• Title/Summary/Keyword: The Reliability

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Reliability Equivalence Factors of Non-identical Components Series System with Mixture Failure Rates

  • Mustafa, A.;El-Desouky, B.S.;El-Dawoody, M.
    • International Journal of Reliability and Applications
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    • v.10 no.1
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    • pp.17-32
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    • 2009
  • The aim of this work is to generalize reliability equivalence technique to apply it to a system consists of n independent and non-identical components connected in series system, that have mixing constant failure rates. We shall improve the system by using some reliability techniques: (i) reducing some failure rates; (ii) add hot reduncy components; (iii) add cold reduncy components; (iv) add cold reduncy components with imperfect switches. We start by establishing two different types of reliability equivalence factors, the survival equivalence (SRE), and mean reliability equivalence (MRE) factors. Also, we introduced some numerical results.

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Design of Bayesian Zero-Failure Reliability Demonstration Test and Its Application (베이지안 신뢰성입증시험 설계와 활용)

  • Kwon, Young Il
    • Journal of Applied Reliability
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    • v.13 no.1
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    • pp.1-10
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    • 2013
  • A Bayesian zero-failure reliability demonstration test method for products with exponential lifetime distribution is presented. Beta prior distribution for reliability of a product is used to design the Bayesian test plan and selecting a prior distribution using a prior test information is discussed. A test procedure with zero-failure acceptance criterion is developed that guarantees specified reliability of a product with given confidence level. An example is provided to illustrate the use of the developed Bayesian reliability demonstration test method.

Inter-Rater and Intra-Rater Reliability of the Modified Ashworth Scale and the Modified Tardieu Scale: A Comparison Study (수정된 Ashworth 척도와 수정된 Tardieu 척도의 검사자간, 검사자내 신뢰도 비교 연구)

  • Choi, Yul-Jung;Lee, Jung-Ah;Shin, Hwa-Kyung
    • The Journal of Korean Physical Therapy
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    • v.22 no.4
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    • pp.29-33
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    • 2010
  • Purpose: The purpose of this study was to assess and compare the reliability of the Modified Tardieu Scale (MTS) with the Modified Ashworth Scale (MAS) in patients with hemiplegia. Methods: Two experienced physical therapists examined twenty six patients (17 male and 9 female) with an age range of 19-83 years (mean=51.9 SD=15.2). They assessed the elbow flexor/extensor muscle spasticity in the affected side. Interand intra-rater reliability of the MAS and the MTS were calculated using kappa statistics. Intraclass correlation coefficient (ICC) was calculated to determine the inter- and intra-rater reliability of the angle of muscle reactions (R2-R1). Results: The intra-rater reliability of the MAS (K=0.39-0.55) and MTS (K=0.33-0.55) was fair to moderate. The inter-rater reliability was significantly higheras measured with MTS (K=0.54-0.66) in comparison with MAS (K=0.52). Intra-rater reliability of R2-R1 was moderate to almost perfect (ICC=0.52-0.86), and inter-rater reliability was substantial (ICC=0.74-0.76). Conclusion: The MTS provides higher inter-rater reliability compared with the MAS in hemiplegia patient analysis, but intra-rater reliability of both scales was not significantly different. Thus further research is needed to examine not only reliability, but also validity of these measurement systems.

기계산업 경쟁력향상을 위한 신뢰성평가 추진 방향

  • 김형의
    • Proceedings of the Korean Reliability Society Conference
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    • 2000.11a
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    • pp.57-74
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    • 2000
  • This paper examined current problem of reliability assessment project on mechanical components being domestically pursued, and from the point of new view suggested directions to a comprehensive reliability assurance added quality assurance, suitable to realities in our industries.

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Reliability Program at Cernavoda NPP

  • Tudor, E.C.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05a
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    • pp.876-880
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    • 1998
  • This Paper Provides an overview of reliability Program implemented at Cernavoda NPP. It was written to serve the experience exchange between Cernavoda and Wolsung NPPs in the plant safety and systems reliability area.

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A Study on Reliability Based Design Criteria for Erection Members (가설부재의 신속성 설계기준에 관한 연구)

  • 민경주
    • Journal of the Korean Society of Safety
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    • v.6 no.3
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    • pp.56-63
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    • 1991
  • This study investigates reliability based design criteria for the erection members, and proposes practical algorithm which is based on Ellingwood's algorithm for the reliability analysis and the derivation of reliability based criteria. The magnitude of the uncertainties associated with load effects are chosen primarily by considering our level of practice. And thus the uncertainties so obtained are applied for the reliability analysis and the derivation of reliability based design criteria. A target reliability($\beta$$_{o}$=2.0) is selected as an appropriate value by analyzing the reliability levels of our current USD and WSD design standards. Them a set of load and resistance factors corresponding to the target reliability is proposed as a reliability based design provision, and furthermore a set of allowable stresses for steel having same level of reliability with the corresponding LRFD criteria is also prepared for the current WSD design provision. It may be concluded that the proposed LRFD reliability based design provisions and the corresponding allowable stresses give more rational design than the current code for erection membars.s.s.

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Influence Analysis of Sampling Points on Accuracy of Storage Reliability Estimation for One-shot Systems (원샷 시스템의 저장 신뢰성 추정 정확성에 대한 샘플링 시점의 영향 분석)

  • Chung, Yong H.;Oh, Bong S.;Lee, Hong C.;Park, Hee N.;Jang, Joong S.;Park, Sang C.
    • Journal of Applied Reliability
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    • v.16 no.1
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    • pp.32-40
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    • 2016
  • Purpose: The purpose of this study is to analyze the effect of sampling points on accuracy of storage reliability estimation for one-shot systems by assuming a weibull distribution as a storage reliability distribution. Also propose method for determining of sampling points for increase the accuracy of reliability estimation. Methods: Weibull distribution was divided into three sections for confirming the possible to estimate the parameters of the weibull distribution only some section's sample. Generate quantal response data for failure data. And performed parameter estimation with quantal response data. Results: If reduce sample point interval of 1 section, increase the accuracy of reliability estimation although sampling only section 1. Even reduce total number of sampling point, reducing sampling time interval of the 1 zone improve the accuracy of reliability estimation. Conclusion: Method to increase the accuracy of reliability estimation is increasing number of sampling and the sampling points. But apply this method to One-shot system is difficult because test cost of one-shot system is expensive. So propose method of accuracy of storage reliability estimation of one-shot system by adjustment of the sampling point. And by dividing the section it could reduce the total sampling point.

Factors driving Fashion Chatbot Reliability -Focusing on the Mediating Effect of Perceived Intelligence and Positive Cognition- (패션상품 챗봇에 대한 신뢰 형성 요인 - 지각된 지능과 긍정적 인지의 매개효과를 중심으로 -)

  • Lee, Ha Kyung;Yoon, Namhee
    • Fashion & Textile Research Journal
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    • v.24 no.2
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    • pp.229-240
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    • 2022
  • This study explores the effect of anthropomorphism on fashion chatbot reliability, mediated by perceived intelligence and cognitive evaluation. The moderating effects of individuals' need for human interaction between chatbot anthropomorphism and perceived intelligence, cognitive evaluation, and chatbot reliability are also explored. Participants, who were recruited through the online research firm, responded to questions after watching a video clip showing a conversation with a fashion chatbot on a mobile screen. The data were collected through Mturk, a crowdsourcing platform with an online research panel. All responses (N = 212) were analyzed using SPSS 26.0 for the descriptive statistics, frequency analysis, reliability analysis, exploratory factor analysis, and PROCESS procedure. The results demonstrate that chatbot anthropomorphism increases chatbot reliability, and this is mediated by chatbot intelligence. Although chatbot anthropomorphism increases cognitive evaluation, the effect of cognitive evaluation on chatbot reliability is not significant; thereby, the effect of chatbot anthropomorphism on chatbot reliability is not mediated by the cognitive evaluation. The direct effect of anthropomorphism on chatbot reliability is also moderated by individuals' need for human interaction. For participants with a high need for human interaction, chatbot anthropomorphism increases chatbot reliability; however, anthropomorphism does not significantly affect chatbot reliability for participants with a low need for human interaction. The study's findings contribute to expanding the literature on consumers' new technology acceptance by testing the antecedents affecting service reliability.