• Title/Summary/Keyword: reliability and safety

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Selection of Influencing Factors for Human Reliability Analysis of Accident Management Tasks in Nuclear Power Plants (원자력 발전소 사고관리 직무의 인간신뢰도분석을 위한 수행영향인자의 선정)

  • Kim, Jae-Hwan;Jeong, Won-Dae
    • Journal of the Ergonomics Society of Korea
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    • v.20 no.2
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    • pp.1-28
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    • 2001
  • This paper deals with the selection of the important Influencing Factors (IFs) under accident management situations in nuclear power plants for use in the assessment of human errors. In order to achieve this goal, we collected two types of IF taxonomies, one is the full set IF list mainly developed for human error analysis. and the other is the IFs for human reliability analysis (HRA) in probabilistic safety assessment (PSA). Five sets of IF taxonomy among the full set IF list and ten sets of IF taxonomy among HRA methodologies were collected in the study. From the review and analysis of BRA IFs, we could obtain some insights for the selection of HRA IFs. By considering the situational characteristics of the accident management domain, candidate IFs are chosen. Finally, those IFs are structured hierarchically to be appropriate for the use in the assessment of human error under accident management situation. Three nuclear accidents such as TMI. Chernobyl and JCO were analysed to validate the proposed taxonomy.

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An efficient vibration control strategy for reliability enhancement of HAWT blade

  • Sajeer, M. Mohamed;Chakraborty, Arunasis;Das, Sourav
    • Smart Structures and Systems
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    • v.26 no.6
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    • pp.703-720
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    • 2020
  • This paper investigates the safety of the wind turbine blade against excessive deformation. For this purpose, the performance of the blade in the along-wind direction is improved by longitudinal stiffener made of shape memory alloy. The rationale behind the selection of this smart material is due to its ability to offer excellent thermo-mechanical behaviour at low strain. Here, Liang-Roger model is adopted for vibration control, and the super-elastic effects are utilised for blade stiffening. Turbulent wind fields are generated at the hub height using TurbSim and the corresponding loads are evaluated using blade element momentum theory. An efficient switching algorithm is developed along with performance curves that enable the designer to select an optimal mode of heating depending upon the operational scenario. Numerical results presented in this paper clearly demonstrate the performance envelope of the proposed stiffener and its influence on the reliability of the blade.

Reliability-Based Topology Optimization Based on Bidirectional Evolutionary Structural Optimization (양방향 진화적 구조최적화를 이용한 신뢰성기반 위상최적화)

  • Yu, Jin-Shik;Kim, Sang-Rak;Park, Jae-Yong;Han, Seog-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.4
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    • pp.529-538
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    • 2010
  • This paper presents a reliability-based topology optimization (RBTO) based on bidirectional evolutionary structural optimization (BESO). In design of a structure, uncertain conditions such as material property, operational load and dimensional variation should be considered. Deterministic topology optimization (DTO) is performed without considering the uncertainties related to the design variables. However, the RBTO can consider the uncertainty variables because it can deal with the probabilistic constraints. The reliability index approach (RIA) and the performance measure approach (PMA) are adopted to evaluate the probabilistic constraints in this study. In order to apply the BESO to the RBTO, sensitivity number for each element is defined as the change in the reliability index of the structure due to removal of each element. Smoothing scheme is also used to eliminate checkerboard patterns in topology optimization. The limit state indicates the margin of safety between the resistance (constraints) and the load of structures. The limit State function expresses to evaluate reliability index from finite element analysis. Numerical examples are presented to compare each optimal topology obtained from RBTO and DTO each other. It is verified that the RBTO based on BESO can be effectively performed from the results.

A Study to Develop a Practical Probabilistic Slope Stability Analysis Method (실용적인 확률론적 사면안정 해석 기법 개발)

  • 김형배;이승호
    • Journal of the Korean Geotechnical Society
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    • v.18 no.5
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    • pp.271-280
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    • 2002
  • A probabilistic approach to identify the effects of uncertainties of soil strength parameters on searching a critical slip surface with the lowest reliability is introduced. In general construction field, it is impossible for the engineer to always gather a variety of statistical information of soil strength parameters for which lots of laboratory and in-situ soil testing are required and to use it with enough statistical knowledge. Thus, in order that the engineer may easily understand the probabilistic concept for the slope stability analysis, this study proposes a combined procedure to incorporate the engineering probabilistic tools into the existing deterministic slope stability analysis methods. Using UTEXAS 3, a slope stability analysis computer program developed by U.S. Army Corps of Engineers (U.S. COE), this study provides the results of this probabilistic slope stability analysis in terms of probability of failure or reliability index. This probabilistic method f3r slope stability analysis appears to yield more comprehensive results of slope reliability than does existing deterministic methods with safety factors alone.

Visualization of women's safety facility index based on public data analysis: Focusing on Seoul (공공데이터 분석 기반 여성안전 시설지수 시각화: 서울시 중심으로)

  • Kim, Hyeong-Gyun
    • Journal of Digital Convergence
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    • v.19 no.4
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    • pp.19-24
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    • 2021
  • In this paper, an index of women's safety facilities was created and visualized using public data related to Seoul. CPTED, the women's safety facilities index was created by collecting and analyzing eight data related to the local women's safety index and five major crime victims of women. As a result of the correlation analysis between the factors of the female safety facility index and the number of female crime victims, three data were selected as the main factors, "CCTV," "street lamps," and "female security guardians", which were found to be meaningful at the 95% level of reliability. The distinction women's safety facility index was calculated by weighting the correlation coefficient between the main factors for calculating the women's safety facility index, and visualized using Python's Follium library.

The Effects of Logistics Technology Acceptance in the Fourth Industrial Revolution on Logistics Safety Performance: The Moderated Mediating Effect of Logistics Safety Behavior through Safety Culture

  • Kim, Young-Min
    • Journal of Korea Trade
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    • v.26 no.1
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    • pp.57-80
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    • 2022
  • Purpose - This study aims to examine the relationships between the acceptance of the 4th industrial revolution logistics technology, logistics safety behavior, and logistics safety performance, as well as the moderated mediating effects of logistics safety behavior through safety culture in Korea. Design/methodology - Research models and hypotheses were established based on prior research related to the 4th industrial revolution logistics technology, logistics safety, and logistics performance. The survey was conducted on the employees of logistics companies, and reliability analysis, confirmatory factor analysis, discriminant validity analysis, structural equation model analysis, and mediating effect analysis were performed. In addition, the moderated mediating effect analysis applying SPSS Process Model No. 7 was conducted. Findings - Usefulness and sociality of the acceptance of the 4th industrial revolution logistics technology had a significant effect on logistics safety behavior. Ease of use, sociality, and efficiency had meaningful effect on logistics safety performance. And in the relationships between the acceptance of logistics technology and logistics safety performance, logistics safety behavior had a significant mediating effect. But the moderated mediating effect of safety behavior through safety culture was not significant. Logistics companies can improve logistics safety performance through the utilization of new logistics technologies such as intelligent logistics robots, autonomous driving technology, and artificial intelligence, etc. Originality/value - This is the first study to analyze the relationships between the acceptance of logistics technology in the 4th industrial revolution and logistics safety. In addition, previous studies analyzed mediating effects or moderating effects, but this is the first study to identify the moderated mediating effects of safety behavior through safety culture. In other words, it has originality in terms of research methodology.

The Possibilities to use the Non- Destructive Testing on Diagnosing Wears of Wagon Chassis

  • Munkhtsetseg, T.
    • International Journal of Railway
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    • v.5 no.1
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    • pp.22-28
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    • 2012
  • This report is devoted to the problems of Mongolian Railway Transportation Safety such as high length of wagon service life, defects due to the more factors of exploitation, idle time, increase of faults, poor condition of repairing shops and more hand and mechanical operations and these conditions are quite difficult to meet the safety and reliability of increasing transportation from day to day. The paper discusses that the most optimum solution is diagnosing before occurring wear, breakdown, and defects on the basis of studying characteristics of structural material breakdown, residual methods of voltage, effects of material hardness and linear defects of a crystal net and the reform of machines is very important to implement it. It focuses the structures, characteristics of the material transportation and tests and analyses of the wagon cart which has to meet the traffic safety of wagons and slow and soft movement. The study is done on the wagon chassis which has to meet the traffic safety of luggage wagons.

Safety Culture Assessment in Petrochemical Industry: A Comparative Study of Two Algerian Plants

  • Boughaba, Assia;Hassane, Chabane;Roukia, Ouddai
    • Safety and Health at Work
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    • v.5 no.2
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    • pp.60-65
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    • 2014
  • Background: To elucidate the relationship between safety culture maturity and safety performance of a particular company. Methods: To identify the factors that contribute to a safety culture, a survey questionnaire was created based mainly on the studies of $Fern{\acute{a}}ndez-Mu{\tilde{n}}iz$ et al. The survey was randomly distributed to 1000 employees of two oil companies and realized a rate of valid answer of 51%. Minitab 16 software was used and diverse tests, including the descriptive statistical analysis, factor analysis, reliability analysis, mean analysis, and correlation, were used for the analysis of data. Ten factors were extracted using the analysis of factor to represent safety culture and safety performance. Results: The results of this study showed that the managers' commitment, training, incentives, communication, and employee involvement are the priority domains on which it is necessary to stress the effort of improvement, where they had all the descriptive average values lower than 3.0 at the level of Company B. Furthermore, the results also showed that the safety culture influences the safety performance of the company. Therefore, Company A with a good safety culture (the descriptive average values more than 4.0), is more successful than Company B in terms of accident rates. Conclusion: The comparison between the two petrochemical plants of the group Sonatrach confirms these results in which Company A, the managers of which are English and Norwegian, distinguishes itself by the maturity of their safety culture has significantly higher evaluations than the company B, who is constituted of Algerian staff, in terms of safety management practices and safety performance.

A Study on the Exposure Assessment of Extremely Low Frequency Magnetic Fields (극저주파 자계의 노출 평가에 대한 연구)

  • Kim, Eung-Sik;Kim, Myeong-Hun;Min, Suk-Won
    • Journal of the Korean Society of Safety
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    • v.32 no.1
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    • pp.33-40
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    • 2017
  • This paper addresses the assessment methods used to evaluate the magnetic exposure of a human to ELF EMF (Extremely Low Frequency Electromagnetic Field) which is caused by the process of power delivery from 60 Hz commercial power. These days the main concern is primarily focused on the magnetic field. For the exposure assessment, both numerical studies and laboratory experiments were studied and the results of the two compared for methodological suitability. The numerical analyses employ the Impedance Method (IM), Boundary Element Method (BEM), and Finite Element Method (FEM) and the laboratory experiments used various human phantom models made with conductivities congruent to human organs and then exposed to uniform/non-uniform magnetic fields to produce eddy currents. Under these conditions a number of examples have been evaluated and the reliability assessed to present the pros and cons of each methodology.

The inspection and seismic design method of electrical facility instated in the building (건축물에 시설되는 수변전설비 내진설계 및 검사 방법에 관한 연구)

  • Kim, Gi-Hyun;Lee, Sang-Ick;Kang, Min-Hee;Bae, Suk-Myong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.05a
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    • pp.332-335
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    • 2009
  • Incase of not considered seismic design at transformer vault which is made of many informant electrical facility, facility is damaged, electrical fire breaks out and second damage is able to break out at generating earthquake. But seismic design yet is not applied to at transformer vault in the country. Regard to seismic design method of electrical facility installed in the building internal, we present the seismic design of electrical facility using "Building construction design standard" in internal and "Manual of seismic design and construction for Building Electrical facility" in japan. This paper will be used detail seismic design of pipe and facility. reliability inspection plan for seismic design and construction of electrical facility

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