• Title/Summary/Keyword: cause analysis

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A Study of Methodology to Examine Organizational Root Causes through the Retrospect Error Analysis of Railroad Accident Cases

  • Ra, Doo Wan;Cha, Woo Chang
    • Journal of the Ergonomics Society of Korea
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    • v.34 no.2
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    • pp.103-113
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    • 2015
  • Objective: This study proposes a systematic process to present the analysis methods and solutions of organizational root causes to human errors on the railroad. Background: In fact, organizational root cause such as organizational culture is an important factor in the safety concerns on human errors in the nuclear power plant, railroad and aircraft. Method: The proposed process is as follows: 1) define analysis boundary 2) select human error taxonomy 3) perform accident analysis 4) draw root causes with FGI 5) review root causes analysis with survey 6) chart analysis of root causes, and 7) propose alternatives and solutions. Results: As a result, root causes of the organizations like railroad and nuclear power plant came from the educational problems, violations, payoff system, safety culture and so forth. Conclusion: The proposed process does predict potential railroad accident through retrospect error analysis by building new human error taxonomies and problem solution. Application: This study would contribute to examination of the relationship between human error-based accidents and organizational root causes.

Structural behavior of cable-stayed bridges after cable failure

  • Kim, Seungjun;Kang, Young Jong
    • Structural Engineering and Mechanics
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    • v.59 no.6
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    • pp.1095-1120
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    • 2016
  • This paper investigates the change of structural characteristics of steel cable-stayed bridges after cable failure. Cables, considered as the intermediate supports of cable-stayed bridges, can break or fail for several reasons, such as fire, direct vehicle clash accident, extreme weather conditions, and fatigue of cable or anchorage. Also, the replacement of cables can cause temporary disconnection. Because of the structural characteristics with various geometric nonlinearities of cable-stayed bridges, cable failure may cause significant change to the structural state and ultimate behavior. Until now, the characteristics of structural behavior after cable failure have rarely been studied. In this study, rational cable failure analysis is suggested to trace the new equilibrium with structural configuration after the cable failure. Also, the sequence of ultimate analysis for the structure that suffers cable failure is suggested, to study the change of ultimate behavior and load carrying capacity under specific live load conditions. Using these analysis methods, the statical behavior after individual cable failure is studied based on the change of structural configuration, and distribution of internal forces. Also, the change of the ultimate behavior and load carrying capacity under specific live load conditions is investigated, using the proposed analysis method. According to the study, significant change of the statical behavior and ultimate capacity occurs although just one cable fails.

Cause of Fuel Leakage from the Inner Piston Packing of Afterburner Fuel Pump in an Aircraft J85-GE-21 Turbojet Engine (전투기 J85-GE-21 터보제트 엔진 후기 연소기 연료펌프의 내부 피스톤 패킹 연료 누출 원인)

  • Kim, Ik-Sik;Hwang, Young-Ha;Sohn, Kyung-Suk;Lee, Jung-Hun;Kim, Sung-Uk
    • Elastomers and Composites
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    • v.49 no.4
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    • pp.305-312
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    • 2014
  • Most of military supersonic aircraft use an afterburner. It plays an important role in performing unusual duties for supersonic flight, takeoff, and combat situations. Recently, repetitive fuel leakage from the inner piston packing rubber of afterburner fuel pump in an aircraft J85-GE-21 turbojet engine has happened. These failures have only happened in one manufacturer's parts of two manufacturers. Thus, the cause of these failures was investigated through the comparative analysis for both the failed and the unfailed with two different manufacturers using various analysis methods. The failure analysis was performed using analysis methods such as swelling or swelling ratio, total sulfur content, polymer identification, loading and surface area of carbon black, and hardness. Consequently, the main cause of this failure was identified to be insufficient loading of carbon black as a reinforcing agent, together with small surface area of carbon black and somewhat low sulfur content.

Analysis of Performance Influencing Factor in Chemical Process Industry : A Practical Application (석유화학 산업에서의 수행영향인자 및 근본원인 분석 결과)

  • Yu, Kwang-Soo;Kim, Eun-Jung;Kim, Yong-Soo
    • Journal of the Korean Institute of Gas
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    • v.11 no.2 s.35
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    • pp.60-64
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    • 2007
  • Chemical Process industry in Korea has over 30 year's of history and is likely to face potential incidents. The traditional risk analysis and control system in Chemical Process industry focuses on mechanical defects, overlooking the human performance control. Although development of automation technology and controlling technology was necessary, human decision factor is essential to preventing accidents in the Chemical Process. Almost all serious accidents take place when inappropriate humanperformance and mechanical defects of safety equipments simultaneously occurs. The AHRA(Advanced Human Reliability Analyzer) software has been developed to collect failure data and analyze human error probability (Reliability) in Chemical Process Industry in Korea. This paper describes the HRA analysis result of PIF(Performance Influencing Factor) evaluation, HEP(Human Error Probability) and root cause of accidents by applying a Chemical Process Industry related accident data. This analysis result should present a scheme that, by controlling human error factor other than putting safety management funds into the machinery in plants, can reduce cost and maximize the safety in Chemical Process Industry.

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The Role of the ICAO in Implementing the FANS and its Applications in Air and space Law (바르샤바협약상(協約上) Wilful Misconduct의 개념(槪念))

  • Choi, June-Sun
    • The Korean Journal of Air & Space Law and Policy
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    • v.6
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    • pp.191-215
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    • 1994
  • The concept of 'wilful misconduct" was initally used in article 25 of the Warsaw Convention of 1929. The concept was defined in the Hague Protocol, 1955, as having the following two differing concepts: i) "with the intent to cause damage" and ii) "recklessly and with the knowledge that damage would probably result." The concepts contained in the Hague Protocol were used in various international Conventions on carriage by sea, such as Article 2(e) and Article 3(4) of the Protocol adopted at Brussels on Feb. 23, 1968 to amend the International Convention for the Unification of Certain Rules of Law relating to Bills of Lading, signed at Brussels, Aug. 25, 1929(Hague-Visby Rules), Article 13 of the Athens Convention relating to the Carriage of Passengers and their Luggage by Sea, Dec. 13. 1974, Article 4 of the Convention on Limitation of Liability for Maritime Claims, 1976, Article 8(1) of the U.N. Convention on the Carriage of Goods by Sea, 1978(Hamburg Rules) and Article 21 (1) of the U.N. Convention on International Multimodal Transport of Goods, Geneva, 1980. The same concepts were also adopted in Article 746, 789-2(1), 789-3(2) of the Korean Maritime Commercial Law, revised in 1991. As of yet, the legal system of Korean Private Law recognizes only the concepts of "Vorsatz" and "grobe Nachlassigkeit", as is the case with German Private Law. The problem is that the concepts in the Convention do not coincide precisely with the concepts of "Vorsatz" and "grobe Nachlassigkeit". The author has conducted a comparative analysis of the treatment of the concepts of wilful misconduct and its varied interpretations, that is, "with the intent to cause damage" and "recklessly and with the knowledge that damage would probably result" in the Anglo-American law and in the continental European law in the following manner: 1. Background in which the concept of wilful misconduct was introduced in the Warsaw Convention. 2. The concept of "dol" in French private law. 3. The concepts of "Vorsatz" and "grobe Nachlassigkeit" in Korean private law. 4. Analysis of the concept of wilful misconduct in Anglo-American case law. 5. Analysis of the cases interpreting the concepts of "with intent to cause damage" and "recklessly and with knowledge that damage would probably result" in various jurisdictions. 6. The need to incorporate the concepts of "with the intent to cause damage" and "recklessly and with the knowledge that damage would probably result." 7. Faute inexcusable in French private law. Based upon the comparative analysis, the author points out the difference between the concepts of "wilful misconduct" or "with the intent to cause damage" and "Vorsatz", and between the concepts of "recklessly and with the knowledge that damage would probably result" and "grobe Nachlassigkeit" in the Convention and that of the Korean Private Law system. Additionally, the author emphasizes the importance of the unification in the interpretation of the provisions of the Conventions world wide.

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Characteristic Analysis of Chattering in Finishing Mill (열연 사상압연기 채터링 특성 분석에 관한 연구)

  • Shin, N.H.;Lim, E.S.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1854-1858
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    • 2000
  • Chattering phenomenon is an abrupt relative vibration between the strip and rolls of rolling machine in working. It inevitably results from the progress of the degeneration in the mill facilities. This research was carried out in order to analyze the characteristic and find the cause of chatter mark in finishing mill and it was founded that one of major cause is appearance of dead zone at pinion stand in case of excessive roll force.

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Research on characteristic analysis and reliability improvement of check valve for turbo compressor (터보 압축기용 체크 밸브의 특성 분석과 신뢰성 개선)

  • Kim, Kyung-Soo;Kang, Bo-Sik;Lee, Seung-Hun
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1381-1386
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    • 2008
  • In this study, we studied failure cause of check valve through analysing characteristic of it used in turbo compressor. We researched how to improve to reduce chaterring occurrence which is cause of main failure mode and suggested how to improve reliability of check valve through it.

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