• Title/Summary/Keyword: 붕괴 사고

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CFD-based Fire Accident Impact Analysis in Clean Room for semiconductor PR Process (반도체 PR 공정의 클린룸내 CFD 기반 화재 사고 영향 분석)

  • Chun, Kwang-Su;Yi, Jinseok;Park, Myeongnam
    • Journal of the Korean Institute of Gas
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    • v.25 no.6
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    • pp.35-44
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    • 2021
  • The PR (Photo Resist) process in the semiconductor process is a process that uses a mixture of flammable substances. Due to the process equipment is installed in a clean room and when flammable substances leak, there is a high risk of suffocation, fire, and explosion. It is necessary to analyze the impact of accidents that may occur during operation and to evaluate whether the safety of workers can be guaranteed. In this study, the value of radiant heat and temperature change at the monitor point set up virtual inside the clean room was confirmed through CFD simulation of 10 leak and fire scenarios using the FLACS CFD - Fire Module. A fire that occurs inside a clean room transfers high radiant heat to the inter-story structure, but its scope is quite limited, and it is unlikely that it will collapse in a single fire accident. There was no scenario in which two stairs leading to the exit were exposed to high radiant heat at the same time due to a fire accident, therefore workers were able to escape in case of a fire. In addition, it was confirmed that the level of radiant heat and temperature rise rapidly decreased as they moved downstairs. According to the API 520 standard, workers exposed to 6.31 kW/m2 of radiant heat that workers can withstand for 30 seconds were confirmed that it was possible to sufficiently escape from the inside.

Construction and Utilization Plan of Steep Slope and Underground Spatial Information DB for Steep Slope Disaster Prevention (급경사지방재를 위한 급경사지정보 및 지하공간정보 DB 구축과 활용 방안 연구)

  • Lee, Kyungchul;Jang, Yonggu;Song, Jihye;Kang, Injoon
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.7
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    • pp.13-21
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    • 2014
  • Recently, a great number of natural disasters have more frequently happened than the past. The National Emergency Management Agency of Korea has made preparation for the integrated management system of steep slope lands. There is information based on the steep slope inspection sheets and the underground spatial information related to the prevention against steep slope disasters. Nevertheless, building a complete DB System to prevent the hazards and secure the safeties should be urgently dealt with. It is mainly because the information of the National Disaster Management System is restricted to the text-based brief data. Therefore, the purpose of this study is to suggest the method as to building steep slope DB system for disaster prevention and maximizing the availabilities. This study shows the way of building a web-based DB system having its root in the steep slope inspection sheets. The method of establishing the ideal DB system that has liaisons between the Ministry of Land, Infrastructure and Transport and the National Emergency Management Agency is discussed in this study. Furthermore the optimization of DB utilization will assist the various integrated steep slope management systems based on U-IT which are ongoing projects.

Problems of Family Education in an Industrialized Society and Alternatives(The case of Modern Korean Society) (산업사회(産業社會)에 있어서 가정교육상(家庭敎育上)의 문제(問題)와 그 대책방안(對策方案) (현대(現代) 한국사회(韓國社會)를 중심(中心)으로))

  • Lee, Kyung-June
    • Journal of Fisheries and Marine Sciences Education
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    • v.6 no.2
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    • pp.183-189
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    • 1994
  • 1970년 이후 우리나라는 산업화로 인하여 사회구조와 가정구조가 크게 변화 되었다. 도시집중화로 인한 각종 공해 발생, 교통난, 인구이동의 문제를 비롯하여 그리고 핵가족화로 인한 가부장적 권위상실 및 가정교육부재, 청소년 비행등 수 많은 문제가 야기되었다. 특히 핵가족화로 발생된 심각한 사회문제는 전통윤리의 붕괴와 가정교육의 부재현상을 발생 시켰다. 이와같은 문제발생에 관한 선행연구를 종합해보면 첫째, 핵가족화로 인해 발생한 가족규모의 축소현상으로 자녀들의 다면적 인격형성에 결손을 초래하여 성장후 독립심과 의지가 약하고 고집이 세며 이기적이고 자기중심적인 성향이 되어 사회생활에 부적응 현상을 초래하게 되었다고 한다. 그 이유는 다면적 인간관계의 결여로 상호 협조하고 사랑을 교환한 경험 부족과 외동자녀에 대한 부모의 관심이 자녀의 욕구에만 집중되어 자녀종속적인 태도가 크게 적용하였기 때문이다. 둘째는 산업화 사회에서의 부부동시 사회참여가 자녀양육에 어머니와의 애착형성이 결여되어 모성실조를 겪게 된 문제를 들 수 있다. 어머니와 자녀간의 애착형성이 결여 됨으로 발생되는 문제는 지적 정체현상과 정서발달의 장애가 주 원인이 되어 감정 통제력이 약해서 공격적 행동이나 반 사회적 행동으로 확대되어 청소년문제 발생의 원이 되고 있음을 시사하고있다. 세째로 산업화사회와 경쟁력 조장을 들 수 있다. 산업사회를 개방사회, 경재력사회 혹은 능력사회라하여 고학력위주의 선발형태가 입시경쟁을 부추기고 있으며 그에 따라 많은 청소년들과 학부모들이 상위 지향적인 심리가 작용하여 자녀들의 입시경쟁에만 집중하게 되었다. 이러한 원인으로 인하여 인간교육 즉 가정교육을 외면하여 반도덕적, 반사회적 문제를 야기하게 하였다. 특히 전통적 가정윤리가 붕괴되어 부모에 대한 효관의 약화, 부부간의 애정약화 및 물질지향적인 사고가 이혼률을 증가시켜 가정붕괴를 가져왔다. 이상에서 논의된 자녀교육의 부재가 자녀들의 지적 정서적 문제로 확대되어 산업화사회의 모순점을 노출시키고 있음을 알 수 있다. 이와같은 문제를 해결하기 위한 대안으로 연구자가 제시하는 방안은 훌륭한 가정교육을 위해서 우선되어야 하는것은 부모자신의 인격적 개인완성을 제안하였다. 인격의 완성은 양심과 행동이 일체하는 사람을 지칭한다. 다음은 서로 위하여 사는 삶을 영위하는 인격체가 되어 양심의 법에 따르는 삶, 타인을 위하여 사는 삶을 자녀들에게 보여줌으로서 반두라의 모델링 교육을 제안하였다. 마지막으로 오늘날과 같은 암기위주의 경쟁교육이 아니라 타고난 잠재성 개발에 주력하는 교육으로, 적성과 소질을 개발하는 창조적 산 교육장을 마련하여 주고 또한 그것을 뒷바침하는 가정윤리교육의 회복이 무엇보다도 이 시대가 절실히 요구하는 바람직한 교육이라 하겠다.

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Study on 3-D Simulation for Overriding Evaluation of Urban Train (도시철도차량 타고오름 평가를 위한 3 차원 충돌시뮬레이션 기법 연구)

  • Jin, Sung Zu;Jung, Hyun Seung;Kwon, Tae Soo;Kim, Jin Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.10
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    • pp.1063-1068
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    • 2015
  • In this paper, we propose a collision simulation technique the evaluation of urban trains. We perform simulation that include a dynamics bogie model which represents the dynamic behavior of bogies and a finite-element model that can model crash behavior. We perform simulation in accordance with the 40-mm vertical offset head-on scenario for overriding the evaluation of the EU and domestic crashworthiness regulations. We evaluate the overriding by the vertical displacement of the wheelset using the overriding evaluation standard. Finally, if proposed simulation technique is applied, we can evaluate the overriding for urban-train crashworthiness regulations.

Research on the Establishment of Contractor Centered Safety Management System to Reduce Construction Disaster (건설재해 저감을 위한 발주자 중심의 안전관리체계 구축에 관한 연구)

  • Kia, Seongho;Park, Namkwun
    • Journal of the Society of Disaster Information
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    • v.10 no.4
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    • pp.503-510
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    • 2014
  • Large scale construction disasters such as recent Noryangjin flooding incident and Banghwadaegyo collapse accident are occurring persistently. Thereupon, the role and responsibility of the various construction participants are considered as major element to reduce disaster at the construction site. Construction industry is a process of building construction object by going through planning, designing, constructing, and maintenance controlling in which various bodies of act, from contractor to designer and builders, participate. However, the subject of current safety supervision is focused on the builder, the contract enterprise which directly employs workers, while the safety activity participation of the contractor, who exerts decision-making authority at the highest level, is excluded. Therefore, this study understands the level of awareness and reality on the safety activity of each construction participants from which the improvement plan on the contractor centered safety management system is proposed.

A Study on the Improvement of Engineering and Construction Supervision Guarantee System in Korea (국내 설계.감리 등 용역보증제도 현황 및 개선방안 연구)

  • Lee, Yong-Hee;Choi, Jae-Ho
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.3
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    • pp.53-61
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    • 2011
  • After several collapse accidents of large structures in the early 1990s in Korea, the government enacted a law that architectural, engineering and construction firms are obliged to have insurance for projects over a certain size. Particularly, with regard to insurance in design and construction supervision works (i.e. engineering insurance), although several operation-based problems were pointed out from practitioners, still little research has been done on analyzing current regnlartory and operational state and suggesting policy alternatives. Hence, this study applies Delphi technique to solicit current operational problems and propose a series of improvements on engineering insurance based on interview surveys targeting major market participants: municipalities, engineering firms, and insurance companies. Key findings culminate in adopting guarantee limits based on credit evaluation, abrogating joint surety, covering a loss of life, increasing insurance entrance fee, extending time covered, and etc. Reaching a consensus on the proposed alternatives between the market participants will form the foundation for sound developments of construction design and engineering industry.

Transient Stability Enhancement of Power System by Using Energy Storage System (에너지저장시스템을 이용한 전력계통의 과도안정도 향상)

  • Seo, Gyu-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.26-31
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    • 2017
  • The conventional method of improving the transient stability in a power system is the use of reactive power compensation devices, such as the STATCOM and SVC. However, this traditional method cannot prevent the rapid voltage collapse brought about by the stalling of the motor due to a system fault. On the other hand, the ESS (Energy Storage System) provides fast-acting, flexible reactive and active power control. The fast-acting power compensation provided by an energy storage system plays a significant role in enhancing the transient stability after a major fault in the power system. In this paper, a method of enhancing the transient stability using an energy storage system is proposed for power systems including a dynamic load, such as a large motor. The effectiveness of the energy storage system compared to conventional devices in enhancing the transient stability of the power system is presented. The results of the simulations show that the simultaneous injection of active and reactive power can enhance the transient stability more effectively.

Damage Prediction of Infomation and Communication Facilities for Prolonged Power Outage (장기간 정전사태에 대비한 기반시설-정보통신시설-에서의 피해예측)

  • Song, Chang Young;Cho, In Uh
    • Journal of Korean Society of Disaster and Security
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    • v.5 no.2
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    • pp.81-87
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    • 2012
  • Critical infrastructures (energy, information technology and communications, banking, transportation, public government services, etc.) are now more vital to modern society. Citizens, businesses and governments all rely on an array of interlinked physical and information infrastructures to satisfy their needs and perform their daily operations. At the same time, these infrastructures are becoming increasingly interdependent, such that failure of one of them can often propagate and result in domino effects. Recent dramatic episodes, from 9/11 to the Madrid train bombings, the April 2010 ash cloud the power cuts in Korea in 2011, and the cyber-attacks have highlighted the need for a comprehensive, internationally coordinated policy for the protection of critical infrastructures. For the purposes of this report, we define critical infrastructure as infrastructure whose failure would result in substantial damage to society and/or the economy.

Study on Obstacle Deflector of a Railway Vehicle Using Tension-type Energy Absorbers (인장형 에너지흡수부재를 이용한 철도차량용 장애물제거기 연구)

  • Kim, Hongeik;Kim, Jinsung;Kwon, Taesoo;Jung, Hyunseung
    • Journal of the Korean Society for Railway
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    • v.20 no.2
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    • pp.173-181
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    • 2017
  • The obstacle deflector sweeps obstacles off the track or absorbs crash energy with an energy absorber to prevent derailment of a train and to minimize damage and casualties after an accident. In this study, an obstacle deflector and its operational mechanism were designed with a tension-type energy absorber and a 4-bar linkage system. Also, a test method was suggested and verified with FEA (Finite Element Analysis) and UTM (Universal Test Machine) for testing of the static load and energy absorbing ability according to EN 15227 regulations. Through this study, an obstacle deflector that meets the EN 15227 standard was designed and a test method was suggested to adjust the collapse load easily and to verify it experimentally according to the design and verification procedure of the obstacle deflector.

A Study on the Individual Recognition with Skull Image Composition (두개골 영상합성에 의한 개인감정시스템 연구-II)

  • 송현교;이양원;강민구
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.1
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    • pp.3-10
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    • 1998
  • In this paper, a new superimposition scheme using a computer vision system was proposed with 7 pairs of skull and ante-mortem photographs, which were already identified through other tests and DNA fingerprints at the Korea National Institute of Scientific Investigation. At this computer vision system, an unidentified skull was caught by video-camcoder with the MPEG and a ante-mortem photograph was scanned by scanner. These two images were processed and superimposed using pixel processing. Recognition of the individual identification by anatomical references was performed on the two superimposed images. This image processing techniques for the superimposition of skull and ante-morterm photographs simplify used the previous approach taking skull photographs and developing it to the same size as the ante-mortem Photographs. This system using various image Processing techniques on computer screen, a more precise and time-saving superimposition technique could be able to be applied in the area of computer individual identification.

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