• Nuclear Engineering and Technology
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• 제54권1호
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• pp.162-176
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• 2022

In Lead-based reactor (LBR) severe accident, the meltdown and migration inside the reactor core will lead to fuel fragment concentration, which may further cause re-criticality and even core disintegration. Accurately predicting the migration and solidification behavior of melt in LBR severe accidents is of prime importance for safety analysis of LBR. In this study, the Moving Particle Semi-implicit (MPS) method is validated and used to simulate the migration and solidification behavior. Two main surface tension models are validated and compared. Meanwhile, the MPS method is validated by the L-plate solidification test. Based on the improved MPS method, the migration and solidification behavior of melt in LBR severe accident was studied furthermore. In the Pb-Bi coolant, the melt flows upward due to density difference. The migration and solidification behavior are greatly affected by the surface tension and viscous resistance varying with enthalpy. The whole movement process can be divided into three stages depending on the change in velocity. The heat transfer of core melt is determined jointly by two heat transfer modes: flow heat transfer and solid conductivity. Generally, the research results indicate that the MPS method has unique advantage in studying the migration and solidification behavior in LBR severe accident.

• 대한안전경영과학회지
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• 제16권4호
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• pp.31-40
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• 2014

While Korea had achieved radical growth of construction industry, it also had accumulated problems in material, human and economical loss due to its low quality of safety level. Therefore, not only enterprises but also the nation is putting in a great deal of efforts for construction safety. However, its effect is not satisfiable. This research aims for change of construction cite by introduction of professional Safety Patrol Management System(SPMS) and consideration of its necessity. To consideration of its necessity, we compared and anaylzed average numbers of indicated dangers and safety accident incidences in each construction cites and we researched changes in worker's safety sense. It will establish the suitable design standards and suggest the basic database for estimating disaster and accident ratio.

• 대한안전경영과학회지
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• 제14권3호
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• pp.49-57
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• 2012

Proportion of falling from height accident at construction work accounts for more than 40%, and the number of injuries is getting increased. So without considering falling from height, we can say that it's hard to achieve our goal(accident prevention). Another critical point that we have to think about theses days is the fact that construction workers are getting older. To be specific, the number of workers who are above 50 years old accounts for 65.6% among the fatalities(2007~2011, KOSHA inspection). Accordingly, to effectively prevent construction accedents, especially falls from height, we need to focus on motion analysis of older construction workers and then make suitable measures for growing accident rates at construction work.

• 한국건축시공학회지
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• 제21권2호
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• pp.157-163
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• 2021

재해자수를 상시근로자수로 나눈 값이 재해율이다. 건설공사의 경우 공사실적과 노무비율을 기준으로 하여 상시근로자수를 추정하고 이를 이용하여 재해율을 산정하므로 재해율의 정확도가 낮아질 수 있다. 또한 현행 재해율 산정기준은 공사유형간의 특성을 반영하고 있지 않다. 본 연구는 공사종류별 특성을 고려한 재해율 보완방식을 제시하는 것으로 목적으로 진행하였으며, 지난 18년간의 공사실적 및 재해건수 통계자료를 바탕으로 상관분석과 선형회귀분석, 중회귀분석 등을 실시하여 공사유형과 재해유형간의 관계를 나타내는 회귀식을 도출하였다. 본 연구에서 제시한 수식은 기존의 건설공사 재해율의 단점을 보완하여 재해의 증감 및 예년대비 재해율의 높고낮음을 판단하는 보조지표로서의 활용이 가능할 것으로 기대된다.

• 한국안전학회지
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• 제24권1호
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• pp.69-77
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• 2009

This paper reports the aging driver traffic accident severity modeling results. For the modeling, Poisson regression approach is applied using the data set obtained from the Korea Transportation Safety Authority's simulator-based driver aptitude test results. The test items include the estimations of moving objects' speed and stopping distance, drivers' multi-task capability, and kinetic depth perception and so on. The resulting model with the response variable of equivalent property damage only(EPDO) indicated that EPDO is significantly influenced by moving objects' speed estimation and drivers' multi-task capabilities. More interestingly, a comparison with the younger driver model revealed that the degradation of such capabilities may result in severer crashes for older drivers as suggested by the higher estimated parameters for the older driver model.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2120-2134
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• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• 한국방재안전학회논문집
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• 제16권4호
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• pp.137-145
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• 2023

어린이보호구역 일명 스쿨존에서 어린이와 보행자 사망사고가 지속적으로 발생하고 있다. 2019부터 2021년까지 3년 동안 전국 스쿨존 내 어린이사망사고는 11건이나 발생했으며, 2022년 12월에도 서울특별시 강남구 초등학교 인근 스쿨존에서 초등학생 사망사고가 발생했고, 2023년 4월에도 대전광역시 서구 중학교 인근 스쿨존과 부산광역시 영도구 초등학교 인근 스쿨존에서 각각 초등학생이 사망하는 사고가 발생하는 등 최근까지도 어린이보호구역 내 보도에서 어린이 사망사고가 지속적으로 발생하고 있어, 스쿨존 내 설치된 안전시설 현황과 관련 규정에 대한 면밀한 검토가 필요한 시점이다. 국내 어린이보호구역 보도에 설치된 안전시설 현황과 관련 규정을 조사 ‧ 분석하고, 어린이보호구역 보도용 안전시설에 대한 제도개선 필요사항을 도출하였다.

• 한국안전학회지
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• 제30권5호
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• pp.20-28
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• 2015

Recently, railroad's preference greatly increased as the environment-friendly means of transportation as the importance in the aspects of environment and energy efficiency. So the government established the Korea Rail Network Authority which takes full charge of railroad construction in 20047 for regular railroad construction to combine major key points in the whole country with each other to be one city region by connecting them to each other to be within the commute time range of a hour and thirty minutes. And it has arranged large-scale railroad construction by establishing plans to build the 1st and 2nd national railroad networks as the national project and investing about 100 trillion won in it from 2006 to 2020. As large-scale railroad construction is promoted as the national project like this, there has been a string of safety accidents in it due to the large and complex construction project. As the government strengthened the safety accident prevention plans, safety accidents have tended to decrease in 2011. However, accidents of construction machinery have found to increase. Therefore, this study tried to investigate accident cases of the Korea Rail Network Authority for the recent 5 years and analyze accidents of construction machinery to prevent them in railroad construction sites and suggest accident prevention plans due to it by conducting, investigating, and analyzing the survey of its operators and superintendents of the construction sites and drawing the problems.

• 한국직업건강간호학회지
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• 제9권2호
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• pp.121-131
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• 2000

This study was conducted to acquire data in order to institute an effective industrial accident compensation insurance(IACI) system. The subjects were employers and employees in small scale industries which have less than 5 employees. The questionnaires consisted of questions on perception and need for IACI. A total of cases were 181 employers and 105 employees participated in the study. Perception and need of employers and employees were assessed using the ANOVA, t-test. The results were as follows ; 1. Workplaces examined mostly in manufacturing(78.9%), industries with one employee(44.1%). Beneficiary rate of IACI 4.4%. 2. 60.0% of employees had experienced an industrial accident and in most cases employers paid the cost of medical treatment. 45.0% of employers nd 50.0% of employees were not aware that IACI had been put into effect starting July, 1, 2000. 52.0% of employers had no type of industrial accident compensation. 3. The need of outcome measures, especially of employers and employees who had an IACE, were higher than those without an IACI. Employers and employees who had experienced an industrial accident outnumbered those who hadn't. The results of this study reveal that there is a great need for the institution of an IACI and health promotion policy in small scale industries.

• 한국보건간호학회지
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• 제17권1호
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• pp.96-112
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• 2003

The purpose of this study was to determine how often toddlers and preschoolers in kindergartens have accidents and what factors affect the accident rate. The study population consisted of 150 children who were attending at nursery schools and 150 children who were attending at kindergartens. The data was collected from ten nursery schools and five kindergartens from five districts in Daegu. The questionnaires were distributed to teachers of participating nursery schools and kindergartens to be completed using nursing care records in the institutions and by interviewing children's parents about all of the accidents happened in a previous year. Data were collected during the period of August 1 through 31, 2002. The results of the study are as follow: 1. Among 300 children, 282 had 506 accidental injuries during the study period. 2. The month, the day and the time with the highest accident rate were April. Monday, and between 2 and 4 o'clock in the afternoon, respectively. 3. Locations where the injury took place most included nursery schools or kindergartens, around the homes of the children, and inside the home. 4. Most accidents were occurred due to lack of carefulness of the children, and the most prevalent forms of injury was abrasions. 5. Most frequently injured part of the body was legs of the children. 6. Most injuries were healed within three days and required first aid measures to disinfect the wound. Mostly, these were performed by family members at home. Some children go to the hospital to suture the open wound. Most frequent type of complication was scar formation and the cost of the treatment ranged from 9,000 to 30,000 won. 7. Children's age. sex, birth order. personality. type of family composition. type of residency. father's occupation, father's age, and mother's age were significantly related to the frequency of injury among children. Children who were in nursery schools and kindergartens need their assessment for accident involving condition according to seasons, time. place. This study provided a very useful and important data to prepare accident prevention education program and accident prevention strategies, and to develop Injury Surveillance System.