• International conference on construction engineering and project management
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• 2005.10a
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• pp.748-753
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• 2005

In a super-highrise residence project, a project manager needs to form the long-term risk management plan which covers the problems from the beginning of project to the time of demolition. The cause and responsibility for a risk are clarified and quantitatively evaluated through the life cycle of a project. Development of the system which supports a risk strategy effectively is needed as a project becomes complex. In this paper, through the life cycle of a specific super-highrise residence project, a risk phenomenon is specified from a viewpoint of each participant, and the mathematical model is formulated choosing the combination of the optimal strategy against a risk quantitatively within a fixed risk strategy budget.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.75-86
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• 2024

Hydrogen has been selected as one of the key technologies for reducing CO₂ emissions to achieve carbon neutrality by 2050. However, hydrogen safety issues should be fully guaranteed before the commercial and widespread utilization of hydrogen. Here, a bow-tie risk assessment is conducted for the hydrogen fuel supply system in a gas turbine power plant, which can be a mass consumption application of hydrogen. The bow-tie program is utilized for a qualitative risk assessment, allowing the analysis of the causes and consequences according to the stages of accidents. This study proposed an advanced bow-tie method, which includes the barrier criticality matrix and visualized maps of quantitative risk reduction. It is based on evaluating the importance of numerous barriers for the extent of their impact. In addition, it emphasizes the prioritization and concentrated management of high-importance barriers. The radar chart of a bow tie allows the visual comparison of risk levels before/after the application of barriers (safety measures). The risk reduction methods are semi-quantitatively analyzed utilizing the criticality matrix and radar chart, and risk factors from multiple aspects are derived. For establishing a secure hydrogen fuel storage system, the improvements suggested by the bow-tie risk assessment results, such as 'Ergonomic equipment design to prevent human error' and 'Emergency shutdown system,' will enhance the safety level. It attempts to contribute to the development and enhancement of an efficient safety management system by suggesting a method of calculating the importance of barriers based on the bow-tie risk assessment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.2
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• pp.70-78
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• 2013

Plants which are having conditions of high temperature and pressure always are exposed to danger. In order to prevent unexpected accidents, safety management that can effectively and appropriately examine facilities is required in plant operation. RBI(Risk-Based Inspection) technology in API 581 is one of standard management technique for evaluating risk on petroleum plants. There are qualitative and quantitative assessments in RBI methodology. Quantitative evaluation step is complex and required much information, so high-risk facilities in plant are selected firstly by qualitative method. Qualitative RBI is performed by choosing the answer in prepared questionnaire. However, it is difficult to believe thoroughly results from survey including ambiguous information. In this study, the procedure of qualitative RBI analysis with considering probability distribution concept were proposed by using Monte Carlo simulation method in order to increase reliability in spite of uncertain factors. In addition, qualitative risk of cooling system for LNG plant was evaluated using proposed procedure. Although 20 items of total 39 assessment items are applied to uncertain factors, risk section of high probability(89%) were verified. The detailed results were described in manuscript.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.83-91
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• 2020

The recent bridge construction projects is demanded more sophisticated risk management measures and loss forecasts to brace for risk losses from an increase in the trend of bridge construction. This study aims to analyze the risk factors that caused the loss of material in actual bridge construction and to develop a quantified predictive loss model, based on the past record of insurance payment by major domestic insurance companies for bridge construction projects. For the development of quantitative bridge construction loss model, the dependent variable was selected as the loss ratio, i.e., the ratio of insurance payout divided by the total project cost, while the independent variable adopted 1) Technical factors: superstructure type, foundation type, construction method, and bridge length 2) Natural hazards: typhoon and flood 3) Project information: construction period and total project cost. Among the selected independent variables, superstructure type, construction method, and project period were shown to affect the ratio of bridge construction losses. The results of this study can provide government agencies, bridge construction design and construction and insurance companies with the quantitative damage prediction and risk assessment services, using risk indicators and loss prediction functions derived from the findings of this study and can be used as a guideline for future basic bridge risk assessment development research.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.111-116
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• 2012

This study is about the quantitative safety assessment of hydrogen station in Korea operating with on-site type. This was written by background information that before qualitative safety assessment to write. For the qualitative safety assessment method, the study used FMEA(failure mode & effect analysis) and HAZOP(hazard & operability), and adopted the FTA(fault tree analysis) as the quantitative safety assessment method. To write the FTA, we wrote FT by Top event that hydrogen leakage can be called most serious accident of hydrogen station. Each base event collect reliability data by reliability data handbook, THERP-HRA and estimation of the engineering. Assessment looked at the high frequency and the possible risk through Gate, Importance, m.cutsets analysis.

• 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.

• Journal of Environmental Impact Assessment
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• v.2 no.2
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• pp.59-71
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• 1993

Evaluation methods are employed in environmental impact assessment to choose between different project site, to determine the required measures to compensate impact and to decide whether the environmental impacts are more important than the social or economic effects of a project. The main obstacles that restrict use of quantitative evaluation method are a Lack of knowledge about the environmental effects (e.g. if impacts on wildlife or landscape amenities are predicted) and the relative importance of economic and social issues compared with nature conservation stability of ecosystem or landscape beauty. In Germany, the most common method for site planning is the "ecological risk analysis". It is a kind of multi-criteria-decision-method based on quantitative and qualitative description and ordinal ranking. The various kinds of "ecological balancing methods" that are more recently developed (within the last decade) to quantify the required amount for compensatory measures instead often use cardinal figures to express the value of ecosystems, the intensity of impacts, the need for additional measures to compensate for long recuperative periods when restoring ecosystems and so on. There are still only a view attempts to quantify decisions between environmental and socio-economic issues. Multicriteria-analysis as well as cost-benifit-analysis was used. Some new approaches which are still in a preliminary status are based on contingent valuation and on calculations for compensatory payments (instead of compensatory measures).

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.45-51
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• 2021

A runway safety area (RSA) is defined as the surface surrounding the runway prepared or suitable for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway. The Runway Stripe is a defined area including the runway stopway, if provided, intended firstly to reduce the risk of damage to aircraft running off a runway, and secondly, to protect aircraft flying over it during takeoff or landing operations. This study used 2 RSA analysis models; RSARA and LRSARA. The analysis utilizes historical data from the specific airport and allows to take into consideration specific operational conditions to which movements are subject, as well as the actual or planned RSA conditions in terms of dimensions, configuration, and boundaries defined by existing obstacles. This study applied the RSA and LRSA risk assessment models to a domestic airport that do not meet the criteria required by standards for aerodrome physical characteristics. The airport is considering a method to secure the runway strip standard through the displaced threshold. This study intends to confirm through quantitative risk estimation whether meeting facility standards through the runway displaced threshold leads to a positive change in risk mitigation.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.192-194
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• 2015

The growing size and complex process in construction project recently leads to increase risk and the losses as well. Even though researchers have identified the major risk indicators, there is lack of comprehensive and quantitative research for identifying the relationship between the risk indicators and economic losses associated with construction projects. To address this shortage of research, this study defines risk indicators and create a framework to assess the influence of economic losses from the indicators. An insurance company's claim payout record was accepted as the dependent variable to reflect the real economic losses. Based on the claims, we categorized the causes and results of accidents. To establish framework, built environment vulnerability indicators and geographical vulnerability indicators were employed as the risk indicators. A Pearson correlation analysis was adopted to validate the relationship with loss ratio and risk indicators. Consequently, this framework and its results may offer significant references for under writers of insurance companies and loss prevention activities.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.433-440
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• 2023

This study aims to establish safety zones for bunkering operations of hydrogen propulsion ships in coastal areas through risk assessment and evaluate their validity. Using a 350 kW-class ferry operating in Busan Port as the subject of analysis, with quantitative risk assessment based on accident consequence and frequency analysis, along with a social risk assessment considering population density. The results of the risk assessment indicate that all scenarios were within acceptable risk criteria and ALARP region. The most critical accident scenarios involve complete hose rupture during bunkering, resulting in jet flames (Frequency: 2.76E-06, Fatalities: 9.81) and vapor cloud explosions (Frequency: 1.33E-08, Fatalities: 14.24). For the recommended safety zone criteria in the 6% hose cross-sectional area leakage scenario, It could be appropriate criteria considering overall risk level and safety zones criteria for hydrogen vehicle refueling stations. This research contributes to establishing safety zone for bunkering operations of hydrogen propulsion ships through risk assessment and provides valuable technical guidelines.