• Title/Summary/Keyword: high safety

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Structural Safety Evaluation for Static Strength of Thin Plate RC Member with High Strength Concrete (고강도 콘크리트를 적용한 얇은 RC 판부재의 정적 강도 안전성 평가)

  • Hwang, Hoon-Hee;Park, Sung-Yong
    • Journal of the Korean Society of Safety
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    • v.32 no.5
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    • pp.69-75
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    • 2017
  • Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

Simulation and Damage Analysis of an Accidental Jet Fire in a High-Pressure Compressed Pump Shelter

  • Jang, Chang Bong;Choi, Sang-Won
    • Safety and Health at Work
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    • v.8 no.1
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    • pp.42-48
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    • 2017
  • Background: As one of the most frequently occurring accidents in a chemical plant, a fire accident may occur at any place where transfer or handling of combustible materials is routinely performed. Methods: In particular, a jet fire incident in a chemical plant operated under high pressure may bring severe damage. To review this event numerically, Computational Fluid Dynamics methodology was used to simulate a jet fire at a pipe of a compressor under high pressure. Results: For jet fire simulation, the Kemeleon FireEx Code was used, and results of this simulation showed that a structure and installations located within the shelter of a compressor received serious damage. Conclusion: The results confirmed that a jet fire may create a domino effect that could cause an accident aside from the secondary chemical accident.

Confidence Improvement of Disposal Safety by Development of a Safety Case for High-Level Radioactive Waste Disposal (고준위방사성폐기물 처분 Safety Case 개발을 통한 처분안전성 신뢰도 향상)

  • Baik, Min Hoon;Ko, Nak-Youl;Jeong, Jongtae;Kim, Kyung-Su
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.4
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    • pp.367-384
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    • 2016
  • Many countries have developed a safety case suitable to their own countries in order to improve the confidence of disposal safety in deep geological disposal of high-level radioactive waste as well as to develop a disposal program and obtain its license. This study introduces and summarizes the meaning, necessity, and development process of the safety case for radioactive waste disposal. The disposal safety is also discussed in various aspects of the safety case. In addition, the status of safety case development in the foreign countries is briefly introduced for Switzerland, Japan, the United States of America, Sweden, and Finland. The strategy for the safety case development that is being developed by KAERI is also briefly introduced. Based on the safety case, we analyze the efforts necessary to improve confidence in disposal safety for high-level radioactive waste. Considering domestic situations, we propose and discuss some implementing methods for the improvement of disposal safety, such as construction of a reliable information database, understanding of processes related to safety, reduction of uncertainties in safety assessment, communication with stakeholders, and ensuring justice and transparency. This study will contribute to the understanding of the safety case for deep geological disposal and to improving confidence in disposal safety through the development of the safety case in Korea for the disposal of high-level radioactive waste.

Consumer's Safety Consciousness and Safety Seeking Behavior (소비자의 안전의식과 안전추구행동)

  • 김성숙
    • Journal of the Korean Home Economics Association
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    • v.36 no.3
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    • pp.1-14
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    • 1998
  • This research focuses the safety problems for consumers with the viewpoint of behaviorism. Specially three issues are addressed: 1) Variables influencing the consumer's safety consciousness 2) The comparision of consumer's safety seeking behavior according to the product type 3) The relation of variables influencing the consumer's safety-seeking behaviors. In this paper, I deal with mainly the gas products and agricultural products and then observe the consumers' reaction for those two products concerning to the consumer's safety problem. For this purpose, I distributed the questionnaire to the residents I Seoul and suburban area of age between 20 and 60 years old. As a result, consumers put high values and concerns on general safety, but have quite negative concepts on society's safety problems generally. It was found that the consciousness on this problem was higher among those people who were reading journals for consumers, who have high education or high incomes, or who were unemployed house wives. In gas products, the level of consumer's safety seeking behavior and subareas were higher than in agricultural products. In the matter of the variables which affect the consumer's safety seeking behavior directly, those were safety consciousness variables and experience of reading journal for consumer in gas products, and safety consciousness vatiabls, consumer education experience, experience of injury, being employed and being married in agricultural products. Also as the result of path analysis, experience of reading journal for consumer, being employed, education and income level influenced indirectly the consumer safety seeking behavior.

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High Voltage Wiring System Evaluation Methode of FCEV (Fuel Cell Electric Vehicle) (수소연료전지 자동차용 고전압 배선 시스템 평가 기술 개발)

  • Lim, Ji-Seon;Lee, Jeong-Hun;Lee, Hyo-Jeong;Na, Joo-Ran
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.4
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    • pp.330-336
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    • 2012
  • FCEV uses 250 ~ 450 V instead of using 12 V battery. High voltage vehicle can cause electric shock, fire and explosion accident. Therefore, it has potential factors that can cause hazard of safety for users. United states of America and Europe legislate regulations such as ECE R100, FMVSS 305 for regulating electrical safety during driving or after collision. The company manufacturing high voltage components must do advanced R&D about Method for improving and confirming the safety of high voltage. We develop the specific hardware components of high voltage wiring system for the power train system and power supply system of Hyundai Motors FCEV. This paper shows test method of insulative performance for securing the electrical safety of high voltage components such as power cable, connectors and buss-bar, and proposals the guide line value for human safety of FCEV according to the test result of our development components.

Cases Study of Accidents in High Risk Organizations by System Dynamics (시스템 다이내믹스 기법을 활용한 고위험 조직 사고 사례 분석)

  • Oh, Youngmin;Ryu, Jin
    • Korean System Dynamics Review
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    • v.16 no.3
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    • pp.5-29
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    • 2015
  • The importance of the concept of safety culture has increased in the security of high-risk facility after Chernobyl accident in 1986. This paper elaborated the concept of safety culture and its main factors by Causal Loop Diagram. Due to the decline of safety culture, the occurrence of incidents and accidents require more and more corrective actions to the members of high-risk facilities and thereby increasing their workloads. Employees who must complete the task within the given time have to have time pressures and don't comply with the rules and procedures. Also, a schedule pressure is a big stress for employees, causing mistakes in precision work. In order to improve these problems, CLD of the safety culture in this paper suggests hiring more workers, re-allocation of given workloads and strengthen the learning, communication capabilities and safety leadership. In addition, the two real accident cases were analyzed to test the feasibility of the System Dynamic simulation model through the process of structuring the fault trees on the stationary black out accident in Kori unit 1 in South Korea and Kleen Energy power station explosion in US. The simulation results show that the various safety factors cause the serious accident combined with mechanical failure and safety culture will reduce the possibility of the accidents in these high-risk organizations. This simulation model can contribute to analyzing the impact of the organizational and human factors of safety culture and can provide the alternatives in high-risk facilities.

Running safety of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Structural Engineering and Mechanics
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    • v.76 no.2
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    • pp.207-222
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    • 2020
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train subjected to fluctuating crosswind. To ensure the safe operation in metro lines in mountain cities, running safety of the metro train over the high-pier bridge under crosswind is analyzed in this paper. Firstly, the dynamic model of the wind-train-bridge (WTB) system is built, in which the speed-up effect of crosswind is fully considered. On the basis of time domain analysis, the basic characteristics of the WTB system with high-pier are analyzed. Afterwards, the dynamic responses varies with train speed and wind speed are calculated, and the safety zone of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city is determined. The results indicate that, fluctuating crosswind triggers drastic vibration to the metro train and high-pier bridges, which in turn causes running instability of the train. For this reason, the corresponding safety zone for metro train running on the high-pier is proposed, and the metro traffic on the high-pier bridge should be closed as the mean wind speed of standard height reaches 9 m/s (15.6 m/s for the train).

Dynamic analysis of metro vehicle traveling on a high-pier viaduct under crosswind in Chongqing

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Wind and Structures
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    • v.29 no.5
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    • pp.299-312
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    • 2019
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train under crosswind. Compared with the conditions of no-wind, crosswind triggers severer vibration of the dynamic system; compared with the short-pier viaduct, the high-pier viaduct has worse stability under crosswind. For these reasons, the running safety of the metro vehicle traveling on a high-pier viaduct under crosswind is analyzed to ensure the safe operation in metro lines in mountain cities. In this paper, a dynamic model of the metro vehicle-track-bridge system under crosswind is established, in which crosswind loads model considering the condition of wind zone are built. After that, the evaluation indices and the calculation parameters have been selected, moreover, the basic characteristics of the dynamic system with high-pier under crosswind are analyzed. On this basis, the response varies with vehicle speed and wind speed are calculated, then the corresponding safety zone is determined. The results indicate that, crosswind triggers drastic vibration to the metro vehicle and high-pier viaduct, which in turn causes running instability of the vehicle. The corresponding safety zone for metro vehicle traveling on the high-pier is proposed, and the metro traffic on the high-pier bridge under crosswind should not exceed the corresponding limited vehicle speed to ensure the running safety.

A Study on the Safety Management of High Pressure Underground Pipeline in Industrial Estate (산업단지 고압매설배관 안전관리 향상방안 연구)

  • Choi, Hyun-Woog;Lee, Dong-Min;Kim, jin-jun
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.100-106
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    • 2018
  • pressure buried pipes in domestic industrial estate have many long-term use pipes, Toxic, flammable, Inflammable, etc. as well as a variety of toxic chemicals are embedded in a complex be buried, A high level of safety management is required as it can damage other pipes installed nearby in the event of accidents such as various external interference. Therefore, in this study, the safety management practices of high-pressure gas distribution and urban gas distribution are utilized to derive efficient safety management methods for high-pressure gas installation piping through in-depth comparative analysis.

Analysis on Attitude and Education Need for Food Safety of High School Students in Gyeongbuk Province (경북지역 고등학생의 식품 안전성에 대한 태도 및 교육요구도 분석)

  • Kim, Eun-Jung;Kim, Hyo-Chung;Kim, Mee-Ra
    • Korean Journal of Human Ecology
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    • v.18 no.6
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    • pp.1323-1336
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    • 2009
  • This study examined the attitude and education need for food safety of high school students. Data were collected from 297 high school students in Gyeongbuk province through a self-administered questionnaire on December, 2008. Frequency, t tests, one-way analysis of variance, Duncan's multiple range tests, and chi-square tests were conducted using SPSS V. 14.0. Many respondents answered that the foods produced and distributed in Korea were not safe enough. Over a third of the respondents replied that the produced and distributed foods were not safe because of unsanitary food processing. They pointed out food additives threatened food safety the most, which was followed by heavy metal contamination, and endocrine disruptors. Most respondents mentioned difficulties in acquiring information concerning food safety, and obtained information from the media, such as TV and radio. The respondents required a high level of education regarding food safety, and preferred movie clips and broadcasting media the most. Finally, they pointed out food-related government organizations to be the most efficient educational institution for food safety.