• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.22-32
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• 2019

On offshore platforms, oil and gas leaks are apt to be the initial events of major accidents that may result in significant loss of life and property damage. To prevent accidents induced by leakage, it is vital to perform a case-specific and accurate risk assessment. This paper presents an integrated method of Ddynamic Qquantitative Rrisk Aassessment (DQRA)-using the Decision Making Trial and Evaluation Laboratory (DEMATEL)-Bayesian Network (BN)-for evaluation of the system vulnerabilities and prediction of the occurrence probabilities of accidents induced by leakage. In the method, three-level indicators are established to identify factors, events, and subsystems that may lead to leakage, fire, and explosion. The critical indicators that directly influence the evolution of risk are identified using DEMATEL. Then, a sequential model is developed to describe the escalation of initial events using an Event Tree (ET), which is converted into a BN to calculate the posterior probabilities of indicators. Using the newly introduced accident precursor data, the failure probabilities of safety barriers and basic factors, and the occurrence probabilities of different consequences can be updated using the BN. The proposed method overcomes the limitations of traditional methods that cannot effectively utilize the operational data of platforms. This work shows trends of accident risks over time and provides useful information for risk control of floating marine platforms.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.474-478
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• 2018

For process safety, fire and explosion characteristics of combustible materials handled at industrial fields must be available. The combustion properties for the prevention of the accidents in the work place are flash point, fire point, explosion limit, and autoignition temperature (AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. In the chemical industries, n-ethylaniline which is widely used as a raw material of intermediate products and rubber chemicals was selected. For safe handling of n-ethyl aniline, the flash point, the fire point and the AIT were measured. The lower explosion limit (LEL)of n-ethylaniline was calculated using the lower flash point obtained in the experiment. The flash points of n- ethylaniline by using the Setaflash and Pensky-Martens closed-cup testers measured $77^{\circ}C$ and $82^{\circ}C$, respectively. The flash points of n-ethylaniline using the Tag and Cleveland open cup testers are measured $85^{\circ}C$ and $92^{\circ}C$, respectively. The AIT of the measured n-ethyl aniline by the ASTM E659 apparatus was measured at $396^{\circ}C$. The LEL of n-ethylaniline measured by Setaflash closed-cup tester at $77^{\circ}C$ was calculated to be 1.02 vol%. In this study, it was possible to predict the LEL by using the lower flash point of n-ethylaniline measured by closed-cup tester. The relationship between the ignition temperature and the ignition delay time of the n-ethylaniline proposed in this study makes it possible to predict the ignition delay time at different ignition temperatures.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.69-76
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• 2008

Three failure cases of CNG composite vessels were reported since after January 2005. The 1st and 2nd accidents were indebted to vessel defect and installation mistake. The 3rd was caused by gas leak at pipe connections. In this paper various aspects were studied based on information of the three failure analysis, which must be improved for better safety of the CNG bus system. Overpressure region caused by vessel explosion was theoretically predicted and also assessed by PHAST program. Explosion of 120 l vessel under 20 MPa is equivalent to 1.2 kg TNT explosion. The predicted value by PHAST was more serious than theoretical one. However, actual consequence of explosion was much less than both of the predicted consequences. Since the CNG vessel was designed by the performance based design methodology, it is difficult to verify whether the required process and tests were properly conducted or not after production. If material toughness is not enough, the vessel should be weak in brittle fracture at early in the morning of winter season since the metal temperature can be lower than the transition temperature. If autofrettage pressure is not correct, fatigue failure due to tensile stress during repeated charging is possible. One positive aspect is that fire did not ocurred after vessel failure. This may be indebted to fast diffusion of natural gas which hindered starting fire.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.43-49
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• 1968

Epidemiological and statistical observations were made of fire hazards that occurred during the past 18 years, 1948 to 1965. Injury and mortality rates for all ages were computed chronologically. For the years of 1955, 1961 and 1965, all fire accidents were epidemiologically analysed to draw characteristic patterns in relation to the seasonal and 24 hour distribution, causes and sites of accidents etc.. Fire hazards observed herein are the categorys E 916 of the International Classification of Causes of Death, 1955, and includes all accidents caused by fire and explosion of combustible materials. The following conclusion was made: 1. The average number of annual deaths due to fire was 183 and the number of the in jured due to the same cause was 335. The mortality rate per 100,000 population was 0.8 and the ratio of injuries per death was 1.83. 2. The casually rate including both the dead and injured was 5.0 per 100,000 in Seoul, the highest among the provinces and followed by 3.4 in Cheju -Do, 2.1 in Kangwon-Do, 1.7 in Kyunggi-Do accordingly. The other provinces had a range of 0.6 to 1.2. 3. The monthly distribution of fro accidents showed that the winter months, December through February, had more frequent accidents, while the summer season, June through August had less. The 24 hour distribution of accidents showed more cases from 12:00 to 18:00 and less from 4:00 to 10:00 hours. 4. The per cent distribution of causes of accidents showed; 90.0% for careless, 10.0% for arson. The cause of carelessness was further breakdown into; 15.0% for kitchen fire places, 13.8% for fire playing, 9,4% for electrical heating and wires, 8.3% for fuels, 6.3% for matches, 5.2% for ash dumps and the remaining for others. 5. The accidents as classified by place revealed that 56.8% of the total occurred at the common dwelling houses, 11.3 at various industrial workshops, 9.3% at the street shops and the remaining at the miscellaneous places.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.3 s.18
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• pp.83-88
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• 2005

It is necessary to hold the school safety manual because recently, the safety-related accidents occur frequently in schools. Accidents can occur inside of schools as well as out of schools, and they can be classified with human accidents, traffic accidents, fire accidents, and explosion accidents. Safety-related accidents occurring in the school are dangerous because nobody can predict them. Illegally infringing violence, targeting unspecified and a lot of people, informs the parents and persons concerned to education of danger. School safety manual, never precedented before, describes epoch-making educational methods for students' safety. It describes safety security such as refuging ways at an emergency, the way to recognize danger for elevated safety based on prevention education, the use and practice of checklist for related facilities, and the implements and facilities for school personnels and students. So, the school safety manual is an important guidance for safety education at the level of prevention from various accidents which occur inside the school as well as out of the school. It presents a variety of prompt response after an accident. At the same time, it checks facilities and dangerous factors in schools and facilities for safety, and analyzes special factors based on them. So it will present the status of safety management of existing facilities and implements, the installment of new facilities and implements, and the way to secure safety for use.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.10-19
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• 2020

Valve leak accidents in petrochemistry plants and gas utilities cause human and property damage. The main reason why happen gas inhalation, poisoning, fire and explosion accidents is gas valve leakage. To prevent gas leakage, inspectors check the facilities in the field. And they are at risk of gas leak accidents. So we applied IoT-based risk assessment, monitoring and automatic control system. It can detect both internal and external gas leakage, do real-time monitoring of industrial valve in the plant by using hybrid sensor. As the new safety management system for industrial valve is developed, it needs method to evaluate device performance and environmental components for the system. This study is about development of method to verify performance of the explosion-proofed hybrid sensing system include gas detector and optical fiber sensor supporting wire and wireless communication.

• Journal of East-West Nursing Research
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• v.13 no.2
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• pp.130-137
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• 2007

Purpose: This study aimed to identify the safety perception and behaviors of mothers with school age children. Method: The subjects were 265 mothers of third graders in one elementary school located in metropolitan Seoul area. Framingham safety survey were used to guide the development of a self administered questionnaire for mothers. The questionnaire were sent home at school and the children returned them to their class teachers. Results: Among 265 mothers, 62 mothers (23.4%) had experience of visiting hospitals because of accidents and 201 mothers (75.8%) had no opportunities on safety education. Mothers with education higher than high school graduation showed more safety behaviors. Also, mothers having the experience of safety education showed higher scores on safety behaviors and mothers with the experience of hospital visits related to accidents showed low scores on safety behaviors. In the practice of safety behaviors, it showed high score to the traffic safety, followed by the home safety, child supervision, the safety from fire and explosion, the safety from electric devices, the safety from burn, and the safety from medicines. Conclusion: Mothers' overall practice on safety were poor. Based on these results, it is necessary to provide more safety education for mothers with school age children.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.3
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• pp.222-235
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• 2018

The hydrocarbon gas leak in the offshore plant can cause large accidents and lead to significant damages to human, property and environment. For prevention of fire or explosion accidents from gas leak, a SIS(Safety Instrumented System) should be installed. In the early stage of the offshore design, required SIL(Safety Integrated Level) is determined and reliability analysis is performed to verify the design in reliability aspects. This study collected data, information related to reliability analysis and created knowledge model of safety design for the offshore system with MBSE(Model-Based Systems Engineering) concept. Knowledge model could support safety engineer's design tasks as the guidance of reliability analysis procedure of safety design and make good conversation with other engineers in yard, class, company, etc.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.193-202
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• 2005

Marine risk assessment considers events such as collision/grounding, sinking/capsize, fire/explosion and flooding, developing relationships between their causes and effects. In addition, risk assessment of previously sunken ships are also necessary since they continuously have possibility for further oil spill or can cause other marine accidents. The objective of this paper is to develop the risk assessment systems for sunken ships to prevent oil spill and further marine causalities in order to preserve safe and clean oceans around Korea peninsula. The risk assessment systems for sunken ships comprise of database management sub-system for sunken ships, qualitative risk assessment sub-system, quantitative risk assessment sub-system, and cost-benefit analysis subsystem.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.4
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• pp.294-300
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• 2017

The offshore installations and ships are the structures most likely to be exposed to hazards such as hydrocarbon fire and/or explosion. Developing proactive measures to prevent the escalation of such events thus requires detailed knowledge of the related phenomena and their consequences. $CO_2$ extinguishing systems are extensively used for fire accidents of on-and offshore installations because of outstanding performance and low cost. There is, however, the risk of carbon dioxide system which enumerates many of the fatalities by suffocation associated with industrial fire protection requirements. Therefore, the aim of this study is to perform the prediction of fire suppression characteristics of the carbon dioxide system in realistic enclosed compartment area of ships and propose $CO_2$ extinguish fire fighting system for preventing suffocation accidents during fire fighting. According to CFD calculations, it can be observed and assessed that various fire profiles with $CO_2$ and $O_2$ mole fraction in the target enclosed compartment area are applicable within the proposed system. Additionally, the design of fire safety system of ships and offshore installations can utilize ventilation system and/or layout arrangement through the proposed system.