• Title/Summary/Keyword: Systematic Failure

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On the Reduction of Systematic Failure by Realizing a Method for Functional Safety (기능안전의 구현을 통한 Systematic Failure의 감축에 관한 연구)

  • Jung, Ho Jeon;Park, Chan Woo;Lee, Jae-Chon
    • Journal of the Korea Safety Management & Science
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    • v.15 no.4
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    • pp.161-169
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    • 2013
  • Due to the recent advances in technology, the systems are becoming more demanding in terms of functionality and implementation complexity. Therefore, when system failures are involved in such complex systems, the effects of the related safety issues can also be more serious, thereby causing in the worst case irrecoverable hazards on both human being and properties. This fact can be witnessed in the recent rail systems accidents. In general, the accidents can be attributed to the systematic failure or the random failure. The latter is due to the aging or unsatisfied quality of the parts used in implementation or some unexpected external cause that would otherwise result in accidents whereas the former is usually related to incomplete systems design. As the systems are becoming more complex, so are the systematic failures. The objective of the paper is to study an approach to solving the systematic failure. To do so, at first the system design process is augmented by the functional safety activities that are suggested in the standard IEC 61508. Analyzing the artifacts of the integrated process yields the traceability, which satisfies the requirements for reduction of systematic failure as provided in ISO 26262. In order to reduce systematic failure, the results are utilized in the conceptual design stage of systems development in which systems requirements are generated and functional architecture is developed.

Dyadic Interventions for Heart Failure Patients and Their Family Caregivers: A Systematic Review (심부전 환자와 가족 돌봄제공자를 위한 다이애딕 중재에 관한 체계적 고찰)

  • Kim, Da-Young;Kim, Sun-Hee;Park, Eun Ju;Son, Youn-Jung
    • Journal of Korean Critical Care Nursing
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    • v.14 no.3
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    • pp.113-127
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    • 2021
  • Purpose : This systematic review was conducted to identify which dyadic intervention could be implemented for heart failure patient-family caregiver dyads to improve patient and/or their family caregivers outcomes. Method : Eleven databases were searched from their inception to July, 2021. This review considered any randomized controlled trials that evaluated the effectiveness of intervention including heart failure patient-family caregiver dyads. Two reviewers independently evaluated the methodological quality using the Cochrane Collaboration's tool for assessing risk of bias and extracted details of the included studies. The studies included in this review were not suitable for meta-analysis and therefore the results were presented as a narrative summary. Results : Six studies including 900 dyads were included and mainly primary family caregiver of patients was spouse. Majority of dyadic intervention were focused on psychoeducational intervention excepting one study on mobile health intervention. All studies included in this review focused on patients' outcomes compared to family caregivers' outcomes and dyadic outcomes. Individual interventions improved quality of life among heart failure patients and their family caregivers in two articles. The overall quality of selected articles was low. Conclusions : This study provides moderate support for the use of a dyadic intervention to improve quality of life among heart failure patients and their family caregivers. More rigorous high-quality studies investigating interventions to meet the needs of patient and family caregivers in heart failure care are needed.

Reliability Analysis of Multiple Failure Modes of Rubble-Mound Breakwaters (경사제의 다중 파괴모드에 대한 신뢰성 해석)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.137-147
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    • 2008
  • A reliability analysis has been performed to investigate the systematic stability of multi-failure modes of rubble-mound breakwaters. The reliability functions of four different failure modes are established straightforwardly. AFDA(Approximate Full Distribution Approcah) reliability models for each failure modes are directly developed and satisfactorily calibrated through the comparison with CIAD's results. In the reliability analysis of single failure mode, the probabilities of failure are calculated and the influence coefficients of random variables in the failure modes are properly evaluated. Meanwhile, three different models such as uni-modal bounds, bimodal bounds, and PNET are applied to evaluate the probabilities of failure of multi-failure modes for rubble-mound breakwaters. It may be found that uni-modal bounds tend to overestimate the probability of failure of multi-failure modes. Therefore, for the systematic reliability analysis of multi-failure modes, it is recommended to use bi-modal bounds or PNET which consider the correlation between the failure modes for rubble-mound breakwaters. By introducing the reliability analysis of multi-failure modes, it could be possible to find out the additional probabilities of failure occurred by the multi-failure modes of a multi-component system such as rubble-mound breakwaters.

A Systematic Literature Review Towards Service Oriented Architecture Adoption from 2009 to 2015

  • Niknejad, Naghmeh;Ghani, Imran;Hussin, Ab Razak Che;Jeong, Seung Ryul
    • International journal of advanced smart convergence
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    • v.7 no.3
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    • pp.79-91
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    • 2018
  • Service Oriented Architecture (SOA) has appeared as an absorbing architectural approach that empowers the available systems to reveal their performance in the act of services, without creating important changes to the systems. This approach, due to its flexibility of adoption, has been widely recognized as an appropriate approach for implementing in organizations by many scholars and practitioners. Though, there are many studies that depict success factors of SOA; at the same time a few minor cases of failure has also been reported in the literature. In spite of the availability of rich material on SOA (in general), there is no systematic literature review on the potential aspect of SOA adoption factors. Hence, this article presents a systematic review of existing studies related to the SOA adoption and its success and failure factors from 2009 to 2015. The principle purpose of the study is to bring forward the existing issues and share our findings with researchers. Moreover, the findings of this paper would help IT experts in organizations to concentrate on the key factors highlighted in this study, so that they could decide whether it is advisable to adopt SOA or not in their context.

Factors Associated With Failure of Health System Reform: A Systematic Review and Meta-synthesis

  • Mahboubeh Bayat;Tahereh Kashkalani;Mahmoud Khodadost;Azad Shokri;Hamed Fattahi;Faeze Ghasemi Seproo;Fatemeh Younesi;Roghayeh Khalilnezhad
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.2
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    • pp.128-144
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    • 2023
  • Objectives: The health system reform process is highly political and controversial, and in most cases, it fails to realize its intended goals. This study was conducted to synthesize factors underlying the failure of health system reforms. Methods: In this systematic review and meta-synthesis, we searched 9 international and regional databases to identify qualitative and mixed-methods studies published up to December 2019. Using thematic synthesis, we analyzed the data. We utilized the Standards for Reporting Qualitative Research checklist for quality assessment. Results: After application of the inclusion and exclusion criteria, 40 of 1837 articles were included in the content analysis. The identified factors were organized into 7 main themes and 32 sub-themes. The main themes included: (1) reforms initiators' attitudes and knowledge; (2) weakness of political support; (3) lack of interest group support; (4) insufficient comprehensiveness of the reform; (5) problems related to the implementation of the reform; (6) harmful consequences of reform implementation; and (7) the political, economic, cultural, and social conditions of the society in which the reform takes place. Conclusions: Health system reform is a deep and extensive process, and shortcomings and weaknesses in each step have overcome health reform attempts in many countries. Awareness of these failure factors and appropriate responses to these issues can help policymakers properly plan and implement future reform programs and achieve the ultimate goals of reform: to improve the quantity and quality of health services and the health of society.

A Numerical Ductile Failure Simulation Technique Based on Phenomenological Damage Concept (수치해석을 이용한 현상학적 연성파괴 모사 기법)

  • Kim, Nak-Kyun;Oh, Chang-sik;Min, Sung-hwan;Kim, Yun-Jae
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.5 no.2
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    • pp.27-34
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    • 2009
  • This paper proposes a simple numerical method to simulate ductile failure behaviors. The method is based on finite element analysis with a simple damage theory. To validate the proposed method, simulated results are compared with experimental data. Despite its simplicity, the proposed method well predicts experimental results systematic analyses are also performed to investigate the effect of the element size.

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Tool life in Metal Forming Processes (소성가공에 있어서의 금형수명)

  • 최재찬;김병민
    • Transactions of Materials Processing
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    • v.3 no.2
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    • pp.147-155
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    • 1994
  • The service life of tools in metal forming technology is to a large extent limited by wear and fatigue fracture of the active elements. This presents a basic request for tool cost minimization and reduction of extensive machine down time, caused by premature tool failure. Currents developments are dominated by steps to reduce the causes of tool failure. A main problem of forming technology remains the insufficient reliability of tools due to a large and incalculable life time fluctuation. Only a systematic investigation of the failure mechanisms and operational loading of tools can lead to future improvements in tool layout, that is optimization of tool usage.

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A Study for FMEA and Optimization of Failure Diagnosis Sequence Using Probability of Failure Cause (고장원인 확률을 이용한 FMEA와 고장진단 순서의 최적화)

  • Song, Kee-Tae;Kim, Min-Ho;Baek, Young-Gu;Lee, Key-Seo;Kim, Soo-Myong
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.749-757
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    • 2007
  • Recently, with increasing interested in improvement of operational reliability and the systematic maintenance activities, the RCM analysis has been applied and tried to lots of applicable industries. This study covers applying the probability of failure cause to FMEA, and proposes an analytical method for this. Also, the measures of quantitative classification for the result of failure cause probability are addressed. Based on the field data, this thesis presents an identification for causes and characteristics of failure, and reviews them periodically from the above methodologies. As using FMEA applied the probability of failure cause, we in the future can look forward to improvement of efficiency for failure diagnosis & inspection, and reliability.

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User Experience Validation Using the Honeycomb Model in the Requirements Development Stage

  • Kim, Neung-Hoe
    • International journal of advanced smart convergence
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    • v.9 no.3
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    • pp.227-231
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    • 2020
  • Recently, the importance of user experience (UX) has been rapidly increasing. Its utilization is emphasized for development of systems, products, and services. User experience is widely used across industries including services, products, processes, society, and culture. Therefore, if it is unsatisfactory, it is likely to have a direct negative impact on the corresponding system, product, or service. The failure to analyze user experience causes significant damage to the project, which may lead to its failure or redevelopment; it is hence necessary to prioritize the verification of UX in the earliest stages of development. The requirements development stage, which is a preceding stage, is an appropriate stage for the verification of user experience because the identification of user needs is completed and prototypes can be implemented. In this paper, we proposed a systematic requirements development stage; it adds user experience verification activities to the requirements development stage, using the Honeycomb model, which is a widely used tool for verifying the overall UX. User experience verification was added to the existing requirements development activities, which consisted of three steps: model definition and requirements placement, discussions between external and internal stakeholders, and review by internal stakeholders. By easily validating the user experience through this systematic requirements development stage, we expect to minimize the damage to the project due to the failure of the user experience analysis and increase the possibility of success.

Reliability Management of Mechanical Ventilator in Intensive Care Unit Using FMEA Based on ISO14971 (ISO14971 기반 FMEA를 이용한 중환자실내 인공호흡기 신뢰성 관리)

  • Hyun Joon, Kim;Won Kyu, Kim;Tae Jong, Kim;Gee Young, Suh
    • Journal of Biomedical Engineering Research
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    • v.44 no.1
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    • pp.19-24
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    • 2023
  • Due to the spread of COVID-19, many patients with severe respiratory diseases have occurred worldwide, and accordingly, the use of mechanical ventilators has exploded. However, hospitals do not have systematic risk management, and the Medical Device Regulation also provides medical device risk management standards for manufacturers, but does not apply to devices in use. In this paper, we applied the Failure Mode Effects Analysis (FMEA) risk analysis technique based on the International Standard ISO 14971 (Medical Devices-Application of risk management to medical devices) for 85 mechanical ventilators of a specific model in use in hospitals. Failure modes and effects of each parts were investigated, and risk priority was derived through multiplication of each score by preparing criteria for severity, occurrence, and detection for each failure mode. As a result, it was confirmed that the microprocessor-based Patient Unit/Monitoring board in charge of monitoring scored the highest score with 36 points, and that reliability management is possible through systematic risk management according to priority.