• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.917-930
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• 2018

A quantitative risk assessment method for quantitatively evaluating the fire risk in designing a road tunnel disaster prevention facilities has been introduced to evaluate the appropriateness of a disaster prevention facility in a large tunnel through which all vehicle types pass. However, since the quantitative risk assessment method of the developed can be applied only to the large sectional area tunnels (large tunnels), it is necessary to develop a quantitative risk assessment method for road tunnels passing only small cars which has recently been constructed or planned. In this study, fire accidents scenarios and quantitative risk assesment method for small road tunnels through small cars only which is based on the methods for existing road tunnels (large tunnels). And the risk according to the distance between cross passage is evaluated. As a result, in order to satisfy the societal risk assessment criteria, the distance of the appropriate distance between cross passages was estimated to be 200 m, and the effect of the ventilation system of the large port exhaust ventilation system was quantitatively analyzed by comparing the longitudinal ventilation system.

• Journal of Korea Technology Innovation Society
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• v.16 no.1
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• pp.20-40
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• 2013

A project of developing marine environmental risk assesment and management technology was proposed to improve the level of marine environmental management research. This paper attempts to measure the non-market benefits of the project. To this end, the dichotomous choice contingent valuation method is used. In particular, recently proposed one and one-half bounded model is applied. The model can reduce the potential for response bias comparing to the double bounded model while maintaining much of its efficiency. Moreover, in order to deal with zero WTP observations, a spike model is adjusted for our data. A survey of randomly selected 600 households was implemented and the respondents were asked in person-to-person interviews about how they would be willing to pay for implementing the project. Respondents overall accepted the contingent market and were willing to contribute a significant amount (2,663 won), on average, per household per year. The aggregate value of the project in the nation amounts to approximately 46.3 billion won per year. The figure 2.16 of cost-benefit ratio shows that economic validity of this technical development.

• Fire Science and Engineering
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• v.31 no.6
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• pp.1-7
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• 2017

Currently, flammable liquids account for more than 87 wt% of the hazardous materials in circulation in Korea, and paint products are the most commonly used mixed hazardous materials. Therefore, one of the most urgent and important issues is that we have to secure the safety for manufacturing, storage and transport of paint products. In this study we investigated and analyzed the domestic hazardous materials safety management method, the international GHS test method and so forth. We tested risks for a variety of oil paints and found a relation between the results. Furthermore, the risk test method and criteria adapted for domestic situation was presented. Paints were classified as hazardous or non-hazardous according to the results of the flash point test, the amount of flammable liquid or the UN-combustion persistence test. It was revealed from the test results of 6 kind of oil-based paints using different resins that they were hazardous materials with very high risks and belonged to the Category 1 or the Category 2.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.93-104
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• 2008

study deals with the reliability assesment for the 5-year phases of a suspension bridge construction in Korea. The main objectives of this study are; (1) the evaluation of the reliability of a suspension bridge by considering an ultimate limit state for the fracture of main cable wires, (2) the determination of the critical phases among 28 construction stages for the deck erection, and (3) the evaluation of the reliability of the limit state for the erection control during construction stages. The research and the design of the suspension bridge have been focused on the state of construction mainly based on empirical data. Based on the recent survey of the distribution of accidents in Korean railways, over 80% of the accidents related to the uncertainties in human error, planning, design, materials and loads during construction have ben reported before the completion of construction. While many researches have evaluated the safety of bridges, the uncertainties in the construction phases have not been well treated in a guidelines or a specifications. An improved adaptive response surface method is used for the risk assessment in the construction phases of the target suspension bridge.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.2
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• pp.88-95
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• 2009

There are many assessment techniques used for occupational risk factors of MSDs in the workplaces. However, because all ergonomic assesment techniques or tools are based on theoretical background derived from workphysiology, biomechanics, psychophysics, industrial hygiene, work system, and etc, it is impossible to compare the assessment techniques. This study was conducted to compare the excess rates of risk factors among ergonomic assessment techniques and to make alternative methods. Site-visits to 6 automobile products and parts company provided data for process repeated work where the produced data was examined for evaluating the relationship between workplace lay-out and work posture by using ergonomic assessment techniques. We evaluated 157 jobs for simple repeated work and 37 jobs for manual materials handling (MMH). In simple repeated work, the exceeded rates of AC were 36.3% in OWAS method and 93.0% in RULA method. The exceeded rate for RULA method was significantly higher than those for OWAS method (p<0.05). In MMH, the exceeded rates of AC were 80.0% in NLE method and 76.5% in WAC method. Statistically significant differences were not identified in the exceeded rates for NLE and MAC methods (p<0.05). The analyzed results among ergonomic assessment techniques (OWAS, RULA, NLE/WAC) were applied to the same work places performing simple repeated work and manual materials handling simultaneously. The applied results showed statistically significant differences (p<0.05) among ergonomic assessment techniques (OWAS, RULA, NLE/WAC). Exceeded rates of four ergonomic assessment techniques in decreasing order was "RULA>NLE>WAC>OWAS". The RULA method was the strongest assessment technique for automobile products and parts company. We discovered that the results could easily be overestimated or underestimated when the ergonomic assessment techniques were not applied correctly during the evaluation process. Therefore, we recommend using at least 2 methods when evaluating and analysing the results.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.87-101
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• 2012

In gas industries, the potential risks of serious accidents have been increased due to high technology application and process complexities. Especially, in case of gas-related accidents, the extent of demage is out of control since gas plants handle and produce combustible, flammable, explosive and toxic materials in large amounts. The characteristics of this kind of disaster is that accident frequency is low, while the impact of damage is high, extending to the neighboring residents, environment and related industries as well as employees involved. The hydrogen gases treated important things and it used the basic material of chemical plants and industries. Since 2000, this gas stood in the spotlight the substitution energy for reduction of the global warming in particular however it need to compress high pressure(more than 150 bar.g) and store by using the special cylinders due to their low molecular weight. And this gas led to many times the fire and explosion due to leak of it. To reduce these kinds of risks and accidents, it is necessary to improve the new safety management system through a risk management after technically evaluating potential hazards in this process. This study is to carry out the quantitative risk assesment for hydrogen filling plant which are very dangerous(fire and explosive) and using a basic materials of general industries. As a results of this risk assessment, identified the elements important for safety(EIS) and suggested the practical management tools and verified the reliability of this risk assessment model through case study of accident.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.110-122
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• 2009

Purpose: Nowadays, A medical institution assesment could get more interest about a quality of medical services from many hospitals that developed the active activities for improving medical services. Also, there is an other additional issue which is the patients risk management. Uijeongbu ST. Mary's hospital Nuclear Medicine department has been changed many work process after PET-CT introduction and renovation of its place since 2008. Therefore, modified structure and the way of existing work process have contained risk factors. The purpose of this study would be the appropriate risk management process while imaging examination process, the removal risk factors and improved activities through the analysis risk factors. Materials and Methods: Nuclear Medicine department new process should analysis through many-sided, Firstly, make and trained risk management manual after then apply an actual work. Result analysis showed the number of risk accident occurrence that comparing the last year and after the improved activities. Secondly, producing risk management public relations film has been showed an applicable patient after then the customer service measurement checked for a hundred patient by questionnaire. Lastly, Risk factors were eliminated through the facilities participation improving activities which could change for the better risk factors. Results: The number of safety accident occurrence(medication error, fall and collision) were checked as zero after the improving activities both PET-CT and gamma camera examination. The results of questionnaire showed as follows; 74% marked as understanding of the test process and 81% checked "satisfaction" after the public relations film showing. The question "Did you consider about the risk factors?", both PET-CT and gamma camera checked as 94% and 89% respectively. Customer risk management could be accomplished effectively through the improving activities at the nuclear medicine department. Conclusions: The study would be an opportunity that spread risk factors were systematically showed and analyzied. Also, It showed the possibility of the minimized safety accident and its feedback, if application of the response manuel that could be a standard of radiology technician's work method to react safety accident. It was the more effective that visual material could be easy to approach as a methodology of risk factors. As far as I have concerned that It could help the safety and convenience through continuous and detailed activities that offer to patients.

• Fire Science and Engineering
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• v.32 no.5
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• pp.6-14
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• 2018

This study was carried out with respect to the heat release rate (HRR) properties of building wood. Heat release characteristics were measured using a cone calorimeter (ISO 5660-1) with four kinds of wood. The time to ignition measured after the combustion in $25kW/m^2$ external heat flux was 35 to 55 s. Time to ignition of both lauan and red pine was marked with the most delayed value in each of 54 s, 55 s. The maximum heat release rate ($HRR_{peak}$) was $156.87{\sim}235.1kW/m^2$, and the risk of early fire was highest in spruce. Total heat release of red pine was obtained in the highest value with $114.2MJ/m^2$. The mean effective heat of combustion of Japanese cedar was 19.1 MJ/kg and the highest among the samples. Fire risk of wood by FPI was orderly increased from lauan ($0.2468s{\cdot}m^2/kW$), red pine ($0.2339s{\cdot}m^2/kW$), spruce ($0.2308s{\cdot}m^2/kW$) to Japanese cedar ($0.2231s{\cdot}m^2/kW$). Fire risk of wood by FGI get increased from lauan ($0.5088kW/m^2{\cdot}s$), red pine ($0.5111kW/m^2{\cdot}s$), Japanese cedar ($2.8522kW/m^2{\cdot}s$) to spruce ($3.0662kW/m^2{\cdot}s$). Therefore, the risk of fire on the heat release characteristics of woods were found that spruce and Japanese cedar showed the high value compared with the other specimens.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.573-580
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• 2017

The oxicity assesment of Phenanthrene (PHE) has been investigated by using the rate (r) of survival and population growth in rotifer Brachionus plicatilis. The survival rate was determined after 24 h of exposure to PHE. The survival rate of PHE had no effect at a maximum of $300mg\;L^{-1}$. The r was determined after 72 h of exposure to PHE. It was observed that r in the controls (absence PHE) was greater than 0.5, but that it suddenly decreased with an increased concentration of PHE. PHE reduced r in a dose-dependent manner and a significant reduction occurred at a concentration of greater than $37.5mg\;L^{-1}$. The $EC_{50}$ value of r in PHE exposure was $63.7mg\;L^{-1}$. The no-observed-effect-concentration (NOEC) of r in PHE exposure was $18.8mg\;L^{-1}$. The lowest-observed-effect-concentration (LOEC) of r in the PHE exposure was $37.5mg\;L^{-1}$. From the results, the concentration of PHE (greater than $37.5mg\;L^{-1}$) has a toxic effect on the r of B. plicatilis in natural ecosystems. These results(including NOEC, LOEC and $EC_{50}$) might be useful for the Polycyclic aromatic hydrocarbons(PAHs) toxicity assessment in marine ecosystems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.605-611
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• 2010

The geostationary satellite COMS is going to be launched in 2010, and, in the series of test, there are some high-pressure tests concerning the vessel tank filled with helium gas of hundreds atmospheric pressure. In this paper, authors evaluates risk associated with accidental rupture of the test system. Two possible scenarios are considered: 1) the 310-bar helium tank ruptures at the center of the acoustic chamber, and 2) the 116-bar reduced-pressure helium tank ruptures in the test room shielded by bullet-proof glasses. Using the theory of blast wave propagation and computational simulation, the dynamics of wave reflected in a confined space is investigated for highly complex unsteady flow physics.