• Title/Summary/Keyword: reliability theory

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A Study on the Inventive Problem Solving Method for Reliability Assurance of Product Development Process using the TRIZ (제품개발 공정신뢰성 확보를 위한 TRIZ 기반 창조적 문제해결 방법 연구)

  • Kim, Jong-Gurl;Lee, Suk-Jun;Kim, Hyung-Man
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.633-639
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    • 2008
  • Recently, product-reliability and process-reliability in product development processes has been regarded as an important issue in many manufacturers. TRIZ which is theory for inventive solving is required to obtain reliability of each process. To solve the technological problems, TRIZ provides problems can be occurred in product development processes as a contradiction matrix based on 40 creative invention principles with alternatives for physical and technological contradiction. This paper suggests the method for inventive solving to ensure the reliability assurance of product development processes based on TRIZ.

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Development of an Efficient Reliability Education Program for Domestic Industries (국내 실정에 적합한 신뢰성 교육 모형 개발에 관한 연구)

  • 권영섭;권영일;남경현;박동호;임재학;정해성
    • Proceedings of the Korean Reliability Society Conference
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    • 2004.07a
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    • pp.269-280
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    • 2004
  • In this paper, we propose a framework of reliability education program for industry people taking charge of reliability improvement or reliability evaluation. To this end, we investigate the situation of how reliability theories or reliability technologies are applied to industry and how industry people have reliability educations. And we also identify reliability theory or technology which industry people need to ensure. Based on the result of such studies, we design a reliability education program which is appropriate for industry people.

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A Performance Measure for Supply Chain System using Reliability Theory (신뢰성 이론을 이용한 공급 사슬 시스템의 평가 척도에 관한 연구)

  • Cho Min Kwan;Lee Young Hae
    • Proceedings of the Society of Korea Industrial and System Engineering Conference
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    • 2002.05a
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    • pp.195-202
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    • 2002
  • The primary objective of Supply Chain Management (SCM) is to optimize the cash, material and information flow for satisfying customer demands through coordinating the relationship between Supply Chain components such as suppliers, manufacturers, and inventories, etc. By Supply Chain Planning (SCP), operation tasks or goals, should be done in specific due date, are ordered to each SC component for achieving such objective. However, the achievement for operation tasks or goals is affected by uncertainties in SC. In general, reliability theory Is explained as the probability that a product or system will perform its specified function under prescribed conditions without failure for a specified period of time. Therefore, the reliability of SC can be defined as the probability that SC will satisfy customer demands until the specific due date. In this paper, a basic framework to evaluate reliability is respectively proposed as supply chain components, and then a overall framework to estimate the reliability for SC is also proposed.

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Fatigue Life Prediction using Fuzzy Reliability theory (퍼지신뢰성이론에 의한 피로수명 예측)

  • 심확섭;이치우;장건의
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.672-675
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    • 1995
  • Because of a sudden growth of the research of fatigue failure, recent machines or structures have been designed by damage tolerance design in many fields. Consequently, it is the most primary factor to clarity the specific character of fatique failure in the design of machines or structures considering reliability. A statistical analysis is required to analyze the outcome of an experiment or a life estimate by reason of that fatigue failure contains lots of random elements. Reliability analysis which has tukenn the place of the existing analyses in the consideration of the uncertainty of a material, is a very efficient way. Even reliability analysis, however, is not a perfect way to analyses the uncertainties of all the materials. This thesis would refer to a newly conceived data analysis that the coefficient of a system could cause the ambiguity of the relationship of an input and output.

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A Study on Optimum Reliability of P.S.C Box Girder Bridge (최적신뢰성에 의한 P.S.C Box Girder교의 연구)

  • Jung, Chul-Won;Yu, Han-Shin;Na, Ki-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.4
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    • pp.139-144
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    • 1999
  • Based on the recent developments of the reliability-based structural analysis and design as well as the extending knowledge on the probabiliistic characteristics of load and resistances, the probability based design criteria have been successfully developed for many standards. Since the probabilistic characteristics depend highly on the local load and resistances, it is recognized to develop the design criterion compatible with domestic requirements. The existing optimum design methods, which are generally based on the structural theory and certain engineering experience, do not realistically consider the uncertainties of load and resistances and the basic reliability concepts. This study is directed to propose a optimum design based Expected Total Cost Minimization on P.S.C Box Girder Bridge system which could possibly replace optimum design based traditional provisions of the current code, based on the Neldel-Mead Method reliability theory.

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A Dependability Modeling of Software Under Memory Faults for Digital System in Nuclear Power Plants

  • Park, Jong-Gyun;Seong, Poong-Hyun
    • Nuclear Engineering and Technology
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    • v.29 no.6
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    • pp.433-443
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    • 1997
  • In this work, an analytic approach to the dependability of software in the operational phase is suggested with special attention to the hardware fault effects on the software behavior : The hardware faults considered are memory faults and the dependability measure in question is the reliability. The model is based on the simple reliability theory and the graph theory which represents the software with graph composed of nodes and arcs. Through proper transformation, the graph can be reduced to a simple two-node graph and the software reliability is derived from this graph. Using this model, we predict the reliability of an application software in the digital system (ILS) in the nuclear power plant and show the sensitivity of the software reliability to the major physical parameters which affect the software failure in the normal operation phase. We also found that the effects of the hardware faults on the software failure should be considered for predicting the software dependability accurately in operation phase, especially for the software which is executed frequently. This modeling method is particularly attractive for the medium size programs such as the microprocessor-based nuclear safety logic program.

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An Analytical Study of the Flexural Deformation for High Strength Concrete Structures using Reliability Theory (신뢰성 이론을 이용한 500kgf/$\textrm{cm}^2$의 고강도콘크리트 구조물에 대한 휨변형의 해석적 연구)

  • 송재호;최광진;김민웅;홍원기
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.231-236
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    • 1995
  • The object of this thesis is an analytical study on flexural deformation of high strength concrete structures using reliability theory. Using the established experimental data that have been presented in various documents the stress-strain relationship curves of high strength(500kgf/$\textrm{cm}^2$)models are proposed. Based on both methods of logarithm regression analysis and multiple regression analysis adopted in order to establish the relationships between design parameters, response random variables and flexural deformation analyzed using Monte Carlo simulation and Simpson composite formula. Additional random variables are introduced to incorporate both the confidence in the analytical accuracy of engineering mechanics associated with structural response quantities and the uncertainty in the construction quality control. The result is expected to accomodate other important design parameter of high strength concrete design in treating reliability theory that practicing engineers, structural engineering often face.

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신뢰성이론에 근거한 교량의 활하중모델

  • Oh, Byeong-Hwan;Lee, Hyeong-Jun;Shin, Ho-Sang;Yang, In-Hwan;Yoo, Yeong
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.339-343
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    • 1995
  • In assessing the performance of structures such as bridges. the load intensity, load effect analysis and strength parameters are not known with certainty. The aim of structural reliability theory is to account for the uncertainties in evaluating the strength of structural systems or in the calibration of safety factors in structural design codes. The intend of structural reliability theory is to characterize these uncertainties and allow for consistent and rational safety decisions. In this study the rational model considering the live load applied to bridge will be introduced. using the structural reliability theory.

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Analysis of Error Source in Subjective Evaluation on Patient Dentist Interaction : Application of Generalizability Theory (환자-치과의사 관계(PDI Patient Dentist Interaction) 평가의 오차원 분석: 일반화가능도 이론 적용)

  • Kim, Jooah;Cho, Lee-Ra
    • The Journal of the Korean dental association
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    • v.57 no.8
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    • pp.448-455
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    • 2019
  • This study aims to apply the Generalizability Theory (G-theory) for estimation of reliability of evaluation scores between raters on Patient Dentist Interaction. Selecting a number of raters as multiple error sources, this study was analyzed the error sources caused by relative magnitude of error variances of interaction between the factors and proceeded with D-study based on the results of G-study for optimal determination of measurement condition. The estimated outcomes of variance component for accuracy among the Patient Dentist Interaction evaluation with G-theory showed that impact of error was the biggest influence factor in students. The second influence was the item effect, and the rater effect was relatively small. The Generalizability coefficients for case1 and case2 which were estimated through the D- study were calculated relatively low.

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Reliability Updates of Driven Piles Based on Bayesian Theory Using Proof Pile Load Test Results (베이지안 이론을 이용한 타입강관말뚝의 신뢰성 평가)

  • Park, Jae-Hyun;Kim, Dong-Wook;Kwak, Ki-Seok;Chung, Moon-Kyung;Kim, Jun-Young;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.161-170
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    • 2010
  • For the development of load and resistance factor design, reliability analysis is required to calibrate resistance factors in the framework of reliability theory. The distribution of measured-to-predicted pile resistance ratio was obrained based on only the results of load tests conducted to failure for the assessment of uncertainty regarding pile resistance and used in the conventional reliability analysis. In other words, successful pile load test (piles resisted twice their design loads without failure) results were discarded, and therefore, were not reflected in the reliability analysis. In this paper, a new systematic method based on Bayesian theory is used to update reliability indices of driven steel pipe piles by adding more proof pile load test results, even not conducted to failure, to the prior distribution of pile resistance ratio. Fifty seven static pile load tests performed to failure in Korea were compiled for the construction of prior distribution of pile resistance ratio. The empirical method proposed by Meyerhof is used to calculate the predicted pile resistance. Reliability analyses were performed using the updated distribution of pile resistance ratio. The challenge of this study is that the distribution updates of pile resistance ratio are possible using the load test results even not conducted to failure, and that Bayesian updates are most effective when limited data are available for reliability analysis.