• Title/Summary/Keyword: reliability equivalence

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Reliability Equivalence of Two Non-identical Components

  • Mustafa, A.
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.79-93
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    • 2008
  • The aim of this work is to generalize reliability equivalence techniques to apply them to a system consists of two independent and non-identical components connected in series(parallel) system, that have constant failure rates. We shall improve the system by using one component only. We start by establishing two different types of reliability equivalence factors, the survival reliability equivalence (SRE) and mean reliability equivalence (MRE) factors. Our second studies, introducing some applications for our studies in airports and our life. Also, we introduced some numerical results.

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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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Reliability Equivalence Factors of n-components Series System with Non-constant Failure Rates

  • Mustafa, A.
    • International Journal of Reliability and Applications
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    • v.10 no.1
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    • pp.43-57
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    • 2009
  • In this article, we study the reliability equivalence factor of a series system. The failure rates of the system components are functions of time t. we study two cases of non-constat failure rates (i) weibull distribution (ii) linear increasing failure rate distribution. There are two methods are used to improve the given system. Two types of reliability equivalence factors are discussed. Numerical examples are presented to interpret how one can utilize the obtained results.

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Reliability Equivalence Factors of a Series - Parallel System in Weibull Distribution

  • El-Damcese, M.A.;Khalifa, M.M.
    • International Journal of Reliability and Applications
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    • v.9 no.2
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    • pp.153-165
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    • 2008
  • This paper discusses the reliability equivalences of a series-parallel system. The system components are assumed to be independent and identical. The failure rates of the system components are functions of time and follow Weibull distribution. Three different methods are used to improve the given system reliability. The reliability equivalence factor is obtained using the reliability function. The fractiles of the original and improved systems are also obtained. Numerical example is presented to interpret how to utilize the obtained results.

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Reliability Equivalence Factors of a Bridge Network System

  • Sarhan, Ammar M.
    • International Journal of Reliability and Applications
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    • v.5 no.2
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    • pp.81-103
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    • 2004
  • Improvements of a bridge network system are studied in this paper. Then equivalence between different improved designs of the bridge network system is discussed. Three different methods are used to get different better designs of the network in the sense of having higher reliability and mean time to failure. Then two different types of reliability equivalence factors of the system are derived. It is assumed here that the failure rates of the system's components are identical and constant. The reliability functions and mean time to failure of the original and improved designs of the network are derived. Comparison between the mean time to failures of the original system and improved designs of the system are presented. Numerical studies and conclusion are presented in order to explain how one can apply the the theoretical results obtained.

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Error Analysis of Equivalence Ratio using Bayesian Statistics (베이지안 확률기법을 이용한 당량비 오차분석에 관한 연구)

  • Ahn, Joongki;Park, Ik Soo;Lee, Ho-il
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.2
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    • pp.131-137
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    • 2018
  • This paper analyzes the probability of failure for the equivalence ratio error. The control error of the equivalence ratio is affected by the aleatory and epistemic uncertainties. In general, reliability analysis techniques are easily incorporated to handle the aleatory uncertainty. However, the epistemic uncertainty requires a new approach, as it does not provide an uncertainty distribution. The Bayesian inference incorporates the reliability analysis results to handle both uncertainties. The result gives a distribution of failure probability, whose equivalence ratio does not meet the requirement. This technique can be useful in the analysis of most engineering systems, where the aleatory and epistemic uncertainties exist simultaneously.

Reliability Equivalence of a Non-identical Components Parallel System

  • Montaser, M.;Sarhan, Ammar M.
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.95-112
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    • 2008
  • This paper gives the reliability equivalence factors of a parallel system with n independent and non-identical components. It is assumed here that, the failure rates of the system's components are constants. We used three different methods to improve the system given. Two reliability characteristics (the mean time to failure and the reliability function) are used to perform the system improvement. For this purpose, the reliability functions and the mean times to failures of the original and improved systems are obtained. The results given in this paper generalize the results given in the literatures by setting n = 1, 2. An illustrative numerical example is presented to compare the different reliability factors obtained.

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Evaluating and improving system reliability of bridge structure using gamma distribution

  • Mustaf, Abdelfattah;El-Desouky, Beih S.;Taha, Ahmed
    • International Journal of Reliability and Applications
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    • v.17 no.2
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    • pp.121-135
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    • 2016
  • In this paper, we study a system of five components. One of them is a bridge network component. Each of these components is identical and has a failure rate as a function of time. The system components have non-constant failure rates. The given system is improved by using the reduction, hot duplication, and cold duplication methods. We derive the equivalence factors of the bridge structure system to be as another system improved according to these different methods. The ${\beta}-fractiles$ are obtained to compare the original system with these improved systems. Finally, we present numerical results to show the difference between these methods.

Availability equivalence factors of a general repairable series-parallel system

  • Sarhan, Ammar M.;Mustafa, Abdelfatth
    • International Journal of Reliability and Applications
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    • v.14 no.1
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    • pp.11-26
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    • 2013
  • The availability equivalence factors of a general repairable series-parallel system is discussed in this paper based on the availability function of the system. The system components are assumed to be repairable and independent but not identical. The life and repair times of the system components are exponentially distributed with different parameters. Two types of availability equivalent factors of the system are derived. The results derived in this paper generalizes those given in the literature. A case study is introduced to illustrate how the idea of this work can be applied.

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Reliability Equivalences of a Series System Consists of n Independent and Non-identical Components

  • Sarhan, A.M.;Mustafa, A.
    • International Journal of Reliability and Applications
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    • v.7 no.2
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    • pp.111-125
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    • 2006
  • This paper introduces different vectors of the reliability equivalence factors of a series system consists of n independent and nonidentical components. The failure rates of the system components are assumed to be constant. The reliability function and mean time to failure are used as performances to derive the reliability equivalences of the system. The results presented here generalize those available in the literatures. Numerical study is given to explain how one can utilize the theoretical results obtained.

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