The Generalized Renewal Process (GRP) is a probabilistic model for repairable systems that can represent the usual states of a system after a repair: as new, as old, or in a condition between new and old. It is often coupled with the Weibull distribution, widely used in the reliability context. In this paper, we develop novel GRP models based on probability distributions that stem from the Tsal...

Two important wood properties are the modulus of elasticity (MOE) and the modulus of rupture (MOR). In the past, the statistical distribution of the MOE has often been modeled as Gaussian, and that of the MOR as lognormal or as a twoor three-parameter Weibull distribution. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purp...

The typical experimental procedure for testing stress corrosion cracking initiation involves an interval-censored reliability test. Based on these test results, the parameters of a Weibull distribution, which is a widely accepted crack initiation model, can be estimated using maximum likelihood estimation or median rank regression. However, it is difficult to determine the appropriate number of...

Recently, several attempts have been made to define new models that extend well-known distributions and at the same time provide great flexibility in modelling real data. We propose a new four-parameter model named the Weibull-power function (WPF) distribution which exhibits bathtub-shaped hazard rate. Some of its statistical properties are obtained including ordinary and incomplete moments, qu...

Background: Thalassemia major (TM) is a severe disease and the most common anemia worldwide. The survival time of the disease and its risk factors are of importance for physicians. The present study was conducted to apply the semi-parametric Cox PH model and use parametric proportional hazards (PH) and accelerated failure time (AFT) models to identify the risk factors related to survival of TM ...

The authors will demonstrate how a major Chemical Process company has successfully utilized this new technique to answer questions such as: 1. Do I have a reliability problem or a production problem? 2. What is the demonstrated capacity of my plant? 3. What are efficiency/utilization losses costing me? 4. What is the reliability of my process plant? The Weibull technique described has helped th...

It is known that the single-modal Weibull model describes well the size effect of brittle fiber tensile strength. However, some ceramic fibers have been reported that single-modal Weibull model provided biased estimation on the gauge length dependence. A hypothesis on the bias is that the density of critical defects is very small, thus, fracture probability of small gauge length samples distrib...

the data set employed in this study was comprised of a number of 6,800 records of lamb’s longevity and their survival rate, collected from 1989 through 2009, from the lori-bakhtiari experimental flock at the shooli station in shahrekord, iran. the data were analyzed using linear models and proportional hazard models with weibull function. these models included fixed factors and direct additive ...

the weibull distribution has been widely used in survival and engineering reliability analysis. in life testing experiments is fairly common practice to terminate the experiment before all the items have failed, that means the data are censored. thus, the main objective of this paper is to estimate the reliability function of the weibull distribution with uncensored and censored data by using b...

Weibull distribution was used to fit tree diameter data collected from 86 sample plots located in Chinese pine stand in Beijing. To estimate the Weibull distribution parameters, three methods [namely maximum likelihood estimation method (MLE), method of moment (MOM) and least-squares regression method (LSM)] were compared and evaluated on the basis of the mean square error (MSE) and sample size...