• Title/Summary/Keyword: reliability review

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Reliability Prediction & Design Review for Core Units of Machine Tools (공작기계 핵심 Units의 신뢰성 예측 및 Design Review)

  • 이승우;송준엽;이현용;박화영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.133-136
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    • 2003
  • In these days, the reliability analysis and prediction are applied for many industrial products and many products require guaranteeing the quality and efficiency of their products. In this study reliability prediction for core units of machine tools has been performed in order to improve and analyze its reliability. ATC(Automatic Tool Changer) and interface Card of PC-NC that are core component of the machine tools were chosen as the target of the reliability prediction. A reliability analysis tool was used to obtain the reliability data(failure rate database) for reliability prediction. It is expected that the results of reliability prediction be applied to improve and evaluate its reliability. Failure rate, MTBF (Mean Time Between Failure) and reliability for core units of machine tools were evaluated and analyzed in this study.

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Assessing Reliability of Medical Record Reviews for the Detection of Hospital Adverse Events

  • Ock, Minsu;Lee, Sang-il;Jo, Min-Woo;Lee, Jin Yong;Kim, Seon-Ha
    • Journal of Preventive Medicine and Public Health
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    • v.48 no.5
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    • pp.239-248
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    • 2015
  • Objectives: The purpose of this study was to assess the inter-rater reliability and intra-rater reliability of medical record review for the detection of hospital adverse events. Methods: We conducted two stages retrospective medical records review of a random sample of 96 patients from one acute-care general hospital. The first stage was an explicit patient record review by two nurses to detect the presence of 41 screening criteria (SC). The second stage was an implicit structured review by two physicians to identify the occurrence of adverse events from the positive cases on the SC. The inter-rater reliability of two nurses and that of two physicians were assessed. The intra-rater reliability was also evaluated by using test-retest method at approximately two weeks later. Results: In 84.2% of the patient medical records, the nurses agreed as to the necessity for the second stage review (kappa, 0.68; 95% confidence interval [CI], 0.54 to 0.83). In 93.0% of the patient medical records screened by nurses, the physicians agreed about the absence or presence of adverse events (kappa, 0.71; 95% CI, 0.44 to 0.97). When assessing intra-rater reliability, the kappa indices of two nurses were 0.54 (95% CI, 0.31 to 0.77) and 0.67 (95% CI, 0.47 to 0.87), whereas those of two physicians were 0.87 (95% CI, 0.62 to 1.00) and 0.37 (95% CI, -0.16 to 0.89). Conclusions: In this study, the medical record review for detecting adverse events showed intermediate to good level of inter-rater and intra-rater reliability. Well organized training program for reviewers and clearly defining SC are required to get more reliable results in the hospital adverse event study.

Literature Review on the Reliability in KSQM for 50 Years (품질경영학회 50주년 특별호: 신뢰성 분야 연구 리뷰)

  • Sung, Si-Il;Kim, Yong Soo;Mun, Byeong Min;Bae, Suk Joo
    • Journal of Korean Society for Quality Management
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    • v.44 no.1
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    • pp.29-42
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    • 2016
  • Purpose: This paper reviews the papers on reliability issues which are published in the Journal of the Korean Society for Quality Management (KSQM) since 1965. The literature review is purposed to survey a variety of reliability issues for several categories Methods: We divide all of reliability issues into 9 categories: acceleration test, reliability estimation, system reliability, software reliability, reliability data collection and analysis method, lifetime distribution, maintenance and warranty strategy, reliability applications, and reliability applications to military area Results: Dividing all of papers on reliability published in KSQM for 50 years into 9 categories, we provide a chronological roadmap for individual categories, and summarize the contents and contributions of surveyed papers Conclusion: The review paper is expected to provide future direction to improve reliaiblity theories and applications in manufacturing and service industries

A Systematic Review on Trunk Impairment Scale for Stroke Patients

  • Lee, Min Joo;Lee, Seul;Park, Dae-Sung
    • Physical Therapy Rehabilitation Science
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    • v.10 no.3
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    • pp.379-386
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    • 2021
  • Objective: The purpose of this study was to systematically review the trunk impairment scale that are used to assess the trunk control of stroke patients. Design: A systematic review Methods: Stroke subjects were categorized as acute, subacute, chronic. In this systematic review, the studies published between 2000 and 2020 were selected. A literature search using the keywords 'QUADAS', 'stroke', 'trunk impairment scale'. Data sources included RISS, GOOGLE Scholar and DBpia. We assessed the quality of assessment tools using Quality Assessment of Diagnostic Accuracy Studies tool. Results: We reviewed 18 studies. 7 of the 18 studies reported reliability results, 10 reported validity results. The QUADAS tool quality evaluation of 17 literatures extracted except for one randomized control test among 18 literatures showed a range of 3 to 13 points. 5 of the 18 studies are presented with the Cronbach alpha coefficient indicating reliability using internal consistency, all of which are more than 0.8. All studies that presented test-retest reliability, intra-rater reliability, and inter-rater reliability showed high agreement with an intra-class correlation coefficient of 0.75 or more. Conclusions: A systematic review of the study of the application of the trunk impairment scale for stroke patients will help provide criteria for future studies and application of the trunk impairment scale in clinical practice.

Design Review and Common-Cause Failure Modeling of mechanical Parts (기계류품 DR 및 공통원인고장 모델링)

  • 하영주;송준엽;이후상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.324-327
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    • 2001
  • This paper shows an example of the Design Review and Common-Cause Failure (CCF) Modeling of mechanical Parts. Reliability should be continuously monitored during the entire period of design. Design Review is the procedure to improve the reliability for the product. We proposed the reliability assessment and design review method. CCF Model is the general dependent model considering the failure mode effects several component simultaneously. This study considers the computation of the network with dependent components. It is important that CCF model is applied for mechanical pars.

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Development of Energy-FMEA for Energy Review of ISO 50001 Energy Management System

  • Song, Kyung-Il;Jang, Joong-Soon
    • Journal of Applied Reliability
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    • v.14 no.2
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    • pp.137-146
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    • 2014
  • This paper is to develop Energy-FMEA for Energy Review of ISO 50001 Energy Management System. Energy Review is the core requirement of ISO 50001. This study develop Energy-FMEA and suggest Energy Review Inventory and Assessment Criteria for performing Energy-FMEA. Also, it shows case study to verify whether to proper.

A Review of a System for Improving the Reliability of Domestic Measurement Results regarding the Work Environment (국내 작업환경 측정결과 신뢰성 향상을 위한 제도 고찰)

  • Kim, Ki-Youn;Kang, Taesun;Lee, Seung Gil;Park, Hae Dong;Jeong, Jee Yeon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.27 no.2
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    • pp.87-96
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    • 2017
  • Objectives: Improvement of the reliability of work environment measurement results is one of the principal subjects to be resolved in the field of industrial hygiene. Thus, this study was conducted in order to review domestic programs for enhancing the reliability of work environment measurement results and propose a more efficient management plan for workplace monitoring. Materials and Methods: The current domestic programs reviewed in this study are the quality control system and evaluation system for industrial hygiene laboratories, the reliability system accompanied by KOSHA (the Korea Occupational Safety and Health Agency), the system of permissible exposure limits and observed inspection system for permissible exposure limits. Their contents and data were analyzed by reviewing articles, reports, and guidelines related to reliability improvement for work environment measurement results. Results: As a result of the literature review, all the domestic programs investigated in this study had both merits and demerits in terms of considering the reliability of work environment measurement results. In particular, the fact that preliminary notification is provided to the head of a workplace before implementation would be an obstacle for elevating the reliability of work environment measurement results. Conclusions: Based on the review results obtained from this study, it is proposed that on-site measurement without preliminary notification should be considered for a more efficient inspection system that would enhance the reliability of workplace monitoring.

Development of Web-based Design Review System for Reliability and Safety Knowledge Management

  • Otsuka, Yuichi;Yukawa, Takashi;Mutoh, Yoshiharu
    • International Journal of Safety
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    • v.9 no.2
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    • pp.22-28
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    • 2010
  • This paper describes a web-based design review system as a knowledge management system relating reliability and safety system design. Since people's consciousness for safety and security become sensitive and increases the need of establishing a proactive prevention method for internal failures and relating risks in products. It also means that prevailing tacit knowledge in retired workers, in order to transform them to be easily used to support new system development, become more important. When considering safety and reliability design, at least two data sheet are necessary; Failure Modes and Effects Analyses (FMEA) and Risk Assessment (RA). These two data are practically made separately. However, it includes the concerns that a risk by failures during long-term use may not be noticed. To overcome this insufficiency, a support tool for integrating reliability evaluation and risk assessment data simultaneously is expected to be revealed. The authors have then developed a web-based design review system for reliability and safety system design. The system include various profitable functions; making FMEA and RA sheet, retrieving past data sheet for engineering change management and new product development and web-based discussion to increase the efficiency of discussion. The system is applied to one practical development works in order to demonstrate its effectiveness that is to be made clear by interviewing user's qualitative comment.

The Reliability of Balance, Gait, and Muscle Strength Test for the Elderly with Dementia: A Systematic Review

  • Lee, Han-Suk;Park, Sun-Wook
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.3
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    • pp.49-58
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    • 2017
  • PURPOSE: To summarize the evaluation tools of balance [Berg Balance Scale (BBS), timed up and Go (TUG), forward reaching test (FRT)], gait [6 m walking Test (6MWT)], and strength [Chair Stand Test (CST)] for patients with dementia. METHODS: The following databases were searched: Pub MED, Cochrane, Sciences Direct, and Web of Sciences. The inclusion criteria were as follows: 1) repeated measurement design, 2) subjects with dementia, 3) use of testing tools such as the BBS, TUG, FRT, 6MWT, and CST, 4) report the reliability. One reviewer performed the quality assessment of diagnostic accuracy study and two evaluators performed data extraction independently. RESULTS: Six articles and one letter were included. The interrater reliability of 6MWT, TUG, and CST, were acceptable (ICC>.90). However, FRT had unacceptable reliability. In test-retest reliability, only BBS has acceptable reliability (ICC>.90). Others had various reliabilities. The risk of interrater reliability bias was low in all studies. However, the risk of bias of intrarater reliability was low in five studies and moderate in two studies. CONCLUSION: The interrater reliability of the 6MWT, TUG, and CST were acceptable. However, in test-retest reliability, only BBS has acceptable reliability. Therefore, we suggest the use of BBS to test the balance of dementia patients. In addition, the study of tool reliability according to the subtype of dementia is needed in the future.

Evaluation of Human Reliability Analysis Results in Probabilistic Safety Assessment for Korea Standard Nuclear Power Plants (표준 원자력발전소 확률론적 안전성 평가의 인간 신뢰도 분석 평가)

  • 강대일;정원대;양준언
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.98-103
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    • 2003
  • Based on ASME probabilistic risk assessment (PRA) and NEI PRA peer review guidance, we evaluate a human reliability analysis (HRA) in probabilistic safety assessment (PSA) for Korea standard nuclear power plants, Ulchin Unit 3&4, to improve it performed at under design. The HRA for Ulchin Unit 3&4 is assessed as higher than Grade I based on ASME PRA standard and as higher than Grade 2 based on NEI PRA peer review guidance. The major items to be improved identified through the evaluation process are the documentation, the systematic human reliability analysis, the participitation of operators in the works and review of HRA. We suggest the guidance on the identification and qualitative screening analysis for pre-accident human errors and solve some items to be improved using the suggested guidance.