• Title/Summary/Keyword: risk contour

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A Comparative Study on the Risk(Individual and Societal) Assessment for Surrounding Areas of Chemical Processes (화학공정 주변지역에 미치는 위험성(사회적 위험성 및 개인적 위험성) 평가방법에 관한 비교 연구)

  • 김윤화;엄성인;고재욱
    • Journal of the Korean Society of Safety
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    • v.10 no.1
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    • pp.56-63
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    • 1995
  • Two methods of the numerical method of CPQRA(Chemical Process Quantitative Risk Analysis) and the manual method of IAEA(International Atomic Energy Agency) were used to estimate the individual risk and societal risk around the chemical plant. Where, the CPQRA is introduced to verify the theoritical background of the manual of international atomic energy agency. The Gaussian plume model which has a weather stability class D with velocity of 5m/s was applied to calculate dispersion of hazard material. Also, 8-point method was employed to the effects of accidents for wind distribution. Furthermore, historical record, FTA(Fault Tree Analysis) and ETA(Event Tree Analysis) were used to estimate the probability or frequency of accidents. Eventually, the individual risk shows isorisk contour and the societal risk shows F-N curve around hazard facility, especially in chemical plants. Caulculated results, which both individual and societal risk, by using IAEA manual show simillar results to those of calculation by numerical method of CPQRA.

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Risk Assessment and Risk contour mapping (네덜란드의 위험성 평가 예 -위험성 평가 및 위험 등고선도-)

  • 편집실
    • Fire Science and Engineering
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    • v.8 no.1
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    • pp.47-52
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    • 1994
  • 이 논문은 설계상의 안전 및 완전한 정량적 위험성 평가에 의해 맞추는 것이 가능한 여러가지 방법(QRA: Quantitative risk analysis)에 촛점을 두면서, 위험성 평가의 방법론의 간략한 개요를 소개하고 있다. QRA의 결과는 단독 위험 및 그룹 혹은 사회적 위험으로써 보통 소개된다. 계산된 단독 risk는 자주 단독 위험 graph(IRG : Individual risk graph)와 단독 위험등고선(IRC : Individual risk contours)의 형으로 나타낸다. IRG와 IRC는 예를 들면 다음과 같은 사고의 시나리오로 계산된다. : 여러가지 기상조건 하에서 2kg/s의 암모니아의 유출을 1800s로 한다. 이 예는 그래프가 곡선의 상승을 나타내는 것이 확실하다. 마지막으로, QRA는 예를 들어서 토지이용계획 등에 유용한 수단으로 될 수 있다고 할 수 있다. 한편 화학플랜트의 안전에 대해서는, 위험성 평가를 위해 다른 방법이 유효하며, 불가피하다.

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A Study on Risk Assessment and Risk Mitigation Measures of Liquefied Chlorine Leak (액화염소 누출의 위험도 분석 및 위험경감조치에 대한 연구)

  • Lee, Ju-Youn;Chon, Young-Woo;Hwang, Yong-Woo;Lee, Ik-Mo
    • Journal of the Korea Safety Management & Science
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    • v.20 no.1
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    • pp.1-9
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    • 2018
  • As the chemical industry becomes more advanced, the awareness of chemical accidents is rising, and legal systems for chemical safety management are strengthened. In this study, quantitative risk assessment of liquid chlorine leak was conducted. Risk assessment was performed in the order of frequency analysis, consequence analysis, and risk calculation. The individual risk was presented in the form of contour lines. The social risk was expressed by the FN curve. The risk of day and night was in an unacceptable area, so it was required to mitigate risk. Therefore in-building, which could trap the pool, was selected as a risk mitigation measure. As a result of the cost benefit analysis, it was concluded that this measure should be reasonably implemented.

A Study on Total Hazard Level Algorithm Development for Hazardous Chemical Substances (유해화학물질의 종합위해등급 알고리즘 개발에 관한 연구)

  • 고재선;김광일;정상태
    • Fire Science and Engineering
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    • v.14 no.4
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    • pp.7-16
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    • 2000
  • In the study, three criteria(toxicity, fire & explosion, environment) and damage prediction method for each case was set up, and all these criteria were applied to the subject substance that was selected as hazardous level by integrating all criteria through Algorithm. Particularly, the environment criterion is a comprehensive concept, environment index modeling by combining USCG(United State Coast Guard) & MSDS(Material Safety Data Sheet) environment criteria classifications and the environment part of MFPA's health hazardousnes(Nh). And for damage prediction method of each criterion were adopted and they were applied to hazardous chemical substances in use or stored by chemical substance related enterprises located in each region that made possible to set up total hazard level of used substances(inflammability, poisonousness and counteraction on a unit substance, and hazard level & display modeling on environment) & damage prediction in case of accident & solidity setup(CPQRA: Chemical Process Quantitative Risk Assessment, IAEA: International Atomic Energy Agency, VZ eq: Vulnerable Zone) risk counter. Thus it is deemed that it can be applied to toxic substance leakage that can happen during any chemical processing & storage, application as a tool for prior safety evaluation through potential dangerousness computation of fire & explosion.

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Influence of Ground Conditions on Seismic Risk (부지(敷地)의 지질조건(地質條件)과 지진위험도(地震危險度)와의 관계(關係))

  • Yang, Sung Jin;Jun, Myung Soon
    • Economic and Environmental Geology
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    • v.14 no.3
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    • pp.143-153
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    • 1981
  • Seismic risk maps in Korea are made using Korean historical and modern earthquake data. The risk maps made by several method are presented in contour line of vibratory ground motion(acceleration, velocity, and displacement). The method used are Kawasumi (1951), Kanai (1968), and Hsich et al (1975) method. The maps made by Kawasumi (1951) method represent the acceleration distribution ground and those by Kanai (1968) method show the acceleration, velocity, and displacement at bed rocks, The risk analysis by the method of Hsich et al (1975) shows the probability of acceleration at each of soft, medium and hard grounds in each tectonic province in Korea.

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Comparison of Recurrence Rates with Contour-Loop Excision of the Transformation Zone (C-LETZ) and Large Loop Excision of the Transformation Zone (LLETZ) for CIN

  • Boonlikit, Sathone;Srichongchai, Hemwadee
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6005-6008
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    • 2014
  • Aim: To compare recurrence rates of large loop excision of the transformation zone (LLETZ) with those of contour-loop excision of the transformation zone (C-LETZ) in the management of cervical intraepithelial neoplasia (CIN). Materials and Methods: The medical records of 177 patients treated consecutively by LLETZ and C-LETZ for CIN at Rajavithi Hospital between 2006 and 2009 were retrospectively reviewed. Results: Of the 87 women in the C-LETZ group, 2 cases (2.30%) had recurrence compared with 13 cases (14.4%) of the 90 women in the LLETZ group, the higher recurrence rate in the latter being statistically significant (p<0.05). Median times of follow up in the C-LETZ and LLETZ groups were 12 months and 14 months respectively (p>0.05). The C-LETZ group showed less intraoperative bleeding compared to the LLETZ group, but the rate of achievement of single specimens and positive margins were similar in the two groups. Conclusions: The present study demonstrated the superiority of C-LETZ over LLETZ in terms of efficacy; C-LLETZ is associated with a lower recurrence rate and also carries a smaller risk of intraoperative bleeding than LLETZ. The rotating technique still has a potential role in treating precancerous lesions of the cervix.

Risk Value Calculation Method for Moderate Risk Concentration Type at Qualitative Risk Analysis Phase (정성적 위험분석 단계에서 중간위험 집중형 위험도 산정 방법)

  • Kim, Seon-Gyoo
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.2
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    • pp.38-45
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    • 2015
  • The risk analysis phase of construction risk management process is subdivided into the qualitative risk analysis that plays a major role, and the quantitative risk analysis acting as a supportive role. The traditional calculation method for quantifying a risk value that has been applied so far is an equation to multiply a probability by an impact simply, but its result shows the low risk value biased distribution. Although another equation that shows the high risk biased distribution as an alternative of traditional method was proposed, both of the low or high risk biased equations do not match with the statistical general knowledge that most natural phenomenons are close to the normal distribution. This study proposes a new risk value calculation method that is concentrated to the moderate risk value. Because the risk value distribution by a new method shows a normal shape similar to natural phenomenon, it helps to choose a middle level not biased to the low or high levels when choosing the level of risk response. Furthermore, it could contribute to improve the flexibility and rationality of risk analysis method by providing additional options for the risk value calculation.

HNS 선박의 객체지향 항로 설계에 관한 연구

  • Jeong, Min-Gi;Yun, Jong-Hwi;Lee, Mun-Jin;Gang, Won-Su;Lee, Eun-Bang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.05a
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    • pp.2-2
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    • 2018
  • 선박 항로 설정 시 안전성, 효율성, 편리성 확보 측면에서 항해자들의 경험 기반 주관적인 의사결정에 여전히 의존하였다. 본 연구에서는 HNS(Hazardous and Noxious Substance) 운송 선박의 항해 중 조우하는 고정 위험(Hazard)으로 인해 발생하는 해상교통 사고의 위험성(Risk)를 기반으로 등위험도 곡선(Risk Contour)을 표시하고, 목적별 객체 지향 설정 방법을 제안하였다. 제안된 방법을 실험 해역에서 검증하고, 실제항로와 비교, 평가하였다. 여러 조건과 항로에서 반복적 검증과 실시간 정보 송 수신이 가능해지면, 항해사의 최적항로 설정방법이나 자율운항선박에도 활용이 기대된다.

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Pedicled Anterolateral Thigh Flaps for Reconstruction of Recurrent Trochanteric Pressure Ulcer

  • Bahk, Sujin;Rhee, Seung Chul;Cho, Sang Hun;Eo, Su Rak
    • Archives of Reconstructive Microsurgery
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    • v.24 no.1
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    • pp.32-36
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    • 2015
  • The reconstruction of recurrent pressure sores is challenging due to a limited set of treatment options and a high risk of flap loss. Successful treatment requires scrupulous surgical planning and a multidisciplinary approach. Although the tensor fascia lata flap is regarded as the standard treatment of choice-it provides sufficient tissue bulk for a deep trochanteric sore defect-plastic surgeons must always consider the potential of recurrence and accordingly save the second-best tissues. With the various applications of anterolateral thigh (ALT) flaps in the reconstructive field, we report two cases wherein an alternative technique was applied, whereby pedicled ALT fasciocutaneous island flaps were used to cover recurrent trochanteric pressure sores. The postoperative course was uneventful without any complications. The flap provided a sound aesthetic result without causing a dog-ear formation or damaging the lower-leg contour. This flap was used as an alternative to myocutaneous flaps, as it can cover a large trochanteric defect, recurrence is minimized, and the local musculature and lower-leg contour are preserved.

Research on the Prevention of Major Industrial Accident By Integrated Risk Management System (중대산업사고 예방을 위한 종합위험관리체제(IRMS) 구축에 관한 연구)

  • Kwon, Hyuck-Myun;Seong, Dae-Hyun;Kim, Jae-Hyun;Yim, Dae-Sik;Kim, Gi-Young;Pyeon, Mu-Wook;Moon, Il;Ko, Jae-Wook;Lee, Young-Soon;Yoon, En-Sup
    • Journal of the Korean Society of Safety
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    • v.18 no.3
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    • pp.88-93
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    • 2003
  • The Process Safety Management (PSM) by the Law of Industry, Safety and Health has been performed for preventing major accidents of chemical plants since 1996. In terms of preventing chemical accidents more precisely, it is essential to develop a tool for quantitative risk assessment. For this, KOSHA (Korea Occupational Safety and Health Agency) developed an Integrated Risk Management System (IRMS). The system is designed to assimilate data on chemical plant hazards from external database, to integrate these data with location information(topographic and demographic), and to make them user-friendly accessible. The system consists of several main functions: display of five major Korean petrochemical complex layout display of equipment layout with its information utilizing the external database, zonation of the hazard effected area with consequence analyses, the most probable accident scenario generation, accident/incident database and calculation of frequency of accident using equipment reliability database, etc. The highlight of IRMS is to provide the risk contours using GIS(Geographical Information System) technology. IRMS is intended to manage hazardous installation more systematically and effectively, to reduce the number of accident remarkably, further minimizing production loss in the plant. The system is now under application to about 500 PSM sites as well as and emergency authorities in Korea by KOSHA (Korea Occupational Safety and Health Agency)