• 한국가스학회지
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• 제5권1호
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• pp.52-59
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• 2001

LP가스 용접 용기의 가스 누출사고에 대한 통계적 분석을 통하여 사고 발생에 영향을 미치는 주된 요인을 조사하였다. 그 결과 대부분의 가스 누출은 용접부 국부부식에 따른 핀홀에 의한 누출이 가장 큰 비중을 차지하고 있다. 따라서, 본 논문에서는 2부구조 용기에서의 열처리조건의 문제점과 3부구조 용기의 T부위 터짐 현상에 의한 대책안을 제시하였다. 나아가, LP 가스 용기의 용접부 및 모재부에 대하여 산성비와 해수 분위기에서의 부식속도를 전기화학적 부식실험을 통하여 측정하였다. 또한, LP가스 용기의 제조공정중 분체도장 공정에 의한 도장막의 부착성 및 결함을 주사전자현미경을 통하여 분석하고 최적의 도장 두께를 제시하였다.

• 한국안전학회지
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• 제26권2호
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• pp.42-47
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• 2011

Going underwater is supposed to begin with the history of human beings. At first it was confined to relatively shallow level, less than several meters by holding breath. Recently, deep level diving has been necessary for such purpose as construction, maritime salvage, military operations, research and sports by using SCUBA(self-contained underwater breathing apparatus) equipment. As one goes down into water, the pressure on the diver is increased due to water pressure with depth, usually 1 atm for each 10 m water level. In deep water, mixed gas or nitrox(EAN, enriched air nitrox) could be applied for the divers lest they should get disease due to high pressure. Of these, the former is usually composed of oxygen and inert gas like helium or hydrogen, the latter contains higher oxygen content than that in normal air in which the oxygen concentration is designated by the character "EAN" followed by vol. % of oxygen, for example, "EAN 40" contains 40% of oxygen. In this case, a victim was found at the 39 m below the sea surface breathing air and nitrox in cylinder wrongly marked as EAN 36, which was analyzed to contain 63% of oxygen by GC/TCD. The cause of death could not be exactly related with the oxygen content in the nitrox cylinder, because the accurate depth for the victim to dive was not known, even though the victim was just found at the depth of 39 m. However, the wrongly marked nitrox could be believed to be the main cause of the death at the depth unless there happened any other accident except that during diving.

• 지역사회간호학회지
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• 제10권2호
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• pp.467-479
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• 1999

The mortality and morbidity caused by injury and poisoning has been major public health problem in Korea. This study was carried out to get information indispensable in developing prevention srategies peculiar to korean rural area. In this study 1.499 people of 496 households. who are living in five rural villages of Chooncheon City. Kang-Won Province. were interviewed in accordance with structured questionaire in 1996. The results obtained are summarized as follows: 1. The age-standardized annual incidence rates of injury and poisoning per 100 persons surveyed were 4.2 in males and 1.9 in females. The difference between sex was statistically significant. 2. The places where most of injuries and poisonings occurred were road 66.7% among males. road 31.6% among females. 3. The occurrence of the injuries and poisonings were clustered in intensive farming season in both males and females. 4. The laceration and stab wound were the most frequent nature of injuries in males and the fracture was the most frequent nature of injuries in females. The fracture. sprain were more frequent among males but sprain and contusion were more frequent among females. 5. Incidence rates of injuries and poisoning by cause were higher in traffic accidents among males. though falls among females. The cause specific incidence rate by age was high in traffic accident for 30-59 year age group. and for the aged people older than 60 years. 6. In the management pattern, 78.8% of the injuries and poisoning were received medical care in hospitals and clinics, and the duration of the treatment over 4 weeks in 37.0%. The results obtained indicate that organized community effort is urgently required to prevent injuries and poisonings in rural area.

• 설비공학논문집
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• 제29권12호
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• pp.654-662
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• 2017

When emergency core cooling system (ECCS) is operated during loss of coolant accident (LOCA) in a pressurized water reactor (PWR), pressurized thermal shock (PTS) phenomenon can occur as cooling water is injected into a cold leg, mixed with hot primary coolant, and then entrained into a reactor vessel. Insufficient flow mixing may cause temperature stratification and steam condensation. In addition, flow vibration may cause thermal stresses in surrounding structures. This will reduce the life of the reactor vessel. Due to the importance of PTS phenomenon, in this study, calculation was performed for Test 1 among six types of OECD/NEA ROSA tests with ANSYS CFX R.17. Predicted results were then compared to measured data. Additionally, because temperature difference between the hot coolant at the inlet of the cold leg and the cold cooling water at the inlet of the ECCS injection line is 200 K or more, buoyancy force due to density difference might have significant effect on thermal-hydraulic characteristics of flow. Therefore, in this study, the necessity to include buoyancy force term in governing equations for accurate prediction of single phase thermal stratification in both cold legs and downcomer by ECCS injection was numerically studied.

• 대한인간공학회지
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• 제27권1호
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• pp.45-51
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• 2008

The purpose of this survey was to identify ergonomic risk factors of work-related musculoskeletal disorders (MSD) and understand the current MSD risk status in the wholesale/retail industry. The field survey was conducted at 120 wholesale/retail establishments, and the cause of MSD occurred from the national industrial accident statistics by the Ministry of Labor in 2006 was analyzed in terms of company size, a term of work, job title, and cause of occurrence. The numbers of disasters on MSD were 602 which were included 432 disasters who met with low back pain by incident. A checklist was developed by KOSHA to use for the field survey. A total of 419 tasks were identified at the 120 establishments surveyed. The highest frequency was Task 2(45%) which was mostly observed in repetitive work (e.g. displaying, scanning, cutting or wrapping of goods). The second and third were Task 9(34%) and Task 8(14%) which were identified in manual materials handling (e.g. lifting, lowering, carrying or stocking of goods). The results suggest that the three Tasks should be first considered for the control in wholesale/retail industry and that exposure to MSD risk factors in those Tasks should be primarily addressed in order to reduce MSD risk in that industry.

• 한국안전학회지
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• 제31권5호
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• pp.187-194
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• 2016

A single fire event within a fire area can cause multiple initiating events considered in internal events probabilistic safety assessment (PSA). For an example, a fire event in turbine building fire area can cause a loss of the main feed-water and loss of off-site power initiating events. This fire initiating event could result in special plant responses beyond the scope of the internal events PSA model. One approach to address a fire initiating event is to develop a specific fire event tree. However, the development of a specific fire event tree is difficult since the number of fire event trees may be several hundreds or more. Thus, internal fire events PSA model has been generally constructed by modifications of the pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Recently, many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Up to now, there has been no analytical comparative study on the constructions of fire events PSA model using internal events PSA model with and without fault trees of initiating events. In this study, the changing process of internal events PSA model to fire events PSA model is analytically presented and discussed.

• Tribology and Lubricants
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• 제33권2호
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• pp.45-51
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• 2017

Engine oil is a substance used for the lubrication of internal combustion systems. However, in some case, defects in engine systems may contaminate engine oil with fuel. Contaminated engine oil can cause problems in the normal functioning of a vehicle. In this study, we investigate the functional properties of engine oil contaminated with diesel fuel. The test results indicate that the engine oil contaminated with diesel fuel has low flash point, pour point, density, kinematic viscosity and cold cranking simulator value. The contaminated engine oil which has low plash point can cause fire and explosion accident. Furthermore, a four ball test indicates that the contaminated engine oil increases wear scar to poor lubricity. Moreover, we investigate the GC pattern using SIMDIST (simulated distillation) for determination of diesel in engine oil. The SIMDIST analytic result, diesel was detected at earlier retention time than engine oil in chromatogram. Thus the SIMDIST method can define whether engine oil is contaminated by diesel fuel or not. We can use the SIMDIST method for the diagnosis of oil condition instead of analyzing other physical properties that require many analytic instruments, large volume of oil sample and long analysis time.

• Journal of Korean Neurosurgical Society
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• 제62권2호
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• pp.243-255
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• 2019

Objective : Although traumatic brain injury (TBI) occurs in people of all age groups, the elderly population is at a particular risk. The proportion of elderly population in the society is markedly increasing and Korea is one of the most rapidly aging societies. Here, we analyzed the data from 904 patients older over 65 years who were registered in the Korean Neuro-Trauma Data Bank System (KNTDBS). Methods : The Korean Society of Neurotraumatology recorded data from 20 institutions between September 2010 and March 2014. This retrospective study examined the clinical epidemiology, sex difference, outcome epidemiology, sociodemographic variables, and outcomes in the geriatric population related to TBI based on data from the KNTDBS. Results : The study included 540 men and 364 women. The age distributions in the male and female groups were statistically significantly different. The most common cause of trauma was a fall and diagnosis was acute subdural hematoma. The incidence was the highest in men aged 80-84 years and in women aged 75-79 years. The most common time of arrival to hospital after TBI was within 1 hour and 119 rescue team provided first aid earliest to patients with TBI. The mortality rate stratified according to the cause of trauma was significantly different, with mortality rates of 3.77% in fall and 11.65% in traffic accident. The mortality rates according the severity of brain injury, Glasgow Coma Scale score, and treatment were statistically significant. Conclusion : To our knowledge, this study is the first to focus on elderly patients with TBI in Korea and particularly investigate mortality and characteristics related to TBI-related death based on data from the KNTDBS. Although the study has some limitations, our results may be used to obtain useful information to study targeted prevention and more effective treatment options for older TBI patients and establish novel treatment guidelines and health polish for the geriatric population.

• 한국정보통신학회논문지
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• 제26권12호
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• pp.1794-1799
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• 2022

최근 증가하고 있는 도로 위 적재 불량 화물차는 비정상적인 무게 중심으로 인해 물체 낙하, 도로 파손, 연쇄 추돌 등 교통안전에 위해가 되고 한번 사고가 발생하면 큰 피해가 유발할 수 있다. 하지만 이러한 비정상적인 무게 중심은 적재 불량 차량 인식을 위한 주행 중 축중 시스템으로는 검출이 불가능하다는 한계점이 있다. 본 논문에서는 이러한 사회 문제를 야기하는 적재 불량 차량을 관리하기 위한 객체 인식 기반 AI 모델을 구축하고자 한다. 또한 AI-Hub에 공개된 약 40만 장의 데이터셋을 비교 분석하여 전처리를 통해 적재 불량 차량 검지 AI 모델의 성능을 향상시키는 방법을 제시한다. 또한 객체 추적을 통해 실시간 검지를 수행하는 방법을 제안한다. 이를 통해, 원시 데이터를 활용한 학습 성능 대비 약 23% 향상된 적재 불량 차량의 검출 성능을 나타냄을 보였다. 본 연구 결과를 통해 공개 빅데이터를 보다 효율적으로 활용하여, 객체 인식 기반 적재 불량 차량 탐지 모델 개발에 적용할 수 있을 것으로 기대된다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.729-732
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• 2008

건설공사의 규모와 설계 및 시공 방식이 다양하고, 규모가 확대됨에 따라 공사수행을 위한 초기 정보 획득 및 건설공사의 자동화의 실현을 위하여 RFID 기술을 적용할 수 있다. 건설 정보의 부족은 건설 자재 낭비, 작업률의 감소, 잘못된 정보로 인한 공정의 재수행, 건설 안전 사고등 전체 프로젝트의 비용적 시공성적 문제성을 야기한다. 이에 따라 본 연구는 IEEE 802.15.4a 혁신 무선 기술을 사용한 무선 공유 시스템과 RFID 시스템의 연계를 통한 향후 현장 시연 및 관련 문헌 조사, 현황 파악등을 통하여 RFID의 건설 현장 적용을 확인하고 건설 자동화를 위한 일환으로 자동화 건설 굴삭기 개발 등 건설 시공법 발전을 위하여 기여할 것이다. 이를 위해 RFID 시스템의 분석과 RTLS 와의 연동 방안을 제안하였다.