• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.346-357
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• 2023

The purpose of this study is to suggest improvement plans for prevention regulations by reflecting the toxicity, fire and explosion effects of hazardous materials factories and surrounding areas using an off-site consequence assessment program. Regarding the effects of the hydrogen cyanide leak accident, which is the 1st petroleum of the 4th class flammable liquid, Areal Locations of Hazardous Atmospheres (ALOHA) program was used to compare and analyze the extent of damage effects for toxicity, overpressure, and radiation. As a result, the toxicity was analyzed to exceed 5km in the area with Acute exposure guideline level (AEGL)-2 concentration or higher, the overpressure was 103m in the range of 1 psi or more, and the radiant heat was analyzed to be 724m in the range of 2kw/m² or more. Toxicity and radiation affected the area outside the hazardous material storage area, but the overpressure was limited to the inside of the hazardous material storage area. Therefore, we propose to improve the safety management of hazardous materials by conducting a risk assessment for hazardous materials and reflecting the results in internal and external emergency response plans to prepare prevention regulations.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.62-67
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• 2018

It is very important to classify explosion hazardous area in order to prevent an accident explosion. In order to prevent such a explosion, the Industrial Safety and Health Standards Rules stipulates the establishment and management of explosion hazards in accordance with the criteria set by the Korean Industrial Standards. This study has investigated the range of the explosion hazardous area according to various hole sizes, pressures, vapor densities, and wind velocities in the outdoor flammable liquid tank using KS C IEC-60079-10-1 $2^{nd}$ Ed.(=IEC CODE) and PHAST. The results show that the explosion hazardous areas by IEC CODE have circle shapes. However, the areas by PHAST show ellipse shapes. The different of the explosion hazardous areas increases with the increase of wind velocity.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.1
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• pp.29-34
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• 2019

Safety of hydrogen handling facilities is needed as supply of hydrogen cars has been expanded recently. In this study, the adequacy of safety regulations of hydrogen handling facilities and the risk of damage with hydrogen leakage were studied. The range of explosion hazard location of the hydrogen filling plant was investigated using the computational fluid dynamics (CFD) method, Explosive hazardous area is influenced by leakage type, hole size and sectional area. When the conditions of KS standard are applied, range explosive hazardous area is expanded 7.05 m, maximum. It is about 7 times larger than exceptional standard of hydrogen station. Meanwhile, distance from leakage point to 25% LEL of hydrogen is investigated 1.6 m. Considering the shape of charging hose, regulation of hydrogen station is appropriate.

• Journal of the Korean Institute of Gas
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• v.22 no.4
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• pp.13-26
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• 2018

Currently, local regulations, such as KS Code, do not clearly specify how to calculate the range of hazardous area, so the dispersion modeling program should be used to select dispersion. The purpose of this study is to present a methodology of determining the range of hazardous area which is simpler and more reasonable than modelling by using representative materials and process conditions. Based on domestic and overseas regulations that are currently in effect, variables affecting distance to LFL(Lower Flammable Limit) were selected. A total of 16 flammable substances were modelled for substance variables, process conditions variables, and weather conditions variables, and the statistical analysis selected the variables that affect them. Using the selected variables, a three-step classification method was prepared to select the range of locations subject to explosion hazard.

• Korean Journal of Community Nutrition
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• v.3 no.3
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• pp.454-465
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• 1998

This study was to investigate the recognition level of food contamination with residual pesticides and hazardous heavy metals from 365 male and female adults in Taejon area using questionnaires. Among the recognizing level of residual pesticides in overall foods, 69.1% were 'serious', 25.6% were 'average' and 5.3% were 'not serious'. Over 94.7% of the subjects recognized residual pesticides pollution infoods. for hazardous heavy metals in food, 47.8% responsed as 'serious', 40.5% as 'average' and 11.8 as ' not serious' . Over 88.3% of the subjects recognized contaminated pesticides seriously in fruits, 72.1% in vegetables and 51.7% in cereals, whereas 55.7% of the subjects recognized hazardous heavy metal contamination seriously in fruits, 53.4% in vegetables, 40.8% in fishes and shellfishes and 35.0% in seaweeds. The subjects recognized residual pesticides contamination more seriously in overall foods, cereal, potatoes and starches, bean, vegetables and fruits, whereas hazardous heavy metal contamination was recognized more seriously in fishes and shellfishes, and seaweeds food groups. Comparisons were shown based on individuial's occupation. Farmer, forester, iner and fisher showed the lowest recognizing level of food contamination in most food groups. The mean score of the dietary effect by mass media's information on food contamination from residual pesticides and hazardous heavy metals were 3.51±0.96 out of 5 points. By Duncan's multiple range test, sex, age, marriage, food cost per month, concerns about health and nutrition knowledge showed significant differences in the mean effect score at p<0.05. According to a pesticides contamination in several food groups were affected by food cost per month, mass media's information on food contamination, health status, and concerns about health, But a recognition level of hazardous heavy metals in food were affected by income and, food cost per month mass media's information on food contamination, health status, concern about health and nutrition knowledge. People who need to take extreme precautions of food contamination were in order of producers, government officials, homemakers, the consumer's association and consumers.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.21-29
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• 2018

In many companies handling flammable liquids, explosion-proof electrical equipment have been installed according to the Korean Industrial Standards (KS C IEC 60079-10-1). In these standards, hazardous area for explosive gas atmospheres has to be classified by the evaluation of the evaporation rate of flammable liquid leakage. The evaporation rate is an important factor to determine the zones classification and hazardous area distance. However, there is no systematic method or rule for the estimation of evaporation rate in these standards and the first principle equations of a evaporation rate are very difficult. Thus, it is really hard for industrial workplaces to employ these equations. Thus, this problem can trigger inaccurate results for evaluating evaporation range. In this study, empirical models for estimating an evaporation rate of flammable liquid have been developed to tackle this problem. Throughout the sensitivity analysis of the first principle equations, it can be found that main factors for the evaporation rate are wind speed and temperature and empirical models have to be nonlinear. Polynomial regression is employed to build empirical models. Methanol, benzene, para-xylene and toluene are selected as case studies to verify the accuracy of empirical models.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.147-155
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• 2015

In this paper, we consider a mobile sensor network for monitoring a polluted area where human beings cannot access. Due to the limited sensing range of individual unmanned vehicles, they need to cooperate to achieve an effective sensing coverage and move to a more polluted region. In order to address the limitations of sensing and communication ranges, we propose a hazardous substance monitoring network based on virtual force algorithms, and develop a testbed. In the considered monitoring network, each unmanned vehicle achieves an optimal coverage and move to the highest interest area based on neighboring nodes sensing values and locations. By using experiments based on the developed testbed, we show that the proposed monitoring network can autonomously move toward a more polluted area and obtain a high weighted coverage.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.89-95
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• 2017

A rapid, sensitive analytical method for glucuronolactone in beverages was developed and validated using hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HILIC-ESI-MS/MS). To determine the optimum analytical conditions for glucuronolactone, three different kinds of HILIC columns and two mobile phases with different pH values were examined. An amide-bonded stationary phase with a pH 9 acetonitrile-rich mobile phase was the best condition in terms of column retention, ESI-MS/MS response area, and signal-to-noise ratio. After extraction, glucuronolactone was separated through the HILIC amide column and detected by negative ESI-MS/MS in selected reaction monitoring (SRM) mode. Nine energy drinks sold in Korea were spiked with glucuronolactone at a concentration of 5 ng/mL; the Monster $Energy^{TM}$ sample showed the smallest peak area and its signal-to-noise ratio was used for method validation. Good linearity was obtained in the concentration range from 20 to 1500 ng/mL with a correlation coefficient > 0.998. The developed method had a limit of detection (LOD) of 6 ng/mL and a limit of quantitation (LOQ) of 20 ng/mL. The recovery of this method at concentration of 20, 100, 500, and 1000 ng/mL was 96.3%-99.2% with relative standard deviations (RSD) of 1.6%-14.0%. A reproducibility precision assessment at concentration of 100 and 500 ng/mL was carried out among three laboratories. The recovery of that evaluation was 95.1%-102.3% with RSD of 2.7%-7.0%. An analysis of variance indicated that there was no difference between the recovery results of the three laboratories at the 5% significance level. The validated method is applicable to inspecting beverages adulterated with glucuronolactone in Korea.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.3
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• pp.262-276
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• 2016

Generally, the Safety Integrity Level (SIL) of a subsea Blowout Preventer (BOP) is evaluated by determining the Probability of Failure on Demand (PFD), a low demand mode evaluation indicator. However, some SIL results are above the PFD's effective area despite the subsea BOP's demand rate being within the PFD's effective range. Determining a Hazardous Event Frequency (HEF) that can cover all demand rates could be useful when establishing the effective BOP SIL. This study focused on subsea BOP functions that follow guideline 070 of the Norwegian Oil and Gas. Events that control subsea well kicks are defined. The HEF of each BOP function is analyzed and compared with the PFD by investigating the frequency for each event and the demand rate for the components. In addition, risk control options related to PFD and HEF improvements are compared, and the effectiveness of HEF as a SIL verification for subsea BOP is assessed.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.39-46
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• 2018

최근 전자제품 생산업체에서 EPS를 직접생산하게 되면서 EPS 공정이 증가하고 있다. EPS에는 펜탄이 포함되어 있으며, 펜탄은 하이브리드 혼합물로 구분할 수 있어 높은 화재폭발의 위험성을 가지고 있다. 각 공정별 펜탄의 누출률은 발포기, 사일로실, 저장실 순이나 발포기의 경우 일반적으로 밀폐되어 있으므로 사일로 실이 가장 화재폭발 위험성이 높다고 판단하였다. 사일로실의 누출률 중 70%는 사일로 상단을 통해 누출되며, 사일로 상단을 통해 누출되는 펜탄의 거동을 분석하여 사일로실 위험성 완화대책을 수립하였다. 1. 폭발위험구역 2종으로 관리, 2. 사일로상단 50cm이내 환기설비 설치 또는 Push-Pull 구조의 환기설비설치, 3. 사일로 하단 1.4m이내에 가스감지기 설치, 4. 60%이상의 습도유지