• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.2
• /
• pp.74-81
• /
• 2017

An off-site consequence analysis is used to calculate the risks when hazardous chemicals that is being used on-site has been exposed off-site; the biggest factor that impacts the risk is the risks of accident scenarios. This study seeks to calculate risks according to accident scenarios by applying OGP/LOPA risk calculating methods for similar facilities, calculate risk reduction ratio by inspecting applicable IPL for incidents, and propose an appropriate risk standard for different risk calculating methods. Considering all applicable IPL when estimating the safety improvement of accident scenarios, the risk of OGP is 8.05E-04 and the risk of LOPA is 1.00E-04, According to the case of IPL, the risk is 1.34E-02. The optimal risk level for accident scenarios using LOPA was $10^{-2}$, but the appropriate risk criteria for accident scenarios in foreign similar studies were $10^{-3}{\sim}10^{-4}$, the risk of a scenario can be determined at an unacceptable level. When OGP is applied, it is analyzed as acceptable level, but in case of applying LOPA, all applicable IPL should be applied in order to satisfy the acceptable risk level. Compared to OGP, the risk is high when LOPA is applied. Therefore, the acceptable risk level should be set differently for each risk method.

• Journal of radiological science and technology
• /
• v.39 no.4
• /
• pp.577-585
• /
• 2016

The purpose of this study is to evaluate the accuracy of beam delivery QA software using the MLC dynalog file, about the VMAT plan with AAPM TG-119 protocol. The Clinac iX with a built-in 120 MLC was used to acquire the MLC dynalog file be imported in MobiusFx(MFX). To establish VMAT plan, Oncentra RTP system was used target and organ structures were contoured in Im'RT phantom. For evaluation of dose distribution was evaluated by using gamma index, and the point dose was evaluated by using the CC13 ion chamber in Im'RT phantom. For the evaluation of point dose, the mean of relative error between measured and calculated value was $1.41{\pm}0.92%$(Target) and $0.89{\pm}0.86%$(OAR), the confidence limit were 3.21(96.79%, Target) and 2.58(97.42%, OAR). For the evaluation of dose distribution, in case of $Delta^{4PT}$, the average percentage of passing rate were $99.78{\pm}0.2%$(3%/3 mm), $96.86{\pm}1.76%$(2%/2 mm). In case of MFX, the average percentage of passing rate were $99.90{\pm}0.14%$(3%/3 mm), $97.98{\pm}1.97%$(2%/2 mm), the confidence limits(CL) were in case of $Delta^{4PT}$ 0.62(99.38%, 3%/3 mm), 6.6(93.4%, 2%/2 mm), in case of MFX, 0.38(99.62%, 3%/3 mm), 5.88(94.12%, 2%/2 mm). In this study, we performed VMAT QA method using dynamic MLC log file compare to binary diode array chamber. All analyzed results were satisfied with acceptance criteria based on TG-119 protocol.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.1
• /
• pp.67-73
• /
• 2016

This study analyzed the state of the vessels which were using the berth for dangerous goods more than its carrying capacity in the major dangerous cargo handling port of Ulsan in Korea, The result of the analysis showed that a ship which has 3 times more than the maximum berthing capacity was moored at berth. Accordingly, a simulation model for 50,000 DWT berth was built and carried out the mooring safety analysis with 50,000 DWT, 70,000 DWT and 100,000 DWT vessels by mooring assessment program. The evaluation was carried out according to the standard environment presented in OCIMF standards. 50,000 DWT vessel was evaluated to meet the acceptable criteria but, 70,000 DWT and 100,000 DWT vessels exceeded the acceptable limit as per external conditions. Consequently, safe mooring guidelines were suggested and also proposed the building of common 'Mooring safety guideline' for port with assessment of different cases.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2013.06a
• /
• pp.474-476
• /
• 2013

위기허용수준(RAC)은 시스템의 안전성 평가를 위한 확률적인 기준으로, 소형 해상 부유체의 롤, 피치, 히브 등 세 가지 동적운동의 위험수준 평가에 적용할 수 있다. 부유체의 동적운동 값들은 모델을 통해서 획득한 후, 이에 관한 누적확률분포함수를 추론하여 상대적인 위기수준을 결정하게 된다. 이 연구는 모델에서 획득한 세가지 동적운동에 대한 최적의 누적확률분포함수 선정에 관한 것이 목적이다. Exponential, Extreme Value, Gamma, Lognormal, Normal, Poisson 등 6가지 대표적인 누적확률분포함수를 세가지 동적운동에 적용하여 평가한 결과, 롤과 히브 운동의 경우는 Beta 누적분포함수가 최적임을 나타냈고, 피치 운동의 경우는 Gamma 누적분포함수로 대표하는 것이 최적임을 나타냈다. 아울러 향후 본 연구 결과의 적용방법에 대해서도 검토하였다.

• Journal of Navigation and Port Research
• /
• v.35 no.1
• /
• pp.23-30
• /
• 2011

This study was carried out in order to verity the usefulness of FSA(Formal Safety Assessment) methods as a tool to conduct a safety assessment of general cargo ships flying the Korean flag, and to provide useful information on 'the Safety of General Cargo Ships' for IMO committee's discussion on the matter at a future session. In the previous paper, "A Study on High-level FSA for Korean-flagged General Cargo Ships(1)", the concepts of the FSA methodology and its five steps were described and the results of Hazard Identification(Step 1) and Risk Analysis(Step 2) from the FSA study for the Korean-flagged general cargo ships were discussed. Subsequent to the Steps 1 & 2, the identification of Risk Control Options(RCOs-Step 3) for eliminating or reducing either the frequency or the severity of the risks identified and their Cost-Benefit Assessment(CBA-Step 4) were undertaken. In this paper, the results of the Steps 3 & 4 are discussed, and some recommendations are made.

• Applied Chemistry for Engineering
• /
• v.31 no.3
• /
• pp.277-283
• /
• 2020

The smoke hazard assessment of building materials focusing on smoke performance index-II (SPI-II) and smoke growth index-II (SGI-II) was investigated. The test species used were Japanese cedar, spruce, lauan, and red pine. The smoke characteristics of wood specimen were investigated using a cone calorimeter (ISO 5660-1). SPI-II was measured after the combustion reaction increased by 1.31~2.15 times based on red pine. The fire risk by SPI-II increased in the order of spruce, lauan, Japanese ceda, and red pine. SGI-II increased by 1.18~2.55 times compared to that of Japnese ceda. The fire risk caused by SGI-II increased in the order of Japanese ceda, spruce, lauan, and red pine. CO_mean concentrations were ranged from 58 to 133 ppm, which was higher than permissible exposure limits of the occupational safety and health administration (OSHA), 50 ppm. Therefore, woods such as red pine containing various volatile organic substances, were considered to be highly smoke hazardous due to low SPI-II and high SGI-II.

• Journal of Food Hygiene and Safety
• /
• v.21 no.2
• /
• pp.52-59
• /
• 2006

This survey was conducted to monitor the current status of pesticide residues in imported agricultural products circulated in Gwangju, 2005. A total of 108 samples was analyzed by multiresidue method. Of these samples, 32 were citrus fruits, 60 were tropical fruits and grapes, and 16 were vagetables. The origin was Philippine for 39 samples, U.S.A. for 36, China for 12, New Zealand for 11, Chile for 6, etc. The overall rate of detections was 30.6% and no samples had violative residues. Of citrus fruits,20 samples (62.5%) had residues and the residues were thiabendazole, imazalil, chlorpyrifos, etc. Of tropical fruits and grapes, 13 samples (12.0%) had residues and the residues were azoxystrobin, chlorpyrifos, carbendazim, captan, etc. 16 of vagetables had no detectable pesticide residues. Thiabendazole (71% in oranges and 56% in grapefruits) and imazalil (50% in oranges) were found in citrus fruits, which were frequently used as post-harvest pesticides. And azoxystrobin which is one of strobilurin fungicides, was often detected in mango, tropical fruit(27%).

• Applied Chemistry for Engineering
• /
• v.32 no.4
• /
• pp.423-430
• /
• 2021

In order to evaluate the fire risk and fire risk rating of wood for construction materials, this study focused on fire performance index-III (FPI-III), fire growth index-III (FGI-III), and fire risk index-IV (FRI-IV) according to Chung's equations-III and -IV. Western red cedar, needle fir, ash, and maple were used as the specimens. The fire characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment on the specimen. The FPI-III measured after the combustion reaction was 0.86 to 12.77 based on polymethylmethacrylate (PMMA). The FGI-III was found to be 0.63 to 5.26 based on PMMA. The fire rating according to the FRI-IV, which is the fire rating index, was 0.05 to 6.12, and the western red cedar was 122.4 times higher than that of the maple. The fire risk rating according to the FRI-IV increased in the order of maple, ash, needle fir, PMMA and western red cedar. The CO peak concentration of all specimens was measured as 103 to 162 ppm, and it was 2.1 to 3.2 times higher than 50 ppm, the permissible exposure limits of the US occupational safety and health administration. Materials such as western red cedar, which have a low bulk density and contain a large amount of volatile organic substances, have a low FPI-III and a high FGI-III, so they have a high fire risk rating.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.419-421
• /
• 2012

높이 2.5m의 콘크리트 플로팅 함체에 3층 규모의 상부골조가 있는 예제에 대해 동적 유체 해석과 정적 구조 해석을 수행하고 그 결과에 따라 종방향설계, 함체의 상부 및 하부 슬래브, 외벽 및 격벽에 대한 설계를 수행하였다. 환경 하중은 새만금 방파제 내부 정수역을 기준으로 파도주기 3.7초, 유의파고 1.0m와 풍속 40m/s를 적용하였으며, 하중조합은 ASCE/SEI 7-10을 기준으로 설계 하였다. 예제 구조물에 대한 설계 결과 고정하중에 의한 영향이 활하중 및 파랑하중에 비해 크게 나타났으며, 이로 인해 중앙부의 철근비가 높아지므로 고정하중을 감소시키는 방안을 검토하여야 함을 확인하였다. 또한 보의 지속하중에 의한 장기처짐과 추가적인 활하중에 의한 순간 처짐의 값이 허용 처짐값보다 크므로 보에서의 프리스트레싱을 고려해야 할 것으로 판단된다.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.2
• /
• pp.106-117
• /
• 2023

The social impact of hazardous and noxious substances from marine industrial facilities was evaluated, and implications for the application of social impact assessment items and methods required in the process of setting technology-based effluent limitations were derived. The scope of the study was based on marine industrial facilities in Incheon Metropolitan City. The analysis results are as follows. First, the impact on companies and industries was evaluated as "great," but large companies had little impact on operating profit losses, bankruptcy possibilities, and employment losses, while small and medium-sized companies had a large impact. Second, the impact on the community and economy was evaluated as "less," but it is judged that careful policy intervention is needed because the impact of fishing producers, local tourism workers, and the region can be concentrated and large. Third, it is judged that items and methods for calculating social loss costs and social benefits can be usefully applied in the method of setting technology-based effluent limitations.