• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.293-295
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• 2005

산업현장에서 많이 사용되고 있는 전력기기의 이상 발생에는 여러 가지 원인이 있을 수 있다. 어떤 경우든 사고로 진전되면 경제적, 인적 손실이 발생된다. 본 논문은 GIS 및 많은 전력기기에서 사용되고 있는 절연매체인 $SF_6$의 인가되는 전압의 종류에 따라 저온에서의 절연파괴 특성을 알아보기 위해 모의 GIS 장치에 교류 전압 및 부극성 직류 전압 등 전원의 종류를 달리 하면서 각각의 전원 종류에 대한 $SF_6$가스의 절연파괴 전압을 측정하였다. 본 연구 결과는 SF6가스를 절연매체로 이용하는 전력기기를 혹한지역의 전력계통에서 사용할 때 전원의 종류에 따른 절연설계에 중요한 자료가 될 것으로 사료된다.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.698-707
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• 2016

An emergency manual is designed to minimize the extent and effect of lives and assets; it is not designed to prevent an accident. There have been continuous arguments in terms of manual effectiveness regardless of the fact that much effort and great cost have been invested in emergency planning and operations. The problems are that there are a number of different emergency manuals, that these manuals are hard to understand and rarely used due to their complexity, that they provide little direction toward the taking of action, and that coordination is difficult between those involved; all of these problems are related to two different pieces of legislations that define emergency manuals in different ways in terms of the contents required. The study has tried to respond to these arguments by exploring relevant legislation to identify emergency manuals that can be used to respond to rail incidents/accidents, for which previous responses have seemed inefficient. Further, some parts of the emergency manual contents are found to overlap, including the ways of differentiating incident responses, personnel roles and responsibilities by types of accident, and threat levels, all of which has resulted in unnecessary pages of the manuals. In preparing and operating such manuals, this study recommends that one piece of legislation that directly affects rail undertakings must be applied in an effort to increase effectiveness.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.376-386
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• 2019

The purpose of this study was to explore the learning progression of logical thinking in acid and base chemical reactions and to evaluate its validity. For this purpose, we collected 387 participants in 9 schools of elementary, middle and high schools nationwide. The questionnaire developed in this study was composed of nine items. The questionnaire presented the acid and base reactants and products, and the students pictured their thoughts on how these substances change, and answered the reasons of their thoughts. Situation contexts of the questionnaire were divided into two groups: one kind of solute dissolved in a solvent, and two kinds of solute dissolved in a solvent. In this study, six levels of learning progression were assumed by combining material conservation logic, combination logic, proportion logic, and particle number conservation logic. By analyzing the data, Infit and Outfit values of Person reliability, Item reliability, MNSQ and ZSTD were obtained from the Rasch model. As a result of the analysis of data, it was found that lower levels of learning progression prevailed up to the younger grade students till $8^{th}$ grade. The higher levels of learning progression(Level 2~Level 5) prevailed up to the older grade students. However, higher levels of learning progression dropped sharply in Grade 12. The 5 level of learning progression was very low in all grades, and $9^{th}$ grade had highest percentage of students belonging to the 5 level. Interpretation of these unusual results suggests a future research related to explanation differences of textbooks.

• The KIPS Transactions:PartD
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• v.8D no.2
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• pp.125-131
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• 2001

Various kind of disasters happens in our society. Most of them require immediate treatment to save life or to protect valuable products. When an accident happens in a place, it is reported to the headquarter of emergency measures system. According to the nature of accident several treatments orders are transmitted to the related authorities. In this paper, we introduce an intelligent emergency measures system that uses trigger mechanism of active databases. The system responds to various events spontaneously without intervention of mankind by triggering proper rules. The most important part of an action in the system is the capability of searching places to apply adequate treatments quickly. We have developed a new method for range queries and nearest neighbor queries which utilize the z-ordering technique to get fast responses. Those new methods are further extended to handle more realistic actual distance of road among positions.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.9-13
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• 2006

In the marine accidents judgment, investigation of truth of matters is one of important process to find out the reason of ship collision accidents. In this paper, reproduce system of ship collision accidents using ship manoeuvirng simulator technique will be introduced with which marine accidents can be easily reproduced in visual display at the case of marine accidents trial. In this system if the users select the type of ship and location of accidents, the process of ship collision will be provided in 2D and 3D display. The system also provides environmental visualizationdisplay such as fog whether and day-night view including various view angle that can be helpful to find out the reason of accidents.

• Korean Journal of Construction Engineering and Management
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• v.22 no.5
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• pp.48-54
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• 2021

According to the Ministry of Employment and Labor's statistics on occupational fatalities in South Korea, more than half of the fatalities in the past five years have occurred in the construction industry. The stuck-by and caught-in-between accidents associated with construction equipment is the major source of fatalities from construction sites. In order to prevent such accidents in construction sites, the government has spent lots of efforts including proposing the "special law on construction safety" and encouraging the implementation of new technology for accident prevention. However, numerous accidents are still occurred at construction sites and further efforts are still required. In this manner, this study developed a collision prevention technique that can prevent collision between equipment and worker by recognizing location and type of the nearby objects through ultrasound scanning. The study conducted a pilot experiment and the analysis results demonstrate the feasibility of achieving high performance in both object recognition and location estimation. The developed technique will contribute to prevent collision accidents at construction sites and provide the supplemental knowledge on developing automated collision prevention system for construction equipment.

• Proceedings of the Safety Management and Science Conference
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• 2012.11a
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• pp.385-392
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• 2012

본 연구는 미용업 분야를 헤어, 네일, 피부, 메이크업으로 나누어 사고재해 실태와 사용 제품에 대한 안전 인식도를 비교하기 위하여 수행되었다. 그 결과 근무하는 사업장의 작업 시 발생하는 유해요인으로는 분진, 근골격계, 화학물질 함유 제품의 유기용제 순으로 높게 나타났으며, 지난 1년 동안의 사고 및 재해는 26.3%가 경험한 것으로 파악되었다. 사고나 재해의 종류로는 베임, 인대 늘어남, 하지정맥류 등의 근골격계 이상이 가장 많았다. 미용업에서 사용되고 있는 제품의 화학물질 함유에 대한 인지도는 77.2%, 중금속 함유에 대하여 인지도는 59.1%로 나타났으며, 미용업 관련 제품의 표시사항(성분, 주의사항 등)에 대한 확인 여부는 '중요한 내용만 확인'한다는 응답이 가장 많았다. 화학물질에 대한 물질안전보건자료(MSDS)의 인지여부는 88.8%가 알지 못하는 것으로 나타났으며, 물질안전보건자료(MSDS)에 대한 인식도 및 사업장의 비치 여부가 낮은 것으로 파악되었다. 안전교육의 필요성은 73.6%로 높게 나타나 안전 교육에 대한 대책 마련이 요구되었다. 본 연구는 미용업 전반에 대한 사고재해 실태 및 안전의식에 관한 포괄적인 연구가 수행되어 미용업 근로자의 안전의식 고취와 정책적 안전관리 방안, 근로자 건강관리의 기초 자료로 활용되기를 기대한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.577-585
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• 2010

Traffic accidents are caused by several factors such as drivers, vehicles, and road environment. It is necessary to investigate and analyze them in advance to prevent similar and repetitive traffic accidents. Especially, the human factor is most significant element and traffic accidents by drinking-driving caused from human factor have become social problem to be paid attention to. The study analyzes traffic accidents resulting from drinking-driving and the effects of driver's attributes and environmental factors on them. The study is composed as two parts. First, the log-linear model is applied to analyze that accidents by drinking or non-drinking driving associate with road geometry, weather condition and personal characteristics. Probability is tested for drinking-driving accidents relative to non-drinking drive accidents. The study analyzes probability differences between genders, between ages, and between kinds of vehicles through odds multipliers. Second, traffic accidents related to drinking are classified into property damage, minor injury, heavy injury, and death according to their severity. Heavy injury is more serious than minor one and death is more serious than heavy injury. The ordinal regression models are established to find effecting factors on traffic accident severity.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.870-876
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• 1998

원자로용기의 안전성은 가동중 운전조건과 조사취화등으로 인한 재료의 열화(degradation)를 검토함으로써 평가되는데, 특히 운전조건중, 비상사태에 해당하는 가압열충격에 관한 평가가 최근 중요한 안전문제로 부각되고 있다 본 연구의 목적은 가압열충격 사고중 소규모 냉각재 손실사고(Small LOCA)가 발생하는 경우, 원자로용기 내벽에 존재하는 균열의 안전성을 유한요소해석을 통해 평가하는 것이다. 본 연구에서는 Small LOCA 발생시 원자로용기의 내벽에 존재하는 균열의 종류, 방향, 균열형상비 및 클래드부의 두께가 응력확대 계수 계산에 미치는 영향을 평가하였으며, 이를 위해 총 14가지 경우에 대해서 3차원 유한요소해석을 수행하였다. 이러한 Small LOCA 해석수행을 기초로 다양한 가압열충격 사고에 대한 유한요소해석 모델링 기법, 해석 기법, 후처리 기법을 제시하였다.

• Journal of the KSME
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• v.19 no.3
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• pp.190-196
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• 1979

본 강좌에서는 강도와 밀접한 관계를 가지고 있는 파양문제에 대하여, 특히 파괴된 파단면을 중심으로 기초적인 일반사항을 기술해 보고져한다. 그 내용으로는 파괴와 Fractograph, 전자현 미경과 Peplica 법, Shadowing의 유효성, 파괴의 종류와 Fractograph의 일열 및 파단면형성에 관한 기구등이다. 물체가 파괴된다고 하는 것은 외력을 가하면 물체가 2개로 나누어진다는 단 순한 현상이라고 생각되기 쉽지만, 실제로는 물체가 왜, 이렇게 파괴되는가에 대해서는 알 수 없는 것이 대단히 많다. 고체가 2개로 분리되는 macro 현상은 원자배열이나 응집력등과 같은 micro적인 것에 기인하는 복잡한 것들이 있다. 이미 여러분들이 아는 바와같이, 구조물이나 기 계의 파괴는 돌이킬 수 없는 사고에 이르기 쉽다. 작은 부품 1개의 파괴라던지, 강판의 흠이 원 인이 되어 항공기나 선박등의 사고가 생기는 경우가 있다. 금후에는 원자로나 핵융합반응장치 등이 인류의 에너지원으로서 많이 이용될 가능성이 있지만, 파괴사고가 허용되어서는 안된다. 과학기술의 진보와 더불어, 기계 및 구조물에는 보다 가한 재료가 요구되고, 개발되어가고 있다. 따라서 충분히 안전하게 설계되어 있다고 생각할 수 있는 구조라 하더라도 재료내부의 결함을 기점으로 하여 가끔 파괴가 일어남은 부인하지 못할 사실이다.