• Title/Summary/Keyword: Critical Incident

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Theoretical Model for Accident Prevention Based on Root Cause Analysis With Graph Theory

  • Molan, Gregor;Molan, Marija
    • Safety and Health at Work
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    • v.12 no.1
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    • pp.42-50
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    • 2021
  • Introduction: Despite huge investments in new technology and transportation infrastructure, terrible accidents still remain a reality of traffic. Methods: Severe traffic accidents were analyzed from four prevailing modes of today's transportations: sea, air, railway, and road. Main root causes of all four accidents were defined with implementation of the approach, based on Flanagan's critical incident technique. In accordance with Molan's Availability Humanization model (AH model), possible preventive or humanization interventions were defined with the focus on technology, environment, organization, and human factors. Results: According to our analyses, there are significant similarities between accidents. Root causes of accidents, human behavioral patterns, and possible humanization measures were presented with rooted graphs. It is possible to create a generalized model graph, which is similar to rooted graphs, for identification of possible humanization measures, intended to prevent similar accidents in the future. Majority of proposed humanization interventions are focused on organization. Organizational interventions are effective in assurance of adequate and safe behavior. Conclusions: Formalization of root cause analysis with rooted graphs in a model offers possibility for implementation of presented methods in analysis of particular events. Implementation of proposed humanization measures in a particular analyzed situation is the basis for creation of safety culture.

A Study on The Relationship between Human Errors Caused by Psychological Stress of Helicopter Pilots and Conditions of Potential Accidents and Incidents (국내 헬리콥터 조종사 정신적 스트레스에 의한 인적 오류와 잠재적 사고 및 준사고 조건 간 관계에 관한 연구)

  • Kyungjin Yum;Kyuwang Kim
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.32 no.2
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    • pp.29-36
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    • 2024
  • Pilots are indispensable and central to the aviation industry, with the relevance of their psychological stress and resultant human errors increasingly recognized as critical. This study aims to meticulously explore the interrelations between psychological stressors and associated factors among helicopter pilots, assessing the consequent effects on potential accidents and incidents. The study comprised active pilots from domestic helicopter airlines, with data collated through both focus group interviews (FGI) and comprehensive surveys. These data were subsequently analyzed using SPSS and AMOS for structural equation modeling. The results reveal that heightened psychological stress in helicopter pilots correlates with an increased incidence of human errors, which in turn, elevates the likelihood of potential safety incidents. Based on these findings, it is proposed that interventions designed to mitigate psychological stress among pilots could significantly reduce human errors and enhance overall aviation safety. This research provides crucial insights into specific ways to improve the operational conditions for helicopter pilots and strengthen the safety protocols within the aviation industry.

Flow-induced vibrations of dual-cylinders in axial flow via LES simulations

  • Kangfei Shi;Yu Cao;Zhanying Zheng;Shun Lu;Menglong Liu
    • Nuclear Engineering and Technology
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    • v.56 no.9
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    • pp.3812-3825
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    • 2024
  • The axial-flow-induced vibration of fuel rods in the nuclear power plant is closely related to nuclear safety. In this article, a numerical study is performed on vibration of two elastic cylinders arranged side-by-side in axial flow. Large eddy simulation is employed to predict the turbulent flow. The numerical method has been verified using the experimental root-mean-square vibration amplitude of a single cylinder. A wide range of inflow velocities u*, incident turbulence intensity Tu and space ratio P/D have been examined, where D and P are the diameter and centre-to-centre distance of the cylinders, respectively. The results show that the vibration amplitudes increase with an increasing u*, comparable to the case of a single cylinder in axial flow. However, the two cylinders could bend outwards during a relatively high u* and low Tu. Although Tu significantly affects the amplitudes of the cylinders, it does not change the vibration frequency and the critical velocity at which buckling instability occurs. As the gap between the two cylinders is sufficiently small, the vibration amplitude enhances significantly due to the pronounced hydrodynamic interaction between the two elastic cylinders and surrounding fluid. The direction of buckling is no longer random but fixed.

Epic Theatre Reexamined from the Viewpoint of Cognitive Science (인지과학의 관점에서 본 서사극 이론)

  • Kim, Yongsoo
    • Journal of Korean Theatre Studies Association
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    • no.49
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    • pp.133-169
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    • 2013
  • Reexamining Brecht's theoretical hypotheses in terms of cognitive science, this essay arrived at several temporary interpretations. Cognitive science implies that empathy can precede the rational understanding in Verfremdungseffekt. The spectator tends to simulate the unfamiliar incident and character and feels the consequential embodied emotion that leads to the cognitive understanding. The similar situation can be found in social gestus. According to cognitive science, gesture(social gestus) is simulated in the mirror-neuron of spectator, arousing consequently the embodied emotion that triggers the succeeding understanding. The spectator apts to experience and feel physically the moving gesture before decoding it as a social signification. Brecht's intention that attempts to reveal the duality of actor and character by eliminating the fourth wall is negated by cognitive science. According to the theory of conceptual blending, the spectator under the eliminated fourth wall mixes actor and character, and simulates this blending image so that he experiences it imaginatively. As such, another kind of illusion can be formed when a fourth wall is collapsed. Meanwhile, the critical thinking of spectator Brecht wanted can be hard to occur during the performance. It is necessary for the spectator to recollect the bygone dialogue and action in terms of social context as if he presses the pause, stopping the playback while watching a play in video. In this respect the social meaning Brecht intended can be achieved more effectively by the stop motion like tableau. It would not only give the time for the spectator to consider the implied social signification, but also make him possible to decode a semiotic meaning as if interpreting a still picture. Or it can be delivered by the dialogue that expresses the playwright's critical judgement. In this case, the subject of critical thinking is not the spectator but the author. The alternative explanation that the cognitive science suggests illuminates theoretically the reasons why Brecht's theory fails to be realized in practice. In a sense, Brecht's theory is nothing but a theoretical hypothesis. It takes the premise that the emotion hinders the rational thinking, understanding emotion and reason oppositively like Plato. This assumption is negated easily by the recent cognitive science that sees the reason as a by-product of physical experience including emotion. The rational understanding, in this sense, begins from the embodied emotion. As such the cognitive science denies the dichotomy of emotion and reason that Brecht adopted. The theoretical hypothesis of cognitive science makes us recognize again the importance of bodily experience in theatre. In theatre the spectator tends to experience physically before decoding the intellectual meaning. The spectator Brecht wanted, therefore, is far from the reality. The spectator usually experiences and reacts physically before decoding the meaning critically. Thus Brecht's intention can be realized by the embodied emotion resulted from simulation. This tentative interpretation suggests that we need to pay more attention to the empirical study of spectatorship, not remaining in a speculative study.

Finite Element Simulation of Elastic Waves for Detecting Defects and Deteriorations in Underwater Steel Plates (수중강판의 결함 및 열화 검출을 위한 탄성파 유한요소 시뮬레이션)

  • Woo, Jinho;Na, Won-Bae
    • Journal of Ocean Engineering and Technology
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    • v.27 no.3
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    • pp.61-66
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    • 2013
  • This paper presents the results of finite element simulations of elastic wave propagation in an underwater steel plate and the verification of a proposed method utilizing elastic wave-based damage detection. For the simulation and verification, we carried out the following procedures. First, three-dimensional finite element models were constructed using a general purpose finite element program. Second, two types of damages (mechanical defects and deteriorations) were applied to the underwater steel plate and three parameters (defect location, defect width, and depth) were considered to adjust the severity of the applied damages. Third, elastic waves were generated using the oblique incident method with a Gaussian tone burst, and the response signals were obtained at the receiving point for each defect or deterioration case. In addition, the received time domain signals were analyzed, particularly by measuring the magnitudes of the maximum amplitudes. Finally, the presence and severity of each type of damage were identified by the decreasing ratios of the maximum amplitudes. The results showed that the received signals for the models had the same global pattern with minor changes in the amplitudes and phases, and the decreasing ratio generally increased as the damage area increased. In addition, we found that the defect depth was more critical than the width in the decrease of the amplitude. This mainly occurred because the layout of the depth interfered with the elastic wave propagation in a more severe manner than the layout of the width. An inverse analysis showed that the proposed method is applicable for detecting mechanical defects and quantifying their severity.

A Study on a Crack Evaluation Technique for Turbine Blade Root Using Phased Array Ultrasonics (위상배열 초음파를 이용한 터빈 블레이드 루트부내 결함평가 기법 연구)

  • Cho, Yong-Sang;Jung, Gye-Jo;Park, Sang-Ki;Kim, Jae-Hoon
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.2
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    • pp.151-157
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    • 2004
  • Ultrasonic testing is a kind of nondestructive test to detect a crack or discontinuity in materials or on material surfaces by sending ultrasound to it. This conventional ultrasonic technique has some limitations in reliably detecting crack or accurately assessing materials in the case of complex-shaped power plant components such as a turbine blade root. An alternative method for such a difficult inspection is highly needed. In this study, application of a phased array ultrasonic testing (UT) system to a turbine blade, one of the critical power plant components, has been considered, and the particular incident angle has been determined so that the greatest track detectability and the most accurate crack length evaluation nay be achieved. The response of ultrasonic phased array was also analyzed to establish a special method to determine the track )ength without moving the transducer. The result showed that the developed method for crack length assessment is a more accurate and effective method, compared with the conventional method.

Morale enhancing determination model of information security (정보보호 사기진작 결정모델 연구)

  • Kim, Kyongwon;Lim, Jong In;Lee, Kyung-Ho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.25 no.4
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    • pp.889-903
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    • 2015
  • As the number of recent information security incident occurrence increases, more and more workload and liability pressure are given to info-security professionals, which results in decrease of morale level of working groups in the field. In order to solve this problem, Korean government is providing various action plans to improve the morale level of info-security professionals, and also requiring financial companies to submit its own action plan of increasing morale of info-security professionals to Financial Service Agency. For this study, based on the previous studies and relevant professionals' interviews, we selected 16 critical morale increase variables, and performed survey for empirical analysis. As a result, 3 features; role, system, and relationship were presented as the main factor of morale increasement of info-security professionals. This study also suggests a decision making method of utilizing the developed morale measurement model for individual organizations.

Levels and Countermeasures of PTSD among Police Officers (경찰관의 PTSD 수준 및 대처방안)

  • Sin, Seong-Won
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.266-272
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    • 2011
  • According to many studies, a large number of police officers who had recently been exposed to an emergency situation has serious psychological stress and Post Traumatic Stress Disorder(PTSD) symptoms impact on morale, absenteeism, occupational health, early retirement, family relationships. However, in Korea as it looked during the empirical study of police officers with PTSD had a few. In this study, levels of PTSD among police officers to identify and respond accordingly was to seek ways. The officer's PTSD levels vary according to the study is the relatively high level, when compared to firefighters is a relatively high level. So, I suggested some countermeasures. I presented discovery and management of high risk police officers, distribution of critical incident stress management, introduction of employee assistance programs, active intervention of colleagues and family members, training of stress management techniques.

Gamma-ray Dose Measurements in a Human Phantom Using Thermoluminescent Dosimeter

  • Yoo, Young-Soo;Lee, Hyun-Duk
    • Nuclear Engineering and Technology
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    • v.6 no.4
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    • pp.239-247
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    • 1974
  • A human phantom of polyethylene has been designed and sculptured for studying the effective radiation safety control. The phantom has the approximate size of the Korean adult and was sliced into thirty-five transverse slabs, 2.5 cm thick, The relative dose at the specified position was determined from the exposure that a TLD badge worn on the surface of the phantom body received from external ${\gamma}$-ray. The variation of the exposure as a function of depth in the phantom was measured for uncollimated ${\gamma}$-ray using TLD rods, and also isodose curves were obtained for the anatomical cross-section of the critical organs of the body. To simulate radiation exposure condition in the nuclear facility, measurements were made for given angles of incident ${\gamma}$-ray. The front to back attenuation factor for human phantom of thickness 20 cm was 0.439 for Cs$^{137}$ ${\gamma}$-ray which is in reasonable agreement with the published data.

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Measuring (and Increasing) the Value of Academic Libraries

  • Tenopir, Carol;King, Donald W.
    • Journal of the Korean Society for Library and Information Science
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    • v.44 no.4
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    • pp.19-31
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    • 2010
  • The value of the university library to faculty, students, and administrators has long been assumed. In an era of decreasing resources and increasing choices, academic librarians must now find the best ways to measure and demonstrate the value of the library to all of their stakeholders, including faculty members, graduate students, undergraduate students, administrators, and funders. Techniques to assess and measure value can also help library decision makers select the products and services that provide the highest return on investment (ROI) to the university community. It is important to measure and convey the value of the academic library; it is also possible to increase the value of the library to the university by carefully refocusing the academic library's products and services. In this presentation I will discuss methods and results from a recently completed study in eight countries that measured the value and ROI of e-journals to the grants process. The Return on Investment (ROI) of the e-journals collection to grant funding ranged from over 15:1 to just under 1:1 in 9 institutions. In addition, many other qualitative and quantitative measures of value are as important as derived measures like ROI. Building on that research study, I am now leading a team that includes the Association of Research Libraries (ARL) and several university libraries in a project funded by the U.S. Institute of Museum and Library Services. We are collecting data using on the value of a wide range of library services using several methods for measuring the value of what the university library contributes to the institution and its stakeholders.