• Journal of the Korea Safety Management & Science
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• v.9 no.1
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• pp.23-35
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• 2007

Present time there are many risk analysis method in the world. A hazard is an exposure that has the potential to induce and adverse event. Risk is the probability of an adverse event given exposure to hazard. The evaluation of scientific information on the hazardous properties of environmental agents and the extent of exposure to these agents. But operation risk analysis method is not enough for manufacturing industry even if it is existence, it will be separated to improve Safety. In this paper, I will develop the AHP Weighted operation risk analysis method to improve Safety.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.21
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• pp.29-41
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• 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.

• Ocean Systems Engineering
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• v.8 no.1
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• pp.41-55
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• 2018

Accidental oil and gas leak is a critical concern for the offshore industry because it can lead to severe consequences and as a result, it is imperative to evaluate the probabilities of occurrence of the consequences of the leakage in order to assess the risk. Event Tree Analysis (ETA) is a technique to identify the consequences that can result from the occurrence of a hazardous event. The probability of occurrence of the consequences is evaluated by the ETA, based on the failure probabilities of the sequential events. Conventional ETA deals with events with crisp failure probabilities. In offshore applications, it is often difficult to arrive at a single probability measure due to lack of data or imprecision in data. In such a scenario, fuzzy set theory can be applied to handle imprecision and data uncertainty. This paper presents fuzzy ETA (FETA) methodology to compute the probability of the outcomes initiated due to oil/gas leak in an actual offshore-onshore installation. Post FETA, sensitivity analysis by Fuzzy Weighted Index (FWI) method is performed to find the event that has the maximum contribution to the severe sequences. It is found that events of 'ignition', spreading of fire to 'equipment' and 'other areas' are the highest contributors to the severe consequences, followed by failure of 'leak detection' and 'fire detection' and 'fire water not being effective'. It is also found that the frequency of severe consequences that are catastrophic in nature obtained by ETA is one order less than that obtained by FETA, thereby implying that in ETA, the uncertainty does not propagate through the event tree. The ranking of severe sequences based on their probability, however, are identical in both ETA and FETA.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.28-37
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• 2024

The recent surge in the production and handling of hazardous materials in Korea necessitates developing and implementing robust emergency response plans. These plans are crucial in safeguarding the well-being of workers and residents in the event of an incident. The consequence analysis methodology outlined in the KOSHA guidelines provides a foundation for designing emergency response plans in the event of chemical accidents. However, the consequence analysis is evaluated based on assumed accident cases or worst-case scenarios. Consequently, the emergency response plan based on the consequence analysis may overestimate the damage area, complicating rescue efforts and unnecessarily increasing costs. More information and parameters become available after an accident, enabling more accurate consequence analysis. This implies that the results of consequence analysis based on this detailed information provide more realistic results than those based on assumed accidents. This study attempts to optimize the resource allocation and cost-effectiveness of emergency response plans for chemical accidents. Existing procedures and manuals are revised to elucidate the proposed model and conduct real-time consequence analysis. The existing emergency response plan is compared to verify the proposed model's efficacy. The obtained results indicate that the proposed model can exhibit better performance.

• Journal of the Korean Institute of Gas
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• v.14 no.5
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• pp.38-44
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• 2010

This treatise analyzed the risk of propylene transported by railroad through quantitative analysis. As a result of survey on propylene transportation route, Iksan station, Suncheon station and Jeonju station were selected as object regions those were expected to have high accident risks. This treatise deduced the scenario of accident and the occurrence rate in accordance with the type of accident possibly to be happening during propylene transportation through ETA( Event Tree Analysis), and expressed the level of personal, social risks after calculating the level of demage influencing over surroundings based on the evaluation for the expected accident damage through PHAST 6.53.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.23-28
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• 2017

Hazard evaluation and FTA are performed as the first and the second step of QRA for a LNG storage tank. Hazards are identified using HAZOP. Each segment of the system is examined, and we list all possible deviations from normal operating conditions and how they might occur. The consequences on the process are assessed, and the means available to detect and correct the deviations are reviewed. The FTA is carried out to analyse the hazards identified from the HAZOP study. A top event is selected to be release of LNG. Then all combinations of individual failures that can lead to the hazardous event are shown in the logical format of the fault tree system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.145-154
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• 2013

HNS, including crude oil and products, shipments have increased. The risk analysis of HNS has assumed the importance, especially in maritime transportation area. There are various forms and kinds of HNS and the consequences of an accident are serious. In order to provide practical measures for preventing accidents, this study analyses the potential risks of HNS on maritime transportation accidents at domestic sea by using Event Tree Analysis. This study carries out risk assessment with F-N curve and risk matrix focusing on liquid cargo carriers (Oil and Products Tanker, Chemical Tanker, LPG/LNG Tanker, etc.). Explosion and sinking, suffocation indicate high consequence when on collision represent high probability. Improving human errors should be the main factor to mitigate risk on human lives.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.55-62
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• 2014

In this study, we investigated the landslides area which occurred in Umyeonsan in 2011 and collected landslide location data. Using this field data with aerial photos and LiDAR data which is obtained before and after disaster event, we analyzed the landslide occurrence frequency per unit area about various topographic characteristics. In case of slope, we compared two kind of slopes which are calculated with Neighborhood algorithm and maximum slope algorithm. Also we used aspect, elevation, profile curvature and planform curvature in topographic analysis of landslide occurrence locations. As a result, the region of which maximum slope is $40^{\circ}-45^{\circ}$ is relatively hazardous in landslide. If the perpendicular surface to the direction of the maximum slope is concave, it is more hazardous than other case.

• Wind and Structures
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• v.2 no.3
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• pp.133-150
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• 1999

Significant costs to the public and private sectors due to recent extreme wind events have motivated the need for systematic post-hurricane damage data collection and analysis. Current post disaster data are collected by many different interested groups such as government agencies, voluntary disaster relief agencies, representatives of media companies, academicians and companies in the private sector. Each group has an interest in a particular type of data. However, members of each group collect data using different techniques. This disparity in data is not conducive to quantifying damage data and, therefore, inhibits the statistical and spatial description of damage and comparisons of damage among different extreme wind events. The data collection does not allow comparisons of data or results of analyses within a group and also prohibits comparison of damage data and information among different groups. Typically, analyses of data from a given event lead to different conclusion depending upon the definition of damage used by individual investigators and the type of data collected making it difficult for members of groups to compare the results of their analyses with a common language and basis. A formal method of data collection and analysis-within any single group-would allow comparisons to be made among different individuals, hazardous events and eventually among different groups, thus facilitating the management and reduction of damage due to future disaster. This research introduces a definition of damage to single family dwellings, and a common method of data collection and analysis suited for groups interested in regional characterization of damage. The current state-of-data is presented and a method for data collection is recommended based on these existing data collection methods. A fixed-scale damage index is proposed to consider the damage to a dwelling's feature. Finally, the damage index is applied to three dwellings damaged by Hurricane Iniki (1992). The damage index reflects the reduced functionality of a structure as a single family detached dwelling and provides a means to evaluate regional damage due to a single event or to compare damage due to events of different severity. Evaluation of the damage index and the data available support recommendation for future data collection efforts.

• Journal of Navigation and Port Research
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• v.46 no.5
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• pp.400-408
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• 2022

Maritime transportation is one of the most complicated and hazardous business fileds. Maritime accidents still occur despite several precautions since maritime is exposed to natural factors more than any other industries. In this harsh environment as a part of their job, marine pilots often embark/disembark to/ from vessels and confront life-endangering personal accidents. In the maritime field, several risk assessments are applied. However, all of them could not evaluate occupational accident risk for maritime pilot specifically. This paper performs specific risk analysis using the bow-tie method based on past accident records. This paper aims to qualify root causes and quantify root causes by importance level according to occurrence probability. As a result of analysis, occupational accident occurrence probability is found to be 14%, indicating that accident occurrence rate is significantly high. Hence, the probability of root causes triggering accidents and accident occurrence probability can be ascertained so that preventive measurements can be implemented. Besides theoretical achievement, this paper provides safety awareness to marine pilots, Marine Pilot Organizations, and ship crew who play a key role during marine pilots' transfer.