• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1499-1504
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• 2008

This study shows risk-based evaluation results of casualty accidents for passengers, railway staffs and MOP(Member of public) on the national railway in South Korea. To evaluate risk of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. A probability evaluation model for each hazardous event which was based on the accident appearance scenario was developed by using the Fault Tree Analysis (FTA) technique. The probability for each hazardous event was evaluated from the historical data and structured expert judgment. In addition, the severity assessment model utilized by the Event Tree Analysis (ETA) technique was composed of the accident progress scenarios. And the severity for the hazardous events was estimated using fatalities and weighted injuries. The risk assessment model developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.190-198
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• 2009

This study shows the developing process of the risk assessment models for railway casualty accidents. To evaluate the risks of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. The frequency of each hazardous event was evaluated from the historical accident data and structured expert judgments by using the Fault Tree Analysis (FTA) technique. In addition, to assess the severity of each hazardous event, the ETA (Event Tree Analysis) technique and other safety techniques were applied. The risk assessment models developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1518-1523
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• 2008

Train collision and derailment are types of accident with low probability of occurrence, but they could lead to disastrous consequences including loss of lives and properties. The development of the risk assessment model has been called upon to predict and assess the risk for a long time. Nevertheless, the risk assessment model is recently introduced to the railway system in Korea. The classification of the hazardous events and causes is the commencement of the risk assessment model. In previous researches related to the classification, the hazardous events and causes were classified by centering the results. That classification was simple, but might not show the root cause of the hazardous events. This study has classified the train collision and derailment based on the relevant hazardous event including faults of the train related the accidents, and investigates the causes related to the hazardous events. For the risk assessment model, FTA (fault tree analysis) and ETA (event tree analysis) methods are introduced to assess the risk.

• Journal of the Ergonomics Society of Korea
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• v.22 no.1
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• pp.81-94
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• 2003

The British railway safety research group has developed a risk assessment model for the railway infrastructure and major railway accidents. The major hazardous factors of the railway infrastructure were identified and classified in the model. The frequency rates of critical top events were predicted by the fault tree analysis method using failure data of the railway system components and ratings of railway maintenance experts, The consequences of critical top events were predicted by the event tree analysis method. They classified the Joss of accident due to railway system into personal. commercial and environmental damages. They also classified 110 hazardous event due to railway system into three categories. train accident. movement accident and non-movement accident. The risk assessment model of the British railway system has been designed to take full account of both the high frequency low consequence type events (events occurring routinely for which there is significant quantity of recorded data) and the low frequency high consequence events (events occurring rarely for which there is little recorded data). The results for each hazardous event were presented in terms of the frequency of occurrence (number of events/year) and the risk (number of equivalent fatalities per year).

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.79-87
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• 2009

The objective of this study is to develop accident scenario models for the risk assessment of railway casualty accidents. To develop these scenario models, hazardous events and hazardous factors were identified by gathering various accident reports and information. Then, the accident scenario models were built up. Each accident scenario model consists of an occurrence scenario model and a progress scenario model. The occurrence scenario refers to the occurrence process of the event before the hazardous event. The progress scenario means the progress process of the event after the hazardous event. To manage a large amount of accident/incident data and scenarios, a railway accident analysis information system was developed using railway accident scenario models. To test the feasibility of the developed scenario models, more than 800 domestic railway casualty accidents that occurred in 2004 and 2005 were investigated and quantitative and qualitative analyses were performed using the developed information system.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.160-167
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• 2014

To determine a proper ASIL for each hazardous event with a proper safety goal, the right classes should first be determined for the three properties of the hazardous event; (i) severity of harm from the resultant accident, (ii) exposure to the relevant operational situation, and (iii) controllability to avoid the induced risks. ASIL can be clearly determined with right classes of these three properties. But no specific methodologies or processes for their classification can be found in ISO 26262, except only a rough guideline with a simplified set of illustrative tables. In this paper, we try to present a systematic model for classifying the three properties of the hazardous event and suggest a refined procedure of ASIL determination. The proposed model provides a specific method to get a more objective ASIL compared with that in the standard. Scrutinizing the current methodology, we develop a refined method and also provide an illustrative example.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.23-31
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• 2015

Aquifer storage transfer and recovery (ASTR) is a type of managed aquifer recharge which entails injecting water into a storage well and recovering it from a different well. It has effects of natural purification when injected water passes through aquifer medium, and can be a good way of supplying water especially in a region with poor surface water quality. This study is about an on-going effort to introduce ASTR as a solution to source water problems in coastal areas. A pilot study is being conducted in the delta of the Nakdong River. A proactive management system is incorporated to ensure the water qulity in the process of drinking water process. The system is based on the Hazard Analysis and Critical Control Point (HACCP) which is a tool originated from the food industry in order to assess hazards and establish control systems for the safety of food product. In this paper, we analyze hazardous events which can occur in the entire water supply system using ASTR as a first step to the incorporation of HACCP to drinking water production process.

• Analytical Science and Technology
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• v.28 no.2
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• pp.117-124
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• 2015

Genetically modified (GM) papaya line 55-1, which is resistant to PRSV infection, has been marketed globally. Prompt and sensitive protocols for specific detections are essential for the traceability of this line. Here, an event- and construct-specific real-time polymerase chain reaction (RT-PCR) method was established to detect 55-1. Qualitative detection was possible for fresh papaya fruit up to dilutions of 0.005% and 0.01% for the homozygous SunUp and heterozygous Rainbow cultivars, respectively, in non-GM papaya. The method was applied in the qualitative detection of 55-1 in eight types of commercially processed papaya products. Additionally, papaya products were monitored to distinguish GM papaya using the P35S and T-nos RT-PCR detection methods. As expected, detection capacity was improved via modified sample preparation and the established RT-PCR detection method. Taking these results together, it can be suggested that a suitable method for the extraction and purification of DNA from processed papaya products was established for the detection of GM papaya.

• Journal of Korean Society for Quality Management
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• v.19 no.2
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• pp.96-107
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• 1991

At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2116-2120
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• 2008

Recently, in the national railway industry there has been interested in the methodology of hazard analysis and risk assessment. The need of safety management system based on the technology of hazard analysis and risk assessment is being extended to identify in advance the weakness and threat factors causing the accident and cope with the accident actively. It is important to manage the risk of railway casualty accidents having a majority of railway accident. Especially, a hazard event of people struck takes the highest proportion of the railway casualty accidents. This paper describes the result of analysis for environment properties such as an age of casualty, time happened, day, month and weather conditions being concerned in the hazard event of people struck.