• Title/Summary/Keyword: Accident concentration

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Technical study on quantitative analysis of the toxic gas concerning the combustion property of interior materials of railway car (철도차량용 내장 재료의 연소특성을 고려한 유해가스 정량분석 기법연구)

  • Park, Ji-Young;Lee, Cheul-Kyu;Lee, Duck-Hee;Jung, Woo-Sung;Chung, Hoe-Il
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1114-1118
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    • 2008
  • In previous fire accident of railway car, the fatality was relatively high by toxic gas poisoning cause of closed space. So the necessity of quantifying toxic gas in combustion gas was recognized and then, FT-IR spectroscopy was introduced for real-time analysis of mixed gases and stimulated analysis of the concentration of several gases. Thus, in this study, absorption bands using FT-IR were obtained by each component of combustion gases for interior materials of railway car such as flooring materials and moquette seat. And then the sample spectra were compared with the spectra of NO, $NO_2$, $SO_2$ reference gases, we could obtain some identical peaks of them.

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Evaluation of Thermal Hazard in Neutralization Process of Pigment Plant by Multimax Reactor System (Multimax Reactor System을 이용한 안료제조시 중화공정의 열적위험성 평가)

  • Lee, Keun-Won;Han, In-Soo
    • Journal of the Korean Society of Safety
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    • v.23 no.6
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    • pp.91-99
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    • 2008
  • The identification of thermal hazards associated with a process such as heats of reaction and understanding of thermodynamics before any large scale operations are undertaken. The evaluation of thermal behavior with operating conditions such as a reaction temperature, stirrer speed and reactants concentration in neutralization process of pigment plant are described. The experiments were performed by a sort of calorimetry with multimax reactor system The aim of the study was to evaluate the results of heat of reaction in terms of safety reliability to be practical applications. It suggested that we be proposed safe operating conditions and securities for accident prevention on reactor explosion through this study.

A study on the pressure behaviour during the rupture by gas explosion

  • Kim, Min-Kyu;Oh, Kyu-Hyung;Kim, Hong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.275-281
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    • 1997
  • The destruction by accident is affected by the blast of explosion. However, there are few of research on the external effect of vented gas explosions. Therefore it is necessary to study the effect of vented explosion. This study aims to find the characteristics of gas explosion, and the effect of vented gas explosion. Using an explosion chamber, we obtained a LPG explosion characteristics according to the vent size and concentration. The result of experiment showed that the explosion pressure effect to external space was much stronger than inner space during the course of a gas explosion. And the external pressure become higher in explosion pressure as the vent diameter become smaller.

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A Comparison Study on the Concentration of Total Welding Fume and Respirable Particulate Mass for Welding Workers of a Shipbuilding (조선소 용접작업자들의 총용접흄과 호흡성분진농도 비교연구)

  • Kang, Yong-Seon;Sim, Sang-Hyo;Lee, Song-Kwon;Bin, Sung-Oh;Choi, Eun-Seok
    • Journal of Environmental Health Sciences
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    • v.33 no.4
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    • pp.276-282
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    • 2007
  • The purpose of this study is to assess the accurate state of the following: total welding fumes versus welding fumes in the air, respirable particulate mass, and exposure of dockyard welders to heavy metals. In addition, this study provides basic data for proposing improvements to create efficient and appropriate welding environments and to prevent occupational diseases. The subjects of this study were 94 laborers who worked at the block construction sites of large-scale dockyards located in Gyeongnam Province from March 2005 to June 2005. In order to collect samples on total welding fumes in the air and respirable particulate mass from the welders, Methods 0500 and 0600, established by the National Institute for Occupational Safety and Health (NIOSH), were used. The metals within the welding fumes were also analyzed using Inductively Coupled Plasma (ICP) under Method 7300 from NIOSH. The results of this research are summarized below. The geometric mean concentration of total welding fumes and that of respirable particulate mass were $4.11\;mg/m^3\;and\;3.53\;mg/m^3$, respectively. As a result of comparing the two measurement methods, there were significant differences (p<0.05) between the two groups for Ca, Cu, Cr, and Ni; however, there were no differences in Fe, Mg, Zn, Mg, Pb, and Cd. As a result of the analysis, the correlation between Mn and the concentration of heavy metals in the total welding fumes and respirable particulate mass was found to be -0.29, a significant negative correlation. The correlation between other heavy metals, however, was low. Finally, in the same total welding fumes, the correlation of Fe and Mg was high.

$^{137}Cs$ Concentrations in Cultivated Soils of Korea (우리나라 경작지 토양중 $^{137}Cs$ 농도)

  • Choi, Yong-Ho;Lim, Kwang-Muk;Lee, Myung-Ho;Park, Hyo-Guk;Lee, Won-Yun
    • Journal of Radiation Protection and Research
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    • v.24 no.2
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    • pp.55-63
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    • 1999
  • For understanding the radiation environment in the land of Korea and acquiring baseline data to be referred to at the time of a nuclear accident, cultivated soils in the $0{\sim}15cm$ layer were sampled at 33 sites scattered all over the country and $^{137}Cs$ concentrations were measured by $\gamma$-spectrometry. The soil $^{137}Cs$ concentrations were in the range of $0.7{\sim}17.7$ Bq/kg-dry in the paddy field and $1.2{\sim}27.8$ Bq/kg-dry in the upland field, The means were 6.9 Bq/kg-dry and 9.9 Bq/kg-dry, respectively. In the paddy field, the soil $^{137}Cs$ concentration was positively correlated to the organic matter content and negatively correlated to the clay content. In the upland field, it was positively correlated to the cation exchange capacity. It was revealed that soil organic matter play an important role in the change of soil $^{137}Cs$ concentration.

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A Study on integrated water management system based on Web maps

  • Choi, Ho Sung;Jung, Jin Young;Park, Koo Rack
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.8
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    • pp.57-64
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    • 2016
  • Initial prevention activities and rapid propagation conditions is the most important to prevent diffusion of water pollution. If water pollutants flow into streams river or main stresm located in environmental conservation area or water intake facilities, we must predict immediately arrival time and the diffusion concentration to the proactive. National Institute of Environmental Research developed water pollution incident response prediction system linking dam and movable weir. the system is mathematical model which is updated daily. Therefore it can quickly predict the arrival time and the diffusion concentration when there are accident of oil spills and hazardous chemicals. Also we equipped with mathematical model and toxicity model of EFDC(Environmental Fluid Dynamics Code) to calculate the arrival time and the diffusion concentration. However these systems offer the services of an offline manner than real-time control services. we have ensured the reliability of data collection and have developed a real-time water quality measurement data transmission device by using the data linkage utilizing a mode bus communication and a commercial SCADA system, in particular, we implemented to be able to do real-time water quality prediction through information infrastructure of the water quality integrated management business created by utilizing the construction of the real-time prediction system that utilizes the data collected, the Open map, the visual representation using charts API and development of integrated management system development based on web maps.

Development for Analysis Service of Crowd Density in CCTV Video using YOLOv4 (YOLOv4를 이용한 CCTV 영상 내 군중 밀집도 분석 서비스 개발)

  • Seung-Yeon Hwang;Jeong-Joon Kim
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.3
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    • pp.177-182
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    • 2024
  • In this paper, the purpose of this paper is to predict and prevent the risk of crowd concentration in advance for possible future crowd accidents based on the Itaewon crush accident in Korea on October 29, 2022. In the case of a single CCTV, the administrator can determine the current situation in real time, but since the screen cannot be seen throughout the day, objects are detected using YOLOv4, which learns images taken with CCTV angle, and safety accidents due to crowd concentration are prevented by notification when the number of clusters exceeds. The reason for using the YOLO v4 model is that it improves with higher accuracy and faster speed than the previous YOLO model, making object detection techniques easier. This service will go through the process of testing with CCTV image data registered on the AI-Hub site. Currently, CCTVs have increased exponentially in Korea, and if they are applied to actual CCTVs, it is expected that various accidents, including accidents caused by crowd concentration in the future, can be prevented.

Quantitative Risk Analysis of a Pervaporation Process for Concentrating Hydrogen Peroxide (과산화수소 농축을 위한 투과증발공정의 정량적 위험성 분석)

  • Jung, Ho Jin;Yoon, Ik Keun;Choi, Soo Hyoung
    • Korean Chemical Engineering Research
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    • v.52 no.6
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    • pp.750-754
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    • 2014
  • Quantitative risk analysis has been performed for a pervaporation process for production of high test peroxide. Potential main accidents are explosion and fire caused by a decomposition reaction. As the target process has a laboratory scale, the consequence is considered to belong to Category 3. An event tree has been developed as a model for occurrence of a decomposition reaction in the target process. The probability functions of the accident causes have been established based on the frequency data of similar events. Using the constructed model, the failure rate has been calculated. The result indicates that additional safety devices are required in order to achieve an acceptable risk level, i.e. an accident frequency less than $10^{-4}/yr$. Therefore, a layer of protection analysis has been applied. As a result, it is suggested to introduce inherently safer design to avoid catalytic reaction, a safety instrumented function to prevent overheating, and a relief system that prevents explosion even if a decomposition reaction occurs. The proposed method is expected to contribute to developing safety management systems for various chemical processes including concentration of hydrogen peroxide.

Health Effect Assessment on Cleanup Workers of an Oil Spill in Yeosu (여수 유류유출사고 방제작업자의 건강영향평가)

  • Kim, Geunbae;Kang, Tack Shin;Yoon, Mira;Jo, Hyejung;Joo, Youngkyung;Yu, Seung Do;Lee, Bo Eun
    • Journal of Environmental Health Sciences
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    • v.42 no.6
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    • pp.385-395
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    • 2016
  • Objectives: The aim of this study was to assess exposure to VOCs and PAHs and the health effects on volunteers who participated in an oil spill cleanup in Yeosu. Methods: Atmospheric VOCs were evaluated in the vicinity of the accident site and questionnaire surveys were conducted to identify personal characteristics and acute health symptoms of clean-up workers seven days after the accident. The levels of metabolites of VOCs (t,t-MA, HA, PGA, MA, MHA) and PAHs (2-NAP, 1-OHP, 2-HF, 1-HPH), oxidative stress markers (TABARS, 8-OHdG) in the urine of workers were analyzed. Their correlation was determined by multiple regression analysis with SAS ver. 9.4. Results: Although the concentration of atmospheric VOCs in the residential areas were low at the time of survey, the levels of VOCs and PAHs metabolites in clean-up workers were higher than those in the control group after clean-up activities. The levels of urinary VOC and PAH metabolites were significantly increased after clean-up compared to those measured before participation. The thiobarbituric acid reactive substance (TBARS) concentrations were also increased and showed significant correlations with those of metabolites of benzene. Conclusion: This study shows that oil spill clean-up activities affect exposure to VOCs and PAHs and the health of clean-up workers. The results suggest the need for check-ups of participants in oil spill cleaning work.

A Study on Workers' Risk-Aware Smart Bands System in Explosive Areas (폭발위험지역 근로자 위험 인지형 스마트밴드시스템에 대한 연구)

  • Lee, Byong-Kwon
    • Journal of Internet of Things and Convergence
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    • v.5 no.2
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    • pp.73-79
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    • 2019
  • Research is underway on services and systems that provide real-time alerts for suffocating gases and potentially explosive materials, but currently smart bend type services are lacking. This study supports real-time identification of explosion hazards due to static electricity in the workplace and immediate elimination of accident occurrence factors, real-time monitoring of worker status and workplace hazards (oxygen, hazardous chemical concentration), and immediate warning and data in case of danger. We propose a method of establishing an accident prevention system through analysis. In this way, various accidents that may occur in industrial sites are monitored using IoT-based intelligent sensor nodes, wireless network technology, data processing middleware, and integrated control system, and real-time risk information at the industrial sites is prevented and accidents are prevented. By supporting a safe working environment, the company can significantly reduce costs compared to post-procurement costs.