• 해양환경안전학회지
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• 제5권1호
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• pp.1-8
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• 1999

During the last 10 years, the various type of high speed craft have been greatly developed, and since around of 1990 the large size of high speed passenger and/or cargo vessels are also introduced and took into the service in the various routes over the world. In a marine traffic way some bridge need to build across a rivers, cannals or a waterways. This one will be an obstruction and potential risk of collision in the way of high speed craft. Accordingly some of collision accident have been reported, which were caused by a lost control, wind and hydrodynamic forces, fog or human errors. In this paper a high speed craft having 40 m length is assumed to be collided with a circular type of bridge piers at right angle. The mode of deformation, penetration depth of collapse, impact forces, reduction of speed, loss of kinetic energy, and influence of scantlings, etc. have been calculated in each speed with a time variation to find a maximum values within a limit, and are graphically presented.

• 기술사
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• 제41권6호
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• pp.38-44
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• 2008

Dr. Corley had various experiences as an outstanding structural engineer. His experience as the chief investigator for the collapse of World Trade Center and Oklahoma city building was so much useful to the lecture. His presentation had covered 3 different collapsed buildings like Oklahoma city, Pentagon and World Trade Center. He had shown to the audiences 2 videos and 76 slides by power point. The learned lessons from his presentation were: 1. The appropriate Building Code is very important. 2. The sound details are very important for the structure to resist the extreme outer force. 3. The continuous diagnosis and maintenance of the structure is important. 4. The reasonable attitude of the government against the accident is important. 5. The professional engineer must take a main role as a guard for the safety of the people.

• 대한안전경영과학회지
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• 제18권3호
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• pp.71-80
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• 2016

This study is on safety improvement measures through analysis of accident cases during plant storage tank construction. Storage tank is a general term for artificial ground facility constructed to store oil, water, gas, and other chemicals. Some companies have clustered storage tanks (tank farm). The construction methods vary according to the component and types of fluids. Because most of the construction procedures include lifting heavy weight materials using heavy construction equipment and are carried out at high places, storage tank construction contains more risk factors than normal aerial construction. Recently, major accidents such as storage tank collapse have occurred often, and cost many lives due to the characteristics of the structure. In this study we would like to analyze the cause of these accidents and propose measures to improve safety.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.999-1008
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• 2023

Deformed fuel rods can cause a partial blockage of the flow area in a subchannel. Such flow blockage will influence the core coolant flow and further the core heat transfer during the reflooding phase and subsequent severe accidents. Nevertheless, most of the system analysis codes simulate the accident process based on the assumed flow blockage ratio, resulting in inconsistencies between simulated results and actual conditions. This paper aims to study the influence of flow blockage in severe accident scenario of the CAP1400 reactor. First, the flow blockage model of ISAA code is improved based on the FRTMB module. Then, the ISAA-FRTMB coupling system is adopted to model and calculate the QUENCH-LOCA-0 experiment. The correctness and validity of the flow blockage model are verified by comparing the peak cladding temperature. Finally, the DVI Line-SBLOCA accident is induced to analyze the influence of flow blockage on subsequent CAP1400 reactor core heat transfer and core degradation. From the results of the DVI Line-SBLOCA accident analysis, it can be concluded that the blockage ratio is in the range of 40%-60%, and the position of severe blockage is the same as that of cladding rupture. The blockage reduces the circulation area of the core coolant, which in turn impacts the heat exchange between the core and the coolant, leading to the early failure and collapse of some core assemblies and accelerating the core degradation process.

• 대한원격탐사학회지
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• 제39권5_2호
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• pp.849-858
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• 2023

지진, 산사태와 같은 재난사고현장에서 조사업무는 시설물 붕괴 등 2차 재난 피해가 발생할 수 있어 많은 위험이 따른다. 이처럼 조사자가 직접 접근하기 힘든 재난현장에서 라이다(light detection and ranging, LiDAR)가 탑재된 드론 측량시스템을 통해 고정밀의 3차원 재난정보를 안전하게 취득할 수 있는 방법을 강구할 수 있다. 이에 본 연구에서는 2023년 4월 성남시 분당구의 정자교 붕괴사고 현장을 대상으로 드론 LiDAR의 재난 현장에서의 활용 가능성을 확인하였다. 이를 위해 사고 교량에 대한 고밀도 포인트 클라우드를 수집하고, 사고 교량을 3차원 지형정보로 복원하여 10점의 지상기준점 측량 성과와 비교하였다. 그 결과, 수평방향으로의 root mean square error (RMSE)는 0.032 m, 수직방향으로 0.055 m로 확인되었다. 또한, 지상 LiDAR를 통해 같은 대상지를 측량하여 생성한 포인트 클라우드와 비교한 결과, 수직방향으로 약 0.08 m가량의 오차가 발생하였지만 전체적인 형상은 큰 차이가 없을 뿐만 아니라 전체적인 데이터 취득과 자료 처리 시간 측면에서 드론 LiDAR가 지상 LiDAR보다 효율적임을 확인할 수 있었다. 따라서 많은 위험이 따르는 재난현장에서 드론 LiDAR의 활용을 통해 안전하고 신속한 현장 조사가 가능할 것으로 판단된다.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.179-187
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• 2021

전체 공사 기간의 약 25%를 차지하고 있는 거푸집 공사는 최근 5년간 사망자 수가 크게 줄어들지 않고 계속 발생하고 있으며 그중 붕괴사고가 가장 많은 비율을 차지하고 있다. 따라서 본 연구에서는 거푸집 붕괴사고에 관하여 위험도 및 안전관리 수준에 대한 설문조사를 통해 관리자와 작업자 간에 인식 차이를 비교 분석하고자 한다. 안전관리자, 현장작업자, 현장관리자 3개의 집단으로 구분하여 설문조사를 시행하였으며, 설문결과는 SPSS 프로그램을 활용한 독립표본 T-검정(Independent-Sample T-Test)을 시행하였다. 그 결과 관리자 간에는 인식의 차이가 거의 없는 반면, 관리자와 작업자 간에는 유의미한 인식 차이가 발생하였다. 더불어 관리도 측면에서 관리자와 작업자의 많은 인식 차이가 발생했으며 이 부분은 위험한 재해요인을 관리 및 감독하는 관리자와 직접 현장에서 작업을 진행하는 작업자 간의 입장차이를 극명하게 보여준다. 이러한 인식 차이가 재해를 줄이지 못하고 있는 요인이 될 수 있다고 사료된다. 따라서 이 연구를 바탕으로 좀 더 발전된 연구를 통하여 관리자와 근로자 간 인식의 차이를 줄여 재해에 관한 연구 시 기초자료로 활용될 수 있을 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2670-2677
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• 2023

In the nuclear safety studies, a new trend refers to the evaluation of uncertainties as a mandatory component of best-estimate safety analysis which is a modern and technically consistent approach being known as BEPU (Best Estimate Plus Uncertainty). The major objectives of this study consist in performing a study of uncertainties/sensitivities of the major analysis results for a generic CANDU 6 Nuclear Power Plant during Station Blackout (SBO) progression to understand and characterize the sources of uncertainties and their effects on the key figure-of-merits (FOMs) predictions in severe accidents (SA). The FOMs of interest are hydrogen mass generation and event timings such as the first fuel channel failure time, beginning of the core disassembly time, core collapse time and calandria vessel failure time. The outcomes of the study, will allow an improvement of capabilities and expertise to perform uncertainty and sensitivity analysis with severe accident codes for CANDU 6 Nuclear Power Plant.

• 한국안전학회지
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• 제33권2호
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• pp.14-20
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• 2018

In this study, we analyze the current status of major disasters in distribution works and propose safety measures through the distribution live-line work method and electric shock risk assessment. The result of analyzing the ratio of electric shocks to the occurrence of industrial accidents in the recent 13 years shows that the death rate is higher than other industries, especially the construction industry occupying most of the disaster, and it is higher than the collapse disaster. We analyze statistic data of 101 victims selected as core words of live work, distribution line, pole and 22.9 kV in the investigation report of major accident of electric shock fatal from 2001 to 2014. The safety measure was established through the risk assessment of the distribution method using the standard model of the risk assessment based on the results of electric shock analysis on the distribution line. In order to prevent the electric shock accident which is recently being discussed, the risk assessment procedure were carried out in the above-mentioned 22.9kV special high voltage live-line operation method. We derived the risk reduction plan for the distribution line from the results of the major accidents statistic and demonstration of the line works.

• 대한토목학회논문집
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• 제31권5D호
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• pp.727-737
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• 2011

본 연구에서는 효율적인 철도사고관리 및 복구작업을 위한 임시복구 시나리오를 개발하였다. 문헌조사 및 전문가 설문조사 결과를 통하여 임시복구 Worst Case 선정시기준이 되는 고려항목과 임시복구 시나리오 수립에 필요한 중요항목(event)을 도출하였으며, 임시복구가 가장 힘든 Worst Case로는 터널구간에서 발생하는 철도사고가 선정되었다. 이는 신속한 임시복구를 위해 좁은 공간에서 체계적이고 효율적인 복구절차를 갖추고 숙련된 복구요원 양성이 필요한 것으로 분석되었다. 또한, 본 연구에서는 통계학적 분석기법을 이용하여 임시복구 시나리오 수립 시 중요항목(event)간 중요도(우선순위)를 선정한 결과 임시복구유형중 시설물 붕괴를 가장 우선적으로 복구하고 선로매몰, 차량탈선 순으로 처리함이 복구시간을 단축할 수 있는 것으로 분석되었다. 이는 복구에 많은 시간이 소요되는 순으로 임시복구가 이루어져야 함을 나타낸다. 임시복구 시나리오는 임시복구 Worst Case, 임시복구유형별 중요항목(event)을 종합하여 표준운영절차(안) 11개를 제안하였다. 이를 활용하여 철도사고 DB관리 및 신속한 사고복구를 통해 정시성을 확보하여 열차지연시간을 최소화하는데 크게 기여할 것이다.

• 대한건축학회논문집:계획계
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• 제35권4호
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• pp.37-44
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• 2019

According to the statistical surveys and studies, insufficient maintenance in the use of existing buildings caused fire and collapse accidents. In this respect, I analyzed the data managed by the current building maintenance and inspection system to find out the actual state of safety management and proposed two significant results. First, regarding the state of the buildings, the safety management status of the small-sized ones, where 20 years or more passed after construction, is the worst and a priority improvement plan is required. Second, there are eight deeply concerning factors for the fire incidents and collapse accidents of buildings. In the order of high risk, these factors are structural strength (seismic design), exterior wall finishing material, basement floor, interior finishing materials, other evacuation facilities, corridors stairs entrances, rooftop, fire partition. We need to have more special designs and management plans regarding high-risk factors as a system to prevent accidents in the building.