• 시스템엔지니어링학술지
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• 제19권2호
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• pp.46-58
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• 2023

Deterministic safety analysis is a crucial part of safety assessment, particularly when it comes to demonstrating the safety of nuclear power plant designs. The traditional approach to deterministic safety analysis models is to model the nuclear core using point kinetics. However, this simplified approach does not fully reflect the real core behavior with proper moderator and fuel reactivity feedbacks during the transient. The use of Multi-Physics approach allows more precise simulation reflecting the inherent three-dimensionality (3D) of the problem by representing the detailed 3D core, with instantaneous updates of feedback mechanisms due to changes of important reactivity parameters like fuel temperature coefficient (FTC) and moderator temperature coefficient (MTC). This paper addresses a CEA ejection accident at hot full power (HFP), in which the underlying strong and un-symmetric feedback between thermal-hydraulics and reactor kinetics exist. For this purpose, a multi-physics analysis tool has been selected with the nodal kinetics code, 3DKIN, implicitly coupled to the thermal-hydraulic code, RELAP5, for real-time communication and data exchange. This coupled approach enables high fidelity three-dimensional simulation and is therefore especially relevant to reactivity initiated accident (RIA) scenarios and power distribution anomalies with strong feedback mechanisms and/or un-symmetrical characteristics as in the CEA ejection accident. The Systems Engineering approach is employed to provide guidance in developing the work in a systematic and efficient fashion.

• 한국항행학회논문지
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• 제18권4호
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• pp.334-340
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• 2014

최근 항공 안전의 발전에도 불구하고, 항공기 사고의 뚜렷한 감소 추세 없이 유지되고 있다. 따라서 국제적인 항공안전관리의 방향은 기존의 항공안전 방식을 탈피하여 자료에 근거하여 분석된 요소들을 통하여 사고예방을 위한 위험요소를 제거하는 것에 관심을 가지고 있다. 본 논문은 전 세계적으로 항공안전 데이터의 보고와 교환을 위한 표준이 되고 있는 ECCAIRS를 소개한다. 또한 최근 10년간의 국내 항공사고 데이터를 활용하여 항공기 분류별(고정익과 회전익)로 항공기 사고와 준사고의 분포, 연도별 및 월별 사고 분포, 비행 단계 분포, 그리고 분류체계 분포 등에 대한 경향을 분석한다. 본 논문의 항공기 사고와 준사고의 추세 분석은 향후 추구해야 할 정량적인 안전관리의 유용한 방향이 될 것이다.

• 한국대기환경학회지
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• 제24권1호
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• pp.1-15
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• 2008

Chemical Accident Response Information System (CARIS) which has been designed for the efficient emergency response of chemical accidents produces the real-time atmospheric fields through the Regional Atmospheric Modeling System, RAMS. The previous studies were emphasized that improving an initial input data had more effective results in developing prediction ability of atmospheric model. In a continuous effort to improve an initial input data, we replaced the land-use dataset using in the RAMS, which is a high resolution USGS digital data constructed in April, 1993, with the latest land-use data of the Korea Ministry of Environment over the South Korea and simulated atmospheric fields for developing a real-time prediction in dispersion of chemicals. The results showed that the new land-use data was written in a standard RAMS format and shown the modified surface characteristics and the landscape heterogeneity resulting from land-use change. In the results of sensitivity experiment we got the improved atmospheric fields and assured that it will give more reliable real-time atmospheric fields to all users of CARIS for the dispersion forecast in associated with hazardous chemical releases as well as general air pollutants.

• 한국식품영양학회지
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• 제30권6호
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• pp.1299-1309
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• 2017

The aim of this study was to investigate status of safety accidents of school foodservice cooks in Daegu and to analyze the factors affecting the occurrence of the accidents in order to seek effective ways for preventing safety accidents in school foodservice. The survey showed that the most frequent safety accidents were 'bruises', followed by 'burns', 'contact with harmful substances such as disinfectants', 'fall-off ' and 'sprains'. The mental fatigue perception of the respondents was generally lower than the physical fatigue perception. The means of the perception levels of work intensity, cooking environment of the foodservice place, and safety-related behaviors, and consciousness were 3.15, 2.99, and 4.06 out of 5 points, respectively. In addition, the annual average of the number of participating in the accident prevention training per person was 17.34 times, that is, the respondents received the training at least once a month on average. A multiple regression analysis was conducted to investigate the variables affecting the occurrence of safety accidents that happened to foodservice cooks. It revealed that the work intensity perception and the cooking environment perception influenced the frequency of safety accidents.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3665-3671
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• 2013

본 연구는 중학생의 안전실천과 인지실패의 정도를 알아보고, 이 들이 안전사고에 미치는 영향을 알아보기 위한 것이다. 연구대상자는 총 292명이며 2012년 11월 5일부터 11월 25일까지 설문조사하여 자료를 수집하였다. 연구도구는 SPSS win17.0을 사용하였고, 평균과 표준편차, Paired t-test, 피어슨 상관계수를 이용하였다. 대상자의 안전실천과 인지실패는 부(-)의 상관을 나타냈으며 안전에 대한 실천정도가 높은 대상자가 사고인지 실패율이 낮았다. 또한 안전사고 경험이 적게 나타났다. 그와 반대로 안전에 대한 인지실패가 높은 대상자는 안전사고 경험이 높게 나타났다. 따라서 안전실천과 인지실패의 정도를 지속적으로 파악하여 안전사고 예방에 대한 방안을 마련하기 위한 연구가 필요하다. 또한 연구의 범위를 확대함으로써 학교현장에 다양한 안전사고 예방 교육프로그램을 적용하여 안전의식 함양과 안전실천의 일반화가 이루어져야 한다.

• 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.

• 한국환경보건학회지
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• 제37권3호
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• pp.226-233
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• 2011

Exactly 25 years after the Chernobyl nuclear disaster, 11th of March 2011 the Fukushima nuclear accident occurred in Japan and was ranked at level 7 same to the Chernobyl. A Korean and Japanese joint civil survey was conducted around Fukushima on April 13-17. The radiation survey data clearly shows a large hotspot area between 20 km and 50 km radius north and west direction from the accident reactors, with the highest radiation recorded being 55.64 ${\mu}Sv/hr$ in the air, 99.89 ${\mu}Sv/hr$ in the surface air, and 36.16 ${\mu}Sv/hr$ in a car, respectively. 3.65 ${\mu}Sv/hr$ in the air and 6.89 ${\mu}Sv/hr$ in the surface air were detected at the playground of an elementary school in Fukushima City. Spring came with full cherry blossoms in Fukushima, but it was silent spring of radiation contamination. Interviews with Fukushima nuclear refugees reveal serious problems about Japanese nuclear safety systems, such as there was no practical evacuation drill within 1-10 km and no plan at all for 10-30 km areas. Several reforms items for Korean nuclear safety system can be suggested: minimization of accident damage, clear separation of regulatory and safety bureaus with a new and independent administrating agency, community participation and agreement regarding the safety system and levels, which is the major concern of 80% Korean. To tackle threats of nuclear disaster in neighboring nations like China, a new position entitled 'Ambassador for nuclear safety diplomacy' is highly necessary. The nuclear safety of Korea should no longer be the monopoly of those nuclear engineers and limited technocrats criticized as a 'nuclear mafia'.

• Safety and Health at Work
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• 제8권3호
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• pp.306-314
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• 2017

Background: In order to obtain a deeper understanding of an incident, it needs to be investigated to "peel back the layers" and examine both immediate and underlying failures that contributed to the event itself. One of the key elements of an effective accident investigation is recording the scene for future reference. In recent years, however, there have been major advances in survey technology, which have provided the ability to capture scenes in three dimension to an unprecedented level of detail, using laser scanners. Methods: A case study involving a fatal incident was surveyed using three-dimensional laser scanning, and subsequently recreated through virtual and physical models. The created models were then utilized in both accident investigation and legal process, to explore the technologies used in this setting. Results: Benefits include explanation of the event and environment, incident reconstruction, preservation of evidence, reducing the need for site visits, and testing of theories. Drawbacks include limited technology within courtrooms, confusion caused by models, cost, and personal interpretation and acceptance in the data. Conclusion: Laser scanning surveys can be of considerable use in jury trials, for example, in case the location supports the use of a high-definition survey, or an object has to be altered after the accident and it has a specific influence on the case and needs to be recorded. However, consideration has to be made in its application and to ensure a fair trial, with emphasis being placed on the facts of the case and personal interpretation controlled.

• 한국항행학회논문지
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• 제16권4호
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• pp.687-696
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• 2012

최근 항공 안전의 발전에도 불구하고, 항공기 사고의 뚜렷한 감소 추세 없이 유지되고 있다. 따라서 국제적인 항공안전관리의 방향은 기존의 항공안전 방식을 탈피하여 자료에 근거하여 분석된 요소들을 통하여 사고예방을 위한 위험요소를 제거하는 것에 관심을 가지고 있다. 본 연구는 이러한 위험요소를 발굴하고 분석하기 위하여 EU에서 개발하고 2010년부터 한국에서 도입하기 시작한 ECCAIRS에 대한 개관을 소개하였다. 아울러 ECCAIRS에 입력된 국내 항공사고 Data를 활용하여 항공기 사고와 준사고의 분포, 연도별 및 월별 사고 분포, 비행 단계 분포, 그리고 분류체계 분포 등에 대한 경향을 분석하였다. 본 연구의 항공기 사고와 준사고의 추세 분석은 향후 추구해야 할 정량적인 안전관리의 유용한 방향이 될 것이다.

• 대한안전경영과학회지
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• 제16권2호
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• pp.1-9
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• 2014

This study tried to propose plan to prevent human error of railroad driver among human error of railroad worker which takes great share in railroad accident. For this, in order to maintain correlation between the accident actually occurred after the opening of high-speed railroad and experience of accident that did not happened, survey on respondent was analyzed by conducting survey on KTX captain who is working in driving work of high-speed railroad, and instruction management team manager who manages KTX captain and captain. This thesis classified the factors by human factor, job factor, environment factor, organization factor, and established human error management model by comparing and analyzing how each factors have spatial interrelations with a railroad accident. The purpose of this study is to contribute to make safe railroad, and reliable railroad by preventing human error accident by minimizing human error of high-speed railroad drivers, and improving driving workers to cope accurately and fast with irregularities through various institutional improvement, improvement of driving facilities, improvement of operating room environment, and improvement of education system.