• 제목/요약/키워드: Data Reliability

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A Study on Reliability Analysis & Determination of Replacement Cycle of the Railway Vehicle Contactor (철도차량 접촉기의 신뢰성 분석 및 교환주기 결정에 대한 연구)

  • Park, Minheung;Rhee, Sehun
    • Journal of Applied Reliability
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    • 제17권4호
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    • pp.316-324
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    • 2017
  • Purpose: The purpose of this study is to determine the replacement cycle applied age replacement policy by reliability analysis based on railway vehicle contactor's failure history data. Method: We performed reliability analysis based on railway vehicle contactor's failure history data. We found a suitable distribution by goodness of fit test and predicted the reliability through estimation of scale & shape parameter. Considering cost information we determined the replacement cycle that minimize the opportunity cost. Result: Suitable distribution was the Weibull and scale parameter & shape parameter are estimated by reliability analysis. The replacement cycle was predicted and MTTF, $B_6$ percentile life were suggested additionally. Conclusion: We confirmed that failure rate type of railway vehicle contactor is degradation model having a time dependent characteristic and examined the replacement cycle in our country's operating environment. We expect that this study result contribute to railway operation agency for maintenance policy decision.

On Estimating the Hazard Rate for Samples from Weighted Distributions

  • Ahmad, Ibrahim A.
    • International Journal of Reliability and Applications
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    • 제1권2호
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    • pp.133-143
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    • 2000
  • Data from weighted distributions appear, among other situations, when some of the data are missing or are damaged, a case that is important in reliability and life testing. The kernel method for hazard rate estimation is discussed for these data where the basic large sample properties are given. As a by product, the basic properties of the kernel estimate of the distribution function for data from weighted distribution are presented.

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Process Evaluation for Reliability Insurance: An Industrial Case Study

  • Hong, Yeon-Woong
    • Journal of the Korean Data and Information Science Society
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    • 제16권2호
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    • pp.401-410
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    • 2005
  • In this paper, we calculate the premium rate of reliability insurance policy for brake pads for automobiles using real failure data obtained from use-condition. We try process capability analysis for the manufacturing process of brake-system. We describe the performance factors which have an effect on failure characteristics of brake pads. We also obtain the maximum likelihood estimates of shape and scale parameters of the fitted Weibull distribution for brake pads.

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Reliability Analysis of Air-conditioner with Service Data (에어컨 서비스데이터 신뢰도분석)

  • Yun, Won-Young;Sung, Mun-Hyun;Choung, Seock-Joo
    • IE interfaces
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    • 제12권1호
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    • pp.1-9
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    • 1999
  • This paper presents a method for reliability analysis of the air-conditioner with service data. We explain how to acquire and analyze the service data and some problems in data analysis. We propose two procedures to analyze reliability of air-conditioner using operating time concept and predict the operating times by temperature and failure frequency. Finally, the prediction method for future service is studied by numerical example.

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A Vtub-Shaped Hazard Rate Function with Applications to System Safety

  • Pham, Hoang
    • International Journal of Reliability and Applications
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    • 제3권1호
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    • pp.1-16
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    • 2002
  • In reliability engineering, the bathtub-shaped hazard rates play an important role in survival analysis and many other applications as well. For the bathtub-shaped, initially the hazard rate decreases from a relatively high value due to manufacturing defects or infant mortality to a relatively stable middle useful life value and then slowly increases with the onset of old age or wear out. In this paper, we present a new two-parameter lifetime distribution function, called the Loglog distribution, with Vtub-shaped hazard rate function. We illustrate the usefulness of the new Vtub-shaped hazard rate function by evaluating the reliability of several helicopter parts based on the data obtained in the maintenance malfunction information reporting system database collected from October 1995 to September 1999. We develop the S-Plus add-in software tool, called Reliability and Safety Assessment (RSA), to calculate reliability measures include mean time to failure, mean residual function, and confidence Intervals of the two helicopter critical parts. We use the mean squared error to compare relative goodness of fit test of the distribution models include normal, lognormal, and Weibull within the two data sets. This research indicates that the result of the new Vtub-shaped hazard rate function is worth the extra function-complexity for a better relative fit. More application in broader validation of this conclusion is needed using other data sets for reliability modeling in a general industrial setting.

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A Comparative Study of Software Reliability Model Considering Log Type Mean Value Function (로그형 평균값함수를 고려한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • 제10권4호
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    • pp.19-27
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    • 2014
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log type mean value function (Musa-Okumoto and log power model), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing log type mean value function was employed. This analysis of failure data compared with log type mean value function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

On Jacknife Reliability Estimation in the Weibull Case

  • Lee, In-Suk;Keum, Yoon-Hee
    • Journal of the Korean Data and Information Science Society
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    • 제13권2호
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    • pp.39-44
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    • 2002
  • We compare MISE of the MLE, UMVUE, invariantly optimal estimator and Jacknife estimator for the reliability function of the Weibull distribution when the sample size is small.

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On Reliability and UMVUE of Right-Tail Probability in a Half-Normal Variable

  • Woo, Jung-Soo
    • Journal of the Korean Data and Information Science Society
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    • 제18권1호
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    • pp.259-267
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    • 2007
  • We consider parametric estimation in a half-normal variable and a UMVUE of its right-tail probability. Also we consider estimation of reliability in two independent half-normal variables, and derive k-th moment of ratio of two same variables.

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Estimation of Reliability for a Two-Component Shared Parallel Systems Using System Life Data (체계수명자료를 이용한 이중부품부하분배체계의 신뢰도 추정)

  • 홍연웅;권용만
    • Journal of Korean Society for Quality Management
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    • 제25권4호
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    • pp.206-212
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    • 1997
  • This paper considers the problem of estimating parameters and reliability of shared parallel system with two identical components using type II censored system life data. Likelihood functions are derived and maximum likelihood estimates of parameters and reliability are discussed numerically.

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