• Observed and unobserved heterogeneity in failure data analysis 

      Zaki, Rezgar; Barabadi, Abbas; Barabady, Javad; Qarahasanlou, Ali Nouri (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-08)
      In reality, failure data are often collected under diffract operational conditions (covariates), leading to heterogeneity among the data. Heterogeneity can be classified as observed and unobserved heterogeneity. Un-observed heterogeneity is the effect of unknown, unrecorded, or missing covariates. In most reliability studies, the effect of unobserved covariates is neglected. This may lead to inaccurate ...
    • Prediction of remaining useful life (RUL) of Komatsu excavator under reliability analysis in the Weibull-frailty model 

      Ghomghaleh, Awat; Khaloukakaie, Reza; Ataei, Mohammad; Barabadi, Abbas; Qarahasanlou, Ali Nouri; Rahmani, Omeid; Beiranvand Pour, Amin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-15)
      It is an essential task to estimate the remaining useful life (RUL) of machinery in the mining sector aimed at ensuring the production and the customer’s satisfaction. In this study, a conceptual framework was used to determine the RUL under the reliability analysis in a frailty model. The proposed framework was implemented on a Komatsu PC-1250 excavator from the Sungun copper mine. Also, the ...