• Korean Journal of Construction Engineering and Management
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• v.22 no.5
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• pp.73-85
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• 2021

This study proposes an efficient management direction for Korean construction accident cases through a deep learning-based text data classification model. A deep learning model was developed, which categorizes five categories of construction accidents: fall, electric shock, flying object, collapse, and narrowness, which are representative accident types of KOSHA. After initial model tests, the classification accuracy of fall disasters was relatively high, while other types were classified as fall disasters. Through these results, it was analyzed that 1) specific accident-causing behavior, 2) similar sentence structure, and 3) complex accidents corresponding to multiple types affect the results. Two accuracy improvement experiments were then conducted: 1) reclassification, 2) elimination. As a result, the classification performance improved with 185.7% when eliminating complex accidents. Through this, the multicollinearity of complex accidents, including the contents of multiple accident types, was resolved. In conclusion, this study suggests the necessity to independently manage complex accidents while preparing a system to describe the situation of future accidents in detail.

• TTA Journal
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• s.175
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• pp.84-85
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• 2018

최근 싱크홀이 사건사고 뉴스의 단골손님으로 등장하고 있다. 갑자기 도로 무너져내려 길 가던 차 앞바퀴가 빠지는가 하면, 예고 없이 발밑이 푹 꺼지며 사람이 빨려 들어가듯 추락한다. 고층 건물이 통째로 삼켜지기도 한다. 눈에 보이지 않는 공간에서 갑작스레 만들어지는 싱크홀은 그야말로 공포의 대상이다.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.66-73
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• 2019

Thanks to various efforts to reduce disasters by the government and the Health and Safety Authority, disasters across industries and the construction industry show their reduction trend. However, the falling disasters in the construction industry have not decreased and increased on the contrary. Especially falling disaster caused by Hanging Scaffolding is the most critical disaster which shows low occurrence frequency but is directly connected to death of worker. The working environment for Hanging Scaffolding is poor in domestic construction site. In particular, the Hanging Scaffolding workers in small construction sites are not on the safety control and management by anyone for their works. They are driven to unsafe working condition with mostly uncertified facilities which are made by themselves. Therefore, this study is focused on searching falling disaster factors from the 242 disaster cases caused by Hanging Scaffolding Work in 15 years presented by KOSHA, and trying to provide suggestions for improvement. The improvement of the method of work requires facility improvement and work due to high accident rate caused by unsafe behavior. Analysis of the case of a disaster occurring over the past 15 years shows that no disaster occurred due to problems in the order of operations presented by KOSHA. However, it was found that many accidents resulted from death caused by safety belts not being installed or attached to ropes using safety belts without following the order of work. The most important aspect of improving the work method was the installation and wearing of lifeboats and safety belts.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.265-266
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• 2016

본 연구에서는 수집된 자료에서 화물차 교통사고를 분류하고 계절과 기상상태, 도로유형, 법규위반, 사고유형 측면에서 각각의 변수들이 사고 심각도에 미치는 영향을 파악함으로써 유의하게 화물차 교통사고 심각도를 높이는 요인을 분석하고자 하였다. 화물차 사고는 가을의 경우 사고 심각도의 오즈비가 1.23배로 증가하고, 안개가 꼈을 경우 사고 심각도는 16.49배 증가하는 것으로 나타났다. 법규위반, 도로형태, 사고유형 등 여러 요인에 의한 사고 위험도가 증가했지만 특히 도로 외 이탈로 인한 추락사고에서 사고 위험도가 크게 나타났으며 전도전복으로 인한 사고 위험도도 큰 것으로 나타났다.

• Journal of the KSME
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• v.28 no.4
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• pp.366-376
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• 1988

피로에 있어서 해결되지 않은 문제는 현재도 허다하여 많은 연구가 필요하나, 현재까지의 지식 으로도 크나 큰 피로파괴사고는 충분히 방지할 수 있다고 저자는 생각하고 있다. 본고의 파손 해소예로부터도 어느 정도 추측이 가능하듯이 현재의 파괴사고의 대부분은 인위적인 것이다. 인위적인 파괴사고를 방지하는 방법의 하나는 합리적인 설계 및 보수, 관리시스템을 확립하는 것일 것이다. 당해기술이 현재도 미흡한 국내에서는 그 필요성이 더욱 절실히 느껴져, 본고에서 소개한 건전성 평가절차도 그러한 맥락에서 이루어지고 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1727-1732
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• 2010

Forensic engineering is the area of expertise of people qualified to serve as engineering experts in courts of law or during arbitration proceedings. An aerial-lifter can lift and carry load, including people, using power. Recently, failure of aerial-lifter internal parts while working and sweeping causing injuries and damage to property almost always generates conflict between the automaker and customer. Hence, the investigation of such events generally involves an engineering analysis. One of the possible reasons for accidents, such as a vehicle catching fire is the failure of oil pressure machine and the supporting pin. The results of formal inspections and engineering tests can reveal the cause for the failure of the mechanical parts. Therefore, the failure mechanism is analyzed by adopting fractography methods and by applying an instrumented indentation technique to compare the material properties of the reference part with those of the malfunctioning part.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.415-425
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• 2017

Stresses occur in the spent nuclear fuel disposal canister due to the impulsive forces incurred in the accidental drop and impact event from the transportation vehicle onto the ground during deposition in the repository. In this paper, the comparative study of finite element analysis for stresses occurring in various models of the spent nuclear fuel disposal canister due to these impulsive forces is presented as one of design processes for the structural integrity of the canister. The main content of the study is about the design of the structurally safe canister through this comparative study. The impulsive forces applied to the canister subjected to the accidental drop and impact event from the transportation vehicle onto the ground in the repository are obtained using the commercial rigid body dynamic analysis computer code, RecurDyn. Stresses and deformations occurring due to these impulsive forces are obtained using the commercial finite element analysis computer code, NISA. The study for the structurally safe canister is carried out thru comparing and reviewing these values. The study results show that stresses become larger as the wall encompassing the spent nuclear fuel bundles inside the canister becomes thicker or as the diameter of the canister becomes larger. However, the impulsive force applied to the canister also becomes larger as the canister diameter becomes larger. Nonetheless, the deformation value per unit impulsive force decreases as the canister diameter increases. Therefore, conclusively the canister is structurally safe as the diameter increases.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.2
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• pp.75-86
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• 2019

The biggest obstacle in the nuclear power generation is the high level radioactive waste such as the spent nuclear fuel. High level radioactivities and generated heat make the safe treatment of the spent nuclear fuel very difficult. Nowadays, the only treatment method is a deep geological disposal technology. This paper treats the structural safe design problem of the spent nuclear fuel disposal canister which is one of the core technologies of the deep geological disposal technology. Especially, this paper executed the nonlinear structural analysis for the stresses and deformations occurring in the canister due to the impulsive force applied to the spent nuclear fuel disposal canister in the case of an accidental drop and ground impact event from the transportation vehicle in the repository. The main content of the analysis is about that the impulsive force is obtained using the commercial rigid body dynamic analysis computer code, RecurDyn, and the stress and deformation caused by this impulsive force are obtained using the commercial finite element static structural analysis computer code, NISA. The analysis results show that large stresses and deformations may occur in the canister, especially in the rid or the bottom of the canister, due to the impulsive force occurring during the collision impact period.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.113-121
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• 2019

The death rate of industrial accidents per 10,000 people in Korea is two to three times higher than that of major countries. Falling accidents at the construction site happened to have caused the most deaths. Analysis of existing research and measures by national institutions showed that the industrial accident management concentrated on falling accidents was insufficient and the seasonal safety management measures were not enough. There is thus the need for research that provides detailed and enough information on falling accidents. This study, therefore, aims to overcome the limitations of existing research and safety management accident response using a methodology that provides the necessary information for the prevention of fall accidents by deriving seasonal crash characteristics of the construction site. In order to provide enough information, 387 cases of seasonal construction site falling were collected, which describes the causal relationship of accidents. Text mining using principal component analysis and cluster analysis was carried out. The analysis showed that: In the spring, snowfall and unreasonable operation of equipment including lifts were the major cause. In summer, most accidents were caused by form, insufficient safety inspection, and installation work. In autumn, weather factors such as wind and typhoon were the cause. In winter, material transportation, exterior wall work, and ignore safety precautions were the cause of the crash.

• Annual Conference of KIPS
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• 2022.11a
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• pp.191-193
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• 2022

유모차 사고는 추락/넘어짐/미끄러움으로 인해 발생하는 사고가 가장 큰 비율을 차지한다. 또한 보행이 불편한 고령자가 유모차 또는 보행기를 보조기구로 사용할 때에도 유모차와 유사한 사고 발생 확률이 높다. 기존의 유모차, 전동 휠체어, 보행기 등 출시 제품들은 넘어짐과 관련된 사고예방 기능은 구현되지 않았으므로 사고를 예방하기 힘들다. 이를 해결하기 위해 본 연구는 기울기에 따라 보행 중 안전을 보조하고, 속도에 따른 넘어짐 관련 사고를 예측하여 보호자 및 주변 사람들에게 위험을 알리는 사고예방을 위한 보행보조시스템을 설계하고 구현하였다. 이 시스템을 통해 유아 및 고령자가 이용하는 보행보조기를 더욱 안전하게 사용하여 2차 사고를 예방할 수 있는 효과를 기대할 수 있다.