materials in liquid LBE are necessary for damage tolerance design, safety assessment and life management of key equipment. A novel monitoring system for fatigue crack length was designed on the compliance method and the monitor technology of crack opening displacement (COD) of CT specimens by the linear variable differential transformers (LVDT) system. It can be used to predict the crack length by monitoring the COD of CT specimens in harsh high-temperature liquid LBE using a LVDT system. The prediction accuracy of this system was verified by FCG experiments in room temperature air and liquid LBE at 150, 250 and 350 ℃. The first results obtained in the FCG test for T91 steel in liquid LBE at 350 ℃ are presented.

• 분석과학
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• 제26권5호
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• pp.315-325
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• 2013

The possibility of acute hepatotoxicity caused by dimethylformamide (DMF) requires regular monitoring of the workers who are using DMF to prevent the occupational disease. The authors performed ambient and biological monitoring of workers involved in synthetic leather manufacturing processes using DMF to assess the correlation between the markers of ambient and biological monitoring of DMF. The authors monitored 142 workers occupationally exposed to DMF from 19 workshops in the synthetic leather and ink manufacturing industries located in northern region of Gyeonggi-do. The subjects answered questionnaire on work procedure and use of personal protective equipment to be classified by exposure type. DMF in air samples collected using personal air samplers, diffusive and active sampler, was analysed using gas chromatograph-flame ionization detector (GC-FID) with DB-FFAP column (length 30 m, i.d. 0.25 mm, film thickness 0.25 ${\mu}m$). Urinary N-methylformamide (NMF) was analysed using gas chromatograph-mass selective detector (GC-MSD) at selected ion monitoring (SIM) mode with DB-624 column (length 60 m, i.d. 0.25 mm, film thickness 1.40 ${\mu}m$). Geometric mean (GM) and geometric standard deviation (GSD) of the ambient DMF was $6.85{\pm}3.43$ ppm, and GM and GSD of urinary NMF was $42.3{\pm}2.7$ mg/L. The ratio of subjects with DMF level over 10 ppm was 44%, and those with urinary NMF over 15 mg/L was 87%. NMF in urine adjusted by DMF in air was $4.61{\pm}2.57$ mg/L/ppm and $9.50{\pm}2.41$ mg/L/ppm, respectively, with or without respirator. There was seasonal differences of NMF in urine adjusted by DMF in air, $7.63{\pm}2.74$ mg/L/ppm in summer and $4.53{\pm}2.29$ mg/L/ppm in winter. The urinary NMF concentration which corresponds to 10 ppm of ambient DMF was 52.7 mg/L (r=0.650, n=128). Considering the difference of the route of exposure which resulted from the compliance of wearing personal protective equipment, the estimated contribution of respiratory and dermal exposure route for DMF was 48.5% vs. 51.5%.

• 한국안전학회지
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• 제32권2호
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• pp.78-84
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• 2017

Subcontractors have an increased risk of accidents compared to large contractors. Subcontractors' safety management system is in close association with workers in construction sites. Contractors should strengthen subcontractors' roll and responsibility and provide continual support to prevent an accident. And also these supporting system should be provided to subcontractors' headquarters as well as construction site. Contractors' priority management for subcontractors safety should be transferred from the post management for disciplinary action to the preventive management to improve subcontractors participation and safety performance. Subcontractors can not establish the safety management system with just a one time supporting only. Contractors support and monitoring should be provided to subcontractors regularly and continuously to establish their self safety management system. The subcontractors safety management system improvement program(SSMSIP) suggested in this study will be a effective supporting system for subcontractors to establish and improve their safety management system. If we carry out the objective and quantitative evaluations and supporting system such as SSMSIP and provide the consequential incentive program to subcontractors, it can contribute to the accident reduction.

• 비파괴검사학회지
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• 제31권3호
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• pp.278-286
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• 2011

The on-line monitoring for the wall thinning in secondary system has been considered one of main issues for the safety of nuclear power plants. To establish the on-line monitoring technique for the pipe wall thinning, the development of the ultrasonic transducer working in high-temperature is very important. In this investigation, the magnetostrictive transducer is concerned for high temperature condition up to $300^{\circ}C$. The magnetostrictive transducer has many advantages such as high working temperature, durability, cost-effectiveness, and shear waves, most of all. A thin Fe-Co alloy patch whose Curie temperature is over $900^{\circ}C$ was employed as a ferromagnetic material for magnetostriction. Wave transduction experiments in various temperature were carried out and the effect of bias magnets was considered together with the dry coupling performance of the transducer. From experimental results, consequently, it was found that the magnetostrictive transducer works stable even in high temperature up to $300^{\circ}C$ and can be a promising method for the on-line monitoring of the wall thinning in nuclear power plants.

• 한국정보통신학회논문지
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• 제19권3호
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• pp.724-730
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• 2015

각종 산업현장의 현장 작업자들이 안전 벨트를 제대로 착용하지 않아서 발생하는 안전사고는 매년 꾸준히 증가하고 있는 추세이다. 본 논문에서 제안하는 개인 안전벨트 모니터링 시스템은 작업자가 안전벨트를 착용하지 않고 작업을 진행할 경우 알림음을 울림으로써 작업자가 안전벨트를 제대로 착용하도록 하였다. 또한 그와 동시에 관리자가 실시간으로 작업자들의 안전 벨트 착용 여부를 모니터링함으로써 안전장비를 제대로 착용하지 않아서 발생하는 안전사고를 예방할 수 있도록 하였다.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.417-428
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part III, the local damage of the rigid components of aircraft, e.g., engine and landing gear, impacting the steel concrete (SC) structures of NPP containment is mainly discussed. Two typical SC target panels with the thicknesses of 40 mm and 100 mm, as well as the steel cylindrical projectile with a mass of 2.15 kg and a diameter of 80 mm are fabricated. By using a large-caliber air gas gun, both the projectile penetration and perforation test are conducted, in which the striking velocities were ranged from 96 m/s to 157 m/s. The bulging velocity and the maximal deflection of rear steel plate, as well as penetration depth of projectile are derived, and the local deformation and failure modes of SC panels are assessed experimentally. Then, the commercial finite element program LS-DYNA is utilized to perform the numerical simulations, by comparisons with the experimental and simulated projectile impact process and SC panel damage, the numerical algorithm, constitutive models and the corresponding parameters are verified. The present work can provide helpful references for the evaluation of the local impact resistance of NPP buildings against the aircraft engine.

• 자동차안전학회지
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• 제15권4호
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• pp.58-64
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• 2023

The adoption of hydrogen-powered Elec is expanding globally. Hydrogen is recognized as a potentially hazardous energy source, and safety assessment is crucial for the development of plans to supply hydrogen-powered electric buses. Hydrogen gas leakage can have a significant impact during bus operations, and continuous hydrogen leakage in hydrogen-powered vehicles can result in fatal accidents. In this study, information about hydrogen leakage is collected through sensors installed within the vehicles and is measured when the sensor detects a leak. The study also proposes the use of Pseudo Fuel Leakage (PFL, %) as an additional indicator for evaluating and monitoring hydrogen safety and leakage.

• 한국콘텐츠학회논문지
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• 제9권8호
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• pp.138-146
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• 2009

최근 대형의료기관을 중심으로 응급상황 내 환자를 보다 안전하게 진료하기 위해 Sense and Respond 기반의 의료정보 이벤트 모니터링 시스템에 대한 관심이 높아지고 있다. 본 논문에서는 이벤트와 모니터링 프로세스를 바탕으로 Sense and Respond 기반의 의료정보 이벤트 모니터링 시스템을 구축하였다. 시스템은 이벤트 정의, 이벤트 추출, 이벤트 전달 및 모니터링으로 구성되어, 보고자하는 의료정보를 실시간으로 파악 전달함으로써 실시간 대응이 가능하며, 실시간 정보 Tracking을 통해 병원 운영에 필요한 정보를 균형 있게 파악할 수 있다. 또한 이 벤트 전달을 통해 사안별 조기 대응으로 환자의 Safety 확보가 가능하며 병원의 업무상 다양한 문제점을 조기에 파악함으로써 업무의 효율성을 극대화 할 수 있다.

• 방사성폐기물학회지
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• 제6권4호
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• pp.369-385
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• 2008

부지감시 및 조사의 목적은 운영 전, 운영중 및 폐쇄 후 단계에서 변화가 예상되는 주요 부지특성을 지속적으로 감시함으로써 방사성폐기물처분장의 성능평가 및 설계에 필요한 기초자료를 제공하는 것이다. 부지감시의 단계별 주요내용은 다음과 같다. 운영전 단계에는 부지의 적합성 평가 및 처분장 건설과 운영에 필요한 주요 부지특성을 감시하며, 운영 중 단계에는 안전하고 효율적인 운영과 환경에 미치는 영향을 판단하기 위하여 주변지역을 포함하여 주요 부지특성을 감시한다. 폐쇄 후 단계에는 처분장의 방사성 물질로 인한 영향을 사전에 예방하고, 처분장의 장기적 안전성을 위하여 필요한 주요 부지특성 항목을 감시한다.

• 전자통신동향분석
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• 제38권6호
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• pp.31-40
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• 2023

Given recent accidents involving autonomous vehicles, driver monitoring technology related to the transition of control in autonomous vehicles is gaining prominence. Driver status monitoring systems recognize the driver's level of alertness and identify possible impairments in the driving ability owing to conditions including drowsiness and distraction. In autonomous vehicles, predictive factors for the transition to manual driving should also be included. During traditional human driving, monitoring the driver's status is relatively straightforward owing to the consistency of crucial cues, such as the driver's location, head orientation, gaze direction, and hand placement. However, monitoring becomes more challenging during autonomous driving because of the absence of direct manual control and the driver's engagement in other activities, which may obscure the accurate assessment of the driver's readiness to intervene. Hence, safety-ensuring technology must be balanced with user experience in autonomous driving. We explore relevant global and domestic regulations, the new car assessment program, and related standards to extract requirements for driver status monitoring. This kind of monitoring can both enhance the autonomous driving performance and contribute to the overall safety of autonomous vehicles on the road.