• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2737-2742
• /
• 2007

Strong wind flow around a building complex was numerically studied by LES. The original motivation of this work stemmed from the efforts to develop a risk assessment technique for windstorm hazards. Lagrangian-averaged scale-invariant dynamic subgrid-scale model was used for turbulence modeling, and a log-law-based wall model was employed on all the solid surfaces including the ground and the surface of buildings to replace the no-slip condition. The shape of buildings was implemented on the Cartesian grid system by an immersed boundary method. Key flow quantities for the risk assessment such as mean and RMS values of pressure on the surface of the selected buildings are presented. In addition, characteristics of the velocity field at some selected locations vital to safety of human beings is also reported.

• 한국항공운항학회지
• /
• 제14권1호
• /
• pp.49-54
• /
• 2006

The purpose of RVSM is to reduce vertical separation minima for aircrafts which operate between FL290- FL410 inclusive in regional airspace, and to increase airspace capacity by providing additional flight levels. In order to introduce RVSM, it is necessary to estimate quantitatively airborne collision risk due to the reduction in vertical separation minimum. In this study, the basic concept of RVSM safety assessment and Reich collision risk model are introduced and mid-air collision risk in Incheon FIR is estimated based on ICAO RVSM safety assessment technique and Reich Model.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
• /
• pp.197-197
• /
• 2002

In terms of the risk assessment, qualitative and quantitative informations are needed to estimate the exposures of environmental pollutants, which may create risks, and those are the information according to the changes caused by the movement of substances from the pollutant and duration.(omitted)

• 한국환경보건학회지
• /
• 제49권6호
• /
• pp.334-343
• /
• 2023

Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

• Advances in Computational Design
• /
• 제2권2호
• /
• pp.121-131
• /
• 2017

Collapse was one of the typical common geological hazards during the construction of tunnels. The risk assessment of collapse was an effective way to ensure the safety of tunnels. We established a prediction model of collapse based on Bayesian Network. 76 large or medium collapses in China were analyzed. The variable set and range of the model were determined according to the statistics. A collapse prediction software was developed and its veracity was also evaluated. At last the software was used to predict tunnel collapses. It effectively evaded the disaster. Establishing the platform can be subsequent perfect. The platform can also be applied to the risk assessment of other tunnel engineering.

• 산업경영시스템학회지
• /
• 제13권21호
• /
• pp.29-41
• /
• 1990

An assessment of risk in industrial and urban environments is essential in the prevention of accident and in the analysis of situations which are hazardous to public health and safety. The risk imposed by a particular hazard increases with the likelihood of occurence of the event, the exposure and the possible consequence of that event. In a traditional approach, the calculation of a quantitative value of risk is usually based on an assignment of numerical values of each of the risk factors. Then the product of the values of likelihood, exposure and consequences called risk score is derived. However vagueness and imprecision in mathematical quantification of risk are equated with fuzziness rather than randomness. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the area of systems safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique based on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.

• 한국전산구조공학회논문집
• /
• 제27권5호
• /
• pp.437-450
• /
• 2014

원전의 항공기 충돌 리스크 평가에 사용되는 대표매개변수를 선정하기 위한 방법론을 개발하였다. 대상 원전은 국내의 대표적인 경수로형 원전 중 하나로 선정하여 3차원 유한요소 해석 모델을 구축하였다. 콘크리트 재료모델에는 소성손상모델이 적용되었으며, 강재는 다중선형곡선거동을 가지는 것으로 모델링하였다. 운동에너지, 전체 충격량, 최대 충격량, 최대 하중등 4종의 대표매개변수 후보군을 선정하였다. 각각의 매개변수 후보군은 모두 충돌 속도와 질량의 함수로 표현되므로, 충돌속도 50~200m/s, 항공유량 30~90%의 범위에 대하여 매개변수값을 도출하고 충돌 해석을 수행하여, 충돌 시의 구조 응답과의 상관관계를 분석하였다. 모든 해석에서 항공기의 기종은 보잉767 기종으로 선정하였다. 충돌해석에는 Riera의 하중-시간 이력 함수를 이용한 해석기법을 적용하였다. 매개변수와 충돌 시 응답의 상관관계 적합성은 결정계수값을 이용하여 분석하였다. 4 종의 대표매개변수 후보군 중 최대 하중값이 가장 직관적일 뿐만 아니라 본 연구에서의 해석 케이스에서는 응답과의 상관성도 가장 뛰어난 것으로 나타남에 따라, 항공기충돌 리스크 평가를 위하여 가장 적합한 매개변수라 할 수 있을 것으로 판단되었다.

• 한국축산식품학회지
• /
• 제32권1호
• /
• pp.118-124
• /
• 2012

본 연구는 햄 및 소시지류에서의 Clostridium perfringens에 대한 정량적 미생물 위해평가(Quantitative microbial risk assessment; QMRA)를 국제기준(Codex)의 원칙과 지침에 따라 수행하였으며, 오염수준에 대한 직접적인 분석결과와 현재의 국내 유통환경, 관련제품의 특성, 섭취량 및 소비행태 등을 반영한 노출평가용 "product-retail-consumption pathway" frame-work 모델을 구성하였고, 이를 바탕으로 엑셀(Excel)기반 노출평가용 시뮬레이션 모델을 개발하여 제시하였다. 개발된 모델을 시뮬레이션 프로그램인 @RISK를 활용하여 위해(risk) 수준을 산출하였으며, 그 결과 국내에서 1일 1인이 햄 및 소시지류의 섭취를 통한 Cl. perfringens에 의한 식중독발생 확률은 평균적으로 $3.97{\times}10^{-11}{\pm}1.80{\times}10^{-9}$으로 추정하였다. 또한 본 연구에서 수행한 QMRA결과를 바탕으로 현재수준에서의 한계점과 미래에 더욱 발전된 국내 QMRA 연구 및 활용을 위한 제언을 추가하였다

• 환경영향평가
• /
• 제22권1호
• /
• pp.89-97
• /
• 2013

RADCONS Ver. 1.0 (RADiological CONSequence Assessment Program) was developed for radiological risk assessment in this study. A Gaussian plume model was used to analyze the fate and transport of radionuclides released into the air in case of accidents. Both single meterological data and time series meterological data can be used in RADCONS. To assess the radiological risk of the early phase after an accident, ED (Effective Dose) estimated by both deterministic and probabilistic approaches are presented. These EDs by deterministic and probabilistic will be helpful to efficient decision making for decision makers. External doses from deposited materials by time are presented for quantifying the effects of mid and late phases of an accident. A radiological risk assessment was conducted using RADCONS for an accident scenario of 1 Ci of Cs-137. The maximum of ED for radii of 1,000 meters from the accident point was 8.51E-4 mSv. After Monte-Carlo simulation, considering the uncertainty of the breathing rate and dispersion parameters, the average ED was 8.49E-4, and the 95 percentile was 1.10E-3. A data base of the dose coefficients and a sampling module of the meteorological data will be modified to improve the user's convenience in the next version.

• 한국재난관리표준학회지
• /
• 제1권3호
• /
• pp.69-76
• /
• 2008

본 연구는 철도를 통한 위험물 운송시 발생할 수 있는 위험을 정량화하는 방법을 개발하고, 이를 통한 경감대책을 제시한다. 본 논문에서는 철도위험물 수송에 관한 위험도를 평가하기 위한 방법으로 정량적 위험도 평가 방법을 채택하였으며, 과거 사고이력과 더불어 위험이 높을 것으로 판단되는 익산시를 대상으로 했다. 노출인원에 대한 평균개인의 위험을 거리에 따른 위험도로 표현한 결과 원자력 기준 미만으로 안전한 것으로 판단되고, 또한 사회적 위험도로 표현한 결과, 위험경감대책 적용요구 구간(ALARP)범위 내에 포함되어 이에 대한 경감대책을 제시하였다. 위험 경감대책으로 차량설계, 운영, 피해확대 방지, 발생빈도 감소를 위한 탈선사고 방지, 경로변경 방안 등을 제시하였으며 경감대책의 적용으로 높은 수준의 안전성을 확보할 수 있을 것으로 기대된다.